Full release notes are available at
https://www.openssh.com/txt/release-10.4
Selected highlights from the release notes:
Potentially-incompatible changes
--------------------------------
* sshd(8): configuration dump mode ("sshd -G") now writes directives
in mixed case (e.g. "PubkeyAuthentication") whereas previously it
emitted only lower-case names.
* ssh(1), sshd(8): make the transport protocol stricter by
disconnecting if the peer sends non-KEX messages during a post-
authentication key re-exchange. Previously a malicious peer could
continue sending non-key exchange messages without penalty. These
would be buffered, causing memory to be wasted up until the
connection terminated or the server/client hit a memory limit.
Implementations that do not restrict messages sent during key
exchange as per RFC4253 section 7.1 may be disconnected.
Reported by Marko Jevtic.
Changes since OpenSSH 10.3
==========================
This release contains a number of security fixes as well as general
bugfixes and a couple of new features.
Security
========
* sftp(1): when downloading files on the command-line using
"sftp host:/path .", a malicious server could cause the file to
be downloaded to an unexpected location. This issue was identified
by the Swival Security Scanner.
* scp(1): when copying files between two remote destinations, do
not allow a malicious server to write files to the parent
directory of the intended target directory. This issue was
identified by the Swival Security Scanner.
* sshd(8): DisableForwarding=yes didn't override PermitTunnel=yes
as it was documented to do. Note that PermitTunnel is not enabled
by default. Reported independently by Huzaifa Sidhpurwala of
Redhat and Marko Jevtic.
* sshd(8): avoid a potential pre-authentication denial of service
when GSSAPIAuthentication was enabled (this feature is off by
default). This was not mitigated by MaxAuthTries, but would be
penalised by PerSourcePenalties. This was reported by Manfred
Kaiser of the milCERT AT (Austrian Ministry of Defence).
* sshd(8): fix a number of cases where the minimum authentication
delay was not being enforced. Reported by the Orange Cyberdefense
Vulnerability Team.
* ssh(1): fix a possible client-side use-after-free if the server
changes its host key during a key reexchange. This was reported by
Zhenpeng (Leo) Lin of Depthfirst.
New features
------------
* All: add experimental support for a composite post-quantum
signature scheme that combines ML-DSA 44 and Ed25519 as specified
in draft-miller-sshm-mldsa44-ed25519-composite-sigs.
This scheme is not enabled by default. To use it, you'll need
to add it to HostKeyAlgorithms, PubkeyAcceptedAlgorithms, etc.
Keys may be generated using "ssh-keygen -t mldsa44-ed25519".
Bugfixes
--------
* sshd(8): avoid sending observably different messages for valid vs
invalid users in GSSAPIAuthentication (disabled by default).
* ssh(1), sshd(8): fix several bugs that incorrectly
classified bulk traffic as interactive. bz3972, bz3958
* ssh-keygen(1), ssh-add(1): skip unsupported key types when
downloading resident keys from a FIDO token. Previously, downloads
would abort when one was encountered. GHPR657
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D58083
Full release notes are available at
https://www.openssh.com/txt/release-10.3
Selected highlights from the release notes:
* ssh(1), sshd(8): remove bug compatibility for implementations
that don't support rekeying. If such an implementation tries to
interoperate with OpenSSH, it will now eventually fail when the
transport needs rekeying.
* ssh(1), sshd(8): support IANA-assigned codepoints for SSH agent
forwarding, as per draft-ietf-sshm-ssh-agent. Support for the new
names is advertised via the EXT_INFO message. If a server offers
support for the new names, then they are used preferentially.
* ssh(1): add a ~I escape option that shows information about the
current SSH connection.
* sshd(8): add 'invaliduser' penalty to PerSourcePenalties, which is
applied to login attempts for usernames that do not match real
accounts. Defaults to 5s to match 'authfail' but allows
administrators to block such attempts for longer if desired.
* Support the ed25519 signature scheme via libcrypto.
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D56999
Full release notes are available at
https://www.openssh.com/txt/release-10.1
Selected highlights from the release notes:
Potentially-incompatible changes
* ssh(1): add a warning when the connection negotiates a non-post
quantum key agreement algorithm.
* ssh(1), sshd(8): major changes to handling of DSCP marking/IPQoS
* ssh(1), sshd(8): deprecate support for IPv4 type-of-service (ToS)
keywords in the IPQoS configuration directive.
* ssh-add(1): when adding certificates to an agent, set the expiry
to the certificate expiry time plus a short (5 min) grace period.
* ssh-agent(1), sshd(8): move agent listener sockets from /tmp to
under ~/.ssh/agent for both ssh-agent(1) and forwarded sockets
in sshd(8).
Security
* ssh(1): disallow control characters in usernames passed via the
commandline or expanded using %-sequences from the configuration
file, and disallow \0 characters in ssh:// URIs.
New features
* ssh(1), sshd(8): add SIGINFO handlers to log active channel and
session information.
Sponsored by: The FreeBSD Foundation
Migrate to OpenSSL 3.5 in advance of FreeBSD 15.0. OpenSSL 3.0 will be
EOL after 2026-09-07.
Approved by: philip (mentor)
Sponsored by: Alpha-Omega Beach Cleaning Project
Sponsored by: The FreeBSD Foundation
Differential revision: https://reviews.freebsd.org/D51613
Commit 1cbb58886a (shipped in 12.0.0) removed all lint infrastructure.
A bunch of NO_LINT definitions remained (perhaps as a bootstrapping
measture). Remove them.
Reviewed by: emaste
Differential Revision: https://reviews.freebsd.org/D50704
sshkey.c references sshsk_sign(), which is defined in ${SKSRCS}.
Due to how FreeBSD builds libssh, or put differently, due to upstream
not building a shared libssh.so, we need to partially revert
65d8491719 ("secure: Adapt Makefile to ssh-sk-client everywhere"), and
add ${SKSRCS} back, to avoid linking problems, especially when building
with GCC:
/usr/local/bin/ld:
/usr/obj/usr/src/amd64.amd64/secure/lib/libssh/libprivatessh.so:
undefined reference to `sshsk_sign'
collect2: error: ld returned 1 exit status`
Put the sources in a separate line, to maintain line-by-line
compatibility with upstream Makefile.in
PR: 286580
Reviewed by: emaste
Approved by: emaste (mentor)
Fixes: 65d8491719 ("secure: Adapt Makefile to ssh-sk-client everywhere")
Differential Revision: https://reviews.freebsd.org/D50020
Upstream commit 7b47b40b1 ("adapt Makefile to ssh-sk-client everywhere")
adapted the Makefiles to ssh-sk-client. Do the same here.
Reviewed by: emaste
Approved by: emaste (mentor)
Differential Revision: https://reviews.freebsd.org/D49795
SRCS entries are kept in the same order and with the same line breaks as
upstream, to make comparison easier.
No functional change intended.
Reviewed by: emaste
Approved by: emaste (mentor)
Differential Revision: https://reviews.freebsd.org/D49793
Commit 9d63429fa1 ("ssh: move common Makefile boilerplate to a new
ssh.mk") introduced ssh.mk for common OpenSSH paths and flags, as part
of enabling FIDO/U2F. Move duplicated MK_LDNS and MK_TCP_WRAPPERS
handling there.
Reviewed by: kevans
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D31896
Centralize optional krb5_config.h handling in ssh.mk. Do not add
headers (that are committed to the src tree) to SRCS as there is no
need.
Reviewed by: imp, jlduran, kevans (all earlier)
MFC after: 1 month
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D34409
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
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
It is used only by scp and sftp, and already included directly in their
Makefiles. It does not belong in libssh.
Fixes: d8b043c8d4 ("Update for 3.6.1p1; also remove Kerberos IV shims.")
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D48871
This release fixes a number of security bugs and has minor new
features and bug fixes. Security fixes, from the release notes
(https://www.openssh.com/txt/release-9.3):
This release contains fixes for a security problem and a memory
safety problem. The memory safety problem is not believed to be
exploitable, but we report most network-reachable memory faults as
security bugs.
* ssh-add(1): when adding smartcard keys to ssh-agent(1) with the
per-hop destination constraints (ssh-add -h ...) added in OpenSSH
8.9, a logic error prevented the constraints from being
communicated to the agent. This resulted in the keys being added
without constraints. The common cases of non-smartcard keys and
keys without destination constraints are unaffected. This problem
was reported by Luci Stanescu.
* ssh(1): Portable OpenSSH provides an implementation of the
getrrsetbyname(3) function if the standard library does not
provide it, for use by the VerifyHostKeyDNS feature. A
specifically crafted DNS response could cause this function to
perform an out-of-bounds read of adjacent stack data, but this
condition does not appear to be exploitable beyond denial-of-
service to the ssh(1) client.
The getrrsetbyname(3) replacement is only included if the system's
standard library lacks this function and portable OpenSSH was not
compiled with the ldns library (--with-ldns). getrrsetbyname(3) is
only invoked if using VerifyHostKeyDNS to fetch SSHFP records. This
problem was found by the Coverity static analyzer.
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 "[email protected]" extension
request that allows the client to obtain user/group names that
correspond to a set of uids/gids.
* sftp(1): use "[email protected]" 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 "[email protected]", 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
This moves SSHDIR and ssh_namespace.h handling to a common location,
and will simplify future work such as adding U2F support (D32509).
Reviewed by: kevans
MFC after: 1 week
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D32808
Link against the ssh-sk-helper client rather than the sk internal
implementation.
PR: 258384
Tested by: madpilot
Fixes: f448c3ed4a ("openssh: Add new source files to libssl")
Fixes: 19261079b7 ("openssh: update to OpenSSH v8.7p1")
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D32529
Add some new OpenSSH v8.7p1 source files to the ones being used to
build libssl to avoid missing symbols.
PR: 258384
Fixes: 19261079b7 ("openssh: update to OpenSSH v8.7p1")
Approved by: kevans (src)
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
Literal references to /usr/local exist in a large number of files in
the FreeBSD base system. Many are in contributed software, in configuration
files, or in the documentation, but 19 uses have been identified in C
source files or headers outside the contrib and sys/contrib directories.
This commit makes it possible to set _PATH_LOCALBASE in paths.h to use
a different prefix for locally installed software.
In order to avoid changes to openssh source files, LOCALBASE is passed to
the build via Makefiles under src/secure. While _PATH_LOCALBASE could have
been used here, there is precedent in the construction of the path used to
a xauth program which depends on the LOCALBASE value passed on the compiler
command line to select a non-default directory.
This could be changed in a later commit to make the openssh build
consistently use _PATH_LOCALBASE. It is considered out-of-scope for this
commit.
Reviewed by: imp
MFC after: 1 month
Differential Revision: https://reviews.freebsd.org/D26942
Update a bunch of Makefile.depend files as
a result of adding Makefile.depend.options files
Reviewed by: bdrewery
MFC after: 1 week
Sponsored by: Juniper Networks
Differential Revision: https://reviews.freebsd.org/D22494
Compatibility with existing OpenSSL versions is maintained.
Upstream commits:
482d23bcac upstream: hold our collective noses and use the openssl-1.1.x
48f54b9d12 adapt -portable to OpenSSL 1.1x API
86e0a9f3d2 upstream: use only openssl-1.1.x API here too
a3fd8074e2 upstream: missed a bit of openssl-1.0.x API in this unittest
cce8cbe0ed Fix openssl-1.1 fallout for --without-openssl.
Trivial conflicts in sshkey.c and test_sshkey.c were resolved.
Connect libressl-api-compat.c to the build, and regenerate config.h
Reviewed by: des
Approved by: re (rgrimes)
MFC after: 2 seeks
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D17444
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.
MK_KERBEROS_SUPPORT != no
This fixes the odd case where someone specified MK_GSSAPI=no and
MK_KERBEROS_SUPPORT=yes (which admittedly, probably doesn't make sense,
but the build system doesn't prevent this case today, and it didn't when
I filed the bug back in 2011 either).
MFC after: 2 weeks
PR: 159745
bsd.lib.mk and bsd.prog.mk already depend all objs on headers in SRCS if
there is not yet a depend file. The headers in SRCS are never built or
installed. After 'make depend' the header was already added as a proper
dependency on the objects where needed.
MFC after: 2 weeks
Sponsored by: EMC / Isilon Storage Division
This both avoids some dependencies on xinstall.host and allows
bootstrapping on older releases to work due to lack of at least 'install -l'
support.
Sponsored by: EMC / Isilon Storage Division
Ed Maste