24f771c1bc
Summary: Depends on D20873. Ref T13436. Allow callers to configure "bin/ssh-auth --sshd-key %k" as an "AuthorizedKeysCommand"; if they do, and we recognize the key, emit just that key in the output. Test Plan: - Used `git pull` locally, still worked fine. - Instrumented things, saw the public key lookup actually work and emit a single key. - Ran without "--sshd-key", got a full key list as before. Maniphest Tasks: T13436 Differential Revision: https://secure.phabricator.com/D20874