Commit Graph

93 Commits (a04f1ff9e67864d1e474d7d4326ce03aafdc7480)

Author SHA1 Message Date
Brad Fitzpatrick e24de8a617 ssh/tailssh: add password-forcing workaround for buggy SSH clients
If the username includes a suffix of +password, then we accept
password auth and just let them in like it were no auth.

This exists purely for SSH clients that get confused by seeing success
to their initial auth type "none".

Co-authored-by: Maisem Ali <maisem@tailscale.com>
Change-Id: I616d4c64d042449fb164f615012f3bae246e91ec
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2 years ago
Emmanuel T Odeke 680f8d9793 all: fix more resource leaks found by staticmajor
Updates #5706

Signed-off-by: Emmanuel T Odeke <emmanuel@orijtech.com>
2 years ago
Maisem Ali f172fc42f7 ssh/tailssh: close sshContext on context cancellation
This was preventing tailscaled from shutting down properly if there were
active sessions in certain states (e.g. waiting in check mode).

Signed-off-by: Maisem Ali <maisem@tailscale.com>
2 years ago
Maisem Ali 4de1601ef4 ssh/tailssh: add support for sending multiple banners
Signed-off-by: Maisem Ali <maisem@tailscale.com>
2 years ago
Maisem Ali ecf6cdd830 ssh/tailssh: add TestSSHAuthFlow
Signed-off-by: Maisem Ali <maisem@tailscale.com>
2 years ago
Maisem Ali f16b77de5d ssh/tailssh: do the full auth flow during ssh auth
Fixes #5091

Signed-off-by: Maisem Ali <maisem@tailscale.com>
2 years ago
Maisem Ali b84ec521bf ssh/tailssh: do not send EOT on session disconnection
This was assumed to be the fix for mosh not working, however turns out
all we really needed was the duplicate fd also introduced in the same
commit (af412e8874).

Fixes #5103

Signed-off-by: Maisem Ali <maisem@tailscale.com>
2 years ago
Brad Fitzpatrick b1bd96f114 go.mod, ssh/tailssh: fix ImplictAuthMethod typo
Fixes #5745

Change-Id: Ie8bc88bd465a9cb35b0ae7782d61ce96480473ee
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2 years ago
Josh Soref d4811f11a0 all: fix spelling mistakes
Signed-off-by: Josh Soref <2119212+jsoref@users.noreply.github.com>
2 years ago
Eng Zer Jun f0347e841f refactor: move from io/ioutil to io and os packages
The io/ioutil package has been deprecated as of Go 1.16 [1]. This commit
replaces the existing io/ioutil functions with their new definitions in
io and os packages.

Reference: https://golang.org/doc/go1.16#ioutil
Signed-off-by: Eng Zer Jun <engzerjun@gmail.com>
2 years ago
Brad Fitzpatrick 74674b110d envknob: support changing envknobs post-init
Updates #5114

Change-Id: Ia423fc7486e1b3f3180a26308278be0086fae49b
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2 years ago
Brad Fitzpatrick 4950fe60bd syncs, all: move to using Go's new atomic types instead of ours
Fixes #5185

Change-Id: I850dd532559af78c3895e2924f8237ccc328449d
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2 years ago
Brad Fitzpatrick 8725b14056 all: migrate more code code to net/netip directly
Instead of going through the tailscale.com/net/netaddr transitional
wrappers.

Updates #5162

Change-Id: I3dafd1c2effa1a6caa9b7151ecf6edd1a3fda3dd
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2 years ago
Maisem Ali 02a765743e ssh/tailssh: fix deadlock in expandDelegateURL
Also rename it to expandDelegateURLLocked, previously it was trying
to acquire the mutex while holding the mutex.

Fixes #5235

Signed-off-by: Maisem Ali <maisem@tailscale.com>
2 years ago
Brad Fitzpatrick a12aad6b47 all: convert more code to use net/netip directly
perl -i -npe 's,netaddr.IPPrefixFrom,netip.PrefixFrom,' $(git grep -l -F netaddr.)
    perl -i -npe 's,netaddr.IPPortFrom,netip.AddrPortFrom,' $(git grep -l -F netaddr. )
    perl -i -npe 's,netaddr.IPPrefix,netip.Prefix,g' $(git grep -l -F netaddr. )
    perl -i -npe 's,netaddr.IPPort,netip.AddrPort,g' $(git grep -l -F netaddr. )
    perl -i -npe 's,netaddr.IP\b,netip.Addr,g' $(git grep -l -F netaddr. )
    perl -i -npe 's,netaddr.IPv6Raw\b,netip.AddrFrom16,g' $(git grep -l -F netaddr. )
    goimports -w .

Then delete some stuff from the net/netaddr shim package which is no
longer neeed.

Updates #5162

Change-Id: Ia7a86893fe21c7e3ee1ec823e8aba288d4566cd8
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2 years ago
Brad Fitzpatrick 6a396731eb all: use various net/netip parse funcs directly
Mechanical change with perl+goimports.

Changed {Must,}Parse{IP,IPPrefix,IPPort} to their netip variants, then
goimports -d .

Finally, removed the net/netaddr wrappers, to prevent future use.

Updates #5162

Change-Id: I59c0e38b5fbca5a935d701645789cddf3d7863ad
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2 years ago
Brad Fitzpatrick 7eaf5e509f net/netaddr: start migrating to net/netip via new netaddr adapter package
Updates #5162

Change-Id: Id7bdec303b25471f69d542f8ce43805328d56c12
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2 years ago
Maisem Ali 3e06b9ea7a ssh/tailssh: add "ssh" to conn logs
Fixes #5089

Signed-off-by: Maisem Ali <maisem@tailscale.com>
2 years ago
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>
2 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>
2 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>
2 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>
2 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>
2 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