How does gitosis know who the key belongs to

Hi,

This is probably another one of my stupid questions.

Gitosis obviously uses keypairs but the config file addresses the user
by name/host. How does gitosis connect the two together? Is it any
more complicated than the user detail at the end of the public key?

The second part of my question then is is it possible to use the same
private key on more than one host?

Cheers,

Howard