Announce: OpenSSH 7.7 released

[Damien Miller <djm () openbsd org>]

OpenSSH 7.7 has just been released. It will be available from the
mirrors listed at http://www.openssh.com/ shortly.

OpenSSH is a 100% complete SSH protocol 2.0 implementation and
includes sftp client and server support.

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