Git: which key do I use (may not be by default)?

Question

In my local environment (Mac OS X) I have at my home folder the .ssh folder, where there are two keys: github_rsa and id_rsa; in addition, there is a known_hosts file saying some like:

github.com,192.30.252.131 ssh-rsa blahblah
192.30.252.129 ssh-rsa blahlllblahhhh
...

Is there a way (command line preferred) for me to know which key my git command is using when interacting with Github or Bitbucket? If so, how?

Thanks.

Answer 1

The id_rsa.pub file contains the RSA public key for your user (generally the key used for connecting to GitHub, if you follow their tutorial). If you want to use the github_rsa key, you can change the key used to connect to GitHub by creating a new host definition in the ~/.ssh/config file:

Host github.com
    HostName github.com
    User git
    IdentityFile ~/.ssh/github_rsa

By the way, the known-hosts file contains the servers you have connected to and their public keys.

See also this SO question: Setting up ssh keys for GibHub