In ssh, when an agent fails to return a RSA-SHA2 signature when
requested and falls back to RSA-SHA1 instead, retry the signature to
ensure that the public key algorithm sent in the SSH_MSG_USERAUTH
matches the one in the signature itself.
In sshd, strictly enforce that the public key algorithm sent in the
SSH_MSG_USERAUTH message matches what appears in the signature.
Make the sshd_config PubkeyAcceptedKeyTypes and
HostbasedAcceptedKeyTypes options control accepted signature algorithms
(previously they selected supported key types). This allows these
options to ban RSA-SHA1 in favour of RSA-SHA2.
Add new signature algorithms "rsa-sha2-256-cert-v01@openssh.com" and
"rsa-sha2-512-cert-v01@openssh.com" to force use of RSA-SHA2 signatures
with certificate keys.
feedback and ok markus@
OpenBSD-Commit-ID: c6e9f6d45eed8962ad502d315d7eaef32c419dde
environment variables for the remote session (subject to the server accepting
them)
refactor SendEnv to remove the arbitrary limit of variable names.
ok markus@
OpenBSD-Commit-ID: cfbb00d9b0e10c1ffff1d83424351fd961d1f2be
username is available currently. In the client this is via %i, in the server
%U (since %i was already used in the client in some places for this, but used
for something different in the server); bz#2870, ok dtucker@
OpenBSD-Commit-ID: c7e912b0213713316cb55db194b3a6415b3d4b95
interactive and CS1 for bulk
AF21 was selected as this is the highest priority within the low-latency
service class (and it is higher than what we have today). SSH is elastic
and time-sensitive data, where a user is waiting for a response via the
network in order to continue with a task at hand. As such, these flows
should be considered foreground traffic, with delays or drops to such
traffic directly impacting user-productivity.
For bulk SSH traffic, the CS1 "Lower Effort" marker was chosen to enable
networks implementing a scavanger/lower-than-best effort class to
discriminate scp(1) below normal activities, such as web surfing. In
general this type of bulk SSH traffic is a background activity.
An advantage of using "AF21" for interactive SSH and "CS1" for bulk SSH
is that they are recognisable values on all common platforms (IANA
https://www.iana.org/assignments/dscp-registry/dscp-registry.xml), and
for AF21 specifically a definition of the intended behavior exists
https://tools.ietf.org/html/rfc4594#section-4.7 in addition to the definition
of the Assured Forwarding PHB group https://tools.ietf.org/html/rfc2597, and
for CS1 (Lower Effort) there is https://tools.ietf.org/html/rfc3662
The first three bits of "AF21" map to the equivalent IEEEE 802.1D PCP, IEEE
802.11e, MPLS EXP/CoS and IP Precedence value of 2 (also known as "Immediate",
or "AC_BE"), and CS1's first 3 bits map to IEEEE 802.1D PCP, IEEE 802.11e,
MPLS/CoS and IP Precedence value 1 ("Background" or "AC_BK").
OK deraadt@, "no objection" djm@
OpenBSD-Commit-ID: d11d2a4484f461524ef0c20870523dfcdeb52181
command-line argument to ssh(1) that directs it to bind its outgoing
connection to the address of the specified network interface.
BindInterface prefers to use addresses that aren't loopback or link-
local, but will fall back to those if no other addresses of the
required family are available on that interface.
Based on patch by Mike Manning in bz#2820, ok dtucker@
OpenBSD-Commit-ID: c5064d285c2851f773dd736a2c342aa384fbf713
diffie-hellman-group14-sha256
diffie-hellman-group16-sha512
diffie-hellman-group18-sha512
From Jakub Jelen via bz#2826
OpenBSD-Commit-ID: 51bf769f06e55447f4bfa7306949e62d2401907a
Mention ServerAliveTimeout in context of TCPKeepAlives;
prompted by Christoph Anton Mitterer via github
OpenBSD-Commit-ID: f0cf1b5bd3f1fbf41d71c88d75d93afc1c880ca2
Shorter, more accurate explanation of
NoHostAuthenticationForLocalhost without the confusing example. Prompted by
Christoph Anton Mitterer via github and bz#2293.
OpenBSD-Commit-ID: 19dc96bea25b80d78d416b581fb8506f1e7b76df
Replace "trojan horse" with the correct term (MITM).
From maikel at predikkta.com via bz#2822, ok markus@
OpenBSD-Commit-ID: e86ac64c512057c89edfadb43302ac0aa81a6c53
Expose devices allocated for tun/tap forwarding.
At the client, the device may be obtained from a new %T expansion
for LocalCommand.
At the server, the allocated devices will be listed in a
SSH_TUNNEL variable exposed to the environment of any user sessions
started after the tunnel forwarding was established.
ok markus
Upstream-ID: e61e53f8ae80566e9ddc0d67a5df5bdf2f3c9f9e
Add URI support to ssh, sftp and scp. For example
ssh://user@host or sftp://user@host/path. The connection parameters
described in draft-ietf-secsh-scp-sftp-ssh-uri-04 are not implemented since
the ssh fingerprint format in the draft uses md5 with no way to specify the
hash function type. OK djm@
Upstream-ID: 4ba3768b662d6722de59e6ecb00abf2d4bf9cacc
In the description of pattern-lists, clarify negated
matches by explicitly stating that a negated match will never yield a
positive result, and that at least one positive term in the pattern-list must
match. bz#1918
Upstream-ID: 652d2f9d993f158fc5f83cef4a95cd9d95ae6a14
Add 'reverse' dynamic forwarding which combines dynamic
forwarding (-D) with remote forwarding (-R) where the remote-forwarded port
expects SOCKS-requests.
The SSH server code is unchanged and the parsing happens at the SSH
clients side. Thus the full SOCKS-request is sent over the forwarded
channel and the client parses c->output. Parsing happens in
channel_before_prepare_select(), _before_ the select bitmask is
computed in the pre[] handlers, but after network input processing
in the post[] handlers.
help and ok djm@
Upstream-ID: aa25a6a3851064f34fe719e0bf15656ad5a64b89
Expand ssh_config's StrictModes option with two new
settings:
StrictModes=accept-new will automatically accept hitherto-unseen keys
but will refuse connections for changed or invalid hostkeys.
StrictModes=off is the same as StrictModes=no
Motivation:
StrictModes=no combines two behaviours for host key processing:
automatically learning new hostkeys and continuing to connect to hosts
with invalid/changed hostkeys. The latter behaviour is quite dangerous
since it removes most of the protections the SSH protocol is supposed to
provide.
Quite a few users want to automatically learn hostkeys however, so
this makes that feature available with less danger.
At some point in the future, StrictModes=no will change to be a synonym
for accept-new, with its current behaviour remaining available via
StrictModes=off.
bz#2400, suggested by Michael Samuel; ok markus
Upstream-ID: 0f55502bf75fc93a74fb9853264a8276b9680b64
Allow IPQoS=none in ssh/sshd to not set an explicit
ToS/DSCP value and just use the operating system default; ok dtucker@
Upstream-ID: 77906ff8c7b660b02ba7cb1e47b17d66f54f1f7e
man pages with pseudo synopses which list filenames end
up creating very ugly output in man -k; after some discussion with ingo, we
feel the simplest fix is to remove such SYNOPSIS sections: the info is hardly
helpful at page top, is contained already in FILES, and there are
sufficiently few that just zapping them is simple;
ok schwarze, who also helpfully ran things through a build to check
output;
Upstream-ID: 3e211b99457e2f4c925c5927d608e6f97431336c
use HostKeyAlias if specified instead of hostname for
matching host certificate principal names; bz#2728; ok dtucker@
Upstream-ID: dc2e11c83ae9201bbe74872a0c895ae9725536dd
Add RemoteCommand option to specify a command in the
ssh config file instead of giving it on the client's command line. This
command will be executed on the remote host. The feature allows to automate
tasks using ssh config. OK markus@
Upstream-ID: 5d982fc17adea373a9c68cae1021ce0a0904a5ee
As promised in last release announcement: remove
support for Blowfish, RC4 and CAST ciphers. ok markus@ deraadt@
Upstream-ID: 21f8facdba3fd8da248df6417000867cec6ba222
Add SyslogFacility option to ssh(1) matching the
equivalent option in sshd(8). bz#2705, patch from erahn at arista.com, ok
djm@
Upstream-ID: d5115c2c0193ceb056ed857813b2a7222abda9ed
support =- for removing methods from algorithms lists,
e.g. Ciphers=-*cbc; suggested by Cristian Ionescu-Idbohrn in bz#2671 "I like
it" markus@
Upstream-ID: c78c38f9f81a963b33d0eade559f6048add24a6d
remove 3des-cbc from the client's default proposal;
64-bit block ciphers are not safe in 2016 and we don't want to wait until
attacks like sweet32 are extended to SSH.
As 3des-cbc was the only mandatory cipher in the SSH RFCs, this may
cause problems connecting to older devices using the defaults, but
it's highly likely that such devices already need explicit
configuration for KEX and hostkeys anyway.
ok deraadt, markus, dtucker
Upstream-ID: a505dfe65c6733af0f751b64cbc4bb7e0761bc2f
reverse the order in which -J/JumpHost proxies are visited to
be more intuitive and document
reported by and manpage bits naddy@
Upstream-ID: 3a68fd6a841fd6cf8cedf6552a9607ba99df179a
Add a ProxyJump ssh_config(5) option and corresponding -J
ssh(1) command-line flag to allow simplified indirection through a SSH
bastion or "jump host".
These options construct a proxy command that connects to the
specified jump host(s) (more than one may be specified) and uses
port-forwarding to establish a connection to the next destination.
This codifies the safest way of indirecting connections through SSH
servers and makes it easy to use.
ok markus@
Upstream-ID: fa899cb8b26d889da8f142eb9774c1ea36b04397
