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.
155 * Struct to old keys for skipped messages while advancing the Axolotl ratchet.
157 struct CadetTunnelSkippedKey
162 struct CadetTunnelSkippedKey *next;
167 struct CadetTunnelSkippedKey *prev;
170 * When was this key stored (for timeout).
172 struct GNUNET_TIME_Absolute timestamp;
177 struct GNUNET_CRYPTO_SymmetricSessionKey HK;
182 struct GNUNET_CRYPTO_SymmetricSessionKey MK;
186 * Axolotl data, according to https://github.com/trevp/axolotl/wiki
188 struct CadetTunnelAxolotl
191 * A (double linked) list of stored message keys and associated header keys
192 * for "skipped" messages, i.e. messages that have not bee*n
193 * received despite the reception of more recent messages, (head)/
195 struct CadetTunnelSkippedKey *skipped_head;
198 * Skipped messages' keys DLL, tail.
200 struct CadetTunnelSkippedKey *skipped_tail;
203 * Elements in @a skipped_head <-> @a skipped_tail.
208 * 32-byte root key which gets updated by DH ratchet
210 struct GNUNET_CRYPTO_SymmetricSessionKey RK;
213 * 32-byte header key (send)
215 struct GNUNET_CRYPTO_SymmetricSessionKey HKs;
218 * 32-byte header key (recv)
220 struct GNUNET_CRYPTO_SymmetricSessionKey HKr;
223 * 32-byte next header key (send)
225 struct GNUNET_CRYPTO_SymmetricSessionKey NHKs;
228 * 32-byte next header key (recv)
230 struct GNUNET_CRYPTO_SymmetricSessionKey NHKr;
233 * 32-byte chain keys (used for forward-secrecy updating, send)
235 struct GNUNET_CRYPTO_SymmetricSessionKey CKs;
238 * 32-byte chain keys (used for forward-secrecy updating, recv)
240 struct GNUNET_CRYPTO_SymmetricSessionKey CKr;
243 * ECDH for key exchange (A0 / B0)
245 struct GNUNET_CRYPTO_EcdhePrivateKey *kx_0;
248 * ECDH Ratchet key (send)
250 struct GNUNET_CRYPTO_EcdhePrivateKey *DHRs;
253 * ECDH Ratchet key (recv)
255 struct GNUNET_CRYPTO_EcdhePublicKey DHRr;
258 * Message number (reset to 0 with each new ratchet, send)
263 * Message numbers (reset to 0 with each new ratchet, recv)
268 * Previous message numbers (# of msgs sent under prev ratchet)
273 * True (#GNUNET_YES) if the party will send a new ratchet key in next msg.
279 * Struct containing all information regarding a tunnel to a peer.
284 * Endpoint of the tunnel.
286 struct CadetPeer *peer;
289 * Type of encryption used in the tunnel.
291 enum CadetTunnelEncryption enc_type;
296 struct CadetTunnelAxolotl *ax;
299 * State of the tunnel connectivity.
301 enum CadetTunnelCState cstate;
304 * State of the tunnel encryption.
306 enum CadetTunnelEState estate;
309 * Key eXchange context.
311 struct CadetTunnelKXCtx *kx_ctx;
314 * Peer's ephemeral key, to recreate @c e_key and @c d_key when own ephemeral
317 struct GNUNET_CRYPTO_EcdhePublicKey peers_ephemeral_key;
320 * Encryption ("our") key. It is only "confirmed" if kx_ctx is NULL.
322 struct GNUNET_CRYPTO_SymmetricSessionKey e_key;
325 * Decryption ("their") key. It is only "confirmed" if kx_ctx is NULL.
327 struct GNUNET_CRYPTO_SymmetricSessionKey d_key;
330 * Task to start the rekey process.
332 struct GNUNET_SCHEDULER_Task * rekey_task;
335 * Paths that are actively used to reach the destination peer.
337 struct CadetTConnection *connection_head;
338 struct CadetTConnection *connection_tail;
341 * Next connection number.
346 * Channels inside this tunnel.
348 struct CadetTChannel *channel_head;
349 struct CadetTChannel *channel_tail;
352 * Channel ID for the next created channel.
354 CADET_ChannelNumber next_chid;
357 * Destroy flag: if true, destroy on last message.
359 struct GNUNET_SCHEDULER_Task * destroy_task;
362 * Queued messages, to transmit once tunnel gets connected.
364 struct CadetTunnelDelayed *tq_head;
365 struct CadetTunnelDelayed *tq_tail;
368 * Task to trim connections if too many are present.
370 struct GNUNET_SCHEDULER_Task * trim_connections_task;
373 * Ephemeral message in the queue (to avoid queueing more than one).
375 struct CadetConnectionQueue *ephm_h;
378 * Pong message in the queue.
380 struct CadetConnectionQueue *pong_h;
385 * Struct used to save messages in a non-ready tunnel to send once connected.
387 struct CadetTunnelDelayed
392 struct CadetTunnelDelayed *next;
393 struct CadetTunnelDelayed *prev;
398 struct CadetTunnel *t;
401 * Tunnel queue given to the channel to cancel request. Update on send_queued.
403 struct CadetTunnelQueue *tq;
408 /* struct GNUNET_MessageHeader *msg; */
413 * Handle for messages queued but not yet sent.
415 struct CadetTunnelQueue
418 * Connection queue handle, to cancel if necessary.
420 struct CadetConnectionQueue *cq;
423 * Handle in case message hasn't been given to a connection yet.
425 struct CadetTunnelDelayed *tqd;
428 * Continuation to call once sent.
433 * Closure for @c cont.
440 * Cached Axolotl key with signature.
442 struct CadetAxolotlSignedKey
445 * Information about what is being signed (@a permanent_key).
447 struct GNUNET_CRYPTO_EccSignaturePurpose purpose;
450 * Permanent public ECDH key.
452 struct GNUNET_CRYPTO_EcdhePublicKey permanent_key;
455 * An EdDSA signature of the permanent ECDH key with the Peer's ID key.
457 struct GNUNET_CRYPTO_EddsaSignature signature;
461 /******************************************************************************/
462 /******************************* GLOBALS ***********************************/
463 /******************************************************************************/
466 * Global handle to the statistics service.
468 extern struct GNUNET_STATISTICS_Handle *stats;
471 * Local peer own ID (memory efficient handle).
473 extern GNUNET_PEER_Id myid;
476 * Local peer own ID (full value).
478 extern struct GNUNET_PeerIdentity my_full_id;
482 * Don't try to recover tunnels if shutting down.
484 extern int shutting_down;
488 * Set of all tunnels, in order to trigger a new exchange on rekey.
489 * Indexed by peer's ID.
491 static struct GNUNET_CONTAINER_MultiPeerMap *tunnels;
494 * Default TTL for payload packets.
496 static unsigned long long default_ttl;
500 * Own Peer ID private key.
502 const static struct GNUNET_CRYPTO_EddsaPrivateKey *id_key;
504 /******************************** AXOLOTL ************************************/
506 static struct GNUNET_CRYPTO_EcdhePrivateKey *ax_key;
509 * Own Axolotl permanent public key (cache).
511 static struct CadetAxolotlSignedKey ax_identity;
513 /******************************** OTR ***********************************/
517 * Own global OTR ephemeral private key.
519 static struct GNUNET_CRYPTO_EcdhePrivateKey *otr_ephemeral_key;
522 * Cached message used to perform a OTR key exchange.
524 static struct GNUNET_CADET_KX_Ephemeral otr_kx_msg;
527 * Task to generate a new OTR ephemeral key.
529 static struct GNUNET_SCHEDULER_Task *rekey_task;
534 static struct GNUNET_TIME_Relative rekey_period;
537 /******************************************************************************/
538 /******************************** STATIC ***********************************/
539 /******************************************************************************/
542 * Get string description for tunnel connectivity state.
544 * @param cs Tunnel state.
546 * @return String representation.
549 cstate2s (enum CadetTunnelCState cs)
555 case CADET_TUNNEL_NEW:
556 return "CADET_TUNNEL_NEW";
557 case CADET_TUNNEL_SEARCHING:
558 return "CADET_TUNNEL_SEARCHING";
559 case CADET_TUNNEL_WAITING:
560 return "CADET_TUNNEL_WAITING";
561 case CADET_TUNNEL_READY:
562 return "CADET_TUNNEL_READY";
563 case CADET_TUNNEL_SHUTDOWN:
564 return "CADET_TUNNEL_SHUTDOWN";
566 SPRINTF (buf, "%u (UNKNOWN STATE)", cs);
574 * Get string description for tunnel encryption state.
576 * @param es Tunnel state.
578 * @return String representation.
581 estate2s (enum CadetTunnelEState es)
587 case CADET_TUNNEL_KEY_UNINITIALIZED:
588 return "CADET_TUNNEL_KEY_UNINITIALIZED";
589 case CADET_TUNNEL_KEY_SENT:
590 return "CADET_TUNNEL_KEY_SENT";
591 case CADET_TUNNEL_KEY_PING:
592 return "CADET_TUNNEL_KEY_PING";
593 case CADET_TUNNEL_KEY_OK:
594 return "CADET_TUNNEL_KEY_OK";
595 case CADET_TUNNEL_KEY_REKEY:
596 return "CADET_TUNNEL_KEY_REKEY";
598 SPRINTF (buf, "%u (UNKNOWN STATE)", es);
606 * @brief Check if tunnel is ready to send traffic.
608 * Tunnel must be connected and with encryption correctly set up.
610 * @param t Tunnel to check.
612 * @return #GNUNET_YES if ready, #GNUNET_NO otherwise
615 is_ready (struct CadetTunnel *t)
619 GCT_debug (t, GNUNET_ERROR_TYPE_DEBUG);
620 ready = CADET_TUNNEL_READY == t->cstate
621 && (CADET_TUNNEL_KEY_OK == t->estate
622 || CADET_TUNNEL_KEY_REKEY == t->estate);
623 ready = ready || GCT_is_loopback (t);
629 * Check if a key is invalid (NULL pointer or all 0)
631 * @param key Key to check.
633 * @return #GNUNET_YES if key is null, #GNUNET_NO if exists and is not 0.
636 is_key_null (struct GNUNET_CRYPTO_SymmetricSessionKey *key)
638 struct GNUNET_CRYPTO_SymmetricSessionKey null_key;
643 memset (&null_key, 0, sizeof (null_key));
644 if (0 == memcmp (key, &null_key, sizeof (null_key)))
651 * Ephemeral key message purpose size.
653 * @return Size of the part of the ephemeral key message that must be signed.
656 ephemeral_purpose_size (void)
658 return sizeof (struct GNUNET_CRYPTO_EccSignaturePurpose) +
659 sizeof (struct GNUNET_TIME_AbsoluteNBO) +
660 sizeof (struct GNUNET_TIME_AbsoluteNBO) +
661 sizeof (struct GNUNET_CRYPTO_EcdhePublicKey) +
662 sizeof (struct GNUNET_PeerIdentity);
667 * Ephemeral key message purpose size.
669 * @return Size of the part of the ephemeral key message that must be signed.
672 ax_purpose_size (void)
674 return sizeof (struct GNUNET_CRYPTO_EccSignaturePurpose) +
675 sizeof (struct GNUNET_CRYPTO_EcdhePublicKey);
680 * Size of the encrypted part of a ping message.
682 * @return Size of the encrypted part of a ping message.
685 ping_encryption_size (void)
687 return sizeof (uint32_t);
692 * Get the channel's buffer. ONLY FOR NON-LOOPBACK CHANNELS!!
694 * @param tch Tunnel's channel handle.
696 * @return Amount of messages the channel can still buffer towards the client.
699 get_channel_buffer (const struct CadetTChannel *tch)
703 /* If channel is incoming, is terminal in the FWD direction and fwd is YES */
704 fwd = GCCH_is_terminal (tch->ch, GNUNET_YES);
706 return GCCH_get_buffer (tch->ch, fwd);
711 * Get the channel's allowance status.
713 * @param tch Tunnel's channel handle.
715 * @return #GNUNET_YES if we allowed the client to send data to us.
718 get_channel_allowed (const struct CadetTChannel *tch)
722 /* If channel is outgoing, is origin in the FWD direction and fwd is YES */
723 fwd = GCCH_is_origin (tch->ch, GNUNET_YES);
725 return GCCH_get_allowed (tch->ch, fwd);
730 * Get the connection's buffer.
732 * @param tc Tunnel's connection handle.
734 * @return Amount of messages the connection can still buffer.
737 get_connection_buffer (const struct CadetTConnection *tc)
741 /* If connection is outgoing, is origin in the FWD direction and fwd is YES */
742 fwd = GCC_is_origin (tc->c, GNUNET_YES);
744 return GCC_get_buffer (tc->c, fwd);
749 * Get the connection's allowance.
751 * @param tc Tunnel's connection handle.
753 * @return Amount of messages we have allowed the next peer to send us.
756 get_connection_allowed (const struct CadetTConnection *tc)
760 /* If connection is outgoing, is origin in the FWD direction and fwd is YES */
761 fwd = GCC_is_origin (tc->c, GNUNET_YES);
763 return GCC_get_allowed (tc->c, fwd);
768 * Check that a ephemeral key message s well formed and correctly signed.
770 * @param t Tunnel on which the message came.
771 * @param msg The ephemeral key message.
773 * @return GNUNET_OK if message is fine, GNUNET_SYSERR otherwise.
776 check_ephemeral (struct CadetTunnel *t,
777 const struct GNUNET_CADET_KX_Ephemeral *msg)
779 /* Check message size */
780 if (ntohs (msg->header.size) != sizeof (struct GNUNET_CADET_KX_Ephemeral))
781 return GNUNET_SYSERR;
783 /* Check signature size */
784 if (ntohl (msg->purpose.size) != ephemeral_purpose_size ())
785 return GNUNET_SYSERR;
788 if (0 != memcmp (&msg->origin_identity,
789 GCP_get_id (t->peer),
790 sizeof (struct GNUNET_PeerIdentity)))
791 return GNUNET_SYSERR;
793 /* Check signature */
795 GNUNET_CRYPTO_eddsa_verify (GNUNET_SIGNATURE_PURPOSE_CADET_KX,
798 &msg->origin_identity.public_key))
799 return GNUNET_SYSERR;
806 * Select the best key to use for encryption (send), based on KX status.
808 * Normally, return the current key. If there is a KX in progress and the old
809 * key is fresh enough, return the old key.
811 * @param t Tunnel to choose the key from.
813 * @return The optimal key to encrypt/hmac outgoing traffic.
815 static const struct GNUNET_CRYPTO_SymmetricSessionKey *
816 select_key (const struct CadetTunnel *t)
818 const struct GNUNET_CRYPTO_SymmetricSessionKey *key;
820 if (NULL != t->kx_ctx
821 && NULL == t->kx_ctx->finish_task)
823 struct GNUNET_TIME_Relative age;
825 age = GNUNET_TIME_absolute_get_duration (t->kx_ctx->rekey_start_time);
826 LOG (GNUNET_ERROR_TYPE_DEBUG,
827 " key exchange in progress, started %s ago\n",
828 GNUNET_STRINGS_relative_time_to_string (age, GNUNET_YES));
829 // FIXME make duration of old keys configurable
830 if (age.rel_value_us < GNUNET_TIME_UNIT_MINUTES.rel_value_us)
832 LOG (GNUNET_ERROR_TYPE_DEBUG, " using old key\n");
833 key = &t->kx_ctx->e_key_old;
837 LOG (GNUNET_ERROR_TYPE_DEBUG, " using new key (old key too old)\n");
843 LOG (GNUNET_ERROR_TYPE_DEBUG, " no KX: using current key\n");
853 * @param plaintext Content to HMAC.
854 * @param size Size of @c plaintext.
855 * @param iv Initialization vector for the message.
856 * @param key Key to use.
857 * @param hmac[out] Destination to store the HMAC.
860 t_hmac (const void *plaintext, size_t size,
861 uint32_t iv, const struct GNUNET_CRYPTO_SymmetricSessionKey *key,
862 struct GNUNET_CADET_Hash *hmac)
864 static const char ctx[] = "cadet authentication key";
865 struct GNUNET_CRYPTO_AuthKey auth_key;
866 struct GNUNET_HashCode hash;
868 #if DUMP_KEYS_TO_STDERR
869 LOG (GNUNET_ERROR_TYPE_INFO, " HMAC with key %s\n",
870 GNUNET_h2s ((struct GNUNET_HashCode *) key));
872 GNUNET_CRYPTO_hmac_derive_key (&auth_key, key,
877 /* Two step: CADET_Hash is only 256 bits, HashCode is 512. */
878 GNUNET_CRYPTO_hmac (&auth_key, plaintext, size, &hash);
879 memcpy (hmac, &hash, sizeof (*hmac));
884 * Encrypt daforce_newest_keyta with the tunnel key.
886 * @param t Tunnel whose key to use.
887 * @param dst Destination for the encrypted data.
888 * @param src Source of the plaintext. Can overlap with @c dst.
889 * @param size Size of the plaintext.
890 * @param iv Initialization Vector to use.
891 * @param force_newest_key Force the use of the newest key, otherwise
892 * CADET will use the old key when allowed.
893 * This can happen in the case when a KX is going on
894 * and the old one hasn't expired.
897 t_encrypt (struct CadetTunnel *t, void *dst, const void *src,
898 size_t size, uint32_t iv, int force_newest_key)
900 struct GNUNET_CRYPTO_SymmetricInitializationVector siv;
901 const struct GNUNET_CRYPTO_SymmetricSessionKey *key;
904 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_encrypt start\n");
906 key = GNUNET_YES == force_newest_key ? &t->e_key : select_key (t);
907 #if DUMP_KEYS_TO_STDERR
908 LOG (GNUNET_ERROR_TYPE_INFO, " ENC with key %s\n",
909 GNUNET_h2s ((struct GNUNET_HashCode *) key));
911 GNUNET_CRYPTO_symmetric_derive_iv (&siv, key, &iv, sizeof (iv), NULL);
912 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_encrypt IV derived\n");
913 out_size = GNUNET_CRYPTO_symmetric_encrypt (src, size, key, &siv, dst);
914 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_encrypt end\n");
923 * @param key Key to use.
924 * @param hash[out] Resulting HMAC.
925 * @param source Source key material (data to HMAC).
926 * @param len Length of @a source.
929 t_ax_hmac_hash (struct GNUNET_CRYPTO_SymmetricSessionKey *key,
930 struct GNUNET_HashCode *hash,
931 void *source, unsigned int len)
933 static const char ctx[] = "axolotl HMAC-HASH";
934 struct GNUNET_CRYPTO_AuthKey auth_key;
936 GNUNET_CRYPTO_hmac_derive_key (&auth_key, key,
939 GNUNET_CRYPTO_hmac (&auth_key, source, len, hash);
944 * Derive a key from a HMAC-HASH.
946 * @param key Key to use for the HMAC.
947 * @param out Key to generate.
948 * @param source Source key material (data to HMAC).
949 * @param len Length of @a source.
952 t_hmac_derive_key (struct GNUNET_CRYPTO_SymmetricSessionKey *key,
953 struct GNUNET_CRYPTO_SymmetricSessionKey *out,
954 void *source, unsigned int len)
956 static const char ctx[] = "axolotl derive key";
957 struct GNUNET_HashCode h;
959 t_ax_hmac_hash (key, &h, source, len);
960 GNUNET_CRYPTO_kdf (out, sizeof (*out), ctx, sizeof (ctx),
961 &h, sizeof (h), NULL);
966 * Encrypt data with the tunnel key.
968 * @param t Tunnel whose key to use.
969 * @param dst Destination for the encrypted data.
970 * @param src Source of the plaintext. Can overlap with @c dst.
971 * @param size Size of the plaintext.
973 * @return Size of the encrypted data.
976 t_ax_encrypt (struct CadetTunnel *t, void *dst, const void *src, size_t size)
978 struct GNUNET_CRYPTO_SymmetricSessionKey MK;
979 struct GNUNET_CRYPTO_SymmetricInitializationVector iv;
980 struct CadetTunnelAxolotl *ax;
983 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_ax_encrypt start\n");
987 if (GNUNET_YES == ax->ratchet_flag)
989 /* Advance ratchet */
992 t_hmac_derive_key (&ax->CKs, &MK, "0", 1);
993 GNUNET_CRYPTO_symmetric_derive_iv (&iv, &MK, NULL, 0, NULL);
995 #if DUMP_KEYS_TO_STDERR
996 LOG (GNUNET_ERROR_TYPE_INFO, " ENC with key %s\n",
997 GNUNET_h2s ((struct GNUNET_HashCode *) &MK));
1000 out_size = GNUNET_CRYPTO_symmetric_encrypt (src, size, &MK, &iv, dst);
1002 t_hmac_derive_key (&ax->CKs, &ax->CKs, "1", 1);
1004 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_ax_encrypt end\n");
1011 * Decrypt and verify data with the appropriate tunnel key.
1013 * @param key Key to use.
1014 * @param dst Destination for the plaintext.
1015 * @param src Source of the encrypted data. Can overlap with @c dst.
1016 * @param size Size of the encrypted data.
1017 * @param iv Initialization Vector to use.
1019 * @return Size of the decrypted data, -1 if an error was encountered.
1022 decrypt (const struct GNUNET_CRYPTO_SymmetricSessionKey *key,
1023 void *dst, const void *src, size_t size, uint32_t iv)
1025 struct GNUNET_CRYPTO_SymmetricInitializationVector siv;
1028 LOG (GNUNET_ERROR_TYPE_DEBUG, " decrypt start\n");
1029 LOG (GNUNET_ERROR_TYPE_DEBUG, " decrypt iv\n");
1030 GNUNET_CRYPTO_symmetric_derive_iv (&siv, key, &iv, sizeof (iv), NULL);
1031 LOG (GNUNET_ERROR_TYPE_DEBUG, " decrypt iv done\n");
1032 out_size = GNUNET_CRYPTO_symmetric_decrypt (src, size, key, &siv, dst);
1033 LOG (GNUNET_ERROR_TYPE_DEBUG, " decrypt end\n");
1040 * Decrypt and verify data with the most recent tunnel key.
1042 * @param t Tunnel whose key to use.
1043 * @param dst Destination for the plaintext.
1044 * @param src Source of the encrypted data. Can overlap with @c dst.
1045 * @param size Size of the encrypted data.
1046 * @param iv Initialization Vector to use.
1048 * @return Size of the decrypted data, -1 if an error was encountered.
1051 t_decrypt (struct CadetTunnel *t, void *dst, const void *src,
1052 size_t size, uint32_t iv)
1056 #if DUMP_KEYS_TO_STDERR
1057 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_decrypt with %s\n",
1058 GNUNET_h2s ((struct GNUNET_HashCode *) &t->d_key));
1060 if (CADET_TUNNEL_KEY_UNINITIALIZED == t->estate)
1062 GNUNET_STATISTICS_update (stats, "# non decryptable data", 1, GNUNET_NO);
1063 LOG (GNUNET_ERROR_TYPE_WARNING,
1064 "got data on %s without a valid key\n",
1066 GCT_debug (t, GNUNET_ERROR_TYPE_WARNING);
1070 out_size = decrypt (&t->d_key, dst, src, size, iv);
1077 * Decrypt and verify data with the appropriate tunnel key and verify that the
1078 * data has not been altered since it was sent by the remote peer.
1080 * @param t Tunnel whose key to use.
1081 * @param dst Destination for the plaintext.
1082 * @param src Source of the encrypted data. Can overlap with @c dst.
1083 * @param size Size of the encrypted data.
1084 * @param iv Initialization Vector to use.
1085 * @param msg_hmac HMAC of the message, cannot be NULL.
1087 * @return Size of the decrypted data, -1 if an error was encountered.
1090 t_decrypt_and_validate (struct CadetTunnel *t,
1091 void *dst, const void *src,
1092 size_t size, uint32_t iv,
1093 const struct GNUNET_CADET_Hash *msg_hmac)
1095 struct GNUNET_CRYPTO_SymmetricSessionKey *key;
1096 struct GNUNET_CADET_Hash hmac;
1099 /* Try primary (newest) key */
1101 decrypted_size = decrypt (key, dst, src, size, iv);
1102 t_hmac (src, size, iv, key, &hmac);
1103 if (0 == memcmp (msg_hmac, &hmac, sizeof (hmac)))
1104 return decrypted_size;
1106 /* If no key exchange is going on, we just failed. */
1107 if (NULL == t->kx_ctx)
1109 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
1110 "Failed checksum validation on tunnel %s with no KX\n",
1112 GNUNET_STATISTICS_update (stats, "# wrong HMAC no KX", 1, GNUNET_NO);
1116 /* Try secondary key, from previous KX period. */
1117 key = &t->kx_ctx->d_key_old;
1118 decrypted_size = decrypt (key, dst, src, size, iv);
1119 t_hmac (src, size, iv, key, &hmac);
1120 if (0 == memcmp (msg_hmac, &hmac, sizeof (hmac)))
1121 return decrypted_size;
1123 /* Hail Mary, try tertiary, key, in case of parallel re-keys. */
1124 key = &t->kx_ctx->d_key_old2;
1125 decrypted_size = decrypt (key, dst, src, size, iv);
1126 t_hmac (src, size, iv, key, &hmac);
1127 if (0 == memcmp (msg_hmac, &hmac, sizeof (hmac)))
1128 return decrypted_size;
1130 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
1131 "Failed checksum validation on tunnel %s with KX\n",
1133 GNUNET_STATISTICS_update (stats, "# wrong HMAC with KX", 1, GNUNET_NO);
1138 * Decrypt and verify data with the appropriate tunnel key and verify that the
1139 * data has not been altered since it was sent by the remote peer.
1141 * @param t Tunnel whose key to use.
1142 * @param dst Destination for the plaintext.
1143 * @param src Source of the encrypted data. Can overlap with @c dst.
1144 * @param size Size of the encrypted data.
1145 * @param msg_hmac HMAC of the message, cannot be NULL.
1147 * @return Size of the decrypted data, -1 if an error was encountered.
1150 t_ax_decrypt_and_validate (struct CadetTunnel *t,
1151 void *dst, const void *src, size_t size,
1152 const struct GNUNET_CADET_Hash *msg_hmac)
1154 struct CadetTunnelAxolotl *ax;
1169 * Create key material by doing ECDH on the local and remote ephemeral keys.
1171 * @param key_material Where to store the key material.
1172 * @param ephemeral_key Peer's public ephemeral key.
1175 derive_key_material (struct GNUNET_HashCode *key_material,
1176 const struct GNUNET_CRYPTO_EcdhePublicKey *ephemeral_key)
1179 GNUNET_CRYPTO_ecc_ecdh (otr_ephemeral_key,
1189 * Create a symmetic key from the identities of both ends and the key material
1192 * @param key Destination for the generated key.
1193 * @param sender ID of the peer that will encrypt with @c key.
1194 * @param receiver ID of the peer that will decrypt with @c key.
1195 * @param key_material Hash created with ECDH with the ephemeral keys.
1198 derive_symmertic (struct GNUNET_CRYPTO_SymmetricSessionKey *key,
1199 const struct GNUNET_PeerIdentity *sender,
1200 const struct GNUNET_PeerIdentity *receiver,
1201 const struct GNUNET_HashCode *key_material)
1203 const char salt[] = "CADET kx salt";
1205 GNUNET_CRYPTO_kdf (key, sizeof (struct GNUNET_CRYPTO_SymmetricSessionKey),
1206 salt, sizeof (salt),
1207 key_material, sizeof (struct GNUNET_HashCode),
1208 sender, sizeof (struct GNUNET_PeerIdentity),
1209 receiver, sizeof (struct GNUNET_PeerIdentity),
1215 * Derive the tunnel's keys using our own and the peer's ephemeral keys.
1217 * @param t Tunnel for which to create the keys.
1220 create_keys (struct CadetTunnel *t)
1222 struct GNUNET_HashCode km;
1224 derive_key_material (&km, &t->peers_ephemeral_key);
1225 derive_symmertic (&t->e_key, &my_full_id, GCP_get_id (t->peer), &km);
1226 derive_symmertic (&t->d_key, GCP_get_id (t->peer), &my_full_id, &km);
1227 #if DUMP_KEYS_TO_STDERR
1228 LOG (GNUNET_ERROR_TYPE_INFO, "ME: %s\n",
1229 GNUNET_h2s ((struct GNUNET_HashCode *) &otr_kx_msg.ephemeral_key));
1230 LOG (GNUNET_ERROR_TYPE_INFO, "PE: %s\n",
1231 GNUNET_h2s ((struct GNUNET_HashCode *) &t->peers_ephemeral_key));
1232 LOG (GNUNET_ERROR_TYPE_INFO, "KM: %s\n", GNUNET_h2s (&km));
1233 LOG (GNUNET_ERROR_TYPE_INFO, "EK: %s\n",
1234 GNUNET_h2s ((struct GNUNET_HashCode *) &t->e_key));
1235 LOG (GNUNET_ERROR_TYPE_INFO, "DK: %s\n",
1236 GNUNET_h2s ((struct GNUNET_HashCode *) &t->d_key));
1242 * Create a new Key eXchange context for the tunnel.
1244 * If the old keys were verified, keep them for old traffic. Create a new KX
1245 * timestamp and a new nonce.
1247 * @param t Tunnel for which to create the KX ctx.
1250 create_kx_ctx (struct CadetTunnel *t)
1252 LOG (GNUNET_ERROR_TYPE_INFO, " new kx ctx for %s\n", GCT_2s (t));
1254 if (NULL != t->kx_ctx)
1256 if (NULL != t->kx_ctx->finish_task)
1258 LOG (GNUNET_ERROR_TYPE_INFO, " resetting exisiting finish task\n");
1259 GNUNET_SCHEDULER_cancel (t->kx_ctx->finish_task);
1260 t->kx_ctx->finish_task = NULL;
1265 t->kx_ctx = GNUNET_new (struct CadetTunnelKXCtx);
1266 t->kx_ctx->challenge = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE,
1270 if (CADET_TUNNEL_KEY_OK == t->estate)
1272 LOG (GNUNET_ERROR_TYPE_INFO, " backing up keys\n");
1273 t->kx_ctx->d_key_old = t->d_key;
1274 t->kx_ctx->e_key_old = t->e_key;
1277 LOG (GNUNET_ERROR_TYPE_INFO, " old keys not valid, not saving\n");
1278 t->kx_ctx->rekey_start_time = GNUNET_TIME_absolute_get ();
1284 * @brief Finish the Key eXchange and destroy the old keys.
1286 * @param cls Closure (Tunnel for which to finish the KX).
1287 * @param tc Task context.
1290 finish_kx (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
1292 struct CadetTunnel *t = cls;
1294 LOG (GNUNET_ERROR_TYPE_INFO, "finish KX for %s\n", GCT_2s (t));
1296 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
1298 LOG (GNUNET_ERROR_TYPE_INFO, " shutdown\n");
1302 GNUNET_free (t->kx_ctx);
1308 * Destroy a Key eXchange context for the tunnel. This function only schedules
1309 * the destruction, the freeing of the memory (and clearing of old key material)
1310 * happens after a delay!
1312 * @param t Tunnel whose KX ctx to destroy.
1315 destroy_kx_ctx (struct CadetTunnel *t)
1317 struct GNUNET_TIME_Relative delay;
1319 if (NULL == t->kx_ctx || NULL != t->kx_ctx->finish_task)
1322 if (is_key_null (&t->kx_ctx->e_key_old))
1324 t->kx_ctx->finish_task = GNUNET_SCHEDULER_add_now (finish_kx, t);
1328 delay = GNUNET_TIME_relative_divide (rekey_period, 4);
1329 delay = GNUNET_TIME_relative_min (delay, GNUNET_TIME_UNIT_MINUTES);
1331 t->kx_ctx->finish_task = GNUNET_SCHEDULER_add_delayed (delay, finish_kx, t);
1337 * Pick a connection on which send the next data message.
1339 * @param t Tunnel on which to send the message.
1341 * @return The connection on which to send the next message.
1343 static struct CadetConnection *
1344 tunnel_get_connection (struct CadetTunnel *t)
1346 struct CadetTConnection *iter;
1347 struct CadetConnection *best;
1349 unsigned int lowest_q;
1351 LOG (GNUNET_ERROR_TYPE_DEBUG, "tunnel_get_connection %s\n", GCT_2s (t));
1353 lowest_q = UINT_MAX;
1354 for (iter = t->connection_head; NULL != iter; iter = iter->next)
1356 LOG (GNUNET_ERROR_TYPE_DEBUG, " connection %s: %u\n",
1357 GCC_2s (iter->c), GCC_get_state (iter->c));
1358 if (CADET_CONNECTION_READY == GCC_get_state (iter->c))
1360 qn = GCC_get_qn (iter->c, GCC_is_origin (iter->c, GNUNET_YES));
1361 LOG (GNUNET_ERROR_TYPE_DEBUG, " q_n %u, \n", qn);
1369 LOG (GNUNET_ERROR_TYPE_DEBUG, " selected: connection %s\n", GCC_2s (best));
1375 * Callback called when a queued message is sent.
1377 * Calculates the average time and connection packet tracking.
1379 * @param cls Closure (TunnelQueue handle).
1380 * @param c Connection this message was on.
1381 * @param q Connection queue handle (unused).
1382 * @param type Type of message sent.
1383 * @param fwd Was this a FWD going message?
1384 * @param size Size of the message.
1387 tun_message_sent (void *cls,
1388 struct CadetConnection *c,
1389 struct CadetConnectionQueue *q,
1390 uint16_t type, int fwd, size_t size)
1392 struct CadetTunnelQueue *qt = cls;
1393 struct CadetTunnel *t;
1395 LOG (GNUNET_ERROR_TYPE_DEBUG, "tun_message_sent\n");
1397 GNUNET_assert (NULL != qt->cont);
1398 t = NULL == c ? NULL : GCC_get_tunnel (c);
1399 qt->cont (qt->cont_cls, t, qt, type, size);
1405 count_queued_data (const struct CadetTunnel *t)
1407 struct CadetTunnelDelayed *iter;
1410 for (count = 0, iter = t->tq_head; iter != NULL; iter = iter->next)
1417 * Delete a queued message: either was sent or the channel was destroyed
1418 * before the tunnel's key exchange had a chance to finish.
1420 * @param tqd Delayed queue handle.
1423 unqueue_data (struct CadetTunnelDelayed *tqd)
1425 GNUNET_CONTAINER_DLL_remove (tqd->t->tq_head, tqd->t->tq_tail, tqd);
1431 * Cache a message to be sent once tunnel is online.
1433 * @param t Tunnel to hold the message.
1434 * @param msg Message itself (copy will be made).
1436 static struct CadetTunnelDelayed *
1437 queue_data (struct CadetTunnel *t, const struct GNUNET_MessageHeader *msg)
1439 struct CadetTunnelDelayed *tqd;
1440 uint16_t size = ntohs (msg->size);
1442 LOG (GNUNET_ERROR_TYPE_DEBUG, "queue data on Tunnel %s\n", GCT_2s (t));
1444 if (GNUNET_YES == is_ready (t))
1450 tqd = GNUNET_malloc (sizeof (struct CadetTunnelDelayed) + size);
1453 memcpy (&tqd[1], msg, size);
1454 GNUNET_CONTAINER_DLL_insert_tail (t->tq_head, t->tq_tail, tqd);
1460 * Sends an already built message on a tunnel, encrypting it and
1461 * choosing the best connection.
1463 * @param message Message to send. Function modifies it.
1464 * @param t Tunnel on which this message is transmitted.
1465 * @param c Connection to use (autoselect if NULL).
1466 * @param force Force the tunnel to take the message (buffer overfill).
1467 * @param cont Continuation to call once message is really sent.
1468 * @param cont_cls Closure for @c cont.
1469 * @param existing_q In case this a transmission of previously queued data,
1470 * this should be TunnelQueue given to the client.
1473 * @return Handle to cancel message.
1474 * NULL if @c cont is NULL or an error happens and message is dropped.
1476 static struct CadetTunnelQueue *
1477 send_prebuilt_message (const struct GNUNET_MessageHeader *message,
1478 struct CadetTunnel *t, struct CadetConnection *c,
1479 int force, GCT_sent cont, void *cont_cls,
1480 struct CadetTunnelQueue *existing_q)
1482 struct CadetTunnelQueue *tq;
1483 struct GNUNET_CADET_Encrypted *msg;
1484 size_t size = ntohs (message->size);
1485 char cbuf[sizeof (struct GNUNET_CADET_Encrypted) + size];
1492 LOG (GNUNET_ERROR_TYPE_DEBUG, "GMT Send on Tunnel %s\n", GCT_2s (t));
1494 if (GNUNET_NO == is_ready (t))
1496 struct CadetTunnelDelayed *tqd;
1497 /* A non null existing_q indicates sending of queued data.
1498 * Should only happen after tunnel becomes ready.
1500 GNUNET_assert (NULL == existing_q);
1501 tqd = queue_data (t, message);
1504 tq = GNUNET_new (struct CadetTunnelQueue);
1508 tq->cont_cls = cont_cls;
1512 GNUNET_assert (GNUNET_NO == GCT_is_loopback (t));
1514 iv = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX);
1515 msg = (struct GNUNET_CADET_Encrypted *) cbuf;
1516 msg->header.type = htons (GNUNET_MESSAGE_TYPE_CADET_ENCRYPTED);
1519 if (CADET_Axolotl == t->enc_type)
1520 esize = t_ax_encrypt (t, &msg[1], message, size);
1522 esize = t_encrypt (t, &msg[1], message, size, iv, GNUNET_NO);
1523 GNUNET_assert (esize == size);
1524 t_hmac (&msg[1], size, iv, select_key (t), &msg->hmac);
1525 msg->header.size = htons (sizeof (struct GNUNET_CADET_Encrypted) + size);
1528 c = tunnel_get_connection (t);
1531 /* Why is tunnel 'ready'? Should have been queued! */
1532 if (NULL != t->destroy_task)
1535 GCT_debug (t, GNUNET_ERROR_TYPE_WARNING);
1537 return NULL; /* Drop... */
1541 type = ntohs (message->type);
1544 case GNUNET_MESSAGE_TYPE_CADET_DATA:
1545 case GNUNET_MESSAGE_TYPE_CADET_DATA_ACK:
1546 if (GNUNET_MESSAGE_TYPE_CADET_DATA == type)
1547 mid = ntohl (((struct GNUNET_CADET_Data *) message)->mid);
1549 mid = ntohl (((struct GNUNET_CADET_DataACK *) message)->mid);
1551 case GNUNET_MESSAGE_TYPE_CADET_KEEPALIVE:
1552 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_CREATE:
1553 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_DESTROY:
1554 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_ACK:
1555 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_NACK:
1556 msg->cid = *GCC_get_id (c);
1557 msg->ttl = htonl (default_ttl);
1561 LOG (GNUNET_ERROR_TYPE_ERROR, "type %s not valid\n", GC_m2s (type));
1563 LOG (GNUNET_ERROR_TYPE_DEBUG, "type %s\n", GC_m2s (type));
1565 fwd = GCC_is_origin (c, GNUNET_YES);
1569 GNUNET_break (NULL == GCC_send_prebuilt_message (&msg->header, type, mid, c,
1570 fwd, force, NULL, NULL));
1573 if (NULL == existing_q)
1575 tq = GNUNET_new (struct CadetTunnelQueue); /* FIXME valgrind: leak*/
1582 tq->cq = GCC_send_prebuilt_message (&msg->header, type, mid, c, fwd, force,
1583 &tun_message_sent, tq);
1584 GNUNET_assert (NULL != tq->cq);
1586 tq->cont_cls = cont_cls;
1593 * Send all cached messages that we can, tunnel is online.
1595 * @param t Tunnel that holds the messages. Cannot be loopback.
1598 send_queued_data (struct CadetTunnel *t)
1600 struct CadetTunnelDelayed *tqd;
1601 struct CadetTunnelDelayed *next;
1604 LOG (GNUNET_ERROR_TYPE_INFO, "Send queued data, tunnel %s\n", GCT_2s (t));
1606 if (GCT_is_loopback (t))
1612 if (GNUNET_NO == is_ready (t))
1614 LOG (GNUNET_ERROR_TYPE_DEBUG, " not ready yet: %s/%s\n",
1615 estate2s (t->estate), cstate2s (t->cstate));
1619 room = GCT_get_connections_buffer (t);
1620 LOG (GNUNET_ERROR_TYPE_DEBUG, " buffer space: %u\n", room);
1621 LOG (GNUNET_ERROR_TYPE_DEBUG, " tq head: %p\n", t->tq_head);
1622 for (tqd = t->tq_head; NULL != tqd && room > 0; tqd = next)
1624 LOG (GNUNET_ERROR_TYPE_DEBUG, " sending queued data\n");
1627 send_prebuilt_message ((struct GNUNET_MessageHeader *) &tqd[1],
1628 tqd->t, NULL, GNUNET_YES,
1629 NULL != tqd->tq ? tqd->tq->cont : NULL,
1630 NULL != tqd->tq ? tqd->tq->cont_cls : NULL,
1634 LOG (GNUNET_ERROR_TYPE_DEBUG, "GCT_send_queued_data end\n", GCP_2s (t->peer));
1639 * Callback called when a queued message is sent.
1641 * @param cls Closure.
1642 * @param c Connection this message was on.
1643 * @param type Type of message sent.
1644 * @param fwd Was this a FWD going message?
1645 * @param size Size of the message.
1648 ephm_sent (void *cls,
1649 struct CadetConnection *c,
1650 struct CadetConnectionQueue *q,
1651 uint16_t type, int fwd, size_t size)
1653 struct CadetTunnel *t = cls;
1654 LOG (GNUNET_ERROR_TYPE_DEBUG, "ephemeral sent %s\n", GC_m2s (type));
1659 * Callback called when a queued message is sent.
1661 * @param cls Closure.
1662 * @param c Connection this message was on.
1663 * @param type Type of message sent.
1664 * @param fwd Was this a FWD going message?
1665 * @param size Size of the message.
1668 pong_sent (void *cls,
1669 struct CadetConnection *c,
1670 struct CadetConnectionQueue *q,
1671 uint16_t type, int fwd, size_t size)
1673 struct CadetTunnel *t = cls;
1674 LOG (GNUNET_ERROR_TYPE_DEBUG, "pong_sent %s\n", GC_m2s (type));
1680 * Sends key exchange message on a tunnel, choosing the best connection.
1681 * Should not be called on loopback tunnels.
1683 * @param t Tunnel on which this message is transmitted.
1684 * @param message Message to send. Function modifies it.
1686 * @return Handle to the message in the connection queue.
1688 static struct CadetConnectionQueue *
1689 send_kx (struct CadetTunnel *t,
1690 const struct GNUNET_MessageHeader *message)
1692 struct CadetConnection *c;
1693 struct GNUNET_CADET_KX *msg;
1694 size_t size = ntohs (message->size);
1695 char cbuf[sizeof (struct GNUNET_CADET_KX) + size];
1700 LOG (GNUNET_ERROR_TYPE_DEBUG, "GMT KX on Tunnel %s\n", GCT_2s (t));
1702 /* Avoid loopback. */
1703 if (GCT_is_loopback (t))
1708 type = ntohs (message->type);
1710 /* Even if tunnel is "being destroyed", send anyway.
1711 * Could be a response to a rekey initiated by remote peer,
1712 * who is trying to create a new channel!
1715 /* Must have a connection, or be looking for one. */
1716 if (NULL == t->connection_head)
1718 LOG (GNUNET_ERROR_TYPE_DEBUG, "%s with no connection\n", GC_m2s (type));
1719 if (CADET_TUNNEL_SEARCHING != t->cstate)
1722 GCT_debug (t, GNUNET_ERROR_TYPE_ERROR);
1723 GCP_debug (t->peer, GNUNET_ERROR_TYPE_ERROR);
1728 msg = (struct GNUNET_CADET_KX *) cbuf;
1729 msg->header.type = htons (GNUNET_MESSAGE_TYPE_CADET_KX);
1730 msg->header.size = htons (sizeof (struct GNUNET_CADET_KX) + size);
1731 c = tunnel_get_connection (t);
1734 if (NULL == t->destroy_task && CADET_TUNNEL_READY == t->cstate)
1737 GCT_debug (t, GNUNET_ERROR_TYPE_ERROR);
1743 case GNUNET_MESSAGE_TYPE_CADET_KX_EPHEMERAL:
1744 case GNUNET_MESSAGE_TYPE_CADET_AX_KX:
1745 GNUNET_assert (NULL == t->ephm_h);
1748 case GNUNET_MESSAGE_TYPE_CADET_KX_PONG:
1749 GNUNET_assert (NULL == t->pong_h);
1754 LOG (GNUNET_ERROR_TYPE_DEBUG, "unkown type %s\n", GC_m2s (type));
1757 memcpy (&msg[1], message, size);
1759 fwd = GCC_is_origin (c, GNUNET_YES);
1761 return GCC_send_prebuilt_message (&msg->header, type, 0, c,
1768 * Send the ephemeral key on a tunnel.
1770 * @param t Tunnel on which to send the key.
1773 send_ephemeral (struct CadetTunnel *t)
1775 LOG (GNUNET_ERROR_TYPE_INFO, "===> EPHM for %s\n", GCT_2s (t));
1776 if (NULL != t->ephm_h)
1778 LOG (GNUNET_ERROR_TYPE_INFO, " already queued\n");
1782 otr_kx_msg.sender_status = htonl (t->estate);
1783 otr_kx_msg.iv = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX);
1784 otr_kx_msg.nonce = t->kx_ctx->challenge;
1785 LOG (GNUNET_ERROR_TYPE_DEBUG, " send nonce c %u\n", otr_kx_msg.nonce);
1786 t_encrypt (t, &otr_kx_msg.nonce, &otr_kx_msg.nonce,
1787 ping_encryption_size(), otr_kx_msg.iv, GNUNET_YES);
1788 LOG (GNUNET_ERROR_TYPE_DEBUG, " send nonce e %u\n", otr_kx_msg.nonce);
1789 t->ephm_h = send_kx (t, &otr_kx_msg.header);
1794 * Send a pong message on a tunnel.
1796 * @param t Tunnel on which to send the pong.
1797 * @param challenge Value sent in the ping that we have to send back.
1800 send_pong (struct CadetTunnel *t, uint32_t challenge)
1802 struct GNUNET_CADET_KX_Pong msg;
1804 LOG (GNUNET_ERROR_TYPE_INFO, "===> PONG for %s\n", GCT_2s (t));
1805 if (NULL != t->pong_h)
1807 LOG (GNUNET_ERROR_TYPE_INFO, " already queued\n");
1810 msg.header.size = htons (sizeof (msg));
1811 msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_KX_PONG);
1812 msg.iv = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX);
1813 msg.nonce = challenge;
1814 LOG (GNUNET_ERROR_TYPE_DEBUG, " sending %u\n", msg.nonce);
1815 t_encrypt (t, &msg.nonce, &msg.nonce,
1816 sizeof (msg.nonce), msg.iv, GNUNET_YES);
1817 LOG (GNUNET_ERROR_TYPE_DEBUG, " e sending %u\n", msg.nonce);
1819 t->pong_h = send_kx (t, &msg.header);
1824 * Initiate a rekey with the remote peer.
1826 * @param cls Closure (tunnel).
1827 * @param tc TaskContext.
1830 rekey_tunnel (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
1832 struct CadetTunnel *t = cls;
1834 t->rekey_task = NULL;
1836 LOG (GNUNET_ERROR_TYPE_INFO, "Re-key Tunnel %s\n", GCT_2s (t));
1837 if (NULL != tc && 0 != (GNUNET_SCHEDULER_REASON_SHUTDOWN & tc->reason))
1840 GNUNET_assert (NULL != t->kx_ctx);
1841 struct GNUNET_TIME_Relative duration;
1843 duration = GNUNET_TIME_absolute_get_duration (t->kx_ctx->rekey_start_time);
1844 LOG (GNUNET_ERROR_TYPE_DEBUG, " kx started %s ago\n",
1845 GNUNET_STRINGS_relative_time_to_string (duration, GNUNET_YES));
1847 // FIXME make duration of old keys configurable
1848 if (duration.rel_value_us >= GNUNET_TIME_UNIT_MINUTES.rel_value_us)
1850 LOG (GNUNET_ERROR_TYPE_DEBUG, " deleting old keys\n");
1851 memset (&t->kx_ctx->d_key_old, 0, sizeof (t->kx_ctx->d_key_old));
1852 memset (&t->kx_ctx->e_key_old, 0, sizeof (t->kx_ctx->e_key_old));
1859 case CADET_TUNNEL_KEY_UNINITIALIZED:
1860 GCT_change_estate (t, CADET_TUNNEL_KEY_SENT);
1863 case CADET_TUNNEL_KEY_SENT:
1866 case CADET_TUNNEL_KEY_OK:
1868 * - state should have changed during rekey_iterator
1869 * - task should have been canceled at pong_handle
1872 GCT_change_estate (t, CADET_TUNNEL_KEY_REKEY);
1875 case CADET_TUNNEL_KEY_PING:
1876 case CADET_TUNNEL_KEY_REKEY:
1880 LOG (GNUNET_ERROR_TYPE_DEBUG, "Unexpected state %u\n", t->estate);
1883 // FIXME exponential backoff
1884 struct GNUNET_TIME_Relative delay;
1886 delay = GNUNET_TIME_relative_divide (rekey_period, 16);
1887 delay = GNUNET_TIME_relative_min (delay, REKEY_WAIT);
1888 LOG (GNUNET_ERROR_TYPE_DEBUG, " next call in %s\n",
1889 GNUNET_STRINGS_relative_time_to_string (delay, GNUNET_YES));
1890 t->rekey_task = GNUNET_SCHEDULER_add_delayed (delay, &rekey_tunnel, t);
1895 * Our ephemeral key has changed, create new session key on all tunnels.
1897 * Each tunnel will start the Key Exchange with a random delay between
1898 * 0 and number_of_tunnels*100 milliseconds, so there are 10 key exchanges
1899 * per second, on average.
1901 * @param cls Closure (size of the hashmap).
1902 * @param key Current public key.
1903 * @param value Value in the hash map (tunnel).
1905 * @return #GNUNET_YES, so we should continue to iterate,
1908 rekey_iterator (void *cls,
1909 const struct GNUNET_PeerIdentity *key,
1912 struct CadetTunnel *t = value;
1913 struct GNUNET_TIME_Relative delay;
1914 long n = (long) cls;
1917 if (NULL != t->rekey_task)
1920 if (GNUNET_YES == GCT_is_loopback (t))
1923 if (CADET_OTR != t->enc_type)
1926 r = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK, (uint32_t) n * 100);
1927 delay = GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MILLISECONDS, r);
1928 t->rekey_task = GNUNET_SCHEDULER_add_delayed (delay, &rekey_tunnel, t);
1930 GCT_change_estate (t, CADET_TUNNEL_KEY_REKEY);
1937 * Create a new ephemeral key and key message, schedule next rekeying.
1939 * @param cls Closure (unused).
1940 * @param tc TaskContext.
1943 global_otr_rekey (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
1945 struct GNUNET_TIME_Absolute time;
1950 if (0 != (GNUNET_SCHEDULER_REASON_SHUTDOWN & tc->reason))
1953 GNUNET_free_non_null (otr_ephemeral_key);
1954 otr_ephemeral_key = GNUNET_CRYPTO_ecdhe_key_create ();
1956 time = GNUNET_TIME_absolute_get ();
1957 otr_kx_msg.creation_time = GNUNET_TIME_absolute_hton (time);
1958 time = GNUNET_TIME_absolute_add (time, rekey_period);
1959 time = GNUNET_TIME_absolute_add (time, GNUNET_TIME_UNIT_MINUTES);
1960 otr_kx_msg.expiration_time = GNUNET_TIME_absolute_hton (time);
1961 GNUNET_CRYPTO_ecdhe_key_get_public (otr_ephemeral_key, &otr_kx_msg.ephemeral_key);
1962 LOG (GNUNET_ERROR_TYPE_INFO, "GLOBAL OTR RE-KEY, NEW EPHM: %s\n",
1963 GNUNET_h2s ((struct GNUNET_HashCode *) &otr_kx_msg.ephemeral_key));
1965 GNUNET_assert (GNUNET_OK ==
1966 GNUNET_CRYPTO_eddsa_sign (id_key,
1967 &otr_kx_msg.purpose,
1968 &otr_kx_msg.signature));
1970 n = (long) GNUNET_CONTAINER_multipeermap_size (tunnels);
1971 GNUNET_CONTAINER_multipeermap_iterate (tunnels, &rekey_iterator, (void *) n);
1973 rekey_task = GNUNET_SCHEDULER_add_delayed (rekey_period,
1974 &global_otr_rekey, NULL);
1979 * Called only on shutdown, destroy every tunnel.
1981 * @param cls Closure (unused).
1982 * @param key Current public key.
1983 * @param value Value in the hash map (tunnel).
1985 * @return #GNUNET_YES, so we should continue to iterate,
1988 destroy_iterator (void *cls,
1989 const struct GNUNET_PeerIdentity *key,
1992 struct CadetTunnel *t = value;
1994 LOG (GNUNET_ERROR_TYPE_DEBUG, "GCT_shutdown destroying tunnel at %p\n", t);
2001 * Notify remote peer that we don't know a channel he is talking about,
2002 * probably CHANNEL_DESTROY was missed.
2004 * @param t Tunnel on which to notify.
2005 * @param gid ID of the channel.
2008 send_channel_destroy (struct CadetTunnel *t, unsigned int gid)
2010 struct GNUNET_CADET_ChannelManage msg;
2012 msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_CHANNEL_DESTROY);
2013 msg.header.size = htons (sizeof (msg));
2014 msg.chid = htonl (gid);
2016 LOG (GNUNET_ERROR_TYPE_DEBUG,
2017 "WARNING destroying unknown channel %u on tunnel %s\n",
2019 send_prebuilt_message (&msg.header, t, NULL, GNUNET_YES, NULL, NULL, NULL);
2024 * Demultiplex data per channel and call appropriate channel handler.
2026 * @param t Tunnel on which the data came.
2027 * @param msg Data message.
2028 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
2029 * #GNUNET_YES if message is FWD on the respective channel (loopback)
2030 * #GNUNET_NO if message is BCK on the respective channel (loopback)
2031 * #GNUNET_SYSERR if message on a one-ended channel (remote)
2034 handle_data (struct CadetTunnel *t,
2035 const struct GNUNET_CADET_Data *msg,
2038 struct CadetChannel *ch;
2042 size = ntohs (msg->header.size);
2044 sizeof (struct GNUNET_CADET_Data) +
2045 sizeof (struct GNUNET_MessageHeader))
2050 LOG (GNUNET_ERROR_TYPE_DEBUG, " payload of type %s\n",
2051 GC_m2s (ntohs (msg[1].header.type)));
2054 ch = GCT_get_channel (t, ntohl (msg->chid));
2057 GNUNET_STATISTICS_update (stats, "# data on unknown channel",
2059 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel 0x%X unknown\n",
2061 send_channel_destroy (t, ntohl (msg->chid));
2065 GCCH_handle_data (ch, msg, fwd);
2070 * Demultiplex data ACKs per channel and update appropriate channel buffer info.
2072 * @param t Tunnel on which the DATA ACK came.
2073 * @param msg DATA ACK message.
2074 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
2075 * #GNUNET_YES if message is FWD on the respective channel (loopback)
2076 * #GNUNET_NO if message is BCK on the respective channel (loopback)
2077 * #GNUNET_SYSERR if message on a one-ended channel (remote)
2080 handle_data_ack (struct CadetTunnel *t,
2081 const struct GNUNET_CADET_DataACK *msg,
2084 struct CadetChannel *ch;
2088 size = ntohs (msg->header.size);
2089 if (size != sizeof (struct GNUNET_CADET_DataACK))
2096 ch = GCT_get_channel (t, ntohl (msg->chid));
2099 GNUNET_STATISTICS_update (stats, "# data ack on unknown channel",
2101 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel %u unknown\n",
2106 GCCH_handle_data_ack (ch, msg, fwd);
2111 * Handle channel create.
2113 * @param t Tunnel on which the data came.
2114 * @param msg Data message.
2117 handle_ch_create (struct CadetTunnel *t,
2118 const struct GNUNET_CADET_ChannelCreate *msg)
2120 struct CadetChannel *ch;
2124 size = ntohs (msg->header.size);
2125 if (size != sizeof (struct GNUNET_CADET_ChannelCreate))
2132 ch = GCT_get_channel (t, ntohl (msg->chid));
2133 if (NULL != ch && ! GCT_is_loopback (t))
2135 /* Probably a retransmission, safe to ignore */
2136 LOG (GNUNET_ERROR_TYPE_DEBUG, " already exists...\n");
2138 ch = GCCH_handle_create (t, msg);
2140 GCT_add_channel (t, ch);
2146 * Handle channel NACK: check correctness and call channel handler for NACKs.
2148 * @param t Tunnel on which the NACK came.
2149 * @param msg NACK message.
2152 handle_ch_nack (struct CadetTunnel *t,
2153 const struct GNUNET_CADET_ChannelManage *msg)
2155 struct CadetChannel *ch;
2159 size = ntohs (msg->header.size);
2160 if (size != sizeof (struct GNUNET_CADET_ChannelManage))
2167 ch = GCT_get_channel (t, ntohl (msg->chid));
2170 GNUNET_STATISTICS_update (stats, "# channel NACK on unknown channel",
2172 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel %u unknown\n",
2177 GCCH_handle_nack (ch);
2182 * Handle a CHANNEL ACK (SYNACK/ACK).
2184 * @param t Tunnel on which the CHANNEL ACK came.
2185 * @param msg CHANNEL ACK message.
2186 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
2187 * #GNUNET_YES if message is FWD on the respective channel (loopback)
2188 * #GNUNET_NO if message is BCK on the respective channel (loopback)
2189 * #GNUNET_SYSERR if message on a one-ended channel (remote)
2192 handle_ch_ack (struct CadetTunnel *t,
2193 const struct GNUNET_CADET_ChannelManage *msg,
2196 struct CadetChannel *ch;
2200 size = ntohs (msg->header.size);
2201 if (size != sizeof (struct GNUNET_CADET_ChannelManage))
2208 ch = GCT_get_channel (t, ntohl (msg->chid));
2211 GNUNET_STATISTICS_update (stats, "# channel ack on unknown channel",
2213 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel %u unknown\n",
2218 GCCH_handle_ack (ch, msg, fwd);
2223 * Handle a channel destruction message.
2225 * @param t Tunnel on which the message came.
2226 * @param msg Channel destroy message.
2227 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
2228 * #GNUNET_YES if message is FWD on the respective channel (loopback)
2229 * #GNUNET_NO if message is BCK on the respective channel (loopback)
2230 * #GNUNET_SYSERR if message on a one-ended channel (remote)
2233 handle_ch_destroy (struct CadetTunnel *t,
2234 const struct GNUNET_CADET_ChannelManage *msg,
2237 struct CadetChannel *ch;
2241 size = ntohs (msg->header.size);
2242 if (size != sizeof (struct GNUNET_CADET_ChannelManage))
2249 ch = GCT_get_channel (t, ntohl (msg->chid));
2252 /* Probably a retransmission, safe to ignore */
2256 GCCH_handle_destroy (ch, msg, fwd);
2261 * Create a new Axolotl ephemeral (ratchet) key.
2266 new_ephemeral (struct CadetTunnel *t)
2268 GNUNET_free_non_null (t->ax->DHRs);
2269 t->ax->DHRs = GNUNET_CRYPTO_ecdhe_key_create();
2274 * Free Axolotl data.
2279 destroy_ax (struct CadetTunnel *t)
2284 GNUNET_free_non_null (t->ax->DHRs);
2285 GNUNET_free_non_null (t->ax->kx_0);
2287 GNUNET_free (t->ax);
2294 * The peer's ephemeral key has changed: update the symmetrical keys.
2296 * @param t Tunnel this message came on.
2297 * @param msg Key eXchange message.
2300 handle_ephemeral (struct CadetTunnel *t,
2301 const struct GNUNET_CADET_KX_Ephemeral *msg)
2303 LOG (GNUNET_ERROR_TYPE_INFO, "<=== EPHM for %s\n", GCT_2s (t));
2305 if (GNUNET_OK != check_ephemeral (t, msg))
2307 GNUNET_break_op (0);
2311 /* If we get a proper OTR-style ephemeral, fallback to old crypto. */
2315 t->enc_type = CADET_OTR;
2316 if (NULL != t->rekey_task)
2317 GNUNET_SCHEDULER_cancel (t->rekey_task);
2319 rekey_tunnel (t, NULL);
2323 * If the key is different from what we know, derive the new E/D keys.
2324 * Else destroy the rekey ctx (duplicate EPHM after successful KX).
2326 if (0 != memcmp (&t->peers_ephemeral_key, &msg->ephemeral_key,
2327 sizeof (msg->ephemeral_key)))
2329 #if DUMP_KEYS_TO_STDERR
2330 LOG (GNUNET_ERROR_TYPE_INFO, "OLD: %s\n",
2331 GNUNET_h2s ((struct GNUNET_HashCode *) &t->peers_ephemeral_key));
2332 LOG (GNUNET_ERROR_TYPE_INFO, "NEW: %s\n",
2333 GNUNET_h2s ((struct GNUNET_HashCode *) &msg->ephemeral_key));
2335 t->peers_ephemeral_key = msg->ephemeral_key;
2339 if (CADET_TUNNEL_KEY_OK == t->estate)
2341 GCT_change_estate (t, CADET_TUNNEL_KEY_REKEY);
2343 if (NULL != t->rekey_task)
2344 GNUNET_SCHEDULER_cancel (t->rekey_task);
2345 t->rekey_task = GNUNET_SCHEDULER_add_now (rekey_tunnel, t);
2347 if (CADET_TUNNEL_KEY_SENT == t->estate)
2349 LOG (GNUNET_ERROR_TYPE_DEBUG, " our key was sent, sending challenge\n");
2351 GCT_change_estate (t, CADET_TUNNEL_KEY_PING);
2354 if (CADET_TUNNEL_KEY_UNINITIALIZED != ntohl(msg->sender_status))
2358 LOG (GNUNET_ERROR_TYPE_DEBUG, " recv nonce e %u\n", msg->nonce);
2359 t_decrypt (t, &nonce, &msg->nonce, ping_encryption_size (), msg->iv);
2360 LOG (GNUNET_ERROR_TYPE_DEBUG, " recv nonce c %u\n", nonce);
2361 send_pong (t, nonce);
2367 * Peer has answer to our challenge.
2368 * If answer is successful, consider the key exchange finished and clean
2369 * up all related state.
2371 * @param t Tunnel this message came on.
2372 * @param msg Key eXchange Pong message.
2375 handle_pong (struct CadetTunnel *t, const struct GNUNET_CADET_KX_Pong *msg)
2379 LOG (GNUNET_ERROR_TYPE_INFO, "<=== PONG for %s\n", GCT_2s (t));
2380 if (NULL == t->rekey_task)
2382 GNUNET_STATISTICS_update (stats, "# duplicate PONG messages", 1, GNUNET_NO);
2385 if (NULL == t->kx_ctx)
2387 GNUNET_STATISTICS_update (stats, "# stray PONG messages", 1, GNUNET_NO);
2391 t_decrypt (t, &challenge, &msg->nonce, sizeof (uint32_t), msg->iv);
2392 if (challenge != t->kx_ctx->challenge)
2394 LOG (GNUNET_ERROR_TYPE_WARNING, "Wrong PONG challenge on %s\n", GCT_2s (t));
2395 LOG (GNUNET_ERROR_TYPE_DEBUG, "PONG: %u (e: %u). Expected: %u.\n",
2396 challenge, msg->nonce, t->kx_ctx->challenge);
2400 GNUNET_SCHEDULER_cancel (t->rekey_task);
2401 t->rekey_task = NULL;
2403 /* Don't free the old keys right away, but after a delay.
2404 * Rationale: the KX could have happened over a very fast connection,
2405 * with payload traffic still signed with the old key stuck in a slower
2407 * Don't keep the keys longer than 1/4 the rekey period, and no longer than
2411 GCT_change_estate (t, CADET_TUNNEL_KEY_OK);
2416 * Handle Axolotl handshake.
2418 * @param t Tunnel this message came on.
2419 * @param msg Key eXchange Pong message.
2422 handle_kx_ax (struct CadetTunnel *t, const struct GNUNET_CADET_AX_KX *msg)
2424 struct CadetTunnelAxolotl *ax;
2425 struct GNUNET_HashCode key_material[3];
2426 struct GNUNET_CRYPTO_SymmetricSessionKey keys[5];
2427 const struct GNUNET_CRYPTO_EcdhePublicKey *pub;
2428 const struct GNUNET_CRYPTO_EcdhePrivateKey *priv;
2429 const char salt[] = "CADET Axolotl salt";
2430 const struct GNUNET_PeerIdentity *pid;
2433 LOG (GNUNET_ERROR_TYPE_INFO, "<=== AX_KX on %s\n", GCT_2s (t));
2437 /* Something is wrong if ax is NULL. Whose fault it is? */
2438 GNUNET_break_op (CADET_OTR == t->enc_type);
2439 GNUNET_break (CADET_Axolotl == t->enc_type);
2443 if (GNUNET_OK != GCP_check_key (t->peer, &msg->permanent_key,
2444 &msg->purpose, &msg->signature))
2446 GNUNET_break_op (0);
2450 pid = GCT_get_destination (t);
2451 if (0 > GNUNET_CRYPTO_cmp_peer_identity (&my_full_id, pid))
2452 am_I_alice = GNUNET_YES;
2453 else if (0 < GNUNET_CRYPTO_cmp_peer_identity (&my_full_id, pid))
2454 am_I_alice = GNUNET_NO;
2457 GNUNET_break_op (0);
2461 LOG (GNUNET_ERROR_TYPE_INFO, " is Alice? %s\n", am_I_alice ? "YES" : "NO");
2464 ax->DHRr = msg->ratchet_key;
2467 if (GNUNET_YES == am_I_alice)
2469 priv = ax_key; /* A */
2470 pub = &msg->ephemeral_key; /* B0 */
2474 priv = ax->kx_0; /* B0 */
2475 pub = &msg->permanent_key; /* A */
2477 GNUNET_CRYPTO_ecc_ecdh (priv, pub, &key_material[0]);
2480 if (GNUNET_YES == am_I_alice)
2482 priv = ax->kx_0; /* A0 */
2483 pub = &msg->permanent_key; /* B */
2487 priv = ax_key; /* B */
2488 pub = &msg->ephemeral_key; /* A0 */
2490 GNUNET_CRYPTO_ecc_ecdh (priv, pub, &key_material[1]);
2493 priv = ax->kx_0; /* A0 or B0 */
2494 pub = &msg->ephemeral_key; /* B0 or A0 */
2495 GNUNET_CRYPTO_ecc_ecdh (priv, pub, &key_material[2]);
2497 #if DUMP_KEYS_TO_STDERR
2500 for (i = 0; i < 3; i++)
2501 LOG (GNUNET_ERROR_TYPE_INFO, "km[%u]: %s\n",
2502 i, GNUNET_h2s (&key_material[i]));
2507 GNUNET_CRYPTO_kdf (keys, sizeof (keys),
2508 salt, sizeof (salt),
2509 &key_material, sizeof (key_material), NULL);
2512 if (GNUNET_YES == am_I_alice)
2518 ax->ratchet_flag = GNUNET_YES;
2526 ax->ratchet_flag = GNUNET_NO;
2528 GCT_change_estate (t, CADET_TUNNEL_KEY_OK);
2533 * Demultiplex by message type and call appropriate handler for a message
2534 * towards a channel of a local tunnel.
2536 * @param t Tunnel this message came on.
2537 * @param msgh Message header.
2538 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
2539 * #GNUNET_YES if message is FWD on the respective channel (loopback)
2540 * #GNUNET_NO if message is BCK on the respective channel (loopback)
2541 * #GNUNET_SYSERR if message on a one-ended channel (remote)
2544 handle_decrypted (struct CadetTunnel *t,
2545 const struct GNUNET_MessageHeader *msgh,
2550 type = ntohs (msgh->type);
2551 LOG (GNUNET_ERROR_TYPE_INFO, "<=== %s on %s\n", GC_m2s (type), GCT_2s (t));
2555 case GNUNET_MESSAGE_TYPE_CADET_KEEPALIVE:
2556 /* Do nothing, connection aleady got updated. */
2557 GNUNET_STATISTICS_update (stats, "# keepalives received", 1, GNUNET_NO);
2560 case GNUNET_MESSAGE_TYPE_CADET_DATA:
2561 /* Don't send hop ACK, wait for client to ACK */
2562 handle_data (t, (struct GNUNET_CADET_Data *) msgh, fwd);
2565 case GNUNET_MESSAGE_TYPE_CADET_DATA_ACK:
2566 handle_data_ack (t, (struct GNUNET_CADET_DataACK *) msgh, fwd);
2569 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_CREATE:
2570 handle_ch_create (t, (struct GNUNET_CADET_ChannelCreate *) msgh);
2573 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_NACK:
2574 handle_ch_nack (t, (struct GNUNET_CADET_ChannelManage *) msgh);
2577 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_ACK:
2578 handle_ch_ack (t, (struct GNUNET_CADET_ChannelManage *) msgh, fwd);
2581 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_DESTROY:
2582 handle_ch_destroy (t, (struct GNUNET_CADET_ChannelManage *) msgh, fwd);
2586 GNUNET_break_op (0);
2587 LOG (GNUNET_ERROR_TYPE_WARNING,
2588 "end-to-end message not known (%u)\n",
2589 ntohs (msgh->type));
2590 GCT_debug (t, GNUNET_ERROR_TYPE_WARNING);
2594 /******************************************************************************/
2595 /******************************** API ***********************************/
2596 /******************************************************************************/
2598 * Decrypt old format and demultiplex by message type. Call appropriate handler
2599 * for a message towards a channel of a local tunnel.
2601 * @param t Tunnel this message came on.
2602 * @param msg Message header.
2605 GCT_handle_encrypted (struct CadetTunnel *t,
2606 const struct GNUNET_MessageHeader *msg)
2608 size_t size = ntohs (msg->size);
2609 size_t payload_size;
2612 uint16_t type = ntohs (msg->type);
2613 struct GNUNET_MessageHeader *msgh;
2616 if (GNUNET_MESSAGE_TYPE_CADET_ENCRYPTED == type)
2618 const struct GNUNET_CADET_Encrypted *emsg;
2620 emsg = (struct GNUNET_CADET_Encrypted *) msg;
2621 payload_size = size - sizeof (struct GNUNET_CADET_Encrypted);
2622 decrypted_size = t_decrypt_and_validate (t, cbuf, &emsg[1], payload_size,
2623 emsg->iv, &emsg->hmac);
2625 else if (GNUNET_MESSAGE_TYPE_CADET_AX == type)
2627 const struct GNUNET_CADET_AX *emsg;
2629 emsg = (struct GNUNET_CADET_AX *) msg;
2630 payload_size = size - sizeof (struct GNUNET_CADET_AX);
2631 decrypted_size = t_ax_decrypt_and_validate (t, cbuf, &emsg[1],
2632 payload_size, &emsg->hmac);
2635 if (-1 == decrypted_size)
2637 GNUNET_break_op (0);
2642 while (off < decrypted_size)
2646 msgh = (struct GNUNET_MessageHeader *) &cbuf[off];
2647 msize = ntohs (msgh->size);
2648 if (msize < sizeof (struct GNUNET_MessageHeader))
2650 GNUNET_break_op (0);
2653 handle_decrypted (t, msgh, GNUNET_SYSERR);
2660 * Demultiplex an encapsulated KX message by message type.
2662 * @param t Tunnel on which the message came.
2663 * @param message Payload of KX message.
2666 GCT_handle_kx (struct CadetTunnel *t,
2667 const struct GNUNET_MessageHeader *message)
2671 type = ntohs (message->type);
2672 LOG (GNUNET_ERROR_TYPE_DEBUG, "kx message received: %s\n", GC_m2s (type));
2675 case GNUNET_MESSAGE_TYPE_CADET_KX_EPHEMERAL:
2676 handle_ephemeral (t, (const struct GNUNET_CADET_KX_Ephemeral *) message);
2679 case GNUNET_MESSAGE_TYPE_CADET_KX_PONG:
2680 handle_pong (t, (const struct GNUNET_CADET_KX_Pong *) message);
2683 case GNUNET_MESSAGE_TYPE_CADET_AX_KX:
2684 handle_kx_ax (t, (const struct GNUNET_CADET_AX_KX *) message);
2688 GNUNET_break_op (0);
2689 LOG (GNUNET_ERROR_TYPE_WARNING, "kx message %s unknown\n", GC_m2s (type));
2694 * Initialize the tunnel subsystem.
2696 * @param c Configuration handle.
2697 * @param key ECC private key, to derive all other keys and do crypto.
2700 GCT_init (const struct GNUNET_CONFIGURATION_Handle *c,
2701 const struct GNUNET_CRYPTO_EddsaPrivateKey *key)
2703 int expected_overhead;
2705 LOG (GNUNET_ERROR_TYPE_DEBUG, "init\n");
2707 expected_overhead = 0;
2708 expected_overhead += sizeof (struct GNUNET_CADET_Encrypted);
2709 expected_overhead += sizeof (struct GNUNET_CADET_Data);
2710 expected_overhead += sizeof (struct GNUNET_CADET_ACK);
2711 GNUNET_assert (GNUNET_CONSTANTS_CADET_P2P_OVERHEAD == expected_overhead);
2714 GNUNET_CONFIGURATION_get_value_number (c, "CADET", "DEFAULT_TTL",
2717 GNUNET_log_config_invalid (GNUNET_ERROR_TYPE_WARNING,
2718 "CADET", "DEFAULT_TTL", "USING DEFAULT");
2722 GNUNET_CONFIGURATION_get_value_time (c, "CADET", "REKEY_PERIOD",
2725 rekey_period = GNUNET_TIME_UNIT_DAYS;
2730 otr_kx_msg.header.size = htons (sizeof (otr_kx_msg));
2731 otr_kx_msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_KX_EPHEMERAL);
2732 otr_kx_msg.purpose.purpose = htonl (GNUNET_SIGNATURE_PURPOSE_CADET_KX);
2733 otr_kx_msg.purpose.size = htonl (ephemeral_purpose_size ());
2734 otr_kx_msg.origin_identity = my_full_id;
2735 rekey_task = GNUNET_SCHEDULER_add_now (&global_otr_rekey, NULL);
2737 ax_key = GNUNET_CRYPTO_ecdhe_key_create ();
2738 GNUNET_CRYPTO_ecdhe_key_get_public (ax_key, &ax_identity.permanent_key);
2739 ax_identity.purpose.purpose = htonl (GNUNET_SIGNATURE_PURPOSE_CADET_AXKX);
2740 ax_identity.purpose.size = htonl (ax_purpose_size ());
2741 GNUNET_assert (GNUNET_OK ==
2742 GNUNET_CRYPTO_eddsa_sign (id_key,
2743 &ax_identity.purpose,
2744 &ax_identity.signature));
2746 tunnels = GNUNET_CONTAINER_multipeermap_create (128, GNUNET_YES);
2751 * Shut down the tunnel subsystem.
2756 if (NULL != rekey_task)
2758 GNUNET_SCHEDULER_cancel (rekey_task);
2761 GNUNET_CONTAINER_multipeermap_iterate (tunnels, &destroy_iterator, NULL);
2762 GNUNET_CONTAINER_multipeermap_destroy (tunnels);
2763 GNUNET_free (ax_key);
2770 * @param destination Peer this tunnel is towards.
2772 struct CadetTunnel *
2773 GCT_new (struct CadetPeer *destination)
2775 struct CadetTunnel *t;
2777 t = GNUNET_new (struct CadetTunnel);
2779 t->peer = destination;
2782 GNUNET_CONTAINER_multipeermap_put (tunnels, GCP_get_id (destination), t,
2783 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_FAST))
2789 t->ax = GNUNET_new (struct CadetTunnelAxolotl);
2791 t->ax->kx_0 = GNUNET_CRYPTO_ecdhe_key_create ();
2797 * Change the tunnel's connection state.
2799 * @param t Tunnel whose connection state to change.
2800 * @param cstate New connection state.
2803 GCT_change_cstate (struct CadetTunnel* t, enum CadetTunnelCState cstate)
2807 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel %s cstate %s => %s\n",
2808 GCP_2s (t->peer), cstate2s (t->cstate), cstate2s (cstate));
2809 if (myid != GCP_get_short_id (t->peer) &&
2810 CADET_TUNNEL_READY != t->cstate &&
2811 CADET_TUNNEL_READY == cstate)
2814 if (CADET_TUNNEL_KEY_OK == t->estate)
2816 LOG (GNUNET_ERROR_TYPE_DEBUG, " cstate triggered send queued data\n");
2817 send_queued_data (t);
2819 else if (CADET_TUNNEL_KEY_UNINITIALIZED == t->estate)
2821 LOG (GNUNET_ERROR_TYPE_DEBUG, " cstate triggered kx\n");
2826 LOG (GNUNET_ERROR_TYPE_DEBUG, "estate %s\n", estate2s (t->estate));
2831 if (CADET_TUNNEL_READY == cstate
2832 && CONNECTIONS_PER_TUNNEL <= GCT_count_connections (t))
2834 LOG (GNUNET_ERROR_TYPE_DEBUG, " cstate triggered stop dht\n");
2835 GCP_stop_search (t->peer);
2841 * Change the tunnel encryption state.
2843 * @param t Tunnel whose encryption state to change, or NULL.
2844 * @param state New encryption state.
2847 GCT_change_estate (struct CadetTunnel* t, enum CadetTunnelEState state)
2849 enum CadetTunnelEState old;
2856 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel %s estate was %s\n",
2857 GCP_2s (t->peer), estate2s (old));
2858 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel %s estate is now %s\n",
2859 GCP_2s (t->peer), estate2s (t->estate));
2861 /* Send queued data if enc state changes to OK */
2862 if (myid != GCP_get_short_id (t->peer) &&
2863 CADET_TUNNEL_KEY_OK != old && CADET_TUNNEL_KEY_OK == t->estate)
2865 send_queued_data (t);
2871 * @brief Check if tunnel has too many connections, and remove one if necessary.
2873 * Currently this means the newest connection, unless it is a direct one.
2874 * Implemented as a task to avoid freeing a connection that is in the middle
2875 * of being created/processed.
2877 * @param cls Closure (Tunnel to check).
2878 * @param tc Task context.
2881 trim_connections (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
2883 struct CadetTunnel *t = cls;
2885 t->trim_connections_task = NULL;
2887 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
2890 if (GCT_count_connections (t) > 2 * CONNECTIONS_PER_TUNNEL)
2892 struct CadetTConnection *iter;
2893 struct CadetTConnection *c;
2895 for (c = iter = t->connection_head; NULL != iter; iter = iter->next)
2897 if ((iter->created.abs_value_us > c->created.abs_value_us)
2898 && GNUNET_NO == GCC_is_direct (iter->c))
2905 LOG (GNUNET_ERROR_TYPE_DEBUG, "Too many connections on tunnel %s\n",
2907 LOG (GNUNET_ERROR_TYPE_DEBUG, "Destroying connection %s\n",
2920 * Add a connection to a tunnel.
2923 * @param c Connection.
2926 GCT_add_connection (struct CadetTunnel *t, struct CadetConnection *c)
2928 struct CadetTConnection *aux;
2930 GNUNET_assert (NULL != c);
2932 LOG (GNUNET_ERROR_TYPE_DEBUG, "add connection %s\n", GCC_2s (c));
2933 LOG (GNUNET_ERROR_TYPE_DEBUG, " to tunnel %s\n", GCT_2s (t));
2934 for (aux = t->connection_head; aux != NULL; aux = aux->next)
2938 aux = GNUNET_new (struct CadetTConnection);
2940 aux->created = GNUNET_TIME_absolute_get ();
2942 GNUNET_CONTAINER_DLL_insert (t->connection_head, t->connection_tail, aux);
2944 if (CADET_TUNNEL_SEARCHING == t->cstate)
2945 GCT_change_cstate (t, CADET_TUNNEL_WAITING);
2947 if (NULL != t->trim_connections_task)
2948 t->trim_connections_task = GNUNET_SCHEDULER_add_now (&trim_connections, t);
2953 * Remove a connection from a tunnel.
2956 * @param c Connection.
2959 GCT_remove_connection (struct CadetTunnel *t,
2960 struct CadetConnection *c)
2962 struct CadetTConnection *aux;
2963 struct CadetTConnection *next;
2966 LOG (GNUNET_ERROR_TYPE_DEBUG, "Removing connection %s from tunnel %s\n",
2967 GCC_2s (c), GCT_2s (t));
2968 for (aux = t->connection_head; aux != NULL; aux = next)
2973 GNUNET_CONTAINER_DLL_remove (t->connection_head, t->connection_tail, aux);
2978 conns = GCT_count_connections (t);
2980 && NULL == t->destroy_task
2981 && CADET_TUNNEL_SHUTDOWN != t->cstate
2982 && GNUNET_NO == shutting_down)
2984 if (0 == GCT_count_any_connections (t))
2985 GCT_change_cstate (t, CADET_TUNNEL_SEARCHING);
2987 GCT_change_cstate (t, CADET_TUNNEL_WAITING);
2990 /* Start new connections if needed */
2991 if (CONNECTIONS_PER_TUNNEL > conns
2992 && NULL == t->destroy_task
2993 && CADET_TUNNEL_SHUTDOWN != t->cstate
2994 && GNUNET_NO == shutting_down)
2996 LOG (GNUNET_ERROR_TYPE_DEBUG, " too few connections, getting new ones\n");
2997 GCP_connect (t->peer); /* Will change cstate to WAITING when possible */
3001 /* If not marked as ready, no change is needed */
3002 if (CADET_TUNNEL_READY != t->cstate)
3005 /* Check if any connection is ready to maintain cstate */
3006 for (aux = t->connection_head; aux != NULL; aux = aux->next)
3007 if (CADET_CONNECTION_READY == GCC_get_state (aux->c))
3013 * Add a channel to a tunnel.
3016 * @param ch Channel.
3019 GCT_add_channel (struct CadetTunnel *t, struct CadetChannel *ch)
3021 struct CadetTChannel *aux;
3023 GNUNET_assert (NULL != ch);
3025 LOG (GNUNET_ERROR_TYPE_DEBUG, "Adding channel %p to tunnel %p\n", ch, t);
3027 for (aux = t->channel_head; aux != NULL; aux = aux->next)
3029 LOG (GNUNET_ERROR_TYPE_DEBUG, " already there %p\n", aux->ch);
3034 aux = GNUNET_new (struct CadetTChannel);
3036 LOG (GNUNET_ERROR_TYPE_DEBUG, " adding %p to %p\n", aux, t->channel_head);
3037 GNUNET_CONTAINER_DLL_insert_tail (t->channel_head, t->channel_tail, aux);
3039 if (NULL != t->destroy_task)
3041 GNUNET_SCHEDULER_cancel (t->destroy_task);
3042 t->destroy_task = NULL;
3043 LOG (GNUNET_ERROR_TYPE_DEBUG, " undo destroy!\n");
3049 * Remove a channel from a tunnel.
3052 * @param ch Channel.
3055 GCT_remove_channel (struct CadetTunnel *t, struct CadetChannel *ch)
3057 struct CadetTChannel *aux;
3059 LOG (GNUNET_ERROR_TYPE_DEBUG, "Removing channel %p from tunnel %p\n", ch, t);
3060 for (aux = t->channel_head; aux != NULL; aux = aux->next)
3064 LOG (GNUNET_ERROR_TYPE_DEBUG, " found! %s\n", GCCH_2s (ch));
3065 GNUNET_CONTAINER_DLL_remove (t->channel_head, t->channel_tail, aux);
3074 * Search for a channel by global ID.
3076 * @param t Tunnel containing the channel.
3077 * @param chid Public channel number.
3079 * @return channel handler, NULL if doesn't exist
3081 struct CadetChannel *
3082 GCT_get_channel (struct CadetTunnel *t, CADET_ChannelNumber chid)
3084 struct CadetTChannel *iter;
3089 for (iter = t->channel_head; NULL != iter; iter = iter->next)
3091 if (GCCH_get_id (iter->ch) == chid)
3095 return NULL == iter ? NULL : iter->ch;
3100 * @brief Destroy a tunnel and free all resources.
3102 * Should only be called a while after the tunnel has been marked as destroyed,
3103 * in case there is a new channel added to the same peer shortly after marking
3104 * the tunnel. This way we avoid a new public key handshake.
3106 * @param cls Closure (tunnel to destroy).
3107 * @param tc Task context.
3110 delayed_destroy (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
3112 struct CadetTunnel *t = cls;
3113 struct CadetTConnection *iter;
3115 LOG (GNUNET_ERROR_TYPE_DEBUG, "delayed destroying tunnel %p\n", t);
3116 if (0 != (GNUNET_SCHEDULER_REASON_SHUTDOWN & tc->reason))
3118 LOG (GNUNET_ERROR_TYPE_WARNING,
3119 "Not destroying tunnel, due to shutdown. "
3120 "Tunnel at %p should have been freed by GCT_shutdown\n", t);
3123 t->destroy_task = NULL;
3124 t->cstate = CADET_TUNNEL_SHUTDOWN;
3126 for (iter = t->connection_head; NULL != iter; iter = iter->next)
3128 GCC_send_destroy (iter->c);
3135 * Tunnel is empty: destroy it.
3137 * Notifies all connections about the destruction.
3139 * @param t Tunnel to destroy.
3142 GCT_destroy_empty (struct CadetTunnel *t)
3144 if (GNUNET_YES == shutting_down)
3145 return; /* Will be destroyed immediately anyway */
3147 if (NULL != t->destroy_task)
3149 LOG (GNUNET_ERROR_TYPE_WARNING,
3150 "Tunnel %s is already scheduled for destruction. Tunnel debug dump:\n",
3152 GCT_debug (t, GNUNET_ERROR_TYPE_WARNING);
3154 /* should never happen, tunnel can only become empty once, and the
3155 * task identifier should be NO_TASK (cleaned when the tunnel was created
3156 * or became un-empty)
3161 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel %s empty: scheduling destruction\n",
3164 // FIXME make delay a config option
3165 t->destroy_task = GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_MINUTES,
3166 &delayed_destroy, t);
3167 LOG (GNUNET_ERROR_TYPE_DEBUG, "Scheduled destroy of %p as %llu\n",
3168 t, t->destroy_task);
3173 * Destroy tunnel if empty (no more channels).
3175 * @param t Tunnel to destroy if empty.
3178 GCT_destroy_if_empty (struct CadetTunnel *t)
3180 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel %s destroy if empty\n", GCT_2s (t));
3181 if (0 < GCT_count_channels (t))
3184 GCT_destroy_empty (t);
3189 * Destroy the tunnel.
3191 * This function does not generate any warning traffic to clients or peers.
3194 * Cancel messages belonging to this tunnel queued to neighbors.
3195 * Free any allocated resources linked to the tunnel.
3197 * @param t The tunnel to destroy.
3200 GCT_destroy (struct CadetTunnel *t)
3202 struct CadetTConnection *iter_c;
3203 struct CadetTConnection *next_c;
3204 struct CadetTChannel *iter_ch;
3205 struct CadetTChannel *next_ch;
3210 LOG (GNUNET_ERROR_TYPE_DEBUG, "destroying tunnel %s\n", GCP_2s (t->peer));
3212 GNUNET_break (GNUNET_YES ==
3213 GNUNET_CONTAINER_multipeermap_remove (tunnels,
3214 GCP_get_id (t->peer), t));
3216 for (iter_c = t->connection_head; NULL != iter_c; iter_c = next_c)
3218 next_c = iter_c->next;
3219 GCC_destroy (iter_c->c);
3221 for (iter_ch = t->channel_head; NULL != iter_ch; iter_ch = next_ch)
3223 next_ch = iter_ch->next;
3224 GCCH_destroy (iter_ch->ch);
3225 /* Should only happen on shutdown, but it's ok. */
3228 if (NULL != t->destroy_task)
3230 LOG (GNUNET_ERROR_TYPE_DEBUG, "cancelling dest: %llX\n", t->destroy_task);
3231 GNUNET_SCHEDULER_cancel (t->destroy_task);
3232 t->destroy_task = NULL;
3235 if (NULL != t->trim_connections_task)
3237 LOG (GNUNET_ERROR_TYPE_DEBUG, "cancelling trim: %llX\n",
3238 t->trim_connections_task);
3239 GNUNET_SCHEDULER_cancel (t->trim_connections_task);
3240 t->trim_connections_task = NULL;
3243 GNUNET_STATISTICS_update (stats, "# tunnels", -1, GNUNET_NO);
3244 GCP_set_tunnel (t->peer, NULL);
3246 if (NULL != t->rekey_task)
3248 GNUNET_SCHEDULER_cancel (t->rekey_task);
3249 t->rekey_task = NULL;
3251 if (NULL != t->kx_ctx)
3253 if (NULL != t->kx_ctx->finish_task)
3254 GNUNET_SCHEDULER_cancel (t->kx_ctx->finish_task);
3255 GNUNET_free (t->kx_ctx);
3266 * @brief Use the given path for the tunnel.
3267 * Update the next and prev hops (and RCs).
3268 * (Re)start the path refresh in case the tunnel is locally owned.
3270 * @param t Tunnel to update.
3271 * @param p Path to use.
3273 * @return Connection created.
3275 struct CadetConnection *
3276 GCT_use_path (struct CadetTunnel *t, struct CadetPeerPath *p)
3278 struct CadetConnection *c;
3279 struct GNUNET_CADET_Hash cid;
3280 unsigned int own_pos;
3282 if (NULL == t || NULL == p)
3288 if (CADET_TUNNEL_SHUTDOWN == t->cstate)
3294 for (own_pos = 0; own_pos < p->length; own_pos++)
3296 if (p->peers[own_pos] == myid)
3299 if (own_pos >= p->length)
3301 GNUNET_break_op (0);
3305 GNUNET_CRYPTO_random_block (GNUNET_CRYPTO_QUALITY_NONCE, &cid, sizeof (cid));
3306 c = GCC_new (&cid, t, p, own_pos);
3309 /* Path was flawed */
3312 GCT_add_connection (t, c);
3318 * Count all created connections of a tunnel. Not necessarily ready connections!
3320 * @param t Tunnel on which to count.
3322 * @return Number of connections created, either being established or ready.
3325 GCT_count_any_connections (struct CadetTunnel *t)
3327 struct CadetTConnection *iter;
3333 for (count = 0, iter = t->connection_head; NULL != iter; iter = iter->next)
3341 * Count established (ready) connections of a tunnel.
3343 * @param t Tunnel on which to count.
3345 * @return Number of connections.
3348 GCT_count_connections (struct CadetTunnel *t)
3350 struct CadetTConnection *iter;
3356 for (count = 0, iter = t->connection_head; NULL != iter; iter = iter->next)
3357 if (CADET_CONNECTION_READY == GCC_get_state (iter->c))
3365 * Count channels of a tunnel.
3367 * @param t Tunnel on which to count.
3369 * @return Number of channels.
3372 GCT_count_channels (struct CadetTunnel *t)
3374 struct CadetTChannel *iter;
3377 for (count = 0, iter = t->channel_head;
3379 iter = iter->next, count++) /* skip */;
3386 * Get the connectivity state of a tunnel.
3390 * @return Tunnel's connectivity state.
3392 enum CadetTunnelCState
3393 GCT_get_cstate (struct CadetTunnel *t)
3398 return (enum CadetTunnelCState) -1;
3405 * Get the encryption state of a tunnel.
3409 * @return Tunnel's encryption state.
3411 enum CadetTunnelEState
3412 GCT_get_estate (struct CadetTunnel *t)
3417 return (enum CadetTunnelEState) -1;
3423 * Get the maximum buffer space for a tunnel towards a local client.
3427 * @return Biggest buffer space offered by any channel in the tunnel.
3430 GCT_get_channels_buffer (struct CadetTunnel *t)
3432 struct CadetTChannel *iter;
3433 unsigned int buffer;
3434 unsigned int ch_buf;
3436 if (NULL == t->channel_head)
3438 /* Probably getting buffer for a channel create/handshake. */
3439 LOG (GNUNET_ERROR_TYPE_DEBUG, " no channels, allow max\n");
3444 for (iter = t->channel_head; NULL != iter; iter = iter->next)
3446 ch_buf = get_channel_buffer (iter);
3447 if (ch_buf > buffer)
3455 * Get the total buffer space for a tunnel for P2P traffic.
3459 * @return Buffer space offered by all connections in the tunnel.
3462 GCT_get_connections_buffer (struct CadetTunnel *t)
3464 struct CadetTConnection *iter;
3465 unsigned int buffer;
3467 if (GNUNET_NO == is_ready (t))
3469 if (count_queued_data (t) > 3)
3476 for (iter = t->connection_head; NULL != iter; iter = iter->next)
3478 if (GCC_get_state (iter->c) != CADET_CONNECTION_READY)
3482 buffer += get_connection_buffer (iter);
3490 * Get the tunnel's destination.
3494 * @return ID of the destination peer.
3496 const struct GNUNET_PeerIdentity *
3497 GCT_get_destination (struct CadetTunnel *t)
3499 return GCP_get_id (t->peer);
3504 * Get the tunnel's next free global channel ID.
3508 * @return GID of a channel free to use.
3511 GCT_get_next_chid (struct CadetTunnel *t)
3513 CADET_ChannelNumber chid;
3514 CADET_ChannelNumber mask;
3517 /* Set bit 30 depending on the ID relationship. Bit 31 is always 0 for GID.
3518 * If our ID is bigger or loopback tunnel, start at 0, bit 30 = 0
3519 * If peer's ID is bigger, start at 0x4... bit 30 = 1
3521 result = GNUNET_CRYPTO_cmp_peer_identity (&my_full_id, GCP_get_id (t->peer));
3526 t->next_chid |= mask;
3528 while (NULL != GCT_get_channel (t, t->next_chid))
3530 LOG (GNUNET_ERROR_TYPE_DEBUG, "Channel %u exists...\n", t->next_chid);
3531 t->next_chid = (t->next_chid + 1) & ~GNUNET_CADET_LOCAL_CHANNEL_ID_CLI;
3532 t->next_chid |= mask;
3534 chid = t->next_chid;
3535 t->next_chid = (t->next_chid + 1) & ~GNUNET_CADET_LOCAL_CHANNEL_ID_CLI;
3536 t->next_chid |= mask;
3543 * Send ACK on one or more channels due to buffer in connections.
3545 * @param t Channel which has some free buffer space.
3548 GCT_unchoke_channels (struct CadetTunnel *t)
3550 struct CadetTChannel *iter;
3551 unsigned int buffer;
3552 unsigned int channels = GCT_count_channels (t);
3553 unsigned int choked_n;
3554 struct CadetChannel *choked[channels];
3556 LOG (GNUNET_ERROR_TYPE_DEBUG, "GCT_unchoke_channels on %s\n", GCT_2s (t));
3557 LOG (GNUNET_ERROR_TYPE_DEBUG, " head: %p\n", t->channel_head);
3558 if (NULL != t->channel_head)
3559 LOG (GNUNET_ERROR_TYPE_DEBUG, " head ch: %p\n", t->channel_head->ch);
3561 /* Get buffer space */
3562 buffer = GCT_get_connections_buffer (t);
3568 /* Count and remember choked channels */
3570 for (iter = t->channel_head; NULL != iter; iter = iter->next)
3572 if (GNUNET_NO == get_channel_allowed (iter))
3574 choked[choked_n++] = iter->ch;
3578 /* Unchoke random channels */
3579 while (0 < buffer && 0 < choked_n)
3581 unsigned int r = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK,
3583 GCCH_allow_client (choked[r], GCCH_is_origin (choked[r], GNUNET_YES));
3586 choked[r] = choked[choked_n];
3592 * Send ACK on one or more connections due to buffer space to the client.
3594 * Iterates all connections of the tunnel and sends ACKs appropriately.
3599 GCT_send_connection_acks (struct CadetTunnel *t)
3601 struct CadetTConnection *iter;
3604 uint32_t allow_per_connection;
3606 unsigned int buffer;
3608 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel send connection ACKs on %s\n",
3617 if (CADET_TUNNEL_READY != t->cstate)
3620 buffer = GCT_get_channels_buffer (t);
3621 LOG (GNUNET_ERROR_TYPE_DEBUG, " buffer %u\n", buffer);
3623 /* Count connections, how many messages are already allowed */
3624 cs = GCT_count_connections (t);
3625 for (allowed = 0, iter = t->connection_head; NULL != iter; iter = iter->next)
3627 allowed += get_connection_allowed (iter);
3629 LOG (GNUNET_ERROR_TYPE_DEBUG, " allowed %u\n", allowed);
3631 /* Make sure there is no overflow */
3632 if (allowed > buffer)
3635 /* Authorize connections to send more data */
3636 to_allow = buffer - allowed;
3638 for (iter = t->connection_head;
3639 NULL != iter && to_allow > 0;
3642 if (CADET_CONNECTION_READY != GCC_get_state (iter->c)
3643 || get_connection_allowed (iter) > 64 / 3)
3647 allow_per_connection = to_allow/cs;
3648 to_allow -= allow_per_connection;
3650 GCC_allow (iter->c, allow_per_connection,
3651 GCC_is_origin (iter->c, GNUNET_NO));
3656 /* Since we don't allow if it's allowed to send 64/3, this can happen. */
3657 LOG (GNUNET_ERROR_TYPE_DEBUG, " reminding to_allow: %u\n", to_allow);
3663 * Cancel a previously sent message while it's in the queue.
3665 * ONLY can be called before the continuation given to the send function
3666 * is called. Once the continuation is called, the message is no longer in the
3669 * @param q Handle to the queue.
3672 GCT_cancel (struct CadetTunnelQueue *q)
3677 /* tun_message_sent() will be called and free q */
3679 else if (NULL != q->tqd)
3681 unqueue_data (q->tqd);
3683 if (NULL != q->cont)
3684 q->cont (q->cont_cls, NULL, q, 0, 0);
3695 * Sends an already built message on a tunnel, encrypting it and
3696 * choosing the best connection if not provided.
3698 * @param message Message to send. Function modifies it.
3699 * @param t Tunnel on which this message is transmitted.
3700 * @param c Connection to use (autoselect if NULL).
3701 * @param force Force the tunnel to take the message (buffer overfill).
3702 * @param cont Continuation to call once message is really sent.
3703 * @param cont_cls Closure for @c cont.
3705 * @return Handle to cancel message. NULL if @c cont is NULL.
3707 struct CadetTunnelQueue *
3708 GCT_send_prebuilt_message (const struct GNUNET_MessageHeader *message,
3709 struct CadetTunnel *t, struct CadetConnection *c,
3710 int force, GCT_sent cont, void *cont_cls)
3712 return send_prebuilt_message (message, t, c, force, cont, cont_cls, NULL);
3717 * Send an Axolotl KX message.
3719 * @param t Tunnel on which to send it.
3722 GCT_send_ax_kx (struct CadetTunnel *t)
3724 struct GNUNET_CADET_AX_KX msg;
3726 LOG (GNUNET_ERROR_TYPE_INFO, "===> AX_KX for %s\n", GCT_2s (t));
3728 msg.header.size = htons (sizeof (msg));
3729 msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_AX_KX);
3730 msg.permanent_key = ax_identity.permanent_key;
3731 msg.purpose = ax_identity.purpose;
3732 msg.signature = ax_identity.signature;
3733 GNUNET_CRYPTO_ecdhe_key_get_public (t->ax->kx_0, &msg.ephemeral_key);
3734 GNUNET_CRYPTO_ecdhe_key_get_public (t->ax->DHRs, &msg.ratchet_key);
3736 t->ephm_h = send_kx (t, &msg.header);
3737 GCT_change_estate (t, CADET_TUNNEL_KEY_SENT);
3742 * Sends an already built and encrypted message on a tunnel, choosing the best
3743 * connection. Useful for re-queueing messages queued on a destroyed connection.
3745 * @param message Message to send. Function modifies it.
3746 * @param t Tunnel on which this message is transmitted.
3749 GCT_resend_message (const struct GNUNET_MessageHeader *message,
3750 struct CadetTunnel *t)
3752 struct CadetConnection *c;
3755 c = tunnel_get_connection (t);
3758 /* TODO queue in tunnel, marked as encrypted */
3759 LOG (GNUNET_ERROR_TYPE_DEBUG, "No connection available, dropping.\n");
3762 fwd = GCC_is_origin (c, GNUNET_YES);
3763 GNUNET_break (NULL == GCC_send_prebuilt_message (message, 0, 0, c, fwd,
3764 GNUNET_YES, NULL, NULL));
3769 * Is the tunnel directed towards the local peer?
3773 * @return #GNUNET_YES if it is loopback.
3776 GCT_is_loopback (const struct CadetTunnel *t)
3778 return (myid == GCP_get_short_id (t->peer));
3783 * Is the tunnel this path already?
3788 * @return #GNUNET_YES a connection uses this path.
3791 GCT_is_path_used (const struct CadetTunnel *t, const struct CadetPeerPath *p)
3793 struct CadetTConnection *iter;
3795 for (iter = t->connection_head; NULL != iter; iter = iter->next)
3796 if (path_equivalent (GCC_get_path (iter->c), p))
3804 * Get a cost of a path for a tunnel considering existing connections.
3807 * @param path Candidate path.
3809 * @return Cost of the path (path length + number of overlapping nodes)
3812 GCT_get_path_cost (const struct CadetTunnel *t,
3813 const struct CadetPeerPath *path)
3815 struct CadetTConnection *iter;
3816 const struct CadetPeerPath *aux;
3817 unsigned int overlap;
3825 GNUNET_assert (NULL != t);
3827 for (i = 0; i < path->length; i++)
3829 for (iter = t->connection_head; NULL != iter; iter = iter->next)
3831 aux = GCC_get_path (iter->c);
3835 for (j = 0; j < aux->length; j++)
3837 if (path->peers[i] == aux->peers[j])
3845 return path->length + overlap;
3850 * Get the static string for the peer this tunnel is directed.
3854 * @return Static string the destination peer's ID.
3857 GCT_2s (const struct CadetTunnel *t)
3862 return GCP_2s (t->peer);
3866 /******************************************************************************/
3867 /***************************** INFO/DEBUG *******************************/
3868 /******************************************************************************/
3871 * Log all possible info about the tunnel state.
3873 * @param t Tunnel to debug.
3874 * @param level Debug level to use.
3877 GCT_debug (const struct CadetTunnel *t, enum GNUNET_ErrorType level)
3879 struct CadetTChannel *iterch;
3880 struct CadetTConnection *iterc;
3883 do_log = GNUNET_get_log_call_status (level & (~GNUNET_ERROR_TYPE_BULK),
3885 __FILE__, __FUNCTION__, __LINE__);
3889 LOG2 (level, "TTT DEBUG TUNNEL TOWARDS %s\n", GCT_2s (t));
3890 LOG2 (level, "TTT cstate %s, estate %s\n",
3891 cstate2s (t->cstate), estate2s (t->estate));
3892 LOG2 (level, "TTT kx_ctx %p, rekey_task %u, finish task %u\n",
3893 t->kx_ctx, t->rekey_task, t->kx_ctx ? t->kx_ctx->finish_task : 0);
3894 #if DUMP_KEYS_TO_STDERR
3895 LOG2 (level, "TTT my EPHM\t %s\n",
3896 GNUNET_h2s ((struct GNUNET_HashCode *) &otr_kx_msg.ephemeral_key));
3897 LOG2 (level, "TTT peers EPHM:\t %s\n",
3898 GNUNET_h2s ((struct GNUNET_HashCode *) &t->peers_ephemeral_key));
3899 LOG2 (level, "TTT ENC key:\t %s\n",
3900 GNUNET_h2s ((struct GNUNET_HashCode *) &t->e_key));
3901 LOG2 (level, "TTT DEC key:\t %s\n",
3902 GNUNET_h2s ((struct GNUNET_HashCode *) &t->d_key));
3905 LOG2 (level, "TTT OLD ENC key:\t %s\n",
3906 GNUNET_h2s ((struct GNUNET_HashCode *) &t->kx_ctx->e_key_old));
3907 LOG2 (level, "TTT OLD DEC key:\t %s\n",
3908 GNUNET_h2s ((struct GNUNET_HashCode *) &t->kx_ctx->d_key_old));
3911 LOG2 (level, "TTT tq_head %p, tq_tail %p\n", t->tq_head, t->tq_tail);
3912 LOG2 (level, "TTT destroy %u\n", t->destroy_task);
3914 LOG2 (level, "TTT channels:\n");
3915 for (iterch = t->channel_head; NULL != iterch; iterch = iterch->next)
3917 LOG2 (level, "TTT - %s\n", GCCH_2s (iterch->ch));
3920 LOG2 (level, "TTT connections:\n");
3921 for (iterc = t->connection_head; NULL != iterc; iterc = iterc->next)
3923 GCC_debug (iterc->c, level);
3926 LOG2 (level, "TTT DEBUG TUNNEL END\n");
3931 * Iterate all tunnels.
3933 * @param iter Iterator.
3934 * @param cls Closure for @c iter.
3937 GCT_iterate_all (GNUNET_CONTAINER_PeerMapIterator iter, void *cls)
3939 GNUNET_CONTAINER_multipeermap_iterate (tunnels, iter, cls);
3944 * Count all tunnels.
3946 * @return Number of tunnels to remote peers kept by this peer.
3949 GCT_count_all (void)
3951 return GNUNET_CONTAINER_multipeermap_size (tunnels);
3956 * Iterate all connections of a tunnel.
3958 * @param t Tunnel whose connections to iterate.
3959 * @param iter Iterator.
3960 * @param cls Closure for @c iter.
3963 GCT_iterate_connections (struct CadetTunnel *t, GCT_conn_iter iter, void *cls)
3965 struct CadetTConnection *ct;
3967 for (ct = t->connection_head; NULL != ct; ct = ct->next)
3973 * Iterate all channels of a tunnel.
3975 * @param t Tunnel whose channels to iterate.
3976 * @param iter Iterator.
3977 * @param cls Closure for @c iter.
3980 GCT_iterate_channels (struct CadetTunnel *t, GCT_chan_iter iter, void *cls)
3982 struct CadetTChannel *cht;
3984 for (cht = t->channel_head; NULL != cht; cht = cht->next)
3985 iter (cls, cht->ch);