Summary:
Ref T5833. Currently, SSH keys are associated only with users, and are a bit un-modern. I want to let Almanac Devices have SSH keys so devices in a cluster can identify to one another.
For example, with hosted installs, initialization will go something like this:
- A request comes in for `company.phacility.com`.
- A SiteSource (from D10787) makes a Conduit call to Almanac on the master install to check if `company` is a valid install and pull config if it is.
- This call can be signed with an SSH key which identifies a trusted Almanac Device.
In the cluster case, a web host can make an authenticated call to a repository host with similar key signing.
To move toward this, put a proper Query class on top of SSH key access (this diff). In following diffs, I'll:
- Rename `userPHID` to `objectPHID`.
- Move this to the `auth` database.
- Provide UI for device/key association.
An alternative approach would be to build some kind of special token layer in Conduit, but I think that would be a lot harder to manage in the hosting case. This gives us a more direct attack on trusting requests from machines and recognizing machines as first (well, sort of second-class) actors without needing things like fake user accounts.
Test Plan:
- Added and removed SSH keys.
- Added and removed SSH keys from a bot account.
- Tried to edit an unonwned SSH key (denied).
- Ran `bin/ssh-auth`, got sensible output.
- Ran `bin/ssh-auth-key`, got sensible output.
Reviewers: btrahan
Reviewed By: btrahan
Subscribers: epriestley
Maniphest Tasks: T5833
Differential Revision: https://secure.phabricator.com/D10790
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
