How to decrypt an encrypted container via ssh without entering a passphrase while requiring some client authentication?

I log in to a server via public key authentication and then mount a container (using e.g. LUKS/dm-crypt or truecrypt). At the moment, I have to enter the container password manually. Is there a way to secure that container using e.g. the ssh agent? Or if that is not possible directly, can I encrypt the container password (or probably better, keyfile) with the ssh public key and use ssh agent to decrypt it temporarily?