mirror of
https://we.phorge.it/source/phorge.git
synced 2024-12-23 14:00:56 +01:00
888b3839e7
Summary: Fixes T2229. This sets the stage for a patch similar to D7417, but for SSH. In particular, SSH 6.2 introduced an `AuthorizedKeysCommand` directive, which lets us do this in a mostly-reasonable way without needing users to patch sshd (if they have a recent enough version, at least). The way the `AuthorizedKeysCommand` works is that it gets run and produces an `authorized_keys`-style file fragment. This isn't ideal, because we have to dump every key into the result, but should be fine for most installs. The earlier patch against `sshd` passes the public key itself, which allows the script to just look up the key. We might use this eventually, since it can scale much better, so I haven't removed it. Generally, auth is split into two scripts now which mostly do the same thing: - `ssh-auth` is the AuthorizedKeysCommand auth, which takes nothing and dumps the whole keyfile. - `ssh-auth-key` is the slightly cleaner and more scalable (but patch-dependent) version, which takes the public key and dumps only matching options. I also reworked the argument parsing to be a bit more sane. Test Plan: This is somewhat-intentionally a bit obtuse since I don't really want anyone using it yet, but basically: - Copy `phabricator-ssh-hook.sh` to somewhere like `/usr/libexec/openssh/`, chown it `root` and chmod it `500`. - This script should probably also do a username check in the future. - Create a copy of `sshd_config` and fix the paths/etc. Point the KeyScript at your copy of the hook. - Start a copy of sshd (6.2 or newer) with `-f <your config file>` and maybe `-d -d -d` to foreground and debug. - Run `ssh -p 2222 localhost` or similar. Specifically, I did this setup and then ran a bunch of commands like: - `ssh host` (denied, no command) - `ssh host ls` (denied, not supported) - `echo '{}' | ssh host conduit conduit.ping` (works) Reviewers: btrahan Reviewed By: btrahan CC: hach-que, aran Maniphest Tasks: T2229, T2230 Differential Revision: https://secure.phabricator.com/D7419
24 lines
588 B
Text
24 lines
588 B
Text
###
|
|
### WARNING: This feature is new and experimental. Use it at your own risk!
|
|
###
|
|
|
|
# You must have OpenSSHD 6.2 or newer; support for AuthorizedKeysCommand was
|
|
# added in this version.
|
|
|
|
Port 2222
|
|
AuthorizedKeysCommand /etc/phabricator-ssh-hook.sh
|
|
AuthorizedKeysCommandUser some-unprivileged-user
|
|
|
|
# You may need to tweak these options, but mostly they just turn off everything
|
|
# dangerous.
|
|
|
|
Protocol 2
|
|
PermitRootLogin no
|
|
AllowAgentForwarding no
|
|
AllowTcpForwarding no
|
|
PrintMotd no
|
|
PrintLastLog no
|
|
PasswordAuthentication no
|
|
AuthorizedKeysFile none
|
|
|
|
PidFile /var/run/sshd-phabricator.pid
|