Call for testing: openssh-5.2

Damien Miller
Mon, 16 Feb 2009 04:32:26 -0000

Hi,

OpenSSH 5.2 is almost ready for release, so we would appreciate testing
on as many platforms and systems as possible. This is primarily a bug-fix
release, to follow the feature-focused 5.1 release.

Snapshot releases for portable OpenSSH are available from
http://www.mindrot.org/openssh_snap/

The OpenBSD version is available in CVS HEAD:
http://www.openbsd.org/anoncvs.html

Portable OpenSSH is also available via anonymous CVS using the
instructions at http://www.openssh.com/portable.html#cvs

Running the regression tests supplied with Portable OpenSSH does not
require installation and is a simply:

$ ./configure && make tests

Live testing on suitable non-production systems is also appreciated.
Please send reports of success or failure to
openssh-unix-dev at mindrot.org.

Below is a summary of changes. More detail may be found in the
ChangeLog in the portable OpenSSH tarballs.

Thanks to the many people who contributed to this release.


Changes since OpenSSH 5.1
========================
Security:

 * This release changes the default cipher order to prefer the AES CTR
   modes and the revised "arcfour256" mode to CBC mode ciphers that
are
   susceptible to CPNI-957037 "Plaintext Recovery Attack Against SSH".

 * This release also adds countermeasures to mitigate CPNI-957037-style
   attacks against the SSH protocol's use of CBC-mode ciphers. Upon
   detection of an invalid packet length or Message Authentication
   Code, ssh/sshd will continue reading up to the maximum supported
   packet length rather than immediately terminating the connection.
   This eliminates most of the known differences in behaviour that
   leaked information about the plaintext of injected data which formed
   the basis of this attack. We believe that these attacks are rendered
   infeasible by these changes.

New features:

 * Added a -y option to ssh(1) to force logging to syslog rather than
   stderr, which is useful when running daemonised (ssh -f)

 * The sshd_config(5) ForceCommand directive now accepts commandline
   arguments for the internal-sftp server.

 * The ssh(1) ~C escape commandline now support runtime creation of
   dynamic (-D) port forwards.

 * Support the SOCKS4A protocol in ssh(1) dynamic (-D) forwards.
   (bz#1482)

 * Support remote port forwarding with a listen port of '0'. This
   informs the server that it should dynamically allocate a listen
   port and report it back to the client. (bz#1003)

 * sshd(8) now supports setting PermitEmptyPasswords and
   AllowAgentForwarding in Match blocks

Bug and documentation fixes

 * Repair a ssh(1) crash introduced in openssh-5.1 when the client is
   sent a zero-length banner (bz#1496)

 * Due to interoperability problems with certain
   broken SSH implementations, the eow at openssh.com and
   no-more-sessions at openssh.com protocol extensions are now only sent
   to peers that identify themselves as OpenSSH.

 * Make ssh(1) send the correct channel number for
   SSH2_MSG_CHANNEL_SUCCESS and SSH2_MSG_CHANNEL_FAILURE messages to
   avoid triggering 'Non-public channel' error messages on sshd(8) in
   openssh-5.1.

 * Avoid printing 'Non-public channel' warnings in sshd(8), since the
   ssh(1) has sent incorrect channel numbers since ~2004 (this reverts
   a behaviour introduced in openssh-5.1).

 * Avoid double-free in ssh(1) ~C escape -L handler (bz#1539)

 * Correct fail-on-error behaviour in sftp(1) batchmode for remote
   stat operations. (bz#1541)

 * Disable nonfunctional ssh(1) ~C escape handler in multiplex slave
   connections. (bz#1543)

 * Avoid hang in ssh(1) when attempting to connect to a server that
   has MaxSessions=0 set.

 * Multiple fixes to sshd(8) configuration test (-T) mode

 * Several core and portable OpenSSH bugs fixed: 1380, 1412, 1418,
   1419, 1421, 1490, 1491, 1492, 1514, 1515, 1518, 1520, 1538, 1540

 * Many manual page improvements.


-d