2 This file is part of GNUnet.
3 Copyright (C) 2013 Christian Grothoff (and other contributing authors)
5 GNUnet is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published
7 by the Free Software Foundation; either version 3, or (at your
8 option) any later version.
10 GNUnet is distributed in the hope that it will be useful, but
11 WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 General Public License for more details.
15 You should have received a copy of the GNU General Public License
16 along with GNUnet; see the file COPYING. If not, write to the
17 Free Software Foundation, Inc., 59 Temple Place - Suite 330,
18 Boston, MA 02111-1307, USA.
22 #include "gnunet_util_lib.h"
24 #include "gnunet_signatures.h"
25 #include "gnunet_statistics_service.h"
27 #include "cadet_protocol.h"
28 #include "cadet_path.h"
30 #include "gnunet-service-cadet_tunnel.h"
31 #include "gnunet-service-cadet_connection.h"
32 #include "gnunet-service-cadet_channel.h"
33 #include "gnunet-service-cadet_peer.h"
35 #define LOG(level, ...) GNUNET_log_from(level,"cadet-tun",__VA_ARGS__)
36 #define LOG2(level, ...) GNUNET_log_from_nocheck(level,"cadet-tun",__VA_ARGS__)
38 #define REKEY_WAIT GNUNET_TIME_relative_multiply(GNUNET_TIME_UNIT_SECONDS, 5)
40 #if !defined(GNUNET_CULL_LOGGING)
41 #define DUMP_KEYS_TO_STDERR GNUNET_YES
43 #define DUMP_KEYS_TO_STDERR GNUNET_NO
46 /******************************************************************************/
47 /******************************** STRUCTS **********************************/
48 /******************************************************************************/
52 struct CadetTChannel *next;
53 struct CadetTChannel *prev;
54 struct CadetChannel *ch;
59 * Connection list and metadata.
61 struct CadetTConnection
66 struct CadetTConnection *next;
71 struct CadetTConnection *prev;
76 struct CadetConnection *c;
79 * Creation time, to keep oldest connection alive.
81 struct GNUNET_TIME_Absolute created;
84 * Connection throughput, to keep fastest connection alive.
90 * Structure used during a Key eXchange.
92 struct CadetTunnelKXCtx
95 * Encryption ("our") old "confirmed" key, for encrypting traffic sent by us
96 * end before the key exchange is finished or times out.
98 struct GNUNET_CRYPTO_SymmetricSessionKey e_key_old;
101 * Decryption ("their") old "confirmed" key, for decrypting traffic sent by
102 * the other end before the key exchange started.
104 struct GNUNET_CRYPTO_SymmetricSessionKey d_key_old;
107 * Same as @c e_key_old, for the case of two simultaneous KX.
108 * This can happen if cadet decides to start a re-key while the peer has also
109 * started its re-key (due to network delay this is impossible to avoid).
110 * In this case, the key material generated with the peer's old ephemeral
111 * *might* (but doesn't have to) be incorrect.
112 * Since no more than two re-keys can happen simultaneously, this is enough.
114 struct GNUNET_CRYPTO_SymmetricSessionKey e_key_old2;
117 * Same as @c d_key_old, for the case described in @c e_key_old2.
119 struct GNUNET_CRYPTO_SymmetricSessionKey d_key_old2;
122 * Challenge to send and expect in the PONG.
127 * When the rekey started. One minute after this the new key will be used.
129 struct GNUNET_TIME_Absolute rekey_start_time;
132 * Task for delayed destruction of the Key eXchange context, to allow delayed
133 * messages with the old key to be decrypted successfully.
135 struct GNUNET_SCHEDULER_Task * finish_task;
139 * Encryption systems possible.
141 enum CadetTunnelEncryption
144 * Default Axolotl system.
149 * Fallback OTR-style encryption.
154 struct CadetTunnelSkippedKey
156 struct CadetTunnelSkippedKey *next;
157 struct CadetTunnelSkippedKey *prev;
159 struct GNUNET_TIME_Absolute timestamp;
161 struct GNUNET_CRYPTO_SymmetricSessionKey HK;
162 struct GNUNET_CRYPTO_SymmetricSessionKey MK;
166 * Axolotl data, according to https://github.com/trevp/axolotl/wiki
168 struct CadetTunnelAxolotl
171 * A (double linked) list of stored message keys and associated header keys
172 * for "skipped" messages, i.e. messages that have not bee*n
173 * received despite the reception of more recent messages, (head)/
175 struct CadetTunnelSkippedKey *skipped_head;
178 * Skipped messages' keys DLL, tail.
180 struct CadetTunnelSkippedKey *skipped_tail;
183 * Elements in @a skipped_head <-> @a skipped_tail.
188 * 32-byte root key which gets updated by DH ratchet
190 struct GNUNET_CRYPTO_SymmetricSessionKey RK;
193 * 32-byte header key (send)
195 struct GNUNET_CRYPTO_SymmetricSessionKey HKs;
198 * 32-byte header key (recv)
200 struct GNUNET_CRYPTO_SymmetricSessionKey HKr;
203 * 32-byte next header key (send)
205 struct GNUNET_CRYPTO_SymmetricSessionKey NHKs;
208 * 32-byte next header key (recv)
210 struct GNUNET_CRYPTO_SymmetricSessionKey NHKr;
213 * 32-byte chain keys (used for forward-secrecy updating, send)
215 struct GNUNET_CRYPTO_SymmetricSessionKey CKs;
218 * 32-byte chain keys (used for forward-secrecy updating, recv)
220 struct GNUNET_CRYPTO_SymmetricSessionKey CKr;
223 * ECDH Ratchet key (send)
225 struct GNUNET_CRYPTO_EcdhePrivateKey *DHRs;
228 * ECDH Ratchet key (recv)
230 struct GNUNET_CRYPTO_EcdhePublicKey DHRr;
233 * Message number (reset to 0 with each new ratchet, send)
238 * Message numbers (reset to 0 with each new ratchet, recv)
243 * Previous message numbers (# of msgs sent under prev ratchet)
248 * True (#GNUNET_YES) if the party will send a new ratchet key in next msg.
254 * Struct containing all information regarding a tunnel to a peer.
259 * Endpoint of the tunnel.
261 struct CadetPeer *peer;
264 * Type of encryption used in the tunnel.
266 enum CadetTunnelEncryption enc_type;
271 struct CadetTunnelAxolotl *ax;
274 * State of the tunnel connectivity.
276 enum CadetTunnelCState cstate;
279 * State of the tunnel encryption.
281 enum CadetTunnelEState estate;
284 * Key eXchange context.
286 struct CadetTunnelKXCtx *kx_ctx;
289 * Peer's ephemeral key, to recreate @c e_key and @c d_key when own ephemeral
292 struct GNUNET_CRYPTO_EcdhePublicKey peers_ephemeral_key;
295 * Encryption ("our") key. It is only "confirmed" if kx_ctx is NULL.
297 struct GNUNET_CRYPTO_SymmetricSessionKey e_key;
300 * Decryption ("their") key. It is only "confirmed" if kx_ctx is NULL.
302 struct GNUNET_CRYPTO_SymmetricSessionKey d_key;
305 * Task to start the rekey process.
307 struct GNUNET_SCHEDULER_Task * rekey_task;
310 * Paths that are actively used to reach the destination peer.
312 struct CadetTConnection *connection_head;
313 struct CadetTConnection *connection_tail;
316 * Next connection number.
321 * Channels inside this tunnel.
323 struct CadetTChannel *channel_head;
324 struct CadetTChannel *channel_tail;
327 * Channel ID for the next created channel.
329 CADET_ChannelNumber next_chid;
332 * Destroy flag: if true, destroy on last message.
334 struct GNUNET_SCHEDULER_Task * destroy_task;
337 * Queued messages, to transmit once tunnel gets connected.
339 struct CadetTunnelDelayed *tq_head;
340 struct CadetTunnelDelayed *tq_tail;
343 * Task to trim connections if too many are present.
345 struct GNUNET_SCHEDULER_Task * trim_connections_task;
348 * Ephemeral message in the queue (to avoid queueing more than one).
350 struct CadetConnectionQueue *ephm_h;
353 * Pong message in the queue.
355 struct CadetConnectionQueue *pong_h;
360 * Struct used to save messages in a non-ready tunnel to send once connected.
362 struct CadetTunnelDelayed
367 struct CadetTunnelDelayed *next;
368 struct CadetTunnelDelayed *prev;
373 struct CadetTunnel *t;
376 * Tunnel queue given to the channel to cancel request. Update on send_queued.
378 struct CadetTunnelQueue *tq;
383 /* struct GNUNET_MessageHeader *msg; */
388 * Handle for messages queued but not yet sent.
390 struct CadetTunnelQueue
393 * Connection queue handle, to cancel if necessary.
395 struct CadetConnectionQueue *cq;
398 * Handle in case message hasn't been given to a connection yet.
400 struct CadetTunnelDelayed *tqd;
403 * Continuation to call once sent.
408 * Closure for @c cont.
414 /******************************************************************************/
415 /******************************* GLOBALS ***********************************/
416 /******************************************************************************/
419 * Global handle to the statistics service.
421 extern struct GNUNET_STATISTICS_Handle *stats;
424 * Local peer own ID (memory efficient handle).
426 extern GNUNET_PEER_Id myid;
429 * Local peer own ID (full value).
431 extern struct GNUNET_PeerIdentity my_full_id;
435 * Don't try to recover tunnels if shutting down.
437 extern int shutting_down;
441 * Set of all tunnels, in order to trigger a new exchange on rekey.
442 * Indexed by peer's ID.
444 static struct GNUNET_CONTAINER_MultiPeerMap *tunnels;
447 * Default TTL for payload packets.
449 static unsigned long long default_ttl;
454 const static struct GNUNET_CRYPTO_EddsaPrivateKey *my_private_key;
457 * Own Axolotl private key (derived from @a my_private_key).
459 const struct GNUNET_CRYPTO_EcdhePrivateKey *ax_identity;
462 * Own OTR ephemeral private key.
464 static struct GNUNET_CRYPTO_EcdhePrivateKey *my_ephemeral_key;
467 * Cached message used to perform a key exchange.
469 static struct GNUNET_CADET_KX_Ephemeral kx_msg;
472 * Task to generate a new ephemeral key.
474 static struct GNUNET_SCHEDULER_Task * rekey_task;
479 static struct GNUNET_TIME_Relative rekey_period;
482 /******************************************************************************/
483 /******************************** STATIC ***********************************/
484 /******************************************************************************/
487 * Get string description for tunnel connectivity state.
489 * @param cs Tunnel state.
491 * @return String representation.
494 cstate2s (enum CadetTunnelCState cs)
500 case CADET_TUNNEL_NEW:
501 return "CADET_TUNNEL_NEW";
502 case CADET_TUNNEL_SEARCHING:
503 return "CADET_TUNNEL_SEARCHING";
504 case CADET_TUNNEL_WAITING:
505 return "CADET_TUNNEL_WAITING";
506 case CADET_TUNNEL_READY:
507 return "CADET_TUNNEL_READY";
508 case CADET_TUNNEL_SHUTDOWN:
509 return "CADET_TUNNEL_SHUTDOWN";
511 SPRINTF (buf, "%u (UNKNOWN STATE)", cs);
519 * Get string description for tunnel encryption state.
521 * @param es Tunnel state.
523 * @return String representation.
526 estate2s (enum CadetTunnelEState es)
532 case CADET_TUNNEL_KEY_UNINITIALIZED:
533 return "CADET_TUNNEL_KEY_UNINITIALIZED";
534 case CADET_TUNNEL_KEY_SENT:
535 return "CADET_TUNNEL_KEY_SENT";
536 case CADET_TUNNEL_KEY_PING:
537 return "CADET_TUNNEL_KEY_PING";
538 case CADET_TUNNEL_KEY_OK:
539 return "CADET_TUNNEL_KEY_OK";
540 case CADET_TUNNEL_KEY_REKEY:
541 return "CADET_TUNNEL_KEY_REKEY";
543 SPRINTF (buf, "%u (UNKNOWN STATE)", es);
551 * @brief Check if tunnel is ready to send traffic.
553 * Tunnel must be connected and with encryption correctly set up.
555 * @param t Tunnel to check.
557 * @return #GNUNET_YES if ready, #GNUNET_NO otherwise
560 is_ready (struct CadetTunnel *t)
564 GCT_debug (t, GNUNET_ERROR_TYPE_DEBUG);
565 ready = CADET_TUNNEL_READY == t->cstate
566 && (CADET_TUNNEL_KEY_OK == t->estate
567 || CADET_TUNNEL_KEY_REKEY == t->estate);
568 ready = ready || GCT_is_loopback (t);
574 * Check if a key is invalid (NULL pointer or all 0)
576 * @param key Key to check.
578 * @return #GNUNET_YES if key is null, #GNUNET_NO if exists and is not 0.
581 is_key_null (struct GNUNET_CRYPTO_SymmetricSessionKey *key)
583 struct GNUNET_CRYPTO_SymmetricSessionKey null_key;
588 memset (&null_key, 0, sizeof (null_key));
589 if (0 == memcmp (key, &null_key, sizeof (null_key)))
596 * Ephemeral key message purpose size.
598 * @return Size of the part of the ephemeral key message that must be signed.
601 ephemeral_purpose_size (void)
603 return sizeof (struct GNUNET_CRYPTO_EccSignaturePurpose) +
604 sizeof (struct GNUNET_TIME_AbsoluteNBO) +
605 sizeof (struct GNUNET_TIME_AbsoluteNBO) +
606 sizeof (struct GNUNET_CRYPTO_EcdhePublicKey) +
607 sizeof (struct GNUNET_PeerIdentity);
612 * Size of the encrypted part of a ping message.
614 * @return Size of the encrypted part of a ping message.
617 ping_encryption_size (void)
619 return sizeof (uint32_t);
624 * Get the channel's buffer. ONLY FOR NON-LOOPBACK CHANNELS!!
626 * @param tch Tunnel's channel handle.
628 * @return Amount of messages the channel can still buffer towards the client.
631 get_channel_buffer (const struct CadetTChannel *tch)
635 /* If channel is incoming, is terminal in the FWD direction and fwd is YES */
636 fwd = GCCH_is_terminal (tch->ch, GNUNET_YES);
638 return GCCH_get_buffer (tch->ch, fwd);
643 * Get the channel's allowance status.
645 * @param tch Tunnel's channel handle.
647 * @return #GNUNET_YES if we allowed the client to send data to us.
650 get_channel_allowed (const struct CadetTChannel *tch)
654 /* If channel is outgoing, is origin in the FWD direction and fwd is YES */
655 fwd = GCCH_is_origin (tch->ch, GNUNET_YES);
657 return GCCH_get_allowed (tch->ch, fwd);
662 * Get the connection's buffer.
664 * @param tc Tunnel's connection handle.
666 * @return Amount of messages the connection can still buffer.
669 get_connection_buffer (const struct CadetTConnection *tc)
673 /* If connection is outgoing, is origin in the FWD direction and fwd is YES */
674 fwd = GCC_is_origin (tc->c, GNUNET_YES);
676 return GCC_get_buffer (tc->c, fwd);
681 * Get the connection's allowance.
683 * @param tc Tunnel's connection handle.
685 * @return Amount of messages we have allowed the next peer to send us.
688 get_connection_allowed (const struct CadetTConnection *tc)
692 /* If connection is outgoing, is origin in the FWD direction and fwd is YES */
693 fwd = GCC_is_origin (tc->c, GNUNET_YES);
695 return GCC_get_allowed (tc->c, fwd);
700 * Check that a ephemeral key message s well formed and correctly signed.
702 * @param t Tunnel on which the message came.
703 * @param msg The ephemeral key message.
705 * @return GNUNET_OK if message is fine, GNUNET_SYSERR otherwise.
708 check_ephemeral (struct CadetTunnel *t,
709 const struct GNUNET_CADET_KX_Ephemeral *msg)
711 /* Check message size */
712 if (ntohs (msg->header.size) != sizeof (struct GNUNET_CADET_KX_Ephemeral))
713 return GNUNET_SYSERR;
715 /* Check signature size */
716 if (ntohl (msg->purpose.size) != ephemeral_purpose_size ())
717 return GNUNET_SYSERR;
720 if (0 != memcmp (&msg->origin_identity,
721 GCP_get_id (t->peer),
722 sizeof (struct GNUNET_PeerIdentity)))
723 return GNUNET_SYSERR;
725 /* Check signature */
727 GNUNET_CRYPTO_eddsa_verify (GNUNET_SIGNATURE_PURPOSE_CADET_KX,
730 &msg->origin_identity.public_key))
731 return GNUNET_SYSERR;
738 * Select the best key to use for encryption (send), based on KX status.
740 * Normally, return the current key. If there is a KX in progress and the old
741 * key is fresh enough, return the old key.
743 * @param t Tunnel to choose the key from.
745 * @return The optimal key to encrypt/hmac outgoing traffic.
747 static const struct GNUNET_CRYPTO_SymmetricSessionKey *
748 select_key (const struct CadetTunnel *t)
750 const struct GNUNET_CRYPTO_SymmetricSessionKey *key;
752 if (NULL != t->kx_ctx
753 && NULL == t->kx_ctx->finish_task)
755 struct GNUNET_TIME_Relative age;
757 age = GNUNET_TIME_absolute_get_duration (t->kx_ctx->rekey_start_time);
758 LOG (GNUNET_ERROR_TYPE_DEBUG,
759 " key exchange in progress, started %s ago\n",
760 GNUNET_STRINGS_relative_time_to_string (age, GNUNET_YES));
761 // FIXME make duration of old keys configurable
762 if (age.rel_value_us < GNUNET_TIME_UNIT_MINUTES.rel_value_us)
764 LOG (GNUNET_ERROR_TYPE_DEBUG, " using old key\n");
765 key = &t->kx_ctx->e_key_old;
769 LOG (GNUNET_ERROR_TYPE_DEBUG, " using new key (old key too old)\n");
775 LOG (GNUNET_ERROR_TYPE_DEBUG, " no KX: using current key\n");
785 * @param plaintext Content to HMAC.
786 * @param size Size of @c plaintext.
787 * @param iv Initialization vector for the message.
788 * @param key Key to use.
789 * @param hmac[out] Destination to store the HMAC.
792 t_hmac (const void *plaintext, size_t size,
793 uint32_t iv, const struct GNUNET_CRYPTO_SymmetricSessionKey *key,
794 struct GNUNET_CADET_Hash *hmac)
796 static const char ctx[] = "cadet authentication key";
797 struct GNUNET_CRYPTO_AuthKey auth_key;
798 struct GNUNET_HashCode hash;
800 #if DUMP_KEYS_TO_STDERR
801 LOG (GNUNET_ERROR_TYPE_INFO, " HMAC with key %s\n",
802 GNUNET_h2s ((struct GNUNET_HashCode *) key));
804 GNUNET_CRYPTO_hmac_derive_key (&auth_key, key,
809 /* Two step: CADET_Hash is only 256 bits, HashCode is 512. */
810 GNUNET_CRYPTO_hmac (&auth_key, plaintext, size, &hash);
811 memcpy (hmac, &hash, sizeof (*hmac));
816 * Encrypt daforce_newest_keyta with the tunnel key.
818 * @param t Tunnel whose key to use.
819 * @param dst Destination for the encrypted data.
820 * @param src Source of the plaintext. Can overlap with @c dst.
821 * @param size Size of the plaintext.
822 * @param iv Initialization Vector to use.
823 * @param force_newest_key Force the use of the newest key, otherwise
824 * CADET will use the old key when allowed.
825 * This can happen in the case when a KX is going on
826 * and the old one hasn't expired.
829 t_encrypt (struct CadetTunnel *t, void *dst, const void *src,
830 size_t size, uint32_t iv, int force_newest_key)
832 struct GNUNET_CRYPTO_SymmetricInitializationVector siv;
833 const struct GNUNET_CRYPTO_SymmetricSessionKey *key;
836 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_encrypt start\n");
838 key = GNUNET_YES == force_newest_key ? &t->e_key : select_key (t);
839 #if DUMP_KEYS_TO_STDERR
840 LOG (GNUNET_ERROR_TYPE_INFO, " ENC with key %s\n",
841 GNUNET_h2s ((struct GNUNET_HashCode *) key));
843 GNUNET_CRYPTO_symmetric_derive_iv (&siv, key, &iv, sizeof (iv), NULL);
844 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_encrypt IV derived\n");
845 out_size = GNUNET_CRYPTO_symmetric_encrypt (src, size, key, &siv, dst);
846 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_encrypt end\n");
853 * Decrypt and verify data with the appropriate tunnel key.
855 * @param key Key to use.
856 * @param dst Destination for the plaintext.
857 * @param src Source of the encrypted data. Can overlap with @c dst.
858 * @param size Size of the encrypted data.
859 * @param iv Initialization Vector to use.
861 * @return Size of the decrypted data, -1 if an error was encountered.
864 decrypt (const struct GNUNET_CRYPTO_SymmetricSessionKey *key,
865 void *dst, const void *src, size_t size, uint32_t iv)
867 struct GNUNET_CRYPTO_SymmetricInitializationVector siv;
870 LOG (GNUNET_ERROR_TYPE_DEBUG, " decrypt start\n");
871 LOG (GNUNET_ERROR_TYPE_DEBUG, " decrypt iv\n");
872 GNUNET_CRYPTO_symmetric_derive_iv (&siv, key, &iv, sizeof (iv), NULL);
873 LOG (GNUNET_ERROR_TYPE_DEBUG, " decrypt iv done\n");
874 out_size = GNUNET_CRYPTO_symmetric_decrypt (src, size, key, &siv, dst);
875 LOG (GNUNET_ERROR_TYPE_DEBUG, " decrypt end\n");
882 * Decrypt and verify data with the most recent tunnel key.
884 * @param t Tunnel whose key to use.
885 * @param dst Destination for the plaintext.
886 * @param src Source of the encrypted data. Can overlap with @c dst.
887 * @param size Size of the encrypted data.
888 * @param iv Initialization Vector to use.
890 * @return Size of the decrypted data, -1 if an error was encountered.
893 t_decrypt (struct CadetTunnel *t, void *dst, const void *src,
894 size_t size, uint32_t iv)
898 #if DUMP_KEYS_TO_STDERR
899 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_decrypt with %s\n",
900 GNUNET_h2s ((struct GNUNET_HashCode *) &t->d_key));
902 if (CADET_TUNNEL_KEY_UNINITIALIZED == t->estate)
904 GNUNET_STATISTICS_update (stats, "# non decryptable data", 1, GNUNET_NO);
905 LOG (GNUNET_ERROR_TYPE_WARNING,
906 "got data on %s without a valid key\n",
908 GCT_debug (t, GNUNET_ERROR_TYPE_WARNING);
912 out_size = decrypt (&t->d_key, dst, src, size, iv);
919 * Decrypt and verify data with the appropriate tunnel key and verify that the
920 * data has not been altered since it was sent by the remote peer.
922 * @param t Tunnel whose key to use.
923 * @param dst Destination for the plaintext.
924 * @param src Source of the encrypted data. Can overlap with @c dst.
925 * @param size Size of the encrypted data.
926 * @param iv Initialization Vector to use.
927 * @param msg_hmac HMAC of the message, cannot be NULL.
929 * @return Size of the decrypted data, -1 if an error was encountered.
932 t_decrypt_and_validate (struct CadetTunnel *t,
933 void *dst, const void *src,
934 size_t size, uint32_t iv,
935 const struct GNUNET_CADET_Hash *msg_hmac)
937 struct GNUNET_CRYPTO_SymmetricSessionKey *key;
938 struct GNUNET_CADET_Hash hmac;
941 /* Try primary (newest) key */
943 decrypted_size = decrypt (key, dst, src, size, iv);
944 t_hmac (src, size, iv, key, &hmac);
945 if (0 == memcmp (msg_hmac, &hmac, sizeof (hmac)))
946 return decrypted_size;
948 /* If no key exchange is going on, we just failed. */
949 if (NULL == t->kx_ctx)
951 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
952 "Failed checksum validation on tunnel %s with no KX\n",
954 GNUNET_STATISTICS_update (stats, "# wrong HMAC no KX", 1, GNUNET_NO);
958 /* Try secondary key, from previous KX period. */
959 key = &t->kx_ctx->d_key_old;
960 decrypted_size = decrypt (key, dst, src, size, iv);
961 t_hmac (src, size, iv, key, &hmac);
962 if (0 == memcmp (msg_hmac, &hmac, sizeof (hmac)))
963 return decrypted_size;
965 /* Hail Mary, try tertiary, key, in case of parallel re-keys. */
966 key = &t->kx_ctx->d_key_old2;
967 decrypted_size = decrypt (key, dst, src, size, iv);
968 t_hmac (src, size, iv, key, &hmac);
969 if (0 == memcmp (msg_hmac, &hmac, sizeof (hmac)))
970 return decrypted_size;
972 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
973 "Failed checksum validation on tunnel %s with KX\n",
975 GNUNET_STATISTICS_update (stats, "# wrong HMAC with KX", 1, GNUNET_NO);
980 * Decrypt and verify data with the appropriate tunnel key and verify that the
981 * data has not been altered since it was sent by the remote peer.
983 * @param t Tunnel whose key to use.
984 * @param dst Destination for the plaintext.
985 * @param src Source of the encrypted data. Can overlap with @c dst.
986 * @param size Size of the encrypted data.
987 * @param msg_hmac HMAC of the message, cannot be NULL.
989 * @return Size of the decrypted data, -1 if an error was encountered.
992 t_ax_decrypt_and_validate (struct CadetTunnel *t,
993 void *dst, const void *src, size_t size,
994 const struct GNUNET_CADET_Hash *msg_hmac)
996 struct CadetTunnelAxolotl *ax;
1008 * Create key material by doing ECDH on the local and remote ephemeral keys.
1010 * @param key_material Where to store the key material.
1011 * @param ephemeral_key Peer's public ephemeral key.
1014 derive_key_material (struct GNUNET_HashCode *key_material,
1015 const struct GNUNET_CRYPTO_EcdhePublicKey *ephemeral_key)
1018 GNUNET_CRYPTO_ecc_ecdh (my_ephemeral_key,
1028 * Create a symmetic key from the identities of both ends and the key material
1031 * @param key Destination for the generated key.
1032 * @param sender ID of the peer that will encrypt with @c key.
1033 * @param receiver ID of the peer that will decrypt with @c key.
1034 * @param key_material Hash created with ECDH with the ephemeral keys.
1037 derive_symmertic (struct GNUNET_CRYPTO_SymmetricSessionKey *key,
1038 const struct GNUNET_PeerIdentity *sender,
1039 const struct GNUNET_PeerIdentity *receiver,
1040 const struct GNUNET_HashCode *key_material)
1042 const char salt[] = "CADET kx salt";
1044 GNUNET_CRYPTO_kdf (key, sizeof (struct GNUNET_CRYPTO_SymmetricSessionKey),
1045 salt, sizeof (salt),
1046 key_material, sizeof (struct GNUNET_HashCode),
1047 sender, sizeof (struct GNUNET_PeerIdentity),
1048 receiver, sizeof (struct GNUNET_PeerIdentity),
1054 * Derive the tunnel's keys using our own and the peer's ephemeral keys.
1056 * @param t Tunnel for which to create the keys.
1059 create_keys (struct CadetTunnel *t)
1061 struct GNUNET_HashCode km;
1063 derive_key_material (&km, &t->peers_ephemeral_key);
1064 derive_symmertic (&t->e_key, &my_full_id, GCP_get_id (t->peer), &km);
1065 derive_symmertic (&t->d_key, GCP_get_id (t->peer), &my_full_id, &km);
1066 #if DUMP_KEYS_TO_STDERR
1067 LOG (GNUNET_ERROR_TYPE_INFO, "ME: %s\n",
1068 GNUNET_h2s ((struct GNUNET_HashCode *) &kx_msg.ephemeral_key));
1069 LOG (GNUNET_ERROR_TYPE_INFO, "PE: %s\n",
1070 GNUNET_h2s ((struct GNUNET_HashCode *) &t->peers_ephemeral_key));
1071 LOG (GNUNET_ERROR_TYPE_INFO, "KM: %s\n", GNUNET_h2s (&km));
1072 LOG (GNUNET_ERROR_TYPE_INFO, "EK: %s\n",
1073 GNUNET_h2s ((struct GNUNET_HashCode *) &t->e_key));
1074 LOG (GNUNET_ERROR_TYPE_INFO, "DK: %s\n",
1075 GNUNET_h2s ((struct GNUNET_HashCode *) &t->d_key));
1081 * Create a new Key eXchange context for the tunnel.
1083 * If the old keys were verified, keep them for old traffic. Create a new KX
1084 * timestamp and a new nonce.
1086 * @param t Tunnel for which to create the KX ctx.
1089 create_kx_ctx (struct CadetTunnel *t)
1091 LOG (GNUNET_ERROR_TYPE_INFO, " new kx ctx for %s\n", GCT_2s (t));
1093 if (NULL != t->kx_ctx)
1095 if (NULL != t->kx_ctx->finish_task)
1097 LOG (GNUNET_ERROR_TYPE_INFO, " resetting exisiting finish task\n");
1098 GNUNET_SCHEDULER_cancel (t->kx_ctx->finish_task);
1099 t->kx_ctx->finish_task = NULL;
1104 t->kx_ctx = GNUNET_new (struct CadetTunnelKXCtx);
1105 t->kx_ctx->challenge = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE,
1109 if (CADET_TUNNEL_KEY_OK == t->estate)
1111 LOG (GNUNET_ERROR_TYPE_INFO, " backing up keys\n");
1112 t->kx_ctx->d_key_old = t->d_key;
1113 t->kx_ctx->e_key_old = t->e_key;
1116 LOG (GNUNET_ERROR_TYPE_INFO, " old keys not valid, not saving\n");
1117 t->kx_ctx->rekey_start_time = GNUNET_TIME_absolute_get ();
1123 * @brief Finish the Key eXchange and destroy the old keys.
1125 * @param cls Closure (Tunnel for which to finish the KX).
1126 * @param tc Task context.
1129 finish_kx (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
1131 struct CadetTunnel *t = cls;
1133 LOG (GNUNET_ERROR_TYPE_INFO, "finish KX for %s\n", GCT_2s (t));
1135 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
1137 LOG (GNUNET_ERROR_TYPE_INFO, " shutdown\n");
1141 GNUNET_free (t->kx_ctx);
1147 * Destroy a Key eXchange context for the tunnel. This function only schedules
1148 * the destruction, the freeing of the memory (and clearing of old key material)
1149 * happens after a delay!
1151 * @param t Tunnel whose KX ctx to destroy.
1154 destroy_kx_ctx (struct CadetTunnel *t)
1156 struct GNUNET_TIME_Relative delay;
1158 if (NULL == t->kx_ctx || NULL != t->kx_ctx->finish_task)
1161 if (is_key_null (&t->kx_ctx->e_key_old))
1163 t->kx_ctx->finish_task = GNUNET_SCHEDULER_add_now (finish_kx, t);
1167 delay = GNUNET_TIME_relative_divide (rekey_period, 4);
1168 delay = GNUNET_TIME_relative_min (delay, GNUNET_TIME_UNIT_MINUTES);
1170 t->kx_ctx->finish_task = GNUNET_SCHEDULER_add_delayed (delay, finish_kx, t);
1176 * Pick a connection on which send the next data message.
1178 * @param t Tunnel on which to send the message.
1180 * @return The connection on which to send the next message.
1182 static struct CadetConnection *
1183 tunnel_get_connection (struct CadetTunnel *t)
1185 struct CadetTConnection *iter;
1186 struct CadetConnection *best;
1188 unsigned int lowest_q;
1190 LOG (GNUNET_ERROR_TYPE_DEBUG, "tunnel_get_connection %s\n", GCT_2s (t));
1192 lowest_q = UINT_MAX;
1193 for (iter = t->connection_head; NULL != iter; iter = iter->next)
1195 LOG (GNUNET_ERROR_TYPE_DEBUG, " connection %s: %u\n",
1196 GCC_2s (iter->c), GCC_get_state (iter->c));
1197 if (CADET_CONNECTION_READY == GCC_get_state (iter->c))
1199 qn = GCC_get_qn (iter->c, GCC_is_origin (iter->c, GNUNET_YES));
1200 LOG (GNUNET_ERROR_TYPE_DEBUG, " q_n %u, \n", qn);
1208 LOG (GNUNET_ERROR_TYPE_DEBUG, " selected: connection %s\n", GCC_2s (best));
1214 * Callback called when a queued message is sent.
1216 * Calculates the average time and connection packet tracking.
1218 * @param cls Closure (TunnelQueue handle).
1219 * @param c Connection this message was on.
1220 * @param q Connection queue handle (unused).
1221 * @param type Type of message sent.
1222 * @param fwd Was this a FWD going message?
1223 * @param size Size of the message.
1226 tun_message_sent (void *cls,
1227 struct CadetConnection *c,
1228 struct CadetConnectionQueue *q,
1229 uint16_t type, int fwd, size_t size)
1231 struct CadetTunnelQueue *qt = cls;
1232 struct CadetTunnel *t;
1234 LOG (GNUNET_ERROR_TYPE_DEBUG, "tun_message_sent\n");
1236 GNUNET_assert (NULL != qt->cont);
1237 t = NULL == c ? NULL : GCC_get_tunnel (c);
1238 qt->cont (qt->cont_cls, t, qt, type, size);
1244 count_queued_data (const struct CadetTunnel *t)
1246 struct CadetTunnelDelayed *iter;
1249 for (count = 0, iter = t->tq_head; iter != NULL; iter = iter->next)
1256 * Delete a queued message: either was sent or the channel was destroyed
1257 * before the tunnel's key exchange had a chance to finish.
1259 * @param tqd Delayed queue handle.
1262 unqueue_data (struct CadetTunnelDelayed *tqd)
1264 GNUNET_CONTAINER_DLL_remove (tqd->t->tq_head, tqd->t->tq_tail, tqd);
1270 * Cache a message to be sent once tunnel is online.
1272 * @param t Tunnel to hold the message.
1273 * @param msg Message itself (copy will be made).
1275 static struct CadetTunnelDelayed *
1276 queue_data (struct CadetTunnel *t, const struct GNUNET_MessageHeader *msg)
1278 struct CadetTunnelDelayed *tqd;
1279 uint16_t size = ntohs (msg->size);
1281 LOG (GNUNET_ERROR_TYPE_DEBUG, "queue data on Tunnel %s\n", GCT_2s (t));
1283 if (GNUNET_YES == is_ready (t))
1289 tqd = GNUNET_malloc (sizeof (struct CadetTunnelDelayed) + size);
1292 memcpy (&tqd[1], msg, size);
1293 GNUNET_CONTAINER_DLL_insert_tail (t->tq_head, t->tq_tail, tqd);
1299 * Sends an already built message on a tunnel, encrypting it and
1300 * choosing the best connection.
1302 * @param message Message to send. Function modifies it.
1303 * @param t Tunnel on which this message is transmitted.
1304 * @param c Connection to use (autoselect if NULL).
1305 * @param force Force the tunnel to take the message (buffer overfill).
1306 * @param cont Continuation to call once message is really sent.
1307 * @param cont_cls Closure for @c cont.
1308 * @param existing_q In case this a transmission of previously queued data,
1309 * this should be TunnelQueue given to the client.
1312 * @return Handle to cancel message.
1313 * NULL if @c cont is NULL or an error happens and message is dropped.
1315 static struct CadetTunnelQueue *
1316 send_prebuilt_message (const struct GNUNET_MessageHeader *message,
1317 struct CadetTunnel *t, struct CadetConnection *c,
1318 int force, GCT_sent cont, void *cont_cls,
1319 struct CadetTunnelQueue *existing_q)
1321 struct CadetTunnelQueue *tq;
1322 struct GNUNET_CADET_Encrypted *msg;
1323 size_t size = ntohs (message->size);
1324 char cbuf[sizeof (struct GNUNET_CADET_Encrypted) + size];
1330 LOG (GNUNET_ERROR_TYPE_DEBUG, "GMT Send on Tunnel %s\n", GCT_2s (t));
1332 if (GNUNET_NO == is_ready (t))
1334 struct CadetTunnelDelayed *tqd;
1335 /* A non null existing_q indicates sending of queued data.
1336 * Should only happen after tunnel becomes ready.
1338 GNUNET_assert (NULL == existing_q);
1339 tqd = queue_data (t, message);
1342 tq = GNUNET_new (struct CadetTunnelQueue);
1346 tq->cont_cls = cont_cls;
1350 GNUNET_assert (GNUNET_NO == GCT_is_loopback (t));
1352 iv = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX);
1353 msg = (struct GNUNET_CADET_Encrypted *) cbuf;
1354 msg->header.type = htons (GNUNET_MESSAGE_TYPE_CADET_ENCRYPTED);
1356 GNUNET_assert (t_encrypt (t, &msg[1], message, size, iv, GNUNET_NO) == size);
1357 t_hmac (&msg[1], size, iv, select_key (t), &msg->hmac);
1358 msg->header.size = htons (sizeof (struct GNUNET_CADET_Encrypted) + size);
1361 c = tunnel_get_connection (t);
1364 /* Why is tunnel 'ready'? Should have been queued! */
1365 if (NULL != t->destroy_task)
1368 GCT_debug (t, GNUNET_ERROR_TYPE_WARNING);
1370 return NULL; /* Drop... */
1374 type = ntohs (message->type);
1377 case GNUNET_MESSAGE_TYPE_CADET_DATA:
1378 case GNUNET_MESSAGE_TYPE_CADET_DATA_ACK:
1379 if (GNUNET_MESSAGE_TYPE_CADET_DATA == type)
1380 mid = ntohl (((struct GNUNET_CADET_Data *) message)->mid);
1382 mid = ntohl (((struct GNUNET_CADET_DataACK *) message)->mid);
1384 case GNUNET_MESSAGE_TYPE_CADET_KEEPALIVE:
1385 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_CREATE:
1386 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_DESTROY:
1387 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_ACK:
1388 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_NACK:
1389 msg->cid = *GCC_get_id (c);
1390 msg->ttl = htonl (default_ttl);
1394 LOG (GNUNET_ERROR_TYPE_ERROR, "type %s not valid\n", GC_m2s (type));
1396 LOG (GNUNET_ERROR_TYPE_DEBUG, "type %s\n", GC_m2s (type));
1398 fwd = GCC_is_origin (c, GNUNET_YES);
1402 GNUNET_break (NULL == GCC_send_prebuilt_message (&msg->header, type, mid, c,
1403 fwd, force, NULL, NULL));
1406 if (NULL == existing_q)
1408 tq = GNUNET_new (struct CadetTunnelQueue); /* FIXME valgrind: leak*/
1415 tq->cq = GCC_send_prebuilt_message (&msg->header, type, mid, c, fwd, force,
1416 &tun_message_sent, tq);
1417 GNUNET_assert (NULL != tq->cq);
1419 tq->cont_cls = cont_cls;
1426 * Send all cached messages that we can, tunnel is online.
1428 * @param t Tunnel that holds the messages. Cannot be loopback.
1431 send_queued_data (struct CadetTunnel *t)
1433 struct CadetTunnelDelayed *tqd;
1434 struct CadetTunnelDelayed *next;
1437 LOG (GNUNET_ERROR_TYPE_INFO, "Send queued data, tunnel %s\n", GCT_2s (t));
1439 if (GCT_is_loopback (t))
1445 if (GNUNET_NO == is_ready (t))
1447 LOG (GNUNET_ERROR_TYPE_DEBUG, " not ready yet: %s/%s\n",
1448 estate2s (t->estate), cstate2s (t->cstate));
1452 room = GCT_get_connections_buffer (t);
1453 LOG (GNUNET_ERROR_TYPE_DEBUG, " buffer space: %u\n", room);
1454 LOG (GNUNET_ERROR_TYPE_DEBUG, " tq head: %p\n", t->tq_head);
1455 for (tqd = t->tq_head; NULL != tqd && room > 0; tqd = next)
1457 LOG (GNUNET_ERROR_TYPE_DEBUG, " sending queued data\n");
1460 send_prebuilt_message ((struct GNUNET_MessageHeader *) &tqd[1],
1461 tqd->t, NULL, GNUNET_YES,
1462 NULL != tqd->tq ? tqd->tq->cont : NULL,
1463 NULL != tqd->tq ? tqd->tq->cont_cls : NULL,
1467 LOG (GNUNET_ERROR_TYPE_DEBUG, "GCT_send_queued_data end\n", GCP_2s (t->peer));
1472 * Callback called when a queued message is sent.
1474 * @param cls Closure.
1475 * @param c Connection this message was on.
1476 * @param type Type of message sent.
1477 * @param fwd Was this a FWD going message?
1478 * @param size Size of the message.
1481 ephm_sent (void *cls,
1482 struct CadetConnection *c,
1483 struct CadetConnectionQueue *q,
1484 uint16_t type, int fwd, size_t size)
1486 struct CadetTunnel *t = cls;
1487 LOG (GNUNET_ERROR_TYPE_DEBUG, "ephm_sent %s\n", GC_m2s (type));
1492 * Callback called when a queued message is sent.
1494 * @param cls Closure.
1495 * @param c Connection this message was on.
1496 * @param type Type of message sent.
1497 * @param fwd Was this a FWD going message?
1498 * @param size Size of the message.
1501 pong_sent (void *cls,
1502 struct CadetConnection *c,
1503 struct CadetConnectionQueue *q,
1504 uint16_t type, int fwd, size_t size)
1506 struct CadetTunnel *t = cls;
1507 LOG (GNUNET_ERROR_TYPE_DEBUG, "pong_sent %s\n", GC_m2s (type));
1513 * Sends key exchange message on a tunnel, choosing the best connection.
1514 * Should not be called on loopback tunnels.
1516 * @param t Tunnel on which this message is transmitted.
1517 * @param message Message to send. Function modifies it.
1519 * @return Handle to the message in the connection queue.
1521 static struct CadetConnectionQueue *
1522 send_kx (struct CadetTunnel *t,
1523 const struct GNUNET_MessageHeader *message)
1525 struct CadetConnection *c;
1526 struct GNUNET_CADET_KX *msg;
1527 size_t size = ntohs (message->size);
1528 char cbuf[sizeof (struct GNUNET_CADET_KX) + size];
1533 LOG (GNUNET_ERROR_TYPE_DEBUG, "GMT KX on Tunnel %s\n", GCT_2s (t));
1535 /* Avoid loopback. */
1536 if (GCT_is_loopback (t))
1538 LOG (GNUNET_ERROR_TYPE_DEBUG, " loopback!\n");
1542 type = ntohs (message->type);
1544 /* Even if tunnel is "being destroyed", send anyway.
1545 * Could be a response to a rekey initiated by remote peer,
1546 * who is trying to create a new channel!
1549 /* Must have a connection, or be looking for one. */
1550 if (NULL == t->connection_head)
1552 LOG (GNUNET_ERROR_TYPE_DEBUG, "%s while no connection\n", GC_m2s (type));
1553 if (CADET_TUNNEL_SEARCHING != t->cstate)
1556 GCT_debug (t, GNUNET_ERROR_TYPE_ERROR);
1557 GCP_debug (t->peer, GNUNET_ERROR_TYPE_ERROR);
1562 msg = (struct GNUNET_CADET_KX *) cbuf;
1563 msg->header.type = htons (GNUNET_MESSAGE_TYPE_CADET_KX);
1564 msg->header.size = htons (sizeof (struct GNUNET_CADET_KX) + size);
1565 c = tunnel_get_connection (t);
1568 if (NULL == t->destroy_task
1569 && CADET_TUNNEL_READY == t->cstate)
1572 GCT_debug (t, GNUNET_ERROR_TYPE_ERROR);
1578 case GNUNET_MESSAGE_TYPE_CADET_KX_EPHEMERAL:
1579 GNUNET_assert (NULL == t->ephm_h);
1581 memcpy (&msg[1], message, size);
1583 case GNUNET_MESSAGE_TYPE_CADET_KX_PONG:
1584 GNUNET_assert (NULL == t->pong_h);
1586 memcpy (&msg[1], message, size);
1590 LOG (GNUNET_ERROR_TYPE_DEBUG, "unkown type %s\n", GC_m2s (type));
1594 fwd = GCC_is_origin (t->connection_head->c, GNUNET_YES);
1596 return GCC_send_prebuilt_message (&msg->header, type, 0, c,
1603 * Send the ephemeral key on a tunnel.
1605 * @param t Tunnel on which to send the key.
1608 send_ephemeral (struct CadetTunnel *t)
1610 LOG (GNUNET_ERROR_TYPE_INFO, "===> EPHM for %s\n", GCT_2s (t));
1611 if (NULL != t->ephm_h)
1613 LOG (GNUNET_ERROR_TYPE_INFO, " already queued\n");
1617 kx_msg.sender_status = htonl (t->estate);
1618 kx_msg.iv = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX);
1619 kx_msg.nonce = t->kx_ctx->challenge;
1620 LOG (GNUNET_ERROR_TYPE_DEBUG, " send nonce c %u\n", kx_msg.nonce);
1621 t_encrypt (t, &kx_msg.nonce, &kx_msg.nonce,
1622 ping_encryption_size(), kx_msg.iv, GNUNET_YES);
1623 LOG (GNUNET_ERROR_TYPE_DEBUG, " send nonce e %u\n", kx_msg.nonce);
1624 t->ephm_h = send_kx (t, &kx_msg.header);
1629 * Send a pong message on a tunnel.
1631 * @param t Tunnel on which to send the pong.
1632 * @param challenge Value sent in the ping that we have to send back.
1635 send_pong (struct CadetTunnel *t, uint32_t challenge)
1637 struct GNUNET_CADET_KX_Pong msg;
1639 LOG (GNUNET_ERROR_TYPE_INFO, "===> PONG for %s\n", GCT_2s (t));
1640 if (NULL != t->pong_h)
1642 LOG (GNUNET_ERROR_TYPE_INFO, " already queued\n");
1645 msg.header.size = htons (sizeof (msg));
1646 msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_KX_PONG);
1647 msg.iv = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX);
1648 msg.nonce = challenge;
1649 LOG (GNUNET_ERROR_TYPE_DEBUG, " sending %u\n", msg.nonce);
1650 t_encrypt (t, &msg.nonce, &msg.nonce,
1651 sizeof (msg.nonce), msg.iv, GNUNET_YES);
1652 LOG (GNUNET_ERROR_TYPE_DEBUG, " e sending %u\n", msg.nonce);
1654 t->pong_h = send_kx (t, &msg.header);
1659 * Initiate a rekey with the remote peer.
1661 * @param cls Closure (tunnel).
1662 * @param tc TaskContext.
1665 rekey_tunnel (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
1667 struct CadetTunnel *t = cls;
1669 t->rekey_task = NULL;
1671 LOG (GNUNET_ERROR_TYPE_INFO, "Re-key Tunnel %s\n", GCT_2s (t));
1672 if (NULL != tc && 0 != (GNUNET_SCHEDULER_REASON_SHUTDOWN & tc->reason))
1675 GNUNET_assert (NULL != t->kx_ctx);
1676 struct GNUNET_TIME_Relative duration;
1678 duration = GNUNET_TIME_absolute_get_duration (t->kx_ctx->rekey_start_time);
1679 LOG (GNUNET_ERROR_TYPE_DEBUG, " kx started %s ago\n",
1680 GNUNET_STRINGS_relative_time_to_string (duration, GNUNET_YES));
1682 // FIXME make duration of old keys configurable
1683 if (duration.rel_value_us >= GNUNET_TIME_UNIT_MINUTES.rel_value_us)
1685 LOG (GNUNET_ERROR_TYPE_DEBUG, " deleting old keys\n");
1686 memset (&t->kx_ctx->d_key_old, 0, sizeof (t->kx_ctx->d_key_old));
1687 memset (&t->kx_ctx->e_key_old, 0, sizeof (t->kx_ctx->e_key_old));
1694 case CADET_TUNNEL_KEY_UNINITIALIZED:
1695 GCT_change_estate (t, CADET_TUNNEL_KEY_SENT);
1698 case CADET_TUNNEL_KEY_SENT:
1701 case CADET_TUNNEL_KEY_OK:
1703 * - state should have changed during rekey_iterator
1704 * - task should have been canceled at pong_handle
1707 GCT_change_estate (t, CADET_TUNNEL_KEY_REKEY);
1710 case CADET_TUNNEL_KEY_PING:
1711 case CADET_TUNNEL_KEY_REKEY:
1715 LOG (GNUNET_ERROR_TYPE_DEBUG, "Unexpected state %u\n", t->estate);
1718 // FIXME exponential backoff
1719 struct GNUNET_TIME_Relative delay;
1721 delay = GNUNET_TIME_relative_divide (rekey_period, 16);
1722 delay = GNUNET_TIME_relative_min (delay, REKEY_WAIT);
1723 LOG (GNUNET_ERROR_TYPE_DEBUG, " next call in %s\n",
1724 GNUNET_STRINGS_relative_time_to_string (delay, GNUNET_YES));
1725 t->rekey_task = GNUNET_SCHEDULER_add_delayed (delay, &rekey_tunnel, t);
1730 * Our ephemeral key has changed, create new session key on all tunnels.
1732 * Each tunnel will start the Key Exchange with a random delay between
1733 * 0 and number_of_tunnels*100 milliseconds, so there are 10 key exchanges
1734 * per second, on average.
1736 * @param cls Closure (size of the hashmap).
1737 * @param key Current public key.
1738 * @param value Value in the hash map (tunnel).
1740 * @return #GNUNET_YES, so we should continue to iterate,
1743 rekey_iterator (void *cls,
1744 const struct GNUNET_PeerIdentity *key,
1747 struct CadetTunnel *t = value;
1748 struct GNUNET_TIME_Relative delay;
1749 long n = (long) cls;
1752 if (NULL != t->rekey_task)
1755 if (GNUNET_YES == GCT_is_loopback (t))
1758 r = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK, (uint32_t) n * 100);
1759 delay = GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MILLISECONDS, r);
1760 t->rekey_task = GNUNET_SCHEDULER_add_delayed (delay, &rekey_tunnel, t);
1762 GCT_change_estate (t, CADET_TUNNEL_KEY_REKEY);
1769 * Create a new ephemeral key and key message, schedule next rekeying.
1771 * @param cls Closure (unused).
1772 * @param tc TaskContext.
1775 rekey (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
1777 struct GNUNET_TIME_Absolute time;
1782 if (0 != (GNUNET_SCHEDULER_REASON_SHUTDOWN & tc->reason))
1785 GNUNET_free_non_null (my_ephemeral_key);
1786 my_ephemeral_key = GNUNET_CRYPTO_ecdhe_key_create ();
1788 time = GNUNET_TIME_absolute_get ();
1789 kx_msg.creation_time = GNUNET_TIME_absolute_hton (time);
1790 time = GNUNET_TIME_absolute_add (time, rekey_period);
1791 time = GNUNET_TIME_absolute_add (time, GNUNET_TIME_UNIT_MINUTES);
1792 kx_msg.expiration_time = GNUNET_TIME_absolute_hton (time);
1793 GNUNET_CRYPTO_ecdhe_key_get_public (my_ephemeral_key, &kx_msg.ephemeral_key);
1794 LOG (GNUNET_ERROR_TYPE_INFO, "GLOBAL RE-KEY, NEW EPHM: %s\n",
1795 GNUNET_h2s ((struct GNUNET_HashCode *) &kx_msg.ephemeral_key));
1797 GNUNET_assert (GNUNET_OK ==
1798 GNUNET_CRYPTO_eddsa_sign (my_private_key,
1800 &kx_msg.signature));
1802 n = (long) GNUNET_CONTAINER_multipeermap_size (tunnels);
1803 GNUNET_CONTAINER_multipeermap_iterate (tunnels, &rekey_iterator, (void *) n);
1805 rekey_task = GNUNET_SCHEDULER_add_delayed (rekey_period, &rekey, NULL);
1810 * Called only on shutdown, destroy every tunnel.
1812 * @param cls Closure (unused).
1813 * @param key Current public key.
1814 * @param value Value in the hash map (tunnel).
1816 * @return #GNUNET_YES, so we should continue to iterate,
1819 destroy_iterator (void *cls,
1820 const struct GNUNET_PeerIdentity *key,
1823 struct CadetTunnel *t = value;
1825 LOG (GNUNET_ERROR_TYPE_DEBUG, "GCT_shutdown destroying tunnel at %p\n", t);
1832 * Notify remote peer that we don't know a channel he is talking about,
1833 * probably CHANNEL_DESTROY was missed.
1835 * @param t Tunnel on which to notify.
1836 * @param gid ID of the channel.
1839 send_channel_destroy (struct CadetTunnel *t, unsigned int gid)
1841 struct GNUNET_CADET_ChannelManage msg;
1843 msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_CHANNEL_DESTROY);
1844 msg.header.size = htons (sizeof (msg));
1845 msg.chid = htonl (gid);
1847 LOG (GNUNET_ERROR_TYPE_DEBUG,
1848 "WARNING destroying unknown channel %u on tunnel %s\n",
1850 send_prebuilt_message (&msg.header, t, NULL, GNUNET_YES, NULL, NULL, NULL);
1855 * Demultiplex data per channel and call appropriate channel handler.
1857 * @param t Tunnel on which the data came.
1858 * @param msg Data message.
1859 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
1860 * #GNUNET_YES if message is FWD on the respective channel (loopback)
1861 * #GNUNET_NO if message is BCK on the respective channel (loopback)
1862 * #GNUNET_SYSERR if message on a one-ended channel (remote)
1865 handle_data (struct CadetTunnel *t,
1866 const struct GNUNET_CADET_Data *msg,
1869 struct CadetChannel *ch;
1873 size = ntohs (msg->header.size);
1875 sizeof (struct GNUNET_CADET_Data) +
1876 sizeof (struct GNUNET_MessageHeader))
1881 LOG (GNUNET_ERROR_TYPE_DEBUG, " payload of type %s\n",
1882 GC_m2s (ntohs (msg[1].header.type)));
1885 ch = GCT_get_channel (t, ntohl (msg->chid));
1888 GNUNET_STATISTICS_update (stats, "# data on unknown channel",
1890 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel 0x%X unknown\n",
1892 send_channel_destroy (t, ntohl (msg->chid));
1896 GCCH_handle_data (ch, msg, fwd);
1901 * Demultiplex data ACKs per channel and update appropriate channel buffer info.
1903 * @param t Tunnel on which the DATA ACK came.
1904 * @param msg DATA ACK message.
1905 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
1906 * #GNUNET_YES if message is FWD on the respective channel (loopback)
1907 * #GNUNET_NO if message is BCK on the respective channel (loopback)
1908 * #GNUNET_SYSERR if message on a one-ended channel (remote)
1911 handle_data_ack (struct CadetTunnel *t,
1912 const struct GNUNET_CADET_DataACK *msg,
1915 struct CadetChannel *ch;
1919 size = ntohs (msg->header.size);
1920 if (size != sizeof (struct GNUNET_CADET_DataACK))
1927 ch = GCT_get_channel (t, ntohl (msg->chid));
1930 GNUNET_STATISTICS_update (stats, "# data ack on unknown channel",
1932 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel %u unknown\n",
1937 GCCH_handle_data_ack (ch, msg, fwd);
1942 * Handle channel create.
1944 * @param t Tunnel on which the data came.
1945 * @param msg Data message.
1948 handle_ch_create (struct CadetTunnel *t,
1949 const struct GNUNET_CADET_ChannelCreate *msg)
1951 struct CadetChannel *ch;
1955 size = ntohs (msg->header.size);
1956 if (size != sizeof (struct GNUNET_CADET_ChannelCreate))
1963 ch = GCT_get_channel (t, ntohl (msg->chid));
1964 if (NULL != ch && ! GCT_is_loopback (t))
1966 /* Probably a retransmission, safe to ignore */
1967 LOG (GNUNET_ERROR_TYPE_DEBUG, " already exists...\n");
1969 ch = GCCH_handle_create (t, msg);
1971 GCT_add_channel (t, ch);
1977 * Handle channel NACK: check correctness and call channel handler for NACKs.
1979 * @param t Tunnel on which the NACK came.
1980 * @param msg NACK message.
1983 handle_ch_nack (struct CadetTunnel *t,
1984 const struct GNUNET_CADET_ChannelManage *msg)
1986 struct CadetChannel *ch;
1990 size = ntohs (msg->header.size);
1991 if (size != sizeof (struct GNUNET_CADET_ChannelManage))
1998 ch = GCT_get_channel (t, ntohl (msg->chid));
2001 GNUNET_STATISTICS_update (stats, "# channel NACK on unknown channel",
2003 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel %u unknown\n",
2008 GCCH_handle_nack (ch);
2013 * Handle a CHANNEL ACK (SYNACK/ACK).
2015 * @param t Tunnel on which the CHANNEL ACK came.
2016 * @param msg CHANNEL ACK message.
2017 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
2018 * #GNUNET_YES if message is FWD on the respective channel (loopback)
2019 * #GNUNET_NO if message is BCK on the respective channel (loopback)
2020 * #GNUNET_SYSERR if message on a one-ended channel (remote)
2023 handle_ch_ack (struct CadetTunnel *t,
2024 const struct GNUNET_CADET_ChannelManage *msg,
2027 struct CadetChannel *ch;
2031 size = ntohs (msg->header.size);
2032 if (size != sizeof (struct GNUNET_CADET_ChannelManage))
2039 ch = GCT_get_channel (t, ntohl (msg->chid));
2042 GNUNET_STATISTICS_update (stats, "# channel ack on unknown channel",
2044 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel %u unknown\n",
2049 GCCH_handle_ack (ch, msg, fwd);
2054 * Handle a channel destruction message.
2056 * @param t Tunnel on which the message came.
2057 * @param msg Channel destroy message.
2058 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
2059 * #GNUNET_YES if message is FWD on the respective channel (loopback)
2060 * #GNUNET_NO if message is BCK on the respective channel (loopback)
2061 * #GNUNET_SYSERR if message on a one-ended channel (remote)
2064 handle_ch_destroy (struct CadetTunnel *t,
2065 const struct GNUNET_CADET_ChannelManage *msg,
2068 struct CadetChannel *ch;
2072 size = ntohs (msg->header.size);
2073 if (size != sizeof (struct GNUNET_CADET_ChannelManage))
2080 ch = GCT_get_channel (t, ntohl (msg->chid));
2083 /* Probably a retransmission, safe to ignore */
2087 GCCH_handle_destroy (ch, msg, fwd);
2092 * Create a new Axolotl ephemeral (ratchet) key.
2097 new_ephemeral (struct CadetTunnel *t)
2099 GNUNET_free_non_null (t->ax->DHRs);
2100 t->ax->DHRs = GNUNET_CRYPTO_ecdhe_key_create();
2105 * Free Axolotl data.
2110 destroy_ax (struct CadetTunnel *t)
2115 if (NULL != t->ax->DHRs)
2116 GNUNET_free (t->ax->DHRs);
2117 GNUNET_free (t->ax);
2124 * The peer's ephemeral key has changed: update the symmetrical keys.
2126 * @param t Tunnel this message came on.
2127 * @param msg Key eXchange message.
2130 handle_ephemeral (struct CadetTunnel *t,
2131 const struct GNUNET_CADET_KX_Ephemeral *msg)
2133 LOG (GNUNET_ERROR_TYPE_INFO, "<=== EPHM for %s\n", GCT_2s (t));
2135 if (GNUNET_OK != check_ephemeral (t, msg))
2137 GNUNET_break_op (0);
2141 /* If we get a proper OTR-style ephemeral, fallback to old crypto. */
2145 t->enc_type = CADET_Fallback;
2149 * If the key is different from what we know, derive the new E/D keys.
2150 * Else destroy the rekey ctx (duplicate EPHM after successful KX).
2152 if (0 != memcmp (&t->peers_ephemeral_key, &msg->ephemeral_key,
2153 sizeof (msg->ephemeral_key)))
2155 #if DUMP_KEYS_TO_STDERR
2156 LOG (GNUNET_ERROR_TYPE_INFO, "OLD: %s\n",
2157 GNUNET_h2s ((struct GNUNET_HashCode *) &t->peers_ephemeral_key));
2158 LOG (GNUNET_ERROR_TYPE_INFO, "NEW: %s\n",
2159 GNUNET_h2s ((struct GNUNET_HashCode *) &msg->ephemeral_key));
2161 t->peers_ephemeral_key = msg->ephemeral_key;
2165 if (CADET_TUNNEL_KEY_OK == t->estate)
2167 GCT_change_estate (t, CADET_TUNNEL_KEY_REKEY);
2169 if (NULL != t->rekey_task)
2170 GNUNET_SCHEDULER_cancel (t->rekey_task);
2171 t->rekey_task = GNUNET_SCHEDULER_add_now (rekey_tunnel, t);
2173 if (CADET_TUNNEL_KEY_SENT == t->estate)
2175 LOG (GNUNET_ERROR_TYPE_DEBUG, " our key was sent, sending challenge\n");
2177 GCT_change_estate (t, CADET_TUNNEL_KEY_PING);
2180 if (CADET_TUNNEL_KEY_UNINITIALIZED != ntohl(msg->sender_status))
2184 LOG (GNUNET_ERROR_TYPE_DEBUG, " recv nonce e %u\n", msg->nonce);
2185 t_decrypt (t, &nonce, &msg->nonce, ping_encryption_size (), msg->iv);
2186 LOG (GNUNET_ERROR_TYPE_DEBUG, " recv nonce c %u\n", nonce);
2187 send_pong (t, nonce);
2193 * Peer has answer to our challenge.
2194 * If answer is successful, consider the key exchange finished and clean
2195 * up all related state.
2197 * @param t Tunnel this message came on.
2198 * @param msg Key eXchange Pong message.
2201 handle_pong (struct CadetTunnel *t, const struct GNUNET_CADET_KX_Pong *msg)
2205 LOG (GNUNET_ERROR_TYPE_INFO, "<=== PONG for %s\n", GCT_2s (t));
2206 if (NULL == t->rekey_task)
2208 GNUNET_STATISTICS_update (stats, "# duplicate PONG messages", 1, GNUNET_NO);
2211 if (NULL == t->kx_ctx)
2213 GNUNET_STATISTICS_update (stats, "# stray PONG messages", 1, GNUNET_NO);
2217 t_decrypt (t, &challenge, &msg->nonce, sizeof (uint32_t), msg->iv);
2218 if (challenge != t->kx_ctx->challenge)
2220 LOG (GNUNET_ERROR_TYPE_WARNING, "Wrong PONG challenge on %s\n", GCT_2s (t));
2221 LOG (GNUNET_ERROR_TYPE_DEBUG, "PONG: %u (e: %u). Expected: %u.\n",
2222 challenge, msg->nonce, t->kx_ctx->challenge);
2226 GNUNET_SCHEDULER_cancel (t->rekey_task);
2227 t->rekey_task = NULL;
2229 /* Don't free the old keys right away, but after a delay.
2230 * Rationale: the KX could have happened over a very fast connection,
2231 * with payload traffic still signed with the old key stuck in a slower
2233 * Don't keep the keys longer than 1/4 the rekey period, and no longer than
2237 GCT_change_estate (t, CADET_TUNNEL_KEY_OK);
2249 * WARNING! DANGER! Do not use this if you don't know what you are doing!
2250 * Ask Christian Grothoff, Werner Koch, Dan Bernstein and $GOD!
2252 * Transform a private EdDSA key (peer's key) into a key usable by DH.
2254 * @param k Private EdDSA key to transform.
2256 * @return Private key for EC Diffie-Hellman.
2258 static const struct GNUNET_CRYPTO_EcdhePrivateKey *
2259 get_private_ecdhe_from_eddsa (const struct GNUNET_CRYPTO_EddsaPrivateKey *k)
2261 return (const struct GNUNET_CRYPTO_EcdhePrivateKey *) k;
2266 * WARNING! DANGER! Do not use this if you don't know what you are doing!
2267 * Ask Christian Grothoff, Werner Koch, Dan Bernstein and $GOD!
2269 * Transform a public EdDSA key (peer's key) into a key usable by DH.
2271 * @param k Public EdDSA key to transform (peer's ID).
2273 * @return Public key for EC Diffie-Hellman.
2275 static const struct GNUNET_CRYPTO_EcdhePublicKey *
2276 get_public_ecdhe_from_id (const struct GNUNET_PeerIdentity *id)
2278 return (const struct GNUNET_CRYPTO_EcdhePublicKey *) id;
2283 * Handle Axolotl handshake.
2285 * @param t Tunnel this message came on.
2286 * @param msg Key eXchange Pong message.
2289 handle_kx_ax (struct CadetTunnel *t, const struct GNUNET_CADET_AX_KX *msg)
2291 struct GNUNET_CRYPTO_EcdhePublicKey eph;
2292 struct CadetTunnelAxolotl *ax;
2293 struct GNUNET_HashCode key_material[3];
2294 struct GNUNET_CRYPTO_SymmetricSessionKey keys[5];
2295 const struct GNUNET_CRYPTO_EcdhePublicKey *DHIr;
2296 const struct GNUNET_CRYPTO_EcdhePrivateKey *DHIs;
2297 const char salt[] = "CADET Axolotl salt";
2301 /* Something is wrong if ax is NULL. Whose fault it is? */
2302 GNUNET_break_op (CADET_Fallback == t->enc_type);
2303 GNUNET_break (CADET_Axolotl == t->enc_type);
2308 ax->DHRr = msg->ratchet_key;
2310 GNUNET_CRYPTO_ecdhe_key_get_public (ax->DHRs, &eph);
2311 if (0 != memcmp (&eph, &msg->peers_key, sizeof (eph)))
2317 DHIr = get_public_ecdhe_from_id (GCT_get_destination (t));
2321 GNUNET_CRYPTO_ecc_ecdh (DHIs,
2322 &msg->ephemeral_key,
2324 GNUNET_CRYPTO_ecc_ecdh (ax->DHRs,
2327 GNUNET_CRYPTO_ecc_ecdh (ax->DHRs,
2328 &msg->ephemeral_key,
2332 GNUNET_CRYPTO_kdf (keys, sizeof (keys),
2333 salt, sizeof (salt),
2334 key_material, sizeof (key_material), NULL);
2339 * Demultiplex by message type and call appropriate handler for a message
2340 * towards a channel of a local tunnel.
2342 * @param t Tunnel this message came on.
2343 * @param msgh Message header.
2344 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
2345 * #GNUNET_YES if message is FWD on the respective channel (loopback)
2346 * #GNUNET_NO if message is BCK on the respective channel (loopback)
2347 * #GNUNET_SYSERR if message on a one-ended channel (remote)
2350 handle_decrypted (struct CadetTunnel *t,
2351 const struct GNUNET_MessageHeader *msgh,
2356 type = ntohs (msgh->type);
2357 LOG (GNUNET_ERROR_TYPE_INFO, "<=== %s on %s\n", GC_m2s (type), GCT_2s (t));
2361 case GNUNET_MESSAGE_TYPE_CADET_KEEPALIVE:
2362 /* Do nothing, connection aleady got updated. */
2363 GNUNET_STATISTICS_update (stats, "# keepalives received", 1, GNUNET_NO);
2366 case GNUNET_MESSAGE_TYPE_CADET_DATA:
2367 /* Don't send hop ACK, wait for client to ACK */
2368 handle_data (t, (struct GNUNET_CADET_Data *) msgh, fwd);
2371 case GNUNET_MESSAGE_TYPE_CADET_DATA_ACK:
2372 handle_data_ack (t, (struct GNUNET_CADET_DataACK *) msgh, fwd);
2375 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_CREATE:
2376 handle_ch_create (t, (struct GNUNET_CADET_ChannelCreate *) msgh);
2379 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_NACK:
2380 handle_ch_nack (t, (struct GNUNET_CADET_ChannelManage *) msgh);
2383 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_ACK:
2384 handle_ch_ack (t, (struct GNUNET_CADET_ChannelManage *) msgh, fwd);
2387 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_DESTROY:
2388 handle_ch_destroy (t, (struct GNUNET_CADET_ChannelManage *) msgh, fwd);
2392 GNUNET_break_op (0);
2393 LOG (GNUNET_ERROR_TYPE_WARNING,
2394 "end-to-end message not known (%u)\n",
2395 ntohs (msgh->type));
2396 GCT_debug (t, GNUNET_ERROR_TYPE_WARNING);
2400 /******************************************************************************/
2401 /******************************** API ***********************************/
2402 /******************************************************************************/
2404 * Decrypt old format and demultiplex by message type. Call appropriate handler
2405 * for a message towards a channel of a local tunnel.
2407 * @param t Tunnel this message came on.
2408 * @param msg Message header.
2411 GCT_handle_encrypted (struct CadetTunnel *t,
2412 const struct GNUNET_MessageHeader *msg)
2414 size_t size = ntohs (msg->size);
2415 size_t payload_size;
2418 uint16_t type = ntohs (msg->type);
2419 struct GNUNET_MessageHeader *msgh;
2422 if (GNUNET_MESSAGE_TYPE_CADET_ENCRYPTED == type)
2424 const struct GNUNET_CADET_Encrypted *emsg;
2426 emsg = (struct GNUNET_CADET_Encrypted *) msg;
2427 payload_size = size - sizeof (struct GNUNET_CADET_Encrypted);
2428 decrypted_size = t_decrypt_and_validate (t, cbuf, &emsg[1], payload_size,
2429 emsg->iv, &emsg->hmac);
2431 else if (GNUNET_MESSAGE_TYPE_CADET_AX == type)
2433 const struct GNUNET_CADET_AX *emsg;
2435 emsg = (struct GNUNET_CADET_AX *) msg;
2436 payload_size = size - sizeof (struct GNUNET_CADET_AX);
2437 decrypted_size = t_ax_decrypt_and_validate (t, cbuf, &emsg[1],
2438 payload_size, &emsg->hmac);
2441 if (-1 == decrypted_size)
2443 GNUNET_break_op (0);
2448 while (off < decrypted_size)
2452 msgh = (struct GNUNET_MessageHeader *) &cbuf[off];
2453 msize = ntohs (msgh->size);
2454 if (msize < sizeof (struct GNUNET_MessageHeader))
2456 GNUNET_break_op (0);
2459 handle_decrypted (t, msgh, GNUNET_SYSERR);
2466 * Demultiplex an encapsulated KX message by message type.
2468 * @param t Tunnel on which the message came.
2469 * @param message Payload of KX message.
2472 GCT_handle_kx (struct CadetTunnel *t,
2473 const struct GNUNET_MessageHeader *message)
2477 type = ntohs (message->type);
2478 LOG (GNUNET_ERROR_TYPE_DEBUG, "kx message received: %s\n", GC_m2s (type));
2481 case GNUNET_MESSAGE_TYPE_CADET_KX_EPHEMERAL:
2482 handle_ephemeral (t, (const struct GNUNET_CADET_KX_Ephemeral *) message);
2485 case GNUNET_MESSAGE_TYPE_CADET_KX_PONG:
2486 handle_pong (t, (const struct GNUNET_CADET_KX_Pong *) message);
2489 case GNUNET_MESSAGE_TYPE_CADET_AX_KX:
2490 handle_kx_ax (t, (const struct GNUNET_CADET_AX_KX *) message);
2494 GNUNET_break_op (0);
2495 LOG (GNUNET_ERROR_TYPE_WARNING, "kx message %s unknown\n", GC_m2s (type));
2501 * Initialize the tunnel subsystem.
2503 * @param c Configuration handle.
2504 * @param key ECC private key, to derive all other keys and do crypto.
2507 GCT_init (const struct GNUNET_CONFIGURATION_Handle *c,
2508 const struct GNUNET_CRYPTO_EddsaPrivateKey *key)
2510 int expected_overhead;
2512 LOG (GNUNET_ERROR_TYPE_DEBUG, "init\n");
2514 expected_overhead = 0;
2515 expected_overhead += sizeof (struct GNUNET_CADET_Encrypted);
2516 expected_overhead += sizeof (struct GNUNET_CADET_Data);
2517 expected_overhead += sizeof (struct GNUNET_CADET_ACK);
2518 GNUNET_assert (GNUNET_CONSTANTS_CADET_P2P_OVERHEAD == expected_overhead);
2521 GNUNET_CONFIGURATION_get_value_number (c, "CADET", "DEFAULT_TTL",
2524 GNUNET_log_config_invalid (GNUNET_ERROR_TYPE_WARNING,
2525 "CADET", "DEFAULT_TTL", "USING DEFAULT");
2529 GNUNET_CONFIGURATION_get_value_time (c, "CADET", "REKEY_PERIOD",
2532 rekey_period = GNUNET_TIME_UNIT_DAYS;
2535 my_private_key = key;
2536 ax_identity = get_private_ecdhe_from_eddsa (key);
2538 kx_msg.header.size = htons (sizeof (kx_msg));
2539 kx_msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_KX_EPHEMERAL);
2540 kx_msg.purpose.purpose = htonl (GNUNET_SIGNATURE_PURPOSE_CADET_KX);
2541 kx_msg.purpose.size = htonl (ephemeral_purpose_size ());
2542 kx_msg.origin_identity = my_full_id;
2543 rekey_task = GNUNET_SCHEDULER_add_now (&rekey, NULL);
2545 tunnels = GNUNET_CONTAINER_multipeermap_create (128, GNUNET_YES);
2550 * Shut down the tunnel subsystem.
2555 if (NULL != rekey_task)
2557 GNUNET_SCHEDULER_cancel (rekey_task);
2560 GNUNET_CONTAINER_multipeermap_iterate (tunnels, &destroy_iterator, NULL);
2561 GNUNET_CONTAINER_multipeermap_destroy (tunnels);
2568 * @param destination Peer this tunnel is towards.
2570 struct CadetTunnel *
2571 GCT_new (struct CadetPeer *destination)
2573 struct CadetTunnel *t;
2575 t = GNUNET_new (struct CadetTunnel);
2577 t->peer = destination;
2580 GNUNET_CONTAINER_multipeermap_put (tunnels, GCP_get_id (destination), t,
2581 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_FAST))
2587 t->ax = GNUNET_new (struct CadetTunnelAxolotl);
2593 * Change the tunnel's connection state.
2595 * @param t Tunnel whose connection state to change.
2596 * @param cstate New connection state.
2599 GCT_change_cstate (struct CadetTunnel* t, enum CadetTunnelCState cstate)
2603 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel %s cstate %s => %s\n",
2604 GCP_2s (t->peer), cstate2s (t->cstate), cstate2s (cstate));
2605 if (myid != GCP_get_short_id (t->peer) &&
2606 CADET_TUNNEL_READY != t->cstate &&
2607 CADET_TUNNEL_READY == cstate)
2610 if (CADET_TUNNEL_KEY_OK == t->estate)
2612 LOG (GNUNET_ERROR_TYPE_DEBUG, " cstate triggered send queued data\n");
2613 send_queued_data (t);
2615 else if (CADET_TUNNEL_KEY_UNINITIALIZED == t->estate)
2617 LOG (GNUNET_ERROR_TYPE_DEBUG, " cstate triggered rekey\n");
2618 if (NULL != t->rekey_task)
2619 GNUNET_SCHEDULER_cancel (t->rekey_task);
2621 rekey_tunnel (t, NULL);
2626 if (CADET_TUNNEL_READY == cstate
2627 && CONNECTIONS_PER_TUNNEL <= GCT_count_connections (t))
2629 LOG (GNUNET_ERROR_TYPE_DEBUG, " cstate triggered stop dht\n");
2630 GCP_stop_search (t->peer);
2636 * Change the tunnel encryption state.
2638 * @param t Tunnel whose encryption state to change, or NULL.
2639 * @param state New encryption state.
2642 GCT_change_estate (struct CadetTunnel* t, enum CadetTunnelEState state)
2644 enum CadetTunnelEState old;
2651 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel %s estate was %s\n",
2652 GCP_2s (t->peer), estate2s (old));
2653 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel %s estate is now %s\n",
2654 GCP_2s (t->peer), estate2s (t->estate));
2656 /* Send queued data if enc state changes to OK */
2657 if (myid != GCP_get_short_id (t->peer) &&
2658 CADET_TUNNEL_KEY_OK != old && CADET_TUNNEL_KEY_OK == t->estate)
2660 send_queued_data (t);
2666 * @brief Check if tunnel has too many connections, and remove one if necessary.
2668 * Currently this means the newest connection, unless it is a direct one.
2669 * Implemented as a task to avoid freeing a connection that is in the middle
2670 * of being created/processed.
2672 * @param cls Closure (Tunnel to check).
2673 * @param tc Task context.
2676 trim_connections (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
2678 struct CadetTunnel *t = cls;
2680 t->trim_connections_task = NULL;
2682 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
2685 if (GCT_count_connections (t) > 2 * CONNECTIONS_PER_TUNNEL)
2687 struct CadetTConnection *iter;
2688 struct CadetTConnection *c;
2690 for (c = iter = t->connection_head; NULL != iter; iter = iter->next)
2692 if ((iter->created.abs_value_us > c->created.abs_value_us)
2693 && GNUNET_NO == GCC_is_direct (iter->c))
2700 LOG (GNUNET_ERROR_TYPE_DEBUG, "Too many connections on tunnel %s\n",
2702 LOG (GNUNET_ERROR_TYPE_DEBUG, "Destroying connection %s\n",
2715 * Add a connection to a tunnel.
2718 * @param c Connection.
2721 GCT_add_connection (struct CadetTunnel *t, struct CadetConnection *c)
2723 struct CadetTConnection *aux;
2725 GNUNET_assert (NULL != c);
2727 LOG (GNUNET_ERROR_TYPE_DEBUG, "add connection %s\n", GCC_2s (c));
2728 LOG (GNUNET_ERROR_TYPE_DEBUG, " to tunnel %s\n", GCT_2s (t));
2729 for (aux = t->connection_head; aux != NULL; aux = aux->next)
2733 aux = GNUNET_new (struct CadetTConnection);
2735 aux->created = GNUNET_TIME_absolute_get ();
2737 GNUNET_CONTAINER_DLL_insert (t->connection_head, t->connection_tail, aux);
2739 if (CADET_TUNNEL_SEARCHING == t->cstate)
2740 GCT_change_estate (t, CADET_TUNNEL_WAITING);
2742 if (NULL != t->trim_connections_task)
2743 t->trim_connections_task = GNUNET_SCHEDULER_add_now (&trim_connections, t);
2748 * Remove a connection from a tunnel.
2751 * @param c Connection.
2754 GCT_remove_connection (struct CadetTunnel *t,
2755 struct CadetConnection *c)
2757 struct CadetTConnection *aux;
2758 struct CadetTConnection *next;
2761 LOG (GNUNET_ERROR_TYPE_DEBUG, "Removing connection %s from tunnel %s\n",
2762 GCC_2s (c), GCT_2s (t));
2763 for (aux = t->connection_head; aux != NULL; aux = next)
2768 GNUNET_CONTAINER_DLL_remove (t->connection_head, t->connection_tail, aux);
2773 conns = GCT_count_connections (t);
2775 && NULL == t->destroy_task
2776 && CADET_TUNNEL_SHUTDOWN != t->cstate
2777 && GNUNET_NO == shutting_down)
2779 if (0 == GCT_count_any_connections (t))
2780 GCT_change_cstate (t, CADET_TUNNEL_SEARCHING);
2782 GCT_change_cstate (t, CADET_TUNNEL_WAITING);
2785 /* Start new connections if needed */
2786 if (CONNECTIONS_PER_TUNNEL > conns
2787 && NULL == t->destroy_task
2788 && CADET_TUNNEL_SHUTDOWN != t->cstate
2789 && GNUNET_NO == shutting_down)
2791 LOG (GNUNET_ERROR_TYPE_DEBUG, " too few connections, getting new ones\n");
2792 GCP_connect (t->peer); /* Will change cstate to WAITING when possible */
2796 /* If not marked as ready, no change is needed */
2797 if (CADET_TUNNEL_READY != t->cstate)
2800 /* Check if any connection is ready to maintain cstate */
2801 for (aux = t->connection_head; aux != NULL; aux = aux->next)
2802 if (CADET_CONNECTION_READY == GCC_get_state (aux->c))
2808 * Add a channel to a tunnel.
2811 * @param ch Channel.
2814 GCT_add_channel (struct CadetTunnel *t, struct CadetChannel *ch)
2816 struct CadetTChannel *aux;
2818 GNUNET_assert (NULL != ch);
2820 LOG (GNUNET_ERROR_TYPE_DEBUG, "Adding channel %p to tunnel %p\n", ch, t);
2822 for (aux = t->channel_head; aux != NULL; aux = aux->next)
2824 LOG (GNUNET_ERROR_TYPE_DEBUG, " already there %p\n", aux->ch);
2829 aux = GNUNET_new (struct CadetTChannel);
2831 LOG (GNUNET_ERROR_TYPE_DEBUG, " adding %p to %p\n", aux, t->channel_head);
2832 GNUNET_CONTAINER_DLL_insert_tail (t->channel_head, t->channel_tail, aux);
2834 if (NULL != t->destroy_task)
2836 GNUNET_SCHEDULER_cancel (t->destroy_task);
2837 t->destroy_task = NULL;
2838 LOG (GNUNET_ERROR_TYPE_DEBUG, " undo destroy!\n");
2844 * Remove a channel from a tunnel.
2847 * @param ch Channel.
2850 GCT_remove_channel (struct CadetTunnel *t, struct CadetChannel *ch)
2852 struct CadetTChannel *aux;
2854 LOG (GNUNET_ERROR_TYPE_DEBUG, "Removing channel %p from tunnel %p\n", ch, t);
2855 for (aux = t->channel_head; aux != NULL; aux = aux->next)
2859 LOG (GNUNET_ERROR_TYPE_DEBUG, " found! %s\n", GCCH_2s (ch));
2860 GNUNET_CONTAINER_DLL_remove (t->channel_head, t->channel_tail, aux);
2869 * Search for a channel by global ID.
2871 * @param t Tunnel containing the channel.
2872 * @param chid Public channel number.
2874 * @return channel handler, NULL if doesn't exist
2876 struct CadetChannel *
2877 GCT_get_channel (struct CadetTunnel *t, CADET_ChannelNumber chid)
2879 struct CadetTChannel *iter;
2884 for (iter = t->channel_head; NULL != iter; iter = iter->next)
2886 if (GCCH_get_id (iter->ch) == chid)
2890 return NULL == iter ? NULL : iter->ch;
2895 * @brief Destroy a tunnel and free all resources.
2897 * Should only be called a while after the tunnel has been marked as destroyed,
2898 * in case there is a new channel added to the same peer shortly after marking
2899 * the tunnel. This way we avoid a new public key handshake.
2901 * @param cls Closure (tunnel to destroy).
2902 * @param tc Task context.
2905 delayed_destroy (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
2907 struct CadetTunnel *t = cls;
2908 struct CadetTConnection *iter;
2910 LOG (GNUNET_ERROR_TYPE_DEBUG, "delayed destroying tunnel %p\n", t);
2911 if (0 != (GNUNET_SCHEDULER_REASON_SHUTDOWN & tc->reason))
2913 LOG (GNUNET_ERROR_TYPE_WARNING,
2914 "Not destroying tunnel, due to shutdown. "
2915 "Tunnel at %p should have been freed by GCT_shutdown\n", t);
2918 t->destroy_task = NULL;
2919 t->cstate = CADET_TUNNEL_SHUTDOWN;
2921 for (iter = t->connection_head; NULL != iter; iter = iter->next)
2923 GCC_send_destroy (iter->c);
2930 * Tunnel is empty: destroy it.
2932 * Notifies all connections about the destruction.
2934 * @param t Tunnel to destroy.
2937 GCT_destroy_empty (struct CadetTunnel *t)
2939 if (GNUNET_YES == shutting_down)
2940 return; /* Will be destroyed immediately anyway */
2942 if (NULL != t->destroy_task)
2944 LOG (GNUNET_ERROR_TYPE_WARNING,
2945 "Tunnel %s is already scheduled for destruction. Tunnel debug dump:\n",
2947 GCT_debug (t, GNUNET_ERROR_TYPE_WARNING);
2949 /* should never happen, tunnel can only become empty once, and the
2950 * task identifier should be NO_TASK (cleaned when the tunnel was created
2951 * or became un-empty)
2956 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel %s empty: scheduling destruction\n",
2959 // FIXME make delay a config option
2960 t->destroy_task = GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_MINUTES,
2961 &delayed_destroy, t);
2962 LOG (GNUNET_ERROR_TYPE_DEBUG, "Scheduled destroy of %p as %llu\n",
2963 t, t->destroy_task);
2968 * Destroy tunnel if empty (no more channels).
2970 * @param t Tunnel to destroy if empty.
2973 GCT_destroy_if_empty (struct CadetTunnel *t)
2975 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel %s destroy if empty\n", GCT_2s (t));
2976 if (0 < GCT_count_channels (t))
2979 GCT_destroy_empty (t);
2984 * Destroy the tunnel.
2986 * This function does not generate any warning traffic to clients or peers.
2989 * Cancel messages belonging to this tunnel queued to neighbors.
2990 * Free any allocated resources linked to the tunnel.
2992 * @param t The tunnel to destroy.
2995 GCT_destroy (struct CadetTunnel *t)
2997 struct CadetTConnection *iter_c;
2998 struct CadetTConnection *next_c;
2999 struct CadetTChannel *iter_ch;
3000 struct CadetTChannel *next_ch;
3005 LOG (GNUNET_ERROR_TYPE_DEBUG, "destroying tunnel %s\n", GCP_2s (t->peer));
3007 GNUNET_break (GNUNET_YES ==
3008 GNUNET_CONTAINER_multipeermap_remove (tunnels,
3009 GCP_get_id (t->peer), t));
3011 for (iter_c = t->connection_head; NULL != iter_c; iter_c = next_c)
3013 next_c = iter_c->next;
3014 GCC_destroy (iter_c->c);
3016 for (iter_ch = t->channel_head; NULL != iter_ch; iter_ch = next_ch)
3018 next_ch = iter_ch->next;
3019 GCCH_destroy (iter_ch->ch);
3020 /* Should only happen on shutdown, but it's ok. */
3023 if (NULL != t->destroy_task)
3025 LOG (GNUNET_ERROR_TYPE_DEBUG, "cancelling dest: %llX\n", t->destroy_task);
3026 GNUNET_SCHEDULER_cancel (t->destroy_task);
3027 t->destroy_task = NULL;
3030 if (NULL != t->trim_connections_task)
3032 LOG (GNUNET_ERROR_TYPE_DEBUG, "cancelling trim: %llX\n",
3033 t->trim_connections_task);
3034 GNUNET_SCHEDULER_cancel (t->trim_connections_task);
3035 t->trim_connections_task = NULL;
3038 GNUNET_STATISTICS_update (stats, "# tunnels", -1, GNUNET_NO);
3039 GCP_set_tunnel (t->peer, NULL);
3041 if (NULL != t->rekey_task)
3043 GNUNET_SCHEDULER_cancel (t->rekey_task);
3044 t->rekey_task = NULL;
3046 if (NULL != t->kx_ctx)
3048 if (NULL != t->kx_ctx->finish_task)
3049 GNUNET_SCHEDULER_cancel (t->kx_ctx->finish_task);
3050 GNUNET_free (t->kx_ctx);
3061 * @brief Use the given path for the tunnel.
3062 * Update the next and prev hops (and RCs).
3063 * (Re)start the path refresh in case the tunnel is locally owned.
3065 * @param t Tunnel to update.
3066 * @param p Path to use.
3068 * @return Connection created.
3070 struct CadetConnection *
3071 GCT_use_path (struct CadetTunnel *t, struct CadetPeerPath *p)
3073 struct CadetConnection *c;
3074 struct GNUNET_CADET_Hash cid;
3075 unsigned int own_pos;
3077 if (NULL == t || NULL == p)
3083 if (CADET_TUNNEL_SHUTDOWN == t->cstate)
3089 for (own_pos = 0; own_pos < p->length; own_pos++)
3091 if (p->peers[own_pos] == myid)
3094 if (own_pos >= p->length)
3096 GNUNET_break_op (0);
3100 GNUNET_CRYPTO_random_block (GNUNET_CRYPTO_QUALITY_NONCE, &cid, sizeof (cid));
3101 c = GCC_new (&cid, t, p, own_pos);
3104 /* Path was flawed */
3107 GCT_add_connection (t, c);
3113 * Count all created connections of a tunnel. Not necessarily ready connections!
3115 * @param t Tunnel on which to count.
3117 * @return Number of connections created, either being established or ready.
3120 GCT_count_any_connections (struct CadetTunnel *t)
3122 struct CadetTConnection *iter;
3128 for (count = 0, iter = t->connection_head; NULL != iter; iter = iter->next)
3136 * Count established (ready) connections of a tunnel.
3138 * @param t Tunnel on which to count.
3140 * @return Number of connections.
3143 GCT_count_connections (struct CadetTunnel *t)
3145 struct CadetTConnection *iter;
3151 for (count = 0, iter = t->connection_head; NULL != iter; iter = iter->next)
3152 if (CADET_CONNECTION_READY == GCC_get_state (iter->c))
3160 * Count channels of a tunnel.
3162 * @param t Tunnel on which to count.
3164 * @return Number of channels.
3167 GCT_count_channels (struct CadetTunnel *t)
3169 struct CadetTChannel *iter;
3172 for (count = 0, iter = t->channel_head;
3174 iter = iter->next, count++) /* skip */;
3181 * Get the connectivity state of a tunnel.
3185 * @return Tunnel's connectivity state.
3187 enum CadetTunnelCState
3188 GCT_get_cstate (struct CadetTunnel *t)
3193 return (enum CadetTunnelCState) -1;
3200 * Get the encryption state of a tunnel.
3204 * @return Tunnel's encryption state.
3206 enum CadetTunnelEState
3207 GCT_get_estate (struct CadetTunnel *t)
3212 return (enum CadetTunnelEState) -1;
3218 * Get the maximum buffer space for a tunnel towards a local client.
3222 * @return Biggest buffer space offered by any channel in the tunnel.
3225 GCT_get_channels_buffer (struct CadetTunnel *t)
3227 struct CadetTChannel *iter;
3228 unsigned int buffer;
3229 unsigned int ch_buf;
3231 if (NULL == t->channel_head)
3233 /* Probably getting buffer for a channel create/handshake. */
3234 LOG (GNUNET_ERROR_TYPE_DEBUG, " no channels, allow max\n");
3239 for (iter = t->channel_head; NULL != iter; iter = iter->next)
3241 ch_buf = get_channel_buffer (iter);
3242 if (ch_buf > buffer)
3250 * Get the total buffer space for a tunnel for P2P traffic.
3254 * @return Buffer space offered by all connections in the tunnel.
3257 GCT_get_connections_buffer (struct CadetTunnel *t)
3259 struct CadetTConnection *iter;
3260 unsigned int buffer;
3262 if (GNUNET_NO == is_ready (t))
3264 if (count_queued_data (t) > 3)
3271 for (iter = t->connection_head; NULL != iter; iter = iter->next)
3273 if (GCC_get_state (iter->c) != CADET_CONNECTION_READY)
3277 buffer += get_connection_buffer (iter);
3285 * Get the tunnel's destination.
3289 * @return ID of the destination peer.
3291 const struct GNUNET_PeerIdentity *
3292 GCT_get_destination (struct CadetTunnel *t)
3294 return GCP_get_id (t->peer);
3299 * Get the tunnel's next free global channel ID.
3303 * @return GID of a channel free to use.
3306 GCT_get_next_chid (struct CadetTunnel *t)
3308 CADET_ChannelNumber chid;
3309 CADET_ChannelNumber mask;
3312 /* Set bit 30 depending on the ID relationship. Bit 31 is always 0 for GID.
3313 * If our ID is bigger or loopback tunnel, start at 0, bit 30 = 0
3314 * If peer's ID is bigger, start at 0x4... bit 30 = 1
3316 result = GNUNET_CRYPTO_cmp_peer_identity (&my_full_id, GCP_get_id (t->peer));
3321 t->next_chid |= mask;
3323 while (NULL != GCT_get_channel (t, t->next_chid))
3325 LOG (GNUNET_ERROR_TYPE_DEBUG, "Channel %u exists...\n", t->next_chid);
3326 t->next_chid = (t->next_chid + 1) & ~GNUNET_CADET_LOCAL_CHANNEL_ID_CLI;
3327 t->next_chid |= mask;
3329 chid = t->next_chid;
3330 t->next_chid = (t->next_chid + 1) & ~GNUNET_CADET_LOCAL_CHANNEL_ID_CLI;
3331 t->next_chid |= mask;
3338 * Send ACK on one or more channels due to buffer in connections.
3340 * @param t Channel which has some free buffer space.
3343 GCT_unchoke_channels (struct CadetTunnel *t)
3345 struct CadetTChannel *iter;
3346 unsigned int buffer;
3347 unsigned int channels = GCT_count_channels (t);
3348 unsigned int choked_n;
3349 struct CadetChannel *choked[channels];
3351 LOG (GNUNET_ERROR_TYPE_DEBUG, "GCT_unchoke_channels on %s\n", GCT_2s (t));
3352 LOG (GNUNET_ERROR_TYPE_DEBUG, " head: %p\n", t->channel_head);
3353 if (NULL != t->channel_head)
3354 LOG (GNUNET_ERROR_TYPE_DEBUG, " head ch: %p\n", t->channel_head->ch);
3356 /* Get buffer space */
3357 buffer = GCT_get_connections_buffer (t);
3363 /* Count and remember choked channels */
3365 for (iter = t->channel_head; NULL != iter; iter = iter->next)
3367 if (GNUNET_NO == get_channel_allowed (iter))
3369 choked[choked_n++] = iter->ch;
3373 /* Unchoke random channels */
3374 while (0 < buffer && 0 < choked_n)
3376 unsigned int r = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK,
3378 GCCH_allow_client (choked[r], GCCH_is_origin (choked[r], GNUNET_YES));
3381 choked[r] = choked[choked_n];
3387 * Send ACK on one or more connections due to buffer space to the client.
3389 * Iterates all connections of the tunnel and sends ACKs appropriately.
3394 GCT_send_connection_acks (struct CadetTunnel *t)
3396 struct CadetTConnection *iter;
3399 uint32_t allow_per_connection;
3401 unsigned int buffer;
3403 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel send connection ACKs on %s\n",
3412 if (CADET_TUNNEL_READY != t->cstate)
3415 buffer = GCT_get_channels_buffer (t);
3416 LOG (GNUNET_ERROR_TYPE_DEBUG, " buffer %u\n", buffer);
3418 /* Count connections, how many messages are already allowed */
3419 cs = GCT_count_connections (t);
3420 for (allowed = 0, iter = t->connection_head; NULL != iter; iter = iter->next)
3422 allowed += get_connection_allowed (iter);
3424 LOG (GNUNET_ERROR_TYPE_DEBUG, " allowed %u\n", allowed);
3426 /* Make sure there is no overflow */
3427 if (allowed > buffer)
3430 /* Authorize connections to send more data */
3431 to_allow = buffer - allowed;
3433 for (iter = t->connection_head;
3434 NULL != iter && to_allow > 0;
3437 if (CADET_CONNECTION_READY != GCC_get_state (iter->c)
3438 || get_connection_allowed (iter) > 64 / 3)
3442 allow_per_connection = to_allow/cs;
3443 to_allow -= allow_per_connection;
3445 GCC_allow (iter->c, allow_per_connection,
3446 GCC_is_origin (iter->c, GNUNET_NO));
3451 /* Since we don't allow if it's allowed to send 64/3, this can happen. */
3452 LOG (GNUNET_ERROR_TYPE_DEBUG, " reminding to_allow: %u\n", to_allow);
3458 * Cancel a previously sent message while it's in the queue.
3460 * ONLY can be called before the continuation given to the send function
3461 * is called. Once the continuation is called, the message is no longer in the
3464 * @param q Handle to the queue.
3467 GCT_cancel (struct CadetTunnelQueue *q)
3472 /* tun_message_sent() will be called and free q */
3474 else if (NULL != q->tqd)
3476 unqueue_data (q->tqd);
3478 if (NULL != q->cont)
3479 q->cont (q->cont_cls, NULL, q, 0, 0);
3490 * Sends an already built message on a tunnel, encrypting it and
3491 * choosing the best connection if not provided.
3493 * @param message Message to send. Function modifies it.
3494 * @param t Tunnel on which this message is transmitted.
3495 * @param c Connection to use (autoselect if NULL).
3496 * @param force Force the tunnel to take the message (buffer overfill).
3497 * @param cont Continuation to call once message is really sent.
3498 * @param cont_cls Closure for @c cont.
3500 * @return Handle to cancel message. NULL if @c cont is NULL.
3502 struct CadetTunnelQueue *
3503 GCT_send_prebuilt_message (const struct GNUNET_MessageHeader *message,
3504 struct CadetTunnel *t, struct CadetConnection *c,
3505 int force, GCT_sent cont, void *cont_cls)
3507 return send_prebuilt_message (message, t, c, force, cont, cont_cls, NULL);
3511 * Sends an already built and encrypted message on a tunnel, choosing the best
3512 * connection. Useful for re-queueing messages queued on a destroyed connection.
3514 * @param message Message to send. Function modifies it.
3515 * @param t Tunnel on which this message is transmitted.
3518 GCT_resend_message (const struct GNUNET_MessageHeader *message,
3519 struct CadetTunnel *t)
3521 struct CadetConnection *c;
3524 c = tunnel_get_connection (t);
3527 /* TODO queue in tunnel, marked as encrypted */
3528 LOG (GNUNET_ERROR_TYPE_DEBUG, "No connection available, dropping.\n");
3531 fwd = GCC_is_origin (c, GNUNET_YES);
3532 GNUNET_break (NULL == GCC_send_prebuilt_message (message, 0, 0, c, fwd,
3533 GNUNET_YES, NULL, NULL));
3538 * Is the tunnel directed towards the local peer?
3542 * @return #GNUNET_YES if it is loopback.
3545 GCT_is_loopback (const struct CadetTunnel *t)
3547 return (myid == GCP_get_short_id (t->peer));
3552 * Is the tunnel this path already?
3557 * @return #GNUNET_YES a connection uses this path.
3560 GCT_is_path_used (const struct CadetTunnel *t, const struct CadetPeerPath *p)
3562 struct CadetTConnection *iter;
3564 for (iter = t->connection_head; NULL != iter; iter = iter->next)
3565 if (path_equivalent (GCC_get_path (iter->c), p))
3573 * Get a cost of a path for a tunnel considering existing connections.
3576 * @param path Candidate path.
3578 * @return Cost of the path (path length + number of overlapping nodes)
3581 GCT_get_path_cost (const struct CadetTunnel *t,
3582 const struct CadetPeerPath *path)
3584 struct CadetTConnection *iter;
3585 const struct CadetPeerPath *aux;
3586 unsigned int overlap;
3594 GNUNET_assert (NULL != t);
3596 for (i = 0; i < path->length; i++)
3598 for (iter = t->connection_head; NULL != iter; iter = iter->next)
3600 aux = GCC_get_path (iter->c);
3604 for (j = 0; j < aux->length; j++)
3606 if (path->peers[i] == aux->peers[j])
3614 return path->length + overlap;
3619 * Get the static string for the peer this tunnel is directed.
3623 * @return Static string the destination peer's ID.
3626 GCT_2s (const struct CadetTunnel *t)
3631 return GCP_2s (t->peer);
3635 /******************************************************************************/
3636 /***************************** INFO/DEBUG *******************************/
3637 /******************************************************************************/
3640 * Log all possible info about the tunnel state.
3642 * @param t Tunnel to debug.
3643 * @param level Debug level to use.
3646 GCT_debug (const struct CadetTunnel *t, enum GNUNET_ErrorType level)
3648 struct CadetTChannel *iterch;
3649 struct CadetTConnection *iterc;
3652 do_log = GNUNET_get_log_call_status (level & (~GNUNET_ERROR_TYPE_BULK),
3654 __FILE__, __FUNCTION__, __LINE__);
3658 LOG2 (level, "TTT DEBUG TUNNEL TOWARDS %s\n", GCT_2s (t));
3659 LOG2 (level, "TTT cstate %s, estate %s\n",
3660 cstate2s (t->cstate), estate2s (t->estate));
3661 LOG2 (level, "TTT kx_ctx %p, rekey_task %u, finish task %u\n",
3662 t->kx_ctx, t->rekey_task, t->kx_ctx ? t->kx_ctx->finish_task : 0);
3663 #if DUMP_KEYS_TO_STDERR
3664 LOG2 (level, "TTT my EPHM\t %s\n",
3665 GNUNET_h2s ((struct GNUNET_HashCode *) &kx_msg.ephemeral_key));
3666 LOG2 (level, "TTT peers EPHM:\t %s\n",
3667 GNUNET_h2s ((struct GNUNET_HashCode *) &t->peers_ephemeral_key));
3668 LOG2 (level, "TTT ENC key:\t %s\n",
3669 GNUNET_h2s ((struct GNUNET_HashCode *) &t->e_key));
3670 LOG2 (level, "TTT DEC key:\t %s\n",
3671 GNUNET_h2s ((struct GNUNET_HashCode *) &t->d_key));
3674 LOG2 (level, "TTT OLD ENC key:\t %s\n",
3675 GNUNET_h2s ((struct GNUNET_HashCode *) &t->kx_ctx->e_key_old));
3676 LOG2 (level, "TTT OLD DEC key:\t %s\n",
3677 GNUNET_h2s ((struct GNUNET_HashCode *) &t->kx_ctx->d_key_old));
3680 LOG2 (level, "TTT tq_head %p, tq_tail %p\n", t->tq_head, t->tq_tail);
3681 LOG2 (level, "TTT destroy %u\n", t->destroy_task);
3683 LOG2 (level, "TTT channels:\n");
3684 for (iterch = t->channel_head; NULL != iterch; iterch = iterch->next)
3686 LOG2 (level, "TTT - %s\n", GCCH_2s (iterch->ch));
3689 LOG2 (level, "TTT connections:\n");
3690 for (iterc = t->connection_head; NULL != iterc; iterc = iterc->next)
3692 GCC_debug (iterc->c, level);
3695 LOG2 (level, "TTT DEBUG TUNNEL END\n");
3700 * Iterate all tunnels.
3702 * @param iter Iterator.
3703 * @param cls Closure for @c iter.
3706 GCT_iterate_all (GNUNET_CONTAINER_PeerMapIterator iter, void *cls)
3708 GNUNET_CONTAINER_multipeermap_iterate (tunnels, iter, cls);
3713 * Count all tunnels.
3715 * @return Number of tunnels to remote peers kept by this peer.
3718 GCT_count_all (void)
3720 return GNUNET_CONTAINER_multipeermap_size (tunnels);
3725 * Iterate all connections of a tunnel.
3727 * @param t Tunnel whose connections to iterate.
3728 * @param iter Iterator.
3729 * @param cls Closure for @c iter.
3732 GCT_iterate_connections (struct CadetTunnel *t, GCT_conn_iter iter, void *cls)
3734 struct CadetTConnection *ct;
3736 for (ct = t->connection_head; NULL != ct; ct = ct->next)
3742 * Iterate all channels of a tunnel.
3744 * @param t Tunnel whose channels to iterate.
3745 * @param iter Iterator.
3746 * @param cls Closure for @c iter.
3749 GCT_iterate_channels (struct CadetTunnel *t, GCT_chan_iter iter, void *cls)
3751 struct CadetTChannel *cht;
3753 for (cht = t->channel_head; NULL != cht; cht = cht->next)
3754 iter (cls, cht->ch);