GitHub AuthorizedKeysCommand (hubakc)

Heavily inspired by https://github.com/sequencer/gitakc . It allows someone login to the server using their ssh keys on GitHub.

1. Put config.toml in /etc/hubakc/config.toml, and add user map.
2. Put the binary in /usr/local/bin/hubakc. Make sure that the owner is root and the permission is 755.
3. Edit the sshd config as follows:

AuthorizedKeysCommand /usr/local/bin/hubakc AuthorizedKeysCommandUser nobody

Example

Given the config file config.toml

```toml ttl = 3600 timeout = 5 cache_folder = "/tmp/hubakc"

http_proxy = "127.0.0.1:1080"

[user_map] mgt = "Enter-tainer" jumpuser = ["Enter-tainer", "Shawlleyw"] ```

```bash

hubakc mgt ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIJgIynaQvTeYZ5iPigLnYRkRThxE04U7ACjuHRkQBAk+ ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIL2C/osNvVrilQDE3T/tTK9TRQ0+xVSbFU6wN5oIr2Fv ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAINKvQJ1fgkAS2yuy+cbl8iYaiw0IR4lkQIJIKgj7liax ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIKSkhuW2F4UCnIa4b2m0gUt4A5Bv+UYGsUYEl9VmLJbu ```