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Import OpenSSH 9.5 (Last was OpenSSH 9.3) OpenSSH 9.5/9.5p1 (2023-10-04) OpenSSH 9.5 was released on 2023-10-04. It is available from the mirrors listed at https://www.openssh.com/. OpenSSH is a 100% complete SSH protocol 2.0 implementation and includes sftp client and server support. Once again, we would like to thank the OpenSSH community for their continued support of the project, especially those who contributed code or patches, reported bugs, tested snapshots or donated to the project. More information on donations may be found at: https://www.openssh.com/donations.html Changes since OpenSSH 9.4 ========================= This release fixes a number of bugs and adds some small features. Potentially incompatible changes -------------------------------- * ssh-keygen(1): generate Ed25519 keys by default. Ed25519 public keys are very convenient due to their small size. Ed25519 keys are specified in RFC 8709 and OpenSSH has supported them since version 6.5 (January 2014). * sshd(8): the Subsystem directive now accurately preserves quoting of subsystem commands and arguments. This may change behaviour for exotic configurations, but the most common subsystem configuration (sftp-server) is unlikely to be affected. New features ------------ * ssh(1): add keystroke timing obfuscation to the client. This attempts to hide inter-keystroke timings by sending interactive traffic at fixed intervals (default: every 20ms) when there is only a small amount of data being sent. It also sends fake "chaff" keystrokes for a random interval after the last real keystroke. These are controlled by a new ssh_config ObscureKeystrokeTiming keyword. * ssh(1), sshd(8): Introduce a transport-level ping facility. This adds a pair of SSH transport protocol messages SSH2_MSG_PING/PONG to implement a ping capability. These messages use numbers in the "local extensions" number space and are advertised using a "ping@openssh.com" ext-info message with a string version number of "0". * sshd(8): allow override of Subsystem directives in sshd Match blocks. Bugfixes -------- * scp(1): fix scp in SFTP mode recursive upload and download of directories that contain symlinks to other directories. In scp mode, the links would be followed, but in SFTP mode they were not. bz3611 * ssh-keygen(1): handle cr+lf (instead of just cr) line endings in sshsig signature files. * ssh(1): interactive mode for ControlPersist sessions if they originally requested a tty. * sshd(8): make PerSourceMaxStartups first-match-wins * sshd(8): limit artificial login delay to a reasonable maximum (5s) and don't delay at all for the "none" authentication mechanism.cw bz3602 * sshd(8): Log errors in kex_exchange_identification() with level verbose instead of error to reduce preauth log spam. All of those get logged with a more generic error message by sshpkt_fatal(). * sshd(8): correct math for ClientAliveInterval that caused the probes to be sent less frequently than configured. * ssh(1): fix regression in OpenSSH 9.4 (mux.c r1.99) that caused multiplexed sessions to ignore SIGINT under some circumstances. Portability ----------- * Avoid clang zero-call-used-regs=all bug on Apple compilers, which for some reason have version numbers that do not match the upstream clang version numbers. bz#3584 * Fix configure test for zlib 1.3 and later/development versions. bz3604 Checksums: ========== - SHA1 (openssh-9.5.tar.gz) = 8a0bd3a91fac338d97d91817af58df731f6509a3 - SHA256 (openssh-9.5.tar.gz) = sVMxeM3d6g65qBMktJIofxmK4Ipg9dblKif0VnhPeO0= - SHA1 (openssh-9.5p1.tar.gz) = 35c16dcc6e7d0a9465faa241476ef24f76b196cc - SHA256 (openssh-9.5p1.tar.gz) = 8Cbnt5un+1QPdRgq+W3IqPHbOV+SK7yfbKYDZyaGCGs= Please note that the SHA256 signatures are base64 encoded and not hexadecimal (which is the default for most checksum tools). The PGP key used to sign the releases is available from the mirror sites: https://cdn.openbsd.org/pub/OpenBSD/OpenSSH/RELEASE_KEY.asc Reporting Bugs: =============== - Please read https://www.openssh.com/report.html Security bugs should be reported directly to openssh@openssh.com OpenSSH 9.4/9.4p1 (2023-08-10) OpenSSH 9.4 was released on 2023-08-10. It is available from the mirrors listed at https://www.openssh.com/. OpenSSH is a 100% complete SSH protocol 2.0 implementation and includes sftp client and server support. Once again, we would like to thank the OpenSSH community for their continued support of the project, especially those who contributed code or patches, reported bugs, tested snapshots or donated to the project. More information on donations may be found at: https://www.openssh.com/donations.html Changes since OpenSSH 9.3p2 =========================== This release fixes a number of bugs and adds some small features. Potentially incompatible changes -------------------------------- * This release removes support for older versions of libcrypto. OpenSSH now requires LibreSSL >= 3.1.0 or OpenSSL >= 1.1.1. Note that these versions are already deprecated by their upstream vendors. * ssh-agent(1): PKCS#11 modules must now be specified by their full paths. Previously dlopen(3) could search for them in system library directories. New features ------------ * ssh(1): allow forwarding Unix Domain sockets via ssh -W. * ssh(1): add support for configuration tags to ssh(1). This adds a ssh_config(5) "Tag" directive and corresponding "Match tag" predicate that may be used to select blocks of configuration similar to the pf.conf(5) keywords of the same name. * ssh(1): add a "match localnetwork" predicate. This allows matching on the addresses of available network interfaces and may be used to vary the effective client configuration based on network location. * ssh(1), sshd(8), ssh-keygen(1): infrastructure support for KRL extensions. This defines wire formats for optional KRL extensions and implements parsing of the new submessages. No actual extensions are supported at this point. * sshd(8): AuthorizedPrincipalsCommand and AuthorizedKeysCommand now accept two additional %-expansion sequences: %D which expands to the routing domain of the connected session and %C which expands to the addresses and port numbers for the source and destination of the connection. * ssh-keygen(1): increase the default work factor (rounds) for the bcrypt KDF used to derive symmetric encryption keys for passphrase protected key files by 50%. Bugfixes -------- * ssh-agent(1): improve isolation between loaded PKCS#11 modules by running separate ssh-pkcs11-helpers for each loaded provider. * ssh(1): make -f (fork after authentication) work correctly with multiplexed connections, including ControlPersist. bz3589 bz3589 * ssh(1): make ConnectTimeout apply to multiplexing sockets and not just to network connections. * ssh-agent(1), ssh(1): improve defences against invalid PKCS#11 modules being loaded by checking that the requested module contains the required symbol before loading it. * sshd(8): fix AuthorizedPrincipalsCommand when AuthorizedKeysCommand appears before it in sshd_config. Since OpenSSH 8.7 the AuthorizedPrincipalsCommand directive was incorrectly ignored in this situation. bz3574 * sshd(8), ssh(1), ssh-keygen(1): remove vestigal support for KRL signatures When the KRL format was originally defined, it included support for signing of KRL objects. However, the code to sign KRLs and verify KRL signatues was never completed in OpenSSH. This release removes the partially-implemented code to verify KRLs. All OpenSSH tools now ignore KRL_SECTION_SIGNATURE sections in KRL files. * All: fix a number of memory leaks and unreachable/harmless integer overflows. * ssh-agent(1), ssh(1): don't truncate strings logged from PKCS#11 modules; GHPR406 * sshd(8), ssh(1): better validate CASignatureAlgorithms in ssh_config and sshd_config. Previously this directive would accept certificate algorithm names, but these were unusable in practice as OpenSSH does not support CA chains. bz3577 * ssh(1): make `ssh -Q CASignatureAlgorithms` only list signature algorithms that are valid for CA signing. Previous behaviour was to list all signing algorithms, including certificate algorithms. * ssh-keyscan(1): gracefully handle systems where rlimits or the maximum number of open files is larger than INT_MAX; bz3581 * ssh-keygen(1): fix "no comment" not showing on when running `ssh-keygen -l` on multiple keys where one has a comment and other following keys do not. bz3580 * scp(1), sftp(1): adjust ftruncate() logic to handle servers that reorder requests. Previously, if the server reordered requests then the resultant file would be erroneously truncated. * ssh(1): don't incorrectly disable hostname canonicalization when CanonicalizeHostname=yes and ProxyJump was expicitly set to "none". bz3567 * scp(1): when copying local->remote, check that the source file exists before opening an SFTP connection to the server. Based on GHPR#370 Portability ----------- * All: a number of build fixes for various platforms and configuration combinations. * sshd(8): provide a replacement for the SELinux matchpathcon() function, which is deprecated. * All: relax libcrypto version checks for OpenSSL >=3. Beyond OpenSSL 3.0, the ABI compatibility guarantees are wider (only the library major must match instead of major and minor in earlier versions). bz#3548. * Tests: fix build problems for the sk-dummy.so FIDO provider module used in some tests. Checksums: ========== - SHA1 (openssh-9.4.tar.gz) = d88126d8d7b8e5bf4656587ac4a16055560641cc - SHA256 (openssh-9.4.tar.gz) = 7eqFjx2hAunw+1Jy7f1JQXq//3AMr9B3dKtASDtq8go= - SHA1 (openssh-9.4p1.tar.gz) = 5dea1f3c88f9cfe53a711a3c893ee8b7d3ffecff - SHA256 (openssh-9.4p1.tar.gz) = Ngj9kIjbIWPOs+YAyFq3nQ3j0iHlkZLqGSPiMmOGaoU= Please note that the SHA256 signatures are base64 encoded and not hexadecimal (which is the default for most checksum tools). The PGP key used to sign the releases is available from the mirror sites: https://cdn.openbsd.org/pub/OpenBSD/OpenSSH/RELEASE_KEY.asc Reporting Bugs: =============== - Please read https://www.openssh.com/report.html Security bugs should be reported directly to openssh@openssh.com
2023-10-25 23:14:30 +03:00
/* $OpenBSD: servconf.h,v 1.160 2023/09/06 23:35:35 djm Exp $ */
import 5.2 from ftp.openbsd.org
2009-06-08 02:19:00 +04:00
/*
* Author: Tatu Ylonen <ylo@cs.hut.fi>
* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
* All rights reserved
* Definitions for server configuration data and for the functions reading it.
*
* As far as I am concerned, the code I have written for this software
* can be used freely for any purpose. Any derived versions of this
* software must be clearly marked as such, and if the derived work is
* incompatible with the protocol description in the RFC file, it must be
* called by a name other than "ssh" or "Secure Shell".
*/
#ifndef SERVCONF_H
#define SERVCONF_H
OpenSSH 8.2/8.2p1 (2020-02-14) OpenSSH 8.2 was released on 2020-02-14. It is available from the mirrors listed at https://www.openssh.com/. OpenSSH is a 100% complete SSH protocol 2.0 implementation and includes sftp client and server support. Once again, we would like to thank the OpenSSH community for their continued support of the project, especially those who contributed code or patches, reported bugs, tested snapshots or donated to the project. More information on donations may be found at: https://www.openssh.com/donations.html Future deprecation notice ========================= It is now possible[1] to perform chosen-prefix attacks against the SHA-1 hash algorithm for less than USD$50K. For this reason, we will be disabling the "ssh-rsa" public key signature algorithm that depends on SHA-1 by default in a near-future release. This algorithm is unfortunately still used widely despite the existence of better alternatives, being the only remaining public key signature algorithm specified by the original SSH RFCs. The better alternatives include: * The RFC8332 RSA SHA-2 signature algorithms rsa-sha2-256/512. These algorithms have the advantage of using the same key type as "ssh-rsa" but use the safe SHA-2 hash algorithms. These have been supported since OpenSSH 7.2 and are already used by default if the client and server support them. * The ssh-ed25519 signature algorithm. It has been supported in OpenSSH since release 6.5. * The RFC5656 ECDSA algorithms: ecdsa-sha2-nistp256/384/521. These have been supported by OpenSSH since release 5.7. To check whether a server is using the weak ssh-rsa public key algorithm for host authentication, try to connect to it after removing the ssh-rsa algorithm from ssh(1)'s allowed list: ssh -oHostKeyAlgorithms=-ssh-rsa user@host If the host key verification fails and no other supported host key types are available, the server software on that host should be upgraded. A future release of OpenSSH will enable UpdateHostKeys by default to allow the client to automatically migrate to better algorithms. Users may consider enabling this option manually. [1] "SHA-1 is a Shambles: First Chosen-Prefix Collision on SHA-1 and Application to the PGP Web of Trust" Leurent, G and Peyrin, T (2020) https://eprint.iacr.org/2020/014.pdf Security ======== * ssh(1), sshd(8), ssh-keygen(1): this release removes the "ssh-rsa" (RSA/SHA1) algorithm from those accepted for certificate signatures (i.e. the client and server CASignatureAlgorithms option) and will use the rsa-sha2-512 signature algorithm by default when the ssh-keygen(1) CA signs new certificates. Certificates are at special risk to the aforementioned SHA1 collision vulnerability as an attacker has effectively unlimited time in which to craft a collision that yields them a valid certificate, far more than the relatively brief LoginGraceTime window that they have to forge a host key signature. The OpenSSH certificate format includes a CA-specified (typically random) nonce value near the start of the certificate that should make exploitation of chosen-prefix collisions in this context challenging, as the attacker does not have full control over the prefix that actually gets signed. Nonetheless, SHA1 is now a demonstrably broken algorithm and futher improvements in attacks are highly likely. OpenSSH releases prior to 7.2 do not support the newer RSA/SHA2 algorithms and will refuse to accept certificates signed by an OpenSSH 8.2+ CA using RSA keys unless the unsafe algorithm is explicitly selected during signing ("ssh-keygen -t ssh-rsa"). Older clients/servers may use another CA key type such as ssh-ed25519 (supported since OpenSSH 6.5) or one of the ecdsa-sha2-nistp256/384/521 types (supported since OpenSSH 5.7) instead if they cannot be upgraded. Potentially-incompatible changes ================================ This release includes a number of changes that may affect existing configurations: * ssh(1), sshd(8): the above removal of "ssh-rsa" from the accepted CASignatureAlgorithms list. * ssh(1), sshd(8): this release removes diffie-hellman-group14-sha1 from the default key exchange proposal for both the client and server. * ssh-keygen(1): the command-line options related to the generation and screening of safe prime numbers used by the diffie-hellman-group-exchange-* key exchange algorithms have changed. Most options have been folded under the -O flag. * sshd(8): the sshd listener process title visible to ps(1) has changed to include information about the number of connections that are currently attempting authentication and the limits configured by MaxStartups. * ssh-sk-helper(8): this is a new binary. It is used by the FIDO/U2F support to provide address-space isolation for token middleware libraries (including the internal one). It needs to be installed in the expected path, typically under /usr/libexec or similar. Changes since OpenSSH 8.1 ========================= This release contains some significant new features. FIDO/U2F Support ---------------- This release adds support for FIDO/U2F hardware authenticators to OpenSSH. U2F/FIDO are open standards for inexpensive two-factor authentication hardware that are widely used for website authentication. In OpenSSH FIDO devices are supported by new public key types "ecdsa-sk" and "ed25519-sk", along with corresponding certificate types. ssh-keygen(1) may be used to generate a FIDO token-backed key, after which they may be used much like any other key type supported by OpenSSH, so long as the hardware token is attached when the keys are used. FIDO tokens also generally require the user explicitly authorise operations by touching or tapping them. Generating a FIDO key requires the token be attached, and will usually require the user tap the token to confirm the operation: $ ssh-keygen -t ecdsa-sk -f ~/.ssh/id_ecdsa_sk Generating public/private ecdsa-sk key pair. You may need to touch your security key to authorize key generation. Enter file in which to save the key (/home/djm/.ssh/id_ecdsa_sk): Enter passphrase (empty for no passphrase): Enter same passphrase again: Your identification has been saved in /home/djm/.ssh/id_ecdsa_sk Your public key has been saved in /home/djm/.ssh/id_ecdsa_sk.pub This will yield a public and private key-pair. The private key file should be useless to an attacker who does not have access to the physical token. After generation, this key may be used like any other supported key in OpenSSH and may be listed in authorized_keys, added to ssh-agent(1), etc. The only additional stipulation is that the FIDO token that the key belongs to must be attached when the key is used. FIDO tokens are most commonly connected via USB but may be attached via other means such as Bluetooth or NFC. In OpenSSH, communication with the token is managed via a middleware library, specified by the SecurityKeyProvider directive in ssh/sshd_config(5) or the $SSH_SK_PROVIDER environment variable for ssh-keygen(1) and ssh-add(1). The API for this middleware is documented in the sk-api.h and PROTOCOL.u2f files in the source distribution. OpenSSH includes a middleware ("SecurityKeyProvider=internal") with support for USB tokens. It is automatically enabled in OpenBSD and may be enabled in portable OpenSSH via the configure flag --with-security-key-builtin. If the internal middleware is enabled then it is automatically used by default. This internal middleware requires that libfido2 (https://github.com/Yubico/libfido2) and its dependencies be installed. We recommend that packagers of portable OpenSSH enable the built-in middleware, as it provides the lowest-friction experience for users. Note: FIDO/U2F tokens are required to implement the ECDSA-P256 "ecdsa-sk" key type, but hardware support for Ed25519 "ed25519-sk" is less common. Similarly, not all hardware tokens support some of the optional features such as resident keys. The protocol-level changes to support FIDO/U2F keys in SSH are documented in the PROTOCOL.u2f file in the OpenSSH source distribution. There are a number of supporting changes to this feature: * ssh-keygen(1): add a "no-touch-required" option when generating FIDO-hosted keys, that disables their default behaviour of requiring a physical touch/tap on the token during authentication. Note: not all tokens support disabling the touch requirement. * sshd(8): add a sshd_config PubkeyAuthOptions directive that collects miscellaneous public key authentication-related options for sshd(8). At present it supports only a single option "no-touch-required". This causes sshd to skip its default check for FIDO/U2F keys that the signature was authorised by a touch or press event on the token hardware. * ssh(1), sshd(8), ssh-keygen(1): add a "no-touch-required" option for authorized_keys and a similar extension for certificates. This option disables the default requirement that FIDO key signatures attest that the user touched their key to authorize them, mirroring the similar PubkeyAuthOptions sshd_config option. * ssh-keygen(1): add support for the writing the FIDO attestation information that is returned when new keys are generated via the "-O write-attestation=/path" option. FIDO attestation certificates may be used to verify that a FIDO key is hosted in trusted hardware. OpenSSH does not currently make use of this information, beyond optionally writing it to disk. FIDO2 resident keys ------------------- FIDO/U2F OpenSSH keys consist of two parts: a "key handle" part stored in the private key file on disk, and a per-device private key that is unique to each FIDO/U2F token and that cannot be exported from the token hardware. These are combined by the hardware at authentication time to derive the real key that is used to sign authentication challenges. For tokens that are required to move between computers, it can be cumbersome to have to move the private key file first. To avoid this requirement, tokens implementing the newer FIDO2 standard support "resident keys", where it is possible to effectively retrieve the key handle part of the key from the hardware. OpenSSH supports this feature, allowing resident keys to be generated using the ssh-keygen(1) "-O resident" flag. This will produce a public/private key pair as usual, but it will be possible to retrieve the private key part from the token later. This may be done using "ssh-keygen -K", which will download all available resident keys from the tokens attached to the host and write public/private key files for them. It is also possible to download and add resident keys directly to ssh-agent(1) without writing files to the file-system using "ssh-add -K". Resident keys are indexed on the token by the application string and user ID. By default, OpenSSH uses an application string of "ssh:" and an empty user ID. If multiple resident keys on a single token are desired then it may be necessary to override one or both of these defaults using the ssh-keygen(1) "-O application=" or "-O user=" options. Note: OpenSSH will only download and use resident keys whose application string begins with "ssh:" Storing both parts of a key on a FIDO token increases the likelihood of an attacker being able to use a stolen token device. For this reason, tokens should enforce PIN authentication before allowing download of keys, and users should set a PIN on their tokens before creating any resident keys. Other New Features ------------------ * sshd(8): add an Include sshd_config keyword that allows including additional configuration files via glob(3) patterns. bz2468 * ssh(1)/sshd(8): make the LE (low effort) DSCP code point available via the IPQoS directive; bz2986, * ssh(1): when AddKeysToAgent=yes is set and the key contains no comment, add the key to the agent with the key's path as the comment. bz2564 * ssh-keygen(1), ssh-agent(1): expose PKCS#11 key labels and X.509 subjects as key comments, rather than simply listing the PKCS#11 provider library path. PR138 * ssh-keygen(1): allow PEM export of DSA and ECDSA keys; bz3091 * ssh(1), sshd(8): make zlib compile-time optional, available via the Makefile.inc ZLIB flag on OpenBSD or via the --with-zlib configure option for OpenSSH portable. * sshd(8): when clients get denied by MaxStartups, send a notification prior to the SSH2 protocol banner according to RFC4253 section 4.2. * ssh(1), ssh-agent(1): when invoking the $SSH_ASKPASS prompt program, pass a hint to the program to describe the type of desired prompt. The possible values are "confirm" (indicating that a yes/no confirmation dialog with no text entry should be shown), "none" (to indicate an informational message only), or blank for the original ssh-askpass behaviour of requesting a password/phrase. * ssh(1): allow forwarding a different agent socket to the path specified by $SSH_AUTH_SOCK, by extending the existing ForwardAgent option to accepting an explicit path or the name of an environment variable in addition to yes/no. * ssh-keygen(1): add a new signature operations "find-principals" to look up the principal associated with a signature from an allowed- signers file. * sshd(8): expose the number of currently-authenticating connections along with the MaxStartups limit in the process title visible to "ps". Bugfixes -------- * sshd(8): make ClientAliveCountMax=0 have sensible semantics: it will now disable connection killing entirely rather than the current behaviour of instantly killing the connection after the first liveness test regardless of success. bz2627 * sshd(8): clarify order of AllowUsers / DenyUsers vs AllowGroups / DenyGroups in the sshd(8) manual page. bz1690 * sshd(8): better describe HashKnownHosts in the manual page. bz2560 * sshd(8): clarify that that permitopen=/PermitOpen do no name or address translation in the manual page. bz3099 * sshd(8): allow the UpdateHostKeys feature to function when multiple known_hosts files are in use. When updating host keys, ssh will now search subsequent known_hosts files, but will add updated host keys to the first specified file only. bz2738 * All: replace all calls to signal(2) with a wrapper around sigaction(2). This wrapper blocks all other signals during the handler preventing races between handlers, and sets SA_RESTART which should reduce the potential for short read/write operations. * sftp(1): fix a race condition in the SIGCHILD handler that could turn in to a kill(-1); bz3084 * sshd(8): fix a case where valid (but extremely large) SSH channel IDs were being incorrectly rejected. bz3098 * ssh(1): when checking host key fingerprints as answers to new hostkey prompts, ignore whitespace surrounding the fingerprint itself. * All: wait for file descriptors to be readable or writeable during non-blocking connect, not just readable. Prevents a timeout when the server doesn't immediately send a banner (e.g. multiplexers like sslh) * sshd_config(5): document the sntrup4591761x25519-sha512@tinyssh.org key exchange algorithm. PR#151
2020-02-27 03:21:35 +03:00
#include <sys/queue.h>
import 5.2 from ftp.openbsd.org
2009-06-08 02:19:00 +04:00
#define MAX_PORTS 256 /* Max # ports. */
/* permit_root_login */
#define PERMIT_NOT_SET -1
#define PERMIT_NO 0
#define PERMIT_FORCED_ONLY 1
#define PERMIT_NO_PASSWD 2
#define PERMIT_YES 3
new openssh: See http://www.openssh.com/txt/release-5.9
2011-09-07 00:16:49 +04:00
/* use_privsep */
#define PRIVSEP_OFF 0
#define PRIVSEP_ON 1
From ftp.openbsd.org
2012-12-12 20:52:18 +04:00
#define PRIVSEP_NOSANDBOX 2
new openssh: See http://www.openssh.com/txt/release-5.9
2011-09-07 00:16:49 +04:00
Potentially-incompatible changes ================================ This release includes a number of changes that may affect existing configurations: * ssh(1): delete SSH protocol version 1 support, associated configuration options and documentation. * ssh(1)/sshd(8): remove support for the hmac-ripemd160 MAC. * ssh(1)/sshd(8): remove support for the arcfour, blowfish and CAST ciphers. * Refuse RSA keys <1024 bits in length and improve reporting for keys that do not meet this requirement. * ssh(1): do not offer CBC ciphers by default. Changes since OpenSSH 7.5 ========================= This is primarily a bugfix release. It also contains substantial internal refactoring. Security -------- * sftp-server(8): in read-only mode, sftp-server was incorrectly permitting creation of zero-length files. Reported by Michal Zalewski. New Features ------------ * ssh(1): add RemoteCommand option to specify a command in the ssh config file instead of giving it on the client's command line. This allows the configuration file to specify the command that will be executed on the remote host. * sshd(8): add ExposeAuthInfo option that enables writing details of the authentication methods used (including public keys where applicable) to a file that is exposed via a $SSH_USER_AUTH environment variable in the subsequent session. * ssh(1): add support for reverse dynamic forwarding. In this mode, ssh will act as a SOCKS4/5 proxy and forward connections to destinations requested by the remote SOCKS client. This mode is requested using extended syntax for the -R and RemoteForward options and, because it is implemented solely at the client, does not require the server be updated to be supported. * sshd(8): allow LogLevel directive in sshd_config Match blocks; bz#2717 * ssh-keygen(1): allow inclusion of arbitrary string or flag certificate extensions and critical options. * ssh-keygen(1): allow ssh-keygen to use a key held in ssh-agent as a CA when signing certificates. bz#2377 * ssh(1)/sshd(8): allow IPQoS=none in ssh/sshd to not set an explicit ToS/DSCP value and just use the operating system default. * ssh-add(1): added -q option to make ssh-add quiet on success. * ssh(1): expand the StrictHostKeyChecking option with two new settings. The first "accept-new" will automatically accept hitherto-unseen keys but will refuse connections for changed or invalid hostkeys. This is a safer subset of the current behaviour of StrictHostKeyChecking=no. The second setting "off", is a synonym for the current behaviour of StrictHostKeyChecking=no: accept new host keys, and continue connection for hosts with incorrect hostkeys. A future release will change the meaning of StrictHostKeyChecking=no to the behaviour of "accept-new". bz#2400 * ssh(1): add SyslogFacility option to ssh(1) matching the equivalent option in sshd(8). bz#2705 Bugfixes -------- * ssh(1): use HostKeyAlias if specified instead of hostname for matching host certificate principal names; bz#2728 * sftp(1): implement sorting for globbed ls; bz#2649 * ssh(1): add a user@host prefix to client's "Permission denied" messages, useful in particular when using "stacked" connections (e.g. ssh -J) where it's not clear which host is denying. bz#2720 * ssh(1): accept unknown EXT_INFO extension values that contain \0 characters. These are legal, but would previously cause fatal connection errors if received. * ssh(1)/sshd(8): repair compression statistics printed at connection exit * sftp(1): print '?' instead of incorrect link count (that the protocol doesn't provide) for remote listings. bz#2710 * ssh(1): return failure rather than fatal() for more cases during session multiplexing negotiations. Causes the session to fall back to a non-mux connection if they occur. bz#2707 * ssh(1): mention that the server may send debug messages to explain public key authentication problems under some circumstances; bz#2709 * Translate OpenSSL error codes to better report incorrect passphrase errors when loading private keys; bz#2699 * sshd(8): adjust compatibility patterns for WinSCP to correctly identify versions that implement only the legacy DH group exchange scheme. bz#2748 * ssh(1): print the "Killed by signal 1" message only at LogLevel verbose so that it is not shown at the default level; prevents it from appearing during ssh -J and equivalent ProxyCommand configs. bz#1906, bz#2744 * ssh-keygen(1): when generating all hostkeys (ssh-keygen -A), clobber existing keys if they exist but are zero length. zero-length keys could previously be made if ssh-keygen failed or was interrupted part way through generating them. bz#2561 * ssh(1): fix pledge(2) violation in the escape sequence "~&" used to place the current session in the background. * ssh-keyscan(1): avoid double-close() on file descriptors; bz#2734 * sshd(8): avoid reliance on shared use of pointers shared between monitor and child sshd processes. bz#2704 * sshd_config(8): document available AuthenticationMethods; bz#2453 * ssh(1): avoid truncation in some login prompts; bz#2768 * sshd(8): Fix various compilations failures, inc bz#2767 * ssh(1): make "--" before the hostname terminate argument processing after the hostname too. * ssh-keygen(1): switch from aes256-cbc to aes256-ctr for encrypting new-style private keys. Fixes problems related to private key handling for no-OpenSSL builds. bz#2754 * ssh(1): warn and do not attempt to use keys when the public and private halves do not match. bz#2737 * sftp(1): don't print verbose error message when ssh disconnects from under sftp. bz#2750 * sshd(8): fix keepalive scheduling problem: activity on a forwarded port from preventing the keepalive from being sent; bz#2756 * sshd(8): when started without root privileges, don't require the privilege separation user or path to exist. Makes running the regression tests easier without touching the filesystem. * Make integrity.sh regression tests more robust against timeouts. bz#2658 * ssh(1)/sshd(8): correctness fix for channels implementation: accept channel IDs greater than 0x7FFFFFFF. Portability ----------- * sshd(9): drop two more privileges in the Solaris sandbox: PRIV_DAX_ACCESS and PRIV_SYS_IB_INFO; bz#2723 * sshd(8): expose list of completed authentication methods to PAM via the SSH_AUTH_INFO_0 PAM environment variable. bz#2408 * ssh(1)/sshd(8): fix several problems in the tun/tap forwarding code, mostly to do with host/network byte order confusion. bz#2735 * Add --with-cflags-after and --with-ldflags-after configure flags to allow setting CFLAGS/LDFLAGS after configure has completed. These are useful for setting sanitiser/fuzzing options that may interfere with configure's operation. * sshd(8): avoid Linux seccomp violations on ppc64le over the socketcall syscall. * Fix use of ldns when using ldns-config; bz#2697 * configure: set cache variables when cross-compiling. The cross- compiling fallback message was saying it assumed the test passed, but it wasn't actually set the cache variables and this would cause later tests to fail. * Add clang libFuzzer harnesses for public key parsing and signature verification.
2017-10-07 22:36:11 +03:00
/* PermitOpen */
#define PERMITOPEN_ANY 0
#define PERMITOPEN_NONE -2
OpenSSH 8.3 was released on 2020-05-27. It is available from the mirrors listed at https://www.openssh.com/. OpenSSH is a 100% complete SSH protocol 2.0 implementation and includes sftp client and server support. Once again, we would like to thank the OpenSSH community for their continued support of the project, especially those who contributed code or patches, reported bugs, tested snapshots or donated to the project. More information on donations may be found at: https://www.openssh.com/donations.html Future deprecation notice ========================= It is now possible[1] to perform chosen-prefix attacks against the SHA-1 algorithm for less than USD$50K. For this reason, we will be disabling the "ssh-rsa" public key signature algorithm by default in a near-future release. This algorithm is unfortunately still used widely despite the existence of better alternatives, being the only remaining public key signature algorithm specified by the original SSH RFCs. The better alternatives include: * The RFC8332 RSA SHA-2 signature algorithms rsa-sha2-256/512. These algorithms have the advantage of using the same key type as "ssh-rsa" but use the safe SHA-2 hash algorithms. These have been supported since OpenSSH 7.2 and are already used by default if the client and server support them. * The ssh-ed25519 signature algorithm. It has been supported in OpenSSH since release 6.5. * The RFC5656 ECDSA algorithms: ecdsa-sha2-nistp256/384/521. These have been supported by OpenSSH since release 5.7. To check whether a server is using the weak ssh-rsa public key algorithm, for host authentication, try to connect to it after removing the ssh-rsa algorithm from ssh(1)'s allowed list: ssh -oHostKeyAlgorithms=-ssh-rsa user@host If the host key verification fails and no other supported host key types are available, the server software on that host should be upgraded. A future release of OpenSSH will enable UpdateHostKeys by default to allow the client to automatically migrate to better algorithms. Users may consider enabling this option manually. Vendors of devices that implement the SSH protocol should ensure that they support the new signature algorithms for RSA keys. [1] "SHA-1 is a Shambles: First Chosen-Prefix Collision on SHA-1 and Application to the PGP Web of Trust" Leurent, G and Peyrin, T (2020) https://eprint.iacr.org/2020/014.pdf Security ======== * scp(1): when receiving files, scp(1) could be become desynchronised if a utimes(2) system call failed. This could allow file contents to be interpreted as file metadata and thereby permit an adversary to craft a file system that, when copied with scp(1) in a configuration that caused utimes(2) to fail (e.g. under a SELinux policy or syscall sandbox), transferred different file names and contents to the actual file system layout. Exploitation of this is not likely as utimes(2) does not fail under normal circumstances. Successful exploitation is not silent - the output of scp(1) would show transfer errors followed by the actual file(s) that were received. Finally, filenames returned from the peer are (since openssh-8.0) matched against the user's requested destination, thereby disallowing a successful exploit from writing files outside the user's selected target glob (or directory, in the case of a recursive transfer). This ensures that this attack can achieve no more than a hostile peer is already able to achieve within the scp protocol. Potentially-incompatible changes ================================ This release includes a number of changes that may affect existing configurations: * sftp(1): reject an argument of "-1" in the same way as ssh(1) and scp(1) do instead of accepting and silently ignoring it. Changes since OpenSSH 8.2 ========================= The focus of this release is bug fixing. New Features ------------ * sshd(8): make IgnoreRhosts a tri-state option: "yes" to ignore rhosts/shosts, "no" allow rhosts/shosts or (new) "shosts-only" to allow .shosts files but not .rhosts. * sshd(8): allow the IgnoreRhosts directive to appear anywhere in a sshd_config, not just before any Match blocks; bz3148 * ssh(1): add %TOKEN percent expansion for the LocalFoward and RemoteForward keywords when used for Unix domain socket forwarding. bz#3014 * all: allow loading public keys from the unencrypted envelope of a private key file if no corresponding public key file is present. * ssh(1), sshd(8): prefer to use chacha20 from libcrypto where possible instead of the (slower) portable C implementation included in OpenSSH. * ssh-keygen(1): add ability to dump the contents of a binary key revocation list via "ssh-keygen -lQf /path" bz#3132 Bugfixes -------- * ssh(1): fix IdentitiesOnly=yes to also apply to keys loaded from a PKCS11Provider; bz#3141 * ssh-keygen(1): avoid NULL dereference when trying to convert an invalid RFC4716 private key. * scp(1): when performing remote-to-remote copies using "scp -3", start the second ssh(1) channel with BatchMode=yes enabled to avoid confusing and non-deterministic ordering of prompts. * ssh(1), ssh-keygen(1): when signing a challenge using a FIDO token, perform hashing of the message to be signed in the middleware layer rather than in OpenSSH code. This permits the use of security key middlewares that perform the hashing implicitly, such as Windows Hello. * ssh(1): fix incorrect error message for "too many known hosts files." bz#3149 * ssh(1): make failures when establishing "Tunnel" forwarding terminate the connection when ExitOnForwardFailure is enabled; bz#3116 * ssh-keygen(1): fix printing of fingerprints on private keys and add a regression test for same. * sshd(8): document order of checking AuthorizedKeysFile (first) and AuthorizedKeysCommand (subsequently, if the file doesn't match); bz#3134 * sshd(8): document that /etc/hosts.equiv and /etc/shosts.equiv are not considered for HostbasedAuthentication when the target user is root; bz#3148 * ssh(1), ssh-keygen(1): fix NULL dereference in private certificate key parsing (oss-fuzz #20074). * ssh(1), sshd(8): more consistency between sets of %TOKENS are accepted in various configuration options. * ssh(1), ssh-keygen(1): improve error messages for some common PKCS#11 C_Login failure cases; bz#3130 * ssh(1), sshd(8): make error messages for problems during SSH banner exchange consistent with other SSH transport-layer error messages and ensure they include the relevant IP addresses bz#3129 * various: fix a number of spelling errors in comments and debug/error messages * ssh-keygen(1), ssh-add(1): when downloading FIDO2 resident keys from a token, don't prompt for a PIN until the token has told us that it needs one. Avoids double-prompting on devices that implement on-device authentication. * sshd(8), ssh-keygen(1): no-touch-required FIDO certificate option should be an extension, not a critical option. * ssh(1), ssh-keygen(1), ssh-add(1): offer a better error message when trying to use a FIDO key function and SecurityKeyProvider is empty. * ssh-add(1), ssh-agent(8): ensure that a key lifetime fits within the values allowed by the wire format (u32). Prevents integer wraparound of the timeout values. bz#3119 * ssh(1): detect and prevent trivial configuration loops when using ProxyJump. bz#3057. Portability ----------- * Detect systems where signals flagged with SA_RESTART will interrupt select(2). POSIX permits implementations to choose whether select(2) will return when interrupted with a SA_RESTART-flagged signal, but OpenSSH requires interrupting behaviour. * Several compilation fixes for HP/UX and AIX. * On platforms that do not support setting process-wide routing domains (all excepting OpenBSD at present), fail to accept a configuration attempts to set one at process start time rather than fatally erroring at run time. bz#3126 * Improve detection of egrep (used in regression tests) on platforms that offer a poor default one (e.g. Solaris). * A number of shell portability fixes for the regression tests. * Fix theoretical infinite loop in the glob(3) replacement implementation. * Fix seccomp sandbox compilation problems for some Linux configurations bz#3085 * Improved detection of libfido2 and some compilation fixes for some configurations when --with-security-key-builtin is selected.
2020-05-28 20:02:58 +03:00
/* IgnoreRhosts */
#define IGNORE_RHOSTS_NO 0
#define IGNORE_RHOSTS_YES 1
#define IGNORE_RHOSTS_SHOSTS 2
import 5.2 from ftp.openbsd.org
2009-06-08 02:19:00 +04:00
#define DEFAULT_AUTH_FAIL_MAX 6 /* Default for MaxAuthTries */
#define DEFAULT_SESSIONS_MAX 10 /* Default for MaxSessions */
/* Magic name for internal sftp-server */
#define INTERNAL_SFTP_NAME "internal-sftp"
OpenSSH 8.2/8.2p1 (2020-02-14) OpenSSH 8.2 was released on 2020-02-14. It is available from the mirrors listed at https://www.openssh.com/. OpenSSH is a 100% complete SSH protocol 2.0 implementation and includes sftp client and server support. Once again, we would like to thank the OpenSSH community for their continued support of the project, especially those who contributed code or patches, reported bugs, tested snapshots or donated to the project. More information on donations may be found at: https://www.openssh.com/donations.html Future deprecation notice ========================= It is now possible[1] to perform chosen-prefix attacks against the SHA-1 hash algorithm for less than USD$50K. For this reason, we will be disabling the "ssh-rsa" public key signature algorithm that depends on SHA-1 by default in a near-future release. This algorithm is unfortunately still used widely despite the existence of better alternatives, being the only remaining public key signature algorithm specified by the original SSH RFCs. The better alternatives include: * The RFC8332 RSA SHA-2 signature algorithms rsa-sha2-256/512. These algorithms have the advantage of using the same key type as "ssh-rsa" but use the safe SHA-2 hash algorithms. These have been supported since OpenSSH 7.2 and are already used by default if the client and server support them. * The ssh-ed25519 signature algorithm. It has been supported in OpenSSH since release 6.5. * The RFC5656 ECDSA algorithms: ecdsa-sha2-nistp256/384/521. These have been supported by OpenSSH since release 5.7. To check whether a server is using the weak ssh-rsa public key algorithm for host authentication, try to connect to it after removing the ssh-rsa algorithm from ssh(1)'s allowed list: ssh -oHostKeyAlgorithms=-ssh-rsa user@host If the host key verification fails and no other supported host key types are available, the server software on that host should be upgraded. A future release of OpenSSH will enable UpdateHostKeys by default to allow the client to automatically migrate to better algorithms. Users may consider enabling this option manually. [1] "SHA-1 is a Shambles: First Chosen-Prefix Collision on SHA-1 and Application to the PGP Web of Trust" Leurent, G and Peyrin, T (2020) https://eprint.iacr.org/2020/014.pdf Security ======== * ssh(1), sshd(8), ssh-keygen(1): this release removes the "ssh-rsa" (RSA/SHA1) algorithm from those accepted for certificate signatures (i.e. the client and server CASignatureAlgorithms option) and will use the rsa-sha2-512 signature algorithm by default when the ssh-keygen(1) CA signs new certificates. Certificates are at special risk to the aforementioned SHA1 collision vulnerability as an attacker has effectively unlimited time in which to craft a collision that yields them a valid certificate, far more than the relatively brief LoginGraceTime window that they have to forge a host key signature. The OpenSSH certificate format includes a CA-specified (typically random) nonce value near the start of the certificate that should make exploitation of chosen-prefix collisions in this context challenging, as the attacker does not have full control over the prefix that actually gets signed. Nonetheless, SHA1 is now a demonstrably broken algorithm and futher improvements in attacks are highly likely. OpenSSH releases prior to 7.2 do not support the newer RSA/SHA2 algorithms and will refuse to accept certificates signed by an OpenSSH 8.2+ CA using RSA keys unless the unsafe algorithm is explicitly selected during signing ("ssh-keygen -t ssh-rsa"). Older clients/servers may use another CA key type such as ssh-ed25519 (supported since OpenSSH 6.5) or one of the ecdsa-sha2-nistp256/384/521 types (supported since OpenSSH 5.7) instead if they cannot be upgraded. Potentially-incompatible changes ================================ This release includes a number of changes that may affect existing configurations: * ssh(1), sshd(8): the above removal of "ssh-rsa" from the accepted CASignatureAlgorithms list. * ssh(1), sshd(8): this release removes diffie-hellman-group14-sha1 from the default key exchange proposal for both the client and server. * ssh-keygen(1): the command-line options related to the generation and screening of safe prime numbers used by the diffie-hellman-group-exchange-* key exchange algorithms have changed. Most options have been folded under the -O flag. * sshd(8): the sshd listener process title visible to ps(1) has changed to include information about the number of connections that are currently attempting authentication and the limits configured by MaxStartups. * ssh-sk-helper(8): this is a new binary. It is used by the FIDO/U2F support to provide address-space isolation for token middleware libraries (including the internal one). It needs to be installed in the expected path, typically under /usr/libexec or similar. Changes since OpenSSH 8.1 ========================= This release contains some significant new features. FIDO/U2F Support ---------------- This release adds support for FIDO/U2F hardware authenticators to OpenSSH. U2F/FIDO are open standards for inexpensive two-factor authentication hardware that are widely used for website authentication. In OpenSSH FIDO devices are supported by new public key types "ecdsa-sk" and "ed25519-sk", along with corresponding certificate types. ssh-keygen(1) may be used to generate a FIDO token-backed key, after which they may be used much like any other key type supported by OpenSSH, so long as the hardware token is attached when the keys are used. FIDO tokens also generally require the user explicitly authorise operations by touching or tapping them. Generating a FIDO key requires the token be attached, and will usually require the user tap the token to confirm the operation: $ ssh-keygen -t ecdsa-sk -f ~/.ssh/id_ecdsa_sk Generating public/private ecdsa-sk key pair. You may need to touch your security key to authorize key generation. Enter file in which to save the key (/home/djm/.ssh/id_ecdsa_sk): Enter passphrase (empty for no passphrase): Enter same passphrase again: Your identification has been saved in /home/djm/.ssh/id_ecdsa_sk Your public key has been saved in /home/djm/.ssh/id_ecdsa_sk.pub This will yield a public and private key-pair. The private key file should be useless to an attacker who does not have access to the physical token. After generation, this key may be used like any other supported key in OpenSSH and may be listed in authorized_keys, added to ssh-agent(1), etc. The only additional stipulation is that the FIDO token that the key belongs to must be attached when the key is used. FIDO tokens are most commonly connected via USB but may be attached via other means such as Bluetooth or NFC. In OpenSSH, communication with the token is managed via a middleware library, specified by the SecurityKeyProvider directive in ssh/sshd_config(5) or the $SSH_SK_PROVIDER environment variable for ssh-keygen(1) and ssh-add(1). The API for this middleware is documented in the sk-api.h and PROTOCOL.u2f files in the source distribution. OpenSSH includes a middleware ("SecurityKeyProvider=internal") with support for USB tokens. It is automatically enabled in OpenBSD and may be enabled in portable OpenSSH via the configure flag --with-security-key-builtin. If the internal middleware is enabled then it is automatically used by default. This internal middleware requires that libfido2 (https://github.com/Yubico/libfido2) and its dependencies be installed. We recommend that packagers of portable OpenSSH enable the built-in middleware, as it provides the lowest-friction experience for users. Note: FIDO/U2F tokens are required to implement the ECDSA-P256 "ecdsa-sk" key type, but hardware support for Ed25519 "ed25519-sk" is less common. Similarly, not all hardware tokens support some of the optional features such as resident keys. The protocol-level changes to support FIDO/U2F keys in SSH are documented in the PROTOCOL.u2f file in the OpenSSH source distribution. There are a number of supporting changes to this feature: * ssh-keygen(1): add a "no-touch-required" option when generating FIDO-hosted keys, that disables their default behaviour of requiring a physical touch/tap on the token during authentication. Note: not all tokens support disabling the touch requirement. * sshd(8): add a sshd_config PubkeyAuthOptions directive that collects miscellaneous public key authentication-related options for sshd(8). At present it supports only a single option "no-touch-required". This causes sshd to skip its default check for FIDO/U2F keys that the signature was authorised by a touch or press event on the token hardware. * ssh(1), sshd(8), ssh-keygen(1): add a "no-touch-required" option for authorized_keys and a similar extension for certificates. This option disables the default requirement that FIDO key signatures attest that the user touched their key to authorize them, mirroring the similar PubkeyAuthOptions sshd_config option. * ssh-keygen(1): add support for the writing the FIDO attestation information that is returned when new keys are generated via the "-O write-attestation=/path" option. FIDO attestation certificates may be used to verify that a FIDO key is hosted in trusted hardware. OpenSSH does not currently make use of this information, beyond optionally writing it to disk. FIDO2 resident keys ------------------- FIDO/U2F OpenSSH keys consist of two parts: a "key handle" part stored in the private key file on disk, and a per-device private key that is unique to each FIDO/U2F token and that cannot be exported from the token hardware. These are combined by the hardware at authentication time to derive the real key that is used to sign authentication challenges. For tokens that are required to move between computers, it can be cumbersome to have to move the private key file first. To avoid this requirement, tokens implementing the newer FIDO2 standard support "resident keys", where it is possible to effectively retrieve the key handle part of the key from the hardware. OpenSSH supports this feature, allowing resident keys to be generated using the ssh-keygen(1) "-O resident" flag. This will produce a public/private key pair as usual, but it will be possible to retrieve the private key part from the token later. This may be done using "ssh-keygen -K", which will download all available resident keys from the tokens attached to the host and write public/private key files for them. It is also possible to download and add resident keys directly to ssh-agent(1) without writing files to the file-system using "ssh-add -K". Resident keys are indexed on the token by the application string and user ID. By default, OpenSSH uses an application string of "ssh:" and an empty user ID. If multiple resident keys on a single token are desired then it may be necessary to override one or both of these defaults using the ssh-keygen(1) "-O application=" or "-O user=" options. Note: OpenSSH will only download and use resident keys whose application string begins with "ssh:" Storing both parts of a key on a FIDO token increases the likelihood of an attacker being able to use a stolen token device. For this reason, tokens should enforce PIN authentication before allowing download of keys, and users should set a PIN on their tokens before creating any resident keys. Other New Features ------------------ * sshd(8): add an Include sshd_config keyword that allows including additional configuration files via glob(3) patterns. bz2468 * ssh(1)/sshd(8): make the LE (low effort) DSCP code point available via the IPQoS directive; bz2986, * ssh(1): when AddKeysToAgent=yes is set and the key contains no comment, add the key to the agent with the key's path as the comment. bz2564 * ssh-keygen(1), ssh-agent(1): expose PKCS#11 key labels and X.509 subjects as key comments, rather than simply listing the PKCS#11 provider library path. PR138 * ssh-keygen(1): allow PEM export of DSA and ECDSA keys; bz3091 * ssh(1), sshd(8): make zlib compile-time optional, available via the Makefile.inc ZLIB flag on OpenBSD or via the --with-zlib configure option for OpenSSH portable. * sshd(8): when clients get denied by MaxStartups, send a notification prior to the SSH2 protocol banner according to RFC4253 section 4.2. * ssh(1), ssh-agent(1): when invoking the $SSH_ASKPASS prompt program, pass a hint to the program to describe the type of desired prompt. The possible values are "confirm" (indicating that a yes/no confirmation dialog with no text entry should be shown), "none" (to indicate an informational message only), or blank for the original ssh-askpass behaviour of requesting a password/phrase. * ssh(1): allow forwarding a different agent socket to the path specified by $SSH_AUTH_SOCK, by extending the existing ForwardAgent option to accepting an explicit path or the name of an environment variable in addition to yes/no. * ssh-keygen(1): add a new signature operations "find-principals" to look up the principal associated with a signature from an allowed- signers file. * sshd(8): expose the number of currently-authenticating connections along with the MaxStartups limit in the process title visible to "ps". Bugfixes -------- * sshd(8): make ClientAliveCountMax=0 have sensible semantics: it will now disable connection killing entirely rather than the current behaviour of instantly killing the connection after the first liveness test regardless of success. bz2627 * sshd(8): clarify order of AllowUsers / DenyUsers vs AllowGroups / DenyGroups in the sshd(8) manual page. bz1690 * sshd(8): better describe HashKnownHosts in the manual page. bz2560 * sshd(8): clarify that that permitopen=/PermitOpen do no name or address translation in the manual page. bz3099 * sshd(8): allow the UpdateHostKeys feature to function when multiple known_hosts files are in use. When updating host keys, ssh will now search subsequent known_hosts files, but will add updated host keys to the first specified file only. bz2738 * All: replace all calls to signal(2) with a wrapper around sigaction(2). This wrapper blocks all other signals during the handler preventing races between handlers, and sets SA_RESTART which should reduce the potential for short read/write operations. * sftp(1): fix a race condition in the SIGCHILD handler that could turn in to a kill(-1); bz3084 * sshd(8): fix a case where valid (but extremely large) SSH channel IDs were being incorrectly rejected. bz3098 * ssh(1): when checking host key fingerprints as answers to new hostkey prompts, ignore whitespace surrounding the fingerprint itself. * All: wait for file descriptors to be readable or writeable during non-blocking connect, not just readable. Prevents a timeout when the server doesn't immediately send a banner (e.g. multiplexers like sslh) * sshd_config(5): document the sntrup4591761x25519-sha512@tinyssh.org key exchange algorithm. PR#151
2020-02-27 03:21:35 +03:00
/* PubkeyAuthOptions flags */
OpenSSH 8.4 was released on 2020-09-27. It is available from the mirrors listed at https://www.openssh.com/. OpenSSH is a 100% complete SSH protocol 2.0 implementation and includes sftp client and server support. Once again, we would like to thank the OpenSSH community for their continued support of the project, especially those who contributed code or patches, reported bugs, tested snapshots or donated to the project. More information on donations may be found at: https://www.openssh.com/donations.html Future deprecation notice ========================= It is now possible[1] to perform chosen-prefix attacks against the SHA-1 algorithm for less than USD$50K. For this reason, we will be disabling the "ssh-rsa" public key signature algorithm by default in a near-future release. This algorithm is unfortunately still used widely despite the existence of better alternatives, being the only remaining public key signature algorithm specified by the original SSH RFCs. The better alternatives include: * The RFC8332 RSA SHA-2 signature algorithms rsa-sha2-256/512. These algorithms have the advantage of using the same key type as "ssh-rsa" but use the safe SHA-2 hash algorithms. These have been supported since OpenSSH 7.2 and are already used by default if the client and server support them. * The ssh-ed25519 signature algorithm. It has been supported in OpenSSH since release 6.5. * The RFC5656 ECDSA algorithms: ecdsa-sha2-nistp256/384/521. These have been supported by OpenSSH since release 5.7. To check whether a server is using the weak ssh-rsa public key algorithm, for host authentication, try to connect to it after removing the ssh-rsa algorithm from ssh(1)'s allowed list: ssh -oHostKeyAlgorithms=-ssh-rsa user@host If the host key verification fails and no other supported host key types are available, the server software on that host should be upgraded. We intend to enable UpdateHostKeys by default in the next OpenSSH release. This will assist the client by automatically migrating to better algorithms. Users may consider enabling this option manually. [1] "SHA-1 is a Shambles: First Chosen-Prefix Collision on SHA-1 and Application to the PGP Web of Trust" Leurent, G and Peyrin, T (2020) https://eprint.iacr.org/2020/014.pdf Security ======== * ssh-agent(1): restrict ssh-agent from signing web challenges for FIDO/U2F keys. When signing messages in ssh-agent using a FIDO key that has an application string that does not start with "ssh:", ensure that the message being signed is one of the forms expected for the SSH protocol (currently public key authentication and sshsig signatures). This prevents ssh-agent forwarding on a host that has FIDO keys attached granting the ability for the remote side to sign challenges for web authentication using those keys too. Note that the converse case of web browsers signing SSH challenges is already precluded because no web RP can have the "ssh:" prefix in the application string that we require. * ssh-keygen(1): Enable FIDO 2.1 credProtect extension when generating a FIDO resident key. The recent FIDO 2.1 Client to Authenticator Protocol introduced a "credProtect" feature to better protect resident keys. We use this option to require a PIN prior to all operations that may retrieve a resident key from a FIDO token. Potentially-incompatible changes ================================ This release includes a number of changes that may affect existing configurations: * For FIDO/U2F support, OpenSSH recommends the use of libfido2 1.5.0 or greater. Older libraries have limited support at the expense of disabling particular features. These include resident keys, PIN- required keys and multiple attached tokens. * ssh-keygen(1): the format of the attestation information optionally recorded when a FIDO key is generated has changed. It now includes the authenticator data needed to validate attestation signatures. * The API between OpenSSH and the FIDO token middleware has changed and the SSH_SK_VERSION_MAJOR version has been incremented as a result. Third-party middleware libraries must support the current API version (7) to work with OpenSSH 8.4. * The portable OpenSSH distribution now requires automake to rebuild the configure script and supporting files. This is not required when simply building portable OpenSSH from a release tar file. Changes since OpenSSH 8.3 ========================= New features ------------ * ssh(1), ssh-keygen(1): support for FIDO keys that require a PIN for each use. These keys may be generated using ssh-keygen using a new "verify-required" option. When a PIN-required key is used, the user will be prompted for a PIN to complete the signature operation. * sshd(8): authorized_keys now supports a new "verify-required" option to require FIDO signatures assert that the token verified that the user was present before making the signature. The FIDO protocol supports multiple methods for user-verification, but currently OpenSSH only supports PIN verification. * sshd(8), ssh-keygen(1): add support for verifying FIDO webauthn signatures. Webauthn is a standard for using FIDO keys in web browsers. These signatures are a slightly different format to plain FIDO signatures and thus require explicit support. * ssh(1): allow some keywords to expand shell-style ${ENV} environment variables. The supported keywords are CertificateFile, ControlPath, IdentityAgent and IdentityFile, plus LocalForward and RemoteForward when used for Unix domain socket paths. bz#3140 * ssh(1), ssh-agent(1): allow some additional control over the use of ssh-askpass via a new $SSH_ASKPASS_REQUIRE environment variable, including forcibly enabling and disabling its use. bz#69 * ssh(1): allow ssh_config(5)'s AddKeysToAgent keyword accept a time limit for keys in addition to its current flag options. Time- limited keys will automatically be removed from ssh-agent after their expiry time has passed. * scp(1), sftp(1): allow the -A flag to explicitly enable agent forwarding in scp and sftp. The default remains to not forward an agent, even when ssh_config enables it. * ssh(1): add a '%k' TOKEN that expands to the effective HostKey of the destination. This allows, e.g., keeping host keys in individual files using "UserKnownHostsFile ~/.ssh/known_hosts.d/%k". bz#1654 * ssh(1): add %-TOKEN, environment variable and tilde expansion to the UserKnownHostsFile directive, allowing the path to be completed by the configuration (e.g. bz#1654) * ssh-keygen(1): allow "ssh-add -d -" to read keys to be deleted from stdin. bz#3180 * sshd(8): improve logging for MaxStartups connection throttling. sshd will now log when it starts and stops throttling and periodically while in this state. bz#3055 Bugfixes -------- * ssh(1), ssh-keygen(1): better support for multiple attached FIDO tokens. In cases where OpenSSH cannot unambiguously determine which token to direct a request to, the user is now required to select a token by touching it. In cases of operations that require a PIN to be verified, this avoids sending the wrong PIN to the wrong token and incrementing the token's PIN failure counter (tokens effectively erase their keys after too many PIN failures). * sshd(8): fix Include before Match in sshd_config; bz#3122 * ssh(1): close stdin/out/error when forking after authentication completes ("ssh -f ...") bz#3137 * ssh(1), sshd(8): limit the amount of channel input data buffered, avoiding peers that advertise large windows but are slow to read from causing high memory consumption. * ssh-agent(1): handle multiple requests sent in a single write() to the agent. * sshd(8): allow sshd_config longer than 256k * sshd(8): avoid spurious "Unable to load host key" message when sshd load a private key but no public counterpart * ssh(1): prefer the default hostkey algorithm list whenever we have a hostkey that matches its best-preference algorithm. * sshd(1): when ordering the hostkey algorithms to request from a server, prefer certificate types if the known_hosts files contain a key marked as a @cert-authority; bz#3157 * ssh(1): perform host key fingerprint comparisons for the "Are you sure you want to continue connecting (yes/no/[fingerprint])?" prompt with case sensitivity. * sshd(8): ensure that address/masklen mismatches in sshd_config yield fatal errors at daemon start time rather than later when they are evaluated. * ssh-keygen(1): ensure that certificate extensions are lexically sorted. Previously if the user specified a custom extension then the everything would be in order except the custom ones. bz#3198 * ssh(1): also compare username when checking for JumpHost loops. bz#3057 * ssh-keygen(1): preserve group/world read permission on known_hosts files across runs of "ssh-keygen -Rf /path". The old behaviour was to remove all rights for group/other. bz#3146 * ssh-keygen(1): Mention the [-a rounds] flag in the ssh-keygen manual page and usage(). * sshd(8): explicitly construct path to ~/.ssh/rc rather than relying on it being relative to the current directory, so that it can still be found if the shell startup changes its directory. bz#3185 * sshd(8): when redirecting sshd's log output to a file, undo this redirection after the session child process is forked(). Fixes missing log messages when using this feature under some circumstances. * sshd(8): start ClientAliveInterval bookkeeping before first pass through select() loop; fixed theoretical case where busy sshd may ignore timeouts from client. * ssh(1): only reset the ServerAliveInterval check when we receive traffic from the server and ignore traffic from a port forwarding client, preventing a client from keeping a connection alive when it should be terminated. bz#2265 * ssh-keygen(1): avoid spurious error message when ssh-keygen creates files outside ~/.ssh * sftp-client(1): fix off-by-one error that caused sftp downloads to make one more concurrent request that desired. This prevented using sftp(1) in unpipelined request/response mode, which is useful when debugging. bz#3054 * ssh(1), sshd(8): handle EINTR in waitfd() and timeout_connect() helpers. bz#3071 * ssh(1), ssh-keygen(1): defer creation of ~/.ssh until we attempt to write to it so we don't leave an empty .ssh directory when it's not needed. bz#3156 * ssh(1), sshd(8): fix multiplier when parsing time specifications when handling seconds after other units. bz#3171 Portability ----------- * sshd(8): always send any PAM account messages. If the PAM account stack returns any messages, always send them to the user and not just if the check succeeds. bz#2049 * Implement some backwards compatibility for libfido2 libraries older than 1.5.0. Note that use of an older library will result in the loss of certain features including resident key support, PIN support and support for multiple attached tokens. * configure fixes for XCode 12 * gnome-ssh-askpass3: ensure the "close" button is not focused by default for SSH_ASKPASS_PROMPT=none prompts. Avoids space/enter accidentally dismissing FIDO touch notifications. * gnome-ssh-askpass3: allow some control over textarea colour via $GNOME_SSH_ASKPASS_FG_COLOR and $GNOME_SSH_ASKPASS_BG_COLOR environment variables. * sshd(8): document another PAM spec problem in a frustrated comment * sshd(8): support NetBSD's utmpx.ut_ss address field. bz#960 * Add the ssh-sk-helper binary and its manpage to the RPM spec file * Detect the Frankenstein monster of Linux/X32 and allow the sandbox to function there. bz#3085
2020-12-04 21:40:04 +03:00
#define PUBKEYAUTH_TOUCH_REQUIRED (1)
#define PUBKEYAUTH_VERIFY_REQUIRED (1<<1)
OpenSSH 8.2/8.2p1 (2020-02-14) OpenSSH 8.2 was released on 2020-02-14. It is available from the mirrors listed at https://www.openssh.com/. OpenSSH is a 100% complete SSH protocol 2.0 implementation and includes sftp client and server support. Once again, we would like to thank the OpenSSH community for their continued support of the project, especially those who contributed code or patches, reported bugs, tested snapshots or donated to the project. More information on donations may be found at: https://www.openssh.com/donations.html Future deprecation notice ========================= It is now possible[1] to perform chosen-prefix attacks against the SHA-1 hash algorithm for less than USD$50K. For this reason, we will be disabling the "ssh-rsa" public key signature algorithm that depends on SHA-1 by default in a near-future release. This algorithm is unfortunately still used widely despite the existence of better alternatives, being the only remaining public key signature algorithm specified by the original SSH RFCs. The better alternatives include: * The RFC8332 RSA SHA-2 signature algorithms rsa-sha2-256/512. These algorithms have the advantage of using the same key type as "ssh-rsa" but use the safe SHA-2 hash algorithms. These have been supported since OpenSSH 7.2 and are already used by default if the client and server support them. * The ssh-ed25519 signature algorithm. It has been supported in OpenSSH since release 6.5. * The RFC5656 ECDSA algorithms: ecdsa-sha2-nistp256/384/521. These have been supported by OpenSSH since release 5.7. To check whether a server is using the weak ssh-rsa public key algorithm for host authentication, try to connect to it after removing the ssh-rsa algorithm from ssh(1)'s allowed list: ssh -oHostKeyAlgorithms=-ssh-rsa user@host If the host key verification fails and no other supported host key types are available, the server software on that host should be upgraded. A future release of OpenSSH will enable UpdateHostKeys by default to allow the client to automatically migrate to better algorithms. Users may consider enabling this option manually. [1] "SHA-1 is a Shambles: First Chosen-Prefix Collision on SHA-1 and Application to the PGP Web of Trust" Leurent, G and Peyrin, T (2020) https://eprint.iacr.org/2020/014.pdf Security ======== * ssh(1), sshd(8), ssh-keygen(1): this release removes the "ssh-rsa" (RSA/SHA1) algorithm from those accepted for certificate signatures (i.e. the client and server CASignatureAlgorithms option) and will use the rsa-sha2-512 signature algorithm by default when the ssh-keygen(1) CA signs new certificates. Certificates are at special risk to the aforementioned SHA1 collision vulnerability as an attacker has effectively unlimited time in which to craft a collision that yields them a valid certificate, far more than the relatively brief LoginGraceTime window that they have to forge a host key signature. The OpenSSH certificate format includes a CA-specified (typically random) nonce value near the start of the certificate that should make exploitation of chosen-prefix collisions in this context challenging, as the attacker does not have full control over the prefix that actually gets signed. Nonetheless, SHA1 is now a demonstrably broken algorithm and futher improvements in attacks are highly likely. OpenSSH releases prior to 7.2 do not support the newer RSA/SHA2 algorithms and will refuse to accept certificates signed by an OpenSSH 8.2+ CA using RSA keys unless the unsafe algorithm is explicitly selected during signing ("ssh-keygen -t ssh-rsa"). Older clients/servers may use another CA key type such as ssh-ed25519 (supported since OpenSSH 6.5) or one of the ecdsa-sha2-nistp256/384/521 types (supported since OpenSSH 5.7) instead if they cannot be upgraded. Potentially-incompatible changes ================================ This release includes a number of changes that may affect existing configurations: * ssh(1), sshd(8): the above removal of "ssh-rsa" from the accepted CASignatureAlgorithms list. * ssh(1), sshd(8): this release removes diffie-hellman-group14-sha1 from the default key exchange proposal for both the client and server. * ssh-keygen(1): the command-line options related to the generation and screening of safe prime numbers used by the diffie-hellman-group-exchange-* key exchange algorithms have changed. Most options have been folded under the -O flag. * sshd(8): the sshd listener process title visible to ps(1) has changed to include information about the number of connections that are currently attempting authentication and the limits configured by MaxStartups. * ssh-sk-helper(8): this is a new binary. It is used by the FIDO/U2F support to provide address-space isolation for token middleware libraries (including the internal one). It needs to be installed in the expected path, typically under /usr/libexec or similar. Changes since OpenSSH 8.1 ========================= This release contains some significant new features. FIDO/U2F Support ---------------- This release adds support for FIDO/U2F hardware authenticators to OpenSSH. U2F/FIDO are open standards for inexpensive two-factor authentication hardware that are widely used for website authentication. In OpenSSH FIDO devices are supported by new public key types "ecdsa-sk" and "ed25519-sk", along with corresponding certificate types. ssh-keygen(1) may be used to generate a FIDO token-backed key, after which they may be used much like any other key type supported by OpenSSH, so long as the hardware token is attached when the keys are used. FIDO tokens also generally require the user explicitly authorise operations by touching or tapping them. Generating a FIDO key requires the token be attached, and will usually require the user tap the token to confirm the operation: $ ssh-keygen -t ecdsa-sk -f ~/.ssh/id_ecdsa_sk Generating public/private ecdsa-sk key pair. You may need to touch your security key to authorize key generation. Enter file in which to save the key (/home/djm/.ssh/id_ecdsa_sk): Enter passphrase (empty for no passphrase): Enter same passphrase again: Your identification has been saved in /home/djm/.ssh/id_ecdsa_sk Your public key has been saved in /home/djm/.ssh/id_ecdsa_sk.pub This will yield a public and private key-pair. The private key file should be useless to an attacker who does not have access to the physical token. After generation, this key may be used like any other supported key in OpenSSH and may be listed in authorized_keys, added to ssh-agent(1), etc. The only additional stipulation is that the FIDO token that the key belongs to must be attached when the key is used. FIDO tokens are most commonly connected via USB but may be attached via other means such as Bluetooth or NFC. In OpenSSH, communication with the token is managed via a middleware library, specified by the SecurityKeyProvider directive in ssh/sshd_config(5) or the $SSH_SK_PROVIDER environment variable for ssh-keygen(1) and ssh-add(1). The API for this middleware is documented in the sk-api.h and PROTOCOL.u2f files in the source distribution. OpenSSH includes a middleware ("SecurityKeyProvider=internal") with support for USB tokens. It is automatically enabled in OpenBSD and may be enabled in portable OpenSSH via the configure flag --with-security-key-builtin. If the internal middleware is enabled then it is automatically used by default. This internal middleware requires that libfido2 (https://github.com/Yubico/libfido2) and its dependencies be installed. We recommend that packagers of portable OpenSSH enable the built-in middleware, as it provides the lowest-friction experience for users. Note: FIDO/U2F tokens are required to implement the ECDSA-P256 "ecdsa-sk" key type, but hardware support for Ed25519 "ed25519-sk" is less common. Similarly, not all hardware tokens support some of the optional features such as resident keys. The protocol-level changes to support FIDO/U2F keys in SSH are documented in the PROTOCOL.u2f file in the OpenSSH source distribution. There are a number of supporting changes to this feature: * ssh-keygen(1): add a "no-touch-required" option when generating FIDO-hosted keys, that disables their default behaviour of requiring a physical touch/tap on the token during authentication. Note: not all tokens support disabling the touch requirement. * sshd(8): add a sshd_config PubkeyAuthOptions directive that collects miscellaneous public key authentication-related options for sshd(8). At present it supports only a single option "no-touch-required". This causes sshd to skip its default check for FIDO/U2F keys that the signature was authorised by a touch or press event on the token hardware. * ssh(1), sshd(8), ssh-keygen(1): add a "no-touch-required" option for authorized_keys and a similar extension for certificates. This option disables the default requirement that FIDO key signatures attest that the user touched their key to authorize them, mirroring the similar PubkeyAuthOptions sshd_config option. * ssh-keygen(1): add support for the writing the FIDO attestation information that is returned when new keys are generated via the "-O write-attestation=/path" option. FIDO attestation certificates may be used to verify that a FIDO key is hosted in trusted hardware. OpenSSH does not currently make use of this information, beyond optionally writing it to disk. FIDO2 resident keys ------------------- FIDO/U2F OpenSSH keys consist of two parts: a "key handle" part stored in the private key file on disk, and a per-device private key that is unique to each FIDO/U2F token and that cannot be exported from the token hardware. These are combined by the hardware at authentication time to derive the real key that is used to sign authentication challenges. For tokens that are required to move between computers, it can be cumbersome to have to move the private key file first. To avoid this requirement, tokens implementing the newer FIDO2 standard support "resident keys", where it is possible to effectively retrieve the key handle part of the key from the hardware. OpenSSH supports this feature, allowing resident keys to be generated using the ssh-keygen(1) "-O resident" flag. This will produce a public/private key pair as usual, but it will be possible to retrieve the private key part from the token later. This may be done using "ssh-keygen -K", which will download all available resident keys from the tokens attached to the host and write public/private key files for them. It is also possible to download and add resident keys directly to ssh-agent(1) without writing files to the file-system using "ssh-add -K". Resident keys are indexed on the token by the application string and user ID. By default, OpenSSH uses an application string of "ssh:" and an empty user ID. If multiple resident keys on a single token are desired then it may be necessary to override one or both of these defaults using the ssh-keygen(1) "-O application=" or "-O user=" options. Note: OpenSSH will only download and use resident keys whose application string begins with "ssh:" Storing both parts of a key on a FIDO token increases the likelihood of an attacker being able to use a stolen token device. For this reason, tokens should enforce PIN authentication before allowing download of keys, and users should set a PIN on their tokens before creating any resident keys. Other New Features ------------------ * sshd(8): add an Include sshd_config keyword that allows including additional configuration files via glob(3) patterns. bz2468 * ssh(1)/sshd(8): make the LE (low effort) DSCP code point available via the IPQoS directive; bz2986, * ssh(1): when AddKeysToAgent=yes is set and the key contains no comment, add the key to the agent with the key's path as the comment. bz2564 * ssh-keygen(1), ssh-agent(1): expose PKCS#11 key labels and X.509 subjects as key comments, rather than simply listing the PKCS#11 provider library path. PR138 * ssh-keygen(1): allow PEM export of DSA and ECDSA keys; bz3091 * ssh(1), sshd(8): make zlib compile-time optional, available via the Makefile.inc ZLIB flag on OpenBSD or via the --with-zlib configure option for OpenSSH portable. * sshd(8): when clients get denied by MaxStartups, send a notification prior to the SSH2 protocol banner according to RFC4253 section 4.2. * ssh(1), ssh-agent(1): when invoking the $SSH_ASKPASS prompt program, pass a hint to the program to describe the type of desired prompt. The possible values are "confirm" (indicating that a yes/no confirmation dialog with no text entry should be shown), "none" (to indicate an informational message only), or blank for the original ssh-askpass behaviour of requesting a password/phrase. * ssh(1): allow forwarding a different agent socket to the path specified by $SSH_AUTH_SOCK, by extending the existing ForwardAgent option to accepting an explicit path or the name of an environment variable in addition to yes/no. * ssh-keygen(1): add a new signature operations "find-principals" to look up the principal associated with a signature from an allowed- signers file. * sshd(8): expose the number of currently-authenticating connections along with the MaxStartups limit in the process title visible to "ps". Bugfixes -------- * sshd(8): make ClientAliveCountMax=0 have sensible semantics: it will now disable connection killing entirely rather than the current behaviour of instantly killing the connection after the first liveness test regardless of success. bz2627 * sshd(8): clarify order of AllowUsers / DenyUsers vs AllowGroups / DenyGroups in the sshd(8) manual page. bz1690 * sshd(8): better describe HashKnownHosts in the manual page. bz2560 * sshd(8): clarify that that permitopen=/PermitOpen do no name or address translation in the manual page. bz3099 * sshd(8): allow the UpdateHostKeys feature to function when multiple known_hosts files are in use. When updating host keys, ssh will now search subsequent known_hosts files, but will add updated host keys to the first specified file only. bz2738 * All: replace all calls to signal(2) with a wrapper around sigaction(2). This wrapper blocks all other signals during the handler preventing races between handlers, and sets SA_RESTART which should reduce the potential for short read/write operations. * sftp(1): fix a race condition in the SIGCHILD handler that could turn in to a kill(-1); bz3084 * sshd(8): fix a case where valid (but extremely large) SSH channel IDs were being incorrectly rejected. bz3098 * ssh(1): when checking host key fingerprints as answers to new hostkey prompts, ignore whitespace surrounding the fingerprint itself. * All: wait for file descriptors to be readable or writeable during non-blocking connect, not just readable. Prevents a timeout when the server doesn't immediately send a banner (e.g. multiplexers like sslh) * sshd_config(5): document the sntrup4591761x25519-sha512@tinyssh.org key exchange algorithm. PR#151
2020-02-27 03:21:35 +03:00
Potentially-incompatible changes ================================ This release includes a number of changes that may affect existing configurations: * ssh(1): delete SSH protocol version 1 support, associated configuration options and documentation. * ssh(1)/sshd(8): remove support for the hmac-ripemd160 MAC. * ssh(1)/sshd(8): remove support for the arcfour, blowfish and CAST ciphers. * Refuse RSA keys <1024 bits in length and improve reporting for keys that do not meet this requirement. * ssh(1): do not offer CBC ciphers by default. Changes since OpenSSH 7.5 ========================= This is primarily a bugfix release. It also contains substantial internal refactoring. Security -------- * sftp-server(8): in read-only mode, sftp-server was incorrectly permitting creation of zero-length files. Reported by Michal Zalewski. New Features ------------ * ssh(1): add RemoteCommand option to specify a command in the ssh config file instead of giving it on the client's command line. This allows the configuration file to specify the command that will be executed on the remote host. * sshd(8): add ExposeAuthInfo option that enables writing details of the authentication methods used (including public keys where applicable) to a file that is exposed via a $SSH_USER_AUTH environment variable in the subsequent session. * ssh(1): add support for reverse dynamic forwarding. In this mode, ssh will act as a SOCKS4/5 proxy and forward connections to destinations requested by the remote SOCKS client. This mode is requested using extended syntax for the -R and RemoteForward options and, because it is implemented solely at the client, does not require the server be updated to be supported. * sshd(8): allow LogLevel directive in sshd_config Match blocks; bz#2717 * ssh-keygen(1): allow inclusion of arbitrary string or flag certificate extensions and critical options. * ssh-keygen(1): allow ssh-keygen to use a key held in ssh-agent as a CA when signing certificates. bz#2377 * ssh(1)/sshd(8): allow IPQoS=none in ssh/sshd to not set an explicit ToS/DSCP value and just use the operating system default. * ssh-add(1): added -q option to make ssh-add quiet on success. * ssh(1): expand the StrictHostKeyChecking option with two new settings. The first "accept-new" will automatically accept hitherto-unseen keys but will refuse connections for changed or invalid hostkeys. This is a safer subset of the current behaviour of StrictHostKeyChecking=no. The second setting "off", is a synonym for the current behaviour of StrictHostKeyChecking=no: accept new host keys, and continue connection for hosts with incorrect hostkeys. A future release will change the meaning of StrictHostKeyChecking=no to the behaviour of "accept-new". bz#2400 * ssh(1): add SyslogFacility option to ssh(1) matching the equivalent option in sshd(8). bz#2705 Bugfixes -------- * ssh(1): use HostKeyAlias if specified instead of hostname for matching host certificate principal names; bz#2728 * sftp(1): implement sorting for globbed ls; bz#2649 * ssh(1): add a user@host prefix to client's "Permission denied" messages, useful in particular when using "stacked" connections (e.g. ssh -J) where it's not clear which host is denying. bz#2720 * ssh(1): accept unknown EXT_INFO extension values that contain \0 characters. These are legal, but would previously cause fatal connection errors if received. * ssh(1)/sshd(8): repair compression statistics printed at connection exit * sftp(1): print '?' instead of incorrect link count (that the protocol doesn't provide) for remote listings. bz#2710 * ssh(1): return failure rather than fatal() for more cases during session multiplexing negotiations. Causes the session to fall back to a non-mux connection if they occur. bz#2707 * ssh(1): mention that the server may send debug messages to explain public key authentication problems under some circumstances; bz#2709 * Translate OpenSSL error codes to better report incorrect passphrase errors when loading private keys; bz#2699 * sshd(8): adjust compatibility patterns for WinSCP to correctly identify versions that implement only the legacy DH group exchange scheme. bz#2748 * ssh(1): print the "Killed by signal 1" message only at LogLevel verbose so that it is not shown at the default level; prevents it from appearing during ssh -J and equivalent ProxyCommand configs. bz#1906, bz#2744 * ssh-keygen(1): when generating all hostkeys (ssh-keygen -A), clobber existing keys if they exist but are zero length. zero-length keys could previously be made if ssh-keygen failed or was interrupted part way through generating them. bz#2561 * ssh(1): fix pledge(2) violation in the escape sequence "~&" used to place the current session in the background. * ssh-keyscan(1): avoid double-close() on file descriptors; bz#2734 * sshd(8): avoid reliance on shared use of pointers shared between monitor and child sshd processes. bz#2704 * sshd_config(8): document available AuthenticationMethods; bz#2453 * ssh(1): avoid truncation in some login prompts; bz#2768 * sshd(8): Fix various compilations failures, inc bz#2767 * ssh(1): make "--" before the hostname terminate argument processing after the hostname too. * ssh-keygen(1): switch from aes256-cbc to aes256-ctr for encrypting new-style private keys. Fixes problems related to private key handling for no-OpenSSL builds. bz#2754 * ssh(1): warn and do not attempt to use keys when the public and private halves do not match. bz#2737 * sftp(1): don't print verbose error message when ssh disconnects from under sftp. bz#2750 * sshd(8): fix keepalive scheduling problem: activity on a forwarded port from preventing the keepalive from being sent; bz#2756 * sshd(8): when started without root privileges, don't require the privilege separation user or path to exist. Makes running the regression tests easier without touching the filesystem. * Make integrity.sh regression tests more robust against timeouts. bz#2658 * ssh(1)/sshd(8): correctness fix for channels implementation: accept channel IDs greater than 0x7FFFFFFF. Portability ----------- * sshd(9): drop two more privileges in the Solaris sandbox: PRIV_DAX_ACCESS and PRIV_SYS_IB_INFO; bz#2723 * sshd(8): expose list of completed authentication methods to PAM via the SSH_AUTH_INFO_0 PAM environment variable. bz#2408 * ssh(1)/sshd(8): fix several problems in the tun/tap forwarding code, mostly to do with host/network byte order confusion. bz#2735 * Add --with-cflags-after and --with-ldflags-after configure flags to allow setting CFLAGS/LDFLAGS after configure has completed. These are useful for setting sanitiser/fuzzing options that may interfere with configure's operation. * sshd(8): avoid Linux seccomp violations on ppc64le over the socketcall syscall. * Fix use of ldns when using ldns-config; bz#2697 * configure: set cache variables when cross-compiling. The cross- compiling fallback message was saying it assumed the test passed, but it wasn't actually set the cache variables and this would cause later tests to fail. * Add clang libFuzzer harnesses for public key parsing and signature verification.
2017-10-07 22:36:11 +03:00
struct ssh;
struct fwd_perm_list;
OpenSSH 7.7 was released on 2018-04-02. It is available from the mirrors listed at http://www.openssh.com/ shortly. OpenSSH is a 100% complete SSH protocol 2.0 implementation and includes sftp client and server support. Once again, we would like to thank the OpenSSH community for their continued support of the project, especially those who contributed code or patches, reported bugs, tested snapshots or donated to the project. More information on donations may be found at: http://www.openssh.com/donations.html Potentially-incompatible changes ================================ This release includes a number of changes that may affect existing configurations: * ssh(1)/sshd(8): Drop compatibility support for some very old SSH implementations, including ssh.com <=2.* and OpenSSH <= 3.*. These versions were all released in or before 2001 and predate the final SSH RFCs. The support in question isn't necessary for RFC-compliant SSH implementations. Changes since OpenSSH 7.6 ========================= This is primarily a bugfix release. New Features ------------ * All: Add experimental support for PQC XMSS keys (Extended Hash- Based Signatures) based on the algorithm described in https://tools.ietf.org/html/draft-irtf-cfrg-xmss-hash-based-signatures-12 The XMSS signature code is experimental and not compiled in by default. * sshd(8): Add a "rdomain" criteria for the sshd_config Match keyword to allow conditional configuration that depends on which routing domain a connection was received on (currently supported on OpenBSD and Linux). * sshd_config(5): Add an optional rdomain qualifier to the ListenAddress directive to allow listening on different routing domains. This is supported only on OpenBSD and Linux at present. * sshd_config(5): Add RDomain directive to allow the authenticated session to be placed in an explicit routing domain. This is only supported on OpenBSD at present. * sshd(8): Add "expiry-time" option for authorized_keys files to allow for expiring keys. * ssh(1): Add a BindInterface option to allow binding the outgoing connection to an interface's address (basically a more usable BindAddress) * ssh(1): Expose device allocated for tun/tap forwarding via a new %T expansion for LocalCommand. This allows LocalCommand to be used to prepare the interface. * sshd(8): Expose the device allocated for tun/tap forwarding via a new SSH_TUNNEL environment variable. This allows automatic setup of the interface and surrounding network configuration automatically on the server. * ssh(1)/scp(1)/sftp(1): Add URI support to ssh, sftp and scp, e.g. ssh://user@host or sftp://user@host/path. Additional connection parameters described in draft-ietf-secsh-scp-sftp-ssh-uri-04 are not implemented since the ssh fingerprint format in the draft uses the deprecated MD5 hash with no way to specify the any other algorithm. * ssh-keygen(1): Allow certificate validity intervals that specify only a start or stop time (instead of both or neither). * sftp(1): Allow "cd" and "lcd" commands with no explicit path argument. lcd will change to the local user's home directory as usual. cd will change to the starting directory for session (because the protocol offers no way to obtain the remote user's home directory). bz#2760 * sshd(8): When doing a config test with sshd -T, only require the attributes that are actually used in Match criteria rather than (an incomplete list of) all criteria. Bugfixes -------- * ssh(1)/sshd(8): More strictly check signature types during key exchange against what was negotiated. Prevents downgrade of RSA signatures made with SHA-256/512 to SHA-1. * sshd(8): Fix support for client that advertise a protocol version of "1.99" (indicating that they are prepared to accept both SSHv1 and SSHv2). This was broken in OpenSSH 7.6 during the removal of SSHv1 support. bz#2810 * ssh(1): Warn when the agent returns a ssh-rsa (SHA1) signature when a rsa-sha2-256/512 signature was requested. This condition is possible when an old or non-OpenSSH agent is in use. bz#2799 * ssh-agent(1): Fix regression introduced in 7.6 that caused ssh-agent to fatally exit if presented an invalid signature request message. * sshd_config(5): Accept yes/no flag options case-insensitively, as has been the case in ssh_config(5) for a long time. bz#2664 * ssh(1): Improve error reporting for failures during connection. Under some circumstances misleading errors were being shown. bz#2814 * ssh-keyscan(1): Add -D option to allow printing of results directly in SSHFP format. bz#2821 * regress tests: fix PuTTY interop test broken in last release's SSHv1 removal. bz#2823 * ssh(1): Compatibility fix for some servers that erroneously drop the connection when the IUTF8 (RFC8160) option is sent. * scp(1): Disable RemoteCommand and RequestTTY in the ssh session started by scp (sftp was already doing this.) * ssh-keygen(1): Refuse to create a certificate with an unusable number of principals. * ssh-keygen(1): Fatally exit if ssh-keygen is unable to write all the public key during key generation. Previously it would silently ignore errors writing the comment and terminating newline. * ssh(1): Do not modify hostname arguments that are addresses by automatically forcing them to lower-case. Instead canonicalise them to resolve ambiguities (e.g. ::0001 => ::1) before they are matched against known_hosts. bz#2763 * ssh(1): Don't accept junk after "yes" or "no" responses to hostkey prompts. bz#2803 * sftp(1): Have sftp print a warning about shell cleanliness when decoding the first packet fails, which is usually caused by shells polluting stdout of non-interactive startups. bz#2800 * ssh(1)/sshd(8): Switch timers in packet code from using wall-clock time to monotonic time, allowing the packet layer to better function over a clock step and avoiding possible integer overflows during steps. * Numerous manual page fixes and improvements. Portability ----------- * sshd(8): Correctly detect MIPS ABI in use at configure time. Fixes sandbox violations on some environments. * sshd(8): Remove UNICOS support. The hardware and software are literal museum pieces and support in sshd is too intrusive to justify maintaining. * All: Build and link with "retpoline" flags when available to mitigate the "branch target injection" style (variant 2) of the Spectre branch-prediction vulnerability. * All: Add auto-generated dependency information to Makefile. * Numerous fixed to the RPM spec files. Checksums: ========== - SHA1 (openssh-7.7.tar.gz) = 24812e05fa233014c847c7775748316e7f8a836c - SHA256 (openssh-7.7.tar.gz) = T4ua1L/vgAYqwB0muRahvnm5ZUr3PLY9nPljaG8egvo= - SHA1 (openssh-7.7p1.tar.gz) = 446fe9ed171f289f0d62197dffdbfdaaf21c49f2 - SHA256 (openssh-7.7p1.tar.gz) = 1zvn5oTpnvzQJL4Vowv/y+QbASsvezyQhK7WIXdea48= Please note that the SHA256 signatures are base64 encoded and not hexadecimal (which is the default for most checksum tools). The PGP key used to sign the releases is available as RELEASE_KEY.asc from the mirror sites. Reporting Bugs: =============== - Please read http://www.openssh.com/report.html Security bugs should be reported directly to openssh@openssh.com
2018-04-06 21:56:05 +03:00
/*
* Used to store addresses from ListenAddr directives. These may be
* incomplete, as they may specify addresses that need to be merged
* with any ports requested by ListenPort.
*/
struct queued_listenaddr {
char *addr;
int port; /* <=0 if unspecified */
char *rdomain;
};
/* Resolved listen addresses, grouped by optional routing domain */
struct listenaddr {
char *rdomain;
struct addrinfo *addrs;
};
import 5.2 from ftp.openbsd.org
2009-06-08 02:19:00 +04:00
typedef struct {
u_int num_ports;
u_int ports_from_cmdline;
int ports[MAX_PORTS]; /* Port number to listen on. */
OpenSSH 7.7 was released on 2018-04-02. It is available from the mirrors listed at http://www.openssh.com/ shortly. OpenSSH is a 100% complete SSH protocol 2.0 implementation and includes sftp client and server support. Once again, we would like to thank the OpenSSH community for their continued support of the project, especially those who contributed code or patches, reported bugs, tested snapshots or donated to the project. More information on donations may be found at: http://www.openssh.com/donations.html Potentially-incompatible changes ================================ This release includes a number of changes that may affect existing configurations: * ssh(1)/sshd(8): Drop compatibility support for some very old SSH implementations, including ssh.com <=2.* and OpenSSH <= 3.*. These versions were all released in or before 2001 and predate the final SSH RFCs. The support in question isn't necessary for RFC-compliant SSH implementations. Changes since OpenSSH 7.6 ========================= This is primarily a bugfix release. New Features ------------ * All: Add experimental support for PQC XMSS keys (Extended Hash- Based Signatures) based on the algorithm described in https://tools.ietf.org/html/draft-irtf-cfrg-xmss-hash-based-signatures-12 The XMSS signature code is experimental and not compiled in by default. * sshd(8): Add a "rdomain" criteria for the sshd_config Match keyword to allow conditional configuration that depends on which routing domain a connection was received on (currently supported on OpenBSD and Linux). * sshd_config(5): Add an optional rdomain qualifier to the ListenAddress directive to allow listening on different routing domains. This is supported only on OpenBSD and Linux at present. * sshd_config(5): Add RDomain directive to allow the authenticated session to be placed in an explicit routing domain. This is only supported on OpenBSD at present. * sshd(8): Add "expiry-time" option for authorized_keys files to allow for expiring keys. * ssh(1): Add a BindInterface option to allow binding the outgoing connection to an interface's address (basically a more usable BindAddress) * ssh(1): Expose device allocated for tun/tap forwarding via a new %T expansion for LocalCommand. This allows LocalCommand to be used to prepare the interface. * sshd(8): Expose the device allocated for tun/tap forwarding via a new SSH_TUNNEL environment variable. This allows automatic setup of the interface and surrounding network configuration automatically on the server. * ssh(1)/scp(1)/sftp(1): Add URI support to ssh, sftp and scp, e.g. ssh://user@host or sftp://user@host/path. Additional connection parameters described in draft-ietf-secsh-scp-sftp-ssh-uri-04 are not implemented since the ssh fingerprint format in the draft uses the deprecated MD5 hash with no way to specify the any other algorithm. * ssh-keygen(1): Allow certificate validity intervals that specify only a start or stop time (instead of both or neither). * sftp(1): Allow "cd" and "lcd" commands with no explicit path argument. lcd will change to the local user's home directory as usual. cd will change to the starting directory for session (because the protocol offers no way to obtain the remote user's home directory). bz#2760 * sshd(8): When doing a config test with sshd -T, only require the attributes that are actually used in Match criteria rather than (an incomplete list of) all criteria. Bugfixes -------- * ssh(1)/sshd(8): More strictly check signature types during key exchange against what was negotiated. Prevents downgrade of RSA signatures made with SHA-256/512 to SHA-1. * sshd(8): Fix support for client that advertise a protocol version of "1.99" (indicating that they are prepared to accept both SSHv1 and SSHv2). This was broken in OpenSSH 7.6 during the removal of SSHv1 support. bz#2810 * ssh(1): Warn when the agent returns a ssh-rsa (SHA1) signature when a rsa-sha2-256/512 signature was requested. This condition is possible when an old or non-OpenSSH agent is in use. bz#2799 * ssh-agent(1): Fix regression introduced in 7.6 that caused ssh-agent to fatally exit if presented an invalid signature request message. * sshd_config(5): Accept yes/no flag options case-insensitively, as has been the case in ssh_config(5) for a long time. bz#2664 * ssh(1): Improve error reporting for failures during connection. Under some circumstances misleading errors were being shown. bz#2814 * ssh-keyscan(1): Add -D option to allow printing of results directly in SSHFP format. bz#2821 * regress tests: fix PuTTY interop test broken in last release's SSHv1 removal. bz#2823 * ssh(1): Compatibility fix for some servers that erroneously drop the connection when the IUTF8 (RFC8160) option is sent. * scp(1): Disable RemoteCommand and RequestTTY in the ssh session started by scp (sftp was already doing this.) * ssh-keygen(1): Refuse to create a certificate with an unusable number of principals. * ssh-keygen(1): Fatally exit if ssh-keygen is unable to write all the public key during key generation. Previously it would silently ignore errors writing the comment and terminating newline. * ssh(1): Do not modify hostname arguments that are addresses by automatically forcing them to lower-case. Instead canonicalise them to resolve ambiguities (e.g. ::0001 => ::1) before they are matched against known_hosts. bz#2763 * ssh(1): Don't accept junk after "yes" or "no" responses to hostkey prompts. bz#2803 * sftp(1): Have sftp print a warning about shell cleanliness when decoding the first packet fails, which is usually caused by shells polluting stdout of non-interactive startups. bz#2800 * ssh(1)/sshd(8): Switch timers in packet code from using wall-clock time to monotonic time, allowing the packet layer to better function over a clock step and avoiding possible integer overflows during steps. * Numerous manual page fixes and improvements. Portability ----------- * sshd(8): Correctly detect MIPS ABI in use at configure time. Fixes sandbox violations on some environments. * sshd(8): Remove UNICOS support. The hardware and software are literal museum pieces and support in sshd is too intrusive to justify maintaining. * All: Build and link with "retpoline" flags when available to mitigate the "branch target injection" style (variant 2) of the Spectre branch-prediction vulnerability. * All: Add auto-generated dependency information to Makefile. * Numerous fixed to the RPM spec files. Checksums: ========== - SHA1 (openssh-7.7.tar.gz) = 24812e05fa233014c847c7775748316e7f8a836c - SHA256 (openssh-7.7.tar.gz) = T4ua1L/vgAYqwB0muRahvnm5ZUr3PLY9nPljaG8egvo= - SHA1 (openssh-7.7p1.tar.gz) = 446fe9ed171f289f0d62197dffdbfdaaf21c49f2 - SHA256 (openssh-7.7p1.tar.gz) = 1zvn5oTpnvzQJL4Vowv/y+QbASsvezyQhK7WIXdea48= Please note that the SHA256 signatures are base64 encoded and not hexadecimal (which is the default for most checksum tools). The PGP key used to sign the releases is available as RELEASE_KEY.asc from the mirror sites. Reporting Bugs: =============== - Please read http://www.openssh.com/report.html Security bugs should be reported directly to openssh@openssh.com
2018-04-06 21:56:05 +03:00
struct queued_listenaddr *queued_listen_addrs;
Changes since OpenSSH 6.8 ========================= This is primarily a bugfix release. Security -------- * ssh(1): when forwarding X11 connections with ForwardX11Trusted=no, connections made after ForwardX11Timeout expired could be permitted and no longer subject to XSECURITY restrictions because of an ineffective timeout check in ssh(1) coupled with "fail open" behaviour in the X11 server when clients attempted connections with expired credentials. This problem was reported by Jann Horn. * ssh-agent(1): fix weakness of agent locking (ssh-add -x) to password guessing by implementing an increasing failure delay, storing a salted hash of the password rather than the password itself and using a timing-safe comparison function for verifying unlock attempts. This problem was reported by Ryan Castellucci. New Features ------------ * ssh(1), sshd(8): promote chacha20-poly1305@openssh.com to be the default cipher * sshd(8): support admin-specified arguments to AuthorizedKeysCommand; bz#2081 * sshd(8): add AuthorizedPrincipalsCommand that allows retrieving authorized principals information from a subprocess rather than a file. * ssh(1), ssh-add(1): support PKCS#11 devices with external PIN entry devices bz#2240 * sshd(8): allow GSSAPI host credential check to be relaxed for multihomed hosts via GSSAPIStrictAcceptorCheck option; bz#928 * ssh-keygen(1): support "ssh-keygen -lF hostname" to search known_hosts and print key hashes rather than full keys. * ssh-agent(1): add -D flag to leave ssh-agent in foreground without enabling debug mode; bz#2381 Bugfixes -------- * ssh(1), sshd(8): deprecate legacy SSH2_MSG_KEX_DH_GEX_REQUEST_OLD message and do not try to use it against some 3rd-party SSH implementations that use it (older PuTTY, WinSCP). * Many fixes for problems caused by compile-time deactivation of SSH1 support (including bz#2369) * ssh(1), sshd(8): cap DH-GEX group size at 4Kbits for Cisco implementations as some would fail when attempting to use group sizes >4K; bz#2209 * ssh(1): fix out-of-bound read in EscapeChar configuration option parsing; bz#2396 * sshd(8): fix application of PermitTunnel, LoginGraceTime, AuthenticationMethods and StreamLocalBindMask options in Match blocks * ssh(1), sshd(8): improve disconnection message on TCP reset; bz#2257 * ssh(1): remove failed remote forwards established by muliplexing from the list of active forwards; bz#2363 * sshd(8): make parsing of authorized_keys "environment=" options independent of PermitUserEnv being enabled; bz#2329 * sshd(8): fix post-auth crash with permitopen=none; bz#2355 * ssh(1), ssh-add(1), ssh-keygen(1): allow new-format private keys to be encrypted with AEAD ciphers; bz#2366 * ssh(1): allow ListenAddress, Port and AddressFamily configuration options to appear in any order; bz#86 * sshd(8): check for and reject missing arguments for VersionAddendum and ForceCommand; bz#2281 * ssh(1), sshd(8): don't treat unknown certificate extensions as fatal; bz#2387 * ssh-keygen(1): make stdout and stderr output consistent; bz#2325 * ssh(1): mention missing DISPLAY environment in debug log when X11 forwarding requested; bz#1682 * sshd(8): correctly record login when UseLogin is set; bz#378 * sshd(8): Add some missing options to sshd -T output and fix output of VersionAddendum and HostCertificate. bz#2346 * Document and improve consistency of options that accept a "none" argument" TrustedUserCAKeys, RevokedKeys (bz#2382), AuthorizedPrincipalsFile (bz#2288) * ssh(1): include remote username in debug output; bz#2368 * sshd(8): avoid compatibility problem with some versions of Tera Term, which would crash when they received the hostkeys notification message (hostkeys-00@openssh.com) * sshd(8): mention ssh-keygen -E as useful when comparing legacy MD5 host key fingerprints; bz#2332 * ssh(1): clarify pseudo-terminal request behaviour and use make manual language consistent; bz#1716 * ssh(1): document that the TERM environment variable is not subject to SendEnv and AcceptEnv; bz#2386
2015-07-03 03:54:41 +03:00
u_int num_queued_listens;
OpenSSH 7.7 was released on 2018-04-02. It is available from the mirrors listed at http://www.openssh.com/ shortly. OpenSSH is a 100% complete SSH protocol 2.0 implementation and includes sftp client and server support. Once again, we would like to thank the OpenSSH community for their continued support of the project, especially those who contributed code or patches, reported bugs, tested snapshots or donated to the project. More information on donations may be found at: http://www.openssh.com/donations.html Potentially-incompatible changes ================================ This release includes a number of changes that may affect existing configurations: * ssh(1)/sshd(8): Drop compatibility support for some very old SSH implementations, including ssh.com <=2.* and OpenSSH <= 3.*. These versions were all released in or before 2001 and predate the final SSH RFCs. The support in question isn't necessary for RFC-compliant SSH implementations. Changes since OpenSSH 7.6 ========================= This is primarily a bugfix release. New Features ------------ * All: Add experimental support for PQC XMSS keys (Extended Hash- Based Signatures) based on the algorithm described in https://tools.ietf.org/html/draft-irtf-cfrg-xmss-hash-based-signatures-12 The XMSS signature code is experimental and not compiled in by default. * sshd(8): Add a "rdomain" criteria for the sshd_config Match keyword to allow conditional configuration that depends on which routing domain a connection was received on (currently supported on OpenBSD and Linux). * sshd_config(5): Add an optional rdomain qualifier to the ListenAddress directive to allow listening on different routing domains. This is supported only on OpenBSD and Linux at present. * sshd_config(5): Add RDomain directive to allow the authenticated session to be placed in an explicit routing domain. This is only supported on OpenBSD at present. * sshd(8): Add "expiry-time" option for authorized_keys files to allow for expiring keys. * ssh(1): Add a BindInterface option to allow binding the outgoing connection to an interface's address (basically a more usable BindAddress) * ssh(1): Expose device allocated for tun/tap forwarding via a new %T expansion for LocalCommand. This allows LocalCommand to be used to prepare the interface. * sshd(8): Expose the device allocated for tun/tap forwarding via a new SSH_TUNNEL environment variable. This allows automatic setup of the interface and surrounding network configuration automatically on the server. * ssh(1)/scp(1)/sftp(1): Add URI support to ssh, sftp and scp, e.g. ssh://user@host or sftp://user@host/path. Additional connection parameters described in draft-ietf-secsh-scp-sftp-ssh-uri-04 are not implemented since the ssh fingerprint format in the draft uses the deprecated MD5 hash with no way to specify the any other algorithm. * ssh-keygen(1): Allow certificate validity intervals that specify only a start or stop time (instead of both or neither). * sftp(1): Allow "cd" and "lcd" commands with no explicit path argument. lcd will change to the local user's home directory as usual. cd will change to the starting directory for session (because the protocol offers no way to obtain the remote user's home directory). bz#2760 * sshd(8): When doing a config test with sshd -T, only require the attributes that are actually used in Match criteria rather than (an incomplete list of) all criteria. Bugfixes -------- * ssh(1)/sshd(8): More strictly check signature types during key exchange against what was negotiated. Prevents downgrade of RSA signatures made with SHA-256/512 to SHA-1. * sshd(8): Fix support for client that advertise a protocol version of "1.99" (indicating that they are prepared to accept both SSHv1 and SSHv2). This was broken in OpenSSH 7.6 during the removal of SSHv1 support. bz#2810 * ssh(1): Warn when the agent returns a ssh-rsa (SHA1) signature when a rsa-sha2-256/512 signature was requested. This condition is possible when an old or non-OpenSSH agent is in use. bz#2799 * ssh-agent(1): Fix regression introduced in 7.6 that caused ssh-agent to fatally exit if presented an invalid signature request message. * sshd_config(5): Accept yes/no flag options case-insensitively, as has been the case in ssh_config(5) for a long time. bz#2664 * ssh(1): Improve error reporting for failures during connection. Under some circumstances misleading errors were being shown. bz#2814 * ssh-keyscan(1): Add -D option to allow printing of results directly in SSHFP format. bz#2821 * regress tests: fix PuTTY interop test broken in last release's SSHv1 removal. bz#2823 * ssh(1): Compatibility fix for some servers that erroneously drop the connection when the IUTF8 (RFC8160) option is sent. * scp(1): Disable RemoteCommand and RequestTTY in the ssh session started by scp (sftp was already doing this.) * ssh-keygen(1): Refuse to create a certificate with an unusable number of principals. * ssh-keygen(1): Fatally exit if ssh-keygen is unable to write all the public key during key generation. Previously it would silently ignore errors writing the comment and terminating newline. * ssh(1): Do not modify hostname arguments that are addresses by automatically forcing them to lower-case. Instead canonicalise them to resolve ambiguities (e.g. ::0001 => ::1) before they are matched against known_hosts. bz#2763 * ssh(1): Don't accept junk after "yes" or "no" responses to hostkey prompts. bz#2803 * sftp(1): Have sftp print a warning about shell cleanliness when decoding the first packet fails, which is usually caused by shells polluting stdout of non-interactive startups. bz#2800 * ssh(1)/sshd(8): Switch timers in packet code from using wall-clock time to monotonic time, allowing the packet layer to better function over a clock step and avoiding possible integer overflows during steps. * Numerous manual page fixes and improvements. Portability ----------- * sshd(8): Correctly detect MIPS ABI in use at configure time. Fixes sandbox violations on some environments. * sshd(8): Remove UNICOS support. The hardware and software are literal museum pieces and support in sshd is too intrusive to justify maintaining. * All: Build and link with "retpoline" flags when available to mitigate the "branch target injection" style (variant 2) of the Spectre branch-prediction vulnerability. * All: Add auto-generated dependency information to Makefile. * Numerous fixed to the RPM spec files. Checksums: ========== - SHA1 (openssh-7.7.tar.gz) = 24812e05fa233014c847c7775748316e7f8a836c - SHA256 (openssh-7.7.tar.gz) = T4ua1L/vgAYqwB0muRahvnm5ZUr3PLY9nPljaG8egvo= - SHA1 (openssh-7.7p1.tar.gz) = 446fe9ed171f289f0d62197dffdbfdaaf21c49f2 - SHA256 (openssh-7.7p1.tar.gz) = 1zvn5oTpnvzQJL4Vowv/y+QbASsvezyQhK7WIXdea48= Please note that the SHA256 signatures are base64 encoded and not hexadecimal (which is the default for most checksum tools). The PGP key used to sign the releases is available as RELEASE_KEY.asc from the mirror sites. Reporting Bugs: =============== - Please read http://www.openssh.com/report.html Security bugs should be reported directly to openssh@openssh.com
2018-04-06 21:56:05 +03:00
struct listenaddr *listen_addrs;
u_int num_listen_addrs;
int address_family; /* Address family used by the server. */
char *routing_domain; /* Bind session to routing domain */
char **host_key_files; /* Files containing host keys. */
Import 8.0: Security ======== This release contains mitigation for a weakness in the scp(1) tool and protocol (CVE-2019-6111): when copying files from a remote system to a local directory, scp(1) did not verify that the filenames that the server sent matched those requested by the client. This could allow a hostile server to create or clobber unexpected local files with attacker-controlled content. This release adds client-side checking that the filenames sent from the server match the command-line request, The scp protocol is outdated, inflexible and not readily fixed. We recommend the use of more modern protocols like sftp and rsync for file transfer instead. Potentially-incompatible changes ================================ This release includes a number of changes that may affect existing configurations: * scp(1): Relating to the above changes to scp(1); the scp protocol relies on the remote shell for wildcard expansion, so there is no infallible way for the client's wildcard matching to perfectly reflect the server's. If there is a difference between client and server wildcard expansion, the client may refuse files from the server. For this reason, we have provided a new "-T" flag to scp that disables these client-side checks at the risk of reintroducing the attack described above. * sshd(8): Remove support for obsolete "host/port" syntax. Slash- separated host/port was added in 2001 as an alternative to host:port syntax for the benefit of IPv6 users. These days there are establised standards for this like [::1]:22 and the slash syntax is easily mistaken for CIDR notation, which OpenSSH supports for some things. Remove the slash notation from ListenAddress and PermitOpen; bz#2335 Changes since OpenSSH 7.9 ========================= This release is focused on new features and internal refactoring. New Features ------------ * ssh(1), ssh-agent(1), ssh-add(1): Add support for ECDSA keys in PKCS#11 tokens. * ssh(1), sshd(8): Add experimental quantum-computing resistant key exchange method, based on a combination of Streamlined NTRU Prime 4591^761 and X25519. * ssh-keygen(1): Increase the default RSA key size to 3072 bits, following NIST Special Publication 800-57's guidance for a 128-bit equivalent symmetric security level. * ssh(1): Allow "PKCS11Provider=none" to override later instances of the PKCS11Provider directive in ssh_config; bz#2974 * sshd(8): Add a log message for situations where a connection is dropped for attempting to run a command but a sshd_config ForceCommand=internal-sftp restriction is in effect; bz#2960 * ssh(1): When prompting whether to record a new host key, accept the key fingerprint as a synonym for "yes". This allows the user to paste a fingerprint obtained out of band at the prompt and have the client do the comparison for you. * ssh-keygen(1): When signing multiple certificates on a single command-line invocation, allow automatically incrementing the certificate serial number. * scp(1), sftp(1): Accept -J option as an alias to ProxyJump on the scp and sftp command-lines. * ssh-agent(1), ssh-pkcs11-helper(8), ssh-add(1): Accept "-v" command-line flags to increase the verbosity of output; pass verbose flags though to subprocesses, such as ssh-pkcs11-helper started from ssh-agent. * ssh-add(1): Add a "-T" option to allowing testing whether keys in an agent are usable by performing a signature and a verification. * sftp-server(8): Add a "lsetstat@openssh.com" protocol extension that replicates the functionality of the existing SSH2_FXP_SETSTAT operation but does not follow symlinks. bz#2067 * sftp(1): Add "-h" flag to chown/chgrp/chmod commands to request they do not follow symlinks. * sshd(8): Expose $SSH_CONNECTION in the PAM environment. This makes the connection 4-tuple available to PAM modules that wish to use it in decision-making. bz#2741 * sshd(8): Add a ssh_config "Match final" predicate Matches in same pass as "Match canonical" but doesn't require hostname canonicalisation be enabled. bz#2906 * sftp(1): Support a prefix of '@' to suppress echo of sftp batch commands; bz#2926 * ssh-keygen(1): When printing certificate contents using "ssh-keygen -Lf /path/certificate", include the algorithm that the CA used to sign the cert. Bugfixes -------- * sshd(8): Fix authentication failures when sshd_config contains "AuthenticationMethods any" inside a Match block that overrides a more restrictive default. * sshd(8): Avoid sending duplicate keepalives when ClientAliveCount is enabled. * sshd(8): Fix two race conditions related to SIGHUP daemon restart. Remnant file descriptors in recently-forked child processes could block the parent sshd's attempt to listen(2) to the configured addresses. Also, the restarting parent sshd could exit before any child processes that were awaiting their re-execution state had completed reading it, leaving them in a fallback path. * ssh(1): Fix stdout potentially being redirected to /dev/null when ProxyCommand=- was in use. * sshd(8): Avoid sending SIGPIPE to child processes if they attempt to write to stderr after their parent processes have exited; bz#2071 * ssh(1): Fix bad interaction between the ssh_config ConnectTimeout and ConnectionAttempts directives - connection attempts after the first were ignoring the requested timeout; bz#2918 * ssh-keyscan(1): Return a non-zero exit status if no keys were found; bz#2903 * scp(1): Sanitize scp filenames to allow UTF-8 characters without terminal control sequences; bz#2434 * sshd(8): Fix confusion between ClientAliveInterval and time-based RekeyLimit that could cause connections to be incorrectly closed. bz#2757 * ssh(1), ssh-add(1): Correct some bugs in PKCS#11 token PIN handling at initial token login. The attempt to read the PIN could be skipped in some cases, particularly on devices with integrated PIN readers. This would lead to an inability to retrieve keys from these tokens. bz#2652 * ssh(1), ssh-add(1): Support keys on PKCS#11 tokens that set the CKA_ALWAYS_AUTHENTICATE flag by requring a fresh login after the C_SignInit operation. bz#2638 * ssh(1): Improve documentation for ProxyJump/-J, clarifying that local configuration does not apply to jump hosts. * ssh-keygen(1): Clarify manual - ssh-keygen -e only writes public keys, not private. * ssh(1), sshd(8): be more strict in processing protocol banners, allowing \r characters only immediately before \n. * Various: fix a number of memory leaks, including bz#2942 and bz#2938 * scp(1), sftp(1): fix calculation of initial bandwidth limits. Account for bytes written before the timer starts and adjust the schedule on which recalculations are performed. Avoids an initial burst of traffic and yields more accurate bandwidth limits; bz#2927 * sshd(8): Only consider the ext-info-c extension during the initial key eschange. It shouldn't be sent in subsequent ones, but if it is present we should ignore it. This prevents sshd from sending a SSH_MSG_EXT_INFO for REKEX for buggy these clients. bz#2929 * ssh-keygen(1): Clarify manual that ssh-keygen -F (find host in authorized_keys) and -R (remove host from authorized_keys) options may accept either a bare hostname or a [hostname]:port combo. bz#2935 * ssh(1): Don't attempt to connect to empty SSH_AUTH_SOCK; bz#2936 * sshd(8): Silence error messages when sshd fails to load some of the default host keys. Failure to load an explicitly-configured hostkey is still an error, and failure to load any host key is still fatal. pr/103 * ssh(1): Redirect stderr of ProxyCommands to /dev/null when ssh is started with ControlPersist; prevents random ProxyCommand output from interfering with session output. * ssh(1): The ssh client was keeping a redundant ssh-agent socket (leftover from authentication) around for the life of the connection; bz#2912 * sshd(8): Fix bug in HostbasedAcceptedKeyTypes and PubkeyAcceptedKeyTypes options. If only RSA-SHA2 siganture types were specified, then authentication would always fail for RSA keys as the monitor checks only the base key (not the signature algorithm) type against *AcceptedKeyTypes. bz#2746 * ssh(1): Request correct signature types from ssh-agent when certificate keys and RSA-SHA2 signatures are in use. Portability ----------- * sshd(8): On Cygwin, run as SYSTEM where possible, using S4U for token creation if it supports MsV1_0 S4U Logon. * sshd(8): On Cygwin, use custom user/group matching code that respects the OS' behaviour of case-insensitive matching. * sshd(8): Don't set $MAIL if UsePAM=yes as PAM typically specifies the user environment if it's enabled; bz#2937 * sshd(8) Cygwin: Change service name to cygsshd to avoid collision with Microsoft's OpenSSH port. * Allow building against OpenSSL -dev (3.x) * Fix a number of build problems against version configurations and versions of OpenSSL. Including bz#2931 and bz#2921 * Improve warnings in cygwin service setup. bz#2922 * Remove hardcoded service name in cygwin setup. bz#2922
2019-04-20 20:13:53 +03:00
int *host_key_file_userprovided; /* Key was specified by user. */
OpenSSH 7.7 was released on 2018-04-02. It is available from the mirrors listed at http://www.openssh.com/ shortly. OpenSSH is a 100% complete SSH protocol 2.0 implementation and includes sftp client and server support. Once again, we would like to thank the OpenSSH community for their continued support of the project, especially those who contributed code or patches, reported bugs, tested snapshots or donated to the project. More information on donations may be found at: http://www.openssh.com/donations.html Potentially-incompatible changes ================================ This release includes a number of changes that may affect existing configurations: * ssh(1)/sshd(8): Drop compatibility support for some very old SSH implementations, including ssh.com <=2.* and OpenSSH <= 3.*. These versions were all released in or before 2001 and predate the final SSH RFCs. The support in question isn't necessary for RFC-compliant SSH implementations. Changes since OpenSSH 7.6 ========================= This is primarily a bugfix release. New Features ------------ * All: Add experimental support for PQC XMSS keys (Extended Hash- Based Signatures) based on the algorithm described in https://tools.ietf.org/html/draft-irtf-cfrg-xmss-hash-based-signatures-12 The XMSS signature code is experimental and not compiled in by default. * sshd(8): Add a "rdomain" criteria for the sshd_config Match keyword to allow conditional configuration that depends on which routing domain a connection was received on (currently supported on OpenBSD and Linux). * sshd_config(5): Add an optional rdomain qualifier to the ListenAddress directive to allow listening on different routing domains. This is supported only on OpenBSD and Linux at present. * sshd_config(5): Add RDomain directive to allow the authenticated session to be placed in an explicit routing domain. This is only supported on OpenBSD at present. * sshd(8): Add "expiry-time" option for authorized_keys files to allow for expiring keys. * ssh(1): Add a BindInterface option to allow binding the outgoing connection to an interface's address (basically a more usable BindAddress) * ssh(1): Expose device allocated for tun/tap forwarding via a new %T expansion for LocalCommand. This allows LocalCommand to be used to prepare the interface. * sshd(8): Expose the device allocated for tun/tap forwarding via a new SSH_TUNNEL environment variable. This allows automatic setup of the interface and surrounding network configuration automatically on the server. * ssh(1)/scp(1)/sftp(1): Add URI support to ssh, sftp and scp, e.g. ssh://user@host or sftp://user@host/path. Additional connection parameters described in draft-ietf-secsh-scp-sftp-ssh-uri-04 are not implemented since the ssh fingerprint format in the draft uses the deprecated MD5 hash with no way to specify the any other algorithm. * ssh-keygen(1): Allow certificate validity intervals that specify only a start or stop time (instead of both or neither). * sftp(1): Allow "cd" and "lcd" commands with no explicit path argument. lcd will change to the local user's home directory as usual. cd will change to the starting directory for session (because the protocol offers no way to obtain the remote user's home directory). bz#2760 * sshd(8): When doing a config test with sshd -T, only require the attributes that are actually used in Match criteria rather than (an incomplete list of) all criteria. Bugfixes -------- * ssh(1)/sshd(8): More strictly check signature types during key exchange against what was negotiated. Prevents downgrade of RSA signatures made with SHA-256/512 to SHA-1. * sshd(8): Fix support for client that advertise a protocol version of "1.99" (indicating that they are prepared to accept both SSHv1 and SSHv2). This was broken in OpenSSH 7.6 during the removal of SSHv1 support. bz#2810 * ssh(1): Warn when the agent returns a ssh-rsa (SHA1) signature when a rsa-sha2-256/512 signature was requested. This condition is possible when an old or non-OpenSSH agent is in use. bz#2799 * ssh-agent(1): Fix regression introduced in 7.6 that caused ssh-agent to fatally exit if presented an invalid signature request message. * sshd_config(5): Accept yes/no flag options case-insensitively, as has been the case in ssh_config(5) for a long time. bz#2664 * ssh(1): Improve error reporting for failures during connection. Under some circumstances misleading errors were being shown. bz#2814 * ssh-keyscan(1): Add -D option to allow printing of results directly in SSHFP format. bz#2821 * regress tests: fix PuTTY interop test broken in last release's SSHv1 removal. bz#2823 * ssh(1): Compatibility fix for some servers that erroneously drop the connection when the IUTF8 (RFC8160) option is sent. * scp(1): Disable RemoteCommand and RequestTTY in the ssh session started by scp (sftp was already doing this.) * ssh-keygen(1): Refuse to create a certificate with an unusable number of principals. * ssh-keygen(1): Fatally exit if ssh-keygen is unable to write all the public key during key generation. Previously it would silently ignore errors writing the comment and terminating newline. * ssh(1): Do not modify hostname arguments that are addresses by automatically forcing them to lower-case. Instead canonicalise them to resolve ambiguities (e.g. ::0001 => ::1) before they are matched against known_hosts. bz#2763 * ssh(1): Don't accept junk after "yes" or "no" responses to hostkey prompts. bz#2803 * sftp(1): Have sftp print a warning about shell cleanliness when decoding the first packet fails, which is usually caused by shells polluting stdout of non-interactive startups. bz#2800 * ssh(1)/sshd(8): Switch timers in packet code from using wall-clock time to monotonic time, allowing the packet layer to better function over a clock step and avoiding possible integer overflows during steps. * Numerous manual page fixes and improvements. Portability ----------- * sshd(8): Correctly detect MIPS ABI in use at configure time. Fixes sandbox violations on some environments. * sshd(8): Remove UNICOS support. The hardware and software are literal museum pieces and support in sshd is too intrusive to justify maintaining. * All: Build and link with "retpoline" flags when available to mitigate the "branch target injection" style (variant 2) of the Spectre branch-prediction vulnerability. * All: Add auto-generated dependency information to Makefile. * Numerous fixed to the RPM spec files. Checksums: ========== - SHA1 (openssh-7.7.tar.gz) = 24812e05fa233014c847c7775748316e7f8a836c - SHA256 (openssh-7.7.tar.gz) = T4ua1L/vgAYqwB0muRahvnm5ZUr3PLY9nPljaG8egvo= - SHA1 (openssh-7.7p1.tar.gz) = 446fe9ed171f289f0d62197dffdbfdaaf21c49f2 - SHA256 (openssh-7.7p1.tar.gz) = 1zvn5oTpnvzQJL4Vowv/y+QbASsvezyQhK7WIXdea48= Please note that the SHA256 signatures are base64 encoded and not hexadecimal (which is the default for most checksum tools). The PGP key used to sign the releases is available as RELEASE_KEY.asc from the mirror sites. Reporting Bugs: =============== - Please read http://www.openssh.com/report.html Security bugs should be reported directly to openssh@openssh.com
2018-04-06 21:56:05 +03:00
u_int num_host_key_files; /* Number of files for host keys. */
char **host_cert_files; /* Files containing host certs. */
u_int num_host_cert_files; /* Number of files for host certs. */
char *host_key_agent; /* ssh-agent socket for host keys. */
char *pid_file; /* Where to put our pid */
Import OpenSSH-8.6: Future deprecation notice ========================= It is now possible[1] to perform chosen-prefix attacks against the SHA-1 algorithm for less than USD$50K. In the SSH protocol, the "ssh-rsa" signature scheme uses the SHA-1 hash algorithm in conjunction with the RSA public key algorithm. OpenSSH will disable this signature scheme by default in the near future. Note that the deactivation of "ssh-rsa" signatures does not necessarily require cessation of use for RSA keys. In the SSH protocol, keys may be capable of signing using multiple algorithms. In particular, "ssh-rsa" keys are capable of signing using "rsa-sha2-256" (RSA/SHA256), "rsa-sha2-512" (RSA/SHA512) and "ssh-rsa" (RSA/SHA1). Only the last of these is being turned off by default. This algorithm is unfortunately still used widely despite the existence of better alternatives, being the only remaining public key signature algorithm specified by the original SSH RFCs that is still enabled by default. The better alternatives include: * The RFC8332 RSA SHA-2 signature algorithms rsa-sha2-256/512. These algorithms have the advantage of using the same key type as "ssh-rsa" but use the safe SHA-2 hash algorithms. These have been supported since OpenSSH 7.2 and are already used by default if the client and server support them. * The RFC8709 ssh-ed25519 signature algorithm. It has been supported in OpenSSH since release 6.5. * The RFC5656 ECDSA algorithms: ecdsa-sha2-nistp256/384/521. These have been supported by OpenSSH since release 5.7. To check whether a server is using the weak ssh-rsa public key algorithm, for host authentication, try to connect to it after removing the ssh-rsa algorithm from ssh(1)'s allowed list: ssh -oHostKeyAlgorithms=-ssh-rsa user@host If the host key verification fails and no other supported host key types are available, the server software on that host should be upgraded. OpenSSH recently enabled the UpdateHostKeys option by default to assist the client by automatically migrating to better algorithms. [1] "SHA-1 is a Shambles: First Chosen-Prefix Collision on SHA-1 and Application to the PGP Web of Trust" Leurent, G and Peyrin, T (2020) https://eprint.iacr.org/2020/014.pdf Security ======== * sshd(8): OpenSSH 8.5 introduced the LogVerbose keyword. When this option was enabled with a set of patterns that activated logging in code that runs in the low-privilege sandboxed sshd process, the log messages were constructed in such a way that printf(3) format strings could effectively be specified the low-privilege code. An attacker who had sucessfully exploited the low-privilege process could use this to escape OpenSSH's sandboxing and attack the high-privilege process. Exploitation of this weakness is highly unlikely in practice as the LogVerbose option is not enabled by default and is typically only used for debugging. No vulnerabilities in the low-privilege process are currently known to exist. Thanks to Ilja Van Sprundel for reporting this bug. Changes since OpenSSH 8.5 ========================= This release contains mostly bug fixes. New features ------------ * sftp-server(8): add a new limits@openssh.com protocol extension that allows a client to discover various server limits, including maximum packet size and maximum read/write length. * sftp(1): use the new limits@openssh.com extension (when available) to select better transfer lengths in the client. * sshd(8): Add ModuliFile keyword to sshd_config to specify the location of the "moduli" file containing the groups for DH-GEX. * unit tests: Add a TEST_SSH_ELAPSED_TIMES environment variable to enable printing of the elapsed time in seconds of each test. Bugfixes -------- * ssh_config(5), sshd_config(5): sync CASignatureAlgorithms lists in manual pages with the current default. GHPR#174 * ssh(1): ensure that pkcs11_del_provider() is called before exit. GHPR#234 * ssh(1), sshd(8): fix problems in string->argv conversion. Multiple backslashes were not being dequoted correctly and quoted space in the middle of a string was being incorrectly split. GHPR#223 * ssh(1): return non-zero exit status when killed by signal; bz#3281 * sftp-server(8): increase maximum SSH2_FXP_READ to match the maximum packet size. Also handle zero-length reads that are not explicitly banned by the spec. Portability ----------- * sshd(8): don't mistakenly exit on transient read errors on the network socket (e.g. EINTR, EAGAIN); bz3297 * Create a dedicated contrib/gnome-ssk-askpass3.c source instead of building it from the same file as used for GNOME2. Use the GNOME3 gdk_seat_grab() to manage keyboard/mouse/server grabs for better compatibility with Wayland. * Fix portability build errors bz3293 bz3292 bz3291 bz3278 * sshd(8): soft-disallow the fstatat64 syscall in the Linux seccomp-bpf sandbox. bz3276 * unit tests: enable autoopt and misc unit tests that were previously skipped
2021-04-19 17:38:27 +03:00
char *moduli_file; /* moduli file for DH-GEX */
import 5.2 from ftp.openbsd.org
2009-06-08 02:19:00 +04:00
int login_grace_time; /* Disconnect if no auth in this time
* (sec). */
int permit_root_login; /* PERMIT_*, see above */
int ignore_rhosts; /* Ignore .rhosts and .shosts. */
int ignore_user_known_hosts; /* Ignore ~/.ssh/known_hosts
* for RhostsRsaAuth */
int print_motd; /* If true, print /etc/motd. */
int print_lastlog; /* If true, print lastlog */
int x11_forwarding; /* If true, permit inet (spoofing) X11 fwd. */
int x11_display_offset; /* What DISPLAY number to start
* searching at */
int x11_use_localhost; /* If true, use localhost for fake X11 server. */
char *xauth_location; /* Location of xauth program */
Changes since OpenSSH 6.6 ========================= Potentially-incompatible changes * sshd(8): The default set of ciphers and MACs has been altered to remove unsafe algorithms. In particular, CBC ciphers and arcfour* are disabled by default. The full set of algorithms remains available if configured explicitly via the Ciphers and MACs sshd_config options. * sshd(8): Support for tcpwrappers/libwrap has been removed. * OpenSSH 6.5 and 6.6 have a bug that causes ~0.2% of connections using the curve25519-sha256@libssh.org KEX exchange method to fail when connecting with something that implements the specification correctly. OpenSSH 6.7 disables this KEX method when speaking to one of the affected versions. New Features * Major internal refactoring to begin to make part of OpenSSH usable as a library. So far the wire parsing, key handling and KRL code has been refactored. Please note that we do not consider the API stable yet, nor do we offer the library in separable form. * ssh(1), sshd(8): Add support for Unix domain socket forwarding. A remote TCP port may be forwarded to a local Unix domain socket and vice versa or both ends may be a Unix domain socket. * ssh(1), ssh-keygen(1): Add support for SSHFP DNS records for ED25519 key types. * sftp(1): Allow resumption of interrupted uploads. * ssh(1): When rekeying, skip file/DNS lookups of the hostkey if it is the same as the one sent during initial key exchange; bz#2154 * sshd(8): Allow explicit ::1 and 127.0.0.1 forwarding bind addresses when GatewayPorts=no; allows client to choose address family; bz#2222 * sshd(8): Add a sshd_config PermitUserRC option to control whether ~/.ssh/rc is executed, mirroring the no-user-rc authorized_keys option; bz#2160 * ssh(1): Add a %C escape sequence for LocalCommand and ControlPath that expands to a unique identifer based on a hash of the tuple of (local host, remote user, hostname, port). Helps avoid exceeding miserly pathname limits for Unix domain sockets in multiplexing control paths; bz#2220 * sshd(8): Make the "Too many authentication failures" message include the user, source address, port and protocol in a format similar to the authentication success / failure messages; bz#2199 * Added unit and fuzz tests for refactored code. These are run automatically in portable OpenSSH via the "make tests" target. Bugfixes * sshd(8): Fix remote forwarding with the same listen port but different listen address. * ssh(1): Fix inverted test that caused PKCS#11 keys that were explicitly listed in ssh_config or on the commandline not to be preferred. * ssh-keygen(1): Fix bug in KRL generation: multiple consecutive revoked certificate serial number ranges could be serialised to an invalid format. Readers of a broken KRL caused by this bug will fail closed, so no should-have-been-revoked key will be accepted. * ssh(1): Reflect stdio-forward ("ssh -W host:port ...") failures in exit status. Previously we were always returning 0; bz#2255 * ssh(1), ssh-keygen(1): Make Ed25519 keys' title fit properly in the randomart border; bz#2247 * ssh-agent(1): Only cleanup agent socket in the main agent process and not in any subprocesses it may have started (e.g. forked askpass). Fixes agent sockets being zapped when askpass processes fatal(); bz#2236 * ssh-add(1): Make stdout line-buffered; saves partial output getting lost when ssh-add fatal()s part-way through (e.g. when listing keys from an agent that supports key types that ssh-add doesn't); bz#2234 * ssh-keygen(1): When hashing or removing hosts, don't choke on @revoked markers and don't remove @cert-authority markers; bz#2241 * ssh(1): Don't fatal when hostname canonicalisation fails and a ProxyCommand is in use; continue and allow the ProxyCommand to connect anyway (e.g. to a host with a name outside the DNS behind a bastion) * scp(1): When copying local->remote fails during read, don't send uninitialised heap to the remote end. * sftp(1): Fix fatal "el_insertstr failed" errors when tab-completing filenames with a single quote char somewhere in the string; bz#2238 * ssh-keyscan(1): Scan for Ed25519 keys by default. * ssh(1): When using VerifyHostKeyDNS with a DNSSEC resolver, down- convert any certificate keys to plain keys and attempt SSHFP resolution. Prevents a server from skipping SSHFP lookup and forcing a new-hostkey dialog by offering only certificate keys. * sshd(8): Avoid crash at exit via NULL pointer reference; bz#2225 * Fix some strict-alignment errors. Portable OpenSSH * Portable OpenSSH now supports building against libressl-portable. * Portable OpenSSH now requires openssl 0.9.8f or greater. Older versions are no longer supported. * In the OpenSSL version check, allow fix version upgrades (but not downgrades. Debian bug #748150. * sshd(8): On Cygwin, determine privilege separation user at runtime, since it may need to be a domain account. * sshd(8): Don't attempt to use vhangup on Linux. It doesn't work for non-root users, and for them it just messes up the tty settings. * Use CLOCK_BOOTTIME in preference to CLOCK_MONOTONIC when it is available. It considers time spent suspended, thereby ensuring timeouts (e.g. for expiring agent keys) fire correctly. bz#2228 * Add support for ed25519 to opensshd.init init script. * sftp-server(8): On platforms that support it, use prctl() to prevent sftp-server from accessing /proc/self/{mem,maps} Changes since OpenSSH 6.5 ========================= This is primarily a bugfix release. Security: * sshd(8): when using environment passing with a sshd_config(5) AcceptEnv pattern with a wildcard. OpenSSH prior to 6.6 could be tricked into accepting any enviornment variable that contains the characters before the wildcard character. New / changed features: * ssh(1), sshd(8): this release removes the J-PAKE authentication code. This code was experimental, never enabled and had been unmaintained for some time. * ssh(1): when processing Match blocks, skip 'exec' clauses other clauses predicates failed to match. * ssh(1): if hostname canonicalisation is enabled and results in the destination hostname being changed, then re-parse ssh_config(5) files using the new destination hostname. This gives 'Host' and 'Match' directives that use the expanded hostname a chance to be applied. Bugfixes: * ssh(1): avoid spurious "getsockname failed: Bad file descriptor" in ssh -W. bz#2200, debian#738692 * sshd(8): allow the shutdown(2) syscall in seccomp-bpf and systrace sandbox modes, as it is reachable if the connection is terminated during the pre-auth phase. * ssh(1), sshd(8): fix unsigned overflow that in SSH protocol 1 bignum parsing. Minimum key length checks render this bug unexploitable to compromise SSH 1 sessions. * sshd_config(5): clarify behaviour of a keyword that appears in multiple matching Match blocks. bz#2184 * ssh(1): avoid unnecessary hostname lookups when canonicalisation is disabled. bz#2205 * sshd(8): avoid sandbox violation crashes in GSSAPI code by caching the supported list of GSSAPI mechanism OIDs before entering the sandbox. bz#2107 * ssh(1): fix possible crashes in SOCKS4 parsing caused by assumption that the SOCKS username is nul-terminated. * ssh(1): fix regression for UsePrivilegedPort=yes when BindAddress is not specified. * ssh(1), sshd(8): fix memory leak in ECDSA signature verification. * ssh(1): fix matching of 'Host' directives in ssh_config(5) files to be case-insensitive again (regression in 6.5). Portable OpenSSH: * sshd(8): don't fatal if the FreeBSD Capsicum is offered by the system headers and libc but is not supported by the kernel. * Fix build using the HP-UX compiler. Changes since OpenSSH 6.4 ========================= This is a feature-focused release. New features: * ssh(1), sshd(8): Add support for key exchange using elliptic-curve Diffie Hellman in Daniel Bernstein's Curve25519. This key exchange method is the default when both the client and server support it. * ssh(1), sshd(8): Add support for Ed25519 as a public key type. Ed25519 is a elliptic curve signature scheme that offers better security than ECDSA and DSA and good performance. It may be used for both user and host keys. * Add a new private key format that uses a bcrypt KDF to better protect keys at rest. This format is used unconditionally for Ed25519 keys, but may be requested when generating or saving existing keys of other types via the -o ssh-keygen(1) option. We intend to make the new format the default in the near future. Details of the new format are in the PROTOCOL.key file. * ssh(1), sshd(8): Add a new transport cipher "chacha20-poly1305@openssh.com" that combines Daniel Bernstein's ChaCha20 stream cipher and Poly1305 MAC to build an authenticated encryption mode. Details are in the PROTOCOL.chacha20poly1305 file. * ssh(1), sshd(8): Refuse RSA keys from old proprietary clients and servers that use the obsolete RSA+MD5 signature scheme. It will still be possible to connect with these clients/servers but only DSA keys will be accepted, and OpenSSH will refuse connection entirely in a future release. * ssh(1), sshd(8): Refuse old proprietary clients and servers that use a weaker key exchange hash calculation. * ssh(1): Increase the size of the Diffie-Hellman groups requested for each symmetric key size. New values from NIST Special Publication 800-57 with the upper limit specified by RFC4419. * ssh(1), ssh-agent(1): Support PKCS#11 tokens that only provide X.509 certs instead of raw public keys (requested as bz#1908). * ssh(1): Add a ssh_config(5) "Match" keyword that allows conditional configuration to be applied by matching on hostname, user and result of arbitrary commands. * ssh(1): Add support for client-side hostname canonicalisation using a set of DNS suffixes and rules in ssh_config(5). This allows unqualified names to be canonicalised to fully-qualified domain names to eliminate ambiguity when looking up keys in known_hosts or checking host certificate names. * sftp-server(8): Add the ability to whitelist and/or blacklist sftp protocol requests by name. * sftp-server(8): Add a sftp "fsync@openssh.com" to support calling fsync(2) on an open file handle. * sshd(8): Add a ssh_config(5) PermitTTY to disallow TTY allocation, mirroring the longstanding no-pty authorized_keys option. * ssh(1): Add a ssh_config ProxyUseFDPass option that supports the use of ProxyCommands that establish a connection and then pass a connected file descriptor back to ssh(1). This allows the ProxyCommand to exit rather than staying around to transfer data. Bugfixes: * ssh(1), sshd(8): Fix potential stack exhaustion caused by nested certificates. * ssh(1): bz#1211: make BindAddress work with UsePrivilegedPort. * sftp(1): bz#2137: fix the progress meter for resumed transfer. * ssh-add(1): bz#2187: do not request smartcard PIN when removing keys from ssh-agent. * sshd(8): bz#2139: fix re-exec fallback when original sshd binary cannot be executed. * ssh-keygen(1): Make relative-specified certificate expiry times relative to current time and not the validity start time. * sshd(8): bz#2161: fix AuthorizedKeysCommand inside a Match block. * sftp(1): bz#2129: symlinking a file would incorrectly canonicalise the target path. * ssh-agent(1): bz#2175: fix a use-after-free in the PKCS#11 agent helper executable. * sshd(8): Improve logging of sessions to include the user name, remote host and port, the session type (shell, command, etc.) and allocated TTY (if any). * sshd(8): bz#1297: tell the client (via a debug message) when their preferred listen address has been overridden by the server's GatewayPorts setting. * sshd(8): bz#2162: include report port in bad protocol banner message. * sftp(1): bz#2163: fix memory leak in error path in do_readdir(). * sftp(1): bz#2171: don't leak file descriptor on error. * sshd(8): Include the local address and port in "Connection from ..." message (only shown at loglevel>=verbose). Portable OpenSSH: * Please note that this is the last version of Portable OpenSSH that will support versions of OpenSSL prior to 0.9.6. Support (i.e. SSH_OLD_EVP) will be removed following the 6.5p1 release. * Portable OpenSSH will attempt compile and link as a Position Independent Executable on Linux, OS X and OpenBSD on recent gcc- like compilers. Other platforms and older/other compilers may request this using the --with-pie configure flag. * A number of other toolchain-related hardening options are used automatically if available, including -ftrapv to abort on signed integer overflow and options to write-protect dynamic linking information. The use of these options may be disabled using the --without-hardening configure flag. * If the toolchain supports it, one of the -fstack-protector-strong, -fstack-protector-all or -fstack-protector compilation flag are used to add guards to mitigate attacks based on stack overflows. The use of these options may be disabled using the --without-stackprotect configure option. * sshd(8): Add support for pre-authentication sandboxing using the Capsicum API introduced in FreeBSD 10. * Switch to a ChaCha20-based arc4random() PRNG for platforms that do not provide their own. * sshd(8): bz#2156: restore Linux oom_adj setting when handling SIGHUP to maintain behaviour over retart. * sshd(8): bz#2032: use local username in krb5_kuserok check rather than full client name which may be of form user@REALM. * ssh(1), sshd(8): Test for both the presence of ECC NID numbers in OpenSSL and that they actually work. Fedora (at least) has NID_secp521r1 that doesn't work. * bz#2173: use pkg-config --libs to include correct -L location for libedit.
2014-10-19 20:28:33 +04:00
int permit_tty; /* If false, deny pty allocation */
int permit_user_rc; /* If false, deny ~/.ssh/rc execution */
import 5.2 from ftp.openbsd.org
2009-06-08 02:19:00 +04:00
int strict_modes; /* If true, require string home dir modes. */
int tcp_keep_alive; /* If true, set SO_KEEPALIVE. */
from ftp.openbsd.org
2011-07-24 19:08:11 +04:00
int ip_qos_interactive; /* IP ToS/DSCP/class for interactive */
int ip_qos_bulk; /* IP ToS/DSCP/class for bulk traffic */
import 5.2 from ftp.openbsd.org
2009-06-08 02:19:00 +04:00
char *ciphers; /* Supported SSH2 ciphers. */
char *macs; /* Supported SSH2 macs. */
from ftp.openbsd.org
2011-07-24 19:08:11 +04:00
char *kex_algorithms; /* SSH2 kex methods in order of preference. */
Changes since OpenSSH 6.6 ========================= Potentially-incompatible changes * sshd(8): The default set of ciphers and MACs has been altered to remove unsafe algorithms. In particular, CBC ciphers and arcfour* are disabled by default. The full set of algorithms remains available if configured explicitly via the Ciphers and MACs sshd_config options. * sshd(8): Support for tcpwrappers/libwrap has been removed. * OpenSSH 6.5 and 6.6 have a bug that causes ~0.2% of connections using the curve25519-sha256@libssh.org KEX exchange method to fail when connecting with something that implements the specification correctly. OpenSSH 6.7 disables this KEX method when speaking to one of the affected versions. New Features * Major internal refactoring to begin to make part of OpenSSH usable as a library. So far the wire parsing, key handling and KRL code has been refactored. Please note that we do not consider the API stable yet, nor do we offer the library in separable form. * ssh(1), sshd(8): Add support for Unix domain socket forwarding. A remote TCP port may be forwarded to a local Unix domain socket and vice versa or both ends may be a Unix domain socket. * ssh(1), ssh-keygen(1): Add support for SSHFP DNS records for ED25519 key types. * sftp(1): Allow resumption of interrupted uploads. * ssh(1): When rekeying, skip file/DNS lookups of the hostkey if it is the same as the one sent during initial key exchange; bz#2154 * sshd(8): Allow explicit ::1 and 127.0.0.1 forwarding bind addresses when GatewayPorts=no; allows client to choose address family; bz#2222 * sshd(8): Add a sshd_config PermitUserRC option to control whether ~/.ssh/rc is executed, mirroring the no-user-rc authorized_keys option; bz#2160 * ssh(1): Add a %C escape sequence for LocalCommand and ControlPath that expands to a unique identifer based on a hash of the tuple of (local host, remote user, hostname, port). Helps avoid exceeding miserly pathname limits for Unix domain sockets in multiplexing control paths; bz#2220 * sshd(8): Make the "Too many authentication failures" message include the user, source address, port and protocol in a format similar to the authentication success / failure messages; bz#2199 * Added unit and fuzz tests for refactored code. These are run automatically in portable OpenSSH via the "make tests" target. Bugfixes * sshd(8): Fix remote forwarding with the same listen port but different listen address. * ssh(1): Fix inverted test that caused PKCS#11 keys that were explicitly listed in ssh_config or on the commandline not to be preferred. * ssh-keygen(1): Fix bug in KRL generation: multiple consecutive revoked certificate serial number ranges could be serialised to an invalid format. Readers of a broken KRL caused by this bug will fail closed, so no should-have-been-revoked key will be accepted. * ssh(1): Reflect stdio-forward ("ssh -W host:port ...") failures in exit status. Previously we were always returning 0; bz#2255 * ssh(1), ssh-keygen(1): Make Ed25519 keys' title fit properly in the randomart border; bz#2247 * ssh-agent(1): Only cleanup agent socket in the main agent process and not in any subprocesses it may have started (e.g. forked askpass). Fixes agent sockets being zapped when askpass processes fatal(); bz#2236 * ssh-add(1): Make stdout line-buffered; saves partial output getting lost when ssh-add fatal()s part-way through (e.g. when listing keys from an agent that supports key types that ssh-add doesn't); bz#2234 * ssh-keygen(1): When hashing or removing hosts, don't choke on @revoked markers and don't remove @cert-authority markers; bz#2241 * ssh(1): Don't fatal when hostname canonicalisation fails and a ProxyCommand is in use; continue and allow the ProxyCommand to connect anyway (e.g. to a host with a name outside the DNS behind a bastion) * scp(1): When copying local->remote fails during read, don't send uninitialised heap to the remote end. * sftp(1): Fix fatal "el_insertstr failed" errors when tab-completing filenames with a single quote char somewhere in the string; bz#2238 * ssh-keyscan(1): Scan for Ed25519 keys by default. * ssh(1): When using VerifyHostKeyDNS with a DNSSEC resolver, down- convert any certificate keys to plain keys and attempt SSHFP resolution. Prevents a server from skipping SSHFP lookup and forcing a new-hostkey dialog by offering only certificate keys. * sshd(8): Avoid crash at exit via NULL pointer reference; bz#2225 * Fix some strict-alignment errors. Portable OpenSSH * Portable OpenSSH now supports building against libressl-portable. * Portable OpenSSH now requires openssl 0.9.8f or greater. Older versions are no longer supported. * In the OpenSSL version check, allow fix version upgrades (but not downgrades. Debian bug #748150. * sshd(8): On Cygwin, determine privilege separation user at runtime, since it may need to be a domain account. * sshd(8): Don't attempt to use vhangup on Linux. It doesn't work for non-root users, and for them it just messes up the tty settings. * Use CLOCK_BOOTTIME in preference to CLOCK_MONOTONIC when it is available. It considers time spent suspended, thereby ensuring timeouts (e.g. for expiring agent keys) fire correctly. bz#2228 * Add support for ed25519 to opensshd.init init script. * sftp-server(8): On platforms that support it, use prctl() to prevent sftp-server from accessing /proc/self/{mem,maps} Changes since OpenSSH 6.5 ========================= This is primarily a bugfix release. Security: * sshd(8): when using environment passing with a sshd_config(5) AcceptEnv pattern with a wildcard. OpenSSH prior to 6.6 could be tricked into accepting any enviornment variable that contains the characters before the wildcard character. New / changed features: * ssh(1), sshd(8): this release removes the J-PAKE authentication code. This code was experimental, never enabled and had been unmaintained for some time. * ssh(1): when processing Match blocks, skip 'exec' clauses other clauses predicates failed to match. * ssh(1): if hostname canonicalisation is enabled and results in the destination hostname being changed, then re-parse ssh_config(5) files using the new destination hostname. This gives 'Host' and 'Match' directives that use the expanded hostname a chance to be applied. Bugfixes: * ssh(1): avoid spurious "getsockname failed: Bad file descriptor" in ssh -W. bz#2200, debian#738692 * sshd(8): allow the shutdown(2) syscall in seccomp-bpf and systrace sandbox modes, as it is reachable if the connection is terminated during the pre-auth phase. * ssh(1), sshd(8): fix unsigned overflow that in SSH protocol 1 bignum parsing. Minimum key length checks render this bug unexploitable to compromise SSH 1 sessions. * sshd_config(5): clarify behaviour of a keyword that appears in multiple matching Match blocks. bz#2184 * ssh(1): avoid unnecessary hostname lookups when canonicalisation is disabled. bz#2205 * sshd(8): avoid sandbox violation crashes in GSSAPI code by caching the supported list of GSSAPI mechanism OIDs before entering the sandbox. bz#2107 * ssh(1): fix possible crashes in SOCKS4 parsing caused by assumption that the SOCKS username is nul-terminated. * ssh(1): fix regression for UsePrivilegedPort=yes when BindAddress is not specified. * ssh(1), sshd(8): fix memory leak in ECDSA signature verification. * ssh(1): fix matching of 'Host' directives in ssh_config(5) files to be case-insensitive again (regression in 6.5). Portable OpenSSH: * sshd(8): don't fatal if the FreeBSD Capsicum is offered by the system headers and libc but is not supported by the kernel. * Fix build using the HP-UX compiler. Changes since OpenSSH 6.4 ========================= This is a feature-focused release. New features: * ssh(1), sshd(8): Add support for key exchange using elliptic-curve Diffie Hellman in Daniel Bernstein's Curve25519. This key exchange method is the default when both the client and server support it. * ssh(1), sshd(8): Add support for Ed25519 as a public key type. Ed25519 is a elliptic curve signature scheme that offers better security than ECDSA and DSA and good performance. It may be used for both user and host keys. * Add a new private key format that uses a bcrypt KDF to better protect keys at rest. This format is used unconditionally for Ed25519 keys, but may be requested when generating or saving existing keys of other types via the -o ssh-keygen(1) option. We intend to make the new format the default in the near future. Details of the new format are in the PROTOCOL.key file. * ssh(1), sshd(8): Add a new transport cipher "chacha20-poly1305@openssh.com" that combines Daniel Bernstein's ChaCha20 stream cipher and Poly1305 MAC to build an authenticated encryption mode. Details are in the PROTOCOL.chacha20poly1305 file. * ssh(1), sshd(8): Refuse RSA keys from old proprietary clients and servers that use the obsolete RSA+MD5 signature scheme. It will still be possible to connect with these clients/servers but only DSA keys will be accepted, and OpenSSH will refuse connection entirely in a future release. * ssh(1), sshd(8): Refuse old proprietary clients and servers that use a weaker key exchange hash calculation. * ssh(1): Increase the size of the Diffie-Hellman groups requested for each symmetric key size. New values from NIST Special Publication 800-57 with the upper limit specified by RFC4419. * ssh(1), ssh-agent(1): Support PKCS#11 tokens that only provide X.509 certs instead of raw public keys (requested as bz#1908). * ssh(1): Add a ssh_config(5) "Match" keyword that allows conditional configuration to be applied by matching on hostname, user and result of arbitrary commands. * ssh(1): Add support for client-side hostname canonicalisation using a set of DNS suffixes and rules in ssh_config(5). This allows unqualified names to be canonicalised to fully-qualified domain names to eliminate ambiguity when looking up keys in known_hosts or checking host certificate names. * sftp-server(8): Add the ability to whitelist and/or blacklist sftp protocol requests by name. * sftp-server(8): Add a sftp "fsync@openssh.com" to support calling fsync(2) on an open file handle. * sshd(8): Add a ssh_config(5) PermitTTY to disallow TTY allocation, mirroring the longstanding no-pty authorized_keys option. * ssh(1): Add a ssh_config ProxyUseFDPass option that supports the use of ProxyCommands that establish a connection and then pass a connected file descriptor back to ssh(1). This allows the ProxyCommand to exit rather than staying around to transfer data. Bugfixes: * ssh(1), sshd(8): Fix potential stack exhaustion caused by nested certificates. * ssh(1): bz#1211: make BindAddress work with UsePrivilegedPort. * sftp(1): bz#2137: fix the progress meter for resumed transfer. * ssh-add(1): bz#2187: do not request smartcard PIN when removing keys from ssh-agent. * sshd(8): bz#2139: fix re-exec fallback when original sshd binary cannot be executed. * ssh-keygen(1): Make relative-specified certificate expiry times relative to current time and not the validity start time. * sshd(8): bz#2161: fix AuthorizedKeysCommand inside a Match block. * sftp(1): bz#2129: symlinking a file would incorrectly canonicalise the target path. * ssh-agent(1): bz#2175: fix a use-after-free in the PKCS#11 agent helper executable. * sshd(8): Improve logging of sessions to include the user name, remote host and port, the session type (shell, command, etc.) and allocated TTY (if any). * sshd(8): bz#1297: tell the client (via a debug message) when their preferred listen address has been overridden by the server's GatewayPorts setting. * sshd(8): bz#2162: include report port in bad protocol banner message. * sftp(1): bz#2163: fix memory leak in error path in do_readdir(). * sftp(1): bz#2171: don't leak file descriptor on error. * sshd(8): Include the local address and port in "Connection from ..." message (only shown at loglevel>=verbose). Portable OpenSSH: * Please note that this is the last version of Portable OpenSSH that will support versions of OpenSSL prior to 0.9.6. Support (i.e. SSH_OLD_EVP) will be removed following the 6.5p1 release. * Portable OpenSSH will attempt compile and link as a Position Independent Executable on Linux, OS X and OpenBSD on recent gcc- like compilers. Other platforms and older/other compilers may request this using the --with-pie configure flag. * A number of other toolchain-related hardening options are used automatically if available, including -ftrapv to abort on signed integer overflow and options to write-protect dynamic linking information. The use of these options may be disabled using the --without-hardening configure flag. * If the toolchain supports it, one of the -fstack-protector-strong, -fstack-protector-all or -fstack-protector compilation flag are used to add guards to mitigate attacks based on stack overflows. The use of these options may be disabled using the --without-stackprotect configure option. * sshd(8): Add support for pre-authentication sandboxing using the Capsicum API introduced in FreeBSD 10. * Switch to a ChaCha20-based arc4random() PRNG for platforms that do not provide their own. * sshd(8): bz#2156: restore Linux oom_adj setting when handling SIGHUP to maintain behaviour over retart. * sshd(8): bz#2032: use local username in krb5_kuserok check rather than full client name which may be of form user@REALM. * ssh(1), sshd(8): Test for both the presence of ECC NID numbers in OpenSSL and that they actually work. Fedora (at least) has NID_secp521r1 that doesn't work. * bz#2173: use pkg-config --libs to include correct -L location for libedit.
2014-10-19 20:28:33 +04:00
struct ForwardOptions fwd_opts; /* forwarding options */
import 5.2 from ftp.openbsd.org
2009-06-08 02:19:00 +04:00
SyslogFacility log_facility; /* Facility for system logging. */
LogLevel log_level; /* Level for system logging. */
OpenSSH 8.5/8.5p1 (2021-03-03) OpenSSH 8.5 was released on 2021-03-03. It is available from the mirrors listed at https://www.openssh.com/. OpenSSH is a 100% complete SSH protocol 2.0 implementation and includes sftp client and server support. Once again, we would like to thank the OpenSSH community for their continued support of the project, especially those who contributed code or patches, reported bugs, tested snapshots or donated to the project. More information on donations may be found at: https://www.openssh.com/donations.html Future deprecation notice ========================= It is now possible[1] to perform chosen-prefix attacks against the SHA-1 algorithm for less than USD$50K. In the SSH protocol, the "ssh-rsa" signature scheme uses the SHA-1 hash algorithm in conjunction with the RSA public key algorithm. OpenSSH will disable this signature scheme by default in the near future. Note that the deactivation of "ssh-rsa" signatures does not necessarily require cessation of use for RSA keys. In the SSH protocol, keys may be capable of signing using multiple algorithms. In particular, "ssh-rsa" keys are capable of signing using "rsa-sha2-256" (RSA/SHA256), "rsa-sha2-512" (RSA/SHA512) and "ssh-rsa" (RSA/SHA1). Only the last of these is being turned off by default. This algorithm is unfortunately still used widely despite the existence of better alternatives, being the only remaining public key signature algorithm specified by the original SSH RFCs that is still enabled by default. The better alternatives include: * The RFC8332 RSA SHA-2 signature algorithms rsa-sha2-256/512. These algorithms have the advantage of using the same key type as "ssh-rsa" but use the safe SHA-2 hash algorithms. These have been supported since OpenSSH 7.2 and are already used by default if the client and server support them. * The RFC8709 ssh-ed25519 signature algorithm. It has been supported in OpenSSH since release 6.5. * The RFC5656 ECDSA algorithms: ecdsa-sha2-nistp256/384/521. These have been supported by OpenSSH since release 5.7. To check whether a server is using the weak ssh-rsa public key algorithm, for host authentication, try to connect to it after removing the ssh-rsa algorithm from ssh(1)'s allowed list: ssh -oHostKeyAlgorithms=-ssh-rsa user@host If the host key verification fails and no other supported host key types are available, the server software on that host should be upgraded. This release enables the UpdateHostKeys option by default to assist the client by automatically migrating to better algorithms. [1] "SHA-1 is a Shambles: First Chosen-Prefix Collision on SHA-1 and Application to the PGP Web of Trust" Leurent, G and Peyrin, T (2020) https://eprint.iacr.org/2020/014.pdf Security ======== * ssh-agent(1): fixed a double-free memory corruption that was introduced in OpenSSH 8.2 . We treat all such memory faults as potentially exploitable. This bug could be reached by an attacker with access to the agent socket. On modern operating systems where the OS can provide information about the user identity connected to a socket, OpenSSH ssh-agent and sshd limit agent socket access only to the originating user and root. Additional mitigation may be afforded by the system's malloc(3)/free(3) implementation, if it detects double-free conditions. The most likely scenario for exploitation is a user forwarding an agent either to an account shared with a malicious user or to a host with an attacker holding root access. * Portable sshd(8): Prevent excessively long username going to PAM. This is a mitigation for a buffer overflow in Solaris' PAM username handling (CVE-2020-14871), and is only enabled for Sun-derived PAM implementations. This is not a problem in sshd itself, it only prevents sshd from being used as a vector to attack Solaris' PAM. It does not prevent the bug in PAM from being exploited via some other PAM application. GHPR212 Potentially-incompatible changes ================================ This release includes a number of changes that may affect existing configurations: * ssh(1), sshd(8): this release changes the first-preference signature algorithm from ECDSA to ED25519. * ssh(1), sshd(8): set the TOS/DSCP specified in the configuration for interactive use prior to TCP connect. The connection phase of the SSH session is time-sensitive and often explicitly interactive. The ultimate interactive/bulk TOS/DSCP will be set after authentication completes. * ssh(1), sshd(8): remove the pre-standardization cipher rijndael-cbc@lysator.liu.se. It is an alias for aes256-cbc before it was standardized in RFC4253 (2006), has been deprecated and disabled by default since OpenSSH 7.2 (2016) and was only briefly documented in ssh.1 in 2001. * ssh(1), sshd(8): update/replace the experimental post-quantum hybrid key exchange method based on Streamlined NTRU Prime coupled with X25519. The previous sntrup4591761x25519-sha512@tinyssh.org method is replaced with sntrup761x25519-sha512@openssh.com. Per its designers, the sntrup4591761 algorithm was superseded almost two years ago by sntrup761. (note this both the updated method and the one that it replaced are disabled by default) * ssh(1): disable CheckHostIP by default. It provides insignificant benefits while making key rotation significantly more difficult, especially for hosts behind IP-based load-balancers. Changes since OpenSSH 8.4 ========================= New features ------------ * ssh(1): this release enables UpdateHostkeys by default subject to some conservative preconditions: - The key was matched in the UserKnownHostsFile (and not in the GlobalKnownHostsFile). - The same key does not exist under another name. - A certificate host key is not in use. - known_hosts contains no matching wildcard hostname pattern. - VerifyHostKeyDNS is not enabled. - The default UserKnownHostsFile is in use. We expect some of these conditions will be modified or relaxed in future. * ssh(1), sshd(8): add a new LogVerbose configuration directive for that allows forcing maximum debug logging by file/function/line pattern-lists. * ssh(1): when prompting the user to accept a new hostkey, display any other host names/addresses already associated with the key. * ssh(1): allow UserKnownHostsFile=none to indicate that no known_hosts file should be used to identify host keys. * ssh(1): add a ssh_config KnownHostsCommand option that allows the client to obtain known_hosts data from a command in addition to the usual files. * ssh(1): add a ssh_config PermitRemoteOpen option that allows the client to restrict the destination when RemoteForward is used with SOCKS. * ssh(1): for FIDO keys, if a signature operation fails with a "incorrect PIN" reason and no PIN was initially requested from the user, then request a PIN and retry the operation. This supports some biometric devices that fall back to requiring PIN when reading of the biometric failed, and devices that require PINs for all hosted credentials. * sshd(8): implement client address-based rate-limiting via new sshd_config(5) PerSourceMaxStartups and PerSourceNetBlockSize directives that provide more fine-grained control on a per-origin address basis than the global MaxStartups limit. Bugfixes -------- * ssh(1): Prefix keyboard interactive prompts with "(user@host)" to make it easier to determine which connection they are associated with in cases like scp -3, ProxyJump, etc. bz#3224 * sshd(8): fix sshd_config SetEnv directives located inside Match blocks. GHPR201 * ssh(1): when requesting a FIDO token touch on stderr, inform the user once the touch has been recorded. * ssh(1): prevent integer overflow when ridiculously large ConnectTimeout values are specified, capping the effective value (for most platforms) at 24 days. bz#3229 * ssh(1): consider the ECDSA key subtype when ordering host key algorithms in the client. * ssh(1), sshd(8): rename the PubkeyAcceptedKeyTypes keyword to PubkeyAcceptedAlgorithms. The previous name incorrectly suggested that it control allowed key algorithms, when this option actually specifies the signature algorithms that are accepted. The previous name remains available as an alias. bz#3253 * ssh(1), sshd(8): similarly, rename HostbasedKeyTypes (ssh) and HostbasedAcceptedKeyTypes (sshd) to HostbasedAcceptedAlgorithms. * sftp-server(8): add missing lsetstat@openssh.com documentation and advertisement in the server's SSH2_FXP_VERSION hello packet. * ssh(1), sshd(8): more strictly enforce KEX state-machine by banning packet types once they are received. Fixes memleak caused by duplicate SSH2_MSG_KEX_DH_GEX_REQUEST (oss-fuzz #30078). * sftp(1): allow the full range of UIDs/GIDs for chown/chgrp on 32bit platforms instead of being limited by LONG_MAX. bz#3206 * Minor man page fixes (capitalization, commas, etc.) bz#3223 * sftp(1): when doing an sftp recursive upload or download of a read-only directory, ensure that the directory is created with write and execute permissions in the interim so that the transfer can actually complete, then set the directory permission as the final step. bz#3222 * ssh-keygen(1): document the -Z, check the validity of its argument earlier and provide a better error message if it's not correct. bz#2879 * ssh(1): ignore comments at the end of config lines in ssh_config, similar to what we already do for sshd_config. bz#2320 * sshd_config(5): mention that DisableForwarding is valid in a sshd_config Match block. bz3239 * sftp(1): fix incorrect sorting of "ls -ltr" under some circumstances. bz3248. * ssh(1), sshd(8): fix potential integer truncation of (unlikely) timeout values. bz#3250 * ssh(1): make hostbased authentication send the signature algorithm in its SSH2_MSG_USERAUTH_REQUEST packets instead of the key type. This make HostbasedAcceptedAlgorithms do what it is supposed to - filter on signature algorithm and not key type. Portability ----------- * sshd(8): add a number of platform-specific syscalls to the Linux seccomp-bpf sandbox. bz#3232 bz#3260 * sshd(8): remove debug message from sigchld handler that could cause deadlock on some platforms. bz#3259 * Sync contrib/ssh-copy-id with upstream. * unittests: add a hostname function for systems that don't have it. Some systems don't have a hostname command (it's not required by POSIX). The do have uname -n (which is), but not all of those have it report the FQDN. Checksums: ========== - SHA1 (openssh-8.5.tar.gz) = 04cae43c389fb411227c01219e4eb46e3113f34e - SHA256 (openssh-8.5.tar.gz) = 5qB2CgzNG4io4DmChTjHgCWqRWvEOvCKJskLdJCz+SU= - SHA1 (openssh-8.5p1.tar.gz) = 72eadcbe313b07b1dd3b693e41d3cd56d354e24e - SHA256 (openssh-8.5p1.tar.gz) = 9S8/QdQpqpkY44zyAK8iXM3Y5m8FLaVyhwyJc3ZG7CU= Please note that the SHA256 signatures are base64 encoded and not hexadecimal (which is the default for most checksum tools). The PGP key used to sign the releases is available from the mirror sites: https://cdn.openbsd.org/pub/OpenBSD/OpenSSH/RELEASE_KEY.asc Please note that the OpenPGP key used to sign releases has been rotated for this release. The new key has been signed by the previous key to provide continuity. Reporting Bugs: =============== - Please read https://www.openssh.com/report.html Security bugs should be reported directly to openssh@openssh.com
2021-03-05 20:45:24 +03:00
u_int num_log_verbose; /* Verbose log overrides */
char **log_verbose;
import 5.2 from ftp.openbsd.org
2009-06-08 02:19:00 +04:00
int hostbased_authentication; /* If true, permit ssh2 hostbased auth */
int hostbased_uses_name_from_packet_only; /* experimental */
OpenSSH 8.5/8.5p1 (2021-03-03) OpenSSH 8.5 was released on 2021-03-03. It is available from the mirrors listed at https://www.openssh.com/. OpenSSH is a 100% complete SSH protocol 2.0 implementation and includes sftp client and server support. Once again, we would like to thank the OpenSSH community for their continued support of the project, especially those who contributed code or patches, reported bugs, tested snapshots or donated to the project. More information on donations may be found at: https://www.openssh.com/donations.html Future deprecation notice ========================= It is now possible[1] to perform chosen-prefix attacks against the SHA-1 algorithm for less than USD$50K. In the SSH protocol, the "ssh-rsa" signature scheme uses the SHA-1 hash algorithm in conjunction with the RSA public key algorithm. OpenSSH will disable this signature scheme by default in the near future. Note that the deactivation of "ssh-rsa" signatures does not necessarily require cessation of use for RSA keys. In the SSH protocol, keys may be capable of signing using multiple algorithms. In particular, "ssh-rsa" keys are capable of signing using "rsa-sha2-256" (RSA/SHA256), "rsa-sha2-512" (RSA/SHA512) and "ssh-rsa" (RSA/SHA1). Only the last of these is being turned off by default. This algorithm is unfortunately still used widely despite the existence of better alternatives, being the only remaining public key signature algorithm specified by the original SSH RFCs that is still enabled by default. The better alternatives include: * The RFC8332 RSA SHA-2 signature algorithms rsa-sha2-256/512. These algorithms have the advantage of using the same key type as "ssh-rsa" but use the safe SHA-2 hash algorithms. These have been supported since OpenSSH 7.2 and are already used by default if the client and server support them. * The RFC8709 ssh-ed25519 signature algorithm. It has been supported in OpenSSH since release 6.5. * The RFC5656 ECDSA algorithms: ecdsa-sha2-nistp256/384/521. These have been supported by OpenSSH since release 5.7. To check whether a server is using the weak ssh-rsa public key algorithm, for host authentication, try to connect to it after removing the ssh-rsa algorithm from ssh(1)'s allowed list: ssh -oHostKeyAlgorithms=-ssh-rsa user@host If the host key verification fails and no other supported host key types are available, the server software on that host should be upgraded. This release enables the UpdateHostKeys option by default to assist the client by automatically migrating to better algorithms. [1] "SHA-1 is a Shambles: First Chosen-Prefix Collision on SHA-1 and Application to the PGP Web of Trust" Leurent, G and Peyrin, T (2020) https://eprint.iacr.org/2020/014.pdf Security ======== * ssh-agent(1): fixed a double-free memory corruption that was introduced in OpenSSH 8.2 . We treat all such memory faults as potentially exploitable. This bug could be reached by an attacker with access to the agent socket. On modern operating systems where the OS can provide information about the user identity connected to a socket, OpenSSH ssh-agent and sshd limit agent socket access only to the originating user and root. Additional mitigation may be afforded by the system's malloc(3)/free(3) implementation, if it detects double-free conditions. The most likely scenario for exploitation is a user forwarding an agent either to an account shared with a malicious user or to a host with an attacker holding root access. * Portable sshd(8): Prevent excessively long username going to PAM. This is a mitigation for a buffer overflow in Solaris' PAM username handling (CVE-2020-14871), and is only enabled for Sun-derived PAM implementations. This is not a problem in sshd itself, it only prevents sshd from being used as a vector to attack Solaris' PAM. It does not prevent the bug in PAM from being exploited via some other PAM application. GHPR212 Potentially-incompatible changes ================================ This release includes a number of changes that may affect existing configurations: * ssh(1), sshd(8): this release changes the first-preference signature algorithm from ECDSA to ED25519. * ssh(1), sshd(8): set the TOS/DSCP specified in the configuration for interactive use prior to TCP connect. The connection phase of the SSH session is time-sensitive and often explicitly interactive. The ultimate interactive/bulk TOS/DSCP will be set after authentication completes. * ssh(1), sshd(8): remove the pre-standardization cipher rijndael-cbc@lysator.liu.se. It is an alias for aes256-cbc before it was standardized in RFC4253 (2006), has been deprecated and disabled by default since OpenSSH 7.2 (2016) and was only briefly documented in ssh.1 in 2001. * ssh(1), sshd(8): update/replace the experimental post-quantum hybrid key exchange method based on Streamlined NTRU Prime coupled with X25519. The previous sntrup4591761x25519-sha512@tinyssh.org method is replaced with sntrup761x25519-sha512@openssh.com. Per its designers, the sntrup4591761 algorithm was superseded almost two years ago by sntrup761. (note this both the updated method and the one that it replaced are disabled by default) * ssh(1): disable CheckHostIP by default. It provides insignificant benefits while making key rotation significantly more difficult, especially for hosts behind IP-based load-balancers. Changes since OpenSSH 8.4 ========================= New features ------------ * ssh(1): this release enables UpdateHostkeys by default subject to some conservative preconditions: - The key was matched in the UserKnownHostsFile (and not in the GlobalKnownHostsFile). - The same key does not exist under another name. - A certificate host key is not in use. - known_hosts contains no matching wildcard hostname pattern. - VerifyHostKeyDNS is not enabled. - The default UserKnownHostsFile is in use. We expect some of these conditions will be modified or relaxed in future. * ssh(1), sshd(8): add a new LogVerbose configuration directive for that allows forcing maximum debug logging by file/function/line pattern-lists. * ssh(1): when prompting the user to accept a new hostkey, display any other host names/addresses already associated with the key. * ssh(1): allow UserKnownHostsFile=none to indicate that no known_hosts file should be used to identify host keys. * ssh(1): add a ssh_config KnownHostsCommand option that allows the client to obtain known_hosts data from a command in addition to the usual files. * ssh(1): add a ssh_config PermitRemoteOpen option that allows the client to restrict the destination when RemoteForward is used with SOCKS. * ssh(1): for FIDO keys, if a signature operation fails with a "incorrect PIN" reason and no PIN was initially requested from the user, then request a PIN and retry the operation. This supports some biometric devices that fall back to requiring PIN when reading of the biometric failed, and devices that require PINs for all hosted credentials. * sshd(8): implement client address-based rate-limiting via new sshd_config(5) PerSourceMaxStartups and PerSourceNetBlockSize directives that provide more fine-grained control on a per-origin address basis than the global MaxStartups limit. Bugfixes -------- * ssh(1): Prefix keyboard interactive prompts with "(user@host)" to make it easier to determine which connection they are associated with in cases like scp -3, ProxyJump, etc. bz#3224 * sshd(8): fix sshd_config SetEnv directives located inside Match blocks. GHPR201 * ssh(1): when requesting a FIDO token touch on stderr, inform the user once the touch has been recorded. * ssh(1): prevent integer overflow when ridiculously large ConnectTimeout values are specified, capping the effective value (for most platforms) at 24 days. bz#3229 * ssh(1): consider the ECDSA key subtype when ordering host key algorithms in the client. * ssh(1), sshd(8): rename the PubkeyAcceptedKeyTypes keyword to PubkeyAcceptedAlgorithms. The previous name incorrectly suggested that it control allowed key algorithms, when this option actually specifies the signature algorithms that are accepted. The previous name remains available as an alias. bz#3253 * ssh(1), sshd(8): similarly, rename HostbasedKeyTypes (ssh) and HostbasedAcceptedKeyTypes (sshd) to HostbasedAcceptedAlgorithms. * sftp-server(8): add missing lsetstat@openssh.com documentation and advertisement in the server's SSH2_FXP_VERSION hello packet. * ssh(1), sshd(8): more strictly enforce KEX state-machine by banning packet types once they are received. Fixes memleak caused by duplicate SSH2_MSG_KEX_DH_GEX_REQUEST (oss-fuzz #30078). * sftp(1): allow the full range of UIDs/GIDs for chown/chgrp on 32bit platforms instead of being limited by LONG_MAX. bz#3206 * Minor man page fixes (capitalization, commas, etc.) bz#3223 * sftp(1): when doing an sftp recursive upload or download of a read-only directory, ensure that the directory is created with write and execute permissions in the interim so that the transfer can actually complete, then set the directory permission as the final step. bz#3222 * ssh-keygen(1): document the -Z, check the validity of its argument earlier and provide a better error message if it's not correct. bz#2879 * ssh(1): ignore comments at the end of config lines in ssh_config, similar to what we already do for sshd_config. bz#2320 * sshd_config(5): mention that DisableForwarding is valid in a sshd_config Match block. bz3239 * sftp(1): fix incorrect sorting of "ls -ltr" under some circumstances. bz3248. * ssh(1), sshd(8): fix potential integer truncation of (unlikely) timeout values. bz#3250 * ssh(1): make hostbased authentication send the signature algorithm in its SSH2_MSG_USERAUTH_REQUEST packets instead of the key type. This make HostbasedAcceptedAlgorithms do what it is supposed to - filter on signature algorithm and not key type. Portability ----------- * sshd(8): add a number of platform-specific syscalls to the Linux seccomp-bpf sandbox. bz#3232 bz#3260 * sshd(8): remove debug message from sigchld handler that could cause deadlock on some platforms. bz#3259 * Sync contrib/ssh-copy-id with upstream. * unittests: add a hostname function for systems that don't have it. Some systems don't have a hostname command (it's not required by POSIX). The do have uname -n (which is), but not all of those have it report the FQDN. Checksums: ========== - SHA1 (openssh-8.5.tar.gz) = 04cae43c389fb411227c01219e4eb46e3113f34e - SHA256 (openssh-8.5.tar.gz) = 5qB2CgzNG4io4DmChTjHgCWqRWvEOvCKJskLdJCz+SU= - SHA1 (openssh-8.5p1.tar.gz) = 72eadcbe313b07b1dd3b693e41d3cd56d354e24e - SHA256 (openssh-8.5p1.tar.gz) = 9S8/QdQpqpkY44zyAK8iXM3Y5m8FLaVyhwyJc3ZG7CU= Please note that the SHA256 signatures are base64 encoded and not hexadecimal (which is the default for most checksum tools). The PGP key used to sign the releases is available from the mirror sites: https://cdn.openbsd.org/pub/OpenBSD/OpenSSH/RELEASE_KEY.asc Please note that the OpenPGP key used to sign releases has been rotated for this release. The new key has been signed by the previous key to provide continuity. Reporting Bugs: =============== - Please read https://www.openssh.com/report.html Security bugs should be reported directly to openssh@openssh.com
2021-03-05 20:45:24 +03:00
char *hostbased_accepted_algos; /* Algos allowed for hostbased */
import openssh-7.0 Changes since OpenSSH 6.9 ========================= This focus of this release is primarily to deprecate weak, legacy and/or unsafe cryptography. Security -------- * sshd(8): OpenSSH 6.8 and 6.9 incorrectly set TTYs to be world- writable. Local attackers may be able to write arbitrary messages to logged-in users, including terminal escape sequences. Reported by Nikolay Edigaryev. * sshd(8): Portable OpenSSH only: Fixed a privilege separation weakness related to PAM support. Attackers who could successfully compromise the pre-authentication process for remote code execution and who had valid credentials on the host could impersonate other users. Reported by Moritz Jodeit. * sshd(8): Portable OpenSSH only: Fixed a use-after-free bug related to PAM support that was reachable by attackers who could compromise the pre-authentication process for remote code execution. Also reported by Moritz Jodeit. * sshd(8): fix circumvention of MaxAuthTries using keyboard- interactive authentication. By specifying a long, repeating keyboard-interactive "devices" string, an attacker could request the same authentication method be tried thousands of times in a single pass. The LoginGraceTime timeout in sshd(8) and any authentication failure delays implemented by the authentication mechanism itself were still applied. Found by Kingcope. Potentially-incompatible Changes -------------------------------- * Support for the legacy SSH version 1 protocol is disabled by default at compile time. * Support for the 1024-bit diffie-hellman-group1-sha1 key exchange is disabled by default at run-time. It may be re-enabled using the instructions at http://www.openssh.com/legacy.html * Support for ssh-dss, ssh-dss-cert-* host and user keys is disabled by default at run-time. These may be re-enabled using the instructions at http://www.openssh.com/legacy.html * Support for the legacy v00 cert format has been removed. * The default for the sshd_config(5) PermitRootLogin option has changed from "yes" to "prohibit-password". * PermitRootLogin=without-password/prohibit-password now bans all interactive authentication methods, allowing only public-key, hostbased and GSSAPI authentication (previously it permitted keyboard-interactive and password-less authentication if those were enabled). New Features ------------ * ssh_config(5): add PubkeyAcceptedKeyTypes option to control which public key types are available for user authentication. * sshd_config(5): add HostKeyAlgorithms option to control which public key types are offered for host authentications. * ssh(1), sshd(8): extend Ciphers, MACs, KexAlgorithms, HostKeyAlgorithms, PubkeyAcceptedKeyTypes and HostbasedKeyTypes options to allow appending to the default set of algorithms instead of replacing it. Options may now be prefixed with a '+' to append to the default, e.g. "HostKeyAlgorithms=+ssh-dss". * sshd_config(5): PermitRootLogin now accepts an argument of 'prohibit-password' as a less-ambiguous synonym of 'without- password'. Bugfixes -------- * ssh(1), sshd(8): add compatability workarounds for Cisco and more PuTTY versions. bz#2424 * Fix some omissions and errors in the PROTOCOL and PROTOCOL.mux documentation relating to Unix domain socket forwarding; bz#2421 bz#2422 * ssh(1): Improve the ssh(1) manual page to include a better description of Unix domain socket forwarding; bz#2423 * ssh(1), ssh-agent(1): skip uninitialised PKCS#11 slots, fixing failures to load keys when they are present. bz#2427 * ssh(1), ssh-agent(1): do not ignore PKCS#11 hosted keys that wth empty CKA_ID; bz#2429 * sshd(8): clarify documentation for UseDNS option; bz#2045
2015-08-13 13:25:35 +03:00
char *hostkeyalgorithms; /* SSH2 server key types */
Import 8.0: Security ======== This release contains mitigation for a weakness in the scp(1) tool and protocol (CVE-2019-6111): when copying files from a remote system to a local directory, scp(1) did not verify that the filenames that the server sent matched those requested by the client. This could allow a hostile server to create or clobber unexpected local files with attacker-controlled content. This release adds client-side checking that the filenames sent from the server match the command-line request, The scp protocol is outdated, inflexible and not readily fixed. We recommend the use of more modern protocols like sftp and rsync for file transfer instead. Potentially-incompatible changes ================================ This release includes a number of changes that may affect existing configurations: * scp(1): Relating to the above changes to scp(1); the scp protocol relies on the remote shell for wildcard expansion, so there is no infallible way for the client's wildcard matching to perfectly reflect the server's. If there is a difference between client and server wildcard expansion, the client may refuse files from the server. For this reason, we have provided a new "-T" flag to scp that disables these client-side checks at the risk of reintroducing the attack described above. * sshd(8): Remove support for obsolete "host/port" syntax. Slash- separated host/port was added in 2001 as an alternative to host:port syntax for the benefit of IPv6 users. These days there are establised standards for this like [::1]:22 and the slash syntax is easily mistaken for CIDR notation, which OpenSSH supports for some things. Remove the slash notation from ListenAddress and PermitOpen; bz#2335 Changes since OpenSSH 7.9 ========================= This release is focused on new features and internal refactoring. New Features ------------ * ssh(1), ssh-agent(1), ssh-add(1): Add support for ECDSA keys in PKCS#11 tokens. * ssh(1), sshd(8): Add experimental quantum-computing resistant key exchange method, based on a combination of Streamlined NTRU Prime 4591^761 and X25519. * ssh-keygen(1): Increase the default RSA key size to 3072 bits, following NIST Special Publication 800-57's guidance for a 128-bit equivalent symmetric security level. * ssh(1): Allow "PKCS11Provider=none" to override later instances of the PKCS11Provider directive in ssh_config; bz#2974 * sshd(8): Add a log message for situations where a connection is dropped for attempting to run a command but a sshd_config ForceCommand=internal-sftp restriction is in effect; bz#2960 * ssh(1): When prompting whether to record a new host key, accept the key fingerprint as a synonym for "yes". This allows the user to paste a fingerprint obtained out of band at the prompt and have the client do the comparison for you. * ssh-keygen(1): When signing multiple certificates on a single command-line invocation, allow automatically incrementing the certificate serial number. * scp(1), sftp(1): Accept -J option as an alias to ProxyJump on the scp and sftp command-lines. * ssh-agent(1), ssh-pkcs11-helper(8), ssh-add(1): Accept "-v" command-line flags to increase the verbosity of output; pass verbose flags though to subprocesses, such as ssh-pkcs11-helper started from ssh-agent. * ssh-add(1): Add a "-T" option to allowing testing whether keys in an agent are usable by performing a signature and a verification. * sftp-server(8): Add a "lsetstat@openssh.com" protocol extension that replicates the functionality of the existing SSH2_FXP_SETSTAT operation but does not follow symlinks. bz#2067 * sftp(1): Add "-h" flag to chown/chgrp/chmod commands to request they do not follow symlinks. * sshd(8): Expose $SSH_CONNECTION in the PAM environment. This makes the connection 4-tuple available to PAM modules that wish to use it in decision-making. bz#2741 * sshd(8): Add a ssh_config "Match final" predicate Matches in same pass as "Match canonical" but doesn't require hostname canonicalisation be enabled. bz#2906 * sftp(1): Support a prefix of '@' to suppress echo of sftp batch commands; bz#2926 * ssh-keygen(1): When printing certificate contents using "ssh-keygen -Lf /path/certificate", include the algorithm that the CA used to sign the cert. Bugfixes -------- * sshd(8): Fix authentication failures when sshd_config contains "AuthenticationMethods any" inside a Match block that overrides a more restrictive default. * sshd(8): Avoid sending duplicate keepalives when ClientAliveCount is enabled. * sshd(8): Fix two race conditions related to SIGHUP daemon restart. Remnant file descriptors in recently-forked child processes could block the parent sshd's attempt to listen(2) to the configured addresses. Also, the restarting parent sshd could exit before any child processes that were awaiting their re-execution state had completed reading it, leaving them in a fallback path. * ssh(1): Fix stdout potentially being redirected to /dev/null when ProxyCommand=- was in use. * sshd(8): Avoid sending SIGPIPE to child processes if they attempt to write to stderr after their parent processes have exited; bz#2071 * ssh(1): Fix bad interaction between the ssh_config ConnectTimeout and ConnectionAttempts directives - connection attempts after the first were ignoring the requested timeout; bz#2918 * ssh-keyscan(1): Return a non-zero exit status if no keys were found; bz#2903 * scp(1): Sanitize scp filenames to allow UTF-8 characters without terminal control sequences; bz#2434 * sshd(8): Fix confusion between ClientAliveInterval and time-based RekeyLimit that could cause connections to be incorrectly closed. bz#2757 * ssh(1), ssh-add(1): Correct some bugs in PKCS#11 token PIN handling at initial token login. The attempt to read the PIN could be skipped in some cases, particularly on devices with integrated PIN readers. This would lead to an inability to retrieve keys from these tokens. bz#2652 * ssh(1), ssh-add(1): Support keys on PKCS#11 tokens that set the CKA_ALWAYS_AUTHENTICATE flag by requring a fresh login after the C_SignInit operation. bz#2638 * ssh(1): Improve documentation for ProxyJump/-J, clarifying that local configuration does not apply to jump hosts. * ssh-keygen(1): Clarify manual - ssh-keygen -e only writes public keys, not private. * ssh(1), sshd(8): be more strict in processing protocol banners, allowing \r characters only immediately before \n. * Various: fix a number of memory leaks, including bz#2942 and bz#2938 * scp(1), sftp(1): fix calculation of initial bandwidth limits. Account for bytes written before the timer starts and adjust the schedule on which recalculations are performed. Avoids an initial burst of traffic and yields more accurate bandwidth limits; bz#2927 * sshd(8): Only consider the ext-info-c extension during the initial key eschange. It shouldn't be sent in subsequent ones, but if it is present we should ignore it. This prevents sshd from sending a SSH_MSG_EXT_INFO for REKEX for buggy these clients. bz#2929 * ssh-keygen(1): Clarify manual that ssh-keygen -F (find host in authorized_keys) and -R (remove host from authorized_keys) options may accept either a bare hostname or a [hostname]:port combo. bz#2935 * ssh(1): Don't attempt to connect to empty SSH_AUTH_SOCK; bz#2936 * sshd(8): Silence error messages when sshd fails to load some of the default host keys. Failure to load an explicitly-configured hostkey is still an error, and failure to load any host key is still fatal. pr/103 * ssh(1): Redirect stderr of ProxyCommands to /dev/null when ssh is started with ControlPersist; prevents random ProxyCommand output from interfering with session output. * ssh(1): The ssh client was keeping a redundant ssh-agent socket (leftover from authentication) around for the life of the connection; bz#2912 * sshd(8): Fix bug in HostbasedAcceptedKeyTypes and PubkeyAcceptedKeyTypes options. If only RSA-SHA2 siganture types were specified, then authentication would always fail for RSA keys as the monitor checks only the base key (not the signature algorithm) type against *AcceptedKeyTypes. bz#2746 * ssh(1): Request correct signature types from ssh-agent when certificate keys and RSA-SHA2 signatures are in use. Portability ----------- * sshd(8): On Cygwin, run as SYSTEM where possible, using S4U for token creation if it supports MsV1_0 S4U Logon. * sshd(8): On Cygwin, use custom user/group matching code that respects the OS' behaviour of case-insensitive matching. * sshd(8): Don't set $MAIL if UsePAM=yes as PAM typically specifies the user environment if it's enabled; bz#2937 * sshd(8) Cygwin: Change service name to cygsshd to avoid collision with Microsoft's OpenSSH port. * Allow building against OpenSSL -dev (3.x) * Fix a number of build problems against version configurations and versions of OpenSSL. Including bz#2931 and bz#2921 * Improve warnings in cygwin service setup. bz#2922 * Remove hardcoded service name in cygwin setup. bz#2922
2019-04-20 20:13:53 +03:00
char *ca_sign_algorithms; /* Allowed CA signature algorithms */
import 5.2 from ftp.openbsd.org
2009-06-08 02:19:00 +04:00
int pubkey_authentication; /* If true, permit ssh2 pubkey authentication. */
OpenSSH 8.5/8.5p1 (2021-03-03) OpenSSH 8.5 was released on 2021-03-03. It is available from the mirrors listed at https://www.openssh.com/. OpenSSH is a 100% complete SSH protocol 2.0 implementation and includes sftp client and server support. Once again, we would like to thank the OpenSSH community for their continued support of the project, especially those who contributed code or patches, reported bugs, tested snapshots or donated to the project. More information on donations may be found at: https://www.openssh.com/donations.html Future deprecation notice ========================= It is now possible[1] to perform chosen-prefix attacks against the SHA-1 algorithm for less than USD$50K. In the SSH protocol, the "ssh-rsa" signature scheme uses the SHA-1 hash algorithm in conjunction with the RSA public key algorithm. OpenSSH will disable this signature scheme by default in the near future. Note that the deactivation of "ssh-rsa" signatures does not necessarily require cessation of use for RSA keys. In the SSH protocol, keys may be capable of signing using multiple algorithms. In particular, "ssh-rsa" keys are capable of signing using "rsa-sha2-256" (RSA/SHA256), "rsa-sha2-512" (RSA/SHA512) and "ssh-rsa" (RSA/SHA1). Only the last of these is being turned off by default. This algorithm is unfortunately still used widely despite the existence of better alternatives, being the only remaining public key signature algorithm specified by the original SSH RFCs that is still enabled by default. The better alternatives include: * The RFC8332 RSA SHA-2 signature algorithms rsa-sha2-256/512. These algorithms have the advantage of using the same key type as "ssh-rsa" but use the safe SHA-2 hash algorithms. These have been supported since OpenSSH 7.2 and are already used by default if the client and server support them. * The RFC8709 ssh-ed25519 signature algorithm. It has been supported in OpenSSH since release 6.5. * The RFC5656 ECDSA algorithms: ecdsa-sha2-nistp256/384/521. These have been supported by OpenSSH since release 5.7. To check whether a server is using the weak ssh-rsa public key algorithm, for host authentication, try to connect to it after removing the ssh-rsa algorithm from ssh(1)'s allowed list: ssh -oHostKeyAlgorithms=-ssh-rsa user@host If the host key verification fails and no other supported host key types are available, the server software on that host should be upgraded. This release enables the UpdateHostKeys option by default to assist the client by automatically migrating to better algorithms. [1] "SHA-1 is a Shambles: First Chosen-Prefix Collision on SHA-1 and Application to the PGP Web of Trust" Leurent, G and Peyrin, T (2020) https://eprint.iacr.org/2020/014.pdf Security ======== * ssh-agent(1): fixed a double-free memory corruption that was introduced in OpenSSH 8.2 . We treat all such memory faults as potentially exploitable. This bug could be reached by an attacker with access to the agent socket. On modern operating systems where the OS can provide information about the user identity connected to a socket, OpenSSH ssh-agent and sshd limit agent socket access only to the originating user and root. Additional mitigation may be afforded by the system's malloc(3)/free(3) implementation, if it detects double-free conditions. The most likely scenario for exploitation is a user forwarding an agent either to an account shared with a malicious user or to a host with an attacker holding root access. * Portable sshd(8): Prevent excessively long username going to PAM. This is a mitigation for a buffer overflow in Solaris' PAM username handling (CVE-2020-14871), and is only enabled for Sun-derived PAM implementations. This is not a problem in sshd itself, it only prevents sshd from being used as a vector to attack Solaris' PAM. It does not prevent the bug in PAM from being exploited via some other PAM application. GHPR212 Potentially-incompatible changes ================================ This release includes a number of changes that may affect existing configurations: * ssh(1), sshd(8): this release changes the first-preference signature algorithm from ECDSA to ED25519. * ssh(1), sshd(8): set the TOS/DSCP specified in the configuration for interactive use prior to TCP connect. The connection phase of the SSH session is time-sensitive and often explicitly interactive. The ultimate interactive/bulk TOS/DSCP will be set after authentication completes. * ssh(1), sshd(8): remove the pre-standardization cipher rijndael-cbc@lysator.liu.se. It is an alias for aes256-cbc before it was standardized in RFC4253 (2006), has been deprecated and disabled by default since OpenSSH 7.2 (2016) and was only briefly documented in ssh.1 in 2001. * ssh(1), sshd(8): update/replace the experimental post-quantum hybrid key exchange method based on Streamlined NTRU Prime coupled with X25519. The previous sntrup4591761x25519-sha512@tinyssh.org method is replaced with sntrup761x25519-sha512@openssh.com. Per its designers, the sntrup4591761 algorithm was superseded almost two years ago by sntrup761. (note this both the updated method and the one that it replaced are disabled by default) * ssh(1): disable CheckHostIP by default. It provides insignificant benefits while making key rotation significantly more difficult, especially for hosts behind IP-based load-balancers. Changes since OpenSSH 8.4 ========================= New features ------------ * ssh(1): this release enables UpdateHostkeys by default subject to some conservative preconditions: - The key was matched in the UserKnownHostsFile (and not in the GlobalKnownHostsFile). - The same key does not exist under another name. - A certificate host key is not in use. - known_hosts contains no matching wildcard hostname pattern. - VerifyHostKeyDNS is not enabled. - The default UserKnownHostsFile is in use. We expect some of these conditions will be modified or relaxed in future. * ssh(1), sshd(8): add a new LogVerbose configuration directive for that allows forcing maximum debug logging by file/function/line pattern-lists. * ssh(1): when prompting the user to accept a new hostkey, display any other host names/addresses already associated with the key. * ssh(1): allow UserKnownHostsFile=none to indicate that no known_hosts file should be used to identify host keys. * ssh(1): add a ssh_config KnownHostsCommand option that allows the client to obtain known_hosts data from a command in addition to the usual files. * ssh(1): add a ssh_config PermitRemoteOpen option that allows the client to restrict the destination when RemoteForward is used with SOCKS. * ssh(1): for FIDO keys, if a signature operation fails with a "incorrect PIN" reason and no PIN was initially requested from the user, then request a PIN and retry the operation. This supports some biometric devices that fall back to requiring PIN when reading of the biometric failed, and devices that require PINs for all hosted credentials. * sshd(8): implement client address-based rate-limiting via new sshd_config(5) PerSourceMaxStartups and PerSourceNetBlockSize directives that provide more fine-grained control on a per-origin address basis than the global MaxStartups limit. Bugfixes -------- * ssh(1): Prefix keyboard interactive prompts with "(user@host)" to make it easier to determine which connection they are associated with in cases like scp -3, ProxyJump, etc. bz#3224 * sshd(8): fix sshd_config SetEnv directives located inside Match blocks. GHPR201 * ssh(1): when requesting a FIDO token touch on stderr, inform the user once the touch has been recorded. * ssh(1): prevent integer overflow when ridiculously large ConnectTimeout values are specified, capping the effective value (for most platforms) at 24 days. bz#3229 * ssh(1): consider the ECDSA key subtype when ordering host key algorithms in the client. * ssh(1), sshd(8): rename the PubkeyAcceptedKeyTypes keyword to PubkeyAcceptedAlgorithms. The previous name incorrectly suggested that it control allowed key algorithms, when this option actually specifies the signature algorithms that are accepted. The previous name remains available as an alias. bz#3253 * ssh(1), sshd(8): similarly, rename HostbasedKeyTypes (ssh) and HostbasedAcceptedKeyTypes (sshd) to HostbasedAcceptedAlgorithms. * sftp-server(8): add missing lsetstat@openssh.com documentation and advertisement in the server's SSH2_FXP_VERSION hello packet. * ssh(1), sshd(8): more strictly enforce KEX state-machine by banning packet types once they are received. Fixes memleak caused by duplicate SSH2_MSG_KEX_DH_GEX_REQUEST (oss-fuzz #30078). * sftp(1): allow the full range of UIDs/GIDs for chown/chgrp on 32bit platforms instead of being limited by LONG_MAX. bz#3206 * Minor man page fixes (capitalization, commas, etc.) bz#3223 * sftp(1): when doing an sftp recursive upload or download of a read-only directory, ensure that the directory is created with write and execute permissions in the interim so that the transfer can actually complete, then set the directory permission as the final step. bz#3222 * ssh-keygen(1): document the -Z, check the validity of its argument earlier and provide a better error message if it's not correct. bz#2879 * ssh(1): ignore comments at the end of config lines in ssh_config, similar to what we already do for sshd_config. bz#2320 * sshd_config(5): mention that DisableForwarding is valid in a sshd_config Match block. bz3239 * sftp(1): fix incorrect sorting of "ls -ltr" under some circumstances. bz3248. * ssh(1), sshd(8): fix potential integer truncation of (unlikely) timeout values. bz#3250 * ssh(1): make hostbased authentication send the signature algorithm in its SSH2_MSG_USERAUTH_REQUEST packets instead of the key type. This make HostbasedAcceptedAlgorithms do what it is supposed to - filter on signature algorithm and not key type. Portability ----------- * sshd(8): add a number of platform-specific syscalls to the Linux seccomp-bpf sandbox. bz#3232 bz#3260 * sshd(8): remove debug message from sigchld handler that could cause deadlock on some platforms. bz#3259 * Sync contrib/ssh-copy-id with upstream. * unittests: add a hostname function for systems that don't have it. Some systems don't have a hostname command (it's not required by POSIX). The do have uname -n (which is), but not all of those have it report the FQDN. Checksums: ========== - SHA1 (openssh-8.5.tar.gz) = 04cae43c389fb411227c01219e4eb46e3113f34e - SHA256 (openssh-8.5.tar.gz) = 5qB2CgzNG4io4DmChTjHgCWqRWvEOvCKJskLdJCz+SU= - SHA1 (openssh-8.5p1.tar.gz) = 72eadcbe313b07b1dd3b693e41d3cd56d354e24e - SHA256 (openssh-8.5p1.tar.gz) = 9S8/QdQpqpkY44zyAK8iXM3Y5m8FLaVyhwyJc3ZG7CU= Please note that the SHA256 signatures are base64 encoded and not hexadecimal (which is the default for most checksum tools). The PGP key used to sign the releases is available from the mirror sites: https://cdn.openbsd.org/pub/OpenBSD/OpenSSH/RELEASE_KEY.asc Please note that the OpenPGP key used to sign releases has been rotated for this release. The new key has been signed by the previous key to provide continuity. Reporting Bugs: =============== - Please read https://www.openssh.com/report.html Security bugs should be reported directly to openssh@openssh.com
2021-03-05 20:45:24 +03:00
char *pubkey_accepted_algos; /* Signature algos allowed for pubkey */
OpenSSH 8.2/8.2p1 (2020-02-14) OpenSSH 8.2 was released on 2020-02-14. It is available from the mirrors listed at https://www.openssh.com/. OpenSSH is a 100% complete SSH protocol 2.0 implementation and includes sftp client and server support. Once again, we would like to thank the OpenSSH community for their continued support of the project, especially those who contributed code or patches, reported bugs, tested snapshots or donated to the project. More information on donations may be found at: https://www.openssh.com/donations.html Future deprecation notice ========================= It is now possible[1] to perform chosen-prefix attacks against the SHA-1 hash algorithm for less than USD$50K. For this reason, we will be disabling the "ssh-rsa" public key signature algorithm that depends on SHA-1 by default in a near-future release. This algorithm is unfortunately still used widely despite the existence of better alternatives, being the only remaining public key signature algorithm specified by the original SSH RFCs. The better alternatives include: * The RFC8332 RSA SHA-2 signature algorithms rsa-sha2-256/512. These algorithms have the advantage of using the same key type as "ssh-rsa" but use the safe SHA-2 hash algorithms. These have been supported since OpenSSH 7.2 and are already used by default if the client and server support them. * The ssh-ed25519 signature algorithm. It has been supported in OpenSSH since release 6.5. * The RFC5656 ECDSA algorithms: ecdsa-sha2-nistp256/384/521. These have been supported by OpenSSH since release 5.7. To check whether a server is using the weak ssh-rsa public key algorithm for host authentication, try to connect to it after removing the ssh-rsa algorithm from ssh(1)'s allowed list: ssh -oHostKeyAlgorithms=-ssh-rsa user@host If the host key verification fails and no other supported host key types are available, the server software on that host should be upgraded. A future release of OpenSSH will enable UpdateHostKeys by default to allow the client to automatically migrate to better algorithms. Users may consider enabling this option manually. [1] "SHA-1 is a Shambles: First Chosen-Prefix Collision on SHA-1 and Application to the PGP Web of Trust" Leurent, G and Peyrin, T (2020) https://eprint.iacr.org/2020/014.pdf Security ======== * ssh(1), sshd(8), ssh-keygen(1): this release removes the "ssh-rsa" (RSA/SHA1) algorithm from those accepted for certificate signatures (i.e. the client and server CASignatureAlgorithms option) and will use the rsa-sha2-512 signature algorithm by default when the ssh-keygen(1) CA signs new certificates. Certificates are at special risk to the aforementioned SHA1 collision vulnerability as an attacker has effectively unlimited time in which to craft a collision that yields them a valid certificate, far more than the relatively brief LoginGraceTime window that they have to forge a host key signature. The OpenSSH certificate format includes a CA-specified (typically random) nonce value near the start of the certificate that should make exploitation of chosen-prefix collisions in this context challenging, as the attacker does not have full control over the prefix that actually gets signed. Nonetheless, SHA1 is now a demonstrably broken algorithm and futher improvements in attacks are highly likely. OpenSSH releases prior to 7.2 do not support the newer RSA/SHA2 algorithms and will refuse to accept certificates signed by an OpenSSH 8.2+ CA using RSA keys unless the unsafe algorithm is explicitly selected during signing ("ssh-keygen -t ssh-rsa"). Older clients/servers may use another CA key type such as ssh-ed25519 (supported since OpenSSH 6.5) or one of the ecdsa-sha2-nistp256/384/521 types (supported since OpenSSH 5.7) instead if they cannot be upgraded. Potentially-incompatible changes ================================ This release includes a number of changes that may affect existing configurations: * ssh(1), sshd(8): the above removal of "ssh-rsa" from the accepted CASignatureAlgorithms list. * ssh(1), sshd(8): this release removes diffie-hellman-group14-sha1 from the default key exchange proposal for both the client and server. * ssh-keygen(1): the command-line options related to the generation and screening of safe prime numbers used by the diffie-hellman-group-exchange-* key exchange algorithms have changed. Most options have been folded under the -O flag. * sshd(8): the sshd listener process title visible to ps(1) has changed to include information about the number of connections that are currently attempting authentication and the limits configured by MaxStartups. * ssh-sk-helper(8): this is a new binary. It is used by the FIDO/U2F support to provide address-space isolation for token middleware libraries (including the internal one). It needs to be installed in the expected path, typically under /usr/libexec or similar. Changes since OpenSSH 8.1 ========================= This release contains some significant new features. FIDO/U2F Support ---------------- This release adds support for FIDO/U2F hardware authenticators to OpenSSH. U2F/FIDO are open standards for inexpensive two-factor authentication hardware that are widely used for website authentication. In OpenSSH FIDO devices are supported by new public key types "ecdsa-sk" and "ed25519-sk", along with corresponding certificate types. ssh-keygen(1) may be used to generate a FIDO token-backed key, after which they may be used much like any other key type supported by OpenSSH, so long as the hardware token is attached when the keys are used. FIDO tokens also generally require the user explicitly authorise operations by touching or tapping them. Generating a FIDO key requires the token be attached, and will usually require the user tap the token to confirm the operation: $ ssh-keygen -t ecdsa-sk -f ~/.ssh/id_ecdsa_sk Generating public/private ecdsa-sk key pair. You may need to touch your security key to authorize key generation. Enter file in which to save the key (/home/djm/.ssh/id_ecdsa_sk): Enter passphrase (empty for no passphrase): Enter same passphrase again: Your identification has been saved in /home/djm/.ssh/id_ecdsa_sk Your public key has been saved in /home/djm/.ssh/id_ecdsa_sk.pub This will yield a public and private key-pair. The private key file should be useless to an attacker who does not have access to the physical token. After generation, this key may be used like any other supported key in OpenSSH and may be listed in authorized_keys, added to ssh-agent(1), etc. The only additional stipulation is that the FIDO token that the key belongs to must be attached when the key is used. FIDO tokens are most commonly connected via USB but may be attached via other means such as Bluetooth or NFC. In OpenSSH, communication with the token is managed via a middleware library, specified by the SecurityKeyProvider directive in ssh/sshd_config(5) or the $SSH_SK_PROVIDER environment variable for ssh-keygen(1) and ssh-add(1). The API for this middleware is documented in the sk-api.h and PROTOCOL.u2f files in the source distribution. OpenSSH includes a middleware ("SecurityKeyProvider=internal") with support for USB tokens. It is automatically enabled in OpenBSD and may be enabled in portable OpenSSH via the configure flag --with-security-key-builtin. If the internal middleware is enabled then it is automatically used by default. This internal middleware requires that libfido2 (https://github.com/Yubico/libfido2) and its dependencies be installed. We recommend that packagers of portable OpenSSH enable the built-in middleware, as it provides the lowest-friction experience for users. Note: FIDO/U2F tokens are required to implement the ECDSA-P256 "ecdsa-sk" key type, but hardware support for Ed25519 "ed25519-sk" is less common. Similarly, not all hardware tokens support some of the optional features such as resident keys. The protocol-level changes to support FIDO/U2F keys in SSH are documented in the PROTOCOL.u2f file in the OpenSSH source distribution. There are a number of supporting changes to this feature: * ssh-keygen(1): add a "no-touch-required" option when generating FIDO-hosted keys, that disables their default behaviour of requiring a physical touch/tap on the token during authentication. Note: not all tokens support disabling the touch requirement. * sshd(8): add a sshd_config PubkeyAuthOptions directive that collects miscellaneous public key authentication-related options for sshd(8). At present it supports only a single option "no-touch-required". This causes sshd to skip its default check for FIDO/U2F keys that the signature was authorised by a touch or press event on the token hardware. * ssh(1), sshd(8), ssh-keygen(1): add a "no-touch-required" option for authorized_keys and a similar extension for certificates. This option disables the default requirement that FIDO key signatures attest that the user touched their key to authorize them, mirroring the similar PubkeyAuthOptions sshd_config option. * ssh-keygen(1): add support for the writing the FIDO attestation information that is returned when new keys are generated via the "-O write-attestation=/path" option. FIDO attestation certificates may be used to verify that a FIDO key is hosted in trusted hardware. OpenSSH does not currently make use of this information, beyond optionally writing it to disk. FIDO2 resident keys ------------------- FIDO/U2F OpenSSH keys consist of two parts: a "key handle" part stored in the private key file on disk, and a per-device private key that is unique to each FIDO/U2F token and that cannot be exported from the token hardware. These are combined by the hardware at authentication time to derive the real key that is used to sign authentication challenges. For tokens that are required to move between computers, it can be cumbersome to have to move the private key file first. To avoid this requirement, tokens implementing the newer FIDO2 standard support "resident keys", where it is possible to effectively retrieve the key handle part of the key from the hardware. OpenSSH supports this feature, allowing resident keys to be generated using the ssh-keygen(1) "-O resident" flag. This will produce a public/private key pair as usual, but it will be possible to retrieve the private key part from the token later. This may be done using "ssh-keygen -K", which will download all available resident keys from the tokens attached to the host and write public/private key files for them. It is also possible to download and add resident keys directly to ssh-agent(1) without writing files to the file-system using "ssh-add -K". Resident keys are indexed on the token by the application string and user ID. By default, OpenSSH uses an application string of "ssh:" and an empty user ID. If multiple resident keys on a single token are desired then it may be necessary to override one or both of these defaults using the ssh-keygen(1) "-O application=" or "-O user=" options. Note: OpenSSH will only download and use resident keys whose application string begins with "ssh:" Storing both parts of a key on a FIDO token increases the likelihood of an attacker being able to use a stolen token device. For this reason, tokens should enforce PIN authentication before allowing download of keys, and users should set a PIN on their tokens before creating any resident keys. Other New Features ------------------ * sshd(8): add an Include sshd_config keyword that allows including additional configuration files via glob(3) patterns. bz2468 * ssh(1)/sshd(8): make the LE (low effort) DSCP code point available via the IPQoS directive; bz2986, * ssh(1): when AddKeysToAgent=yes is set and the key contains no comment, add the key to the agent with the key's path as the comment. bz2564 * ssh-keygen(1), ssh-agent(1): expose PKCS#11 key labels and X.509 subjects as key comments, rather than simply listing the PKCS#11 provider library path. PR138 * ssh-keygen(1): allow PEM export of DSA and ECDSA keys; bz3091 * ssh(1), sshd(8): make zlib compile-time optional, available via the Makefile.inc ZLIB flag on OpenBSD or via the --with-zlib configure option for OpenSSH portable. * sshd(8): when clients get denied by MaxStartups, send a notification prior to the SSH2 protocol banner according to RFC4253 section 4.2. * ssh(1), ssh-agent(1): when invoking the $SSH_ASKPASS prompt program, pass a hint to the program to describe the type of desired prompt. The possible values are "confirm" (indicating that a yes/no confirmation dialog with no text entry should be shown), "none" (to indicate an informational message only), or blank for the original ssh-askpass behaviour of requesting a password/phrase. * ssh(1): allow forwarding a different agent socket to the path specified by $SSH_AUTH_SOCK, by extending the existing ForwardAgent option to accepting an explicit path or the name of an environment variable in addition to yes/no. * ssh-keygen(1): add a new signature operations "find-principals" to look up the principal associated with a signature from an allowed- signers file. * sshd(8): expose the number of currently-authenticating connections along with the MaxStartups limit in the process title visible to "ps". Bugfixes -------- * sshd(8): make ClientAliveCountMax=0 have sensible semantics: it will now disable connection killing entirely rather than the current behaviour of instantly killing the connection after the first liveness test regardless of success. bz2627 * sshd(8): clarify order of AllowUsers / DenyUsers vs AllowGroups / DenyGroups in the sshd(8) manual page. bz1690 * sshd(8): better describe HashKnownHosts in the manual page. bz2560 * sshd(8): clarify that that permitopen=/PermitOpen do no name or address translation in the manual page. bz3099 * sshd(8): allow the UpdateHostKeys feature to function when multiple known_hosts files are in use. When updating host keys, ssh will now search subsequent known_hosts files, but will add updated host keys to the first specified file only. bz2738 * All: replace all calls to signal(2) with a wrapper around sigaction(2). This wrapper blocks all other signals during the handler preventing races between handlers, and sets SA_RESTART which should reduce the potential for short read/write operations. * sftp(1): fix a race condition in the SIGCHILD handler that could turn in to a kill(-1); bz3084 * sshd(8): fix a case where valid (but extremely large) SSH channel IDs were being incorrectly rejected. bz3098 * ssh(1): when checking host key fingerprints as answers to new hostkey prompts, ignore whitespace surrounding the fingerprint itself. * All: wait for file descriptors to be readable or writeable during non-blocking connect, not just readable. Prevents a timeout when the server doesn't immediately send a banner (e.g. multiplexers like sslh) * sshd_config(5): document the sntrup4591761x25519-sha512@tinyssh.org key exchange algorithm. PR#151
2020-02-27 03:21:35 +03:00
int pubkey_auth_options; /* -1 or mask of PUBKEYAUTH_* flags */
import 5.2 from ftp.openbsd.org
2009-06-08 02:19:00 +04:00
int kerberos_authentication; /* If true, permit Kerberos
* authentication. */
int kerberos_or_local_passwd; /* If true, permit kerberos
* and any other password
* authentication mechanism,
* such as SecurID or
* /etc/passwd */
int kerberos_ticket_cleanup; /* If true, destroy ticket
* file on logout. */
int kerberos_get_afs_token; /* If true, try to get AFS token if
* authenticated with Kerberos. */
int gss_authentication; /* If true, permit GSSAPI authentication */
int gss_cleanup_creds; /* If true, destroy cred cache on logout */
Changes since OpenSSH 6.8 ========================= This is primarily a bugfix release. Security -------- * ssh(1): when forwarding X11 connections with ForwardX11Trusted=no, connections made after ForwardX11Timeout expired could be permitted and no longer subject to XSECURITY restrictions because of an ineffective timeout check in ssh(1) coupled with "fail open" behaviour in the X11 server when clients attempted connections with expired credentials. This problem was reported by Jann Horn. * ssh-agent(1): fix weakness of agent locking (ssh-add -x) to password guessing by implementing an increasing failure delay, storing a salted hash of the password rather than the password itself and using a timing-safe comparison function for verifying unlock attempts. This problem was reported by Ryan Castellucci. New Features ------------ * ssh(1), sshd(8): promote chacha20-poly1305@openssh.com to be the default cipher * sshd(8): support admin-specified arguments to AuthorizedKeysCommand; bz#2081 * sshd(8): add AuthorizedPrincipalsCommand that allows retrieving authorized principals information from a subprocess rather than a file. * ssh(1), ssh-add(1): support PKCS#11 devices with external PIN entry devices bz#2240 * sshd(8): allow GSSAPI host credential check to be relaxed for multihomed hosts via GSSAPIStrictAcceptorCheck option; bz#928 * ssh-keygen(1): support "ssh-keygen -lF hostname" to search known_hosts and print key hashes rather than full keys. * ssh-agent(1): add -D flag to leave ssh-agent in foreground without enabling debug mode; bz#2381 Bugfixes -------- * ssh(1), sshd(8): deprecate legacy SSH2_MSG_KEX_DH_GEX_REQUEST_OLD message and do not try to use it against some 3rd-party SSH implementations that use it (older PuTTY, WinSCP). * Many fixes for problems caused by compile-time deactivation of SSH1 support (including bz#2369) * ssh(1), sshd(8): cap DH-GEX group size at 4Kbits for Cisco implementations as some would fail when attempting to use group sizes >4K; bz#2209 * ssh(1): fix out-of-bound read in EscapeChar configuration option parsing; bz#2396 * sshd(8): fix application of PermitTunnel, LoginGraceTime, AuthenticationMethods and StreamLocalBindMask options in Match blocks * ssh(1), sshd(8): improve disconnection message on TCP reset; bz#2257 * ssh(1): remove failed remote forwards established by muliplexing from the list of active forwards; bz#2363 * sshd(8): make parsing of authorized_keys "environment=" options independent of PermitUserEnv being enabled; bz#2329 * sshd(8): fix post-auth crash with permitopen=none; bz#2355 * ssh(1), ssh-add(1), ssh-keygen(1): allow new-format private keys to be encrypted with AEAD ciphers; bz#2366 * ssh(1): allow ListenAddress, Port and AddressFamily configuration options to appear in any order; bz#86 * sshd(8): check for and reject missing arguments for VersionAddendum and ForceCommand; bz#2281 * ssh(1), sshd(8): don't treat unknown certificate extensions as fatal; bz#2387 * ssh-keygen(1): make stdout and stderr output consistent; bz#2325 * ssh(1): mention missing DISPLAY environment in debug log when X11 forwarding requested; bz#1682 * sshd(8): correctly record login when UseLogin is set; bz#378 * sshd(8): Add some missing options to sshd -T output and fix output of VersionAddendum and HostCertificate. bz#2346 * Document and improve consistency of options that accept a "none" argument" TrustedUserCAKeys, RevokedKeys (bz#2382), AuthorizedPrincipalsFile (bz#2288) * ssh(1): include remote username in debug output; bz#2368 * sshd(8): avoid compatibility problem with some versions of Tera Term, which would crash when they received the hostkeys notification message (hostkeys-00@openssh.com) * sshd(8): mention ssh-keygen -E as useful when comparing legacy MD5 host key fingerprints; bz#2332 * ssh(1): clarify pseudo-terminal request behaviour and use make manual language consistent; bz#1716 * ssh(1): document that the TERM environment variable is not subject to SendEnv and AcceptEnv; bz#2386
2015-07-03 03:54:41 +03:00
int gss_strict_acceptor; /* If true, restrict the GSSAPI acceptor name */
import 5.2 from ftp.openbsd.org
2009-06-08 02:19:00 +04:00
int password_authentication; /* If true, permit password
* authentication. */
int kbd_interactive_authentication; /* If true, permit */
int permit_empty_passwd; /* If false, do not permit empty
* passwords. */
int permit_user_env; /* If true, read ~/.ssh/environment */
OpenSSH 8.4 was released on 2020-09-27. It is available from the mirrors listed at https://www.openssh.com/. OpenSSH is a 100% complete SSH protocol 2.0 implementation and includes sftp client and server support. Once again, we would like to thank the OpenSSH community for their continued support of the project, especially those who contributed code or patches, reported bugs, tested snapshots or donated to the project. More information on donations may be found at: https://www.openssh.com/donations.html Future deprecation notice ========================= It is now possible[1] to perform chosen-prefix attacks against the SHA-1 algorithm for less than USD$50K. For this reason, we will be disabling the "ssh-rsa" public key signature algorithm by default in a near-future release. This algorithm is unfortunately still used widely despite the existence of better alternatives, being the only remaining public key signature algorithm specified by the original SSH RFCs. The better alternatives include: * The RFC8332 RSA SHA-2 signature algorithms rsa-sha2-256/512. These algorithms have the advantage of using the same key type as "ssh-rsa" but use the safe SHA-2 hash algorithms. These have been supported since OpenSSH 7.2 and are already used by default if the client and server support them. * The ssh-ed25519 signature algorithm. It has been supported in OpenSSH since release 6.5. * The RFC5656 ECDSA algorithms: ecdsa-sha2-nistp256/384/521. These have been supported by OpenSSH since release 5.7. To check whether a server is using the weak ssh-rsa public key algorithm, for host authentication, try to connect to it after removing the ssh-rsa algorithm from ssh(1)'s allowed list: ssh -oHostKeyAlgorithms=-ssh-rsa user@host If the host key verification fails and no other supported host key types are available, the server software on that host should be upgraded. We intend to enable UpdateHostKeys by default in the next OpenSSH release. This will assist the client by automatically migrating to better algorithms. Users may consider enabling this option manually. [1] "SHA-1 is a Shambles: First Chosen-Prefix Collision on SHA-1 and Application to the PGP Web of Trust" Leurent, G and Peyrin, T (2020) https://eprint.iacr.org/2020/014.pdf Security ======== * ssh-agent(1): restrict ssh-agent from signing web challenges for FIDO/U2F keys. When signing messages in ssh-agent using a FIDO key that has an application string that does not start with "ssh:", ensure that the message being signed is one of the forms expected for the SSH protocol (currently public key authentication and sshsig signatures). This prevents ssh-agent forwarding on a host that has FIDO keys attached granting the ability for the remote side to sign challenges for web authentication using those keys too. Note that the converse case of web browsers signing SSH challenges is already precluded because no web RP can have the "ssh:" prefix in the application string that we require. * ssh-keygen(1): Enable FIDO 2.1 credProtect extension when generating a FIDO resident key. The recent FIDO 2.1 Client to Authenticator Protocol introduced a "credProtect" feature to better protect resident keys. We use this option to require a PIN prior to all operations that may retrieve a resident key from a FIDO token. Potentially-incompatible changes ================================ This release includes a number of changes that may affect existing configurations: * For FIDO/U2F support, OpenSSH recommends the use of libfido2 1.5.0 or greater. Older libraries have limited support at the expense of disabling particular features. These include resident keys, PIN- required keys and multiple attached tokens. * ssh-keygen(1): the format of the attestation information optionally recorded when a FIDO key is generated has changed. It now includes the authenticator data needed to validate attestation signatures. * The API between OpenSSH and the FIDO token middleware has changed and the SSH_SK_VERSION_MAJOR version has been incremented as a result. Third-party middleware libraries must support the current API version (7) to work with OpenSSH 8.4. * The portable OpenSSH distribution now requires automake to rebuild the configure script and supporting files. This is not required when simply building portable OpenSSH from a release tar file. Changes since OpenSSH 8.3 ========================= New features ------------ * ssh(1), ssh-keygen(1): support for FIDO keys that require a PIN for each use. These keys may be generated using ssh-keygen using a new "verify-required" option. When a PIN-required key is used, the user will be prompted for a PIN to complete the signature operation. * sshd(8): authorized_keys now supports a new "verify-required" option to require FIDO signatures assert that the token verified that the user was present before making the signature. The FIDO protocol supports multiple methods for user-verification, but currently OpenSSH only supports PIN verification. * sshd(8), ssh-keygen(1): add support for verifying FIDO webauthn signatures. Webauthn is a standard for using FIDO keys in web browsers. These signatures are a slightly different format to plain FIDO signatures and thus require explicit support. * ssh(1): allow some keywords to expand shell-style ${ENV} environment variables. The supported keywords are CertificateFile, ControlPath, IdentityAgent and IdentityFile, plus LocalForward and RemoteForward when used for Unix domain socket paths. bz#3140 * ssh(1), ssh-agent(1): allow some additional control over the use of ssh-askpass via a new $SSH_ASKPASS_REQUIRE environment variable, including forcibly enabling and disabling its use. bz#69 * ssh(1): allow ssh_config(5)'s AddKeysToAgent keyword accept a time limit for keys in addition to its current flag options. Time- limited keys will automatically be removed from ssh-agent after their expiry time has passed. * scp(1), sftp(1): allow the -A flag to explicitly enable agent forwarding in scp and sftp. The default remains to not forward an agent, even when ssh_config enables it. * ssh(1): add a '%k' TOKEN that expands to the effective HostKey of the destination. This allows, e.g., keeping host keys in individual files using "UserKnownHostsFile ~/.ssh/known_hosts.d/%k". bz#1654 * ssh(1): add %-TOKEN, environment variable and tilde expansion to the UserKnownHostsFile directive, allowing the path to be completed by the configuration (e.g. bz#1654) * ssh-keygen(1): allow "ssh-add -d -" to read keys to be deleted from stdin. bz#3180 * sshd(8): improve logging for MaxStartups connection throttling. sshd will now log when it starts and stops throttling and periodically while in this state. bz#3055 Bugfixes -------- * ssh(1), ssh-keygen(1): better support for multiple attached FIDO tokens. In cases where OpenSSH cannot unambiguously determine which token to direct a request to, the user is now required to select a token by touching it. In cases of operations that require a PIN to be verified, this avoids sending the wrong PIN to the wrong token and incrementing the token's PIN failure counter (tokens effectively erase their keys after too many PIN failures). * sshd(8): fix Include before Match in sshd_config; bz#3122 * ssh(1): close stdin/out/error when forking after authentication completes ("ssh -f ...") bz#3137 * ssh(1), sshd(8): limit the amount of channel input data buffered, avoiding peers that advertise large windows but are slow to read from causing high memory consumption. * ssh-agent(1): handle multiple requests sent in a single write() to the agent. * sshd(8): allow sshd_config longer than 256k * sshd(8): avoid spurious "Unable to load host key" message when sshd load a private key but no public counterpart * ssh(1): prefer the default hostkey algorithm list whenever we have a hostkey that matches its best-preference algorithm. * sshd(1): when ordering the hostkey algorithms to request from a server, prefer certificate types if the known_hosts files contain a key marked as a @cert-authority; bz#3157 * ssh(1): perform host key fingerprint comparisons for the "Are you sure you want to continue connecting (yes/no/[fingerprint])?" prompt with case sensitivity. * sshd(8): ensure that address/masklen mismatches in sshd_config yield fatal errors at daemon start time rather than later when they are evaluated. * ssh-keygen(1): ensure that certificate extensions are lexically sorted. Previously if the user specified a custom extension then the everything would be in order except the custom ones. bz#3198 * ssh(1): also compare username when checking for JumpHost loops. bz#3057 * ssh-keygen(1): preserve group/world read permission on known_hosts files across runs of "ssh-keygen -Rf /path". The old behaviour was to remove all rights for group/other. bz#3146 * ssh-keygen(1): Mention the [-a rounds] flag in the ssh-keygen manual page and usage(). * sshd(8): explicitly construct path to ~/.ssh/rc rather than relying on it being relative to the current directory, so that it can still be found if the shell startup changes its directory. bz#3185 * sshd(8): when redirecting sshd's log output to a file, undo this redirection after the session child process is forked(). Fixes missing log messages when using this feature under some circumstances. * sshd(8): start ClientAliveInterval bookkeeping before first pass through select() loop; fixed theoretical case where busy sshd may ignore timeouts from client. * ssh(1): only reset the ServerAliveInterval check when we receive traffic from the server and ignore traffic from a port forwarding client, preventing a client from keeping a connection alive when it should be terminated. bz#2265 * ssh-keygen(1): avoid spurious error message when ssh-keygen creates files outside ~/.ssh * sftp-client(1): fix off-by-one error that caused sftp downloads to make one more concurrent request that desired. This prevented using sftp(1) in unpipelined request/response mode, which is useful when debugging. bz#3054 * ssh(1), sshd(8): handle EINTR in waitfd() and timeout_connect() helpers. bz#3071 * ssh(1), ssh-keygen(1): defer creation of ~/.ssh until we attempt to write to it so we don't leave an empty .ssh directory when it's not needed. bz#3156 * ssh(1), sshd(8): fix multiplier when parsing time specifications when handling seconds after other units. bz#3171 Portability ----------- * sshd(8): always send any PAM account messages. If the PAM account stack returns any messages, always send them to the user and not just if the check succeeds. bz#2049 * Implement some backwards compatibility for libfido2 libraries older than 1.5.0. Note that use of an older library will result in the loss of certain features including resident key support, PIN support and support for multiple attached tokens. * configure fixes for XCode 12 * gnome-ssh-askpass3: ensure the "close" button is not focused by default for SSH_ASKPASS_PROMPT=none prompts. Avoids space/enter accidentally dismissing FIDO touch notifications. * gnome-ssh-askpass3: allow some control over textarea colour via $GNOME_SSH_ASKPASS_FG_COLOR and $GNOME_SSH_ASKPASS_BG_COLOR environment variables. * sshd(8): document another PAM spec problem in a frustrated comment * sshd(8): support NetBSD's utmpx.ut_ss address field. bz#960 * Add the ssh-sk-helper binary and its manpage to the RPM spec file * Detect the Frankenstein monster of Linux/X32 and allow the sandbox to function there. bz#3085
2020-12-04 21:40:04 +03:00
char *permit_user_env_allowlist; /* pattern-list of allowed env names */
import 5.2 from ftp.openbsd.org
2009-06-08 02:19:00 +04:00
int compression; /* If true, compression is allowed */
from openbsd
2013-03-29 18:52:38 +04:00
int allow_tcp_forwarding; /* One of FORWARD_* */
Changes since OpenSSH 6.6 ========================= Potentially-incompatible changes * sshd(8): The default set of ciphers and MACs has been altered to remove unsafe algorithms. In particular, CBC ciphers and arcfour* are disabled by default. The full set of algorithms remains available if configured explicitly via the Ciphers and MACs sshd_config options. * sshd(8): Support for tcpwrappers/libwrap has been removed. * OpenSSH 6.5 and 6.6 have a bug that causes ~0.2% of connections using the curve25519-sha256@libssh.org KEX exchange method to fail when connecting with something that implements the specification correctly. OpenSSH 6.7 disables this KEX method when speaking to one of the affected versions. New Features * Major internal refactoring to begin to make part of OpenSSH usable as a library. So far the wire parsing, key handling and KRL code has been refactored. Please note that we do not consider the API stable yet, nor do we offer the library in separable form. * ssh(1), sshd(8): Add support for Unix domain socket forwarding. A remote TCP port may be forwarded to a local Unix domain socket and vice versa or both ends may be a Unix domain socket. * ssh(1), ssh-keygen(1): Add support for SSHFP DNS records for ED25519 key types. * sftp(1): Allow resumption of interrupted uploads. * ssh(1): When rekeying, skip file/DNS lookups of the hostkey if it is the same as the one sent during initial key exchange; bz#2154 * sshd(8): Allow explicit ::1 and 127.0.0.1 forwarding bind addresses when GatewayPorts=no; allows client to choose address family; bz#2222 * sshd(8): Add a sshd_config PermitUserRC option to control whether ~/.ssh/rc is executed, mirroring the no-user-rc authorized_keys option; bz#2160 * ssh(1): Add a %C escape sequence for LocalCommand and ControlPath that expands to a unique identifer based on a hash of the tuple of (local host, remote user, hostname, port). Helps avoid exceeding miserly pathname limits for Unix domain sockets in multiplexing control paths; bz#2220 * sshd(8): Make the "Too many authentication failures" message include the user, source address, port and protocol in a format similar to the authentication success / failure messages; bz#2199 * Added unit and fuzz tests for refactored code. These are run automatically in portable OpenSSH via the "make tests" target. Bugfixes * sshd(8): Fix remote forwarding with the same listen port but different listen address. * ssh(1): Fix inverted test that caused PKCS#11 keys that were explicitly listed in ssh_config or on the commandline not to be preferred. * ssh-keygen(1): Fix bug in KRL generation: multiple consecutive revoked certificate serial number ranges could be serialised to an invalid format. Readers of a broken KRL caused by this bug will fail closed, so no should-have-been-revoked key will be accepted. * ssh(1): Reflect stdio-forward ("ssh -W host:port ...") failures in exit status. Previously we were always returning 0; bz#2255 * ssh(1), ssh-keygen(1): Make Ed25519 keys' title fit properly in the randomart border; bz#2247 * ssh-agent(1): Only cleanup agent socket in the main agent process and not in any subprocesses it may have started (e.g. forked askpass). Fixes agent sockets being zapped when askpass processes fatal(); bz#2236 * ssh-add(1): Make stdout line-buffered; saves partial output getting lost when ssh-add fatal()s part-way through (e.g. when listing keys from an agent that supports key types that ssh-add doesn't); bz#2234 * ssh-keygen(1): When hashing or removing hosts, don't choke on @revoked markers and don't remove @cert-authority markers; bz#2241 * ssh(1): Don't fatal when hostname canonicalisation fails and a ProxyCommand is in use; continue and allow the ProxyCommand to connect anyway (e.g. to a host with a name outside the DNS behind a bastion) * scp(1): When copying local->remote fails during read, don't send uninitialised heap to the remote end. * sftp(1): Fix fatal "el_insertstr failed" errors when tab-completing filenames with a single quote char somewhere in the string; bz#2238 * ssh-keyscan(1): Scan for Ed25519 keys by default. * ssh(1): When using VerifyHostKeyDNS with a DNSSEC resolver, down- convert any certificate keys to plain keys and attempt SSHFP resolution. Prevents a server from skipping SSHFP lookup and forcing a new-hostkey dialog by offering only certificate keys. * sshd(8): Avoid crash at exit via NULL pointer reference; bz#2225 * Fix some strict-alignment errors. Portable OpenSSH * Portable OpenSSH now supports building against libressl-portable. * Portable OpenSSH now requires openssl 0.9.8f or greater. Older versions are no longer supported. * In the OpenSSL version check, allow fix version upgrades (but not downgrades. Debian bug #748150. * sshd(8): On Cygwin, determine privilege separation user at runtime, since it may need to be a domain account. * sshd(8): Don't attempt to use vhangup on Linux. It doesn't work for non-root users, and for them it just messes up the tty settings. * Use CLOCK_BOOTTIME in preference to CLOCK_MONOTONIC when it is available. It considers time spent suspended, thereby ensuring timeouts (e.g. for expiring agent keys) fire correctly. bz#2228 * Add support for ed25519 to opensshd.init init script. * sftp-server(8): On platforms that support it, use prctl() to prevent sftp-server from accessing /proc/self/{mem,maps} Changes since OpenSSH 6.5 ========================= This is primarily a bugfix release. Security: * sshd(8): when using environment passing with a sshd_config(5) AcceptEnv pattern with a wildcard. OpenSSH prior to 6.6 could be tricked into accepting any enviornment variable that contains the characters before the wildcard character. New / changed features: * ssh(1), sshd(8): this release removes the J-PAKE authentication code. This code was experimental, never enabled and had been unmaintained for some time. * ssh(1): when processing Match blocks, skip 'exec' clauses other clauses predicates failed to match. * ssh(1): if hostname canonicalisation is enabled and results in the destination hostname being changed, then re-parse ssh_config(5) files using the new destination hostname. This gives 'Host' and 'Match' directives that use the expanded hostname a chance to be applied. Bugfixes: * ssh(1): avoid spurious "getsockname failed: Bad file descriptor" in ssh -W. bz#2200, debian#738692 * sshd(8): allow the shutdown(2) syscall in seccomp-bpf and systrace sandbox modes, as it is reachable if the connection is terminated during the pre-auth phase. * ssh(1), sshd(8): fix unsigned overflow that in SSH protocol 1 bignum parsing. Minimum key length checks render this bug unexploitable to compromise SSH 1 sessions. * sshd_config(5): clarify behaviour of a keyword that appears in multiple matching Match blocks. bz#2184 * ssh(1): avoid unnecessary hostname lookups when canonicalisation is disabled. bz#2205 * sshd(8): avoid sandbox violation crashes in GSSAPI code by caching the supported list of GSSAPI mechanism OIDs before entering the sandbox. bz#2107 * ssh(1): fix possible crashes in SOCKS4 parsing caused by assumption that the SOCKS username is nul-terminated. * ssh(1): fix regression for UsePrivilegedPort=yes when BindAddress is not specified. * ssh(1), sshd(8): fix memory leak in ECDSA signature verification. * ssh(1): fix matching of 'Host' directives in ssh_config(5) files to be case-insensitive again (regression in 6.5). Portable OpenSSH: * sshd(8): don't fatal if the FreeBSD Capsicum is offered by the system headers and libc but is not supported by the kernel. * Fix build using the HP-UX compiler. Changes since OpenSSH 6.4 ========================= This is a feature-focused release. New features: * ssh(1), sshd(8): Add support for key exchange using elliptic-curve Diffie Hellman in Daniel Bernstein's Curve25519. This key exchange method is the default when both the client and server support it. * ssh(1), sshd(8): Add support for Ed25519 as a public key type. Ed25519 is a elliptic curve signature scheme that offers better security than ECDSA and DSA and good performance. It may be used for both user and host keys. * Add a new private key format that uses a bcrypt KDF to better protect keys at rest. This format is used unconditionally for Ed25519 keys, but may be requested when generating or saving existing keys of other types via the -o ssh-keygen(1) option. We intend to make the new format the default in the near future. Details of the new format are in the PROTOCOL.key file. * ssh(1), sshd(8): Add a new transport cipher "chacha20-poly1305@openssh.com" that combines Daniel Bernstein's ChaCha20 stream cipher and Poly1305 MAC to build an authenticated encryption mode. Details are in the PROTOCOL.chacha20poly1305 file. * ssh(1), sshd(8): Refuse RSA keys from old proprietary clients and servers that use the obsolete RSA+MD5 signature scheme. It will still be possible to connect with these clients/servers but only DSA keys will be accepted, and OpenSSH will refuse connection entirely in a future release. * ssh(1), sshd(8): Refuse old proprietary clients and servers that use a weaker key exchange hash calculation. * ssh(1): Increase the size of the Diffie-Hellman groups requested for each symmetric key size. New values from NIST Special Publication 800-57 with the upper limit specified by RFC4419. * ssh(1), ssh-agent(1): Support PKCS#11 tokens that only provide X.509 certs instead of raw public keys (requested as bz#1908). * ssh(1): Add a ssh_config(5) "Match" keyword that allows conditional configuration to be applied by matching on hostname, user and result of arbitrary commands. * ssh(1): Add support for client-side hostname canonicalisation using a set of DNS suffixes and rules in ssh_config(5). This allows unqualified names to be canonicalised to fully-qualified domain names to eliminate ambiguity when looking up keys in known_hosts or checking host certificate names. * sftp-server(8): Add the ability to whitelist and/or blacklist sftp protocol requests by name. * sftp-server(8): Add a sftp "fsync@openssh.com" to support calling fsync(2) on an open file handle. * sshd(8): Add a ssh_config(5) PermitTTY to disallow TTY allocation, mirroring the longstanding no-pty authorized_keys option. * ssh(1): Add a ssh_config ProxyUseFDPass option that supports the use of ProxyCommands that establish a connection and then pass a connected file descriptor back to ssh(1). This allows the ProxyCommand to exit rather than staying around to transfer data. Bugfixes: * ssh(1), sshd(8): Fix potential stack exhaustion caused by nested certificates. * ssh(1): bz#1211: make BindAddress work with UsePrivilegedPort. * sftp(1): bz#2137: fix the progress meter for resumed transfer. * ssh-add(1): bz#2187: do not request smartcard PIN when removing keys from ssh-agent. * sshd(8): bz#2139: fix re-exec fallback when original sshd binary cannot be executed. * ssh-keygen(1): Make relative-specified certificate expiry times relative to current time and not the validity start time. * sshd(8): bz#2161: fix AuthorizedKeysCommand inside a Match block. * sftp(1): bz#2129: symlinking a file would incorrectly canonicalise the target path. * ssh-agent(1): bz#2175: fix a use-after-free in the PKCS#11 agent helper executable. * sshd(8): Improve logging of sessions to include the user name, remote host and port, the session type (shell, command, etc.) and allocated TTY (if any). * sshd(8): bz#1297: tell the client (via a debug message) when their preferred listen address has been overridden by the server's GatewayPorts setting. * sshd(8): bz#2162: include report port in bad protocol banner message. * sftp(1): bz#2163: fix memory leak in error path in do_readdir(). * sftp(1): bz#2171: don't leak file descriptor on error. * sshd(8): Include the local address and port in "Connection from ..." message (only shown at loglevel>=verbose). Portable OpenSSH: * Please note that this is the last version of Portable OpenSSH that will support versions of OpenSSL prior to 0.9.6. Support (i.e. SSH_OLD_EVP) will be removed following the 6.5p1 release. * Portable OpenSSH will attempt compile and link as a Position Independent Executable on Linux, OS X and OpenBSD on recent gcc- like compilers. Other platforms and older/other compilers may request this using the --with-pie configure flag. * A number of other toolchain-related hardening options are used automatically if available, including -ftrapv to abort on signed integer overflow and options to write-protect dynamic linking information. The use of these options may be disabled using the --without-hardening configure flag. * If the toolchain supports it, one of the -fstack-protector-strong, -fstack-protector-all or -fstack-protector compilation flag are used to add guards to mitigate attacks based on stack overflows. The use of these options may be disabled using the --without-stackprotect configure option. * sshd(8): Add support for pre-authentication sandboxing using the Capsicum API introduced in FreeBSD 10. * Switch to a ChaCha20-based arc4random() PRNG for platforms that do not provide their own. * sshd(8): bz#2156: restore Linux oom_adj setting when handling SIGHUP to maintain behaviour over retart. * sshd(8): bz#2032: use local username in krb5_kuserok check rather than full client name which may be of form user@REALM. * ssh(1), sshd(8): Test for both the presence of ECC NID numbers in OpenSSL and that they actually work. Fedora (at least) has NID_secp521r1 that doesn't work. * bz#2173: use pkg-config --libs to include correct -L location for libedit.
2014-10-19 20:28:33 +04:00
int allow_streamlocal_forwarding; /* One of FORWARD_* */
import 5.2 from ftp.openbsd.org
2009-06-08 02:19:00 +04:00
int allow_agent_forwarding;
Import OpenSSH-7.4 OpenSSH 7.4 has just been released. It will be available from the mirrors listed at http://www.openssh.com/ shortly. OpenSSH is a 100% complete SSH protocol 2.0 implementation and includes sftp client and server support. OpenSSH also includes transitional support for the legacy SSH 1.3 and 1.5 protocols that may be enabled at compile-time. Once again, we would like to thank the OpenSSH community for their continued support of the project, especially those who contributed code or patches, reported bugs, tested snapshots or donated to the project. More information on donations may be found at: http://www.openssh.com/donations.html Future deprecation notice ========================= We plan on retiring more legacy cryptography in future releases, specifically: * In approximately August 2017, removing remaining support for the SSH v.1 protocol (client-only and currently compile-time disabled). * In the same release, removing support for Blowfish and RC4 ciphers and the RIPE-MD160 HMAC. (These are currently run-time disabled). * Refusing all RSA keys smaller than 1024 bits (the current minimum is 768 bits) * The next release of OpenSSH will remove support for running sshd(8) with privilege separation disabled. * The next release of portable OpenSSH will remove support for OpenSSL version prior to 1.0.1. This list reflects our current intentions, but please check the final release notes for future releases. Potentially-incompatible changes ================================ This release includes a number of changes that may affect existing configurations: * This release removes server support for the SSH v.1 protocol. * ssh(1): Remove 3des-cbc from the client's default proposal. 64-bit block ciphers are not safe in 2016 and we don't want to wait until attacks like SWEET32 are extended to SSH. As 3des-cbc was the only mandatory cipher in the SSH RFCs, this may cause problems connecting to older devices using the default configuration, but it's highly likely that such devices already need explicit configuration for key exchange and hostkey algorithms already anyway. * sshd(8): Remove support for pre-authentication compression. Doing compression early in the protocol probably seemed reasonable in the 1990s, but today it's clearly a bad idea in terms of both cryptography (cf. multiple compression oracle attacks in TLS) and attack surface. Pre-auth compression support has been disabled by default for >10 years. Support remains in the client. * ssh-agent will refuse to load PKCS#11 modules outside a whitelist of trusted paths by default. The path whitelist may be specified at run-time. * sshd(8): When a forced-command appears in both a certificate and an authorized keys/principals command= restriction, sshd will now refuse to accept the certificate unless they are identical. The previous (documented) behaviour of having the certificate forced-command override the other could be a bit confusing and error-prone. * sshd(8): Remove the UseLogin configuration directive and support for having /bin/login manage login sessions.
2016-12-25 03:00:13 +03:00
int disable_forwarding;
import 5.2 from ftp.openbsd.org
2009-06-08 02:19:00 +04:00
u_int num_allow_users;
OpenSSH 7.7 was released on 2018-04-02. It is available from the mirrors listed at http://www.openssh.com/ shortly. OpenSSH is a 100% complete SSH protocol 2.0 implementation and includes sftp client and server support. Once again, we would like to thank the OpenSSH community for their continued support of the project, especially those who contributed code or patches, reported bugs, tested snapshots or donated to the project. More information on donations may be found at: http://www.openssh.com/donations.html Potentially-incompatible changes ================================ This release includes a number of changes that may affect existing configurations: * ssh(1)/sshd(8): Drop compatibility support for some very old SSH implementations, including ssh.com <=2.* and OpenSSH <= 3.*. These versions were all released in or before 2001 and predate the final SSH RFCs. The support in question isn't necessary for RFC-compliant SSH implementations. Changes since OpenSSH 7.6 ========================= This is primarily a bugfix release. New Features ------------ * All: Add experimental support for PQC XMSS keys (Extended Hash- Based Signatures) based on the algorithm described in https://tools.ietf.org/html/draft-irtf-cfrg-xmss-hash-based-signatures-12 The XMSS signature code is experimental and not compiled in by default. * sshd(8): Add a "rdomain" criteria for the sshd_config Match keyword to allow conditional configuration that depends on which routing domain a connection was received on (currently supported on OpenBSD and Linux). * sshd_config(5): Add an optional rdomain qualifier to the ListenAddress directive to allow listening on different routing domains. This is supported only on OpenBSD and Linux at present. * sshd_config(5): Add RDomain directive to allow the authenticated session to be placed in an explicit routing domain. This is only supported on OpenBSD at present. * sshd(8): Add "expiry-time" option for authorized_keys files to allow for expiring keys. * ssh(1): Add a BindInterface option to allow binding the outgoing connection to an interface's address (basically a more usable BindAddress) * ssh(1): Expose device allocated for tun/tap forwarding via a new %T expansion for LocalCommand. This allows LocalCommand to be used to prepare the interface. * sshd(8): Expose the device allocated for tun/tap forwarding via a new SSH_TUNNEL environment variable. This allows automatic setup of the interface and surrounding network configuration automatically on the server. * ssh(1)/scp(1)/sftp(1): Add URI support to ssh, sftp and scp, e.g. ssh://user@host or sftp://user@host/path. Additional connection parameters described in draft-ietf-secsh-scp-sftp-ssh-uri-04 are not implemented since the ssh fingerprint format in the draft uses the deprecated MD5 hash with no way to specify the any other algorithm. * ssh-keygen(1): Allow certificate validity intervals that specify only a start or stop time (instead of both or neither). * sftp(1): Allow "cd" and "lcd" commands with no explicit path argument. lcd will change to the local user's home directory as usual. cd will change to the starting directory for session (because the protocol offers no way to obtain the remote user's home directory). bz#2760 * sshd(8): When doing a config test with sshd -T, only require the attributes that are actually used in Match criteria rather than (an incomplete list of) all criteria. Bugfixes -------- * ssh(1)/sshd(8): More strictly check signature types during key exchange against what was negotiated. Prevents downgrade of RSA signatures made with SHA-256/512 to SHA-1. * sshd(8): Fix support for client that advertise a protocol version of "1.99" (indicating that they are prepared to accept both SSHv1 and SSHv2). This was broken in OpenSSH 7.6 during the removal of SSHv1 support. bz#2810 * ssh(1): Warn when the agent returns a ssh-rsa (SHA1) signature when a rsa-sha2-256/512 signature was requested. This condition is possible when an old or non-OpenSSH agent is in use. bz#2799 * ssh-agent(1): Fix regression introduced in 7.6 that caused ssh-agent to fatally exit if presented an invalid signature request message. * sshd_config(5): Accept yes/no flag options case-insensitively, as has been the case in ssh_config(5) for a long time. bz#2664 * ssh(1): Improve error reporting for failures during connection. Under some circumstances misleading errors were being shown. bz#2814 * ssh-keyscan(1): Add -D option to allow printing of results directly in SSHFP format. bz#2821 * regress tests: fix PuTTY interop test broken in last release's SSHv1 removal. bz#2823 * ssh(1): Compatibility fix for some servers that erroneously drop the connection when the IUTF8 (RFC8160) option is sent. * scp(1): Disable RemoteCommand and RequestTTY in the ssh session started by scp (sftp was already doing this.) * ssh-keygen(1): Refuse to create a certificate with an unusable number of principals. * ssh-keygen(1): Fatally exit if ssh-keygen is unable to write all the public key during key generation. Previously it would silently ignore errors writing the comment and terminating newline. * ssh(1): Do not modify hostname arguments that are addresses by automatically forcing them to lower-case. Instead canonicalise them to resolve ambiguities (e.g. ::0001 => ::1) before they are matched against known_hosts. bz#2763 * ssh(1): Don't accept junk after "yes" or "no" responses to hostkey prompts. bz#2803 * sftp(1): Have sftp print a warning about shell cleanliness when decoding the first packet fails, which is usually caused by shells polluting stdout of non-interactive startups. bz#2800 * ssh(1)/sshd(8): Switch timers in packet code from using wall-clock time to monotonic time, allowing the packet layer to better function over a clock step and avoiding possible integer overflows during steps. * Numerous manual page fixes and improvements. Portability ----------- * sshd(8): Correctly detect MIPS ABI in use at configure time. Fixes sandbox violations on some environments. * sshd(8): Remove UNICOS support. The hardware and software are literal museum pieces and support in sshd is too intrusive to justify maintaining. * All: Build and link with "retpoline" flags when available to mitigate the "branch target injection" style (variant 2) of the Spectre branch-prediction vulnerability. * All: Add auto-generated dependency information to Makefile. * Numerous fixed to the RPM spec files. Checksums: ========== - SHA1 (openssh-7.7.tar.gz) = 24812e05fa233014c847c7775748316e7f8a836c - SHA256 (openssh-7.7.tar.gz) = T4ua1L/vgAYqwB0muRahvnm5ZUr3PLY9nPljaG8egvo= - SHA1 (openssh-7.7p1.tar.gz) = 446fe9ed171f289f0d62197dffdbfdaaf21c49f2 - SHA256 (openssh-7.7p1.tar.gz) = 1zvn5oTpnvzQJL4Vowv/y+QbASsvezyQhK7WIXdea48= Please note that the SHA256 signatures are base64 encoded and not hexadecimal (which is the default for most checksum tools). The PGP key used to sign the releases is available as RELEASE_KEY.asc from the mirror sites. Reporting Bugs: =============== - Please read http://www.openssh.com/report.html Security bugs should be reported directly to openssh@openssh.com
2018-04-06 21:56:05 +03:00
char **allow_users;
import 5.2 from ftp.openbsd.org
2009-06-08 02:19:00 +04:00
u_int num_deny_users;
OpenSSH 7.7 was released on 2018-04-02. It is available from the mirrors listed at http://www.openssh.com/ shortly. OpenSSH is a 100% complete SSH protocol 2.0 implementation and includes sftp client and server support. Once again, we would like to thank the OpenSSH community for their continued support of the project, especially those who contributed code or patches, reported bugs, tested snapshots or donated to the project. More information on donations may be found at: http://www.openssh.com/donations.html Potentially-incompatible changes ================================ This release includes a number of changes that may affect existing configurations: * ssh(1)/sshd(8): Drop compatibility support for some very old SSH implementations, including ssh.com <=2.* and OpenSSH <= 3.*. These versions were all released in or before 2001 and predate the final SSH RFCs. The support in question isn't necessary for RFC-compliant SSH implementations. Changes since OpenSSH 7.6 ========================= This is primarily a bugfix release. New Features ------------ * All: Add experimental support for PQC XMSS keys (Extended Hash- Based Signatures) based on the algorithm described in https://tools.ietf.org/html/draft-irtf-cfrg-xmss-hash-based-signatures-12 The XMSS signature code is experimental and not compiled in by default. * sshd(8): Add a "rdomain" criteria for the sshd_config Match keyword to allow conditional configuration that depends on which routing domain a connection was received on (currently supported on OpenBSD and Linux). * sshd_config(5): Add an optional rdomain qualifier to the ListenAddress directive to allow listening on different routing domains. This is supported only on OpenBSD and Linux at present. * sshd_config(5): Add RDomain directive to allow the authenticated session to be placed in an explicit routing domain. This is only supported on OpenBSD at present. * sshd(8): Add "expiry-time" option for authorized_keys files to allow for expiring keys. * ssh(1): Add a BindInterface option to allow binding the outgoing connection to an interface's address (basically a more usable BindAddress) * ssh(1): Expose device allocated for tun/tap forwarding via a new %T expansion for LocalCommand. This allows LocalCommand to be used to prepare the interface. * sshd(8): Expose the device allocated for tun/tap forwarding via a new SSH_TUNNEL environment variable. This allows automatic setup of the interface and surrounding network configuration automatically on the server. * ssh(1)/scp(1)/sftp(1): Add URI support to ssh, sftp and scp, e.g. ssh://user@host or sftp://user@host/path. Additional connection parameters described in draft-ietf-secsh-scp-sftp-ssh-uri-04 are not implemented since the ssh fingerprint format in the draft uses the deprecated MD5 hash with no way to specify the any other algorithm. * ssh-keygen(1): Allow certificate validity intervals that specify only a start or stop time (instead of both or neither). * sftp(1): Allow "cd" and "lcd" commands with no explicit path argument. lcd will change to the local user's home directory as usual. cd will change to the starting directory for session (because the protocol offers no way to obtain the remote user's home directory). bz#2760 * sshd(8): When doing a config test with sshd -T, only require the attributes that are actually used in Match criteria rather than (an incomplete list of) all criteria. Bugfixes -------- * ssh(1)/sshd(8): More strictly check signature types during key exchange against what was negotiated. Prevents downgrade of RSA signatures made with SHA-256/512 to SHA-1. * sshd(8): Fix support for client that advertise a protocol version of "1.99" (indicating that they are prepared to accept both SSHv1 and SSHv2). This was broken in OpenSSH 7.6 during the removal of SSHv1 support. bz#2810 * ssh(1): Warn when the agent returns a ssh-rsa (SHA1) signature when a rsa-sha2-256/512 signature was requested. This condition is possible when an old or non-OpenSSH agent is in use. bz#2799 * ssh-agent(1): Fix regression introduced in 7.6 that caused ssh-agent to fatally exit if presented an invalid signature request message. * sshd_config(5): Accept yes/no flag options case-insensitively, as has been the case in ssh_config(5) for a long time. bz#2664 * ssh(1): Improve error reporting for failures during connection. Under some circumstances misleading errors were being shown. bz#2814 * ssh-keyscan(1): Add -D option to allow printing of results directly in SSHFP format. bz#2821 * regress tests: fix PuTTY interop test broken in last release's SSHv1 removal. bz#2823 * ssh(1): Compatibility fix for some servers that erroneously drop the connection when the IUTF8 (RFC8160) option is sent. * scp(1): Disable RemoteCommand and RequestTTY in the ssh session started by scp (sftp was already doing this.) * ssh-keygen(1): Refuse to create a certificate with an unusable number of principals. * ssh-keygen(1): Fatally exit if ssh-keygen is unable to write all the public key during key generation. Previously it would silently ignore errors writing the comment and terminating newline. * ssh(1): Do not modify hostname arguments that are addresses by automatically forcing them to lower-case. Instead canonicalise them to resolve ambiguities (e.g. ::0001 => ::1) before they are matched against known_hosts. bz#2763 * ssh(1): Don't accept junk after "yes" or "no" responses to hostkey prompts. bz#2803 * sftp(1): Have sftp print a warning about shell cleanliness when decoding the first packet fails, which is usually caused by shells polluting stdout of non-interactive startups. bz#2800 * ssh(1)/sshd(8): Switch timers in packet code from using wall-clock time to monotonic time, allowing the packet layer to better function over a clock step and avoiding possible integer overflows during steps. * Numerous manual page fixes and improvements. Portability ----------- * sshd(8): Correctly detect MIPS ABI in use at configure time. Fixes sandbox violations on some environments. * sshd(8): Remove UNICOS support. The hardware and software are literal museum pieces and support in sshd is too intrusive to justify maintaining. * All: Build and link with "retpoline" flags when available to mitigate the "branch target injection" style (variant 2) of the Spectre branch-prediction vulnerability. * All: Add auto-generated dependency information to Makefile. * Numerous fixed to the RPM spec files. Checksums: ========== - SHA1 (openssh-7.7.tar.gz) = 24812e05fa233014c847c7775748316e7f8a836c - SHA256 (openssh-7.7.tar.gz) = T4ua1L/vgAYqwB0muRahvnm5ZUr3PLY9nPljaG8egvo= - SHA1 (openssh-7.7p1.tar.gz) = 446fe9ed171f289f0d62197dffdbfdaaf21c49f2 - SHA256 (openssh-7.7p1.tar.gz) = 1zvn5oTpnvzQJL4Vowv/y+QbASsvezyQhK7WIXdea48= Please note that the SHA256 signatures are base64 encoded and not hexadecimal (which is the default for most checksum tools). The PGP key used to sign the releases is available as RELEASE_KEY.asc from the mirror sites. Reporting Bugs: =============== - Please read http://www.openssh.com/report.html Security bugs should be reported directly to openssh@openssh.com
2018-04-06 21:56:05 +03:00
char **deny_users;
import 5.2 from ftp.openbsd.org
2009-06-08 02:19:00 +04:00
u_int num_allow_groups;
OpenSSH 7.7 was released on 2018-04-02. It is available from the mirrors listed at http://www.openssh.com/ shortly. OpenSSH is a 100% complete SSH protocol 2.0 implementation and includes sftp client and server support. Once again, we would like to thank the OpenSSH community for their continued support of the project, especially those who contributed code or patches, reported bugs, tested snapshots or donated to the project. More information on donations may be found at: http://www.openssh.com/donations.html Potentially-incompatible changes ================================ This release includes a number of changes that may affect existing configurations: * ssh(1)/sshd(8): Drop compatibility support for some very old SSH implementations, including ssh.com <=2.* and OpenSSH <= 3.*. These versions were all released in or before 2001 and predate the final SSH RFCs. The support in question isn't necessary for RFC-compliant SSH implementations. Changes since OpenSSH 7.6 ========================= This is primarily a bugfix release. New Features ------------ * All: Add experimental support for PQC XMSS keys (Extended Hash- Based Signatures) based on the algorithm described in https://tools.ietf.org/html/draft-irtf-cfrg-xmss-hash-based-signatures-12 The XMSS signature code is experimental and not compiled in by default. * sshd(8): Add a "rdomain" criteria for the sshd_config Match keyword to allow conditional configuration that depends on which routing domain a connection was received on (currently supported on OpenBSD and Linux). * sshd_config(5): Add an optional rdomain qualifier to the ListenAddress directive to allow listening on different routing domains. This is supported only on OpenBSD and Linux at present. * sshd_config(5): Add RDomain directive to allow the authenticated session to be placed in an explicit routing domain. This is only supported on OpenBSD at present. * sshd(8): Add "expiry-time" option for authorized_keys files to allow for expiring keys. * ssh(1): Add a BindInterface option to allow binding the outgoing connection to an interface's address (basically a more usable BindAddress) * ssh(1): Expose device allocated for tun/tap forwarding via a new %T expansion for LocalCommand. This allows LocalCommand to be used to prepare the interface. * sshd(8): Expose the device allocated for tun/tap forwarding via a new SSH_TUNNEL environment variable. This allows automatic setup of the interface and surrounding network configuration automatically on the server. * ssh(1)/scp(1)/sftp(1): Add URI support to ssh, sftp and scp, e.g. ssh://user@host or sftp://user@host/path. Additional connection parameters described in draft-ietf-secsh-scp-sftp-ssh-uri-04 are not implemented since the ssh fingerprint format in the draft uses the deprecated MD5 hash with no way to specify the any other algorithm. * ssh-keygen(1): Allow certificate validity intervals that specify only a start or stop time (instead of both or neither). * sftp(1): Allow "cd" and "lcd" commands with no explicit path argument. lcd will change to the local user's home directory as usual. cd will change to the starting directory for session (because the protocol offers no way to obtain the remote user's home directory). bz#2760 * sshd(8): When doing a config test with sshd -T, only require the attributes that are actually used in Match criteria rather than (an incomplete list of) all criteria. Bugfixes -------- * ssh(1)/sshd(8): More strictly check signature types during key exchange against what was negotiated. Prevents downgrade of RSA signatures made with SHA-256/512 to SHA-1. * sshd(8): Fix support for client that advertise a protocol version of "1.99" (indicating that they are prepared to accept both SSHv1 and SSHv2). This was broken in OpenSSH 7.6 during the removal of SSHv1 support. bz#2810 * ssh(1): Warn when the agent returns a ssh-rsa (SHA1) signature when a rsa-sha2-256/512 signature was requested. This condition is possible when an old or non-OpenSSH agent is in use. bz#2799 * ssh-agent(1): Fix regression introduced in 7.6 that caused ssh-agent to fatally exit if presented an invalid signature request message. * sshd_config(5): Accept yes/no flag options case-insensitively, as has been the case in ssh_config(5) for a long time. bz#2664 * ssh(1): Improve error reporting for failures during connection. Under some circumstances misleading errors were being shown. bz#2814 * ssh-keyscan(1): Add -D option to allow printing of results directly in SSHFP format. bz#2821 * regress tests: fix PuTTY interop test broken in last release's SSHv1 removal. bz#2823 * ssh(1): Compatibility fix for some servers that erroneously drop the connection when the IUTF8 (RFC8160) option is sent. * scp(1): Disable RemoteCommand and RequestTTY in the ssh session started by scp (sftp was already doing this.) * ssh-keygen(1): Refuse to create a certificate with an unusable number of principals. * ssh-keygen(1): Fatally exit if ssh-keygen is unable to write all the public key during key generation. Previously it would silently ignore errors writing the comment and terminating newline. * ssh(1): Do not modify hostname arguments that are addresses by automatically forcing them to lower-case. Instead canonicalise them to resolve ambiguities (e.g. ::0001 => ::1) before they are matched against known_hosts. bz#2763 * ssh(1): Don't accept junk after "yes" or "no" responses to hostkey prompts. bz#2803 * sftp(1): Have sftp print a warning about shell cleanliness when decoding the first packet fails, which is usually caused by shells polluting stdout of non-interactive startups. bz#2800 * ssh(1)/sshd(8): Switch timers in packet code from using wall-clock time to monotonic time, allowing the packet layer to better function over a clock step and avoiding possible integer overflows during steps. * Numerous manual page fixes and improvements. Portability ----------- * sshd(8): Correctly detect MIPS ABI in use at configure time. Fixes sandbox violations on some environments. * sshd(8): Remove UNICOS support. The hardware and software are literal museum pieces and support in sshd is too intrusive to justify maintaining. * All: Build and link with "retpoline" flags when available to mitigate the "branch target injection" style (variant 2) of the Spectre branch-prediction vulnerability. * All: Add auto-generated dependency information to Makefile. * Numerous fixed to the RPM spec files. Checksums: ========== - SHA1 (openssh-7.7.tar.gz) = 24812e05fa233014c847c7775748316e7f8a836c - SHA256 (openssh-7.7.tar.gz) = T4ua1L/vgAYqwB0muRahvnm5ZUr3PLY9nPljaG8egvo= - SHA1 (openssh-7.7p1.tar.gz) = 446fe9ed171f289f0d62197dffdbfdaaf21c49f2 - SHA256 (openssh-7.7p1.tar.gz) = 1zvn5oTpnvzQJL4Vowv/y+QbASsvezyQhK7WIXdea48= Please note that the SHA256 signatures are base64 encoded and not hexadecimal (which is the default for most checksum tools). The PGP key used to sign the releases is available as RELEASE_KEY.asc from the mirror sites. Reporting Bugs: =============== - Please read http://www.openssh.com/report.html Security bugs should be reported directly to openssh@openssh.com
2018-04-06 21:56:05 +03:00
char **allow_groups;
import 5.2 from ftp.openbsd.org
2009-06-08 02:19:00 +04:00
u_int num_deny_groups;
OpenSSH 7.7 was released on 2018-04-02. It is available from the mirrors listed at http://www.openssh.com/ shortly. OpenSSH is a 100% complete SSH protocol 2.0 implementation and includes sftp client and server support. Once again, we would like to thank the OpenSSH community for their continued support of the project, especially those who contributed code or patches, reported bugs, tested snapshots or donated to the project. More information on donations may be found at: http://www.openssh.com/donations.html Potentially-incompatible changes ================================ This release includes a number of changes that may affect existing configurations: * ssh(1)/sshd(8): Drop compatibility support for some very old SSH implementations, including ssh.com <=2.* and OpenSSH <= 3.*. These versions were all released in or before 2001 and predate the final SSH RFCs. The support in question isn't necessary for RFC-compliant SSH implementations. Changes since OpenSSH 7.6 ========================= This is primarily a bugfix release. New Features ------------ * All: Add experimental support for PQC XMSS keys (Extended Hash- Based Signatures) based on the algorithm described in https://tools.ietf.org/html/draft-irtf-cfrg-xmss-hash-based-signatures-12 The XMSS signature code is experimental and not compiled in by default. * sshd(8): Add a "rdomain" criteria for the sshd_config Match keyword to allow conditional configuration that depends on which routing domain a connection was received on (currently supported on OpenBSD and Linux). * sshd_config(5): Add an optional rdomain qualifier to the ListenAddress directive to allow listening on different routing domains. This is supported only on OpenBSD and Linux at present. * sshd_config(5): Add RDomain directive to allow the authenticated session to be placed in an explicit routing domain. This is only supported on OpenBSD at present. * sshd(8): Add "expiry-time" option for authorized_keys files to allow for expiring keys. * ssh(1): Add a BindInterface option to allow binding the outgoing connection to an interface's address (basically a more usable BindAddress) * ssh(1): Expose device allocated for tun/tap forwarding via a new %T expansion for LocalCommand. This allows LocalCommand to be used to prepare the interface. * sshd(8): Expose the device allocated for tun/tap forwarding via a new SSH_TUNNEL environment variable. This allows automatic setup of the interface and surrounding network configuration automatically on the server. * ssh(1)/scp(1)/sftp(1): Add URI support to ssh, sftp and scp, e.g. ssh://user@host or sftp://user@host/path. Additional connection parameters described in draft-ietf-secsh-scp-sftp-ssh-uri-04 are not implemented since the ssh fingerprint format in the draft uses the deprecated MD5 hash with no way to specify the any other algorithm. * ssh-keygen(1): Allow certificate validity intervals that specify only a start or stop time (instead of both or neither). * sftp(1): Allow "cd" and "lcd" commands with no explicit path argument. lcd will change to the local user's home directory as usual. cd will change to the starting directory for session (because the protocol offers no way to obtain the remote user's home directory). bz#2760 * sshd(8): When doing a config test with sshd -T, only require the attributes that are actually used in Match criteria rather than (an incomplete list of) all criteria. Bugfixes -------- * ssh(1)/sshd(8): More strictly check signature types during key exchange against what was negotiated. Prevents downgrade of RSA signatures made with SHA-256/512 to SHA-1. * sshd(8): Fix support for client that advertise a protocol version of "1.99" (indicating that they are prepared to accept both SSHv1 and SSHv2). This was broken in OpenSSH 7.6 during the removal of SSHv1 support. bz#2810 * ssh(1): Warn when the agent returns a ssh-rsa (SHA1) signature when a rsa-sha2-256/512 signature was requested. This condition is possible when an old or non-OpenSSH agent is in use. bz#2799 * ssh-agent(1): Fix regression introduced in 7.6 that caused ssh-agent to fatally exit if presented an invalid signature request message. * sshd_config(5): Accept yes/no flag options case-insensitively, as has been the case in ssh_config(5) for a long time. bz#2664 * ssh(1): Improve error reporting for failures during connection. Under some circumstances misleading errors were being shown. bz#2814 * ssh-keyscan(1): Add -D option to allow printing of results directly in SSHFP format. bz#2821 * regress tests: fix PuTTY interop test broken in last release's SSHv1 removal. bz#2823 * ssh(1): Compatibility fix for some servers that erroneously drop the connection when the IUTF8 (RFC8160) option is sent. * scp(1): Disable RemoteCommand and RequestTTY in the ssh session started by scp (sftp was already doing this.) * ssh-keygen(1): Refuse to create a certificate with an unusable number of principals. * ssh-keygen(1): Fatally exit if ssh-keygen is unable to write all the public key during key generation. Previously it would silently ignore errors writing the comment and terminating newline. * ssh(1): Do not modify hostname arguments that are addresses by automatically forcing them to lower-case. Instead canonicalise them to resolve ambiguities (e.g. ::0001 => ::1) before they are matched against known_hosts. bz#2763 * ssh(1): Don't accept junk after "yes" or "no" responses to hostkey prompts. bz#2803 * sftp(1): Have sftp print a warning about shell cleanliness when decoding the first packet fails, which is usually caused by shells polluting stdout of non-interactive startups. bz#2800 * ssh(1)/sshd(8): Switch timers in packet code from using wall-clock time to monotonic time, allowing the packet layer to better function over a clock step and avoiding possible integer overflows during steps. * Numerous manual page fixes and improvements. Portability ----------- * sshd(8): Correctly detect MIPS ABI in use at configure time. Fixes sandbox violations on some environments. * sshd(8): Remove UNICOS support. The hardware and software are literal museum pieces and support in sshd is too intrusive to justify maintaining. * All: Build and link with "retpoline" flags when available to mitigate the "branch target injection" style (variant 2) of the Spectre branch-prediction vulnerability. * All: Add auto-generated dependency information to Makefile. * Numerous fixed to the RPM spec files. Checksums: ========== - SHA1 (openssh-7.7.tar.gz) = 24812e05fa233014c847c7775748316e7f8a836c - SHA256 (openssh-7.7.tar.gz) = T4ua1L/vgAYqwB0muRahvnm5ZUr3PLY9nPljaG8egvo= - SHA1 (openssh-7.7p1.tar.gz) = 446fe9ed171f289f0d62197dffdbfdaaf21c49f2 - SHA256 (openssh-7.7p1.tar.gz) = 1zvn5oTpnvzQJL4Vowv/y+QbASsvezyQhK7WIXdea48= Please note that the SHA256 signatures are base64 encoded and not hexadecimal (which is the default for most checksum tools). The PGP key used to sign the releases is available as RELEASE_KEY.asc from the mirror sites. Reporting Bugs: =============== - Please read http://www.openssh.com/report.html Security bugs should be reported directly to openssh@openssh.com
2018-04-06 21:56:05 +03:00
char **deny_groups;
import 5.2 from ftp.openbsd.org
2009-06-08 02:19:00 +04:00
u_int num_subsystems;
Import OpenSSH 9.5 (Last was OpenSSH 9.3) OpenSSH 9.5/9.5p1 (2023-10-04) OpenSSH 9.5 was released on 2023-10-04. It is available from the mirrors listed at https://www.openssh.com/. OpenSSH is a 100% complete SSH protocol 2.0 implementation and includes sftp client and server support. Once again, we would like to thank the OpenSSH community for their continued support of the project, especially those who contributed code or patches, reported bugs, tested snapshots or donated to the project. More information on donations may be found at: https://www.openssh.com/donations.html Changes since OpenSSH 9.4 ========================= This release fixes a number of bugs and adds some small features. Potentially incompatible changes -------------------------------- * ssh-keygen(1): generate Ed25519 keys by default. Ed25519 public keys are very convenient due to their small size. Ed25519 keys are specified in RFC 8709 and OpenSSH has supported them since version 6.5 (January 2014). * sshd(8): the Subsystem directive now accurately preserves quoting of subsystem commands and arguments. This may change behaviour for exotic configurations, but the most common subsystem configuration (sftp-server) is unlikely to be affected. New features ------------ * ssh(1): add keystroke timing obfuscation to the client. This attempts to hide inter-keystroke timings by sending interactive traffic at fixed intervals (default: every 20ms) when there is only a small amount of data being sent. It also sends fake "chaff" keystrokes for a random interval after the last real keystroke. These are controlled by a new ssh_config ObscureKeystrokeTiming keyword. * ssh(1), sshd(8): Introduce a transport-level ping facility. This adds a pair of SSH transport protocol messages SSH2_MSG_PING/PONG to implement a ping capability. These messages use numbers in the "local extensions" number space and are advertised using a "ping@openssh.com" ext-info message with a string version number of "0". * sshd(8): allow override of Subsystem directives in sshd Match blocks. Bugfixes -------- * scp(1): fix scp in SFTP mode recursive upload and download of directories that contain symlinks to other directories. In scp mode, the links would be followed, but in SFTP mode they were not. bz3611 * ssh-keygen(1): handle cr+lf (instead of just cr) line endings in sshsig signature files. * ssh(1): interactive mode for ControlPersist sessions if they originally requested a tty. * sshd(8): make PerSourceMaxStartups first-match-wins * sshd(8): limit artificial login delay to a reasonable maximum (5s) and don't delay at all for the "none" authentication mechanism.cw bz3602 * sshd(8): Log errors in kex_exchange_identification() with level verbose instead of error to reduce preauth log spam. All of those get logged with a more generic error message by sshpkt_fatal(). * sshd(8): correct math for ClientAliveInterval that caused the probes to be sent less frequently than configured. * ssh(1): fix regression in OpenSSH 9.4 (mux.c r1.99) that caused multiplexed sessions to ignore SIGINT under some circumstances. Portability ----------- * Avoid clang zero-call-used-regs=all bug on Apple compilers, which for some reason have version numbers that do not match the upstream clang version numbers. bz#3584 * Fix configure test for zlib 1.3 and later/development versions. bz3604 Checksums: ========== - SHA1 (openssh-9.5.tar.gz) = 8a0bd3a91fac338d97d91817af58df731f6509a3 - SHA256 (openssh-9.5.tar.gz) = sVMxeM3d6g65qBMktJIofxmK4Ipg9dblKif0VnhPeO0= - SHA1 (openssh-9.5p1.tar.gz) = 35c16dcc6e7d0a9465faa241476ef24f76b196cc - SHA256 (openssh-9.5p1.tar.gz) = 8Cbnt5un+1QPdRgq+W3IqPHbOV+SK7yfbKYDZyaGCGs= Please note that the SHA256 signatures are base64 encoded and not hexadecimal (which is the default for most checksum tools). The PGP key used to sign the releases is available from the mirror sites: https://cdn.openbsd.org/pub/OpenBSD/OpenSSH/RELEASE_KEY.asc Reporting Bugs: =============== - Please read https://www.openssh.com/report.html Security bugs should be reported directly to openssh@openssh.com OpenSSH 9.4/9.4p1 (2023-08-10) OpenSSH 9.4 was released on 2023-08-10. It is available from the mirrors listed at https://www.openssh.com/. OpenSSH is a 100% complete SSH protocol 2.0 implementation and includes sftp client and server support. Once again, we would like to thank the OpenSSH community for their continued support of the project, especially those who contributed code or patches, reported bugs, tested snapshots or donated to the project. More information on donations may be found at: https://www.openssh.com/donations.html Changes since OpenSSH 9.3p2 =========================== This release fixes a number of bugs and adds some small features. Potentially incompatible changes -------------------------------- * This release removes support for older versions of libcrypto. OpenSSH now requires LibreSSL >= 3.1.0 or OpenSSL >= 1.1.1. Note that these versions are already deprecated by their upstream vendors. * ssh-agent(1): PKCS#11 modules must now be specified by their full paths. Previously dlopen(3) could search for them in system library directories. New features ------------ * ssh(1): allow forwarding Unix Domain sockets via ssh -W. * ssh(1): add support for configuration tags to ssh(1). This adds a ssh_config(5) "Tag" directive and corresponding "Match tag" predicate that may be used to select blocks of configuration similar to the pf.conf(5) keywords of the same name. * ssh(1): add a "match localnetwork" predicate. This allows matching on the addresses of available network interfaces and may be used to vary the effective client configuration based on network location. * ssh(1), sshd(8), ssh-keygen(1): infrastructure support for KRL extensions. This defines wire formats for optional KRL extensions and implements parsing of the new submessages. No actual extensions are supported at this point. * sshd(8): AuthorizedPrincipalsCommand and AuthorizedKeysCommand now accept two additional %-expansion sequences: %D which expands to the routing domain of the connected session and %C which expands to the addresses and port numbers for the source and destination of the connection. * ssh-keygen(1): increase the default work factor (rounds) for the bcrypt KDF used to derive symmetric encryption keys for passphrase protected key files by 50%. Bugfixes -------- * ssh-agent(1): improve isolation between loaded PKCS#11 modules by running separate ssh-pkcs11-helpers for each loaded provider. * ssh(1): make -f (fork after authentication) work correctly with multiplexed connections, including ControlPersist. bz3589 bz3589 * ssh(1): make ConnectTimeout apply to multiplexing sockets and not just to network connections. * ssh-agent(1), ssh(1): improve defences against invalid PKCS#11 modules being loaded by checking that the requested module contains the required symbol before loading it. * sshd(8): fix AuthorizedPrincipalsCommand when AuthorizedKeysCommand appears before it in sshd_config. Since OpenSSH 8.7 the AuthorizedPrincipalsCommand directive was incorrectly ignored in this situation. bz3574 * sshd(8), ssh(1), ssh-keygen(1): remove vestigal support for KRL signatures When the KRL format was originally defined, it included support for signing of KRL objects. However, the code to sign KRLs and verify KRL signatues was never completed in OpenSSH. This release removes the partially-implemented code to verify KRLs. All OpenSSH tools now ignore KRL_SECTION_SIGNATURE sections in KRL files. * All: fix a number of memory leaks and unreachable/harmless integer overflows. * ssh-agent(1), ssh(1): don't truncate strings logged from PKCS#11 modules; GHPR406 * sshd(8), ssh(1): better validate CASignatureAlgorithms in ssh_config and sshd_config. Previously this directive would accept certificate algorithm names, but these were unusable in practice as OpenSSH does not support CA chains. bz3577 * ssh(1): make `ssh -Q CASignatureAlgorithms` only list signature algorithms that are valid for CA signing. Previous behaviour was to list all signing algorithms, including certificate algorithms. * ssh-keyscan(1): gracefully handle systems where rlimits or the maximum number of open files is larger than INT_MAX; bz3581 * ssh-keygen(1): fix "no comment" not showing on when running `ssh-keygen -l` on multiple keys where one has a comment and other following keys do not. bz3580 * scp(1), sftp(1): adjust ftruncate() logic to handle servers that reorder requests. Previously, if the server reordered requests then the resultant file would be erroneously truncated. * ssh(1): don't incorrectly disable hostname canonicalization when CanonicalizeHostname=yes and ProxyJump was expicitly set to "none". bz3567 * scp(1): when copying local->remote, check that the source file exists before opening an SFTP connection to the server. Based on GHPR#370 Portability ----------- * All: a number of build fixes for various platforms and configuration combinations. * sshd(8): provide a replacement for the SELinux matchpathcon() function, which is deprecated. * All: relax libcrypto version checks for OpenSSL >=3. Beyond OpenSSL 3.0, the ABI compatibility guarantees are wider (only the library major must match instead of major and minor in earlier versions). bz#3548. * Tests: fix build problems for the sk-dummy.so FIDO provider module used in some tests. Checksums: ========== - SHA1 (openssh-9.4.tar.gz) = d88126d8d7b8e5bf4656587ac4a16055560641cc - SHA256 (openssh-9.4.tar.gz) = 7eqFjx2hAunw+1Jy7f1JQXq//3AMr9B3dKtASDtq8go= - SHA1 (openssh-9.4p1.tar.gz) = 5dea1f3c88f9cfe53a711a3c893ee8b7d3ffecff - SHA256 (openssh-9.4p1.tar.gz) = Ngj9kIjbIWPOs+YAyFq3nQ3j0iHlkZLqGSPiMmOGaoU= Please note that the SHA256 signatures are base64 encoded and not hexadecimal (which is the default for most checksum tools). The PGP key used to sign the releases is available from the mirror sites: https://cdn.openbsd.org/pub/OpenBSD/OpenSSH/RELEASE_KEY.asc Reporting Bugs: =============== - Please read https://www.openssh.com/report.html Security bugs should be reported directly to openssh@openssh.com
2023-10-25 23:14:30 +03:00
char **subsystem_name;
char **subsystem_command;
char **subsystem_args;
import 5.2 from ftp.openbsd.org
2009-06-08 02:19:00 +04:00
u_int num_accept_env;
OpenSSH 7.7 was released on 2018-04-02. It is available from the mirrors listed at http://www.openssh.com/ shortly. OpenSSH is a 100% complete SSH protocol 2.0 implementation and includes sftp client and server support. Once again, we would like to thank the OpenSSH community for their continued support of the project, especially those who contributed code or patches, reported bugs, tested snapshots or donated to the project. More information on donations may be found at: http://www.openssh.com/donations.html Potentially-incompatible changes ================================ This release includes a number of changes that may affect existing configurations: * ssh(1)/sshd(8): Drop compatibility support for some very old SSH implementations, including ssh.com <=2.* and OpenSSH <= 3.*. These versions were all released in or before 2001 and predate the final SSH RFCs. The support in question isn't necessary for RFC-compliant SSH implementations. Changes since OpenSSH 7.6 ========================= This is primarily a bugfix release. New Features ------------ * All: Add experimental support for PQC XMSS keys (Extended Hash- Based Signatures) based on the algorithm described in https://tools.ietf.org/html/draft-irtf-cfrg-xmss-hash-based-signatures-12 The XMSS signature code is experimental and not compiled in by default. * sshd(8): Add a "rdomain" criteria for the sshd_config Match keyword to allow conditional configuration that depends on which routing domain a connection was received on (currently supported on OpenBSD and Linux). * sshd_config(5): Add an optional rdomain qualifier to the ListenAddress directive to allow listening on different routing domains. This is supported only on OpenBSD and Linux at present. * sshd_config(5): Add RDomain directive to allow the authenticated session to be placed in an explicit routing domain. This is only supported on OpenBSD at present. * sshd(8): Add "expiry-time" option for authorized_keys files to allow for expiring keys. * ssh(1): Add a BindInterface option to allow binding the outgoing connection to an interface's address (basically a more usable BindAddress) * ssh(1): Expose device allocated for tun/tap forwarding via a new %T expansion for LocalCommand. This allows LocalCommand to be used to prepare the interface. * sshd(8): Expose the device allocated for tun/tap forwarding via a new SSH_TUNNEL environment variable. This allows automatic setup of the interface and surrounding network configuration automatically on the server. * ssh(1)/scp(1)/sftp(1): Add URI support to ssh, sftp and scp, e.g. ssh://user@host or sftp://user@host/path. Additional connection parameters described in draft-ietf-secsh-scp-sftp-ssh-uri-04 are not implemented since the ssh fingerprint format in the draft uses the deprecated MD5 hash with no way to specify the any other algorithm. * ssh-keygen(1): Allow certificate validity intervals that specify only a start or stop time (instead of both or neither). * sftp(1): Allow "cd" and "lcd" commands with no explicit path argument. lcd will change to the local user's home directory as usual. cd will change to the starting directory for session (because the protocol offers no way to obtain the remote user's home directory). bz#2760 * sshd(8): When doing a config test with sshd -T, only require the attributes that are actually used in Match criteria rather than (an incomplete list of) all criteria. Bugfixes -------- * ssh(1)/sshd(8): More strictly check signature types during key exchange against what was negotiated. Prevents downgrade of RSA signatures made with SHA-256/512 to SHA-1. * sshd(8): Fix support for client that advertise a protocol version of "1.99" (indicating that they are prepared to accept both SSHv1 and SSHv2). This was broken in OpenSSH 7.6 during the removal of SSHv1 support. bz#2810 * ssh(1): Warn when the agent returns a ssh-rsa (SHA1) signature when a rsa-sha2-256/512 signature was requested. This condition is possible when an old or non-OpenSSH agent is in use. bz#2799 * ssh-agent(1): Fix regression introduced in 7.6 that caused ssh-agent to fatally exit if presented an invalid signature request message. * sshd_config(5): Accept yes/no flag options case-insensitively, as has been the case in ssh_config(5) for a long time. bz#2664 * ssh(1): Improve error reporting for failures during connection. Under some circumstances misleading errors were being shown. bz#2814 * ssh-keyscan(1): Add -D option to allow printing of results directly in SSHFP format. bz#2821 * regress tests: fix PuTTY interop test broken in last release's SSHv1 removal. bz#2823 * ssh(1): Compatibility fix for some servers that erroneously drop the connection when the IUTF8 (RFC8160) option is sent. * scp(1): Disable RemoteCommand and RequestTTY in the ssh session started by scp (sftp was already doing this.) * ssh-keygen(1): Refuse to create a certificate with an unusable number of principals. * ssh-keygen(1): Fatally exit if ssh-keygen is unable to write all the public key during key generation. Previously it would silently ignore errors writing the comment and terminating newline. * ssh(1): Do not modify hostname arguments that are addresses by automatically forcing them to lower-case. Instead canonicalise them to resolve ambiguities (e.g. ::0001 => ::1) before they are matched against known_hosts. bz#2763 * ssh(1): Don't accept junk after "yes" or "no" responses to hostkey prompts. bz#2803 * sftp(1): Have sftp print a warning about shell cleanliness when decoding the first packet fails, which is usually caused by shells polluting stdout of non-interactive startups. bz#2800 * ssh(1)/sshd(8): Switch timers in packet code from using wall-clock time to monotonic time, allowing the packet layer to better function over a clock step and avoiding possible integer overflows during steps. * Numerous manual page fixes and improvements. Portability ----------- * sshd(8): Correctly detect MIPS ABI in use at configure time. Fixes sandbox violations on some environments. * sshd(8): Remove UNICOS support. The hardware and software are literal museum pieces and support in sshd is too intrusive to justify maintaining. * All: Build and link with "retpoline" flags when available to mitigate the "branch target injection" style (variant 2) of the Spectre branch-prediction vulnerability. * All: Add auto-generated dependency information to Makefile. * Numerous fixed to the RPM spec files. Checksums: ========== - SHA1 (openssh-7.7.tar.gz) = 24812e05fa233014c847c7775748316e7f8a836c - SHA256 (openssh-7.7.tar.gz) = T4ua1L/vgAYqwB0muRahvnm5ZUr3PLY9nPljaG8egvo= - SHA1 (openssh-7.7p1.tar.gz) = 446fe9ed171f289f0d62197dffdbfdaaf21c49f2 - SHA256 (openssh-7.7p1.tar.gz) = 1zvn5oTpnvzQJL4Vowv/y+QbASsvezyQhK7WIXdea48= Please note that the SHA256 signatures are base64 encoded and not hexadecimal (which is the default for most checksum tools). The PGP key used to sign the releases is available as RELEASE_KEY.asc from the mirror sites. Reporting Bugs: =============== - Please read http://www.openssh.com/report.html Security bugs should be reported directly to openssh@openssh.com
2018-04-06 21:56:05 +03:00
char **accept_env;
Potentially-incompatible changes ================================ This release includes a number of changes that may affect existing configurations: * ssh-keygen(1): write OpenSSH format private keys by default instead of using OpenSSL's PEM format. The OpenSSH format, supported in OpenSSH releases since 2014 and described in the PROTOCOL.key file in the source distribution, offers substantially better protection against offline password guessing and supports key comments in private keys. If necessary, it is possible to write old PEM-style keys by adding "-m PEM" to ssh-keygen's arguments when generating or updating a key. * sshd(8): remove internal support for S/Key multiple factor authentication. S/Key may still be used via PAM or BSD auth. * ssh(1): remove vestigal support for running ssh(1) as setuid. This used to be required for hostbased authentication and the (long gone) rhosts-style authentication, but has not been necessary for a long time. Attempting to execute ssh as a setuid binary, or with uid != effective uid will now yield a fatal error at runtime. * sshd(8): the semantics of PubkeyAcceptedKeyTypes and the similar HostbasedAcceptedKeyTypes options have changed. These now specify signature algorithms that are accepted for their respective authentication mechanism, where previously they specified accepted key types. This distinction matters when using the RSA/SHA2 signature algorithms "rsa-sha2-256", "rsa-sha2-512" and their certificate counterparts. Configurations that override these options but omit these algorithm names may cause unexpected authentication failures (no action is required for configurations that accept the default for these options). * sshd(8): the precedence of session environment variables has changed. ~/.ssh/environment and environment="..." options in authorized_keys files can no longer override SSH_* variables set implicitly by sshd. * ssh(1)/sshd(8): the default IPQoS used by ssh/sshd has changed. They will now use DSCP AF21 for interactive traffic and CS1 for bulk. For a detailed rationale, please see the commit message: https://cvsweb.openbsd.org/src/usr.bin/ssh/readconf.c#rev1.284
2018-08-26 10:39:56 +03:00
u_int num_setenv;
char **setenv;
import 5.2 from ftp.openbsd.org
2009-06-08 02:19:00 +04:00
int max_startups_begin;
int max_startups_rate;
int max_startups;
OpenSSH 8.5/8.5p1 (2021-03-03) OpenSSH 8.5 was released on 2021-03-03. It is available from the mirrors listed at https://www.openssh.com/. OpenSSH is a 100% complete SSH protocol 2.0 implementation and includes sftp client and server support. Once again, we would like to thank the OpenSSH community for their continued support of the project, especially those who contributed code or patches, reported bugs, tested snapshots or donated to the project. More information on donations may be found at: https://www.openssh.com/donations.html Future deprecation notice ========================= It is now possible[1] to perform chosen-prefix attacks against the SHA-1 algorithm for less than USD$50K. In the SSH protocol, the "ssh-rsa" signature scheme uses the SHA-1 hash algorithm in conjunction with the RSA public key algorithm. OpenSSH will disable this signature scheme by default in the near future. Note that the deactivation of "ssh-rsa" signatures does not necessarily require cessation of use for RSA keys. In the SSH protocol, keys may be capable of signing using multiple algorithms. In particular, "ssh-rsa" keys are capable of signing using "rsa-sha2-256" (RSA/SHA256), "rsa-sha2-512" (RSA/SHA512) and "ssh-rsa" (RSA/SHA1). Only the last of these is being turned off by default. This algorithm is unfortunately still used widely despite the existence of better alternatives, being the only remaining public key signature algorithm specified by the original SSH RFCs that is still enabled by default. The better alternatives include: * The RFC8332 RSA SHA-2 signature algorithms rsa-sha2-256/512. These algorithms have the advantage of using the same key type as "ssh-rsa" but use the safe SHA-2 hash algorithms. These have been supported since OpenSSH 7.2 and are already used by default if the client and server support them. * The RFC8709 ssh-ed25519 signature algorithm. It has been supported in OpenSSH since release 6.5. * The RFC5656 ECDSA algorithms: ecdsa-sha2-nistp256/384/521. These have been supported by OpenSSH since release 5.7. To check whether a server is using the weak ssh-rsa public key algorithm, for host authentication, try to connect to it after removing the ssh-rsa algorithm from ssh(1)'s allowed list: ssh -oHostKeyAlgorithms=-ssh-rsa user@host If the host key verification fails and no other supported host key types are available, the server software on that host should be upgraded. This release enables the UpdateHostKeys option by default to assist the client by automatically migrating to better algorithms. [1] "SHA-1 is a Shambles: First Chosen-Prefix Collision on SHA-1 and Application to the PGP Web of Trust" Leurent, G and Peyrin, T (2020) https://eprint.iacr.org/2020/014.pdf Security ======== * ssh-agent(1): fixed a double-free memory corruption that was introduced in OpenSSH 8.2 . We treat all such memory faults as potentially exploitable. This bug could be reached by an attacker with access to the agent socket. On modern operating systems where the OS can provide information about the user identity connected to a socket, OpenSSH ssh-agent and sshd limit agent socket access only to the originating user and root. Additional mitigation may be afforded by the system's malloc(3)/free(3) implementation, if it detects double-free conditions. The most likely scenario for exploitation is a user forwarding an agent either to an account shared with a malicious user or to a host with an attacker holding root access. * Portable sshd(8): Prevent excessively long username going to PAM. This is a mitigation for a buffer overflow in Solaris' PAM username handling (CVE-2020-14871), and is only enabled for Sun-derived PAM implementations. This is not a problem in sshd itself, it only prevents sshd from being used as a vector to attack Solaris' PAM. It does not prevent the bug in PAM from being exploited via some other PAM application. GHPR212 Potentially-incompatible changes ================================ This release includes a number of changes that may affect existing configurations: * ssh(1), sshd(8): this release changes the first-preference signature algorithm from ECDSA to ED25519. * ssh(1), sshd(8): set the TOS/DSCP specified in the configuration for interactive use prior to TCP connect. The connection phase of the SSH session is time-sensitive and often explicitly interactive. The ultimate interactive/bulk TOS/DSCP will be set after authentication completes. * ssh(1), sshd(8): remove the pre-standardization cipher rijndael-cbc@lysator.liu.se. It is an alias for aes256-cbc before it was standardized in RFC4253 (2006), has been deprecated and disabled by default since OpenSSH 7.2 (2016) and was only briefly documented in ssh.1 in 2001. * ssh(1), sshd(8): update/replace the experimental post-quantum hybrid key exchange method based on Streamlined NTRU Prime coupled with X25519. The previous sntrup4591761x25519-sha512@tinyssh.org method is replaced with sntrup761x25519-sha512@openssh.com. Per its designers, the sntrup4591761 algorithm was superseded almost two years ago by sntrup761. (note this both the updated method and the one that it replaced are disabled by default) * ssh(1): disable CheckHostIP by default. It provides insignificant benefits while making key rotation significantly more difficult, especially for hosts behind IP-based load-balancers. Changes since OpenSSH 8.4 ========================= New features ------------ * ssh(1): this release enables UpdateHostkeys by default subject to some conservative preconditions: - The key was matched in the UserKnownHostsFile (and not in the GlobalKnownHostsFile). - The same key does not exist under another name. - A certificate host key is not in use. - known_hosts contains no matching wildcard hostname pattern. - VerifyHostKeyDNS is not enabled. - The default UserKnownHostsFile is in use. We expect some of these conditions will be modified or relaxed in future. * ssh(1), sshd(8): add a new LogVerbose configuration directive for that allows forcing maximum debug logging by file/function/line pattern-lists. * ssh(1): when prompting the user to accept a new hostkey, display any other host names/addresses already associated with the key. * ssh(1): allow UserKnownHostsFile=none to indicate that no known_hosts file should be used to identify host keys. * ssh(1): add a ssh_config KnownHostsCommand option that allows the client to obtain known_hosts data from a command in addition to the usual files. * ssh(1): add a ssh_config PermitRemoteOpen option that allows the client to restrict the destination when RemoteForward is used with SOCKS. * ssh(1): for FIDO keys, if a signature operation fails with a "incorrect PIN" reason and no PIN was initially requested from the user, then request a PIN and retry the operation. This supports some biometric devices that fall back to requiring PIN when reading of the biometric failed, and devices that require PINs for all hosted credentials. * sshd(8): implement client address-based rate-limiting via new sshd_config(5) PerSourceMaxStartups and PerSourceNetBlockSize directives that provide more fine-grained control on a per-origin address basis than the global MaxStartups limit. Bugfixes -------- * ssh(1): Prefix keyboard interactive prompts with "(user@host)" to make it easier to determine which connection they are associated with in cases like scp -3, ProxyJump, etc. bz#3224 * sshd(8): fix sshd_config SetEnv directives located inside Match blocks. GHPR201 * ssh(1): when requesting a FIDO token touch on stderr, inform the user once the touch has been recorded. * ssh(1): prevent integer overflow when ridiculously large ConnectTimeout values are specified, capping the effective value (for most platforms) at 24 days. bz#3229 * ssh(1): consider the ECDSA key subtype when ordering host key algorithms in the client. * ssh(1), sshd(8): rename the PubkeyAcceptedKeyTypes keyword to PubkeyAcceptedAlgorithms. The previous name incorrectly suggested that it control allowed key algorithms, when this option actually specifies the signature algorithms that are accepted. The previous name remains available as an alias. bz#3253 * ssh(1), sshd(8): similarly, rename HostbasedKeyTypes (ssh) and HostbasedAcceptedKeyTypes (sshd) to HostbasedAcceptedAlgorithms. * sftp-server(8): add missing lsetstat@openssh.com documentation and advertisement in the server's SSH2_FXP_VERSION hello packet. * ssh(1), sshd(8): more strictly enforce KEX state-machine by banning packet types once they are received. Fixes memleak caused by duplicate SSH2_MSG_KEX_DH_GEX_REQUEST (oss-fuzz #30078). * sftp(1): allow the full range of UIDs/GIDs for chown/chgrp on 32bit platforms instead of being limited by LONG_MAX. bz#3206 * Minor man page fixes (capitalization, commas, etc.) bz#3223 * sftp(1): when doing an sftp recursive upload or download of a read-only directory, ensure that the directory is created with write and execute permissions in the interim so that the transfer can actually complete, then set the directory permission as the final step. bz#3222 * ssh-keygen(1): document the -Z, check the validity of its argument earlier and provide a better error message if it's not correct. bz#2879 * ssh(1): ignore comments at the end of config lines in ssh_config, similar to what we already do for sshd_config. bz#2320 * sshd_config(5): mention that DisableForwarding is valid in a sshd_config Match block. bz3239 * sftp(1): fix incorrect sorting of "ls -ltr" under some circumstances. bz3248. * ssh(1), sshd(8): fix potential integer truncation of (unlikely) timeout values. bz#3250 * ssh(1): make hostbased authentication send the signature algorithm in its SSH2_MSG_USERAUTH_REQUEST packets instead of the key type. This make HostbasedAcceptedAlgorithms do what it is supposed to - filter on signature algorithm and not key type. Portability ----------- * sshd(8): add a number of platform-specific syscalls to the Linux seccomp-bpf sandbox. bz#3232 bz#3260 * sshd(8): remove debug message from sigchld handler that could cause deadlock on some platforms. bz#3259 * Sync contrib/ssh-copy-id with upstream. * unittests: add a hostname function for systems that don't have it. Some systems don't have a hostname command (it's not required by POSIX). The do have uname -n (which is), but not all of those have it report the FQDN. Checksums: ========== - SHA1 (openssh-8.5.tar.gz) = 04cae43c389fb411227c01219e4eb46e3113f34e - SHA256 (openssh-8.5.tar.gz) = 5qB2CgzNG4io4DmChTjHgCWqRWvEOvCKJskLdJCz+SU= - SHA1 (openssh-8.5p1.tar.gz) = 72eadcbe313b07b1dd3b693e41d3cd56d354e24e - SHA256 (openssh-8.5p1.tar.gz) = 9S8/QdQpqpkY44zyAK8iXM3Y5m8FLaVyhwyJc3ZG7CU= Please note that the SHA256 signatures are base64 encoded and not hexadecimal (which is the default for most checksum tools). The PGP key used to sign the releases is available from the mirror sites: https://cdn.openbsd.org/pub/OpenBSD/OpenSSH/RELEASE_KEY.asc Please note that the OpenPGP key used to sign releases has been rotated for this release. The new key has been signed by the previous key to provide continuity. Reporting Bugs: =============== - Please read https://www.openssh.com/report.html Security bugs should be reported directly to openssh@openssh.com
2021-03-05 20:45:24 +03:00
int per_source_max_startups;
int per_source_masklen_ipv4;
int per_source_masklen_ipv6;
import 5.2 from ftp.openbsd.org
2009-06-08 02:19:00 +04:00
int max_authtries;
int max_sessions;
char *banner; /* SSH-2 banner message */
int use_dns;
int client_alive_interval; /*
* poke the client this often to
* see if it's still there
*/
int client_alive_count_max; /*
* If the client is unresponsive
* for this many intervals above,
* disconnect the session
*/
OpenSSH 7.7 was released on 2018-04-02. It is available from the mirrors listed at http://www.openssh.com/ shortly. OpenSSH is a 100% complete SSH protocol 2.0 implementation and includes sftp client and server support. Once again, we would like to thank the OpenSSH community for their continued support of the project, especially those who contributed code or patches, reported bugs, tested snapshots or donated to the project. More information on donations may be found at: http://www.openssh.com/donations.html Potentially-incompatible changes ================================ This release includes a number of changes that may affect existing configurations: * ssh(1)/sshd(8): Drop compatibility support for some very old SSH implementations, including ssh.com <=2.* and OpenSSH <= 3.*. These versions were all released in or before 2001 and predate the final SSH RFCs. The support in question isn't necessary for RFC-compliant SSH implementations. Changes since OpenSSH 7.6 ========================= This is primarily a bugfix release. New Features ------------ * All: Add experimental support for PQC XMSS keys (Extended Hash- Based Signatures) based on the algorithm described in https://tools.ietf.org/html/draft-irtf-cfrg-xmss-hash-based-signatures-12 The XMSS signature code is experimental and not compiled in by default. * sshd(8): Add a "rdomain" criteria for the sshd_config Match keyword to allow conditional configuration that depends on which routing domain a connection was received on (currently supported on OpenBSD and Linux). * sshd_config(5): Add an optional rdomain qualifier to the ListenAddress directive to allow listening on different routing domains. This is supported only on OpenBSD and Linux at present. * sshd_config(5): Add RDomain directive to allow the authenticated session to be placed in an explicit routing domain. This is only supported on OpenBSD at present. * sshd(8): Add "expiry-time" option for authorized_keys files to allow for expiring keys. * ssh(1): Add a BindInterface option to allow binding the outgoing connection to an interface's address (basically a more usable BindAddress) * ssh(1): Expose device allocated for tun/tap forwarding via a new %T expansion for LocalCommand. This allows LocalCommand to be used to prepare the interface. * sshd(8): Expose the device allocated for tun/tap forwarding via a new SSH_TUNNEL environment variable. This allows automatic setup of the interface and surrounding network configuration automatically on the server. * ssh(1)/scp(1)/sftp(1): Add URI support to ssh, sftp and scp, e.g. ssh://user@host or sftp://user@host/path. Additional connection parameters described in draft-ietf-secsh-scp-sftp-ssh-uri-04 are not implemented since the ssh fingerprint format in the draft uses the deprecated MD5 hash with no way to specify the any other algorithm. * ssh-keygen(1): Allow certificate validity intervals that specify only a start or stop time (instead of both or neither). * sftp(1): Allow "cd" and "lcd" commands with no explicit path argument. lcd will change to the local user's home directory as usual. cd will change to the starting directory for session (because the protocol offers no way to obtain the remote user's home directory). bz#2760 * sshd(8): When doing a config test with sshd -T, only require the attributes that are actually used in Match criteria rather than (an incomplete list of) all criteria. Bugfixes -------- * ssh(1)/sshd(8): More strictly check signature types during key exchange against what was negotiated. Prevents downgrade of RSA signatures made with SHA-256/512 to SHA-1. * sshd(8): Fix support for client that advertise a protocol version of "1.99" (indicating that they are prepared to accept both SSHv1 and SSHv2). This was broken in OpenSSH 7.6 during the removal of SSHv1 support. bz#2810 * ssh(1): Warn when the agent returns a ssh-rsa (SHA1) signature when a rsa-sha2-256/512 signature was requested. This condition is possible when an old or non-OpenSSH agent is in use. bz#2799 * ssh-agent(1): Fix regression introduced in 7.6 that caused ssh-agent to fatally exit if presented an invalid signature request message. * sshd_config(5): Accept yes/no flag options case-insensitively, as has been the case in ssh_config(5) for a long time. bz#2664 * ssh(1): Improve error reporting for failures during connection. Under some circumstances misleading errors were being shown. bz#2814 * ssh-keyscan(1): Add -D option to allow printing of results directly in SSHFP format. bz#2821 * regress tests: fix PuTTY interop test broken in last release's SSHv1 removal. bz#2823 * ssh(1): Compatibility fix for some servers that erroneously drop the connection when the IUTF8 (RFC8160) option is sent. * scp(1): Disable RemoteCommand and RequestTTY in the ssh session started by scp (sftp was already doing this.) * ssh-keygen(1): Refuse to create a certificate with an unusable number of principals. * ssh-keygen(1): Fatally exit if ssh-keygen is unable to write all the public key during key generation. Previously it would silently ignore errors writing the comment and terminating newline. * ssh(1): Do not modify hostname arguments that are addresses by automatically forcing them to lower-case. Instead canonicalise them to resolve ambiguities (e.g. ::0001 => ::1) before they are matched against known_hosts. bz#2763 * ssh(1): Don't accept junk after "yes" or "no" responses to hostkey prompts. bz#2803 * sftp(1): Have sftp print a warning about shell cleanliness when decoding the first packet fails, which is usually caused by shells polluting stdout of non-interactive startups. bz#2800 * ssh(1)/sshd(8): Switch timers in packet code from using wall-clock time to monotonic time, allowing the packet layer to better function over a clock step and avoiding possible integer overflows during steps. * Numerous manual page fixes and improvements. Portability ----------- * sshd(8): Correctly detect MIPS ABI in use at configure time. Fixes sandbox violations on some environments. * sshd(8): Remove UNICOS support. The hardware and software are literal museum pieces and support in sshd is too intrusive to justify maintaining. * All: Build and link with "retpoline" flags when available to mitigate the "branch target injection" style (variant 2) of the Spectre branch-prediction vulnerability. * All: Add auto-generated dependency information to Makefile. * Numerous fixed to the RPM spec files. Checksums: ========== - SHA1 (openssh-7.7.tar.gz) = 24812e05fa233014c847c7775748316e7f8a836c - SHA256 (openssh-7.7.tar.gz) = T4ua1L/vgAYqwB0muRahvnm5ZUr3PLY9nPljaG8egvo= - SHA1 (openssh-7.7p1.tar.gz) = 446fe9ed171f289f0d62197dffdbfdaaf21c49f2 - SHA256 (openssh-7.7p1.tar.gz) = 1zvn5oTpnvzQJL4Vowv/y+QbASsvezyQhK7WIXdea48= Please note that the SHA256 signatures are base64 encoded and not hexadecimal (which is the default for most checksum tools). The PGP key used to sign the releases is available as RELEASE_KEY.asc from the mirror sites. Reporting Bugs: =============== - Please read http://www.openssh.com/report.html Security bugs should be reported directly to openssh@openssh.com
2018-04-06 21:56:05 +03:00
u_int num_authkeys_files; /* Files containing public keys */
char **authorized_keys_files;
import 5.2 from ftp.openbsd.org
2009-06-08 02:19:00 +04:00
char *adm_forced_command;
int permit_tun;
Potentially-incompatible changes ================================ This release includes a number of changes that may affect existing configurations: * ssh-keygen(1): write OpenSSH format private keys by default instead of using OpenSSL's PEM format. The OpenSSH format, supported in OpenSSH releases since 2014 and described in the PROTOCOL.key file in the source distribution, offers substantially better protection against offline password guessing and supports key comments in private keys. If necessary, it is possible to write old PEM-style keys by adding "-m PEM" to ssh-keygen's arguments when generating or updating a key. * sshd(8): remove internal support for S/Key multiple factor authentication. S/Key may still be used via PAM or BSD auth. * ssh(1): remove vestigal support for running ssh(1) as setuid. This used to be required for hostbased authentication and the (long gone) rhosts-style authentication, but has not been necessary for a long time. Attempting to execute ssh as a setuid binary, or with uid != effective uid will now yield a fatal error at runtime. * sshd(8): the semantics of PubkeyAcceptedKeyTypes and the similar HostbasedAcceptedKeyTypes options have changed. These now specify signature algorithms that are accepted for their respective authentication mechanism, where previously they specified accepted key types. This distinction matters when using the RSA/SHA2 signature algorithms "rsa-sha2-256", "rsa-sha2-512" and their certificate counterparts. Configurations that override these options but omit these algorithm names may cause unexpected authentication failures (no action is required for configurations that accept the default for these options). * sshd(8): the precedence of session environment variables has changed. ~/.ssh/environment and environment="..." options in authorized_keys files can no longer override SSH_* variables set implicitly by sshd. * ssh(1)/sshd(8): the default IPQoS used by ssh/sshd has changed. They will now use DSCP AF21 for interactive traffic and CS1 for bulk. For a detailed rationale, please see the commit message: https://cvsweb.openbsd.org/src/usr.bin/ssh/readconf.c#rev1.284
2018-08-26 10:39:56 +03:00
char **permitted_opens; /* May also be one of PERMITOPEN_* */
u_int num_permitted_opens;
char **permitted_listens; /* May also be one of PERMITOPEN_* */
u_int num_permitted_listens;
import 5.2 from ftp.openbsd.org
2009-06-08 02:19:00 +04:00
char *chroot_directory;
Imported openssh-5.6
2010-11-21 20:05:36 +03:00
char *revoked_keys_file;
char *trusted_user_ca_keys;
from openbsd
2013-03-29 18:52:38 +04:00
char *authorized_keys_command;
char *authorized_keys_command_user;
Changes since OpenSSH 6.8 ========================= This is primarily a bugfix release. Security -------- * ssh(1): when forwarding X11 connections with ForwardX11Trusted=no, connections made after ForwardX11Timeout expired could be permitted and no longer subject to XSECURITY restrictions because of an ineffective timeout check in ssh(1) coupled with "fail open" behaviour in the X11 server when clients attempted connections with expired credentials. This problem was reported by Jann Horn. * ssh-agent(1): fix weakness of agent locking (ssh-add -x) to password guessing by implementing an increasing failure delay, storing a salted hash of the password rather than the password itself and using a timing-safe comparison function for verifying unlock attempts. This problem was reported by Ryan Castellucci. New Features ------------ * ssh(1), sshd(8): promote chacha20-poly1305@openssh.com to be the default cipher * sshd(8): support admin-specified arguments to AuthorizedKeysCommand; bz#2081 * sshd(8): add AuthorizedPrincipalsCommand that allows retrieving authorized principals information from a subprocess rather than a file. * ssh(1), ssh-add(1): support PKCS#11 devices with external PIN entry devices bz#2240 * sshd(8): allow GSSAPI host credential check to be relaxed for multihomed hosts via GSSAPIStrictAcceptorCheck option; bz#928 * ssh-keygen(1): support "ssh-keygen -lF hostname" to search known_hosts and print key hashes rather than full keys. * ssh-agent(1): add -D flag to leave ssh-agent in foreground without enabling debug mode; bz#2381 Bugfixes -------- * ssh(1), sshd(8): deprecate legacy SSH2_MSG_KEX_DH_GEX_REQUEST_OLD message and do not try to use it against some 3rd-party SSH implementations that use it (older PuTTY, WinSCP). * Many fixes for problems caused by compile-time deactivation of SSH1 support (including bz#2369) * ssh(1), sshd(8): cap DH-GEX group size at 4Kbits for Cisco implementations as some would fail when attempting to use group sizes >4K; bz#2209 * ssh(1): fix out-of-bound read in EscapeChar configuration option parsing; bz#2396 * sshd(8): fix application of PermitTunnel, LoginGraceTime, AuthenticationMethods and StreamLocalBindMask options in Match blocks * ssh(1), sshd(8): improve disconnection message on TCP reset; bz#2257 * ssh(1): remove failed remote forwards established by muliplexing from the list of active forwards; bz#2363 * sshd(8): make parsing of authorized_keys "environment=" options independent of PermitUserEnv being enabled; bz#2329 * sshd(8): fix post-auth crash with permitopen=none; bz#2355 * ssh(1), ssh-add(1), ssh-keygen(1): allow new-format private keys to be encrypted with AEAD ciphers; bz#2366 * ssh(1): allow ListenAddress, Port and AddressFamily configuration options to appear in any order; bz#86 * sshd(8): check for and reject missing arguments for VersionAddendum and ForceCommand; bz#2281 * ssh(1), sshd(8): don't treat unknown certificate extensions as fatal; bz#2387 * ssh-keygen(1): make stdout and stderr output consistent; bz#2325 * ssh(1): mention missing DISPLAY environment in debug log when X11 forwarding requested; bz#1682 * sshd(8): correctly record login when UseLogin is set; bz#378 * sshd(8): Add some missing options to sshd -T output and fix output of VersionAddendum and HostCertificate. bz#2346 * Document and improve consistency of options that accept a "none" argument" TrustedUserCAKeys, RevokedKeys (bz#2382), AuthorizedPrincipalsFile (bz#2288) * ssh(1): include remote username in debug output; bz#2368 * sshd(8): avoid compatibility problem with some versions of Tera Term, which would crash when they received the hostkeys notification message (hostkeys-00@openssh.com) * sshd(8): mention ssh-keygen -E as useful when comparing legacy MD5 host key fingerprints; bz#2332 * ssh(1): clarify pseudo-terminal request behaviour and use make manual language consistent; bz#1716 * ssh(1): document that the TERM environment variable is not subject to SendEnv and AcceptEnv; bz#2386
2015-07-03 03:54:41 +03:00
char *authorized_principals_file;
char *authorized_principals_command;
char *authorized_principals_command_user;
From ftp.openbsd.org
2012-12-12 20:52:18 +04:00
Import new openssh to address Changes since OpenSSH 6.3 ========================= This release fixes a security bug: * sshd(8): fix a memory corruption problem triggered during rekeying when an AES-GCM cipher is selected. Full details of the vulnerability are available at: http://www.openssh.com/txt/gcmrekey.adv Checksums: ========== - SHA1 (openssh-6.4.tar.gz) = 4caf1a50eb3a3da821c16298c4aaa576fe24210c - SHA1 (openssh-6.4p1.tar.gz) = cf5fe0eb118d7e4f9296fbc5d6884965885fc55d Reporting Bugs: =============== - Please read http://www.openssh.com/report.html Security bugs should be reported directly to openssh@openssh.com OpenSSH is brought to you by Markus Friedl, Niels Provos, Theo de Raadt, Kevin Steves, Damien Miller, Darren Tucker, Jason McIntyre, Tim Rice and Ben Lindstrom.
2013-11-08 21:58:08 +04:00
int64_t rekey_limit;
int rekey_interval;
From ftp.openbsd.org
2012-12-12 20:52:18 +04:00
char *version_addendum; /* Appended to SSH banner */
from openbsd
2013-03-29 18:52:38 +04:00
u_int num_auth_methods;
OpenSSH 7.7 was released on 2018-04-02. It is available from the mirrors listed at http://www.openssh.com/ shortly. OpenSSH is a 100% complete SSH protocol 2.0 implementation and includes sftp client and server support. Once again, we would like to thank the OpenSSH community for their continued support of the project, especially those who contributed code or patches, reported bugs, tested snapshots or donated to the project. More information on donations may be found at: http://www.openssh.com/donations.html Potentially-incompatible changes ================================ This release includes a number of changes that may affect existing configurations: * ssh(1)/sshd(8): Drop compatibility support for some very old SSH implementations, including ssh.com <=2.* and OpenSSH <= 3.*. These versions were all released in or before 2001 and predate the final SSH RFCs. The support in question isn't necessary for RFC-compliant SSH implementations. Changes since OpenSSH 7.6 ========================= This is primarily a bugfix release. New Features ------------ * All: Add experimental support for PQC XMSS keys (Extended Hash- Based Signatures) based on the algorithm described in https://tools.ietf.org/html/draft-irtf-cfrg-xmss-hash-based-signatures-12 The XMSS signature code is experimental and not compiled in by default. * sshd(8): Add a "rdomain" criteria for the sshd_config Match keyword to allow conditional configuration that depends on which routing domain a connection was received on (currently supported on OpenBSD and Linux). * sshd_config(5): Add an optional rdomain qualifier to the ListenAddress directive to allow listening on different routing domains. This is supported only on OpenBSD and Linux at present. * sshd_config(5): Add RDomain directive to allow the authenticated session to be placed in an explicit routing domain. This is only supported on OpenBSD at present. * sshd(8): Add "expiry-time" option for authorized_keys files to allow for expiring keys. * ssh(1): Add a BindInterface option to allow binding the outgoing connection to an interface's address (basically a more usable BindAddress) * ssh(1): Expose device allocated for tun/tap forwarding via a new %T expansion for LocalCommand. This allows LocalCommand to be used to prepare the interface. * sshd(8): Expose the device allocated for tun/tap forwarding via a new SSH_TUNNEL environment variable. This allows automatic setup of the interface and surrounding network configuration automatically on the server. * ssh(1)/scp(1)/sftp(1): Add URI support to ssh, sftp and scp, e.g. ssh://user@host or sftp://user@host/path. Additional connection parameters described in draft-ietf-secsh-scp-sftp-ssh-uri-04 are not implemented since the ssh fingerprint format in the draft uses the deprecated MD5 hash with no way to specify the any other algorithm. * ssh-keygen(1): Allow certificate validity intervals that specify only a start or stop time (instead of both or neither). * sftp(1): Allow "cd" and "lcd" commands with no explicit path argument. lcd will change to the local user's home directory as usual. cd will change to the starting directory for session (because the protocol offers no way to obtain the remote user's home directory). bz#2760 * sshd(8): When doing a config test with sshd -T, only require the attributes that are actually used in Match criteria rather than (an incomplete list of) all criteria. Bugfixes -------- * ssh(1)/sshd(8): More strictly check signature types during key exchange against what was negotiated. Prevents downgrade of RSA signatures made with SHA-256/512 to SHA-1. * sshd(8): Fix support for client that advertise a protocol version of "1.99" (indicating that they are prepared to accept both SSHv1 and SSHv2). This was broken in OpenSSH 7.6 during the removal of SSHv1 support. bz#2810 * ssh(1): Warn when the agent returns a ssh-rsa (SHA1) signature when a rsa-sha2-256/512 signature was requested. This condition is possible when an old or non-OpenSSH agent is in use. bz#2799 * ssh-agent(1): Fix regression introduced in 7.6 that caused ssh-agent to fatally exit if presented an invalid signature request message. * sshd_config(5): Accept yes/no flag options case-insensitively, as has been the case in ssh_config(5) for a long time. bz#2664 * ssh(1): Improve error reporting for failures during connection. Under some circumstances misleading errors were being shown. bz#2814 * ssh-keyscan(1): Add -D option to allow printing of results directly in SSHFP format. bz#2821 * regress tests: fix PuTTY interop test broken in last release's SSHv1 removal. bz#2823 * ssh(1): Compatibility fix for some servers that erroneously drop the connection when the IUTF8 (RFC8160) option is sent. * scp(1): Disable RemoteCommand and RequestTTY in the ssh session started by scp (sftp was already doing this.) * ssh-keygen(1): Refuse to create a certificate with an unusable number of principals. * ssh-keygen(1): Fatally exit if ssh-keygen is unable to write all the public key during key generation. Previously it would silently ignore errors writing the comment and terminating newline. * ssh(1): Do not modify hostname arguments that are addresses by automatically forcing them to lower-case. Instead canonicalise them to resolve ambiguities (e.g. ::0001 => ::1) before they are matched against known_hosts. bz#2763 * ssh(1): Don't accept junk after "yes" or "no" responses to hostkey prompts. bz#2803 * sftp(1): Have sftp print a warning about shell cleanliness when decoding the first packet fails, which is usually caused by shells polluting stdout of non-interactive startups. bz#2800 * ssh(1)/sshd(8): Switch timers in packet code from using wall-clock time to monotonic time, allowing the packet layer to better function over a clock step and avoiding possible integer overflows during steps. * Numerous manual page fixes and improvements. Portability ----------- * sshd(8): Correctly detect MIPS ABI in use at configure time. Fixes sandbox violations on some environments. * sshd(8): Remove UNICOS support. The hardware and software are literal museum pieces and support in sshd is too intrusive to justify maintaining. * All: Build and link with "retpoline" flags when available to mitigate the "branch target injection" style (variant 2) of the Spectre branch-prediction vulnerability. * All: Add auto-generated dependency information to Makefile. * Numerous fixed to the RPM spec files. Checksums: ========== - SHA1 (openssh-7.7.tar.gz) = 24812e05fa233014c847c7775748316e7f8a836c - SHA256 (openssh-7.7.tar.gz) = T4ua1L/vgAYqwB0muRahvnm5ZUr3PLY9nPljaG8egvo= - SHA1 (openssh-7.7p1.tar.gz) = 446fe9ed171f289f0d62197dffdbfdaaf21c49f2 - SHA256 (openssh-7.7p1.tar.gz) = 1zvn5oTpnvzQJL4Vowv/y+QbASsvezyQhK7WIXdea48= Please note that the SHA256 signatures are base64 encoded and not hexadecimal (which is the default for most checksum tools). The PGP key used to sign the releases is available as RELEASE_KEY.asc from the mirror sites. Reporting Bugs: =============== - Please read http://www.openssh.com/report.html Security bugs should be reported directly to openssh@openssh.com
2018-04-06 21:56:05 +03:00
char **auth_methods;
Changes since OpenSSH 6.7 ========================= This is a major release, containing a number of new features as well as a large internal re-factoring. Potentially-incompatible changes -------------------------------- * sshd(8): UseDNS now defaults to 'no'. Configurations that match against the client host name (via sshd_config or authorized_keys) may need to re-enable it or convert to matching against addresses. New Features ------------ * Much of OpenSSH's internal code has been re-factored to be more library-like. These changes are mostly not user-visible, but have greatly improved OpenSSH's testability and internal layout. * Add FingerprintHash option to ssh(1) and sshd(8), and equivalent command-line flags to the other tools to control algorithm used for key fingerprints. The default changes from MD5 to SHA256 and format from hex to base64. Fingerprints now have the hash algorithm prepended. An example of the new format: SHA256:mVPwvezndPv/ARoIadVY98vAC0g+P/5633yTC4d/wXE Please note that visual host keys will also be different. * ssh(1), sshd(8): Experimental host key rotation support. Add a protocol extension for a server to inform a client of all its available host keys after authentication has completed. The client may record the keys in known_hosts, allowing it to upgrade to better host key algorithms and a server to gracefully rotate its keys. The client side of this is controlled by a UpdateHostkeys config option (default off). * ssh(1): Add a ssh_config HostbasedKeyType option to control which host public key types are tried during host-based authentication. * ssh(1), sshd(8): fix connection-killing host key mismatch errors when sshd offers multiple ECDSA keys of different lengths. * ssh(1): when host name canonicalisation is enabled, try to parse host names as addresses before looking them up for canonicalisation. fixes bz#2074 and avoiding needless DNS lookups in some cases. * ssh-keygen(1), sshd(8): Key Revocation Lists (KRLs) no longer require OpenSSH to be compiled with OpenSSL support. * ssh(1), ssh-keysign(8): Make ed25519 keys work for host based authentication. * sshd(8): SSH protocol v.1 workaround for the Meyer, et al, Bleichenbacher Side Channel Attack. Fake up a bignum key before RSA decryption. * sshd(8): Remember which public keys have been used for authentication and refuse to accept previously-used keys. This allows AuthenticationMethods=publickey,publickey to require that users authenticate using two _different_ public keys. * sshd(8): add sshd_config HostbasedAcceptedKeyTypes and PubkeyAcceptedKeyTypes options to allow sshd to control what public key types will be accepted. Currently defaults to all. * sshd(8): Don't count partial authentication success as a failure against MaxAuthTries. * ssh(1): Add RevokedHostKeys option for the client to allow text-file or KRL-based revocation of host keys. * ssh-keygen(1), sshd(8): Permit KRLs that revoke certificates by serial number or key ID without scoping to a particular CA. * ssh(1): Add a "Match canonical" criteria that allows ssh_config Match blocks to trigger only in the second config pass. * ssh(1): Add a -G option to ssh that causes it to parse its configuration and dump the result to stdout, similar to "sshd -T". * ssh(1): Allow Match criteria to be negated. E.g. "Match !host". * The regression test suite has been extended to cover more OpenSSH features. The unit tests have been expanded and now cover key exchange. Bugfixes * ssh-keyscan(1): ssh-keyscan has been made much more robust again servers that hang or violate the SSH protocol. * ssh(1), ssh-keygen(1): Fix regression bz#2306: Key path names were being lost as comment fields. * ssh(1): Allow ssh_config Port options set in the second config parse phase to be applied (they were being ignored). bz#2286 * ssh(1): Tweak config re-parsing with host canonicalisation - make the second pass through the config files always run when host name canonicalisation is enabled (and not whenever the host name changes) bz#2267 * ssh(1): Fix passing of wildcard forward bind addresses when connection multiplexing is in use; bz#2324; * ssh-keygen(1): Fix broken private key conversion from non-OpenSSH formats; bz#2345. * ssh-keygen(1): Fix KRL generation bug when multiple CAs are in use. * Various fixes to manual pages: bz#2288, bz#2316, bz#2273 Portable OpenSSH * Support --without-openssl at configure time Disables and removes dependency on OpenSSL. Many features, including SSH protocol 1 are not supported and the set of crypto options is greatly restricted. This will only work on systems with native arc4random or /dev/urandom. Considered highly experimental for now. * Support --without-ssh1 option at configure time Allows disabling support for SSH protocol 1. * sshd(8): Fix compilation on systems with IPv6 support in utmpx; bz#2296 * Allow custom service name for sshd on Cygwin. Permits the use of multiple sshd running with different service names. Checksums: ========== - SHA1 (openssh-6.8.tar.gz) = 99903c6ca76e0a2c044711017f81127e12459d37 - SHA256 (openssh-6.8.tar.gz) = N1uzVarFbrm2CzAwuDu3sRoszmqpK+5phAChP/QNyuw= - SHA1 (openssh-6.8p1.tar.gz) = cdbc51e46a902b30d263b05fdc71340920e91c92 - SHA256 (openssh-6.8p1.tar.gz) = P/ZM5z7hJEgLW/dnuYMNfTwDu8tqvnFrePAZLDfOFg4= Please note that the PGP key used to sign releases was recently rotated. The new key has been signed by the old key to provide continuity. It is available from the mirror sites as RELEASE_KEY.asc. Reporting Bugs: =============== - Please read http://www.openssh.com/report.html Security bugs should be reported directly to openssh@openssh.com OpenSSH is brought to you by Markus Friedl, Niels Provos, Theo de Raadt, Kevin Steves, Damien Miller, Darren Tucker, Jason McIntyre, Tim Rice and Ben Lindstrom.
2015-04-04 02:49:21 +03:00
int fingerprint_hash;
Potentially-incompatible changes ================================ This release includes a number of changes that may affect existing configurations: * ssh(1): delete SSH protocol version 1 support, associated configuration options and documentation. * ssh(1)/sshd(8): remove support for the hmac-ripemd160 MAC. * ssh(1)/sshd(8): remove support for the arcfour, blowfish and CAST ciphers. * Refuse RSA keys <1024 bits in length and improve reporting for keys that do not meet this requirement. * ssh(1): do not offer CBC ciphers by default. Changes since OpenSSH 7.5 ========================= This is primarily a bugfix release. It also contains substantial internal refactoring. Security -------- * sftp-server(8): in read-only mode, sftp-server was incorrectly permitting creation of zero-length files. Reported by Michal Zalewski. New Features ------------ * ssh(1): add RemoteCommand option to specify a command in the ssh config file instead of giving it on the client's command line. This allows the configuration file to specify the command that will be executed on the remote host. * sshd(8): add ExposeAuthInfo option that enables writing details of the authentication methods used (including public keys where applicable) to a file that is exposed via a $SSH_USER_AUTH environment variable in the subsequent session. * ssh(1): add support for reverse dynamic forwarding. In this mode, ssh will act as a SOCKS4/5 proxy and forward connections to destinations requested by the remote SOCKS client. This mode is requested using extended syntax for the -R and RemoteForward options and, because it is implemented solely at the client, does not require the server be updated to be supported. * sshd(8): allow LogLevel directive in sshd_config Match blocks; bz#2717 * ssh-keygen(1): allow inclusion of arbitrary string or flag certificate extensions and critical options. * ssh-keygen(1): allow ssh-keygen to use a key held in ssh-agent as a CA when signing certificates. bz#2377 * ssh(1)/sshd(8): allow IPQoS=none in ssh/sshd to not set an explicit ToS/DSCP value and just use the operating system default. * ssh-add(1): added -q option to make ssh-add quiet on success. * ssh(1): expand the StrictHostKeyChecking option with two new settings. The first "accept-new" will automatically accept hitherto-unseen keys but will refuse connections for changed or invalid hostkeys. This is a safer subset of the current behaviour of StrictHostKeyChecking=no. The second setting "off", is a synonym for the current behaviour of StrictHostKeyChecking=no: accept new host keys, and continue connection for hosts with incorrect hostkeys. A future release will change the meaning of StrictHostKeyChecking=no to the behaviour of "accept-new". bz#2400 * ssh(1): add SyslogFacility option to ssh(1) matching the equivalent option in sshd(8). bz#2705 Bugfixes -------- * ssh(1): use HostKeyAlias if specified instead of hostname for matching host certificate principal names; bz#2728 * sftp(1): implement sorting for globbed ls; bz#2649 * ssh(1): add a user@host prefix to client's "Permission denied" messages, useful in particular when using "stacked" connections (e.g. ssh -J) where it's not clear which host is denying. bz#2720 * ssh(1): accept unknown EXT_INFO extension values that contain \0 characters. These are legal, but would previously cause fatal connection errors if received. * ssh(1)/sshd(8): repair compression statistics printed at connection exit * sftp(1): print '?' instead of incorrect link count (that the protocol doesn't provide) for remote listings. bz#2710 * ssh(1): return failure rather than fatal() for more cases during session multiplexing negotiations. Causes the session to fall back to a non-mux connection if they occur. bz#2707 * ssh(1): mention that the server may send debug messages to explain public key authentication problems under some circumstances; bz#2709 * Translate OpenSSL error codes to better report incorrect passphrase errors when loading private keys; bz#2699 * sshd(8): adjust compatibility patterns for WinSCP to correctly identify versions that implement only the legacy DH group exchange scheme. bz#2748 * ssh(1): print the "Killed by signal 1" message only at LogLevel verbose so that it is not shown at the default level; prevents it from appearing during ssh -J and equivalent ProxyCommand configs. bz#1906, bz#2744 * ssh-keygen(1): when generating all hostkeys (ssh-keygen -A), clobber existing keys if they exist but are zero length. zero-length keys could previously be made if ssh-keygen failed or was interrupted part way through generating them. bz#2561 * ssh(1): fix pledge(2) violation in the escape sequence "~&" used to place the current session in the background. * ssh-keyscan(1): avoid double-close() on file descriptors; bz#2734 * sshd(8): avoid reliance on shared use of pointers shared between monitor and child sshd processes. bz#2704 * sshd_config(8): document available AuthenticationMethods; bz#2453 * ssh(1): avoid truncation in some login prompts; bz#2768 * sshd(8): Fix various compilations failures, inc bz#2767 * ssh(1): make "--" before the hostname terminate argument processing after the hostname too. * ssh-keygen(1): switch from aes256-cbc to aes256-ctr for encrypting new-style private keys. Fixes problems related to private key handling for no-OpenSSL builds. bz#2754 * ssh(1): warn and do not attempt to use keys when the public and private halves do not match. bz#2737 * sftp(1): don't print verbose error message when ssh disconnects from under sftp. bz#2750 * sshd(8): fix keepalive scheduling problem: activity on a forwarded port from preventing the keepalive from being sent; bz#2756 * sshd(8): when started without root privileges, don't require the privilege separation user or path to exist. Makes running the regression tests easier without touching the filesystem. * Make integrity.sh regression tests more robust against timeouts. bz#2658 * ssh(1)/sshd(8): correctness fix for channels implementation: accept channel IDs greater than 0x7FFFFFFF. Portability ----------- * sshd(9): drop two more privileges in the Solaris sandbox: PRIV_DAX_ACCESS and PRIV_SYS_IB_INFO; bz#2723 * sshd(8): expose list of completed authentication methods to PAM via the SSH_AUTH_INFO_0 PAM environment variable. bz#2408 * ssh(1)/sshd(8): fix several problems in the tun/tap forwarding code, mostly to do with host/network byte order confusion. bz#2735 * Add --with-cflags-after and --with-ldflags-after configure flags to allow setting CFLAGS/LDFLAGS after configure has completed. These are useful for setting sanitiser/fuzzing options that may interfere with configure's operation. * sshd(8): avoid Linux seccomp violations on ppc64le over the socketcall syscall. * Fix use of ldns when using ldns-config; bz#2697 * configure: set cache variables when cross-compiling. The cross- compiling fallback message was saying it assumed the test passed, but it wasn't actually set the cache variables and this would cause later tests to fail. * Add clang libFuzzer harnesses for public key parsing and signature verification.
2017-10-07 22:36:11 +03:00
int expose_userauth_info;
Potentially-incompatible changes ================================ This release includes a number of changes that may affect existing configurations: * ssh-keygen(1): write OpenSSH format private keys by default instead of using OpenSSL's PEM format. The OpenSSH format, supported in OpenSSH releases since 2014 and described in the PROTOCOL.key file in the source distribution, offers substantially better protection against offline password guessing and supports key comments in private keys. If necessary, it is possible to write old PEM-style keys by adding "-m PEM" to ssh-keygen's arguments when generating or updating a key. * sshd(8): remove internal support for S/Key multiple factor authentication. S/Key may still be used via PAM or BSD auth. * ssh(1): remove vestigal support for running ssh(1) as setuid. This used to be required for hostbased authentication and the (long gone) rhosts-style authentication, but has not been necessary for a long time. Attempting to execute ssh as a setuid binary, or with uid != effective uid will now yield a fatal error at runtime. * sshd(8): the semantics of PubkeyAcceptedKeyTypes and the similar HostbasedAcceptedKeyTypes options have changed. These now specify signature algorithms that are accepted for their respective authentication mechanism, where previously they specified accepted key types. This distinction matters when using the RSA/SHA2 signature algorithms "rsa-sha2-256", "rsa-sha2-512" and their certificate counterparts. Configurations that override these options but omit these algorithm names may cause unexpected authentication failures (no action is required for configurations that accept the default for these options). * sshd(8): the precedence of session environment variables has changed. ~/.ssh/environment and environment="..." options in authorized_keys files can no longer override SSH_* variables set implicitly by sshd. * ssh(1)/sshd(8): the default IPQoS used by ssh/sshd has changed. They will now use DSCP AF21 for interactive traffic and CS1 for bulk. For a detailed rationale, please see the commit message: https://cvsweb.openbsd.org/src/usr.bin/ssh/readconf.c#rev1.284
2018-08-26 10:39:56 +03:00
u_int64_t timing_secret;
OpenSSH 8.2/8.2p1 (2020-02-14) OpenSSH 8.2 was released on 2020-02-14. It is available from the mirrors listed at https://www.openssh.com/. OpenSSH is a 100% complete SSH protocol 2.0 implementation and includes sftp client and server support. Once again, we would like to thank the OpenSSH community for their continued support of the project, especially those who contributed code or patches, reported bugs, tested snapshots or donated to the project. More information on donations may be found at: https://www.openssh.com/donations.html Future deprecation notice ========================= It is now possible[1] to perform chosen-prefix attacks against the SHA-1 hash algorithm for less than USD$50K. For this reason, we will be disabling the "ssh-rsa" public key signature algorithm that depends on SHA-1 by default in a near-future release. This algorithm is unfortunately still used widely despite the existence of better alternatives, being the only remaining public key signature algorithm specified by the original SSH RFCs. The better alternatives include: * The RFC8332 RSA SHA-2 signature algorithms rsa-sha2-256/512. These algorithms have the advantage of using the same key type as "ssh-rsa" but use the safe SHA-2 hash algorithms. These have been supported since OpenSSH 7.2 and are already used by default if the client and server support them. * The ssh-ed25519 signature algorithm. It has been supported in OpenSSH since release 6.5. * The RFC5656 ECDSA algorithms: ecdsa-sha2-nistp256/384/521. These have been supported by OpenSSH since release 5.7. To check whether a server is using the weak ssh-rsa public key algorithm for host authentication, try to connect to it after removing the ssh-rsa algorithm from ssh(1)'s allowed list: ssh -oHostKeyAlgorithms=-ssh-rsa user@host If the host key verification fails and no other supported host key types are available, the server software on that host should be upgraded. A future release of OpenSSH will enable UpdateHostKeys by default to allow the client to automatically migrate to better algorithms. Users may consider enabling this option manually. [1] "SHA-1 is a Shambles: First Chosen-Prefix Collision on SHA-1 and Application to the PGP Web of Trust" Leurent, G and Peyrin, T (2020) https://eprint.iacr.org/2020/014.pdf Security ======== * ssh(1), sshd(8), ssh-keygen(1): this release removes the "ssh-rsa" (RSA/SHA1) algorithm from those accepted for certificate signatures (i.e. the client and server CASignatureAlgorithms option) and will use the rsa-sha2-512 signature algorithm by default when the ssh-keygen(1) CA signs new certificates. Certificates are at special risk to the aforementioned SHA1 collision vulnerability as an attacker has effectively unlimited time in which to craft a collision that yields them a valid certificate, far more than the relatively brief LoginGraceTime window that they have to forge a host key signature. The OpenSSH certificate format includes a CA-specified (typically random) nonce value near the start of the certificate that should make exploitation of chosen-prefix collisions in this context challenging, as the attacker does not have full control over the prefix that actually gets signed. Nonetheless, SHA1 is now a demonstrably broken algorithm and futher improvements in attacks are highly likely. OpenSSH releases prior to 7.2 do not support the newer RSA/SHA2 algorithms and will refuse to accept certificates signed by an OpenSSH 8.2+ CA using RSA keys unless the unsafe algorithm is explicitly selected during signing ("ssh-keygen -t ssh-rsa"). Older clients/servers may use another CA key type such as ssh-ed25519 (supported since OpenSSH 6.5) or one of the ecdsa-sha2-nistp256/384/521 types (supported since OpenSSH 5.7) instead if they cannot be upgraded. Potentially-incompatible changes ================================ This release includes a number of changes that may affect existing configurations: * ssh(1), sshd(8): the above removal of "ssh-rsa" from the accepted CASignatureAlgorithms list. * ssh(1), sshd(8): this release removes diffie-hellman-group14-sha1 from the default key exchange proposal for both the client and server. * ssh-keygen(1): the command-line options related to the generation and screening of safe prime numbers used by the diffie-hellman-group-exchange-* key exchange algorithms have changed. Most options have been folded under the -O flag. * sshd(8): the sshd listener process title visible to ps(1) has changed to include information about the number of connections that are currently attempting authentication and the limits configured by MaxStartups. * ssh-sk-helper(8): this is a new binary. It is used by the FIDO/U2F support to provide address-space isolation for token middleware libraries (including the internal one). It needs to be installed in the expected path, typically under /usr/libexec or similar. Changes since OpenSSH 8.1 ========================= This release contains some significant new features. FIDO/U2F Support ---------------- This release adds support for FIDO/U2F hardware authenticators to OpenSSH. U2F/FIDO are open standards for inexpensive two-factor authentication hardware that are widely used for website authentication. In OpenSSH FIDO devices are supported by new public key types "ecdsa-sk" and "ed25519-sk", along with corresponding certificate types. ssh-keygen(1) may be used to generate a FIDO token-backed key, after which they may be used much like any other key type supported by OpenSSH, so long as the hardware token is attached when the keys are used. FIDO tokens also generally require the user explicitly authorise operations by touching or tapping them. Generating a FIDO key requires the token be attached, and will usually require the user tap the token to confirm the operation: $ ssh-keygen -t ecdsa-sk -f ~/.ssh/id_ecdsa_sk Generating public/private ecdsa-sk key pair. You may need to touch your security key to authorize key generation. Enter file in which to save the key (/home/djm/.ssh/id_ecdsa_sk): Enter passphrase (empty for no passphrase): Enter same passphrase again: Your identification has been saved in /home/djm/.ssh/id_ecdsa_sk Your public key has been saved in /home/djm/.ssh/id_ecdsa_sk.pub This will yield a public and private key-pair. The private key file should be useless to an attacker who does not have access to the physical token. After generation, this key may be used like any other supported key in OpenSSH and may be listed in authorized_keys, added to ssh-agent(1), etc. The only additional stipulation is that the FIDO token that the key belongs to must be attached when the key is used. FIDO tokens are most commonly connected via USB but may be attached via other means such as Bluetooth or NFC. In OpenSSH, communication with the token is managed via a middleware library, specified by the SecurityKeyProvider directive in ssh/sshd_config(5) or the $SSH_SK_PROVIDER environment variable for ssh-keygen(1) and ssh-add(1). The API for this middleware is documented in the sk-api.h and PROTOCOL.u2f files in the source distribution. OpenSSH includes a middleware ("SecurityKeyProvider=internal") with support for USB tokens. It is automatically enabled in OpenBSD and may be enabled in portable OpenSSH via the configure flag --with-security-key-builtin. If the internal middleware is enabled then it is automatically used by default. This internal middleware requires that libfido2 (https://github.com/Yubico/libfido2) and its dependencies be installed. We recommend that packagers of portable OpenSSH enable the built-in middleware, as it provides the lowest-friction experience for users. Note: FIDO/U2F tokens are required to implement the ECDSA-P256 "ecdsa-sk" key type, but hardware support for Ed25519 "ed25519-sk" is less common. Similarly, not all hardware tokens support some of the optional features such as resident keys. The protocol-level changes to support FIDO/U2F keys in SSH are documented in the PROTOCOL.u2f file in the OpenSSH source distribution. There are a number of supporting changes to this feature: * ssh-keygen(1): add a "no-touch-required" option when generating FIDO-hosted keys, that disables their default behaviour of requiring a physical touch/tap on the token during authentication. Note: not all tokens support disabling the touch requirement. * sshd(8): add a sshd_config PubkeyAuthOptions directive that collects miscellaneous public key authentication-related options for sshd(8). At present it supports only a single option "no-touch-required". This causes sshd to skip its default check for FIDO/U2F keys that the signature was authorised by a touch or press event on the token hardware. * ssh(1), sshd(8), ssh-keygen(1): add a "no-touch-required" option for authorized_keys and a similar extension for certificates. This option disables the default requirement that FIDO key signatures attest that the user touched their key to authorize them, mirroring the similar PubkeyAuthOptions sshd_config option. * ssh-keygen(1): add support for the writing the FIDO attestation information that is returned when new keys are generated via the "-O write-attestation=/path" option. FIDO attestation certificates may be used to verify that a FIDO key is hosted in trusted hardware. OpenSSH does not currently make use of this information, beyond optionally writing it to disk. FIDO2 resident keys ------------------- FIDO/U2F OpenSSH keys consist of two parts: a "key handle" part stored in the private key file on disk, and a per-device private key that is unique to each FIDO/U2F token and that cannot be exported from the token hardware. These are combined by the hardware at authentication time to derive the real key that is used to sign authentication challenges. For tokens that are required to move between computers, it can be cumbersome to have to move the private key file first. To avoid this requirement, tokens implementing the newer FIDO2 standard support "resident keys", where it is possible to effectively retrieve the key handle part of the key from the hardware. OpenSSH supports this feature, allowing resident keys to be generated using the ssh-keygen(1) "-O resident" flag. This will produce a public/private key pair as usual, but it will be possible to retrieve the private key part from the token later. This may be done using "ssh-keygen -K", which will download all available resident keys from the tokens attached to the host and write public/private key files for them. It is also possible to download and add resident keys directly to ssh-agent(1) without writing files to the file-system using "ssh-add -K". Resident keys are indexed on the token by the application string and user ID. By default, OpenSSH uses an application string of "ssh:" and an empty user ID. If multiple resident keys on a single token are desired then it may be necessary to override one or both of these defaults using the ssh-keygen(1) "-O application=" or "-O user=" options. Note: OpenSSH will only download and use resident keys whose application string begins with "ssh:" Storing both parts of a key on a FIDO token increases the likelihood of an attacker being able to use a stolen token device. For this reason, tokens should enforce PIN authentication before allowing download of keys, and users should set a PIN on their tokens before creating any resident keys. Other New Features ------------------ * sshd(8): add an Include sshd_config keyword that allows including additional configuration files via glob(3) patterns. bz2468 * ssh(1)/sshd(8): make the LE (low effort) DSCP code point available via the IPQoS directive; bz2986, * ssh(1): when AddKeysToAgent=yes is set and the key contains no comment, add the key to the agent with the key's path as the comment. bz2564 * ssh-keygen(1), ssh-agent(1): expose PKCS#11 key labels and X.509 subjects as key comments, rather than simply listing the PKCS#11 provider library path. PR138 * ssh-keygen(1): allow PEM export of DSA and ECDSA keys; bz3091 * ssh(1), sshd(8): make zlib compile-time optional, available via the Makefile.inc ZLIB flag on OpenBSD or via the --with-zlib configure option for OpenSSH portable. * sshd(8): when clients get denied by MaxStartups, send a notification prior to the SSH2 protocol banner according to RFC4253 section 4.2. * ssh(1), ssh-agent(1): when invoking the $SSH_ASKPASS prompt program, pass a hint to the program to describe the type of desired prompt. The possible values are "confirm" (indicating that a yes/no confirmation dialog with no text entry should be shown), "none" (to indicate an informational message only), or blank for the original ssh-askpass behaviour of requesting a password/phrase. * ssh(1): allow forwarding a different agent socket to the path specified by $SSH_AUTH_SOCK, by extending the existing ForwardAgent option to accepting an explicit path or the name of an environment variable in addition to yes/no. * ssh-keygen(1): add a new signature operations "find-principals" to look up the principal associated with a signature from an allowed- signers file. * sshd(8): expose the number of currently-authenticating connections along with the MaxStartups limit in the process title visible to "ps". Bugfixes -------- * sshd(8): make ClientAliveCountMax=0 have sensible semantics: it will now disable connection killing entirely rather than the current behaviour of instantly killing the connection after the first liveness test regardless of success. bz2627 * sshd(8): clarify order of AllowUsers / DenyUsers vs AllowGroups / DenyGroups in the sshd(8) manual page. bz1690 * sshd(8): better describe HashKnownHosts in the manual page. bz2560 * sshd(8): clarify that that permitopen=/PermitOpen do no name or address translation in the manual page. bz3099 * sshd(8): allow the UpdateHostKeys feature to function when multiple known_hosts files are in use. When updating host keys, ssh will now search subsequent known_hosts files, but will add updated host keys to the first specified file only. bz2738 * All: replace all calls to signal(2) with a wrapper around sigaction(2). This wrapper blocks all other signals during the handler preventing races between handlers, and sets SA_RESTART which should reduce the potential for short read/write operations. * sftp(1): fix a race condition in the SIGCHILD handler that could turn in to a kill(-1); bz3084 * sshd(8): fix a case where valid (but extremely large) SSH channel IDs were being incorrectly rejected. bz3098 * ssh(1): when checking host key fingerprints as answers to new hostkey prompts, ignore whitespace surrounding the fingerprint itself. * All: wait for file descriptors to be readable or writeable during non-blocking connect, not just readable. Prevents a timeout when the server doesn't immediately send a banner (e.g. multiplexers like sslh) * sshd_config(5): document the sntrup4591761x25519-sha512@tinyssh.org key exchange algorithm. PR#151
2020-02-27 03:21:35 +03:00
char *sk_provider;
Import OpenSSH-9.1 (previously we were on OpenSSH-9.0) This release is focused on bug fixing. Security ======== This release contains fixes for three minor memory safety problems. None are believed to be exploitable, but we report most memory safety problems as potential security vulnerabilities out of caution. * ssh-keyscan(1): fix a one-byte overflow in SSH- banner processing. Reported by Qualys * ssh-keygen(1): double free() in error path of file hashing step in signing/verify code; GHPR333 * ssh-keysign(8): double-free in error path introduced in openssh-8.9 Potentially-incompatible changes -------------------------------- * The portable OpenSSH project now signs commits and release tags using git's recent SSH signature support. The list of developer signing keys is included in the repository as .git_allowed_signers and is cross-signed using the PGP key that is still used to sign release artifacts: https://cdn.openbsd.org/pub/OpenBSD/OpenSSH/RELEASE_KEY.asc * ssh(1), sshd(8): SetEnv directives in ssh_config and sshd_config are now first-match-wins to match other directives. Previously if an environment variable was multiply specified the last set value would have been used. bz3438 * ssh-keygen(8): ssh-keygen -A (generate all default host key types) will no longer generate DSA keys, as these are insecure and have not been used by default for some years. New features ------------ * ssh(1), sshd(8): add a RequiredRSASize directive to set a minimum RSA key length. Keys below this length will be ignored for user authentication and for host authentication in sshd(8). ssh(1) will terminate a connection if the server offers an RSA key that falls below this limit, as the SSH protocol does not include the ability to retry a failed key exchange. * sftp-server(8): add a "users-groups-by-id@openssh.com" extension request that allows the client to obtain user/group names that correspond to a set of uids/gids. * sftp(1): use "users-groups-by-id@openssh.com" sftp-server extension (when available) to fill in user/group names for directory listings. * sftp-server(8): support the "home-directory" extension request defined in draft-ietf-secsh-filexfer-extensions-00. This overlaps a bit with the existing "expand-path@openssh.com", but some other clients support it. * ssh-keygen(1), sshd(8): allow certificate validity intervals, sshsig verification times and authorized_keys expiry-time options to accept dates in the UTC time zone in addition to the default of interpreting them in the system time zone. YYYYMMDD and YYMMDDHHMM[SS] dates/times will be interpreted as UTC if suffixed with a 'Z' character. Also allow certificate validity intervals to be specified in raw seconds-since-epoch as hex value, e.g. -V 0x1234:0x4567890. This is intended for use by regress tests and other tools that call ssh-keygen as part of a CA workflow. bz3468 * sftp(1): allow arguments to the sftp -D option, e.g. sftp -D "/usr/libexec/sftp-server -el debug3" * ssh-keygen(1): allow the existing -U (use agent) flag to work with "-Y sign" operations, where it will be interpreted to require that the private keys is hosted in an agent; bz3429 Bugfixes -------- * ssh-keygen(1): implement the "verify-required" certificate option. This was already documented when support for user-verified FIDO keys was added, but the ssh-keygen(1) code was missing. * ssh-agent(1): hook up the restrict_websafe command-line flag; previously the flag was accepted but never actually used. * sftp(1): improve filename tab completions: never try to complete names to non-existent commands, and better match the completion type (local or remote filename) against the argument position being completed. * ssh-keygen(1), ssh(1), ssh-agent(1): several fixes to FIDO key handling, especially relating to keys that request user-verification. These should reduce the number of unnecessary PIN prompts for keys that support intrinsic user verification. GHPR302, GHPR329 * ssh-keygen(1): when enrolling a FIDO resident key, check if a credential with matching application and user ID strings already exists and, if so, prompt the user for confirmation before overwriting the credential. GHPR329 * sshd(8): improve logging of errors when opening authorized_keys files. bz2042 * ssh(1): avoid multiplexing operations that could cause SIGPIPE from causing the client to exit early. bz3454 * ssh_config(5), sshd_config(5): clarify that the RekeyLimit directive applies to both transmitted and received data. GHPR328 * ssh-keygen(1): avoid double fclose() in error path. * sshd(8): log an error if pipe() fails while accepting a connection. bz3447 * ssh(1), ssh-keygen(1): fix possible NULL deref when built without FIDO support. bz3443 * ssh-keyscan(1): add missing *-sk types to ssh-keyscan manpage. GHPR294. * sshd(8): ensure that authentication passwords are cleared from memory in error paths. GHPR286 * ssh(1), ssh-agent(1): avoid possibility of notifier code executing kill(-1). GHPR286 * ssh_config(5): note that the ProxyJump directive also accepts the same tokens as ProxyCommand. GHPR305. * scp(1): do not not ftruncate(3) files early when in sftp mode. The previous behaviour of unconditionally truncating the destination file would cause "scp ~/foo localhost:foo" and the reverse "scp localhost:foo ~/foo" to delete all the contents of their destination. bz3431 * ssh-keygen(1): improve error message when 'ssh-keygen -Y sign' is unable to load a private key; bz3429 * sftp(1), scp(1): when performing operations that glob(3) a remote path, ensure that the implicit working directory used to construct that path escapes glob(3) characters. This prevents glob characters from being processed in places they shouldn't, e.g. "cd /tmp/a*/", "get *.txt" should have the get operation treat the path "/tmp/a*" literally and not attempt to expand it. * ssh(1), sshd(8): be stricter in which characters will be accepted in specifying a mask length; allow only 0-9. GHPR278 * ssh-keygen(1): avoid printing hash algorithm twice when dumping a KRL * ssh(1), sshd(8): continue running local I/O for open channels during SSH transport rekeying. This should make ~-escapes work in the client (e.g. to exit) if the connection happened to have stalled during a rekey event. * ssh(1), sshd(8): avoid potential poll() spin during rekeying * Further hardening for sshbuf internals: disallow "reparenting" a hierarchical sshbuf and zero the entire buffer if reallocation fails. GHPR287 Portability ----------- * ssh(1), ssh-keygen(1), sshd(8): automatically enable the built-in FIDO security key support if libfido2 is found and usable, unless --without-security-key-builtin was requested. * ssh(1), ssh-keygen(1), sshd(8): many fixes to make the WinHello FIDO device usable on Cygwin. The windows://hello FIDO device will be automatically used by default on this platform unless requested otherwise, or when probing resident FIDO credentials (an operation not currently supported by WinHello). * Portable OpenSSH: remove workarounds for obsolete and unsupported versions of OpenSSL libcrypto. In particular, this release removes fallback support for OpenSSL that lacks AES-CTR or AES-GCM. Those AES cipher modes were added to OpenSSL prior to the minimum version currently supported by OpenSSH, so this is not expected to impact any currently supported configurations. * sshd(8): fix SANDBOX_SECCOMP_FILTER_DEBUG on current Linux/glibc * All: resync and clean up internal CSPRNG code. * scp(1), sftp(1), sftp-server(8): avoid linking these programs with unnecessary libraries. They are no longer linked against libz and libcrypto. This may be of benefit to space constrained systems using any of those components in isolation. * sshd(8): add AUDIT_ARCH_PPC to supported seccomp sandbox architectures. * configure: remove special casing of crypt(). configure will no longer search for crypt() in libcrypto, as it was removed from there years ago. configure will now only search libc and libcrypt. * configure: refuse to use OpenSSL 3.0.4 due to potential RCE in its RSA implementation (CVE-2022-2274) on x86_64. * All: request 1.1x API compatibility for OpenSSL >=3.x; GHPR322 * ssh(1), ssh-keygen(1), sshd(8): fix a number of missing includes required by the XMSS code on some platforms. * sshd(8): cache timezone data in capsicum sandbox.
2022-10-06 01:35:32 +03:00
int required_rsa_size; /* minimum size of RSA keys */
Import OpenSSH 9.3 + the fix from p2 for the PKCS#11 remote provider The previous version was OpenSSH 9.1 OpenSSH 9.3p2 (2023-07-19) OpenSSH 9.3p2 was released on 2023-07-19. It is available from the mirrors listed at https://www.openssh.com/. OpenSSH is a 100% complete SSH protocol 2.0 implementation and includes sftp client and server support. Once again, we would like to thank the OpenSSH community for their continued support of the project, especially those who contributed code or patches, reported bugs, tested snapshots or donated to the project. More information on donations may be found at: https://www.openssh.com/donations.html Changes since OpenSSH 9.3 ========================= This release fixes a security bug. Security ======== Fix CVE-2023-38408 - a condition where specific libaries loaded via ssh-agent(1)'s PKCS#11 support could be abused to achieve remote code execution via a forwarded agent socket if the following conditions are met: * Exploitation requires the presence of specific libraries on the victim system. * Remote exploitation requires that the agent was forwarded to an attacker-controlled system. Exploitation can also be prevented by starting ssh-agent(1) with an empty PKCS#11/FIDO allowlist (ssh-agent -P '') or by configuring an allowlist that contains only specific provider libraries. This vulnerability was discovered and demonstrated to be exploitable by the Qualys Security Advisory team. In addition to removing the main precondition for exploitation, this release removes the ability for remote ssh-agent(1) clients to load PKCS#11 modules by default (see below). Potentially-incompatible changes -------------------------------- * ssh-agent(8): the agent will now refuse requests to load PKCS#11 modules issued by remote clients by default. A flag has been added to restore the previous behaviour "-Oallow-remote-pkcs11". Note that ssh-agent(8) depends on the SSH client to identify requests that are remote. The OpenSSH >=8.9 ssh(1) client does this, but forwarding access to an agent socket using other tools may circumvent this restriction. Checksums: ========== - SHA1 (openssh-9.3p2.tar.gz) = 219cf700c317f400bb20b001c0406056f7188ea4 - SHA256 (openssh-9.3p2.tar.gz) = IA6+FH9ss/EB/QzfngJEKvfdyimN/9n0VoeOfMrGdug= Please note that the SHA256 signatures are base64 encoded and not hexadecimal (which is the default for most checksum tools). The PGP key used to sign the releases is available from the mirror sites: https://cdn.openbsd.org/pub/OpenBSD/OpenSSH/RELEASE_KEY.asc Reporting Bugs: =============== - Please read https://www.openssh.com/report.html Security bugs should be reported directly to openssh@openssh.com OpenSSH 9.3/9.3p1 (2023-03-15) OpenSSH 9.3 was released on 2023-03-15. It is available from the mirrors listed at https://www.openssh.com/. OpenSSH is a 100% complete SSH protocol 2.0 implementation and includes sftp client and server support. Once again, we would like to thank the OpenSSH community for their continued support of the project, especially those who contributed code or patches, reported bugs, tested snapshots or donated to the project. More information on donations may be found at: https://www.openssh.com/donations.html Changes since OpenSSH 9.2 ========================= This release fixes a number of security bugs. Security ======== This release contains fixes for a security problem and a memory safety problem. The memory safety problem is not believed to be exploitable, but we report most network-reachable memory faults as security bugs. * ssh-add(1): when adding smartcard keys to ssh-agent(1) with the per-hop destination constraints (ssh-add -h ...) added in OpenSSH 8.9, a logic error prevented the constraints from being communicated to the agent. This resulted in the keys being added without constraints. The common cases of non-smartcard keys and keys without destination constraints are unaffected. This problem was reported by Luci Stanescu. * ssh(1): Portable OpenSSH provides an implementation of the getrrsetbyname(3) function if the standard library does not provide it, for use by the VerifyHostKeyDNS feature. A specifically crafted DNS response could cause this function to perform an out-of-bounds read of adjacent stack data, but this condition does not appear to be exploitable beyond denial-of- service to the ssh(1) client. The getrrsetbyname(3) replacement is only included if the system's standard library lacks this function and portable OpenSSH was not compiled with the ldns library (--with-ldns). getrrsetbyname(3) is only invoked if using VerifyHostKeyDNS to fetch SSHFP records. This problem was found by the Coverity static analyzer. New features ------------ * ssh-keygen(1), ssh-keyscan(1): accept -Ohashalg=sha1|sha256 when outputting SSHFP fingerprints to allow algorithm selection. bz3493 * sshd(8): add a `sshd -G` option that parses and prints the effective configuration without attempting to load private keys and perform other checks. This allows usage of the option before keys have been generated and for configuration evaluation and verification by unprivileged users. Bugfixes -------- * scp(1), sftp(1): fix progressmeter corruption on wide displays; bz3534 * ssh-add(1), ssh-keygen(1): use RSA/SHA256 when testing usability of private keys as some systems are starting to disable RSA/SHA1 in libcrypto. * sftp-server(8): fix a memory leak. GHPR363 * ssh(1), sshd(8), ssh-keyscan(1): remove vestigal protocol compatibility code and simplify what's left. * Fix a number of low-impact Coverity static analysis findings. These include several reported via bz2687 * ssh_config(5), sshd_config(5): mention that some options are not first-match-wins. * Rework logging for the regression tests. Regression tests will now capture separate logs for each ssh and sshd invocation in a test. * ssh(1): make `ssh -Q CASignatureAlgorithms` work as the manpage says it should; bz3532. * ssh(1): ensure that there is a terminating newline when adding a new entry to known_hosts; bz3529 Portability ----------- * sshd(8): harden Linux seccomp sandbox. Move to an allowlist of mmap(2), madvise(2) and futex(2) flags, removing some concerning kernel attack surface. * sshd(8): improve Linux seccomp-bpf sandbox for older systems; bz3537 Checksums: ========== - SHA1 (openssh-9.3.tar.gz) = 5f9d2f73ddfe94f3f0a78bdf46704b6ad7b66ec7 - SHA256 (openssh-9.3.tar.gz) = eRcXkFZByz70DUBUcyIdvU0pVxP2X280FrmV8pyUdrk= - SHA1 (openssh-9.3p1.tar.gz) = 610959871bf8d6baafc3525811948f85b5dd84ab - SHA256 (openssh-9.3p1.tar.gz) = 6bq6dwGnalHz2Fpiw4OjydzZf6kAuFm8fbEUwYaK+Kg= Please note that the SHA256 signatures are base64 encoded and not hexadecimal (which is the default for most checksum tools). The PGP key used to sign the releases is available from the mirror sites: https://cdn.openbsd.org/pub/OpenBSD/OpenSSH/RELEASE_KEY.asc Reporting Bugs: =============== - Please read https://www.openssh.com/report.html Security bugs should be reported directly to openssh@openssh.com OpenSSH 9.2/9.2p1 (2023-02-02) OpenSSH 9.2 was released on 2023-02-02. It is available from the mirrors listed at https://www.openssh.com/. OpenSSH is a 100% complete SSH protocol 2.0 implementation and includes sftp client and server support. Once again, we would like to thank the OpenSSH community for their continued support of the project, especially those who contributed code or patches, reported bugs, tested snapshots or donated to the project. More information on donations may be found at: https://www.openssh.com/donations.html Changes since OpenSSH 9.1 ========================= This release fixes a number of security bugs. Security ======== This release contains fixes for two security problems and a memory safety problem. The memory safety problem is not believed to be exploitable, but we report most network-reachable memory faults as security bugs. * sshd(8): fix a pre-authentication double-free memory fault introduced in OpenSSH 9.1. This is not believed to be exploitable, and it occurs in the unprivileged pre-auth process that is subject to chroot(2) and is further sandboxed on most major platforms. * ssh(8): in OpenSSH releases after 8.7, the PermitRemoteOpen option would ignore its first argument unless it was one of the special keywords "any" or "none", causing the permission list to fail open if only one permission was specified. bz3515 * ssh(1): if the CanonicalizeHostname and CanonicalizePermittedCNAMEs options were enabled, and the system/libc resolver did not check that names in DNS responses were valid, then use of these options could allow an attacker with control of DNS to include invalid characters (possibly including wildcards) in names added to known_hosts files when they were updated. These names would still have to match the CanonicalizePermittedCNAMEs allow-list, so practical exploitation appears unlikely. Potentially-incompatible changes -------------------------------- * ssh(1): add a new EnableEscapeCommandline ssh_config(5) option that controls whether the client-side ~C escape sequence that provides a command-line is available. Among other things, the ~C command-line could be used to add additional port-forwards at runtime. This option defaults to "no", disabling the ~C command-line that was previously enabled by default. Turning off the command-line allows platforms that support sandboxing of the ssh(1) client (currently only OpenBSD) to use a stricter default sandbox policy. New features ------------ * sshd(8): add support for channel inactivity timeouts via a new sshd_config(5) ChannelTimeout directive. This allows channels that have not seen traffic in a configurable interval to be automatically closed. Different timeouts may be applied to session, X11, agent and TCP forwarding channels. * sshd(8): add a sshd_config UnusedConnectionTimeout option to terminate client connections that have no open channels for a length of time. This complements the ChannelTimeout option above. * sshd(8): add a -V (version) option to sshd like the ssh client has. * ssh(1): add a "Host" line to the output of ssh -G showing the original hostname argument. bz3343 * scp(1), sftp(1): add a -X option to both scp(1) and sftp(1) to allow control over some SFTP protocol parameters: the copy buffer length and the number of in-flight requests, both of which are used during upload/download. Previously these could be controlled in sftp(1) only. This makes them available in both SFTP protocol clients using the same option character sequence. * ssh-keyscan(1): allow scanning of complete CIDR address ranges, e.g. "ssh-keyscan 192.168.0.0/24". If a CIDR range is passed, then it will be expanded to all possible addresses in the range including the all-0s and all-1s addresses. bz#976 * ssh(1): support dynamic remote port forwarding in escape command-line's -R processing. bz#3499 Bugfixes -------- * ssh(1): when restoring non-blocking mode to stdio fds, restore exactly the flags that ssh started with and don't just clobber them with zero, as this could also remove the append flag from the set. bz3523 * ssh(1): avoid printf("%s", NULL) if using UserKnownHostsFile=none and a hostkey in one of the system known hosts file changes. * scp(1): switch scp from using pipes to a socket-pair for communication with its ssh sub-processes, matching how sftp(1) operates. * sshd(8): clear signal mask early in main(); sshd may have been started with one or more signals masked (sigprocmask(2) is not cleared on fork/exec) and this could interfere with various things, e.g. the login grace timer. Execution environments that fail to clear the signal mask before running sshd are clearly broken, but apparently they do exist. * ssh(1): warn if no host keys for hostbased auth can be loaded. * sshd(8): Add server debugging for hostbased auth that is queued and sent to the client after successful authentication, but also logged to assist in diagnosis of HostbasedAuthentication problems. bz3507 * ssh(1): document use of the IdentityFile option as being usable to list public keys as well as private keys. GHPR352 * sshd(8): check for and disallow MaxStartups values less than or equal to zero during config parsing, rather than failing later at runtime. bz3489 * ssh-keygen(1): fix parsing of hex cert expiry times specified on the command-line when acting as a CA. * scp(1): when scp(1) is using the SFTP protocol for transport (the default), better match scp/rcp's handling of globs that don't match the globbed characters but do match literally (e.g. trying to transfer a file named "foo.[1]"). Previously scp(1) in SFTP mode would not match these pathnames but legacy scp/rcp mode would. bz3488 * ssh-agent(1): document the "-O no-restrict-websafe" command-line option. * ssh(1): honour user's umask(2) if it is more restrictive then the ssh default (022). Portability ----------- * sshd(8): allow writev(2) in the Linux seccomp sandbox. This seems to be used by recent glibcs at least in some configurations during error conditions. bz3512. * sshd(8): simply handling of SSH_CONNECTION PAM env var, removing global variable and checking the return value from pam_putenv. bz3508 * sshd(8): disable SANDBOX_SECCOMP_FILTER_DEBUG that was mistakenly enabled during the OpenSSH 9.1 release cycle. * misc: update autotools and regenerate the config files using the latest autotools * all: use -fzero-call-used-regs=used on clang 15 instead of -fzero-call-used-reg=all, as some versions of clang 15 have miscompile code when it was enabled. bz3475 * sshd(8): defer PRNG seeding until after the initial closefrom(2) call. PRNG seeding will initialize OpenSSL, and some engine providers (e.g. Intel's QAT) will open descriptors for their own use that closefrom(2) could clobber. bz3483 * misc: in the poll(2)/ppoll(2) compatibility code, avoid assuming the layout of fd_set. * sftp-server(8), ssh-agent(1): fix ptrace(2) disabling on older FreeBSD kernels. Some versions do not support using id 0 to refer to the current PID for procctl, so try again with getpid() explicitly before failing. * configure.ac: fix -Wstrict-prototypes in configure test code. Clang 16 now warns on this and legacy prototypes will be removed in C23. GHPR355 * configure.ac: fix setres*id checks to work with clang-16. glibc has the prototypes for setresuid behind _GNU_SOURCE, and clang 16 will error out on implicit function definitions. bz3497 Checksums: ========== - SHA1 (openssh-9.2.tar.gz) = e4b806b7c81b87d6c90afe97b3d016ba6cf3ba1c - SHA256 (openssh-9.2.tar.gz) = yYe9uaaWSeetXGXOxuaaEiIsLnvITmGW+l5dgMZb9QU= - SHA1 (openssh-9.2p1.tar.gz) = 3b172b8e971773a7018bbf3231f6589ae539ca4b - SHA256 (openssh-9.2p1.tar.gz) = P2bb8WVftF9Q4cVtpiqwEhjCKIB7ITONY068351xz0Y= Please note that the SHA256 signatures are base64 encoded and not hexadecimal (which is the default for most checksum tools). The PGP key used to sign the releases is available from the mirror sites: https://cdn.openbsd.org/pub/OpenBSD/OpenSSH/RELEASE_KEY.asc Reporting Bugs: =============== - Please read https://www.openssh.com/report.html Security bugs should be reported directly to openssh@openssh.com
2023-07-26 20:31:29 +03:00
char **channel_timeouts; /* inactivity timeout by channel type */
u_int num_channel_timeouts;
int unused_connection_timeout;
import 5.2 from ftp.openbsd.org
2009-06-08 02:19:00 +04:00
} ServerOptions;
From ftp.openbsd.org
2012-12-12 20:52:18 +04:00
/* Information about the incoming connection as used by Match */
struct connection_info {
const char *user;
const char *host; /* possibly resolved hostname */
Import OpenSSH-8.6: Future deprecation notice ========================= It is now possible[1] to perform chosen-prefix attacks against the SHA-1 algorithm for less than USD$50K. In the SSH protocol, the "ssh-rsa" signature scheme uses the SHA-1 hash algorithm in conjunction with the RSA public key algorithm. OpenSSH will disable this signature scheme by default in the near future. Note that the deactivation of "ssh-rsa" signatures does not necessarily require cessation of use for RSA keys. In the SSH protocol, keys may be capable of signing using multiple algorithms. In particular, "ssh-rsa" keys are capable of signing using "rsa-sha2-256" (RSA/SHA256), "rsa-sha2-512" (RSA/SHA512) and "ssh-rsa" (RSA/SHA1). Only the last of these is being turned off by default. This algorithm is unfortunately still used widely despite the existence of better alternatives, being the only remaining public key signature algorithm specified by the original SSH RFCs that is still enabled by default. The better alternatives include: * The RFC8332 RSA SHA-2 signature algorithms rsa-sha2-256/512. These algorithms have the advantage of using the same key type as "ssh-rsa" but use the safe SHA-2 hash algorithms. These have been supported since OpenSSH 7.2 and are already used by default if the client and server support them. * The RFC8709 ssh-ed25519 signature algorithm. It has been supported in OpenSSH since release 6.5. * The RFC5656 ECDSA algorithms: ecdsa-sha2-nistp256/384/521. These have been supported by OpenSSH since release 5.7. To check whether a server is using the weak ssh-rsa public key algorithm, for host authentication, try to connect to it after removing the ssh-rsa algorithm from ssh(1)'s allowed list: ssh -oHostKeyAlgorithms=-ssh-rsa user@host If the host key verification fails and no other supported host key types are available, the server software on that host should be upgraded. OpenSSH recently enabled the UpdateHostKeys option by default to assist the client by automatically migrating to better algorithms. [1] "SHA-1 is a Shambles: First Chosen-Prefix Collision on SHA-1 and Application to the PGP Web of Trust" Leurent, G and Peyrin, T (2020) https://eprint.iacr.org/2020/014.pdf Security ======== * sshd(8): OpenSSH 8.5 introduced the LogVerbose keyword. When this option was enabled with a set of patterns that activated logging in code that runs in the low-privilege sandboxed sshd process, the log messages were constructed in such a way that printf(3) format strings could effectively be specified the low-privilege code. An attacker who had sucessfully exploited the low-privilege process could use this to escape OpenSSH's sandboxing and attack the high-privilege process. Exploitation of this weakness is highly unlikely in practice as the LogVerbose option is not enabled by default and is typically only used for debugging. No vulnerabilities in the low-privilege process are currently known to exist. Thanks to Ilja Van Sprundel for reporting this bug. Changes since OpenSSH 8.5 ========================= This release contains mostly bug fixes. New features ------------ * sftp-server(8): add a new limits@openssh.com protocol extension that allows a client to discover various server limits, including maximum packet size and maximum read/write length. * sftp(1): use the new limits@openssh.com extension (when available) to select better transfer lengths in the client. * sshd(8): Add ModuliFile keyword to sshd_config to specify the location of the "moduli" file containing the groups for DH-GEX. * unit tests: Add a TEST_SSH_ELAPSED_TIMES environment variable to enable printing of the elapsed time in seconds of each test. Bugfixes -------- * ssh_config(5), sshd_config(5): sync CASignatureAlgorithms lists in manual pages with the current default. GHPR#174 * ssh(1): ensure that pkcs11_del_provider() is called before exit. GHPR#234 * ssh(1), sshd(8): fix problems in string->argv conversion. Multiple backslashes were not being dequoted correctly and quoted space in the middle of a string was being incorrectly split. GHPR#223 * ssh(1): return non-zero exit status when killed by signal; bz#3281 * sftp-server(8): increase maximum SSH2_FXP_READ to match the maximum packet size. Also handle zero-length reads that are not explicitly banned by the spec. Portability ----------- * sshd(8): don't mistakenly exit on transient read errors on the network socket (e.g. EINTR, EAGAIN); bz3297 * Create a dedicated contrib/gnome-ssk-askpass3.c source instead of building it from the same file as used for GNOME2. Use the GNOME3 gdk_seat_grab() to manage keyboard/mouse/server grabs for better compatibility with Wayland. * Fix portability build errors bz3293 bz3292 bz3291 bz3278 * sshd(8): soft-disallow the fstatat64 syscall in the Linux seccomp-bpf sandbox. bz3276 * unit tests: enable autoopt and misc unit tests that were previously skipped
2021-04-19 17:38:27 +03:00
const char *address; /* remote address */
From ftp.openbsd.org
2012-12-12 20:52:18 +04:00
const char *laddress; /* local address */
int lport; /* local port */
OpenSSH 7.7 was released on 2018-04-02. It is available from the mirrors listed at http://www.openssh.com/ shortly. OpenSSH is a 100% complete SSH protocol 2.0 implementation and includes sftp client and server support. Once again, we would like to thank the OpenSSH community for their continued support of the project, especially those who contributed code or patches, reported bugs, tested snapshots or donated to the project. More information on donations may be found at: http://www.openssh.com/donations.html Potentially-incompatible changes ================================ This release includes a number of changes that may affect existing configurations: * ssh(1)/sshd(8): Drop compatibility support for some very old SSH implementations, including ssh.com <=2.* and OpenSSH <= 3.*. These versions were all released in or before 2001 and predate the final SSH RFCs. The support in question isn't necessary for RFC-compliant SSH implementations. Changes since OpenSSH 7.6 ========================= This is primarily a bugfix release. New Features ------------ * All: Add experimental support for PQC XMSS keys (Extended Hash- Based Signatures) based on the algorithm described in https://tools.ietf.org/html/draft-irtf-cfrg-xmss-hash-based-signatures-12 The XMSS signature code is experimental and not compiled in by default. * sshd(8): Add a "rdomain" criteria for the sshd_config Match keyword to allow conditional configuration that depends on which routing domain a connection was received on (currently supported on OpenBSD and Linux). * sshd_config(5): Add an optional rdomain qualifier to the ListenAddress directive to allow listening on different routing domains. This is supported only on OpenBSD and Linux at present. * sshd_config(5): Add RDomain directive to allow the authenticated session to be placed in an explicit routing domain. This is only supported on OpenBSD at present. * sshd(8): Add "expiry-time" option for authorized_keys files to allow for expiring keys. * ssh(1): Add a BindInterface option to allow binding the outgoing connection to an interface's address (basically a more usable BindAddress) * ssh(1): Expose device allocated for tun/tap forwarding via a new %T expansion for LocalCommand. This allows LocalCommand to be used to prepare the interface. * sshd(8): Expose the device allocated for tun/tap forwarding via a new SSH_TUNNEL environment variable. This allows automatic setup of the interface and surrounding network configuration automatically on the server. * ssh(1)/scp(1)/sftp(1): Add URI support to ssh, sftp and scp, e.g. ssh://user@host or sftp://user@host/path. Additional connection parameters described in draft-ietf-secsh-scp-sftp-ssh-uri-04 are not implemented since the ssh fingerprint format in the draft uses the deprecated MD5 hash with no way to specify the any other algorithm. * ssh-keygen(1): Allow certificate validity intervals that specify only a start or stop time (instead of both or neither). * sftp(1): Allow "cd" and "lcd" commands with no explicit path argument. lcd will change to the local user's home directory as usual. cd will change to the starting directory for session (because the protocol offers no way to obtain the remote user's home directory). bz#2760 * sshd(8): When doing a config test with sshd -T, only require the attributes that are actually used in Match criteria rather than (an incomplete list of) all criteria. Bugfixes -------- * ssh(1)/sshd(8): More strictly check signature types during key exchange against what was negotiated. Prevents downgrade of RSA signatures made with SHA-256/512 to SHA-1. * sshd(8): Fix support for client that advertise a protocol version of "1.99" (indicating that they are prepared to accept both SSHv1 and SSHv2). This was broken in OpenSSH 7.6 during the removal of SSHv1 support. bz#2810 * ssh(1): Warn when the agent returns a ssh-rsa (SHA1) signature when a rsa-sha2-256/512 signature was requested. This condition is possible when an old or non-OpenSSH agent is in use. bz#2799 * ssh-agent(1): Fix regression introduced in 7.6 that caused ssh-agent to fatally exit if presented an invalid signature request message. * sshd_config(5): Accept yes/no flag options case-insensitively, as has been the case in ssh_config(5) for a long time. bz#2664 * ssh(1): Improve error reporting for failures during connection. Under some circumstances misleading errors were being shown. bz#2814 * ssh-keyscan(1): Add -D option to allow printing of results directly in SSHFP format. bz#2821 * regress tests: fix PuTTY interop test broken in last release's SSHv1 removal. bz#2823 * ssh(1): Compatibility fix for some servers that erroneously drop the connection when the IUTF8 (RFC8160) option is sent. * scp(1): Disable RemoteCommand and RequestTTY in the ssh session started by scp (sftp was already doing this.) * ssh-keygen(1): Refuse to create a certificate with an unusable number of principals. * ssh-keygen(1): Fatally exit if ssh-keygen is unable to write all the public key during key generation. Previously it would silently ignore errors writing the comment and terminating newline. * ssh(1): Do not modify hostname arguments that are addresses by automatically forcing them to lower-case. Instead canonicalise them to resolve ambiguities (e.g. ::0001 => ::1) before they are matched against known_hosts. bz#2763 * ssh(1): Don't accept junk after "yes" or "no" responses to hostkey prompts. bz#2803 * sftp(1): Have sftp print a warning about shell cleanliness when decoding the first packet fails, which is usually caused by shells polluting stdout of non-interactive startups. bz#2800 * ssh(1)/sshd(8): Switch timers in packet code from using wall-clock time to monotonic time, allowing the packet layer to better function over a clock step and avoiding possible integer overflows during steps. * Numerous manual page fixes and improvements. Portability ----------- * sshd(8): Correctly detect MIPS ABI in use at configure time. Fixes sandbox violations on some environments. * sshd(8): Remove UNICOS support. The hardware and software are literal museum pieces and support in sshd is too intrusive to justify maintaining. * All: Build and link with "retpoline" flags when available to mitigate the "branch target injection" style (variant 2) of the Spectre branch-prediction vulnerability. * All: Add auto-generated dependency information to Makefile. * Numerous fixed to the RPM spec files. Checksums: ========== - SHA1 (openssh-7.7.tar.gz) = 24812e05fa233014c847c7775748316e7f8a836c - SHA256 (openssh-7.7.tar.gz) = T4ua1L/vgAYqwB0muRahvnm5ZUr3PLY9nPljaG8egvo= - SHA1 (openssh-7.7p1.tar.gz) = 446fe9ed171f289f0d62197dffdbfdaaf21c49f2 - SHA256 (openssh-7.7p1.tar.gz) = 1zvn5oTpnvzQJL4Vowv/y+QbASsvezyQhK7WIXdea48= Please note that the SHA256 signatures are base64 encoded and not hexadecimal (which is the default for most checksum tools). The PGP key used to sign the releases is available as RELEASE_KEY.asc from the mirror sites. Reporting Bugs: =============== - Please read http://www.openssh.com/report.html Security bugs should be reported directly to openssh@openssh.com
2018-04-06 21:56:05 +03:00
const char *rdomain; /* routing domain if available */
OpenSSH 8.1 was released on 2019-10-09. It is available from the mirrors listed at https://www.openssh.com/. OpenSSH is a 100% complete SSH protocol 2.0 implementation and includes sftp client and server support. Once again, we would like to thank the OpenSSH community for their continued support of the project, especially those who contributed code or patches, reported bugs, tested snapshots or donated to the project. More information on donations may be found at: http://www.openssh.com/donations.html Security ======== * ssh(1), sshd(8), ssh-add(1), ssh-keygen(1): an exploitable integer overflow bug was found in the private key parsing code for the XMSS key type. This key type is still experimental and support for it is not compiled by default. No user-facing autoconf option exists in portable OpenSSH to enable it. This bug was found by Adam Zabrocki and reported via SecuriTeam's SSD program. * ssh(1), sshd(8), ssh-agent(1): add protection for private keys at rest in RAM against speculation and memory side-channel attacks like Spectre, Meltdown and Rambleed. This release encrypts private keys when they are not in use with a symmetric key that is derived from a relatively large "prekey" consisting of random data (currently 16KB). Potentially-incompatible changes ================================ This release includes a number of changes that may affect existing configurations: * ssh-keygen(1): when acting as a CA and signing certificates with an RSA key, default to using the rsa-sha2-512 signature algorithm. Certificates signed by RSA keys will therefore be incompatible with OpenSSH versions prior to 7.2 unless the default is overridden (using "ssh-keygen -t ssh-rsa -s ...").
2019-10-12 18:13:53 +03:00
int test; /* test mode, allow some attributes to be
* unspecified */
From ftp.openbsd.org
2012-12-12 20:52:18 +04:00
};
OpenSSH 8.2/8.2p1 (2020-02-14) OpenSSH 8.2 was released on 2020-02-14. It is available from the mirrors listed at https://www.openssh.com/. OpenSSH is a 100% complete SSH protocol 2.0 implementation and includes sftp client and server support. Once again, we would like to thank the OpenSSH community for their continued support of the project, especially those who contributed code or patches, reported bugs, tested snapshots or donated to the project. More information on donations may be found at: https://www.openssh.com/donations.html Future deprecation notice ========================= It is now possible[1] to perform chosen-prefix attacks against the SHA-1 hash algorithm for less than USD$50K. For this reason, we will be disabling the "ssh-rsa" public key signature algorithm that depends on SHA-1 by default in a near-future release. This algorithm is unfortunately still used widely despite the existence of better alternatives, being the only remaining public key signature algorithm specified by the original SSH RFCs. The better alternatives include: * The RFC8332 RSA SHA-2 signature algorithms rsa-sha2-256/512. These algorithms have the advantage of using the same key type as "ssh-rsa" but use the safe SHA-2 hash algorithms. These have been supported since OpenSSH 7.2 and are already used by default if the client and server support them. * The ssh-ed25519 signature algorithm. It has been supported in OpenSSH since release 6.5. * The RFC5656 ECDSA algorithms: ecdsa-sha2-nistp256/384/521. These have been supported by OpenSSH since release 5.7. To check whether a server is using the weak ssh-rsa public key algorithm for host authentication, try to connect to it after removing the ssh-rsa algorithm from ssh(1)'s allowed list: ssh -oHostKeyAlgorithms=-ssh-rsa user@host If the host key verification fails and no other supported host key types are available, the server software on that host should be upgraded. A future release of OpenSSH will enable UpdateHostKeys by default to allow the client to automatically migrate to better algorithms. Users may consider enabling this option manually. [1] "SHA-1 is a Shambles: First Chosen-Prefix Collision on SHA-1 and Application to the PGP Web of Trust" Leurent, G and Peyrin, T (2020) https://eprint.iacr.org/2020/014.pdf Security ======== * ssh(1), sshd(8), ssh-keygen(1): this release removes the "ssh-rsa" (RSA/SHA1) algorithm from those accepted for certificate signatures (i.e. the client and server CASignatureAlgorithms option) and will use the rsa-sha2-512 signature algorithm by default when the ssh-keygen(1) CA signs new certificates. Certificates are at special risk to the aforementioned SHA1 collision vulnerability as an attacker has effectively unlimited time in which to craft a collision that yields them a valid certificate, far more than the relatively brief LoginGraceTime window that they have to forge a host key signature. The OpenSSH certificate format includes a CA-specified (typically random) nonce value near the start of the certificate that should make exploitation of chosen-prefix collisions in this context challenging, as the attacker does not have full control over the prefix that actually gets signed. Nonetheless, SHA1 is now a demonstrably broken algorithm and futher improvements in attacks are highly likely. OpenSSH releases prior to 7.2 do not support the newer RSA/SHA2 algorithms and will refuse to accept certificates signed by an OpenSSH 8.2+ CA using RSA keys unless the unsafe algorithm is explicitly selected during signing ("ssh-keygen -t ssh-rsa"). Older clients/servers may use another CA key type such as ssh-ed25519 (supported since OpenSSH 6.5) or one of the ecdsa-sha2-nistp256/384/521 types (supported since OpenSSH 5.7) instead if they cannot be upgraded. Potentially-incompatible changes ================================ This release includes a number of changes that may affect existing configurations: * ssh(1), sshd(8): the above removal of "ssh-rsa" from the accepted CASignatureAlgorithms list. * ssh(1), sshd(8): this release removes diffie-hellman-group14-sha1 from the default key exchange proposal for both the client and server. * ssh-keygen(1): the command-line options related to the generation and screening of safe prime numbers used by the diffie-hellman-group-exchange-* key exchange algorithms have changed. Most options have been folded under the -O flag. * sshd(8): the sshd listener process title visible to ps(1) has changed to include information about the number of connections that are currently attempting authentication and the limits configured by MaxStartups. * ssh-sk-helper(8): this is a new binary. It is used by the FIDO/U2F support to provide address-space isolation for token middleware libraries (including the internal one). It needs to be installed in the expected path, typically under /usr/libexec or similar. Changes since OpenSSH 8.1 ========================= This release contains some significant new features. FIDO/U2F Support ---------------- This release adds support for FIDO/U2F hardware authenticators to OpenSSH. U2F/FIDO are open standards for inexpensive two-factor authentication hardware that are widely used for website authentication. In OpenSSH FIDO devices are supported by new public key types "ecdsa-sk" and "ed25519-sk", along with corresponding certificate types. ssh-keygen(1) may be used to generate a FIDO token-backed key, after which they may be used much like any other key type supported by OpenSSH, so long as the hardware token is attached when the keys are used. FIDO tokens also generally require the user explicitly authorise operations by touching or tapping them. Generating a FIDO key requires the token be attached, and will usually require the user tap the token to confirm the operation: $ ssh-keygen -t ecdsa-sk -f ~/.ssh/id_ecdsa_sk Generating public/private ecdsa-sk key pair. You may need to touch your security key to authorize key generation. Enter file in which to save the key (/home/djm/.ssh/id_ecdsa_sk): Enter passphrase (empty for no passphrase): Enter same passphrase again: Your identification has been saved in /home/djm/.ssh/id_ecdsa_sk Your public key has been saved in /home/djm/.ssh/id_ecdsa_sk.pub This will yield a public and private key-pair. The private key file should be useless to an attacker who does not have access to the physical token. After generation, this key may be used like any other supported key in OpenSSH and may be listed in authorized_keys, added to ssh-agent(1), etc. The only additional stipulation is that the FIDO token that the key belongs to must be attached when the key is used. FIDO tokens are most commonly connected via USB but may be attached via other means such as Bluetooth or NFC. In OpenSSH, communication with the token is managed via a middleware library, specified by the SecurityKeyProvider directive in ssh/sshd_config(5) or the $SSH_SK_PROVIDER environment variable for ssh-keygen(1) and ssh-add(1). The API for this middleware is documented in the sk-api.h and PROTOCOL.u2f files in the source distribution. OpenSSH includes a middleware ("SecurityKeyProvider=internal") with support for USB tokens. It is automatically enabled in OpenBSD and may be enabled in portable OpenSSH via the configure flag --with-security-key-builtin. If the internal middleware is enabled then it is automatically used by default. This internal middleware requires that libfido2 (https://github.com/Yubico/libfido2) and its dependencies be installed. We recommend that packagers of portable OpenSSH enable the built-in middleware, as it provides the lowest-friction experience for users. Note: FIDO/U2F tokens are required to implement the ECDSA-P256 "ecdsa-sk" key type, but hardware support for Ed25519 "ed25519-sk" is less common. Similarly, not all hardware tokens support some of the optional features such as resident keys. The protocol-level changes to support FIDO/U2F keys in SSH are documented in the PROTOCOL.u2f file in the OpenSSH source distribution. There are a number of supporting changes to this feature: * ssh-keygen(1): add a "no-touch-required" option when generating FIDO-hosted keys, that disables their default behaviour of requiring a physical touch/tap on the token during authentication. Note: not all tokens support disabling the touch requirement. * sshd(8): add a sshd_config PubkeyAuthOptions directive that collects miscellaneous public key authentication-related options for sshd(8). At present it supports only a single option "no-touch-required". This causes sshd to skip its default check for FIDO/U2F keys that the signature was authorised by a touch or press event on the token hardware. * ssh(1), sshd(8), ssh-keygen(1): add a "no-touch-required" option for authorized_keys and a similar extension for certificates. This option disables the default requirement that FIDO key signatures attest that the user touched their key to authorize them, mirroring the similar PubkeyAuthOptions sshd_config option. * ssh-keygen(1): add support for the writing the FIDO attestation information that is returned when new keys are generated via the "-O write-attestation=/path" option. FIDO attestation certificates may be used to verify that a FIDO key is hosted in trusted hardware. OpenSSH does not currently make use of this information, beyond optionally writing it to disk. FIDO2 resident keys ------------------- FIDO/U2F OpenSSH keys consist of two parts: a "key handle" part stored in the private key file on disk, and a per-device private key that is unique to each FIDO/U2F token and that cannot be exported from the token hardware. These are combined by the hardware at authentication time to derive the real key that is used to sign authentication challenges. For tokens that are required to move between computers, it can be cumbersome to have to move the private key file first. To avoid this requirement, tokens implementing the newer FIDO2 standard support "resident keys", where it is possible to effectively retrieve the key handle part of the key from the hardware. OpenSSH supports this feature, allowing resident keys to be generated using the ssh-keygen(1) "-O resident" flag. This will produce a public/private key pair as usual, but it will be possible to retrieve the private key part from the token later. This may be done using "ssh-keygen -K", which will download all available resident keys from the tokens attached to the host and write public/private key files for them. It is also possible to download and add resident keys directly to ssh-agent(1) without writing files to the file-system using "ssh-add -K". Resident keys are indexed on the token by the application string and user ID. By default, OpenSSH uses an application string of "ssh:" and an empty user ID. If multiple resident keys on a single token are desired then it may be necessary to override one or both of these defaults using the ssh-keygen(1) "-O application=" or "-O user=" options. Note: OpenSSH will only download and use resident keys whose application string begins with "ssh:" Storing both parts of a key on a FIDO token increases the likelihood of an attacker being able to use a stolen token device. For this reason, tokens should enforce PIN authentication before allowing download of keys, and users should set a PIN on their tokens before creating any resident keys. Other New Features ------------------ * sshd(8): add an Include sshd_config keyword that allows including additional configuration files via glob(3) patterns. bz2468 * ssh(1)/sshd(8): make the LE (low effort) DSCP code point available via the IPQoS directive; bz2986, * ssh(1): when AddKeysToAgent=yes is set and the key contains no comment, add the key to the agent with the key's path as the comment. bz2564 * ssh-keygen(1), ssh-agent(1): expose PKCS#11 key labels and X.509 subjects as key comments, rather than simply listing the PKCS#11 provider library path. PR138 * ssh-keygen(1): allow PEM export of DSA and ECDSA keys; bz3091 * ssh(1), sshd(8): make zlib compile-time optional, available via the Makefile.inc ZLIB flag on OpenBSD or via the --with-zlib configure option for OpenSSH portable. * sshd(8): when clients get denied by MaxStartups, send a notification prior to the SSH2 protocol banner according to RFC4253 section 4.2. * ssh(1), ssh-agent(1): when invoking the $SSH_ASKPASS prompt program, pass a hint to the program to describe the type of desired prompt. The possible values are "confirm" (indicating that a yes/no confirmation dialog with no text entry should be shown), "none" (to indicate an informational message only), or blank for the original ssh-askpass behaviour of requesting a password/phrase. * ssh(1): allow forwarding a different agent socket to the path specified by $SSH_AUTH_SOCK, by extending the existing ForwardAgent option to accepting an explicit path or the name of an environment variable in addition to yes/no. * ssh-keygen(1): add a new signature operations "find-principals" to look up the principal associated with a signature from an allowed- signers file. * sshd(8): expose the number of currently-authenticating connections along with the MaxStartups limit in the process title visible to "ps". Bugfixes -------- * sshd(8): make ClientAliveCountMax=0 have sensible semantics: it will now disable connection killing entirely rather than the current behaviour of instantly killing the connection after the first liveness test regardless of success. bz2627 * sshd(8): clarify order of AllowUsers / DenyUsers vs AllowGroups / DenyGroups in the sshd(8) manual page. bz1690 * sshd(8): better describe HashKnownHosts in the manual page. bz2560 * sshd(8): clarify that that permitopen=/PermitOpen do no name or address translation in the manual page. bz3099 * sshd(8): allow the UpdateHostKeys feature to function when multiple known_hosts files are in use. When updating host keys, ssh will now search subsequent known_hosts files, but will add updated host keys to the first specified file only. bz2738 * All: replace all calls to signal(2) with a wrapper around sigaction(2). This wrapper blocks all other signals during the handler preventing races between handlers, and sets SA_RESTART which should reduce the potential for short read/write operations. * sftp(1): fix a race condition in the SIGCHILD handler that could turn in to a kill(-1); bz3084 * sshd(8): fix a case where valid (but extremely large) SSH channel IDs were being incorrectly rejected. bz3098 * ssh(1): when checking host key fingerprints as answers to new hostkey prompts, ignore whitespace surrounding the fingerprint itself. * All: wait for file descriptors to be readable or writeable during non-blocking connect, not just readable. Prevents a timeout when the server doesn't immediately send a banner (e.g. multiplexers like sslh) * sshd_config(5): document the sntrup4591761x25519-sha512@tinyssh.org key exchange algorithm. PR#151
2020-02-27 03:21:35 +03:00
/* List of included files for re-exec from the parsed configuration */
struct include_item {
char *selector;
char *filename;
struct sshbuf *contents;
TAILQ_ENTRY(include_item) entry;
};
TAILQ_HEAD(include_list, include_item);
From ftp.openbsd.org
2012-12-12 20:52:18 +04:00
new openssh: See http://www.openssh.com/txt/release-5.9
2011-09-07 00:16:49 +04:00
/*
* These are string config options that must be copied between the
* Match sub-config and the main config, and must be sent from the
OpenSSH 8.4 was released on 2020-09-27. It is available from the mirrors listed at https://www.openssh.com/. OpenSSH is a 100% complete SSH protocol 2.0 implementation and includes sftp client and server support. Once again, we would like to thank the OpenSSH community for their continued support of the project, especially those who contributed code or patches, reported bugs, tested snapshots or donated to the project. More information on donations may be found at: https://www.openssh.com/donations.html Future deprecation notice ========================= It is now possible[1] to perform chosen-prefix attacks against the SHA-1 algorithm for less than USD$50K. For this reason, we will be disabling the "ssh-rsa" public key signature algorithm by default in a near-future release. This algorithm is unfortunately still used widely despite the existence of better alternatives, being the only remaining public key signature algorithm specified by the original SSH RFCs. The better alternatives include: * The RFC8332 RSA SHA-2 signature algorithms rsa-sha2-256/512. These algorithms have the advantage of using the same key type as "ssh-rsa" but use the safe SHA-2 hash algorithms. These have been supported since OpenSSH 7.2 and are already used by default if the client and server support them. * The ssh-ed25519 signature algorithm. It has been supported in OpenSSH since release 6.5. * The RFC5656 ECDSA algorithms: ecdsa-sha2-nistp256/384/521. These have been supported by OpenSSH since release 5.7. To check whether a server is using the weak ssh-rsa public key algorithm, for host authentication, try to connect to it after removing the ssh-rsa algorithm from ssh(1)'s allowed list: ssh -oHostKeyAlgorithms=-ssh-rsa user@host If the host key verification fails and no other supported host key types are available, the server software on that host should be upgraded. We intend to enable UpdateHostKeys by default in the next OpenSSH release. This will assist the client by automatically migrating to better algorithms. Users may consider enabling this option manually. [1] "SHA-1 is a Shambles: First Chosen-Prefix Collision on SHA-1 and Application to the PGP Web of Trust" Leurent, G and Peyrin, T (2020) https://eprint.iacr.org/2020/014.pdf Security ======== * ssh-agent(1): restrict ssh-agent from signing web challenges for FIDO/U2F keys. When signing messages in ssh-agent using a FIDO key that has an application string that does not start with "ssh:", ensure that the message being signed is one of the forms expected for the SSH protocol (currently public key authentication and sshsig signatures). This prevents ssh-agent forwarding on a host that has FIDO keys attached granting the ability for the remote side to sign challenges for web authentication using those keys too. Note that the converse case of web browsers signing SSH challenges is already precluded because no web RP can have the "ssh:" prefix in the application string that we require. * ssh-keygen(1): Enable FIDO 2.1 credProtect extension when generating a FIDO resident key. The recent FIDO 2.1 Client to Authenticator Protocol introduced a "credProtect" feature to better protect resident keys. We use this option to require a PIN prior to all operations that may retrieve a resident key from a FIDO token. Potentially-incompatible changes ================================ This release includes a number of changes that may affect existing configurations: * For FIDO/U2F support, OpenSSH recommends the use of libfido2 1.5.0 or greater. Older libraries have limited support at the expense of disabling particular features. These include resident keys, PIN- required keys and multiple attached tokens. * ssh-keygen(1): the format of the attestation information optionally recorded when a FIDO key is generated has changed. It now includes the authenticator data needed to validate attestation signatures. * The API between OpenSSH and the FIDO token middleware has changed and the SSH_SK_VERSION_MAJOR version has been incremented as a result. Third-party middleware libraries must support the current API version (7) to work with OpenSSH 8.4. * The portable OpenSSH distribution now requires automake to rebuild the configure script and supporting files. This is not required when simply building portable OpenSSH from a release tar file. Changes since OpenSSH 8.3 ========================= New features ------------ * ssh(1), ssh-keygen(1): support for FIDO keys that require a PIN for each use. These keys may be generated using ssh-keygen using a new "verify-required" option. When a PIN-required key is used, the user will be prompted for a PIN to complete the signature operation. * sshd(8): authorized_keys now supports a new "verify-required" option to require FIDO signatures assert that the token verified that the user was present before making the signature. The FIDO protocol supports multiple methods for user-verification, but currently OpenSSH only supports PIN verification. * sshd(8), ssh-keygen(1): add support for verifying FIDO webauthn signatures. Webauthn is a standard for using FIDO keys in web browsers. These signatures are a slightly different format to plain FIDO signatures and thus require explicit support. * ssh(1): allow some keywords to expand shell-style ${ENV} environment variables. The supported keywords are CertificateFile, ControlPath, IdentityAgent and IdentityFile, plus LocalForward and RemoteForward when used for Unix domain socket paths. bz#3140 * ssh(1), ssh-agent(1): allow some additional control over the use of ssh-askpass via a new $SSH_ASKPASS_REQUIRE environment variable, including forcibly enabling and disabling its use. bz#69 * ssh(1): allow ssh_config(5)'s AddKeysToAgent keyword accept a time limit for keys in addition to its current flag options. Time- limited keys will automatically be removed from ssh-agent after their expiry time has passed. * scp(1), sftp(1): allow the -A flag to explicitly enable agent forwarding in scp and sftp. The default remains to not forward an agent, even when ssh_config enables it. * ssh(1): add a '%k' TOKEN that expands to the effective HostKey of the destination. This allows, e.g., keeping host keys in individual files using "UserKnownHostsFile ~/.ssh/known_hosts.d/%k". bz#1654 * ssh(1): add %-TOKEN, environment variable and tilde expansion to the UserKnownHostsFile directive, allowing the path to be completed by the configuration (e.g. bz#1654) * ssh-keygen(1): allow "ssh-add -d -" to read keys to be deleted from stdin. bz#3180 * sshd(8): improve logging for MaxStartups connection throttling. sshd will now log when it starts and stops throttling and periodically while in this state. bz#3055 Bugfixes -------- * ssh(1), ssh-keygen(1): better support for multiple attached FIDO tokens. In cases where OpenSSH cannot unambiguously determine which token to direct a request to, the user is now required to select a token by touching it. In cases of operations that require a PIN to be verified, this avoids sending the wrong PIN to the wrong token and incrementing the token's PIN failure counter (tokens effectively erase their keys after too many PIN failures). * sshd(8): fix Include before Match in sshd_config; bz#3122 * ssh(1): close stdin/out/error when forking after authentication completes ("ssh -f ...") bz#3137 * ssh(1), sshd(8): limit the amount of channel input data buffered, avoiding peers that advertise large windows but are slow to read from causing high memory consumption. * ssh-agent(1): handle multiple requests sent in a single write() to the agent. * sshd(8): allow sshd_config longer than 256k * sshd(8): avoid spurious "Unable to load host key" message when sshd load a private key but no public counterpart * ssh(1): prefer the default hostkey algorithm list whenever we have a hostkey that matches its best-preference algorithm. * sshd(1): when ordering the hostkey algorithms to request from a server, prefer certificate types if the known_hosts files contain a key marked as a @cert-authority; bz#3157 * ssh(1): perform host key fingerprint comparisons for the "Are you sure you want to continue connecting (yes/no/[fingerprint])?" prompt with case sensitivity. * sshd(8): ensure that address/masklen mismatches in sshd_config yield fatal errors at daemon start time rather than later when they are evaluated. * ssh-keygen(1): ensure that certificate extensions are lexically sorted. Previously if the user specified a custom extension then the everything would be in order except the custom ones. bz#3198 * ssh(1): also compare username when checking for JumpHost loops. bz#3057 * ssh-keygen(1): preserve group/world read permission on known_hosts files across runs of "ssh-keygen -Rf /path". The old behaviour was to remove all rights for group/other. bz#3146 * ssh-keygen(1): Mention the [-a rounds] flag in the ssh-keygen manual page and usage(). * sshd(8): explicitly construct path to ~/.ssh/rc rather than relying on it being relative to the current directory, so that it can still be found if the shell startup changes its directory. bz#3185 * sshd(8): when redirecting sshd's log output to a file, undo this redirection after the session child process is forked(). Fixes missing log messages when using this feature under some circumstances. * sshd(8): start ClientAliveInterval bookkeeping before first pass through select() loop; fixed theoretical case where busy sshd may ignore timeouts from client. * ssh(1): only reset the ServerAliveInterval check when we receive traffic from the server and ignore traffic from a port forwarding client, preventing a client from keeping a connection alive when it should be terminated. bz#2265 * ssh-keygen(1): avoid spurious error message when ssh-keygen creates files outside ~/.ssh * sftp-client(1): fix off-by-one error that caused sftp downloads to make one more concurrent request that desired. This prevented using sftp(1) in unpipelined request/response mode, which is useful when debugging. bz#3054 * ssh(1), sshd(8): handle EINTR in waitfd() and timeout_connect() helpers. bz#3071 * ssh(1), ssh-keygen(1): defer creation of ~/.ssh until we attempt to write to it so we don't leave an empty .ssh directory when it's not needed. bz#3156 * ssh(1), sshd(8): fix multiplier when parsing time specifications when handling seconds after other units. bz#3171 Portability ----------- * sshd(8): always send any PAM account messages. If the PAM account stack returns any messages, always send them to the user and not just if the check succeeds. bz#2049 * Implement some backwards compatibility for libfido2 libraries older than 1.5.0. Note that use of an older library will result in the loss of certain features including resident key support, PIN support and support for multiple attached tokens. * configure fixes for XCode 12 * gnome-ssh-askpass3: ensure the "close" button is not focused by default for SSH_ASKPASS_PROMPT=none prompts. Avoids space/enter accidentally dismissing FIDO touch notifications. * gnome-ssh-askpass3: allow some control over textarea colour via $GNOME_SSH_ASKPASS_FG_COLOR and $GNOME_SSH_ASKPASS_BG_COLOR environment variables. * sshd(8): document another PAM spec problem in a frustrated comment * sshd(8): support NetBSD's utmpx.ut_ss address field. bz#960 * Add the ssh-sk-helper binary and its manpage to the RPM spec file * Detect the Frankenstein monster of Linux/X32 and allow the sandbox to function there. bz#3085
2020-12-04 21:40:04 +03:00
* privsep child to the privsep master. We use a macro to ensure all
new openssh: See http://www.openssh.com/txt/release-5.9
2011-09-07 00:16:49 +04:00
* the options are copied and the copies are done in the correct order.
Changes since OpenSSH 6.6 ========================= Potentially-incompatible changes * sshd(8): The default set of ciphers and MACs has been altered to remove unsafe algorithms. In particular, CBC ciphers and arcfour* are disabled by default. The full set of algorithms remains available if configured explicitly via the Ciphers and MACs sshd_config options. * sshd(8): Support for tcpwrappers/libwrap has been removed. * OpenSSH 6.5 and 6.6 have a bug that causes ~0.2% of connections using the curve25519-sha256@libssh.org KEX exchange method to fail when connecting with something that implements the specification correctly. OpenSSH 6.7 disables this KEX method when speaking to one of the affected versions. New Features * Major internal refactoring to begin to make part of OpenSSH usable as a library. So far the wire parsing, key handling and KRL code has been refactored. Please note that we do not consider the API stable yet, nor do we offer the library in separable form. * ssh(1), sshd(8): Add support for Unix domain socket forwarding. A remote TCP port may be forwarded to a local Unix domain socket and vice versa or both ends may be a Unix domain socket. * ssh(1), ssh-keygen(1): Add support for SSHFP DNS records for ED25519 key types. * sftp(1): Allow resumption of interrupted uploads. * ssh(1): When rekeying, skip file/DNS lookups of the hostkey if it is the same as the one sent during initial key exchange; bz#2154 * sshd(8): Allow explicit ::1 and 127.0.0.1 forwarding bind addresses when GatewayPorts=no; allows client to choose address family; bz#2222 * sshd(8): Add a sshd_config PermitUserRC option to control whether ~/.ssh/rc is executed, mirroring the no-user-rc authorized_keys option; bz#2160 * ssh(1): Add a %C escape sequence for LocalCommand and ControlPath that expands to a unique identifer based on a hash of the tuple of (local host, remote user, hostname, port). Helps avoid exceeding miserly pathname limits for Unix domain sockets in multiplexing control paths; bz#2220 * sshd(8): Make the "Too many authentication failures" message include the user, source address, port and protocol in a format similar to the authentication success / failure messages; bz#2199 * Added unit and fuzz tests for refactored code. These are run automatically in portable OpenSSH via the "make tests" target. Bugfixes * sshd(8): Fix remote forwarding with the same listen port but different listen address. * ssh(1): Fix inverted test that caused PKCS#11 keys that were explicitly listed in ssh_config or on the commandline not to be preferred. * ssh-keygen(1): Fix bug in KRL generation: multiple consecutive revoked certificate serial number ranges could be serialised to an invalid format. Readers of a broken KRL caused by this bug will fail closed, so no should-have-been-revoked key will be accepted. * ssh(1): Reflect stdio-forward ("ssh -W host:port ...") failures in exit status. Previously we were always returning 0; bz#2255 * ssh(1), ssh-keygen(1): Make Ed25519 keys' title fit properly in the randomart border; bz#2247 * ssh-agent(1): Only cleanup agent socket in the main agent process and not in any subprocesses it may have started (e.g. forked askpass). Fixes agent sockets being zapped when askpass processes fatal(); bz#2236 * ssh-add(1): Make stdout line-buffered; saves partial output getting lost when ssh-add fatal()s part-way through (e.g. when listing keys from an agent that supports key types that ssh-add doesn't); bz#2234 * ssh-keygen(1): When hashing or removing hosts, don't choke on @revoked markers and don't remove @cert-authority markers; bz#2241 * ssh(1): Don't fatal when hostname canonicalisation fails and a ProxyCommand is in use; continue and allow the ProxyCommand to connect anyway (e.g. to a host with a name outside the DNS behind a bastion) * scp(1): When copying local->remote fails during read, don't send uninitialised heap to the remote end. * sftp(1): Fix fatal "el_insertstr failed" errors when tab-completing filenames with a single quote char somewhere in the string; bz#2238 * ssh-keyscan(1): Scan for Ed25519 keys by default. * ssh(1): When using VerifyHostKeyDNS with a DNSSEC resolver, down- convert any certificate keys to plain keys and attempt SSHFP resolution. Prevents a server from skipping SSHFP lookup and forcing a new-hostkey dialog by offering only certificate keys. * sshd(8): Avoid crash at exit via NULL pointer reference; bz#2225 * Fix some strict-alignment errors. Portable OpenSSH * Portable OpenSSH now supports building against libressl-portable. * Portable OpenSSH now requires openssl 0.9.8f or greater. Older versions are no longer supported. * In the OpenSSL version check, allow fix version upgrades (but not downgrades. Debian bug #748150. * sshd(8): On Cygwin, determine privilege separation user at runtime, since it may need to be a domain account. * sshd(8): Don't attempt to use vhangup on Linux. It doesn't work for non-root users, and for them it just messes up the tty settings. * Use CLOCK_BOOTTIME in preference to CLOCK_MONOTONIC when it is available. It considers time spent suspended, thereby ensuring timeouts (e.g. for expiring agent keys) fire correctly. bz#2228 * Add support for ed25519 to opensshd.init init script. * sftp-server(8): On platforms that support it, use prctl() to prevent sftp-server from accessing /proc/self/{mem,maps} Changes since OpenSSH 6.5 ========================= This is primarily a bugfix release. Security: * sshd(8): when using environment passing with a sshd_config(5) AcceptEnv pattern with a wildcard. OpenSSH prior to 6.6 could be tricked into accepting any enviornment variable that contains the characters before the wildcard character. New / changed features: * ssh(1), sshd(8): this release removes the J-PAKE authentication code. This code was experimental, never enabled and had been unmaintained for some time. * ssh(1): when processing Match blocks, skip 'exec' clauses other clauses predicates failed to match. * ssh(1): if hostname canonicalisation is enabled and results in the destination hostname being changed, then re-parse ssh_config(5) files using the new destination hostname. This gives 'Host' and 'Match' directives that use the expanded hostname a chance to be applied. Bugfixes: * ssh(1): avoid spurious "getsockname failed: Bad file descriptor" in ssh -W. bz#2200, debian#738692 * sshd(8): allow the shutdown(2) syscall in seccomp-bpf and systrace sandbox modes, as it is reachable if the connection is terminated during the pre-auth phase. * ssh(1), sshd(8): fix unsigned overflow that in SSH protocol 1 bignum parsing. Minimum key length checks render this bug unexploitable to compromise SSH 1 sessions. * sshd_config(5): clarify behaviour of a keyword that appears in multiple matching Match blocks. bz#2184 * ssh(1): avoid unnecessary hostname lookups when canonicalisation is disabled. bz#2205 * sshd(8): avoid sandbox violation crashes in GSSAPI code by caching the supported list of GSSAPI mechanism OIDs before entering the sandbox. bz#2107 * ssh(1): fix possible crashes in SOCKS4 parsing caused by assumption that the SOCKS username is nul-terminated. * ssh(1): fix regression for UsePrivilegedPort=yes when BindAddress is not specified. * ssh(1), sshd(8): fix memory leak in ECDSA signature verification. * ssh(1): fix matching of 'Host' directives in ssh_config(5) files to be case-insensitive again (regression in 6.5). Portable OpenSSH: * sshd(8): don't fatal if the FreeBSD Capsicum is offered by the system headers and libc but is not supported by the kernel. * Fix build using the HP-UX compiler. Changes since OpenSSH 6.4 ========================= This is a feature-focused release. New features: * ssh(1), sshd(8): Add support for key exchange using elliptic-curve Diffie Hellman in Daniel Bernstein's Curve25519. This key exchange method is the default when both the client and server support it. * ssh(1), sshd(8): Add support for Ed25519 as a public key type. Ed25519 is a elliptic curve signature scheme that offers better security than ECDSA and DSA and good performance. It may be used for both user and host keys. * Add a new private key format that uses a bcrypt KDF to better protect keys at rest. This format is used unconditionally for Ed25519 keys, but may be requested when generating or saving existing keys of other types via the -o ssh-keygen(1) option. We intend to make the new format the default in the near future. Details of the new format are in the PROTOCOL.key file. * ssh(1), sshd(8): Add a new transport cipher "chacha20-poly1305@openssh.com" that combines Daniel Bernstein's ChaCha20 stream cipher and Poly1305 MAC to build an authenticated encryption mode. Details are in the PROTOCOL.chacha20poly1305 file. * ssh(1), sshd(8): Refuse RSA keys from old proprietary clients and servers that use the obsolete RSA+MD5 signature scheme. It will still be possible to connect with these clients/servers but only DSA keys will be accepted, and OpenSSH will refuse connection entirely in a future release. * ssh(1), sshd(8): Refuse old proprietary clients and servers that use a weaker key exchange hash calculation. * ssh(1): Increase the size of the Diffie-Hellman groups requested for each symmetric key size. New values from NIST Special Publication 800-57 with the upper limit specified by RFC4419. * ssh(1), ssh-agent(1): Support PKCS#11 tokens that only provide X.509 certs instead of raw public keys (requested as bz#1908). * ssh(1): Add a ssh_config(5) "Match" keyword that allows conditional configuration to be applied by matching on hostname, user and result of arbitrary commands. * ssh(1): Add support for client-side hostname canonicalisation using a set of DNS suffixes and rules in ssh_config(5). This allows unqualified names to be canonicalised to fully-qualified domain names to eliminate ambiguity when looking up keys in known_hosts or checking host certificate names. * sftp-server(8): Add the ability to whitelist and/or blacklist sftp protocol requests by name. * sftp-server(8): Add a sftp "fsync@openssh.com" to support calling fsync(2) on an open file handle. * sshd(8): Add a ssh_config(5) PermitTTY to disallow TTY allocation, mirroring the longstanding no-pty authorized_keys option. * ssh(1): Add a ssh_config ProxyUseFDPass option that supports the use of ProxyCommands that establish a connection and then pass a connected file descriptor back to ssh(1). This allows the ProxyCommand to exit rather than staying around to transfer data. Bugfixes: * ssh(1), sshd(8): Fix potential stack exhaustion caused by nested certificates. * ssh(1): bz#1211: make BindAddress work with UsePrivilegedPort. * sftp(1): bz#2137: fix the progress meter for resumed transfer. * ssh-add(1): bz#2187: do not request smartcard PIN when removing keys from ssh-agent. * sshd(8): bz#2139: fix re-exec fallback when original sshd binary cannot be executed. * ssh-keygen(1): Make relative-specified certificate expiry times relative to current time and not the validity start time. * sshd(8): bz#2161: fix AuthorizedKeysCommand inside a Match block. * sftp(1): bz#2129: symlinking a file would incorrectly canonicalise the target path. * ssh-agent(1): bz#2175: fix a use-after-free in the PKCS#11 agent helper executable. * sshd(8): Improve logging of sessions to include the user name, remote host and port, the session type (shell, command, etc.) and allocated TTY (if any). * sshd(8): bz#1297: tell the client (via a debug message) when their preferred listen address has been overridden by the server's GatewayPorts setting. * sshd(8): bz#2162: include report port in bad protocol banner message. * sftp(1): bz#2163: fix memory leak in error path in do_readdir(). * sftp(1): bz#2171: don't leak file descriptor on error. * sshd(8): Include the local address and port in "Connection from ..." message (only shown at loglevel>=verbose). Portable OpenSSH: * Please note that this is the last version of Portable OpenSSH that will support versions of OpenSSL prior to 0.9.6. Support (i.e. SSH_OLD_EVP) will be removed following the 6.5p1 release. * Portable OpenSSH will attempt compile and link as a Position Independent Executable on Linux, OS X and OpenBSD on recent gcc- like compilers. Other platforms and older/other compilers may request this using the --with-pie configure flag. * A number of other toolchain-related hardening options are used automatically if available, including -ftrapv to abort on signed integer overflow and options to write-protect dynamic linking information. The use of these options may be disabled using the --without-hardening configure flag. * If the toolchain supports it, one of the -fstack-protector-strong, -fstack-protector-all or -fstack-protector compilation flag are used to add guards to mitigate attacks based on stack overflows. The use of these options may be disabled using the --without-stackprotect configure option. * sshd(8): Add support for pre-authentication sandboxing using the Capsicum API introduced in FreeBSD 10. * Switch to a ChaCha20-based arc4random() PRNG for platforms that do not provide their own. * sshd(8): bz#2156: restore Linux oom_adj setting when handling SIGHUP to maintain behaviour over retart. * sshd(8): bz#2032: use local username in krb5_kuserok check rather than full client name which may be of form user@REALM. * ssh(1), sshd(8): Test for both the presence of ECC NID numbers in OpenSSL and that they actually work. Fedora (at least) has NID_secp521r1 that doesn't work. * bz#2173: use pkg-config --libs to include correct -L location for libedit.
2014-10-19 20:28:33 +04:00
*
* NB. an option must appear in servconf.c:copy_set_server_options() or
* COPY_MATCH_STRING_OPTS here but never both.
new openssh: See http://www.openssh.com/txt/release-5.9
2011-09-07 00:16:49 +04:00
*/
#define COPY_MATCH_STRING_OPTS() do { \
M_CP_STROPT(banner); \
M_CP_STROPT(trusted_user_ca_keys); \
M_CP_STROPT(revoked_keys_file); \
from openbsd
2013-03-29 18:52:38 +04:00
M_CP_STROPT(authorized_keys_command); \
M_CP_STROPT(authorized_keys_command_user); \
Changes since OpenSSH 6.8 ========================= This is primarily a bugfix release. Security -------- * ssh(1): when forwarding X11 connections with ForwardX11Trusted=no, connections made after ForwardX11Timeout expired could be permitted and no longer subject to XSECURITY restrictions because of an ineffective timeout check in ssh(1) coupled with "fail open" behaviour in the X11 server when clients attempted connections with expired credentials. This problem was reported by Jann Horn. * ssh-agent(1): fix weakness of agent locking (ssh-add -x) to password guessing by implementing an increasing failure delay, storing a salted hash of the password rather than the password itself and using a timing-safe comparison function for verifying unlock attempts. This problem was reported by Ryan Castellucci. New Features ------------ * ssh(1), sshd(8): promote chacha20-poly1305@openssh.com to be the default cipher * sshd(8): support admin-specified arguments to AuthorizedKeysCommand; bz#2081 * sshd(8): add AuthorizedPrincipalsCommand that allows retrieving authorized principals information from a subprocess rather than a file. * ssh(1), ssh-add(1): support PKCS#11 devices with external PIN entry devices bz#2240 * sshd(8): allow GSSAPI host credential check to be relaxed for multihomed hosts via GSSAPIStrictAcceptorCheck option; bz#928 * ssh-keygen(1): support "ssh-keygen -lF hostname" to search known_hosts and print key hashes rather than full keys. * ssh-agent(1): add -D flag to leave ssh-agent in foreground without enabling debug mode; bz#2381 Bugfixes -------- * ssh(1), sshd(8): deprecate legacy SSH2_MSG_KEX_DH_GEX_REQUEST_OLD message and do not try to use it against some 3rd-party SSH implementations that use it (older PuTTY, WinSCP). * Many fixes for problems caused by compile-time deactivation of SSH1 support (including bz#2369) * ssh(1), sshd(8): cap DH-GEX group size at 4Kbits for Cisco implementations as some would fail when attempting to use group sizes >4K; bz#2209 * ssh(1): fix out-of-bound read in EscapeChar configuration option parsing; bz#2396 * sshd(8): fix application of PermitTunnel, LoginGraceTime, AuthenticationMethods and StreamLocalBindMask options in Match blocks * ssh(1), sshd(8): improve disconnection message on TCP reset; bz#2257 * ssh(1): remove failed remote forwards established by muliplexing from the list of active forwards; bz#2363 * sshd(8): make parsing of authorized_keys "environment=" options independent of PermitUserEnv being enabled; bz#2329 * sshd(8): fix post-auth crash with permitopen=none; bz#2355 * ssh(1), ssh-add(1), ssh-keygen(1): allow new-format private keys to be encrypted with AEAD ciphers; bz#2366 * ssh(1): allow ListenAddress, Port and AddressFamily configuration options to appear in any order; bz#86 * sshd(8): check for and reject missing arguments for VersionAddendum and ForceCommand; bz#2281 * ssh(1), sshd(8): don't treat unknown certificate extensions as fatal; bz#2387 * ssh-keygen(1): make stdout and stderr output consistent; bz#2325 * ssh(1): mention missing DISPLAY environment in debug log when X11 forwarding requested; bz#1682 * sshd(8): correctly record login when UseLogin is set; bz#378 * sshd(8): Add some missing options to sshd -T output and fix output of VersionAddendum and HostCertificate. bz#2346 * Document and improve consistency of options that accept a "none" argument" TrustedUserCAKeys, RevokedKeys (bz#2382), AuthorizedPrincipalsFile (bz#2288) * ssh(1): include remote username in debug output; bz#2368 * sshd(8): avoid compatibility problem with some versions of Tera Term, which would crash when they received the hostkeys notification message (hostkeys-00@openssh.com) * sshd(8): mention ssh-keygen -E as useful when comparing legacy MD5 host key fingerprints; bz#2332 * ssh(1): clarify pseudo-terminal request behaviour and use make manual language consistent; bz#1716 * ssh(1): document that the TERM environment variable is not subject to SendEnv and AcceptEnv; bz#2386
2015-07-03 03:54:41 +03:00
M_CP_STROPT(authorized_principals_file); \
M_CP_STROPT(authorized_principals_command); \
M_CP_STROPT(authorized_principals_command_user); \
OpenSSH 8.5/8.5p1 (2021-03-03) OpenSSH 8.5 was released on 2021-03-03. It is available from the mirrors listed at https://www.openssh.com/. OpenSSH is a 100% complete SSH protocol 2.0 implementation and includes sftp client and server support. Once again, we would like to thank the OpenSSH community for their continued support of the project, especially those who contributed code or patches, reported bugs, tested snapshots or donated to the project. More information on donations may be found at: https://www.openssh.com/donations.html Future deprecation notice ========================= It is now possible[1] to perform chosen-prefix attacks against the SHA-1 algorithm for less than USD$50K. In the SSH protocol, the "ssh-rsa" signature scheme uses the SHA-1 hash algorithm in conjunction with the RSA public key algorithm. OpenSSH will disable this signature scheme by default in the near future. Note that the deactivation of "ssh-rsa" signatures does not necessarily require cessation of use for RSA keys. In the SSH protocol, keys may be capable of signing using multiple algorithms. In particular, "ssh-rsa" keys are capable of signing using "rsa-sha2-256" (RSA/SHA256), "rsa-sha2-512" (RSA/SHA512) and "ssh-rsa" (RSA/SHA1). Only the last of these is being turned off by default. This algorithm is unfortunately still used widely despite the existence of better alternatives, being the only remaining public key signature algorithm specified by the original SSH RFCs that is still enabled by default. The better alternatives include: * The RFC8332 RSA SHA-2 signature algorithms rsa-sha2-256/512. These algorithms have the advantage of using the same key type as "ssh-rsa" but use the safe SHA-2 hash algorithms. These have been supported since OpenSSH 7.2 and are already used by default if the client and server support them. * The RFC8709 ssh-ed25519 signature algorithm. It has been supported in OpenSSH since release 6.5. * The RFC5656 ECDSA algorithms: ecdsa-sha2-nistp256/384/521. These have been supported by OpenSSH since release 5.7. To check whether a server is using the weak ssh-rsa public key algorithm, for host authentication, try to connect to it after removing the ssh-rsa algorithm from ssh(1)'s allowed list: ssh -oHostKeyAlgorithms=-ssh-rsa user@host If the host key verification fails and no other supported host key types are available, the server software on that host should be upgraded. This release enables the UpdateHostKeys option by default to assist the client by automatically migrating to better algorithms. [1] "SHA-1 is a Shambles: First Chosen-Prefix Collision on SHA-1 and Application to the PGP Web of Trust" Leurent, G and Peyrin, T (2020) https://eprint.iacr.org/2020/014.pdf Security ======== * ssh-agent(1): fixed a double-free memory corruption that was introduced in OpenSSH 8.2 . We treat all such memory faults as potentially exploitable. This bug could be reached by an attacker with access to the agent socket. On modern operating systems where the OS can provide information about the user identity connected to a socket, OpenSSH ssh-agent and sshd limit agent socket access only to the originating user and root. Additional mitigation may be afforded by the system's malloc(3)/free(3) implementation, if it detects double-free conditions. The most likely scenario for exploitation is a user forwarding an agent either to an account shared with a malicious user or to a host with an attacker holding root access. * Portable sshd(8): Prevent excessively long username going to PAM. This is a mitigation for a buffer overflow in Solaris' PAM username handling (CVE-2020-14871), and is only enabled for Sun-derived PAM implementations. This is not a problem in sshd itself, it only prevents sshd from being used as a vector to attack Solaris' PAM. It does not prevent the bug in PAM from being exploited via some other PAM application. GHPR212 Potentially-incompatible changes ================================ This release includes a number of changes that may affect existing configurations: * ssh(1), sshd(8): this release changes the first-preference signature algorithm from ECDSA to ED25519. * ssh(1), sshd(8): set the TOS/DSCP specified in the configuration for interactive use prior to TCP connect. The connection phase of the SSH session is time-sensitive and often explicitly interactive. The ultimate interactive/bulk TOS/DSCP will be set after authentication completes. * ssh(1), sshd(8): remove the pre-standardization cipher rijndael-cbc@lysator.liu.se. It is an alias for aes256-cbc before it was standardized in RFC4253 (2006), has been deprecated and disabled by default since OpenSSH 7.2 (2016) and was only briefly documented in ssh.1 in 2001. * ssh(1), sshd(8): update/replace the experimental post-quantum hybrid key exchange method based on Streamlined NTRU Prime coupled with X25519. The previous sntrup4591761x25519-sha512@tinyssh.org method is replaced with sntrup761x25519-sha512@openssh.com. Per its designers, the sntrup4591761 algorithm was superseded almost two years ago by sntrup761. (note this both the updated method and the one that it replaced are disabled by default) * ssh(1): disable CheckHostIP by default. It provides insignificant benefits while making key rotation significantly more difficult, especially for hosts behind IP-based load-balancers. Changes since OpenSSH 8.4 ========================= New features ------------ * ssh(1): this release enables UpdateHostkeys by default subject to some conservative preconditions: - The key was matched in the UserKnownHostsFile (and not in the GlobalKnownHostsFile). - The same key does not exist under another name. - A certificate host key is not in use. - known_hosts contains no matching wildcard hostname pattern. - VerifyHostKeyDNS is not enabled. - The default UserKnownHostsFile is in use. We expect some of these conditions will be modified or relaxed in future. * ssh(1), sshd(8): add a new LogVerbose configuration directive for that allows forcing maximum debug logging by file/function/line pattern-lists. * ssh(1): when prompting the user to accept a new hostkey, display any other host names/addresses already associated with the key. * ssh(1): allow UserKnownHostsFile=none to indicate that no known_hosts file should be used to identify host keys. * ssh(1): add a ssh_config KnownHostsCommand option that allows the client to obtain known_hosts data from a command in addition to the usual files. * ssh(1): add a ssh_config PermitRemoteOpen option that allows the client to restrict the destination when RemoteForward is used with SOCKS. * ssh(1): for FIDO keys, if a signature operation fails with a "incorrect PIN" reason and no PIN was initially requested from the user, then request a PIN and retry the operation. This supports some biometric devices that fall back to requiring PIN when reading of the biometric failed, and devices that require PINs for all hosted credentials. * sshd(8): implement client address-based rate-limiting via new sshd_config(5) PerSourceMaxStartups and PerSourceNetBlockSize directives that provide more fine-grained control on a per-origin address basis than the global MaxStartups limit. Bugfixes -------- * ssh(1): Prefix keyboard interactive prompts with "(user@host)" to make it easier to determine which connection they are associated with in cases like scp -3, ProxyJump, etc. bz#3224 * sshd(8): fix sshd_config SetEnv directives located inside Match blocks. GHPR201 * ssh(1): when requesting a FIDO token touch on stderr, inform the user once the touch has been recorded. * ssh(1): prevent integer overflow when ridiculously large ConnectTimeout values are specified, capping the effective value (for most platforms) at 24 days. bz#3229 * ssh(1): consider the ECDSA key subtype when ordering host key algorithms in the client. * ssh(1), sshd(8): rename the PubkeyAcceptedKeyTypes keyword to PubkeyAcceptedAlgorithms. The previous name incorrectly suggested that it control allowed key algorithms, when this option actually specifies the signature algorithms that are accepted. The previous name remains available as an alias. bz#3253 * ssh(1), sshd(8): similarly, rename HostbasedKeyTypes (ssh) and HostbasedAcceptedKeyTypes (sshd) to HostbasedAcceptedAlgorithms. * sftp-server(8): add missing lsetstat@openssh.com documentation and advertisement in the server's SSH2_FXP_VERSION hello packet. * ssh(1), sshd(8): more strictly enforce KEX state-machine by banning packet types once they are received. Fixes memleak caused by duplicate SSH2_MSG_KEX_DH_GEX_REQUEST (oss-fuzz #30078). * sftp(1): allow the full range of UIDs/GIDs for chown/chgrp on 32bit platforms instead of being limited by LONG_MAX. bz#3206 * Minor man page fixes (capitalization, commas, etc.) bz#3223 * sftp(1): when doing an sftp recursive upload or download of a read-only directory, ensure that the directory is created with write and execute permissions in the interim so that the transfer can actually complete, then set the directory permission as the final step. bz#3222 * ssh-keygen(1): document the -Z, check the validity of its argument earlier and provide a better error message if it's not correct. bz#2879 * ssh(1): ignore comments at the end of config lines in ssh_config, similar to what we already do for sshd_config. bz#2320 * sshd_config(5): mention that DisableForwarding is valid in a sshd_config Match block. bz3239 * sftp(1): fix incorrect sorting of "ls -ltr" under some circumstances. bz3248. * ssh(1), sshd(8): fix potential integer truncation of (unlikely) timeout values. bz#3250 * ssh(1): make hostbased authentication send the signature algorithm in its SSH2_MSG_USERAUTH_REQUEST packets instead of the key type. This make HostbasedAcceptedAlgorithms do what it is supposed to - filter on signature algorithm and not key type. Portability ----------- * sshd(8): add a number of platform-specific syscalls to the Linux seccomp-bpf sandbox. bz#3232 bz#3260 * sshd(8): remove debug message from sigchld handler that could cause deadlock on some platforms. bz#3259 * Sync contrib/ssh-copy-id with upstream. * unittests: add a hostname function for systems that don't have it. Some systems don't have a hostname command (it's not required by POSIX). The do have uname -n (which is), but not all of those have it report the FQDN. Checksums: ========== - SHA1 (openssh-8.5.tar.gz) = 04cae43c389fb411227c01219e4eb46e3113f34e - SHA256 (openssh-8.5.tar.gz) = 5qB2CgzNG4io4DmChTjHgCWqRWvEOvCKJskLdJCz+SU= - SHA1 (openssh-8.5p1.tar.gz) = 72eadcbe313b07b1dd3b693e41d3cd56d354e24e - SHA256 (openssh-8.5p1.tar.gz) = 9S8/QdQpqpkY44zyAK8iXM3Y5m8FLaVyhwyJc3ZG7CU= Please note that the SHA256 signatures are base64 encoded and not hexadecimal (which is the default for most checksum tools). The PGP key used to sign the releases is available from the mirror sites: https://cdn.openbsd.org/pub/OpenBSD/OpenSSH/RELEASE_KEY.asc Please note that the OpenPGP key used to sign releases has been rotated for this release. The new key has been signed by the previous key to provide continuity. Reporting Bugs: =============== - Please read https://www.openssh.com/report.html Security bugs should be reported directly to openssh@openssh.com
2021-03-05 20:45:24 +03:00
M_CP_STROPT(hostbased_accepted_algos); \
M_CP_STROPT(pubkey_accepted_algos); \
Import 8.0: Security ======== This release contains mitigation for a weakness in the scp(1) tool and protocol (CVE-2019-6111): when copying files from a remote system to a local directory, scp(1) did not verify that the filenames that the server sent matched those requested by the client. This could allow a hostile server to create or clobber unexpected local files with attacker-controlled content. This release adds client-side checking that the filenames sent from the server match the command-line request, The scp protocol is outdated, inflexible and not readily fixed. We recommend the use of more modern protocols like sftp and rsync for file transfer instead. Potentially-incompatible changes ================================ This release includes a number of changes that may affect existing configurations: * scp(1): Relating to the above changes to scp(1); the scp protocol relies on the remote shell for wildcard expansion, so there is no infallible way for the client's wildcard matching to perfectly reflect the server's. If there is a difference between client and server wildcard expansion, the client may refuse files from the server. For this reason, we have provided a new "-T" flag to scp that disables these client-side checks at the risk of reintroducing the attack described above. * sshd(8): Remove support for obsolete "host/port" syntax. Slash- separated host/port was added in 2001 as an alternative to host:port syntax for the benefit of IPv6 users. These days there are establised standards for this like [::1]:22 and the slash syntax is easily mistaken for CIDR notation, which OpenSSH supports for some things. Remove the slash notation from ListenAddress and PermitOpen; bz#2335 Changes since OpenSSH 7.9 ========================= This release is focused on new features and internal refactoring. New Features ------------ * ssh(1), ssh-agent(1), ssh-add(1): Add support for ECDSA keys in PKCS#11 tokens. * ssh(1), sshd(8): Add experimental quantum-computing resistant key exchange method, based on a combination of Streamlined NTRU Prime 4591^761 and X25519. * ssh-keygen(1): Increase the default RSA key size to 3072 bits, following NIST Special Publication 800-57's guidance for a 128-bit equivalent symmetric security level. * ssh(1): Allow "PKCS11Provider=none" to override later instances of the PKCS11Provider directive in ssh_config; bz#2974 * sshd(8): Add a log message for situations where a connection is dropped for attempting to run a command but a sshd_config ForceCommand=internal-sftp restriction is in effect; bz#2960 * ssh(1): When prompting whether to record a new host key, accept the key fingerprint as a synonym for "yes". This allows the user to paste a fingerprint obtained out of band at the prompt and have the client do the comparison for you. * ssh-keygen(1): When signing multiple certificates on a single command-line invocation, allow automatically incrementing the certificate serial number. * scp(1), sftp(1): Accept -J option as an alias to ProxyJump on the scp and sftp command-lines. * ssh-agent(1), ssh-pkcs11-helper(8), ssh-add(1): Accept "-v" command-line flags to increase the verbosity of output; pass verbose flags though to subprocesses, such as ssh-pkcs11-helper started from ssh-agent. * ssh-add(1): Add a "-T" option to allowing testing whether keys in an agent are usable by performing a signature and a verification. * sftp-server(8): Add a "lsetstat@openssh.com" protocol extension that replicates the functionality of the existing SSH2_FXP_SETSTAT operation but does not follow symlinks. bz#2067 * sftp(1): Add "-h" flag to chown/chgrp/chmod commands to request they do not follow symlinks. * sshd(8): Expose $SSH_CONNECTION in the PAM environment. This makes the connection 4-tuple available to PAM modules that wish to use it in decision-making. bz#2741 * sshd(8): Add a ssh_config "Match final" predicate Matches in same pass as "Match canonical" but doesn't require hostname canonicalisation be enabled. bz#2906 * sftp(1): Support a prefix of '@' to suppress echo of sftp batch commands; bz#2926 * ssh-keygen(1): When printing certificate contents using "ssh-keygen -Lf /path/certificate", include the algorithm that the CA used to sign the cert. Bugfixes -------- * sshd(8): Fix authentication failures when sshd_config contains "AuthenticationMethods any" inside a Match block that overrides a more restrictive default. * sshd(8): Avoid sending duplicate keepalives when ClientAliveCount is enabled. * sshd(8): Fix two race conditions related to SIGHUP daemon restart. Remnant file descriptors in recently-forked child processes could block the parent sshd's attempt to listen(2) to the configured addresses. Also, the restarting parent sshd could exit before any child processes that were awaiting their re-execution state had completed reading it, leaving them in a fallback path. * ssh(1): Fix stdout potentially being redirected to /dev/null when ProxyCommand=- was in use. * sshd(8): Avoid sending SIGPIPE to child processes if they attempt to write to stderr after their parent processes have exited; bz#2071 * ssh(1): Fix bad interaction between the ssh_config ConnectTimeout and ConnectionAttempts directives - connection attempts after the first were ignoring the requested timeout; bz#2918 * ssh-keyscan(1): Return a non-zero exit status if no keys were found; bz#2903 * scp(1): Sanitize scp filenames to allow UTF-8 characters without terminal control sequences; bz#2434 * sshd(8): Fix confusion between ClientAliveInterval and time-based RekeyLimit that could cause connections to be incorrectly closed. bz#2757 * ssh(1), ssh-add(1): Correct some bugs in PKCS#11 token PIN handling at initial token login. The attempt to read the PIN could be skipped in some cases, particularly on devices with integrated PIN readers. This would lead to an inability to retrieve keys from these tokens. bz#2652 * ssh(1), ssh-add(1): Support keys on PKCS#11 tokens that set the CKA_ALWAYS_AUTHENTICATE flag by requring a fresh login after the C_SignInit operation. bz#2638 * ssh(1): Improve documentation for ProxyJump/-J, clarifying that local configuration does not apply to jump hosts. * ssh-keygen(1): Clarify manual - ssh-keygen -e only writes public keys, not private. * ssh(1), sshd(8): be more strict in processing protocol banners, allowing \r characters only immediately before \n. * Various: fix a number of memory leaks, including bz#2942 and bz#2938 * scp(1), sftp(1): fix calculation of initial bandwidth limits. Account for bytes written before the timer starts and adjust the schedule on which recalculations are performed. Avoids an initial burst of traffic and yields more accurate bandwidth limits; bz#2927 * sshd(8): Only consider the ext-info-c extension during the initial key eschange. It shouldn't be sent in subsequent ones, but if it is present we should ignore it. This prevents sshd from sending a SSH_MSG_EXT_INFO for REKEX for buggy these clients. bz#2929 * ssh-keygen(1): Clarify manual that ssh-keygen -F (find host in authorized_keys) and -R (remove host from authorized_keys) options may accept either a bare hostname or a [hostname]:port combo. bz#2935 * ssh(1): Don't attempt to connect to empty SSH_AUTH_SOCK; bz#2936 * sshd(8): Silence error messages when sshd fails to load some of the default host keys. Failure to load an explicitly-configured hostkey is still an error, and failure to load any host key is still fatal. pr/103 * ssh(1): Redirect stderr of ProxyCommands to /dev/null when ssh is started with ControlPersist; prevents random ProxyCommand output from interfering with session output. * ssh(1): The ssh client was keeping a redundant ssh-agent socket (leftover from authentication) around for the life of the connection; bz#2912 * sshd(8): Fix bug in HostbasedAcceptedKeyTypes and PubkeyAcceptedKeyTypes options. If only RSA-SHA2 siganture types were specified, then authentication would always fail for RSA keys as the monitor checks only the base key (not the signature algorithm) type against *AcceptedKeyTypes. bz#2746 * ssh(1): Request correct signature types from ssh-agent when certificate keys and RSA-SHA2 signatures are in use. Portability ----------- * sshd(8): On Cygwin, run as SYSTEM where possible, using S4U for token creation if it supports MsV1_0 S4U Logon. * sshd(8): On Cygwin, use custom user/group matching code that respects the OS' behaviour of case-insensitive matching. * sshd(8): Don't set $MAIL if UsePAM=yes as PAM typically specifies the user environment if it's enabled; bz#2937 * sshd(8) Cygwin: Change service name to cygsshd to avoid collision with Microsoft's OpenSSH port. * Allow building against OpenSSL -dev (3.x) * Fix a number of build problems against version configurations and versions of OpenSSL. Including bz#2931 and bz#2921 * Improve warnings in cygwin service setup. bz#2922 * Remove hardcoded service name in cygwin setup. bz#2922
2019-04-20 20:13:53 +03:00
M_CP_STROPT(ca_sign_algorithms); \
OpenSSH 7.7 was released on 2018-04-02. It is available from the mirrors listed at http://www.openssh.com/ shortly. OpenSSH is a 100% complete SSH protocol 2.0 implementation and includes sftp client and server support. Once again, we would like to thank the OpenSSH community for their continued support of the project, especially those who contributed code or patches, reported bugs, tested snapshots or donated to the project. More information on donations may be found at: http://www.openssh.com/donations.html Potentially-incompatible changes ================================ This release includes a number of changes that may affect existing configurations: * ssh(1)/sshd(8): Drop compatibility support for some very old SSH implementations, including ssh.com <=2.* and OpenSSH <= 3.*. These versions were all released in or before 2001 and predate the final SSH RFCs. The support in question isn't necessary for RFC-compliant SSH implementations. Changes since OpenSSH 7.6 ========================= This is primarily a bugfix release. New Features ------------ * All: Add experimental support for PQC XMSS keys (Extended Hash- Based Signatures) based on the algorithm described in https://tools.ietf.org/html/draft-irtf-cfrg-xmss-hash-based-signatures-12 The XMSS signature code is experimental and not compiled in by default. * sshd(8): Add a "rdomain" criteria for the sshd_config Match keyword to allow conditional configuration that depends on which routing domain a connection was received on (currently supported on OpenBSD and Linux). * sshd_config(5): Add an optional rdomain qualifier to the ListenAddress directive to allow listening on different routing domains. This is supported only on OpenBSD and Linux at present. * sshd_config(5): Add RDomain directive to allow the authenticated session to be placed in an explicit routing domain. This is only supported on OpenBSD at present. * sshd(8): Add "expiry-time" option for authorized_keys files to allow for expiring keys. * ssh(1): Add a BindInterface option to allow binding the outgoing connection to an interface's address (basically a more usable BindAddress) * ssh(1): Expose device allocated for tun/tap forwarding via a new %T expansion for LocalCommand. This allows LocalCommand to be used to prepare the interface. * sshd(8): Expose the device allocated for tun/tap forwarding via a new SSH_TUNNEL environment variable. This allows automatic setup of the interface and surrounding network configuration automatically on the server. * ssh(1)/scp(1)/sftp(1): Add URI support to ssh, sftp and scp, e.g. ssh://user@host or sftp://user@host/path. Additional connection parameters described in draft-ietf-secsh-scp-sftp-ssh-uri-04 are not implemented since the ssh fingerprint format in the draft uses the deprecated MD5 hash with no way to specify the any other algorithm. * ssh-keygen(1): Allow certificate validity intervals that specify only a start or stop time (instead of both or neither). * sftp(1): Allow "cd" and "lcd" commands with no explicit path argument. lcd will change to the local user's home directory as usual. cd will change to the starting directory for session (because the protocol offers no way to obtain the remote user's home directory). bz#2760 * sshd(8): When doing a config test with sshd -T, only require the attributes that are actually used in Match criteria rather than (an incomplete list of) all criteria. Bugfixes -------- * ssh(1)/sshd(8): More strictly check signature types during key exchange against what was negotiated. Prevents downgrade of RSA signatures made with SHA-256/512 to SHA-1. * sshd(8): Fix support for client that advertise a protocol version of "1.99" (indicating that they are prepared to accept both SSHv1 and SSHv2). This was broken in OpenSSH 7.6 during the removal of SSHv1 support. bz#2810 * ssh(1): Warn when the agent returns a ssh-rsa (SHA1) signature when a rsa-sha2-256/512 signature was requested. This condition is possible when an old or non-OpenSSH agent is in use. bz#2799 * ssh-agent(1): Fix regression introduced in 7.6 that caused ssh-agent to fatally exit if presented an invalid signature request message. * sshd_config(5): Accept yes/no flag options case-insensitively, as has been the case in ssh_config(5) for a long time. bz#2664 * ssh(1): Improve error reporting for failures during connection. Under some circumstances misleading errors were being shown. bz#2814 * ssh-keyscan(1): Add -D option to allow printing of results directly in SSHFP format. bz#2821 * regress tests: fix PuTTY interop test broken in last release's SSHv1 removal. bz#2823 * ssh(1): Compatibility fix for some servers that erroneously drop the connection when the IUTF8 (RFC8160) option is sent. * scp(1): Disable RemoteCommand and RequestTTY in the ssh session started by scp (sftp was already doing this.) * ssh-keygen(1): Refuse to create a certificate with an unusable number of principals. * ssh-keygen(1): Fatally exit if ssh-keygen is unable to write all the public key during key generation. Previously it would silently ignore errors writing the comment and terminating newline. * ssh(1): Do not modify hostname arguments that are addresses by automatically forcing them to lower-case. Instead canonicalise them to resolve ambiguities (e.g. ::0001 => ::1) before they are matched against known_hosts. bz#2763 * ssh(1): Don't accept junk after "yes" or "no" responses to hostkey prompts. bz#2803 * sftp(1): Have sftp print a warning about shell cleanliness when decoding the first packet fails, which is usually caused by shells polluting stdout of non-interactive startups. bz#2800 * ssh(1)/sshd(8): Switch timers in packet code from using wall-clock time to monotonic time, allowing the packet layer to better function over a clock step and avoiding possible integer overflows during steps. * Numerous manual page fixes and improvements. Portability ----------- * sshd(8): Correctly detect MIPS ABI in use at configure time. Fixes sandbox violations on some environments. * sshd(8): Remove UNICOS support. The hardware and software are literal museum pieces and support in sshd is too intrusive to justify maintaining. * All: Build and link with "retpoline" flags when available to mitigate the "branch target injection" style (variant 2) of the Spectre branch-prediction vulnerability. * All: Add auto-generated dependency information to Makefile. * Numerous fixed to the RPM spec files. Checksums: ========== - SHA1 (openssh-7.7.tar.gz) = 24812e05fa233014c847c7775748316e7f8a836c - SHA256 (openssh-7.7.tar.gz) = T4ua1L/vgAYqwB0muRahvnm5ZUr3PLY9nPljaG8egvo= - SHA1 (openssh-7.7p1.tar.gz) = 446fe9ed171f289f0d62197dffdbfdaaf21c49f2 - SHA256 (openssh-7.7p1.tar.gz) = 1zvn5oTpnvzQJL4Vowv/y+QbASsvezyQhK7WIXdea48= Please note that the SHA256 signatures are base64 encoded and not hexadecimal (which is the default for most checksum tools). The PGP key used to sign the releases is available as RELEASE_KEY.asc from the mirror sites. Reporting Bugs: =============== - Please read http://www.openssh.com/report.html Security bugs should be reported directly to openssh@openssh.com
2018-04-06 21:56:05 +03:00
M_CP_STROPT(routing_domain); \
OpenSSH 8.4 was released on 2020-09-27. It is available from the mirrors listed at https://www.openssh.com/. OpenSSH is a 100% complete SSH protocol 2.0 implementation and includes sftp client and server support. Once again, we would like to thank the OpenSSH community for their continued support of the project, especially those who contributed code or patches, reported bugs, tested snapshots or donated to the project. More information on donations may be found at: https://www.openssh.com/donations.html Future deprecation notice ========================= It is now possible[1] to perform chosen-prefix attacks against the SHA-1 algorithm for less than USD$50K. For this reason, we will be disabling the "ssh-rsa" public key signature algorithm by default in a near-future release. This algorithm is unfortunately still used widely despite the existence of better alternatives, being the only remaining public key signature algorithm specified by the original SSH RFCs. The better alternatives include: * The RFC8332 RSA SHA-2 signature algorithms rsa-sha2-256/512. These algorithms have the advantage of using the same key type as "ssh-rsa" but use the safe SHA-2 hash algorithms. These have been supported since OpenSSH 7.2 and are already used by default if the client and server support them. * The ssh-ed25519 signature algorithm. It has been supported in OpenSSH since release 6.5. * The RFC5656 ECDSA algorithms: ecdsa-sha2-nistp256/384/521. These have been supported by OpenSSH since release 5.7. To check whether a server is using the weak ssh-rsa public key algorithm, for host authentication, try to connect to it after removing the ssh-rsa algorithm from ssh(1)'s allowed list: ssh -oHostKeyAlgorithms=-ssh-rsa user@host If the host key verification fails and no other supported host key types are available, the server software on that host should be upgraded. We intend to enable UpdateHostKeys by default in the next OpenSSH release. This will assist the client by automatically migrating to better algorithms. Users may consider enabling this option manually. [1] "SHA-1 is a Shambles: First Chosen-Prefix Collision on SHA-1 and Application to the PGP Web of Trust" Leurent, G and Peyrin, T (2020) https://eprint.iacr.org/2020/014.pdf Security ======== * ssh-agent(1): restrict ssh-agent from signing web challenges for FIDO/U2F keys. When signing messages in ssh-agent using a FIDO key that has an application string that does not start with "ssh:", ensure that the message being signed is one of the forms expected for the SSH protocol (currently public key authentication and sshsig signatures). This prevents ssh-agent forwarding on a host that has FIDO keys attached granting the ability for the remote side to sign challenges for web authentication using those keys too. Note that the converse case of web browsers signing SSH challenges is already precluded because no web RP can have the "ssh:" prefix in the application string that we require. * ssh-keygen(1): Enable FIDO 2.1 credProtect extension when generating a FIDO resident key. The recent FIDO 2.1 Client to Authenticator Protocol introduced a "credProtect" feature to better protect resident keys. We use this option to require a PIN prior to all operations that may retrieve a resident key from a FIDO token. Potentially-incompatible changes ================================ This release includes a number of changes that may affect existing configurations: * For FIDO/U2F support, OpenSSH recommends the use of libfido2 1.5.0 or greater. Older libraries have limited support at the expense of disabling particular features. These include resident keys, PIN- required keys and multiple attached tokens. * ssh-keygen(1): the format of the attestation information optionally recorded when a FIDO key is generated has changed. It now includes the authenticator data needed to validate attestation signatures. * The API between OpenSSH and the FIDO token middleware has changed and the SSH_SK_VERSION_MAJOR version has been incremented as a result. Third-party middleware libraries must support the current API version (7) to work with OpenSSH 8.4. * The portable OpenSSH distribution now requires automake to rebuild the configure script and supporting files. This is not required when simply building portable OpenSSH from a release tar file. Changes since OpenSSH 8.3 ========================= New features ------------ * ssh(1), ssh-keygen(1): support for FIDO keys that require a PIN for each use. These keys may be generated using ssh-keygen using a new "verify-required" option. When a PIN-required key is used, the user will be prompted for a PIN to complete the signature operation. * sshd(8): authorized_keys now supports a new "verify-required" option to require FIDO signatures assert that the token verified that the user was present before making the signature. The FIDO protocol supports multiple methods for user-verification, but currently OpenSSH only supports PIN verification. * sshd(8), ssh-keygen(1): add support for verifying FIDO webauthn signatures. Webauthn is a standard for using FIDO keys in web browsers. These signatures are a slightly different format to plain FIDO signatures and thus require explicit support. * ssh(1): allow some keywords to expand shell-style ${ENV} environment variables. The supported keywords are CertificateFile, ControlPath, IdentityAgent and IdentityFile, plus LocalForward and RemoteForward when used for Unix domain socket paths. bz#3140 * ssh(1), ssh-agent(1): allow some additional control over the use of ssh-askpass via a new $SSH_ASKPASS_REQUIRE environment variable, including forcibly enabling and disabling its use. bz#69 * ssh(1): allow ssh_config(5)'s AddKeysToAgent keyword accept a time limit for keys in addition to its current flag options. Time- limited keys will automatically be removed from ssh-agent after their expiry time has passed. * scp(1), sftp(1): allow the -A flag to explicitly enable agent forwarding in scp and sftp. The default remains to not forward an agent, even when ssh_config enables it. * ssh(1): add a '%k' TOKEN that expands to the effective HostKey of the destination. This allows, e.g., keeping host keys in individual files using "UserKnownHostsFile ~/.ssh/known_hosts.d/%k". bz#1654 * ssh(1): add %-TOKEN, environment variable and tilde expansion to the UserKnownHostsFile directive, allowing the path to be completed by the configuration (e.g. bz#1654) * ssh-keygen(1): allow "ssh-add -d -" to read keys to be deleted from stdin. bz#3180 * sshd(8): improve logging for MaxStartups connection throttling. sshd will now log when it starts and stops throttling and periodically while in this state. bz#3055 Bugfixes -------- * ssh(1), ssh-keygen(1): better support for multiple attached FIDO tokens. In cases where OpenSSH cannot unambiguously determine which token to direct a request to, the user is now required to select a token by touching it. In cases of operations that require a PIN to be verified, this avoids sending the wrong PIN to the wrong token and incrementing the token's PIN failure counter (tokens effectively erase their keys after too many PIN failures). * sshd(8): fix Include before Match in sshd_config; bz#3122 * ssh(1): close stdin/out/error when forking after authentication completes ("ssh -f ...") bz#3137 * ssh(1), sshd(8): limit the amount of channel input data buffered, avoiding peers that advertise large windows but are slow to read from causing high memory consumption. * ssh-agent(1): handle multiple requests sent in a single write() to the agent. * sshd(8): allow sshd_config longer than 256k * sshd(8): avoid spurious "Unable to load host key" message when sshd load a private key but no public counterpart * ssh(1): prefer the default hostkey algorithm list whenever we have a hostkey that matches its best-preference algorithm. * sshd(1): when ordering the hostkey algorithms to request from a server, prefer certificate types if the known_hosts files contain a key marked as a @cert-authority; bz#3157 * ssh(1): perform host key fingerprint comparisons for the "Are you sure you want to continue connecting (yes/no/[fingerprint])?" prompt with case sensitivity. * sshd(8): ensure that address/masklen mismatches in sshd_config yield fatal errors at daemon start time rather than later when they are evaluated. * ssh-keygen(1): ensure that certificate extensions are lexically sorted. Previously if the user specified a custom extension then the everything would be in order except the custom ones. bz#3198 * ssh(1): also compare username when checking for JumpHost loops. bz#3057 * ssh-keygen(1): preserve group/world read permission on known_hosts files across runs of "ssh-keygen -Rf /path". The old behaviour was to remove all rights for group/other. bz#3146 * ssh-keygen(1): Mention the [-a rounds] flag in the ssh-keygen manual page and usage(). * sshd(8): explicitly construct path to ~/.ssh/rc rather than relying on it being relative to the current directory, so that it can still be found if the shell startup changes its directory. bz#3185 * sshd(8): when redirecting sshd's log output to a file, undo this redirection after the session child process is forked(). Fixes missing log messages when using this feature under some circumstances. * sshd(8): start ClientAliveInterval bookkeeping before first pass through select() loop; fixed theoretical case where busy sshd may ignore timeouts from client. * ssh(1): only reset the ServerAliveInterval check when we receive traffic from the server and ignore traffic from a port forwarding client, preventing a client from keeping a connection alive when it should be terminated. bz#2265 * ssh-keygen(1): avoid spurious error message when ssh-keygen creates files outside ~/.ssh * sftp-client(1): fix off-by-one error that caused sftp downloads to make one more concurrent request that desired. This prevented using sftp(1) in unpipelined request/response mode, which is useful when debugging. bz#3054 * ssh(1), sshd(8): handle EINTR in waitfd() and timeout_connect() helpers. bz#3071 * ssh(1), ssh-keygen(1): defer creation of ~/.ssh until we attempt to write to it so we don't leave an empty .ssh directory when it's not needed. bz#3156 * ssh(1), sshd(8): fix multiplier when parsing time specifications when handling seconds after other units. bz#3171 Portability ----------- * sshd(8): always send any PAM account messages. If the PAM account stack returns any messages, always send them to the user and not just if the check succeeds. bz#2049 * Implement some backwards compatibility for libfido2 libraries older than 1.5.0. Note that use of an older library will result in the loss of certain features including resident key support, PIN support and support for multiple attached tokens. * configure fixes for XCode 12 * gnome-ssh-askpass3: ensure the "close" button is not focused by default for SSH_ASKPASS_PROMPT=none prompts. Avoids space/enter accidentally dismissing FIDO touch notifications. * gnome-ssh-askpass3: allow some control over textarea colour via $GNOME_SSH_ASKPASS_FG_COLOR and $GNOME_SSH_ASKPASS_BG_COLOR environment variables. * sshd(8): document another PAM spec problem in a frustrated comment * sshd(8): support NetBSD's utmpx.ut_ss address field. bz#960 * Add the ssh-sk-helper binary and its manpage to the RPM spec file * Detect the Frankenstein monster of Linux/X32 and allow the sandbox to function there. bz#3085
2020-12-04 21:40:04 +03:00
M_CP_STROPT(permit_user_env_allowlist); \
new openssh: See http://www.openssh.com/txt/release-5.9
2011-09-07 00:16:49 +04:00
M_CP_STRARRAYOPT(authorized_keys_files, num_authkeys_files); \
From ftp.openbsd.org
2012-12-12 20:52:18 +04:00
M_CP_STRARRAYOPT(allow_users, num_allow_users); \
M_CP_STRARRAYOPT(deny_users, num_deny_users); \
M_CP_STRARRAYOPT(allow_groups, num_allow_groups); \
M_CP_STRARRAYOPT(deny_groups, num_deny_groups); \
M_CP_STRARRAYOPT(accept_env, num_accept_env); \
OpenSSH 8.5/8.5p1 (2021-03-03) OpenSSH 8.5 was released on 2021-03-03. It is available from the mirrors listed at https://www.openssh.com/. OpenSSH is a 100% complete SSH protocol 2.0 implementation and includes sftp client and server support. Once again, we would like to thank the OpenSSH community for their continued support of the project, especially those who contributed code or patches, reported bugs, tested snapshots or donated to the project. More information on donations may be found at: https://www.openssh.com/donations.html Future deprecation notice ========================= It is now possible[1] to perform chosen-prefix attacks against the SHA-1 algorithm for less than USD$50K. In the SSH protocol, the "ssh-rsa" signature scheme uses the SHA-1 hash algorithm in conjunction with the RSA public key algorithm. OpenSSH will disable this signature scheme by default in the near future. Note that the deactivation of "ssh-rsa" signatures does not necessarily require cessation of use for RSA keys. In the SSH protocol, keys may be capable of signing using multiple algorithms. In particular, "ssh-rsa" keys are capable of signing using "rsa-sha2-256" (RSA/SHA256), "rsa-sha2-512" (RSA/SHA512) and "ssh-rsa" (RSA/SHA1). Only the last of these is being turned off by default. This algorithm is unfortunately still used widely despite the existence of better alternatives, being the only remaining public key signature algorithm specified by the original SSH RFCs that is still enabled by default. The better alternatives include: * The RFC8332 RSA SHA-2 signature algorithms rsa-sha2-256/512. These algorithms have the advantage of using the same key type as "ssh-rsa" but use the safe SHA-2 hash algorithms. These have been supported since OpenSSH 7.2 and are already used by default if the client and server support them. * The RFC8709 ssh-ed25519 signature algorithm. It has been supported in OpenSSH since release 6.5. * The RFC5656 ECDSA algorithms: ecdsa-sha2-nistp256/384/521. These have been supported by OpenSSH since release 5.7. To check whether a server is using the weak ssh-rsa public key algorithm, for host authentication, try to connect to it after removing the ssh-rsa algorithm from ssh(1)'s allowed list: ssh -oHostKeyAlgorithms=-ssh-rsa user@host If the host key verification fails and no other supported host key types are available, the server software on that host should be upgraded. This release enables the UpdateHostKeys option by default to assist the client by automatically migrating to better algorithms. [1] "SHA-1 is a Shambles: First Chosen-Prefix Collision on SHA-1 and Application to the PGP Web of Trust" Leurent, G and Peyrin, T (2020) https://eprint.iacr.org/2020/014.pdf Security ======== * ssh-agent(1): fixed a double-free memory corruption that was introduced in OpenSSH 8.2 . We treat all such memory faults as potentially exploitable. This bug could be reached by an attacker with access to the agent socket. On modern operating systems where the OS can provide information about the user identity connected to a socket, OpenSSH ssh-agent and sshd limit agent socket access only to the originating user and root. Additional mitigation may be afforded by the system's malloc(3)/free(3) implementation, if it detects double-free conditions. The most likely scenario for exploitation is a user forwarding an agent either to an account shared with a malicious user or to a host with an attacker holding root access. * Portable sshd(8): Prevent excessively long username going to PAM. This is a mitigation for a buffer overflow in Solaris' PAM username handling (CVE-2020-14871), and is only enabled for Sun-derived PAM implementations. This is not a problem in sshd itself, it only prevents sshd from being used as a vector to attack Solaris' PAM. It does not prevent the bug in PAM from being exploited via some other PAM application. GHPR212 Potentially-incompatible changes ================================ This release includes a number of changes that may affect existing configurations: * ssh(1), sshd(8): this release changes the first-preference signature algorithm from ECDSA to ED25519. * ssh(1), sshd(8): set the TOS/DSCP specified in the configuration for interactive use prior to TCP connect. The connection phase of the SSH session is time-sensitive and often explicitly interactive. The ultimate interactive/bulk TOS/DSCP will be set after authentication completes. * ssh(1), sshd(8): remove the pre-standardization cipher rijndael-cbc@lysator.liu.se. It is an alias for aes256-cbc before it was standardized in RFC4253 (2006), has been deprecated and disabled by default since OpenSSH 7.2 (2016) and was only briefly documented in ssh.1 in 2001. * ssh(1), sshd(8): update/replace the experimental post-quantum hybrid key exchange method based on Streamlined NTRU Prime coupled with X25519. The previous sntrup4591761x25519-sha512@tinyssh.org method is replaced with sntrup761x25519-sha512@openssh.com. Per its designers, the sntrup4591761 algorithm was superseded almost two years ago by sntrup761. (note this both the updated method and the one that it replaced are disabled by default) * ssh(1): disable CheckHostIP by default. It provides insignificant benefits while making key rotation significantly more difficult, especially for hosts behind IP-based load-balancers. Changes since OpenSSH 8.4 ========================= New features ------------ * ssh(1): this release enables UpdateHostkeys by default subject to some conservative preconditions: - The key was matched in the UserKnownHostsFile (and not in the GlobalKnownHostsFile). - The same key does not exist under another name. - A certificate host key is not in use. - known_hosts contains no matching wildcard hostname pattern. - VerifyHostKeyDNS is not enabled. - The default UserKnownHostsFile is in use. We expect some of these conditions will be modified or relaxed in future. * ssh(1), sshd(8): add a new LogVerbose configuration directive for that allows forcing maximum debug logging by file/function/line pattern-lists. * ssh(1): when prompting the user to accept a new hostkey, display any other host names/addresses already associated with the key. * ssh(1): allow UserKnownHostsFile=none to indicate that no known_hosts file should be used to identify host keys. * ssh(1): add a ssh_config KnownHostsCommand option that allows the client to obtain known_hosts data from a command in addition to the usual files. * ssh(1): add a ssh_config PermitRemoteOpen option that allows the client to restrict the destination when RemoteForward is used with SOCKS. * ssh(1): for FIDO keys, if a signature operation fails with a "incorrect PIN" reason and no PIN was initially requested from the user, then request a PIN and retry the operation. This supports some biometric devices that fall back to requiring PIN when reading of the biometric failed, and devices that require PINs for all hosted credentials. * sshd(8): implement client address-based rate-limiting via new sshd_config(5) PerSourceMaxStartups and PerSourceNetBlockSize directives that provide more fine-grained control on a per-origin address basis than the global MaxStartups limit. Bugfixes -------- * ssh(1): Prefix keyboard interactive prompts with "(user@host)" to make it easier to determine which connection they are associated with in cases like scp -3, ProxyJump, etc. bz#3224 * sshd(8): fix sshd_config SetEnv directives located inside Match blocks. GHPR201 * ssh(1): when requesting a FIDO token touch on stderr, inform the user once the touch has been recorded. * ssh(1): prevent integer overflow when ridiculously large ConnectTimeout values are specified, capping the effective value (for most platforms) at 24 days. bz#3229 * ssh(1): consider the ECDSA key subtype when ordering host key algorithms in the client. * ssh(1), sshd(8): rename the PubkeyAcceptedKeyTypes keyword to PubkeyAcceptedAlgorithms. The previous name incorrectly suggested that it control allowed key algorithms, when this option actually specifies the signature algorithms that are accepted. The previous name remains available as an alias. bz#3253 * ssh(1), sshd(8): similarly, rename HostbasedKeyTypes (ssh) and HostbasedAcceptedKeyTypes (sshd) to HostbasedAcceptedAlgorithms. * sftp-server(8): add missing lsetstat@openssh.com documentation and advertisement in the server's SSH2_FXP_VERSION hello packet. * ssh(1), sshd(8): more strictly enforce KEX state-machine by banning packet types once they are received. Fixes memleak caused by duplicate SSH2_MSG_KEX_DH_GEX_REQUEST (oss-fuzz #30078). * sftp(1): allow the full range of UIDs/GIDs for chown/chgrp on 32bit platforms instead of being limited by LONG_MAX. bz#3206 * Minor man page fixes (capitalization, commas, etc.) bz#3223 * sftp(1): when doing an sftp recursive upload or download of a read-only directory, ensure that the directory is created with write and execute permissions in the interim so that the transfer can actually complete, then set the directory permission as the final step. bz#3222 * ssh-keygen(1): document the -Z, check the validity of its argument earlier and provide a better error message if it's not correct. bz#2879 * ssh(1): ignore comments at the end of config lines in ssh_config, similar to what we already do for sshd_config. bz#2320 * sshd_config(5): mention that DisableForwarding is valid in a sshd_config Match block. bz3239 * sftp(1): fix incorrect sorting of "ls -ltr" under some circumstances. bz3248. * ssh(1), sshd(8): fix potential integer truncation of (unlikely) timeout values. bz#3250 * ssh(1): make hostbased authentication send the signature algorithm in its SSH2_MSG_USERAUTH_REQUEST packets instead of the key type. This make HostbasedAcceptedAlgorithms do what it is supposed to - filter on signature algorithm and not key type. Portability ----------- * sshd(8): add a number of platform-specific syscalls to the Linux seccomp-bpf sandbox. bz#3232 bz#3260 * sshd(8): remove debug message from sigchld handler that could cause deadlock on some platforms. bz#3259 * Sync contrib/ssh-copy-id with upstream. * unittests: add a hostname function for systems that don't have it. Some systems don't have a hostname command (it's not required by POSIX). The do have uname -n (which is), but not all of those have it report the FQDN. Checksums: ========== - SHA1 (openssh-8.5.tar.gz) = 04cae43c389fb411227c01219e4eb46e3113f34e - SHA256 (openssh-8.5.tar.gz) = 5qB2CgzNG4io4DmChTjHgCWqRWvEOvCKJskLdJCz+SU= - SHA1 (openssh-8.5p1.tar.gz) = 72eadcbe313b07b1dd3b693e41d3cd56d354e24e - SHA256 (openssh-8.5p1.tar.gz) = 9S8/QdQpqpkY44zyAK8iXM3Y5m8FLaVyhwyJc3ZG7CU= Please note that the SHA256 signatures are base64 encoded and not hexadecimal (which is the default for most checksum tools). The PGP key used to sign the releases is available from the mirror sites: https://cdn.openbsd.org/pub/OpenBSD/OpenSSH/RELEASE_KEY.asc Please note that the OpenPGP key used to sign releases has been rotated for this release. The new key has been signed by the previous key to provide continuity. Reporting Bugs: =============== - Please read https://www.openssh.com/report.html Security bugs should be reported directly to openssh@openssh.com
2021-03-05 20:45:24 +03:00
M_CP_STRARRAYOPT(setenv, num_setenv); \
from openbsd
2013-03-29 18:52:38 +04:00
M_CP_STRARRAYOPT(auth_methods, num_auth_methods); \
OpenSSH 7.7 was released on 2018-04-02. It is available from the mirrors listed at http://www.openssh.com/ shortly. OpenSSH is a 100% complete SSH protocol 2.0 implementation and includes sftp client and server support. Once again, we would like to thank the OpenSSH community for their continued support of the project, especially those who contributed code or patches, reported bugs, tested snapshots or donated to the project. More information on donations may be found at: http://www.openssh.com/donations.html Potentially-incompatible changes ================================ This release includes a number of changes that may affect existing configurations: * ssh(1)/sshd(8): Drop compatibility support for some very old SSH implementations, including ssh.com <=2.* and OpenSSH <= 3.*. These versions were all released in or before 2001 and predate the final SSH RFCs. The support in question isn't necessary for RFC-compliant SSH implementations. Changes since OpenSSH 7.6 ========================= This is primarily a bugfix release. New Features ------------ * All: Add experimental support for PQC XMSS keys (Extended Hash- Based Signatures) based on the algorithm described in https://tools.ietf.org/html/draft-irtf-cfrg-xmss-hash-based-signatures-12 The XMSS signature code is experimental and not compiled in by default. * sshd(8): Add a "rdomain" criteria for the sshd_config Match keyword to allow conditional configuration that depends on which routing domain a connection was received on (currently supported on OpenBSD and Linux). * sshd_config(5): Add an optional rdomain qualifier to the ListenAddress directive to allow listening on different routing domains. This is supported only on OpenBSD and Linux at present. * sshd_config(5): Add RDomain directive to allow the authenticated session to be placed in an explicit routing domain. This is only supported on OpenBSD at present. * sshd(8): Add "expiry-time" option for authorized_keys files to allow for expiring keys. * ssh(1): Add a BindInterface option to allow binding the outgoing connection to an interface's address (basically a more usable BindAddress) * ssh(1): Expose device allocated for tun/tap forwarding via a new %T expansion for LocalCommand. This allows LocalCommand to be used to prepare the interface. * sshd(8): Expose the device allocated for tun/tap forwarding via a new SSH_TUNNEL environment variable. This allows automatic setup of the interface and surrounding network configuration automatically on the server. * ssh(1)/scp(1)/sftp(1): Add URI support to ssh, sftp and scp, e.g. ssh://user@host or sftp://user@host/path. Additional connection parameters described in draft-ietf-secsh-scp-sftp-ssh-uri-04 are not implemented since the ssh fingerprint format in the draft uses the deprecated MD5 hash with no way to specify the any other algorithm. * ssh-keygen(1): Allow certificate validity intervals that specify only a start or stop time (instead of both or neither). * sftp(1): Allow "cd" and "lcd" commands with no explicit path argument. lcd will change to the local user's home directory as usual. cd will change to the starting directory for session (because the protocol offers no way to obtain the remote user's home directory). bz#2760 * sshd(8): When doing a config test with sshd -T, only require the attributes that are actually used in Match criteria rather than (an incomplete list of) all criteria. Bugfixes -------- * ssh(1)/sshd(8): More strictly check signature types during key exchange against what was negotiated. Prevents downgrade of RSA signatures made with SHA-256/512 to SHA-1. * sshd(8): Fix support for client that advertise a protocol version of "1.99" (indicating that they are prepared to accept both SSHv1 and SSHv2). This was broken in OpenSSH 7.6 during the removal of SSHv1 support. bz#2810 * ssh(1): Warn when the agent returns a ssh-rsa (SHA1) signature when a rsa-sha2-256/512 signature was requested. This condition is possible when an old or non-OpenSSH agent is in use. bz#2799 * ssh-agent(1): Fix regression introduced in 7.6 that caused ssh-agent to fatally exit if presented an invalid signature request message. * sshd_config(5): Accept yes/no flag options case-insensitively, as has been the case in ssh_config(5) for a long time. bz#2664 * ssh(1): Improve error reporting for failures during connection. Under some circumstances misleading errors were being shown. bz#2814 * ssh-keyscan(1): Add -D option to allow printing of results directly in SSHFP format. bz#2821 * regress tests: fix PuTTY interop test broken in last release's SSHv1 removal. bz#2823 * ssh(1): Compatibility fix for some servers that erroneously drop the connection when the IUTF8 (RFC8160) option is sent. * scp(1): Disable RemoteCommand and RequestTTY in the ssh session started by scp (sftp was already doing this.) * ssh-keygen(1): Refuse to create a certificate with an unusable number of principals. * ssh-keygen(1): Fatally exit if ssh-keygen is unable to write all the public key during key generation. Previously it would silently ignore errors writing the comment and terminating newline. * ssh(1): Do not modify hostname arguments that are addresses by automatically forcing them to lower-case. Instead canonicalise them to resolve ambiguities (e.g. ::0001 => ::1) before they are matched against known_hosts. bz#2763 * ssh(1): Don't accept junk after "yes" or "no" responses to hostkey prompts. bz#2803 * sftp(1): Have sftp print a warning about shell cleanliness when decoding the first packet fails, which is usually caused by shells polluting stdout of non-interactive startups. bz#2800 * ssh(1)/sshd(8): Switch timers in packet code from using wall-clock time to monotonic time, allowing the packet layer to better function over a clock step and avoiding possible integer overflows during steps. * Numerous manual page fixes and improvements. Portability ----------- * sshd(8): Correctly detect MIPS ABI in use at configure time. Fixes sandbox violations on some environments. * sshd(8): Remove UNICOS support. The hardware and software are literal museum pieces and support in sshd is too intrusive to justify maintaining. * All: Build and link with "retpoline" flags when available to mitigate the "branch target injection" style (variant 2) of the Spectre branch-prediction vulnerability. * All: Add auto-generated dependency information to Makefile. * Numerous fixed to the RPM spec files. Checksums: ========== - SHA1 (openssh-7.7.tar.gz) = 24812e05fa233014c847c7775748316e7f8a836c - SHA256 (openssh-7.7.tar.gz) = T4ua1L/vgAYqwB0muRahvnm5ZUr3PLY9nPljaG8egvo= - SHA1 (openssh-7.7p1.tar.gz) = 446fe9ed171f289f0d62197dffdbfdaaf21c49f2 - SHA256 (openssh-7.7p1.tar.gz) = 1zvn5oTpnvzQJL4Vowv/y+QbASsvezyQhK7WIXdea48= Please note that the SHA256 signatures are base64 encoded and not hexadecimal (which is the default for most checksum tools). The PGP key used to sign the releases is available as RELEASE_KEY.asc from the mirror sites. Reporting Bugs: =============== - Please read http://www.openssh.com/report.html Security bugs should be reported directly to openssh@openssh.com
2018-04-06 21:56:05 +03:00
M_CP_STRARRAYOPT(permitted_opens, num_permitted_opens); \
Potentially-incompatible changes ================================ This release includes a number of changes that may affect existing configurations: * ssh-keygen(1): write OpenSSH format private keys by default instead of using OpenSSL's PEM format. The OpenSSH format, supported in OpenSSH releases since 2014 and described in the PROTOCOL.key file in the source distribution, offers substantially better protection against offline password guessing and supports key comments in private keys. If necessary, it is possible to write old PEM-style keys by adding "-m PEM" to ssh-keygen's arguments when generating or updating a key. * sshd(8): remove internal support for S/Key multiple factor authentication. S/Key may still be used via PAM or BSD auth. * ssh(1): remove vestigal support for running ssh(1) as setuid. This used to be required for hostbased authentication and the (long gone) rhosts-style authentication, but has not been necessary for a long time. Attempting to execute ssh as a setuid binary, or with uid != effective uid will now yield a fatal error at runtime. * sshd(8): the semantics of PubkeyAcceptedKeyTypes and the similar HostbasedAcceptedKeyTypes options have changed. These now specify signature algorithms that are accepted for their respective authentication mechanism, where previously they specified accepted key types. This distinction matters when using the RSA/SHA2 signature algorithms "rsa-sha2-256", "rsa-sha2-512" and their certificate counterparts. Configurations that override these options but omit these algorithm names may cause unexpected authentication failures (no action is required for configurations that accept the default for these options). * sshd(8): the precedence of session environment variables has changed. ~/.ssh/environment and environment="..." options in authorized_keys files can no longer override SSH_* variables set implicitly by sshd. * ssh(1)/sshd(8): the default IPQoS used by ssh/sshd has changed. They will now use DSCP AF21 for interactive traffic and CS1 for bulk. For a detailed rationale, please see the commit message: https://cvsweb.openbsd.org/src/usr.bin/ssh/readconf.c#rev1.284
2018-08-26 10:39:56 +03:00
M_CP_STRARRAYOPT(permitted_listens, num_permitted_listens); \
Import OpenSSH 9.3 + the fix from p2 for the PKCS#11 remote provider The previous version was OpenSSH 9.1 OpenSSH 9.3p2 (2023-07-19) OpenSSH 9.3p2 was released on 2023-07-19. It is available from the mirrors listed at https://www.openssh.com/. OpenSSH is a 100% complete SSH protocol 2.0 implementation and includes sftp client and server support. Once again, we would like to thank the OpenSSH community for their continued support of the project, especially those who contributed code or patches, reported bugs, tested snapshots or donated to the project. More information on donations may be found at: https://www.openssh.com/donations.html Changes since OpenSSH 9.3 ========================= This release fixes a security bug. Security ======== Fix CVE-2023-38408 - a condition where specific libaries loaded via ssh-agent(1)'s PKCS#11 support could be abused to achieve remote code execution via a forwarded agent socket if the following conditions are met: * Exploitation requires the presence of specific libraries on the victim system. * Remote exploitation requires that the agent was forwarded to an attacker-controlled system. Exploitation can also be prevented by starting ssh-agent(1) with an empty PKCS#11/FIDO allowlist (ssh-agent -P '') or by configuring an allowlist that contains only specific provider libraries. This vulnerability was discovered and demonstrated to be exploitable by the Qualys Security Advisory team. In addition to removing the main precondition for exploitation, this release removes the ability for remote ssh-agent(1) clients to load PKCS#11 modules by default (see below). Potentially-incompatible changes -------------------------------- * ssh-agent(8): the agent will now refuse requests to load PKCS#11 modules issued by remote clients by default. A flag has been added to restore the previous behaviour "-Oallow-remote-pkcs11". Note that ssh-agent(8) depends on the SSH client to identify requests that are remote. The OpenSSH >=8.9 ssh(1) client does this, but forwarding access to an agent socket using other tools may circumvent this restriction. Checksums: ========== - SHA1 (openssh-9.3p2.tar.gz) = 219cf700c317f400bb20b001c0406056f7188ea4 - SHA256 (openssh-9.3p2.tar.gz) = IA6+FH9ss/EB/QzfngJEKvfdyimN/9n0VoeOfMrGdug= Please note that the SHA256 signatures are base64 encoded and not hexadecimal (which is the default for most checksum tools). The PGP key used to sign the releases is available from the mirror sites: https://cdn.openbsd.org/pub/OpenBSD/OpenSSH/RELEASE_KEY.asc Reporting Bugs: =============== - Please read https://www.openssh.com/report.html Security bugs should be reported directly to openssh@openssh.com OpenSSH 9.3/9.3p1 (2023-03-15) OpenSSH 9.3 was released on 2023-03-15. It is available from the mirrors listed at https://www.openssh.com/. OpenSSH is a 100% complete SSH protocol 2.0 implementation and includes sftp client and server support. Once again, we would like to thank the OpenSSH community for their continued support of the project, especially those who contributed code or patches, reported bugs, tested snapshots or donated to the project. More information on donations may be found at: https://www.openssh.com/donations.html Changes since OpenSSH 9.2 ========================= This release fixes a number of security bugs. Security ======== This release contains fixes for a security problem and a memory safety problem. The memory safety problem is not believed to be exploitable, but we report most network-reachable memory faults as security bugs. * ssh-add(1): when adding smartcard keys to ssh-agent(1) with the per-hop destination constraints (ssh-add -h ...) added in OpenSSH 8.9, a logic error prevented the constraints from being communicated to the agent. This resulted in the keys being added without constraints. The common cases of non-smartcard keys and keys without destination constraints are unaffected. This problem was reported by Luci Stanescu. * ssh(1): Portable OpenSSH provides an implementation of the getrrsetbyname(3) function if the standard library does not provide it, for use by the VerifyHostKeyDNS feature. A specifically crafted DNS response could cause this function to perform an out-of-bounds read of adjacent stack data, but this condition does not appear to be exploitable beyond denial-of- service to the ssh(1) client. The getrrsetbyname(3) replacement is only included if the system's standard library lacks this function and portable OpenSSH was not compiled with the ldns library (--with-ldns). getrrsetbyname(3) is only invoked if using VerifyHostKeyDNS to fetch SSHFP records. This problem was found by the Coverity static analyzer. New features ------------ * ssh-keygen(1), ssh-keyscan(1): accept -Ohashalg=sha1|sha256 when outputting SSHFP fingerprints to allow algorithm selection. bz3493 * sshd(8): add a `sshd -G` option that parses and prints the effective configuration without attempting to load private keys and perform other checks. This allows usage of the option before keys have been generated and for configuration evaluation and verification by unprivileged users. Bugfixes -------- * scp(1), sftp(1): fix progressmeter corruption on wide displays; bz3534 * ssh-add(1), ssh-keygen(1): use RSA/SHA256 when testing usability of private keys as some systems are starting to disable RSA/SHA1 in libcrypto. * sftp-server(8): fix a memory leak. GHPR363 * ssh(1), sshd(8), ssh-keyscan(1): remove vestigal protocol compatibility code and simplify what's left. * Fix a number of low-impact Coverity static analysis findings. These include several reported via bz2687 * ssh_config(5), sshd_config(5): mention that some options are not first-match-wins. * Rework logging for the regression tests. Regression tests will now capture separate logs for each ssh and sshd invocation in a test. * ssh(1): make `ssh -Q CASignatureAlgorithms` work as the manpage says it should; bz3532. * ssh(1): ensure that there is a terminating newline when adding a new entry to known_hosts; bz3529 Portability ----------- * sshd(8): harden Linux seccomp sandbox. Move to an allowlist of mmap(2), madvise(2) and futex(2) flags, removing some concerning kernel attack surface. * sshd(8): improve Linux seccomp-bpf sandbox for older systems; bz3537 Checksums: ========== - SHA1 (openssh-9.3.tar.gz) = 5f9d2f73ddfe94f3f0a78bdf46704b6ad7b66ec7 - SHA256 (openssh-9.3.tar.gz) = eRcXkFZByz70DUBUcyIdvU0pVxP2X280FrmV8pyUdrk= - SHA1 (openssh-9.3p1.tar.gz) = 610959871bf8d6baafc3525811948f85b5dd84ab - SHA256 (openssh-9.3p1.tar.gz) = 6bq6dwGnalHz2Fpiw4OjydzZf6kAuFm8fbEUwYaK+Kg= Please note that the SHA256 signatures are base64 encoded and not hexadecimal (which is the default for most checksum tools). The PGP key used to sign the releases is available from the mirror sites: https://cdn.openbsd.org/pub/OpenBSD/OpenSSH/RELEASE_KEY.asc Reporting Bugs: =============== - Please read https://www.openssh.com/report.html Security bugs should be reported directly to openssh@openssh.com OpenSSH 9.2/9.2p1 (2023-02-02) OpenSSH 9.2 was released on 2023-02-02. It is available from the mirrors listed at https://www.openssh.com/. OpenSSH is a 100% complete SSH protocol 2.0 implementation and includes sftp client and server support. Once again, we would like to thank the OpenSSH community for their continued support of the project, especially those who contributed code or patches, reported bugs, tested snapshots or donated to the project. More information on donations may be found at: https://www.openssh.com/donations.html Changes since OpenSSH 9.1 ========================= This release fixes a number of security bugs. Security ======== This release contains fixes for two security problems and a memory safety problem. The memory safety problem is not believed to be exploitable, but we report most network-reachable memory faults as security bugs. * sshd(8): fix a pre-authentication double-free memory fault introduced in OpenSSH 9.1. This is not believed to be exploitable, and it occurs in the unprivileged pre-auth process that is subject to chroot(2) and is further sandboxed on most major platforms. * ssh(8): in OpenSSH releases after 8.7, the PermitRemoteOpen option would ignore its first argument unless it was one of the special keywords "any" or "none", causing the permission list to fail open if only one permission was specified. bz3515 * ssh(1): if the CanonicalizeHostname and CanonicalizePermittedCNAMEs options were enabled, and the system/libc resolver did not check that names in DNS responses were valid, then use of these options could allow an attacker with control of DNS to include invalid characters (possibly including wildcards) in names added to known_hosts files when they were updated. These names would still have to match the CanonicalizePermittedCNAMEs allow-list, so practical exploitation appears unlikely. Potentially-incompatible changes -------------------------------- * ssh(1): add a new EnableEscapeCommandline ssh_config(5) option that controls whether the client-side ~C escape sequence that provides a command-line is available. Among other things, the ~C command-line could be used to add additional port-forwards at runtime. This option defaults to "no", disabling the ~C command-line that was previously enabled by default. Turning off the command-line allows platforms that support sandboxing of the ssh(1) client (currently only OpenBSD) to use a stricter default sandbox policy. New features ------------ * sshd(8): add support for channel inactivity timeouts via a new sshd_config(5) ChannelTimeout directive. This allows channels that have not seen traffic in a configurable interval to be automatically closed. Different timeouts may be applied to session, X11, agent and TCP forwarding channels. * sshd(8): add a sshd_config UnusedConnectionTimeout option to terminate client connections that have no open channels for a length of time. This complements the ChannelTimeout option above. * sshd(8): add a -V (version) option to sshd like the ssh client has. * ssh(1): add a "Host" line to the output of ssh -G showing the original hostname argument. bz3343 * scp(1), sftp(1): add a -X option to both scp(1) and sftp(1) to allow control over some SFTP protocol parameters: the copy buffer length and the number of in-flight requests, both of which are used during upload/download. Previously these could be controlled in sftp(1) only. This makes them available in both SFTP protocol clients using the same option character sequence. * ssh-keyscan(1): allow scanning of complete CIDR address ranges, e.g. "ssh-keyscan 192.168.0.0/24". If a CIDR range is passed, then it will be expanded to all possible addresses in the range including the all-0s and all-1s addresses. bz#976 * ssh(1): support dynamic remote port forwarding in escape command-line's -R processing. bz#3499 Bugfixes -------- * ssh(1): when restoring non-blocking mode to stdio fds, restore exactly the flags that ssh started with and don't just clobber them with zero, as this could also remove the append flag from the set. bz3523 * ssh(1): avoid printf("%s", NULL) if using UserKnownHostsFile=none and a hostkey in one of the system known hosts file changes. * scp(1): switch scp from using pipes to a socket-pair for communication with its ssh sub-processes, matching how sftp(1) operates. * sshd(8): clear signal mask early in main(); sshd may have been started with one or more signals masked (sigprocmask(2) is not cleared on fork/exec) and this could interfere with various things, e.g. the login grace timer. Execution environments that fail to clear the signal mask before running sshd are clearly broken, but apparently they do exist. * ssh(1): warn if no host keys for hostbased auth can be loaded. * sshd(8): Add server debugging for hostbased auth that is queued and sent to the client after successful authentication, but also logged to assist in diagnosis of HostbasedAuthentication problems. bz3507 * ssh(1): document use of the IdentityFile option as being usable to list public keys as well as private keys. GHPR352 * sshd(8): check for and disallow MaxStartups values less than or equal to zero during config parsing, rather than failing later at runtime. bz3489 * ssh-keygen(1): fix parsing of hex cert expiry times specified on the command-line when acting as a CA. * scp(1): when scp(1) is using the SFTP protocol for transport (the default), better match scp/rcp's handling of globs that don't match the globbed characters but do match literally (e.g. trying to transfer a file named "foo.[1]"). Previously scp(1) in SFTP mode would not match these pathnames but legacy scp/rcp mode would. bz3488 * ssh-agent(1): document the "-O no-restrict-websafe" command-line option. * ssh(1): honour user's umask(2) if it is more restrictive then the ssh default (022). Portability ----------- * sshd(8): allow writev(2) in the Linux seccomp sandbox. This seems to be used by recent glibcs at least in some configurations during error conditions. bz3512. * sshd(8): simply handling of SSH_CONNECTION PAM env var, removing global variable and checking the return value from pam_putenv. bz3508 * sshd(8): disable SANDBOX_SECCOMP_FILTER_DEBUG that was mistakenly enabled during the OpenSSH 9.1 release cycle. * misc: update autotools and regenerate the config files using the latest autotools * all: use -fzero-call-used-regs=used on clang 15 instead of -fzero-call-used-reg=all, as some versions of clang 15 have miscompile code when it was enabled. bz3475 * sshd(8): defer PRNG seeding until after the initial closefrom(2) call. PRNG seeding will initialize OpenSSL, and some engine providers (e.g. Intel's QAT) will open descriptors for their own use that closefrom(2) could clobber. bz3483 * misc: in the poll(2)/ppoll(2) compatibility code, avoid assuming the layout of fd_set. * sftp-server(8), ssh-agent(1): fix ptrace(2) disabling on older FreeBSD kernels. Some versions do not support using id 0 to refer to the current PID for procctl, so try again with getpid() explicitly before failing. * configure.ac: fix -Wstrict-prototypes in configure test code. Clang 16 now warns on this and legacy prototypes will be removed in C23. GHPR355 * configure.ac: fix setres*id checks to work with clang-16. glibc has the prototypes for setresuid behind _GNU_SOURCE, and clang 16 will error out on implicit function definitions. bz3497 Checksums: ========== - SHA1 (openssh-9.2.tar.gz) = e4b806b7c81b87d6c90afe97b3d016ba6cf3ba1c - SHA256 (openssh-9.2.tar.gz) = yYe9uaaWSeetXGXOxuaaEiIsLnvITmGW+l5dgMZb9QU= - SHA1 (openssh-9.2p1.tar.gz) = 3b172b8e971773a7018bbf3231f6589ae539ca4b - SHA256 (openssh-9.2p1.tar.gz) = P2bb8WVftF9Q4cVtpiqwEhjCKIB7ITONY068351xz0Y= Please note that the SHA256 signatures are base64 encoded and not hexadecimal (which is the default for most checksum tools). The PGP key used to sign the releases is available from the mirror sites: https://cdn.openbsd.org/pub/OpenBSD/OpenSSH/RELEASE_KEY.asc Reporting Bugs: =============== - Please read https://www.openssh.com/report.html Security bugs should be reported directly to openssh@openssh.com
2023-07-26 20:31:29 +03:00
M_CP_STRARRAYOPT(channel_timeouts, num_channel_timeouts); \
OpenSSH 8.5/8.5p1 (2021-03-03) OpenSSH 8.5 was released on 2021-03-03. It is available from the mirrors listed at https://www.openssh.com/. OpenSSH is a 100% complete SSH protocol 2.0 implementation and includes sftp client and server support. Once again, we would like to thank the OpenSSH community for their continued support of the project, especially those who contributed code or patches, reported bugs, tested snapshots or donated to the project. More information on donations may be found at: https://www.openssh.com/donations.html Future deprecation notice ========================= It is now possible[1] to perform chosen-prefix attacks against the SHA-1 algorithm for less than USD$50K. In the SSH protocol, the "ssh-rsa" signature scheme uses the SHA-1 hash algorithm in conjunction with the RSA public key algorithm. OpenSSH will disable this signature scheme by default in the near future. Note that the deactivation of "ssh-rsa" signatures does not necessarily require cessation of use for RSA keys. In the SSH protocol, keys may be capable of signing using multiple algorithms. In particular, "ssh-rsa" keys are capable of signing using "rsa-sha2-256" (RSA/SHA256), "rsa-sha2-512" (RSA/SHA512) and "ssh-rsa" (RSA/SHA1). Only the last of these is being turned off by default. This algorithm is unfortunately still used widely despite the existence of better alternatives, being the only remaining public key signature algorithm specified by the original SSH RFCs that is still enabled by default. The better alternatives include: * The RFC8332 RSA SHA-2 signature algorithms rsa-sha2-256/512. These algorithms have the advantage of using the same key type as "ssh-rsa" but use the safe SHA-2 hash algorithms. These have been supported since OpenSSH 7.2 and are already used by default if the client and server support them. * The RFC8709 ssh-ed25519 signature algorithm. It has been supported in OpenSSH since release 6.5. * The RFC5656 ECDSA algorithms: ecdsa-sha2-nistp256/384/521. These have been supported by OpenSSH since release 5.7. To check whether a server is using the weak ssh-rsa public key algorithm, for host authentication, try to connect to it after removing the ssh-rsa algorithm from ssh(1)'s allowed list: ssh -oHostKeyAlgorithms=-ssh-rsa user@host If the host key verification fails and no other supported host key types are available, the server software on that host should be upgraded. This release enables the UpdateHostKeys option by default to assist the client by automatically migrating to better algorithms. [1] "SHA-1 is a Shambles: First Chosen-Prefix Collision on SHA-1 and Application to the PGP Web of Trust" Leurent, G and Peyrin, T (2020) https://eprint.iacr.org/2020/014.pdf Security ======== * ssh-agent(1): fixed a double-free memory corruption that was introduced in OpenSSH 8.2 . We treat all such memory faults as potentially exploitable. This bug could be reached by an attacker with access to the agent socket. On modern operating systems where the OS can provide information about the user identity connected to a socket, OpenSSH ssh-agent and sshd limit agent socket access only to the originating user and root. Additional mitigation may be afforded by the system's malloc(3)/free(3) implementation, if it detects double-free conditions. The most likely scenario for exploitation is a user forwarding an agent either to an account shared with a malicious user or to a host with an attacker holding root access. * Portable sshd(8): Prevent excessively long username going to PAM. This is a mitigation for a buffer overflow in Solaris' PAM username handling (CVE-2020-14871), and is only enabled for Sun-derived PAM implementations. This is not a problem in sshd itself, it only prevents sshd from being used as a vector to attack Solaris' PAM. It does not prevent the bug in PAM from being exploited via some other PAM application. GHPR212 Potentially-incompatible changes ================================ This release includes a number of changes that may affect existing configurations: * ssh(1), sshd(8): this release changes the first-preference signature algorithm from ECDSA to ED25519. * ssh(1), sshd(8): set the TOS/DSCP specified in the configuration for interactive use prior to TCP connect. The connection phase of the SSH session is time-sensitive and often explicitly interactive. The ultimate interactive/bulk TOS/DSCP will be set after authentication completes. * ssh(1), sshd(8): remove the pre-standardization cipher rijndael-cbc@lysator.liu.se. It is an alias for aes256-cbc before it was standardized in RFC4253 (2006), has been deprecated and disabled by default since OpenSSH 7.2 (2016) and was only briefly documented in ssh.1 in 2001. * ssh(1), sshd(8): update/replace the experimental post-quantum hybrid key exchange method based on Streamlined NTRU Prime coupled with X25519. The previous sntrup4591761x25519-sha512@tinyssh.org method is replaced with sntrup761x25519-sha512@openssh.com. Per its designers, the sntrup4591761 algorithm was superseded almost two years ago by sntrup761. (note this both the updated method and the one that it replaced are disabled by default) * ssh(1): disable CheckHostIP by default. It provides insignificant benefits while making key rotation significantly more difficult, especially for hosts behind IP-based load-balancers. Changes since OpenSSH 8.4 ========================= New features ------------ * ssh(1): this release enables UpdateHostkeys by default subject to some conservative preconditions: - The key was matched in the UserKnownHostsFile (and not in the GlobalKnownHostsFile). - The same key does not exist under another name. - A certificate host key is not in use. - known_hosts contains no matching wildcard hostname pattern. - VerifyHostKeyDNS is not enabled. - The default UserKnownHostsFile is in use. We expect some of these conditions will be modified or relaxed in future. * ssh(1), sshd(8): add a new LogVerbose configuration directive for that allows forcing maximum debug logging by file/function/line pattern-lists. * ssh(1): when prompting the user to accept a new hostkey, display any other host names/addresses already associated with the key. * ssh(1): allow UserKnownHostsFile=none to indicate that no known_hosts file should be used to identify host keys. * ssh(1): add a ssh_config KnownHostsCommand option that allows the client to obtain known_hosts data from a command in addition to the usual files. * ssh(1): add a ssh_config PermitRemoteOpen option that allows the client to restrict the destination when RemoteForward is used with SOCKS. * ssh(1): for FIDO keys, if a signature operation fails with a "incorrect PIN" reason and no PIN was initially requested from the user, then request a PIN and retry the operation. This supports some biometric devices that fall back to requiring PIN when reading of the biometric failed, and devices that require PINs for all hosted credentials. * sshd(8): implement client address-based rate-limiting via new sshd_config(5) PerSourceMaxStartups and PerSourceNetBlockSize directives that provide more fine-grained control on a per-origin address basis than the global MaxStartups limit. Bugfixes -------- * ssh(1): Prefix keyboard interactive prompts with "(user@host)" to make it easier to determine which connection they are associated with in cases like scp -3, ProxyJump, etc. bz#3224 * sshd(8): fix sshd_config SetEnv directives located inside Match blocks. GHPR201 * ssh(1): when requesting a FIDO token touch on stderr, inform the user once the touch has been recorded. * ssh(1): prevent integer overflow when ridiculously large ConnectTimeout values are specified, capping the effective value (for most platforms) at 24 days. bz#3229 * ssh(1): consider the ECDSA key subtype when ordering host key algorithms in the client. * ssh(1), sshd(8): rename the PubkeyAcceptedKeyTypes keyword to PubkeyAcceptedAlgorithms. The previous name incorrectly suggested that it control allowed key algorithms, when this option actually specifies the signature algorithms that are accepted. The previous name remains available as an alias. bz#3253 * ssh(1), sshd(8): similarly, rename HostbasedKeyTypes (ssh) and HostbasedAcceptedKeyTypes (sshd) to HostbasedAcceptedAlgorithms. * sftp-server(8): add missing lsetstat@openssh.com documentation and advertisement in the server's SSH2_FXP_VERSION hello packet. * ssh(1), sshd(8): more strictly enforce KEX state-machine by banning packet types once they are received. Fixes memleak caused by duplicate SSH2_MSG_KEX_DH_GEX_REQUEST (oss-fuzz #30078). * sftp(1): allow the full range of UIDs/GIDs for chown/chgrp on 32bit platforms instead of being limited by LONG_MAX. bz#3206 * Minor man page fixes (capitalization, commas, etc.) bz#3223 * sftp(1): when doing an sftp recursive upload or download of a read-only directory, ensure that the directory is created with write and execute permissions in the interim so that the transfer can actually complete, then set the directory permission as the final step. bz#3222 * ssh-keygen(1): document the -Z, check the validity of its argument earlier and provide a better error message if it's not correct. bz#2879 * ssh(1): ignore comments at the end of config lines in ssh_config, similar to what we already do for sshd_config. bz#2320 * sshd_config(5): mention that DisableForwarding is valid in a sshd_config Match block. bz3239 * sftp(1): fix incorrect sorting of "ls -ltr" under some circumstances. bz3248. * ssh(1), sshd(8): fix potential integer truncation of (unlikely) timeout values. bz#3250 * ssh(1): make hostbased authentication send the signature algorithm in its SSH2_MSG_USERAUTH_REQUEST packets instead of the key type. This make HostbasedAcceptedAlgorithms do what it is supposed to - filter on signature algorithm and not key type. Portability ----------- * sshd(8): add a number of platform-specific syscalls to the Linux seccomp-bpf sandbox. bz#3232 bz#3260 * sshd(8): remove debug message from sigchld handler that could cause deadlock on some platforms. bz#3259 * Sync contrib/ssh-copy-id with upstream. * unittests: add a hostname function for systems that don't have it. Some systems don't have a hostname command (it's not required by POSIX). The do have uname -n (which is), but not all of those have it report the FQDN. Checksums: ========== - SHA1 (openssh-8.5.tar.gz) = 04cae43c389fb411227c01219e4eb46e3113f34e - SHA256 (openssh-8.5.tar.gz) = 5qB2CgzNG4io4DmChTjHgCWqRWvEOvCKJskLdJCz+SU= - SHA1 (openssh-8.5p1.tar.gz) = 72eadcbe313b07b1dd3b693e41d3cd56d354e24e - SHA256 (openssh-8.5p1.tar.gz) = 9S8/QdQpqpkY44zyAK8iXM3Y5m8FLaVyhwyJc3ZG7CU= Please note that the SHA256 signatures are base64 encoded and not hexadecimal (which is the default for most checksum tools). The PGP key used to sign the releases is available from the mirror sites: https://cdn.openbsd.org/pub/OpenBSD/OpenSSH/RELEASE_KEY.asc Please note that the OpenPGP key used to sign releases has been rotated for this release. The new key has been signed by the previous key to provide continuity. Reporting Bugs: =============== - Please read https://www.openssh.com/report.html Security bugs should be reported directly to openssh@openssh.com
2021-03-05 20:45:24 +03:00
M_CP_STRARRAYOPT(log_verbose, num_log_verbose); \
Import OpenSSH 9.5 (Last was OpenSSH 9.3) OpenSSH 9.5/9.5p1 (2023-10-04) OpenSSH 9.5 was released on 2023-10-04. It is available from the mirrors listed at https://www.openssh.com/. OpenSSH is a 100% complete SSH protocol 2.0 implementation and includes sftp client and server support. Once again, we would like to thank the OpenSSH community for their continued support of the project, especially those who contributed code or patches, reported bugs, tested snapshots or donated to the project. More information on donations may be found at: https://www.openssh.com/donations.html Changes since OpenSSH 9.4 ========================= This release fixes a number of bugs and adds some small features. Potentially incompatible changes -------------------------------- * ssh-keygen(1): generate Ed25519 keys by default. Ed25519 public keys are very convenient due to their small size. Ed25519 keys are specified in RFC 8709 and OpenSSH has supported them since version 6.5 (January 2014). * sshd(8): the Subsystem directive now accurately preserves quoting of subsystem commands and arguments. This may change behaviour for exotic configurations, but the most common subsystem configuration (sftp-server) is unlikely to be affected. New features ------------ * ssh(1): add keystroke timing obfuscation to the client. This attempts to hide inter-keystroke timings by sending interactive traffic at fixed intervals (default: every 20ms) when there is only a small amount of data being sent. It also sends fake "chaff" keystrokes for a random interval after the last real keystroke. These are controlled by a new ssh_config ObscureKeystrokeTiming keyword. * ssh(1), sshd(8): Introduce a transport-level ping facility. This adds a pair of SSH transport protocol messages SSH2_MSG_PING/PONG to implement a ping capability. These messages use numbers in the "local extensions" number space and are advertised using a "ping@openssh.com" ext-info message with a string version number of "0". * sshd(8): allow override of Subsystem directives in sshd Match blocks. Bugfixes -------- * scp(1): fix scp in SFTP mode recursive upload and download of directories that contain symlinks to other directories. In scp mode, the links would be followed, but in SFTP mode they were not. bz3611 * ssh-keygen(1): handle cr+lf (instead of just cr) line endings in sshsig signature files. * ssh(1): interactive mode for ControlPersist sessions if they originally requested a tty. * sshd(8): make PerSourceMaxStartups first-match-wins * sshd(8): limit artificial login delay to a reasonable maximum (5s) and don't delay at all for the "none" authentication mechanism.cw bz3602 * sshd(8): Log errors in kex_exchange_identification() with level verbose instead of error to reduce preauth log spam. All of those get logged with a more generic error message by sshpkt_fatal(). * sshd(8): correct math for ClientAliveInterval that caused the probes to be sent less frequently than configured. * ssh(1): fix regression in OpenSSH 9.4 (mux.c r1.99) that caused multiplexed sessions to ignore SIGINT under some circumstances. Portability ----------- * Avoid clang zero-call-used-regs=all bug on Apple compilers, which for some reason have version numbers that do not match the upstream clang version numbers. bz#3584 * Fix configure test for zlib 1.3 and later/development versions. bz3604 Checksums: ========== - SHA1 (openssh-9.5.tar.gz) = 8a0bd3a91fac338d97d91817af58df731f6509a3 - SHA256 (openssh-9.5.tar.gz) = sVMxeM3d6g65qBMktJIofxmK4Ipg9dblKif0VnhPeO0= - SHA1 (openssh-9.5p1.tar.gz) = 35c16dcc6e7d0a9465faa241476ef24f76b196cc - SHA256 (openssh-9.5p1.tar.gz) = 8Cbnt5un+1QPdRgq+W3IqPHbOV+SK7yfbKYDZyaGCGs= Please note that the SHA256 signatures are base64 encoded and not hexadecimal (which is the default for most checksum tools). The PGP key used to sign the releases is available from the mirror sites: https://cdn.openbsd.org/pub/OpenBSD/OpenSSH/RELEASE_KEY.asc Reporting Bugs: =============== - Please read https://www.openssh.com/report.html Security bugs should be reported directly to openssh@openssh.com OpenSSH 9.4/9.4p1 (2023-08-10) OpenSSH 9.4 was released on 2023-08-10. It is available from the mirrors listed at https://www.openssh.com/. OpenSSH is a 100% complete SSH protocol 2.0 implementation and includes sftp client and server support. Once again, we would like to thank the OpenSSH community for their continued support of the project, especially those who contributed code or patches, reported bugs, tested snapshots or donated to the project. More information on donations may be found at: https://www.openssh.com/donations.html Changes since OpenSSH 9.3p2 =========================== This release fixes a number of bugs and adds some small features. Potentially incompatible changes -------------------------------- * This release removes support for older versions of libcrypto. OpenSSH now requires LibreSSL >= 3.1.0 or OpenSSL >= 1.1.1. Note that these versions are already deprecated by their upstream vendors. * ssh-agent(1): PKCS#11 modules must now be specified by their full paths. Previously dlopen(3) could search for them in system library directories. New features ------------ * ssh(1): allow forwarding Unix Domain sockets via ssh -W. * ssh(1): add support for configuration tags to ssh(1). This adds a ssh_config(5) "Tag" directive and corresponding "Match tag" predicate that may be used to select blocks of configuration similar to the pf.conf(5) keywords of the same name. * ssh(1): add a "match localnetwork" predicate. This allows matching on the addresses of available network interfaces and may be used to vary the effective client configuration based on network location. * ssh(1), sshd(8), ssh-keygen(1): infrastructure support for KRL extensions. This defines wire formats for optional KRL extensions and implements parsing of the new submessages. No actual extensions are supported at this point. * sshd(8): AuthorizedPrincipalsCommand and AuthorizedKeysCommand now accept two additional %-expansion sequences: %D which expands to the routing domain of the connected session and %C which expands to the addresses and port numbers for the source and destination of the connection. * ssh-keygen(1): increase the default work factor (rounds) for the bcrypt KDF used to derive symmetric encryption keys for passphrase protected key files by 50%. Bugfixes -------- * ssh-agent(1): improve isolation between loaded PKCS#11 modules by running separate ssh-pkcs11-helpers for each loaded provider. * ssh(1): make -f (fork after authentication) work correctly with multiplexed connections, including ControlPersist. bz3589 bz3589 * ssh(1): make ConnectTimeout apply to multiplexing sockets and not just to network connections. * ssh-agent(1), ssh(1): improve defences against invalid PKCS#11 modules being loaded by checking that the requested module contains the required symbol before loading it. * sshd(8): fix AuthorizedPrincipalsCommand when AuthorizedKeysCommand appears before it in sshd_config. Since OpenSSH 8.7 the AuthorizedPrincipalsCommand directive was incorrectly ignored in this situation. bz3574 * sshd(8), ssh(1), ssh-keygen(1): remove vestigal support for KRL signatures When the KRL format was originally defined, it included support for signing of KRL objects. However, the code to sign KRLs and verify KRL signatues was never completed in OpenSSH. This release removes the partially-implemented code to verify KRLs. All OpenSSH tools now ignore KRL_SECTION_SIGNATURE sections in KRL files. * All: fix a number of memory leaks and unreachable/harmless integer overflows. * ssh-agent(1), ssh(1): don't truncate strings logged from PKCS#11 modules; GHPR406 * sshd(8), ssh(1): better validate CASignatureAlgorithms in ssh_config and sshd_config. Previously this directive would accept certificate algorithm names, but these were unusable in practice as OpenSSH does not support CA chains. bz3577 * ssh(1): make `ssh -Q CASignatureAlgorithms` only list signature algorithms that are valid for CA signing. Previous behaviour was to list all signing algorithms, including certificate algorithms. * ssh-keyscan(1): gracefully handle systems where rlimits or the maximum number of open files is larger than INT_MAX; bz3581 * ssh-keygen(1): fix "no comment" not showing on when running `ssh-keygen -l` on multiple keys where one has a comment and other following keys do not. bz3580 * scp(1), sftp(1): adjust ftruncate() logic to handle servers that reorder requests. Previously, if the server reordered requests then the resultant file would be erroneously truncated. * ssh(1): don't incorrectly disable hostname canonicalization when CanonicalizeHostname=yes and ProxyJump was expicitly set to "none". bz3567 * scp(1): when copying local->remote, check that the source file exists before opening an SFTP connection to the server. Based on GHPR#370 Portability ----------- * All: a number of build fixes for various platforms and configuration combinations. * sshd(8): provide a replacement for the SELinux matchpathcon() function, which is deprecated. * All: relax libcrypto version checks for OpenSSL >=3. Beyond OpenSSL 3.0, the ABI compatibility guarantees are wider (only the library major must match instead of major and minor in earlier versions). bz#3548. * Tests: fix build problems for the sk-dummy.so FIDO provider module used in some tests. Checksums: ========== - SHA1 (openssh-9.4.tar.gz) = d88126d8d7b8e5bf4656587ac4a16055560641cc - SHA256 (openssh-9.4.tar.gz) = 7eqFjx2hAunw+1Jy7f1JQXq//3AMr9B3dKtASDtq8go= - SHA1 (openssh-9.4p1.tar.gz) = 5dea1f3c88f9cfe53a711a3c893ee8b7d3ffecff - SHA256 (openssh-9.4p1.tar.gz) = Ngj9kIjbIWPOs+YAyFq3nQ3j0iHlkZLqGSPiMmOGaoU= Please note that the SHA256 signatures are base64 encoded and not hexadecimal (which is the default for most checksum tools). The PGP key used to sign the releases is available from the mirror sites: https://cdn.openbsd.org/pub/OpenBSD/OpenSSH/RELEASE_KEY.asc Reporting Bugs: =============== - Please read https://www.openssh.com/report.html Security bugs should be reported directly to openssh@openssh.com
2023-10-25 23:14:30 +03:00
M_CP_STRARRAYOPT(subsystem_name, num_subsystems); \
M_CP_STRARRAYOPT(subsystem_command, num_subsystems); \
M_CP_STRARRAYOPT(subsystem_args, num_subsystems); \
new openssh: See http://www.openssh.com/txt/release-5.9
2011-09-07 00:16:49 +04:00
} while (0)
Import 8.0: Security ======== This release contains mitigation for a weakness in the scp(1) tool and protocol (CVE-2019-6111): when copying files from a remote system to a local directory, scp(1) did not verify that the filenames that the server sent matched those requested by the client. This could allow a hostile server to create or clobber unexpected local files with attacker-controlled content. This release adds client-side checking that the filenames sent from the server match the command-line request, The scp protocol is outdated, inflexible and not readily fixed. We recommend the use of more modern protocols like sftp and rsync for file transfer instead. Potentially-incompatible changes ================================ This release includes a number of changes that may affect existing configurations: * scp(1): Relating to the above changes to scp(1); the scp protocol relies on the remote shell for wildcard expansion, so there is no infallible way for the client's wildcard matching to perfectly reflect the server's. If there is a difference between client and server wildcard expansion, the client may refuse files from the server. For this reason, we have provided a new "-T" flag to scp that disables these client-side checks at the risk of reintroducing the attack described above. * sshd(8): Remove support for obsolete "host/port" syntax. Slash- separated host/port was added in 2001 as an alternative to host:port syntax for the benefit of IPv6 users. These days there are establised standards for this like [::1]:22 and the slash syntax is easily mistaken for CIDR notation, which OpenSSH supports for some things. Remove the slash notation from ListenAddress and PermitOpen; bz#2335 Changes since OpenSSH 7.9 ========================= This release is focused on new features and internal refactoring. New Features ------------ * ssh(1), ssh-agent(1), ssh-add(1): Add support for ECDSA keys in PKCS#11 tokens. * ssh(1), sshd(8): Add experimental quantum-computing resistant key exchange method, based on a combination of Streamlined NTRU Prime 4591^761 and X25519. * ssh-keygen(1): Increase the default RSA key size to 3072 bits, following NIST Special Publication 800-57's guidance for a 128-bit equivalent symmetric security level. * ssh(1): Allow "PKCS11Provider=none" to override later instances of the PKCS11Provider directive in ssh_config; bz#2974 * sshd(8): Add a log message for situations where a connection is dropped for attempting to run a command but a sshd_config ForceCommand=internal-sftp restriction is in effect; bz#2960 * ssh(1): When prompting whether to record a new host key, accept the key fingerprint as a synonym for "yes". This allows the user to paste a fingerprint obtained out of band at the prompt and have the client do the comparison for you. * ssh-keygen(1): When signing multiple certificates on a single command-line invocation, allow automatically incrementing the certificate serial number. * scp(1), sftp(1): Accept -J option as an alias to ProxyJump on the scp and sftp command-lines. * ssh-agent(1), ssh-pkcs11-helper(8), ssh-add(1): Accept "-v" command-line flags to increase the verbosity of output; pass verbose flags though to subprocesses, such as ssh-pkcs11-helper started from ssh-agent. * ssh-add(1): Add a "-T" option to allowing testing whether keys in an agent are usable by performing a signature and a verification. * sftp-server(8): Add a "lsetstat@openssh.com" protocol extension that replicates the functionality of the existing SSH2_FXP_SETSTAT operation but does not follow symlinks. bz#2067 * sftp(1): Add "-h" flag to chown/chgrp/chmod commands to request they do not follow symlinks. * sshd(8): Expose $SSH_CONNECTION in the PAM environment. This makes the connection 4-tuple available to PAM modules that wish to use it in decision-making. bz#2741 * sshd(8): Add a ssh_config "Match final" predicate Matches in same pass as "Match canonical" but doesn't require hostname canonicalisation be enabled. bz#2906 * sftp(1): Support a prefix of '@' to suppress echo of sftp batch commands; bz#2926 * ssh-keygen(1): When printing certificate contents using "ssh-keygen -Lf /path/certificate", include the algorithm that the CA used to sign the cert. Bugfixes -------- * sshd(8): Fix authentication failures when sshd_config contains "AuthenticationMethods any" inside a Match block that overrides a more restrictive default. * sshd(8): Avoid sending duplicate keepalives when ClientAliveCount is enabled. * sshd(8): Fix two race conditions related to SIGHUP daemon restart. Remnant file descriptors in recently-forked child processes could block the parent sshd's attempt to listen(2) to the configured addresses. Also, the restarting parent sshd could exit before any child processes that were awaiting their re-execution state had completed reading it, leaving them in a fallback path. * ssh(1): Fix stdout potentially being redirected to /dev/null when ProxyCommand=- was in use. * sshd(8): Avoid sending SIGPIPE to child processes if they attempt to write to stderr after their parent processes have exited; bz#2071 * ssh(1): Fix bad interaction between the ssh_config ConnectTimeout and ConnectionAttempts directives - connection attempts after the first were ignoring the requested timeout; bz#2918 * ssh-keyscan(1): Return a non-zero exit status if no keys were found; bz#2903 * scp(1): Sanitize scp filenames to allow UTF-8 characters without terminal control sequences; bz#2434 * sshd(8): Fix confusion between ClientAliveInterval and time-based RekeyLimit that could cause connections to be incorrectly closed. bz#2757 * ssh(1), ssh-add(1): Correct some bugs in PKCS#11 token PIN handling at initial token login. The attempt to read the PIN could be skipped in some cases, particularly on devices with integrated PIN readers. This would lead to an inability to retrieve keys from these tokens. bz#2652 * ssh(1), ssh-add(1): Support keys on PKCS#11 tokens that set the CKA_ALWAYS_AUTHENTICATE flag by requring a fresh login after the C_SignInit operation. bz#2638 * ssh(1): Improve documentation for ProxyJump/-J, clarifying that local configuration does not apply to jump hosts. * ssh-keygen(1): Clarify manual - ssh-keygen -e only writes public keys, not private. * ssh(1), sshd(8): be more strict in processing protocol banners, allowing \r characters only immediately before \n. * Various: fix a number of memory leaks, including bz#2942 and bz#2938 * scp(1), sftp(1): fix calculation of initial bandwidth limits. Account for bytes written before the timer starts and adjust the schedule on which recalculations are performed. Avoids an initial burst of traffic and yields more accurate bandwidth limits; bz#2927 * sshd(8): Only consider the ext-info-c extension during the initial key eschange. It shouldn't be sent in subsequent ones, but if it is present we should ignore it. This prevents sshd from sending a SSH_MSG_EXT_INFO for REKEX for buggy these clients. bz#2929 * ssh-keygen(1): Clarify manual that ssh-keygen -F (find host in authorized_keys) and -R (remove host from authorized_keys) options may accept either a bare hostname or a [hostname]:port combo. bz#2935 * ssh(1): Don't attempt to connect to empty SSH_AUTH_SOCK; bz#2936 * sshd(8): Silence error messages when sshd fails to load some of the default host keys. Failure to load an explicitly-configured hostkey is still an error, and failure to load any host key is still fatal. pr/103 * ssh(1): Redirect stderr of ProxyCommands to /dev/null when ssh is started with ControlPersist; prevents random ProxyCommand output from interfering with session output. * ssh(1): The ssh client was keeping a redundant ssh-agent socket (leftover from authentication) around for the life of the connection; bz#2912 * sshd(8): Fix bug in HostbasedAcceptedKeyTypes and PubkeyAcceptedKeyTypes options. If only RSA-SHA2 siganture types were specified, then authentication would always fail for RSA keys as the monitor checks only the base key (not the signature algorithm) type against *AcceptedKeyTypes. bz#2746 * ssh(1): Request correct signature types from ssh-agent when certificate keys and RSA-SHA2 signatures are in use. Portability ----------- * sshd(8): On Cygwin, run as SYSTEM where possible, using S4U for token creation if it supports MsV1_0 S4U Logon. * sshd(8): On Cygwin, use custom user/group matching code that respects the OS' behaviour of case-insensitive matching. * sshd(8): Don't set $MAIL if UsePAM=yes as PAM typically specifies the user environment if it's enabled; bz#2937 * sshd(8) Cygwin: Change service name to cygsshd to avoid collision with Microsoft's OpenSSH port. * Allow building against OpenSSL -dev (3.x) * Fix a number of build problems against version configurations and versions of OpenSSL. Including bz#2931 and bz#2921 * Improve warnings in cygwin service setup. bz#2922 * Remove hardcoded service name in cygwin setup. bz#2922
2019-04-20 20:13:53 +03:00
struct connection_info *get_connection_info(struct ssh *, int, int);
import 5.2 from ftp.openbsd.org
2009-06-08 02:19:00 +04:00
void initialize_server_options(ServerOptions *);
void fill_default_server_options(ServerOptions *);
int process_server_config_line(ServerOptions *, char *, const char *, int,
Import OpenSSH-8.6: Future deprecation notice ========================= It is now possible[1] to perform chosen-prefix attacks against the SHA-1 algorithm for less than USD$50K. In the SSH protocol, the "ssh-rsa" signature scheme uses the SHA-1 hash algorithm in conjunction with the RSA public key algorithm. OpenSSH will disable this signature scheme by default in the near future. Note that the deactivation of "ssh-rsa" signatures does not necessarily require cessation of use for RSA keys. In the SSH protocol, keys may be capable of signing using multiple algorithms. In particular, "ssh-rsa" keys are capable of signing using "rsa-sha2-256" (RSA/SHA256), "rsa-sha2-512" (RSA/SHA512) and "ssh-rsa" (RSA/SHA1). Only the last of these is being turned off by default. This algorithm is unfortunately still used widely despite the existence of better alternatives, being the only remaining public key signature algorithm specified by the original SSH RFCs that is still enabled by default. The better alternatives include: * The RFC8332 RSA SHA-2 signature algorithms rsa-sha2-256/512. These algorithms have the advantage of using the same key type as "ssh-rsa" but use the safe SHA-2 hash algorithms. These have been supported since OpenSSH 7.2 and are already used by default if the client and server support them. * The RFC8709 ssh-ed25519 signature algorithm. It has been supported in OpenSSH since release 6.5. * The RFC5656 ECDSA algorithms: ecdsa-sha2-nistp256/384/521. These have been supported by OpenSSH since release 5.7. To check whether a server is using the weak ssh-rsa public key algorithm, for host authentication, try to connect to it after removing the ssh-rsa algorithm from ssh(1)'s allowed list: ssh -oHostKeyAlgorithms=-ssh-rsa user@host If the host key verification fails and no other supported host key types are available, the server software on that host should be upgraded. OpenSSH recently enabled the UpdateHostKeys option by default to assist the client by automatically migrating to better algorithms. [1] "SHA-1 is a Shambles: First Chosen-Prefix Collision on SHA-1 and Application to the PGP Web of Trust" Leurent, G and Peyrin, T (2020) https://eprint.iacr.org/2020/014.pdf Security ======== * sshd(8): OpenSSH 8.5 introduced the LogVerbose keyword. When this option was enabled with a set of patterns that activated logging in code that runs in the low-privilege sandboxed sshd process, the log messages were constructed in such a way that printf(3) format strings could effectively be specified the low-privilege code. An attacker who had sucessfully exploited the low-privilege process could use this to escape OpenSSH's sandboxing and attack the high-privilege process. Exploitation of this weakness is highly unlikely in practice as the LogVerbose option is not enabled by default and is typically only used for debugging. No vulnerabilities in the low-privilege process are currently known to exist. Thanks to Ilja Van Sprundel for reporting this bug. Changes since OpenSSH 8.5 ========================= This release contains mostly bug fixes. New features ------------ * sftp-server(8): add a new limits@openssh.com protocol extension that allows a client to discover various server limits, including maximum packet size and maximum read/write length. * sftp(1): use the new limits@openssh.com extension (when available) to select better transfer lengths in the client. * sshd(8): Add ModuliFile keyword to sshd_config to specify the location of the "moduli" file containing the groups for DH-GEX. * unit tests: Add a TEST_SSH_ELAPSED_TIMES environment variable to enable printing of the elapsed time in seconds of each test. Bugfixes -------- * ssh_config(5), sshd_config(5): sync CASignatureAlgorithms lists in manual pages with the current default. GHPR#174 * ssh(1): ensure that pkcs11_del_provider() is called before exit. GHPR#234 * ssh(1), sshd(8): fix problems in string->argv conversion. Multiple backslashes were not being dequoted correctly and quoted space in the middle of a string was being incorrectly split. GHPR#223 * ssh(1): return non-zero exit status when killed by signal; bz#3281 * sftp-server(8): increase maximum SSH2_FXP_READ to match the maximum packet size. Also handle zero-length reads that are not explicitly banned by the spec. Portability ----------- * sshd(8): don't mistakenly exit on transient read errors on the network socket (e.g. EINTR, EAGAIN); bz3297 * Create a dedicated contrib/gnome-ssk-askpass3.c source instead of building it from the same file as used for GNOME2. Use the GNOME3 gdk_seat_grab() to manage keyboard/mouse/server grabs for better compatibility with Wayland. * Fix portability build errors bz3293 bz3292 bz3291 bz3278 * sshd(8): soft-disallow the fstatat64 syscall in the Linux seccomp-bpf sandbox. bz3276 * unit tests: enable autoopt and misc unit tests that were previously skipped
2021-04-19 17:38:27 +03:00
int *, struct connection_info *, struct include_list *includes);
Potentially-incompatible changes ================================ This release includes a number of changes that may affect existing configurations: * ssh(1): delete SSH protocol version 1 support, associated configuration options and documentation. * ssh(1)/sshd(8): remove support for the hmac-ripemd160 MAC. * ssh(1)/sshd(8): remove support for the arcfour, blowfish and CAST ciphers. * Refuse RSA keys <1024 bits in length and improve reporting for keys that do not meet this requirement. * ssh(1): do not offer CBC ciphers by default. Changes since OpenSSH 7.5 ========================= This is primarily a bugfix release. It also contains substantial internal refactoring. Security -------- * sftp-server(8): in read-only mode, sftp-server was incorrectly permitting creation of zero-length files. Reported by Michal Zalewski. New Features ------------ * ssh(1): add RemoteCommand option to specify a command in the ssh config file instead of giving it on the client's command line. This allows the configuration file to specify the command that will be executed on the remote host. * sshd(8): add ExposeAuthInfo option that enables writing details of the authentication methods used (including public keys where applicable) to a file that is exposed via a $SSH_USER_AUTH environment variable in the subsequent session. * ssh(1): add support for reverse dynamic forwarding. In this mode, ssh will act as a SOCKS4/5 proxy and forward connections to destinations requested by the remote SOCKS client. This mode is requested using extended syntax for the -R and RemoteForward options and, because it is implemented solely at the client, does not require the server be updated to be supported. * sshd(8): allow LogLevel directive in sshd_config Match blocks; bz#2717 * ssh-keygen(1): allow inclusion of arbitrary string or flag certificate extensions and critical options. * ssh-keygen(1): allow ssh-keygen to use a key held in ssh-agent as a CA when signing certificates. bz#2377 * ssh(1)/sshd(8): allow IPQoS=none in ssh/sshd to not set an explicit ToS/DSCP value and just use the operating system default. * ssh-add(1): added -q option to make ssh-add quiet on success. * ssh(1): expand the StrictHostKeyChecking option with two new settings. The first "accept-new" will automatically accept hitherto-unseen keys but will refuse connections for changed or invalid hostkeys. This is a safer subset of the current behaviour of StrictHostKeyChecking=no. The second setting "off", is a synonym for the current behaviour of StrictHostKeyChecking=no: accept new host keys, and continue connection for hosts with incorrect hostkeys. A future release will change the meaning of StrictHostKeyChecking=no to the behaviour of "accept-new". bz#2400 * ssh(1): add SyslogFacility option to ssh(1) matching the equivalent option in sshd(8). bz#2705 Bugfixes -------- * ssh(1): use HostKeyAlias if specified instead of hostname for matching host certificate principal names; bz#2728 * sftp(1): implement sorting for globbed ls; bz#2649 * ssh(1): add a user@host prefix to client's "Permission denied" messages, useful in particular when using "stacked" connections (e.g. ssh -J) where it's not clear which host is denying. bz#2720 * ssh(1): accept unknown EXT_INFO extension values that contain \0 characters. These are legal, but would previously cause fatal connection errors if received. * ssh(1)/sshd(8): repair compression statistics printed at connection exit * sftp(1): print '?' instead of incorrect link count (that the protocol doesn't provide) for remote listings. bz#2710 * ssh(1): return failure rather than fatal() for more cases during session multiplexing negotiations. Causes the session to fall back to a non-mux connection if they occur. bz#2707 * ssh(1): mention that the server may send debug messages to explain public key authentication problems under some circumstances; bz#2709 * Translate OpenSSL error codes to better report incorrect passphrase errors when loading private keys; bz#2699 * sshd(8): adjust compatibility patterns for WinSCP to correctly identify versions that implement only the legacy DH group exchange scheme. bz#2748 * ssh(1): print the "Killed by signal 1" message only at LogLevel verbose so that it is not shown at the default level; prevents it from appearing during ssh -J and equivalent ProxyCommand configs. bz#1906, bz#2744 * ssh-keygen(1): when generating all hostkeys (ssh-keygen -A), clobber existing keys if they exist but are zero length. zero-length keys could previously be made if ssh-keygen failed or was interrupted part way through generating them. bz#2561 * ssh(1): fix pledge(2) violation in the escape sequence "~&" used to place the current session in the background. * ssh-keyscan(1): avoid double-close() on file descriptors; bz#2734 * sshd(8): avoid reliance on shared use of pointers shared between monitor and child sshd processes. bz#2704 * sshd_config(8): document available AuthenticationMethods; bz#2453 * ssh(1): avoid truncation in some login prompts; bz#2768 * sshd(8): Fix various compilations failures, inc bz#2767 * ssh(1): make "--" before the hostname terminate argument processing after the hostname too. * ssh-keygen(1): switch from aes256-cbc to aes256-ctr for encrypting new-style private keys. Fixes problems related to private key handling for no-OpenSSL builds. bz#2754 * ssh(1): warn and do not attempt to use keys when the public and private halves do not match. bz#2737 * sftp(1): don't print verbose error message when ssh disconnects from under sftp. bz#2750 * sshd(8): fix keepalive scheduling problem: activity on a forwarded port from preventing the keepalive from being sent; bz#2756 * sshd(8): when started without root privileges, don't require the privilege separation user or path to exist. Makes running the regression tests easier without touching the filesystem. * Make integrity.sh regression tests more robust against timeouts. bz#2658 * ssh(1)/sshd(8): correctness fix for channels implementation: accept channel IDs greater than 0x7FFFFFFF. Portability ----------- * sshd(9): drop two more privileges in the Solaris sandbox: PRIV_DAX_ACCESS and PRIV_SYS_IB_INFO; bz#2723 * sshd(8): expose list of completed authentication methods to PAM via the SSH_AUTH_INFO_0 PAM environment variable. bz#2408 * ssh(1)/sshd(8): fix several problems in the tun/tap forwarding code, mostly to do with host/network byte order confusion. bz#2735 * Add --with-cflags-after and --with-ldflags-after configure flags to allow setting CFLAGS/LDFLAGS after configure has completed. These are useful for setting sanitiser/fuzzing options that may interfere with configure's operation. * sshd(8): avoid Linux seccomp violations on ppc64le over the socketcall syscall. * Fix use of ldns when using ldns-config; bz#2697 * configure: set cache variables when cross-compiling. The cross- compiling fallback message was saying it assumed the test passed, but it wasn't actually set the cache variables and this would cause later tests to fail. * Add clang libFuzzer harnesses for public key parsing and signature verification.
2017-10-07 22:36:11 +03:00
void process_permitopen(struct ssh *ssh, ServerOptions *options);
Import OpenSSH 9.3 + the fix from p2 for the PKCS#11 remote provider The previous version was OpenSSH 9.1 OpenSSH 9.3p2 (2023-07-19) OpenSSH 9.3p2 was released on 2023-07-19. It is available from the mirrors listed at https://www.openssh.com/. OpenSSH is a 100% complete SSH protocol 2.0 implementation and includes sftp client and server support. Once again, we would like to thank the OpenSSH community for their continued support of the project, especially those who contributed code or patches, reported bugs, tested snapshots or donated to the project. More information on donations may be found at: https://www.openssh.com/donations.html Changes since OpenSSH 9.3 ========================= This release fixes a security bug. Security ======== Fix CVE-2023-38408 - a condition where specific libaries loaded via ssh-agent(1)'s PKCS#11 support could be abused to achieve remote code execution via a forwarded agent socket if the following conditions are met: * Exploitation requires the presence of specific libraries on the victim system. * Remote exploitation requires that the agent was forwarded to an attacker-controlled system. Exploitation can also be prevented by starting ssh-agent(1) with an empty PKCS#11/FIDO allowlist (ssh-agent -P '') or by configuring an allowlist that contains only specific provider libraries. This vulnerability was discovered and demonstrated to be exploitable by the Qualys Security Advisory team. In addition to removing the main precondition for exploitation, this release removes the ability for remote ssh-agent(1) clients to load PKCS#11 modules by default (see below). Potentially-incompatible changes -------------------------------- * ssh-agent(8): the agent will now refuse requests to load PKCS#11 modules issued by remote clients by default. A flag has been added to restore the previous behaviour "-Oallow-remote-pkcs11". Note that ssh-agent(8) depends on the SSH client to identify requests that are remote. The OpenSSH >=8.9 ssh(1) client does this, but forwarding access to an agent socket using other tools may circumvent this restriction. Checksums: ========== - SHA1 (openssh-9.3p2.tar.gz) = 219cf700c317f400bb20b001c0406056f7188ea4 - SHA256 (openssh-9.3p2.tar.gz) = IA6+FH9ss/EB/QzfngJEKvfdyimN/9n0VoeOfMrGdug= Please note that the SHA256 signatures are base64 encoded and not hexadecimal (which is the default for most checksum tools). The PGP key used to sign the releases is available from the mirror sites: https://cdn.openbsd.org/pub/OpenBSD/OpenSSH/RELEASE_KEY.asc Reporting Bugs: =============== - Please read https://www.openssh.com/report.html Security bugs should be reported directly to openssh@openssh.com OpenSSH 9.3/9.3p1 (2023-03-15) OpenSSH 9.3 was released on 2023-03-15. It is available from the mirrors listed at https://www.openssh.com/. OpenSSH is a 100% complete SSH protocol 2.0 implementation and includes sftp client and server support. Once again, we would like to thank the OpenSSH community for their continued support of the project, especially those who contributed code or patches, reported bugs, tested snapshots or donated to the project. More information on donations may be found at: https://www.openssh.com/donations.html Changes since OpenSSH 9.2 ========================= This release fixes a number of security bugs. Security ======== This release contains fixes for a security problem and a memory safety problem. The memory safety problem is not believed to be exploitable, but we report most network-reachable memory faults as security bugs. * ssh-add(1): when adding smartcard keys to ssh-agent(1) with the per-hop destination constraints (ssh-add -h ...) added in OpenSSH 8.9, a logic error prevented the constraints from being communicated to the agent. This resulted in the keys being added without constraints. The common cases of non-smartcard keys and keys without destination constraints are unaffected. This problem was reported by Luci Stanescu. * ssh(1): Portable OpenSSH provides an implementation of the getrrsetbyname(3) function if the standard library does not provide it, for use by the VerifyHostKeyDNS feature. A specifically crafted DNS response could cause this function to perform an out-of-bounds read of adjacent stack data, but this condition does not appear to be exploitable beyond denial-of- service to the ssh(1) client. The getrrsetbyname(3) replacement is only included if the system's standard library lacks this function and portable OpenSSH was not compiled with the ldns library (--with-ldns). getrrsetbyname(3) is only invoked if using VerifyHostKeyDNS to fetch SSHFP records. This problem was found by the Coverity static analyzer. New features ------------ * ssh-keygen(1), ssh-keyscan(1): accept -Ohashalg=sha1|sha256 when outputting SSHFP fingerprints to allow algorithm selection. bz3493 * sshd(8): add a `sshd -G` option that parses and prints the effective configuration without attempting to load private keys and perform other checks. This allows usage of the option before keys have been generated and for configuration evaluation and verification by unprivileged users. Bugfixes -------- * scp(1), sftp(1): fix progressmeter corruption on wide displays; bz3534 * ssh-add(1), ssh-keygen(1): use RSA/SHA256 when testing usability of private keys as some systems are starting to disable RSA/SHA1 in libcrypto. * sftp-server(8): fix a memory leak. GHPR363 * ssh(1), sshd(8), ssh-keyscan(1): remove vestigal protocol compatibility code and simplify what's left. * Fix a number of low-impact Coverity static analysis findings. These include several reported via bz2687 * ssh_config(5), sshd_config(5): mention that some options are not first-match-wins. * Rework logging for the regression tests. Regression tests will now capture separate logs for each ssh and sshd invocation in a test. * ssh(1): make `ssh -Q CASignatureAlgorithms` work as the manpage says it should; bz3532. * ssh(1): ensure that there is a terminating newline when adding a new entry to known_hosts; bz3529 Portability ----------- * sshd(8): harden Linux seccomp sandbox. Move to an allowlist of mmap(2), madvise(2) and futex(2) flags, removing some concerning kernel attack surface. * sshd(8): improve Linux seccomp-bpf sandbox for older systems; bz3537 Checksums: ========== - SHA1 (openssh-9.3.tar.gz) = 5f9d2f73ddfe94f3f0a78bdf46704b6ad7b66ec7 - SHA256 (openssh-9.3.tar.gz) = eRcXkFZByz70DUBUcyIdvU0pVxP2X280FrmV8pyUdrk= - SHA1 (openssh-9.3p1.tar.gz) = 610959871bf8d6baafc3525811948f85b5dd84ab - SHA256 (openssh-9.3p1.tar.gz) = 6bq6dwGnalHz2Fpiw4OjydzZf6kAuFm8fbEUwYaK+Kg= Please note that the SHA256 signatures are base64 encoded and not hexadecimal (which is the default for most checksum tools). The PGP key used to sign the releases is available from the mirror sites: https://cdn.openbsd.org/pub/OpenBSD/OpenSSH/RELEASE_KEY.asc Reporting Bugs: =============== - Please read https://www.openssh.com/report.html Security bugs should be reported directly to openssh@openssh.com OpenSSH 9.2/9.2p1 (2023-02-02) OpenSSH 9.2 was released on 2023-02-02. It is available from the mirrors listed at https://www.openssh.com/. OpenSSH is a 100% complete SSH protocol 2.0 implementation and includes sftp client and server support. Once again, we would like to thank the OpenSSH community for their continued support of the project, especially those who contributed code or patches, reported bugs, tested snapshots or donated to the project. More information on donations may be found at: https://www.openssh.com/donations.html Changes since OpenSSH 9.1 ========================= This release fixes a number of security bugs. Security ======== This release contains fixes for two security problems and a memory safety problem. The memory safety problem is not believed to be exploitable, but we report most network-reachable memory faults as security bugs. * sshd(8): fix a pre-authentication double-free memory fault introduced in OpenSSH 9.1. This is not believed to be exploitable, and it occurs in the unprivileged pre-auth process that is subject to chroot(2) and is further sandboxed on most major platforms. * ssh(8): in OpenSSH releases after 8.7, the PermitRemoteOpen option would ignore its first argument unless it was one of the special keywords "any" or "none", causing the permission list to fail open if only one permission was specified. bz3515 * ssh(1): if the CanonicalizeHostname and CanonicalizePermittedCNAMEs options were enabled, and the system/libc resolver did not check that names in DNS responses were valid, then use of these options could allow an attacker with control of DNS to include invalid characters (possibly including wildcards) in names added to known_hosts files when they were updated. These names would still have to match the CanonicalizePermittedCNAMEs allow-list, so practical exploitation appears unlikely. Potentially-incompatible changes -------------------------------- * ssh(1): add a new EnableEscapeCommandline ssh_config(5) option that controls whether the client-side ~C escape sequence that provides a command-line is available. Among other things, the ~C command-line could be used to add additional port-forwards at runtime. This option defaults to "no", disabling the ~C command-line that was previously enabled by default. Turning off the command-line allows platforms that support sandboxing of the ssh(1) client (currently only OpenBSD) to use a stricter default sandbox policy. New features ------------ * sshd(8): add support for channel inactivity timeouts via a new sshd_config(5) ChannelTimeout directive. This allows channels that have not seen traffic in a configurable interval to be automatically closed. Different timeouts may be applied to session, X11, agent and TCP forwarding channels. * sshd(8): add a sshd_config UnusedConnectionTimeout option to terminate client connections that have no open channels for a length of time. This complements the ChannelTimeout option above. * sshd(8): add a -V (version) option to sshd like the ssh client has. * ssh(1): add a "Host" line to the output of ssh -G showing the original hostname argument. bz3343 * scp(1), sftp(1): add a -X option to both scp(1) and sftp(1) to allow control over some SFTP protocol parameters: the copy buffer length and the number of in-flight requests, both of which are used during upload/download. Previously these could be controlled in sftp(1) only. This makes them available in both SFTP protocol clients using the same option character sequence. * ssh-keyscan(1): allow scanning of complete CIDR address ranges, e.g. "ssh-keyscan 192.168.0.0/24". If a CIDR range is passed, then it will be expanded to all possible addresses in the range including the all-0s and all-1s addresses. bz#976 * ssh(1): support dynamic remote port forwarding in escape command-line's -R processing. bz#3499 Bugfixes -------- * ssh(1): when restoring non-blocking mode to stdio fds, restore exactly the flags that ssh started with and don't just clobber them with zero, as this could also remove the append flag from the set. bz3523 * ssh(1): avoid printf("%s", NULL) if using UserKnownHostsFile=none and a hostkey in one of the system known hosts file changes. * scp(1): switch scp from using pipes to a socket-pair for communication with its ssh sub-processes, matching how sftp(1) operates. * sshd(8): clear signal mask early in main(); sshd may have been started with one or more signals masked (sigprocmask(2) is not cleared on fork/exec) and this could interfere with various things, e.g. the login grace timer. Execution environments that fail to clear the signal mask before running sshd are clearly broken, but apparently they do exist. * ssh(1): warn if no host keys for hostbased auth can be loaded. * sshd(8): Add server debugging for hostbased auth that is queued and sent to the client after successful authentication, but also logged to assist in diagnosis of HostbasedAuthentication problems. bz3507 * ssh(1): document use of the IdentityFile option as being usable to list public keys as well as private keys. GHPR352 * sshd(8): check for and disallow MaxStartups values less than or equal to zero during config parsing, rather than failing later at runtime. bz3489 * ssh-keygen(1): fix parsing of hex cert expiry times specified on the command-line when acting as a CA. * scp(1): when scp(1) is using the SFTP protocol for transport (the default), better match scp/rcp's handling of globs that don't match the globbed characters but do match literally (e.g. trying to transfer a file named "foo.[1]"). Previously scp(1) in SFTP mode would not match these pathnames but legacy scp/rcp mode would. bz3488 * ssh-agent(1): document the "-O no-restrict-websafe" command-line option. * ssh(1): honour user's umask(2) if it is more restrictive then the ssh default (022). Portability ----------- * sshd(8): allow writev(2) in the Linux seccomp sandbox. This seems to be used by recent glibcs at least in some configurations during error conditions. bz3512. * sshd(8): simply handling of SSH_CONNECTION PAM env var, removing global variable and checking the return value from pam_putenv. bz3508 * sshd(8): disable SANDBOX_SECCOMP_FILTER_DEBUG that was mistakenly enabled during the OpenSSH 9.1 release cycle. * misc: update autotools and regenerate the config files using the latest autotools * all: use -fzero-call-used-regs=used on clang 15 instead of -fzero-call-used-reg=all, as some versions of clang 15 have miscompile code when it was enabled. bz3475 * sshd(8): defer PRNG seeding until after the initial closefrom(2) call. PRNG seeding will initialize OpenSSL, and some engine providers (e.g. Intel's QAT) will open descriptors for their own use that closefrom(2) could clobber. bz3483 * misc: in the poll(2)/ppoll(2) compatibility code, avoid assuming the layout of fd_set. * sftp-server(8), ssh-agent(1): fix ptrace(2) disabling on older FreeBSD kernels. Some versions do not support using id 0 to refer to the current PID for procctl, so try again with getpid() explicitly before failing. * configure.ac: fix -Wstrict-prototypes in configure test code. Clang 16 now warns on this and legacy prototypes will be removed in C23. GHPR355 * configure.ac: fix setres*id checks to work with clang-16. glibc has the prototypes for setresuid behind _GNU_SOURCE, and clang 16 will error out on implicit function definitions. bz3497 Checksums: ========== - SHA1 (openssh-9.2.tar.gz) = e4b806b7c81b87d6c90afe97b3d016ba6cf3ba1c - SHA256 (openssh-9.2.tar.gz) = yYe9uaaWSeetXGXOxuaaEiIsLnvITmGW+l5dgMZb9QU= - SHA1 (openssh-9.2p1.tar.gz) = 3b172b8e971773a7018bbf3231f6589ae539ca4b - SHA256 (openssh-9.2p1.tar.gz) = P2bb8WVftF9Q4cVtpiqwEhjCKIB7ITONY068351xz0Y= Please note that the SHA256 signatures are base64 encoded and not hexadecimal (which is the default for most checksum tools). The PGP key used to sign the releases is available from the mirror sites: https://cdn.openbsd.org/pub/OpenBSD/OpenSSH/RELEASE_KEY.asc Reporting Bugs: =============== - Please read https://www.openssh.com/report.html Security bugs should be reported directly to openssh@openssh.com
2023-07-26 20:31:29 +03:00
void process_channel_timeouts(struct ssh *ssh, ServerOptions *);
Potentially-incompatible changes ================================ This release includes a number of changes that may affect existing configurations: * ssh-keygen(1): write OpenSSH format private keys by default instead of using OpenSSL's PEM format. The OpenSSH format, supported in OpenSSH releases since 2014 and described in the PROTOCOL.key file in the source distribution, offers substantially better protection against offline password guessing and supports key comments in private keys. If necessary, it is possible to write old PEM-style keys by adding "-m PEM" to ssh-keygen's arguments when generating or updating a key. * sshd(8): remove internal support for S/Key multiple factor authentication. S/Key may still be used via PAM or BSD auth. * ssh(1): remove vestigal support for running ssh(1) as setuid. This used to be required for hostbased authentication and the (long gone) rhosts-style authentication, but has not been necessary for a long time. Attempting to execute ssh as a setuid binary, or with uid != effective uid will now yield a fatal error at runtime. * sshd(8): the semantics of PubkeyAcceptedKeyTypes and the similar HostbasedAcceptedKeyTypes options have changed. These now specify signature algorithms that are accepted for their respective authentication mechanism, where previously they specified accepted key types. This distinction matters when using the RSA/SHA2 signature algorithms "rsa-sha2-256", "rsa-sha2-512" and their certificate counterparts. Configurations that override these options but omit these algorithm names may cause unexpected authentication failures (no action is required for configurations that accept the default for these options). * sshd(8): the precedence of session environment variables has changed. ~/.ssh/environment and environment="..." options in authorized_keys files can no longer override SSH_* variables set implicitly by sshd. * ssh(1)/sshd(8): the default IPQoS used by ssh/sshd has changed. They will now use DSCP AF21 for interactive traffic and CS1 for bulk. For a detailed rationale, please see the commit message: https://cvsweb.openbsd.org/src/usr.bin/ssh/readconf.c#rev1.284
2018-08-26 10:39:56 +03:00
void load_server_config(const char *, struct sshbuf *);
void parse_server_config(ServerOptions *, const char *, struct sshbuf *,
Import OpenSSH-9.0 Changes since OpenSSH 8.9 ========================= This release is focused on bug fixing. Potentially-incompatible changes -------------------------------- This release switches scp(1) from using the legacy scp/rcp protocol to using the SFTP protocol by default. Legacy scp/rcp performs wildcard expansion of remote filenames (e.g. "scp host:* .") through the remote shell. This has the side effect of requiring double quoting of shell meta-characters in file names included on scp(1) command-lines, otherwise they could be interpreted as shell commands on the remote side. This creates one area of potential incompatibility: scp(1) when using the SFTP protocol no longer requires this finicky and brittle quoting, and attempts to use it may cause transfers to fail. We consider the removal of the need for double-quoting shell characters in file names to be a benefit and do not intend to introduce bug-compatibility for legacy scp/rcp in scp(1) when using the SFTP protocol. Another area of potential incompatibility relates to the use of remote paths relative to other user's home directories, for example - "scp host:~user/file /tmp". The SFTP protocol has no native way to expand a ~user path. However, sftp-server(8) in OpenSSH 8.7 and later support a protocol extension "expand-path@openssh.com" to support this. In case of incompatibility, the scp(1) client may be instructed to use the legacy scp/rcp using the -O flag. New features ------------ * ssh(1), sshd(8): use the hybrid Streamlined NTRU Prime + x25519 key exchange method by default ("sntrup761x25519-sha512@openssh.com"). The NTRU algorithm is believed to resist attacks enabled by future quantum computers and is paired with the X25519 ECDH key exchange (the previous default) as a backstop against any weaknesses in NTRU Prime that may be discovered in the future. The combination ensures that the hybrid exchange offers at least as good security as the status quo. We are making this change now (i.e. ahead of cryptographically- relevant quantum computers) to prevent "capture now, decrypt later" attacks where an adversary who can record and store SSH session ciphertext would be able to decrypt it once a sufficiently advanced quantum computer is available. * sftp-server(8): support the "copy-data" extension to allow server- side copying of files/data, following the design in draft-ietf-secsh-filexfer-extensions-00. bz2948 * sftp(1): add a "cp" command to allow the sftp client to perform server-side file copies. Bugfixes -------- * ssh(1), sshd(8): upstream: fix poll(2) spin when a channel's output fd closes without data in the channel buffer. bz3405 and bz3411 * sshd(8): pack pollfd array in server listen/accept loop. Could cause the server to hang/spin when MaxStartups > RLIMIT_NOFILE * ssh-keygen(1): avoid NULL deref via the find-principals and check-novalidate operations. bz3409 and GHPR307 respectively. * scp(1): fix a memory leak in argument processing. bz3404 * sshd(8): don't try to resolve ListenAddress directives in the sshd re-exec path. They are unused after re-exec and parsing errors (possible for example if the host's network configuration changed) could prevent connections from being accepted. * sshd(8): when refusing a public key authentication request from a client for using an unapproved or unsupported signature algorithm include the algorithm name in the log message to make debugging easier. Portability ----------- * sshd(8): refactor platform-specific locked account check, fixing an incorrect free() on platforms with both libiaf and shadow passwords (probably only Unixware) GHPR284, * ssh(1), sshd(8): Fix possible integer underflow in scan_scaled(3) parsing of K/M/G/etc quantities. bz#3401. * sshd(8): provide killpg implementation (mostly for Tandem NonStop) GHPR301. * Check for missing ftruncate prototype. GHPR301 * sshd(8): default to not using sandbox when cross compiling. On most systems poll(2) does not work when the number of FDs is reduced with setrlimit, so assume it doesn't when cross compiling and we can't run the test. bz#3398. * sshd(8): allow ppoll_time64 in seccomp sandbox. Should fix sandbox violations on some (at least i386 and armhf) 32bit Linux platforms. bz#3396. * Improve detection of -fzero-call-used-regs=all support in configure script.
2022-04-15 16:58:16 +03:00
struct include_list *includes, struct connection_info *, int);
OpenSSH 8.2/8.2p1 (2020-02-14) OpenSSH 8.2 was released on 2020-02-14. It is available from the mirrors listed at https://www.openssh.com/. OpenSSH is a 100% complete SSH protocol 2.0 implementation and includes sftp client and server support. Once again, we would like to thank the OpenSSH community for their continued support of the project, especially those who contributed code or patches, reported bugs, tested snapshots or donated to the project. More information on donations may be found at: https://www.openssh.com/donations.html Future deprecation notice ========================= It is now possible[1] to perform chosen-prefix attacks against the SHA-1 hash algorithm for less than USD$50K. For this reason, we will be disabling the "ssh-rsa" public key signature algorithm that depends on SHA-1 by default in a near-future release. This algorithm is unfortunately still used widely despite the existence of better alternatives, being the only remaining public key signature algorithm specified by the original SSH RFCs. The better alternatives include: * The RFC8332 RSA SHA-2 signature algorithms rsa-sha2-256/512. These algorithms have the advantage of using the same key type as "ssh-rsa" but use the safe SHA-2 hash algorithms. These have been supported since OpenSSH 7.2 and are already used by default if the client and server support them. * The ssh-ed25519 signature algorithm. It has been supported in OpenSSH since release 6.5. * The RFC5656 ECDSA algorithms: ecdsa-sha2-nistp256/384/521. These have been supported by OpenSSH since release 5.7. To check whether a server is using the weak ssh-rsa public key algorithm for host authentication, try to connect to it after removing the ssh-rsa algorithm from ssh(1)'s allowed list: ssh -oHostKeyAlgorithms=-ssh-rsa user@host If the host key verification fails and no other supported host key types are available, the server software on that host should be upgraded. A future release of OpenSSH will enable UpdateHostKeys by default to allow the client to automatically migrate to better algorithms. Users may consider enabling this option manually. [1] "SHA-1 is a Shambles: First Chosen-Prefix Collision on SHA-1 and Application to the PGP Web of Trust" Leurent, G and Peyrin, T (2020) https://eprint.iacr.org/2020/014.pdf Security ======== * ssh(1), sshd(8), ssh-keygen(1): this release removes the "ssh-rsa" (RSA/SHA1) algorithm from those accepted for certificate signatures (i.e. the client and server CASignatureAlgorithms option) and will use the rsa-sha2-512 signature algorithm by default when the ssh-keygen(1) CA signs new certificates. Certificates are at special risk to the aforementioned SHA1 collision vulnerability as an attacker has effectively unlimited time in which to craft a collision that yields them a valid certificate, far more than the relatively brief LoginGraceTime window that they have to forge a host key signature. The OpenSSH certificate format includes a CA-specified (typically random) nonce value near the start of the certificate that should make exploitation of chosen-prefix collisions in this context challenging, as the attacker does not have full control over the prefix that actually gets signed. Nonetheless, SHA1 is now a demonstrably broken algorithm and futher improvements in attacks are highly likely. OpenSSH releases prior to 7.2 do not support the newer RSA/SHA2 algorithms and will refuse to accept certificates signed by an OpenSSH 8.2+ CA using RSA keys unless the unsafe algorithm is explicitly selected during signing ("ssh-keygen -t ssh-rsa"). Older clients/servers may use another CA key type such as ssh-ed25519 (supported since OpenSSH 6.5) or one of the ecdsa-sha2-nistp256/384/521 types (supported since OpenSSH 5.7) instead if they cannot be upgraded. Potentially-incompatible changes ================================ This release includes a number of changes that may affect existing configurations: * ssh(1), sshd(8): the above removal of "ssh-rsa" from the accepted CASignatureAlgorithms list. * ssh(1), sshd(8): this release removes diffie-hellman-group14-sha1 from the default key exchange proposal for both the client and server. * ssh-keygen(1): the command-line options related to the generation and screening of safe prime numbers used by the diffie-hellman-group-exchange-* key exchange algorithms have changed. Most options have been folded under the -O flag. * sshd(8): the sshd listener process title visible to ps(1) has changed to include information about the number of connections that are currently attempting authentication and the limits configured by MaxStartups. * ssh-sk-helper(8): this is a new binary. It is used by the FIDO/U2F support to provide address-space isolation for token middleware libraries (including the internal one). It needs to be installed in the expected path, typically under /usr/libexec or similar. Changes since OpenSSH 8.1 ========================= This release contains some significant new features. FIDO/U2F Support ---------------- This release adds support for FIDO/U2F hardware authenticators to OpenSSH. U2F/FIDO are open standards for inexpensive two-factor authentication hardware that are widely used for website authentication. In OpenSSH FIDO devices are supported by new public key types "ecdsa-sk" and "ed25519-sk", along with corresponding certificate types. ssh-keygen(1) may be used to generate a FIDO token-backed key, after which they may be used much like any other key type supported by OpenSSH, so long as the hardware token is attached when the keys are used. FIDO tokens also generally require the user explicitly authorise operations by touching or tapping them. Generating a FIDO key requires the token be attached, and will usually require the user tap the token to confirm the operation: $ ssh-keygen -t ecdsa-sk -f ~/.ssh/id_ecdsa_sk Generating public/private ecdsa-sk key pair. You may need to touch your security key to authorize key generation. Enter file in which to save the key (/home/djm/.ssh/id_ecdsa_sk): Enter passphrase (empty for no passphrase): Enter same passphrase again: Your identification has been saved in /home/djm/.ssh/id_ecdsa_sk Your public key has been saved in /home/djm/.ssh/id_ecdsa_sk.pub This will yield a public and private key-pair. The private key file should be useless to an attacker who does not have access to the physical token. After generation, this key may be used like any other supported key in OpenSSH and may be listed in authorized_keys, added to ssh-agent(1), etc. The only additional stipulation is that the FIDO token that the key belongs to must be attached when the key is used. FIDO tokens are most commonly connected via USB but may be attached via other means such as Bluetooth or NFC. In OpenSSH, communication with the token is managed via a middleware library, specified by the SecurityKeyProvider directive in ssh/sshd_config(5) or the $SSH_SK_PROVIDER environment variable for ssh-keygen(1) and ssh-add(1). The API for this middleware is documented in the sk-api.h and PROTOCOL.u2f files in the source distribution. OpenSSH includes a middleware ("SecurityKeyProvider=internal") with support for USB tokens. It is automatically enabled in OpenBSD and may be enabled in portable OpenSSH via the configure flag --with-security-key-builtin. If the internal middleware is enabled then it is automatically used by default. This internal middleware requires that libfido2 (https://github.com/Yubico/libfido2) and its dependencies be installed. We recommend that packagers of portable OpenSSH enable the built-in middleware, as it provides the lowest-friction experience for users. Note: FIDO/U2F tokens are required to implement the ECDSA-P256 "ecdsa-sk" key type, but hardware support for Ed25519 "ed25519-sk" is less common. Similarly, not all hardware tokens support some of the optional features such as resident keys. The protocol-level changes to support FIDO/U2F keys in SSH are documented in the PROTOCOL.u2f file in the OpenSSH source distribution. There are a number of supporting changes to this feature: * ssh-keygen(1): add a "no-touch-required" option when generating FIDO-hosted keys, that disables their default behaviour of requiring a physical touch/tap on the token during authentication. Note: not all tokens support disabling the touch requirement. * sshd(8): add a sshd_config PubkeyAuthOptions directive that collects miscellaneous public key authentication-related options for sshd(8). At present it supports only a single option "no-touch-required". This causes sshd to skip its default check for FIDO/U2F keys that the signature was authorised by a touch or press event on the token hardware. * ssh(1), sshd(8), ssh-keygen(1): add a "no-touch-required" option for authorized_keys and a similar extension for certificates. This option disables the default requirement that FIDO key signatures attest that the user touched their key to authorize them, mirroring the similar PubkeyAuthOptions sshd_config option. * ssh-keygen(1): add support for the writing the FIDO attestation information that is returned when new keys are generated via the "-O write-attestation=/path" option. FIDO attestation certificates may be used to verify that a FIDO key is hosted in trusted hardware. OpenSSH does not currently make use of this information, beyond optionally writing it to disk. FIDO2 resident keys ------------------- FIDO/U2F OpenSSH keys consist of two parts: a "key handle" part stored in the private key file on disk, and a per-device private key that is unique to each FIDO/U2F token and that cannot be exported from the token hardware. These are combined by the hardware at authentication time to derive the real key that is used to sign authentication challenges. For tokens that are required to move between computers, it can be cumbersome to have to move the private key file first. To avoid this requirement, tokens implementing the newer FIDO2 standard support "resident keys", where it is possible to effectively retrieve the key handle part of the key from the hardware. OpenSSH supports this feature, allowing resident keys to be generated using the ssh-keygen(1) "-O resident" flag. This will produce a public/private key pair as usual, but it will be possible to retrieve the private key part from the token later. This may be done using "ssh-keygen -K", which will download all available resident keys from the tokens attached to the host and write public/private key files for them. It is also possible to download and add resident keys directly to ssh-agent(1) without writing files to the file-system using "ssh-add -K". Resident keys are indexed on the token by the application string and user ID. By default, OpenSSH uses an application string of "ssh:" and an empty user ID. If multiple resident keys on a single token are desired then it may be necessary to override one or both of these defaults using the ssh-keygen(1) "-O application=" or "-O user=" options. Note: OpenSSH will only download and use resident keys whose application string begins with "ssh:" Storing both parts of a key on a FIDO token increases the likelihood of an attacker being able to use a stolen token device. For this reason, tokens should enforce PIN authentication before allowing download of keys, and users should set a PIN on their tokens before creating any resident keys. Other New Features ------------------ * sshd(8): add an Include sshd_config keyword that allows including additional configuration files via glob(3) patterns. bz2468 * ssh(1)/sshd(8): make the LE (low effort) DSCP code point available via the IPQoS directive; bz2986, * ssh(1): when AddKeysToAgent=yes is set and the key contains no comment, add the key to the agent with the key's path as the comment. bz2564 * ssh-keygen(1), ssh-agent(1): expose PKCS#11 key labels and X.509 subjects as key comments, rather than simply listing the PKCS#11 provider library path. PR138 * ssh-keygen(1): allow PEM export of DSA and ECDSA keys; bz3091 * ssh(1), sshd(8): make zlib compile-time optional, available via the Makefile.inc ZLIB flag on OpenBSD or via the --with-zlib configure option for OpenSSH portable. * sshd(8): when clients get denied by MaxStartups, send a notification prior to the SSH2 protocol banner according to RFC4253 section 4.2. * ssh(1), ssh-agent(1): when invoking the $SSH_ASKPASS prompt program, pass a hint to the program to describe the type of desired prompt. The possible values are "confirm" (indicating that a yes/no confirmation dialog with no text entry should be shown), "none" (to indicate an informational message only), or blank for the original ssh-askpass behaviour of requesting a password/phrase. * ssh(1): allow forwarding a different agent socket to the path specified by $SSH_AUTH_SOCK, by extending the existing ForwardAgent option to accepting an explicit path or the name of an environment variable in addition to yes/no. * ssh-keygen(1): add a new signature operations "find-principals" to look up the principal associated with a signature from an allowed- signers file. * sshd(8): expose the number of currently-authenticating connections along with the MaxStartups limit in the process title visible to "ps". Bugfixes -------- * sshd(8): make ClientAliveCountMax=0 have sensible semantics: it will now disable connection killing entirely rather than the current behaviour of instantly killing the connection after the first liveness test regardless of success. bz2627 * sshd(8): clarify order of AllowUsers / DenyUsers vs AllowGroups / DenyGroups in the sshd(8) manual page. bz1690 * sshd(8): better describe HashKnownHosts in the manual page. bz2560 * sshd(8): clarify that that permitopen=/PermitOpen do no name or address translation in the manual page. bz3099 * sshd(8): allow the UpdateHostKeys feature to function when multiple known_hosts files are in use. When updating host keys, ssh will now search subsequent known_hosts files, but will add updated host keys to the first specified file only. bz2738 * All: replace all calls to signal(2) with a wrapper around sigaction(2). This wrapper blocks all other signals during the handler preventing races between handlers, and sets SA_RESTART which should reduce the potential for short read/write operations. * sftp(1): fix a race condition in the SIGCHILD handler that could turn in to a kill(-1); bz3084 * sshd(8): fix a case where valid (but extremely large) SSH channel IDs were being incorrectly rejected. bz3098 * ssh(1): when checking host key fingerprints as answers to new hostkey prompts, ignore whitespace surrounding the fingerprint itself. * All: wait for file descriptors to be readable or writeable during non-blocking connect, not just readable. Prevents a timeout when the server doesn't immediately send a banner (e.g. multiplexers like sslh) * sshd_config(5): document the sntrup4591761x25519-sha512@tinyssh.org key exchange algorithm. PR#151
2020-02-27 03:21:35 +03:00
void parse_server_match_config(ServerOptions *,
Import OpenSSH-8.6: Future deprecation notice ========================= It is now possible[1] to perform chosen-prefix attacks against the SHA-1 algorithm for less than USD$50K. In the SSH protocol, the "ssh-rsa" signature scheme uses the SHA-1 hash algorithm in conjunction with the RSA public key algorithm. OpenSSH will disable this signature scheme by default in the near future. Note that the deactivation of "ssh-rsa" signatures does not necessarily require cessation of use for RSA keys. In the SSH protocol, keys may be capable of signing using multiple algorithms. In particular, "ssh-rsa" keys are capable of signing using "rsa-sha2-256" (RSA/SHA256), "rsa-sha2-512" (RSA/SHA512) and "ssh-rsa" (RSA/SHA1). Only the last of these is being turned off by default. This algorithm is unfortunately still used widely despite the existence of better alternatives, being the only remaining public key signature algorithm specified by the original SSH RFCs that is still enabled by default. The better alternatives include: * The RFC8332 RSA SHA-2 signature algorithms rsa-sha2-256/512. These algorithms have the advantage of using the same key type as "ssh-rsa" but use the safe SHA-2 hash algorithms. These have been supported since OpenSSH 7.2 and are already used by default if the client and server support them. * The RFC8709 ssh-ed25519 signature algorithm. It has been supported in OpenSSH since release 6.5. * The RFC5656 ECDSA algorithms: ecdsa-sha2-nistp256/384/521. These have been supported by OpenSSH since release 5.7. To check whether a server is using the weak ssh-rsa public key algorithm, for host authentication, try to connect to it after removing the ssh-rsa algorithm from ssh(1)'s allowed list: ssh -oHostKeyAlgorithms=-ssh-rsa user@host If the host key verification fails and no other supported host key types are available, the server software on that host should be upgraded. OpenSSH recently enabled the UpdateHostKeys option by default to assist the client by automatically migrating to better algorithms. [1] "SHA-1 is a Shambles: First Chosen-Prefix Collision on SHA-1 and Application to the PGP Web of Trust" Leurent, G and Peyrin, T (2020) https://eprint.iacr.org/2020/014.pdf Security ======== * sshd(8): OpenSSH 8.5 introduced the LogVerbose keyword. When this option was enabled with a set of patterns that activated logging in code that runs in the low-privilege sandboxed sshd process, the log messages were constructed in such a way that printf(3) format strings could effectively be specified the low-privilege code. An attacker who had sucessfully exploited the low-privilege process could use this to escape OpenSSH's sandboxing and attack the high-privilege process. Exploitation of this weakness is highly unlikely in practice as the LogVerbose option is not enabled by default and is typically only used for debugging. No vulnerabilities in the low-privilege process are currently known to exist. Thanks to Ilja Van Sprundel for reporting this bug. Changes since OpenSSH 8.5 ========================= This release contains mostly bug fixes. New features ------------ * sftp-server(8): add a new limits@openssh.com protocol extension that allows a client to discover various server limits, including maximum packet size and maximum read/write length. * sftp(1): use the new limits@openssh.com extension (when available) to select better transfer lengths in the client. * sshd(8): Add ModuliFile keyword to sshd_config to specify the location of the "moduli" file containing the groups for DH-GEX. * unit tests: Add a TEST_SSH_ELAPSED_TIMES environment variable to enable printing of the elapsed time in seconds of each test. Bugfixes -------- * ssh_config(5), sshd_config(5): sync CASignatureAlgorithms lists in manual pages with the current default. GHPR#174 * ssh(1): ensure that pkcs11_del_provider() is called before exit. GHPR#234 * ssh(1), sshd(8): fix problems in string->argv conversion. Multiple backslashes were not being dequoted correctly and quoted space in the middle of a string was being incorrectly split. GHPR#223 * ssh(1): return non-zero exit status when killed by signal; bz#3281 * sftp-server(8): increase maximum SSH2_FXP_READ to match the maximum packet size. Also handle zero-length reads that are not explicitly banned by the spec. Portability ----------- * sshd(8): don't mistakenly exit on transient read errors on the network socket (e.g. EINTR, EAGAIN); bz3297 * Create a dedicated contrib/gnome-ssk-askpass3.c source instead of building it from the same file as used for GNOME2. Use the GNOME3 gdk_seat_grab() to manage keyboard/mouse/server grabs for better compatibility with Wayland. * Fix portability build errors bz3293 bz3292 bz3291 bz3278 * sshd(8): soft-disallow the fstatat64 syscall in the Linux seccomp-bpf sandbox. bz3276 * unit tests: enable autoopt and misc unit tests that were previously skipped
2021-04-19 17:38:27 +03:00
struct include_list *includes, struct connection_info *);
From ftp.openbsd.org
2012-12-12 20:52:18 +04:00
int parse_server_match_testspec(struct connection_info *, char *);
int server_match_spec_complete(struct connection_info *);
Import OpenSSH 9.5 (Last was OpenSSH 9.3) OpenSSH 9.5/9.5p1 (2023-10-04) OpenSSH 9.5 was released on 2023-10-04. It is available from the mirrors listed at https://www.openssh.com/. OpenSSH is a 100% complete SSH protocol 2.0 implementation and includes sftp client and server support. Once again, we would like to thank the OpenSSH community for their continued support of the project, especially those who contributed code or patches, reported bugs, tested snapshots or donated to the project. More information on donations may be found at: https://www.openssh.com/donations.html Changes since OpenSSH 9.4 ========================= This release fixes a number of bugs and adds some small features. Potentially incompatible changes -------------------------------- * ssh-keygen(1): generate Ed25519 keys by default. Ed25519 public keys are very convenient due to their small size. Ed25519 keys are specified in RFC 8709 and OpenSSH has supported them since version 6.5 (January 2014). * sshd(8): the Subsystem directive now accurately preserves quoting of subsystem commands and arguments. This may change behaviour for exotic configurations, but the most common subsystem configuration (sftp-server) is unlikely to be affected. New features ------------ * ssh(1): add keystroke timing obfuscation to the client. This attempts to hide inter-keystroke timings by sending interactive traffic at fixed intervals (default: every 20ms) when there is only a small amount of data being sent. It also sends fake "chaff" keystrokes for a random interval after the last real keystroke. These are controlled by a new ssh_config ObscureKeystrokeTiming keyword. * ssh(1), sshd(8): Introduce a transport-level ping facility. This adds a pair of SSH transport protocol messages SSH2_MSG_PING/PONG to implement a ping capability. These messages use numbers in the "local extensions" number space and are advertised using a "ping@openssh.com" ext-info message with a string version number of "0". * sshd(8): allow override of Subsystem directives in sshd Match blocks. Bugfixes -------- * scp(1): fix scp in SFTP mode recursive upload and download of directories that contain symlinks to other directories. In scp mode, the links would be followed, but in SFTP mode they were not. bz3611 * ssh-keygen(1): handle cr+lf (instead of just cr) line endings in sshsig signature files. * ssh(1): interactive mode for ControlPersist sessions if they originally requested a tty. * sshd(8): make PerSourceMaxStartups first-match-wins * sshd(8): limit artificial login delay to a reasonable maximum (5s) and don't delay at all for the "none" authentication mechanism.cw bz3602 * sshd(8): Log errors in kex_exchange_identification() with level verbose instead of error to reduce preauth log spam. All of those get logged with a more generic error message by sshpkt_fatal(). * sshd(8): correct math for ClientAliveInterval that caused the probes to be sent less frequently than configured. * ssh(1): fix regression in OpenSSH 9.4 (mux.c r1.99) that caused multiplexed sessions to ignore SIGINT under some circumstances. Portability ----------- * Avoid clang zero-call-used-regs=all bug on Apple compilers, which for some reason have version numbers that do not match the upstream clang version numbers. bz#3584 * Fix configure test for zlib 1.3 and later/development versions. bz3604 Checksums: ========== - SHA1 (openssh-9.5.tar.gz) = 8a0bd3a91fac338d97d91817af58df731f6509a3 - SHA256 (openssh-9.5.tar.gz) = sVMxeM3d6g65qBMktJIofxmK4Ipg9dblKif0VnhPeO0= - SHA1 (openssh-9.5p1.tar.gz) = 35c16dcc6e7d0a9465faa241476ef24f76b196cc - SHA256 (openssh-9.5p1.tar.gz) = 8Cbnt5un+1QPdRgq+W3IqPHbOV+SK7yfbKYDZyaGCGs= Please note that the SHA256 signatures are base64 encoded and not hexadecimal (which is the default for most checksum tools). The PGP key used to sign the releases is available from the mirror sites: https://cdn.openbsd.org/pub/OpenBSD/OpenSSH/RELEASE_KEY.asc Reporting Bugs: =============== - Please read https://www.openssh.com/report.html Security bugs should be reported directly to openssh@openssh.com OpenSSH 9.4/9.4p1 (2023-08-10) OpenSSH 9.4 was released on 2023-08-10. It is available from the mirrors listed at https://www.openssh.com/. OpenSSH is a 100% complete SSH protocol 2.0 implementation and includes sftp client and server support. Once again, we would like to thank the OpenSSH community for their continued support of the project, especially those who contributed code or patches, reported bugs, tested snapshots or donated to the project. More information on donations may be found at: https://www.openssh.com/donations.html Changes since OpenSSH 9.3p2 =========================== This release fixes a number of bugs and adds some small features. Potentially incompatible changes -------------------------------- * This release removes support for older versions of libcrypto. OpenSSH now requires LibreSSL >= 3.1.0 or OpenSSL >= 1.1.1. Note that these versions are already deprecated by their upstream vendors. * ssh-agent(1): PKCS#11 modules must now be specified by their full paths. Previously dlopen(3) could search for them in system library directories. New features ------------ * ssh(1): allow forwarding Unix Domain sockets via ssh -W. * ssh(1): add support for configuration tags to ssh(1). This adds a ssh_config(5) "Tag" directive and corresponding "Match tag" predicate that may be used to select blocks of configuration similar to the pf.conf(5) keywords of the same name. * ssh(1): add a "match localnetwork" predicate. This allows matching on the addresses of available network interfaces and may be used to vary the effective client configuration based on network location. * ssh(1), sshd(8), ssh-keygen(1): infrastructure support for KRL extensions. This defines wire formats for optional KRL extensions and implements parsing of the new submessages. No actual extensions are supported at this point. * sshd(8): AuthorizedPrincipalsCommand and AuthorizedKeysCommand now accept two additional %-expansion sequences: %D which expands to the routing domain of the connected session and %C which expands to the addresses and port numbers for the source and destination of the connection. * ssh-keygen(1): increase the default work factor (rounds) for the bcrypt KDF used to derive symmetric encryption keys for passphrase protected key files by 50%. Bugfixes -------- * ssh-agent(1): improve isolation between loaded PKCS#11 modules by running separate ssh-pkcs11-helpers for each loaded provider. * ssh(1): make -f (fork after authentication) work correctly with multiplexed connections, including ControlPersist. bz3589 bz3589 * ssh(1): make ConnectTimeout apply to multiplexing sockets and not just to network connections. * ssh-agent(1), ssh(1): improve defences against invalid PKCS#11 modules being loaded by checking that the requested module contains the required symbol before loading it. * sshd(8): fix AuthorizedPrincipalsCommand when AuthorizedKeysCommand appears before it in sshd_config. Since OpenSSH 8.7 the AuthorizedPrincipalsCommand directive was incorrectly ignored in this situation. bz3574 * sshd(8), ssh(1), ssh-keygen(1): remove vestigal support for KRL signatures When the KRL format was originally defined, it included support for signing of KRL objects. However, the code to sign KRLs and verify KRL signatues was never completed in OpenSSH. This release removes the partially-implemented code to verify KRLs. All OpenSSH tools now ignore KRL_SECTION_SIGNATURE sections in KRL files. * All: fix a number of memory leaks and unreachable/harmless integer overflows. * ssh-agent(1), ssh(1): don't truncate strings logged from PKCS#11 modules; GHPR406 * sshd(8), ssh(1): better validate CASignatureAlgorithms in ssh_config and sshd_config. Previously this directive would accept certificate algorithm names, but these were unusable in practice as OpenSSH does not support CA chains. bz3577 * ssh(1): make `ssh -Q CASignatureAlgorithms` only list signature algorithms that are valid for CA signing. Previous behaviour was to list all signing algorithms, including certificate algorithms. * ssh-keyscan(1): gracefully handle systems where rlimits or the maximum number of open files is larger than INT_MAX; bz3581 * ssh-keygen(1): fix "no comment" not showing on when running `ssh-keygen -l` on multiple keys where one has a comment and other following keys do not. bz3580 * scp(1), sftp(1): adjust ftruncate() logic to handle servers that reorder requests. Previously, if the server reordered requests then the resultant file would be erroneously truncated. * ssh(1): don't incorrectly disable hostname canonicalization when CanonicalizeHostname=yes and ProxyJump was expicitly set to "none". bz3567 * scp(1): when copying local->remote, check that the source file exists before opening an SFTP connection to the server. Based on GHPR#370 Portability ----------- * All: a number of build fixes for various platforms and configuration combinations. * sshd(8): provide a replacement for the SELinux matchpathcon() function, which is deprecated. * All: relax libcrypto version checks for OpenSSL >=3. Beyond OpenSSL 3.0, the ABI compatibility guarantees are wider (only the library major must match instead of major and minor in earlier versions). bz#3548. * Tests: fix build problems for the sk-dummy.so FIDO provider module used in some tests. Checksums: ========== - SHA1 (openssh-9.4.tar.gz) = d88126d8d7b8e5bf4656587ac4a16055560641cc - SHA256 (openssh-9.4.tar.gz) = 7eqFjx2hAunw+1Jy7f1JQXq//3AMr9B3dKtASDtq8go= - SHA1 (openssh-9.4p1.tar.gz) = 5dea1f3c88f9cfe53a711a3c893ee8b7d3ffecff - SHA256 (openssh-9.4p1.tar.gz) = Ngj9kIjbIWPOs+YAyFq3nQ3j0iHlkZLqGSPiMmOGaoU= Please note that the SHA256 signatures are base64 encoded and not hexadecimal (which is the default for most checksum tools). The PGP key used to sign the releases is available from the mirror sites: https://cdn.openbsd.org/pub/OpenBSD/OpenSSH/RELEASE_KEY.asc Reporting Bugs: =============== - Please read https://www.openssh.com/report.html Security bugs should be reported directly to openssh@openssh.com
2023-10-25 23:14:30 +03:00
void servconf_merge_subsystems(ServerOptions *, ServerOptions *);
import 5.2 from ftp.openbsd.org
2009-06-08 02:19:00 +04:00
void copy_set_server_options(ServerOptions *, ServerOptions *, int);
void dump_config(ServerOptions *);
Imported openssh-5.6
2010-11-21 20:05:36 +03:00
char *derelativise_path(const char *);
OpenSSH 7.7 was released on 2018-04-02. It is available from the mirrors listed at http://www.openssh.com/ shortly. OpenSSH is a 100% complete SSH protocol 2.0 implementation and includes sftp client and server support. Once again, we would like to thank the OpenSSH community for their continued support of the project, especially those who contributed code or patches, reported bugs, tested snapshots or donated to the project. More information on donations may be found at: http://www.openssh.com/donations.html Potentially-incompatible changes ================================ This release includes a number of changes that may affect existing configurations: * ssh(1)/sshd(8): Drop compatibility support for some very old SSH implementations, including ssh.com <=2.* and OpenSSH <= 3.*. These versions were all released in or before 2001 and predate the final SSH RFCs. The support in question isn't necessary for RFC-compliant SSH implementations. Changes since OpenSSH 7.6 ========================= This is primarily a bugfix release. New Features ------------ * All: Add experimental support for PQC XMSS keys (Extended Hash- Based Signatures) based on the algorithm described in https://tools.ietf.org/html/draft-irtf-cfrg-xmss-hash-based-signatures-12 The XMSS signature code is experimental and not compiled in by default. * sshd(8): Add a "rdomain" criteria for the sshd_config Match keyword to allow conditional configuration that depends on which routing domain a connection was received on (currently supported on OpenBSD and Linux). * sshd_config(5): Add an optional rdomain qualifier to the ListenAddress directive to allow listening on different routing domains. This is supported only on OpenBSD and Linux at present. * sshd_config(5): Add RDomain directive to allow the authenticated session to be placed in an explicit routing domain. This is only supported on OpenBSD at present. * sshd(8): Add "expiry-time" option for authorized_keys files to allow for expiring keys. * ssh(1): Add a BindInterface option to allow binding the outgoing connection to an interface's address (basically a more usable BindAddress) * ssh(1): Expose device allocated for tun/tap forwarding via a new %T expansion for LocalCommand. This allows LocalCommand to be used to prepare the interface. * sshd(8): Expose the device allocated for tun/tap forwarding via a new SSH_TUNNEL environment variable. This allows automatic setup of the interface and surrounding network configuration automatically on the server. * ssh(1)/scp(1)/sftp(1): Add URI support to ssh, sftp and scp, e.g. ssh://user@host or sftp://user@host/path. Additional connection parameters described in draft-ietf-secsh-scp-sftp-ssh-uri-04 are not implemented since the ssh fingerprint format in the draft uses the deprecated MD5 hash with no way to specify the any other algorithm. * ssh-keygen(1): Allow certificate validity intervals that specify only a start or stop time (instead of both or neither). * sftp(1): Allow "cd" and "lcd" commands with no explicit path argument. lcd will change to the local user's home directory as usual. cd will change to the starting directory for session (because the protocol offers no way to obtain the remote user's home directory). bz#2760 * sshd(8): When doing a config test with sshd -T, only require the attributes that are actually used in Match criteria rather than (an incomplete list of) all criteria. Bugfixes -------- * ssh(1)/sshd(8): More strictly check signature types during key exchange against what was negotiated. Prevents downgrade of RSA signatures made with SHA-256/512 to SHA-1. * sshd(8): Fix support for client that advertise a protocol version of "1.99" (indicating that they are prepared to accept both SSHv1 and SSHv2). This was broken in OpenSSH 7.6 during the removal of SSHv1 support. bz#2810 * ssh(1): Warn when the agent returns a ssh-rsa (SHA1) signature when a rsa-sha2-256/512 signature was requested. This condition is possible when an old or non-OpenSSH agent is in use. bz#2799 * ssh-agent(1): Fix regression introduced in 7.6 that caused ssh-agent to fatally exit if presented an invalid signature request message. * sshd_config(5): Accept yes/no flag options case-insensitively, as has been the case in ssh_config(5) for a long time. bz#2664 * ssh(1): Improve error reporting for failures during connection. Under some circumstances misleading errors were being shown. bz#2814 * ssh-keyscan(1): Add -D option to allow printing of results directly in SSHFP format. bz#2821 * regress tests: fix PuTTY interop test broken in last release's SSHv1 removal. bz#2823 * ssh(1): Compatibility fix for some servers that erroneously drop the connection when the IUTF8 (RFC8160) option is sent. * scp(1): Disable RemoteCommand and RequestTTY in the ssh session started by scp (sftp was already doing this.) * ssh-keygen(1): Refuse to create a certificate with an unusable number of principals. * ssh-keygen(1): Fatally exit if ssh-keygen is unable to write all the public key during key generation. Previously it would silently ignore errors writing the comment and terminating newline. * ssh(1): Do not modify hostname arguments that are addresses by automatically forcing them to lower-case. Instead canonicalise them to resolve ambiguities (e.g. ::0001 => ::1) before they are matched against known_hosts. bz#2763 * ssh(1): Don't accept junk after "yes" or "no" responses to hostkey prompts. bz#2803 * sftp(1): Have sftp print a warning about shell cleanliness when decoding the first packet fails, which is usually caused by shells polluting stdout of non-interactive startups. bz#2800 * ssh(1)/sshd(8): Switch timers in packet code from using wall-clock time to monotonic time, allowing the packet layer to better function over a clock step and avoiding possible integer overflows during steps. * Numerous manual page fixes and improvements. Portability ----------- * sshd(8): Correctly detect MIPS ABI in use at configure time. Fixes sandbox violations on some environments. * sshd(8): Remove UNICOS support. The hardware and software are literal museum pieces and support in sshd is too intrusive to justify maintaining. * All: Build and link with "retpoline" flags when available to mitigate the "branch target injection" style (variant 2) of the Spectre branch-prediction vulnerability. * All: Add auto-generated dependency information to Makefile. * Numerous fixed to the RPM spec files. Checksums: ========== - SHA1 (openssh-7.7.tar.gz) = 24812e05fa233014c847c7775748316e7f8a836c - SHA256 (openssh-7.7.tar.gz) = T4ua1L/vgAYqwB0muRahvnm5ZUr3PLY9nPljaG8egvo= - SHA1 (openssh-7.7p1.tar.gz) = 446fe9ed171f289f0d62197dffdbfdaaf21c49f2 - SHA256 (openssh-7.7p1.tar.gz) = 1zvn5oTpnvzQJL4Vowv/y+QbASsvezyQhK7WIXdea48= Please note that the SHA256 signatures are base64 encoded and not hexadecimal (which is the default for most checksum tools). The PGP key used to sign the releases is available as RELEASE_KEY.asc from the mirror sites. Reporting Bugs: =============== - Please read http://www.openssh.com/report.html Security bugs should be reported directly to openssh@openssh.com
2018-04-06 21:56:05 +03:00
void servconf_add_hostkey(const char *, const int,
Import 8.0: Security ======== This release contains mitigation for a weakness in the scp(1) tool and protocol (CVE-2019-6111): when copying files from a remote system to a local directory, scp(1) did not verify that the filenames that the server sent matched those requested by the client. This could allow a hostile server to create or clobber unexpected local files with attacker-controlled content. This release adds client-side checking that the filenames sent from the server match the command-line request, The scp protocol is outdated, inflexible and not readily fixed. We recommend the use of more modern protocols like sftp and rsync for file transfer instead. Potentially-incompatible changes ================================ This release includes a number of changes that may affect existing configurations: * scp(1): Relating to the above changes to scp(1); the scp protocol relies on the remote shell for wildcard expansion, so there is no infallible way for the client's wildcard matching to perfectly reflect the server's. If there is a difference between client and server wildcard expansion, the client may refuse files from the server. For this reason, we have provided a new "-T" flag to scp that disables these client-side checks at the risk of reintroducing the attack described above. * sshd(8): Remove support for obsolete "host/port" syntax. Slash- separated host/port was added in 2001 as an alternative to host:port syntax for the benefit of IPv6 users. These days there are establised standards for this like [::1]:22 and the slash syntax is easily mistaken for CIDR notation, which OpenSSH supports for some things. Remove the slash notation from ListenAddress and PermitOpen; bz#2335 Changes since OpenSSH 7.9 ========================= This release is focused on new features and internal refactoring. New Features ------------ * ssh(1), ssh-agent(1), ssh-add(1): Add support for ECDSA keys in PKCS#11 tokens. * ssh(1), sshd(8): Add experimental quantum-computing resistant key exchange method, based on a combination of Streamlined NTRU Prime 4591^761 and X25519. * ssh-keygen(1): Increase the default RSA key size to 3072 bits, following NIST Special Publication 800-57's guidance for a 128-bit equivalent symmetric security level. * ssh(1): Allow "PKCS11Provider=none" to override later instances of the PKCS11Provider directive in ssh_config; bz#2974 * sshd(8): Add a log message for situations where a connection is dropped for attempting to run a command but a sshd_config ForceCommand=internal-sftp restriction is in effect; bz#2960 * ssh(1): When prompting whether to record a new host key, accept the key fingerprint as a synonym for "yes". This allows the user to paste a fingerprint obtained out of band at the prompt and have the client do the comparison for you. * ssh-keygen(1): When signing multiple certificates on a single command-line invocation, allow automatically incrementing the certificate serial number. * scp(1), sftp(1): Accept -J option as an alias to ProxyJump on the scp and sftp command-lines. * ssh-agent(1), ssh-pkcs11-helper(8), ssh-add(1): Accept "-v" command-line flags to increase the verbosity of output; pass verbose flags though to subprocesses, such as ssh-pkcs11-helper started from ssh-agent. * ssh-add(1): Add a "-T" option to allowing testing whether keys in an agent are usable by performing a signature and a verification. * sftp-server(8): Add a "lsetstat@openssh.com" protocol extension that replicates the functionality of the existing SSH2_FXP_SETSTAT operation but does not follow symlinks. bz#2067 * sftp(1): Add "-h" flag to chown/chgrp/chmod commands to request they do not follow symlinks. * sshd(8): Expose $SSH_CONNECTION in the PAM environment. This makes the connection 4-tuple available to PAM modules that wish to use it in decision-making. bz#2741 * sshd(8): Add a ssh_config "Match final" predicate Matches in same pass as "Match canonical" but doesn't require hostname canonicalisation be enabled. bz#2906 * sftp(1): Support a prefix of '@' to suppress echo of sftp batch commands; bz#2926 * ssh-keygen(1): When printing certificate contents using "ssh-keygen -Lf /path/certificate", include the algorithm that the CA used to sign the cert. Bugfixes -------- * sshd(8): Fix authentication failures when sshd_config contains "AuthenticationMethods any" inside a Match block that overrides a more restrictive default. * sshd(8): Avoid sending duplicate keepalives when ClientAliveCount is enabled. * sshd(8): Fix two race conditions related to SIGHUP daemon restart. Remnant file descriptors in recently-forked child processes could block the parent sshd's attempt to listen(2) to the configured addresses. Also, the restarting parent sshd could exit before any child processes that were awaiting their re-execution state had completed reading it, leaving them in a fallback path. * ssh(1): Fix stdout potentially being redirected to /dev/null when ProxyCommand=- was in use. * sshd(8): Avoid sending SIGPIPE to child processes if they attempt to write to stderr after their parent processes have exited; bz#2071 * ssh(1): Fix bad interaction between the ssh_config ConnectTimeout and ConnectionAttempts directives - connection attempts after the first were ignoring the requested timeout; bz#2918 * ssh-keyscan(1): Return a non-zero exit status if no keys were found; bz#2903 * scp(1): Sanitize scp filenames to allow UTF-8 characters without terminal control sequences; bz#2434 * sshd(8): Fix confusion between ClientAliveInterval and time-based RekeyLimit that could cause connections to be incorrectly closed. bz#2757 * ssh(1), ssh-add(1): Correct some bugs in PKCS#11 token PIN handling at initial token login. The attempt to read the PIN could be skipped in some cases, particularly on devices with integrated PIN readers. This would lead to an inability to retrieve keys from these tokens. bz#2652 * ssh(1), ssh-add(1): Support keys on PKCS#11 tokens that set the CKA_ALWAYS_AUTHENTICATE flag by requring a fresh login after the C_SignInit operation. bz#2638 * ssh(1): Improve documentation for ProxyJump/-J, clarifying that local configuration does not apply to jump hosts. * ssh-keygen(1): Clarify manual - ssh-keygen -e only writes public keys, not private. * ssh(1), sshd(8): be more strict in processing protocol banners, allowing \r characters only immediately before \n. * Various: fix a number of memory leaks, including bz#2942 and bz#2938 * scp(1), sftp(1): fix calculation of initial bandwidth limits. Account for bytes written before the timer starts and adjust the schedule on which recalculations are performed. Avoids an initial burst of traffic and yields more accurate bandwidth limits; bz#2927 * sshd(8): Only consider the ext-info-c extension during the initial key eschange. It shouldn't be sent in subsequent ones, but if it is present we should ignore it. This prevents sshd from sending a SSH_MSG_EXT_INFO for REKEX for buggy these clients. bz#2929 * ssh-keygen(1): Clarify manual that ssh-keygen -F (find host in authorized_keys) and -R (remove host from authorized_keys) options may accept either a bare hostname or a [hostname]:port combo. bz#2935 * ssh(1): Don't attempt to connect to empty SSH_AUTH_SOCK; bz#2936 * sshd(8): Silence error messages when sshd fails to load some of the default host keys. Failure to load an explicitly-configured hostkey is still an error, and failure to load any host key is still fatal. pr/103 * ssh(1): Redirect stderr of ProxyCommands to /dev/null when ssh is started with ControlPersist; prevents random ProxyCommand output from interfering with session output. * ssh(1): The ssh client was keeping a redundant ssh-agent socket (leftover from authentication) around for the life of the connection; bz#2912 * sshd(8): Fix bug in HostbasedAcceptedKeyTypes and PubkeyAcceptedKeyTypes options. If only RSA-SHA2 siganture types were specified, then authentication would always fail for RSA keys as the monitor checks only the base key (not the signature algorithm) type against *AcceptedKeyTypes. bz#2746 * ssh(1): Request correct signature types from ssh-agent when certificate keys and RSA-SHA2 signatures are in use. Portability ----------- * sshd(8): On Cygwin, run as SYSTEM where possible, using S4U for token creation if it supports MsV1_0 S4U Logon. * sshd(8): On Cygwin, use custom user/group matching code that respects the OS' behaviour of case-insensitive matching. * sshd(8): Don't set $MAIL if UsePAM=yes as PAM typically specifies the user environment if it's enabled; bz#2937 * sshd(8) Cygwin: Change service name to cygsshd to avoid collision with Microsoft's OpenSSH port. * Allow building against OpenSSL -dev (3.x) * Fix a number of build problems against version configurations and versions of OpenSSL. Including bz#2931 and bz#2921 * Improve warnings in cygwin service setup. bz#2922 * Remove hardcoded service name in cygwin setup. bz#2922
2019-04-20 20:13:53 +03:00
ServerOptions *, const char *path, int);
OpenSSH 7.7 was released on 2018-04-02. It is available from the mirrors listed at http://www.openssh.com/ shortly. OpenSSH is a 100% complete SSH protocol 2.0 implementation and includes sftp client and server support. Once again, we would like to thank the OpenSSH community for their continued support of the project, especially those who contributed code or patches, reported bugs, tested snapshots or donated to the project. More information on donations may be found at: http://www.openssh.com/donations.html Potentially-incompatible changes ================================ This release includes a number of changes that may affect existing configurations: * ssh(1)/sshd(8): Drop compatibility support for some very old SSH implementations, including ssh.com <=2.* and OpenSSH <= 3.*. These versions were all released in or before 2001 and predate the final SSH RFCs. The support in question isn't necessary for RFC-compliant SSH implementations. Changes since OpenSSH 7.6 ========================= This is primarily a bugfix release. New Features ------------ * All: Add experimental support for PQC XMSS keys (Extended Hash- Based Signatures) based on the algorithm described in https://tools.ietf.org/html/draft-irtf-cfrg-xmss-hash-based-signatures-12 The XMSS signature code is experimental and not compiled in by default. * sshd(8): Add a "rdomain" criteria for the sshd_config Match keyword to allow conditional configuration that depends on which routing domain a connection was received on (currently supported on OpenBSD and Linux). * sshd_config(5): Add an optional rdomain qualifier to the ListenAddress directive to allow listening on different routing domains. This is supported only on OpenBSD and Linux at present. * sshd_config(5): Add RDomain directive to allow the authenticated session to be placed in an explicit routing domain. This is only supported on OpenBSD at present. * sshd(8): Add "expiry-time" option for authorized_keys files to allow for expiring keys. * ssh(1): Add a BindInterface option to allow binding the outgoing connection to an interface's address (basically a more usable BindAddress) * ssh(1): Expose device allocated for tun/tap forwarding via a new %T expansion for LocalCommand. This allows LocalCommand to be used to prepare the interface. * sshd(8): Expose the device allocated for tun/tap forwarding via a new SSH_TUNNEL environment variable. This allows automatic setup of the interface and surrounding network configuration automatically on the server. * ssh(1)/scp(1)/sftp(1): Add URI support to ssh, sftp and scp, e.g. ssh://user@host or sftp://user@host/path. Additional connection parameters described in draft-ietf-secsh-scp-sftp-ssh-uri-04 are not implemented since the ssh fingerprint format in the draft uses the deprecated MD5 hash with no way to specify the any other algorithm. * ssh-keygen(1): Allow certificate validity intervals that specify only a start or stop time (instead of both or neither). * sftp(1): Allow "cd" and "lcd" commands with no explicit path argument. lcd will change to the local user's home directory as usual. cd will change to the starting directory for session (because the protocol offers no way to obtain the remote user's home directory). bz#2760 * sshd(8): When doing a config test with sshd -T, only require the attributes that are actually used in Match criteria rather than (an incomplete list of) all criteria. Bugfixes -------- * ssh(1)/sshd(8): More strictly check signature types during key exchange against what was negotiated. Prevents downgrade of RSA signatures made with SHA-256/512 to SHA-1. * sshd(8): Fix support for client that advertise a protocol version of "1.99" (indicating that they are prepared to accept both SSHv1 and SSHv2). This was broken in OpenSSH 7.6 during the removal of SSHv1 support. bz#2810 * ssh(1): Warn when the agent returns a ssh-rsa (SHA1) signature when a rsa-sha2-256/512 signature was requested. This condition is possible when an old or non-OpenSSH agent is in use. bz#2799 * ssh-agent(1): Fix regression introduced in 7.6 that caused ssh-agent to fatally exit if presented an invalid signature request message. * sshd_config(5): Accept yes/no flag options case-insensitively, as has been the case in ssh_config(5) for a long time. bz#2664 * ssh(1): Improve error reporting for failures during connection. Under some circumstances misleading errors were being shown. bz#2814 * ssh-keyscan(1): Add -D option to allow printing of results directly in SSHFP format. bz#2821 * regress tests: fix PuTTY interop test broken in last release's SSHv1 removal. bz#2823 * ssh(1): Compatibility fix for some servers that erroneously drop the connection when the IUTF8 (RFC8160) option is sent. * scp(1): Disable RemoteCommand and RequestTTY in the ssh session started by scp (sftp was already doing this.) * ssh-keygen(1): Refuse to create a certificate with an unusable number of principals. * ssh-keygen(1): Fatally exit if ssh-keygen is unable to write all the public key during key generation. Previously it would silently ignore errors writing the comment and terminating newline. * ssh(1): Do not modify hostname arguments that are addresses by automatically forcing them to lower-case. Instead canonicalise them to resolve ambiguities (e.g. ::0001 => ::1) before they are matched against known_hosts. bz#2763 * ssh(1): Don't accept junk after "yes" or "no" responses to hostkey prompts. bz#2803 * sftp(1): Have sftp print a warning about shell cleanliness when decoding the first packet fails, which is usually caused by shells polluting stdout of non-interactive startups. bz#2800 * ssh(1)/sshd(8): Switch timers in packet code from using wall-clock time to monotonic time, allowing the packet layer to better function over a clock step and avoiding possible integer overflows during steps. * Numerous manual page fixes and improvements. Portability ----------- * sshd(8): Correctly detect MIPS ABI in use at configure time. Fixes sandbox violations on some environments. * sshd(8): Remove UNICOS support. The hardware and software are literal museum pieces and support in sshd is too intrusive to justify maintaining. * All: Build and link with "retpoline" flags when available to mitigate the "branch target injection" style (variant 2) of the Spectre branch-prediction vulnerability. * All: Add auto-generated dependency information to Makefile. * Numerous fixed to the RPM spec files. Checksums: ========== - SHA1 (openssh-7.7.tar.gz) = 24812e05fa233014c847c7775748316e7f8a836c - SHA256 (openssh-7.7.tar.gz) = T4ua1L/vgAYqwB0muRahvnm5ZUr3PLY9nPljaG8egvo= - SHA1 (openssh-7.7p1.tar.gz) = 446fe9ed171f289f0d62197dffdbfdaaf21c49f2 - SHA256 (openssh-7.7p1.tar.gz) = 1zvn5oTpnvzQJL4Vowv/y+QbASsvezyQhK7WIXdea48= Please note that the SHA256 signatures are base64 encoded and not hexadecimal (which is the default for most checksum tools). The PGP key used to sign the releases is available as RELEASE_KEY.asc from the mirror sites. Reporting Bugs: =============== - Please read http://www.openssh.com/report.html Security bugs should be reported directly to openssh@openssh.com
2018-04-06 21:56:05 +03:00
void servconf_add_hostcert(const char *, const int,
ServerOptions *, const char *path);
import 5.2 from ftp.openbsd.org
2009-06-08 02:19:00 +04:00
#endif /* SERVCONF_H */