public override byte[] DecryptKeyExchange(byte[] rgbData)
        {
            if (rsa == null)
            {
                string msg = Locale.GetText("No RSA key specified");
                throw new CryptographicUnexpectedOperationException(msg);
            }
            SHA1 sha1 = SHA1.Create();

            byte[] result = PKCS1.Decrypt_OAEP(rsa, sha1, rgbData);
            if (result != null)
            {
                return(result);
            }

            throw new CryptographicException(Locale.GetText("OAEP decoding error."));
        }