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))
53 /******************************************************************************/
54 /******************************** STRUCTS **********************************/
55 /******************************************************************************/
59 struct CadetTChannel *next;
60 struct CadetTChannel *prev;
61 struct CadetChannel *ch;
66 * Connection list and metadata.
68 struct CadetTConnection
73 struct CadetTConnection *next;
78 struct CadetTConnection *prev;
83 struct CadetConnection *c;
86 * Creation time, to keep oldest connection alive.
88 struct GNUNET_TIME_Absolute created;
91 * Connection throughput, to keep fastest connection alive.
98 * Struct to old keys for skipped messages while advancing the Axolotl ratchet.
100 struct CadetTunnelSkippedKey
105 struct CadetTunnelSkippedKey *next;
110 struct CadetTunnelSkippedKey *prev;
113 * When was this key stored (for timeout).
115 struct GNUNET_TIME_Absolute timestamp;
120 struct GNUNET_CRYPTO_SymmetricSessionKey HK;
125 struct GNUNET_CRYPTO_SymmetricSessionKey MK;
128 * Key number for a given HK.
135 * Axolotl data, according to https://github.com/trevp/axolotl/wiki .
137 struct CadetTunnelAxolotl
140 * A (double linked) list of stored message keys and associated header keys
141 * for "skipped" messages, i.e. messages that have not been
142 * received despite the reception of more recent messages, (head).
144 struct CadetTunnelSkippedKey *skipped_head;
147 * Skipped messages' keys DLL, tail.
149 struct CadetTunnelSkippedKey *skipped_tail;
152 * Elements in @a skipped_head <-> @a skipped_tail.
154 unsigned int skipped;
157 * 32-byte root key which gets updated by DH ratchet.
159 struct GNUNET_CRYPTO_SymmetricSessionKey RK;
162 * 32-byte header key (send).
164 struct GNUNET_CRYPTO_SymmetricSessionKey HKs;
167 * 32-byte header key (recv)
169 struct GNUNET_CRYPTO_SymmetricSessionKey HKr;
172 * 32-byte next header key (send).
174 struct GNUNET_CRYPTO_SymmetricSessionKey NHKs;
177 * 32-byte next header key (recv).
179 struct GNUNET_CRYPTO_SymmetricSessionKey NHKr;
182 * 32-byte chain keys (used for forward-secrecy updating, send).
184 struct GNUNET_CRYPTO_SymmetricSessionKey CKs;
187 * 32-byte chain keys (used for forward-secrecy updating, recv).
189 struct GNUNET_CRYPTO_SymmetricSessionKey CKr;
192 * ECDH for key exchange (A0 / B0).
194 struct GNUNET_CRYPTO_EcdhePrivateKey *kx_0;
197 * ECDH Ratchet key (send).
199 struct GNUNET_CRYPTO_EcdhePrivateKey *DHRs;
202 * ECDH Ratchet key (recv).
204 struct GNUNET_CRYPTO_EcdhePublicKey DHRr;
207 * Message number (reset to 0 with each new ratchet, next message to send).
212 * Message number (reset to 0 with each new ratchet, next message to recv).
217 * Previous message numbers (# of msgs sent under prev ratchet)
222 * True (#GNUNET_YES) if we have to send a new ratchet key in next msg.
227 * Number of messages recieved since our last ratchet advance.
228 * - If this counter = 0, we cannot send a new ratchet key in next msg.
229 * - If this counter > 0, we can (but don't yet have to) send a new key.
231 unsigned int ratchet_allowed;
234 * Number of messages recieved since our last ratchet advance.
235 * - If this counter = 0, we cannot send a new ratchet key in next msg.
236 * - If this counter > 0, we can (but don't yet have to) send a new key.
238 unsigned int ratchet_counter;
241 * When does this ratchet expire and a new one is triggered.
243 struct GNUNET_TIME_Absolute ratchet_expiration;
247 * Struct containing all information regarding a tunnel to a peer.
252 * Endpoint of the tunnel.
254 struct CadetPeer *peer;
259 struct CadetTunnelAxolotl *ax;
262 * State of the tunnel connectivity.
264 enum CadetTunnelCState cstate;
267 * State of the tunnel encryption.
269 enum CadetTunnelEState estate;
272 * Peer's ephemeral key, to recreate @c e_key and @c d_key when own ephemeral
275 struct GNUNET_CRYPTO_EcdhePublicKey peers_ephemeral_key;
278 * Encryption ("our") key. It is only "confirmed" if kx_ctx is NULL.
280 struct GNUNET_CRYPTO_SymmetricSessionKey e_key;
283 * Decryption ("their") key. It is only "confirmed" if kx_ctx is NULL.
285 struct GNUNET_CRYPTO_SymmetricSessionKey d_key;
288 * Task to start the rekey process.
290 struct GNUNET_SCHEDULER_Task *rekey_task;
293 * Paths that are actively used to reach the destination peer.
295 struct CadetTConnection *connection_head;
296 struct CadetTConnection *connection_tail;
299 * Next connection number.
304 * Channels inside this tunnel.
306 struct CadetTChannel *channel_head;
307 struct CadetTChannel *channel_tail;
310 * Channel ID for the next created channel.
312 CADET_ChannelNumber next_chid;
315 * Destroy flag: if true, destroy on last message.
317 struct GNUNET_SCHEDULER_Task * destroy_task;
320 * Queued messages, to transmit once tunnel gets connected.
322 struct CadetTunnelDelayed *tq_head;
323 struct CadetTunnelDelayed *tq_tail;
326 * Task to trim connections if too many are present.
328 struct GNUNET_SCHEDULER_Task * trim_connections_task;
331 * Ephemeral message in the queue (to avoid queueing more than one).
333 struct CadetConnectionQueue *ephm_h;
336 * Pong message in the queue.
338 struct CadetConnectionQueue *pong_h;
343 * Struct used to save messages in a non-ready tunnel to send once connected.
345 struct CadetTunnelDelayed
350 struct CadetTunnelDelayed *next;
351 struct CadetTunnelDelayed *prev;
356 struct CadetTunnel *t;
359 * Tunnel queue given to the channel to cancel request. Update on send_queued.
361 struct CadetTunnelQueue *tq;
366 /* struct GNUNET_MessageHeader *msg; */
371 * Handle for messages queued but not yet sent.
373 struct CadetTunnelQueue
376 * Connection queue handle, to cancel if necessary.
378 struct CadetConnectionQueue *cq;
381 * Handle in case message hasn't been given to a connection yet.
383 struct CadetTunnelDelayed *tqd;
386 * Continuation to call once sent.
391 * Closure for @c cont.
397 /******************************************************************************/
398 /******************************* GLOBALS ***********************************/
399 /******************************************************************************/
402 * Global handle to the statistics service.
404 extern struct GNUNET_STATISTICS_Handle *stats;
407 * Local peer own ID (memory efficient handle).
409 extern GNUNET_PEER_Id myid;
412 * Local peer own ID (full value).
414 extern struct GNUNET_PeerIdentity my_full_id;
418 * Don't try to recover tunnels if shutting down.
420 extern int shutting_down;
424 * Set of all tunnels, in order to trigger a new exchange on rekey.
425 * Indexed by peer's ID.
427 static struct GNUNET_CONTAINER_MultiPeerMap *tunnels;
430 * Own Peer ID private key.
432 const static struct GNUNET_CRYPTO_EddsaPrivateKey *id_key;
435 /******************************** AXOLOTL ************************************/
438 * How many messages are needed to trigger a ratchet advance.
440 static unsigned long long ratchet_messages;
443 * How long until we trigger a ratched advance.
445 static struct GNUNET_TIME_Relative ratchet_time;
448 /******************************************************************************/
449 /******************************** STATIC ***********************************/
450 /******************************************************************************/
453 * Get string description for tunnel connectivity state.
455 * @param cs Tunnel state.
457 * @return String representation.
460 cstate2s (enum CadetTunnelCState cs)
466 case CADET_TUNNEL_NEW:
467 return "CADET_TUNNEL_NEW";
468 case CADET_TUNNEL_SEARCHING:
469 return "CADET_TUNNEL_SEARCHING";
470 case CADET_TUNNEL_WAITING:
471 return "CADET_TUNNEL_WAITING";
472 case CADET_TUNNEL_READY:
473 return "CADET_TUNNEL_READY";
474 case CADET_TUNNEL_SHUTDOWN:
475 return "CADET_TUNNEL_SHUTDOWN";
477 SPRINTF (buf, "%u (UNKNOWN STATE)", cs);
485 * Get string description for tunnel encryption state.
487 * @param es Tunnel state.
489 * @return String representation.
492 estate2s (enum CadetTunnelEState es)
498 case CADET_TUNNEL_KEY_UNINITIALIZED:
499 return "CADET_TUNNEL_KEY_UNINITIALIZED";
500 case CADET_TUNNEL_KEY_SENT:
501 return "CADET_TUNNEL_KEY_SENT";
502 case CADET_TUNNEL_KEY_PING:
503 return "CADET_TUNNEL_KEY_PING";
504 case CADET_TUNNEL_KEY_OK:
505 return "CADET_TUNNEL_KEY_OK";
506 case CADET_TUNNEL_KEY_REKEY:
507 return "CADET_TUNNEL_KEY_REKEY";
509 SPRINTF (buf, "%u (UNKNOWN STATE)", es);
517 * @brief Check if tunnel is ready to send traffic.
519 * Tunnel must be connected and with encryption correctly set up.
521 * @param t Tunnel to check.
523 * @return #GNUNET_YES if ready, #GNUNET_NO otherwise
526 is_ready (struct CadetTunnel *t)
532 conn_ok = CADET_TUNNEL_READY == t->cstate;
533 enc_ok = CADET_TUNNEL_KEY_OK == t->estate
534 || CADET_TUNNEL_KEY_REKEY == t->estate
535 || CADET_TUNNEL_KEY_PING == t->estate;
536 ready = conn_ok && enc_ok;
537 ready = ready || GCT_is_loopback (t);
543 * Get the channel's buffer. ONLY FOR NON-LOOPBACK CHANNELS!!
545 * @param tch Tunnel's channel handle.
547 * @return Amount of messages the channel can still buffer towards the client.
550 get_channel_buffer (const struct CadetTChannel *tch)
554 /* If channel is incoming, is terminal in the FWD direction and fwd is YES */
555 fwd = GCCH_is_terminal (tch->ch, GNUNET_YES);
557 return GCCH_get_buffer (tch->ch, fwd);
562 * Get the channel's allowance status.
564 * @param tch Tunnel's channel handle.
566 * @return #GNUNET_YES if we allowed the client to send data to us.
569 get_channel_allowed (const struct CadetTChannel *tch)
573 /* If channel is outgoing, is origin in the FWD direction and fwd is YES */
574 fwd = GCCH_is_origin (tch->ch, GNUNET_YES);
576 return GCCH_get_allowed (tch->ch, fwd);
581 * Get the connection's buffer.
583 * @param tc Tunnel's connection handle.
585 * @return Amount of messages the connection can still buffer.
588 get_connection_buffer (const struct CadetTConnection *tc)
592 /* If connection is outgoing, is origin in the FWD direction and fwd is YES */
593 fwd = GCC_is_origin (tc->c, GNUNET_YES);
595 return GCC_get_buffer (tc->c, fwd);
600 * Get the connection's allowance.
602 * @param tc Tunnel's connection handle.
604 * @return Amount of messages we have allowed the next peer to send us.
607 get_connection_allowed (const struct CadetTConnection *tc)
611 /* If connection is outgoing, is origin in the FWD direction and fwd is YES */
612 fwd = GCC_is_origin (tc->c, GNUNET_YES);
614 return GCC_get_allowed (tc->c, fwd);
619 * Create a new Axolotl ephemeral (ratchet) key.
624 new_ephemeral (struct CadetTunnel *t)
626 GNUNET_free_non_null (t->ax->DHRs);
627 t->ax->DHRs = GNUNET_CRYPTO_ecdhe_key_create();
628 #if DUMP_KEYS_TO_STDERR
630 struct GNUNET_CRYPTO_EcdhePublicKey pub;
631 GNUNET_CRYPTO_ecdhe_key_get_public (t->ax->DHRs, &pub);
632 LOG (GNUNET_ERROR_TYPE_DEBUG, " new DHRs generated: pub %s\n",
633 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &pub));
642 * @param plaintext Content to HMAC.
643 * @param size Size of @c plaintext.
644 * @param iv Initialization vector for the message.
645 * @param key Key to use.
646 * @param hmac[out] Destination to store the HMAC.
649 t_hmac (const void *plaintext, size_t size,
650 uint32_t iv, const struct GNUNET_CRYPTO_SymmetricSessionKey *key,
651 struct GNUNET_CADET_Hash *hmac)
653 static const char ctx[] = "cadet authentication key";
654 struct GNUNET_CRYPTO_AuthKey auth_key;
655 struct GNUNET_HashCode hash;
657 #if DUMP_KEYS_TO_STDERR
658 LOG (GNUNET_ERROR_TYPE_INFO, " HMAC %u bytes with key %s\n", size,
659 GNUNET_i2s ((struct GNUNET_PeerIdentity *) key));
661 GNUNET_CRYPTO_hmac_derive_key (&auth_key, key,
666 /* Two step: CADET_Hash is only 256 bits, HashCode is 512. */
667 GNUNET_CRYPTO_hmac (&auth_key, plaintext, size, &hash);
668 GNUNET_memcpy (hmac, &hash, sizeof (*hmac));
675 * @param key Key to use.
676 * @param hash[out] Resulting HMAC.
677 * @param source Source key material (data to HMAC).
678 * @param len Length of @a source.
681 t_ax_hmac_hash (struct GNUNET_CRYPTO_SymmetricSessionKey *key,
682 struct GNUNET_HashCode *hash,
683 void *source, unsigned int len)
685 static const char ctx[] = "axolotl HMAC-HASH";
686 struct GNUNET_CRYPTO_AuthKey auth_key;
688 GNUNET_CRYPTO_hmac_derive_key (&auth_key, key,
691 GNUNET_CRYPTO_hmac (&auth_key, source, len, hash);
696 * Derive a key from a HMAC-HASH.
698 * @param key Key to use for the HMAC.
699 * @param out Key to generate.
700 * @param source Source key material (data to HMAC).
701 * @param len Length of @a source.
704 t_hmac_derive_key (struct GNUNET_CRYPTO_SymmetricSessionKey *key,
705 struct GNUNET_CRYPTO_SymmetricSessionKey *out,
706 void *source, unsigned int len)
708 static const char ctx[] = "axolotl derive key";
709 struct GNUNET_HashCode h;
711 t_ax_hmac_hash (key, &h, source, len);
712 GNUNET_CRYPTO_kdf (out, sizeof (*out), ctx, sizeof (ctx),
713 &h, sizeof (h), NULL);
718 * Encrypt data with the axolotl tunnel key.
720 * @param t Tunnel whose key to use.
721 * @param dst Destination for the encrypted data.
722 * @param src Source of the plaintext. Can overlap with @c dst.
723 * @param size Size of the plaintext.
725 * @return Size of the encrypted data.
728 t_ax_encrypt (struct CadetTunnel *t, void *dst, const void *src, size_t size)
730 struct GNUNET_CRYPTO_SymmetricSessionKey MK;
731 struct GNUNET_CRYPTO_SymmetricInitializationVector iv;
732 struct CadetTunnelAxolotl *ax;
738 ax->ratchet_counter++;
739 if (GNUNET_YES == ax->ratchet_allowed
740 && (ratchet_messages <= ax->ratchet_counter
741 || 0 == GNUNET_TIME_absolute_get_remaining (ax->ratchet_expiration).rel_value_us))
743 ax->ratchet_flag = GNUNET_YES;
746 if (GNUNET_YES == ax->ratchet_flag)
748 /* Advance ratchet */
749 struct GNUNET_CRYPTO_SymmetricSessionKey keys[3];
750 struct GNUNET_HashCode dh;
751 struct GNUNET_HashCode hmac;
752 static const char ctx[] = "axolotl ratchet";
757 /* RK, NHKs, CKs = KDF( HMAC-HASH(RK, DH(DHRs, DHRr)) ) */
758 GNUNET_CRYPTO_ecc_ecdh (ax->DHRs, &ax->DHRr, &dh);
759 t_ax_hmac_hash (&ax->RK, &hmac, &dh, sizeof (dh));
760 GNUNET_CRYPTO_kdf (keys, sizeof (keys), ctx, sizeof (ctx),
761 &hmac, sizeof (hmac), NULL);
768 ax->ratchet_flag = GNUNET_NO;
769 ax->ratchet_allowed = GNUNET_NO;
770 ax->ratchet_counter = 0;
771 ax->ratchet_expiration =
772 GNUNET_TIME_absolute_add (GNUNET_TIME_absolute_get(), ratchet_time);
775 t_hmac_derive_key (&ax->CKs, &MK, "0", 1);
776 GNUNET_CRYPTO_symmetric_derive_iv (&iv, &MK, NULL, 0, NULL);
778 #if DUMP_KEYS_TO_STDERR
779 LOG (GNUNET_ERROR_TYPE_DEBUG, " CKs: %s\n",
780 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &ax->CKs));
781 LOG (GNUNET_ERROR_TYPE_INFO, " AX_ENC with key %u: %s\n", ax->Ns,
782 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &MK));
785 out_size = GNUNET_CRYPTO_symmetric_encrypt (src, size, &MK, &iv, dst);
786 t_hmac_derive_key (&ax->CKs, &ax->CKs, "1", 1);
795 * Decrypt data with the axolotl tunnel key.
797 * @param t Tunnel whose key to use.
798 * @param dst Destination for the decrypted data.
799 * @param src Source of the ciphertext. Can overlap with @c dst.
800 * @param size Size of the ciphertext.
802 * @return Size of the decrypted data.
805 t_ax_decrypt (struct CadetTunnel *t, void *dst, const void *src, size_t size)
807 struct GNUNET_CRYPTO_SymmetricSessionKey MK;
808 struct GNUNET_CRYPTO_SymmetricInitializationVector iv;
809 struct CadetTunnelAxolotl *ax;
816 t_hmac_derive_key (&ax->CKr, &MK, "0", 1);
817 GNUNET_CRYPTO_symmetric_derive_iv (&iv, &MK, NULL, 0, NULL);
819 #if DUMP_KEYS_TO_STDERR
820 LOG (GNUNET_ERROR_TYPE_DEBUG, " CKr: %s\n",
821 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &ax->CKr));
822 LOG (GNUNET_ERROR_TYPE_INFO, " AX_DEC with key %u: %s\n", ax->Nr,
823 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &MK));
826 GNUNET_assert (size >= sizeof (struct GNUNET_MessageHeader));
827 out_size = GNUNET_CRYPTO_symmetric_decrypt (src, size, &MK, &iv, dst);
828 GNUNET_assert (out_size == size);
830 t_hmac_derive_key (&ax->CKr, &ax->CKr, "1", 1);
839 * Encrypt header with the axolotl header key.
841 * @param t Tunnel whose key to use.
842 * @param msg Message whose header to encrypt.
845 t_h_encrypt (struct CadetTunnel *t, struct GNUNET_CADET_Encrypted *msg)
847 struct GNUNET_CRYPTO_SymmetricInitializationVector iv;
848 struct CadetTunnelAxolotl *ax;
853 GNUNET_CRYPTO_symmetric_derive_iv (&iv, &ax->HKs, NULL, 0, NULL);
855 #if DUMP_KEYS_TO_STDERR
856 LOG (GNUNET_ERROR_TYPE_INFO, " AX_ENC_H with key %s\n",
857 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &ax->HKs));
860 out_size = GNUNET_CRYPTO_symmetric_encrypt (&msg->Ns, AX_HEADER_SIZE,
861 &ax->HKs, &iv, &msg->Ns);
863 GNUNET_assert (AX_HEADER_SIZE == out_size);
869 * Decrypt header with the current axolotl header key.
871 * @param t Tunnel whose current ax HK to use.
872 * @param src Message whose header to decrypt.
873 * @param dst Where to decrypt header to.
876 t_h_decrypt (struct CadetTunnel *t, const struct GNUNET_CADET_Encrypted *src,
877 struct GNUNET_CADET_Encrypted *dst)
879 struct GNUNET_CRYPTO_SymmetricInitializationVector iv;
880 struct CadetTunnelAxolotl *ax;
886 GNUNET_CRYPTO_symmetric_derive_iv (&iv, &ax->HKr, NULL, 0, NULL);
888 #if DUMP_KEYS_TO_STDERR
889 LOG (GNUNET_ERROR_TYPE_INFO, " AX_DEC_H with key %s\n",
890 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &ax->HKr));
893 out_size = GNUNET_CRYPTO_symmetric_decrypt (&src->Ns, AX_HEADER_SIZE,
894 &ax->HKr, &iv, &dst->Ns);
896 GNUNET_assert (AX_HEADER_SIZE == out_size);
903 * Decrypt and verify data with the appropriate tunnel key and verify that the
904 * data has not been altered since it was sent by the remote peer.
906 * @param t Tunnel whose key to use.
907 * @param dst Destination for the plaintext.
908 * @param src Source of the message. Can overlap with @c dst.
909 * @param size Size of the message.
911 * @return Size of the decrypted data, -1 if an error was encountered.
914 try_old_ax_keys (struct CadetTunnel *t, void *dst,
915 const struct GNUNET_CADET_Encrypted *src, size_t size)
917 struct CadetTunnelSkippedKey *key;
918 struct GNUNET_CADET_Hash *hmac;
919 struct GNUNET_CRYPTO_SymmetricInitializationVector iv;
920 struct GNUNET_CADET_Encrypted plaintext_header;
921 struct GNUNET_CRYPTO_SymmetricSessionKey *valid_HK;
927 LOG (GNUNET_ERROR_TYPE_DEBUG, "Trying old keys\n");
928 hmac = &plaintext_header.hmac;
929 esize = size - sizeof (struct GNUNET_CADET_Encrypted);
931 /* Find a correct Header Key */
932 for (key = t->ax->skipped_head; NULL != key; key = key->next)
934 #if DUMP_KEYS_TO_STDERR
935 LOG (GNUNET_ERROR_TYPE_DEBUG, " Trying hmac with key %s\n",
936 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &key->HK));
938 t_hmac (&src->Ns, AX_HEADER_SIZE + esize, 0, &key->HK, hmac);
939 if (0 == memcmp (hmac, &src->hmac, sizeof (*hmac)))
941 LOG (GNUNET_ERROR_TYPE_DEBUG, " hmac correct\n");
949 /* Should've been checked in -cadet_connection.c handle_cadet_encrypted. */
950 GNUNET_assert (size > sizeof (struct GNUNET_CADET_Encrypted));
951 len = size - sizeof (struct GNUNET_CADET_Encrypted);
952 GNUNET_assert (len >= sizeof (struct GNUNET_MessageHeader));
955 GNUNET_CRYPTO_symmetric_derive_iv (&iv, &key->HK, NULL, 0, NULL);
956 res = GNUNET_CRYPTO_symmetric_decrypt (&src->Ns, AX_HEADER_SIZE,
957 &key->HK, &iv, &plaintext_header.Ns);
958 GNUNET_assert (AX_HEADER_SIZE == res);
959 LOG (GNUNET_ERROR_TYPE_DEBUG, " Message %u, previous: %u\n",
960 ntohl (plaintext_header.Ns), ntohl (plaintext_header.PNs));
962 /* Find the correct Message Key */
963 N = ntohl (plaintext_header.Ns);
964 while (NULL != key && N != key->Kn)
966 if (NULL == key || 0 != memcmp (&key->HK, valid_HK, sizeof (*valid_HK)))
969 #if DUMP_KEYS_TO_STDERR
970 LOG (GNUNET_ERROR_TYPE_INFO, " AX_DEC_H with skipped key %s\n",
971 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &key->HK));
972 LOG (GNUNET_ERROR_TYPE_INFO, " AX_DEC with skipped key %u: %s\n",
973 key->Kn, GNUNET_i2s ((struct GNUNET_PeerIdentity *) &key->MK));
976 /* Decrypt payload */
977 GNUNET_CRYPTO_symmetric_derive_iv (&iv, &key->MK, NULL, 0, NULL);
978 res = GNUNET_CRYPTO_symmetric_decrypt (&src[1], len, &key->MK, &iv, dst);
981 GNUNET_CONTAINER_DLL_remove (t->ax->skipped_head, t->ax->skipped_tail, key);
983 GNUNET_free (key); /* GNUNET_free overwrites memory with 0xbaadf00d */
990 * Delete a key from the list of skipped keys.
992 * @param t Tunnel to delete from.
993 * @param HKr Header Key to use.
996 store_skipped_key (struct CadetTunnel *t,
997 const struct GNUNET_CRYPTO_SymmetricSessionKey *HKr)
999 struct CadetTunnelSkippedKey *key;
1001 key = GNUNET_new (struct CadetTunnelSkippedKey);
1002 key->timestamp = GNUNET_TIME_absolute_get ();
1003 key->Kn = t->ax->Nr;
1004 key->HK = t->ax->HKr;
1005 t_hmac_derive_key (&t->ax->CKr, &key->MK, "0", 1);
1006 #if DUMP_KEYS_TO_STDERR
1007 LOG (GNUNET_ERROR_TYPE_DEBUG, " storing MK for Nr %u: %s\n",
1008 key->Kn, GNUNET_i2s ((struct GNUNET_PeerIdentity *) &key->MK));
1009 LOG (GNUNET_ERROR_TYPE_DEBUG, " for CKr: %s\n",
1010 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &t->ax->CKr));
1012 t_hmac_derive_key (&t->ax->CKr, &t->ax->CKr, "1", 1);
1013 GNUNET_CONTAINER_DLL_insert (t->ax->skipped_head, t->ax->skipped_tail, key);
1020 * Delete a key from the list of skipped keys.
1022 * @param t Tunnel to delete from.
1023 * @param key Key to delete.
1026 delete_skipped_key (struct CadetTunnel *t, struct CadetTunnelSkippedKey *key)
1028 GNUNET_CONTAINER_DLL_remove (t->ax->skipped_head, t->ax->skipped_tail, key);
1035 * Stage skipped AX keys and calculate the message key.
1037 * Stores each HK and MK for skipped messages.
1039 * @param t Tunnel where to stage the keys.
1040 * @param HKr Header key.
1041 * @param Np Received meesage number.
1043 * @return GNUNET_OK if keys were stored.
1044 * GNUNET_SYSERR if an error ocurred (Np not expected).
1047 store_ax_keys (struct CadetTunnel *t,
1048 const struct GNUNET_CRYPTO_SymmetricSessionKey *HKr,
1054 gap = Np - t->ax->Nr;
1055 LOG (GNUNET_ERROR_TYPE_INFO, "Storing keys [%u, %u)\n", t->ax->Nr, Np);
1056 if (MAX_KEY_GAP < gap)
1058 /* Avoid DoS (forcing peer to do 2*33 chain HMAC operations) */
1059 /* TODO: start new key exchange on return */
1060 GNUNET_break_op (0);
1061 LOG (GNUNET_ERROR_TYPE_WARNING, "Got message %u, expected %u+\n",
1063 return GNUNET_SYSERR;
1067 /* Delayed message: don't store keys, flag to try old keys. */
1068 return GNUNET_SYSERR;
1071 while (t->ax->Nr < Np)
1072 store_skipped_key (t, HKr);
1074 while (t->ax->skipped > MAX_SKIPPED_KEYS)
1075 delete_skipped_key (t, t->ax->skipped_tail);
1082 * Decrypt and verify data with the appropriate tunnel key and verify that the
1083 * data has not been altered since it was sent by the remote peer.
1085 * @param t Tunnel whose key to use.
1086 * @param dst Destination for the plaintext.
1087 * @param src Source of the message. Can overlap with @c dst.
1088 * @param size Size of the message.
1090 * @return Size of the decrypted data, -1 if an error was encountered.
1093 t_ax_decrypt_and_validate (struct CadetTunnel *t, void *dst,
1094 const struct GNUNET_CADET_Encrypted *src,
1097 struct CadetTunnelAxolotl *ax;
1098 struct GNUNET_CADET_Hash msg_hmac;
1099 struct GNUNET_HashCode hmac;
1100 struct GNUNET_CADET_Encrypted plaintext_header;
1103 size_t esize; /* Size of encryped payload */
1104 size_t osize; /* Size of output (decrypted payload) */
1106 esize = size - sizeof (struct GNUNET_CADET_Encrypted);
1111 /* Try current HK */
1112 t_hmac (&src->Ns, AX_HEADER_SIZE + esize, 0, &ax->HKr, &msg_hmac);
1113 if (0 != memcmp (&msg_hmac, &src->hmac, sizeof (msg_hmac)))
1115 static const char ctx[] = "axolotl ratchet";
1116 struct GNUNET_CRYPTO_SymmetricSessionKey keys[3]; /* RKp, NHKp, CKp */
1117 struct GNUNET_CRYPTO_SymmetricSessionKey HK;
1118 struct GNUNET_HashCode dh;
1119 struct GNUNET_CRYPTO_EcdhePublicKey *DHRp;
1122 LOG (GNUNET_ERROR_TYPE_DEBUG, " trying next HK\n");
1123 t_hmac (&src->Ns, AX_HEADER_SIZE + esize, 0, &ax->NHKr, &msg_hmac);
1124 if (0 != memcmp (&msg_hmac, &src->hmac, sizeof (msg_hmac)))
1126 /* Try the skipped keys, if that fails, we're out of luck. */
1127 return try_old_ax_keys (t, dst, src, size);
1129 LOG (GNUNET_ERROR_TYPE_INFO, "next HK worked\n");
1133 t_h_decrypt (t, src, &plaintext_header);
1134 Np = ntohl (plaintext_header.Ns);
1135 PNp = ntohl (plaintext_header.PNs);
1136 DHRp = &plaintext_header.DHRs;
1137 store_ax_keys (t, &HK, PNp);
1139 /* RKp, NHKp, CKp = KDF (HMAC-HASH (RK, DH (DHRp, DHRs))) */
1140 GNUNET_CRYPTO_ecc_ecdh (ax->DHRs, DHRp, &dh);
1141 t_ax_hmac_hash (&ax->RK, &hmac, &dh, sizeof (dh));
1142 GNUNET_CRYPTO_kdf (keys, sizeof (keys), ctx, sizeof (ctx),
1143 &hmac, sizeof (hmac), NULL);
1145 /* Commit "purported" keys */
1151 ax->ratchet_allowed = GNUNET_YES;
1155 LOG (GNUNET_ERROR_TYPE_DEBUG, "current HK\n");
1156 t_h_decrypt (t, src, &plaintext_header);
1157 Np = ntohl (plaintext_header.Ns);
1158 PNp = ntohl (plaintext_header.PNs);
1160 LOG (GNUNET_ERROR_TYPE_INFO, " got AX Nr %u\n", Np);
1162 if (GNUNET_OK != store_ax_keys (t, &ax->HKr, Np))
1163 /* Try the skipped keys, if that fails, we're out of luck. */
1164 return try_old_ax_keys (t, dst, src, size);
1166 osize = t_ax_decrypt (t, dst, &src[1], esize);
1171 GNUNET_break_op (0);
1180 * Pick a connection on which send the next data message.
1182 * @param t Tunnel on which to send the message.
1184 * @return The connection on which to send the next message.
1186 static struct CadetConnection *
1187 tunnel_get_connection (struct CadetTunnel *t)
1189 struct CadetTConnection *iter;
1190 struct CadetConnection *best;
1192 unsigned int lowest_q;
1194 LOG (GNUNET_ERROR_TYPE_DEBUG, "tunnel_get_connection %s\n", GCT_2s (t));
1196 lowest_q = UINT_MAX;
1197 for (iter = t->connection_head; NULL != iter; iter = iter->next)
1199 LOG (GNUNET_ERROR_TYPE_DEBUG, " connection %s: %u\n",
1200 GCC_2s (iter->c), GCC_get_state (iter->c));
1201 if (CADET_CONNECTION_READY == GCC_get_state (iter->c))
1203 qn = GCC_get_qn (iter->c, GCC_is_origin (iter->c, GNUNET_YES));
1204 LOG (GNUNET_ERROR_TYPE_DEBUG, " q_n %u, \n", qn);
1212 LOG (GNUNET_ERROR_TYPE_DEBUG, " selected: connection %s\n", GCC_2s (best));
1218 * Callback called when a queued message is sent.
1220 * Calculates the average time and connection packet tracking.
1222 * @param cls Closure (TunnelQueue handle).
1223 * @param c Connection this message was on.
1224 * @param q Connection queue handle (unused).
1225 * @param type Type of message sent.
1226 * @param fwd Was this a FWD going message?
1227 * @param size Size of the message.
1230 tun_message_sent (void *cls,
1231 struct CadetConnection *c,
1232 struct CadetConnectionQueue *q,
1233 uint16_t type, int fwd, size_t size)
1235 struct CadetTunnelQueue *qt = cls;
1236 struct CadetTunnel *t;
1238 LOG (GNUNET_ERROR_TYPE_DEBUG, "tun_message_sent\n");
1240 GNUNET_assert (NULL != qt->cont);
1241 t = NULL == c ? NULL : GCC_get_tunnel (c);
1242 qt->cont (qt->cont_cls, t, qt, type, size);
1248 count_queued_data (const struct CadetTunnel *t)
1250 struct CadetTunnelDelayed *iter;
1253 for (count = 0, iter = t->tq_head; iter != NULL; iter = iter->next)
1260 * Delete a queued message: either was sent or the channel was destroyed
1261 * before the tunnel's key exchange had a chance to finish.
1263 * @param tqd Delayed queue handle.
1266 unqueue_data (struct CadetTunnelDelayed *tqd)
1268 GNUNET_CONTAINER_DLL_remove (tqd->t->tq_head, tqd->t->tq_tail, tqd);
1274 * Cache a message to be sent once tunnel is online.
1276 * @param t Tunnel to hold the message.
1277 * @param msg Message itself (copy will be made).
1279 static struct CadetTunnelDelayed *
1280 queue_data (struct CadetTunnel *t, const struct GNUNET_MessageHeader *msg)
1282 struct CadetTunnelDelayed *tqd;
1283 uint16_t size = ntohs (msg->size);
1285 LOG (GNUNET_ERROR_TYPE_DEBUG, "queue data on Tunnel %s\n", GCT_2s (t));
1287 GNUNET_assert (GNUNET_NO == is_ready (t));
1289 tqd = GNUNET_malloc (sizeof (struct CadetTunnelDelayed) + size);
1292 GNUNET_memcpy (&tqd[1], msg, size);
1293 GNUNET_CONTAINER_DLL_insert_tail (t->tq_head, t->tq_tail, tqd);
1299 * Sends an already built message on a tunnel, encrypting it and
1300 * choosing the best connection.
1302 * @param message Message to send. Function modifies it.
1303 * @param t Tunnel on which this message is transmitted.
1304 * @param c Connection to use (autoselect if NULL).
1305 * @param force Force the tunnel to take the message (buffer overfill).
1306 * @param cont Continuation to call once message is really sent.
1307 * @param cont_cls Closure for @c cont.
1308 * @param existing_q In case this a transmission of previously queued data,
1309 * this should be TunnelQueue given to the client.
1311 * @return Handle to cancel message.
1312 * NULL if @c cont is NULL or an error happens and message is dropped.
1314 static struct CadetTunnelQueue *
1315 send_prebuilt_message (const struct GNUNET_MessageHeader *message,
1316 struct CadetTunnel *t,
1317 struct CadetConnection *c,
1321 struct CadetTunnelQueue *existing_q)
1323 struct GNUNET_MessageHeader *msg;
1324 struct GNUNET_CADET_Encrypted *ax_msg;
1325 struct CadetTunnelQueue *tq;
1326 size_t size = ntohs (message->size);
1327 char cbuf[sizeof (struct GNUNET_CADET_Encrypted) + size] GNUNET_ALIGN;
1333 LOG (GNUNET_ERROR_TYPE_DEBUG, "GMT Send on Tunnel %s\n", GCT_2s (t));
1335 if (GNUNET_NO == is_ready (t))
1337 struct CadetTunnelDelayed *tqd;
1338 /* A non null existing_q indicates sending of queued data.
1339 * Should only happen after tunnel becomes ready.
1341 GNUNET_assert (NULL == existing_q);
1342 tqd = queue_data (t, message);
1345 tq = GNUNET_new (struct CadetTunnelQueue);
1349 tq->cont_cls = cont_cls;
1353 GNUNET_assert (GNUNET_NO == GCT_is_loopback (t));
1355 ax_msg = (struct GNUNET_CADET_Encrypted *) cbuf;
1356 msg = &ax_msg->header;
1357 msg->size = htons (sizeof (struct GNUNET_CADET_Encrypted) + size);
1358 msg->type = htons (GNUNET_MESSAGE_TYPE_CADET_ENCRYPTED);
1359 esize = t_ax_encrypt (t, &ax_msg[1], message, size);
1360 ax_msg->Ns = htonl (t->ax->Ns++);
1361 ax_msg->PNs = htonl (t->ax->PNs);
1362 GNUNET_CRYPTO_ecdhe_key_get_public (t->ax->DHRs, &ax_msg->DHRs);
1363 t_h_encrypt (t, ax_msg);
1364 t_hmac (&ax_msg->Ns, AX_HEADER_SIZE + esize, 0, &t->ax->HKs, &ax_msg->hmac);
1365 GNUNET_assert (esize == size);
1368 c = tunnel_get_connection (t);
1371 /* Why is tunnel 'ready'? Should have been queued! */
1372 if (NULL != t->destroy_task)
1375 GCT_debug (t, GNUNET_ERROR_TYPE_WARNING);
1377 return NULL; /* Drop... */
1379 fwd = GCC_is_origin (c, GNUNET_YES);
1380 ax_msg->cid = *GCC_get_id (c);
1381 ax_msg->pid = htonl (GCC_get_pid (c, fwd));
1384 type = ntohs (message->type);
1387 case GNUNET_MESSAGE_TYPE_CADET_DATA:
1388 case GNUNET_MESSAGE_TYPE_CADET_DATA_ACK:
1389 if (GNUNET_MESSAGE_TYPE_CADET_DATA == type)
1390 mid = ntohl (((struct GNUNET_CADET_Data *) message)->mid);
1392 mid = ntohl (((struct GNUNET_CADET_DataACK *) message)->mid);
1394 case GNUNET_MESSAGE_TYPE_CADET_KEEPALIVE:
1395 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_CREATE:
1396 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_DESTROY:
1397 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_ACK:
1398 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_NACK:
1402 LOG (GNUNET_ERROR_TYPE_ERROR, "type %s not valid\n", GC_m2s (type));
1404 LOG (GNUNET_ERROR_TYPE_DEBUG, "type %s\n", GC_m2s (type));
1408 (void) GCC_send_prebuilt_message (msg, type, mid, c, fwd,
1412 if (NULL == existing_q)
1414 tq = GNUNET_new (struct CadetTunnelQueue); /* FIXME valgrind: leak*/
1421 tq->cq = GCC_send_prebuilt_message (msg, type, mid, c, fwd, force,
1422 &tun_message_sent, tq);
1423 GNUNET_assert (NULL != tq->cq);
1425 tq->cont_cls = cont_cls;
1432 * Send all cached messages that we can, tunnel is online.
1434 * @param t Tunnel that holds the messages. Cannot be loopback.
1437 send_queued_data (struct CadetTunnel *t)
1439 struct CadetTunnelDelayed *tqd;
1440 struct CadetTunnelDelayed *next;
1443 LOG (GNUNET_ERROR_TYPE_INFO, "Send queued data, tunnel %s\n", GCT_2s (t));
1445 if (GCT_is_loopback (t))
1451 if (GNUNET_NO == is_ready (t))
1453 LOG (GNUNET_ERROR_TYPE_WARNING, " not ready yet: %s/%s\n",
1454 estate2s (t->estate), cstate2s (t->cstate));
1458 room = GCT_get_connections_buffer (t);
1459 LOG (GNUNET_ERROR_TYPE_DEBUG, " buffer space: %u\n", room);
1460 LOG (GNUNET_ERROR_TYPE_DEBUG, " tq head: %p\n", t->tq_head);
1461 for (tqd = t->tq_head; NULL != tqd && room > 0; tqd = next)
1463 LOG (GNUNET_ERROR_TYPE_DEBUG, " sending queued data\n");
1466 send_prebuilt_message ((struct GNUNET_MessageHeader *) &tqd[1],
1467 tqd->t, NULL, GNUNET_YES,
1468 NULL != tqd->tq ? tqd->tq->cont : NULL,
1469 NULL != tqd->tq ? tqd->tq->cont_cls : NULL,
1473 LOG (GNUNET_ERROR_TYPE_DEBUG, "GCT_send_queued_data end\n", GCP_2s (t->peer));
1478 * @brief Resend the KX until we complete the handshake.
1480 * @param cls Closure (tunnel).
1483 kx_resend (void *cls)
1485 struct CadetTunnel *t = cls;
1487 t->rekey_task = NULL;
1488 if (CADET_TUNNEL_KEY_OK == t->estate)
1490 /* Should have been canceled on estate change */
1495 GCT_send_kx (t, CADET_TUNNEL_KEY_SENT >= t->estate);
1500 * Callback called when a queued message is sent.
1502 * @param cls Closure.
1503 * @param c Connection this message was on.
1504 * @param type Type of message sent.
1505 * @param fwd Was this a FWD going message?
1506 * @param size Size of the message.
1509 ephm_sent (void *cls,
1510 struct CadetConnection *c,
1511 struct CadetConnectionQueue *q,
1512 uint16_t type, int fwd, size_t size)
1514 struct CadetTunnel *t = cls;
1515 LOG (GNUNET_ERROR_TYPE_DEBUG, "ephemeral sent %s\n", GC_m2s (type));
1519 if (CADET_TUNNEL_KEY_OK == t->estate)
1522 if (NULL != t->rekey_task)
1525 GCT_debug (t, GNUNET_ERROR_TYPE_WARNING);
1526 GNUNET_SCHEDULER_cancel (t->rekey_task);
1528 t->rekey_task = GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_SECONDS,
1535 * Called only on shutdown, destroy every tunnel.
1537 * @param cls Closure (unused).
1538 * @param key Current public key.
1539 * @param value Value in the hash map (tunnel).
1541 * @return #GNUNET_YES, so we should continue to iterate,
1544 destroy_iterator (void *cls,
1545 const struct GNUNET_PeerIdentity *key,
1548 struct CadetTunnel *t = value;
1550 LOG (GNUNET_ERROR_TYPE_DEBUG,
1551 "GCT_shutdown destroying tunnel at %p\n", t);
1558 * Notify remote peer that we don't know a channel he is talking about,
1559 * probably CHANNEL_DESTROY was missed.
1561 * @param t Tunnel on which to notify.
1562 * @param gid ID of the channel.
1565 send_channel_destroy (struct CadetTunnel *t, unsigned int gid)
1567 struct GNUNET_CADET_ChannelManage msg;
1569 msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_CHANNEL_DESTROY);
1570 msg.header.size = htons (sizeof (msg));
1571 msg.chid = htonl (gid);
1573 LOG (GNUNET_ERROR_TYPE_DEBUG,
1574 "WARNING destroying unknown channel %u on tunnel %s\n",
1576 send_prebuilt_message (&msg.header, t, NULL, GNUNET_YES, NULL, NULL, NULL);
1581 * Demultiplex data per channel and call appropriate channel handler.
1583 * @param t Tunnel on which the data came.
1584 * @param msg Data message.
1585 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
1586 * #GNUNET_YES if message is FWD on the respective channel (loopback)
1587 * #GNUNET_NO if message is BCK on the respective channel (loopback)
1588 * #GNUNET_SYSERR if message on a one-ended channel (remote)
1591 handle_data (struct CadetTunnel *t,
1592 const struct GNUNET_CADET_Data *msg,
1595 struct CadetChannel *ch;
1601 size = ntohs (msg->header.size);
1603 sizeof (struct GNUNET_CADET_Data) +
1604 sizeof (struct GNUNET_MessageHeader))
1609 type = ntohs (msg[1].header.type);
1610 LOG (GNUNET_ERROR_TYPE_DEBUG, " payload of type %s\n", GC_m2s (type));
1611 SPRINTF (buf, "# received payload of type %hu", type);
1612 GNUNET_STATISTICS_update (stats, buf, 1, GNUNET_NO);
1616 ch = GCT_get_channel (t, ntohl (msg->chid));
1619 GNUNET_STATISTICS_update (stats, "# data on unknown channel",
1621 LOG (GNUNET_ERROR_TYPE_DEBUG, "channel 0x%X unknown\n", ntohl (msg->chid));
1622 send_channel_destroy (t, ntohl (msg->chid));
1626 GCCH_handle_data (ch, msg, fwd);
1631 * Demultiplex data ACKs per channel and update appropriate channel buffer info.
1633 * @param t Tunnel on which the DATA ACK came.
1634 * @param msg DATA ACK message.
1635 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
1636 * #GNUNET_YES if message is FWD on the respective channel (loopback)
1637 * #GNUNET_NO if message is BCK on the respective channel (loopback)
1638 * #GNUNET_SYSERR if message on a one-ended channel (remote)
1641 handle_data_ack (struct CadetTunnel *t,
1642 const struct GNUNET_CADET_DataACK *msg,
1645 struct CadetChannel *ch;
1649 size = ntohs (msg->header.size);
1650 if (size != sizeof (struct GNUNET_CADET_DataACK))
1657 ch = GCT_get_channel (t, ntohl (msg->chid));
1660 GNUNET_STATISTICS_update (stats, "# data ack on unknown channel",
1662 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel %u unknown\n",
1667 GCCH_handle_data_ack (ch, msg, fwd);
1672 * Handle channel create.
1674 * @param t Tunnel on which the message came.
1675 * @param msg ChannelCreate message.
1678 handle_ch_create (struct CadetTunnel *t,
1679 const struct GNUNET_CADET_ChannelCreate *msg)
1681 struct CadetChannel *ch;
1685 size = ntohs (msg->header.size);
1686 if (size != sizeof (struct GNUNET_CADET_ChannelCreate))
1688 GNUNET_break_op (0);
1693 ch = GCT_get_channel (t, ntohl (msg->chid));
1694 if (NULL != ch && ! GCT_is_loopback (t))
1696 /* Probably a retransmission, safe to ignore */
1697 LOG (GNUNET_ERROR_TYPE_DEBUG, " already exists...\n");
1699 ch = GCCH_handle_create (t, msg);
1701 GCT_add_channel (t, ch);
1707 * Handle channel NACK: check correctness and call channel handler for NACKs.
1709 * @param t Tunnel on which the NACK came.
1710 * @param msg NACK message.
1713 handle_ch_nack (struct CadetTunnel *t,
1714 const struct GNUNET_CADET_ChannelManage *msg)
1716 struct CadetChannel *ch;
1720 size = ntohs (msg->header.size);
1721 if (size != sizeof (struct GNUNET_CADET_ChannelManage))
1728 ch = GCT_get_channel (t, ntohl (msg->chid));
1731 GNUNET_STATISTICS_update (stats, "# channel NACK on unknown channel",
1733 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel %u unknown\n",
1738 GCCH_handle_nack (ch);
1743 * Handle a CHANNEL ACK (SYNACK/ACK).
1745 * @param t Tunnel on which the CHANNEL ACK came.
1746 * @param msg CHANNEL ACK message.
1747 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
1748 * #GNUNET_YES if message is FWD on the respective channel (loopback)
1749 * #GNUNET_NO if message is BCK on the respective channel (loopback)
1750 * #GNUNET_SYSERR if message on a one-ended channel (remote)
1753 handle_ch_ack (struct CadetTunnel *t,
1754 const struct GNUNET_CADET_ChannelManage *msg,
1757 struct CadetChannel *ch;
1761 size = ntohs (msg->header.size);
1762 if (size != sizeof (struct GNUNET_CADET_ChannelManage))
1769 ch = GCT_get_channel (t, ntohl (msg->chid));
1772 GNUNET_STATISTICS_update (stats, "# channel ack on unknown channel",
1774 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel %u unknown\n",
1779 GCCH_handle_ack (ch, msg, fwd);
1784 * Handle a channel destruction message.
1786 * @param t Tunnel on which the message came.
1787 * @param msg Channel destroy message.
1788 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
1789 * #GNUNET_YES if message is FWD on the respective channel (loopback)
1790 * #GNUNET_NO if message is BCK on the respective channel (loopback)
1791 * #GNUNET_SYSERR if message on a one-ended channel (remote)
1794 handle_ch_destroy (struct CadetTunnel *t,
1795 const struct GNUNET_CADET_ChannelManage *msg,
1798 struct CadetChannel *ch;
1802 size = ntohs (msg->header.size);
1803 if (size != sizeof (struct GNUNET_CADET_ChannelManage))
1810 ch = GCT_get_channel (t, ntohl (msg->chid));
1813 /* Probably a retransmission, safe to ignore */
1817 GCCH_handle_destroy (ch, msg, fwd);
1822 * Free Axolotl data.
1827 destroy_ax (struct CadetTunnel *t)
1832 GNUNET_free_non_null (t->ax->DHRs);
1833 GNUNET_free_non_null (t->ax->kx_0);
1834 while (NULL != t->ax->skipped_head)
1835 delete_skipped_key (t, t->ax->skipped_head);
1836 GNUNET_assert (0 == t->ax->skipped);
1838 GNUNET_free (t->ax);
1841 if (NULL != t->rekey_task)
1843 GNUNET_SCHEDULER_cancel (t->rekey_task);
1844 t->rekey_task = NULL;
1846 if (NULL != t->ephm_h)
1848 GCC_cancel (t->ephm_h);
1855 * Demultiplex by message type and call appropriate handler for a message
1856 * towards a channel of a local tunnel.
1858 * @param t Tunnel this message came on.
1859 * @param msgh Message header.
1860 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
1861 * #GNUNET_YES if message is FWD on the respective channel (loopback)
1862 * #GNUNET_NO if message is BCK on the respective channel (loopback)
1863 * #GNUNET_SYSERR if message on a one-ended channel (remote)
1866 handle_decrypted (struct CadetTunnel *t,
1867 const struct GNUNET_MessageHeader *msgh,
1873 type = ntohs (msgh->type);
1874 LOG (GNUNET_ERROR_TYPE_DEBUG, "<-- %s on %s\n", GC_m2s (type), GCT_2s (t));
1875 SPRINTF (buf, "# received encrypted of type %hu (%s)", type, GC_m2s (type));
1876 GNUNET_STATISTICS_update (stats, buf, 1, GNUNET_NO);
1880 case GNUNET_MESSAGE_TYPE_CADET_KEEPALIVE:
1881 /* Do nothing, connection aleady got updated. */
1882 GNUNET_STATISTICS_update (stats, "# keepalives received", 1, GNUNET_NO);
1885 case GNUNET_MESSAGE_TYPE_CADET_DATA:
1886 /* Don't send hop ACK, wait for client to ACK */
1887 handle_data (t, (struct GNUNET_CADET_Data *) msgh, fwd);
1890 case GNUNET_MESSAGE_TYPE_CADET_DATA_ACK:
1891 handle_data_ack (t, (struct GNUNET_CADET_DataACK *) msgh, fwd);
1894 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_CREATE:
1895 handle_ch_create (t, (struct GNUNET_CADET_ChannelCreate *) msgh);
1898 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_NACK:
1899 handle_ch_nack (t, (struct GNUNET_CADET_ChannelManage *) msgh);
1902 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_ACK:
1903 handle_ch_ack (t, (struct GNUNET_CADET_ChannelManage *) msgh, fwd);
1906 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_DESTROY:
1907 handle_ch_destroy (t, (struct GNUNET_CADET_ChannelManage *) msgh, fwd);
1911 GNUNET_break_op (0);
1912 LOG (GNUNET_ERROR_TYPE_WARNING,
1913 "end-to-end message not known (%u)\n",
1914 ntohs (msgh->type));
1915 GCT_debug (t, GNUNET_ERROR_TYPE_WARNING);
1920 /******************************************************************************/
1921 /******************************** API ***********************************/
1922 /******************************************************************************/
1925 * Decrypt and process an encrypted message.
1927 * Calls the appropriate handler for a message in a channel of a local tunnel.
1929 * @param t Tunnel this message came on.
1930 * @param msg Message header.
1933 GCT_handle_encrypted (struct CadetTunnel *t,
1934 const struct GNUNET_CADET_Encrypted *msg)
1936 uint16_t size = ntohs (msg->header.size);
1939 const struct GNUNET_MessageHeader *msgh;
1942 GNUNET_STATISTICS_update (stats, "# received encrypted", 1, GNUNET_NO);
1944 decrypted_size = t_ax_decrypt_and_validate (t, cbuf, msg, size);
1946 if (-1 == decrypted_size)
1948 GNUNET_STATISTICS_update (stats, "# unable to decrypt", 1, GNUNET_NO);
1949 if (CADET_TUNNEL_KEY_PING <= t->estate)
1951 GNUNET_break_op (0);
1952 LOG (GNUNET_ERROR_TYPE_WARNING, "Wrong crypto, tunnel %s\n", GCT_2s (t));
1953 GCT_debug (t, GNUNET_ERROR_TYPE_WARNING);
1957 GCT_change_estate (t, CADET_TUNNEL_KEY_OK);
1959 /* FIXME: this is bad, as the structs returned from
1960 this loop may be unaligned, see util's MST for
1961 how to do this right. */
1963 while (off + sizeof (struct GNUNET_MessageHeader) <= decrypted_size)
1967 msgh = (const struct GNUNET_MessageHeader *) &cbuf[off];
1968 msize = ntohs (msgh->size);
1969 if (msize < sizeof (struct GNUNET_MessageHeader))
1971 GNUNET_break_op (0);
1974 if (off + msize < decrypted_size)
1976 GNUNET_break_op (0);
1979 handle_decrypted (t, msgh, GNUNET_SYSERR);
1986 * Handle a Key eXchange message.
1988 * @param t Tunnel on which the message came.
1989 * @param msg KX message itself.
1992 GCT_handle_kx (struct CadetTunnel *t,
1993 const struct GNUNET_CADET_KX *msg)
1995 struct CadetTunnelAxolotl *ax;
1996 struct GNUNET_HashCode key_material[3];
1997 struct GNUNET_CRYPTO_SymmetricSessionKey keys[5];
1998 const char salt[] = "CADET Axolotl salt";
1999 const struct GNUNET_PeerIdentity *pid;
2004 LOG (GNUNET_ERROR_TYPE_INFO, "<== { KX} on %s\n", GCT_2s (t));
2008 /* Something is wrong if ax is NULL. Whose fault it is? */
2013 pid = GCT_get_destination (t);
2014 if (0 > GNUNET_CRYPTO_cmp_peer_identity (&my_full_id, pid))
2015 am_I_alice = GNUNET_YES;
2016 else if (0 < GNUNET_CRYPTO_cmp_peer_identity (&my_full_id, pid))
2017 am_I_alice = GNUNET_NO;
2020 GNUNET_break_op (0);
2024 if (0 != (GNUNET_CADET_KX_FLAG_FORCE_REPLY & ntohl (msg->flags)))
2026 if (NULL != t->rekey_task)
2028 GNUNET_SCHEDULER_cancel (t->rekey_task);
2029 t->rekey_task = NULL;
2031 GCT_send_kx (t, GNUNET_NO);
2034 if (0 == memcmp (&ax->DHRr, &msg->ratchet_key, sizeof(msg->ratchet_key)))
2036 LOG (GNUNET_ERROR_TYPE_INFO, " known ratchet key, exit\n");
2040 LOG (GNUNET_ERROR_TYPE_INFO, " is Alice? %s\n", am_I_alice ? "YES" : "NO");
2042 ax->DHRr = msg->ratchet_key;
2045 if (GNUNET_YES == am_I_alice)
2047 GNUNET_CRYPTO_eddsa_ecdh (id_key, /* A */
2048 &msg->ephemeral_key, /* B0 */
2053 GNUNET_CRYPTO_ecdh_eddsa (ax->kx_0, /* B0 */
2054 &pid->public_key, /* A */
2059 if (GNUNET_YES == am_I_alice)
2061 GNUNET_CRYPTO_ecdh_eddsa (ax->kx_0, /* A0 */
2062 &pid->public_key, /* B */
2067 GNUNET_CRYPTO_eddsa_ecdh (id_key, /* A */
2068 &msg->ephemeral_key, /* B0 */
2075 /* (This is the triple-DH, we could probably safely skip this,
2076 as A0/B0 are already in the key material.) */
2077 GNUNET_CRYPTO_ecc_ecdh (ax->kx_0, /* A0 or B0 */
2078 &msg->ephemeral_key, /* B0 or A0 */
2081 #if DUMP_KEYS_TO_STDERR
2084 for (i = 0; i < 3; i++)
2085 LOG (GNUNET_ERROR_TYPE_INFO, "km[%u]: %s\n",
2086 i, GNUNET_h2s (&key_material[i]));
2091 GNUNET_CRYPTO_kdf (keys, sizeof (keys),
2092 salt, sizeof (salt),
2093 &key_material, sizeof (key_material), NULL);
2095 if (0 == memcmp (&ax->RK, &keys[0], sizeof(ax->RK)))
2097 LOG (GNUNET_ERROR_TYPE_INFO, " known handshake key, exit\n");
2101 if (GNUNET_YES == am_I_alice)
2107 ax->ratchet_flag = GNUNET_YES;
2115 ax->ratchet_flag = GNUNET_NO;
2116 ax->ratchet_allowed = GNUNET_NO;
2117 ax->ratchet_counter = 0;
2118 ax->ratchet_expiration =
2119 GNUNET_TIME_absolute_add (GNUNET_TIME_absolute_get(), ratchet_time);
2125 GCT_change_estate (t, CADET_TUNNEL_KEY_PING);
2126 send_queued_data (t);
2132 * Initialize the tunnel subsystem.
2134 * @param c Configuration handle.
2135 * @param key ECC private key, to derive all other keys and do crypto.
2138 GCT_init (const struct GNUNET_CONFIGURATION_Handle *c,
2139 const struct GNUNET_CRYPTO_EddsaPrivateKey *key)
2141 unsigned int expected_overhead;
2143 LOG (GNUNET_ERROR_TYPE_DEBUG, "init\n");
2145 expected_overhead = 0;
2146 expected_overhead += sizeof (struct GNUNET_CADET_Encrypted);
2147 expected_overhead += sizeof (struct GNUNET_CADET_Data);
2148 expected_overhead += sizeof (struct GNUNET_CADET_ACK);
2149 GNUNET_assert (GNUNET_CONSTANTS_CADET_P2P_OVERHEAD == expected_overhead);
2152 GNUNET_CONFIGURATION_get_value_number (c,
2157 GNUNET_log_config_invalid (GNUNET_ERROR_TYPE_WARNING,
2161 ratchet_messages = 64;
2164 GNUNET_CONFIGURATION_get_value_time (c,
2169 GNUNET_log_config_invalid (GNUNET_ERROR_TYPE_WARNING,
2170 "CADET", "RATCHET_TIME", "USING DEFAULT");
2171 ratchet_time = GNUNET_TIME_UNIT_HOURS;
2176 tunnels = GNUNET_CONTAINER_multipeermap_create (128, GNUNET_YES);
2181 * Shut down the tunnel subsystem.
2186 LOG (GNUNET_ERROR_TYPE_DEBUG, "Shutting down tunnels\n");
2187 GNUNET_CONTAINER_multipeermap_iterate (tunnels, &destroy_iterator, NULL);
2188 GNUNET_CONTAINER_multipeermap_destroy (tunnels);
2195 * @param destination Peer this tunnel is towards.
2197 struct CadetTunnel *
2198 GCT_new (struct CadetPeer *destination)
2200 struct CadetTunnel *t;
2202 t = GNUNET_new (struct CadetTunnel);
2204 t->peer = destination;
2207 GNUNET_CONTAINER_multipeermap_put (tunnels, GCP_get_id (destination), t,
2208 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_FAST))
2214 t->ax = GNUNET_new (struct CadetTunnelAxolotl);
2216 t->ax->kx_0 = GNUNET_CRYPTO_ecdhe_key_create ();
2222 * Change the tunnel's connection state.
2224 * @param t Tunnel whose connection state to change.
2225 * @param cstate New connection state.
2228 GCT_change_cstate (struct CadetTunnel* t, enum CadetTunnelCState cstate)
2232 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel %s cstate %s => %s\n",
2233 GCP_2s (t->peer), cstate2s (t->cstate), cstate2s (cstate));
2234 if (myid != GCP_get_short_id (t->peer) &&
2235 CADET_TUNNEL_READY != t->cstate &&
2236 CADET_TUNNEL_READY == cstate)
2239 if (CADET_TUNNEL_KEY_OK == t->estate)
2241 LOG (GNUNET_ERROR_TYPE_DEBUG, " cstate triggered send queued data\n");
2242 send_queued_data (t);
2244 else if (CADET_TUNNEL_KEY_UNINITIALIZED == t->estate)
2246 LOG (GNUNET_ERROR_TYPE_DEBUG, " cstate triggered KX\n");
2247 GCT_send_kx (t, GNUNET_NO);
2251 LOG (GNUNET_ERROR_TYPE_DEBUG, "estate %s\n", estate2s (t->estate));
2256 if (CADET_TUNNEL_READY == cstate
2257 && CONNECTIONS_PER_TUNNEL <= GCT_count_connections (t))
2259 LOG (GNUNET_ERROR_TYPE_DEBUG, " cstate triggered stop dht\n");
2260 GCP_stop_search (t->peer);
2266 * Change the tunnel encryption state.
2268 * If the encryption state changes to OK, stop the rekey task.
2270 * @param t Tunnel whose encryption state to change, or NULL.
2271 * @param state New encryption state.
2274 GCT_change_estate (struct CadetTunnel* t, enum CadetTunnelEState state)
2276 enum CadetTunnelEState old;
2283 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel %s estate was %s\n",
2284 GCP_2s (t->peer), estate2s (old));
2285 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel %s estate is now %s\n",
2286 GCP_2s (t->peer), estate2s (t->estate));
2288 if (CADET_TUNNEL_KEY_OK != old && CADET_TUNNEL_KEY_OK == t->estate)
2290 if (NULL != t->rekey_task)
2292 GNUNET_SCHEDULER_cancel (t->rekey_task);
2293 t->rekey_task = NULL;
2295 /* Send queued data if tunnel is not loopback */
2296 if (myid != GCP_get_short_id (t->peer))
2297 send_queued_data (t);
2303 * @brief Check if tunnel has too many connections, and remove one if necessary.
2305 * Currently this means the newest connection, unless it is a direct one.
2306 * Implemented as a task to avoid freeing a connection that is in the middle
2307 * of being created/processed.
2309 * @param cls Closure (Tunnel to check).
2312 trim_connections (void *cls)
2314 struct CadetTunnel *t = cls;
2316 t->trim_connections_task = NULL;
2317 if (GCT_count_connections (t) > 2 * CONNECTIONS_PER_TUNNEL)
2319 struct CadetTConnection *iter;
2320 struct CadetTConnection *c;
2322 for (c = iter = t->connection_head; NULL != iter; iter = iter->next)
2324 if ((iter->created.abs_value_us > c->created.abs_value_us)
2325 && GNUNET_NO == GCC_is_direct (iter->c))
2332 LOG (GNUNET_ERROR_TYPE_DEBUG, "Too many connections on tunnel %s\n",
2334 LOG (GNUNET_ERROR_TYPE_DEBUG, "Destroying connection %s\n",
2347 * Add a connection to a tunnel.
2350 * @param c Connection.
2353 GCT_add_connection (struct CadetTunnel *t, struct CadetConnection *c)
2355 struct CadetTConnection *aux;
2357 GNUNET_assert (NULL != c);
2359 LOG (GNUNET_ERROR_TYPE_DEBUG, "add connection %s\n", GCC_2s (c));
2360 LOG (GNUNET_ERROR_TYPE_DEBUG, " to tunnel %s\n", GCT_2s (t));
2361 for (aux = t->connection_head; aux != NULL; aux = aux->next)
2365 aux = GNUNET_new (struct CadetTConnection);
2367 aux->created = GNUNET_TIME_absolute_get ();
2369 GNUNET_CONTAINER_DLL_insert (t->connection_head, t->connection_tail, aux);
2371 if (CADET_TUNNEL_SEARCHING == t->cstate)
2372 GCT_change_cstate (t, CADET_TUNNEL_WAITING);
2374 if (NULL != t->trim_connections_task)
2375 t->trim_connections_task = GNUNET_SCHEDULER_add_now (&trim_connections, t);
2380 * Remove a connection from a tunnel.
2383 * @param c Connection.
2386 GCT_remove_connection (struct CadetTunnel *t,
2387 struct CadetConnection *c)
2389 struct CadetTConnection *aux;
2390 struct CadetTConnection *next;
2393 LOG (GNUNET_ERROR_TYPE_DEBUG, "Removing connection %s from tunnel %s\n",
2394 GCC_2s (c), GCT_2s (t));
2395 for (aux = t->connection_head; aux != NULL; aux = next)
2400 GNUNET_CONTAINER_DLL_remove (t->connection_head, t->connection_tail, aux);
2405 conns = GCT_count_connections (t);
2407 && NULL == t->destroy_task
2408 && CADET_TUNNEL_SHUTDOWN != t->cstate
2409 && GNUNET_NO == shutting_down)
2411 if (0 == GCT_count_any_connections (t))
2412 GCT_change_cstate (t, CADET_TUNNEL_SEARCHING);
2414 GCT_change_cstate (t, CADET_TUNNEL_WAITING);
2417 /* Start new connections if needed */
2418 if (CONNECTIONS_PER_TUNNEL > conns
2419 && CADET_TUNNEL_SHUTDOWN != t->cstate
2420 && GNUNET_NO == shutting_down)
2422 LOG (GNUNET_ERROR_TYPE_DEBUG, " too few connections, getting new ones\n");
2423 GCP_connect (t->peer); /* Will change cstate to WAITING when possible */
2427 /* If not marked as ready, no change is needed */
2428 if (CADET_TUNNEL_READY != t->cstate)
2431 /* Check if any connection is ready to maintain cstate */
2432 for (aux = t->connection_head; aux != NULL; aux = aux->next)
2433 if (CADET_CONNECTION_READY == GCC_get_state (aux->c))
2439 * Add a channel to a tunnel.
2442 * @param ch Channel.
2445 GCT_add_channel (struct CadetTunnel *t, struct CadetChannel *ch)
2447 struct CadetTChannel *aux;
2449 GNUNET_assert (NULL != ch);
2451 LOG (GNUNET_ERROR_TYPE_DEBUG, "Adding channel %p to tunnel %p\n", ch, t);
2453 for (aux = t->channel_head; aux != NULL; aux = aux->next)
2455 LOG (GNUNET_ERROR_TYPE_DEBUG, " already there %p\n", aux->ch);
2460 aux = GNUNET_new (struct CadetTChannel);
2462 LOG (GNUNET_ERROR_TYPE_DEBUG,
2463 " adding %p to %p\n", aux, t->channel_head);
2464 GNUNET_CONTAINER_DLL_insert_tail (t->channel_head,
2468 if (NULL != t->destroy_task)
2470 GNUNET_SCHEDULER_cancel (t->destroy_task);
2471 t->destroy_task = NULL;
2472 LOG (GNUNET_ERROR_TYPE_DEBUG, " undo destroy!\n");
2478 * Remove a channel from a tunnel.
2481 * @param ch Channel.
2484 GCT_remove_channel (struct CadetTunnel *t, struct CadetChannel *ch)
2486 struct CadetTChannel *aux;
2488 LOG (GNUNET_ERROR_TYPE_DEBUG, "Removing channel %p from tunnel %p\n", ch, t);
2489 for (aux = t->channel_head; aux != NULL; aux = aux->next)
2493 LOG (GNUNET_ERROR_TYPE_DEBUG, " found! %s\n", GCCH_2s (ch));
2494 GNUNET_CONTAINER_DLL_remove (t->channel_head,
2505 * Search for a channel by global ID.
2507 * @param t Tunnel containing the channel.
2508 * @param chid Public channel number.
2510 * @return channel handler, NULL if doesn't exist
2512 struct CadetChannel *
2513 GCT_get_channel (struct CadetTunnel *t, CADET_ChannelNumber chid)
2515 struct CadetTChannel *iter;
2520 for (iter = t->channel_head; NULL != iter; iter = iter->next)
2522 if (GCCH_get_id (iter->ch) == chid)
2526 return NULL == iter ? NULL : iter->ch;
2531 * @brief Destroy a tunnel and free all resources.
2533 * Should only be called a while after the tunnel has been marked as destroyed,
2534 * in case there is a new channel added to the same peer shortly after marking
2535 * the tunnel. This way we avoid a new public key handshake.
2537 * @param cls Closure (tunnel to destroy).
2540 delayed_destroy (void *cls)
2542 struct CadetTunnel *t = cls;
2543 struct CadetTConnection *iter;
2545 t->destroy_task = NULL;
2546 LOG (GNUNET_ERROR_TYPE_DEBUG,
2547 "delayed destroying tunnel %p\n",
2549 t->cstate = CADET_TUNNEL_SHUTDOWN;
2550 for (iter = t->connection_head; NULL != iter; iter = iter->next)
2552 GCC_send_destroy (iter->c);
2559 * Tunnel is empty: destroy it.
2561 * Notifies all connections about the destruction.
2563 * @param t Tunnel to destroy.
2566 GCT_destroy_empty (struct CadetTunnel *t)
2568 if (GNUNET_YES == shutting_down)
2569 return; /* Will be destroyed immediately anyway */
2571 if (NULL != t->destroy_task)
2573 LOG (GNUNET_ERROR_TYPE_WARNING,
2574 "Tunnel %s is already scheduled for destruction. Tunnel debug dump:\n",
2576 GCT_debug (t, GNUNET_ERROR_TYPE_WARNING);
2578 /* should never happen, tunnel can only become empty once, and the
2579 * task identifier should be NO_TASK (cleaned when the tunnel was created
2580 * or became un-empty)
2585 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel %s empty: scheduling destruction\n",
2588 // FIXME make delay a config option
2589 t->destroy_task = GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_MINUTES,
2590 &delayed_destroy, t);
2591 LOG (GNUNET_ERROR_TYPE_DEBUG, "Scheduled destroy of %p as %p\n",
2592 t, t->destroy_task);
2597 * Destroy tunnel if empty (no more channels).
2599 * @param t Tunnel to destroy if empty.
2602 GCT_destroy_if_empty (struct CadetTunnel *t)
2604 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel %s destroy if empty\n", GCT_2s (t));
2605 if (0 < GCT_count_channels (t))
2608 GCT_destroy_empty (t);
2613 * Destroy the tunnel.
2615 * This function does not generate any warning traffic to clients or peers.
2618 * Cancel messages belonging to this tunnel queued to neighbors.
2619 * Free any allocated resources linked to the tunnel.
2621 * @param t The tunnel to destroy.
2624 GCT_destroy (struct CadetTunnel *t)
2626 struct CadetTConnection *iter_c;
2627 struct CadetTConnection *next_c;
2628 struct CadetTChannel *iter_ch;
2629 struct CadetTChannel *next_ch;
2630 unsigned int keepalives_queued;
2635 LOG (GNUNET_ERROR_TYPE_DEBUG,
2636 "destroying tunnel %s\n",
2638 GNUNET_break (GNUNET_YES ==
2639 GNUNET_CONTAINER_multipeermap_remove (tunnels,
2640 GCP_get_id (t->peer), t));
2642 for (iter_c = t->connection_head; NULL != iter_c; iter_c = next_c)
2644 next_c = iter_c->next;
2645 GCC_destroy (iter_c->c);
2647 for (iter_ch = t->channel_head; NULL != iter_ch; iter_ch = next_ch)
2649 next_ch = iter_ch->next;
2650 GCCH_destroy (iter_ch->ch);
2651 /* Should only happen on shutdown, but it's ok. */
2653 keepalives_queued = 0;
2654 while (NULL != t->tq_head)
2656 /* Should have been cleaned by destuction of channel. */
2657 struct GNUNET_MessageHeader *mh;
2660 mh = (struct GNUNET_MessageHeader *) &t->tq_head[1];
2661 type = ntohs (mh->type);
2662 if (0 == keepalives_queued && GNUNET_MESSAGE_TYPE_CADET_KEEPALIVE == type)
2664 keepalives_queued = 1;
2665 LOG (GNUNET_ERROR_TYPE_DEBUG,
2666 "one keepalive left behind on tunnel shutdown\n");
2668 else if (GNUNET_MESSAGE_TYPE_CADET_CHANNEL_DESTROY == type)
2670 LOG (GNUNET_ERROR_TYPE_WARNING,
2671 "tunnel destroyed before a CHANNEL_DESTROY was sent to peer\n");
2676 LOG (GNUNET_ERROR_TYPE_ERROR,
2677 "message left behind on tunnel shutdown: %s\n",
2680 unqueue_data (t->tq_head);
2684 if (NULL != t->destroy_task)
2686 LOG (GNUNET_ERROR_TYPE_DEBUG,
2687 "cancelling dest: %p\n",
2689 GNUNET_SCHEDULER_cancel (t->destroy_task);
2690 t->destroy_task = NULL;
2693 if (NULL != t->trim_connections_task)
2695 LOG (GNUNET_ERROR_TYPE_DEBUG, "cancelling trim: %p\n",
2696 t->trim_connections_task);
2697 GNUNET_SCHEDULER_cancel (t->trim_connections_task);
2698 t->trim_connections_task = NULL;
2701 GNUNET_STATISTICS_update (stats, "# tunnels", -1, GNUNET_NO);
2702 GCP_set_tunnel (t->peer, NULL);
2704 if (NULL != t->rekey_task)
2706 GNUNET_SCHEDULER_cancel (t->rekey_task);
2707 t->rekey_task = NULL;
2717 * @brief Use the given path for the tunnel.
2718 * Update the next and prev hops (and RCs).
2719 * (Re)start the path refresh in case the tunnel is locally owned.
2721 * @param t Tunnel to update.
2722 * @param p Path to use.
2724 * @return Connection created.
2726 struct CadetConnection *
2727 GCT_use_path (struct CadetTunnel *t, struct CadetPeerPath *path)
2729 struct CadetConnection *c;
2730 struct GNUNET_CADET_Hash cid;
2731 unsigned int own_pos;
2733 if (NULL == t || NULL == path)
2739 if (CADET_TUNNEL_SHUTDOWN == t->cstate)
2745 for (own_pos = 0; own_pos < path->length; own_pos++)
2747 if (path->peers[own_pos] == myid)
2750 if (own_pos >= path->length)
2752 GNUNET_break_op (0);
2756 GNUNET_CRYPTO_random_block (GNUNET_CRYPTO_QUALITY_NONCE, &cid, sizeof (cid));
2757 c = GCC_new (&cid, t, path, own_pos);
2760 /* Path was flawed */
2763 GCT_add_connection (t, c);
2769 * Count all created connections of a tunnel. Not necessarily ready connections!
2771 * @param t Tunnel on which to count.
2773 * @return Number of connections created, either being established or ready.
2776 GCT_count_any_connections (struct CadetTunnel *t)
2778 struct CadetTConnection *iter;
2784 for (count = 0, iter = t->connection_head; NULL != iter; iter = iter->next)
2792 * Count established (ready) connections of a tunnel.
2794 * @param t Tunnel on which to count.
2796 * @return Number of connections.
2799 GCT_count_connections (struct CadetTunnel *t)
2801 struct CadetTConnection *iter;
2807 for (count = 0, iter = t->connection_head; NULL != iter; iter = iter->next)
2808 if (CADET_CONNECTION_READY == GCC_get_state (iter->c))
2816 * Count channels of a tunnel.
2818 * @param t Tunnel on which to count.
2820 * @return Number of channels.
2823 GCT_count_channels (struct CadetTunnel *t)
2825 struct CadetTChannel *iter;
2828 for (count = 0, iter = t->channel_head;
2830 iter = iter->next, count++) /* skip */;
2837 * Get the connectivity state of a tunnel.
2841 * @return Tunnel's connectivity state.
2843 enum CadetTunnelCState
2844 GCT_get_cstate (struct CadetTunnel *t)
2849 return (enum CadetTunnelCState) -1;
2856 * Get the encryption state of a tunnel.
2860 * @return Tunnel's encryption state.
2862 enum CadetTunnelEState
2863 GCT_get_estate (struct CadetTunnel *t)
2868 return (enum CadetTunnelEState) -1;
2874 * Get the maximum buffer space for a tunnel towards a local client.
2878 * @return Biggest buffer space offered by any channel in the tunnel.
2881 GCT_get_channels_buffer (struct CadetTunnel *t)
2883 struct CadetTChannel *iter;
2884 unsigned int buffer;
2885 unsigned int ch_buf;
2887 if (NULL == t->channel_head)
2889 /* Probably getting buffer for a channel create/handshake. */
2890 LOG (GNUNET_ERROR_TYPE_DEBUG, " no channels, allow max\n");
2891 return MIN_TUNNEL_BUFFER;
2895 for (iter = t->channel_head; NULL != iter; iter = iter->next)
2897 ch_buf = get_channel_buffer (iter);
2898 if (ch_buf > buffer)
2901 if (MIN_TUNNEL_BUFFER > buffer)
2902 return MIN_TUNNEL_BUFFER;
2904 if (MAX_TUNNEL_BUFFER < buffer)
2907 return MAX_TUNNEL_BUFFER;
2914 * Get the total buffer space for a tunnel for P2P traffic.
2918 * @return Buffer space offered by all connections in the tunnel.
2921 GCT_get_connections_buffer (struct CadetTunnel *t)
2923 struct CadetTConnection *iter;
2924 unsigned int buffer;
2926 if (GNUNET_NO == is_ready (t))
2928 if (count_queued_data (t) >= 3)
2935 for (iter = t->connection_head; NULL != iter; iter = iter->next)
2937 if (GCC_get_state (iter->c) != CADET_CONNECTION_READY)
2941 buffer += get_connection_buffer (iter);
2949 * Get the tunnel's destination.
2953 * @return ID of the destination peer.
2955 const struct GNUNET_PeerIdentity *
2956 GCT_get_destination (struct CadetTunnel *t)
2958 return GCP_get_id (t->peer);
2963 * Get the tunnel's next free global channel ID.
2967 * @return GID of a channel free to use.
2970 GCT_get_next_chid (struct CadetTunnel *t)
2972 CADET_ChannelNumber chid;
2973 CADET_ChannelNumber mask;
2976 /* Set bit 30 depending on the ID relationship. Bit 31 is always 0 for GID.
2977 * If our ID is bigger or loopback tunnel, start at 0, bit 30 = 0
2978 * If peer's ID is bigger, start at 0x4... bit 30 = 1
2980 result = GNUNET_CRYPTO_cmp_peer_identity (&my_full_id, GCP_get_id (t->peer));
2985 t->next_chid |= mask;
2987 while (NULL != GCT_get_channel (t, t->next_chid))
2989 LOG (GNUNET_ERROR_TYPE_DEBUG, "Channel %u exists...\n", t->next_chid);
2990 t->next_chid = (t->next_chid + 1) & ~GNUNET_CADET_LOCAL_CHANNEL_ID_CLI;
2991 t->next_chid |= mask;
2993 chid = t->next_chid;
2994 t->next_chid = (t->next_chid + 1) & ~GNUNET_CADET_LOCAL_CHANNEL_ID_CLI;
2995 t->next_chid |= mask;
3002 * Send ACK on one or more channels due to buffer in connections.
3004 * @param t Channel which has some free buffer space.
3007 GCT_unchoke_channels (struct CadetTunnel *t)
3009 struct CadetTChannel *iter;
3010 unsigned int buffer;
3011 unsigned int channels = GCT_count_channels (t);
3012 unsigned int choked_n;
3013 struct CadetChannel *choked[channels];
3015 LOG (GNUNET_ERROR_TYPE_DEBUG, "GCT_unchoke_channels on %s\n", GCT_2s (t));
3016 LOG (GNUNET_ERROR_TYPE_DEBUG, " head: %p\n", t->channel_head);
3017 if (NULL != t->channel_head)
3018 LOG (GNUNET_ERROR_TYPE_DEBUG, " head ch: %p\n", t->channel_head->ch);
3020 if (NULL != t->tq_head)
3021 send_queued_data (t);
3023 /* Get buffer space */
3024 buffer = GCT_get_connections_buffer (t);
3030 /* Count and remember choked channels */
3032 for (iter = t->channel_head; NULL != iter; iter = iter->next)
3034 if (GNUNET_NO == get_channel_allowed (iter))
3036 choked[choked_n++] = iter->ch;
3040 /* Unchoke random channels */
3041 while (0 < buffer && 0 < choked_n)
3043 unsigned int r = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK,
3045 GCCH_allow_client (choked[r], GCCH_is_origin (choked[r], GNUNET_YES));
3048 choked[r] = choked[choked_n];
3054 * Send ACK on one or more connections due to buffer space to the client.
3056 * Iterates all connections of the tunnel and sends ACKs appropriately.
3061 GCT_send_connection_acks (struct CadetTunnel *t)
3063 struct CadetTConnection *iter;
3066 uint32_t allow_per_connection;
3068 unsigned int buffer;
3070 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel send connection ACKs on %s\n",
3079 if (CADET_TUNNEL_READY != t->cstate)
3082 buffer = GCT_get_channels_buffer (t);
3083 LOG (GNUNET_ERROR_TYPE_DEBUG, " buffer %u\n", buffer);
3085 /* Count connections, how many messages are already allowed */
3086 cs = GCT_count_connections (t);
3087 for (allowed = 0, iter = t->connection_head; NULL != iter; iter = iter->next)
3089 allowed += get_connection_allowed (iter);
3091 LOG (GNUNET_ERROR_TYPE_DEBUG, " allowed %u\n", allowed);
3093 /* Make sure there is no overflow */
3094 if (allowed > buffer)
3097 /* Authorize connections to send more data */
3098 to_allow = buffer - allowed;
3100 for (iter = t->connection_head;
3101 NULL != iter && to_allow > 0;
3104 if (CADET_CONNECTION_READY != GCC_get_state (iter->c)
3105 || get_connection_allowed (iter) > 64 / 3)
3109 GNUNET_assert(cs != 0);
3110 allow_per_connection = to_allow/cs;
3111 to_allow -= allow_per_connection;
3113 GCC_allow (iter->c, allow_per_connection,
3114 GCC_is_origin (iter->c, GNUNET_NO));
3119 /* Since we don't allow if it's allowed to send 64/3, this can happen. */
3120 LOG (GNUNET_ERROR_TYPE_DEBUG, " reminding to_allow: %u\n", to_allow);
3126 * Cancel a previously sent message while it's in the queue.
3128 * ONLY can be called before the continuation given to the send function
3129 * is called. Once the continuation is called, the message is no longer in the
3132 * @param q Handle to the queue.
3135 GCT_cancel (struct CadetTunnelQueue *q)
3139 GNUNET_assert (NULL == q->tqd);
3141 /* tun_message_sent() will be called and free q */
3143 else if (NULL != q->tqd)
3145 unqueue_data (q->tqd);
3147 if (NULL != q->cont)
3148 q->cont (q->cont_cls, NULL, q, 0, 0);
3159 * Check if the tunnel has queued traffic.
3161 * @param t Tunnel to check.
3163 * @return #GNUNET_YES if there is queued traffic
3164 * #GNUNET_NO otherwise
3167 GCT_has_queued_traffic (struct CadetTunnel *t)
3169 return (NULL != t->tq_head) ? GNUNET_YES : GNUNET_NO;
3174 * Sends an already built message on a tunnel, encrypting it and
3175 * choosing the best connection if not provided.
3177 * @param message Message to send. Function modifies it.
3178 * @param t Tunnel on which this message is transmitted.
3179 * @param c Connection to use (autoselect if NULL).
3180 * @param force Force the tunnel to take the message (buffer overfill).
3181 * @param cont Continuation to call once message is really sent.
3182 * @param cont_cls Closure for @c cont.
3184 * @return Handle to cancel message. NULL if @c cont is NULL.
3186 struct CadetTunnelQueue *
3187 GCT_send_prebuilt_message (const struct GNUNET_MessageHeader *message,
3188 struct CadetTunnel *t, struct CadetConnection *c,
3189 int force, GCT_sent cont, void *cont_cls)
3191 return send_prebuilt_message (message, t, c, force, cont, cont_cls, NULL);
3196 * Send a KX message.
3198 * @param t Tunnel on which to send it.
3199 * @param force_reply Force the other peer to reply with a KX message.
3202 GCT_send_kx (struct CadetTunnel *t, int force_reply)
3204 struct CadetConnection *c;
3205 struct GNUNET_CADET_KX msg;
3206 enum GNUNET_CADET_KX_Flags flags;
3208 LOG (GNUNET_ERROR_TYPE_INFO, "==> { KX} on %s\n", GCT_2s (t));
3209 if (NULL != t->ephm_h)
3211 LOG (GNUNET_ERROR_TYPE_INFO, " already queued, nop\n");
3214 GNUNET_assert (GNUNET_NO == GCT_is_loopback (t));
3216 c = tunnel_get_connection (t);
3219 if (NULL == t->destroy_task && CADET_TUNNEL_READY == t->cstate)
3222 GCT_debug (t, GNUNET_ERROR_TYPE_ERROR);
3227 msg.header.size = htons (sizeof (msg));
3228 msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_KX);
3229 flags = GNUNET_CADET_KX_FLAG_NONE;
3230 if (GNUNET_YES == force_reply)
3231 flags |= GNUNET_CADET_KX_FLAG_FORCE_REPLY;
3232 msg.flags = htonl (flags);
3233 msg.cid = *GCC_get_id (c);
3234 GNUNET_CRYPTO_ecdhe_key_get_public (t->ax->kx_0, &msg.ephemeral_key);
3235 GNUNET_CRYPTO_ecdhe_key_get_public (t->ax->DHRs, &msg.ratchet_key);
3237 t->ephm_h = GCC_send_prebuilt_message (&msg.header, UINT16_MAX, 0,
3238 c, GCC_is_origin (c, GNUNET_YES),
3239 GNUNET_YES, &ephm_sent, t);
3240 if (CADET_TUNNEL_KEY_UNINITIALIZED == t->estate)
3241 GCT_change_estate (t, CADET_TUNNEL_KEY_SENT);
3246 * Is the tunnel directed towards the local peer?
3250 * @return #GNUNET_YES if it is loopback.
3253 GCT_is_loopback (const struct CadetTunnel *t)
3255 return (myid == GCP_get_short_id (t->peer));
3260 * Is the tunnel this path already?
3265 * @return #GNUNET_YES a connection uses this path.
3268 GCT_is_path_used (const struct CadetTunnel *t, const struct CadetPeerPath *p)
3270 struct CadetTConnection *iter;
3272 for (iter = t->connection_head; NULL != iter; iter = iter->next)
3273 if (path_equivalent (GCC_get_path (iter->c), p))
3281 * Get a cost of a path for a tunnel considering existing connections.
3284 * @param path Candidate path.
3286 * @return Cost of the path (path length + number of overlapping nodes)
3289 GCT_get_path_cost (const struct CadetTunnel *t,
3290 const struct CadetPeerPath *path)
3292 struct CadetTConnection *iter;
3293 const struct CadetPeerPath *aux;
3294 unsigned int overlap;
3302 GNUNET_assert (NULL != t);
3304 for (i = 0; i < path->length; i++)
3306 for (iter = t->connection_head; NULL != iter; iter = iter->next)
3308 aux = GCC_get_path (iter->c);
3312 for (j = 0; j < aux->length; j++)
3314 if (path->peers[i] == aux->peers[j])
3322 return path->length + overlap;
3327 * Get the static string for the peer this tunnel is directed.
3331 * @return Static string the destination peer's ID.
3334 GCT_2s (const struct CadetTunnel *t)
3339 return GCP_2s (t->peer);
3343 /******************************************************************************/
3344 /***************************** INFO/DEBUG *******************************/
3345 /******************************************************************************/
3348 ax_debug (const struct CadetTunnelAxolotl *ax, enum GNUNET_ErrorType level)
3350 struct GNUNET_CRYPTO_EcdhePublicKey pub;
3351 struct CadetTunnelSkippedKey *iter;
3353 LOG2 (level, "TTT RK \t %s\n",
3354 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &ax->RK));
3356 LOG2 (level, "TTT HKs \t %s\n",
3357 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &ax->HKs));
3358 LOG2 (level, "TTT HKr \t %s\n",
3359 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &ax->HKr));
3360 LOG2 (level, "TTT NHKs\t %s\n",
3361 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &ax->NHKs));
3362 LOG2 (level, "TTT NHKr\t %s\n",
3363 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &ax->NHKr));
3365 LOG2 (level, "TTT CKs \t %s\n",
3366 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &ax->CKs));
3367 LOG2 (level, "TTT CKr \t %s\n",
3368 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &ax->CKr));
3370 GNUNET_CRYPTO_ecdhe_key_get_public (ax->DHRs, &pub);
3371 LOG2 (level, "TTT DHRs\t %s\n",
3372 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &pub));
3373 LOG2 (level, "TTT DHRr\t %s\n",
3374 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &ax->DHRr));
3376 LOG2 (level, "TTT Nr\t %u\tNs\t%u\n", ax->Nr, ax->Ns);
3377 LOG2 (level, "TTT PNs\t %u\tSkipped\t%u\n", ax->PNs, ax->skipped);
3378 LOG2 (level, "TTT Ratchet\t%u\n", ax->ratchet_flag);
3380 for (iter = ax->skipped_head; NULL != iter; iter = iter->next)
3382 LOG2 (level, "TTT HK\t %s\n",
3383 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &iter->HK));
3384 LOG2 (level, "TTT MK\t %s\n",
3385 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &iter->MK));
3390 * Log all possible info about the tunnel state.
3392 * @param t Tunnel to debug.
3393 * @param level Debug level to use.
3396 GCT_debug (const struct CadetTunnel *t, enum GNUNET_ErrorType level)
3398 struct CadetTChannel *iter_ch;
3399 struct CadetTConnection *iter_c;
3402 do_log = GNUNET_get_log_call_status (level & (~GNUNET_ERROR_TYPE_BULK),
3404 __FILE__, __FUNCTION__, __LINE__);
3408 LOG2 (level, "TTT DEBUG TUNNEL TOWARDS %s\n", GCT_2s (t));
3409 LOG2 (level, "TTT cstate %s, estate %s\n",
3410 cstate2s (t->cstate), estate2s (t->estate));
3411 #if DUMP_KEYS_TO_STDERR
3412 ax_debug (t->ax, level);
3414 LOG2 (level, "TTT tq_head %p, tq_tail %p\n", t->tq_head, t->tq_tail);
3415 LOG2 (level, "TTT destroy %p\n", t->destroy_task);
3416 LOG2 (level, "TTT channels:\n");
3417 for (iter_ch = t->channel_head; NULL != iter_ch; iter_ch = iter_ch->next)
3419 GCCH_debug (iter_ch->ch, level);
3422 LOG2 (level, "TTT connections:\n");
3423 for (iter_c = t->connection_head; NULL != iter_c; iter_c = iter_c->next)
3425 GCC_debug (iter_c->c, level);
3428 LOG2 (level, "TTT DEBUG TUNNEL END\n");
3433 * Iterate all tunnels.
3435 * @param iter Iterator.
3436 * @param cls Closure for @c iter.
3439 GCT_iterate_all (GNUNET_CONTAINER_PeerMapIterator iter, void *cls)
3441 GNUNET_CONTAINER_multipeermap_iterate (tunnels, iter, cls);
3446 * Count all tunnels.
3448 * @return Number of tunnels to remote peers kept by this peer.
3451 GCT_count_all (void)
3453 return GNUNET_CONTAINER_multipeermap_size (tunnels);
3458 * Iterate all connections of a tunnel.
3460 * @param t Tunnel whose connections to iterate.
3461 * @param iter Iterator.
3462 * @param cls Closure for @c iter.
3465 GCT_iterate_connections (struct CadetTunnel *t, GCT_conn_iter iter, void *cls)
3467 struct CadetTConnection *ct;
3469 for (ct = t->connection_head; NULL != ct; ct = ct->next)
3475 * Iterate all channels of a tunnel.
3477 * @param t Tunnel whose channels to iterate.
3478 * @param iter Iterator.
3479 * @param cls Closure for @c iter.
3482 GCT_iterate_channels (struct CadetTunnel *t, GCT_chan_iter iter, void *cls)
3484 struct CadetTChannel *cht;
3486 for (cht = t->channel_head; NULL != cht; cht = cht->next)
3487 iter (cls, cht->ch);