mirrors listed at http://www.openssh.com/ shortly.
OpenSSH is a 100% complete SSH protocol 2.0 implementation and
includes sftp client and server support.
Once again, we would like to thank the OpenSSH community for their
continued support of the project, especially those who contributed
code or patches, reported bugs, tested snapshots or donated to the
project. More information on donations may be found at:
http://www.openssh.com/donations.html
Potentially-incompatible changes
================================
This release includes a number of changes that may affect existing
configurations:
* ssh(1)/sshd(8): Drop compatibility support for some very old SSH
implementations, including ssh.com <=2.* and OpenSSH <= 3.*. These
versions were all released in or before 2001 and predate the final
SSH RFCs. The support in question isn't necessary for RFC-compliant
SSH implementations.
Changes since OpenSSH 7.6
=========================
This is primarily a bugfix release.
New Features
------------
* All: Add experimental support for PQC XMSS keys (Extended Hash-
Based Signatures) based on the algorithm described in
https://tools.ietf.org/html/draft-irtf-cfrg-xmss-hash-based-signatures-12
The XMSS signature code is experimental and not compiled in by
default.
* sshd(8): Add a "rdomain" criteria for the sshd_config Match keyword
to allow conditional configuration that depends on which routing
domain a connection was received on (currently supported on OpenBSD
and Linux).
* sshd_config(5): Add an optional rdomain qualifier to the
ListenAddress directive to allow listening on different routing
domains. This is supported only on OpenBSD and Linux at present.
* sshd_config(5): Add RDomain directive to allow the authenticated
session to be placed in an explicit routing domain. This is only
supported on OpenBSD at present.
* sshd(8): Add "expiry-time" option for authorized_keys files to
allow for expiring keys.
* ssh(1): Add a BindInterface option to allow binding the outgoing
connection to an interface's address (basically a more usable
BindAddress)
* ssh(1): Expose device allocated for tun/tap forwarding via a new
%T expansion for LocalCommand. This allows LocalCommand to be used
to prepare the interface.
* sshd(8): Expose the device allocated for tun/tap forwarding via a
new SSH_TUNNEL environment variable. This allows automatic setup of
the interface and surrounding network configuration automatically on
the server.
* ssh(1)/scp(1)/sftp(1): Add URI support to ssh, sftp and scp, e.g.
ssh://user@host or sftp://user@host/path. Additional connection
parameters described in draft-ietf-secsh-scp-sftp-ssh-uri-04 are not
implemented since the ssh fingerprint format in the draft uses the
deprecated MD5 hash with no way to specify the any other algorithm.
* ssh-keygen(1): Allow certificate validity intervals that specify
only a start or stop time (instead of both or neither).
* sftp(1): Allow "cd" and "lcd" commands with no explicit path
argument. lcd will change to the local user's home directory as
usual. cd will change to the starting directory for session (because
the protocol offers no way to obtain the remote user's home
directory). bz#2760
* sshd(8): When doing a config test with sshd -T, only require the
attributes that are actually used in Match criteria rather than (an
incomplete list of) all criteria.
Bugfixes
--------
* ssh(1)/sshd(8): More strictly check signature types during key
exchange against what was negotiated. Prevents downgrade of RSA
signatures made with SHA-256/512 to SHA-1.
* sshd(8): Fix support for client that advertise a protocol version
of "1.99" (indicating that they are prepared to accept both SSHv1 and
SSHv2). This was broken in OpenSSH 7.6 during the removal of SSHv1
support. bz#2810
* ssh(1): Warn when the agent returns a ssh-rsa (SHA1) signature when
a rsa-sha2-256/512 signature was requested. This condition is possible
when an old or non-OpenSSH agent is in use. bz#2799
* ssh-agent(1): Fix regression introduced in 7.6 that caused ssh-agent
to fatally exit if presented an invalid signature request message.
* sshd_config(5): Accept yes/no flag options case-insensitively, as
has been the case in ssh_config(5) for a long time. bz#2664
* ssh(1): Improve error reporting for failures during connection.
Under some circumstances misleading errors were being shown. bz#2814
* ssh-keyscan(1): Add -D option to allow printing of results directly
in SSHFP format. bz#2821
* regress tests: fix PuTTY interop test broken in last release's SSHv1
removal. bz#2823
* ssh(1): Compatibility fix for some servers that erroneously drop the
connection when the IUTF8 (RFC8160) option is sent.
* scp(1): Disable RemoteCommand and RequestTTY in the ssh session
started by scp (sftp was already doing this.)
* ssh-keygen(1): Refuse to create a certificate with an unusable
number of principals.
* ssh-keygen(1): Fatally exit if ssh-keygen is unable to write all the
public key during key generation. Previously it would silently
ignore errors writing the comment and terminating newline.
* ssh(1): Do not modify hostname arguments that are addresses by
automatically forcing them to lower-case. Instead canonicalise them
to resolve ambiguities (e.g. ::0001 => ::1) before they are matched
against known_hosts. bz#2763
* ssh(1): Don't accept junk after "yes" or "no" responses to hostkey
prompts. bz#2803
* sftp(1): Have sftp print a warning about shell cleanliness when
decoding the first packet fails, which is usually caused by shells
polluting stdout of non-interactive startups. bz#2800
* ssh(1)/sshd(8): Switch timers in packet code from using wall-clock
time to monotonic time, allowing the packet layer to better function
over a clock step and avoiding possible integer overflows during
steps.
* Numerous manual page fixes and improvements.
Portability
-----------
* sshd(8): Correctly detect MIPS ABI in use at configure time. Fixes
sandbox violations on some environments.
* sshd(8): Remove UNICOS support. The hardware and software are literal
museum pieces and support in sshd is too intrusive to justify
maintaining.
* All: Build and link with "retpoline" flags when available to mitigate
the "branch target injection" style (variant 2) of the Spectre
branch-prediction vulnerability.
* All: Add auto-generated dependency information to Makefile.
* Numerous fixed to the RPM spec files.
Checksums:
==========
- SHA1 (openssh-7.7.tar.gz) = 24812e05fa233014c847c7775748316e7f8a836c
- SHA256 (openssh-7.7.tar.gz) = T4ua1L/vgAYqwB0muRahvnm5ZUr3PLY9nPljaG8egvo=
- SHA1 (openssh-7.7p1.tar.gz) = 446fe9ed171f289f0d62197dffdbfdaaf21c49f2
- SHA256 (openssh-7.7p1.tar.gz) = 1zvn5oTpnvzQJL4Vowv/y+QbASsvezyQhK7WIXdea48=
Please note that the SHA256 signatures are base64 encoded and not
hexadecimal (which is the default for most checksum tools). The PGP
key used to sign the releases is available as RELEASE_KEY.asc from
the mirror sites.
Reporting Bugs:
===============
- Please read http://www.openssh.com/report.html
Security bugs should be reported directly to openssh@openssh.com
================================
This release includes a number of changes that may affect existing
configurations:
* ssh(1): delete SSH protocol version 1 support, associated
configuration options and documentation.
* ssh(1)/sshd(8): remove support for the hmac-ripemd160 MAC.
* ssh(1)/sshd(8): remove support for the arcfour, blowfish and CAST
ciphers.
* Refuse RSA keys <1024 bits in length and improve reporting for keys
that do not meet this requirement.
* ssh(1): do not offer CBC ciphers by default.
Changes since OpenSSH 7.5
=========================
This is primarily a bugfix release. It also contains substantial
internal refactoring.
Security
--------
* sftp-server(8): in read-only mode, sftp-server was incorrectly
permitting creation of zero-length files. Reported by Michal
Zalewski.
New Features
------------
* ssh(1): add RemoteCommand option to specify a command in the ssh
config file instead of giving it on the client's command line. This
allows the configuration file to specify the command that will be
executed on the remote host.
* sshd(8): add ExposeAuthInfo option that enables writing details of
the authentication methods used (including public keys where
applicable) to a file that is exposed via a $SSH_USER_AUTH
environment variable in the subsequent session.
* ssh(1): add support for reverse dynamic forwarding. In this mode,
ssh will act as a SOCKS4/5 proxy and forward connections
to destinations requested by the remote SOCKS client. This mode
is requested using extended syntax for the -R and RemoteForward
options and, because it is implemented solely at the client,
does not require the server be updated to be supported.
* sshd(8): allow LogLevel directive in sshd_config Match blocks;
bz#2717
* ssh-keygen(1): allow inclusion of arbitrary string or flag
certificate extensions and critical options.
* ssh-keygen(1): allow ssh-keygen to use a key held in ssh-agent as
a CA when signing certificates. bz#2377
* ssh(1)/sshd(8): allow IPQoS=none in ssh/sshd to not set an explicit
ToS/DSCP value and just use the operating system default.
* ssh-add(1): added -q option to make ssh-add quiet on success.
* ssh(1): expand the StrictHostKeyChecking option with two new
settings. The first "accept-new" will automatically accept
hitherto-unseen keys but will refuse connections for changed or
invalid hostkeys. This is a safer subset of the current behaviour
of StrictHostKeyChecking=no. The second setting "off", is a synonym
for the current behaviour of StrictHostKeyChecking=no: accept new
host keys, and continue connection for hosts with incorrect
hostkeys. A future release will change the meaning of
StrictHostKeyChecking=no to the behaviour of "accept-new". bz#2400
* ssh(1): add SyslogFacility option to ssh(1) matching the equivalent
option in sshd(8). bz#2705
Bugfixes
--------
* ssh(1): use HostKeyAlias if specified instead of hostname for
matching host certificate principal names; bz#2728
* sftp(1): implement sorting for globbed ls; bz#2649
* ssh(1): add a user@host prefix to client's "Permission denied"
messages, useful in particular when using "stacked" connections
(e.g. ssh -J) where it's not clear which host is denying. bz#2720
* ssh(1): accept unknown EXT_INFO extension values that contain \0
characters. These are legal, but would previously cause fatal
connection errors if received.
* ssh(1)/sshd(8): repair compression statistics printed at
connection exit
* sftp(1): print '?' instead of incorrect link count (that the
protocol doesn't provide) for remote listings. bz#2710
* ssh(1): return failure rather than fatal() for more cases during
session multiplexing negotiations. Causes the session to fall back
to a non-mux connection if they occur. bz#2707
* ssh(1): mention that the server may send debug messages to explain
public key authentication problems under some circumstances; bz#2709
* Translate OpenSSL error codes to better report incorrect passphrase
errors when loading private keys; bz#2699
* sshd(8): adjust compatibility patterns for WinSCP to correctly
identify versions that implement only the legacy DH group exchange
scheme. bz#2748
* ssh(1): print the "Killed by signal 1" message only at LogLevel
verbose so that it is not shown at the default level; prevents it
from appearing during ssh -J and equivalent ProxyCommand configs.
bz#1906, bz#2744
* ssh-keygen(1): when generating all hostkeys (ssh-keygen -A), clobber
existing keys if they exist but are zero length. zero-length keys
could previously be made if ssh-keygen failed or was interrupted part
way through generating them. bz#2561
* ssh(1): fix pledge(2) violation in the escape sequence "~&" used to
place the current session in the background.
* ssh-keyscan(1): avoid double-close() on file descriptors; bz#2734
* sshd(8): avoid reliance on shared use of pointers shared between
monitor and child sshd processes. bz#2704
* sshd_config(8): document available AuthenticationMethods; bz#2453
* ssh(1): avoid truncation in some login prompts; bz#2768
* sshd(8): Fix various compilations failures, inc bz#2767
* ssh(1): make "--" before the hostname terminate argument processing
after the hostname too.
* ssh-keygen(1): switch from aes256-cbc to aes256-ctr for encrypting
new-style private keys. Fixes problems related to private key
handling for no-OpenSSL builds. bz#2754
* ssh(1): warn and do not attempt to use keys when the public and
private halves do not match. bz#2737
* sftp(1): don't print verbose error message when ssh disconnects
from under sftp. bz#2750
* sshd(8): fix keepalive scheduling problem: activity on a forwarded
port from preventing the keepalive from being sent; bz#2756
* sshd(8): when started without root privileges, don't require the
privilege separation user or path to exist. Makes running the
regression tests easier without touching the filesystem.
* Make integrity.sh regression tests more robust against timeouts.
bz#2658
* ssh(1)/sshd(8): correctness fix for channels implementation: accept
channel IDs greater than 0x7FFFFFFF.
Portability
-----------
* sshd(9): drop two more privileges in the Solaris sandbox:
PRIV_DAX_ACCESS and PRIV_SYS_IB_INFO; bz#2723
* sshd(8): expose list of completed authentication methods to PAM
via the SSH_AUTH_INFO_0 PAM environment variable. bz#2408
* ssh(1)/sshd(8): fix several problems in the tun/tap forwarding code,
mostly to do with host/network byte order confusion. bz#2735
* Add --with-cflags-after and --with-ldflags-after configure flags to
allow setting CFLAGS/LDFLAGS after configure has completed. These
are useful for setting sanitiser/fuzzing options that may interfere
with configure's operation.
* sshd(8): avoid Linux seccomp violations on ppc64le over the
socketcall syscall.
* Fix use of ldns when using ldns-config; bz#2697
* configure: set cache variables when cross-compiling. The cross-
compiling fallback message was saying it assumed the test passed,
but it wasn't actually set the cache variables and this would
cause later tests to fail.
* Add clang libFuzzer harnesses for public key parsing and signature
verification.
=========================
This is a major release, containing a number of new features as
well as a large internal re-factoring.
Potentially-incompatible changes
--------------------------------
* sshd(8): UseDNS now defaults to 'no'. Configurations that match
against the client host name (via sshd_config or authorized_keys)
may need to re-enable it or convert to matching against addresses.
New Features
------------
* Much of OpenSSH's internal code has been re-factored to be more
library-like. These changes are mostly not user-visible, but
have greatly improved OpenSSH's testability and internal layout.
* Add FingerprintHash option to ssh(1) and sshd(8), and equivalent
command-line flags to the other tools to control algorithm used
for key fingerprints. The default changes from MD5 to SHA256 and
format from hex to base64.
Fingerprints now have the hash algorithm prepended. An example of
the new format: SHA256:mVPwvezndPv/ARoIadVY98vAC0g+P/5633yTC4d/wXE
Please note that visual host keys will also be different.
* ssh(1), sshd(8): Experimental host key rotation support. Add a
protocol extension for a server to inform a client of all its
available host keys after authentication has completed. The client
may record the keys in known_hosts, allowing it to upgrade to better
host key algorithms and a server to gracefully rotate its keys.
The client side of this is controlled by a UpdateHostkeys config
option (default off).
* ssh(1): Add a ssh_config HostbasedKeyType option to control which
host public key types are tried during host-based authentication.
* ssh(1), sshd(8): fix connection-killing host key mismatch errors
when sshd offers multiple ECDSA keys of different lengths.
* ssh(1): when host name canonicalisation is enabled, try to
parse host names as addresses before looking them up for
canonicalisation. fixes bz#2074 and avoiding needless DNS
lookups in some cases.
* ssh-keygen(1), sshd(8): Key Revocation Lists (KRLs) no longer
require OpenSSH to be compiled with OpenSSL support.
* ssh(1), ssh-keysign(8): Make ed25519 keys work for host based
authentication.
* sshd(8): SSH protocol v.1 workaround for the Meyer, et al,
Bleichenbacher Side Channel Attack. Fake up a bignum key before
RSA decryption.
* sshd(8): Remember which public keys have been used for
authentication and refuse to accept previously-used keys.
This allows AuthenticationMethods=publickey,publickey to require
that users authenticate using two _different_ public keys.
* sshd(8): add sshd_config HostbasedAcceptedKeyTypes and
PubkeyAcceptedKeyTypes options to allow sshd to control what
public key types will be accepted. Currently defaults to all.
* sshd(8): Don't count partial authentication success as a failure
against MaxAuthTries.
* ssh(1): Add RevokedHostKeys option for the client to allow
text-file or KRL-based revocation of host keys.
* ssh-keygen(1), sshd(8): Permit KRLs that revoke certificates by
serial number or key ID without scoping to a particular CA.
* ssh(1): Add a "Match canonical" criteria that allows ssh_config
Match blocks to trigger only in the second config pass.
* ssh(1): Add a -G option to ssh that causes it to parse its
configuration and dump the result to stdout, similar to "sshd -T".
* ssh(1): Allow Match criteria to be negated. E.g. "Match !host".
* The regression test suite has been extended to cover more OpenSSH
features. The unit tests have been expanded and now cover key
exchange.
Bugfixes
* ssh-keyscan(1): ssh-keyscan has been made much more robust again
servers that hang or violate the SSH protocol.
* ssh(1), ssh-keygen(1): Fix regression bz#2306: Key path names were
being lost as comment fields.
* ssh(1): Allow ssh_config Port options set in the second config
parse phase to be applied (they were being ignored). bz#2286
* ssh(1): Tweak config re-parsing with host canonicalisation - make
the second pass through the config files always run when host name
canonicalisation is enabled (and not whenever the host name
changes) bz#2267
* ssh(1): Fix passing of wildcard forward bind addresses when
connection multiplexing is in use; bz#2324;
* ssh-keygen(1): Fix broken private key conversion from non-OpenSSH
formats; bz#2345.
* ssh-keygen(1): Fix KRL generation bug when multiple CAs are in
use.
* Various fixes to manual pages: bz#2288, bz#2316, bz#2273
Portable OpenSSH
* Support --without-openssl at configure time
Disables and removes dependency on OpenSSL. Many features,
including SSH protocol 1 are not supported and the set of crypto
options is greatly restricted. This will only work on systems
with native arc4random or /dev/urandom.
Considered highly experimental for now.
* Support --without-ssh1 option at configure time
Allows disabling support for SSH protocol 1.
* sshd(8): Fix compilation on systems with IPv6 support in utmpx; bz#2296
* Allow custom service name for sshd on Cygwin. Permits the use of
multiple sshd running with different service names.
Checksums:
==========
- SHA1 (openssh-6.8.tar.gz) = 99903c6ca76e0a2c044711017f81127e12459d37
- SHA256 (openssh-6.8.tar.gz) = N1uzVarFbrm2CzAwuDu3sRoszmqpK+5phAChP/QNyuw=
- SHA1 (openssh-6.8p1.tar.gz) = cdbc51e46a902b30d263b05fdc71340920e91c92
- SHA256 (openssh-6.8p1.tar.gz) = P/ZM5z7hJEgLW/dnuYMNfTwDu8tqvnFrePAZLDfOFg4=
Please note that the PGP key used to sign releases was recently rotated.
The new key has been signed by the old key to provide continuity. It is
available from the mirror sites as RELEASE_KEY.asc.
Reporting Bugs:
===============
- Please read http://www.openssh.com/report.html
Security bugs should be reported directly to openssh@openssh.com
OpenSSH is brought to you by Markus Friedl, Niels Provos, Theo de Raadt,
Kevin Steves, Damien Miller, Darren Tucker, Jason McIntyre, Tim Rice and
Ben Lindstrom.
=========================
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.
christos