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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`
662 * @param tc scheduler context
665 set_key_retry_task (void *cls,
666 const struct GNUNET_SCHEDULER_TaskContext *tc)
668 struct GSC_KeyExchangeInfo *kx = cls;
670 kx->retry_set_key_task = NULL;
671 kx->set_key_retry_frequency = GNUNET_TIME_STD_BACKOFF (kx->set_key_retry_frequency);
672 GNUNET_assert (GNUNET_CORE_KX_STATE_DOWN != kx->status);
678 * Create a fresh PING message for transmission to the other peer.
680 * @param kx key exchange context to create PING for
683 setup_fresh_ping (struct GSC_KeyExchangeInfo *kx)
685 struct PingMessage pp;
686 struct PingMessage *pm;
687 struct GNUNET_CRYPTO_SymmetricInitializationVector iv;
690 kx->ping_challenge = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK,
692 pm->header.size = htons (sizeof (struct PingMessage));
693 pm->header.type = htons (GNUNET_MESSAGE_TYPE_CORE_PING);
694 pm->iv_seed = calculate_seed (kx);
695 derive_iv (&iv, &kx->encrypt_key, pm->iv_seed, &kx->peer);
696 pp.challenge = kx->ping_challenge;
697 pp.target = kx->peer;
698 do_encrypt (kx, &iv, &pp.target, &pm->target,
699 sizeof (struct PingMessage) - ((void *) &pm->target -
705 * Start the key exchange with the given peer.
707 * @param pid identity of the peer to do a key exchange with
708 * @return key exchange information context
710 struct GSC_KeyExchangeInfo *
711 GSC_KX_start (const struct GNUNET_PeerIdentity *pid)
713 struct GSC_KeyExchangeInfo *kx;
714 struct GNUNET_HashCode h1;
715 struct GNUNET_HashCode h2;
717 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
718 "Initiating key exchange with `%s'\n",
720 GNUNET_STATISTICS_update (GSC_stats,
721 gettext_noop ("# key exchanges initiated"),
724 kx = GNUNET_new (struct GSC_KeyExchangeInfo);
726 kx->set_key_retry_frequency = INITIAL_SET_KEY_RETRY_FREQUENCY;
727 GNUNET_CONTAINER_DLL_insert (kx_head,
730 kx->status = GNUNET_CORE_KX_STATE_KEY_SENT;
731 monitor_notify_all (kx);
732 GNUNET_CRYPTO_hash (pid,
733 sizeof (struct GNUNET_PeerIdentity),
735 GNUNET_CRYPTO_hash (&GSC_my_identity,
736 sizeof (struct GNUNET_PeerIdentity),
738 if (0 < GNUNET_CRYPTO_hash_cmp (&h1,
741 /* peer with "lower" identity starts KX, otherwise we typically end up
742 with both peers starting the exchange and transmit the 'set key'
748 /* peer with "higher" identity starts a delayed KX, if the "lower" peer
749 * does not start a KX since he sees no reasons to do so */
750 kx->retry_set_key_task = GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_SECONDS,
759 * Stop key exchange with the given peer. Clean up key material.
761 * @param kx key exchange to stop
764 GSC_KX_stop (struct GSC_KeyExchangeInfo *kx)
766 GSC_SESSIONS_end (&kx->peer);
767 GNUNET_STATISTICS_update (GSC_stats, gettext_noop ("# key exchanges stopped"),
769 if (NULL != kx->retry_set_key_task)
771 GNUNET_SCHEDULER_cancel (kx->retry_set_key_task);
772 kx->retry_set_key_task = NULL;
774 if (NULL != kx->keep_alive_task)
776 GNUNET_SCHEDULER_cancel (kx->keep_alive_task);
777 kx->keep_alive_task = NULL;
779 kx->status = GNUNET_CORE_KX_PEER_DISCONNECT;
780 monitor_notify_all (kx);
781 GNUNET_CONTAINER_DLL_remove (kx_head,
789 * Send our PING to the other peer.
791 * @param kx key exchange context
794 send_ping (struct GSC_KeyExchangeInfo *kx)
796 GNUNET_STATISTICS_update (GSC_stats,
797 gettext_noop ("# PING messages transmitted"),
800 GSC_NEIGHBOURS_transmit (&kx->peer,
802 kx->set_key_retry_frequency);
807 * Derive fresh session keys from the current ephemeral keys.
809 * @param kx session to derive keys for
812 derive_session_keys (struct GSC_KeyExchangeInfo *kx)
814 struct GNUNET_HashCode key_material;
817 GNUNET_CRYPTO_ecc_ecdh (my_ephemeral_key,
818 &kx->other_ephemeral_key,
824 derive_aes_key (&GSC_my_identity,
828 derive_aes_key (&kx->peer,
832 memset (&key_material, 0, sizeof (key_material));
833 /* fresh key, reset sequence numbers */
834 kx->last_sequence_number_received = 0;
835 kx->last_packets_bitmap = 0;
836 setup_fresh_ping (kx);
841 * We received a #GNUNET_MESSAGE_TYPE_CORE_EPHEMERAL_KEY message.
842 * Validate and update our key material and status.
844 * @param kx key exchange status for the corresponding peer
845 * @param msg the set key message we received
848 GSC_KX_handle_ephemeral_key (struct GSC_KeyExchangeInfo *kx,
849 const struct GNUNET_MessageHeader *msg)
851 const struct EphemeralKeyMessage *m;
852 struct GNUNET_TIME_Absolute start_t;
853 struct GNUNET_TIME_Absolute end_t;
854 struct GNUNET_TIME_Absolute now;
855 enum GNUNET_CORE_KxState sender_status;
858 size = ntohs (msg->size);
859 if (sizeof (struct EphemeralKeyMessage) != size)
864 m = (const struct EphemeralKeyMessage *) msg;
865 end_t = GNUNET_TIME_absolute_ntoh (m->expiration_time);
866 if ( ( (GNUNET_CORE_KX_STATE_KEY_RECEIVED == kx->status) ||
867 (GNUNET_CORE_KX_STATE_UP == kx->status) ||
868 (GNUNET_CORE_KX_STATE_REKEY_SENT == kx->status) ) &&
869 (end_t.abs_value_us < kx->foreign_key_expires.abs_value_us) )
871 GNUNET_STATISTICS_update (GSC_stats,
872 gettext_noop ("# old ephemeral keys ignored"),
876 start_t = GNUNET_TIME_absolute_ntoh (m->creation_time);
878 GNUNET_STATISTICS_update (GSC_stats,
879 gettext_noop ("# ephemeral keys received"),
883 memcmp (&m->origin_identity,
885 sizeof (struct GNUNET_PeerIdentity)))
887 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
888 "Received EPHEMERAL_KEY from %s, but expected %s\n",
889 GNUNET_i2s (&m->origin_identity),
890 GNUNET_i2s_full (&kx->peer));
894 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
895 "Core service receives EPHEMERAL_KEY request from `%s'.\n",
896 GNUNET_i2s (&kx->peer));
897 if ((ntohl (m->purpose.size) !=
898 sizeof (struct GNUNET_CRYPTO_EccSignaturePurpose) +
899 sizeof (struct GNUNET_TIME_AbsoluteNBO) +
900 sizeof (struct GNUNET_TIME_AbsoluteNBO) +
901 sizeof (struct GNUNET_CRYPTO_EddsaPublicKey) +
902 sizeof (struct GNUNET_CRYPTO_EddsaPublicKey)) ||
904 GNUNET_CRYPTO_eddsa_verify (GNUNET_SIGNATURE_PURPOSE_SET_ECC_KEY,
907 &m->origin_identity.public_key)))
909 /* invalid signature */
913 now = GNUNET_TIME_absolute_get ();
914 if ( (end_t.abs_value_us < GNUNET_TIME_absolute_subtract (now, REKEY_TOLERANCE).abs_value_us) ||
915 (start_t.abs_value_us > GNUNET_TIME_absolute_add (now, REKEY_TOLERANCE).abs_value_us) )
917 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
918 _("Ephemeral key message from peer `%s' rejected as its validity range does not match our system time (%llu not in [%llu,%llu]).\n"),
919 GNUNET_i2s (&kx->peer),
921 start_t.abs_value_us,
925 kx->other_ephemeral_key = m->ephemeral_key;
926 kx->foreign_key_expires = end_t;
927 derive_session_keys (kx);
928 GNUNET_STATISTICS_update (GSC_stats,
929 gettext_noop ("# EPHEMERAL_KEY messages received"), 1,
932 /* check if we still need to send the sender our key */
933 sender_status = (enum GNUNET_CORE_KxState) ntohl (m->sender_status);
934 switch (sender_status)
936 case GNUNET_CORE_KX_STATE_DOWN:
939 case GNUNET_CORE_KX_STATE_KEY_SENT:
940 /* fine, need to send our key after updating our status, see below */
941 GSC_SESSIONS_reinit (&kx->peer);
943 case GNUNET_CORE_KX_STATE_KEY_RECEIVED:
944 /* other peer already got our key, but typemap did go down */
945 GSC_SESSIONS_reinit (&kx->peer);
947 case GNUNET_CORE_KX_STATE_UP:
948 /* other peer already got our key, typemap NOT down */
950 case GNUNET_CORE_KX_STATE_REKEY_SENT:
951 /* other peer already got our key, typemap NOT down */
957 /* check if we need to confirm everything is fine via PING + PONG */
960 case GNUNET_CORE_KX_STATE_DOWN:
961 GNUNET_assert (NULL == kx->keep_alive_task);
962 kx->status = GNUNET_CORE_KX_STATE_KEY_RECEIVED;
963 monitor_notify_all (kx);
964 if (GNUNET_CORE_KX_STATE_KEY_SENT == sender_status)
969 case GNUNET_CORE_KX_STATE_KEY_SENT:
970 GNUNET_assert (NULL == kx->keep_alive_task);
971 kx->status = GNUNET_CORE_KX_STATE_KEY_RECEIVED;
972 monitor_notify_all (kx);
973 if (GNUNET_CORE_KX_STATE_KEY_SENT == sender_status)
978 case GNUNET_CORE_KX_STATE_KEY_RECEIVED:
979 GNUNET_assert (NULL == kx->keep_alive_task);
980 if (GNUNET_CORE_KX_STATE_KEY_SENT == sender_status)
985 case GNUNET_CORE_KX_STATE_UP:
986 kx->status = GNUNET_CORE_KX_STATE_REKEY_SENT;
987 monitor_notify_all (kx);
988 if (GNUNET_CORE_KX_STATE_KEY_SENT == sender_status)
993 case GNUNET_CORE_KX_STATE_REKEY_SENT:
994 if (GNUNET_CORE_KX_STATE_KEY_SENT == sender_status)
1007 * We received a PING message. Validate and transmit
1010 * @param kx key exchange status for the corresponding peer
1011 * @param msg the encrypted PING message itself
1014 GSC_KX_handle_ping (struct GSC_KeyExchangeInfo *kx,
1015 const struct GNUNET_MessageHeader *msg)
1017 const struct PingMessage *m;
1018 struct PingMessage t;
1019 struct PongMessage tx;
1020 struct PongMessage tp;
1021 struct GNUNET_CRYPTO_SymmetricInitializationVector iv;
1024 msize = ntohs (msg->size);
1025 if (msize != sizeof (struct PingMessage))
1027 GNUNET_break_op (0);
1030 GNUNET_STATISTICS_update (GSC_stats,
1031 gettext_noop ("# PING messages received"),
1034 if ( (kx->status != GNUNET_CORE_KX_STATE_KEY_RECEIVED) &&
1035 (kx->status != GNUNET_CORE_KX_STATE_UP) &&
1036 (kx->status != GNUNET_CORE_KX_STATE_REKEY_SENT))
1039 GNUNET_STATISTICS_update (GSC_stats,
1040 gettext_noop ("# PING messages dropped (out of order)"),
1045 m = (const struct PingMessage *) msg;
1046 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1047 "Core service receives PING request from `%s'.\n",
1048 GNUNET_i2s (&kx->peer));
1049 derive_iv (&iv, &kx->decrypt_key, m->iv_seed, &GSC_my_identity);
1051 do_decrypt (kx, &iv, &m->target, &t.target,
1052 sizeof (struct PingMessage) - ((void *) &m->target -
1055 GNUNET_break_op (0);
1061 sizeof (struct GNUNET_PeerIdentity)))
1063 if (GNUNET_CORE_KX_STATE_REKEY_SENT != kx->status)
1064 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
1065 "Decryption of PING from peer `%s' failed\n",
1066 GNUNET_i2s (&kx->peer));
1068 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1069 "Decryption of PING from peer `%s' failed after rekey (harmless)\n",
1070 GNUNET_i2s (&kx->peer));
1071 GNUNET_break_op (0);
1074 /* construct PONG */
1076 tx.challenge = t.challenge;
1077 tx.target = t.target;
1078 tp.header.type = htons (GNUNET_MESSAGE_TYPE_CORE_PONG);
1079 tp.header.size = htons (sizeof (struct PongMessage));
1080 tp.iv_seed = calculate_seed (kx);
1081 derive_pong_iv (&iv,
1090 sizeof (struct PongMessage) - ((void *) &tp.challenge -
1092 GNUNET_STATISTICS_update (GSC_stats,
1093 gettext_noop ("# PONG messages created"),
1096 GSC_NEIGHBOURS_transmit (&kx->peer,
1098 kx->set_key_retry_frequency);
1103 * Task triggered when a neighbour entry is about to time out
1104 * (and we should prevent this by sending a PING).
1106 * @param cls the `struct GSC_KeyExchangeInfo`
1107 * @param tc scheduler context (not used)
1110 send_keep_alive (void *cls,
1111 const struct GNUNET_SCHEDULER_TaskContext *tc)
1113 struct GSC_KeyExchangeInfo *kx = cls;
1114 struct GNUNET_TIME_Relative retry;
1115 struct GNUNET_TIME_Relative left;
1117 kx->keep_alive_task = NULL;
1118 left = GNUNET_TIME_absolute_get_remaining (kx->timeout);
1119 if (0 == left.rel_value_us)
1121 GNUNET_STATISTICS_update (GSC_stats,
1122 gettext_noop ("# sessions terminated by timeout"),
1125 GSC_SESSIONS_end (&kx->peer);
1126 kx->status = GNUNET_CORE_KX_STATE_KEY_SENT;
1127 monitor_notify_all (kx);
1131 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1132 "Sending KEEPALIVE to `%s'\n",
1133 GNUNET_i2s (&kx->peer));
1134 GNUNET_STATISTICS_update (GSC_stats,
1135 gettext_noop ("# keepalive messages sent"),
1138 setup_fresh_ping (kx);
1141 GNUNET_TIME_relative_max (GNUNET_TIME_relative_divide (left, 2),
1142 MIN_PING_FREQUENCY);
1143 kx->keep_alive_task =
1144 GNUNET_SCHEDULER_add_delayed (retry,
1151 * We've seen a valid message from the other peer.
1152 * Update the time when the session would time out
1153 * and delay sending our keep alive message further.
1155 * @param kx key exchange where we saw activity
1158 update_timeout (struct GSC_KeyExchangeInfo *kx)
1160 struct GNUNET_TIME_Relative delta;
1163 GNUNET_TIME_relative_to_absolute
1164 (GNUNET_CONSTANTS_IDLE_CONNECTION_TIMEOUT);
1165 delta = GNUNET_TIME_absolute_get_difference (kx->last_notify_timeout,
1167 if (delta.rel_value_us > 5LL * 1000LL * 1000LL)
1169 /* we only notify monitors about timeout changes if those
1170 are bigger than the threshold (5s) */
1171 monitor_notify_all (kx);
1173 if (NULL != kx->keep_alive_task)
1174 GNUNET_SCHEDULER_cancel (kx->keep_alive_task);
1175 kx->keep_alive_task =
1176 GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_relative_divide
1177 (GNUNET_CONSTANTS_IDLE_CONNECTION_TIMEOUT,
1185 * We received a PONG message. Validate and update our status.
1187 * @param kx key exchange context for the the PONG
1188 * @param msg the encrypted PONG message itself
1191 GSC_KX_handle_pong (struct GSC_KeyExchangeInfo *kx,
1192 const struct GNUNET_MessageHeader *msg)
1194 const struct PongMessage *m;
1195 struct PongMessage t;
1196 struct GNUNET_CRYPTO_SymmetricInitializationVector iv;
1199 msize = ntohs (msg->size);
1200 if (sizeof (struct PongMessage) != msize)
1202 GNUNET_break_op (0);
1205 GNUNET_STATISTICS_update (GSC_stats,
1206 gettext_noop ("# PONG messages received"),
1211 case GNUNET_CORE_KX_STATE_DOWN:
1212 GNUNET_STATISTICS_update (GSC_stats,
1213 gettext_noop ("# PONG messages dropped (connection down)"), 1,
1216 case GNUNET_CORE_KX_STATE_KEY_SENT:
1217 GNUNET_STATISTICS_update (GSC_stats,
1218 gettext_noop ("# PONG messages dropped (out of order)"), 1,
1221 case GNUNET_CORE_KX_STATE_KEY_RECEIVED:
1223 case GNUNET_CORE_KX_STATE_UP:
1225 case GNUNET_CORE_KX_STATE_REKEY_SENT:
1231 m = (const struct PongMessage *) msg;
1232 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1233 "Core service receives PONG response from `%s'.\n",
1234 GNUNET_i2s (&kx->peer));
1235 /* mark as garbage, just to be sure */
1236 memset (&t, 255, sizeof (t));
1237 derive_pong_iv (&iv,
1247 sizeof (struct PongMessage) - ((void *) &m->challenge -
1250 GNUNET_break_op (0);
1253 GNUNET_STATISTICS_update (GSC_stats,
1254 gettext_noop ("# PONG messages decrypted"),
1257 if ((0 != memcmp (&t.target,
1259 sizeof (struct GNUNET_PeerIdentity))) ||
1260 (kx->ping_challenge != t.challenge))
1262 /* PONG malformed */
1263 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1264 "Received malformed PONG wanted sender `%s' with challenge %u\n",
1265 GNUNET_i2s (&kx->peer),
1266 (unsigned int) kx->ping_challenge);
1267 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1268 "Received malformed PONG received from `%s' with challenge %u\n",
1269 GNUNET_i2s (&t.target),
1270 (unsigned int) t.challenge);
1273 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1274 "Received PONG from `%s'\n",
1275 GNUNET_i2s (&kx->peer));
1276 /* no need to resend key any longer */
1277 if (NULL != kx->retry_set_key_task)
1279 GNUNET_SCHEDULER_cancel (kx->retry_set_key_task);
1280 kx->retry_set_key_task = NULL;
1284 case GNUNET_CORE_KX_STATE_DOWN:
1285 GNUNET_assert (0); /* should be impossible */
1287 case GNUNET_CORE_KX_STATE_KEY_SENT:
1288 GNUNET_assert (0); /* should be impossible */
1290 case GNUNET_CORE_KX_STATE_KEY_RECEIVED:
1291 GNUNET_STATISTICS_update (GSC_stats,
1292 gettext_noop ("# session keys confirmed via PONG"),
1295 kx->status = GNUNET_CORE_KX_STATE_UP;
1296 monitor_notify_all (kx);
1297 GSC_SESSIONS_create (&kx->peer, kx);
1298 GNUNET_assert (NULL == kx->keep_alive_task);
1299 update_timeout (kx);
1301 case GNUNET_CORE_KX_STATE_UP:
1302 GNUNET_STATISTICS_update (GSC_stats,
1303 gettext_noop ("# timeouts prevented via PONG"),
1306 update_timeout (kx);
1308 case GNUNET_CORE_KX_STATE_REKEY_SENT:
1309 GNUNET_STATISTICS_update (GSC_stats,
1310 gettext_noop ("# rekey operations confirmed via PONG"),
1313 kx->status = GNUNET_CORE_KX_STATE_UP;
1314 monitor_notify_all (kx);
1315 update_timeout (kx);
1325 * Send our key to the other peer.
1327 * @param kx key exchange context
1330 send_key (struct GSC_KeyExchangeInfo *kx)
1332 GNUNET_assert (GNUNET_CORE_KX_STATE_DOWN != kx->status);
1333 if (NULL != kx->retry_set_key_task)
1335 GNUNET_SCHEDULER_cancel (kx->retry_set_key_task);
1336 kx->retry_set_key_task = NULL;
1338 /* always update sender status in SET KEY message */
1339 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1340 "Sending key to `%s' (my status: %d)\n",
1341 GNUNET_i2s (&kx->peer),
1343 current_ekm.sender_status = htonl ((int32_t) (kx->status));
1344 GSC_NEIGHBOURS_transmit (&kx->peer,
1345 ¤t_ekm.header,
1346 kx->set_key_retry_frequency);
1347 if (GNUNET_CORE_KX_STATE_KEY_SENT != kx->status)
1349 kx->retry_set_key_task =
1350 GNUNET_SCHEDULER_add_delayed (kx->set_key_retry_frequency,
1351 &set_key_retry_task,
1357 * Encrypt and transmit a message with the given payload.
1359 * @param kx key exchange context
1360 * @param payload payload of the message
1361 * @param payload_size number of bytes in @a payload
1364 GSC_KX_encrypt_and_transmit (struct GSC_KeyExchangeInfo *kx,
1365 const void *payload,
1366 size_t payload_size)
1368 size_t used = payload_size + sizeof (struct EncryptedMessage);
1369 char pbuf[used]; /* plaintext */
1370 char cbuf[used]; /* ciphertext */
1371 struct EncryptedMessage *em; /* encrypted message */
1372 struct EncryptedMessage *ph; /* plaintext header */
1373 struct GNUNET_CRYPTO_SymmetricInitializationVector iv;
1374 struct GNUNET_CRYPTO_AuthKey auth_key;
1376 ph = (struct EncryptedMessage *) pbuf;
1377 ph->sequence_number = htonl (++kx->last_sequence_number_sent);
1378 ph->iv_seed = calculate_seed (kx);
1380 ph->timestamp = GNUNET_TIME_absolute_hton (GNUNET_TIME_absolute_get ());
1385 em = (struct EncryptedMessage *) cbuf;
1386 em->header.size = htons (used);
1387 em->header.type = htons (GNUNET_MESSAGE_TYPE_CORE_ENCRYPTED_MESSAGE);
1388 em->iv_seed = ph->iv_seed;
1393 GNUNET_assert (GNUNET_OK ==
1396 &ph->sequence_number,
1397 &em->sequence_number,
1398 used - ENCRYPTED_HEADER_SIZE));
1399 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1400 "Encrypted %u bytes for %s\n",
1401 used - ENCRYPTED_HEADER_SIZE,
1402 GNUNET_i2s (&kx->peer));
1403 derive_auth_key (&auth_key,
1406 GNUNET_CRYPTO_hmac (&auth_key,
1407 &em->sequence_number,
1408 used - ENCRYPTED_HEADER_SIZE,
1410 GSC_NEIGHBOURS_transmit (&kx->peer,
1412 GNUNET_TIME_UNIT_FOREVER_REL);
1417 * Closure for #deliver_message()
1419 struct DeliverMessageContext
1423 * Key exchange context.
1425 struct GSC_KeyExchangeInfo *kx;
1428 * Sender of the message.
1430 const struct GNUNET_PeerIdentity *peer;
1435 * We received an encrypted message. Decrypt, validate and
1436 * pass on to the appropriate clients.
1438 * @param kx key exchange context for encrypting the message
1439 * @param msg encrypted message
1442 GSC_KX_handle_encrypted_message (struct GSC_KeyExchangeInfo *kx,
1443 const struct GNUNET_MessageHeader *msg)
1445 const struct EncryptedMessage *m;
1446 struct EncryptedMessage *pt; /* plaintext */
1447 struct GNUNET_HashCode ph;
1449 struct GNUNET_TIME_Absolute t;
1450 struct GNUNET_CRYPTO_SymmetricInitializationVector iv;
1451 struct GNUNET_CRYPTO_AuthKey auth_key;
1452 struct DeliverMessageContext dmc;
1453 uint16_t size = ntohs (msg->size);
1454 char buf[size] GNUNET_ALIGN;
1457 sizeof (struct EncryptedMessage) + sizeof (struct GNUNET_MessageHeader))
1459 GNUNET_break_op (0);
1462 m = (const struct EncryptedMessage *) msg;
1463 if (GNUNET_CORE_KX_STATE_UP != kx->status)
1465 GNUNET_STATISTICS_update (GSC_stats,
1466 gettext_noop ("# DATA message dropped (out of order)"),
1471 if (0 == GNUNET_TIME_absolute_get_remaining (kx->foreign_key_expires).rel_value_us)
1473 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
1474 _("Session to peer `%s' went down due to key expiration (should not happen)\n"),
1475 GNUNET_i2s (&kx->peer));
1476 GNUNET_STATISTICS_update (GSC_stats,
1477 gettext_noop ("# sessions terminated by key expiration"),
1479 GSC_SESSIONS_end (&kx->peer);
1480 if (NULL != kx->keep_alive_task)
1482 GNUNET_SCHEDULER_cancel (kx->keep_alive_task);
1483 kx->keep_alive_task = NULL;
1485 kx->status = GNUNET_CORE_KX_STATE_KEY_SENT;
1486 monitor_notify_all (kx);
1492 derive_auth_key (&auth_key,
1495 GNUNET_CRYPTO_hmac (&auth_key,
1496 &m->sequence_number,
1497 size - ENCRYPTED_HEADER_SIZE,
1499 if (0 != memcmp (&ph,
1501 sizeof (struct GNUNET_HashCode)))
1503 /* checksum failed */
1504 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1505 "Failed checksum validation for a message from `%s'\n",
1506 GNUNET_i2s (&kx->peer));
1517 &m->sequence_number,
1518 &buf[ENCRYPTED_HEADER_SIZE],
1519 size - ENCRYPTED_HEADER_SIZE))
1521 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1522 "Decrypted %u bytes from %s\n",
1523 size - ENCRYPTED_HEADER_SIZE,
1524 GNUNET_i2s (&kx->peer));
1525 pt = (struct EncryptedMessage *) buf;
1527 /* validate sequence number */
1528 snum = ntohl (pt->sequence_number);
1529 if (kx->last_sequence_number_received == snum)
1531 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1532 "Received duplicate message, ignoring.\n");
1533 /* duplicate, ignore */
1534 GNUNET_STATISTICS_update (GSC_stats,
1535 gettext_noop ("# bytes dropped (duplicates)"),
1540 if ((kx->last_sequence_number_received > snum) &&
1541 (kx->last_sequence_number_received - snum > 32))
1543 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1544 "Received ancient out of sequence message, ignoring.\n");
1545 /* ancient out of sequence, ignore */
1546 GNUNET_STATISTICS_update (GSC_stats,
1548 ("# bytes dropped (out of sequence)"), size,
1552 if (kx->last_sequence_number_received > snum)
1554 unsigned int rotbit = 1 << (kx->last_sequence_number_received - snum - 1);
1556 if ((kx->last_packets_bitmap & rotbit) != 0)
1558 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1559 "Received duplicate message, ignoring.\n");
1560 GNUNET_STATISTICS_update (GSC_stats,
1561 gettext_noop ("# bytes dropped (duplicates)"),
1563 /* duplicate, ignore */
1566 kx->last_packets_bitmap |= rotbit;
1568 if (kx->last_sequence_number_received < snum)
1570 unsigned int shift = (snum - kx->last_sequence_number_received);
1572 if (shift >= 8 * sizeof (kx->last_packets_bitmap))
1573 kx->last_packets_bitmap = 0;
1575 kx->last_packets_bitmap <<= shift;
1576 kx->last_sequence_number_received = snum;
1579 /* check timestamp */
1580 t = GNUNET_TIME_absolute_ntoh (pt->timestamp);
1581 if (GNUNET_TIME_absolute_get_duration (t).rel_value_us >
1582 MAX_MESSAGE_AGE.rel_value_us)
1584 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1585 "Message received far too old (%s). Content ignored.\n",
1586 GNUNET_STRINGS_relative_time_to_string (GNUNET_TIME_absolute_get_duration (t),
1588 GNUNET_STATISTICS_update (GSC_stats,
1590 ("# bytes dropped (ancient message)"), size,
1595 /* process decrypted message(s) */
1596 update_timeout (kx);
1597 GNUNET_STATISTICS_update (GSC_stats,
1598 gettext_noop ("# bytes of payload decrypted"),
1599 size - sizeof (struct EncryptedMessage),
1602 dmc.peer = &kx->peer;
1604 GNUNET_SERVER_mst_receive (mst, &dmc,
1605 &buf[sizeof (struct EncryptedMessage)],
1606 size - sizeof (struct EncryptedMessage),
1609 GNUNET_break_op (0);
1614 * Deliver P2P message to interested clients.
1615 * Invokes send twice, once for clients that want the full message, and once
1616 * for clients that only want the header
1618 * @param cls always NULL
1619 * @param client who sent us the message (struct GSC_KeyExchangeInfo)
1620 * @param m the message
1623 deliver_message (void *cls,
1625 const struct GNUNET_MessageHeader *m)
1627 struct DeliverMessageContext *dmc = client;
1629 if (GNUNET_CORE_KX_STATE_UP != dmc->kx->status)
1631 GNUNET_STATISTICS_update (GSC_stats,
1632 gettext_noop ("# PAYLOAD dropped (out of order)"),
1637 switch (ntohs (m->type))
1639 case GNUNET_MESSAGE_TYPE_CORE_BINARY_TYPE_MAP:
1640 case GNUNET_MESSAGE_TYPE_CORE_COMPRESSED_TYPE_MAP:
1641 GSC_SESSIONS_set_typemap (dmc->peer, m);
1643 case GNUNET_MESSAGE_TYPE_CORE_CONFIRM_TYPE_MAP:
1644 GSC_SESSIONS_confirm_typemap (dmc->peer, m);
1647 GSC_CLIENTS_deliver_message (dmc->peer, m,
1649 GNUNET_CORE_OPTION_SEND_FULL_INBOUND);
1650 GSC_CLIENTS_deliver_message (dmc->peer, m,
1651 sizeof (struct GNUNET_MessageHeader),
1652 GNUNET_CORE_OPTION_SEND_HDR_INBOUND);
1659 * Setup the message that links the ephemeral key to our persistent
1660 * public key and generate the appropriate signature.
1663 sign_ephemeral_key ()
1665 current_ekm.header.size = htons (sizeof (struct EphemeralKeyMessage));
1666 current_ekm.header.type = htons (GNUNET_MESSAGE_TYPE_CORE_EPHEMERAL_KEY);
1667 current_ekm.sender_status = 0; /* to be set later */
1668 current_ekm.purpose.purpose = htonl (GNUNET_SIGNATURE_PURPOSE_SET_ECC_KEY);
1669 current_ekm.purpose.size = htonl (sizeof (struct GNUNET_CRYPTO_EccSignaturePurpose) +
1670 sizeof (struct GNUNET_TIME_AbsoluteNBO) +
1671 sizeof (struct GNUNET_TIME_AbsoluteNBO) +
1672 sizeof (struct GNUNET_CRYPTO_EcdhePublicKey) +
1673 sizeof (struct GNUNET_PeerIdentity));
1674 current_ekm.creation_time = GNUNET_TIME_absolute_hton (GNUNET_TIME_absolute_get ());
1676 GNUNET_CONFIGURATION_get_value_yesno (GSC_cfg,
1678 "USE_EPHEMERAL_KEYS"))
1680 current_ekm.expiration_time = GNUNET_TIME_absolute_hton (GNUNET_TIME_relative_to_absolute (GNUNET_TIME_relative_add (REKEY_FREQUENCY,
1685 current_ekm.expiration_time = GNUNET_TIME_absolute_hton (GNUNET_TIME_UNIT_FOREVER_ABS);
1687 GNUNET_CRYPTO_ecdhe_key_get_public (my_ephemeral_key,
1688 ¤t_ekm.ephemeral_key);
1689 current_ekm.origin_identity = GSC_my_identity;
1690 GNUNET_assert (GNUNET_OK ==
1691 GNUNET_CRYPTO_eddsa_sign (my_private_key,
1692 ¤t_ekm.purpose,
1693 ¤t_ekm.signature));
1698 * Task run to trigger rekeying.
1700 * @param cls closure, NULL
1701 * @param tc scheduler context
1704 do_rekey (void *cls,
1705 const struct GNUNET_SCHEDULER_TaskContext *tc)
1707 struct GSC_KeyExchangeInfo *pos;
1709 rekey_task = GNUNET_SCHEDULER_add_delayed (REKEY_FREQUENCY,
1712 if (NULL != my_ephemeral_key)
1713 GNUNET_free (my_ephemeral_key);
1714 GNUNET_log (GNUNET_ERROR_TYPE_INFO,
1716 my_ephemeral_key = GNUNET_CRYPTO_ecdhe_key_create ();
1717 GNUNET_assert (NULL != my_ephemeral_key);
1718 sign_ephemeral_key ();
1719 for (pos = kx_head; NULL != pos; pos = pos->next)
1721 if (GNUNET_CORE_KX_STATE_UP == pos->status)
1723 pos->status = GNUNET_CORE_KX_STATE_REKEY_SENT;
1724 monitor_notify_all (pos);
1725 derive_session_keys (pos);
1727 if (GNUNET_CORE_KX_STATE_DOWN == pos->status)
1729 pos->status = GNUNET_CORE_KX_STATE_KEY_SENT;
1730 monitor_notify_all (pos);
1732 monitor_notify_all (pos);
1739 * Initialize KX subsystem.
1741 * @param pk private key to use for the peer
1742 * @param server the server of the CORE service
1743 * @return #GNUNET_OK on success, #GNUNET_SYSERR on failure
1746 GSC_KX_init (struct GNUNET_CRYPTO_EddsaPrivateKey *pk,
1747 struct GNUNET_SERVER_Handle *server)
1749 nc = GNUNET_SERVER_notification_context_create (server,
1751 my_private_key = pk;
1752 GNUNET_CRYPTO_eddsa_key_get_public (my_private_key,
1753 &GSC_my_identity.public_key);
1754 my_ephemeral_key = GNUNET_CRYPTO_ecdhe_key_create ();
1755 if (NULL == my_ephemeral_key)
1758 GNUNET_free (my_private_key);
1759 my_private_key = NULL;
1760 return GNUNET_SYSERR;
1762 sign_ephemeral_key ();
1763 rekey_task = GNUNET_SCHEDULER_add_delayed (REKEY_FREQUENCY,
1766 mst = GNUNET_SERVER_mst_create (&deliver_message, NULL);
1772 * Shutdown KX subsystem.
1777 if (NULL != rekey_task)
1779 GNUNET_SCHEDULER_cancel (rekey_task);
1782 if (NULL != my_ephemeral_key)
1784 GNUNET_free (my_ephemeral_key);
1785 my_ephemeral_key = NULL;
1787 if (NULL != my_private_key)
1789 GNUNET_free (my_private_key);
1790 my_private_key = NULL;
1794 GNUNET_SERVER_mst_destroy (mst);
1799 GNUNET_SERVER_notification_context_destroy (nc);
1806 * Handle #GNUNET_MESSAGE_TYPE_CORE_MONITOR_PEERS request. For this
1807 * request type, the client does not have to have transmitted an INIT
1808 * request. All current peers are returned, regardless of which
1809 * message types they accept.
1812 * @param client client sending the iteration request
1813 * @param message iteration request message
1816 GSC_KX_handle_client_monitor_peers (void *cls,
1817 struct GNUNET_SERVER_Client *client,
1818 const struct GNUNET_MessageHeader *message)
1820 struct MonitorNotifyMessage done_msg;
1821 struct GSC_KeyExchangeInfo *kx;
1823 GNUNET_SERVER_receive_done (client, GNUNET_OK);
1824 GNUNET_SERVER_notification_context_add (nc,
1826 for (kx = kx_head; NULL != kx; kx = kx->next)
1827 monitor_notify (client, kx);
1828 done_msg.header.size = htons (sizeof (struct MonitorNotifyMessage));
1829 done_msg.header.type = htons (GNUNET_MESSAGE_TYPE_CORE_MONITOR_NOTIFY);
1830 done_msg.state = htonl ((uint32_t) GNUNET_CORE_KX_ITERATION_FINISHED);
1831 memset (&done_msg.peer, 0, sizeof (struct GNUNET_PeerIdentity));
1832 done_msg.timeout = GNUNET_TIME_absolute_hton (GNUNET_TIME_UNIT_FOREVER_ABS);
1833 GNUNET_SERVER_notification_context_unicast (nc,
1840 /* end of gnunet-service-core_kx.c */