Hi, OpenSSH 9.8p1 is almost ready for release, so we would appreciate testing on as many platforms and systems as possible. This is a bugfix 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 git using the instructions at http://www.openssh.com/portable.html#cvs At https://anongit.mindrot.org/openssh.git/ or via a mirror at Github: https://github.com/openssh/openssh-portable 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@xxxxxxxxxxx. Security bugs should be reported directly to openssh@xxxxxxxxxxx. 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. Future deprecation notice ========================= OpenSSH plans to remove support for the DSA signature algorithm in early 2025. This release disables DSA by default at compile time. DSA, as specified in the SSHv2 protocol, is inherently weak - being limited to a 160 bit private key and use of the SHA1 digest. Its estimated security level is only 80 bits symmetric equivalent. OpenSSH has disabled DSA keys by default since 2015 but has retained run-time optional support for them. DSA was the only mandatory-to- implement algorithm in the SSHv2 RFCs, mostly because alternative algorithms were encumbered by patents when the SSHv2 protocol was specified. This has not been the case for decades at this point and better algorithms are well supported by all actively-maintained SSH implementations. We do not consider the costs of maintaining DSA in OpenSSH to be justified and hope that removing it from OpenSSH can accelerate its wider deprecation in supporting cryptography libraries. This release, and its deactivation of DSA by default at compile-time, marks the second step in our timeline to finally deprecate DSA. The final step of removing DSA support entirely is planned for the first OpenSSH release of 2025. Potentially-incompatible changes -------------------------------- * all: as mentioned above, the DSA signature algorithm is now disabled at compile time. * sshd(8): the server will now block client addresses that repeatedly fail authentication, repeatedly connect without ever completing authentication or that crash the server. See the discussion of PerSourcePenalties below for more information. Operators of servers that accept connections from many users, or servers that accept connections from addresses behind NAT or proxies may need to consider these settings. * sshd(8): the server has been split into a listener binary, sshd(8), and a per-session binary "sshd-session". This allows for a much smaller listener binary, as it no longer needs to support the SSH protocol. As part of this work, support for disabling privilege separation (which previously required code changes to disable) and disabling re-execution of sshd(8) has been removed. Further separation of sshd-session into additional, minimal binaries is planned for the future. * sshd(8): several log messages have changed. In particular, some log messages will be tagged with as originating from a process named "sshd-session" rather than "sshd". * ssh-keyscan(1): this tool previously emitted comment lines containing the hostname and SSH protocol banner to standard error. This release now emits them to standard output, but adds a new "-q" flag to silence them altogether. * sshd(8): (portable OpenSSH only) sshd will no longer use argv[0] as the PAM service name. A new "PAMServiceName" sshd_config(5) directive allows selecting the service name at runtime. This defaults to "sshd". bz2101 Changes since OpenSSH 9.7 ========================= This release contains mostly bugfixes. New features ------------ * sshd(8): add the ability to penalise client addresses that, for various reasons, do not successfully complete authentication. sshd(8) will now identify situations where the session did not authenticate as expected. These conditions include when the client repeatedly attempted authentication unsucessfully (possibly indicating an attack against one or more accounts, e.g. password guessing), or when client behaviour caused sshd to crash (possibly indicating attempts to exploit sshd). When such a condition is observed, sshd will record a penalty of some duration (e.g. 30 seconds) against the client's address. If this time is above a minimum configurable threshold, then all connections from the client address will be refused (along with any others in the same PerSourceNetBlockSize CIDR range). Repeated offenses by the same client address will accrue greater penalties, up to a configurable maximum. Address ranges may be exempted from penalties using the PerSourcePenaltyExemptList option. We hope these options will make it significantly more difficult for attackers to find accounts with weak/guessable passwords or exploit bugs in sshd(8) itself. This option is enabled by default. * ssh(8): allow the HostkeyAlgorithms directive to disable the implicit fallback from certificate host key to plain host keys. Bugfixes -------- * misc: fix a number of inaccuracies in the PROTOCOL.* documentation. GHPR430 GHPR487 * all: switch to strtonum(3) for more robust integer parsing in most places. * ssh(1), sshd(8): correctly restore sigprocmask around ppoll() * ssh-keysign(8): stricter validation of messaging socket fd GHPR492 * sftp(1): flush stdout after writing "sftp>" prompt when not using editline. GHPR480 * sftp-server(8): fix home-directory extension implementation, it previously always returned the current user's home directory contrary to the spec. GHPR477 * ssh-keyscan(1): do not close stdin in any case to prevent error messages when stdin is read multiple times. E.g. echo localhost | ssh-keyscan -f - -f - * regression tests: fix rekey test that was testing the same KEX algorithm repeatedly instead of testing all of them. bz3692 * ssh_config(5), sshd_config(5): clarify the KEXAlgorithms directive documentation, especially around what is supported vs available. bz3701. Portability ----------- * sshd(8): expose SSH_AUTH_INFO_0 always to PAM auth modules unconditionally. The previous behaviour was to expose it only when particular authentication methods were in use. * build: fix OpenSSL ED25519 support detection. An incorrect function signature in configure.ac previously prevented enabling the recently added support for ED25519 private keys in PEM PKCS8 format. * ssh(1), ssh-agent(8): allow the presence of the WAYLAND_DISPLAY environment variable to enable SSH_ASKPASS, similarly to the X11 DISPLAY environment variable. GHPR479 * build: improve detection of the -fzero-call-used-regs compiler flag. bz3673. * build: relax OpenSSL version check to accept all OpenSSL 3.x versions. * sshd(8): add support for notifying systemd on server listen and reload, using a standalone implementation that doesn't depend on libsystemd. bz2641 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. _______________________________________________ openssh-unix-dev mailing list openssh-unix-dev@xxxxxxxxxxx https://lists.mindrot.org/mailman/listinfo/openssh-unix-dev
