Best way to initiate RSACryptoServiceProvider from x509Certificate2?

Question

What is the best way to initate a new RSACryptoServiceProvider object from an X509Certificate2 I pulled out of a key store? The certificate is asso

Answer 1

Blowdart's answer is indeed correct. However, for clarity I should point out that if you want your RSACryptoServiceProvider instance to contain both the public and private keys of the X509 certificate (assuming the certificate does have a private key). Check the certificate's HasPrivateKey property.

RSACryptoServiceProvider rsa;
if (cert.HasPrivateKey)
    rsa = (RSACryptoServiceProvider)cert.PrivateKey;
else
    rsa = (RSACryptoServiceProvider)cert.PublicKey.Key;

In the case of RSA when only the public key is present the RSA Parameters will be only Exponent and Modulus, all others will be null; If on the other hand the private key is present the RSA Parameters will contain D, DP, DQ, Exponent, InverseQ, Modulus, P and Q.