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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 * channel-handle associated with our mesh handle
208 struct GNUNET_MESH_Channel * channel;
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 * decrypts an element using the paillier crypto system
476 * @param m plaintext (output)
477 * @param c the ciphertext
478 * @param mu the modifier to correct encryption
479 * @param lambda the private exponent
480 * @param n the outer module for decryption
481 * @param n_square the inner module for decryption
484 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)
486 gcry_mpi_powm (m, c, lambda, n_square);
487 gcry_mpi_sub_ui (m, m, 1);
488 gcry_mpi_div (m, NULL, m, n, 0);
489 gcry_mpi_mulm (m, m, mu, n);
494 * computes the square sum over a vector of a given length.
496 * @param vector the vector to encrypt
497 * @param length the length of the vector
498 * @return an MPI value containing the calculated sum, never NULL
501 compute_square_sum (gcry_mpi_t * vector, uint32_t length)
507 GNUNET_assert (sum = gcry_mpi_new (0));
508 GNUNET_assert (elem = gcry_mpi_new (0));
510 // calculare E(sum (ai ^ 2), publickey)
511 for (i = 0; i < length; i++) {
512 gcry_mpi_mul (elem, vector[i], vector[i]);
513 gcry_mpi_add (sum, sum, elem);
515 gcry_mpi_release (elem);
522 * Primitive callback for copying over a message, as they
523 * usually are too complex to be handled in the callback itself.
524 * clears a session-callback, if a session was handed over and the transmit handle was stored
526 * @param cls the message object
527 * @param size the size of the buffer we got
528 * @param buf the buffer to copy the message to
529 * @return 0 if we couldn't copy, else the size copied over
532 do_send_message (void *cls, size_t size, void *buf)
534 struct ServiceSession * session = cls;
539 if (ntohs (session->msg->size) != size) {
544 type = ntohs (session->msg->type);
545 memcpy (buf, session->msg, size);
546 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
547 "Sent a message of type %hu.\n",
549 GNUNET_free (session->msg);
554 case GNUNET_MESSAGE_TYPE_SCALARPRODUCT_SERVICE_TO_CLIENT:
555 session->state = FINALIZED;
556 session->client_transmit_handle = NULL;
559 case GNUNET_MESSAGE_TYPE_SCALARPRODUCT_ALICE_TO_BOB:
560 case GNUNET_MESSAGE_TYPE_SCALARPRODUCT_ALICE_TO_BOB_MULTIPART:
561 session->service_transmit_handle = NULL;
562 if (session->state == WAITING_FOR_MULTIPART_TRANSMISSION)
563 prepare_service_request_multipart (session);
566 case GNUNET_MESSAGE_TYPE_SCALARPRODUCT_BOB_TO_ALICE:
567 case GNUNET_MESSAGE_TYPE_SCALARPRODUCT_BOB_TO_ALICE_MULTIPART:
568 session->service_transmit_handle = NULL;
569 if (session->state == WAITING_FOR_MULTIPART_TRANSMISSION)
570 prepare_service_response_multipart (session);
582 * initializes a new vector with fresh MPI values (=0) of a given length
584 * @param length of the vector to create
585 * @return the initialized vector, never NULL
588 initialize_mpi_vector (uint32_t length)
591 gcry_mpi_t * output = GNUNET_malloc (sizeof (gcry_mpi_t) * length);
593 for (i = 0; i < length; i++)
594 GNUNET_assert (NULL != (output[i] = gcry_mpi_new (0)));
600 * permutes an MPI vector according to the given permutation vector
602 * @param vector the vector to permuted
603 * @param perm the permutation to use
604 * @param length the length of the vectors
605 * @return the permuted vector (same as input), never NULL
608 permute_vector (gcry_mpi_t * vector,
612 gcry_mpi_t tmp[length];
615 GNUNET_assert (length > 0);
618 memcpy (tmp, vector, length * sizeof (gcry_mpi_t));
620 // permute vector according to given
621 for (i = 0; i < length; i++)
622 vector[i] = tmp[perm[i]];
629 * Finds a not terminated client/service session in the
630 * given DLL based on session key, element count and state.
632 * @param tail - the tail of the DLL
633 * @param key - the key we want to search for
634 * @param element_count - the total element count of the dataset (session->total)
635 * @param state - a pointer to the state the session should be in, NULL to ignore
636 * @param peerid - a pointer to the peer ID of the associated peer, NULL to ignore
637 * @return a pointer to a matching session, or NULL
639 static struct ServiceSession *
640 find_matching_session (struct ServiceSession * tail,
641 const struct GNUNET_HashCode * key,
642 uint32_t element_count,
643 enum SessionState * state,
644 const struct GNUNET_PeerIdentity * peerid)
646 struct ServiceSession * curr;
648 for (curr = tail; NULL != curr; curr = curr->prev) {
649 // if the key matches, and the element_count is same
650 if ((!memcmp (&curr->key, key, sizeof (struct GNUNET_HashCode)))
651 && (curr->total == element_count)) {
652 // if incoming state is NULL OR is same as state of the queued request
653 if ((NULL == state) || (curr->state == *state)) {
654 // if peerid is NULL OR same as the peer Id in the queued request
656 || (!memcmp (&curr->peer, peerid, sizeof (struct GNUNET_PeerIdentity))))
657 // matches and is not an already terminated session
667 * Safely frees ALL memory areas referenced by a session.
669 * @param session - the session to free elements from
672 free_session_variables (struct ServiceSession * session)
677 for (i = 0; i < session->used; i++)
678 if (session->a[i]) gcry_mpi_release (session->a[i]);
679 GNUNET_free (session->a);
683 GNUNET_free (session->mask);
684 session->mask = NULL;
687 for (i = 0; i < session->used; i++)
688 if (session->r[i]) gcry_mpi_release (session->r[i]);
689 GNUNET_free (session->r);
692 if (session->r_prime) {
693 for (i = 0; i < session->used; i++)
694 if (session->r_prime[i]) gcry_mpi_release (session->r_prime[i]);
695 GNUNET_free (session->r_prime);
696 session->r_prime = NULL;
699 gcry_mpi_release (session->s);
703 if (session->s_prime) {
704 gcry_mpi_release (session->s_prime);
705 session->s_prime = NULL;
708 if (session->product) {
709 gcry_mpi_release (session->product);
710 session->product = NULL;
713 if (session->remote_pubkey) {
714 gcry_sexp_release (session->remote_pubkey);
715 session->remote_pubkey = NULL;
718 if (session->vector) {
719 GNUNET_free_non_null (session->vector);
723 ///////////////////////////////////////////////////////////////////////////////
724 // Event and Message Handlers
725 ///////////////////////////////////////////////////////////////////////////////
729 * A client disconnected.
731 * Remove the associated session(s), release data structures
732 * and cancel pending outgoing transmissions to the client.
733 * if the session has not yet completed, we also cancel Alice's request to Bob.
735 * @param cls closure, NULL
736 * @param client identification of the client
739 handle_client_disconnect (void *cls,
740 struct GNUNET_SERVER_Client *client)
742 struct ServiceSession *session;
745 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
746 _ ("Client (%p) disconnected from us.\n"), client);
750 session = GNUNET_SERVER_client_get_user_context (client, struct ServiceSession);
753 GNUNET_CONTAINER_DLL_remove (from_client_head, from_client_tail, session);
755 if (!(session->role == BOB && session->state == FINALIZED)) {
756 //we MUST terminate any client message underway
757 if (session->service_transmit_handle && session->channel)
758 GNUNET_MESH_notify_transmit_ready_cancel (session->service_transmit_handle);
759 if (session->channel && session->state == WAITING_FOR_SERVICE_RESPONSE)
760 GNUNET_MESH_channel_destroy (session->channel);
762 if (GNUNET_SCHEDULER_NO_TASK != session->client_notification_task) {
763 GNUNET_SCHEDULER_cancel (session->client_notification_task);
764 session->client_notification_task = GNUNET_SCHEDULER_NO_TASK;
766 if (GNUNET_SCHEDULER_NO_TASK != session->service_request_task) {
767 GNUNET_SCHEDULER_cancel (session->service_request_task);
768 session->service_request_task = GNUNET_SCHEDULER_NO_TASK;
770 if (NULL != session->client_transmit_handle) {
771 GNUNET_SERVER_notify_transmit_ready_cancel (session->client_transmit_handle);
772 session->client_transmit_handle = NULL;
774 free_session_variables (session);
775 GNUNET_free (session);
780 * Notify the client that the session has succeeded or failed completely.
781 * This message gets sent to
782 * * alice's client if bob disconnected or to
783 * * bob's client if the operation completed or alice disconnected
785 * @param cls the associated client session
786 * @param tc the task context handed to us by the scheduler, unused
789 prepare_client_end_notification (void * cls,
790 const struct GNUNET_SCHEDULER_TaskContext * tc)
792 struct ServiceSession * session = cls;
793 struct GNUNET_SCALARPRODUCT_client_response * msg;
795 session->client_notification_task = GNUNET_SCHEDULER_NO_TASK;
797 msg = GNUNET_new (struct GNUNET_SCALARPRODUCT_client_response);
798 msg->header.type = htons (GNUNET_MESSAGE_TYPE_SCALARPRODUCT_SERVICE_TO_CLIENT);
799 memcpy (&msg->key, &session->key, sizeof (struct GNUNET_HashCode));
800 memcpy (&msg->peer, &session->peer, sizeof ( struct GNUNET_PeerIdentity));
801 msg->header.size = htons (sizeof (struct GNUNET_SCALARPRODUCT_client_response));
802 // signal error if not signalized, positive result-range field but zero length.
803 msg->product_length = htonl (0);
804 msg->range = (session->state == FINALIZED) ? 0 : -1;
806 session->msg = &msg->header;
808 //transmit this message to our client
809 session->client_transmit_handle =
810 GNUNET_SERVER_notify_transmit_ready (session->client,
811 sizeof (struct GNUNET_SCALARPRODUCT_client_response),
812 GNUNET_TIME_UNIT_FOREVER_REL,
816 // if we could not even queue our request, something is wrong
817 if (NULL == session->client_transmit_handle) {
818 GNUNET_log (GNUNET_ERROR_TYPE_WARNING, _ ("Could not send message to client (%p)!\n"), session->client);
819 // usually gets freed by do_send_message
824 GNUNET_log (GNUNET_ERROR_TYPE_INFO, _ ("Sending session-end notification to client (%p) for session %s\n"), &session->client, GNUNET_h2s (&session->key));
826 free_session_variables (session);
831 * prepare the response we will send to alice or bobs' clients.
832 * in Bobs case the product will be NULL.
834 * @param cls the session associated with our client.
835 * @param tc the task context handed to us by the scheduler, unused
838 prepare_client_response (void *cls,
839 const struct GNUNET_SCHEDULER_TaskContext *tc)
841 struct ServiceSession * session = cls;
842 struct GNUNET_SCALARPRODUCT_client_response * msg;
843 unsigned char * product_exported = NULL;
844 size_t product_length = 0;
845 uint32_t msg_length = 0;
850 session->client_notification_task = GNUNET_SCHEDULER_NO_TASK;
852 if (session->product) {
853 gcry_mpi_t value = gcry_mpi_new (0);
855 sign = gcry_mpi_cmp_ui (session->product, 0);
856 // libgcrypt can not handle a print of a negative number
857 // if (a->sign) return gcry_error (GPG_ERR_INTERNAL); /* Can't handle it yet. */
859 gcry_mpi_sub (value, value, session->product);
863 gcry_mpi_add (value, value, session->product);
868 gcry_mpi_release (session->product);
869 session->product = NULL;
871 // get representation as string
873 && (0 != (rc = gcry_mpi_aprint (GCRYMPI_FMT_STD,
877 LOG_GCRY (GNUNET_ERROR_TYPE_ERROR, "gcry_mpi_scan", rc);
879 range = -1; // signal error with product-length = 0 and range = -1
881 gcry_mpi_release (value);
884 msg_length = sizeof (struct GNUNET_SCALARPRODUCT_client_response) +product_length;
885 msg = GNUNET_malloc (msg_length);
886 msg->key = session->key;
887 msg->peer = session->peer;
888 if (product_exported != NULL)
890 memcpy (&msg[1], product_exported, product_length);
891 GNUNET_free (product_exported);
893 msg->header.type = htons (GNUNET_MESSAGE_TYPE_SCALARPRODUCT_SERVICE_TO_CLIENT);
894 msg->header.size = htons (msg_length);
896 msg->product_length = htonl (product_length);
898 session->msg = (struct GNUNET_MessageHeader *) msg;
899 //transmit this message to our client
900 session->client_transmit_handle =
901 GNUNET_SERVER_notify_transmit_ready (session->client,
903 GNUNET_TIME_UNIT_FOREVER_REL,
906 if (NULL == session->client_transmit_handle) {
907 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
908 _ ("Could not send message to client (%p)!\n"),
910 session->client = NULL;
911 // callback was not called!
916 // gracefully sent message, just terminate session structure
917 GNUNET_log (GNUNET_ERROR_TYPE_INFO,
918 _ ("Sent result to client (%p), this session (%s) has ended!\n"),
920 GNUNET_h2s (&session->key));
921 free_session_variables (session);
926 * Send a multipart chunk of a service response from bob to alice.
927 * This element only contains the two permutations of R, R'.
929 * @param cls the associated service session
932 prepare_service_response_multipart (void *cls)
934 struct ServiceSession * session = cls;
935 unsigned char * current;
936 unsigned char * element_exported;
937 struct GNUNET_SCALARPRODUCT_multipart_message * msg;
941 size_t element_length = 0; // initialized by gcry_mpi_print, but the compiler doesn't know that
943 msg_length = sizeof (struct GNUNET_SCALARPRODUCT_multipart_message);
944 todo_count = session->used - session->transferred;
946 if (todo_count > MULTIPART_ELEMENT_CAPACITY / 2)
947 // send the currently possible maximum chunk, we always transfer both permutations
948 todo_count = MULTIPART_ELEMENT_CAPACITY / 2;
950 msg_length += todo_count * PAILLIER_ELEMENT_LENGTH * 2;
951 msg = GNUNET_malloc (msg_length);
952 msg->header.type = htons (GNUNET_MESSAGE_TYPE_SCALARPRODUCT_ALICE_TO_BOB_MULTIPART);
953 msg->header.size = htons (msg_length);
954 msg->multipart_element_count = htonl (todo_count);
956 element_exported = GNUNET_malloc (PAILLIER_ELEMENT_LENGTH);
957 current = (unsigned char *) &msg[1];
959 for (i = session->transferred; i < session->transferred + todo_count; i++) {
961 memset (element_exported, 0, PAILLIER_ELEMENT_LENGTH);
962 GNUNET_assert (0 == gcry_mpi_print (GCRYMPI_FMT_USG,
963 element_exported, PAILLIER_ELEMENT_LENGTH,
966 adjust (element_exported, element_length, PAILLIER_ELEMENT_LENGTH);
967 memcpy (current, element_exported, PAILLIER_ELEMENT_LENGTH);
968 current += PAILLIER_ELEMENT_LENGTH;
970 memset (element_exported, 0, PAILLIER_ELEMENT_LENGTH);
971 GNUNET_assert (0 == gcry_mpi_print (GCRYMPI_FMT_USG,
972 element_exported, PAILLIER_ELEMENT_LENGTH,
974 session->r_prime[i]));
975 adjust (element_exported, element_length, PAILLIER_ELEMENT_LENGTH);
976 memcpy (current, element_exported, PAILLIER_ELEMENT_LENGTH);
977 current += PAILLIER_ELEMENT_LENGTH;
979 GNUNET_free (element_exported);
980 for (i = session->transferred; i < session->transferred; i++) {
981 gcry_mpi_release (session->r_prime[i]);
982 session->r_prime[i] = NULL;
983 gcry_mpi_release (session->r[i]);
984 session->r[i] = NULL;
986 session->transferred += todo_count;
987 session->msg = (struct GNUNET_MessageHeader *) msg;
988 session->service_transmit_handle =
989 GNUNET_MESH_notify_transmit_ready (session->channel,
991 GNUNET_TIME_UNIT_FOREVER_REL,
995 //disconnect our client
996 if (NULL == session->service_transmit_handle) {
997 GNUNET_log (GNUNET_ERROR_TYPE_ERROR, _ ("Could not send service-response message via mesh!)\n"));
998 session->state = FINALIZED;
1000 session->response->client_notification_task =
1001 GNUNET_SCHEDULER_add_now (&prepare_client_end_notification,
1005 if (session->transferred != session->used)
1007 session->state = WAITING_FOR_MULTIPART_TRANSMISSION;
1010 session->state = FINALIZED;
1011 GNUNET_free(session->r);
1012 GNUNET_free(session->r_prime);
1013 session->r_prime = NULL;
1021 * generates the response message to be sent to alice after computing
1022 * the values (1), (2), S and S'
1023 * (1)[]: $E_A(a_{pi(i)}) times E_A(- r_{pi(i)} - b_{pi(i)}) &= E_A(a_{pi(i)} - r_{pi(i)} - b_{pi(i)})$
1024 * (2)[]: $E_A(a_{pi'(i)}) times E_A(- r_{pi'(i)}) &= E_A(a_{pi'(i)} - r_{pi'(i)})$
1025 * S: $S := E_A(sum (r_i + b_i)^2)$
1026 * S': $S' := E_A(sum r_i^2)$
1028 * @param s S: $S := E_A(sum (r_i + b_i)^2)$
1029 * @param s_prime S': $S' := E_A(sum r_i^2)$
1030 * @param session the associated requesting session with alice
1031 * @return #GNUNET_NO if we could not send our message
1032 * #GNUNET_OK if the operation succeeded
1035 prepare_service_response (gcry_mpi_t s,
1037 struct ServiceSession * session)
1039 struct GNUNET_SCALARPRODUCT_service_response * msg;
1040 uint32_t msg_length = 0;
1041 unsigned char * current = NULL;
1042 unsigned char * element_exported = NULL;
1043 size_t element_length = 0;
1046 msg_length = sizeof (struct GNUNET_SCALARPRODUCT_service_response)
1047 + 2 * PAILLIER_ELEMENT_LENGTH; // s, stick
1049 if (GNUNET_SERVER_MAX_MESSAGE_SIZE > msg_length + 2 * session->used * PAILLIER_ELEMENT_LENGTH) { //kp, kq
1050 msg_length += +2 * session->used * PAILLIER_ELEMENT_LENGTH;
1051 session->transferred = session->used;
1054 session->transferred = (GNUNET_SERVER_MAX_MESSAGE_SIZE - 1 - msg_length) / (PAILLIER_ELEMENT_LENGTH * 2);
1057 msg = GNUNET_malloc (msg_length);
1059 msg->header.type = htons (GNUNET_MESSAGE_TYPE_SCALARPRODUCT_BOB_TO_ALICE);
1060 msg->header.size = htons (msg_length);
1061 msg->total_element_count = htonl (session->total);
1062 msg->used_element_count = htonl (session->used);
1063 msg->contained_element_count = htonl (session->transferred);
1064 memcpy (&msg->key, &session->key, sizeof (struct GNUNET_HashCode));
1065 current = (unsigned char *) &msg[1];
1067 element_exported = GNUNET_malloc (PAILLIER_ELEMENT_LENGTH);
1068 // 4 times the same logics with slight variations.
1069 // doesn't really justify having 2 functions for that
1070 // so i put it into blocks to enhance readability
1072 memset (element_exported, 0, PAILLIER_ELEMENT_LENGTH);
1073 GNUNET_assert (0 == gcry_mpi_print (GCRYMPI_FMT_USG,
1074 element_exported, PAILLIER_ELEMENT_LENGTH,
1077 adjust (element_exported, element_length, PAILLIER_ELEMENT_LENGTH);
1078 memcpy (current, element_exported, PAILLIER_ELEMENT_LENGTH);
1079 current += PAILLIER_ELEMENT_LENGTH;
1082 memset (element_exported, 0, PAILLIER_ELEMENT_LENGTH);
1083 GNUNET_assert (0 == gcry_mpi_print (GCRYMPI_FMT_USG,
1084 element_exported, PAILLIER_ELEMENT_LENGTH,
1087 adjust (element_exported, element_length, PAILLIER_ELEMENT_LENGTH);
1088 memcpy (current, element_exported, PAILLIER_ELEMENT_LENGTH);
1089 current += PAILLIER_ELEMENT_LENGTH;
1092 for (i = 0; i < session->transferred; i++) {
1094 memset (element_exported, 0, PAILLIER_ELEMENT_LENGTH);
1095 GNUNET_assert (0 == gcry_mpi_print (GCRYMPI_FMT_USG,
1096 element_exported, PAILLIER_ELEMENT_LENGTH,
1099 adjust (element_exported, element_length, PAILLIER_ELEMENT_LENGTH);
1100 memcpy (current, element_exported, PAILLIER_ELEMENT_LENGTH);
1101 current += PAILLIER_ELEMENT_LENGTH;
1103 memset (element_exported, 0, PAILLIER_ELEMENT_LENGTH);
1104 GNUNET_assert (0 == gcry_mpi_print (GCRYMPI_FMT_USG,
1105 element_exported, PAILLIER_ELEMENT_LENGTH,
1107 session->r_prime[i]));
1108 adjust (element_exported, element_length, PAILLIER_ELEMENT_LENGTH);
1109 memcpy (current, element_exported, PAILLIER_ELEMENT_LENGTH);
1110 current += PAILLIER_ELEMENT_LENGTH;
1113 GNUNET_free (element_exported);
1114 for (i = 0; i < session->transferred; i++) {
1115 gcry_mpi_release (session->r_prime[i]);
1116 session->r_prime[i] = NULL;
1117 gcry_mpi_release (session->r[i]);
1118 session->r[i] = NULL;
1120 gcry_mpi_release (s);
1122 gcry_mpi_release (s_prime);
1123 session->s_prime = NULL;
1125 session->msg = (struct GNUNET_MessageHeader *) msg;
1126 session->service_transmit_handle =
1127 GNUNET_MESH_notify_transmit_ready (session->channel,
1129 GNUNET_TIME_UNIT_FOREVER_REL,
1133 //disconnect our client
1134 if (NULL == session->service_transmit_handle) {
1135 GNUNET_log (GNUNET_ERROR_TYPE_ERROR, _ ("Could not send service-response message via mesh!)\n"));
1136 session->state = FINALIZED;
1138 session->response->client_notification_task =
1139 GNUNET_SCHEDULER_add_now (&prepare_client_end_notification,
1143 if (session->transferred != session->used)
1145 session->state = WAITING_FOR_MULTIPART_TRANSMISSION;
1148 session->state = FINALIZED;
1149 GNUNET_free(session->r);
1150 GNUNET_free(session->r_prime);
1151 session->r_prime = NULL;
1161 * compute the values
1162 * (1)[]: $E_A(a_{pi(i)}) otimes E_A(- r_{pi(i)} - b_{pi(i)}) &= E_A(a_{pi(i)} - r_{pi(i)} - b_{pi(i)})$
1163 * (2)[]: $E_A(a_{pi'(i)}) otimes E_A(- r_{pi'(i)}) &= E_A(a_{pi'(i)} - r_{pi'(i)})$
1164 * S: $S := E_A(sum (r_i + b_i)^2)$
1165 * S': $S' := E_A(sum r_i^2)$
1167 * @param request the requesting session + bob's requesting peer
1168 * @param response the responding session + bob's client handle
1169 * @return GNUNET_SYSERR if the computation failed
1170 * GNUNET_OK if everything went well.
1173 compute_service_response (struct ServiceSession * request,
1174 struct ServiceSession * response)
1178 int ret = GNUNET_SYSERR;
1182 gcry_mpi_t * rand = NULL;
1183 gcry_mpi_t * r = NULL;
1184 struct GNUNET_CRYPTO_PaillierCiphertext * R;
1185 gcry_mpi_t * r_prime = NULL;
1186 struct GNUNET_CRYPTO_PaillierCiphertext * R_prime;
1189 gcry_mpi_t * a_pi_prime;
1191 gcry_mpi_t * rand_pi;
1192 gcry_mpi_t * rand_pi_prime;
1193 gcry_mpi_t s = NULL;
1194 gcry_mpi_t s_prime = NULL;
1198 count = request->used;
1200 b = GNUNET_malloc (sizeof (gcry_mpi_t) * count);
1201 a_pi = GNUNET_malloc (sizeof (gcry_mpi_t) * count);
1202 b_pi = GNUNET_malloc (sizeof (gcry_mpi_t) * count);
1203 a_pi_prime = GNUNET_malloc (sizeof (gcry_mpi_t) * count);
1204 rand_pi = GNUNET_malloc (sizeof (gcry_mpi_t) * count);
1205 rand_pi_prime = GNUNET_malloc (sizeof (gcry_mpi_t) * count);
1207 // convert responder session to from long to mpi
1208 for (i = 0, j = 0; i < response->total && j < count; i++)
1210 if (request->mask[i / 8] & (1 << (i % 8)))
1212 value = response->vector[i] >= 0 ? response->vector[i] : -response->vector[i];
1213 // long to gcry_mpi_t
1214 if (0 > response->vector[i])
1216 b[j] = gcry_mpi_new (0);
1217 gcry_mpi_sub_ui (b[j], b[j], value);
1220 b[j] = gcry_mpi_set_ui (NULL, value);
1225 GNUNET_free (response->vector);
1226 response->vector = NULL;
1230 // generate r, p and q
1231 rand = initialize_mpi_vector (count);
1232 for (i = 0; i < count; i++)
1236 svalue = (int32_t) GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK, UINT32_MAX);
1238 // long to gcry_mpi_t
1240 gcry_mpi_sub_ui (rand[i],
1244 rand[i] = gcry_mpi_set_ui (rand[i], svalue);
1246 p = GNUNET_CRYPTO_random_permute (GNUNET_CRYPTO_QUALITY_WEAK, count);
1247 q = GNUNET_CRYPTO_random_permute (GNUNET_CRYPTO_QUALITY_WEAK, count);
1248 //initialize the result vectors
1249 r = initialize_mpi_vector (count);
1250 r_prime = initialize_mpi_vector (count);
1252 // copy the REFERNCES of a, b and r into aq and bq. we will not change
1253 // those values, thus we can work with the references
1254 memcpy (a_pi, request->a, sizeof (gcry_mpi_t) * count);
1255 memcpy (a_pi_prime, request->a, sizeof (gcry_mpi_t) * count);
1256 memcpy (b_pi, b, sizeof (gcry_mpi_t) * count);
1257 memcpy (rand_pi, rand, sizeof (gcry_mpi_t) * count);
1258 memcpy (rand_pi_prime, rand, sizeof (gcry_mpi_t) * count);
1260 // generate p and q permutations for a, b and r
1261 GNUNET_assert (permute_vector (a_pi, p, count));
1262 GNUNET_assert (permute_vector (b_pi, p, count));
1263 GNUNET_assert (permute_vector (rand_pi, p, count));
1264 GNUNET_assert (permute_vector (a_pi_prime, q, count));
1265 GNUNET_assert (permute_vector (rand_pi_prime, q, count));
1267 // encrypt the element
1268 // for the sake of readability I decided to have dedicated permutation
1269 // vectors, which get rid of all the lookups in p/q.
1270 // however, ap/aq are not absolutely necessary but are just abstraction
1271 // Calculate Kp = E(S + a_pi) (+) E(S - r_pi - b_pi)
1272 for (i = 0; i < count; i++)
1274 // E(S - r_pi - b_pi)
1275 gcry_mpi_sub (r[i], my_offset, rand_pi[i]);
1276 gcry_mpi_sub (r[i], r[i], b_pi[i]);
1277 GNUNET_CRYPTO_paillier_encrypt (&request->remote_pubkey,
1281 // E(S - r_pi - b_pi) * E(S + a_pi) == E(2*S + a - r - b)
1282 GNUNET_CRYPTO_paillier_hom_add (&request->remote_pubkey,
1289 GNUNET_free (rand_pi);
1291 // Calculate Kq = E(S + a_qi) (+) E(S - r_qi)
1292 for (i = 0; i < count; i++)
1295 gcry_mpi_sub (r_prime[i], my_offset, rand_pi_prime[i]);
1296 GNUNET_CRYPTO_paillier_encrypt (&request->remote_pubkey,
1300 // E(S - r_qi) * E(S + a_qi) == E(2*S + a_qi - r_qi)
1301 GNUNET_CRYPTO_paillier_hom_add (&request->remote_pubkey,
1306 GNUNET_free (a_pi_prime);
1307 GNUNET_free (rand_pi_prime);
1310 request->r_prime = r_prime;
1311 request->response = response;
1313 // Calculate S' = E(SUM( r_i^2 ))
1314 s_prime = compute_square_sum (rand, count);
1315 encrypt_element (s_prime, s_prime, remote_g, remote_n, remote_nsquare);
1317 // Calculate S = E(SUM( (r_i + b_i)^2 ))
1318 for (i = 0; i < count; i++) {
1319 gcry_mpi_add (rand[i], rand[i], b[i]);
1321 s = compute_square_sum (rand, count);
1322 encrypt_element (s, s, remote_g, remote_n, remote_nsquare);
1323 gcry_mpi_release (remote_n);
1324 gcry_mpi_release (remote_g);
1325 gcry_mpi_release (remote_nsquare);
1327 // release r and tmp
1328 for (i = 0; i < count; i++)
1329 // rp, rq, aq, ap, bp, bq are released along with a, r, b respectively, (a and b are handled at except:)
1330 gcry_mpi_release (rand[i]);
1332 // copy the r[], r_prime[], S and Stick into a new message, prepare_service_response frees these
1333 if (GNUNET_YES != prepare_service_response (s, s_prime, request))
1334 GNUNET_log (GNUNET_ERROR_TYPE_INFO, _ ("Failed to communicate with `%s', scalar product calculation aborted.\n"),
1335 GNUNET_i2s (&request->peer));
1340 for (i = 0; i < count; i++)
1342 gcry_mpi_release (b[i]);
1343 gcry_mpi_release (request->a[i]);
1347 GNUNET_free (request->a);
1349 GNUNET_free_non_null (p);
1350 GNUNET_free_non_null (q);
1357 * Send a multi part chunk of a service request from alice to bob.
1358 * This element only contains a part of the elements-vector (session->a[]),
1359 * mask and public key set have to be contained within the first message
1361 * This allows a ~32kbit key length while using 32000 elements or 62000 elements per request.
1363 * @param cls the associated service session
1366 prepare_service_request_multipart (void *cls)
1368 struct ServiceSession * session = cls;
1369 unsigned char * current;
1370 unsigned char * element_exported;
1371 struct GNUNET_SCALARPRODUCT_multipart_message * msg;
1374 uint32_t msg_length;
1375 uint32_t todo_count;
1376 size_t element_length = 0; // initialized by gcry_mpi_print, but the compiler doesn't know that
1380 msg_length = sizeof (struct GNUNET_SCALARPRODUCT_multipart_message);
1381 todo_count = session->used - session->transferred;
1383 if (todo_count > MULTIPART_ELEMENT_CAPACITY)
1384 // send the currently possible maximum chunk
1385 todo_count = MULTIPART_ELEMENT_CAPACITY;
1387 msg_length += todo_count * PAILLIER_ELEMENT_LENGTH;
1388 msg = GNUNET_malloc (msg_length);
1389 msg->header.type = htons (GNUNET_MESSAGE_TYPE_SCALARPRODUCT_ALICE_TO_BOB_MULTIPART);
1390 msg->header.size = htons (msg_length);
1391 msg->multipart_element_count = htonl (todo_count);
1393 element_exported = GNUNET_malloc (PAILLIER_ELEMENT_LENGTH);
1394 a = gcry_mpi_new (KEYBITS * 2);
1395 current = (unsigned char *) &msg[1];
1396 // encrypt our vector and generate string representations
1397 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->channel, 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 channel!\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 channel 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->channel, 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 channel!\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)
1675 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1676 _("Got client-request-session with key %s, preparing channel to remote service.\n"),
1677 GNUNET_h2s (&session->key));
1679 session->role = ALICE;
1681 session->mask = GNUNET_malloc (mask_length);
1682 memcpy (session->mask, &vector[element_count], mask_length);
1684 // copy over the elements
1686 for (i = 0; i < element_count; i++)
1688 session->vector[i] = ntohl (vector[i]);
1689 if (session->vector[i] == 0)
1690 session->mask[i / 8] &= ~(1 << (i % 8));
1691 if (session->mask[i / 8] & (1 << (i % 8)))
1695 if (0 == session->used)
1697 GNUNET_break_op (0);
1698 GNUNET_free (session->vector);
1699 GNUNET_free (session);
1700 GNUNET_SERVER_receive_done (client, GNUNET_SYSERR);
1703 //session with ourself makes no sense!
1704 if (!memcmp (&msg->peer, &me, sizeof (struct GNUNET_PeerIdentity)))
1707 GNUNET_free (session->vector);
1708 GNUNET_free (session);
1709 GNUNET_SERVER_receive_done (client, GNUNET_SYSERR);
1713 memcpy (&session->peer, &msg->peer, sizeof (struct GNUNET_PeerIdentity));
1714 GNUNET_log (GNUNET_ERROR_TYPE_INFO,
1715 _ ("Creating new channel for session with key %s.\n"),
1716 GNUNET_h2s (&session->key));
1717 session->channel = GNUNET_MESH_channel_create (my_mesh, session,
1719 GNUNET_APPLICATION_TYPE_SCALARPRODUCT,
1720 GNUNET_MESH_OPTION_RELIABLE);
1721 //prepare_service_request, channel_peer_disconnect_handler,
1722 if (!session->channel) {
1724 GNUNET_free (session->vector);
1725 GNUNET_free (session);
1726 GNUNET_SERVER_receive_done (client, GNUNET_SYSERR);
1729 GNUNET_SERVER_client_set_user_context (client, session);
1730 GNUNET_CONTAINER_DLL_insert (from_client_head, from_client_tail, session);
1732 session->state = CLIENT_REQUEST_RECEIVED;
1733 session->service_request_task =
1734 GNUNET_SCHEDULER_add_now (&prepare_service_request,
1740 struct ServiceSession * requesting_session;
1741 enum SessionState needed_state = SERVICE_REQUEST_RECEIVED;
1743 session->role = BOB;
1744 session->mask = NULL;
1745 // copy over the elements
1746 session->used = element_count;
1747 for (i = 0; i < element_count; i++)
1748 session->vector[i] = ntohl (vector[i]);
1749 session->state = CLIENT_RESPONSE_RECEIVED;
1751 GNUNET_SERVER_client_set_user_context (client, session);
1752 GNUNET_CONTAINER_DLL_insert (from_client_head, from_client_tail, session);
1754 //check if service queue contains a matching request
1755 requesting_session = find_matching_session (from_service_tail,
1758 &needed_state, NULL);
1759 if (NULL != requesting_session)
1761 GNUNET_log (GNUNET_ERROR_TYPE_INFO,
1762 _("Got client-responder-session with key %s and a matching service-request-session set, processing.\n"),
1763 GNUNET_h2s (&session->key));
1764 if (GNUNET_OK != compute_service_response (requesting_session, session))
1765 session->client_notification_task =
1766 GNUNET_SCHEDULER_add_now (&prepare_client_end_notification,
1772 GNUNET_log (GNUNET_ERROR_TYPE_INFO,
1773 _("Got client-responder-session with key %s but NO matching service-request-session set, queuing element for later use.\n"),
1774 GNUNET_h2s (&session->key));
1775 // no matching session exists yet, store the response
1776 // for later processing by handle_service_request()
1779 GNUNET_SERVER_receive_done (client, GNUNET_YES);
1784 * Function called for inbound channels.
1786 * @param cls closure
1787 * @param channel new handle to the channel
1788 * @param initiator peer that started the channel
1789 * @param port unused
1790 * @param options unused
1792 * @return session associated with the channel
1795 channel_incoming_handler (void *cls,
1796 struct GNUNET_MESH_Channel *channel,
1797 const struct GNUNET_PeerIdentity *initiator,
1798 uint32_t port, enum GNUNET_MESH_ChannelOption options)
1800 struct ServiceSession * c = GNUNET_new (struct ServiceSession);
1802 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1803 _("New incoming channel from peer %s.\n"),
1804 GNUNET_i2s (initiator));
1806 c->peer = *initiator;
1807 c->channel = channel;
1809 c->state = WAITING_FOR_SERVICE_REQUEST;
1815 * Function called whenever a channel is destroyed. Should clean up
1816 * any associated state.
1818 * It must NOT call GNUNET_MESH_channel_destroy on the channel.
1820 * @param cls closure (set from GNUNET_MESH_connect)
1821 * @param channel connection to the other end (henceforth invalid)
1822 * @param channel_ctx place where local state associated
1823 * with the channel is stored
1826 channel_destruction_handler (void *cls,
1827 const struct GNUNET_MESH_Channel *channel,
1830 struct ServiceSession * session = channel_ctx;
1831 struct ServiceSession * client_session;
1832 struct ServiceSession * curr;
1834 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1835 _ ("Peer disconnected, terminating session %s with peer (%s)\n"),
1836 GNUNET_h2s (&session->key),
1837 GNUNET_i2s (&session->peer));
1838 if (ALICE == session->role) {
1839 // as we have only one peer connected in each session, just remove the session
1841 if ((SERVICE_RESPONSE_RECEIVED > session->state) && (!do_shutdown)) {
1842 session->channel = NULL;
1843 // if this happened before we received the answer, we must terminate the session
1844 session->client_notification_task =
1845 GNUNET_SCHEDULER_add_now (&prepare_client_end_notification,
1849 else { //(BOB == session->role) service session
1850 // remove the session, unless it has already been dequeued, but somehow still active
1851 // this could bug without the IF in case the queue is empty and the service session was the only one know to the service
1852 // scenario: disconnect before alice can send her message to bob.
1853 for (curr = from_service_head; NULL != curr; curr = curr->next)
1854 if (curr == session) {
1855 GNUNET_CONTAINER_DLL_remove (from_service_head, from_service_tail, curr);
1858 // there is a client waiting for this service session, terminate it, too!
1859 // i assume the tupel of key and element count is unique. if it was not the rest of the code would not work either.
1860 client_session = find_matching_session (from_client_tail,
1864 free_session_variables (session);
1865 GNUNET_free (session);
1867 // the client has to check if it was waiting for a result
1868 // or if it was a responder, no point in adding more statefulness
1869 if (client_session && (!do_shutdown)) {
1870 client_session->state = FINALIZED;
1871 client_session->client_notification_task =
1872 GNUNET_SCHEDULER_add_now (&prepare_client_end_notification,
1880 * Compute our scalar product, done by Alice
1882 * @param session - the session associated with this computation
1883 * @return product as MPI, never NULL
1886 compute_scalar_product (struct ServiceSession * session)
1897 count = session->used;
1898 // due to the introduced static offset S, we now also have to remove this
1899 // from the E(a_pi)(+)E(-b_pi-r_pi) and E(a_qi)(+)E(-r_qi) twice each,
1900 // the result is E((S + a_pi) + (S -b_pi-r_pi)) and E(S + a_qi + S - r_qi)
1901 for (i = 0; i < count; i++)
1903 decrypt_element (session->r[i], session->r[i], my_mu, my_lambda, my_n, my_nsquare);
1904 gcry_mpi_sub (session->r[i], session->r[i], my_offset);
1905 gcry_mpi_sub (session->r[i], session->r[i], my_offset);
1906 decrypt_element (session->r_prime[i], session->r_prime[i], my_mu, my_lambda, my_n, my_nsquare);
1907 gcry_mpi_sub (session->r_prime[i], session->r_prime[i], my_offset);
1908 gcry_mpi_sub (session->r_prime[i], session->r_prime[i], my_offset);
1911 // calculate t = sum(ai)
1912 t = compute_square_sum (session->a, count);
1915 u = gcry_mpi_new (0);
1916 tmp = compute_square_sum (session->r, count);
1917 gcry_mpi_sub (u, u, tmp);
1918 gcry_mpi_release (tmp);
1921 u_prime = gcry_mpi_new (0);
1922 tmp = compute_square_sum (session->r_prime, count);
1923 gcry_mpi_sub (u_prime, u_prime, tmp);
1925 GNUNET_assert (p = gcry_mpi_new (0));
1926 GNUNET_assert (p_prime = gcry_mpi_new (0));
1929 decrypt_element (session->s, session->s, my_mu, my_lambda, my_n, my_nsquare);
1930 decrypt_element (session->s_prime, session->s_prime, my_mu, my_lambda, my_n, my_nsquare);
1933 gcry_mpi_add (p, session->s, t);
1934 gcry_mpi_add (p, p, u);
1937 gcry_mpi_add (p_prime, session->s_prime, t);
1938 gcry_mpi_add (p_prime, p_prime, u_prime);
1940 gcry_mpi_release (t);
1941 gcry_mpi_release (u);
1942 gcry_mpi_release (u_prime);
1945 gcry_mpi_sub (p, p, p_prime);
1946 gcry_mpi_release (p_prime);
1947 tmp = gcry_mpi_set_ui (tmp, 2);
1948 gcry_mpi_div (p, NULL, p, tmp, 0);
1950 gcry_mpi_release (tmp);
1951 for (i = 0; i < count; i++)
1952 gcry_mpi_release (session->a[i]);
1953 GNUNET_free (session->a);
1961 * Handle a multipart-chunk of a request from another service to calculate a scalarproduct with us.
1963 * @param cls closure (set from #GNUNET_MESH_connect)
1964 * @param channel connection to the other end
1965 * @param channel_ctx place to store local state associated with the channel
1966 * @param message the actual message
1967 * @return #GNUNET_OK to keep the connection open,
1968 * #GNUNET_SYSERR to close it (signal serious error)
1971 handle_service_request_multipart (void *cls,
1972 struct GNUNET_MESH_Channel * channel,
1974 const struct GNUNET_MessageHeader * message)
1976 struct ServiceSession * session;
1977 const struct GNUNET_SCALARPRODUCT_multipart_message * msg = (const struct GNUNET_SCALARPRODUCT_multipart_message *) message;
1978 uint32_t used_elements;
1979 uint32_t contained_elements = 0;
1980 uint32_t msg_length;
1981 unsigned char * current;
1985 // are we in the correct state?
1986 session = (struct ServiceSession *) * channel_ctx;
1987 if ((BOB != session->role) || (WAITING_FOR_MULTIPART_TRANSMISSION != session->state)) {
1990 // shorter than minimum?
1991 if (ntohs (msg->header.size) <= sizeof (struct GNUNET_SCALARPRODUCT_multipart_message)) {
1994 used_elements = session->used;
1995 contained_elements = ntohl (msg->multipart_element_count);
1996 msg_length = sizeof (struct GNUNET_SCALARPRODUCT_multipart_message)
1997 +contained_elements * PAILLIER_ELEMENT_LENGTH;
1999 if ((ntohs (msg->header.size) != msg_length)
2000 || (used_elements < contained_elements + session->transferred)) {
2003 current = (unsigned char *) &msg[1];
2004 if (contained_elements != 0) {
2005 // Convert each vector element to MPI_value
2006 for (i = session->transferred; i < session->transferred + contained_elements; i++) {
2008 if (0 != (rc = gcry_mpi_scan (&session->a[i],
2010 ¤t[i * PAILLIER_ELEMENT_LENGTH],
2011 PAILLIER_ELEMENT_LENGTH,
2013 LOG_GCRY (GNUNET_ERROR_TYPE_DEBUG, "gcry_mpi_scan", rc);
2017 session->transferred += contained_elements;
2019 if (session->transferred == used_elements)
2021 // single part finished
2022 session->state = SERVICE_REQUEST_RECEIVED;
2023 if (session->response)
2025 GNUNET_log (GNUNET_ERROR_TYPE_INFO,
2026 _ ("Got session with key %s and a matching element set, processing.\n"),
2027 GNUNET_h2s (&session->key));
2028 if (GNUNET_OK != compute_service_response (session, session->response)) {
2029 //something went wrong, remove it again...
2034 GNUNET_log (GNUNET_ERROR_TYPE_INFO,
2035 _("Got session with key %s without a matching element set, queueing.\n"),
2036 GNUNET_h2s (&session->key));
2040 // multipart message
2046 // and notify our client-session that we could not complete the session
2047 GNUNET_CONTAINER_DLL_remove (from_service_head, from_service_tail, session);
2048 if (session->response)
2049 // we just found the responder session in this queue
2050 session->response->client_notification_task =
2051 GNUNET_SCHEDULER_add_now (&prepare_client_end_notification,
2053 free_session_variables (session);
2054 GNUNET_free (session);
2055 return GNUNET_SYSERR;
2060 * Handle a request from another service to calculate a scalarproduct with us.
2062 * @param cls closure (set from #GNUNET_MESH_connect)
2063 * @param channel connection to the other end
2064 * @param channel_ctx place to store local state associated with the channel
2065 * @param message the actual message
2066 * @return #GNUNET_OK to keep the connection open,
2067 * #GNUNET_SYSERR to close it (signal serious error)
2070 handle_service_request (void *cls,
2071 struct GNUNET_MESH_Channel * channel,
2073 const struct GNUNET_MessageHeader * message)
2075 struct ServiceSession * session;
2076 const struct GNUNET_SCALARPRODUCT_service_request * msg = (const struct GNUNET_SCALARPRODUCT_service_request *) message;
2077 uint32_t mask_length;
2079 uint32_t used_elements;
2080 uint32_t contained_elements = 0;
2081 uint32_t element_count;
2082 uint32_t msg_length;
2083 unsigned char * current;
2086 enum SessionState needed_state;
2088 session = (struct ServiceSession *) * channel_ctx;
2089 if (WAITING_FOR_SERVICE_REQUEST != session->state) {
2092 // Check if message was sent by me, which would be bad!
2093 if (!memcmp (&session->peer, &me, sizeof (struct GNUNET_PeerIdentity))) {
2094 GNUNET_free (session);
2096 return GNUNET_SYSERR;
2098 // shorter than expected?
2099 if (ntohs (msg->header.size) < sizeof (struct GNUNET_SCALARPRODUCT_service_request)) {
2100 GNUNET_free (session);
2101 GNUNET_break_op (0);
2102 return GNUNET_SYSERR;
2104 mask_length = ntohl (msg->mask_length);
2105 pk_length = ntohl (msg->pk_length);
2106 used_elements = ntohl (msg->total_element_count);
2107 contained_elements = ntohl (msg->contained_element_count);
2108 element_count = ntohl (msg->element_count);
2109 msg_length = sizeof (struct GNUNET_SCALARPRODUCT_service_request)
2110 +mask_length + pk_length + contained_elements * PAILLIER_ELEMENT_LENGTH;
2112 //sanity check: is the message as long as the message_count fields suggests?
2113 if ( (ntohs (msg->header.size) != msg_length) ||
2114 (element_count < used_elements) ||
2115 (used_elements < contained_elements) ||
2116 (0 == used_elements) ||
2117 (mask_length != (element_count / 8 + ((element_count % 8) ? 1 : 0))) )
2119 GNUNET_free (session);
2120 GNUNET_break_op (0);
2121 return GNUNET_SYSERR;
2123 if (find_matching_session (from_service_tail,
2129 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
2130 _ ("Got message with duplicate session key (`%s'), ignoring service request.\n"),
2131 (const char *) &(msg->key));
2132 GNUNET_free (session);
2133 return GNUNET_SYSERR;
2136 session->total = element_count;
2137 session->used = used_elements;
2138 session->transferred = contained_elements;
2139 session->channel = channel;
2142 memcpy (&session->key, &msg->key, sizeof (struct GNUNET_HashCode));
2143 current = (unsigned char *) &msg[1];
2144 //preserve the mask, we will need that later on
2145 session->mask = GNUNET_malloc (mask_length);
2146 memcpy (session->mask, current, mask_length);
2148 current += mask_length;
2150 //convert the publickey to sexp
2151 if (0 != (rc = gcry_sexp_new (&session->remote_pubkey, current, pk_length, 1))) {
2152 LOG_GCRY (GNUNET_ERROR_TYPE_DEBUG, "gcry_sexp_new", rc);
2153 GNUNET_free (session->mask);
2154 GNUNET_free (session);
2155 return GNUNET_SYSERR;
2157 current += pk_length;
2158 //check if service queue contains a matching request
2159 needed_state = CLIENT_RESPONSE_RECEIVED;
2160 session->response = find_matching_session (from_client_tail,
2163 &needed_state, NULL);
2165 session->a = GNUNET_malloc (sizeof (gcry_mpi_t) * used_elements);
2166 session->state = WAITING_FOR_MULTIPART_TRANSMISSION;
2167 GNUNET_CONTAINER_DLL_insert (from_service_head, from_service_tail, session);
2168 if (contained_elements != 0) {
2169 // Convert each vector element to MPI_value
2170 for (i = 0; i < contained_elements; i++) {
2172 if (0 != (rc = gcry_mpi_scan (&session->a[i],
2174 ¤t[i * PAILLIER_ELEMENT_LENGTH],
2175 PAILLIER_ELEMENT_LENGTH,
2177 LOG_GCRY (GNUNET_ERROR_TYPE_DEBUG, "gcry_mpi_scan", rc);
2181 if (contained_elements == used_elements) {
2182 // single part finished
2183 session->state = SERVICE_REQUEST_RECEIVED;
2184 if (session->response) {
2185 GNUNET_log (GNUNET_ERROR_TYPE_INFO, _ ("Got session with key %s and a matching element set, processing.\n"), GNUNET_h2s (&session->key));
2186 if (GNUNET_OK != compute_service_response (session, session->response)) {
2187 //something went wrong, remove it again...
2192 GNUNET_log (GNUNET_ERROR_TYPE_INFO, _ ("Got session with key %s without a matching element set, queueing.\n"), GNUNET_h2s (&session->key));
2195 // multipart message
2200 GNUNET_break_op (0);
2201 if ((NULL != session->next) || (NULL != session->prev) || (from_service_head == session))
2202 GNUNET_CONTAINER_DLL_remove (from_service_head, from_service_tail, session);
2203 // and notify our client-session that we could not complete the session
2204 if (session->response)
2205 // we just found the responder session in this queue
2206 session->response->client_notification_task =
2207 GNUNET_SCHEDULER_add_now (&prepare_client_end_notification,
2209 free_session_variables (session);
2210 return GNUNET_SYSERR;
2215 * Handle a multipart chunk of a response we got from another service we wanted to calculate a scalarproduct with.
2217 * @param cls closure (set from #GNUNET_MESH_connect)
2218 * @param channel connection to the other end
2219 * @param channel_ctx place to store local state associated with the channel
2220 * @param message the actual message
2221 * @return #GNUNET_OK to keep the connection open,
2222 * #GNUNET_SYSERR to close it (signal serious error)
2225 handle_service_response_multipart (void *cls,
2226 struct GNUNET_MESH_Channel * channel,
2228 const struct GNUNET_MessageHeader * message)
2230 struct ServiceSession * session;
2231 const struct GNUNET_SCALARPRODUCT_multipart_message * msg = (const struct GNUNET_SCALARPRODUCT_multipart_message *) message;
2232 unsigned char * current;
2235 uint32_t contained = 0;
2237 size_t required_size;
2240 GNUNET_assert (NULL != message);
2241 // are we in the correct state?
2242 session = (struct ServiceSession *) * channel_ctx;
2243 if ((ALICE != session->role) || (WAITING_FOR_MULTIPART_TRANSMISSION != session->state)) {
2246 msg_size = ntohs (msg->header.size);
2247 required_size = sizeof (struct GNUNET_SCALARPRODUCT_multipart_message) + 2 * PAILLIER_ELEMENT_LENGTH;
2248 // shorter than minimum?
2249 if (required_size > msg_size) {
2252 contained = ntohl (msg->multipart_element_count);
2253 required_size = sizeof (struct GNUNET_SCALARPRODUCT_multipart_message)
2254 + 2 * contained * PAILLIER_ELEMENT_LENGTH;
2255 //sanity check: is the message as long as the message_count fields suggests?
2256 if ((required_size != msg_size) || (session->used < session->transferred + contained)) {
2259 current = (unsigned char *) &msg[1];
2260 // Convert each k[][perm] to its MPI_value
2261 for (i = 0; i < contained; i++) {
2262 if (0 != (rc = gcry_mpi_scan (&session->r[i], GCRYMPI_FMT_USG, current,
2263 PAILLIER_ELEMENT_LENGTH, &read))) {
2264 LOG_GCRY (GNUNET_ERROR_TYPE_DEBUG, "gcry_mpi_scan", rc);
2267 current += PAILLIER_ELEMENT_LENGTH;
2268 if (0 != (rc = gcry_mpi_scan (&session->r_prime[i], GCRYMPI_FMT_USG, current,
2269 PAILLIER_ELEMENT_LENGTH, &read))) {
2270 LOG_GCRY (GNUNET_ERROR_TYPE_DEBUG, "gcry_mpi_scan", rc);
2273 current += PAILLIER_ELEMENT_LENGTH;
2275 session->transferred += contained;
2276 if (session->transferred != session->used)
2278 session->state = SERVICE_RESPONSE_RECEIVED;
2279 session->product = compute_scalar_product (session); //never NULL
2282 GNUNET_break_op (NULL != session->product);
2284 // send message with product to client
2285 if (ALICE == session->role){
2286 session->state = FINALIZED;
2287 session->channel = NULL;
2288 session->client_notification_task =
2289 GNUNET_SCHEDULER_add_now (&prepare_client_response,
2292 // the channel has done its job, terminate our connection and the channel
2293 // the peer will be notified that the channel was destroyed via channel_destruction_handler
2294 // just close the connection, as recommended by Christian
2295 return GNUNET_SYSERR;
2300 * Handle a response we got from another service we wanted to calculate a scalarproduct with.
2302 * @param cls closure (set from #GNUNET_MESH_connect)
2303 * @param channel connection to the other end
2304 * @param channel_ctx place to store local state associated with the channel
2305 * @param message the actual message
2306 * @return #GNUNET_OK to keep the connection open,
2307 * #GNUNET_SYSERR to close it (we are done)
2310 handle_service_response (void *cls,
2311 struct GNUNET_MESH_Channel * channel,
2313 const struct GNUNET_MessageHeader * message)
2315 struct ServiceSession * session;
2316 const struct GNUNET_SCALARPRODUCT_service_response * msg = (const struct GNUNET_SCALARPRODUCT_service_response *) message;
2317 unsigned char * current;
2320 uint32_t contained = 0;
2322 size_t required_size;
2325 GNUNET_assert (NULL != message);
2326 session = (struct ServiceSession *) * channel_ctx;
2327 // are we in the correct state?
2328 if (WAITING_FOR_SERVICE_RESPONSE != session->state) {
2331 //we need at least a full message without elements attached
2332 msg_size = ntohs (msg->header.size);
2333 required_size = sizeof (struct GNUNET_SCALARPRODUCT_service_response) + 2 * PAILLIER_ELEMENT_LENGTH;
2335 if (required_size > msg_size) {
2338 contained = ntohl (msg->contained_element_count);
2339 required_size = sizeof (struct GNUNET_SCALARPRODUCT_service_response)
2340 + 2 * contained * PAILLIER_ELEMENT_LENGTH
2341 + 2 * PAILLIER_ELEMENT_LENGTH;
2342 //sanity check: is the message as long as the message_count fields suggests?
2343 if ((msg_size != required_size) || (session->used < contained)) {
2346 session->state = WAITING_FOR_MULTIPART_TRANSMISSION;
2347 session->transferred = contained;
2349 current = (unsigned char *) &msg[1];
2350 if (0 != (rc = gcry_mpi_scan (&session->s, GCRYMPI_FMT_USG, current,
2351 PAILLIER_ELEMENT_LENGTH, &read))) {
2352 LOG_GCRY (GNUNET_ERROR_TYPE_DEBUG, "gcry_mpi_scan", rc);
2355 current += PAILLIER_ELEMENT_LENGTH;
2357 if (0 != (rc = gcry_mpi_scan (&session->s_prime, GCRYMPI_FMT_USG, current,
2358 PAILLIER_ELEMENT_LENGTH, &read))) {
2359 LOG_GCRY (GNUNET_ERROR_TYPE_DEBUG, "gcry_mpi_scan", rc);
2362 current += PAILLIER_ELEMENT_LENGTH;
2363 session->r = GNUNET_malloc (sizeof (gcry_mpi_t) * session->used);
2364 session->r_prime = GNUNET_malloc (sizeof (gcry_mpi_t) * session->used);
2365 // Convert each k[][perm] to its MPI_value
2366 for (i = 0; i < contained; i++) {
2367 if (0 != (rc = gcry_mpi_scan (&session->r[i], GCRYMPI_FMT_USG, current,
2368 PAILLIER_ELEMENT_LENGTH, &read))) {
2369 LOG_GCRY (GNUNET_ERROR_TYPE_DEBUG, "gcry_mpi_scan", rc);
2372 current += PAILLIER_ELEMENT_LENGTH;
2373 if (0 != (rc = gcry_mpi_scan (&session->r_prime[i], GCRYMPI_FMT_USG, current,
2374 PAILLIER_ELEMENT_LENGTH, &read))) {
2375 LOG_GCRY (GNUNET_ERROR_TYPE_DEBUG, "gcry_mpi_scan", rc);
2378 current += PAILLIER_ELEMENT_LENGTH;
2380 if (session->transferred != session->used)
2381 return GNUNET_OK; //wait for the other multipart chunks
2383 session->state = SERVICE_RESPONSE_RECEIVED;
2384 session->product = compute_scalar_product (session); //never NULL
2387 GNUNET_break_op (NULL != session->product);
2388 // send message with product to client
2389 if (ALICE == session->role){
2390 session->state = FINALIZED;
2391 session->channel = NULL;
2392 session->client_notification_task =
2393 GNUNET_SCHEDULER_add_now (&prepare_client_response,
2396 // the channel has done its job, terminate our connection and the channel
2397 // the peer will be notified that the channel was destroyed via channel_destruction_handler
2398 // just close the connection, as recommended by Christian
2399 return GNUNET_SYSERR;
2404 * Task run during shutdown.
2410 shutdown_task (void *cls,
2411 const struct GNUNET_SCHEDULER_TaskContext *tc)
2413 struct ServiceSession * session;
2414 GNUNET_log (GNUNET_ERROR_TYPE_INFO, _ ("Shutting down, initiating cleanup.\n"));
2416 do_shutdown = GNUNET_YES;
2418 // terminate all owned open channels.
2419 for (session = from_client_head; NULL != session; session = session->next) {
2420 if ((FINALIZED != session->state) && (NULL != session->channel)) {
2421 GNUNET_MESH_channel_destroy (session->channel);
2422 session->channel = NULL;
2424 if (GNUNET_SCHEDULER_NO_TASK != session->client_notification_task) {
2425 GNUNET_SCHEDULER_cancel (session->client_notification_task);
2426 session->client_notification_task = GNUNET_SCHEDULER_NO_TASK;
2428 if (GNUNET_SCHEDULER_NO_TASK != session->service_request_task) {
2429 GNUNET_SCHEDULER_cancel (session->service_request_task);
2430 session->service_request_task = GNUNET_SCHEDULER_NO_TASK;
2432 if (NULL != session->client) {
2433 GNUNET_SERVER_client_disconnect (session->client);
2434 session->client = NULL;
2437 for (session = from_service_head; NULL != session; session = session->next)
2438 if (NULL != session->channel) {
2439 GNUNET_MESH_channel_destroy (session->channel);
2440 session->channel = NULL;
2444 GNUNET_MESH_disconnect (my_mesh);
2451 * Initialization of the program and message handlers
2453 * @param cls closure
2454 * @param server the initialized server
2455 * @param c configuration to use
2459 struct GNUNET_SERVER_Handle *server,
2460 const struct GNUNET_CONFIGURATION_Handle *c)
2462 static const struct GNUNET_SERVER_MessageHandler server_handlers[] = {
2463 {&handle_client_request, NULL, GNUNET_MESSAGE_TYPE_SCALARPRODUCT_CLIENT_TO_ALICE, 0},
2464 {&handle_client_request, NULL, GNUNET_MESSAGE_TYPE_SCALARPRODUCT_CLIENT_TO_BOB, 0},
2467 static const struct GNUNET_MESH_MessageHandler mesh_handlers[] = {
2468 { &handle_service_request, GNUNET_MESSAGE_TYPE_SCALARPRODUCT_ALICE_TO_BOB, 0},
2469 { &handle_service_request_multipart, GNUNET_MESSAGE_TYPE_SCALARPRODUCT_ALICE_TO_BOB_MULTIPART, 0},
2470 { &handle_service_response, GNUNET_MESSAGE_TYPE_SCALARPRODUCT_BOB_TO_ALICE, 0},
2471 { &handle_service_response_multipart, GNUNET_MESSAGE_TYPE_SCALARPRODUCT_BOB_TO_ALICE_MULTIPART, 0},
2474 static const uint32_t ports[] = {
2475 GNUNET_APPLICATION_TYPE_SCALARPRODUCT,
2478 //generate private/public key set
2479 GNUNET_log (GNUNET_ERROR_TYPE_INFO, _ ("Generating Paillier-Keyset.\n"));
2481 // register server callbacks and disconnect handler
2482 GNUNET_SERVER_add_handlers (server, server_handlers);
2483 GNUNET_SERVER_disconnect_notify (server,
2484 &handle_client_disconnect,
2486 GNUNET_break (GNUNET_OK ==
2487 GNUNET_CRYPTO_get_peer_identity (c,
2489 my_mesh = GNUNET_MESH_connect (c, NULL,
2490 &channel_incoming_handler,
2491 &channel_destruction_handler,
2492 mesh_handlers, ports);
2494 GNUNET_log (GNUNET_ERROR_TYPE_ERROR, _ ("Connect to MESH failed\n"));
2495 GNUNET_SCHEDULER_shutdown ();
2498 GNUNET_log (GNUNET_ERROR_TYPE_INFO, _ ("Mesh initialized\n"));
2499 GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_FOREVER_REL,
2506 * The main function for the scalarproduct service.
2508 * @param argc number of arguments from the command line
2509 * @param argv command line arguments
2510 * @return 0 ok, 1 on error
2513 main (int argc, char *const *argv)
2515 return (GNUNET_OK ==
2516 GNUNET_SERVICE_run (argc, argv,
2518 GNUNET_SERVICE_OPTION_NONE,
2519 &run, NULL)) ? 0 : 1;
2522 /* end of gnunet-service-scalarproduct.c */