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., 51 Franklin Street, Fifth Floor,
18 Boston, MA 02110-1301, 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 MIN_TUNNEL_BUFFER 8
47 #define MAX_TUNNEL_BUFFER 64
48 #define MAX_SKIPPED_KEYS 64
49 #define MAX_KEY_GAP 256
50 #define AX_HEADER_SIZE (sizeof (uint32_t) * 2\
51 + sizeof (struct GNUNET_CRYPTO_EcdhePublicKey))
54 /******************************************************************************/
55 /******************************** STRUCTS **********************************/
56 /******************************************************************************/
60 struct CadetTChannel *next;
61 struct CadetTChannel *prev;
62 struct CadetChannel *ch;
67 * Connection list and metadata.
69 struct CadetTConnection
74 struct CadetTConnection *next;
79 struct CadetTConnection *prev;
84 struct CadetConnection *c;
87 * Creation time, to keep oldest connection alive.
89 struct GNUNET_TIME_Absolute created;
92 * Connection throughput, to keep fastest connection alive.
98 * Structure used during a Key eXchange.
100 struct CadetTunnelKXCtx
103 * Encryption ("our") old "confirmed" key, for encrypting traffic sent by us
104 * end before the key exchange is finished or times out.
106 struct GNUNET_CRYPTO_SymmetricSessionKey e_key_old;
109 * Decryption ("their") old "confirmed" key, for decrypting traffic sent by
110 * the other end before the key exchange started.
112 struct GNUNET_CRYPTO_SymmetricSessionKey d_key_old;
115 * Same as @c e_key_old, for the case of two simultaneous KX.
116 * This can happen if cadet decides to start a re-key while the peer has also
117 * started its re-key (due to network delay this is impossible to avoid).
118 * In this case, the key material generated with the peer's old ephemeral
119 * *might* (but doesn't have to) be incorrect.
120 * Since no more than two re-keys can happen simultaneously, this is enough.
122 struct GNUNET_CRYPTO_SymmetricSessionKey e_key_old2;
125 * Same as @c d_key_old, for the case described in @c e_key_old2.
127 struct GNUNET_CRYPTO_SymmetricSessionKey d_key_old2;
130 * Challenge to send and expect in the PONG.
135 * When the rekey started. One minute after this the new key will be used.
137 struct GNUNET_TIME_Absolute rekey_start_time;
140 * Task for delayed destruction of the Key eXchange context, to allow delayed
141 * messages with the old key to be decrypted successfully.
143 struct GNUNET_SCHEDULER_Task *finish_task;
147 * Encryption systems possible.
149 enum CadetTunnelEncryption
152 * Default Axolotl system.
157 * Fallback OTR-style encryption.
163 * Struct to old keys for skipped messages while advancing the Axolotl ratchet.
165 struct CadetTunnelSkippedKey
170 struct CadetTunnelSkippedKey *next;
175 struct CadetTunnelSkippedKey *prev;
178 * When was this key stored (for timeout).
180 struct GNUNET_TIME_Absolute timestamp;
185 struct GNUNET_CRYPTO_SymmetricSessionKey HK;
190 struct GNUNET_CRYPTO_SymmetricSessionKey MK;
195 * Axolotl data, according to https://github.com/trevp/axolotl/wiki .
197 struct CadetTunnelAxolotl
200 * A (double linked) list of stored message keys and associated header keys
201 * for "skipped" messages, i.e. messages that have not been
202 * received despite the reception of more recent messages, (head).
204 struct CadetTunnelSkippedKey *skipped_head;
207 * Skipped messages' keys DLL, tail.
209 struct CadetTunnelSkippedKey *skipped_tail;
212 * Elements in @a skipped_head <-> @a skipped_tail.
214 unsigned int skipped;
217 * 32-byte root key which gets updated by DH ratchet.
219 struct GNUNET_CRYPTO_SymmetricSessionKey RK;
222 * 32-byte header key (send).
224 struct GNUNET_CRYPTO_SymmetricSessionKey HKs;
227 * 32-byte header key (recv)
229 struct GNUNET_CRYPTO_SymmetricSessionKey HKr;
232 * 32-byte next header key (send).
234 struct GNUNET_CRYPTO_SymmetricSessionKey NHKs;
237 * 32-byte next header key (recv).
239 struct GNUNET_CRYPTO_SymmetricSessionKey NHKr;
242 * 32-byte chain keys (used for forward-secrecy updating, send).
244 struct GNUNET_CRYPTO_SymmetricSessionKey CKs;
247 * 32-byte chain keys (used for forward-secrecy updating, recv).
249 struct GNUNET_CRYPTO_SymmetricSessionKey CKr;
252 * ECDH for key exchange (A0 / B0).
254 struct GNUNET_CRYPTO_EcdhePrivateKey *kx_0;
257 * ECDH Ratchet key (send).
259 struct GNUNET_CRYPTO_EcdhePrivateKey *DHRs;
262 * ECDH Ratchet key (recv).
264 struct GNUNET_CRYPTO_EcdhePublicKey DHRr;
267 * Message number (reset to 0 with each new ratchet, next message to send).
272 * Message number (reset to 0 with each new ratchet, next message to recv).
277 * Previous message numbers (# of msgs sent under prev ratchet)
282 * True (#GNUNET_YES) if we have to send a new ratchet key in next msg.
287 * Number of messages recieved since our last ratchet advance.
288 * - If this counter = 0, we cannot send a new ratchet key in next msg.
289 * - If this counter > 0, we can (but don't yet have to) send a new key.
291 unsigned int ratchet_allowed;
294 * Number of messages recieved since our last ratchet advance.
295 * - If this counter = 0, we cannot send a new ratchet key in next msg.
296 * - If this counter > 0, we can (but don't yet have to) send a new key.
298 unsigned int ratchet_counter;
301 * When does this ratchet expire and a new one is triggered.
303 struct GNUNET_TIME_Absolute ratchet_expiration;
307 * Struct containing all information regarding a tunnel to a peer.
312 * Endpoint of the tunnel.
314 struct CadetPeer *peer;
317 * Type of encryption used in the tunnel.
319 enum CadetTunnelEncryption enc_type;
324 struct CadetTunnelAxolotl *ax;
327 * State of the tunnel connectivity.
329 enum CadetTunnelCState cstate;
332 * State of the tunnel encryption.
334 enum CadetTunnelEState estate;
337 * Key eXchange context.
339 struct CadetTunnelKXCtx *kx_ctx;
342 * Peer's ephemeral key, to recreate @c e_key and @c d_key when own ephemeral
345 struct GNUNET_CRYPTO_EcdhePublicKey peers_ephemeral_key;
348 * Encryption ("our") key. It is only "confirmed" if kx_ctx is NULL.
350 struct GNUNET_CRYPTO_SymmetricSessionKey e_key;
353 * Decryption ("their") key. It is only "confirmed" if kx_ctx is NULL.
355 struct GNUNET_CRYPTO_SymmetricSessionKey d_key;
358 * Task to start the rekey process.
360 struct GNUNET_SCHEDULER_Task * rekey_task;
363 * Paths that are actively used to reach the destination peer.
365 struct CadetTConnection *connection_head;
366 struct CadetTConnection *connection_tail;
369 * Next connection number.
374 * Channels inside this tunnel.
376 struct CadetTChannel *channel_head;
377 struct CadetTChannel *channel_tail;
380 * Channel ID for the next created channel.
382 CADET_ChannelNumber next_chid;
385 * Destroy flag: if true, destroy on last message.
387 struct GNUNET_SCHEDULER_Task * destroy_task;
390 * Queued messages, to transmit once tunnel gets connected.
392 struct CadetTunnelDelayed *tq_head;
393 struct CadetTunnelDelayed *tq_tail;
396 * Task to trim connections if too many are present.
398 struct GNUNET_SCHEDULER_Task * trim_connections_task;
401 * Ephemeral message in the queue (to avoid queueing more than one).
403 struct CadetConnectionQueue *ephm_h;
406 * Pong message in the queue.
408 struct CadetConnectionQueue *pong_h;
413 * Struct used to save messages in a non-ready tunnel to send once connected.
415 struct CadetTunnelDelayed
420 struct CadetTunnelDelayed *next;
421 struct CadetTunnelDelayed *prev;
426 struct CadetTunnel *t;
429 * Tunnel queue given to the channel to cancel request. Update on send_queued.
431 struct CadetTunnelQueue *tq;
436 /* struct GNUNET_MessageHeader *msg; */
441 * Handle for messages queued but not yet sent.
443 struct CadetTunnelQueue
446 * Connection queue handle, to cancel if necessary.
448 struct CadetConnectionQueue *cq;
451 * Handle in case message hasn't been given to a connection yet.
453 struct CadetTunnelDelayed *tqd;
456 * Continuation to call once sent.
461 * Closure for @c cont.
467 /******************************************************************************/
468 /******************************* GLOBALS ***********************************/
469 /******************************************************************************/
472 * Global handle to the statistics service.
474 extern struct GNUNET_STATISTICS_Handle *stats;
477 * Local peer own ID (memory efficient handle).
479 extern GNUNET_PEER_Id myid;
482 * Local peer own ID (full value).
484 extern struct GNUNET_PeerIdentity my_full_id;
488 * Don't try to recover tunnels if shutting down.
490 extern int shutting_down;
494 * Set of all tunnels, in order to trigger a new exchange on rekey.
495 * Indexed by peer's ID.
497 static struct GNUNET_CONTAINER_MultiPeerMap *tunnels;
500 * Default TTL for payload packets.
502 static unsigned long long default_ttl;
505 * Own Peer ID private key.
507 const static struct GNUNET_CRYPTO_EddsaPrivateKey *id_key;
510 /******************************** AXOLOTL ************************************/
513 * How many messages are needed to trigger a ratchet advance.
515 static unsigned long long ratchet_messages;
518 * How long until we trigger a ratched advance.
520 static struct GNUNET_TIME_Relative ratchet_time;
523 /******************************** OTR ***********************************/
526 * Own global OTR ephemeral private key.
528 static struct GNUNET_CRYPTO_EcdhePrivateKey *otr_ephemeral_key;
531 * Cached message used to perform a OTR key exchange.
533 static struct GNUNET_CADET_KX_Ephemeral otr_kx_msg;
536 * Task to generate a new OTR ephemeral key.
538 static struct GNUNET_SCHEDULER_Task *rekey_task;
543 static struct GNUNET_TIME_Relative rekey_period;
546 /******************************************************************************/
547 /******************************** STATIC ***********************************/
548 /******************************************************************************/
551 * Get string description for tunnel connectivity state.
553 * @param cs Tunnel state.
555 * @return String representation.
558 cstate2s (enum CadetTunnelCState cs)
564 case CADET_TUNNEL_NEW:
565 return "CADET_TUNNEL_NEW";
566 case CADET_TUNNEL_SEARCHING:
567 return "CADET_TUNNEL_SEARCHING";
568 case CADET_TUNNEL_WAITING:
569 return "CADET_TUNNEL_WAITING";
570 case CADET_TUNNEL_READY:
571 return "CADET_TUNNEL_READY";
572 case CADET_TUNNEL_SHUTDOWN:
573 return "CADET_TUNNEL_SHUTDOWN";
575 SPRINTF (buf, "%u (UNKNOWN STATE)", cs);
583 * Get string description for tunnel encryption state.
585 * @param es Tunnel state.
587 * @return String representation.
590 estate2s (enum CadetTunnelEState es)
596 case CADET_TUNNEL_KEY_UNINITIALIZED:
597 return "CADET_TUNNEL_KEY_UNINITIALIZED";
598 case CADET_TUNNEL_KEY_SENT:
599 return "CADET_TUNNEL_KEY_SENT";
600 case CADET_TUNNEL_KEY_PING:
601 return "CADET_TUNNEL_KEY_PING";
602 case CADET_TUNNEL_KEY_OK:
603 return "CADET_TUNNEL_KEY_OK";
604 case CADET_TUNNEL_KEY_REKEY:
605 return "CADET_TUNNEL_KEY_REKEY";
607 SPRINTF (buf, "%u (UNKNOWN STATE)", es);
615 * @brief Check if tunnel is ready to send traffic.
617 * Tunnel must be connected and with encryption correctly set up.
619 * @param t Tunnel to check.
621 * @return #GNUNET_YES if ready, #GNUNET_NO otherwise
624 is_ready (struct CadetTunnel *t)
630 conn_ok = CADET_TUNNEL_READY == t->cstate;
631 enc_ok = CADET_TUNNEL_KEY_OK == t->estate
632 || CADET_TUNNEL_KEY_REKEY == t->estate
633 || (CADET_TUNNEL_KEY_PING == t->estate
634 && CADET_Axolotl == t->enc_type);
635 ready = conn_ok && enc_ok;
636 ready = ready || GCT_is_loopback (t);
642 * Check if a key is invalid (NULL pointer or all 0)
644 * @param key Key to check.
646 * @return #GNUNET_YES if key is null, #GNUNET_NO if exists and is not 0.
649 is_key_null (struct GNUNET_CRYPTO_SymmetricSessionKey *key)
651 struct GNUNET_CRYPTO_SymmetricSessionKey null_key;
656 memset (&null_key, 0, sizeof (null_key));
657 if (0 == memcmp (key, &null_key, sizeof (null_key)))
664 * Ephemeral key message purpose size.
666 * @return Size of the part of the ephemeral key message that must be signed.
669 ephemeral_purpose_size (void)
671 return sizeof (struct GNUNET_CRYPTO_EccSignaturePurpose) +
672 sizeof (struct GNUNET_TIME_AbsoluteNBO) +
673 sizeof (struct GNUNET_TIME_AbsoluteNBO) +
674 sizeof (struct GNUNET_CRYPTO_EcdhePublicKey) +
675 sizeof (struct GNUNET_PeerIdentity);
680 * Size of the encrypted part of a ping message.
682 * @return Size of the encrypted part of a ping message.
685 ping_encryption_size (void)
687 return sizeof (uint32_t);
692 * Get the channel's buffer. ONLY FOR NON-LOOPBACK CHANNELS!!
694 * @param tch Tunnel's channel handle.
696 * @return Amount of messages the channel can still buffer towards the client.
699 get_channel_buffer (const struct CadetTChannel *tch)
703 /* If channel is incoming, is terminal in the FWD direction and fwd is YES */
704 fwd = GCCH_is_terminal (tch->ch, GNUNET_YES);
706 return GCCH_get_buffer (tch->ch, fwd);
711 * Get the channel's allowance status.
713 * @param tch Tunnel's channel handle.
715 * @return #GNUNET_YES if we allowed the client to send data to us.
718 get_channel_allowed (const struct CadetTChannel *tch)
722 /* If channel is outgoing, is origin in the FWD direction and fwd is YES */
723 fwd = GCCH_is_origin (tch->ch, GNUNET_YES);
725 return GCCH_get_allowed (tch->ch, fwd);
730 * Get the connection's buffer.
732 * @param tc Tunnel's connection handle.
734 * @return Amount of messages the connection can still buffer.
737 get_connection_buffer (const struct CadetTConnection *tc)
741 /* If connection is outgoing, is origin in the FWD direction and fwd is YES */
742 fwd = GCC_is_origin (tc->c, GNUNET_YES);
744 return GCC_get_buffer (tc->c, fwd);
749 * Get the connection's allowance.
751 * @param tc Tunnel's connection handle.
753 * @return Amount of messages we have allowed the next peer to send us.
756 get_connection_allowed (const struct CadetTConnection *tc)
760 /* If connection is outgoing, is origin in the FWD direction and fwd is YES */
761 fwd = GCC_is_origin (tc->c, GNUNET_YES);
763 return GCC_get_allowed (tc->c, fwd);
768 * Check that a ephemeral key message s well formed and correctly signed.
770 * @param t Tunnel on which the message came.
771 * @param msg The ephemeral key message.
773 * @return #GNUNET_OK if message is fine, #GNUNET_SYSERR otherwise.
776 check_ephemeral (struct CadetTunnel *t,
777 const struct GNUNET_CADET_KX_Ephemeral *msg)
779 /* Check message size */
780 if (ntohs (msg->header.size) != sizeof (struct GNUNET_CADET_KX_Ephemeral))
782 /* This is probably an old "MESH" version. */
783 LOG (GNUNET_ERROR_TYPE_INFO,
784 "Expected ephemeral of size %u, got %u\n",
785 sizeof (struct GNUNET_CADET_KX_Ephemeral),
786 ntohs (msg->header.size));
787 return GNUNET_SYSERR;
790 /* Check signature size */
791 if (ntohl (msg->purpose.size) != ephemeral_purpose_size ())
793 LOG (GNUNET_ERROR_TYPE_WARNING,
794 "Expected signature purpose of size %u, got %u\n",
795 ephemeral_purpose_size (),
796 ntohs (msg->purpose.size));
797 return GNUNET_SYSERR;
801 if (0 != memcmp (&msg->origin_identity,
802 GCP_get_id (t->peer),
803 sizeof (struct GNUNET_PeerIdentity)))
805 LOG (GNUNET_ERROR_TYPE_WARNING,
806 "Unexpected origin, got %s\n",
807 GNUNET_i2s (&msg->origin_identity));
808 return GNUNET_SYSERR;
811 /* Check signature */
813 GNUNET_CRYPTO_eddsa_verify (GNUNET_SIGNATURE_PURPOSE_CADET_KX,
816 &msg->origin_identity.public_key))
818 LOG (GNUNET_ERROR_TYPE_WARNING, "Signature invalid\n");
819 return GNUNET_SYSERR;
827 * Select the best key to use for encryption (send), based on KX status.
829 * Normally, return the current key. If there is a KX in progress and the old
830 * key is fresh enough, return the old key.
832 * @param t Tunnel to choose the key from.
834 * @return The optimal key to encrypt/hmac outgoing traffic.
836 static const struct GNUNET_CRYPTO_SymmetricSessionKey *
837 select_key (const struct CadetTunnel *t)
839 const struct GNUNET_CRYPTO_SymmetricSessionKey *key;
841 if (NULL != t->kx_ctx
842 && NULL == t->kx_ctx->finish_task)
844 struct GNUNET_TIME_Relative age;
846 age = GNUNET_TIME_absolute_get_duration (t->kx_ctx->rekey_start_time);
847 LOG (GNUNET_ERROR_TYPE_DEBUG,
848 " key exchange in progress, started %s ago\n",
849 GNUNET_STRINGS_relative_time_to_string (age, GNUNET_YES));
850 // FIXME make duration of old keys configurable
851 if (age.rel_value_us < GNUNET_TIME_UNIT_MINUTES.rel_value_us)
853 LOG (GNUNET_ERROR_TYPE_DEBUG, " using old key\n");
854 key = &t->kx_ctx->e_key_old;
858 LOG (GNUNET_ERROR_TYPE_DEBUG, " using new key (old key too old)\n");
864 LOG (GNUNET_ERROR_TYPE_DEBUG, " no KX: using current key\n");
872 * Create a new Axolotl ephemeral (ratchet) key.
877 new_ephemeral (struct CadetTunnel *t)
879 GNUNET_free_non_null (t->ax->DHRs);
880 t->ax->DHRs = GNUNET_CRYPTO_ecdhe_key_create();
887 * @param plaintext Content to HMAC.
888 * @param size Size of @c plaintext.
889 * @param iv Initialization vector for the message.
890 * @param key Key to use.
891 * @param hmac[out] Destination to store the HMAC.
894 t_hmac (const void *plaintext, size_t size,
895 uint32_t iv, const struct GNUNET_CRYPTO_SymmetricSessionKey *key,
896 struct GNUNET_CADET_Hash *hmac)
898 static const char ctx[] = "cadet authentication key";
899 struct GNUNET_CRYPTO_AuthKey auth_key;
900 struct GNUNET_HashCode hash;
902 #if DUMP_KEYS_TO_STDERR
903 LOG (GNUNET_ERROR_TYPE_INFO, " HMAC %u bytes with key %s\n", size,
904 GNUNET_i2s ((struct GNUNET_PeerIdentity *) key));
906 GNUNET_CRYPTO_hmac_derive_key (&auth_key, key,
911 /* Two step: CADET_Hash is only 256 bits, HashCode is 512. */
912 GNUNET_CRYPTO_hmac (&auth_key, plaintext, size, &hash);
913 memcpy (hmac, &hash, sizeof (*hmac));
918 * Encrypt daforce_newest_keyta with the tunnel key.
920 * @param t Tunnel whose key to use.
921 * @param dst Destination for the encrypted data.
922 * @param src Source of the plaintext. Can overlap with @c dst.
923 * @param size Size of the plaintext.
924 * @param iv Initialization Vector to use.
925 * @param force_newest_key Force the use of the newest key, otherwise
926 * CADET will use the old key when allowed.
927 * This can happen in the case when a KX is going on
928 * and the old one hasn't expired.
931 t_encrypt (struct CadetTunnel *t, void *dst, const void *src,
932 size_t size, uint32_t iv, int force_newest_key)
934 struct GNUNET_CRYPTO_SymmetricInitializationVector siv;
935 const struct GNUNET_CRYPTO_SymmetricSessionKey *key;
938 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_encrypt start\n");
940 key = GNUNET_YES == force_newest_key ? &t->e_key : select_key (t);
941 #if DUMP_KEYS_TO_STDERR
942 LOG (GNUNET_ERROR_TYPE_INFO, " ENC with key %s\n",
943 GNUNET_i2s ((struct GNUNET_PeerIdentity *) key));
945 GNUNET_CRYPTO_symmetric_derive_iv (&siv, key, &iv, sizeof (iv), NULL);
946 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_encrypt IV derived\n");
947 out_size = GNUNET_CRYPTO_symmetric_encrypt (src, size, key, &siv, dst);
948 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_encrypt end\n");
957 * @param key Key to use.
958 * @param hash[out] Resulting HMAC.
959 * @param source Source key material (data to HMAC).
960 * @param len Length of @a source.
963 t_ax_hmac_hash (struct GNUNET_CRYPTO_SymmetricSessionKey *key,
964 struct GNUNET_HashCode *hash,
965 void *source, unsigned int len)
967 static const char ctx[] = "axolotl HMAC-HASH";
968 struct GNUNET_CRYPTO_AuthKey auth_key;
970 GNUNET_CRYPTO_hmac_derive_key (&auth_key, key,
973 GNUNET_CRYPTO_hmac (&auth_key, source, len, hash);
978 * Derive a key from a HMAC-HASH.
980 * @param key Key to use for the HMAC.
981 * @param out Key to generate.
982 * @param source Source key material (data to HMAC).
983 * @param len Length of @a source.
986 t_hmac_derive_key (struct GNUNET_CRYPTO_SymmetricSessionKey *key,
987 struct GNUNET_CRYPTO_SymmetricSessionKey *out,
988 void *source, unsigned int len)
990 static const char ctx[] = "axolotl derive key";
991 struct GNUNET_HashCode h;
993 t_ax_hmac_hash (key, &h, source, len);
994 GNUNET_CRYPTO_kdf (out, sizeof (*out), ctx, sizeof (ctx),
995 &h, sizeof (h), NULL);
1000 * Encrypt data with the axolotl tunnel key.
1002 * @param t Tunnel whose key to use.
1003 * @param dst Destination for the encrypted data.
1004 * @param src Source of the plaintext. Can overlap with @c dst.
1005 * @param size Size of the plaintext.
1007 * @return Size of the encrypted data.
1010 t_ax_encrypt (struct CadetTunnel *t, void *dst, const void *src, size_t size)
1012 struct GNUNET_CRYPTO_SymmetricSessionKey MK;
1013 struct GNUNET_CRYPTO_SymmetricInitializationVector iv;
1014 struct CadetTunnelAxolotl *ax;
1017 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_ax_encrypt start\n");
1021 ax->ratchet_counter++;
1022 if (GNUNET_YES == ax->ratchet_allowed
1023 && (ratchet_messages <= ax->ratchet_counter
1024 || 0 == GNUNET_TIME_absolute_get_remaining (ax->ratchet_expiration).rel_value_us))
1026 ax->ratchet_flag = GNUNET_YES;
1029 if (GNUNET_YES == ax->ratchet_flag)
1031 /* Advance ratchet */
1032 struct GNUNET_CRYPTO_SymmetricSessionKey keys[3];
1033 struct GNUNET_HashCode dh;
1034 struct GNUNET_HashCode hmac;
1035 static const char ctx[] = "axolotl ratchet";
1040 /* RK, NHKs, CKs = KDF( HMAC-HASH(RK, DH(DHRs, DHRr)) ) */
1041 GNUNET_CRYPTO_ecc_ecdh (ax->DHRs, &ax->DHRr, &dh);
1042 t_ax_hmac_hash (&ax->RK, &hmac, &dh, sizeof (dh));
1043 GNUNET_CRYPTO_kdf (keys, sizeof (keys), ctx, sizeof (ctx),
1044 &hmac, sizeof (hmac), NULL);
1051 ax->ratchet_flag = GNUNET_NO;
1052 ax->ratchet_allowed = GNUNET_NO;
1053 ax->ratchet_counter = 0;
1054 ax->ratchet_expiration =
1055 GNUNET_TIME_absolute_add (GNUNET_TIME_absolute_get(), ratchet_time);
1058 t_hmac_derive_key (&ax->CKs, &MK, "0", 1);
1059 GNUNET_CRYPTO_symmetric_derive_iv (&iv, &MK, NULL, 0, NULL);
1061 #if DUMP_KEYS_TO_STDERR
1062 LOG (GNUNET_ERROR_TYPE_INFO, " CKs: %s\n",
1063 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &ax->CKs));
1064 LOG (GNUNET_ERROR_TYPE_INFO, " AX_ENC with key %u: %s\n", ax->Ns,
1065 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &MK));
1068 out_size = GNUNET_CRYPTO_symmetric_encrypt (src, size, &MK, &iv, dst);
1070 t_hmac_derive_key (&ax->CKs, &ax->CKs, "1", 1);
1072 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_ax_encrypt end\n");
1079 * Decrypt data with the axolotl tunnel key.
1081 * @param t Tunnel whose key to use.
1082 * @param dst Destination for the decrypted data.
1083 * @param src Source of the ciphertext. Can overlap with @c dst.
1084 * @param size Size of the ciphertext.
1086 * @return Size of the decrypted data.
1089 t_ax_decrypt (struct CadetTunnel *t, void *dst, const void *src, size_t size)
1091 struct GNUNET_CRYPTO_SymmetricSessionKey MK;
1092 struct GNUNET_CRYPTO_SymmetricInitializationVector iv;
1093 struct CadetTunnelAxolotl *ax;
1096 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_ax_decrypt start\n");
1100 t_hmac_derive_key (&ax->CKr, &MK, "0", 1);
1101 GNUNET_CRYPTO_symmetric_derive_iv (&iv, &MK, NULL, 0, NULL);
1103 #if DUMP_KEYS_TO_STDERR
1104 LOG (GNUNET_ERROR_TYPE_INFO, " CKr: %s\n",
1105 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &ax->CKr));
1106 LOG (GNUNET_ERROR_TYPE_INFO, " AX_DEC with key %u: %s\n", ax->Nr,
1107 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &MK));
1110 GNUNET_assert (size >= sizeof (struct GNUNET_MessageHeader));
1111 out_size = GNUNET_CRYPTO_symmetric_decrypt (src, size, &MK, &iv, dst);
1112 GNUNET_assert (out_size == size);
1114 t_hmac_derive_key (&ax->CKr, &ax->CKr, "1", 1);
1116 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_ax_decrypt end\n");
1123 * Encrypt header with the axolotl header key.
1125 * @param t Tunnel whose key to use.
1126 * @param msg Message whose header to encrypt.
1129 t_h_encrypt (struct CadetTunnel *t, struct GNUNET_CADET_AX *msg)
1131 struct GNUNET_CRYPTO_SymmetricInitializationVector iv;
1132 struct CadetTunnelAxolotl *ax;
1135 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_h_encrypt start\n");
1138 GNUNET_CRYPTO_symmetric_derive_iv (&iv, &ax->HKs, NULL, 0, NULL);
1140 #if DUMP_KEYS_TO_STDERR
1141 LOG (GNUNET_ERROR_TYPE_INFO, " AX_ENC_H with key %s\n",
1142 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &ax->HKs));
1145 out_size = GNUNET_CRYPTO_symmetric_encrypt (&msg->Ns, AX_HEADER_SIZE,
1146 &ax->HKs, &iv, &msg->Ns);
1148 GNUNET_assert (AX_HEADER_SIZE == out_size);
1150 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_ax_encrypt end\n");
1155 * Decrypt header with the current axolotl header key.
1157 * @param t Tunnel whose current ax HK to use.
1158 * @param src Message whose header to decrypt.
1159 * @param dst Where to decrypt header to.
1162 t_h_decrypt (struct CadetTunnel *t, const struct GNUNET_CADET_AX *src,
1163 struct GNUNET_CADET_AX *dst)
1165 struct GNUNET_CRYPTO_SymmetricInitializationVector iv;
1166 struct CadetTunnelAxolotl *ax;
1169 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_h_decrypt start\n");
1172 GNUNET_CRYPTO_symmetric_derive_iv (&iv, &ax->HKr, NULL, 0, NULL);
1174 #if DUMP_KEYS_TO_STDERR
1175 LOG (GNUNET_ERROR_TYPE_INFO, " AX_DEC_H with key %s\n",
1176 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &ax->HKr));
1179 out_size = GNUNET_CRYPTO_symmetric_decrypt (&src->Ns, AX_HEADER_SIZE,
1180 &ax->HKr, &iv, &dst->Ns);
1182 GNUNET_assert (AX_HEADER_SIZE == out_size);
1184 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_ax_decrypt end\n");
1189 * Decrypt and verify data with the appropriate tunnel key.
1191 * @param key Key to use.
1192 * @param dst Destination for the plaintext.
1193 * @param src Source of the encrypted data. Can overlap with @c dst.
1194 * @param size Size of the encrypted data.
1195 * @param iv Initialization Vector to use.
1197 * @return Size of the decrypted data, -1 if an error was encountered.
1200 decrypt (const struct GNUNET_CRYPTO_SymmetricSessionKey *key,
1201 void *dst, const void *src, size_t size, uint32_t iv)
1203 struct GNUNET_CRYPTO_SymmetricInitializationVector siv;
1206 LOG (GNUNET_ERROR_TYPE_DEBUG, " decrypt start\n");
1207 LOG (GNUNET_ERROR_TYPE_DEBUG, " decrypt iv\n");
1208 GNUNET_CRYPTO_symmetric_derive_iv (&siv, key, &iv, sizeof (iv), NULL);
1209 LOG (GNUNET_ERROR_TYPE_DEBUG, " decrypt iv done\n");
1210 out_size = GNUNET_CRYPTO_symmetric_decrypt (src, size, key, &siv, dst);
1211 LOG (GNUNET_ERROR_TYPE_DEBUG, " decrypt end\n");
1218 * Decrypt and verify data with the most recent tunnel key.
1220 * @param t Tunnel whose key to use.
1221 * @param dst Destination for the plaintext.
1222 * @param src Source of the encrypted data. Can overlap with @c dst.
1223 * @param size Size of the encrypted data.
1224 * @param iv Initialization Vector to use.
1226 * @return Size of the decrypted data, -1 if an error was encountered.
1229 t_decrypt (struct CadetTunnel *t, void *dst, const void *src,
1230 size_t size, uint32_t iv)
1234 #if DUMP_KEYS_TO_STDERR
1235 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_decrypt with %s\n",
1236 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &t->d_key));
1238 if (CADET_TUNNEL_KEY_UNINITIALIZED == t->estate)
1240 GNUNET_STATISTICS_update (stats, "# non decryptable data", 1, GNUNET_NO);
1241 LOG (GNUNET_ERROR_TYPE_WARNING,
1242 "got data on %s without a valid key\n",
1244 GCT_debug (t, GNUNET_ERROR_TYPE_WARNING);
1248 out_size = decrypt (&t->d_key, dst, src, size, iv);
1255 * Decrypt and verify data with the appropriate tunnel key and verify that the
1256 * data has not been altered since it was sent by the remote peer.
1258 * @param t Tunnel whose key to use.
1259 * @param dst Destination for the plaintext.
1260 * @param src Source of the encrypted data. Can overlap with @c dst.
1261 * @param size Size of the encrypted data.
1262 * @param iv Initialization Vector to use.
1263 * @param msg_hmac HMAC of the message, cannot be NULL.
1265 * @return Size of the decrypted data, -1 if an error was encountered.
1268 t_decrypt_and_validate (struct CadetTunnel *t,
1269 void *dst, const void *src,
1270 size_t size, uint32_t iv,
1271 const struct GNUNET_CADET_Hash *msg_hmac)
1273 struct GNUNET_CRYPTO_SymmetricSessionKey *key;
1274 struct GNUNET_CADET_Hash hmac;
1277 /* Try primary (newest) key */
1279 decrypted_size = decrypt (key, dst, src, size, iv);
1280 t_hmac (src, size, iv, key, &hmac);
1281 if (0 == memcmp (msg_hmac, &hmac, sizeof (hmac)))
1282 return decrypted_size;
1284 /* If no key exchange is going on, we just failed. */
1285 if (NULL == t->kx_ctx)
1287 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
1288 "Failed checksum validation on tunnel %s with no KX\n",
1290 GNUNET_STATISTICS_update (stats, "# wrong HMAC no KX", 1, GNUNET_NO);
1294 /* Try secondary key, from previous KX period. */
1295 key = &t->kx_ctx->d_key_old;
1296 decrypted_size = decrypt (key, dst, src, size, iv);
1297 t_hmac (src, size, iv, key, &hmac);
1298 if (0 == memcmp (msg_hmac, &hmac, sizeof (hmac)))
1299 return decrypted_size;
1301 /* Hail Mary, try tertiary, key, in case of parallel re-keys. */
1302 key = &t->kx_ctx->d_key_old2;
1303 decrypted_size = decrypt (key, dst, src, size, iv);
1304 t_hmac (src, size, iv, key, &hmac);
1305 if (0 == memcmp (msg_hmac, &hmac, sizeof (hmac)))
1306 return decrypted_size;
1308 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
1309 "Failed checksum validation on tunnel %s with KX\n",
1311 GNUNET_STATISTICS_update (stats, "# wrong HMAC with KX", 1, GNUNET_NO);
1317 * Decrypt and verify data with the appropriate tunnel key and verify that the
1318 * data has not been altered since it was sent by the remote peer.
1320 * @param t Tunnel whose key to use.
1321 * @param dst Destination for the plaintext.
1322 * @param src Source of the message. Can overlap with @c dst.
1323 * @param size Size of the message.
1325 * @return Size of the decrypted data, -1 if an error was encountered.
1328 try_old_ax_keys (struct CadetTunnel *t, struct GNUNET_CADET_AX *dst,
1329 const struct GNUNET_CADET_AX *src, size_t size)
1331 struct CadetTunnelSkippedKey *key;
1332 struct GNUNET_CADET_Hash hmac;
1333 struct GNUNET_CRYPTO_SymmetricInitializationVector iv;
1338 for (key = t->ax->skipped_head; NULL != key; key = key->next)
1340 t_hmac (&src->Ns, AX_HEADER_SIZE, 0, &key->HK, &hmac);
1341 if (0 != memcmp (&hmac, &src->hmac, sizeof (hmac)))
1347 #if DUMP_KEYS_TO_STDERR
1348 LOG (GNUNET_ERROR_TYPE_INFO, " AX_DEC with skipped key %s\n",
1349 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &key->MK));
1352 GNUNET_assert (size > sizeof (struct GNUNET_CADET_AX));
1353 len = size - sizeof (struct GNUNET_CADET_AX);
1354 GNUNET_CRYPTO_symmetric_derive_iv (&iv, &key->MK, NULL, 0, NULL);
1355 res = GNUNET_CRYPTO_symmetric_decrypt (&src[1], len, &key->MK, &iv, &dst[1]);
1357 GNUNET_CONTAINER_DLL_remove (t->ax->skipped_head, t->ax->skipped_tail, key);
1366 * Delete a key from the list of skipped keys.
1368 * @param t Tunnel to delete from.
1369 * @param HKr Header Key to use.
1372 store_skipped_key (struct CadetTunnel *t,
1373 const struct GNUNET_CRYPTO_SymmetricSessionKey *HKr)
1375 struct CadetTunnelSkippedKey *key;
1377 key = GNUNET_new (struct CadetTunnelSkippedKey);
1378 key->timestamp = GNUNET_TIME_absolute_get ();
1379 t_hmac_derive_key (&t->ax->CKr, &key->MK, "0", 1);
1380 #if DUMP_KEYS_TO_STDERR
1381 LOG (GNUNET_ERROR_TYPE_INFO, " storing MK for Nr %u: %s\n",
1382 t->ax->Nr, GNUNET_i2s ((struct GNUNET_PeerIdentity *) &key->MK));
1383 LOG (GNUNET_ERROR_TYPE_INFO, " for CKr: %s\n",
1384 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &t->ax->CKr));
1386 t_hmac_derive_key (&t->ax->CKr, &t->ax->CKr, "1", 1);
1387 GNUNET_CONTAINER_DLL_insert (t->ax->skipped_head, t->ax->skipped_tail, key);
1394 * Delete a key from the list of skipped keys.
1396 * @param t Tunnel to delete from.
1397 * @param key Key to delete.
1400 delete_skipped_key (struct CadetTunnel *t, struct CadetTunnelSkippedKey *key)
1402 GNUNET_CONTAINER_DLL_remove (t->ax->skipped_head, t->ax->skipped_tail, key);
1409 * Stage skipped AX keys and calculate the message key.
1411 * Stores each HK and MK for skipped messages.
1413 * @param t Tunnel where to stage the keys.
1414 * @param HKr Header key.
1415 * @param Np Received meesage number.
1418 store_ax_keys (struct CadetTunnel *t,
1419 const struct GNUNET_CRYPTO_SymmetricSessionKey *HKr,
1424 gap = Np - t->ax->Nr;
1425 if (MAX_KEY_GAP < gap || 0 > gap)
1427 /* Avoid DoS (forcing peer to do 2*33 chain HMAC operations) */
1428 /* TODO: start new key exchange on return */
1429 GNUNET_break_op (0);
1433 while (t->ax->Nr < Np)
1434 store_skipped_key (t, HKr);
1436 while (t->ax->skipped > MAX_SKIPPED_KEYS)
1437 delete_skipped_key (t, t->ax->skipped_tail);
1442 * Decrypt and verify data with the appropriate tunnel key and verify that the
1443 * data has not been altered since it was sent by the remote peer.
1445 * @param t Tunnel whose key to use.
1446 * @param dst Destination for the plaintext.
1447 * @param src Source of the message. Can overlap with @c dst.
1448 * @param size Size of the message.
1450 * @return Size of the decrypted data, -1 if an error was encountered.
1453 t_ax_decrypt_and_validate (struct CadetTunnel *t, void *dst,
1454 const struct GNUNET_CADET_AX *src, size_t size)
1456 struct CadetTunnelAxolotl *ax;
1457 struct GNUNET_CADET_Hash msg_hmac;
1458 struct GNUNET_HashCode hmac;
1459 struct GNUNET_CADET_AX *dstmsg;
1467 esize = size - sizeof (struct GNUNET_CADET_AX);
1472 /* Try current HK */
1473 t_hmac (&src->Ns, AX_HEADER_SIZE + esize, 0, &ax->HKr, &msg_hmac);
1474 if (0 != memcmp (&msg_hmac, &src->hmac, sizeof (msg_hmac)))
1476 static const char ctx[] = "axolotl ratchet";
1477 struct GNUNET_CRYPTO_SymmetricSessionKey keys[3]; /* RKp, NHKp, CKp */
1478 struct GNUNET_CRYPTO_SymmetricSessionKey HK;
1479 struct GNUNET_HashCode dh;
1480 struct GNUNET_CRYPTO_EcdhePublicKey *DHRp;
1483 t_hmac (&src->Ns, AX_HEADER_SIZE + esize, 0, &ax->NHKr, &msg_hmac);
1484 if (0 != memcmp (&msg_hmac, &src->hmac, sizeof (msg_hmac)))
1486 /* Try the skipped keys, if that fails, we're out of luck. */
1487 return try_old_ax_keys (t, dst, src, size);
1489 LOG (GNUNET_ERROR_TYPE_INFO, "next HK\n");
1493 t_h_decrypt (t, src, dstmsg);
1494 Np = ntohl (dstmsg->Ns);
1495 PNp = ntohl (dstmsg->PNs);
1496 DHRp = &dstmsg->DHRs;
1497 store_ax_keys (t, &HK, PNp);
1499 /* RKp, NHKp, CKp = KDF (HMAC-HASH (RK, DH (DHRp, DHRs))) */
1500 GNUNET_CRYPTO_ecc_ecdh (ax->DHRs, DHRp, &dh);
1501 t_ax_hmac_hash (&ax->RK, &hmac, &dh, sizeof (dh));
1502 GNUNET_CRYPTO_kdf (keys, sizeof (keys), ctx, sizeof (ctx),
1503 &hmac, sizeof (hmac), NULL);
1505 /* Commit "purported" keys */
1511 ax->ratchet_allowed = GNUNET_YES;
1515 LOG (GNUNET_ERROR_TYPE_DEBUG, "current HK\n");
1516 t_h_decrypt (t, src, dstmsg);
1517 Np = ntohl (dstmsg->Ns);
1518 PNp = ntohl (dstmsg->PNs);
1522 store_ax_keys (t, &ax->HKr, Np);
1526 osize = t_ax_decrypt (t, dst, &src[1], esize);
1529 GNUNET_break_op (0);
1538 * Create key material by doing ECDH on the local and remote ephemeral keys.
1540 * @param key_material Where to store the key material.
1541 * @param ephemeral Peer's public ephemeral key.
1543 * @return GNUNET_OK if it went fine, GNUNET_SYSERR otherwise.
1546 derive_otr_key_material (struct GNUNET_HashCode *key_material,
1547 const struct GNUNET_CRYPTO_EcdhePublicKey *ephemeral)
1550 GNUNET_CRYPTO_ecc_ecdh (otr_ephemeral_key, ephemeral, key_material))
1553 return GNUNET_SYSERR;
1560 * Create a symmetic key from the identities of both ends and the key material
1563 * @param key Destination for the generated key.
1564 * @param sender ID of the peer that will encrypt with @c key.
1565 * @param receiver ID of the peer that will decrypt with @c key.
1566 * @param key_material Hash created with ECDH with the ephemeral keys.
1569 derive_symmertic (struct GNUNET_CRYPTO_SymmetricSessionKey *key,
1570 const struct GNUNET_PeerIdentity *sender,
1571 const struct GNUNET_PeerIdentity *receiver,
1572 const struct GNUNET_HashCode *key_material)
1574 const char salt[] = "CADET kx salt";
1576 GNUNET_CRYPTO_kdf (key, sizeof (struct GNUNET_CRYPTO_SymmetricSessionKey),
1577 salt, sizeof (salt),
1578 key_material, sizeof (struct GNUNET_HashCode),
1579 sender, sizeof (struct GNUNET_PeerIdentity),
1580 receiver, sizeof (struct GNUNET_PeerIdentity),
1586 * Derive the tunnel's keys using our own and the peer's ephemeral keys.
1588 * @param t Tunnel for which to create the keys.
1590 * @return GNUNET_OK if successful, GNUNET_SYSERR otherwise.
1593 create_otr_keys (struct CadetTunnel *t)
1595 struct GNUNET_HashCode km;
1597 if (GNUNET_OK != derive_otr_key_material (&km, &t->peers_ephemeral_key))
1598 return GNUNET_SYSERR;
1599 derive_symmertic (&t->e_key, &my_full_id, GCP_get_id (t->peer), &km);
1600 derive_symmertic (&t->d_key, GCP_get_id (t->peer), &my_full_id, &km);
1601 #if DUMP_KEYS_TO_STDERR
1602 LOG (GNUNET_ERROR_TYPE_INFO, "ME: %s\n",
1603 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &otr_kx_msg.ephemeral_key));
1604 LOG (GNUNET_ERROR_TYPE_INFO, "PE: %s\n",
1605 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &t->peers_ephemeral_key));
1606 LOG (GNUNET_ERROR_TYPE_INFO, "KM: %s\n", GNUNET_h2s (&km));
1607 LOG (GNUNET_ERROR_TYPE_INFO, "EK: %s\n",
1608 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &t->e_key));
1609 LOG (GNUNET_ERROR_TYPE_INFO, "DK: %s\n",
1610 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &t->d_key));
1617 * Create a new Key eXchange context for the tunnel.
1619 * If the old keys were verified, keep them for old traffic. Create a new KX
1620 * timestamp and a new nonce.
1622 * @param t Tunnel for which to create the KX ctx.
1624 * @return GNUNET_OK if successful, GNUNET_SYSERR otherwise.
1627 create_kx_ctx (struct CadetTunnel *t)
1629 LOG (GNUNET_ERROR_TYPE_INFO, " new kx ctx for %s\n", GCT_2s (t));
1631 if (NULL != t->kx_ctx)
1633 if (NULL != t->kx_ctx->finish_task)
1635 LOG (GNUNET_ERROR_TYPE_INFO, " resetting exisiting finish task\n");
1636 GNUNET_SCHEDULER_cancel (t->kx_ctx->finish_task);
1637 t->kx_ctx->finish_task = NULL;
1642 t->kx_ctx = GNUNET_new (struct CadetTunnelKXCtx);
1643 t->kx_ctx->challenge = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE,
1647 if (CADET_TUNNEL_KEY_OK == t->estate)
1649 LOG (GNUNET_ERROR_TYPE_INFO, " backing up keys\n");
1650 t->kx_ctx->d_key_old = t->d_key;
1651 t->kx_ctx->e_key_old = t->e_key;
1654 LOG (GNUNET_ERROR_TYPE_INFO, " old keys not valid, not saving\n");
1655 t->kx_ctx->rekey_start_time = GNUNET_TIME_absolute_get ();
1656 return create_otr_keys (t);
1661 * @brief Finish the Key eXchange and destroy the old keys.
1663 * @param cls Closure (Tunnel for which to finish the KX).
1664 * @param tc Task context.
1667 finish_kx (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
1669 struct CadetTunnel *t = cls;
1671 LOG (GNUNET_ERROR_TYPE_INFO, "finish KX for %s\n", GCT_2s (t));
1673 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
1675 LOG (GNUNET_ERROR_TYPE_INFO, " shutdown\n");
1679 GNUNET_free (t->kx_ctx);
1685 * Destroy a Key eXchange context for the tunnel. This function only schedules
1686 * the destruction, the freeing of the memory (and clearing of old key material)
1687 * happens after a delay!
1689 * @param t Tunnel whose KX ctx to destroy.
1692 destroy_kx_ctx (struct CadetTunnel *t)
1694 struct GNUNET_TIME_Relative delay;
1696 if (NULL == t->kx_ctx || NULL != t->kx_ctx->finish_task)
1699 if (is_key_null (&t->kx_ctx->e_key_old))
1701 t->kx_ctx->finish_task = GNUNET_SCHEDULER_add_now (finish_kx, t);
1705 delay = GNUNET_TIME_relative_divide (rekey_period, 4);
1706 delay = GNUNET_TIME_relative_min (delay, GNUNET_TIME_UNIT_MINUTES);
1708 t->kx_ctx->finish_task = GNUNET_SCHEDULER_add_delayed (delay, finish_kx, t);
1714 * Pick a connection on which send the next data message.
1716 * @param t Tunnel on which to send the message.
1718 * @return The connection on which to send the next message.
1720 static struct CadetConnection *
1721 tunnel_get_connection (struct CadetTunnel *t)
1723 struct CadetTConnection *iter;
1724 struct CadetConnection *best;
1726 unsigned int lowest_q;
1728 LOG (GNUNET_ERROR_TYPE_DEBUG, "tunnel_get_connection %s\n", GCT_2s (t));
1730 lowest_q = UINT_MAX;
1731 for (iter = t->connection_head; NULL != iter; iter = iter->next)
1733 LOG (GNUNET_ERROR_TYPE_DEBUG, " connection %s: %u\n",
1734 GCC_2s (iter->c), GCC_get_state (iter->c));
1735 if (CADET_CONNECTION_READY == GCC_get_state (iter->c))
1737 qn = GCC_get_qn (iter->c, GCC_is_origin (iter->c, GNUNET_YES));
1738 LOG (GNUNET_ERROR_TYPE_DEBUG, " q_n %u, \n", qn);
1746 LOG (GNUNET_ERROR_TYPE_DEBUG, " selected: connection %s\n", GCC_2s (best));
1752 * Callback called when a queued message is sent.
1754 * Calculates the average time and connection packet tracking.
1756 * @param cls Closure (TunnelQueue handle).
1757 * @param c Connection this message was on.
1758 * @param q Connection queue handle (unused).
1759 * @param type Type of message sent.
1760 * @param fwd Was this a FWD going message?
1761 * @param size Size of the message.
1764 tun_message_sent (void *cls,
1765 struct CadetConnection *c,
1766 struct CadetConnectionQueue *q,
1767 uint16_t type, int fwd, size_t size)
1769 struct CadetTunnelQueue *qt = cls;
1770 struct CadetTunnel *t;
1772 LOG (GNUNET_ERROR_TYPE_DEBUG, "tun_message_sent\n");
1774 GNUNET_assert (NULL != qt->cont);
1775 t = NULL == c ? NULL : GCC_get_tunnel (c);
1776 qt->cont (qt->cont_cls, t, qt, type, size);
1782 count_queued_data (const struct CadetTunnel *t)
1784 struct CadetTunnelDelayed *iter;
1787 for (count = 0, iter = t->tq_head; iter != NULL; iter = iter->next)
1794 * Delete a queued message: either was sent or the channel was destroyed
1795 * before the tunnel's key exchange had a chance to finish.
1797 * @param tqd Delayed queue handle.
1800 unqueue_data (struct CadetTunnelDelayed *tqd)
1802 GNUNET_CONTAINER_DLL_remove (tqd->t->tq_head, tqd->t->tq_tail, tqd);
1808 * Cache a message to be sent once tunnel is online.
1810 * @param t Tunnel to hold the message.
1811 * @param msg Message itself (copy will be made).
1813 static struct CadetTunnelDelayed *
1814 queue_data (struct CadetTunnel *t, const struct GNUNET_MessageHeader *msg)
1816 struct CadetTunnelDelayed *tqd;
1817 uint16_t size = ntohs (msg->size);
1819 LOG (GNUNET_ERROR_TYPE_DEBUG, "queue data on Tunnel %s\n", GCT_2s (t));
1821 GNUNET_assert (GNUNET_NO == is_ready (t));
1823 tqd = GNUNET_malloc (sizeof (struct CadetTunnelDelayed) + size);
1826 memcpy (&tqd[1], msg, size);
1827 GNUNET_CONTAINER_DLL_insert_tail (t->tq_head, t->tq_tail, tqd);
1833 * Sends an already built message on a tunnel, encrypting it and
1834 * choosing the best connection.
1836 * @param message Message to send. Function modifies it.
1837 * @param t Tunnel on which this message is transmitted.
1838 * @param c Connection to use (autoselect if NULL).
1839 * @param force Force the tunnel to take the message (buffer overfill).
1840 * @param cont Continuation to call once message is really sent.
1841 * @param cont_cls Closure for @c cont.
1842 * @param existing_q In case this a transmission of previously queued data,
1843 * this should be TunnelQueue given to the client.
1846 * @return Handle to cancel message.
1847 * NULL if @c cont is NULL or an error happens and message is dropped.
1849 static struct CadetTunnelQueue *
1850 send_prebuilt_message (const struct GNUNET_MessageHeader *message,
1851 struct CadetTunnel *t, struct CadetConnection *c,
1852 int force, GCT_sent cont, void *cont_cls,
1853 struct CadetTunnelQueue *existing_q)
1855 struct GNUNET_MessageHeader *msg;
1856 struct GNUNET_CADET_Encrypted *otr_msg;
1857 struct GNUNET_CADET_AX *ax_msg;
1858 struct CadetTunnelQueue *tq;
1859 size_t size = ntohs (message->size);
1860 const uint16_t max_overhead = sizeof (struct GNUNET_CADET_Encrypted)
1861 + sizeof (struct GNUNET_CADET_AX);
1862 char cbuf[max_overhead + size];
1869 LOG (GNUNET_ERROR_TYPE_DEBUG, "GMT Send on Tunnel %s\n", GCT_2s (t));
1871 if (GNUNET_NO == is_ready (t))
1873 struct CadetTunnelDelayed *tqd;
1874 /* A non null existing_q indicates sending of queued data.
1875 * Should only happen after tunnel becomes ready.
1877 GNUNET_assert (NULL == existing_q);
1878 tqd = queue_data (t, message);
1881 tq = GNUNET_new (struct CadetTunnelQueue);
1885 tq->cont_cls = cont_cls;
1889 GNUNET_assert (GNUNET_NO == GCT_is_loopback (t));
1891 if (CADET_Axolotl == t->enc_type)
1893 ax_msg = (struct GNUNET_CADET_AX *) cbuf;
1894 msg = &ax_msg->header;
1895 msg->size = htons (sizeof (struct GNUNET_CADET_AX) + size);
1896 msg->type = htons (GNUNET_MESSAGE_TYPE_CADET_AX);
1897 ax_msg->reserved = 0;
1898 esize = t_ax_encrypt (t, &ax_msg[1], message, size);
1899 ax_msg->Ns = htonl (t->ax->Ns++);
1900 ax_msg->PNs = htonl (t->ax->PNs);
1901 GNUNET_CRYPTO_ecdhe_key_get_public (t->ax->DHRs, &ax_msg->DHRs);
1902 t_h_encrypt (t, ax_msg);
1903 t_hmac (&ax_msg->Ns, AX_HEADER_SIZE + esize, 0, &t->ax->HKs, &ax_msg->hmac);
1907 otr_msg = (struct GNUNET_CADET_Encrypted *) cbuf;
1908 msg = &otr_msg->header;
1909 iv = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX);
1911 esize = t_encrypt (t, &otr_msg[1], message, size, iv, GNUNET_NO);
1912 t_hmac (&otr_msg[1], size, iv, select_key (t), &otr_msg->hmac);
1913 msg->size = htons (sizeof (struct GNUNET_CADET_Encrypted) + size);
1914 msg->type = htons (GNUNET_MESSAGE_TYPE_CADET_ENCRYPTED);
1915 otr_msg->ttl = htonl (default_ttl);
1917 GNUNET_assert (esize == size);
1920 c = tunnel_get_connection (t);
1923 /* Why is tunnel 'ready'? Should have been queued! */
1924 if (NULL != t->destroy_task)
1927 GCT_debug (t, GNUNET_ERROR_TYPE_WARNING);
1929 return NULL; /* Drop... */
1933 type = ntohs (message->type);
1936 case GNUNET_MESSAGE_TYPE_CADET_DATA:
1937 case GNUNET_MESSAGE_TYPE_CADET_DATA_ACK:
1938 if (GNUNET_MESSAGE_TYPE_CADET_DATA == type)
1939 mid = ntohl (((struct GNUNET_CADET_Data *) message)->mid);
1941 mid = ntohl (((struct GNUNET_CADET_DataACK *) message)->mid);
1943 case GNUNET_MESSAGE_TYPE_CADET_KEEPALIVE:
1944 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_CREATE:
1945 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_DESTROY:
1946 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_ACK:
1947 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_NACK:
1951 LOG (GNUNET_ERROR_TYPE_ERROR, "type %s not valid\n", GC_m2s (type));
1953 LOG (GNUNET_ERROR_TYPE_DEBUG, "type %s\n", GC_m2s (type));
1955 fwd = GCC_is_origin (c, GNUNET_YES);
1959 GNUNET_break (NULL == GCC_send_prebuilt_message (msg, type,
1960 mid, c, fwd, force, NULL, NULL));
1963 if (NULL == existing_q)
1965 tq = GNUNET_new (struct CadetTunnelQueue); /* FIXME valgrind: leak*/
1972 tq->cq = GCC_send_prebuilt_message (msg, type, mid, c, fwd, force,
1973 &tun_message_sent, tq);
1974 GNUNET_assert (NULL != tq->cq);
1976 tq->cont_cls = cont_cls;
1983 * Send all cached messages that we can, tunnel is online.
1985 * @param t Tunnel that holds the messages. Cannot be loopback.
1988 send_queued_data (struct CadetTunnel *t)
1990 struct CadetTunnelDelayed *tqd;
1991 struct CadetTunnelDelayed *next;
1994 LOG (GNUNET_ERROR_TYPE_INFO, "Send queued data, tunnel %s\n", GCT_2s (t));
1996 if (GCT_is_loopback (t))
2002 if (GNUNET_NO == is_ready (t))
2004 LOG (GNUNET_ERROR_TYPE_DEBUG, " not ready yet: %s/%s\n",
2005 estate2s (t->estate), cstate2s (t->cstate));
2009 room = GCT_get_connections_buffer (t);
2010 LOG (GNUNET_ERROR_TYPE_DEBUG, " buffer space: %u\n", room);
2011 LOG (GNUNET_ERROR_TYPE_DEBUG, " tq head: %p\n", t->tq_head);
2012 for (tqd = t->tq_head; NULL != tqd && room > 0; tqd = next)
2014 LOG (GNUNET_ERROR_TYPE_DEBUG, " sending queued data\n");
2017 send_prebuilt_message ((struct GNUNET_MessageHeader *) &tqd[1],
2018 tqd->t, NULL, GNUNET_YES,
2019 NULL != tqd->tq ? tqd->tq->cont : NULL,
2020 NULL != tqd->tq ? tqd->tq->cont_cls : NULL,
2024 LOG (GNUNET_ERROR_TYPE_DEBUG, "GCT_send_queued_data end\n", GCP_2s (t->peer));
2029 * @brief Resend the AX KX until we complete the handshake.
2031 * @param cls Closure (tunnel).
2032 * @param tc Task context.
2035 ax_kx_resend (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
2037 struct CadetTunnel *t = cls;
2039 t->rekey_task = NULL;
2041 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
2044 if (CADET_TUNNEL_KEY_OK == t->estate)
2046 /* Should have been canceled on estate change */
2051 GCT_send_ax_kx (t, GNUNET_YES);
2056 * Callback called when a queued message is sent.
2058 * @param cls Closure.
2059 * @param c Connection this message was on.
2060 * @param type Type of message sent.
2061 * @param fwd Was this a FWD going message?
2062 * @param size Size of the message.
2065 ephm_sent (void *cls,
2066 struct CadetConnection *c,
2067 struct CadetConnectionQueue *q,
2068 uint16_t type, int fwd, size_t size)
2070 struct CadetTunnel *t = cls;
2071 LOG (GNUNET_ERROR_TYPE_DEBUG, "ephemeral sent %s\n", GC_m2s (type));
2075 if (CADET_TUNNEL_KEY_OK == t->estate)
2078 if (CADET_Axolotl == t->enc_type)
2080 if (NULL != t->rekey_task)
2083 GNUNET_SCHEDULER_cancel (t->rekey_task);
2085 t->rekey_task = GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_SECONDS,
2092 * Callback called when a queued message is sent.
2094 * @param cls Closure.
2095 * @param c Connection this message was on.
2096 * @param type Type of message sent.
2097 * @param fwd Was this a FWD going message?
2098 * @param size Size of the message.
2101 pong_sent (void *cls,
2102 struct CadetConnection *c,
2103 struct CadetConnectionQueue *q,
2104 uint16_t type, int fwd, size_t size)
2106 struct CadetTunnel *t = cls;
2107 LOG (GNUNET_ERROR_TYPE_DEBUG, "pong_sent %s\n", GC_m2s (type));
2114 * Sends key exchange message on a tunnel, choosing the best connection.
2115 * Should not be called on loopback tunnels.
2117 * @param t Tunnel on which this message is transmitted.
2118 * @param message Message to send. Function modifies it.
2120 * @return Handle to the message in the connection queue.
2122 static struct CadetConnectionQueue *
2123 send_kx (struct CadetTunnel *t,
2124 const struct GNUNET_MessageHeader *message)
2126 struct CadetConnection *c;
2127 struct GNUNET_CADET_KX *msg;
2128 size_t size = ntohs (message->size);
2129 char cbuf[sizeof (struct GNUNET_CADET_KX) + size];
2134 LOG (GNUNET_ERROR_TYPE_DEBUG, "GMT KX on Tunnel %s\n", GCT_2s (t));
2136 /* Avoid loopback. */
2137 if (GCT_is_loopback (t))
2142 type = ntohs (message->type);
2144 /* Even if tunnel is "being destroyed", send anyway.
2145 * Could be a response to a rekey initiated by remote peer,
2146 * who is trying to create a new channel!
2149 /* Must have a connection, or be looking for one. */
2150 if (NULL == t->connection_head)
2152 LOG (GNUNET_ERROR_TYPE_DEBUG, "%s with no connection\n", GC_m2s (type));
2153 if (CADET_TUNNEL_SEARCHING != t->cstate)
2156 GCT_debug (t, GNUNET_ERROR_TYPE_ERROR);
2157 GCP_debug (t->peer, GNUNET_ERROR_TYPE_ERROR);
2162 msg = (struct GNUNET_CADET_KX *) cbuf;
2163 msg->header.type = htons (GNUNET_MESSAGE_TYPE_CADET_KX);
2164 msg->header.size = htons (sizeof (struct GNUNET_CADET_KX) + size);
2165 c = tunnel_get_connection (t);
2168 if (NULL == t->destroy_task && CADET_TUNNEL_READY == t->cstate)
2171 GCT_debug (t, GNUNET_ERROR_TYPE_ERROR);
2177 case GNUNET_MESSAGE_TYPE_CADET_KX_EPHEMERAL:
2178 case GNUNET_MESSAGE_TYPE_CADET_AX_KX:
2179 GNUNET_assert (NULL == t->ephm_h);
2182 case GNUNET_MESSAGE_TYPE_CADET_KX_PONG:
2183 GNUNET_assert (NULL == t->pong_h);
2188 LOG (GNUNET_ERROR_TYPE_DEBUG, "unkown type %s\n", GC_m2s (type));
2191 memcpy (&msg[1], message, size);
2193 fwd = GCC_is_origin (c, GNUNET_YES);
2195 return GCC_send_prebuilt_message (&msg->header, type, 0, c,
2202 * Send the ephemeral key on a tunnel.
2204 * @param t Tunnel on which to send the key.
2207 send_ephemeral (struct CadetTunnel *t)
2209 LOG (GNUNET_ERROR_TYPE_INFO, "===> EPHM for %s\n", GCT_2s (t));
2210 if (NULL != t->ephm_h)
2212 LOG (GNUNET_ERROR_TYPE_INFO, " already queued\n");
2216 otr_kx_msg.sender_status = htonl (t->estate);
2217 otr_kx_msg.iv = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX);
2218 otr_kx_msg.nonce = t->kx_ctx->challenge;
2219 LOG (GNUNET_ERROR_TYPE_DEBUG, " send nonce c %u\n", otr_kx_msg.nonce);
2220 t_encrypt (t, &otr_kx_msg.nonce, &otr_kx_msg.nonce,
2221 ping_encryption_size(), otr_kx_msg.iv, GNUNET_YES);
2222 LOG (GNUNET_ERROR_TYPE_DEBUG, " send nonce e %u\n", otr_kx_msg.nonce);
2223 t->ephm_h = send_kx (t, &otr_kx_msg.header);
2228 * Send a pong message on a tunnel.
2230 * @param t Tunnel on which to send the pong.
2231 * @param challenge Value sent in the ping that we have to send back.
2234 send_pong (struct CadetTunnel *t, uint32_t challenge)
2236 struct GNUNET_CADET_KX_Pong msg;
2238 LOG (GNUNET_ERROR_TYPE_INFO, "===> PONG for %s\n", GCT_2s (t));
2239 if (NULL != t->pong_h)
2241 LOG (GNUNET_ERROR_TYPE_INFO, " already queued\n");
2244 msg.header.size = htons (sizeof (msg));
2245 msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_KX_PONG);
2246 msg.iv = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX);
2247 msg.nonce = challenge;
2248 LOG (GNUNET_ERROR_TYPE_DEBUG, " sending %u\n", msg.nonce);
2249 t_encrypt (t, &msg.nonce, &msg.nonce,
2250 sizeof (msg.nonce), msg.iv, GNUNET_YES);
2251 LOG (GNUNET_ERROR_TYPE_DEBUG, " e sending %u\n", msg.nonce);
2253 t->pong_h = send_kx (t, &msg.header);
2258 * Initiate a rekey with the remote peer.
2260 * @param cls Closure (tunnel).
2261 * @param tc TaskContext.
2264 rekey_tunnel (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
2266 struct CadetTunnel *t = cls;
2268 t->rekey_task = NULL;
2270 LOG (GNUNET_ERROR_TYPE_INFO, "Re-key Tunnel %s\n", GCT_2s (t));
2271 if (NULL != tc && 0 != (GNUNET_SCHEDULER_REASON_SHUTDOWN & tc->reason))
2274 GNUNET_assert (NULL != t->kx_ctx);
2275 struct GNUNET_TIME_Relative duration;
2277 duration = GNUNET_TIME_absolute_get_duration (t->kx_ctx->rekey_start_time);
2278 LOG (GNUNET_ERROR_TYPE_DEBUG, " kx started %s ago\n",
2279 GNUNET_STRINGS_relative_time_to_string (duration, GNUNET_YES));
2281 // FIXME make duration of old keys configurable
2282 if (duration.rel_value_us >= GNUNET_TIME_UNIT_MINUTES.rel_value_us)
2284 LOG (GNUNET_ERROR_TYPE_DEBUG, " deleting old keys\n");
2285 memset (&t->kx_ctx->d_key_old, 0, sizeof (t->kx_ctx->d_key_old));
2286 memset (&t->kx_ctx->e_key_old, 0, sizeof (t->kx_ctx->e_key_old));
2293 case CADET_TUNNEL_KEY_UNINITIALIZED:
2294 GCT_change_estate (t, CADET_TUNNEL_KEY_SENT);
2297 case CADET_TUNNEL_KEY_SENT:
2300 case CADET_TUNNEL_KEY_OK:
2302 * - state should have changed during rekey_iterator
2303 * - task should have been canceled at pong_handle
2306 GCT_change_estate (t, CADET_TUNNEL_KEY_REKEY);
2309 case CADET_TUNNEL_KEY_PING:
2310 case CADET_TUNNEL_KEY_REKEY:
2314 LOG (GNUNET_ERROR_TYPE_DEBUG, "Unexpected state %u\n", t->estate);
2317 // FIXME exponential backoff
2318 struct GNUNET_TIME_Relative delay;
2320 delay = GNUNET_TIME_relative_divide (rekey_period, 16);
2321 delay = GNUNET_TIME_relative_min (delay, REKEY_WAIT);
2322 LOG (GNUNET_ERROR_TYPE_DEBUG, " next call in %s\n",
2323 GNUNET_STRINGS_relative_time_to_string (delay, GNUNET_YES));
2324 t->rekey_task = GNUNET_SCHEDULER_add_delayed (delay, &rekey_tunnel, t);
2329 * Our ephemeral key has changed, create new session key on all tunnels.
2331 * Each tunnel will start the Key Exchange with a random delay between
2332 * 0 and number_of_tunnels*100 milliseconds, so there are 10 key exchanges
2333 * per second, on average.
2335 * @param cls Closure (size of the hashmap).
2336 * @param key Current public key.
2337 * @param value Value in the hash map (tunnel).
2339 * @return #GNUNET_YES, so we should continue to iterate,
2342 rekey_iterator (void *cls,
2343 const struct GNUNET_PeerIdentity *key,
2346 struct CadetTunnel *t = value;
2347 struct GNUNET_TIME_Relative delay;
2348 long n = (long) cls;
2351 if (NULL != t->rekey_task)
2354 if (GNUNET_YES == GCT_is_loopback (t))
2357 if (CADET_OTR != t->enc_type)
2360 r = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK, (uint32_t) n * 100);
2361 delay = GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MILLISECONDS, r);
2362 t->rekey_task = GNUNET_SCHEDULER_add_delayed (delay, &rekey_tunnel, t);
2363 if (GNUNET_OK == create_kx_ctx (t))
2364 GCT_change_estate (t, CADET_TUNNEL_KEY_REKEY);
2376 * Create a new ephemeral key and key message, schedule next rekeying.
2378 * @param cls Closure (unused).
2379 * @param tc TaskContext.
2382 global_otr_rekey (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
2384 struct GNUNET_TIME_Absolute time;
2389 if (0 != (GNUNET_SCHEDULER_REASON_SHUTDOWN & tc->reason))
2392 GNUNET_free_non_null (otr_ephemeral_key);
2393 otr_ephemeral_key = GNUNET_CRYPTO_ecdhe_key_create ();
2395 time = GNUNET_TIME_absolute_get ();
2396 otr_kx_msg.creation_time = GNUNET_TIME_absolute_hton (time);
2397 time = GNUNET_TIME_absolute_add (time, rekey_period);
2398 time = GNUNET_TIME_absolute_add (time, GNUNET_TIME_UNIT_MINUTES);
2399 otr_kx_msg.expiration_time = GNUNET_TIME_absolute_hton (time);
2400 GNUNET_CRYPTO_ecdhe_key_get_public (otr_ephemeral_key, &otr_kx_msg.ephemeral_key);
2401 LOG (GNUNET_ERROR_TYPE_INFO, "GLOBAL OTR RE-KEY, NEW EPHM: %s\n",
2402 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &otr_kx_msg.ephemeral_key));
2404 GNUNET_assert (GNUNET_OK ==
2405 GNUNET_CRYPTO_eddsa_sign (id_key,
2406 &otr_kx_msg.purpose,
2407 &otr_kx_msg.signature));
2409 n = (long) GNUNET_CONTAINER_multipeermap_size (tunnels);
2410 GNUNET_CONTAINER_multipeermap_iterate (tunnels, &rekey_iterator, (void *) n);
2412 rekey_task = GNUNET_SCHEDULER_add_delayed (rekey_period,
2413 &global_otr_rekey, NULL);
2418 * Called only on shutdown, destroy every tunnel.
2420 * @param cls Closure (unused).
2421 * @param key Current public key.
2422 * @param value Value in the hash map (tunnel).
2424 * @return #GNUNET_YES, so we should continue to iterate,
2427 destroy_iterator (void *cls,
2428 const struct GNUNET_PeerIdentity *key,
2431 struct CadetTunnel *t = value;
2433 LOG (GNUNET_ERROR_TYPE_DEBUG, "GCT_shutdown destroying tunnel at %p\n", t);
2440 * Notify remote peer that we don't know a channel he is talking about,
2441 * probably CHANNEL_DESTROY was missed.
2443 * @param t Tunnel on which to notify.
2444 * @param gid ID of the channel.
2447 send_channel_destroy (struct CadetTunnel *t, unsigned int gid)
2449 struct GNUNET_CADET_ChannelManage msg;
2451 msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_CHANNEL_DESTROY);
2452 msg.header.size = htons (sizeof (msg));
2453 msg.chid = htonl (gid);
2455 LOG (GNUNET_ERROR_TYPE_DEBUG,
2456 "WARNING destroying unknown channel %u on tunnel %s\n",
2458 send_prebuilt_message (&msg.header, t, NULL, GNUNET_YES, NULL, NULL, NULL);
2463 * Demultiplex data per channel and call appropriate channel handler.
2465 * @param t Tunnel on which the data came.
2466 * @param msg Data message.
2467 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
2468 * #GNUNET_YES if message is FWD on the respective channel (loopback)
2469 * #GNUNET_NO if message is BCK on the respective channel (loopback)
2470 * #GNUNET_SYSERR if message on a one-ended channel (remote)
2473 handle_data (struct CadetTunnel *t,
2474 const struct GNUNET_CADET_Data *msg,
2477 struct CadetChannel *ch;
2481 size = ntohs (msg->header.size);
2483 sizeof (struct GNUNET_CADET_Data) +
2484 sizeof (struct GNUNET_MessageHeader))
2489 LOG (GNUNET_ERROR_TYPE_DEBUG, " payload of type %s\n",
2490 GC_m2s (ntohs (msg[1].header.type)));
2493 ch = GCT_get_channel (t, ntohl (msg->chid));
2496 GNUNET_STATISTICS_update (stats, "# data on unknown channel",
2498 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel 0x%X unknown\n",
2500 send_channel_destroy (t, ntohl (msg->chid));
2504 GCCH_handle_data (ch, msg, fwd);
2509 * Demultiplex data ACKs per channel and update appropriate channel buffer info.
2511 * @param t Tunnel on which the DATA ACK came.
2512 * @param msg DATA ACK message.
2513 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
2514 * #GNUNET_YES if message is FWD on the respective channel (loopback)
2515 * #GNUNET_NO if message is BCK on the respective channel (loopback)
2516 * #GNUNET_SYSERR if message on a one-ended channel (remote)
2519 handle_data_ack (struct CadetTunnel *t,
2520 const struct GNUNET_CADET_DataACK *msg,
2523 struct CadetChannel *ch;
2527 size = ntohs (msg->header.size);
2528 if (size != sizeof (struct GNUNET_CADET_DataACK))
2535 ch = GCT_get_channel (t, ntohl (msg->chid));
2538 GNUNET_STATISTICS_update (stats, "# data ack on unknown channel",
2540 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel %u unknown\n",
2545 GCCH_handle_data_ack (ch, msg, fwd);
2550 * Handle channel create.
2552 * @param t Tunnel on which the data came.
2553 * @param msg Data message.
2556 handle_ch_create (struct CadetTunnel *t,
2557 const struct GNUNET_CADET_ChannelCreate *msg)
2559 struct CadetChannel *ch;
2563 size = ntohs (msg->header.size);
2564 if (size != sizeof (struct GNUNET_CADET_ChannelCreate))
2571 ch = GCT_get_channel (t, ntohl (msg->chid));
2572 if (NULL != ch && ! GCT_is_loopback (t))
2574 /* Probably a retransmission, safe to ignore */
2575 LOG (GNUNET_ERROR_TYPE_DEBUG, " already exists...\n");
2577 ch = GCCH_handle_create (t, msg);
2579 GCT_add_channel (t, ch);
2585 * Handle channel NACK: check correctness and call channel handler for NACKs.
2587 * @param t Tunnel on which the NACK came.
2588 * @param msg NACK message.
2591 handle_ch_nack (struct CadetTunnel *t,
2592 const struct GNUNET_CADET_ChannelManage *msg)
2594 struct CadetChannel *ch;
2598 size = ntohs (msg->header.size);
2599 if (size != sizeof (struct GNUNET_CADET_ChannelManage))
2606 ch = GCT_get_channel (t, ntohl (msg->chid));
2609 GNUNET_STATISTICS_update (stats, "# channel NACK on unknown channel",
2611 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel %u unknown\n",
2616 GCCH_handle_nack (ch);
2621 * Handle a CHANNEL ACK (SYNACK/ACK).
2623 * @param t Tunnel on which the CHANNEL ACK came.
2624 * @param msg CHANNEL ACK message.
2625 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
2626 * #GNUNET_YES if message is FWD on the respective channel (loopback)
2627 * #GNUNET_NO if message is BCK on the respective channel (loopback)
2628 * #GNUNET_SYSERR if message on a one-ended channel (remote)
2631 handle_ch_ack (struct CadetTunnel *t,
2632 const struct GNUNET_CADET_ChannelManage *msg,
2635 struct CadetChannel *ch;
2639 size = ntohs (msg->header.size);
2640 if (size != sizeof (struct GNUNET_CADET_ChannelManage))
2647 ch = GCT_get_channel (t, ntohl (msg->chid));
2650 GNUNET_STATISTICS_update (stats, "# channel ack on unknown channel",
2652 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel %u unknown\n",
2657 GCCH_handle_ack (ch, msg, fwd);
2662 * Handle a channel destruction message.
2664 * @param t Tunnel on which the message came.
2665 * @param msg Channel destroy message.
2666 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
2667 * #GNUNET_YES if message is FWD on the respective channel (loopback)
2668 * #GNUNET_NO if message is BCK on the respective channel (loopback)
2669 * #GNUNET_SYSERR if message on a one-ended channel (remote)
2672 handle_ch_destroy (struct CadetTunnel *t,
2673 const struct GNUNET_CADET_ChannelManage *msg,
2676 struct CadetChannel *ch;
2680 size = ntohs (msg->header.size);
2681 if (size != sizeof (struct GNUNET_CADET_ChannelManage))
2688 ch = GCT_get_channel (t, ntohl (msg->chid));
2691 /* Probably a retransmission, safe to ignore */
2695 GCCH_handle_destroy (ch, msg, fwd);
2700 * Free Axolotl data.
2705 destroy_ax (struct CadetTunnel *t)
2710 GNUNET_free_non_null (t->ax->DHRs);
2711 GNUNET_free_non_null (t->ax->kx_0);
2712 while (NULL != t->ax->skipped_head)
2713 delete_skipped_key (t, t->ax->skipped_head);
2714 GNUNET_assert (0 == t->ax->skipped);
2716 GNUNET_free (t->ax);
2719 if (NULL != t->rekey_task)
2721 GNUNET_SCHEDULER_cancel (t->rekey_task);
2722 t->rekey_task = NULL;
2724 if (NULL != t->ephm_h)
2726 GCC_cancel (t->ephm_h);
2733 * The peer's ephemeral key has changed: update the symmetrical keys.
2735 * @param t Tunnel this message came on.
2736 * @param msg Key eXchange message.
2739 handle_ephemeral (struct CadetTunnel *t,
2740 const struct GNUNET_CADET_KX_Ephemeral *msg)
2742 LOG (GNUNET_ERROR_TYPE_INFO, "<=== EPHM for %s\n", GCT_2s (t));
2744 /* Some old versions are still around, don't log as error. */
2745 if (GNUNET_OK != check_ephemeral (t, msg))
2748 /* If we get a proper OTR-style ephemeral, fallback to old crypto. */
2752 t->enc_type = CADET_OTR;
2753 if (NULL != t->rekey_task)
2754 GNUNET_SCHEDULER_cancel (t->rekey_task);
2755 if (GNUNET_OK != create_kx_ctx (t))
2761 rekey_tunnel (t, NULL);
2762 GNUNET_STATISTICS_update (stats, "# otr-downgrades", -1, GNUNET_NO);
2766 * If the key is different from what we know, derive the new E/D keys.
2767 * Else destroy the rekey ctx (duplicate EPHM after successful KX).
2769 if (0 != memcmp (&t->peers_ephemeral_key, &msg->ephemeral_key,
2770 sizeof (msg->ephemeral_key)))
2772 #if DUMP_KEYS_TO_STDERR
2773 LOG (GNUNET_ERROR_TYPE_INFO, "OLD: %s\n",
2774 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &t->peers_ephemeral_key));
2775 LOG (GNUNET_ERROR_TYPE_INFO, "NEW: %s\n",
2776 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &msg->ephemeral_key));
2778 t->peers_ephemeral_key = msg->ephemeral_key;
2780 if (GNUNET_OK != create_kx_ctx (t))
2787 if (CADET_TUNNEL_KEY_OK == t->estate)
2789 GCT_change_estate (t, CADET_TUNNEL_KEY_REKEY);
2791 if (NULL != t->rekey_task)
2792 GNUNET_SCHEDULER_cancel (t->rekey_task);
2793 t->rekey_task = GNUNET_SCHEDULER_add_now (rekey_tunnel, t);
2795 if (CADET_TUNNEL_KEY_SENT == t->estate)
2797 LOG (GNUNET_ERROR_TYPE_DEBUG, " our key was sent, sending challenge\n");
2799 GCT_change_estate (t, CADET_TUNNEL_KEY_PING);
2802 if (CADET_TUNNEL_KEY_UNINITIALIZED != ntohl(msg->sender_status))
2806 LOG (GNUNET_ERROR_TYPE_DEBUG, " recv nonce e %u\n", msg->nonce);
2807 t_decrypt (t, &nonce, &msg->nonce, ping_encryption_size (), msg->iv);
2808 LOG (GNUNET_ERROR_TYPE_DEBUG, " recv nonce c %u\n", nonce);
2809 send_pong (t, nonce);
2815 * Peer has answer to our challenge.
2816 * If answer is successful, consider the key exchange finished and clean
2817 * up all related state.
2819 * @param t Tunnel this message came on.
2820 * @param msg Key eXchange Pong message.
2823 handle_pong (struct CadetTunnel *t,
2824 const struct GNUNET_CADET_KX_Pong *msg)
2828 LOG (GNUNET_ERROR_TYPE_INFO, "<=== PONG for %s\n", GCT_2s (t));
2829 if (NULL == t->rekey_task)
2831 GNUNET_STATISTICS_update (stats, "# duplicate PONG messages", 1, GNUNET_NO);
2834 if (NULL == t->kx_ctx)
2836 GNUNET_STATISTICS_update (stats, "# stray PONG messages", 1, GNUNET_NO);
2840 t_decrypt (t, &challenge, &msg->nonce, sizeof (uint32_t), msg->iv);
2841 if (challenge != t->kx_ctx->challenge)
2843 LOG (GNUNET_ERROR_TYPE_WARNING, "Wrong PONG challenge on %s\n", GCT_2s (t));
2844 LOG (GNUNET_ERROR_TYPE_DEBUG, "PONG: %u (e: %u). Expected: %u.\n",
2845 challenge, msg->nonce, t->kx_ctx->challenge);
2849 GNUNET_SCHEDULER_cancel (t->rekey_task);
2850 t->rekey_task = NULL;
2852 /* Don't free the old keys right away, but after a delay.
2853 * Rationale: the KX could have happened over a very fast connection,
2854 * with payload traffic still signed with the old key stuck in a slower
2856 * Don't keep the keys longer than 1/4 the rekey period, and no longer than
2860 GCT_change_estate (t, CADET_TUNNEL_KEY_OK);
2865 * Handle Axolotl handshake.
2867 * @param t Tunnel this message came on.
2868 * @param msg Key eXchange Pong message.
2871 handle_kx_ax (struct CadetTunnel *t, const struct GNUNET_CADET_AX_KX *msg)
2873 struct CadetTunnelAxolotl *ax;
2874 struct GNUNET_HashCode key_material[3];
2875 struct GNUNET_CRYPTO_SymmetricSessionKey keys[5];
2876 const char salt[] = "CADET Axolotl salt";
2877 const struct GNUNET_PeerIdentity *pid;
2880 LOG (GNUNET_ERROR_TYPE_INFO, "<=== AX_KX on %s\n", GCT_2s (t));
2884 /* Something is wrong if ax is NULL. Whose fault it is? */
2885 GNUNET_break_op (CADET_OTR == t->enc_type);
2886 GNUNET_break (CADET_Axolotl == t->enc_type);
2890 pid = GCT_get_destination (t);
2891 if (0 > GNUNET_CRYPTO_cmp_peer_identity (&my_full_id, pid))
2892 am_I_alice = GNUNET_YES;
2893 else if (0 < GNUNET_CRYPTO_cmp_peer_identity (&my_full_id, pid))
2894 am_I_alice = GNUNET_NO;
2897 GNUNET_break_op (0);
2901 if (GNUNET_CADET_AX_KX_FLAG_FORCE_REPLY ==
2902 (GNUNET_CADET_AX_KX_FLAG_FORCE_REPLY & ntohl (msg->flags)))
2903 GCT_send_ax_kx (t, GNUNET_NO);
2905 if (CADET_TUNNEL_KEY_OK == t->estate)
2908 LOG (GNUNET_ERROR_TYPE_INFO, " is Alice? %s\n", am_I_alice ? "YES" : "NO");
2911 ax->DHRr = msg->ratchet_key;
2914 if (GNUNET_YES == am_I_alice)
2916 GNUNET_CRYPTO_eddsa_ecdh (id_key, /* A */
2917 &msg->ephemeral_key, /* B0 */
2922 GNUNET_CRYPTO_ecdh_eddsa (ax->kx_0, /* B0 */
2923 &pid->public_key, /* A */
2928 if (GNUNET_YES == am_I_alice)
2930 GNUNET_CRYPTO_ecdh_eddsa (ax->kx_0, /* A0 */
2931 &pid->public_key, /* B */
2936 GNUNET_CRYPTO_eddsa_ecdh (id_key, /* A */
2937 &msg->ephemeral_key, /* B0 */
2944 /* (This is the triple-DH, we could probably safely skip this,
2945 as A0/B0 are already in the key material.) */
2946 GNUNET_CRYPTO_ecc_ecdh (ax->kx_0, /* A0 or B0 */
2947 &msg->ephemeral_key, /* B0 or A0 */
2950 #if DUMP_KEYS_TO_STDERR
2953 for (i = 0; i < 3; i++)
2954 LOG (GNUNET_ERROR_TYPE_INFO, "km[%u]: %s\n",
2955 i, GNUNET_h2s (&key_material[i]));
2960 GNUNET_CRYPTO_kdf (keys, sizeof (keys),
2961 salt, sizeof (salt),
2962 &key_material, sizeof (key_material), NULL);
2965 if (GNUNET_YES == am_I_alice)
2971 ax->ratchet_flag = GNUNET_YES;
2979 ax->ratchet_flag = GNUNET_NO;
2980 ax->ratchet_allowed = GNUNET_NO;
2981 ax->ratchet_counter = 0;
2982 ax->ratchet_expiration =
2983 GNUNET_TIME_absolute_add (GNUNET_TIME_absolute_get(), ratchet_time);
2985 GCT_change_estate (t, CADET_TUNNEL_KEY_PING);
2986 send_queued_data (t);
2991 * Demultiplex by message type and call appropriate handler for a message
2992 * towards a channel of a local tunnel.
2994 * @param t Tunnel this message came on.
2995 * @param msgh Message header.
2996 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
2997 * #GNUNET_YES if message is FWD on the respective channel (loopback)
2998 * #GNUNET_NO if message is BCK on the respective channel (loopback)
2999 * #GNUNET_SYSERR if message on a one-ended channel (remote)
3002 handle_decrypted (struct CadetTunnel *t,
3003 const struct GNUNET_MessageHeader *msgh,
3008 type = ntohs (msgh->type);
3009 LOG (GNUNET_ERROR_TYPE_INFO, "<=== %s on %s\n", GC_m2s (type), GCT_2s (t));
3013 case GNUNET_MESSAGE_TYPE_CADET_KEEPALIVE:
3014 /* Do nothing, connection aleady got updated. */
3015 GNUNET_STATISTICS_update (stats, "# keepalives received", 1, GNUNET_NO);
3018 case GNUNET_MESSAGE_TYPE_CADET_DATA:
3019 /* Don't send hop ACK, wait for client to ACK */
3020 handle_data (t, (struct GNUNET_CADET_Data *) msgh, fwd);
3023 case GNUNET_MESSAGE_TYPE_CADET_DATA_ACK:
3024 handle_data_ack (t, (struct GNUNET_CADET_DataACK *) msgh, fwd);
3027 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_CREATE:
3028 handle_ch_create (t, (struct GNUNET_CADET_ChannelCreate *) msgh);
3031 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_NACK:
3032 handle_ch_nack (t, (struct GNUNET_CADET_ChannelManage *) msgh);
3035 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_ACK:
3036 handle_ch_ack (t, (struct GNUNET_CADET_ChannelManage *) msgh, fwd);
3039 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_DESTROY:
3040 handle_ch_destroy (t, (struct GNUNET_CADET_ChannelManage *) msgh, fwd);
3044 GNUNET_break_op (0);
3045 LOG (GNUNET_ERROR_TYPE_WARNING,
3046 "end-to-end message not known (%u)\n",
3047 ntohs (msgh->type));
3048 GCT_debug (t, GNUNET_ERROR_TYPE_WARNING);
3053 /******************************************************************************/
3054 /******************************** API ***********************************/
3055 /******************************************************************************/
3057 * Decrypt old format and demultiplex by message type. Call appropriate handler
3058 * for a message towards a channel of a local tunnel.
3060 * @param t Tunnel this message came on.
3061 * @param msg Message header.
3064 GCT_handle_encrypted (struct CadetTunnel *t,
3065 const struct GNUNET_MessageHeader *msg)
3067 uint16_t size = ntohs (msg->size);
3069 size_t payload_size;
3072 const struct GNUNET_MessageHeader *msgh;
3075 type = ntohs (msg->type);
3078 case GNUNET_MESSAGE_TYPE_CADET_ENCRYPTED:
3080 const struct GNUNET_CADET_Encrypted *emsg;
3082 emsg = (const struct GNUNET_CADET_Encrypted *) msg;
3083 payload_size = size - sizeof (struct GNUNET_CADET_Encrypted);
3084 decrypted_size = t_decrypt_and_validate (t, cbuf, &emsg[1], payload_size,
3085 emsg->iv, &emsg->hmac);
3088 case GNUNET_MESSAGE_TYPE_CADET_AX:
3090 const struct GNUNET_CADET_AX *emsg;
3092 emsg = (const struct GNUNET_CADET_AX *) msg;
3093 decrypted_size = t_ax_decrypt_and_validate (t, cbuf, emsg, size);
3097 GNUNET_break_op (0);
3101 if (-1 == decrypted_size)
3103 GNUNET_break_op (0);
3104 LOG (GNUNET_ERROR_TYPE_WARNING, "Wrong crypto on tunnel %s\n", GCT_2s (t));
3105 GCT_debug (t, GNUNET_ERROR_TYPE_WARNING);
3108 GCT_change_estate (t, CADET_TUNNEL_KEY_OK);
3110 /* FIXME: this is bad, as the structs returned from
3111 this loop may be unaligned, see util's MST for
3112 how to do this right. */
3114 while (off < decrypted_size)
3118 msgh = (const struct GNUNET_MessageHeader *) &cbuf[off];
3119 msize = ntohs (msgh->size);
3120 if (msize < sizeof (struct GNUNET_MessageHeader))
3122 GNUNET_break_op (0);
3125 handle_decrypted (t, msgh, GNUNET_SYSERR);
3132 * Demultiplex an encapsulated KX message by message type.
3134 * @param t Tunnel on which the message came.
3135 * @param message Payload of KX message.
3138 GCT_handle_kx (struct CadetTunnel *t,
3139 const struct GNUNET_MessageHeader *message)
3143 type = ntohs (message->type);
3144 LOG (GNUNET_ERROR_TYPE_DEBUG, "kx message received: %s\n", GC_m2s (type));
3147 case GNUNET_MESSAGE_TYPE_CADET_KX_EPHEMERAL:
3148 handle_ephemeral (t, (const struct GNUNET_CADET_KX_Ephemeral *) message);
3151 case GNUNET_MESSAGE_TYPE_CADET_KX_PONG:
3152 handle_pong (t, (const struct GNUNET_CADET_KX_Pong *) message);
3155 case GNUNET_MESSAGE_TYPE_CADET_AX_KX:
3156 handle_kx_ax (t, (const struct GNUNET_CADET_AX_KX *) message);
3160 GNUNET_break_op (0);
3161 LOG (GNUNET_ERROR_TYPE_WARNING, "kx message %s unknown\n", GC_m2s (type));
3166 * Initialize the tunnel subsystem.
3168 * @param c Configuration handle.
3169 * @param key ECC private key, to derive all other keys and do crypto.
3172 GCT_init (const struct GNUNET_CONFIGURATION_Handle *c,
3173 const struct GNUNET_CRYPTO_EddsaPrivateKey *key)
3175 int expected_overhead;
3177 LOG (GNUNET_ERROR_TYPE_DEBUG, "init\n");
3179 expected_overhead = 0;
3180 expected_overhead += sizeof (struct GNUNET_CADET_Encrypted);
3181 expected_overhead += sizeof (struct GNUNET_CADET_Data);
3182 expected_overhead += sizeof (struct GNUNET_CADET_ACK);
3183 GNUNET_assert (GNUNET_CONSTANTS_CADET_P2P_OVERHEAD == expected_overhead);
3186 GNUNET_CONFIGURATION_get_value_number (c, "CADET", "DEFAULT_TTL",
3189 GNUNET_log_config_invalid (GNUNET_ERROR_TYPE_DEBUG,
3190 "CADET", "DEFAULT_TTL", "USING DEFAULT");
3194 GNUNET_CONFIGURATION_get_value_time (c, "CADET", "REKEY_PERIOD",
3197 rekey_period = GNUNET_TIME_UNIT_DAYS;
3200 GNUNET_CONFIGURATION_get_value_number (c, "CADET", "RATCHET_MESSAGES",
3203 GNUNET_log_config_invalid (GNUNET_ERROR_TYPE_WARNING,
3204 "CADET", "RATCHET_MESSAGES", "USING DEFAULT");
3205 ratchet_messages = 64;
3208 GNUNET_CONFIGURATION_get_value_time (c, "CADET", "RATCHET_TIME",
3211 GNUNET_log_config_invalid (GNUNET_ERROR_TYPE_WARNING,
3212 "CADET", "RATCHET_TIME", "USING DEFAULT");
3213 ratchet_time = GNUNET_TIME_UNIT_HOURS;
3219 otr_kx_msg.header.size = htons (sizeof (otr_kx_msg));
3220 otr_kx_msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_KX_EPHEMERAL);
3221 otr_kx_msg.purpose.purpose = htonl (GNUNET_SIGNATURE_PURPOSE_CADET_KX);
3222 otr_kx_msg.purpose.size = htonl (ephemeral_purpose_size ());
3223 otr_kx_msg.origin_identity = my_full_id;
3224 rekey_task = GNUNET_SCHEDULER_add_now (&global_otr_rekey, NULL);
3225 tunnels = GNUNET_CONTAINER_multipeermap_create (128, GNUNET_YES);
3230 * Shut down the tunnel subsystem.
3235 if (NULL != rekey_task)
3237 GNUNET_SCHEDULER_cancel (rekey_task);
3240 GNUNET_CONTAINER_multipeermap_iterate (tunnels, &destroy_iterator, NULL);
3241 GNUNET_CONTAINER_multipeermap_destroy (tunnels);
3248 * @param destination Peer this tunnel is towards.
3250 struct CadetTunnel *
3251 GCT_new (struct CadetPeer *destination)
3253 struct CadetTunnel *t;
3255 t = GNUNET_new (struct CadetTunnel);
3257 t->peer = destination;
3260 GNUNET_CONTAINER_multipeermap_put (tunnels, GCP_get_id (destination), t,
3261 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_FAST))
3267 t->ax = GNUNET_new (struct CadetTunnelAxolotl);
3269 t->ax->kx_0 = GNUNET_CRYPTO_ecdhe_key_create ();
3275 * Change the tunnel's connection state.
3277 * @param t Tunnel whose connection state to change.
3278 * @param cstate New connection state.
3281 GCT_change_cstate (struct CadetTunnel* t, enum CadetTunnelCState cstate)
3285 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel %s cstate %s => %s\n",
3286 GCP_2s (t->peer), cstate2s (t->cstate), cstate2s (cstate));
3287 if (myid != GCP_get_short_id (t->peer) &&
3288 CADET_TUNNEL_READY != t->cstate &&
3289 CADET_TUNNEL_READY == cstate)
3292 if (CADET_TUNNEL_KEY_OK == t->estate)
3294 LOG (GNUNET_ERROR_TYPE_DEBUG, " cstate triggered send queued data\n");
3295 send_queued_data (t);
3297 else if (CADET_TUNNEL_KEY_UNINITIALIZED == t->estate)
3299 LOG (GNUNET_ERROR_TYPE_DEBUG, " cstate triggered kx\n");
3300 GCT_send_ax_kx (t, GNUNET_NO);
3304 LOG (GNUNET_ERROR_TYPE_DEBUG, "estate %s\n", estate2s (t->estate));
3309 if (CADET_TUNNEL_READY == cstate
3310 && CONNECTIONS_PER_TUNNEL <= GCT_count_connections (t))
3312 LOG (GNUNET_ERROR_TYPE_DEBUG, " cstate triggered stop dht\n");
3313 GCP_stop_search (t->peer);
3319 * Change the tunnel encryption state.
3321 * If the encryption state changes to OK, stop the rekey task.
3323 * @param t Tunnel whose encryption state to change, or NULL.
3324 * @param state New encryption state.
3327 GCT_change_estate (struct CadetTunnel* t, enum CadetTunnelEState state)
3329 enum CadetTunnelEState old;
3336 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel %s estate was %s\n",
3337 GCP_2s (t->peer), estate2s (old));
3338 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel %s estate is now %s\n",
3339 GCP_2s (t->peer), estate2s (t->estate));
3341 if (CADET_TUNNEL_KEY_OK != old && CADET_TUNNEL_KEY_OK == t->estate)
3343 if (NULL != t->rekey_task)
3345 GNUNET_SCHEDULER_cancel (t->rekey_task);
3346 t->rekey_task = NULL;
3348 /* Send queued data if tunnel is not loopback */
3349 if (myid != GCP_get_short_id (t->peer))
3350 send_queued_data (t);
3356 * @brief Check if tunnel has too many connections, and remove one if necessary.
3358 * Currently this means the newest connection, unless it is a direct one.
3359 * Implemented as a task to avoid freeing a connection that is in the middle
3360 * of being created/processed.
3362 * @param cls Closure (Tunnel to check).
3363 * @param tc Task context.
3366 trim_connections (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
3368 struct CadetTunnel *t = cls;
3370 t->trim_connections_task = NULL;
3372 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
3375 if (GCT_count_connections (t) > 2 * CONNECTIONS_PER_TUNNEL)
3377 struct CadetTConnection *iter;
3378 struct CadetTConnection *c;
3380 for (c = iter = t->connection_head; NULL != iter; iter = iter->next)
3382 if ((iter->created.abs_value_us > c->created.abs_value_us)
3383 && GNUNET_NO == GCC_is_direct (iter->c))
3390 LOG (GNUNET_ERROR_TYPE_DEBUG, "Too many connections on tunnel %s\n",
3392 LOG (GNUNET_ERROR_TYPE_DEBUG, "Destroying connection %s\n",
3405 * Add a connection to a tunnel.
3408 * @param c Connection.
3411 GCT_add_connection (struct CadetTunnel *t, struct CadetConnection *c)
3413 struct CadetTConnection *aux;
3415 GNUNET_assert (NULL != c);
3417 LOG (GNUNET_ERROR_TYPE_DEBUG, "add connection %s\n", GCC_2s (c));
3418 LOG (GNUNET_ERROR_TYPE_DEBUG, " to tunnel %s\n", GCT_2s (t));
3419 for (aux = t->connection_head; aux != NULL; aux = aux->next)
3423 aux = GNUNET_new (struct CadetTConnection);
3425 aux->created = GNUNET_TIME_absolute_get ();
3427 GNUNET_CONTAINER_DLL_insert (t->connection_head, t->connection_tail, aux);
3429 if (CADET_TUNNEL_SEARCHING == t->cstate)
3430 GCT_change_cstate (t, CADET_TUNNEL_WAITING);
3432 if (NULL != t->trim_connections_task)
3433 t->trim_connections_task = GNUNET_SCHEDULER_add_now (&trim_connections, t);
3438 * Remove a connection from a tunnel.
3441 * @param c Connection.
3444 GCT_remove_connection (struct CadetTunnel *t,
3445 struct CadetConnection *c)
3447 struct CadetTConnection *aux;
3448 struct CadetTConnection *next;
3451 LOG (GNUNET_ERROR_TYPE_DEBUG, "Removing connection %s from tunnel %s\n",
3452 GCC_2s (c), GCT_2s (t));
3453 for (aux = t->connection_head; aux != NULL; aux = next)
3458 GNUNET_CONTAINER_DLL_remove (t->connection_head, t->connection_tail, aux);
3463 conns = GCT_count_connections (t);
3465 && NULL == t->destroy_task
3466 && CADET_TUNNEL_SHUTDOWN != t->cstate
3467 && GNUNET_NO == shutting_down)
3469 if (0 == GCT_count_any_connections (t))
3470 GCT_change_cstate (t, CADET_TUNNEL_SEARCHING);
3472 GCT_change_cstate (t, CADET_TUNNEL_WAITING);
3475 /* Start new connections if needed */
3476 if (CONNECTIONS_PER_TUNNEL > conns
3477 && NULL == t->destroy_task
3478 && CADET_TUNNEL_SHUTDOWN != t->cstate
3479 && GNUNET_NO == shutting_down)
3481 LOG (GNUNET_ERROR_TYPE_DEBUG, " too few connections, getting new ones\n");
3482 GCP_connect (t->peer); /* Will change cstate to WAITING when possible */
3486 /* If not marked as ready, no change is needed */
3487 if (CADET_TUNNEL_READY != t->cstate)
3490 /* Check if any connection is ready to maintain cstate */
3491 for (aux = t->connection_head; aux != NULL; aux = aux->next)
3492 if (CADET_CONNECTION_READY == GCC_get_state (aux->c))
3498 * Add a channel to a tunnel.
3501 * @param ch Channel.
3504 GCT_add_channel (struct CadetTunnel *t, struct CadetChannel *ch)
3506 struct CadetTChannel *aux;
3508 GNUNET_assert (NULL != ch);
3510 LOG (GNUNET_ERROR_TYPE_DEBUG, "Adding channel %p to tunnel %p\n", ch, t);
3512 for (aux = t->channel_head; aux != NULL; aux = aux->next)
3514 LOG (GNUNET_ERROR_TYPE_DEBUG, " already there %p\n", aux->ch);
3519 aux = GNUNET_new (struct CadetTChannel);
3521 LOG (GNUNET_ERROR_TYPE_DEBUG, " adding %p to %p\n", aux, t->channel_head);
3522 GNUNET_CONTAINER_DLL_insert_tail (t->channel_head, t->channel_tail, aux);
3524 if (NULL != t->destroy_task)
3526 GNUNET_SCHEDULER_cancel (t->destroy_task);
3527 t->destroy_task = NULL;
3528 LOG (GNUNET_ERROR_TYPE_DEBUG, " undo destroy!\n");
3534 * Remove a channel from a tunnel.
3537 * @param ch Channel.
3540 GCT_remove_channel (struct CadetTunnel *t, struct CadetChannel *ch)
3542 struct CadetTChannel *aux;
3544 LOG (GNUNET_ERROR_TYPE_DEBUG, "Removing channel %p from tunnel %p\n", ch, t);
3545 for (aux = t->channel_head; aux != NULL; aux = aux->next)
3549 LOG (GNUNET_ERROR_TYPE_DEBUG, " found! %s\n", GCCH_2s (ch));
3550 GNUNET_CONTAINER_DLL_remove (t->channel_head, t->channel_tail, aux);
3559 * Search for a channel by global ID.
3561 * @param t Tunnel containing the channel.
3562 * @param chid Public channel number.
3564 * @return channel handler, NULL if doesn't exist
3566 struct CadetChannel *
3567 GCT_get_channel (struct CadetTunnel *t, CADET_ChannelNumber chid)
3569 struct CadetTChannel *iter;
3574 for (iter = t->channel_head; NULL != iter; iter = iter->next)
3576 if (GCCH_get_id (iter->ch) == chid)
3580 return NULL == iter ? NULL : iter->ch;
3585 * @brief Destroy a tunnel and free all resources.
3587 * Should only be called a while after the tunnel has been marked as destroyed,
3588 * in case there is a new channel added to the same peer shortly after marking
3589 * the tunnel. This way we avoid a new public key handshake.
3591 * @param cls Closure (tunnel to destroy).
3592 * @param tc Task context.
3595 delayed_destroy (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
3597 struct CadetTunnel *t = cls;
3598 struct CadetTConnection *iter;
3600 LOG (GNUNET_ERROR_TYPE_DEBUG, "delayed destroying tunnel %p\n", t);
3601 if (0 != (GNUNET_SCHEDULER_REASON_SHUTDOWN & tc->reason))
3603 LOG (GNUNET_ERROR_TYPE_WARNING,
3604 "Not destroying tunnel, due to shutdown. "
3605 "Tunnel at %p should have been freed by GCT_shutdown\n", t);
3608 t->destroy_task = NULL;
3609 t->cstate = CADET_TUNNEL_SHUTDOWN;
3611 for (iter = t->connection_head; NULL != iter; iter = iter->next)
3613 GCC_send_destroy (iter->c);
3620 * Tunnel is empty: destroy it.
3622 * Notifies all connections about the destruction.
3624 * @param t Tunnel to destroy.
3627 GCT_destroy_empty (struct CadetTunnel *t)
3629 if (GNUNET_YES == shutting_down)
3630 return; /* Will be destroyed immediately anyway */
3632 if (NULL != t->destroy_task)
3634 LOG (GNUNET_ERROR_TYPE_WARNING,
3635 "Tunnel %s is already scheduled for destruction. Tunnel debug dump:\n",
3637 GCT_debug (t, GNUNET_ERROR_TYPE_WARNING);
3639 /* should never happen, tunnel can only become empty once, and the
3640 * task identifier should be NO_TASK (cleaned when the tunnel was created
3641 * or became un-empty)
3646 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel %s empty: scheduling destruction\n",
3649 // FIXME make delay a config option
3650 t->destroy_task = GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_MINUTES,
3651 &delayed_destroy, t);
3652 LOG (GNUNET_ERROR_TYPE_DEBUG, "Scheduled destroy of %p as %llu\n",
3653 t, t->destroy_task);
3658 * Destroy tunnel if empty (no more channels).
3660 * @param t Tunnel to destroy if empty.
3663 GCT_destroy_if_empty (struct CadetTunnel *t)
3665 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel %s destroy if empty\n", GCT_2s (t));
3666 if (0 < GCT_count_channels (t))
3669 GCT_destroy_empty (t);
3674 * Destroy the tunnel.
3676 * This function does not generate any warning traffic to clients or peers.
3679 * Cancel messages belonging to this tunnel queued to neighbors.
3680 * Free any allocated resources linked to the tunnel.
3682 * @param t The tunnel to destroy.
3685 GCT_destroy (struct CadetTunnel *t)
3687 struct CadetTConnection *iter_c;
3688 struct CadetTConnection *next_c;
3689 struct CadetTChannel *iter_ch;
3690 struct CadetTChannel *next_ch;
3691 unsigned int keepalives_queued;
3696 LOG (GNUNET_ERROR_TYPE_DEBUG, "destroying tunnel %s\n", GCP_2s (t->peer));
3698 GNUNET_break (GNUNET_YES ==
3699 GNUNET_CONTAINER_multipeermap_remove (tunnels,
3700 GCP_get_id (t->peer), t));
3702 for (iter_c = t->connection_head; NULL != iter_c; iter_c = next_c)
3704 next_c = iter_c->next;
3705 GCC_destroy (iter_c->c);
3707 for (iter_ch = t->channel_head; NULL != iter_ch; iter_ch = next_ch)
3709 next_ch = iter_ch->next;
3710 GCCH_destroy (iter_ch->ch);
3711 /* Should only happen on shutdown, but it's ok. */
3713 keepalives_queued = 0;
3714 while (NULL != t->tq_head)
3716 /* Should have been cleaned by destuction of channel. */
3717 struct GNUNET_MessageHeader *mh;
3720 mh = (struct GNUNET_MessageHeader *) &t->tq_head[1];
3721 type = ntohs (mh->type);
3722 if (0 == keepalives_queued && GNUNET_MESSAGE_TYPE_CADET_KEEPALIVE == type)
3724 keepalives_queued = 1;
3725 LOG (GNUNET_ERROR_TYPE_DEBUG,
3726 "one keepalive left behind on tunnel shutdown\n");
3731 LOG (GNUNET_ERROR_TYPE_WARNING,
3732 "message left behind on tunnel shutdown: %s\n",
3733 GC_m2s (ntohs (mh->type)));
3735 unqueue_data (t->tq_head);
3739 if (NULL != t->destroy_task)
3741 LOG (GNUNET_ERROR_TYPE_DEBUG, "cancelling dest: %llX\n", t->destroy_task);
3742 GNUNET_SCHEDULER_cancel (t->destroy_task);
3743 t->destroy_task = NULL;
3746 if (NULL != t->trim_connections_task)
3748 LOG (GNUNET_ERROR_TYPE_DEBUG, "cancelling trim: %llX\n",
3749 t->trim_connections_task);
3750 GNUNET_SCHEDULER_cancel (t->trim_connections_task);
3751 t->trim_connections_task = NULL;
3754 GNUNET_STATISTICS_update (stats, "# tunnels", -1, GNUNET_NO);
3755 GCP_set_tunnel (t->peer, NULL);
3757 if (NULL != t->rekey_task)
3759 GNUNET_SCHEDULER_cancel (t->rekey_task);
3760 t->rekey_task = NULL;
3762 if (NULL != t->kx_ctx)
3764 if (NULL != t->kx_ctx->finish_task)
3765 GNUNET_SCHEDULER_cancel (t->kx_ctx->finish_task);
3766 GNUNET_free (t->kx_ctx);
3777 * @brief Use the given path for the tunnel.
3778 * Update the next and prev hops (and RCs).
3779 * (Re)start the path refresh in case the tunnel is locally owned.
3781 * @param t Tunnel to update.
3782 * @param p Path to use.
3784 * @return Connection created.
3786 struct CadetConnection *
3787 GCT_use_path (struct CadetTunnel *t, struct CadetPeerPath *p)
3789 struct CadetConnection *c;
3790 struct GNUNET_CADET_Hash cid;
3791 unsigned int own_pos;
3793 if (NULL == t || NULL == p)
3799 if (CADET_TUNNEL_SHUTDOWN == t->cstate)
3805 for (own_pos = 0; own_pos < p->length; own_pos++)
3807 if (p->peers[own_pos] == myid)
3810 if (own_pos >= p->length)
3812 GNUNET_break_op (0);
3816 GNUNET_CRYPTO_random_block (GNUNET_CRYPTO_QUALITY_NONCE, &cid, sizeof (cid));
3817 c = GCC_new (&cid, t, p, own_pos);
3820 /* Path was flawed */
3823 GCT_add_connection (t, c);
3829 * Count all created connections of a tunnel. Not necessarily ready connections!
3831 * @param t Tunnel on which to count.
3833 * @return Number of connections created, either being established or ready.
3836 GCT_count_any_connections (struct CadetTunnel *t)
3838 struct CadetTConnection *iter;
3844 for (count = 0, iter = t->connection_head; NULL != iter; iter = iter->next)
3852 * Count established (ready) connections of a tunnel.
3854 * @param t Tunnel on which to count.
3856 * @return Number of connections.
3859 GCT_count_connections (struct CadetTunnel *t)
3861 struct CadetTConnection *iter;
3867 for (count = 0, iter = t->connection_head; NULL != iter; iter = iter->next)
3868 if (CADET_CONNECTION_READY == GCC_get_state (iter->c))
3876 * Count channels of a tunnel.
3878 * @param t Tunnel on which to count.
3880 * @return Number of channels.
3883 GCT_count_channels (struct CadetTunnel *t)
3885 struct CadetTChannel *iter;
3888 for (count = 0, iter = t->channel_head;
3890 iter = iter->next, count++) /* skip */;
3897 * Get the connectivity state of a tunnel.
3901 * @return Tunnel's connectivity state.
3903 enum CadetTunnelCState
3904 GCT_get_cstate (struct CadetTunnel *t)
3909 return (enum CadetTunnelCState) -1;
3916 * Get the encryption state of a tunnel.
3920 * @return Tunnel's encryption state.
3922 enum CadetTunnelEState
3923 GCT_get_estate (struct CadetTunnel *t)
3928 return (enum CadetTunnelEState) -1;
3934 * Get the maximum buffer space for a tunnel towards a local client.
3938 * @return Biggest buffer space offered by any channel in the tunnel.
3941 GCT_get_channels_buffer (struct CadetTunnel *t)
3943 struct CadetTChannel *iter;
3944 unsigned int buffer;
3945 unsigned int ch_buf;
3947 if (NULL == t->channel_head)
3949 /* Probably getting buffer for a channel create/handshake. */
3950 LOG (GNUNET_ERROR_TYPE_DEBUG, " no channels, allow max\n");
3951 return MIN_TUNNEL_BUFFER;
3955 for (iter = t->channel_head; NULL != iter; iter = iter->next)
3957 ch_buf = get_channel_buffer (iter);
3958 if (ch_buf > buffer)
3961 if (MIN_TUNNEL_BUFFER > buffer)
3962 return MIN_TUNNEL_BUFFER;
3964 if (MAX_TUNNEL_BUFFER < buffer)
3967 return MAX_TUNNEL_BUFFER;
3974 * Get the total buffer space for a tunnel for P2P traffic.
3978 * @return Buffer space offered by all connections in the tunnel.
3981 GCT_get_connections_buffer (struct CadetTunnel *t)
3983 struct CadetTConnection *iter;
3984 unsigned int buffer;
3986 if (GNUNET_NO == is_ready (t))
3988 if (count_queued_data (t) >= 3)
3995 for (iter = t->connection_head; NULL != iter; iter = iter->next)
3997 if (GCC_get_state (iter->c) != CADET_CONNECTION_READY)
4001 buffer += get_connection_buffer (iter);
4009 * Get the tunnel's destination.
4013 * @return ID of the destination peer.
4015 const struct GNUNET_PeerIdentity *
4016 GCT_get_destination (struct CadetTunnel *t)
4018 return GCP_get_id (t->peer);
4023 * Get the tunnel's next free global channel ID.
4027 * @return GID of a channel free to use.
4030 GCT_get_next_chid (struct CadetTunnel *t)
4032 CADET_ChannelNumber chid;
4033 CADET_ChannelNumber mask;
4036 /* Set bit 30 depending on the ID relationship. Bit 31 is always 0 for GID.
4037 * If our ID is bigger or loopback tunnel, start at 0, bit 30 = 0
4038 * If peer's ID is bigger, start at 0x4... bit 30 = 1
4040 result = GNUNET_CRYPTO_cmp_peer_identity (&my_full_id, GCP_get_id (t->peer));
4045 t->next_chid |= mask;
4047 while (NULL != GCT_get_channel (t, t->next_chid))
4049 LOG (GNUNET_ERROR_TYPE_DEBUG, "Channel %u exists...\n", t->next_chid);
4050 t->next_chid = (t->next_chid + 1) & ~GNUNET_CADET_LOCAL_CHANNEL_ID_CLI;
4051 t->next_chid |= mask;
4053 chid = t->next_chid;
4054 t->next_chid = (t->next_chid + 1) & ~GNUNET_CADET_LOCAL_CHANNEL_ID_CLI;
4055 t->next_chid |= mask;
4062 * Send ACK on one or more channels due to buffer in connections.
4064 * @param t Channel which has some free buffer space.
4067 GCT_unchoke_channels (struct CadetTunnel *t)
4069 struct CadetTChannel *iter;
4070 unsigned int buffer;
4071 unsigned int channels = GCT_count_channels (t);
4072 unsigned int choked_n;
4073 struct CadetChannel *choked[channels];
4075 LOG (GNUNET_ERROR_TYPE_DEBUG, "GCT_unchoke_channels on %s\n", GCT_2s (t));
4076 LOG (GNUNET_ERROR_TYPE_DEBUG, " head: %p\n", t->channel_head);
4077 if (NULL != t->channel_head)
4078 LOG (GNUNET_ERROR_TYPE_DEBUG, " head ch: %p\n", t->channel_head->ch);
4080 if (NULL != t->tq_head)
4081 send_queued_data (t);
4083 /* Get buffer space */
4084 buffer = GCT_get_connections_buffer (t);
4090 /* Count and remember choked channels */
4092 for (iter = t->channel_head; NULL != iter; iter = iter->next)
4094 if (GNUNET_NO == get_channel_allowed (iter))
4096 choked[choked_n++] = iter->ch;
4100 /* Unchoke random channels */
4101 while (0 < buffer && 0 < choked_n)
4103 unsigned int r = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK,
4105 GCCH_allow_client (choked[r], GCCH_is_origin (choked[r], GNUNET_YES));
4108 choked[r] = choked[choked_n];
4114 * Send ACK on one or more connections due to buffer space to the client.
4116 * Iterates all connections of the tunnel and sends ACKs appropriately.
4121 GCT_send_connection_acks (struct CadetTunnel *t)
4123 struct CadetTConnection *iter;
4126 uint32_t allow_per_connection;
4128 unsigned int buffer;
4130 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel send connection ACKs on %s\n",
4139 if (CADET_TUNNEL_READY != t->cstate)
4142 buffer = GCT_get_channels_buffer (t);
4143 LOG (GNUNET_ERROR_TYPE_DEBUG, " buffer %u\n", buffer);
4145 /* Count connections, how many messages are already allowed */
4146 cs = GCT_count_connections (t);
4147 for (allowed = 0, iter = t->connection_head; NULL != iter; iter = iter->next)
4149 allowed += get_connection_allowed (iter);
4151 LOG (GNUNET_ERROR_TYPE_DEBUG, " allowed %u\n", allowed);
4153 /* Make sure there is no overflow */
4154 if (allowed > buffer)
4157 /* Authorize connections to send more data */
4158 to_allow = buffer - allowed;
4160 for (iter = t->connection_head;
4161 NULL != iter && to_allow > 0;
4164 if (CADET_CONNECTION_READY != GCC_get_state (iter->c)
4165 || get_connection_allowed (iter) > 64 / 3)
4169 allow_per_connection = to_allow/cs;
4170 to_allow -= allow_per_connection;
4172 GCC_allow (iter->c, allow_per_connection,
4173 GCC_is_origin (iter->c, GNUNET_NO));
4178 /* Since we don't allow if it's allowed to send 64/3, this can happen. */
4179 LOG (GNUNET_ERROR_TYPE_DEBUG, " reminding to_allow: %u\n", to_allow);
4185 * Cancel a previously sent message while it's in the queue.
4187 * ONLY can be called before the continuation given to the send function
4188 * is called. Once the continuation is called, the message is no longer in the
4191 * @param q Handle to the queue.
4194 GCT_cancel (struct CadetTunnelQueue *q)
4198 GNUNET_assert (NULL == q->tqd);
4200 /* tun_message_sent() will be called and free q */
4202 else if (NULL != q->tqd)
4204 unqueue_data (q->tqd);
4206 if (NULL != q->cont)
4207 q->cont (q->cont_cls, NULL, q, 0, 0);
4218 * Check if the tunnel has queued traffic.
4220 * @param t Tunnel to check.
4222 * @return #GNUNET_YES if there is queued traffic
4223 * #GNUNET_NO otherwise
4226 GCT_has_queued_traffic (struct CadetTunnel *t)
4228 return (NULL != t->tq_head) ? GNUNET_YES : GNUNET_NO;
4233 * Sends an already built message on a tunnel, encrypting it and
4234 * choosing the best connection if not provided.
4236 * @param message Message to send. Function modifies it.
4237 * @param t Tunnel on which this message is transmitted.
4238 * @param c Connection to use (autoselect if NULL).
4239 * @param force Force the tunnel to take the message (buffer overfill).
4240 * @param cont Continuation to call once message is really sent.
4241 * @param cont_cls Closure for @c cont.
4243 * @return Handle to cancel message. NULL if @c cont is NULL.
4245 struct CadetTunnelQueue *
4246 GCT_send_prebuilt_message (const struct GNUNET_MessageHeader *message,
4247 struct CadetTunnel *t, struct CadetConnection *c,
4248 int force, GCT_sent cont, void *cont_cls)
4250 return send_prebuilt_message (message, t, c, force, cont, cont_cls, NULL);
4255 * Send an Axolotl KX message.
4257 * @param t Tunnel on which to send it.
4258 * @param force_reply Force the other peer to reply with a KX message.
4261 GCT_send_ax_kx (struct CadetTunnel *t, int force_reply)
4263 struct GNUNET_CADET_AX_KX msg;
4264 enum GNUNET_CADET_AX_KX_Flags flags;
4266 LOG (GNUNET_ERROR_TYPE_INFO, "===> AX_KX for %s\n", GCT_2s (t));
4267 if (NULL != t->ephm_h)
4269 LOG (GNUNET_ERROR_TYPE_INFO, " already queued\n");
4273 msg.header.size = htons (sizeof (msg));
4274 msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_AX_KX);
4275 flags = GNUNET_CADET_AX_KX_FLAG_NONE;
4277 flags |= GNUNET_CADET_AX_KX_FLAG_FORCE_REPLY;
4278 msg.flags = htonl (flags);
4279 GNUNET_CRYPTO_ecdhe_key_get_public (t->ax->kx_0, &msg.ephemeral_key);
4280 GNUNET_CRYPTO_ecdhe_key_get_public (t->ax->DHRs, &msg.ratchet_key);
4282 t->ephm_h = send_kx (t, &msg.header);
4283 if (CADET_TUNNEL_KEY_OK != t->estate)
4284 GCT_change_estate (t, CADET_TUNNEL_KEY_SENT);
4289 * Sends an already built and encrypted message on a tunnel, choosing the best
4290 * connection. Useful for re-queueing messages queued on a destroyed connection.
4292 * @param message Message to send. Function modifies it.
4293 * @param t Tunnel on which this message is transmitted.
4296 GCT_resend_message (const struct GNUNET_MessageHeader *message,
4297 struct CadetTunnel *t)
4299 struct CadetConnection *c;
4302 c = tunnel_get_connection (t);
4305 /* TODO queue in tunnel, marked as encrypted */
4306 LOG (GNUNET_ERROR_TYPE_DEBUG, "No connection available, dropping.\n");
4309 fwd = GCC_is_origin (c, GNUNET_YES);
4310 GNUNET_break (NULL == GCC_send_prebuilt_message (message, 0, 0, c, fwd,
4311 GNUNET_YES, NULL, NULL));
4316 * Is the tunnel directed towards the local peer?
4320 * @return #GNUNET_YES if it is loopback.
4323 GCT_is_loopback (const struct CadetTunnel *t)
4325 return (myid == GCP_get_short_id (t->peer));
4330 * Is the tunnel this path already?
4335 * @return #GNUNET_YES a connection uses this path.
4338 GCT_is_path_used (const struct CadetTunnel *t, const struct CadetPeerPath *p)
4340 struct CadetTConnection *iter;
4342 for (iter = t->connection_head; NULL != iter; iter = iter->next)
4343 if (path_equivalent (GCC_get_path (iter->c), p))
4351 * Get a cost of a path for a tunnel considering existing connections.
4354 * @param path Candidate path.
4356 * @return Cost of the path (path length + number of overlapping nodes)
4359 GCT_get_path_cost (const struct CadetTunnel *t,
4360 const struct CadetPeerPath *path)
4362 struct CadetTConnection *iter;
4363 const struct CadetPeerPath *aux;
4364 unsigned int overlap;
4372 GNUNET_assert (NULL != t);
4374 for (i = 0; i < path->length; i++)
4376 for (iter = t->connection_head; NULL != iter; iter = iter->next)
4378 aux = GCC_get_path (iter->c);
4382 for (j = 0; j < aux->length; j++)
4384 if (path->peers[i] == aux->peers[j])
4392 return path->length + overlap;
4397 * Get the static string for the peer this tunnel is directed.
4401 * @return Static string the destination peer's ID.
4404 GCT_2s (const struct CadetTunnel *t)
4409 return GCP_2s (t->peer);
4413 /******************************************************************************/
4414 /***************************** INFO/DEBUG *******************************/
4415 /******************************************************************************/
4418 ax_debug (const struct CadetTunnelAxolotl *ax, enum GNUNET_ErrorType level)
4420 struct GNUNET_CRYPTO_EcdhePublicKey pub;
4421 struct CadetTunnelSkippedKey *iter;
4423 LOG2 (level, "TTT RK \t %s\n",
4424 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &ax->RK));
4426 LOG2 (level, "TTT HKs \t %s\n",
4427 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &ax->HKs));
4428 LOG2 (level, "TTT HKr \t %s\n",
4429 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &ax->HKr));
4430 LOG2 (level, "TTT NHKs\t %s\n",
4431 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &ax->NHKs));
4432 LOG2 (level, "TTT NHKr\t %s\n",
4433 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &ax->NHKr));
4435 LOG2 (level, "TTT CKs \t %s\n",
4436 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &ax->CKs));
4437 LOG2 (level, "TTT CKr \t %s\n",
4438 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &ax->CKr));
4440 GNUNET_CRYPTO_ecdhe_key_get_public (ax->DHRs, &pub);
4441 LOG2 (level, "TTT DHRs\t %s\n",
4442 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &pub));
4443 LOG2 (level, "TTT DHRr\t %s\n",
4444 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &ax->DHRr));
4446 LOG2 (level, "TTT Nr\t %u\tNs\t%u\n", ax->Nr, ax->Ns);
4447 LOG2 (level, "TTT PNs\t %u\tSkipped\t%u\n", ax->PNs, ax->skipped);
4448 LOG2 (level, "TTT Ratchet\t%u\n", ax->ratchet_flag);
4450 for (iter = ax->skipped_head; NULL != iter; iter = iter->next)
4452 LOG2 (level, "TTT HK\t %s\n",
4453 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &iter->HK));
4454 LOG2 (level, "TTT MK\t %s\n",
4455 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &iter->MK));
4460 * Log all possible info about the tunnel state.
4462 * @param t Tunnel to debug.
4463 * @param level Debug level to use.
4466 GCT_debug (const struct CadetTunnel *t, enum GNUNET_ErrorType level)
4468 struct CadetTChannel *iterch;
4469 struct CadetTConnection *iterc;
4472 do_log = GNUNET_get_log_call_status (level & (~GNUNET_ERROR_TYPE_BULK),
4474 __FILE__, __FUNCTION__, __LINE__);
4478 LOG2 (level, "TTT DEBUG TUNNEL TOWARDS %s\n", GCT_2s (t));
4479 LOG2 (level, "TTT cstate %s, estate %s\n",
4480 cstate2s (t->cstate), estate2s (t->estate));
4481 LOG2 (level, "TTT kx_ctx %p, rekey_task %u, finish task %u\n",
4482 t->kx_ctx, t->rekey_task, t->kx_ctx ? t->kx_ctx->finish_task : 0);
4483 #if DUMP_KEYS_TO_STDERR
4484 if (CADET_Axolotl == t->enc_type)
4486 ax_debug (t->ax, level);
4490 LOG2 (level, "TTT my EPHM\t %s\n",
4491 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &otr_kx_msg.ephemeral_key));
4492 LOG2 (level, "TTT peers EPHM:\t %s\n",
4493 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &t->peers_ephemeral_key));
4494 LOG2 (level, "TTT ENC key:\t %s\n",
4495 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &t->e_key));
4496 LOG2 (level, "TTT DEC key:\t %s\n",
4497 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &t->d_key));
4500 LOG2 (level, "TTT OLD ENC key:\t %s\n",
4501 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &t->kx_ctx->e_key_old));
4502 LOG2 (level, "TTT OLD DEC key:\t %s\n",
4503 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &t->kx_ctx->d_key_old));
4507 LOG2 (level, "TTT tq_head %p, tq_tail %p\n", t->tq_head, t->tq_tail);
4508 LOG2 (level, "TTT destroy %u\n", t->destroy_task);
4510 LOG2 (level, "TTT channels:\n");
4511 for (iterch = t->channel_head; NULL != iterch; iterch = iterch->next)
4513 LOG2 (level, "TTT - %s\n", GCCH_2s (iterch->ch));
4516 LOG2 (level, "TTT connections:\n");
4517 for (iterc = t->connection_head; NULL != iterc; iterc = iterc->next)
4519 GCC_debug (iterc->c, level);
4522 LOG2 (level, "TTT DEBUG TUNNEL END\n");
4527 * Iterate all tunnels.
4529 * @param iter Iterator.
4530 * @param cls Closure for @c iter.
4533 GCT_iterate_all (GNUNET_CONTAINER_PeerMapIterator iter, void *cls)
4535 GNUNET_CONTAINER_multipeermap_iterate (tunnels, iter, cls);
4540 * Count all tunnels.
4542 * @return Number of tunnels to remote peers kept by this peer.
4545 GCT_count_all (void)
4547 return GNUNET_CONTAINER_multipeermap_size (tunnels);
4552 * Iterate all connections of a tunnel.
4554 * @param t Tunnel whose connections to iterate.
4555 * @param iter Iterator.
4556 * @param cls Closure for @c iter.
4559 GCT_iterate_connections (struct CadetTunnel *t, GCT_conn_iter iter, void *cls)
4561 struct CadetTConnection *ct;
4563 for (ct = t->connection_head; NULL != ct; ct = ct->next)
4569 * Iterate all channels of a tunnel.
4571 * @param t Tunnel whose channels to iterate.
4572 * @param iter Iterator.
4573 * @param cls Closure for @c iter.
4576 GCT_iterate_channels (struct CadetTunnel *t, GCT_chan_iter iter, void *cls)
4578 struct CadetTChannel *cht;
4580 for (cht = t->channel_head; NULL != cht; cht = cht->next)
4581 iter (cls, cht->ch);