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 key->HK = t->ax->HKr;
1380 t_hmac_derive_key (&t->ax->CKr, &key->MK, "0", 1);
1381 #if DUMP_KEYS_TO_STDERR
1382 LOG (GNUNET_ERROR_TYPE_INFO, " storing MK for Nr %u: %s\n",
1383 t->ax->Nr, GNUNET_i2s ((struct GNUNET_PeerIdentity *) &key->MK));
1384 LOG (GNUNET_ERROR_TYPE_INFO, " for CKr: %s\n",
1385 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &t->ax->CKr));
1387 t_hmac_derive_key (&t->ax->CKr, &t->ax->CKr, "1", 1);
1388 GNUNET_CONTAINER_DLL_insert (t->ax->skipped_head, t->ax->skipped_tail, key);
1395 * Delete a key from the list of skipped keys.
1397 * @param t Tunnel to delete from.
1398 * @param key Key to delete.
1401 delete_skipped_key (struct CadetTunnel *t, struct CadetTunnelSkippedKey *key)
1403 GNUNET_CONTAINER_DLL_remove (t->ax->skipped_head, t->ax->skipped_tail, key);
1410 * Stage skipped AX keys and calculate the message key.
1412 * Stores each HK and MK for skipped messages.
1414 * @param t Tunnel where to stage the keys.
1415 * @param HKr Header key.
1416 * @param Np Received meesage number.
1419 store_ax_keys (struct CadetTunnel *t,
1420 const struct GNUNET_CRYPTO_SymmetricSessionKey *HKr,
1425 gap = Np - t->ax->Nr;
1426 if (MAX_KEY_GAP < gap || 0 > gap)
1428 /* Avoid DoS (forcing peer to do 2*33 chain HMAC operations) */
1429 /* TODO: start new key exchange on return */
1430 GNUNET_break_op (0);
1431 LOG (GNUNET_ERROR_TYPE_WARNING, "Got message %u, expected %u+\n",
1436 while (t->ax->Nr < Np)
1437 store_skipped_key (t, HKr);
1439 while (t->ax->skipped > MAX_SKIPPED_KEYS)
1440 delete_skipped_key (t, t->ax->skipped_tail);
1445 * Decrypt and verify data with the appropriate tunnel key and verify that the
1446 * data has not been altered since it was sent by the remote peer.
1448 * @param t Tunnel whose key to use.
1449 * @param dst Destination for the plaintext.
1450 * @param src Source of the message. Can overlap with @c dst.
1451 * @param size Size of the message.
1453 * @return Size of the decrypted data, -1 if an error was encountered.
1456 t_ax_decrypt_and_validate (struct CadetTunnel *t, void *dst,
1457 const struct GNUNET_CADET_AX *src, size_t size)
1459 struct CadetTunnelAxolotl *ax;
1460 struct GNUNET_CADET_Hash msg_hmac;
1461 struct GNUNET_HashCode hmac;
1462 struct GNUNET_CADET_AX *dstmsg;
1470 esize = size - sizeof (struct GNUNET_CADET_AX);
1475 /* Try current HK */
1476 t_hmac (&src->Ns, AX_HEADER_SIZE + esize, 0, &ax->HKr, &msg_hmac);
1477 if (0 != memcmp (&msg_hmac, &src->hmac, sizeof (msg_hmac)))
1479 static const char ctx[] = "axolotl ratchet";
1480 struct GNUNET_CRYPTO_SymmetricSessionKey keys[3]; /* RKp, NHKp, CKp */
1481 struct GNUNET_CRYPTO_SymmetricSessionKey HK;
1482 struct GNUNET_HashCode dh;
1483 struct GNUNET_CRYPTO_EcdhePublicKey *DHRp;
1486 t_hmac (&src->Ns, AX_HEADER_SIZE + esize, 0, &ax->NHKr, &msg_hmac);
1487 if (0 != memcmp (&msg_hmac, &src->hmac, sizeof (msg_hmac)))
1489 /* Try the skipped keys, if that fails, we're out of luck. */
1490 return try_old_ax_keys (t, dst, src, size);
1492 LOG (GNUNET_ERROR_TYPE_INFO, "next HK\n");
1496 t_h_decrypt (t, src, dstmsg);
1497 Np = ntohl (dstmsg->Ns);
1498 PNp = ntohl (dstmsg->PNs);
1499 DHRp = &dstmsg->DHRs;
1500 store_ax_keys (t, &HK, PNp);
1502 /* RKp, NHKp, CKp = KDF (HMAC-HASH (RK, DH (DHRp, DHRs))) */
1503 GNUNET_CRYPTO_ecc_ecdh (ax->DHRs, DHRp, &dh);
1504 t_ax_hmac_hash (&ax->RK, &hmac, &dh, sizeof (dh));
1505 GNUNET_CRYPTO_kdf (keys, sizeof (keys), ctx, sizeof (ctx),
1506 &hmac, sizeof (hmac), NULL);
1508 /* Commit "purported" keys */
1514 ax->ratchet_allowed = GNUNET_YES;
1518 LOG (GNUNET_ERROR_TYPE_DEBUG, "current HK\n");
1519 t_h_decrypt (t, src, dstmsg);
1520 Np = ntohl (dstmsg->Ns);
1521 PNp = ntohl (dstmsg->PNs);
1525 store_ax_keys (t, &ax->HKr, Np);
1529 osize = t_ax_decrypt (t, dst, &src[1], esize);
1532 GNUNET_break_op (0);
1541 * Create key material by doing ECDH on the local and remote ephemeral keys.
1543 * @param key_material Where to store the key material.
1544 * @param ephemeral Peer's public ephemeral key.
1546 * @return GNUNET_OK if it went fine, GNUNET_SYSERR otherwise.
1549 derive_otr_key_material (struct GNUNET_HashCode *key_material,
1550 const struct GNUNET_CRYPTO_EcdhePublicKey *ephemeral)
1553 GNUNET_CRYPTO_ecc_ecdh (otr_ephemeral_key, ephemeral, key_material))
1556 return GNUNET_SYSERR;
1563 * Create a symmetic key from the identities of both ends and the key material
1566 * @param key Destination for the generated key.
1567 * @param sender ID of the peer that will encrypt with @c key.
1568 * @param receiver ID of the peer that will decrypt with @c key.
1569 * @param key_material Hash created with ECDH with the ephemeral keys.
1572 derive_symmertic (struct GNUNET_CRYPTO_SymmetricSessionKey *key,
1573 const struct GNUNET_PeerIdentity *sender,
1574 const struct GNUNET_PeerIdentity *receiver,
1575 const struct GNUNET_HashCode *key_material)
1577 const char salt[] = "CADET kx salt";
1579 GNUNET_CRYPTO_kdf (key, sizeof (struct GNUNET_CRYPTO_SymmetricSessionKey),
1580 salt, sizeof (salt),
1581 key_material, sizeof (struct GNUNET_HashCode),
1582 sender, sizeof (struct GNUNET_PeerIdentity),
1583 receiver, sizeof (struct GNUNET_PeerIdentity),
1589 * Derive the tunnel's keys using our own and the peer's ephemeral keys.
1591 * @param t Tunnel for which to create the keys.
1593 * @return GNUNET_OK if successful, GNUNET_SYSERR otherwise.
1596 create_otr_keys (struct CadetTunnel *t)
1598 struct GNUNET_HashCode km;
1600 if (GNUNET_OK != derive_otr_key_material (&km, &t->peers_ephemeral_key))
1601 return GNUNET_SYSERR;
1602 derive_symmertic (&t->e_key, &my_full_id, GCP_get_id (t->peer), &km);
1603 derive_symmertic (&t->d_key, GCP_get_id (t->peer), &my_full_id, &km);
1604 #if DUMP_KEYS_TO_STDERR
1605 LOG (GNUNET_ERROR_TYPE_INFO, "ME: %s\n",
1606 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &otr_kx_msg.ephemeral_key));
1607 LOG (GNUNET_ERROR_TYPE_INFO, "PE: %s\n",
1608 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &t->peers_ephemeral_key));
1609 LOG (GNUNET_ERROR_TYPE_INFO, "KM: %s\n", GNUNET_h2s (&km));
1610 LOG (GNUNET_ERROR_TYPE_INFO, "EK: %s\n",
1611 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &t->e_key));
1612 LOG (GNUNET_ERROR_TYPE_INFO, "DK: %s\n",
1613 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &t->d_key));
1620 * Create a new Key eXchange context for the tunnel.
1622 * If the old keys were verified, keep them for old traffic. Create a new KX
1623 * timestamp and a new nonce.
1625 * @param t Tunnel for which to create the KX ctx.
1627 * @return GNUNET_OK if successful, GNUNET_SYSERR otherwise.
1630 create_kx_ctx (struct CadetTunnel *t)
1632 LOG (GNUNET_ERROR_TYPE_INFO, " new kx ctx for %s\n", GCT_2s (t));
1634 if (NULL != t->kx_ctx)
1636 if (NULL != t->kx_ctx->finish_task)
1638 LOG (GNUNET_ERROR_TYPE_INFO, " resetting exisiting finish task\n");
1639 GNUNET_SCHEDULER_cancel (t->kx_ctx->finish_task);
1640 t->kx_ctx->finish_task = NULL;
1645 t->kx_ctx = GNUNET_new (struct CadetTunnelKXCtx);
1646 t->kx_ctx->challenge = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE,
1650 if (CADET_TUNNEL_KEY_OK == t->estate)
1652 LOG (GNUNET_ERROR_TYPE_INFO, " backing up keys\n");
1653 t->kx_ctx->d_key_old = t->d_key;
1654 t->kx_ctx->e_key_old = t->e_key;
1657 LOG (GNUNET_ERROR_TYPE_INFO, " old keys not valid, not saving\n");
1658 t->kx_ctx->rekey_start_time = GNUNET_TIME_absolute_get ();
1659 return create_otr_keys (t);
1664 * @brief Finish the Key eXchange and destroy the old keys.
1666 * @param cls Closure (Tunnel for which to finish the KX).
1667 * @param tc Task context.
1670 finish_kx (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
1672 struct CadetTunnel *t = cls;
1674 LOG (GNUNET_ERROR_TYPE_INFO, "finish KX for %s\n", GCT_2s (t));
1676 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
1678 LOG (GNUNET_ERROR_TYPE_INFO, " shutdown\n");
1682 GNUNET_free (t->kx_ctx);
1688 * Destroy a Key eXchange context for the tunnel. This function only schedules
1689 * the destruction, the freeing of the memory (and clearing of old key material)
1690 * happens after a delay!
1692 * @param t Tunnel whose KX ctx to destroy.
1695 destroy_kx_ctx (struct CadetTunnel *t)
1697 struct GNUNET_TIME_Relative delay;
1699 if (NULL == t->kx_ctx || NULL != t->kx_ctx->finish_task)
1702 if (is_key_null (&t->kx_ctx->e_key_old))
1704 t->kx_ctx->finish_task = GNUNET_SCHEDULER_add_now (finish_kx, t);
1708 delay = GNUNET_TIME_relative_divide (rekey_period, 4);
1709 delay = GNUNET_TIME_relative_min (delay, GNUNET_TIME_UNIT_MINUTES);
1711 t->kx_ctx->finish_task = GNUNET_SCHEDULER_add_delayed (delay, finish_kx, t);
1717 * Pick a connection on which send the next data message.
1719 * @param t Tunnel on which to send the message.
1721 * @return The connection on which to send the next message.
1723 static struct CadetConnection *
1724 tunnel_get_connection (struct CadetTunnel *t)
1726 struct CadetTConnection *iter;
1727 struct CadetConnection *best;
1729 unsigned int lowest_q;
1731 LOG (GNUNET_ERROR_TYPE_DEBUG, "tunnel_get_connection %s\n", GCT_2s (t));
1733 lowest_q = UINT_MAX;
1734 for (iter = t->connection_head; NULL != iter; iter = iter->next)
1736 LOG (GNUNET_ERROR_TYPE_DEBUG, " connection %s: %u\n",
1737 GCC_2s (iter->c), GCC_get_state (iter->c));
1738 if (CADET_CONNECTION_READY == GCC_get_state (iter->c))
1740 qn = GCC_get_qn (iter->c, GCC_is_origin (iter->c, GNUNET_YES));
1741 LOG (GNUNET_ERROR_TYPE_DEBUG, " q_n %u, \n", qn);
1749 LOG (GNUNET_ERROR_TYPE_DEBUG, " selected: connection %s\n", GCC_2s (best));
1755 * Callback called when a queued message is sent.
1757 * Calculates the average time and connection packet tracking.
1759 * @param cls Closure (TunnelQueue handle).
1760 * @param c Connection this message was on.
1761 * @param q Connection queue handle (unused).
1762 * @param type Type of message sent.
1763 * @param fwd Was this a FWD going message?
1764 * @param size Size of the message.
1767 tun_message_sent (void *cls,
1768 struct CadetConnection *c,
1769 struct CadetConnectionQueue *q,
1770 uint16_t type, int fwd, size_t size)
1772 struct CadetTunnelQueue *qt = cls;
1773 struct CadetTunnel *t;
1775 LOG (GNUNET_ERROR_TYPE_DEBUG, "tun_message_sent\n");
1777 GNUNET_assert (NULL != qt->cont);
1778 t = NULL == c ? NULL : GCC_get_tunnel (c);
1779 qt->cont (qt->cont_cls, t, qt, type, size);
1785 count_queued_data (const struct CadetTunnel *t)
1787 struct CadetTunnelDelayed *iter;
1790 for (count = 0, iter = t->tq_head; iter != NULL; iter = iter->next)
1797 * Delete a queued message: either was sent or the channel was destroyed
1798 * before the tunnel's key exchange had a chance to finish.
1800 * @param tqd Delayed queue handle.
1803 unqueue_data (struct CadetTunnelDelayed *tqd)
1805 GNUNET_CONTAINER_DLL_remove (tqd->t->tq_head, tqd->t->tq_tail, tqd);
1811 * Cache a message to be sent once tunnel is online.
1813 * @param t Tunnel to hold the message.
1814 * @param msg Message itself (copy will be made).
1816 static struct CadetTunnelDelayed *
1817 queue_data (struct CadetTunnel *t, const struct GNUNET_MessageHeader *msg)
1819 struct CadetTunnelDelayed *tqd;
1820 uint16_t size = ntohs (msg->size);
1822 LOG (GNUNET_ERROR_TYPE_DEBUG, "queue data on Tunnel %s\n", GCT_2s (t));
1824 GNUNET_assert (GNUNET_NO == is_ready (t));
1826 tqd = GNUNET_malloc (sizeof (struct CadetTunnelDelayed) + size);
1829 memcpy (&tqd[1], msg, size);
1830 GNUNET_CONTAINER_DLL_insert_tail (t->tq_head, t->tq_tail, tqd);
1836 * Sends an already built message on a tunnel, encrypting it and
1837 * choosing the best connection.
1839 * @param message Message to send. Function modifies it.
1840 * @param t Tunnel on which this message is transmitted.
1841 * @param c Connection to use (autoselect if NULL).
1842 * @param force Force the tunnel to take the message (buffer overfill).
1843 * @param cont Continuation to call once message is really sent.
1844 * @param cont_cls Closure for @c cont.
1845 * @param existing_q In case this a transmission of previously queued data,
1846 * this should be TunnelQueue given to the client.
1849 * @return Handle to cancel message.
1850 * NULL if @c cont is NULL or an error happens and message is dropped.
1852 static struct CadetTunnelQueue *
1853 send_prebuilt_message (const struct GNUNET_MessageHeader *message,
1854 struct CadetTunnel *t, struct CadetConnection *c,
1855 int force, GCT_sent cont, void *cont_cls,
1856 struct CadetTunnelQueue *existing_q)
1858 struct GNUNET_MessageHeader *msg;
1859 struct GNUNET_CADET_Encrypted *otr_msg;
1860 struct GNUNET_CADET_AX *ax_msg;
1861 struct CadetTunnelQueue *tq;
1862 size_t size = ntohs (message->size);
1863 const uint16_t max_overhead = sizeof (struct GNUNET_CADET_Encrypted)
1864 + sizeof (struct GNUNET_CADET_AX);
1865 char cbuf[max_overhead + size];
1872 LOG (GNUNET_ERROR_TYPE_DEBUG, "GMT Send on Tunnel %s\n", GCT_2s (t));
1874 if (GNUNET_NO == is_ready (t))
1876 struct CadetTunnelDelayed *tqd;
1877 /* A non null existing_q indicates sending of queued data.
1878 * Should only happen after tunnel becomes ready.
1880 GNUNET_assert (NULL == existing_q);
1881 tqd = queue_data (t, message);
1884 tq = GNUNET_new (struct CadetTunnelQueue);
1888 tq->cont_cls = cont_cls;
1892 GNUNET_assert (GNUNET_NO == GCT_is_loopback (t));
1894 if (CADET_Axolotl == t->enc_type)
1896 ax_msg = (struct GNUNET_CADET_AX *) cbuf;
1897 msg = &ax_msg->header;
1898 msg->size = htons (sizeof (struct GNUNET_CADET_AX) + size);
1899 msg->type = htons (GNUNET_MESSAGE_TYPE_CADET_AX);
1900 ax_msg->reserved = 0;
1901 esize = t_ax_encrypt (t, &ax_msg[1], message, size);
1902 ax_msg->Ns = htonl (t->ax->Ns++);
1903 ax_msg->PNs = htonl (t->ax->PNs);
1904 GNUNET_CRYPTO_ecdhe_key_get_public (t->ax->DHRs, &ax_msg->DHRs);
1905 t_h_encrypt (t, ax_msg);
1906 t_hmac (&ax_msg->Ns, AX_HEADER_SIZE + esize, 0, &t->ax->HKs, &ax_msg->hmac);
1910 otr_msg = (struct GNUNET_CADET_Encrypted *) cbuf;
1911 msg = &otr_msg->header;
1912 iv = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX);
1914 esize = t_encrypt (t, &otr_msg[1], message, size, iv, GNUNET_NO);
1915 t_hmac (&otr_msg[1], size, iv, select_key (t), &otr_msg->hmac);
1916 msg->size = htons (sizeof (struct GNUNET_CADET_Encrypted) + size);
1917 msg->type = htons (GNUNET_MESSAGE_TYPE_CADET_ENCRYPTED);
1918 otr_msg->ttl = htonl (default_ttl);
1920 GNUNET_assert (esize == size);
1923 c = tunnel_get_connection (t);
1926 /* Why is tunnel 'ready'? Should have been queued! */
1927 if (NULL != t->destroy_task)
1930 GCT_debug (t, GNUNET_ERROR_TYPE_WARNING);
1932 return NULL; /* Drop... */
1936 type = ntohs (message->type);
1939 case GNUNET_MESSAGE_TYPE_CADET_DATA:
1940 case GNUNET_MESSAGE_TYPE_CADET_DATA_ACK:
1941 if (GNUNET_MESSAGE_TYPE_CADET_DATA == type)
1942 mid = ntohl (((struct GNUNET_CADET_Data *) message)->mid);
1944 mid = ntohl (((struct GNUNET_CADET_DataACK *) message)->mid);
1946 case GNUNET_MESSAGE_TYPE_CADET_KEEPALIVE:
1947 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_CREATE:
1948 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_DESTROY:
1949 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_ACK:
1950 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_NACK:
1954 LOG (GNUNET_ERROR_TYPE_ERROR, "type %s not valid\n", GC_m2s (type));
1956 LOG (GNUNET_ERROR_TYPE_DEBUG, "type %s\n", GC_m2s (type));
1958 fwd = GCC_is_origin (c, GNUNET_YES);
1962 GNUNET_break (NULL == GCC_send_prebuilt_message (msg, type, mid, c, fwd,
1963 force, NULL, NULL));
1966 if (NULL == existing_q)
1968 tq = GNUNET_new (struct CadetTunnelQueue); /* FIXME valgrind: leak*/
1975 tq->cq = GCC_send_prebuilt_message (msg, type, mid, c, fwd, force,
1976 &tun_message_sent, tq);
1977 GNUNET_assert (NULL != tq->cq);
1979 tq->cont_cls = cont_cls;
1986 * Send all cached messages that we can, tunnel is online.
1988 * @param t Tunnel that holds the messages. Cannot be loopback.
1991 send_queued_data (struct CadetTunnel *t)
1993 struct CadetTunnelDelayed *tqd;
1994 struct CadetTunnelDelayed *next;
1997 LOG (GNUNET_ERROR_TYPE_INFO, "Send queued data, tunnel %s\n", GCT_2s (t));
1999 if (GCT_is_loopback (t))
2005 if (GNUNET_NO == is_ready (t))
2007 LOG (GNUNET_ERROR_TYPE_WARNING, " not ready yet: %s/%s\n",
2008 estate2s (t->estate), cstate2s (t->cstate));
2012 room = GCT_get_connections_buffer (t);
2013 LOG (GNUNET_ERROR_TYPE_DEBUG, " buffer space: %u\n", room);
2014 LOG (GNUNET_ERROR_TYPE_DEBUG, " tq head: %p\n", t->tq_head);
2015 for (tqd = t->tq_head; NULL != tqd && room > 0; tqd = next)
2017 LOG (GNUNET_ERROR_TYPE_DEBUG, " sending queued data\n");
2020 send_prebuilt_message ((struct GNUNET_MessageHeader *) &tqd[1],
2021 tqd->t, NULL, GNUNET_YES,
2022 NULL != tqd->tq ? tqd->tq->cont : NULL,
2023 NULL != tqd->tq ? tqd->tq->cont_cls : NULL,
2027 LOG (GNUNET_ERROR_TYPE_DEBUG, "GCT_send_queued_data end\n", GCP_2s (t->peer));
2032 * @brief Resend the AX KX until we complete the handshake.
2034 * @param cls Closure (tunnel).
2035 * @param tc Task context.
2038 ax_kx_resend (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
2040 struct CadetTunnel *t = cls;
2042 t->rekey_task = NULL;
2044 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
2047 if (CADET_TUNNEL_KEY_OK == t->estate)
2049 /* Should have been canceled on estate change */
2054 GCT_send_ax_kx (t, GNUNET_YES);
2059 * Callback called when a queued message is sent.
2061 * @param cls Closure.
2062 * @param c Connection this message was on.
2063 * @param type Type of message sent.
2064 * @param fwd Was this a FWD going message?
2065 * @param size Size of the message.
2068 ephm_sent (void *cls,
2069 struct CadetConnection *c,
2070 struct CadetConnectionQueue *q,
2071 uint16_t type, int fwd, size_t size)
2073 struct CadetTunnel *t = cls;
2074 LOG (GNUNET_ERROR_TYPE_DEBUG, "ephemeral sent %s\n", GC_m2s (type));
2078 if (CADET_TUNNEL_KEY_OK == t->estate)
2081 if (CADET_Axolotl == t->enc_type)
2083 if (NULL != t->rekey_task)
2086 GCT_debug (t, GNUNET_ERROR_TYPE_WARNING);
2087 GNUNET_SCHEDULER_cancel (t->rekey_task);
2089 t->rekey_task = GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_SECONDS,
2096 * Callback called when a queued message is sent.
2098 * @param cls Closure.
2099 * @param c Connection this message was on.
2100 * @param type Type of message sent.
2101 * @param fwd Was this a FWD going message?
2102 * @param size Size of the message.
2105 pong_sent (void *cls,
2106 struct CadetConnection *c,
2107 struct CadetConnectionQueue *q,
2108 uint16_t type, int fwd, size_t size)
2110 struct CadetTunnel *t = cls;
2111 LOG (GNUNET_ERROR_TYPE_DEBUG, "pong_sent %s\n", GC_m2s (type));
2118 * Sends key exchange message on a tunnel, choosing the best connection.
2119 * Should not be called on loopback tunnels.
2121 * @param t Tunnel on which this message is transmitted.
2122 * @param message Message to send. Function modifies it.
2124 * @return Handle to the message in the connection queue.
2126 static struct CadetConnectionQueue *
2127 send_kx (struct CadetTunnel *t,
2128 const struct GNUNET_MessageHeader *message)
2130 struct CadetConnection *c;
2131 struct GNUNET_CADET_KX *msg;
2132 size_t size = ntohs (message->size);
2133 char cbuf[sizeof (struct GNUNET_CADET_KX) + size];
2138 LOG (GNUNET_ERROR_TYPE_DEBUG, "GMT KX on Tunnel %s\n", GCT_2s (t));
2140 /* Avoid loopback. */
2141 if (GCT_is_loopback (t))
2146 type = ntohs (message->type);
2148 /* Even if tunnel is "being destroyed", send anyway.
2149 * Could be a response to a rekey initiated by remote peer,
2150 * who is trying to create a new channel!
2153 /* Must have a connection, or be looking for one. */
2154 if (NULL == t->connection_head)
2156 LOG (GNUNET_ERROR_TYPE_DEBUG, "%s with no connection\n", GC_m2s (type));
2157 if (CADET_TUNNEL_SEARCHING != t->cstate)
2160 GCT_debug (t, GNUNET_ERROR_TYPE_ERROR);
2161 GCP_debug (t->peer, GNUNET_ERROR_TYPE_ERROR);
2166 msg = (struct GNUNET_CADET_KX *) cbuf;
2167 msg->header.type = htons (GNUNET_MESSAGE_TYPE_CADET_KX);
2168 msg->header.size = htons (sizeof (struct GNUNET_CADET_KX) + size);
2169 c = tunnel_get_connection (t);
2172 if (NULL == t->destroy_task && CADET_TUNNEL_READY == t->cstate)
2175 GCT_debug (t, GNUNET_ERROR_TYPE_ERROR);
2181 case GNUNET_MESSAGE_TYPE_CADET_KX_EPHEMERAL:
2182 case GNUNET_MESSAGE_TYPE_CADET_AX_KX:
2183 GNUNET_assert (NULL == t->ephm_h);
2186 case GNUNET_MESSAGE_TYPE_CADET_KX_PONG:
2187 GNUNET_assert (NULL == t->pong_h);
2192 LOG (GNUNET_ERROR_TYPE_DEBUG, "unkown type %s\n", GC_m2s (type));
2195 memcpy (&msg[1], message, size);
2197 fwd = GCC_is_origin (c, GNUNET_YES);
2199 return GCC_send_prebuilt_message (&msg->header, type, 0, c,
2206 * Send the ephemeral key on a tunnel.
2208 * @param t Tunnel on which to send the key.
2211 send_ephemeral (struct CadetTunnel *t)
2213 LOG (GNUNET_ERROR_TYPE_INFO, "===> EPHM for %s\n", GCT_2s (t));
2214 if (NULL != t->ephm_h)
2216 LOG (GNUNET_ERROR_TYPE_INFO, " already queued\n");
2220 otr_kx_msg.sender_status = htonl (t->estate);
2221 otr_kx_msg.iv = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX);
2222 otr_kx_msg.nonce = t->kx_ctx->challenge;
2223 LOG (GNUNET_ERROR_TYPE_DEBUG, " send nonce c %u\n", otr_kx_msg.nonce);
2224 t_encrypt (t, &otr_kx_msg.nonce, &otr_kx_msg.nonce,
2225 ping_encryption_size(), otr_kx_msg.iv, GNUNET_YES);
2226 LOG (GNUNET_ERROR_TYPE_DEBUG, " send nonce e %u\n", otr_kx_msg.nonce);
2227 t->ephm_h = send_kx (t, &otr_kx_msg.header);
2232 * Send a pong message on a tunnel.
2234 * @param t Tunnel on which to send the pong.
2235 * @param challenge Value sent in the ping that we have to send back.
2238 send_pong (struct CadetTunnel *t, uint32_t challenge)
2240 struct GNUNET_CADET_KX_Pong msg;
2242 LOG (GNUNET_ERROR_TYPE_INFO, "===> PONG for %s\n", GCT_2s (t));
2243 if (NULL != t->pong_h)
2245 LOG (GNUNET_ERROR_TYPE_INFO, " already queued\n");
2248 msg.header.size = htons (sizeof (msg));
2249 msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_KX_PONG);
2250 msg.iv = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX);
2251 msg.nonce = challenge;
2252 LOG (GNUNET_ERROR_TYPE_DEBUG, " sending %u\n", msg.nonce);
2253 t_encrypt (t, &msg.nonce, &msg.nonce,
2254 sizeof (msg.nonce), msg.iv, GNUNET_YES);
2255 LOG (GNUNET_ERROR_TYPE_DEBUG, " e sending %u\n", msg.nonce);
2257 t->pong_h = send_kx (t, &msg.header);
2262 * Initiate a rekey with the remote peer.
2264 * @param cls Closure (tunnel).
2265 * @param tc TaskContext.
2268 rekey_tunnel (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
2270 struct CadetTunnel *t = cls;
2272 t->rekey_task = NULL;
2274 LOG (GNUNET_ERROR_TYPE_INFO, "Re-key Tunnel %s\n", GCT_2s (t));
2275 if (NULL != tc && 0 != (GNUNET_SCHEDULER_REASON_SHUTDOWN & tc->reason))
2278 GNUNET_assert (NULL != t->kx_ctx);
2279 struct GNUNET_TIME_Relative duration;
2281 duration = GNUNET_TIME_absolute_get_duration (t->kx_ctx->rekey_start_time);
2282 LOG (GNUNET_ERROR_TYPE_DEBUG, " kx started %s ago\n",
2283 GNUNET_STRINGS_relative_time_to_string (duration, GNUNET_YES));
2285 // FIXME make duration of old keys configurable
2286 if (duration.rel_value_us >= GNUNET_TIME_UNIT_MINUTES.rel_value_us)
2288 LOG (GNUNET_ERROR_TYPE_DEBUG, " deleting old keys\n");
2289 memset (&t->kx_ctx->d_key_old, 0, sizeof (t->kx_ctx->d_key_old));
2290 memset (&t->kx_ctx->e_key_old, 0, sizeof (t->kx_ctx->e_key_old));
2297 case CADET_TUNNEL_KEY_UNINITIALIZED:
2298 GCT_change_estate (t, CADET_TUNNEL_KEY_SENT);
2301 case CADET_TUNNEL_KEY_SENT:
2304 case CADET_TUNNEL_KEY_OK:
2306 * - state should have changed during rekey_iterator
2307 * - task should have been canceled at pong_handle
2310 GCT_change_estate (t, CADET_TUNNEL_KEY_REKEY);
2313 case CADET_TUNNEL_KEY_PING:
2314 case CADET_TUNNEL_KEY_REKEY:
2318 LOG (GNUNET_ERROR_TYPE_DEBUG, "Unexpected state %u\n", t->estate);
2321 // FIXME exponential backoff
2322 struct GNUNET_TIME_Relative delay;
2324 delay = GNUNET_TIME_relative_divide (rekey_period, 16);
2325 delay = GNUNET_TIME_relative_min (delay, REKEY_WAIT);
2326 LOG (GNUNET_ERROR_TYPE_DEBUG, " next call in %s\n",
2327 GNUNET_STRINGS_relative_time_to_string (delay, GNUNET_YES));
2328 t->rekey_task = GNUNET_SCHEDULER_add_delayed (delay, &rekey_tunnel, t);
2333 * Our ephemeral key has changed, create new session key on all tunnels.
2335 * Each tunnel will start the Key Exchange with a random delay between
2336 * 0 and number_of_tunnels*100 milliseconds, so there are 10 key exchanges
2337 * per second, on average.
2339 * @param cls Closure (size of the hashmap).
2340 * @param key Current public key.
2341 * @param value Value in the hash map (tunnel).
2343 * @return #GNUNET_YES, so we should continue to iterate,
2346 rekey_iterator (void *cls,
2347 const struct GNUNET_PeerIdentity *key,
2350 struct CadetTunnel *t = value;
2351 struct GNUNET_TIME_Relative delay;
2352 long n = (long) cls;
2355 if (NULL != t->rekey_task)
2358 if (GNUNET_YES == GCT_is_loopback (t))
2361 if (CADET_OTR != t->enc_type)
2364 r = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK, (uint32_t) n * 100);
2365 delay = GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MILLISECONDS, r);
2366 t->rekey_task = GNUNET_SCHEDULER_add_delayed (delay, &rekey_tunnel, t);
2367 if (GNUNET_OK == create_kx_ctx (t))
2368 GCT_change_estate (t, CADET_TUNNEL_KEY_REKEY);
2380 * Create a new ephemeral key and key message, schedule next rekeying.
2382 * @param cls Closure (unused).
2383 * @param tc TaskContext.
2386 global_otr_rekey (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
2388 struct GNUNET_TIME_Absolute time;
2393 if (0 != (GNUNET_SCHEDULER_REASON_SHUTDOWN & tc->reason))
2396 GNUNET_free_non_null (otr_ephemeral_key);
2397 otr_ephemeral_key = GNUNET_CRYPTO_ecdhe_key_create ();
2399 time = GNUNET_TIME_absolute_get ();
2400 otr_kx_msg.creation_time = GNUNET_TIME_absolute_hton (time);
2401 time = GNUNET_TIME_absolute_add (time, rekey_period);
2402 time = GNUNET_TIME_absolute_add (time, GNUNET_TIME_UNIT_MINUTES);
2403 otr_kx_msg.expiration_time = GNUNET_TIME_absolute_hton (time);
2404 GNUNET_CRYPTO_ecdhe_key_get_public (otr_ephemeral_key, &otr_kx_msg.ephemeral_key);
2405 LOG (GNUNET_ERROR_TYPE_INFO, "GLOBAL OTR RE-KEY, NEW EPHM: %s\n",
2406 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &otr_kx_msg.ephemeral_key));
2408 GNUNET_assert (GNUNET_OK ==
2409 GNUNET_CRYPTO_eddsa_sign (id_key,
2410 &otr_kx_msg.purpose,
2411 &otr_kx_msg.signature));
2413 n = (long) GNUNET_CONTAINER_multipeermap_size (tunnels);
2414 GNUNET_CONTAINER_multipeermap_iterate (tunnels, &rekey_iterator, (void *) n);
2416 rekey_task = GNUNET_SCHEDULER_add_delayed (rekey_period,
2417 &global_otr_rekey, NULL);
2422 * Called only on shutdown, destroy every tunnel.
2424 * @param cls Closure (unused).
2425 * @param key Current public key.
2426 * @param value Value in the hash map (tunnel).
2428 * @return #GNUNET_YES, so we should continue to iterate,
2431 destroy_iterator (void *cls,
2432 const struct GNUNET_PeerIdentity *key,
2435 struct CadetTunnel *t = value;
2437 LOG (GNUNET_ERROR_TYPE_DEBUG, "GCT_shutdown destroying tunnel at %p\n", t);
2444 * Notify remote peer that we don't know a channel he is talking about,
2445 * probably CHANNEL_DESTROY was missed.
2447 * @param t Tunnel on which to notify.
2448 * @param gid ID of the channel.
2451 send_channel_destroy (struct CadetTunnel *t, unsigned int gid)
2453 struct GNUNET_CADET_ChannelManage msg;
2455 msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_CHANNEL_DESTROY);
2456 msg.header.size = htons (sizeof (msg));
2457 msg.chid = htonl (gid);
2459 LOG (GNUNET_ERROR_TYPE_DEBUG,
2460 "WARNING destroying unknown channel %u on tunnel %s\n",
2462 send_prebuilt_message (&msg.header, t, NULL, GNUNET_YES, NULL, NULL, NULL);
2467 * Demultiplex data per channel and call appropriate channel handler.
2469 * @param t Tunnel on which the data came.
2470 * @param msg Data message.
2471 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
2472 * #GNUNET_YES if message is FWD on the respective channel (loopback)
2473 * #GNUNET_NO if message is BCK on the respective channel (loopback)
2474 * #GNUNET_SYSERR if message on a one-ended channel (remote)
2477 handle_data (struct CadetTunnel *t,
2478 const struct GNUNET_CADET_Data *msg,
2481 struct CadetChannel *ch;
2487 size = ntohs (msg->header.size);
2489 sizeof (struct GNUNET_CADET_Data) +
2490 sizeof (struct GNUNET_MessageHeader))
2495 type = ntohs (msg[1].header.type);
2496 LOG (GNUNET_ERROR_TYPE_DEBUG, " payload of type %s\n", GC_m2s (type));
2497 sprintf (buf, "# received payload of type %hu", type);
2498 GNUNET_STATISTICS_update (stats, buf, 1, GNUNET_NO);
2502 ch = GCT_get_channel (t, ntohl (msg->chid));
2505 GNUNET_STATISTICS_update (stats, "# data on unknown channel",
2507 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel 0x%X unknown\n",
2509 send_channel_destroy (t, ntohl (msg->chid));
2513 GCCH_handle_data (ch, msg, fwd);
2518 * Demultiplex data ACKs per channel and update appropriate channel buffer info.
2520 * @param t Tunnel on which the DATA ACK came.
2521 * @param msg DATA ACK message.
2522 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
2523 * #GNUNET_YES if message is FWD on the respective channel (loopback)
2524 * #GNUNET_NO if message is BCK on the respective channel (loopback)
2525 * #GNUNET_SYSERR if message on a one-ended channel (remote)
2528 handle_data_ack (struct CadetTunnel *t,
2529 const struct GNUNET_CADET_DataACK *msg,
2532 struct CadetChannel *ch;
2536 size = ntohs (msg->header.size);
2537 if (size != sizeof (struct GNUNET_CADET_DataACK))
2544 ch = GCT_get_channel (t, ntohl (msg->chid));
2547 GNUNET_STATISTICS_update (stats, "# data ack on unknown channel",
2549 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel %u unknown\n",
2554 GCCH_handle_data_ack (ch, msg, fwd);
2559 * Handle channel create.
2561 * @param t Tunnel on which the data came.
2562 * @param msg Data message.
2565 handle_ch_create (struct CadetTunnel *t,
2566 const struct GNUNET_CADET_ChannelCreate *msg)
2568 struct CadetChannel *ch;
2572 size = ntohs (msg->header.size);
2573 if (size != sizeof (struct GNUNET_CADET_ChannelCreate))
2580 ch = GCT_get_channel (t, ntohl (msg->chid));
2581 if (NULL != ch && ! GCT_is_loopback (t))
2583 /* Probably a retransmission, safe to ignore */
2584 LOG (GNUNET_ERROR_TYPE_DEBUG, " already exists...\n");
2586 ch = GCCH_handle_create (t, msg);
2588 GCT_add_channel (t, ch);
2594 * Handle channel NACK: check correctness and call channel handler for NACKs.
2596 * @param t Tunnel on which the NACK came.
2597 * @param msg NACK message.
2600 handle_ch_nack (struct CadetTunnel *t,
2601 const struct GNUNET_CADET_ChannelManage *msg)
2603 struct CadetChannel *ch;
2607 size = ntohs (msg->header.size);
2608 if (size != sizeof (struct GNUNET_CADET_ChannelManage))
2615 ch = GCT_get_channel (t, ntohl (msg->chid));
2618 GNUNET_STATISTICS_update (stats, "# channel NACK on unknown channel",
2620 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel %u unknown\n",
2625 GCCH_handle_nack (ch);
2630 * Handle a CHANNEL ACK (SYNACK/ACK).
2632 * @param t Tunnel on which the CHANNEL ACK came.
2633 * @param msg CHANNEL ACK message.
2634 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
2635 * #GNUNET_YES if message is FWD on the respective channel (loopback)
2636 * #GNUNET_NO if message is BCK on the respective channel (loopback)
2637 * #GNUNET_SYSERR if message on a one-ended channel (remote)
2640 handle_ch_ack (struct CadetTunnel *t,
2641 const struct GNUNET_CADET_ChannelManage *msg,
2644 struct CadetChannel *ch;
2648 size = ntohs (msg->header.size);
2649 if (size != sizeof (struct GNUNET_CADET_ChannelManage))
2656 ch = GCT_get_channel (t, ntohl (msg->chid));
2659 GNUNET_STATISTICS_update (stats, "# channel ack on unknown channel",
2661 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel %u unknown\n",
2666 GCCH_handle_ack (ch, msg, fwd);
2671 * Handle a channel destruction message.
2673 * @param t Tunnel on which the message came.
2674 * @param msg Channel destroy message.
2675 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
2676 * #GNUNET_YES if message is FWD on the respective channel (loopback)
2677 * #GNUNET_NO if message is BCK on the respective channel (loopback)
2678 * #GNUNET_SYSERR if message on a one-ended channel (remote)
2681 handle_ch_destroy (struct CadetTunnel *t,
2682 const struct GNUNET_CADET_ChannelManage *msg,
2685 struct CadetChannel *ch;
2689 size = ntohs (msg->header.size);
2690 if (size != sizeof (struct GNUNET_CADET_ChannelManage))
2697 ch = GCT_get_channel (t, ntohl (msg->chid));
2700 /* Probably a retransmission, safe to ignore */
2704 GCCH_handle_destroy (ch, msg, fwd);
2709 * Free Axolotl data.
2714 destroy_ax (struct CadetTunnel *t)
2719 GNUNET_free_non_null (t->ax->DHRs);
2720 GNUNET_free_non_null (t->ax->kx_0);
2721 while (NULL != t->ax->skipped_head)
2722 delete_skipped_key (t, t->ax->skipped_head);
2723 GNUNET_assert (0 == t->ax->skipped);
2725 GNUNET_free (t->ax);
2728 if (NULL != t->rekey_task)
2730 GNUNET_SCHEDULER_cancel (t->rekey_task);
2731 t->rekey_task = NULL;
2733 if (NULL != t->ephm_h)
2735 GCC_cancel (t->ephm_h);
2742 * The peer's ephemeral key has changed: update the symmetrical keys.
2744 * @param t Tunnel this message came on.
2745 * @param msg Key eXchange message.
2748 handle_ephemeral (struct CadetTunnel *t,
2749 const struct GNUNET_CADET_KX_Ephemeral *msg)
2751 LOG (GNUNET_ERROR_TYPE_INFO, "<=== EPHM for %s\n", GCT_2s (t));
2753 /* Some old versions are still around, don't log as error. */
2754 if (GNUNET_OK != check_ephemeral (t, msg))
2757 /* If we get a proper OTR-style ephemeral, fallback to old crypto. */
2761 t->enc_type = CADET_OTR;
2762 if (NULL != t->rekey_task)
2763 GNUNET_SCHEDULER_cancel (t->rekey_task);
2764 if (GNUNET_OK != create_kx_ctx (t))
2770 rekey_tunnel (t, NULL);
2771 GNUNET_STATISTICS_update (stats, "# otr-downgrades", -1, GNUNET_NO);
2775 * If the key is different from what we know, derive the new E/D keys.
2776 * Else destroy the rekey ctx (duplicate EPHM after successful KX).
2778 if (0 != memcmp (&t->peers_ephemeral_key, &msg->ephemeral_key,
2779 sizeof (msg->ephemeral_key)))
2781 #if DUMP_KEYS_TO_STDERR
2782 LOG (GNUNET_ERROR_TYPE_INFO, "OLD: %s\n",
2783 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &t->peers_ephemeral_key));
2784 LOG (GNUNET_ERROR_TYPE_INFO, "NEW: %s\n",
2785 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &msg->ephemeral_key));
2787 t->peers_ephemeral_key = msg->ephemeral_key;
2789 if (GNUNET_OK != create_kx_ctx (t))
2796 if (CADET_TUNNEL_KEY_OK == t->estate)
2798 GCT_change_estate (t, CADET_TUNNEL_KEY_REKEY);
2800 if (NULL != t->rekey_task)
2801 GNUNET_SCHEDULER_cancel (t->rekey_task);
2802 t->rekey_task = GNUNET_SCHEDULER_add_now (rekey_tunnel, t);
2804 if (CADET_TUNNEL_KEY_SENT == t->estate)
2806 LOG (GNUNET_ERROR_TYPE_DEBUG, " our key was sent, sending challenge\n");
2808 GCT_change_estate (t, CADET_TUNNEL_KEY_PING);
2811 if (CADET_TUNNEL_KEY_UNINITIALIZED != ntohl(msg->sender_status))
2815 LOG (GNUNET_ERROR_TYPE_DEBUG, " recv nonce e %u\n", msg->nonce);
2816 t_decrypt (t, &nonce, &msg->nonce, ping_encryption_size (), msg->iv);
2817 LOG (GNUNET_ERROR_TYPE_DEBUG, " recv nonce c %u\n", nonce);
2818 send_pong (t, nonce);
2824 * Peer has answer to our challenge.
2825 * If answer is successful, consider the key exchange finished and clean
2826 * up all related state.
2828 * @param t Tunnel this message came on.
2829 * @param msg Key eXchange Pong message.
2832 handle_pong (struct CadetTunnel *t,
2833 const struct GNUNET_CADET_KX_Pong *msg)
2837 LOG (GNUNET_ERROR_TYPE_INFO, "<=== PONG for %s\n", GCT_2s (t));
2838 if (NULL == t->rekey_task)
2840 GNUNET_STATISTICS_update (stats, "# duplicate PONG messages", 1, GNUNET_NO);
2843 if (NULL == t->kx_ctx)
2845 GNUNET_STATISTICS_update (stats, "# stray PONG messages", 1, GNUNET_NO);
2849 t_decrypt (t, &challenge, &msg->nonce, sizeof (uint32_t), msg->iv);
2850 if (challenge != t->kx_ctx->challenge)
2852 LOG (GNUNET_ERROR_TYPE_WARNING, "Wrong PONG challenge on %s\n", GCT_2s (t));
2853 LOG (GNUNET_ERROR_TYPE_DEBUG, "PONG: %u (e: %u). Expected: %u.\n",
2854 challenge, msg->nonce, t->kx_ctx->challenge);
2858 GNUNET_SCHEDULER_cancel (t->rekey_task);
2859 t->rekey_task = NULL;
2861 /* Don't free the old keys right away, but after a delay.
2862 * Rationale: the KX could have happened over a very fast connection,
2863 * with payload traffic still signed with the old key stuck in a slower
2865 * Don't keep the keys longer than 1/4 the rekey period, and no longer than
2869 GCT_change_estate (t, CADET_TUNNEL_KEY_OK);
2874 * Handle Axolotl handshake.
2876 * @param t Tunnel this message came on.
2877 * @param msg Key eXchange Pong message.
2880 handle_kx_ax (struct CadetTunnel *t, const struct GNUNET_CADET_AX_KX *msg)
2882 struct CadetTunnelAxolotl *ax;
2883 struct GNUNET_HashCode key_material[3];
2884 struct GNUNET_CRYPTO_SymmetricSessionKey keys[5];
2885 const char salt[] = "CADET Axolotl salt";
2886 const struct GNUNET_PeerIdentity *pid;
2889 LOG (GNUNET_ERROR_TYPE_INFO, "<=== AX_KX on %s\n", GCT_2s (t));
2893 /* Something is wrong if ax is NULL. Whose fault it is? */
2894 GNUNET_break_op (CADET_OTR == t->enc_type);
2895 GNUNET_break (CADET_Axolotl == t->enc_type);
2900 pid = GCT_get_destination (t);
2901 if (0 > GNUNET_CRYPTO_cmp_peer_identity (&my_full_id, pid))
2902 am_I_alice = GNUNET_YES;
2903 else if (0 < GNUNET_CRYPTO_cmp_peer_identity (&my_full_id, pid))
2904 am_I_alice = GNUNET_NO;
2907 GNUNET_break_op (0);
2911 if (0 != (GNUNET_CADET_AX_KX_FLAG_FORCE_REPLY & ntohl (msg->flags)))
2913 if (NULL != t->rekey_task)
2915 GNUNET_SCHEDULER_cancel (t->rekey_task);
2916 t->rekey_task = NULL;
2918 GCT_send_ax_kx (t, GNUNET_NO);
2921 if (0 == memcmp (&ax->DHRr, &msg->ratchet_key, sizeof(msg->ratchet_key)))
2923 LOG (GNUNET_ERROR_TYPE_INFO, " known ratchet key, exit\n");
2927 LOG (GNUNET_ERROR_TYPE_INFO, " is Alice? %s\n", am_I_alice ? "YES" : "NO");
2929 ax->DHRr = msg->ratchet_key;
2932 if (GNUNET_YES == am_I_alice)
2934 GNUNET_CRYPTO_eddsa_ecdh (id_key, /* A */
2935 &msg->ephemeral_key, /* B0 */
2940 GNUNET_CRYPTO_ecdh_eddsa (ax->kx_0, /* B0 */
2941 &pid->public_key, /* A */
2946 if (GNUNET_YES == am_I_alice)
2948 GNUNET_CRYPTO_ecdh_eddsa (ax->kx_0, /* A0 */
2949 &pid->public_key, /* B */
2954 GNUNET_CRYPTO_eddsa_ecdh (id_key, /* A */
2955 &msg->ephemeral_key, /* B0 */
2962 /* (This is the triple-DH, we could probably safely skip this,
2963 as A0/B0 are already in the key material.) */
2964 GNUNET_CRYPTO_ecc_ecdh (ax->kx_0, /* A0 or B0 */
2965 &msg->ephemeral_key, /* B0 or A0 */
2968 #if DUMP_KEYS_TO_STDERR
2971 for (i = 0; i < 3; i++)
2972 LOG (GNUNET_ERROR_TYPE_INFO, "km[%u]: %s\n",
2973 i, GNUNET_h2s (&key_material[i]));
2978 GNUNET_CRYPTO_kdf (keys, sizeof (keys),
2979 salt, sizeof (salt),
2980 &key_material, sizeof (key_material), NULL);
2983 if (GNUNET_YES == am_I_alice)
2989 ax->ratchet_flag = GNUNET_YES;
2997 ax->ratchet_flag = GNUNET_NO;
2998 ax->ratchet_allowed = GNUNET_NO;
2999 ax->ratchet_counter = 0;
3000 ax->ratchet_expiration =
3001 GNUNET_TIME_absolute_add (GNUNET_TIME_absolute_get(), ratchet_time);
3006 GCT_change_estate (t, CADET_TUNNEL_KEY_PING);
3007 send_queued_data (t);
3012 * Demultiplex by message type and call appropriate handler for a message
3013 * towards a channel of a local tunnel.
3015 * @param t Tunnel this message came on.
3016 * @param msgh Message header.
3017 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
3018 * #GNUNET_YES if message is FWD on the respective channel (loopback)
3019 * #GNUNET_NO if message is BCK on the respective channel (loopback)
3020 * #GNUNET_SYSERR if message on a one-ended channel (remote)
3023 handle_decrypted (struct CadetTunnel *t,
3024 const struct GNUNET_MessageHeader *msgh,
3030 type = ntohs (msgh->type);
3031 LOG (GNUNET_ERROR_TYPE_INFO, "<=== %s on %s\n", GC_m2s (type), GCT_2s (t));
3032 sprintf (buf, "# received encrypted of type %hu (%s)", type, GC_m2s (type));
3033 GNUNET_STATISTICS_update (stats, buf, 1, GNUNET_NO);
3038 case GNUNET_MESSAGE_TYPE_CADET_KEEPALIVE:
3039 /* Do nothing, connection aleady got updated. */
3040 GNUNET_STATISTICS_update (stats, "# keepalives received", 1, GNUNET_NO);
3043 case GNUNET_MESSAGE_TYPE_CADET_DATA:
3044 /* Don't send hop ACK, wait for client to ACK */
3045 handle_data (t, (struct GNUNET_CADET_Data *) msgh, fwd);
3048 case GNUNET_MESSAGE_TYPE_CADET_DATA_ACK:
3049 handle_data_ack (t, (struct GNUNET_CADET_DataACK *) msgh, fwd);
3052 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_CREATE:
3053 handle_ch_create (t, (struct GNUNET_CADET_ChannelCreate *) msgh);
3056 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_NACK:
3057 handle_ch_nack (t, (struct GNUNET_CADET_ChannelManage *) msgh);
3060 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_ACK:
3061 handle_ch_ack (t, (struct GNUNET_CADET_ChannelManage *) msgh, fwd);
3064 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_DESTROY:
3065 handle_ch_destroy (t, (struct GNUNET_CADET_ChannelManage *) msgh, fwd);
3069 GNUNET_break_op (0);
3070 LOG (GNUNET_ERROR_TYPE_WARNING,
3071 "end-to-end message not known (%u)\n",
3072 ntohs (msgh->type));
3073 GCT_debug (t, GNUNET_ERROR_TYPE_WARNING);
3078 /******************************************************************************/
3079 /******************************** API ***********************************/
3080 /******************************************************************************/
3082 * Decrypt old format and demultiplex by message type. Call appropriate handler
3083 * for a message towards a channel of a local tunnel.
3085 * @param t Tunnel this message came on.
3086 * @param msg Message header.
3089 GCT_handle_encrypted (struct CadetTunnel *t,
3090 const struct GNUNET_MessageHeader *msg)
3092 uint16_t size = ntohs (msg->size);
3096 const struct GNUNET_MessageHeader *msgh;
3099 type = ntohs (msg->type);
3102 case GNUNET_MESSAGE_TYPE_CADET_ENCRYPTED:
3104 const struct GNUNET_CADET_Encrypted *emsg;
3105 size_t payload_size;
3107 GNUNET_STATISTICS_update (stats, "# received OTR", 1, GNUNET_NO);
3108 emsg = (const struct GNUNET_CADET_Encrypted *) msg;
3109 payload_size = size - sizeof (struct GNUNET_CADET_Encrypted);
3110 decrypted_size = t_decrypt_and_validate (t, cbuf, &emsg[1], payload_size,
3111 emsg->iv, &emsg->hmac);
3114 case GNUNET_MESSAGE_TYPE_CADET_AX:
3116 const struct GNUNET_CADET_AX *emsg;
3118 GNUNET_STATISTICS_update (stats, "# received Axolotl", 1, GNUNET_NO);
3119 emsg = (const struct GNUNET_CADET_AX *) msg;
3120 decrypted_size = t_ax_decrypt_and_validate (t, cbuf, emsg, size);
3124 GNUNET_break_op (0);
3128 if (-1 == decrypted_size)
3130 GNUNET_break_op (0);
3131 GNUNET_STATISTICS_update (stats, "# unable to decrypt", 1, GNUNET_NO);
3132 LOG (GNUNET_ERROR_TYPE_WARNING, "Wrong crypto on tunnel %s\n", GCT_2s (t));
3133 GCT_debug (t, GNUNET_ERROR_TYPE_WARNING);
3136 GCT_change_estate (t, CADET_TUNNEL_KEY_OK);
3138 /* FIXME: this is bad, as the structs returned from
3139 this loop may be unaligned, see util's MST for
3140 how to do this right. */
3142 while (off + sizeof (struct GNUNET_MessageHeader) < decrypted_size)
3146 msgh = (const struct GNUNET_MessageHeader *) &cbuf[off];
3147 msize = ntohs (msgh->size);
3148 if (msize < sizeof (struct GNUNET_MessageHeader))
3150 GNUNET_break_op (0);
3153 if (off + msize < decrypted_size)
3155 GNUNET_break_op (0);
3158 handle_decrypted (t, msgh, GNUNET_SYSERR);
3165 * Demultiplex an encapsulated KX message by message type.
3167 * @param t Tunnel on which the message came.
3168 * @param message Payload of KX message.
3171 GCT_handle_kx (struct CadetTunnel *t,
3172 const struct GNUNET_MessageHeader *message)
3177 type = ntohs (message->type);
3178 LOG (GNUNET_ERROR_TYPE_DEBUG, "kx message received: %s\n", GC_m2s (type));
3179 sprintf (buf, "# received KX of type %hu (%s)", type, GC_m2s (type));
3180 GNUNET_STATISTICS_update (stats, buf, 1, GNUNET_NO);
3183 case GNUNET_MESSAGE_TYPE_CADET_KX_EPHEMERAL:
3184 handle_ephemeral (t, (const struct GNUNET_CADET_KX_Ephemeral *) message);
3187 case GNUNET_MESSAGE_TYPE_CADET_KX_PONG:
3188 handle_pong (t, (const struct GNUNET_CADET_KX_Pong *) message);
3191 case GNUNET_MESSAGE_TYPE_CADET_AX_KX:
3192 handle_kx_ax (t, (const struct GNUNET_CADET_AX_KX *) message);
3196 GNUNET_break_op (0);
3197 LOG (GNUNET_ERROR_TYPE_WARNING, "kx message %s unknown\n", GC_m2s (type));
3202 * Initialize the tunnel subsystem.
3204 * @param c Configuration handle.
3205 * @param key ECC private key, to derive all other keys and do crypto.
3208 GCT_init (const struct GNUNET_CONFIGURATION_Handle *c,
3209 const struct GNUNET_CRYPTO_EddsaPrivateKey *key)
3211 int expected_overhead;
3213 LOG (GNUNET_ERROR_TYPE_DEBUG, "init\n");
3215 expected_overhead = 0;
3216 expected_overhead += sizeof (struct GNUNET_CADET_Encrypted);
3217 expected_overhead += sizeof (struct GNUNET_CADET_Data);
3218 expected_overhead += sizeof (struct GNUNET_CADET_ACK);
3219 GNUNET_assert (GNUNET_CONSTANTS_CADET_P2P_OVERHEAD == expected_overhead);
3222 GNUNET_CONFIGURATION_get_value_number (c, "CADET", "DEFAULT_TTL",
3225 GNUNET_log_config_invalid (GNUNET_ERROR_TYPE_DEBUG,
3226 "CADET", "DEFAULT_TTL", "USING DEFAULT");
3230 GNUNET_CONFIGURATION_get_value_time (c, "CADET", "REKEY_PERIOD",
3233 rekey_period = GNUNET_TIME_UNIT_DAYS;
3236 GNUNET_CONFIGURATION_get_value_number (c, "CADET", "RATCHET_MESSAGES",
3239 GNUNET_log_config_invalid (GNUNET_ERROR_TYPE_WARNING,
3240 "CADET", "RATCHET_MESSAGES", "USING DEFAULT");
3241 ratchet_messages = 64;
3244 GNUNET_CONFIGURATION_get_value_time (c, "CADET", "RATCHET_TIME",
3247 GNUNET_log_config_invalid (GNUNET_ERROR_TYPE_WARNING,
3248 "CADET", "RATCHET_TIME", "USING DEFAULT");
3249 ratchet_time = GNUNET_TIME_UNIT_HOURS;
3255 otr_kx_msg.header.size = htons (sizeof (otr_kx_msg));
3256 otr_kx_msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_KX_EPHEMERAL);
3257 otr_kx_msg.purpose.purpose = htonl (GNUNET_SIGNATURE_PURPOSE_CADET_KX);
3258 otr_kx_msg.purpose.size = htonl (ephemeral_purpose_size ());
3259 otr_kx_msg.origin_identity = my_full_id;
3260 rekey_task = GNUNET_SCHEDULER_add_now (&global_otr_rekey, NULL);
3261 tunnels = GNUNET_CONTAINER_multipeermap_create (128, GNUNET_YES);
3266 * Shut down the tunnel subsystem.
3271 if (NULL != rekey_task)
3273 GNUNET_SCHEDULER_cancel (rekey_task);
3276 GNUNET_CONTAINER_multipeermap_iterate (tunnels, &destroy_iterator, NULL);
3277 GNUNET_CONTAINER_multipeermap_destroy (tunnels);
3284 * @param destination Peer this tunnel is towards.
3286 struct CadetTunnel *
3287 GCT_new (struct CadetPeer *destination)
3289 struct CadetTunnel *t;
3291 t = GNUNET_new (struct CadetTunnel);
3293 t->peer = destination;
3296 GNUNET_CONTAINER_multipeermap_put (tunnels, GCP_get_id (destination), t,
3297 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_FAST))
3303 t->ax = GNUNET_new (struct CadetTunnelAxolotl);
3305 t->ax->kx_0 = GNUNET_CRYPTO_ecdhe_key_create ();
3311 * Change the tunnel's connection state.
3313 * @param t Tunnel whose connection state to change.
3314 * @param cstate New connection state.
3317 GCT_change_cstate (struct CadetTunnel* t, enum CadetTunnelCState cstate)
3321 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel %s cstate %s => %s\n",
3322 GCP_2s (t->peer), cstate2s (t->cstate), cstate2s (cstate));
3323 if (myid != GCP_get_short_id (t->peer) &&
3324 CADET_TUNNEL_READY != t->cstate &&
3325 CADET_TUNNEL_READY == cstate)
3328 if (CADET_TUNNEL_KEY_OK == t->estate)
3330 LOG (GNUNET_ERROR_TYPE_DEBUG, " cstate triggered send queued data\n");
3331 send_queued_data (t);
3333 else if (CADET_TUNNEL_KEY_UNINITIALIZED == t->estate)
3335 LOG (GNUNET_ERROR_TYPE_DEBUG, " cstate triggered kx\n");
3336 GCT_send_ax_kx (t, GNUNET_NO);
3340 LOG (GNUNET_ERROR_TYPE_DEBUG, "estate %s\n", estate2s (t->estate));
3345 if (CADET_TUNNEL_READY == cstate
3346 && CONNECTIONS_PER_TUNNEL <= GCT_count_connections (t))
3348 LOG (GNUNET_ERROR_TYPE_DEBUG, " cstate triggered stop dht\n");
3349 GCP_stop_search (t->peer);
3355 * Change the tunnel encryption state.
3357 * If the encryption state changes to OK, stop the rekey task.
3359 * @param t Tunnel whose encryption state to change, or NULL.
3360 * @param state New encryption state.
3363 GCT_change_estate (struct CadetTunnel* t, enum CadetTunnelEState state)
3365 enum CadetTunnelEState old;
3372 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel %s estate was %s\n",
3373 GCP_2s (t->peer), estate2s (old));
3374 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel %s estate is now %s\n",
3375 GCP_2s (t->peer), estate2s (t->estate));
3377 if (CADET_TUNNEL_KEY_OK != old && CADET_TUNNEL_KEY_OK == t->estate)
3379 if (NULL != t->rekey_task)
3381 GNUNET_SCHEDULER_cancel (t->rekey_task);
3382 t->rekey_task = NULL;
3384 /* Send queued data if tunnel is not loopback */
3385 if (myid != GCP_get_short_id (t->peer))
3386 send_queued_data (t);
3392 * @brief Check if tunnel has too many connections, and remove one if necessary.
3394 * Currently this means the newest connection, unless it is a direct one.
3395 * Implemented as a task to avoid freeing a connection that is in the middle
3396 * of being created/processed.
3398 * @param cls Closure (Tunnel to check).
3399 * @param tc Task context.
3402 trim_connections (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
3404 struct CadetTunnel *t = cls;
3406 t->trim_connections_task = NULL;
3408 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
3411 if (GCT_count_connections (t) > 2 * CONNECTIONS_PER_TUNNEL)
3413 struct CadetTConnection *iter;
3414 struct CadetTConnection *c;
3416 for (c = iter = t->connection_head; NULL != iter; iter = iter->next)
3418 if ((iter->created.abs_value_us > c->created.abs_value_us)
3419 && GNUNET_NO == GCC_is_direct (iter->c))
3426 LOG (GNUNET_ERROR_TYPE_DEBUG, "Too many connections on tunnel %s\n",
3428 LOG (GNUNET_ERROR_TYPE_DEBUG, "Destroying connection %s\n",
3441 * Add a connection to a tunnel.
3444 * @param c Connection.
3447 GCT_add_connection (struct CadetTunnel *t, struct CadetConnection *c)
3449 struct CadetTConnection *aux;
3451 GNUNET_assert (NULL != c);
3453 LOG (GNUNET_ERROR_TYPE_DEBUG, "add connection %s\n", GCC_2s (c));
3454 LOG (GNUNET_ERROR_TYPE_DEBUG, " to tunnel %s\n", GCT_2s (t));
3455 for (aux = t->connection_head; aux != NULL; aux = aux->next)
3459 aux = GNUNET_new (struct CadetTConnection);
3461 aux->created = GNUNET_TIME_absolute_get ();
3463 GNUNET_CONTAINER_DLL_insert (t->connection_head, t->connection_tail, aux);
3465 if (CADET_TUNNEL_SEARCHING == t->cstate)
3466 GCT_change_cstate (t, CADET_TUNNEL_WAITING);
3468 if (NULL != t->trim_connections_task)
3469 t->trim_connections_task = GNUNET_SCHEDULER_add_now (&trim_connections, t);
3474 * Remove a connection from a tunnel.
3477 * @param c Connection.
3480 GCT_remove_connection (struct CadetTunnel *t,
3481 struct CadetConnection *c)
3483 struct CadetTConnection *aux;
3484 struct CadetTConnection *next;
3487 LOG (GNUNET_ERROR_TYPE_DEBUG, "Removing connection %s from tunnel %s\n",
3488 GCC_2s (c), GCT_2s (t));
3489 for (aux = t->connection_head; aux != NULL; aux = next)
3494 GNUNET_CONTAINER_DLL_remove (t->connection_head, t->connection_tail, aux);
3499 conns = GCT_count_connections (t);
3501 && NULL == t->destroy_task
3502 && CADET_TUNNEL_SHUTDOWN != t->cstate
3503 && GNUNET_NO == shutting_down)
3505 if (0 == GCT_count_any_connections (t))
3506 GCT_change_cstate (t, CADET_TUNNEL_SEARCHING);
3508 GCT_change_cstate (t, CADET_TUNNEL_WAITING);
3511 /* Start new connections if needed */
3512 if (CONNECTIONS_PER_TUNNEL > conns
3513 && CADET_TUNNEL_SHUTDOWN != t->cstate
3514 && GNUNET_NO == shutting_down)
3516 LOG (GNUNET_ERROR_TYPE_DEBUG, " too few connections, getting new ones\n");
3517 GCP_connect (t->peer); /* Will change cstate to WAITING when possible */
3521 /* If not marked as ready, no change is needed */
3522 if (CADET_TUNNEL_READY != t->cstate)
3525 /* Check if any connection is ready to maintain cstate */
3526 for (aux = t->connection_head; aux != NULL; aux = aux->next)
3527 if (CADET_CONNECTION_READY == GCC_get_state (aux->c))
3533 * Add a channel to a tunnel.
3536 * @param ch Channel.
3539 GCT_add_channel (struct CadetTunnel *t, struct CadetChannel *ch)
3541 struct CadetTChannel *aux;
3543 GNUNET_assert (NULL != ch);
3545 LOG (GNUNET_ERROR_TYPE_DEBUG, "Adding channel %p to tunnel %p\n", ch, t);
3547 for (aux = t->channel_head; aux != NULL; aux = aux->next)
3549 LOG (GNUNET_ERROR_TYPE_DEBUG, " already there %p\n", aux->ch);
3554 aux = GNUNET_new (struct CadetTChannel);
3556 LOG (GNUNET_ERROR_TYPE_DEBUG, " adding %p to %p\n", aux, t->channel_head);
3557 GNUNET_CONTAINER_DLL_insert_tail (t->channel_head, t->channel_tail, aux);
3559 if (NULL != t->destroy_task)
3561 GNUNET_SCHEDULER_cancel (t->destroy_task);
3562 t->destroy_task = NULL;
3563 LOG (GNUNET_ERROR_TYPE_DEBUG, " undo destroy!\n");
3569 * Remove a channel from a tunnel.
3572 * @param ch Channel.
3575 GCT_remove_channel (struct CadetTunnel *t, struct CadetChannel *ch)
3577 struct CadetTChannel *aux;
3579 LOG (GNUNET_ERROR_TYPE_DEBUG, "Removing channel %p from tunnel %p\n", ch, t);
3580 for (aux = t->channel_head; aux != NULL; aux = aux->next)
3584 LOG (GNUNET_ERROR_TYPE_DEBUG, " found! %s\n", GCCH_2s (ch));
3585 GNUNET_CONTAINER_DLL_remove (t->channel_head, t->channel_tail, aux);
3594 * Search for a channel by global ID.
3596 * @param t Tunnel containing the channel.
3597 * @param chid Public channel number.
3599 * @return channel handler, NULL if doesn't exist
3601 struct CadetChannel *
3602 GCT_get_channel (struct CadetTunnel *t, CADET_ChannelNumber chid)
3604 struct CadetTChannel *iter;
3609 for (iter = t->channel_head; NULL != iter; iter = iter->next)
3611 if (GCCH_get_id (iter->ch) == chid)
3615 return NULL == iter ? NULL : iter->ch;
3620 * @brief Destroy a tunnel and free all resources.
3622 * Should only be called a while after the tunnel has been marked as destroyed,
3623 * in case there is a new channel added to the same peer shortly after marking
3624 * the tunnel. This way we avoid a new public key handshake.
3626 * @param cls Closure (tunnel to destroy).
3627 * @param tc Task context.
3630 delayed_destroy (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
3632 struct CadetTunnel *t = cls;
3633 struct CadetTConnection *iter;
3635 LOG (GNUNET_ERROR_TYPE_DEBUG, "delayed destroying tunnel %p\n", t);
3636 if (0 != (GNUNET_SCHEDULER_REASON_SHUTDOWN & tc->reason))
3638 LOG (GNUNET_ERROR_TYPE_WARNING,
3639 "Not destroying tunnel, due to shutdown. "
3640 "Tunnel at %p should have been freed by GCT_shutdown\n", t);
3643 t->destroy_task = NULL;
3644 t->cstate = CADET_TUNNEL_SHUTDOWN;
3646 for (iter = t->connection_head; NULL != iter; iter = iter->next)
3648 GCC_send_destroy (iter->c);
3655 * Tunnel is empty: destroy it.
3657 * Notifies all connections about the destruction.
3659 * @param t Tunnel to destroy.
3662 GCT_destroy_empty (struct CadetTunnel *t)
3664 if (GNUNET_YES == shutting_down)
3665 return; /* Will be destroyed immediately anyway */
3667 if (NULL != t->destroy_task)
3669 LOG (GNUNET_ERROR_TYPE_WARNING,
3670 "Tunnel %s is already scheduled for destruction. Tunnel debug dump:\n",
3672 GCT_debug (t, GNUNET_ERROR_TYPE_WARNING);
3674 /* should never happen, tunnel can only become empty once, and the
3675 * task identifier should be NO_TASK (cleaned when the tunnel was created
3676 * or became un-empty)
3681 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel %s empty: scheduling destruction\n",
3684 // FIXME make delay a config option
3685 t->destroy_task = GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_MINUTES,
3686 &delayed_destroy, t);
3687 LOG (GNUNET_ERROR_TYPE_DEBUG, "Scheduled destroy of %p as %p\n",
3688 t, t->destroy_task);
3693 * Destroy tunnel if empty (no more channels).
3695 * @param t Tunnel to destroy if empty.
3698 GCT_destroy_if_empty (struct CadetTunnel *t)
3700 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel %s destroy if empty\n", GCT_2s (t));
3701 if (0 < GCT_count_channels (t))
3704 GCT_destroy_empty (t);
3709 * Destroy the tunnel.
3711 * This function does not generate any warning traffic to clients or peers.
3714 * Cancel messages belonging to this tunnel queued to neighbors.
3715 * Free any allocated resources linked to the tunnel.
3717 * @param t The tunnel to destroy.
3720 GCT_destroy (struct CadetTunnel *t)
3722 struct CadetTConnection *iter_c;
3723 struct CadetTConnection *next_c;
3724 struct CadetTChannel *iter_ch;
3725 struct CadetTChannel *next_ch;
3726 unsigned int keepalives_queued;
3731 LOG (GNUNET_ERROR_TYPE_DEBUG, "destroying tunnel %s\n", GCP_2s (t->peer));
3733 GNUNET_break (GNUNET_YES ==
3734 GNUNET_CONTAINER_multipeermap_remove (tunnels,
3735 GCP_get_id (t->peer), t));
3737 for (iter_c = t->connection_head; NULL != iter_c; iter_c = next_c)
3739 next_c = iter_c->next;
3740 GCC_destroy (iter_c->c);
3742 for (iter_ch = t->channel_head; NULL != iter_ch; iter_ch = next_ch)
3744 next_ch = iter_ch->next;
3745 GCCH_destroy (iter_ch->ch);
3746 /* Should only happen on shutdown, but it's ok. */
3748 keepalives_queued = 0;
3749 while (NULL != t->tq_head)
3751 /* Should have been cleaned by destuction of channel. */
3752 struct GNUNET_MessageHeader *mh;
3755 mh = (struct GNUNET_MessageHeader *) &t->tq_head[1];
3756 type = ntohs (mh->type);
3757 if (0 == keepalives_queued && GNUNET_MESSAGE_TYPE_CADET_KEEPALIVE == type)
3759 keepalives_queued = 1;
3760 LOG (GNUNET_ERROR_TYPE_DEBUG,
3761 "one keepalive left behind on tunnel shutdown\n");
3763 else if (GNUNET_MESSAGE_TYPE_CADET_CHANNEL_DESTROY == type)
3765 LOG (GNUNET_ERROR_TYPE_WARNING,
3766 "tunnel destroyed before a CHANNEL_DESTROY was sent to peer\n");
3771 LOG (GNUNET_ERROR_TYPE_ERROR,
3772 "message left behind on tunnel shutdown: %s\n",
3775 unqueue_data (t->tq_head);
3779 if (NULL != t->destroy_task)
3781 LOG (GNUNET_ERROR_TYPE_DEBUG, "cancelling dest: %p\n", t->destroy_task);
3782 GNUNET_SCHEDULER_cancel (t->destroy_task);
3783 t->destroy_task = NULL;
3786 if (NULL != t->trim_connections_task)
3788 LOG (GNUNET_ERROR_TYPE_DEBUG, "cancelling trim: %p\n",
3789 t->trim_connections_task);
3790 GNUNET_SCHEDULER_cancel (t->trim_connections_task);
3791 t->trim_connections_task = NULL;
3794 GNUNET_STATISTICS_update (stats, "# tunnels", -1, GNUNET_NO);
3795 GCP_set_tunnel (t->peer, NULL);
3797 if (NULL != t->rekey_task)
3799 GNUNET_SCHEDULER_cancel (t->rekey_task);
3800 t->rekey_task = NULL;
3802 if (NULL != t->kx_ctx)
3804 if (NULL != t->kx_ctx->finish_task)
3805 GNUNET_SCHEDULER_cancel (t->kx_ctx->finish_task);
3806 GNUNET_free (t->kx_ctx);
3817 * @brief Use the given path for the tunnel.
3818 * Update the next and prev hops (and RCs).
3819 * (Re)start the path refresh in case the tunnel is locally owned.
3821 * @param t Tunnel to update.
3822 * @param p Path to use.
3824 * @return Connection created.
3826 struct CadetConnection *
3827 GCT_use_path (struct CadetTunnel *t, struct CadetPeerPath *p)
3829 struct CadetConnection *c;
3830 struct GNUNET_CADET_Hash cid;
3831 unsigned int own_pos;
3833 if (NULL == t || NULL == p)
3839 if (CADET_TUNNEL_SHUTDOWN == t->cstate)
3845 for (own_pos = 0; own_pos < p->length; own_pos++)
3847 if (p->peers[own_pos] == myid)
3850 if (own_pos >= p->length)
3852 GNUNET_break_op (0);
3856 GNUNET_CRYPTO_random_block (GNUNET_CRYPTO_QUALITY_NONCE, &cid, sizeof (cid));
3857 c = GCC_new (&cid, t, p, own_pos);
3860 /* Path was flawed */
3863 GCT_add_connection (t, c);
3869 * Count all created connections of a tunnel. Not necessarily ready connections!
3871 * @param t Tunnel on which to count.
3873 * @return Number of connections created, either being established or ready.
3876 GCT_count_any_connections (struct CadetTunnel *t)
3878 struct CadetTConnection *iter;
3884 for (count = 0, iter = t->connection_head; NULL != iter; iter = iter->next)
3892 * Count established (ready) connections of a tunnel.
3894 * @param t Tunnel on which to count.
3896 * @return Number of connections.
3899 GCT_count_connections (struct CadetTunnel *t)
3901 struct CadetTConnection *iter;
3907 for (count = 0, iter = t->connection_head; NULL != iter; iter = iter->next)
3908 if (CADET_CONNECTION_READY == GCC_get_state (iter->c))
3916 * Count channels of a tunnel.
3918 * @param t Tunnel on which to count.
3920 * @return Number of channels.
3923 GCT_count_channels (struct CadetTunnel *t)
3925 struct CadetTChannel *iter;
3928 for (count = 0, iter = t->channel_head;
3930 iter = iter->next, count++) /* skip */;
3937 * Get the connectivity state of a tunnel.
3941 * @return Tunnel's connectivity state.
3943 enum CadetTunnelCState
3944 GCT_get_cstate (struct CadetTunnel *t)
3949 return (enum CadetTunnelCState) -1;
3956 * Get the encryption state of a tunnel.
3960 * @return Tunnel's encryption state.
3962 enum CadetTunnelEState
3963 GCT_get_estate (struct CadetTunnel *t)
3968 return (enum CadetTunnelEState) -1;
3974 * Get the maximum buffer space for a tunnel towards a local client.
3978 * @return Biggest buffer space offered by any channel in the tunnel.
3981 GCT_get_channels_buffer (struct CadetTunnel *t)
3983 struct CadetTChannel *iter;
3984 unsigned int buffer;
3985 unsigned int ch_buf;
3987 if (NULL == t->channel_head)
3989 /* Probably getting buffer for a channel create/handshake. */
3990 LOG (GNUNET_ERROR_TYPE_DEBUG, " no channels, allow max\n");
3991 return MIN_TUNNEL_BUFFER;
3995 for (iter = t->channel_head; NULL != iter; iter = iter->next)
3997 ch_buf = get_channel_buffer (iter);
3998 if (ch_buf > buffer)
4001 if (MIN_TUNNEL_BUFFER > buffer)
4002 return MIN_TUNNEL_BUFFER;
4004 if (MAX_TUNNEL_BUFFER < buffer)
4007 return MAX_TUNNEL_BUFFER;
4014 * Get the total buffer space for a tunnel for P2P traffic.
4018 * @return Buffer space offered by all connections in the tunnel.
4021 GCT_get_connections_buffer (struct CadetTunnel *t)
4023 struct CadetTConnection *iter;
4024 unsigned int buffer;
4026 if (GNUNET_NO == is_ready (t))
4028 if (count_queued_data (t) >= 3)
4035 for (iter = t->connection_head; NULL != iter; iter = iter->next)
4037 if (GCC_get_state (iter->c) != CADET_CONNECTION_READY)
4041 buffer += get_connection_buffer (iter);
4049 * Get the tunnel's destination.
4053 * @return ID of the destination peer.
4055 const struct GNUNET_PeerIdentity *
4056 GCT_get_destination (struct CadetTunnel *t)
4058 return GCP_get_id (t->peer);
4063 * Get the tunnel's next free global channel ID.
4067 * @return GID of a channel free to use.
4070 GCT_get_next_chid (struct CadetTunnel *t)
4072 CADET_ChannelNumber chid;
4073 CADET_ChannelNumber mask;
4076 /* Set bit 30 depending on the ID relationship. Bit 31 is always 0 for GID.
4077 * If our ID is bigger or loopback tunnel, start at 0, bit 30 = 0
4078 * If peer's ID is bigger, start at 0x4... bit 30 = 1
4080 result = GNUNET_CRYPTO_cmp_peer_identity (&my_full_id, GCP_get_id (t->peer));
4085 t->next_chid |= mask;
4087 while (NULL != GCT_get_channel (t, t->next_chid))
4089 LOG (GNUNET_ERROR_TYPE_DEBUG, "Channel %u exists...\n", t->next_chid);
4090 t->next_chid = (t->next_chid + 1) & ~GNUNET_CADET_LOCAL_CHANNEL_ID_CLI;
4091 t->next_chid |= mask;
4093 chid = t->next_chid;
4094 t->next_chid = (t->next_chid + 1) & ~GNUNET_CADET_LOCAL_CHANNEL_ID_CLI;
4095 t->next_chid |= mask;
4102 * Send ACK on one or more channels due to buffer in connections.
4104 * @param t Channel which has some free buffer space.
4107 GCT_unchoke_channels (struct CadetTunnel *t)
4109 struct CadetTChannel *iter;
4110 unsigned int buffer;
4111 unsigned int channels = GCT_count_channels (t);
4112 unsigned int choked_n;
4113 struct CadetChannel *choked[channels];
4115 LOG (GNUNET_ERROR_TYPE_DEBUG, "GCT_unchoke_channels on %s\n", GCT_2s (t));
4116 LOG (GNUNET_ERROR_TYPE_DEBUG, " head: %p\n", t->channel_head);
4117 if (NULL != t->channel_head)
4118 LOG (GNUNET_ERROR_TYPE_DEBUG, " head ch: %p\n", t->channel_head->ch);
4120 if (NULL != t->tq_head)
4121 send_queued_data (t);
4123 /* Get buffer space */
4124 buffer = GCT_get_connections_buffer (t);
4130 /* Count and remember choked channels */
4132 for (iter = t->channel_head; NULL != iter; iter = iter->next)
4134 if (GNUNET_NO == get_channel_allowed (iter))
4136 choked[choked_n++] = iter->ch;
4140 /* Unchoke random channels */
4141 while (0 < buffer && 0 < choked_n)
4143 unsigned int r = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK,
4145 GCCH_allow_client (choked[r], GCCH_is_origin (choked[r], GNUNET_YES));
4148 choked[r] = choked[choked_n];
4154 * Send ACK on one or more connections due to buffer space to the client.
4156 * Iterates all connections of the tunnel and sends ACKs appropriately.
4161 GCT_send_connection_acks (struct CadetTunnel *t)
4163 struct CadetTConnection *iter;
4166 uint32_t allow_per_connection;
4168 unsigned int buffer;
4170 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel send connection ACKs on %s\n",
4179 if (CADET_TUNNEL_READY != t->cstate)
4182 buffer = GCT_get_channels_buffer (t);
4183 LOG (GNUNET_ERROR_TYPE_DEBUG, " buffer %u\n", buffer);
4185 /* Count connections, how many messages are already allowed */
4186 cs = GCT_count_connections (t);
4187 for (allowed = 0, iter = t->connection_head; NULL != iter; iter = iter->next)
4189 allowed += get_connection_allowed (iter);
4191 LOG (GNUNET_ERROR_TYPE_DEBUG, " allowed %u\n", allowed);
4193 /* Make sure there is no overflow */
4194 if (allowed > buffer)
4197 /* Authorize connections to send more data */
4198 to_allow = buffer - allowed;
4200 for (iter = t->connection_head;
4201 NULL != iter && to_allow > 0;
4204 if (CADET_CONNECTION_READY != GCC_get_state (iter->c)
4205 || get_connection_allowed (iter) > 64 / 3)
4209 allow_per_connection = to_allow/cs;
4210 to_allow -= allow_per_connection;
4212 GCC_allow (iter->c, allow_per_connection,
4213 GCC_is_origin (iter->c, GNUNET_NO));
4218 /* Since we don't allow if it's allowed to send 64/3, this can happen. */
4219 LOG (GNUNET_ERROR_TYPE_DEBUG, " reminding to_allow: %u\n", to_allow);
4225 * Cancel a previously sent message while it's in the queue.
4227 * ONLY can be called before the continuation given to the send function
4228 * is called. Once the continuation is called, the message is no longer in the
4231 * @param q Handle to the queue.
4234 GCT_cancel (struct CadetTunnelQueue *q)
4238 GNUNET_assert (NULL == q->tqd);
4240 /* tun_message_sent() will be called and free q */
4242 else if (NULL != q->tqd)
4244 unqueue_data (q->tqd);
4246 if (NULL != q->cont)
4247 q->cont (q->cont_cls, NULL, q, 0, 0);
4258 * Check if the tunnel has queued traffic.
4260 * @param t Tunnel to check.
4262 * @return #GNUNET_YES if there is queued traffic
4263 * #GNUNET_NO otherwise
4266 GCT_has_queued_traffic (struct CadetTunnel *t)
4268 return (NULL != t->tq_head) ? GNUNET_YES : GNUNET_NO;
4273 * Sends an already built message on a tunnel, encrypting it and
4274 * choosing the best connection if not provided.
4276 * @param message Message to send. Function modifies it.
4277 * @param t Tunnel on which this message is transmitted.
4278 * @param c Connection to use (autoselect if NULL).
4279 * @param force Force the tunnel to take the message (buffer overfill).
4280 * @param cont Continuation to call once message is really sent.
4281 * @param cont_cls Closure for @c cont.
4283 * @return Handle to cancel message. NULL if @c cont is NULL.
4285 struct CadetTunnelQueue *
4286 GCT_send_prebuilt_message (const struct GNUNET_MessageHeader *message,
4287 struct CadetTunnel *t, struct CadetConnection *c,
4288 int force, GCT_sent cont, void *cont_cls)
4290 return send_prebuilt_message (message, t, c, force, cont, cont_cls, NULL);
4295 * Send an Axolotl KX message.
4297 * @param t Tunnel on which to send it.
4298 * @param force_reply Force the other peer to reply with a KX message.
4301 GCT_send_ax_kx (struct CadetTunnel *t, int force_reply)
4303 struct GNUNET_CADET_AX_KX msg;
4304 enum GNUNET_CADET_AX_KX_Flags flags;
4306 LOG (GNUNET_ERROR_TYPE_INFO, "===> AX_KX for %s\n", GCT_2s (t));
4307 if (NULL != t->ephm_h)
4309 LOG (GNUNET_ERROR_TYPE_INFO, " already queued\n");
4313 msg.header.size = htons (sizeof (msg));
4314 msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_AX_KX);
4315 flags = GNUNET_CADET_AX_KX_FLAG_NONE;
4317 flags |= GNUNET_CADET_AX_KX_FLAG_FORCE_REPLY;
4318 msg.flags = htonl (flags);
4319 GNUNET_CRYPTO_ecdhe_key_get_public (t->ax->kx_0, &msg.ephemeral_key);
4320 GNUNET_CRYPTO_ecdhe_key_get_public (t->ax->DHRs, &msg.ratchet_key);
4322 t->ephm_h = send_kx (t, &msg.header);
4323 if (CADET_TUNNEL_KEY_UNINITIALIZED == t->estate)
4324 GCT_change_estate (t, CADET_TUNNEL_KEY_SENT);
4329 * Sends an already built and encrypted message on a tunnel, choosing the best
4330 * connection. Useful for re-queueing messages queued on a destroyed connection.
4332 * @param message Message to send. Function modifies it.
4333 * @param t Tunnel on which this message is transmitted.
4336 GCT_resend_message (const struct GNUNET_MessageHeader *message,
4337 struct CadetTunnel *t)
4339 struct CadetConnection *c;
4342 c = tunnel_get_connection (t);
4345 /* TODO queue in tunnel, marked as encrypted */
4346 LOG (GNUNET_ERROR_TYPE_DEBUG, "No connection available, dropping.\n");
4349 fwd = GCC_is_origin (c, GNUNET_YES);
4350 GNUNET_break (NULL == GCC_send_prebuilt_message (message, 0, 0, c, fwd,
4351 GNUNET_YES, NULL, NULL));
4356 * Is the tunnel directed towards the local peer?
4360 * @return #GNUNET_YES if it is loopback.
4363 GCT_is_loopback (const struct CadetTunnel *t)
4365 return (myid == GCP_get_short_id (t->peer));
4370 * Is the tunnel this path already?
4375 * @return #GNUNET_YES a connection uses this path.
4378 GCT_is_path_used (const struct CadetTunnel *t, const struct CadetPeerPath *p)
4380 struct CadetTConnection *iter;
4382 for (iter = t->connection_head; NULL != iter; iter = iter->next)
4383 if (path_equivalent (GCC_get_path (iter->c), p))
4391 * Get a cost of a path for a tunnel considering existing connections.
4394 * @param path Candidate path.
4396 * @return Cost of the path (path length + number of overlapping nodes)
4399 GCT_get_path_cost (const struct CadetTunnel *t,
4400 const struct CadetPeerPath *path)
4402 struct CadetTConnection *iter;
4403 const struct CadetPeerPath *aux;
4404 unsigned int overlap;
4412 GNUNET_assert (NULL != t);
4414 for (i = 0; i < path->length; i++)
4416 for (iter = t->connection_head; NULL != iter; iter = iter->next)
4418 aux = GCC_get_path (iter->c);
4422 for (j = 0; j < aux->length; j++)
4424 if (path->peers[i] == aux->peers[j])
4432 return path->length + overlap;
4437 * Get the static string for the peer this tunnel is directed.
4441 * @return Static string the destination peer's ID.
4444 GCT_2s (const struct CadetTunnel *t)
4449 return GCP_2s (t->peer);
4453 /******************************************************************************/
4454 /***************************** INFO/DEBUG *******************************/
4455 /******************************************************************************/
4458 ax_debug (const struct CadetTunnelAxolotl *ax, enum GNUNET_ErrorType level)
4460 struct GNUNET_CRYPTO_EcdhePublicKey pub;
4461 struct CadetTunnelSkippedKey *iter;
4463 LOG2 (level, "TTT RK \t %s\n",
4464 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &ax->RK));
4466 LOG2 (level, "TTT HKs \t %s\n",
4467 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &ax->HKs));
4468 LOG2 (level, "TTT HKr \t %s\n",
4469 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &ax->HKr));
4470 LOG2 (level, "TTT NHKs\t %s\n",
4471 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &ax->NHKs));
4472 LOG2 (level, "TTT NHKr\t %s\n",
4473 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &ax->NHKr));
4475 LOG2 (level, "TTT CKs \t %s\n",
4476 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &ax->CKs));
4477 LOG2 (level, "TTT CKr \t %s\n",
4478 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &ax->CKr));
4480 GNUNET_CRYPTO_ecdhe_key_get_public (ax->DHRs, &pub);
4481 LOG2 (level, "TTT DHRs\t %s\n",
4482 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &pub));
4483 LOG2 (level, "TTT DHRr\t %s\n",
4484 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &ax->DHRr));
4486 LOG2 (level, "TTT Nr\t %u\tNs\t%u\n", ax->Nr, ax->Ns);
4487 LOG2 (level, "TTT PNs\t %u\tSkipped\t%u\n", ax->PNs, ax->skipped);
4488 LOG2 (level, "TTT Ratchet\t%u\n", ax->ratchet_flag);
4490 for (iter = ax->skipped_head; NULL != iter; iter = iter->next)
4492 LOG2 (level, "TTT HK\t %s\n",
4493 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &iter->HK));
4494 LOG2 (level, "TTT MK\t %s\n",
4495 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &iter->MK));
4500 * Log all possible info about the tunnel state.
4502 * @param t Tunnel to debug.
4503 * @param level Debug level to use.
4506 GCT_debug (const struct CadetTunnel *t, enum GNUNET_ErrorType level)
4508 struct CadetTChannel *iterch;
4509 struct CadetTConnection *iterc;
4512 do_log = GNUNET_get_log_call_status (level & (~GNUNET_ERROR_TYPE_BULK),
4514 __FILE__, __FUNCTION__, __LINE__);
4518 LOG2 (level, "TTT DEBUG TUNNEL TOWARDS %s\n", GCT_2s (t));
4519 LOG2 (level, "TTT cstate %s, estate %s\n",
4520 cstate2s (t->cstate), estate2s (t->estate));
4521 LOG2 (level, "TTT kx_ctx %p, rekey_task %u, finish task %u\n",
4522 t->kx_ctx, t->rekey_task, t->kx_ctx ? t->kx_ctx->finish_task : 0);
4523 #if DUMP_KEYS_TO_STDERR
4524 if (CADET_Axolotl == t->enc_type)
4526 ax_debug (t->ax, level);
4530 LOG2 (level, "TTT my EPHM\t %s\n",
4531 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &otr_kx_msg.ephemeral_key));
4532 LOG2 (level, "TTT peers EPHM:\t %s\n",
4533 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &t->peers_ephemeral_key));
4534 LOG2 (level, "TTT ENC key:\t %s\n",
4535 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &t->e_key));
4536 LOG2 (level, "TTT DEC key:\t %s\n",
4537 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &t->d_key));
4540 LOG2 (level, "TTT OLD ENC key:\t %s\n",
4541 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &t->kx_ctx->e_key_old));
4542 LOG2 (level, "TTT OLD DEC key:\t %s\n",
4543 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &t->kx_ctx->d_key_old));
4547 LOG2 (level, "TTT tq_head %p, tq_tail %p\n", t->tq_head, t->tq_tail);
4548 LOG2 (level, "TTT destroy %p\n", t->destroy_task);
4550 LOG2 (level, "TTT channels:\n");
4551 for (iterch = t->channel_head; NULL != iterch; iterch = iterch->next)
4553 GCCH_debug (iterch->ch, level);
4556 LOG2 (level, "TTT connections:\n");
4557 for (iterc = t->connection_head; NULL != iterc; iterc = iterc->next)
4559 GCC_debug (iterc->c, level);
4562 LOG2 (level, "TTT DEBUG TUNNEL END\n");
4567 * Iterate all tunnels.
4569 * @param iter Iterator.
4570 * @param cls Closure for @c iter.
4573 GCT_iterate_all (GNUNET_CONTAINER_PeerMapIterator iter, void *cls)
4575 GNUNET_CONTAINER_multipeermap_iterate (tunnels, iter, cls);
4580 * Count all tunnels.
4582 * @return Number of tunnels to remote peers kept by this peer.
4585 GCT_count_all (void)
4587 return GNUNET_CONTAINER_multipeermap_size (tunnels);
4592 * Iterate all connections of a tunnel.
4594 * @param t Tunnel whose connections to iterate.
4595 * @param iter Iterator.
4596 * @param cls Closure for @c iter.
4599 GCT_iterate_connections (struct CadetTunnel *t, GCT_conn_iter iter, void *cls)
4601 struct CadetTConnection *ct;
4603 for (ct = t->connection_head; NULL != ct; ct = ct->next)
4609 * Iterate all channels of a tunnel.
4611 * @param t Tunnel whose channels to iterate.
4612 * @param iter Iterator.
4613 * @param cls Closure for @c iter.
4616 GCT_iterate_channels (struct CadetTunnel *t, GCT_chan_iter iter, void *cls)
4618 struct CadetTChannel *cht;
4620 for (cht = t->channel_head; NULL != cht; cht = cht->next)
4621 iter (cls, cht->ch);