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 #define MAX_SKIPPED_KEYS 64
47 #define MAX_KEY_GAP 256
48 #define AX_HEADER_SIZE (sizeof (uint32_t) * 2\
49 + sizeof (struct GNUNET_CRYPTO_EcdhePublicKey))
52 /******************************************************************************/
53 /******************************** STRUCTS **********************************/
54 /******************************************************************************/
58 struct CadetTChannel *next;
59 struct CadetTChannel *prev;
60 struct CadetChannel *ch;
65 * Connection list and metadata.
67 struct CadetTConnection
72 struct CadetTConnection *next;
77 struct CadetTConnection *prev;
82 struct CadetConnection *c;
85 * Creation time, to keep oldest connection alive.
87 struct GNUNET_TIME_Absolute created;
90 * Connection throughput, to keep fastest connection alive.
96 * Structure used during a Key eXchange.
98 struct CadetTunnelKXCtx
101 * Encryption ("our") old "confirmed" key, for encrypting traffic sent by us
102 * end before the key exchange is finished or times out.
104 struct GNUNET_CRYPTO_SymmetricSessionKey e_key_old;
107 * Decryption ("their") old "confirmed" key, for decrypting traffic sent by
108 * the other end before the key exchange started.
110 struct GNUNET_CRYPTO_SymmetricSessionKey d_key_old;
113 * Same as @c e_key_old, for the case of two simultaneous KX.
114 * This can happen if cadet decides to start a re-key while the peer has also
115 * started its re-key (due to network delay this is impossible to avoid).
116 * In this case, the key material generated with the peer's old ephemeral
117 * *might* (but doesn't have to) be incorrect.
118 * Since no more than two re-keys can happen simultaneously, this is enough.
120 struct GNUNET_CRYPTO_SymmetricSessionKey e_key_old2;
123 * Same as @c d_key_old, for the case described in @c e_key_old2.
125 struct GNUNET_CRYPTO_SymmetricSessionKey d_key_old2;
128 * Challenge to send and expect in the PONG.
133 * When the rekey started. One minute after this the new key will be used.
135 struct GNUNET_TIME_Absolute rekey_start_time;
138 * Task for delayed destruction of the Key eXchange context, to allow delayed
139 * messages with the old key to be decrypted successfully.
141 struct GNUNET_SCHEDULER_Task *finish_task;
145 * Encryption systems possible.
147 enum CadetTunnelEncryption
150 * Default Axolotl system.
155 * Fallback OTR-style encryption.
161 * Struct to old keys for skipped messages while advancing the Axolotl ratchet.
163 struct CadetTunnelSkippedKey
168 struct CadetTunnelSkippedKey *next;
173 struct CadetTunnelSkippedKey *prev;
176 * When was this key stored (for timeout).
178 struct GNUNET_TIME_Absolute timestamp;
183 struct GNUNET_CRYPTO_SymmetricSessionKey HK;
188 struct GNUNET_CRYPTO_SymmetricSessionKey MK;
192 * Axolotl data, according to @url https://github.com/trevp/axolotl/wiki .
194 struct CadetTunnelAxolotl
197 * A (double linked) list of stored message keys and associated header keys
198 * for "skipped" messages, i.e. messages that have not been
199 * received despite the reception of more recent messages, (head).
201 struct CadetTunnelSkippedKey *skipped_head;
204 * Skipped messages' keys DLL, tail.
206 struct CadetTunnelSkippedKey *skipped_tail;
209 * Elements in @a skipped_head <-> @a skipped_tail.
211 unsigned int skipped;
214 * 32-byte root key which gets updated by DH ratchet.
216 struct GNUNET_CRYPTO_SymmetricSessionKey RK;
219 * 32-byte header key (send).
221 struct GNUNET_CRYPTO_SymmetricSessionKey HKs;
224 * 32-byte header key (recv)
226 struct GNUNET_CRYPTO_SymmetricSessionKey HKr;
229 * 32-byte next header key (send).
231 struct GNUNET_CRYPTO_SymmetricSessionKey NHKs;
234 * 32-byte next header key (recv).
236 struct GNUNET_CRYPTO_SymmetricSessionKey NHKr;
239 * 32-byte chain keys (used for forward-secrecy updating, send).
241 struct GNUNET_CRYPTO_SymmetricSessionKey CKs;
244 * 32-byte chain keys (used for forward-secrecy updating, recv).
246 struct GNUNET_CRYPTO_SymmetricSessionKey CKr;
249 * ECDH for key exchange (A0 / B0).
251 struct GNUNET_CRYPTO_EcdhePrivateKey *kx_0;
254 * ECDH Identity key (recv).
256 struct GNUNET_CRYPTO_EcdhePublicKey DHIr;
259 * ECDH Ratchet key (send).
261 struct GNUNET_CRYPTO_EcdhePrivateKey *DHRs;
264 * ECDH Ratchet key (recv).
266 struct GNUNET_CRYPTO_EcdhePublicKey DHRr;
269 * Message number (reset to 0 with each new ratchet, next message to send).
274 * Message number (reset to 0 with each new ratchet, next message to recv).
279 * Previous message numbers (# of msgs sent under prev ratchet)
284 * True (#GNUNET_YES) if we have to send a new ratchet key in next msg.
289 * Number of messages recieved since our last ratchet advance.
290 * - If this counter = 0, we cannot send a new ratchet key in next msg.
291 * - If this counter > 0, we can (but don't yet have to) send a new key.
293 unsigned int ratchet_allowed;
296 * Number of messages recieved since our last ratchet advance.
297 * - If this counter = 0, we cannot send a new ratchet key in next msg.
298 * - If this counter > 0, we can (but don't yet have to) send a new key.
300 unsigned int ratchet_counter;
303 * When does this ratchet expire and a new one is triggered.
305 struct GNUNET_TIME_Absolute ratchet_expiration;
309 * Struct containing all information regarding a tunnel to a peer.
314 * Endpoint of the tunnel.
316 struct CadetPeer *peer;
319 * Type of encryption used in the tunnel.
321 enum CadetTunnelEncryption enc_type;
326 struct CadetTunnelAxolotl *ax;
329 * State of the tunnel connectivity.
331 enum CadetTunnelCState cstate;
334 * State of the tunnel encryption.
336 enum CadetTunnelEState estate;
339 * Key eXchange context.
341 struct CadetTunnelKXCtx *kx_ctx;
344 * Peer's ephemeral key, to recreate @c e_key and @c d_key when own ephemeral
347 struct GNUNET_CRYPTO_EcdhePublicKey peers_ephemeral_key;
350 * Encryption ("our") key. It is only "confirmed" if kx_ctx is NULL.
352 struct GNUNET_CRYPTO_SymmetricSessionKey e_key;
355 * Decryption ("their") key. It is only "confirmed" if kx_ctx is NULL.
357 struct GNUNET_CRYPTO_SymmetricSessionKey d_key;
360 * Task to start the rekey process.
362 struct GNUNET_SCHEDULER_Task * rekey_task;
365 * Paths that are actively used to reach the destination peer.
367 struct CadetTConnection *connection_head;
368 struct CadetTConnection *connection_tail;
371 * Next connection number.
376 * Channels inside this tunnel.
378 struct CadetTChannel *channel_head;
379 struct CadetTChannel *channel_tail;
382 * Channel ID for the next created channel.
384 CADET_ChannelNumber next_chid;
387 * Destroy flag: if true, destroy on last message.
389 struct GNUNET_SCHEDULER_Task * destroy_task;
392 * Queued messages, to transmit once tunnel gets connected.
394 struct CadetTunnelDelayed *tq_head;
395 struct CadetTunnelDelayed *tq_tail;
398 * Task to trim connections if too many are present.
400 struct GNUNET_SCHEDULER_Task * trim_connections_task;
403 * Ephemeral message in the queue (to avoid queueing more than one).
405 struct CadetConnectionQueue *ephm_h;
408 * Pong message in the queue.
410 struct CadetConnectionQueue *pong_h;
415 * Struct used to save messages in a non-ready tunnel to send once connected.
417 struct CadetTunnelDelayed
422 struct CadetTunnelDelayed *next;
423 struct CadetTunnelDelayed *prev;
428 struct CadetTunnel *t;
431 * Tunnel queue given to the channel to cancel request. Update on send_queued.
433 struct CadetTunnelQueue *tq;
438 /* struct GNUNET_MessageHeader *msg; */
443 * Handle for messages queued but not yet sent.
445 struct CadetTunnelQueue
448 * Connection queue handle, to cancel if necessary.
450 struct CadetConnectionQueue *cq;
453 * Handle in case message hasn't been given to a connection yet.
455 struct CadetTunnelDelayed *tqd;
458 * Continuation to call once sent.
463 * Closure for @c cont.
470 * Cached Axolotl key with signature.
472 struct CadetAxolotlSignedKey
475 * Information about what is being signed (@a permanent_key).
477 struct GNUNET_CRYPTO_EccSignaturePurpose purpose;
480 * Permanent public ECDH key.
482 struct GNUNET_CRYPTO_EcdhePublicKey permanent_key;
485 * An EdDSA signature of the permanent ECDH key with the Peer's ID key.
487 struct GNUNET_CRYPTO_EddsaSignature signature;
491 /******************************************************************************/
492 /******************************* GLOBALS ***********************************/
493 /******************************************************************************/
496 * Global handle to the statistics service.
498 extern struct GNUNET_STATISTICS_Handle *stats;
501 * Local peer own ID (memory efficient handle).
503 extern GNUNET_PEER_Id myid;
506 * Local peer own ID (full value).
508 extern struct GNUNET_PeerIdentity my_full_id;
512 * Don't try to recover tunnels if shutting down.
514 extern int shutting_down;
518 * Set of all tunnels, in order to trigger a new exchange on rekey.
519 * Indexed by peer's ID.
521 static struct GNUNET_CONTAINER_MultiPeerMap *tunnels;
524 * Default TTL for payload packets.
526 static unsigned long long default_ttl;
529 * Own Peer ID private key.
531 const static struct GNUNET_CRYPTO_EddsaPrivateKey *id_key;
534 /******************************** AXOLOTL ************************************/
536 static struct GNUNET_CRYPTO_EcdhePrivateKey *ax_key;
539 * Own Axolotl permanent public key (cache).
541 static struct CadetAxolotlSignedKey ax_identity;
544 * How many messages are needed to trigger a ratchet advance.
546 static unsigned long long ratchet_messages;
549 * How long until we trigger a ratched advance.
551 static struct GNUNET_TIME_Relative ratchet_time;
554 /******************************** OTR ***********************************/
557 * Own global OTR ephemeral private key.
559 static struct GNUNET_CRYPTO_EcdhePrivateKey *otr_ephemeral_key;
562 * Cached message used to perform a OTR key exchange.
564 static struct GNUNET_CADET_KX_Ephemeral otr_kx_msg;
567 * Task to generate a new OTR ephemeral key.
569 static struct GNUNET_SCHEDULER_Task *rekey_task;
574 static struct GNUNET_TIME_Relative rekey_period;
577 /******************************************************************************/
578 /******************************** STATIC ***********************************/
579 /******************************************************************************/
582 * Get string description for tunnel connectivity state.
584 * @param cs Tunnel state.
586 * @return String representation.
589 cstate2s (enum CadetTunnelCState cs)
595 case CADET_TUNNEL_NEW:
596 return "CADET_TUNNEL_NEW";
597 case CADET_TUNNEL_SEARCHING:
598 return "CADET_TUNNEL_SEARCHING";
599 case CADET_TUNNEL_WAITING:
600 return "CADET_TUNNEL_WAITING";
601 case CADET_TUNNEL_READY:
602 return "CADET_TUNNEL_READY";
603 case CADET_TUNNEL_SHUTDOWN:
604 return "CADET_TUNNEL_SHUTDOWN";
606 SPRINTF (buf, "%u (UNKNOWN STATE)", cs);
614 * Get string description for tunnel encryption state.
616 * @param es Tunnel state.
618 * @return String representation.
621 estate2s (enum CadetTunnelEState es)
627 case CADET_TUNNEL_KEY_UNINITIALIZED:
628 return "CADET_TUNNEL_KEY_UNINITIALIZED";
629 case CADET_TUNNEL_KEY_SENT:
630 return "CADET_TUNNEL_KEY_SENT";
631 case CADET_TUNNEL_KEY_PING:
632 return "CADET_TUNNEL_KEY_PING";
633 case CADET_TUNNEL_KEY_OK:
634 return "CADET_TUNNEL_KEY_OK";
635 case CADET_TUNNEL_KEY_REKEY:
636 return "CADET_TUNNEL_KEY_REKEY";
638 SPRINTF (buf, "%u (UNKNOWN STATE)", es);
646 * @brief Check if tunnel is ready to send traffic.
648 * Tunnel must be connected and with encryption correctly set up.
650 * @param t Tunnel to check.
652 * @return #GNUNET_YES if ready, #GNUNET_NO otherwise
655 is_ready (struct CadetTunnel *t)
659 GCT_debug (t, GNUNET_ERROR_TYPE_DEBUG);
660 ready = CADET_TUNNEL_READY == t->cstate
661 && (CADET_TUNNEL_KEY_OK == t->estate
662 || CADET_TUNNEL_KEY_REKEY == t->estate);
663 ready = ready || GCT_is_loopback (t);
669 * Check if a key is invalid (NULL pointer or all 0)
671 * @param key Key to check.
673 * @return #GNUNET_YES if key is null, #GNUNET_NO if exists and is not 0.
676 is_key_null (struct GNUNET_CRYPTO_SymmetricSessionKey *key)
678 struct GNUNET_CRYPTO_SymmetricSessionKey null_key;
683 memset (&null_key, 0, sizeof (null_key));
684 if (0 == memcmp (key, &null_key, sizeof (null_key)))
691 * Ephemeral key message purpose size.
693 * @return Size of the part of the ephemeral key message that must be signed.
696 ephemeral_purpose_size (void)
698 return sizeof (struct GNUNET_CRYPTO_EccSignaturePurpose) +
699 sizeof (struct GNUNET_TIME_AbsoluteNBO) +
700 sizeof (struct GNUNET_TIME_AbsoluteNBO) +
701 sizeof (struct GNUNET_CRYPTO_EcdhePublicKey) +
702 sizeof (struct GNUNET_PeerIdentity);
707 * Ephemeral key message purpose size.
709 * @return Size of the part of the ephemeral key message that must be signed.
712 ax_purpose_size (void)
714 return sizeof (struct GNUNET_CRYPTO_EccSignaturePurpose) +
715 sizeof (struct GNUNET_CRYPTO_EcdhePublicKey);
720 * Size of the encrypted part of a ping message.
722 * @return Size of the encrypted part of a ping message.
725 ping_encryption_size (void)
727 return sizeof (uint32_t);
732 * Get the channel's buffer. ONLY FOR NON-LOOPBACK CHANNELS!!
734 * @param tch Tunnel's channel handle.
736 * @return Amount of messages the channel can still buffer towards the client.
739 get_channel_buffer (const struct CadetTChannel *tch)
743 /* If channel is incoming, is terminal in the FWD direction and fwd is YES */
744 fwd = GCCH_is_terminal (tch->ch, GNUNET_YES);
746 return GCCH_get_buffer (tch->ch, fwd);
751 * Get the channel's allowance status.
753 * @param tch Tunnel's channel handle.
755 * @return #GNUNET_YES if we allowed the client to send data to us.
758 get_channel_allowed (const struct CadetTChannel *tch)
762 /* If channel is outgoing, is origin in the FWD direction and fwd is YES */
763 fwd = GCCH_is_origin (tch->ch, GNUNET_YES);
765 return GCCH_get_allowed (tch->ch, fwd);
770 * Get the connection's buffer.
772 * @param tc Tunnel's connection handle.
774 * @return Amount of messages the connection can still buffer.
777 get_connection_buffer (const struct CadetTConnection *tc)
781 /* If connection is outgoing, is origin in the FWD direction and fwd is YES */
782 fwd = GCC_is_origin (tc->c, GNUNET_YES);
784 return GCC_get_buffer (tc->c, fwd);
789 * Get the connection's allowance.
791 * @param tc Tunnel's connection handle.
793 * @return Amount of messages we have allowed the next peer to send us.
796 get_connection_allowed (const struct CadetTConnection *tc)
800 /* If connection is outgoing, is origin in the FWD direction and fwd is YES */
801 fwd = GCC_is_origin (tc->c, GNUNET_YES);
803 return GCC_get_allowed (tc->c, fwd);
808 * Check that a ephemeral key message s well formed and correctly signed.
810 * @param t Tunnel on which the message came.
811 * @param msg The ephemeral key message.
813 * @return GNUNET_OK if message is fine, GNUNET_SYSERR otherwise.
816 check_ephemeral (struct CadetTunnel *t,
817 const struct GNUNET_CADET_KX_Ephemeral *msg)
819 /* Check message size */
820 if (ntohs (msg->header.size) != sizeof (struct GNUNET_CADET_KX_Ephemeral))
821 return GNUNET_SYSERR;
823 /* Check signature size */
824 if (ntohl (msg->purpose.size) != ephemeral_purpose_size ())
825 return GNUNET_SYSERR;
828 if (0 != memcmp (&msg->origin_identity,
829 GCP_get_id (t->peer),
830 sizeof (struct GNUNET_PeerIdentity)))
831 return GNUNET_SYSERR;
833 /* Check signature */
835 GNUNET_CRYPTO_eddsa_verify (GNUNET_SIGNATURE_PURPOSE_CADET_KX,
838 &msg->origin_identity.public_key))
839 return GNUNET_SYSERR;
846 * Select the best key to use for encryption (send), based on KX status.
848 * Normally, return the current key. If there is a KX in progress and the old
849 * key is fresh enough, return the old key.
851 * @param t Tunnel to choose the key from.
853 * @return The optimal key to encrypt/hmac outgoing traffic.
855 static const struct GNUNET_CRYPTO_SymmetricSessionKey *
856 select_key (const struct CadetTunnel *t)
858 const struct GNUNET_CRYPTO_SymmetricSessionKey *key;
860 if (NULL != t->kx_ctx
861 && NULL == t->kx_ctx->finish_task)
863 struct GNUNET_TIME_Relative age;
865 age = GNUNET_TIME_absolute_get_duration (t->kx_ctx->rekey_start_time);
866 LOG (GNUNET_ERROR_TYPE_DEBUG,
867 " key exchange in progress, started %s ago\n",
868 GNUNET_STRINGS_relative_time_to_string (age, GNUNET_YES));
869 // FIXME make duration of old keys configurable
870 if (age.rel_value_us < GNUNET_TIME_UNIT_MINUTES.rel_value_us)
872 LOG (GNUNET_ERROR_TYPE_DEBUG, " using old key\n");
873 key = &t->kx_ctx->e_key_old;
877 LOG (GNUNET_ERROR_TYPE_DEBUG, " using new key (old key too old)\n");
883 LOG (GNUNET_ERROR_TYPE_DEBUG, " no KX: using current key\n");
893 * @param plaintext Content to HMAC.
894 * @param size Size of @c plaintext.
895 * @param iv Initialization vector for the message.
896 * @param key Key to use.
897 * @param hmac[out] Destination to store the HMAC.
900 t_hmac (const void *plaintext, size_t size,
901 uint32_t iv, const struct GNUNET_CRYPTO_SymmetricSessionKey *key,
902 struct GNUNET_CADET_Hash *hmac)
904 static const char ctx[] = "cadet authentication key";
905 struct GNUNET_CRYPTO_AuthKey auth_key;
906 struct GNUNET_HashCode hash;
908 #if DUMP_KEYS_TO_STDERR
909 LOG (GNUNET_ERROR_TYPE_INFO, " HMAC %u bytes with key %s\n", size,
910 GNUNET_h2s ((struct GNUNET_HashCode *) key));
912 GNUNET_CRYPTO_hmac_derive_key (&auth_key, key,
917 /* Two step: CADET_Hash is only 256 bits, HashCode is 512. */
918 GNUNET_CRYPTO_hmac (&auth_key, plaintext, size, &hash);
919 memcpy (hmac, &hash, sizeof (*hmac));
924 * Encrypt daforce_newest_keyta with the tunnel key.
926 * @param t Tunnel whose key to use.
927 * @param dst Destination for the encrypted data.
928 * @param src Source of the plaintext. Can overlap with @c dst.
929 * @param size Size of the plaintext.
930 * @param iv Initialization Vector to use.
931 * @param force_newest_key Force the use of the newest key, otherwise
932 * CADET will use the old key when allowed.
933 * This can happen in the case when a KX is going on
934 * and the old one hasn't expired.
937 t_encrypt (struct CadetTunnel *t, void *dst, const void *src,
938 size_t size, uint32_t iv, int force_newest_key)
940 struct GNUNET_CRYPTO_SymmetricInitializationVector siv;
941 const struct GNUNET_CRYPTO_SymmetricSessionKey *key;
944 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_encrypt start\n");
946 key = GNUNET_YES == force_newest_key ? &t->e_key : select_key (t);
947 #if DUMP_KEYS_TO_STDERR
948 LOG (GNUNET_ERROR_TYPE_INFO, " ENC with key %s\n",
949 GNUNET_h2s ((struct GNUNET_HashCode *) key));
951 GNUNET_CRYPTO_symmetric_derive_iv (&siv, key, &iv, sizeof (iv), NULL);
952 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_encrypt IV derived\n");
953 out_size = GNUNET_CRYPTO_symmetric_encrypt (src, size, key, &siv, dst);
954 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_encrypt end\n");
963 * @param key Key to use.
964 * @param hash[out] Resulting HMAC.
965 * @param source Source key material (data to HMAC).
966 * @param len Length of @a source.
969 t_ax_hmac_hash (struct GNUNET_CRYPTO_SymmetricSessionKey *key,
970 struct GNUNET_HashCode *hash,
971 void *source, unsigned int len)
973 static const char ctx[] = "axolotl HMAC-HASH";
974 struct GNUNET_CRYPTO_AuthKey auth_key;
976 GNUNET_CRYPTO_hmac_derive_key (&auth_key, key,
979 GNUNET_CRYPTO_hmac (&auth_key, source, len, hash);
984 * Derive a key from a HMAC-HASH.
986 * @param key Key to use for the HMAC.
987 * @param out Key to generate.
988 * @param source Source key material (data to HMAC).
989 * @param len Length of @a source.
992 t_hmac_derive_key (struct GNUNET_CRYPTO_SymmetricSessionKey *key,
993 struct GNUNET_CRYPTO_SymmetricSessionKey *out,
994 void *source, unsigned int len)
996 static const char ctx[] = "axolotl derive key";
997 struct GNUNET_HashCode h;
999 t_ax_hmac_hash (key, &h, source, len);
1000 GNUNET_CRYPTO_kdf (out, sizeof (*out), ctx, sizeof (ctx),
1001 &h, sizeof (h), NULL);
1006 * Encrypt data with the axolotl tunnel key.
1008 * @param t Tunnel whose key to use.
1009 * @param dst Destination for the encrypted data.
1010 * @param src Source of the plaintext. Can overlap with @c dst.
1011 * @param size Size of the plaintext.
1013 * @return Size of the encrypted data.
1016 t_ax_encrypt (struct CadetTunnel *t, void *dst, const void *src, size_t size)
1018 struct GNUNET_CRYPTO_SymmetricSessionKey MK;
1019 struct GNUNET_CRYPTO_SymmetricInitializationVector iv;
1020 struct CadetTunnelAxolotl *ax;
1023 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_ax_encrypt start\n");
1027 ax->ratchet_counter++;
1028 if (GNUNET_YES == ax->ratchet_allowed
1029 && (ratchet_messages <= ax->ratchet_counter
1030 || 0 == GNUNET_TIME_absolute_get_remaining (ax->ratchet_expiration).rel_value_us))
1032 ax->ratchet_flag = GNUNET_YES;
1035 if (GNUNET_YES == ax->ratchet_flag)
1037 /* Advance ratchet */
1038 struct GNUNET_CRYPTO_SymmetricSessionKey keys[3];
1039 struct GNUNET_HashCode dh;
1040 struct GNUNET_HashCode hmac;
1041 static const char ctx[] = "axolotl ratchet";
1043 ax->DHRs = GNUNET_CRYPTO_ecdhe_key_create ();
1046 /* RK, NHKs, CKs = KDF( HMAC-HASH(RK, DH(DHRs, DHRr)) ) */
1047 GNUNET_CRYPTO_ecc_ecdh (ax->DHRs, &ax->DHRr, &dh);
1048 t_ax_hmac_hash (&ax->RK, &hmac, &dh, sizeof (dh));
1049 GNUNET_CRYPTO_kdf (keys, sizeof (keys), ctx, sizeof (ctx),
1050 &hmac, sizeof (hmac), NULL);
1057 ax->ratchet_flag = GNUNET_NO;
1058 ax->ratchet_allowed = GNUNET_NO;
1059 ax->ratchet_counter = 0;
1060 ax->ratchet_expiration =
1061 GNUNET_TIME_absolute_add (GNUNET_TIME_absolute_get(), ratchet_time);
1064 t_hmac_derive_key (&ax->CKs, &MK, "0", 1);
1065 GNUNET_CRYPTO_symmetric_derive_iv (&iv, &MK, NULL, 0, NULL);
1067 #if DUMP_KEYS_TO_STDERR
1068 LOG (GNUNET_ERROR_TYPE_INFO, " CKs: %s\n",
1069 GNUNET_h2s ((struct GNUNET_HashCode *) &ax->CKs));
1070 LOG (GNUNET_ERROR_TYPE_INFO, " AX_ENC with key %u: %s\n", ax->Ns,
1071 GNUNET_h2s ((struct GNUNET_HashCode *) &MK));
1074 out_size = GNUNET_CRYPTO_symmetric_encrypt (src, size, &MK, &iv, dst);
1076 t_hmac_derive_key (&ax->CKs, &ax->CKs, "1", 1);
1078 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_ax_encrypt end\n");
1085 * Decrypt data with the axolotl tunnel key.
1087 * @param t Tunnel whose key to use.
1088 * @param dst Destination for the decrypted data.
1089 * @param src Source of the ciphertext. Can overlap with @c dst.
1090 * @param size Size of the ciphertext.
1092 * @return Size of the decrypted data.
1095 t_ax_decrypt (struct CadetTunnel *t, void *dst, const void *src, size_t size)
1097 struct GNUNET_CRYPTO_SymmetricSessionKey MK;
1098 struct GNUNET_CRYPTO_SymmetricInitializationVector iv;
1099 struct CadetTunnelAxolotl *ax;
1102 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_ax_decrypt start\n");
1106 t_hmac_derive_key (&ax->CKr, &MK, "0", 1);
1107 GNUNET_CRYPTO_symmetric_derive_iv (&iv, &MK, NULL, 0, NULL);
1109 #if DUMP_KEYS_TO_STDERR
1110 LOG (GNUNET_ERROR_TYPE_INFO, " CKr: %s\n",
1111 GNUNET_h2s ((struct GNUNET_HashCode *) &ax->CKr));
1112 LOG (GNUNET_ERROR_TYPE_INFO, " AX_DEC with key %u: %s\n", ax->Nr,
1113 GNUNET_h2s ((struct GNUNET_HashCode *) &MK));
1116 GNUNET_assert (size >= sizeof (struct GNUNET_MessageHeader));
1117 out_size = GNUNET_CRYPTO_symmetric_decrypt (src, size, &MK, &iv, dst);
1118 GNUNET_assert (out_size == size);
1120 t_hmac_derive_key (&ax->CKr, &ax->CKr, "1", 1);
1122 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_ax_decrypt end\n");
1129 * Encrypt header with the axolotl header key.
1131 * @param t Tunnel whose key to use.
1132 * @param msg Message whose header to encrypt.
1135 t_h_encrypt (struct CadetTunnel *t, struct GNUNET_CADET_AX *msg)
1137 struct GNUNET_CRYPTO_SymmetricInitializationVector iv;
1138 struct CadetTunnelAxolotl *ax;
1141 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_h_encrypt start\n");
1144 GNUNET_CRYPTO_symmetric_derive_iv (&iv, &ax->HKs, NULL, 0, NULL);
1146 #if DUMP_KEYS_TO_STDERR
1147 LOG (GNUNET_ERROR_TYPE_INFO, " AX_ENC_H with key %s\n",
1148 GNUNET_h2s ((struct GNUNET_HashCode *) &ax->HKs));
1151 out_size = GNUNET_CRYPTO_symmetric_encrypt (&msg->Ns, AX_HEADER_SIZE,
1152 &ax->HKs, &iv, &msg->Ns);
1154 GNUNET_assert (AX_HEADER_SIZE == out_size);
1156 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_ax_encrypt end\n");
1161 * Decrypt header with the current axolotl header key.
1163 * @param t Tunnel whose current ax HK to use.
1164 * @param src Message whose header to decrypt.
1165 * @param dst Where to decrypt header to.
1168 t_h_decrypt (struct CadetTunnel *t, const struct GNUNET_CADET_AX *src,
1169 struct GNUNET_CADET_AX *dst)
1171 struct GNUNET_CRYPTO_SymmetricInitializationVector iv;
1172 struct CadetTunnelAxolotl *ax;
1175 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_h_decrypt start\n");
1178 GNUNET_CRYPTO_symmetric_derive_iv (&iv, &ax->HKr, NULL, 0, NULL);
1180 #if DUMP_KEYS_TO_STDERR
1181 LOG (GNUNET_ERROR_TYPE_INFO, " AX_DEC_H with key %s\n",
1182 GNUNET_h2s ((struct GNUNET_HashCode *) &ax->HKr));
1185 out_size = GNUNET_CRYPTO_symmetric_decrypt (&src->Ns, AX_HEADER_SIZE,
1186 &ax->HKr, &iv, &dst->Ns);
1188 GNUNET_assert (AX_HEADER_SIZE == out_size);
1190 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_ax_decrypt end\n");
1195 * Decrypt and verify data with the appropriate tunnel key.
1197 * @param key Key to use.
1198 * @param dst Destination for the plaintext.
1199 * @param src Source of the encrypted data. Can overlap with @c dst.
1200 * @param size Size of the encrypted data.
1201 * @param iv Initialization Vector to use.
1203 * @return Size of the decrypted data, -1 if an error was encountered.
1206 decrypt (const struct GNUNET_CRYPTO_SymmetricSessionKey *key,
1207 void *dst, const void *src, size_t size, uint32_t iv)
1209 struct GNUNET_CRYPTO_SymmetricInitializationVector siv;
1212 LOG (GNUNET_ERROR_TYPE_DEBUG, " decrypt start\n");
1213 LOG (GNUNET_ERROR_TYPE_DEBUG, " decrypt iv\n");
1214 GNUNET_CRYPTO_symmetric_derive_iv (&siv, key, &iv, sizeof (iv), NULL);
1215 LOG (GNUNET_ERROR_TYPE_DEBUG, " decrypt iv done\n");
1216 out_size = GNUNET_CRYPTO_symmetric_decrypt (src, size, key, &siv, dst);
1217 LOG (GNUNET_ERROR_TYPE_DEBUG, " decrypt end\n");
1224 * Decrypt and verify data with the most recent tunnel key.
1226 * @param t Tunnel whose key to use.
1227 * @param dst Destination for the plaintext.
1228 * @param src Source of the encrypted data. Can overlap with @c dst.
1229 * @param size Size of the encrypted data.
1230 * @param iv Initialization Vector to use.
1232 * @return Size of the decrypted data, -1 if an error was encountered.
1235 t_decrypt (struct CadetTunnel *t, void *dst, const void *src,
1236 size_t size, uint32_t iv)
1240 #if DUMP_KEYS_TO_STDERR
1241 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_decrypt with %s\n",
1242 GNUNET_h2s ((struct GNUNET_HashCode *) &t->d_key));
1244 if (CADET_TUNNEL_KEY_UNINITIALIZED == t->estate)
1246 GNUNET_STATISTICS_update (stats, "# non decryptable data", 1, GNUNET_NO);
1247 LOG (GNUNET_ERROR_TYPE_WARNING,
1248 "got data on %s without a valid key\n",
1250 GCT_debug (t, GNUNET_ERROR_TYPE_WARNING);
1254 out_size = decrypt (&t->d_key, dst, src, size, iv);
1261 * Decrypt and verify data with the appropriate tunnel key and verify that the
1262 * data has not been altered since it was sent by the remote peer.
1264 * @param t Tunnel whose key to use.
1265 * @param dst Destination for the plaintext.
1266 * @param src Source of the encrypted data. Can overlap with @c dst.
1267 * @param size Size of the encrypted data.
1268 * @param iv Initialization Vector to use.
1269 * @param msg_hmac HMAC of the message, cannot be NULL.
1271 * @return Size of the decrypted data, -1 if an error was encountered.
1274 t_decrypt_and_validate (struct CadetTunnel *t,
1275 void *dst, const void *src,
1276 size_t size, uint32_t iv,
1277 const struct GNUNET_CADET_Hash *msg_hmac)
1279 struct GNUNET_CRYPTO_SymmetricSessionKey *key;
1280 struct GNUNET_CADET_Hash hmac;
1283 /* Try primary (newest) key */
1285 decrypted_size = decrypt (key, dst, src, size, iv);
1286 t_hmac (src, size, iv, key, &hmac);
1287 if (0 == memcmp (msg_hmac, &hmac, sizeof (hmac)))
1288 return decrypted_size;
1290 /* If no key exchange is going on, we just failed. */
1291 if (NULL == t->kx_ctx)
1293 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
1294 "Failed checksum validation on tunnel %s with no KX\n",
1296 GNUNET_STATISTICS_update (stats, "# wrong HMAC no KX", 1, GNUNET_NO);
1300 /* Try secondary key, from previous KX period. */
1301 key = &t->kx_ctx->d_key_old;
1302 decrypted_size = decrypt (key, dst, src, size, iv);
1303 t_hmac (src, size, iv, key, &hmac);
1304 if (0 == memcmp (msg_hmac, &hmac, sizeof (hmac)))
1305 return decrypted_size;
1307 /* Hail Mary, try tertiary, key, in case of parallel re-keys. */
1308 key = &t->kx_ctx->d_key_old2;
1309 decrypted_size = decrypt (key, dst, src, size, iv);
1310 t_hmac (src, size, iv, key, &hmac);
1311 if (0 == memcmp (msg_hmac, &hmac, sizeof (hmac)))
1312 return decrypted_size;
1314 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
1315 "Failed checksum validation on tunnel %s with KX\n",
1317 GNUNET_STATISTICS_update (stats, "# wrong HMAC with KX", 1, GNUNET_NO);
1323 * Decrypt and verify data with the appropriate tunnel key and verify that the
1324 * data has not been altered since it was sent by the remote peer.
1326 * @param t Tunnel whose key to use.
1327 * @param dst Destination for the plaintext.
1328 * @param src Source of the message. Can overlap with @c dst.
1329 * @param size Size of the message.
1331 * @return Size of the decrypted data, -1 if an error was encountered.
1334 try_old_ax_keys (struct CadetTunnel *t, struct GNUNET_CADET_AX *dst,
1335 const struct GNUNET_CADET_AX *src, size_t size)
1337 struct CadetTunnelSkippedKey *key;
1338 struct GNUNET_CADET_Hash hmac;
1339 struct GNUNET_CRYPTO_SymmetricInitializationVector iv;
1344 for (key = t->ax->skipped_head; NULL != key; key = key->next)
1346 t_hmac (&src->Ns, AX_HEADER_SIZE, 0, &key->HK, &hmac);
1347 if (0 != memcmp (&hmac, &src->hmac, sizeof (hmac)))
1353 #if DUMP_KEYS_TO_STDERR
1354 LOG (GNUNET_ERROR_TYPE_INFO, " AX_DEC with skipped key %s\n",
1355 GNUNET_h2s ((struct GNUNET_HashCode *) &key->MK));
1358 GNUNET_assert (size > sizeof (struct GNUNET_CADET_AX));
1359 len = size - sizeof (struct GNUNET_CADET_AX);
1360 GNUNET_CRYPTO_symmetric_derive_iv (&iv, &key->MK, NULL, 0, NULL);
1361 res = GNUNET_CRYPTO_symmetric_decrypt (&src[1], len, &key->MK, &iv, &dst[1]);
1363 GNUNET_CONTAINER_DLL_remove (t->ax->skipped_head, t->ax->skipped_tail, key);
1372 * Stage skipped AX keys and calculate the message key.
1374 * Stores each HK and MK for skipped messages.
1376 * @param t Tunnel where to stage the keys.
1377 * @param HKr Header key.
1378 * @param Nr Current message number.
1379 * @param Np Received meesage number.
1380 * @param CKr[in/out] Chain key, gets ratcheted forward to the new state.
1383 store_ax_keys (struct CadetTunnel *t,
1384 const struct GNUNET_CRYPTO_SymmetricSessionKey *HKr,
1385 uint32_t Nr, uint32_t Np,
1386 struct GNUNET_CRYPTO_SymmetricSessionKey *CKr)
1388 struct CadetTunnelSkippedKey *key;
1393 if (MAX_KEY_GAP < gap || 0 > gap)
1395 /* Avoid DoS (forcing peer to do 2*33 chain HMAC operations) */
1396 /* TODO: start new key exchange on return */
1397 GNUNET_break_op (0);
1401 for (i = Nr; i < Np; i++)
1403 key = GNUNET_new (struct CadetTunnelSkippedKey);
1404 key->timestamp = GNUNET_TIME_absolute_get ();
1405 t_hmac_derive_key (CKr, &key->MK, "0", 1);
1406 #if DUMP_KEYS_TO_STDERR
1407 LOG (GNUNET_ERROR_TYPE_INFO, " storing MK for Nr %u: %s\n",
1408 i, GNUNET_h2s ((struct GNUNET_HashCode *) &key->MK));
1409 LOG (GNUNET_ERROR_TYPE_INFO, " for CKr: %s\n",
1410 GNUNET_h2s ((struct GNUNET_HashCode *) &t->ax->CKr));
1412 t_hmac_derive_key (CKr, CKr, "1", 1);
1413 GNUNET_CONTAINER_DLL_insert (t->ax->skipped_head, t->ax->skipped_tail, key);
1420 * Decrypt and verify data with the appropriate tunnel key and verify that the
1421 * data has not been altered since it was sent by the remote peer.
1423 * @param t Tunnel whose key to use.
1424 * @param dst Destination for the plaintext.
1425 * @param src Source of the message. Can overlap with @c dst.
1426 * @param size Size of the message.
1428 * @return Size of the decrypted data, -1 if an error was encountered.
1431 t_ax_decrypt_and_validate (struct CadetTunnel *t, void *dst,
1432 const struct GNUNET_CADET_AX *src, size_t size)
1434 struct CadetTunnelAxolotl *ax;
1435 struct GNUNET_CADET_Hash msg_hmac;
1436 struct GNUNET_HashCode hmac;
1437 struct GNUNET_CADET_AX *dstmsg;
1445 esize = size - sizeof (struct GNUNET_CADET_AX);
1450 /* Try current HK */
1451 t_hmac (&src->Ns, AX_HEADER_SIZE + esize, 0, &ax->HKr, &msg_hmac);
1452 if (0 != memcmp (&msg_hmac, &src->hmac, sizeof (msg_hmac)))
1454 static const char ctx[] = "axolotl ratchet";
1455 struct GNUNET_CRYPTO_SymmetricSessionKey keys[3]; /* RKp, NHKp, CKp */
1456 struct GNUNET_CRYPTO_SymmetricSessionKey HK;
1457 struct GNUNET_HashCode dh;
1458 struct GNUNET_CRYPTO_EcdhePublicKey *DHRp;
1461 t_hmac (&src->Ns, AX_HEADER_SIZE + esize, 0, &ax->NHKr, &msg_hmac);
1462 if (0 != memcmp (&msg_hmac, &src->hmac, sizeof (msg_hmac)))
1464 /* Try the skipped keys, if that fails, we're out of luck. */
1465 return try_old_ax_keys (t, dst, src, size);
1467 LOG (GNUNET_ERROR_TYPE_INFO, "next HK\n");
1471 t_h_decrypt (t, src, dstmsg);
1472 Np = ntohl (dstmsg->Ns);
1473 PNp = ntohl (dstmsg->PNs);
1474 DHRp = &dstmsg->DHRs;
1475 store_ax_keys (t, &HK, ax->Nr, PNp, &ax->CKr);
1477 /* RKp, NHKp, CKp = KDF (HMAC-HASH (RK, DH (DHRp, DHRs))) */
1478 GNUNET_CRYPTO_ecc_ecdh (ax->DHRs, DHRp, &dh);
1479 t_ax_hmac_hash (&ax->RK, &hmac, &dh, sizeof (dh));
1480 GNUNET_CRYPTO_kdf (keys, sizeof (keys), ctx, sizeof (ctx),
1481 &hmac, sizeof (hmac), NULL);
1483 /* Commit "purported" keys */
1489 ax->ratchet_allowed = GNUNET_YES;
1493 LOG (GNUNET_ERROR_TYPE_DEBUG, "current HK\n");
1494 t_h_decrypt (t, src, dstmsg);
1495 Np = ntohl (dstmsg->Ns);
1496 PNp = ntohl (dstmsg->PNs);
1500 store_ax_keys (t, &ax->HKr, ax->Nr, Np, &ax->CKr);
1504 osize = t_ax_decrypt (t, dst, &src[1], esize);
1507 GNUNET_break_op (0);
1516 * Create key material by doing ECDH on the local and remote ephemeral keys.
1518 * @param key_material Where to store the key material.
1519 * @param ephemeral Peer's public ephemeral key.
1521 * @return GNUNET_OK if it went fine, GNUNET_SYSERR otherwise.
1524 derive_otr_key_material (struct GNUNET_HashCode *key_material,
1525 const struct GNUNET_CRYPTO_EcdhePublicKey *ephemeral)
1528 GNUNET_CRYPTO_ecc_ecdh (otr_ephemeral_key, ephemeral, key_material))
1531 return GNUNET_SYSERR;
1538 * Create a symmetic key from the identities of both ends and the key material
1541 * @param key Destination for the generated key.
1542 * @param sender ID of the peer that will encrypt with @c key.
1543 * @param receiver ID of the peer that will decrypt with @c key.
1544 * @param key_material Hash created with ECDH with the ephemeral keys.
1547 derive_symmertic (struct GNUNET_CRYPTO_SymmetricSessionKey *key,
1548 const struct GNUNET_PeerIdentity *sender,
1549 const struct GNUNET_PeerIdentity *receiver,
1550 const struct GNUNET_HashCode *key_material)
1552 const char salt[] = "CADET kx salt";
1554 GNUNET_CRYPTO_kdf (key, sizeof (struct GNUNET_CRYPTO_SymmetricSessionKey),
1555 salt, sizeof (salt),
1556 key_material, sizeof (struct GNUNET_HashCode),
1557 sender, sizeof (struct GNUNET_PeerIdentity),
1558 receiver, sizeof (struct GNUNET_PeerIdentity),
1564 * Derive the tunnel's keys using our own and the peer's ephemeral keys.
1566 * @param t Tunnel for which to create the keys.
1568 * @return GNUNET_OK if successful, GNUNET_SYSERR otherwise.
1571 create_otr_keys (struct CadetTunnel *t)
1573 struct GNUNET_HashCode km;
1575 if (GNUNET_OK != derive_otr_key_material (&km, &t->peers_ephemeral_key))
1576 return GNUNET_SYSERR;
1577 derive_symmertic (&t->e_key, &my_full_id, GCP_get_id (t->peer), &km);
1578 derive_symmertic (&t->d_key, GCP_get_id (t->peer), &my_full_id, &km);
1579 #if DUMP_KEYS_TO_STDERR
1580 LOG (GNUNET_ERROR_TYPE_INFO, "ME: %s\n",
1581 GNUNET_h2s ((struct GNUNET_HashCode *) &otr_kx_msg.ephemeral_key));
1582 LOG (GNUNET_ERROR_TYPE_INFO, "PE: %s\n",
1583 GNUNET_h2s ((struct GNUNET_HashCode *) &t->peers_ephemeral_key));
1584 LOG (GNUNET_ERROR_TYPE_INFO, "KM: %s\n", GNUNET_h2s (&km));
1585 LOG (GNUNET_ERROR_TYPE_INFO, "EK: %s\n",
1586 GNUNET_h2s ((struct GNUNET_HashCode *) &t->e_key));
1587 LOG (GNUNET_ERROR_TYPE_INFO, "DK: %s\n",
1588 GNUNET_h2s ((struct GNUNET_HashCode *) &t->d_key));
1595 * Create a new Key eXchange context for the tunnel.
1597 * If the old keys were verified, keep them for old traffic. Create a new KX
1598 * timestamp and a new nonce.
1600 * @param t Tunnel for which to create the KX ctx.
1602 * @return GNUNET_OK if successful, GNUNET_SYSERR otherwise.
1605 create_kx_ctx (struct CadetTunnel *t)
1607 LOG (GNUNET_ERROR_TYPE_INFO, " new kx ctx for %s\n", GCT_2s (t));
1609 if (NULL != t->kx_ctx)
1611 if (NULL != t->kx_ctx->finish_task)
1613 LOG (GNUNET_ERROR_TYPE_INFO, " resetting exisiting finish task\n");
1614 GNUNET_SCHEDULER_cancel (t->kx_ctx->finish_task);
1615 t->kx_ctx->finish_task = NULL;
1620 t->kx_ctx = GNUNET_new (struct CadetTunnelKXCtx);
1621 t->kx_ctx->challenge = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE,
1625 if (CADET_TUNNEL_KEY_OK == t->estate)
1627 LOG (GNUNET_ERROR_TYPE_INFO, " backing up keys\n");
1628 t->kx_ctx->d_key_old = t->d_key;
1629 t->kx_ctx->e_key_old = t->e_key;
1632 LOG (GNUNET_ERROR_TYPE_INFO, " old keys not valid, not saving\n");
1633 t->kx_ctx->rekey_start_time = GNUNET_TIME_absolute_get ();
1634 return create_otr_keys (t);
1639 * @brief Finish the Key eXchange and destroy the old keys.
1641 * @param cls Closure (Tunnel for which to finish the KX).
1642 * @param tc Task context.
1645 finish_kx (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
1647 struct CadetTunnel *t = cls;
1649 LOG (GNUNET_ERROR_TYPE_INFO, "finish KX for %s\n", GCT_2s (t));
1651 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
1653 LOG (GNUNET_ERROR_TYPE_INFO, " shutdown\n");
1657 GNUNET_free (t->kx_ctx);
1663 * Destroy a Key eXchange context for the tunnel. This function only schedules
1664 * the destruction, the freeing of the memory (and clearing of old key material)
1665 * happens after a delay!
1667 * @param t Tunnel whose KX ctx to destroy.
1670 destroy_kx_ctx (struct CadetTunnel *t)
1672 struct GNUNET_TIME_Relative delay;
1674 if (NULL == t->kx_ctx || NULL != t->kx_ctx->finish_task)
1677 if (is_key_null (&t->kx_ctx->e_key_old))
1679 t->kx_ctx->finish_task = GNUNET_SCHEDULER_add_now (finish_kx, t);
1683 delay = GNUNET_TIME_relative_divide (rekey_period, 4);
1684 delay = GNUNET_TIME_relative_min (delay, GNUNET_TIME_UNIT_MINUTES);
1686 t->kx_ctx->finish_task = GNUNET_SCHEDULER_add_delayed (delay, finish_kx, t);
1692 * Pick a connection on which send the next data message.
1694 * @param t Tunnel on which to send the message.
1696 * @return The connection on which to send the next message.
1698 static struct CadetConnection *
1699 tunnel_get_connection (struct CadetTunnel *t)
1701 struct CadetTConnection *iter;
1702 struct CadetConnection *best;
1704 unsigned int lowest_q;
1706 LOG (GNUNET_ERROR_TYPE_DEBUG, "tunnel_get_connection %s\n", GCT_2s (t));
1708 lowest_q = UINT_MAX;
1709 for (iter = t->connection_head; NULL != iter; iter = iter->next)
1711 LOG (GNUNET_ERROR_TYPE_DEBUG, " connection %s: %u\n",
1712 GCC_2s (iter->c), GCC_get_state (iter->c));
1713 if (CADET_CONNECTION_READY == GCC_get_state (iter->c))
1715 qn = GCC_get_qn (iter->c, GCC_is_origin (iter->c, GNUNET_YES));
1716 LOG (GNUNET_ERROR_TYPE_DEBUG, " q_n %u, \n", qn);
1724 LOG (GNUNET_ERROR_TYPE_DEBUG, " selected: connection %s\n", GCC_2s (best));
1730 * Callback called when a queued message is sent.
1732 * Calculates the average time and connection packet tracking.
1734 * @param cls Closure (TunnelQueue handle).
1735 * @param c Connection this message was on.
1736 * @param q Connection queue handle (unused).
1737 * @param type Type of message sent.
1738 * @param fwd Was this a FWD going message?
1739 * @param size Size of the message.
1742 tun_message_sent (void *cls,
1743 struct CadetConnection *c,
1744 struct CadetConnectionQueue *q,
1745 uint16_t type, int fwd, size_t size)
1747 struct CadetTunnelQueue *qt = cls;
1748 struct CadetTunnel *t;
1750 LOG (GNUNET_ERROR_TYPE_DEBUG, "tun_message_sent\n");
1752 GNUNET_assert (NULL != qt->cont);
1753 t = NULL == c ? NULL : GCC_get_tunnel (c);
1754 qt->cont (qt->cont_cls, t, qt, type, size);
1760 count_queued_data (const struct CadetTunnel *t)
1762 struct CadetTunnelDelayed *iter;
1765 for (count = 0, iter = t->tq_head; iter != NULL; iter = iter->next)
1772 * Delete a queued message: either was sent or the channel was destroyed
1773 * before the tunnel's key exchange had a chance to finish.
1775 * @param tqd Delayed queue handle.
1778 unqueue_data (struct CadetTunnelDelayed *tqd)
1780 GNUNET_CONTAINER_DLL_remove (tqd->t->tq_head, tqd->t->tq_tail, tqd);
1786 * Cache a message to be sent once tunnel is online.
1788 * @param t Tunnel to hold the message.
1789 * @param msg Message itself (copy will be made).
1791 static struct CadetTunnelDelayed *
1792 queue_data (struct CadetTunnel *t, const struct GNUNET_MessageHeader *msg)
1794 struct CadetTunnelDelayed *tqd;
1795 uint16_t size = ntohs (msg->size);
1797 LOG (GNUNET_ERROR_TYPE_DEBUG, "queue data on Tunnel %s\n", GCT_2s (t));
1799 if (GNUNET_YES == is_ready (t))
1805 tqd = GNUNET_malloc (sizeof (struct CadetTunnelDelayed) + size);
1808 memcpy (&tqd[1], msg, size);
1809 GNUNET_CONTAINER_DLL_insert_tail (t->tq_head, t->tq_tail, tqd);
1815 * Sends an already built message on a tunnel, encrypting it and
1816 * choosing the best connection.
1818 * @param message Message to send. Function modifies it.
1819 * @param t Tunnel on which this message is transmitted.
1820 * @param c Connection to use (autoselect if NULL).
1821 * @param force Force the tunnel to take the message (buffer overfill).
1822 * @param cont Continuation to call once message is really sent.
1823 * @param cont_cls Closure for @c cont.
1824 * @param existing_q In case this a transmission of previously queued data,
1825 * this should be TunnelQueue given to the client.
1828 * @return Handle to cancel message.
1829 * NULL if @c cont is NULL or an error happens and message is dropped.
1831 static struct CadetTunnelQueue *
1832 send_prebuilt_message (const struct GNUNET_MessageHeader *message,
1833 struct CadetTunnel *t, struct CadetConnection *c,
1834 int force, GCT_sent cont, void *cont_cls,
1835 struct CadetTunnelQueue *existing_q)
1837 struct GNUNET_MessageHeader *msg;
1838 struct GNUNET_CADET_Encrypted *otr_msg;
1839 struct GNUNET_CADET_AX *ax_msg;
1840 struct CadetTunnelQueue *tq;
1841 size_t size = ntohs (message->size);
1842 const uint16_t max_overhead = sizeof (struct GNUNET_CADET_Encrypted)
1843 + sizeof (struct GNUNET_CADET_AX);
1844 char cbuf[max_overhead + size];
1851 LOG (GNUNET_ERROR_TYPE_DEBUG, "GMT Send on Tunnel %s\n", GCT_2s (t));
1853 if (GNUNET_NO == is_ready (t))
1855 struct CadetTunnelDelayed *tqd;
1856 /* A non null existing_q indicates sending of queued data.
1857 * Should only happen after tunnel becomes ready.
1859 GNUNET_assert (NULL == existing_q);
1860 tqd = queue_data (t, message);
1863 tq = GNUNET_new (struct CadetTunnelQueue);
1867 tq->cont_cls = cont_cls;
1871 GNUNET_assert (GNUNET_NO == GCT_is_loopback (t));
1873 if (CADET_Axolotl == t->enc_type)
1875 ax_msg = (struct GNUNET_CADET_AX *) cbuf;
1876 msg = &ax_msg->header;
1877 msg->size = htons (sizeof (struct GNUNET_CADET_AX) + size);
1878 msg->type = htons (GNUNET_MESSAGE_TYPE_CADET_AX);
1879 ax_msg->reserved = 0;
1880 esize = t_ax_encrypt (t, &ax_msg[1], message, size);
1881 ax_msg->Ns = htonl (t->ax->Ns++);
1882 ax_msg->PNs = htonl (t->ax->PNs);
1883 GNUNET_CRYPTO_ecdhe_key_get_public (t->ax->DHRs, &ax_msg->DHRs);
1884 t_h_encrypt (t, ax_msg);
1885 t_hmac (&ax_msg->Ns, AX_HEADER_SIZE + esize, 0, &t->ax->HKs, &ax_msg->hmac);
1889 otr_msg = (struct GNUNET_CADET_Encrypted *) cbuf;
1890 msg = &otr_msg->header;
1891 iv = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX);
1893 esize = t_encrypt (t, &otr_msg[1], message, size, iv, GNUNET_NO);
1894 t_hmac (&otr_msg[1], size, iv, select_key (t), &otr_msg->hmac);
1895 msg->size = htons (sizeof (struct GNUNET_CADET_Encrypted) + size);
1896 msg->type = htons (GNUNET_MESSAGE_TYPE_CADET_ENCRYPTED);
1897 otr_msg->ttl = htonl (default_ttl);
1899 GNUNET_assert (esize == size);
1902 c = tunnel_get_connection (t);
1905 /* Why is tunnel 'ready'? Should have been queued! */
1906 if (NULL != t->destroy_task)
1909 GCT_debug (t, GNUNET_ERROR_TYPE_WARNING);
1911 return NULL; /* Drop... */
1915 type = ntohs (message->type);
1918 case GNUNET_MESSAGE_TYPE_CADET_DATA:
1919 case GNUNET_MESSAGE_TYPE_CADET_DATA_ACK:
1920 if (GNUNET_MESSAGE_TYPE_CADET_DATA == type)
1921 mid = ntohl (((struct GNUNET_CADET_Data *) message)->mid);
1923 mid = ntohl (((struct GNUNET_CADET_DataACK *) message)->mid);
1925 case GNUNET_MESSAGE_TYPE_CADET_KEEPALIVE:
1926 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_CREATE:
1927 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_DESTROY:
1928 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_ACK:
1929 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_NACK:
1933 LOG (GNUNET_ERROR_TYPE_ERROR, "type %s not valid\n", GC_m2s (type));
1935 LOG (GNUNET_ERROR_TYPE_DEBUG, "type %s\n", GC_m2s (type));
1937 fwd = GCC_is_origin (c, GNUNET_YES);
1941 GNUNET_break (NULL == GCC_send_prebuilt_message (msg, type,
1942 mid, c, fwd, force, NULL, NULL));
1945 if (NULL == existing_q)
1947 tq = GNUNET_new (struct CadetTunnelQueue); /* FIXME valgrind: leak*/
1954 tq->cq = GCC_send_prebuilt_message (msg, type, mid, c, fwd, force,
1955 &tun_message_sent, tq);
1956 GNUNET_assert (NULL != tq->cq);
1958 tq->cont_cls = cont_cls;
1965 * Send all cached messages that we can, tunnel is online.
1967 * @param t Tunnel that holds the messages. Cannot be loopback.
1970 send_queued_data (struct CadetTunnel *t)
1972 struct CadetTunnelDelayed *tqd;
1973 struct CadetTunnelDelayed *next;
1976 LOG (GNUNET_ERROR_TYPE_INFO, "Send queued data, tunnel %s\n", GCT_2s (t));
1978 if (GCT_is_loopback (t))
1984 if (GNUNET_NO == is_ready (t))
1986 LOG (GNUNET_ERROR_TYPE_DEBUG, " not ready yet: %s/%s\n",
1987 estate2s (t->estate), cstate2s (t->cstate));
1991 room = GCT_get_connections_buffer (t);
1992 LOG (GNUNET_ERROR_TYPE_DEBUG, " buffer space: %u\n", room);
1993 LOG (GNUNET_ERROR_TYPE_DEBUG, " tq head: %p\n", t->tq_head);
1994 for (tqd = t->tq_head; NULL != tqd && room > 0; tqd = next)
1996 LOG (GNUNET_ERROR_TYPE_DEBUG, " sending queued data\n");
1999 send_prebuilt_message ((struct GNUNET_MessageHeader *) &tqd[1],
2000 tqd->t, NULL, GNUNET_YES,
2001 NULL != tqd->tq ? tqd->tq->cont : NULL,
2002 NULL != tqd->tq ? tqd->tq->cont_cls : NULL,
2006 LOG (GNUNET_ERROR_TYPE_DEBUG, "GCT_send_queued_data end\n", GCP_2s (t->peer));
2011 * Callback called when a queued message is sent.
2013 * @param cls Closure.
2014 * @param c Connection this message was on.
2015 * @param type Type of message sent.
2016 * @param fwd Was this a FWD going message?
2017 * @param size Size of the message.
2020 ephm_sent (void *cls,
2021 struct CadetConnection *c,
2022 struct CadetConnectionQueue *q,
2023 uint16_t type, int fwd, size_t size)
2025 struct CadetTunnel *t = cls;
2026 LOG (GNUNET_ERROR_TYPE_DEBUG, "ephemeral sent %s\n", GC_m2s (type));
2031 * Callback called when a queued message is sent.
2033 * @param cls Closure.
2034 * @param c Connection this message was on.
2035 * @param type Type of message sent.
2036 * @param fwd Was this a FWD going message?
2037 * @param size Size of the message.
2040 pong_sent (void *cls,
2041 struct CadetConnection *c,
2042 struct CadetConnectionQueue *q,
2043 uint16_t type, int fwd, size_t size)
2045 struct CadetTunnel *t = cls;
2046 LOG (GNUNET_ERROR_TYPE_DEBUG, "pong_sent %s\n", GC_m2s (type));
2052 * Sends key exchange message on a tunnel, choosing the best connection.
2053 * Should not be called on loopback tunnels.
2055 * @param t Tunnel on which this message is transmitted.
2056 * @param message Message to send. Function modifies it.
2058 * @return Handle to the message in the connection queue.
2060 static struct CadetConnectionQueue *
2061 send_kx (struct CadetTunnel *t,
2062 const struct GNUNET_MessageHeader *message)
2064 struct CadetConnection *c;
2065 struct GNUNET_CADET_KX *msg;
2066 size_t size = ntohs (message->size);
2067 char cbuf[sizeof (struct GNUNET_CADET_KX) + size];
2072 LOG (GNUNET_ERROR_TYPE_DEBUG, "GMT KX on Tunnel %s\n", GCT_2s (t));
2074 /* Avoid loopback. */
2075 if (GCT_is_loopback (t))
2080 type = ntohs (message->type);
2082 /* Even if tunnel is "being destroyed", send anyway.
2083 * Could be a response to a rekey initiated by remote peer,
2084 * who is trying to create a new channel!
2087 /* Must have a connection, or be looking for one. */
2088 if (NULL == t->connection_head)
2090 LOG (GNUNET_ERROR_TYPE_DEBUG, "%s with no connection\n", GC_m2s (type));
2091 if (CADET_TUNNEL_SEARCHING != t->cstate)
2094 GCT_debug (t, GNUNET_ERROR_TYPE_ERROR);
2095 GCP_debug (t->peer, GNUNET_ERROR_TYPE_ERROR);
2100 msg = (struct GNUNET_CADET_KX *) cbuf;
2101 msg->header.type = htons (GNUNET_MESSAGE_TYPE_CADET_KX);
2102 msg->header.size = htons (sizeof (struct GNUNET_CADET_KX) + size);
2103 c = tunnel_get_connection (t);
2106 if (NULL == t->destroy_task && CADET_TUNNEL_READY == t->cstate)
2109 GCT_debug (t, GNUNET_ERROR_TYPE_ERROR);
2115 case GNUNET_MESSAGE_TYPE_CADET_KX_EPHEMERAL:
2116 case GNUNET_MESSAGE_TYPE_CADET_AX_KX:
2117 GNUNET_assert (NULL == t->ephm_h);
2120 case GNUNET_MESSAGE_TYPE_CADET_KX_PONG:
2121 GNUNET_assert (NULL == t->pong_h);
2126 LOG (GNUNET_ERROR_TYPE_DEBUG, "unkown type %s\n", GC_m2s (type));
2129 memcpy (&msg[1], message, size);
2131 fwd = GCC_is_origin (c, GNUNET_YES);
2133 return GCC_send_prebuilt_message (&msg->header, type, 0, c,
2140 * Send the ephemeral key on a tunnel.
2142 * @param t Tunnel on which to send the key.
2145 send_ephemeral (struct CadetTunnel *t)
2147 LOG (GNUNET_ERROR_TYPE_INFO, "===> EPHM for %s\n", GCT_2s (t));
2148 if (NULL != t->ephm_h)
2150 LOG (GNUNET_ERROR_TYPE_INFO, " already queued\n");
2154 otr_kx_msg.sender_status = htonl (t->estate);
2155 otr_kx_msg.iv = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX);
2156 otr_kx_msg.nonce = t->kx_ctx->challenge;
2157 LOG (GNUNET_ERROR_TYPE_DEBUG, " send nonce c %u\n", otr_kx_msg.nonce);
2158 t_encrypt (t, &otr_kx_msg.nonce, &otr_kx_msg.nonce,
2159 ping_encryption_size(), otr_kx_msg.iv, GNUNET_YES);
2160 LOG (GNUNET_ERROR_TYPE_DEBUG, " send nonce e %u\n", otr_kx_msg.nonce);
2161 t->ephm_h = send_kx (t, &otr_kx_msg.header);
2166 * Send a pong message on a tunnel.
2168 * @param t Tunnel on which to send the pong.
2169 * @param challenge Value sent in the ping that we have to send back.
2172 send_pong (struct CadetTunnel *t, uint32_t challenge)
2174 struct GNUNET_CADET_KX_Pong msg;
2176 LOG (GNUNET_ERROR_TYPE_INFO, "===> PONG for %s\n", GCT_2s (t));
2177 if (NULL != t->pong_h)
2179 LOG (GNUNET_ERROR_TYPE_INFO, " already queued\n");
2182 msg.header.size = htons (sizeof (msg));
2183 msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_KX_PONG);
2184 msg.iv = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX);
2185 msg.nonce = challenge;
2186 LOG (GNUNET_ERROR_TYPE_DEBUG, " sending %u\n", msg.nonce);
2187 t_encrypt (t, &msg.nonce, &msg.nonce,
2188 sizeof (msg.nonce), msg.iv, GNUNET_YES);
2189 LOG (GNUNET_ERROR_TYPE_DEBUG, " e sending %u\n", msg.nonce);
2191 t->pong_h = send_kx (t, &msg.header);
2196 * Initiate a rekey with the remote peer.
2198 * @param cls Closure (tunnel).
2199 * @param tc TaskContext.
2202 rekey_tunnel (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
2204 struct CadetTunnel *t = cls;
2206 t->rekey_task = NULL;
2208 LOG (GNUNET_ERROR_TYPE_INFO, "Re-key Tunnel %s\n", GCT_2s (t));
2209 if (NULL != tc && 0 != (GNUNET_SCHEDULER_REASON_SHUTDOWN & tc->reason))
2212 GNUNET_assert (NULL != t->kx_ctx);
2213 struct GNUNET_TIME_Relative duration;
2215 duration = GNUNET_TIME_absolute_get_duration (t->kx_ctx->rekey_start_time);
2216 LOG (GNUNET_ERROR_TYPE_DEBUG, " kx started %s ago\n",
2217 GNUNET_STRINGS_relative_time_to_string (duration, GNUNET_YES));
2219 // FIXME make duration of old keys configurable
2220 if (duration.rel_value_us >= GNUNET_TIME_UNIT_MINUTES.rel_value_us)
2222 LOG (GNUNET_ERROR_TYPE_DEBUG, " deleting old keys\n");
2223 memset (&t->kx_ctx->d_key_old, 0, sizeof (t->kx_ctx->d_key_old));
2224 memset (&t->kx_ctx->e_key_old, 0, sizeof (t->kx_ctx->e_key_old));
2231 case CADET_TUNNEL_KEY_UNINITIALIZED:
2232 GCT_change_estate (t, CADET_TUNNEL_KEY_SENT);
2235 case CADET_TUNNEL_KEY_SENT:
2238 case CADET_TUNNEL_KEY_OK:
2240 * - state should have changed during rekey_iterator
2241 * - task should have been canceled at pong_handle
2244 GCT_change_estate (t, CADET_TUNNEL_KEY_REKEY);
2247 case CADET_TUNNEL_KEY_PING:
2248 case CADET_TUNNEL_KEY_REKEY:
2252 LOG (GNUNET_ERROR_TYPE_DEBUG, "Unexpected state %u\n", t->estate);
2255 // FIXME exponential backoff
2256 struct GNUNET_TIME_Relative delay;
2258 delay = GNUNET_TIME_relative_divide (rekey_period, 16);
2259 delay = GNUNET_TIME_relative_min (delay, REKEY_WAIT);
2260 LOG (GNUNET_ERROR_TYPE_DEBUG, " next call in %s\n",
2261 GNUNET_STRINGS_relative_time_to_string (delay, GNUNET_YES));
2262 t->rekey_task = GNUNET_SCHEDULER_add_delayed (delay, &rekey_tunnel, t);
2267 * Our ephemeral key has changed, create new session key on all tunnels.
2269 * Each tunnel will start the Key Exchange with a random delay between
2270 * 0 and number_of_tunnels*100 milliseconds, so there are 10 key exchanges
2271 * per second, on average.
2273 * @param cls Closure (size of the hashmap).
2274 * @param key Current public key.
2275 * @param value Value in the hash map (tunnel).
2277 * @return #GNUNET_YES, so we should continue to iterate,
2280 rekey_iterator (void *cls,
2281 const struct GNUNET_PeerIdentity *key,
2284 struct CadetTunnel *t = value;
2285 struct GNUNET_TIME_Relative delay;
2286 long n = (long) cls;
2289 if (NULL != t->rekey_task)
2292 if (GNUNET_YES == GCT_is_loopback (t))
2295 if (CADET_OTR != t->enc_type)
2298 r = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK, (uint32_t) n * 100);
2299 delay = GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MILLISECONDS, r);
2300 t->rekey_task = GNUNET_SCHEDULER_add_delayed (delay, &rekey_tunnel, t);
2301 if (GNUNET_OK == create_kx_ctx (t))
2302 GCT_change_estate (t, CADET_TUNNEL_KEY_REKEY);
2314 * Create a new ephemeral key and key message, schedule next rekeying.
2316 * @param cls Closure (unused).
2317 * @param tc TaskContext.
2320 global_otr_rekey (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
2322 struct GNUNET_TIME_Absolute time;
2327 if (0 != (GNUNET_SCHEDULER_REASON_SHUTDOWN & tc->reason))
2330 GNUNET_free_non_null (otr_ephemeral_key);
2331 otr_ephemeral_key = GNUNET_CRYPTO_ecdhe_key_create ();
2333 time = GNUNET_TIME_absolute_get ();
2334 otr_kx_msg.creation_time = GNUNET_TIME_absolute_hton (time);
2335 time = GNUNET_TIME_absolute_add (time, rekey_period);
2336 time = GNUNET_TIME_absolute_add (time, GNUNET_TIME_UNIT_MINUTES);
2337 otr_kx_msg.expiration_time = GNUNET_TIME_absolute_hton (time);
2338 GNUNET_CRYPTO_ecdhe_key_get_public (otr_ephemeral_key, &otr_kx_msg.ephemeral_key);
2339 LOG (GNUNET_ERROR_TYPE_INFO, "GLOBAL OTR RE-KEY, NEW EPHM: %s\n",
2340 GNUNET_h2s ((struct GNUNET_HashCode *) &otr_kx_msg.ephemeral_key));
2342 GNUNET_assert (GNUNET_OK ==
2343 GNUNET_CRYPTO_eddsa_sign (id_key,
2344 &otr_kx_msg.purpose,
2345 &otr_kx_msg.signature));
2347 n = (long) GNUNET_CONTAINER_multipeermap_size (tunnels);
2348 GNUNET_CONTAINER_multipeermap_iterate (tunnels, &rekey_iterator, (void *) n);
2350 rekey_task = GNUNET_SCHEDULER_add_delayed (rekey_period,
2351 &global_otr_rekey, NULL);
2356 * Called only on shutdown, destroy every tunnel.
2358 * @param cls Closure (unused).
2359 * @param key Current public key.
2360 * @param value Value in the hash map (tunnel).
2362 * @return #GNUNET_YES, so we should continue to iterate,
2365 destroy_iterator (void *cls,
2366 const struct GNUNET_PeerIdentity *key,
2369 struct CadetTunnel *t = value;
2371 LOG (GNUNET_ERROR_TYPE_DEBUG, "GCT_shutdown destroying tunnel at %p\n", t);
2378 * Notify remote peer that we don't know a channel he is talking about,
2379 * probably CHANNEL_DESTROY was missed.
2381 * @param t Tunnel on which to notify.
2382 * @param gid ID of the channel.
2385 send_channel_destroy (struct CadetTunnel *t, unsigned int gid)
2387 struct GNUNET_CADET_ChannelManage msg;
2389 msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_CHANNEL_DESTROY);
2390 msg.header.size = htons (sizeof (msg));
2391 msg.chid = htonl (gid);
2393 LOG (GNUNET_ERROR_TYPE_DEBUG,
2394 "WARNING destroying unknown channel %u on tunnel %s\n",
2396 send_prebuilt_message (&msg.header, t, NULL, GNUNET_YES, NULL, NULL, NULL);
2401 * Demultiplex data per channel and call appropriate channel handler.
2403 * @param t Tunnel on which the data came.
2404 * @param msg Data message.
2405 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
2406 * #GNUNET_YES if message is FWD on the respective channel (loopback)
2407 * #GNUNET_NO if message is BCK on the respective channel (loopback)
2408 * #GNUNET_SYSERR if message on a one-ended channel (remote)
2411 handle_data (struct CadetTunnel *t,
2412 const struct GNUNET_CADET_Data *msg,
2415 struct CadetChannel *ch;
2419 size = ntohs (msg->header.size);
2421 sizeof (struct GNUNET_CADET_Data) +
2422 sizeof (struct GNUNET_MessageHeader))
2427 LOG (GNUNET_ERROR_TYPE_DEBUG, " payload of type %s\n",
2428 GC_m2s (ntohs (msg[1].header.type)));
2431 ch = GCT_get_channel (t, ntohl (msg->chid));
2434 GNUNET_STATISTICS_update (stats, "# data on unknown channel",
2436 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel 0x%X unknown\n",
2438 send_channel_destroy (t, ntohl (msg->chid));
2442 GCCH_handle_data (ch, msg, fwd);
2447 * Demultiplex data ACKs per channel and update appropriate channel buffer info.
2449 * @param t Tunnel on which the DATA ACK came.
2450 * @param msg DATA ACK message.
2451 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
2452 * #GNUNET_YES if message is FWD on the respective channel (loopback)
2453 * #GNUNET_NO if message is BCK on the respective channel (loopback)
2454 * #GNUNET_SYSERR if message on a one-ended channel (remote)
2457 handle_data_ack (struct CadetTunnel *t,
2458 const struct GNUNET_CADET_DataACK *msg,
2461 struct CadetChannel *ch;
2465 size = ntohs (msg->header.size);
2466 if (size != sizeof (struct GNUNET_CADET_DataACK))
2473 ch = GCT_get_channel (t, ntohl (msg->chid));
2476 GNUNET_STATISTICS_update (stats, "# data ack on unknown channel",
2478 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel %u unknown\n",
2483 GCCH_handle_data_ack (ch, msg, fwd);
2488 * Handle channel create.
2490 * @param t Tunnel on which the data came.
2491 * @param msg Data message.
2494 handle_ch_create (struct CadetTunnel *t,
2495 const struct GNUNET_CADET_ChannelCreate *msg)
2497 struct CadetChannel *ch;
2501 size = ntohs (msg->header.size);
2502 if (size != sizeof (struct GNUNET_CADET_ChannelCreate))
2509 ch = GCT_get_channel (t, ntohl (msg->chid));
2510 if (NULL != ch && ! GCT_is_loopback (t))
2512 /* Probably a retransmission, safe to ignore */
2513 LOG (GNUNET_ERROR_TYPE_DEBUG, " already exists...\n");
2515 ch = GCCH_handle_create (t, msg);
2517 GCT_add_channel (t, ch);
2523 * Handle channel NACK: check correctness and call channel handler for NACKs.
2525 * @param t Tunnel on which the NACK came.
2526 * @param msg NACK message.
2529 handle_ch_nack (struct CadetTunnel *t,
2530 const struct GNUNET_CADET_ChannelManage *msg)
2532 struct CadetChannel *ch;
2536 size = ntohs (msg->header.size);
2537 if (size != sizeof (struct GNUNET_CADET_ChannelManage))
2544 ch = GCT_get_channel (t, ntohl (msg->chid));
2547 GNUNET_STATISTICS_update (stats, "# channel NACK on unknown channel",
2549 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel %u unknown\n",
2554 GCCH_handle_nack (ch);
2559 * Handle a CHANNEL ACK (SYNACK/ACK).
2561 * @param t Tunnel on which the CHANNEL ACK came.
2562 * @param msg CHANNEL ACK message.
2563 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
2564 * #GNUNET_YES if message is FWD on the respective channel (loopback)
2565 * #GNUNET_NO if message is BCK on the respective channel (loopback)
2566 * #GNUNET_SYSERR if message on a one-ended channel (remote)
2569 handle_ch_ack (struct CadetTunnel *t,
2570 const struct GNUNET_CADET_ChannelManage *msg,
2573 struct CadetChannel *ch;
2577 size = ntohs (msg->header.size);
2578 if (size != sizeof (struct GNUNET_CADET_ChannelManage))
2585 ch = GCT_get_channel (t, ntohl (msg->chid));
2588 GNUNET_STATISTICS_update (stats, "# channel ack on unknown channel",
2590 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel %u unknown\n",
2595 GCCH_handle_ack (ch, msg, fwd);
2600 * Handle a channel destruction message.
2602 * @param t Tunnel on which the message came.
2603 * @param msg Channel destroy message.
2604 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
2605 * #GNUNET_YES if message is FWD on the respective channel (loopback)
2606 * #GNUNET_NO if message is BCK on the respective channel (loopback)
2607 * #GNUNET_SYSERR if message on a one-ended channel (remote)
2610 handle_ch_destroy (struct CadetTunnel *t,
2611 const struct GNUNET_CADET_ChannelManage *msg,
2614 struct CadetChannel *ch;
2618 size = ntohs (msg->header.size);
2619 if (size != sizeof (struct GNUNET_CADET_ChannelManage))
2626 ch = GCT_get_channel (t, ntohl (msg->chid));
2629 /* Probably a retransmission, safe to ignore */
2633 GCCH_handle_destroy (ch, msg, fwd);
2638 * Create a new Axolotl ephemeral (ratchet) key.
2643 new_ephemeral (struct CadetTunnel *t)
2645 GNUNET_free_non_null (t->ax->DHRs);
2646 t->ax->DHRs = GNUNET_CRYPTO_ecdhe_key_create();
2651 * Free Axolotl data.
2656 destroy_ax (struct CadetTunnel *t)
2661 GNUNET_free_non_null (t->ax->DHRs);
2662 GNUNET_free_non_null (t->ax->kx_0);
2664 GNUNET_free (t->ax);
2671 * The peer's ephemeral key has changed: update the symmetrical keys.
2673 * @param t Tunnel this message came on.
2674 * @param msg Key eXchange message.
2677 handle_ephemeral (struct CadetTunnel *t,
2678 const struct GNUNET_CADET_KX_Ephemeral *msg)
2680 LOG (GNUNET_ERROR_TYPE_INFO, "<=== EPHM for %s\n", GCT_2s (t));
2682 if (GNUNET_OK != check_ephemeral (t, msg))
2684 GNUNET_break_op (0);
2688 /* If we get a proper OTR-style ephemeral, fallback to old crypto. */
2692 t->enc_type = CADET_OTR;
2693 if (NULL != t->rekey_task)
2694 GNUNET_SCHEDULER_cancel (t->rekey_task);
2695 if (GNUNET_OK != create_kx_ctx (t))
2701 rekey_tunnel (t, NULL);
2702 GNUNET_STATISTICS_update (stats, "# otr-downgrades", -1, GNUNET_NO);
2706 * If the key is different from what we know, derive the new E/D keys.
2707 * Else destroy the rekey ctx (duplicate EPHM after successful KX).
2709 if (0 != memcmp (&t->peers_ephemeral_key, &msg->ephemeral_key,
2710 sizeof (msg->ephemeral_key)))
2712 #if DUMP_KEYS_TO_STDERR
2713 LOG (GNUNET_ERROR_TYPE_INFO, "OLD: %s\n",
2714 GNUNET_h2s ((struct GNUNET_HashCode *) &t->peers_ephemeral_key));
2715 LOG (GNUNET_ERROR_TYPE_INFO, "NEW: %s\n",
2716 GNUNET_h2s ((struct GNUNET_HashCode *) &msg->ephemeral_key));
2718 t->peers_ephemeral_key = msg->ephemeral_key;
2720 if (GNUNET_OK != create_kx_ctx (t))
2727 if (CADET_TUNNEL_KEY_OK == t->estate)
2729 GCT_change_estate (t, CADET_TUNNEL_KEY_REKEY);
2731 if (NULL != t->rekey_task)
2732 GNUNET_SCHEDULER_cancel (t->rekey_task);
2733 t->rekey_task = GNUNET_SCHEDULER_add_now (rekey_tunnel, t);
2735 if (CADET_TUNNEL_KEY_SENT == t->estate)
2737 LOG (GNUNET_ERROR_TYPE_DEBUG, " our key was sent, sending challenge\n");
2739 GCT_change_estate (t, CADET_TUNNEL_KEY_PING);
2742 if (CADET_TUNNEL_KEY_UNINITIALIZED != ntohl(msg->sender_status))
2746 LOG (GNUNET_ERROR_TYPE_DEBUG, " recv nonce e %u\n", msg->nonce);
2747 t_decrypt (t, &nonce, &msg->nonce, ping_encryption_size (), msg->iv);
2748 LOG (GNUNET_ERROR_TYPE_DEBUG, " recv nonce c %u\n", nonce);
2749 send_pong (t, nonce);
2755 * Peer has answer to our challenge.
2756 * If answer is successful, consider the key exchange finished and clean
2757 * up all related state.
2759 * @param t Tunnel this message came on.
2760 * @param msg Key eXchange Pong message.
2763 handle_pong (struct CadetTunnel *t, const struct GNUNET_CADET_KX_Pong *msg)
2767 LOG (GNUNET_ERROR_TYPE_INFO, "<=== PONG for %s\n", GCT_2s (t));
2768 if (NULL == t->rekey_task)
2770 GNUNET_STATISTICS_update (stats, "# duplicate PONG messages", 1, GNUNET_NO);
2773 if (NULL == t->kx_ctx)
2775 GNUNET_STATISTICS_update (stats, "# stray PONG messages", 1, GNUNET_NO);
2779 t_decrypt (t, &challenge, &msg->nonce, sizeof (uint32_t), msg->iv);
2780 if (challenge != t->kx_ctx->challenge)
2782 LOG (GNUNET_ERROR_TYPE_WARNING, "Wrong PONG challenge on %s\n", GCT_2s (t));
2783 LOG (GNUNET_ERROR_TYPE_DEBUG, "PONG: %u (e: %u). Expected: %u.\n",
2784 challenge, msg->nonce, t->kx_ctx->challenge);
2788 GNUNET_SCHEDULER_cancel (t->rekey_task);
2789 t->rekey_task = NULL;
2791 /* Don't free the old keys right away, but after a delay.
2792 * Rationale: the KX could have happened over a very fast connection,
2793 * with payload traffic still signed with the old key stuck in a slower
2795 * Don't keep the keys longer than 1/4 the rekey period, and no longer than
2799 GCT_change_estate (t, CADET_TUNNEL_KEY_OK);
2804 * Handle Axolotl handshake.
2806 * @param t Tunnel this message came on.
2807 * @param msg Key eXchange Pong message.
2810 handle_kx_ax (struct CadetTunnel *t, const struct GNUNET_CADET_AX_KX *msg)
2812 struct CadetTunnelAxolotl *ax;
2813 struct GNUNET_HashCode key_material[3];
2814 struct GNUNET_CRYPTO_SymmetricSessionKey keys[5];
2815 const struct GNUNET_CRYPTO_EcdhePublicKey *pub;
2816 const struct GNUNET_CRYPTO_EcdhePrivateKey *priv;
2817 const char salt[] = "CADET Axolotl salt";
2818 const struct GNUNET_PeerIdentity *pid;
2821 LOG (GNUNET_ERROR_TYPE_INFO, "<=== AX_KX on %s\n", GCT_2s (t));
2825 /* Something is wrong if ax is NULL. Whose fault it is? */
2826 GNUNET_break_op (CADET_OTR == t->enc_type);
2827 GNUNET_break (CADET_Axolotl == t->enc_type);
2831 if (GNUNET_OK != GCP_check_key (t->peer, &msg->permanent_key,
2832 &msg->purpose, &msg->signature))
2834 GNUNET_break_op (0);
2838 pid = GCT_get_destination (t);
2839 if (0 > GNUNET_CRYPTO_cmp_peer_identity (&my_full_id, pid))
2840 am_I_alice = GNUNET_YES;
2841 else if (0 < GNUNET_CRYPTO_cmp_peer_identity (&my_full_id, pid))
2842 am_I_alice = GNUNET_NO;
2845 GNUNET_break_op (0);
2849 LOG (GNUNET_ERROR_TYPE_INFO, " is Alice? %s\n", am_I_alice ? "YES" : "NO");
2852 ax->DHRr = msg->ratchet_key;
2853 ax->DHIr = msg->permanent_key;
2856 if (GNUNET_YES == am_I_alice)
2858 priv = ax_key; /* A */
2859 pub = &msg->ephemeral_key; /* B0 */
2863 priv = ax->kx_0; /* B0 */
2864 pub = &ax->DHIr; /* A */
2866 GNUNET_CRYPTO_ecc_ecdh (priv, pub, &key_material[0]);
2869 if (GNUNET_YES == am_I_alice)
2871 priv = ax->kx_0; /* A0 */
2872 pub = &ax->DHIr; /* B */
2876 priv = ax_key; /* B */
2877 pub = &msg->ephemeral_key; /* A0 */
2879 GNUNET_CRYPTO_ecc_ecdh (priv, pub, &key_material[1]);
2882 priv = ax->kx_0; /* A0 or B0 */
2883 pub = &msg->ephemeral_key; /* B0 or A0 */
2884 GNUNET_CRYPTO_ecc_ecdh (priv, pub, &key_material[2]);
2886 #if DUMP_KEYS_TO_STDERR
2889 for (i = 0; i < 3; i++)
2890 LOG (GNUNET_ERROR_TYPE_INFO, "km[%u]: %s\n",
2891 i, GNUNET_h2s (&key_material[i]));
2896 GNUNET_CRYPTO_kdf (keys, sizeof (keys),
2897 salt, sizeof (salt),
2898 &key_material, sizeof (key_material), NULL);
2901 if (GNUNET_YES == am_I_alice)
2907 ax->ratchet_flag = GNUNET_YES;
2915 ax->ratchet_flag = GNUNET_NO;
2916 ax->ratchet_allowed = GNUNET_NO;
2917 ax->ratchet_counter = 0;
2918 ax->ratchet_expiration =
2919 GNUNET_TIME_absolute_add (GNUNET_TIME_absolute_get(), ratchet_time);
2921 GCT_change_estate (t, CADET_TUNNEL_KEY_OK);
2926 * Demultiplex by message type and call appropriate handler for a message
2927 * towards a channel of a local tunnel.
2929 * @param t Tunnel this message came on.
2930 * @param msgh Message header.
2931 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
2932 * #GNUNET_YES if message is FWD on the respective channel (loopback)
2933 * #GNUNET_NO if message is BCK on the respective channel (loopback)
2934 * #GNUNET_SYSERR if message on a one-ended channel (remote)
2937 handle_decrypted (struct CadetTunnel *t,
2938 const struct GNUNET_MessageHeader *msgh,
2943 type = ntohs (msgh->type);
2944 LOG (GNUNET_ERROR_TYPE_INFO, "<=== %s on %s\n", GC_m2s (type), GCT_2s (t));
2948 case GNUNET_MESSAGE_TYPE_CADET_KEEPALIVE:
2949 /* Do nothing, connection aleady got updated. */
2950 GNUNET_STATISTICS_update (stats, "# keepalives received", 1, GNUNET_NO);
2953 case GNUNET_MESSAGE_TYPE_CADET_DATA:
2954 /* Don't send hop ACK, wait for client to ACK */
2955 handle_data (t, (struct GNUNET_CADET_Data *) msgh, fwd);
2958 case GNUNET_MESSAGE_TYPE_CADET_DATA_ACK:
2959 handle_data_ack (t, (struct GNUNET_CADET_DataACK *) msgh, fwd);
2962 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_CREATE:
2963 handle_ch_create (t, (struct GNUNET_CADET_ChannelCreate *) msgh);
2966 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_NACK:
2967 handle_ch_nack (t, (struct GNUNET_CADET_ChannelManage *) msgh);
2970 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_ACK:
2971 handle_ch_ack (t, (struct GNUNET_CADET_ChannelManage *) msgh, fwd);
2974 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_DESTROY:
2975 handle_ch_destroy (t, (struct GNUNET_CADET_ChannelManage *) msgh, fwd);
2979 GNUNET_break_op (0);
2980 LOG (GNUNET_ERROR_TYPE_WARNING,
2981 "end-to-end message not known (%u)\n",
2982 ntohs (msgh->type));
2983 GCT_debug (t, GNUNET_ERROR_TYPE_WARNING);
2987 /******************************************************************************/
2988 /******************************** API ***********************************/
2989 /******************************************************************************/
2991 * Decrypt old format and demultiplex by message type. Call appropriate handler
2992 * for a message towards a channel of a local tunnel.
2994 * @param t Tunnel this message came on.
2995 * @param msg Message header.
2998 GCT_handle_encrypted (struct CadetTunnel *t,
2999 const struct GNUNET_MessageHeader *msg)
3001 uint16_t size = ntohs (msg->size);
3003 size_t payload_size;
3006 struct GNUNET_MessageHeader *msgh;
3009 type = ntohs (msg->type);
3010 if (GNUNET_MESSAGE_TYPE_CADET_ENCRYPTED == type)
3012 const struct GNUNET_CADET_Encrypted *emsg;
3014 emsg = (struct GNUNET_CADET_Encrypted *) msg;
3015 payload_size = size - sizeof (struct GNUNET_CADET_Encrypted);
3016 decrypted_size = t_decrypt_and_validate (t, cbuf, &emsg[1], payload_size,
3017 emsg->iv, &emsg->hmac);
3019 else if (GNUNET_MESSAGE_TYPE_CADET_AX == type)
3021 const struct GNUNET_CADET_AX *emsg;
3023 emsg = (struct GNUNET_CADET_AX *) msg;
3024 decrypted_size = t_ax_decrypt_and_validate (t, cbuf, emsg, size);
3027 if (-1 == decrypted_size)
3029 GNUNET_break_op (0);
3034 while (off < decrypted_size)
3038 msgh = (struct GNUNET_MessageHeader *) &cbuf[off];
3039 msize = ntohs (msgh->size);
3040 if (msize < sizeof (struct GNUNET_MessageHeader))
3042 GNUNET_break_op (0);
3045 handle_decrypted (t, msgh, GNUNET_SYSERR);
3052 * Demultiplex an encapsulated KX message by message type.
3054 * @param t Tunnel on which the message came.
3055 * @param message Payload of KX message.
3058 GCT_handle_kx (struct CadetTunnel *t,
3059 const struct GNUNET_MessageHeader *message)
3063 type = ntohs (message->type);
3064 LOG (GNUNET_ERROR_TYPE_DEBUG, "kx message received: %s\n", GC_m2s (type));
3067 case GNUNET_MESSAGE_TYPE_CADET_KX_EPHEMERAL:
3068 handle_ephemeral (t, (const struct GNUNET_CADET_KX_Ephemeral *) message);
3071 case GNUNET_MESSAGE_TYPE_CADET_KX_PONG:
3072 handle_pong (t, (const struct GNUNET_CADET_KX_Pong *) message);
3075 case GNUNET_MESSAGE_TYPE_CADET_AX_KX:
3076 handle_kx_ax (t, (const struct GNUNET_CADET_AX_KX *) message);
3080 GNUNET_break_op (0);
3081 LOG (GNUNET_ERROR_TYPE_WARNING, "kx message %s unknown\n", GC_m2s (type));
3086 * Initialize the tunnel subsystem.
3088 * @param c Configuration handle.
3089 * @param key ECC private key, to derive all other keys and do crypto.
3092 GCT_init (const struct GNUNET_CONFIGURATION_Handle *c,
3093 const struct GNUNET_CRYPTO_EddsaPrivateKey *key)
3095 int expected_overhead;
3097 LOG (GNUNET_ERROR_TYPE_DEBUG, "init\n");
3099 expected_overhead = 0;
3100 expected_overhead += sizeof (struct GNUNET_CADET_Encrypted);
3101 expected_overhead += sizeof (struct GNUNET_CADET_Data);
3102 expected_overhead += sizeof (struct GNUNET_CADET_ACK);
3103 GNUNET_assert (GNUNET_CONSTANTS_CADET_P2P_OVERHEAD == expected_overhead);
3106 GNUNET_CONFIGURATION_get_value_number (c, "CADET", "DEFAULT_TTL",
3109 GNUNET_log_config_invalid (GNUNET_ERROR_TYPE_DEBUG,
3110 "CADET", "DEFAULT_TTL", "USING DEFAULT");
3114 GNUNET_CONFIGURATION_get_value_time (c, "CADET", "REKEY_PERIOD",
3117 rekey_period = GNUNET_TIME_UNIT_DAYS;
3120 GNUNET_CONFIGURATION_get_value_number (c, "CADET", "RATCHET_MESSAGES",
3123 GNUNET_log_config_invalid (GNUNET_ERROR_TYPE_WARNING,
3124 "CADET", "RATCHET_MESSAGES", "USING DEFAULT");
3125 ratchet_messages = 64;
3128 GNUNET_CONFIGURATION_get_value_time (c, "CADET", "RATCHET_TIME",
3131 GNUNET_log_config_invalid (GNUNET_ERROR_TYPE_WARNING,
3132 "CADET", "RATCHET_TIME", "USING DEFAULT");
3133 ratchet_time = GNUNET_TIME_UNIT_HOURS;
3139 otr_kx_msg.header.size = htons (sizeof (otr_kx_msg));
3140 otr_kx_msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_KX_EPHEMERAL);
3141 otr_kx_msg.purpose.purpose = htonl (GNUNET_SIGNATURE_PURPOSE_CADET_KX);
3142 otr_kx_msg.purpose.size = htonl (ephemeral_purpose_size ());
3143 otr_kx_msg.origin_identity = my_full_id;
3144 rekey_task = GNUNET_SCHEDULER_add_now (&global_otr_rekey, NULL);
3146 ax_key = GNUNET_CRYPTO_ecdhe_key_create ();
3147 GNUNET_CRYPTO_ecdhe_key_get_public (ax_key, &ax_identity.permanent_key);
3148 ax_identity.purpose.purpose = htonl (GNUNET_SIGNATURE_PURPOSE_CADET_AXKX);
3149 ax_identity.purpose.size = htonl (ax_purpose_size ());
3150 GNUNET_assert (GNUNET_OK ==
3151 GNUNET_CRYPTO_eddsa_sign (id_key,
3152 &ax_identity.purpose,
3153 &ax_identity.signature));
3155 tunnels = GNUNET_CONTAINER_multipeermap_create (128, GNUNET_YES);
3160 * Shut down the tunnel subsystem.
3165 if (NULL != rekey_task)
3167 GNUNET_SCHEDULER_cancel (rekey_task);
3170 GNUNET_CONTAINER_multipeermap_iterate (tunnels, &destroy_iterator, NULL);
3171 GNUNET_CONTAINER_multipeermap_destroy (tunnels);
3172 GNUNET_free (ax_key);
3179 * @param destination Peer this tunnel is towards.
3181 struct CadetTunnel *
3182 GCT_new (struct CadetPeer *destination)
3184 struct CadetTunnel *t;
3186 t = GNUNET_new (struct CadetTunnel);
3188 t->peer = destination;
3191 GNUNET_CONTAINER_multipeermap_put (tunnels, GCP_get_id (destination), t,
3192 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_FAST))
3198 t->ax = GNUNET_new (struct CadetTunnelAxolotl);
3200 t->ax->kx_0 = GNUNET_CRYPTO_ecdhe_key_create ();
3206 * Change the tunnel's connection state.
3208 * @param t Tunnel whose connection state to change.
3209 * @param cstate New connection state.
3212 GCT_change_cstate (struct CadetTunnel* t, enum CadetTunnelCState cstate)
3216 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel %s cstate %s => %s\n",
3217 GCP_2s (t->peer), cstate2s (t->cstate), cstate2s (cstate));
3218 if (myid != GCP_get_short_id (t->peer) &&
3219 CADET_TUNNEL_READY != t->cstate &&
3220 CADET_TUNNEL_READY == cstate)
3223 if (CADET_TUNNEL_KEY_OK == t->estate)
3225 LOG (GNUNET_ERROR_TYPE_DEBUG, " cstate triggered send queued data\n");
3226 send_queued_data (t);
3228 else if (CADET_TUNNEL_KEY_UNINITIALIZED == t->estate)
3230 LOG (GNUNET_ERROR_TYPE_DEBUG, " cstate triggered kx\n");
3235 LOG (GNUNET_ERROR_TYPE_DEBUG, "estate %s\n", estate2s (t->estate));
3240 if (CADET_TUNNEL_READY == cstate
3241 && CONNECTIONS_PER_TUNNEL <= GCT_count_connections (t))
3243 LOG (GNUNET_ERROR_TYPE_DEBUG, " cstate triggered stop dht\n");
3244 GCP_stop_search (t->peer);
3250 * Change the tunnel encryption state.
3252 * @param t Tunnel whose encryption state to change, or NULL.
3253 * @param state New encryption state.
3256 GCT_change_estate (struct CadetTunnel* t, enum CadetTunnelEState state)
3258 enum CadetTunnelEState old;
3265 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel %s estate was %s\n",
3266 GCP_2s (t->peer), estate2s (old));
3267 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel %s estate is now %s\n",
3268 GCP_2s (t->peer), estate2s (t->estate));
3270 /* Send queued data if enc state changes to OK */
3271 if (myid != GCP_get_short_id (t->peer) &&
3272 CADET_TUNNEL_KEY_OK != old && CADET_TUNNEL_KEY_OK == t->estate)
3274 send_queued_data (t);
3280 * @brief Check if tunnel has too many connections, and remove one if necessary.
3282 * Currently this means the newest connection, unless it is a direct one.
3283 * Implemented as a task to avoid freeing a connection that is in the middle
3284 * of being created/processed.
3286 * @param cls Closure (Tunnel to check).
3287 * @param tc Task context.
3290 trim_connections (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
3292 struct CadetTunnel *t = cls;
3294 t->trim_connections_task = NULL;
3296 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
3299 if (GCT_count_connections (t) > 2 * CONNECTIONS_PER_TUNNEL)
3301 struct CadetTConnection *iter;
3302 struct CadetTConnection *c;
3304 for (c = iter = t->connection_head; NULL != iter; iter = iter->next)
3306 if ((iter->created.abs_value_us > c->created.abs_value_us)
3307 && GNUNET_NO == GCC_is_direct (iter->c))
3314 LOG (GNUNET_ERROR_TYPE_DEBUG, "Too many connections on tunnel %s\n",
3316 LOG (GNUNET_ERROR_TYPE_DEBUG, "Destroying connection %s\n",
3329 * Add a connection to a tunnel.
3332 * @param c Connection.
3335 GCT_add_connection (struct CadetTunnel *t, struct CadetConnection *c)
3337 struct CadetTConnection *aux;
3339 GNUNET_assert (NULL != c);
3341 LOG (GNUNET_ERROR_TYPE_DEBUG, "add connection %s\n", GCC_2s (c));
3342 LOG (GNUNET_ERROR_TYPE_DEBUG, " to tunnel %s\n", GCT_2s (t));
3343 for (aux = t->connection_head; aux != NULL; aux = aux->next)
3347 aux = GNUNET_new (struct CadetTConnection);
3349 aux->created = GNUNET_TIME_absolute_get ();
3351 GNUNET_CONTAINER_DLL_insert (t->connection_head, t->connection_tail, aux);
3353 if (CADET_TUNNEL_SEARCHING == t->cstate)
3354 GCT_change_cstate (t, CADET_TUNNEL_WAITING);
3356 if (NULL != t->trim_connections_task)
3357 t->trim_connections_task = GNUNET_SCHEDULER_add_now (&trim_connections, t);
3362 * Remove a connection from a tunnel.
3365 * @param c Connection.
3368 GCT_remove_connection (struct CadetTunnel *t,
3369 struct CadetConnection *c)
3371 struct CadetTConnection *aux;
3372 struct CadetTConnection *next;
3375 LOG (GNUNET_ERROR_TYPE_DEBUG, "Removing connection %s from tunnel %s\n",
3376 GCC_2s (c), GCT_2s (t));
3377 for (aux = t->connection_head; aux != NULL; aux = next)
3382 GNUNET_CONTAINER_DLL_remove (t->connection_head, t->connection_tail, aux);
3387 conns = GCT_count_connections (t);
3389 && NULL == t->destroy_task
3390 && CADET_TUNNEL_SHUTDOWN != t->cstate
3391 && GNUNET_NO == shutting_down)
3393 if (0 == GCT_count_any_connections (t))
3394 GCT_change_cstate (t, CADET_TUNNEL_SEARCHING);
3396 GCT_change_cstate (t, CADET_TUNNEL_WAITING);
3399 /* Start new connections if needed */
3400 if (CONNECTIONS_PER_TUNNEL > conns
3401 && NULL == t->destroy_task
3402 && CADET_TUNNEL_SHUTDOWN != t->cstate
3403 && GNUNET_NO == shutting_down)
3405 LOG (GNUNET_ERROR_TYPE_DEBUG, " too few connections, getting new ones\n");
3406 GCP_connect (t->peer); /* Will change cstate to WAITING when possible */
3410 /* If not marked as ready, no change is needed */
3411 if (CADET_TUNNEL_READY != t->cstate)
3414 /* Check if any connection is ready to maintain cstate */
3415 for (aux = t->connection_head; aux != NULL; aux = aux->next)
3416 if (CADET_CONNECTION_READY == GCC_get_state (aux->c))
3422 * Add a channel to a tunnel.
3425 * @param ch Channel.
3428 GCT_add_channel (struct CadetTunnel *t, struct CadetChannel *ch)
3430 struct CadetTChannel *aux;
3432 GNUNET_assert (NULL != ch);
3434 LOG (GNUNET_ERROR_TYPE_DEBUG, "Adding channel %p to tunnel %p\n", ch, t);
3436 for (aux = t->channel_head; aux != NULL; aux = aux->next)
3438 LOG (GNUNET_ERROR_TYPE_DEBUG, " already there %p\n", aux->ch);
3443 aux = GNUNET_new (struct CadetTChannel);
3445 LOG (GNUNET_ERROR_TYPE_DEBUG, " adding %p to %p\n", aux, t->channel_head);
3446 GNUNET_CONTAINER_DLL_insert_tail (t->channel_head, t->channel_tail, aux);
3448 if (NULL != t->destroy_task)
3450 GNUNET_SCHEDULER_cancel (t->destroy_task);
3451 t->destroy_task = NULL;
3452 LOG (GNUNET_ERROR_TYPE_DEBUG, " undo destroy!\n");
3458 * Remove a channel from a tunnel.
3461 * @param ch Channel.
3464 GCT_remove_channel (struct CadetTunnel *t, struct CadetChannel *ch)
3466 struct CadetTChannel *aux;
3468 LOG (GNUNET_ERROR_TYPE_DEBUG, "Removing channel %p from tunnel %p\n", ch, t);
3469 for (aux = t->channel_head; aux != NULL; aux = aux->next)
3473 LOG (GNUNET_ERROR_TYPE_DEBUG, " found! %s\n", GCCH_2s (ch));
3474 GNUNET_CONTAINER_DLL_remove (t->channel_head, t->channel_tail, aux);
3483 * Search for a channel by global ID.
3485 * @param t Tunnel containing the channel.
3486 * @param chid Public channel number.
3488 * @return channel handler, NULL if doesn't exist
3490 struct CadetChannel *
3491 GCT_get_channel (struct CadetTunnel *t, CADET_ChannelNumber chid)
3493 struct CadetTChannel *iter;
3498 for (iter = t->channel_head; NULL != iter; iter = iter->next)
3500 if (GCCH_get_id (iter->ch) == chid)
3504 return NULL == iter ? NULL : iter->ch;
3509 * @brief Destroy a tunnel and free all resources.
3511 * Should only be called a while after the tunnel has been marked as destroyed,
3512 * in case there is a new channel added to the same peer shortly after marking
3513 * the tunnel. This way we avoid a new public key handshake.
3515 * @param cls Closure (tunnel to destroy).
3516 * @param tc Task context.
3519 delayed_destroy (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
3521 struct CadetTunnel *t = cls;
3522 struct CadetTConnection *iter;
3524 LOG (GNUNET_ERROR_TYPE_DEBUG, "delayed destroying tunnel %p\n", t);
3525 if (0 != (GNUNET_SCHEDULER_REASON_SHUTDOWN & tc->reason))
3527 LOG (GNUNET_ERROR_TYPE_WARNING,
3528 "Not destroying tunnel, due to shutdown. "
3529 "Tunnel at %p should have been freed by GCT_shutdown\n", t);
3532 t->destroy_task = NULL;
3533 t->cstate = CADET_TUNNEL_SHUTDOWN;
3535 for (iter = t->connection_head; NULL != iter; iter = iter->next)
3537 GCC_send_destroy (iter->c);
3544 * Tunnel is empty: destroy it.
3546 * Notifies all connections about the destruction.
3548 * @param t Tunnel to destroy.
3551 GCT_destroy_empty (struct CadetTunnel *t)
3553 if (GNUNET_YES == shutting_down)
3554 return; /* Will be destroyed immediately anyway */
3556 if (NULL != t->destroy_task)
3558 LOG (GNUNET_ERROR_TYPE_WARNING,
3559 "Tunnel %s is already scheduled for destruction. Tunnel debug dump:\n",
3561 GCT_debug (t, GNUNET_ERROR_TYPE_WARNING);
3563 /* should never happen, tunnel can only become empty once, and the
3564 * task identifier should be NO_TASK (cleaned when the tunnel was created
3565 * or became un-empty)
3570 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel %s empty: scheduling destruction\n",
3573 // FIXME make delay a config option
3574 t->destroy_task = GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_MINUTES,
3575 &delayed_destroy, t);
3576 LOG (GNUNET_ERROR_TYPE_DEBUG, "Scheduled destroy of %p as %llu\n",
3577 t, t->destroy_task);
3582 * Destroy tunnel if empty (no more channels).
3584 * @param t Tunnel to destroy if empty.
3587 GCT_destroy_if_empty (struct CadetTunnel *t)
3589 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel %s destroy if empty\n", GCT_2s (t));
3590 if (0 < GCT_count_channels (t))
3593 GCT_destroy_empty (t);
3598 * Destroy the tunnel.
3600 * This function does not generate any warning traffic to clients or peers.
3603 * Cancel messages belonging to this tunnel queued to neighbors.
3604 * Free any allocated resources linked to the tunnel.
3606 * @param t The tunnel to destroy.
3609 GCT_destroy (struct CadetTunnel *t)
3611 struct CadetTConnection *iter_c;
3612 struct CadetTConnection *next_c;
3613 struct CadetTChannel *iter_ch;
3614 struct CadetTChannel *next_ch;
3619 LOG (GNUNET_ERROR_TYPE_DEBUG, "destroying tunnel %s\n", GCP_2s (t->peer));
3621 GNUNET_break (GNUNET_YES ==
3622 GNUNET_CONTAINER_multipeermap_remove (tunnels,
3623 GCP_get_id (t->peer), t));
3625 for (iter_c = t->connection_head; NULL != iter_c; iter_c = next_c)
3627 next_c = iter_c->next;
3628 GCC_destroy (iter_c->c);
3630 for (iter_ch = t->channel_head; NULL != iter_ch; iter_ch = next_ch)
3632 next_ch = iter_ch->next;
3633 GCCH_destroy (iter_ch->ch);
3634 /* Should only happen on shutdown, but it's ok. */
3637 if (NULL != t->destroy_task)
3639 LOG (GNUNET_ERROR_TYPE_DEBUG, "cancelling dest: %llX\n", t->destroy_task);
3640 GNUNET_SCHEDULER_cancel (t->destroy_task);
3641 t->destroy_task = NULL;
3644 if (NULL != t->trim_connections_task)
3646 LOG (GNUNET_ERROR_TYPE_DEBUG, "cancelling trim: %llX\n",
3647 t->trim_connections_task);
3648 GNUNET_SCHEDULER_cancel (t->trim_connections_task);
3649 t->trim_connections_task = NULL;
3652 GNUNET_STATISTICS_update (stats, "# tunnels", -1, GNUNET_NO);
3653 GCP_set_tunnel (t->peer, NULL);
3655 if (NULL != t->rekey_task)
3657 GNUNET_SCHEDULER_cancel (t->rekey_task);
3658 t->rekey_task = NULL;
3660 if (NULL != t->kx_ctx)
3662 if (NULL != t->kx_ctx->finish_task)
3663 GNUNET_SCHEDULER_cancel (t->kx_ctx->finish_task);
3664 GNUNET_free (t->kx_ctx);
3675 * @brief Use the given path for the tunnel.
3676 * Update the next and prev hops (and RCs).
3677 * (Re)start the path refresh in case the tunnel is locally owned.
3679 * @param t Tunnel to update.
3680 * @param p Path to use.
3682 * @return Connection created.
3684 struct CadetConnection *
3685 GCT_use_path (struct CadetTunnel *t, struct CadetPeerPath *p)
3687 struct CadetConnection *c;
3688 struct GNUNET_CADET_Hash cid;
3689 unsigned int own_pos;
3691 if (NULL == t || NULL == p)
3697 if (CADET_TUNNEL_SHUTDOWN == t->cstate)
3703 for (own_pos = 0; own_pos < p->length; own_pos++)
3705 if (p->peers[own_pos] == myid)
3708 if (own_pos >= p->length)
3710 GNUNET_break_op (0);
3714 GNUNET_CRYPTO_random_block (GNUNET_CRYPTO_QUALITY_NONCE, &cid, sizeof (cid));
3715 c = GCC_new (&cid, t, p, own_pos);
3718 /* Path was flawed */
3721 GCT_add_connection (t, c);
3727 * Count all created connections of a tunnel. Not necessarily ready connections!
3729 * @param t Tunnel on which to count.
3731 * @return Number of connections created, either being established or ready.
3734 GCT_count_any_connections (struct CadetTunnel *t)
3736 struct CadetTConnection *iter;
3742 for (count = 0, iter = t->connection_head; NULL != iter; iter = iter->next)
3750 * Count established (ready) connections of a tunnel.
3752 * @param t Tunnel on which to count.
3754 * @return Number of connections.
3757 GCT_count_connections (struct CadetTunnel *t)
3759 struct CadetTConnection *iter;
3765 for (count = 0, iter = t->connection_head; NULL != iter; iter = iter->next)
3766 if (CADET_CONNECTION_READY == GCC_get_state (iter->c))
3774 * Count channels of a tunnel.
3776 * @param t Tunnel on which to count.
3778 * @return Number of channels.
3781 GCT_count_channels (struct CadetTunnel *t)
3783 struct CadetTChannel *iter;
3786 for (count = 0, iter = t->channel_head;
3788 iter = iter->next, count++) /* skip */;
3795 * Get the connectivity state of a tunnel.
3799 * @return Tunnel's connectivity state.
3801 enum CadetTunnelCState
3802 GCT_get_cstate (struct CadetTunnel *t)
3807 return (enum CadetTunnelCState) -1;
3814 * Get the encryption state of a tunnel.
3818 * @return Tunnel's encryption state.
3820 enum CadetTunnelEState
3821 GCT_get_estate (struct CadetTunnel *t)
3826 return (enum CadetTunnelEState) -1;
3832 * Get the maximum buffer space for a tunnel towards a local client.
3836 * @return Biggest buffer space offered by any channel in the tunnel.
3839 GCT_get_channels_buffer (struct CadetTunnel *t)
3841 struct CadetTChannel *iter;
3842 unsigned int buffer;
3843 unsigned int ch_buf;
3845 if (NULL == t->channel_head)
3847 /* Probably getting buffer for a channel create/handshake. */
3848 LOG (GNUNET_ERROR_TYPE_DEBUG, " no channels, allow max\n");
3853 for (iter = t->channel_head; NULL != iter; iter = iter->next)
3855 ch_buf = get_channel_buffer (iter);
3856 if (ch_buf > buffer)
3864 * Get the total buffer space for a tunnel for P2P traffic.
3868 * @return Buffer space offered by all connections in the tunnel.
3871 GCT_get_connections_buffer (struct CadetTunnel *t)
3873 struct CadetTConnection *iter;
3874 unsigned int buffer;
3876 if (GNUNET_NO == is_ready (t))
3878 if (count_queued_data (t) > 3)
3885 for (iter = t->connection_head; NULL != iter; iter = iter->next)
3887 if (GCC_get_state (iter->c) != CADET_CONNECTION_READY)
3891 buffer += get_connection_buffer (iter);
3899 * Get the tunnel's destination.
3903 * @return ID of the destination peer.
3905 const struct GNUNET_PeerIdentity *
3906 GCT_get_destination (struct CadetTunnel *t)
3908 return GCP_get_id (t->peer);
3913 * Get the tunnel's next free global channel ID.
3917 * @return GID of a channel free to use.
3920 GCT_get_next_chid (struct CadetTunnel *t)
3922 CADET_ChannelNumber chid;
3923 CADET_ChannelNumber mask;
3926 /* Set bit 30 depending on the ID relationship. Bit 31 is always 0 for GID.
3927 * If our ID is bigger or loopback tunnel, start at 0, bit 30 = 0
3928 * If peer's ID is bigger, start at 0x4... bit 30 = 1
3930 result = GNUNET_CRYPTO_cmp_peer_identity (&my_full_id, GCP_get_id (t->peer));
3935 t->next_chid |= mask;
3937 while (NULL != GCT_get_channel (t, t->next_chid))
3939 LOG (GNUNET_ERROR_TYPE_DEBUG, "Channel %u exists...\n", t->next_chid);
3940 t->next_chid = (t->next_chid + 1) & ~GNUNET_CADET_LOCAL_CHANNEL_ID_CLI;
3941 t->next_chid |= mask;
3943 chid = t->next_chid;
3944 t->next_chid = (t->next_chid + 1) & ~GNUNET_CADET_LOCAL_CHANNEL_ID_CLI;
3945 t->next_chid |= mask;
3952 * Send ACK on one or more channels due to buffer in connections.
3954 * @param t Channel which has some free buffer space.
3957 GCT_unchoke_channels (struct CadetTunnel *t)
3959 struct CadetTChannel *iter;
3960 unsigned int buffer;
3961 unsigned int channels = GCT_count_channels (t);
3962 unsigned int choked_n;
3963 struct CadetChannel *choked[channels];
3965 LOG (GNUNET_ERROR_TYPE_DEBUG, "GCT_unchoke_channels on %s\n", GCT_2s (t));
3966 LOG (GNUNET_ERROR_TYPE_DEBUG, " head: %p\n", t->channel_head);
3967 if (NULL != t->channel_head)
3968 LOG (GNUNET_ERROR_TYPE_DEBUG, " head ch: %p\n", t->channel_head->ch);
3970 /* Get buffer space */
3971 buffer = GCT_get_connections_buffer (t);
3977 /* Count and remember choked channels */
3979 for (iter = t->channel_head; NULL != iter; iter = iter->next)
3981 if (GNUNET_NO == get_channel_allowed (iter))
3983 choked[choked_n++] = iter->ch;
3987 /* Unchoke random channels */
3988 while (0 < buffer && 0 < choked_n)
3990 unsigned int r = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK,
3992 GCCH_allow_client (choked[r], GCCH_is_origin (choked[r], GNUNET_YES));
3995 choked[r] = choked[choked_n];
4001 * Send ACK on one or more connections due to buffer space to the client.
4003 * Iterates all connections of the tunnel and sends ACKs appropriately.
4008 GCT_send_connection_acks (struct CadetTunnel *t)
4010 struct CadetTConnection *iter;
4013 uint32_t allow_per_connection;
4015 unsigned int buffer;
4017 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel send connection ACKs on %s\n",
4026 if (CADET_TUNNEL_READY != t->cstate)
4029 buffer = GCT_get_channels_buffer (t);
4030 LOG (GNUNET_ERROR_TYPE_DEBUG, " buffer %u\n", buffer);
4032 /* Count connections, how many messages are already allowed */
4033 cs = GCT_count_connections (t);
4034 for (allowed = 0, iter = t->connection_head; NULL != iter; iter = iter->next)
4036 allowed += get_connection_allowed (iter);
4038 LOG (GNUNET_ERROR_TYPE_DEBUG, " allowed %u\n", allowed);
4040 /* Make sure there is no overflow */
4041 if (allowed > buffer)
4044 /* Authorize connections to send more data */
4045 to_allow = buffer - allowed;
4047 for (iter = t->connection_head;
4048 NULL != iter && to_allow > 0;
4051 if (CADET_CONNECTION_READY != GCC_get_state (iter->c)
4052 || get_connection_allowed (iter) > 64 / 3)
4056 allow_per_connection = to_allow/cs;
4057 to_allow -= allow_per_connection;
4059 GCC_allow (iter->c, allow_per_connection,
4060 GCC_is_origin (iter->c, GNUNET_NO));
4065 /* Since we don't allow if it's allowed to send 64/3, this can happen. */
4066 LOG (GNUNET_ERROR_TYPE_DEBUG, " reminding to_allow: %u\n", to_allow);
4072 * Cancel a previously sent message while it's in the queue.
4074 * ONLY can be called before the continuation given to the send function
4075 * is called. Once the continuation is called, the message is no longer in the
4078 * @param q Handle to the queue.
4081 GCT_cancel (struct CadetTunnelQueue *q)
4086 /* tun_message_sent() will be called and free q */
4088 else if (NULL != q->tqd)
4090 unqueue_data (q->tqd);
4092 if (NULL != q->cont)
4093 q->cont (q->cont_cls, NULL, q, 0, 0);
4104 * Sends an already built message on a tunnel, encrypting it and
4105 * choosing the best connection if not provided.
4107 * @param message Message to send. Function modifies it.
4108 * @param t Tunnel on which this message is transmitted.
4109 * @param c Connection to use (autoselect if NULL).
4110 * @param force Force the tunnel to take the message (buffer overfill).
4111 * @param cont Continuation to call once message is really sent.
4112 * @param cont_cls Closure for @c cont.
4114 * @return Handle to cancel message. NULL if @c cont is NULL.
4116 struct CadetTunnelQueue *
4117 GCT_send_prebuilt_message (const struct GNUNET_MessageHeader *message,
4118 struct CadetTunnel *t, struct CadetConnection *c,
4119 int force, GCT_sent cont, void *cont_cls)
4121 return send_prebuilt_message (message, t, c, force, cont, cont_cls, NULL);
4126 * Send an Axolotl KX message.
4128 * @param t Tunnel on which to send it.
4131 GCT_send_ax_kx (struct CadetTunnel *t)
4133 struct GNUNET_CADET_AX_KX msg;
4135 LOG (GNUNET_ERROR_TYPE_INFO, "===> AX_KX for %s\n", GCT_2s (t));
4136 if (NULL != t->ephm_h)
4138 LOG (GNUNET_ERROR_TYPE_INFO, " already queued\n");
4142 msg.header.size = htons (sizeof (msg));
4143 msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_AX_KX);
4144 msg.permanent_key = ax_identity.permanent_key;
4145 msg.purpose = ax_identity.purpose;
4146 msg.signature = ax_identity.signature;
4147 GNUNET_CRYPTO_ecdhe_key_get_public (t->ax->kx_0, &msg.ephemeral_key);
4148 GNUNET_CRYPTO_ecdhe_key_get_public (t->ax->DHRs, &msg.ratchet_key);
4150 t->ephm_h = send_kx (t, &msg.header);
4151 GCT_change_estate (t, CADET_TUNNEL_KEY_SENT);
4156 * Sends an already built and encrypted message on a tunnel, choosing the best
4157 * connection. Useful for re-queueing messages queued on a destroyed connection.
4159 * @param message Message to send. Function modifies it.
4160 * @param t Tunnel on which this message is transmitted.
4163 GCT_resend_message (const struct GNUNET_MessageHeader *message,
4164 struct CadetTunnel *t)
4166 struct CadetConnection *c;
4169 c = tunnel_get_connection (t);
4172 /* TODO queue in tunnel, marked as encrypted */
4173 LOG (GNUNET_ERROR_TYPE_DEBUG, "No connection available, dropping.\n");
4176 fwd = GCC_is_origin (c, GNUNET_YES);
4177 GNUNET_break (NULL == GCC_send_prebuilt_message (message, 0, 0, c, fwd,
4178 GNUNET_YES, NULL, NULL));
4183 * Is the tunnel directed towards the local peer?
4187 * @return #GNUNET_YES if it is loopback.
4190 GCT_is_loopback (const struct CadetTunnel *t)
4192 return (myid == GCP_get_short_id (t->peer));
4197 * Is the tunnel this path already?
4202 * @return #GNUNET_YES a connection uses this path.
4205 GCT_is_path_used (const struct CadetTunnel *t, const struct CadetPeerPath *p)
4207 struct CadetTConnection *iter;
4209 for (iter = t->connection_head; NULL != iter; iter = iter->next)
4210 if (path_equivalent (GCC_get_path (iter->c), p))
4218 * Get a cost of a path for a tunnel considering existing connections.
4221 * @param path Candidate path.
4223 * @return Cost of the path (path length + number of overlapping nodes)
4226 GCT_get_path_cost (const struct CadetTunnel *t,
4227 const struct CadetPeerPath *path)
4229 struct CadetTConnection *iter;
4230 const struct CadetPeerPath *aux;
4231 unsigned int overlap;
4239 GNUNET_assert (NULL != t);
4241 for (i = 0; i < path->length; i++)
4243 for (iter = t->connection_head; NULL != iter; iter = iter->next)
4245 aux = GCC_get_path (iter->c);
4249 for (j = 0; j < aux->length; j++)
4251 if (path->peers[i] == aux->peers[j])
4259 return path->length + overlap;
4264 * Get the static string for the peer this tunnel is directed.
4268 * @return Static string the destination peer's ID.
4271 GCT_2s (const struct CadetTunnel *t)
4276 return GCP_2s (t->peer);
4280 /******************************************************************************/
4281 /***************************** INFO/DEBUG *******************************/
4282 /******************************************************************************/
4285 ax_debug (const struct CadetTunnelAxolotl *ax, enum GNUNET_ErrorType level)
4287 struct GNUNET_CRYPTO_EcdhePublicKey pub;
4288 struct CadetTunnelSkippedKey *iter;
4291 LOG2 (level, "TTT RK\t %s\n",
4292 GNUNET_h2s ((struct GNUNET_HashCode *) &ax->RK));
4294 LOG2 (level, "TTT HKs\t %s\n",
4295 GNUNET_h2s ((struct GNUNET_HashCode *) &ax->HKs));
4296 LOG2 (level, "TTT HKr\t %s\n",
4297 GNUNET_h2s ((struct GNUNET_HashCode *) &ax->HKr));
4298 LOG2 (level, "TTT NHKs\t %s\n",
4299 GNUNET_h2s ((struct GNUNET_HashCode *) &ax->NHKs));
4300 LOG2 (level, "TTT NHKr\t %s\n",
4301 GNUNET_h2s ((struct GNUNET_HashCode *) &ax->NHKr));
4303 LOG2 (level, "TTT CKs\t %s\n",
4304 GNUNET_h2s ((struct GNUNET_HashCode *) &ax->CKs));
4305 LOG2 (level, "TTT CKr\t %s\n",
4306 GNUNET_h2s ((struct GNUNET_HashCode *) &ax->CKr));
4308 GNUNET_CRYPTO_ecdhe_key_get_public (ax_key, &pub);
4309 LOG2 (level, "TTT DHIs\t %s\n",
4310 GNUNET_h2s ((struct GNUNET_HashCode *) &pub));
4311 LOG2 (level, "TTT DHIr\t %s\n",
4312 GNUNET_h2s ((struct GNUNET_HashCode *) &ax->DHIr));
4313 GNUNET_CRYPTO_ecdhe_key_get_public (ax->DHRs, &pub);
4314 LOG2 (level, "TTT DHRs\t %s\n",
4315 GNUNET_h2s ((struct GNUNET_HashCode *) &pub));
4316 LOG2 (level, "TTT DHRr\t %s\n",
4317 GNUNET_h2s ((struct GNUNET_HashCode *) &ax->DHRr));
4319 LOG2 (level, "TTT Nr\t %u\tNs\t%u\n", ax->Nr, ax->Ns);
4320 LOG2 (level, "TTT PNs\t %u\tSkipped\t%u\n", ax->PNs, ax->skipped);
4321 LOG2 (level, "TTT Ratchet\t%u\n", ax->ratchet_flag);
4323 for (iter = ax->skipped_head; NULL != iter; iter = iter->next)
4325 LOG2 (level, "TTT HK\t %s\n",
4326 GNUNET_h2s ((struct GNUNET_HashCode *) &iter->HK));
4327 LOG2 (level, "TTT MK\t %s\n",
4328 GNUNET_h2s ((struct GNUNET_HashCode *) &iter->MK));
4333 * Log all possible info about the tunnel state.
4335 * @param t Tunnel to debug.
4336 * @param level Debug level to use.
4339 GCT_debug (const struct CadetTunnel *t, enum GNUNET_ErrorType level)
4341 struct CadetTChannel *iterch;
4342 struct CadetTConnection *iterc;
4345 do_log = GNUNET_get_log_call_status (level & (~GNUNET_ERROR_TYPE_BULK),
4347 __FILE__, __FUNCTION__, __LINE__);
4351 LOG2 (level, "TTT DEBUG TUNNEL TOWARDS %s\n", GCT_2s (t));
4352 LOG2 (level, "TTT cstate %s, estate %s\n",
4353 cstate2s (t->cstate), estate2s (t->estate));
4354 LOG2 (level, "TTT kx_ctx %p, rekey_task %u, finish task %u\n",
4355 t->kx_ctx, t->rekey_task, t->kx_ctx ? t->kx_ctx->finish_task : 0);
4356 #if DUMP_KEYS_TO_STDERR
4357 if (CADET_Axolotl == t->enc_type)
4359 ax_debug (t->ax, level);
4363 LOG2 (level, "TTT my EPHM\t %s\n",
4364 GNUNET_h2s ((struct GNUNET_HashCode *) &otr_kx_msg.ephemeral_key));
4365 LOG2 (level, "TTT peers EPHM:\t %s\n",
4366 GNUNET_h2s ((struct GNUNET_HashCode *) &t->peers_ephemeral_key));
4367 LOG2 (level, "TTT ENC key:\t %s\n",
4368 GNUNET_h2s ((struct GNUNET_HashCode *) &t->e_key));
4369 LOG2 (level, "TTT DEC key:\t %s\n",
4370 GNUNET_h2s ((struct GNUNET_HashCode *) &t->d_key));
4373 LOG2 (level, "TTT OLD ENC key:\t %s\n",
4374 GNUNET_h2s ((struct GNUNET_HashCode *) &t->kx_ctx->e_key_old));
4375 LOG2 (level, "TTT OLD DEC key:\t %s\n",
4376 GNUNET_h2s ((struct GNUNET_HashCode *) &t->kx_ctx->d_key_old));
4380 LOG2 (level, "TTT tq_head %p, tq_tail %p\n", t->tq_head, t->tq_tail);
4381 LOG2 (level, "TTT destroy %u\n", t->destroy_task);
4383 LOG2 (level, "TTT channels:\n");
4384 for (iterch = t->channel_head; NULL != iterch; iterch = iterch->next)
4386 LOG2 (level, "TTT - %s\n", GCCH_2s (iterch->ch));
4389 LOG2 (level, "TTT connections:\n");
4390 for (iterc = t->connection_head; NULL != iterc; iterc = iterc->next)
4392 GCC_debug (iterc->c, level);
4395 LOG2 (level, "TTT DEBUG TUNNEL END\n");
4400 * Iterate all tunnels.
4402 * @param iter Iterator.
4403 * @param cls Closure for @c iter.
4406 GCT_iterate_all (GNUNET_CONTAINER_PeerMapIterator iter, void *cls)
4408 GNUNET_CONTAINER_multipeermap_iterate (tunnels, iter, cls);
4413 * Count all tunnels.
4415 * @return Number of tunnels to remote peers kept by this peer.
4418 GCT_count_all (void)
4420 return GNUNET_CONTAINER_multipeermap_size (tunnels);
4425 * Iterate all connections of a tunnel.
4427 * @param t Tunnel whose connections to iterate.
4428 * @param iter Iterator.
4429 * @param cls Closure for @c iter.
4432 GCT_iterate_connections (struct CadetTunnel *t, GCT_conn_iter iter, void *cls)
4434 struct CadetTConnection *ct;
4436 for (ct = t->connection_head; NULL != ct; ct = ct->next)
4442 * Iterate all channels of a tunnel.
4444 * @param t Tunnel whose channels to iterate.
4445 * @param iter Iterator.
4446 * @param cls Closure for @c iter.
4449 GCT_iterate_channels (struct CadetTunnel *t, GCT_chan_iter iter, void *cls)
4451 struct CadetTChannel *cht;
4453 for (cht = t->channel_head; NULL != cht; cht = cht->next)
4454 iter (cls, cht->ch);