2 This file is part of GNUnet.
3 Copyright (C) 2013, 2017 GNUnet e.V.
5 GNUnet is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published
7 by the Free Software Foundation; either version 3, or (at your
8 option) any later version.
10 GNUnet is distributed in the hope that it will be useful, but
11 WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 General Public License for more details.
15 You should have received a copy of the GNU General Public License
16 along with GNUnet; see the file COPYING. If not, write to the
17 Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
18 Boston, MA 02110-1301, USA.
21 * @file cadet/gnunet-service-cadet-new_tunnels.c
22 * @brief Information we track per tunnel.
23 * @author Bartlomiej Polot
24 * @author Christian Grothoff
27 * - proper connection evaluation during connection management:
28 * + consider quality (or quality spread?) of current connection set
29 * when deciding how often to do maintenance
30 * + interact with PEER to drive DHT GET/PUT operations based
31 * on how much we like our connections
34 #include "gnunet_util_lib.h"
35 #include "gnunet_statistics_service.h"
36 #include "gnunet_signatures.h"
37 #include "gnunet-service-cadet-new.h"
38 #include "cadet_protocol.h"
39 #include "gnunet-service-cadet-new_channel.h"
40 #include "gnunet-service-cadet-new_connection.h"
41 #include "gnunet-service-cadet-new_tunnels.h"
42 #include "gnunet-service-cadet-new_peer.h"
43 #include "gnunet-service-cadet-new_paths.h"
46 #define LOG(level, ...) GNUNET_log_from(level,"cadet-tun",__VA_ARGS__)
49 * How often do we try to decrypt payload with unverified key
50 * material? Used to limit CPU increase upon receiving bogus
53 #define MAX_UNVERIFIED_ATTEMPTS 16
56 * How long do we wait until tearing down an idle tunnel?
58 #define IDLE_DESTROY_DELAY GNUNET_TIME_relative_multiply(GNUNET_TIME_UNIT_SECONDS, 90)
61 * How long do we wait initially before retransmitting the KX?
62 * TODO: replace by 2 RTT if/once we have connection-level RTT data!
64 #define INITIAL_KX_RETRY_DELAY GNUNET_TIME_relative_multiply(GNUNET_TIME_UNIT_MILLISECONDS, 250)
67 * Maximum number of skipped keys we keep in memory per tunnel.
69 #define MAX_SKIPPED_KEYS 64
72 * Maximum number of keys (and thus ratchet steps) we are willing to
73 * skip before we decide this is either a bogus packet or a DoS-attempt.
75 #define MAX_KEY_GAP 256
79 * Struct to old keys for skipped messages while advancing the Axolotl ratchet.
81 struct CadetTunnelSkippedKey
86 struct CadetTunnelSkippedKey *next;
91 struct CadetTunnelSkippedKey *prev;
94 * When was this key stored (for timeout).
96 struct GNUNET_TIME_Absolute timestamp;
101 struct GNUNET_CRYPTO_SymmetricSessionKey HK;
106 struct GNUNET_CRYPTO_SymmetricSessionKey MK;
109 * Key number for a given HK.
116 * Axolotl data, according to https://github.com/trevp/axolotl/wiki .
118 struct CadetTunnelAxolotl
121 * A (double linked) list of stored message keys and associated header keys
122 * for "skipped" messages, i.e. messages that have not been
123 * received despite the reception of more recent messages, (head).
125 struct CadetTunnelSkippedKey *skipped_head;
128 * Skipped messages' keys DLL, tail.
130 struct CadetTunnelSkippedKey *skipped_tail;
133 * 32-byte root key which gets updated by DH ratchet.
135 struct GNUNET_CRYPTO_SymmetricSessionKey RK;
138 * 32-byte header key (currently used for sending).
140 struct GNUNET_CRYPTO_SymmetricSessionKey HKs;
143 * 32-byte header key (currently used for receiving)
145 struct GNUNET_CRYPTO_SymmetricSessionKey HKr;
148 * 32-byte next header key (for sending), used once the
149 * ratchet advances. We are sure that the sender has this
150 * key as well only after @e ratchet_allowed is #GNUNET_YES.
152 struct GNUNET_CRYPTO_SymmetricSessionKey NHKs;
155 * 32-byte next header key (for receiving). To be tried
156 * when decrypting with @e HKr fails and thus the sender
157 * may have advanced the ratchet.
159 struct GNUNET_CRYPTO_SymmetricSessionKey NHKr;
162 * 32-byte chain keys (used for forward-secrecy) for
163 * sending messages. Updated for every message.
165 struct GNUNET_CRYPTO_SymmetricSessionKey CKs;
168 * 32-byte chain keys (used for forward-secrecy) for
169 * receiving messages. Updated for every message. If
170 * messages are skipped, the respective derived MKs
171 * (and the current @HKr) are kept in the @e skipped_head DLL.
173 struct GNUNET_CRYPTO_SymmetricSessionKey CKr;
176 * ECDH for key exchange (A0 / B0).
178 struct GNUNET_CRYPTO_EcdhePrivateKey kx_0;
181 * ECDH Ratchet key (our private key in the current DH).
183 struct GNUNET_CRYPTO_EcdhePrivateKey DHRs;
186 * ECDH Ratchet key (other peer's public key in the current DH).
188 struct GNUNET_CRYPTO_EcdhePublicKey DHRr;
191 * Time when the current ratchet expires and a new one is triggered
192 * (if @e ratchet_allowed is #GNUNET_YES).
194 struct GNUNET_TIME_Absolute ratchet_expiration;
197 * Number of elements in @a skipped_head <-> @a skipped_tail.
199 unsigned int skipped;
202 * Message number (reset to 0 with each new ratchet, next message to send).
207 * Message number (reset to 0 with each new ratchet, next message to recv).
212 * Previous message numbers (# of msgs sent under prev ratchet)
217 * True (#GNUNET_YES) if we have to send a new ratchet key in next msg.
222 * True (#GNUNET_YES) if we have received a message from the
223 * other peer that uses the keys from our last ratchet step.
224 * This implies that we are again allowed to advance the ratchet,
225 * otherwise we have to wait until the other peer sees our current
226 * ephemeral key and advances first.
228 * #GNUNET_NO if we have advanced the ratched but lack any evidence
229 * that the other peer has noticed this.
234 * Number of messages recieved since our last ratchet advance.
236 * If this counter = 0, we cannot send a new ratchet key in the next
239 * If this counter > 0, we could (but don't have to) send a new key.
241 * Once the @e ratchet_counter is larger than
242 * #ratchet_messages (or @e ratchet_expiration time has past), and
243 * @e ratchet_allowed is #GNUNET_YES, we advance the ratchet.
245 unsigned int ratchet_counter;
251 * Struct used to save messages in a non-ready tunnel to send once connected.
253 struct CadetTunnelQueueEntry
256 * We are entries in a DLL
258 struct CadetTunnelQueueEntry *next;
261 * We are entries in a DLL
263 struct CadetTunnelQueueEntry *prev;
266 * Tunnel these messages belong in.
268 struct CadetTunnel *t;
271 * Continuation to call once sent (on the channel layer).
273 GCT_SendContinuation cont;
276 * Closure for @c cont.
281 * Envelope of message to send follows.
283 struct GNUNET_MQ_Envelope *env;
286 * Where to put the connection identifier into the payload
287 * of the message in @e env once we have it?
289 struct GNUNET_CADET_ConnectionTunnelIdentifier *cid;
294 * Struct containing all information regarding a tunnel to a peer.
299 * Destination of the tunnel.
301 struct CadetPeer *destination;
304 * Peer's ephemeral key, to recreate @c e_key and @c d_key when own
305 * ephemeral key changes.
307 struct GNUNET_CRYPTO_EcdhePublicKey peers_ephemeral_key;
310 * Encryption ("our") key. It is only "confirmed" if kx_ctx is NULL.
312 struct GNUNET_CRYPTO_SymmetricSessionKey e_key;
315 * Decryption ("their") key. It is only "confirmed" if kx_ctx is NULL.
317 struct GNUNET_CRYPTO_SymmetricSessionKey d_key;
322 struct CadetTunnelAxolotl ax;
325 * Unverified Axolotl info, used only if we got a fresh KX (not a
326 * KX_AUTH) while our end of the tunnel was still up. In this case,
327 * we keep the fresh KX around but do not put it into action until
328 * we got encrypted payload that assures us of the authenticity of
331 struct CadetTunnelAxolotl *unverified_ax;
334 * Task scheduled if there are no more channels using the tunnel.
336 struct GNUNET_SCHEDULER_Task *destroy_task;
339 * Task to trim connections if too many are present.
341 struct GNUNET_SCHEDULER_Task *maintain_connections_task;
344 * Task to send messages from queue (if possible).
346 struct GNUNET_SCHEDULER_Task *send_task;
349 * Task to trigger KX.
351 struct GNUNET_SCHEDULER_Task *kx_task;
354 * Tokenizer for decrypted messages.
356 struct GNUNET_MessageStreamTokenizer *mst;
359 * Dispatcher for decrypted messages only (do NOT use for sending!).
361 struct GNUNET_MQ_Handle *mq;
364 * DLL of ready connections that are actively used to reach the destination peer.
366 struct CadetTConnection *connection_ready_head;
369 * DLL of ready connections that are actively used to reach the destination peer.
371 struct CadetTConnection *connection_ready_tail;
374 * DLL of connections that we maintain that might be used to reach the destination peer.
376 struct CadetTConnection *connection_busy_head;
379 * DLL of connections that we maintain that might be used to reach the destination peer.
381 struct CadetTConnection *connection_busy_tail;
384 * Channels inside this tunnel. Maps
385 * `struct GNUNET_CADET_ChannelTunnelNumber` to a `struct CadetChannel`.
387 struct GNUNET_CONTAINER_MultiHashMap32 *channels;
390 * Channel ID for the next created channel in this tunnel.
392 struct GNUNET_CADET_ChannelTunnelNumber next_ctn;
395 * Queued messages, to transmit once tunnel gets connected.
397 struct CadetTunnelQueueEntry *tq_head;
400 * Queued messages, to transmit once tunnel gets connected.
402 struct CadetTunnelQueueEntry *tq_tail;
405 * Identification of the connection from which we are currently processing
406 * a message. Only valid (non-NULL) during #handle_decrypted() and the
407 * handle-*()-functions called from our @e mq during that function.
409 struct CadetTConnection *current_ct;
412 * How long do we wait until we retry the KX?
414 struct GNUNET_TIME_Relative kx_retry_delay;
417 * When do we try the next KX?
419 struct GNUNET_TIME_Absolute next_kx_attempt;
422 * Number of connections in the @e connection_ready_head DLL.
424 unsigned int num_ready_connections;
427 * Number of connections in the @e connection_busy_head DLL.
429 unsigned int num_busy_connections;
432 * How often have we tried and failed to decrypt a message using
433 * the unverified KX material from @e unverified_ax? Used to
434 * stop trying after #MAX_UNVERIFIED_ATTEMPTS.
436 unsigned int unverified_attempts;
439 * Number of entries in the @e tq_head DLL.
444 * State of the tunnel encryption.
446 enum CadetTunnelEState estate;
449 * Force triggering KX_AUTH independent of @e estate.
451 int kx_auth_requested;
457 * Connection @a ct is now unready, clear it's ready flag
458 * and move it from the ready DLL to the busy DLL.
460 * @param ct connection to move to unready status
463 mark_connection_unready (struct CadetTConnection *ct)
465 struct CadetTunnel *t = ct->t;
467 GNUNET_assert (GNUNET_YES == ct->is_ready);
468 GNUNET_CONTAINER_DLL_remove (t->connection_ready_head,
469 t->connection_ready_tail,
471 GNUNET_assert (0 < t->num_ready_connections);
472 t->num_ready_connections--;
473 ct->is_ready = GNUNET_NO;
474 GNUNET_CONTAINER_DLL_insert (t->connection_busy_head,
475 t->connection_busy_tail,
477 t->num_busy_connections++;
482 * Get the static string for the peer this tunnel is directed.
486 * @return Static string the destination peer's ID.
489 GCT_2s (const struct CadetTunnel *t)
494 return "Tunnel(NULL)";
495 GNUNET_snprintf (buf,
498 GNUNET_i2s (GCP_get_id (t->destination)));
504 * Get string description for tunnel encryption state.
506 * @param es Tunnel state.
508 * @return String representation.
511 estate2s (enum CadetTunnelEState es)
517 case CADET_TUNNEL_KEY_UNINITIALIZED:
518 return "CADET_TUNNEL_KEY_UNINITIALIZED";
519 case CADET_TUNNEL_KEY_AX_RECV:
520 return "CADET_TUNNEL_KEY_AX_RECV";
521 case CADET_TUNNEL_KEY_AX_SENT:
522 return "CADET_TUNNEL_KEY_AX_SENT";
523 case CADET_TUNNEL_KEY_AX_SENT_AND_RECV:
524 return "CADET_TUNNEL_KEY_AX_SENT_AND_RECV";
525 case CADET_TUNNEL_KEY_AX_AUTH_SENT:
526 return "CADET_TUNNEL_KEY_AX_AUTH_SENT";
527 case CADET_TUNNEL_KEY_OK:
528 return "CADET_TUNNEL_KEY_OK";
530 GNUNET_snprintf (buf,
532 "%u (UNKNOWN STATE)",
540 * Return the peer to which this tunnel goes.
543 * @return the destination of the tunnel
546 GCT_get_destination (struct CadetTunnel *t)
548 return t->destination;
553 * Count channels of a tunnel.
555 * @param t Tunnel on which to count.
557 * @return Number of channels.
560 GCT_count_channels (struct CadetTunnel *t)
562 return GNUNET_CONTAINER_multihashmap32_size (t->channels);
567 * Lookup a channel by its @a ctn.
569 * @param t tunnel to look in
570 * @param ctn number of channel to find
571 * @return NULL if channel does not exist
573 struct CadetChannel *
574 lookup_channel (struct CadetTunnel *t,
575 struct GNUNET_CADET_ChannelTunnelNumber ctn)
577 return GNUNET_CONTAINER_multihashmap32_get (t->channels,
583 * Count all created connections of a tunnel. Not necessarily ready connections!
585 * @param t Tunnel on which to count.
587 * @return Number of connections created, either being established or ready.
590 GCT_count_any_connections (const struct CadetTunnel *t)
592 return t->num_ready_connections + t->num_busy_connections;
597 * Find first connection that is ready in the list of
598 * our connections. Picks ready connections round-robin.
600 * @param t tunnel to search
601 * @return NULL if we have no connection that is ready
603 static struct CadetTConnection *
604 get_ready_connection (struct CadetTunnel *t)
606 struct CadetTConnection *hd = t->connection_ready_head;
608 GNUNET_assert ( (NULL == hd) ||
609 (GNUNET_YES == hd->is_ready) );
615 * Get the encryption state of a tunnel.
619 * @return Tunnel's encryption state.
621 enum CadetTunnelEState
622 GCT_get_estate (struct CadetTunnel *t)
629 * Called when either we have a new connection, or a new message in the
630 * queue, or some existing connection has transmission capacity. Looks
631 * at our message queue and if there is a message, picks a connection
634 * @param cls the `struct CadetTunnel` to process messages on
637 trigger_transmissions (void *cls);
640 /* ************************************** start core crypto ***************************** */
644 * Create a new Axolotl ephemeral (ratchet) key.
646 * @param ax key material to update
649 new_ephemeral (struct CadetTunnelAxolotl *ax)
651 LOG (GNUNET_ERROR_TYPE_DEBUG,
652 "Creating new ephemeral ratchet key (DHRs)\n");
653 GNUNET_assert (GNUNET_OK ==
654 GNUNET_CRYPTO_ecdhe_key_create2 (&ax->DHRs));
661 * @param plaintext Content to HMAC.
662 * @param size Size of @c plaintext.
663 * @param iv Initialization vector for the message.
664 * @param key Key to use.
665 * @param hmac[out] Destination to store the HMAC.
668 t_hmac (const void *plaintext,
671 const struct GNUNET_CRYPTO_SymmetricSessionKey *key,
672 struct GNUNET_ShortHashCode *hmac)
674 static const char ctx[] = "cadet authentication key";
675 struct GNUNET_CRYPTO_AuthKey auth_key;
676 struct GNUNET_HashCode hash;
678 GNUNET_CRYPTO_hmac_derive_key (&auth_key,
684 /* Two step: GNUNET_ShortHash is only 256 bits,
685 GNUNET_HashCode is 512, so we truncate. */
686 GNUNET_CRYPTO_hmac (&auth_key,
699 * @param key Key to use.
700 * @param[out] hash Resulting HMAC.
701 * @param source Source key material (data to HMAC).
702 * @param len Length of @a source.
705 t_ax_hmac_hash (const struct GNUNET_CRYPTO_SymmetricSessionKey *key,
706 struct GNUNET_HashCode *hash,
710 static const char ctx[] = "axolotl HMAC-HASH";
711 struct GNUNET_CRYPTO_AuthKey auth_key;
713 GNUNET_CRYPTO_hmac_derive_key (&auth_key,
717 GNUNET_CRYPTO_hmac (&auth_key,
725 * Derive a symmetric encryption key from an HMAC-HASH.
727 * @param key Key to use for the HMAC.
728 * @param[out] out Key to generate.
729 * @param source Source key material (data to HMAC).
730 * @param len Length of @a source.
733 t_hmac_derive_key (const struct GNUNET_CRYPTO_SymmetricSessionKey *key,
734 struct GNUNET_CRYPTO_SymmetricSessionKey *out,
738 static const char ctx[] = "axolotl derive key";
739 struct GNUNET_HashCode h;
745 GNUNET_CRYPTO_kdf (out, sizeof (*out),
753 * Encrypt data with the axolotl tunnel key.
755 * @param ax key material to use.
756 * @param dst Destination with @a size bytes for the encrypted data.
757 * @param src Source of the plaintext. Can overlap with @c dst, must contain @a size bytes
758 * @param size Size of the buffers at @a src and @a dst
761 t_ax_encrypt (struct CadetTunnelAxolotl *ax,
766 struct GNUNET_CRYPTO_SymmetricSessionKey MK;
767 struct GNUNET_CRYPTO_SymmetricInitializationVector iv;
770 ax->ratchet_counter++;
771 if ( (GNUNET_YES == ax->ratchet_allowed) &&
772 ( (ratchet_messages <= ax->ratchet_counter) ||
773 (0 == GNUNET_TIME_absolute_get_remaining (ax->ratchet_expiration).rel_value_us)) )
775 ax->ratchet_flag = GNUNET_YES;
777 if (GNUNET_YES == ax->ratchet_flag)
779 /* Advance ratchet */
780 struct GNUNET_CRYPTO_SymmetricSessionKey keys[3];
781 struct GNUNET_HashCode dh;
782 struct GNUNET_HashCode hmac;
783 static const char ctx[] = "axolotl ratchet";
788 /* RK, NHKs, CKs = KDF( HMAC-HASH(RK, DH(DHRs, DHRr)) ) */
789 GNUNET_CRYPTO_ecc_ecdh (&ax->DHRs,
792 t_ax_hmac_hash (&ax->RK,
796 GNUNET_CRYPTO_kdf (keys, sizeof (keys),
798 &hmac, sizeof (hmac),
806 ax->ratchet_flag = GNUNET_NO;
807 ax->ratchet_allowed = GNUNET_NO;
808 ax->ratchet_counter = 0;
809 ax->ratchet_expiration
810 = GNUNET_TIME_absolute_add (GNUNET_TIME_absolute_get(),
814 t_hmac_derive_key (&ax->CKs,
818 GNUNET_CRYPTO_symmetric_derive_iv (&iv,
823 out_size = GNUNET_CRYPTO_symmetric_encrypt (src,
828 GNUNET_assert (size == out_size);
829 t_hmac_derive_key (&ax->CKs,
837 * Decrypt data with the axolotl tunnel key.
839 * @param ax key material to use.
840 * @param dst Destination for the decrypted data, must contain @a size bytes.
841 * @param src Source of the ciphertext. Can overlap with @c dst, must contain @a size bytes.
842 * @param size Size of the @a src and @a dst buffers
845 t_ax_decrypt (struct CadetTunnelAxolotl *ax,
850 struct GNUNET_CRYPTO_SymmetricSessionKey MK;
851 struct GNUNET_CRYPTO_SymmetricInitializationVector iv;
854 t_hmac_derive_key (&ax->CKr,
858 GNUNET_CRYPTO_symmetric_derive_iv (&iv,
862 GNUNET_assert (size >= sizeof (struct GNUNET_MessageHeader));
863 out_size = GNUNET_CRYPTO_symmetric_decrypt (src,
868 GNUNET_assert (out_size == size);
869 t_hmac_derive_key (&ax->CKr,
877 * Encrypt header with the axolotl header key.
879 * @param ax key material to use.
880 * @param[in|out] msg Message whose header to encrypt.
883 t_h_encrypt (struct CadetTunnelAxolotl *ax,
884 struct GNUNET_CADET_TunnelEncryptedMessage *msg)
886 struct GNUNET_CRYPTO_SymmetricInitializationVector iv;
889 GNUNET_CRYPTO_symmetric_derive_iv (&iv,
893 out_size = GNUNET_CRYPTO_symmetric_encrypt (&msg->ax_header,
894 sizeof (struct GNUNET_CADET_AxHeader),
898 GNUNET_assert (sizeof (struct GNUNET_CADET_AxHeader) == out_size);
903 * Decrypt header with the current axolotl header key.
905 * @param ax key material to use.
906 * @param src Message whose header to decrypt.
907 * @param dst Where to decrypt header to.
910 t_h_decrypt (struct CadetTunnelAxolotl *ax,
911 const struct GNUNET_CADET_TunnelEncryptedMessage *src,
912 struct GNUNET_CADET_TunnelEncryptedMessage *dst)
914 struct GNUNET_CRYPTO_SymmetricInitializationVector iv;
917 GNUNET_CRYPTO_symmetric_derive_iv (&iv,
921 out_size = GNUNET_CRYPTO_symmetric_decrypt (&src->ax_header.Ns,
922 sizeof (struct GNUNET_CADET_AxHeader),
926 GNUNET_assert (sizeof (struct GNUNET_CADET_AxHeader) == out_size);
931 * Delete a key from the list of skipped keys.
933 * @param ax key material to delete @a key from.
934 * @param key Key to delete.
937 delete_skipped_key (struct CadetTunnelAxolotl *ax,
938 struct CadetTunnelSkippedKey *key)
940 GNUNET_CONTAINER_DLL_remove (ax->skipped_head,
949 * Decrypt and verify data with the appropriate tunnel key and verify that the
950 * data has not been altered since it was sent by the remote peer.
952 * @param ax key material to use.
953 * @param dst Destination for the plaintext.
954 * @param src Source of the message. Can overlap with @c dst.
955 * @param size Size of the message.
956 * @return Size of the decrypted data, -1 if an error was encountered.
959 try_old_ax_keys (struct CadetTunnelAxolotl *ax,
961 const struct GNUNET_CADET_TunnelEncryptedMessage *src,
964 struct CadetTunnelSkippedKey *key;
965 struct GNUNET_ShortHashCode *hmac;
966 struct GNUNET_CRYPTO_SymmetricInitializationVector iv;
967 struct GNUNET_CADET_TunnelEncryptedMessage plaintext_header;
968 struct GNUNET_CRYPTO_SymmetricSessionKey *valid_HK;
974 LOG (GNUNET_ERROR_TYPE_DEBUG,
975 "Trying skipped keys\n");
976 hmac = &plaintext_header.hmac;
977 esize = size - sizeof (struct GNUNET_CADET_TunnelEncryptedMessage);
979 /* Find a correct Header Key */
981 for (key = ax->skipped_head; NULL != key; key = key->next)
983 t_hmac (&src->ax_header,
984 sizeof (struct GNUNET_CADET_AxHeader) + esize,
988 if (0 == memcmp (hmac,
999 /* Should've been checked in -cadet_connection.c handle_cadet_encrypted. */
1000 GNUNET_assert (size > sizeof (struct GNUNET_CADET_TunnelEncryptedMessage));
1001 len = size - sizeof (struct GNUNET_CADET_TunnelEncryptedMessage);
1002 GNUNET_assert (len >= sizeof (struct GNUNET_MessageHeader));
1004 /* Decrypt header */
1005 GNUNET_CRYPTO_symmetric_derive_iv (&iv,
1009 res = GNUNET_CRYPTO_symmetric_decrypt (&src->ax_header.Ns,
1010 sizeof (struct GNUNET_CADET_AxHeader),
1013 &plaintext_header.ax_header.Ns);
1014 GNUNET_assert (sizeof (struct GNUNET_CADET_AxHeader) == res);
1016 /* Find the correct message key */
1017 N = ntohl (plaintext_header.ax_header.Ns);
1018 while ( (NULL != key) &&
1021 if ( (NULL == key) ||
1022 (0 != memcmp (&key->HK,
1024 sizeof (*valid_HK))) )
1027 /* Decrypt payload */
1028 GNUNET_CRYPTO_symmetric_derive_iv (&iv,
1033 res = GNUNET_CRYPTO_symmetric_decrypt (&src[1],
1038 delete_skipped_key (ax,
1045 * Delete a key from the list of skipped keys.
1047 * @param ax key material to delete from.
1048 * @param HKr Header Key to use.
1051 store_skipped_key (struct CadetTunnelAxolotl *ax,
1052 const struct GNUNET_CRYPTO_SymmetricSessionKey *HKr)
1054 struct CadetTunnelSkippedKey *key;
1056 key = GNUNET_new (struct CadetTunnelSkippedKey);
1057 key->timestamp = GNUNET_TIME_absolute_get ();
1060 t_hmac_derive_key (&ax->CKr,
1064 t_hmac_derive_key (&ax->CKr,
1068 GNUNET_CONTAINER_DLL_insert (ax->skipped_head,
1077 * Stage skipped AX keys and calculate the message key.
1078 * Stores each HK and MK for skipped messages.
1080 * @param ax key material to use
1081 * @param HKr Header key.
1082 * @param Np Received meesage number.
1083 * @return #GNUNET_OK if keys were stored.
1084 * #GNUNET_SYSERR if an error ocurred (@a Np not expected).
1087 store_ax_keys (struct CadetTunnelAxolotl *ax,
1088 const struct GNUNET_CRYPTO_SymmetricSessionKey *HKr,
1094 LOG (GNUNET_ERROR_TYPE_DEBUG,
1095 "Storing skipped keys [%u, %u)\n",
1098 if (MAX_KEY_GAP < gap)
1100 /* Avoid DoS (forcing peer to do more than #MAX_KEY_GAP HMAC operations) */
1101 /* TODO: start new key exchange on return */
1102 GNUNET_break_op (0);
1103 LOG (GNUNET_ERROR_TYPE_WARNING,
1104 "Got message %u, expected %u+\n",
1107 return GNUNET_SYSERR;
1111 /* Delayed message: don't store keys, flag to try old keys. */
1112 return GNUNET_SYSERR;
1116 store_skipped_key (ax,
1119 while (ax->skipped > MAX_SKIPPED_KEYS)
1120 delete_skipped_key (ax,
1127 * Decrypt and verify data with the appropriate tunnel key and verify that the
1128 * data has not been altered since it was sent by the remote peer.
1130 * @param ax key material to use
1131 * @param dst Destination for the plaintext.
1132 * @param src Source of the message. Can overlap with @c dst.
1133 * @param size Size of the message.
1134 * @return Size of the decrypted data, -1 if an error was encountered.
1137 t_ax_decrypt_and_validate (struct CadetTunnelAxolotl *ax,
1139 const struct GNUNET_CADET_TunnelEncryptedMessage *src,
1142 struct GNUNET_ShortHashCode msg_hmac;
1143 struct GNUNET_HashCode hmac;
1144 struct GNUNET_CADET_TunnelEncryptedMessage plaintext_header;
1147 size_t esize; /* Size of encryped payload */
1149 esize = size - sizeof (struct GNUNET_CADET_TunnelEncryptedMessage);
1151 /* Try current HK */
1152 t_hmac (&src->ax_header,
1153 sizeof (struct GNUNET_CADET_AxHeader) + esize,
1156 if (0 != memcmp (&msg_hmac,
1160 static const char ctx[] = "axolotl ratchet";
1161 struct GNUNET_CRYPTO_SymmetricSessionKey keys[3]; /* RKp, NHKp, CKp */
1162 struct GNUNET_CRYPTO_SymmetricSessionKey HK;
1163 struct GNUNET_HashCode dh;
1164 struct GNUNET_CRYPTO_EcdhePublicKey *DHRp;
1167 t_hmac (&src->ax_header,
1168 sizeof (struct GNUNET_CADET_AxHeader) + esize,
1172 if (0 != memcmp (&msg_hmac,
1176 /* Try the skipped keys, if that fails, we're out of luck. */
1177 return try_old_ax_keys (ax,
1187 Np = ntohl (plaintext_header.ax_header.Ns);
1188 PNp = ntohl (plaintext_header.ax_header.PNs);
1189 DHRp = &plaintext_header.ax_header.DHRs;
1194 /* RKp, NHKp, CKp = KDF (HMAC-HASH (RK, DH (DHRp, DHRs))) */
1195 GNUNET_CRYPTO_ecc_ecdh (&ax->DHRs,
1198 t_ax_hmac_hash (&ax->RK,
1201 GNUNET_CRYPTO_kdf (keys, sizeof (keys),
1203 &hmac, sizeof (hmac),
1206 /* Commit "purported" keys */
1212 ax->ratchet_allowed = GNUNET_YES;
1219 Np = ntohl (plaintext_header.ax_header.Ns);
1220 PNp = ntohl (plaintext_header.ax_header.PNs);
1222 if ( (Np != ax->Nr) &&
1223 (GNUNET_OK != store_ax_keys (ax,
1227 /* Try the skipped keys, if that fails, we're out of luck. */
1228 return try_old_ax_keys (ax,
1244 * Our tunnel became ready for the first time, notify channels
1245 * that have been waiting.
1247 * @param cls our tunnel, not used
1248 * @param key unique ID of the channel, not used
1249 * @param value the `struct CadetChannel` to notify
1250 * @return #GNUNET_OK (continue to iterate)
1253 notify_tunnel_up_cb (void *cls,
1257 struct CadetChannel *ch = value;
1259 GCCH_tunnel_up (ch);
1265 * Change the tunnel encryption state.
1266 * If the encryption state changes to OK, stop the rekey task.
1268 * @param t Tunnel whose encryption state to change, or NULL.
1269 * @param state New encryption state.
1272 GCT_change_estate (struct CadetTunnel *t,
1273 enum CadetTunnelEState state)
1275 enum CadetTunnelEState old = t->estate;
1278 LOG (GNUNET_ERROR_TYPE_DEBUG,
1279 "%s estate changed from %s to %s\n",
1284 if ( (CADET_TUNNEL_KEY_OK != old) &&
1285 (CADET_TUNNEL_KEY_OK == t->estate) )
1287 if (NULL != t->kx_task)
1289 GNUNET_SCHEDULER_cancel (t->kx_task);
1292 /* notify all channels that have been waiting */
1293 GNUNET_CONTAINER_multihashmap32_iterate (t->channels,
1294 ¬ify_tunnel_up_cb,
1296 if (NULL != t->send_task)
1297 GNUNET_SCHEDULER_cancel (t->send_task);
1298 t->send_task = GNUNET_SCHEDULER_add_now (&trigger_transmissions,
1305 * Send a KX message.
1307 * @param t tunnel on which to send the KX_AUTH
1308 * @param ct Tunnel and connection on which to send the KX_AUTH, NULL if
1309 * we are to find one that is ready.
1310 * @param ax axolotl key context to use
1313 send_kx (struct CadetTunnel *t,
1314 struct CadetTConnection *ct,
1315 struct CadetTunnelAxolotl *ax)
1317 struct CadetConnection *cc;
1318 struct GNUNET_MQ_Envelope *env;
1319 struct GNUNET_CADET_TunnelKeyExchangeMessage *msg;
1320 enum GNUNET_CADET_KX_Flags flags;
1322 if ( (NULL == ct) ||
1323 (GNUNET_NO == ct->is_ready) )
1324 ct = get_ready_connection (t);
1327 LOG (GNUNET_ERROR_TYPE_DEBUG,
1328 "Wanted to send %s in state %s, but no connection is ready, deferring\n",
1330 estate2s (t->estate));
1331 t->next_kx_attempt = GNUNET_TIME_absolute_get ();
1335 LOG (GNUNET_ERROR_TYPE_DEBUG,
1336 "Sending KX on %s via %s in state %s\n",
1339 estate2s (t->estate));
1340 env = GNUNET_MQ_msg (msg,
1341 GNUNET_MESSAGE_TYPE_CADET_TUNNEL_KX);
1342 flags = GNUNET_CADET_KX_FLAG_FORCE_REPLY; /* always for KX */
1343 msg->flags = htonl (flags);
1344 msg->cid = *GCC_get_id (cc);
1345 GNUNET_CRYPTO_ecdhe_key_get_public (&ax->kx_0,
1346 &msg->ephemeral_key);
1347 GNUNET_CRYPTO_ecdhe_key_get_public (&ax->DHRs,
1349 mark_connection_unready (ct);
1350 t->kx_retry_delay = GNUNET_TIME_STD_BACKOFF (t->kx_retry_delay);
1351 t->next_kx_attempt = GNUNET_TIME_relative_to_absolute (t->kx_retry_delay);
1352 if (CADET_TUNNEL_KEY_UNINITIALIZED == t->estate)
1353 GCT_change_estate (t,
1354 CADET_TUNNEL_KEY_AX_SENT);
1355 else if (CADET_TUNNEL_KEY_AX_RECV == t->estate)
1356 GCT_change_estate (t,
1357 CADET_TUNNEL_KEY_AX_SENT_AND_RECV);
1364 * Send a KX_AUTH message.
1366 * @param t tunnel on which to send the KX_AUTH
1367 * @param ct Tunnel and connection on which to send the KX_AUTH, NULL if
1368 * we are to find one that is ready.
1369 * @param ax axolotl key context to use
1370 * @param force_reply Force the other peer to reply with a KX_AUTH message
1371 * (set if we would like to transmit right now, but cannot)
1374 send_kx_auth (struct CadetTunnel *t,
1375 struct CadetTConnection *ct,
1376 struct CadetTunnelAxolotl *ax,
1379 struct CadetConnection *cc;
1380 struct GNUNET_MQ_Envelope *env;
1381 struct GNUNET_CADET_TunnelKeyExchangeAuthMessage *msg;
1382 enum GNUNET_CADET_KX_Flags flags;
1384 if ( (NULL == ct) ||
1385 (GNUNET_NO == ct->is_ready) )
1386 ct = get_ready_connection (t);
1389 LOG (GNUNET_ERROR_TYPE_DEBUG,
1390 "Wanted to send KX_AUTH on %s, but no connection is ready, deferring\n",
1392 t->next_kx_attempt = GNUNET_TIME_absolute_get ();
1393 t->kx_auth_requested = GNUNET_YES; /* queue KX_AUTH independent of estate */
1396 t->kx_auth_requested = GNUNET_NO; /* clear flag */
1398 LOG (GNUNET_ERROR_TYPE_DEBUG,
1399 "Sending KX_AUTH on %s using %s\n",
1403 env = GNUNET_MQ_msg (msg,
1404 GNUNET_MESSAGE_TYPE_CADET_TUNNEL_KX_AUTH);
1405 flags = GNUNET_CADET_KX_FLAG_NONE;
1406 if (GNUNET_YES == force_reply)
1407 flags |= GNUNET_CADET_KX_FLAG_FORCE_REPLY;
1408 msg->kx.flags = htonl (flags);
1409 msg->kx.cid = *GCC_get_id (cc);
1410 GNUNET_CRYPTO_ecdhe_key_get_public (&ax->kx_0,
1411 &msg->kx.ephemeral_key);
1412 GNUNET_CRYPTO_ecdhe_key_get_public (&ax->DHRs,
1413 &msg->kx.ratchet_key);
1414 /* Compute authenticator (this is the main difference to #send_kx()) */
1415 GNUNET_CRYPTO_hash (&ax->RK,
1419 /* Compute when to be triggered again; actual job will
1420 be scheduled via #connection_ready_cb() */
1422 = GNUNET_TIME_STD_BACKOFF (t->kx_retry_delay);
1424 = GNUNET_TIME_relative_to_absolute (t->kx_retry_delay);
1426 /* Send via cc, mark it as unready */
1427 mark_connection_unready (ct);
1429 /* Update state machine, unless we are already OK */
1430 if (CADET_TUNNEL_KEY_OK != t->estate)
1431 GCT_change_estate (t,
1432 CADET_TUNNEL_KEY_AX_AUTH_SENT);
1440 * Cleanup state used by @a ax.
1442 * @param ax state to free, but not memory of @a ax itself
1445 cleanup_ax (struct CadetTunnelAxolotl *ax)
1447 while (NULL != ax->skipped_head)
1448 delete_skipped_key (ax,
1450 GNUNET_assert (0 == ax->skipped);
1451 GNUNET_CRYPTO_ecdhe_key_clear (&ax->kx_0);
1452 GNUNET_CRYPTO_ecdhe_key_clear (&ax->DHRs);
1457 * Update our Axolotl key state based on the KX data we received.
1458 * Computes the new chain keys, and root keys, etc, and also checks
1459 * wether this is a replay of the current chain.
1461 * @param[in|out] axolotl chain key state to recompute
1462 * @param pid peer identity of the other peer
1463 * @param ephemeral_key ephemeral public key of the other peer
1464 * @param ratchet_key senders next ephemeral public key
1465 * @return #GNUNET_OK on success, #GNUNET_NO if the resulting
1466 * root key is already in @a ax and thus the KX is useless;
1467 * #GNUNET_SYSERR on hard errors (i.e. @a pid is #my_full_id)
1470 update_ax_by_kx (struct CadetTunnelAxolotl *ax,
1471 const struct GNUNET_PeerIdentity *pid,
1472 const struct GNUNET_CRYPTO_EcdhePublicKey *ephemeral_key,
1473 const struct GNUNET_CRYPTO_EcdhePublicKey *ratchet_key)
1475 struct GNUNET_HashCode key_material[3];
1476 struct GNUNET_CRYPTO_SymmetricSessionKey keys[5];
1477 const char salt[] = "CADET Axolotl salt";
1480 if (0 > GNUNET_CRYPTO_cmp_peer_identity (&my_full_id,
1482 am_I_alice = GNUNET_YES;
1483 else if (0 < GNUNET_CRYPTO_cmp_peer_identity (&my_full_id,
1485 am_I_alice = GNUNET_NO;
1488 GNUNET_break_op (0);
1489 return GNUNET_SYSERR;
1492 if (0 == memcmp (&ax->DHRr,
1494 sizeof (*ratchet_key)))
1496 LOG (GNUNET_ERROR_TYPE_DEBUG,
1497 "Ratchet key already known. Ignoring KX.\n");
1501 ax->DHRr = *ratchet_key;
1504 if (GNUNET_YES == am_I_alice)
1506 GNUNET_CRYPTO_eddsa_ecdh (my_private_key, /* A */
1507 ephemeral_key, /* B0 */
1512 GNUNET_CRYPTO_ecdh_eddsa (&ax->kx_0, /* B0 */
1513 &pid->public_key, /* A */
1518 if (GNUNET_YES == am_I_alice)
1520 GNUNET_CRYPTO_ecdh_eddsa (&ax->kx_0, /* A0 */
1521 &pid->public_key, /* B */
1526 GNUNET_CRYPTO_eddsa_ecdh (my_private_key, /* A */
1527 ephemeral_key, /* B0 */
1534 /* (This is the triple-DH, we could probably safely skip this,
1535 as A0/B0 are already in the key material.) */
1536 GNUNET_CRYPTO_ecc_ecdh (&ax->kx_0, /* A0 or B0 */
1537 ephemeral_key, /* B0 or A0 */
1541 GNUNET_CRYPTO_kdf (keys, sizeof (keys),
1542 salt, sizeof (salt),
1543 &key_material, sizeof (key_material),
1546 if (0 == memcmp (&ax->RK,
1550 LOG (GNUNET_ERROR_TYPE_DEBUG,
1551 "Root key of handshake already known. Ignoring KX.\n");
1556 if (GNUNET_YES == am_I_alice)
1562 ax->ratchet_flag = GNUNET_YES;
1570 ax->ratchet_flag = GNUNET_NO;
1571 ax->ratchet_expiration
1572 = GNUNET_TIME_absolute_add (GNUNET_TIME_absolute_get(),
1580 * Try to redo the KX or KX_AUTH handshake, if we can.
1582 * @param cls the `struct CadetTunnel` to do KX for.
1585 retry_kx (void *cls)
1587 struct CadetTunnel *t = cls;
1588 struct CadetTunnelAxolotl *ax;
1591 LOG (GNUNET_ERROR_TYPE_DEBUG,
1592 "Trying to make KX progress on %s in state %s\n",
1594 estate2s (t->estate));
1597 case CADET_TUNNEL_KEY_UNINITIALIZED: /* first attempt */
1598 case CADET_TUNNEL_KEY_AX_SENT: /* trying again */
1603 case CADET_TUNNEL_KEY_AX_RECV:
1604 case CADET_TUNNEL_KEY_AX_SENT_AND_RECV:
1605 /* We are responding, so only require reply
1606 if WE have a channel waiting. */
1607 if (NULL != t->unverified_ax)
1609 /* Send AX_AUTH so we might get this one verified */
1610 ax = t->unverified_ax;
1614 /* How can this be? */
1621 (0 == GCT_count_channels (t))
1625 case CADET_TUNNEL_KEY_AX_AUTH_SENT:
1626 /* We are responding, so only require reply
1627 if WE have a channel waiting. */
1628 if (NULL != t->unverified_ax)
1630 /* Send AX_AUTH so we might get this one verified */
1631 ax = t->unverified_ax;
1635 /* How can this be? */
1642 (0 == GCT_count_channels (t))
1646 case CADET_TUNNEL_KEY_OK:
1647 /* Must have been the *other* peer asking us to
1648 respond with a KX_AUTH. */
1649 if (NULL != t->unverified_ax)
1651 /* Sending AX_AUTH in response to AX so we might get this one verified */
1652 ax = t->unverified_ax;
1656 /* Sending AX_AUTH in response to AX_AUTH */
1669 * Handle KX message that lacks authentication (and which will thus
1670 * only be considered authenticated after we respond with our own
1671 * KX_AUTH and finally successfully decrypt payload).
1673 * @param ct connection/tunnel combo that received encrypted message
1674 * @param msg the key exchange message
1677 GCT_handle_kx (struct CadetTConnection *ct,
1678 const struct GNUNET_CADET_TunnelKeyExchangeMessage *msg)
1680 struct CadetTunnel *t = ct->t;
1681 struct CadetTunnelAxolotl *ax;
1685 memcmp (&t->ax.DHRr,
1687 sizeof (msg->ratchet_key)))
1689 LOG (GNUNET_ERROR_TYPE_DEBUG,
1690 "Got duplicate KX. Firing back KX_AUTH.\n");
1698 /* We only keep ONE unverified KX around, so if there is an existing one,
1700 if (NULL != t->unverified_ax)
1703 memcmp (&t->unverified_ax->DHRr,
1705 sizeof (msg->ratchet_key)))
1707 LOG (GNUNET_ERROR_TYPE_DEBUG,
1708 "Got duplicate unverified KX on %s. Fire back KX_AUTH again.\n",
1716 LOG (GNUNET_ERROR_TYPE_DEBUG,
1717 "Dropping old unverified KX state. Got a fresh KX for %s.\n",
1719 memset (t->unverified_ax,
1721 sizeof (struct CadetTunnelAxolotl));
1722 t->unverified_ax->DHRs = t->ax.DHRs;
1723 t->unverified_ax->kx_0 = t->ax.kx_0;
1727 LOG (GNUNET_ERROR_TYPE_DEBUG,
1728 "Creating fresh unverified KX for %s.\n",
1730 t->unverified_ax = GNUNET_new (struct CadetTunnelAxolotl);
1731 t->unverified_ax->DHRs = t->ax.DHRs;
1732 t->unverified_ax->kx_0 = t->ax.kx_0;
1734 /* Set as the 'current' RK/DHRr the one we are currently using,
1735 so that the duplicate-detection logic of
1736 #update_ax_by_kx can work. */
1737 t->unverified_ax->RK = t->ax.RK;
1738 t->unverified_ax->DHRr = t->ax.DHRr;
1739 t->unverified_attempts = 0;
1740 ax = t->unverified_ax;
1742 /* Update 'ax' by the new key material */
1743 ret = update_ax_by_kx (ax,
1744 GCP_get_id (t->destination),
1745 &msg->ephemeral_key,
1747 GNUNET_break (GNUNET_SYSERR != ret);
1748 if (GNUNET_OK != ret)
1749 return; /* duplicate KX, nothing to do */
1751 /* move ahead in our state machine */
1752 if (CADET_TUNNEL_KEY_UNINITIALIZED == t->estate)
1753 GCT_change_estate (t,
1754 CADET_TUNNEL_KEY_AX_RECV);
1755 else if (CADET_TUNNEL_KEY_AX_SENT == t->estate)
1756 GCT_change_estate (t,
1757 CADET_TUNNEL_KEY_AX_SENT_AND_RECV);
1759 /* KX is still not done, try again our end. */
1760 if (CADET_TUNNEL_KEY_OK != t->estate)
1762 if (NULL != t->kx_task)
1763 GNUNET_SCHEDULER_cancel (t->kx_task);
1765 = GNUNET_SCHEDULER_add_now (&retry_kx,
1772 * Handle KX_AUTH message.
1774 * @param ct connection/tunnel combo that received encrypted message
1775 * @param msg the key exchange message
1778 GCT_handle_kx_auth (struct CadetTConnection *ct,
1779 const struct GNUNET_CADET_TunnelKeyExchangeAuthMessage *msg)
1781 struct CadetTunnel *t = ct->t;
1782 struct CadetTunnelAxolotl ax_tmp;
1783 struct GNUNET_HashCode kx_auth;
1786 if ( (CADET_TUNNEL_KEY_UNINITIALIZED == t->estate) ||
1787 (CADET_TUNNEL_KEY_AX_RECV == t->estate) )
1789 /* Confusing, we got a KX_AUTH before we even send our own
1790 KX. This should not happen. We'll send our own KX ASAP anyway,
1791 so let's ignore this here. */
1792 GNUNET_break_op (0);
1795 LOG (GNUNET_ERROR_TYPE_DEBUG,
1796 "Handling KX_AUTH message for %s\n",
1799 /* We do everything in ax_tmp until we've checked the authentication
1800 so we don't clobber anything we care about by accident. */
1803 /* Update 'ax' by the new key material */
1804 ret = update_ax_by_kx (&ax_tmp,
1805 GCP_get_id (t->destination),
1806 &msg->kx.ephemeral_key,
1807 &msg->kx.ratchet_key);
1808 if (GNUNET_OK != ret)
1810 if (GNUNET_NO == ret)
1811 GNUNET_STATISTICS_update (stats,
1812 "# redundant KX_AUTH received",
1816 GNUNET_break (0); /* connect to self!? */
1819 GNUNET_CRYPTO_hash (&ax_tmp.RK,
1822 if (0 != memcmp (&kx_auth,
1826 /* This KX_AUTH is not using the latest KX/KX_AUTH data
1827 we transmitted to the sender, refuse it, try KX again. */
1828 GNUNET_STATISTICS_update (stats,
1829 "# KX_AUTH not using our last KX received (auth failure)",
1837 /* Yep, we're good. */
1839 if (NULL != t->unverified_ax)
1841 /* We got some "stale" KX before, drop that. */
1842 cleanup_ax (t->unverified_ax);
1843 GNUNET_free (t->unverified_ax);
1844 t->unverified_ax = NULL;
1847 /* move ahead in our state machine */
1850 case CADET_TUNNEL_KEY_UNINITIALIZED:
1851 case CADET_TUNNEL_KEY_AX_RECV:
1852 /* Checked above, this is impossible. */
1855 case CADET_TUNNEL_KEY_AX_SENT: /* This is the normal case */
1856 case CADET_TUNNEL_KEY_AX_SENT_AND_RECV: /* both peers started KX */
1857 case CADET_TUNNEL_KEY_AX_AUTH_SENT: /* both peers now did KX_AUTH */
1858 GCT_change_estate (t,
1859 CADET_TUNNEL_KEY_OK);
1861 case CADET_TUNNEL_KEY_OK:
1862 /* Did not expect another KX_AUTH, but so what, still acceptable.
1863 Nothing to do here. */
1870 /* ************************************** end core crypto ***************************** */
1874 * Compute the next free channel tunnel number for this tunnel.
1876 * @param t the tunnel
1877 * @return unused number that can uniquely identify a channel in the tunnel
1879 static struct GNUNET_CADET_ChannelTunnelNumber
1880 get_next_free_ctn (struct CadetTunnel *t)
1882 #define HIGH_BIT 0x8000000
1883 struct GNUNET_CADET_ChannelTunnelNumber ret;
1888 cmp = GNUNET_CRYPTO_cmp_peer_identity (&my_full_id,
1889 GCP_get_id (GCT_get_destination (t)));
1895 GNUNET_assert (0); // loopback must never go here!
1896 ctn = ntohl (t->next_ctn.cn);
1898 GNUNET_CONTAINER_multihashmap32_get (t->channels,
1901 ctn = ((ctn + 1) & (~ HIGH_BIT));
1903 t->next_ctn.cn = htonl ((ctn + 1) & (~ HIGH_BIT));
1904 ret.cn = htonl (ctn | highbit);
1910 * Add a channel to a tunnel, and notify channel that we are ready
1911 * for transmission if we are already up. Otherwise that notification
1912 * will be done later in #notify_tunnel_up_cb().
1916 * @return unique number identifying @a ch within @a t
1918 struct GNUNET_CADET_ChannelTunnelNumber
1919 GCT_add_channel (struct CadetTunnel *t,
1920 struct CadetChannel *ch)
1922 struct GNUNET_CADET_ChannelTunnelNumber ctn;
1924 ctn = get_next_free_ctn (t);
1925 if (NULL != t->destroy_task)
1927 GNUNET_SCHEDULER_cancel (t->destroy_task);
1928 t->destroy_task = NULL;
1930 GNUNET_assert (GNUNET_YES ==
1931 GNUNET_CONTAINER_multihashmap32_put (t->channels,
1934 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY));
1935 LOG (GNUNET_ERROR_TYPE_DEBUG,
1936 "Adding %s to %s\n",
1941 case CADET_TUNNEL_KEY_UNINITIALIZED:
1942 /* waiting for connection to start KX */
1944 case CADET_TUNNEL_KEY_AX_RECV:
1945 case CADET_TUNNEL_KEY_AX_SENT:
1946 case CADET_TUNNEL_KEY_AX_SENT_AND_RECV:
1947 /* we're currently waiting for KX to complete */
1949 case CADET_TUNNEL_KEY_AX_AUTH_SENT:
1950 /* waiting for OTHER peer to send us data,
1951 we might need to prompt more aggressively! */
1952 if (NULL == t->kx_task)
1954 = GNUNET_SCHEDULER_add_at (t->next_kx_attempt,
1958 case CADET_TUNNEL_KEY_OK:
1959 /* We are ready. Tell the new channel that we are up. */
1960 GCCH_tunnel_up (ch);
1968 * We lost a connection, remove it from our list and clean up
1969 * the connection object itself.
1971 * @param ct binding of connection to tunnel of the connection that was lost.
1974 GCT_connection_lost (struct CadetTConnection *ct)
1976 struct CadetTunnel *t = ct->t;
1978 if (GNUNET_YES == ct->is_ready)
1980 GNUNET_CONTAINER_DLL_remove (t->connection_ready_head,
1981 t->connection_ready_tail,
1983 t->num_ready_connections--;
1987 GNUNET_CONTAINER_DLL_remove (t->connection_busy_head,
1988 t->connection_busy_tail,
1990 t->num_busy_connections--;
1997 * Clean up connection @a ct of a tunnel.
1999 * @param cls the `struct CadetTunnel`
2000 * @param ct connection to clean up
2003 destroy_t_connection (void *cls,
2004 struct CadetTConnection *ct)
2006 struct CadetTunnel *t = cls;
2007 struct CadetConnection *cc = ct->cc;
2009 GNUNET_assert (ct->t == t);
2010 GCT_connection_lost (ct);
2011 GCC_destroy_without_tunnel (cc);
2016 * This tunnel is no longer used, destroy it.
2018 * @param cls the idle tunnel
2021 destroy_tunnel (void *cls)
2023 struct CadetTunnel *t = cls;
2024 struct CadetTunnelQueueEntry *tq;
2026 t->destroy_task = NULL;
2027 LOG (GNUNET_ERROR_TYPE_DEBUG,
2028 "Destroying idle %s\n",
2030 GNUNET_assert (0 == GCT_count_channels (t));
2031 GCT_iterate_connections (t,
2032 &destroy_t_connection,
2034 GNUNET_assert (NULL == t->connection_ready_head);
2035 GNUNET_assert (NULL == t->connection_busy_head);
2036 while (NULL != (tq = t->tq_head))
2038 if (NULL != tq->cont)
2039 tq->cont (tq->cont_cls,
2041 GCT_send_cancel (tq);
2043 GCP_drop_tunnel (t->destination,
2045 GNUNET_CONTAINER_multihashmap32_destroy (t->channels);
2046 if (NULL != t->maintain_connections_task)
2048 GNUNET_SCHEDULER_cancel (t->maintain_connections_task);
2049 t->maintain_connections_task = NULL;
2051 if (NULL != t->send_task)
2053 GNUNET_SCHEDULER_cancel (t->send_task);
2054 t->send_task = NULL;
2056 if (NULL != t->kx_task)
2058 GNUNET_SCHEDULER_cancel (t->kx_task);
2061 GNUNET_MST_destroy (t->mst);
2062 GNUNET_MQ_destroy (t->mq);
2063 if (NULL != t->unverified_ax)
2065 cleanup_ax (t->unverified_ax);
2066 GNUNET_free (t->unverified_ax);
2068 cleanup_ax (&t->ax);
2069 GNUNET_assert (NULL == t->destroy_task);
2075 * Remove a channel from a tunnel.
2079 * @param ctn unique number identifying @a ch within @a t
2082 GCT_remove_channel (struct CadetTunnel *t,
2083 struct CadetChannel *ch,
2084 struct GNUNET_CADET_ChannelTunnelNumber ctn)
2086 LOG (GNUNET_ERROR_TYPE_DEBUG,
2087 "Removing %s from %s\n",
2090 GNUNET_assert (GNUNET_YES ==
2091 GNUNET_CONTAINER_multihashmap32_remove (t->channels,
2095 GCT_count_channels (t)) &&
2096 (NULL == t->destroy_task) )
2099 = GNUNET_SCHEDULER_add_delayed (IDLE_DESTROY_DELAY,
2107 * Destroy remaining channels during shutdown.
2109 * @param cls the `struct CadetTunnel` of the channel
2110 * @param key key of the channel
2111 * @param value the `struct CadetChannel`
2112 * @return #GNUNET_OK (continue to iterate)
2115 destroy_remaining_channels (void *cls,
2119 struct CadetChannel *ch = value;
2121 GCCH_handle_remote_destroy (ch,
2128 * Destroys the tunnel @a t now, without delay. Used during shutdown.
2130 * @param t tunnel to destroy
2133 GCT_destroy_tunnel_now (struct CadetTunnel *t)
2135 GNUNET_assert (GNUNET_YES == shutting_down);
2136 GNUNET_CONTAINER_multihashmap32_iterate (t->channels,
2137 &destroy_remaining_channels,
2140 GCT_count_channels (t));
2141 if (NULL != t->destroy_task)
2143 GNUNET_SCHEDULER_cancel (t->destroy_task);
2144 t->destroy_task = NULL;
2151 * Send normal payload from queue in @a t via connection @a ct.
2152 * Does nothing if our payload queue is empty.
2154 * @param t tunnel to send data from
2155 * @param ct connection to use for transmission (is ready)
2158 try_send_normal_payload (struct CadetTunnel *t,
2159 struct CadetTConnection *ct)
2161 struct CadetTunnelQueueEntry *tq;
2163 GNUNET_assert (GNUNET_YES == ct->is_ready);
2167 /* no messages pending right now */
2168 LOG (GNUNET_ERROR_TYPE_DEBUG,
2169 "Not sending payload of %s on ready %s (nothing pending)\n",
2174 /* ready to send message 'tq' on tunnel 'ct' */
2175 GNUNET_assert (t == tq->t);
2176 GNUNET_CONTAINER_DLL_remove (t->tq_head,
2179 if (NULL != tq->cid)
2180 *tq->cid = *GCC_get_id (ct->cc);
2181 mark_connection_unready (ct);
2182 LOG (GNUNET_ERROR_TYPE_DEBUG,
2183 "Sending payload of %s on %s\n",
2186 GCC_transmit (ct->cc,
2188 if (NULL != tq->cont)
2189 tq->cont (tq->cont_cls,
2190 GCC_get_id (ct->cc));
2196 * A connection is @a is_ready for transmission. Looks at our message
2197 * queue and if there is a message, sends it out via the connection.
2199 * @param cls the `struct CadetTConnection` that is @a is_ready
2200 * @param is_ready #GNUNET_YES if connection are now ready,
2201 * #GNUNET_NO if connection are no longer ready
2204 connection_ready_cb (void *cls,
2207 struct CadetTConnection *ct = cls;
2208 struct CadetTunnel *t = ct->t;
2210 if (GNUNET_NO == is_ready)
2212 LOG (GNUNET_ERROR_TYPE_DEBUG,
2213 "%s no longer ready for %s\n",
2216 mark_connection_unready (ct);
2219 GNUNET_assert (GNUNET_NO == ct->is_ready);
2220 GNUNET_CONTAINER_DLL_remove (t->connection_busy_head,
2221 t->connection_busy_tail,
2223 GNUNET_assert (0 < t->num_busy_connections);
2224 t->num_busy_connections--;
2225 ct->is_ready = GNUNET_YES;
2226 GNUNET_CONTAINER_DLL_insert_tail (t->connection_ready_head,
2227 t->connection_ready_tail,
2229 t->num_ready_connections++;
2231 LOG (GNUNET_ERROR_TYPE_DEBUG,
2232 "%s now ready for %s in state %s\n",
2235 estate2s (t->estate));
2238 case CADET_TUNNEL_KEY_UNINITIALIZED:
2239 /* Do not begin KX if WE have no channels waiting! */
2240 if (0 == GCT_count_channels (t))
2242 /* We are uninitialized, just transmit immediately,
2243 without undue delay. */
2244 if (NULL != t->kx_task)
2246 GNUNET_SCHEDULER_cancel (t->kx_task);
2253 case CADET_TUNNEL_KEY_AX_RECV:
2254 case CADET_TUNNEL_KEY_AX_SENT:
2255 case CADET_TUNNEL_KEY_AX_SENT_AND_RECV:
2256 case CADET_TUNNEL_KEY_AX_AUTH_SENT:
2257 /* we're currently waiting for KX to complete, schedule job */
2258 if (NULL == t->kx_task)
2260 = GNUNET_SCHEDULER_add_at (t->next_kx_attempt,
2264 case CADET_TUNNEL_KEY_OK:
2265 if (GNUNET_YES == t->kx_auth_requested)
2267 if (NULL != t->kx_task)
2269 GNUNET_SCHEDULER_cancel (t->kx_task);
2278 try_send_normal_payload (t,
2286 * Called when either we have a new connection, or a new message in the
2287 * queue, or some existing connection has transmission capacity. Looks
2288 * at our message queue and if there is a message, picks a connection
2291 * @param cls the `struct CadetTunnel` to process messages on
2294 trigger_transmissions (void *cls)
2296 struct CadetTunnel *t = cls;
2297 struct CadetTConnection *ct;
2299 t->send_task = NULL;
2300 if (NULL == t->tq_head)
2301 return; /* no messages pending right now */
2302 ct = get_ready_connection (t);
2304 return; /* no connections ready */
2305 try_send_normal_payload (t,
2311 * Closure for #evaluate_connection. Used to assemble summary information
2312 * about the existing connections so we can evaluate a new path.
2314 struct EvaluationSummary
2318 * Minimum length of any of our connections, `UINT_MAX` if we have none.
2320 unsigned int min_length;
2323 * Maximum length of any of our connections, 0 if we have none.
2325 unsigned int max_length;
2328 * Minimum desirability of any of our connections, UINT64_MAX if we have none.
2330 GNUNET_CONTAINER_HeapCostType min_desire;
2333 * Maximum desirability of any of our connections, 0 if we have none.
2335 GNUNET_CONTAINER_HeapCostType max_desire;
2338 * Path we are comparing against for #evaluate_connection, can be NULL.
2340 struct CadetPeerPath *path;
2343 * Connection deemed the "worst" so far encountered by #evaluate_connection,
2344 * NULL if we did not yet encounter any connections.
2346 struct CadetTConnection *worst;
2349 * Numeric score of @e worst, only set if @e worst is non-NULL.
2354 * Set to #GNUNET_YES if we have a connection over @e path already.
2362 * Evaluate a connection, updating our summary information in @a cls about
2363 * what kinds of connections we have.
2365 * @param cls the `struct EvaluationSummary *` to update
2366 * @param ct a connection to include in the summary
2369 evaluate_connection (void *cls,
2370 struct CadetTConnection *ct)
2372 struct EvaluationSummary *es = cls;
2373 struct CadetConnection *cc = ct->cc;
2374 struct CadetPeerPath *ps = GCC_get_path (cc);
2375 const struct CadetConnectionMetrics *metrics;
2376 GNUNET_CONTAINER_HeapCostType ct_desirability;
2377 struct GNUNET_TIME_Relative uptime;
2378 struct GNUNET_TIME_Relative last_use;
2381 double success_rate;
2385 LOG (GNUNET_ERROR_TYPE_DEBUG,
2386 "Ignoring duplicate path %s.\n",
2387 GCPP_2s (es->path));
2388 es->duplicate = GNUNET_YES;
2391 ct_desirability = GCPP_get_desirability (ps);
2392 ct_length = GCPP_get_length (ps);
2393 metrics = GCC_get_metrics (cc);
2394 uptime = GNUNET_TIME_absolute_get_duration (metrics->age);
2395 last_use = GNUNET_TIME_absolute_get_duration (metrics->last_use);
2396 /* We add 1.0 here to avoid division by zero. */
2397 success_rate = (metrics->num_acked_transmissions + 1.0) / (metrics->num_successes + 1.0);
2400 + 100.0 / (1.0 + ct_length) /* longer paths = better */
2401 + sqrt (uptime.rel_value_us / 60000000LL) /* larger uptime = better */
2402 - last_use.rel_value_us / 1000L; /* longer idle = worse */
2403 score *= success_rate; /* weigh overall by success rate */
2405 if ( (NULL == es->worst) ||
2406 (score < es->worst_score) )
2409 es->worst_score = score;
2411 es->min_length = GNUNET_MIN (es->min_length,
2413 es->max_length = GNUNET_MAX (es->max_length,
2415 es->min_desire = GNUNET_MIN (es->min_desire,
2417 es->max_desire = GNUNET_MAX (es->max_desire,
2423 * Consider using the path @a p for the tunnel @a t.
2424 * The tunnel destination is at offset @a off in path @a p.
2426 * @param cls our tunnel
2427 * @param path a path to our destination
2428 * @param off offset of the destination on path @a path
2429 * @return #GNUNET_YES (should keep iterating)
2432 consider_path_cb (void *cls,
2433 struct CadetPeerPath *path,
2436 struct CadetTunnel *t = cls;
2437 struct EvaluationSummary es;
2438 struct CadetTConnection *ct;
2440 GNUNET_assert (off < GCPP_get_length (path));
2441 es.min_length = UINT_MAX;
2444 es.min_desire = UINT64_MAX;
2446 es.duplicate = GNUNET_NO;
2449 /* Compute evaluation summary over existing connections. */
2450 GCT_iterate_connections (t,
2451 &evaluate_connection,
2453 if (GNUNET_YES == es.duplicate)
2456 /* FIXME: not sure we should really just count
2457 'num_connections' here, as they may all have
2458 consistently failed to connect. */
2460 /* We iterate by increasing path length; if we have enough paths and
2461 this one is more than twice as long than what we are currently
2462 using, then ignore all of these super-long ones! */
2463 if ( (GCT_count_any_connections (t) > DESIRED_CONNECTIONS_PER_TUNNEL) &&
2464 (es.min_length * 2 < off) &&
2465 (es.max_length < off) )
2467 LOG (GNUNET_ERROR_TYPE_DEBUG,
2468 "Ignoring paths of length %u, they are way too long.\n",
2472 /* If we have enough paths and this one looks no better, ignore it. */
2473 if ( (GCT_count_any_connections (t) >= DESIRED_CONNECTIONS_PER_TUNNEL) &&
2474 (es.min_length < GCPP_get_length (path)) &&
2475 (es.min_desire > GCPP_get_desirability (path)) &&
2476 (es.max_length < off) )
2478 LOG (GNUNET_ERROR_TYPE_DEBUG,
2479 "Ignoring path (%u/%llu) to %s, got something better already.\n",
2480 GCPP_get_length (path),
2481 (unsigned long long) GCPP_get_desirability (path),
2482 GCP_2s (t->destination));
2486 /* Path is interesting (better by some metric, or we don't have
2487 enough paths yet). */
2488 ct = GNUNET_new (struct CadetTConnection);
2489 ct->created = GNUNET_TIME_absolute_get ();
2491 ct->cc = GCC_create (t->destination,
2494 GNUNET_CADET_OPTION_DEFAULT, /* FIXME: set based on what channels want/need! */
2496 &connection_ready_cb,
2499 /* FIXME: schedule job to kill connection (and path?) if it takes
2500 too long to get ready! (And track performance data on how long
2501 other connections took with the tunnel!)
2502 => Note: to be done within 'connection'-logic! */
2503 GNUNET_CONTAINER_DLL_insert (t->connection_busy_head,
2504 t->connection_busy_tail,
2506 t->num_busy_connections++;
2507 LOG (GNUNET_ERROR_TYPE_DEBUG,
2508 "Found interesting path %s for %s, created %s\n",
2517 * Function called to maintain the connections underlying our tunnel.
2518 * Tries to maintain (incl. tear down) connections for the tunnel, and
2519 * if there is a significant change, may trigger transmissions.
2521 * Basically, needs to check if there are connections that perform
2522 * badly, and if so eventually kill them and trigger a replacement.
2523 * The strategy is to open one more connection than
2524 * #DESIRED_CONNECTIONS_PER_TUNNEL, and then periodically kick out the
2525 * least-performing one, and then inquire for new ones.
2527 * @param cls the `struct CadetTunnel`
2530 maintain_connections_cb (void *cls)
2532 struct CadetTunnel *t = cls;
2533 struct GNUNET_TIME_Relative delay;
2534 struct EvaluationSummary es;
2536 t->maintain_connections_task = NULL;
2537 LOG (GNUNET_ERROR_TYPE_DEBUG,
2538 "Performing connection maintenance for %s.\n",
2541 es.min_length = UINT_MAX;
2544 es.min_desire = UINT64_MAX;
2547 es.duplicate = GNUNET_NO;
2548 GCT_iterate_connections (t,
2549 &evaluate_connection,
2551 if ( (NULL != es.worst) &&
2552 (GCT_count_any_connections (t) > DESIRED_CONNECTIONS_PER_TUNNEL) )
2554 /* Clear out worst-performing connection 'es.worst'. */
2555 destroy_t_connection (t,
2559 /* Consider additional paths */
2560 (void) GCP_iterate_paths (t->destination,
2564 /* FIXME: calculate when to try again based on how well we are doing;
2565 in particular, if we have to few connections, we might be able
2566 to do without this (as PATHS should tell us whenever a new path
2567 is available instantly; however, need to make sure this job is
2568 restarted after that happens).
2569 Furthermore, if the paths we do know are in a reasonably narrow
2570 quality band and are plentyful, we might also consider us stabilized
2571 and then reduce the frequency accordingly. */
2572 delay = GNUNET_TIME_UNIT_MINUTES;
2573 t->maintain_connections_task
2574 = GNUNET_SCHEDULER_add_delayed (delay,
2575 &maintain_connections_cb,
2581 * Consider using the path @a p for the tunnel @a t.
2582 * The tunnel destination is at offset @a off in path @a p.
2584 * @param cls our tunnel
2585 * @param path a path to our destination
2586 * @param off offset of the destination on path @a path
2589 GCT_consider_path (struct CadetTunnel *t,
2590 struct CadetPeerPath *p,
2593 LOG (GNUNET_ERROR_TYPE_DEBUG,
2594 "Considering %s for %s\n",
2597 (void) consider_path_cb (t,
2604 * We got a keepalive. Track in statistics.
2606 * @param cls the `struct CadetTunnel` for which we decrypted the message
2607 * @param msg the message we received on the tunnel
2610 handle_plaintext_keepalive (void *cls,
2611 const struct GNUNET_MessageHeader *msg)
2613 struct CadetTunnel *t = cls;
2615 LOG (GNUNET_ERROR_TYPE_DEBUG,
2616 "Received KEEPALIVE on %s\n",
2618 GNUNET_STATISTICS_update (stats,
2619 "# keepalives received",
2626 * Check that @a msg is well-formed.
2628 * @param cls the `struct CadetTunnel` for which we decrypted the message
2629 * @param msg the message we received on the tunnel
2630 * @return #GNUNET_OK (any variable-size payload goes)
2633 check_plaintext_data (void *cls,
2634 const struct GNUNET_CADET_ChannelAppDataMessage *msg)
2641 * We received payload data for a channel. Locate the channel
2642 * and process the data, or return an error if the channel is unknown.
2644 * @param cls the `struct CadetTunnel` for which we decrypted the message
2645 * @param msg the message we received on the tunnel
2648 handle_plaintext_data (void *cls,
2649 const struct GNUNET_CADET_ChannelAppDataMessage *msg)
2651 struct CadetTunnel *t = cls;
2652 struct CadetChannel *ch;
2654 ch = lookup_channel (t,
2658 /* We don't know about such a channel, might have been destroyed on our
2659 end in the meantime, or never existed. Send back a DESTROY. */
2660 LOG (GNUNET_ERROR_TYPE_DEBUG,
2661 "Received %u bytes of application data for unknown channel %u, sending DESTROY\n",
2662 (unsigned int) (ntohs (msg->header.size) - sizeof (*msg)),
2663 ntohl (msg->ctn.cn));
2664 GCT_send_channel_destroy (t,
2668 GCCH_handle_channel_plaintext_data (ch,
2669 GCC_get_id (t->current_ct->cc),
2675 * We received an acknowledgement for data we sent on a channel.
2676 * Locate the channel and process it, or return an error if the
2677 * channel is unknown.
2679 * @param cls the `struct CadetTunnel` for which we decrypted the message
2680 * @param ack the message we received on the tunnel
2683 handle_plaintext_data_ack (void *cls,
2684 const struct GNUNET_CADET_ChannelDataAckMessage *ack)
2686 struct CadetTunnel *t = cls;
2687 struct CadetChannel *ch;
2689 ch = lookup_channel (t,
2693 /* We don't know about such a channel, might have been destroyed on our
2694 end in the meantime, or never existed. Send back a DESTROY. */
2695 LOG (GNUNET_ERROR_TYPE_DEBUG,
2696 "Received DATA_ACK for unknown channel %u, sending DESTROY\n",
2697 ntohl (ack->ctn.cn));
2698 GCT_send_channel_destroy (t,
2702 GCCH_handle_channel_plaintext_data_ack (ch,
2703 GCC_get_id (t->current_ct->cc),
2709 * We have received a request to open a channel to a port from
2710 * another peer. Creates the incoming channel.
2712 * @param cls the `struct CadetTunnel` for which we decrypted the message
2713 * @param copen the message we received on the tunnel
2716 handle_plaintext_channel_open (void *cls,
2717 const struct GNUNET_CADET_ChannelOpenMessage *copen)
2719 struct CadetTunnel *t = cls;
2720 struct CadetChannel *ch;
2722 ch = GNUNET_CONTAINER_multihashmap32_get (t->channels,
2723 ntohl (copen->ctn.cn));
2726 LOG (GNUNET_ERROR_TYPE_DEBUG,
2727 "Received duplicate channel CHANNEL_OPEN on port %s from %s (%s), resending ACK\n",
2728 GNUNET_h2s (&copen->port),
2731 GCCH_handle_duplicate_open (ch,
2732 GCC_get_id (t->current_ct->cc));
2735 LOG (GNUNET_ERROR_TYPE_DEBUG,
2736 "Received CHANNEL_OPEN on port %s from %s\n",
2737 GNUNET_h2s (&copen->port),
2739 ch = GCCH_channel_incoming_new (t,
2742 ntohl (copen->opt));
2743 if (NULL != t->destroy_task)
2745 GNUNET_SCHEDULER_cancel (t->destroy_task);
2746 t->destroy_task = NULL;
2748 GNUNET_assert (GNUNET_OK ==
2749 GNUNET_CONTAINER_multihashmap32_put (t->channels,
2750 ntohl (copen->ctn.cn),
2752 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY));
2757 * Send a DESTROY message via the tunnel.
2759 * @param t the tunnel to transmit over
2760 * @param ctn ID of the channel to destroy
2763 GCT_send_channel_destroy (struct CadetTunnel *t,
2764 struct GNUNET_CADET_ChannelTunnelNumber ctn)
2766 struct GNUNET_CADET_ChannelManageMessage msg;
2768 LOG (GNUNET_ERROR_TYPE_DEBUG,
2769 "Sending DESTORY message for channel ID %u\n",
2771 msg.header.size = htons (sizeof (msg));
2772 msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_CHANNEL_DESTROY);
2773 msg.reserved = htonl (0);
2783 * We have received confirmation from the target peer that the
2784 * given channel could be established (the port is open).
2787 * @param cls the `struct CadetTunnel` for which we decrypted the message
2788 * @param cm the message we received on the tunnel
2791 handle_plaintext_channel_open_ack (void *cls,
2792 const struct GNUNET_CADET_ChannelManageMessage *cm)
2794 struct CadetTunnel *t = cls;
2795 struct CadetChannel *ch;
2797 ch = lookup_channel (t,
2801 /* We don't know about such a channel, might have been destroyed on our
2802 end in the meantime, or never existed. Send back a DESTROY. */
2803 LOG (GNUNET_ERROR_TYPE_DEBUG,
2804 "Received channel OPEN_ACK for unknown channel %u, sending DESTROY\n",
2805 ntohl (cm->ctn.cn));
2806 GCT_send_channel_destroy (t,
2810 LOG (GNUNET_ERROR_TYPE_DEBUG,
2811 "Received channel OPEN_ACK on channel %s from %s\n",
2814 GCCH_handle_channel_open_ack (ch,
2815 GCC_get_id (t->current_ct->cc));
2820 * We received a message saying that a channel should be destroyed.
2821 * Pass it on to the correct channel.
2823 * @param cls the `struct CadetTunnel` for which we decrypted the message
2824 * @param cm the message we received on the tunnel
2827 handle_plaintext_channel_destroy (void *cls,
2828 const struct GNUNET_CADET_ChannelManageMessage *cm)
2830 struct CadetTunnel *t = cls;
2831 struct CadetChannel *ch;
2833 ch = lookup_channel (t,
2837 /* We don't know about such a channel, might have been destroyed on our
2838 end in the meantime, or never existed. */
2839 LOG (GNUNET_ERROR_TYPE_DEBUG,
2840 "Received channel DESTORY for unknown channel %u. Ignoring.\n",
2841 ntohl (cm->ctn.cn));
2844 LOG (GNUNET_ERROR_TYPE_DEBUG,
2845 "Received channel DESTROY on %s from %s\n",
2848 GCCH_handle_remote_destroy (ch,
2849 GCC_get_id (t->current_ct->cc));
2854 * Handles a message we decrypted, by injecting it into
2855 * our message queue (which will do the dispatching).
2857 * @param cls the `struct CadetTunnel` that got the message
2858 * @param msg the message
2859 * @return #GNUNET_OK (continue to process)
2862 handle_decrypted (void *cls,
2863 const struct GNUNET_MessageHeader *msg)
2865 struct CadetTunnel *t = cls;
2867 GNUNET_assert (NULL != t->current_ct);
2868 GNUNET_MQ_inject_message (t->mq,
2875 * Function called if we had an error processing
2876 * an incoming decrypted message.
2878 * @param cls the `struct CadetTunnel`
2879 * @param error error code
2882 decrypted_error_cb (void *cls,
2883 enum GNUNET_MQ_Error error)
2885 GNUNET_break_op (0);
2890 * Create a tunnel to @a destionation. Must only be called
2891 * from within #GCP_get_tunnel().
2893 * @param destination where to create the tunnel to
2894 * @return new tunnel to @a destination
2896 struct CadetTunnel *
2897 GCT_create_tunnel (struct CadetPeer *destination)
2899 struct CadetTunnel *t = GNUNET_new (struct CadetTunnel);
2900 struct GNUNET_MQ_MessageHandler handlers[] = {
2901 GNUNET_MQ_hd_fixed_size (plaintext_keepalive,
2902 GNUNET_MESSAGE_TYPE_CADET_CHANNEL_KEEPALIVE,
2903 struct GNUNET_MessageHeader,
2905 GNUNET_MQ_hd_var_size (plaintext_data,
2906 GNUNET_MESSAGE_TYPE_CADET_CHANNEL_APP_DATA,
2907 struct GNUNET_CADET_ChannelAppDataMessage,
2909 GNUNET_MQ_hd_fixed_size (plaintext_data_ack,
2910 GNUNET_MESSAGE_TYPE_CADET_CHANNEL_APP_DATA_ACK,
2911 struct GNUNET_CADET_ChannelDataAckMessage,
2913 GNUNET_MQ_hd_fixed_size (plaintext_channel_open,
2914 GNUNET_MESSAGE_TYPE_CADET_CHANNEL_OPEN,
2915 struct GNUNET_CADET_ChannelOpenMessage,
2917 GNUNET_MQ_hd_fixed_size (plaintext_channel_open_ack,
2918 GNUNET_MESSAGE_TYPE_CADET_CHANNEL_OPEN_ACK,
2919 struct GNUNET_CADET_ChannelManageMessage,
2921 GNUNET_MQ_hd_fixed_size (plaintext_channel_destroy,
2922 GNUNET_MESSAGE_TYPE_CADET_CHANNEL_DESTROY,
2923 struct GNUNET_CADET_ChannelManageMessage,
2925 GNUNET_MQ_handler_end ()
2928 t->kx_retry_delay = INITIAL_KX_RETRY_DELAY;
2929 new_ephemeral (&t->ax);
2930 GNUNET_assert (GNUNET_OK ==
2931 GNUNET_CRYPTO_ecdhe_key_create2 (&t->ax.kx_0));
2932 t->destination = destination;
2933 t->channels = GNUNET_CONTAINER_multihashmap32_create (8);
2934 t->maintain_connections_task
2935 = GNUNET_SCHEDULER_add_now (&maintain_connections_cb,
2937 t->mq = GNUNET_MQ_queue_for_callbacks (NULL,
2942 &decrypted_error_cb,
2944 t->mst = GNUNET_MST_create (&handle_decrypted,
2951 * Add a @a connection to the @a tunnel.
2954 * @param cid connection identifer to use for the connection
2955 * @param options options for the connection
2956 * @param path path to use for the connection
2957 * @return #GNUNET_OK on success,
2958 * #GNUNET_SYSERR on failure (duplicate connection)
2961 GCT_add_inbound_connection (struct CadetTunnel *t,
2962 const struct GNUNET_CADET_ConnectionTunnelIdentifier *cid,
2963 enum GNUNET_CADET_ChannelOption options,
2964 struct CadetPeerPath *path)
2966 struct CadetTConnection *ct;
2968 ct = GNUNET_new (struct CadetTConnection);
2969 ct->created = GNUNET_TIME_absolute_get ();
2971 ct->cc = GCC_create_inbound (t->destination,
2976 &connection_ready_cb,
2980 LOG (GNUNET_ERROR_TYPE_DEBUG,
2981 "%s refused inbound %s (duplicate)\n",
2985 return GNUNET_SYSERR;
2987 /* FIXME: schedule job to kill connection (and path?) if it takes
2988 too long to get ready! (And track performance data on how long
2989 other connections took with the tunnel!)
2990 => Note: to be done within 'connection'-logic! */
2991 GNUNET_CONTAINER_DLL_insert (t->connection_busy_head,
2992 t->connection_busy_tail,
2994 t->num_busy_connections++;
2995 LOG (GNUNET_ERROR_TYPE_DEBUG,
3004 * Handle encrypted message.
3006 * @param ct connection/tunnel combo that received encrypted message
3007 * @param msg the encrypted message to decrypt
3010 GCT_handle_encrypted (struct CadetTConnection *ct,
3011 const struct GNUNET_CADET_TunnelEncryptedMessage *msg)
3013 struct CadetTunnel *t = ct->t;
3014 uint16_t size = ntohs (msg->header.size);
3015 char cbuf [size] GNUNET_ALIGN;
3016 ssize_t decrypted_size;
3018 LOG (GNUNET_ERROR_TYPE_DEBUG,
3019 "%s received %u bytes of encrypted data in state %d\n",
3021 (unsigned int) size,
3026 case CADET_TUNNEL_KEY_UNINITIALIZED:
3027 case CADET_TUNNEL_KEY_AX_RECV:
3028 /* We did not even SEND our KX, how can the other peer
3029 send us encrypted data? Must have been that we went
3030 down and the other peer still things we are up.
3031 Let's send it KX back. */
3032 GNUNET_STATISTICS_update (stats,
3033 "# received encrypted without any KX",
3036 if (NULL != t->kx_task)
3038 GNUNET_SCHEDULER_cancel (t->kx_task);
3045 case CADET_TUNNEL_KEY_AX_SENT_AND_RECV:
3046 /* We send KX, and other peer send KX to us at the same time.
3047 Neither KX is AUTH'ed, so let's try KX_AUTH this time. */
3048 GNUNET_STATISTICS_update (stats,
3049 "# received encrypted without KX_AUTH",
3052 if (NULL != t->kx_task)
3054 GNUNET_SCHEDULER_cancel (t->kx_task);
3062 case CADET_TUNNEL_KEY_AX_SENT:
3063 /* We did not get the KX of the other peer, but that
3064 might have been lost. Send our KX again immediately. */
3065 GNUNET_STATISTICS_update (stats,
3066 "# received encrypted without KX",
3069 if (NULL != t->kx_task)
3071 GNUNET_SCHEDULER_cancel (t->kx_task);
3078 case CADET_TUNNEL_KEY_AX_AUTH_SENT:
3079 /* Great, first payload, we might graduate to OK! */
3080 case CADET_TUNNEL_KEY_OK:
3081 /* We are up and running, all good. */
3085 decrypted_size = -1;
3086 if (CADET_TUNNEL_KEY_OK == t->estate)
3088 /* We have well-established key material available,
3089 try that. (This is the common case.) */
3090 decrypted_size = t_ax_decrypt_and_validate (&t->ax,
3096 if ( (-1 == decrypted_size) &&
3097 (NULL != t->unverified_ax) )
3099 /* We have un-authenticated KX material available. We should try
3100 this as a back-up option, in case the sender crashed and
3102 decrypted_size = t_ax_decrypt_and_validate (t->unverified_ax,
3106 if (-1 != decrypted_size)
3108 /* It worked! Treat this as authentication of the AX data! */
3109 cleanup_ax (&t->ax);
3110 t->ax = *t->unverified_ax;
3111 GNUNET_free (t->unverified_ax);
3112 t->unverified_ax = NULL;
3114 if (CADET_TUNNEL_KEY_AX_AUTH_SENT == t->estate)
3116 /* First time it worked, move tunnel into production! */
3117 GCT_change_estate (t,
3118 CADET_TUNNEL_KEY_OK);
3119 if (NULL != t->send_task)
3120 GNUNET_SCHEDULER_cancel (t->send_task);
3121 t->send_task = GNUNET_SCHEDULER_add_now (&trigger_transmissions,
3125 if (NULL != t->unverified_ax)
3127 /* We had unverified KX material that was useless; so increment
3128 counter and eventually move to ignore it. Note that we even do
3129 this increment if we successfully decrypted with the old KX
3130 material and thus didn't even both with the new one. This is
3131 the ideal case, as a malicious injection of bogus KX data
3132 basically only causes us to increment a counter a few times. */
3133 t->unverified_attempts++;
3134 LOG (GNUNET_ERROR_TYPE_DEBUG,
3135 "Failed to decrypt message with unverified KX data %u times\n",
3136 t->unverified_attempts);
3137 if (t->unverified_attempts > MAX_UNVERIFIED_ATTEMPTS)
3139 cleanup_ax (t->unverified_ax);
3140 GNUNET_free (t->unverified_ax);
3141 t->unverified_ax = NULL;
3145 if (-1 == decrypted_size)
3147 /* Decryption failed for good, complain. */
3148 LOG (GNUNET_ERROR_TYPE_WARNING,
3149 "%s failed to decrypt and validate encrypted data, retrying KX\n",
3151 GNUNET_STATISTICS_update (stats,
3152 "# unable to decrypt",
3155 if (NULL != t->kx_task)
3157 GNUNET_SCHEDULER_cancel (t->kx_task);
3165 GNUNET_STATISTICS_update (stats,
3166 "# decrypted bytes",
3170 /* The MST will ultimately call #handle_decrypted() on each message. */
3172 GNUNET_break_op (GNUNET_OK ==
3173 GNUNET_MST_from_buffer (t->mst,
3178 t->current_ct = NULL;
3183 * Sends an already built message on a tunnel, encrypting it and
3184 * choosing the best connection if not provided.
3186 * @param message Message to send. Function modifies it.
3187 * @param t Tunnel on which this message is transmitted.
3188 * @param cont Continuation to call once message is really sent.
3189 * @param cont_cls Closure for @c cont.
3190 * @return Handle to cancel message
3192 struct CadetTunnelQueueEntry *
3193 GCT_send (struct CadetTunnel *t,
3194 const struct GNUNET_MessageHeader *message,
3195 GCT_SendContinuation cont,
3198 struct CadetTunnelQueueEntry *tq;
3199 uint16_t payload_size;
3200 struct GNUNET_MQ_Envelope *env;
3201 struct GNUNET_CADET_TunnelEncryptedMessage *ax_msg;
3203 if (CADET_TUNNEL_KEY_OK != t->estate)
3208 payload_size = ntohs (message->size);
3209 LOG (GNUNET_ERROR_TYPE_DEBUG,
3210 "Encrypting %u bytes for %s\n",
3211 (unsigned int) payload_size,
3213 env = GNUNET_MQ_msg_extra (ax_msg,
3215 GNUNET_MESSAGE_TYPE_CADET_TUNNEL_ENCRYPTED);
3216 t_ax_encrypt (&t->ax,
3220 GNUNET_STATISTICS_update (stats,
3221 "# encrypted bytes",
3224 ax_msg->ax_header.Ns = htonl (t->ax.Ns++);
3225 ax_msg->ax_header.PNs = htonl (t->ax.PNs);
3226 /* FIXME: we should do this once, not once per message;
3227 this is a point multiplication, and DHRs does not
3228 change all the time. */
3229 GNUNET_CRYPTO_ecdhe_key_get_public (&t->ax.DHRs,
3230 &ax_msg->ax_header.DHRs);
3231 t_h_encrypt (&t->ax,
3233 t_hmac (&ax_msg->ax_header,
3234 sizeof (struct GNUNET_CADET_AxHeader) + payload_size,
3239 tq = GNUNET_malloc (sizeof (*tq));
3242 tq->cid = &ax_msg->cid; /* will initialize 'ax_msg->cid' once we know the connection */
3244 tq->cont_cls = cont_cls;
3245 GNUNET_CONTAINER_DLL_insert_tail (t->tq_head,
3248 if (NULL != t->send_task)
3249 GNUNET_SCHEDULER_cancel (t->send_task);
3251 = GNUNET_SCHEDULER_add_now (&trigger_transmissions,
3258 * Cancel a previously sent message while it's in the queue.
3260 * ONLY can be called before the continuation given to the send
3261 * function is called. Once the continuation is called, the message is
3262 * no longer in the queue!
3264 * @param tq Handle to the queue entry to cancel.
3267 GCT_send_cancel (struct CadetTunnelQueueEntry *tq)
3269 struct CadetTunnel *t = tq->t;
3271 GNUNET_CONTAINER_DLL_remove (t->tq_head,
3274 GNUNET_MQ_discard (tq->env);
3280 * Iterate over all connections of a tunnel.
3282 * @param t Tunnel whose connections to iterate.
3283 * @param iter Iterator.
3284 * @param iter_cls Closure for @c iter.
3287 GCT_iterate_connections (struct CadetTunnel *t,
3288 GCT_ConnectionIterator iter,
3291 struct CadetTConnection *n;
3292 for (struct CadetTConnection *ct = t->connection_ready_head;
3300 for (struct CadetTConnection *ct = t->connection_busy_head;
3312 * Closure for #iterate_channels_cb.
3319 GCT_ChannelIterator iter;
3322 * Closure for @e iter.
3329 * Helper function for #GCT_iterate_channels.
3331 * @param cls the `struct ChanIterCls`
3333 * @param value a `struct CadetChannel`
3334 * @return #GNUNET_OK
3337 iterate_channels_cb (void *cls,
3341 struct ChanIterCls *ctx = cls;
3342 struct CadetChannel *ch = value;
3344 ctx->iter (ctx->iter_cls,
3351 * Iterate over all channels of a tunnel.
3353 * @param t Tunnel whose channels to iterate.
3354 * @param iter Iterator.
3355 * @param iter_cls Closure for @c iter.
3358 GCT_iterate_channels (struct CadetTunnel *t,
3359 GCT_ChannelIterator iter,
3362 struct ChanIterCls ctx;
3365 ctx.iter_cls = iter_cls;
3366 GNUNET_CONTAINER_multihashmap32_iterate (t->channels,
3367 &iterate_channels_cb,
3374 * Call #GCCH_debug() on a channel.
3376 * @param cls points to the log level to use
3378 * @param value the `struct CadetChannel` to dump
3379 * @return #GNUNET_OK (continue iteration)
3382 debug_channel (void *cls,
3386 const enum GNUNET_ErrorType *level = cls;
3387 struct CadetChannel *ch = value;
3389 GCCH_debug (ch, *level);
3394 #define LOG2(level, ...) GNUNET_log_from_nocheck(level,"cadet-tun",__VA_ARGS__)
3398 * Log all possible info about the tunnel state.
3400 * @param t Tunnel to debug.
3401 * @param level Debug level to use.
3404 GCT_debug (const struct CadetTunnel *t,
3405 enum GNUNET_ErrorType level)
3407 struct CadetTConnection *iter_c;
3410 do_log = GNUNET_get_log_call_status (level & (~GNUNET_ERROR_TYPE_BULK),
3412 __FILE__, __FUNCTION__, __LINE__);
3417 "TTT TUNNEL TOWARDS %s in estate %s tq_len: %u #cons: %u\n",
3419 estate2s (t->estate),
3421 GCT_count_any_connections (t));
3424 GNUNET_CONTAINER_multihashmap32_iterate (t->channels,
3428 "TTT connections:\n");
3429 for (iter_c = t->connection_ready_head; NULL != iter_c; iter_c = iter_c->next)
3430 GCC_debug (iter_c->cc,
3432 for (iter_c = t->connection_busy_head; NULL != iter_c; iter_c = iter_c->next)
3433 GCC_debug (iter_c->cc,
3437 "TTT TUNNEL END\n");
3441 /* end of gnunet-service-cadet-new_tunnels.c */