2 This file is part of GNUnet.
3 (C) 2009-2013 Christian Grothoff (and other contributing authors)
5 GNUnet is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published
7 by the Free Software Foundation; either version 3, or (at your
8 option) any later version.
10 GNUnet is distributed in the hope that it will be useful, but
11 WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 General Public License for more details.
15 You should have received a copy of the GNU General Public License
16 along with GNUnet; see the file COPYING. If not, write to the
17 Free Software Foundation, Inc., 59 Temple Place - Suite 330,
18 Boston, MA 02111-1307, USA.
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 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 'origin' asserting the validity of
91 * the given ephemeral key.
93 struct GNUNET_CRYPTO_EccSignature 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 (always for NIST P-521) encoded in a format suitable
112 * for network transmission as created using 'gcry_sexp_sprint'.
114 struct GNUNET_CRYPTO_EccPublicEncryptKey ephemeral_key;
117 * Public key of the signing peer (persistent version, not the ephemeral public key).
119 struct GNUNET_PeerIdentity origin_identity;
125 * We're sending an (encrypted) PING to the other peer to check if he
126 * can decrypt. The other peer should respond with a PONG with the
127 * same content, except this time encrypted with the receiver's key.
132 * Message type is CORE_PING.
134 struct GNUNET_MessageHeader header;
139 uint32_t iv_seed GNUNET_PACKED;
142 * Intended target of the PING, used primarily to check
143 * that decryption actually worked.
145 struct GNUNET_PeerIdentity target;
148 * Random number chosen to make reply harder.
150 uint32_t challenge GNUNET_PACKED;
155 * Response to a PING. Includes data from the original PING.
160 * Message type is CORE_PONG.
162 struct GNUNET_MessageHeader header;
167 uint32_t iv_seed GNUNET_PACKED;
170 * Random number to make faking the reply harder. Must be
171 * first field after header (this is where we start to encrypt!).
173 uint32_t challenge GNUNET_PACKED;
176 * Reserved, always zero.
181 * Intended target of the PING, used primarily to check
182 * that decryption actually worked.
184 struct GNUNET_PeerIdentity target;
189 * Encapsulation for encrypted messages exchanged between
190 * peers. Followed by the actual encrypted data.
192 struct EncryptedMessage
195 * Message type is either CORE_ENCRYPTED_MESSAGE.
197 struct GNUNET_MessageHeader header;
200 * Random value used for IV generation.
202 uint32_t iv_seed GNUNET_PACKED;
205 * MAC of the encrypted message (starting at 'sequence_number'),
206 * used to verify message integrity. Everything after this value
207 * (excluding this value itself) will be encrypted and authenticated.
208 * ENCRYPTED_HEADER_SIZE must be set to the offset of the *next* field.
210 struct GNUNET_HashCode hmac;
213 * Sequence number, in network byte order. This field
214 * must be the first encrypted/decrypted field
216 uint32_t sequence_number GNUNET_PACKED;
219 * Reserved, always zero.
224 * Timestamp. Used to prevent reply of ancient messages
225 * (recent messages are caught with the sequence number).
227 struct GNUNET_TIME_AbsoluteNBO timestamp;
230 GNUNET_NETWORK_STRUCT_END
234 * Number of bytes (at the beginning) of "struct EncryptedMessage"
235 * that are NOT encrypted.
237 #define ENCRYPTED_HEADER_SIZE (offsetof(struct EncryptedMessage, sequence_number))
241 * State machine for our P2P encryption handshake. Everyone starts in
242 * "DOWN", if we receive the other peer's key (other peer initiated)
243 * we start in state RECEIVED (since we will immediately send our
244 * own); otherwise we start in SENT. If we get back a PONG from
245 * within either state, we move up to CONFIRMED (the PONG will always
246 * be sent back encrypted with the key we sent to the other peer).
256 * We've sent our session key.
261 * We've received the other peers session key.
263 KX_STATE_KEY_RECEIVED,
266 * The other peer has confirmed our session key + PING with a PONG
267 * message encrypted with his session key (which we got). Key
273 * We're rekeying (or had a timeout), so we have sent the other peer
274 * our new ephemeral key, but we did not get a matching PONG yet.
275 * This is equivalent to being 'KX_STATE_KEY_RECEIVED', except that
276 * the session is marked as 'up' with sessions (as we don't want to
277 * drop and re-establish P2P connections simply due to rekeying).
285 * Information about the status of a key exchange with another peer.
287 struct GSC_KeyExchangeInfo
293 struct GSC_KeyExchangeInfo *next;
298 struct GSC_KeyExchangeInfo *prev;
301 * Identity of the peer.
303 struct GNUNET_PeerIdentity peer;
306 * PING message we transmit to the other peer.
308 struct PingMessage ping;
311 * Key we use to encrypt our messages for the other peer
312 * (initialized by us when we do the handshake).
314 struct GNUNET_CRYPTO_SymmetricSessionKey encrypt_key;
317 * Key we use to decrypt messages from the other peer
318 * (given to us by the other peer during the handshake).
320 struct GNUNET_CRYPTO_SymmetricSessionKey decrypt_key;
323 * At what time did the other peer generate the decryption key?
325 struct GNUNET_TIME_Absolute foreign_key_expires;
328 * When should the session time out (if there are no PONGs)?
330 struct GNUNET_TIME_Absolute timeout;
333 * At what frequency are we currently re-trying SET_KEY messages?
335 struct GNUNET_TIME_Relative set_key_retry_frequency;
338 * ID of task used for re-trying SET_KEY and PING message.
340 GNUNET_SCHEDULER_TaskIdentifier retry_set_key_task;
343 * ID of task used for sending keep-alive pings.
345 GNUNET_SCHEDULER_TaskIdentifier keep_alive_task;
348 * Bit map indicating which of the 32 sequence numbers before the last
349 * were received (good for accepting out-of-order packets and
350 * estimating reliability of the connection)
352 unsigned int last_packets_bitmap;
355 * last sequence number received on this connection (highest)
357 uint32_t last_sequence_number_received;
360 * last sequence number transmitted
362 uint32_t last_sequence_number_sent;
365 * What was our PING challenge number (for this peer)?
367 uint32_t ping_challenge;
370 * What is our connection status?
372 enum KxStateMachine status;
380 static struct GNUNET_CRYPTO_EccPrivateKey *my_private_key;
383 * Our ephemeral private key.
385 static struct GNUNET_CRYPTO_EccPrivateKey *my_ephemeral_key;
388 * Current message we send for a key exchange.
390 static struct EphemeralKeyMessage current_ekm;
393 * Our message stream tokenizer (for encrypted payload).
395 static struct GNUNET_SERVER_MessageStreamTokenizer *mst;
400 static struct GSC_KeyExchangeInfo *kx_head;
405 static struct GSC_KeyExchangeInfo *kx_tail;
408 * Task scheduled for periodic re-generation (and thus rekeying) of our
411 static GNUNET_SCHEDULER_TaskIdentifier rekey_task;
415 * Derive an authentication key from "set key" information
417 * @param akey authentication key to derive
418 * @param skey session key to use
419 * @param seed seed to use
422 derive_auth_key (struct GNUNET_CRYPTO_AuthKey *akey,
423 const struct GNUNET_CRYPTO_SymmetricSessionKey *skey, uint32_t seed)
425 static const char ctx[] = "authentication key";
427 GNUNET_CRYPTO_hmac_derive_key (akey, skey,
428 &seed, sizeof (seed),
429 skey, sizeof (struct GNUNET_CRYPTO_SymmetricSessionKey),
436 * Derive an IV from packet information
438 * @param iv initialization vector to initialize
439 * @param skey session key to use
440 * @param seed seed to use
441 * @param identity identity of the other peer to use
444 derive_iv (struct GNUNET_CRYPTO_SymmetricInitializationVector *iv,
445 const struct GNUNET_CRYPTO_SymmetricSessionKey *skey, uint32_t seed,
446 const struct GNUNET_PeerIdentity *identity)
448 static const char ctx[] = "initialization vector";
450 GNUNET_CRYPTO_symmetric_derive_iv (iv, skey, &seed, sizeof (seed),
452 sizeof (struct GNUNET_PeerIdentity), ctx,
458 * Derive an IV from pong packet information
460 * @param iv initialization vector to initialize
461 * @param skey session key to use
462 * @param seed seed to use
463 * @param challenge nonce to use
464 * @param identity identity of the other peer to use
467 derive_pong_iv (struct GNUNET_CRYPTO_SymmetricInitializationVector *iv,
468 const struct GNUNET_CRYPTO_SymmetricSessionKey *skey, uint32_t seed,
469 uint32_t challenge, const struct GNUNET_PeerIdentity *identity)
471 static const char ctx[] = "pong initialization vector";
473 GNUNET_CRYPTO_symmetric_derive_iv (iv, skey, &seed, sizeof (seed),
475 sizeof (struct GNUNET_PeerIdentity),
476 &challenge, sizeof (challenge),
483 * Derive an AES key from key material
485 * @param sender peer identity of the sender
486 * @param receiver peer identity of the sender
487 * @param key_material high entropy key material to use
488 * @param skey set to derived session key
491 derive_aes_key (const struct GNUNET_PeerIdentity *sender,
492 const struct GNUNET_PeerIdentity *receiver,
493 const struct GNUNET_HashCode *key_material,
494 struct GNUNET_CRYPTO_SymmetricSessionKey *skey)
496 static const char ctx[] = "aes key generation vector";
498 GNUNET_CRYPTO_kdf (skey, sizeof (struct GNUNET_CRYPTO_SymmetricSessionKey),
500 key_material, sizeof (struct GNUNET_HashCode),
501 sender, sizeof (struct GNUNET_PeerIdentity),
502 receiver, sizeof (struct GNUNET_PeerIdentity),
508 * Encrypt size bytes from in and write the result to out. Use the
509 * key for outbound traffic of the given neighbour.
511 * @param kx key information context
512 * @param iv initialization vector to use
513 * @param in ciphertext
514 * @param out plaintext
515 * @param size size of in/out
516 * @return GNUNET_OK on success
519 do_encrypt (struct GSC_KeyExchangeInfo *kx,
520 const struct GNUNET_CRYPTO_SymmetricInitializationVector *iv,
521 const void *in, void *out, size_t size)
523 if (size != (uint16_t) size)
528 GNUNET_assert (size ==
529 GNUNET_CRYPTO_symmetric_encrypt (in, (uint16_t) size,
530 &kx->encrypt_key, iv, out));
531 GNUNET_STATISTICS_update (GSC_stats, gettext_noop ("# bytes encrypted"), size,
533 /* the following is too sensitive to write to log files by accident,
534 so we require manual intervention to get this one... */
536 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
537 "Encrypted %u bytes for `%4s' using key %u, IV %u\n",
538 (unsigned int) size, GNUNET_i2s (&kx->peer),
539 (unsigned int) kx->encrypt_key.crc32, GNUNET_CRYPTO_crc32_n (iv,
548 * Decrypt size bytes from in and write the result to out. Use the
549 * key for inbound traffic of the given neighbour. This function does
550 * NOT do any integrity-checks on the result.
552 * @param kx key information context
553 * @param iv initialization vector to use
554 * @param in ciphertext
555 * @param out plaintext
556 * @param size size of in/out
557 * @return GNUNET_OK on success
560 do_decrypt (struct GSC_KeyExchangeInfo *kx,
561 const struct GNUNET_CRYPTO_SymmetricInitializationVector *iv,
562 const void *in, void *out, size_t size)
564 if (size != (uint16_t) size)
569 if ( (kx->status != KX_STATE_KEY_RECEIVED) && (kx->status != KX_STATE_UP) &&
570 (kx->status != KX_STATE_REKEY_SENT) )
573 return GNUNET_SYSERR;
576 GNUNET_CRYPTO_symmetric_decrypt (in, (uint16_t) size, &kx->decrypt_key, iv,
580 return GNUNET_SYSERR;
582 GNUNET_STATISTICS_update (GSC_stats, gettext_noop ("# bytes decrypted"), size,
584 /* the following is too sensitive to write to log files by accident,
585 so we require manual intervention to get this one... */
587 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
588 "Decrypted %u bytes from `%4s' using key %u, IV %u\n",
589 (unsigned int) size, GNUNET_i2s (&kx->peer),
590 (unsigned int) kx->decrypt_key.crc32, GNUNET_CRYPTO_crc32_n (iv,
599 * Send our key (and encrypted PING) to the other peer.
601 * @param kx key exchange context
604 send_key (struct GSC_KeyExchangeInfo *kx);
608 * Task that will retry "send_key" if our previous attempt failed.
610 * @param cls our 'struct GSC_KeyExchangeInfo'
611 * @param tc scheduler context
614 set_key_retry_task (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
616 struct GSC_KeyExchangeInfo *kx = cls;
618 kx->retry_set_key_task = GNUNET_SCHEDULER_NO_TASK;
619 kx->set_key_retry_frequency = GNUNET_TIME_STD_BACKOFF (kx->set_key_retry_frequency);
620 GNUNET_assert (KX_STATE_DOWN != kx->status);
626 * Create a fresh PING message for transmission to the other peer.
628 * @param kx key exchange context to create PING for
631 setup_fresh_ping (struct GSC_KeyExchangeInfo *kx)
633 struct PingMessage pp;
634 struct PingMessage *pm;
635 struct GNUNET_CRYPTO_SymmetricInitializationVector iv;
638 pm->header.size = htons (sizeof (struct PingMessage));
639 pm->header.type = htons (GNUNET_MESSAGE_TYPE_CORE_PING);
641 GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX);
642 derive_iv (&iv, &kx->encrypt_key, pm->iv_seed, &kx->peer);
643 pp.challenge = kx->ping_challenge;
644 pp.target = kx->peer;
645 do_encrypt (kx, &iv, &pp.target, &pm->target,
646 sizeof (struct PingMessage) - ((void *) &pm->target -
652 * Start the key exchange with the given peer.
654 * @param pid identity of the peer to do a key exchange with
655 * @return key exchange information context
657 struct GSC_KeyExchangeInfo *
658 GSC_KX_start (const struct GNUNET_PeerIdentity *pid)
660 struct GSC_KeyExchangeInfo *kx;
661 struct GNUNET_HashCode h1;
662 struct GNUNET_HashCode h2;
664 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
665 "Initiating key exchange with `%s'\n",
667 GNUNET_STATISTICS_update (GSC_stats,
668 gettext_noop ("# key exchanges initiated"), 1,
670 kx = GNUNET_malloc (sizeof (struct GSC_KeyExchangeInfo));
672 kx->set_key_retry_frequency = INITIAL_SET_KEY_RETRY_FREQUENCY;
673 GNUNET_CONTAINER_DLL_insert (kx_head,
676 GNUNET_CRYPTO_hash (pid, sizeof (struct GNUNET_PeerIdentity), &h1);
677 GNUNET_CRYPTO_hash (&GSC_my_identity, sizeof (struct GNUNET_PeerIdentity), &h2);
679 if (0 < GNUNET_CRYPTO_hash_cmp (&h1,
682 /* peer with "lower" identity starts KX, otherwise we typically end up
683 with both peers starting the exchange and transmit the 'set key'
685 kx->status = KX_STATE_KEY_SENT;
693 * Stop key exchange with the given peer. Clean up key material.
695 * @param kx key exchange to stop
698 GSC_KX_stop (struct GSC_KeyExchangeInfo *kx)
700 GSC_SESSIONS_end (&kx->peer);
701 GNUNET_STATISTICS_update (GSC_stats, gettext_noop ("# key exchanges stopped"),
703 if (kx->retry_set_key_task != GNUNET_SCHEDULER_NO_TASK)
705 GNUNET_SCHEDULER_cancel (kx->retry_set_key_task);
706 kx->retry_set_key_task = GNUNET_SCHEDULER_NO_TASK;
708 if (kx->keep_alive_task != GNUNET_SCHEDULER_NO_TASK)
710 GNUNET_SCHEDULER_cancel (kx->keep_alive_task);
711 kx->keep_alive_task = GNUNET_SCHEDULER_NO_TASK;
713 GNUNET_CONTAINER_DLL_remove (kx_head,
721 * Send our PING to the other peer.
723 * @param kx key exchange context
726 send_ping (struct GSC_KeyExchangeInfo *kx)
728 GSC_NEIGHBOURS_transmit (&kx->peer, &kx->ping.header,
733 * We received a SET_KEY message. Validate and update
734 * our key material and status.
736 * @param kx key exchange status for the corresponding peer
737 * @param msg the set key message we received
740 GSC_KX_handle_ephemeral_key (struct GSC_KeyExchangeInfo *kx,
741 const struct GNUNET_MessageHeader *msg)
743 const struct EphemeralKeyMessage *m;
744 struct GNUNET_TIME_Absolute start_t;
745 struct GNUNET_TIME_Absolute end_t;
746 struct GNUNET_TIME_Absolute now;
747 enum KxStateMachine sender_status;
749 struct GNUNET_HashCode key_material;
751 size = ntohs (msg->size);
752 if (sizeof (struct EphemeralKeyMessage) != size)
757 m = (const struct EphemeralKeyMessage *) msg;
758 end_t = GNUNET_TIME_absolute_ntoh (m->expiration_time);
759 if ( ( (KX_STATE_KEY_RECEIVED == kx->status) ||
760 (KX_STATE_UP == kx->status) ||
761 (KX_STATE_REKEY_SENT == kx->status) ) &&
762 (end_t.abs_value_us <= kx->foreign_key_expires.abs_value_us) )
764 GNUNET_STATISTICS_update (GSC_stats, gettext_noop ("# old ephemeral keys ignored"),
768 start_t = GNUNET_TIME_absolute_ntoh (m->creation_time);
770 GNUNET_STATISTICS_update (GSC_stats, gettext_noop ("# ephemeral keys received"),
773 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
774 "Core service receives `%s' request from `%4s'.\n", "EPHEMERAL_KEY",
775 GNUNET_i2s (&kx->peer));
777 memcmp (&m->origin_identity,
778 &kx->peer.public_key,
779 sizeof (struct GNUNET_PeerIdentity)))
784 if ((ntohl (m->purpose.size) !=
785 sizeof (struct GNUNET_CRYPTO_EccSignaturePurpose) +
786 sizeof (struct GNUNET_TIME_AbsoluteNBO) +
787 sizeof (struct GNUNET_TIME_AbsoluteNBO) +
788 sizeof (struct GNUNET_CRYPTO_EccPublicSignKey) +
789 sizeof (struct GNUNET_CRYPTO_EccPublicSignKey)) ||
791 GNUNET_CRYPTO_ecc_verify (GNUNET_SIGNATURE_PURPOSE_SET_ECC_KEY,
793 &m->signature, &m->origin_identity.public_key)))
795 /* invalid signature */
799 now = GNUNET_TIME_absolute_get ();
800 if ( (end_t.abs_value_us < GNUNET_TIME_absolute_subtract (now, REKEY_TOLERANCE).abs_value_us) ||
801 (start_t.abs_value_us > GNUNET_TIME_absolute_add (now, REKEY_TOLERANCE).abs_value_us) )
803 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
804 _("Ephemeral key message from peer `%s' rejected as its validity range does not match our system time (%llu not in [%llu,%llu]).\n"),
805 GNUNET_i2s (&kx->peer),
807 start_t.abs_value_us,
812 GNUNET_CRYPTO_ecc_ecdh (my_ephemeral_key,
819 GNUNET_STATISTICS_update (GSC_stats,
820 gettext_noop ("# EPHEMERAL_KEY messages decrypted"), 1,
822 derive_aes_key (&GSC_my_identity,
826 derive_aes_key (&kx->peer,
830 /* fresh key, reset sequence numbers */
831 kx->last_sequence_number_received = 0;
832 kx->last_packets_bitmap = 0;
833 kx->foreign_key_expires = end_t;
834 setup_fresh_ping (kx);
836 /* check if we still need to send the sender our key */
837 sender_status = (enum KxStateMachine) ntohl (m->sender_status);
838 switch (sender_status)
843 case KX_STATE_KEY_SENT:
844 /* fine, need to send our key after updating our status, see below */
846 case KX_STATE_KEY_RECEIVED:
848 case KX_STATE_REKEY_SENT:
849 /* other peer already got our key */
855 /* check if we need to confirm everything is fine via PING + PONG */
859 GNUNET_assert (GNUNET_SCHEDULER_NO_TASK == kx->keep_alive_task);
860 kx->status = KX_STATE_KEY_RECEIVED;
861 if (KX_STATE_KEY_SENT == sender_status)
865 case KX_STATE_KEY_SENT:
866 GNUNET_assert (GNUNET_SCHEDULER_NO_TASK == kx->keep_alive_task);
867 kx->status = KX_STATE_KEY_RECEIVED;
868 if (KX_STATE_KEY_SENT == sender_status)
872 case KX_STATE_KEY_RECEIVED:
873 GNUNET_assert (GNUNET_SCHEDULER_NO_TASK == kx->keep_alive_task);
874 if (KX_STATE_KEY_SENT == sender_status)
879 kx->status = KX_STATE_REKEY_SENT;
880 if (KX_STATE_KEY_SENT == sender_status)
882 /* we got a new key, need to reconfirm! */
885 case KX_STATE_REKEY_SENT:
886 if (KX_STATE_KEY_SENT == sender_status)
888 /* we got a new key, need to reconfirm! */
899 * We received a PING message. Validate and transmit
902 * @param kx key exchange status for the corresponding peer
903 * @param msg the encrypted PING message itself
906 GSC_KX_handle_ping (struct GSC_KeyExchangeInfo *kx,
907 const struct GNUNET_MessageHeader *msg)
909 const struct PingMessage *m;
910 struct PingMessage t;
911 struct PongMessage tx;
912 struct PongMessage tp;
913 struct GNUNET_CRYPTO_SymmetricInitializationVector iv;
916 msize = ntohs (msg->size);
917 if (msize != sizeof (struct PingMessage))
922 GNUNET_STATISTICS_update (GSC_stats,
923 gettext_noop ("# PING messages received"), 1,
925 if ( (kx->status != KX_STATE_KEY_RECEIVED) &&
926 (kx->status != KX_STATE_UP) &&
927 (kx->status != KX_STATE_REKEY_SENT))
930 GNUNET_STATISTICS_update (GSC_stats,
931 gettext_noop ("# PING messages dropped (out of order)"), 1,
935 m = (const struct PingMessage *) msg;
936 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
937 "Core service receives `%s' request from `%4s'.\n", "PING",
938 GNUNET_i2s (&kx->peer));
939 derive_iv (&iv, &kx->decrypt_key, m->iv_seed, &GSC_my_identity);
941 do_decrypt (kx, &iv, &m->target, &t.target,
942 sizeof (struct PingMessage) - ((void *) &m->target -
949 memcmp (&t.target, &GSC_my_identity, sizeof (struct GNUNET_PeerIdentity)))
954 GNUNET_snprintf (sender, sizeof (sender), "%8s", GNUNET_i2s (&kx->peer));
955 GNUNET_snprintf (peer, sizeof (peer), "%8s", GNUNET_i2s (&t.target));
956 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
958 ("Received PING from `%s' for different identity: I am `%s', PONG identity: `%s'\n"),
959 sender, GNUNET_i2s (&GSC_my_identity), peer);
965 tx.challenge = t.challenge;
966 tx.target = t.target;
967 tp.header.type = htons (GNUNET_MESSAGE_TYPE_CORE_PONG);
968 tp.header.size = htons (sizeof (struct PongMessage));
970 GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX);
971 derive_pong_iv (&iv, &kx->encrypt_key, tp.iv_seed, t.challenge, &kx->peer);
972 do_encrypt (kx, &iv, &tx.challenge, &tp.challenge,
973 sizeof (struct PongMessage) - ((void *) &tp.challenge -
975 GNUNET_STATISTICS_update (GSC_stats, gettext_noop ("# PONG messages created"),
977 GSC_NEIGHBOURS_transmit (&kx->peer, &tp.header,
978 GNUNET_TIME_UNIT_FOREVER_REL /* FIXME: timeout */ );
983 * Task triggered when a neighbour entry is about to time out
984 * (and we should prevent this by sending a PING).
986 * @param cls the 'struct GSC_KeyExchangeInfo'
987 * @param tc scheduler context (not used)
990 send_keep_alive (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
992 struct GSC_KeyExchangeInfo *kx = cls;
993 struct GNUNET_TIME_Relative retry;
994 struct GNUNET_TIME_Relative left;
996 kx->keep_alive_task = GNUNET_SCHEDULER_NO_TASK;
997 left = GNUNET_TIME_absolute_get_remaining (kx->timeout);
998 if (0 == left.rel_value_us)
1000 GNUNET_STATISTICS_update (GSC_stats,
1001 gettext_noop ("# sessions terminated by timeout"),
1003 GSC_SESSIONS_end (&kx->peer);
1004 kx->status = KX_STATE_KEY_SENT;
1008 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Sending KEEPALIVE to `%s'\n",
1009 GNUNET_i2s (&kx->peer));
1010 GNUNET_STATISTICS_update (GSC_stats,
1011 gettext_noop ("# keepalive messages sent"), 1,
1013 setup_fresh_ping (kx);
1014 GSC_NEIGHBOURS_transmit (&kx->peer, &kx->ping.header,
1015 kx->set_key_retry_frequency);
1017 GNUNET_TIME_relative_max (GNUNET_TIME_relative_divide (left, 2),
1018 MIN_PING_FREQUENCY);
1019 kx->keep_alive_task =
1020 GNUNET_SCHEDULER_add_delayed (retry, &send_keep_alive, kx);
1025 * We've seen a valid message from the other peer.
1026 * Update the time when the session would time out
1027 * and delay sending our keep alive message further.
1029 * @param kx key exchange where we saw activity
1032 update_timeout (struct GSC_KeyExchangeInfo *kx)
1035 GNUNET_TIME_relative_to_absolute
1036 (GNUNET_CONSTANTS_IDLE_CONNECTION_TIMEOUT);
1037 if (kx->keep_alive_task != GNUNET_SCHEDULER_NO_TASK)
1038 GNUNET_SCHEDULER_cancel (kx->keep_alive_task);
1039 kx->keep_alive_task =
1040 GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_relative_divide
1041 (GNUNET_CONSTANTS_IDLE_CONNECTION_TIMEOUT,
1042 2), &send_keep_alive, kx);
1047 * We received a PONG message. Validate and update our status.
1049 * @param kx key exchange context for the the PONG
1050 * @param msg the encrypted PONG message itself
1053 GSC_KX_handle_pong (struct GSC_KeyExchangeInfo *kx,
1054 const struct GNUNET_MessageHeader *msg)
1056 const struct PongMessage *m;
1057 struct PongMessage t;
1058 struct GNUNET_CRYPTO_SymmetricInitializationVector iv;
1061 msize = ntohs (msg->size);
1062 if (sizeof (struct PongMessage) != msize)
1064 GNUNET_break_op (0);
1067 GNUNET_STATISTICS_update (GSC_stats,
1068 gettext_noop ("# PONG messages received"), 1,
1073 GNUNET_STATISTICS_update (GSC_stats,
1074 gettext_noop ("# PONG messages dropped (connection down)"), 1,
1077 case KX_STATE_KEY_SENT:
1078 GNUNET_STATISTICS_update (GSC_stats,
1079 gettext_noop ("# PONG messages dropped (out of order)"), 1,
1082 case KX_STATE_KEY_RECEIVED:
1086 case KX_STATE_REKEY_SENT:
1092 m = (const struct PongMessage *) msg;
1093 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1094 "Core service receives `%s' response from `%4s'.\n", "PONG",
1095 GNUNET_i2s (&kx->peer));
1096 /* mark as garbage, just to be sure */
1097 memset (&t, 255, sizeof (t));
1098 derive_pong_iv (&iv, &kx->decrypt_key, m->iv_seed, kx->ping_challenge,
1101 do_decrypt (kx, &iv, &m->challenge, &t.challenge,
1102 sizeof (struct PongMessage) - ((void *) &m->challenge -
1105 GNUNET_break_op (0);
1108 GNUNET_STATISTICS_update (GSC_stats,
1109 gettext_noop ("# PONG messages decrypted"), 1,
1111 if ((0 != memcmp (&t.target, &kx->peer, sizeof (struct GNUNET_PeerIdentity)))
1112 || (kx->ping_challenge != t.challenge))
1114 /* PONG malformed */
1115 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1116 "Received malformed `%s' wanted sender `%4s' with challenge %u\n",
1117 "PONG", GNUNET_i2s (&kx->peer),
1118 (unsigned int) kx->ping_challenge);
1119 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1120 "Received malformed `%s' received from `%4s' with challenge %u\n",
1121 "PONG", GNUNET_i2s (&t.target), (unsigned int) t.challenge);
1124 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Received PONG from `%s'\n",
1125 GNUNET_i2s (&kx->peer));
1126 /* no need to resend key any longer */
1127 if (GNUNET_SCHEDULER_NO_TASK != kx->retry_set_key_task)
1129 GNUNET_SCHEDULER_cancel (kx->retry_set_key_task);
1130 kx->retry_set_key_task = GNUNET_SCHEDULER_NO_TASK;
1135 GNUNET_assert (0); /* should be impossible */
1137 case KX_STATE_KEY_SENT:
1138 GNUNET_assert (0); /* should be impossible */
1140 case KX_STATE_KEY_RECEIVED:
1141 GNUNET_STATISTICS_update (GSC_stats,
1143 ("# session keys confirmed via PONG"), 1,
1145 kx->status = KX_STATE_UP;
1146 GSC_SESSIONS_create (&kx->peer, kx);
1147 GNUNET_assert (GNUNET_SCHEDULER_NO_TASK == kx->keep_alive_task);
1148 update_timeout (kx);
1151 GNUNET_STATISTICS_update (GSC_stats,
1153 ("# timeouts prevented via PONG"), 1,
1155 update_timeout (kx);
1157 case KX_STATE_REKEY_SENT:
1158 GNUNET_STATISTICS_update (GSC_stats,
1160 ("# rekey operations confirmed via PONG"), 1,
1162 kx->status = KX_STATE_UP;
1163 update_timeout (kx);
1173 * Send our key to the other peer.
1175 * @param kx key exchange context
1178 send_key (struct GSC_KeyExchangeInfo *kx)
1180 GNUNET_assert (KX_STATE_DOWN != kx->status);
1181 if (GNUNET_SCHEDULER_NO_TASK != kx->retry_set_key_task)
1183 GNUNET_SCHEDULER_cancel (kx->retry_set_key_task);
1184 kx->retry_set_key_task = GNUNET_SCHEDULER_NO_TASK;
1186 /* always update sender status in SET KEY message */
1187 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1188 "Sending key to `%s' (my status: %d)\n",
1189 GNUNET_i2s (&kx->peer),
1191 current_ekm.sender_status = htonl ((int32_t) (kx->status));
1192 GSC_NEIGHBOURS_transmit (&kx->peer, ¤t_ekm.header,
1193 kx->set_key_retry_frequency);
1194 kx->retry_set_key_task =
1195 GNUNET_SCHEDULER_add_delayed (kx->set_key_retry_frequency,
1196 &set_key_retry_task, kx);
1201 * Encrypt and transmit a message with the given payload.
1203 * @param kx key exchange context
1204 * @param payload payload of the message
1205 * @param payload_size number of bytes in 'payload'
1208 GSC_KX_encrypt_and_transmit (struct GSC_KeyExchangeInfo *kx,
1209 const void *payload, size_t payload_size)
1211 size_t used = payload_size + sizeof (struct EncryptedMessage);
1212 char pbuf[used]; /* plaintext */
1213 char cbuf[used]; /* ciphertext */
1214 struct EncryptedMessage *em; /* encrypted message */
1215 struct EncryptedMessage *ph; /* plaintext header */
1216 struct GNUNET_CRYPTO_SymmetricInitializationVector iv;
1217 struct GNUNET_CRYPTO_AuthKey auth_key;
1219 ph = (struct EncryptedMessage *) pbuf;
1221 htonl (GNUNET_CRYPTO_random_u32
1222 (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX));
1223 ph->sequence_number = htonl (++kx->last_sequence_number_sent);
1225 ph->timestamp = GNUNET_TIME_absolute_hton (GNUNET_TIME_absolute_get ());
1226 memcpy (&ph[1], payload, payload_size);
1228 em = (struct EncryptedMessage *) cbuf;
1229 em->header.size = htons (used);
1230 em->header.type = htons (GNUNET_MESSAGE_TYPE_CORE_ENCRYPTED_MESSAGE);
1231 em->iv_seed = ph->iv_seed;
1232 derive_iv (&iv, &kx->encrypt_key, ph->iv_seed, &kx->peer);
1233 GNUNET_assert (GNUNET_OK ==
1234 do_encrypt (kx, &iv, &ph->sequence_number,
1235 &em->sequence_number,
1236 used - ENCRYPTED_HEADER_SIZE));
1237 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Encrypted %u bytes for %s\n",
1238 used - ENCRYPTED_HEADER_SIZE, GNUNET_i2s (&kx->peer));
1239 derive_auth_key (&auth_key,
1242 GNUNET_CRYPTO_hmac (&auth_key, &em->sequence_number,
1243 used - ENCRYPTED_HEADER_SIZE, &em->hmac);
1244 GSC_NEIGHBOURS_transmit (&kx->peer, &em->header,
1245 GNUNET_TIME_UNIT_FOREVER_REL);
1250 * Closure for 'deliver_message'
1252 struct DeliverMessageContext
1256 * Key exchange context.
1258 struct GSC_KeyExchangeInfo *kx;
1261 * Sender of the message.
1263 const struct GNUNET_PeerIdentity *peer;
1268 * We received an encrypted message. Decrypt, validate and
1269 * pass on to the appropriate clients.
1271 * @param kx key exchange context for encrypting the message
1272 * @param msg encrypted message
1275 GSC_KX_handle_encrypted_message (struct GSC_KeyExchangeInfo *kx,
1276 const struct GNUNET_MessageHeader *msg)
1278 const struct EncryptedMessage *m;
1279 struct EncryptedMessage *pt; /* plaintext */
1280 struct GNUNET_HashCode ph;
1282 struct GNUNET_TIME_Absolute t;
1283 struct GNUNET_CRYPTO_SymmetricInitializationVector iv;
1284 struct GNUNET_CRYPTO_AuthKey auth_key;
1285 struct DeliverMessageContext dmc;
1286 uint16_t size = ntohs (msg->size);
1287 char buf[size] GNUNET_ALIGN;
1290 sizeof (struct EncryptedMessage) + sizeof (struct GNUNET_MessageHeader))
1292 GNUNET_break_op (0);
1295 m = (const struct EncryptedMessage *) msg;
1296 if (kx->status != KX_STATE_UP)
1298 GNUNET_STATISTICS_update (GSC_stats,
1300 ("# DATA message dropped (out of order)"),
1304 if (0 == GNUNET_TIME_absolute_get_remaining (kx->foreign_key_expires).rel_value_us)
1306 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
1307 _("Session to peer `%s' went down due to key expiration (should not happen)\n"),
1308 GNUNET_i2s (&kx->peer));
1309 GNUNET_STATISTICS_update (GSC_stats,
1310 gettext_noop ("# sessions terminated by key expiration"),
1312 GSC_SESSIONS_end (&kx->peer);
1313 if (GNUNET_SCHEDULER_NO_TASK != kx->keep_alive_task)
1315 GNUNET_SCHEDULER_cancel (kx->keep_alive_task);
1316 kx->keep_alive_task = GNUNET_SCHEDULER_NO_TASK;
1318 kx->status = KX_STATE_KEY_SENT;
1324 derive_auth_key (&auth_key, &kx->decrypt_key, m->iv_seed);
1325 GNUNET_CRYPTO_hmac (&auth_key, &m->sequence_number,
1326 size - ENCRYPTED_HEADER_SIZE, &ph);
1327 if (0 != memcmp (&ph, &m->hmac, sizeof (struct GNUNET_HashCode)))
1329 /* checksum failed */
1330 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1331 "Failed checksum validation for a message from `%s'\n",
1332 GNUNET_i2s (&kx->peer));
1335 derive_iv (&iv, &kx->decrypt_key, m->iv_seed, &GSC_my_identity);
1338 do_decrypt (kx, &iv, &m->sequence_number, &buf[ENCRYPTED_HEADER_SIZE],
1339 size - ENCRYPTED_HEADER_SIZE))
1341 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Decrypted %u bytes from %s\n",
1342 size - ENCRYPTED_HEADER_SIZE, GNUNET_i2s (&kx->peer));
1343 pt = (struct EncryptedMessage *) buf;
1345 /* validate sequence number */
1346 snum = ntohl (pt->sequence_number);
1347 if (kx->last_sequence_number_received == snum)
1349 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1350 "Received duplicate message, ignoring.\n");
1351 /* duplicate, ignore */
1352 GNUNET_STATISTICS_update (GSC_stats,
1353 gettext_noop ("# bytes dropped (duplicates)"),
1357 if ((kx->last_sequence_number_received > snum) &&
1358 (kx->last_sequence_number_received - snum > 32))
1360 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1361 "Received ancient out of sequence message, ignoring.\n");
1362 /* ancient out of sequence, ignore */
1363 GNUNET_STATISTICS_update (GSC_stats,
1365 ("# bytes dropped (out of sequence)"), size,
1369 if (kx->last_sequence_number_received > snum)
1371 unsigned int rotbit = 1 << (kx->last_sequence_number_received - snum - 1);
1373 if ((kx->last_packets_bitmap & rotbit) != 0)
1375 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1376 "Received duplicate message, ignoring.\n");
1377 GNUNET_STATISTICS_update (GSC_stats,
1378 gettext_noop ("# bytes dropped (duplicates)"),
1380 /* duplicate, ignore */
1383 kx->last_packets_bitmap |= rotbit;
1385 if (kx->last_sequence_number_received < snum)
1387 unsigned int shift = (snum - kx->last_sequence_number_received);
1389 if (shift >= 8 * sizeof (kx->last_packets_bitmap))
1390 kx->last_packets_bitmap = 0;
1392 kx->last_packets_bitmap <<= shift;
1393 kx->last_sequence_number_received = snum;
1396 /* check timestamp */
1397 t = GNUNET_TIME_absolute_ntoh (pt->timestamp);
1398 if (GNUNET_TIME_absolute_get_duration (t).rel_value_us >
1399 MAX_MESSAGE_AGE.rel_value_us)
1401 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1402 "Message received far too old (%s). Content ignored.\n",
1403 GNUNET_STRINGS_relative_time_to_string (GNUNET_TIME_absolute_get_duration (t), GNUNET_YES));
1404 GNUNET_STATISTICS_update (GSC_stats,
1406 ("# bytes dropped (ancient message)"), size,
1411 /* process decrypted message(s) */
1412 update_timeout (kx);
1413 GNUNET_STATISTICS_update (GSC_stats,
1414 gettext_noop ("# bytes of payload decrypted"),
1415 size - sizeof (struct EncryptedMessage), GNUNET_NO);
1417 dmc.peer = &kx->peer;
1419 GNUNET_SERVER_mst_receive (mst, &dmc,
1420 &buf[sizeof (struct EncryptedMessage)],
1421 size - sizeof (struct EncryptedMessage),
1422 GNUNET_YES, GNUNET_NO))
1423 GNUNET_break_op (0);
1428 * Deliver P2P message to interested clients.
1429 * Invokes send twice, once for clients that want the full message, and once
1430 * for clients that only want the header
1432 * @param cls always NULL
1433 * @param client who sent us the message (struct GSC_KeyExchangeInfo)
1434 * @param m the message
1437 deliver_message (void *cls, void *client, const struct GNUNET_MessageHeader *m)
1439 struct DeliverMessageContext *dmc = client;
1441 if (KX_STATE_UP != dmc->kx->status)
1443 GNUNET_STATISTICS_update (GSC_stats,
1445 ("# PAYLOAD dropped (out of order)"),
1449 switch (ntohs (m->type))
1451 case GNUNET_MESSAGE_TYPE_CORE_BINARY_TYPE_MAP:
1452 case GNUNET_MESSAGE_TYPE_CORE_COMPRESSED_TYPE_MAP:
1453 GSC_SESSIONS_set_typemap (dmc->peer, m);
1456 GSC_CLIENTS_deliver_message (dmc->peer, m,
1458 GNUNET_CORE_OPTION_SEND_FULL_INBOUND);
1459 GSC_CLIENTS_deliver_message (dmc->peer, m,
1460 sizeof (struct GNUNET_MessageHeader),
1461 GNUNET_CORE_OPTION_SEND_HDR_INBOUND);
1468 * Setup the message that links the ephemeral key to our persistent
1469 * public key and generate the appropriate signature.
1472 sign_ephemeral_key ()
1474 current_ekm.header.size = htons (sizeof (struct EphemeralKeyMessage));
1475 current_ekm.header.type = htons (GNUNET_MESSAGE_TYPE_CORE_EPHEMERAL_KEY);
1476 current_ekm.sender_status = 0; /* to be set later */
1477 current_ekm.purpose.purpose = htonl (GNUNET_SIGNATURE_PURPOSE_SET_ECC_KEY);
1478 current_ekm.purpose.size = htonl (sizeof (struct GNUNET_CRYPTO_EccSignaturePurpose) +
1479 sizeof (struct GNUNET_TIME_AbsoluteNBO) +
1480 sizeof (struct GNUNET_TIME_AbsoluteNBO) +
1481 sizeof (struct GNUNET_CRYPTO_EccPublicSignKey) +
1482 sizeof (struct GNUNET_CRYPTO_EccPublicSignKey));
1483 current_ekm.creation_time = GNUNET_TIME_absolute_hton (GNUNET_TIME_absolute_get ());
1485 GNUNET_CONFIGURATION_get_value_yesno (GSC_cfg,
1487 "USE_EPHEMERAL_KEYS"))
1489 current_ekm.expiration_time = GNUNET_TIME_absolute_hton (GNUNET_TIME_relative_to_absolute (GNUNET_TIME_relative_add (REKEY_FREQUENCY,
1494 current_ekm.expiration_time = GNUNET_TIME_absolute_hton (GNUNET_TIME_UNIT_FOREVER_ABS);
1496 GNUNET_CRYPTO_ecc_key_get_public_for_encryption (my_ephemeral_key,
1497 ¤t_ekm.ephemeral_key);
1498 current_ekm.origin_identity = GSC_my_identity;
1499 GNUNET_assert (GNUNET_OK ==
1500 GNUNET_CRYPTO_ecc_sign (my_private_key,
1501 ¤t_ekm.purpose,
1502 ¤t_ekm.signature));
1507 * Task run to trigger rekeying.
1509 * @param cls closure, NULL
1510 * @param tc scheduler context
1513 do_rekey (void *cls,
1514 const struct GNUNET_SCHEDULER_TaskContext *tc)
1516 struct GSC_KeyExchangeInfo *pos;
1518 rekey_task = GNUNET_SCHEDULER_add_delayed (REKEY_FREQUENCY,
1521 if (NULL != my_ephemeral_key)
1522 GNUNET_free (my_ephemeral_key);
1523 my_ephemeral_key = GNUNET_CRYPTO_ecc_key_create ();
1524 GNUNET_assert (NULL != my_ephemeral_key);
1525 sign_ephemeral_key ();
1526 for (pos = kx_head; NULL != pos; pos = pos->next)
1528 pos->status = KX_STATE_REKEY_SENT;
1535 * Initialize KX subsystem.
1537 * @param pk private key to use for the peer
1538 * @return GNUNET_OK on success, GNUNET_SYSERR on failure
1541 GSC_KX_init (struct GNUNET_CRYPTO_EccPrivateKey *pk)
1543 GNUNET_assert (NULL != pk);
1544 my_private_key = pk;
1545 GNUNET_CRYPTO_ecc_key_get_public_for_signature (my_private_key,
1546 &GSC_my_identity.public_key);
1548 GNUNET_CONFIGURATION_get_value_yesno (GSC_cfg,
1550 "USE_EPHEMERAL_KEYS"))
1552 my_ephemeral_key = GNUNET_CRYPTO_ecc_key_create ();
1553 if (NULL == my_ephemeral_key)
1556 GNUNET_free (my_private_key);
1557 my_private_key = NULL;
1558 return GNUNET_SYSERR;
1560 sign_ephemeral_key ();
1561 rekey_task = GNUNET_SCHEDULER_add_delayed (REKEY_FREQUENCY,
1567 my_ephemeral_key = my_private_key;
1568 sign_ephemeral_key ();
1570 mst = GNUNET_SERVER_mst_create (&deliver_message, NULL);
1576 * Shutdown KX subsystem.
1581 if (GNUNET_SCHEDULER_NO_TASK != rekey_task)
1583 GNUNET_SCHEDULER_cancel (rekey_task);
1584 rekey_task = GNUNET_SCHEDULER_NO_TASK;
1586 if ( (NULL != my_ephemeral_key) &&
1587 (my_ephemeral_key != my_private_key) )
1589 GNUNET_free (my_ephemeral_key);
1590 my_ephemeral_key = NULL;
1592 if (NULL != my_private_key)
1594 GNUNET_free (my_private_key);
1595 my_private_key = NULL;
1599 GNUNET_SERVER_mst_destroy (mst);
1604 /* end of gnunet-service-core_kx.c */