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 struct GNUNET_CRYPTO_EcdhePrivateKey *ax_identity;
462 * Own Axolotl public key.
464 static struct GNUNET_CRYPTO_EcdhePrivateKey *ax_key;
467 * Own OTR ephemeral private key.
469 static struct GNUNET_CRYPTO_EcdhePrivateKey *my_ephemeral_key;
472 * Cached message used to perform a key exchange.
474 static struct GNUNET_CADET_KX_Ephemeral kx_msg;
477 * Task to generate a new ephemeral key.
479 static struct GNUNET_SCHEDULER_Task * rekey_task;
484 static struct GNUNET_TIME_Relative rekey_period;
487 /******************************************************************************/
488 /******************************** STATIC ***********************************/
489 /******************************************************************************/
492 * Get string description for tunnel connectivity state.
494 * @param cs Tunnel state.
496 * @return String representation.
499 cstate2s (enum CadetTunnelCState cs)
505 case CADET_TUNNEL_NEW:
506 return "CADET_TUNNEL_NEW";
507 case CADET_TUNNEL_SEARCHING:
508 return "CADET_TUNNEL_SEARCHING";
509 case CADET_TUNNEL_WAITING:
510 return "CADET_TUNNEL_WAITING";
511 case CADET_TUNNEL_READY:
512 return "CADET_TUNNEL_READY";
513 case CADET_TUNNEL_SHUTDOWN:
514 return "CADET_TUNNEL_SHUTDOWN";
516 SPRINTF (buf, "%u (UNKNOWN STATE)", cs);
524 * Get string description for tunnel encryption state.
526 * @param es Tunnel state.
528 * @return String representation.
531 estate2s (enum CadetTunnelEState es)
537 case CADET_TUNNEL_KEY_UNINITIALIZED:
538 return "CADET_TUNNEL_KEY_UNINITIALIZED";
539 case CADET_TUNNEL_KEY_SENT:
540 return "CADET_TUNNEL_KEY_SENT";
541 case CADET_TUNNEL_KEY_PING:
542 return "CADET_TUNNEL_KEY_PING";
543 case CADET_TUNNEL_KEY_OK:
544 return "CADET_TUNNEL_KEY_OK";
545 case CADET_TUNNEL_KEY_REKEY:
546 return "CADET_TUNNEL_KEY_REKEY";
548 SPRINTF (buf, "%u (UNKNOWN STATE)", es);
556 * @brief Check if tunnel is ready to send traffic.
558 * Tunnel must be connected and with encryption correctly set up.
560 * @param t Tunnel to check.
562 * @return #GNUNET_YES if ready, #GNUNET_NO otherwise
565 is_ready (struct CadetTunnel *t)
569 GCT_debug (t, GNUNET_ERROR_TYPE_DEBUG);
570 ready = CADET_TUNNEL_READY == t->cstate
571 && (CADET_TUNNEL_KEY_OK == t->estate
572 || CADET_TUNNEL_KEY_REKEY == t->estate);
573 ready = ready || GCT_is_loopback (t);
579 * Check if a key is invalid (NULL pointer or all 0)
581 * @param key Key to check.
583 * @return #GNUNET_YES if key is null, #GNUNET_NO if exists and is not 0.
586 is_key_null (struct GNUNET_CRYPTO_SymmetricSessionKey *key)
588 struct GNUNET_CRYPTO_SymmetricSessionKey null_key;
593 memset (&null_key, 0, sizeof (null_key));
594 if (0 == memcmp (key, &null_key, sizeof (null_key)))
601 * Ephemeral key message purpose size.
603 * @return Size of the part of the ephemeral key message that must be signed.
606 ephemeral_purpose_size (void)
608 return sizeof (struct GNUNET_CRYPTO_EccSignaturePurpose) +
609 sizeof (struct GNUNET_TIME_AbsoluteNBO) +
610 sizeof (struct GNUNET_TIME_AbsoluteNBO) +
611 sizeof (struct GNUNET_CRYPTO_EcdhePublicKey) +
612 sizeof (struct GNUNET_PeerIdentity);
617 * Size of the encrypted part of a ping message.
619 * @return Size of the encrypted part of a ping message.
622 ping_encryption_size (void)
624 return sizeof (uint32_t);
629 * Get the channel's buffer. ONLY FOR NON-LOOPBACK CHANNELS!!
631 * @param tch Tunnel's channel handle.
633 * @return Amount of messages the channel can still buffer towards the client.
636 get_channel_buffer (const struct CadetTChannel *tch)
640 /* If channel is incoming, is terminal in the FWD direction and fwd is YES */
641 fwd = GCCH_is_terminal (tch->ch, GNUNET_YES);
643 return GCCH_get_buffer (tch->ch, fwd);
648 * Get the channel's allowance status.
650 * @param tch Tunnel's channel handle.
652 * @return #GNUNET_YES if we allowed the client to send data to us.
655 get_channel_allowed (const struct CadetTChannel *tch)
659 /* If channel is outgoing, is origin in the FWD direction and fwd is YES */
660 fwd = GCCH_is_origin (tch->ch, GNUNET_YES);
662 return GCCH_get_allowed (tch->ch, fwd);
667 * Get the connection's buffer.
669 * @param tc Tunnel's connection handle.
671 * @return Amount of messages the connection can still buffer.
674 get_connection_buffer (const struct CadetTConnection *tc)
678 /* If connection is outgoing, is origin in the FWD direction and fwd is YES */
679 fwd = GCC_is_origin (tc->c, GNUNET_YES);
681 return GCC_get_buffer (tc->c, fwd);
686 * Get the connection's allowance.
688 * @param tc Tunnel's connection handle.
690 * @return Amount of messages we have allowed the next peer to send us.
693 get_connection_allowed (const struct CadetTConnection *tc)
697 /* If connection is outgoing, is origin in the FWD direction and fwd is YES */
698 fwd = GCC_is_origin (tc->c, GNUNET_YES);
700 return GCC_get_allowed (tc->c, fwd);
705 * Check that a ephemeral key message s well formed and correctly signed.
707 * @param t Tunnel on which the message came.
708 * @param msg The ephemeral key message.
710 * @return GNUNET_OK if message is fine, GNUNET_SYSERR otherwise.
713 check_ephemeral (struct CadetTunnel *t,
714 const struct GNUNET_CADET_KX_Ephemeral *msg)
716 /* Check message size */
717 if (ntohs (msg->header.size) != sizeof (struct GNUNET_CADET_KX_Ephemeral))
718 return GNUNET_SYSERR;
720 /* Check signature size */
721 if (ntohl (msg->purpose.size) != ephemeral_purpose_size ())
722 return GNUNET_SYSERR;
725 if (0 != memcmp (&msg->origin_identity,
726 GCP_get_id (t->peer),
727 sizeof (struct GNUNET_PeerIdentity)))
728 return GNUNET_SYSERR;
730 /* Check signature */
732 GNUNET_CRYPTO_eddsa_verify (GNUNET_SIGNATURE_PURPOSE_CADET_KX,
735 &msg->origin_identity.public_key))
736 return GNUNET_SYSERR;
743 * Select the best key to use for encryption (send), based on KX status.
745 * Normally, return the current key. If there is a KX in progress and the old
746 * key is fresh enough, return the old key.
748 * @param t Tunnel to choose the key from.
750 * @return The optimal key to encrypt/hmac outgoing traffic.
752 static const struct GNUNET_CRYPTO_SymmetricSessionKey *
753 select_key (const struct CadetTunnel *t)
755 const struct GNUNET_CRYPTO_SymmetricSessionKey *key;
757 if (NULL != t->kx_ctx
758 && NULL == t->kx_ctx->finish_task)
760 struct GNUNET_TIME_Relative age;
762 age = GNUNET_TIME_absolute_get_duration (t->kx_ctx->rekey_start_time);
763 LOG (GNUNET_ERROR_TYPE_DEBUG,
764 " key exchange in progress, started %s ago\n",
765 GNUNET_STRINGS_relative_time_to_string (age, GNUNET_YES));
766 // FIXME make duration of old keys configurable
767 if (age.rel_value_us < GNUNET_TIME_UNIT_MINUTES.rel_value_us)
769 LOG (GNUNET_ERROR_TYPE_DEBUG, " using old key\n");
770 key = &t->kx_ctx->e_key_old;
774 LOG (GNUNET_ERROR_TYPE_DEBUG, " using new key (old key too old)\n");
780 LOG (GNUNET_ERROR_TYPE_DEBUG, " no KX: using current key\n");
790 * @param plaintext Content to HMAC.
791 * @param size Size of @c plaintext.
792 * @param iv Initialization vector for the message.
793 * @param key Key to use.
794 * @param hmac[out] Destination to store the HMAC.
797 t_hmac (const void *plaintext, size_t size,
798 uint32_t iv, const struct GNUNET_CRYPTO_SymmetricSessionKey *key,
799 struct GNUNET_CADET_Hash *hmac)
801 static const char ctx[] = "cadet authentication key";
802 struct GNUNET_CRYPTO_AuthKey auth_key;
803 struct GNUNET_HashCode hash;
805 #if DUMP_KEYS_TO_STDERR
806 LOG (GNUNET_ERROR_TYPE_INFO, " HMAC with key %s\n",
807 GNUNET_h2s ((struct GNUNET_HashCode *) key));
809 GNUNET_CRYPTO_hmac_derive_key (&auth_key, key,
814 /* Two step: CADET_Hash is only 256 bits, HashCode is 512. */
815 GNUNET_CRYPTO_hmac (&auth_key, plaintext, size, &hash);
816 memcpy (hmac, &hash, sizeof (*hmac));
821 * Encrypt daforce_newest_keyta with the tunnel key.
823 * @param t Tunnel whose key to use.
824 * @param dst Destination for the encrypted data.
825 * @param src Source of the plaintext. Can overlap with @c dst.
826 * @param size Size of the plaintext.
827 * @param iv Initialization Vector to use.
828 * @param force_newest_key Force the use of the newest key, otherwise
829 * CADET will use the old key when allowed.
830 * This can happen in the case when a KX is going on
831 * and the old one hasn't expired.
834 t_encrypt (struct CadetTunnel *t, void *dst, const void *src,
835 size_t size, uint32_t iv, int force_newest_key)
837 struct GNUNET_CRYPTO_SymmetricInitializationVector siv;
838 const struct GNUNET_CRYPTO_SymmetricSessionKey *key;
841 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_encrypt start\n");
843 key = GNUNET_YES == force_newest_key ? &t->e_key : select_key (t);
844 #if DUMP_KEYS_TO_STDERR
845 LOG (GNUNET_ERROR_TYPE_INFO, " ENC with key %s\n",
846 GNUNET_h2s ((struct GNUNET_HashCode *) key));
848 GNUNET_CRYPTO_symmetric_derive_iv (&siv, key, &iv, sizeof (iv), NULL);
849 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_encrypt IV derived\n");
850 out_size = GNUNET_CRYPTO_symmetric_encrypt (src, size, key, &siv, dst);
851 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_encrypt end\n");
858 * Decrypt and verify data with the appropriate tunnel key.
860 * @param key Key to use.
861 * @param dst Destination for the plaintext.
862 * @param src Source of the encrypted data. Can overlap with @c dst.
863 * @param size Size of the encrypted data.
864 * @param iv Initialization Vector to use.
866 * @return Size of the decrypted data, -1 if an error was encountered.
869 decrypt (const struct GNUNET_CRYPTO_SymmetricSessionKey *key,
870 void *dst, const void *src, size_t size, uint32_t iv)
872 struct GNUNET_CRYPTO_SymmetricInitializationVector siv;
875 LOG (GNUNET_ERROR_TYPE_DEBUG, " decrypt start\n");
876 LOG (GNUNET_ERROR_TYPE_DEBUG, " decrypt iv\n");
877 GNUNET_CRYPTO_symmetric_derive_iv (&siv, key, &iv, sizeof (iv), NULL);
878 LOG (GNUNET_ERROR_TYPE_DEBUG, " decrypt iv done\n");
879 out_size = GNUNET_CRYPTO_symmetric_decrypt (src, size, key, &siv, dst);
880 LOG (GNUNET_ERROR_TYPE_DEBUG, " decrypt end\n");
887 * Decrypt and verify data with the most recent tunnel key.
889 * @param t Tunnel whose key to use.
890 * @param dst Destination for the plaintext.
891 * @param src Source of the encrypted data. Can overlap with @c dst.
892 * @param size Size of the encrypted data.
893 * @param iv Initialization Vector to use.
895 * @return Size of the decrypted data, -1 if an error was encountered.
898 t_decrypt (struct CadetTunnel *t, void *dst, const void *src,
899 size_t size, uint32_t iv)
903 #if DUMP_KEYS_TO_STDERR
904 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_decrypt with %s\n",
905 GNUNET_h2s ((struct GNUNET_HashCode *) &t->d_key));
907 if (CADET_TUNNEL_KEY_UNINITIALIZED == t->estate)
909 GNUNET_STATISTICS_update (stats, "# non decryptable data", 1, GNUNET_NO);
910 LOG (GNUNET_ERROR_TYPE_WARNING,
911 "got data on %s without a valid key\n",
913 GCT_debug (t, GNUNET_ERROR_TYPE_WARNING);
917 out_size = decrypt (&t->d_key, dst, src, size, iv);
924 * Decrypt and verify data with the appropriate tunnel key and verify that the
925 * data has not been altered since it was sent by the remote peer.
927 * @param t Tunnel whose key to use.
928 * @param dst Destination for the plaintext.
929 * @param src Source of the encrypted data. Can overlap with @c dst.
930 * @param size Size of the encrypted data.
931 * @param iv Initialization Vector to use.
932 * @param msg_hmac HMAC of the message, cannot be NULL.
934 * @return Size of the decrypted data, -1 if an error was encountered.
937 t_decrypt_and_validate (struct CadetTunnel *t,
938 void *dst, const void *src,
939 size_t size, uint32_t iv,
940 const struct GNUNET_CADET_Hash *msg_hmac)
942 struct GNUNET_CRYPTO_SymmetricSessionKey *key;
943 struct GNUNET_CADET_Hash hmac;
946 /* Try primary (newest) key */
948 decrypted_size = decrypt (key, dst, src, size, iv);
949 t_hmac (src, size, iv, key, &hmac);
950 if (0 == memcmp (msg_hmac, &hmac, sizeof (hmac)))
951 return decrypted_size;
953 /* If no key exchange is going on, we just failed. */
954 if (NULL == t->kx_ctx)
956 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
957 "Failed checksum validation on tunnel %s with no KX\n",
959 GNUNET_STATISTICS_update (stats, "# wrong HMAC no KX", 1, GNUNET_NO);
963 /* Try secondary key, from previous KX period. */
964 key = &t->kx_ctx->d_key_old;
965 decrypted_size = decrypt (key, dst, src, size, iv);
966 t_hmac (src, size, iv, key, &hmac);
967 if (0 == memcmp (msg_hmac, &hmac, sizeof (hmac)))
968 return decrypted_size;
970 /* Hail Mary, try tertiary, key, in case of parallel re-keys. */
971 key = &t->kx_ctx->d_key_old2;
972 decrypted_size = decrypt (key, dst, src, size, iv);
973 t_hmac (src, size, iv, key, &hmac);
974 if (0 == memcmp (msg_hmac, &hmac, sizeof (hmac)))
975 return decrypted_size;
977 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
978 "Failed checksum validation on tunnel %s with KX\n",
980 GNUNET_STATISTICS_update (stats, "# wrong HMAC with KX", 1, GNUNET_NO);
985 * Decrypt and verify data with the appropriate tunnel key and verify that the
986 * data has not been altered since it was sent by the remote peer.
988 * @param t Tunnel whose key to use.
989 * @param dst Destination for the plaintext.
990 * @param src Source of the encrypted data. Can overlap with @c dst.
991 * @param size Size of the encrypted data.
992 * @param msg_hmac HMAC of the message, cannot be NULL.
994 * @return Size of the decrypted data, -1 if an error was encountered.
997 t_ax_decrypt_and_validate (struct CadetTunnel *t,
998 void *dst, const void *src, size_t size,
999 const struct GNUNET_CADET_Hash *msg_hmac)
1001 struct CadetTunnelAxolotl *ax;
1013 * Create key material by doing ECDH on the local and remote ephemeral keys.
1015 * @param key_material Where to store the key material.
1016 * @param ephemeral_key Peer's public ephemeral key.
1019 derive_key_material (struct GNUNET_HashCode *key_material,
1020 const struct GNUNET_CRYPTO_EcdhePublicKey *ephemeral_key)
1023 GNUNET_CRYPTO_ecc_ecdh (my_ephemeral_key,
1033 * Create a symmetic key from the identities of both ends and the key material
1036 * @param key Destination for the generated key.
1037 * @param sender ID of the peer that will encrypt with @c key.
1038 * @param receiver ID of the peer that will decrypt with @c key.
1039 * @param key_material Hash created with ECDH with the ephemeral keys.
1042 derive_symmertic (struct GNUNET_CRYPTO_SymmetricSessionKey *key,
1043 const struct GNUNET_PeerIdentity *sender,
1044 const struct GNUNET_PeerIdentity *receiver,
1045 const struct GNUNET_HashCode *key_material)
1047 const char salt[] = "CADET kx salt";
1049 GNUNET_CRYPTO_kdf (key, sizeof (struct GNUNET_CRYPTO_SymmetricSessionKey),
1050 salt, sizeof (salt),
1051 key_material, sizeof (struct GNUNET_HashCode),
1052 sender, sizeof (struct GNUNET_PeerIdentity),
1053 receiver, sizeof (struct GNUNET_PeerIdentity),
1059 * Derive the tunnel's keys using our own and the peer's ephemeral keys.
1061 * @param t Tunnel for which to create the keys.
1064 create_keys (struct CadetTunnel *t)
1066 struct GNUNET_HashCode km;
1068 derive_key_material (&km, &t->peers_ephemeral_key);
1069 derive_symmertic (&t->e_key, &my_full_id, GCP_get_id (t->peer), &km);
1070 derive_symmertic (&t->d_key, GCP_get_id (t->peer), &my_full_id, &km);
1071 #if DUMP_KEYS_TO_STDERR
1072 LOG (GNUNET_ERROR_TYPE_INFO, "ME: %s\n",
1073 GNUNET_h2s ((struct GNUNET_HashCode *) &kx_msg.ephemeral_key));
1074 LOG (GNUNET_ERROR_TYPE_INFO, "PE: %s\n",
1075 GNUNET_h2s ((struct GNUNET_HashCode *) &t->peers_ephemeral_key));
1076 LOG (GNUNET_ERROR_TYPE_INFO, "KM: %s\n", GNUNET_h2s (&km));
1077 LOG (GNUNET_ERROR_TYPE_INFO, "EK: %s\n",
1078 GNUNET_h2s ((struct GNUNET_HashCode *) &t->e_key));
1079 LOG (GNUNET_ERROR_TYPE_INFO, "DK: %s\n",
1080 GNUNET_h2s ((struct GNUNET_HashCode *) &t->d_key));
1086 * Create a new Key eXchange context for the tunnel.
1088 * If the old keys were verified, keep them for old traffic. Create a new KX
1089 * timestamp and a new nonce.
1091 * @param t Tunnel for which to create the KX ctx.
1094 create_kx_ctx (struct CadetTunnel *t)
1096 LOG (GNUNET_ERROR_TYPE_INFO, " new kx ctx for %s\n", GCT_2s (t));
1098 if (NULL != t->kx_ctx)
1100 if (NULL != t->kx_ctx->finish_task)
1102 LOG (GNUNET_ERROR_TYPE_INFO, " resetting exisiting finish task\n");
1103 GNUNET_SCHEDULER_cancel (t->kx_ctx->finish_task);
1104 t->kx_ctx->finish_task = NULL;
1109 t->kx_ctx = GNUNET_new (struct CadetTunnelKXCtx);
1110 t->kx_ctx->challenge = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE,
1114 if (CADET_TUNNEL_KEY_OK == t->estate)
1116 LOG (GNUNET_ERROR_TYPE_INFO, " backing up keys\n");
1117 t->kx_ctx->d_key_old = t->d_key;
1118 t->kx_ctx->e_key_old = t->e_key;
1121 LOG (GNUNET_ERROR_TYPE_INFO, " old keys not valid, not saving\n");
1122 t->kx_ctx->rekey_start_time = GNUNET_TIME_absolute_get ();
1128 * @brief Finish the Key eXchange and destroy the old keys.
1130 * @param cls Closure (Tunnel for which to finish the KX).
1131 * @param tc Task context.
1134 finish_kx (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
1136 struct CadetTunnel *t = cls;
1138 LOG (GNUNET_ERROR_TYPE_INFO, "finish KX for %s\n", GCT_2s (t));
1140 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
1142 LOG (GNUNET_ERROR_TYPE_INFO, " shutdown\n");
1146 GNUNET_free (t->kx_ctx);
1152 * Destroy a Key eXchange context for the tunnel. This function only schedules
1153 * the destruction, the freeing of the memory (and clearing of old key material)
1154 * happens after a delay!
1156 * @param t Tunnel whose KX ctx to destroy.
1159 destroy_kx_ctx (struct CadetTunnel *t)
1161 struct GNUNET_TIME_Relative delay;
1163 if (NULL == t->kx_ctx || NULL != t->kx_ctx->finish_task)
1166 if (is_key_null (&t->kx_ctx->e_key_old))
1168 t->kx_ctx->finish_task = GNUNET_SCHEDULER_add_now (finish_kx, t);
1172 delay = GNUNET_TIME_relative_divide (rekey_period, 4);
1173 delay = GNUNET_TIME_relative_min (delay, GNUNET_TIME_UNIT_MINUTES);
1175 t->kx_ctx->finish_task = GNUNET_SCHEDULER_add_delayed (delay, finish_kx, t);
1181 * Pick a connection on which send the next data message.
1183 * @param t Tunnel on which to send the message.
1185 * @return The connection on which to send the next message.
1187 static struct CadetConnection *
1188 tunnel_get_connection (struct CadetTunnel *t)
1190 struct CadetTConnection *iter;
1191 struct CadetConnection *best;
1193 unsigned int lowest_q;
1195 LOG (GNUNET_ERROR_TYPE_DEBUG, "tunnel_get_connection %s\n", GCT_2s (t));
1197 lowest_q = UINT_MAX;
1198 for (iter = t->connection_head; NULL != iter; iter = iter->next)
1200 LOG (GNUNET_ERROR_TYPE_DEBUG, " connection %s: %u\n",
1201 GCC_2s (iter->c), GCC_get_state (iter->c));
1202 if (CADET_CONNECTION_READY == GCC_get_state (iter->c))
1204 qn = GCC_get_qn (iter->c, GCC_is_origin (iter->c, GNUNET_YES));
1205 LOG (GNUNET_ERROR_TYPE_DEBUG, " q_n %u, \n", qn);
1213 LOG (GNUNET_ERROR_TYPE_DEBUG, " selected: connection %s\n", GCC_2s (best));
1219 * Callback called when a queued message is sent.
1221 * Calculates the average time and connection packet tracking.
1223 * @param cls Closure (TunnelQueue handle).
1224 * @param c Connection this message was on.
1225 * @param q Connection queue handle (unused).
1226 * @param type Type of message sent.
1227 * @param fwd Was this a FWD going message?
1228 * @param size Size of the message.
1231 tun_message_sent (void *cls,
1232 struct CadetConnection *c,
1233 struct CadetConnectionQueue *q,
1234 uint16_t type, int fwd, size_t size)
1236 struct CadetTunnelQueue *qt = cls;
1237 struct CadetTunnel *t;
1239 LOG (GNUNET_ERROR_TYPE_DEBUG, "tun_message_sent\n");
1241 GNUNET_assert (NULL != qt->cont);
1242 t = NULL == c ? NULL : GCC_get_tunnel (c);
1243 qt->cont (qt->cont_cls, t, qt, type, size);
1249 count_queued_data (const struct CadetTunnel *t)
1251 struct CadetTunnelDelayed *iter;
1254 for (count = 0, iter = t->tq_head; iter != NULL; iter = iter->next)
1261 * Delete a queued message: either was sent or the channel was destroyed
1262 * before the tunnel's key exchange had a chance to finish.
1264 * @param tqd Delayed queue handle.
1267 unqueue_data (struct CadetTunnelDelayed *tqd)
1269 GNUNET_CONTAINER_DLL_remove (tqd->t->tq_head, tqd->t->tq_tail, tqd);
1275 * Cache a message to be sent once tunnel is online.
1277 * @param t Tunnel to hold the message.
1278 * @param msg Message itself (copy will be made).
1280 static struct CadetTunnelDelayed *
1281 queue_data (struct CadetTunnel *t, const struct GNUNET_MessageHeader *msg)
1283 struct CadetTunnelDelayed *tqd;
1284 uint16_t size = ntohs (msg->size);
1286 LOG (GNUNET_ERROR_TYPE_DEBUG, "queue data on Tunnel %s\n", GCT_2s (t));
1288 if (GNUNET_YES == is_ready (t))
1294 tqd = GNUNET_malloc (sizeof (struct CadetTunnelDelayed) + size);
1297 memcpy (&tqd[1], msg, size);
1298 GNUNET_CONTAINER_DLL_insert_tail (t->tq_head, t->tq_tail, tqd);
1304 * Sends an already built message on a tunnel, encrypting it and
1305 * choosing the best connection.
1307 * @param message Message to send. Function modifies it.
1308 * @param t Tunnel on which this message is transmitted.
1309 * @param c Connection to use (autoselect if NULL).
1310 * @param force Force the tunnel to take the message (buffer overfill).
1311 * @param cont Continuation to call once message is really sent.
1312 * @param cont_cls Closure for @c cont.
1313 * @param existing_q In case this a transmission of previously queued data,
1314 * this should be TunnelQueue given to the client.
1317 * @return Handle to cancel message.
1318 * NULL if @c cont is NULL or an error happens and message is dropped.
1320 static struct CadetTunnelQueue *
1321 send_prebuilt_message (const struct GNUNET_MessageHeader *message,
1322 struct CadetTunnel *t, struct CadetConnection *c,
1323 int force, GCT_sent cont, void *cont_cls,
1324 struct CadetTunnelQueue *existing_q)
1326 struct CadetTunnelQueue *tq;
1327 struct GNUNET_CADET_Encrypted *msg;
1328 size_t size = ntohs (message->size);
1329 char cbuf[sizeof (struct GNUNET_CADET_Encrypted) + size];
1335 LOG (GNUNET_ERROR_TYPE_DEBUG, "GMT Send on Tunnel %s\n", GCT_2s (t));
1337 if (GNUNET_NO == is_ready (t))
1339 struct CadetTunnelDelayed *tqd;
1340 /* A non null existing_q indicates sending of queued data.
1341 * Should only happen after tunnel becomes ready.
1343 GNUNET_assert (NULL == existing_q);
1344 tqd = queue_data (t, message);
1347 tq = GNUNET_new (struct CadetTunnelQueue);
1351 tq->cont_cls = cont_cls;
1355 GNUNET_assert (GNUNET_NO == GCT_is_loopback (t));
1357 iv = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX);
1358 msg = (struct GNUNET_CADET_Encrypted *) cbuf;
1359 msg->header.type = htons (GNUNET_MESSAGE_TYPE_CADET_ENCRYPTED);
1361 GNUNET_assert (t_encrypt (t, &msg[1], message, size, iv, GNUNET_NO) == size);
1362 t_hmac (&msg[1], size, iv, select_key (t), &msg->hmac);
1363 msg->header.size = htons (sizeof (struct GNUNET_CADET_Encrypted) + size);
1366 c = tunnel_get_connection (t);
1369 /* Why is tunnel 'ready'? Should have been queued! */
1370 if (NULL != t->destroy_task)
1373 GCT_debug (t, GNUNET_ERROR_TYPE_WARNING);
1375 return NULL; /* Drop... */
1379 type = ntohs (message->type);
1382 case GNUNET_MESSAGE_TYPE_CADET_DATA:
1383 case GNUNET_MESSAGE_TYPE_CADET_DATA_ACK:
1384 if (GNUNET_MESSAGE_TYPE_CADET_DATA == type)
1385 mid = ntohl (((struct GNUNET_CADET_Data *) message)->mid);
1387 mid = ntohl (((struct GNUNET_CADET_DataACK *) message)->mid);
1389 case GNUNET_MESSAGE_TYPE_CADET_KEEPALIVE:
1390 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_CREATE:
1391 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_DESTROY:
1392 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_ACK:
1393 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_NACK:
1394 msg->cid = *GCC_get_id (c);
1395 msg->ttl = htonl (default_ttl);
1399 LOG (GNUNET_ERROR_TYPE_ERROR, "type %s not valid\n", GC_m2s (type));
1401 LOG (GNUNET_ERROR_TYPE_DEBUG, "type %s\n", GC_m2s (type));
1403 fwd = GCC_is_origin (c, GNUNET_YES);
1407 GNUNET_break (NULL == GCC_send_prebuilt_message (&msg->header, type, mid, c,
1408 fwd, force, NULL, NULL));
1411 if (NULL == existing_q)
1413 tq = GNUNET_new (struct CadetTunnelQueue); /* FIXME valgrind: leak*/
1420 tq->cq = GCC_send_prebuilt_message (&msg->header, type, mid, c, fwd, force,
1421 &tun_message_sent, tq);
1422 GNUNET_assert (NULL != tq->cq);
1424 tq->cont_cls = cont_cls;
1431 * Send all cached messages that we can, tunnel is online.
1433 * @param t Tunnel that holds the messages. Cannot be loopback.
1436 send_queued_data (struct CadetTunnel *t)
1438 struct CadetTunnelDelayed *tqd;
1439 struct CadetTunnelDelayed *next;
1442 LOG (GNUNET_ERROR_TYPE_INFO, "Send queued data, tunnel %s\n", GCT_2s (t));
1444 if (GCT_is_loopback (t))
1450 if (GNUNET_NO == is_ready (t))
1452 LOG (GNUNET_ERROR_TYPE_DEBUG, " not ready yet: %s/%s\n",
1453 estate2s (t->estate), cstate2s (t->cstate));
1457 room = GCT_get_connections_buffer (t);
1458 LOG (GNUNET_ERROR_TYPE_DEBUG, " buffer space: %u\n", room);
1459 LOG (GNUNET_ERROR_TYPE_DEBUG, " tq head: %p\n", t->tq_head);
1460 for (tqd = t->tq_head; NULL != tqd && room > 0; tqd = next)
1462 LOG (GNUNET_ERROR_TYPE_DEBUG, " sending queued data\n");
1465 send_prebuilt_message ((struct GNUNET_MessageHeader *) &tqd[1],
1466 tqd->t, NULL, GNUNET_YES,
1467 NULL != tqd->tq ? tqd->tq->cont : NULL,
1468 NULL != tqd->tq ? tqd->tq->cont_cls : NULL,
1472 LOG (GNUNET_ERROR_TYPE_DEBUG, "GCT_send_queued_data end\n", GCP_2s (t->peer));
1477 * Callback called when a queued message is sent.
1479 * @param cls Closure.
1480 * @param c Connection this message was on.
1481 * @param type Type of message sent.
1482 * @param fwd Was this a FWD going message?
1483 * @param size Size of the message.
1486 ephm_sent (void *cls,
1487 struct CadetConnection *c,
1488 struct CadetConnectionQueue *q,
1489 uint16_t type, int fwd, size_t size)
1491 struct CadetTunnel *t = cls;
1492 LOG (GNUNET_ERROR_TYPE_DEBUG, "ephm_sent %s\n", GC_m2s (type));
1497 * Callback called when a queued message is sent.
1499 * @param cls Closure.
1500 * @param c Connection this message was on.
1501 * @param type Type of message sent.
1502 * @param fwd Was this a FWD going message?
1503 * @param size Size of the message.
1506 pong_sent (void *cls,
1507 struct CadetConnection *c,
1508 struct CadetConnectionQueue *q,
1509 uint16_t type, int fwd, size_t size)
1511 struct CadetTunnel *t = cls;
1512 LOG (GNUNET_ERROR_TYPE_DEBUG, "pong_sent %s\n", GC_m2s (type));
1518 * Sends key exchange message on a tunnel, choosing the best connection.
1519 * Should not be called on loopback tunnels.
1521 * @param t Tunnel on which this message is transmitted.
1522 * @param message Message to send. Function modifies it.
1524 * @return Handle to the message in the connection queue.
1526 static struct CadetConnectionQueue *
1527 send_kx (struct CadetTunnel *t,
1528 const struct GNUNET_MessageHeader *message)
1530 struct CadetConnection *c;
1531 struct GNUNET_CADET_KX *msg;
1532 size_t size = ntohs (message->size);
1533 char cbuf[sizeof (struct GNUNET_CADET_KX) + size];
1538 LOG (GNUNET_ERROR_TYPE_DEBUG, "GMT KX on Tunnel %s\n", GCT_2s (t));
1540 /* Avoid loopback. */
1541 if (GCT_is_loopback (t))
1543 LOG (GNUNET_ERROR_TYPE_DEBUG, " loopback!\n");
1547 type = ntohs (message->type);
1549 /* Even if tunnel is "being destroyed", send anyway.
1550 * Could be a response to a rekey initiated by remote peer,
1551 * who is trying to create a new channel!
1554 /* Must have a connection, or be looking for one. */
1555 if (NULL == t->connection_head)
1557 LOG (GNUNET_ERROR_TYPE_DEBUG, "%s while no connection\n", GC_m2s (type));
1558 if (CADET_TUNNEL_SEARCHING != t->cstate)
1561 GCT_debug (t, GNUNET_ERROR_TYPE_ERROR);
1562 GCP_debug (t->peer, GNUNET_ERROR_TYPE_ERROR);
1567 msg = (struct GNUNET_CADET_KX *) cbuf;
1568 msg->header.type = htons (GNUNET_MESSAGE_TYPE_CADET_KX);
1569 msg->header.size = htons (sizeof (struct GNUNET_CADET_KX) + size);
1570 c = tunnel_get_connection (t);
1573 if (NULL == t->destroy_task
1574 && CADET_TUNNEL_READY == t->cstate)
1577 GCT_debug (t, GNUNET_ERROR_TYPE_ERROR);
1583 case GNUNET_MESSAGE_TYPE_CADET_KX_EPHEMERAL:
1584 GNUNET_assert (NULL == t->ephm_h);
1586 memcpy (&msg[1], message, size);
1588 case GNUNET_MESSAGE_TYPE_CADET_KX_PONG:
1589 GNUNET_assert (NULL == t->pong_h);
1591 memcpy (&msg[1], message, size);
1595 LOG (GNUNET_ERROR_TYPE_DEBUG, "unkown type %s\n", GC_m2s (type));
1599 fwd = GCC_is_origin (t->connection_head->c, GNUNET_YES);
1601 return GCC_send_prebuilt_message (&msg->header, type, 0, c,
1608 * Send the ephemeral key on a tunnel.
1610 * @param t Tunnel on which to send the key.
1613 send_ephemeral (struct CadetTunnel *t)
1615 LOG (GNUNET_ERROR_TYPE_INFO, "===> EPHM for %s\n", GCT_2s (t));
1616 if (NULL != t->ephm_h)
1618 LOG (GNUNET_ERROR_TYPE_INFO, " already queued\n");
1622 kx_msg.sender_status = htonl (t->estate);
1623 kx_msg.iv = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX);
1624 kx_msg.nonce = t->kx_ctx->challenge;
1625 LOG (GNUNET_ERROR_TYPE_DEBUG, " send nonce c %u\n", kx_msg.nonce);
1626 t_encrypt (t, &kx_msg.nonce, &kx_msg.nonce,
1627 ping_encryption_size(), kx_msg.iv, GNUNET_YES);
1628 LOG (GNUNET_ERROR_TYPE_DEBUG, " send nonce e %u\n", kx_msg.nonce);
1629 t->ephm_h = send_kx (t, &kx_msg.header);
1634 * Send a pong message on a tunnel.
1636 * @param t Tunnel on which to send the pong.
1637 * @param challenge Value sent in the ping that we have to send back.
1640 send_pong (struct CadetTunnel *t, uint32_t challenge)
1642 struct GNUNET_CADET_KX_Pong msg;
1644 LOG (GNUNET_ERROR_TYPE_INFO, "===> PONG for %s\n", GCT_2s (t));
1645 if (NULL != t->pong_h)
1647 LOG (GNUNET_ERROR_TYPE_INFO, " already queued\n");
1650 msg.header.size = htons (sizeof (msg));
1651 msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_KX_PONG);
1652 msg.iv = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX);
1653 msg.nonce = challenge;
1654 LOG (GNUNET_ERROR_TYPE_DEBUG, " sending %u\n", msg.nonce);
1655 t_encrypt (t, &msg.nonce, &msg.nonce,
1656 sizeof (msg.nonce), msg.iv, GNUNET_YES);
1657 LOG (GNUNET_ERROR_TYPE_DEBUG, " e sending %u\n", msg.nonce);
1659 t->pong_h = send_kx (t, &msg.header);
1664 * Initiate a rekey with the remote peer.
1666 * @param cls Closure (tunnel).
1667 * @param tc TaskContext.
1670 rekey_tunnel (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
1672 struct CadetTunnel *t = cls;
1674 t->rekey_task = NULL;
1676 LOG (GNUNET_ERROR_TYPE_INFO, "Re-key Tunnel %s\n", GCT_2s (t));
1677 if (NULL != tc && 0 != (GNUNET_SCHEDULER_REASON_SHUTDOWN & tc->reason))
1680 GNUNET_assert (NULL != t->kx_ctx);
1681 struct GNUNET_TIME_Relative duration;
1683 duration = GNUNET_TIME_absolute_get_duration (t->kx_ctx->rekey_start_time);
1684 LOG (GNUNET_ERROR_TYPE_DEBUG, " kx started %s ago\n",
1685 GNUNET_STRINGS_relative_time_to_string (duration, GNUNET_YES));
1687 // FIXME make duration of old keys configurable
1688 if (duration.rel_value_us >= GNUNET_TIME_UNIT_MINUTES.rel_value_us)
1690 LOG (GNUNET_ERROR_TYPE_DEBUG, " deleting old keys\n");
1691 memset (&t->kx_ctx->d_key_old, 0, sizeof (t->kx_ctx->d_key_old));
1692 memset (&t->kx_ctx->e_key_old, 0, sizeof (t->kx_ctx->e_key_old));
1699 case CADET_TUNNEL_KEY_UNINITIALIZED:
1700 GCT_change_estate (t, CADET_TUNNEL_KEY_SENT);
1703 case CADET_TUNNEL_KEY_SENT:
1706 case CADET_TUNNEL_KEY_OK:
1708 * - state should have changed during rekey_iterator
1709 * - task should have been canceled at pong_handle
1712 GCT_change_estate (t, CADET_TUNNEL_KEY_REKEY);
1715 case CADET_TUNNEL_KEY_PING:
1716 case CADET_TUNNEL_KEY_REKEY:
1720 LOG (GNUNET_ERROR_TYPE_DEBUG, "Unexpected state %u\n", t->estate);
1723 // FIXME exponential backoff
1724 struct GNUNET_TIME_Relative delay;
1726 delay = GNUNET_TIME_relative_divide (rekey_period, 16);
1727 delay = GNUNET_TIME_relative_min (delay, REKEY_WAIT);
1728 LOG (GNUNET_ERROR_TYPE_DEBUG, " next call in %s\n",
1729 GNUNET_STRINGS_relative_time_to_string (delay, GNUNET_YES));
1730 t->rekey_task = GNUNET_SCHEDULER_add_delayed (delay, &rekey_tunnel, t);
1735 * Our ephemeral key has changed, create new session key on all tunnels.
1737 * Each tunnel will start the Key Exchange with a random delay between
1738 * 0 and number_of_tunnels*100 milliseconds, so there are 10 key exchanges
1739 * per second, on average.
1741 * @param cls Closure (size of the hashmap).
1742 * @param key Current public key.
1743 * @param value Value in the hash map (tunnel).
1745 * @return #GNUNET_YES, so we should continue to iterate,
1748 rekey_iterator (void *cls,
1749 const struct GNUNET_PeerIdentity *key,
1752 struct CadetTunnel *t = value;
1753 struct GNUNET_TIME_Relative delay;
1754 long n = (long) cls;
1757 if (NULL != t->rekey_task)
1760 if (GNUNET_YES == GCT_is_loopback (t))
1763 r = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK, (uint32_t) n * 100);
1764 delay = GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MILLISECONDS, r);
1765 t->rekey_task = GNUNET_SCHEDULER_add_delayed (delay, &rekey_tunnel, t);
1767 GCT_change_estate (t, CADET_TUNNEL_KEY_REKEY);
1774 * Create a new ephemeral key and key message, schedule next rekeying.
1776 * @param cls Closure (unused).
1777 * @param tc TaskContext.
1780 rekey (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
1782 struct GNUNET_TIME_Absolute time;
1787 if (0 != (GNUNET_SCHEDULER_REASON_SHUTDOWN & tc->reason))
1790 GNUNET_free_non_null (my_ephemeral_key);
1791 my_ephemeral_key = GNUNET_CRYPTO_ecdhe_key_create ();
1793 time = GNUNET_TIME_absolute_get ();
1794 kx_msg.creation_time = GNUNET_TIME_absolute_hton (time);
1795 time = GNUNET_TIME_absolute_add (time, rekey_period);
1796 time = GNUNET_TIME_absolute_add (time, GNUNET_TIME_UNIT_MINUTES);
1797 kx_msg.expiration_time = GNUNET_TIME_absolute_hton (time);
1798 GNUNET_CRYPTO_ecdhe_key_get_public (my_ephemeral_key, &kx_msg.ephemeral_key);
1799 LOG (GNUNET_ERROR_TYPE_INFO, "GLOBAL RE-KEY, NEW EPHM: %s\n",
1800 GNUNET_h2s ((struct GNUNET_HashCode *) &kx_msg.ephemeral_key));
1802 GNUNET_assert (GNUNET_OK ==
1803 GNUNET_CRYPTO_eddsa_sign (my_private_key,
1805 &kx_msg.signature));
1807 n = (long) GNUNET_CONTAINER_multipeermap_size (tunnels);
1808 GNUNET_CONTAINER_multipeermap_iterate (tunnels, &rekey_iterator, (void *) n);
1810 rekey_task = GNUNET_SCHEDULER_add_delayed (rekey_period, &rekey, NULL);
1815 * Called only on shutdown, destroy every tunnel.
1817 * @param cls Closure (unused).
1818 * @param key Current public key.
1819 * @param value Value in the hash map (tunnel).
1821 * @return #GNUNET_YES, so we should continue to iterate,
1824 destroy_iterator (void *cls,
1825 const struct GNUNET_PeerIdentity *key,
1828 struct CadetTunnel *t = value;
1830 LOG (GNUNET_ERROR_TYPE_DEBUG, "GCT_shutdown destroying tunnel at %p\n", t);
1837 * Notify remote peer that we don't know a channel he is talking about,
1838 * probably CHANNEL_DESTROY was missed.
1840 * @param t Tunnel on which to notify.
1841 * @param gid ID of the channel.
1844 send_channel_destroy (struct CadetTunnel *t, unsigned int gid)
1846 struct GNUNET_CADET_ChannelManage msg;
1848 msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_CHANNEL_DESTROY);
1849 msg.header.size = htons (sizeof (msg));
1850 msg.chid = htonl (gid);
1852 LOG (GNUNET_ERROR_TYPE_DEBUG,
1853 "WARNING destroying unknown channel %u on tunnel %s\n",
1855 send_prebuilt_message (&msg.header, t, NULL, GNUNET_YES, NULL, NULL, NULL);
1860 * Demultiplex data per channel and call appropriate channel handler.
1862 * @param t Tunnel on which the data came.
1863 * @param msg Data message.
1864 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
1865 * #GNUNET_YES if message is FWD on the respective channel (loopback)
1866 * #GNUNET_NO if message is BCK on the respective channel (loopback)
1867 * #GNUNET_SYSERR if message on a one-ended channel (remote)
1870 handle_data (struct CadetTunnel *t,
1871 const struct GNUNET_CADET_Data *msg,
1874 struct CadetChannel *ch;
1878 size = ntohs (msg->header.size);
1880 sizeof (struct GNUNET_CADET_Data) +
1881 sizeof (struct GNUNET_MessageHeader))
1886 LOG (GNUNET_ERROR_TYPE_DEBUG, " payload of type %s\n",
1887 GC_m2s (ntohs (msg[1].header.type)));
1890 ch = GCT_get_channel (t, ntohl (msg->chid));
1893 GNUNET_STATISTICS_update (stats, "# data on unknown channel",
1895 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel 0x%X unknown\n",
1897 send_channel_destroy (t, ntohl (msg->chid));
1901 GCCH_handle_data (ch, msg, fwd);
1906 * Demultiplex data ACKs per channel and update appropriate channel buffer info.
1908 * @param t Tunnel on which the DATA ACK came.
1909 * @param msg DATA ACK message.
1910 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
1911 * #GNUNET_YES if message is FWD on the respective channel (loopback)
1912 * #GNUNET_NO if message is BCK on the respective channel (loopback)
1913 * #GNUNET_SYSERR if message on a one-ended channel (remote)
1916 handle_data_ack (struct CadetTunnel *t,
1917 const struct GNUNET_CADET_DataACK *msg,
1920 struct CadetChannel *ch;
1924 size = ntohs (msg->header.size);
1925 if (size != sizeof (struct GNUNET_CADET_DataACK))
1932 ch = GCT_get_channel (t, ntohl (msg->chid));
1935 GNUNET_STATISTICS_update (stats, "# data ack on unknown channel",
1937 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel %u unknown\n",
1942 GCCH_handle_data_ack (ch, msg, fwd);
1947 * Handle channel create.
1949 * @param t Tunnel on which the data came.
1950 * @param msg Data message.
1953 handle_ch_create (struct CadetTunnel *t,
1954 const struct GNUNET_CADET_ChannelCreate *msg)
1956 struct CadetChannel *ch;
1960 size = ntohs (msg->header.size);
1961 if (size != sizeof (struct GNUNET_CADET_ChannelCreate))
1968 ch = GCT_get_channel (t, ntohl (msg->chid));
1969 if (NULL != ch && ! GCT_is_loopback (t))
1971 /* Probably a retransmission, safe to ignore */
1972 LOG (GNUNET_ERROR_TYPE_DEBUG, " already exists...\n");
1974 ch = GCCH_handle_create (t, msg);
1976 GCT_add_channel (t, ch);
1982 * Handle channel NACK: check correctness and call channel handler for NACKs.
1984 * @param t Tunnel on which the NACK came.
1985 * @param msg NACK message.
1988 handle_ch_nack (struct CadetTunnel *t,
1989 const struct GNUNET_CADET_ChannelManage *msg)
1991 struct CadetChannel *ch;
1995 size = ntohs (msg->header.size);
1996 if (size != sizeof (struct GNUNET_CADET_ChannelManage))
2003 ch = GCT_get_channel (t, ntohl (msg->chid));
2006 GNUNET_STATISTICS_update (stats, "# channel NACK on unknown channel",
2008 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel %u unknown\n",
2013 GCCH_handle_nack (ch);
2018 * Handle a CHANNEL ACK (SYNACK/ACK).
2020 * @param t Tunnel on which the CHANNEL ACK came.
2021 * @param msg CHANNEL ACK message.
2022 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
2023 * #GNUNET_YES if message is FWD on the respective channel (loopback)
2024 * #GNUNET_NO if message is BCK on the respective channel (loopback)
2025 * #GNUNET_SYSERR if message on a one-ended channel (remote)
2028 handle_ch_ack (struct CadetTunnel *t,
2029 const struct GNUNET_CADET_ChannelManage *msg,
2032 struct CadetChannel *ch;
2036 size = ntohs (msg->header.size);
2037 if (size != sizeof (struct GNUNET_CADET_ChannelManage))
2044 ch = GCT_get_channel (t, ntohl (msg->chid));
2047 GNUNET_STATISTICS_update (stats, "# channel ack on unknown channel",
2049 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel %u unknown\n",
2054 GCCH_handle_ack (ch, msg, fwd);
2059 * Handle a channel destruction message.
2061 * @param t Tunnel on which the message came.
2062 * @param msg Channel destroy message.
2063 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
2064 * #GNUNET_YES if message is FWD on the respective channel (loopback)
2065 * #GNUNET_NO if message is BCK on the respective channel (loopback)
2066 * #GNUNET_SYSERR if message on a one-ended channel (remote)
2069 handle_ch_destroy (struct CadetTunnel *t,
2070 const struct GNUNET_CADET_ChannelManage *msg,
2073 struct CadetChannel *ch;
2077 size = ntohs (msg->header.size);
2078 if (size != sizeof (struct GNUNET_CADET_ChannelManage))
2085 ch = GCT_get_channel (t, ntohl (msg->chid));
2088 /* Probably a retransmission, safe to ignore */
2092 GCCH_handle_destroy (ch, msg, fwd);
2097 new_ephemeral (struct CadetTunnel *t)
2099 GNUNET_free_non_null (t->ax->DHRs);
2100 t->ax->DHRs = GNUNET_CRYPTO_ecdhe_key_create();
2105 destroy_ax (struct CadetTunnel *t)
2110 if (NULL != t->ax->DHRs)
2111 GNUNET_free (t->ax->DHRs);
2112 GNUNET_free (t->ax);
2119 * The peer's ephemeral key has changed: update the symmetrical keys.
2121 * @param t Tunnel this message came on.
2122 * @param msg Key eXchange message.
2125 handle_ephemeral (struct CadetTunnel *t,
2126 const struct GNUNET_CADET_KX_Ephemeral *msg)
2128 LOG (GNUNET_ERROR_TYPE_INFO, "<=== EPHM for %s\n", GCT_2s (t));
2130 if (GNUNET_OK != check_ephemeral (t, msg))
2132 GNUNET_break_op (0);
2136 /* If we get a proper OTR-style ephemeral, fallback to old crypto. */
2140 t->enc_type = CADET_Fallback;
2144 * If the key is different from what we know, derive the new E/D keys.
2145 * Else destroy the rekey ctx (duplicate EPHM after successful KX).
2147 if (0 != memcmp (&t->peers_ephemeral_key, &msg->ephemeral_key,
2148 sizeof (msg->ephemeral_key)))
2150 #if DUMP_KEYS_TO_STDERR
2151 LOG (GNUNET_ERROR_TYPE_INFO, "OLD: %s\n",
2152 GNUNET_h2s ((struct GNUNET_HashCode *) &t->peers_ephemeral_key));
2153 LOG (GNUNET_ERROR_TYPE_INFO, "NEW: %s\n",
2154 GNUNET_h2s ((struct GNUNET_HashCode *) &msg->ephemeral_key));
2156 t->peers_ephemeral_key = msg->ephemeral_key;
2160 if (CADET_TUNNEL_KEY_OK == t->estate)
2162 GCT_change_estate (t, CADET_TUNNEL_KEY_REKEY);
2164 if (NULL != t->rekey_task)
2165 GNUNET_SCHEDULER_cancel (t->rekey_task);
2166 t->rekey_task = GNUNET_SCHEDULER_add_now (rekey_tunnel, t);
2168 if (CADET_TUNNEL_KEY_SENT == t->estate)
2170 LOG (GNUNET_ERROR_TYPE_DEBUG, " our key was sent, sending challenge\n");
2172 GCT_change_estate (t, CADET_TUNNEL_KEY_PING);
2175 if (CADET_TUNNEL_KEY_UNINITIALIZED != ntohl(msg->sender_status))
2179 LOG (GNUNET_ERROR_TYPE_DEBUG, " recv nonce e %u\n", msg->nonce);
2180 t_decrypt (t, &nonce, &msg->nonce, ping_encryption_size (), msg->iv);
2181 LOG (GNUNET_ERROR_TYPE_DEBUG, " recv nonce c %u\n", nonce);
2182 send_pong (t, nonce);
2188 * Peer has answer to our challenge.
2189 * If answer is successful, consider the key exchange finished and clean
2190 * up all related state.
2192 * @param t Tunnel this message came on.
2193 * @param msg Key eXchange Pong message.
2196 handle_pong (struct CadetTunnel *t, const struct GNUNET_CADET_KX_Pong *msg)
2200 LOG (GNUNET_ERROR_TYPE_INFO, "<=== PONG for %s\n", GCT_2s (t));
2201 if (NULL == t->rekey_task)
2203 GNUNET_STATISTICS_update (stats, "# duplicate PONG messages", 1, GNUNET_NO);
2206 if (NULL == t->kx_ctx)
2208 GNUNET_STATISTICS_update (stats, "# stray PONG messages", 1, GNUNET_NO);
2212 t_decrypt (t, &challenge, &msg->nonce, sizeof (uint32_t), msg->iv);
2213 if (challenge != t->kx_ctx->challenge)
2215 LOG (GNUNET_ERROR_TYPE_WARNING, "Wrong PONG challenge on %s\n", GCT_2s (t));
2216 LOG (GNUNET_ERROR_TYPE_DEBUG, "PONG: %u (e: %u). Expected: %u.\n",
2217 challenge, msg->nonce, t->kx_ctx->challenge);
2221 GNUNET_SCHEDULER_cancel (t->rekey_task);
2222 t->rekey_task = NULL;
2224 /* Don't free the old keys right away, but after a delay.
2225 * Rationale: the KX could have happened over a very fast connection,
2226 * with payload traffic still signed with the old key stuck in a slower
2228 * Don't keep the keys longer than 1/4 the rekey period, and no longer than
2232 GCT_change_estate (t, CADET_TUNNEL_KEY_OK);
2244 * WARNING! DANGER! Do not use this if you don't know what you are doing!
2245 * Ask Christian Grothoff, Werner Koch, Dan Bernstein and $GOD!
2247 * Transform a private EdDSA key (peer's key) into a key usable by DH.
2249 * @param k Private EdDSA key to transform.
2251 * @return Private key for EC Diffie-Hellman.
2253 static const struct GNUNET_CRYPTO_EcdhePrivateKey *
2254 get_private_ecdhe_from_eddsa (const struct GNUNET_CRYPTO_EddsaPrivateKey *k)
2256 return (const struct GNUNET_CRYPTO_EcdhePrivateKey *) k;
2261 * WARNING! DANGER! Do not use this if you don't know what you are doing!
2262 * Ask Christian Grothoff, Werner Koch, Dan Bernstein and $GOD!
2264 * Transform a public EdDSA key (peer's key) into a key usable by DH.
2266 * @param k Public EdDSA key to transform (peer's ID).
2268 * @return Public key for EC Diffie-Hellman.
2270 static const struct GNUNET_CRYPTO_EcdhePublicKey *
2271 get_public_ecdhe_from_eddsa (const struct GNUNET_CRYPTO_EddsaPublicKey *k)
2273 return (const struct GNUNET_CRYPTO_EcdhePublicKey *) k;
2278 * WARNING! DANGER! Do not use this if you don't know what you are doing!
2279 * Ask Christian Grothoff, Werner Koch, Dan Bernstein and $GOD!
2281 * Transform a public EdDSA key (peer's key) into a key usable by DH.
2283 * @param k Public EdDSA key to transform (peer's ID).
2285 * @return Public key for EC Diffie-Hellman.
2287 static const struct GNUNET_CRYPTO_EcdhePublicKey *
2288 get_public_ecdhe_from_id (const struct GNUNET_PeerIdentity *id)
2290 return (const struct GNUNET_CRYPTO_EcdhePublicKey *) id;
2295 * Handle Axolotl handshake.
2297 * @param t Tunnel this message came on.
2298 * @param msg Key eXchange Pong message.
2301 handle_kx_ax (struct CadetTunnel *t, const struct GNUNET_CADET_AX_KX *msg)
2303 struct GNUNET_CRYPTO_EcdhePublicKey eph;
2304 struct CadetTunnelAxolotl *ax;
2305 struct GNUNET_HashCode key_material[3];
2306 struct GNUNET_CRYPTO_SymmetricSessionKey keys[5];
2307 const struct GNUNET_CRYPTO_EcdhePublicKey *DHIr;
2308 struct GNUNET_CRYPTO_EcdhePrivateKey *DHIs;
2309 const char salt[] = "CADET Axolotl salt";
2313 /* Something is wrong if ax is NULL. Whose fault it is? */
2314 GNUNET_break_op (CADET_Fallback == t->enc_type);
2315 GNUNET_break (CADET_Axolotl == t->enc_type);
2320 ax->DHRr = msg->ratchet_key;
2322 GNUNET_CRYPTO_ecdhe_key_get_public (ax->DHRs, &eph);
2323 if (0 != memcmp (&eph, &msg->peers_key, sizeof (eph)))
2329 DHIr = get_public_ecdhe_from_id (GCT_get_destination (t));
2333 GNUNET_CRYPTO_ecc_ecdh (DHIs,
2334 &msg->ephemeral_key,
2336 GNUNET_CRYPTO_ecc_ecdh (ax->DHRs,
2339 GNUNET_CRYPTO_ecc_ecdh (ax->DHRs,
2340 &msg->ephemeral_key,
2344 GNUNET_CRYPTO_kdf (keys, sizeof (keys),
2345 salt, sizeof (salt),
2346 key_material, sizeof (key_material), NULL);
2351 * Demultiplex by message type and call appropriate handler for a message
2352 * towards a channel of a local tunnel.
2354 * @param t Tunnel this message came on.
2355 * @param msgh Message header.
2356 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
2357 * #GNUNET_YES if message is FWD on the respective channel (loopback)
2358 * #GNUNET_NO if message is BCK on the respective channel (loopback)
2359 * #GNUNET_SYSERR if message on a one-ended channel (remote)
2362 handle_decrypted (struct CadetTunnel *t,
2363 const struct GNUNET_MessageHeader *msgh,
2368 type = ntohs (msgh->type);
2369 LOG (GNUNET_ERROR_TYPE_INFO, "<=== %s on %s\n", GC_m2s (type), GCT_2s (t));
2373 case GNUNET_MESSAGE_TYPE_CADET_KEEPALIVE:
2374 /* Do nothing, connection aleady got updated. */
2375 GNUNET_STATISTICS_update (stats, "# keepalives received", 1, GNUNET_NO);
2378 case GNUNET_MESSAGE_TYPE_CADET_DATA:
2379 /* Don't send hop ACK, wait for client to ACK */
2380 handle_data (t, (struct GNUNET_CADET_Data *) msgh, fwd);
2383 case GNUNET_MESSAGE_TYPE_CADET_DATA_ACK:
2384 handle_data_ack (t, (struct GNUNET_CADET_DataACK *) msgh, fwd);
2387 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_CREATE:
2388 handle_ch_create (t, (struct GNUNET_CADET_ChannelCreate *) msgh);
2391 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_NACK:
2392 handle_ch_nack (t, (struct GNUNET_CADET_ChannelManage *) msgh);
2395 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_ACK:
2396 handle_ch_ack (t, (struct GNUNET_CADET_ChannelManage *) msgh, fwd);
2399 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_DESTROY:
2400 handle_ch_destroy (t, (struct GNUNET_CADET_ChannelManage *) msgh, fwd);
2404 GNUNET_break_op (0);
2405 LOG (GNUNET_ERROR_TYPE_WARNING,
2406 "end-to-end message not known (%u)\n",
2407 ntohs (msgh->type));
2408 GCT_debug (t, GNUNET_ERROR_TYPE_WARNING);
2412 /******************************************************************************/
2413 /******************************** API ***********************************/
2414 /******************************************************************************/
2416 * Decrypt old format and demultiplex by message type. Call appropriate handler
2417 * for a message towards a channel of a local tunnel.
2419 * @param t Tunnel this message came on.
2420 * @param msg Message header.
2423 GCT_handle_encrypted (struct CadetTunnel *t,
2424 const struct GNUNET_MessageHeader *msg)
2426 size_t size = ntohs (msg->size);
2427 size_t payload_size;
2430 uint16_t type = ntohs (msg->type);
2431 struct GNUNET_MessageHeader *msgh;
2434 if (GNUNET_MESSAGE_TYPE_CADET_ENCRYPTED == type)
2436 const struct GNUNET_CADET_Encrypted *emsg;
2438 emsg = (struct GNUNET_CADET_Encrypted *) msg;
2439 payload_size = size - sizeof (struct GNUNET_CADET_Encrypted);
2440 decrypted_size = t_decrypt_and_validate (t, cbuf, &emsg[1], payload_size,
2441 emsg->iv, &emsg->hmac);
2443 else if (GNUNET_MESSAGE_TYPE_CADET_AX == type)
2445 const struct GNUNET_CADET_AX *emsg;
2447 emsg = (struct GNUNET_CADET_AX *) msg;
2448 payload_size = size - sizeof (struct GNUNET_CADET_AX);
2449 decrypted_size = t_ax_decrypt_and_validate (t, cbuf, &emsg[1],
2450 payload_size, &emsg->hmac);
2453 if (-1 == decrypted_size)
2455 GNUNET_break_op (0);
2460 while (off < decrypted_size)
2464 msgh = (struct GNUNET_MessageHeader *) &cbuf[off];
2465 msize = ntohs (msgh->size);
2466 if (msize < sizeof (struct GNUNET_MessageHeader))
2468 GNUNET_break_op (0);
2471 handle_decrypted (t, msgh, GNUNET_SYSERR);
2478 * Demultiplex an encapsulated KX message by message type.
2480 * @param t Tunnel on which the message came.
2481 * @param message Payload of KX message.
2484 GCT_handle_kx (struct CadetTunnel *t,
2485 const struct GNUNET_MessageHeader *message)
2489 type = ntohs (message->type);
2490 LOG (GNUNET_ERROR_TYPE_DEBUG, "kx message received: %s\n", GC_m2s (type));
2493 case GNUNET_MESSAGE_TYPE_CADET_KX_EPHEMERAL:
2494 handle_ephemeral (t, (const struct GNUNET_CADET_KX_Ephemeral *) message);
2497 case GNUNET_MESSAGE_TYPE_CADET_KX_PONG:
2498 handle_pong (t, (const struct GNUNET_CADET_KX_Pong *) message);
2501 case GNUNET_MESSAGE_TYPE_CADET_AX_KX:
2502 handle_kx_ax (t, (const struct GNUNET_CADET_AX_KX *) message);
2506 GNUNET_break_op (0);
2507 LOG (GNUNET_ERROR_TYPE_WARNING, "kx message %s unknown\n", GC_m2s (type));
2513 * Initialize the tunnel subsystem.
2515 * @param c Configuration handle.
2516 * @param key ECC private key, to derive all other keys and do crypto.
2519 GCT_init (const struct GNUNET_CONFIGURATION_Handle *c,
2520 const struct GNUNET_CRYPTO_EddsaPrivateKey *key)
2522 int expected_overhead;
2524 LOG (GNUNET_ERROR_TYPE_DEBUG, "init\n");
2526 expected_overhead = 0;
2527 expected_overhead += sizeof (struct GNUNET_CADET_Encrypted);
2528 expected_overhead += sizeof (struct GNUNET_CADET_Data);
2529 expected_overhead += sizeof (struct GNUNET_CADET_ACK);
2530 GNUNET_assert (GNUNET_CONSTANTS_CADET_P2P_OVERHEAD == expected_overhead);
2533 GNUNET_CONFIGURATION_get_value_number (c, "CADET", "DEFAULT_TTL",
2536 GNUNET_log_config_invalid (GNUNET_ERROR_TYPE_WARNING,
2537 "CADET", "DEFAULT_TTL", "USING DEFAULT");
2541 GNUNET_CONFIGURATION_get_value_time (c, "CADET", "REKEY_PERIOD",
2544 rekey_period = GNUNET_TIME_UNIT_DAYS;
2547 my_private_key = key;
2548 kx_msg.header.size = htons (sizeof (kx_msg));
2549 kx_msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_KX_EPHEMERAL);
2550 kx_msg.purpose.purpose = htonl (GNUNET_SIGNATURE_PURPOSE_CADET_KX);
2551 kx_msg.purpose.size = htonl (ephemeral_purpose_size ());
2552 kx_msg.origin_identity = my_full_id;
2553 rekey_task = GNUNET_SCHEDULER_add_now (&rekey, NULL);
2555 tunnels = GNUNET_CONTAINER_multipeermap_create (128, GNUNET_YES);
2557 ax_key = GNUNET_CRYPTO_ecdhe_key_create();
2562 * Shut down the tunnel subsystem.
2567 if (NULL != rekey_task)
2569 GNUNET_SCHEDULER_cancel (rekey_task);
2572 GNUNET_CONTAINER_multipeermap_iterate (tunnels, &destroy_iterator, NULL);
2573 GNUNET_CONTAINER_multipeermap_destroy (tunnels);
2575 GNUNET_free (ax_key);
2582 * @param destination Peer this tunnel is towards.
2584 struct CadetTunnel *
2585 GCT_new (struct CadetPeer *destination)
2587 struct CadetTunnel *t;
2589 t = GNUNET_new (struct CadetTunnel);
2591 t->peer = destination;
2594 GNUNET_CONTAINER_multipeermap_put (tunnels, GCP_get_id (destination), t,
2595 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_FAST))
2601 t->ax = GNUNET_new (struct CadetTunnelAxolotl);
2607 * Change the tunnel's connection state.
2609 * @param t Tunnel whose connection state to change.
2610 * @param cstate New connection state.
2613 GCT_change_cstate (struct CadetTunnel* t, enum CadetTunnelCState cstate)
2617 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel %s cstate %s => %s\n",
2618 GCP_2s (t->peer), cstate2s (t->cstate), cstate2s (cstate));
2619 if (myid != GCP_get_short_id (t->peer) &&
2620 CADET_TUNNEL_READY != t->cstate &&
2621 CADET_TUNNEL_READY == cstate)
2624 if (CADET_TUNNEL_KEY_OK == t->estate)
2626 LOG (GNUNET_ERROR_TYPE_DEBUG, " cstate triggered send queued data\n");
2627 send_queued_data (t);
2629 else if (CADET_TUNNEL_KEY_UNINITIALIZED == t->estate)
2631 LOG (GNUNET_ERROR_TYPE_DEBUG, " cstate triggered rekey\n");
2632 if (NULL != t->rekey_task)
2633 GNUNET_SCHEDULER_cancel (t->rekey_task);
2635 rekey_tunnel (t, NULL);
2640 if (CADET_TUNNEL_READY == cstate
2641 && CONNECTIONS_PER_TUNNEL <= GCT_count_connections (t))
2643 LOG (GNUNET_ERROR_TYPE_DEBUG, " cstate triggered stop dht\n");
2644 GCP_stop_search (t->peer);
2650 * Change the tunnel encryption state.
2652 * @param t Tunnel whose encryption state to change, or NULL.
2653 * @param state New encryption state.
2656 GCT_change_estate (struct CadetTunnel* t, enum CadetTunnelEState state)
2658 enum CadetTunnelEState old;
2665 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel %s estate was %s\n",
2666 GCP_2s (t->peer), estate2s (old));
2667 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel %s estate is now %s\n",
2668 GCP_2s (t->peer), estate2s (t->estate));
2670 /* Send queued data if enc state changes to OK */
2671 if (myid != GCP_get_short_id (t->peer) &&
2672 CADET_TUNNEL_KEY_OK != old && CADET_TUNNEL_KEY_OK == t->estate)
2674 send_queued_data (t);
2680 * @brief Check if tunnel has too many connections, and remove one if necessary.
2682 * Currently this means the newest connection, unless it is a direct one.
2683 * Implemented as a task to avoid freeing a connection that is in the middle
2684 * of being created/processed.
2686 * @param cls Closure (Tunnel to check).
2687 * @param tc Task context.
2690 trim_connections (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
2692 struct CadetTunnel *t = cls;
2694 t->trim_connections_task = NULL;
2696 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
2699 if (GCT_count_connections (t) > 2 * CONNECTIONS_PER_TUNNEL)
2701 struct CadetTConnection *iter;
2702 struct CadetTConnection *c;
2704 for (c = iter = t->connection_head; NULL != iter; iter = iter->next)
2706 if ((iter->created.abs_value_us > c->created.abs_value_us)
2707 && GNUNET_NO == GCC_is_direct (iter->c))
2714 LOG (GNUNET_ERROR_TYPE_DEBUG, "Too many connections on tunnel %s\n",
2716 LOG (GNUNET_ERROR_TYPE_DEBUG, "Destroying connection %s\n",
2729 * Add a connection to a tunnel.
2732 * @param c Connection.
2735 GCT_add_connection (struct CadetTunnel *t, struct CadetConnection *c)
2737 struct CadetTConnection *aux;
2739 GNUNET_assert (NULL != c);
2741 LOG (GNUNET_ERROR_TYPE_DEBUG, "add connection %s\n", GCC_2s (c));
2742 LOG (GNUNET_ERROR_TYPE_DEBUG, " to tunnel %s\n", GCT_2s (t));
2743 for (aux = t->connection_head; aux != NULL; aux = aux->next)
2747 aux = GNUNET_new (struct CadetTConnection);
2749 aux->created = GNUNET_TIME_absolute_get ();
2751 GNUNET_CONTAINER_DLL_insert (t->connection_head, t->connection_tail, aux);
2753 if (CADET_TUNNEL_SEARCHING == t->cstate)
2754 GCT_change_estate (t, CADET_TUNNEL_WAITING);
2756 if (NULL != t->trim_connections_task)
2757 t->trim_connections_task = GNUNET_SCHEDULER_add_now (&trim_connections, t);
2762 * Remove a connection from a tunnel.
2765 * @param c Connection.
2768 GCT_remove_connection (struct CadetTunnel *t,
2769 struct CadetConnection *c)
2771 struct CadetTConnection *aux;
2772 struct CadetTConnection *next;
2775 LOG (GNUNET_ERROR_TYPE_DEBUG, "Removing connection %s from tunnel %s\n",
2776 GCC_2s (c), GCT_2s (t));
2777 for (aux = t->connection_head; aux != NULL; aux = next)
2782 GNUNET_CONTAINER_DLL_remove (t->connection_head, t->connection_tail, aux);
2787 conns = GCT_count_connections (t);
2789 && NULL == t->destroy_task
2790 && CADET_TUNNEL_SHUTDOWN != t->cstate
2791 && GNUNET_NO == shutting_down)
2793 if (0 == GCT_count_any_connections (t))
2794 GCT_change_cstate (t, CADET_TUNNEL_SEARCHING);
2796 GCT_change_cstate (t, CADET_TUNNEL_WAITING);
2799 /* Start new connections if needed */
2800 if (CONNECTIONS_PER_TUNNEL > conns
2801 && NULL == t->destroy_task
2802 && CADET_TUNNEL_SHUTDOWN != t->cstate
2803 && GNUNET_NO == shutting_down)
2805 LOG (GNUNET_ERROR_TYPE_DEBUG, " too few connections, getting new ones\n");
2806 GCP_connect (t->peer); /* Will change cstate to WAITING when possible */
2810 /* If not marked as ready, no change is needed */
2811 if (CADET_TUNNEL_READY != t->cstate)
2814 /* Check if any connection is ready to maintain cstate */
2815 for (aux = t->connection_head; aux != NULL; aux = aux->next)
2816 if (CADET_CONNECTION_READY == GCC_get_state (aux->c))
2822 * Add a channel to a tunnel.
2825 * @param ch Channel.
2828 GCT_add_channel (struct CadetTunnel *t, struct CadetChannel *ch)
2830 struct CadetTChannel *aux;
2832 GNUNET_assert (NULL != ch);
2834 LOG (GNUNET_ERROR_TYPE_DEBUG, "Adding channel %p to tunnel %p\n", ch, t);
2836 for (aux = t->channel_head; aux != NULL; aux = aux->next)
2838 LOG (GNUNET_ERROR_TYPE_DEBUG, " already there %p\n", aux->ch);
2843 aux = GNUNET_new (struct CadetTChannel);
2845 LOG (GNUNET_ERROR_TYPE_DEBUG, " adding %p to %p\n", aux, t->channel_head);
2846 GNUNET_CONTAINER_DLL_insert_tail (t->channel_head, t->channel_tail, aux);
2848 if (NULL != t->destroy_task)
2850 GNUNET_SCHEDULER_cancel (t->destroy_task);
2851 t->destroy_task = NULL;
2852 LOG (GNUNET_ERROR_TYPE_DEBUG, " undo destroy!\n");
2858 * Remove a channel from a tunnel.
2861 * @param ch Channel.
2864 GCT_remove_channel (struct CadetTunnel *t, struct CadetChannel *ch)
2866 struct CadetTChannel *aux;
2868 LOG (GNUNET_ERROR_TYPE_DEBUG, "Removing channel %p from tunnel %p\n", ch, t);
2869 for (aux = t->channel_head; aux != NULL; aux = aux->next)
2873 LOG (GNUNET_ERROR_TYPE_DEBUG, " found! %s\n", GCCH_2s (ch));
2874 GNUNET_CONTAINER_DLL_remove (t->channel_head, t->channel_tail, aux);
2883 * Search for a channel by global ID.
2885 * @param t Tunnel containing the channel.
2886 * @param chid Public channel number.
2888 * @return channel handler, NULL if doesn't exist
2890 struct CadetChannel *
2891 GCT_get_channel (struct CadetTunnel *t, CADET_ChannelNumber chid)
2893 struct CadetTChannel *iter;
2898 for (iter = t->channel_head; NULL != iter; iter = iter->next)
2900 if (GCCH_get_id (iter->ch) == chid)
2904 return NULL == iter ? NULL : iter->ch;
2909 * @brief Destroy a tunnel and free all resources.
2911 * Should only be called a while after the tunnel has been marked as destroyed,
2912 * in case there is a new channel added to the same peer shortly after marking
2913 * the tunnel. This way we avoid a new public key handshake.
2915 * @param cls Closure (tunnel to destroy).
2916 * @param tc Task context.
2919 delayed_destroy (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
2921 struct CadetTunnel *t = cls;
2922 struct CadetTConnection *iter;
2924 LOG (GNUNET_ERROR_TYPE_DEBUG, "delayed destroying tunnel %p\n", t);
2925 if (0 != (GNUNET_SCHEDULER_REASON_SHUTDOWN & tc->reason))
2927 LOG (GNUNET_ERROR_TYPE_WARNING,
2928 "Not destroying tunnel, due to shutdown. "
2929 "Tunnel at %p should have been freed by GCT_shutdown\n", t);
2932 t->destroy_task = NULL;
2933 t->cstate = CADET_TUNNEL_SHUTDOWN;
2935 for (iter = t->connection_head; NULL != iter; iter = iter->next)
2937 GCC_send_destroy (iter->c);
2944 * Tunnel is empty: destroy it.
2946 * Notifies all connections about the destruction.
2948 * @param t Tunnel to destroy.
2951 GCT_destroy_empty (struct CadetTunnel *t)
2953 if (GNUNET_YES == shutting_down)
2954 return; /* Will be destroyed immediately anyway */
2956 if (NULL != t->destroy_task)
2958 LOG (GNUNET_ERROR_TYPE_WARNING,
2959 "Tunnel %s is already scheduled for destruction. Tunnel debug dump:\n",
2961 GCT_debug (t, GNUNET_ERROR_TYPE_WARNING);
2963 /* should never happen, tunnel can only become empty once, and the
2964 * task identifier should be NO_TASK (cleaned when the tunnel was created
2965 * or became un-empty)
2970 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel %s empty: scheduling destruction\n",
2973 // FIXME make delay a config option
2974 t->destroy_task = GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_MINUTES,
2975 &delayed_destroy, t);
2976 LOG (GNUNET_ERROR_TYPE_DEBUG, "Scheduled destroy of %p as %llu\n",
2977 t, t->destroy_task);
2982 * Destroy tunnel if empty (no more channels).
2984 * @param t Tunnel to destroy if empty.
2987 GCT_destroy_if_empty (struct CadetTunnel *t)
2989 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel %s destroy if empty\n", GCT_2s (t));
2990 if (0 < GCT_count_channels (t))
2993 GCT_destroy_empty (t);
2998 * Destroy the tunnel.
3000 * This function does not generate any warning traffic to clients or peers.
3003 * Cancel messages belonging to this tunnel queued to neighbors.
3004 * Free any allocated resources linked to the tunnel.
3006 * @param t The tunnel to destroy.
3009 GCT_destroy (struct CadetTunnel *t)
3011 struct CadetTConnection *iter_c;
3012 struct CadetTConnection *next_c;
3013 struct CadetTChannel *iter_ch;
3014 struct CadetTChannel *next_ch;
3019 LOG (GNUNET_ERROR_TYPE_DEBUG, "destroying tunnel %s\n", GCP_2s (t->peer));
3021 GNUNET_break (GNUNET_YES ==
3022 GNUNET_CONTAINER_multipeermap_remove (tunnels,
3023 GCP_get_id (t->peer), t));
3025 for (iter_c = t->connection_head; NULL != iter_c; iter_c = next_c)
3027 next_c = iter_c->next;
3028 GCC_destroy (iter_c->c);
3030 for (iter_ch = t->channel_head; NULL != iter_ch; iter_ch = next_ch)
3032 next_ch = iter_ch->next;
3033 GCCH_destroy (iter_ch->ch);
3034 /* Should only happen on shutdown, but it's ok. */
3037 if (NULL != t->destroy_task)
3039 LOG (GNUNET_ERROR_TYPE_DEBUG, "cancelling dest: %llX\n", t->destroy_task);
3040 GNUNET_SCHEDULER_cancel (t->destroy_task);
3041 t->destroy_task = NULL;
3044 if (NULL != t->trim_connections_task)
3046 LOG (GNUNET_ERROR_TYPE_DEBUG, "cancelling trim: %llX\n",
3047 t->trim_connections_task);
3048 GNUNET_SCHEDULER_cancel (t->trim_connections_task);
3049 t->trim_connections_task = NULL;
3052 GNUNET_STATISTICS_update (stats, "# tunnels", -1, GNUNET_NO);
3053 GCP_set_tunnel (t->peer, NULL);
3055 if (NULL != t->rekey_task)
3057 GNUNET_SCHEDULER_cancel (t->rekey_task);
3058 t->rekey_task = NULL;
3060 if (NULL != t->kx_ctx)
3062 if (NULL != t->kx_ctx->finish_task)
3063 GNUNET_SCHEDULER_cancel (t->kx_ctx->finish_task);
3064 GNUNET_free (t->kx_ctx);
3071 * @brief Use the given path for the tunnel.
3072 * Update the next and prev hops (and RCs).
3073 * (Re)start the path refresh in case the tunnel is locally owned.
3075 * @param t Tunnel to update.
3076 * @param p Path to use.
3078 * @return Connection created.
3080 struct CadetConnection *
3081 GCT_use_path (struct CadetTunnel *t, struct CadetPeerPath *p)
3083 struct CadetConnection *c;
3084 struct GNUNET_CADET_Hash cid;
3085 unsigned int own_pos;
3087 if (NULL == t || NULL == p)
3093 if (CADET_TUNNEL_SHUTDOWN == t->cstate)
3099 for (own_pos = 0; own_pos < p->length; own_pos++)
3101 if (p->peers[own_pos] == myid)
3104 if (own_pos >= p->length)
3106 GNUNET_break_op (0);
3110 GNUNET_CRYPTO_random_block (GNUNET_CRYPTO_QUALITY_NONCE, &cid, sizeof (cid));
3111 c = GCC_new (&cid, t, p, own_pos);
3114 /* Path was flawed */
3117 GCT_add_connection (t, c);
3123 * Count all created connections of a tunnel. Not necessarily ready connections!
3125 * @param t Tunnel on which to count.
3127 * @return Number of connections created, either being established or ready.
3130 GCT_count_any_connections (struct CadetTunnel *t)
3132 struct CadetTConnection *iter;
3138 for (count = 0, iter = t->connection_head; NULL != iter; iter = iter->next)
3146 * Count established (ready) connections of a tunnel.
3148 * @param t Tunnel on which to count.
3150 * @return Number of connections.
3153 GCT_count_connections (struct CadetTunnel *t)
3155 struct CadetTConnection *iter;
3161 for (count = 0, iter = t->connection_head; NULL != iter; iter = iter->next)
3162 if (CADET_CONNECTION_READY == GCC_get_state (iter->c))
3170 * Count channels of a tunnel.
3172 * @param t Tunnel on which to count.
3174 * @return Number of channels.
3177 GCT_count_channels (struct CadetTunnel *t)
3179 struct CadetTChannel *iter;
3182 for (count = 0, iter = t->channel_head;
3184 iter = iter->next, count++) /* skip */;
3191 * Get the connectivity state of a tunnel.
3195 * @return Tunnel's connectivity state.
3197 enum CadetTunnelCState
3198 GCT_get_cstate (struct CadetTunnel *t)
3203 return (enum CadetTunnelCState) -1;
3210 * Get the encryption state of a tunnel.
3214 * @return Tunnel's encryption state.
3216 enum CadetTunnelEState
3217 GCT_get_estate (struct CadetTunnel *t)
3222 return (enum CadetTunnelEState) -1;
3228 * Get the maximum buffer space for a tunnel towards a local client.
3232 * @return Biggest buffer space offered by any channel in the tunnel.
3235 GCT_get_channels_buffer (struct CadetTunnel *t)
3237 struct CadetTChannel *iter;
3238 unsigned int buffer;
3239 unsigned int ch_buf;
3241 if (NULL == t->channel_head)
3243 /* Probably getting buffer for a channel create/handshake. */
3244 LOG (GNUNET_ERROR_TYPE_DEBUG, " no channels, allow max\n");
3249 for (iter = t->channel_head; NULL != iter; iter = iter->next)
3251 ch_buf = get_channel_buffer (iter);
3252 if (ch_buf > buffer)
3260 * Get the total buffer space for a tunnel for P2P traffic.
3264 * @return Buffer space offered by all connections in the tunnel.
3267 GCT_get_connections_buffer (struct CadetTunnel *t)
3269 struct CadetTConnection *iter;
3270 unsigned int buffer;
3272 if (GNUNET_NO == is_ready (t))
3274 if (count_queued_data (t) > 3)
3281 for (iter = t->connection_head; NULL != iter; iter = iter->next)
3283 if (GCC_get_state (iter->c) != CADET_CONNECTION_READY)
3287 buffer += get_connection_buffer (iter);
3295 * Get the tunnel's destination.
3299 * @return ID of the destination peer.
3301 const struct GNUNET_PeerIdentity *
3302 GCT_get_destination (struct CadetTunnel *t)
3304 return GCP_get_id (t->peer);
3309 * Get the tunnel's next free global channel ID.
3313 * @return GID of a channel free to use.
3316 GCT_get_next_chid (struct CadetTunnel *t)
3318 CADET_ChannelNumber chid;
3319 CADET_ChannelNumber mask;
3322 /* Set bit 30 depending on the ID relationship. Bit 31 is always 0 for GID.
3323 * If our ID is bigger or loopback tunnel, start at 0, bit 30 = 0
3324 * If peer's ID is bigger, start at 0x4... bit 30 = 1
3326 result = GNUNET_CRYPTO_cmp_peer_identity (&my_full_id, GCP_get_id (t->peer));
3331 t->next_chid |= mask;
3333 while (NULL != GCT_get_channel (t, t->next_chid))
3335 LOG (GNUNET_ERROR_TYPE_DEBUG, "Channel %u exists...\n", t->next_chid);
3336 t->next_chid = (t->next_chid + 1) & ~GNUNET_CADET_LOCAL_CHANNEL_ID_CLI;
3337 t->next_chid |= mask;
3339 chid = t->next_chid;
3340 t->next_chid = (t->next_chid + 1) & ~GNUNET_CADET_LOCAL_CHANNEL_ID_CLI;
3341 t->next_chid |= mask;
3348 * Send ACK on one or more channels due to buffer in connections.
3350 * @param t Channel which has some free buffer space.
3353 GCT_unchoke_channels (struct CadetTunnel *t)
3355 struct CadetTChannel *iter;
3356 unsigned int buffer;
3357 unsigned int channels = GCT_count_channels (t);
3358 unsigned int choked_n;
3359 struct CadetChannel *choked[channels];
3361 LOG (GNUNET_ERROR_TYPE_DEBUG, "GCT_unchoke_channels on %s\n", GCT_2s (t));
3362 LOG (GNUNET_ERROR_TYPE_DEBUG, " head: %p\n", t->channel_head);
3363 if (NULL != t->channel_head)
3364 LOG (GNUNET_ERROR_TYPE_DEBUG, " head ch: %p\n", t->channel_head->ch);
3366 /* Get buffer space */
3367 buffer = GCT_get_connections_buffer (t);
3373 /* Count and remember choked channels */
3375 for (iter = t->channel_head; NULL != iter; iter = iter->next)
3377 if (GNUNET_NO == get_channel_allowed (iter))
3379 choked[choked_n++] = iter->ch;
3383 /* Unchoke random channels */
3384 while (0 < buffer && 0 < choked_n)
3386 unsigned int r = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK,
3388 GCCH_allow_client (choked[r], GCCH_is_origin (choked[r], GNUNET_YES));
3391 choked[r] = choked[choked_n];
3397 * Send ACK on one or more connections due to buffer space to the client.
3399 * Iterates all connections of the tunnel and sends ACKs appropriately.
3404 GCT_send_connection_acks (struct CadetTunnel *t)
3406 struct CadetTConnection *iter;
3409 uint32_t allow_per_connection;
3411 unsigned int buffer;
3413 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel send connection ACKs on %s\n",
3422 if (CADET_TUNNEL_READY != t->cstate)
3425 buffer = GCT_get_channels_buffer (t);
3426 LOG (GNUNET_ERROR_TYPE_DEBUG, " buffer %u\n", buffer);
3428 /* Count connections, how many messages are already allowed */
3429 cs = GCT_count_connections (t);
3430 for (allowed = 0, iter = t->connection_head; NULL != iter; iter = iter->next)
3432 allowed += get_connection_allowed (iter);
3434 LOG (GNUNET_ERROR_TYPE_DEBUG, " allowed %u\n", allowed);
3436 /* Make sure there is no overflow */
3437 if (allowed > buffer)
3440 /* Authorize connections to send more data */
3441 to_allow = buffer - allowed;
3443 for (iter = t->connection_head;
3444 NULL != iter && to_allow > 0;
3447 if (CADET_CONNECTION_READY != GCC_get_state (iter->c)
3448 || get_connection_allowed (iter) > 64 / 3)
3452 allow_per_connection = to_allow/cs;
3453 to_allow -= allow_per_connection;
3455 GCC_allow (iter->c, allow_per_connection,
3456 GCC_is_origin (iter->c, GNUNET_NO));
3461 /* Since we don't allow if it's allowed to send 64/3, this can happen. */
3462 LOG (GNUNET_ERROR_TYPE_DEBUG, " reminding to_allow: %u\n", to_allow);
3468 * Cancel a previously sent message while it's in the queue.
3470 * ONLY can be called before the continuation given to the send function
3471 * is called. Once the continuation is called, the message is no longer in the
3474 * @param q Handle to the queue.
3477 GCT_cancel (struct CadetTunnelQueue *q)
3482 /* tun_message_sent() will be called and free q */
3484 else if (NULL != q->tqd)
3486 unqueue_data (q->tqd);
3488 if (NULL != q->cont)
3489 q->cont (q->cont_cls, NULL, q, 0, 0);
3500 * Sends an already built message on a tunnel, encrypting it and
3501 * choosing the best connection if not provided.
3503 * @param message Message to send. Function modifies it.
3504 * @param t Tunnel on which this message is transmitted.
3505 * @param c Connection to use (autoselect if NULL).
3506 * @param force Force the tunnel to take the message (buffer overfill).
3507 * @param cont Continuation to call once message is really sent.
3508 * @param cont_cls Closure for @c cont.
3510 * @return Handle to cancel message. NULL if @c cont is NULL.
3512 struct CadetTunnelQueue *
3513 GCT_send_prebuilt_message (const struct GNUNET_MessageHeader *message,
3514 struct CadetTunnel *t, struct CadetConnection *c,
3515 int force, GCT_sent cont, void *cont_cls)
3517 return send_prebuilt_message (message, t, c, force, cont, cont_cls, NULL);
3521 * Sends an already built and encrypted message on a tunnel, choosing the best
3522 * connection. Useful for re-queueing messages queued on a destroyed connection.
3524 * @param message Message to send. Function modifies it.
3525 * @param t Tunnel on which this message is transmitted.
3528 GCT_resend_message (const struct GNUNET_MessageHeader *message,
3529 struct CadetTunnel *t)
3531 struct CadetConnection *c;
3534 c = tunnel_get_connection (t);
3537 /* TODO queue in tunnel, marked as encrypted */
3538 LOG (GNUNET_ERROR_TYPE_DEBUG, "No connection available, dropping.\n");
3541 fwd = GCC_is_origin (c, GNUNET_YES);
3542 GNUNET_break (NULL == GCC_send_prebuilt_message (message, 0, 0, c, fwd,
3543 GNUNET_YES, NULL, NULL));
3548 * Is the tunnel directed towards the local peer?
3552 * @return #GNUNET_YES if it is loopback.
3555 GCT_is_loopback (const struct CadetTunnel *t)
3557 return (myid == GCP_get_short_id (t->peer));
3562 * Is the tunnel this path already?
3567 * @return #GNUNET_YES a connection uses this path.
3570 GCT_is_path_used (const struct CadetTunnel *t, const struct CadetPeerPath *p)
3572 struct CadetTConnection *iter;
3574 for (iter = t->connection_head; NULL != iter; iter = iter->next)
3575 if (path_equivalent (GCC_get_path (iter->c), p))
3583 * Get a cost of a path for a tunnel considering existing connections.
3586 * @param path Candidate path.
3588 * @return Cost of the path (path length + number of overlapping nodes)
3591 GCT_get_path_cost (const struct CadetTunnel *t,
3592 const struct CadetPeerPath *path)
3594 struct CadetTConnection *iter;
3595 const struct CadetPeerPath *aux;
3596 unsigned int overlap;
3604 GNUNET_assert (NULL != t);
3606 for (i = 0; i < path->length; i++)
3608 for (iter = t->connection_head; NULL != iter; iter = iter->next)
3610 aux = GCC_get_path (iter->c);
3614 for (j = 0; j < aux->length; j++)
3616 if (path->peers[i] == aux->peers[j])
3624 return path->length + overlap;
3629 * Get the static string for the peer this tunnel is directed.
3633 * @return Static string the destination peer's ID.
3636 GCT_2s (const struct CadetTunnel *t)
3641 return GCP_2s (t->peer);
3645 /******************************************************************************/
3646 /***************************** INFO/DEBUG *******************************/
3647 /******************************************************************************/
3650 * Log all possible info about the tunnel state.
3652 * @param t Tunnel to debug.
3653 * @param level Debug level to use.
3656 GCT_debug (const struct CadetTunnel *t, enum GNUNET_ErrorType level)
3658 struct CadetTChannel *iterch;
3659 struct CadetTConnection *iterc;
3662 do_log = GNUNET_get_log_call_status (level & (~GNUNET_ERROR_TYPE_BULK),
3664 __FILE__, __FUNCTION__, __LINE__);
3668 LOG2 (level, "TTT DEBUG TUNNEL TOWARDS %s\n", GCT_2s (t));
3669 LOG2 (level, "TTT cstate %s, estate %s\n",
3670 cstate2s (t->cstate), estate2s (t->estate));
3671 LOG2 (level, "TTT kx_ctx %p, rekey_task %u, finish task %u\n",
3672 t->kx_ctx, t->rekey_task, t->kx_ctx ? t->kx_ctx->finish_task : 0);
3673 #if DUMP_KEYS_TO_STDERR
3674 LOG2 (level, "TTT my EPHM\t %s\n",
3675 GNUNET_h2s ((struct GNUNET_HashCode *) &kx_msg.ephemeral_key));
3676 LOG2 (level, "TTT peers EPHM:\t %s\n",
3677 GNUNET_h2s ((struct GNUNET_HashCode *) &t->peers_ephemeral_key));
3678 LOG2 (level, "TTT ENC key:\t %s\n",
3679 GNUNET_h2s ((struct GNUNET_HashCode *) &t->e_key));
3680 LOG2 (level, "TTT DEC key:\t %s\n",
3681 GNUNET_h2s ((struct GNUNET_HashCode *) &t->d_key));
3684 LOG2 (level, "TTT OLD ENC key:\t %s\n",
3685 GNUNET_h2s ((struct GNUNET_HashCode *) &t->kx_ctx->e_key_old));
3686 LOG2 (level, "TTT OLD DEC key:\t %s\n",
3687 GNUNET_h2s ((struct GNUNET_HashCode *) &t->kx_ctx->d_key_old));
3690 LOG2 (level, "TTT tq_head %p, tq_tail %p\n", t->tq_head, t->tq_tail);
3691 LOG2 (level, "TTT destroy %u\n", t->destroy_task);
3693 LOG2 (level, "TTT channels:\n");
3694 for (iterch = t->channel_head; NULL != iterch; iterch = iterch->next)
3696 LOG2 (level, "TTT - %s\n", GCCH_2s (iterch->ch));
3699 LOG2 (level, "TTT connections:\n");
3700 for (iterc = t->connection_head; NULL != iterc; iterc = iterc->next)
3702 GCC_debug (iterc->c, level);
3705 LOG2 (level, "TTT DEBUG TUNNEL END\n");
3710 * Iterate all tunnels.
3712 * @param iter Iterator.
3713 * @param cls Closure for @c iter.
3716 GCT_iterate_all (GNUNET_CONTAINER_PeerMapIterator iter, void *cls)
3718 GNUNET_CONTAINER_multipeermap_iterate (tunnels, iter, cls);
3723 * Count all tunnels.
3725 * @return Number of tunnels to remote peers kept by this peer.
3728 GCT_count_all (void)
3730 return GNUNET_CONTAINER_multipeermap_size (tunnels);
3735 * Iterate all connections of a tunnel.
3737 * @param t Tunnel whose connections to iterate.
3738 * @param iter Iterator.
3739 * @param cls Closure for @c iter.
3742 GCT_iterate_connections (struct CadetTunnel *t, GCT_conn_iter iter, void *cls)
3744 struct CadetTConnection *ct;
3746 for (ct = t->connection_head; NULL != ct; ct = ct->next)
3752 * Iterate all channels of a tunnel.
3754 * @param t Tunnel whose channels to iterate.
3755 * @param iter Iterator.
3756 * @param cls Closure for @c iter.
3759 GCT_iterate_channels (struct CadetTunnel *t, GCT_chan_iter iter, void *cls)
3761 struct CadetTChannel *cht;
3763 for (cht = t->channel_head; NULL != cht; cht = cht->next)
3764 iter (cls, cht->ch);