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 * Generate a new key with a HMAC mechanism from the existing chain key.
855 * @param ax Axolotl context.
856 * @param key[out] Derived key.
857 * @param source Source key material (data to HMAC).
858 * @param len Length of @a source.
861 t_ax_hmac_hash (struct CadetTunnelAxolotl *ax,
862 struct GNUNET_CRYPTO_SymmetricSessionKey *key,
863 void *source, unsigned int len)
865 static const char ctx[] = "axolotl key derivation";
866 struct GNUNET_CRYPTO_AuthKey auth_key;
867 struct GNUNET_HashCode hash;
869 GNUNET_CRYPTO_hmac_derive_key (&auth_key, &ax->CKs,
872 GNUNET_CRYPTO_hmac (&auth_key, source, len, &hash);
873 GNUNET_CRYPTO_kdf (key, sizeof (*key),
875 &hash, sizeof (hash));
880 * Encrypt data with the tunnel key.
882 * @param t Tunnel whose key to use.
883 * @param dst Destination for the encrypted data.
884 * @param src Source of the plaintext. Can overlap with @c dst.
885 * @param size Size of the plaintext.
887 * @return Size of the encrypted data.
890 t_ax_encrypt (struct CadetTunnel *t, void *dst, const void *src, size_t size)
892 struct GNUNET_CRYPTO_SymmetricSessionKey MK;
893 struct GNUNET_CRYPTO_SymmetricInitializationVector iv;
894 struct CadetTunnelAxolotl *ax;
897 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_ax_encrypt start\n");
901 if (GNUNET_YES == ax->ratchet_flag)
903 /* Advance ratchet */
906 t_ax_hmac_hash (ax, &MK, "0", 1);
907 GNUNET_CRYPTO_symmetric_derive_iv (&iv, &MK, NULL, 0, NULL);
909 #if DUMP_KEYS_TO_STDERR
910 LOG (GNUNET_ERROR_TYPE_INFO, " ENC with key %s\n",
911 GNUNET_h2s ((struct GNUNET_HashCode *) &MK));
914 out_size = GNUNET_CRYPTO_symmetric_encrypt (src, size, &MK, &iv, dst);
916 t_ax_hmac_hash (ax, &ax->CKs, "1", 1);
918 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_ax_encrypt end\n");
925 * Decrypt and verify data with the appropriate tunnel key.
927 * @param key 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.
933 * @return Size of the decrypted data, -1 if an error was encountered.
936 decrypt (const struct GNUNET_CRYPTO_SymmetricSessionKey *key,
937 void *dst, const void *src, size_t size, uint32_t iv)
939 struct GNUNET_CRYPTO_SymmetricInitializationVector siv;
942 LOG (GNUNET_ERROR_TYPE_DEBUG, " decrypt start\n");
943 LOG (GNUNET_ERROR_TYPE_DEBUG, " decrypt iv\n");
944 GNUNET_CRYPTO_symmetric_derive_iv (&siv, key, &iv, sizeof (iv), NULL);
945 LOG (GNUNET_ERROR_TYPE_DEBUG, " decrypt iv done\n");
946 out_size = GNUNET_CRYPTO_symmetric_decrypt (src, size, key, &siv, dst);
947 LOG (GNUNET_ERROR_TYPE_DEBUG, " decrypt end\n");
954 * Decrypt and verify data with the most recent tunnel key.
956 * @param t Tunnel whose key to use.
957 * @param dst Destination for the plaintext.
958 * @param src Source of the encrypted data. Can overlap with @c dst.
959 * @param size Size of the encrypted data.
960 * @param iv Initialization Vector to use.
962 * @return Size of the decrypted data, -1 if an error was encountered.
965 t_decrypt (struct CadetTunnel *t, void *dst, const void *src,
966 size_t size, uint32_t iv)
970 #if DUMP_KEYS_TO_STDERR
971 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_decrypt with %s\n",
972 GNUNET_h2s ((struct GNUNET_HashCode *) &t->d_key));
974 if (CADET_TUNNEL_KEY_UNINITIALIZED == t->estate)
976 GNUNET_STATISTICS_update (stats, "# non decryptable data", 1, GNUNET_NO);
977 LOG (GNUNET_ERROR_TYPE_WARNING,
978 "got data on %s without a valid key\n",
980 GCT_debug (t, GNUNET_ERROR_TYPE_WARNING);
984 out_size = decrypt (&t->d_key, dst, src, size, iv);
991 * Decrypt and verify data with the appropriate tunnel key and verify that the
992 * data has not been altered since it was sent by the remote peer.
994 * @param t Tunnel whose key to use.
995 * @param dst Destination for the plaintext.
996 * @param src Source of the encrypted data. Can overlap with @c dst.
997 * @param size Size of the encrypted data.
998 * @param iv Initialization Vector to use.
999 * @param msg_hmac HMAC of the message, cannot be NULL.
1001 * @return Size of the decrypted data, -1 if an error was encountered.
1004 t_decrypt_and_validate (struct CadetTunnel *t,
1005 void *dst, const void *src,
1006 size_t size, uint32_t iv,
1007 const struct GNUNET_CADET_Hash *msg_hmac)
1009 struct GNUNET_CRYPTO_SymmetricSessionKey *key;
1010 struct GNUNET_CADET_Hash hmac;
1013 /* Try primary (newest) key */
1015 decrypted_size = decrypt (key, dst, src, size, iv);
1016 t_hmac (src, size, iv, key, &hmac);
1017 if (0 == memcmp (msg_hmac, &hmac, sizeof (hmac)))
1018 return decrypted_size;
1020 /* If no key exchange is going on, we just failed. */
1021 if (NULL == t->kx_ctx)
1023 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
1024 "Failed checksum validation on tunnel %s with no KX\n",
1026 GNUNET_STATISTICS_update (stats, "# wrong HMAC no KX", 1, GNUNET_NO);
1030 /* Try secondary key, from previous KX period. */
1031 key = &t->kx_ctx->d_key_old;
1032 decrypted_size = decrypt (key, dst, src, size, iv);
1033 t_hmac (src, size, iv, key, &hmac);
1034 if (0 == memcmp (msg_hmac, &hmac, sizeof (hmac)))
1035 return decrypted_size;
1037 /* Hail Mary, try tertiary, key, in case of parallel re-keys. */
1038 key = &t->kx_ctx->d_key_old2;
1039 decrypted_size = decrypt (key, dst, src, size, iv);
1040 t_hmac (src, size, iv, key, &hmac);
1041 if (0 == memcmp (msg_hmac, &hmac, sizeof (hmac)))
1042 return decrypted_size;
1044 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
1045 "Failed checksum validation on tunnel %s with KX\n",
1047 GNUNET_STATISTICS_update (stats, "# wrong HMAC with KX", 1, GNUNET_NO);
1052 * Decrypt and verify data with the appropriate tunnel key and verify that the
1053 * data has not been altered since it was sent by the remote peer.
1055 * @param t Tunnel whose key to use.
1056 * @param dst Destination for the plaintext.
1057 * @param src Source of the encrypted data. Can overlap with @c dst.
1058 * @param size Size of the encrypted data.
1059 * @param msg_hmac HMAC of the message, cannot be NULL.
1061 * @return Size of the decrypted data, -1 if an error was encountered.
1064 t_ax_decrypt_and_validate (struct CadetTunnel *t,
1065 void *dst, const void *src, size_t size,
1066 const struct GNUNET_CADET_Hash *msg_hmac)
1068 struct CadetTunnelAxolotl *ax;
1083 * Create key material by doing ECDH on the local and remote ephemeral keys.
1085 * @param key_material Where to store the key material.
1086 * @param ephemeral_key Peer's public ephemeral key.
1089 derive_key_material (struct GNUNET_HashCode *key_material,
1090 const struct GNUNET_CRYPTO_EcdhePublicKey *ephemeral_key)
1093 GNUNET_CRYPTO_ecc_ecdh (my_ephemeral_key,
1103 * Create a symmetic key from the identities of both ends and the key material
1106 * @param key Destination for the generated key.
1107 * @param sender ID of the peer that will encrypt with @c key.
1108 * @param receiver ID of the peer that will decrypt with @c key.
1109 * @param key_material Hash created with ECDH with the ephemeral keys.
1112 derive_symmertic (struct GNUNET_CRYPTO_SymmetricSessionKey *key,
1113 const struct GNUNET_PeerIdentity *sender,
1114 const struct GNUNET_PeerIdentity *receiver,
1115 const struct GNUNET_HashCode *key_material)
1117 const char salt[] = "CADET kx salt";
1119 GNUNET_CRYPTO_kdf (key, sizeof (struct GNUNET_CRYPTO_SymmetricSessionKey),
1120 salt, sizeof (salt),
1121 key_material, sizeof (struct GNUNET_HashCode),
1122 sender, sizeof (struct GNUNET_PeerIdentity),
1123 receiver, sizeof (struct GNUNET_PeerIdentity),
1129 * Derive the tunnel's keys using our own and the peer's ephemeral keys.
1131 * @param t Tunnel for which to create the keys.
1134 create_keys (struct CadetTunnel *t)
1136 struct GNUNET_HashCode km;
1138 derive_key_material (&km, &t->peers_ephemeral_key);
1139 derive_symmertic (&t->e_key, &my_full_id, GCP_get_id (t->peer), &km);
1140 derive_symmertic (&t->d_key, GCP_get_id (t->peer), &my_full_id, &km);
1141 #if DUMP_KEYS_TO_STDERR
1142 LOG (GNUNET_ERROR_TYPE_INFO, "ME: %s\n",
1143 GNUNET_h2s ((struct GNUNET_HashCode *) &kx_msg.ephemeral_key));
1144 LOG (GNUNET_ERROR_TYPE_INFO, "PE: %s\n",
1145 GNUNET_h2s ((struct GNUNET_HashCode *) &t->peers_ephemeral_key));
1146 LOG (GNUNET_ERROR_TYPE_INFO, "KM: %s\n", GNUNET_h2s (&km));
1147 LOG (GNUNET_ERROR_TYPE_INFO, "EK: %s\n",
1148 GNUNET_h2s ((struct GNUNET_HashCode *) &t->e_key));
1149 LOG (GNUNET_ERROR_TYPE_INFO, "DK: %s\n",
1150 GNUNET_h2s ((struct GNUNET_HashCode *) &t->d_key));
1156 * Create a new Key eXchange context for the tunnel.
1158 * If the old keys were verified, keep them for old traffic. Create a new KX
1159 * timestamp and a new nonce.
1161 * @param t Tunnel for which to create the KX ctx.
1164 create_kx_ctx (struct CadetTunnel *t)
1166 LOG (GNUNET_ERROR_TYPE_INFO, " new kx ctx for %s\n", GCT_2s (t));
1168 if (NULL != t->kx_ctx)
1170 if (NULL != t->kx_ctx->finish_task)
1172 LOG (GNUNET_ERROR_TYPE_INFO, " resetting exisiting finish task\n");
1173 GNUNET_SCHEDULER_cancel (t->kx_ctx->finish_task);
1174 t->kx_ctx->finish_task = NULL;
1179 t->kx_ctx = GNUNET_new (struct CadetTunnelKXCtx);
1180 t->kx_ctx->challenge = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE,
1184 if (CADET_TUNNEL_KEY_OK == t->estate)
1186 LOG (GNUNET_ERROR_TYPE_INFO, " backing up keys\n");
1187 t->kx_ctx->d_key_old = t->d_key;
1188 t->kx_ctx->e_key_old = t->e_key;
1191 LOG (GNUNET_ERROR_TYPE_INFO, " old keys not valid, not saving\n");
1192 t->kx_ctx->rekey_start_time = GNUNET_TIME_absolute_get ();
1198 * @brief Finish the Key eXchange and destroy the old keys.
1200 * @param cls Closure (Tunnel for which to finish the KX).
1201 * @param tc Task context.
1204 finish_kx (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
1206 struct CadetTunnel *t = cls;
1208 LOG (GNUNET_ERROR_TYPE_INFO, "finish KX for %s\n", GCT_2s (t));
1210 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
1212 LOG (GNUNET_ERROR_TYPE_INFO, " shutdown\n");
1216 GNUNET_free (t->kx_ctx);
1222 * Destroy a Key eXchange context for the tunnel. This function only schedules
1223 * the destruction, the freeing of the memory (and clearing of old key material)
1224 * happens after a delay!
1226 * @param t Tunnel whose KX ctx to destroy.
1229 destroy_kx_ctx (struct CadetTunnel *t)
1231 struct GNUNET_TIME_Relative delay;
1233 if (NULL == t->kx_ctx || NULL != t->kx_ctx->finish_task)
1236 if (is_key_null (&t->kx_ctx->e_key_old))
1238 t->kx_ctx->finish_task = GNUNET_SCHEDULER_add_now (finish_kx, t);
1242 delay = GNUNET_TIME_relative_divide (rekey_period, 4);
1243 delay = GNUNET_TIME_relative_min (delay, GNUNET_TIME_UNIT_MINUTES);
1245 t->kx_ctx->finish_task = GNUNET_SCHEDULER_add_delayed (delay, finish_kx, t);
1251 * Pick a connection on which send the next data message.
1253 * @param t Tunnel on which to send the message.
1255 * @return The connection on which to send the next message.
1257 static struct CadetConnection *
1258 tunnel_get_connection (struct CadetTunnel *t)
1260 struct CadetTConnection *iter;
1261 struct CadetConnection *best;
1263 unsigned int lowest_q;
1265 LOG (GNUNET_ERROR_TYPE_DEBUG, "tunnel_get_connection %s\n", GCT_2s (t));
1267 lowest_q = UINT_MAX;
1268 for (iter = t->connection_head; NULL != iter; iter = iter->next)
1270 LOG (GNUNET_ERROR_TYPE_DEBUG, " connection %s: %u\n",
1271 GCC_2s (iter->c), GCC_get_state (iter->c));
1272 if (CADET_CONNECTION_READY == GCC_get_state (iter->c))
1274 qn = GCC_get_qn (iter->c, GCC_is_origin (iter->c, GNUNET_YES));
1275 LOG (GNUNET_ERROR_TYPE_DEBUG, " q_n %u, \n", qn);
1283 LOG (GNUNET_ERROR_TYPE_DEBUG, " selected: connection %s\n", GCC_2s (best));
1289 * Callback called when a queued message is sent.
1291 * Calculates the average time and connection packet tracking.
1293 * @param cls Closure (TunnelQueue handle).
1294 * @param c Connection this message was on.
1295 * @param q Connection queue handle (unused).
1296 * @param type Type of message sent.
1297 * @param fwd Was this a FWD going message?
1298 * @param size Size of the message.
1301 tun_message_sent (void *cls,
1302 struct CadetConnection *c,
1303 struct CadetConnectionQueue *q,
1304 uint16_t type, int fwd, size_t size)
1306 struct CadetTunnelQueue *qt = cls;
1307 struct CadetTunnel *t;
1309 LOG (GNUNET_ERROR_TYPE_DEBUG, "tun_message_sent\n");
1311 GNUNET_assert (NULL != qt->cont);
1312 t = NULL == c ? NULL : GCC_get_tunnel (c);
1313 qt->cont (qt->cont_cls, t, qt, type, size);
1319 count_queued_data (const struct CadetTunnel *t)
1321 struct CadetTunnelDelayed *iter;
1324 for (count = 0, iter = t->tq_head; iter != NULL; iter = iter->next)
1331 * Delete a queued message: either was sent or the channel was destroyed
1332 * before the tunnel's key exchange had a chance to finish.
1334 * @param tqd Delayed queue handle.
1337 unqueue_data (struct CadetTunnelDelayed *tqd)
1339 GNUNET_CONTAINER_DLL_remove (tqd->t->tq_head, tqd->t->tq_tail, tqd);
1345 * Cache a message to be sent once tunnel is online.
1347 * @param t Tunnel to hold the message.
1348 * @param msg Message itself (copy will be made).
1350 static struct CadetTunnelDelayed *
1351 queue_data (struct CadetTunnel *t, const struct GNUNET_MessageHeader *msg)
1353 struct CadetTunnelDelayed *tqd;
1354 uint16_t size = ntohs (msg->size);
1356 LOG (GNUNET_ERROR_TYPE_DEBUG, "queue data on Tunnel %s\n", GCT_2s (t));
1358 if (GNUNET_YES == is_ready (t))
1364 tqd = GNUNET_malloc (sizeof (struct CadetTunnelDelayed) + size);
1367 memcpy (&tqd[1], msg, size);
1368 GNUNET_CONTAINER_DLL_insert_tail (t->tq_head, t->tq_tail, tqd);
1374 * Sends an already built message on a tunnel, encrypting it and
1375 * choosing the best connection.
1377 * @param message Message to send. Function modifies it.
1378 * @param t Tunnel on which this message is transmitted.
1379 * @param c Connection to use (autoselect if NULL).
1380 * @param force Force the tunnel to take the message (buffer overfill).
1381 * @param cont Continuation to call once message is really sent.
1382 * @param cont_cls Closure for @c cont.
1383 * @param existing_q In case this a transmission of previously queued data,
1384 * this should be TunnelQueue given to the client.
1387 * @return Handle to cancel message.
1388 * NULL if @c cont is NULL or an error happens and message is dropped.
1390 static struct CadetTunnelQueue *
1391 send_prebuilt_message (const struct GNUNET_MessageHeader *message,
1392 struct CadetTunnel *t, struct CadetConnection *c,
1393 int force, GCT_sent cont, void *cont_cls,
1394 struct CadetTunnelQueue *existing_q)
1396 struct CadetTunnelQueue *tq;
1397 struct GNUNET_CADET_Encrypted *msg;
1398 size_t size = ntohs (message->size);
1399 char cbuf[sizeof (struct GNUNET_CADET_Encrypted) + size];
1406 LOG (GNUNET_ERROR_TYPE_DEBUG, "GMT Send on Tunnel %s\n", GCT_2s (t));
1408 if (GNUNET_NO == is_ready (t))
1410 struct CadetTunnelDelayed *tqd;
1411 /* A non null existing_q indicates sending of queued data.
1412 * Should only happen after tunnel becomes ready.
1414 GNUNET_assert (NULL == existing_q);
1415 tqd = queue_data (t, message);
1418 tq = GNUNET_new (struct CadetTunnelQueue);
1422 tq->cont_cls = cont_cls;
1426 GNUNET_assert (GNUNET_NO == GCT_is_loopback (t));
1428 iv = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX);
1429 msg = (struct GNUNET_CADET_Encrypted *) cbuf;
1430 msg->header.type = htons (GNUNET_MESSAGE_TYPE_CADET_ENCRYPTED);
1433 if (CADET_Axolotl == t->enc_type)
1434 esize = t_ax_encrypt (t, &msg[1], message, size);
1436 esize = t_encrypt (t, &msg[1], message, size, iv, GNUNET_NO);
1437 GNUNET_assert (esize == size);
1438 t_hmac (&msg[1], size, iv, select_key (t), &msg->hmac);
1439 msg->header.size = htons (sizeof (struct GNUNET_CADET_Encrypted) + size);
1442 c = tunnel_get_connection (t);
1445 /* Why is tunnel 'ready'? Should have been queued! */
1446 if (NULL != t->destroy_task)
1449 GCT_debug (t, GNUNET_ERROR_TYPE_WARNING);
1451 return NULL; /* Drop... */
1455 type = ntohs (message->type);
1458 case GNUNET_MESSAGE_TYPE_CADET_DATA:
1459 case GNUNET_MESSAGE_TYPE_CADET_DATA_ACK:
1460 if (GNUNET_MESSAGE_TYPE_CADET_DATA == type)
1461 mid = ntohl (((struct GNUNET_CADET_Data *) message)->mid);
1463 mid = ntohl (((struct GNUNET_CADET_DataACK *) message)->mid);
1465 case GNUNET_MESSAGE_TYPE_CADET_KEEPALIVE:
1466 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_CREATE:
1467 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_DESTROY:
1468 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_ACK:
1469 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_NACK:
1470 msg->cid = *GCC_get_id (c);
1471 msg->ttl = htonl (default_ttl);
1475 LOG (GNUNET_ERROR_TYPE_ERROR, "type %s not valid\n", GC_m2s (type));
1477 LOG (GNUNET_ERROR_TYPE_DEBUG, "type %s\n", GC_m2s (type));
1479 fwd = GCC_is_origin (c, GNUNET_YES);
1483 GNUNET_break (NULL == GCC_send_prebuilt_message (&msg->header, type, mid, c,
1484 fwd, force, NULL, NULL));
1487 if (NULL == existing_q)
1489 tq = GNUNET_new (struct CadetTunnelQueue); /* FIXME valgrind: leak*/
1496 tq->cq = GCC_send_prebuilt_message (&msg->header, type, mid, c, fwd, force,
1497 &tun_message_sent, tq);
1498 GNUNET_assert (NULL != tq->cq);
1500 tq->cont_cls = cont_cls;
1507 * Send all cached messages that we can, tunnel is online.
1509 * @param t Tunnel that holds the messages. Cannot be loopback.
1512 send_queued_data (struct CadetTunnel *t)
1514 struct CadetTunnelDelayed *tqd;
1515 struct CadetTunnelDelayed *next;
1518 LOG (GNUNET_ERROR_TYPE_INFO, "Send queued data, tunnel %s\n", GCT_2s (t));
1520 if (GCT_is_loopback (t))
1526 if (GNUNET_NO == is_ready (t))
1528 LOG (GNUNET_ERROR_TYPE_DEBUG, " not ready yet: %s/%s\n",
1529 estate2s (t->estate), cstate2s (t->cstate));
1533 room = GCT_get_connections_buffer (t);
1534 LOG (GNUNET_ERROR_TYPE_DEBUG, " buffer space: %u\n", room);
1535 LOG (GNUNET_ERROR_TYPE_DEBUG, " tq head: %p\n", t->tq_head);
1536 for (tqd = t->tq_head; NULL != tqd && room > 0; tqd = next)
1538 LOG (GNUNET_ERROR_TYPE_DEBUG, " sending queued data\n");
1541 send_prebuilt_message ((struct GNUNET_MessageHeader *) &tqd[1],
1542 tqd->t, NULL, GNUNET_YES,
1543 NULL != tqd->tq ? tqd->tq->cont : NULL,
1544 NULL != tqd->tq ? tqd->tq->cont_cls : NULL,
1548 LOG (GNUNET_ERROR_TYPE_DEBUG, "GCT_send_queued_data end\n", GCP_2s (t->peer));
1553 * Callback called when a queued message is sent.
1555 * @param cls Closure.
1556 * @param c Connection this message was on.
1557 * @param type Type of message sent.
1558 * @param fwd Was this a FWD going message?
1559 * @param size Size of the message.
1562 ephm_sent (void *cls,
1563 struct CadetConnection *c,
1564 struct CadetConnectionQueue *q,
1565 uint16_t type, int fwd, size_t size)
1567 struct CadetTunnel *t = cls;
1568 LOG (GNUNET_ERROR_TYPE_DEBUG, "ephm_sent %s\n", GC_m2s (type));
1573 * Callback called when a queued message is sent.
1575 * @param cls Closure.
1576 * @param c Connection this message was on.
1577 * @param type Type of message sent.
1578 * @param fwd Was this a FWD going message?
1579 * @param size Size of the message.
1582 pong_sent (void *cls,
1583 struct CadetConnection *c,
1584 struct CadetConnectionQueue *q,
1585 uint16_t type, int fwd, size_t size)
1587 struct CadetTunnel *t = cls;
1588 LOG (GNUNET_ERROR_TYPE_DEBUG, "pong_sent %s\n", GC_m2s (type));
1594 * Sends key exchange message on a tunnel, choosing the best connection.
1595 * Should not be called on loopback tunnels.
1597 * @param t Tunnel on which this message is transmitted.
1598 * @param message Message to send. Function modifies it.
1600 * @return Handle to the message in the connection queue.
1602 static struct CadetConnectionQueue *
1603 send_kx (struct CadetTunnel *t,
1604 const struct GNUNET_MessageHeader *message)
1606 struct CadetConnection *c;
1607 struct GNUNET_CADET_KX *msg;
1608 size_t size = ntohs (message->size);
1609 char cbuf[sizeof (struct GNUNET_CADET_KX) + size];
1614 LOG (GNUNET_ERROR_TYPE_DEBUG, "GMT KX on Tunnel %s\n", GCT_2s (t));
1616 /* Avoid loopback. */
1617 if (GCT_is_loopback (t))
1619 LOG (GNUNET_ERROR_TYPE_DEBUG, " loopback!\n");
1623 type = ntohs (message->type);
1625 /* Even if tunnel is "being destroyed", send anyway.
1626 * Could be a response to a rekey initiated by remote peer,
1627 * who is trying to create a new channel!
1630 /* Must have a connection, or be looking for one. */
1631 if (NULL == t->connection_head)
1633 LOG (GNUNET_ERROR_TYPE_DEBUG, "%s while no connection\n", GC_m2s (type));
1634 if (CADET_TUNNEL_SEARCHING != t->cstate)
1637 GCT_debug (t, GNUNET_ERROR_TYPE_ERROR);
1638 GCP_debug (t->peer, GNUNET_ERROR_TYPE_ERROR);
1643 msg = (struct GNUNET_CADET_KX *) cbuf;
1644 msg->header.type = htons (GNUNET_MESSAGE_TYPE_CADET_KX);
1645 msg->header.size = htons (sizeof (struct GNUNET_CADET_KX) + size);
1646 c = tunnel_get_connection (t);
1649 if (NULL == t->destroy_task
1650 && CADET_TUNNEL_READY == t->cstate)
1653 GCT_debug (t, GNUNET_ERROR_TYPE_ERROR);
1659 case GNUNET_MESSAGE_TYPE_CADET_KX_EPHEMERAL:
1660 GNUNET_assert (NULL == t->ephm_h);
1662 memcpy (&msg[1], message, size);
1664 case GNUNET_MESSAGE_TYPE_CADET_KX_PONG:
1665 GNUNET_assert (NULL == t->pong_h);
1667 memcpy (&msg[1], message, size);
1671 LOG (GNUNET_ERROR_TYPE_DEBUG, "unkown type %s\n", GC_m2s (type));
1675 fwd = GCC_is_origin (c, GNUNET_YES);
1677 return GCC_send_prebuilt_message (&msg->header, type, 0, c,
1684 * Send the ephemeral key on a tunnel.
1686 * @param t Tunnel on which to send the key.
1689 send_ephemeral (struct CadetTunnel *t)
1691 LOG (GNUNET_ERROR_TYPE_INFO, "===> EPHM for %s\n", GCT_2s (t));
1692 if (NULL != t->ephm_h)
1694 LOG (GNUNET_ERROR_TYPE_INFO, " already queued\n");
1698 kx_msg.sender_status = htonl (t->estate);
1699 kx_msg.iv = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX);
1700 kx_msg.nonce = t->kx_ctx->challenge;
1701 LOG (GNUNET_ERROR_TYPE_DEBUG, " send nonce c %u\n", kx_msg.nonce);
1702 t_encrypt (t, &kx_msg.nonce, &kx_msg.nonce,
1703 ping_encryption_size(), kx_msg.iv, GNUNET_YES);
1704 LOG (GNUNET_ERROR_TYPE_DEBUG, " send nonce e %u\n", kx_msg.nonce);
1705 t->ephm_h = send_kx (t, &kx_msg.header);
1710 * Send a pong message on a tunnel.
1712 * @param t Tunnel on which to send the pong.
1713 * @param challenge Value sent in the ping that we have to send back.
1716 send_pong (struct CadetTunnel *t, uint32_t challenge)
1718 struct GNUNET_CADET_KX_Pong msg;
1720 LOG (GNUNET_ERROR_TYPE_INFO, "===> PONG for %s\n", GCT_2s (t));
1721 if (NULL != t->pong_h)
1723 LOG (GNUNET_ERROR_TYPE_INFO, " already queued\n");
1726 msg.header.size = htons (sizeof (msg));
1727 msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_KX_PONG);
1728 msg.iv = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX);
1729 msg.nonce = challenge;
1730 LOG (GNUNET_ERROR_TYPE_DEBUG, " sending %u\n", msg.nonce);
1731 t_encrypt (t, &msg.nonce, &msg.nonce,
1732 sizeof (msg.nonce), msg.iv, GNUNET_YES);
1733 LOG (GNUNET_ERROR_TYPE_DEBUG, " e sending %u\n", msg.nonce);
1735 t->pong_h = send_kx (t, &msg.header);
1740 * Initiate a rekey with the remote peer.
1742 * @param cls Closure (tunnel).
1743 * @param tc TaskContext.
1746 rekey_tunnel (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
1748 struct CadetTunnel *t = cls;
1750 t->rekey_task = NULL;
1752 LOG (GNUNET_ERROR_TYPE_INFO, "Re-key Tunnel %s\n", GCT_2s (t));
1753 if (NULL != tc && 0 != (GNUNET_SCHEDULER_REASON_SHUTDOWN & tc->reason))
1756 GNUNET_assert (NULL != t->kx_ctx);
1757 struct GNUNET_TIME_Relative duration;
1759 duration = GNUNET_TIME_absolute_get_duration (t->kx_ctx->rekey_start_time);
1760 LOG (GNUNET_ERROR_TYPE_DEBUG, " kx started %s ago\n",
1761 GNUNET_STRINGS_relative_time_to_string (duration, GNUNET_YES));
1763 // FIXME make duration of old keys configurable
1764 if (duration.rel_value_us >= GNUNET_TIME_UNIT_MINUTES.rel_value_us)
1766 LOG (GNUNET_ERROR_TYPE_DEBUG, " deleting old keys\n");
1767 memset (&t->kx_ctx->d_key_old, 0, sizeof (t->kx_ctx->d_key_old));
1768 memset (&t->kx_ctx->e_key_old, 0, sizeof (t->kx_ctx->e_key_old));
1775 case CADET_TUNNEL_KEY_UNINITIALIZED:
1776 GCT_change_estate (t, CADET_TUNNEL_KEY_SENT);
1779 case CADET_TUNNEL_KEY_SENT:
1782 case CADET_TUNNEL_KEY_OK:
1784 * - state should have changed during rekey_iterator
1785 * - task should have been canceled at pong_handle
1788 GCT_change_estate (t, CADET_TUNNEL_KEY_REKEY);
1791 case CADET_TUNNEL_KEY_PING:
1792 case CADET_TUNNEL_KEY_REKEY:
1796 LOG (GNUNET_ERROR_TYPE_DEBUG, "Unexpected state %u\n", t->estate);
1799 // FIXME exponential backoff
1800 struct GNUNET_TIME_Relative delay;
1802 delay = GNUNET_TIME_relative_divide (rekey_period, 16);
1803 delay = GNUNET_TIME_relative_min (delay, REKEY_WAIT);
1804 LOG (GNUNET_ERROR_TYPE_DEBUG, " next call in %s\n",
1805 GNUNET_STRINGS_relative_time_to_string (delay, GNUNET_YES));
1806 t->rekey_task = GNUNET_SCHEDULER_add_delayed (delay, &rekey_tunnel, t);
1811 * Our ephemeral key has changed, create new session key on all tunnels.
1813 * Each tunnel will start the Key Exchange with a random delay between
1814 * 0 and number_of_tunnels*100 milliseconds, so there are 10 key exchanges
1815 * per second, on average.
1817 * @param cls Closure (size of the hashmap).
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 rekey_iterator (void *cls,
1825 const struct GNUNET_PeerIdentity *key,
1828 struct CadetTunnel *t = value;
1829 struct GNUNET_TIME_Relative delay;
1830 long n = (long) cls;
1833 if (NULL != t->rekey_task)
1836 if (GNUNET_YES == GCT_is_loopback (t))
1839 r = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK, (uint32_t) n * 100);
1840 delay = GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MILLISECONDS, r);
1841 t->rekey_task = GNUNET_SCHEDULER_add_delayed (delay, &rekey_tunnel, t);
1843 GCT_change_estate (t, CADET_TUNNEL_KEY_REKEY);
1850 * Create a new ephemeral key and key message, schedule next rekeying.
1852 * @param cls Closure (unused).
1853 * @param tc TaskContext.
1856 rekey (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
1858 struct GNUNET_TIME_Absolute time;
1863 if (0 != (GNUNET_SCHEDULER_REASON_SHUTDOWN & tc->reason))
1866 GNUNET_free_non_null (my_ephemeral_key);
1867 my_ephemeral_key = GNUNET_CRYPTO_ecdhe_key_create ();
1869 time = GNUNET_TIME_absolute_get ();
1870 kx_msg.creation_time = GNUNET_TIME_absolute_hton (time);
1871 time = GNUNET_TIME_absolute_add (time, rekey_period);
1872 time = GNUNET_TIME_absolute_add (time, GNUNET_TIME_UNIT_MINUTES);
1873 kx_msg.expiration_time = GNUNET_TIME_absolute_hton (time);
1874 GNUNET_CRYPTO_ecdhe_key_get_public (my_ephemeral_key, &kx_msg.ephemeral_key);
1875 LOG (GNUNET_ERROR_TYPE_INFO, "GLOBAL RE-KEY, NEW EPHM: %s\n",
1876 GNUNET_h2s ((struct GNUNET_HashCode *) &kx_msg.ephemeral_key));
1878 GNUNET_assert (GNUNET_OK ==
1879 GNUNET_CRYPTO_eddsa_sign (my_private_key,
1881 &kx_msg.signature));
1883 n = (long) GNUNET_CONTAINER_multipeermap_size (tunnels);
1884 GNUNET_CONTAINER_multipeermap_iterate (tunnels, &rekey_iterator, (void *) n);
1886 rekey_task = GNUNET_SCHEDULER_add_delayed (rekey_period, &rekey, NULL);
1891 * Called only on shutdown, destroy every tunnel.
1893 * @param cls Closure (unused).
1894 * @param key Current public key.
1895 * @param value Value in the hash map (tunnel).
1897 * @return #GNUNET_YES, so we should continue to iterate,
1900 destroy_iterator (void *cls,
1901 const struct GNUNET_PeerIdentity *key,
1904 struct CadetTunnel *t = value;
1906 LOG (GNUNET_ERROR_TYPE_DEBUG, "GCT_shutdown destroying tunnel at %p\n", t);
1913 * Notify remote peer that we don't know a channel he is talking about,
1914 * probably CHANNEL_DESTROY was missed.
1916 * @param t Tunnel on which to notify.
1917 * @param gid ID of the channel.
1920 send_channel_destroy (struct CadetTunnel *t, unsigned int gid)
1922 struct GNUNET_CADET_ChannelManage msg;
1924 msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_CHANNEL_DESTROY);
1925 msg.header.size = htons (sizeof (msg));
1926 msg.chid = htonl (gid);
1928 LOG (GNUNET_ERROR_TYPE_DEBUG,
1929 "WARNING destroying unknown channel %u on tunnel %s\n",
1931 send_prebuilt_message (&msg.header, t, NULL, GNUNET_YES, NULL, NULL, NULL);
1936 * Demultiplex data per channel and call appropriate channel handler.
1938 * @param t Tunnel on which the data came.
1939 * @param msg Data message.
1940 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
1941 * #GNUNET_YES if message is FWD on the respective channel (loopback)
1942 * #GNUNET_NO if message is BCK on the respective channel (loopback)
1943 * #GNUNET_SYSERR if message on a one-ended channel (remote)
1946 handle_data (struct CadetTunnel *t,
1947 const struct GNUNET_CADET_Data *msg,
1950 struct CadetChannel *ch;
1954 size = ntohs (msg->header.size);
1956 sizeof (struct GNUNET_CADET_Data) +
1957 sizeof (struct GNUNET_MessageHeader))
1962 LOG (GNUNET_ERROR_TYPE_DEBUG, " payload of type %s\n",
1963 GC_m2s (ntohs (msg[1].header.type)));
1966 ch = GCT_get_channel (t, ntohl (msg->chid));
1969 GNUNET_STATISTICS_update (stats, "# data on unknown channel",
1971 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel 0x%X unknown\n",
1973 send_channel_destroy (t, ntohl (msg->chid));
1977 GCCH_handle_data (ch, msg, fwd);
1982 * Demultiplex data ACKs per channel and update appropriate channel buffer info.
1984 * @param t Tunnel on which the DATA ACK came.
1985 * @param msg DATA ACK message.
1986 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
1987 * #GNUNET_YES if message is FWD on the respective channel (loopback)
1988 * #GNUNET_NO if message is BCK on the respective channel (loopback)
1989 * #GNUNET_SYSERR if message on a one-ended channel (remote)
1992 handle_data_ack (struct CadetTunnel *t,
1993 const struct GNUNET_CADET_DataACK *msg,
1996 struct CadetChannel *ch;
2000 size = ntohs (msg->header.size);
2001 if (size != sizeof (struct GNUNET_CADET_DataACK))
2008 ch = GCT_get_channel (t, ntohl (msg->chid));
2011 GNUNET_STATISTICS_update (stats, "# data ack on unknown channel",
2013 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel %u unknown\n",
2018 GCCH_handle_data_ack (ch, msg, fwd);
2023 * Handle channel create.
2025 * @param t Tunnel on which the data came.
2026 * @param msg Data message.
2029 handle_ch_create (struct CadetTunnel *t,
2030 const struct GNUNET_CADET_ChannelCreate *msg)
2032 struct CadetChannel *ch;
2036 size = ntohs (msg->header.size);
2037 if (size != sizeof (struct GNUNET_CADET_ChannelCreate))
2044 ch = GCT_get_channel (t, ntohl (msg->chid));
2045 if (NULL != ch && ! GCT_is_loopback (t))
2047 /* Probably a retransmission, safe to ignore */
2048 LOG (GNUNET_ERROR_TYPE_DEBUG, " already exists...\n");
2050 ch = GCCH_handle_create (t, msg);
2052 GCT_add_channel (t, ch);
2058 * Handle channel NACK: check correctness and call channel handler for NACKs.
2060 * @param t Tunnel on which the NACK came.
2061 * @param msg NACK message.
2064 handle_ch_nack (struct CadetTunnel *t,
2065 const struct GNUNET_CADET_ChannelManage *msg)
2067 struct CadetChannel *ch;
2071 size = ntohs (msg->header.size);
2072 if (size != sizeof (struct GNUNET_CADET_ChannelManage))
2079 ch = GCT_get_channel (t, ntohl (msg->chid));
2082 GNUNET_STATISTICS_update (stats, "# channel NACK on unknown channel",
2084 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel %u unknown\n",
2089 GCCH_handle_nack (ch);
2094 * Handle a CHANNEL ACK (SYNACK/ACK).
2096 * @param t Tunnel on which the CHANNEL ACK came.
2097 * @param msg CHANNEL ACK message.
2098 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
2099 * #GNUNET_YES if message is FWD on the respective channel (loopback)
2100 * #GNUNET_NO if message is BCK on the respective channel (loopback)
2101 * #GNUNET_SYSERR if message on a one-ended channel (remote)
2104 handle_ch_ack (struct CadetTunnel *t,
2105 const struct GNUNET_CADET_ChannelManage *msg,
2108 struct CadetChannel *ch;
2112 size = ntohs (msg->header.size);
2113 if (size != sizeof (struct GNUNET_CADET_ChannelManage))
2120 ch = GCT_get_channel (t, ntohl (msg->chid));
2123 GNUNET_STATISTICS_update (stats, "# channel ack on unknown channel",
2125 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel %u unknown\n",
2130 GCCH_handle_ack (ch, msg, fwd);
2135 * Handle a channel destruction message.
2137 * @param t Tunnel on which the message came.
2138 * @param msg Channel destroy message.
2139 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
2140 * #GNUNET_YES if message is FWD on the respective channel (loopback)
2141 * #GNUNET_NO if message is BCK on the respective channel (loopback)
2142 * #GNUNET_SYSERR if message on a one-ended channel (remote)
2145 handle_ch_destroy (struct CadetTunnel *t,
2146 const struct GNUNET_CADET_ChannelManage *msg,
2149 struct CadetChannel *ch;
2153 size = ntohs (msg->header.size);
2154 if (size != sizeof (struct GNUNET_CADET_ChannelManage))
2161 ch = GCT_get_channel (t, ntohl (msg->chid));
2164 /* Probably a retransmission, safe to ignore */
2168 GCCH_handle_destroy (ch, msg, fwd);
2173 * Create a new Axolotl ephemeral (ratchet) key.
2178 new_ephemeral (struct CadetTunnel *t)
2180 GNUNET_free_non_null (t->ax->DHRs);
2181 t->ax->DHRs = GNUNET_CRYPTO_ecdhe_key_create();
2186 * Free Axolotl data.
2191 destroy_ax (struct CadetTunnel *t)
2196 if (NULL != t->ax->DHRs)
2197 GNUNET_free (t->ax->DHRs);
2198 GNUNET_free (t->ax);
2205 * The peer's ephemeral key has changed: update the symmetrical keys.
2207 * @param t Tunnel this message came on.
2208 * @param msg Key eXchange message.
2211 handle_ephemeral (struct CadetTunnel *t,
2212 const struct GNUNET_CADET_KX_Ephemeral *msg)
2214 LOG (GNUNET_ERROR_TYPE_INFO, "<=== EPHM for %s\n", GCT_2s (t));
2216 if (GNUNET_OK != check_ephemeral (t, msg))
2218 GNUNET_break_op (0);
2222 /* If we get a proper OTR-style ephemeral, fallback to old crypto. */
2226 t->enc_type = CADET_Fallback;
2230 * If the key is different from what we know, derive the new E/D keys.
2231 * Else destroy the rekey ctx (duplicate EPHM after successful KX).
2233 if (0 != memcmp (&t->peers_ephemeral_key, &msg->ephemeral_key,
2234 sizeof (msg->ephemeral_key)))
2236 #if DUMP_KEYS_TO_STDERR
2237 LOG (GNUNET_ERROR_TYPE_INFO, "OLD: %s\n",
2238 GNUNET_h2s ((struct GNUNET_HashCode *) &t->peers_ephemeral_key));
2239 LOG (GNUNET_ERROR_TYPE_INFO, "NEW: %s\n",
2240 GNUNET_h2s ((struct GNUNET_HashCode *) &msg->ephemeral_key));
2242 t->peers_ephemeral_key = msg->ephemeral_key;
2246 if (CADET_TUNNEL_KEY_OK == t->estate)
2248 GCT_change_estate (t, CADET_TUNNEL_KEY_REKEY);
2250 if (NULL != t->rekey_task)
2251 GNUNET_SCHEDULER_cancel (t->rekey_task);
2252 t->rekey_task = GNUNET_SCHEDULER_add_now (rekey_tunnel, t);
2254 if (CADET_TUNNEL_KEY_SENT == t->estate)
2256 LOG (GNUNET_ERROR_TYPE_DEBUG, " our key was sent, sending challenge\n");
2258 GCT_change_estate (t, CADET_TUNNEL_KEY_PING);
2261 if (CADET_TUNNEL_KEY_UNINITIALIZED != ntohl(msg->sender_status))
2265 LOG (GNUNET_ERROR_TYPE_DEBUG, " recv nonce e %u\n", msg->nonce);
2266 t_decrypt (t, &nonce, &msg->nonce, ping_encryption_size (), msg->iv);
2267 LOG (GNUNET_ERROR_TYPE_DEBUG, " recv nonce c %u\n", nonce);
2268 send_pong (t, nonce);
2274 * Peer has answer to our challenge.
2275 * If answer is successful, consider the key exchange finished and clean
2276 * up all related state.
2278 * @param t Tunnel this message came on.
2279 * @param msg Key eXchange Pong message.
2282 handle_pong (struct CadetTunnel *t, const struct GNUNET_CADET_KX_Pong *msg)
2286 LOG (GNUNET_ERROR_TYPE_INFO, "<=== PONG for %s\n", GCT_2s (t));
2287 if (NULL == t->rekey_task)
2289 GNUNET_STATISTICS_update (stats, "# duplicate PONG messages", 1, GNUNET_NO);
2292 if (NULL == t->kx_ctx)
2294 GNUNET_STATISTICS_update (stats, "# stray PONG messages", 1, GNUNET_NO);
2298 t_decrypt (t, &challenge, &msg->nonce, sizeof (uint32_t), msg->iv);
2299 if (challenge != t->kx_ctx->challenge)
2301 LOG (GNUNET_ERROR_TYPE_WARNING, "Wrong PONG challenge on %s\n", GCT_2s (t));
2302 LOG (GNUNET_ERROR_TYPE_DEBUG, "PONG: %u (e: %u). Expected: %u.\n",
2303 challenge, msg->nonce, t->kx_ctx->challenge);
2307 GNUNET_SCHEDULER_cancel (t->rekey_task);
2308 t->rekey_task = NULL;
2310 /* Don't free the old keys right away, but after a delay.
2311 * Rationale: the KX could have happened over a very fast connection,
2312 * with payload traffic still signed with the old key stuck in a slower
2314 * Don't keep the keys longer than 1/4 the rekey period, and no longer than
2318 GCT_change_estate (t, CADET_TUNNEL_KEY_OK);
2330 * WARNING! DANGER! Do not use this if you don't know what you are doing!
2331 * Ask Christian Grothoff, Werner Koch, Dan Bernstein and $GOD!
2333 * Transform a private EdDSA key (peer's key) into a key usable by DH.
2335 * @param k Private EdDSA key to transform.
2337 * @return Private key for EC Diffie-Hellman.
2339 static const struct GNUNET_CRYPTO_EcdhePrivateKey *
2340 get_private_ecdhe_from_eddsa (const struct GNUNET_CRYPTO_EddsaPrivateKey *k)
2342 return (const struct GNUNET_CRYPTO_EcdhePrivateKey *) k;
2347 * WARNING! DANGER! Do not use this if you don't know what you are doing!
2348 * Ask Christian Grothoff, Werner Koch, Dan Bernstein and $GOD!
2350 * Transform a public EdDSA key (peer's key) into a key usable by DH.
2352 * @param k Public EdDSA key to transform (peer's ID).
2354 * @return Public key for EC Diffie-Hellman.
2356 static const struct GNUNET_CRYPTO_EcdhePublicKey *
2357 get_public_ecdhe_from_id (const struct GNUNET_PeerIdentity *id)
2359 return (const struct GNUNET_CRYPTO_EcdhePublicKey *) id;
2364 * Handle Axolotl handshake.
2366 * @param t Tunnel this message came on.
2367 * @param msg Key eXchange Pong message.
2370 handle_kx_ax (struct CadetTunnel *t, const struct GNUNET_CADET_AX_KX *msg)
2372 struct GNUNET_CRYPTO_EcdhePublicKey eph;
2373 struct CadetTunnelAxolotl *ax;
2374 struct GNUNET_HashCode key_material[3];
2375 struct GNUNET_CRYPTO_SymmetricSessionKey keys[5];
2376 const struct GNUNET_CRYPTO_EcdhePublicKey *pub;
2377 const struct GNUNET_CRYPTO_EcdhePrivateKey *priv;
2378 const char salt[] = "CADET Axolotl salt";
2379 const struct GNUNET_PeerIdentity *pid;
2384 /* Something is wrong if ax is NULL. Whose fault it is? */
2385 GNUNET_break_op (CADET_Fallback == t->enc_type);
2386 GNUNET_break (CADET_Axolotl == t->enc_type);
2390 pid = GCT_get_destination (t);
2391 if (0 > GNUNET_CRYPTO_cmp_peer_identity (&my_full_id, pid))
2392 is_alice = GNUNET_YES;
2393 else if (0 > GNUNET_CRYPTO_cmp_peer_identity (&my_full_id, pid))
2394 is_alice = GNUNET_NO;
2397 GNUNET_break_op (0);
2402 ax->DHRr = msg->ratchet_key;
2404 GNUNET_CRYPTO_ecdhe_key_get_public (ax->DHRs, &eph);
2405 if (0 != memcmp (&eph, &msg->peers_key, sizeof (eph)))
2412 if (GNUNET_YES == is_alice)
2414 priv = get_private_ecdhe_from_eddsa (my_private_key); /* A */
2415 pub = &msg->ephemeral_key; /* B0 */
2419 priv = ax->DHRs; /* B0 */
2420 pub = get_public_ecdhe_from_id (pid); /* A */
2422 GNUNET_CRYPTO_ecc_ecdh (priv, pub, &key_material[0]);
2425 if (GNUNET_YES == is_alice)
2427 priv = ax->DHRs; /* A0 */
2428 pub = get_public_ecdhe_from_id (pid); /* B */
2432 priv = get_private_ecdhe_from_eddsa (my_private_key); /* B */
2433 pub = &msg->ephemeral_key; /* A0 */
2435 GNUNET_CRYPTO_ecc_ecdh (priv, pub, &key_material[1]);
2438 priv = ax->DHRs; /* A0 or B0 */
2439 pub = &msg->ephemeral_key; /* B0 or A0 */
2440 GNUNET_CRYPTO_ecc_ecdh (priv, pub, &key_material[2]);
2443 GNUNET_CRYPTO_kdf (keys, sizeof (keys),
2444 salt, sizeof (salt),
2445 key_material, sizeof (key_material), NULL);
2448 if (GNUNET_YES == is_alice)
2454 ax->ratchet_flag = GNUNET_YES;
2462 ax->ratchet_flag = GNUNET_NO;
2468 * Demultiplex by message type and call appropriate handler for a message
2469 * towards a channel of a local tunnel.
2471 * @param t Tunnel this message came on.
2472 * @param msgh Message header.
2473 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
2474 * #GNUNET_YES if message is FWD on the respective channel (loopback)
2475 * #GNUNET_NO if message is BCK on the respective channel (loopback)
2476 * #GNUNET_SYSERR if message on a one-ended channel (remote)
2479 handle_decrypted (struct CadetTunnel *t,
2480 const struct GNUNET_MessageHeader *msgh,
2485 type = ntohs (msgh->type);
2486 LOG (GNUNET_ERROR_TYPE_INFO, "<=== %s on %s\n", GC_m2s (type), GCT_2s (t));
2490 case GNUNET_MESSAGE_TYPE_CADET_KEEPALIVE:
2491 /* Do nothing, connection aleady got updated. */
2492 GNUNET_STATISTICS_update (stats, "# keepalives received", 1, GNUNET_NO);
2495 case GNUNET_MESSAGE_TYPE_CADET_DATA:
2496 /* Don't send hop ACK, wait for client to ACK */
2497 handle_data (t, (struct GNUNET_CADET_Data *) msgh, fwd);
2500 case GNUNET_MESSAGE_TYPE_CADET_DATA_ACK:
2501 handle_data_ack (t, (struct GNUNET_CADET_DataACK *) msgh, fwd);
2504 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_CREATE:
2505 handle_ch_create (t, (struct GNUNET_CADET_ChannelCreate *) msgh);
2508 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_NACK:
2509 handle_ch_nack (t, (struct GNUNET_CADET_ChannelManage *) msgh);
2512 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_ACK:
2513 handle_ch_ack (t, (struct GNUNET_CADET_ChannelManage *) msgh, fwd);
2516 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_DESTROY:
2517 handle_ch_destroy (t, (struct GNUNET_CADET_ChannelManage *) msgh, fwd);
2521 GNUNET_break_op (0);
2522 LOG (GNUNET_ERROR_TYPE_WARNING,
2523 "end-to-end message not known (%u)\n",
2524 ntohs (msgh->type));
2525 GCT_debug (t, GNUNET_ERROR_TYPE_WARNING);
2529 /******************************************************************************/
2530 /******************************** API ***********************************/
2531 /******************************************************************************/
2533 * Decrypt old format and demultiplex by message type. Call appropriate handler
2534 * for a message towards a channel of a local tunnel.
2536 * @param t Tunnel this message came on.
2537 * @param msg Message header.
2540 GCT_handle_encrypted (struct CadetTunnel *t,
2541 const struct GNUNET_MessageHeader *msg)
2543 size_t size = ntohs (msg->size);
2544 size_t payload_size;
2547 uint16_t type = ntohs (msg->type);
2548 struct GNUNET_MessageHeader *msgh;
2551 if (GNUNET_MESSAGE_TYPE_CADET_ENCRYPTED == type)
2553 const struct GNUNET_CADET_Encrypted *emsg;
2555 emsg = (struct GNUNET_CADET_Encrypted *) msg;
2556 payload_size = size - sizeof (struct GNUNET_CADET_Encrypted);
2557 decrypted_size = t_decrypt_and_validate (t, cbuf, &emsg[1], payload_size,
2558 emsg->iv, &emsg->hmac);
2560 else if (GNUNET_MESSAGE_TYPE_CADET_AX == type)
2562 const struct GNUNET_CADET_AX *emsg;
2564 emsg = (struct GNUNET_CADET_AX *) msg;
2565 payload_size = size - sizeof (struct GNUNET_CADET_AX);
2566 decrypted_size = t_ax_decrypt_and_validate (t, cbuf, &emsg[1],
2567 payload_size, &emsg->hmac);
2570 if (-1 == decrypted_size)
2572 GNUNET_break_op (0);
2577 while (off < decrypted_size)
2581 msgh = (struct GNUNET_MessageHeader *) &cbuf[off];
2582 msize = ntohs (msgh->size);
2583 if (msize < sizeof (struct GNUNET_MessageHeader))
2585 GNUNET_break_op (0);
2588 handle_decrypted (t, msgh, GNUNET_SYSERR);
2595 * Demultiplex an encapsulated KX message by message type.
2597 * @param t Tunnel on which the message came.
2598 * @param message Payload of KX message.
2601 GCT_handle_kx (struct CadetTunnel *t,
2602 const struct GNUNET_MessageHeader *message)
2606 type = ntohs (message->type);
2607 LOG (GNUNET_ERROR_TYPE_DEBUG, "kx message received: %s\n", GC_m2s (type));
2610 case GNUNET_MESSAGE_TYPE_CADET_KX_EPHEMERAL:
2611 handle_ephemeral (t, (const struct GNUNET_CADET_KX_Ephemeral *) message);
2614 case GNUNET_MESSAGE_TYPE_CADET_KX_PONG:
2615 handle_pong (t, (const struct GNUNET_CADET_KX_Pong *) message);
2618 case GNUNET_MESSAGE_TYPE_CADET_AX_KX:
2619 handle_kx_ax (t, (const struct GNUNET_CADET_AX_KX *) message);
2623 GNUNET_break_op (0);
2624 LOG (GNUNET_ERROR_TYPE_WARNING, "kx message %s unknown\n", GC_m2s (type));
2630 * Initialize the tunnel subsystem.
2632 * @param c Configuration handle.
2633 * @param key ECC private key, to derive all other keys and do crypto.
2636 GCT_init (const struct GNUNET_CONFIGURATION_Handle *c,
2637 const struct GNUNET_CRYPTO_EddsaPrivateKey *key)
2639 int expected_overhead;
2641 LOG (GNUNET_ERROR_TYPE_DEBUG, "init\n");
2643 expected_overhead = 0;
2644 expected_overhead += sizeof (struct GNUNET_CADET_Encrypted);
2645 expected_overhead += sizeof (struct GNUNET_CADET_Data);
2646 expected_overhead += sizeof (struct GNUNET_CADET_ACK);
2647 GNUNET_assert (GNUNET_CONSTANTS_CADET_P2P_OVERHEAD == expected_overhead);
2650 GNUNET_CONFIGURATION_get_value_number (c, "CADET", "DEFAULT_TTL",
2653 GNUNET_log_config_invalid (GNUNET_ERROR_TYPE_WARNING,
2654 "CADET", "DEFAULT_TTL", "USING DEFAULT");
2658 GNUNET_CONFIGURATION_get_value_time (c, "CADET", "REKEY_PERIOD",
2661 rekey_period = GNUNET_TIME_UNIT_DAYS;
2664 my_private_key = key;
2666 kx_msg.header.size = htons (sizeof (kx_msg));
2667 kx_msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_KX_EPHEMERAL);
2668 kx_msg.purpose.purpose = htonl (GNUNET_SIGNATURE_PURPOSE_CADET_KX);
2669 kx_msg.purpose.size = htonl (ephemeral_purpose_size ());
2670 kx_msg.origin_identity = my_full_id;
2671 rekey_task = GNUNET_SCHEDULER_add_now (&rekey, NULL);
2673 tunnels = GNUNET_CONTAINER_multipeermap_create (128, GNUNET_YES);
2678 * Shut down the tunnel subsystem.
2683 if (NULL != rekey_task)
2685 GNUNET_SCHEDULER_cancel (rekey_task);
2688 GNUNET_CONTAINER_multipeermap_iterate (tunnels, &destroy_iterator, NULL);
2689 GNUNET_CONTAINER_multipeermap_destroy (tunnels);
2696 * @param destination Peer this tunnel is towards.
2698 struct CadetTunnel *
2699 GCT_new (struct CadetPeer *destination)
2701 struct CadetTunnel *t;
2703 t = GNUNET_new (struct CadetTunnel);
2705 t->peer = destination;
2708 GNUNET_CONTAINER_multipeermap_put (tunnels, GCP_get_id (destination), t,
2709 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_FAST))
2715 t->ax = GNUNET_new (struct CadetTunnelAxolotl);
2722 * Change the tunnel's connection state.
2724 * @param t Tunnel whose connection state to change.
2725 * @param cstate New connection state.
2728 GCT_change_cstate (struct CadetTunnel* t, enum CadetTunnelCState cstate)
2732 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel %s cstate %s => %s\n",
2733 GCP_2s (t->peer), cstate2s (t->cstate), cstate2s (cstate));
2734 if (myid != GCP_get_short_id (t->peer) &&
2735 CADET_TUNNEL_READY != t->cstate &&
2736 CADET_TUNNEL_READY == cstate)
2739 if (CADET_TUNNEL_KEY_OK == t->estate)
2741 LOG (GNUNET_ERROR_TYPE_DEBUG, " cstate triggered send queued data\n");
2742 send_queued_data (t);
2744 else if (CADET_TUNNEL_KEY_UNINITIALIZED == t->estate)
2746 LOG (GNUNET_ERROR_TYPE_DEBUG, " cstate triggered rekey\n");
2747 if (NULL != t->rekey_task)
2748 GNUNET_SCHEDULER_cancel (t->rekey_task);
2750 rekey_tunnel (t, NULL);
2755 if (CADET_TUNNEL_READY == cstate
2756 && CONNECTIONS_PER_TUNNEL <= GCT_count_connections (t))
2758 LOG (GNUNET_ERROR_TYPE_DEBUG, " cstate triggered stop dht\n");
2759 GCP_stop_search (t->peer);
2765 * Change the tunnel encryption state.
2767 * @param t Tunnel whose encryption state to change, or NULL.
2768 * @param state New encryption state.
2771 GCT_change_estate (struct CadetTunnel* t, enum CadetTunnelEState state)
2773 enum CadetTunnelEState old;
2780 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel %s estate was %s\n",
2781 GCP_2s (t->peer), estate2s (old));
2782 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel %s estate is now %s\n",
2783 GCP_2s (t->peer), estate2s (t->estate));
2785 /* Send queued data if enc state changes to OK */
2786 if (myid != GCP_get_short_id (t->peer) &&
2787 CADET_TUNNEL_KEY_OK != old && CADET_TUNNEL_KEY_OK == t->estate)
2789 send_queued_data (t);
2795 * @brief Check if tunnel has too many connections, and remove one if necessary.
2797 * Currently this means the newest connection, unless it is a direct one.
2798 * Implemented as a task to avoid freeing a connection that is in the middle
2799 * of being created/processed.
2801 * @param cls Closure (Tunnel to check).
2802 * @param tc Task context.
2805 trim_connections (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
2807 struct CadetTunnel *t = cls;
2809 t->trim_connections_task = NULL;
2811 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
2814 if (GCT_count_connections (t) > 2 * CONNECTIONS_PER_TUNNEL)
2816 struct CadetTConnection *iter;
2817 struct CadetTConnection *c;
2819 for (c = iter = t->connection_head; NULL != iter; iter = iter->next)
2821 if ((iter->created.abs_value_us > c->created.abs_value_us)
2822 && GNUNET_NO == GCC_is_direct (iter->c))
2829 LOG (GNUNET_ERROR_TYPE_DEBUG, "Too many connections on tunnel %s\n",
2831 LOG (GNUNET_ERROR_TYPE_DEBUG, "Destroying connection %s\n",
2844 * Add a connection to a tunnel.
2847 * @param c Connection.
2850 GCT_add_connection (struct CadetTunnel *t, struct CadetConnection *c)
2852 struct CadetTConnection *aux;
2854 GNUNET_assert (NULL != c);
2856 LOG (GNUNET_ERROR_TYPE_DEBUG, "add connection %s\n", GCC_2s (c));
2857 LOG (GNUNET_ERROR_TYPE_DEBUG, " to tunnel %s\n", GCT_2s (t));
2858 for (aux = t->connection_head; aux != NULL; aux = aux->next)
2862 aux = GNUNET_new (struct CadetTConnection);
2864 aux->created = GNUNET_TIME_absolute_get ();
2866 GNUNET_CONTAINER_DLL_insert (t->connection_head, t->connection_tail, aux);
2868 if (CADET_TUNNEL_SEARCHING == t->cstate)
2869 GCT_change_estate (t, CADET_TUNNEL_WAITING);
2871 if (NULL != t->trim_connections_task)
2872 t->trim_connections_task = GNUNET_SCHEDULER_add_now (&trim_connections, t);
2877 * Remove a connection from a tunnel.
2880 * @param c Connection.
2883 GCT_remove_connection (struct CadetTunnel *t,
2884 struct CadetConnection *c)
2886 struct CadetTConnection *aux;
2887 struct CadetTConnection *next;
2890 LOG (GNUNET_ERROR_TYPE_DEBUG, "Removing connection %s from tunnel %s\n",
2891 GCC_2s (c), GCT_2s (t));
2892 for (aux = t->connection_head; aux != NULL; aux = next)
2897 GNUNET_CONTAINER_DLL_remove (t->connection_head, t->connection_tail, aux);
2902 conns = GCT_count_connections (t);
2904 && NULL == t->destroy_task
2905 && CADET_TUNNEL_SHUTDOWN != t->cstate
2906 && GNUNET_NO == shutting_down)
2908 if (0 == GCT_count_any_connections (t))
2909 GCT_change_cstate (t, CADET_TUNNEL_SEARCHING);
2911 GCT_change_cstate (t, CADET_TUNNEL_WAITING);
2914 /* Start new connections if needed */
2915 if (CONNECTIONS_PER_TUNNEL > conns
2916 && NULL == t->destroy_task
2917 && CADET_TUNNEL_SHUTDOWN != t->cstate
2918 && GNUNET_NO == shutting_down)
2920 LOG (GNUNET_ERROR_TYPE_DEBUG, " too few connections, getting new ones\n");
2921 GCP_connect (t->peer); /* Will change cstate to WAITING when possible */
2925 /* If not marked as ready, no change is needed */
2926 if (CADET_TUNNEL_READY != t->cstate)
2929 /* Check if any connection is ready to maintain cstate */
2930 for (aux = t->connection_head; aux != NULL; aux = aux->next)
2931 if (CADET_CONNECTION_READY == GCC_get_state (aux->c))
2937 * Add a channel to a tunnel.
2940 * @param ch Channel.
2943 GCT_add_channel (struct CadetTunnel *t, struct CadetChannel *ch)
2945 struct CadetTChannel *aux;
2947 GNUNET_assert (NULL != ch);
2949 LOG (GNUNET_ERROR_TYPE_DEBUG, "Adding channel %p to tunnel %p\n", ch, t);
2951 for (aux = t->channel_head; aux != NULL; aux = aux->next)
2953 LOG (GNUNET_ERROR_TYPE_DEBUG, " already there %p\n", aux->ch);
2958 aux = GNUNET_new (struct CadetTChannel);
2960 LOG (GNUNET_ERROR_TYPE_DEBUG, " adding %p to %p\n", aux, t->channel_head);
2961 GNUNET_CONTAINER_DLL_insert_tail (t->channel_head, t->channel_tail, aux);
2963 if (NULL != t->destroy_task)
2965 GNUNET_SCHEDULER_cancel (t->destroy_task);
2966 t->destroy_task = NULL;
2967 LOG (GNUNET_ERROR_TYPE_DEBUG, " undo destroy!\n");
2973 * Remove a channel from a tunnel.
2976 * @param ch Channel.
2979 GCT_remove_channel (struct CadetTunnel *t, struct CadetChannel *ch)
2981 struct CadetTChannel *aux;
2983 LOG (GNUNET_ERROR_TYPE_DEBUG, "Removing channel %p from tunnel %p\n", ch, t);
2984 for (aux = t->channel_head; aux != NULL; aux = aux->next)
2988 LOG (GNUNET_ERROR_TYPE_DEBUG, " found! %s\n", GCCH_2s (ch));
2989 GNUNET_CONTAINER_DLL_remove (t->channel_head, t->channel_tail, aux);
2998 * Search for a channel by global ID.
3000 * @param t Tunnel containing the channel.
3001 * @param chid Public channel number.
3003 * @return channel handler, NULL if doesn't exist
3005 struct CadetChannel *
3006 GCT_get_channel (struct CadetTunnel *t, CADET_ChannelNumber chid)
3008 struct CadetTChannel *iter;
3013 for (iter = t->channel_head; NULL != iter; iter = iter->next)
3015 if (GCCH_get_id (iter->ch) == chid)
3019 return NULL == iter ? NULL : iter->ch;
3024 * @brief Destroy a tunnel and free all resources.
3026 * Should only be called a while after the tunnel has been marked as destroyed,
3027 * in case there is a new channel added to the same peer shortly after marking
3028 * the tunnel. This way we avoid a new public key handshake.
3030 * @param cls Closure (tunnel to destroy).
3031 * @param tc Task context.
3034 delayed_destroy (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
3036 struct CadetTunnel *t = cls;
3037 struct CadetTConnection *iter;
3039 LOG (GNUNET_ERROR_TYPE_DEBUG, "delayed destroying tunnel %p\n", t);
3040 if (0 != (GNUNET_SCHEDULER_REASON_SHUTDOWN & tc->reason))
3042 LOG (GNUNET_ERROR_TYPE_WARNING,
3043 "Not destroying tunnel, due to shutdown. "
3044 "Tunnel at %p should have been freed by GCT_shutdown\n", t);
3047 t->destroy_task = NULL;
3048 t->cstate = CADET_TUNNEL_SHUTDOWN;
3050 for (iter = t->connection_head; NULL != iter; iter = iter->next)
3052 GCC_send_destroy (iter->c);
3059 * Tunnel is empty: destroy it.
3061 * Notifies all connections about the destruction.
3063 * @param t Tunnel to destroy.
3066 GCT_destroy_empty (struct CadetTunnel *t)
3068 if (GNUNET_YES == shutting_down)
3069 return; /* Will be destroyed immediately anyway */
3071 if (NULL != t->destroy_task)
3073 LOG (GNUNET_ERROR_TYPE_WARNING,
3074 "Tunnel %s is already scheduled for destruction. Tunnel debug dump:\n",
3076 GCT_debug (t, GNUNET_ERROR_TYPE_WARNING);
3078 /* should never happen, tunnel can only become empty once, and the
3079 * task identifier should be NO_TASK (cleaned when the tunnel was created
3080 * or became un-empty)
3085 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel %s empty: scheduling destruction\n",
3088 // FIXME make delay a config option
3089 t->destroy_task = GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_MINUTES,
3090 &delayed_destroy, t);
3091 LOG (GNUNET_ERROR_TYPE_DEBUG, "Scheduled destroy of %p as %llu\n",
3092 t, t->destroy_task);
3097 * Destroy tunnel if empty (no more channels).
3099 * @param t Tunnel to destroy if empty.
3102 GCT_destroy_if_empty (struct CadetTunnel *t)
3104 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel %s destroy if empty\n", GCT_2s (t));
3105 if (0 < GCT_count_channels (t))
3108 GCT_destroy_empty (t);
3113 * Destroy the tunnel.
3115 * This function does not generate any warning traffic to clients or peers.
3118 * Cancel messages belonging to this tunnel queued to neighbors.
3119 * Free any allocated resources linked to the tunnel.
3121 * @param t The tunnel to destroy.
3124 GCT_destroy (struct CadetTunnel *t)
3126 struct CadetTConnection *iter_c;
3127 struct CadetTConnection *next_c;
3128 struct CadetTChannel *iter_ch;
3129 struct CadetTChannel *next_ch;
3134 LOG (GNUNET_ERROR_TYPE_DEBUG, "destroying tunnel %s\n", GCP_2s (t->peer));
3136 GNUNET_break (GNUNET_YES ==
3137 GNUNET_CONTAINER_multipeermap_remove (tunnels,
3138 GCP_get_id (t->peer), t));
3140 for (iter_c = t->connection_head; NULL != iter_c; iter_c = next_c)
3142 next_c = iter_c->next;
3143 GCC_destroy (iter_c->c);
3145 for (iter_ch = t->channel_head; NULL != iter_ch; iter_ch = next_ch)
3147 next_ch = iter_ch->next;
3148 GCCH_destroy (iter_ch->ch);
3149 /* Should only happen on shutdown, but it's ok. */
3152 if (NULL != t->destroy_task)
3154 LOG (GNUNET_ERROR_TYPE_DEBUG, "cancelling dest: %llX\n", t->destroy_task);
3155 GNUNET_SCHEDULER_cancel (t->destroy_task);
3156 t->destroy_task = NULL;
3159 if (NULL != t->trim_connections_task)
3161 LOG (GNUNET_ERROR_TYPE_DEBUG, "cancelling trim: %llX\n",
3162 t->trim_connections_task);
3163 GNUNET_SCHEDULER_cancel (t->trim_connections_task);
3164 t->trim_connections_task = NULL;
3167 GNUNET_STATISTICS_update (stats, "# tunnels", -1, GNUNET_NO);
3168 GCP_set_tunnel (t->peer, NULL);
3170 if (NULL != t->rekey_task)
3172 GNUNET_SCHEDULER_cancel (t->rekey_task);
3173 t->rekey_task = NULL;
3175 if (NULL != t->kx_ctx)
3177 if (NULL != t->kx_ctx->finish_task)
3178 GNUNET_SCHEDULER_cancel (t->kx_ctx->finish_task);
3179 GNUNET_free (t->kx_ctx);
3190 * @brief Use the given path for the tunnel.
3191 * Update the next and prev hops (and RCs).
3192 * (Re)start the path refresh in case the tunnel is locally owned.
3194 * @param t Tunnel to update.
3195 * @param p Path to use.
3197 * @return Connection created.
3199 struct CadetConnection *
3200 GCT_use_path (struct CadetTunnel *t, struct CadetPeerPath *p)
3202 struct CadetConnection *c;
3203 struct GNUNET_CADET_Hash cid;
3204 unsigned int own_pos;
3206 if (NULL == t || NULL == p)
3212 if (CADET_TUNNEL_SHUTDOWN == t->cstate)
3218 for (own_pos = 0; own_pos < p->length; own_pos++)
3220 if (p->peers[own_pos] == myid)
3223 if (own_pos >= p->length)
3225 GNUNET_break_op (0);
3229 GNUNET_CRYPTO_random_block (GNUNET_CRYPTO_QUALITY_NONCE, &cid, sizeof (cid));
3230 c = GCC_new (&cid, t, p, own_pos);
3233 /* Path was flawed */
3236 GCT_add_connection (t, c);
3242 * Count all created connections of a tunnel. Not necessarily ready connections!
3244 * @param t Tunnel on which to count.
3246 * @return Number of connections created, either being established or ready.
3249 GCT_count_any_connections (struct CadetTunnel *t)
3251 struct CadetTConnection *iter;
3257 for (count = 0, iter = t->connection_head; NULL != iter; iter = iter->next)
3265 * Count established (ready) connections of a tunnel.
3267 * @param t Tunnel on which to count.
3269 * @return Number of connections.
3272 GCT_count_connections (struct CadetTunnel *t)
3274 struct CadetTConnection *iter;
3280 for (count = 0, iter = t->connection_head; NULL != iter; iter = iter->next)
3281 if (CADET_CONNECTION_READY == GCC_get_state (iter->c))
3289 * Count channels of a tunnel.
3291 * @param t Tunnel on which to count.
3293 * @return Number of channels.
3296 GCT_count_channels (struct CadetTunnel *t)
3298 struct CadetTChannel *iter;
3301 for (count = 0, iter = t->channel_head;
3303 iter = iter->next, count++) /* skip */;
3310 * Get the connectivity state of a tunnel.
3314 * @return Tunnel's connectivity state.
3316 enum CadetTunnelCState
3317 GCT_get_cstate (struct CadetTunnel *t)
3322 return (enum CadetTunnelCState) -1;
3329 * Get the encryption state of a tunnel.
3333 * @return Tunnel's encryption state.
3335 enum CadetTunnelEState
3336 GCT_get_estate (struct CadetTunnel *t)
3341 return (enum CadetTunnelEState) -1;
3347 * Get the maximum buffer space for a tunnel towards a local client.
3351 * @return Biggest buffer space offered by any channel in the tunnel.
3354 GCT_get_channels_buffer (struct CadetTunnel *t)
3356 struct CadetTChannel *iter;
3357 unsigned int buffer;
3358 unsigned int ch_buf;
3360 if (NULL == t->channel_head)
3362 /* Probably getting buffer for a channel create/handshake. */
3363 LOG (GNUNET_ERROR_TYPE_DEBUG, " no channels, allow max\n");
3368 for (iter = t->channel_head; NULL != iter; iter = iter->next)
3370 ch_buf = get_channel_buffer (iter);
3371 if (ch_buf > buffer)
3379 * Get the total buffer space for a tunnel for P2P traffic.
3383 * @return Buffer space offered by all connections in the tunnel.
3386 GCT_get_connections_buffer (struct CadetTunnel *t)
3388 struct CadetTConnection *iter;
3389 unsigned int buffer;
3391 if (GNUNET_NO == is_ready (t))
3393 if (count_queued_data (t) > 3)
3400 for (iter = t->connection_head; NULL != iter; iter = iter->next)
3402 if (GCC_get_state (iter->c) != CADET_CONNECTION_READY)
3406 buffer += get_connection_buffer (iter);
3414 * Get the tunnel's destination.
3418 * @return ID of the destination peer.
3420 const struct GNUNET_PeerIdentity *
3421 GCT_get_destination (struct CadetTunnel *t)
3423 return GCP_get_id (t->peer);
3428 * Get the tunnel's next free global channel ID.
3432 * @return GID of a channel free to use.
3435 GCT_get_next_chid (struct CadetTunnel *t)
3437 CADET_ChannelNumber chid;
3438 CADET_ChannelNumber mask;
3441 /* Set bit 30 depending on the ID relationship. Bit 31 is always 0 for GID.
3442 * If our ID is bigger or loopback tunnel, start at 0, bit 30 = 0
3443 * If peer's ID is bigger, start at 0x4... bit 30 = 1
3445 result = GNUNET_CRYPTO_cmp_peer_identity (&my_full_id, GCP_get_id (t->peer));
3450 t->next_chid |= mask;
3452 while (NULL != GCT_get_channel (t, t->next_chid))
3454 LOG (GNUNET_ERROR_TYPE_DEBUG, "Channel %u exists...\n", t->next_chid);
3455 t->next_chid = (t->next_chid + 1) & ~GNUNET_CADET_LOCAL_CHANNEL_ID_CLI;
3456 t->next_chid |= mask;
3458 chid = t->next_chid;
3459 t->next_chid = (t->next_chid + 1) & ~GNUNET_CADET_LOCAL_CHANNEL_ID_CLI;
3460 t->next_chid |= mask;
3467 * Send ACK on one or more channels due to buffer in connections.
3469 * @param t Channel which has some free buffer space.
3472 GCT_unchoke_channels (struct CadetTunnel *t)
3474 struct CadetTChannel *iter;
3475 unsigned int buffer;
3476 unsigned int channels = GCT_count_channels (t);
3477 unsigned int choked_n;
3478 struct CadetChannel *choked[channels];
3480 LOG (GNUNET_ERROR_TYPE_DEBUG, "GCT_unchoke_channels on %s\n", GCT_2s (t));
3481 LOG (GNUNET_ERROR_TYPE_DEBUG, " head: %p\n", t->channel_head);
3482 if (NULL != t->channel_head)
3483 LOG (GNUNET_ERROR_TYPE_DEBUG, " head ch: %p\n", t->channel_head->ch);
3485 /* Get buffer space */
3486 buffer = GCT_get_connections_buffer (t);
3492 /* Count and remember choked channels */
3494 for (iter = t->channel_head; NULL != iter; iter = iter->next)
3496 if (GNUNET_NO == get_channel_allowed (iter))
3498 choked[choked_n++] = iter->ch;
3502 /* Unchoke random channels */
3503 while (0 < buffer && 0 < choked_n)
3505 unsigned int r = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK,
3507 GCCH_allow_client (choked[r], GCCH_is_origin (choked[r], GNUNET_YES));
3510 choked[r] = choked[choked_n];
3516 * Send ACK on one or more connections due to buffer space to the client.
3518 * Iterates all connections of the tunnel and sends ACKs appropriately.
3523 GCT_send_connection_acks (struct CadetTunnel *t)
3525 struct CadetTConnection *iter;
3528 uint32_t allow_per_connection;
3530 unsigned int buffer;
3532 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel send connection ACKs on %s\n",
3541 if (CADET_TUNNEL_READY != t->cstate)
3544 buffer = GCT_get_channels_buffer (t);
3545 LOG (GNUNET_ERROR_TYPE_DEBUG, " buffer %u\n", buffer);
3547 /* Count connections, how many messages are already allowed */
3548 cs = GCT_count_connections (t);
3549 for (allowed = 0, iter = t->connection_head; NULL != iter; iter = iter->next)
3551 allowed += get_connection_allowed (iter);
3553 LOG (GNUNET_ERROR_TYPE_DEBUG, " allowed %u\n", allowed);
3555 /* Make sure there is no overflow */
3556 if (allowed > buffer)
3559 /* Authorize connections to send more data */
3560 to_allow = buffer - allowed;
3562 for (iter = t->connection_head;
3563 NULL != iter && to_allow > 0;
3566 if (CADET_CONNECTION_READY != GCC_get_state (iter->c)
3567 || get_connection_allowed (iter) > 64 / 3)
3571 allow_per_connection = to_allow/cs;
3572 to_allow -= allow_per_connection;
3574 GCC_allow (iter->c, allow_per_connection,
3575 GCC_is_origin (iter->c, GNUNET_NO));
3580 /* Since we don't allow if it's allowed to send 64/3, this can happen. */
3581 LOG (GNUNET_ERROR_TYPE_DEBUG, " reminding to_allow: %u\n", to_allow);
3587 * Cancel a previously sent message while it's in the queue.
3589 * ONLY can be called before the continuation given to the send function
3590 * is called. Once the continuation is called, the message is no longer in the
3593 * @param q Handle to the queue.
3596 GCT_cancel (struct CadetTunnelQueue *q)
3601 /* tun_message_sent() will be called and free q */
3603 else if (NULL != q->tqd)
3605 unqueue_data (q->tqd);
3607 if (NULL != q->cont)
3608 q->cont (q->cont_cls, NULL, q, 0, 0);
3619 * Sends an already built message on a tunnel, encrypting it and
3620 * choosing the best connection if not provided.
3622 * @param message Message to send. Function modifies it.
3623 * @param t Tunnel on which this message is transmitted.
3624 * @param c Connection to use (autoselect if NULL).
3625 * @param force Force the tunnel to take the message (buffer overfill).
3626 * @param cont Continuation to call once message is really sent.
3627 * @param cont_cls Closure for @c cont.
3629 * @return Handle to cancel message. NULL if @c cont is NULL.
3631 struct CadetTunnelQueue *
3632 GCT_send_prebuilt_message (const struct GNUNET_MessageHeader *message,
3633 struct CadetTunnel *t, struct CadetConnection *c,
3634 int force, GCT_sent cont, void *cont_cls)
3636 return send_prebuilt_message (message, t, c, force, cont, cont_cls, NULL);
3640 * Sends an already built and encrypted message on a tunnel, choosing the best
3641 * connection. Useful for re-queueing messages queued on a destroyed connection.
3643 * @param message Message to send. Function modifies it.
3644 * @param t Tunnel on which this message is transmitted.
3647 GCT_resend_message (const struct GNUNET_MessageHeader *message,
3648 struct CadetTunnel *t)
3650 struct CadetConnection *c;
3653 c = tunnel_get_connection (t);
3656 /* TODO queue in tunnel, marked as encrypted */
3657 LOG (GNUNET_ERROR_TYPE_DEBUG, "No connection available, dropping.\n");
3660 fwd = GCC_is_origin (c, GNUNET_YES);
3661 GNUNET_break (NULL == GCC_send_prebuilt_message (message, 0, 0, c, fwd,
3662 GNUNET_YES, NULL, NULL));
3667 * Is the tunnel directed towards the local peer?
3671 * @return #GNUNET_YES if it is loopback.
3674 GCT_is_loopback (const struct CadetTunnel *t)
3676 return (myid == GCP_get_short_id (t->peer));
3681 * Is the tunnel this path already?
3686 * @return #GNUNET_YES a connection uses this path.
3689 GCT_is_path_used (const struct CadetTunnel *t, const struct CadetPeerPath *p)
3691 struct CadetTConnection *iter;
3693 for (iter = t->connection_head; NULL != iter; iter = iter->next)
3694 if (path_equivalent (GCC_get_path (iter->c), p))
3702 * Get a cost of a path for a tunnel considering existing connections.
3705 * @param path Candidate path.
3707 * @return Cost of the path (path length + number of overlapping nodes)
3710 GCT_get_path_cost (const struct CadetTunnel *t,
3711 const struct CadetPeerPath *path)
3713 struct CadetTConnection *iter;
3714 const struct CadetPeerPath *aux;
3715 unsigned int overlap;
3723 GNUNET_assert (NULL != t);
3725 for (i = 0; i < path->length; i++)
3727 for (iter = t->connection_head; NULL != iter; iter = iter->next)
3729 aux = GCC_get_path (iter->c);
3733 for (j = 0; j < aux->length; j++)
3735 if (path->peers[i] == aux->peers[j])
3743 return path->length + overlap;
3748 * Get the static string for the peer this tunnel is directed.
3752 * @return Static string the destination peer's ID.
3755 GCT_2s (const struct CadetTunnel *t)
3760 return GCP_2s (t->peer);
3764 /******************************************************************************/
3765 /***************************** INFO/DEBUG *******************************/
3766 /******************************************************************************/
3769 * Log all possible info about the tunnel state.
3771 * @param t Tunnel to debug.
3772 * @param level Debug level to use.
3775 GCT_debug (const struct CadetTunnel *t, enum GNUNET_ErrorType level)
3777 struct CadetTChannel *iterch;
3778 struct CadetTConnection *iterc;
3781 do_log = GNUNET_get_log_call_status (level & (~GNUNET_ERROR_TYPE_BULK),
3783 __FILE__, __FUNCTION__, __LINE__);
3787 LOG2 (level, "TTT DEBUG TUNNEL TOWARDS %s\n", GCT_2s (t));
3788 LOG2 (level, "TTT cstate %s, estate %s\n",
3789 cstate2s (t->cstate), estate2s (t->estate));
3790 LOG2 (level, "TTT kx_ctx %p, rekey_task %u, finish task %u\n",
3791 t->kx_ctx, t->rekey_task, t->kx_ctx ? t->kx_ctx->finish_task : 0);
3792 #if DUMP_KEYS_TO_STDERR
3793 LOG2 (level, "TTT my EPHM\t %s\n",
3794 GNUNET_h2s ((struct GNUNET_HashCode *) &kx_msg.ephemeral_key));
3795 LOG2 (level, "TTT peers EPHM:\t %s\n",
3796 GNUNET_h2s ((struct GNUNET_HashCode *) &t->peers_ephemeral_key));
3797 LOG2 (level, "TTT ENC key:\t %s\n",
3798 GNUNET_h2s ((struct GNUNET_HashCode *) &t->e_key));
3799 LOG2 (level, "TTT DEC key:\t %s\n",
3800 GNUNET_h2s ((struct GNUNET_HashCode *) &t->d_key));
3803 LOG2 (level, "TTT OLD ENC key:\t %s\n",
3804 GNUNET_h2s ((struct GNUNET_HashCode *) &t->kx_ctx->e_key_old));
3805 LOG2 (level, "TTT OLD DEC key:\t %s\n",
3806 GNUNET_h2s ((struct GNUNET_HashCode *) &t->kx_ctx->d_key_old));
3809 LOG2 (level, "TTT tq_head %p, tq_tail %p\n", t->tq_head, t->tq_tail);
3810 LOG2 (level, "TTT destroy %u\n", t->destroy_task);
3812 LOG2 (level, "TTT channels:\n");
3813 for (iterch = t->channel_head; NULL != iterch; iterch = iterch->next)
3815 LOG2 (level, "TTT - %s\n", GCCH_2s (iterch->ch));
3818 LOG2 (level, "TTT connections:\n");
3819 for (iterc = t->connection_head; NULL != iterc; iterc = iterc->next)
3821 GCC_debug (iterc->c, level);
3824 LOG2 (level, "TTT DEBUG TUNNEL END\n");
3829 * Iterate all tunnels.
3831 * @param iter Iterator.
3832 * @param cls Closure for @c iter.
3835 GCT_iterate_all (GNUNET_CONTAINER_PeerMapIterator iter, void *cls)
3837 GNUNET_CONTAINER_multipeermap_iterate (tunnels, iter, cls);
3842 * Count all tunnels.
3844 * @return Number of tunnels to remote peers kept by this peer.
3847 GCT_count_all (void)
3849 return GNUNET_CONTAINER_multipeermap_size (tunnels);
3854 * Iterate all connections of a tunnel.
3856 * @param t Tunnel whose connections to iterate.
3857 * @param iter Iterator.
3858 * @param cls Closure for @c iter.
3861 GCT_iterate_connections (struct CadetTunnel *t, GCT_conn_iter iter, void *cls)
3863 struct CadetTConnection *ct;
3865 for (ct = t->connection_head; NULL != ct; ct = ct->next)
3871 * Iterate all channels of a tunnel.
3873 * @param t Tunnel whose channels to iterate.
3874 * @param iter Iterator.
3875 * @param cls Closure for @c iter.
3878 GCT_iterate_channels (struct CadetTunnel *t, GCT_chan_iter iter, void *cls)
3880 struct CadetTChannel *cht;
3882 for (cht = t->channel_head; NULL != cht; cht = cht->next)
3883 iter (cls, cht->ch);