2 This file is part of GNUnet.
3 (C) 2013 Christian Grothoff (and other contributing authors)
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22 * @file scalarproduct/gnunet-service-scalarproduct.c
23 * @brief scalarproduct service implementation
24 * @author Christian M. Fuchs
28 #include "gnunet_util_lib.h"
29 #include "gnunet_core_service.h"
30 #include "gnunet_mesh_service.h"
31 #include "gnunet_applications.h"
32 #include "gnunet_protocols.h"
33 #include "gnunet_scalarproduct_service.h"
34 #include "scalarproduct.h"
36 #define LOG(kind,...) GNUNET_log_from (kind, "scalarproduct", __VA_ARGS__)
38 ///////////////////////////////////////////////////////////////////////////////
39 // Service Structure Definitions
40 ///////////////////////////////////////////////////////////////////////////////
44 * state a session can be in
48 CLIENT_REQUEST_RECEIVED,
49 WAITING_FOR_BOBS_CONNECT,
50 CLIENT_RESPONSE_RECEIVED,
51 WAITING_FOR_SERVICE_REQUEST,
52 WAITING_FOR_MULTIPART_TRANSMISSION,
53 WAITING_FOR_SERVICE_RESPONSE,
54 SERVICE_REQUEST_RECEIVED,
55 SERVICE_RESPONSE_RECEIVED,
61 * role a peer in a session can assume
71 * A scalarproduct session which tracks:
73 * a request form the client to our final response.
75 * a request from a service to us(service).
80 * the role this peer has
85 * session information is kept in a DLL
87 struct ServiceSession *next;
90 * session information is kept in a DLL
92 struct ServiceSession *prev;
95 * (hopefully) unique transaction ID
97 struct GNUNET_HashCode key;
100 * state of the session
102 enum SessionState state;
105 * Alice or Bob's peerID
107 struct GNUNET_PeerIdentity peer;
110 * the client this request is related to
112 struct GNUNET_SERVER_Client * client;
115 * The message to send
117 struct GNUNET_MessageHeader * msg;
120 * how many elements we were supplied with from the client
125 * how many elements actually are used after applying the mask
130 * already transferred elements (sent/received) for multipart messages, less or equal than used_element_count for
132 uint32_t transferred;
135 * index of the last transferred element for multipart messages
137 uint32_t last_processed;
140 * how many bytes the mask is long.
141 * just for convenience so we don't have to re-re-re calculate it each time
143 uint32_t mask_length;
146 * all the vector elements we received
151 * mask of which elements to check
153 unsigned char * mask;
156 * Public key of the remote service, only used by bob
158 gcry_sexp_t remote_pubkey;
161 * E(ai)(Bob) or ai(Alice) after applying the mask
166 * Bob's permutation p of R
171 * Bob's permutation q of R
173 gcry_mpi_t * r_prime;
186 * Bobs matching response session from the client
188 struct ServiceSession * response;
191 * The computed scalar
196 * My transmit handle for the current message to a alice/bob
198 struct GNUNET_MESH_TransmitHandle * service_transmit_handle;
201 * My transmit handle for the current message to the client
203 struct GNUNET_SERVER_TransmitHandle * client_transmit_handle;
206 * tunnel-handle associated with our mesh handle
208 struct GNUNET_MESH_Tunnel * tunnel;
211 * Handle to a task that sends a msg to the our client
213 GNUNET_SCHEDULER_TaskIdentifier client_notification_task;
216 * Handle to a task that sends a msg to the our peer
218 GNUNET_SCHEDULER_TaskIdentifier service_request_task;
221 ///////////////////////////////////////////////////////////////////////////////
222 // Forward Delcarations
223 ///////////////////////////////////////////////////////////////////////////////
226 * Send a multi part chunk of a service request from alice to bob.
227 * This element only contains a part of the elements-vector (session->a[]),
228 * mask and public key set have to be contained within the first message
230 * This allows a ~32kbit key length while using 32000 elements or 62000 elements per request.
232 * @param cls the associated service session
235 prepare_service_request_multipart (void *cls);
238 * Send a multi part chunk of a service response from bob to alice.
239 * This element only contains the two permutations of R, R'.
241 * @param cls the associated service session
244 prepare_service_response_multipart (void *cls);
247 ///////////////////////////////////////////////////////////////////////////////
249 ///////////////////////////////////////////////////////////////////////////////
253 * Handle to the core service (NULL until we've connected to it).
255 static struct GNUNET_MESH_Handle *my_mesh;
258 * The identity of this host.
260 static struct GNUNET_PeerIdentity me;
263 * Service's own public key represented as string
265 static unsigned char * my_pubkey_external;
268 * Service's own public key represented as string
270 static uint32_t my_pubkey_external_length = 0;
275 static gcry_mpi_t my_n;
278 * Service's own n^2 (kept for performance)
280 static gcry_mpi_t my_nsquare;
283 * Service's own public exponent
285 static gcry_mpi_t my_g;
288 * Service's own private multiplier
290 static gcry_mpi_t my_mu;
293 * Service's own private exponent
295 static gcry_mpi_t my_lambda;
298 * Service's offset for values that could possibly be negative but are plaintext for encryption.
300 static gcry_mpi_t my_offset;
303 * Head of our double linked list for client-requests sent to us.
304 * for all of these elements we calculate a scalar product with a remote peer
305 * split between service->service and client->service for simplicity
307 static struct ServiceSession * from_client_head;
309 * Tail of our double linked list for client-requests sent to us.
310 * for all of these elements we calculate a scalar product with a remote peer
311 * split between service->service and client->service for simplicity
313 static struct ServiceSession * from_client_tail;
316 * Head of our double linked list for service-requests sent to us.
317 * for all of these elements we help the requesting service in calculating a scalar product
318 * split between service->service and client->service for simplicity
320 static struct ServiceSession * from_service_head;
323 * Tail of our double linked list for service-requests sent to us.
324 * for all of these elements we help the requesting service in calculating a scalar product
325 * split between service->service and client->service for simplicity
327 static struct ServiceSession * from_service_tail;
330 * Certain events (callbacks for server & mesh operations) must not be queued after shutdown.
332 static int do_shutdown;
334 ///////////////////////////////////////////////////////////////////////////////
336 ///////////////////////////////////////////////////////////////////////////////
340 * Generates an Paillier private/public keyset and extracts the values using libgrcypt only
345 gcry_sexp_t gen_params;
347 gcry_sexp_t tmp_sexp;
356 // we can still use the RSA keygen for generating p,q,n, but using e is pointless.
357 GNUNET_assert (0 == gcry_sexp_build (&gen_params, &erroff,
358 "(genkey(rsa(nbits %d)(rsa-use-e 3:257)))",
361 GNUNET_assert (0 == gcry_pk_genkey (&key, gen_params));
362 gcry_sexp_release (gen_params);
364 // get n and d of our publickey as MPI
365 tmp_sexp = gcry_sexp_find_token (key, "n", 0);
366 GNUNET_assert (tmp_sexp);
367 my_n = gcry_sexp_nth_mpi (tmp_sexp, 1, GCRYMPI_FMT_USG);
368 gcry_sexp_release (tmp_sexp);
369 tmp_sexp = gcry_sexp_find_token (key, "p", 0);
370 GNUNET_assert (tmp_sexp);
371 p = gcry_sexp_nth_mpi (tmp_sexp, 1, GCRYMPI_FMT_USG);
372 gcry_sexp_release (tmp_sexp);
373 tmp_sexp = gcry_sexp_find_token (key, "q", 0);
374 GNUNET_assert (tmp_sexp);
375 q = gcry_sexp_nth_mpi (tmp_sexp, 1, GCRYMPI_FMT_USG);
376 gcry_sexp_release (key);
378 tmp1 = gcry_mpi_new (0);
379 tmp2 = gcry_mpi_new (0);
380 gcd = gcry_mpi_new (0);
381 my_g = gcry_mpi_new (0);
382 my_mu = gcry_mpi_new (0);
383 my_nsquare = gcry_mpi_new (0);
384 my_lambda = gcry_mpi_new (0);
387 // lambda = frac{(p-1)*(q-1)}{gcd(p-1,q-1)}
388 gcry_mpi_sub_ui (tmp1, p, 1);
389 gcry_mpi_sub_ui (tmp2, q, 1);
390 gcry_mpi_gcd (gcd, tmp1, tmp2);
391 gcry_mpi_set (my_lambda, tmp1);
392 gcry_mpi_mul (my_lambda, my_lambda, tmp2);
393 gcry_mpi_div (my_lambda, NULL, my_lambda, gcd, 0);
396 gcry_mpi_mul (my_nsquare, my_n, my_n);
400 gcry_mpi_randomize (my_g, KEYBITS * 2, GCRY_WEAK_RANDOM);
401 // g must be smaller than n^2
402 if (0 >= gcry_mpi_cmp (my_g, my_nsquare))
405 // g must have gcd == 1 with n^2
406 gcry_mpi_gcd (gcd, my_g, my_nsquare);
408 while (gcry_mpi_cmp_ui (gcd, 1));
410 // is this a valid g?
411 // if so, gcd(((g^lambda mod n^2)-1 )/n, n) = 1
412 gcry_mpi_powm (tmp1, my_g, my_lambda, my_nsquare);
413 gcry_mpi_sub_ui (tmp1, tmp1, 1);
414 gcry_mpi_div (tmp1, NULL, tmp1, my_n, 0);
415 gcry_mpi_gcd (gcd, tmp1, my_n);
417 while (gcry_mpi_cmp_ui (gcd, 1));
419 // calculate our mu based on g and n.
420 // mu = (((g^lambda mod n^2)-1 )/n)^-1 mod n
421 gcry_mpi_invm (my_mu, tmp1, my_n);
423 GNUNET_assert (0 == gcry_sexp_build (&key, &erroff,
424 "(public-key (paillier (n %M)(g %M)))",
427 // get the length of this sexpression
428 my_pubkey_external_length = gcry_sexp_sprint (key,
433 GNUNET_assert (my_pubkey_external_length > 0);
434 my_pubkey_external = GNUNET_malloc (my_pubkey_external_length);
436 // convert the sexpression to canonical format
437 gcry_sexp_sprint (key,
440 my_pubkey_external_length);
442 gcry_sexp_release (key);
444 // offset has to be sufficiently small to allow computation of:
445 // m1+m2 mod n == (S + a) + (S + b) mod n,
446 // if we have more complex operations, this factor needs to be lowered
447 my_offset = gcry_mpi_new (KEYBITS / 3);
448 gcry_mpi_set_bit (my_offset, KEYBITS / 3);
450 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, _ ("Generated key set with key length %d bits.\n"), KEYBITS);
455 * If target != size, move target bytes to the
456 * end of the size-sized buffer and zero out the
457 * first target-size bytes.
459 * @param buf original buffer
460 * @param size number of bytes in the buffer
461 * @param target target size of the buffer
464 adjust (unsigned char *buf, size_t size, size_t target)
467 memmove (&buf[target - size], buf, size);
468 memset (buf, 0, target - size);
474 * Encrypts an element using the paillier crypto system
476 * @param c ciphertext (output)
478 * @param g the public base
479 * @param n the module from which which r is chosen (Z*_n)
480 * @param n_square the module for encryption, for performance reasons.
483 encrypt_element (gcry_mpi_t c, gcry_mpi_t m, gcry_mpi_t g, gcry_mpi_t n, gcry_mpi_t n_square)
487 GNUNET_assert (tmp = gcry_mpi_new (0));
489 while (0 >= gcry_mpi_cmp_ui (tmp, 1)) {
490 gcry_mpi_randomize (tmp, KEYBITS / 3, GCRY_WEAK_RANDOM);
491 // r must be 1 < r < n
494 gcry_mpi_powm (c, g, m, n_square);
495 gcry_mpi_powm (tmp, tmp, n, n_square);
496 gcry_mpi_mulm (c, tmp, c, n_square);
498 gcry_mpi_release (tmp);
503 * decrypts an element using the paillier crypto system
505 * @param m plaintext (output)
506 * @param c the ciphertext
507 * @param mu the modifier to correct encryption
508 * @param lambda the private exponent
509 * @param n the outer module for decryption
510 * @param n_square the inner module for decryption
513 decrypt_element (gcry_mpi_t m, gcry_mpi_t c, gcry_mpi_t mu, gcry_mpi_t lambda, gcry_mpi_t n, gcry_mpi_t n_square)
515 gcry_mpi_powm (m, c, lambda, n_square);
516 gcry_mpi_sub_ui (m, m, 1);
517 gcry_mpi_div (m, NULL, m, n, 0);
518 gcry_mpi_mulm (m, m, mu, n);
523 * computes the square sum over a vector of a given length.
525 * @param vector the vector to encrypt
526 * @param length the length of the vector
527 * @return an MPI value containing the calculated sum, never NULL
530 compute_square_sum (gcry_mpi_t * vector, uint32_t length)
536 GNUNET_assert (sum = gcry_mpi_new (0));
537 GNUNET_assert (elem = gcry_mpi_new (0));
539 // calculare E(sum (ai ^ 2), publickey)
540 for (i = 0; i < length; i++) {
541 gcry_mpi_mul (elem, vector[i], vector[i]);
542 gcry_mpi_add (sum, sum, elem);
544 gcry_mpi_release (elem);
551 * Primitive callback for copying over a message, as they
552 * usually are too complex to be handled in the callback itself.
553 * clears a session-callback, if a session was handed over and the transmit handle was stored
555 * @param cls the message object
556 * @param size the size of the buffer we got
557 * @param buf the buffer to copy the message to
558 * @return 0 if we couldn't copy, else the size copied over
561 do_send_message (void *cls, size_t size, void *buf)
563 struct ServiceSession * session = cls;
568 if (ntohs (session->msg->size) != size) {
573 type = ntohs (session->msg->type);
574 memcpy (buf, session->msg, size);
575 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
576 "Sent a message of type %hu.\n",
578 GNUNET_free (session->msg);
583 case GNUNET_MESSAGE_TYPE_SCALARPRODUCT_SERVICE_TO_CLIENT:
584 session->state = FINALIZED;
585 session->client_transmit_handle = NULL;
588 case GNUNET_MESSAGE_TYPE_SCALARPRODUCT_ALICE_TO_BOB:
589 case GNUNET_MESSAGE_TYPE_SCALARPRODUCT_ALICE_TO_BOB_MULTIPART:
590 session->service_transmit_handle = NULL;
591 if (session->state == WAITING_FOR_MULTIPART_TRANSMISSION)
592 prepare_service_request_multipart (session);
595 case GNUNET_MESSAGE_TYPE_SCALARPRODUCT_BOB_TO_ALICE:
596 case GNUNET_MESSAGE_TYPE_SCALARPRODUCT_BOB_TO_ALICE_MULTIPART:
597 session->service_transmit_handle = NULL;
598 if (session->state == WAITING_FOR_MULTIPART_TRANSMISSION)
599 prepare_service_response_multipart (session);
611 * initializes a new vector with fresh MPI values (=0) of a given length
613 * @param length of the vector to create
614 * @return the initialized vector, never NULL
617 initialize_mpi_vector (uint32_t length)
620 gcry_mpi_t * output = GNUNET_malloc (sizeof (gcry_mpi_t) * length);
622 for (i = 0; i < length; i++)
623 GNUNET_assert (NULL != (output[i] = gcry_mpi_new (0)));
629 * permutes an MPI vector according to the given permutation vector
631 * @param vector the vector to permuted
632 * @param perm the permutation to use
633 * @param length the length of the vectors
634 * @return the permuted vector (same as input), never NULL
637 permute_vector (gcry_mpi_t * vector,
641 gcry_mpi_t tmp[length];
644 GNUNET_assert (length > 0);
647 memcpy (tmp, vector, length * sizeof (gcry_mpi_t));
649 // permute vector according to given
650 for (i = 0; i < length; i++)
651 vector[i] = tmp[perm[i]];
658 * Finds a not terminated client/service session in the
659 * given DLL based on session key, element count and state.
661 * @param tail - the tail of the DLL
662 * @param key - the key we want to search for
663 * @param element_count - the total element count of the dataset (session->total)
664 * @param state - a pointer to the state the session should be in, NULL to ignore
665 * @param peerid - a pointer to the peer ID of the associated peer, NULL to ignore
666 * @return a pointer to a matching session, or NULL
668 static struct ServiceSession *
669 find_matching_session (struct ServiceSession * tail,
670 const struct GNUNET_HashCode * key,
671 uint32_t element_count,
672 enum SessionState * state,
673 const struct GNUNET_PeerIdentity * peerid)
675 struct ServiceSession * curr;
677 for (curr = tail; NULL != curr; curr = curr->prev) {
678 // if the key matches, and the element_count is same
679 if ((!memcmp (&curr->key, key, sizeof (struct GNUNET_HashCode)))
680 && (curr->total == element_count)) {
681 // if incoming state is NULL OR is same as state of the queued request
682 if ((NULL == state) || (curr->state == *state)) {
683 // if peerid is NULL OR same as the peer Id in the queued request
685 || (!memcmp (&curr->peer, peerid, sizeof (struct GNUNET_PeerIdentity))))
686 // matches and is not an already terminated session
697 * Safely frees ALL memory areas referenced by a session.
699 * @param session - the session to free elements from
702 free_session_variables (struct ServiceSession * session)
707 for (i = 0; i < session->used; i++)
708 if (session->a[i]) gcry_mpi_release (session->a[i]);
709 GNUNET_free (session->a);
711 GNUNET_free_non_null (session->mask);
713 for (i = 0; i < session->used; i++)
714 if (session->r[i]) gcry_mpi_release (session->r[i]);
715 GNUNET_free (session->r);
717 if (session->r_prime) {
718 for (i = 0; i < session->used; i++)
719 if (session->r_prime[i]) gcry_mpi_release (session->r_prime[i]);
720 GNUNET_free (session->r_prime);
723 gcry_mpi_release (session->s);
724 if (session->s_prime)
725 gcry_mpi_release (session->s_prime);
726 if (session->product)
727 gcry_mpi_release (session->product);
729 if (session->remote_pubkey)
730 gcry_sexp_release (session->remote_pubkey);
732 GNUNET_free_non_null (session->vector);
734 ///////////////////////////////////////////////////////////////////////////////
735 // Event and Message Handlers
736 ///////////////////////////////////////////////////////////////////////////////
740 * A client disconnected.
742 * Remove the associated session(s), release data structures
743 * and cancel pending outgoing transmissions to the client.
744 * if the session has not yet completed, we also cancel Alice's request to Bob.
746 * @param cls closure, NULL
747 * @param client identification of the client
750 handle_client_disconnect (void *cls,
751 struct GNUNET_SERVER_Client *client)
753 struct ServiceSession *session;
757 session = GNUNET_SERVER_client_get_user_context (client, struct ServiceSession);
760 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
761 _ ("Client (%p) disconnected from us.\n"), client);
762 GNUNET_CONTAINER_DLL_remove (from_client_head, from_client_tail, session);
764 if (!(session->role == BOB && session->state == FINALIZED)) {
765 //we MUST terminate any client message underway
766 if (session->service_transmit_handle && session->tunnel)
767 GNUNET_MESH_notify_transmit_ready_cancel (session->service_transmit_handle);
768 if (session->tunnel && session->state == WAITING_FOR_SERVICE_RESPONSE)
769 GNUNET_MESH_tunnel_destroy (session->tunnel);
771 if (GNUNET_SCHEDULER_NO_TASK != session->client_notification_task) {
772 GNUNET_SCHEDULER_cancel (session->client_notification_task);
773 session->client_notification_task = GNUNET_SCHEDULER_NO_TASK;
775 if (GNUNET_SCHEDULER_NO_TASK != session->service_request_task) {
776 GNUNET_SCHEDULER_cancel (session->service_request_task);
777 session->service_request_task = GNUNET_SCHEDULER_NO_TASK;
779 if (NULL != session->client_transmit_handle) {
780 GNUNET_SERVER_notify_transmit_ready_cancel (session->client_transmit_handle);
781 session->client_transmit_handle = NULL;
783 free_session_variables (session);
784 GNUNET_free (session);
789 * Notify the client that the session has succeeded or failed completely.
790 * This message gets sent to
791 * * alice's client if bob disconnected or to
792 * * bob's client if the operation completed or alice disconnected
794 * @param cls the associated client session
795 * @param tc the task context handed to us by the scheduler, unused
798 prepare_client_end_notification (void * cls,
799 const struct GNUNET_SCHEDULER_TaskContext * tc)
801 struct ServiceSession * session = cls;
802 struct GNUNET_SCALARPRODUCT_client_response * msg;
804 session->client_notification_task = GNUNET_SCHEDULER_NO_TASK;
806 msg = GNUNET_new (struct GNUNET_SCALARPRODUCT_client_response);
807 msg->header.type = htons (GNUNET_MESSAGE_TYPE_SCALARPRODUCT_SERVICE_TO_CLIENT);
808 memcpy (&msg->key, &session->key, sizeof (struct GNUNET_HashCode));
809 memcpy (&msg->peer, &session->peer, sizeof ( struct GNUNET_PeerIdentity));
810 msg->header.size = htons (sizeof (struct GNUNET_SCALARPRODUCT_client_response));
811 // signal error if not signalized, positive result-range field but zero length.
812 msg->product_length = htonl (0);
813 msg->range = (session->state == FINALIZED) ? 0 : -1;
815 session->msg = &msg->header;
817 //transmit this message to our client
818 session->client_transmit_handle =
819 GNUNET_SERVER_notify_transmit_ready (session->client,
820 sizeof (struct GNUNET_SCALARPRODUCT_client_response),
821 GNUNET_TIME_UNIT_FOREVER_REL,
825 // if we could not even queue our request, something is wrong
826 if (NULL == session->client_transmit_handle) {
827 GNUNET_log (GNUNET_ERROR_TYPE_WARNING, _ ("Could not send message to client (%p)!\n"), session->client);
828 // usually gets freed by do_send_message
833 GNUNET_log (GNUNET_ERROR_TYPE_INFO, _ ("Sending session-end notification to client (%p) for session %s\n"), &session->client, GNUNET_h2s (&session->key));
839 * prepare the response we will send to alice or bobs' clients.
840 * in Bobs case the product will be NULL.
842 * @param cls the session associated with our client.
843 * @param tc the task context handed to us by the scheduler, unused
846 prepare_client_response (void *cls,
847 const struct GNUNET_SCHEDULER_TaskContext *tc)
849 struct ServiceSession * session = cls;
850 struct GNUNET_SCALARPRODUCT_client_response * msg;
851 unsigned char * product_exported = NULL;
852 size_t product_length = 0;
853 uint32_t msg_length = 0;
858 session->client_notification_task = GNUNET_SCHEDULER_NO_TASK;
860 if (session->product) {
861 gcry_mpi_t value = gcry_mpi_new (0);
863 sign = gcry_mpi_cmp_ui (session->product, 0);
864 // libgcrypt can not handle a print of a negative number
865 // if (a->sign) return gcry_error (GPG_ERR_INTERNAL); /* Can't handle it yet. */
867 gcry_mpi_sub (value, value, session->product);
871 gcry_mpi_add (value, value, session->product);
876 gcry_mpi_release (session->product);
877 session->product = NULL;
879 // get representation as string
881 && (0 != (rc = gcry_mpi_aprint (GCRYMPI_FMT_STD,
885 LOG_GCRY (GNUNET_ERROR_TYPE_ERROR, "gcry_mpi_scan", rc);
887 range = -1; // signal error with product-length = 0 and range = -1
889 gcry_mpi_release (value);
892 msg_length = sizeof (struct GNUNET_SCALARPRODUCT_client_response) +product_length;
893 msg = GNUNET_malloc (msg_length);
894 memcpy (&msg->key, &session->key, sizeof (struct GNUNET_HashCode));
895 memcpy (&msg->peer, &session->peer, sizeof ( struct GNUNET_PeerIdentity));
896 if (product_exported != NULL) {
897 memcpy (&msg[1], product_exported, product_length);
898 GNUNET_free (product_exported);
900 msg->header.type = htons (GNUNET_MESSAGE_TYPE_SCALARPRODUCT_SERVICE_TO_CLIENT);
901 msg->header.size = htons (msg_length);
903 msg->product_length = htonl (product_length);
905 session->msg = (struct GNUNET_MessageHeader *) msg;
906 //transmit this message to our client
907 session->client_transmit_handle =
908 GNUNET_SERVER_notify_transmit_ready (session->client,
910 GNUNET_TIME_UNIT_FOREVER_REL,
913 if (NULL == session->client_transmit_handle) {
914 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
915 _ ("Could not send message to client (%p)!\n"),
917 session->client = NULL;
918 // callback was not called!
923 // gracefully sent message, just terminate session structure
924 GNUNET_log (GNUNET_ERROR_TYPE_INFO,
925 _ ("Sent result to client (%p), this session (%s) has ended!\n"),
927 GNUNET_h2s (&session->key));
932 * Send a multipart chunk of a service response from bob to alice.
933 * This element only contains the two permutations of R, R'.
935 * @param cls the associated service session
938 prepare_service_response_multipart (void *cls)
940 struct ServiceSession * session = cls;
941 unsigned char * current;
942 unsigned char * element_exported;
943 struct GNUNET_SCALARPRODUCT_multipart_message * msg;
947 size_t element_length = 0; // initialized by gcry_mpi_print, but the compiler doesn't know that
949 msg_length = sizeof (struct GNUNET_SCALARPRODUCT_multipart_message);
950 todo_count = session->used - session->transferred;
952 if (todo_count > MULTIPART_ELEMENT_CAPACITY / 2)
953 // send the currently possible maximum chunk, we always transfer both permutations
954 todo_count = MULTIPART_ELEMENT_CAPACITY / 2;
956 msg_length += todo_count * PAILLIER_ELEMENT_LENGTH * 2;
957 msg = GNUNET_malloc (msg_length);
958 msg->header.type = htons (GNUNET_MESSAGE_TYPE_SCALARPRODUCT_ALICE_TO_BOB_MULTIPART);
959 msg->header.size = htons (msg_length);
960 msg->multipart_element_count = htonl (todo_count);
962 element_exported = GNUNET_malloc (PAILLIER_ELEMENT_LENGTH);
963 current = (unsigned char *) &msg[1];
965 for (i = session->transferred; i < session->transferred + todo_count; i++) {
967 memset (element_exported, 0, PAILLIER_ELEMENT_LENGTH);
968 GNUNET_assert (0 == gcry_mpi_print (GCRYMPI_FMT_USG,
969 element_exported, PAILLIER_ELEMENT_LENGTH,
972 adjust (element_exported, element_length, PAILLIER_ELEMENT_LENGTH);
973 memcpy (current, element_exported, PAILLIER_ELEMENT_LENGTH);
974 current += PAILLIER_ELEMENT_LENGTH;
976 memset (element_exported, 0, PAILLIER_ELEMENT_LENGTH);
977 GNUNET_assert (0 == gcry_mpi_print (GCRYMPI_FMT_USG,
978 element_exported, PAILLIER_ELEMENT_LENGTH,
980 session->r_prime[i]));
981 adjust (element_exported, element_length, PAILLIER_ELEMENT_LENGTH);
982 memcpy (current, element_exported, PAILLIER_ELEMENT_LENGTH);
983 current += PAILLIER_ELEMENT_LENGTH;
985 GNUNET_free (element_exported);
986 for (i = session->transferred; i < session->transferred; i++) {
987 gcry_mpi_release (session->r_prime[i]);
988 gcry_mpi_release (session->r[i]);
990 session->transferred += todo_count;
991 session->msg = (struct GNUNET_MessageHeader *) msg;
992 session->service_transmit_handle =
993 GNUNET_MESH_notify_transmit_ready (session->tunnel,
995 GNUNET_TIME_UNIT_FOREVER_REL,
999 //disconnect our client
1000 if (NULL == session->service_transmit_handle) {
1001 GNUNET_log (GNUNET_ERROR_TYPE_ERROR, _ ("Could not send service-response message via mesh!)\n"));
1002 session->state = FINALIZED;
1004 session->response->client_notification_task =
1005 GNUNET_SCHEDULER_add_now (&prepare_client_end_notification,
1009 if (session->transferred != session->used)
1011 session->state = WAITING_FOR_MULTIPART_TRANSMISSION;
1014 session->state = FINALIZED;
1020 * generates the response message to be sent to alice after computing
1021 * the values (1), (2), S and S'
1022 * (1)[]: $E_A(a_{pi(i)}) times E_A(- r_{pi(i)} - b_{pi(i)}) &= E_A(a_{pi(i)} - r_{pi(i)} - b_{pi(i)})$
1023 * (2)[]: $E_A(a_{pi'(i)}) times E_A(- r_{pi'(i)}) &= E_A(a_{pi'(i)} - r_{pi'(i)})$
1024 * S: $S := E_A(sum (r_i + b_i)^2)$
1025 * S': $S' := E_A(sum r_i^2)$
1027 * @param s S: $S := E_A(sum (r_i + b_i)^2)$
1028 * @param s_prime S': $S' := E_A(sum r_i^2)$
1029 * @param session the associated requesting session with alice
1030 * @return #GNUNET_NO if we could not send our message
1031 * #GNUNET_OK if the operation succeeded
1034 prepare_service_response (gcry_mpi_t s,
1036 struct ServiceSession * session)
1038 struct GNUNET_SCALARPRODUCT_service_response * msg;
1039 uint32_t msg_length = 0;
1040 unsigned char * current = NULL;
1041 unsigned char * element_exported = NULL;
1042 size_t element_length = 0;
1045 msg_length = sizeof (struct GNUNET_SCALARPRODUCT_service_response)
1046 + 2 * PAILLIER_ELEMENT_LENGTH; // s, stick
1048 if (GNUNET_SERVER_MAX_MESSAGE_SIZE > msg_length + 2 * session->used * PAILLIER_ELEMENT_LENGTH) { //kp, kq
1049 msg_length += +2 * session->used * PAILLIER_ELEMENT_LENGTH;
1050 session->transferred = session->used;
1053 session->transferred = (GNUNET_SERVER_MAX_MESSAGE_SIZE - 1 - msg_length) / (PAILLIER_ELEMENT_LENGTH * 2);
1056 msg = GNUNET_malloc (msg_length);
1058 msg->header.type = htons (GNUNET_MESSAGE_TYPE_SCALARPRODUCT_BOB_TO_ALICE);
1059 msg->header.size = htons (msg_length);
1060 msg->total_element_count = htonl (session->total);
1061 msg->contained_element_count = htonl (session->used);
1062 msg->contained_element_count = htonl (session->transferred);
1063 memcpy (&msg->key, &session->key, sizeof (struct GNUNET_HashCode));
1064 current = (unsigned char *) &msg[1];
1066 element_exported = GNUNET_malloc (PAILLIER_ELEMENT_LENGTH);
1067 // 4 times the same logics with slight variations.
1068 // doesn't really justify having 2 functions for that
1069 // so i put it into blocks to enhance readability
1071 memset (element_exported, 0, PAILLIER_ELEMENT_LENGTH);
1072 GNUNET_assert (0 == gcry_mpi_print (GCRYMPI_FMT_USG,
1073 element_exported, PAILLIER_ELEMENT_LENGTH,
1076 adjust (element_exported, element_length, PAILLIER_ELEMENT_LENGTH);
1077 memcpy (current, element_exported, PAILLIER_ELEMENT_LENGTH);
1078 current += PAILLIER_ELEMENT_LENGTH;
1081 memset (element_exported, 0, PAILLIER_ELEMENT_LENGTH);
1082 GNUNET_assert (0 == gcry_mpi_print (GCRYMPI_FMT_USG,
1083 element_exported, PAILLIER_ELEMENT_LENGTH,
1086 adjust (element_exported, element_length, PAILLIER_ELEMENT_LENGTH);
1087 memcpy (current, element_exported, PAILLIER_ELEMENT_LENGTH);
1088 current += PAILLIER_ELEMENT_LENGTH;
1091 for (i = 0; i < session->transferred; i++) {
1093 memset (element_exported, 0, PAILLIER_ELEMENT_LENGTH);
1094 GNUNET_assert (0 == gcry_mpi_print (GCRYMPI_FMT_USG,
1095 element_exported, PAILLIER_ELEMENT_LENGTH,
1098 adjust (element_exported, element_length, PAILLIER_ELEMENT_LENGTH);
1099 memcpy (current, element_exported, PAILLIER_ELEMENT_LENGTH);
1100 current += PAILLIER_ELEMENT_LENGTH;
1102 memset (element_exported, 0, PAILLIER_ELEMENT_LENGTH);
1103 GNUNET_assert (0 == gcry_mpi_print (GCRYMPI_FMT_USG,
1104 element_exported, PAILLIER_ELEMENT_LENGTH,
1106 session->r_prime[i]));
1107 adjust (element_exported, element_length, PAILLIER_ELEMENT_LENGTH);
1108 memcpy (current, element_exported, PAILLIER_ELEMENT_LENGTH);
1109 current += PAILLIER_ELEMENT_LENGTH;
1112 GNUNET_free (element_exported);
1113 for (i = 0; i < session->transferred; i++) {
1114 gcry_mpi_release (session->r_prime[i]);
1115 gcry_mpi_release (session->r[i]);
1117 gcry_mpi_release (s);
1118 gcry_mpi_release (s_prime);
1120 session->msg = (struct GNUNET_MessageHeader *) msg;
1121 session->service_transmit_handle =
1122 GNUNET_MESH_notify_transmit_ready (session->tunnel,
1124 GNUNET_TIME_UNIT_FOREVER_REL,
1128 //disconnect our client
1129 if (NULL == session->service_transmit_handle) {
1130 GNUNET_log (GNUNET_ERROR_TYPE_ERROR, _ ("Could not send service-response message via mesh!)\n"));
1131 session->state = FINALIZED;
1133 session->response->client_notification_task =
1134 GNUNET_SCHEDULER_add_now (&prepare_client_end_notification,
1138 if (session->transferred != session->used)
1140 session->state = WAITING_FOR_MULTIPART_TRANSMISSION;
1143 session->state = FINALIZED;
1151 * compute the values
1152 * (1)[]: $E_A(a_{pi(i)}) otimes E_A(- r_{pi(i)} - b_{pi(i)}) &= E_A(a_{pi(i)} - r_{pi(i)} - b_{pi(i)})$
1153 * (2)[]: $E_A(a_{pi'(i)}) otimes E_A(- r_{pi'(i)}) &= E_A(a_{pi'(i)} - r_{pi'(i)})$
1154 * S: $S := E_A(sum (r_i + b_i)^2)$
1155 * S': $S' := E_A(sum r_i^2)$
1157 * @param request the requesting session + bob's requesting peer
1158 * @param response the responding session + bob's client handle
1159 * @return GNUNET_SYSERR if the computation failed
1160 * GNUNET_OK if everything went well.
1163 compute_service_response (struct ServiceSession * request,
1164 struct ServiceSession * response)
1168 int ret = GNUNET_SYSERR;
1172 gcry_mpi_t * rand = NULL;
1173 gcry_mpi_t * r = NULL;
1174 gcry_mpi_t * r_prime = NULL;
1177 gcry_mpi_t * a_pi_prime;
1179 gcry_mpi_t * rand_pi;
1180 gcry_mpi_t * rand_pi_prime;
1181 gcry_mpi_t s = NULL;
1182 gcry_mpi_t s_prime = NULL;
1183 gcry_mpi_t remote_n = NULL;
1184 gcry_mpi_t remote_nsquare;
1185 gcry_mpi_t remote_g = NULL;
1186 gcry_sexp_t tmp_exp;
1189 count = request->used;
1191 b = GNUNET_malloc (sizeof (gcry_mpi_t) * count);
1192 a_pi = GNUNET_malloc (sizeof (gcry_mpi_t) * count);
1193 b_pi = GNUNET_malloc (sizeof (gcry_mpi_t) * count);
1194 a_pi_prime = GNUNET_malloc (sizeof (gcry_mpi_t) * count);
1195 rand_pi = GNUNET_malloc (sizeof (gcry_mpi_t) * count);
1196 rand_pi_prime = GNUNET_malloc (sizeof (gcry_mpi_t) * count);
1198 // convert responder session to from long to mpi
1199 for (i = 0, j = 0; i < response->total && j < count; i++) {
1200 if (request->mask[i / 8] & (1 << (i % 8))) {
1201 value = response->vector[i] >= 0 ? response->vector[i] : -response->vector[i];
1202 // long to gcry_mpi_t
1203 if (0 > response->vector[i]) {
1204 b[j] = gcry_mpi_new (0);
1205 gcry_mpi_sub_ui (b[j], b[j], value);
1208 b[j] = gcry_mpi_set_ui (NULL, value);
1213 GNUNET_free (response->vector);
1214 response->vector = NULL;
1216 tmp_exp = gcry_sexp_find_token (request->remote_pubkey, "n", 0);
1218 GNUNET_break_op (0);
1219 gcry_sexp_release (request->remote_pubkey);
1220 request->remote_pubkey = NULL;
1223 remote_n = gcry_sexp_nth_mpi (tmp_exp, 1, GCRYMPI_FMT_USG);
1226 gcry_sexp_release (tmp_exp);
1229 remote_nsquare = gcry_mpi_new (KEYBITS + 1);
1230 gcry_mpi_mul (remote_nsquare, remote_n, remote_n);
1231 gcry_sexp_release (tmp_exp);
1232 tmp_exp = gcry_sexp_find_token (request->remote_pubkey, "g", 0);
1233 gcry_sexp_release (request->remote_pubkey);
1234 request->remote_pubkey = NULL;
1236 GNUNET_break_op (0);
1237 gcry_mpi_release (remote_n);
1240 remote_g = gcry_sexp_nth_mpi (tmp_exp, 1, GCRYMPI_FMT_USG);
1243 gcry_mpi_release (remote_n);
1244 gcry_sexp_release (tmp_exp);
1247 gcry_sexp_release (tmp_exp);
1249 // generate r, p and q
1250 rand = initialize_mpi_vector (count);
1251 for (i = 0; i < count; i++) {
1252 value = (int32_t) GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK, UINT32_MAX);
1254 // long to gcry_mpi_t
1256 gcry_mpi_sub_ui (rand[i],
1260 rand[i] = gcry_mpi_set_ui (rand[i], value);
1262 p = GNUNET_CRYPTO_random_permute (GNUNET_CRYPTO_QUALITY_WEAK, count);
1263 q = GNUNET_CRYPTO_random_permute (GNUNET_CRYPTO_QUALITY_WEAK, count);
1264 //initialize the result vectors
1265 r = initialize_mpi_vector (count);
1266 r_prime = initialize_mpi_vector (count);
1268 // copy the REFERNCES of a, b and r into aq and bq. we will not change
1269 // those values, thus we can work with the references
1270 memcpy (a_pi, request->a, sizeof (gcry_mpi_t) * count);
1271 memcpy (a_pi_prime, request->a, sizeof (gcry_mpi_t) * count);
1272 memcpy (b_pi, b, sizeof (gcry_mpi_t) * count);
1273 memcpy (rand_pi, rand, sizeof (gcry_mpi_t) * count);
1274 memcpy (rand_pi_prime, rand, sizeof (gcry_mpi_t) * count);
1276 // generate p and q permutations for a, b and r
1277 GNUNET_assert (permute_vector (a_pi, p, count));
1278 GNUNET_assert (permute_vector (b_pi, p, count));
1279 GNUNET_assert (permute_vector (rand_pi, p, count));
1280 GNUNET_assert (permute_vector (a_pi_prime, q, count));
1281 GNUNET_assert (permute_vector (rand_pi_prime, q, count));
1283 // encrypt the element
1284 // for the sake of readability I decided to have dedicated permutation
1285 // vectors, which get rid of all the lookups in p/q.
1286 // however, ap/aq are not absolutely necessary but are just abstraction
1287 // Calculate Kp = E(S + a_pi) (+) E(S - r_pi - b_pi)
1288 for (i = 0; i < count; i++) {
1289 // E(S - r_pi - b_pi)
1290 gcry_mpi_sub (r[i], my_offset, rand_pi[i]);
1291 gcry_mpi_sub (r[i], r[i], b_pi[i]);
1292 encrypt_element (r[i], r[i], remote_g, remote_n, remote_nsquare);
1294 // E(S - r_pi - b_pi) * E(S + a_pi) == E(2*S + a - r - b)
1295 gcry_mpi_mulm (r[i], r[i], a_pi[i], remote_nsquare);
1299 GNUNET_free (rand_pi);
1301 // Calculate Kq = E(S + a_qi) (+) E(S - r_qi)
1302 for (i = 0; i < count; i++) {
1304 gcry_mpi_sub (r_prime[i], my_offset, rand_pi_prime[i]);
1305 encrypt_element (r_prime[i], r_prime[i], remote_g, remote_n, remote_nsquare);
1307 // E(S - r_qi) * E(S + a_qi) == E(2*S + a_qi - r_qi)
1308 gcry_mpi_mulm (r_prime[i], r_prime[i], a_pi_prime[i], remote_nsquare);
1310 GNUNET_free (a_pi_prime);
1311 GNUNET_free (rand_pi_prime);
1314 request->r_prime = r_prime;
1315 request->response = response;
1317 // Calculate S' = E(SUM( r_i^2 ))
1318 s_prime = compute_square_sum (rand, count);
1319 encrypt_element (s_prime, s_prime, remote_g, remote_n, remote_nsquare);
1321 // Calculate S = E(SUM( (r_i + b_i)^2 ))
1322 for (i = 0; i < count; i++) {
1323 gcry_mpi_add (rand[i], rand[i], b[i]);
1325 s = compute_square_sum (rand, count);
1326 encrypt_element (s, s, remote_g, remote_n, remote_nsquare);
1327 gcry_mpi_release (remote_n);
1328 gcry_mpi_release (remote_g);
1329 gcry_mpi_release (remote_nsquare);
1331 // release r and tmp
1332 for (i = 0; i < count; i++)
1333 // rp, rq, aq, ap, bp, bq are released along with a, r, b respectively, (a and b are handled at except:)
1334 gcry_mpi_release (rand[i]);
1336 // copy the r[], r_prime[], S and Stick into a new message, prepare_service_response frees these
1337 if (GNUNET_YES != prepare_service_response (s, s_prime, request))
1338 GNUNET_log (GNUNET_ERROR_TYPE_INFO, _ ("Failed to communicate with `%s', scalar product calculation aborted.\n"),
1339 GNUNET_i2s (&request->peer));
1344 for (i = 0; i < count; i++) {
1345 gcry_mpi_release (b[i]);
1346 gcry_mpi_release (request->a[i]);
1350 GNUNET_free (request->a);
1358 * Send a multi part chunk of a service request from alice to bob.
1359 * This element only contains a part of the elements-vector (session->a[]),
1360 * mask and public key set have to be contained within the first message
1362 * This allows a ~32kbit key length while using 32000 elements or 62000 elements per request.
1364 * @param cls the associated service session
1367 prepare_service_request_multipart (void *cls)
1369 struct ServiceSession * session = cls;
1370 unsigned char * current;
1371 unsigned char * element_exported;
1372 struct GNUNET_SCALARPRODUCT_multipart_message * msg;
1375 uint32_t msg_length;
1376 uint32_t todo_count;
1377 size_t element_length = 0; // initialized by gcry_mpi_print, but the compiler doesn't know that
1381 msg_length = sizeof (struct GNUNET_SCALARPRODUCT_multipart_message);
1382 todo_count = session->used - session->transferred;
1384 if (todo_count > MULTIPART_ELEMENT_CAPACITY)
1385 // send the currently possible maximum chunk
1386 todo_count = MULTIPART_ELEMENT_CAPACITY;
1388 msg_length += todo_count * PAILLIER_ELEMENT_LENGTH;
1389 msg = GNUNET_malloc (msg_length);
1390 msg->header.type = htons (GNUNET_MESSAGE_TYPE_SCALARPRODUCT_ALICE_TO_BOB_MULTIPART);
1391 msg->header.size = htons (msg_length);
1392 msg->multipart_element_count = htonl (todo_count);
1394 element_exported = GNUNET_malloc (PAILLIER_ELEMENT_LENGTH);
1395 a = gcry_mpi_new (KEYBITS * 2);
1396 current = (unsigned char *) &msg[1];
1397 // encrypt our vector and generate string representations
1398 for (i = session->last_processed, j = 0; i < session->total; i++) {
1399 // is this a used element?
1400 if (session->mask[i / 8] & 1 << (i % 8)) {
1401 if (todo_count <= j)
1402 break; //reached end of this message, can't include more
1404 memset (element_exported, 0, PAILLIER_ELEMENT_LENGTH);
1405 value = session->vector[i] >= 0 ? session->vector[i] : -session->vector[i];
1407 a = gcry_mpi_set_ui (a, 0);
1408 // long to gcry_mpi_t
1409 if (session->vector[i] < 0)
1410 gcry_mpi_sub_ui (a, a, value);
1412 gcry_mpi_add_ui (a, a, value);
1414 session->a[session->transferred + j++] = gcry_mpi_set (NULL, a);
1415 gcry_mpi_add (a, a, my_offset);
1416 encrypt_element (a, a, my_g, my_n, my_nsquare);
1418 // get representation as string
1419 // we always supply some value, so gcry_mpi_print fails only if it can't reserve memory
1420 GNUNET_assert (!gcry_mpi_print (GCRYMPI_FMT_USG,
1421 element_exported, PAILLIER_ELEMENT_LENGTH,
1425 // move buffer content to the end of the buffer so it can easily be read by libgcrypt. also this now has fixed size
1426 adjust (element_exported, element_length, PAILLIER_ELEMENT_LENGTH);
1428 // copy over to the message
1429 memcpy (current, element_exported, PAILLIER_ELEMENT_LENGTH);
1430 current += PAILLIER_ELEMENT_LENGTH;
1433 gcry_mpi_release (a);
1434 GNUNET_free (element_exported);
1435 session->transferred += todo_count;
1437 session->msg = (struct GNUNET_MessageHeader *) msg;
1438 GNUNET_log (GNUNET_ERROR_TYPE_INFO, _ ("Transmitting service request.\n"));
1440 //transmit via mesh messaging
1441 session->service_transmit_handle = GNUNET_MESH_notify_transmit_ready (session->tunnel, GNUNET_YES,
1442 GNUNET_TIME_UNIT_FOREVER_REL,
1446 if (!session->service_transmit_handle) {
1447 GNUNET_log (GNUNET_ERROR_TYPE_ERROR, _ ("Could not send service-request multipart message to tunnel!\n"));
1449 session->msg = NULL;
1450 session->client_notification_task =
1451 GNUNET_SCHEDULER_add_now (&prepare_client_end_notification,
1455 if (session->transferred != session->used) {
1456 session->last_processed = i;
1460 session->state = WAITING_FOR_SERVICE_RESPONSE;
1465 * Executed by Alice, fills in a service-request message and sends it to the given peer
1467 * @param cls the session associated with this request
1468 * @param tc task context handed over by scheduler, unsued
1471 prepare_service_request (void *cls,
1472 const struct GNUNET_SCHEDULER_TaskContext *tc)
1474 struct ServiceSession * session = cls;
1475 unsigned char * current;
1476 unsigned char * element_exported;
1477 struct GNUNET_SCALARPRODUCT_service_request * msg;
1480 uint32_t msg_length;
1481 size_t element_length = 0; // initialized by gcry_mpi_print, but the compiler doesn't know that
1485 session->service_request_task = GNUNET_SCHEDULER_NO_TASK;
1487 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, _ ("Successfully created new tunnel to peer (%s)!\n"), GNUNET_i2s (&session->peer));
1489 msg_length = sizeof (struct GNUNET_SCALARPRODUCT_service_request)
1490 +session->mask_length
1491 + my_pubkey_external_length;
1493 if (GNUNET_SERVER_MAX_MESSAGE_SIZE > msg_length + session->used * PAILLIER_ELEMENT_LENGTH) {
1494 msg_length += session->used * PAILLIER_ELEMENT_LENGTH;
1495 session->transferred = session->used;
1498 //create a multipart msg, first we calculate a new msg size for the head msg
1499 session->transferred = (GNUNET_SERVER_MAX_MESSAGE_SIZE - 1 - msg_length) / PAILLIER_ELEMENT_LENGTH;
1502 msg = GNUNET_malloc (msg_length);
1503 msg->header.type = htons (GNUNET_MESSAGE_TYPE_SCALARPRODUCT_ALICE_TO_BOB);
1504 msg->total_element_count = htonl (session->used);
1505 msg->contained_element_count = htonl (session->transferred);
1506 memcpy (&msg->key, &session->key, sizeof (struct GNUNET_HashCode));
1507 msg->mask_length = htonl (session->mask_length);
1508 msg->pk_length = htonl (my_pubkey_external_length);
1509 msg->element_count = htonl (session->total);
1510 msg->header.size = htons (msg_length);
1512 // fill in the payload
1513 current = (unsigned char *) &msg[1];
1514 // copy over the mask
1515 memcpy (current, session->mask, session->mask_length);
1516 // copy over our public key
1517 current += session->mask_length;
1518 memcpy (current, my_pubkey_external, my_pubkey_external_length);
1519 current += my_pubkey_external_length;
1521 // now copy over the element vector
1522 element_exported = GNUNET_malloc (PAILLIER_ELEMENT_LENGTH);
1523 session->a = GNUNET_malloc (sizeof (gcry_mpi_t) * session->used);
1524 a = gcry_mpi_new (KEYBITS * 2);
1525 // encrypt our vector and generate string representations
1526 for (i = 0, j = 0; i < session->total; i++) {
1527 // if this is a used element...
1528 if (session->mask[i / 8] & 1 << (i % 8)) {
1529 if (session->transferred <= j)
1530 break; //reached end of this message, can't include more
1532 memset (element_exported, 0, PAILLIER_ELEMENT_LENGTH);
1533 value = session->vector[i] >= 0 ? session->vector[i] : -session->vector[i];
1535 a = gcry_mpi_set_ui (a, 0);
1536 // long to gcry_mpi_t
1537 if (session->vector[i] < 0)
1538 gcry_mpi_sub_ui (a, a, value);
1540 gcry_mpi_add_ui (a, a, value);
1542 session->a[j++] = gcry_mpi_set (NULL, a);
1543 gcry_mpi_add (a, a, my_offset);
1544 encrypt_element (a, a, my_g, my_n, my_nsquare);
1546 // get representation as string
1547 // we always supply some value, so gcry_mpi_print fails only if it can't reserve memory
1548 GNUNET_assert (!gcry_mpi_print (GCRYMPI_FMT_USG,
1549 element_exported, PAILLIER_ELEMENT_LENGTH,
1553 // move buffer content to the end of the buffer so it can easily be read by libgcrypt. also this now has fixed size
1554 adjust (element_exported, element_length, PAILLIER_ELEMENT_LENGTH);
1556 // copy over to the message
1557 memcpy (current, element_exported, PAILLIER_ELEMENT_LENGTH);
1558 current += PAILLIER_ELEMENT_LENGTH;
1561 gcry_mpi_release (a);
1562 GNUNET_free (element_exported);
1564 session->msg = (struct GNUNET_MessageHeader *) msg;
1565 GNUNET_log (GNUNET_ERROR_TYPE_INFO, _ ("Transmitting service request.\n"));
1567 //transmit via mesh messaging
1568 session->service_transmit_handle = GNUNET_MESH_notify_transmit_ready (session->tunnel, GNUNET_YES,
1569 GNUNET_TIME_UNIT_FOREVER_REL,
1573 if (!session->service_transmit_handle) {
1574 GNUNET_log (GNUNET_ERROR_TYPE_ERROR, _ ("Could not send message to tunnel!\n"));
1576 session->msg = NULL;
1577 session->client_notification_task =
1578 GNUNET_SCHEDULER_add_now (&prepare_client_end_notification,
1582 if (session->transferred != session->used) {
1583 session->state = WAITING_FOR_MULTIPART_TRANSMISSION;
1584 session->last_processed = i;
1587 //singlepart message
1588 session->state = WAITING_FOR_SERVICE_RESPONSE;
1593 * Handler for a client request message.
1594 * Can either be type A or B
1595 * A: request-initiation to compute a scalar product with a peer
1596 * B: response role, keep the values + session and wait for a matching session or process a waiting request
1598 * @param cls closure
1599 * @param client identification of the client
1600 * @param message the actual message
1603 handle_client_request (void *cls,
1604 struct GNUNET_SERVER_Client *client,
1605 const struct GNUNET_MessageHeader *message)
1607 const struct GNUNET_SCALARPRODUCT_client_request * msg = (const struct GNUNET_SCALARPRODUCT_client_request *) message;
1608 struct ServiceSession * session;
1609 uint32_t element_count;
1610 uint32_t mask_length;
1615 // only one concurrent session per client connection allowed, simplifies logics a lot...
1616 session = GNUNET_SERVER_client_get_user_context (client, struct ServiceSession);
1617 if ((NULL != session) && (session->state != FINALIZED)) {
1618 GNUNET_SERVER_receive_done (client, GNUNET_OK);
1621 else if (NULL != session) {
1622 // old session is already completed, clean it up
1623 GNUNET_CONTAINER_DLL_remove (from_client_head, from_client_tail, session);
1624 free_session_variables (session);
1625 GNUNET_free (session);
1628 //we need at least a peer and one message id to compare
1629 if (sizeof (struct GNUNET_SCALARPRODUCT_client_request) > ntohs (msg->header.size)) {
1630 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
1631 _ ("Too short message received from client!\n"));
1632 GNUNET_SERVER_receive_done (client, GNUNET_SYSERR);
1636 msg_type = ntohs (msg->header.type);
1637 element_count = ntohl (msg->element_count);
1638 mask_length = ntohl (msg->mask_length);
1640 //sanity check: is the message as long as the message_count fields suggests?
1641 if ((ntohs (msg->header.size) != (sizeof (struct GNUNET_SCALARPRODUCT_client_request) +element_count * sizeof (int32_t) + mask_length))
1642 || (0 == element_count)) {
1643 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
1644 _ ("Invalid message received from client, session information incorrect!\n"));
1645 GNUNET_SERVER_receive_done (client, GNUNET_SYSERR);
1649 // do we have a duplicate session here already?
1650 if (NULL != find_matching_session (from_client_tail,
1654 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
1655 _ ("Duplicate session information received, cannot create new session with key `%s'\n"),
1656 GNUNET_h2s (&msg->key));
1657 GNUNET_SERVER_receive_done (client, GNUNET_SYSERR);
1661 session = GNUNET_new (struct ServiceSession);
1662 session->service_request_task = GNUNET_SCHEDULER_NO_TASK;
1663 session->client_notification_task = GNUNET_SCHEDULER_NO_TASK;
1664 session->client = client;
1665 session->total = element_count;
1666 session->mask_length = mask_length;
1667 // get our transaction key
1668 memcpy (&session->key, &msg->key, sizeof (struct GNUNET_HashCode));
1669 //allocate memory for vector and encrypted vector
1670 session->vector = GNUNET_malloc (sizeof (int32_t) * element_count);
1671 vector = (int32_t *) & msg[1];
1673 if (GNUNET_MESSAGE_TYPE_SCALARPRODUCT_CLIENT_TO_ALICE == msg_type) {
1674 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1675 _ ("Got client-request-session with key %s, preparing tunnel to remote service.\n"),
1676 GNUNET_h2s (&session->key));
1678 session->role = ALICE;
1680 session->mask = GNUNET_malloc (mask_length);
1681 memcpy (session->mask, &vector[element_count], mask_length);
1683 // copy over the elements
1685 for (i = 0; i < element_count; i++) {
1686 session->vector[i] = ntohl (vector[i]);
1687 if (session->vector[i] == 0)
1688 session->mask[i / 8] &= ~(1 << (i % 8));
1689 if (session->mask[i / 8] & (1 << (i % 8)))
1693 if (0 == session->used) {
1694 GNUNET_break_op (0);
1695 GNUNET_free (session->vector);
1696 GNUNET_free (session);
1697 GNUNET_SERVER_receive_done (client, GNUNET_SYSERR);
1700 //session with ourself makes no sense!
1701 if (!memcmp (&msg->peer, &me, sizeof (struct GNUNET_PeerIdentity))) {
1703 GNUNET_free (session->vector);
1704 GNUNET_free (session);
1705 GNUNET_SERVER_receive_done (client, GNUNET_SYSERR);
1709 memcpy (&session->peer, &msg->peer, sizeof (struct GNUNET_PeerIdentity));
1710 GNUNET_log (GNUNET_ERROR_TYPE_INFO,
1711 _ ("Creating new tunnel for session with key %s.\n"),
1712 GNUNET_h2s (&session->key));
1713 session->tunnel = GNUNET_MESH_tunnel_create (my_mesh, session,
1715 GNUNET_APPLICATION_TYPE_SCALARPRODUCT,
1718 //prepare_service_request, tunnel_peer_disconnect_handler,
1719 if (!session->tunnel) {
1721 GNUNET_free (session->vector);
1722 GNUNET_free (session);
1723 GNUNET_SERVER_receive_done (client, GNUNET_SYSERR);
1726 GNUNET_SERVER_client_set_user_context (client, session);
1727 GNUNET_CONTAINER_DLL_insert (from_client_head, from_client_tail, session);
1729 session->state = CLIENT_REQUEST_RECEIVED;
1730 session->service_request_task =
1731 GNUNET_SCHEDULER_add_now (&prepare_service_request,
1736 struct ServiceSession * requesting_session;
1737 enum SessionState needed_state = SERVICE_REQUEST_RECEIVED;
1739 session->role = BOB;
1740 session->mask = NULL;
1741 // copy over the elements
1742 session->used = element_count;
1743 for (i = 0; i < element_count; i++)
1744 session->vector[i] = ntohl (vector[i]);
1745 session->state = CLIENT_RESPONSE_RECEIVED;
1747 GNUNET_SERVER_client_set_user_context (client, session);
1748 GNUNET_CONTAINER_DLL_insert (from_client_head, from_client_tail, session);
1750 //check if service queue contains a matching request
1751 requesting_session = find_matching_session (from_service_tail,
1754 &needed_state, NULL);
1755 if (NULL != requesting_session) {
1756 GNUNET_log (GNUNET_ERROR_TYPE_INFO, _ ("Got client-responder-session with key %s and a matching service-request-session set, processing.\n"), GNUNET_h2s (&session->key));
1757 if (GNUNET_OK != compute_service_response (requesting_session, session))
1758 session->client_notification_task =
1759 GNUNET_SCHEDULER_add_now (&prepare_client_end_notification,
1764 GNUNET_log (GNUNET_ERROR_TYPE_INFO, _ ("Got client-responder-session with key %s but NO matching service-request-session set, queuing element for later use.\n"), GNUNET_h2s (&session->key));
1765 // no matching session exists yet, store the response
1766 // for later processing by handle_service_request()
1769 GNUNET_SERVER_receive_done (client, GNUNET_YES);
1774 * Function called for inbound tunnels.
1776 * @param cls closure
1777 * @param tunnel new handle to the tunnel
1778 * @param initiator peer that started the tunnel
1779 * @param port unused
1780 * @return session associated with the tunnel
1783 tunnel_incoming_handler (void *cls,
1784 struct GNUNET_MESH_Tunnel *tunnel,
1785 const struct GNUNET_PeerIdentity *initiator,
1788 struct ServiceSession * c = GNUNET_new (struct ServiceSession);
1790 c->peer = *initiator;
1793 c->state = WAITING_FOR_SERVICE_REQUEST;
1799 * Function called whenever a tunnel is destroyed. Should clean up
1800 * any associated state.
1802 * It must NOT call GNUNET_MESH_tunnel_destroy on the tunnel.
1804 * @param cls closure (set from GNUNET_MESH_connect)
1805 * @param tunnel connection to the other end (henceforth invalid)
1806 * @param tunnel_ctx place where local state associated
1807 * with the tunnel is stored
1810 tunnel_destruction_handler (void *cls,
1811 const struct GNUNET_MESH_Tunnel *tunnel,
1814 struct ServiceSession * session = tunnel_ctx;
1815 struct ServiceSession * client_session;
1816 struct ServiceSession * curr;
1818 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1819 _ ("Peer disconnected, terminating session %s with peer (%s)\n"),
1820 GNUNET_h2s (&session->key),
1821 GNUNET_i2s (&session->peer));
1822 if (ALICE == session->role) {
1823 // as we have only one peer connected in each session, just remove the session
1825 if ((SERVICE_RESPONSE_RECEIVED > session->state) && (!do_shutdown)) {
1826 session->tunnel = NULL;
1827 // if this happened before we received the answer, we must terminate the session
1828 session->client_notification_task =
1829 GNUNET_SCHEDULER_add_now (&prepare_client_end_notification,
1833 else { //(BOB == session->role) service session
1834 // remove the session, unless it has already been dequeued, but somehow still active
1835 // this could bug without the IF in case the queue is empty and the service session was the only one know to the service
1836 // scenario: disconnect before alice can send her message to bob.
1837 for (curr = from_service_head; NULL != curr; curr = curr->next)
1838 if (curr == session) {
1839 GNUNET_CONTAINER_DLL_remove (from_service_head, from_service_tail, curr);
1842 // there is a client waiting for this service session, terminate it, too!
1843 // i assume the tupel of key and element count is unique. if it was not the rest of the code would not work either.
1844 client_session = find_matching_session (from_client_tail,
1848 free_session_variables (session);
1849 GNUNET_free (session);
1851 // the client has to check if it was waiting for a result
1852 // or if it was a responder, no point in adding more statefulness
1853 if (client_session && (!do_shutdown)) {
1854 client_session->state = FINALIZED;
1855 client_session->client_notification_task =
1856 GNUNET_SCHEDULER_add_now (&prepare_client_end_notification,
1864 * Compute our scalar product, done by Alice
1866 * @param session - the session associated with this computation
1867 * @return product as MPI, never NULL
1870 compute_scalar_product (struct ServiceSession * session)
1881 count = session->used;
1882 tmp = gcry_mpi_new (KEYBITS);
1883 // due to the introduced static offset S, we now also have to remove this
1884 // from the E(a_pi)(+)E(-b_pi-r_pi) and E(a_qi)(+)E(-r_qi) twice each,
1885 // the result is E((S + a_pi) + (S -b_pi-r_pi)) and E(S + a_qi + S - r_qi)
1886 for (i = 0; i < count; i++) {
1887 decrypt_element (session->r[i], session->r[i], my_mu, my_lambda, my_n, my_nsquare);
1888 gcry_mpi_sub (session->r[i], session->r[i], my_offset);
1889 gcry_mpi_sub (session->r[i], session->r[i], my_offset);
1890 decrypt_element (session->r_prime[i], session->r_prime[i], my_mu, my_lambda, my_n, my_nsquare);
1891 gcry_mpi_sub (session->r_prime[i], session->r_prime[i], my_offset);
1892 gcry_mpi_sub (session->r_prime[i], session->r_prime[i], my_offset);
1895 // calculate t = sum(ai)
1896 t = compute_square_sum (session->a, count);
1899 u = gcry_mpi_new (0);
1900 tmp = compute_square_sum (session->r, count);
1901 gcry_mpi_sub (u, u, tmp);
1902 gcry_mpi_release (tmp);
1905 u_prime = gcry_mpi_new (0);
1906 tmp = compute_square_sum (session->r_prime, count);
1907 gcry_mpi_sub (u_prime, u_prime, tmp);
1909 GNUNET_assert (p = gcry_mpi_new (0));
1910 GNUNET_assert (p_prime = gcry_mpi_new (0));
1913 decrypt_element (session->s, session->s, my_mu, my_lambda, my_n, my_nsquare);
1914 decrypt_element (session->s_prime, session->s_prime, my_mu, my_lambda, my_n, my_nsquare);
1917 gcry_mpi_add (p, session->s, t);
1918 gcry_mpi_add (p, p, u);
1921 gcry_mpi_add (p_prime, session->s_prime, t);
1922 gcry_mpi_add (p_prime, p_prime, u_prime);
1924 gcry_mpi_release (t);
1925 gcry_mpi_release (u);
1926 gcry_mpi_release (u_prime);
1929 gcry_mpi_sub (p, p, p_prime);
1930 gcry_mpi_release (p_prime);
1931 tmp = gcry_mpi_set_ui (tmp, 2);
1932 gcry_mpi_div (p, NULL, p, tmp, 0);
1934 gcry_mpi_release (tmp);
1935 for (i = 0; i < count; i++)
1936 gcry_mpi_release (session->a[i]);
1937 GNUNET_free (session->a);
1945 * Handle a multipart-chunk of a request from another service to calculate a scalarproduct with us.
1947 * @param cls closure (set from #GNUNET_MESH_connect)
1948 * @param tunnel connection to the other end
1949 * @param tunnel_ctx place to store local state associated with the tunnel
1950 * @param message the actual message
1951 * @return #GNUNET_OK to keep the connection open,
1952 * #GNUNET_SYSERR to close it (signal serious error)
1955 handle_service_request_multipart (void *cls,
1956 struct GNUNET_MESH_Tunnel * tunnel,
1958 const struct GNUNET_MessageHeader * message)
1960 struct ServiceSession * session;
1961 const struct GNUNET_SCALARPRODUCT_multipart_message * msg = (const struct GNUNET_SCALARPRODUCT_multipart_message *) message;
1962 uint32_t used_elements;
1963 uint32_t contained_elements = 0;
1964 uint32_t msg_length;
1965 unsigned char * current;
1969 // are we in the correct state?
1970 session = (struct ServiceSession *) * tunnel_ctx;
1971 if ((BOB != session->role) || (WAITING_FOR_MULTIPART_TRANSMISSION != session->state)) {
1974 // shorter than minimum?
1975 if (ntohs (msg->header.size) <= sizeof (struct GNUNET_SCALARPRODUCT_multipart_message)) {
1978 used_elements = session->used;
1979 contained_elements = ntohl (msg->multipart_element_count);
1980 msg_length = sizeof (struct GNUNET_SCALARPRODUCT_multipart_message)
1981 +contained_elements * PAILLIER_ELEMENT_LENGTH;
1983 if ((ntohs (msg->header.size) != msg_length)
1984 || (used_elements < contained_elements + session->transferred)) {
1987 current = (unsigned char *) &msg[1];
1988 if (contained_elements != 0) {
1989 // Convert each vector element to MPI_value
1990 for (i = session->transferred; i < session->transferred + contained_elements; i++) {
1992 if (0 != (rc = gcry_mpi_scan (&session->a[i],
1994 ¤t[i * PAILLIER_ELEMENT_LENGTH],
1995 PAILLIER_ELEMENT_LENGTH,
1997 LOG_GCRY (GNUNET_ERROR_TYPE_DEBUG, "gcry_mpi_scan", rc);
2001 session->transferred += contained_elements;
2003 if (session->transferred == used_elements) {
2004 // single part finished
2005 session->state = SERVICE_REQUEST_RECEIVED;
2006 if (session->response) {
2007 GNUNET_log (GNUNET_ERROR_TYPE_INFO, _ ("Got session with key %s and a matching element set, processing.\n"), GNUNET_h2s (&session->key));
2008 if (GNUNET_OK != compute_service_response (session, session->response)) {
2009 //something went wrong, remove it again...
2014 GNUNET_log (GNUNET_ERROR_TYPE_INFO, _ ("Got session with key %s without a matching element set, queueing.\n"), GNUNET_h2s (&session->key));
2017 // multipart message
2023 // and notify our client-session that we could not complete the session
2024 GNUNET_CONTAINER_DLL_remove (from_service_head, from_service_tail, session);
2025 if (session->response)
2026 // we just found the responder session in this queue
2027 session->response->client_notification_task =
2028 GNUNET_SCHEDULER_add_now (&prepare_client_end_notification,
2030 free_session_variables (session);
2031 GNUNET_free (session);
2032 return GNUNET_SYSERR;
2037 * Handle a request from another service to calculate a scalarproduct with us.
2039 * @param cls closure (set from #GNUNET_MESH_connect)
2040 * @param tunnel connection to the other end
2041 * @param tunnel_ctx place to store local state associated with the tunnel
2042 * @param message the actual message
2043 * @return #GNUNET_OK to keep the connection open,
2044 * #GNUNET_SYSERR to close it (signal serious error)
2047 handle_service_request (void *cls,
2048 struct GNUNET_MESH_Tunnel * tunnel,
2050 const struct GNUNET_MessageHeader * message)
2052 struct ServiceSession * session;
2053 const struct GNUNET_SCALARPRODUCT_service_request * msg = (const struct GNUNET_SCALARPRODUCT_service_request *) message;
2054 uint32_t mask_length;
2056 uint32_t used_elements;
2057 uint32_t contained_elements = 0;
2058 uint32_t element_count;
2059 uint32_t msg_length;
2060 unsigned char * current;
2063 enum SessionState needed_state;
2065 session = (struct ServiceSession *) * tunnel_ctx;
2066 if (WAITING_FOR_SERVICE_REQUEST != session->state) {
2069 // Check if message was sent by me, which would be bad!
2070 if (!memcmp (&session->peer, &me, sizeof (struct GNUNET_PeerIdentity))) {
2071 GNUNET_free (session);
2073 return GNUNET_SYSERR;
2075 // shorter than expected?
2076 if (ntohs (msg->header.size) < sizeof (struct GNUNET_SCALARPRODUCT_service_request)) {
2077 GNUNET_free (session);
2078 GNUNET_break_op (0);
2079 return GNUNET_SYSERR;
2081 mask_length = ntohl (msg->mask_length);
2082 pk_length = ntohl (msg->pk_length);
2083 used_elements = ntohl (msg->total_element_count);
2084 contained_elements = ntohl (msg->contained_element_count);
2085 element_count = ntohl (msg->element_count);
2086 msg_length = sizeof (struct GNUNET_SCALARPRODUCT_service_request)
2087 +mask_length + pk_length + contained_elements * PAILLIER_ELEMENT_LENGTH;
2089 //sanity check: is the message as long as the message_count fields suggests?
2090 if ((ntohs (msg->header.size) != msg_length) || (element_count < used_elements) || (used_elements < contained_elements)
2091 || (used_elements == 0) || (mask_length != (element_count / 8 + (element_count % 8 ? 1 : 0)))
2093 GNUNET_free (session);
2094 GNUNET_break_op (0);
2095 return GNUNET_SYSERR;
2097 if (find_matching_session (from_service_tail,
2102 GNUNET_log (GNUNET_ERROR_TYPE_ERROR, _ ("Got message with duplicate session key (`%s'), ignoring service request.\n"), (const char *) &(msg->key));
2103 GNUNET_free (session);
2104 return GNUNET_SYSERR;
2107 memcpy (&session->peer, &session->peer, sizeof (struct GNUNET_PeerIdentity));
2108 session->total = element_count;
2109 session->used = used_elements;
2110 session->transferred = contained_elements;
2111 session->tunnel = tunnel;
2114 memcpy (&session->key, &msg->key, sizeof (struct GNUNET_HashCode));
2115 current = (unsigned char *) &msg[1];
2116 //preserve the mask, we will need that later on
2117 session->mask = GNUNET_malloc (mask_length);
2118 memcpy (session->mask, current, mask_length);
2120 current += mask_length;
2122 //convert the publickey to sexp
2123 if (0 != (rc = gcry_sexp_new (&session->remote_pubkey, current, pk_length, 1))) {
2124 LOG_GCRY (GNUNET_ERROR_TYPE_DEBUG, "gcry_sexp_new", rc);
2125 GNUNET_free (session->mask);
2126 GNUNET_free (session);
2127 return GNUNET_SYSERR;
2129 current += pk_length;
2130 //check if service queue contains a matching request
2131 needed_state = CLIENT_RESPONSE_RECEIVED;
2132 session->response = find_matching_session (from_client_tail,
2135 &needed_state, NULL);
2137 session->a = GNUNET_malloc (sizeof (gcry_mpi_t) * used_elements);
2138 session->state = WAITING_FOR_MULTIPART_TRANSMISSION;
2139 GNUNET_CONTAINER_DLL_insert (from_service_head, from_service_tail, session);
2140 if (contained_elements != 0) {
2141 // Convert each vector element to MPI_value
2142 for (i = 0; i < contained_elements; i++) {
2144 if (0 != (rc = gcry_mpi_scan (&session->a[i],
2146 ¤t[i * PAILLIER_ELEMENT_LENGTH],
2147 PAILLIER_ELEMENT_LENGTH,
2149 LOG_GCRY (GNUNET_ERROR_TYPE_DEBUG, "gcry_mpi_scan", rc);
2153 if (contained_elements == used_elements) {
2154 // single part finished
2155 session->state = SERVICE_REQUEST_RECEIVED;
2156 if (session->response) {
2157 GNUNET_log (GNUNET_ERROR_TYPE_INFO, _ ("Got session with key %s and a matching element set, processing.\n"), GNUNET_h2s (&session->key));
2158 if (GNUNET_OK != compute_service_response (session, session->response)) {
2159 //something went wrong, remove it again...
2164 GNUNET_log (GNUNET_ERROR_TYPE_INFO, _ ("Got session with key %s without a matching element set, queueing.\n"), GNUNET_h2s (&session->key));
2167 // multipart message
2172 GNUNET_break_op (0);
2173 if ((NULL != session->next) || (NULL != session->prev) || (from_service_head == session))
2174 GNUNET_CONTAINER_DLL_remove (from_service_head, from_service_tail, session);
2175 // and notify our client-session that we could not complete the session
2176 if (session->response)
2177 // we just found the responder session in this queue
2178 session->response->client_notification_task =
2179 GNUNET_SCHEDULER_add_now (&prepare_client_end_notification,
2181 free_session_variables (session);
2182 return GNUNET_SYSERR;
2187 * Handle a multipart chunk of a response we got from another service we wanted to calculate a scalarproduct with.
2189 * @param cls closure (set from #GNUNET_MESH_connect)
2190 * @param tunnel connection to the other end
2191 * @param tunnel_ctx place to store local state associated with the tunnel
2192 * @param message the actual message
2193 * @return #GNUNET_OK to keep the connection open,
2194 * #GNUNET_SYSERR to close it (signal serious error)
2197 handle_service_response_multipart (void *cls,
2198 struct GNUNET_MESH_Tunnel * tunnel,
2200 const struct GNUNET_MessageHeader * message)
2202 struct ServiceSession * session;
2203 const struct GNUNET_SCALARPRODUCT_multipart_message * msg = (const struct GNUNET_SCALARPRODUCT_multipart_message *) message;
2204 unsigned char * current;
2207 uint32_t contained = 0;
2211 GNUNET_assert (NULL != message);
2212 // are we in the correct state?
2213 session = (struct ServiceSession *) * tunnel_ctx;
2214 if ((ALICE != session->role) || (WAITING_FOR_MULTIPART_TRANSMISSION != session->state)) {
2217 // shorter than minimum?
2218 if (ntohs (msg->header.size) <= sizeof (struct GNUNET_SCALARPRODUCT_multipart_message)) {
2221 contained = ntohl (msg->multipart_element_count);
2222 msg_size = sizeof (struct GNUNET_SCALARPRODUCT_multipart_message)
2223 + 2 * contained * PAILLIER_ELEMENT_LENGTH;
2224 //sanity check: is the message as long as the message_count fields suggests?
2225 if ((ntohs (msg->header.size) != msg_size) || (session->used < contained)) {
2228 current = (unsigned char *) &msg[1];
2229 // Convert each k[][perm] to its MPI_value
2230 for (i = 0; i < contained; i++) {
2231 if (0 != (rc = gcry_mpi_scan (&session->r[i], GCRYMPI_FMT_USG, current,
2232 PAILLIER_ELEMENT_LENGTH, &read))) {
2233 LOG_GCRY (GNUNET_ERROR_TYPE_DEBUG, "gcry_mpi_scan", rc);
2236 current += PAILLIER_ELEMENT_LENGTH;
2237 if (0 != (rc = gcry_mpi_scan (&session->r_prime[i], GCRYMPI_FMT_USG, current,
2238 PAILLIER_ELEMENT_LENGTH, &read))) {
2239 LOG_GCRY (GNUNET_ERROR_TYPE_DEBUG, "gcry_mpi_scan", rc);
2242 current += PAILLIER_ELEMENT_LENGTH;
2244 session->transferred += contained;
2245 if (session->transferred != session->used)
2247 session->state = SERVICE_RESPONSE_RECEIVED;
2248 session->product = compute_scalar_product (session);
2249 return GNUNET_SYSERR; // terminate the tunnel right away, we are done here!
2252 GNUNET_break_op (0);
2253 free_session_variables (session);
2254 session->state = FINALIZED;
2255 session->tunnel = NULL;
2256 // send message with product to client
2257 if (ALICE == session->role)
2258 session->client_notification_task =
2259 GNUNET_SCHEDULER_add_now (&prepare_client_response,
2261 // the tunnel has done its job, terminate our connection and the tunnel
2262 // the peer will be notified that the tunnel was destroyed via tunnel_destruction_handler
2263 // just close the connection, as recommended by Christian
2264 return GNUNET_SYSERR;
2269 * Handle a response we got from another service we wanted to calculate a scalarproduct with.
2271 * @param cls closure (set from #GNUNET_MESH_connect)
2272 * @param tunnel connection to the other end
2273 * @param tunnel_ctx place to store local state associated with the tunnel
2274 * @param message the actual message
2275 * @return #GNUNET_OK to keep the connection open,
2276 * #GNUNET_SYSERR to close it (we are done)
2279 handle_service_response (void *cls,
2280 struct GNUNET_MESH_Tunnel * tunnel,
2282 const struct GNUNET_MessageHeader * message)
2284 struct ServiceSession * session;
2285 const struct GNUNET_SCALARPRODUCT_service_response * msg = (const struct GNUNET_SCALARPRODUCT_service_response *) message;
2286 unsigned char * current;
2289 uint32_t contained = 0;
2293 GNUNET_assert (NULL != message);
2294 session = (struct ServiceSession *) * tunnel_ctx;
2295 // are we in the correct state?
2296 if (session->state != WAITING_FOR_SERVICE_REQUEST) {
2299 //we need at least a full message without elements attached
2300 if (sizeof (struct GNUNET_SCALARPRODUCT_service_response) + 2 * PAILLIER_ELEMENT_LENGTH > ntohs (msg->header.size)) {
2303 contained = ntohl (msg->contained_element_count);
2304 msg_size = sizeof (struct GNUNET_SCALARPRODUCT_service_response)
2305 + 2 * contained * PAILLIER_ELEMENT_LENGTH
2306 + 2 * PAILLIER_ELEMENT_LENGTH;
2307 //sanity check: is the message as long as the message_count fields suggests?
2308 if ((ntohs (msg->header.size) != msg_size) || (session->used < contained)) {
2311 session->state = WAITING_FOR_MULTIPART_TRANSMISSION;
2312 session->transferred = contained;
2314 current = (unsigned char *) &msg[1];
2315 if (0 != (rc = gcry_mpi_scan (&session->s, GCRYMPI_FMT_USG, current,
2316 PAILLIER_ELEMENT_LENGTH, &read))) {
2317 LOG_GCRY (GNUNET_ERROR_TYPE_DEBUG, "gcry_mpi_scan", rc);
2320 current += PAILLIER_ELEMENT_LENGTH;
2322 if (0 != (rc = gcry_mpi_scan (&session->s_prime, GCRYMPI_FMT_USG, current,
2323 PAILLIER_ELEMENT_LENGTH, &read))) {
2324 LOG_GCRY (GNUNET_ERROR_TYPE_DEBUG, "gcry_mpi_scan", rc);
2327 current += PAILLIER_ELEMENT_LENGTH;
2328 session->r = GNUNET_malloc (sizeof (gcry_mpi_t) * session->used);
2329 session->r_prime = GNUNET_malloc (sizeof (gcry_mpi_t) * session->used);
2330 // Convert each k[][perm] to its MPI_value
2331 for (i = 0; i < contained; i++) {
2332 if (0 != (rc = gcry_mpi_scan (&session->r[i], GCRYMPI_FMT_USG, current,
2333 PAILLIER_ELEMENT_LENGTH, &read))) {
2334 LOG_GCRY (GNUNET_ERROR_TYPE_DEBUG, "gcry_mpi_scan", rc);
2337 current += PAILLIER_ELEMENT_LENGTH;
2338 if (0 != (rc = gcry_mpi_scan (&session->r_prime[i], GCRYMPI_FMT_USG, current,
2339 PAILLIER_ELEMENT_LENGTH, &read))) {
2340 LOG_GCRY (GNUNET_ERROR_TYPE_DEBUG, "gcry_mpi_scan", rc);
2343 current += PAILLIER_ELEMENT_LENGTH;
2345 if (session->transferred != session->used)
2346 return GNUNET_OK; //wait for the other multipart chunks
2348 session->state = SERVICE_RESPONSE_RECEIVED;
2349 session->product = compute_scalar_product (session);
2350 return GNUNET_SYSERR; // terminate the tunnel right away, we are done here!
2353 GNUNET_break_op (0);
2354 free_session_variables (session);
2355 session->state = FINALIZED;
2356 session->tunnel = NULL;
2357 // send message with product to client
2358 if (ALICE == session->role)
2359 session->client_notification_task =
2360 GNUNET_SCHEDULER_add_now (&prepare_client_response,
2362 // the tunnel has done its job, terminate our connection and the tunnel
2363 // the peer will be notified that the tunnel was destroyed via tunnel_destruction_handler
2364 // just close the connection, as recommended by Christian
2365 return GNUNET_SYSERR;
2370 * Task run during shutdown.
2376 shutdown_task (void *cls,
2377 const struct GNUNET_SCHEDULER_TaskContext *tc)
2379 struct ServiceSession * session;
2380 GNUNET_log (GNUNET_ERROR_TYPE_INFO, _ ("Shutting down, initiating cleanup.\n"));
2382 do_shutdown = GNUNET_YES;
2384 // terminate all owned open tunnels.
2385 for (session = from_client_head; NULL != session; session = session->next) {
2386 if ((FINALIZED != session->state) && (NULL != session->tunnel)) {
2387 GNUNET_MESH_tunnel_destroy (session->tunnel);
2388 session->tunnel = NULL;
2390 if (GNUNET_SCHEDULER_NO_TASK != session->client_notification_task) {
2391 GNUNET_SCHEDULER_cancel (session->client_notification_task);
2392 session->client_notification_task = GNUNET_SCHEDULER_NO_TASK;
2394 if (GNUNET_SCHEDULER_NO_TASK != session->service_request_task) {
2395 GNUNET_SCHEDULER_cancel (session->service_request_task);
2396 session->service_request_task = GNUNET_SCHEDULER_NO_TASK;
2398 if (NULL != session->client) {
2399 GNUNET_SERVER_client_disconnect (session->client);
2400 session->client = NULL;
2403 for (session = from_service_head; NULL != session; session = session->next)
2404 if (NULL != session->tunnel) {
2405 GNUNET_MESH_tunnel_destroy (session->tunnel);
2406 session->tunnel = NULL;
2410 GNUNET_MESH_disconnect (my_mesh);
2417 * Initialization of the program and message handlers
2419 * @param cls closure
2420 * @param server the initialized server
2421 * @param c configuration to use
2425 struct GNUNET_SERVER_Handle *server,
2426 const struct GNUNET_CONFIGURATION_Handle *c)
2428 static const struct GNUNET_SERVER_MessageHandler server_handlers[] = {
2429 {&handle_client_request, NULL, GNUNET_MESSAGE_TYPE_SCALARPRODUCT_CLIENT_TO_ALICE, 0},
2430 {&handle_client_request, NULL, GNUNET_MESSAGE_TYPE_SCALARPRODUCT_CLIENT_TO_BOB, 0},
2433 static const struct GNUNET_MESH_MessageHandler mesh_handlers[] = {
2434 { &handle_service_request, GNUNET_MESSAGE_TYPE_SCALARPRODUCT_ALICE_TO_BOB, 0},
2435 { &handle_service_request_multipart, GNUNET_MESSAGE_TYPE_SCALARPRODUCT_ALICE_TO_BOB_MULTIPART, 0},
2436 { &handle_service_response, GNUNET_MESSAGE_TYPE_SCALARPRODUCT_BOB_TO_ALICE, 0},
2437 { &handle_service_response_multipart, GNUNET_MESSAGE_TYPE_SCALARPRODUCT_BOB_TO_ALICE_MULTIPART, 0},
2440 static const uint32_t ports[] = {
2441 GNUNET_APPLICATION_TYPE_SCALARPRODUCT,
2444 //generate private/public key set
2445 GNUNET_log (GNUNET_ERROR_TYPE_INFO, _ ("Generating Paillier-Keyset.\n"));
2447 // register server callbacks and disconnect handler
2448 GNUNET_SERVER_add_handlers (server, server_handlers);
2449 GNUNET_SERVER_disconnect_notify (server,
2450 &handle_client_disconnect,
2452 GNUNET_break (GNUNET_OK ==
2453 GNUNET_CRYPTO_get_peer_identity (c,
2455 my_mesh = GNUNET_MESH_connect (c, NULL,
2456 &tunnel_incoming_handler,
2457 &tunnel_destruction_handler,
2458 mesh_handlers, ports);
2460 GNUNET_log (GNUNET_ERROR_TYPE_ERROR, _ ("Connect to MESH failed\n"));
2461 GNUNET_SCHEDULER_shutdown ();
2464 GNUNET_log (GNUNET_ERROR_TYPE_INFO, _ ("Mesh initialized\n"));
2465 GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_FOREVER_REL,
2472 * The main function for the scalarproduct service.
2474 * @param argc number of arguments from the command line
2475 * @param argv command line arguments
2476 * @return 0 ok, 1 on error
2479 main (int argc, char *const *argv)
2481 return (GNUNET_OK ==
2482 GNUNET_SERVICE_run (argc, argv,
2484 GNUNET_SERVICE_OPTION_NONE,
2485 &run, NULL)) ? 0 : 1;
2488 /* end of gnunet-service-scalarproduct.c */