Commit Graph

125 Commits (583e86b7df8ef12c0a988276d2276f3b2b35d745)

Author SHA1 Message Date
Maisem Ali 480fd6c797 ssh/tailssh: handle not-authenticated-yet connections in matchRule
Also make more fields in conn.info thread safe, there was previously a
data race here.

Fixes #5110

Signed-off-by: Maisem Ali <maisem@tailscale.com>
2 years ago
Maisem Ali af412e8874 ssh/tailssh: better handling of signals and exits
We were not handling errors occurred while copying data between the subprocess and the connection.
This makes it so that we pass the appropriate signals when to the process and the connection.

This also fixes mosh.

Updates #4919

Co-authored-by: James Tucker <raggi@tailscale.com>
Co-authored-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Signed-off-by: Maisem Ali <maisem@tailscale.com>
2 years ago
Brad Fitzpatrick 3b1f99ded1 ssh/tailssh: fix Tailscale SSH to Linux Arch machines
See https://github.com/tailscale/tailscale/issues/4924#issuecomment-1168201823

Arch uses a different login binary that makes the -h flag set the PAM
service to "remote". So if they don't have that configured, don't pass -h.

Thanks to @eddiezane for debugging!

Updates #4924

Change-Id: I8d33e0afb2dfb99517bcea2f9d5d0c6247519b3c
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2 years ago
Maisem Ali 40503ef07a ssh/tailssh: fix logging typo
Signed-off-by: Maisem Ali <maisem@tailscale.com>
2 years ago
Maisem Ali c434e47f2d ssh/tailssh: always use current time for policy evaluation
Whenever the SSH policy changes we revaluate all open connections to
make sure they still have access. This check was using the wrong
timestamp and would match against expired policies, however this really
isn't a problem today as we don't have policy that would be impacted by
this check. Fixing it for future use.

Signed-off-by: Maisem Ali <maisem@tailscale.com>
2 years ago
Maisem Ali a7d2024e35 ssh/tailssh: allow multiple sessions on the same conn
Fixes #4920
Fixes tailscale/corp#5633
Updates #4479

Signed-off-by: Maisem Ali <maisem@tailscale.com>
2 years ago
Adam Eijdenberg 9294a14a37 ssh/tailssh: limit setgroups to 16 on macOS
Fixes #4938

Signed-off-by: Adam Eijdenberg <adam@continusec.com>
2 years ago
Adam Eijdenberg 7f807fef6c ssh/tailssh: fix /usr/bin/login args on macOS
Fixes #4931

Signed-off-by: Adam Eijdenberg <adam@continusec.com>
2 years ago
Brad Fitzpatrick e428bba7a3 ssh/tailssh: add metrics
Updates #3802

Change-Id: Ic9a4b8c51cff6dfe148a1c78bc0e5074195b7f80
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Maisem Ali 928530a112 ipn/ipnlocal: shutdown sshServer on tailscale down
Also lazify SSHServer initialization to allow restarting the server on a
subsequent `tailscale up`

Updates #3802

Signed-off-by: Maisem Ali <maisem@tailscale.com>
3 years ago
Maisem Ali 575aacb1e2 ssh/tailssh: terminate sessions on stdout copy failures
Currently, killing a SCP copy with a Ctrl+C leaves the session hanging
even though the stdout copy goroutine fails with an io.EOF. Taking a
step back, when we are unable to send any more data back to the client
we should just terminate the session as the client will stop getting any
response from the server anyways.

Updates #3802

Signed-off-by: Maisem Ali <maisem@tailscale.com>
3 years ago
Maisem Ali 7cd8c3e839 ssh/tailssh: terminate sessions when tailscaled shutsdown
Ideally we would re-establish these sessions when tailscaled comes back
up, however we do not do that yet so this is better than leaking the
sessions.

Updates #3802

Signed-off-by: Maisem Ali <maisem@tailscale.com>
3 years ago
Maisem Ali 760740905e ssh/tailssh: only use `login` with TTY sessions
Otherwise, the shell exits immediately causing applications like mosh
and VSCode to fail.

Signed-off-by: Maisem Ali <maisem@tailscale.com>
3 years ago
Maisem Ali 5cd56fe8d5 ssh/tailssh: exec into `login` when launching a shell
This has the added benefit of displaying the MOTD and reducing our
dependency on the DBus interface.

Fixes #4627
Updates #3802

Signed-off-by: Maisem Ali <maisem@tailscale.com>
3 years ago
Maisem Ali a253057fc3 ssh/tailssh: refactor incubator flags
Signed-off-by: Maisem Ali <maisem@tailscale.com>
3 years ago
Brad Fitzpatrick c1445155ef ssh/tailssh: handle Control-C during hold-and-delegate prompt
Fixes #4549

Change-Id: Iafc61af5e08cd03564d39cf667e940b2417714cc
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Maisem Ali 3012a2e1ca ssh/tailssh,ipn/ipnlocal: terminate any active sessions on `up --ssh=false`
Currently the ssh session isn't terminated cleanly, instead the packets
are just are no longer routed to the in-proc SSH server. This makes it
so that clients get a disconnection when the `RunSSH` pref changes to
`false`.

Updates #3802

Signed-off-by: Maisem Ali <maisem@tailscale.com>
3 years ago
Brad Fitzpatrick 910ae68e0b util/mak: move tailssh's mapSet into a new package for reuse elsewhere
Change-Id: Idfe95db82275fd2be6ca88f245830731a0d5aecf
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
James Tucker c2eff20008 ssh/tailssh: avoid user ssh configuration in tests
Signed-off-by: James Tucker <james@tailscale.com>
3 years ago
David Anderson a364bf2b62 ssh/tailssh: various typo fixes, clarifications.
Signed-off-by: David Anderson <danderson@tailscale.com>
3 years ago
Brad Fitzpatrick c994eba763 ssh/tailssh: simplify matchRule with Reject rules
Updates #3802

Change-Id: I59fe111eef5ac8abbcbcec922e293712a65a4830
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Maisem Ali 31094d557b ssh/tailssh: chmod the auth socket to be only user accessible
Updates #3802

Signed-off-by: Maisem Ali <maisem@tailscale.com>
3 years ago
Maisem Ali 337c77964b ssh/tailssh: set groups and gid in the incubated process
Updates #3802

Signed-off-by: Maisem Ali <maisem@tailscale.com>
3 years ago
Brad Fitzpatrick 8ac4d52b59 ssh/tailssh: filter accepted environment variables
Noted by @danderson

Updates #3802

Change-Id: Iac70717ed57f11726209ac1ea93ddc6696605f94
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick 89832c1a95 tailcfg: fix typo in SessionDuration field name
Noted by @danderson.

Updates #3802

Change-Id: Ide15f3f28e30f6abb5c94d7dcd218bd9482752a0
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Maisem Ali 695f8a1d7e ssh/tailssh: add support for sftp
Updates #3802

Signed-off-by: Maisem Ali <maisem@tailscale.com>
3 years ago
Brad Fitzpatrick 5b4154342e ssh/tailssh: fix double SSH-2.0- prefix in greeting banner
gliderlabs/ssh was already adding the "SSH-2.0-" prefix.

Updates #3802

Change-Id: I19a1cd9308371a2898e7883cf26e94c9b54bab29
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Maisem Ali 2b8b887d55 ssh/tailssh: send banner messages during auth, move more to conn
(VSCode Live Share between Brad & Maisem!)

Updates #3802

Change-Id: Id8edca4481b0811debfdf56d4ccb1a46f71dd6d3
Co-Authored-By: Brad Fitzpatrick <bradfitz@tailscale.com>
Signed-off-by: Maisem Ali <maisem@tailscale.com>
3 years ago
Brad Fitzpatrick f74ee80abe ssh/tailssh: support expansions in public key fetch URL too
Updates #3802

Change-Id: I5aa98bdab14fd1c1c00ba63b93f8d7e670f72437
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Maisem Ali 14d077fc3a ssh/tailssh: terminate ssh auth early if no policy can match
Also bump github.com/tailscale/golang-x-crypto/ssh

Updates #3802

Signed-off-by: Maisem Ali <maisem@tailscale.com>
3 years ago
Brad Fitzpatrick 8b81254992 ipn/ipnlocal: reject tailscale up --ssh if disabled on tailnet
Updates #3802

Change-Id: I3f1e839391fe9b28270f506f4bb8d8e3d36716f5
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Maisem Ali 91a187bf87 ssh/tailssh: make checkStillValid also consider username changes
Currently if the policy changes and the session is logged in with local
user "u1" and the new policy says they can only login with "u2" now, the
user doesn't get kicked out because they had requested
`rando@<ssh-host>` and the defaulting had made that go to `u1`.

Signed-off-by: Maisem Ali <maisem@tailscale.com>
3 years ago
Brad Fitzpatrick 93221b4535 ssh/tailssh: cache public keys fetched from URLs
Updates #3802

Change-Id: I96715bae02bce6ea19f16b1736d1bbcd7bcf3534
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick ade7bd8745 ssh/tailssh: close sessions on policy change if no longer allowed
Updates #3802

Change-Id: I98503c2505b77ac9d0cc792614fcdb691761a70c
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick 8ee044ea4a ssh/tailssh: make the SSH server a singleton, register with LocalBackend
Remove the weird netstack -> tailssh dependency and instead have tailssh
register itself with ipnlocal when linked.

This makes tailssh.server a singleton, so we can have a global map of
all sessions.

Updates #3802

Change-Id: Iad5caec3a26a33011796878ab66b8e7b49339f29
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick da14e024a8 tailcfg, ssh/tailssh: optionally support SSH public keys in wire policy
And clean up logging.

Updates #3802

Change-Id: I756dc2d579a16757537142283d791f1d0319f4f0
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick 3d180c0376 go.mod, ssh/tailssh, tempfork/gliderlabs: bump x/crypto/ssh fork for NoClientAuthCallback
Prep for evaluating SSHPolicy earlier to decide whether certs are
required, which requires knowing the target SSH user.

Updates #3802

Change-Id: I2753ec8069e7f19c9121300d0fb0813c1c627c36
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick 5a44f9f5b5 tempfork: temporarily fork gliderlabs/ssh and x/crypto/ssh
While we rearrange/upstream things.

gliderlabs/ssh is forked into tempfork from our prior fork
at be8b7add40

x/crypto/ssh OTOH is forked at
https://github.com/tailscale/golang-x-crypto because it was gnarlier
to vendor with various internal packages, etc.
Its git history shows where it starts (2c7772ba30643b7a2026cbea938420dce7c6384d).

Updates #3802

Change-Id: I546e5cdf831cfc030a6c42557c0ad2c58766c65f
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick 0861923c21 ssh/tailssh, tailcfg: add more HoldAndDelegate expansions, document
Updates #3802

Change-Id: I447f06b49e2a917bffe36881d0634c9195085512
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick 091ea4a4a5 ssh/tailssh: support placeholders in SSHAction.HoldAndDelegate URL
Updates #3802

Change-Id: I60f9827409d14fd4f4824d102ba11db49bf0d365
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick f7e976db55 tailcfg, ssh/tailssh: make SSHUser value '=' map ssh-user to same local-user
Updates #3802

Change-Id: Icde60d4150ca15c25d615a4effb3d3c236f020a8
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick f30473211b ssh/tailssh: start of implementing optional session recording
To asciinema cast format.

Updates #3802

Change-Id: Ifd3ea31922cd2c99068369cb1650e21f2545b0e1
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Josh Bleecher Snyder 32fd42430b all: use cibuild.On
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
3 years ago
Maisem Ali b775df0b57 ssh/tailssh_test: skip TestSSH/stdin in CI
Updates #4051

Signed-off-by: Maisem Ali <maisem@tailscale.com>
3 years ago
Maisem Ali 1e12a29806 ssh/tailssh_test: Skip the env test in CI
Updates #4051

Signed-off-by: Maisem Ali <maisem@tailscale.com>
3 years ago
Josh Bleecher Snyder 0868329936 all: use any instead of interface{}
My favorite part of generics.

Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
3 years ago
Maisem Ali 45a7f6689c tailcfg: add field to allow LocalPortForwarding in SSHAction
Updates #3802, #4129

Signed-off-by: Maisem Ali <maisem@tailscale.com>
3 years ago
Maisem Ali 98b45ef12c ssh/tailssh: add support for agent forwarding.
Updates #3802

Signed-off-by: Maisem Ali <maisem@tailscale.com>
3 years ago
Brad Fitzpatrick 6e86bbcb06 ssh/tailssh: add a new sshSession type to clean up existing+future code
Updates #3802

Change-Id: I7054dca387f5e5aee1185937ecf41b77a5a07f1a
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Co-authored-by: Maisem Ali <maisem@tailscale.com>
3 years ago
Maisem Ali 462e75666b ssh/tailssh: start sending the server version
Updates #3802

Signed-off-by: Maisem Ali <maisem@tailscale.com>
3 years ago
Maisem Ali bf3559171f ssh/tailssh: set DBUS_SESSION_BUS_ADDRESS and SSH_TTY variables
Updates #3802

Signed-off-by: Maisem Ali <maisem@tailscale.com>
3 years ago
Maisem Ali 6d61b7906e ssh/tailssh: handle terminal opcodes
Updates #3802 #4146

Signed-off-by: Maisem Ali <maisem@tailscale.com>
3 years ago
Maisem Ali da6ce27416 go.mod: move from github.com/gliderlabs/ssh to github.com/tailscale/ssh
Updates #4146

Signed-off-by: Maisem Ali <maisem@tailscale.com>
3 years ago
Brad Fitzpatrick 012098ec32 ssh/tailssh: fix terminal corruption (temporary hack)
Maisem figured out the real problem but will take several commits
(e.g. tailscale/ssh#2) in different repos to get it fixed
properly. This is an interim hack.

Details of real fix:
https://github.com/tailscale/tailscale/issues/4146#issuecomment-1065952947

Updates #4146
Updates #3802

Change-Id: I7b7dc5713baa3e5de75b87b69e7179a6e7549b0b
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick ba1adf6c24 ssh/tailssh: make pty termios options match OpenSSH
Still not sure the exact rules of how/when/who's supposed to set
these, but this works for now on making them match. Baby steps.
Will research more and adjust later.

Updates #4146 (but not enough to fix it, something's still wrong)
Updates #3802

Change-Id: I496d8cd7e31d45fe9ede88fc8894f35dc096de67
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick 1dd5cf62a5 ssh/tailssh: start login shell, fix arg passing, width/height mismatch
Updates #3802

Change-Id: I137d7a79195ee86d5dd7c8999f2797fc3cb57cec
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick efc48b0578 ssh/tailssh, ipnlocal, controlclient: fetch next SSHAction from network
Updates #3802

Change-Id: I08e98805ab86d6bbabb6c365ed4526f54742fd8e
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Maisem Ali 56bf2ce642 ssh/tailssh: handle local port forwarding
Updates #3802

Signed-off-by: Maisem Ali <maisem@tailscale.com>
3 years ago
Maisem Ali 598c7a22e7 ssh/tailssh: use lu.Username not lu.Name.
Signed-off-by: Maisem Ali <maisem@tailscale.com>
3 years ago
Maisem Ali 06c147d848 ssh/tailssh: create login sessions for new connections
Signed-off-by: Maisem Ali <maisem@tailscale.com>
3 years ago
Brad Fitzpatrick c9a5dadce8 ssh/tailssh: skip flaky test on CI for now
Updates #4051

Change-Id: I94f2165dd248eba9ca3f782c907a13bd6dde4a5e
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Maisem Ali 497324ddf6 ipn/store: add common package for instantiating ipn.StateStores
Also move KubeStore and MemStore into their own package.

RELNOTE: tsnet now supports providing a custom ipn.StateStore.

Signed-off-by: Maisem Ali <maisem@tailscale.com>
3 years ago
Brad Fitzpatrick 4b50977422 ssh/tailssh: add more SSH tests, blend in env from ssh session
Updates #3802

Change-Id: I568c661cacbb0524afcd8be9577457ddba611f19
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick 4cbdc84d27 cmd/tailscaled/childproc: add be-child registration mechanism
For ssh and maybe windows service babysitter later.

Updates #3802

Change-Id: I7492b98df98971b3fb72d148ba92c2276cca491f
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick 6e4f3614cf ssh/tailssh: add start of real ssh tests
Updates #3802

Change-Id: I9aea4250062d3a06ca7a5e71a81d31c27a988615
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick c9eca9451a ssh: make it build on darwin
For local dev testing initially. Product-wise, it'll probably only be
workable on the two unsandboxed builds.

Updates #3802

Change-Id: Ic352f966e7fb29aff897217d79b383131bf3f92b
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick cce6aad6c0 ssh/tailssh: fix non-interactive commands as non-root user
Updates #3802

Change-Id: I89a3f14420b8782bc407b1939dce54a1d24636da
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick e2ed06c53c ssh/tailssh: break a method into half in prep for testing
And add a private context type in the process.

Updates #3802

Change-Id: I257187f4cfb0f2248d95b81c1dfe0911ef203b60
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick 1b5bb2e81d ssh/tailssh: rename sshContext to sshConnInfo
So it's not confused for a context.Context and we can add contexts
later and not look like we have two.

Updates #3802

Change-Id: Icf229ae2c020d173f3cbf09a13ccd03a60cbb85e
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick 3c2cd854be ssh/tailssh: flesh out env, support non-pty commands
Updates #3802

Change-Id: I7022460117542a5424919144828bf571c7c19ec0
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick 03caa95bf2 ssh/tailssh: get login shell when running as non-root
And also reject attempts to use other users.

Updates #3802

Change-Id: Iddc85f6ea2dba17d12be66a50408d24c1f92833e
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick e1e20f6d39 ssh/tailssh: evaluate tailcfg.SSHPolicy on incoming connections
Updates #3802
Fixes #3960

Change-Id: Ieda2007d462ddce6c217b958167417ae9755774e
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick bb93e29d5c tailcfg, ipn/ipnlocal: add Hostinfo.SSH_HostKeys, send when SSH enabled
(The name SSH_HostKeys is bad but SSHHostKeys is worse.)

Updates #3802

Change-Id: I2a889019c9e8b065b668dd58140db4fcab868a91
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick fbff1555fc ipnlocal, tailssh: start moving host key stuff into the right spot
Make tailssh ask LocalBackend for the SSH hostkeys, as we'll need to
distribute them to peers.

For now only the hacky use-same-as-actual-host mode is implemented.

Updates #3802

Change-Id: I819dcb25c14e42e6692c441186c1dc744441592b
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick 1b87e025e9 ssh/tailssh: move SSH code from wgengine/netstack to this new package
Still largely incomplete, but in a better home now.

Updates #3802

Change-Id: I46c5ffdeb12e306879af801b06266839157bc624
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago