internal static extern bool CryptImportKey(
     SafeCryptoContextHandle cryptoContext, 
     byte[] key, 
     uint keyLength, 
     SafeCryptoKeyHandle pubKey, 
     CryptImportKeyFlags flags, 
     out SafeCryptoKeyHandle keyHandle);
 internal static extern bool CryptCreateHash(
     SafeCryptoContextHandle cryptoContext,
     AlgorithmId algorithmId,
     SafeCryptoKeyHandle key,
     int flags,
     out SafeCryptoHashHandle hash);