Retrieve TTL of key from the agent

[Tim Heckman]

Hello,

I'm writing a system to maintain keys within an SSH agent, and all of these
keys will only remain in the agent for a short amount of time. This is done
to limit access to that key for a short period, as well as to avoid the
agent from being cluttered up with a large number of unique SSH keys.

This system decrypts the SSH keys on the disk and then loads them in to the
agent. I would like to be able to get the key's TTL so I can decide if it's
worth decrypting the key again and loading it in to the agent, or if I
should just use the key already in the agent.

So in short, is there a way to get the TTL for a key in the agent?

Thanks!

-Tim