1 files changed, 541 insertions, 0 deletions

diff --git a/src/service/cadet/cadet_protocol.h b/src/service/cadet/cadet_protocol.h
new file mode 100644
index 000000000..117a7922e
--- /dev/null
+++ b/src/service/cadet/cadet_protocol.h
@@ -0,0 +1,541 @@
+/*
+     This file is part of GNUnet.
+     Copyright (C) 2007 - 2017 GNUnet e.V.
+
+     GNUnet is free software: you can redistribute it and/or modify it
+     under the terms of the GNU Affero General Public License as published
+     by the Free Software Foundation, either version 3 of the License,
+     or (at your option) any later version.
+
+     GNUnet is distributed in the hope that it will be useful, but
+     WITHOUT ANY WARRANTY; without even the implied warranty of
+     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+     Affero General Public License for more details.
+
+     You should have received a copy of the GNU Affero General Public License
+     along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+     SPDX-License-Identifier: AGPL3.0-or-later
+ */
+
+/**
+ * @file cadet/cadet_protocol.h
+ * @brief P2P messages used by CADET
+ * @author Bartlomiej Polot
+ * @author Christian Grothoff
+ */
+
+#ifndef CADET_PROTOCOL_H_
+#define CADET_PROTOCOL_H_
+
+/**
+ * At best, enable when debugging #5328!
+ */
+#define DEBUG_KX 0
+#if DEBUG_KX
+#warning NEVER run this in production! KX debugging is on!
+#endif
+
+#include "platform.h"
+#include "gnunet_util_lib.h"
+#include "cadet.h"
+
+#ifdef __cplusplus
+
+struct GNUNET_CADET_TunnelMessage;
+extern "C"
+{
+#if 0
+/* keep Emacsens' auto-indent happy */
+}
+#endif
+#endif
+
+/******************************************************************************/
+/********************      CADET NETWORK MESSAGES     **************************/
+/******************************************************************************/
+
+GNUNET_NETWORK_STRUCT_BEGIN
+
+
+/******************************************************************************/
+/*****************************   CONNECTION  **********************************/
+/******************************************************************************/
+
+
+/**
+ * Message for cadet connection creation.
+ */
+struct GNUNET_CADET_ConnectionCreateMessage
+{
+  /**
+   * Type: #GNUNET_MESSAGE_TYPE_CADET_CONNECTION_CREATE
+   *
+   * Size: sizeof (struct GNUNET_CADET_ConnectionCreateMessage) +
+   *       path_length * sizeof (struct GNUNET_PeerIdentity)
+   */
+  struct GNUNET_MessageHeader header;
+
+  /**
+   * Connection options in network byte order.
+   * #GNUNET_CADET_OPTION_DEFAULT for buffered;
+   * #GNUNET_CADET_OPTION_NOBUFFER for unbuffered.
+   * Other flags are ignored and should not be set at this level.
+   */
+  uint32_t options GNUNET_PACKED;
+
+  /**
+   * This flag indicates the peer sending the connection create
+   * meassage likes to trigger a KX handshake.
+   */
+  int has_monotime;
+
+  /**
+   *  This monotonic time is set, if a peer likes to trigger a KX, but is not
+   *  the peer that should start the KX. (xrs,t3ss)
+   */
+  struct GNUNET_TIME_AbsoluteNBO monotime;
+
+  /**
+   *  We sign the monotime. The receiving peer can check the signature, to verify
+   *  the sending peer.
+   */
+  struct GNUNET_CRYPTO_EddsaSignature monotime_sig;
+
+  /**
+   * ID of the connection
+   */
+  struct GNUNET_CADET_ConnectionTunnelIdentifier cid;
+
+  /**
+   * path_length structs defining the *whole* path from the origin [0] to the
+   * final destination [path_length-1].
+   */
+  /* struct GNUNET_PeerIdentity peers[path_length]; */
+};
+
+
+/**
+ * Message for ack'ing a connection
+ */
+struct GNUNET_CADET_ConnectionCreateAckMessage
+{
+  /**
+   * Type: #GNUNET_MESSAGE_TYPE_CADET_CONNECTION_CREATE_ACK
+   */
+  struct GNUNET_MessageHeader header;
+
+  /**
+   * For alignment.
+   */
+  uint32_t reserved GNUNET_PACKED;
+
+  /**
+   * ID of the connection.
+   */
+  struct GNUNET_CADET_ConnectionTunnelIdentifier cid;
+};
+
+
+/**
+ * Message for notifying a disconnection in a path
+ */
+struct GNUNET_CADET_ConnectionBrokenMessage
+{
+  /**
+   * Type: #GNUNET_MESSAGE_TYPE_CADET_CONNECTION_BROKEN.
+   */
+  struct GNUNET_MessageHeader header;
+
+  /**
+   * For alignment.
+   */
+  uint32_t reserved GNUNET_PACKED;
+
+  /**
+   * ID of the connection.
+   */
+  struct GNUNET_CADET_ConnectionTunnelIdentifier cid;
+
+  /**
+   * ID of the endpoint
+   */
+  struct GNUNET_PeerIdentity peer1;
+
+  /**
+   * ID of the endpoint
+   */
+  struct GNUNET_PeerIdentity peer2;
+};
+
+
+/**
+ * Message to destroy a connection.
+ */
+struct GNUNET_CADET_ConnectionDestroyMessage
+{
+  /**
+   * Type: #GNUNET_MESSAGE_TYPE_CADET_CONNECTION_DESTROY
+   */
+  struct GNUNET_MessageHeader header;
+
+  /**
+   * For alignment.
+   */
+  uint32_t reserved GNUNET_PACKED;
+
+  /**
+   * ID of the connection.
+   */
+  struct GNUNET_CADET_ConnectionTunnelIdentifier cid;
+};
+
+
+/******************************************************************************/
+/*******************************   TUNNEL   ***********************************/
+/******************************************************************************/
+
+/**
+ * Unique identifier (counter) for an encrypted message in a channel.
+ * Used to match #GNUNET_MESSAGE_TYPE_CADET_CONNECTION_HOP_BY_HOP_ENCRYPTED_ACK
+ * and  #GNUNET_MESSAGE_TYPE_CADET_TUNNEL_ENCRYPTED_POLL messages
+ * against the respective  #GNUNET_MESSAGE_TYPE_CADET_TUNNEL_ENCRYPTED
+ * messages.
+ */
+struct CadetEncryptedMessageIdentifier
+{
+  /**
+   * This number is incremented by one per message. It may wrap around.
+   * In network byte order.
+   */
+  uint32_t pid GNUNET_PACKED;
+};
+
+
+/**
+ * Flags to be used in GNUNET_CADET_KX.
+ */
+enum GNUNET_CADET_KX_Flags
+{
+  /**
+   * Should the peer reply with its KX details?
+   */
+  GNUNET_CADET_KX_FLAG_NONE = 0,
+
+  /**
+   * The peer should reply with its KX details?
+   */
+  GNUNET_CADET_KX_FLAG_FORCE_REPLY = 1
+};
+
+
+/**
+ * Message for a Key eXchange for a tunnel.
+ */
+struct GNUNET_CADET_TunnelKeyExchangeMessage
+{
+  /**
+   * Type: #GNUNET_MESSAGE_TYPE_CADET_TUNNEL_KX or
+   * #GNUNET_MESSAGE_TYPE_CADET_TUNNEL_KX_AUTH as part
+   * of `struct GNUNET_CADET_TunnelKeyExchangeAuthMessage`.
+   */
+  struct GNUNET_MessageHeader header;
+
+  /**
+   * Flags for the key exchange in NBO, based on
+   * `enum GNUNET_CADET_KX_Flags`.
+   */
+  uint32_t flags GNUNET_PACKED;
+
+  /**
+   * ID of the connection.
+   */
+  struct GNUNET_CADET_ConnectionTunnelIdentifier cid;
+
+  /**
+   * Sender's ephemeral public ECC key encoded in a
+   * format suitable for network transmission, as created
+   * using 'gcry_sexp_sprint'.
+   */
+  struct GNUNET_CRYPTO_EcdhePublicKey ephemeral_key;
+
+#if DEBUG_KX
+  /**
+   * Sender's ephemeral public ECC key encoded in a
+   * format suitable for network transmission, as created
+   * using 'gcry_sexp_sprint'.
+   */
+  struct GNUNET_CRYPTO_EcdhePrivateKey ephemeral_key_XXX; // for debugging KX-crypto!
+
+  /**
+   * Sender's ephemeral public ECC key encoded in a
+   * format suitable for network transmission, as created
+   * using 'gcry_sexp_sprint'.
+   */
+  struct GNUNET_CRYPTO_EddsaPrivateKey private_key_XXX; // for debugging KX-crypto!
+#endif
+
+  /**
+   * Sender's next ephemeral public ECC key encoded in a
+   * format suitable for network transmission, as created
+   * using 'gcry_sexp_sprint'.
+   */
+  struct GNUNET_CRYPTO_EcdhePublicKey ratchet_key;
+};
+
+
+/**
+ * Message for a Key eXchange for a tunnel, with authentication.
+ * Used as a response to the initial KX as well as for rekeying.
+ */
+struct GNUNET_CADET_TunnelKeyExchangeAuthMessage
+{
+  /**
+   * Message header with key material.
+   */
+  struct GNUNET_CADET_TunnelKeyExchangeMessage kx;
+
+#if DEBUG_KX
+  /**
+   * Received ephemeral public ECC key encoded in a
+   * format suitable for network transmission, as created
+   * using 'gcry_sexp_sprint'.
+   */
+  struct GNUNET_CRYPTO_EcdhePublicKey r_ephemeral_key_XXX; // for debugging KX-crypto!
+#endif
+
+  /**
+   * KDF-proof that sender could compute the 3-DH, used in lieu of a
+   * signature or payload data.
+   */
+  struct GNUNET_HashCode auth;
+};
+
+
+/**
+ * Encrypted axolotl header with numbers that identify which
+ * keys in which ratchet are to be used to decrypt the body.
+ */
+struct GNUNET_CADET_AxHeader
+{
+  /**
+   * Number of messages sent with the current ratchet key.
+   */
+  uint32_t Ns GNUNET_PACKED;
+
+  /**
+   * Number of messages sent with the previous ratchet key.
+   */
+  uint32_t PNs GNUNET_PACKED;
+
+  /**
+   * Current ratchet key.
+   */
+  struct GNUNET_CRYPTO_EcdhePublicKey DHRs;
+};
+
+
+/**
+ * Axolotl-encrypted tunnel message with application payload.
+ */
+struct GNUNET_CADET_TunnelEncryptedMessage
+{
+  /**
+   * Type: #GNUNET_MESSAGE_TYPE_CADET_TUNNEL_ENCRYPTED
+   */
+  struct GNUNET_MessageHeader header;
+
+  /**
+   * 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.
+   */
+};
+
+
+/******************************************************************************/
+/*******************************   CHANNEL  ***********************************/
+/******************************************************************************/
+
+
+/**
+ * Message to create a Channel.
+ */
+struct GNUNET_CADET_ChannelOpenMessage
+{
+  /**
+   * Type: #GNUNET_MESSAGE_TYPE_CADET_CHANNEL_OPEN
+   */
+  struct GNUNET_MessageHeader header;
+
+  /**
+   * Channel options.
+   */
+  uint32_t opt GNUNET_PACKED;
+
+  /**
+   * Hash of destination port and listener.
+   */
+  struct GNUNET_HashCode h_port;
+
+  /**
+   * ID of the channel within the tunnel.
+   */
+  struct GNUNET_CADET_ChannelTunnelNumber ctn;
+};
+
+
+/**
+ * Message to acknowledge opening a channel of type
+ * #GNUNET_MESSAGE_TYPE_CADET_CHANNEL_OPEN_ACK.
+ */
+struct GNUNET_CADET_ChannelOpenAckMessage
+{
+  /**
+   * Type: #GNUNET_MESSAGE_TYPE_CADET_CHANNEL_OPEN_ACK
+   */
+  struct GNUNET_MessageHeader header;
+
+  /**
+   * For alignment.
+   */
+  uint32_t reserved GNUNET_PACKED;
+
+  /**
+   * ID of the channel
+   */
+  struct GNUNET_CADET_ChannelTunnelNumber ctn;
+
+  /**
+   * Port number of the channel, used to prove to the
+   * initiator that the receiver knows the port.
+   */
+  struct GNUNET_HashCode port;
+};
+
+
+/**
+ * Message to destroy a channel of type
+ * #GNUNET_MESSAGE_TYPE_CADET_CHANNEL_DESTROY.
+ */
+struct GNUNET_CADET_ChannelDestroyMessage
+{
+  /**
+   * Type: #GNUNET_MESSAGE_TYPE_CADET_CHANNEL_DESTROY
+   */
+  struct GNUNET_MessageHeader header;
+
+  /**
+   * For alignment.
+   */
+  uint32_t reserved GNUNET_PACKED;
+
+  /**
+   * ID of the channel
+   */
+  struct GNUNET_CADET_ChannelTunnelNumber ctn;
+};
+
+
+/**
+ * Number used to uniquely identify messages in a CADET Channel.
+ */
+struct ChannelMessageIdentifier
+{
+  /**
+   * Unique ID of the message, cycles around, in NBO.
+   */
+  uint32_t mid GNUNET_PACKED;
+};
+
+
+/**
+ * Message for cadet data traffic.
+ */
+struct GNUNET_CADET_ChannelAppDataMessage
+{
+  /**
+   * Type: #GNUNET_MESSAGE_TYPE_CADET_CHANNEL_APP_DATA.
+   */
+  struct GNUNET_MessageHeader header;
+
+  /**
+   * Unique ID of the payload message.
+   */
+  struct ChannelMessageIdentifier mid;
+
+  /**
+   * ID of the channel
+   */
+  struct GNUNET_CADET_ChannelTunnelNumber ctn;
+
+  /**
+   * Payload follows
+   */
+};
+
+
+/**
+ * Message to acknowledge end-to-end data.
+ */
+struct GNUNET_CADET_ChannelDataAckMessage
+{
+  /**
+   * Type: #GNUNET_MESSAGE_TYPE_CADET_CHANNEL_APP_DATA_ACK
+   */
+  struct GNUNET_MessageHeader header;
+
+  /**
+   * ID of the channel
+   */
+  struct GNUNET_CADET_ChannelTunnelNumber ctn;
+
+  /**
+   * Bitfield of already-received newer messages.  Note that bit 0
+   * corresponds to @e mid + 1.
+   *
+   * pid +  0 @ LSB
+   * pid + 63 @ MSB
+   */
+  uint64_t futures GNUNET_PACKED;
+
+  /**
+   * Next message ID expected.
+   */
+  struct ChannelMessageIdentifier mid;
+};
+
+
+GNUNET_NETWORK_STRUCT_END
+
+#if 0                           /* keep Emacsens' auto-indent happy */
+{
+#endif
+#ifdef __cplusplus
+}
+#endif
+
+/* ifndef CADET_PROTOCOL_H */
+#endif
+/* end of cadet_protocol.h */