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;
193 * Key number for a given HK.
200 * Axolotl data, according to https://github.com/trevp/axolotl/wiki .
202 struct CadetTunnelAxolotl
205 * A (double linked) list of stored message keys and associated header keys
206 * for "skipped" messages, i.e. messages that have not been
207 * received despite the reception of more recent messages, (head).
209 struct CadetTunnelSkippedKey *skipped_head;
212 * Skipped messages' keys DLL, tail.
214 struct CadetTunnelSkippedKey *skipped_tail;
217 * Elements in @a skipped_head <-> @a skipped_tail.
219 unsigned int skipped;
222 * 32-byte root key which gets updated by DH ratchet.
224 struct GNUNET_CRYPTO_SymmetricSessionKey RK;
227 * 32-byte header key (send).
229 struct GNUNET_CRYPTO_SymmetricSessionKey HKs;
232 * 32-byte header key (recv)
234 struct GNUNET_CRYPTO_SymmetricSessionKey HKr;
237 * 32-byte next header key (send).
239 struct GNUNET_CRYPTO_SymmetricSessionKey NHKs;
242 * 32-byte next header key (recv).
244 struct GNUNET_CRYPTO_SymmetricSessionKey NHKr;
247 * 32-byte chain keys (used for forward-secrecy updating, send).
249 struct GNUNET_CRYPTO_SymmetricSessionKey CKs;
252 * 32-byte chain keys (used for forward-secrecy updating, recv).
254 struct GNUNET_CRYPTO_SymmetricSessionKey CKr;
257 * ECDH for key exchange (A0 / B0).
259 struct GNUNET_CRYPTO_EcdhePrivateKey *kx_0;
262 * ECDH Ratchet key (send).
264 struct GNUNET_CRYPTO_EcdhePrivateKey *DHRs;
267 * ECDH Ratchet key (recv).
269 struct GNUNET_CRYPTO_EcdhePublicKey DHRr;
272 * Message number (reset to 0 with each new ratchet, next message to send).
277 * Message number (reset to 0 with each new ratchet, next message to recv).
282 * Previous message numbers (# of msgs sent under prev ratchet)
287 * True (#GNUNET_YES) if we have to send a new ratchet key in next msg.
292 * Number of messages recieved since our last ratchet advance.
293 * - If this counter = 0, we cannot send a new ratchet key in next msg.
294 * - If this counter > 0, we can (but don't yet have to) send a new key.
296 unsigned int ratchet_allowed;
299 * Number of messages recieved since our last ratchet advance.
300 * - If this counter = 0, we cannot send a new ratchet key in next msg.
301 * - If this counter > 0, we can (but don't yet have to) send a new key.
303 unsigned int ratchet_counter;
306 * When does this ratchet expire and a new one is triggered.
308 struct GNUNET_TIME_Absolute ratchet_expiration;
312 * Struct containing all information regarding a tunnel to a peer.
317 * Endpoint of the tunnel.
319 struct CadetPeer *peer;
322 * Type of encryption used in the tunnel.
324 enum CadetTunnelEncryption enc_type;
329 struct CadetTunnelAxolotl *ax;
332 * State of the tunnel connectivity.
334 enum CadetTunnelCState cstate;
337 * State of the tunnel encryption.
339 enum CadetTunnelEState estate;
342 * Key eXchange context.
344 struct CadetTunnelKXCtx *kx_ctx;
347 * Peer's ephemeral key, to recreate @c e_key and @c d_key when own ephemeral
350 struct GNUNET_CRYPTO_EcdhePublicKey peers_ephemeral_key;
353 * Encryption ("our") key. It is only "confirmed" if kx_ctx is NULL.
355 struct GNUNET_CRYPTO_SymmetricSessionKey e_key;
358 * Decryption ("their") key. It is only "confirmed" if kx_ctx is NULL.
360 struct GNUNET_CRYPTO_SymmetricSessionKey d_key;
363 * Task to start the rekey process.
365 struct GNUNET_SCHEDULER_Task * rekey_task;
368 * Paths that are actively used to reach the destination peer.
370 struct CadetTConnection *connection_head;
371 struct CadetTConnection *connection_tail;
374 * Next connection number.
379 * Channels inside this tunnel.
381 struct CadetTChannel *channel_head;
382 struct CadetTChannel *channel_tail;
385 * Channel ID for the next created channel.
387 CADET_ChannelNumber next_chid;
390 * Destroy flag: if true, destroy on last message.
392 struct GNUNET_SCHEDULER_Task * destroy_task;
395 * Queued messages, to transmit once tunnel gets connected.
397 struct CadetTunnelDelayed *tq_head;
398 struct CadetTunnelDelayed *tq_tail;
401 * Task to trim connections if too many are present.
403 struct GNUNET_SCHEDULER_Task * trim_connections_task;
406 * Ephemeral message in the queue (to avoid queueing more than one).
408 struct CadetConnectionQueue *ephm_h;
411 * Pong message in the queue.
413 struct CadetConnectionQueue *pong_h;
418 * Struct used to save messages in a non-ready tunnel to send once connected.
420 struct CadetTunnelDelayed
425 struct CadetTunnelDelayed *next;
426 struct CadetTunnelDelayed *prev;
431 struct CadetTunnel *t;
434 * Tunnel queue given to the channel to cancel request. Update on send_queued.
436 struct CadetTunnelQueue *tq;
441 /* struct GNUNET_MessageHeader *msg; */
446 * Handle for messages queued but not yet sent.
448 struct CadetTunnelQueue
451 * Connection queue handle, to cancel if necessary.
453 struct CadetConnectionQueue *cq;
456 * Handle in case message hasn't been given to a connection yet.
458 struct CadetTunnelDelayed *tqd;
461 * Continuation to call once sent.
466 * Closure for @c cont.
472 /******************************************************************************/
473 /******************************* GLOBALS ***********************************/
474 /******************************************************************************/
477 * Global handle to the statistics service.
479 extern struct GNUNET_STATISTICS_Handle *stats;
482 * Local peer own ID (memory efficient handle).
484 extern GNUNET_PEER_Id myid;
487 * Local peer own ID (full value).
489 extern struct GNUNET_PeerIdentity my_full_id;
493 * Don't try to recover tunnels if shutting down.
495 extern int shutting_down;
499 * Set of all tunnels, in order to trigger a new exchange on rekey.
500 * Indexed by peer's ID.
502 static struct GNUNET_CONTAINER_MultiPeerMap *tunnels;
505 * Default TTL for payload packets.
507 static unsigned long long default_ttl;
510 * Own Peer ID private key.
512 const static struct GNUNET_CRYPTO_EddsaPrivateKey *id_key;
515 /******************************** AXOLOTL ************************************/
518 * How many messages are needed to trigger a ratchet advance.
520 static unsigned long long ratchet_messages;
523 * How long until we trigger a ratched advance.
525 static struct GNUNET_TIME_Relative ratchet_time;
528 /******************************** OTR ***********************************/
531 * Own global OTR ephemeral private key.
533 static struct GNUNET_CRYPTO_EcdhePrivateKey *otr_ephemeral_key;
536 * Cached message used to perform a OTR key exchange.
538 static struct GNUNET_CADET_KX_Ephemeral otr_kx_msg;
541 * Task to generate a new OTR ephemeral key.
543 static struct GNUNET_SCHEDULER_Task *rekey_task;
548 static struct GNUNET_TIME_Relative rekey_period;
551 /******************************************************************************/
552 /******************************** STATIC ***********************************/
553 /******************************************************************************/
556 * Get string description for tunnel connectivity state.
558 * @param cs Tunnel state.
560 * @return String representation.
563 cstate2s (enum CadetTunnelCState cs)
569 case CADET_TUNNEL_NEW:
570 return "CADET_TUNNEL_NEW";
571 case CADET_TUNNEL_SEARCHING:
572 return "CADET_TUNNEL_SEARCHING";
573 case CADET_TUNNEL_WAITING:
574 return "CADET_TUNNEL_WAITING";
575 case CADET_TUNNEL_READY:
576 return "CADET_TUNNEL_READY";
577 case CADET_TUNNEL_SHUTDOWN:
578 return "CADET_TUNNEL_SHUTDOWN";
580 SPRINTF (buf, "%u (UNKNOWN STATE)", cs);
588 * Get string description for tunnel encryption state.
590 * @param es Tunnel state.
592 * @return String representation.
595 estate2s (enum CadetTunnelEState es)
601 case CADET_TUNNEL_KEY_UNINITIALIZED:
602 return "CADET_TUNNEL_KEY_UNINITIALIZED";
603 case CADET_TUNNEL_KEY_SENT:
604 return "CADET_TUNNEL_KEY_SENT";
605 case CADET_TUNNEL_KEY_PING:
606 return "CADET_TUNNEL_KEY_PING";
607 case CADET_TUNNEL_KEY_OK:
608 return "CADET_TUNNEL_KEY_OK";
609 case CADET_TUNNEL_KEY_REKEY:
610 return "CADET_TUNNEL_KEY_REKEY";
612 SPRINTF (buf, "%u (UNKNOWN STATE)", es);
620 * @brief Check if tunnel is ready to send traffic.
622 * Tunnel must be connected and with encryption correctly set up.
624 * @param t Tunnel to check.
626 * @return #GNUNET_YES if ready, #GNUNET_NO otherwise
629 is_ready (struct CadetTunnel *t)
635 conn_ok = CADET_TUNNEL_READY == t->cstate;
636 enc_ok = CADET_TUNNEL_KEY_OK == t->estate
637 || CADET_TUNNEL_KEY_REKEY == t->estate
638 || (CADET_TUNNEL_KEY_PING == t->estate
639 && CADET_Axolotl == t->enc_type);
640 ready = conn_ok && enc_ok;
641 ready = ready || GCT_is_loopback (t);
647 * Check if a key is invalid (NULL pointer or all 0)
649 * @param key Key to check.
651 * @return #GNUNET_YES if key is null, #GNUNET_NO if exists and is not 0.
654 is_key_null (struct GNUNET_CRYPTO_SymmetricSessionKey *key)
656 struct GNUNET_CRYPTO_SymmetricSessionKey null_key;
661 memset (&null_key, 0, sizeof (null_key));
662 if (0 == memcmp (key, &null_key, sizeof (null_key)))
669 * Ephemeral key message purpose size.
671 * @return Size of the part of the ephemeral key message that must be signed.
674 ephemeral_purpose_size (void)
676 return sizeof (struct GNUNET_CRYPTO_EccSignaturePurpose) +
677 sizeof (struct GNUNET_TIME_AbsoluteNBO) +
678 sizeof (struct GNUNET_TIME_AbsoluteNBO) +
679 sizeof (struct GNUNET_CRYPTO_EcdhePublicKey) +
680 sizeof (struct GNUNET_PeerIdentity);
685 * Size of the encrypted part of a ping message.
687 * @return Size of the encrypted part of a ping message.
690 ping_encryption_size (void)
692 return sizeof (uint32_t);
697 * Get the channel's buffer. ONLY FOR NON-LOOPBACK CHANNELS!!
699 * @param tch Tunnel's channel handle.
701 * @return Amount of messages the channel can still buffer towards the client.
704 get_channel_buffer (const struct CadetTChannel *tch)
708 /* If channel is incoming, is terminal in the FWD direction and fwd is YES */
709 fwd = GCCH_is_terminal (tch->ch, GNUNET_YES);
711 return GCCH_get_buffer (tch->ch, fwd);
716 * Get the channel's allowance status.
718 * @param tch Tunnel's channel handle.
720 * @return #GNUNET_YES if we allowed the client to send data to us.
723 get_channel_allowed (const struct CadetTChannel *tch)
727 /* If channel is outgoing, is origin in the FWD direction and fwd is YES */
728 fwd = GCCH_is_origin (tch->ch, GNUNET_YES);
730 return GCCH_get_allowed (tch->ch, fwd);
735 * Get the connection's buffer.
737 * @param tc Tunnel's connection handle.
739 * @return Amount of messages the connection can still buffer.
742 get_connection_buffer (const struct CadetTConnection *tc)
746 /* If connection is outgoing, is origin in the FWD direction and fwd is YES */
747 fwd = GCC_is_origin (tc->c, GNUNET_YES);
749 return GCC_get_buffer (tc->c, fwd);
754 * Get the connection's allowance.
756 * @param tc Tunnel's connection handle.
758 * @return Amount of messages we have allowed the next peer to send us.
761 get_connection_allowed (const struct CadetTConnection *tc)
765 /* If connection is outgoing, is origin in the FWD direction and fwd is YES */
766 fwd = GCC_is_origin (tc->c, GNUNET_YES);
768 return GCC_get_allowed (tc->c, fwd);
773 * Check that a ephemeral key message s well formed and correctly signed.
775 * @param t Tunnel on which the message came.
776 * @param msg The ephemeral key message.
778 * @return #GNUNET_OK if message is fine, #GNUNET_SYSERR otherwise.
781 check_ephemeral (struct CadetTunnel *t,
782 const struct GNUNET_CADET_KX_Ephemeral *msg)
784 /* Check message size */
785 if (ntohs (msg->header.size) != sizeof (struct GNUNET_CADET_KX_Ephemeral))
787 /* This is probably an old "MESH" version. */
788 LOG (GNUNET_ERROR_TYPE_INFO,
789 "Expected ephemeral of size %u, got %u\n",
790 sizeof (struct GNUNET_CADET_KX_Ephemeral),
791 ntohs (msg->header.size));
792 return GNUNET_SYSERR;
795 /* Check signature size */
796 if (ntohl (msg->purpose.size) != ephemeral_purpose_size ())
798 LOG (GNUNET_ERROR_TYPE_WARNING,
799 "Expected signature purpose of size %u, got %u\n",
800 ephemeral_purpose_size (),
801 ntohs (msg->purpose.size));
802 return GNUNET_SYSERR;
806 if (0 != memcmp (&msg->origin_identity,
807 GCP_get_id (t->peer),
808 sizeof (struct GNUNET_PeerIdentity)))
810 LOG (GNUNET_ERROR_TYPE_WARNING,
811 "Unexpected origin, got %s\n",
812 GNUNET_i2s (&msg->origin_identity));
813 return GNUNET_SYSERR;
816 /* Check signature */
818 GNUNET_CRYPTO_eddsa_verify (GNUNET_SIGNATURE_PURPOSE_CADET_KX,
821 &msg->origin_identity.public_key))
823 LOG (GNUNET_ERROR_TYPE_WARNING, "Signature invalid\n");
824 return GNUNET_SYSERR;
832 * Select the best key to use for encryption (send), based on KX status.
834 * Normally, return the current key. If there is a KX in progress and the old
835 * key is fresh enough, return the old key.
837 * @param t Tunnel to choose the key from.
839 * @return The optimal key to encrypt/hmac outgoing traffic.
841 static const struct GNUNET_CRYPTO_SymmetricSessionKey *
842 select_key (const struct CadetTunnel *t)
844 const struct GNUNET_CRYPTO_SymmetricSessionKey *key;
846 if (NULL != t->kx_ctx
847 && NULL == t->kx_ctx->finish_task)
849 struct GNUNET_TIME_Relative age;
851 age = GNUNET_TIME_absolute_get_duration (t->kx_ctx->rekey_start_time);
852 LOG (GNUNET_ERROR_TYPE_DEBUG,
853 " key exchange in progress, started %s ago\n",
854 GNUNET_STRINGS_relative_time_to_string (age, GNUNET_YES));
855 // FIXME make duration of old keys configurable
856 if (age.rel_value_us < GNUNET_TIME_UNIT_MINUTES.rel_value_us)
858 LOG (GNUNET_ERROR_TYPE_DEBUG, " using old key\n");
859 key = &t->kx_ctx->e_key_old;
863 LOG (GNUNET_ERROR_TYPE_DEBUG, " using new key (old key too old)\n");
869 LOG (GNUNET_ERROR_TYPE_DEBUG, " no KX: using current key\n");
877 * Create a new Axolotl ephemeral (ratchet) key.
882 new_ephemeral (struct CadetTunnel *t)
884 GNUNET_free_non_null (t->ax->DHRs);
885 t->ax->DHRs = GNUNET_CRYPTO_ecdhe_key_create();
892 * @param plaintext Content to HMAC.
893 * @param size Size of @c plaintext.
894 * @param iv Initialization vector for the message.
895 * @param key Key to use.
896 * @param hmac[out] Destination to store the HMAC.
899 t_hmac (const void *plaintext, size_t size,
900 uint32_t iv, const struct GNUNET_CRYPTO_SymmetricSessionKey *key,
901 struct GNUNET_CADET_Hash *hmac)
903 static const char ctx[] = "cadet authentication key";
904 struct GNUNET_CRYPTO_AuthKey auth_key;
905 struct GNUNET_HashCode hash;
907 #if DUMP_KEYS_TO_STDERR
908 LOG (GNUNET_ERROR_TYPE_INFO, " HMAC %u bytes with key %s\n", size,
909 GNUNET_i2s ((struct GNUNET_PeerIdentity *) key));
911 GNUNET_CRYPTO_hmac_derive_key (&auth_key, key,
916 /* Two step: CADET_Hash is only 256 bits, HashCode is 512. */
917 GNUNET_CRYPTO_hmac (&auth_key, plaintext, size, &hash);
918 memcpy (hmac, &hash, sizeof (*hmac));
923 * Encrypt daforce_newest_keyta with the tunnel key.
925 * @param t Tunnel whose key to use.
926 * @param dst Destination for the encrypted data.
927 * @param src Source of the plaintext. Can overlap with @c dst.
928 * @param size Size of the plaintext.
929 * @param iv Initialization Vector to use.
930 * @param force_newest_key Force the use of the newest key, otherwise
931 * CADET will use the old key when allowed.
932 * This can happen in the case when a KX is going on
933 * and the old one hasn't expired.
936 t_encrypt (struct CadetTunnel *t, void *dst, const void *src,
937 size_t size, uint32_t iv, int force_newest_key)
939 struct GNUNET_CRYPTO_SymmetricInitializationVector siv;
940 const struct GNUNET_CRYPTO_SymmetricSessionKey *key;
943 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_encrypt start\n");
945 key = GNUNET_YES == force_newest_key ? &t->e_key : select_key (t);
946 #if DUMP_KEYS_TO_STDERR
947 LOG (GNUNET_ERROR_TYPE_INFO, " ENC with key %s\n",
948 GNUNET_i2s ((struct GNUNET_PeerIdentity *) key));
950 GNUNET_CRYPTO_symmetric_derive_iv (&siv, key, &iv, sizeof (iv), NULL);
951 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_encrypt IV derived\n");
952 out_size = GNUNET_CRYPTO_symmetric_encrypt (src, size, key, &siv, dst);
953 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_encrypt end\n");
962 * @param key Key to use.
963 * @param hash[out] Resulting HMAC.
964 * @param source Source key material (data to HMAC).
965 * @param len Length of @a source.
968 t_ax_hmac_hash (struct GNUNET_CRYPTO_SymmetricSessionKey *key,
969 struct GNUNET_HashCode *hash,
970 void *source, unsigned int len)
972 static const char ctx[] = "axolotl HMAC-HASH";
973 struct GNUNET_CRYPTO_AuthKey auth_key;
975 GNUNET_CRYPTO_hmac_derive_key (&auth_key, key,
978 GNUNET_CRYPTO_hmac (&auth_key, source, len, hash);
983 * Derive a key from a HMAC-HASH.
985 * @param key Key to use for the HMAC.
986 * @param out Key to generate.
987 * @param source Source key material (data to HMAC).
988 * @param len Length of @a source.
991 t_hmac_derive_key (struct GNUNET_CRYPTO_SymmetricSessionKey *key,
992 struct GNUNET_CRYPTO_SymmetricSessionKey *out,
993 void *source, unsigned int len)
995 static const char ctx[] = "axolotl derive key";
996 struct GNUNET_HashCode h;
998 t_ax_hmac_hash (key, &h, source, len);
999 GNUNET_CRYPTO_kdf (out, sizeof (*out), ctx, sizeof (ctx),
1000 &h, sizeof (h), NULL);
1005 * Encrypt data with the axolotl tunnel key.
1007 * @param t Tunnel whose key to use.
1008 * @param dst Destination for the encrypted data.
1009 * @param src Source of the plaintext. Can overlap with @c dst.
1010 * @param size Size of the plaintext.
1012 * @return Size of the encrypted data.
1015 t_ax_encrypt (struct CadetTunnel *t, void *dst, const void *src, size_t size)
1017 struct GNUNET_CRYPTO_SymmetricSessionKey MK;
1018 struct GNUNET_CRYPTO_SymmetricInitializationVector iv;
1019 struct CadetTunnelAxolotl *ax;
1022 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_ax_encrypt start\n");
1026 ax->ratchet_counter++;
1027 if (GNUNET_YES == ax->ratchet_allowed
1028 && (ratchet_messages <= ax->ratchet_counter
1029 || 0 == GNUNET_TIME_absolute_get_remaining (ax->ratchet_expiration).rel_value_us))
1031 ax->ratchet_flag = GNUNET_YES;
1034 if (GNUNET_YES == ax->ratchet_flag)
1036 /* Advance ratchet */
1037 struct GNUNET_CRYPTO_SymmetricSessionKey keys[3];
1038 struct GNUNET_HashCode dh;
1039 struct GNUNET_HashCode hmac;
1040 static const char ctx[] = "axolotl ratchet";
1045 /* RK, NHKs, CKs = KDF( HMAC-HASH(RK, DH(DHRs, DHRr)) ) */
1046 GNUNET_CRYPTO_ecc_ecdh (ax->DHRs, &ax->DHRr, &dh);
1047 t_ax_hmac_hash (&ax->RK, &hmac, &dh, sizeof (dh));
1048 GNUNET_CRYPTO_kdf (keys, sizeof (keys), ctx, sizeof (ctx),
1049 &hmac, sizeof (hmac), NULL);
1056 ax->ratchet_flag = GNUNET_NO;
1057 ax->ratchet_allowed = GNUNET_NO;
1058 ax->ratchet_counter = 0;
1059 ax->ratchet_expiration =
1060 GNUNET_TIME_absolute_add (GNUNET_TIME_absolute_get(), ratchet_time);
1063 t_hmac_derive_key (&ax->CKs, &MK, "0", 1);
1064 GNUNET_CRYPTO_symmetric_derive_iv (&iv, &MK, NULL, 0, NULL);
1066 #if DUMP_KEYS_TO_STDERR
1067 LOG (GNUNET_ERROR_TYPE_INFO, " CKs: %s\n",
1068 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &ax->CKs));
1069 LOG (GNUNET_ERROR_TYPE_INFO, " AX_ENC with key %u: %s\n", ax->Ns,
1070 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &MK));
1073 out_size = GNUNET_CRYPTO_symmetric_encrypt (src, size, &MK, &iv, dst);
1075 t_hmac_derive_key (&ax->CKs, &ax->CKs, "1", 1);
1077 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_ax_encrypt end\n");
1084 * Decrypt data with the axolotl tunnel key.
1086 * @param t Tunnel whose key to use.
1087 * @param dst Destination for the decrypted data.
1088 * @param src Source of the ciphertext. Can overlap with @c dst.
1089 * @param size Size of the ciphertext.
1091 * @return Size of the decrypted data.
1094 t_ax_decrypt (struct CadetTunnel *t, void *dst, const void *src, size_t size)
1096 struct GNUNET_CRYPTO_SymmetricSessionKey MK;
1097 struct GNUNET_CRYPTO_SymmetricInitializationVector iv;
1098 struct CadetTunnelAxolotl *ax;
1101 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_ax_decrypt start\n");
1105 t_hmac_derive_key (&ax->CKr, &MK, "0", 1);
1106 GNUNET_CRYPTO_symmetric_derive_iv (&iv, &MK, NULL, 0, NULL);
1108 #if DUMP_KEYS_TO_STDERR
1109 LOG (GNUNET_ERROR_TYPE_INFO, " CKr: %s\n",
1110 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &ax->CKr));
1111 LOG (GNUNET_ERROR_TYPE_INFO, " AX_DEC with key %u: %s\n", ax->Nr,
1112 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &MK));
1115 GNUNET_assert (size >= sizeof (struct GNUNET_MessageHeader));
1116 out_size = GNUNET_CRYPTO_symmetric_decrypt (src, size, &MK, &iv, dst);
1117 GNUNET_assert (out_size == size);
1119 t_hmac_derive_key (&ax->CKr, &ax->CKr, "1", 1);
1121 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_ax_decrypt end\n");
1128 * Encrypt header with the axolotl header key.
1130 * @param t Tunnel whose key to use.
1131 * @param msg Message whose header to encrypt.
1134 t_h_encrypt (struct CadetTunnel *t, struct GNUNET_CADET_AX *msg)
1136 struct GNUNET_CRYPTO_SymmetricInitializationVector iv;
1137 struct CadetTunnelAxolotl *ax;
1140 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_h_encrypt start\n");
1143 GNUNET_CRYPTO_symmetric_derive_iv (&iv, &ax->HKs, NULL, 0, NULL);
1145 #if DUMP_KEYS_TO_STDERR
1146 LOG (GNUNET_ERROR_TYPE_INFO, " AX_ENC_H with key %s\n",
1147 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &ax->HKs));
1150 out_size = GNUNET_CRYPTO_symmetric_encrypt (&msg->Ns, AX_HEADER_SIZE,
1151 &ax->HKs, &iv, &msg->Ns);
1153 GNUNET_assert (AX_HEADER_SIZE == out_size);
1155 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_ax_encrypt end\n");
1160 * Decrypt header with the current axolotl header key.
1162 * @param t Tunnel whose current ax HK to use.
1163 * @param src Message whose header to decrypt.
1164 * @param dst Where to decrypt header to.
1167 t_h_decrypt (struct CadetTunnel *t, const struct GNUNET_CADET_AX *src,
1168 struct GNUNET_CADET_AX *dst)
1170 struct GNUNET_CRYPTO_SymmetricInitializationVector iv;
1171 struct CadetTunnelAxolotl *ax;
1174 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_h_decrypt start\n");
1177 GNUNET_CRYPTO_symmetric_derive_iv (&iv, &ax->HKr, NULL, 0, NULL);
1179 #if DUMP_KEYS_TO_STDERR
1180 LOG (GNUNET_ERROR_TYPE_INFO, " AX_DEC_H with key %s\n",
1181 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &ax->HKr));
1184 out_size = GNUNET_CRYPTO_symmetric_decrypt (&src->Ns, AX_HEADER_SIZE,
1185 &ax->HKr, &iv, &dst->Ns);
1187 GNUNET_assert (AX_HEADER_SIZE == out_size);
1189 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_h_decrypt end\n");
1194 * Decrypt and verify data with the appropriate tunnel key.
1196 * @param key Key to use.
1197 * @param dst Destination for the plaintext.
1198 * @param src Source of the encrypted data. Can overlap with @c dst.
1199 * @param size Size of the encrypted data.
1200 * @param iv Initialization Vector to use.
1202 * @return Size of the decrypted data, -1 if an error was encountered.
1205 decrypt (const struct GNUNET_CRYPTO_SymmetricSessionKey *key,
1206 void *dst, const void *src, size_t size, uint32_t iv)
1208 struct GNUNET_CRYPTO_SymmetricInitializationVector siv;
1211 LOG (GNUNET_ERROR_TYPE_DEBUG, " decrypt start\n");
1212 LOG (GNUNET_ERROR_TYPE_DEBUG, " decrypt iv\n");
1213 GNUNET_CRYPTO_symmetric_derive_iv (&siv, key, &iv, sizeof (iv), NULL);
1214 LOG (GNUNET_ERROR_TYPE_DEBUG, " decrypt iv done\n");
1215 out_size = GNUNET_CRYPTO_symmetric_decrypt (src, size, key, &siv, dst);
1216 LOG (GNUNET_ERROR_TYPE_DEBUG, " decrypt end\n");
1223 * Decrypt and verify data with the most recent tunnel key.
1225 * @param t Tunnel whose key to use.
1226 * @param dst Destination for the plaintext.
1227 * @param src Source of the encrypted data. Can overlap with @c dst.
1228 * @param size Size of the encrypted data.
1229 * @param iv Initialization Vector to use.
1231 * @return Size of the decrypted data, -1 if an error was encountered.
1234 t_decrypt (struct CadetTunnel *t, void *dst, const void *src,
1235 size_t size, uint32_t iv)
1239 #if DUMP_KEYS_TO_STDERR
1240 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_decrypt with %s\n",
1241 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &t->d_key));
1243 if (CADET_TUNNEL_KEY_UNINITIALIZED == t->estate)
1245 GNUNET_STATISTICS_update (stats, "# non decryptable data", 1, GNUNET_NO);
1246 LOG (GNUNET_ERROR_TYPE_WARNING,
1247 "got data on %s without a valid key\n",
1249 GCT_debug (t, GNUNET_ERROR_TYPE_WARNING);
1253 out_size = decrypt (&t->d_key, dst, src, size, iv);
1260 * Decrypt and verify data with the appropriate tunnel key and verify that the
1261 * data has not been altered since it was sent by the remote peer.
1263 * @param t Tunnel whose key to use.
1264 * @param dst Destination for the plaintext.
1265 * @param src Source of the encrypted data. Can overlap with @c dst.
1266 * @param size Size of the encrypted data.
1267 * @param iv Initialization Vector to use.
1268 * @param msg_hmac HMAC of the message, cannot be NULL.
1270 * @return Size of the decrypted data, -1 if an error was encountered.
1273 t_decrypt_and_validate (struct CadetTunnel *t,
1274 void *dst, const void *src,
1275 size_t size, uint32_t iv,
1276 const struct GNUNET_CADET_Hash *msg_hmac)
1278 struct GNUNET_CRYPTO_SymmetricSessionKey *key;
1279 struct GNUNET_CADET_Hash hmac;
1282 /* Try primary (newest) key */
1284 decrypted_size = decrypt (key, dst, src, size, iv);
1285 t_hmac (src, size, iv, key, &hmac);
1286 if (0 == memcmp (msg_hmac, &hmac, sizeof (hmac)))
1287 return decrypted_size;
1289 /* If no key exchange is going on, we just failed. */
1290 if (NULL == t->kx_ctx)
1292 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
1293 "Failed checksum validation on tunnel %s with no KX\n",
1295 GNUNET_STATISTICS_update (stats, "# wrong HMAC no KX", 1, GNUNET_NO);
1299 /* Try secondary key, from previous KX period. */
1300 key = &t->kx_ctx->d_key_old;
1301 decrypted_size = decrypt (key, dst, src, size, iv);
1302 t_hmac (src, size, iv, key, &hmac);
1303 if (0 == memcmp (msg_hmac, &hmac, sizeof (hmac)))
1304 return decrypted_size;
1306 /* Hail Mary, try tertiary, key, in case of parallel re-keys. */
1307 key = &t->kx_ctx->d_key_old2;
1308 decrypted_size = decrypt (key, dst, src, size, iv);
1309 t_hmac (src, size, iv, key, &hmac);
1310 if (0 == memcmp (msg_hmac, &hmac, sizeof (hmac)))
1311 return decrypted_size;
1313 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
1314 "Failed checksum validation on tunnel %s with KX\n",
1316 GNUNET_STATISTICS_update (stats, "# wrong HMAC with KX", 1, GNUNET_NO);
1322 * Decrypt and verify data with the appropriate tunnel key and verify that the
1323 * data has not been altered since it was sent by the remote peer.
1325 * @param t Tunnel whose key to use.
1326 * @param dst Destination for the plaintext.
1327 * @param src Source of the message. Can overlap with @c dst.
1328 * @param size Size of the message.
1330 * @return Size of the decrypted data, -1 if an error was encountered.
1333 try_old_ax_keys (struct CadetTunnel *t, void *dst,
1334 const struct GNUNET_CADET_AX *src, size_t size)
1336 struct CadetTunnelSkippedKey *key;
1337 struct GNUNET_CADET_Hash *hmac;
1338 struct GNUNET_CRYPTO_SymmetricInitializationVector iv;
1339 struct GNUNET_CADET_AX plaintext_header;
1344 hmac = &plaintext_header.hmac;
1345 esize = size - sizeof (struct GNUNET_CADET_AX);
1346 for (key = t->ax->skipped_head; NULL != key; key = key->next)
1348 t_hmac (&src->Ns, AX_HEADER_SIZE + esize, 0, &key->HK, hmac);
1349 if (0 == memcmp (hmac, &src->hmac, sizeof (*hmac)))
1357 #if DUMP_KEYS_TO_STDERR
1358 LOG (GNUNET_ERROR_TYPE_INFO, " AX_DEC_H with skipped key %s\n",
1359 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &key->HK));
1360 LOG (GNUNET_ERROR_TYPE_INFO, " AX_DEC with skipped key %u: %s\n",
1361 key->Kn, GNUNET_i2s ((struct GNUNET_PeerIdentity *) &key->MK));
1364 /* Should've been checked in -cadet_connection.c handle_cadet_encrypted. */
1365 GNUNET_assert (size > sizeof (struct GNUNET_CADET_AX));
1366 len = size - sizeof (struct GNUNET_CADET_AX);
1367 GNUNET_assert (len >= sizeof (struct GNUNET_MessageHeader));
1369 /* Decrypt header */
1370 GNUNET_CRYPTO_symmetric_derive_iv (&iv, &key->HK, NULL, 0, NULL);
1371 res = GNUNET_CRYPTO_symmetric_decrypt (&src->Ns, AX_HEADER_SIZE,
1372 &key->HK, &iv, &plaintext_header.Ns);
1373 GNUNET_assert (AX_HEADER_SIZE == res);
1374 LOG (GNUNET_ERROR_TYPE_INFO, " Message %u, previous: %u\n",
1375 ntohl (plaintext_header.Ns), ntohl (plaintext_header.PNs));
1377 // FIXME find correct key
1379 /* Decrypt payload */
1380 GNUNET_CRYPTO_symmetric_derive_iv (&iv, &key->MK, NULL, 0, NULL);
1381 res = GNUNET_CRYPTO_symmetric_decrypt (&src[1], len, &key->MK, &iv, dst);
1384 GNUNET_CONTAINER_DLL_remove (t->ax->skipped_head, t->ax->skipped_tail, key);
1386 GNUNET_free (key); /* GNUNET_free overwrites memory with 0xbaadf00d */
1393 * Delete a key from the list of skipped keys.
1395 * @param t Tunnel to delete from.
1396 * @param HKr Header Key to use.
1399 store_skipped_key (struct CadetTunnel *t,
1400 const struct GNUNET_CRYPTO_SymmetricSessionKey *HKr)
1402 struct CadetTunnelSkippedKey *key;
1404 key = GNUNET_new (struct CadetTunnelSkippedKey);
1405 key->timestamp = GNUNET_TIME_absolute_get ();
1406 key->Kn = t->ax->Nr;
1407 key->HK = t->ax->HKr;
1408 t_hmac_derive_key (&t->ax->CKr, &key->MK, "0", 1);
1409 #if DUMP_KEYS_TO_STDERR
1410 LOG (GNUNET_ERROR_TYPE_INFO, " storing MK for Nr %u: %s\n",
1411 key->Kn, GNUNET_i2s ((struct GNUNET_PeerIdentity *) &key->MK));
1412 LOG (GNUNET_ERROR_TYPE_INFO, " for CKr: %s\n",
1413 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &t->ax->CKr));
1415 t_hmac_derive_key (&t->ax->CKr, &t->ax->CKr, "1", 1);
1416 GNUNET_CONTAINER_DLL_insert (t->ax->skipped_head, t->ax->skipped_tail, key);
1423 * Delete a key from the list of skipped keys.
1425 * @param t Tunnel to delete from.
1426 * @param key Key to delete.
1429 delete_skipped_key (struct CadetTunnel *t, struct CadetTunnelSkippedKey *key)
1431 GNUNET_CONTAINER_DLL_remove (t->ax->skipped_head, t->ax->skipped_tail, key);
1438 * Stage skipped AX keys and calculate the message key.
1440 * Stores each HK and MK for skipped messages.
1442 * @param t Tunnel where to stage the keys.
1443 * @param HKr Header key.
1444 * @param Np Received meesage number.
1446 * @return GNUNET_OK if keys were stored.
1447 * GNUNET_SYSERR if an error ocurred (Np not expected).
1450 store_ax_keys (struct CadetTunnel *t,
1451 const struct GNUNET_CRYPTO_SymmetricSessionKey *HKr,
1457 gap = Np - t->ax->Nr;
1458 if (MAX_KEY_GAP < gap)
1460 /* Avoid DoS (forcing peer to do 2*33 chain HMAC operations) */
1461 /* TODO: start new key exchange on return */
1462 GNUNET_break_op (0);
1463 LOG (GNUNET_ERROR_TYPE_WARNING, "Got message %u, expected %u+\n",
1465 return GNUNET_SYSERR;
1469 /* Delayed message: don't store keys, flag to try old keys. */
1470 return GNUNET_SYSERR;
1473 while (t->ax->Nr < Np)
1474 store_skipped_key (t, HKr);
1476 while (t->ax->skipped > MAX_SKIPPED_KEYS)
1477 delete_skipped_key (t, t->ax->skipped_tail);
1484 * Decrypt and verify data with the appropriate tunnel key and verify that the
1485 * data has not been altered since it was sent by the remote peer.
1487 * @param t Tunnel whose key to use.
1488 * @param dst Destination for the plaintext.
1489 * @param src Source of the message. Can overlap with @c dst.
1490 * @param size Size of the message.
1492 * @return Size of the decrypted data, -1 if an error was encountered.
1495 t_ax_decrypt_and_validate (struct CadetTunnel *t, void *dst,
1496 const struct GNUNET_CADET_AX *src, size_t size)
1498 struct CadetTunnelAxolotl *ax;
1499 struct GNUNET_CADET_Hash msg_hmac;
1500 struct GNUNET_HashCode hmac;
1501 struct GNUNET_CADET_AX plaintext_header;
1508 esize = size - sizeof (struct GNUNET_CADET_AX);
1513 /* Try current HK */
1514 t_hmac (&src->Ns, AX_HEADER_SIZE + esize, 0, &ax->HKr, &msg_hmac);
1515 if (0 != memcmp (&msg_hmac, &src->hmac, sizeof (msg_hmac)))
1517 static const char ctx[] = "axolotl ratchet";
1518 struct GNUNET_CRYPTO_SymmetricSessionKey keys[3]; /* RKp, NHKp, CKp */
1519 struct GNUNET_CRYPTO_SymmetricSessionKey HK;
1520 struct GNUNET_HashCode dh;
1521 struct GNUNET_CRYPTO_EcdhePublicKey *DHRp;
1524 t_hmac (&src->Ns, AX_HEADER_SIZE + esize, 0, &ax->NHKr, &msg_hmac);
1525 if (0 != memcmp (&msg_hmac, &src->hmac, sizeof (msg_hmac)))
1527 /* Try the skipped keys, if that fails, we're out of luck. */
1528 return try_old_ax_keys (t, dst, src, size);
1530 LOG (GNUNET_ERROR_TYPE_INFO, "next HK worked\n");
1534 t_h_decrypt (t, src, &plaintext_header);
1535 Np = ntohl (plaintext_header.Ns);
1536 PNp = ntohl (plaintext_header.PNs);
1537 DHRp = &plaintext_header.DHRs;
1538 store_ax_keys (t, &HK, PNp);
1540 /* RKp, NHKp, CKp = KDF (HMAC-HASH (RK, DH (DHRp, DHRs))) */
1541 GNUNET_CRYPTO_ecc_ecdh (ax->DHRs, DHRp, &dh);
1542 t_ax_hmac_hash (&ax->RK, &hmac, &dh, sizeof (dh));
1543 GNUNET_CRYPTO_kdf (keys, sizeof (keys), ctx, sizeof (ctx),
1544 &hmac, sizeof (hmac), NULL);
1546 /* Commit "purported" keys */
1552 ax->ratchet_allowed = GNUNET_YES;
1556 LOG (GNUNET_ERROR_TYPE_DEBUG, "current HK\n");
1557 t_h_decrypt (t, src, &plaintext_header);
1558 Np = ntohl (plaintext_header.Ns);
1559 PNp = ntohl (plaintext_header.PNs);
1561 LOG (GNUNET_ERROR_TYPE_INFO, " got AX Nr %u\n", Np);
1563 if (GNUNET_OK != store_ax_keys (t, &ax->HKr, Np))
1564 /* Try the skipped keys, if that fails, we're out of luck. */
1565 return try_old_ax_keys (t, dst, src, size);
1567 osize = t_ax_decrypt (t, dst, &src[1], esize);
1572 GNUNET_break_op (0);
1581 * Create key material by doing ECDH on the local and remote ephemeral keys.
1583 * @param key_material Where to store the key material.
1584 * @param ephemeral Peer's public ephemeral key.
1586 * @return GNUNET_OK if it went fine, GNUNET_SYSERR otherwise.
1589 derive_otr_key_material (struct GNUNET_HashCode *key_material,
1590 const struct GNUNET_CRYPTO_EcdhePublicKey *ephemeral)
1593 GNUNET_CRYPTO_ecc_ecdh (otr_ephemeral_key, ephemeral, key_material))
1596 return GNUNET_SYSERR;
1603 * Create a symmetic key from the identities of both ends and the key material
1606 * @param key Destination for the generated key.
1607 * @param sender ID of the peer that will encrypt with @c key.
1608 * @param receiver ID of the peer that will decrypt with @c key.
1609 * @param key_material Hash created with ECDH with the ephemeral keys.
1612 derive_symmertic (struct GNUNET_CRYPTO_SymmetricSessionKey *key,
1613 const struct GNUNET_PeerIdentity *sender,
1614 const struct GNUNET_PeerIdentity *receiver,
1615 const struct GNUNET_HashCode *key_material)
1617 const char salt[] = "CADET kx salt";
1619 GNUNET_CRYPTO_kdf (key, sizeof (struct GNUNET_CRYPTO_SymmetricSessionKey),
1620 salt, sizeof (salt),
1621 key_material, sizeof (struct GNUNET_HashCode),
1622 sender, sizeof (struct GNUNET_PeerIdentity),
1623 receiver, sizeof (struct GNUNET_PeerIdentity),
1629 * Derive the tunnel's keys using our own and the peer's ephemeral keys.
1631 * @param t Tunnel for which to create the keys.
1633 * @return GNUNET_OK if successful, GNUNET_SYSERR otherwise.
1636 create_otr_keys (struct CadetTunnel *t)
1638 struct GNUNET_HashCode km;
1640 if (GNUNET_OK != derive_otr_key_material (&km, &t->peers_ephemeral_key))
1641 return GNUNET_SYSERR;
1642 derive_symmertic (&t->e_key, &my_full_id, GCP_get_id (t->peer), &km);
1643 derive_symmertic (&t->d_key, GCP_get_id (t->peer), &my_full_id, &km);
1644 #if DUMP_KEYS_TO_STDERR
1645 LOG (GNUNET_ERROR_TYPE_INFO, "ME: %s\n",
1646 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &otr_kx_msg.ephemeral_key));
1647 LOG (GNUNET_ERROR_TYPE_INFO, "PE: %s\n",
1648 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &t->peers_ephemeral_key));
1649 LOG (GNUNET_ERROR_TYPE_INFO, "KM: %s\n", GNUNET_h2s (&km));
1650 LOG (GNUNET_ERROR_TYPE_INFO, "EK: %s\n",
1651 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &t->e_key));
1652 LOG (GNUNET_ERROR_TYPE_INFO, "DK: %s\n",
1653 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &t->d_key));
1660 * Create a new Key eXchange context for the tunnel.
1662 * If the old keys were verified, keep them for old traffic. Create a new KX
1663 * timestamp and a new nonce.
1665 * @param t Tunnel for which to create the KX ctx.
1667 * @return GNUNET_OK if successful, GNUNET_SYSERR otherwise.
1670 create_kx_ctx (struct CadetTunnel *t)
1672 LOG (GNUNET_ERROR_TYPE_INFO, " new kx ctx for %s\n", GCT_2s (t));
1674 if (NULL != t->kx_ctx)
1676 if (NULL != t->kx_ctx->finish_task)
1678 LOG (GNUNET_ERROR_TYPE_INFO, " resetting exisiting finish task\n");
1679 GNUNET_SCHEDULER_cancel (t->kx_ctx->finish_task);
1680 t->kx_ctx->finish_task = NULL;
1685 t->kx_ctx = GNUNET_new (struct CadetTunnelKXCtx);
1686 t->kx_ctx->challenge = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE,
1690 if (CADET_TUNNEL_KEY_OK == t->estate)
1692 LOG (GNUNET_ERROR_TYPE_INFO, " backing up keys\n");
1693 t->kx_ctx->d_key_old = t->d_key;
1694 t->kx_ctx->e_key_old = t->e_key;
1697 LOG (GNUNET_ERROR_TYPE_INFO, " old keys not valid, not saving\n");
1698 t->kx_ctx->rekey_start_time = GNUNET_TIME_absolute_get ();
1699 return create_otr_keys (t);
1704 * @brief Finish the Key eXchange and destroy the old keys.
1706 * @param cls Closure (Tunnel for which to finish the KX).
1707 * @param tc Task context.
1710 finish_kx (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
1712 struct CadetTunnel *t = cls;
1714 LOG (GNUNET_ERROR_TYPE_INFO, "finish KX for %s\n", GCT_2s (t));
1716 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
1718 LOG (GNUNET_ERROR_TYPE_INFO, " shutdown\n");
1722 GNUNET_free (t->kx_ctx);
1728 * Destroy a Key eXchange context for the tunnel. This function only schedules
1729 * the destruction, the freeing of the memory (and clearing of old key material)
1730 * happens after a delay!
1732 * @param t Tunnel whose KX ctx to destroy.
1735 destroy_kx_ctx (struct CadetTunnel *t)
1737 struct GNUNET_TIME_Relative delay;
1739 if (NULL == t->kx_ctx || NULL != t->kx_ctx->finish_task)
1742 if (is_key_null (&t->kx_ctx->e_key_old))
1744 t->kx_ctx->finish_task = GNUNET_SCHEDULER_add_now (finish_kx, t);
1748 delay = GNUNET_TIME_relative_divide (rekey_period, 4);
1749 delay = GNUNET_TIME_relative_min (delay, GNUNET_TIME_UNIT_MINUTES);
1751 t->kx_ctx->finish_task = GNUNET_SCHEDULER_add_delayed (delay, finish_kx, t);
1757 * Pick a connection on which send the next data message.
1759 * @param t Tunnel on which to send the message.
1761 * @return The connection on which to send the next message.
1763 static struct CadetConnection *
1764 tunnel_get_connection (struct CadetTunnel *t)
1766 struct CadetTConnection *iter;
1767 struct CadetConnection *best;
1769 unsigned int lowest_q;
1771 LOG (GNUNET_ERROR_TYPE_DEBUG, "tunnel_get_connection %s\n", GCT_2s (t));
1773 lowest_q = UINT_MAX;
1774 for (iter = t->connection_head; NULL != iter; iter = iter->next)
1776 LOG (GNUNET_ERROR_TYPE_DEBUG, " connection %s: %u\n",
1777 GCC_2s (iter->c), GCC_get_state (iter->c));
1778 if (CADET_CONNECTION_READY == GCC_get_state (iter->c))
1780 qn = GCC_get_qn (iter->c, GCC_is_origin (iter->c, GNUNET_YES));
1781 LOG (GNUNET_ERROR_TYPE_DEBUG, " q_n %u, \n", qn);
1789 LOG (GNUNET_ERROR_TYPE_DEBUG, " selected: connection %s\n", GCC_2s (best));
1795 * Callback called when a queued message is sent.
1797 * Calculates the average time and connection packet tracking.
1799 * @param cls Closure (TunnelQueue handle).
1800 * @param c Connection this message was on.
1801 * @param q Connection queue handle (unused).
1802 * @param type Type of message sent.
1803 * @param fwd Was this a FWD going message?
1804 * @param size Size of the message.
1807 tun_message_sent (void *cls,
1808 struct CadetConnection *c,
1809 struct CadetConnectionQueue *q,
1810 uint16_t type, int fwd, size_t size)
1812 struct CadetTunnelQueue *qt = cls;
1813 struct CadetTunnel *t;
1815 LOG (GNUNET_ERROR_TYPE_DEBUG, "tun_message_sent\n");
1817 GNUNET_assert (NULL != qt->cont);
1818 t = NULL == c ? NULL : GCC_get_tunnel (c);
1819 qt->cont (qt->cont_cls, t, qt, type, size);
1825 count_queued_data (const struct CadetTunnel *t)
1827 struct CadetTunnelDelayed *iter;
1830 for (count = 0, iter = t->tq_head; iter != NULL; iter = iter->next)
1837 * Delete a queued message: either was sent or the channel was destroyed
1838 * before the tunnel's key exchange had a chance to finish.
1840 * @param tqd Delayed queue handle.
1843 unqueue_data (struct CadetTunnelDelayed *tqd)
1845 GNUNET_CONTAINER_DLL_remove (tqd->t->tq_head, tqd->t->tq_tail, tqd);
1851 * Cache a message to be sent once tunnel is online.
1853 * @param t Tunnel to hold the message.
1854 * @param msg Message itself (copy will be made).
1856 static struct CadetTunnelDelayed *
1857 queue_data (struct CadetTunnel *t, const struct GNUNET_MessageHeader *msg)
1859 struct CadetTunnelDelayed *tqd;
1860 uint16_t size = ntohs (msg->size);
1862 LOG (GNUNET_ERROR_TYPE_DEBUG, "queue data on Tunnel %s\n", GCT_2s (t));
1864 GNUNET_assert (GNUNET_NO == is_ready (t));
1866 tqd = GNUNET_malloc (sizeof (struct CadetTunnelDelayed) + size);
1869 memcpy (&tqd[1], msg, size);
1870 GNUNET_CONTAINER_DLL_insert_tail (t->tq_head, t->tq_tail, tqd);
1876 * Sends an already built message on a tunnel, encrypting it and
1877 * choosing the best connection.
1879 * @param message Message to send. Function modifies it.
1880 * @param t Tunnel on which this message is transmitted.
1881 * @param c Connection to use (autoselect if NULL).
1882 * @param force Force the tunnel to take the message (buffer overfill).
1883 * @param cont Continuation to call once message is really sent.
1884 * @param cont_cls Closure for @c cont.
1885 * @param existing_q In case this a transmission of previously queued data,
1886 * this should be TunnelQueue given to the client.
1889 * @return Handle to cancel message.
1890 * NULL if @c cont is NULL or an error happens and message is dropped.
1892 static struct CadetTunnelQueue *
1893 send_prebuilt_message (const struct GNUNET_MessageHeader *message,
1894 struct CadetTunnel *t, struct CadetConnection *c,
1895 int force, GCT_sent cont, void *cont_cls,
1896 struct CadetTunnelQueue *existing_q)
1898 struct GNUNET_MessageHeader *msg;
1899 struct GNUNET_CADET_Encrypted *otr_msg;
1900 struct GNUNET_CADET_AX *ax_msg;
1901 struct CadetTunnelQueue *tq;
1902 size_t size = ntohs (message->size);
1903 const uint16_t max_overhead = sizeof (struct GNUNET_CADET_Encrypted)
1904 + sizeof (struct GNUNET_CADET_AX);
1905 char cbuf[max_overhead + size];
1912 LOG (GNUNET_ERROR_TYPE_DEBUG, "GMT Send on Tunnel %s\n", GCT_2s (t));
1914 if (GNUNET_NO == is_ready (t))
1916 struct CadetTunnelDelayed *tqd;
1917 /* A non null existing_q indicates sending of queued data.
1918 * Should only happen after tunnel becomes ready.
1920 GNUNET_assert (NULL == existing_q);
1921 tqd = queue_data (t, message);
1924 tq = GNUNET_new (struct CadetTunnelQueue);
1928 tq->cont_cls = cont_cls;
1932 GNUNET_assert (GNUNET_NO == GCT_is_loopback (t));
1934 if (CADET_Axolotl == t->enc_type)
1936 ax_msg = (struct GNUNET_CADET_AX *) cbuf;
1937 msg = &ax_msg->header;
1938 msg->size = htons (sizeof (struct GNUNET_CADET_AX) + size);
1939 msg->type = htons (GNUNET_MESSAGE_TYPE_CADET_AX);
1940 ax_msg->reserved = 0;
1941 esize = t_ax_encrypt (t, &ax_msg[1], message, size);
1942 ax_msg->Ns = htonl (t->ax->Ns++);
1943 ax_msg->PNs = htonl (t->ax->PNs);
1944 GNUNET_CRYPTO_ecdhe_key_get_public (t->ax->DHRs, &ax_msg->DHRs);
1945 t_h_encrypt (t, ax_msg);
1946 t_hmac (&ax_msg->Ns, AX_HEADER_SIZE + esize, 0, &t->ax->HKs, &ax_msg->hmac);
1950 otr_msg = (struct GNUNET_CADET_Encrypted *) cbuf;
1951 msg = &otr_msg->header;
1952 iv = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX);
1954 esize = t_encrypt (t, &otr_msg[1], message, size, iv, GNUNET_NO);
1955 t_hmac (&otr_msg[1], size, iv, select_key (t), &otr_msg->hmac);
1956 msg->size = htons (sizeof (struct GNUNET_CADET_Encrypted) + size);
1957 msg->type = htons (GNUNET_MESSAGE_TYPE_CADET_ENCRYPTED);
1958 otr_msg->ttl = htonl (default_ttl);
1960 GNUNET_assert (esize == size);
1963 c = tunnel_get_connection (t);
1966 /* Why is tunnel 'ready'? Should have been queued! */
1967 if (NULL != t->destroy_task)
1970 GCT_debug (t, GNUNET_ERROR_TYPE_WARNING);
1972 return NULL; /* Drop... */
1976 type = ntohs (message->type);
1979 case GNUNET_MESSAGE_TYPE_CADET_DATA:
1980 case GNUNET_MESSAGE_TYPE_CADET_DATA_ACK:
1981 if (GNUNET_MESSAGE_TYPE_CADET_DATA == type)
1982 mid = ntohl (((struct GNUNET_CADET_Data *) message)->mid);
1984 mid = ntohl (((struct GNUNET_CADET_DataACK *) message)->mid);
1986 case GNUNET_MESSAGE_TYPE_CADET_KEEPALIVE:
1987 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_CREATE:
1988 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_DESTROY:
1989 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_ACK:
1990 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_NACK:
1994 LOG (GNUNET_ERROR_TYPE_ERROR, "type %s not valid\n", GC_m2s (type));
1996 LOG (GNUNET_ERROR_TYPE_DEBUG, "type %s\n", GC_m2s (type));
1998 fwd = GCC_is_origin (c, GNUNET_YES);
2002 GNUNET_break (NULL == GCC_send_prebuilt_message (msg, type, mid, c, fwd,
2003 force, NULL, NULL));
2006 if (NULL == existing_q)
2008 tq = GNUNET_new (struct CadetTunnelQueue); /* FIXME valgrind: leak*/
2015 tq->cq = GCC_send_prebuilt_message (msg, type, mid, c, fwd, force,
2016 &tun_message_sent, tq);
2017 GNUNET_assert (NULL != tq->cq);
2019 tq->cont_cls = cont_cls;
2026 * Send all cached messages that we can, tunnel is online.
2028 * @param t Tunnel that holds the messages. Cannot be loopback.
2031 send_queued_data (struct CadetTunnel *t)
2033 struct CadetTunnelDelayed *tqd;
2034 struct CadetTunnelDelayed *next;
2037 LOG (GNUNET_ERROR_TYPE_INFO, "Send queued data, tunnel %s\n", GCT_2s (t));
2039 if (GCT_is_loopback (t))
2045 if (GNUNET_NO == is_ready (t))
2047 LOG (GNUNET_ERROR_TYPE_WARNING, " not ready yet: %s/%s\n",
2048 estate2s (t->estate), cstate2s (t->cstate));
2052 room = GCT_get_connections_buffer (t);
2053 LOG (GNUNET_ERROR_TYPE_DEBUG, " buffer space: %u\n", room);
2054 LOG (GNUNET_ERROR_TYPE_DEBUG, " tq head: %p\n", t->tq_head);
2055 for (tqd = t->tq_head; NULL != tqd && room > 0; tqd = next)
2057 LOG (GNUNET_ERROR_TYPE_DEBUG, " sending queued data\n");
2060 send_prebuilt_message ((struct GNUNET_MessageHeader *) &tqd[1],
2061 tqd->t, NULL, GNUNET_YES,
2062 NULL != tqd->tq ? tqd->tq->cont : NULL,
2063 NULL != tqd->tq ? tqd->tq->cont_cls : NULL,
2067 LOG (GNUNET_ERROR_TYPE_DEBUG, "GCT_send_queued_data end\n", GCP_2s (t->peer));
2072 * @brief Resend the AX KX until we complete the handshake.
2074 * @param cls Closure (tunnel).
2075 * @param tc Task context.
2078 ax_kx_resend (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
2080 struct CadetTunnel *t = cls;
2082 t->rekey_task = NULL;
2084 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
2087 if (CADET_TUNNEL_KEY_OK == t->estate)
2089 /* Should have been canceled on estate change */
2094 GCT_send_ax_kx (t, GNUNET_YES);
2099 * Callback called when a queued message is sent.
2101 * @param cls Closure.
2102 * @param c Connection this message was on.
2103 * @param type Type of message sent.
2104 * @param fwd Was this a FWD going message?
2105 * @param size Size of the message.
2108 ephm_sent (void *cls,
2109 struct CadetConnection *c,
2110 struct CadetConnectionQueue *q,
2111 uint16_t type, int fwd, size_t size)
2113 struct CadetTunnel *t = cls;
2114 LOG (GNUNET_ERROR_TYPE_DEBUG, "ephemeral sent %s\n", GC_m2s (type));
2118 if (CADET_TUNNEL_KEY_OK == t->estate)
2121 if (CADET_Axolotl == t->enc_type)
2123 if (NULL != t->rekey_task)
2126 GCT_debug (t, GNUNET_ERROR_TYPE_WARNING);
2127 GNUNET_SCHEDULER_cancel (t->rekey_task);
2129 t->rekey_task = GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_SECONDS,
2136 * Callback called when a queued message is sent.
2138 * @param cls Closure.
2139 * @param c Connection this message was on.
2140 * @param type Type of message sent.
2141 * @param fwd Was this a FWD going message?
2142 * @param size Size of the message.
2145 pong_sent (void *cls,
2146 struct CadetConnection *c,
2147 struct CadetConnectionQueue *q,
2148 uint16_t type, int fwd, size_t size)
2150 struct CadetTunnel *t = cls;
2151 LOG (GNUNET_ERROR_TYPE_DEBUG, "pong_sent %s\n", GC_m2s (type));
2158 * Sends key exchange message on a tunnel, choosing the best connection.
2159 * Should not be called on loopback tunnels.
2161 * @param t Tunnel on which this message is transmitted.
2162 * @param message Message to send. Function modifies it.
2164 * @return Handle to the message in the connection queue.
2166 static struct CadetConnectionQueue *
2167 send_kx (struct CadetTunnel *t,
2168 const struct GNUNET_MessageHeader *message)
2170 struct CadetConnection *c;
2171 struct GNUNET_CADET_KX *msg;
2172 size_t size = ntohs (message->size);
2173 char cbuf[sizeof (struct GNUNET_CADET_KX) + size];
2178 LOG (GNUNET_ERROR_TYPE_DEBUG, "GMT KX on Tunnel %s\n", GCT_2s (t));
2180 /* Avoid loopback. */
2181 if (GCT_is_loopback (t))
2186 type = ntohs (message->type);
2188 /* Even if tunnel is "being destroyed", send anyway.
2189 * Could be a response to a rekey initiated by remote peer,
2190 * who is trying to create a new channel!
2193 /* Must have a connection, or be looking for one. */
2194 if (NULL == t->connection_head)
2196 LOG (GNUNET_ERROR_TYPE_DEBUG, "%s with no connection\n", GC_m2s (type));
2197 if (CADET_TUNNEL_SEARCHING != t->cstate)
2200 GCT_debug (t, GNUNET_ERROR_TYPE_ERROR);
2201 GCP_debug (t->peer, GNUNET_ERROR_TYPE_ERROR);
2206 msg = (struct GNUNET_CADET_KX *) cbuf;
2207 msg->header.type = htons (GNUNET_MESSAGE_TYPE_CADET_KX);
2208 msg->header.size = htons (sizeof (struct GNUNET_CADET_KX) + size);
2209 c = tunnel_get_connection (t);
2212 if (NULL == t->destroy_task && CADET_TUNNEL_READY == t->cstate)
2215 GCT_debug (t, GNUNET_ERROR_TYPE_ERROR);
2221 case GNUNET_MESSAGE_TYPE_CADET_KX_EPHEMERAL:
2222 case GNUNET_MESSAGE_TYPE_CADET_AX_KX:
2223 GNUNET_assert (NULL == t->ephm_h);
2226 case GNUNET_MESSAGE_TYPE_CADET_KX_PONG:
2227 GNUNET_assert (NULL == t->pong_h);
2232 LOG (GNUNET_ERROR_TYPE_DEBUG, "unkown type %s\n", GC_m2s (type));
2235 memcpy (&msg[1], message, size);
2237 fwd = GCC_is_origin (c, GNUNET_YES);
2239 return GCC_send_prebuilt_message (&msg->header, type, 0, c,
2246 * Send the ephemeral key on a tunnel.
2248 * @param t Tunnel on which to send the key.
2251 send_ephemeral (struct CadetTunnel *t)
2253 LOG (GNUNET_ERROR_TYPE_INFO, "===> EPHM for %s\n", GCT_2s (t));
2254 if (NULL != t->ephm_h)
2256 LOG (GNUNET_ERROR_TYPE_INFO, " already queued\n");
2260 otr_kx_msg.sender_status = htonl (t->estate);
2261 otr_kx_msg.iv = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX);
2262 otr_kx_msg.nonce = t->kx_ctx->challenge;
2263 LOG (GNUNET_ERROR_TYPE_DEBUG, " send nonce c %u\n", otr_kx_msg.nonce);
2264 t_encrypt (t, &otr_kx_msg.nonce, &otr_kx_msg.nonce,
2265 ping_encryption_size(), otr_kx_msg.iv, GNUNET_YES);
2266 LOG (GNUNET_ERROR_TYPE_DEBUG, " send nonce e %u\n", otr_kx_msg.nonce);
2267 t->ephm_h = send_kx (t, &otr_kx_msg.header);
2272 * Send a pong message on a tunnel.
2274 * @param t Tunnel on which to send the pong.
2275 * @param challenge Value sent in the ping that we have to send back.
2278 send_pong (struct CadetTunnel *t, uint32_t challenge)
2280 struct GNUNET_CADET_KX_Pong msg;
2282 LOG (GNUNET_ERROR_TYPE_INFO, "===> PONG for %s\n", GCT_2s (t));
2283 if (NULL != t->pong_h)
2285 LOG (GNUNET_ERROR_TYPE_INFO, " already queued\n");
2288 msg.header.size = htons (sizeof (msg));
2289 msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_KX_PONG);
2290 msg.iv = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX);
2291 msg.nonce = challenge;
2292 LOG (GNUNET_ERROR_TYPE_DEBUG, " sending %u\n", msg.nonce);
2293 t_encrypt (t, &msg.nonce, &msg.nonce,
2294 sizeof (msg.nonce), msg.iv, GNUNET_YES);
2295 LOG (GNUNET_ERROR_TYPE_DEBUG, " e sending %u\n", msg.nonce);
2297 t->pong_h = send_kx (t, &msg.header);
2302 * Initiate a rekey with the remote peer.
2304 * @param cls Closure (tunnel).
2305 * @param tc TaskContext.
2308 rekey_tunnel (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
2310 struct CadetTunnel *t = cls;
2312 t->rekey_task = NULL;
2314 LOG (GNUNET_ERROR_TYPE_INFO, "Re-key Tunnel %s\n", GCT_2s (t));
2315 if (NULL != tc && 0 != (GNUNET_SCHEDULER_REASON_SHUTDOWN & tc->reason))
2318 GNUNET_assert (NULL != t->kx_ctx);
2319 struct GNUNET_TIME_Relative duration;
2321 duration = GNUNET_TIME_absolute_get_duration (t->kx_ctx->rekey_start_time);
2322 LOG (GNUNET_ERROR_TYPE_DEBUG, " kx started %s ago\n",
2323 GNUNET_STRINGS_relative_time_to_string (duration, GNUNET_YES));
2325 // FIXME make duration of old keys configurable
2326 if (duration.rel_value_us >= GNUNET_TIME_UNIT_MINUTES.rel_value_us)
2328 LOG (GNUNET_ERROR_TYPE_DEBUG, " deleting old keys\n");
2329 memset (&t->kx_ctx->d_key_old, 0, sizeof (t->kx_ctx->d_key_old));
2330 memset (&t->kx_ctx->e_key_old, 0, sizeof (t->kx_ctx->e_key_old));
2337 case CADET_TUNNEL_KEY_UNINITIALIZED:
2338 GCT_change_estate (t, CADET_TUNNEL_KEY_SENT);
2341 case CADET_TUNNEL_KEY_SENT:
2344 case CADET_TUNNEL_KEY_OK:
2346 * - state should have changed during rekey_iterator
2347 * - task should have been canceled at pong_handle
2350 GCT_change_estate (t, CADET_TUNNEL_KEY_REKEY);
2353 case CADET_TUNNEL_KEY_PING:
2354 case CADET_TUNNEL_KEY_REKEY:
2358 LOG (GNUNET_ERROR_TYPE_DEBUG, "Unexpected state %u\n", t->estate);
2361 // FIXME exponential backoff
2362 struct GNUNET_TIME_Relative delay;
2364 delay = GNUNET_TIME_relative_divide (rekey_period, 16);
2365 delay = GNUNET_TIME_relative_min (delay, REKEY_WAIT);
2366 LOG (GNUNET_ERROR_TYPE_DEBUG, " next call in %s\n",
2367 GNUNET_STRINGS_relative_time_to_string (delay, GNUNET_YES));
2368 t->rekey_task = GNUNET_SCHEDULER_add_delayed (delay, &rekey_tunnel, t);
2373 * Our ephemeral key has changed, create new session key on all tunnels.
2375 * Each tunnel will start the Key Exchange with a random delay between
2376 * 0 and number_of_tunnels*100 milliseconds, so there are 10 key exchanges
2377 * per second, on average.
2379 * @param cls Closure (size of the hashmap).
2380 * @param key Current public key.
2381 * @param value Value in the hash map (tunnel).
2383 * @return #GNUNET_YES, so we should continue to iterate,
2386 rekey_iterator (void *cls,
2387 const struct GNUNET_PeerIdentity *key,
2390 struct CadetTunnel *t = value;
2391 struct GNUNET_TIME_Relative delay;
2392 long n = (long) cls;
2395 if (NULL != t->rekey_task)
2398 if (GNUNET_YES == GCT_is_loopback (t))
2401 if (CADET_OTR != t->enc_type)
2404 r = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK, (uint32_t) n * 100);
2405 delay = GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MILLISECONDS, r);
2406 t->rekey_task = GNUNET_SCHEDULER_add_delayed (delay, &rekey_tunnel, t);
2407 if (GNUNET_OK == create_kx_ctx (t))
2408 GCT_change_estate (t, CADET_TUNNEL_KEY_REKEY);
2420 * Create a new ephemeral key and key message, schedule next rekeying.
2422 * @param cls Closure (unused).
2423 * @param tc TaskContext.
2426 global_otr_rekey (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
2428 struct GNUNET_TIME_Absolute time;
2433 if (0 != (GNUNET_SCHEDULER_REASON_SHUTDOWN & tc->reason))
2436 GNUNET_free_non_null (otr_ephemeral_key);
2437 otr_ephemeral_key = GNUNET_CRYPTO_ecdhe_key_create ();
2439 time = GNUNET_TIME_absolute_get ();
2440 otr_kx_msg.creation_time = GNUNET_TIME_absolute_hton (time);
2441 time = GNUNET_TIME_absolute_add (time, rekey_period);
2442 time = GNUNET_TIME_absolute_add (time, GNUNET_TIME_UNIT_MINUTES);
2443 otr_kx_msg.expiration_time = GNUNET_TIME_absolute_hton (time);
2444 GNUNET_CRYPTO_ecdhe_key_get_public (otr_ephemeral_key, &otr_kx_msg.ephemeral_key);
2445 LOG (GNUNET_ERROR_TYPE_INFO, "GLOBAL OTR RE-KEY, NEW EPHM: %s\n",
2446 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &otr_kx_msg.ephemeral_key));
2448 GNUNET_assert (GNUNET_OK ==
2449 GNUNET_CRYPTO_eddsa_sign (id_key,
2450 &otr_kx_msg.purpose,
2451 &otr_kx_msg.signature));
2453 n = (long) GNUNET_CONTAINER_multipeermap_size (tunnels);
2454 GNUNET_CONTAINER_multipeermap_iterate (tunnels, &rekey_iterator, (void *) n);
2456 rekey_task = GNUNET_SCHEDULER_add_delayed (rekey_period,
2457 &global_otr_rekey, NULL);
2462 * Called only on shutdown, destroy every tunnel.
2464 * @param cls Closure (unused).
2465 * @param key Current public key.
2466 * @param value Value in the hash map (tunnel).
2468 * @return #GNUNET_YES, so we should continue to iterate,
2471 destroy_iterator (void *cls,
2472 const struct GNUNET_PeerIdentity *key,
2475 struct CadetTunnel *t = value;
2477 LOG (GNUNET_ERROR_TYPE_DEBUG, "GCT_shutdown destroying tunnel at %p\n", t);
2484 * Notify remote peer that we don't know a channel he is talking about,
2485 * probably CHANNEL_DESTROY was missed.
2487 * @param t Tunnel on which to notify.
2488 * @param gid ID of the channel.
2491 send_channel_destroy (struct CadetTunnel *t, unsigned int gid)
2493 struct GNUNET_CADET_ChannelManage msg;
2495 msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_CHANNEL_DESTROY);
2496 msg.header.size = htons (sizeof (msg));
2497 msg.chid = htonl (gid);
2499 LOG (GNUNET_ERROR_TYPE_DEBUG,
2500 "WARNING destroying unknown channel %u on tunnel %s\n",
2502 send_prebuilt_message (&msg.header, t, NULL, GNUNET_YES, NULL, NULL, NULL);
2507 * Demultiplex data per channel and call appropriate channel handler.
2509 * @param t Tunnel on which the data came.
2510 * @param msg Data message.
2511 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
2512 * #GNUNET_YES if message is FWD on the respective channel (loopback)
2513 * #GNUNET_NO if message is BCK on the respective channel (loopback)
2514 * #GNUNET_SYSERR if message on a one-ended channel (remote)
2517 handle_data (struct CadetTunnel *t,
2518 const struct GNUNET_CADET_Data *msg,
2521 struct CadetChannel *ch;
2527 size = ntohs (msg->header.size);
2529 sizeof (struct GNUNET_CADET_Data) +
2530 sizeof (struct GNUNET_MessageHeader))
2535 type = ntohs (msg[1].header.type);
2536 LOG (GNUNET_ERROR_TYPE_DEBUG, " payload of type %s\n", GC_m2s (type));
2537 sprintf (buf, "# received payload of type %hu", type);
2538 GNUNET_STATISTICS_update (stats, buf, 1, GNUNET_NO);
2542 ch = GCT_get_channel (t, ntohl (msg->chid));
2545 GNUNET_STATISTICS_update (stats, "# data on unknown channel",
2547 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel 0x%X unknown\n",
2549 send_channel_destroy (t, ntohl (msg->chid));
2553 GCCH_handle_data (ch, msg, fwd);
2558 * Demultiplex data ACKs per channel and update appropriate channel buffer info.
2560 * @param t Tunnel on which the DATA ACK came.
2561 * @param msg DATA ACK message.
2562 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
2563 * #GNUNET_YES if message is FWD on the respective channel (loopback)
2564 * #GNUNET_NO if message is BCK on the respective channel (loopback)
2565 * #GNUNET_SYSERR if message on a one-ended channel (remote)
2568 handle_data_ack (struct CadetTunnel *t,
2569 const struct GNUNET_CADET_DataACK *msg,
2572 struct CadetChannel *ch;
2576 size = ntohs (msg->header.size);
2577 if (size != sizeof (struct GNUNET_CADET_DataACK))
2584 ch = GCT_get_channel (t, ntohl (msg->chid));
2587 GNUNET_STATISTICS_update (stats, "# data ack on unknown channel",
2589 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel %u unknown\n",
2594 GCCH_handle_data_ack (ch, msg, fwd);
2599 * Handle channel create.
2601 * @param t Tunnel on which the data came.
2602 * @param msg Data message.
2605 handle_ch_create (struct CadetTunnel *t,
2606 const struct GNUNET_CADET_ChannelCreate *msg)
2608 struct CadetChannel *ch;
2612 size = ntohs (msg->header.size);
2613 if (size != sizeof (struct GNUNET_CADET_ChannelCreate))
2620 ch = GCT_get_channel (t, ntohl (msg->chid));
2621 if (NULL != ch && ! GCT_is_loopback (t))
2623 /* Probably a retransmission, safe to ignore */
2624 LOG (GNUNET_ERROR_TYPE_DEBUG, " already exists...\n");
2626 ch = GCCH_handle_create (t, msg);
2628 GCT_add_channel (t, ch);
2634 * Handle channel NACK: check correctness and call channel handler for NACKs.
2636 * @param t Tunnel on which the NACK came.
2637 * @param msg NACK message.
2640 handle_ch_nack (struct CadetTunnel *t,
2641 const struct GNUNET_CADET_ChannelManage *msg)
2643 struct CadetChannel *ch;
2647 size = ntohs (msg->header.size);
2648 if (size != sizeof (struct GNUNET_CADET_ChannelManage))
2655 ch = GCT_get_channel (t, ntohl (msg->chid));
2658 GNUNET_STATISTICS_update (stats, "# channel NACK on unknown channel",
2660 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel %u unknown\n",
2665 GCCH_handle_nack (ch);
2670 * Handle a CHANNEL ACK (SYNACK/ACK).
2672 * @param t Tunnel on which the CHANNEL ACK came.
2673 * @param msg CHANNEL ACK message.
2674 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
2675 * #GNUNET_YES if message is FWD on the respective channel (loopback)
2676 * #GNUNET_NO if message is BCK on the respective channel (loopback)
2677 * #GNUNET_SYSERR if message on a one-ended channel (remote)
2680 handle_ch_ack (struct CadetTunnel *t,
2681 const struct GNUNET_CADET_ChannelManage *msg,
2684 struct CadetChannel *ch;
2688 size = ntohs (msg->header.size);
2689 if (size != sizeof (struct GNUNET_CADET_ChannelManage))
2696 ch = GCT_get_channel (t, ntohl (msg->chid));
2699 GNUNET_STATISTICS_update (stats, "# channel ack on unknown channel",
2701 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel %u unknown\n",
2706 GCCH_handle_ack (ch, msg, fwd);
2711 * Handle a channel destruction message.
2713 * @param t Tunnel on which the message came.
2714 * @param msg Channel destroy message.
2715 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
2716 * #GNUNET_YES if message is FWD on the respective channel (loopback)
2717 * #GNUNET_NO if message is BCK on the respective channel (loopback)
2718 * #GNUNET_SYSERR if message on a one-ended channel (remote)
2721 handle_ch_destroy (struct CadetTunnel *t,
2722 const struct GNUNET_CADET_ChannelManage *msg,
2725 struct CadetChannel *ch;
2729 size = ntohs (msg->header.size);
2730 if (size != sizeof (struct GNUNET_CADET_ChannelManage))
2737 ch = GCT_get_channel (t, ntohl (msg->chid));
2740 /* Probably a retransmission, safe to ignore */
2744 GCCH_handle_destroy (ch, msg, fwd);
2749 * Free Axolotl data.
2754 destroy_ax (struct CadetTunnel *t)
2759 GNUNET_free_non_null (t->ax->DHRs);
2760 GNUNET_free_non_null (t->ax->kx_0);
2761 while (NULL != t->ax->skipped_head)
2762 delete_skipped_key (t, t->ax->skipped_head);
2763 GNUNET_assert (0 == t->ax->skipped);
2765 GNUNET_free (t->ax);
2768 if (NULL != t->rekey_task)
2770 GNUNET_SCHEDULER_cancel (t->rekey_task);
2771 t->rekey_task = NULL;
2773 if (NULL != t->ephm_h)
2775 GCC_cancel (t->ephm_h);
2782 * The peer's ephemeral key has changed: update the symmetrical keys.
2784 * @param t Tunnel this message came on.
2785 * @param msg Key eXchange message.
2788 handle_ephemeral (struct CadetTunnel *t,
2789 const struct GNUNET_CADET_KX_Ephemeral *msg)
2791 LOG (GNUNET_ERROR_TYPE_INFO, "<=== EPHM for %s\n", GCT_2s (t));
2793 /* Some old versions are still around, don't log as error. */
2794 if (GNUNET_OK != check_ephemeral (t, msg))
2797 /* If we get a proper OTR-style ephemeral, fallback to old crypto. */
2801 t->enc_type = CADET_OTR;
2802 if (NULL != t->rekey_task)
2803 GNUNET_SCHEDULER_cancel (t->rekey_task);
2804 if (GNUNET_OK != create_kx_ctx (t))
2810 rekey_tunnel (t, NULL);
2811 GNUNET_STATISTICS_update (stats, "# otr-downgrades", -1, GNUNET_NO);
2815 * If the key is different from what we know, derive the new E/D keys.
2816 * Else destroy the rekey ctx (duplicate EPHM after successful KX).
2818 if (0 != memcmp (&t->peers_ephemeral_key, &msg->ephemeral_key,
2819 sizeof (msg->ephemeral_key)))
2821 #if DUMP_KEYS_TO_STDERR
2822 LOG (GNUNET_ERROR_TYPE_INFO, "OLD: %s\n",
2823 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &t->peers_ephemeral_key));
2824 LOG (GNUNET_ERROR_TYPE_INFO, "NEW: %s\n",
2825 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &msg->ephemeral_key));
2827 t->peers_ephemeral_key = msg->ephemeral_key;
2829 if (GNUNET_OK != create_kx_ctx (t))
2836 if (CADET_TUNNEL_KEY_OK == t->estate)
2838 GCT_change_estate (t, CADET_TUNNEL_KEY_REKEY);
2840 if (NULL != t->rekey_task)
2841 GNUNET_SCHEDULER_cancel (t->rekey_task);
2842 t->rekey_task = GNUNET_SCHEDULER_add_now (rekey_tunnel, t);
2844 if (CADET_TUNNEL_KEY_SENT == t->estate)
2846 LOG (GNUNET_ERROR_TYPE_DEBUG, " our key was sent, sending challenge\n");
2848 GCT_change_estate (t, CADET_TUNNEL_KEY_PING);
2851 if (CADET_TUNNEL_KEY_UNINITIALIZED != ntohl(msg->sender_status))
2855 LOG (GNUNET_ERROR_TYPE_DEBUG, " recv nonce e %u\n", msg->nonce);
2856 t_decrypt (t, &nonce, &msg->nonce, ping_encryption_size (), msg->iv);
2857 LOG (GNUNET_ERROR_TYPE_DEBUG, " recv nonce c %u\n", nonce);
2858 send_pong (t, nonce);
2864 * Peer has answer to our challenge.
2865 * If answer is successful, consider the key exchange finished and clean
2866 * up all related state.
2868 * @param t Tunnel this message came on.
2869 * @param msg Key eXchange Pong message.
2872 handle_pong (struct CadetTunnel *t,
2873 const struct GNUNET_CADET_KX_Pong *msg)
2877 LOG (GNUNET_ERROR_TYPE_INFO, "<=== PONG for %s\n", GCT_2s (t));
2878 if (NULL == t->rekey_task)
2880 GNUNET_STATISTICS_update (stats, "# duplicate PONG messages", 1, GNUNET_NO);
2883 if (NULL == t->kx_ctx)
2885 GNUNET_STATISTICS_update (stats, "# stray PONG messages", 1, GNUNET_NO);
2889 t_decrypt (t, &challenge, &msg->nonce, sizeof (uint32_t), msg->iv);
2890 if (challenge != t->kx_ctx->challenge)
2892 LOG (GNUNET_ERROR_TYPE_WARNING, "Wrong PONG challenge on %s\n", GCT_2s (t));
2893 LOG (GNUNET_ERROR_TYPE_DEBUG, "PONG: %u (e: %u). Expected: %u.\n",
2894 challenge, msg->nonce, t->kx_ctx->challenge);
2898 GNUNET_SCHEDULER_cancel (t->rekey_task);
2899 t->rekey_task = NULL;
2901 /* Don't free the old keys right away, but after a delay.
2902 * Rationale: the KX could have happened over a very fast connection,
2903 * with payload traffic still signed with the old key stuck in a slower
2905 * Don't keep the keys longer than 1/4 the rekey period, and no longer than
2909 GCT_change_estate (t, CADET_TUNNEL_KEY_OK);
2914 * Handle Axolotl handshake.
2916 * @param t Tunnel this message came on.
2917 * @param msg Key eXchange Pong message.
2920 handle_kx_ax (struct CadetTunnel *t, const struct GNUNET_CADET_AX_KX *msg)
2922 struct CadetTunnelAxolotl *ax;
2923 struct GNUNET_HashCode key_material[3];
2924 struct GNUNET_CRYPTO_SymmetricSessionKey keys[5];
2925 const char salt[] = "CADET Axolotl salt";
2926 const struct GNUNET_PeerIdentity *pid;
2929 LOG (GNUNET_ERROR_TYPE_INFO, "<=== AX_KX on %s\n", GCT_2s (t));
2933 /* Something is wrong if ax is NULL. Whose fault it is? */
2934 GNUNET_break_op (CADET_OTR == t->enc_type);
2935 GNUNET_break (CADET_Axolotl == t->enc_type);
2940 pid = GCT_get_destination (t);
2941 if (0 > GNUNET_CRYPTO_cmp_peer_identity (&my_full_id, pid))
2942 am_I_alice = GNUNET_YES;
2943 else if (0 < GNUNET_CRYPTO_cmp_peer_identity (&my_full_id, pid))
2944 am_I_alice = GNUNET_NO;
2947 GNUNET_break_op (0);
2951 if (0 != (GNUNET_CADET_AX_KX_FLAG_FORCE_REPLY & ntohl (msg->flags)))
2953 if (NULL != t->rekey_task)
2955 GNUNET_SCHEDULER_cancel (t->rekey_task);
2956 t->rekey_task = NULL;
2958 GCT_send_ax_kx (t, GNUNET_NO);
2961 if (0 == memcmp (&ax->DHRr, &msg->ratchet_key, sizeof(msg->ratchet_key)))
2963 LOG (GNUNET_ERROR_TYPE_INFO, " known ratchet key, exit\n");
2967 LOG (GNUNET_ERROR_TYPE_INFO, " is Alice? %s\n", am_I_alice ? "YES" : "NO");
2969 ax->DHRr = msg->ratchet_key;
2972 if (GNUNET_YES == am_I_alice)
2974 GNUNET_CRYPTO_eddsa_ecdh (id_key, /* A */
2975 &msg->ephemeral_key, /* B0 */
2980 GNUNET_CRYPTO_ecdh_eddsa (ax->kx_0, /* B0 */
2981 &pid->public_key, /* A */
2986 if (GNUNET_YES == am_I_alice)
2988 GNUNET_CRYPTO_ecdh_eddsa (ax->kx_0, /* A0 */
2989 &pid->public_key, /* B */
2994 GNUNET_CRYPTO_eddsa_ecdh (id_key, /* A */
2995 &msg->ephemeral_key, /* B0 */
3002 /* (This is the triple-DH, we could probably safely skip this,
3003 as A0/B0 are already in the key material.) */
3004 GNUNET_CRYPTO_ecc_ecdh (ax->kx_0, /* A0 or B0 */
3005 &msg->ephemeral_key, /* B0 or A0 */
3008 #if DUMP_KEYS_TO_STDERR
3011 for (i = 0; i < 3; i++)
3012 LOG (GNUNET_ERROR_TYPE_INFO, "km[%u]: %s\n",
3013 i, GNUNET_h2s (&key_material[i]));
3018 GNUNET_CRYPTO_kdf (keys, sizeof (keys),
3019 salt, sizeof (salt),
3020 &key_material, sizeof (key_material), NULL);
3022 if (0 == memcmp (&ax->RK, &keys[0], sizeof(ax->RK)))
3024 LOG (GNUNET_ERROR_TYPE_INFO, " known handshake key, exit\n");
3028 if (GNUNET_YES == am_I_alice)
3034 ax->ratchet_flag = GNUNET_YES;
3042 ax->ratchet_flag = GNUNET_NO;
3043 ax->ratchet_allowed = GNUNET_NO;
3044 ax->ratchet_counter = 0;
3045 ax->ratchet_expiration =
3046 GNUNET_TIME_absolute_add (GNUNET_TIME_absolute_get(), ratchet_time);
3051 GCT_change_estate (t, CADET_TUNNEL_KEY_PING);
3052 send_queued_data (t);
3057 * Demultiplex by message type and call appropriate handler for a message
3058 * towards a channel of a local tunnel.
3060 * @param t Tunnel this message came on.
3061 * @param msgh Message header.
3062 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
3063 * #GNUNET_YES if message is FWD on the respective channel (loopback)
3064 * #GNUNET_NO if message is BCK on the respective channel (loopback)
3065 * #GNUNET_SYSERR if message on a one-ended channel (remote)
3068 handle_decrypted (struct CadetTunnel *t,
3069 const struct GNUNET_MessageHeader *msgh,
3075 type = ntohs (msgh->type);
3076 LOG (GNUNET_ERROR_TYPE_INFO, "<=== %s on %s\n", GC_m2s (type), GCT_2s (t));
3077 sprintf (buf, "# received encrypted of type %hu (%s)", type, GC_m2s (type));
3078 GNUNET_STATISTICS_update (stats, buf, 1, GNUNET_NO);
3082 case GNUNET_MESSAGE_TYPE_CADET_KEEPALIVE:
3083 /* Do nothing, connection aleady got updated. */
3084 GNUNET_STATISTICS_update (stats, "# keepalives received", 1, GNUNET_NO);
3087 case GNUNET_MESSAGE_TYPE_CADET_DATA:
3088 /* Don't send hop ACK, wait for client to ACK */
3089 handle_data (t, (struct GNUNET_CADET_Data *) msgh, fwd);
3092 case GNUNET_MESSAGE_TYPE_CADET_DATA_ACK:
3093 handle_data_ack (t, (struct GNUNET_CADET_DataACK *) msgh, fwd);
3096 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_CREATE:
3097 handle_ch_create (t, (struct GNUNET_CADET_ChannelCreate *) msgh);
3100 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_NACK:
3101 handle_ch_nack (t, (struct GNUNET_CADET_ChannelManage *) msgh);
3104 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_ACK:
3105 handle_ch_ack (t, (struct GNUNET_CADET_ChannelManage *) msgh, fwd);
3108 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_DESTROY:
3109 handle_ch_destroy (t, (struct GNUNET_CADET_ChannelManage *) msgh, fwd);
3113 GNUNET_break_op (0);
3114 LOG (GNUNET_ERROR_TYPE_WARNING,
3115 "end-to-end message not known (%u)\n",
3116 ntohs (msgh->type));
3117 GCT_debug (t, GNUNET_ERROR_TYPE_WARNING);
3122 /******************************************************************************/
3123 /******************************** API ***********************************/
3124 /******************************************************************************/
3126 * Decrypt old format and demultiplex by message type. Call appropriate handler
3127 * for a message towards a channel of a local tunnel.
3129 * @param t Tunnel this message came on.
3130 * @param msg Message header.
3133 GCT_handle_encrypted (struct CadetTunnel *t,
3134 const struct GNUNET_MessageHeader *msg)
3136 uint16_t size = ntohs (msg->size);
3140 const struct GNUNET_MessageHeader *msgh;
3143 type = ntohs (msg->type);
3146 case GNUNET_MESSAGE_TYPE_CADET_ENCRYPTED:
3148 const struct GNUNET_CADET_Encrypted *emsg;
3149 size_t payload_size;
3151 GNUNET_STATISTICS_update (stats, "# received OTR", 1, GNUNET_NO);
3152 emsg = (const struct GNUNET_CADET_Encrypted *) msg;
3153 payload_size = size - sizeof (struct GNUNET_CADET_Encrypted);
3154 decrypted_size = t_decrypt_and_validate (t, cbuf, &emsg[1], payload_size,
3155 emsg->iv, &emsg->hmac);
3158 case GNUNET_MESSAGE_TYPE_CADET_AX:
3160 const struct GNUNET_CADET_AX *emsg;
3162 GNUNET_STATISTICS_update (stats, "# received Axolotl", 1, GNUNET_NO);
3163 emsg = (const struct GNUNET_CADET_AX *) msg;
3164 decrypted_size = t_ax_decrypt_and_validate (t, cbuf, emsg, size);
3168 GNUNET_break_op (0);
3172 if (-1 == decrypted_size)
3174 GNUNET_break_op (0);
3175 GNUNET_STATISTICS_update (stats, "# unable to decrypt", 1, GNUNET_NO);
3176 LOG (GNUNET_ERROR_TYPE_WARNING, "Wrong crypto on tunnel %s\n", GCT_2s (t));
3177 GCT_debug (t, GNUNET_ERROR_TYPE_WARNING);
3180 GCT_change_estate (t, CADET_TUNNEL_KEY_OK);
3182 /* FIXME: this is bad, as the structs returned from
3183 this loop may be unaligned, see util's MST for
3184 how to do this right. */
3186 while (off + sizeof (struct GNUNET_MessageHeader) <= decrypted_size)
3190 msgh = (const struct GNUNET_MessageHeader *) &cbuf[off];
3191 msize = ntohs (msgh->size);
3192 if (msize < sizeof (struct GNUNET_MessageHeader))
3194 GNUNET_break_op (0);
3197 if (off + msize < decrypted_size)
3199 GNUNET_break_op (0);
3202 handle_decrypted (t, msgh, GNUNET_SYSERR);
3209 * Demultiplex an encapsulated KX message by message type.
3211 * @param t Tunnel on which the message came.
3212 * @param message Payload of KX message.
3215 GCT_handle_kx (struct CadetTunnel *t,
3216 const struct GNUNET_MessageHeader *message)
3221 type = ntohs (message->type);
3222 LOG (GNUNET_ERROR_TYPE_DEBUG, "kx message received: %s\n", GC_m2s (type));
3223 sprintf (buf, "# received KX of type %hu (%s)", type, GC_m2s (type));
3224 GNUNET_STATISTICS_update (stats, buf, 1, GNUNET_NO);
3227 case GNUNET_MESSAGE_TYPE_CADET_KX_EPHEMERAL:
3228 handle_ephemeral (t, (const struct GNUNET_CADET_KX_Ephemeral *) message);
3231 case GNUNET_MESSAGE_TYPE_CADET_KX_PONG:
3232 handle_pong (t, (const struct GNUNET_CADET_KX_Pong *) message);
3235 case GNUNET_MESSAGE_TYPE_CADET_AX_KX:
3236 handle_kx_ax (t, (const struct GNUNET_CADET_AX_KX *) message);
3240 GNUNET_break_op (0);
3241 LOG (GNUNET_ERROR_TYPE_WARNING, "kx message %s unknown\n", GC_m2s (type));
3246 * Initialize the tunnel subsystem.
3248 * @param c Configuration handle.
3249 * @param key ECC private key, to derive all other keys and do crypto.
3252 GCT_init (const struct GNUNET_CONFIGURATION_Handle *c,
3253 const struct GNUNET_CRYPTO_EddsaPrivateKey *key)
3255 int expected_overhead;
3257 LOG (GNUNET_ERROR_TYPE_DEBUG, "init\n");
3259 expected_overhead = 0;
3260 expected_overhead += sizeof (struct GNUNET_CADET_Encrypted);
3261 expected_overhead += sizeof (struct GNUNET_CADET_Data);
3262 expected_overhead += sizeof (struct GNUNET_CADET_ACK);
3263 GNUNET_assert (GNUNET_CONSTANTS_CADET_P2P_OVERHEAD == expected_overhead);
3266 GNUNET_CONFIGURATION_get_value_number (c, "CADET", "DEFAULT_TTL",
3269 GNUNET_log_config_invalid (GNUNET_ERROR_TYPE_DEBUG,
3270 "CADET", "DEFAULT_TTL", "USING DEFAULT");
3274 GNUNET_CONFIGURATION_get_value_time (c, "CADET", "REKEY_PERIOD",
3277 rekey_period = GNUNET_TIME_UNIT_DAYS;
3280 GNUNET_CONFIGURATION_get_value_number (c, "CADET", "RATCHET_MESSAGES",
3283 GNUNET_log_config_invalid (GNUNET_ERROR_TYPE_WARNING,
3284 "CADET", "RATCHET_MESSAGES", "USING DEFAULT");
3285 ratchet_messages = 64;
3288 GNUNET_CONFIGURATION_get_value_time (c, "CADET", "RATCHET_TIME",
3291 GNUNET_log_config_invalid (GNUNET_ERROR_TYPE_WARNING,
3292 "CADET", "RATCHET_TIME", "USING DEFAULT");
3293 ratchet_time = GNUNET_TIME_UNIT_HOURS;
3299 otr_kx_msg.header.size = htons (sizeof (otr_kx_msg));
3300 otr_kx_msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_KX_EPHEMERAL);
3301 otr_kx_msg.purpose.purpose = htonl (GNUNET_SIGNATURE_PURPOSE_CADET_KX);
3302 otr_kx_msg.purpose.size = htonl (ephemeral_purpose_size ());
3303 otr_kx_msg.origin_identity = my_full_id;
3304 rekey_task = GNUNET_SCHEDULER_add_now (&global_otr_rekey, NULL);
3305 tunnels = GNUNET_CONTAINER_multipeermap_create (128, GNUNET_YES);
3310 * Shut down the tunnel subsystem.
3315 LOG (GNUNET_ERROR_TYPE_DEBUG, "Shutting down tunnels\n");
3316 if (NULL != rekey_task)
3318 GNUNET_SCHEDULER_cancel (rekey_task);
3321 GNUNET_CONTAINER_multipeermap_iterate (tunnels, &destroy_iterator, NULL);
3322 GNUNET_CONTAINER_multipeermap_destroy (tunnels);
3329 * @param destination Peer this tunnel is towards.
3331 struct CadetTunnel *
3332 GCT_new (struct CadetPeer *destination)
3334 struct CadetTunnel *t;
3336 t = GNUNET_new (struct CadetTunnel);
3338 t->peer = destination;
3341 GNUNET_CONTAINER_multipeermap_put (tunnels, GCP_get_id (destination), t,
3342 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_FAST))
3348 t->ax = GNUNET_new (struct CadetTunnelAxolotl);
3350 t->ax->kx_0 = GNUNET_CRYPTO_ecdhe_key_create ();
3356 * Change the tunnel's connection state.
3358 * @param t Tunnel whose connection state to change.
3359 * @param cstate New connection state.
3362 GCT_change_cstate (struct CadetTunnel* t, enum CadetTunnelCState cstate)
3366 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel %s cstate %s => %s\n",
3367 GCP_2s (t->peer), cstate2s (t->cstate), cstate2s (cstate));
3368 if (myid != GCP_get_short_id (t->peer) &&
3369 CADET_TUNNEL_READY != t->cstate &&
3370 CADET_TUNNEL_READY == cstate)
3373 if (CADET_TUNNEL_KEY_OK == t->estate)
3375 LOG (GNUNET_ERROR_TYPE_DEBUG, " cstate triggered send queued data\n");
3376 send_queued_data (t);
3378 else if (CADET_TUNNEL_KEY_UNINITIALIZED == t->estate)
3380 LOG (GNUNET_ERROR_TYPE_DEBUG, " cstate triggered kx\n");
3381 GCT_send_ax_kx (t, GNUNET_NO);
3385 LOG (GNUNET_ERROR_TYPE_DEBUG, "estate %s\n", estate2s (t->estate));
3390 if (CADET_TUNNEL_READY == cstate
3391 && CONNECTIONS_PER_TUNNEL <= GCT_count_connections (t))
3393 LOG (GNUNET_ERROR_TYPE_DEBUG, " cstate triggered stop dht\n");
3394 GCP_stop_search (t->peer);
3400 * Change the tunnel encryption state.
3402 * If the encryption state changes to OK, stop the rekey task.
3404 * @param t Tunnel whose encryption state to change, or NULL.
3405 * @param state New encryption state.
3408 GCT_change_estate (struct CadetTunnel* t, enum CadetTunnelEState state)
3410 enum CadetTunnelEState old;
3417 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel %s estate was %s\n",
3418 GCP_2s (t->peer), estate2s (old));
3419 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel %s estate is now %s\n",
3420 GCP_2s (t->peer), estate2s (t->estate));
3422 if (CADET_TUNNEL_KEY_OK != old && CADET_TUNNEL_KEY_OK == t->estate)
3424 if (NULL != t->rekey_task)
3426 GNUNET_SCHEDULER_cancel (t->rekey_task);
3427 t->rekey_task = NULL;
3429 /* Send queued data if tunnel is not loopback */
3430 if (myid != GCP_get_short_id (t->peer))
3431 send_queued_data (t);
3437 * @brief Check if tunnel has too many connections, and remove one if necessary.
3439 * Currently this means the newest connection, unless it is a direct one.
3440 * Implemented as a task to avoid freeing a connection that is in the middle
3441 * of being created/processed.
3443 * @param cls Closure (Tunnel to check).
3444 * @param tc Task context.
3447 trim_connections (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
3449 struct CadetTunnel *t = cls;
3451 t->trim_connections_task = NULL;
3453 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
3456 if (GCT_count_connections (t) > 2 * CONNECTIONS_PER_TUNNEL)
3458 struct CadetTConnection *iter;
3459 struct CadetTConnection *c;
3461 for (c = iter = t->connection_head; NULL != iter; iter = iter->next)
3463 if ((iter->created.abs_value_us > c->created.abs_value_us)
3464 && GNUNET_NO == GCC_is_direct (iter->c))
3471 LOG (GNUNET_ERROR_TYPE_DEBUG, "Too many connections on tunnel %s\n",
3473 LOG (GNUNET_ERROR_TYPE_DEBUG, "Destroying connection %s\n",
3486 * Add a connection to a tunnel.
3489 * @param c Connection.
3492 GCT_add_connection (struct CadetTunnel *t, struct CadetConnection *c)
3494 struct CadetTConnection *aux;
3496 GNUNET_assert (NULL != c);
3498 LOG (GNUNET_ERROR_TYPE_DEBUG, "add connection %s\n", GCC_2s (c));
3499 LOG (GNUNET_ERROR_TYPE_DEBUG, " to tunnel %s\n", GCT_2s (t));
3500 for (aux = t->connection_head; aux != NULL; aux = aux->next)
3504 aux = GNUNET_new (struct CadetTConnection);
3506 aux->created = GNUNET_TIME_absolute_get ();
3508 GNUNET_CONTAINER_DLL_insert (t->connection_head, t->connection_tail, aux);
3510 if (CADET_TUNNEL_SEARCHING == t->cstate)
3511 GCT_change_cstate (t, CADET_TUNNEL_WAITING);
3513 if (NULL != t->trim_connections_task)
3514 t->trim_connections_task = GNUNET_SCHEDULER_add_now (&trim_connections, t);
3519 * Remove a connection from a tunnel.
3522 * @param c Connection.
3525 GCT_remove_connection (struct CadetTunnel *t,
3526 struct CadetConnection *c)
3528 struct CadetTConnection *aux;
3529 struct CadetTConnection *next;
3532 LOG (GNUNET_ERROR_TYPE_DEBUG, "Removing connection %s from tunnel %s\n",
3533 GCC_2s (c), GCT_2s (t));
3534 for (aux = t->connection_head; aux != NULL; aux = next)
3539 GNUNET_CONTAINER_DLL_remove (t->connection_head, t->connection_tail, aux);
3544 conns = GCT_count_connections (t);
3546 && NULL == t->destroy_task
3547 && CADET_TUNNEL_SHUTDOWN != t->cstate
3548 && GNUNET_NO == shutting_down)
3550 if (0 == GCT_count_any_connections (t))
3551 GCT_change_cstate (t, CADET_TUNNEL_SEARCHING);
3553 GCT_change_cstate (t, CADET_TUNNEL_WAITING);
3556 /* Start new connections if needed */
3557 if (CONNECTIONS_PER_TUNNEL > conns
3558 && CADET_TUNNEL_SHUTDOWN != t->cstate
3559 && GNUNET_NO == shutting_down)
3561 LOG (GNUNET_ERROR_TYPE_DEBUG, " too few connections, getting new ones\n");
3562 GCP_connect (t->peer); /* Will change cstate to WAITING when possible */
3566 /* If not marked as ready, no change is needed */
3567 if (CADET_TUNNEL_READY != t->cstate)
3570 /* Check if any connection is ready to maintain cstate */
3571 for (aux = t->connection_head; aux != NULL; aux = aux->next)
3572 if (CADET_CONNECTION_READY == GCC_get_state (aux->c))
3578 * Add a channel to a tunnel.
3581 * @param ch Channel.
3584 GCT_add_channel (struct CadetTunnel *t, struct CadetChannel *ch)
3586 struct CadetTChannel *aux;
3588 GNUNET_assert (NULL != ch);
3590 LOG (GNUNET_ERROR_TYPE_DEBUG, "Adding channel %p to tunnel %p\n", ch, t);
3592 for (aux = t->channel_head; aux != NULL; aux = aux->next)
3594 LOG (GNUNET_ERROR_TYPE_DEBUG, " already there %p\n", aux->ch);
3599 aux = GNUNET_new (struct CadetTChannel);
3601 LOG (GNUNET_ERROR_TYPE_DEBUG, " adding %p to %p\n", aux, t->channel_head);
3602 GNUNET_CONTAINER_DLL_insert_tail (t->channel_head, t->channel_tail, aux);
3604 if (NULL != t->destroy_task)
3606 GNUNET_SCHEDULER_cancel (t->destroy_task);
3607 t->destroy_task = NULL;
3608 LOG (GNUNET_ERROR_TYPE_DEBUG, " undo destroy!\n");
3614 * Remove a channel from a tunnel.
3617 * @param ch Channel.
3620 GCT_remove_channel (struct CadetTunnel *t, struct CadetChannel *ch)
3622 struct CadetTChannel *aux;
3624 LOG (GNUNET_ERROR_TYPE_DEBUG, "Removing channel %p from tunnel %p\n", ch, t);
3625 for (aux = t->channel_head; aux != NULL; aux = aux->next)
3629 LOG (GNUNET_ERROR_TYPE_DEBUG, " found! %s\n", GCCH_2s (ch));
3630 GNUNET_CONTAINER_DLL_remove (t->channel_head, t->channel_tail, aux);
3639 * Search for a channel by global ID.
3641 * @param t Tunnel containing the channel.
3642 * @param chid Public channel number.
3644 * @return channel handler, NULL if doesn't exist
3646 struct CadetChannel *
3647 GCT_get_channel (struct CadetTunnel *t, CADET_ChannelNumber chid)
3649 struct CadetTChannel *iter;
3654 for (iter = t->channel_head; NULL != iter; iter = iter->next)
3656 if (GCCH_get_id (iter->ch) == chid)
3660 return NULL == iter ? NULL : iter->ch;
3665 * @brief Destroy a tunnel and free all resources.
3667 * Should only be called a while after the tunnel has been marked as destroyed,
3668 * in case there is a new channel added to the same peer shortly after marking
3669 * the tunnel. This way we avoid a new public key handshake.
3671 * @param cls Closure (tunnel to destroy).
3672 * @param tc Task context.
3675 delayed_destroy (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
3677 struct CadetTunnel *t = cls;
3678 struct CadetTConnection *iter;
3680 LOG (GNUNET_ERROR_TYPE_DEBUG, "delayed destroying tunnel %p\n", t);
3681 if (0 != (GNUNET_SCHEDULER_REASON_SHUTDOWN & tc->reason))
3683 LOG (GNUNET_ERROR_TYPE_WARNING,
3684 "Not destroying tunnel, due to shutdown. "
3685 "Tunnel at %p should have been freed by GCT_shutdown\n", t);
3688 t->destroy_task = NULL;
3689 t->cstate = CADET_TUNNEL_SHUTDOWN;
3691 for (iter = t->connection_head; NULL != iter; iter = iter->next)
3693 GCC_send_destroy (iter->c);
3700 * Tunnel is empty: destroy it.
3702 * Notifies all connections about the destruction.
3704 * @param t Tunnel to destroy.
3707 GCT_destroy_empty (struct CadetTunnel *t)
3709 if (GNUNET_YES == shutting_down)
3710 return; /* Will be destroyed immediately anyway */
3712 if (NULL != t->destroy_task)
3714 LOG (GNUNET_ERROR_TYPE_WARNING,
3715 "Tunnel %s is already scheduled for destruction. Tunnel debug dump:\n",
3717 GCT_debug (t, GNUNET_ERROR_TYPE_WARNING);
3719 /* should never happen, tunnel can only become empty once, and the
3720 * task identifier should be NO_TASK (cleaned when the tunnel was created
3721 * or became un-empty)
3726 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel %s empty: scheduling destruction\n",
3729 // FIXME make delay a config option
3730 t->destroy_task = GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_MINUTES,
3731 &delayed_destroy, t);
3732 LOG (GNUNET_ERROR_TYPE_DEBUG, "Scheduled destroy of %p as %p\n",
3733 t, t->destroy_task);
3738 * Destroy tunnel if empty (no more channels).
3740 * @param t Tunnel to destroy if empty.
3743 GCT_destroy_if_empty (struct CadetTunnel *t)
3745 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel %s destroy if empty\n", GCT_2s (t));
3746 if (0 < GCT_count_channels (t))
3749 GCT_destroy_empty (t);
3754 * Destroy the tunnel.
3756 * This function does not generate any warning traffic to clients or peers.
3759 * Cancel messages belonging to this tunnel queued to neighbors.
3760 * Free any allocated resources linked to the tunnel.
3762 * @param t The tunnel to destroy.
3765 GCT_destroy (struct CadetTunnel *t)
3767 struct CadetTConnection *iter_c;
3768 struct CadetTConnection *next_c;
3769 struct CadetTChannel *iter_ch;
3770 struct CadetTChannel *next_ch;
3771 unsigned int keepalives_queued;
3776 LOG (GNUNET_ERROR_TYPE_DEBUG, "destroying tunnel %s\n", GCP_2s (t->peer));
3778 GNUNET_break (GNUNET_YES ==
3779 GNUNET_CONTAINER_multipeermap_remove (tunnels,
3780 GCP_get_id (t->peer), t));
3782 for (iter_c = t->connection_head; NULL != iter_c; iter_c = next_c)
3784 next_c = iter_c->next;
3785 GCC_destroy (iter_c->c);
3787 for (iter_ch = t->channel_head; NULL != iter_ch; iter_ch = next_ch)
3789 next_ch = iter_ch->next;
3790 GCCH_destroy (iter_ch->ch);
3791 /* Should only happen on shutdown, but it's ok. */
3793 keepalives_queued = 0;
3794 while (NULL != t->tq_head)
3796 /* Should have been cleaned by destuction of channel. */
3797 struct GNUNET_MessageHeader *mh;
3800 mh = (struct GNUNET_MessageHeader *) &t->tq_head[1];
3801 type = ntohs (mh->type);
3802 if (0 == keepalives_queued && GNUNET_MESSAGE_TYPE_CADET_KEEPALIVE == type)
3804 keepalives_queued = 1;
3805 LOG (GNUNET_ERROR_TYPE_DEBUG,
3806 "one keepalive left behind on tunnel shutdown\n");
3808 else if (GNUNET_MESSAGE_TYPE_CADET_CHANNEL_DESTROY == type)
3810 LOG (GNUNET_ERROR_TYPE_WARNING,
3811 "tunnel destroyed before a CHANNEL_DESTROY was sent to peer\n");
3816 LOG (GNUNET_ERROR_TYPE_ERROR,
3817 "message left behind on tunnel shutdown: %s\n",
3820 unqueue_data (t->tq_head);
3824 if (NULL != t->destroy_task)
3826 LOG (GNUNET_ERROR_TYPE_DEBUG, "cancelling dest: %p\n", t->destroy_task);
3827 GNUNET_SCHEDULER_cancel (t->destroy_task);
3828 t->destroy_task = NULL;
3831 if (NULL != t->trim_connections_task)
3833 LOG (GNUNET_ERROR_TYPE_DEBUG, "cancelling trim: %p\n",
3834 t->trim_connections_task);
3835 GNUNET_SCHEDULER_cancel (t->trim_connections_task);
3836 t->trim_connections_task = NULL;
3839 GNUNET_STATISTICS_update (stats, "# tunnels", -1, GNUNET_NO);
3840 GCP_set_tunnel (t->peer, NULL);
3842 if (NULL != t->rekey_task)
3844 GNUNET_SCHEDULER_cancel (t->rekey_task);
3845 t->rekey_task = NULL;
3847 if (NULL != t->kx_ctx)
3849 if (NULL != t->kx_ctx->finish_task)
3850 GNUNET_SCHEDULER_cancel (t->kx_ctx->finish_task);
3851 GNUNET_free (t->kx_ctx);
3862 * @brief Use the given path for the tunnel.
3863 * Update the next and prev hops (and RCs).
3864 * (Re)start the path refresh in case the tunnel is locally owned.
3866 * @param t Tunnel to update.
3867 * @param p Path to use.
3869 * @return Connection created.
3871 struct CadetConnection *
3872 GCT_use_path (struct CadetTunnel *t, struct CadetPeerPath *path)
3874 struct CadetConnection *c;
3875 struct GNUNET_CADET_Hash cid;
3876 unsigned int own_pos;
3878 if (NULL == t || NULL == path)
3884 if (CADET_TUNNEL_SHUTDOWN == t->cstate)
3890 for (own_pos = 0; own_pos < path->length; own_pos++)
3892 if (path->peers[own_pos] == myid)
3895 if (own_pos >= path->length)
3897 GNUNET_break_op (0);
3901 GNUNET_CRYPTO_random_block (GNUNET_CRYPTO_QUALITY_NONCE, &cid, sizeof (cid));
3902 c = GCC_new (&cid, t, path, own_pos);
3905 /* Path was flawed */
3908 GCT_add_connection (t, c);
3914 * Count all created connections of a tunnel. Not necessarily ready connections!
3916 * @param t Tunnel on which to count.
3918 * @return Number of connections created, either being established or ready.
3921 GCT_count_any_connections (struct CadetTunnel *t)
3923 struct CadetTConnection *iter;
3929 for (count = 0, iter = t->connection_head; NULL != iter; iter = iter->next)
3937 * Count established (ready) connections of a tunnel.
3939 * @param t Tunnel on which to count.
3941 * @return Number of connections.
3944 GCT_count_connections (struct CadetTunnel *t)
3946 struct CadetTConnection *iter;
3952 for (count = 0, iter = t->connection_head; NULL != iter; iter = iter->next)
3953 if (CADET_CONNECTION_READY == GCC_get_state (iter->c))
3961 * Count channels of a tunnel.
3963 * @param t Tunnel on which to count.
3965 * @return Number of channels.
3968 GCT_count_channels (struct CadetTunnel *t)
3970 struct CadetTChannel *iter;
3973 for (count = 0, iter = t->channel_head;
3975 iter = iter->next, count++) /* skip */;
3982 * Get the connectivity state of a tunnel.
3986 * @return Tunnel's connectivity state.
3988 enum CadetTunnelCState
3989 GCT_get_cstate (struct CadetTunnel *t)
3994 return (enum CadetTunnelCState) -1;
4001 * Get the encryption state of a tunnel.
4005 * @return Tunnel's encryption state.
4007 enum CadetTunnelEState
4008 GCT_get_estate (struct CadetTunnel *t)
4013 return (enum CadetTunnelEState) -1;
4019 * Get the maximum buffer space for a tunnel towards a local client.
4023 * @return Biggest buffer space offered by any channel in the tunnel.
4026 GCT_get_channels_buffer (struct CadetTunnel *t)
4028 struct CadetTChannel *iter;
4029 unsigned int buffer;
4030 unsigned int ch_buf;
4032 if (NULL == t->channel_head)
4034 /* Probably getting buffer for a channel create/handshake. */
4035 LOG (GNUNET_ERROR_TYPE_DEBUG, " no channels, allow max\n");
4036 return MIN_TUNNEL_BUFFER;
4040 for (iter = t->channel_head; NULL != iter; iter = iter->next)
4042 ch_buf = get_channel_buffer (iter);
4043 if (ch_buf > buffer)
4046 if (MIN_TUNNEL_BUFFER > buffer)
4047 return MIN_TUNNEL_BUFFER;
4049 if (MAX_TUNNEL_BUFFER < buffer)
4052 return MAX_TUNNEL_BUFFER;
4059 * Get the total buffer space for a tunnel for P2P traffic.
4063 * @return Buffer space offered by all connections in the tunnel.
4066 GCT_get_connections_buffer (struct CadetTunnel *t)
4068 struct CadetTConnection *iter;
4069 unsigned int buffer;
4071 if (GNUNET_NO == is_ready (t))
4073 if (count_queued_data (t) >= 3)
4080 for (iter = t->connection_head; NULL != iter; iter = iter->next)
4082 if (GCC_get_state (iter->c) != CADET_CONNECTION_READY)
4086 buffer += get_connection_buffer (iter);
4094 * Get the tunnel's destination.
4098 * @return ID of the destination peer.
4100 const struct GNUNET_PeerIdentity *
4101 GCT_get_destination (struct CadetTunnel *t)
4103 return GCP_get_id (t->peer);
4108 * Get the tunnel's next free global channel ID.
4112 * @return GID of a channel free to use.
4115 GCT_get_next_chid (struct CadetTunnel *t)
4117 CADET_ChannelNumber chid;
4118 CADET_ChannelNumber mask;
4121 /* Set bit 30 depending on the ID relationship. Bit 31 is always 0 for GID.
4122 * If our ID is bigger or loopback tunnel, start at 0, bit 30 = 0
4123 * If peer's ID is bigger, start at 0x4... bit 30 = 1
4125 result = GNUNET_CRYPTO_cmp_peer_identity (&my_full_id, GCP_get_id (t->peer));
4130 t->next_chid |= mask;
4132 while (NULL != GCT_get_channel (t, t->next_chid))
4134 LOG (GNUNET_ERROR_TYPE_DEBUG, "Channel %u exists...\n", t->next_chid);
4135 t->next_chid = (t->next_chid + 1) & ~GNUNET_CADET_LOCAL_CHANNEL_ID_CLI;
4136 t->next_chid |= mask;
4138 chid = t->next_chid;
4139 t->next_chid = (t->next_chid + 1) & ~GNUNET_CADET_LOCAL_CHANNEL_ID_CLI;
4140 t->next_chid |= mask;
4147 * Send ACK on one or more channels due to buffer in connections.
4149 * @param t Channel which has some free buffer space.
4152 GCT_unchoke_channels (struct CadetTunnel *t)
4154 struct CadetTChannel *iter;
4155 unsigned int buffer;
4156 unsigned int channels = GCT_count_channels (t);
4157 unsigned int choked_n;
4158 struct CadetChannel *choked[channels];
4160 LOG (GNUNET_ERROR_TYPE_DEBUG, "GCT_unchoke_channels on %s\n", GCT_2s (t));
4161 LOG (GNUNET_ERROR_TYPE_DEBUG, " head: %p\n", t->channel_head);
4162 if (NULL != t->channel_head)
4163 LOG (GNUNET_ERROR_TYPE_DEBUG, " head ch: %p\n", t->channel_head->ch);
4165 if (NULL != t->tq_head)
4166 send_queued_data (t);
4168 /* Get buffer space */
4169 buffer = GCT_get_connections_buffer (t);
4175 /* Count and remember choked channels */
4177 for (iter = t->channel_head; NULL != iter; iter = iter->next)
4179 if (GNUNET_NO == get_channel_allowed (iter))
4181 choked[choked_n++] = iter->ch;
4185 /* Unchoke random channels */
4186 while (0 < buffer && 0 < choked_n)
4188 unsigned int r = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK,
4190 GCCH_allow_client (choked[r], GCCH_is_origin (choked[r], GNUNET_YES));
4193 choked[r] = choked[choked_n];
4199 * Send ACK on one or more connections due to buffer space to the client.
4201 * Iterates all connections of the tunnel and sends ACKs appropriately.
4206 GCT_send_connection_acks (struct CadetTunnel *t)
4208 struct CadetTConnection *iter;
4211 uint32_t allow_per_connection;
4213 unsigned int buffer;
4215 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel send connection ACKs on %s\n",
4224 if (CADET_TUNNEL_READY != t->cstate)
4227 buffer = GCT_get_channels_buffer (t);
4228 LOG (GNUNET_ERROR_TYPE_DEBUG, " buffer %u\n", buffer);
4230 /* Count connections, how many messages are already allowed */
4231 cs = GCT_count_connections (t);
4232 for (allowed = 0, iter = t->connection_head; NULL != iter; iter = iter->next)
4234 allowed += get_connection_allowed (iter);
4236 LOG (GNUNET_ERROR_TYPE_DEBUG, " allowed %u\n", allowed);
4238 /* Make sure there is no overflow */
4239 if (allowed > buffer)
4242 /* Authorize connections to send more data */
4243 to_allow = buffer - allowed;
4245 for (iter = t->connection_head;
4246 NULL != iter && to_allow > 0;
4249 if (CADET_CONNECTION_READY != GCC_get_state (iter->c)
4250 || get_connection_allowed (iter) > 64 / 3)
4254 allow_per_connection = to_allow/cs;
4255 to_allow -= allow_per_connection;
4257 GCC_allow (iter->c, allow_per_connection,
4258 GCC_is_origin (iter->c, GNUNET_NO));
4263 /* Since we don't allow if it's allowed to send 64/3, this can happen. */
4264 LOG (GNUNET_ERROR_TYPE_DEBUG, " reminding to_allow: %u\n", to_allow);
4270 * Cancel a previously sent message while it's in the queue.
4272 * ONLY can be called before the continuation given to the send function
4273 * is called. Once the continuation is called, the message is no longer in the
4276 * @param q Handle to the queue.
4279 GCT_cancel (struct CadetTunnelQueue *q)
4283 GNUNET_assert (NULL == q->tqd);
4285 /* tun_message_sent() will be called and free q */
4287 else if (NULL != q->tqd)
4289 unqueue_data (q->tqd);
4291 if (NULL != q->cont)
4292 q->cont (q->cont_cls, NULL, q, 0, 0);
4303 * Check if the tunnel has queued traffic.
4305 * @param t Tunnel to check.
4307 * @return #GNUNET_YES if there is queued traffic
4308 * #GNUNET_NO otherwise
4311 GCT_has_queued_traffic (struct CadetTunnel *t)
4313 return (NULL != t->tq_head) ? GNUNET_YES : GNUNET_NO;
4318 * Sends an already built message on a tunnel, encrypting it and
4319 * choosing the best connection if not provided.
4321 * @param message Message to send. Function modifies it.
4322 * @param t Tunnel on which this message is transmitted.
4323 * @param c Connection to use (autoselect if NULL).
4324 * @param force Force the tunnel to take the message (buffer overfill).
4325 * @param cont Continuation to call once message is really sent.
4326 * @param cont_cls Closure for @c cont.
4328 * @return Handle to cancel message. NULL if @c cont is NULL.
4330 struct CadetTunnelQueue *
4331 GCT_send_prebuilt_message (const struct GNUNET_MessageHeader *message,
4332 struct CadetTunnel *t, struct CadetConnection *c,
4333 int force, GCT_sent cont, void *cont_cls)
4335 return send_prebuilt_message (message, t, c, force, cont, cont_cls, NULL);
4340 * Send an Axolotl KX message.
4342 * @param t Tunnel on which to send it.
4343 * @param force_reply Force the other peer to reply with a KX message.
4346 GCT_send_ax_kx (struct CadetTunnel *t, int force_reply)
4348 struct GNUNET_CADET_AX_KX msg;
4349 enum GNUNET_CADET_AX_KX_Flags flags;
4351 LOG (GNUNET_ERROR_TYPE_INFO, "===> AX_KX for %s\n", GCT_2s (t));
4352 if (NULL != t->ephm_h)
4354 LOG (GNUNET_ERROR_TYPE_INFO, " already queued\n");
4358 msg.header.size = htons (sizeof (msg));
4359 msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_AX_KX);
4360 flags = GNUNET_CADET_AX_KX_FLAG_NONE;
4362 flags |= GNUNET_CADET_AX_KX_FLAG_FORCE_REPLY;
4363 msg.flags = htonl (flags);
4364 GNUNET_CRYPTO_ecdhe_key_get_public (t->ax->kx_0, &msg.ephemeral_key);
4365 GNUNET_CRYPTO_ecdhe_key_get_public (t->ax->DHRs, &msg.ratchet_key);
4367 t->ephm_h = send_kx (t, &msg.header);
4368 if (CADET_TUNNEL_KEY_UNINITIALIZED == t->estate)
4369 GCT_change_estate (t, CADET_TUNNEL_KEY_SENT);
4374 * Sends an already built and encrypted message on a tunnel, choosing the best
4375 * connection. Useful for re-queueing messages queued on a destroyed connection.
4377 * @param message Message to send. Function modifies it.
4378 * @param t Tunnel on which this message is transmitted.
4381 GCT_resend_message (const struct GNUNET_MessageHeader *message,
4382 struct CadetTunnel *t)
4384 struct CadetConnection *c;
4387 c = tunnel_get_connection (t);
4390 /* TODO queue in tunnel, marked as encrypted */
4391 LOG (GNUNET_ERROR_TYPE_DEBUG, "No connection available, dropping.\n");
4394 fwd = GCC_is_origin (c, GNUNET_YES);
4395 GNUNET_break (NULL == GCC_send_prebuilt_message (message, 0, 0, c, fwd,
4396 GNUNET_YES, NULL, NULL));
4401 * Is the tunnel directed towards the local peer?
4405 * @return #GNUNET_YES if it is loopback.
4408 GCT_is_loopback (const struct CadetTunnel *t)
4410 return (myid == GCP_get_short_id (t->peer));
4415 * Is the tunnel this path already?
4420 * @return #GNUNET_YES a connection uses this path.
4423 GCT_is_path_used (const struct CadetTunnel *t, const struct CadetPeerPath *p)
4425 struct CadetTConnection *iter;
4427 for (iter = t->connection_head; NULL != iter; iter = iter->next)
4428 if (path_equivalent (GCC_get_path (iter->c), p))
4436 * Get a cost of a path for a tunnel considering existing connections.
4439 * @param path Candidate path.
4441 * @return Cost of the path (path length + number of overlapping nodes)
4444 GCT_get_path_cost (const struct CadetTunnel *t,
4445 const struct CadetPeerPath *path)
4447 struct CadetTConnection *iter;
4448 const struct CadetPeerPath *aux;
4449 unsigned int overlap;
4457 GNUNET_assert (NULL != t);
4459 for (i = 0; i < path->length; i++)
4461 for (iter = t->connection_head; NULL != iter; iter = iter->next)
4463 aux = GCC_get_path (iter->c);
4467 for (j = 0; j < aux->length; j++)
4469 if (path->peers[i] == aux->peers[j])
4477 return path->length + overlap;
4482 * Get the static string for the peer this tunnel is directed.
4486 * @return Static string the destination peer's ID.
4489 GCT_2s (const struct CadetTunnel *t)
4494 return GCP_2s (t->peer);
4498 /******************************************************************************/
4499 /***************************** INFO/DEBUG *******************************/
4500 /******************************************************************************/
4503 ax_debug (const struct CadetTunnelAxolotl *ax, enum GNUNET_ErrorType level)
4505 struct GNUNET_CRYPTO_EcdhePublicKey pub;
4506 struct CadetTunnelSkippedKey *iter;
4508 LOG2 (level, "TTT RK \t %s\n",
4509 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &ax->RK));
4511 LOG2 (level, "TTT HKs \t %s\n",
4512 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &ax->HKs));
4513 LOG2 (level, "TTT HKr \t %s\n",
4514 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &ax->HKr));
4515 LOG2 (level, "TTT NHKs\t %s\n",
4516 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &ax->NHKs));
4517 LOG2 (level, "TTT NHKr\t %s\n",
4518 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &ax->NHKr));
4520 LOG2 (level, "TTT CKs \t %s\n",
4521 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &ax->CKs));
4522 LOG2 (level, "TTT CKr \t %s\n",
4523 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &ax->CKr));
4525 GNUNET_CRYPTO_ecdhe_key_get_public (ax->DHRs, &pub);
4526 LOG2 (level, "TTT DHRs\t %s\n",
4527 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &pub));
4528 LOG2 (level, "TTT DHRr\t %s\n",
4529 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &ax->DHRr));
4531 LOG2 (level, "TTT Nr\t %u\tNs\t%u\n", ax->Nr, ax->Ns);
4532 LOG2 (level, "TTT PNs\t %u\tSkipped\t%u\n", ax->PNs, ax->skipped);
4533 LOG2 (level, "TTT Ratchet\t%u\n", ax->ratchet_flag);
4535 for (iter = ax->skipped_head; NULL != iter; iter = iter->next)
4537 LOG2 (level, "TTT HK\t %s\n",
4538 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &iter->HK));
4539 LOG2 (level, "TTT MK\t %s\n",
4540 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &iter->MK));
4545 * Log all possible info about the tunnel state.
4547 * @param t Tunnel to debug.
4548 * @param level Debug level to use.
4551 GCT_debug (const struct CadetTunnel *t, enum GNUNET_ErrorType level)
4553 struct CadetTChannel *iterch;
4554 struct CadetTConnection *iterc;
4557 do_log = GNUNET_get_log_call_status (level & (~GNUNET_ERROR_TYPE_BULK),
4559 __FILE__, __FUNCTION__, __LINE__);
4563 LOG2 (level, "TTT DEBUG TUNNEL TOWARDS %s\n", GCT_2s (t));
4564 LOG2 (level, "TTT cstate %s, estate %s\n",
4565 cstate2s (t->cstate), estate2s (t->estate));
4566 LOG2 (level, "TTT kx_ctx %p, rekey_task %u, finish task %u\n",
4567 t->kx_ctx, t->rekey_task, t->kx_ctx ? t->kx_ctx->finish_task : 0);
4568 #if DUMP_KEYS_TO_STDERR
4569 if (CADET_Axolotl == t->enc_type)
4571 ax_debug (t->ax, level);
4575 LOG2 (level, "TTT my EPHM\t %s\n",
4576 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &otr_kx_msg.ephemeral_key));
4577 LOG2 (level, "TTT peers EPHM:\t %s\n",
4578 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &t->peers_ephemeral_key));
4579 LOG2 (level, "TTT ENC key:\t %s\n",
4580 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &t->e_key));
4581 LOG2 (level, "TTT DEC key:\t %s\n",
4582 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &t->d_key));
4585 LOG2 (level, "TTT OLD ENC key:\t %s\n",
4586 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &t->kx_ctx->e_key_old));
4587 LOG2 (level, "TTT OLD DEC key:\t %s\n",
4588 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &t->kx_ctx->d_key_old));
4592 LOG2 (level, "TTT tq_head %p, tq_tail %p\n", t->tq_head, t->tq_tail);
4593 LOG2 (level, "TTT destroy %p\n", t->destroy_task);
4595 LOG2 (level, "TTT channels:\n");
4596 for (iterch = t->channel_head; NULL != iterch; iterch = iterch->next)
4598 GCCH_debug (iterch->ch, level);
4601 LOG2 (level, "TTT connections:\n");
4602 for (iterc = t->connection_head; NULL != iterc; iterc = iterc->next)
4604 GCC_debug (iterc->c, level);
4607 LOG2 (level, "TTT DEBUG TUNNEL END\n");
4612 * Iterate all tunnels.
4614 * @param iter Iterator.
4615 * @param cls Closure for @c iter.
4618 GCT_iterate_all (GNUNET_CONTAINER_PeerMapIterator iter, void *cls)
4620 GNUNET_CONTAINER_multipeermap_iterate (tunnels, iter, cls);
4625 * Count all tunnels.
4627 * @return Number of tunnels to remote peers kept by this peer.
4630 GCT_count_all (void)
4632 return GNUNET_CONTAINER_multipeermap_size (tunnels);
4637 * Iterate all connections of a tunnel.
4639 * @param t Tunnel whose connections to iterate.
4640 * @param iter Iterator.
4641 * @param cls Closure for @c iter.
4644 GCT_iterate_connections (struct CadetTunnel *t, GCT_conn_iter iter, void *cls)
4646 struct CadetTConnection *ct;
4648 for (ct = t->connection_head; NULL != ct; ct = ct->next)
4654 * Iterate all channels of a tunnel.
4656 * @param t Tunnel whose channels to iterate.
4657 * @param iter Iterator.
4658 * @param cls Closure for @c iter.
4661 GCT_iterate_channels (struct CadetTunnel *t, GCT_chan_iter iter, void *cls)
4663 struct CadetTChannel *cht;
4665 for (cht = t->channel_head; NULL != cht; cht = cht->next)
4666 iter (cls, cht->ch);