public void roundTrip()
        {
            EnvelopedMessage msg = new EnvelopedMessage();

            msg.AddAttribute(HeaderKeys.Algorithm, AlgorithmValues.AES_GCM_128, true);
            msg.AddAttribute(HeaderKeys.IV, CBORObject.FromObject(rgbIV96), false);
            msg.SetContent(strContent);
            Recipient r = new Recipient(key128, AlgorithmValues.Direct);

            msg.AddRecipient(r);
            msg.Encrypt();
            byte[] rgbMsg = msg.EncodeToBytes();

            msg = (EnvelopedMessage)Message.DecodeFromBytes(rgbMsg);
            r   = msg.RecipientList[0];
            r.SetKey(key128);
            msg.Decrypt(r);

            Assert.AreEqual <string>(msg.GetContentAsString(), strContent);
        }