Selecting specific key from agent

[William Faulk]

There are cases when a user might have multiple keys in ssh-agent, but
wants to use a specific one. Unless I'm mistaken, this is currently
impossible. I've put together a proof of concept using the key's
"filename" (the third column in the output of 'ssh-add -l') and it
works.

Is this a new feature that would be accepted? If so, should the key be
identified with its "filename", or a fingerprint, or something else?
What would be an appropriate option name? Does it make more sense to
prevent loading the other keys at all, or to load them but not
transmit the ones that don't match?

-- 
Bitt Faulk