How do I get certificate's key size

Question

I have an X.509 certificate and need to get the size of its key (in bits) - e.g., 1024 2048 etc. I have looked at X509Certificate2 and also the bouncycastle X509Certificate classes but can't see how to get the key size.

Answer 1

You surely have access to the public key. The key length is public key's size: this.PublicKey.Key.KeySize;
To see an implemented solution, check out this article on MSDN