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 * @brief Resend the AX KX until we complete the handshake.
2013 * @param cls Closure (tunnel).
2014 * @param tc Task context.
2017 ax_kx_resend (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
2019 struct CadetTunnel *t = cls;
2021 t->rekey_task = NULL;
2023 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
2026 if (CADET_TUNNEL_KEY_OK == t->estate)
2029 GCT_send_ax_kx (t, GNUNET_YES);
2034 * Callback called when a queued message is sent.
2036 * @param cls Closure.
2037 * @param c Connection this message was on.
2038 * @param type Type of message sent.
2039 * @param fwd Was this a FWD going message?
2040 * @param size Size of the message.
2043 ephm_sent (void *cls,
2044 struct CadetConnection *c,
2045 struct CadetConnectionQueue *q,
2046 uint16_t type, int fwd, size_t size)
2048 struct CadetTunnel *t = cls;
2049 LOG (GNUNET_ERROR_TYPE_DEBUG, "ephemeral sent %s\n", GC_m2s (type));
2053 if (CADET_TUNNEL_KEY_OK == t->estate)
2056 if (CADET_Axolotl == t->enc_type && CADET_TUNNEL_KEY_OK != t->estate)
2058 if (NULL != t->rekey_task)
2061 GNUNET_SCHEDULER_cancel (t->rekey_task);
2063 t->rekey_task = GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_SECONDS,
2070 * Callback called when a queued message is sent.
2072 * @param cls Closure.
2073 * @param c Connection this message was on.
2074 * @param type Type of message sent.
2075 * @param fwd Was this a FWD going message?
2076 * @param size Size of the message.
2079 pong_sent (void *cls,
2080 struct CadetConnection *c,
2081 struct CadetConnectionQueue *q,
2082 uint16_t type, int fwd, size_t size)
2084 struct CadetTunnel *t = cls;
2085 LOG (GNUNET_ERROR_TYPE_DEBUG, "pong_sent %s\n", GC_m2s (type));
2092 * Sends key exchange message on a tunnel, choosing the best connection.
2093 * Should not be called on loopback tunnels.
2095 * @param t Tunnel on which this message is transmitted.
2096 * @param message Message to send. Function modifies it.
2098 * @return Handle to the message in the connection queue.
2100 static struct CadetConnectionQueue *
2101 send_kx (struct CadetTunnel *t,
2102 const struct GNUNET_MessageHeader *message)
2104 struct CadetConnection *c;
2105 struct GNUNET_CADET_KX *msg;
2106 size_t size = ntohs (message->size);
2107 char cbuf[sizeof (struct GNUNET_CADET_KX) + size];
2112 LOG (GNUNET_ERROR_TYPE_DEBUG, "GMT KX on Tunnel %s\n", GCT_2s (t));
2114 /* Avoid loopback. */
2115 if (GCT_is_loopback (t))
2120 type = ntohs (message->type);
2122 /* Even if tunnel is "being destroyed", send anyway.
2123 * Could be a response to a rekey initiated by remote peer,
2124 * who is trying to create a new channel!
2127 /* Must have a connection, or be looking for one. */
2128 if (NULL == t->connection_head)
2130 LOG (GNUNET_ERROR_TYPE_DEBUG, "%s with no connection\n", GC_m2s (type));
2131 if (CADET_TUNNEL_SEARCHING != t->cstate)
2134 GCT_debug (t, GNUNET_ERROR_TYPE_ERROR);
2135 GCP_debug (t->peer, GNUNET_ERROR_TYPE_ERROR);
2140 msg = (struct GNUNET_CADET_KX *) cbuf;
2141 msg->header.type = htons (GNUNET_MESSAGE_TYPE_CADET_KX);
2142 msg->header.size = htons (sizeof (struct GNUNET_CADET_KX) + size);
2143 c = tunnel_get_connection (t);
2146 if (NULL == t->destroy_task && CADET_TUNNEL_READY == t->cstate)
2149 GCT_debug (t, GNUNET_ERROR_TYPE_ERROR);
2155 case GNUNET_MESSAGE_TYPE_CADET_KX_EPHEMERAL:
2156 case GNUNET_MESSAGE_TYPE_CADET_AX_KX:
2157 GNUNET_assert (NULL == t->ephm_h);
2160 case GNUNET_MESSAGE_TYPE_CADET_KX_PONG:
2161 GNUNET_assert (NULL == t->pong_h);
2166 LOG (GNUNET_ERROR_TYPE_DEBUG, "unkown type %s\n", GC_m2s (type));
2169 memcpy (&msg[1], message, size);
2171 fwd = GCC_is_origin (c, GNUNET_YES);
2173 return GCC_send_prebuilt_message (&msg->header, type, 0, c,
2180 * Send the ephemeral key on a tunnel.
2182 * @param t Tunnel on which to send the key.
2185 send_ephemeral (struct CadetTunnel *t)
2187 LOG (GNUNET_ERROR_TYPE_INFO, "===> EPHM for %s\n", GCT_2s (t));
2188 if (NULL != t->ephm_h)
2190 LOG (GNUNET_ERROR_TYPE_INFO, " already queued\n");
2194 otr_kx_msg.sender_status = htonl (t->estate);
2195 otr_kx_msg.iv = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX);
2196 otr_kx_msg.nonce = t->kx_ctx->challenge;
2197 LOG (GNUNET_ERROR_TYPE_DEBUG, " send nonce c %u\n", otr_kx_msg.nonce);
2198 t_encrypt (t, &otr_kx_msg.nonce, &otr_kx_msg.nonce,
2199 ping_encryption_size(), otr_kx_msg.iv, GNUNET_YES);
2200 LOG (GNUNET_ERROR_TYPE_DEBUG, " send nonce e %u\n", otr_kx_msg.nonce);
2201 t->ephm_h = send_kx (t, &otr_kx_msg.header);
2206 * Send a pong message on a tunnel.
2208 * @param t Tunnel on which to send the pong.
2209 * @param challenge Value sent in the ping that we have to send back.
2212 send_pong (struct CadetTunnel *t, uint32_t challenge)
2214 struct GNUNET_CADET_KX_Pong msg;
2216 LOG (GNUNET_ERROR_TYPE_INFO, "===> PONG for %s\n", GCT_2s (t));
2217 if (NULL != t->pong_h)
2219 LOG (GNUNET_ERROR_TYPE_INFO, " already queued\n");
2222 msg.header.size = htons (sizeof (msg));
2223 msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_KX_PONG);
2224 msg.iv = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX);
2225 msg.nonce = challenge;
2226 LOG (GNUNET_ERROR_TYPE_DEBUG, " sending %u\n", msg.nonce);
2227 t_encrypt (t, &msg.nonce, &msg.nonce,
2228 sizeof (msg.nonce), msg.iv, GNUNET_YES);
2229 LOG (GNUNET_ERROR_TYPE_DEBUG, " e sending %u\n", msg.nonce);
2231 t->pong_h = send_kx (t, &msg.header);
2236 * Initiate a rekey with the remote peer.
2238 * @param cls Closure (tunnel).
2239 * @param tc TaskContext.
2242 rekey_tunnel (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
2244 struct CadetTunnel *t = cls;
2246 t->rekey_task = NULL;
2248 LOG (GNUNET_ERROR_TYPE_INFO, "Re-key Tunnel %s\n", GCT_2s (t));
2249 if (NULL != tc && 0 != (GNUNET_SCHEDULER_REASON_SHUTDOWN & tc->reason))
2252 GNUNET_assert (NULL != t->kx_ctx);
2253 struct GNUNET_TIME_Relative duration;
2255 duration = GNUNET_TIME_absolute_get_duration (t->kx_ctx->rekey_start_time);
2256 LOG (GNUNET_ERROR_TYPE_DEBUG, " kx started %s ago\n",
2257 GNUNET_STRINGS_relative_time_to_string (duration, GNUNET_YES));
2259 // FIXME make duration of old keys configurable
2260 if (duration.rel_value_us >= GNUNET_TIME_UNIT_MINUTES.rel_value_us)
2262 LOG (GNUNET_ERROR_TYPE_DEBUG, " deleting old keys\n");
2263 memset (&t->kx_ctx->d_key_old, 0, sizeof (t->kx_ctx->d_key_old));
2264 memset (&t->kx_ctx->e_key_old, 0, sizeof (t->kx_ctx->e_key_old));
2271 case CADET_TUNNEL_KEY_UNINITIALIZED:
2272 GCT_change_estate (t, CADET_TUNNEL_KEY_SENT);
2275 case CADET_TUNNEL_KEY_SENT:
2278 case CADET_TUNNEL_KEY_OK:
2280 * - state should have changed during rekey_iterator
2281 * - task should have been canceled at pong_handle
2284 GCT_change_estate (t, CADET_TUNNEL_KEY_REKEY);
2287 case CADET_TUNNEL_KEY_PING:
2288 case CADET_TUNNEL_KEY_REKEY:
2292 LOG (GNUNET_ERROR_TYPE_DEBUG, "Unexpected state %u\n", t->estate);
2295 // FIXME exponential backoff
2296 struct GNUNET_TIME_Relative delay;
2298 delay = GNUNET_TIME_relative_divide (rekey_period, 16);
2299 delay = GNUNET_TIME_relative_min (delay, REKEY_WAIT);
2300 LOG (GNUNET_ERROR_TYPE_DEBUG, " next call in %s\n",
2301 GNUNET_STRINGS_relative_time_to_string (delay, GNUNET_YES));
2302 t->rekey_task = GNUNET_SCHEDULER_add_delayed (delay, &rekey_tunnel, t);
2307 * Our ephemeral key has changed, create new session key on all tunnels.
2309 * Each tunnel will start the Key Exchange with a random delay between
2310 * 0 and number_of_tunnels*100 milliseconds, so there are 10 key exchanges
2311 * per second, on average.
2313 * @param cls Closure (size of the hashmap).
2314 * @param key Current public key.
2315 * @param value Value in the hash map (tunnel).
2317 * @return #GNUNET_YES, so we should continue to iterate,
2320 rekey_iterator (void *cls,
2321 const struct GNUNET_PeerIdentity *key,
2324 struct CadetTunnel *t = value;
2325 struct GNUNET_TIME_Relative delay;
2326 long n = (long) cls;
2329 if (NULL != t->rekey_task)
2332 if (GNUNET_YES == GCT_is_loopback (t))
2335 if (CADET_OTR != t->enc_type)
2338 r = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK, (uint32_t) n * 100);
2339 delay = GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MILLISECONDS, r);
2340 t->rekey_task = GNUNET_SCHEDULER_add_delayed (delay, &rekey_tunnel, t);
2341 if (GNUNET_OK == create_kx_ctx (t))
2342 GCT_change_estate (t, CADET_TUNNEL_KEY_REKEY);
2354 * Create a new ephemeral key and key message, schedule next rekeying.
2356 * @param cls Closure (unused).
2357 * @param tc TaskContext.
2360 global_otr_rekey (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
2362 struct GNUNET_TIME_Absolute time;
2367 if (0 != (GNUNET_SCHEDULER_REASON_SHUTDOWN & tc->reason))
2370 GNUNET_free_non_null (otr_ephemeral_key);
2371 otr_ephemeral_key = GNUNET_CRYPTO_ecdhe_key_create ();
2373 time = GNUNET_TIME_absolute_get ();
2374 otr_kx_msg.creation_time = GNUNET_TIME_absolute_hton (time);
2375 time = GNUNET_TIME_absolute_add (time, rekey_period);
2376 time = GNUNET_TIME_absolute_add (time, GNUNET_TIME_UNIT_MINUTES);
2377 otr_kx_msg.expiration_time = GNUNET_TIME_absolute_hton (time);
2378 GNUNET_CRYPTO_ecdhe_key_get_public (otr_ephemeral_key, &otr_kx_msg.ephemeral_key);
2379 LOG (GNUNET_ERROR_TYPE_INFO, "GLOBAL OTR RE-KEY, NEW EPHM: %s\n",
2380 GNUNET_h2s ((struct GNUNET_HashCode *) &otr_kx_msg.ephemeral_key));
2382 GNUNET_assert (GNUNET_OK ==
2383 GNUNET_CRYPTO_eddsa_sign (id_key,
2384 &otr_kx_msg.purpose,
2385 &otr_kx_msg.signature));
2387 n = (long) GNUNET_CONTAINER_multipeermap_size (tunnels);
2388 GNUNET_CONTAINER_multipeermap_iterate (tunnels, &rekey_iterator, (void *) n);
2390 rekey_task = GNUNET_SCHEDULER_add_delayed (rekey_period,
2391 &global_otr_rekey, NULL);
2396 * Called only on shutdown, destroy every tunnel.
2398 * @param cls Closure (unused).
2399 * @param key Current public key.
2400 * @param value Value in the hash map (tunnel).
2402 * @return #GNUNET_YES, so we should continue to iterate,
2405 destroy_iterator (void *cls,
2406 const struct GNUNET_PeerIdentity *key,
2409 struct CadetTunnel *t = value;
2411 LOG (GNUNET_ERROR_TYPE_DEBUG, "GCT_shutdown destroying tunnel at %p\n", t);
2418 * Notify remote peer that we don't know a channel he is talking about,
2419 * probably CHANNEL_DESTROY was missed.
2421 * @param t Tunnel on which to notify.
2422 * @param gid ID of the channel.
2425 send_channel_destroy (struct CadetTunnel *t, unsigned int gid)
2427 struct GNUNET_CADET_ChannelManage msg;
2429 msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_CHANNEL_DESTROY);
2430 msg.header.size = htons (sizeof (msg));
2431 msg.chid = htonl (gid);
2433 LOG (GNUNET_ERROR_TYPE_DEBUG,
2434 "WARNING destroying unknown channel %u on tunnel %s\n",
2436 send_prebuilt_message (&msg.header, t, NULL, GNUNET_YES, NULL, NULL, NULL);
2441 * Demultiplex data per channel and call appropriate channel handler.
2443 * @param t Tunnel on which the data came.
2444 * @param msg Data message.
2445 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
2446 * #GNUNET_YES if message is FWD on the respective channel (loopback)
2447 * #GNUNET_NO if message is BCK on the respective channel (loopback)
2448 * #GNUNET_SYSERR if message on a one-ended channel (remote)
2451 handle_data (struct CadetTunnel *t,
2452 const struct GNUNET_CADET_Data *msg,
2455 struct CadetChannel *ch;
2459 size = ntohs (msg->header.size);
2461 sizeof (struct GNUNET_CADET_Data) +
2462 sizeof (struct GNUNET_MessageHeader))
2467 LOG (GNUNET_ERROR_TYPE_DEBUG, " payload of type %s\n",
2468 GC_m2s (ntohs (msg[1].header.type)));
2471 ch = GCT_get_channel (t, ntohl (msg->chid));
2474 GNUNET_STATISTICS_update (stats, "# data on unknown channel",
2476 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel 0x%X unknown\n",
2478 send_channel_destroy (t, ntohl (msg->chid));
2482 GCCH_handle_data (ch, msg, fwd);
2487 * Demultiplex data ACKs per channel and update appropriate channel buffer info.
2489 * @param t Tunnel on which the DATA ACK came.
2490 * @param msg DATA ACK message.
2491 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
2492 * #GNUNET_YES if message is FWD on the respective channel (loopback)
2493 * #GNUNET_NO if message is BCK on the respective channel (loopback)
2494 * #GNUNET_SYSERR if message on a one-ended channel (remote)
2497 handle_data_ack (struct CadetTunnel *t,
2498 const struct GNUNET_CADET_DataACK *msg,
2501 struct CadetChannel *ch;
2505 size = ntohs (msg->header.size);
2506 if (size != sizeof (struct GNUNET_CADET_DataACK))
2513 ch = GCT_get_channel (t, ntohl (msg->chid));
2516 GNUNET_STATISTICS_update (stats, "# data ack on unknown channel",
2518 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel %u unknown\n",
2523 GCCH_handle_data_ack (ch, msg, fwd);
2528 * Handle channel create.
2530 * @param t Tunnel on which the data came.
2531 * @param msg Data message.
2534 handle_ch_create (struct CadetTunnel *t,
2535 const struct GNUNET_CADET_ChannelCreate *msg)
2537 struct CadetChannel *ch;
2541 size = ntohs (msg->header.size);
2542 if (size != sizeof (struct GNUNET_CADET_ChannelCreate))
2549 ch = GCT_get_channel (t, ntohl (msg->chid));
2550 if (NULL != ch && ! GCT_is_loopback (t))
2552 /* Probably a retransmission, safe to ignore */
2553 LOG (GNUNET_ERROR_TYPE_DEBUG, " already exists...\n");
2555 ch = GCCH_handle_create (t, msg);
2557 GCT_add_channel (t, ch);
2563 * Handle channel NACK: check correctness and call channel handler for NACKs.
2565 * @param t Tunnel on which the NACK came.
2566 * @param msg NACK message.
2569 handle_ch_nack (struct CadetTunnel *t,
2570 const struct GNUNET_CADET_ChannelManage *msg)
2572 struct CadetChannel *ch;
2576 size = ntohs (msg->header.size);
2577 if (size != sizeof (struct GNUNET_CADET_ChannelManage))
2584 ch = GCT_get_channel (t, ntohl (msg->chid));
2587 GNUNET_STATISTICS_update (stats, "# channel NACK on unknown channel",
2589 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel %u unknown\n",
2594 GCCH_handle_nack (ch);
2599 * Handle a CHANNEL ACK (SYNACK/ACK).
2601 * @param t Tunnel on which the CHANNEL ACK came.
2602 * @param msg CHANNEL ACK message.
2603 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
2604 * #GNUNET_YES if message is FWD on the respective channel (loopback)
2605 * #GNUNET_NO if message is BCK on the respective channel (loopback)
2606 * #GNUNET_SYSERR if message on a one-ended channel (remote)
2609 handle_ch_ack (struct CadetTunnel *t,
2610 const struct GNUNET_CADET_ChannelManage *msg,
2613 struct CadetChannel *ch;
2617 size = ntohs (msg->header.size);
2618 if (size != sizeof (struct GNUNET_CADET_ChannelManage))
2625 ch = GCT_get_channel (t, ntohl (msg->chid));
2628 GNUNET_STATISTICS_update (stats, "# channel ack on unknown channel",
2630 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel %u unknown\n",
2635 GCCH_handle_ack (ch, msg, fwd);
2640 * Handle a channel destruction message.
2642 * @param t Tunnel on which the message came.
2643 * @param msg Channel destroy message.
2644 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
2645 * #GNUNET_YES if message is FWD on the respective channel (loopback)
2646 * #GNUNET_NO if message is BCK on the respective channel (loopback)
2647 * #GNUNET_SYSERR if message on a one-ended channel (remote)
2650 handle_ch_destroy (struct CadetTunnel *t,
2651 const struct GNUNET_CADET_ChannelManage *msg,
2654 struct CadetChannel *ch;
2658 size = ntohs (msg->header.size);
2659 if (size != sizeof (struct GNUNET_CADET_ChannelManage))
2666 ch = GCT_get_channel (t, ntohl (msg->chid));
2669 /* Probably a retransmission, safe to ignore */
2673 GCCH_handle_destroy (ch, msg, fwd);
2678 * Create a new Axolotl ephemeral (ratchet) key.
2683 new_ephemeral (struct CadetTunnel *t)
2685 GNUNET_free_non_null (t->ax->DHRs);
2686 t->ax->DHRs = GNUNET_CRYPTO_ecdhe_key_create();
2691 * Free Axolotl data.
2696 destroy_ax (struct CadetTunnel *t)
2701 GNUNET_free_non_null (t->ax->DHRs);
2702 GNUNET_free_non_null (t->ax->kx_0);
2704 GNUNET_free (t->ax);
2707 if (NULL != t->rekey_task)
2709 GNUNET_SCHEDULER_cancel (t->rekey_task);
2710 t->rekey_task = NULL;
2712 if (NULL != t->ephm_h)
2714 GCC_cancel (t->ephm_h);
2722 * The peer's ephemeral key has changed: update the symmetrical keys.
2724 * @param t Tunnel this message came on.
2725 * @param msg Key eXchange message.
2728 handle_ephemeral (struct CadetTunnel *t,
2729 const struct GNUNET_CADET_KX_Ephemeral *msg)
2731 LOG (GNUNET_ERROR_TYPE_INFO, "<=== EPHM for %s\n", GCT_2s (t));
2733 if (GNUNET_OK != check_ephemeral (t, msg))
2735 GNUNET_break_op (0);
2739 /* If we get a proper OTR-style ephemeral, fallback to old crypto. */
2743 t->enc_type = CADET_OTR;
2744 if (NULL != t->rekey_task)
2745 GNUNET_SCHEDULER_cancel (t->rekey_task);
2746 if (GNUNET_OK != create_kx_ctx (t))
2752 rekey_tunnel (t, NULL);
2753 GNUNET_STATISTICS_update (stats, "# otr-downgrades", -1, GNUNET_NO);
2757 * If the key is different from what we know, derive the new E/D keys.
2758 * Else destroy the rekey ctx (duplicate EPHM after successful KX).
2760 if (0 != memcmp (&t->peers_ephemeral_key, &msg->ephemeral_key,
2761 sizeof (msg->ephemeral_key)))
2763 #if DUMP_KEYS_TO_STDERR
2764 LOG (GNUNET_ERROR_TYPE_INFO, "OLD: %s\n",
2765 GNUNET_h2s ((struct GNUNET_HashCode *) &t->peers_ephemeral_key));
2766 LOG (GNUNET_ERROR_TYPE_INFO, "NEW: %s\n",
2767 GNUNET_h2s ((struct GNUNET_HashCode *) &msg->ephemeral_key));
2769 t->peers_ephemeral_key = msg->ephemeral_key;
2771 if (GNUNET_OK != create_kx_ctx (t))
2778 if (CADET_TUNNEL_KEY_OK == t->estate)
2780 GCT_change_estate (t, CADET_TUNNEL_KEY_REKEY);
2782 if (NULL != t->rekey_task)
2783 GNUNET_SCHEDULER_cancel (t->rekey_task);
2784 t->rekey_task = GNUNET_SCHEDULER_add_now (rekey_tunnel, t);
2786 if (CADET_TUNNEL_KEY_SENT == t->estate)
2788 LOG (GNUNET_ERROR_TYPE_DEBUG, " our key was sent, sending challenge\n");
2790 GCT_change_estate (t, CADET_TUNNEL_KEY_PING);
2793 if (CADET_TUNNEL_KEY_UNINITIALIZED != ntohl(msg->sender_status))
2797 LOG (GNUNET_ERROR_TYPE_DEBUG, " recv nonce e %u\n", msg->nonce);
2798 t_decrypt (t, &nonce, &msg->nonce, ping_encryption_size (), msg->iv);
2799 LOG (GNUNET_ERROR_TYPE_DEBUG, " recv nonce c %u\n", nonce);
2800 send_pong (t, nonce);
2806 * Peer has answer to our challenge.
2807 * If answer is successful, consider the key exchange finished and clean
2808 * up all related state.
2810 * @param t Tunnel this message came on.
2811 * @param msg Key eXchange Pong message.
2814 handle_pong (struct CadetTunnel *t, const struct GNUNET_CADET_KX_Pong *msg)
2818 LOG (GNUNET_ERROR_TYPE_INFO, "<=== PONG for %s\n", GCT_2s (t));
2819 if (NULL == t->rekey_task)
2821 GNUNET_STATISTICS_update (stats, "# duplicate PONG messages", 1, GNUNET_NO);
2824 if (NULL == t->kx_ctx)
2826 GNUNET_STATISTICS_update (stats, "# stray PONG messages", 1, GNUNET_NO);
2830 t_decrypt (t, &challenge, &msg->nonce, sizeof (uint32_t), msg->iv);
2831 if (challenge != t->kx_ctx->challenge)
2833 LOG (GNUNET_ERROR_TYPE_WARNING, "Wrong PONG challenge on %s\n", GCT_2s (t));
2834 LOG (GNUNET_ERROR_TYPE_DEBUG, "PONG: %u (e: %u). Expected: %u.\n",
2835 challenge, msg->nonce, t->kx_ctx->challenge);
2839 GNUNET_SCHEDULER_cancel (t->rekey_task);
2840 t->rekey_task = NULL;
2842 /* Don't free the old keys right away, but after a delay.
2843 * Rationale: the KX could have happened over a very fast connection,
2844 * with payload traffic still signed with the old key stuck in a slower
2846 * Don't keep the keys longer than 1/4 the rekey period, and no longer than
2850 GCT_change_estate (t, CADET_TUNNEL_KEY_OK);
2855 * Handle Axolotl handshake.
2857 * @param t Tunnel this message came on.
2858 * @param msg Key eXchange Pong message.
2861 handle_kx_ax (struct CadetTunnel *t, const struct GNUNET_CADET_AX_KX *msg)
2863 struct CadetTunnelAxolotl *ax;
2864 struct GNUNET_HashCode key_material[3];
2865 struct GNUNET_CRYPTO_SymmetricSessionKey keys[5];
2866 const struct GNUNET_CRYPTO_EcdhePublicKey *pub;
2867 const struct GNUNET_CRYPTO_EcdhePrivateKey *priv;
2868 const char salt[] = "CADET Axolotl salt";
2869 const struct GNUNET_PeerIdentity *pid;
2872 LOG (GNUNET_ERROR_TYPE_INFO, "<=== AX_KX on %s\n", GCT_2s (t));
2876 /* Something is wrong if ax is NULL. Whose fault it is? */
2877 GNUNET_break_op (CADET_OTR == t->enc_type);
2878 GNUNET_break (CADET_Axolotl == t->enc_type);
2882 if (GNUNET_OK != GCP_check_key (t->peer, &msg->permanent_key,
2883 &msg->purpose, &msg->signature))
2885 GNUNET_break_op (0);
2889 pid = GCT_get_destination (t);
2890 if (0 > GNUNET_CRYPTO_cmp_peer_identity (&my_full_id, pid))
2891 am_I_alice = GNUNET_YES;
2892 else if (0 < GNUNET_CRYPTO_cmp_peer_identity (&my_full_id, pid))
2893 am_I_alice = GNUNET_NO;
2896 GNUNET_break_op (0);
2900 if (GNUNET_YES == ntohl (msg->force_reply))
2901 GCT_send_ax_kx (t, GNUNET_NO);
2903 if (CADET_TUNNEL_KEY_OK == t->estate)
2906 LOG (GNUNET_ERROR_TYPE_INFO, " is Alice? %s\n", am_I_alice ? "YES" : "NO");
2909 ax->DHRr = msg->ratchet_key;
2910 ax->DHIr = msg->permanent_key;
2913 if (GNUNET_YES == am_I_alice)
2915 priv = ax_key; /* A */
2916 pub = &msg->ephemeral_key; /* B0 */
2920 priv = ax->kx_0; /* B0 */
2921 pub = &ax->DHIr; /* A */
2923 GNUNET_CRYPTO_ecc_ecdh (priv, pub, &key_material[0]);
2926 if (GNUNET_YES == am_I_alice)
2928 priv = ax->kx_0; /* A0 */
2929 pub = &ax->DHIr; /* B */
2933 priv = ax_key; /* B */
2934 pub = &msg->ephemeral_key; /* A0 */
2936 GNUNET_CRYPTO_ecc_ecdh (priv, pub, &key_material[1]);
2939 priv = ax->kx_0; /* A0 or B0 */
2940 pub = &msg->ephemeral_key; /* B0 or A0 */
2941 GNUNET_CRYPTO_ecc_ecdh (priv, pub, &key_material[2]);
2943 #if DUMP_KEYS_TO_STDERR
2946 for (i = 0; i < 3; i++)
2947 LOG (GNUNET_ERROR_TYPE_INFO, "km[%u]: %s\n",
2948 i, GNUNET_h2s (&key_material[i]));
2953 GNUNET_CRYPTO_kdf (keys, sizeof (keys),
2954 salt, sizeof (salt),
2955 &key_material, sizeof (key_material), NULL);
2958 if (GNUNET_YES == am_I_alice)
2964 ax->ratchet_flag = GNUNET_YES;
2972 ax->ratchet_flag = GNUNET_NO;
2973 ax->ratchet_allowed = GNUNET_NO;
2974 ax->ratchet_counter = 0;
2975 ax->ratchet_expiration =
2976 GNUNET_TIME_absolute_add (GNUNET_TIME_absolute_get(), ratchet_time);
2978 GCT_change_estate (t, CADET_TUNNEL_KEY_OK);
2983 * Demultiplex by message type and call appropriate handler for a message
2984 * towards a channel of a local tunnel.
2986 * @param t Tunnel this message came on.
2987 * @param msgh Message header.
2988 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
2989 * #GNUNET_YES if message is FWD on the respective channel (loopback)
2990 * #GNUNET_NO if message is BCK on the respective channel (loopback)
2991 * #GNUNET_SYSERR if message on a one-ended channel (remote)
2994 handle_decrypted (struct CadetTunnel *t,
2995 const struct GNUNET_MessageHeader *msgh,
3000 type = ntohs (msgh->type);
3001 LOG (GNUNET_ERROR_TYPE_INFO, "<=== %s on %s\n", GC_m2s (type), GCT_2s (t));
3005 case GNUNET_MESSAGE_TYPE_CADET_KEEPALIVE:
3006 /* Do nothing, connection aleady got updated. */
3007 GNUNET_STATISTICS_update (stats, "# keepalives received", 1, GNUNET_NO);
3010 case GNUNET_MESSAGE_TYPE_CADET_DATA:
3011 /* Don't send hop ACK, wait for client to ACK */
3012 handle_data (t, (struct GNUNET_CADET_Data *) msgh, fwd);
3015 case GNUNET_MESSAGE_TYPE_CADET_DATA_ACK:
3016 handle_data_ack (t, (struct GNUNET_CADET_DataACK *) msgh, fwd);
3019 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_CREATE:
3020 handle_ch_create (t, (struct GNUNET_CADET_ChannelCreate *) msgh);
3023 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_NACK:
3024 handle_ch_nack (t, (struct GNUNET_CADET_ChannelManage *) msgh);
3027 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_ACK:
3028 handle_ch_ack (t, (struct GNUNET_CADET_ChannelManage *) msgh, fwd);
3031 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_DESTROY:
3032 handle_ch_destroy (t, (struct GNUNET_CADET_ChannelManage *) msgh, fwd);
3036 GNUNET_break_op (0);
3037 LOG (GNUNET_ERROR_TYPE_WARNING,
3038 "end-to-end message not known (%u)\n",
3039 ntohs (msgh->type));
3040 GCT_debug (t, GNUNET_ERROR_TYPE_WARNING);
3044 /******************************************************************************/
3045 /******************************** API ***********************************/
3046 /******************************************************************************/
3048 * Decrypt old format and demultiplex by message type. Call appropriate handler
3049 * for a message towards a channel of a local tunnel.
3051 * @param t Tunnel this message came on.
3052 * @param msg Message header.
3055 GCT_handle_encrypted (struct CadetTunnel *t,
3056 const struct GNUNET_MessageHeader *msg)
3058 uint16_t size = ntohs (msg->size);
3060 size_t payload_size;
3063 struct GNUNET_MessageHeader *msgh;
3066 type = ntohs (msg->type);
3067 if (GNUNET_MESSAGE_TYPE_CADET_ENCRYPTED == type)
3069 const struct GNUNET_CADET_Encrypted *emsg;
3071 emsg = (struct GNUNET_CADET_Encrypted *) msg;
3072 payload_size = size - sizeof (struct GNUNET_CADET_Encrypted);
3073 decrypted_size = t_decrypt_and_validate (t, cbuf, &emsg[1], payload_size,
3074 emsg->iv, &emsg->hmac);
3076 else if (GNUNET_MESSAGE_TYPE_CADET_AX == type)
3078 const struct GNUNET_CADET_AX *emsg;
3080 emsg = (struct GNUNET_CADET_AX *) msg;
3081 decrypted_size = t_ax_decrypt_and_validate (t, cbuf, emsg, size);
3084 if (-1 == decrypted_size)
3086 GNUNET_break_op (0);
3091 while (off < decrypted_size)
3095 msgh = (struct GNUNET_MessageHeader *) &cbuf[off];
3096 msize = ntohs (msgh->size);
3097 if (msize < sizeof (struct GNUNET_MessageHeader))
3099 GNUNET_break_op (0);
3102 handle_decrypted (t, msgh, GNUNET_SYSERR);
3109 * Demultiplex an encapsulated KX message by message type.
3111 * @param t Tunnel on which the message came.
3112 * @param message Payload of KX message.
3115 GCT_handle_kx (struct CadetTunnel *t,
3116 const struct GNUNET_MessageHeader *message)
3120 type = ntohs (message->type);
3121 LOG (GNUNET_ERROR_TYPE_DEBUG, "kx message received: %s\n", GC_m2s (type));
3124 case GNUNET_MESSAGE_TYPE_CADET_KX_EPHEMERAL:
3125 handle_ephemeral (t, (const struct GNUNET_CADET_KX_Ephemeral *) message);
3128 case GNUNET_MESSAGE_TYPE_CADET_KX_PONG:
3129 handle_pong (t, (const struct GNUNET_CADET_KX_Pong *) message);
3132 case GNUNET_MESSAGE_TYPE_CADET_AX_KX:
3133 handle_kx_ax (t, (const struct GNUNET_CADET_AX_KX *) message);
3137 GNUNET_break_op (0);
3138 LOG (GNUNET_ERROR_TYPE_WARNING, "kx message %s unknown\n", GC_m2s (type));
3143 * Initialize the tunnel subsystem.
3145 * @param c Configuration handle.
3146 * @param key ECC private key, to derive all other keys and do crypto.
3149 GCT_init (const struct GNUNET_CONFIGURATION_Handle *c,
3150 const struct GNUNET_CRYPTO_EddsaPrivateKey *key)
3152 int expected_overhead;
3154 LOG (GNUNET_ERROR_TYPE_DEBUG, "init\n");
3156 expected_overhead = 0;
3157 expected_overhead += sizeof (struct GNUNET_CADET_Encrypted);
3158 expected_overhead += sizeof (struct GNUNET_CADET_Data);
3159 expected_overhead += sizeof (struct GNUNET_CADET_ACK);
3160 GNUNET_assert (GNUNET_CONSTANTS_CADET_P2P_OVERHEAD == expected_overhead);
3163 GNUNET_CONFIGURATION_get_value_number (c, "CADET", "DEFAULT_TTL",
3166 GNUNET_log_config_invalid (GNUNET_ERROR_TYPE_DEBUG,
3167 "CADET", "DEFAULT_TTL", "USING DEFAULT");
3171 GNUNET_CONFIGURATION_get_value_time (c, "CADET", "REKEY_PERIOD",
3174 rekey_period = GNUNET_TIME_UNIT_DAYS;
3177 GNUNET_CONFIGURATION_get_value_number (c, "CADET", "RATCHET_MESSAGES",
3180 GNUNET_log_config_invalid (GNUNET_ERROR_TYPE_WARNING,
3181 "CADET", "RATCHET_MESSAGES", "USING DEFAULT");
3182 ratchet_messages = 64;
3185 GNUNET_CONFIGURATION_get_value_time (c, "CADET", "RATCHET_TIME",
3188 GNUNET_log_config_invalid (GNUNET_ERROR_TYPE_WARNING,
3189 "CADET", "RATCHET_TIME", "USING DEFAULT");
3190 ratchet_time = GNUNET_TIME_UNIT_HOURS;
3196 otr_kx_msg.header.size = htons (sizeof (otr_kx_msg));
3197 otr_kx_msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_KX_EPHEMERAL);
3198 otr_kx_msg.purpose.purpose = htonl (GNUNET_SIGNATURE_PURPOSE_CADET_KX);
3199 otr_kx_msg.purpose.size = htonl (ephemeral_purpose_size ());
3200 otr_kx_msg.origin_identity = my_full_id;
3201 rekey_task = GNUNET_SCHEDULER_add_now (&global_otr_rekey, NULL);
3203 ax_key = GNUNET_CRYPTO_ecdhe_key_create ();
3204 GNUNET_CRYPTO_ecdhe_key_get_public (ax_key, &ax_identity.permanent_key);
3205 ax_identity.purpose.purpose = htonl (GNUNET_SIGNATURE_PURPOSE_CADET_AXKX);
3206 ax_identity.purpose.size = htonl (ax_purpose_size ());
3207 GNUNET_assert (GNUNET_OK ==
3208 GNUNET_CRYPTO_eddsa_sign (id_key,
3209 &ax_identity.purpose,
3210 &ax_identity.signature));
3212 tunnels = GNUNET_CONTAINER_multipeermap_create (128, GNUNET_YES);
3217 * Shut down the tunnel subsystem.
3222 if (NULL != rekey_task)
3224 GNUNET_SCHEDULER_cancel (rekey_task);
3227 GNUNET_CONTAINER_multipeermap_iterate (tunnels, &destroy_iterator, NULL);
3228 GNUNET_CONTAINER_multipeermap_destroy (tunnels);
3229 GNUNET_free (ax_key);
3236 * @param destination Peer this tunnel is towards.
3238 struct CadetTunnel *
3239 GCT_new (struct CadetPeer *destination)
3241 struct CadetTunnel *t;
3243 t = GNUNET_new (struct CadetTunnel);
3245 t->peer = destination;
3248 GNUNET_CONTAINER_multipeermap_put (tunnels, GCP_get_id (destination), t,
3249 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_FAST))
3255 t->ax = GNUNET_new (struct CadetTunnelAxolotl);
3257 t->ax->kx_0 = GNUNET_CRYPTO_ecdhe_key_create ();
3263 * Change the tunnel's connection state.
3265 * @param t Tunnel whose connection state to change.
3266 * @param cstate New connection state.
3269 GCT_change_cstate (struct CadetTunnel* t, enum CadetTunnelCState cstate)
3273 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel %s cstate %s => %s\n",
3274 GCP_2s (t->peer), cstate2s (t->cstate), cstate2s (cstate));
3275 if (myid != GCP_get_short_id (t->peer) &&
3276 CADET_TUNNEL_READY != t->cstate &&
3277 CADET_TUNNEL_READY == cstate)
3280 if (CADET_TUNNEL_KEY_OK == t->estate)
3282 LOG (GNUNET_ERROR_TYPE_DEBUG, " cstate triggered send queued data\n");
3283 send_queued_data (t);
3285 else if (CADET_TUNNEL_KEY_UNINITIALIZED == t->estate)
3287 LOG (GNUNET_ERROR_TYPE_DEBUG, " cstate triggered kx\n");
3288 GCT_send_ax_kx (t, GNUNET_NO);
3292 LOG (GNUNET_ERROR_TYPE_DEBUG, "estate %s\n", estate2s (t->estate));
3297 if (CADET_TUNNEL_READY == cstate
3298 && CONNECTIONS_PER_TUNNEL <= GCT_count_connections (t))
3300 LOG (GNUNET_ERROR_TYPE_DEBUG, " cstate triggered stop dht\n");
3301 GCP_stop_search (t->peer);
3307 * Change the tunnel encryption state.
3309 * @param t Tunnel whose encryption state to change, or NULL.
3310 * @param state New encryption state.
3313 GCT_change_estate (struct CadetTunnel* t, enum CadetTunnelEState state)
3315 enum CadetTunnelEState old;
3322 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel %s estate was %s\n",
3323 GCP_2s (t->peer), estate2s (old));
3324 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel %s estate is now %s\n",
3325 GCP_2s (t->peer), estate2s (t->estate));
3327 /* Send queued data if enc state changes to OK */
3328 if (myid != GCP_get_short_id (t->peer) &&
3329 CADET_TUNNEL_KEY_OK != old && CADET_TUNNEL_KEY_OK == t->estate)
3331 send_queued_data (t);
3337 * @brief Check if tunnel has too many connections, and remove one if necessary.
3339 * Currently this means the newest connection, unless it is a direct one.
3340 * Implemented as a task to avoid freeing a connection that is in the middle
3341 * of being created/processed.
3343 * @param cls Closure (Tunnel to check).
3344 * @param tc Task context.
3347 trim_connections (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
3349 struct CadetTunnel *t = cls;
3351 t->trim_connections_task = NULL;
3353 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
3356 if (GCT_count_connections (t) > 2 * CONNECTIONS_PER_TUNNEL)
3358 struct CadetTConnection *iter;
3359 struct CadetTConnection *c;
3361 for (c = iter = t->connection_head; NULL != iter; iter = iter->next)
3363 if ((iter->created.abs_value_us > c->created.abs_value_us)
3364 && GNUNET_NO == GCC_is_direct (iter->c))
3371 LOG (GNUNET_ERROR_TYPE_DEBUG, "Too many connections on tunnel %s\n",
3373 LOG (GNUNET_ERROR_TYPE_DEBUG, "Destroying connection %s\n",
3386 * Add a connection to a tunnel.
3389 * @param c Connection.
3392 GCT_add_connection (struct CadetTunnel *t, struct CadetConnection *c)
3394 struct CadetTConnection *aux;
3396 GNUNET_assert (NULL != c);
3398 LOG (GNUNET_ERROR_TYPE_DEBUG, "add connection %s\n", GCC_2s (c));
3399 LOG (GNUNET_ERROR_TYPE_DEBUG, " to tunnel %s\n", GCT_2s (t));
3400 for (aux = t->connection_head; aux != NULL; aux = aux->next)
3404 aux = GNUNET_new (struct CadetTConnection);
3406 aux->created = GNUNET_TIME_absolute_get ();
3408 GNUNET_CONTAINER_DLL_insert (t->connection_head, t->connection_tail, aux);
3410 if (CADET_TUNNEL_SEARCHING == t->cstate)
3411 GCT_change_cstate (t, CADET_TUNNEL_WAITING);
3413 if (NULL != t->trim_connections_task)
3414 t->trim_connections_task = GNUNET_SCHEDULER_add_now (&trim_connections, t);
3419 * Remove a connection from a tunnel.
3422 * @param c Connection.
3425 GCT_remove_connection (struct CadetTunnel *t,
3426 struct CadetConnection *c)
3428 struct CadetTConnection *aux;
3429 struct CadetTConnection *next;
3432 LOG (GNUNET_ERROR_TYPE_DEBUG, "Removing connection %s from tunnel %s\n",
3433 GCC_2s (c), GCT_2s (t));
3434 for (aux = t->connection_head; aux != NULL; aux = next)
3439 GNUNET_CONTAINER_DLL_remove (t->connection_head, t->connection_tail, aux);
3444 conns = GCT_count_connections (t);
3446 && NULL == t->destroy_task
3447 && CADET_TUNNEL_SHUTDOWN != t->cstate
3448 && GNUNET_NO == shutting_down)
3450 if (0 == GCT_count_any_connections (t))
3451 GCT_change_cstate (t, CADET_TUNNEL_SEARCHING);
3453 GCT_change_cstate (t, CADET_TUNNEL_WAITING);
3456 /* Start new connections if needed */
3457 if (CONNECTIONS_PER_TUNNEL > conns
3458 && NULL == t->destroy_task
3459 && CADET_TUNNEL_SHUTDOWN != t->cstate
3460 && GNUNET_NO == shutting_down)
3462 LOG (GNUNET_ERROR_TYPE_DEBUG, " too few connections, getting new ones\n");
3463 GCP_connect (t->peer); /* Will change cstate to WAITING when possible */
3467 /* If not marked as ready, no change is needed */
3468 if (CADET_TUNNEL_READY != t->cstate)
3471 /* Check if any connection is ready to maintain cstate */
3472 for (aux = t->connection_head; aux != NULL; aux = aux->next)
3473 if (CADET_CONNECTION_READY == GCC_get_state (aux->c))
3479 * Add a channel to a tunnel.
3482 * @param ch Channel.
3485 GCT_add_channel (struct CadetTunnel *t, struct CadetChannel *ch)
3487 struct CadetTChannel *aux;
3489 GNUNET_assert (NULL != ch);
3491 LOG (GNUNET_ERROR_TYPE_DEBUG, "Adding channel %p to tunnel %p\n", ch, t);
3493 for (aux = t->channel_head; aux != NULL; aux = aux->next)
3495 LOG (GNUNET_ERROR_TYPE_DEBUG, " already there %p\n", aux->ch);
3500 aux = GNUNET_new (struct CadetTChannel);
3502 LOG (GNUNET_ERROR_TYPE_DEBUG, " adding %p to %p\n", aux, t->channel_head);
3503 GNUNET_CONTAINER_DLL_insert_tail (t->channel_head, t->channel_tail, aux);
3505 if (NULL != t->destroy_task)
3507 GNUNET_SCHEDULER_cancel (t->destroy_task);
3508 t->destroy_task = NULL;
3509 LOG (GNUNET_ERROR_TYPE_DEBUG, " undo destroy!\n");
3515 * Remove a channel from a tunnel.
3518 * @param ch Channel.
3521 GCT_remove_channel (struct CadetTunnel *t, struct CadetChannel *ch)
3523 struct CadetTChannel *aux;
3525 LOG (GNUNET_ERROR_TYPE_DEBUG, "Removing channel %p from tunnel %p\n", ch, t);
3526 for (aux = t->channel_head; aux != NULL; aux = aux->next)
3530 LOG (GNUNET_ERROR_TYPE_DEBUG, " found! %s\n", GCCH_2s (ch));
3531 GNUNET_CONTAINER_DLL_remove (t->channel_head, t->channel_tail, aux);
3540 * Search for a channel by global ID.
3542 * @param t Tunnel containing the channel.
3543 * @param chid Public channel number.
3545 * @return channel handler, NULL if doesn't exist
3547 struct CadetChannel *
3548 GCT_get_channel (struct CadetTunnel *t, CADET_ChannelNumber chid)
3550 struct CadetTChannel *iter;
3555 for (iter = t->channel_head; NULL != iter; iter = iter->next)
3557 if (GCCH_get_id (iter->ch) == chid)
3561 return NULL == iter ? NULL : iter->ch;
3566 * @brief Destroy a tunnel and free all resources.
3568 * Should only be called a while after the tunnel has been marked as destroyed,
3569 * in case there is a new channel added to the same peer shortly after marking
3570 * the tunnel. This way we avoid a new public key handshake.
3572 * @param cls Closure (tunnel to destroy).
3573 * @param tc Task context.
3576 delayed_destroy (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
3578 struct CadetTunnel *t = cls;
3579 struct CadetTConnection *iter;
3581 LOG (GNUNET_ERROR_TYPE_DEBUG, "delayed destroying tunnel %p\n", t);
3582 if (0 != (GNUNET_SCHEDULER_REASON_SHUTDOWN & tc->reason))
3584 LOG (GNUNET_ERROR_TYPE_WARNING,
3585 "Not destroying tunnel, due to shutdown. "
3586 "Tunnel at %p should have been freed by GCT_shutdown\n", t);
3589 t->destroy_task = NULL;
3590 t->cstate = CADET_TUNNEL_SHUTDOWN;
3592 for (iter = t->connection_head; NULL != iter; iter = iter->next)
3594 GCC_send_destroy (iter->c);
3601 * Tunnel is empty: destroy it.
3603 * Notifies all connections about the destruction.
3605 * @param t Tunnel to destroy.
3608 GCT_destroy_empty (struct CadetTunnel *t)
3610 if (GNUNET_YES == shutting_down)
3611 return; /* Will be destroyed immediately anyway */
3613 if (NULL != t->destroy_task)
3615 LOG (GNUNET_ERROR_TYPE_WARNING,
3616 "Tunnel %s is already scheduled for destruction. Tunnel debug dump:\n",
3618 GCT_debug (t, GNUNET_ERROR_TYPE_WARNING);
3620 /* should never happen, tunnel can only become empty once, and the
3621 * task identifier should be NO_TASK (cleaned when the tunnel was created
3622 * or became un-empty)
3627 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel %s empty: scheduling destruction\n",
3630 // FIXME make delay a config option
3631 t->destroy_task = GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_MINUTES,
3632 &delayed_destroy, t);
3633 LOG (GNUNET_ERROR_TYPE_DEBUG, "Scheduled destroy of %p as %llu\n",
3634 t, t->destroy_task);
3639 * Destroy tunnel if empty (no more channels).
3641 * @param t Tunnel to destroy if empty.
3644 GCT_destroy_if_empty (struct CadetTunnel *t)
3646 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel %s destroy if empty\n", GCT_2s (t));
3647 if (0 < GCT_count_channels (t))
3650 GCT_destroy_empty (t);
3655 * Destroy the tunnel.
3657 * This function does not generate any warning traffic to clients or peers.
3660 * Cancel messages belonging to this tunnel queued to neighbors.
3661 * Free any allocated resources linked to the tunnel.
3663 * @param t The tunnel to destroy.
3666 GCT_destroy (struct CadetTunnel *t)
3668 struct CadetTConnection *iter_c;
3669 struct CadetTConnection *next_c;
3670 struct CadetTChannel *iter_ch;
3671 struct CadetTChannel *next_ch;
3676 LOG (GNUNET_ERROR_TYPE_DEBUG, "destroying tunnel %s\n", GCP_2s (t->peer));
3678 GNUNET_break (GNUNET_YES ==
3679 GNUNET_CONTAINER_multipeermap_remove (tunnels,
3680 GCP_get_id (t->peer), t));
3682 for (iter_c = t->connection_head; NULL != iter_c; iter_c = next_c)
3684 next_c = iter_c->next;
3685 GCC_destroy (iter_c->c);
3687 for (iter_ch = t->channel_head; NULL != iter_ch; iter_ch = next_ch)
3689 next_ch = iter_ch->next;
3690 GCCH_destroy (iter_ch->ch);
3691 /* Should only happen on shutdown, but it's ok. */
3694 if (NULL != t->destroy_task)
3696 LOG (GNUNET_ERROR_TYPE_DEBUG, "cancelling dest: %llX\n", t->destroy_task);
3697 GNUNET_SCHEDULER_cancel (t->destroy_task);
3698 t->destroy_task = NULL;
3701 if (NULL != t->trim_connections_task)
3703 LOG (GNUNET_ERROR_TYPE_DEBUG, "cancelling trim: %llX\n",
3704 t->trim_connections_task);
3705 GNUNET_SCHEDULER_cancel (t->trim_connections_task);
3706 t->trim_connections_task = NULL;
3709 GNUNET_STATISTICS_update (stats, "# tunnels", -1, GNUNET_NO);
3710 GCP_set_tunnel (t->peer, NULL);
3712 if (NULL != t->rekey_task)
3714 GNUNET_SCHEDULER_cancel (t->rekey_task);
3715 t->rekey_task = NULL;
3717 if (NULL != t->kx_ctx)
3719 if (NULL != t->kx_ctx->finish_task)
3720 GNUNET_SCHEDULER_cancel (t->kx_ctx->finish_task);
3721 GNUNET_free (t->kx_ctx);
3732 * @brief Use the given path for the tunnel.
3733 * Update the next and prev hops (and RCs).
3734 * (Re)start the path refresh in case the tunnel is locally owned.
3736 * @param t Tunnel to update.
3737 * @param p Path to use.
3739 * @return Connection created.
3741 struct CadetConnection *
3742 GCT_use_path (struct CadetTunnel *t, struct CadetPeerPath *p)
3744 struct CadetConnection *c;
3745 struct GNUNET_CADET_Hash cid;
3746 unsigned int own_pos;
3748 if (NULL == t || NULL == p)
3754 if (CADET_TUNNEL_SHUTDOWN == t->cstate)
3760 for (own_pos = 0; own_pos < p->length; own_pos++)
3762 if (p->peers[own_pos] == myid)
3765 if (own_pos >= p->length)
3767 GNUNET_break_op (0);
3771 GNUNET_CRYPTO_random_block (GNUNET_CRYPTO_QUALITY_NONCE, &cid, sizeof (cid));
3772 c = GCC_new (&cid, t, p, own_pos);
3775 /* Path was flawed */
3778 GCT_add_connection (t, c);
3784 * Count all created connections of a tunnel. Not necessarily ready connections!
3786 * @param t Tunnel on which to count.
3788 * @return Number of connections created, either being established or ready.
3791 GCT_count_any_connections (struct CadetTunnel *t)
3793 struct CadetTConnection *iter;
3799 for (count = 0, iter = t->connection_head; NULL != iter; iter = iter->next)
3807 * Count established (ready) connections of a tunnel.
3809 * @param t Tunnel on which to count.
3811 * @return Number of connections.
3814 GCT_count_connections (struct CadetTunnel *t)
3816 struct CadetTConnection *iter;
3822 for (count = 0, iter = t->connection_head; NULL != iter; iter = iter->next)
3823 if (CADET_CONNECTION_READY == GCC_get_state (iter->c))
3831 * Count channels of a tunnel.
3833 * @param t Tunnel on which to count.
3835 * @return Number of channels.
3838 GCT_count_channels (struct CadetTunnel *t)
3840 struct CadetTChannel *iter;
3843 for (count = 0, iter = t->channel_head;
3845 iter = iter->next, count++) /* skip */;
3852 * Get the connectivity state of a tunnel.
3856 * @return Tunnel's connectivity state.
3858 enum CadetTunnelCState
3859 GCT_get_cstate (struct CadetTunnel *t)
3864 return (enum CadetTunnelCState) -1;
3871 * Get the encryption state of a tunnel.
3875 * @return Tunnel's encryption state.
3877 enum CadetTunnelEState
3878 GCT_get_estate (struct CadetTunnel *t)
3883 return (enum CadetTunnelEState) -1;
3889 * Get the maximum buffer space for a tunnel towards a local client.
3893 * @return Biggest buffer space offered by any channel in the tunnel.
3896 GCT_get_channels_buffer (struct CadetTunnel *t)
3898 struct CadetTChannel *iter;
3899 unsigned int buffer;
3900 unsigned int ch_buf;
3902 if (NULL == t->channel_head)
3904 /* Probably getting buffer for a channel create/handshake. */
3905 LOG (GNUNET_ERROR_TYPE_DEBUG, " no channels, allow max\n");
3910 for (iter = t->channel_head; NULL != iter; iter = iter->next)
3912 ch_buf = get_channel_buffer (iter);
3913 if (ch_buf > buffer)
3921 * Get the total buffer space for a tunnel for P2P traffic.
3925 * @return Buffer space offered by all connections in the tunnel.
3928 GCT_get_connections_buffer (struct CadetTunnel *t)
3930 struct CadetTConnection *iter;
3931 unsigned int buffer;
3933 if (GNUNET_NO == is_ready (t))
3935 if (count_queued_data (t) > 3)
3942 for (iter = t->connection_head; NULL != iter; iter = iter->next)
3944 if (GCC_get_state (iter->c) != CADET_CONNECTION_READY)
3948 buffer += get_connection_buffer (iter);
3956 * Get the tunnel's destination.
3960 * @return ID of the destination peer.
3962 const struct GNUNET_PeerIdentity *
3963 GCT_get_destination (struct CadetTunnel *t)
3965 return GCP_get_id (t->peer);
3970 * Get the tunnel's next free global channel ID.
3974 * @return GID of a channel free to use.
3977 GCT_get_next_chid (struct CadetTunnel *t)
3979 CADET_ChannelNumber chid;
3980 CADET_ChannelNumber mask;
3983 /* Set bit 30 depending on the ID relationship. Bit 31 is always 0 for GID.
3984 * If our ID is bigger or loopback tunnel, start at 0, bit 30 = 0
3985 * If peer's ID is bigger, start at 0x4... bit 30 = 1
3987 result = GNUNET_CRYPTO_cmp_peer_identity (&my_full_id, GCP_get_id (t->peer));
3992 t->next_chid |= mask;
3994 while (NULL != GCT_get_channel (t, t->next_chid))
3996 LOG (GNUNET_ERROR_TYPE_DEBUG, "Channel %u exists...\n", t->next_chid);
3997 t->next_chid = (t->next_chid + 1) & ~GNUNET_CADET_LOCAL_CHANNEL_ID_CLI;
3998 t->next_chid |= mask;
4000 chid = t->next_chid;
4001 t->next_chid = (t->next_chid + 1) & ~GNUNET_CADET_LOCAL_CHANNEL_ID_CLI;
4002 t->next_chid |= mask;
4009 * Send ACK on one or more channels due to buffer in connections.
4011 * @param t Channel which has some free buffer space.
4014 GCT_unchoke_channels (struct CadetTunnel *t)
4016 struct CadetTChannel *iter;
4017 unsigned int buffer;
4018 unsigned int channels = GCT_count_channels (t);
4019 unsigned int choked_n;
4020 struct CadetChannel *choked[channels];
4022 LOG (GNUNET_ERROR_TYPE_DEBUG, "GCT_unchoke_channels on %s\n", GCT_2s (t));
4023 LOG (GNUNET_ERROR_TYPE_DEBUG, " head: %p\n", t->channel_head);
4024 if (NULL != t->channel_head)
4025 LOG (GNUNET_ERROR_TYPE_DEBUG, " head ch: %p\n", t->channel_head->ch);
4027 /* Get buffer space */
4028 buffer = GCT_get_connections_buffer (t);
4034 /* Count and remember choked channels */
4036 for (iter = t->channel_head; NULL != iter; iter = iter->next)
4038 if (GNUNET_NO == get_channel_allowed (iter))
4040 choked[choked_n++] = iter->ch;
4044 /* Unchoke random channels */
4045 while (0 < buffer && 0 < choked_n)
4047 unsigned int r = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK,
4049 GCCH_allow_client (choked[r], GCCH_is_origin (choked[r], GNUNET_YES));
4052 choked[r] = choked[choked_n];
4058 * Send ACK on one or more connections due to buffer space to the client.
4060 * Iterates all connections of the tunnel and sends ACKs appropriately.
4065 GCT_send_connection_acks (struct CadetTunnel *t)
4067 struct CadetTConnection *iter;
4070 uint32_t allow_per_connection;
4072 unsigned int buffer;
4074 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel send connection ACKs on %s\n",
4083 if (CADET_TUNNEL_READY != t->cstate)
4086 buffer = GCT_get_channels_buffer (t);
4087 LOG (GNUNET_ERROR_TYPE_DEBUG, " buffer %u\n", buffer);
4089 /* Count connections, how many messages are already allowed */
4090 cs = GCT_count_connections (t);
4091 for (allowed = 0, iter = t->connection_head; NULL != iter; iter = iter->next)
4093 allowed += get_connection_allowed (iter);
4095 LOG (GNUNET_ERROR_TYPE_DEBUG, " allowed %u\n", allowed);
4097 /* Make sure there is no overflow */
4098 if (allowed > buffer)
4101 /* Authorize connections to send more data */
4102 to_allow = buffer - allowed;
4104 for (iter = t->connection_head;
4105 NULL != iter && to_allow > 0;
4108 if (CADET_CONNECTION_READY != GCC_get_state (iter->c)
4109 || get_connection_allowed (iter) > 64 / 3)
4113 allow_per_connection = to_allow/cs;
4114 to_allow -= allow_per_connection;
4116 GCC_allow (iter->c, allow_per_connection,
4117 GCC_is_origin (iter->c, GNUNET_NO));
4122 /* Since we don't allow if it's allowed to send 64/3, this can happen. */
4123 LOG (GNUNET_ERROR_TYPE_DEBUG, " reminding to_allow: %u\n", to_allow);
4129 * Cancel a previously sent message while it's in the queue.
4131 * ONLY can be called before the continuation given to the send function
4132 * is called. Once the continuation is called, the message is no longer in the
4135 * @param q Handle to the queue.
4138 GCT_cancel (struct CadetTunnelQueue *q)
4143 /* tun_message_sent() will be called and free q */
4145 else if (NULL != q->tqd)
4147 unqueue_data (q->tqd);
4149 if (NULL != q->cont)
4150 q->cont (q->cont_cls, NULL, q, 0, 0);
4161 * Sends an already built message on a tunnel, encrypting it and
4162 * choosing the best connection if not provided.
4164 * @param message Message to send. Function modifies it.
4165 * @param t Tunnel on which this message is transmitted.
4166 * @param c Connection to use (autoselect if NULL).
4167 * @param force Force the tunnel to take the message (buffer overfill).
4168 * @param cont Continuation to call once message is really sent.
4169 * @param cont_cls Closure for @c cont.
4171 * @return Handle to cancel message. NULL if @c cont is NULL.
4173 struct CadetTunnelQueue *
4174 GCT_send_prebuilt_message (const struct GNUNET_MessageHeader *message,
4175 struct CadetTunnel *t, struct CadetConnection *c,
4176 int force, GCT_sent cont, void *cont_cls)
4178 return send_prebuilt_message (message, t, c, force, cont, cont_cls, NULL);
4183 * Send an Axolotl KX message.
4185 * @param t Tunnel on which to send it.
4186 * @param force_reply Force the other peer to reply with a KX message.
4189 GCT_send_ax_kx (struct CadetTunnel *t, int force_reply)
4191 struct GNUNET_CADET_AX_KX msg;
4193 LOG (GNUNET_ERROR_TYPE_INFO, "===> AX_KX for %s\n", GCT_2s (t));
4194 if (NULL != t->ephm_h)
4196 LOG (GNUNET_ERROR_TYPE_INFO, " already queued\n");
4200 msg.header.size = htons (sizeof (msg));
4201 msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_AX_KX);
4202 msg.force_reply = htonl (force_reply);
4203 msg.permanent_key = ax_identity.permanent_key;
4204 msg.purpose = ax_identity.purpose;
4205 msg.signature = ax_identity.signature;
4206 GNUNET_CRYPTO_ecdhe_key_get_public (t->ax->kx_0, &msg.ephemeral_key);
4207 GNUNET_CRYPTO_ecdhe_key_get_public (t->ax->DHRs, &msg.ratchet_key);
4209 t->ephm_h = send_kx (t, &msg.header);
4210 if (CADET_TUNNEL_KEY_OK != t->estate)
4211 GCT_change_estate (t, CADET_TUNNEL_KEY_SENT);
4216 * Sends an already built and encrypted message on a tunnel, choosing the best
4217 * connection. Useful for re-queueing messages queued on a destroyed connection.
4219 * @param message Message to send. Function modifies it.
4220 * @param t Tunnel on which this message is transmitted.
4223 GCT_resend_message (const struct GNUNET_MessageHeader *message,
4224 struct CadetTunnel *t)
4226 struct CadetConnection *c;
4229 c = tunnel_get_connection (t);
4232 /* TODO queue in tunnel, marked as encrypted */
4233 LOG (GNUNET_ERROR_TYPE_DEBUG, "No connection available, dropping.\n");
4236 fwd = GCC_is_origin (c, GNUNET_YES);
4237 GNUNET_break (NULL == GCC_send_prebuilt_message (message, 0, 0, c, fwd,
4238 GNUNET_YES, NULL, NULL));
4243 * Is the tunnel directed towards the local peer?
4247 * @return #GNUNET_YES if it is loopback.
4250 GCT_is_loopback (const struct CadetTunnel *t)
4252 return (myid == GCP_get_short_id (t->peer));
4257 * Is the tunnel this path already?
4262 * @return #GNUNET_YES a connection uses this path.
4265 GCT_is_path_used (const struct CadetTunnel *t, const struct CadetPeerPath *p)
4267 struct CadetTConnection *iter;
4269 for (iter = t->connection_head; NULL != iter; iter = iter->next)
4270 if (path_equivalent (GCC_get_path (iter->c), p))
4278 * Get a cost of a path for a tunnel considering existing connections.
4281 * @param path Candidate path.
4283 * @return Cost of the path (path length + number of overlapping nodes)
4286 GCT_get_path_cost (const struct CadetTunnel *t,
4287 const struct CadetPeerPath *path)
4289 struct CadetTConnection *iter;
4290 const struct CadetPeerPath *aux;
4291 unsigned int overlap;
4299 GNUNET_assert (NULL != t);
4301 for (i = 0; i < path->length; i++)
4303 for (iter = t->connection_head; NULL != iter; iter = iter->next)
4305 aux = GCC_get_path (iter->c);
4309 for (j = 0; j < aux->length; j++)
4311 if (path->peers[i] == aux->peers[j])
4319 return path->length + overlap;
4324 * Get the static string for the peer this tunnel is directed.
4328 * @return Static string the destination peer's ID.
4331 GCT_2s (const struct CadetTunnel *t)
4336 return GCP_2s (t->peer);
4340 /******************************************************************************/
4341 /***************************** INFO/DEBUG *******************************/
4342 /******************************************************************************/
4345 ax_debug (const struct CadetTunnelAxolotl *ax, enum GNUNET_ErrorType level)
4347 struct GNUNET_CRYPTO_EcdhePublicKey pub;
4348 struct CadetTunnelSkippedKey *iter;
4351 LOG2 (level, "TTT RK\t %s\n",
4352 GNUNET_h2s ((struct GNUNET_HashCode *) &ax->RK));
4354 LOG2 (level, "TTT HKs\t %s\n",
4355 GNUNET_h2s ((struct GNUNET_HashCode *) &ax->HKs));
4356 LOG2 (level, "TTT HKr\t %s\n",
4357 GNUNET_h2s ((struct GNUNET_HashCode *) &ax->HKr));
4358 LOG2 (level, "TTT NHKs\t %s\n",
4359 GNUNET_h2s ((struct GNUNET_HashCode *) &ax->NHKs));
4360 LOG2 (level, "TTT NHKr\t %s\n",
4361 GNUNET_h2s ((struct GNUNET_HashCode *) &ax->NHKr));
4363 LOG2 (level, "TTT CKs\t %s\n",
4364 GNUNET_h2s ((struct GNUNET_HashCode *) &ax->CKs));
4365 LOG2 (level, "TTT CKr\t %s\n",
4366 GNUNET_h2s ((struct GNUNET_HashCode *) &ax->CKr));
4368 GNUNET_CRYPTO_ecdhe_key_get_public (ax_key, &pub);
4369 LOG2 (level, "TTT DHIs\t %s\n",
4370 GNUNET_h2s ((struct GNUNET_HashCode *) &pub));
4371 LOG2 (level, "TTT DHIr\t %s\n",
4372 GNUNET_h2s ((struct GNUNET_HashCode *) &ax->DHIr));
4373 GNUNET_CRYPTO_ecdhe_key_get_public (ax->DHRs, &pub);
4374 LOG2 (level, "TTT DHRs\t %s\n",
4375 GNUNET_h2s ((struct GNUNET_HashCode *) &pub));
4376 LOG2 (level, "TTT DHRr\t %s\n",
4377 GNUNET_h2s ((struct GNUNET_HashCode *) &ax->DHRr));
4379 LOG2 (level, "TTT Nr\t %u\tNs\t%u\n", ax->Nr, ax->Ns);
4380 LOG2 (level, "TTT PNs\t %u\tSkipped\t%u\n", ax->PNs, ax->skipped);
4381 LOG2 (level, "TTT Ratchet\t%u\n", ax->ratchet_flag);
4383 for (iter = ax->skipped_head; NULL != iter; iter = iter->next)
4385 LOG2 (level, "TTT HK\t %s\n",
4386 GNUNET_h2s ((struct GNUNET_HashCode *) &iter->HK));
4387 LOG2 (level, "TTT MK\t %s\n",
4388 GNUNET_h2s ((struct GNUNET_HashCode *) &iter->MK));
4393 * Log all possible info about the tunnel state.
4395 * @param t Tunnel to debug.
4396 * @param level Debug level to use.
4399 GCT_debug (const struct CadetTunnel *t, enum GNUNET_ErrorType level)
4401 struct CadetTChannel *iterch;
4402 struct CadetTConnection *iterc;
4405 do_log = GNUNET_get_log_call_status (level & (~GNUNET_ERROR_TYPE_BULK),
4407 __FILE__, __FUNCTION__, __LINE__);
4411 LOG2 (level, "TTT DEBUG TUNNEL TOWARDS %s\n", GCT_2s (t));
4412 LOG2 (level, "TTT cstate %s, estate %s\n",
4413 cstate2s (t->cstate), estate2s (t->estate));
4414 LOG2 (level, "TTT kx_ctx %p, rekey_task %u, finish task %u\n",
4415 t->kx_ctx, t->rekey_task, t->kx_ctx ? t->kx_ctx->finish_task : 0);
4416 #if DUMP_KEYS_TO_STDERR
4417 if (CADET_Axolotl == t->enc_type)
4419 ax_debug (t->ax, level);
4423 LOG2 (level, "TTT my EPHM\t %s\n",
4424 GNUNET_h2s ((struct GNUNET_HashCode *) &otr_kx_msg.ephemeral_key));
4425 LOG2 (level, "TTT peers EPHM:\t %s\n",
4426 GNUNET_h2s ((struct GNUNET_HashCode *) &t->peers_ephemeral_key));
4427 LOG2 (level, "TTT ENC key:\t %s\n",
4428 GNUNET_h2s ((struct GNUNET_HashCode *) &t->e_key));
4429 LOG2 (level, "TTT DEC key:\t %s\n",
4430 GNUNET_h2s ((struct GNUNET_HashCode *) &t->d_key));
4433 LOG2 (level, "TTT OLD ENC key:\t %s\n",
4434 GNUNET_h2s ((struct GNUNET_HashCode *) &t->kx_ctx->e_key_old));
4435 LOG2 (level, "TTT OLD DEC key:\t %s\n",
4436 GNUNET_h2s ((struct GNUNET_HashCode *) &t->kx_ctx->d_key_old));
4440 LOG2 (level, "TTT tq_head %p, tq_tail %p\n", t->tq_head, t->tq_tail);
4441 LOG2 (level, "TTT destroy %u\n", t->destroy_task);
4443 LOG2 (level, "TTT channels:\n");
4444 for (iterch = t->channel_head; NULL != iterch; iterch = iterch->next)
4446 LOG2 (level, "TTT - %s\n", GCCH_2s (iterch->ch));
4449 LOG2 (level, "TTT connections:\n");
4450 for (iterc = t->connection_head; NULL != iterc; iterc = iterc->next)
4452 GCC_debug (iterc->c, level);
4455 LOG2 (level, "TTT DEBUG TUNNEL END\n");
4460 * Iterate all tunnels.
4462 * @param iter Iterator.
4463 * @param cls Closure for @c iter.
4466 GCT_iterate_all (GNUNET_CONTAINER_PeerMapIterator iter, void *cls)
4468 GNUNET_CONTAINER_multipeermap_iterate (tunnels, iter, cls);
4473 * Count all tunnels.
4475 * @return Number of tunnels to remote peers kept by this peer.
4478 GCT_count_all (void)
4480 return GNUNET_CONTAINER_multipeermap_size (tunnels);
4485 * Iterate all connections of a tunnel.
4487 * @param t Tunnel whose connections to iterate.
4488 * @param iter Iterator.
4489 * @param cls Closure for @c iter.
4492 GCT_iterate_connections (struct CadetTunnel *t, GCT_conn_iter iter, void *cls)
4494 struct CadetTConnection *ct;
4496 for (ct = t->connection_head; NULL != ct; ct = ct->next)
4502 * Iterate all channels of a tunnel.
4504 * @param t Tunnel whose channels to iterate.
4505 * @param iter Iterator.
4506 * @param cls Closure for @c iter.
4509 GCT_iterate_channels (struct CadetTunnel *t, GCT_chan_iter iter, void *cls)
4511 struct CadetTChannel *cht;
4513 for (cht = t->channel_head; NULL != cht; cht = cht->next)
4514 iter (cls, cht->ch);