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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 * + when managing connections, distinguish those that
29 * have (recently) had traffic from those that were
30 * never ready (or not recently)
31 * + consider quality of current connection set when deciding
32 * how often to do maintenance
33 * + interact with PEER to drive DHT GET/PUT operations based
34 * on how much we like our connections
37 #include "gnunet_util_lib.h"
38 #include "gnunet_statistics_service.h"
39 #include "gnunet_signatures.h"
40 #include "gnunet-service-cadet-new.h"
41 #include "cadet_protocol.h"
42 #include "gnunet-service-cadet-new_channel.h"
43 #include "gnunet-service-cadet-new_connection.h"
44 #include "gnunet-service-cadet-new_tunnels.h"
45 #include "gnunet-service-cadet-new_peer.h"
46 #include "gnunet-service-cadet-new_paths.h"
49 #define LOG(level, ...) GNUNET_log_from(level,"cadet-tun",__VA_ARGS__)
52 * How often do we try to decrypt payload with unverified key
53 * material? Used to limit CPU increase upon receiving bogus
56 #define MAX_UNVERIFIED_ATTEMPTS 16
59 * How long do we wait until tearing down an idle tunnel?
61 #define IDLE_DESTROY_DELAY GNUNET_TIME_relative_multiply(GNUNET_TIME_UNIT_SECONDS, 90)
64 * How long do we wait initially before retransmitting the KX?
65 * TODO: replace by 2 RTT if/once we have connection-level RTT data!
67 #define INITIAL_KX_RETRY_DELAY GNUNET_TIME_relative_multiply(GNUNET_TIME_UNIT_MILLISECONDS, 250)
70 * Maximum number of skipped keys we keep in memory per tunnel.
72 #define MAX_SKIPPED_KEYS 64
75 * Maximum number of keys (and thus ratchet steps) we are willing to
76 * skip before we decide this is either a bogus packet or a DoS-attempt.
78 #define MAX_KEY_GAP 256
82 * Struct to old keys for skipped messages while advancing the Axolotl ratchet.
84 struct CadetTunnelSkippedKey
89 struct CadetTunnelSkippedKey *next;
94 struct CadetTunnelSkippedKey *prev;
97 * When was this key stored (for timeout).
99 struct GNUNET_TIME_Absolute timestamp;
104 struct GNUNET_CRYPTO_SymmetricSessionKey HK;
109 struct GNUNET_CRYPTO_SymmetricSessionKey MK;
112 * Key number for a given HK.
119 * Axolotl data, according to https://github.com/trevp/axolotl/wiki .
121 struct CadetTunnelAxolotl
124 * A (double linked) list of stored message keys and associated header keys
125 * for "skipped" messages, i.e. messages that have not been
126 * received despite the reception of more recent messages, (head).
128 struct CadetTunnelSkippedKey *skipped_head;
131 * Skipped messages' keys DLL, tail.
133 struct CadetTunnelSkippedKey *skipped_tail;
136 * 32-byte root key which gets updated by DH ratchet.
138 struct GNUNET_CRYPTO_SymmetricSessionKey RK;
141 * 32-byte header key (currently used for sending).
143 struct GNUNET_CRYPTO_SymmetricSessionKey HKs;
146 * 32-byte header key (currently used for receiving)
148 struct GNUNET_CRYPTO_SymmetricSessionKey HKr;
151 * 32-byte next header key (for sending), used once the
152 * ratchet advances. We are sure that the sender has this
153 * key as well only after @e ratchet_allowed is #GNUNET_YES.
155 struct GNUNET_CRYPTO_SymmetricSessionKey NHKs;
158 * 32-byte next header key (for receiving). To be tried
159 * when decrypting with @e HKr fails and thus the sender
160 * may have advanced the ratchet.
162 struct GNUNET_CRYPTO_SymmetricSessionKey NHKr;
165 * 32-byte chain keys (used for forward-secrecy) for
166 * sending messages. Updated for every message.
168 struct GNUNET_CRYPTO_SymmetricSessionKey CKs;
171 * 32-byte chain keys (used for forward-secrecy) for
172 * receiving messages. Updated for every message. If
173 * messages are skipped, the respective derived MKs
174 * (and the current @HKr) are kept in the @e skipped_head DLL.
176 struct GNUNET_CRYPTO_SymmetricSessionKey CKr;
179 * ECDH for key exchange (A0 / B0). Note that for the
180 * 'unverified_ax', this member is an alias with the main
181 * 't->ax.kx_0' value, so do not free it!
183 struct GNUNET_CRYPTO_EcdhePrivateKey *kx_0;
186 * ECDH Ratchet key (our private key in the current DH). Note that
187 * for the 'unverified_ax', this member is an alias with the main
188 * 't->ax.kx_0' value, so do not free it!
190 struct GNUNET_CRYPTO_EcdhePrivateKey *DHRs;
193 * ECDH Ratchet key (other peer's public key in the current DH).
195 struct GNUNET_CRYPTO_EcdhePublicKey DHRr;
198 * Time when the current ratchet expires and a new one is triggered
199 * (if @e ratchet_allowed is #GNUNET_YES).
201 struct GNUNET_TIME_Absolute ratchet_expiration;
204 * Number of elements in @a skipped_head <-> @a skipped_tail.
206 unsigned int skipped;
209 * Message number (reset to 0 with each new ratchet, next message to send).
214 * Message number (reset to 0 with each new ratchet, next message to recv).
219 * Previous message numbers (# of msgs sent under prev ratchet)
224 * True (#GNUNET_YES) if we have to send a new ratchet key in next msg.
229 * True (#GNUNET_YES) if we have received a message from the
230 * other peer that uses the keys from our last ratchet step.
231 * This implies that we are again allowed to advance the ratchet,
232 * otherwise we have to wait until the other peer sees our current
233 * ephemeral key and advances first.
235 * #GNUNET_NO if we have advanced the ratched but lack any evidence
236 * that the other peer has noticed this.
241 * Number of messages recieved since our last ratchet advance.
243 * If this counter = 0, we cannot send a new ratchet key in the next
246 * If this counter > 0, we could (but don't have to) send a new key.
248 * Once the @e ratchet_counter is larger than
249 * #ratchet_messages (or @e ratchet_expiration time has past), and
250 * @e ratchet_allowed is #GNUNET_YES, we advance the ratchet.
252 unsigned int ratchet_counter;
258 * Struct used to save messages in a non-ready tunnel to send once connected.
260 struct CadetTunnelQueueEntry
263 * We are entries in a DLL
265 struct CadetTunnelQueueEntry *next;
268 * We are entries in a DLL
270 struct CadetTunnelQueueEntry *prev;
273 * Tunnel these messages belong in.
275 struct CadetTunnel *t;
278 * Continuation to call once sent (on the channel layer).
280 GCT_SendContinuation cont;
283 * Closure for @c cont.
288 * Envelope of message to send follows.
290 struct GNUNET_MQ_Envelope *env;
293 * Where to put the connection identifier into the payload
294 * of the message in @e env once we have it?
296 struct GNUNET_CADET_ConnectionTunnelIdentifier *cid;
301 * Struct containing all information regarding a tunnel to a peer.
306 * Destination of the tunnel.
308 struct CadetPeer *destination;
311 * Peer's ephemeral key, to recreate @c e_key and @c d_key when own
312 * ephemeral key changes.
314 struct GNUNET_CRYPTO_EcdhePublicKey peers_ephemeral_key;
317 * Encryption ("our") key. It is only "confirmed" if kx_ctx is NULL.
319 struct GNUNET_CRYPTO_SymmetricSessionKey e_key;
322 * Decryption ("their") key. It is only "confirmed" if kx_ctx is NULL.
324 struct GNUNET_CRYPTO_SymmetricSessionKey d_key;
329 struct CadetTunnelAxolotl ax;
332 * Unverified Axolotl info, used only if we got a fresh KX (not a
333 * KX_AUTH) while our end of the tunnel was still up. In this case,
334 * we keep the fresh KX around but do not put it into action until
335 * we got encrypted payload that assures us of the authenticity of
338 struct CadetTunnelAxolotl *unverified_ax;
341 * Task scheduled if there are no more channels using the tunnel.
343 struct GNUNET_SCHEDULER_Task *destroy_task;
346 * Task to trim connections if too many are present.
348 struct GNUNET_SCHEDULER_Task *maintain_connections_task;
351 * Task to send messages from queue (if possible).
353 struct GNUNET_SCHEDULER_Task *send_task;
356 * Task to trigger KX.
358 struct GNUNET_SCHEDULER_Task *kx_task;
361 * Tokenizer for decrypted messages.
363 struct GNUNET_MessageStreamTokenizer *mst;
366 * Dispatcher for decrypted messages only (do NOT use for sending!).
368 struct GNUNET_MQ_Handle *mq;
371 * DLL of ready connections that are actively used to reach the destination peer.
373 struct CadetTConnection *connection_ready_head;
376 * DLL of ready connections that are actively used to reach the destination peer.
378 struct CadetTConnection *connection_ready_tail;
381 * DLL of connections that we maintain that might be used to reach the destination peer.
383 struct CadetTConnection *connection_busy_head;
386 * DLL of connections that we maintain that might be used to reach the destination peer.
388 struct CadetTConnection *connection_busy_tail;
391 * Channels inside this tunnel. Maps
392 * `struct GNUNET_CADET_ChannelTunnelNumber` to a `struct CadetChannel`.
394 struct GNUNET_CONTAINER_MultiHashMap32 *channels;
397 * Channel ID for the next created channel in this tunnel.
399 struct GNUNET_CADET_ChannelTunnelNumber next_ctn;
402 * Queued messages, to transmit once tunnel gets connected.
404 struct CadetTunnelQueueEntry *tq_head;
407 * Queued messages, to transmit once tunnel gets connected.
409 struct CadetTunnelQueueEntry *tq_tail;
412 * Identification of the connection from which we are currently processing
413 * a message. Only valid (non-NULL) during #handle_decrypted() and the
414 * handle-*()-functions called from our @e mq during that function.
416 struct CadetTConnection *current_ct;
419 * How long do we wait until we retry the KX?
421 struct GNUNET_TIME_Relative kx_retry_delay;
424 * When do we try the next KX?
426 struct GNUNET_TIME_Absolute next_kx_attempt;
429 * Number of connections in the @e connection_ready_head DLL.
431 unsigned int num_ready_connections;
434 * Number of connections in the @e connection_busy_head DLL.
436 unsigned int num_busy_connections;
439 * How often have we tried and failed to decrypt a message using
440 * the unverified KX material from @e unverified_ax? Used to
441 * stop trying after #MAX_UNVERIFIED_ATTEMPTS.
443 unsigned int unverified_attempts;
446 * Number of entries in the @e tq_head DLL.
451 * State of the tunnel encryption.
453 enum CadetTunnelEState estate;
456 * Force triggering KX_AUTH independent of @e estate.
458 int kx_auth_requested;
464 * Connection @a ct is now unready, clear it's ready flag
465 * and move it from the ready DLL to the busy DLL.
467 * @param ct connection to move to unready status
470 mark_connection_unready (struct CadetTConnection *ct)
472 struct CadetTunnel *t = ct->t;
474 GNUNET_assert (GNUNET_YES == ct->is_ready);
475 GNUNET_CONTAINER_DLL_remove (t->connection_ready_head,
476 t->connection_ready_tail,
478 GNUNET_assert (0 < t->num_ready_connections);
479 t->num_ready_connections--;
480 ct->is_ready = GNUNET_NO;
481 GNUNET_CONTAINER_DLL_insert (t->connection_busy_head,
482 t->connection_busy_tail,
484 t->num_busy_connections++;
489 * Get the static string for the peer this tunnel is directed.
493 * @return Static string the destination peer's ID.
496 GCT_2s (const struct CadetTunnel *t)
501 return "Tunnel(NULL)";
502 GNUNET_snprintf (buf,
505 GNUNET_i2s (GCP_get_id (t->destination)));
511 * Get string description for tunnel encryption state.
513 * @param es Tunnel state.
515 * @return String representation.
518 estate2s (enum CadetTunnelEState es)
524 case CADET_TUNNEL_KEY_UNINITIALIZED:
525 return "CADET_TUNNEL_KEY_UNINITIALIZED";
526 case CADET_TUNNEL_KEY_AX_RECV:
527 return "CADET_TUNNEL_KEY_AX_RECV";
528 case CADET_TUNNEL_KEY_AX_SENT:
529 return "CADET_TUNNEL_KEY_AX_SENT";
530 case CADET_TUNNEL_KEY_AX_SENT_AND_RECV:
531 return "CADET_TUNNEL_KEY_AX_SENT_AND_RECV";
532 case CADET_TUNNEL_KEY_AX_AUTH_SENT:
533 return "CADET_TUNNEL_KEY_AX_AUTH_SENT";
534 case CADET_TUNNEL_KEY_OK:
535 return "CADET_TUNNEL_KEY_OK";
537 GNUNET_snprintf (buf,
539 "%u (UNKNOWN STATE)",
547 * Return the peer to which this tunnel goes.
550 * @return the destination of the tunnel
553 GCT_get_destination (struct CadetTunnel *t)
555 return t->destination;
560 * Count channels of a tunnel.
562 * @param t Tunnel on which to count.
564 * @return Number of channels.
567 GCT_count_channels (struct CadetTunnel *t)
569 return GNUNET_CONTAINER_multihashmap32_size (t->channels);
574 * Lookup a channel by its @a ctn.
576 * @param t tunnel to look in
577 * @param ctn number of channel to find
578 * @return NULL if channel does not exist
580 struct CadetChannel *
581 lookup_channel (struct CadetTunnel *t,
582 struct GNUNET_CADET_ChannelTunnelNumber ctn)
584 return GNUNET_CONTAINER_multihashmap32_get (t->channels,
590 * Count all created connections of a tunnel. Not necessarily ready connections!
592 * @param t Tunnel on which to count.
594 * @return Number of connections created, either being established or ready.
597 GCT_count_any_connections (const struct CadetTunnel *t)
599 return t->num_ready_connections + t->num_busy_connections;
604 * Find first connection that is ready in the list of
605 * our connections. Picks ready connections round-robin.
607 * @param t tunnel to search
608 * @return NULL if we have no connection that is ready
610 static struct CadetTConnection *
611 get_ready_connection (struct CadetTunnel *t)
613 return t->connection_ready_head;
618 * Get the encryption state of a tunnel.
622 * @return Tunnel's encryption state.
624 enum CadetTunnelEState
625 GCT_get_estate (struct CadetTunnel *t)
632 * Called when either we have a new connection, or a new message in the
633 * queue, or some existing connection has transmission capacity. Looks
634 * at our message queue and if there is a message, picks a connection
637 * @param cls the `struct CadetTunnel` to process messages on
640 trigger_transmissions (void *cls);
643 /* ************************************** start core crypto ***************************** */
647 * Create a new Axolotl ephemeral (ratchet) key.
649 * @param ax key material to update
652 new_ephemeral (struct CadetTunnelAxolotl *ax)
654 GNUNET_free_non_null (ax->DHRs);
655 LOG (GNUNET_ERROR_TYPE_DEBUG,
656 "Creating new ephemeral ratchet key (DHRs)\n");
657 ax->DHRs = GNUNET_CRYPTO_ecdhe_key_create ();
664 * @param plaintext Content to HMAC.
665 * @param size Size of @c plaintext.
666 * @param iv Initialization vector for the message.
667 * @param key Key to use.
668 * @param hmac[out] Destination to store the HMAC.
671 t_hmac (const void *plaintext,
674 const struct GNUNET_CRYPTO_SymmetricSessionKey *key,
675 struct GNUNET_ShortHashCode *hmac)
677 static const char ctx[] = "cadet authentication key";
678 struct GNUNET_CRYPTO_AuthKey auth_key;
679 struct GNUNET_HashCode hash;
681 GNUNET_CRYPTO_hmac_derive_key (&auth_key,
687 /* Two step: GNUNET_ShortHash is only 256 bits,
688 GNUNET_HashCode is 512, so we truncate. */
689 GNUNET_CRYPTO_hmac (&auth_key,
702 * @param key Key to use.
703 * @param[out] hash Resulting HMAC.
704 * @param source Source key material (data to HMAC).
705 * @param len Length of @a source.
708 t_ax_hmac_hash (const struct GNUNET_CRYPTO_SymmetricSessionKey *key,
709 struct GNUNET_HashCode *hash,
713 static const char ctx[] = "axolotl HMAC-HASH";
714 struct GNUNET_CRYPTO_AuthKey auth_key;
716 GNUNET_CRYPTO_hmac_derive_key (&auth_key,
720 GNUNET_CRYPTO_hmac (&auth_key,
728 * Derive a symmetric encryption key from an HMAC-HASH.
730 * @param key Key to use for the HMAC.
731 * @param[out] out Key to generate.
732 * @param source Source key material (data to HMAC).
733 * @param len Length of @a source.
736 t_hmac_derive_key (const struct GNUNET_CRYPTO_SymmetricSessionKey *key,
737 struct GNUNET_CRYPTO_SymmetricSessionKey *out,
741 static const char ctx[] = "axolotl derive key";
742 struct GNUNET_HashCode h;
748 GNUNET_CRYPTO_kdf (out, sizeof (*out),
756 * Encrypt data with the axolotl tunnel key.
758 * @param ax key material to use.
759 * @param dst Destination with @a size bytes for the encrypted data.
760 * @param src Source of the plaintext. Can overlap with @c dst, must contain @a size bytes
761 * @param size Size of the buffers at @a src and @a dst
764 t_ax_encrypt (struct CadetTunnelAxolotl *ax,
769 struct GNUNET_CRYPTO_SymmetricSessionKey MK;
770 struct GNUNET_CRYPTO_SymmetricInitializationVector iv;
773 ax->ratchet_counter++;
774 if ( (GNUNET_YES == ax->ratchet_allowed) &&
775 ( (ratchet_messages <= ax->ratchet_counter) ||
776 (0 == GNUNET_TIME_absolute_get_remaining (ax->ratchet_expiration).rel_value_us)) )
778 ax->ratchet_flag = GNUNET_YES;
780 if (GNUNET_YES == ax->ratchet_flag)
782 /* Advance ratchet */
783 struct GNUNET_CRYPTO_SymmetricSessionKey keys[3];
784 struct GNUNET_HashCode dh;
785 struct GNUNET_HashCode hmac;
786 static const char ctx[] = "axolotl ratchet";
791 /* RK, NHKs, CKs = KDF( HMAC-HASH(RK, DH(DHRs, DHRr)) ) */
792 GNUNET_CRYPTO_ecc_ecdh (ax->DHRs,
795 t_ax_hmac_hash (&ax->RK,
799 GNUNET_CRYPTO_kdf (keys, sizeof (keys),
801 &hmac, sizeof (hmac),
809 ax->ratchet_flag = GNUNET_NO;
810 ax->ratchet_allowed = GNUNET_NO;
811 ax->ratchet_counter = 0;
812 ax->ratchet_expiration
813 = GNUNET_TIME_absolute_add (GNUNET_TIME_absolute_get(),
817 t_hmac_derive_key (&ax->CKs,
821 GNUNET_CRYPTO_symmetric_derive_iv (&iv,
826 out_size = GNUNET_CRYPTO_symmetric_encrypt (src,
831 GNUNET_assert (size == out_size);
832 t_hmac_derive_key (&ax->CKs,
840 * Decrypt data with the axolotl tunnel key.
842 * @param ax key material to use.
843 * @param dst Destination for the decrypted data, must contain @a size bytes.
844 * @param src Source of the ciphertext. Can overlap with @c dst, must contain @a size bytes.
845 * @param size Size of the @a src and @a dst buffers
848 t_ax_decrypt (struct CadetTunnelAxolotl *ax,
853 struct GNUNET_CRYPTO_SymmetricSessionKey MK;
854 struct GNUNET_CRYPTO_SymmetricInitializationVector iv;
857 t_hmac_derive_key (&ax->CKr,
861 GNUNET_CRYPTO_symmetric_derive_iv (&iv,
865 GNUNET_assert (size >= sizeof (struct GNUNET_MessageHeader));
866 out_size = GNUNET_CRYPTO_symmetric_decrypt (src,
871 GNUNET_assert (out_size == size);
872 t_hmac_derive_key (&ax->CKr,
880 * Encrypt header with the axolotl header key.
882 * @param ax key material to use.
883 * @param[in|out] msg Message whose header to encrypt.
886 t_h_encrypt (struct CadetTunnelAxolotl *ax,
887 struct GNUNET_CADET_TunnelEncryptedMessage *msg)
889 struct GNUNET_CRYPTO_SymmetricInitializationVector iv;
892 GNUNET_CRYPTO_symmetric_derive_iv (&iv,
896 out_size = GNUNET_CRYPTO_symmetric_encrypt (&msg->ax_header,
897 sizeof (struct GNUNET_CADET_AxHeader),
901 GNUNET_assert (sizeof (struct GNUNET_CADET_AxHeader) == out_size);
906 * Decrypt header with the current axolotl header key.
908 * @param ax key material to use.
909 * @param src Message whose header to decrypt.
910 * @param dst Where to decrypt header to.
913 t_h_decrypt (struct CadetTunnelAxolotl *ax,
914 const struct GNUNET_CADET_TunnelEncryptedMessage *src,
915 struct GNUNET_CADET_TunnelEncryptedMessage *dst)
917 struct GNUNET_CRYPTO_SymmetricInitializationVector iv;
920 GNUNET_CRYPTO_symmetric_derive_iv (&iv,
924 out_size = GNUNET_CRYPTO_symmetric_decrypt (&src->ax_header.Ns,
925 sizeof (struct GNUNET_CADET_AxHeader),
929 GNUNET_assert (sizeof (struct GNUNET_CADET_AxHeader) == out_size);
934 * Delete a key from the list of skipped keys.
936 * @param ax key material to delete @a key from.
937 * @param key Key to delete.
940 delete_skipped_key (struct CadetTunnelAxolotl *ax,
941 struct CadetTunnelSkippedKey *key)
943 GNUNET_CONTAINER_DLL_remove (ax->skipped_head,
952 * Decrypt and verify data with the appropriate tunnel key and verify that the
953 * data has not been altered since it was sent by the remote peer.
955 * @param ax key material to use.
956 * @param dst Destination for the plaintext.
957 * @param src Source of the message. Can overlap with @c dst.
958 * @param size Size of the message.
959 * @return Size of the decrypted data, -1 if an error was encountered.
962 try_old_ax_keys (struct CadetTunnelAxolotl *ax,
964 const struct GNUNET_CADET_TunnelEncryptedMessage *src,
967 struct CadetTunnelSkippedKey *key;
968 struct GNUNET_ShortHashCode *hmac;
969 struct GNUNET_CRYPTO_SymmetricInitializationVector iv;
970 struct GNUNET_CADET_TunnelEncryptedMessage plaintext_header;
971 struct GNUNET_CRYPTO_SymmetricSessionKey *valid_HK;
977 LOG (GNUNET_ERROR_TYPE_DEBUG,
978 "Trying skipped keys\n");
979 hmac = &plaintext_header.hmac;
980 esize = size - sizeof (struct GNUNET_CADET_TunnelEncryptedMessage);
982 /* Find a correct Header Key */
984 for (key = ax->skipped_head; NULL != key; key = key->next)
986 t_hmac (&src->ax_header,
987 sizeof (struct GNUNET_CADET_AxHeader) + esize,
991 if (0 == memcmp (hmac,
1002 /* Should've been checked in -cadet_connection.c handle_cadet_encrypted. */
1003 GNUNET_assert (size > sizeof (struct GNUNET_CADET_TunnelEncryptedMessage));
1004 len = size - sizeof (struct GNUNET_CADET_TunnelEncryptedMessage);
1005 GNUNET_assert (len >= sizeof (struct GNUNET_MessageHeader));
1007 /* Decrypt header */
1008 GNUNET_CRYPTO_symmetric_derive_iv (&iv,
1012 res = GNUNET_CRYPTO_symmetric_decrypt (&src->ax_header.Ns,
1013 sizeof (struct GNUNET_CADET_AxHeader),
1016 &plaintext_header.ax_header.Ns);
1017 GNUNET_assert (sizeof (struct GNUNET_CADET_AxHeader) == res);
1019 /* Find the correct message key */
1020 N = ntohl (plaintext_header.ax_header.Ns);
1021 while ( (NULL != key) &&
1024 if ( (NULL == key) ||
1025 (0 != memcmp (&key->HK,
1027 sizeof (*valid_HK))) )
1030 /* Decrypt payload */
1031 GNUNET_CRYPTO_symmetric_derive_iv (&iv,
1036 res = GNUNET_CRYPTO_symmetric_decrypt (&src[1],
1041 delete_skipped_key (ax,
1048 * Delete a key from the list of skipped keys.
1050 * @param ax key material to delete from.
1051 * @param HKr Header Key to use.
1054 store_skipped_key (struct CadetTunnelAxolotl *ax,
1055 const struct GNUNET_CRYPTO_SymmetricSessionKey *HKr)
1057 struct CadetTunnelSkippedKey *key;
1059 key = GNUNET_new (struct CadetTunnelSkippedKey);
1060 key->timestamp = GNUNET_TIME_absolute_get ();
1063 t_hmac_derive_key (&ax->CKr,
1067 t_hmac_derive_key (&ax->CKr,
1071 GNUNET_CONTAINER_DLL_insert (ax->skipped_head,
1080 * Stage skipped AX keys and calculate the message key.
1081 * Stores each HK and MK for skipped messages.
1083 * @param ax key material to use
1084 * @param HKr Header key.
1085 * @param Np Received meesage number.
1086 * @return #GNUNET_OK if keys were stored.
1087 * #GNUNET_SYSERR if an error ocurred (@a Np not expected).
1090 store_ax_keys (struct CadetTunnelAxolotl *ax,
1091 const struct GNUNET_CRYPTO_SymmetricSessionKey *HKr,
1097 LOG (GNUNET_ERROR_TYPE_DEBUG,
1098 "Storing skipped keys [%u, %u)\n",
1101 if (MAX_KEY_GAP < gap)
1103 /* Avoid DoS (forcing peer to do more than #MAX_KEY_GAP HMAC operations) */
1104 /* TODO: start new key exchange on return */
1105 GNUNET_break_op (0);
1106 LOG (GNUNET_ERROR_TYPE_WARNING,
1107 "Got message %u, expected %u+\n",
1110 return GNUNET_SYSERR;
1114 /* Delayed message: don't store keys, flag to try old keys. */
1115 return GNUNET_SYSERR;
1119 store_skipped_key (ax,
1122 while (ax->skipped > MAX_SKIPPED_KEYS)
1123 delete_skipped_key (ax,
1130 * Decrypt and verify data with the appropriate tunnel key and verify that the
1131 * data has not been altered since it was sent by the remote peer.
1133 * @param ax key material to use
1134 * @param dst Destination for the plaintext.
1135 * @param src Source of the message. Can overlap with @c dst.
1136 * @param size Size of the message.
1137 * @return Size of the decrypted data, -1 if an error was encountered.
1140 t_ax_decrypt_and_validate (struct CadetTunnelAxolotl *ax,
1142 const struct GNUNET_CADET_TunnelEncryptedMessage *src,
1145 struct GNUNET_ShortHashCode msg_hmac;
1146 struct GNUNET_HashCode hmac;
1147 struct GNUNET_CADET_TunnelEncryptedMessage plaintext_header;
1150 size_t esize; /* Size of encryped payload */
1152 esize = size - sizeof (struct GNUNET_CADET_TunnelEncryptedMessage);
1154 /* Try current HK */
1155 t_hmac (&src->ax_header,
1156 sizeof (struct GNUNET_CADET_AxHeader) + esize,
1159 if (0 != memcmp (&msg_hmac,
1163 static const char ctx[] = "axolotl ratchet";
1164 struct GNUNET_CRYPTO_SymmetricSessionKey keys[3]; /* RKp, NHKp, CKp */
1165 struct GNUNET_CRYPTO_SymmetricSessionKey HK;
1166 struct GNUNET_HashCode dh;
1167 struct GNUNET_CRYPTO_EcdhePublicKey *DHRp;
1170 t_hmac (&src->ax_header,
1171 sizeof (struct GNUNET_CADET_AxHeader) + esize,
1175 if (0 != memcmp (&msg_hmac,
1179 /* Try the skipped keys, if that fails, we're out of luck. */
1180 return try_old_ax_keys (ax,
1190 Np = ntohl (plaintext_header.ax_header.Ns);
1191 PNp = ntohl (plaintext_header.ax_header.PNs);
1192 DHRp = &plaintext_header.ax_header.DHRs;
1197 /* RKp, NHKp, CKp = KDF (HMAC-HASH (RK, DH (DHRp, DHRs))) */
1198 GNUNET_CRYPTO_ecc_ecdh (ax->DHRs,
1201 t_ax_hmac_hash (&ax->RK,
1204 GNUNET_CRYPTO_kdf (keys, sizeof (keys),
1206 &hmac, sizeof (hmac),
1209 /* Commit "purported" keys */
1215 ax->ratchet_allowed = GNUNET_YES;
1222 Np = ntohl (plaintext_header.ax_header.Ns);
1223 PNp = ntohl (plaintext_header.ax_header.PNs);
1225 if ( (Np != ax->Nr) &&
1226 (GNUNET_OK != store_ax_keys (ax,
1230 /* Try the skipped keys, if that fails, we're out of luck. */
1231 return try_old_ax_keys (ax,
1247 * Our tunnel became ready for the first time, notify channels
1248 * that have been waiting.
1250 * @param cls our tunnel, not used
1251 * @param key unique ID of the channel, not used
1252 * @param value the `struct CadetChannel` to notify
1253 * @return #GNUNET_OK (continue to iterate)
1256 notify_tunnel_up_cb (void *cls,
1260 struct CadetChannel *ch = value;
1262 GCCH_tunnel_up (ch);
1268 * Change the tunnel encryption state.
1269 * If the encryption state changes to OK, stop the rekey task.
1271 * @param t Tunnel whose encryption state to change, or NULL.
1272 * @param state New encryption state.
1275 GCT_change_estate (struct CadetTunnel *t,
1276 enum CadetTunnelEState state)
1278 enum CadetTunnelEState old = t->estate;
1281 LOG (GNUNET_ERROR_TYPE_DEBUG,
1282 "%s estate changed from %s to %s\n",
1287 if ( (CADET_TUNNEL_KEY_OK != old) &&
1288 (CADET_TUNNEL_KEY_OK == t->estate) )
1290 if (NULL != t->kx_task)
1292 GNUNET_SCHEDULER_cancel (t->kx_task);
1295 /* notify all channels that have been waiting */
1296 GNUNET_CONTAINER_multihashmap32_iterate (t->channels,
1297 ¬ify_tunnel_up_cb,
1299 if (NULL != t->send_task)
1300 GNUNET_SCHEDULER_cancel (t->send_task);
1301 t->send_task = GNUNET_SCHEDULER_add_now (&trigger_transmissions,
1308 * Send a KX message.
1310 * @param t tunnel on which to send the KX_AUTH
1311 * @param ct Tunnel and connection on which to send the KX_AUTH, NULL if
1312 * we are to find one that is ready.
1313 * @param ax axolotl key context to use
1316 send_kx (struct CadetTunnel *t,
1317 struct CadetTConnection *ct,
1318 struct CadetTunnelAxolotl *ax)
1320 struct CadetConnection *cc;
1321 struct GNUNET_MQ_Envelope *env;
1322 struct GNUNET_CADET_TunnelKeyExchangeMessage *msg;
1323 enum GNUNET_CADET_KX_Flags flags;
1326 ct = get_ready_connection (t);
1329 LOG (GNUNET_ERROR_TYPE_DEBUG,
1330 "Wanted to send %s in state %s, but no connection is ready, deferring\n",
1332 estate2s (t->estate));
1333 t->next_kx_attempt = GNUNET_TIME_absolute_get ();
1337 LOG (GNUNET_ERROR_TYPE_DEBUG,
1338 "Sending KX on %s via %s using %s in state %s\n",
1341 estate2s (t->estate));
1342 env = GNUNET_MQ_msg (msg,
1343 GNUNET_MESSAGE_TYPE_CADET_TUNNEL_KX);
1344 flags = GNUNET_CADET_KX_FLAG_FORCE_REPLY; /* always for KX */
1345 msg->flags = htonl (flags);
1346 msg->cid = *GCC_get_id (cc);
1347 GNUNET_CRYPTO_ecdhe_key_get_public (ax->kx_0,
1348 &msg->ephemeral_key);
1349 GNUNET_CRYPTO_ecdhe_key_get_public (ax->DHRs,
1351 mark_connection_unready (ct);
1352 t->kx_retry_delay = GNUNET_TIME_STD_BACKOFF (t->kx_retry_delay);
1353 t->next_kx_attempt = GNUNET_TIME_relative_to_absolute (t->kx_retry_delay);
1354 if (CADET_TUNNEL_KEY_UNINITIALIZED == t->estate)
1355 GCT_change_estate (t,
1356 CADET_TUNNEL_KEY_AX_SENT);
1357 else if (CADET_TUNNEL_KEY_AX_RECV == t->estate)
1358 GCT_change_estate (t,
1359 CADET_TUNNEL_KEY_AX_SENT_AND_RECV);
1366 * Send a KX_AUTH message.
1368 * @param t tunnel on which to send the KX_AUTH
1369 * @param ct Tunnel and connection on which to send the KX_AUTH, NULL if
1370 * we are to find one that is ready.
1371 * @param ax axolotl key context to use
1372 * @param force_reply Force the other peer to reply with a KX_AUTH message
1373 * (set if we would like to transmit right now, but cannot)
1376 send_kx_auth (struct CadetTunnel *t,
1377 struct CadetTConnection *ct,
1378 struct CadetTunnelAxolotl *ax,
1381 struct CadetConnection *cc;
1382 struct GNUNET_MQ_Envelope *env;
1383 struct GNUNET_CADET_TunnelKeyExchangeAuthMessage *msg;
1384 enum GNUNET_CADET_KX_Flags flags;
1386 if ( (NULL == ct) ||
1387 (GNUNET_NO == ct->is_ready) )
1388 ct = get_ready_connection (t);
1391 LOG (GNUNET_ERROR_TYPE_DEBUG,
1392 "Wanted to send KX_AUTH on %s, but no connection is ready, deferring\n",
1394 t->next_kx_attempt = GNUNET_TIME_absolute_get ();
1395 t->kx_auth_requested = GNUNET_YES; /* queue KX_AUTH independent of estate */
1398 t->kx_auth_requested = GNUNET_NO; /* clear flag */
1400 LOG (GNUNET_ERROR_TYPE_DEBUG,
1401 "Sending KX_AUTH on %s using %s\n",
1405 env = GNUNET_MQ_msg (msg,
1406 GNUNET_MESSAGE_TYPE_CADET_TUNNEL_KX_AUTH);
1407 flags = GNUNET_CADET_KX_FLAG_NONE;
1408 if (GNUNET_YES == force_reply)
1409 flags |= GNUNET_CADET_KX_FLAG_FORCE_REPLY;
1410 msg->kx.flags = htonl (flags);
1411 msg->kx.cid = *GCC_get_id (cc);
1412 GNUNET_CRYPTO_ecdhe_key_get_public (ax->kx_0,
1413 &msg->kx.ephemeral_key);
1414 GNUNET_CRYPTO_ecdhe_key_get_public (ax->DHRs,
1415 &msg->kx.ratchet_key);
1416 /* Compute authenticator (this is the main difference to #send_kx()) */
1417 GNUNET_CRYPTO_hash (&ax->RK,
1421 /* Compute when to be triggered again; actual job will
1422 be scheduled via #connection_ready_cb() */
1424 = GNUNET_TIME_STD_BACKOFF (t->kx_retry_delay);
1426 = GNUNET_TIME_relative_to_absolute (t->kx_retry_delay);
1428 /* Send via cc, mark it as unready */
1429 mark_connection_unready (ct);
1431 /* Update state machine, unless we are already OK */
1432 if (CADET_TUNNEL_KEY_OK != t->estate)
1433 GCT_change_estate (t,
1434 CADET_TUNNEL_KEY_AX_AUTH_SENT);
1442 * Cleanup state used by @a ax.
1444 * @param ax state to free, but not memory of @a ax itself
1447 cleanup_ax (struct CadetTunnelAxolotl *ax)
1449 while (NULL != ax->skipped_head)
1450 delete_skipped_key (ax,
1452 GNUNET_assert (0 == ax->skipped);
1453 GNUNET_free_non_null (ax->kx_0);
1454 GNUNET_free_non_null (ax->DHRs);
1459 * Update our Axolotl key state based on the KX data we received.
1460 * Computes the new chain keys, and root keys, etc, and also checks
1461 * wether this is a replay of the current chain.
1463 * @param[in|out] axolotl chain key state to recompute
1464 * @param pid peer identity of the other peer
1465 * @param ephemeral_key ephemeral public key of the other peer
1466 * @param ratchet_key senders next ephemeral public key
1467 * @return #GNUNET_OK on success, #GNUNET_NO if the resulting
1468 * root key is already in @a ax and thus the KX is useless;
1469 * #GNUNET_SYSERR on hard errors (i.e. @a pid is #my_full_id)
1472 update_ax_by_kx (struct CadetTunnelAxolotl *ax,
1473 const struct GNUNET_PeerIdentity *pid,
1474 const struct GNUNET_CRYPTO_EcdhePublicKey *ephemeral_key,
1475 const struct GNUNET_CRYPTO_EcdhePublicKey *ratchet_key)
1477 struct GNUNET_HashCode key_material[3];
1478 struct GNUNET_CRYPTO_SymmetricSessionKey keys[5];
1479 const char salt[] = "CADET Axolotl salt";
1482 if (0 > GNUNET_CRYPTO_cmp_peer_identity (&my_full_id,
1484 am_I_alice = GNUNET_YES;
1485 else if (0 < GNUNET_CRYPTO_cmp_peer_identity (&my_full_id,
1487 am_I_alice = GNUNET_NO;
1490 GNUNET_break_op (0);
1491 return GNUNET_SYSERR;
1494 if (0 == memcmp (&ax->DHRr,
1496 sizeof (*ratchet_key)))
1498 LOG (GNUNET_ERROR_TYPE_DEBUG,
1499 "Ratchet key already known. Ignoring KX.\n");
1503 ax->DHRr = *ratchet_key;
1506 if (GNUNET_YES == am_I_alice)
1508 GNUNET_CRYPTO_eddsa_ecdh (my_private_key, /* A */
1509 ephemeral_key, /* B0 */
1514 GNUNET_CRYPTO_ecdh_eddsa (ax->kx_0, /* B0 */
1515 &pid->public_key, /* A */
1520 if (GNUNET_YES == am_I_alice)
1522 GNUNET_CRYPTO_ecdh_eddsa (ax->kx_0, /* A0 */
1523 &pid->public_key, /* B */
1528 GNUNET_CRYPTO_eddsa_ecdh (my_private_key, /* A */
1529 ephemeral_key, /* B0 */
1536 /* (This is the triple-DH, we could probably safely skip this,
1537 as A0/B0 are already in the key material.) */
1538 GNUNET_CRYPTO_ecc_ecdh (ax->kx_0, /* A0 or B0 */
1539 ephemeral_key, /* B0 or A0 */
1543 GNUNET_CRYPTO_kdf (keys, sizeof (keys),
1544 salt, sizeof (salt),
1545 &key_material, sizeof (key_material),
1548 if (0 == memcmp (&ax->RK,
1552 LOG (GNUNET_ERROR_TYPE_DEBUG,
1553 "Root key of handshake already known. Ignoring KX.\n");
1558 if (GNUNET_YES == am_I_alice)
1564 ax->ratchet_flag = GNUNET_YES;
1572 ax->ratchet_flag = GNUNET_NO;
1573 ax->ratchet_expiration
1574 = GNUNET_TIME_absolute_add (GNUNET_TIME_absolute_get(),
1582 * Try to redo the KX or KX_AUTH handshake, if we can.
1584 * @param cls the `struct CadetTunnel` to do KX for.
1587 retry_kx (void *cls)
1589 struct CadetTunnel *t = cls;
1590 struct CadetTunnelAxolotl *ax;
1593 LOG (GNUNET_ERROR_TYPE_DEBUG,
1594 "Trying to make KX progress on %s in state %s\n",
1596 estate2s (t->estate));
1599 case CADET_TUNNEL_KEY_UNINITIALIZED: /* first attempt */
1600 case CADET_TUNNEL_KEY_AX_SENT: /* trying again */
1605 case CADET_TUNNEL_KEY_AX_RECV:
1606 case CADET_TUNNEL_KEY_AX_SENT_AND_RECV:
1607 /* We are responding, so only require reply
1608 if WE have a channel waiting. */
1609 if (NULL != t->unverified_ax)
1611 /* Send AX_AUTH so we might get this one verified */
1612 ax = t->unverified_ax;
1616 /* How can this be? */
1623 (0 == GCT_count_channels (t))
1627 case CADET_TUNNEL_KEY_AX_AUTH_SENT:
1628 /* We are responding, so only require reply
1629 if WE have a channel waiting. */
1630 if (NULL != t->unverified_ax)
1632 /* Send AX_AUTH so we might get this one verified */
1633 ax = t->unverified_ax;
1637 /* How can this be? */
1644 (0 == GCT_count_channels (t))
1648 case CADET_TUNNEL_KEY_OK:
1649 /* Must have been the *other* peer asking us to
1650 respond with a KX_AUTH. */
1651 if (NULL != t->unverified_ax)
1653 /* Sending AX_AUTH in response to AX so we might get this one verified */
1654 ax = t->unverified_ax;
1658 /* Sending AX_AUTH in response to AX_AUTH */
1671 * Handle KX message that lacks authentication (and which will thus
1672 * only be considered authenticated after we respond with our own
1673 * KX_AUTH and finally successfully decrypt payload).
1675 * @param ct connection/tunnel combo that received encrypted message
1676 * @param msg the key exchange message
1679 GCT_handle_kx (struct CadetTConnection *ct,
1680 const struct GNUNET_CADET_TunnelKeyExchangeMessage *msg)
1682 struct CadetTunnel *t = ct->t;
1683 struct CadetTunnelAxolotl *ax;
1687 memcmp (&t->ax.DHRr,
1689 sizeof (msg->ratchet_key)))
1691 LOG (GNUNET_ERROR_TYPE_DEBUG,
1692 "Got duplicate KX. Firing back KX_AUTH.\n");
1700 /* We only keep ONE unverified KX around, so if there is an existing one,
1702 if (NULL != t->unverified_ax)
1705 memcmp (&t->unverified_ax->DHRr,
1707 sizeof (msg->ratchet_key)))
1709 LOG (GNUNET_ERROR_TYPE_DEBUG,
1710 "Got duplicate unverified KX on %s. Fire back KX_AUTH again.\n",
1718 LOG (GNUNET_ERROR_TYPE_DEBUG,
1719 "Dropping old unverified KX state. Got a fresh KX for %s.\n",
1721 memset (t->unverified_ax,
1723 sizeof (struct CadetTunnelAxolotl));
1724 t->unverified_ax->DHRs = t->ax.DHRs;
1725 t->unverified_ax->kx_0 = t->ax.kx_0;
1729 LOG (GNUNET_ERROR_TYPE_DEBUG,
1730 "Creating fresh unverified KX for %s.\n",
1732 t->unverified_ax = GNUNET_new (struct CadetTunnelAxolotl);
1733 t->unverified_ax->DHRs = t->ax.DHRs;
1734 t->unverified_ax->kx_0 = t->ax.kx_0;
1736 /* Set as the 'current' RK/DHRr the one we are currently using,
1737 so that the duplicate-detection logic of
1738 #update_ax_by_kx can work. */
1739 t->unverified_ax->RK = t->ax.RK;
1740 t->unverified_ax->DHRr = t->ax.DHRr;
1741 t->unverified_attempts = 0;
1742 ax = t->unverified_ax;
1744 /* Update 'ax' by the new key material */
1745 ret = update_ax_by_kx (ax,
1746 GCP_get_id (t->destination),
1747 &msg->ephemeral_key,
1749 GNUNET_break (GNUNET_SYSERR != ret);
1750 if (GNUNET_OK != ret)
1751 return; /* duplicate KX, nothing to do */
1753 /* move ahead in our state machine */
1754 if (CADET_TUNNEL_KEY_UNINITIALIZED == t->estate)
1755 GCT_change_estate (t,
1756 CADET_TUNNEL_KEY_AX_RECV);
1757 else if (CADET_TUNNEL_KEY_AX_SENT == t->estate)
1758 GCT_change_estate (t,
1759 CADET_TUNNEL_KEY_AX_SENT_AND_RECV);
1761 /* KX is still not done, try again our end. */
1762 if (CADET_TUNNEL_KEY_OK != t->estate)
1764 if (NULL != t->kx_task)
1765 GNUNET_SCHEDULER_cancel (t->kx_task);
1767 = GNUNET_SCHEDULER_add_now (&retry_kx,
1774 * Handle KX_AUTH message.
1776 * @param ct connection/tunnel combo that received encrypted message
1777 * @param msg the key exchange message
1780 GCT_handle_kx_auth (struct CadetTConnection *ct,
1781 const struct GNUNET_CADET_TunnelKeyExchangeAuthMessage *msg)
1783 struct CadetTunnel *t = ct->t;
1784 struct CadetTunnelAxolotl ax_tmp;
1785 struct GNUNET_HashCode kx_auth;
1788 if ( (CADET_TUNNEL_KEY_UNINITIALIZED == t->estate) ||
1789 (CADET_TUNNEL_KEY_AX_RECV == t->estate) )
1791 /* Confusing, we got a KX_AUTH before we even send our own
1792 KX. This should not happen. We'll send our own KX ASAP anyway,
1793 so let's ignore this here. */
1794 GNUNET_break_op (0);
1797 LOG (GNUNET_ERROR_TYPE_DEBUG,
1798 "Handling KX_AUTH message for %s\n",
1801 /* We do everything in ax_tmp until we've checked the authentication
1802 so we don't clobber anything we care about by accident. */
1805 /* Update 'ax' by the new key material */
1806 ret = update_ax_by_kx (&ax_tmp,
1807 GCP_get_id (t->destination),
1808 &msg->kx.ephemeral_key,
1809 &msg->kx.ratchet_key);
1810 GNUNET_break (GNUNET_OK == ret);
1811 GNUNET_CRYPTO_hash (&ax_tmp.RK,
1814 if (0 != memcmp (&kx_auth,
1818 /* This KX_AUTH is not using the latest KX/KX_AUTH data
1819 we transmitted to the sender, refuse it! */
1820 GNUNET_break_op (0);
1823 /* Yep, we're good. */
1825 if (NULL != t->unverified_ax)
1827 /* We got some "stale" KX before, drop that. */
1828 t->unverified_ax->DHRs = NULL; /* aliased with ax.DHRs */
1829 t->unverified_ax->kx_0 = NULL; /* aliased with ax.DHRs */
1830 cleanup_ax (t->unverified_ax);
1831 GNUNET_free (t->unverified_ax);
1832 t->unverified_ax = NULL;
1835 /* move ahead in our state machine */
1838 case CADET_TUNNEL_KEY_UNINITIALIZED:
1839 case CADET_TUNNEL_KEY_AX_RECV:
1840 /* Checked above, this is impossible. */
1843 case CADET_TUNNEL_KEY_AX_SENT: /* This is the normal case */
1844 case CADET_TUNNEL_KEY_AX_SENT_AND_RECV: /* both peers started KX */
1845 case CADET_TUNNEL_KEY_AX_AUTH_SENT: /* both peers now did KX_AUTH */
1846 GCT_change_estate (t,
1847 CADET_TUNNEL_KEY_OK);
1849 case CADET_TUNNEL_KEY_OK:
1850 /* Did not expect another KX_AUTH, but so what, still acceptable.
1851 Nothing to do here. */
1858 /* ************************************** end core crypto ***************************** */
1862 * Compute the next free channel tunnel number for this tunnel.
1864 * @param t the tunnel
1865 * @return unused number that can uniquely identify a channel in the tunnel
1867 static struct GNUNET_CADET_ChannelTunnelNumber
1868 get_next_free_ctn (struct CadetTunnel *t)
1870 #define HIGH_BIT 0x8000000
1871 struct GNUNET_CADET_ChannelTunnelNumber ret;
1876 cmp = GNUNET_CRYPTO_cmp_peer_identity (&my_full_id,
1877 GCP_get_id (GCT_get_destination (t)));
1883 GNUNET_assert (0); // loopback must never go here!
1884 ctn = ntohl (t->next_ctn.cn);
1886 GNUNET_CONTAINER_multihashmap32_get (t->channels,
1889 ctn = ((ctn + 1) & (~ HIGH_BIT)) | highbit;
1891 t->next_ctn.cn = htonl (((ctn + 1) & (~ HIGH_BIT)) | highbit);
1892 ret.cn = ntohl (ctn);
1898 * Add a channel to a tunnel, and notify channel that we are ready
1899 * for transmission if we are already up. Otherwise that notification
1900 * will be done later in #notify_tunnel_up_cb().
1904 * @return unique number identifying @a ch within @a t
1906 struct GNUNET_CADET_ChannelTunnelNumber
1907 GCT_add_channel (struct CadetTunnel *t,
1908 struct CadetChannel *ch)
1910 struct GNUNET_CADET_ChannelTunnelNumber ctn;
1912 ctn = get_next_free_ctn (t);
1913 GNUNET_assert (GNUNET_YES ==
1914 GNUNET_CONTAINER_multihashmap32_put (t->channels,
1917 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY));
1918 LOG (GNUNET_ERROR_TYPE_DEBUG,
1919 "Adding %s to %s\n",
1924 case CADET_TUNNEL_KEY_UNINITIALIZED:
1925 /* waiting for connection to start KX */
1927 case CADET_TUNNEL_KEY_AX_RECV:
1928 case CADET_TUNNEL_KEY_AX_SENT:
1929 case CADET_TUNNEL_KEY_AX_SENT_AND_RECV:
1930 /* we're currently waiting for KX to complete */
1932 case CADET_TUNNEL_KEY_AX_AUTH_SENT:
1933 /* waiting for OTHER peer to send us data,
1934 we might need to prompt more aggressively! */
1935 if (NULL == t->kx_task)
1937 = GNUNET_SCHEDULER_add_at (t->next_kx_attempt,
1941 case CADET_TUNNEL_KEY_OK:
1942 /* We are ready. Tell the new channel that we are up. */
1943 GCCH_tunnel_up (ch);
1951 * We lost a connection, remove it from our list and clean up
1952 * the connection object itself.
1954 * @param ct binding of connection to tunnel of the connection that was lost.
1957 GCT_connection_lost (struct CadetTConnection *ct)
1959 struct CadetTunnel *t = ct->t;
1961 if (GNUNET_YES == ct->is_ready)
1962 GNUNET_CONTAINER_DLL_remove (t->connection_ready_head,
1963 t->connection_ready_tail,
1966 GNUNET_CONTAINER_DLL_remove (t->connection_busy_head,
1967 t->connection_busy_tail,
1974 * Clean up connection @a ct of a tunnel.
1976 * @param cls the `struct CadetTunnel`
1977 * @param ct connection to clean up
1980 destroy_t_connection (void *cls,
1981 struct CadetTConnection *ct)
1983 struct CadetTunnel *t = cls;
1984 struct CadetConnection *cc = ct->cc;
1986 GNUNET_assert (ct->t == t);
1987 GCT_connection_lost (ct);
1988 GCC_destroy_without_tunnel (cc);
1993 * This tunnel is no longer used, destroy it.
1995 * @param cls the idle tunnel
1998 destroy_tunnel (void *cls)
2000 struct CadetTunnel *t = cls;
2001 struct CadetTunnelQueueEntry *tq;
2003 t->destroy_task = NULL;
2004 LOG (GNUNET_ERROR_TYPE_DEBUG,
2005 "Destroying idle %s\n",
2007 GNUNET_assert (0 == GCT_count_channels (t));
2008 GCT_iterate_connections (t,
2009 &destroy_t_connection,
2011 GNUNET_assert (NULL == t->connection_ready_head);
2012 GNUNET_assert (NULL == t->connection_busy_head);
2013 while (NULL != (tq = t->tq_head))
2015 if (NULL != tq->cont)
2016 tq->cont (tq->cont_cls,
2018 GCT_send_cancel (tq);
2020 GCP_drop_tunnel (t->destination,
2022 GNUNET_CONTAINER_multihashmap32_destroy (t->channels);
2023 if (NULL != t->maintain_connections_task)
2025 GNUNET_SCHEDULER_cancel (t->maintain_connections_task);
2026 t->maintain_connections_task = NULL;
2028 if (NULL != t->send_task)
2030 GNUNET_SCHEDULER_cancel (t->send_task);
2031 t->send_task = NULL;
2033 if (NULL != t->kx_task)
2035 GNUNET_SCHEDULER_cancel (t->kx_task);
2038 GNUNET_MST_destroy (t->mst);
2039 GNUNET_MQ_destroy (t->mq);
2040 if (NULL != t->unverified_ax)
2042 t->unverified_ax->DHRs = NULL; /* aliased with ax.DHRs */
2043 t->unverified_ax->kx_0 = NULL; /* aliased with ax.DHRs */
2044 cleanup_ax (t->unverified_ax);
2045 GNUNET_free (t->unverified_ax);
2047 cleanup_ax (&t->ax);
2048 GNUNET_assert (NULL == t->destroy_task);
2054 * Remove a channel from a tunnel.
2058 * @param ctn unique number identifying @a ch within @a t
2061 GCT_remove_channel (struct CadetTunnel *t,
2062 struct CadetChannel *ch,
2063 struct GNUNET_CADET_ChannelTunnelNumber ctn)
2065 LOG (GNUNET_ERROR_TYPE_DEBUG,
2066 "Removing %s from %s\n",
2069 GNUNET_assert (GNUNET_YES ==
2070 GNUNET_CONTAINER_multihashmap32_remove (t->channels,
2074 GCT_count_channels (t)) &&
2075 (NULL == t->destroy_task) )
2078 = GNUNET_SCHEDULER_add_delayed (IDLE_DESTROY_DELAY,
2086 * Destroy remaining channels during shutdown.
2088 * @param cls the `struct CadetTunnel` of the channel
2089 * @param key key of the channel
2090 * @param value the `struct CadetChannel`
2091 * @return #GNUNET_OK (continue to iterate)
2094 destroy_remaining_channels (void *cls,
2098 struct CadetChannel *ch = value;
2100 GCCH_handle_remote_destroy (ch,
2107 * Destroys the tunnel @a t now, without delay. Used during shutdown.
2109 * @param t tunnel to destroy
2112 GCT_destroy_tunnel_now (struct CadetTunnel *t)
2114 GNUNET_assert (GNUNET_YES == shutting_down);
2115 GNUNET_CONTAINER_multihashmap32_iterate (t->channels,
2116 &destroy_remaining_channels,
2119 GCT_count_channels (t));
2120 if (NULL != t->destroy_task)
2122 GNUNET_SCHEDULER_cancel (t->destroy_task);
2123 t->destroy_task = NULL;
2130 * Send normal payload from queue in @a t via connection @a ct.
2131 * Does nothing if our payload queue is empty.
2133 * @param t tunnel to send data from
2134 * @param ct connection to use for transmission (is ready)
2137 try_send_normal_payload (struct CadetTunnel *t,
2138 struct CadetTConnection *ct)
2140 struct CadetTunnelQueueEntry *tq;
2142 GNUNET_assert (GNUNET_YES == ct->is_ready);
2146 /* no messages pending right now */
2147 LOG (GNUNET_ERROR_TYPE_DEBUG,
2148 "Not sending payload of %s on ready %s (nothing pending)\n",
2153 /* ready to send message 'tq' on tunnel 'ct' */
2154 GNUNET_assert (t == tq->t);
2155 GNUNET_CONTAINER_DLL_remove (t->tq_head,
2158 if (NULL != tq->cid)
2159 *tq->cid = *GCC_get_id (ct->cc);
2160 mark_connection_unready (ct);
2161 LOG (GNUNET_ERROR_TYPE_DEBUG,
2162 "Sending payload of %s on %s\n",
2165 GCC_transmit (ct->cc,
2167 if (NULL != tq->cont)
2168 tq->cont (tq->cont_cls,
2169 GCC_get_id (ct->cc));
2175 * A connection is @a is_ready for transmission. Looks at our message
2176 * queue and if there is a message, sends it out via the connection.
2178 * @param cls the `struct CadetTConnection` that is @a is_ready
2179 * @param is_ready #GNUNET_YES if connection are now ready,
2180 * #GNUNET_NO if connection are no longer ready
2183 connection_ready_cb (void *cls,
2186 struct CadetTConnection *ct = cls;
2187 struct CadetTunnel *t = ct->t;
2189 if (GNUNET_NO == is_ready)
2191 LOG (GNUNET_ERROR_TYPE_DEBUG,
2192 "%s no longer ready for %s\n",
2195 mark_connection_unready (ct);
2198 GNUNET_assert (GNUNET_NO == ct->is_ready);
2199 GNUNET_CONTAINER_DLL_remove (t->connection_busy_head,
2200 t->connection_busy_tail,
2202 GNUNET_assert (0 < t->num_busy_connections);
2203 t->num_busy_connections--;
2204 ct->is_ready = GNUNET_YES;
2205 GNUNET_CONTAINER_DLL_insert_tail (t->connection_ready_head,
2206 t->connection_ready_tail,
2208 t->num_ready_connections++;
2210 LOG (GNUNET_ERROR_TYPE_DEBUG,
2211 "%s now ready for %s in state %s\n",
2214 estate2s (t->estate));
2217 case CADET_TUNNEL_KEY_UNINITIALIZED:
2218 /* Do not begin KX if WE have no channels waiting! */
2219 if (0 == GCT_count_channels (t))
2221 /* We are uninitialized, just transmit immediately,
2222 without undue delay. */
2223 if (NULL != t->kx_task)
2225 GNUNET_SCHEDULER_cancel (t->kx_task);
2232 case CADET_TUNNEL_KEY_AX_RECV:
2233 case CADET_TUNNEL_KEY_AX_SENT:
2234 case CADET_TUNNEL_KEY_AX_SENT_AND_RECV:
2235 case CADET_TUNNEL_KEY_AX_AUTH_SENT:
2236 /* we're currently waiting for KX to complete, schedule job */
2237 if (NULL == t->kx_task)
2239 = GNUNET_SCHEDULER_add_at (t->next_kx_attempt,
2243 case CADET_TUNNEL_KEY_OK:
2244 if (GNUNET_YES == t->kx_auth_requested)
2246 if (NULL != t->kx_task)
2248 GNUNET_SCHEDULER_cancel (t->kx_task);
2257 try_send_normal_payload (t,
2265 * Called when either we have a new connection, or a new message in the
2266 * queue, or some existing connection has transmission capacity. Looks
2267 * at our message queue and if there is a message, picks a connection
2270 * @param cls the `struct CadetTunnel` to process messages on
2273 trigger_transmissions (void *cls)
2275 struct CadetTunnel *t = cls;
2276 struct CadetTConnection *ct;
2278 t->send_task = NULL;
2279 if (NULL == t->tq_head)
2280 return; /* no messages pending right now */
2281 ct = get_ready_connection (t);
2283 return; /* no connections ready */
2284 try_send_normal_payload (t,
2290 * Closure for #evaluate_connection. Used to assemble summary information
2291 * about the existing connections so we can evaluate a new path.
2293 struct EvaluationSummary
2297 * Minimum length of any of our connections, `UINT_MAX` if we have none.
2299 unsigned int min_length;
2302 * Maximum length of any of our connections, 0 if we have none.
2304 unsigned int max_length;
2307 * Minimum desirability of any of our connections, UINT64_MAX if we have none.
2309 GNUNET_CONTAINER_HeapCostType min_desire;
2312 * Maximum desirability of any of our connections, 0 if we have none.
2314 GNUNET_CONTAINER_HeapCostType max_desire;
2317 * Path we are comparing against for #evaluate_connection, can be NULL.
2319 struct CadetPeerPath *path;
2322 * Connection deemed the "worst" so far encountered by #evaluate_connection,
2323 * NULL if we did not yet encounter any connections.
2325 struct CadetTConnection *worst;
2328 * Numeric score of @e worst, only set if @e worst is non-NULL.
2333 * Set to #GNUNET_YES if we have a connection over @e path already.
2341 * Evaluate a connection, updating our summary information in @a cls about
2342 * what kinds of connections we have.
2344 * @param cls the `struct EvaluationSummary *` to update
2345 * @param ct a connection to include in the summary
2348 evaluate_connection (void *cls,
2349 struct CadetTConnection *ct)
2351 struct EvaluationSummary *es = cls;
2352 struct CadetConnection *cc = ct->cc;
2353 struct CadetPeerPath *ps = GCC_get_path (cc);
2354 GNUNET_CONTAINER_HeapCostType ct_desirability;
2360 LOG (GNUNET_ERROR_TYPE_DEBUG,
2361 "Ignoring duplicate path %s.\n",
2362 GCPP_2s (es->path));
2363 es->duplicate = GNUNET_YES;
2366 ct_desirability = GCPP_get_desirability (ps);
2367 ct_length = GCPP_get_length (ps);
2369 /* FIXME: calculate score on more than path,
2370 include connection performance metrics like
2371 last successful transmission, uptime, etc. */
2372 score = ct_desirability + ct_length; /* FIXME: weigh these as well! */
2374 if ( (NULL == es->worst) ||
2375 (score < es->worst_score) )
2378 es->worst_score = score;
2380 es->min_length = GNUNET_MIN (es->min_length,
2382 es->max_length = GNUNET_MAX (es->max_length,
2384 es->min_desire = GNUNET_MIN (es->min_desire,
2386 es->max_desire = GNUNET_MAX (es->max_desire,
2392 * Consider using the path @a p for the tunnel @a t.
2393 * The tunnel destination is at offset @a off in path @a p.
2395 * @param cls our tunnel
2396 * @param path a path to our destination
2397 * @param off offset of the destination on path @a path
2398 * @return #GNUNET_YES (should keep iterating)
2401 consider_path_cb (void *cls,
2402 struct CadetPeerPath *path,
2405 struct CadetTunnel *t = cls;
2406 struct EvaluationSummary es;
2407 struct CadetTConnection *ct;
2409 es.min_length = UINT_MAX;
2412 es.min_desire = UINT64_MAX;
2414 es.duplicate = GNUNET_NO;
2416 /* Compute evaluation summary over existing connections. */
2417 GCT_iterate_connections (t,
2418 &evaluate_connection,
2420 if (GNUNET_YES == es.duplicate)
2423 /* FIXME: not sure we should really just count
2424 'num_connections' here, as they may all have
2425 consistently failed to connect. */
2427 /* We iterate by increasing path length; if we have enough paths and
2428 this one is more than twice as long than what we are currently
2429 using, then ignore all of these super-long ones! */
2430 if ( (GCT_count_any_connections (t) > DESIRED_CONNECTIONS_PER_TUNNEL) &&
2431 (es.min_length * 2 < off) &&
2432 (es.max_length < off) )
2434 LOG (GNUNET_ERROR_TYPE_DEBUG,
2435 "Ignoring paths of length %u, they are way too long.\n",
2439 /* If we have enough paths and this one looks no better, ignore it. */
2440 if ( (GCT_count_any_connections (t) >= DESIRED_CONNECTIONS_PER_TUNNEL) &&
2441 (es.min_length < GCPP_get_length (path)) &&
2442 (es.min_desire > GCPP_get_desirability (path)) &&
2443 (es.max_length < off) )
2445 LOG (GNUNET_ERROR_TYPE_DEBUG,
2446 "Ignoring path (%u/%llu) to %s, got something better already.\n",
2447 GCPP_get_length (path),
2448 (unsigned long long) GCPP_get_desirability (path),
2449 GCP_2s (t->destination));
2453 /* Path is interesting (better by some metric, or we don't have
2454 enough paths yet). */
2455 ct = GNUNET_new (struct CadetTConnection);
2456 ct->created = GNUNET_TIME_absolute_get ();
2458 ct->cc = GCC_create (t->destination,
2460 GNUNET_CADET_OPTION_DEFAULT, /* FIXME: set based on what channels want/need! */
2462 &connection_ready_cb,
2465 /* FIXME: schedule job to kill connection (and path?) if it takes
2466 too long to get ready! (And track performance data on how long
2467 other connections took with the tunnel!)
2468 => Note: to be done within 'connection'-logic! */
2469 GNUNET_CONTAINER_DLL_insert (t->connection_busy_head,
2470 t->connection_busy_tail,
2472 t->num_busy_connections++;
2473 LOG (GNUNET_ERROR_TYPE_DEBUG,
2474 "Found interesting path %s for %s, created %s\n",
2483 * Function called to maintain the connections underlying our tunnel.
2484 * Tries to maintain (incl. tear down) connections for the tunnel, and
2485 * if there is a significant change, may trigger transmissions.
2487 * Basically, needs to check if there are connections that perform
2488 * badly, and if so eventually kill them and trigger a replacement.
2489 * The strategy is to open one more connection than
2490 * #DESIRED_CONNECTIONS_PER_TUNNEL, and then periodically kick out the
2491 * least-performing one, and then inquire for new ones.
2493 * @param cls the `struct CadetTunnel`
2496 maintain_connections_cb (void *cls)
2498 struct CadetTunnel *t = cls;
2499 struct GNUNET_TIME_Relative delay;
2500 struct EvaluationSummary es;
2502 t->maintain_connections_task = NULL;
2503 LOG (GNUNET_ERROR_TYPE_DEBUG,
2504 "Performing connection maintenance for %s.\n",
2507 es.min_length = UINT_MAX;
2510 es.min_desire = UINT64_MAX;
2513 es.duplicate = GNUNET_NO;
2514 GCT_iterate_connections (t,
2515 &evaluate_connection,
2517 if ( (NULL != es.worst) &&
2518 (GCT_count_any_connections (t) > DESIRED_CONNECTIONS_PER_TUNNEL) )
2520 /* Clear out worst-performing connection 'es.worst'. */
2521 destroy_t_connection (t,
2525 /* Consider additional paths */
2526 (void) GCP_iterate_paths (t->destination,
2530 /* FIXME: calculate when to try again based on how well we are doing;
2531 in particular, if we have to few connections, we might be able
2532 to do without this (as PATHS should tell us whenever a new path
2533 is available instantly; however, need to make sure this job is
2534 restarted after that happens).
2535 Furthermore, if the paths we do know are in a reasonably narrow
2536 quality band and are plentyful, we might also consider us stabilized
2537 and then reduce the frequency accordingly. */
2538 delay = GNUNET_TIME_UNIT_MINUTES;
2539 t->maintain_connections_task
2540 = GNUNET_SCHEDULER_add_delayed (delay,
2541 &maintain_connections_cb,
2547 * Consider using the path @a p for the tunnel @a t.
2548 * The tunnel destination is at offset @a off in path @a p.
2550 * @param cls our tunnel
2551 * @param path a path to our destination
2552 * @param off offset of the destination on path @a path
2555 GCT_consider_path (struct CadetTunnel *t,
2556 struct CadetPeerPath *p,
2559 (void) consider_path_cb (t,
2566 * We got a keepalive. Track in statistics.
2568 * @param cls the `struct CadetTunnel` for which we decrypted the message
2569 * @param msg the message we received on the tunnel
2572 handle_plaintext_keepalive (void *cls,
2573 const struct GNUNET_MessageHeader *msg)
2575 struct CadetTunnel *t = cls;
2577 LOG (GNUNET_ERROR_TYPE_DEBUG,
2578 "Received KEEPALIVE on %s\n",
2580 GNUNET_STATISTICS_update (stats,
2581 "# keepalives received",
2588 * Check that @a msg is well-formed.
2590 * @param cls the `struct CadetTunnel` for which we decrypted the message
2591 * @param msg the message we received on the tunnel
2592 * @return #GNUNET_OK (any variable-size payload goes)
2595 check_plaintext_data (void *cls,
2596 const struct GNUNET_CADET_ChannelAppDataMessage *msg)
2603 * We received payload data for a channel. Locate the channel
2604 * and process the data, or return an error if the channel is unknown.
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_data (void *cls,
2611 const struct GNUNET_CADET_ChannelAppDataMessage *msg)
2613 struct CadetTunnel *t = cls;
2614 struct CadetChannel *ch;
2616 ch = lookup_channel (t,
2620 /* We don't know about such a channel, might have been destroyed on our
2621 end in the meantime, or never existed. Send back a DESTROY. */
2622 LOG (GNUNET_ERROR_TYPE_DEBUG,
2623 "Receicved %u bytes of application data for unknown channel %u, sending DESTROY\n",
2624 (unsigned int) (ntohs (msg->header.size) - sizeof (*msg)),
2625 ntohl (msg->ctn.cn));
2626 GCT_send_channel_destroy (t,
2630 GCCH_handle_channel_plaintext_data (ch,
2631 GCC_get_id (t->current_ct->cc),
2637 * We received an acknowledgement for data we sent on a channel.
2638 * Locate the channel and process it, or return an error if the
2639 * channel is unknown.
2641 * @param cls the `struct CadetTunnel` for which we decrypted the message
2642 * @param ack the message we received on the tunnel
2645 handle_plaintext_data_ack (void *cls,
2646 const struct GNUNET_CADET_ChannelDataAckMessage *ack)
2648 struct CadetTunnel *t = cls;
2649 struct CadetChannel *ch;
2651 ch = lookup_channel (t,
2655 /* We don't know about such a channel, might have been destroyed on our
2656 end in the meantime, or never existed. Send back a DESTROY. */
2657 LOG (GNUNET_ERROR_TYPE_DEBUG,
2658 "Receicved DATA_ACK for unknown channel %u, sending DESTROY\n",
2659 ntohl (ack->ctn.cn));
2660 GCT_send_channel_destroy (t,
2664 GCCH_handle_channel_plaintext_data_ack (ch,
2665 GCC_get_id (t->current_ct->cc),
2671 * We have received a request to open a channel to a port from
2672 * another peer. Creates the incoming channel.
2674 * @param cls the `struct CadetTunnel` for which we decrypted the message
2675 * @param copen the message we received on the tunnel
2678 handle_plaintext_channel_open (void *cls,
2679 const struct GNUNET_CADET_ChannelOpenMessage *copen)
2681 struct CadetTunnel *t = cls;
2682 struct CadetChannel *ch;
2684 ch = GNUNET_CONTAINER_multihashmap32_get (t->channels,
2685 ntohl (copen->ctn.cn));
2688 LOG (GNUNET_ERROR_TYPE_DEBUG,
2689 "Receicved duplicate channel OPEN on port %s from %s (%s), resending ACK\n",
2690 GNUNET_h2s (&copen->port),
2693 GCCH_handle_duplicate_open (ch,
2694 GCC_get_id (t->current_ct->cc));
2697 LOG (GNUNET_ERROR_TYPE_DEBUG,
2698 "Receicved channel OPEN on port %s from %s\n",
2699 GNUNET_h2s (&copen->port),
2701 ch = GCCH_channel_incoming_new (t,
2704 ntohl (copen->opt));
2705 GNUNET_assert (GNUNET_OK ==
2706 GNUNET_CONTAINER_multihashmap32_put (t->channels,
2707 ntohl (copen->ctn.cn),
2709 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY));
2714 * Send a DESTROY message via the tunnel.
2716 * @param t the tunnel to transmit over
2717 * @param ctn ID of the channel to destroy
2720 GCT_send_channel_destroy (struct CadetTunnel *t,
2721 struct GNUNET_CADET_ChannelTunnelNumber ctn)
2723 struct GNUNET_CADET_ChannelManageMessage msg;
2725 LOG (GNUNET_ERROR_TYPE_DEBUG,
2726 "Sending DESTORY message for channel ID %u\n",
2728 msg.header.size = htons (sizeof (msg));
2729 msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_CHANNEL_DESTROY);
2730 msg.reserved = htonl (0);
2740 * We have received confirmation from the target peer that the
2741 * given channel could be established (the port is open).
2744 * @param cls the `struct CadetTunnel` for which we decrypted the message
2745 * @param cm the message we received on the tunnel
2748 handle_plaintext_channel_open_ack (void *cls,
2749 const struct GNUNET_CADET_ChannelManageMessage *cm)
2751 struct CadetTunnel *t = cls;
2752 struct CadetChannel *ch;
2754 ch = lookup_channel (t,
2758 /* We don't know about such a channel, might have been destroyed on our
2759 end in the meantime, or never existed. Send back a DESTROY. */
2760 LOG (GNUNET_ERROR_TYPE_DEBUG,
2761 "Received channel OPEN_ACK for unknown channel %u, sending DESTROY\n",
2762 ntohl (cm->ctn.cn));
2763 GCT_send_channel_destroy (t,
2767 LOG (GNUNET_ERROR_TYPE_DEBUG,
2768 "Received channel OPEN_ACK on channel %s from %s\n",
2771 GCCH_handle_channel_open_ack (ch,
2772 GCC_get_id (t->current_ct->cc));
2777 * We received a message saying that a channel should be destroyed.
2778 * Pass it on to the correct channel.
2780 * @param cls the `struct CadetTunnel` for which we decrypted the message
2781 * @param cm the message we received on the tunnel
2784 handle_plaintext_channel_destroy (void *cls,
2785 const struct GNUNET_CADET_ChannelManageMessage *cm)
2787 struct CadetTunnel *t = cls;
2788 struct CadetChannel *ch;
2790 ch = lookup_channel (t,
2794 /* We don't know about such a channel, might have been destroyed on our
2795 end in the meantime, or never existed. */
2796 LOG (GNUNET_ERROR_TYPE_DEBUG,
2797 "Received channel DESTORY for unknown channel %u. Ignoring.\n",
2798 ntohl (cm->ctn.cn));
2801 LOG (GNUNET_ERROR_TYPE_DEBUG,
2802 "Receicved channel DESTROY on %s from %s\n",
2805 GCCH_handle_remote_destroy (ch,
2806 GCC_get_id (t->current_ct->cc));
2811 * Handles a message we decrypted, by injecting it into
2812 * our message queue (which will do the dispatching).
2814 * @param cls the `struct CadetTunnel` that got the message
2815 * @param msg the message
2816 * @return #GNUNET_OK (continue to process)
2819 handle_decrypted (void *cls,
2820 const struct GNUNET_MessageHeader *msg)
2822 struct CadetTunnel *t = cls;
2824 GNUNET_assert (NULL != t->current_ct);
2825 GNUNET_MQ_inject_message (t->mq,
2832 * Function called if we had an error processing
2833 * an incoming decrypted message.
2835 * @param cls the `struct CadetTunnel`
2836 * @param error error code
2839 decrypted_error_cb (void *cls,
2840 enum GNUNET_MQ_Error error)
2842 GNUNET_break_op (0);
2847 * Create a tunnel to @a destionation. Must only be called
2848 * from within #GCP_get_tunnel().
2850 * @param destination where to create the tunnel to
2851 * @return new tunnel to @a destination
2853 struct CadetTunnel *
2854 GCT_create_tunnel (struct CadetPeer *destination)
2856 struct CadetTunnel *t = GNUNET_new (struct CadetTunnel);
2857 struct GNUNET_MQ_MessageHandler handlers[] = {
2858 GNUNET_MQ_hd_fixed_size (plaintext_keepalive,
2859 GNUNET_MESSAGE_TYPE_CADET_CHANNEL_KEEPALIVE,
2860 struct GNUNET_MessageHeader,
2862 GNUNET_MQ_hd_var_size (plaintext_data,
2863 GNUNET_MESSAGE_TYPE_CADET_CHANNEL_APP_DATA,
2864 struct GNUNET_CADET_ChannelAppDataMessage,
2866 GNUNET_MQ_hd_fixed_size (plaintext_data_ack,
2867 GNUNET_MESSAGE_TYPE_CADET_CHANNEL_APP_DATA_ACK,
2868 struct GNUNET_CADET_ChannelDataAckMessage,
2870 GNUNET_MQ_hd_fixed_size (plaintext_channel_open,
2871 GNUNET_MESSAGE_TYPE_CADET_CHANNEL_OPEN,
2872 struct GNUNET_CADET_ChannelOpenMessage,
2874 GNUNET_MQ_hd_fixed_size (plaintext_channel_open_ack,
2875 GNUNET_MESSAGE_TYPE_CADET_CHANNEL_OPEN_ACK,
2876 struct GNUNET_CADET_ChannelManageMessage,
2878 GNUNET_MQ_hd_fixed_size (plaintext_channel_destroy,
2879 GNUNET_MESSAGE_TYPE_CADET_CHANNEL_DESTROY,
2880 struct GNUNET_CADET_ChannelManageMessage,
2882 GNUNET_MQ_handler_end ()
2885 t->kx_retry_delay = INITIAL_KX_RETRY_DELAY;
2886 new_ephemeral (&t->ax);
2887 t->ax.kx_0 = GNUNET_CRYPTO_ecdhe_key_create ();
2888 t->destination = destination;
2889 t->channels = GNUNET_CONTAINER_multihashmap32_create (8);
2890 t->maintain_connections_task
2891 = GNUNET_SCHEDULER_add_now (&maintain_connections_cb,
2893 t->mq = GNUNET_MQ_queue_for_callbacks (NULL,
2898 &decrypted_error_cb,
2900 t->mst = GNUNET_MST_create (&handle_decrypted,
2907 * Add a @a connection to the @a tunnel.
2910 * @param cid connection identifer to use for the connection
2911 * @param options options for the connection
2912 * @param path path to use for the connection
2913 * @return #GNUNET_OK on success,
2914 * #GNUNET_SYSERR on failure (duplicate connection)
2917 GCT_add_inbound_connection (struct CadetTunnel *t,
2918 const struct GNUNET_CADET_ConnectionTunnelIdentifier *cid,
2919 enum GNUNET_CADET_ChannelOption options,
2920 struct CadetPeerPath *path)
2922 struct CadetTConnection *ct;
2924 ct = GNUNET_new (struct CadetTConnection);
2925 ct->created = GNUNET_TIME_absolute_get ();
2927 ct->cc = GCC_create_inbound (t->destination,
2932 &connection_ready_cb,
2936 LOG (GNUNET_ERROR_TYPE_DEBUG,
2937 "%s refused inbound %s (duplicate)\n",
2941 return GNUNET_SYSERR;
2943 /* FIXME: schedule job to kill connection (and path?) if it takes
2944 too long to get ready! (And track performance data on how long
2945 other connections took with the tunnel!)
2946 => Note: to be done within 'connection'-logic! */
2947 GNUNET_CONTAINER_DLL_insert (t->connection_busy_head,
2948 t->connection_busy_tail,
2950 t->num_busy_connections++;
2951 LOG (GNUNET_ERROR_TYPE_DEBUG,
2960 * Handle encrypted message.
2962 * @param ct connection/tunnel combo that received encrypted message
2963 * @param msg the encrypted message to decrypt
2966 GCT_handle_encrypted (struct CadetTConnection *ct,
2967 const struct GNUNET_CADET_TunnelEncryptedMessage *msg)
2969 struct CadetTunnel *t = ct->t;
2970 uint16_t size = ntohs (msg->header.size);
2971 char cbuf [size] GNUNET_ALIGN;
2972 ssize_t decrypted_size;
2974 LOG (GNUNET_ERROR_TYPE_DEBUG,
2975 "%s received %u bytes of encrypted data in state %d\n",
2977 (unsigned int) size,
2982 case CADET_TUNNEL_KEY_UNINITIALIZED:
2983 case CADET_TUNNEL_KEY_AX_RECV:
2984 /* We did not even SEND our KX, how can the other peer
2985 send us encrypted data? */
2986 GNUNET_break_op (0);
2988 case CADET_TUNNEL_KEY_AX_SENT_AND_RECV:
2989 /* We send KX, and other peer send KX to us at the same time.
2990 Neither KX is AUTH'ed, so let's try KX_AUTH this time. */
2991 GNUNET_STATISTICS_update (stats,
2992 "# received encrypted without KX_AUTH",
2995 if (NULL != t->kx_task)
2997 GNUNET_SCHEDULER_cancel (t->kx_task);
3005 case CADET_TUNNEL_KEY_AX_SENT:
3006 /* We did not get the KX of the other peer, but that
3007 might have been lost. Send our KX again immediately. */
3008 GNUNET_STATISTICS_update (stats,
3009 "# received encrypted without KX",
3012 if (NULL != t->kx_task)
3014 GNUNET_SCHEDULER_cancel (t->kx_task);
3021 case CADET_TUNNEL_KEY_AX_AUTH_SENT:
3022 /* Great, first payload, we might graduate to OK! */
3023 case CADET_TUNNEL_KEY_OK:
3024 /* We are up and running, all good. */
3028 GNUNET_STATISTICS_update (stats,
3029 "# received encrypted",
3032 decrypted_size = -1;
3033 if (CADET_TUNNEL_KEY_OK == t->estate)
3035 /* We have well-established key material available,
3036 try that. (This is the common case.) */
3037 decrypted_size = t_ax_decrypt_and_validate (&t->ax,
3043 if ( (-1 == decrypted_size) &&
3044 (NULL != t->unverified_ax) )
3046 /* We have un-authenticated KX material available. We should try
3047 this as a back-up option, in case the sender crashed and
3049 decrypted_size = t_ax_decrypt_and_validate (t->unverified_ax,
3053 if (-1 != decrypted_size)
3055 /* It worked! Treat this as authentication of the AX data! */
3056 t->ax.DHRs = NULL; /* aliased with ax.DHRs */
3057 t->ax.kx_0 = NULL; /* aliased with ax.DHRs */
3058 cleanup_ax (&t->ax);
3059 t->ax = *t->unverified_ax;
3060 GNUNET_free (t->unverified_ax);
3061 t->unverified_ax = NULL;
3063 if (CADET_TUNNEL_KEY_AX_AUTH_SENT == t->estate)
3065 /* First time it worked, move tunnel into production! */
3066 GCT_change_estate (t,
3067 CADET_TUNNEL_KEY_OK);
3068 if (NULL != t->send_task)
3069 GNUNET_SCHEDULER_cancel (t->send_task);
3070 t->send_task = GNUNET_SCHEDULER_add_now (&trigger_transmissions,
3074 if (NULL != t->unverified_ax)
3076 /* We had unverified KX material that was useless; so increment
3077 counter and eventually move to ignore it. Note that we even do
3078 this increment if we successfully decrypted with the old KX
3079 material and thus didn't even both with the new one. This is
3080 the ideal case, as a malicious injection of bogus KX data
3081 basically only causes us to increment a counter a few times. */
3082 t->unverified_attempts++;
3083 LOG (GNUNET_ERROR_TYPE_DEBUG,
3084 "Failed to decrypt message with unverified KX data %u times\n",
3085 t->unverified_attempts);
3086 if (t->unverified_attempts > MAX_UNVERIFIED_ATTEMPTS)
3088 t->unverified_ax->DHRs = NULL; /* aliased with ax.DHRs */
3089 t->unverified_ax->kx_0 = NULL; /* aliased with ax.DHRs */
3090 cleanup_ax (t->unverified_ax);
3091 GNUNET_free (t->unverified_ax);
3092 t->unverified_ax = NULL;
3096 if (-1 == decrypted_size)
3098 /* Decryption failed for good, complain. */
3099 GNUNET_break_op (0);
3100 LOG (GNUNET_ERROR_TYPE_WARNING,
3101 "%s failed to decrypt and validate encrypted data\n",
3103 GNUNET_STATISTICS_update (stats,
3104 "# unable to decrypt",
3110 /* The MST will ultimately call #handle_decrypted() on each message. */
3112 GNUNET_break_op (GNUNET_OK ==
3113 GNUNET_MST_from_buffer (t->mst,
3118 t->current_ct = NULL;
3123 * Sends an already built message on a tunnel, encrypting it and
3124 * choosing the best connection if not provided.
3126 * @param message Message to send. Function modifies it.
3127 * @param t Tunnel on which this message is transmitted.
3128 * @param cont Continuation to call once message is really sent.
3129 * @param cont_cls Closure for @c cont.
3130 * @return Handle to cancel message
3132 struct CadetTunnelQueueEntry *
3133 GCT_send (struct CadetTunnel *t,
3134 const struct GNUNET_MessageHeader *message,
3135 GCT_SendContinuation cont,
3138 struct CadetTunnelQueueEntry *tq;
3139 uint16_t payload_size;
3140 struct GNUNET_MQ_Envelope *env;
3141 struct GNUNET_CADET_TunnelEncryptedMessage *ax_msg;
3143 if (CADET_TUNNEL_KEY_OK != t->estate)
3148 payload_size = ntohs (message->size);
3149 LOG (GNUNET_ERROR_TYPE_DEBUG,
3150 "Encrypting %u bytes for %s\n",
3151 (unsigned int) payload_size,
3153 env = GNUNET_MQ_msg_extra (ax_msg,
3155 GNUNET_MESSAGE_TYPE_CADET_TUNNEL_ENCRYPTED);
3156 t_ax_encrypt (&t->ax,
3160 ax_msg->ax_header.Ns = htonl (t->ax.Ns++);
3161 ax_msg->ax_header.PNs = htonl (t->ax.PNs);
3162 /* FIXME: we should do this once, not once per message;
3163 this is a point multiplication, and DHRs does not
3164 change all the time. */
3165 GNUNET_CRYPTO_ecdhe_key_get_public (t->ax.DHRs,
3166 &ax_msg->ax_header.DHRs);
3167 t_h_encrypt (&t->ax,
3169 t_hmac (&ax_msg->ax_header,
3170 sizeof (struct GNUNET_CADET_AxHeader) + payload_size,
3175 tq = GNUNET_malloc (sizeof (*tq));
3178 tq->cid = &ax_msg->cid; /* will initialize 'ax_msg->cid' once we know the connection */
3180 tq->cont_cls = cont_cls;
3181 GNUNET_CONTAINER_DLL_insert_tail (t->tq_head,
3184 if (NULL != t->send_task)
3185 GNUNET_SCHEDULER_cancel (t->send_task);
3187 = GNUNET_SCHEDULER_add_now (&trigger_transmissions,
3194 * Cancel a previously sent message while it's in the queue.
3196 * ONLY can be called before the continuation given to the send
3197 * function is called. Once the continuation is called, the message is
3198 * no longer in the queue!
3200 * @param tq Handle to the queue entry to cancel.
3203 GCT_send_cancel (struct CadetTunnelQueueEntry *tq)
3205 struct CadetTunnel *t = tq->t;
3207 GNUNET_CONTAINER_DLL_remove (t->tq_head,
3210 GNUNET_MQ_discard (tq->env);
3216 * Iterate over all connections of a tunnel.
3218 * @param t Tunnel whose connections to iterate.
3219 * @param iter Iterator.
3220 * @param iter_cls Closure for @c iter.
3223 GCT_iterate_connections (struct CadetTunnel *t,
3224 GCT_ConnectionIterator iter,
3227 struct CadetTConnection *n;
3228 for (struct CadetTConnection *ct = t->connection_ready_head;
3236 for (struct CadetTConnection *ct = t->connection_busy_head;
3248 * Closure for #iterate_channels_cb.
3255 GCT_ChannelIterator iter;
3258 * Closure for @e iter.
3265 * Helper function for #GCT_iterate_channels.
3267 * @param cls the `struct ChanIterCls`
3269 * @param value a `struct CadetChannel`
3270 * @return #GNUNET_OK
3273 iterate_channels_cb (void *cls,
3277 struct ChanIterCls *ctx = cls;
3278 struct CadetChannel *ch = value;
3280 ctx->iter (ctx->iter_cls,
3287 * Iterate over all channels of a tunnel.
3289 * @param t Tunnel whose channels to iterate.
3290 * @param iter Iterator.
3291 * @param iter_cls Closure for @c iter.
3294 GCT_iterate_channels (struct CadetTunnel *t,
3295 GCT_ChannelIterator iter,
3298 struct ChanIterCls ctx;
3301 ctx.iter_cls = iter_cls;
3302 GNUNET_CONTAINER_multihashmap32_iterate (t->channels,
3303 &iterate_channels_cb,
3310 * Call #GCCH_debug() on a channel.
3312 * @param cls points to the log level to use
3314 * @param value the `struct CadetChannel` to dump
3315 * @return #GNUNET_OK (continue iteration)
3318 debug_channel (void *cls,
3322 const enum GNUNET_ErrorType *level = cls;
3323 struct CadetChannel *ch = value;
3325 GCCH_debug (ch, *level);
3330 #define LOG2(level, ...) GNUNET_log_from_nocheck(level,"cadet-tun",__VA_ARGS__)
3334 * Log all possible info about the tunnel state.
3336 * @param t Tunnel to debug.
3337 * @param level Debug level to use.
3340 GCT_debug (const struct CadetTunnel *t,
3341 enum GNUNET_ErrorType level)
3343 struct CadetTConnection *iter_c;
3346 do_log = GNUNET_get_log_call_status (level & (~GNUNET_ERROR_TYPE_BULK),
3348 __FILE__, __FUNCTION__, __LINE__);
3353 "TTT TUNNEL TOWARDS %s in estate %s tq_len: %u #cons: %u\n",
3355 estate2s (t->estate),
3357 GCT_count_any_connections (t));
3360 GNUNET_CONTAINER_multihashmap32_iterate (t->channels,
3364 "TTT connections:\n");
3365 for (iter_c = t->connection_ready_head; NULL != iter_c; iter_c = iter_c->next)
3366 GCC_debug (iter_c->cc,
3368 for (iter_c = t->connection_busy_head; NULL != iter_c; iter_c = iter_c->next)
3369 GCC_debug (iter_c->cc,
3373 "TTT TUNNEL END\n");
3377 /* end of gnunet-service-cadet-new_tunnels.c */