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;
1340 struct GNUNET_CRYPTO_SymmetricSessionKey *valid_HK;
1346 LOG (GNUNET_ERROR_TYPE_DEBUG, "Trying old keys\n");
1347 hmac = &plaintext_header.hmac;
1348 esize = size - sizeof (struct GNUNET_CADET_AX);
1350 /* Find a correct Header Key */
1351 for (key = t->ax->skipped_head; NULL != key; key = key->next)
1353 #if DUMP_KEYS_TO_STDERR
1354 LOG (GNUNET_ERROR_TYPE_DEBUG, " Trying hmac with key %s\n",
1355 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &key->HK));
1357 t_hmac (&src->Ns, AX_HEADER_SIZE + esize, 0, &key->HK, hmac);
1358 if (0 == memcmp (hmac, &src->hmac, sizeof (*hmac)))
1360 LOG (GNUNET_ERROR_TYPE_DEBUG, " hmac correct\n");
1361 valid_HK = &key->HK;
1368 /* Should've been checked in -cadet_connection.c handle_cadet_encrypted. */
1369 GNUNET_assert (size > sizeof (struct GNUNET_CADET_AX));
1370 len = size - sizeof (struct GNUNET_CADET_AX);
1371 GNUNET_assert (len >= sizeof (struct GNUNET_MessageHeader));
1373 /* Decrypt header */
1374 GNUNET_CRYPTO_symmetric_derive_iv (&iv, &key->HK, NULL, 0, NULL);
1375 res = GNUNET_CRYPTO_symmetric_decrypt (&src->Ns, AX_HEADER_SIZE,
1376 &key->HK, &iv, &plaintext_header.Ns);
1377 GNUNET_assert (AX_HEADER_SIZE == res);
1378 LOG (GNUNET_ERROR_TYPE_DEBUG, " Message %u, previous: %u\n",
1379 ntohl (plaintext_header.Ns), ntohl (plaintext_header.PNs));
1381 /* Find the correct Message Key */
1382 N = ntohl (plaintext_header.Ns);
1383 while (NULL != key && N != key->Kn)
1385 if (NULL == key || 0 != memcmp (&key->HK, valid_HK, sizeof (*valid_HK)))
1388 #if DUMP_KEYS_TO_STDERR
1389 LOG (GNUNET_ERROR_TYPE_INFO, " AX_DEC_H with skipped key %s\n",
1390 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &key->HK));
1391 LOG (GNUNET_ERROR_TYPE_INFO, " AX_DEC with skipped key %u: %s\n",
1392 key->Kn, GNUNET_i2s ((struct GNUNET_PeerIdentity *) &key->MK));
1395 /* Decrypt payload */
1396 GNUNET_CRYPTO_symmetric_derive_iv (&iv, &key->MK, NULL, 0, NULL);
1397 res = GNUNET_CRYPTO_symmetric_decrypt (&src[1], len, &key->MK, &iv, dst);
1400 GNUNET_CONTAINER_DLL_remove (t->ax->skipped_head, t->ax->skipped_tail, key);
1402 GNUNET_free (key); /* GNUNET_free overwrites memory with 0xbaadf00d */
1409 * Delete a key from the list of skipped keys.
1411 * @param t Tunnel to delete from.
1412 * @param HKr Header Key to use.
1415 store_skipped_key (struct CadetTunnel *t,
1416 const struct GNUNET_CRYPTO_SymmetricSessionKey *HKr)
1418 struct CadetTunnelSkippedKey *key;
1420 key = GNUNET_new (struct CadetTunnelSkippedKey);
1421 key->timestamp = GNUNET_TIME_absolute_get ();
1422 key->Kn = t->ax->Nr;
1423 key->HK = t->ax->HKr;
1424 t_hmac_derive_key (&t->ax->CKr, &key->MK, "0", 1);
1425 #if DUMP_KEYS_TO_STDERR
1426 LOG (GNUNET_ERROR_TYPE_INFO, " storing MK for Nr %u: %s\n",
1427 key->Kn, GNUNET_i2s ((struct GNUNET_PeerIdentity *) &key->MK));
1428 LOG (GNUNET_ERROR_TYPE_INFO, " for CKr: %s\n",
1429 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &t->ax->CKr));
1431 t_hmac_derive_key (&t->ax->CKr, &t->ax->CKr, "1", 1);
1432 GNUNET_CONTAINER_DLL_insert (t->ax->skipped_head, t->ax->skipped_tail, key);
1439 * Delete a key from the list of skipped keys.
1441 * @param t Tunnel to delete from.
1442 * @param key Key to delete.
1445 delete_skipped_key (struct CadetTunnel *t, struct CadetTunnelSkippedKey *key)
1447 GNUNET_CONTAINER_DLL_remove (t->ax->skipped_head, t->ax->skipped_tail, key);
1454 * Stage skipped AX keys and calculate the message key.
1456 * Stores each HK and MK for skipped messages.
1458 * @param t Tunnel where to stage the keys.
1459 * @param HKr Header key.
1460 * @param Np Received meesage number.
1462 * @return GNUNET_OK if keys were stored.
1463 * GNUNET_SYSERR if an error ocurred (Np not expected).
1466 store_ax_keys (struct CadetTunnel *t,
1467 const struct GNUNET_CRYPTO_SymmetricSessionKey *HKr,
1473 gap = Np - t->ax->Nr;
1474 if (MAX_KEY_GAP < gap)
1476 /* Avoid DoS (forcing peer to do 2*33 chain HMAC operations) */
1477 /* TODO: start new key exchange on return */
1478 GNUNET_break_op (0);
1479 LOG (GNUNET_ERROR_TYPE_WARNING, "Got message %u, expected %u+\n",
1481 return GNUNET_SYSERR;
1485 /* Delayed message: don't store keys, flag to try old keys. */
1486 return GNUNET_SYSERR;
1489 while (t->ax->Nr < Np)
1490 store_skipped_key (t, HKr);
1492 while (t->ax->skipped > MAX_SKIPPED_KEYS)
1493 delete_skipped_key (t, t->ax->skipped_tail);
1500 * Decrypt and verify data with the appropriate tunnel key and verify that the
1501 * data has not been altered since it was sent by the remote peer.
1503 * @param t Tunnel whose key to use.
1504 * @param dst Destination for the plaintext.
1505 * @param src Source of the message. Can overlap with @c dst.
1506 * @param size Size of the message.
1508 * @return Size of the decrypted data, -1 if an error was encountered.
1511 t_ax_decrypt_and_validate (struct CadetTunnel *t, void *dst,
1512 const struct GNUNET_CADET_AX *src, size_t size)
1514 struct CadetTunnelAxolotl *ax;
1515 struct GNUNET_CADET_Hash msg_hmac;
1516 struct GNUNET_HashCode hmac;
1517 struct GNUNET_CADET_AX plaintext_header;
1524 esize = size - sizeof (struct GNUNET_CADET_AX);
1529 /* Try current HK */
1530 t_hmac (&src->Ns, AX_HEADER_SIZE + esize, 0, &ax->HKr, &msg_hmac);
1531 if (0 != memcmp (&msg_hmac, &src->hmac, sizeof (msg_hmac)))
1533 static const char ctx[] = "axolotl ratchet";
1534 struct GNUNET_CRYPTO_SymmetricSessionKey keys[3]; /* RKp, NHKp, CKp */
1535 struct GNUNET_CRYPTO_SymmetricSessionKey HK;
1536 struct GNUNET_HashCode dh;
1537 struct GNUNET_CRYPTO_EcdhePublicKey *DHRp;
1540 t_hmac (&src->Ns, AX_HEADER_SIZE + esize, 0, &ax->NHKr, &msg_hmac);
1541 if (0 != memcmp (&msg_hmac, &src->hmac, sizeof (msg_hmac)))
1543 /* Try the skipped keys, if that fails, we're out of luck. */
1544 return try_old_ax_keys (t, dst, src, size);
1546 LOG (GNUNET_ERROR_TYPE_INFO, "next HK worked\n");
1550 t_h_decrypt (t, src, &plaintext_header);
1551 Np = ntohl (plaintext_header.Ns);
1552 PNp = ntohl (plaintext_header.PNs);
1553 DHRp = &plaintext_header.DHRs;
1554 store_ax_keys (t, &HK, PNp);
1556 /* RKp, NHKp, CKp = KDF (HMAC-HASH (RK, DH (DHRp, DHRs))) */
1557 GNUNET_CRYPTO_ecc_ecdh (ax->DHRs, DHRp, &dh);
1558 t_ax_hmac_hash (&ax->RK, &hmac, &dh, sizeof (dh));
1559 GNUNET_CRYPTO_kdf (keys, sizeof (keys), ctx, sizeof (ctx),
1560 &hmac, sizeof (hmac), NULL);
1562 /* Commit "purported" keys */
1568 ax->ratchet_allowed = GNUNET_YES;
1572 LOG (GNUNET_ERROR_TYPE_DEBUG, "current HK\n");
1573 t_h_decrypt (t, src, &plaintext_header);
1574 Np = ntohl (plaintext_header.Ns);
1575 PNp = ntohl (plaintext_header.PNs);
1577 LOG (GNUNET_ERROR_TYPE_INFO, " got AX Nr %u\n", Np);
1579 if (GNUNET_OK != store_ax_keys (t, &ax->HKr, Np))
1580 /* Try the skipped keys, if that fails, we're out of luck. */
1581 return try_old_ax_keys (t, dst, src, size);
1583 osize = t_ax_decrypt (t, dst, &src[1], esize);
1588 GNUNET_break_op (0);
1597 * Create key material by doing ECDH on the local and remote ephemeral keys.
1599 * @param key_material Where to store the key material.
1600 * @param ephemeral Peer's public ephemeral key.
1602 * @return GNUNET_OK if it went fine, GNUNET_SYSERR otherwise.
1605 derive_otr_key_material (struct GNUNET_HashCode *key_material,
1606 const struct GNUNET_CRYPTO_EcdhePublicKey *ephemeral)
1609 GNUNET_CRYPTO_ecc_ecdh (otr_ephemeral_key, ephemeral, key_material))
1612 return GNUNET_SYSERR;
1619 * Create a symmetic key from the identities of both ends and the key material
1622 * @param key Destination for the generated key.
1623 * @param sender ID of the peer that will encrypt with @c key.
1624 * @param receiver ID of the peer that will decrypt with @c key.
1625 * @param key_material Hash created with ECDH with the ephemeral keys.
1628 derive_symmertic (struct GNUNET_CRYPTO_SymmetricSessionKey *key,
1629 const struct GNUNET_PeerIdentity *sender,
1630 const struct GNUNET_PeerIdentity *receiver,
1631 const struct GNUNET_HashCode *key_material)
1633 const char salt[] = "CADET kx salt";
1635 GNUNET_CRYPTO_kdf (key, sizeof (struct GNUNET_CRYPTO_SymmetricSessionKey),
1636 salt, sizeof (salt),
1637 key_material, sizeof (struct GNUNET_HashCode),
1638 sender, sizeof (struct GNUNET_PeerIdentity),
1639 receiver, sizeof (struct GNUNET_PeerIdentity),
1645 * Derive the tunnel's keys using our own and the peer's ephemeral keys.
1647 * @param t Tunnel for which to create the keys.
1649 * @return GNUNET_OK if successful, GNUNET_SYSERR otherwise.
1652 create_otr_keys (struct CadetTunnel *t)
1654 struct GNUNET_HashCode km;
1656 if (GNUNET_OK != derive_otr_key_material (&km, &t->peers_ephemeral_key))
1657 return GNUNET_SYSERR;
1658 derive_symmertic (&t->e_key, &my_full_id, GCP_get_id (t->peer), &km);
1659 derive_symmertic (&t->d_key, GCP_get_id (t->peer), &my_full_id, &km);
1660 #if DUMP_KEYS_TO_STDERR
1661 LOG (GNUNET_ERROR_TYPE_INFO, "ME: %s\n",
1662 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &otr_kx_msg.ephemeral_key));
1663 LOG (GNUNET_ERROR_TYPE_INFO, "PE: %s\n",
1664 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &t->peers_ephemeral_key));
1665 LOG (GNUNET_ERROR_TYPE_INFO, "KM: %s\n", GNUNET_h2s (&km));
1666 LOG (GNUNET_ERROR_TYPE_INFO, "EK: %s\n",
1667 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &t->e_key));
1668 LOG (GNUNET_ERROR_TYPE_INFO, "DK: %s\n",
1669 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &t->d_key));
1676 * Create a new Key eXchange context for the tunnel.
1678 * If the old keys were verified, keep them for old traffic. Create a new KX
1679 * timestamp and a new nonce.
1681 * @param t Tunnel for which to create the KX ctx.
1683 * @return GNUNET_OK if successful, GNUNET_SYSERR otherwise.
1686 create_kx_ctx (struct CadetTunnel *t)
1688 LOG (GNUNET_ERROR_TYPE_INFO, " new kx ctx for %s\n", GCT_2s (t));
1690 if (NULL != t->kx_ctx)
1692 if (NULL != t->kx_ctx->finish_task)
1694 LOG (GNUNET_ERROR_TYPE_INFO, " resetting exisiting finish task\n");
1695 GNUNET_SCHEDULER_cancel (t->kx_ctx->finish_task);
1696 t->kx_ctx->finish_task = NULL;
1701 t->kx_ctx = GNUNET_new (struct CadetTunnelKXCtx);
1702 t->kx_ctx->challenge = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE,
1706 if (CADET_TUNNEL_KEY_OK == t->estate)
1708 LOG (GNUNET_ERROR_TYPE_INFO, " backing up keys\n");
1709 t->kx_ctx->d_key_old = t->d_key;
1710 t->kx_ctx->e_key_old = t->e_key;
1713 LOG (GNUNET_ERROR_TYPE_INFO, " old keys not valid, not saving\n");
1714 t->kx_ctx->rekey_start_time = GNUNET_TIME_absolute_get ();
1715 return create_otr_keys (t);
1720 * @brief Finish the Key eXchange and destroy the old keys.
1722 * @param cls Closure (Tunnel for which to finish the KX).
1723 * @param tc Task context.
1726 finish_kx (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
1728 struct CadetTunnel *t = cls;
1730 LOG (GNUNET_ERROR_TYPE_INFO, "finish KX for %s\n", GCT_2s (t));
1732 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
1734 LOG (GNUNET_ERROR_TYPE_INFO, " shutdown\n");
1738 GNUNET_free (t->kx_ctx);
1744 * Destroy a Key eXchange context for the tunnel. This function only schedules
1745 * the destruction, the freeing of the memory (and clearing of old key material)
1746 * happens after a delay!
1748 * @param t Tunnel whose KX ctx to destroy.
1751 destroy_kx_ctx (struct CadetTunnel *t)
1753 struct GNUNET_TIME_Relative delay;
1755 if (NULL == t->kx_ctx || NULL != t->kx_ctx->finish_task)
1758 if (is_key_null (&t->kx_ctx->e_key_old))
1760 t->kx_ctx->finish_task = GNUNET_SCHEDULER_add_now (finish_kx, t);
1764 delay = GNUNET_TIME_relative_divide (rekey_period, 4);
1765 delay = GNUNET_TIME_relative_min (delay, GNUNET_TIME_UNIT_MINUTES);
1767 t->kx_ctx->finish_task = GNUNET_SCHEDULER_add_delayed (delay, finish_kx, t);
1773 * Pick a connection on which send the next data message.
1775 * @param t Tunnel on which to send the message.
1777 * @return The connection on which to send the next message.
1779 static struct CadetConnection *
1780 tunnel_get_connection (struct CadetTunnel *t)
1782 struct CadetTConnection *iter;
1783 struct CadetConnection *best;
1785 unsigned int lowest_q;
1787 LOG (GNUNET_ERROR_TYPE_DEBUG, "tunnel_get_connection %s\n", GCT_2s (t));
1789 lowest_q = UINT_MAX;
1790 for (iter = t->connection_head; NULL != iter; iter = iter->next)
1792 LOG (GNUNET_ERROR_TYPE_DEBUG, " connection %s: %u\n",
1793 GCC_2s (iter->c), GCC_get_state (iter->c));
1794 if (CADET_CONNECTION_READY == GCC_get_state (iter->c))
1796 qn = GCC_get_qn (iter->c, GCC_is_origin (iter->c, GNUNET_YES));
1797 LOG (GNUNET_ERROR_TYPE_DEBUG, " q_n %u, \n", qn);
1805 LOG (GNUNET_ERROR_TYPE_DEBUG, " selected: connection %s\n", GCC_2s (best));
1811 * Callback called when a queued message is sent.
1813 * Calculates the average time and connection packet tracking.
1815 * @param cls Closure (TunnelQueue handle).
1816 * @param c Connection this message was on.
1817 * @param q Connection queue handle (unused).
1818 * @param type Type of message sent.
1819 * @param fwd Was this a FWD going message?
1820 * @param size Size of the message.
1823 tun_message_sent (void *cls,
1824 struct CadetConnection *c,
1825 struct CadetConnectionQueue *q,
1826 uint16_t type, int fwd, size_t size)
1828 struct CadetTunnelQueue *qt = cls;
1829 struct CadetTunnel *t;
1831 LOG (GNUNET_ERROR_TYPE_DEBUG, "tun_message_sent\n");
1833 GNUNET_assert (NULL != qt->cont);
1834 t = NULL == c ? NULL : GCC_get_tunnel (c);
1835 qt->cont (qt->cont_cls, t, qt, type, size);
1841 count_queued_data (const struct CadetTunnel *t)
1843 struct CadetTunnelDelayed *iter;
1846 for (count = 0, iter = t->tq_head; iter != NULL; iter = iter->next)
1853 * Delete a queued message: either was sent or the channel was destroyed
1854 * before the tunnel's key exchange had a chance to finish.
1856 * @param tqd Delayed queue handle.
1859 unqueue_data (struct CadetTunnelDelayed *tqd)
1861 GNUNET_CONTAINER_DLL_remove (tqd->t->tq_head, tqd->t->tq_tail, tqd);
1867 * Cache a message to be sent once tunnel is online.
1869 * @param t Tunnel to hold the message.
1870 * @param msg Message itself (copy will be made).
1872 static struct CadetTunnelDelayed *
1873 queue_data (struct CadetTunnel *t, const struct GNUNET_MessageHeader *msg)
1875 struct CadetTunnelDelayed *tqd;
1876 uint16_t size = ntohs (msg->size);
1878 LOG (GNUNET_ERROR_TYPE_DEBUG, "queue data on Tunnel %s\n", GCT_2s (t));
1880 GNUNET_assert (GNUNET_NO == is_ready (t));
1882 tqd = GNUNET_malloc (sizeof (struct CadetTunnelDelayed) + size);
1885 memcpy (&tqd[1], msg, size);
1886 GNUNET_CONTAINER_DLL_insert_tail (t->tq_head, t->tq_tail, tqd);
1892 * Sends an already built message on a tunnel, encrypting it and
1893 * choosing the best connection.
1895 * @param message Message to send. Function modifies it.
1896 * @param t Tunnel on which this message is transmitted.
1897 * @param c Connection to use (autoselect if NULL).
1898 * @param force Force the tunnel to take the message (buffer overfill).
1899 * @param cont Continuation to call once message is really sent.
1900 * @param cont_cls Closure for @c cont.
1901 * @param existing_q In case this a transmission of previously queued data,
1902 * this should be TunnelQueue given to the client.
1905 * @return Handle to cancel message.
1906 * NULL if @c cont is NULL or an error happens and message is dropped.
1908 static struct CadetTunnelQueue *
1909 send_prebuilt_message (const struct GNUNET_MessageHeader *message,
1910 struct CadetTunnel *t, struct CadetConnection *c,
1911 int force, GCT_sent cont, void *cont_cls,
1912 struct CadetTunnelQueue *existing_q)
1914 struct GNUNET_MessageHeader *msg;
1915 struct GNUNET_CADET_Encrypted *otr_msg;
1916 struct GNUNET_CADET_AX *ax_msg;
1917 struct CadetTunnelQueue *tq;
1918 size_t size = ntohs (message->size);
1919 const uint16_t max_overhead = sizeof (struct GNUNET_CADET_Encrypted)
1920 + sizeof (struct GNUNET_CADET_AX);
1921 char cbuf[max_overhead + size];
1928 LOG (GNUNET_ERROR_TYPE_DEBUG, "GMT Send on Tunnel %s\n", GCT_2s (t));
1930 if (GNUNET_NO == is_ready (t))
1932 struct CadetTunnelDelayed *tqd;
1933 /* A non null existing_q indicates sending of queued data.
1934 * Should only happen after tunnel becomes ready.
1936 GNUNET_assert (NULL == existing_q);
1937 tqd = queue_data (t, message);
1940 tq = GNUNET_new (struct CadetTunnelQueue);
1944 tq->cont_cls = cont_cls;
1948 GNUNET_assert (GNUNET_NO == GCT_is_loopback (t));
1950 if (CADET_Axolotl == t->enc_type)
1952 ax_msg = (struct GNUNET_CADET_AX *) cbuf;
1953 msg = &ax_msg->header;
1954 msg->size = htons (sizeof (struct GNUNET_CADET_AX) + size);
1955 msg->type = htons (GNUNET_MESSAGE_TYPE_CADET_AX);
1956 ax_msg->reserved = 0;
1957 esize = t_ax_encrypt (t, &ax_msg[1], message, size);
1958 ax_msg->Ns = htonl (t->ax->Ns++);
1959 ax_msg->PNs = htonl (t->ax->PNs);
1960 GNUNET_CRYPTO_ecdhe_key_get_public (t->ax->DHRs, &ax_msg->DHRs);
1961 t_h_encrypt (t, ax_msg);
1962 t_hmac (&ax_msg->Ns, AX_HEADER_SIZE + esize, 0, &t->ax->HKs, &ax_msg->hmac);
1966 otr_msg = (struct GNUNET_CADET_Encrypted *) cbuf;
1967 msg = &otr_msg->header;
1968 iv = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX);
1970 esize = t_encrypt (t, &otr_msg[1], message, size, iv, GNUNET_NO);
1971 t_hmac (&otr_msg[1], size, iv, select_key (t), &otr_msg->hmac);
1972 msg->size = htons (sizeof (struct GNUNET_CADET_Encrypted) + size);
1973 msg->type = htons (GNUNET_MESSAGE_TYPE_CADET_ENCRYPTED);
1974 otr_msg->ttl = htonl (default_ttl);
1976 GNUNET_assert (esize == size);
1979 c = tunnel_get_connection (t);
1982 /* Why is tunnel 'ready'? Should have been queued! */
1983 if (NULL != t->destroy_task)
1986 GCT_debug (t, GNUNET_ERROR_TYPE_WARNING);
1988 return NULL; /* Drop... */
1992 type = ntohs (message->type);
1995 case GNUNET_MESSAGE_TYPE_CADET_DATA:
1996 case GNUNET_MESSAGE_TYPE_CADET_DATA_ACK:
1997 if (GNUNET_MESSAGE_TYPE_CADET_DATA == type)
1998 mid = ntohl (((struct GNUNET_CADET_Data *) message)->mid);
2000 mid = ntohl (((struct GNUNET_CADET_DataACK *) message)->mid);
2002 case GNUNET_MESSAGE_TYPE_CADET_KEEPALIVE:
2003 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_CREATE:
2004 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_DESTROY:
2005 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_ACK:
2006 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_NACK:
2010 LOG (GNUNET_ERROR_TYPE_ERROR, "type %s not valid\n", GC_m2s (type));
2012 LOG (GNUNET_ERROR_TYPE_DEBUG, "type %s\n", GC_m2s (type));
2014 fwd = GCC_is_origin (c, GNUNET_YES);
2018 GNUNET_break (NULL == GCC_send_prebuilt_message (msg, type, mid, c, fwd,
2019 force, NULL, NULL));
2022 if (NULL == existing_q)
2024 tq = GNUNET_new (struct CadetTunnelQueue); /* FIXME valgrind: leak*/
2031 tq->cq = GCC_send_prebuilt_message (msg, type, mid, c, fwd, force,
2032 &tun_message_sent, tq);
2033 GNUNET_assert (NULL != tq->cq);
2035 tq->cont_cls = cont_cls;
2042 * Send all cached messages that we can, tunnel is online.
2044 * @param t Tunnel that holds the messages. Cannot be loopback.
2047 send_queued_data (struct CadetTunnel *t)
2049 struct CadetTunnelDelayed *tqd;
2050 struct CadetTunnelDelayed *next;
2053 LOG (GNUNET_ERROR_TYPE_INFO, "Send queued data, tunnel %s\n", GCT_2s (t));
2055 if (GCT_is_loopback (t))
2061 if (GNUNET_NO == is_ready (t))
2063 LOG (GNUNET_ERROR_TYPE_WARNING, " not ready yet: %s/%s\n",
2064 estate2s (t->estate), cstate2s (t->cstate));
2068 room = GCT_get_connections_buffer (t);
2069 LOG (GNUNET_ERROR_TYPE_DEBUG, " buffer space: %u\n", room);
2070 LOG (GNUNET_ERROR_TYPE_DEBUG, " tq head: %p\n", t->tq_head);
2071 for (tqd = t->tq_head; NULL != tqd && room > 0; tqd = next)
2073 LOG (GNUNET_ERROR_TYPE_DEBUG, " sending queued data\n");
2076 send_prebuilt_message ((struct GNUNET_MessageHeader *) &tqd[1],
2077 tqd->t, NULL, GNUNET_YES,
2078 NULL != tqd->tq ? tqd->tq->cont : NULL,
2079 NULL != tqd->tq ? tqd->tq->cont_cls : NULL,
2083 LOG (GNUNET_ERROR_TYPE_DEBUG, "GCT_send_queued_data end\n", GCP_2s (t->peer));
2088 * @brief Resend the AX KX until we complete the handshake.
2090 * @param cls Closure (tunnel).
2091 * @param tc Task context.
2094 ax_kx_resend (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
2096 struct CadetTunnel *t = cls;
2098 t->rekey_task = NULL;
2100 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
2103 if (CADET_TUNNEL_KEY_OK == t->estate)
2105 /* Should have been canceled on estate change */
2110 GCT_send_ax_kx (t, GNUNET_YES);
2115 * Callback called when a queued message is sent.
2117 * @param cls Closure.
2118 * @param c Connection this message was on.
2119 * @param type Type of message sent.
2120 * @param fwd Was this a FWD going message?
2121 * @param size Size of the message.
2124 ephm_sent (void *cls,
2125 struct CadetConnection *c,
2126 struct CadetConnectionQueue *q,
2127 uint16_t type, int fwd, size_t size)
2129 struct CadetTunnel *t = cls;
2130 LOG (GNUNET_ERROR_TYPE_DEBUG, "ephemeral sent %s\n", GC_m2s (type));
2134 if (CADET_TUNNEL_KEY_OK == t->estate)
2137 if (CADET_Axolotl == t->enc_type)
2139 if (NULL != t->rekey_task)
2142 GCT_debug (t, GNUNET_ERROR_TYPE_WARNING);
2143 GNUNET_SCHEDULER_cancel (t->rekey_task);
2145 t->rekey_task = GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_SECONDS,
2152 * Callback called when a queued message is sent.
2154 * @param cls Closure.
2155 * @param c Connection this message was on.
2156 * @param type Type of message sent.
2157 * @param fwd Was this a FWD going message?
2158 * @param size Size of the message.
2161 pong_sent (void *cls,
2162 struct CadetConnection *c,
2163 struct CadetConnectionQueue *q,
2164 uint16_t type, int fwd, size_t size)
2166 struct CadetTunnel *t = cls;
2167 LOG (GNUNET_ERROR_TYPE_DEBUG, "pong_sent %s\n", GC_m2s (type));
2174 * Sends key exchange message on a tunnel, choosing the best connection.
2175 * Should not be called on loopback tunnels.
2177 * @param t Tunnel on which this message is transmitted.
2178 * @param message Message to send. Function modifies it.
2180 * @return Handle to the message in the connection queue.
2182 static struct CadetConnectionQueue *
2183 send_kx (struct CadetTunnel *t,
2184 const struct GNUNET_MessageHeader *message)
2186 struct CadetConnection *c;
2187 struct GNUNET_CADET_KX *msg;
2188 size_t size = ntohs (message->size);
2189 char cbuf[sizeof (struct GNUNET_CADET_KX) + size];
2194 LOG (GNUNET_ERROR_TYPE_DEBUG, "GMT KX on Tunnel %s\n", GCT_2s (t));
2196 /* Avoid loopback. */
2197 if (GCT_is_loopback (t))
2202 type = ntohs (message->type);
2204 /* Even if tunnel is "being destroyed", send anyway.
2205 * Could be a response to a rekey initiated by remote peer,
2206 * who is trying to create a new channel!
2209 /* Must have a connection, or be looking for one. */
2210 if (NULL == t->connection_head)
2212 LOG (GNUNET_ERROR_TYPE_DEBUG, "%s with no connection\n", GC_m2s (type));
2213 if (CADET_TUNNEL_SEARCHING != t->cstate)
2216 GCT_debug (t, GNUNET_ERROR_TYPE_ERROR);
2217 GCP_debug (t->peer, GNUNET_ERROR_TYPE_ERROR);
2222 msg = (struct GNUNET_CADET_KX *) cbuf;
2223 msg->header.type = htons (GNUNET_MESSAGE_TYPE_CADET_KX);
2224 msg->header.size = htons (sizeof (struct GNUNET_CADET_KX) + size);
2225 c = tunnel_get_connection (t);
2228 if (NULL == t->destroy_task && CADET_TUNNEL_READY == t->cstate)
2231 GCT_debug (t, GNUNET_ERROR_TYPE_ERROR);
2237 case GNUNET_MESSAGE_TYPE_CADET_KX_EPHEMERAL:
2238 case GNUNET_MESSAGE_TYPE_CADET_AX_KX:
2239 GNUNET_assert (NULL == t->ephm_h);
2242 case GNUNET_MESSAGE_TYPE_CADET_KX_PONG:
2243 GNUNET_assert (NULL == t->pong_h);
2248 LOG (GNUNET_ERROR_TYPE_DEBUG, "unkown type %s\n", GC_m2s (type));
2251 memcpy (&msg[1], message, size);
2253 fwd = GCC_is_origin (c, GNUNET_YES);
2255 return GCC_send_prebuilt_message (&msg->header, type, 0, c,
2262 * Send the ephemeral key on a tunnel.
2264 * @param t Tunnel on which to send the key.
2267 send_ephemeral (struct CadetTunnel *t)
2269 LOG (GNUNET_ERROR_TYPE_INFO, "===> EPHM for %s\n", GCT_2s (t));
2270 if (NULL != t->ephm_h)
2272 LOG (GNUNET_ERROR_TYPE_INFO, " already queued\n");
2276 otr_kx_msg.sender_status = htonl (t->estate);
2277 otr_kx_msg.iv = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX);
2278 otr_kx_msg.nonce = t->kx_ctx->challenge;
2279 LOG (GNUNET_ERROR_TYPE_DEBUG, " send nonce c %u\n", otr_kx_msg.nonce);
2280 t_encrypt (t, &otr_kx_msg.nonce, &otr_kx_msg.nonce,
2281 ping_encryption_size(), otr_kx_msg.iv, GNUNET_YES);
2282 LOG (GNUNET_ERROR_TYPE_DEBUG, " send nonce e %u\n", otr_kx_msg.nonce);
2283 t->ephm_h = send_kx (t, &otr_kx_msg.header);
2288 * Send a pong message on a tunnel.
2290 * @param t Tunnel on which to send the pong.
2291 * @param challenge Value sent in the ping that we have to send back.
2294 send_pong (struct CadetTunnel *t, uint32_t challenge)
2296 struct GNUNET_CADET_KX_Pong msg;
2298 LOG (GNUNET_ERROR_TYPE_INFO, "===> PONG for %s\n", GCT_2s (t));
2299 if (NULL != t->pong_h)
2301 LOG (GNUNET_ERROR_TYPE_INFO, " already queued\n");
2304 msg.header.size = htons (sizeof (msg));
2305 msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_KX_PONG);
2306 msg.iv = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX);
2307 msg.nonce = challenge;
2308 LOG (GNUNET_ERROR_TYPE_DEBUG, " sending %u\n", msg.nonce);
2309 t_encrypt (t, &msg.nonce, &msg.nonce,
2310 sizeof (msg.nonce), msg.iv, GNUNET_YES);
2311 LOG (GNUNET_ERROR_TYPE_DEBUG, " e sending %u\n", msg.nonce);
2313 t->pong_h = send_kx (t, &msg.header);
2318 * Initiate a rekey with the remote peer.
2320 * @param cls Closure (tunnel).
2321 * @param tc TaskContext.
2324 rekey_tunnel (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
2326 struct CadetTunnel *t = cls;
2328 t->rekey_task = NULL;
2330 LOG (GNUNET_ERROR_TYPE_INFO, "Re-key Tunnel %s\n", GCT_2s (t));
2331 if (NULL != tc && 0 != (GNUNET_SCHEDULER_REASON_SHUTDOWN & tc->reason))
2334 GNUNET_assert (NULL != t->kx_ctx);
2335 struct GNUNET_TIME_Relative duration;
2337 duration = GNUNET_TIME_absolute_get_duration (t->kx_ctx->rekey_start_time);
2338 LOG (GNUNET_ERROR_TYPE_DEBUG, " kx started %s ago\n",
2339 GNUNET_STRINGS_relative_time_to_string (duration, GNUNET_YES));
2341 // FIXME make duration of old keys configurable
2342 if (duration.rel_value_us >= GNUNET_TIME_UNIT_MINUTES.rel_value_us)
2344 LOG (GNUNET_ERROR_TYPE_DEBUG, " deleting old keys\n");
2345 memset (&t->kx_ctx->d_key_old, 0, sizeof (t->kx_ctx->d_key_old));
2346 memset (&t->kx_ctx->e_key_old, 0, sizeof (t->kx_ctx->e_key_old));
2353 case CADET_TUNNEL_KEY_UNINITIALIZED:
2354 GCT_change_estate (t, CADET_TUNNEL_KEY_SENT);
2357 case CADET_TUNNEL_KEY_SENT:
2360 case CADET_TUNNEL_KEY_OK:
2362 * - state should have changed during rekey_iterator
2363 * - task should have been canceled at pong_handle
2366 GCT_change_estate (t, CADET_TUNNEL_KEY_REKEY);
2369 case CADET_TUNNEL_KEY_PING:
2370 case CADET_TUNNEL_KEY_REKEY:
2374 LOG (GNUNET_ERROR_TYPE_DEBUG, "Unexpected state %u\n", t->estate);
2377 // FIXME exponential backoff
2378 struct GNUNET_TIME_Relative delay;
2380 delay = GNUNET_TIME_relative_divide (rekey_period, 16);
2381 delay = GNUNET_TIME_relative_min (delay, REKEY_WAIT);
2382 LOG (GNUNET_ERROR_TYPE_DEBUG, " next call in %s\n",
2383 GNUNET_STRINGS_relative_time_to_string (delay, GNUNET_YES));
2384 t->rekey_task = GNUNET_SCHEDULER_add_delayed (delay, &rekey_tunnel, t);
2389 * Our ephemeral key has changed, create new session key on all tunnels.
2391 * Each tunnel will start the Key Exchange with a random delay between
2392 * 0 and number_of_tunnels*100 milliseconds, so there are 10 key exchanges
2393 * per second, on average.
2395 * @param cls Closure (size of the hashmap).
2396 * @param key Current public key.
2397 * @param value Value in the hash map (tunnel).
2399 * @return #GNUNET_YES, so we should continue to iterate,
2402 rekey_iterator (void *cls,
2403 const struct GNUNET_PeerIdentity *key,
2406 struct CadetTunnel *t = value;
2407 struct GNUNET_TIME_Relative delay;
2408 long n = (long) cls;
2411 if (NULL != t->rekey_task)
2414 if (GNUNET_YES == GCT_is_loopback (t))
2417 if (CADET_OTR != t->enc_type)
2420 r = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK, (uint32_t) n * 100);
2421 delay = GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MILLISECONDS, r);
2422 t->rekey_task = GNUNET_SCHEDULER_add_delayed (delay, &rekey_tunnel, t);
2423 if (GNUNET_OK == create_kx_ctx (t))
2424 GCT_change_estate (t, CADET_TUNNEL_KEY_REKEY);
2436 * Create a new ephemeral key and key message, schedule next rekeying.
2438 * @param cls Closure (unused).
2439 * @param tc TaskContext.
2442 global_otr_rekey (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
2444 struct GNUNET_TIME_Absolute time;
2449 if (0 != (GNUNET_SCHEDULER_REASON_SHUTDOWN & tc->reason))
2452 GNUNET_free_non_null (otr_ephemeral_key);
2453 otr_ephemeral_key = GNUNET_CRYPTO_ecdhe_key_create ();
2455 time = GNUNET_TIME_absolute_get ();
2456 otr_kx_msg.creation_time = GNUNET_TIME_absolute_hton (time);
2457 time = GNUNET_TIME_absolute_add (time, rekey_period);
2458 time = GNUNET_TIME_absolute_add (time, GNUNET_TIME_UNIT_MINUTES);
2459 otr_kx_msg.expiration_time = GNUNET_TIME_absolute_hton (time);
2460 GNUNET_CRYPTO_ecdhe_key_get_public (otr_ephemeral_key, &otr_kx_msg.ephemeral_key);
2461 LOG (GNUNET_ERROR_TYPE_INFO, "GLOBAL OTR RE-KEY, NEW EPHM: %s\n",
2462 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &otr_kx_msg.ephemeral_key));
2464 GNUNET_assert (GNUNET_OK ==
2465 GNUNET_CRYPTO_eddsa_sign (id_key,
2466 &otr_kx_msg.purpose,
2467 &otr_kx_msg.signature));
2469 n = (long) GNUNET_CONTAINER_multipeermap_size (tunnels);
2470 GNUNET_CONTAINER_multipeermap_iterate (tunnels, &rekey_iterator, (void *) n);
2472 rekey_task = GNUNET_SCHEDULER_add_delayed (rekey_period,
2473 &global_otr_rekey, NULL);
2478 * Called only on shutdown, destroy every tunnel.
2480 * @param cls Closure (unused).
2481 * @param key Current public key.
2482 * @param value Value in the hash map (tunnel).
2484 * @return #GNUNET_YES, so we should continue to iterate,
2487 destroy_iterator (void *cls,
2488 const struct GNUNET_PeerIdentity *key,
2491 struct CadetTunnel *t = value;
2493 LOG (GNUNET_ERROR_TYPE_DEBUG, "GCT_shutdown destroying tunnel at %p\n", t);
2500 * Notify remote peer that we don't know a channel he is talking about,
2501 * probably CHANNEL_DESTROY was missed.
2503 * @param t Tunnel on which to notify.
2504 * @param gid ID of the channel.
2507 send_channel_destroy (struct CadetTunnel *t, unsigned int gid)
2509 struct GNUNET_CADET_ChannelManage msg;
2511 msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_CHANNEL_DESTROY);
2512 msg.header.size = htons (sizeof (msg));
2513 msg.chid = htonl (gid);
2515 LOG (GNUNET_ERROR_TYPE_DEBUG,
2516 "WARNING destroying unknown channel %u on tunnel %s\n",
2518 send_prebuilt_message (&msg.header, t, NULL, GNUNET_YES, NULL, NULL, NULL);
2523 * Demultiplex data per channel and call appropriate channel handler.
2525 * @param t Tunnel on which the data came.
2526 * @param msg Data message.
2527 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
2528 * #GNUNET_YES if message is FWD on the respective channel (loopback)
2529 * #GNUNET_NO if message is BCK on the respective channel (loopback)
2530 * #GNUNET_SYSERR if message on a one-ended channel (remote)
2533 handle_data (struct CadetTunnel *t,
2534 const struct GNUNET_CADET_Data *msg,
2537 struct CadetChannel *ch;
2543 size = ntohs (msg->header.size);
2545 sizeof (struct GNUNET_CADET_Data) +
2546 sizeof (struct GNUNET_MessageHeader))
2551 type = ntohs (msg[1].header.type);
2552 LOG (GNUNET_ERROR_TYPE_DEBUG, " payload of type %s\n", GC_m2s (type));
2553 sprintf (buf, "# received payload of type %hu", type);
2554 GNUNET_STATISTICS_update (stats, buf, 1, GNUNET_NO);
2558 ch = GCT_get_channel (t, ntohl (msg->chid));
2561 GNUNET_STATISTICS_update (stats, "# data on unknown channel",
2563 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel 0x%X unknown\n",
2565 send_channel_destroy (t, ntohl (msg->chid));
2569 GCCH_handle_data (ch, msg, fwd);
2574 * Demultiplex data ACKs per channel and update appropriate channel buffer info.
2576 * @param t Tunnel on which the DATA ACK came.
2577 * @param msg DATA ACK message.
2578 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
2579 * #GNUNET_YES if message is FWD on the respective channel (loopback)
2580 * #GNUNET_NO if message is BCK on the respective channel (loopback)
2581 * #GNUNET_SYSERR if message on a one-ended channel (remote)
2584 handle_data_ack (struct CadetTunnel *t,
2585 const struct GNUNET_CADET_DataACK *msg,
2588 struct CadetChannel *ch;
2592 size = ntohs (msg->header.size);
2593 if (size != sizeof (struct GNUNET_CADET_DataACK))
2600 ch = GCT_get_channel (t, ntohl (msg->chid));
2603 GNUNET_STATISTICS_update (stats, "# data ack on unknown channel",
2605 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel %u unknown\n",
2610 GCCH_handle_data_ack (ch, msg, fwd);
2615 * Handle channel create.
2617 * @param t Tunnel on which the data came.
2618 * @param msg Data message.
2621 handle_ch_create (struct CadetTunnel *t,
2622 const struct GNUNET_CADET_ChannelCreate *msg)
2624 struct CadetChannel *ch;
2628 size = ntohs (msg->header.size);
2629 if (size != sizeof (struct GNUNET_CADET_ChannelCreate))
2636 ch = GCT_get_channel (t, ntohl (msg->chid));
2637 if (NULL != ch && ! GCT_is_loopback (t))
2639 /* Probably a retransmission, safe to ignore */
2640 LOG (GNUNET_ERROR_TYPE_DEBUG, " already exists...\n");
2642 ch = GCCH_handle_create (t, msg);
2644 GCT_add_channel (t, ch);
2650 * Handle channel NACK: check correctness and call channel handler for NACKs.
2652 * @param t Tunnel on which the NACK came.
2653 * @param msg NACK message.
2656 handle_ch_nack (struct CadetTunnel *t,
2657 const struct GNUNET_CADET_ChannelManage *msg)
2659 struct CadetChannel *ch;
2663 size = ntohs (msg->header.size);
2664 if (size != sizeof (struct GNUNET_CADET_ChannelManage))
2671 ch = GCT_get_channel (t, ntohl (msg->chid));
2674 GNUNET_STATISTICS_update (stats, "# channel NACK on unknown channel",
2676 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel %u unknown\n",
2681 GCCH_handle_nack (ch);
2686 * Handle a CHANNEL ACK (SYNACK/ACK).
2688 * @param t Tunnel on which the CHANNEL ACK came.
2689 * @param msg CHANNEL ACK message.
2690 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
2691 * #GNUNET_YES if message is FWD on the respective channel (loopback)
2692 * #GNUNET_NO if message is BCK on the respective channel (loopback)
2693 * #GNUNET_SYSERR if message on a one-ended channel (remote)
2696 handle_ch_ack (struct CadetTunnel *t,
2697 const struct GNUNET_CADET_ChannelManage *msg,
2700 struct CadetChannel *ch;
2704 size = ntohs (msg->header.size);
2705 if (size != sizeof (struct GNUNET_CADET_ChannelManage))
2712 ch = GCT_get_channel (t, ntohl (msg->chid));
2715 GNUNET_STATISTICS_update (stats, "# channel ack on unknown channel",
2717 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel %u unknown\n",
2722 GCCH_handle_ack (ch, msg, fwd);
2727 * Handle a channel destruction message.
2729 * @param t Tunnel on which the message came.
2730 * @param msg Channel destroy message.
2731 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
2732 * #GNUNET_YES if message is FWD on the respective channel (loopback)
2733 * #GNUNET_NO if message is BCK on the respective channel (loopback)
2734 * #GNUNET_SYSERR if message on a one-ended channel (remote)
2737 handle_ch_destroy (struct CadetTunnel *t,
2738 const struct GNUNET_CADET_ChannelManage *msg,
2741 struct CadetChannel *ch;
2745 size = ntohs (msg->header.size);
2746 if (size != sizeof (struct GNUNET_CADET_ChannelManage))
2753 ch = GCT_get_channel (t, ntohl (msg->chid));
2756 /* Probably a retransmission, safe to ignore */
2760 GCCH_handle_destroy (ch, msg, fwd);
2765 * Free Axolotl data.
2770 destroy_ax (struct CadetTunnel *t)
2775 GNUNET_free_non_null (t->ax->DHRs);
2776 GNUNET_free_non_null (t->ax->kx_0);
2777 while (NULL != t->ax->skipped_head)
2778 delete_skipped_key (t, t->ax->skipped_head);
2779 GNUNET_assert (0 == t->ax->skipped);
2781 GNUNET_free (t->ax);
2784 if (NULL != t->rekey_task)
2786 GNUNET_SCHEDULER_cancel (t->rekey_task);
2787 t->rekey_task = NULL;
2789 if (NULL != t->ephm_h)
2791 GCC_cancel (t->ephm_h);
2798 * The peer's ephemeral key has changed: update the symmetrical keys.
2800 * @param t Tunnel this message came on.
2801 * @param msg Key eXchange message.
2804 handle_ephemeral (struct CadetTunnel *t,
2805 const struct GNUNET_CADET_KX_Ephemeral *msg)
2807 LOG (GNUNET_ERROR_TYPE_INFO, "<=== EPHM for %s\n", GCT_2s (t));
2809 /* Some old versions are still around, don't log as error. */
2810 if (GNUNET_OK != check_ephemeral (t, msg))
2813 /* If we get a proper OTR-style ephemeral, fallback to old crypto. */
2817 t->enc_type = CADET_OTR;
2818 if (NULL != t->rekey_task)
2819 GNUNET_SCHEDULER_cancel (t->rekey_task);
2820 if (GNUNET_OK != create_kx_ctx (t))
2826 rekey_tunnel (t, NULL);
2827 GNUNET_STATISTICS_update (stats, "# otr-downgrades", -1, GNUNET_NO);
2831 * If the key is different from what we know, derive the new E/D keys.
2832 * Else destroy the rekey ctx (duplicate EPHM after successful KX).
2834 if (0 != memcmp (&t->peers_ephemeral_key, &msg->ephemeral_key,
2835 sizeof (msg->ephemeral_key)))
2837 #if DUMP_KEYS_TO_STDERR
2838 LOG (GNUNET_ERROR_TYPE_INFO, "OLD: %s\n",
2839 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &t->peers_ephemeral_key));
2840 LOG (GNUNET_ERROR_TYPE_INFO, "NEW: %s\n",
2841 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &msg->ephemeral_key));
2843 t->peers_ephemeral_key = msg->ephemeral_key;
2845 if (GNUNET_OK != create_kx_ctx (t))
2852 if (CADET_TUNNEL_KEY_OK == t->estate)
2854 GCT_change_estate (t, CADET_TUNNEL_KEY_REKEY);
2856 if (NULL != t->rekey_task)
2857 GNUNET_SCHEDULER_cancel (t->rekey_task);
2858 t->rekey_task = GNUNET_SCHEDULER_add_now (rekey_tunnel, t);
2860 if (CADET_TUNNEL_KEY_SENT == t->estate)
2862 LOG (GNUNET_ERROR_TYPE_DEBUG, " our key was sent, sending challenge\n");
2864 GCT_change_estate (t, CADET_TUNNEL_KEY_PING);
2867 if (CADET_TUNNEL_KEY_UNINITIALIZED != ntohl(msg->sender_status))
2871 LOG (GNUNET_ERROR_TYPE_DEBUG, " recv nonce e %u\n", msg->nonce);
2872 t_decrypt (t, &nonce, &msg->nonce, ping_encryption_size (), msg->iv);
2873 LOG (GNUNET_ERROR_TYPE_DEBUG, " recv nonce c %u\n", nonce);
2874 send_pong (t, nonce);
2880 * Peer has answer to our challenge.
2881 * If answer is successful, consider the key exchange finished and clean
2882 * up all related state.
2884 * @param t Tunnel this message came on.
2885 * @param msg Key eXchange Pong message.
2888 handle_pong (struct CadetTunnel *t,
2889 const struct GNUNET_CADET_KX_Pong *msg)
2893 LOG (GNUNET_ERROR_TYPE_INFO, "<=== PONG for %s\n", GCT_2s (t));
2894 if (NULL == t->rekey_task)
2896 GNUNET_STATISTICS_update (stats, "# duplicate PONG messages", 1, GNUNET_NO);
2899 if (NULL == t->kx_ctx)
2901 GNUNET_STATISTICS_update (stats, "# stray PONG messages", 1, GNUNET_NO);
2905 t_decrypt (t, &challenge, &msg->nonce, sizeof (uint32_t), msg->iv);
2906 if (challenge != t->kx_ctx->challenge)
2908 LOG (GNUNET_ERROR_TYPE_WARNING, "Wrong PONG challenge on %s\n", GCT_2s (t));
2909 LOG (GNUNET_ERROR_TYPE_DEBUG, "PONG: %u (e: %u). Expected: %u.\n",
2910 challenge, msg->nonce, t->kx_ctx->challenge);
2914 GNUNET_SCHEDULER_cancel (t->rekey_task);
2915 t->rekey_task = NULL;
2917 /* Don't free the old keys right away, but after a delay.
2918 * Rationale: the KX could have happened over a very fast connection,
2919 * with payload traffic still signed with the old key stuck in a slower
2921 * Don't keep the keys longer than 1/4 the rekey period, and no longer than
2925 GCT_change_estate (t, CADET_TUNNEL_KEY_OK);
2930 * Handle Axolotl handshake.
2932 * @param t Tunnel this message came on.
2933 * @param msg Key eXchange Pong message.
2936 handle_kx_ax (struct CadetTunnel *t, const struct GNUNET_CADET_AX_KX *msg)
2938 struct CadetTunnelAxolotl *ax;
2939 struct GNUNET_HashCode key_material[3];
2940 struct GNUNET_CRYPTO_SymmetricSessionKey keys[5];
2941 const char salt[] = "CADET Axolotl salt";
2942 const struct GNUNET_PeerIdentity *pid;
2945 LOG (GNUNET_ERROR_TYPE_INFO, "<=== AX_KX on %s\n", GCT_2s (t));
2949 /* Something is wrong if ax is NULL. Whose fault it is? */
2950 GNUNET_break_op (CADET_OTR == t->enc_type);
2951 GNUNET_break (CADET_Axolotl == t->enc_type);
2956 pid = GCT_get_destination (t);
2957 if (0 > GNUNET_CRYPTO_cmp_peer_identity (&my_full_id, pid))
2958 am_I_alice = GNUNET_YES;
2959 else if (0 < GNUNET_CRYPTO_cmp_peer_identity (&my_full_id, pid))
2960 am_I_alice = GNUNET_NO;
2963 GNUNET_break_op (0);
2967 if (0 != (GNUNET_CADET_AX_KX_FLAG_FORCE_REPLY & ntohl (msg->flags)))
2969 if (NULL != t->rekey_task)
2971 GNUNET_SCHEDULER_cancel (t->rekey_task);
2972 t->rekey_task = NULL;
2974 GCT_send_ax_kx (t, GNUNET_NO);
2977 if (0 == memcmp (&ax->DHRr, &msg->ratchet_key, sizeof(msg->ratchet_key)))
2979 LOG (GNUNET_ERROR_TYPE_INFO, " known ratchet key, exit\n");
2983 LOG (GNUNET_ERROR_TYPE_INFO, " is Alice? %s\n", am_I_alice ? "YES" : "NO");
2985 ax->DHRr = msg->ratchet_key;
2988 if (GNUNET_YES == am_I_alice)
2990 GNUNET_CRYPTO_eddsa_ecdh (id_key, /* A */
2991 &msg->ephemeral_key, /* B0 */
2996 GNUNET_CRYPTO_ecdh_eddsa (ax->kx_0, /* B0 */
2997 &pid->public_key, /* A */
3002 if (GNUNET_YES == am_I_alice)
3004 GNUNET_CRYPTO_ecdh_eddsa (ax->kx_0, /* A0 */
3005 &pid->public_key, /* B */
3010 GNUNET_CRYPTO_eddsa_ecdh (id_key, /* A */
3011 &msg->ephemeral_key, /* B0 */
3018 /* (This is the triple-DH, we could probably safely skip this,
3019 as A0/B0 are already in the key material.) */
3020 GNUNET_CRYPTO_ecc_ecdh (ax->kx_0, /* A0 or B0 */
3021 &msg->ephemeral_key, /* B0 or A0 */
3024 #if DUMP_KEYS_TO_STDERR
3027 for (i = 0; i < 3; i++)
3028 LOG (GNUNET_ERROR_TYPE_INFO, "km[%u]: %s\n",
3029 i, GNUNET_h2s (&key_material[i]));
3034 GNUNET_CRYPTO_kdf (keys, sizeof (keys),
3035 salt, sizeof (salt),
3036 &key_material, sizeof (key_material), NULL);
3038 if (0 == memcmp (&ax->RK, &keys[0], sizeof(ax->RK)))
3040 LOG (GNUNET_ERROR_TYPE_INFO, " known handshake key, exit\n");
3044 if (GNUNET_YES == am_I_alice)
3050 ax->ratchet_flag = GNUNET_YES;
3058 ax->ratchet_flag = GNUNET_NO;
3059 ax->ratchet_allowed = GNUNET_NO;
3060 ax->ratchet_counter = 0;
3061 ax->ratchet_expiration =
3062 GNUNET_TIME_absolute_add (GNUNET_TIME_absolute_get(), ratchet_time);
3067 GCT_change_estate (t, CADET_TUNNEL_KEY_PING);
3068 send_queued_data (t);
3073 * Demultiplex by message type and call appropriate handler for a message
3074 * towards a channel of a local tunnel.
3076 * @param t Tunnel this message came on.
3077 * @param msgh Message header.
3078 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
3079 * #GNUNET_YES if message is FWD on the respective channel (loopback)
3080 * #GNUNET_NO if message is BCK on the respective channel (loopback)
3081 * #GNUNET_SYSERR if message on a one-ended channel (remote)
3084 handle_decrypted (struct CadetTunnel *t,
3085 const struct GNUNET_MessageHeader *msgh,
3091 type = ntohs (msgh->type);
3092 LOG (GNUNET_ERROR_TYPE_INFO, "<=== %s on %s\n", GC_m2s (type), GCT_2s (t));
3093 sprintf (buf, "# received encrypted of type %hu (%s)", type, GC_m2s (type));
3094 GNUNET_STATISTICS_update (stats, buf, 1, GNUNET_NO);
3098 case GNUNET_MESSAGE_TYPE_CADET_KEEPALIVE:
3099 /* Do nothing, connection aleady got updated. */
3100 GNUNET_STATISTICS_update (stats, "# keepalives received", 1, GNUNET_NO);
3103 case GNUNET_MESSAGE_TYPE_CADET_DATA:
3104 /* Don't send hop ACK, wait for client to ACK */
3105 handle_data (t, (struct GNUNET_CADET_Data *) msgh, fwd);
3108 case GNUNET_MESSAGE_TYPE_CADET_DATA_ACK:
3109 handle_data_ack (t, (struct GNUNET_CADET_DataACK *) msgh, fwd);
3112 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_CREATE:
3113 handle_ch_create (t, (struct GNUNET_CADET_ChannelCreate *) msgh);
3116 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_NACK:
3117 handle_ch_nack (t, (struct GNUNET_CADET_ChannelManage *) msgh);
3120 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_ACK:
3121 handle_ch_ack (t, (struct GNUNET_CADET_ChannelManage *) msgh, fwd);
3124 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_DESTROY:
3125 handle_ch_destroy (t, (struct GNUNET_CADET_ChannelManage *) msgh, fwd);
3129 GNUNET_break_op (0);
3130 LOG (GNUNET_ERROR_TYPE_WARNING,
3131 "end-to-end message not known (%u)\n",
3132 ntohs (msgh->type));
3133 GCT_debug (t, GNUNET_ERROR_TYPE_WARNING);
3138 /******************************************************************************/
3139 /******************************** API ***********************************/
3140 /******************************************************************************/
3142 * Decrypt old format and demultiplex by message type. Call appropriate handler
3143 * for a message towards a channel of a local tunnel.
3145 * @param t Tunnel this message came on.
3146 * @param msg Message header.
3149 GCT_handle_encrypted (struct CadetTunnel *t,
3150 const struct GNUNET_MessageHeader *msg)
3152 uint16_t size = ntohs (msg->size);
3156 const struct GNUNET_MessageHeader *msgh;
3159 type = ntohs (msg->type);
3162 case GNUNET_MESSAGE_TYPE_CADET_ENCRYPTED:
3164 const struct GNUNET_CADET_Encrypted *emsg;
3165 size_t payload_size;
3167 GNUNET_STATISTICS_update (stats, "# received OTR", 1, GNUNET_NO);
3168 emsg = (const struct GNUNET_CADET_Encrypted *) msg;
3169 payload_size = size - sizeof (struct GNUNET_CADET_Encrypted);
3170 decrypted_size = t_decrypt_and_validate (t, cbuf, &emsg[1], payload_size,
3171 emsg->iv, &emsg->hmac);
3174 case GNUNET_MESSAGE_TYPE_CADET_AX:
3176 const struct GNUNET_CADET_AX *emsg;
3178 GNUNET_STATISTICS_update (stats, "# received Axolotl", 1, GNUNET_NO);
3179 emsg = (const struct GNUNET_CADET_AX *) msg;
3180 decrypted_size = t_ax_decrypt_and_validate (t, cbuf, emsg, size);
3184 GNUNET_break_op (0);
3188 if (-1 == decrypted_size)
3190 GNUNET_break_op (0);
3191 GNUNET_STATISTICS_update (stats, "# unable to decrypt", 1, GNUNET_NO);
3192 LOG (GNUNET_ERROR_TYPE_WARNING, "Wrong crypto on tunnel %s\n", GCT_2s (t));
3193 GCT_debug (t, GNUNET_ERROR_TYPE_WARNING);
3196 GCT_change_estate (t, CADET_TUNNEL_KEY_OK);
3198 /* FIXME: this is bad, as the structs returned from
3199 this loop may be unaligned, see util's MST for
3200 how to do this right. */
3202 while (off + sizeof (struct GNUNET_MessageHeader) <= decrypted_size)
3206 msgh = (const struct GNUNET_MessageHeader *) &cbuf[off];
3207 msize = ntohs (msgh->size);
3208 if (msize < sizeof (struct GNUNET_MessageHeader))
3210 GNUNET_break_op (0);
3213 if (off + msize < decrypted_size)
3215 GNUNET_break_op (0);
3218 handle_decrypted (t, msgh, GNUNET_SYSERR);
3225 * Demultiplex an encapsulated KX message by message type.
3227 * @param t Tunnel on which the message came.
3228 * @param message Payload of KX message.
3231 GCT_handle_kx (struct CadetTunnel *t,
3232 const struct GNUNET_MessageHeader *message)
3237 type = ntohs (message->type);
3238 LOG (GNUNET_ERROR_TYPE_DEBUG, "kx message received: %s\n", GC_m2s (type));
3239 sprintf (buf, "# received KX of type %hu (%s)", type, GC_m2s (type));
3240 GNUNET_STATISTICS_update (stats, buf, 1, GNUNET_NO);
3243 case GNUNET_MESSAGE_TYPE_CADET_KX_EPHEMERAL:
3244 handle_ephemeral (t, (const struct GNUNET_CADET_KX_Ephemeral *) message);
3247 case GNUNET_MESSAGE_TYPE_CADET_KX_PONG:
3248 handle_pong (t, (const struct GNUNET_CADET_KX_Pong *) message);
3251 case GNUNET_MESSAGE_TYPE_CADET_AX_KX:
3252 handle_kx_ax (t, (const struct GNUNET_CADET_AX_KX *) message);
3256 GNUNET_break_op (0);
3257 LOG (GNUNET_ERROR_TYPE_WARNING, "kx message %s unknown\n", GC_m2s (type));
3262 * Initialize the tunnel subsystem.
3264 * @param c Configuration handle.
3265 * @param key ECC private key, to derive all other keys and do crypto.
3268 GCT_init (const struct GNUNET_CONFIGURATION_Handle *c,
3269 const struct GNUNET_CRYPTO_EddsaPrivateKey *key)
3271 int expected_overhead;
3273 LOG (GNUNET_ERROR_TYPE_DEBUG, "init\n");
3275 expected_overhead = 0;
3276 expected_overhead += sizeof (struct GNUNET_CADET_Encrypted);
3277 expected_overhead += sizeof (struct GNUNET_CADET_Data);
3278 expected_overhead += sizeof (struct GNUNET_CADET_ACK);
3279 GNUNET_assert (GNUNET_CONSTANTS_CADET_P2P_OVERHEAD == expected_overhead);
3282 GNUNET_CONFIGURATION_get_value_number (c, "CADET", "DEFAULT_TTL",
3285 GNUNET_log_config_invalid (GNUNET_ERROR_TYPE_DEBUG,
3286 "CADET", "DEFAULT_TTL", "USING DEFAULT");
3290 GNUNET_CONFIGURATION_get_value_time (c, "CADET", "REKEY_PERIOD",
3293 rekey_period = GNUNET_TIME_UNIT_DAYS;
3296 GNUNET_CONFIGURATION_get_value_number (c, "CADET", "RATCHET_MESSAGES",
3299 GNUNET_log_config_invalid (GNUNET_ERROR_TYPE_WARNING,
3300 "CADET", "RATCHET_MESSAGES", "USING DEFAULT");
3301 ratchet_messages = 64;
3304 GNUNET_CONFIGURATION_get_value_time (c, "CADET", "RATCHET_TIME",
3307 GNUNET_log_config_invalid (GNUNET_ERROR_TYPE_WARNING,
3308 "CADET", "RATCHET_TIME", "USING DEFAULT");
3309 ratchet_time = GNUNET_TIME_UNIT_HOURS;
3315 otr_kx_msg.header.size = htons (sizeof (otr_kx_msg));
3316 otr_kx_msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_KX_EPHEMERAL);
3317 otr_kx_msg.purpose.purpose = htonl (GNUNET_SIGNATURE_PURPOSE_CADET_KX);
3318 otr_kx_msg.purpose.size = htonl (ephemeral_purpose_size ());
3319 otr_kx_msg.origin_identity = my_full_id;
3320 rekey_task = GNUNET_SCHEDULER_add_now (&global_otr_rekey, NULL);
3321 tunnels = GNUNET_CONTAINER_multipeermap_create (128, GNUNET_YES);
3326 * Shut down the tunnel subsystem.
3331 LOG (GNUNET_ERROR_TYPE_DEBUG, "Shutting down tunnels\n");
3332 if (NULL != rekey_task)
3334 GNUNET_SCHEDULER_cancel (rekey_task);
3337 GNUNET_CONTAINER_multipeermap_iterate (tunnels, &destroy_iterator, NULL);
3338 GNUNET_CONTAINER_multipeermap_destroy (tunnels);
3345 * @param destination Peer this tunnel is towards.
3347 struct CadetTunnel *
3348 GCT_new (struct CadetPeer *destination)
3350 struct CadetTunnel *t;
3352 t = GNUNET_new (struct CadetTunnel);
3354 t->peer = destination;
3357 GNUNET_CONTAINER_multipeermap_put (tunnels, GCP_get_id (destination), t,
3358 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_FAST))
3364 t->ax = GNUNET_new (struct CadetTunnelAxolotl);
3366 t->ax->kx_0 = GNUNET_CRYPTO_ecdhe_key_create ();
3372 * Change the tunnel's connection state.
3374 * @param t Tunnel whose connection state to change.
3375 * @param cstate New connection state.
3378 GCT_change_cstate (struct CadetTunnel* t, enum CadetTunnelCState cstate)
3382 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel %s cstate %s => %s\n",
3383 GCP_2s (t->peer), cstate2s (t->cstate), cstate2s (cstate));
3384 if (myid != GCP_get_short_id (t->peer) &&
3385 CADET_TUNNEL_READY != t->cstate &&
3386 CADET_TUNNEL_READY == cstate)
3389 if (CADET_TUNNEL_KEY_OK == t->estate)
3391 LOG (GNUNET_ERROR_TYPE_DEBUG, " cstate triggered send queued data\n");
3392 send_queued_data (t);
3394 else if (CADET_TUNNEL_KEY_UNINITIALIZED == t->estate)
3396 LOG (GNUNET_ERROR_TYPE_DEBUG, " cstate triggered kx\n");
3397 GCT_send_ax_kx (t, GNUNET_NO);
3401 LOG (GNUNET_ERROR_TYPE_DEBUG, "estate %s\n", estate2s (t->estate));
3406 if (CADET_TUNNEL_READY == cstate
3407 && CONNECTIONS_PER_TUNNEL <= GCT_count_connections (t))
3409 LOG (GNUNET_ERROR_TYPE_DEBUG, " cstate triggered stop dht\n");
3410 GCP_stop_search (t->peer);
3416 * Change the tunnel encryption state.
3418 * If the encryption state changes to OK, stop the rekey task.
3420 * @param t Tunnel whose encryption state to change, or NULL.
3421 * @param state New encryption state.
3424 GCT_change_estate (struct CadetTunnel* t, enum CadetTunnelEState state)
3426 enum CadetTunnelEState old;
3433 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel %s estate was %s\n",
3434 GCP_2s (t->peer), estate2s (old));
3435 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel %s estate is now %s\n",
3436 GCP_2s (t->peer), estate2s (t->estate));
3438 if (CADET_TUNNEL_KEY_OK != old && CADET_TUNNEL_KEY_OK == t->estate)
3440 if (NULL != t->rekey_task)
3442 GNUNET_SCHEDULER_cancel (t->rekey_task);
3443 t->rekey_task = NULL;
3445 /* Send queued data if tunnel is not loopback */
3446 if (myid != GCP_get_short_id (t->peer))
3447 send_queued_data (t);
3453 * @brief Check if tunnel has too many connections, and remove one if necessary.
3455 * Currently this means the newest connection, unless it is a direct one.
3456 * Implemented as a task to avoid freeing a connection that is in the middle
3457 * of being created/processed.
3459 * @param cls Closure (Tunnel to check).
3460 * @param tc Task context.
3463 trim_connections (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
3465 struct CadetTunnel *t = cls;
3467 t->trim_connections_task = NULL;
3469 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
3472 if (GCT_count_connections (t) > 2 * CONNECTIONS_PER_TUNNEL)
3474 struct CadetTConnection *iter;
3475 struct CadetTConnection *c;
3477 for (c = iter = t->connection_head; NULL != iter; iter = iter->next)
3479 if ((iter->created.abs_value_us > c->created.abs_value_us)
3480 && GNUNET_NO == GCC_is_direct (iter->c))
3487 LOG (GNUNET_ERROR_TYPE_DEBUG, "Too many connections on tunnel %s\n",
3489 LOG (GNUNET_ERROR_TYPE_DEBUG, "Destroying connection %s\n",
3502 * Add a connection to a tunnel.
3505 * @param c Connection.
3508 GCT_add_connection (struct CadetTunnel *t, struct CadetConnection *c)
3510 struct CadetTConnection *aux;
3512 GNUNET_assert (NULL != c);
3514 LOG (GNUNET_ERROR_TYPE_DEBUG, "add connection %s\n", GCC_2s (c));
3515 LOG (GNUNET_ERROR_TYPE_DEBUG, " to tunnel %s\n", GCT_2s (t));
3516 for (aux = t->connection_head; aux != NULL; aux = aux->next)
3520 aux = GNUNET_new (struct CadetTConnection);
3522 aux->created = GNUNET_TIME_absolute_get ();
3524 GNUNET_CONTAINER_DLL_insert (t->connection_head, t->connection_tail, aux);
3526 if (CADET_TUNNEL_SEARCHING == t->cstate)
3527 GCT_change_cstate (t, CADET_TUNNEL_WAITING);
3529 if (NULL != t->trim_connections_task)
3530 t->trim_connections_task = GNUNET_SCHEDULER_add_now (&trim_connections, t);
3535 * Remove a connection from a tunnel.
3538 * @param c Connection.
3541 GCT_remove_connection (struct CadetTunnel *t,
3542 struct CadetConnection *c)
3544 struct CadetTConnection *aux;
3545 struct CadetTConnection *next;
3548 LOG (GNUNET_ERROR_TYPE_DEBUG, "Removing connection %s from tunnel %s\n",
3549 GCC_2s (c), GCT_2s (t));
3550 for (aux = t->connection_head; aux != NULL; aux = next)
3555 GNUNET_CONTAINER_DLL_remove (t->connection_head, t->connection_tail, aux);
3560 conns = GCT_count_connections (t);
3562 && NULL == t->destroy_task
3563 && CADET_TUNNEL_SHUTDOWN != t->cstate
3564 && GNUNET_NO == shutting_down)
3566 if (0 == GCT_count_any_connections (t))
3567 GCT_change_cstate (t, CADET_TUNNEL_SEARCHING);
3569 GCT_change_cstate (t, CADET_TUNNEL_WAITING);
3572 /* Start new connections if needed */
3573 if (CONNECTIONS_PER_TUNNEL > conns
3574 && CADET_TUNNEL_SHUTDOWN != t->cstate
3575 && GNUNET_NO == shutting_down)
3577 LOG (GNUNET_ERROR_TYPE_DEBUG, " too few connections, getting new ones\n");
3578 GCP_connect (t->peer); /* Will change cstate to WAITING when possible */
3582 /* If not marked as ready, no change is needed */
3583 if (CADET_TUNNEL_READY != t->cstate)
3586 /* Check if any connection is ready to maintain cstate */
3587 for (aux = t->connection_head; aux != NULL; aux = aux->next)
3588 if (CADET_CONNECTION_READY == GCC_get_state (aux->c))
3594 * Add a channel to a tunnel.
3597 * @param ch Channel.
3600 GCT_add_channel (struct CadetTunnel *t, struct CadetChannel *ch)
3602 struct CadetTChannel *aux;
3604 GNUNET_assert (NULL != ch);
3606 LOG (GNUNET_ERROR_TYPE_DEBUG, "Adding channel %p to tunnel %p\n", ch, t);
3608 for (aux = t->channel_head; aux != NULL; aux = aux->next)
3610 LOG (GNUNET_ERROR_TYPE_DEBUG, " already there %p\n", aux->ch);
3615 aux = GNUNET_new (struct CadetTChannel);
3617 LOG (GNUNET_ERROR_TYPE_DEBUG, " adding %p to %p\n", aux, t->channel_head);
3618 GNUNET_CONTAINER_DLL_insert_tail (t->channel_head, t->channel_tail, aux);
3620 if (NULL != t->destroy_task)
3622 GNUNET_SCHEDULER_cancel (t->destroy_task);
3623 t->destroy_task = NULL;
3624 LOG (GNUNET_ERROR_TYPE_DEBUG, " undo destroy!\n");
3630 * Remove a channel from a tunnel.
3633 * @param ch Channel.
3636 GCT_remove_channel (struct CadetTunnel *t, struct CadetChannel *ch)
3638 struct CadetTChannel *aux;
3640 LOG (GNUNET_ERROR_TYPE_DEBUG, "Removing channel %p from tunnel %p\n", ch, t);
3641 for (aux = t->channel_head; aux != NULL; aux = aux->next)
3645 LOG (GNUNET_ERROR_TYPE_DEBUG, " found! %s\n", GCCH_2s (ch));
3646 GNUNET_CONTAINER_DLL_remove (t->channel_head, t->channel_tail, aux);
3655 * Search for a channel by global ID.
3657 * @param t Tunnel containing the channel.
3658 * @param chid Public channel number.
3660 * @return channel handler, NULL if doesn't exist
3662 struct CadetChannel *
3663 GCT_get_channel (struct CadetTunnel *t, CADET_ChannelNumber chid)
3665 struct CadetTChannel *iter;
3670 for (iter = t->channel_head; NULL != iter; iter = iter->next)
3672 if (GCCH_get_id (iter->ch) == chid)
3676 return NULL == iter ? NULL : iter->ch;
3681 * @brief Destroy a tunnel and free all resources.
3683 * Should only be called a while after the tunnel has been marked as destroyed,
3684 * in case there is a new channel added to the same peer shortly after marking
3685 * the tunnel. This way we avoid a new public key handshake.
3687 * @param cls Closure (tunnel to destroy).
3688 * @param tc Task context.
3691 delayed_destroy (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
3693 struct CadetTunnel *t = cls;
3694 struct CadetTConnection *iter;
3696 LOG (GNUNET_ERROR_TYPE_DEBUG, "delayed destroying tunnel %p\n", t);
3697 if (0 != (GNUNET_SCHEDULER_REASON_SHUTDOWN & tc->reason))
3699 LOG (GNUNET_ERROR_TYPE_WARNING,
3700 "Not destroying tunnel, due to shutdown. "
3701 "Tunnel at %p should have been freed by GCT_shutdown\n", t);
3704 t->destroy_task = NULL;
3705 t->cstate = CADET_TUNNEL_SHUTDOWN;
3707 for (iter = t->connection_head; NULL != iter; iter = iter->next)
3709 GCC_send_destroy (iter->c);
3716 * Tunnel is empty: destroy it.
3718 * Notifies all connections about the destruction.
3720 * @param t Tunnel to destroy.
3723 GCT_destroy_empty (struct CadetTunnel *t)
3725 if (GNUNET_YES == shutting_down)
3726 return; /* Will be destroyed immediately anyway */
3728 if (NULL != t->destroy_task)
3730 LOG (GNUNET_ERROR_TYPE_WARNING,
3731 "Tunnel %s is already scheduled for destruction. Tunnel debug dump:\n",
3733 GCT_debug (t, GNUNET_ERROR_TYPE_WARNING);
3735 /* should never happen, tunnel can only become empty once, and the
3736 * task identifier should be NO_TASK (cleaned when the tunnel was created
3737 * or became un-empty)
3742 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel %s empty: scheduling destruction\n",
3745 // FIXME make delay a config option
3746 t->destroy_task = GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_MINUTES,
3747 &delayed_destroy, t);
3748 LOG (GNUNET_ERROR_TYPE_DEBUG, "Scheduled destroy of %p as %p\n",
3749 t, t->destroy_task);
3754 * Destroy tunnel if empty (no more channels).
3756 * @param t Tunnel to destroy if empty.
3759 GCT_destroy_if_empty (struct CadetTunnel *t)
3761 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel %s destroy if empty\n", GCT_2s (t));
3762 if (0 < GCT_count_channels (t))
3765 GCT_destroy_empty (t);
3770 * Destroy the tunnel.
3772 * This function does not generate any warning traffic to clients or peers.
3775 * Cancel messages belonging to this tunnel queued to neighbors.
3776 * Free any allocated resources linked to the tunnel.
3778 * @param t The tunnel to destroy.
3781 GCT_destroy (struct CadetTunnel *t)
3783 struct CadetTConnection *iter_c;
3784 struct CadetTConnection *next_c;
3785 struct CadetTChannel *iter_ch;
3786 struct CadetTChannel *next_ch;
3787 unsigned int keepalives_queued;
3792 LOG (GNUNET_ERROR_TYPE_DEBUG, "destroying tunnel %s\n", GCP_2s (t->peer));
3794 GNUNET_break (GNUNET_YES ==
3795 GNUNET_CONTAINER_multipeermap_remove (tunnels,
3796 GCP_get_id (t->peer), t));
3798 for (iter_c = t->connection_head; NULL != iter_c; iter_c = next_c)
3800 next_c = iter_c->next;
3801 GCC_destroy (iter_c->c);
3803 for (iter_ch = t->channel_head; NULL != iter_ch; iter_ch = next_ch)
3805 next_ch = iter_ch->next;
3806 GCCH_destroy (iter_ch->ch);
3807 /* Should only happen on shutdown, but it's ok. */
3809 keepalives_queued = 0;
3810 while (NULL != t->tq_head)
3812 /* Should have been cleaned by destuction of channel. */
3813 struct GNUNET_MessageHeader *mh;
3816 mh = (struct GNUNET_MessageHeader *) &t->tq_head[1];
3817 type = ntohs (mh->type);
3818 if (0 == keepalives_queued && GNUNET_MESSAGE_TYPE_CADET_KEEPALIVE == type)
3820 keepalives_queued = 1;
3821 LOG (GNUNET_ERROR_TYPE_DEBUG,
3822 "one keepalive left behind on tunnel shutdown\n");
3824 else if (GNUNET_MESSAGE_TYPE_CADET_CHANNEL_DESTROY == type)
3826 LOG (GNUNET_ERROR_TYPE_WARNING,
3827 "tunnel destroyed before a CHANNEL_DESTROY was sent to peer\n");
3832 LOG (GNUNET_ERROR_TYPE_ERROR,
3833 "message left behind on tunnel shutdown: %s\n",
3836 unqueue_data (t->tq_head);
3840 if (NULL != t->destroy_task)
3842 LOG (GNUNET_ERROR_TYPE_DEBUG, "cancelling dest: %p\n", t->destroy_task);
3843 GNUNET_SCHEDULER_cancel (t->destroy_task);
3844 t->destroy_task = NULL;
3847 if (NULL != t->trim_connections_task)
3849 LOG (GNUNET_ERROR_TYPE_DEBUG, "cancelling trim: %p\n",
3850 t->trim_connections_task);
3851 GNUNET_SCHEDULER_cancel (t->trim_connections_task);
3852 t->trim_connections_task = NULL;
3855 GNUNET_STATISTICS_update (stats, "# tunnels", -1, GNUNET_NO);
3856 GCP_set_tunnel (t->peer, NULL);
3858 if (NULL != t->rekey_task)
3860 GNUNET_SCHEDULER_cancel (t->rekey_task);
3861 t->rekey_task = NULL;
3863 if (NULL != t->kx_ctx)
3865 if (NULL != t->kx_ctx->finish_task)
3866 GNUNET_SCHEDULER_cancel (t->kx_ctx->finish_task);
3867 GNUNET_free (t->kx_ctx);
3878 * @brief Use the given path for the tunnel.
3879 * Update the next and prev hops (and RCs).
3880 * (Re)start the path refresh in case the tunnel is locally owned.
3882 * @param t Tunnel to update.
3883 * @param p Path to use.
3885 * @return Connection created.
3887 struct CadetConnection *
3888 GCT_use_path (struct CadetTunnel *t, struct CadetPeerPath *path)
3890 struct CadetConnection *c;
3891 struct GNUNET_CADET_Hash cid;
3892 unsigned int own_pos;
3894 if (NULL == t || NULL == path)
3900 if (CADET_TUNNEL_SHUTDOWN == t->cstate)
3906 for (own_pos = 0; own_pos < path->length; own_pos++)
3908 if (path->peers[own_pos] == myid)
3911 if (own_pos >= path->length)
3913 GNUNET_break_op (0);
3917 GNUNET_CRYPTO_random_block (GNUNET_CRYPTO_QUALITY_NONCE, &cid, sizeof (cid));
3918 c = GCC_new (&cid, t, path, own_pos);
3921 /* Path was flawed */
3924 GCT_add_connection (t, c);
3930 * Count all created connections of a tunnel. Not necessarily ready connections!
3932 * @param t Tunnel on which to count.
3934 * @return Number of connections created, either being established or ready.
3937 GCT_count_any_connections (struct CadetTunnel *t)
3939 struct CadetTConnection *iter;
3945 for (count = 0, iter = t->connection_head; NULL != iter; iter = iter->next)
3953 * Count established (ready) connections of a tunnel.
3955 * @param t Tunnel on which to count.
3957 * @return Number of connections.
3960 GCT_count_connections (struct CadetTunnel *t)
3962 struct CadetTConnection *iter;
3968 for (count = 0, iter = t->connection_head; NULL != iter; iter = iter->next)
3969 if (CADET_CONNECTION_READY == GCC_get_state (iter->c))
3977 * Count channels of a tunnel.
3979 * @param t Tunnel on which to count.
3981 * @return Number of channels.
3984 GCT_count_channels (struct CadetTunnel *t)
3986 struct CadetTChannel *iter;
3989 for (count = 0, iter = t->channel_head;
3991 iter = iter->next, count++) /* skip */;
3998 * Get the connectivity state of a tunnel.
4002 * @return Tunnel's connectivity state.
4004 enum CadetTunnelCState
4005 GCT_get_cstate (struct CadetTunnel *t)
4010 return (enum CadetTunnelCState) -1;
4017 * Get the encryption state of a tunnel.
4021 * @return Tunnel's encryption state.
4023 enum CadetTunnelEState
4024 GCT_get_estate (struct CadetTunnel *t)
4029 return (enum CadetTunnelEState) -1;
4035 * Get the maximum buffer space for a tunnel towards a local client.
4039 * @return Biggest buffer space offered by any channel in the tunnel.
4042 GCT_get_channels_buffer (struct CadetTunnel *t)
4044 struct CadetTChannel *iter;
4045 unsigned int buffer;
4046 unsigned int ch_buf;
4048 if (NULL == t->channel_head)
4050 /* Probably getting buffer for a channel create/handshake. */
4051 LOG (GNUNET_ERROR_TYPE_DEBUG, " no channels, allow max\n");
4052 return MIN_TUNNEL_BUFFER;
4056 for (iter = t->channel_head; NULL != iter; iter = iter->next)
4058 ch_buf = get_channel_buffer (iter);
4059 if (ch_buf > buffer)
4062 if (MIN_TUNNEL_BUFFER > buffer)
4063 return MIN_TUNNEL_BUFFER;
4065 if (MAX_TUNNEL_BUFFER < buffer)
4068 return MAX_TUNNEL_BUFFER;
4075 * Get the total buffer space for a tunnel for P2P traffic.
4079 * @return Buffer space offered by all connections in the tunnel.
4082 GCT_get_connections_buffer (struct CadetTunnel *t)
4084 struct CadetTConnection *iter;
4085 unsigned int buffer;
4087 if (GNUNET_NO == is_ready (t))
4089 if (count_queued_data (t) >= 3)
4096 for (iter = t->connection_head; NULL != iter; iter = iter->next)
4098 if (GCC_get_state (iter->c) != CADET_CONNECTION_READY)
4102 buffer += get_connection_buffer (iter);
4110 * Get the tunnel's destination.
4114 * @return ID of the destination peer.
4116 const struct GNUNET_PeerIdentity *
4117 GCT_get_destination (struct CadetTunnel *t)
4119 return GCP_get_id (t->peer);
4124 * Get the tunnel's next free global channel ID.
4128 * @return GID of a channel free to use.
4131 GCT_get_next_chid (struct CadetTunnel *t)
4133 CADET_ChannelNumber chid;
4134 CADET_ChannelNumber mask;
4137 /* Set bit 30 depending on the ID relationship. Bit 31 is always 0 for GID.
4138 * If our ID is bigger or loopback tunnel, start at 0, bit 30 = 0
4139 * If peer's ID is bigger, start at 0x4... bit 30 = 1
4141 result = GNUNET_CRYPTO_cmp_peer_identity (&my_full_id, GCP_get_id (t->peer));
4146 t->next_chid |= mask;
4148 while (NULL != GCT_get_channel (t, t->next_chid))
4150 LOG (GNUNET_ERROR_TYPE_DEBUG, "Channel %u exists...\n", t->next_chid);
4151 t->next_chid = (t->next_chid + 1) & ~GNUNET_CADET_LOCAL_CHANNEL_ID_CLI;
4152 t->next_chid |= mask;
4154 chid = t->next_chid;
4155 t->next_chid = (t->next_chid + 1) & ~GNUNET_CADET_LOCAL_CHANNEL_ID_CLI;
4156 t->next_chid |= mask;
4163 * Send ACK on one or more channels due to buffer in connections.
4165 * @param t Channel which has some free buffer space.
4168 GCT_unchoke_channels (struct CadetTunnel *t)
4170 struct CadetTChannel *iter;
4171 unsigned int buffer;
4172 unsigned int channels = GCT_count_channels (t);
4173 unsigned int choked_n;
4174 struct CadetChannel *choked[channels];
4176 LOG (GNUNET_ERROR_TYPE_DEBUG, "GCT_unchoke_channels on %s\n", GCT_2s (t));
4177 LOG (GNUNET_ERROR_TYPE_DEBUG, " head: %p\n", t->channel_head);
4178 if (NULL != t->channel_head)
4179 LOG (GNUNET_ERROR_TYPE_DEBUG, " head ch: %p\n", t->channel_head->ch);
4181 if (NULL != t->tq_head)
4182 send_queued_data (t);
4184 /* Get buffer space */
4185 buffer = GCT_get_connections_buffer (t);
4191 /* Count and remember choked channels */
4193 for (iter = t->channel_head; NULL != iter; iter = iter->next)
4195 if (GNUNET_NO == get_channel_allowed (iter))
4197 choked[choked_n++] = iter->ch;
4201 /* Unchoke random channels */
4202 while (0 < buffer && 0 < choked_n)
4204 unsigned int r = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK,
4206 GCCH_allow_client (choked[r], GCCH_is_origin (choked[r], GNUNET_YES));
4209 choked[r] = choked[choked_n];
4215 * Send ACK on one or more connections due to buffer space to the client.
4217 * Iterates all connections of the tunnel and sends ACKs appropriately.
4222 GCT_send_connection_acks (struct CadetTunnel *t)
4224 struct CadetTConnection *iter;
4227 uint32_t allow_per_connection;
4229 unsigned int buffer;
4231 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel send connection ACKs on %s\n",
4240 if (CADET_TUNNEL_READY != t->cstate)
4243 buffer = GCT_get_channels_buffer (t);
4244 LOG (GNUNET_ERROR_TYPE_DEBUG, " buffer %u\n", buffer);
4246 /* Count connections, how many messages are already allowed */
4247 cs = GCT_count_connections (t);
4248 for (allowed = 0, iter = t->connection_head; NULL != iter; iter = iter->next)
4250 allowed += get_connection_allowed (iter);
4252 LOG (GNUNET_ERROR_TYPE_DEBUG, " allowed %u\n", allowed);
4254 /* Make sure there is no overflow */
4255 if (allowed > buffer)
4258 /* Authorize connections to send more data */
4259 to_allow = buffer - allowed;
4261 for (iter = t->connection_head;
4262 NULL != iter && to_allow > 0;
4265 if (CADET_CONNECTION_READY != GCC_get_state (iter->c)
4266 || get_connection_allowed (iter) > 64 / 3)
4270 allow_per_connection = to_allow/cs;
4271 to_allow -= allow_per_connection;
4273 GCC_allow (iter->c, allow_per_connection,
4274 GCC_is_origin (iter->c, GNUNET_NO));
4279 /* Since we don't allow if it's allowed to send 64/3, this can happen. */
4280 LOG (GNUNET_ERROR_TYPE_DEBUG, " reminding to_allow: %u\n", to_allow);
4286 * Cancel a previously sent message while it's in the queue.
4288 * ONLY can be called before the continuation given to the send function
4289 * is called. Once the continuation is called, the message is no longer in the
4292 * @param q Handle to the queue.
4295 GCT_cancel (struct CadetTunnelQueue *q)
4299 GNUNET_assert (NULL == q->tqd);
4301 /* tun_message_sent() will be called and free q */
4303 else if (NULL != q->tqd)
4305 unqueue_data (q->tqd);
4307 if (NULL != q->cont)
4308 q->cont (q->cont_cls, NULL, q, 0, 0);
4319 * Check if the tunnel has queued traffic.
4321 * @param t Tunnel to check.
4323 * @return #GNUNET_YES if there is queued traffic
4324 * #GNUNET_NO otherwise
4327 GCT_has_queued_traffic (struct CadetTunnel *t)
4329 return (NULL != t->tq_head) ? GNUNET_YES : GNUNET_NO;
4334 * Sends an already built message on a tunnel, encrypting it and
4335 * choosing the best connection if not provided.
4337 * @param message Message to send. Function modifies it.
4338 * @param t Tunnel on which this message is transmitted.
4339 * @param c Connection to use (autoselect if NULL).
4340 * @param force Force the tunnel to take the message (buffer overfill).
4341 * @param cont Continuation to call once message is really sent.
4342 * @param cont_cls Closure for @c cont.
4344 * @return Handle to cancel message. NULL if @c cont is NULL.
4346 struct CadetTunnelQueue *
4347 GCT_send_prebuilt_message (const struct GNUNET_MessageHeader *message,
4348 struct CadetTunnel *t, struct CadetConnection *c,
4349 int force, GCT_sent cont, void *cont_cls)
4351 return send_prebuilt_message (message, t, c, force, cont, cont_cls, NULL);
4356 * Send an Axolotl KX message.
4358 * @param t Tunnel on which to send it.
4359 * @param force_reply Force the other peer to reply with a KX message.
4362 GCT_send_ax_kx (struct CadetTunnel *t, int force_reply)
4364 struct GNUNET_CADET_AX_KX msg;
4365 enum GNUNET_CADET_AX_KX_Flags flags;
4367 LOG (GNUNET_ERROR_TYPE_INFO, "===> AX_KX for %s\n", GCT_2s (t));
4368 if (NULL != t->ephm_h)
4370 LOG (GNUNET_ERROR_TYPE_INFO, " already queued\n");
4374 msg.header.size = htons (sizeof (msg));
4375 msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_AX_KX);
4376 flags = GNUNET_CADET_AX_KX_FLAG_NONE;
4378 flags |= GNUNET_CADET_AX_KX_FLAG_FORCE_REPLY;
4379 msg.flags = htonl (flags);
4380 GNUNET_CRYPTO_ecdhe_key_get_public (t->ax->kx_0, &msg.ephemeral_key);
4381 GNUNET_CRYPTO_ecdhe_key_get_public (t->ax->DHRs, &msg.ratchet_key);
4383 t->ephm_h = send_kx (t, &msg.header);
4384 if (CADET_TUNNEL_KEY_UNINITIALIZED == t->estate)
4385 GCT_change_estate (t, CADET_TUNNEL_KEY_SENT);
4390 * Sends an already built and encrypted message on a tunnel, choosing the best
4391 * connection. Useful for re-queueing messages queued on a destroyed connection.
4393 * @param message Message to send. Function modifies it.
4394 * @param t Tunnel on which this message is transmitted.
4397 GCT_resend_message (const struct GNUNET_MessageHeader *message,
4398 struct CadetTunnel *t)
4400 struct CadetConnection *c;
4403 c = tunnel_get_connection (t);
4406 /* TODO queue in tunnel, marked as encrypted */
4407 LOG (GNUNET_ERROR_TYPE_DEBUG, "No connection available, dropping.\n");
4410 fwd = GCC_is_origin (c, GNUNET_YES);
4411 GNUNET_break (NULL == GCC_send_prebuilt_message (message, 0, 0, c, fwd,
4412 GNUNET_YES, NULL, NULL));
4417 * Is the tunnel directed towards the local peer?
4421 * @return #GNUNET_YES if it is loopback.
4424 GCT_is_loopback (const struct CadetTunnel *t)
4426 return (myid == GCP_get_short_id (t->peer));
4431 * Is the tunnel this path already?
4436 * @return #GNUNET_YES a connection uses this path.
4439 GCT_is_path_used (const struct CadetTunnel *t, const struct CadetPeerPath *p)
4441 struct CadetTConnection *iter;
4443 for (iter = t->connection_head; NULL != iter; iter = iter->next)
4444 if (path_equivalent (GCC_get_path (iter->c), p))
4452 * Get a cost of a path for a tunnel considering existing connections.
4455 * @param path Candidate path.
4457 * @return Cost of the path (path length + number of overlapping nodes)
4460 GCT_get_path_cost (const struct CadetTunnel *t,
4461 const struct CadetPeerPath *path)
4463 struct CadetTConnection *iter;
4464 const struct CadetPeerPath *aux;
4465 unsigned int overlap;
4473 GNUNET_assert (NULL != t);
4475 for (i = 0; i < path->length; i++)
4477 for (iter = t->connection_head; NULL != iter; iter = iter->next)
4479 aux = GCC_get_path (iter->c);
4483 for (j = 0; j < aux->length; j++)
4485 if (path->peers[i] == aux->peers[j])
4493 return path->length + overlap;
4498 * Get the static string for the peer this tunnel is directed.
4502 * @return Static string the destination peer's ID.
4505 GCT_2s (const struct CadetTunnel *t)
4510 return GCP_2s (t->peer);
4514 /******************************************************************************/
4515 /***************************** INFO/DEBUG *******************************/
4516 /******************************************************************************/
4519 ax_debug (const struct CadetTunnelAxolotl *ax, enum GNUNET_ErrorType level)
4521 struct GNUNET_CRYPTO_EcdhePublicKey pub;
4522 struct CadetTunnelSkippedKey *iter;
4524 LOG2 (level, "TTT RK \t %s\n",
4525 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &ax->RK));
4527 LOG2 (level, "TTT HKs \t %s\n",
4528 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &ax->HKs));
4529 LOG2 (level, "TTT HKr \t %s\n",
4530 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &ax->HKr));
4531 LOG2 (level, "TTT NHKs\t %s\n",
4532 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &ax->NHKs));
4533 LOG2 (level, "TTT NHKr\t %s\n",
4534 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &ax->NHKr));
4536 LOG2 (level, "TTT CKs \t %s\n",
4537 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &ax->CKs));
4538 LOG2 (level, "TTT CKr \t %s\n",
4539 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &ax->CKr));
4541 GNUNET_CRYPTO_ecdhe_key_get_public (ax->DHRs, &pub);
4542 LOG2 (level, "TTT DHRs\t %s\n",
4543 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &pub));
4544 LOG2 (level, "TTT DHRr\t %s\n",
4545 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &ax->DHRr));
4547 LOG2 (level, "TTT Nr\t %u\tNs\t%u\n", ax->Nr, ax->Ns);
4548 LOG2 (level, "TTT PNs\t %u\tSkipped\t%u\n", ax->PNs, ax->skipped);
4549 LOG2 (level, "TTT Ratchet\t%u\n", ax->ratchet_flag);
4551 for (iter = ax->skipped_head; NULL != iter; iter = iter->next)
4553 LOG2 (level, "TTT HK\t %s\n",
4554 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &iter->HK));
4555 LOG2 (level, "TTT MK\t %s\n",
4556 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &iter->MK));
4561 * Log all possible info about the tunnel state.
4563 * @param t Tunnel to debug.
4564 * @param level Debug level to use.
4567 GCT_debug (const struct CadetTunnel *t, enum GNUNET_ErrorType level)
4569 struct CadetTChannel *iterch;
4570 struct CadetTConnection *iterc;
4573 do_log = GNUNET_get_log_call_status (level & (~GNUNET_ERROR_TYPE_BULK),
4575 __FILE__, __FUNCTION__, __LINE__);
4579 LOG2 (level, "TTT DEBUG TUNNEL TOWARDS %s\n", GCT_2s (t));
4580 LOG2 (level, "TTT cstate %s, estate %s\n",
4581 cstate2s (t->cstate), estate2s (t->estate));
4582 LOG2 (level, "TTT kx_ctx %p, rekey_task %u, finish task %u\n",
4583 t->kx_ctx, t->rekey_task, t->kx_ctx ? t->kx_ctx->finish_task : 0);
4584 #if DUMP_KEYS_TO_STDERR
4585 if (CADET_Axolotl == t->enc_type)
4587 ax_debug (t->ax, level);
4591 LOG2 (level, "TTT my EPHM\t %s\n",
4592 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &otr_kx_msg.ephemeral_key));
4593 LOG2 (level, "TTT peers EPHM:\t %s\n",
4594 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &t->peers_ephemeral_key));
4595 LOG2 (level, "TTT ENC key:\t %s\n",
4596 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &t->e_key));
4597 LOG2 (level, "TTT DEC key:\t %s\n",
4598 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &t->d_key));
4601 LOG2 (level, "TTT OLD ENC key:\t %s\n",
4602 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &t->kx_ctx->e_key_old));
4603 LOG2 (level, "TTT OLD DEC key:\t %s\n",
4604 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &t->kx_ctx->d_key_old));
4608 LOG2 (level, "TTT tq_head %p, tq_tail %p\n", t->tq_head, t->tq_tail);
4609 LOG2 (level, "TTT destroy %p\n", t->destroy_task);
4611 LOG2 (level, "TTT channels:\n");
4612 for (iterch = t->channel_head; NULL != iterch; iterch = iterch->next)
4614 GCCH_debug (iterch->ch, level);
4617 LOG2 (level, "TTT connections:\n");
4618 for (iterc = t->connection_head; NULL != iterc; iterc = iterc->next)
4620 GCC_debug (iterc->c, level);
4623 LOG2 (level, "TTT DEBUG TUNNEL END\n");
4628 * Iterate all tunnels.
4630 * @param iter Iterator.
4631 * @param cls Closure for @c iter.
4634 GCT_iterate_all (GNUNET_CONTAINER_PeerMapIterator iter, void *cls)
4636 GNUNET_CONTAINER_multipeermap_iterate (tunnels, iter, cls);
4641 * Count all tunnels.
4643 * @return Number of tunnels to remote peers kept by this peer.
4646 GCT_count_all (void)
4648 return GNUNET_CONTAINER_multipeermap_size (tunnels);
4653 * Iterate all connections of a tunnel.
4655 * @param t Tunnel whose connections to iterate.
4656 * @param iter Iterator.
4657 * @param cls Closure for @c iter.
4660 GCT_iterate_connections (struct CadetTunnel *t, GCT_conn_iter iter, void *cls)
4662 struct CadetTConnection *ct;
4664 for (ct = t->connection_head; NULL != ct; ct = ct->next)
4670 * Iterate all channels of a tunnel.
4672 * @param t Tunnel whose channels to iterate.
4673 * @param iter Iterator.
4674 * @param cls Closure for @c iter.
4677 GCT_iterate_channels (struct CadetTunnel *t, GCT_chan_iter iter, void *cls)
4679 struct CadetTChannel *cht;
4681 for (cht = t->channel_head; NULL != cht; cht = cht->next)
4682 iter (cls, cht->ch);