public static byte[] UnwrapKey(byte[] kek, byte[] ciphertext)
        {
            KeyWrapAlgorithm kwa = new KeyWrapAlgorithm(kek);

            return(kwa.UnwrapKey(ciphertext));
        }
        public static byte[] WrapKey(byte[] kek, byte[] plaintext)
        {
            KeyWrapAlgorithm kwa = new KeyWrapAlgorithm(kek);

            return(kwa.WrapKey(plaintext));
        }