The main server file mixed portable session handling with Unix details:
sending SIGHUP to end a session, decoding exec.ExitError, the euid check
for whether the process can switch users, agent forwarding's chown of the
socket, and reading /etc/ssh host keys as root. Those now sit behind small
functions (hangupProcess, waitProcess, canSwitchToLocalUser,
handleSSHAgentForwarding, systemHostKeyFile, isRootUser) in the new
process_unix.go, along with the incubator's forwarded-environment pipe
helpers, and the session's *exec.Cmd moves into an embedded osSessionState
struct defined there, so that the portable code no longer refers to the
process representation at all.
user.go keeps only the portable userMeta and userLookup; the login shell
and default PATH logic moves to user_unix.go. The SFTP child entrypoint and
its stdio adapter, which incubator.go and incubator_plan9.go each had a
copy of, move to sftp.go. The c2n usernames handler gains a hook for
platforms that list users some other way than /etc/passwd.
The agent socket's uid and gid are parsed as 31-bit rather than 32-bit
unsigned values so that the conversion to int for os.Chown cannot
overflow on 32-bit platforms, which is the pattern CodeQL flags.
Updates #cleanup
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Change-Id: I4c7e2b9a0d3f5e1c8b6a4d2f0e9c7b5a3d1f8e6c
Brings in a newer version of Gliderlabs SSH with added socket forwarding support.
Fixes#12409Fixes#5295
Signed-off-by: Kristoffer Dalby <kristoffer@tailscale.com>
This makes tsnet apps not depend on x/crypto/ssh and locks that in with a test.
It also paves the wave for tsnet apps to opt-in to SSH support via a
blank feature import in the future.
Updates #12614
Change-Id: Ica85628f89c8f015413b074f5001b82b27c953a9
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Brad Fitzpatrick