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 for key exchange (A0 / B0)
225 struct GNUNET_CRYPTO_EcdhePrivateKey *kx_0;
228 * ECDH Ratchet key (send)
230 struct GNUNET_CRYPTO_EcdhePrivateKey *DHRs;
233 * ECDH Ratchet key (recv)
235 struct GNUNET_CRYPTO_EcdhePublicKey DHRr;
238 * Message number (reset to 0 with each new ratchet, send)
243 * Message numbers (reset to 0 with each new ratchet, recv)
248 * Previous message numbers (# of msgs sent under prev ratchet)
253 * True (#GNUNET_YES) if the party will send a new ratchet key in next msg.
259 * Struct containing all information regarding a tunnel to a peer.
264 * Endpoint of the tunnel.
266 struct CadetPeer *peer;
269 * Type of encryption used in the tunnel.
271 enum CadetTunnelEncryption enc_type;
276 struct CadetTunnelAxolotl *ax;
279 * State of the tunnel connectivity.
281 enum CadetTunnelCState cstate;
284 * State of the tunnel encryption.
286 enum CadetTunnelEState estate;
289 * Key eXchange context.
291 struct CadetTunnelKXCtx *kx_ctx;
294 * Peer's ephemeral key, to recreate @c e_key and @c d_key when own ephemeral
297 struct GNUNET_CRYPTO_EcdhePublicKey peers_ephemeral_key;
300 * Encryption ("our") key. It is only "confirmed" if kx_ctx is NULL.
302 struct GNUNET_CRYPTO_SymmetricSessionKey e_key;
305 * Decryption ("their") key. It is only "confirmed" if kx_ctx is NULL.
307 struct GNUNET_CRYPTO_SymmetricSessionKey d_key;
310 * Task to start the rekey process.
312 struct GNUNET_SCHEDULER_Task * rekey_task;
315 * Paths that are actively used to reach the destination peer.
317 struct CadetTConnection *connection_head;
318 struct CadetTConnection *connection_tail;
321 * Next connection number.
326 * Channels inside this tunnel.
328 struct CadetTChannel *channel_head;
329 struct CadetTChannel *channel_tail;
332 * Channel ID for the next created channel.
334 CADET_ChannelNumber next_chid;
337 * Destroy flag: if true, destroy on last message.
339 struct GNUNET_SCHEDULER_Task * destroy_task;
342 * Queued messages, to transmit once tunnel gets connected.
344 struct CadetTunnelDelayed *tq_head;
345 struct CadetTunnelDelayed *tq_tail;
348 * Task to trim connections if too many are present.
350 struct GNUNET_SCHEDULER_Task * trim_connections_task;
353 * Ephemeral message in the queue (to avoid queueing more than one).
355 struct CadetConnectionQueue *ephm_h;
358 * Pong message in the queue.
360 struct CadetConnectionQueue *pong_h;
365 * Struct used to save messages in a non-ready tunnel to send once connected.
367 struct CadetTunnelDelayed
372 struct CadetTunnelDelayed *next;
373 struct CadetTunnelDelayed *prev;
378 struct CadetTunnel *t;
381 * Tunnel queue given to the channel to cancel request. Update on send_queued.
383 struct CadetTunnelQueue *tq;
388 /* struct GNUNET_MessageHeader *msg; */
393 * Handle for messages queued but not yet sent.
395 struct CadetTunnelQueue
398 * Connection queue handle, to cancel if necessary.
400 struct CadetConnectionQueue *cq;
403 * Handle in case message hasn't been given to a connection yet.
405 struct CadetTunnelDelayed *tqd;
408 * Continuation to call once sent.
413 * Closure for @c cont.
419 /******************************************************************************/
420 /******************************* GLOBALS ***********************************/
421 /******************************************************************************/
424 * Global handle to the statistics service.
426 extern struct GNUNET_STATISTICS_Handle *stats;
429 * Local peer own ID (memory efficient handle).
431 extern GNUNET_PEER_Id myid;
434 * Local peer own ID (full value).
436 extern struct GNUNET_PeerIdentity my_full_id;
440 * Don't try to recover tunnels if shutting down.
442 extern int shutting_down;
446 * Set of all tunnels, in order to trigger a new exchange on rekey.
447 * Indexed by peer's ID.
449 static struct GNUNET_CONTAINER_MultiPeerMap *tunnels;
452 * Default TTL for payload packets.
454 static unsigned long long default_ttl;
459 const static struct GNUNET_CRYPTO_EddsaPrivateKey *my_private_key;
462 * Own Axolotl private key (derived from @a my_private_key).
464 const struct GNUNET_CRYPTO_EcdhePrivateKey *ax_identity;
467 * Own OTR ephemeral private key.
469 static struct GNUNET_CRYPTO_EcdhePrivateKey *my_ephemeral_key;
472 * Cached message used to perform a key exchange.
474 static struct GNUNET_CADET_KX_Ephemeral kx_msg;
477 * Task to generate a new ephemeral key.
479 static struct GNUNET_SCHEDULER_Task * rekey_task;
484 static struct GNUNET_TIME_Relative rekey_period;
487 /******************************************************************************/
488 /******************************** STATIC ***********************************/
489 /******************************************************************************/
492 * Get string description for tunnel connectivity state.
494 * @param cs Tunnel state.
496 * @return String representation.
499 cstate2s (enum CadetTunnelCState cs)
505 case CADET_TUNNEL_NEW:
506 return "CADET_TUNNEL_NEW";
507 case CADET_TUNNEL_SEARCHING:
508 return "CADET_TUNNEL_SEARCHING";
509 case CADET_TUNNEL_WAITING:
510 return "CADET_TUNNEL_WAITING";
511 case CADET_TUNNEL_READY:
512 return "CADET_TUNNEL_READY";
513 case CADET_TUNNEL_SHUTDOWN:
514 return "CADET_TUNNEL_SHUTDOWN";
516 SPRINTF (buf, "%u (UNKNOWN STATE)", cs);
524 * Get string description for tunnel encryption state.
526 * @param es Tunnel state.
528 * @return String representation.
531 estate2s (enum CadetTunnelEState es)
537 case CADET_TUNNEL_KEY_UNINITIALIZED:
538 return "CADET_TUNNEL_KEY_UNINITIALIZED";
539 case CADET_TUNNEL_KEY_SENT:
540 return "CADET_TUNNEL_KEY_SENT";
541 case CADET_TUNNEL_KEY_PING:
542 return "CADET_TUNNEL_KEY_PING";
543 case CADET_TUNNEL_KEY_OK:
544 return "CADET_TUNNEL_KEY_OK";
545 case CADET_TUNNEL_KEY_REKEY:
546 return "CADET_TUNNEL_KEY_REKEY";
548 SPRINTF (buf, "%u (UNKNOWN STATE)", es);
556 * @brief Check if tunnel is ready to send traffic.
558 * Tunnel must be connected and with encryption correctly set up.
560 * @param t Tunnel to check.
562 * @return #GNUNET_YES if ready, #GNUNET_NO otherwise
565 is_ready (struct CadetTunnel *t)
569 GCT_debug (t, GNUNET_ERROR_TYPE_DEBUG);
570 ready = CADET_TUNNEL_READY == t->cstate
571 && (CADET_TUNNEL_KEY_OK == t->estate
572 || CADET_TUNNEL_KEY_REKEY == t->estate);
573 ready = ready || GCT_is_loopback (t);
579 * Check if a key is invalid (NULL pointer or all 0)
581 * @param key Key to check.
583 * @return #GNUNET_YES if key is null, #GNUNET_NO if exists and is not 0.
586 is_key_null (struct GNUNET_CRYPTO_SymmetricSessionKey *key)
588 struct GNUNET_CRYPTO_SymmetricSessionKey null_key;
593 memset (&null_key, 0, sizeof (null_key));
594 if (0 == memcmp (key, &null_key, sizeof (null_key)))
601 * Ephemeral key message purpose size.
603 * @return Size of the part of the ephemeral key message that must be signed.
606 ephemeral_purpose_size (void)
608 return sizeof (struct GNUNET_CRYPTO_EccSignaturePurpose) +
609 sizeof (struct GNUNET_TIME_AbsoluteNBO) +
610 sizeof (struct GNUNET_TIME_AbsoluteNBO) +
611 sizeof (struct GNUNET_CRYPTO_EcdhePublicKey) +
612 sizeof (struct GNUNET_PeerIdentity);
617 * Size of the encrypted part of a ping message.
619 * @return Size of the encrypted part of a ping message.
622 ping_encryption_size (void)
624 return sizeof (uint32_t);
629 * Get the channel's buffer. ONLY FOR NON-LOOPBACK CHANNELS!!
631 * @param tch Tunnel's channel handle.
633 * @return Amount of messages the channel can still buffer towards the client.
636 get_channel_buffer (const struct CadetTChannel *tch)
640 /* If channel is incoming, is terminal in the FWD direction and fwd is YES */
641 fwd = GCCH_is_terminal (tch->ch, GNUNET_YES);
643 return GCCH_get_buffer (tch->ch, fwd);
648 * Get the channel's allowance status.
650 * @param tch Tunnel's channel handle.
652 * @return #GNUNET_YES if we allowed the client to send data to us.
655 get_channel_allowed (const struct CadetTChannel *tch)
659 /* If channel is outgoing, is origin in the FWD direction and fwd is YES */
660 fwd = GCCH_is_origin (tch->ch, GNUNET_YES);
662 return GCCH_get_allowed (tch->ch, fwd);
667 * Get the connection's buffer.
669 * @param tc Tunnel's connection handle.
671 * @return Amount of messages the connection can still buffer.
674 get_connection_buffer (const struct CadetTConnection *tc)
678 /* If connection is outgoing, is origin in the FWD direction and fwd is YES */
679 fwd = GCC_is_origin (tc->c, GNUNET_YES);
681 return GCC_get_buffer (tc->c, fwd);
686 * Get the connection's allowance.
688 * @param tc Tunnel's connection handle.
690 * @return Amount of messages we have allowed the next peer to send us.
693 get_connection_allowed (const struct CadetTConnection *tc)
697 /* If connection is outgoing, is origin in the FWD direction and fwd is YES */
698 fwd = GCC_is_origin (tc->c, GNUNET_YES);
700 return GCC_get_allowed (tc->c, fwd);
705 * Check that a ephemeral key message s well formed and correctly signed.
707 * @param t Tunnel on which the message came.
708 * @param msg The ephemeral key message.
710 * @return GNUNET_OK if message is fine, GNUNET_SYSERR otherwise.
713 check_ephemeral (struct CadetTunnel *t,
714 const struct GNUNET_CADET_KX_Ephemeral *msg)
716 /* Check message size */
717 if (ntohs (msg->header.size) != sizeof (struct GNUNET_CADET_KX_Ephemeral))
718 return GNUNET_SYSERR;
720 /* Check signature size */
721 if (ntohl (msg->purpose.size) != ephemeral_purpose_size ())
722 return GNUNET_SYSERR;
725 if (0 != memcmp (&msg->origin_identity,
726 GCP_get_id (t->peer),
727 sizeof (struct GNUNET_PeerIdentity)))
728 return GNUNET_SYSERR;
730 /* Check signature */
732 GNUNET_CRYPTO_eddsa_verify (GNUNET_SIGNATURE_PURPOSE_CADET_KX,
735 &msg->origin_identity.public_key))
736 return GNUNET_SYSERR;
743 * Select the best key to use for encryption (send), based on KX status.
745 * Normally, return the current key. If there is a KX in progress and the old
746 * key is fresh enough, return the old key.
748 * @param t Tunnel to choose the key from.
750 * @return The optimal key to encrypt/hmac outgoing traffic.
752 static const struct GNUNET_CRYPTO_SymmetricSessionKey *
753 select_key (const struct CadetTunnel *t)
755 const struct GNUNET_CRYPTO_SymmetricSessionKey *key;
757 if (NULL != t->kx_ctx
758 && NULL == t->kx_ctx->finish_task)
760 struct GNUNET_TIME_Relative age;
762 age = GNUNET_TIME_absolute_get_duration (t->kx_ctx->rekey_start_time);
763 LOG (GNUNET_ERROR_TYPE_DEBUG,
764 " key exchange in progress, started %s ago\n",
765 GNUNET_STRINGS_relative_time_to_string (age, GNUNET_YES));
766 // FIXME make duration of old keys configurable
767 if (age.rel_value_us < GNUNET_TIME_UNIT_MINUTES.rel_value_us)
769 LOG (GNUNET_ERROR_TYPE_DEBUG, " using old key\n");
770 key = &t->kx_ctx->e_key_old;
774 LOG (GNUNET_ERROR_TYPE_DEBUG, " using new key (old key too old)\n");
780 LOG (GNUNET_ERROR_TYPE_DEBUG, " no KX: using current key\n");
790 * @param plaintext Content to HMAC.
791 * @param size Size of @c plaintext.
792 * @param iv Initialization vector for the message.
793 * @param key Key to use.
794 * @param hmac[out] Destination to store the HMAC.
797 t_hmac (const void *plaintext, size_t size,
798 uint32_t iv, const struct GNUNET_CRYPTO_SymmetricSessionKey *key,
799 struct GNUNET_CADET_Hash *hmac)
801 static const char ctx[] = "cadet authentication key";
802 struct GNUNET_CRYPTO_AuthKey auth_key;
803 struct GNUNET_HashCode hash;
805 #if DUMP_KEYS_TO_STDERR
806 LOG (GNUNET_ERROR_TYPE_INFO, " HMAC with key %s\n",
807 GNUNET_h2s ((struct GNUNET_HashCode *) key));
809 GNUNET_CRYPTO_hmac_derive_key (&auth_key, key,
814 /* Two step: CADET_Hash is only 256 bits, HashCode is 512. */
815 GNUNET_CRYPTO_hmac (&auth_key, plaintext, size, &hash);
816 memcpy (hmac, &hash, sizeof (*hmac));
821 * Encrypt daforce_newest_keyta with the tunnel key.
823 * @param t Tunnel whose key to use.
824 * @param dst Destination for the encrypted data.
825 * @param src Source of the plaintext. Can overlap with @c dst.
826 * @param size Size of the plaintext.
827 * @param iv Initialization Vector to use.
828 * @param force_newest_key Force the use of the newest key, otherwise
829 * CADET will use the old key when allowed.
830 * This can happen in the case when a KX is going on
831 * and the old one hasn't expired.
834 t_encrypt (struct CadetTunnel *t, void *dst, const void *src,
835 size_t size, uint32_t iv, int force_newest_key)
837 struct GNUNET_CRYPTO_SymmetricInitializationVector siv;
838 const struct GNUNET_CRYPTO_SymmetricSessionKey *key;
841 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_encrypt start\n");
843 key = GNUNET_YES == force_newest_key ? &t->e_key : select_key (t);
844 #if DUMP_KEYS_TO_STDERR
845 LOG (GNUNET_ERROR_TYPE_INFO, " ENC with key %s\n",
846 GNUNET_h2s ((struct GNUNET_HashCode *) key));
848 GNUNET_CRYPTO_symmetric_derive_iv (&siv, key, &iv, sizeof (iv), NULL);
849 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_encrypt IV derived\n");
850 out_size = GNUNET_CRYPTO_symmetric_encrypt (src, size, key, &siv, dst);
851 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_encrypt end\n");
858 * Generate a new key with a HMAC mechanism from the existing chain key.
860 * @param ax Axolotl context.
861 * @param key[out] Derived key.
862 * @param source Source key material (data to HMAC).
863 * @param len Length of @a source.
866 t_ax_hmac_hash (struct CadetTunnelAxolotl *ax,
867 struct GNUNET_CRYPTO_SymmetricSessionKey *key,
868 void *source, unsigned int len)
870 static const char ctx[] = "axolotl key derivation";
871 struct GNUNET_CRYPTO_AuthKey auth_key;
872 struct GNUNET_HashCode hash;
874 GNUNET_CRYPTO_hmac_derive_key (&auth_key, &ax->CKs,
877 GNUNET_CRYPTO_hmac (&auth_key, source, len, &hash);
878 GNUNET_CRYPTO_kdf (key, sizeof (*key),
880 &hash, sizeof (hash));
885 * Encrypt data with the tunnel key.
887 * @param t Tunnel whose key to use.
888 * @param dst Destination for the encrypted data.
889 * @param src Source of the plaintext. Can overlap with @c dst.
890 * @param size Size of the plaintext.
892 * @return Size of the encrypted data.
895 t_ax_encrypt (struct CadetTunnel *t, void *dst, const void *src, size_t size)
897 struct GNUNET_CRYPTO_SymmetricSessionKey MK;
898 struct GNUNET_CRYPTO_SymmetricInitializationVector iv;
899 struct CadetTunnelAxolotl *ax;
902 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_ax_encrypt start\n");
906 if (GNUNET_YES == ax->ratchet_flag)
908 /* Advance ratchet */
911 t_ax_hmac_hash (ax, &MK, "0", 1);
912 GNUNET_CRYPTO_symmetric_derive_iv (&iv, &MK, NULL, 0, NULL);
914 #if DUMP_KEYS_TO_STDERR
915 LOG (GNUNET_ERROR_TYPE_INFO, " ENC with key %s\n",
916 GNUNET_h2s ((struct GNUNET_HashCode *) &MK));
919 out_size = GNUNET_CRYPTO_symmetric_encrypt (src, size, &MK, &iv, dst);
921 t_ax_hmac_hash (ax, &ax->CKs, "1", 1);
923 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_ax_encrypt end\n");
930 * Decrypt and verify data with the appropriate tunnel key.
932 * @param key Key to use.
933 * @param dst Destination for the plaintext.
934 * @param src Source of the encrypted data. Can overlap with @c dst.
935 * @param size Size of the encrypted data.
936 * @param iv Initialization Vector to use.
938 * @return Size of the decrypted data, -1 if an error was encountered.
941 decrypt (const struct GNUNET_CRYPTO_SymmetricSessionKey *key,
942 void *dst, const void *src, size_t size, uint32_t iv)
944 struct GNUNET_CRYPTO_SymmetricInitializationVector siv;
947 LOG (GNUNET_ERROR_TYPE_DEBUG, " decrypt start\n");
948 LOG (GNUNET_ERROR_TYPE_DEBUG, " decrypt iv\n");
949 GNUNET_CRYPTO_symmetric_derive_iv (&siv, key, &iv, sizeof (iv), NULL);
950 LOG (GNUNET_ERROR_TYPE_DEBUG, " decrypt iv done\n");
951 out_size = GNUNET_CRYPTO_symmetric_decrypt (src, size, key, &siv, dst);
952 LOG (GNUNET_ERROR_TYPE_DEBUG, " decrypt end\n");
959 * Decrypt and verify data with the most recent tunnel key.
961 * @param t Tunnel whose key to use.
962 * @param dst Destination for the plaintext.
963 * @param src Source of the encrypted data. Can overlap with @c dst.
964 * @param size Size of the encrypted data.
965 * @param iv Initialization Vector to use.
967 * @return Size of the decrypted data, -1 if an error was encountered.
970 t_decrypt (struct CadetTunnel *t, void *dst, const void *src,
971 size_t size, uint32_t iv)
975 #if DUMP_KEYS_TO_STDERR
976 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_decrypt with %s\n",
977 GNUNET_h2s ((struct GNUNET_HashCode *) &t->d_key));
979 if (CADET_TUNNEL_KEY_UNINITIALIZED == t->estate)
981 GNUNET_STATISTICS_update (stats, "# non decryptable data", 1, GNUNET_NO);
982 LOG (GNUNET_ERROR_TYPE_WARNING,
983 "got data on %s without a valid key\n",
985 GCT_debug (t, GNUNET_ERROR_TYPE_WARNING);
989 out_size = decrypt (&t->d_key, dst, src, size, iv);
996 * Decrypt and verify data with the appropriate tunnel key and verify that the
997 * data has not been altered since it was sent by the remote peer.
999 * @param t Tunnel whose key to use.
1000 * @param dst Destination for the plaintext.
1001 * @param src Source of the encrypted data. Can overlap with @c dst.
1002 * @param size Size of the encrypted data.
1003 * @param iv Initialization Vector to use.
1004 * @param msg_hmac HMAC of the message, cannot be NULL.
1006 * @return Size of the decrypted data, -1 if an error was encountered.
1009 t_decrypt_and_validate (struct CadetTunnel *t,
1010 void *dst, const void *src,
1011 size_t size, uint32_t iv,
1012 const struct GNUNET_CADET_Hash *msg_hmac)
1014 struct GNUNET_CRYPTO_SymmetricSessionKey *key;
1015 struct GNUNET_CADET_Hash hmac;
1018 /* Try primary (newest) key */
1020 decrypted_size = decrypt (key, dst, src, size, iv);
1021 t_hmac (src, size, iv, key, &hmac);
1022 if (0 == memcmp (msg_hmac, &hmac, sizeof (hmac)))
1023 return decrypted_size;
1025 /* If no key exchange is going on, we just failed. */
1026 if (NULL == t->kx_ctx)
1028 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
1029 "Failed checksum validation on tunnel %s with no KX\n",
1031 GNUNET_STATISTICS_update (stats, "# wrong HMAC no KX", 1, GNUNET_NO);
1035 /* Try secondary key, from previous KX period. */
1036 key = &t->kx_ctx->d_key_old;
1037 decrypted_size = decrypt (key, dst, src, size, iv);
1038 t_hmac (src, size, iv, key, &hmac);
1039 if (0 == memcmp (msg_hmac, &hmac, sizeof (hmac)))
1040 return decrypted_size;
1042 /* Hail Mary, try tertiary, key, in case of parallel re-keys. */
1043 key = &t->kx_ctx->d_key_old2;
1044 decrypted_size = decrypt (key, dst, src, size, iv);
1045 t_hmac (src, size, iv, key, &hmac);
1046 if (0 == memcmp (msg_hmac, &hmac, sizeof (hmac)))
1047 return decrypted_size;
1049 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
1050 "Failed checksum validation on tunnel %s with KX\n",
1052 GNUNET_STATISTICS_update (stats, "# wrong HMAC with KX", 1, GNUNET_NO);
1057 * Decrypt and verify data with the appropriate tunnel key and verify that the
1058 * data has not been altered since it was sent by the remote peer.
1060 * @param t Tunnel whose key to use.
1061 * @param dst Destination for the plaintext.
1062 * @param src Source of the encrypted data. Can overlap with @c dst.
1063 * @param size Size of the encrypted data.
1064 * @param msg_hmac HMAC of the message, cannot be NULL.
1066 * @return Size of the decrypted data, -1 if an error was encountered.
1069 t_ax_decrypt_and_validate (struct CadetTunnel *t,
1070 void *dst, const void *src, size_t size,
1071 const struct GNUNET_CADET_Hash *msg_hmac)
1073 struct CadetTunnelAxolotl *ax;
1088 * Create key material by doing ECDH on the local and remote ephemeral keys.
1090 * @param key_material Where to store the key material.
1091 * @param ephemeral_key Peer's public ephemeral key.
1094 derive_key_material (struct GNUNET_HashCode *key_material,
1095 const struct GNUNET_CRYPTO_EcdhePublicKey *ephemeral_key)
1098 GNUNET_CRYPTO_ecc_ecdh (my_ephemeral_key,
1108 * Create a symmetic key from the identities of both ends and the key material
1111 * @param key Destination for the generated key.
1112 * @param sender ID of the peer that will encrypt with @c key.
1113 * @param receiver ID of the peer that will decrypt with @c key.
1114 * @param key_material Hash created with ECDH with the ephemeral keys.
1117 derive_symmertic (struct GNUNET_CRYPTO_SymmetricSessionKey *key,
1118 const struct GNUNET_PeerIdentity *sender,
1119 const struct GNUNET_PeerIdentity *receiver,
1120 const struct GNUNET_HashCode *key_material)
1122 const char salt[] = "CADET kx salt";
1124 GNUNET_CRYPTO_kdf (key, sizeof (struct GNUNET_CRYPTO_SymmetricSessionKey),
1125 salt, sizeof (salt),
1126 key_material, sizeof (struct GNUNET_HashCode),
1127 sender, sizeof (struct GNUNET_PeerIdentity),
1128 receiver, sizeof (struct GNUNET_PeerIdentity),
1134 * Derive the tunnel's keys using our own and the peer's ephemeral keys.
1136 * @param t Tunnel for which to create the keys.
1139 create_keys (struct CadetTunnel *t)
1141 struct GNUNET_HashCode km;
1143 derive_key_material (&km, &t->peers_ephemeral_key);
1144 derive_symmertic (&t->e_key, &my_full_id, GCP_get_id (t->peer), &km);
1145 derive_symmertic (&t->d_key, GCP_get_id (t->peer), &my_full_id, &km);
1146 #if DUMP_KEYS_TO_STDERR
1147 LOG (GNUNET_ERROR_TYPE_INFO, "ME: %s\n",
1148 GNUNET_h2s ((struct GNUNET_HashCode *) &kx_msg.ephemeral_key));
1149 LOG (GNUNET_ERROR_TYPE_INFO, "PE: %s\n",
1150 GNUNET_h2s ((struct GNUNET_HashCode *) &t->peers_ephemeral_key));
1151 LOG (GNUNET_ERROR_TYPE_INFO, "KM: %s\n", GNUNET_h2s (&km));
1152 LOG (GNUNET_ERROR_TYPE_INFO, "EK: %s\n",
1153 GNUNET_h2s ((struct GNUNET_HashCode *) &t->e_key));
1154 LOG (GNUNET_ERROR_TYPE_INFO, "DK: %s\n",
1155 GNUNET_h2s ((struct GNUNET_HashCode *) &t->d_key));
1161 * Create a new Key eXchange context for the tunnel.
1163 * If the old keys were verified, keep them for old traffic. Create a new KX
1164 * timestamp and a new nonce.
1166 * @param t Tunnel for which to create the KX ctx.
1169 create_kx_ctx (struct CadetTunnel *t)
1171 LOG (GNUNET_ERROR_TYPE_INFO, " new kx ctx for %s\n", GCT_2s (t));
1173 if (NULL != t->kx_ctx)
1175 if (NULL != t->kx_ctx->finish_task)
1177 LOG (GNUNET_ERROR_TYPE_INFO, " resetting exisiting finish task\n");
1178 GNUNET_SCHEDULER_cancel (t->kx_ctx->finish_task);
1179 t->kx_ctx->finish_task = NULL;
1184 t->kx_ctx = GNUNET_new (struct CadetTunnelKXCtx);
1185 t->kx_ctx->challenge = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE,
1189 if (CADET_TUNNEL_KEY_OK == t->estate)
1191 LOG (GNUNET_ERROR_TYPE_INFO, " backing up keys\n");
1192 t->kx_ctx->d_key_old = t->d_key;
1193 t->kx_ctx->e_key_old = t->e_key;
1196 LOG (GNUNET_ERROR_TYPE_INFO, " old keys not valid, not saving\n");
1197 t->kx_ctx->rekey_start_time = GNUNET_TIME_absolute_get ();
1203 * @brief Finish the Key eXchange and destroy the old keys.
1205 * @param cls Closure (Tunnel for which to finish the KX).
1206 * @param tc Task context.
1209 finish_kx (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
1211 struct CadetTunnel *t = cls;
1213 LOG (GNUNET_ERROR_TYPE_INFO, "finish KX for %s\n", GCT_2s (t));
1215 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
1217 LOG (GNUNET_ERROR_TYPE_INFO, " shutdown\n");
1221 GNUNET_free (t->kx_ctx);
1227 * Destroy a Key eXchange context for the tunnel. This function only schedules
1228 * the destruction, the freeing of the memory (and clearing of old key material)
1229 * happens after a delay!
1231 * @param t Tunnel whose KX ctx to destroy.
1234 destroy_kx_ctx (struct CadetTunnel *t)
1236 struct GNUNET_TIME_Relative delay;
1238 if (NULL == t->kx_ctx || NULL != t->kx_ctx->finish_task)
1241 if (is_key_null (&t->kx_ctx->e_key_old))
1243 t->kx_ctx->finish_task = GNUNET_SCHEDULER_add_now (finish_kx, t);
1247 delay = GNUNET_TIME_relative_divide (rekey_period, 4);
1248 delay = GNUNET_TIME_relative_min (delay, GNUNET_TIME_UNIT_MINUTES);
1250 t->kx_ctx->finish_task = GNUNET_SCHEDULER_add_delayed (delay, finish_kx, t);
1256 * Pick a connection on which send the next data message.
1258 * @param t Tunnel on which to send the message.
1260 * @return The connection on which to send the next message.
1262 static struct CadetConnection *
1263 tunnel_get_connection (struct CadetTunnel *t)
1265 struct CadetTConnection *iter;
1266 struct CadetConnection *best;
1268 unsigned int lowest_q;
1270 LOG (GNUNET_ERROR_TYPE_DEBUG, "tunnel_get_connection %s\n", GCT_2s (t));
1272 lowest_q = UINT_MAX;
1273 for (iter = t->connection_head; NULL != iter; iter = iter->next)
1275 LOG (GNUNET_ERROR_TYPE_DEBUG, " connection %s: %u\n",
1276 GCC_2s (iter->c), GCC_get_state (iter->c));
1277 if (CADET_CONNECTION_READY == GCC_get_state (iter->c))
1279 qn = GCC_get_qn (iter->c, GCC_is_origin (iter->c, GNUNET_YES));
1280 LOG (GNUNET_ERROR_TYPE_DEBUG, " q_n %u, \n", qn);
1288 LOG (GNUNET_ERROR_TYPE_DEBUG, " selected: connection %s\n", GCC_2s (best));
1294 * Callback called when a queued message is sent.
1296 * Calculates the average time and connection packet tracking.
1298 * @param cls Closure (TunnelQueue handle).
1299 * @param c Connection this message was on.
1300 * @param q Connection queue handle (unused).
1301 * @param type Type of message sent.
1302 * @param fwd Was this a FWD going message?
1303 * @param size Size of the message.
1306 tun_message_sent (void *cls,
1307 struct CadetConnection *c,
1308 struct CadetConnectionQueue *q,
1309 uint16_t type, int fwd, size_t size)
1311 struct CadetTunnelQueue *qt = cls;
1312 struct CadetTunnel *t;
1314 LOG (GNUNET_ERROR_TYPE_DEBUG, "tun_message_sent\n");
1316 GNUNET_assert (NULL != qt->cont);
1317 t = NULL == c ? NULL : GCC_get_tunnel (c);
1318 qt->cont (qt->cont_cls, t, qt, type, size);
1324 count_queued_data (const struct CadetTunnel *t)
1326 struct CadetTunnelDelayed *iter;
1329 for (count = 0, iter = t->tq_head; iter != NULL; iter = iter->next)
1336 * Delete a queued message: either was sent or the channel was destroyed
1337 * before the tunnel's key exchange had a chance to finish.
1339 * @param tqd Delayed queue handle.
1342 unqueue_data (struct CadetTunnelDelayed *tqd)
1344 GNUNET_CONTAINER_DLL_remove (tqd->t->tq_head, tqd->t->tq_tail, tqd);
1350 * Cache a message to be sent once tunnel is online.
1352 * @param t Tunnel to hold the message.
1353 * @param msg Message itself (copy will be made).
1355 static struct CadetTunnelDelayed *
1356 queue_data (struct CadetTunnel *t, const struct GNUNET_MessageHeader *msg)
1358 struct CadetTunnelDelayed *tqd;
1359 uint16_t size = ntohs (msg->size);
1361 LOG (GNUNET_ERROR_TYPE_DEBUG, "queue data on Tunnel %s\n", GCT_2s (t));
1363 if (GNUNET_YES == is_ready (t))
1369 tqd = GNUNET_malloc (sizeof (struct CadetTunnelDelayed) + size);
1372 memcpy (&tqd[1], msg, size);
1373 GNUNET_CONTAINER_DLL_insert_tail (t->tq_head, t->tq_tail, tqd);
1379 * Sends an already built message on a tunnel, encrypting it and
1380 * choosing the best connection.
1382 * @param message Message to send. Function modifies it.
1383 * @param t Tunnel on which this message is transmitted.
1384 * @param c Connection to use (autoselect if NULL).
1385 * @param force Force the tunnel to take the message (buffer overfill).
1386 * @param cont Continuation to call once message is really sent.
1387 * @param cont_cls Closure for @c cont.
1388 * @param existing_q In case this a transmission of previously queued data,
1389 * this should be TunnelQueue given to the client.
1392 * @return Handle to cancel message.
1393 * NULL if @c cont is NULL or an error happens and message is dropped.
1395 static struct CadetTunnelQueue *
1396 send_prebuilt_message (const struct GNUNET_MessageHeader *message,
1397 struct CadetTunnel *t, struct CadetConnection *c,
1398 int force, GCT_sent cont, void *cont_cls,
1399 struct CadetTunnelQueue *existing_q)
1401 struct CadetTunnelQueue *tq;
1402 struct GNUNET_CADET_Encrypted *msg;
1403 size_t size = ntohs (message->size);
1404 char cbuf[sizeof (struct GNUNET_CADET_Encrypted) + size];
1411 LOG (GNUNET_ERROR_TYPE_DEBUG, "GMT Send on Tunnel %s\n", GCT_2s (t));
1413 if (GNUNET_NO == is_ready (t))
1415 struct CadetTunnelDelayed *tqd;
1416 /* A non null existing_q indicates sending of queued data.
1417 * Should only happen after tunnel becomes ready.
1419 GNUNET_assert (NULL == existing_q);
1420 tqd = queue_data (t, message);
1423 tq = GNUNET_new (struct CadetTunnelQueue);
1427 tq->cont_cls = cont_cls;
1431 GNUNET_assert (GNUNET_NO == GCT_is_loopback (t));
1433 iv = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX);
1434 msg = (struct GNUNET_CADET_Encrypted *) cbuf;
1435 msg->header.type = htons (GNUNET_MESSAGE_TYPE_CADET_ENCRYPTED);
1438 if (CADET_Axolotl == t->enc_type)
1439 esize = t_ax_encrypt (t, &msg[1], message, size);
1441 esize = t_encrypt (t, &msg[1], message, size, iv, GNUNET_NO);
1442 GNUNET_assert (esize == size);
1443 t_hmac (&msg[1], size, iv, select_key (t), &msg->hmac);
1444 msg->header.size = htons (sizeof (struct GNUNET_CADET_Encrypted) + size);
1447 c = tunnel_get_connection (t);
1450 /* Why is tunnel 'ready'? Should have been queued! */
1451 if (NULL != t->destroy_task)
1454 GCT_debug (t, GNUNET_ERROR_TYPE_WARNING);
1456 return NULL; /* Drop... */
1460 type = ntohs (message->type);
1463 case GNUNET_MESSAGE_TYPE_CADET_DATA:
1464 case GNUNET_MESSAGE_TYPE_CADET_DATA_ACK:
1465 if (GNUNET_MESSAGE_TYPE_CADET_DATA == type)
1466 mid = ntohl (((struct GNUNET_CADET_Data *) message)->mid);
1468 mid = ntohl (((struct GNUNET_CADET_DataACK *) message)->mid);
1470 case GNUNET_MESSAGE_TYPE_CADET_KEEPALIVE:
1471 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_CREATE:
1472 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_DESTROY:
1473 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_ACK:
1474 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_NACK:
1475 msg->cid = *GCC_get_id (c);
1476 msg->ttl = htonl (default_ttl);
1480 LOG (GNUNET_ERROR_TYPE_ERROR, "type %s not valid\n", GC_m2s (type));
1482 LOG (GNUNET_ERROR_TYPE_DEBUG, "type %s\n", GC_m2s (type));
1484 fwd = GCC_is_origin (c, GNUNET_YES);
1488 GNUNET_break (NULL == GCC_send_prebuilt_message (&msg->header, type, mid, c,
1489 fwd, force, NULL, NULL));
1492 if (NULL == existing_q)
1494 tq = GNUNET_new (struct CadetTunnelQueue); /* FIXME valgrind: leak*/
1501 tq->cq = GCC_send_prebuilt_message (&msg->header, type, mid, c, fwd, force,
1502 &tun_message_sent, tq);
1503 GNUNET_assert (NULL != tq->cq);
1505 tq->cont_cls = cont_cls;
1512 * Send all cached messages that we can, tunnel is online.
1514 * @param t Tunnel that holds the messages. Cannot be loopback.
1517 send_queued_data (struct CadetTunnel *t)
1519 struct CadetTunnelDelayed *tqd;
1520 struct CadetTunnelDelayed *next;
1523 LOG (GNUNET_ERROR_TYPE_INFO, "Send queued data, tunnel %s\n", GCT_2s (t));
1525 if (GCT_is_loopback (t))
1531 if (GNUNET_NO == is_ready (t))
1533 LOG (GNUNET_ERROR_TYPE_DEBUG, " not ready yet: %s/%s\n",
1534 estate2s (t->estate), cstate2s (t->cstate));
1538 room = GCT_get_connections_buffer (t);
1539 LOG (GNUNET_ERROR_TYPE_DEBUG, " buffer space: %u\n", room);
1540 LOG (GNUNET_ERROR_TYPE_DEBUG, " tq head: %p\n", t->tq_head);
1541 for (tqd = t->tq_head; NULL != tqd && room > 0; tqd = next)
1543 LOG (GNUNET_ERROR_TYPE_DEBUG, " sending queued data\n");
1546 send_prebuilt_message ((struct GNUNET_MessageHeader *) &tqd[1],
1547 tqd->t, NULL, GNUNET_YES,
1548 NULL != tqd->tq ? tqd->tq->cont : NULL,
1549 NULL != tqd->tq ? tqd->tq->cont_cls : NULL,
1553 LOG (GNUNET_ERROR_TYPE_DEBUG, "GCT_send_queued_data end\n", GCP_2s (t->peer));
1558 * Callback called when a queued message is sent.
1560 * @param cls Closure.
1561 * @param c Connection this message was on.
1562 * @param type Type of message sent.
1563 * @param fwd Was this a FWD going message?
1564 * @param size Size of the message.
1567 ephm_sent (void *cls,
1568 struct CadetConnection *c,
1569 struct CadetConnectionQueue *q,
1570 uint16_t type, int fwd, size_t size)
1572 struct CadetTunnel *t = cls;
1573 LOG (GNUNET_ERROR_TYPE_DEBUG, "ephm_sent %s\n", GC_m2s (type));
1578 * Callback called when a queued message is sent.
1580 * @param cls Closure.
1581 * @param c Connection this message was on.
1582 * @param type Type of message sent.
1583 * @param fwd Was this a FWD going message?
1584 * @param size Size of the message.
1587 pong_sent (void *cls,
1588 struct CadetConnection *c,
1589 struct CadetConnectionQueue *q,
1590 uint16_t type, int fwd, size_t size)
1592 struct CadetTunnel *t = cls;
1593 LOG (GNUNET_ERROR_TYPE_DEBUG, "pong_sent %s\n", GC_m2s (type));
1599 * Sends key exchange message on a tunnel, choosing the best connection.
1600 * Should not be called on loopback tunnels.
1602 * @param t Tunnel on which this message is transmitted.
1603 * @param message Message to send. Function modifies it.
1605 * @return Handle to the message in the connection queue.
1607 static struct CadetConnectionQueue *
1608 send_kx (struct CadetTunnel *t,
1609 const struct GNUNET_MessageHeader *message)
1611 struct CadetConnection *c;
1612 struct GNUNET_CADET_KX *msg;
1613 size_t size = ntohs (message->size);
1614 char cbuf[sizeof (struct GNUNET_CADET_KX) + size];
1619 LOG (GNUNET_ERROR_TYPE_DEBUG, "GMT KX on Tunnel %s\n", GCT_2s (t));
1621 /* Avoid loopback. */
1622 if (GCT_is_loopback (t))
1624 LOG (GNUNET_ERROR_TYPE_DEBUG, " loopback!\n");
1628 type = ntohs (message->type);
1630 /* Even if tunnel is "being destroyed", send anyway.
1631 * Could be a response to a rekey initiated by remote peer,
1632 * who is trying to create a new channel!
1635 /* Must have a connection, or be looking for one. */
1636 if (NULL == t->connection_head)
1638 LOG (GNUNET_ERROR_TYPE_DEBUG, "%s while no connection\n", GC_m2s (type));
1639 if (CADET_TUNNEL_SEARCHING != t->cstate)
1642 GCT_debug (t, GNUNET_ERROR_TYPE_ERROR);
1643 GCP_debug (t->peer, GNUNET_ERROR_TYPE_ERROR);
1648 msg = (struct GNUNET_CADET_KX *) cbuf;
1649 msg->header.type = htons (GNUNET_MESSAGE_TYPE_CADET_KX);
1650 msg->header.size = htons (sizeof (struct GNUNET_CADET_KX) + size);
1651 c = tunnel_get_connection (t);
1654 if (NULL == t->destroy_task
1655 && CADET_TUNNEL_READY == t->cstate)
1658 GCT_debug (t, GNUNET_ERROR_TYPE_ERROR);
1664 case GNUNET_MESSAGE_TYPE_CADET_KX_EPHEMERAL:
1665 GNUNET_assert (NULL == t->ephm_h);
1667 memcpy (&msg[1], message, size);
1669 case GNUNET_MESSAGE_TYPE_CADET_KX_PONG:
1670 GNUNET_assert (NULL == t->pong_h);
1672 memcpy (&msg[1], message, size);
1676 LOG (GNUNET_ERROR_TYPE_DEBUG, "unkown type %s\n", GC_m2s (type));
1680 fwd = GCC_is_origin (c, GNUNET_YES);
1682 return GCC_send_prebuilt_message (&msg->header, type, 0, c,
1689 * Send the ephemeral key on a tunnel.
1691 * @param t Tunnel on which to send the key.
1694 send_ephemeral (struct CadetTunnel *t)
1696 LOG (GNUNET_ERROR_TYPE_INFO, "===> EPHM for %s\n", GCT_2s (t));
1697 if (NULL != t->ephm_h)
1699 LOG (GNUNET_ERROR_TYPE_INFO, " already queued\n");
1703 kx_msg.sender_status = htonl (t->estate);
1704 kx_msg.iv = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX);
1705 kx_msg.nonce = t->kx_ctx->challenge;
1706 LOG (GNUNET_ERROR_TYPE_DEBUG, " send nonce c %u\n", kx_msg.nonce);
1707 t_encrypt (t, &kx_msg.nonce, &kx_msg.nonce,
1708 ping_encryption_size(), kx_msg.iv, GNUNET_YES);
1709 LOG (GNUNET_ERROR_TYPE_DEBUG, " send nonce e %u\n", kx_msg.nonce);
1710 t->ephm_h = send_kx (t, &kx_msg.header);
1715 * Send a pong message on a tunnel.
1717 * @param t Tunnel on which to send the pong.
1718 * @param challenge Value sent in the ping that we have to send back.
1721 send_pong (struct CadetTunnel *t, uint32_t challenge)
1723 struct GNUNET_CADET_KX_Pong msg;
1725 LOG (GNUNET_ERROR_TYPE_INFO, "===> PONG for %s\n", GCT_2s (t));
1726 if (NULL != t->pong_h)
1728 LOG (GNUNET_ERROR_TYPE_INFO, " already queued\n");
1731 msg.header.size = htons (sizeof (msg));
1732 msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_KX_PONG);
1733 msg.iv = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX);
1734 msg.nonce = challenge;
1735 LOG (GNUNET_ERROR_TYPE_DEBUG, " sending %u\n", msg.nonce);
1736 t_encrypt (t, &msg.nonce, &msg.nonce,
1737 sizeof (msg.nonce), msg.iv, GNUNET_YES);
1738 LOG (GNUNET_ERROR_TYPE_DEBUG, " e sending %u\n", msg.nonce);
1740 t->pong_h = send_kx (t, &msg.header);
1745 * Initiate a rekey with the remote peer.
1747 * @param cls Closure (tunnel).
1748 * @param tc TaskContext.
1751 rekey_tunnel (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
1753 struct CadetTunnel *t = cls;
1755 t->rekey_task = NULL;
1757 LOG (GNUNET_ERROR_TYPE_INFO, "Re-key Tunnel %s\n", GCT_2s (t));
1758 if (NULL != tc && 0 != (GNUNET_SCHEDULER_REASON_SHUTDOWN & tc->reason))
1761 GNUNET_assert (NULL != t->kx_ctx);
1762 struct GNUNET_TIME_Relative duration;
1764 duration = GNUNET_TIME_absolute_get_duration (t->kx_ctx->rekey_start_time);
1765 LOG (GNUNET_ERROR_TYPE_DEBUG, " kx started %s ago\n",
1766 GNUNET_STRINGS_relative_time_to_string (duration, GNUNET_YES));
1768 // FIXME make duration of old keys configurable
1769 if (duration.rel_value_us >= GNUNET_TIME_UNIT_MINUTES.rel_value_us)
1771 LOG (GNUNET_ERROR_TYPE_DEBUG, " deleting old keys\n");
1772 memset (&t->kx_ctx->d_key_old, 0, sizeof (t->kx_ctx->d_key_old));
1773 memset (&t->kx_ctx->e_key_old, 0, sizeof (t->kx_ctx->e_key_old));
1780 case CADET_TUNNEL_KEY_UNINITIALIZED:
1781 GCT_change_estate (t, CADET_TUNNEL_KEY_SENT);
1784 case CADET_TUNNEL_KEY_SENT:
1787 case CADET_TUNNEL_KEY_OK:
1789 * - state should have changed during rekey_iterator
1790 * - task should have been canceled at pong_handle
1793 GCT_change_estate (t, CADET_TUNNEL_KEY_REKEY);
1796 case CADET_TUNNEL_KEY_PING:
1797 case CADET_TUNNEL_KEY_REKEY:
1801 LOG (GNUNET_ERROR_TYPE_DEBUG, "Unexpected state %u\n", t->estate);
1804 // FIXME exponential backoff
1805 struct GNUNET_TIME_Relative delay;
1807 delay = GNUNET_TIME_relative_divide (rekey_period, 16);
1808 delay = GNUNET_TIME_relative_min (delay, REKEY_WAIT);
1809 LOG (GNUNET_ERROR_TYPE_DEBUG, " next call in %s\n",
1810 GNUNET_STRINGS_relative_time_to_string (delay, GNUNET_YES));
1811 t->rekey_task = GNUNET_SCHEDULER_add_delayed (delay, &rekey_tunnel, t);
1816 * Our ephemeral key has changed, create new session key on all tunnels.
1818 * Each tunnel will start the Key Exchange with a random delay between
1819 * 0 and number_of_tunnels*100 milliseconds, so there are 10 key exchanges
1820 * per second, on average.
1822 * @param cls Closure (size of the hashmap).
1823 * @param key Current public key.
1824 * @param value Value in the hash map (tunnel).
1826 * @return #GNUNET_YES, so we should continue to iterate,
1829 rekey_iterator (void *cls,
1830 const struct GNUNET_PeerIdentity *key,
1833 struct CadetTunnel *t = value;
1834 struct GNUNET_TIME_Relative delay;
1835 long n = (long) cls;
1838 if (NULL != t->rekey_task)
1841 if (GNUNET_YES == GCT_is_loopback (t))
1844 r = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK, (uint32_t) n * 100);
1845 delay = GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MILLISECONDS, r);
1846 t->rekey_task = GNUNET_SCHEDULER_add_delayed (delay, &rekey_tunnel, t);
1848 GCT_change_estate (t, CADET_TUNNEL_KEY_REKEY);
1855 * Create a new ephemeral key and key message, schedule next rekeying.
1857 * @param cls Closure (unused).
1858 * @param tc TaskContext.
1861 rekey (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
1863 struct GNUNET_TIME_Absolute time;
1868 if (0 != (GNUNET_SCHEDULER_REASON_SHUTDOWN & tc->reason))
1871 GNUNET_free_non_null (my_ephemeral_key);
1872 my_ephemeral_key = GNUNET_CRYPTO_ecdhe_key_create ();
1874 time = GNUNET_TIME_absolute_get ();
1875 kx_msg.creation_time = GNUNET_TIME_absolute_hton (time);
1876 time = GNUNET_TIME_absolute_add (time, rekey_period);
1877 time = GNUNET_TIME_absolute_add (time, GNUNET_TIME_UNIT_MINUTES);
1878 kx_msg.expiration_time = GNUNET_TIME_absolute_hton (time);
1879 GNUNET_CRYPTO_ecdhe_key_get_public (my_ephemeral_key, &kx_msg.ephemeral_key);
1880 LOG (GNUNET_ERROR_TYPE_INFO, "GLOBAL RE-KEY, NEW EPHM: %s\n",
1881 GNUNET_h2s ((struct GNUNET_HashCode *) &kx_msg.ephemeral_key));
1883 GNUNET_assert (GNUNET_OK ==
1884 GNUNET_CRYPTO_eddsa_sign (my_private_key,
1886 &kx_msg.signature));
1888 n = (long) GNUNET_CONTAINER_multipeermap_size (tunnels);
1889 GNUNET_CONTAINER_multipeermap_iterate (tunnels, &rekey_iterator, (void *) n);
1891 rekey_task = GNUNET_SCHEDULER_add_delayed (rekey_period, &rekey, NULL);
1896 * Called only on shutdown, destroy every tunnel.
1898 * @param cls Closure (unused).
1899 * @param key Current public key.
1900 * @param value Value in the hash map (tunnel).
1902 * @return #GNUNET_YES, so we should continue to iterate,
1905 destroy_iterator (void *cls,
1906 const struct GNUNET_PeerIdentity *key,
1909 struct CadetTunnel *t = value;
1911 LOG (GNUNET_ERROR_TYPE_DEBUG, "GCT_shutdown destroying tunnel at %p\n", t);
1918 * Notify remote peer that we don't know a channel he is talking about,
1919 * probably CHANNEL_DESTROY was missed.
1921 * @param t Tunnel on which to notify.
1922 * @param gid ID of the channel.
1925 send_channel_destroy (struct CadetTunnel *t, unsigned int gid)
1927 struct GNUNET_CADET_ChannelManage msg;
1929 msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_CHANNEL_DESTROY);
1930 msg.header.size = htons (sizeof (msg));
1931 msg.chid = htonl (gid);
1933 LOG (GNUNET_ERROR_TYPE_DEBUG,
1934 "WARNING destroying unknown channel %u on tunnel %s\n",
1936 send_prebuilt_message (&msg.header, t, NULL, GNUNET_YES, NULL, NULL, NULL);
1941 * Demultiplex data per channel and call appropriate channel handler.
1943 * @param t Tunnel on which the data came.
1944 * @param msg Data message.
1945 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
1946 * #GNUNET_YES if message is FWD on the respective channel (loopback)
1947 * #GNUNET_NO if message is BCK on the respective channel (loopback)
1948 * #GNUNET_SYSERR if message on a one-ended channel (remote)
1951 handle_data (struct CadetTunnel *t,
1952 const struct GNUNET_CADET_Data *msg,
1955 struct CadetChannel *ch;
1959 size = ntohs (msg->header.size);
1961 sizeof (struct GNUNET_CADET_Data) +
1962 sizeof (struct GNUNET_MessageHeader))
1967 LOG (GNUNET_ERROR_TYPE_DEBUG, " payload of type %s\n",
1968 GC_m2s (ntohs (msg[1].header.type)));
1971 ch = GCT_get_channel (t, ntohl (msg->chid));
1974 GNUNET_STATISTICS_update (stats, "# data on unknown channel",
1976 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel 0x%X unknown\n",
1978 send_channel_destroy (t, ntohl (msg->chid));
1982 GCCH_handle_data (ch, msg, fwd);
1987 * Demultiplex data ACKs per channel and update appropriate channel buffer info.
1989 * @param t Tunnel on which the DATA ACK came.
1990 * @param msg DATA ACK message.
1991 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
1992 * #GNUNET_YES if message is FWD on the respective channel (loopback)
1993 * #GNUNET_NO if message is BCK on the respective channel (loopback)
1994 * #GNUNET_SYSERR if message on a one-ended channel (remote)
1997 handle_data_ack (struct CadetTunnel *t,
1998 const struct GNUNET_CADET_DataACK *msg,
2001 struct CadetChannel *ch;
2005 size = ntohs (msg->header.size);
2006 if (size != sizeof (struct GNUNET_CADET_DataACK))
2013 ch = GCT_get_channel (t, ntohl (msg->chid));
2016 GNUNET_STATISTICS_update (stats, "# data ack on unknown channel",
2018 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel %u unknown\n",
2023 GCCH_handle_data_ack (ch, msg, fwd);
2028 * Handle channel create.
2030 * @param t Tunnel on which the data came.
2031 * @param msg Data message.
2034 handle_ch_create (struct CadetTunnel *t,
2035 const struct GNUNET_CADET_ChannelCreate *msg)
2037 struct CadetChannel *ch;
2041 size = ntohs (msg->header.size);
2042 if (size != sizeof (struct GNUNET_CADET_ChannelCreate))
2049 ch = GCT_get_channel (t, ntohl (msg->chid));
2050 if (NULL != ch && ! GCT_is_loopback (t))
2052 /* Probably a retransmission, safe to ignore */
2053 LOG (GNUNET_ERROR_TYPE_DEBUG, " already exists...\n");
2055 ch = GCCH_handle_create (t, msg);
2057 GCT_add_channel (t, ch);
2063 * Handle channel NACK: check correctness and call channel handler for NACKs.
2065 * @param t Tunnel on which the NACK came.
2066 * @param msg NACK message.
2069 handle_ch_nack (struct CadetTunnel *t,
2070 const struct GNUNET_CADET_ChannelManage *msg)
2072 struct CadetChannel *ch;
2076 size = ntohs (msg->header.size);
2077 if (size != sizeof (struct GNUNET_CADET_ChannelManage))
2084 ch = GCT_get_channel (t, ntohl (msg->chid));
2087 GNUNET_STATISTICS_update (stats, "# channel NACK on unknown channel",
2089 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel %u unknown\n",
2094 GCCH_handle_nack (ch);
2099 * Handle a CHANNEL ACK (SYNACK/ACK).
2101 * @param t Tunnel on which the CHANNEL ACK came.
2102 * @param msg CHANNEL ACK message.
2103 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
2104 * #GNUNET_YES if message is FWD on the respective channel (loopback)
2105 * #GNUNET_NO if message is BCK on the respective channel (loopback)
2106 * #GNUNET_SYSERR if message on a one-ended channel (remote)
2109 handle_ch_ack (struct CadetTunnel *t,
2110 const struct GNUNET_CADET_ChannelManage *msg,
2113 struct CadetChannel *ch;
2117 size = ntohs (msg->header.size);
2118 if (size != sizeof (struct GNUNET_CADET_ChannelManage))
2125 ch = GCT_get_channel (t, ntohl (msg->chid));
2128 GNUNET_STATISTICS_update (stats, "# channel ack on unknown channel",
2130 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel %u unknown\n",
2135 GCCH_handle_ack (ch, msg, fwd);
2140 * Handle a channel destruction message.
2142 * @param t Tunnel on which the message came.
2143 * @param msg Channel destroy message.
2144 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
2145 * #GNUNET_YES if message is FWD on the respective channel (loopback)
2146 * #GNUNET_NO if message is BCK on the respective channel (loopback)
2147 * #GNUNET_SYSERR if message on a one-ended channel (remote)
2150 handle_ch_destroy (struct CadetTunnel *t,
2151 const struct GNUNET_CADET_ChannelManage *msg,
2154 struct CadetChannel *ch;
2158 size = ntohs (msg->header.size);
2159 if (size != sizeof (struct GNUNET_CADET_ChannelManage))
2166 ch = GCT_get_channel (t, ntohl (msg->chid));
2169 /* Probably a retransmission, safe to ignore */
2173 GCCH_handle_destroy (ch, msg, fwd);
2178 * Create a new Axolotl ephemeral (ratchet) key.
2183 new_ephemeral (struct CadetTunnel *t)
2185 GNUNET_free_non_null (t->ax->DHRs);
2186 t->ax->DHRs = GNUNET_CRYPTO_ecdhe_key_create();
2191 * Free Axolotl data.
2196 destroy_ax (struct CadetTunnel *t)
2201 GNUNET_free_non_null (t->ax->DHRs);
2202 GNUNET_free_non_null (t->ax->kx_0);
2204 GNUNET_free (t->ax);
2211 * The peer's ephemeral key has changed: update the symmetrical keys.
2213 * @param t Tunnel this message came on.
2214 * @param msg Key eXchange message.
2217 handle_ephemeral (struct CadetTunnel *t,
2218 const struct GNUNET_CADET_KX_Ephemeral *msg)
2220 LOG (GNUNET_ERROR_TYPE_INFO, "<=== EPHM for %s\n", GCT_2s (t));
2222 if (GNUNET_OK != check_ephemeral (t, msg))
2224 GNUNET_break_op (0);
2228 /* If we get a proper OTR-style ephemeral, fallback to old crypto. */
2232 t->enc_type = CADET_Fallback;
2236 * If the key is different from what we know, derive the new E/D keys.
2237 * Else destroy the rekey ctx (duplicate EPHM after successful KX).
2239 if (0 != memcmp (&t->peers_ephemeral_key, &msg->ephemeral_key,
2240 sizeof (msg->ephemeral_key)))
2242 #if DUMP_KEYS_TO_STDERR
2243 LOG (GNUNET_ERROR_TYPE_INFO, "OLD: %s\n",
2244 GNUNET_h2s ((struct GNUNET_HashCode *) &t->peers_ephemeral_key));
2245 LOG (GNUNET_ERROR_TYPE_INFO, "NEW: %s\n",
2246 GNUNET_h2s ((struct GNUNET_HashCode *) &msg->ephemeral_key));
2248 t->peers_ephemeral_key = msg->ephemeral_key;
2252 if (CADET_TUNNEL_KEY_OK == t->estate)
2254 GCT_change_estate (t, CADET_TUNNEL_KEY_REKEY);
2256 if (NULL != t->rekey_task)
2257 GNUNET_SCHEDULER_cancel (t->rekey_task);
2258 t->rekey_task = GNUNET_SCHEDULER_add_now (rekey_tunnel, t);
2260 if (CADET_TUNNEL_KEY_SENT == t->estate)
2262 LOG (GNUNET_ERROR_TYPE_DEBUG, " our key was sent, sending challenge\n");
2264 GCT_change_estate (t, CADET_TUNNEL_KEY_PING);
2267 if (CADET_TUNNEL_KEY_UNINITIALIZED != ntohl(msg->sender_status))
2271 LOG (GNUNET_ERROR_TYPE_DEBUG, " recv nonce e %u\n", msg->nonce);
2272 t_decrypt (t, &nonce, &msg->nonce, ping_encryption_size (), msg->iv);
2273 LOG (GNUNET_ERROR_TYPE_DEBUG, " recv nonce c %u\n", nonce);
2274 send_pong (t, nonce);
2280 * Peer has answer to our challenge.
2281 * If answer is successful, consider the key exchange finished and clean
2282 * up all related state.
2284 * @param t Tunnel this message came on.
2285 * @param msg Key eXchange Pong message.
2288 handle_pong (struct CadetTunnel *t, const struct GNUNET_CADET_KX_Pong *msg)
2292 LOG (GNUNET_ERROR_TYPE_INFO, "<=== PONG for %s\n", GCT_2s (t));
2293 if (NULL == t->rekey_task)
2295 GNUNET_STATISTICS_update (stats, "# duplicate PONG messages", 1, GNUNET_NO);
2298 if (NULL == t->kx_ctx)
2300 GNUNET_STATISTICS_update (stats, "# stray PONG messages", 1, GNUNET_NO);
2304 t_decrypt (t, &challenge, &msg->nonce, sizeof (uint32_t), msg->iv);
2305 if (challenge != t->kx_ctx->challenge)
2307 LOG (GNUNET_ERROR_TYPE_WARNING, "Wrong PONG challenge on %s\n", GCT_2s (t));
2308 LOG (GNUNET_ERROR_TYPE_DEBUG, "PONG: %u (e: %u). Expected: %u.\n",
2309 challenge, msg->nonce, t->kx_ctx->challenge);
2313 GNUNET_SCHEDULER_cancel (t->rekey_task);
2314 t->rekey_task = NULL;
2316 /* Don't free the old keys right away, but after a delay.
2317 * Rationale: the KX could have happened over a very fast connection,
2318 * with payload traffic still signed with the old key stuck in a slower
2320 * Don't keep the keys longer than 1/4 the rekey period, and no longer than
2324 GCT_change_estate (t, CADET_TUNNEL_KEY_OK);
2329 * WARNING! DANGER! Do not use this if you don't know what you are doing!
2330 * Ask Christian Grothoff, Werner Koch, Dan Bernstein and $GOD!
2332 * Transform a private EdDSA key (peer's key) into a key usable by DH.
2334 * @param k Private EdDSA key to transform.
2336 * @return Private key for EC Diffie-Hellman.
2338 static const struct GNUNET_CRYPTO_EcdhePrivateKey *
2339 get_private_ecdhe_from_eddsa (const struct GNUNET_CRYPTO_EddsaPrivateKey *k)
2341 return (const struct GNUNET_CRYPTO_EcdhePrivateKey *) k;
2346 * WARNING! DANGER! Do not use this if you don't know what you are doing!
2347 * Ask Christian Grothoff, Werner Koch, Dan Bernstein and $GOD!
2349 * Transform a public EdDSA key (peer's key) into a key usable by DH.
2351 * @param k Public EdDSA key to transform (peer's ID).
2353 * @return Public key for EC Diffie-Hellman.
2355 static const struct GNUNET_CRYPTO_EcdhePublicKey *
2356 get_public_ecdhe_from_id (const struct GNUNET_PeerIdentity *id)
2358 return (const struct GNUNET_CRYPTO_EcdhePublicKey *) id;
2363 * Handle Axolotl handshake.
2365 * @param t Tunnel this message came on.
2366 * @param msg Key eXchange Pong message.
2369 handle_kx_ax (struct CadetTunnel *t, const struct GNUNET_CADET_AX_KX *msg)
2371 struct CadetTunnelAxolotl *ax;
2372 struct GNUNET_HashCode key_material[3];
2373 struct GNUNET_CRYPTO_SymmetricSessionKey keys[5];
2374 const struct GNUNET_CRYPTO_EcdhePublicKey *pub;
2375 const struct GNUNET_CRYPTO_EcdhePrivateKey *priv;
2376 const char salt[] = "CADET Axolotl salt";
2377 const struct GNUNET_PeerIdentity *pid;
2382 /* Something is wrong if ax is NULL. Whose fault it is? */
2383 GNUNET_break_op (CADET_Fallback == t->enc_type);
2384 GNUNET_break (CADET_Axolotl == t->enc_type);
2388 pid = GCT_get_destination (t);
2389 if (0 > GNUNET_CRYPTO_cmp_peer_identity (&my_full_id, pid))
2390 is_alice = GNUNET_YES;
2391 else if (0 > GNUNET_CRYPTO_cmp_peer_identity (&my_full_id, pid))
2392 is_alice = GNUNET_NO;
2395 GNUNET_break_op (0);
2400 ax->DHRr = msg->ratchet_key;
2403 if (GNUNET_YES == is_alice)
2405 priv = get_private_ecdhe_from_eddsa (my_private_key); /* A */
2406 pub = &msg->ephemeral_key; /* B0 */
2410 priv = ax->kx_0; /* B0 */
2411 pub = get_public_ecdhe_from_id (pid); /* A */
2413 GNUNET_CRYPTO_ecc_ecdh (priv, pub, &key_material[0]);
2416 if (GNUNET_YES == is_alice)
2418 priv = ax->kx_0; /* A0 */
2419 pub = get_public_ecdhe_from_id (pid); /* B */
2423 priv = get_private_ecdhe_from_eddsa (my_private_key); /* B */
2424 pub = &msg->ephemeral_key; /* A0 */
2426 GNUNET_CRYPTO_ecc_ecdh (priv, pub, &key_material[1]);
2429 priv = ax->kx_0; /* A0 or B0 */
2430 pub = &msg->ephemeral_key; /* B0 or A0 */
2431 GNUNET_CRYPTO_ecc_ecdh (priv, pub, &key_material[2]);
2434 GNUNET_CRYPTO_kdf (keys, sizeof (keys),
2435 salt, sizeof (salt),
2436 key_material, sizeof (key_material), NULL);
2439 if (GNUNET_YES == is_alice)
2445 ax->ratchet_flag = GNUNET_YES;
2453 ax->ratchet_flag = GNUNET_NO;
2459 * Demultiplex by message type and call appropriate handler for a message
2460 * towards a channel of a local tunnel.
2462 * @param t Tunnel this message came on.
2463 * @param msgh Message header.
2464 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
2465 * #GNUNET_YES if message is FWD on the respective channel (loopback)
2466 * #GNUNET_NO if message is BCK on the respective channel (loopback)
2467 * #GNUNET_SYSERR if message on a one-ended channel (remote)
2470 handle_decrypted (struct CadetTunnel *t,
2471 const struct GNUNET_MessageHeader *msgh,
2476 type = ntohs (msgh->type);
2477 LOG (GNUNET_ERROR_TYPE_INFO, "<=== %s on %s\n", GC_m2s (type), GCT_2s (t));
2481 case GNUNET_MESSAGE_TYPE_CADET_KEEPALIVE:
2482 /* Do nothing, connection aleady got updated. */
2483 GNUNET_STATISTICS_update (stats, "# keepalives received", 1, GNUNET_NO);
2486 case GNUNET_MESSAGE_TYPE_CADET_DATA:
2487 /* Don't send hop ACK, wait for client to ACK */
2488 handle_data (t, (struct GNUNET_CADET_Data *) msgh, fwd);
2491 case GNUNET_MESSAGE_TYPE_CADET_DATA_ACK:
2492 handle_data_ack (t, (struct GNUNET_CADET_DataACK *) msgh, fwd);
2495 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_CREATE:
2496 handle_ch_create (t, (struct GNUNET_CADET_ChannelCreate *) msgh);
2499 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_NACK:
2500 handle_ch_nack (t, (struct GNUNET_CADET_ChannelManage *) msgh);
2503 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_ACK:
2504 handle_ch_ack (t, (struct GNUNET_CADET_ChannelManage *) msgh, fwd);
2507 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_DESTROY:
2508 handle_ch_destroy (t, (struct GNUNET_CADET_ChannelManage *) msgh, fwd);
2512 GNUNET_break_op (0);
2513 LOG (GNUNET_ERROR_TYPE_WARNING,
2514 "end-to-end message not known (%u)\n",
2515 ntohs (msgh->type));
2516 GCT_debug (t, GNUNET_ERROR_TYPE_WARNING);
2520 /******************************************************************************/
2521 /******************************** API ***********************************/
2522 /******************************************************************************/
2524 * Decrypt old format and demultiplex by message type. Call appropriate handler
2525 * for a message towards a channel of a local tunnel.
2527 * @param t Tunnel this message came on.
2528 * @param msg Message header.
2531 GCT_handle_encrypted (struct CadetTunnel *t,
2532 const struct GNUNET_MessageHeader *msg)
2534 size_t size = ntohs (msg->size);
2535 size_t payload_size;
2538 uint16_t type = ntohs (msg->type);
2539 struct GNUNET_MessageHeader *msgh;
2542 if (GNUNET_MESSAGE_TYPE_CADET_ENCRYPTED == type)
2544 const struct GNUNET_CADET_Encrypted *emsg;
2546 emsg = (struct GNUNET_CADET_Encrypted *) msg;
2547 payload_size = size - sizeof (struct GNUNET_CADET_Encrypted);
2548 decrypted_size = t_decrypt_and_validate (t, cbuf, &emsg[1], payload_size,
2549 emsg->iv, &emsg->hmac);
2551 else if (GNUNET_MESSAGE_TYPE_CADET_AX == type)
2553 const struct GNUNET_CADET_AX *emsg;
2555 emsg = (struct GNUNET_CADET_AX *) msg;
2556 payload_size = size - sizeof (struct GNUNET_CADET_AX);
2557 decrypted_size = t_ax_decrypt_and_validate (t, cbuf, &emsg[1],
2558 payload_size, &emsg->hmac);
2561 if (-1 == decrypted_size)
2563 GNUNET_break_op (0);
2568 while (off < decrypted_size)
2572 msgh = (struct GNUNET_MessageHeader *) &cbuf[off];
2573 msize = ntohs (msgh->size);
2574 if (msize < sizeof (struct GNUNET_MessageHeader))
2576 GNUNET_break_op (0);
2579 handle_decrypted (t, msgh, GNUNET_SYSERR);
2586 * Demultiplex an encapsulated KX message by message type.
2588 * @param t Tunnel on which the message came.
2589 * @param message Payload of KX message.
2592 GCT_handle_kx (struct CadetTunnel *t,
2593 const struct GNUNET_MessageHeader *message)
2597 type = ntohs (message->type);
2598 LOG (GNUNET_ERROR_TYPE_DEBUG, "kx message received: %s\n", GC_m2s (type));
2601 case GNUNET_MESSAGE_TYPE_CADET_KX_EPHEMERAL:
2602 handle_ephemeral (t, (const struct GNUNET_CADET_KX_Ephemeral *) message);
2605 case GNUNET_MESSAGE_TYPE_CADET_KX_PONG:
2606 handle_pong (t, (const struct GNUNET_CADET_KX_Pong *) message);
2609 case GNUNET_MESSAGE_TYPE_CADET_AX_KX:
2610 handle_kx_ax (t, (const struct GNUNET_CADET_AX_KX *) message);
2614 GNUNET_break_op (0);
2615 LOG (GNUNET_ERROR_TYPE_WARNING, "kx message %s unknown\n", GC_m2s (type));
2621 * Initialize the tunnel subsystem.
2623 * @param c Configuration handle.
2624 * @param key ECC private key, to derive all other keys and do crypto.
2627 GCT_init (const struct GNUNET_CONFIGURATION_Handle *c,
2628 const struct GNUNET_CRYPTO_EddsaPrivateKey *key)
2630 int expected_overhead;
2632 LOG (GNUNET_ERROR_TYPE_DEBUG, "init\n");
2634 expected_overhead = 0;
2635 expected_overhead += sizeof (struct GNUNET_CADET_Encrypted);
2636 expected_overhead += sizeof (struct GNUNET_CADET_Data);
2637 expected_overhead += sizeof (struct GNUNET_CADET_ACK);
2638 GNUNET_assert (GNUNET_CONSTANTS_CADET_P2P_OVERHEAD == expected_overhead);
2641 GNUNET_CONFIGURATION_get_value_number (c, "CADET", "DEFAULT_TTL",
2644 GNUNET_log_config_invalid (GNUNET_ERROR_TYPE_WARNING,
2645 "CADET", "DEFAULT_TTL", "USING DEFAULT");
2649 GNUNET_CONFIGURATION_get_value_time (c, "CADET", "REKEY_PERIOD",
2652 rekey_period = GNUNET_TIME_UNIT_DAYS;
2655 my_private_key = key;
2657 kx_msg.header.size = htons (sizeof (kx_msg));
2658 kx_msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_KX_EPHEMERAL);
2659 kx_msg.purpose.purpose = htonl (GNUNET_SIGNATURE_PURPOSE_CADET_KX);
2660 kx_msg.purpose.size = htonl (ephemeral_purpose_size ());
2661 kx_msg.origin_identity = my_full_id;
2662 rekey_task = GNUNET_SCHEDULER_add_now (&rekey, NULL);
2664 tunnels = GNUNET_CONTAINER_multipeermap_create (128, GNUNET_YES);
2669 * Shut down the tunnel subsystem.
2674 if (NULL != rekey_task)
2676 GNUNET_SCHEDULER_cancel (rekey_task);
2679 GNUNET_CONTAINER_multipeermap_iterate (tunnels, &destroy_iterator, NULL);
2680 GNUNET_CONTAINER_multipeermap_destroy (tunnels);
2687 * @param destination Peer this tunnel is towards.
2689 struct CadetTunnel *
2690 GCT_new (struct CadetPeer *destination)
2692 struct CadetTunnel *t;
2694 t = GNUNET_new (struct CadetTunnel);
2696 t->peer = destination;
2699 GNUNET_CONTAINER_multipeermap_put (tunnels, GCP_get_id (destination), t,
2700 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_FAST))
2706 t->ax = GNUNET_new (struct CadetTunnelAxolotl);
2708 t->ax->kx_0 = GNUNET_CRYPTO_ecdhe_key_create ();
2714 * Change the tunnel's connection state.
2716 * @param t Tunnel whose connection state to change.
2717 * @param cstate New connection state.
2720 GCT_change_cstate (struct CadetTunnel* t, enum CadetTunnelCState cstate)
2724 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel %s cstate %s => %s\n",
2725 GCP_2s (t->peer), cstate2s (t->cstate), cstate2s (cstate));
2726 if (myid != GCP_get_short_id (t->peer) &&
2727 CADET_TUNNEL_READY != t->cstate &&
2728 CADET_TUNNEL_READY == cstate)
2731 if (CADET_TUNNEL_KEY_OK == t->estate)
2733 LOG (GNUNET_ERROR_TYPE_DEBUG, " cstate triggered send queued data\n");
2734 send_queued_data (t);
2736 else if (CADET_TUNNEL_KEY_UNINITIALIZED == t->estate)
2738 LOG (GNUNET_ERROR_TYPE_DEBUG, " cstate triggered rekey\n");
2739 if (NULL != t->rekey_task)
2740 GNUNET_SCHEDULER_cancel (t->rekey_task);
2742 rekey_tunnel (t, NULL);
2747 if (CADET_TUNNEL_READY == cstate
2748 && CONNECTIONS_PER_TUNNEL <= GCT_count_connections (t))
2750 LOG (GNUNET_ERROR_TYPE_DEBUG, " cstate triggered stop dht\n");
2751 GCP_stop_search (t->peer);
2757 * Change the tunnel encryption state.
2759 * @param t Tunnel whose encryption state to change, or NULL.
2760 * @param state New encryption state.
2763 GCT_change_estate (struct CadetTunnel* t, enum CadetTunnelEState state)
2765 enum CadetTunnelEState old;
2772 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel %s estate was %s\n",
2773 GCP_2s (t->peer), estate2s (old));
2774 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel %s estate is now %s\n",
2775 GCP_2s (t->peer), estate2s (t->estate));
2777 /* Send queued data if enc state changes to OK */
2778 if (myid != GCP_get_short_id (t->peer) &&
2779 CADET_TUNNEL_KEY_OK != old && CADET_TUNNEL_KEY_OK == t->estate)
2781 send_queued_data (t);
2787 * @brief Check if tunnel has too many connections, and remove one if necessary.
2789 * Currently this means the newest connection, unless it is a direct one.
2790 * Implemented as a task to avoid freeing a connection that is in the middle
2791 * of being created/processed.
2793 * @param cls Closure (Tunnel to check).
2794 * @param tc Task context.
2797 trim_connections (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
2799 struct CadetTunnel *t = cls;
2801 t->trim_connections_task = NULL;
2803 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
2806 if (GCT_count_connections (t) > 2 * CONNECTIONS_PER_TUNNEL)
2808 struct CadetTConnection *iter;
2809 struct CadetTConnection *c;
2811 for (c = iter = t->connection_head; NULL != iter; iter = iter->next)
2813 if ((iter->created.abs_value_us > c->created.abs_value_us)
2814 && GNUNET_NO == GCC_is_direct (iter->c))
2821 LOG (GNUNET_ERROR_TYPE_DEBUG, "Too many connections on tunnel %s\n",
2823 LOG (GNUNET_ERROR_TYPE_DEBUG, "Destroying connection %s\n",
2836 * Add a connection to a tunnel.
2839 * @param c Connection.
2842 GCT_add_connection (struct CadetTunnel *t, struct CadetConnection *c)
2844 struct CadetTConnection *aux;
2846 GNUNET_assert (NULL != c);
2848 LOG (GNUNET_ERROR_TYPE_DEBUG, "add connection %s\n", GCC_2s (c));
2849 LOG (GNUNET_ERROR_TYPE_DEBUG, " to tunnel %s\n", GCT_2s (t));
2850 for (aux = t->connection_head; aux != NULL; aux = aux->next)
2854 aux = GNUNET_new (struct CadetTConnection);
2856 aux->created = GNUNET_TIME_absolute_get ();
2858 GNUNET_CONTAINER_DLL_insert (t->connection_head, t->connection_tail, aux);
2860 if (CADET_TUNNEL_SEARCHING == t->cstate)
2861 GCT_change_estate (t, CADET_TUNNEL_WAITING);
2863 if (NULL != t->trim_connections_task)
2864 t->trim_connections_task = GNUNET_SCHEDULER_add_now (&trim_connections, t);
2869 * Remove a connection from a tunnel.
2872 * @param c Connection.
2875 GCT_remove_connection (struct CadetTunnel *t,
2876 struct CadetConnection *c)
2878 struct CadetTConnection *aux;
2879 struct CadetTConnection *next;
2882 LOG (GNUNET_ERROR_TYPE_DEBUG, "Removing connection %s from tunnel %s\n",
2883 GCC_2s (c), GCT_2s (t));
2884 for (aux = t->connection_head; aux != NULL; aux = next)
2889 GNUNET_CONTAINER_DLL_remove (t->connection_head, t->connection_tail, aux);
2894 conns = GCT_count_connections (t);
2896 && NULL == t->destroy_task
2897 && CADET_TUNNEL_SHUTDOWN != t->cstate
2898 && GNUNET_NO == shutting_down)
2900 if (0 == GCT_count_any_connections (t))
2901 GCT_change_cstate (t, CADET_TUNNEL_SEARCHING);
2903 GCT_change_cstate (t, CADET_TUNNEL_WAITING);
2906 /* Start new connections if needed */
2907 if (CONNECTIONS_PER_TUNNEL > conns
2908 && NULL == t->destroy_task
2909 && CADET_TUNNEL_SHUTDOWN != t->cstate
2910 && GNUNET_NO == shutting_down)
2912 LOG (GNUNET_ERROR_TYPE_DEBUG, " too few connections, getting new ones\n");
2913 GCP_connect (t->peer); /* Will change cstate to WAITING when possible */
2917 /* If not marked as ready, no change is needed */
2918 if (CADET_TUNNEL_READY != t->cstate)
2921 /* Check if any connection is ready to maintain cstate */
2922 for (aux = t->connection_head; aux != NULL; aux = aux->next)
2923 if (CADET_CONNECTION_READY == GCC_get_state (aux->c))
2929 * Add a channel to a tunnel.
2932 * @param ch Channel.
2935 GCT_add_channel (struct CadetTunnel *t, struct CadetChannel *ch)
2937 struct CadetTChannel *aux;
2939 GNUNET_assert (NULL != ch);
2941 LOG (GNUNET_ERROR_TYPE_DEBUG, "Adding channel %p to tunnel %p\n", ch, t);
2943 for (aux = t->channel_head; aux != NULL; aux = aux->next)
2945 LOG (GNUNET_ERROR_TYPE_DEBUG, " already there %p\n", aux->ch);
2950 aux = GNUNET_new (struct CadetTChannel);
2952 LOG (GNUNET_ERROR_TYPE_DEBUG, " adding %p to %p\n", aux, t->channel_head);
2953 GNUNET_CONTAINER_DLL_insert_tail (t->channel_head, t->channel_tail, aux);
2955 if (NULL != t->destroy_task)
2957 GNUNET_SCHEDULER_cancel (t->destroy_task);
2958 t->destroy_task = NULL;
2959 LOG (GNUNET_ERROR_TYPE_DEBUG, " undo destroy!\n");
2965 * Remove a channel from a tunnel.
2968 * @param ch Channel.
2971 GCT_remove_channel (struct CadetTunnel *t, struct CadetChannel *ch)
2973 struct CadetTChannel *aux;
2975 LOG (GNUNET_ERROR_TYPE_DEBUG, "Removing channel %p from tunnel %p\n", ch, t);
2976 for (aux = t->channel_head; aux != NULL; aux = aux->next)
2980 LOG (GNUNET_ERROR_TYPE_DEBUG, " found! %s\n", GCCH_2s (ch));
2981 GNUNET_CONTAINER_DLL_remove (t->channel_head, t->channel_tail, aux);
2990 * Search for a channel by global ID.
2992 * @param t Tunnel containing the channel.
2993 * @param chid Public channel number.
2995 * @return channel handler, NULL if doesn't exist
2997 struct CadetChannel *
2998 GCT_get_channel (struct CadetTunnel *t, CADET_ChannelNumber chid)
3000 struct CadetTChannel *iter;
3005 for (iter = t->channel_head; NULL != iter; iter = iter->next)
3007 if (GCCH_get_id (iter->ch) == chid)
3011 return NULL == iter ? NULL : iter->ch;
3016 * @brief Destroy a tunnel and free all resources.
3018 * Should only be called a while after the tunnel has been marked as destroyed,
3019 * in case there is a new channel added to the same peer shortly after marking
3020 * the tunnel. This way we avoid a new public key handshake.
3022 * @param cls Closure (tunnel to destroy).
3023 * @param tc Task context.
3026 delayed_destroy (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
3028 struct CadetTunnel *t = cls;
3029 struct CadetTConnection *iter;
3031 LOG (GNUNET_ERROR_TYPE_DEBUG, "delayed destroying tunnel %p\n", t);
3032 if (0 != (GNUNET_SCHEDULER_REASON_SHUTDOWN & tc->reason))
3034 LOG (GNUNET_ERROR_TYPE_WARNING,
3035 "Not destroying tunnel, due to shutdown. "
3036 "Tunnel at %p should have been freed by GCT_shutdown\n", t);
3039 t->destroy_task = NULL;
3040 t->cstate = CADET_TUNNEL_SHUTDOWN;
3042 for (iter = t->connection_head; NULL != iter; iter = iter->next)
3044 GCC_send_destroy (iter->c);
3051 * Tunnel is empty: destroy it.
3053 * Notifies all connections about the destruction.
3055 * @param t Tunnel to destroy.
3058 GCT_destroy_empty (struct CadetTunnel *t)
3060 if (GNUNET_YES == shutting_down)
3061 return; /* Will be destroyed immediately anyway */
3063 if (NULL != t->destroy_task)
3065 LOG (GNUNET_ERROR_TYPE_WARNING,
3066 "Tunnel %s is already scheduled for destruction. Tunnel debug dump:\n",
3068 GCT_debug (t, GNUNET_ERROR_TYPE_WARNING);
3070 /* should never happen, tunnel can only become empty once, and the
3071 * task identifier should be NO_TASK (cleaned when the tunnel was created
3072 * or became un-empty)
3077 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel %s empty: scheduling destruction\n",
3080 // FIXME make delay a config option
3081 t->destroy_task = GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_MINUTES,
3082 &delayed_destroy, t);
3083 LOG (GNUNET_ERROR_TYPE_DEBUG, "Scheduled destroy of %p as %llu\n",
3084 t, t->destroy_task);
3089 * Destroy tunnel if empty (no more channels).
3091 * @param t Tunnel to destroy if empty.
3094 GCT_destroy_if_empty (struct CadetTunnel *t)
3096 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel %s destroy if empty\n", GCT_2s (t));
3097 if (0 < GCT_count_channels (t))
3100 GCT_destroy_empty (t);
3105 * Destroy the tunnel.
3107 * This function does not generate any warning traffic to clients or peers.
3110 * Cancel messages belonging to this tunnel queued to neighbors.
3111 * Free any allocated resources linked to the tunnel.
3113 * @param t The tunnel to destroy.
3116 GCT_destroy (struct CadetTunnel *t)
3118 struct CadetTConnection *iter_c;
3119 struct CadetTConnection *next_c;
3120 struct CadetTChannel *iter_ch;
3121 struct CadetTChannel *next_ch;
3126 LOG (GNUNET_ERROR_TYPE_DEBUG, "destroying tunnel %s\n", GCP_2s (t->peer));
3128 GNUNET_break (GNUNET_YES ==
3129 GNUNET_CONTAINER_multipeermap_remove (tunnels,
3130 GCP_get_id (t->peer), t));
3132 for (iter_c = t->connection_head; NULL != iter_c; iter_c = next_c)
3134 next_c = iter_c->next;
3135 GCC_destroy (iter_c->c);
3137 for (iter_ch = t->channel_head; NULL != iter_ch; iter_ch = next_ch)
3139 next_ch = iter_ch->next;
3140 GCCH_destroy (iter_ch->ch);
3141 /* Should only happen on shutdown, but it's ok. */
3144 if (NULL != t->destroy_task)
3146 LOG (GNUNET_ERROR_TYPE_DEBUG, "cancelling dest: %llX\n", t->destroy_task);
3147 GNUNET_SCHEDULER_cancel (t->destroy_task);
3148 t->destroy_task = NULL;
3151 if (NULL != t->trim_connections_task)
3153 LOG (GNUNET_ERROR_TYPE_DEBUG, "cancelling trim: %llX\n",
3154 t->trim_connections_task);
3155 GNUNET_SCHEDULER_cancel (t->trim_connections_task);
3156 t->trim_connections_task = NULL;
3159 GNUNET_STATISTICS_update (stats, "# tunnels", -1, GNUNET_NO);
3160 GCP_set_tunnel (t->peer, NULL);
3162 if (NULL != t->rekey_task)
3164 GNUNET_SCHEDULER_cancel (t->rekey_task);
3165 t->rekey_task = NULL;
3167 if (NULL != t->kx_ctx)
3169 if (NULL != t->kx_ctx->finish_task)
3170 GNUNET_SCHEDULER_cancel (t->kx_ctx->finish_task);
3171 GNUNET_free (t->kx_ctx);
3182 * @brief Use the given path for the tunnel.
3183 * Update the next and prev hops (and RCs).
3184 * (Re)start the path refresh in case the tunnel is locally owned.
3186 * @param t Tunnel to update.
3187 * @param p Path to use.
3189 * @return Connection created.
3191 struct CadetConnection *
3192 GCT_use_path (struct CadetTunnel *t, struct CadetPeerPath *p)
3194 struct CadetConnection *c;
3195 struct GNUNET_CADET_Hash cid;
3196 unsigned int own_pos;
3198 if (NULL == t || NULL == p)
3204 if (CADET_TUNNEL_SHUTDOWN == t->cstate)
3210 for (own_pos = 0; own_pos < p->length; own_pos++)
3212 if (p->peers[own_pos] == myid)
3215 if (own_pos >= p->length)
3217 GNUNET_break_op (0);
3221 GNUNET_CRYPTO_random_block (GNUNET_CRYPTO_QUALITY_NONCE, &cid, sizeof (cid));
3222 c = GCC_new (&cid, t, p, own_pos);
3225 /* Path was flawed */
3228 GCT_add_connection (t, c);
3234 * Count all created connections of a tunnel. Not necessarily ready connections!
3236 * @param t Tunnel on which to count.
3238 * @return Number of connections created, either being established or ready.
3241 GCT_count_any_connections (struct CadetTunnel *t)
3243 struct CadetTConnection *iter;
3249 for (count = 0, iter = t->connection_head; NULL != iter; iter = iter->next)
3257 * Count established (ready) connections of a tunnel.
3259 * @param t Tunnel on which to count.
3261 * @return Number of connections.
3264 GCT_count_connections (struct CadetTunnel *t)
3266 struct CadetTConnection *iter;
3272 for (count = 0, iter = t->connection_head; NULL != iter; iter = iter->next)
3273 if (CADET_CONNECTION_READY == GCC_get_state (iter->c))
3281 * Count channels of a tunnel.
3283 * @param t Tunnel on which to count.
3285 * @return Number of channels.
3288 GCT_count_channels (struct CadetTunnel *t)
3290 struct CadetTChannel *iter;
3293 for (count = 0, iter = t->channel_head;
3295 iter = iter->next, count++) /* skip */;
3302 * Get the connectivity state of a tunnel.
3306 * @return Tunnel's connectivity state.
3308 enum CadetTunnelCState
3309 GCT_get_cstate (struct CadetTunnel *t)
3314 return (enum CadetTunnelCState) -1;
3321 * Get the encryption state of a tunnel.
3325 * @return Tunnel's encryption state.
3327 enum CadetTunnelEState
3328 GCT_get_estate (struct CadetTunnel *t)
3333 return (enum CadetTunnelEState) -1;
3339 * Get the maximum buffer space for a tunnel towards a local client.
3343 * @return Biggest buffer space offered by any channel in the tunnel.
3346 GCT_get_channels_buffer (struct CadetTunnel *t)
3348 struct CadetTChannel *iter;
3349 unsigned int buffer;
3350 unsigned int ch_buf;
3352 if (NULL == t->channel_head)
3354 /* Probably getting buffer for a channel create/handshake. */
3355 LOG (GNUNET_ERROR_TYPE_DEBUG, " no channels, allow max\n");
3360 for (iter = t->channel_head; NULL != iter; iter = iter->next)
3362 ch_buf = get_channel_buffer (iter);
3363 if (ch_buf > buffer)
3371 * Get the total buffer space for a tunnel for P2P traffic.
3375 * @return Buffer space offered by all connections in the tunnel.
3378 GCT_get_connections_buffer (struct CadetTunnel *t)
3380 struct CadetTConnection *iter;
3381 unsigned int buffer;
3383 if (GNUNET_NO == is_ready (t))
3385 if (count_queued_data (t) > 3)
3392 for (iter = t->connection_head; NULL != iter; iter = iter->next)
3394 if (GCC_get_state (iter->c) != CADET_CONNECTION_READY)
3398 buffer += get_connection_buffer (iter);
3406 * Get the tunnel's destination.
3410 * @return ID of the destination peer.
3412 const struct GNUNET_PeerIdentity *
3413 GCT_get_destination (struct CadetTunnel *t)
3415 return GCP_get_id (t->peer);
3420 * Get the tunnel's next free global channel ID.
3424 * @return GID of a channel free to use.
3427 GCT_get_next_chid (struct CadetTunnel *t)
3429 CADET_ChannelNumber chid;
3430 CADET_ChannelNumber mask;
3433 /* Set bit 30 depending on the ID relationship. Bit 31 is always 0 for GID.
3434 * If our ID is bigger or loopback tunnel, start at 0, bit 30 = 0
3435 * If peer's ID is bigger, start at 0x4... bit 30 = 1
3437 result = GNUNET_CRYPTO_cmp_peer_identity (&my_full_id, GCP_get_id (t->peer));
3442 t->next_chid |= mask;
3444 while (NULL != GCT_get_channel (t, t->next_chid))
3446 LOG (GNUNET_ERROR_TYPE_DEBUG, "Channel %u exists...\n", t->next_chid);
3447 t->next_chid = (t->next_chid + 1) & ~GNUNET_CADET_LOCAL_CHANNEL_ID_CLI;
3448 t->next_chid |= mask;
3450 chid = t->next_chid;
3451 t->next_chid = (t->next_chid + 1) & ~GNUNET_CADET_LOCAL_CHANNEL_ID_CLI;
3452 t->next_chid |= mask;
3459 * Send ACK on one or more channels due to buffer in connections.
3461 * @param t Channel which has some free buffer space.
3464 GCT_unchoke_channels (struct CadetTunnel *t)
3466 struct CadetTChannel *iter;
3467 unsigned int buffer;
3468 unsigned int channels = GCT_count_channels (t);
3469 unsigned int choked_n;
3470 struct CadetChannel *choked[channels];
3472 LOG (GNUNET_ERROR_TYPE_DEBUG, "GCT_unchoke_channels on %s\n", GCT_2s (t));
3473 LOG (GNUNET_ERROR_TYPE_DEBUG, " head: %p\n", t->channel_head);
3474 if (NULL != t->channel_head)
3475 LOG (GNUNET_ERROR_TYPE_DEBUG, " head ch: %p\n", t->channel_head->ch);
3477 /* Get buffer space */
3478 buffer = GCT_get_connections_buffer (t);
3484 /* Count and remember choked channels */
3486 for (iter = t->channel_head; NULL != iter; iter = iter->next)
3488 if (GNUNET_NO == get_channel_allowed (iter))
3490 choked[choked_n++] = iter->ch;
3494 /* Unchoke random channels */
3495 while (0 < buffer && 0 < choked_n)
3497 unsigned int r = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK,
3499 GCCH_allow_client (choked[r], GCCH_is_origin (choked[r], GNUNET_YES));
3502 choked[r] = choked[choked_n];
3508 * Send ACK on one or more connections due to buffer space to the client.
3510 * Iterates all connections of the tunnel and sends ACKs appropriately.
3515 GCT_send_connection_acks (struct CadetTunnel *t)
3517 struct CadetTConnection *iter;
3520 uint32_t allow_per_connection;
3522 unsigned int buffer;
3524 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel send connection ACKs on %s\n",
3533 if (CADET_TUNNEL_READY != t->cstate)
3536 buffer = GCT_get_channels_buffer (t);
3537 LOG (GNUNET_ERROR_TYPE_DEBUG, " buffer %u\n", buffer);
3539 /* Count connections, how many messages are already allowed */
3540 cs = GCT_count_connections (t);
3541 for (allowed = 0, iter = t->connection_head; NULL != iter; iter = iter->next)
3543 allowed += get_connection_allowed (iter);
3545 LOG (GNUNET_ERROR_TYPE_DEBUG, " allowed %u\n", allowed);
3547 /* Make sure there is no overflow */
3548 if (allowed > buffer)
3551 /* Authorize connections to send more data */
3552 to_allow = buffer - allowed;
3554 for (iter = t->connection_head;
3555 NULL != iter && to_allow > 0;
3558 if (CADET_CONNECTION_READY != GCC_get_state (iter->c)
3559 || get_connection_allowed (iter) > 64 / 3)
3563 allow_per_connection = to_allow/cs;
3564 to_allow -= allow_per_connection;
3566 GCC_allow (iter->c, allow_per_connection,
3567 GCC_is_origin (iter->c, GNUNET_NO));
3572 /* Since we don't allow if it's allowed to send 64/3, this can happen. */
3573 LOG (GNUNET_ERROR_TYPE_DEBUG, " reminding to_allow: %u\n", to_allow);
3579 * Cancel a previously sent message while it's in the queue.
3581 * ONLY can be called before the continuation given to the send function
3582 * is called. Once the continuation is called, the message is no longer in the
3585 * @param q Handle to the queue.
3588 GCT_cancel (struct CadetTunnelQueue *q)
3593 /* tun_message_sent() will be called and free q */
3595 else if (NULL != q->tqd)
3597 unqueue_data (q->tqd);
3599 if (NULL != q->cont)
3600 q->cont (q->cont_cls, NULL, q, 0, 0);
3611 * Sends an already built message on a tunnel, encrypting it and
3612 * choosing the best connection if not provided.
3614 * @param message Message to send. Function modifies it.
3615 * @param t Tunnel on which this message is transmitted.
3616 * @param c Connection to use (autoselect if NULL).
3617 * @param force Force the tunnel to take the message (buffer overfill).
3618 * @param cont Continuation to call once message is really sent.
3619 * @param cont_cls Closure for @c cont.
3621 * @return Handle to cancel message. NULL if @c cont is NULL.
3623 struct CadetTunnelQueue *
3624 GCT_send_prebuilt_message (const struct GNUNET_MessageHeader *message,
3625 struct CadetTunnel *t, struct CadetConnection *c,
3626 int force, GCT_sent cont, void *cont_cls)
3628 return send_prebuilt_message (message, t, c, force, cont, cont_cls, NULL);
3633 * Send an Axolotl KX message.
3635 * @param t Tunnel on which to send it.
3638 GCT_send_ax_kx (struct CadetTunnel *t)
3640 struct GNUNET_CADET_AX_KX msg;
3641 struct CadetConnection *c;
3643 LOG (GNUNET_ERROR_TYPE_INFO, "===> AX_KX for %s\n", GCT_2s (t));
3645 msg.header.size = sizeof (msg);
3646 msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_AX_KX);
3647 GNUNET_CRYPTO_ecdhe_key_get_public (t->ax->kx_0, &msg.ephemeral_key);
3648 GNUNET_CRYPTO_ecdhe_key_get_public (t->ax->DHRs, &msg.ratchet_key);
3650 c = tunnel_get_connection (t);
3651 /* TODO: save queue */
3652 GCC_send_prebuilt_message (&msg.header, GNUNET_MESSAGE_TYPE_CADET_AX_KX, 0,
3653 c, GCC_is_origin (c, GNUNET_YES), GNUNET_NO,
3659 * Sends an already built and encrypted message on a tunnel, choosing the best
3660 * connection. Useful for re-queueing messages queued on a destroyed connection.
3662 * @param message Message to send. Function modifies it.
3663 * @param t Tunnel on which this message is transmitted.
3666 GCT_resend_message (const struct GNUNET_MessageHeader *message,
3667 struct CadetTunnel *t)
3669 struct CadetConnection *c;
3672 c = tunnel_get_connection (t);
3675 /* TODO queue in tunnel, marked as encrypted */
3676 LOG (GNUNET_ERROR_TYPE_DEBUG, "No connection available, dropping.\n");
3679 fwd = GCC_is_origin (c, GNUNET_YES);
3680 GNUNET_break (NULL == GCC_send_prebuilt_message (message, 0, 0, c, fwd,
3681 GNUNET_YES, NULL, NULL));
3686 * Is the tunnel directed towards the local peer?
3690 * @return #GNUNET_YES if it is loopback.
3693 GCT_is_loopback (const struct CadetTunnel *t)
3695 return (myid == GCP_get_short_id (t->peer));
3700 * Is the tunnel this path already?
3705 * @return #GNUNET_YES a connection uses this path.
3708 GCT_is_path_used (const struct CadetTunnel *t, const struct CadetPeerPath *p)
3710 struct CadetTConnection *iter;
3712 for (iter = t->connection_head; NULL != iter; iter = iter->next)
3713 if (path_equivalent (GCC_get_path (iter->c), p))
3721 * Get a cost of a path for a tunnel considering existing connections.
3724 * @param path Candidate path.
3726 * @return Cost of the path (path length + number of overlapping nodes)
3729 GCT_get_path_cost (const struct CadetTunnel *t,
3730 const struct CadetPeerPath *path)
3732 struct CadetTConnection *iter;
3733 const struct CadetPeerPath *aux;
3734 unsigned int overlap;
3742 GNUNET_assert (NULL != t);
3744 for (i = 0; i < path->length; i++)
3746 for (iter = t->connection_head; NULL != iter; iter = iter->next)
3748 aux = GCC_get_path (iter->c);
3752 for (j = 0; j < aux->length; j++)
3754 if (path->peers[i] == aux->peers[j])
3762 return path->length + overlap;
3767 * Get the static string for the peer this tunnel is directed.
3771 * @return Static string the destination peer's ID.
3774 GCT_2s (const struct CadetTunnel *t)
3779 return GCP_2s (t->peer);
3783 /******************************************************************************/
3784 /***************************** INFO/DEBUG *******************************/
3785 /******************************************************************************/
3788 * Log all possible info about the tunnel state.
3790 * @param t Tunnel to debug.
3791 * @param level Debug level to use.
3794 GCT_debug (const struct CadetTunnel *t, enum GNUNET_ErrorType level)
3796 struct CadetTChannel *iterch;
3797 struct CadetTConnection *iterc;
3800 do_log = GNUNET_get_log_call_status (level & (~GNUNET_ERROR_TYPE_BULK),
3802 __FILE__, __FUNCTION__, __LINE__);
3806 LOG2 (level, "TTT DEBUG TUNNEL TOWARDS %s\n", GCT_2s (t));
3807 LOG2 (level, "TTT cstate %s, estate %s\n",
3808 cstate2s (t->cstate), estate2s (t->estate));
3809 LOG2 (level, "TTT kx_ctx %p, rekey_task %u, finish task %u\n",
3810 t->kx_ctx, t->rekey_task, t->kx_ctx ? t->kx_ctx->finish_task : 0);
3811 #if DUMP_KEYS_TO_STDERR
3812 LOG2 (level, "TTT my EPHM\t %s\n",
3813 GNUNET_h2s ((struct GNUNET_HashCode *) &kx_msg.ephemeral_key));
3814 LOG2 (level, "TTT peers EPHM:\t %s\n",
3815 GNUNET_h2s ((struct GNUNET_HashCode *) &t->peers_ephemeral_key));
3816 LOG2 (level, "TTT ENC key:\t %s\n",
3817 GNUNET_h2s ((struct GNUNET_HashCode *) &t->e_key));
3818 LOG2 (level, "TTT DEC key:\t %s\n",
3819 GNUNET_h2s ((struct GNUNET_HashCode *) &t->d_key));
3822 LOG2 (level, "TTT OLD ENC key:\t %s\n",
3823 GNUNET_h2s ((struct GNUNET_HashCode *) &t->kx_ctx->e_key_old));
3824 LOG2 (level, "TTT OLD DEC key:\t %s\n",
3825 GNUNET_h2s ((struct GNUNET_HashCode *) &t->kx_ctx->d_key_old));
3828 LOG2 (level, "TTT tq_head %p, tq_tail %p\n", t->tq_head, t->tq_tail);
3829 LOG2 (level, "TTT destroy %u\n", t->destroy_task);
3831 LOG2 (level, "TTT channels:\n");
3832 for (iterch = t->channel_head; NULL != iterch; iterch = iterch->next)
3834 LOG2 (level, "TTT - %s\n", GCCH_2s (iterch->ch));
3837 LOG2 (level, "TTT connections:\n");
3838 for (iterc = t->connection_head; NULL != iterc; iterc = iterc->next)
3840 GCC_debug (iterc->c, level);
3843 LOG2 (level, "TTT DEBUG TUNNEL END\n");
3848 * Iterate all tunnels.
3850 * @param iter Iterator.
3851 * @param cls Closure for @c iter.
3854 GCT_iterate_all (GNUNET_CONTAINER_PeerMapIterator iter, void *cls)
3856 GNUNET_CONTAINER_multipeermap_iterate (tunnels, iter, cls);
3861 * Count all tunnels.
3863 * @return Number of tunnels to remote peers kept by this peer.
3866 GCT_count_all (void)
3868 return GNUNET_CONTAINER_multipeermap_size (tunnels);
3873 * Iterate all connections of a tunnel.
3875 * @param t Tunnel whose connections to iterate.
3876 * @param iter Iterator.
3877 * @param cls Closure for @c iter.
3880 GCT_iterate_connections (struct CadetTunnel *t, GCT_conn_iter iter, void *cls)
3882 struct CadetTConnection *ct;
3884 for (ct = t->connection_head; NULL != ct; ct = ct->next)
3890 * Iterate all channels of a tunnel.
3892 * @param t Tunnel whose channels to iterate.
3893 * @param iter Iterator.
3894 * @param cls Closure for @c iter.
3897 GCT_iterate_channels (struct CadetTunnel *t, GCT_chan_iter iter, void *cls)
3899 struct CadetTChannel *cht;
3901 for (cht = t->channel_head; NULL != cht; cht = cht->next)
3902 iter (cls, cht->ch);