This splits the user authentication code from the sshd-session
binary into a separate sshd-auth binary. This will be executed by
sshd-session to complete the user authentication phase of the
protocol only.
Splitting this code into a separate binary ensures that the crucial
pre-authentication attack surface has an entirely disjoint address
space from the code used for the rest of the connection. It also
yields a small runtime memory saving as the authentication code will
be unloaded after thhe authentication phase completes.
Joint work with markus@ feedback deraadt@
Tested in snaps since last week
OpenBSD-Commit-ID: 9c3b2087ae08626ec31b4177b023db600e986d9c
Cygwin doesn't support FD passing and so used to disable post-auth
privilege separation entirely because privsep requires PTY allocation
to happen in the privileged monitor process with the PTY file
descriptors being passed back to the unprivileged process.
This brings back a minimal version of the previous special treatment
for Cygwin (and any other platform that sets DISABLE_FD_PASSING):
privilege separation remains enabled, but PTY allocation happens in
the post-auth user process rather than the monitor.
This either requires PTY allocation to not need privilege to begin
with (this appears to be the case on Cygwin), or the post-auth
privsep process retain privilege (other platforms that set the
DISABLE_FD_PASSING option).
Keeping privileges here is bad, but the non-Cygwin systems that set
DISABLE_FD_PASSING are so deeply legacy that this is likely to be the
least of their problems.
binaries. This step splits sshd into a listener and a session binary. More
splits are planned.
After this changes, the listener binary will validate the configuration,
load the hostkeys, listen on port 22 and manage MaxStartups only. All
session handling will be performed by a new sshd-session binary that the
listener fork+execs.
This reduces the listener process to the minimum necessary and sets us
up for future work on the sshd-session binary.
feedback/ok markus@ deraadt@
NB. if you're updating via source, please restart sshd after installing,
otherwise you run the risk of locking yourself out.
OpenBSD-Commit-ID: 43c04a1ab96cdbdeb53d2df0125a6d42c5f19934
We've previously removed a lot of the really old compatibility code,
and with it went the need to include compat.h in most of the files that
have it.
OpenBSD-Commit-ID: 5af8baa194be00a3092d17598e88a5b29f7ea2b4
This sets an "extended" channel type after channel creation (e.g.
"session:subsystem:sftp") that will be used for setting channel inactivity
timeouts.
ok markus dtucker
OpenBSD-Commit-ID: 42564aa92345045b4a74300528f960416a15d4ca
These are now used by sshd_config:ChannelTimeouts to specify timeouts by
channel type, so force them all to use a similar format without whitespace.
ok dtucker markus
OpenBSD-Commit-ID: 66834765bb4ae14f96d2bb981ac98a7dae361b65
This will forcibly close an open channel by simulating read/write errors,
draining the IO buffers and calling the detach function.
Previously the detach function was only ever called during channel garbage
collection, but there was no way to signal the user of a channel (e.g.
session.c) that its channel was being closed deliberately (vs. by the
usual state-machine logic). So this adds an extra "force" argument to the
channel cleanup callback to indicate this condition.
ok markus dtucker
OpenBSD-Commit-ID: 23052707a42bdc62fda2508636e624afd466324b
Historicallly, hpdelim accepted ":" or "/" as a port delimiter between
hosts (or addresses) and ports. These days most of the uses for "/"
are no longer accepted, so there are several places where it checks the
delimiter to disallow it. Make hpdelim accept only ":" and use hpdelim2
in the other cases. ok djm@
OpenBSD-Commit-ID: 7e6420bd1be87590b6840973f5ad5305804e3102
OpenBSD and NetBSD require the caller to free strings returned
bu the login_* functions, but FreeBSD requires that callers don't.
Fortunately in this case, we can harmlessly leak as the process is
about to exec the shell/command.
From https://reviews.freebsd.org/D28617 via Ed Maste; ok dtucker@
sshd is in chroot mode, the likely absence of a password database will cause
tilde_expand_filename() to fatal; ok dtucker@
OpenBSD-Commit-ID: e20aee6159e8b79190d18dba1513fc1b7c8b7ee1
being relative to the current directory, so that it'll still be found if the
shell startup changes its directory. Since the path is potentially longer,
make the cmd buffer that uses it dynamically sized. bz#3185, with & ok djm@
OpenBSD-Commit-ID: 36e33ff01497af3dc8226d0c4c1526fc3a1e46bf
sigaction(2). This wrapper blocks all other signals during the handler
preventing races between handlers, and sets SA_RESTART which should reduce
the potential for short read/write operations.
OpenBSD-Commit-ID: 5e047663fd77a40d7b07bdabe68529df51fd2519
some arbitrary value < 0. errno is only updated in this case. Change all
(most?) callers of syscalls to follow this better, and let's see if this
strictness helps us in the future.
OpenBSD-Commit-ID: 48081f00db7518e3b712a49dca06efc2a5428075
setup error path with user's privileged. This is a no-op as this code always
runs with user privilege now that we no longer support running sshd with
privilege separation disabled, but as long as the privsep skeleton is there
we should follow the rules.
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
bz#2969 with patch from Erik Sjölund
OpenBSD-Commit-ID: 2b708401a5a8d6133c865d7698d9852210dca846
API. This code is not normally reachable since USE_PIPES is always defined.
bz#2961, patch from adrian.fita at gmail com.
OpenBSD-Commit-ID: 8d8428d678d1d5eb4bb21921df34e8173e6d238a
API, started almost exactly six years ago.
This change stops including the old packet_* API by default and makes
each file that requires the old API include it explicitly. We will
commit file-by-file refactoring to remove the old API in consistent
steps.
with & ok markus@
OpenBSD-Commit-ID: 93c98a6b38f6911fd1ae025a1ec57807fb4d4ef4
disposition of channel's extended (stderr) fd; makes debugging some things a
bit easier. No behaviour change.
OpenBSD-Commit-ID: 483eb6467dc7d5dbca8eb109c453e7a43075f7ce
channel/ session protocol. Signalling is only supported to sesssions that are
not subsystems and were not started with a forced command.
Long requested in bz#1424
Based on a patch from markus@ and reworked by dtucker@;
ok markus@ dtucker@
OpenBSD-Commit-ID: 4bea826f575862eaac569c4bedd1056a268be1c3
