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
never write a name with bad characters to a known_hosts file.
replace recently-added valid_domain() check for hostnames going to
known_hosts with a more relaxed check for bad characters.
Obtained from: OpenSSH-portable commit 445363433ba2
Obtained from: OpenSSH-portable commit 3cae9f92a318
Sponsored by: The FreeBSD Foundation
its first argument unless it was one of the special keywords "any" or
"none".
Obtained from: OpenSSH-portable commit b3daa8dc5823
Sponsored by: The FreeBSD Foundation
ssh_config and ssh_config.5 no longer contain the VersionAddendum,
so remove instructions to update these files.
Fixes: bffe60ead0 ("ssh: retire client VersionAddendum")
Sponsored By: The FreeBSD Foundation
We documented "[Use]PrivilegeSeparation defaults to sandbox" as one of
our modifications to ssh's server-side defaults, but this is not (any
longer) a difference from upstream.
Sponsored by: The FreeBSD Foundation
Old versions of FreeBSD do not support using id 0 to refer to the
current pid for procctl, so pass getpid() explicitly.
Although this is not required in current FreeBSD branches I am merging
it to reduce differences with upstream.
Obtained from: OpenSSH commit 0f7e1eba5525
This appeared to be a copy-paste error from the "from" time case above.
Reported by: Coverity Scan
CID: 1500407
Reviewed by: markj
MFC after: 3 days
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D37252
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
We no longer use the pre- and post-merge scripts to strip/add RCS tags.
The tags have been removed from main, but persist on older branches.
While here renumber the steps in the update documentation using a more
conventional scheme.
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D36904
Nanobsd included copies of ssh_config and sshd_config. The former is
identical to the one provided by the base system, and the latter is
identical except for PermitRootLogin, which is updated by nanobsd's
cust_allow_ssh_root anyhow. Remove nanobsd's copies and use the
existing base system ones.
Reported by: Jose Luis Duran <jlduran@gmail.com> in D34937
Reviewed by: Jose Luis Duran <jlduran@gmail.com>, imp
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D36933
Rename "HPN" to more general "Retired patches." We handle two now-
removed patches the same way: to avoid breaking existing configurations
we accept, but ignore, the option.
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
Passwords may be accepted by both the PasswordAuthentication and
KbdInteractiveAuthentication authentication schemes. Add a reference to
the latter in the description/comment for PasswordAuthentication, as it
otherwise may seem that "PasswordAuthentication no" implies passwords
will be disallowed.
This situation should be clarified with more extensive documentation on
the authentication schemes and configuration options, but that should be
done in coordination with upstream OpenSSH. This is a minimal change
that will hopefully clarify the situation without requiring an extensive
local patch set.
PR: 263045
Reviewed by: manu (earlier version)
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D35272
The PermitRootLogin option "prohibit-password" was added as a synonym
for "without-password" in 2015. Then in 2017 these were swapped:
"prohibit-password" became the canonical option and "without-password"
became a deprecated synonym (in OpenSSH commit 071325f458).
The UsePAM description in sshd_config still mentioned
"without-password." Update it to match the new canonical option.
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
With the upgrade to OpenSSH 6.7p1 in commit a0ee8cc636 we replaced
WITH_OPENSSL ifdefs with an OPENSSL_VERSION macro, later changing it
to OPENSSL_VERSION_STRING.
A few years later OpenSSH made an equivalent change (with a different
macro name), in commit 4d94b031ff88. Switch to the macro name they
chose.
MFC after: 1 week
Sponsored by: The FreeBSD Foundation
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
We already set it earlier in do_setup_env().
Fixes: 19261079b7 ("openssh: update to OpenSSH v8.7p1")
MFC after: 1 week
Sponsored by: The FreeBSD Foundation
upstream: clear io_want/io_ready flags at start of poll() cycle;
avoids plausible spin during rekeying if channel io_want flags are reused
across cycles. ok markus@ deraadt@
From upstream release notes https://www.openssh.com/txt/release-9.0
This release switches scp(1) from using the legacy scp/rcp protocol
to using the SFTP protocol 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.
This creates one area of potential incompatibility: scp(1) when using
the SFTP protocol no longer requires this finicky and brittle quoting,
and attempts to use it may cause transfers to fail. We consider the
removal of the need for double-quoting shell characters in file names
to be a benefit and do not intend to introduce bug-compatibility for
legacy scp/rcp in scp(1) when using the SFTP protocol.
Another area of potential incompatibility relates to the use of remote
paths relative to other user's home directories, for example -
"scp host:~user/file /tmp". The SFTP protocol has no native way to
expand a ~user path. However, sftp-server(8) in OpenSSH 8.7 and later
support a protocol extension "expand-path@openssh.com" to support
this.
In case of incompatibility, the scp(1) client may be instructed to use
the legacy scp/rcp using the -O flag.
Relnotes: Yes
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 8.8p1 removed RSA/SHA-1 signatures by default, but failed to
update sshd_config(5). It was updated upstream after the release in
b711bc01a7ec and da4035523406.
Fixes: 8c22023ca5 ("ssh: disable RSA/SHA-1 signatures")
Sponsored by: The FreeBSD Foundation
Specify -lprivatecbor and -lprivatefido2 in OpenSSH's configure.ac, and
pass -I paths to libcbor and libfido2's contrib src location.
MFC after: 3 days
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D34440
An upcoming OpenSSH update has multiple config.h settings that change
depending on whether builtin security key support is enabled. Prepare
for this by moving ENABLE_SK_INTERNAL to a new sk_config.h header
(similar to the approach used for optional krb5 support) and optionally
including that, instead of defining the macro directly from CFLAGS.
Reviewed by: kevans
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D34407
The option is security-key-builtin not security-key-internal. There is
no change to the generated config.h because the option defaults off
anyway.
MFC after: 3 days
Fixes: 87152f3405 ("ssh: disble internal security key...")
Sponsored by: The FreeBSD Foundation
Because it appears `git push --follow-tags` may push extra, undesired
tags document both techniques (pushing the specific vendor/openssh/X.YpZ
tag and pushing all with --follow-tags, using --dry-run first).
Discussed with: imp, lwhsu
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D33605
As of f833ab9dd1 procctl(2) allows idtype P_PID with id = 0 as a
shortcut for the calling process ID. The shortcut also bypasses the
p_cansee / p_candebug test (since the process is able to act on itself.)
At present if the security.bsd.unprivileged_proc_debug sysctl is 0 then
procctl(P_PID, getpid(), ... for a process to act on itself will fail,
but procctl(P_PID, 0, ... will succeed. This should likely be addressed
with a kernel change.
In any case the id = 0 shortcut is a tiny optimization for a process to
act on itself and allows the self-procctl to succeed, so use it in ssh.
Reported by: Shawn Webb
Reviewed by: kib
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D33970
OpenSSH has dropped libwrap support in OpenSSH 6.7p in 2014
(f2719b7c in github.com/openssh/openssh-portable) and we
maintain the patch ourselves since 2016 (a0ee8cc636).
Over the years, the libwrap support has deteriotated and probably
that was reason for removal upstream. Original idea of libwrap was
to drop illegitimate connection as soon as possible, but over the
years the code was pushed further down and down and ended in the
forked client connection handler.
The negative effects of late dropping is increasing attack surface
for hosts that are to be dropped anyway. Apart from hypothetical
future vulnerabilities in connection handling, today a malicious
host listed in /etc/hosts.allow still can trigger sshd to enter
connection throttling mode, which is enabled by default (see
MaxStartups in sshd_config(5)), effectively casting DoS attack.
Note that on OpenBSD this attack isn't possible, since they enable
MaxStartups together with UseBlacklist.
A only negative effect from early drop, that I can imagine, is that
now main listener parses file in /etc, and if our root filesystems
goes bad, it would get stuck. But unlikely you'd be able to login
in that case anyway.
Implementation details:
- For brevity we reuse the same struct request_info. This isn't
a documented feature of libwrap, but code review, viewing data
in a debugger and real life testing shows that if we clear
RQ_CLIENT_NAME and RQ_CLIENT_ADDR every time, it works as intended.
- We set SO_LINGER on the socket to force immediate connection reset.
- We log message exactly as libwrap's refuse() would do.
Differential revision: https://reviews.freebsd.org/D33044
From OpenSSH 8.8p1's release notes:
---
Potentially-incompatible changes
================================
This release disables RSA signatures using the SHA-1 hash algorithm
by default. This change has been made as the SHA-1 hash algorithm is
cryptographically broken, and it is possible to create chosen-prefix
hash collisions for <USD$50K [1]
For most users, this change should be invisible and there is
no need to replace ssh-rsa keys. OpenSSH has supported RFC8332
RSA/SHA-256/512 signatures since release 7.2 and existing ssh-rsa keys
will automatically use the stronger algorithm where possible.
Incompatibility is more likely when connecting to older SSH
implementations that have not been upgraded or have not closely tracked
improvements in the SSH protocol. For these cases, it may be necessary
to selectively re-enable RSA/SHA1 to allow connection and/or user
authentication via the HostkeyAlgorithms and PubkeyAcceptedAlgorithms
options. For example, the following stanza in ~/.ssh/config will enable
RSA/SHA1 for host and user authentication for a single destination host:
Host old-host
HostkeyAlgorithms +ssh-rsa
PubkeyAcceptedAlgorithms +ssh-rsa
We recommend enabling RSA/SHA1 only as a stopgap measure until legacy
implementations can be upgraded or reconfigured with another key type
(such as ECDSA or Ed25519).
[1] "SHA-1 is a Shambles: First Chosen-Prefix Collision on SHA-1 and
Application to the PGP Web of Trust" Leurent, G and Peyrin, T
(2020) https://eprint.iacr.org/2020/014.pdf
---
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
These files were intended to track version and perhaps maintainership
information for contrib software. However, they were never used beyond
bzip2, netcat, and OpenSSH, and generally haven't been kept up to date
recently (my OpenSSH 8.7p1 update notwithstanding). Just remove them to
avoid having confusing or outdated information.
Suggested by: des
MFC after: 1 week
Sponsored by: The FreeBSD Foundation
Description of FIDO/U2F support (from OpenSSH 8.2 release notes,
https://www.openssh.com/txt/release-8.2):
This release adds support for FIDO/U2F hardware authenticators to
OpenSSH. U2F/FIDO are open standards for inexpensive two-factor
authentication hardware that are widely used for website
authentication. In OpenSSH FIDO devices are supported by new public
key types "ecdsa-sk" and "ed25519-sk", along with corresponding
certificate types.
ssh-keygen(1) may be used to generate a FIDO token-backed key, after
which they may be used much like any other key type supported by
OpenSSH, so long as the hardware token is attached when the keys are
used. FIDO tokens also generally require the user explicitly
authorise operations by touching or tapping them.
Generating a FIDO key requires the token be attached, and will
usually require the user tap the token to confirm the operation:
$ ssh-keygen -t ecdsa-sk -f ~/.ssh/id_ecdsa_sk
Generating public/private ecdsa-sk key pair.
You may need to touch your security key to authorize key generation.
Enter file in which to save the key (/home/djm/.ssh/id_ecdsa_sk):
Enter passphrase (empty for no passphrase):
Enter same passphrase again:
Your identification has been saved in /home/djm/.ssh/id_ecdsa_sk
Your public key has been saved in /home/djm/.ssh/id_ecdsa_sk.pub
This will yield a public and private key-pair. The private key file
should be useless to an attacker who does not have access to the
physical token. After generation, this key may be used like any
other supported key in OpenSSH and may be listed in authorized_keys,
added to ssh-agent(1), etc. The only additional stipulation is that
the FIDO token that the key belongs to must be attached when the key
is used.
To enable FIDO/U2F support, this change regenerates ssh_namespace.h,
adds ssh-sk-helper, and sets ENABLE_SK_INTERNAL (unless building
WITHOUT_USB).
devd integration is not included in this change, and is under
investigation for the base system. In the interim the security/u2f-devd
port can be installed to provide appropriate devd rules.
Reviewed by: delphij, kevans
Relnotes: Yes
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D32509