Highlights from the release notes are reproduced below. Bug fixes and
improvements that were previously merged into FreeBSD have been elided.
See the upstream release notes for full details of the 9.9p1 release
(https://www.openssh.com/releasenotes.html).
---
Future deprecation notice
=========================
OpenSSH plans to remove support for the DSA signature algorithm in
early 2025.
Potentially-incompatible changes
--------------------------------
* ssh(1): remove support for pre-authentication compression.
* ssh(1), sshd(8): processing of the arguments to the "Match"
configuration directive now follows more shell-like rules for
quoted strings, including allowing nested quotes and \-escaped
characters.
New features
------------
* ssh(1), sshd(8): add support for a new hybrid post-quantum key
exchange based on the FIPS 203 Module-Lattice Key Enapsulation
mechanism (ML-KEM) combined with X25519 ECDH as described by
https://datatracker.ietf.org/doc/html/draft-kampanakis-curdle-ssh-pq-ke-03
This algorithm "mlkem768x25519-sha256" is available by default.
* ssh(1), sshd(8), ssh-agent(1): prevent private keys from being
included in core dump files for most of their lifespans. This is
in addition to pre-existing controls in ssh-agent(1) and sshd(8)
that prevented coredumps. This feature is supported on OpenBSD,
Linux and FreeBSD.
* All: convert key handling to use the libcrypto EVP_PKEY API, with
the exception of DSA.
Bugfixes
--------
* sshd(8): do not apply authorized_keys options when signature
verification fails. Prevents more restrictive key options being
incorrectly applied to subsequent keys in authorized_keys. bz3733
* ssh-keygen(1): include pathname in some of ssh-keygen's passphrase
prompts. Helps the user know what's going on when ssh-keygen is
invoked via other tools. Requested in GHPR503
* ssh(1), ssh-add(1): make parsing user@host consistently look for
the last '@' in the string rather than the first. This makes it
possible to more consistently use usernames that contain '@'
characters.
* ssh(1), sshd(8): be more strict in parsing key type names. Only
allow short names (e.g "rsa") in user-interface code and require
full SSH protocol names (e.g. "ssh-rsa") everywhere else. bz3725
* ssh-keygen(1): clarify that ed25519 is the default key type
generated and clarify that rsa-sha2-512 is the default signature
scheme when RSA is in use. GHPR505
---
Reviewed by: jlduran (build infrastructure)
Reviewed by: cy (build infrastructure)
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D48947
(cherry picked from commit 3d9fd9fcb4)
Approved by: re (accelerated MFC)
Highlights from the release notes are reproduced below. Some security
and bug fixes were previously merged into FreeBSD and have been elided.
See the upstream release notes for full details
(https://www.openssh.com/releasenotes.html).
---
Future deprecation notice
=========================
OpenSSH plans to remove support for the DSA signature algorithm in
early 2025.
Potentially-incompatible changes
--------------------------------
* 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
New features
------------
* sshd(8): sshd(8) will now penalise client addresses that, for various
reasons, do not successfully complete authentication. This feature is
controlled by a new sshd_config(5) PerSourcePenalties option and is
on by default.
* ssh(8): allow the HostkeyAlgorithms directive to disable the
implicit fallback from certificate host key to plain host keys.
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.
* 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
---
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D48914
(cherry picked from commit 0fdf8fae8b)
(cherry picked from commit b4bb480ae9)
(cherry picked from commit e95979047a)
(cherry picked from commit dcb4ae528d)
Approved by: re (accelerated MFC)
From the release notes,
> This release contains a number of security fixes, some small features
> and bugfixes.
The most significant change in 9.6p1 is a set of fixes for a newly-
discovered weakness in the SSH transport protocol. The fix was already
merged into FreeBSD and released as FreeBSD-SA-23:19.openssh.
Full release notes at https://www.openssh.com/txt/release-9.6
Relnotes: Yes
Sponsored by: The FreeBSD Foundation
(cherry picked from commit 069ac18495)
Excerpts from the release notes:
* ssh-agent(1): PKCS#11 modules must now be specified by their full
paths. Previously dlopen(3) could search for them in system
library directories.
* ssh(1): allow forwarding Unix Domain sockets via ssh -W.
* ssh(1): add support for configuration tags to ssh(1).
This adds a ssh_config(5) "Tag" directive and corresponding
"Match tag" predicate that may be used to select blocks of
configuration similar to the pf.conf(5) keywords of the same
name.
* ssh(1): add a "match localnetwork" predicate. This allows matching
on the addresses of available network interfaces and may be used to
vary the effective client configuration based on network location.
* ssh-agent(1): improve isolation between loaded PKCS#11 modules
by running separate ssh-pkcs11-helpers for each loaded provider.
* ssh-agent(1), ssh(1): improve defences against invalid PKCS#11
modules being loaded by checking that the requested module
contains the required symbol before loading it.
* ssh(1): don't incorrectly disable hostname canonicalization when
CanonicalizeHostname=yes and ProxyJump was expicitly set to
"none". bz3567
Full release notes at https://www.openssh.com/txt/release-9.4
Relnotes: Yes
Sponsored by: The FreeBSD Foundation
Release notes are available at https://www.openssh.com/txt/release-9.2
OpenSSH 9.2 contains fixes for two security problems and a memory safety
problem. The memory safety problem is not believed to be exploitable.
These fixes have already been committed to OpenSSH 9.1 in FreeBSD.
Some other notable items from the release notes:
* ssh(1): add a new EnableEscapeCommandline ssh_config(5) option that
controls whether the client-side ~C escape sequence that provides a
command-line is available. Among other things, the ~C command-line
could be used to add additional port-forwards at runtime.
* sshd(8): add support for channel inactivity timeouts via a new
sshd_config(5) ChannelTimeout directive. This allows channels that
have not seen traffic in a configurable interval to be
automatically closed. Different timeouts may be applied to session,
X11, agent and TCP forwarding channels.
* sshd(8): add a sshd_config UnusedConnectionTimeout option to
terminate client connections that have no open channels for a
length of time. This complements the ChannelTimeout option above.
* sshd(8): add a -V (version) option to sshd like the ssh client has.
* scp(1), sftp(1): add a -X option to both scp(1) and sftp(1) to
allow control over some SFTP protocol parameters: the copy buffer
length and the number of in-flight requests, both of which are used
during upload/download. Previously these could be controlled in
sftp(1) only. This makes them available in both SFTP protocol
clients using the same option character sequence.
* ssh-keyscan(1): allow scanning of complete CIDR address ranges,
e.g. "ssh-keyscan 192.168.0.0/24". If a CIDR range is passed, then
it will be expanded to all possible addresses in the range
including the all-0s and all-1s addresses. bz#976
* ssh(1): support dynamic remote port forwarding in escape
command-line's -R processing. bz#3499
MFC after: 1 week
Sponsored by: The FreeBSD Foundation
Release notes are available at https://www.openssh.com/txt/release-9.1
9.1 contains fixes for three minor memory safety problems; these have
lready been merged to the copy of OpenSSH 9.0 that is in the FreeBSD base
system.
Some highlights copied from the release notes:
Potentially-incompatible changes
--------------------------------
* ssh(1), sshd(8): SetEnv directives in ssh_config and sshd_config
are now first-match-wins to match other directives. Previously
if an environment variable was multiply specified the last set
value would have been used. bz3438
* ssh-keygen(8): ssh-keygen -A (generate all default host key types)
will no longer generate DSA keys, as these are insecure and have
not been used by default for some years.
New features
------------
* ssh(1), sshd(8): add a RequiredRSASize directive to set a minimum
RSA key length. Keys below this length will be ignored for user
authentication and for host authentication in sshd(8).
* sftp-server(8): add a "users-groups-by-id@openssh.com" extension
request that allows the client to obtain user/group names that
correspond to a set of uids/gids.
* sftp(1): use "users-groups-by-id@openssh.com" sftp-server
extension (when available) to fill in user/group names for
directory listings.
* sftp-server(8): support the "home-directory" extension request
defined in draft-ietf-secsh-filexfer-extensions-00. This overlaps
a bit with the existing "expand-path@openssh.com", but some other
clients support it.
* ssh-keygen(1), sshd(8): allow certificate validity intervals,
sshsig verification times and authorized_keys expiry-time options
to accept dates in the UTC time zone in addition to the default
of interpreting them in the system time zone. YYYYMMDD and
YYMMDDHHMM[SS] dates/times will be interpreted as UTC if suffixed
with a 'Z' character.
Also allow certificate validity intervals to be specified in raw
seconds-since-epoch as hex value, e.g. -V 0x1234:0x4567890. This
is intended for use by regress tests and other tools that call
ssh-keygen as part of a CA workflow. bz3468
* sftp(1): allow arguments to the sftp -D option, e.g. sftp -D
"/usr/libexec/sftp-server -el debug3"
* ssh-keygen(1): allow the existing -U (use agent) flag to work
with "-Y sign" operations, where it will be interpreted to require
that the private keys is hosted in an agent; bz3429
MFC after: 2 weeks
Relnotes: Yes
Sponsored by: The FreeBSD Foundation
FreeBSD introduced VersionAddendum for the server as a local change in
2001 in commit 933ca70f8f and later extended it to the client in
commit 9e2cbe04ff.
In 2012 upstream added support for server VersionAddendum, in commit
23528816dc10. They do not support it for the client.
The argument for supporting this in the client is not nearly as strong
as for the server, so retire this option to reduce the scope of our
local patch set. This also avoids some cases of conflicts in ssh_config
during update, as a user's configuration would typically follow the
commented-out default VersionAddendum value.
Reviewed by: gordon, glebius
Relnotes: yes
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D32930
After we moved to git $FreeBSD$ is no longer expanded and serves no
purpose. Remove them from OpenSSH to reduce diffs against upstream.
Sponsored by: The FreeBSD Foundation
Release notes are available at https://www.openssh.com/txt/release-9.0
Some highlights:
* ssh(1), sshd(8): use the hybrid Streamlined NTRU Prime + x25519 key
exchange method by default ("sntrup761x25519-sha512@openssh.com").
The NTRU algorithm is believed to resist attacks enabled by future
quantum computers and is paired with the X25519 ECDH key exchange
(the previous default) as a backstop against any weaknesses in
NTRU Prime that may be discovered in the future. The combination
ensures that the hybrid exchange offers at least as good security
as the status quo.
* sftp-server(8): support the "copy-data" extension to allow server-
side copying of files/data, following the design in
draft-ietf-secsh-filexfer-extensions-00. bz2948
* sftp(1): add a "cp" command to allow the sftp client to perform
server-side file copies.
This commit excludes the scp(1) change to use the SFTP protocol by
default; that change will immediately follow.
MFC after: 1 month
Relnotes: Yes
Sponsored by: The FreeBSD Foundation
Release notes are available at https://www.openssh.com/txt/release-8.9
Some highlights:
* ssh(1), sshd(8), ssh-add(1), ssh-agent(1): add a system for
restricting forwarding and use of keys added to ssh-agent(1)
* ssh(1), sshd(8): add the sntrup761x25519-sha512@openssh.com hybrid
ECDH/x25519 + Streamlined NTRU Prime post-quantum KEX to the
default KEXAlgorithms list (after the ECDH methods but before the
prime-group DH ones). The next release of OpenSSH is likely to
make this key exchange the default method.
* sshd(8), portable OpenSSH only: this release removes in-built
support for MD5-hashed passwords. If you require these on your
system then we recommend linking against libxcrypt or similar.
Future deprecation notice
=========================
A near-future release of OpenSSH will switch scp(1) from using the
legacy scp/rcp protocol to using SFTP by default.
Legacy scp/rcp performs wildcard expansion of remote filenames (e.g.
"scp host:* .") through the remote shell. This has the side effect of
requiring double quoting of shell meta-characters in file names
included on scp(1) command-lines, otherwise they could be interpreted
as shell commands on the remote side.
MFC after: 1 month
Relnotes: Yes
Sponsored by: The FreeBSD Foundation
OpenSSH v8.8p1 was motivated primarily by a security update and
deprecation of RSA/SHA1 signatures. It also has a few minor bug fixes.
The security update was already applied to FreeBSD as an independent
change, and the RSA/SHA1 deprecation is excluded from this commit but
will immediately follow.
MFC after: 1 month
Relnotes: Yes
Sponsored by: The FreeBSD Foundation
Some notable changes, from upstream's release notes:
- sshd(8): Remove support for obsolete "host/port" syntax.
- ssh(1): When prompting whether to record a new host key, accept the key
fingerprint as a synonym for "yes".
- ssh-keygen(1): when acting as a CA and signing certificates with an RSA
key, default to using the rsa-sha2-512 signature algorithm.
- ssh(1), sshd(8), ssh-keygen(1): this release removes the "ssh-rsa"
(RSA/SHA1) algorithm from those accepted for certificate signatures.
- ssh-sk-helper(8): this is a new binary. It is used by the FIDO/U2F
support to provide address-space isolation for token middleware
libraries (including the internal one).
- ssh(1): this release enables UpdateHostkeys by default subject to some
conservative preconditions.
- scp(1): this release changes the behaviour of remote to remote copies
(e.g. "scp host-a:/path host-b:") to transfer through the local host
by default.
- scp(1): experimental support for transfers using the SFTP protocol as
a replacement for the venerable SCP/RCP protocol that it has
traditionally used.
Additional integration work is needed to support FIDO/U2F in the base
system.
Deprecation Notice
------------------
OpenSSH will disable the ssh-rsa signature scheme by default in the
next release.
Reviewed by: imp
MFC after: 1 month
Relnotes: Yes
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D29985
This completely removes client-side support for the SSH 1 protocol,
which was already disabled in 12 but is still enabled in 11. For that
reason, we will not be able to merge 7.6p1 or newer back to 11.
I have worked hard to reduce diffs against the vendor branch. One
notable change in that respect is that we no longer prefer DSA over
RSA - the reasons for doing so went away years ago. This may cause
some surprises, as ssh will warn about unknown host keys even for
hosts whose keys haven't changed.
MFC after: 6 weeks
