Radius PEAP protocol

Hi everyone, I am trying to create a client's interface for Radius PEAP protocol. The server has donne all I wonder it to do, but now I have a question about the finish handshake message I have to send. When I get the server's cetificate, I get a public key too. I have to "public-key-encrypt" a PreMasterSecret that is a vector of 46 random bytes and the tls version (1.0). My question is how can I do that. Am I obliged to get the ssl libraries to "public-key-encrypt" this packet? Thank you for any complemetary information. Juan Daniel MORENO