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22 * @file core/gnunet-service-core_kx.c
23 * @brief code for managing the key exchange (SET_KEY, PING, PONG) with other peers
24 * @author Christian Grothoff
27 #include "gnunet-service-core_kx.h"
28 #include "gnunet-service-core.h"
29 #include "gnunet-service-core_clients.h"
30 #include "gnunet-service-core_neighbours.h"
31 #include "gnunet-service-core_sessions.h"
32 #include "gnunet_statistics_service.h"
33 #include "gnunet_constants.h"
34 #include "gnunet_signatures.h"
35 #include "gnunet_protocols.h"
40 * How long do we wait for SET_KEY confirmation initially?
42 #define INITIAL_SET_KEY_RETRY_FREQUENCY GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS, 10)
45 * What is the minimum frequency for a PING message?
47 #define MIN_PING_FREQUENCY GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS, 5)
50 * How often do we rekey?
52 #define REKEY_FREQUENCY GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_HOURS, 12)
55 * What time difference do we tolerate?
57 #define REKEY_TOLERANCE GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MINUTES, 5)
60 * What is the maximum age of a message for us to consider processing
61 * it? Note that this looks at the timestamp used by the other peer,
62 * so clock skew between machines does come into play here. So this
63 * should be picked high enough so that a little bit of clock skew
64 * does not prevent peers from connecting to us.
66 #define MAX_MESSAGE_AGE GNUNET_TIME_UNIT_DAYS
70 GNUNET_NETWORK_STRUCT_BEGIN
73 * Message transmitted with the signed ephemeral key of a peer. The
74 * session key is then derived from the two ephemeral keys (ECDHE).
76 struct EphemeralKeyMessage
80 * Message type is #GNUNET_MESSAGE_TYPE_CORE_EPHEMERAL_KEY.
82 struct GNUNET_MessageHeader header;
85 * Status of the sender (should be in `enum PeerStateMachine`), nbo.
87 int32_t sender_status GNUNET_PACKED;
90 * An ECC signature of the @e origin_identity asserting the validity of
91 * the given ephemeral key.
93 struct GNUNET_CRYPTO_EddsaSignature signature;
96 * Information about what is being signed.
98 struct GNUNET_CRYPTO_EccSignaturePurpose purpose;
101 * At what time was this key created (beginning of validity).
103 struct GNUNET_TIME_AbsoluteNBO creation_time;
106 * When does the given ephemeral key expire (end of validity).
108 struct GNUNET_TIME_AbsoluteNBO expiration_time;
111 * Ephemeral public ECC key.
113 struct GNUNET_CRYPTO_EcdhePublicKey ephemeral_key;
116 * Public key of the signing peer (persistent version, not the ephemeral public key).
118 struct GNUNET_PeerIdentity origin_identity;
124 * We're sending an (encrypted) PING to the other peer to check if he
125 * can decrypt. The other peer should respond with a PONG with the
126 * same content, except this time encrypted with the receiver's key.
131 * Message type is #GNUNET_MESSAGE_TYPE_CORE_PING.
133 struct GNUNET_MessageHeader header;
138 uint32_t iv_seed GNUNET_PACKED;
141 * Intended target of the PING, used primarily to check
142 * that decryption actually worked.
144 struct GNUNET_PeerIdentity target;
147 * Random number chosen to make replay harder.
149 uint32_t challenge GNUNET_PACKED;
154 * Response to a PING. Includes data from the original PING.
159 * Message type is #GNUNET_MESSAGE_TYPE_CORE_PONG.
161 struct GNUNET_MessageHeader header;
166 uint32_t iv_seed GNUNET_PACKED;
169 * Random number to make replay attacks harder.
171 uint32_t challenge GNUNET_PACKED;
174 * Reserved, always zero.
179 * Intended target of the PING, used primarily to check
180 * that decryption actually worked.
182 struct GNUNET_PeerIdentity target;
187 * Encapsulation for encrypted messages exchanged between
188 * peers. Followed by the actual encrypted data.
190 struct EncryptedMessage
193 * Message type is #GNUNET_MESSAGE_TYPE_CORE_ENCRYPTED_MESSAGE.
195 struct GNUNET_MessageHeader header;
198 * Random value used for IV generation.
200 uint32_t iv_seed GNUNET_PACKED;
203 * MAC of the encrypted message (starting at @e sequence_number),
204 * used to verify message integrity. Everything after this value
205 * (excluding this value itself) will be encrypted and authenticated.
206 * #ENCRYPTED_HEADER_SIZE must be set to the offset of the *next* field.
208 struct GNUNET_HashCode hmac;
211 * Sequence number, in network byte order. This field
212 * must be the first encrypted/decrypted field
214 uint32_t sequence_number GNUNET_PACKED;
217 * Reserved, always zero.
222 * Timestamp. Used to prevent replay of ancient messages
223 * (recent messages are caught with the sequence number).
225 struct GNUNET_TIME_AbsoluteNBO timestamp;
228 GNUNET_NETWORK_STRUCT_END
232 * Number of bytes (at the beginning) of `struct EncryptedMessage`
233 * that are NOT encrypted.
235 #define ENCRYPTED_HEADER_SIZE (offsetof(struct EncryptedMessage, sequence_number))
239 * Information about the status of a key exchange with another peer.
241 struct GSC_KeyExchangeInfo
247 struct GSC_KeyExchangeInfo *next;
252 struct GSC_KeyExchangeInfo *prev;
255 * Identity of the peer.
257 struct GNUNET_PeerIdentity peer;
260 * PING message we transmit to the other peer.
262 struct PingMessage ping;
265 * Ephemeral public ECC key of the other peer.
267 struct GNUNET_CRYPTO_EcdhePublicKey other_ephemeral_key;
270 * Key we use to encrypt our messages for the other peer
271 * (initialized by us when we do the handshake).
273 struct GNUNET_CRYPTO_SymmetricSessionKey encrypt_key;
276 * Key we use to decrypt messages from the other peer
277 * (given to us by the other peer during the handshake).
279 struct GNUNET_CRYPTO_SymmetricSessionKey decrypt_key;
282 * At what time did the other peer generate the decryption key?
284 struct GNUNET_TIME_Absolute foreign_key_expires;
287 * When should the session time out (if there are no PONGs)?
289 struct GNUNET_TIME_Absolute timeout;
292 * What was the last timeout we informed our monitors about?
294 struct GNUNET_TIME_Absolute last_notify_timeout;
297 * At what frequency are we currently re-trying SET_KEY messages?
299 struct GNUNET_TIME_Relative set_key_retry_frequency;
302 * ID of task used for re-trying SET_KEY and PING message.
304 struct GNUNET_SCHEDULER_Task *retry_set_key_task;
307 * ID of task used for sending keep-alive pings.
309 struct GNUNET_SCHEDULER_Task *keep_alive_task;
312 * Bit map indicating which of the 32 sequence numbers before the last
313 * were received (good for accepting out-of-order packets and
314 * estimating reliability of the connection)
316 unsigned int last_packets_bitmap;
319 * last sequence number received on this connection (highest)
321 uint32_t last_sequence_number_received;
324 * last sequence number transmitted
326 uint32_t last_sequence_number_sent;
329 * What was our PING challenge number (for this peer)?
331 uint32_t ping_challenge;
334 * What is our connection status?
336 enum GNUNET_CORE_KxState status;
344 static struct GNUNET_CRYPTO_EddsaPrivateKey *my_private_key;
347 * Our ephemeral private key.
349 static struct GNUNET_CRYPTO_EcdhePrivateKey *my_ephemeral_key;
352 * Current message we send for a key exchange.
354 static struct EphemeralKeyMessage current_ekm;
357 * Our message stream tokenizer (for encrypted payload).
359 static struct GNUNET_SERVER_MessageStreamTokenizer *mst;
364 static struct GSC_KeyExchangeInfo *kx_head;
369 static struct GSC_KeyExchangeInfo *kx_tail;
372 * Task scheduled for periodic re-generation (and thus rekeying) of our
375 static struct GNUNET_SCHEDULER_Task *rekey_task;
378 * Notification context for all monitors.
380 static struct GNUNET_SERVER_NotificationContext *nc;
384 * Inform the given monitor about the KX state of
387 * @param client client to inform
388 * @param kx key exchange state to inform about
391 monitor_notify (struct GNUNET_SERVER_Client *client,
392 struct GSC_KeyExchangeInfo *kx)
394 struct MonitorNotifyMessage msg;
396 msg.header.type = htons (GNUNET_MESSAGE_TYPE_CORE_MONITOR_NOTIFY);
397 msg.header.size = htons (sizeof (msg));
398 msg.state = htonl ((uint32_t) kx->status);
400 msg.timeout = GNUNET_TIME_absolute_hton (kx->timeout);
401 GNUNET_SERVER_notification_context_unicast (nc,
409 * Calculate seed value we should use for a message.
411 * @param kx key exchange context
414 calculate_seed (struct GSC_KeyExchangeInfo *kx)
416 /* Note: may want to make this non-random and instead
417 derive from key material to avoid having an undetectable
419 return htonl (GNUNET_CRYPTO_random_u32
420 (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX));
425 * Inform all monitors about the KX state of the given peer.
427 * @param kx key exchange state to inform about
430 monitor_notify_all (struct GSC_KeyExchangeInfo *kx)
432 struct MonitorNotifyMessage msg;
434 msg.header.type = htons (GNUNET_MESSAGE_TYPE_CORE_MONITOR_NOTIFY);
435 msg.header.size = htons (sizeof (msg));
436 msg.state = htonl ((uint32_t) kx->status);
438 msg.timeout = GNUNET_TIME_absolute_hton (kx->timeout);
439 GNUNET_SERVER_notification_context_broadcast (nc,
442 kx->last_notify_timeout = kx->timeout;
447 * Derive an authentication key from "set key" information
449 * @param akey authentication key to derive
450 * @param skey session key to use
451 * @param seed seed to use
454 derive_auth_key (struct GNUNET_CRYPTO_AuthKey *akey,
455 const struct GNUNET_CRYPTO_SymmetricSessionKey *skey,
458 static const char ctx[] = "authentication key";
460 GNUNET_CRYPTO_hmac_derive_key (akey, skey,
461 &seed, sizeof (seed),
462 skey, sizeof (struct GNUNET_CRYPTO_SymmetricSessionKey),
469 * Derive an IV from packet information
471 * @param iv initialization vector to initialize
472 * @param skey session key to use
473 * @param seed seed to use
474 * @param identity identity of the other peer to use
477 derive_iv (struct GNUNET_CRYPTO_SymmetricInitializationVector *iv,
478 const struct GNUNET_CRYPTO_SymmetricSessionKey *skey,
480 const struct GNUNET_PeerIdentity *identity)
482 static const char ctx[] = "initialization vector";
484 GNUNET_CRYPTO_symmetric_derive_iv (iv, skey,
485 &seed, sizeof (seed),
487 sizeof (struct GNUNET_PeerIdentity), ctx,
493 * Derive an IV from pong packet information
495 * @param iv initialization vector to initialize
496 * @param skey session key to use
497 * @param seed seed to use
498 * @param challenge nonce to use
499 * @param identity identity of the other peer to use
502 derive_pong_iv (struct GNUNET_CRYPTO_SymmetricInitializationVector *iv,
503 const struct GNUNET_CRYPTO_SymmetricSessionKey *skey,
506 const struct GNUNET_PeerIdentity *identity)
508 static const char ctx[] = "pong initialization vector";
510 GNUNET_CRYPTO_symmetric_derive_iv (iv, skey,
511 &seed, sizeof (seed),
513 sizeof (struct GNUNET_PeerIdentity),
514 &challenge, sizeof (challenge),
521 * Derive an AES key from key material
523 * @param sender peer identity of the sender
524 * @param receiver peer identity of the sender
525 * @param key_material high entropy key material to use
526 * @param skey set to derived session key
529 derive_aes_key (const struct GNUNET_PeerIdentity *sender,
530 const struct GNUNET_PeerIdentity *receiver,
531 const struct GNUNET_HashCode *key_material,
532 struct GNUNET_CRYPTO_SymmetricSessionKey *skey)
534 static const char ctx[] = "aes key generation vector";
536 GNUNET_CRYPTO_kdf (skey, sizeof (struct GNUNET_CRYPTO_SymmetricSessionKey),
538 key_material, sizeof (struct GNUNET_HashCode),
539 sender, sizeof (struct GNUNET_PeerIdentity),
540 receiver, sizeof (struct GNUNET_PeerIdentity),
546 * Encrypt size bytes from @a in and write the result to @a out. Use the
547 * @a kx key for outbound traffic of the given neighbour.
549 * @param kx key information context
550 * @param iv initialization vector to use
551 * @param in ciphertext
552 * @param out plaintext
553 * @param size size of @a in/@a out
554 * @return #GNUNET_OK on success
557 do_encrypt (struct GSC_KeyExchangeInfo *kx,
558 const struct GNUNET_CRYPTO_SymmetricInitializationVector *iv,
563 if (size != (uint16_t) size)
568 GNUNET_assert (size ==
569 GNUNET_CRYPTO_symmetric_encrypt (in, (uint16_t) size,
570 &kx->encrypt_key, iv, out));
571 GNUNET_STATISTICS_update (GSC_stats, gettext_noop ("# bytes encrypted"), size,
573 /* the following is too sensitive to write to log files by accident,
574 so we require manual intervention to get this one... */
576 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
577 "Encrypted %u bytes for `%s' using key %u, IV %u\n",
579 GNUNET_i2s (&kx->peer),
580 (unsigned int) kx->encrypt_key.crc32, GNUNET_CRYPTO_crc32_n (iv,
589 * Decrypt size bytes from @a in and write the result to @a out. Use the
590 * @a kx key for inbound traffic of the given neighbour. This function does
591 * NOT do any integrity-checks on the result.
593 * @param kx key information context
594 * @param iv initialization vector to use
595 * @param in ciphertext
596 * @param out plaintext
597 * @param size size of @a in / @a out
598 * @return #GNUNET_OK on success
601 do_decrypt (struct GSC_KeyExchangeInfo *kx,
602 const struct GNUNET_CRYPTO_SymmetricInitializationVector *iv,
607 if (size != (uint16_t) size)
612 if ( (kx->status != GNUNET_CORE_KX_STATE_KEY_RECEIVED) &&
613 (kx->status != GNUNET_CORE_KX_STATE_UP) &&
614 (kx->status != GNUNET_CORE_KX_STATE_REKEY_SENT) )
617 return GNUNET_SYSERR;
620 GNUNET_CRYPTO_symmetric_decrypt (in,
627 return GNUNET_SYSERR;
629 GNUNET_STATISTICS_update (GSC_stats,
630 gettext_noop ("# bytes decrypted"),
633 /* the following is too sensitive to write to log files by accident,
634 so we require manual intervention to get this one... */
636 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
637 "Decrypted %u bytes from `%s' using key %u, IV %u\n",
639 GNUNET_i2s (&kx->peer),
640 (unsigned int) kx->decrypt_key.crc32,
641 GNUNET_CRYPTO_crc32_n (iv,
650 * Send our key (and encrypted PING) to the other peer.
652 * @param kx key exchange context
655 send_key (struct GSC_KeyExchangeInfo *kx);
659 * Task that will retry #send_key() if our previous attempt failed.
661 * @param cls our `struct GSC_KeyExchangeInfo`
664 set_key_retry_task (void *cls)
666 struct GSC_KeyExchangeInfo *kx = cls;
668 kx->retry_set_key_task = NULL;
669 kx->set_key_retry_frequency = GNUNET_TIME_STD_BACKOFF (kx->set_key_retry_frequency);
670 GNUNET_assert (GNUNET_CORE_KX_STATE_DOWN != kx->status);
676 * Create a fresh PING message for transmission to the other peer.
678 * @param kx key exchange context to create PING for
681 setup_fresh_ping (struct GSC_KeyExchangeInfo *kx)
683 struct PingMessage pp;
684 struct PingMessage *pm;
685 struct GNUNET_CRYPTO_SymmetricInitializationVector iv;
688 kx->ping_challenge = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK,
690 pm->header.size = htons (sizeof (struct PingMessage));
691 pm->header.type = htons (GNUNET_MESSAGE_TYPE_CORE_PING);
692 pm->iv_seed = calculate_seed (kx);
693 derive_iv (&iv, &kx->encrypt_key, pm->iv_seed, &kx->peer);
694 pp.challenge = kx->ping_challenge;
695 pp.target = kx->peer;
696 do_encrypt (kx, &iv, &pp.target, &pm->target,
697 sizeof (struct PingMessage) - ((void *) &pm->target -
703 * Start the key exchange with the given peer.
705 * @param pid identity of the peer to do a key exchange with
706 * @return key exchange information context
708 struct GSC_KeyExchangeInfo *
709 GSC_KX_start (const struct GNUNET_PeerIdentity *pid)
711 struct GSC_KeyExchangeInfo *kx;
712 struct GNUNET_HashCode h1;
713 struct GNUNET_HashCode h2;
715 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
716 "Initiating key exchange with `%s'\n",
718 GNUNET_STATISTICS_update (GSC_stats,
719 gettext_noop ("# key exchanges initiated"),
722 kx = GNUNET_new (struct GSC_KeyExchangeInfo);
724 kx->set_key_retry_frequency = INITIAL_SET_KEY_RETRY_FREQUENCY;
725 GNUNET_CONTAINER_DLL_insert (kx_head,
728 kx->status = GNUNET_CORE_KX_STATE_KEY_SENT;
729 monitor_notify_all (kx);
730 GNUNET_CRYPTO_hash (pid,
731 sizeof (struct GNUNET_PeerIdentity),
733 GNUNET_CRYPTO_hash (&GSC_my_identity,
734 sizeof (struct GNUNET_PeerIdentity),
736 if (0 < GNUNET_CRYPTO_hash_cmp (&h1,
739 /* peer with "lower" identity starts KX, otherwise we typically end up
740 with both peers starting the exchange and transmit the 'set key'
746 /* peer with "higher" identity starts a delayed KX, if the "lower" peer
747 * does not start a KX since he sees no reasons to do so */
748 kx->retry_set_key_task
749 = GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_SECONDS,
758 * Stop key exchange with the given peer. Clean up key material.
760 * @param kx key exchange to stop
763 GSC_KX_stop (struct GSC_KeyExchangeInfo *kx)
765 GSC_SESSIONS_end (&kx->peer);
766 GNUNET_STATISTICS_update (GSC_stats, gettext_noop ("# key exchanges stopped"),
768 if (NULL != kx->retry_set_key_task)
770 GNUNET_SCHEDULER_cancel (kx->retry_set_key_task);
771 kx->retry_set_key_task = NULL;
773 if (NULL != kx->keep_alive_task)
775 GNUNET_SCHEDULER_cancel (kx->keep_alive_task);
776 kx->keep_alive_task = NULL;
778 kx->status = GNUNET_CORE_KX_PEER_DISCONNECT;
779 monitor_notify_all (kx);
780 GNUNET_CONTAINER_DLL_remove (kx_head,
788 * Send our PING to the other peer.
790 * @param kx key exchange context
793 send_ping (struct GSC_KeyExchangeInfo *kx)
795 GNUNET_STATISTICS_update (GSC_stats,
796 gettext_noop ("# PING messages transmitted"),
799 GSC_NEIGHBOURS_transmit (&kx->peer,
801 kx->set_key_retry_frequency);
806 * Derive fresh session keys from the current ephemeral keys.
808 * @param kx session to derive keys for
811 derive_session_keys (struct GSC_KeyExchangeInfo *kx)
813 struct GNUNET_HashCode key_material;
816 GNUNET_CRYPTO_ecc_ecdh (my_ephemeral_key,
817 &kx->other_ephemeral_key,
823 derive_aes_key (&GSC_my_identity,
827 derive_aes_key (&kx->peer,
831 memset (&key_material, 0, sizeof (key_material));
832 /* fresh key, reset sequence numbers */
833 kx->last_sequence_number_received = 0;
834 kx->last_packets_bitmap = 0;
835 setup_fresh_ping (kx);
840 * We received a #GNUNET_MESSAGE_TYPE_CORE_EPHEMERAL_KEY message.
841 * Validate and update our key material and status.
843 * @param kx key exchange status for the corresponding peer
844 * @param msg the set key message we received
847 GSC_KX_handle_ephemeral_key (struct GSC_KeyExchangeInfo *kx,
848 const struct GNUNET_MessageHeader *msg)
850 const struct EphemeralKeyMessage *m;
851 struct GNUNET_TIME_Absolute start_t;
852 struct GNUNET_TIME_Absolute end_t;
853 struct GNUNET_TIME_Absolute now;
854 enum GNUNET_CORE_KxState sender_status;
857 size = ntohs (msg->size);
858 if (sizeof (struct EphemeralKeyMessage) != size)
863 m = (const struct EphemeralKeyMessage *) msg;
864 end_t = GNUNET_TIME_absolute_ntoh (m->expiration_time);
865 if ( ( (GNUNET_CORE_KX_STATE_KEY_RECEIVED == kx->status) ||
866 (GNUNET_CORE_KX_STATE_UP == kx->status) ||
867 (GNUNET_CORE_KX_STATE_REKEY_SENT == kx->status) ) &&
868 (end_t.abs_value_us < kx->foreign_key_expires.abs_value_us) )
870 GNUNET_STATISTICS_update (GSC_stats,
871 gettext_noop ("# old ephemeral keys ignored"),
875 start_t = GNUNET_TIME_absolute_ntoh (m->creation_time);
877 GNUNET_STATISTICS_update (GSC_stats,
878 gettext_noop ("# ephemeral keys received"),
882 memcmp (&m->origin_identity,
884 sizeof (struct GNUNET_PeerIdentity)))
886 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
887 "Received EPHEMERAL_KEY from %s, but expected %s\n",
888 GNUNET_i2s (&m->origin_identity),
889 GNUNET_i2s_full (&kx->peer));
893 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
894 "Core service receives EPHEMERAL_KEY request from `%s'.\n",
895 GNUNET_i2s (&kx->peer));
896 if ((ntohl (m->purpose.size) !=
897 sizeof (struct GNUNET_CRYPTO_EccSignaturePurpose) +
898 sizeof (struct GNUNET_TIME_AbsoluteNBO) +
899 sizeof (struct GNUNET_TIME_AbsoluteNBO) +
900 sizeof (struct GNUNET_CRYPTO_EddsaPublicKey) +
901 sizeof (struct GNUNET_CRYPTO_EddsaPublicKey)) ||
903 GNUNET_CRYPTO_eddsa_verify (GNUNET_SIGNATURE_PURPOSE_SET_ECC_KEY,
906 &m->origin_identity.public_key)))
908 /* invalid signature */
912 now = GNUNET_TIME_absolute_get ();
913 if ( (end_t.abs_value_us < GNUNET_TIME_absolute_subtract (now, REKEY_TOLERANCE).abs_value_us) ||
914 (start_t.abs_value_us > GNUNET_TIME_absolute_add (now, REKEY_TOLERANCE).abs_value_us) )
916 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
917 _("Ephemeral key message from peer `%s' rejected as its validity range does not match our system time (%llu not in [%llu,%llu]).\n"),
918 GNUNET_i2s (&kx->peer),
919 (unsigned long long) now.abs_value_us,
920 (unsigned long long) start_t.abs_value_us,
921 (unsigned long long) end_t.abs_value_us);
924 kx->other_ephemeral_key = m->ephemeral_key;
925 kx->foreign_key_expires = end_t;
926 derive_session_keys (kx);
927 GNUNET_STATISTICS_update (GSC_stats,
928 gettext_noop ("# EPHEMERAL_KEY messages received"), 1,
931 /* check if we still need to send the sender our key */
932 sender_status = (enum GNUNET_CORE_KxState) ntohl (m->sender_status);
933 switch (sender_status)
935 case GNUNET_CORE_KX_STATE_DOWN:
938 case GNUNET_CORE_KX_STATE_KEY_SENT:
939 /* fine, need to send our key after updating our status, see below */
940 GSC_SESSIONS_reinit (&kx->peer);
942 case GNUNET_CORE_KX_STATE_KEY_RECEIVED:
943 /* other peer already got our key, but typemap did go down */
944 GSC_SESSIONS_reinit (&kx->peer);
946 case GNUNET_CORE_KX_STATE_UP:
947 /* other peer already got our key, typemap NOT down */
949 case GNUNET_CORE_KX_STATE_REKEY_SENT:
950 /* other peer already got our key, typemap NOT down */
956 /* check if we need to confirm everything is fine via PING + PONG */
959 case GNUNET_CORE_KX_STATE_DOWN:
960 GNUNET_assert (NULL == kx->keep_alive_task);
961 kx->status = GNUNET_CORE_KX_STATE_KEY_RECEIVED;
962 monitor_notify_all (kx);
963 if (GNUNET_CORE_KX_STATE_KEY_SENT == sender_status)
968 case GNUNET_CORE_KX_STATE_KEY_SENT:
969 GNUNET_assert (NULL == kx->keep_alive_task);
970 kx->status = GNUNET_CORE_KX_STATE_KEY_RECEIVED;
971 monitor_notify_all (kx);
972 if (GNUNET_CORE_KX_STATE_KEY_SENT == sender_status)
977 case GNUNET_CORE_KX_STATE_KEY_RECEIVED:
978 GNUNET_assert (NULL == kx->keep_alive_task);
979 if (GNUNET_CORE_KX_STATE_KEY_SENT == sender_status)
984 case GNUNET_CORE_KX_STATE_UP:
985 kx->status = GNUNET_CORE_KX_STATE_REKEY_SENT;
986 monitor_notify_all (kx);
987 if (GNUNET_CORE_KX_STATE_KEY_SENT == sender_status)
992 case GNUNET_CORE_KX_STATE_REKEY_SENT:
993 if (GNUNET_CORE_KX_STATE_KEY_SENT == sender_status)
1006 * We received a PING message. Validate and transmit
1009 * @param kx key exchange status for the corresponding peer
1010 * @param msg the encrypted PING message itself
1013 GSC_KX_handle_ping (struct GSC_KeyExchangeInfo *kx,
1014 const struct GNUNET_MessageHeader *msg)
1016 const struct PingMessage *m;
1017 struct PingMessage t;
1018 struct PongMessage tx;
1019 struct PongMessage tp;
1020 struct GNUNET_CRYPTO_SymmetricInitializationVector iv;
1023 msize = ntohs (msg->size);
1024 if (msize != sizeof (struct PingMessage))
1026 GNUNET_break_op (0);
1029 GNUNET_STATISTICS_update (GSC_stats,
1030 gettext_noop ("# PING messages received"),
1033 if ( (kx->status != GNUNET_CORE_KX_STATE_KEY_RECEIVED) &&
1034 (kx->status != GNUNET_CORE_KX_STATE_UP) &&
1035 (kx->status != GNUNET_CORE_KX_STATE_REKEY_SENT))
1038 GNUNET_STATISTICS_update (GSC_stats,
1039 gettext_noop ("# PING messages dropped (out of order)"),
1044 m = (const struct PingMessage *) msg;
1045 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1046 "Core service receives PING request from `%s'.\n",
1047 GNUNET_i2s (&kx->peer));
1048 derive_iv (&iv, &kx->decrypt_key, m->iv_seed, &GSC_my_identity);
1050 do_decrypt (kx, &iv, &m->target, &t.target,
1051 sizeof (struct PingMessage) - ((void *) &m->target -
1054 GNUNET_break_op (0);
1060 sizeof (struct GNUNET_PeerIdentity)))
1062 if (GNUNET_CORE_KX_STATE_REKEY_SENT != kx->status)
1063 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
1064 "Decryption of PING from peer `%s' failed\n",
1065 GNUNET_i2s (&kx->peer));
1067 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1068 "Decryption of PING from peer `%s' failed after rekey (harmless)\n",
1069 GNUNET_i2s (&kx->peer));
1070 GNUNET_break_op (0);
1073 /* construct PONG */
1075 tx.challenge = t.challenge;
1076 tx.target = t.target;
1077 tp.header.type = htons (GNUNET_MESSAGE_TYPE_CORE_PONG);
1078 tp.header.size = htons (sizeof (struct PongMessage));
1079 tp.iv_seed = calculate_seed (kx);
1080 derive_pong_iv (&iv,
1089 sizeof (struct PongMessage) - ((void *) &tp.challenge -
1091 GNUNET_STATISTICS_update (GSC_stats,
1092 gettext_noop ("# PONG messages created"),
1095 GSC_NEIGHBOURS_transmit (&kx->peer,
1097 kx->set_key_retry_frequency);
1102 * Task triggered when a neighbour entry is about to time out
1103 * (and we should prevent this by sending a PING).
1105 * @param cls the `struct GSC_KeyExchangeInfo`
1108 send_keep_alive (void *cls)
1110 struct GSC_KeyExchangeInfo *kx = cls;
1111 struct GNUNET_TIME_Relative retry;
1112 struct GNUNET_TIME_Relative left;
1114 kx->keep_alive_task = NULL;
1115 left = GNUNET_TIME_absolute_get_remaining (kx->timeout);
1116 if (0 == left.rel_value_us)
1118 GNUNET_STATISTICS_update (GSC_stats,
1119 gettext_noop ("# sessions terminated by timeout"),
1122 GSC_SESSIONS_end (&kx->peer);
1123 kx->status = GNUNET_CORE_KX_STATE_KEY_SENT;
1124 monitor_notify_all (kx);
1128 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1129 "Sending KEEPALIVE to `%s'\n",
1130 GNUNET_i2s (&kx->peer));
1131 GNUNET_STATISTICS_update (GSC_stats,
1132 gettext_noop ("# keepalive messages sent"),
1135 setup_fresh_ping (kx);
1138 GNUNET_TIME_relative_max (GNUNET_TIME_relative_divide (left, 2),
1139 MIN_PING_FREQUENCY);
1140 kx->keep_alive_task =
1141 GNUNET_SCHEDULER_add_delayed (retry,
1148 * We've seen a valid message from the other peer.
1149 * Update the time when the session would time out
1150 * and delay sending our keep alive message further.
1152 * @param kx key exchange where we saw activity
1155 update_timeout (struct GSC_KeyExchangeInfo *kx)
1157 struct GNUNET_TIME_Relative delta;
1160 GNUNET_TIME_relative_to_absolute
1161 (GNUNET_CONSTANTS_IDLE_CONNECTION_TIMEOUT);
1162 delta = GNUNET_TIME_absolute_get_difference (kx->last_notify_timeout,
1164 if (delta.rel_value_us > 5LL * 1000LL * 1000LL)
1166 /* we only notify monitors about timeout changes if those
1167 are bigger than the threshold (5s) */
1168 monitor_notify_all (kx);
1170 if (NULL != kx->keep_alive_task)
1171 GNUNET_SCHEDULER_cancel (kx->keep_alive_task);
1172 kx->keep_alive_task =
1173 GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_relative_divide
1174 (GNUNET_CONSTANTS_IDLE_CONNECTION_TIMEOUT,
1182 * We received a PONG message. Validate and update our status.
1184 * @param kx key exchange context for the the PONG
1185 * @param msg the encrypted PONG message itself
1188 GSC_KX_handle_pong (struct GSC_KeyExchangeInfo *kx,
1189 const struct GNUNET_MessageHeader *msg)
1191 const struct PongMessage *m;
1192 struct PongMessage t;
1193 struct GNUNET_CRYPTO_SymmetricInitializationVector iv;
1196 msize = ntohs (msg->size);
1197 if (sizeof (struct PongMessage) != msize)
1199 GNUNET_break_op (0);
1202 GNUNET_STATISTICS_update (GSC_stats,
1203 gettext_noop ("# PONG messages received"),
1208 case GNUNET_CORE_KX_STATE_DOWN:
1209 GNUNET_STATISTICS_update (GSC_stats,
1210 gettext_noop ("# PONG messages dropped (connection down)"), 1,
1213 case GNUNET_CORE_KX_STATE_KEY_SENT:
1214 GNUNET_STATISTICS_update (GSC_stats,
1215 gettext_noop ("# PONG messages dropped (out of order)"), 1,
1218 case GNUNET_CORE_KX_STATE_KEY_RECEIVED:
1220 case GNUNET_CORE_KX_STATE_UP:
1222 case GNUNET_CORE_KX_STATE_REKEY_SENT:
1228 m = (const struct PongMessage *) msg;
1229 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1230 "Core service receives PONG response from `%s'.\n",
1231 GNUNET_i2s (&kx->peer));
1232 /* mark as garbage, just to be sure */
1233 memset (&t, 255, sizeof (t));
1234 derive_pong_iv (&iv,
1244 sizeof (struct PongMessage) - ((void *) &m->challenge -
1247 GNUNET_break_op (0);
1250 GNUNET_STATISTICS_update (GSC_stats,
1251 gettext_noop ("# PONG messages decrypted"),
1254 if ((0 != memcmp (&t.target,
1256 sizeof (struct GNUNET_PeerIdentity))) ||
1257 (kx->ping_challenge != t.challenge))
1259 /* PONG malformed */
1260 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1261 "Received malformed PONG wanted sender `%s' with challenge %u\n",
1262 GNUNET_i2s (&kx->peer),
1263 (unsigned int) kx->ping_challenge);
1264 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1265 "Received malformed PONG received from `%s' with challenge %u\n",
1266 GNUNET_i2s (&t.target),
1267 (unsigned int) t.challenge);
1270 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1271 "Received PONG from `%s'\n",
1272 GNUNET_i2s (&kx->peer));
1273 /* no need to resend key any longer */
1274 if (NULL != kx->retry_set_key_task)
1276 GNUNET_SCHEDULER_cancel (kx->retry_set_key_task);
1277 kx->retry_set_key_task = NULL;
1281 case GNUNET_CORE_KX_STATE_DOWN:
1282 GNUNET_assert (0); /* should be impossible */
1284 case GNUNET_CORE_KX_STATE_KEY_SENT:
1285 GNUNET_assert (0); /* should be impossible */
1287 case GNUNET_CORE_KX_STATE_KEY_RECEIVED:
1288 GNUNET_STATISTICS_update (GSC_stats,
1289 gettext_noop ("# session keys confirmed via PONG"),
1292 kx->status = GNUNET_CORE_KX_STATE_UP;
1293 monitor_notify_all (kx);
1294 GSC_SESSIONS_create (&kx->peer, kx);
1295 GNUNET_assert (NULL == kx->keep_alive_task);
1296 update_timeout (kx);
1298 case GNUNET_CORE_KX_STATE_UP:
1299 GNUNET_STATISTICS_update (GSC_stats,
1300 gettext_noop ("# timeouts prevented via PONG"),
1303 update_timeout (kx);
1305 case GNUNET_CORE_KX_STATE_REKEY_SENT:
1306 GNUNET_STATISTICS_update (GSC_stats,
1307 gettext_noop ("# rekey operations confirmed via PONG"),
1310 kx->status = GNUNET_CORE_KX_STATE_UP;
1311 monitor_notify_all (kx);
1312 update_timeout (kx);
1322 * Send our key to the other peer.
1324 * @param kx key exchange context
1327 send_key (struct GSC_KeyExchangeInfo *kx)
1329 GNUNET_assert (GNUNET_CORE_KX_STATE_DOWN != kx->status);
1330 if (NULL != kx->retry_set_key_task)
1332 GNUNET_SCHEDULER_cancel (kx->retry_set_key_task);
1333 kx->retry_set_key_task = NULL;
1335 /* always update sender status in SET KEY message */
1336 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1337 "Sending key to `%s' (my status: %d)\n",
1338 GNUNET_i2s (&kx->peer),
1340 current_ekm.sender_status = htonl ((int32_t) (kx->status));
1341 GSC_NEIGHBOURS_transmit (&kx->peer,
1342 ¤t_ekm.header,
1343 kx->set_key_retry_frequency);
1344 if (GNUNET_CORE_KX_STATE_KEY_SENT != kx->status)
1346 kx->retry_set_key_task =
1347 GNUNET_SCHEDULER_add_delayed (kx->set_key_retry_frequency,
1348 &set_key_retry_task,
1354 * Encrypt and transmit a message with the given payload.
1356 * @param kx key exchange context
1357 * @param payload payload of the message
1358 * @param payload_size number of bytes in @a payload
1361 GSC_KX_encrypt_and_transmit (struct GSC_KeyExchangeInfo *kx,
1362 const void *payload,
1363 size_t payload_size)
1365 size_t used = payload_size + sizeof (struct EncryptedMessage);
1366 char pbuf[used]; /* plaintext */
1367 char cbuf[used]; /* ciphertext */
1368 struct EncryptedMessage *em; /* encrypted message */
1369 struct EncryptedMessage *ph; /* plaintext header */
1370 struct GNUNET_CRYPTO_SymmetricInitializationVector iv;
1371 struct GNUNET_CRYPTO_AuthKey auth_key;
1373 ph = (struct EncryptedMessage *) pbuf;
1374 ph->sequence_number = htonl (++kx->last_sequence_number_sent);
1375 ph->iv_seed = calculate_seed (kx);
1377 ph->timestamp = GNUNET_TIME_absolute_hton (GNUNET_TIME_absolute_get ());
1378 GNUNET_memcpy (&ph[1],
1382 em = (struct EncryptedMessage *) cbuf;
1383 em->header.size = htons (used);
1384 em->header.type = htons (GNUNET_MESSAGE_TYPE_CORE_ENCRYPTED_MESSAGE);
1385 em->iv_seed = ph->iv_seed;
1390 GNUNET_assert (GNUNET_OK ==
1393 &ph->sequence_number,
1394 &em->sequence_number,
1395 used - ENCRYPTED_HEADER_SIZE));
1396 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1397 "Encrypted %u bytes for %s\n",
1398 (unsigned int) (used - ENCRYPTED_HEADER_SIZE),
1399 GNUNET_i2s (&kx->peer));
1400 derive_auth_key (&auth_key,
1403 GNUNET_CRYPTO_hmac (&auth_key,
1404 &em->sequence_number,
1405 used - ENCRYPTED_HEADER_SIZE,
1407 GSC_NEIGHBOURS_transmit (&kx->peer,
1409 GNUNET_TIME_UNIT_FOREVER_REL);
1414 * Closure for #deliver_message()
1416 struct DeliverMessageContext
1420 * Key exchange context.
1422 struct GSC_KeyExchangeInfo *kx;
1425 * Sender of the message.
1427 const struct GNUNET_PeerIdentity *peer;
1432 * We received an encrypted message. Decrypt, validate and
1433 * pass on to the appropriate clients.
1435 * @param kx key exchange context for encrypting the message
1436 * @param msg encrypted message
1439 GSC_KX_handle_encrypted_message (struct GSC_KeyExchangeInfo *kx,
1440 const struct GNUNET_MessageHeader *msg)
1442 const struct EncryptedMessage *m;
1443 struct EncryptedMessage *pt; /* plaintext */
1444 struct GNUNET_HashCode ph;
1446 struct GNUNET_TIME_Absolute t;
1447 struct GNUNET_CRYPTO_SymmetricInitializationVector iv;
1448 struct GNUNET_CRYPTO_AuthKey auth_key;
1449 struct DeliverMessageContext dmc;
1450 uint16_t size = ntohs (msg->size);
1451 char buf[size] GNUNET_ALIGN;
1454 sizeof (struct EncryptedMessage) + sizeof (struct GNUNET_MessageHeader))
1456 GNUNET_break_op (0);
1459 m = (const struct EncryptedMessage *) msg;
1460 if (GNUNET_CORE_KX_STATE_UP != kx->status)
1462 GNUNET_STATISTICS_update (GSC_stats,
1463 gettext_noop ("# DATA message dropped (out of order)"),
1468 if (0 == GNUNET_TIME_absolute_get_remaining (kx->foreign_key_expires).rel_value_us)
1470 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
1471 _("Session to peer `%s' went down due to key expiration (should not happen)\n"),
1472 GNUNET_i2s (&kx->peer));
1473 GNUNET_STATISTICS_update (GSC_stats,
1474 gettext_noop ("# sessions terminated by key expiration"),
1476 GSC_SESSIONS_end (&kx->peer);
1477 if (NULL != kx->keep_alive_task)
1479 GNUNET_SCHEDULER_cancel (kx->keep_alive_task);
1480 kx->keep_alive_task = NULL;
1482 kx->status = GNUNET_CORE_KX_STATE_KEY_SENT;
1483 monitor_notify_all (kx);
1489 derive_auth_key (&auth_key,
1492 GNUNET_CRYPTO_hmac (&auth_key,
1493 &m->sequence_number,
1494 size - ENCRYPTED_HEADER_SIZE,
1496 if (0 != memcmp (&ph,
1498 sizeof (struct GNUNET_HashCode)))
1500 /* checksum failed */
1501 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1502 "Failed checksum validation for a message from `%s'\n",
1503 GNUNET_i2s (&kx->peer));
1514 &m->sequence_number,
1515 &buf[ENCRYPTED_HEADER_SIZE],
1516 size - ENCRYPTED_HEADER_SIZE))
1518 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1519 "Decrypted %u bytes from %s\n",
1520 (unsigned int) (size - ENCRYPTED_HEADER_SIZE),
1521 GNUNET_i2s (&kx->peer));
1522 pt = (struct EncryptedMessage *) buf;
1524 /* validate sequence number */
1525 snum = ntohl (pt->sequence_number);
1526 if (kx->last_sequence_number_received == snum)
1528 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1529 "Received duplicate message, ignoring.\n");
1530 /* duplicate, ignore */
1531 GNUNET_STATISTICS_update (GSC_stats,
1532 gettext_noop ("# bytes dropped (duplicates)"),
1537 if ((kx->last_sequence_number_received > snum) &&
1538 (kx->last_sequence_number_received - snum > 32))
1540 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1541 "Received ancient out of sequence message, ignoring.\n");
1542 /* ancient out of sequence, ignore */
1543 GNUNET_STATISTICS_update (GSC_stats,
1545 ("# bytes dropped (out of sequence)"), size,
1549 if (kx->last_sequence_number_received > snum)
1551 unsigned int rotbit = 1 << (kx->last_sequence_number_received - snum - 1);
1553 if ((kx->last_packets_bitmap & rotbit) != 0)
1555 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1556 "Received duplicate message, ignoring.\n");
1557 GNUNET_STATISTICS_update (GSC_stats,
1558 gettext_noop ("# bytes dropped (duplicates)"),
1560 /* duplicate, ignore */
1563 kx->last_packets_bitmap |= rotbit;
1565 if (kx->last_sequence_number_received < snum)
1567 unsigned int shift = (snum - kx->last_sequence_number_received);
1569 if (shift >= 8 * sizeof (kx->last_packets_bitmap))
1570 kx->last_packets_bitmap = 0;
1572 kx->last_packets_bitmap <<= shift;
1573 kx->last_sequence_number_received = snum;
1576 /* check timestamp */
1577 t = GNUNET_TIME_absolute_ntoh (pt->timestamp);
1578 if (GNUNET_TIME_absolute_get_duration (t).rel_value_us >
1579 MAX_MESSAGE_AGE.rel_value_us)
1581 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1582 "Message received far too old (%s). Content ignored.\n",
1583 GNUNET_STRINGS_relative_time_to_string (GNUNET_TIME_absolute_get_duration (t),
1585 GNUNET_STATISTICS_update (GSC_stats,
1587 ("# bytes dropped (ancient message)"), size,
1592 /* process decrypted message(s) */
1593 update_timeout (kx);
1594 GNUNET_STATISTICS_update (GSC_stats,
1595 gettext_noop ("# bytes of payload decrypted"),
1596 size - sizeof (struct EncryptedMessage),
1599 dmc.peer = &kx->peer;
1601 GNUNET_SERVER_mst_receive (mst, &dmc,
1602 &buf[sizeof (struct EncryptedMessage)],
1603 size - sizeof (struct EncryptedMessage),
1606 GNUNET_break_op (0);
1611 * Deliver P2P message to interested clients.
1612 * Invokes send twice, once for clients that want the full message, and once
1613 * for clients that only want the header
1615 * @param cls always NULL
1616 * @param client who sent us the message (struct GSC_KeyExchangeInfo)
1617 * @param m the message
1620 deliver_message (void *cls,
1622 const struct GNUNET_MessageHeader *m)
1624 struct DeliverMessageContext *dmc = client;
1626 if (GNUNET_CORE_KX_STATE_UP != dmc->kx->status)
1628 GNUNET_STATISTICS_update (GSC_stats,
1629 gettext_noop ("# PAYLOAD dropped (out of order)"),
1634 switch (ntohs (m->type))
1636 case GNUNET_MESSAGE_TYPE_CORE_BINARY_TYPE_MAP:
1637 case GNUNET_MESSAGE_TYPE_CORE_COMPRESSED_TYPE_MAP:
1638 GSC_SESSIONS_set_typemap (dmc->peer, m);
1640 case GNUNET_MESSAGE_TYPE_CORE_CONFIRM_TYPE_MAP:
1641 GSC_SESSIONS_confirm_typemap (dmc->peer, m);
1644 GSC_CLIENTS_deliver_message (dmc->peer, m,
1646 GNUNET_CORE_OPTION_SEND_FULL_INBOUND);
1647 GSC_CLIENTS_deliver_message (dmc->peer, m,
1648 sizeof (struct GNUNET_MessageHeader),
1649 GNUNET_CORE_OPTION_SEND_HDR_INBOUND);
1656 * Setup the message that links the ephemeral key to our persistent
1657 * public key and generate the appropriate signature.
1660 sign_ephemeral_key ()
1662 current_ekm.header.size = htons (sizeof (struct EphemeralKeyMessage));
1663 current_ekm.header.type = htons (GNUNET_MESSAGE_TYPE_CORE_EPHEMERAL_KEY);
1664 current_ekm.sender_status = 0; /* to be set later */
1665 current_ekm.purpose.purpose = htonl (GNUNET_SIGNATURE_PURPOSE_SET_ECC_KEY);
1666 current_ekm.purpose.size = htonl (sizeof (struct GNUNET_CRYPTO_EccSignaturePurpose) +
1667 sizeof (struct GNUNET_TIME_AbsoluteNBO) +
1668 sizeof (struct GNUNET_TIME_AbsoluteNBO) +
1669 sizeof (struct GNUNET_CRYPTO_EcdhePublicKey) +
1670 sizeof (struct GNUNET_PeerIdentity));
1671 current_ekm.creation_time = GNUNET_TIME_absolute_hton (GNUNET_TIME_absolute_get ());
1673 GNUNET_CONFIGURATION_get_value_yesno (GSC_cfg,
1675 "USE_EPHEMERAL_KEYS"))
1677 current_ekm.expiration_time = GNUNET_TIME_absolute_hton (GNUNET_TIME_relative_to_absolute (GNUNET_TIME_relative_add (REKEY_FREQUENCY,
1682 current_ekm.expiration_time = GNUNET_TIME_absolute_hton (GNUNET_TIME_UNIT_FOREVER_ABS);
1684 GNUNET_CRYPTO_ecdhe_key_get_public (my_ephemeral_key,
1685 ¤t_ekm.ephemeral_key);
1686 current_ekm.origin_identity = GSC_my_identity;
1687 GNUNET_assert (GNUNET_OK ==
1688 GNUNET_CRYPTO_eddsa_sign (my_private_key,
1689 ¤t_ekm.purpose,
1690 ¤t_ekm.signature));
1695 * Task run to trigger rekeying.
1697 * @param cls closure, NULL
1700 do_rekey (void *cls)
1702 struct GSC_KeyExchangeInfo *pos;
1704 rekey_task = GNUNET_SCHEDULER_add_delayed (REKEY_FREQUENCY,
1707 if (NULL != my_ephemeral_key)
1708 GNUNET_free (my_ephemeral_key);
1709 GNUNET_log (GNUNET_ERROR_TYPE_INFO,
1711 my_ephemeral_key = GNUNET_CRYPTO_ecdhe_key_create ();
1712 GNUNET_assert (NULL != my_ephemeral_key);
1713 sign_ephemeral_key ();
1714 for (pos = kx_head; NULL != pos; pos = pos->next)
1716 if (GNUNET_CORE_KX_STATE_UP == pos->status)
1718 pos->status = GNUNET_CORE_KX_STATE_REKEY_SENT;
1719 monitor_notify_all (pos);
1720 derive_session_keys (pos);
1722 if (GNUNET_CORE_KX_STATE_DOWN == pos->status)
1724 pos->status = GNUNET_CORE_KX_STATE_KEY_SENT;
1725 monitor_notify_all (pos);
1727 monitor_notify_all (pos);
1734 * Initialize KX subsystem.
1736 * @param pk private key to use for the peer
1737 * @param server the server of the CORE service
1738 * @return #GNUNET_OK on success, #GNUNET_SYSERR on failure
1741 GSC_KX_init (struct GNUNET_CRYPTO_EddsaPrivateKey *pk,
1742 struct GNUNET_SERVER_Handle *server)
1744 nc = GNUNET_SERVER_notification_context_create (server,
1746 my_private_key = pk;
1747 GNUNET_CRYPTO_eddsa_key_get_public (my_private_key,
1748 &GSC_my_identity.public_key);
1749 my_ephemeral_key = GNUNET_CRYPTO_ecdhe_key_create ();
1750 if (NULL == my_ephemeral_key)
1753 GNUNET_free (my_private_key);
1754 my_private_key = NULL;
1755 return GNUNET_SYSERR;
1757 sign_ephemeral_key ();
1758 rekey_task = GNUNET_SCHEDULER_add_delayed (REKEY_FREQUENCY,
1761 mst = GNUNET_SERVER_mst_create (&deliver_message, NULL);
1767 * Shutdown KX subsystem.
1772 if (NULL != rekey_task)
1774 GNUNET_SCHEDULER_cancel (rekey_task);
1777 if (NULL != my_ephemeral_key)
1779 GNUNET_free (my_ephemeral_key);
1780 my_ephemeral_key = NULL;
1782 if (NULL != my_private_key)
1784 GNUNET_free (my_private_key);
1785 my_private_key = NULL;
1789 GNUNET_SERVER_mst_destroy (mst);
1794 GNUNET_SERVER_notification_context_destroy (nc);
1801 * Handle #GNUNET_MESSAGE_TYPE_CORE_MONITOR_PEERS request. For this
1802 * request type, the client does not have to have transmitted an INIT
1803 * request. All current peers are returned, regardless of which
1804 * message types they accept.
1807 * @param client client sending the iteration request
1808 * @param message iteration request message
1811 GSC_KX_handle_client_monitor_peers (void *cls,
1812 struct GNUNET_SERVER_Client *client,
1813 const struct GNUNET_MessageHeader *message)
1815 struct MonitorNotifyMessage done_msg;
1816 struct GSC_KeyExchangeInfo *kx;
1818 GNUNET_SERVER_receive_done (client, GNUNET_OK);
1819 GNUNET_SERVER_notification_context_add (nc,
1821 for (kx = kx_head; NULL != kx; kx = kx->next)
1822 monitor_notify (client, kx);
1823 done_msg.header.size = htons (sizeof (struct MonitorNotifyMessage));
1824 done_msg.header.type = htons (GNUNET_MESSAGE_TYPE_CORE_MONITOR_NOTIFY);
1825 done_msg.state = htonl ((uint32_t) GNUNET_CORE_KX_ITERATION_FINISHED);
1826 memset (&done_msg.peer, 0, sizeof (struct GNUNET_PeerIdentity));
1827 done_msg.timeout = GNUNET_TIME_absolute_hton (GNUNET_TIME_UNIT_FOREVER_ABS);
1828 GNUNET_SERVER_notification_context_unicast (nc,
1835 /* end of gnunet-service-core_kx.c */