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
We want to set ENABLE_SK_INTERNAL only when building with USB support.
We'll leave it off in config.h and enble it via our bespoke build's
Makefile.inc.
Sponsored by: The FreeBSD Foundation
Two local changes were committed upstream and are present in OpenSSH
8.7p1. Remove references from FREEBSD-upgrade now that we have updated
to that version.
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
/usr/include/gssapi.h claims that it is deprecated, and gssapi/gssapi.h
should be used instead. So, test HAVE_GSSAPI_GSSAPI_H first falling
back to HAVE_GSSAPI_H.
This will be submitted upstream.
Fixes: 6eac665c81 ("openssh: diff reduction against...")
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D31810
For some reason poly64 was omitted when this file was last generated
(perhaps it was inlined by the Clang version then in use).
MFC after: 1 week
Sponsored by: The FreeBSD Foundation
Tools like Phabricator use the @generated tag to identify files that
may be excluded from review by default.
MFC after: 1 week
Sponsored by: The FreeBSD Foundation
Since config.h was last regenerated FreeBSD has added (a stub) libdl,
and has removed sys/dir.h. Regenerate config.h to avoid spurious
additional changes when OpenSSH is next updated.
There should be no issue if this change is MFC'd, but I don't plan to do
so. Although configure checks for libdl HAVE_LIBDL isn't even used, and
sys/dir.h was non-functional before being removed. The state of these
two config.h settings should make no difference in the built OpenSSH.
Sponsored by: The FreeBSD Foundation
We define LIBWRAP at build time in secure/usr.sbin/sshd/Makefile if
WITH_TCPWRAPPERS is in effect, so it should not be set in config.h.
MFC after: 1 week
Sponsored by: The FreeBSD Foundation
freebsd-configure.sh runs configure twice, --with-kerberos5 and
--without-kerberos5, in order to build a config.h that defaults to
kerberos5 disabled, and a small config file that represents the
differences.
Rename config.h.orig to config.h.kerberos5 to clarify the intent of this
script.
MFC after: 1 week
Sponsored by: The FreeBSD Foundation
Login class-based restrictions were introduced in 5b400a39b8. The
code was adapted for sshd's Capsicum sandbox and received many changes
over time, including at least fc3c19a9fc, bd393de91c, and
e8c56fba29.
During an attempt to upstream the work a much simpler approach was
suggested. Adopt it now in the in-tree OpenSSH to reduce conflicts with
future updates.
Submitted by: Yuchiro Naito (against OpenSSH-portable on GitHub)
Obtained from: https://github.com/openssh/openssh-portable/pull/262
Reviewed by: allanjude, kevans
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D31760
This was introduced in 8998619212, and left behind when the hpn-ssh
patches were removed in 60c59fad88. Although Being able to log
SO_RCVBUF in debug mode might have some small value on its own, it's
not worth carrying an extra diff against upstream.
Reviewed by: kevans
MFC after: 3 days
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D28610
This was introduced in 03f6c5cd93, which added use of
sysctl net.inet.ip.portrange.reservedhigh instead of IPPORT_RESERVED,
but it appears the rest of that change was lost in some subsequent
update.
The change should probably be restored, but until then there is no
reason to leave an unused variable around.
MFC after: 3 days
Sponsored by: The FreeBSD Foundation
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
blacklistd has been renamed to blocklistd upstream, and a future
import into FreeBSD will follow that change. Support the new name
as an alias in config files.
Reviewed by: bz, delphij
MFC after: 1 week
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D25865
