#!/usr/bin/env python
#
# Restrict an ssh authorized_keys entry to be used only for git push
# and git fetch.  Use thusly:
#
#  command="git-remote-only /path/to/repository.git alice@example.org" ssh-rsa ABCDEF....== alice@example.org dedicated git key
#
# You might also want options like no-port-forwarding,no-X11-forwarding,no-agent-forwarding.

import os, sys, shlex

os.environ.update(GIT_REMOTE_ONLY_COMMAND = " ".join(sys.argv))

cmd = shlex.split(os.getenv("SSH_ORIGINAL_COMMAND", ""))

if len(cmd) == 2 and cmd[0] in ("git-upload-pack", "git-receive-pack") and cmd[1] == sys.argv[1]:
    os.execv("/usr/bin/" + cmd[0], cmd)

sys.exit("Not authorized: {}".format(" ".join(cmd)))