I use SSH (OpenSSH 5.5p1 on Linux, to be precise). I have a key, on which i have a passphrase. I use this for the usual logging in to computers stuff.
Can i also use it to sign files?
As i understand it, an SSH key is an RSA (or DSA) key, and during the SSH login process, it is used to sign messages sent to the server. So in principle and in practice, it can be used to sign things - indeed, that is its sole purpose.
But as far as i can see, there is no way to use the key to sign an arbitrary file (as you would with PGP, say). Is there some way to do this?