Git: Blocked ssh port

I mostly clone GitHub and Bitbucket repositories using SSH URLs, so that I can protect this access with an SSH private/public key pair. Unfortunately, some firewalls refuse to allow SSH connections. Thankfully both GitHub and Bitbucket support using an SSH connection made over the HTTPS port. Most firewall rules should allow this – though proxy servers may still interfere.

To enable this, edit ~/.ssh/config, and add the following section:

Host github.com
  Hostname ssh.github.com
  Port 443
Host bitbucket.org
  Hostname altssh.bitbucket.org
  Port 443