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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
/* $OpenBSD: crypto_api.h,v 1.8 2023/01/15 23:05:32 djm Exp $ */
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
/*
* Assembled from generated headers and source files by Markus Friedl.
* Placed in the public domain.
*/
#ifndef crypto_api_h
#define crypto_api_h
#include <stdint.h>
#include <stdlib.h>
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
typedef int8_t crypto_int8;
typedef uint8_t crypto_uint8;
typedef int16_t crypto_int16;
typedef uint16_t crypto_uint16;
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
typedef int32_t crypto_int32;
typedef uint32_t crypto_uint32;
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
typedef int64_t crypto_int64;
typedef uint64_t crypto_uint64;
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
#define randombytes(buf, buf_len) arc4random_buf((buf), (buf_len))
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
#define small_random32() arc4random()
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
#define crypto_hash_sha512_BYTES 64U
int crypto_hash_sha512(unsigned char *, const unsigned char *,
unsigned long long);
#define crypto_sign_ed25519_SECRETKEYBYTES 64U
#define crypto_sign_ed25519_PUBLICKEYBYTES 32U
#define crypto_sign_ed25519_BYTES 64U
int crypto_sign_ed25519(unsigned char *, unsigned long long *,
const unsigned char *, unsigned long long, const unsigned char *);
int crypto_sign_ed25519_open(unsigned char *, unsigned long long *,
const unsigned char *, unsigned long long, const unsigned char *);
int crypto_sign_ed25519_keypair(unsigned char *, unsigned char *);
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
#define crypto_kem_sntrup761_PUBLICKEYBYTES 1158
#define crypto_kem_sntrup761_SECRETKEYBYTES 1763
#define crypto_kem_sntrup761_CIPHERTEXTBYTES 1039
#define crypto_kem_sntrup761_BYTES 32
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
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 crypto_kem_sntrup761_enc(unsigned char *cstr, unsigned char *k,
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
const unsigned char *pk);
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 crypto_kem_sntrup761_dec(unsigned char *k,
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
const unsigned char *cstr, const unsigned char *sk);
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 crypto_kem_sntrup761_keypair(unsigned char *pk, unsigned char *sk);
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
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
#endif /* crypto_api_h */