2 This file is part of GNUnet.
3 Copyright (C) 2013 GNUnet e.V.
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");
1113 t_hmac_derive_key (&ax->CKr, &MK, "0", 1);
1114 GNUNET_CRYPTO_symmetric_derive_iv (&iv, &MK, NULL, 0, NULL);
1116 #if DUMP_KEYS_TO_STDERR
1117 LOG (GNUNET_ERROR_TYPE_DEBUG, " CKr: %s\n",
1118 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &ax->CKr));
1119 LOG (GNUNET_ERROR_TYPE_INFO, " AX_DEC with key %u: %s\n", ax->Nr,
1120 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &MK));
1123 GNUNET_assert (size >= sizeof (struct GNUNET_MessageHeader));
1124 out_size = GNUNET_CRYPTO_symmetric_decrypt (src, size, &MK, &iv, dst);
1125 GNUNET_assert (out_size == size);
1127 t_hmac_derive_key (&ax->CKr, &ax->CKr, "1", 1);
1129 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_ax_decrypt end\n");
1136 * Encrypt header with the axolotl header key.
1138 * @param t Tunnel whose key to use.
1139 * @param msg Message whose header to encrypt.
1142 t_h_encrypt (struct CadetTunnel *t, struct GNUNET_CADET_AX *msg)
1144 struct GNUNET_CRYPTO_SymmetricInitializationVector iv;
1145 struct CadetTunnelAxolotl *ax;
1148 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_h_encrypt start\n");
1151 GNUNET_CRYPTO_symmetric_derive_iv (&iv, &ax->HKs, NULL, 0, NULL);
1153 #if DUMP_KEYS_TO_STDERR
1154 LOG (GNUNET_ERROR_TYPE_INFO, " AX_ENC_H with key %s\n",
1155 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &ax->HKs));
1158 out_size = GNUNET_CRYPTO_symmetric_encrypt (&msg->Ns, AX_HEADER_SIZE,
1159 &ax->HKs, &iv, &msg->Ns);
1161 GNUNET_assert (AX_HEADER_SIZE == out_size);
1163 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_ax_encrypt end\n");
1168 * Decrypt header with the current axolotl header key.
1170 * @param t Tunnel whose current ax HK to use.
1171 * @param src Message whose header to decrypt.
1172 * @param dst Where to decrypt header to.
1175 t_h_decrypt (struct CadetTunnel *t, const struct GNUNET_CADET_AX *src,
1176 struct GNUNET_CADET_AX *dst)
1178 struct GNUNET_CRYPTO_SymmetricInitializationVector iv;
1179 struct CadetTunnelAxolotl *ax;
1182 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_h_decrypt start\n");
1185 GNUNET_CRYPTO_symmetric_derive_iv (&iv, &ax->HKr, NULL, 0, NULL);
1187 #if DUMP_KEYS_TO_STDERR
1188 LOG (GNUNET_ERROR_TYPE_INFO, " AX_DEC_H with key %s\n",
1189 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &ax->HKr));
1192 out_size = GNUNET_CRYPTO_symmetric_decrypt (&src->Ns, AX_HEADER_SIZE,
1193 &ax->HKr, &iv, &dst->Ns);
1195 GNUNET_assert (AX_HEADER_SIZE == out_size);
1197 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_h_decrypt end\n");
1202 * Decrypt and verify data with the appropriate tunnel key.
1204 * @param key Key to use.
1205 * @param dst Destination for the plaintext.
1206 * @param src Source of the encrypted data. Can overlap with @c dst.
1207 * @param size Size of the encrypted data.
1208 * @param iv Initialization Vector to use.
1210 * @return Size of the decrypted data, -1 if an error was encountered.
1213 decrypt (const struct GNUNET_CRYPTO_SymmetricSessionKey *key,
1214 void *dst, const void *src, size_t size, uint32_t iv)
1216 struct GNUNET_CRYPTO_SymmetricInitializationVector siv;
1219 LOG (GNUNET_ERROR_TYPE_DEBUG, " decrypt start\n");
1220 LOG (GNUNET_ERROR_TYPE_DEBUG, " decrypt iv\n");
1221 GNUNET_CRYPTO_symmetric_derive_iv (&siv, key, &iv, sizeof (iv), NULL);
1222 LOG (GNUNET_ERROR_TYPE_DEBUG, " decrypt iv done\n");
1223 out_size = GNUNET_CRYPTO_symmetric_decrypt (src, size, key, &siv, dst);
1224 LOG (GNUNET_ERROR_TYPE_DEBUG, " decrypt end\n");
1231 * Decrypt and verify data with the most recent tunnel key.
1233 * @param t Tunnel whose key to use.
1234 * @param dst Destination for the plaintext.
1235 * @param src Source of the encrypted data. Can overlap with @c dst.
1236 * @param size Size of the encrypted data.
1237 * @param iv Initialization Vector to use.
1239 * @return Size of the decrypted data, -1 if an error was encountered.
1242 t_decrypt (struct CadetTunnel *t, void *dst, const void *src,
1243 size_t size, uint32_t iv)
1247 #if DUMP_KEYS_TO_STDERR
1248 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_decrypt with %s\n",
1249 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &t->d_key));
1251 if (CADET_TUNNEL_KEY_UNINITIALIZED == t->estate)
1253 GNUNET_STATISTICS_update (stats, "# non decryptable data", 1, GNUNET_NO);
1254 LOG (GNUNET_ERROR_TYPE_WARNING,
1255 "got data on %s without a valid key\n",
1257 GCT_debug (t, GNUNET_ERROR_TYPE_WARNING);
1261 out_size = decrypt (&t->d_key, dst, src, size, iv);
1268 * Decrypt and verify data with the appropriate tunnel key and verify that the
1269 * data has not been altered since it was sent by the remote peer.
1271 * @param t Tunnel whose key to use.
1272 * @param dst Destination for the plaintext.
1273 * @param src Source of the encrypted data. Can overlap with @c dst.
1274 * @param size Size of the encrypted data.
1275 * @param iv Initialization Vector to use.
1276 * @param msg_hmac HMAC of the message, cannot be NULL.
1278 * @return Size of the decrypted data, -1 if an error was encountered.
1281 t_decrypt_and_validate (struct CadetTunnel *t,
1282 void *dst, const void *src,
1283 size_t size, uint32_t iv,
1284 const struct GNUNET_CADET_Hash *msg_hmac)
1286 struct GNUNET_CRYPTO_SymmetricSessionKey *key;
1287 struct GNUNET_CADET_Hash hmac;
1290 /* Try primary (newest) key */
1292 decrypted_size = decrypt (key, dst, src, size, iv);
1293 t_hmac (src, size, iv, key, &hmac);
1294 if (0 == memcmp (msg_hmac, &hmac, sizeof (hmac)))
1295 return decrypted_size;
1297 /* If no key exchange is going on, we just failed. */
1298 if (NULL == t->kx_ctx)
1300 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
1301 "Failed checksum validation on tunnel %s with no KX\n",
1303 GNUNET_STATISTICS_update (stats, "# wrong HMAC no KX", 1, GNUNET_NO);
1307 /* Try secondary key, from previous KX period. */
1308 key = &t->kx_ctx->d_key_old;
1309 decrypted_size = decrypt (key, dst, src, size, iv);
1310 t_hmac (src, size, iv, key, &hmac);
1311 if (0 == memcmp (msg_hmac, &hmac, sizeof (hmac)))
1312 return decrypted_size;
1314 /* Hail Mary, try tertiary, key, in case of parallel re-keys. */
1315 key = &t->kx_ctx->d_key_old2;
1316 decrypted_size = decrypt (key, dst, src, size, iv);
1317 t_hmac (src, size, iv, key, &hmac);
1318 if (0 == memcmp (msg_hmac, &hmac, sizeof (hmac)))
1319 return decrypted_size;
1321 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
1322 "Failed checksum validation on tunnel %s with KX\n",
1324 GNUNET_STATISTICS_update (stats, "# wrong HMAC with KX", 1, GNUNET_NO);
1330 * Decrypt and verify data with the appropriate tunnel key and verify that the
1331 * data has not been altered since it was sent by the remote peer.
1333 * @param t Tunnel whose key to use.
1334 * @param dst Destination for the plaintext.
1335 * @param src Source of the message. Can overlap with @c dst.
1336 * @param size Size of the message.
1338 * @return Size of the decrypted data, -1 if an error was encountered.
1341 try_old_ax_keys (struct CadetTunnel *t, void *dst,
1342 const struct GNUNET_CADET_AX *src, size_t size)
1344 struct CadetTunnelSkippedKey *key;
1345 struct GNUNET_CADET_Hash *hmac;
1346 struct GNUNET_CRYPTO_SymmetricInitializationVector iv;
1347 struct GNUNET_CADET_AX plaintext_header;
1348 struct GNUNET_CRYPTO_SymmetricSessionKey *valid_HK;
1354 LOG (GNUNET_ERROR_TYPE_DEBUG, "Trying old keys\n");
1355 hmac = &plaintext_header.hmac;
1356 esize = size - sizeof (struct GNUNET_CADET_AX);
1358 /* Find a correct Header Key */
1359 for (key = t->ax->skipped_head; NULL != key; key = key->next)
1361 #if DUMP_KEYS_TO_STDERR
1362 LOG (GNUNET_ERROR_TYPE_DEBUG, " Trying hmac with key %s\n",
1363 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &key->HK));
1365 t_hmac (&src->Ns, AX_HEADER_SIZE + esize, 0, &key->HK, hmac);
1366 if (0 == memcmp (hmac, &src->hmac, sizeof (*hmac)))
1368 LOG (GNUNET_ERROR_TYPE_DEBUG, " hmac correct\n");
1369 valid_HK = &key->HK;
1376 /* Should've been checked in -cadet_connection.c handle_cadet_encrypted. */
1377 GNUNET_assert (size > sizeof (struct GNUNET_CADET_AX));
1378 len = size - sizeof (struct GNUNET_CADET_AX);
1379 GNUNET_assert (len >= sizeof (struct GNUNET_MessageHeader));
1381 /* Decrypt header */
1382 GNUNET_CRYPTO_symmetric_derive_iv (&iv, &key->HK, NULL, 0, NULL);
1383 res = GNUNET_CRYPTO_symmetric_decrypt (&src->Ns, AX_HEADER_SIZE,
1384 &key->HK, &iv, &plaintext_header.Ns);
1385 GNUNET_assert (AX_HEADER_SIZE == res);
1386 LOG (GNUNET_ERROR_TYPE_DEBUG, " Message %u, previous: %u\n",
1387 ntohl (plaintext_header.Ns), ntohl (plaintext_header.PNs));
1389 /* Find the correct Message Key */
1390 N = ntohl (plaintext_header.Ns);
1391 while (NULL != key && N != key->Kn)
1393 if (NULL == key || 0 != memcmp (&key->HK, valid_HK, sizeof (*valid_HK)))
1396 #if DUMP_KEYS_TO_STDERR
1397 LOG (GNUNET_ERROR_TYPE_INFO, " AX_DEC_H with skipped key %s\n",
1398 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &key->HK));
1399 LOG (GNUNET_ERROR_TYPE_INFO, " AX_DEC with skipped key %u: %s\n",
1400 key->Kn, GNUNET_i2s ((struct GNUNET_PeerIdentity *) &key->MK));
1403 /* Decrypt payload */
1404 GNUNET_CRYPTO_symmetric_derive_iv (&iv, &key->MK, NULL, 0, NULL);
1405 res = GNUNET_CRYPTO_symmetric_decrypt (&src[1], len, &key->MK, &iv, dst);
1408 GNUNET_CONTAINER_DLL_remove (t->ax->skipped_head, t->ax->skipped_tail, key);
1410 GNUNET_free (key); /* GNUNET_free overwrites memory with 0xbaadf00d */
1417 * Delete a key from the list of skipped keys.
1419 * @param t Tunnel to delete from.
1420 * @param HKr Header Key to use.
1423 store_skipped_key (struct CadetTunnel *t,
1424 const struct GNUNET_CRYPTO_SymmetricSessionKey *HKr)
1426 struct CadetTunnelSkippedKey *key;
1428 key = GNUNET_new (struct CadetTunnelSkippedKey);
1429 key->timestamp = GNUNET_TIME_absolute_get ();
1430 key->Kn = t->ax->Nr;
1431 key->HK = t->ax->HKr;
1432 t_hmac_derive_key (&t->ax->CKr, &key->MK, "0", 1);
1433 #if DUMP_KEYS_TO_STDERR
1434 LOG (GNUNET_ERROR_TYPE_DEBUG, " storing MK for Nr %u: %s\n",
1435 key->Kn, GNUNET_i2s ((struct GNUNET_PeerIdentity *) &key->MK));
1436 LOG (GNUNET_ERROR_TYPE_DEBUG, " for CKr: %s\n",
1437 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &t->ax->CKr));
1439 t_hmac_derive_key (&t->ax->CKr, &t->ax->CKr, "1", 1);
1440 GNUNET_CONTAINER_DLL_insert (t->ax->skipped_head, t->ax->skipped_tail, key);
1447 * Delete a key from the list of skipped keys.
1449 * @param t Tunnel to delete from.
1450 * @param key Key to delete.
1453 delete_skipped_key (struct CadetTunnel *t, struct CadetTunnelSkippedKey *key)
1455 GNUNET_CONTAINER_DLL_remove (t->ax->skipped_head, t->ax->skipped_tail, key);
1462 * Stage skipped AX keys and calculate the message key.
1464 * Stores each HK and MK for skipped messages.
1466 * @param t Tunnel where to stage the keys.
1467 * @param HKr Header key.
1468 * @param Np Received meesage number.
1470 * @return GNUNET_OK if keys were stored.
1471 * GNUNET_SYSERR if an error ocurred (Np not expected).
1474 store_ax_keys (struct CadetTunnel *t,
1475 const struct GNUNET_CRYPTO_SymmetricSessionKey *HKr,
1481 gap = Np - t->ax->Nr;
1482 LOG (GNUNET_ERROR_TYPE_INFO, "Storing keys [%u, %u)\n", t->ax->Nr, Np);
1483 if (MAX_KEY_GAP < gap)
1485 /* Avoid DoS (forcing peer to do 2*33 chain HMAC operations) */
1486 /* TODO: start new key exchange on return */
1487 GNUNET_break_op (0);
1488 LOG (GNUNET_ERROR_TYPE_WARNING, "Got message %u, expected %u+\n",
1490 return GNUNET_SYSERR;
1494 /* Delayed message: don't store keys, flag to try old keys. */
1495 return GNUNET_SYSERR;
1498 while (t->ax->Nr < Np)
1499 store_skipped_key (t, HKr);
1501 while (t->ax->skipped > MAX_SKIPPED_KEYS)
1502 delete_skipped_key (t, t->ax->skipped_tail);
1509 * Decrypt and verify data with the appropriate tunnel key and verify that the
1510 * data has not been altered since it was sent by the remote peer.
1512 * @param t Tunnel whose key to use.
1513 * @param dst Destination for the plaintext.
1514 * @param src Source of the message. Can overlap with @c dst.
1515 * @param size Size of the message.
1517 * @return Size of the decrypted data, -1 if an error was encountered.
1520 t_ax_decrypt_and_validate (struct CadetTunnel *t, void *dst,
1521 const struct GNUNET_CADET_AX *src, size_t size)
1523 struct CadetTunnelAxolotl *ax;
1524 struct GNUNET_CADET_Hash msg_hmac;
1525 struct GNUNET_HashCode hmac;
1526 struct GNUNET_CADET_AX plaintext_header;
1533 esize = size - sizeof (struct GNUNET_CADET_AX);
1538 /* Try current HK */
1539 t_hmac (&src->Ns, AX_HEADER_SIZE + esize, 0, &ax->HKr, &msg_hmac);
1540 if (0 != memcmp (&msg_hmac, &src->hmac, sizeof (msg_hmac)))
1542 static const char ctx[] = "axolotl ratchet";
1543 struct GNUNET_CRYPTO_SymmetricSessionKey keys[3]; /* RKp, NHKp, CKp */
1544 struct GNUNET_CRYPTO_SymmetricSessionKey HK;
1545 struct GNUNET_HashCode dh;
1546 struct GNUNET_CRYPTO_EcdhePublicKey *DHRp;
1549 LOG (GNUNET_ERROR_TYPE_DEBUG, " trying next HK\n");
1550 t_hmac (&src->Ns, AX_HEADER_SIZE + esize, 0, &ax->NHKr, &msg_hmac);
1551 if (0 != memcmp (&msg_hmac, &src->hmac, sizeof (msg_hmac)))
1553 /* Try the skipped keys, if that fails, we're out of luck. */
1554 return try_old_ax_keys (t, dst, src, size);
1556 LOG (GNUNET_ERROR_TYPE_INFO, "next HK worked\n");
1560 t_h_decrypt (t, src, &plaintext_header);
1561 Np = ntohl (plaintext_header.Ns);
1562 PNp = ntohl (plaintext_header.PNs);
1563 DHRp = &plaintext_header.DHRs;
1564 store_ax_keys (t, &HK, PNp);
1566 /* RKp, NHKp, CKp = KDF (HMAC-HASH (RK, DH (DHRp, DHRs))) */
1567 GNUNET_CRYPTO_ecc_ecdh (ax->DHRs, DHRp, &dh);
1568 t_ax_hmac_hash (&ax->RK, &hmac, &dh, sizeof (dh));
1569 GNUNET_CRYPTO_kdf (keys, sizeof (keys), ctx, sizeof (ctx),
1570 &hmac, sizeof (hmac), NULL);
1572 /* Commit "purported" keys */
1578 ax->ratchet_allowed = GNUNET_YES;
1582 LOG (GNUNET_ERROR_TYPE_DEBUG, "current HK\n");
1583 t_h_decrypt (t, src, &plaintext_header);
1584 Np = ntohl (plaintext_header.Ns);
1585 PNp = ntohl (plaintext_header.PNs);
1587 LOG (GNUNET_ERROR_TYPE_INFO, " got AX Nr %u\n", Np);
1589 if (GNUNET_OK != store_ax_keys (t, &ax->HKr, Np))
1590 /* Try the skipped keys, if that fails, we're out of luck. */
1591 return try_old_ax_keys (t, dst, src, size);
1593 osize = t_ax_decrypt (t, dst, &src[1], esize);
1598 GNUNET_break_op (0);
1607 * Create key material by doing ECDH on the local and remote ephemeral keys.
1609 * @param key_material Where to store the key material.
1610 * @param ephemeral Peer's public ephemeral key.
1612 * @return GNUNET_OK if it went fine, GNUNET_SYSERR otherwise.
1615 derive_otr_key_material (struct GNUNET_HashCode *key_material,
1616 const struct GNUNET_CRYPTO_EcdhePublicKey *ephemeral)
1619 GNUNET_CRYPTO_ecc_ecdh (otr_ephemeral_key, ephemeral, key_material))
1622 return GNUNET_SYSERR;
1629 * Create a symmetic key from the identities of both ends and the key material
1632 * @param key Destination for the generated key.
1633 * @param sender ID of the peer that will encrypt with @c key.
1634 * @param receiver ID of the peer that will decrypt with @c key.
1635 * @param key_material Hash created with ECDH with the ephemeral keys.
1638 derive_symmertic (struct GNUNET_CRYPTO_SymmetricSessionKey *key,
1639 const struct GNUNET_PeerIdentity *sender,
1640 const struct GNUNET_PeerIdentity *receiver,
1641 const struct GNUNET_HashCode *key_material)
1643 const char salt[] = "CADET kx salt";
1645 GNUNET_CRYPTO_kdf (key, sizeof (struct GNUNET_CRYPTO_SymmetricSessionKey),
1646 salt, sizeof (salt),
1647 key_material, sizeof (struct GNUNET_HashCode),
1648 sender, sizeof (struct GNUNET_PeerIdentity),
1649 receiver, sizeof (struct GNUNET_PeerIdentity),
1655 * Derive the tunnel's keys using our own and the peer's ephemeral keys.
1657 * @param t Tunnel for which to create the keys.
1659 * @return GNUNET_OK if successful, GNUNET_SYSERR otherwise.
1662 create_otr_keys (struct CadetTunnel *t)
1664 struct GNUNET_HashCode km;
1666 if (GNUNET_OK != derive_otr_key_material (&km, &t->peers_ephemeral_key))
1667 return GNUNET_SYSERR;
1668 derive_symmertic (&t->e_key, &my_full_id, GCP_get_id (t->peer), &km);
1669 derive_symmertic (&t->d_key, GCP_get_id (t->peer), &my_full_id, &km);
1670 #if DUMP_KEYS_TO_STDERR
1671 LOG (GNUNET_ERROR_TYPE_INFO, "ME: %s\n",
1672 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &otr_kx_msg.ephemeral_key));
1673 LOG (GNUNET_ERROR_TYPE_INFO, "PE: %s\n",
1674 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &t->peers_ephemeral_key));
1675 LOG (GNUNET_ERROR_TYPE_INFO, "KM: %s\n", GNUNET_h2s (&km));
1676 LOG (GNUNET_ERROR_TYPE_INFO, "EK: %s\n",
1677 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &t->e_key));
1678 LOG (GNUNET_ERROR_TYPE_INFO, "DK: %s\n",
1679 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &t->d_key));
1686 * Create a new Key eXchange context for the tunnel.
1688 * If the old keys were verified, keep them for old traffic. Create a new KX
1689 * timestamp and a new nonce.
1691 * @param t Tunnel for which to create the KX ctx.
1693 * @return GNUNET_OK if successful, GNUNET_SYSERR otherwise.
1696 create_kx_ctx (struct CadetTunnel *t)
1698 LOG (GNUNET_ERROR_TYPE_INFO, " new kx ctx for %s\n", GCT_2s (t));
1700 if (NULL != t->kx_ctx)
1702 if (NULL != t->kx_ctx->finish_task)
1704 LOG (GNUNET_ERROR_TYPE_INFO, " resetting exisiting finish task\n");
1705 GNUNET_SCHEDULER_cancel (t->kx_ctx->finish_task);
1706 t->kx_ctx->finish_task = NULL;
1711 t->kx_ctx = GNUNET_new (struct CadetTunnelKXCtx);
1712 t->kx_ctx->challenge = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE,
1716 if (CADET_TUNNEL_KEY_OK == t->estate)
1718 LOG (GNUNET_ERROR_TYPE_INFO, " backing up keys\n");
1719 t->kx_ctx->d_key_old = t->d_key;
1720 t->kx_ctx->e_key_old = t->e_key;
1723 LOG (GNUNET_ERROR_TYPE_INFO, " old keys not valid, not saving\n");
1724 t->kx_ctx->rekey_start_time = GNUNET_TIME_absolute_get ();
1725 return create_otr_keys (t);
1730 * @brief Finish the Key eXchange and destroy the old keys.
1732 * @param cls Closure (Tunnel for which to finish the KX).
1735 finish_kx (void *cls)
1737 struct CadetTunnel *t = cls;
1739 LOG (GNUNET_ERROR_TYPE_INFO, "finish KX for %s\n", GCT_2s (t));
1740 GNUNET_free (t->kx_ctx);
1746 * Destroy a Key eXchange context for the tunnel. This function only schedules
1747 * the destruction, the freeing of the memory (and clearing of old key material)
1748 * happens after a delay!
1750 * @param t Tunnel whose KX ctx to destroy.
1753 destroy_kx_ctx (struct CadetTunnel *t)
1755 struct GNUNET_TIME_Relative delay;
1757 if (NULL == t->kx_ctx || NULL != t->kx_ctx->finish_task)
1760 if (is_key_null (&t->kx_ctx->e_key_old))
1762 t->kx_ctx->finish_task = GNUNET_SCHEDULER_add_now (&finish_kx, t);
1766 delay = GNUNET_TIME_relative_divide (rekey_period, 4);
1767 delay = GNUNET_TIME_relative_min (delay, GNUNET_TIME_UNIT_MINUTES);
1769 t->kx_ctx->finish_task = GNUNET_SCHEDULER_add_delayed (delay,
1776 * Pick a connection on which send the next data message.
1778 * @param t Tunnel on which to send the message.
1780 * @return The connection on which to send the next message.
1782 static struct CadetConnection *
1783 tunnel_get_connection (struct CadetTunnel *t)
1785 struct CadetTConnection *iter;
1786 struct CadetConnection *best;
1788 unsigned int lowest_q;
1790 LOG (GNUNET_ERROR_TYPE_DEBUG, "tunnel_get_connection %s\n", GCT_2s (t));
1792 lowest_q = UINT_MAX;
1793 for (iter = t->connection_head; NULL != iter; iter = iter->next)
1795 LOG (GNUNET_ERROR_TYPE_DEBUG, " connection %s: %u\n",
1796 GCC_2s (iter->c), GCC_get_state (iter->c));
1797 if (CADET_CONNECTION_READY == GCC_get_state (iter->c))
1799 qn = GCC_get_qn (iter->c, GCC_is_origin (iter->c, GNUNET_YES));
1800 LOG (GNUNET_ERROR_TYPE_DEBUG, " q_n %u, \n", qn);
1808 LOG (GNUNET_ERROR_TYPE_DEBUG, " selected: connection %s\n", GCC_2s (best));
1814 * Callback called when a queued message is sent.
1816 * Calculates the average time and connection packet tracking.
1818 * @param cls Closure (TunnelQueue handle).
1819 * @param c Connection this message was on.
1820 * @param q Connection queue handle (unused).
1821 * @param type Type of message sent.
1822 * @param fwd Was this a FWD going message?
1823 * @param size Size of the message.
1826 tun_message_sent (void *cls,
1827 struct CadetConnection *c,
1828 struct CadetConnectionQueue *q,
1829 uint16_t type, int fwd, size_t size)
1831 struct CadetTunnelQueue *qt = cls;
1832 struct CadetTunnel *t;
1834 LOG (GNUNET_ERROR_TYPE_DEBUG, "tun_message_sent\n");
1836 GNUNET_assert (NULL != qt->cont);
1837 t = NULL == c ? NULL : GCC_get_tunnel (c);
1838 qt->cont (qt->cont_cls, t, qt, type, size);
1844 count_queued_data (const struct CadetTunnel *t)
1846 struct CadetTunnelDelayed *iter;
1849 for (count = 0, iter = t->tq_head; iter != NULL; iter = iter->next)
1856 * Delete a queued message: either was sent or the channel was destroyed
1857 * before the tunnel's key exchange had a chance to finish.
1859 * @param tqd Delayed queue handle.
1862 unqueue_data (struct CadetTunnelDelayed *tqd)
1864 GNUNET_CONTAINER_DLL_remove (tqd->t->tq_head, tqd->t->tq_tail, tqd);
1870 * Cache a message to be sent once tunnel is online.
1872 * @param t Tunnel to hold the message.
1873 * @param msg Message itself (copy will be made).
1875 static struct CadetTunnelDelayed *
1876 queue_data (struct CadetTunnel *t, const struct GNUNET_MessageHeader *msg)
1878 struct CadetTunnelDelayed *tqd;
1879 uint16_t size = ntohs (msg->size);
1881 LOG (GNUNET_ERROR_TYPE_DEBUG, "queue data on Tunnel %s\n", GCT_2s (t));
1883 GNUNET_assert (GNUNET_NO == is_ready (t));
1885 tqd = GNUNET_malloc (sizeof (struct CadetTunnelDelayed) + size);
1888 memcpy (&tqd[1], msg, size);
1889 GNUNET_CONTAINER_DLL_insert_tail (t->tq_head, t->tq_tail, tqd);
1895 * Sends an already built message on a tunnel, encrypting it and
1896 * choosing the best connection.
1898 * @param message Message to send. Function modifies it.
1899 * @param t Tunnel on which this message is transmitted.
1900 * @param c Connection to use (autoselect if NULL).
1901 * @param force Force the tunnel to take the message (buffer overfill).
1902 * @param cont Continuation to call once message is really sent.
1903 * @param cont_cls Closure for @c cont.
1904 * @param existing_q In case this a transmission of previously queued data,
1905 * this should be TunnelQueue given to the client.
1908 * @return Handle to cancel message.
1909 * NULL if @c cont is NULL or an error happens and message is dropped.
1911 static struct CadetTunnelQueue *
1912 send_prebuilt_message (const struct GNUNET_MessageHeader *message,
1913 struct CadetTunnel *t, struct CadetConnection *c,
1914 int force, GCT_sent cont, void *cont_cls,
1915 struct CadetTunnelQueue *existing_q)
1917 struct GNUNET_MessageHeader *msg;
1918 struct GNUNET_CADET_Encrypted *otr_msg;
1919 struct GNUNET_CADET_AX *ax_msg;
1920 struct CadetTunnelQueue *tq;
1921 size_t size = ntohs (message->size);
1922 const uint16_t max_overhead = sizeof (struct GNUNET_CADET_Encrypted)
1923 + sizeof (struct GNUNET_CADET_AX);
1924 char cbuf[max_overhead + size];
1931 LOG (GNUNET_ERROR_TYPE_DEBUG, "GMT Send on Tunnel %s\n", GCT_2s (t));
1933 if (GNUNET_NO == is_ready (t))
1935 struct CadetTunnelDelayed *tqd;
1936 /* A non null existing_q indicates sending of queued data.
1937 * Should only happen after tunnel becomes ready.
1939 GNUNET_assert (NULL == existing_q);
1940 tqd = queue_data (t, message);
1943 tq = GNUNET_new (struct CadetTunnelQueue);
1947 tq->cont_cls = cont_cls;
1951 GNUNET_assert (GNUNET_NO == GCT_is_loopback (t));
1953 if (CADET_Axolotl == t->enc_type)
1955 ax_msg = (struct GNUNET_CADET_AX *) cbuf;
1956 msg = &ax_msg->header;
1957 msg->size = htons (sizeof (struct GNUNET_CADET_AX) + size);
1958 msg->type = htons (GNUNET_MESSAGE_TYPE_CADET_AX);
1959 ax_msg->reserved = 0;
1960 esize = t_ax_encrypt (t, &ax_msg[1], message, size);
1961 ax_msg->Ns = htonl (t->ax->Ns++);
1962 ax_msg->PNs = htonl (t->ax->PNs);
1963 GNUNET_CRYPTO_ecdhe_key_get_public (t->ax->DHRs, &ax_msg->DHRs);
1964 t_h_encrypt (t, ax_msg);
1965 t_hmac (&ax_msg->Ns, AX_HEADER_SIZE + esize, 0, &t->ax->HKs, &ax_msg->hmac);
1969 otr_msg = (struct GNUNET_CADET_Encrypted *) cbuf;
1970 msg = &otr_msg->header;
1971 iv = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX);
1973 esize = t_encrypt (t, &otr_msg[1], message, size, iv, GNUNET_NO);
1974 t_hmac (&otr_msg[1], size, iv, select_key (t), &otr_msg->hmac);
1975 msg->size = htons (sizeof (struct GNUNET_CADET_Encrypted) + size);
1976 msg->type = htons (GNUNET_MESSAGE_TYPE_CADET_ENCRYPTED);
1977 otr_msg->ttl = htonl (default_ttl);
1979 GNUNET_assert (esize == size);
1982 c = tunnel_get_connection (t);
1985 /* Why is tunnel 'ready'? Should have been queued! */
1986 if (NULL != t->destroy_task)
1989 GCT_debug (t, GNUNET_ERROR_TYPE_WARNING);
1991 return NULL; /* Drop... */
1995 type = ntohs (message->type);
1998 case GNUNET_MESSAGE_TYPE_CADET_DATA:
1999 case GNUNET_MESSAGE_TYPE_CADET_DATA_ACK:
2000 if (GNUNET_MESSAGE_TYPE_CADET_DATA == type)
2001 mid = ntohl (((struct GNUNET_CADET_Data *) message)->mid);
2003 mid = ntohl (((struct GNUNET_CADET_DataACK *) message)->mid);
2005 case GNUNET_MESSAGE_TYPE_CADET_KEEPALIVE:
2006 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_CREATE:
2007 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_DESTROY:
2008 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_ACK:
2009 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_NACK:
2013 LOG (GNUNET_ERROR_TYPE_ERROR, "type %s not valid\n", GC_m2s (type));
2015 LOG (GNUNET_ERROR_TYPE_DEBUG, "type %s\n", GC_m2s (type));
2017 fwd = GCC_is_origin (c, GNUNET_YES);
2021 GNUNET_break (NULL == GCC_send_prebuilt_message (msg, type, mid, c, fwd,
2022 force, NULL, NULL));
2025 if (NULL == existing_q)
2027 tq = GNUNET_new (struct CadetTunnelQueue); /* FIXME valgrind: leak*/
2034 tq->cq = GCC_send_prebuilt_message (msg, type, mid, c, fwd, force,
2035 &tun_message_sent, tq);
2036 GNUNET_assert (NULL != tq->cq);
2038 tq->cont_cls = cont_cls;
2045 * Send all cached messages that we can, tunnel is online.
2047 * @param t Tunnel that holds the messages. Cannot be loopback.
2050 send_queued_data (struct CadetTunnel *t)
2052 struct CadetTunnelDelayed *tqd;
2053 struct CadetTunnelDelayed *next;
2056 LOG (GNUNET_ERROR_TYPE_INFO, "Send queued data, tunnel %s\n", GCT_2s (t));
2058 if (GCT_is_loopback (t))
2064 if (GNUNET_NO == is_ready (t))
2066 LOG (GNUNET_ERROR_TYPE_WARNING, " not ready yet: %s/%s\n",
2067 estate2s (t->estate), cstate2s (t->cstate));
2071 room = GCT_get_connections_buffer (t);
2072 LOG (GNUNET_ERROR_TYPE_DEBUG, " buffer space: %u\n", room);
2073 LOG (GNUNET_ERROR_TYPE_DEBUG, " tq head: %p\n", t->tq_head);
2074 for (tqd = t->tq_head; NULL != tqd && room > 0; tqd = next)
2076 LOG (GNUNET_ERROR_TYPE_DEBUG, " sending queued data\n");
2079 send_prebuilt_message ((struct GNUNET_MessageHeader *) &tqd[1],
2080 tqd->t, NULL, GNUNET_YES,
2081 NULL != tqd->tq ? tqd->tq->cont : NULL,
2082 NULL != tqd->tq ? tqd->tq->cont_cls : NULL,
2086 LOG (GNUNET_ERROR_TYPE_DEBUG, "GCT_send_queued_data end\n", GCP_2s (t->peer));
2091 * @brief Resend the AX KX until we complete the handshake.
2093 * @param cls Closure (tunnel).
2096 ax_kx_resend (void *cls)
2098 struct CadetTunnel *t = cls;
2100 t->rekey_task = NULL;
2101 if (CADET_TUNNEL_KEY_OK == t->estate)
2103 /* Should have been canceled on estate change */
2108 GCT_send_ax_kx (t, CADET_TUNNEL_KEY_SENT >= t->estate);
2113 * Callback called when a queued message is sent.
2115 * @param cls Closure.
2116 * @param c Connection this message was on.
2117 * @param type Type of message sent.
2118 * @param fwd Was this a FWD going message?
2119 * @param size Size of the message.
2122 ephm_sent (void *cls,
2123 struct CadetConnection *c,
2124 struct CadetConnectionQueue *q,
2125 uint16_t type, int fwd, size_t size)
2127 struct CadetTunnel *t = cls;
2128 LOG (GNUNET_ERROR_TYPE_DEBUG, "ephemeral sent %s\n", GC_m2s (type));
2132 if (CADET_TUNNEL_KEY_OK == t->estate)
2135 if (CADET_Axolotl == t->enc_type)
2137 if (NULL != t->rekey_task)
2140 GCT_debug (t, GNUNET_ERROR_TYPE_WARNING);
2141 GNUNET_SCHEDULER_cancel (t->rekey_task);
2143 t->rekey_task = GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_SECONDS,
2150 * Callback called when a queued message is sent.
2152 * @param cls Closure.
2153 * @param c Connection this message was on.
2154 * @param type Type of message sent.
2155 * @param fwd Was this a FWD going message?
2156 * @param size Size of the message.
2159 pong_sent (void *cls,
2160 struct CadetConnection *c,
2161 struct CadetConnectionQueue *q,
2162 uint16_t type, int fwd, size_t size)
2164 struct CadetTunnel *t = cls;
2165 LOG (GNUNET_ERROR_TYPE_DEBUG, "pong_sent %s\n", GC_m2s (type));
2172 * Sends key exchange message on a tunnel, choosing the best connection.
2173 * Should not be called on loopback tunnels.
2175 * @param t Tunnel on which this message is transmitted.
2176 * @param message Message to send. Function modifies it.
2178 * @return Handle to the message in the connection queue.
2180 static struct CadetConnectionQueue *
2181 send_kx (struct CadetTunnel *t,
2182 const struct GNUNET_MessageHeader *message)
2184 struct CadetConnection *c;
2185 struct GNUNET_CADET_KX *msg;
2186 size_t size = ntohs (message->size);
2187 char cbuf[sizeof (struct GNUNET_CADET_KX) + size];
2192 LOG (GNUNET_ERROR_TYPE_DEBUG, "GMT KX on Tunnel %s\n", GCT_2s (t));
2194 /* Avoid loopback. */
2195 if (GCT_is_loopback (t))
2200 type = ntohs (message->type);
2202 /* Even if tunnel is "being destroyed", send anyway.
2203 * Could be a response to a rekey initiated by remote peer,
2204 * who is trying to create a new channel!
2207 /* Must have a connection, or be looking for one. */
2208 if (NULL == t->connection_head)
2210 LOG (GNUNET_ERROR_TYPE_DEBUG, "%s with no connection\n", GC_m2s (type));
2211 if (CADET_TUNNEL_SEARCHING != t->cstate)
2214 GCT_debug (t, GNUNET_ERROR_TYPE_ERROR);
2215 GCP_debug (t->peer, GNUNET_ERROR_TYPE_ERROR);
2220 msg = (struct GNUNET_CADET_KX *) cbuf;
2221 msg->header.type = htons (GNUNET_MESSAGE_TYPE_CADET_KX);
2222 msg->header.size = htons (sizeof (struct GNUNET_CADET_KX) + size);
2223 c = tunnel_get_connection (t);
2226 if (NULL == t->destroy_task && CADET_TUNNEL_READY == t->cstate)
2229 GCT_debug (t, GNUNET_ERROR_TYPE_ERROR);
2235 case GNUNET_MESSAGE_TYPE_CADET_KX_EPHEMERAL:
2236 case GNUNET_MESSAGE_TYPE_CADET_AX_KX:
2237 GNUNET_assert (NULL == t->ephm_h);
2240 case GNUNET_MESSAGE_TYPE_CADET_KX_PONG:
2241 GNUNET_assert (NULL == t->pong_h);
2246 LOG (GNUNET_ERROR_TYPE_DEBUG, "unkown type %s\n", GC_m2s (type));
2249 memcpy (&msg[1], message, size);
2251 fwd = GCC_is_origin (c, GNUNET_YES);
2253 return GCC_send_prebuilt_message (&msg->header, type, 0, c,
2260 * Send the ephemeral key on a tunnel.
2262 * @param t Tunnel on which to send the key.
2265 send_ephemeral (struct CadetTunnel *t)
2267 LOG (GNUNET_ERROR_TYPE_INFO, "==> EPHM for %s\n", GCT_2s (t));
2268 if (NULL != t->ephm_h)
2270 LOG (GNUNET_ERROR_TYPE_INFO, " already queued\n");
2274 otr_kx_msg.sender_status = htonl (t->estate);
2275 otr_kx_msg.iv = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX);
2276 otr_kx_msg.nonce = t->kx_ctx->challenge;
2277 LOG (GNUNET_ERROR_TYPE_DEBUG, " send nonce c %u\n", otr_kx_msg.nonce);
2278 t_encrypt (t, &otr_kx_msg.nonce, &otr_kx_msg.nonce,
2279 ping_encryption_size(), otr_kx_msg.iv, GNUNET_YES);
2280 LOG (GNUNET_ERROR_TYPE_DEBUG, " send nonce e %u\n", otr_kx_msg.nonce);
2281 t->ephm_h = send_kx (t, &otr_kx_msg.header);
2286 * Send a pong message on a tunnel.
2288 * @param t Tunnel on which to send the pong.
2289 * @param challenge Value sent in the ping that we have to send back.
2292 send_pong (struct CadetTunnel *t, uint32_t challenge)
2294 struct GNUNET_CADET_KX_Pong msg;
2296 LOG (GNUNET_ERROR_TYPE_INFO, "==> PONG for %s\n", GCT_2s (t));
2297 if (NULL != t->pong_h)
2299 LOG (GNUNET_ERROR_TYPE_INFO, " already queued\n");
2302 msg.header.size = htons (sizeof (msg));
2303 msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_KX_PONG);
2304 msg.iv = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX);
2305 msg.nonce = challenge;
2306 LOG (GNUNET_ERROR_TYPE_DEBUG, " sending %u\n", msg.nonce);
2307 t_encrypt (t, &msg.nonce, &msg.nonce,
2308 sizeof (msg.nonce), msg.iv, GNUNET_YES);
2309 LOG (GNUNET_ERROR_TYPE_DEBUG, " e sending %u\n", msg.nonce);
2311 t->pong_h = send_kx (t, &msg.header);
2316 * Initiate a rekey with the remote peer.
2318 * @param cls Closure (tunnel).
2321 rekey_tunnel (void *cls)
2323 struct CadetTunnel *t = cls;
2325 t->rekey_task = NULL;
2326 LOG (GNUNET_ERROR_TYPE_INFO, "Re-key Tunnel %s\n", GCT_2s (t));
2327 GNUNET_assert (NULL != t->kx_ctx);
2328 struct GNUNET_TIME_Relative duration;
2330 duration = GNUNET_TIME_absolute_get_duration (t->kx_ctx->rekey_start_time);
2331 LOG (GNUNET_ERROR_TYPE_DEBUG,
2332 " kx started %s ago\n",
2333 GNUNET_STRINGS_relative_time_to_string (duration, GNUNET_YES));
2335 // FIXME make duration of old keys configurable
2336 if (duration.rel_value_us >= GNUNET_TIME_UNIT_MINUTES.rel_value_us)
2338 LOG (GNUNET_ERROR_TYPE_DEBUG, " deleting old keys\n");
2339 memset (&t->kx_ctx->d_key_old, 0, sizeof (t->kx_ctx->d_key_old));
2340 memset (&t->kx_ctx->e_key_old, 0, sizeof (t->kx_ctx->e_key_old));
2347 case CADET_TUNNEL_KEY_UNINITIALIZED:
2348 GCT_change_estate (t, CADET_TUNNEL_KEY_SENT);
2351 case CADET_TUNNEL_KEY_SENT:
2354 case CADET_TUNNEL_KEY_OK:
2356 * - state should have changed during rekey_iterator
2357 * - task should have been canceled at pong_handle
2360 GCT_change_estate (t, CADET_TUNNEL_KEY_REKEY);
2363 case CADET_TUNNEL_KEY_PING:
2364 case CADET_TUNNEL_KEY_REKEY:
2368 LOG (GNUNET_ERROR_TYPE_DEBUG, "Unexpected state %u\n", t->estate);
2371 // FIXME exponential backoff
2372 struct GNUNET_TIME_Relative delay;
2374 delay = GNUNET_TIME_relative_divide (rekey_period, 16);
2375 delay = GNUNET_TIME_relative_min (delay, REKEY_WAIT);
2376 LOG (GNUNET_ERROR_TYPE_DEBUG, " next call in %s\n",
2377 GNUNET_STRINGS_relative_time_to_string (delay, GNUNET_YES));
2378 t->rekey_task = GNUNET_SCHEDULER_add_delayed (delay, &rekey_tunnel, t);
2383 * Our ephemeral key has changed, create new session key on all tunnels.
2385 * Each tunnel will start the Key Exchange with a random delay between
2386 * 0 and number_of_tunnels*100 milliseconds, so there are 10 key exchanges
2387 * per second, on average.
2389 * @param cls Closure (size of the hashmap).
2390 * @param key Current public key.
2391 * @param value Value in the hash map (tunnel).
2393 * @return #GNUNET_YES, so we should continue to iterate,
2396 rekey_iterator (void *cls,
2397 const struct GNUNET_PeerIdentity *key,
2400 struct CadetTunnel *t = value;
2401 struct GNUNET_TIME_Relative delay;
2402 long n = (long) cls;
2405 if (NULL != t->rekey_task)
2408 if (GNUNET_YES == GCT_is_loopback (t))
2411 if (CADET_OTR != t->enc_type)
2414 r = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK, (uint32_t) n * 100);
2415 delay = GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MILLISECONDS, r);
2416 t->rekey_task = GNUNET_SCHEDULER_add_delayed (delay, &rekey_tunnel, t);
2417 if (GNUNET_OK == create_kx_ctx (t))
2418 GCT_change_estate (t, CADET_TUNNEL_KEY_REKEY);
2430 * Create a new ephemeral key and key message, schedule next rekeying.
2432 * @param cls Closure (unused).
2435 global_otr_rekey (void *cls)
2437 struct GNUNET_TIME_Absolute time;
2441 GNUNET_free_non_null (otr_ephemeral_key);
2442 otr_ephemeral_key = GNUNET_CRYPTO_ecdhe_key_create ();
2444 time = GNUNET_TIME_absolute_get ();
2445 otr_kx_msg.creation_time = GNUNET_TIME_absolute_hton (time);
2446 time = GNUNET_TIME_absolute_add (time, rekey_period);
2447 time = GNUNET_TIME_absolute_add (time, GNUNET_TIME_UNIT_MINUTES);
2448 otr_kx_msg.expiration_time = GNUNET_TIME_absolute_hton (time);
2449 GNUNET_CRYPTO_ecdhe_key_get_public (otr_ephemeral_key, &otr_kx_msg.ephemeral_key);
2450 LOG (GNUNET_ERROR_TYPE_INFO, "GLOBAL OTR RE-KEY, NEW EPHM: %s\n",
2451 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &otr_kx_msg.ephemeral_key));
2453 GNUNET_assert (GNUNET_OK ==
2454 GNUNET_CRYPTO_eddsa_sign (id_key,
2455 &otr_kx_msg.purpose,
2456 &otr_kx_msg.signature));
2458 n = (long) GNUNET_CONTAINER_multipeermap_size (tunnels);
2459 GNUNET_CONTAINER_multipeermap_iterate (tunnels, &rekey_iterator, (void *) n);
2461 rekey_task = GNUNET_SCHEDULER_add_delayed (rekey_period,
2462 &global_otr_rekey, NULL);
2467 * Called only on shutdown, destroy every tunnel.
2469 * @param cls Closure (unused).
2470 * @param key Current public key.
2471 * @param value Value in the hash map (tunnel).
2473 * @return #GNUNET_YES, so we should continue to iterate,
2476 destroy_iterator (void *cls,
2477 const struct GNUNET_PeerIdentity *key,
2480 struct CadetTunnel *t = value;
2482 LOG (GNUNET_ERROR_TYPE_DEBUG,
2483 "GCT_shutdown destroying tunnel at %p\n", t);
2490 * Notify remote peer that we don't know a channel he is talking about,
2491 * probably CHANNEL_DESTROY was missed.
2493 * @param t Tunnel on which to notify.
2494 * @param gid ID of the channel.
2497 send_channel_destroy (struct CadetTunnel *t, unsigned int gid)
2499 struct GNUNET_CADET_ChannelManage msg;
2501 msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_CHANNEL_DESTROY);
2502 msg.header.size = htons (sizeof (msg));
2503 msg.chid = htonl (gid);
2505 LOG (GNUNET_ERROR_TYPE_DEBUG,
2506 "WARNING destroying unknown channel %u on tunnel %s\n",
2508 send_prebuilt_message (&msg.header, t, NULL, GNUNET_YES, NULL, NULL, NULL);
2513 * Demultiplex data per channel and call appropriate channel handler.
2515 * @param t Tunnel on which the data came.
2516 * @param msg Data message.
2517 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
2518 * #GNUNET_YES if message is FWD on the respective channel (loopback)
2519 * #GNUNET_NO if message is BCK on the respective channel (loopback)
2520 * #GNUNET_SYSERR if message on a one-ended channel (remote)
2523 handle_data (struct CadetTunnel *t,
2524 const struct GNUNET_CADET_Data *msg,
2527 struct CadetChannel *ch;
2533 size = ntohs (msg->header.size);
2535 sizeof (struct GNUNET_CADET_Data) +
2536 sizeof (struct GNUNET_MessageHeader))
2541 type = ntohs (msg[1].header.type);
2542 LOG (GNUNET_ERROR_TYPE_DEBUG, " payload of type %s\n", GC_m2s (type));
2543 SPRINTF (buf, "# received payload of type %hu", type);
2544 GNUNET_STATISTICS_update (stats, buf, 1, GNUNET_NO);
2548 ch = GCT_get_channel (t, ntohl (msg->chid));
2551 GNUNET_STATISTICS_update (stats, "# data on unknown channel",
2553 LOG (GNUNET_ERROR_TYPE_DEBUG, "channel 0x%X unknown\n", ntohl (msg->chid));
2554 send_channel_destroy (t, ntohl (msg->chid));
2558 GCCH_handle_data (ch, msg, fwd);
2563 * Demultiplex data ACKs per channel and update appropriate channel buffer info.
2565 * @param t Tunnel on which the DATA ACK came.
2566 * @param msg DATA ACK message.
2567 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
2568 * #GNUNET_YES if message is FWD on the respective channel (loopback)
2569 * #GNUNET_NO if message is BCK on the respective channel (loopback)
2570 * #GNUNET_SYSERR if message on a one-ended channel (remote)
2573 handle_data_ack (struct CadetTunnel *t,
2574 const struct GNUNET_CADET_DataACK *msg,
2577 struct CadetChannel *ch;
2581 size = ntohs (msg->header.size);
2582 if (size != sizeof (struct GNUNET_CADET_DataACK))
2589 ch = GCT_get_channel (t, ntohl (msg->chid));
2592 GNUNET_STATISTICS_update (stats, "# data ack on unknown channel",
2594 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel %u unknown\n",
2599 GCCH_handle_data_ack (ch, msg, fwd);
2604 * Handle channel create.
2606 * @param t Tunnel on which the message came.
2607 * @param msg ChannelCreate message.
2610 handle_ch_create (struct CadetTunnel *t,
2611 const struct GNUNET_CADET_ChannelCreate *msg)
2613 struct CadetChannel *ch;
2617 size = ntohs (msg->header.size);
2618 if (size != sizeof (struct GNUNET_CADET_ChannelCreate))
2620 GNUNET_break_op (0);
2625 ch = GCT_get_channel (t, ntohl (msg->chid));
2626 if (NULL != ch && ! GCT_is_loopback (t))
2628 /* Probably a retransmission, safe to ignore */
2629 LOG (GNUNET_ERROR_TYPE_DEBUG, " already exists...\n");
2631 ch = GCCH_handle_create (t, msg);
2633 GCT_add_channel (t, ch);
2639 * Handle channel NACK: check correctness and call channel handler for NACKs.
2641 * @param t Tunnel on which the NACK came.
2642 * @param msg NACK message.
2645 handle_ch_nack (struct CadetTunnel *t,
2646 const struct GNUNET_CADET_ChannelManage *msg)
2648 struct CadetChannel *ch;
2652 size = ntohs (msg->header.size);
2653 if (size != sizeof (struct GNUNET_CADET_ChannelManage))
2660 ch = GCT_get_channel (t, ntohl (msg->chid));
2663 GNUNET_STATISTICS_update (stats, "# channel NACK on unknown channel",
2665 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel %u unknown\n",
2670 GCCH_handle_nack (ch);
2675 * Handle a CHANNEL ACK (SYNACK/ACK).
2677 * @param t Tunnel on which the CHANNEL ACK came.
2678 * @param msg CHANNEL ACK message.
2679 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
2680 * #GNUNET_YES if message is FWD on the respective channel (loopback)
2681 * #GNUNET_NO if message is BCK on the respective channel (loopback)
2682 * #GNUNET_SYSERR if message on a one-ended channel (remote)
2685 handle_ch_ack (struct CadetTunnel *t,
2686 const struct GNUNET_CADET_ChannelManage *msg,
2689 struct CadetChannel *ch;
2693 size = ntohs (msg->header.size);
2694 if (size != sizeof (struct GNUNET_CADET_ChannelManage))
2701 ch = GCT_get_channel (t, ntohl (msg->chid));
2704 GNUNET_STATISTICS_update (stats, "# channel ack on unknown channel",
2706 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel %u unknown\n",
2711 GCCH_handle_ack (ch, msg, fwd);
2716 * Handle a channel destruction message.
2718 * @param t Tunnel on which the message came.
2719 * @param msg Channel destroy message.
2720 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
2721 * #GNUNET_YES if message is FWD on the respective channel (loopback)
2722 * #GNUNET_NO if message is BCK on the respective channel (loopback)
2723 * #GNUNET_SYSERR if message on a one-ended channel (remote)
2726 handle_ch_destroy (struct CadetTunnel *t,
2727 const struct GNUNET_CADET_ChannelManage *msg,
2730 struct CadetChannel *ch;
2734 size = ntohs (msg->header.size);
2735 if (size != sizeof (struct GNUNET_CADET_ChannelManage))
2742 ch = GCT_get_channel (t, ntohl (msg->chid));
2745 /* Probably a retransmission, safe to ignore */
2749 GCCH_handle_destroy (ch, msg, fwd);
2754 * Free Axolotl data.
2759 destroy_ax (struct CadetTunnel *t)
2764 GNUNET_free_non_null (t->ax->DHRs);
2765 GNUNET_free_non_null (t->ax->kx_0);
2766 while (NULL != t->ax->skipped_head)
2767 delete_skipped_key (t, t->ax->skipped_head);
2768 GNUNET_assert (0 == t->ax->skipped);
2770 GNUNET_free (t->ax);
2773 if (NULL != t->rekey_task)
2775 GNUNET_SCHEDULER_cancel (t->rekey_task);
2776 t->rekey_task = NULL;
2778 if (NULL != t->ephm_h)
2780 GCC_cancel (t->ephm_h);
2787 * The peer's ephemeral key has changed: update the symmetrical keys.
2789 * @param t Tunnel this message came on.
2790 * @param msg Key eXchange message.
2793 handle_ephemeral (struct CadetTunnel *t,
2794 const struct GNUNET_CADET_KX_Ephemeral *msg)
2796 LOG (GNUNET_ERROR_TYPE_INFO, "<== EPHM for %s\n", GCT_2s (t));
2798 /* Some old versions are still around, don't log as error. */
2799 if (GNUNET_OK != check_ephemeral (t, msg))
2802 /* If we get a proper OTR-style ephemeral, fallback to old crypto. */
2806 t->enc_type = CADET_OTR;
2807 if (NULL != t->rekey_task)
2808 GNUNET_SCHEDULER_cancel (t->rekey_task);
2809 if (GNUNET_OK != create_kx_ctx (t))
2816 GNUNET_STATISTICS_update (stats, "# otr-downgrades", -1, GNUNET_NO);
2820 * If the key is different from what we know, derive the new E/D keys.
2821 * Else destroy the rekey ctx (duplicate EPHM after successful KX).
2823 if (0 != memcmp (&t->peers_ephemeral_key, &msg->ephemeral_key,
2824 sizeof (msg->ephemeral_key)))
2826 #if DUMP_KEYS_TO_STDERR
2827 LOG (GNUNET_ERROR_TYPE_INFO, "OLD: %s\n",
2828 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &t->peers_ephemeral_key));
2829 LOG (GNUNET_ERROR_TYPE_INFO, "NEW: %s\n",
2830 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &msg->ephemeral_key));
2832 t->peers_ephemeral_key = msg->ephemeral_key;
2834 if (GNUNET_OK != create_kx_ctx (t))
2841 if (CADET_TUNNEL_KEY_OK == t->estate)
2843 GCT_change_estate (t, CADET_TUNNEL_KEY_REKEY);
2845 if (NULL != t->rekey_task)
2846 GNUNET_SCHEDULER_cancel (t->rekey_task);
2847 t->rekey_task = GNUNET_SCHEDULER_add_now (&rekey_tunnel, t);
2849 if (CADET_TUNNEL_KEY_SENT == t->estate)
2851 LOG (GNUNET_ERROR_TYPE_DEBUG, " our key was sent, sending challenge\n");
2853 GCT_change_estate (t, CADET_TUNNEL_KEY_PING);
2856 if (CADET_TUNNEL_KEY_UNINITIALIZED != ntohl(msg->sender_status))
2860 LOG (GNUNET_ERROR_TYPE_DEBUG, " recv nonce e %u\n", msg->nonce);
2861 t_decrypt (t, &nonce, &msg->nonce, ping_encryption_size (), msg->iv);
2862 LOG (GNUNET_ERROR_TYPE_DEBUG, " recv nonce c %u\n", nonce);
2863 send_pong (t, nonce);
2869 * Peer has answer to our challenge.
2870 * If answer is successful, consider the key exchange finished and clean
2871 * up all related state.
2873 * @param t Tunnel this message came on.
2874 * @param msg Key eXchange Pong message.
2877 handle_pong (struct CadetTunnel *t,
2878 const struct GNUNET_CADET_KX_Pong *msg)
2882 LOG (GNUNET_ERROR_TYPE_INFO, "<== PONG for %s\n", GCT_2s (t));
2883 if (NULL == t->rekey_task)
2885 GNUNET_STATISTICS_update (stats, "# duplicate PONG messages", 1, GNUNET_NO);
2888 if (NULL == t->kx_ctx)
2890 GNUNET_STATISTICS_update (stats, "# stray PONG messages", 1, GNUNET_NO);
2894 t_decrypt (t, &challenge, &msg->nonce, sizeof (uint32_t), msg->iv);
2895 if (challenge != t->kx_ctx->challenge)
2897 LOG (GNUNET_ERROR_TYPE_WARNING, "Wrong PONG challenge on %s\n", GCT_2s (t));
2898 LOG (GNUNET_ERROR_TYPE_DEBUG, "PONG: %u (e: %u). Expected: %u.\n",
2899 challenge, msg->nonce, t->kx_ctx->challenge);
2903 GNUNET_SCHEDULER_cancel (t->rekey_task);
2904 t->rekey_task = NULL;
2906 /* Don't free the old keys right away, but after a delay.
2907 * Rationale: the KX could have happened over a very fast connection,
2908 * with payload traffic still signed with the old key stuck in a slower
2910 * Don't keep the keys longer than 1/4 the rekey period, and no longer than
2914 GCT_change_estate (t, CADET_TUNNEL_KEY_OK);
2919 * Handle Axolotl handshake.
2921 * @param t Tunnel this message came on.
2922 * @param msg Key eXchange Pong message.
2925 handle_kx_ax (struct CadetTunnel *t, const struct GNUNET_CADET_AX_KX *msg)
2927 struct CadetTunnelAxolotl *ax;
2928 struct GNUNET_HashCode key_material[3];
2929 struct GNUNET_CRYPTO_SymmetricSessionKey keys[5];
2930 const char salt[] = "CADET Axolotl salt";
2931 const struct GNUNET_PeerIdentity *pid;
2934 LOG (GNUNET_ERROR_TYPE_INFO, "<== { AX_KX} on %s\n", GCT_2s (t));
2938 /* Something is wrong if ax is NULL. Whose fault it is? */
2939 GNUNET_break_op (CADET_OTR == t->enc_type);
2940 GNUNET_break (CADET_Axolotl == t->enc_type);
2945 pid = GCT_get_destination (t);
2946 if (0 > GNUNET_CRYPTO_cmp_peer_identity (&my_full_id, pid))
2947 am_I_alice = GNUNET_YES;
2948 else if (0 < GNUNET_CRYPTO_cmp_peer_identity (&my_full_id, pid))
2949 am_I_alice = GNUNET_NO;
2952 GNUNET_break_op (0);
2956 if (0 != (GNUNET_CADET_AX_KX_FLAG_FORCE_REPLY & ntohl (msg->flags)))
2958 if (NULL != t->rekey_task)
2960 GNUNET_SCHEDULER_cancel (t->rekey_task);
2961 t->rekey_task = NULL;
2963 GCT_send_ax_kx (t, GNUNET_NO);
2966 if (0 == memcmp (&ax->DHRr, &msg->ratchet_key, sizeof(msg->ratchet_key)))
2968 LOG (GNUNET_ERROR_TYPE_INFO, " known ratchet key, exit\n");
2972 LOG (GNUNET_ERROR_TYPE_INFO, " is Alice? %s\n", am_I_alice ? "YES" : "NO");
2974 ax->DHRr = msg->ratchet_key;
2977 if (GNUNET_YES == am_I_alice)
2979 GNUNET_CRYPTO_eddsa_ecdh (id_key, /* A */
2980 &msg->ephemeral_key, /* B0 */
2985 GNUNET_CRYPTO_ecdh_eddsa (ax->kx_0, /* B0 */
2986 &pid->public_key, /* A */
2991 if (GNUNET_YES == am_I_alice)
2993 GNUNET_CRYPTO_ecdh_eddsa (ax->kx_0, /* A0 */
2994 &pid->public_key, /* B */
2999 GNUNET_CRYPTO_eddsa_ecdh (id_key, /* A */
3000 &msg->ephemeral_key, /* B0 */
3007 /* (This is the triple-DH, we could probably safely skip this,
3008 as A0/B0 are already in the key material.) */
3009 GNUNET_CRYPTO_ecc_ecdh (ax->kx_0, /* A0 or B0 */
3010 &msg->ephemeral_key, /* B0 or A0 */
3013 #if DUMP_KEYS_TO_STDERR
3016 for (i = 0; i < 3; i++)
3017 LOG (GNUNET_ERROR_TYPE_INFO, "km[%u]: %s\n",
3018 i, GNUNET_h2s (&key_material[i]));
3023 GNUNET_CRYPTO_kdf (keys, sizeof (keys),
3024 salt, sizeof (salt),
3025 &key_material, sizeof (key_material), NULL);
3027 if (0 == memcmp (&ax->RK, &keys[0], sizeof(ax->RK)))
3029 LOG (GNUNET_ERROR_TYPE_INFO, " known handshake key, exit\n");
3033 if (GNUNET_YES == am_I_alice)
3039 ax->ratchet_flag = GNUNET_YES;
3047 ax->ratchet_flag = GNUNET_NO;
3048 ax->ratchet_allowed = GNUNET_NO;
3049 ax->ratchet_counter = 0;
3050 ax->ratchet_expiration =
3051 GNUNET_TIME_absolute_add (GNUNET_TIME_absolute_get(), ratchet_time);
3056 GCT_change_estate (t, CADET_TUNNEL_KEY_PING);
3057 send_queued_data (t);
3062 * Demultiplex by message type and call appropriate handler for a message
3063 * towards a channel of a local tunnel.
3065 * @param t Tunnel this message came on.
3066 * @param msgh Message header.
3067 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
3068 * #GNUNET_YES if message is FWD on the respective channel (loopback)
3069 * #GNUNET_NO if message is BCK on the respective channel (loopback)
3070 * #GNUNET_SYSERR if message on a one-ended channel (remote)
3073 handle_decrypted (struct CadetTunnel *t,
3074 const struct GNUNET_MessageHeader *msgh,
3080 type = ntohs (msgh->type);
3081 LOG (GNUNET_ERROR_TYPE_DEBUG, "<-- %s on %s\n", GC_m2s (type), GCT_2s (t));
3082 SPRINTF (buf, "# received encrypted of type %hu (%s)", type, GC_m2s (type));
3083 GNUNET_STATISTICS_update (stats, buf, 1, GNUNET_NO);
3087 case GNUNET_MESSAGE_TYPE_CADET_KEEPALIVE:
3088 /* Do nothing, connection aleady got updated. */
3089 GNUNET_STATISTICS_update (stats, "# keepalives received", 1, GNUNET_NO);
3092 case GNUNET_MESSAGE_TYPE_CADET_DATA:
3093 /* Don't send hop ACK, wait for client to ACK */
3094 handle_data (t, (struct GNUNET_CADET_Data *) msgh, fwd);
3097 case GNUNET_MESSAGE_TYPE_CADET_DATA_ACK:
3098 handle_data_ack (t, (struct GNUNET_CADET_DataACK *) msgh, fwd);
3101 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_CREATE:
3102 handle_ch_create (t, (struct GNUNET_CADET_ChannelCreate *) msgh);
3105 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_NACK:
3106 handle_ch_nack (t, (struct GNUNET_CADET_ChannelManage *) msgh);
3109 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_ACK:
3110 handle_ch_ack (t, (struct GNUNET_CADET_ChannelManage *) msgh, fwd);
3113 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_DESTROY:
3114 handle_ch_destroy (t, (struct GNUNET_CADET_ChannelManage *) msgh, fwd);
3118 GNUNET_break_op (0);
3119 LOG (GNUNET_ERROR_TYPE_WARNING,
3120 "end-to-end message not known (%u)\n",
3121 ntohs (msgh->type));
3122 GCT_debug (t, GNUNET_ERROR_TYPE_WARNING);
3127 /******************************************************************************/
3128 /******************************** API ***********************************/
3129 /******************************************************************************/
3131 * Decrypt old format and demultiplex by message type. Call appropriate handler
3132 * for a message towards a channel of a local tunnel.
3134 * @param t Tunnel this message came on.
3135 * @param msg Message header.
3138 GCT_handle_encrypted (struct CadetTunnel *t,
3139 const struct GNUNET_MessageHeader *msg)
3141 uint16_t size = ntohs (msg->size);
3145 const struct GNUNET_MessageHeader *msgh;
3148 type = ntohs (msg->type);
3151 case GNUNET_MESSAGE_TYPE_CADET_ENCRYPTED:
3153 const struct GNUNET_CADET_Encrypted *emsg;
3154 size_t payload_size;
3156 GNUNET_STATISTICS_update (stats, "# received OTR", 1, GNUNET_NO);
3157 emsg = (const struct GNUNET_CADET_Encrypted *) msg;
3158 payload_size = size - sizeof (struct GNUNET_CADET_Encrypted);
3159 decrypted_size = t_decrypt_and_validate (t, cbuf, &emsg[1], payload_size,
3160 emsg->iv, &emsg->hmac);
3163 case GNUNET_MESSAGE_TYPE_CADET_AX:
3165 const struct GNUNET_CADET_AX *emsg;
3167 GNUNET_STATISTICS_update (stats, "# received Axolotl", 1, GNUNET_NO);
3168 emsg = (const struct GNUNET_CADET_AX *) msg;
3169 decrypted_size = t_ax_decrypt_and_validate (t, cbuf, emsg, size);
3173 GNUNET_break_op (0);
3177 if (-1 == decrypted_size)
3179 GNUNET_break_op (0);
3180 GNUNET_STATISTICS_update (stats, "# unable to decrypt", 1, GNUNET_NO);
3181 LOG (GNUNET_ERROR_TYPE_WARNING, "Wrong crypto on tunnel %s\n", GCT_2s (t));
3182 GCT_debug (t, GNUNET_ERROR_TYPE_WARNING);
3185 GCT_change_estate (t, CADET_TUNNEL_KEY_OK);
3187 /* FIXME: this is bad, as the structs returned from
3188 this loop may be unaligned, see util's MST for
3189 how to do this right. */
3191 while (off + sizeof (struct GNUNET_MessageHeader) <= decrypted_size)
3195 msgh = (const struct GNUNET_MessageHeader *) &cbuf[off];
3196 msize = ntohs (msgh->size);
3197 if (msize < sizeof (struct GNUNET_MessageHeader))
3199 GNUNET_break_op (0);
3202 if (off + msize < decrypted_size)
3204 GNUNET_break_op (0);
3207 handle_decrypted (t, msgh, GNUNET_SYSERR);
3214 * Demultiplex an encapsulated KX message by message type.
3216 * @param t Tunnel on which the message came.
3217 * @param message Payload of KX message.
3220 GCT_handle_kx (struct CadetTunnel *t,
3221 const struct GNUNET_MessageHeader *message)
3226 type = ntohs (message->type);
3227 LOG (GNUNET_ERROR_TYPE_DEBUG, "kx message received: %s\n", GC_m2s (type));
3228 sprintf (buf, "# received KX of type %hu (%s)", type, GC_m2s (type));
3229 GNUNET_STATISTICS_update (stats, buf, 1, GNUNET_NO);
3232 case GNUNET_MESSAGE_TYPE_CADET_KX_EPHEMERAL:
3233 handle_ephemeral (t, (const struct GNUNET_CADET_KX_Ephemeral *) message);
3236 case GNUNET_MESSAGE_TYPE_CADET_KX_PONG:
3237 handle_pong (t, (const struct GNUNET_CADET_KX_Pong *) message);
3240 case GNUNET_MESSAGE_TYPE_CADET_AX_KX:
3241 handle_kx_ax (t, (const struct GNUNET_CADET_AX_KX *) message);
3245 GNUNET_break_op (0);
3246 LOG (GNUNET_ERROR_TYPE_WARNING, "kx message %s unknown\n", GC_m2s (type));
3251 * Initialize the tunnel subsystem.
3253 * @param c Configuration handle.
3254 * @param key ECC private key, to derive all other keys and do crypto.
3257 GCT_init (const struct GNUNET_CONFIGURATION_Handle *c,
3258 const struct GNUNET_CRYPTO_EddsaPrivateKey *key)
3260 int expected_overhead;
3262 LOG (GNUNET_ERROR_TYPE_DEBUG, "init\n");
3264 expected_overhead = 0;
3265 expected_overhead += sizeof (struct GNUNET_CADET_Encrypted);
3266 expected_overhead += sizeof (struct GNUNET_CADET_Data);
3267 expected_overhead += sizeof (struct GNUNET_CADET_ACK);
3268 GNUNET_assert (GNUNET_CONSTANTS_CADET_P2P_OVERHEAD == expected_overhead);
3271 GNUNET_CONFIGURATION_get_value_number (c, "CADET", "DEFAULT_TTL",
3274 GNUNET_log_config_invalid (GNUNET_ERROR_TYPE_DEBUG,
3275 "CADET", "DEFAULT_TTL", "USING DEFAULT");
3279 GNUNET_CONFIGURATION_get_value_time (c, "CADET", "REKEY_PERIOD",
3282 rekey_period = GNUNET_TIME_UNIT_DAYS;
3285 GNUNET_CONFIGURATION_get_value_number (c, "CADET", "RATCHET_MESSAGES",
3288 GNUNET_log_config_invalid (GNUNET_ERROR_TYPE_WARNING,
3289 "CADET", "RATCHET_MESSAGES", "USING DEFAULT");
3290 ratchet_messages = 64;
3293 GNUNET_CONFIGURATION_get_value_time (c, "CADET", "RATCHET_TIME",
3296 GNUNET_log_config_invalid (GNUNET_ERROR_TYPE_WARNING,
3297 "CADET", "RATCHET_TIME", "USING DEFAULT");
3298 ratchet_time = GNUNET_TIME_UNIT_HOURS;
3304 otr_kx_msg.header.size = htons (sizeof (otr_kx_msg));
3305 otr_kx_msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_KX_EPHEMERAL);
3306 otr_kx_msg.purpose.purpose = htonl (GNUNET_SIGNATURE_PURPOSE_CADET_KX);
3307 otr_kx_msg.purpose.size = htonl (ephemeral_purpose_size ());
3308 otr_kx_msg.origin_identity = my_full_id;
3309 rekey_task = GNUNET_SCHEDULER_add_now (&global_otr_rekey, NULL);
3310 tunnels = GNUNET_CONTAINER_multipeermap_create (128, GNUNET_YES);
3315 * Shut down the tunnel subsystem.
3320 LOG (GNUNET_ERROR_TYPE_DEBUG, "Shutting down tunnels\n");
3321 if (NULL != rekey_task)
3323 GNUNET_SCHEDULER_cancel (rekey_task);
3326 GNUNET_CONTAINER_multipeermap_iterate (tunnels, &destroy_iterator, NULL);
3327 GNUNET_CONTAINER_multipeermap_destroy (tunnels);
3334 * @param destination Peer this tunnel is towards.
3336 struct CadetTunnel *
3337 GCT_new (struct CadetPeer *destination)
3339 struct CadetTunnel *t;
3341 t = GNUNET_new (struct CadetTunnel);
3343 t->peer = destination;
3346 GNUNET_CONTAINER_multipeermap_put (tunnels, GCP_get_id (destination), t,
3347 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_FAST))
3353 t->ax = GNUNET_new (struct CadetTunnelAxolotl);
3355 t->ax->kx_0 = GNUNET_CRYPTO_ecdhe_key_create ();
3361 * Change the tunnel's connection state.
3363 * @param t Tunnel whose connection state to change.
3364 * @param cstate New connection state.
3367 GCT_change_cstate (struct CadetTunnel* t, enum CadetTunnelCState cstate)
3371 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel %s cstate %s => %s\n",
3372 GCP_2s (t->peer), cstate2s (t->cstate), cstate2s (cstate));
3373 if (myid != GCP_get_short_id (t->peer) &&
3374 CADET_TUNNEL_READY != t->cstate &&
3375 CADET_TUNNEL_READY == cstate)
3378 if (CADET_TUNNEL_KEY_OK == t->estate)
3380 LOG (GNUNET_ERROR_TYPE_DEBUG, " cstate triggered send queued data\n");
3381 send_queued_data (t);
3383 else if (CADET_TUNNEL_KEY_UNINITIALIZED == t->estate)
3385 LOG (GNUNET_ERROR_TYPE_DEBUG, " cstate triggered kx\n");
3386 GCT_send_ax_kx (t, GNUNET_NO);
3390 LOG (GNUNET_ERROR_TYPE_DEBUG, "estate %s\n", estate2s (t->estate));
3395 if (CADET_TUNNEL_READY == cstate
3396 && CONNECTIONS_PER_TUNNEL <= GCT_count_connections (t))
3398 LOG (GNUNET_ERROR_TYPE_DEBUG, " cstate triggered stop dht\n");
3399 GCP_stop_search (t->peer);
3405 * Change the tunnel encryption state.
3407 * If the encryption state changes to OK, stop the rekey task.
3409 * @param t Tunnel whose encryption state to change, or NULL.
3410 * @param state New encryption state.
3413 GCT_change_estate (struct CadetTunnel* t, enum CadetTunnelEState state)
3415 enum CadetTunnelEState old;
3422 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel %s estate was %s\n",
3423 GCP_2s (t->peer), estate2s (old));
3424 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel %s estate is now %s\n",
3425 GCP_2s (t->peer), estate2s (t->estate));
3427 if (CADET_TUNNEL_KEY_OK != old && CADET_TUNNEL_KEY_OK == t->estate)
3429 if (NULL != t->rekey_task)
3431 GNUNET_SCHEDULER_cancel (t->rekey_task);
3432 t->rekey_task = NULL;
3434 /* Send queued data if tunnel is not loopback */
3435 if (myid != GCP_get_short_id (t->peer))
3436 send_queued_data (t);
3442 * @brief Check if tunnel has too many connections, and remove one if necessary.
3444 * Currently this means the newest connection, unless it is a direct one.
3445 * Implemented as a task to avoid freeing a connection that is in the middle
3446 * of being created/processed.
3448 * @param cls Closure (Tunnel to check).
3451 trim_connections (void *cls)
3453 struct CadetTunnel *t = cls;
3455 t->trim_connections_task = NULL;
3456 if (GCT_count_connections (t) > 2 * CONNECTIONS_PER_TUNNEL)
3458 struct CadetTConnection *iter;
3459 struct CadetTConnection *c;
3461 for (c = iter = t->connection_head; NULL != iter; iter = iter->next)
3463 if ((iter->created.abs_value_us > c->created.abs_value_us)
3464 && GNUNET_NO == GCC_is_direct (iter->c))
3471 LOG (GNUNET_ERROR_TYPE_DEBUG, "Too many connections on tunnel %s\n",
3473 LOG (GNUNET_ERROR_TYPE_DEBUG, "Destroying connection %s\n",
3486 * Add a connection to a tunnel.
3489 * @param c Connection.
3492 GCT_add_connection (struct CadetTunnel *t, struct CadetConnection *c)
3494 struct CadetTConnection *aux;
3496 GNUNET_assert (NULL != c);
3498 LOG (GNUNET_ERROR_TYPE_DEBUG, "add connection %s\n", GCC_2s (c));
3499 LOG (GNUNET_ERROR_TYPE_DEBUG, " to tunnel %s\n", GCT_2s (t));
3500 for (aux = t->connection_head; aux != NULL; aux = aux->next)
3504 aux = GNUNET_new (struct CadetTConnection);
3506 aux->created = GNUNET_TIME_absolute_get ();
3508 GNUNET_CONTAINER_DLL_insert (t->connection_head, t->connection_tail, aux);
3510 if (CADET_TUNNEL_SEARCHING == t->cstate)
3511 GCT_change_cstate (t, CADET_TUNNEL_WAITING);
3513 if (NULL != t->trim_connections_task)
3514 t->trim_connections_task = GNUNET_SCHEDULER_add_now (&trim_connections, t);
3519 * Remove a connection from a tunnel.
3522 * @param c Connection.
3525 GCT_remove_connection (struct CadetTunnel *t,
3526 struct CadetConnection *c)
3528 struct CadetTConnection *aux;
3529 struct CadetTConnection *next;
3532 LOG (GNUNET_ERROR_TYPE_DEBUG, "Removing connection %s from tunnel %s\n",
3533 GCC_2s (c), GCT_2s (t));
3534 for (aux = t->connection_head; aux != NULL; aux = next)
3539 GNUNET_CONTAINER_DLL_remove (t->connection_head, t->connection_tail, aux);
3544 conns = GCT_count_connections (t);
3546 && NULL == t->destroy_task
3547 && CADET_TUNNEL_SHUTDOWN != t->cstate
3548 && GNUNET_NO == shutting_down)
3550 if (0 == GCT_count_any_connections (t))
3551 GCT_change_cstate (t, CADET_TUNNEL_SEARCHING);
3553 GCT_change_cstate (t, CADET_TUNNEL_WAITING);
3556 /* Start new connections if needed */
3557 if (CONNECTIONS_PER_TUNNEL > conns
3558 && CADET_TUNNEL_SHUTDOWN != t->cstate
3559 && GNUNET_NO == shutting_down)
3561 LOG (GNUNET_ERROR_TYPE_DEBUG, " too few connections, getting new ones\n");
3562 GCP_connect (t->peer); /* Will change cstate to WAITING when possible */
3566 /* If not marked as ready, no change is needed */
3567 if (CADET_TUNNEL_READY != t->cstate)
3570 /* Check if any connection is ready to maintain cstate */
3571 for (aux = t->connection_head; aux != NULL; aux = aux->next)
3572 if (CADET_CONNECTION_READY == GCC_get_state (aux->c))
3578 * Add a channel to a tunnel.
3581 * @param ch Channel.
3584 GCT_add_channel (struct CadetTunnel *t, struct CadetChannel *ch)
3586 struct CadetTChannel *aux;
3588 GNUNET_assert (NULL != ch);
3590 LOG (GNUNET_ERROR_TYPE_DEBUG, "Adding channel %p to tunnel %p\n", ch, t);
3592 for (aux = t->channel_head; aux != NULL; aux = aux->next)
3594 LOG (GNUNET_ERROR_TYPE_DEBUG, " already there %p\n", aux->ch);
3599 aux = GNUNET_new (struct CadetTChannel);
3601 LOG (GNUNET_ERROR_TYPE_DEBUG,
3602 " adding %p to %p\n", aux, t->channel_head);
3603 GNUNET_CONTAINER_DLL_insert_tail (t->channel_head,
3607 if (NULL != t->destroy_task)
3609 GNUNET_SCHEDULER_cancel (t->destroy_task);
3610 t->destroy_task = NULL;
3611 LOG (GNUNET_ERROR_TYPE_DEBUG, " undo destroy!\n");
3617 * Remove a channel from a tunnel.
3620 * @param ch Channel.
3623 GCT_remove_channel (struct CadetTunnel *t, struct CadetChannel *ch)
3625 struct CadetTChannel *aux;
3627 LOG (GNUNET_ERROR_TYPE_DEBUG, "Removing channel %p from tunnel %p\n", ch, t);
3628 for (aux = t->channel_head; aux != NULL; aux = aux->next)
3632 LOG (GNUNET_ERROR_TYPE_DEBUG, " found! %s\n", GCCH_2s (ch));
3633 GNUNET_CONTAINER_DLL_remove (t->channel_head,
3644 * Search for a channel by global ID.
3646 * @param t Tunnel containing the channel.
3647 * @param chid Public channel number.
3649 * @return channel handler, NULL if doesn't exist
3651 struct CadetChannel *
3652 GCT_get_channel (struct CadetTunnel *t, CADET_ChannelNumber chid)
3654 struct CadetTChannel *iter;
3659 for (iter = t->channel_head; NULL != iter; iter = iter->next)
3661 if (GCCH_get_id (iter->ch) == chid)
3665 return NULL == iter ? NULL : iter->ch;
3670 * @brief Destroy a tunnel and free all resources.
3672 * Should only be called a while after the tunnel has been marked as destroyed,
3673 * in case there is a new channel added to the same peer shortly after marking
3674 * the tunnel. This way we avoid a new public key handshake.
3676 * @param cls Closure (tunnel to destroy).
3679 delayed_destroy (void *cls)
3681 struct CadetTunnel *t = cls;
3682 struct CadetTConnection *iter;
3684 t->destroy_task = NULL;
3685 LOG (GNUNET_ERROR_TYPE_DEBUG,
3686 "delayed destroying tunnel %p\n",
3688 t->cstate = CADET_TUNNEL_SHUTDOWN;
3689 for (iter = t->connection_head; NULL != iter; iter = iter->next)
3691 GCC_send_destroy (iter->c);
3698 * Tunnel is empty: destroy it.
3700 * Notifies all connections about the destruction.
3702 * @param t Tunnel to destroy.
3705 GCT_destroy_empty (struct CadetTunnel *t)
3707 if (GNUNET_YES == shutting_down)
3708 return; /* Will be destroyed immediately anyway */
3710 if (NULL != t->destroy_task)
3712 LOG (GNUNET_ERROR_TYPE_WARNING,
3713 "Tunnel %s is already scheduled for destruction. Tunnel debug dump:\n",
3715 GCT_debug (t, GNUNET_ERROR_TYPE_WARNING);
3717 /* should never happen, tunnel can only become empty once, and the
3718 * task identifier should be NO_TASK (cleaned when the tunnel was created
3719 * or became un-empty)
3724 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel %s empty: scheduling destruction\n",
3727 // FIXME make delay a config option
3728 t->destroy_task = GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_MINUTES,
3729 &delayed_destroy, t);
3730 LOG (GNUNET_ERROR_TYPE_DEBUG, "Scheduled destroy of %p as %p\n",
3731 t, t->destroy_task);
3736 * Destroy tunnel if empty (no more channels).
3738 * @param t Tunnel to destroy if empty.
3741 GCT_destroy_if_empty (struct CadetTunnel *t)
3743 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel %s destroy if empty\n", GCT_2s (t));
3744 if (0 < GCT_count_channels (t))
3747 GCT_destroy_empty (t);
3752 * Destroy the tunnel.
3754 * This function does not generate any warning traffic to clients or peers.
3757 * Cancel messages belonging to this tunnel queued to neighbors.
3758 * Free any allocated resources linked to the tunnel.
3760 * @param t The tunnel to destroy.
3763 GCT_destroy (struct CadetTunnel *t)
3765 struct CadetTConnection *iter_c;
3766 struct CadetTConnection *next_c;
3767 struct CadetTChannel *iter_ch;
3768 struct CadetTChannel *next_ch;
3769 unsigned int keepalives_queued;
3774 LOG (GNUNET_ERROR_TYPE_DEBUG,
3775 "destroying tunnel %s\n",
3777 GNUNET_break (GNUNET_YES ==
3778 GNUNET_CONTAINER_multipeermap_remove (tunnels,
3779 GCP_get_id (t->peer), t));
3781 for (iter_c = t->connection_head; NULL != iter_c; iter_c = next_c)
3783 next_c = iter_c->next;
3784 GCC_destroy (iter_c->c);
3786 for (iter_ch = t->channel_head; NULL != iter_ch; iter_ch = next_ch)
3788 next_ch = iter_ch->next;
3789 GCCH_destroy (iter_ch->ch);
3790 /* Should only happen on shutdown, but it's ok. */
3792 keepalives_queued = 0;
3793 while (NULL != t->tq_head)
3795 /* Should have been cleaned by destuction of channel. */
3796 struct GNUNET_MessageHeader *mh;
3799 mh = (struct GNUNET_MessageHeader *) &t->tq_head[1];
3800 type = ntohs (mh->type);
3801 if (0 == keepalives_queued && GNUNET_MESSAGE_TYPE_CADET_KEEPALIVE == type)
3803 keepalives_queued = 1;
3804 LOG (GNUNET_ERROR_TYPE_DEBUG,
3805 "one keepalive left behind on tunnel shutdown\n");
3807 else if (GNUNET_MESSAGE_TYPE_CADET_CHANNEL_DESTROY == type)
3809 LOG (GNUNET_ERROR_TYPE_WARNING,
3810 "tunnel destroyed before a CHANNEL_DESTROY was sent to peer\n");
3815 LOG (GNUNET_ERROR_TYPE_ERROR,
3816 "message left behind on tunnel shutdown: %s\n",
3819 unqueue_data (t->tq_head);
3823 if (NULL != t->destroy_task)
3825 LOG (GNUNET_ERROR_TYPE_DEBUG,
3826 "cancelling dest: %p\n",
3828 GNUNET_SCHEDULER_cancel (t->destroy_task);
3829 t->destroy_task = NULL;
3832 if (NULL != t->trim_connections_task)
3834 LOG (GNUNET_ERROR_TYPE_DEBUG, "cancelling trim: %p\n",
3835 t->trim_connections_task);
3836 GNUNET_SCHEDULER_cancel (t->trim_connections_task);
3837 t->trim_connections_task = NULL;
3840 GNUNET_STATISTICS_update (stats, "# tunnels", -1, GNUNET_NO);
3841 GCP_set_tunnel (t->peer, NULL);
3843 if (NULL != t->rekey_task)
3845 GNUNET_SCHEDULER_cancel (t->rekey_task);
3846 t->rekey_task = NULL;
3848 if (NULL != t->kx_ctx)
3850 if (NULL != t->kx_ctx->finish_task)
3851 GNUNET_SCHEDULER_cancel (t->kx_ctx->finish_task);
3852 GNUNET_free (t->kx_ctx);
3863 * @brief Use the given path for the tunnel.
3864 * Update the next and prev hops (and RCs).
3865 * (Re)start the path refresh in case the tunnel is locally owned.
3867 * @param t Tunnel to update.
3868 * @param p Path to use.
3870 * @return Connection created.
3872 struct CadetConnection *
3873 GCT_use_path (struct CadetTunnel *t, struct CadetPeerPath *path)
3875 struct CadetConnection *c;
3876 struct GNUNET_CADET_Hash cid;
3877 unsigned int own_pos;
3879 if (NULL == t || NULL == path)
3885 if (CADET_TUNNEL_SHUTDOWN == t->cstate)
3891 for (own_pos = 0; own_pos < path->length; own_pos++)
3893 if (path->peers[own_pos] == myid)
3896 if (own_pos >= path->length)
3898 GNUNET_break_op (0);
3902 GNUNET_CRYPTO_random_block (GNUNET_CRYPTO_QUALITY_NONCE, &cid, sizeof (cid));
3903 c = GCC_new (&cid, t, path, own_pos);
3906 /* Path was flawed */
3909 GCT_add_connection (t, c);
3915 * Count all created connections of a tunnel. Not necessarily ready connections!
3917 * @param t Tunnel on which to count.
3919 * @return Number of connections created, either being established or ready.
3922 GCT_count_any_connections (struct CadetTunnel *t)
3924 struct CadetTConnection *iter;
3930 for (count = 0, iter = t->connection_head; NULL != iter; iter = iter->next)
3938 * Count established (ready) connections of a tunnel.
3940 * @param t Tunnel on which to count.
3942 * @return Number of connections.
3945 GCT_count_connections (struct CadetTunnel *t)
3947 struct CadetTConnection *iter;
3953 for (count = 0, iter = t->connection_head; NULL != iter; iter = iter->next)
3954 if (CADET_CONNECTION_READY == GCC_get_state (iter->c))
3962 * Count channels of a tunnel.
3964 * @param t Tunnel on which to count.
3966 * @return Number of channels.
3969 GCT_count_channels (struct CadetTunnel *t)
3971 struct CadetTChannel *iter;
3974 for (count = 0, iter = t->channel_head;
3976 iter = iter->next, count++) /* skip */;
3983 * Get the connectivity state of a tunnel.
3987 * @return Tunnel's connectivity state.
3989 enum CadetTunnelCState
3990 GCT_get_cstate (struct CadetTunnel *t)
3995 return (enum CadetTunnelCState) -1;
4002 * Get the encryption state of a tunnel.
4006 * @return Tunnel's encryption state.
4008 enum CadetTunnelEState
4009 GCT_get_estate (struct CadetTunnel *t)
4014 return (enum CadetTunnelEState) -1;
4020 * Get the maximum buffer space for a tunnel towards a local client.
4024 * @return Biggest buffer space offered by any channel in the tunnel.
4027 GCT_get_channels_buffer (struct CadetTunnel *t)
4029 struct CadetTChannel *iter;
4030 unsigned int buffer;
4031 unsigned int ch_buf;
4033 if (NULL == t->channel_head)
4035 /* Probably getting buffer for a channel create/handshake. */
4036 LOG (GNUNET_ERROR_TYPE_DEBUG, " no channels, allow max\n");
4037 return MIN_TUNNEL_BUFFER;
4041 for (iter = t->channel_head; NULL != iter; iter = iter->next)
4043 ch_buf = get_channel_buffer (iter);
4044 if (ch_buf > buffer)
4047 if (MIN_TUNNEL_BUFFER > buffer)
4048 return MIN_TUNNEL_BUFFER;
4050 if (MAX_TUNNEL_BUFFER < buffer)
4053 return MAX_TUNNEL_BUFFER;
4060 * Get the total buffer space for a tunnel for P2P traffic.
4064 * @return Buffer space offered by all connections in the tunnel.
4067 GCT_get_connections_buffer (struct CadetTunnel *t)
4069 struct CadetTConnection *iter;
4070 unsigned int buffer;
4072 if (GNUNET_NO == is_ready (t))
4074 if (count_queued_data (t) >= 3)
4081 for (iter = t->connection_head; NULL != iter; iter = iter->next)
4083 if (GCC_get_state (iter->c) != CADET_CONNECTION_READY)
4087 buffer += get_connection_buffer (iter);
4095 * Get the tunnel's destination.
4099 * @return ID of the destination peer.
4101 const struct GNUNET_PeerIdentity *
4102 GCT_get_destination (struct CadetTunnel *t)
4104 return GCP_get_id (t->peer);
4109 * Get the tunnel's next free global channel ID.
4113 * @return GID of a channel free to use.
4116 GCT_get_next_chid (struct CadetTunnel *t)
4118 CADET_ChannelNumber chid;
4119 CADET_ChannelNumber mask;
4122 /* Set bit 30 depending on the ID relationship. Bit 31 is always 0 for GID.
4123 * If our ID is bigger or loopback tunnel, start at 0, bit 30 = 0
4124 * If peer's ID is bigger, start at 0x4... bit 30 = 1
4126 result = GNUNET_CRYPTO_cmp_peer_identity (&my_full_id, GCP_get_id (t->peer));
4131 t->next_chid |= mask;
4133 while (NULL != GCT_get_channel (t, t->next_chid))
4135 LOG (GNUNET_ERROR_TYPE_DEBUG, "Channel %u exists...\n", t->next_chid);
4136 t->next_chid = (t->next_chid + 1) & ~GNUNET_CADET_LOCAL_CHANNEL_ID_CLI;
4137 t->next_chid |= mask;
4139 chid = t->next_chid;
4140 t->next_chid = (t->next_chid + 1) & ~GNUNET_CADET_LOCAL_CHANNEL_ID_CLI;
4141 t->next_chid |= mask;
4148 * Send ACK on one or more channels due to buffer in connections.
4150 * @param t Channel which has some free buffer space.
4153 GCT_unchoke_channels (struct CadetTunnel *t)
4155 struct CadetTChannel *iter;
4156 unsigned int buffer;
4157 unsigned int channels = GCT_count_channels (t);
4158 unsigned int choked_n;
4159 struct CadetChannel *choked[channels];
4161 LOG (GNUNET_ERROR_TYPE_DEBUG, "GCT_unchoke_channels on %s\n", GCT_2s (t));
4162 LOG (GNUNET_ERROR_TYPE_DEBUG, " head: %p\n", t->channel_head);
4163 if (NULL != t->channel_head)
4164 LOG (GNUNET_ERROR_TYPE_DEBUG, " head ch: %p\n", t->channel_head->ch);
4166 if (NULL != t->tq_head)
4167 send_queued_data (t);
4169 /* Get buffer space */
4170 buffer = GCT_get_connections_buffer (t);
4176 /* Count and remember choked channels */
4178 for (iter = t->channel_head; NULL != iter; iter = iter->next)
4180 if (GNUNET_NO == get_channel_allowed (iter))
4182 choked[choked_n++] = iter->ch;
4186 /* Unchoke random channels */
4187 while (0 < buffer && 0 < choked_n)
4189 unsigned int r = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK,
4191 GCCH_allow_client (choked[r], GCCH_is_origin (choked[r], GNUNET_YES));
4194 choked[r] = choked[choked_n];
4200 * Send ACK on one or more connections due to buffer space to the client.
4202 * Iterates all connections of the tunnel and sends ACKs appropriately.
4207 GCT_send_connection_acks (struct CadetTunnel *t)
4209 struct CadetTConnection *iter;
4212 uint32_t allow_per_connection;
4214 unsigned int buffer;
4216 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel send connection ACKs on %s\n",
4225 if (CADET_TUNNEL_READY != t->cstate)
4228 buffer = GCT_get_channels_buffer (t);
4229 LOG (GNUNET_ERROR_TYPE_DEBUG, " buffer %u\n", buffer);
4231 /* Count connections, how many messages are already allowed */
4232 cs = GCT_count_connections (t);
4233 for (allowed = 0, iter = t->connection_head; NULL != iter; iter = iter->next)
4235 allowed += get_connection_allowed (iter);
4237 LOG (GNUNET_ERROR_TYPE_DEBUG, " allowed %u\n", allowed);
4239 /* Make sure there is no overflow */
4240 if (allowed > buffer)
4243 /* Authorize connections to send more data */
4244 to_allow = buffer - allowed;
4246 for (iter = t->connection_head;
4247 NULL != iter && to_allow > 0;
4250 if (CADET_CONNECTION_READY != GCC_get_state (iter->c)
4251 || get_connection_allowed (iter) > 64 / 3)
4255 allow_per_connection = to_allow/cs;
4256 to_allow -= allow_per_connection;
4258 GCC_allow (iter->c, allow_per_connection,
4259 GCC_is_origin (iter->c, GNUNET_NO));
4264 /* Since we don't allow if it's allowed to send 64/3, this can happen. */
4265 LOG (GNUNET_ERROR_TYPE_DEBUG, " reminding to_allow: %u\n", to_allow);
4271 * Cancel a previously sent message while it's in the queue.
4273 * ONLY can be called before the continuation given to the send function
4274 * is called. Once the continuation is called, the message is no longer in the
4277 * @param q Handle to the queue.
4280 GCT_cancel (struct CadetTunnelQueue *q)
4284 GNUNET_assert (NULL == q->tqd);
4286 /* tun_message_sent() will be called and free q */
4288 else if (NULL != q->tqd)
4290 unqueue_data (q->tqd);
4292 if (NULL != q->cont)
4293 q->cont (q->cont_cls, NULL, q, 0, 0);
4304 * Check if the tunnel has queued traffic.
4306 * @param t Tunnel to check.
4308 * @return #GNUNET_YES if there is queued traffic
4309 * #GNUNET_NO otherwise
4312 GCT_has_queued_traffic (struct CadetTunnel *t)
4314 return (NULL != t->tq_head) ? GNUNET_YES : GNUNET_NO;
4319 * Sends an already built message on a tunnel, encrypting it and
4320 * choosing the best connection if not provided.
4322 * @param message Message to send. Function modifies it.
4323 * @param t Tunnel on which this message is transmitted.
4324 * @param c Connection to use (autoselect if NULL).
4325 * @param force Force the tunnel to take the message (buffer overfill).
4326 * @param cont Continuation to call once message is really sent.
4327 * @param cont_cls Closure for @c cont.
4329 * @return Handle to cancel message. NULL if @c cont is NULL.
4331 struct CadetTunnelQueue *
4332 GCT_send_prebuilt_message (const struct GNUNET_MessageHeader *message,
4333 struct CadetTunnel *t, struct CadetConnection *c,
4334 int force, GCT_sent cont, void *cont_cls)
4336 return send_prebuilt_message (message, t, c, force, cont, cont_cls, NULL);
4341 * Send an Axolotl KX message.
4343 * @param t Tunnel on which to send it.
4344 * @param force_reply Force the other peer to reply with a KX message.
4347 GCT_send_ax_kx (struct CadetTunnel *t, int force_reply)
4349 struct GNUNET_CADET_AX_KX msg;
4350 enum GNUNET_CADET_AX_KX_Flags flags;
4352 LOG (GNUNET_ERROR_TYPE_INFO, "==> { AX_KX} on %s\n", GCT_2s (t));
4353 if (NULL != t->ephm_h)
4355 LOG (GNUNET_ERROR_TYPE_INFO, " already queued\n");
4359 msg.header.size = htons (sizeof (msg));
4360 msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_AX_KX);
4361 flags = GNUNET_CADET_AX_KX_FLAG_NONE;
4363 flags |= GNUNET_CADET_AX_KX_FLAG_FORCE_REPLY;
4364 msg.flags = htonl (flags);
4365 GNUNET_CRYPTO_ecdhe_key_get_public (t->ax->kx_0, &msg.ephemeral_key);
4366 GNUNET_CRYPTO_ecdhe_key_get_public (t->ax->DHRs, &msg.ratchet_key);
4368 t->ephm_h = send_kx (t, &msg.header);
4369 if (CADET_TUNNEL_KEY_UNINITIALIZED == t->estate)
4370 GCT_change_estate (t, CADET_TUNNEL_KEY_SENT);
4375 * Sends an already built and encrypted message on a tunnel, choosing the best
4376 * connection. Useful for re-queueing messages queued on a destroyed connection.
4378 * @param message Message to send. Function modifies it.
4379 * @param t Tunnel on which this message is transmitted.
4382 GCT_resend_message (const struct GNUNET_MessageHeader *message,
4383 struct CadetTunnel *t)
4385 struct CadetConnection *c;
4388 c = tunnel_get_connection (t);
4391 /* TODO queue in tunnel, marked as encrypted */
4392 LOG (GNUNET_ERROR_TYPE_DEBUG, "No connection available, dropping.\n");
4395 fwd = GCC_is_origin (c, GNUNET_YES);
4396 GNUNET_break (NULL == GCC_send_prebuilt_message (message, UINT16_MAX, 0,
4398 GNUNET_YES, NULL, NULL));
4403 * Is the tunnel directed towards the local peer?
4407 * @return #GNUNET_YES if it is loopback.
4410 GCT_is_loopback (const struct CadetTunnel *t)
4412 return (myid == GCP_get_short_id (t->peer));
4417 * Is the tunnel this path already?
4422 * @return #GNUNET_YES a connection uses this path.
4425 GCT_is_path_used (const struct CadetTunnel *t, const struct CadetPeerPath *p)
4427 struct CadetTConnection *iter;
4429 for (iter = t->connection_head; NULL != iter; iter = iter->next)
4430 if (path_equivalent (GCC_get_path (iter->c), p))
4438 * Get a cost of a path for a tunnel considering existing connections.
4441 * @param path Candidate path.
4443 * @return Cost of the path (path length + number of overlapping nodes)
4446 GCT_get_path_cost (const struct CadetTunnel *t,
4447 const struct CadetPeerPath *path)
4449 struct CadetTConnection *iter;
4450 const struct CadetPeerPath *aux;
4451 unsigned int overlap;
4459 GNUNET_assert (NULL != t);
4461 for (i = 0; i < path->length; i++)
4463 for (iter = t->connection_head; NULL != iter; iter = iter->next)
4465 aux = GCC_get_path (iter->c);
4469 for (j = 0; j < aux->length; j++)
4471 if (path->peers[i] == aux->peers[j])
4479 return path->length + overlap;
4484 * Get the static string for the peer this tunnel is directed.
4488 * @return Static string the destination peer's ID.
4491 GCT_2s (const struct CadetTunnel *t)
4496 return GCP_2s (t->peer);
4500 /******************************************************************************/
4501 /***************************** INFO/DEBUG *******************************/
4502 /******************************************************************************/
4505 ax_debug (const struct CadetTunnelAxolotl *ax, enum GNUNET_ErrorType level)
4507 struct GNUNET_CRYPTO_EcdhePublicKey pub;
4508 struct CadetTunnelSkippedKey *iter;
4510 LOG2 (level, "TTT RK \t %s\n",
4511 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &ax->RK));
4513 LOG2 (level, "TTT HKs \t %s\n",
4514 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &ax->HKs));
4515 LOG2 (level, "TTT HKr \t %s\n",
4516 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &ax->HKr));
4517 LOG2 (level, "TTT NHKs\t %s\n",
4518 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &ax->NHKs));
4519 LOG2 (level, "TTT NHKr\t %s\n",
4520 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &ax->NHKr));
4522 LOG2 (level, "TTT CKs \t %s\n",
4523 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &ax->CKs));
4524 LOG2 (level, "TTT CKr \t %s\n",
4525 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &ax->CKr));
4527 GNUNET_CRYPTO_ecdhe_key_get_public (ax->DHRs, &pub);
4528 LOG2 (level, "TTT DHRs\t %s\n",
4529 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &pub));
4530 LOG2 (level, "TTT DHRr\t %s\n",
4531 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &ax->DHRr));
4533 LOG2 (level, "TTT Nr\t %u\tNs\t%u\n", ax->Nr, ax->Ns);
4534 LOG2 (level, "TTT PNs\t %u\tSkipped\t%u\n", ax->PNs, ax->skipped);
4535 LOG2 (level, "TTT Ratchet\t%u\n", ax->ratchet_flag);
4537 for (iter = ax->skipped_head; NULL != iter; iter = iter->next)
4539 LOG2 (level, "TTT HK\t %s\n",
4540 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &iter->HK));
4541 LOG2 (level, "TTT MK\t %s\n",
4542 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &iter->MK));
4547 * Log all possible info about the tunnel state.
4549 * @param t Tunnel to debug.
4550 * @param level Debug level to use.
4553 GCT_debug (const struct CadetTunnel *t, enum GNUNET_ErrorType level)
4555 struct CadetTChannel *iterch;
4556 struct CadetTConnection *iterc;
4559 do_log = GNUNET_get_log_call_status (level & (~GNUNET_ERROR_TYPE_BULK),
4561 __FILE__, __FUNCTION__, __LINE__);
4565 LOG2 (level, "TTT DEBUG TUNNEL TOWARDS %s\n", GCT_2s (t));
4566 LOG2 (level, "TTT cstate %s, estate %s\n",
4567 cstate2s (t->cstate), estate2s (t->estate));
4568 LOG2 (level, "TTT kx_ctx %p, rekey_task %u, finish task %u\n",
4569 t->kx_ctx, t->rekey_task, t->kx_ctx ? t->kx_ctx->finish_task : 0);
4570 #if DUMP_KEYS_TO_STDERR
4571 if (CADET_Axolotl == t->enc_type)
4573 ax_debug (t->ax, level);
4577 LOG2 (level, "TTT my EPHM\t %s\n",
4578 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &otr_kx_msg.ephemeral_key));
4579 LOG2 (level, "TTT peers EPHM:\t %s\n",
4580 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &t->peers_ephemeral_key));
4581 LOG2 (level, "TTT ENC key:\t %s\n",
4582 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &t->e_key));
4583 LOG2 (level, "TTT DEC key:\t %s\n",
4584 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &t->d_key));
4587 LOG2 (level, "TTT OLD ENC key:\t %s\n",
4588 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &t->kx_ctx->e_key_old));
4589 LOG2 (level, "TTT OLD DEC key:\t %s\n",
4590 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &t->kx_ctx->d_key_old));
4594 LOG2 (level, "TTT tq_head %p, tq_tail %p\n", t->tq_head, t->tq_tail);
4595 LOG2 (level, "TTT destroy %p\n", t->destroy_task);
4597 LOG2 (level, "TTT channels:\n");
4598 for (iterch = t->channel_head; NULL != iterch; iterch = iterch->next)
4600 GCCH_debug (iterch->ch, level);
4603 LOG2 (level, "TTT connections:\n");
4604 for (iterc = t->connection_head; NULL != iterc; iterc = iterc->next)
4606 GCC_debug (iterc->c, level);
4609 LOG2 (level, "TTT DEBUG TUNNEL END\n");
4614 * Iterate all tunnels.
4616 * @param iter Iterator.
4617 * @param cls Closure for @c iter.
4620 GCT_iterate_all (GNUNET_CONTAINER_PeerMapIterator iter, void *cls)
4622 GNUNET_CONTAINER_multipeermap_iterate (tunnels, iter, cls);
4627 * Count all tunnels.
4629 * @return Number of tunnels to remote peers kept by this peer.
4632 GCT_count_all (void)
4634 return GNUNET_CONTAINER_multipeermap_size (tunnels);
4639 * Iterate all connections of a tunnel.
4641 * @param t Tunnel whose connections to iterate.
4642 * @param iter Iterator.
4643 * @param cls Closure for @c iter.
4646 GCT_iterate_connections (struct CadetTunnel *t, GCT_conn_iter iter, void *cls)
4648 struct CadetTConnection *ct;
4650 for (ct = t->connection_head; NULL != ct; ct = ct->next)
4656 * Iterate all channels of a tunnel.
4658 * @param t Tunnel whose channels to iterate.
4659 * @param iter Iterator.
4660 * @param cls Closure for @c iter.
4663 GCT_iterate_channels (struct CadetTunnel *t, GCT_chan_iter iter, void *cls)
4665 struct CadetTChannel *cht;
4667 for (cht = t->channel_head; NULL != cht; cht = cht->next)
4668 iter (cls, cht->ch);