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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 * + 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). Note that for the
177 * 'unverified_ax', this member is an alias with the main
178 * 't->ax.kx_0' value, so do not free it!
180 struct GNUNET_CRYPTO_EcdhePrivateKey *kx_0;
183 * ECDH Ratchet key (our private key in the current DH). Note that
184 * for the 'unverified_ax', this member is an alias with the main
185 * 't->ax.kx_0' value, so do not free it!
187 struct GNUNET_CRYPTO_EcdhePrivateKey *DHRs;
190 * ECDH Ratchet key (other peer's public key in the current DH).
192 struct GNUNET_CRYPTO_EcdhePublicKey DHRr;
195 * Time when the current ratchet expires and a new one is triggered
196 * (if @e ratchet_allowed is #GNUNET_YES).
198 struct GNUNET_TIME_Absolute ratchet_expiration;
201 * Number of elements in @a skipped_head <-> @a skipped_tail.
203 unsigned int skipped;
206 * Message number (reset to 0 with each new ratchet, next message to send).
211 * Message number (reset to 0 with each new ratchet, next message to recv).
216 * Previous message numbers (# of msgs sent under prev ratchet)
221 * True (#GNUNET_YES) if we have to send a new ratchet key in next msg.
226 * True (#GNUNET_YES) if we have received a message from the
227 * other peer that uses the keys from our last ratchet step.
228 * This implies that we are again allowed to advance the ratchet,
229 * otherwise we have to wait until the other peer sees our current
230 * ephemeral key and advances first.
232 * #GNUNET_NO if we have advanced the ratched but lack any evidence
233 * that the other peer has noticed this.
238 * Number of messages recieved since our last ratchet advance.
240 * If this counter = 0, we cannot send a new ratchet key in the next
243 * If this counter > 0, we could (but don't have to) send a new key.
245 * Once the @e ratchet_counter is larger than
246 * #ratchet_messages (or @e ratchet_expiration time has past), and
247 * @e ratchet_allowed is #GNUNET_YES, we advance the ratchet.
249 unsigned int ratchet_counter;
255 * Struct used to save messages in a non-ready tunnel to send once connected.
257 struct CadetTunnelQueueEntry
260 * We are entries in a DLL
262 struct CadetTunnelQueueEntry *next;
265 * We are entries in a DLL
267 struct CadetTunnelQueueEntry *prev;
270 * Tunnel these messages belong in.
272 struct CadetTunnel *t;
275 * Continuation to call once sent (on the channel layer).
277 GCT_SendContinuation cont;
280 * Closure for @c cont.
285 * Envelope of message to send follows.
287 struct GNUNET_MQ_Envelope *env;
290 * Where to put the connection identifier into the payload
291 * of the message in @e env once we have it?
293 struct GNUNET_CADET_ConnectionTunnelIdentifier *cid;
298 * Struct containing all information regarding a tunnel to a peer.
303 * Destination of the tunnel.
305 struct CadetPeer *destination;
308 * Peer's ephemeral key, to recreate @c e_key and @c d_key when own
309 * ephemeral key changes.
311 struct GNUNET_CRYPTO_EcdhePublicKey peers_ephemeral_key;
314 * Encryption ("our") key. It is only "confirmed" if kx_ctx is NULL.
316 struct GNUNET_CRYPTO_SymmetricSessionKey e_key;
319 * Decryption ("their") key. It is only "confirmed" if kx_ctx is NULL.
321 struct GNUNET_CRYPTO_SymmetricSessionKey d_key;
326 struct CadetTunnelAxolotl ax;
329 * Unverified Axolotl info, used only if we got a fresh KX (not a
330 * KX_AUTH) while our end of the tunnel was still up. In this case,
331 * we keep the fresh KX around but do not put it into action until
332 * we got encrypted payload that assures us of the authenticity of
335 struct CadetTunnelAxolotl *unverified_ax;
338 * Task scheduled if there are no more channels using the tunnel.
340 struct GNUNET_SCHEDULER_Task *destroy_task;
343 * Task to trim connections if too many are present.
345 struct GNUNET_SCHEDULER_Task *maintain_connections_task;
348 * Task to send messages from queue (if possible).
350 struct GNUNET_SCHEDULER_Task *send_task;
353 * Task to trigger KX.
355 struct GNUNET_SCHEDULER_Task *kx_task;
358 * Tokenizer for decrypted messages.
360 struct GNUNET_MessageStreamTokenizer *mst;
363 * Dispatcher for decrypted messages only (do NOT use for sending!).
365 struct GNUNET_MQ_Handle *mq;
368 * DLL of ready connections that are actively used to reach the destination peer.
370 struct CadetTConnection *connection_ready_head;
373 * DLL of ready connections that are actively used to reach the destination peer.
375 struct CadetTConnection *connection_ready_tail;
378 * DLL of connections that we maintain that might be used to reach the destination peer.
380 struct CadetTConnection *connection_busy_head;
383 * DLL of connections that we maintain that might be used to reach the destination peer.
385 struct CadetTConnection *connection_busy_tail;
388 * Channels inside this tunnel. Maps
389 * `struct GNUNET_CADET_ChannelTunnelNumber` to a `struct CadetChannel`.
391 struct GNUNET_CONTAINER_MultiHashMap32 *channels;
394 * Channel ID for the next created channel in this tunnel.
396 struct GNUNET_CADET_ChannelTunnelNumber next_ctn;
399 * Queued messages, to transmit once tunnel gets connected.
401 struct CadetTunnelQueueEntry *tq_head;
404 * Queued messages, to transmit once tunnel gets connected.
406 struct CadetTunnelQueueEntry *tq_tail;
409 * Identification of the connection from which we are currently processing
410 * a message. Only valid (non-NULL) during #handle_decrypted() and the
411 * handle-*()-functions called from our @e mq during that function.
413 struct CadetTConnection *current_ct;
416 * How long do we wait until we retry the KX?
418 struct GNUNET_TIME_Relative kx_retry_delay;
421 * When do we try the next KX?
423 struct GNUNET_TIME_Absolute next_kx_attempt;
426 * Number of connections in the @e connection_ready_head DLL.
428 unsigned int num_ready_connections;
431 * Number of connections in the @e connection_busy_head DLL.
433 unsigned int num_busy_connections;
436 * How often have we tried and failed to decrypt a message using
437 * the unverified KX material from @e unverified_ax? Used to
438 * stop trying after #MAX_UNVERIFIED_ATTEMPTS.
440 unsigned int unverified_attempts;
443 * Number of entries in the @e tq_head DLL.
448 * State of the tunnel encryption.
450 enum CadetTunnelEState estate;
453 * Force triggering KX_AUTH independent of @e estate.
455 int kx_auth_requested;
461 * Connection @a ct is now unready, clear it's ready flag
462 * and move it from the ready DLL to the busy DLL.
464 * @param ct connection to move to unready status
467 mark_connection_unready (struct CadetTConnection *ct)
469 struct CadetTunnel *t = ct->t;
471 GNUNET_assert (GNUNET_YES == ct->is_ready);
472 GNUNET_CONTAINER_DLL_remove (t->connection_ready_head,
473 t->connection_ready_tail,
475 GNUNET_assert (0 < t->num_ready_connections);
476 t->num_ready_connections--;
477 ct->is_ready = GNUNET_NO;
478 GNUNET_CONTAINER_DLL_insert (t->connection_busy_head,
479 t->connection_busy_tail,
481 t->num_busy_connections++;
486 * Get the static string for the peer this tunnel is directed.
490 * @return Static string the destination peer's ID.
493 GCT_2s (const struct CadetTunnel *t)
498 return "Tunnel(NULL)";
499 GNUNET_snprintf (buf,
502 GNUNET_i2s (GCP_get_id (t->destination)));
508 * Get string description for tunnel encryption state.
510 * @param es Tunnel state.
512 * @return String representation.
515 estate2s (enum CadetTunnelEState es)
521 case CADET_TUNNEL_KEY_UNINITIALIZED:
522 return "CADET_TUNNEL_KEY_UNINITIALIZED";
523 case CADET_TUNNEL_KEY_AX_RECV:
524 return "CADET_TUNNEL_KEY_AX_RECV";
525 case CADET_TUNNEL_KEY_AX_SENT:
526 return "CADET_TUNNEL_KEY_AX_SENT";
527 case CADET_TUNNEL_KEY_AX_SENT_AND_RECV:
528 return "CADET_TUNNEL_KEY_AX_SENT_AND_RECV";
529 case CADET_TUNNEL_KEY_AX_AUTH_SENT:
530 return "CADET_TUNNEL_KEY_AX_AUTH_SENT";
531 case CADET_TUNNEL_KEY_OK:
532 return "CADET_TUNNEL_KEY_OK";
534 GNUNET_snprintf (buf,
536 "%u (UNKNOWN STATE)",
544 * Return the peer to which this tunnel goes.
547 * @return the destination of the tunnel
550 GCT_get_destination (struct CadetTunnel *t)
552 return t->destination;
557 * Count channels of a tunnel.
559 * @param t Tunnel on which to count.
561 * @return Number of channels.
564 GCT_count_channels (struct CadetTunnel *t)
566 return GNUNET_CONTAINER_multihashmap32_size (t->channels);
571 * Lookup a channel by its @a ctn.
573 * @param t tunnel to look in
574 * @param ctn number of channel to find
575 * @return NULL if channel does not exist
577 struct CadetChannel *
578 lookup_channel (struct CadetTunnel *t,
579 struct GNUNET_CADET_ChannelTunnelNumber ctn)
581 return GNUNET_CONTAINER_multihashmap32_get (t->channels,
587 * Count all created connections of a tunnel. Not necessarily ready connections!
589 * @param t Tunnel on which to count.
591 * @return Number of connections created, either being established or ready.
594 GCT_count_any_connections (const struct CadetTunnel *t)
596 return t->num_ready_connections + t->num_busy_connections;
601 * Find first connection that is ready in the list of
602 * our connections. Picks ready connections round-robin.
604 * @param t tunnel to search
605 * @return NULL if we have no connection that is ready
607 static struct CadetTConnection *
608 get_ready_connection (struct CadetTunnel *t)
610 return t->connection_ready_head;
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 GNUNET_free_non_null (ax->DHRs);
652 LOG (GNUNET_ERROR_TYPE_DEBUG,
653 "Creating new ephemeral ratchet key (DHRs)\n");
654 ax->DHRs = GNUNET_CRYPTO_ecdhe_key_create ();
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;
1323 ct = get_ready_connection (t);
1326 LOG (GNUNET_ERROR_TYPE_DEBUG,
1327 "Wanted to send %s in state %s, but no connection is ready, deferring\n",
1329 estate2s (t->estate));
1330 t->next_kx_attempt = GNUNET_TIME_absolute_get ();
1334 LOG (GNUNET_ERROR_TYPE_DEBUG,
1335 "Sending KX on %s via %s using %s in state %s\n",
1338 estate2s (t->estate));
1339 env = GNUNET_MQ_msg (msg,
1340 GNUNET_MESSAGE_TYPE_CADET_TUNNEL_KX);
1341 flags = GNUNET_CADET_KX_FLAG_FORCE_REPLY; /* always for KX */
1342 msg->flags = htonl (flags);
1343 msg->cid = *GCC_get_id (cc);
1344 GNUNET_CRYPTO_ecdhe_key_get_public (ax->kx_0,
1345 &msg->ephemeral_key);
1346 GNUNET_CRYPTO_ecdhe_key_get_public (ax->DHRs,
1348 mark_connection_unready (ct);
1349 t->kx_retry_delay = GNUNET_TIME_STD_BACKOFF (t->kx_retry_delay);
1350 t->next_kx_attempt = GNUNET_TIME_relative_to_absolute (t->kx_retry_delay);
1351 if (CADET_TUNNEL_KEY_UNINITIALIZED == t->estate)
1352 GCT_change_estate (t,
1353 CADET_TUNNEL_KEY_AX_SENT);
1354 else if (CADET_TUNNEL_KEY_AX_RECV == t->estate)
1355 GCT_change_estate (t,
1356 CADET_TUNNEL_KEY_AX_SENT_AND_RECV);
1363 * Send a KX_AUTH message.
1365 * @param t tunnel on which to send the KX_AUTH
1366 * @param ct Tunnel and connection on which to send the KX_AUTH, NULL if
1367 * we are to find one that is ready.
1368 * @param ax axolotl key context to use
1369 * @param force_reply Force the other peer to reply with a KX_AUTH message
1370 * (set if we would like to transmit right now, but cannot)
1373 send_kx_auth (struct CadetTunnel *t,
1374 struct CadetTConnection *ct,
1375 struct CadetTunnelAxolotl *ax,
1378 struct CadetConnection *cc;
1379 struct GNUNET_MQ_Envelope *env;
1380 struct GNUNET_CADET_TunnelKeyExchangeAuthMessage *msg;
1381 enum GNUNET_CADET_KX_Flags flags;
1383 if ( (NULL == ct) ||
1384 (GNUNET_NO == ct->is_ready) )
1385 ct = get_ready_connection (t);
1388 LOG (GNUNET_ERROR_TYPE_DEBUG,
1389 "Wanted to send KX_AUTH on %s, but no connection is ready, deferring\n",
1391 t->next_kx_attempt = GNUNET_TIME_absolute_get ();
1392 t->kx_auth_requested = GNUNET_YES; /* queue KX_AUTH independent of estate */
1395 t->kx_auth_requested = GNUNET_NO; /* clear flag */
1397 LOG (GNUNET_ERROR_TYPE_DEBUG,
1398 "Sending KX_AUTH on %s using %s\n",
1402 env = GNUNET_MQ_msg (msg,
1403 GNUNET_MESSAGE_TYPE_CADET_TUNNEL_KX_AUTH);
1404 flags = GNUNET_CADET_KX_FLAG_NONE;
1405 if (GNUNET_YES == force_reply)
1406 flags |= GNUNET_CADET_KX_FLAG_FORCE_REPLY;
1407 msg->kx.flags = htonl (flags);
1408 msg->kx.cid = *GCC_get_id (cc);
1409 GNUNET_CRYPTO_ecdhe_key_get_public (ax->kx_0,
1410 &msg->kx.ephemeral_key);
1411 GNUNET_CRYPTO_ecdhe_key_get_public (ax->DHRs,
1412 &msg->kx.ratchet_key);
1413 /* Compute authenticator (this is the main difference to #send_kx()) */
1414 GNUNET_CRYPTO_hash (&ax->RK,
1418 /* Compute when to be triggered again; actual job will
1419 be scheduled via #connection_ready_cb() */
1421 = GNUNET_TIME_STD_BACKOFF (t->kx_retry_delay);
1423 = GNUNET_TIME_relative_to_absolute (t->kx_retry_delay);
1425 /* Send via cc, mark it as unready */
1426 mark_connection_unready (ct);
1428 /* Update state machine, unless we are already OK */
1429 if (CADET_TUNNEL_KEY_OK != t->estate)
1430 GCT_change_estate (t,
1431 CADET_TUNNEL_KEY_AX_AUTH_SENT);
1439 * Cleanup state used by @a ax.
1441 * @param ax state to free, but not memory of @a ax itself
1444 cleanup_ax (struct CadetTunnelAxolotl *ax)
1446 while (NULL != ax->skipped_head)
1447 delete_skipped_key (ax,
1449 GNUNET_assert (0 == ax->skipped);
1450 GNUNET_free_non_null (ax->kx_0);
1451 GNUNET_free_non_null (ax->DHRs);
1456 * Update our Axolotl key state based on the KX data we received.
1457 * Computes the new chain keys, and root keys, etc, and also checks
1458 * wether this is a replay of the current chain.
1460 * @param[in|out] axolotl chain key state to recompute
1461 * @param pid peer identity of the other peer
1462 * @param ephemeral_key ephemeral public key of the other peer
1463 * @param ratchet_key senders next ephemeral public key
1464 * @return #GNUNET_OK on success, #GNUNET_NO if the resulting
1465 * root key is already in @a ax and thus the KX is useless;
1466 * #GNUNET_SYSERR on hard errors (i.e. @a pid is #my_full_id)
1469 update_ax_by_kx (struct CadetTunnelAxolotl *ax,
1470 const struct GNUNET_PeerIdentity *pid,
1471 const struct GNUNET_CRYPTO_EcdhePublicKey *ephemeral_key,
1472 const struct GNUNET_CRYPTO_EcdhePublicKey *ratchet_key)
1474 struct GNUNET_HashCode key_material[3];
1475 struct GNUNET_CRYPTO_SymmetricSessionKey keys[5];
1476 const char salt[] = "CADET Axolotl salt";
1479 if (0 > GNUNET_CRYPTO_cmp_peer_identity (&my_full_id,
1481 am_I_alice = GNUNET_YES;
1482 else if (0 < GNUNET_CRYPTO_cmp_peer_identity (&my_full_id,
1484 am_I_alice = GNUNET_NO;
1487 GNUNET_break_op (0);
1488 return GNUNET_SYSERR;
1491 if (0 == memcmp (&ax->DHRr,
1493 sizeof (*ratchet_key)))
1495 LOG (GNUNET_ERROR_TYPE_DEBUG,
1496 "Ratchet key already known. Ignoring KX.\n");
1500 ax->DHRr = *ratchet_key;
1503 if (GNUNET_YES == am_I_alice)
1505 GNUNET_CRYPTO_eddsa_ecdh (my_private_key, /* A */
1506 ephemeral_key, /* B0 */
1511 GNUNET_CRYPTO_ecdh_eddsa (ax->kx_0, /* B0 */
1512 &pid->public_key, /* A */
1517 if (GNUNET_YES == am_I_alice)
1519 GNUNET_CRYPTO_ecdh_eddsa (ax->kx_0, /* A0 */
1520 &pid->public_key, /* B */
1525 GNUNET_CRYPTO_eddsa_ecdh (my_private_key, /* A */
1526 ephemeral_key, /* B0 */
1533 /* (This is the triple-DH, we could probably safely skip this,
1534 as A0/B0 are already in the key material.) */
1535 GNUNET_CRYPTO_ecc_ecdh (ax->kx_0, /* A0 or B0 */
1536 ephemeral_key, /* B0 or A0 */
1540 GNUNET_CRYPTO_kdf (keys, sizeof (keys),
1541 salt, sizeof (salt),
1542 &key_material, sizeof (key_material),
1545 if (0 == memcmp (&ax->RK,
1549 LOG (GNUNET_ERROR_TYPE_DEBUG,
1550 "Root key of handshake already known. Ignoring KX.\n");
1555 if (GNUNET_YES == am_I_alice)
1561 ax->ratchet_flag = GNUNET_YES;
1569 ax->ratchet_flag = GNUNET_NO;
1570 ax->ratchet_expiration
1571 = GNUNET_TIME_absolute_add (GNUNET_TIME_absolute_get(),
1579 * Try to redo the KX or KX_AUTH handshake, if we can.
1581 * @param cls the `struct CadetTunnel` to do KX for.
1584 retry_kx (void *cls)
1586 struct CadetTunnel *t = cls;
1587 struct CadetTunnelAxolotl *ax;
1590 LOG (GNUNET_ERROR_TYPE_DEBUG,
1591 "Trying to make KX progress on %s in state %s\n",
1593 estate2s (t->estate));
1596 case CADET_TUNNEL_KEY_UNINITIALIZED: /* first attempt */
1597 case CADET_TUNNEL_KEY_AX_SENT: /* trying again */
1602 case CADET_TUNNEL_KEY_AX_RECV:
1603 case CADET_TUNNEL_KEY_AX_SENT_AND_RECV:
1604 /* We are responding, so only require reply
1605 if WE have a channel waiting. */
1606 if (NULL != t->unverified_ax)
1608 /* Send AX_AUTH so we might get this one verified */
1609 ax = t->unverified_ax;
1613 /* How can this be? */
1620 (0 == GCT_count_channels (t))
1624 case CADET_TUNNEL_KEY_AX_AUTH_SENT:
1625 /* We are responding, so only require reply
1626 if WE have a channel waiting. */
1627 if (NULL != t->unverified_ax)
1629 /* Send AX_AUTH so we might get this one verified */
1630 ax = t->unverified_ax;
1634 /* How can this be? */
1641 (0 == GCT_count_channels (t))
1645 case CADET_TUNNEL_KEY_OK:
1646 /* Must have been the *other* peer asking us to
1647 respond with a KX_AUTH. */
1648 if (NULL != t->unverified_ax)
1650 /* Sending AX_AUTH in response to AX so we might get this one verified */
1651 ax = t->unverified_ax;
1655 /* Sending AX_AUTH in response to AX_AUTH */
1668 * Handle KX message that lacks authentication (and which will thus
1669 * only be considered authenticated after we respond with our own
1670 * KX_AUTH and finally successfully decrypt payload).
1672 * @param ct connection/tunnel combo that received encrypted message
1673 * @param msg the key exchange message
1676 GCT_handle_kx (struct CadetTConnection *ct,
1677 const struct GNUNET_CADET_TunnelKeyExchangeMessage *msg)
1679 struct CadetTunnel *t = ct->t;
1680 struct CadetTunnelAxolotl *ax;
1684 memcmp (&t->ax.DHRr,
1686 sizeof (msg->ratchet_key)))
1688 LOG (GNUNET_ERROR_TYPE_DEBUG,
1689 "Got duplicate KX. Firing back KX_AUTH.\n");
1697 /* We only keep ONE unverified KX around, so if there is an existing one,
1699 if (NULL != t->unverified_ax)
1702 memcmp (&t->unverified_ax->DHRr,
1704 sizeof (msg->ratchet_key)))
1706 LOG (GNUNET_ERROR_TYPE_DEBUG,
1707 "Got duplicate unverified KX on %s. Fire back KX_AUTH again.\n",
1715 LOG (GNUNET_ERROR_TYPE_DEBUG,
1716 "Dropping old unverified KX state. Got a fresh KX for %s.\n",
1718 memset (t->unverified_ax,
1720 sizeof (struct CadetTunnelAxolotl));
1721 t->unverified_ax->DHRs = t->ax.DHRs;
1722 t->unverified_ax->kx_0 = t->ax.kx_0;
1726 LOG (GNUNET_ERROR_TYPE_DEBUG,
1727 "Creating fresh unverified KX for %s.\n",
1729 t->unverified_ax = GNUNET_new (struct CadetTunnelAxolotl);
1730 t->unverified_ax->DHRs = t->ax.DHRs;
1731 t->unverified_ax->kx_0 = t->ax.kx_0;
1733 /* Set as the 'current' RK/DHRr the one we are currently using,
1734 so that the duplicate-detection logic of
1735 #update_ax_by_kx can work. */
1736 t->unverified_ax->RK = t->ax.RK;
1737 t->unverified_ax->DHRr = t->ax.DHRr;
1738 t->unverified_attempts = 0;
1739 ax = t->unverified_ax;
1741 /* Update 'ax' by the new key material */
1742 ret = update_ax_by_kx (ax,
1743 GCP_get_id (t->destination),
1744 &msg->ephemeral_key,
1746 GNUNET_break (GNUNET_SYSERR != ret);
1747 if (GNUNET_OK != ret)
1748 return; /* duplicate KX, nothing to do */
1750 /* move ahead in our state machine */
1751 if (CADET_TUNNEL_KEY_UNINITIALIZED == t->estate)
1752 GCT_change_estate (t,
1753 CADET_TUNNEL_KEY_AX_RECV);
1754 else if (CADET_TUNNEL_KEY_AX_SENT == t->estate)
1755 GCT_change_estate (t,
1756 CADET_TUNNEL_KEY_AX_SENT_AND_RECV);
1758 /* KX is still not done, try again our end. */
1759 if (CADET_TUNNEL_KEY_OK != t->estate)
1761 if (NULL != t->kx_task)
1762 GNUNET_SCHEDULER_cancel (t->kx_task);
1764 = GNUNET_SCHEDULER_add_now (&retry_kx,
1771 * Handle KX_AUTH message.
1773 * @param ct connection/tunnel combo that received encrypted message
1774 * @param msg the key exchange message
1777 GCT_handle_kx_auth (struct CadetTConnection *ct,
1778 const struct GNUNET_CADET_TunnelKeyExchangeAuthMessage *msg)
1780 struct CadetTunnel *t = ct->t;
1781 struct CadetTunnelAxolotl ax_tmp;
1782 struct GNUNET_HashCode kx_auth;
1785 if ( (CADET_TUNNEL_KEY_UNINITIALIZED == t->estate) ||
1786 (CADET_TUNNEL_KEY_AX_RECV == t->estate) )
1788 /* Confusing, we got a KX_AUTH before we even send our own
1789 KX. This should not happen. We'll send our own KX ASAP anyway,
1790 so let's ignore this here. */
1791 GNUNET_break_op (0);
1794 LOG (GNUNET_ERROR_TYPE_DEBUG,
1795 "Handling KX_AUTH message for %s\n",
1798 /* We do everything in ax_tmp until we've checked the authentication
1799 so we don't clobber anything we care about by accident. */
1802 /* Update 'ax' by the new key material */
1803 ret = update_ax_by_kx (&ax_tmp,
1804 GCP_get_id (t->destination),
1805 &msg->kx.ephemeral_key,
1806 &msg->kx.ratchet_key);
1807 GNUNET_break (GNUNET_OK == ret);
1808 GNUNET_CRYPTO_hash (&ax_tmp.RK,
1811 if (0 != memcmp (&kx_auth,
1815 /* This KX_AUTH is not using the latest KX/KX_AUTH data
1816 we transmitted to the sender, refuse it, try KX again. */
1817 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 const struct CadetConnectionMetrics *metrics;
2355 GNUNET_CONTAINER_HeapCostType ct_desirability;
2356 struct GNUNET_TIME_Relative uptime;
2357 struct GNUNET_TIME_Relative last_use;
2360 double success_rate;
2364 LOG (GNUNET_ERROR_TYPE_DEBUG,
2365 "Ignoring duplicate path %s.\n",
2366 GCPP_2s (es->path));
2367 es->duplicate = GNUNET_YES;
2370 ct_desirability = GCPP_get_desirability (ps);
2371 ct_length = GCPP_get_length (ps);
2372 metrics = GCC_get_metrics (cc);
2373 uptime = GNUNET_TIME_absolute_get_duration (metrics->age);
2374 last_use = GNUNET_TIME_absolute_get_duration (metrics->last_use);
2375 /* We add 1.0 here to avoid division by zero. */
2376 success_rate = (metrics->num_acked_transmissions + 1.0) / (metrics->num_successes + 1.0);
2379 + 100.0 / (1.0 + ct_length) /* longer paths = better */
2380 + sqrt (uptime.rel_value_us / 60000000LL) /* larger uptime = better */
2381 - last_use.rel_value_us / 1000L; /* longer idle = worse */
2382 score *= success_rate; /* weigh overall by success rate */
2384 if ( (NULL == es->worst) ||
2385 (score < es->worst_score) )
2388 es->worst_score = score;
2390 es->min_length = GNUNET_MIN (es->min_length,
2392 es->max_length = GNUNET_MAX (es->max_length,
2394 es->min_desire = GNUNET_MIN (es->min_desire,
2396 es->max_desire = GNUNET_MAX (es->max_desire,
2402 * Consider using the path @a p for the tunnel @a t.
2403 * The tunnel destination is at offset @a off in path @a p.
2405 * @param cls our tunnel
2406 * @param path a path to our destination
2407 * @param off offset of the destination on path @a path
2408 * @return #GNUNET_YES (should keep iterating)
2411 consider_path_cb (void *cls,
2412 struct CadetPeerPath *path,
2415 struct CadetTunnel *t = cls;
2416 struct EvaluationSummary es;
2417 struct CadetTConnection *ct;
2419 GNUNET_assert (off < GCPP_get_length (path));
2420 es.min_length = UINT_MAX;
2423 es.min_desire = UINT64_MAX;
2425 es.duplicate = GNUNET_NO;
2427 /* Compute evaluation summary over existing connections. */
2428 GCT_iterate_connections (t,
2429 &evaluate_connection,
2431 if (GNUNET_YES == es.duplicate)
2434 /* FIXME: not sure we should really just count
2435 'num_connections' here, as they may all have
2436 consistently failed to connect. */
2438 /* We iterate by increasing path length; if we have enough paths and
2439 this one is more than twice as long than what we are currently
2440 using, then ignore all of these super-long ones! */
2441 if ( (GCT_count_any_connections (t) > DESIRED_CONNECTIONS_PER_TUNNEL) &&
2442 (es.min_length * 2 < off) &&
2443 (es.max_length < off) )
2445 LOG (GNUNET_ERROR_TYPE_DEBUG,
2446 "Ignoring paths of length %u, they are way too long.\n",
2450 /* If we have enough paths and this one looks no better, ignore it. */
2451 if ( (GCT_count_any_connections (t) >= DESIRED_CONNECTIONS_PER_TUNNEL) &&
2452 (es.min_length < GCPP_get_length (path)) &&
2453 (es.min_desire > GCPP_get_desirability (path)) &&
2454 (es.max_length < off) )
2456 LOG (GNUNET_ERROR_TYPE_DEBUG,
2457 "Ignoring path (%u/%llu) to %s, got something better already.\n",
2458 GCPP_get_length (path),
2459 (unsigned long long) GCPP_get_desirability (path),
2460 GCP_2s (t->destination));
2464 /* Path is interesting (better by some metric, or we don't have
2465 enough paths yet). */
2466 ct = GNUNET_new (struct CadetTConnection);
2467 ct->created = GNUNET_TIME_absolute_get ();
2469 ct->cc = GCC_create (t->destination,
2472 GNUNET_CADET_OPTION_DEFAULT, /* FIXME: set based on what channels want/need! */
2474 &connection_ready_cb,
2477 /* FIXME: schedule job to kill connection (and path?) if it takes
2478 too long to get ready! (And track performance data on how long
2479 other connections took with the tunnel!)
2480 => Note: to be done within 'connection'-logic! */
2481 GNUNET_CONTAINER_DLL_insert (t->connection_busy_head,
2482 t->connection_busy_tail,
2484 t->num_busy_connections++;
2485 LOG (GNUNET_ERROR_TYPE_DEBUG,
2486 "Found interesting path %s for %s, created %s\n",
2495 * Function called to maintain the connections underlying our tunnel.
2496 * Tries to maintain (incl. tear down) connections for the tunnel, and
2497 * if there is a significant change, may trigger transmissions.
2499 * Basically, needs to check if there are connections that perform
2500 * badly, and if so eventually kill them and trigger a replacement.
2501 * The strategy is to open one more connection than
2502 * #DESIRED_CONNECTIONS_PER_TUNNEL, and then periodically kick out the
2503 * least-performing one, and then inquire for new ones.
2505 * @param cls the `struct CadetTunnel`
2508 maintain_connections_cb (void *cls)
2510 struct CadetTunnel *t = cls;
2511 struct GNUNET_TIME_Relative delay;
2512 struct EvaluationSummary es;
2514 t->maintain_connections_task = NULL;
2515 LOG (GNUNET_ERROR_TYPE_DEBUG,
2516 "Performing connection maintenance for %s.\n",
2519 es.min_length = UINT_MAX;
2522 es.min_desire = UINT64_MAX;
2525 es.duplicate = GNUNET_NO;
2526 GCT_iterate_connections (t,
2527 &evaluate_connection,
2529 if ( (NULL != es.worst) &&
2530 (GCT_count_any_connections (t) > DESIRED_CONNECTIONS_PER_TUNNEL) )
2532 /* Clear out worst-performing connection 'es.worst'. */
2533 destroy_t_connection (t,
2537 /* Consider additional paths */
2538 (void) GCP_iterate_paths (t->destination,
2542 /* FIXME: calculate when to try again based on how well we are doing;
2543 in particular, if we have to few connections, we might be able
2544 to do without this (as PATHS should tell us whenever a new path
2545 is available instantly; however, need to make sure this job is
2546 restarted after that happens).
2547 Furthermore, if the paths we do know are in a reasonably narrow
2548 quality band and are plentyful, we might also consider us stabilized
2549 and then reduce the frequency accordingly. */
2550 delay = GNUNET_TIME_UNIT_MINUTES;
2551 t->maintain_connections_task
2552 = GNUNET_SCHEDULER_add_delayed (delay,
2553 &maintain_connections_cb,
2559 * Consider using the path @a p for the tunnel @a t.
2560 * The tunnel destination is at offset @a off in path @a p.
2562 * @param cls our tunnel
2563 * @param path a path to our destination
2564 * @param off offset of the destination on path @a path
2567 GCT_consider_path (struct CadetTunnel *t,
2568 struct CadetPeerPath *p,
2571 (void) consider_path_cb (t,
2578 * We got a keepalive. Track in statistics.
2580 * @param cls the `struct CadetTunnel` for which we decrypted the message
2581 * @param msg the message we received on the tunnel
2584 handle_plaintext_keepalive (void *cls,
2585 const struct GNUNET_MessageHeader *msg)
2587 struct CadetTunnel *t = cls;
2589 LOG (GNUNET_ERROR_TYPE_DEBUG,
2590 "Received KEEPALIVE on %s\n",
2592 GNUNET_STATISTICS_update (stats,
2593 "# keepalives received",
2600 * Check that @a msg is well-formed.
2602 * @param cls the `struct CadetTunnel` for which we decrypted the message
2603 * @param msg the message we received on the tunnel
2604 * @return #GNUNET_OK (any variable-size payload goes)
2607 check_plaintext_data (void *cls,
2608 const struct GNUNET_CADET_ChannelAppDataMessage *msg)
2615 * We received payload data for a channel. Locate the channel
2616 * and process the data, or return an error if the channel is unknown.
2618 * @param cls the `struct CadetTunnel` for which we decrypted the message
2619 * @param msg the message we received on the tunnel
2622 handle_plaintext_data (void *cls,
2623 const struct GNUNET_CADET_ChannelAppDataMessage *msg)
2625 struct CadetTunnel *t = cls;
2626 struct CadetChannel *ch;
2628 ch = lookup_channel (t,
2632 /* We don't know about such a channel, might have been destroyed on our
2633 end in the meantime, or never existed. Send back a DESTROY. */
2634 LOG (GNUNET_ERROR_TYPE_DEBUG,
2635 "Receicved %u bytes of application data for unknown channel %u, sending DESTROY\n",
2636 (unsigned int) (ntohs (msg->header.size) - sizeof (*msg)),
2637 ntohl (msg->ctn.cn));
2638 GCT_send_channel_destroy (t,
2642 GCCH_handle_channel_plaintext_data (ch,
2643 GCC_get_id (t->current_ct->cc),
2649 * We received an acknowledgement for data we sent on a channel.
2650 * Locate the channel and process it, or return an error if the
2651 * channel is unknown.
2653 * @param cls the `struct CadetTunnel` for which we decrypted the message
2654 * @param ack the message we received on the tunnel
2657 handle_plaintext_data_ack (void *cls,
2658 const struct GNUNET_CADET_ChannelDataAckMessage *ack)
2660 struct CadetTunnel *t = cls;
2661 struct CadetChannel *ch;
2663 ch = lookup_channel (t,
2667 /* We don't know about such a channel, might have been destroyed on our
2668 end in the meantime, or never existed. Send back a DESTROY. */
2669 LOG (GNUNET_ERROR_TYPE_DEBUG,
2670 "Receicved DATA_ACK for unknown channel %u, sending DESTROY\n",
2671 ntohl (ack->ctn.cn));
2672 GCT_send_channel_destroy (t,
2676 GCCH_handle_channel_plaintext_data_ack (ch,
2677 GCC_get_id (t->current_ct->cc),
2683 * We have received a request to open a channel to a port from
2684 * another peer. Creates the incoming channel.
2686 * @param cls the `struct CadetTunnel` for which we decrypted the message
2687 * @param copen the message we received on the tunnel
2690 handle_plaintext_channel_open (void *cls,
2691 const struct GNUNET_CADET_ChannelOpenMessage *copen)
2693 struct CadetTunnel *t = cls;
2694 struct CadetChannel *ch;
2696 ch = GNUNET_CONTAINER_multihashmap32_get (t->channels,
2697 ntohl (copen->ctn.cn));
2700 LOG (GNUNET_ERROR_TYPE_DEBUG,
2701 "Receicved duplicate channel OPEN on port %s from %s (%s), resending ACK\n",
2702 GNUNET_h2s (&copen->port),
2705 GCCH_handle_duplicate_open (ch,
2706 GCC_get_id (t->current_ct->cc));
2709 LOG (GNUNET_ERROR_TYPE_DEBUG,
2710 "Receicved channel OPEN on port %s from %s\n",
2711 GNUNET_h2s (&copen->port),
2713 ch = GCCH_channel_incoming_new (t,
2716 ntohl (copen->opt));
2717 if (NULL != t->destroy_task)
2719 GNUNET_SCHEDULER_cancel (t->destroy_task);
2720 t->destroy_task = NULL;
2722 GNUNET_assert (GNUNET_OK ==
2723 GNUNET_CONTAINER_multihashmap32_put (t->channels,
2724 ntohl (copen->ctn.cn),
2726 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY));
2731 * Send a DESTROY message via the tunnel.
2733 * @param t the tunnel to transmit over
2734 * @param ctn ID of the channel to destroy
2737 GCT_send_channel_destroy (struct CadetTunnel *t,
2738 struct GNUNET_CADET_ChannelTunnelNumber ctn)
2740 struct GNUNET_CADET_ChannelManageMessage msg;
2742 LOG (GNUNET_ERROR_TYPE_DEBUG,
2743 "Sending DESTORY message for channel ID %u\n",
2745 msg.header.size = htons (sizeof (msg));
2746 msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_CHANNEL_DESTROY);
2747 msg.reserved = htonl (0);
2757 * We have received confirmation from the target peer that the
2758 * given channel could be established (the port is open).
2761 * @param cls the `struct CadetTunnel` for which we decrypted the message
2762 * @param cm the message we received on the tunnel
2765 handle_plaintext_channel_open_ack (void *cls,
2766 const struct GNUNET_CADET_ChannelManageMessage *cm)
2768 struct CadetTunnel *t = cls;
2769 struct CadetChannel *ch;
2771 ch = lookup_channel (t,
2775 /* We don't know about such a channel, might have been destroyed on our
2776 end in the meantime, or never existed. Send back a DESTROY. */
2777 LOG (GNUNET_ERROR_TYPE_DEBUG,
2778 "Received channel OPEN_ACK for unknown channel %u, sending DESTROY\n",
2779 ntohl (cm->ctn.cn));
2780 GCT_send_channel_destroy (t,
2784 LOG (GNUNET_ERROR_TYPE_DEBUG,
2785 "Received channel OPEN_ACK on channel %s from %s\n",
2788 GCCH_handle_channel_open_ack (ch,
2789 GCC_get_id (t->current_ct->cc));
2794 * We received a message saying that a channel should be destroyed.
2795 * Pass it on to the correct channel.
2797 * @param cls the `struct CadetTunnel` for which we decrypted the message
2798 * @param cm the message we received on the tunnel
2801 handle_plaintext_channel_destroy (void *cls,
2802 const struct GNUNET_CADET_ChannelManageMessage *cm)
2804 struct CadetTunnel *t = cls;
2805 struct CadetChannel *ch;
2807 ch = lookup_channel (t,
2811 /* We don't know about such a channel, might have been destroyed on our
2812 end in the meantime, or never existed. */
2813 LOG (GNUNET_ERROR_TYPE_DEBUG,
2814 "Received channel DESTORY for unknown channel %u. Ignoring.\n",
2815 ntohl (cm->ctn.cn));
2818 LOG (GNUNET_ERROR_TYPE_DEBUG,
2819 "Receicved channel DESTROY on %s from %s\n",
2822 GCCH_handle_remote_destroy (ch,
2823 GCC_get_id (t->current_ct->cc));
2828 * Handles a message we decrypted, by injecting it into
2829 * our message queue (which will do the dispatching).
2831 * @param cls the `struct CadetTunnel` that got the message
2832 * @param msg the message
2833 * @return #GNUNET_OK (continue to process)
2836 handle_decrypted (void *cls,
2837 const struct GNUNET_MessageHeader *msg)
2839 struct CadetTunnel *t = cls;
2841 GNUNET_assert (NULL != t->current_ct);
2842 GNUNET_MQ_inject_message (t->mq,
2849 * Function called if we had an error processing
2850 * an incoming decrypted message.
2852 * @param cls the `struct CadetTunnel`
2853 * @param error error code
2856 decrypted_error_cb (void *cls,
2857 enum GNUNET_MQ_Error error)
2859 GNUNET_break_op (0);
2864 * Create a tunnel to @a destionation. Must only be called
2865 * from within #GCP_get_tunnel().
2867 * @param destination where to create the tunnel to
2868 * @return new tunnel to @a destination
2870 struct CadetTunnel *
2871 GCT_create_tunnel (struct CadetPeer *destination)
2873 struct CadetTunnel *t = GNUNET_new (struct CadetTunnel);
2874 struct GNUNET_MQ_MessageHandler handlers[] = {
2875 GNUNET_MQ_hd_fixed_size (plaintext_keepalive,
2876 GNUNET_MESSAGE_TYPE_CADET_CHANNEL_KEEPALIVE,
2877 struct GNUNET_MessageHeader,
2879 GNUNET_MQ_hd_var_size (plaintext_data,
2880 GNUNET_MESSAGE_TYPE_CADET_CHANNEL_APP_DATA,
2881 struct GNUNET_CADET_ChannelAppDataMessage,
2883 GNUNET_MQ_hd_fixed_size (plaintext_data_ack,
2884 GNUNET_MESSAGE_TYPE_CADET_CHANNEL_APP_DATA_ACK,
2885 struct GNUNET_CADET_ChannelDataAckMessage,
2887 GNUNET_MQ_hd_fixed_size (plaintext_channel_open,
2888 GNUNET_MESSAGE_TYPE_CADET_CHANNEL_OPEN,
2889 struct GNUNET_CADET_ChannelOpenMessage,
2891 GNUNET_MQ_hd_fixed_size (plaintext_channel_open_ack,
2892 GNUNET_MESSAGE_TYPE_CADET_CHANNEL_OPEN_ACK,
2893 struct GNUNET_CADET_ChannelManageMessage,
2895 GNUNET_MQ_hd_fixed_size (plaintext_channel_destroy,
2896 GNUNET_MESSAGE_TYPE_CADET_CHANNEL_DESTROY,
2897 struct GNUNET_CADET_ChannelManageMessage,
2899 GNUNET_MQ_handler_end ()
2902 t->kx_retry_delay = INITIAL_KX_RETRY_DELAY;
2903 new_ephemeral (&t->ax);
2904 t->ax.kx_0 = GNUNET_CRYPTO_ecdhe_key_create ();
2905 t->destination = destination;
2906 t->channels = GNUNET_CONTAINER_multihashmap32_create (8);
2907 t->maintain_connections_task
2908 = GNUNET_SCHEDULER_add_now (&maintain_connections_cb,
2910 t->mq = GNUNET_MQ_queue_for_callbacks (NULL,
2915 &decrypted_error_cb,
2917 t->mst = GNUNET_MST_create (&handle_decrypted,
2924 * Add a @a connection to the @a tunnel.
2927 * @param cid connection identifer to use for the connection
2928 * @param options options for the connection
2929 * @param path path to use for the connection
2930 * @return #GNUNET_OK on success,
2931 * #GNUNET_SYSERR on failure (duplicate connection)
2934 GCT_add_inbound_connection (struct CadetTunnel *t,
2935 const struct GNUNET_CADET_ConnectionTunnelIdentifier *cid,
2936 enum GNUNET_CADET_ChannelOption options,
2937 struct CadetPeerPath *path)
2939 struct CadetTConnection *ct;
2941 ct = GNUNET_new (struct CadetTConnection);
2942 ct->created = GNUNET_TIME_absolute_get ();
2944 ct->cc = GCC_create_inbound (t->destination,
2949 &connection_ready_cb,
2953 LOG (GNUNET_ERROR_TYPE_DEBUG,
2954 "%s refused inbound %s (duplicate)\n",
2958 return GNUNET_SYSERR;
2960 /* FIXME: schedule job to kill connection (and path?) if it takes
2961 too long to get ready! (And track performance data on how long
2962 other connections took with the tunnel!)
2963 => Note: to be done within 'connection'-logic! */
2964 GNUNET_CONTAINER_DLL_insert (t->connection_busy_head,
2965 t->connection_busy_tail,
2967 t->num_busy_connections++;
2968 LOG (GNUNET_ERROR_TYPE_DEBUG,
2977 * Handle encrypted message.
2979 * @param ct connection/tunnel combo that received encrypted message
2980 * @param msg the encrypted message to decrypt
2983 GCT_handle_encrypted (struct CadetTConnection *ct,
2984 const struct GNUNET_CADET_TunnelEncryptedMessage *msg)
2986 struct CadetTunnel *t = ct->t;
2987 uint16_t size = ntohs (msg->header.size);
2988 char cbuf [size] GNUNET_ALIGN;
2989 ssize_t decrypted_size;
2991 LOG (GNUNET_ERROR_TYPE_DEBUG,
2992 "%s received %u bytes of encrypted data in state %d\n",
2994 (unsigned int) size,
2999 case CADET_TUNNEL_KEY_UNINITIALIZED:
3000 case CADET_TUNNEL_KEY_AX_RECV:
3001 /* We did not even SEND our KX, how can the other peer
3002 send us encrypted data? */
3003 GNUNET_break_op (0);
3005 case CADET_TUNNEL_KEY_AX_SENT_AND_RECV:
3006 /* We send KX, and other peer send KX to us at the same time.
3007 Neither KX is AUTH'ed, so let's try KX_AUTH this time. */
3008 GNUNET_STATISTICS_update (stats,
3009 "# received encrypted without KX_AUTH",
3012 if (NULL != t->kx_task)
3014 GNUNET_SCHEDULER_cancel (t->kx_task);
3022 case CADET_TUNNEL_KEY_AX_SENT:
3023 /* We did not get the KX of the other peer, but that
3024 might have been lost. Send our KX again immediately. */
3025 GNUNET_STATISTICS_update (stats,
3026 "# received encrypted without KX",
3029 if (NULL != t->kx_task)
3031 GNUNET_SCHEDULER_cancel (t->kx_task);
3038 case CADET_TUNNEL_KEY_AX_AUTH_SENT:
3039 /* Great, first payload, we might graduate to OK! */
3040 case CADET_TUNNEL_KEY_OK:
3041 /* We are up and running, all good. */
3045 GNUNET_STATISTICS_update (stats,
3046 "# received encrypted",
3049 decrypted_size = -1;
3050 if (CADET_TUNNEL_KEY_OK == t->estate)
3052 /* We have well-established key material available,
3053 try that. (This is the common case.) */
3054 decrypted_size = t_ax_decrypt_and_validate (&t->ax,
3060 if ( (-1 == decrypted_size) &&
3061 (NULL != t->unverified_ax) )
3063 /* We have un-authenticated KX material available. We should try
3064 this as a back-up option, in case the sender crashed and
3066 decrypted_size = t_ax_decrypt_and_validate (t->unverified_ax,
3070 if (-1 != decrypted_size)
3072 /* It worked! Treat this as authentication of the AX data! */
3073 t->ax.DHRs = NULL; /* aliased with ax.DHRs */
3074 t->ax.kx_0 = NULL; /* aliased with ax.DHRs */
3075 cleanup_ax (&t->ax);
3076 t->ax = *t->unverified_ax;
3077 GNUNET_free (t->unverified_ax);
3078 t->unverified_ax = NULL;
3080 if (CADET_TUNNEL_KEY_AX_AUTH_SENT == t->estate)
3082 /* First time it worked, move tunnel into production! */
3083 GCT_change_estate (t,
3084 CADET_TUNNEL_KEY_OK);
3085 if (NULL != t->send_task)
3086 GNUNET_SCHEDULER_cancel (t->send_task);
3087 t->send_task = GNUNET_SCHEDULER_add_now (&trigger_transmissions,
3091 if (NULL != t->unverified_ax)
3093 /* We had unverified KX material that was useless; so increment
3094 counter and eventually move to ignore it. Note that we even do
3095 this increment if we successfully decrypted with the old KX
3096 material and thus didn't even both with the new one. This is
3097 the ideal case, as a malicious injection of bogus KX data
3098 basically only causes us to increment a counter a few times. */
3099 t->unverified_attempts++;
3100 LOG (GNUNET_ERROR_TYPE_DEBUG,
3101 "Failed to decrypt message with unverified KX data %u times\n",
3102 t->unverified_attempts);
3103 if (t->unverified_attempts > MAX_UNVERIFIED_ATTEMPTS)
3105 t->unverified_ax->DHRs = NULL; /* aliased with ax.DHRs */
3106 t->unverified_ax->kx_0 = NULL; /* aliased with ax.DHRs */
3107 cleanup_ax (t->unverified_ax);
3108 GNUNET_free (t->unverified_ax);
3109 t->unverified_ax = NULL;
3113 if (-1 == decrypted_size)
3115 /* Decryption failed for good, complain. */
3116 GNUNET_break_op (0);
3117 LOG (GNUNET_ERROR_TYPE_WARNING,
3118 "%s failed to decrypt and validate encrypted data\n",
3120 GNUNET_STATISTICS_update (stats,
3121 "# unable to decrypt",
3127 /* The MST will ultimately call #handle_decrypted() on each message. */
3129 GNUNET_break_op (GNUNET_OK ==
3130 GNUNET_MST_from_buffer (t->mst,
3135 t->current_ct = NULL;
3140 * Sends an already built message on a tunnel, encrypting it and
3141 * choosing the best connection if not provided.
3143 * @param message Message to send. Function modifies it.
3144 * @param t Tunnel on which this message is transmitted.
3145 * @param cont Continuation to call once message is really sent.
3146 * @param cont_cls Closure for @c cont.
3147 * @return Handle to cancel message
3149 struct CadetTunnelQueueEntry *
3150 GCT_send (struct CadetTunnel *t,
3151 const struct GNUNET_MessageHeader *message,
3152 GCT_SendContinuation cont,
3155 struct CadetTunnelQueueEntry *tq;
3156 uint16_t payload_size;
3157 struct GNUNET_MQ_Envelope *env;
3158 struct GNUNET_CADET_TunnelEncryptedMessage *ax_msg;
3160 if (CADET_TUNNEL_KEY_OK != t->estate)
3165 payload_size = ntohs (message->size);
3166 LOG (GNUNET_ERROR_TYPE_DEBUG,
3167 "Encrypting %u bytes for %s\n",
3168 (unsigned int) payload_size,
3170 env = GNUNET_MQ_msg_extra (ax_msg,
3172 GNUNET_MESSAGE_TYPE_CADET_TUNNEL_ENCRYPTED);
3173 t_ax_encrypt (&t->ax,
3177 ax_msg->ax_header.Ns = htonl (t->ax.Ns++);
3178 ax_msg->ax_header.PNs = htonl (t->ax.PNs);
3179 /* FIXME: we should do this once, not once per message;
3180 this is a point multiplication, and DHRs does not
3181 change all the time. */
3182 GNUNET_CRYPTO_ecdhe_key_get_public (t->ax.DHRs,
3183 &ax_msg->ax_header.DHRs);
3184 t_h_encrypt (&t->ax,
3186 t_hmac (&ax_msg->ax_header,
3187 sizeof (struct GNUNET_CADET_AxHeader) + payload_size,
3192 tq = GNUNET_malloc (sizeof (*tq));
3195 tq->cid = &ax_msg->cid; /* will initialize 'ax_msg->cid' once we know the connection */
3197 tq->cont_cls = cont_cls;
3198 GNUNET_CONTAINER_DLL_insert_tail (t->tq_head,
3201 if (NULL != t->send_task)
3202 GNUNET_SCHEDULER_cancel (t->send_task);
3204 = GNUNET_SCHEDULER_add_now (&trigger_transmissions,
3211 * Cancel a previously sent message while it's in the queue.
3213 * ONLY can be called before the continuation given to the send
3214 * function is called. Once the continuation is called, the message is
3215 * no longer in the queue!
3217 * @param tq Handle to the queue entry to cancel.
3220 GCT_send_cancel (struct CadetTunnelQueueEntry *tq)
3222 struct CadetTunnel *t = tq->t;
3224 GNUNET_CONTAINER_DLL_remove (t->tq_head,
3227 GNUNET_MQ_discard (tq->env);
3233 * Iterate over all connections of a tunnel.
3235 * @param t Tunnel whose connections to iterate.
3236 * @param iter Iterator.
3237 * @param iter_cls Closure for @c iter.
3240 GCT_iterate_connections (struct CadetTunnel *t,
3241 GCT_ConnectionIterator iter,
3244 struct CadetTConnection *n;
3245 for (struct CadetTConnection *ct = t->connection_ready_head;
3253 for (struct CadetTConnection *ct = t->connection_busy_head;
3265 * Closure for #iterate_channels_cb.
3272 GCT_ChannelIterator iter;
3275 * Closure for @e iter.
3282 * Helper function for #GCT_iterate_channels.
3284 * @param cls the `struct ChanIterCls`
3286 * @param value a `struct CadetChannel`
3287 * @return #GNUNET_OK
3290 iterate_channels_cb (void *cls,
3294 struct ChanIterCls *ctx = cls;
3295 struct CadetChannel *ch = value;
3297 ctx->iter (ctx->iter_cls,
3304 * Iterate over all channels of a tunnel.
3306 * @param t Tunnel whose channels to iterate.
3307 * @param iter Iterator.
3308 * @param iter_cls Closure for @c iter.
3311 GCT_iterate_channels (struct CadetTunnel *t,
3312 GCT_ChannelIterator iter,
3315 struct ChanIterCls ctx;
3318 ctx.iter_cls = iter_cls;
3319 GNUNET_CONTAINER_multihashmap32_iterate (t->channels,
3320 &iterate_channels_cb,
3327 * Call #GCCH_debug() on a channel.
3329 * @param cls points to the log level to use
3331 * @param value the `struct CadetChannel` to dump
3332 * @return #GNUNET_OK (continue iteration)
3335 debug_channel (void *cls,
3339 const enum GNUNET_ErrorType *level = cls;
3340 struct CadetChannel *ch = value;
3342 GCCH_debug (ch, *level);
3347 #define LOG2(level, ...) GNUNET_log_from_nocheck(level,"cadet-tun",__VA_ARGS__)
3351 * Log all possible info about the tunnel state.
3353 * @param t Tunnel to debug.
3354 * @param level Debug level to use.
3357 GCT_debug (const struct CadetTunnel *t,
3358 enum GNUNET_ErrorType level)
3360 struct CadetTConnection *iter_c;
3363 do_log = GNUNET_get_log_call_status (level & (~GNUNET_ERROR_TYPE_BULK),
3365 __FILE__, __FUNCTION__, __LINE__);
3370 "TTT TUNNEL TOWARDS %s in estate %s tq_len: %u #cons: %u\n",
3372 estate2s (t->estate),
3374 GCT_count_any_connections (t));
3377 GNUNET_CONTAINER_multihashmap32_iterate (t->channels,
3381 "TTT connections:\n");
3382 for (iter_c = t->connection_ready_head; NULL != iter_c; iter_c = iter_c->next)
3383 GCC_debug (iter_c->cc,
3385 for (iter_c = t->connection_busy_head; NULL != iter_c; iter_c = iter_c->next)
3386 GCC_debug (iter_c->cc,
3390 "TTT TUNNEL END\n");
3394 /* end of gnunet-service-cadet-new_tunnels.c */