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();
886 #if DUMP_KEYS_TO_STDERR
888 struct GNUNET_CRYPTO_EcdhePublicKey pub;
889 GNUNET_CRYPTO_ecdhe_key_get_public (t->ax->DHRs, &pub);
890 LOG (GNUNET_ERROR_TYPE_DEBUG, " new DHRs generated: pub %s\n",
891 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &pub));
900 * @param plaintext Content to HMAC.
901 * @param size Size of @c plaintext.
902 * @param iv Initialization vector for the message.
903 * @param key Key to use.
904 * @param hmac[out] Destination to store the HMAC.
907 t_hmac (const void *plaintext, size_t size,
908 uint32_t iv, const struct GNUNET_CRYPTO_SymmetricSessionKey *key,
909 struct GNUNET_CADET_Hash *hmac)
911 static const char ctx[] = "cadet authentication key";
912 struct GNUNET_CRYPTO_AuthKey auth_key;
913 struct GNUNET_HashCode hash;
915 #if DUMP_KEYS_TO_STDERR
916 LOG (GNUNET_ERROR_TYPE_INFO, " HMAC %u bytes with key %s\n", size,
917 GNUNET_i2s ((struct GNUNET_PeerIdentity *) key));
919 GNUNET_CRYPTO_hmac_derive_key (&auth_key, key,
924 /* Two step: CADET_Hash is only 256 bits, HashCode is 512. */
925 GNUNET_CRYPTO_hmac (&auth_key, plaintext, size, &hash);
926 memcpy (hmac, &hash, sizeof (*hmac));
931 * Encrypt daforce_newest_keyta with the tunnel key.
933 * @param t Tunnel whose key to use.
934 * @param dst Destination for the encrypted data.
935 * @param src Source of the plaintext. Can overlap with @c dst.
936 * @param size Size of the plaintext.
937 * @param iv Initialization Vector to use.
938 * @param force_newest_key Force the use of the newest key, otherwise
939 * CADET will use the old key when allowed.
940 * This can happen in the case when a KX is going on
941 * and the old one hasn't expired.
944 t_encrypt (struct CadetTunnel *t, void *dst, const void *src,
945 size_t size, uint32_t iv, int force_newest_key)
947 struct GNUNET_CRYPTO_SymmetricInitializationVector siv;
948 const struct GNUNET_CRYPTO_SymmetricSessionKey *key;
951 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_encrypt start\n");
953 key = GNUNET_YES == force_newest_key ? &t->e_key : select_key (t);
954 #if DUMP_KEYS_TO_STDERR
955 LOG (GNUNET_ERROR_TYPE_INFO, " ENC with key %s\n",
956 GNUNET_i2s ((struct GNUNET_PeerIdentity *) key));
958 GNUNET_CRYPTO_symmetric_derive_iv (&siv, key, &iv, sizeof (iv), NULL);
959 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_encrypt IV derived\n");
960 out_size = GNUNET_CRYPTO_symmetric_encrypt (src, size, key, &siv, dst);
961 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_encrypt end\n");
970 * @param key Key to use.
971 * @param hash[out] Resulting HMAC.
972 * @param source Source key material (data to HMAC).
973 * @param len Length of @a source.
976 t_ax_hmac_hash (struct GNUNET_CRYPTO_SymmetricSessionKey *key,
977 struct GNUNET_HashCode *hash,
978 void *source, unsigned int len)
980 static const char ctx[] = "axolotl HMAC-HASH";
981 struct GNUNET_CRYPTO_AuthKey auth_key;
983 GNUNET_CRYPTO_hmac_derive_key (&auth_key, key,
986 GNUNET_CRYPTO_hmac (&auth_key, source, len, hash);
991 * Derive a key from a HMAC-HASH.
993 * @param key Key to use for the HMAC.
994 * @param out Key to generate.
995 * @param source Source key material (data to HMAC).
996 * @param len Length of @a source.
999 t_hmac_derive_key (struct GNUNET_CRYPTO_SymmetricSessionKey *key,
1000 struct GNUNET_CRYPTO_SymmetricSessionKey *out,
1001 void *source, unsigned int len)
1003 static const char ctx[] = "axolotl derive key";
1004 struct GNUNET_HashCode h;
1006 t_ax_hmac_hash (key, &h, source, len);
1007 GNUNET_CRYPTO_kdf (out, sizeof (*out), ctx, sizeof (ctx),
1008 &h, sizeof (h), NULL);
1013 * Encrypt data with the axolotl tunnel key.
1015 * @param t Tunnel whose key to use.
1016 * @param dst Destination for the encrypted data.
1017 * @param src Source of the plaintext. Can overlap with @c dst.
1018 * @param size Size of the plaintext.
1020 * @return Size of the encrypted data.
1023 t_ax_encrypt (struct CadetTunnel *t, void *dst, const void *src, size_t size)
1025 struct GNUNET_CRYPTO_SymmetricSessionKey MK;
1026 struct GNUNET_CRYPTO_SymmetricInitializationVector iv;
1027 struct CadetTunnelAxolotl *ax;
1030 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_ax_encrypt start\n");
1034 ax->ratchet_counter++;
1035 if (GNUNET_YES == ax->ratchet_allowed
1036 && (ratchet_messages <= ax->ratchet_counter
1037 || 0 == GNUNET_TIME_absolute_get_remaining (ax->ratchet_expiration).rel_value_us))
1039 ax->ratchet_flag = GNUNET_YES;
1042 if (GNUNET_YES == ax->ratchet_flag)
1044 /* Advance ratchet */
1045 struct GNUNET_CRYPTO_SymmetricSessionKey keys[3];
1046 struct GNUNET_HashCode dh;
1047 struct GNUNET_HashCode hmac;
1048 static const char ctx[] = "axolotl ratchet";
1053 /* RK, NHKs, CKs = KDF( HMAC-HASH(RK, DH(DHRs, DHRr)) ) */
1054 GNUNET_CRYPTO_ecc_ecdh (ax->DHRs, &ax->DHRr, &dh);
1055 t_ax_hmac_hash (&ax->RK, &hmac, &dh, sizeof (dh));
1056 GNUNET_CRYPTO_kdf (keys, sizeof (keys), ctx, sizeof (ctx),
1057 &hmac, sizeof (hmac), NULL);
1064 ax->ratchet_flag = GNUNET_NO;
1065 ax->ratchet_allowed = GNUNET_NO;
1066 ax->ratchet_counter = 0;
1067 ax->ratchet_expiration =
1068 GNUNET_TIME_absolute_add (GNUNET_TIME_absolute_get(), ratchet_time);
1071 t_hmac_derive_key (&ax->CKs, &MK, "0", 1);
1072 GNUNET_CRYPTO_symmetric_derive_iv (&iv, &MK, NULL, 0, NULL);
1074 #if DUMP_KEYS_TO_STDERR
1075 LOG (GNUNET_ERROR_TYPE_DEBUG, " CKs: %s\n",
1076 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &ax->CKs));
1077 LOG (GNUNET_ERROR_TYPE_INFO, " AX_ENC with key %u: %s\n", ax->Ns,
1078 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &MK));
1081 out_size = GNUNET_CRYPTO_symmetric_encrypt (src, size, &MK, &iv, dst);
1083 t_hmac_derive_key (&ax->CKs, &ax->CKs, "1", 1);
1085 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_ax_encrypt end\n");
1092 * Decrypt data with the axolotl tunnel key.
1094 * @param t Tunnel whose key to use.
1095 * @param dst Destination for the decrypted data.
1096 * @param src Source of the ciphertext. Can overlap with @c dst.
1097 * @param size Size of the ciphertext.
1099 * @return Size of the decrypted data.
1102 t_ax_decrypt (struct CadetTunnel *t, void *dst, const void *src, size_t size)
1104 struct GNUNET_CRYPTO_SymmetricSessionKey MK;
1105 struct GNUNET_CRYPTO_SymmetricInitializationVector iv;
1106 struct CadetTunnelAxolotl *ax;
1109 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_ax_decrypt start\n");
1112 ax_debug (ax, GNUNET_ERROR_TYPE_INFO);
1114 t_hmac_derive_key (&ax->CKr, &MK, "0", 1);
1115 GNUNET_CRYPTO_symmetric_derive_iv (&iv, &MK, NULL, 0, NULL);
1117 #if DUMP_KEYS_TO_STDERR
1118 LOG (GNUNET_ERROR_TYPE_DEBUG, " CKr: %s\n",
1119 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &ax->CKr));
1120 LOG (GNUNET_ERROR_TYPE_INFO, " AX_DEC with key %u: %s\n", ax->Nr,
1121 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &MK));
1124 GNUNET_assert (size >= sizeof (struct GNUNET_MessageHeader));
1125 out_size = GNUNET_CRYPTO_symmetric_decrypt (src, size, &MK, &iv, dst);
1126 GNUNET_assert (out_size == size);
1128 t_hmac_derive_key (&ax->CKr, &ax->CKr, "1", 1);
1130 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_ax_decrypt end\n");
1137 * Encrypt header with the axolotl header key.
1139 * @param t Tunnel whose key to use.
1140 * @param msg Message whose header to encrypt.
1143 t_h_encrypt (struct CadetTunnel *t, struct GNUNET_CADET_AX *msg)
1145 struct GNUNET_CRYPTO_SymmetricInitializationVector iv;
1146 struct CadetTunnelAxolotl *ax;
1149 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_h_encrypt start\n");
1152 GNUNET_CRYPTO_symmetric_derive_iv (&iv, &ax->HKs, NULL, 0, NULL);
1154 #if DUMP_KEYS_TO_STDERR
1155 LOG (GNUNET_ERROR_TYPE_INFO, " AX_ENC_H with key %s\n",
1156 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &ax->HKs));
1159 out_size = GNUNET_CRYPTO_symmetric_encrypt (&msg->Ns, AX_HEADER_SIZE,
1160 &ax->HKs, &iv, &msg->Ns);
1162 GNUNET_assert (AX_HEADER_SIZE == out_size);
1164 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_ax_encrypt end\n");
1169 * Decrypt header with the current axolotl header key.
1171 * @param t Tunnel whose current ax HK to use.
1172 * @param src Message whose header to decrypt.
1173 * @param dst Where to decrypt header to.
1176 t_h_decrypt (struct CadetTunnel *t, const struct GNUNET_CADET_AX *src,
1177 struct GNUNET_CADET_AX *dst)
1179 struct GNUNET_CRYPTO_SymmetricInitializationVector iv;
1180 struct CadetTunnelAxolotl *ax;
1183 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_h_decrypt start\n");
1186 GNUNET_CRYPTO_symmetric_derive_iv (&iv, &ax->HKr, NULL, 0, NULL);
1188 #if DUMP_KEYS_TO_STDERR
1189 LOG (GNUNET_ERROR_TYPE_INFO, " AX_DEC_H with key %s\n",
1190 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &ax->HKr));
1193 out_size = GNUNET_CRYPTO_symmetric_decrypt (&src->Ns, AX_HEADER_SIZE,
1194 &ax->HKr, &iv, &dst->Ns);
1196 GNUNET_assert (AX_HEADER_SIZE == out_size);
1198 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_h_decrypt end\n");
1203 * Decrypt and verify data with the appropriate tunnel key.
1205 * @param key Key to use.
1206 * @param dst Destination for the plaintext.
1207 * @param src Source of the encrypted data. Can overlap with @c dst.
1208 * @param size Size of the encrypted data.
1209 * @param iv Initialization Vector to use.
1211 * @return Size of the decrypted data, -1 if an error was encountered.
1214 decrypt (const struct GNUNET_CRYPTO_SymmetricSessionKey *key,
1215 void *dst, const void *src, size_t size, uint32_t iv)
1217 struct GNUNET_CRYPTO_SymmetricInitializationVector siv;
1220 LOG (GNUNET_ERROR_TYPE_DEBUG, " decrypt start\n");
1221 LOG (GNUNET_ERROR_TYPE_DEBUG, " decrypt iv\n");
1222 GNUNET_CRYPTO_symmetric_derive_iv (&siv, key, &iv, sizeof (iv), NULL);
1223 LOG (GNUNET_ERROR_TYPE_DEBUG, " decrypt iv done\n");
1224 out_size = GNUNET_CRYPTO_symmetric_decrypt (src, size, key, &siv, dst);
1225 LOG (GNUNET_ERROR_TYPE_DEBUG, " decrypt end\n");
1232 * Decrypt and verify data with the most recent tunnel key.
1234 * @param t Tunnel whose key to use.
1235 * @param dst Destination for the plaintext.
1236 * @param src Source of the encrypted data. Can overlap with @c dst.
1237 * @param size Size of the encrypted data.
1238 * @param iv Initialization Vector to use.
1240 * @return Size of the decrypted data, -1 if an error was encountered.
1243 t_decrypt (struct CadetTunnel *t, void *dst, const void *src,
1244 size_t size, uint32_t iv)
1248 #if DUMP_KEYS_TO_STDERR
1249 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_decrypt with %s\n",
1250 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &t->d_key));
1252 if (CADET_TUNNEL_KEY_UNINITIALIZED == t->estate)
1254 GNUNET_STATISTICS_update (stats, "# non decryptable data", 1, GNUNET_NO);
1255 LOG (GNUNET_ERROR_TYPE_WARNING,
1256 "got data on %s without a valid key\n",
1258 GCT_debug (t, GNUNET_ERROR_TYPE_WARNING);
1262 out_size = decrypt (&t->d_key, dst, src, size, iv);
1269 * Decrypt and verify data with the appropriate tunnel key and verify that the
1270 * data has not been altered since it was sent by the remote peer.
1272 * @param t Tunnel whose key to use.
1273 * @param dst Destination for the plaintext.
1274 * @param src Source of the encrypted data. Can overlap with @c dst.
1275 * @param size Size of the encrypted data.
1276 * @param iv Initialization Vector to use.
1277 * @param msg_hmac HMAC of the message, cannot be NULL.
1279 * @return Size of the decrypted data, -1 if an error was encountered.
1282 t_decrypt_and_validate (struct CadetTunnel *t,
1283 void *dst, const void *src,
1284 size_t size, uint32_t iv,
1285 const struct GNUNET_CADET_Hash *msg_hmac)
1287 struct GNUNET_CRYPTO_SymmetricSessionKey *key;
1288 struct GNUNET_CADET_Hash hmac;
1291 /* Try primary (newest) key */
1293 decrypted_size = decrypt (key, dst, src, size, iv);
1294 t_hmac (src, size, iv, key, &hmac);
1295 if (0 == memcmp (msg_hmac, &hmac, sizeof (hmac)))
1296 return decrypted_size;
1298 /* If no key exchange is going on, we just failed. */
1299 if (NULL == t->kx_ctx)
1301 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
1302 "Failed checksum validation on tunnel %s with no KX\n",
1304 GNUNET_STATISTICS_update (stats, "# wrong HMAC no KX", 1, GNUNET_NO);
1308 /* Try secondary key, from previous KX period. */
1309 key = &t->kx_ctx->d_key_old;
1310 decrypted_size = decrypt (key, dst, src, size, iv);
1311 t_hmac (src, size, iv, key, &hmac);
1312 if (0 == memcmp (msg_hmac, &hmac, sizeof (hmac)))
1313 return decrypted_size;
1315 /* Hail Mary, try tertiary, key, in case of parallel re-keys. */
1316 key = &t->kx_ctx->d_key_old2;
1317 decrypted_size = decrypt (key, dst, src, size, iv);
1318 t_hmac (src, size, iv, key, &hmac);
1319 if (0 == memcmp (msg_hmac, &hmac, sizeof (hmac)))
1320 return decrypted_size;
1322 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
1323 "Failed checksum validation on tunnel %s with KX\n",
1325 GNUNET_STATISTICS_update (stats, "# wrong HMAC with KX", 1, GNUNET_NO);
1331 * Decrypt and verify data with the appropriate tunnel key and verify that the
1332 * data has not been altered since it was sent by the remote peer.
1334 * @param t Tunnel whose key to use.
1335 * @param dst Destination for the plaintext.
1336 * @param src Source of the message. Can overlap with @c dst.
1337 * @param size Size of the message.
1339 * @return Size of the decrypted data, -1 if an error was encountered.
1342 try_old_ax_keys (struct CadetTunnel *t, void *dst,
1343 const struct GNUNET_CADET_AX *src, size_t size)
1345 struct CadetTunnelSkippedKey *key;
1346 struct GNUNET_CADET_Hash *hmac;
1347 struct GNUNET_CRYPTO_SymmetricInitializationVector iv;
1348 struct GNUNET_CADET_AX plaintext_header;
1349 struct GNUNET_CRYPTO_SymmetricSessionKey *valid_HK;
1355 LOG (GNUNET_ERROR_TYPE_DEBUG, "Trying old keys\n");
1356 hmac = &plaintext_header.hmac;
1357 esize = size - sizeof (struct GNUNET_CADET_AX);
1359 /* Find a correct Header Key */
1360 for (key = t->ax->skipped_head; NULL != key; key = key->next)
1362 #if DUMP_KEYS_TO_STDERR
1363 LOG (GNUNET_ERROR_TYPE_DEBUG, " Trying hmac with key %s\n",
1364 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &key->HK));
1366 t_hmac (&src->Ns, AX_HEADER_SIZE + esize, 0, &key->HK, hmac);
1367 if (0 == memcmp (hmac, &src->hmac, sizeof (*hmac)))
1369 LOG (GNUNET_ERROR_TYPE_DEBUG, " hmac correct\n");
1370 valid_HK = &key->HK;
1377 /* Should've been checked in -cadet_connection.c handle_cadet_encrypted. */
1378 GNUNET_assert (size > sizeof (struct GNUNET_CADET_AX));
1379 len = size - sizeof (struct GNUNET_CADET_AX);
1380 GNUNET_assert (len >= sizeof (struct GNUNET_MessageHeader));
1382 /* Decrypt header */
1383 GNUNET_CRYPTO_symmetric_derive_iv (&iv, &key->HK, NULL, 0, NULL);
1384 res = GNUNET_CRYPTO_symmetric_decrypt (&src->Ns, AX_HEADER_SIZE,
1385 &key->HK, &iv, &plaintext_header.Ns);
1386 GNUNET_assert (AX_HEADER_SIZE == res);
1387 LOG (GNUNET_ERROR_TYPE_DEBUG, " Message %u, previous: %u\n",
1388 ntohl (plaintext_header.Ns), ntohl (plaintext_header.PNs));
1390 /* Find the correct Message Key */
1391 N = ntohl (plaintext_header.Ns);
1392 while (NULL != key && N != key->Kn)
1394 if (NULL == key || 0 != memcmp (&key->HK, valid_HK, sizeof (*valid_HK)))
1397 #if DUMP_KEYS_TO_STDERR
1398 LOG (GNUNET_ERROR_TYPE_INFO, " AX_DEC_H with skipped key %s\n",
1399 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &key->HK));
1400 LOG (GNUNET_ERROR_TYPE_INFO, " AX_DEC with skipped key %u: %s\n",
1401 key->Kn, GNUNET_i2s ((struct GNUNET_PeerIdentity *) &key->MK));
1404 /* Decrypt payload */
1405 GNUNET_CRYPTO_symmetric_derive_iv (&iv, &key->MK, NULL, 0, NULL);
1406 res = GNUNET_CRYPTO_symmetric_decrypt (&src[1], len, &key->MK, &iv, dst);
1409 GNUNET_CONTAINER_DLL_remove (t->ax->skipped_head, t->ax->skipped_tail, key);
1411 GNUNET_free (key); /* GNUNET_free overwrites memory with 0xbaadf00d */
1418 * Delete a key from the list of skipped keys.
1420 * @param t Tunnel to delete from.
1421 * @param HKr Header Key to use.
1424 store_skipped_key (struct CadetTunnel *t,
1425 const struct GNUNET_CRYPTO_SymmetricSessionKey *HKr)
1427 struct CadetTunnelSkippedKey *key;
1429 key = GNUNET_new (struct CadetTunnelSkippedKey);
1430 key->timestamp = GNUNET_TIME_absolute_get ();
1431 key->Kn = t->ax->Nr;
1432 key->HK = t->ax->HKr;
1433 t_hmac_derive_key (&t->ax->CKr, &key->MK, "0", 1);
1434 #if DUMP_KEYS_TO_STDERR
1435 LOG (GNUNET_ERROR_TYPE_DEBUG, " storing MK for Nr %u: %s\n",
1436 key->Kn, GNUNET_i2s ((struct GNUNET_PeerIdentity *) &key->MK));
1437 LOG (GNUNET_ERROR_TYPE_DEBUG, " for CKr: %s\n",
1438 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &t->ax->CKr));
1440 t_hmac_derive_key (&t->ax->CKr, &t->ax->CKr, "1", 1);
1441 GNUNET_CONTAINER_DLL_insert (t->ax->skipped_head, t->ax->skipped_tail, key);
1448 * Delete a key from the list of skipped keys.
1450 * @param t Tunnel to delete from.
1451 * @param key Key to delete.
1454 delete_skipped_key (struct CadetTunnel *t, struct CadetTunnelSkippedKey *key)
1456 GNUNET_CONTAINER_DLL_remove (t->ax->skipped_head, t->ax->skipped_tail, key);
1463 * Stage skipped AX keys and calculate the message key.
1465 * Stores each HK and MK for skipped messages.
1467 * @param t Tunnel where to stage the keys.
1468 * @param HKr Header key.
1469 * @param Np Received meesage number.
1471 * @return GNUNET_OK if keys were stored.
1472 * GNUNET_SYSERR if an error ocurred (Np not expected).
1475 store_ax_keys (struct CadetTunnel *t,
1476 const struct GNUNET_CRYPTO_SymmetricSessionKey *HKr,
1482 gap = Np - t->ax->Nr;
1483 LOG (GNUNET_ERROR_TYPE_INFO, "Storing keys [%u, %u)\n", t->ax->Nr, Np);
1484 if (MAX_KEY_GAP < gap)
1486 /* Avoid DoS (forcing peer to do 2*33 chain HMAC operations) */
1487 /* TODO: start new key exchange on return */
1488 GNUNET_break_op (0);
1489 LOG (GNUNET_ERROR_TYPE_WARNING, "Got message %u, expected %u+\n",
1491 return GNUNET_SYSERR;
1495 /* Delayed message: don't store keys, flag to try old keys. */
1496 return GNUNET_SYSERR;
1499 while (t->ax->Nr < Np)
1500 store_skipped_key (t, HKr);
1502 while (t->ax->skipped > MAX_SKIPPED_KEYS)
1503 delete_skipped_key (t, t->ax->skipped_tail);
1510 * Decrypt and verify data with the appropriate tunnel key and verify that the
1511 * data has not been altered since it was sent by the remote peer.
1513 * @param t Tunnel whose key to use.
1514 * @param dst Destination for the plaintext.
1515 * @param src Source of the message. Can overlap with @c dst.
1516 * @param size Size of the message.
1518 * @return Size of the decrypted data, -1 if an error was encountered.
1521 t_ax_decrypt_and_validate (struct CadetTunnel *t, void *dst,
1522 const struct GNUNET_CADET_AX *src, size_t size)
1524 struct CadetTunnelAxolotl *ax;
1525 struct GNUNET_CADET_Hash msg_hmac;
1526 struct GNUNET_HashCode hmac;
1527 struct GNUNET_CADET_AX plaintext_header;
1534 esize = size - sizeof (struct GNUNET_CADET_AX);
1539 /* Try current HK */
1540 t_hmac (&src->Ns, AX_HEADER_SIZE + esize, 0, &ax->HKr, &msg_hmac);
1541 if (0 != memcmp (&msg_hmac, &src->hmac, sizeof (msg_hmac)))
1543 static const char ctx[] = "axolotl ratchet";
1544 struct GNUNET_CRYPTO_SymmetricSessionKey keys[3]; /* RKp, NHKp, CKp */
1545 struct GNUNET_CRYPTO_SymmetricSessionKey HK;
1546 struct GNUNET_HashCode dh;
1547 struct GNUNET_CRYPTO_EcdhePublicKey *DHRp;
1550 LOG (GNUNET_ERROR_TYPE_DEBUG, " trying next HK\n");
1551 t_hmac (&src->Ns, AX_HEADER_SIZE + esize, 0, &ax->NHKr, &msg_hmac);
1552 if (0 != memcmp (&msg_hmac, &src->hmac, sizeof (msg_hmac)))
1554 /* Try the skipped keys, if that fails, we're out of luck. */
1555 return try_old_ax_keys (t, dst, src, size);
1557 LOG (GNUNET_ERROR_TYPE_INFO, "next HK worked\n");
1561 t_h_decrypt (t, src, &plaintext_header);
1562 Np = ntohl (plaintext_header.Ns);
1563 PNp = ntohl (plaintext_header.PNs);
1564 DHRp = &plaintext_header.DHRs;
1565 store_ax_keys (t, &HK, PNp);
1567 /* RKp, NHKp, CKp = KDF (HMAC-HASH (RK, DH (DHRp, DHRs))) */
1568 GNUNET_CRYPTO_ecc_ecdh (ax->DHRs, DHRp, &dh);
1569 t_ax_hmac_hash (&ax->RK, &hmac, &dh, sizeof (dh));
1570 GNUNET_CRYPTO_kdf (keys, sizeof (keys), ctx, sizeof (ctx),
1571 &hmac, sizeof (hmac), NULL);
1573 /* Commit "purported" keys */
1579 ax->ratchet_allowed = GNUNET_YES;
1583 LOG (GNUNET_ERROR_TYPE_DEBUG, "current HK\n");
1584 t_h_decrypt (t, src, &plaintext_header);
1585 Np = ntohl (plaintext_header.Ns);
1586 PNp = ntohl (plaintext_header.PNs);
1588 LOG (GNUNET_ERROR_TYPE_INFO, " got AX Nr %u\n", Np);
1590 if (GNUNET_OK != store_ax_keys (t, &ax->HKr, Np))
1591 /* Try the skipped keys, if that fails, we're out of luck. */
1592 return try_old_ax_keys (t, dst, src, size);
1594 osize = t_ax_decrypt (t, dst, &src[1], esize);
1599 GNUNET_break_op (0);
1608 * Create key material by doing ECDH on the local and remote ephemeral keys.
1610 * @param key_material Where to store the key material.
1611 * @param ephemeral Peer's public ephemeral key.
1613 * @return GNUNET_OK if it went fine, GNUNET_SYSERR otherwise.
1616 derive_otr_key_material (struct GNUNET_HashCode *key_material,
1617 const struct GNUNET_CRYPTO_EcdhePublicKey *ephemeral)
1620 GNUNET_CRYPTO_ecc_ecdh (otr_ephemeral_key, ephemeral, key_material))
1623 return GNUNET_SYSERR;
1630 * Create a symmetic key from the identities of both ends and the key material
1633 * @param key Destination for the generated key.
1634 * @param sender ID of the peer that will encrypt with @c key.
1635 * @param receiver ID of the peer that will decrypt with @c key.
1636 * @param key_material Hash created with ECDH with the ephemeral keys.
1639 derive_symmertic (struct GNUNET_CRYPTO_SymmetricSessionKey *key,
1640 const struct GNUNET_PeerIdentity *sender,
1641 const struct GNUNET_PeerIdentity *receiver,
1642 const struct GNUNET_HashCode *key_material)
1644 const char salt[] = "CADET kx salt";
1646 GNUNET_CRYPTO_kdf (key, sizeof (struct GNUNET_CRYPTO_SymmetricSessionKey),
1647 salt, sizeof (salt),
1648 key_material, sizeof (struct GNUNET_HashCode),
1649 sender, sizeof (struct GNUNET_PeerIdentity),
1650 receiver, sizeof (struct GNUNET_PeerIdentity),
1656 * Derive the tunnel's keys using our own and the peer's ephemeral keys.
1658 * @param t Tunnel for which to create the keys.
1660 * @return GNUNET_OK if successful, GNUNET_SYSERR otherwise.
1663 create_otr_keys (struct CadetTunnel *t)
1665 struct GNUNET_HashCode km;
1667 if (GNUNET_OK != derive_otr_key_material (&km, &t->peers_ephemeral_key))
1668 return GNUNET_SYSERR;
1669 derive_symmertic (&t->e_key, &my_full_id, GCP_get_id (t->peer), &km);
1670 derive_symmertic (&t->d_key, GCP_get_id (t->peer), &my_full_id, &km);
1671 #if DUMP_KEYS_TO_STDERR
1672 LOG (GNUNET_ERROR_TYPE_INFO, "ME: %s\n",
1673 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &otr_kx_msg.ephemeral_key));
1674 LOG (GNUNET_ERROR_TYPE_INFO, "PE: %s\n",
1675 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &t->peers_ephemeral_key));
1676 LOG (GNUNET_ERROR_TYPE_INFO, "KM: %s\n", GNUNET_h2s (&km));
1677 LOG (GNUNET_ERROR_TYPE_INFO, "EK: %s\n",
1678 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &t->e_key));
1679 LOG (GNUNET_ERROR_TYPE_INFO, "DK: %s\n",
1680 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &t->d_key));
1687 * Create a new Key eXchange context for the tunnel.
1689 * If the old keys were verified, keep them for old traffic. Create a new KX
1690 * timestamp and a new nonce.
1692 * @param t Tunnel for which to create the KX ctx.
1694 * @return GNUNET_OK if successful, GNUNET_SYSERR otherwise.
1697 create_kx_ctx (struct CadetTunnel *t)
1699 LOG (GNUNET_ERROR_TYPE_INFO, " new kx ctx for %s\n", GCT_2s (t));
1701 if (NULL != t->kx_ctx)
1703 if (NULL != t->kx_ctx->finish_task)
1705 LOG (GNUNET_ERROR_TYPE_INFO, " resetting exisiting finish task\n");
1706 GNUNET_SCHEDULER_cancel (t->kx_ctx->finish_task);
1707 t->kx_ctx->finish_task = NULL;
1712 t->kx_ctx = GNUNET_new (struct CadetTunnelKXCtx);
1713 t->kx_ctx->challenge = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE,
1717 if (CADET_TUNNEL_KEY_OK == t->estate)
1719 LOG (GNUNET_ERROR_TYPE_INFO, " backing up keys\n");
1720 t->kx_ctx->d_key_old = t->d_key;
1721 t->kx_ctx->e_key_old = t->e_key;
1724 LOG (GNUNET_ERROR_TYPE_INFO, " old keys not valid, not saving\n");
1725 t->kx_ctx->rekey_start_time = GNUNET_TIME_absolute_get ();
1726 return create_otr_keys (t);
1731 * @brief Finish the Key eXchange and destroy the old keys.
1733 * @param cls Closure (Tunnel for which to finish the KX).
1734 * @param tc Task context.
1737 finish_kx (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
1739 struct CadetTunnel *t = cls;
1741 LOG (GNUNET_ERROR_TYPE_INFO, "finish KX for %s\n", GCT_2s (t));
1743 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
1745 LOG (GNUNET_ERROR_TYPE_INFO, " shutdown\n");
1749 GNUNET_free (t->kx_ctx);
1755 * Destroy a Key eXchange context for the tunnel. This function only schedules
1756 * the destruction, the freeing of the memory (and clearing of old key material)
1757 * happens after a delay!
1759 * @param t Tunnel whose KX ctx to destroy.
1762 destroy_kx_ctx (struct CadetTunnel *t)
1764 struct GNUNET_TIME_Relative delay;
1766 if (NULL == t->kx_ctx || NULL != t->kx_ctx->finish_task)
1769 if (is_key_null (&t->kx_ctx->e_key_old))
1771 t->kx_ctx->finish_task = GNUNET_SCHEDULER_add_now (finish_kx, t);
1775 delay = GNUNET_TIME_relative_divide (rekey_period, 4);
1776 delay = GNUNET_TIME_relative_min (delay, GNUNET_TIME_UNIT_MINUTES);
1778 t->kx_ctx->finish_task = GNUNET_SCHEDULER_add_delayed (delay, finish_kx, t);
1784 * Pick a connection on which send the next data message.
1786 * @param t Tunnel on which to send the message.
1788 * @return The connection on which to send the next message.
1790 static struct CadetConnection *
1791 tunnel_get_connection (struct CadetTunnel *t)
1793 struct CadetTConnection *iter;
1794 struct CadetConnection *best;
1796 unsigned int lowest_q;
1798 LOG (GNUNET_ERROR_TYPE_DEBUG, "tunnel_get_connection %s\n", GCT_2s (t));
1800 lowest_q = UINT_MAX;
1801 for (iter = t->connection_head; NULL != iter; iter = iter->next)
1803 LOG (GNUNET_ERROR_TYPE_DEBUG, " connection %s: %u\n",
1804 GCC_2s (iter->c), GCC_get_state (iter->c));
1805 if (CADET_CONNECTION_READY == GCC_get_state (iter->c))
1807 qn = GCC_get_qn (iter->c, GCC_is_origin (iter->c, GNUNET_YES));
1808 LOG (GNUNET_ERROR_TYPE_DEBUG, " q_n %u, \n", qn);
1816 LOG (GNUNET_ERROR_TYPE_DEBUG, " selected: connection %s\n", GCC_2s (best));
1822 * Callback called when a queued message is sent.
1824 * Calculates the average time and connection packet tracking.
1826 * @param cls Closure (TunnelQueue handle).
1827 * @param c Connection this message was on.
1828 * @param q Connection queue handle (unused).
1829 * @param type Type of message sent.
1830 * @param fwd Was this a FWD going message?
1831 * @param size Size of the message.
1834 tun_message_sent (void *cls,
1835 struct CadetConnection *c,
1836 struct CadetConnectionQueue *q,
1837 uint16_t type, int fwd, size_t size)
1839 struct CadetTunnelQueue *qt = cls;
1840 struct CadetTunnel *t;
1842 LOG (GNUNET_ERROR_TYPE_DEBUG, "tun_message_sent\n");
1844 GNUNET_assert (NULL != qt->cont);
1845 t = NULL == c ? NULL : GCC_get_tunnel (c);
1846 qt->cont (qt->cont_cls, t, qt, type, size);
1852 count_queued_data (const struct CadetTunnel *t)
1854 struct CadetTunnelDelayed *iter;
1857 for (count = 0, iter = t->tq_head; iter != NULL; iter = iter->next)
1864 * Delete a queued message: either was sent or the channel was destroyed
1865 * before the tunnel's key exchange had a chance to finish.
1867 * @param tqd Delayed queue handle.
1870 unqueue_data (struct CadetTunnelDelayed *tqd)
1872 GNUNET_CONTAINER_DLL_remove (tqd->t->tq_head, tqd->t->tq_tail, tqd);
1878 * Cache a message to be sent once tunnel is online.
1880 * @param t Tunnel to hold the message.
1881 * @param msg Message itself (copy will be made).
1883 static struct CadetTunnelDelayed *
1884 queue_data (struct CadetTunnel *t, const struct GNUNET_MessageHeader *msg)
1886 struct CadetTunnelDelayed *tqd;
1887 uint16_t size = ntohs (msg->size);
1889 LOG (GNUNET_ERROR_TYPE_DEBUG, "queue data on Tunnel %s\n", GCT_2s (t));
1891 GNUNET_assert (GNUNET_NO == is_ready (t));
1893 tqd = GNUNET_malloc (sizeof (struct CadetTunnelDelayed) + size);
1896 memcpy (&tqd[1], msg, size);
1897 GNUNET_CONTAINER_DLL_insert_tail (t->tq_head, t->tq_tail, tqd);
1903 * Sends an already built message on a tunnel, encrypting it and
1904 * choosing the best connection.
1906 * @param message Message to send. Function modifies it.
1907 * @param t Tunnel on which this message is transmitted.
1908 * @param c Connection to use (autoselect if NULL).
1909 * @param force Force the tunnel to take the message (buffer overfill).
1910 * @param cont Continuation to call once message is really sent.
1911 * @param cont_cls Closure for @c cont.
1912 * @param existing_q In case this a transmission of previously queued data,
1913 * this should be TunnelQueue given to the client.
1916 * @return Handle to cancel message.
1917 * NULL if @c cont is NULL or an error happens and message is dropped.
1919 static struct CadetTunnelQueue *
1920 send_prebuilt_message (const struct GNUNET_MessageHeader *message,
1921 struct CadetTunnel *t, struct CadetConnection *c,
1922 int force, GCT_sent cont, void *cont_cls,
1923 struct CadetTunnelQueue *existing_q)
1925 struct GNUNET_MessageHeader *msg;
1926 struct GNUNET_CADET_Encrypted *otr_msg;
1927 struct GNUNET_CADET_AX *ax_msg;
1928 struct CadetTunnelQueue *tq;
1929 size_t size = ntohs (message->size);
1930 const uint16_t max_overhead = sizeof (struct GNUNET_CADET_Encrypted)
1931 + sizeof (struct GNUNET_CADET_AX);
1932 char cbuf[max_overhead + size];
1939 LOG (GNUNET_ERROR_TYPE_DEBUG, "GMT Send on Tunnel %s\n", GCT_2s (t));
1941 if (GNUNET_NO == is_ready (t))
1943 struct CadetTunnelDelayed *tqd;
1944 /* A non null existing_q indicates sending of queued data.
1945 * Should only happen after tunnel becomes ready.
1947 GNUNET_assert (NULL == existing_q);
1948 tqd = queue_data (t, message);
1951 tq = GNUNET_new (struct CadetTunnelQueue);
1955 tq->cont_cls = cont_cls;
1959 GNUNET_assert (GNUNET_NO == GCT_is_loopback (t));
1961 if (CADET_Axolotl == t->enc_type)
1963 ax_msg = (struct GNUNET_CADET_AX *) cbuf;
1964 msg = &ax_msg->header;
1965 msg->size = htons (sizeof (struct GNUNET_CADET_AX) + size);
1966 msg->type = htons (GNUNET_MESSAGE_TYPE_CADET_AX);
1967 ax_msg->reserved = 0;
1968 esize = t_ax_encrypt (t, &ax_msg[1], message, size);
1969 ax_msg->Ns = htonl (t->ax->Ns++);
1970 ax_msg->PNs = htonl (t->ax->PNs);
1971 GNUNET_CRYPTO_ecdhe_key_get_public (t->ax->DHRs, &ax_msg->DHRs);
1972 t_h_encrypt (t, ax_msg);
1973 t_hmac (&ax_msg->Ns, AX_HEADER_SIZE + esize, 0, &t->ax->HKs, &ax_msg->hmac);
1977 otr_msg = (struct GNUNET_CADET_Encrypted *) cbuf;
1978 msg = &otr_msg->header;
1979 iv = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX);
1981 esize = t_encrypt (t, &otr_msg[1], message, size, iv, GNUNET_NO);
1982 t_hmac (&otr_msg[1], size, iv, select_key (t), &otr_msg->hmac);
1983 msg->size = htons (sizeof (struct GNUNET_CADET_Encrypted) + size);
1984 msg->type = htons (GNUNET_MESSAGE_TYPE_CADET_ENCRYPTED);
1985 otr_msg->ttl = htonl (default_ttl);
1987 GNUNET_assert (esize == size);
1990 c = tunnel_get_connection (t);
1993 /* Why is tunnel 'ready'? Should have been queued! */
1994 if (NULL != t->destroy_task)
1997 GCT_debug (t, GNUNET_ERROR_TYPE_WARNING);
1999 return NULL; /* Drop... */
2003 type = ntohs (message->type);
2006 case GNUNET_MESSAGE_TYPE_CADET_DATA:
2007 case GNUNET_MESSAGE_TYPE_CADET_DATA_ACK:
2008 if (GNUNET_MESSAGE_TYPE_CADET_DATA == type)
2009 mid = ntohl (((struct GNUNET_CADET_Data *) message)->mid);
2011 mid = ntohl (((struct GNUNET_CADET_DataACK *) message)->mid);
2013 case GNUNET_MESSAGE_TYPE_CADET_KEEPALIVE:
2014 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_CREATE:
2015 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_DESTROY:
2016 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_ACK:
2017 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_NACK:
2021 LOG (GNUNET_ERROR_TYPE_ERROR, "type %s not valid\n", GC_m2s (type));
2023 LOG (GNUNET_ERROR_TYPE_DEBUG, "type %s\n", GC_m2s (type));
2025 fwd = GCC_is_origin (c, GNUNET_YES);
2029 GNUNET_break (NULL == GCC_send_prebuilt_message (msg, type, mid, c, fwd,
2030 force, NULL, NULL));
2033 if (NULL == existing_q)
2035 tq = GNUNET_new (struct CadetTunnelQueue); /* FIXME valgrind: leak*/
2042 tq->cq = GCC_send_prebuilt_message (msg, type, mid, c, fwd, force,
2043 &tun_message_sent, tq);
2044 GNUNET_assert (NULL != tq->cq);
2046 tq->cont_cls = cont_cls;
2053 * Send all cached messages that we can, tunnel is online.
2055 * @param t Tunnel that holds the messages. Cannot be loopback.
2058 send_queued_data (struct CadetTunnel *t)
2060 struct CadetTunnelDelayed *tqd;
2061 struct CadetTunnelDelayed *next;
2064 LOG (GNUNET_ERROR_TYPE_INFO, "Send queued data, tunnel %s\n", GCT_2s (t));
2066 if (GCT_is_loopback (t))
2072 if (GNUNET_NO == is_ready (t))
2074 LOG (GNUNET_ERROR_TYPE_WARNING, " not ready yet: %s/%s\n",
2075 estate2s (t->estate), cstate2s (t->cstate));
2079 room = GCT_get_connections_buffer (t);
2080 LOG (GNUNET_ERROR_TYPE_DEBUG, " buffer space: %u\n", room);
2081 LOG (GNUNET_ERROR_TYPE_DEBUG, " tq head: %p\n", t->tq_head);
2082 for (tqd = t->tq_head; NULL != tqd && room > 0; tqd = next)
2084 LOG (GNUNET_ERROR_TYPE_DEBUG, " sending queued data\n");
2087 send_prebuilt_message ((struct GNUNET_MessageHeader *) &tqd[1],
2088 tqd->t, NULL, GNUNET_YES,
2089 NULL != tqd->tq ? tqd->tq->cont : NULL,
2090 NULL != tqd->tq ? tqd->tq->cont_cls : NULL,
2094 LOG (GNUNET_ERROR_TYPE_DEBUG, "GCT_send_queued_data end\n", GCP_2s (t->peer));
2099 * @brief Resend the AX KX until we complete the handshake.
2101 * @param cls Closure (tunnel).
2102 * @param tc Task context.
2105 ax_kx_resend (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
2107 struct CadetTunnel *t = cls;
2109 t->rekey_task = NULL;
2111 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
2114 if (CADET_TUNNEL_KEY_OK == t->estate)
2116 /* Should have been canceled on estate change */
2121 GCT_send_ax_kx (t, GNUNET_YES);
2126 * Callback called when a queued message is sent.
2128 * @param cls Closure.
2129 * @param c Connection this message was on.
2130 * @param type Type of message sent.
2131 * @param fwd Was this a FWD going message?
2132 * @param size Size of the message.
2135 ephm_sent (void *cls,
2136 struct CadetConnection *c,
2137 struct CadetConnectionQueue *q,
2138 uint16_t type, int fwd, size_t size)
2140 struct CadetTunnel *t = cls;
2141 LOG (GNUNET_ERROR_TYPE_DEBUG, "ephemeral sent %s\n", GC_m2s (type));
2145 if (CADET_TUNNEL_KEY_OK == t->estate)
2148 if (CADET_Axolotl == t->enc_type)
2150 if (NULL != t->rekey_task)
2153 GCT_debug (t, GNUNET_ERROR_TYPE_WARNING);
2154 GNUNET_SCHEDULER_cancel (t->rekey_task);
2156 t->rekey_task = GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_SECONDS,
2163 * Callback called when a queued message is sent.
2165 * @param cls Closure.
2166 * @param c Connection this message was on.
2167 * @param type Type of message sent.
2168 * @param fwd Was this a FWD going message?
2169 * @param size Size of the message.
2172 pong_sent (void *cls,
2173 struct CadetConnection *c,
2174 struct CadetConnectionQueue *q,
2175 uint16_t type, int fwd, size_t size)
2177 struct CadetTunnel *t = cls;
2178 LOG (GNUNET_ERROR_TYPE_DEBUG, "pong_sent %s\n", GC_m2s (type));
2185 * Sends key exchange message on a tunnel, choosing the best connection.
2186 * Should not be called on loopback tunnels.
2188 * @param t Tunnel on which this message is transmitted.
2189 * @param message Message to send. Function modifies it.
2191 * @return Handle to the message in the connection queue.
2193 static struct CadetConnectionQueue *
2194 send_kx (struct CadetTunnel *t,
2195 const struct GNUNET_MessageHeader *message)
2197 struct CadetConnection *c;
2198 struct GNUNET_CADET_KX *msg;
2199 size_t size = ntohs (message->size);
2200 char cbuf[sizeof (struct GNUNET_CADET_KX) + size];
2205 LOG (GNUNET_ERROR_TYPE_DEBUG, "GMT KX on Tunnel %s\n", GCT_2s (t));
2207 /* Avoid loopback. */
2208 if (GCT_is_loopback (t))
2213 type = ntohs (message->type);
2215 /* Even if tunnel is "being destroyed", send anyway.
2216 * Could be a response to a rekey initiated by remote peer,
2217 * who is trying to create a new channel!
2220 /* Must have a connection, or be looking for one. */
2221 if (NULL == t->connection_head)
2223 LOG (GNUNET_ERROR_TYPE_DEBUG, "%s with no connection\n", GC_m2s (type));
2224 if (CADET_TUNNEL_SEARCHING != t->cstate)
2227 GCT_debug (t, GNUNET_ERROR_TYPE_ERROR);
2228 GCP_debug (t->peer, GNUNET_ERROR_TYPE_ERROR);
2233 msg = (struct GNUNET_CADET_KX *) cbuf;
2234 msg->header.type = htons (GNUNET_MESSAGE_TYPE_CADET_KX);
2235 msg->header.size = htons (sizeof (struct GNUNET_CADET_KX) + size);
2236 c = tunnel_get_connection (t);
2239 if (NULL == t->destroy_task && CADET_TUNNEL_READY == t->cstate)
2242 GCT_debug (t, GNUNET_ERROR_TYPE_ERROR);
2248 case GNUNET_MESSAGE_TYPE_CADET_KX_EPHEMERAL:
2249 case GNUNET_MESSAGE_TYPE_CADET_AX_KX:
2250 GNUNET_assert (NULL == t->ephm_h);
2253 case GNUNET_MESSAGE_TYPE_CADET_KX_PONG:
2254 GNUNET_assert (NULL == t->pong_h);
2259 LOG (GNUNET_ERROR_TYPE_DEBUG, "unkown type %s\n", GC_m2s (type));
2262 memcpy (&msg[1], message, size);
2264 fwd = GCC_is_origin (c, GNUNET_YES);
2266 return GCC_send_prebuilt_message (&msg->header, type, 0, c,
2273 * Send the ephemeral key on a tunnel.
2275 * @param t Tunnel on which to send the key.
2278 send_ephemeral (struct CadetTunnel *t)
2280 LOG (GNUNET_ERROR_TYPE_INFO, "===> EPHM for %s\n", GCT_2s (t));
2281 if (NULL != t->ephm_h)
2283 LOG (GNUNET_ERROR_TYPE_INFO, " already queued\n");
2287 otr_kx_msg.sender_status = htonl (t->estate);
2288 otr_kx_msg.iv = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX);
2289 otr_kx_msg.nonce = t->kx_ctx->challenge;
2290 LOG (GNUNET_ERROR_TYPE_DEBUG, " send nonce c %u\n", otr_kx_msg.nonce);
2291 t_encrypt (t, &otr_kx_msg.nonce, &otr_kx_msg.nonce,
2292 ping_encryption_size(), otr_kx_msg.iv, GNUNET_YES);
2293 LOG (GNUNET_ERROR_TYPE_DEBUG, " send nonce e %u\n", otr_kx_msg.nonce);
2294 t->ephm_h = send_kx (t, &otr_kx_msg.header);
2299 * Send a pong message on a tunnel.
2301 * @param t Tunnel on which to send the pong.
2302 * @param challenge Value sent in the ping that we have to send back.
2305 send_pong (struct CadetTunnel *t, uint32_t challenge)
2307 struct GNUNET_CADET_KX_Pong msg;
2309 LOG (GNUNET_ERROR_TYPE_INFO, "===> PONG for %s\n", GCT_2s (t));
2310 if (NULL != t->pong_h)
2312 LOG (GNUNET_ERROR_TYPE_INFO, " already queued\n");
2315 msg.header.size = htons (sizeof (msg));
2316 msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_KX_PONG);
2317 msg.iv = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX);
2318 msg.nonce = challenge;
2319 LOG (GNUNET_ERROR_TYPE_DEBUG, " sending %u\n", msg.nonce);
2320 t_encrypt (t, &msg.nonce, &msg.nonce,
2321 sizeof (msg.nonce), msg.iv, GNUNET_YES);
2322 LOG (GNUNET_ERROR_TYPE_DEBUG, " e sending %u\n", msg.nonce);
2324 t->pong_h = send_kx (t, &msg.header);
2329 * Initiate a rekey with the remote peer.
2331 * @param cls Closure (tunnel).
2332 * @param tc TaskContext.
2335 rekey_tunnel (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
2337 struct CadetTunnel *t = cls;
2339 t->rekey_task = NULL;
2341 LOG (GNUNET_ERROR_TYPE_INFO, "Re-key Tunnel %s\n", GCT_2s (t));
2342 if (NULL != tc && 0 != (GNUNET_SCHEDULER_REASON_SHUTDOWN & tc->reason))
2345 GNUNET_assert (NULL != t->kx_ctx);
2346 struct GNUNET_TIME_Relative duration;
2348 duration = GNUNET_TIME_absolute_get_duration (t->kx_ctx->rekey_start_time);
2349 LOG (GNUNET_ERROR_TYPE_DEBUG, " kx started %s ago\n",
2350 GNUNET_STRINGS_relative_time_to_string (duration, GNUNET_YES));
2352 // FIXME make duration of old keys configurable
2353 if (duration.rel_value_us >= GNUNET_TIME_UNIT_MINUTES.rel_value_us)
2355 LOG (GNUNET_ERROR_TYPE_DEBUG, " deleting old keys\n");
2356 memset (&t->kx_ctx->d_key_old, 0, sizeof (t->kx_ctx->d_key_old));
2357 memset (&t->kx_ctx->e_key_old, 0, sizeof (t->kx_ctx->e_key_old));
2364 case CADET_TUNNEL_KEY_UNINITIALIZED:
2365 GCT_change_estate (t, CADET_TUNNEL_KEY_SENT);
2368 case CADET_TUNNEL_KEY_SENT:
2371 case CADET_TUNNEL_KEY_OK:
2373 * - state should have changed during rekey_iterator
2374 * - task should have been canceled at pong_handle
2377 GCT_change_estate (t, CADET_TUNNEL_KEY_REKEY);
2380 case CADET_TUNNEL_KEY_PING:
2381 case CADET_TUNNEL_KEY_REKEY:
2385 LOG (GNUNET_ERROR_TYPE_DEBUG, "Unexpected state %u\n", t->estate);
2388 // FIXME exponential backoff
2389 struct GNUNET_TIME_Relative delay;
2391 delay = GNUNET_TIME_relative_divide (rekey_period, 16);
2392 delay = GNUNET_TIME_relative_min (delay, REKEY_WAIT);
2393 LOG (GNUNET_ERROR_TYPE_DEBUG, " next call in %s\n",
2394 GNUNET_STRINGS_relative_time_to_string (delay, GNUNET_YES));
2395 t->rekey_task = GNUNET_SCHEDULER_add_delayed (delay, &rekey_tunnel, t);
2400 * Our ephemeral key has changed, create new session key on all tunnels.
2402 * Each tunnel will start the Key Exchange with a random delay between
2403 * 0 and number_of_tunnels*100 milliseconds, so there are 10 key exchanges
2404 * per second, on average.
2406 * @param cls Closure (size of the hashmap).
2407 * @param key Current public key.
2408 * @param value Value in the hash map (tunnel).
2410 * @return #GNUNET_YES, so we should continue to iterate,
2413 rekey_iterator (void *cls,
2414 const struct GNUNET_PeerIdentity *key,
2417 struct CadetTunnel *t = value;
2418 struct GNUNET_TIME_Relative delay;
2419 long n = (long) cls;
2422 if (NULL != t->rekey_task)
2425 if (GNUNET_YES == GCT_is_loopback (t))
2428 if (CADET_OTR != t->enc_type)
2431 r = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK, (uint32_t) n * 100);
2432 delay = GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MILLISECONDS, r);
2433 t->rekey_task = GNUNET_SCHEDULER_add_delayed (delay, &rekey_tunnel, t);
2434 if (GNUNET_OK == create_kx_ctx (t))
2435 GCT_change_estate (t, CADET_TUNNEL_KEY_REKEY);
2447 * Create a new ephemeral key and key message, schedule next rekeying.
2449 * @param cls Closure (unused).
2450 * @param tc TaskContext.
2453 global_otr_rekey (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
2455 struct GNUNET_TIME_Absolute time;
2460 if (0 != (GNUNET_SCHEDULER_REASON_SHUTDOWN & tc->reason))
2463 GNUNET_free_non_null (otr_ephemeral_key);
2464 otr_ephemeral_key = GNUNET_CRYPTO_ecdhe_key_create ();
2466 time = GNUNET_TIME_absolute_get ();
2467 otr_kx_msg.creation_time = GNUNET_TIME_absolute_hton (time);
2468 time = GNUNET_TIME_absolute_add (time, rekey_period);
2469 time = GNUNET_TIME_absolute_add (time, GNUNET_TIME_UNIT_MINUTES);
2470 otr_kx_msg.expiration_time = GNUNET_TIME_absolute_hton (time);
2471 GNUNET_CRYPTO_ecdhe_key_get_public (otr_ephemeral_key, &otr_kx_msg.ephemeral_key);
2472 LOG (GNUNET_ERROR_TYPE_INFO, "GLOBAL OTR RE-KEY, NEW EPHM: %s\n",
2473 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &otr_kx_msg.ephemeral_key));
2475 GNUNET_assert (GNUNET_OK ==
2476 GNUNET_CRYPTO_eddsa_sign (id_key,
2477 &otr_kx_msg.purpose,
2478 &otr_kx_msg.signature));
2480 n = (long) GNUNET_CONTAINER_multipeermap_size (tunnels);
2481 GNUNET_CONTAINER_multipeermap_iterate (tunnels, &rekey_iterator, (void *) n);
2483 rekey_task = GNUNET_SCHEDULER_add_delayed (rekey_period,
2484 &global_otr_rekey, NULL);
2489 * Called only on shutdown, destroy every tunnel.
2491 * @param cls Closure (unused).
2492 * @param key Current public key.
2493 * @param value Value in the hash map (tunnel).
2495 * @return #GNUNET_YES, so we should continue to iterate,
2498 destroy_iterator (void *cls,
2499 const struct GNUNET_PeerIdentity *key,
2502 struct CadetTunnel *t = value;
2504 LOG (GNUNET_ERROR_TYPE_DEBUG, "GCT_shutdown destroying tunnel at %p\n", t);
2511 * Notify remote peer that we don't know a channel he is talking about,
2512 * probably CHANNEL_DESTROY was missed.
2514 * @param t Tunnel on which to notify.
2515 * @param gid ID of the channel.
2518 send_channel_destroy (struct CadetTunnel *t, unsigned int gid)
2520 struct GNUNET_CADET_ChannelManage msg;
2522 msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_CHANNEL_DESTROY);
2523 msg.header.size = htons (sizeof (msg));
2524 msg.chid = htonl (gid);
2526 LOG (GNUNET_ERROR_TYPE_DEBUG,
2527 "WARNING destroying unknown channel %u on tunnel %s\n",
2529 send_prebuilt_message (&msg.header, t, NULL, GNUNET_YES, NULL, NULL, NULL);
2534 * Demultiplex data per channel and call appropriate channel handler.
2536 * @param t Tunnel on which the data came.
2537 * @param msg Data message.
2538 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
2539 * #GNUNET_YES if message is FWD on the respective channel (loopback)
2540 * #GNUNET_NO if message is BCK on the respective channel (loopback)
2541 * #GNUNET_SYSERR if message on a one-ended channel (remote)
2544 handle_data (struct CadetTunnel *t,
2545 const struct GNUNET_CADET_Data *msg,
2548 struct CadetChannel *ch;
2554 size = ntohs (msg->header.size);
2556 sizeof (struct GNUNET_CADET_Data) +
2557 sizeof (struct GNUNET_MessageHeader))
2562 type = ntohs (msg[1].header.type);
2563 LOG (GNUNET_ERROR_TYPE_DEBUG, " payload of type %s\n", GC_m2s (type));
2564 sprintf (buf, "# received payload of type %hu", type);
2565 GNUNET_STATISTICS_update (stats, buf, 1, GNUNET_NO);
2569 ch = GCT_get_channel (t, ntohl (msg->chid));
2572 GNUNET_STATISTICS_update (stats, "# data on unknown channel",
2574 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel 0x%X unknown\n",
2576 send_channel_destroy (t, ntohl (msg->chid));
2580 GCCH_handle_data (ch, msg, fwd);
2585 * Demultiplex data ACKs per channel and update appropriate channel buffer info.
2587 * @param t Tunnel on which the DATA ACK came.
2588 * @param msg DATA ACK message.
2589 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
2590 * #GNUNET_YES if message is FWD on the respective channel (loopback)
2591 * #GNUNET_NO if message is BCK on the respective channel (loopback)
2592 * #GNUNET_SYSERR if message on a one-ended channel (remote)
2595 handle_data_ack (struct CadetTunnel *t,
2596 const struct GNUNET_CADET_DataACK *msg,
2599 struct CadetChannel *ch;
2603 size = ntohs (msg->header.size);
2604 if (size != sizeof (struct GNUNET_CADET_DataACK))
2611 ch = GCT_get_channel (t, ntohl (msg->chid));
2614 GNUNET_STATISTICS_update (stats, "# data ack on unknown channel",
2616 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel %u unknown\n",
2621 GCCH_handle_data_ack (ch, msg, fwd);
2626 * Handle channel create.
2628 * @param t Tunnel on which the data came.
2629 * @param msg Data message.
2632 handle_ch_create (struct CadetTunnel *t,
2633 const struct GNUNET_CADET_ChannelCreate *msg)
2635 struct CadetChannel *ch;
2639 size = ntohs (msg->header.size);
2640 if (size != sizeof (struct GNUNET_CADET_ChannelCreate))
2647 ch = GCT_get_channel (t, ntohl (msg->chid));
2648 if (NULL != ch && ! GCT_is_loopback (t))
2650 /* Probably a retransmission, safe to ignore */
2651 LOG (GNUNET_ERROR_TYPE_DEBUG, " already exists...\n");
2653 ch = GCCH_handle_create (t, msg);
2655 GCT_add_channel (t, ch);
2661 * Handle channel NACK: check correctness and call channel handler for NACKs.
2663 * @param t Tunnel on which the NACK came.
2664 * @param msg NACK message.
2667 handle_ch_nack (struct CadetTunnel *t,
2668 const struct GNUNET_CADET_ChannelManage *msg)
2670 struct CadetChannel *ch;
2674 size = ntohs (msg->header.size);
2675 if (size != sizeof (struct GNUNET_CADET_ChannelManage))
2682 ch = GCT_get_channel (t, ntohl (msg->chid));
2685 GNUNET_STATISTICS_update (stats, "# channel NACK on unknown channel",
2687 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel %u unknown\n",
2692 GCCH_handle_nack (ch);
2697 * Handle a CHANNEL ACK (SYNACK/ACK).
2699 * @param t Tunnel on which the CHANNEL ACK came.
2700 * @param msg CHANNEL ACK message.
2701 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
2702 * #GNUNET_YES if message is FWD on the respective channel (loopback)
2703 * #GNUNET_NO if message is BCK on the respective channel (loopback)
2704 * #GNUNET_SYSERR if message on a one-ended channel (remote)
2707 handle_ch_ack (struct CadetTunnel *t,
2708 const struct GNUNET_CADET_ChannelManage *msg,
2711 struct CadetChannel *ch;
2715 size = ntohs (msg->header.size);
2716 if (size != sizeof (struct GNUNET_CADET_ChannelManage))
2723 ch = GCT_get_channel (t, ntohl (msg->chid));
2726 GNUNET_STATISTICS_update (stats, "# channel ack on unknown channel",
2728 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel %u unknown\n",
2733 GCCH_handle_ack (ch, msg, fwd);
2738 * Handle a channel destruction message.
2740 * @param t Tunnel on which the message came.
2741 * @param msg Channel destroy message.
2742 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
2743 * #GNUNET_YES if message is FWD on the respective channel (loopback)
2744 * #GNUNET_NO if message is BCK on the respective channel (loopback)
2745 * #GNUNET_SYSERR if message on a one-ended channel (remote)
2748 handle_ch_destroy (struct CadetTunnel *t,
2749 const struct GNUNET_CADET_ChannelManage *msg,
2752 struct CadetChannel *ch;
2756 size = ntohs (msg->header.size);
2757 if (size != sizeof (struct GNUNET_CADET_ChannelManage))
2764 ch = GCT_get_channel (t, ntohl (msg->chid));
2767 /* Probably a retransmission, safe to ignore */
2771 GCCH_handle_destroy (ch, msg, fwd);
2776 * Free Axolotl data.
2781 destroy_ax (struct CadetTunnel *t)
2786 GNUNET_free_non_null (t->ax->DHRs);
2787 GNUNET_free_non_null (t->ax->kx_0);
2788 while (NULL != t->ax->skipped_head)
2789 delete_skipped_key (t, t->ax->skipped_head);
2790 GNUNET_assert (0 == t->ax->skipped);
2792 GNUNET_free (t->ax);
2795 if (NULL != t->rekey_task)
2797 GNUNET_SCHEDULER_cancel (t->rekey_task);
2798 t->rekey_task = NULL;
2800 if (NULL != t->ephm_h)
2802 GCC_cancel (t->ephm_h);
2809 * The peer's ephemeral key has changed: update the symmetrical keys.
2811 * @param t Tunnel this message came on.
2812 * @param msg Key eXchange message.
2815 handle_ephemeral (struct CadetTunnel *t,
2816 const struct GNUNET_CADET_KX_Ephemeral *msg)
2818 LOG (GNUNET_ERROR_TYPE_INFO, "<=== EPHM for %s\n", GCT_2s (t));
2820 /* Some old versions are still around, don't log as error. */
2821 if (GNUNET_OK != check_ephemeral (t, msg))
2824 /* If we get a proper OTR-style ephemeral, fallback to old crypto. */
2828 t->enc_type = CADET_OTR;
2829 if (NULL != t->rekey_task)
2830 GNUNET_SCHEDULER_cancel (t->rekey_task);
2831 if (GNUNET_OK != create_kx_ctx (t))
2837 rekey_tunnel (t, NULL);
2838 GNUNET_STATISTICS_update (stats, "# otr-downgrades", -1, GNUNET_NO);
2842 * If the key is different from what we know, derive the new E/D keys.
2843 * Else destroy the rekey ctx (duplicate EPHM after successful KX).
2845 if (0 != memcmp (&t->peers_ephemeral_key, &msg->ephemeral_key,
2846 sizeof (msg->ephemeral_key)))
2848 #if DUMP_KEYS_TO_STDERR
2849 LOG (GNUNET_ERROR_TYPE_INFO, "OLD: %s\n",
2850 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &t->peers_ephemeral_key));
2851 LOG (GNUNET_ERROR_TYPE_INFO, "NEW: %s\n",
2852 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &msg->ephemeral_key));
2854 t->peers_ephemeral_key = msg->ephemeral_key;
2856 if (GNUNET_OK != create_kx_ctx (t))
2863 if (CADET_TUNNEL_KEY_OK == t->estate)
2865 GCT_change_estate (t, CADET_TUNNEL_KEY_REKEY);
2867 if (NULL != t->rekey_task)
2868 GNUNET_SCHEDULER_cancel (t->rekey_task);
2869 t->rekey_task = GNUNET_SCHEDULER_add_now (rekey_tunnel, t);
2871 if (CADET_TUNNEL_KEY_SENT == t->estate)
2873 LOG (GNUNET_ERROR_TYPE_DEBUG, " our key was sent, sending challenge\n");
2875 GCT_change_estate (t, CADET_TUNNEL_KEY_PING);
2878 if (CADET_TUNNEL_KEY_UNINITIALIZED != ntohl(msg->sender_status))
2882 LOG (GNUNET_ERROR_TYPE_DEBUG, " recv nonce e %u\n", msg->nonce);
2883 t_decrypt (t, &nonce, &msg->nonce, ping_encryption_size (), msg->iv);
2884 LOG (GNUNET_ERROR_TYPE_DEBUG, " recv nonce c %u\n", nonce);
2885 send_pong (t, nonce);
2891 * Peer has answer to our challenge.
2892 * If answer is successful, consider the key exchange finished and clean
2893 * up all related state.
2895 * @param t Tunnel this message came on.
2896 * @param msg Key eXchange Pong message.
2899 handle_pong (struct CadetTunnel *t,
2900 const struct GNUNET_CADET_KX_Pong *msg)
2904 LOG (GNUNET_ERROR_TYPE_INFO, "<=== PONG for %s\n", GCT_2s (t));
2905 if (NULL == t->rekey_task)
2907 GNUNET_STATISTICS_update (stats, "# duplicate PONG messages", 1, GNUNET_NO);
2910 if (NULL == t->kx_ctx)
2912 GNUNET_STATISTICS_update (stats, "# stray PONG messages", 1, GNUNET_NO);
2916 t_decrypt (t, &challenge, &msg->nonce, sizeof (uint32_t), msg->iv);
2917 if (challenge != t->kx_ctx->challenge)
2919 LOG (GNUNET_ERROR_TYPE_WARNING, "Wrong PONG challenge on %s\n", GCT_2s (t));
2920 LOG (GNUNET_ERROR_TYPE_DEBUG, "PONG: %u (e: %u). Expected: %u.\n",
2921 challenge, msg->nonce, t->kx_ctx->challenge);
2925 GNUNET_SCHEDULER_cancel (t->rekey_task);
2926 t->rekey_task = NULL;
2928 /* Don't free the old keys right away, but after a delay.
2929 * Rationale: the KX could have happened over a very fast connection,
2930 * with payload traffic still signed with the old key stuck in a slower
2932 * Don't keep the keys longer than 1/4 the rekey period, and no longer than
2936 GCT_change_estate (t, CADET_TUNNEL_KEY_OK);
2941 * Handle Axolotl handshake.
2943 * @param t Tunnel this message came on.
2944 * @param msg Key eXchange Pong message.
2947 handle_kx_ax (struct CadetTunnel *t, const struct GNUNET_CADET_AX_KX *msg)
2949 struct CadetTunnelAxolotl *ax;
2950 struct GNUNET_HashCode key_material[3];
2951 struct GNUNET_CRYPTO_SymmetricSessionKey keys[5];
2952 const char salt[] = "CADET Axolotl salt";
2953 const struct GNUNET_PeerIdentity *pid;
2956 LOG (GNUNET_ERROR_TYPE_INFO, "<=== AX_KX on %s\n", GCT_2s (t));
2960 /* Something is wrong if ax is NULL. Whose fault it is? */
2961 GNUNET_break_op (CADET_OTR == t->enc_type);
2962 GNUNET_break (CADET_Axolotl == t->enc_type);
2967 pid = GCT_get_destination (t);
2968 if (0 > GNUNET_CRYPTO_cmp_peer_identity (&my_full_id, pid))
2969 am_I_alice = GNUNET_YES;
2970 else if (0 < GNUNET_CRYPTO_cmp_peer_identity (&my_full_id, pid))
2971 am_I_alice = GNUNET_NO;
2974 GNUNET_break_op (0);
2978 if (0 != (GNUNET_CADET_AX_KX_FLAG_FORCE_REPLY & ntohl (msg->flags)))
2980 if (NULL != t->rekey_task)
2982 GNUNET_SCHEDULER_cancel (t->rekey_task);
2983 t->rekey_task = NULL;
2985 GCT_send_ax_kx (t, GNUNET_NO);
2988 if (0 == memcmp (&ax->DHRr, &msg->ratchet_key, sizeof(msg->ratchet_key)))
2990 LOG (GNUNET_ERROR_TYPE_INFO, " known ratchet key, exit\n");
2994 LOG (GNUNET_ERROR_TYPE_INFO, " is Alice? %s\n", am_I_alice ? "YES" : "NO");
2996 ax->DHRr = msg->ratchet_key;
2999 if (GNUNET_YES == am_I_alice)
3001 GNUNET_CRYPTO_eddsa_ecdh (id_key, /* A */
3002 &msg->ephemeral_key, /* B0 */
3007 GNUNET_CRYPTO_ecdh_eddsa (ax->kx_0, /* B0 */
3008 &pid->public_key, /* A */
3013 if (GNUNET_YES == am_I_alice)
3015 GNUNET_CRYPTO_ecdh_eddsa (ax->kx_0, /* A0 */
3016 &pid->public_key, /* B */
3021 GNUNET_CRYPTO_eddsa_ecdh (id_key, /* A */
3022 &msg->ephemeral_key, /* B0 */
3029 /* (This is the triple-DH, we could probably safely skip this,
3030 as A0/B0 are already in the key material.) */
3031 GNUNET_CRYPTO_ecc_ecdh (ax->kx_0, /* A0 or B0 */
3032 &msg->ephemeral_key, /* B0 or A0 */
3035 #if DUMP_KEYS_TO_STDERR
3038 for (i = 0; i < 3; i++)
3039 LOG (GNUNET_ERROR_TYPE_INFO, "km[%u]: %s\n",
3040 i, GNUNET_h2s (&key_material[i]));
3045 GNUNET_CRYPTO_kdf (keys, sizeof (keys),
3046 salt, sizeof (salt),
3047 &key_material, sizeof (key_material), NULL);
3049 if (0 == memcmp (&ax->RK, &keys[0], sizeof(ax->RK)))
3051 LOG (GNUNET_ERROR_TYPE_INFO, " known handshake key, exit\n");
3055 if (GNUNET_YES == am_I_alice)
3061 ax->ratchet_flag = GNUNET_YES;
3069 ax->ratchet_flag = GNUNET_NO;
3070 ax->ratchet_allowed = GNUNET_NO;
3071 ax->ratchet_counter = 0;
3072 ax->ratchet_expiration =
3073 GNUNET_TIME_absolute_add (GNUNET_TIME_absolute_get(), ratchet_time);
3078 GCT_change_estate (t, CADET_TUNNEL_KEY_PING);
3079 send_queued_data (t);
3084 * Demultiplex by message type and call appropriate handler for a message
3085 * towards a channel of a local tunnel.
3087 * @param t Tunnel this message came on.
3088 * @param msgh Message header.
3089 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
3090 * #GNUNET_YES if message is FWD on the respective channel (loopback)
3091 * #GNUNET_NO if message is BCK on the respective channel (loopback)
3092 * #GNUNET_SYSERR if message on a one-ended channel (remote)
3095 handle_decrypted (struct CadetTunnel *t,
3096 const struct GNUNET_MessageHeader *msgh,
3102 type = ntohs (msgh->type);
3103 LOG (GNUNET_ERROR_TYPE_INFO, "<=== %s on %s\n", GC_m2s (type), GCT_2s (t));
3104 sprintf (buf, "# received encrypted of type %hu (%s)", type, GC_m2s (type));
3105 GNUNET_STATISTICS_update (stats, buf, 1, GNUNET_NO);
3109 case GNUNET_MESSAGE_TYPE_CADET_KEEPALIVE:
3110 /* Do nothing, connection aleady got updated. */
3111 GNUNET_STATISTICS_update (stats, "# keepalives received", 1, GNUNET_NO);
3114 case GNUNET_MESSAGE_TYPE_CADET_DATA:
3115 /* Don't send hop ACK, wait for client to ACK */
3116 handle_data (t, (struct GNUNET_CADET_Data *) msgh, fwd);
3119 case GNUNET_MESSAGE_TYPE_CADET_DATA_ACK:
3120 handle_data_ack (t, (struct GNUNET_CADET_DataACK *) msgh, fwd);
3123 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_CREATE:
3124 handle_ch_create (t, (struct GNUNET_CADET_ChannelCreate *) msgh);
3127 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_NACK:
3128 handle_ch_nack (t, (struct GNUNET_CADET_ChannelManage *) msgh);
3131 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_ACK:
3132 handle_ch_ack (t, (struct GNUNET_CADET_ChannelManage *) msgh, fwd);
3135 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_DESTROY:
3136 handle_ch_destroy (t, (struct GNUNET_CADET_ChannelManage *) msgh, fwd);
3140 GNUNET_break_op (0);
3141 LOG (GNUNET_ERROR_TYPE_WARNING,
3142 "end-to-end message not known (%u)\n",
3143 ntohs (msgh->type));
3144 GCT_debug (t, GNUNET_ERROR_TYPE_WARNING);
3149 /******************************************************************************/
3150 /******************************** API ***********************************/
3151 /******************************************************************************/
3153 * Decrypt old format and demultiplex by message type. Call appropriate handler
3154 * for a message towards a channel of a local tunnel.
3156 * @param t Tunnel this message came on.
3157 * @param msg Message header.
3160 GCT_handle_encrypted (struct CadetTunnel *t,
3161 const struct GNUNET_MessageHeader *msg)
3163 uint16_t size = ntohs (msg->size);
3167 const struct GNUNET_MessageHeader *msgh;
3170 type = ntohs (msg->type);
3173 case GNUNET_MESSAGE_TYPE_CADET_ENCRYPTED:
3175 const struct GNUNET_CADET_Encrypted *emsg;
3176 size_t payload_size;
3178 GNUNET_STATISTICS_update (stats, "# received OTR", 1, GNUNET_NO);
3179 emsg = (const struct GNUNET_CADET_Encrypted *) msg;
3180 payload_size = size - sizeof (struct GNUNET_CADET_Encrypted);
3181 decrypted_size = t_decrypt_and_validate (t, cbuf, &emsg[1], payload_size,
3182 emsg->iv, &emsg->hmac);
3185 case GNUNET_MESSAGE_TYPE_CADET_AX:
3187 const struct GNUNET_CADET_AX *emsg;
3189 GNUNET_STATISTICS_update (stats, "# received Axolotl", 1, GNUNET_NO);
3190 emsg = (const struct GNUNET_CADET_AX *) msg;
3191 decrypted_size = t_ax_decrypt_and_validate (t, cbuf, emsg, size);
3195 GNUNET_break_op (0);
3199 if (-1 == decrypted_size)
3201 GNUNET_break_op (0);
3202 GNUNET_STATISTICS_update (stats, "# unable to decrypt", 1, GNUNET_NO);
3203 LOG (GNUNET_ERROR_TYPE_WARNING, "Wrong crypto on tunnel %s\n", GCT_2s (t));
3204 GCT_debug (t, GNUNET_ERROR_TYPE_WARNING);
3207 GCT_change_estate (t, CADET_TUNNEL_KEY_OK);
3209 /* FIXME: this is bad, as the structs returned from
3210 this loop may be unaligned, see util's MST for
3211 how to do this right. */
3213 while (off + sizeof (struct GNUNET_MessageHeader) <= decrypted_size)
3217 msgh = (const struct GNUNET_MessageHeader *) &cbuf[off];
3218 msize = ntohs (msgh->size);
3219 if (msize < sizeof (struct GNUNET_MessageHeader))
3221 GNUNET_break_op (0);
3224 if (off + msize < decrypted_size)
3226 GNUNET_break_op (0);
3229 handle_decrypted (t, msgh, GNUNET_SYSERR);
3236 * Demultiplex an encapsulated KX message by message type.
3238 * @param t Tunnel on which the message came.
3239 * @param message Payload of KX message.
3242 GCT_handle_kx (struct CadetTunnel *t,
3243 const struct GNUNET_MessageHeader *message)
3248 type = ntohs (message->type);
3249 LOG (GNUNET_ERROR_TYPE_DEBUG, "kx message received: %s\n", GC_m2s (type));
3250 sprintf (buf, "# received KX of type %hu (%s)", type, GC_m2s (type));
3251 GNUNET_STATISTICS_update (stats, buf, 1, GNUNET_NO);
3254 case GNUNET_MESSAGE_TYPE_CADET_KX_EPHEMERAL:
3255 handle_ephemeral (t, (const struct GNUNET_CADET_KX_Ephemeral *) message);
3258 case GNUNET_MESSAGE_TYPE_CADET_KX_PONG:
3259 handle_pong (t, (const struct GNUNET_CADET_KX_Pong *) message);
3262 case GNUNET_MESSAGE_TYPE_CADET_AX_KX:
3263 handle_kx_ax (t, (const struct GNUNET_CADET_AX_KX *) message);
3267 GNUNET_break_op (0);
3268 LOG (GNUNET_ERROR_TYPE_WARNING, "kx message %s unknown\n", GC_m2s (type));
3273 * Initialize the tunnel subsystem.
3275 * @param c Configuration handle.
3276 * @param key ECC private key, to derive all other keys and do crypto.
3279 GCT_init (const struct GNUNET_CONFIGURATION_Handle *c,
3280 const struct GNUNET_CRYPTO_EddsaPrivateKey *key)
3282 int expected_overhead;
3284 LOG (GNUNET_ERROR_TYPE_DEBUG, "init\n");
3286 expected_overhead = 0;
3287 expected_overhead += sizeof (struct GNUNET_CADET_Encrypted);
3288 expected_overhead += sizeof (struct GNUNET_CADET_Data);
3289 expected_overhead += sizeof (struct GNUNET_CADET_ACK);
3290 GNUNET_assert (GNUNET_CONSTANTS_CADET_P2P_OVERHEAD == expected_overhead);
3293 GNUNET_CONFIGURATION_get_value_number (c, "CADET", "DEFAULT_TTL",
3296 GNUNET_log_config_invalid (GNUNET_ERROR_TYPE_DEBUG,
3297 "CADET", "DEFAULT_TTL", "USING DEFAULT");
3301 GNUNET_CONFIGURATION_get_value_time (c, "CADET", "REKEY_PERIOD",
3304 rekey_period = GNUNET_TIME_UNIT_DAYS;
3307 GNUNET_CONFIGURATION_get_value_number (c, "CADET", "RATCHET_MESSAGES",
3310 GNUNET_log_config_invalid (GNUNET_ERROR_TYPE_WARNING,
3311 "CADET", "RATCHET_MESSAGES", "USING DEFAULT");
3312 ratchet_messages = 64;
3315 GNUNET_CONFIGURATION_get_value_time (c, "CADET", "RATCHET_TIME",
3318 GNUNET_log_config_invalid (GNUNET_ERROR_TYPE_WARNING,
3319 "CADET", "RATCHET_TIME", "USING DEFAULT");
3320 ratchet_time = GNUNET_TIME_UNIT_HOURS;
3326 otr_kx_msg.header.size = htons (sizeof (otr_kx_msg));
3327 otr_kx_msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_KX_EPHEMERAL);
3328 otr_kx_msg.purpose.purpose = htonl (GNUNET_SIGNATURE_PURPOSE_CADET_KX);
3329 otr_kx_msg.purpose.size = htonl (ephemeral_purpose_size ());
3330 otr_kx_msg.origin_identity = my_full_id;
3331 rekey_task = GNUNET_SCHEDULER_add_now (&global_otr_rekey, NULL);
3332 tunnels = GNUNET_CONTAINER_multipeermap_create (128, GNUNET_YES);
3337 * Shut down the tunnel subsystem.
3342 LOG (GNUNET_ERROR_TYPE_DEBUG, "Shutting down tunnels\n");
3343 if (NULL != rekey_task)
3345 GNUNET_SCHEDULER_cancel (rekey_task);
3348 GNUNET_CONTAINER_multipeermap_iterate (tunnels, &destroy_iterator, NULL);
3349 GNUNET_CONTAINER_multipeermap_destroy (tunnels);
3356 * @param destination Peer this tunnel is towards.
3358 struct CadetTunnel *
3359 GCT_new (struct CadetPeer *destination)
3361 struct CadetTunnel *t;
3363 t = GNUNET_new (struct CadetTunnel);
3365 t->peer = destination;
3368 GNUNET_CONTAINER_multipeermap_put (tunnels, GCP_get_id (destination), t,
3369 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_FAST))
3375 t->ax = GNUNET_new (struct CadetTunnelAxolotl);
3377 t->ax->kx_0 = GNUNET_CRYPTO_ecdhe_key_create ();
3383 * Change the tunnel's connection state.
3385 * @param t Tunnel whose connection state to change.
3386 * @param cstate New connection state.
3389 GCT_change_cstate (struct CadetTunnel* t, enum CadetTunnelCState cstate)
3393 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel %s cstate %s => %s\n",
3394 GCP_2s (t->peer), cstate2s (t->cstate), cstate2s (cstate));
3395 if (myid != GCP_get_short_id (t->peer) &&
3396 CADET_TUNNEL_READY != t->cstate &&
3397 CADET_TUNNEL_READY == cstate)
3400 if (CADET_TUNNEL_KEY_OK == t->estate)
3402 LOG (GNUNET_ERROR_TYPE_DEBUG, " cstate triggered send queued data\n");
3403 send_queued_data (t);
3405 else if (CADET_TUNNEL_KEY_UNINITIALIZED == t->estate)
3407 LOG (GNUNET_ERROR_TYPE_DEBUG, " cstate triggered kx\n");
3408 GCT_send_ax_kx (t, GNUNET_NO);
3412 LOG (GNUNET_ERROR_TYPE_DEBUG, "estate %s\n", estate2s (t->estate));
3417 if (CADET_TUNNEL_READY == cstate
3418 && CONNECTIONS_PER_TUNNEL <= GCT_count_connections (t))
3420 LOG (GNUNET_ERROR_TYPE_DEBUG, " cstate triggered stop dht\n");
3421 GCP_stop_search (t->peer);
3427 * Change the tunnel encryption state.
3429 * If the encryption state changes to OK, stop the rekey task.
3431 * @param t Tunnel whose encryption state to change, or NULL.
3432 * @param state New encryption state.
3435 GCT_change_estate (struct CadetTunnel* t, enum CadetTunnelEState state)
3437 enum CadetTunnelEState old;
3444 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel %s estate was %s\n",
3445 GCP_2s (t->peer), estate2s (old));
3446 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel %s estate is now %s\n",
3447 GCP_2s (t->peer), estate2s (t->estate));
3449 if (CADET_TUNNEL_KEY_OK != old && CADET_TUNNEL_KEY_OK == t->estate)
3451 if (NULL != t->rekey_task)
3453 GNUNET_SCHEDULER_cancel (t->rekey_task);
3454 t->rekey_task = NULL;
3456 /* Send queued data if tunnel is not loopback */
3457 if (myid != GCP_get_short_id (t->peer))
3458 send_queued_data (t);
3464 * @brief Check if tunnel has too many connections, and remove one if necessary.
3466 * Currently this means the newest connection, unless it is a direct one.
3467 * Implemented as a task to avoid freeing a connection that is in the middle
3468 * of being created/processed.
3470 * @param cls Closure (Tunnel to check).
3471 * @param tc Task context.
3474 trim_connections (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
3476 struct CadetTunnel *t = cls;
3478 t->trim_connections_task = NULL;
3480 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
3483 if (GCT_count_connections (t) > 2 * CONNECTIONS_PER_TUNNEL)
3485 struct CadetTConnection *iter;
3486 struct CadetTConnection *c;
3488 for (c = iter = t->connection_head; NULL != iter; iter = iter->next)
3490 if ((iter->created.abs_value_us > c->created.abs_value_us)
3491 && GNUNET_NO == GCC_is_direct (iter->c))
3498 LOG (GNUNET_ERROR_TYPE_DEBUG, "Too many connections on tunnel %s\n",
3500 LOG (GNUNET_ERROR_TYPE_DEBUG, "Destroying connection %s\n",
3513 * Add a connection to a tunnel.
3516 * @param c Connection.
3519 GCT_add_connection (struct CadetTunnel *t, struct CadetConnection *c)
3521 struct CadetTConnection *aux;
3523 GNUNET_assert (NULL != c);
3525 LOG (GNUNET_ERROR_TYPE_DEBUG, "add connection %s\n", GCC_2s (c));
3526 LOG (GNUNET_ERROR_TYPE_DEBUG, " to tunnel %s\n", GCT_2s (t));
3527 for (aux = t->connection_head; aux != NULL; aux = aux->next)
3531 aux = GNUNET_new (struct CadetTConnection);
3533 aux->created = GNUNET_TIME_absolute_get ();
3535 GNUNET_CONTAINER_DLL_insert (t->connection_head, t->connection_tail, aux);
3537 if (CADET_TUNNEL_SEARCHING == t->cstate)
3538 GCT_change_cstate (t, CADET_TUNNEL_WAITING);
3540 if (NULL != t->trim_connections_task)
3541 t->trim_connections_task = GNUNET_SCHEDULER_add_now (&trim_connections, t);
3546 * Remove a connection from a tunnel.
3549 * @param c Connection.
3552 GCT_remove_connection (struct CadetTunnel *t,
3553 struct CadetConnection *c)
3555 struct CadetTConnection *aux;
3556 struct CadetTConnection *next;
3559 LOG (GNUNET_ERROR_TYPE_DEBUG, "Removing connection %s from tunnel %s\n",
3560 GCC_2s (c), GCT_2s (t));
3561 for (aux = t->connection_head; aux != NULL; aux = next)
3566 GNUNET_CONTAINER_DLL_remove (t->connection_head, t->connection_tail, aux);
3571 conns = GCT_count_connections (t);
3573 && NULL == t->destroy_task
3574 && CADET_TUNNEL_SHUTDOWN != t->cstate
3575 && GNUNET_NO == shutting_down)
3577 if (0 == GCT_count_any_connections (t))
3578 GCT_change_cstate (t, CADET_TUNNEL_SEARCHING);
3580 GCT_change_cstate (t, CADET_TUNNEL_WAITING);
3583 /* Start new connections if needed */
3584 if (CONNECTIONS_PER_TUNNEL > conns
3585 && CADET_TUNNEL_SHUTDOWN != t->cstate
3586 && GNUNET_NO == shutting_down)
3588 LOG (GNUNET_ERROR_TYPE_DEBUG, " too few connections, getting new ones\n");
3589 GCP_connect (t->peer); /* Will change cstate to WAITING when possible */
3593 /* If not marked as ready, no change is needed */
3594 if (CADET_TUNNEL_READY != t->cstate)
3597 /* Check if any connection is ready to maintain cstate */
3598 for (aux = t->connection_head; aux != NULL; aux = aux->next)
3599 if (CADET_CONNECTION_READY == GCC_get_state (aux->c))
3605 * Add a channel to a tunnel.
3608 * @param ch Channel.
3611 GCT_add_channel (struct CadetTunnel *t, struct CadetChannel *ch)
3613 struct CadetTChannel *aux;
3615 GNUNET_assert (NULL != ch);
3617 LOG (GNUNET_ERROR_TYPE_DEBUG, "Adding channel %p to tunnel %p\n", ch, t);
3619 for (aux = t->channel_head; aux != NULL; aux = aux->next)
3621 LOG (GNUNET_ERROR_TYPE_DEBUG, " already there %p\n", aux->ch);
3626 aux = GNUNET_new (struct CadetTChannel);
3628 LOG (GNUNET_ERROR_TYPE_DEBUG, " adding %p to %p\n", aux, t->channel_head);
3629 GNUNET_CONTAINER_DLL_insert_tail (t->channel_head, t->channel_tail, aux);
3631 if (NULL != t->destroy_task)
3633 GNUNET_SCHEDULER_cancel (t->destroy_task);
3634 t->destroy_task = NULL;
3635 LOG (GNUNET_ERROR_TYPE_DEBUG, " undo destroy!\n");
3641 * Remove a channel from a tunnel.
3644 * @param ch Channel.
3647 GCT_remove_channel (struct CadetTunnel *t, struct CadetChannel *ch)
3649 struct CadetTChannel *aux;
3651 LOG (GNUNET_ERROR_TYPE_DEBUG, "Removing channel %p from tunnel %p\n", ch, t);
3652 for (aux = t->channel_head; aux != NULL; aux = aux->next)
3656 LOG (GNUNET_ERROR_TYPE_DEBUG, " found! %s\n", GCCH_2s (ch));
3657 GNUNET_CONTAINER_DLL_remove (t->channel_head, t->channel_tail, aux);
3666 * Search for a channel by global ID.
3668 * @param t Tunnel containing the channel.
3669 * @param chid Public channel number.
3671 * @return channel handler, NULL if doesn't exist
3673 struct CadetChannel *
3674 GCT_get_channel (struct CadetTunnel *t, CADET_ChannelNumber chid)
3676 struct CadetTChannel *iter;
3681 for (iter = t->channel_head; NULL != iter; iter = iter->next)
3683 if (GCCH_get_id (iter->ch) == chid)
3687 return NULL == iter ? NULL : iter->ch;
3692 * @brief Destroy a tunnel and free all resources.
3694 * Should only be called a while after the tunnel has been marked as destroyed,
3695 * in case there is a new channel added to the same peer shortly after marking
3696 * the tunnel. This way we avoid a new public key handshake.
3698 * @param cls Closure (tunnel to destroy).
3699 * @param tc Task context.
3702 delayed_destroy (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
3704 struct CadetTunnel *t = cls;
3705 struct CadetTConnection *iter;
3707 LOG (GNUNET_ERROR_TYPE_DEBUG, "delayed destroying tunnel %p\n", t);
3708 if (0 != (GNUNET_SCHEDULER_REASON_SHUTDOWN & tc->reason))
3710 LOG (GNUNET_ERROR_TYPE_WARNING,
3711 "Not destroying tunnel, due to shutdown. "
3712 "Tunnel at %p should have been freed by GCT_shutdown\n", t);
3715 t->destroy_task = NULL;
3716 t->cstate = CADET_TUNNEL_SHUTDOWN;
3718 for (iter = t->connection_head; NULL != iter; iter = iter->next)
3720 GCC_send_destroy (iter->c);
3727 * Tunnel is empty: destroy it.
3729 * Notifies all connections about the destruction.
3731 * @param t Tunnel to destroy.
3734 GCT_destroy_empty (struct CadetTunnel *t)
3736 if (GNUNET_YES == shutting_down)
3737 return; /* Will be destroyed immediately anyway */
3739 if (NULL != t->destroy_task)
3741 LOG (GNUNET_ERROR_TYPE_WARNING,
3742 "Tunnel %s is already scheduled for destruction. Tunnel debug dump:\n",
3744 GCT_debug (t, GNUNET_ERROR_TYPE_WARNING);
3746 /* should never happen, tunnel can only become empty once, and the
3747 * task identifier should be NO_TASK (cleaned when the tunnel was created
3748 * or became un-empty)
3753 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel %s empty: scheduling destruction\n",
3756 // FIXME make delay a config option
3757 t->destroy_task = GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_MINUTES,
3758 &delayed_destroy, t);
3759 LOG (GNUNET_ERROR_TYPE_DEBUG, "Scheduled destroy of %p as %p\n",
3760 t, t->destroy_task);
3765 * Destroy tunnel if empty (no more channels).
3767 * @param t Tunnel to destroy if empty.
3770 GCT_destroy_if_empty (struct CadetTunnel *t)
3772 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel %s destroy if empty\n", GCT_2s (t));
3773 if (0 < GCT_count_channels (t))
3776 GCT_destroy_empty (t);
3781 * Destroy the tunnel.
3783 * This function does not generate any warning traffic to clients or peers.
3786 * Cancel messages belonging to this tunnel queued to neighbors.
3787 * Free any allocated resources linked to the tunnel.
3789 * @param t The tunnel to destroy.
3792 GCT_destroy (struct CadetTunnel *t)
3794 struct CadetTConnection *iter_c;
3795 struct CadetTConnection *next_c;
3796 struct CadetTChannel *iter_ch;
3797 struct CadetTChannel *next_ch;
3798 unsigned int keepalives_queued;
3803 LOG (GNUNET_ERROR_TYPE_DEBUG, "destroying tunnel %s\n", GCP_2s (t->peer));
3805 GNUNET_break (GNUNET_YES ==
3806 GNUNET_CONTAINER_multipeermap_remove (tunnels,
3807 GCP_get_id (t->peer), t));
3809 for (iter_c = t->connection_head; NULL != iter_c; iter_c = next_c)
3811 next_c = iter_c->next;
3812 GCC_destroy (iter_c->c);
3814 for (iter_ch = t->channel_head; NULL != iter_ch; iter_ch = next_ch)
3816 next_ch = iter_ch->next;
3817 GCCH_destroy (iter_ch->ch);
3818 /* Should only happen on shutdown, but it's ok. */
3820 keepalives_queued = 0;
3821 while (NULL != t->tq_head)
3823 /* Should have been cleaned by destuction of channel. */
3824 struct GNUNET_MessageHeader *mh;
3827 mh = (struct GNUNET_MessageHeader *) &t->tq_head[1];
3828 type = ntohs (mh->type);
3829 if (0 == keepalives_queued && GNUNET_MESSAGE_TYPE_CADET_KEEPALIVE == type)
3831 keepalives_queued = 1;
3832 LOG (GNUNET_ERROR_TYPE_DEBUG,
3833 "one keepalive left behind on tunnel shutdown\n");
3835 else if (GNUNET_MESSAGE_TYPE_CADET_CHANNEL_DESTROY == type)
3837 LOG (GNUNET_ERROR_TYPE_WARNING,
3838 "tunnel destroyed before a CHANNEL_DESTROY was sent to peer\n");
3843 LOG (GNUNET_ERROR_TYPE_ERROR,
3844 "message left behind on tunnel shutdown: %s\n",
3847 unqueue_data (t->tq_head);
3851 if (NULL != t->destroy_task)
3853 LOG (GNUNET_ERROR_TYPE_DEBUG, "cancelling dest: %p\n", t->destroy_task);
3854 GNUNET_SCHEDULER_cancel (t->destroy_task);
3855 t->destroy_task = NULL;
3858 if (NULL != t->trim_connections_task)
3860 LOG (GNUNET_ERROR_TYPE_DEBUG, "cancelling trim: %p\n",
3861 t->trim_connections_task);
3862 GNUNET_SCHEDULER_cancel (t->trim_connections_task);
3863 t->trim_connections_task = NULL;
3866 GNUNET_STATISTICS_update (stats, "# tunnels", -1, GNUNET_NO);
3867 GCP_set_tunnel (t->peer, NULL);
3869 if (NULL != t->rekey_task)
3871 GNUNET_SCHEDULER_cancel (t->rekey_task);
3872 t->rekey_task = NULL;
3874 if (NULL != t->kx_ctx)
3876 if (NULL != t->kx_ctx->finish_task)
3877 GNUNET_SCHEDULER_cancel (t->kx_ctx->finish_task);
3878 GNUNET_free (t->kx_ctx);
3889 * @brief Use the given path for the tunnel.
3890 * Update the next and prev hops (and RCs).
3891 * (Re)start the path refresh in case the tunnel is locally owned.
3893 * @param t Tunnel to update.
3894 * @param p Path to use.
3896 * @return Connection created.
3898 struct CadetConnection *
3899 GCT_use_path (struct CadetTunnel *t, struct CadetPeerPath *path)
3901 struct CadetConnection *c;
3902 struct GNUNET_CADET_Hash cid;
3903 unsigned int own_pos;
3905 if (NULL == t || NULL == path)
3911 if (CADET_TUNNEL_SHUTDOWN == t->cstate)
3917 for (own_pos = 0; own_pos < path->length; own_pos++)
3919 if (path->peers[own_pos] == myid)
3922 if (own_pos >= path->length)
3924 GNUNET_break_op (0);
3928 GNUNET_CRYPTO_random_block (GNUNET_CRYPTO_QUALITY_NONCE, &cid, sizeof (cid));
3929 c = GCC_new (&cid, t, path, own_pos);
3932 /* Path was flawed */
3935 GCT_add_connection (t, c);
3941 * Count all created connections of a tunnel. Not necessarily ready connections!
3943 * @param t Tunnel on which to count.
3945 * @return Number of connections created, either being established or ready.
3948 GCT_count_any_connections (struct CadetTunnel *t)
3950 struct CadetTConnection *iter;
3956 for (count = 0, iter = t->connection_head; NULL != iter; iter = iter->next)
3964 * Count established (ready) connections of a tunnel.
3966 * @param t Tunnel on which to count.
3968 * @return Number of connections.
3971 GCT_count_connections (struct CadetTunnel *t)
3973 struct CadetTConnection *iter;
3979 for (count = 0, iter = t->connection_head; NULL != iter; iter = iter->next)
3980 if (CADET_CONNECTION_READY == GCC_get_state (iter->c))
3988 * Count channels of a tunnel.
3990 * @param t Tunnel on which to count.
3992 * @return Number of channels.
3995 GCT_count_channels (struct CadetTunnel *t)
3997 struct CadetTChannel *iter;
4000 for (count = 0, iter = t->channel_head;
4002 iter = iter->next, count++) /* skip */;
4009 * Get the connectivity state of a tunnel.
4013 * @return Tunnel's connectivity state.
4015 enum CadetTunnelCState
4016 GCT_get_cstate (struct CadetTunnel *t)
4021 return (enum CadetTunnelCState) -1;
4028 * Get the encryption state of a tunnel.
4032 * @return Tunnel's encryption state.
4034 enum CadetTunnelEState
4035 GCT_get_estate (struct CadetTunnel *t)
4040 return (enum CadetTunnelEState) -1;
4046 * Get the maximum buffer space for a tunnel towards a local client.
4050 * @return Biggest buffer space offered by any channel in the tunnel.
4053 GCT_get_channels_buffer (struct CadetTunnel *t)
4055 struct CadetTChannel *iter;
4056 unsigned int buffer;
4057 unsigned int ch_buf;
4059 if (NULL == t->channel_head)
4061 /* Probably getting buffer for a channel create/handshake. */
4062 LOG (GNUNET_ERROR_TYPE_DEBUG, " no channels, allow max\n");
4063 return MIN_TUNNEL_BUFFER;
4067 for (iter = t->channel_head; NULL != iter; iter = iter->next)
4069 ch_buf = get_channel_buffer (iter);
4070 if (ch_buf > buffer)
4073 if (MIN_TUNNEL_BUFFER > buffer)
4074 return MIN_TUNNEL_BUFFER;
4076 if (MAX_TUNNEL_BUFFER < buffer)
4079 return MAX_TUNNEL_BUFFER;
4086 * Get the total buffer space for a tunnel for P2P traffic.
4090 * @return Buffer space offered by all connections in the tunnel.
4093 GCT_get_connections_buffer (struct CadetTunnel *t)
4095 struct CadetTConnection *iter;
4096 unsigned int buffer;
4098 if (GNUNET_NO == is_ready (t))
4100 if (count_queued_data (t) >= 3)
4107 for (iter = t->connection_head; NULL != iter; iter = iter->next)
4109 if (GCC_get_state (iter->c) != CADET_CONNECTION_READY)
4113 buffer += get_connection_buffer (iter);
4121 * Get the tunnel's destination.
4125 * @return ID of the destination peer.
4127 const struct GNUNET_PeerIdentity *
4128 GCT_get_destination (struct CadetTunnel *t)
4130 return GCP_get_id (t->peer);
4135 * Get the tunnel's next free global channel ID.
4139 * @return GID of a channel free to use.
4142 GCT_get_next_chid (struct CadetTunnel *t)
4144 CADET_ChannelNumber chid;
4145 CADET_ChannelNumber mask;
4148 /* Set bit 30 depending on the ID relationship. Bit 31 is always 0 for GID.
4149 * If our ID is bigger or loopback tunnel, start at 0, bit 30 = 0
4150 * If peer's ID is bigger, start at 0x4... bit 30 = 1
4152 result = GNUNET_CRYPTO_cmp_peer_identity (&my_full_id, GCP_get_id (t->peer));
4157 t->next_chid |= mask;
4159 while (NULL != GCT_get_channel (t, t->next_chid))
4161 LOG (GNUNET_ERROR_TYPE_DEBUG, "Channel %u exists...\n", t->next_chid);
4162 t->next_chid = (t->next_chid + 1) & ~GNUNET_CADET_LOCAL_CHANNEL_ID_CLI;
4163 t->next_chid |= mask;
4165 chid = t->next_chid;
4166 t->next_chid = (t->next_chid + 1) & ~GNUNET_CADET_LOCAL_CHANNEL_ID_CLI;
4167 t->next_chid |= mask;
4174 * Send ACK on one or more channels due to buffer in connections.
4176 * @param t Channel which has some free buffer space.
4179 GCT_unchoke_channels (struct CadetTunnel *t)
4181 struct CadetTChannel *iter;
4182 unsigned int buffer;
4183 unsigned int channels = GCT_count_channels (t);
4184 unsigned int choked_n;
4185 struct CadetChannel *choked[channels];
4187 LOG (GNUNET_ERROR_TYPE_DEBUG, "GCT_unchoke_channels on %s\n", GCT_2s (t));
4188 LOG (GNUNET_ERROR_TYPE_DEBUG, " head: %p\n", t->channel_head);
4189 if (NULL != t->channel_head)
4190 LOG (GNUNET_ERROR_TYPE_DEBUG, " head ch: %p\n", t->channel_head->ch);
4192 if (NULL != t->tq_head)
4193 send_queued_data (t);
4195 /* Get buffer space */
4196 buffer = GCT_get_connections_buffer (t);
4202 /* Count and remember choked channels */
4204 for (iter = t->channel_head; NULL != iter; iter = iter->next)
4206 if (GNUNET_NO == get_channel_allowed (iter))
4208 choked[choked_n++] = iter->ch;
4212 /* Unchoke random channels */
4213 while (0 < buffer && 0 < choked_n)
4215 unsigned int r = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK,
4217 GCCH_allow_client (choked[r], GCCH_is_origin (choked[r], GNUNET_YES));
4220 choked[r] = choked[choked_n];
4226 * Send ACK on one or more connections due to buffer space to the client.
4228 * Iterates all connections of the tunnel and sends ACKs appropriately.
4233 GCT_send_connection_acks (struct CadetTunnel *t)
4235 struct CadetTConnection *iter;
4238 uint32_t allow_per_connection;
4240 unsigned int buffer;
4242 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel send connection ACKs on %s\n",
4251 if (CADET_TUNNEL_READY != t->cstate)
4254 buffer = GCT_get_channels_buffer (t);
4255 LOG (GNUNET_ERROR_TYPE_DEBUG, " buffer %u\n", buffer);
4257 /* Count connections, how many messages are already allowed */
4258 cs = GCT_count_connections (t);
4259 for (allowed = 0, iter = t->connection_head; NULL != iter; iter = iter->next)
4261 allowed += get_connection_allowed (iter);
4263 LOG (GNUNET_ERROR_TYPE_DEBUG, " allowed %u\n", allowed);
4265 /* Make sure there is no overflow */
4266 if (allowed > buffer)
4269 /* Authorize connections to send more data */
4270 to_allow = buffer - allowed;
4272 for (iter = t->connection_head;
4273 NULL != iter && to_allow > 0;
4276 if (CADET_CONNECTION_READY != GCC_get_state (iter->c)
4277 || get_connection_allowed (iter) > 64 / 3)
4281 allow_per_connection = to_allow/cs;
4282 to_allow -= allow_per_connection;
4284 GCC_allow (iter->c, allow_per_connection,
4285 GCC_is_origin (iter->c, GNUNET_NO));
4290 /* Since we don't allow if it's allowed to send 64/3, this can happen. */
4291 LOG (GNUNET_ERROR_TYPE_DEBUG, " reminding to_allow: %u\n", to_allow);
4297 * Cancel a previously sent message while it's in the queue.
4299 * ONLY can be called before the continuation given to the send function
4300 * is called. Once the continuation is called, the message is no longer in the
4303 * @param q Handle to the queue.
4306 GCT_cancel (struct CadetTunnelQueue *q)
4310 GNUNET_assert (NULL == q->tqd);
4312 /* tun_message_sent() will be called and free q */
4314 else if (NULL != q->tqd)
4316 unqueue_data (q->tqd);
4318 if (NULL != q->cont)
4319 q->cont (q->cont_cls, NULL, q, 0, 0);
4330 * Check if the tunnel has queued traffic.
4332 * @param t Tunnel to check.
4334 * @return #GNUNET_YES if there is queued traffic
4335 * #GNUNET_NO otherwise
4338 GCT_has_queued_traffic (struct CadetTunnel *t)
4340 return (NULL != t->tq_head) ? GNUNET_YES : GNUNET_NO;
4345 * Sends an already built message on a tunnel, encrypting it and
4346 * choosing the best connection if not provided.
4348 * @param message Message to send. Function modifies it.
4349 * @param t Tunnel on which this message is transmitted.
4350 * @param c Connection to use (autoselect if NULL).
4351 * @param force Force the tunnel to take the message (buffer overfill).
4352 * @param cont Continuation to call once message is really sent.
4353 * @param cont_cls Closure for @c cont.
4355 * @return Handle to cancel message. NULL if @c cont is NULL.
4357 struct CadetTunnelQueue *
4358 GCT_send_prebuilt_message (const struct GNUNET_MessageHeader *message,
4359 struct CadetTunnel *t, struct CadetConnection *c,
4360 int force, GCT_sent cont, void *cont_cls)
4362 return send_prebuilt_message (message, t, c, force, cont, cont_cls, NULL);
4367 * Send an Axolotl KX message.
4369 * @param t Tunnel on which to send it.
4370 * @param force_reply Force the other peer to reply with a KX message.
4373 GCT_send_ax_kx (struct CadetTunnel *t, int force_reply)
4375 struct GNUNET_CADET_AX_KX msg;
4376 enum GNUNET_CADET_AX_KX_Flags flags;
4378 LOG (GNUNET_ERROR_TYPE_INFO, "===> AX_KX for %s\n", GCT_2s (t));
4379 if (NULL != t->ephm_h)
4381 LOG (GNUNET_ERROR_TYPE_INFO, " already queued\n");
4385 msg.header.size = htons (sizeof (msg));
4386 msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_AX_KX);
4387 flags = GNUNET_CADET_AX_KX_FLAG_NONE;
4389 flags |= GNUNET_CADET_AX_KX_FLAG_FORCE_REPLY;
4390 msg.flags = htonl (flags);
4391 GNUNET_CRYPTO_ecdhe_key_get_public (t->ax->kx_0, &msg.ephemeral_key);
4392 GNUNET_CRYPTO_ecdhe_key_get_public (t->ax->DHRs, &msg.ratchet_key);
4394 t->ephm_h = send_kx (t, &msg.header);
4395 if (CADET_TUNNEL_KEY_UNINITIALIZED == t->estate)
4396 GCT_change_estate (t, CADET_TUNNEL_KEY_SENT);
4401 * Sends an already built and encrypted message on a tunnel, choosing the best
4402 * connection. Useful for re-queueing messages queued on a destroyed connection.
4404 * @param message Message to send. Function modifies it.
4405 * @param t Tunnel on which this message is transmitted.
4408 GCT_resend_message (const struct GNUNET_MessageHeader *message,
4409 struct CadetTunnel *t)
4411 struct CadetConnection *c;
4414 c = tunnel_get_connection (t);
4417 /* TODO queue in tunnel, marked as encrypted */
4418 LOG (GNUNET_ERROR_TYPE_DEBUG, "No connection available, dropping.\n");
4421 fwd = GCC_is_origin (c, GNUNET_YES);
4422 GNUNET_break (NULL == GCC_send_prebuilt_message (message, 0, 0, c, fwd,
4423 GNUNET_YES, NULL, NULL));
4428 * Is the tunnel directed towards the local peer?
4432 * @return #GNUNET_YES if it is loopback.
4435 GCT_is_loopback (const struct CadetTunnel *t)
4437 return (myid == GCP_get_short_id (t->peer));
4442 * Is the tunnel this path already?
4447 * @return #GNUNET_YES a connection uses this path.
4450 GCT_is_path_used (const struct CadetTunnel *t, const struct CadetPeerPath *p)
4452 struct CadetTConnection *iter;
4454 for (iter = t->connection_head; NULL != iter; iter = iter->next)
4455 if (path_equivalent (GCC_get_path (iter->c), p))
4463 * Get a cost of a path for a tunnel considering existing connections.
4466 * @param path Candidate path.
4468 * @return Cost of the path (path length + number of overlapping nodes)
4471 GCT_get_path_cost (const struct CadetTunnel *t,
4472 const struct CadetPeerPath *path)
4474 struct CadetTConnection *iter;
4475 const struct CadetPeerPath *aux;
4476 unsigned int overlap;
4484 GNUNET_assert (NULL != t);
4486 for (i = 0; i < path->length; i++)
4488 for (iter = t->connection_head; NULL != iter; iter = iter->next)
4490 aux = GCC_get_path (iter->c);
4494 for (j = 0; j < aux->length; j++)
4496 if (path->peers[i] == aux->peers[j])
4504 return path->length + overlap;
4509 * Get the static string for the peer this tunnel is directed.
4513 * @return Static string the destination peer's ID.
4516 GCT_2s (const struct CadetTunnel *t)
4521 return GCP_2s (t->peer);
4525 /******************************************************************************/
4526 /***************************** INFO/DEBUG *******************************/
4527 /******************************************************************************/
4530 ax_debug (const struct CadetTunnelAxolotl *ax, enum GNUNET_ErrorType level)
4532 struct GNUNET_CRYPTO_EcdhePublicKey pub;
4533 struct CadetTunnelSkippedKey *iter;
4535 LOG2 (level, "TTT RK \t %s\n",
4536 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &ax->RK));
4538 LOG2 (level, "TTT HKs \t %s\n",
4539 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &ax->HKs));
4540 LOG2 (level, "TTT HKr \t %s\n",
4541 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &ax->HKr));
4542 LOG2 (level, "TTT NHKs\t %s\n",
4543 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &ax->NHKs));
4544 LOG2 (level, "TTT NHKr\t %s\n",
4545 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &ax->NHKr));
4547 LOG2 (level, "TTT CKs \t %s\n",
4548 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &ax->CKs));
4549 LOG2 (level, "TTT CKr \t %s\n",
4550 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &ax->CKr));
4552 GNUNET_CRYPTO_ecdhe_key_get_public (ax->DHRs, &pub);
4553 LOG2 (level, "TTT DHRs\t %s\n",
4554 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &pub));
4555 LOG2 (level, "TTT DHRr\t %s\n",
4556 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &ax->DHRr));
4558 LOG2 (level, "TTT Nr\t %u\tNs\t%u\n", ax->Nr, ax->Ns);
4559 LOG2 (level, "TTT PNs\t %u\tSkipped\t%u\n", ax->PNs, ax->skipped);
4560 LOG2 (level, "TTT Ratchet\t%u\n", ax->ratchet_flag);
4562 for (iter = ax->skipped_head; NULL != iter; iter = iter->next)
4564 LOG2 (level, "TTT HK\t %s\n",
4565 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &iter->HK));
4566 LOG2 (level, "TTT MK\t %s\n",
4567 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &iter->MK));
4572 * Log all possible info about the tunnel state.
4574 * @param t Tunnel to debug.
4575 * @param level Debug level to use.
4578 GCT_debug (const struct CadetTunnel *t, enum GNUNET_ErrorType level)
4580 struct CadetTChannel *iterch;
4581 struct CadetTConnection *iterc;
4584 do_log = GNUNET_get_log_call_status (level & (~GNUNET_ERROR_TYPE_BULK),
4586 __FILE__, __FUNCTION__, __LINE__);
4590 LOG2 (level, "TTT DEBUG TUNNEL TOWARDS %s\n", GCT_2s (t));
4591 LOG2 (level, "TTT cstate %s, estate %s\n",
4592 cstate2s (t->cstate), estate2s (t->estate));
4593 LOG2 (level, "TTT kx_ctx %p, rekey_task %u, finish task %u\n",
4594 t->kx_ctx, t->rekey_task, t->kx_ctx ? t->kx_ctx->finish_task : 0);
4595 #if DUMP_KEYS_TO_STDERR
4596 if (CADET_Axolotl == t->enc_type)
4598 ax_debug (t->ax, level);
4602 LOG2 (level, "TTT my EPHM\t %s\n",
4603 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &otr_kx_msg.ephemeral_key));
4604 LOG2 (level, "TTT peers EPHM:\t %s\n",
4605 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &t->peers_ephemeral_key));
4606 LOG2 (level, "TTT ENC key:\t %s\n",
4607 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &t->e_key));
4608 LOG2 (level, "TTT DEC key:\t %s\n",
4609 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &t->d_key));
4612 LOG2 (level, "TTT OLD ENC key:\t %s\n",
4613 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &t->kx_ctx->e_key_old));
4614 LOG2 (level, "TTT OLD DEC key:\t %s\n",
4615 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &t->kx_ctx->d_key_old));
4619 LOG2 (level, "TTT tq_head %p, tq_tail %p\n", t->tq_head, t->tq_tail);
4620 LOG2 (level, "TTT destroy %p\n", t->destroy_task);
4622 LOG2 (level, "TTT channels:\n");
4623 for (iterch = t->channel_head; NULL != iterch; iterch = iterch->next)
4625 GCCH_debug (iterch->ch, level);
4628 LOG2 (level, "TTT connections:\n");
4629 for (iterc = t->connection_head; NULL != iterc; iterc = iterc->next)
4631 GCC_debug (iterc->c, level);
4634 LOG2 (level, "TTT DEBUG TUNNEL END\n");
4639 * Iterate all tunnels.
4641 * @param iter Iterator.
4642 * @param cls Closure for @c iter.
4645 GCT_iterate_all (GNUNET_CONTAINER_PeerMapIterator iter, void *cls)
4647 GNUNET_CONTAINER_multipeermap_iterate (tunnels, iter, cls);
4652 * Count all tunnels.
4654 * @return Number of tunnels to remote peers kept by this peer.
4657 GCT_count_all (void)
4659 return GNUNET_CONTAINER_multipeermap_size (tunnels);
4664 * Iterate all connections of a tunnel.
4666 * @param t Tunnel whose connections to iterate.
4667 * @param iter Iterator.
4668 * @param cls Closure for @c iter.
4671 GCT_iterate_connections (struct CadetTunnel *t, GCT_conn_iter iter, void *cls)
4673 struct CadetTConnection *ct;
4675 for (ct = t->connection_head; NULL != ct; ct = ct->next)
4681 * Iterate all channels of a tunnel.
4683 * @param t Tunnel whose channels to iterate.
4684 * @param iter Iterator.
4685 * @param cls Closure for @c iter.
4688 GCT_iterate_channels (struct CadetTunnel *t, GCT_chan_iter iter, void *cls)
4690 struct CadetTChannel *cht;
4692 for (cht = t->channel_head; NULL != cht; cht = cht->next)
4693 iter (cls, cht->ch);