Thank you for your answer.

I think I should clarify a bit. I don't have any problem using IO::Socket::SSL with ordinary certificates(meaning, that I have the public and private keys as files).

My problem is how to use SSL with smart cards. One cannot extract the private key from a smart card because of security reasons(at least this is the case with the smart card I use).

With OpenSC or CAPICOM I can encrypt data with the private key - meaning, that I call the specific function and it returns the encrypted data, but I never have direct access to the private key.

So, my question is this: How do I make IO::Socket:SSL call other functions for encrypting data with private key, instead of giving it the private key. Maybe I should use other perl library, but I have no idea which.