Changelog
openssh (1:7.8p1-1) unstable; urgency=medium
* New upstream release (https://www.openssh.com/txt/release-7.8, closes:
#907534):
- ssh-keygen(1): Write OpenSSH format private keys by default instead of
using OpenSSL's PEM format (closes: #905407). The OpenSSH format,
supported in OpenSSH releases since 2014 and described in the
PROTOCOL.key file in the source distribution, offers substantially
better protection against offline password guessing and supports key
comments in private keys. If necessary, it is possible to write old
PEM-style keys by adding "-m PEM" to ssh-keygen's arguments when
generating or updating a key.
- sshd(8): Remove internal support for S/Key multiple factor
authentication. S/Key may still be used via PAM or BSD auth.
- ssh(1): Remove vestigial support for running ssh(1) as setuid. This
used to be required for hostbased authentication and the (long gone)
rhosts-style authentication, but has not been necessary for a long
time. Attempting to execute ssh as a setuid binary, or with uid !=
effective uid will now yield a fatal error at runtime.
- sshd(8): The semantics of PubkeyAcceptedKeyTypes and the similar
HostbasedAcceptedKeyTypes options have changed. These now specify
signature algorithms that are accepted for their respective
authentication mechanism, where previously they specified accepted key
types. This distinction matters when using the RSA/SHA2 signature
algorithms "rsa-sha2-256", "rsa-sha2-512" and their certificate
counterparts. Configurations that override these options but omit
these algorithm names may cause unexpected authentication failures (no
action is required for configurations that accept the default for
these options).
- sshd(8): The precedence of session environment variables has changed.
~/.ssh/environment and environment="..." options in authorized_keys
files can no longer override SSH_* variables set implicitly by sshd.
- ssh(1)/sshd(8): The default IPQoS used by ssh/sshd has changed. They
will now use DSCP AF21 for interactive traffic and CS1 for bulk. For
a detailed rationale, please see the commit message:
https://cvsweb.openbsd.org/src/usr.bin/ssh/readconf.c#rev1.284
- ssh(1)/sshd(8): Add new signature algorithms "rsa-sha2-256-cert-
<email address hidden>" and "<email address hidden>" to explicitly
force use of RSA/SHA2 signatures in authentication.
- sshd(8): Extend the PermitUserEnvironment option to accept a whitelist
of environment variable names in addition to global "yes" or "no"
settings.
- sshd(8): Add a PermitListen directive to sshd_config(5) and a
corresponding permitlisten= authorized_keys option that control which
listen addresses and port numbers may be used by remote forwarding
(ssh -R ...).
- sshd(8): Add some countermeasures against timing attacks used for
account validation/enumeration. sshd will enforce a minimum time or
each failed authentication attempt consisting of a global 5ms minimum
plus an additional per-user 0-4ms delay derived from a host secret.
- sshd(8): Add a SetEnv directive to allow an administrator to
explicitly specify environment variables in sshd_config. Variables
set by SetEnv override the default and client-specified environment.
- ssh(1): Add a SetEnv directive to request that the server sets an
environment variable in the session. Similar to the existing SendEnv
option, these variables are set subject to server configuration.
- ssh(1): Allow "SendEnv -PATTERN" to clear environment variables
previously marked for sending to the server (closes: #573316).
- ssh(1)/sshd(8): Make UID available as a %-expansion everywhere that
the username is available currently.
- ssh(1): Allow setting ProxyJump=none to disable ProxyJump
functionality.
- sshd(8): Avoid observable differences in request parsing that could be
used to determine whether a target user is valid.
- ssh(1)/sshd(8): Fix some memory leaks.
- ssh(1): Fix a pwent clobber (introduced in openssh-7.7) that could
occur during key loading, manifesting as crash on some platforms.
- sshd_config(5): Clarify documentation for AuthenticationMethods
option.
- ssh(1): Ensure that the public key algorithm sent in a public key
SSH_MSG_USERAUTH_REQUEST matches the content of the signature blob.
Previously, these could be inconsistent when a legacy or non-OpenSSH
ssh-agent returned a RSA/SHA1 signature when asked to make a RSA/SHA2
signature.
- sshd(8): Fix failures to read authorized_keys caused by faulty
supplemental group caching.
- scp(1): Apply umask to directories, fixing potential mkdir/chmod race
when copying directory trees.
- ssh-keygen(1): Return correct exit code when searching for and hashing
known_hosts entries in a single operation.
- ssh(1): Prefer the ssh binary pointed to via argv[0] to $PATH when
re-executing ssh for ProxyJump.
- sshd(8): Do not ban PTY allocation when a sshd session is restricted
because the user password is expired as it breaks password change
dialog.
- ssh(1)/sshd(8): Fix error reporting from select() failures.
- ssh(1): Improve documentation for -w (tunnel) flag, emphasising that
-w implicitly sets Tunnel=point-to-point.
- ssh-agent(1): Implement EMFILE mitigation for ssh-agent. ssh-agent
will no longer spin when its file descriptor limit is exceeded.
- ssh(1)/sshd(8): Disable SSH2_MSG_DEBUG messages for Twisted Conch
clients. Twisted Conch versions that lack a version number in their
identification strings will mishandle these messages when running on
Python 2.x (https://twistedmatrix.com/trac/ticket/9422).
- sftp(1): Notify user immediately when underlying ssh process dies
expectedly.
- ssh(1)/sshd(8): Fix tunnel forwarding; regression in 7.7 release.
- ssh-agent(1): Don't kill ssh-agent's listening socket entirely if it
fails to accept(2) a connection.
- ssh(1): Add some missing options in the configuration dump output (ssh
-G).
- sshd(8): Expose details of completed authentication to PAM auth
modules via SSH_AUTH_INFO_0 in the PAM environment.
* Switch debian/watch to HTTPS.
* Temporarily work around https://twistedmatrix.com/trac/ticket/9515 in
regression tests.
-- Colin Watson <email address hidden> Thu, 30 Aug 2018 15:35:27 +0100
