+ * Reserved, for alignment.
+ */
+ uint32_t reserved GNUNET_PACKED;
+
+ /**
+ * ID of the connection.
+ */
+ struct GNUNET_CADET_ConnectionTunnelIdentifier cid;
+
+ /**
+ * MAC of the encrypted message, used to verify message integrity.
+ * Everything after this value will be encrypted with the header key
+ * and authenticated.
+ */
+ struct GNUNET_ShortHashCode hmac;
+
+ /**
+ * Axolotl-header that specifies which keys to use in which ratchet
+ * to decrypt the body that follows.
+ */
+ struct GNUNET_CADET_AxHeader ax_header;
+
+ /**
+ * Encrypted content follows.