I need to encrypt and decrypt using RSA

[Jaime Viz�n Gonz�lez]

Hi!   I have got a X509 certifificate, in BER format, from smartcard. I need to encrypt a random number using the public key which is stored in that certificate. Afeter, I want to decrypt that number. And my problem is: How can I get the public key from certificate? How can I get the private Key from certificate? How can I encrypt and decrypt a random number using RSA?   Can you help me?   Thanks