used one shared table and overflow policy for IPv4 and IPv6 addresses, now it
will use separate tables and optionally different overflow policies.
This prevents misbehaviour from IPv6 addresses (which are vastly easier
to obtain many of) from affecting IPv4 connections and may allow for
stricter overflow policies.
ok deraadt@
OpenBSD-Commit-ID: 12637ed0aa4d5f1f3e702da42ea967cbd8bfdfd9
problematic client behaviours, controlled by two new sshd_config(5) options:
PerSourcePenalties and PerSourcePenaltyExemptList.
When PerSourcePenalties are enabled, sshd(8) will monitor the exit
status of its child pre-auth session processes. Through the exit
status, it can observe situations where the session did not
authenticate as expected. These conditions include when the client
repeatedly attempted authentication unsucessfully (possibly indicating
an attack against one or more accounts, e.g. password guessing), or
when client behaviour caused sshd to crash (possibly indicating
attempts to exploit sshd).
When such a condition is observed, sshd will record a penalty of some
duration (e.g. 30 seconds) against the client's address. If this time
is above a minimum threshold specified by the PerSourcePenalties, then
connections from the client address will be refused (along with any
others in the same PerSourceNetBlockSize CIDR range).
Repeated offenses by the same client address will accrue greater
penalties, up to a configurable maximum. A PerSourcePenaltyExemptList
option allows certain address ranges to be exempt from all penalties.
We hope these options will make it significantly more difficult for
attackers to find accounts with weak/guessable passwords or exploit
bugs in sshd(8) itself.
PerSourcePenalties is off by default, but we expect to enable it
automatically in the near future.
much feedback markus@ and others, ok markus@
OpenBSD-Commit-ID: 89ded70eccb2b4926ef0366a4d58a693de366cca
that watches all open channels and will close all open channels if there is
no traffic on any of them for the specified interval. This is in addition to
the existing per-channel timeouts added a few releases ago.
This supports use-cases like having a session + x11 forwarding channel
open where one may be idle for an extended period but the other is
actively used. The global timeout would allow closing both channels when
both have been idle for too long.
ok dtucker@
OpenBSD-Commit-ID: 0054157d24d2eaa5dc1a9a9859afefc13d1d7eb3
AuthorizedKeysCommand accept the %D (routing domain) and a new %C (connection
address/port 4-tuple) as expansion sequences; ok markus
OpenBSD-Commit-ID: ee9a48bf1a74c4ace71b69de69cfdaa2a7388565
are exceptions at the start of the manpage and label some of them in the
option description.
OpenBSD-Commit-ID: 3b74728446fa6fc8742769eeb8c3674e233e84c4
client connections that have no open channels for some length of time. This
complements the recently-added ChannelTimeout option that terminates inactive
channels after a timeout.
ok markus@
OpenBSD-Commit-ID: ca983be74c0350364c11f8ba3bd692f6f24f5da9
This adds a sshd_config ChannelTimeouts directive that 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.
Note: this only affects channels over an opened SSH connection and not
the connection itself. Most clients close the connection when their channels
go away, with a notable exception being ssh(1) in multiplexing mode.
ok markus dtucker
OpenBSD-Commit-ID: ae8bba3ed9d9f95ff2e2dc8dcadfa36b48e6c0b8
beneath this limit will be ignored for user and host-based authentication.
Feedback deraadt@ ok markus@
OpenBSD-Commit-ID: 187931dfc19d51873df5930a04f2d972adf1f7f1
ECDH/x25519 + Streamlined NTRU Prime post-quantum KEX to the default
KEXAlgorithms list (after the ECDH methods but before the prime-group DH
ones).
ok markus@
OpenBSD-Commit-ID: 22b77e27a04e497a10e22f138107579652854210
favour of KbdInteractiveAuthentication. The former is what was in SSHv1, the
latter is what is in SSHv2 (RFC4256) and they were treated as somewhat but
not entirely equivalent. We retain the old name as deprecated alias so
config files continue to work and a reference in the man page for people
looking for it.
Prompted by bz#3303 which pointed out the discrepancy between the two
when used with Match. Man page help & ok jmc@, with & ok djm@
OpenBSD-Commit-ID: 2c1bff8e5c9852cfcdab1f3ea94dfef5a22f3b7e
location of the "moduli" file containing the groups for DH-GEX. This will
allow us to run tests against arbitrary moduli files without having to
install them. ok djm@
OpenBSD-Commit-ID: 8df99d60b14ecaaa28f3469d01fc7f56bff49f66
HostbasedAcceptedKeyTypes (sshd) to HostbasedAcceptedAlgorithms, which more
accurately reflects its effect. This matches a previous change to
PubkeyAcceptedAlgorithms. The previous names are retained as aliases. ok
djm@
OpenBSD-Commit-ID: 49451c382adc6e69d3fa0e0663eeef2daa4b199e
PubkeyAcceptedAlgorithms. While the two were originally equivalent, this
actually specifies the signature algorithms that are accepted. Some key
types (eg RSA) can be used by multiple algorithms (eg ssh-rsa, rsa-sha2-512)
so the old name is becoming increasingly misleading. The old name is
retained as an alias. Prompted by bz#3253, help & ok djm@, man page help jmc@
OpenBSD-Commit-ID: 0346b2f73f54c43d4e001089759d149bfe402ca5
options which provide more fine grained MaxStartups limits. Man page help
jmc@, feedback & ok djm@
OpenBSD-Commit-ID: e2f68664e3d02c0895b35aa751c48a2af622047b
exchange method based on Streamlined NTRU Prime (coupled with X25519).
The previous sntrup4591761x25519-sha512@tinyssh.org method is
replaced with sntrup761x25519-sha512@openssh.com. Per the authors,
sntrup4591761 was replaced almost two years ago by sntrup761.
The sntrup761 implementaion, like sntrup4591761 before it, is public
domain code extracted from the SUPERCOP cryptography benchmark
suite (https://bench.cr.yp.to/supercop.html).
Thanks for Daniel J Bernstein for guidance on algorithm selection.
Patch from Tobias Heider; feedback & ok markus@ and myself
(note this both the updated method and the one that it replaced are
disabled by default)
OpenBSD-Commit-ID: 2bf582b772d81ee24e911bb6f4b2aecfd39338ae
naddy@openbsd.org
djm@openbsd.org
jmc@openbsd.org
dtucker@openbsd.org
Darren Tucker
rob@openbsd.org