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);
712 GNUNET_free_non_null (session->mask);
714 for (i = 0; i < session->used; i++)
715 if (session->r[i]) gcry_mpi_release (session->r[i]);
716 GNUNET_free (session->r);
719 if (session->r_prime) {
720 for (i = 0; i < session->used; i++)
721 if (session->r_prime[i]) gcry_mpi_release (session->r_prime[i]);
722 GNUNET_free (session->r_prime);
723 session->r_prime = NULL;
726 gcry_mpi_release (session->s);
730 if (session->s_prime){
731 gcry_mpi_release (session->s_prime);
732 session->s_prime = NULL;
735 if (session->product){
736 gcry_mpi_release (session->product);
737 session->product = NULL;
740 if (session->remote_pubkey){
741 gcry_sexp_release (session->remote_pubkey);
742 session->remote_pubkey = NULL;
745 if (session->vector) {
746 GNUNET_free_non_null (session->vector);
750 ///////////////////////////////////////////////////////////////////////////////
751 // Event and Message Handlers
752 ///////////////////////////////////////////////////////////////////////////////
756 * A client disconnected.
758 * Remove the associated session(s), release data structures
759 * and cancel pending outgoing transmissions to the client.
760 * if the session has not yet completed, we also cancel Alice's request to Bob.
762 * @param cls closure, NULL
763 * @param client identification of the client
766 handle_client_disconnect (void *cls,
767 struct GNUNET_SERVER_Client *client)
769 struct ServiceSession *session;
772 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
773 _ ("Client (%p) disconnected from us.\n"), client);
777 session = GNUNET_SERVER_client_get_user_context (client, struct ServiceSession);
780 GNUNET_CONTAINER_DLL_remove (from_client_head, from_client_tail, session);
782 if (!(session->role == BOB && session->state == FINALIZED)) {
783 //we MUST terminate any client message underway
784 if (session->service_transmit_handle && session->tunnel)
785 GNUNET_MESH_notify_transmit_ready_cancel (session->service_transmit_handle);
786 if (session->tunnel && session->state == WAITING_FOR_SERVICE_RESPONSE)
787 GNUNET_MESH_tunnel_destroy (session->tunnel);
789 if (GNUNET_SCHEDULER_NO_TASK != session->client_notification_task) {
790 GNUNET_SCHEDULER_cancel (session->client_notification_task);
791 session->client_notification_task = GNUNET_SCHEDULER_NO_TASK;
793 if (GNUNET_SCHEDULER_NO_TASK != session->service_request_task) {
794 GNUNET_SCHEDULER_cancel (session->service_request_task);
795 session->service_request_task = GNUNET_SCHEDULER_NO_TASK;
797 if (NULL != session->client_transmit_handle) {
798 GNUNET_SERVER_notify_transmit_ready_cancel (session->client_transmit_handle);
799 session->client_transmit_handle = NULL;
801 free_session_variables (session);
802 GNUNET_free (session);
807 * Notify the client that the session has succeeded or failed completely.
808 * This message gets sent to
809 * * alice's client if bob disconnected or to
810 * * bob's client if the operation completed or alice disconnected
812 * @param cls the associated client session
813 * @param tc the task context handed to us by the scheduler, unused
816 prepare_client_end_notification (void * cls,
817 const struct GNUNET_SCHEDULER_TaskContext * tc)
819 struct ServiceSession * session = cls;
820 struct GNUNET_SCALARPRODUCT_client_response * msg;
822 session->client_notification_task = GNUNET_SCHEDULER_NO_TASK;
824 msg = GNUNET_new (struct GNUNET_SCALARPRODUCT_client_response);
825 msg->header.type = htons (GNUNET_MESSAGE_TYPE_SCALARPRODUCT_SERVICE_TO_CLIENT);
826 memcpy (&msg->key, &session->key, sizeof (struct GNUNET_HashCode));
827 memcpy (&msg->peer, &session->peer, sizeof ( struct GNUNET_PeerIdentity));
828 msg->header.size = htons (sizeof (struct GNUNET_SCALARPRODUCT_client_response));
829 // signal error if not signalized, positive result-range field but zero length.
830 msg->product_length = htonl (0);
831 msg->range = (session->state == FINALIZED) ? 0 : -1;
833 session->msg = &msg->header;
835 //transmit this message to our client
836 session->client_transmit_handle =
837 GNUNET_SERVER_notify_transmit_ready (session->client,
838 sizeof (struct GNUNET_SCALARPRODUCT_client_response),
839 GNUNET_TIME_UNIT_FOREVER_REL,
843 // if we could not even queue our request, something is wrong
844 if (NULL == session->client_transmit_handle) {
845 GNUNET_log (GNUNET_ERROR_TYPE_WARNING, _ ("Could not send message to client (%p)!\n"), session->client);
846 // usually gets freed by do_send_message
851 GNUNET_log (GNUNET_ERROR_TYPE_INFO, _ ("Sending session-end notification to client (%p) for session %s\n"), &session->client, GNUNET_h2s (&session->key));
857 * prepare the response we will send to alice or bobs' clients.
858 * in Bobs case the product will be NULL.
860 * @param cls the session associated with our client.
861 * @param tc the task context handed to us by the scheduler, unused
864 prepare_client_response (void *cls,
865 const struct GNUNET_SCHEDULER_TaskContext *tc)
867 struct ServiceSession * session = cls;
868 struct GNUNET_SCALARPRODUCT_client_response * msg;
869 unsigned char * product_exported = NULL;
870 size_t product_length = 0;
871 uint32_t msg_length = 0;
876 session->client_notification_task = GNUNET_SCHEDULER_NO_TASK;
878 if (session->product) {
879 gcry_mpi_t value = gcry_mpi_new (0);
881 sign = gcry_mpi_cmp_ui (session->product, 0);
882 // libgcrypt can not handle a print of a negative number
883 // if (a->sign) return gcry_error (GPG_ERR_INTERNAL); /* Can't handle it yet. */
885 gcry_mpi_sub (value, value, session->product);
889 gcry_mpi_add (value, value, session->product);
894 gcry_mpi_release (session->product);
895 session->product = NULL;
897 // get representation as string
899 && (0 != (rc = gcry_mpi_aprint (GCRYMPI_FMT_STD,
903 LOG_GCRY (GNUNET_ERROR_TYPE_ERROR, "gcry_mpi_scan", rc);
905 range = -1; // signal error with product-length = 0 and range = -1
907 gcry_mpi_release (value);
910 msg_length = sizeof (struct GNUNET_SCALARPRODUCT_client_response) +product_length;
911 msg = GNUNET_malloc (msg_length);
912 memcpy (&msg->key, &session->key, sizeof (struct GNUNET_HashCode));
913 memcpy (&msg->peer, &session->peer, sizeof ( struct GNUNET_PeerIdentity));
914 if (product_exported != NULL) {
915 memcpy (&msg[1], product_exported, product_length);
916 GNUNET_free (product_exported);
918 msg->header.type = htons (GNUNET_MESSAGE_TYPE_SCALARPRODUCT_SERVICE_TO_CLIENT);
919 msg->header.size = htons (msg_length);
921 msg->product_length = htonl (product_length);
923 session->msg = (struct GNUNET_MessageHeader *) msg;
924 //transmit this message to our client
925 session->client_transmit_handle =
926 GNUNET_SERVER_notify_transmit_ready (session->client,
928 GNUNET_TIME_UNIT_FOREVER_REL,
931 if (NULL == session->client_transmit_handle) {
932 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
933 _ ("Could not send message to client (%p)!\n"),
935 session->client = NULL;
936 // callback was not called!
941 // gracefully sent message, just terminate session structure
942 GNUNET_log (GNUNET_ERROR_TYPE_INFO,
943 _ ("Sent result to client (%p), this session (%s) has ended!\n"),
945 GNUNET_h2s (&session->key));
950 * Send a multipart chunk of a service response from bob to alice.
951 * This element only contains the two permutations of R, R'.
953 * @param cls the associated service session
956 prepare_service_response_multipart (void *cls)
958 struct ServiceSession * session = cls;
959 unsigned char * current;
960 unsigned char * element_exported;
961 struct GNUNET_SCALARPRODUCT_multipart_message * msg;
965 size_t element_length = 0; // initialized by gcry_mpi_print, but the compiler doesn't know that
967 msg_length = sizeof (struct GNUNET_SCALARPRODUCT_multipart_message);
968 todo_count = session->used - session->transferred;
970 if (todo_count > MULTIPART_ELEMENT_CAPACITY / 2)
971 // send the currently possible maximum chunk, we always transfer both permutations
972 todo_count = MULTIPART_ELEMENT_CAPACITY / 2;
974 msg_length += todo_count * PAILLIER_ELEMENT_LENGTH * 2;
975 msg = GNUNET_malloc (msg_length);
976 msg->header.type = htons (GNUNET_MESSAGE_TYPE_SCALARPRODUCT_ALICE_TO_BOB_MULTIPART);
977 msg->header.size = htons (msg_length);
978 msg->multipart_element_count = htonl (todo_count);
980 element_exported = GNUNET_malloc (PAILLIER_ELEMENT_LENGTH);
981 current = (unsigned char *) &msg[1];
983 for (i = session->transferred; i < session->transferred + todo_count; i++) {
985 memset (element_exported, 0, PAILLIER_ELEMENT_LENGTH);
986 GNUNET_assert (0 == gcry_mpi_print (GCRYMPI_FMT_USG,
987 element_exported, PAILLIER_ELEMENT_LENGTH,
990 adjust (element_exported, element_length, PAILLIER_ELEMENT_LENGTH);
991 memcpy (current, element_exported, PAILLIER_ELEMENT_LENGTH);
992 current += PAILLIER_ELEMENT_LENGTH;
994 memset (element_exported, 0, PAILLIER_ELEMENT_LENGTH);
995 GNUNET_assert (0 == gcry_mpi_print (GCRYMPI_FMT_USG,
996 element_exported, PAILLIER_ELEMENT_LENGTH,
998 session->r_prime[i]));
999 adjust (element_exported, element_length, PAILLIER_ELEMENT_LENGTH);
1000 memcpy (current, element_exported, PAILLIER_ELEMENT_LENGTH);
1001 current += PAILLIER_ELEMENT_LENGTH;
1003 GNUNET_free (element_exported);
1004 for (i = session->transferred; i < session->transferred; i++) {
1005 gcry_mpi_release (session->r_prime[i]);
1006 gcry_mpi_release (session->r[i]);
1008 session->transferred += todo_count;
1009 session->msg = (struct GNUNET_MessageHeader *) msg;
1010 session->service_transmit_handle =
1011 GNUNET_MESH_notify_transmit_ready (session->tunnel,
1013 GNUNET_TIME_UNIT_FOREVER_REL,
1017 //disconnect our client
1018 if (NULL == session->service_transmit_handle) {
1019 GNUNET_log (GNUNET_ERROR_TYPE_ERROR, _ ("Could not send service-response message via mesh!)\n"));
1020 session->state = FINALIZED;
1022 session->response->client_notification_task =
1023 GNUNET_SCHEDULER_add_now (&prepare_client_end_notification,
1027 if (session->transferred != session->used)
1029 session->state = WAITING_FOR_MULTIPART_TRANSMISSION;
1032 session->state = FINALIZED;
1033 GNUNET_free(session->r);
1034 GNUNET_free(session->r_prime);
1035 session->r_prime = NULL;
1043 * generates the response message to be sent to alice after computing
1044 * the values (1), (2), S and S'
1045 * (1)[]: $E_A(a_{pi(i)}) times E_A(- r_{pi(i)} - b_{pi(i)}) &= E_A(a_{pi(i)} - r_{pi(i)} - b_{pi(i)})$
1046 * (2)[]: $E_A(a_{pi'(i)}) times E_A(- r_{pi'(i)}) &= E_A(a_{pi'(i)} - r_{pi'(i)})$
1047 * S: $S := E_A(sum (r_i + b_i)^2)$
1048 * S': $S' := E_A(sum r_i^2)$
1050 * @param s S: $S := E_A(sum (r_i + b_i)^2)$
1051 * @param s_prime S': $S' := E_A(sum r_i^2)$
1052 * @param session the associated requesting session with alice
1053 * @return #GNUNET_NO if we could not send our message
1054 * #GNUNET_OK if the operation succeeded
1057 prepare_service_response (gcry_mpi_t s,
1059 struct ServiceSession * session)
1061 struct GNUNET_SCALARPRODUCT_service_response * msg;
1062 uint32_t msg_length = 0;
1063 unsigned char * current = NULL;
1064 unsigned char * element_exported = NULL;
1065 size_t element_length = 0;
1068 msg_length = sizeof (struct GNUNET_SCALARPRODUCT_service_response)
1069 + 2 * PAILLIER_ELEMENT_LENGTH; // s, stick
1071 if (GNUNET_SERVER_MAX_MESSAGE_SIZE > msg_length + 2 * session->used * PAILLIER_ELEMENT_LENGTH) { //kp, kq
1072 msg_length += +2 * session->used * PAILLIER_ELEMENT_LENGTH;
1073 session->transferred = session->used;
1076 session->transferred = (GNUNET_SERVER_MAX_MESSAGE_SIZE - 1 - msg_length) / (PAILLIER_ELEMENT_LENGTH * 2);
1079 msg = GNUNET_malloc (msg_length);
1081 msg->header.type = htons (GNUNET_MESSAGE_TYPE_SCALARPRODUCT_BOB_TO_ALICE);
1082 msg->header.size = htons (msg_length);
1083 msg->total_element_count = htonl (session->total);
1084 msg->used_element_count = htonl (session->used);
1085 msg->contained_element_count = htonl (session->transferred);
1086 memcpy (&msg->key, &session->key, sizeof (struct GNUNET_HashCode));
1087 current = (unsigned char *) &msg[1];
1089 element_exported = GNUNET_malloc (PAILLIER_ELEMENT_LENGTH);
1090 // 4 times the same logics with slight variations.
1091 // doesn't really justify having 2 functions for that
1092 // so i put it into blocks to enhance readability
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;
1104 memset (element_exported, 0, PAILLIER_ELEMENT_LENGTH);
1105 GNUNET_assert (0 == gcry_mpi_print (GCRYMPI_FMT_USG,
1106 element_exported, PAILLIER_ELEMENT_LENGTH,
1109 adjust (element_exported, element_length, PAILLIER_ELEMENT_LENGTH);
1110 memcpy (current, element_exported, PAILLIER_ELEMENT_LENGTH);
1111 current += PAILLIER_ELEMENT_LENGTH;
1114 for (i = 0; i < session->transferred; i++) {
1116 memset (element_exported, 0, PAILLIER_ELEMENT_LENGTH);
1117 GNUNET_assert (0 == gcry_mpi_print (GCRYMPI_FMT_USG,
1118 element_exported, PAILLIER_ELEMENT_LENGTH,
1121 adjust (element_exported, element_length, PAILLIER_ELEMENT_LENGTH);
1122 memcpy (current, element_exported, PAILLIER_ELEMENT_LENGTH);
1123 current += PAILLIER_ELEMENT_LENGTH;
1125 memset (element_exported, 0, PAILLIER_ELEMENT_LENGTH);
1126 GNUNET_assert (0 == gcry_mpi_print (GCRYMPI_FMT_USG,
1127 element_exported, PAILLIER_ELEMENT_LENGTH,
1129 session->r_prime[i]));
1130 adjust (element_exported, element_length, PAILLIER_ELEMENT_LENGTH);
1131 memcpy (current, element_exported, PAILLIER_ELEMENT_LENGTH);
1132 current += PAILLIER_ELEMENT_LENGTH;
1135 GNUNET_free (element_exported);
1136 for (i = 0; i < session->transferred; i++) {
1137 gcry_mpi_release (session->r_prime[i]);
1138 gcry_mpi_release (session->r[i]);
1140 gcry_mpi_release (s);
1141 gcry_mpi_release (s_prime);
1143 session->msg = (struct GNUNET_MessageHeader *) msg;
1144 session->service_transmit_handle =
1145 GNUNET_MESH_notify_transmit_ready (session->tunnel,
1147 GNUNET_TIME_UNIT_FOREVER_REL,
1151 //disconnect our client
1152 if (NULL == session->service_transmit_handle) {
1153 GNUNET_log (GNUNET_ERROR_TYPE_ERROR, _ ("Could not send service-response message via mesh!)\n"));
1154 session->state = FINALIZED;
1156 session->response->client_notification_task =
1157 GNUNET_SCHEDULER_add_now (&prepare_client_end_notification,
1161 if (session->transferred != session->used)
1163 session->state = WAITING_FOR_MULTIPART_TRANSMISSION;
1166 session->state = FINALIZED;
1167 GNUNET_free(session->r);
1168 GNUNET_free(session->r_prime);
1169 session->r_prime = NULL;
1179 * compute the values
1180 * (1)[]: $E_A(a_{pi(i)}) otimes E_A(- r_{pi(i)} - b_{pi(i)}) &= E_A(a_{pi(i)} - r_{pi(i)} - b_{pi(i)})$
1181 * (2)[]: $E_A(a_{pi'(i)}) otimes E_A(- r_{pi'(i)}) &= E_A(a_{pi'(i)} - r_{pi'(i)})$
1182 * S: $S := E_A(sum (r_i + b_i)^2)$
1183 * S': $S' := E_A(sum r_i^2)$
1185 * @param request the requesting session + bob's requesting peer
1186 * @param response the responding session + bob's client handle
1187 * @return GNUNET_SYSERR if the computation failed
1188 * GNUNET_OK if everything went well.
1191 compute_service_response (struct ServiceSession * request,
1192 struct ServiceSession * response)
1196 int ret = GNUNET_SYSERR;
1200 gcry_mpi_t * rand = NULL;
1201 gcry_mpi_t * r = NULL;
1202 gcry_mpi_t * r_prime = NULL;
1205 gcry_mpi_t * a_pi_prime;
1207 gcry_mpi_t * rand_pi;
1208 gcry_mpi_t * rand_pi_prime;
1209 gcry_mpi_t s = NULL;
1210 gcry_mpi_t s_prime = NULL;
1211 gcry_mpi_t remote_n = NULL;
1212 gcry_mpi_t remote_nsquare;
1213 gcry_mpi_t remote_g = NULL;
1214 gcry_sexp_t tmp_exp;
1217 count = request->used;
1219 b = GNUNET_malloc (sizeof (gcry_mpi_t) * count);
1220 a_pi = GNUNET_malloc (sizeof (gcry_mpi_t) * count);
1221 b_pi = GNUNET_malloc (sizeof (gcry_mpi_t) * count);
1222 a_pi_prime = GNUNET_malloc (sizeof (gcry_mpi_t) * count);
1223 rand_pi = GNUNET_malloc (sizeof (gcry_mpi_t) * count);
1224 rand_pi_prime = GNUNET_malloc (sizeof (gcry_mpi_t) * count);
1226 // convert responder session to from long to mpi
1227 for (i = 0, j = 0; i < response->total && j < count; i++) {
1228 if (request->mask[i / 8] & (1 << (i % 8))) {
1229 value = response->vector[i] >= 0 ? response->vector[i] : -response->vector[i];
1230 // long to gcry_mpi_t
1231 if (0 > response->vector[i]) {
1232 b[j] = gcry_mpi_new (0);
1233 gcry_mpi_sub_ui (b[j], b[j], value);
1236 b[j] = gcry_mpi_set_ui (NULL, value);
1241 GNUNET_free (response->vector);
1242 response->vector = NULL;
1244 tmp_exp = gcry_sexp_find_token (request->remote_pubkey, "n", 0);
1246 GNUNET_break_op (0);
1247 gcry_sexp_release (request->remote_pubkey);
1248 request->remote_pubkey = NULL;
1251 remote_n = gcry_sexp_nth_mpi (tmp_exp, 1, GCRYMPI_FMT_USG);
1254 gcry_sexp_release (tmp_exp);
1257 remote_nsquare = gcry_mpi_new (KEYBITS + 1);
1258 gcry_mpi_mul (remote_nsquare, remote_n, remote_n);
1259 gcry_sexp_release (tmp_exp);
1260 tmp_exp = gcry_sexp_find_token (request->remote_pubkey, "g", 0);
1261 gcry_sexp_release (request->remote_pubkey);
1262 request->remote_pubkey = NULL;
1264 GNUNET_break_op (0);
1265 gcry_mpi_release (remote_n);
1268 remote_g = gcry_sexp_nth_mpi (tmp_exp, 1, GCRYMPI_FMT_USG);
1271 gcry_mpi_release (remote_n);
1272 gcry_sexp_release (tmp_exp);
1275 gcry_sexp_release (tmp_exp);
1277 // generate r, p and q
1278 rand = initialize_mpi_vector (count);
1279 for (i = 0; i < count; i++) {
1280 value = (int32_t) GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK, UINT32_MAX);
1282 // long to gcry_mpi_t
1284 gcry_mpi_sub_ui (rand[i],
1288 rand[i] = gcry_mpi_set_ui (rand[i], value);
1290 p = GNUNET_CRYPTO_random_permute (GNUNET_CRYPTO_QUALITY_WEAK, count);
1291 q = GNUNET_CRYPTO_random_permute (GNUNET_CRYPTO_QUALITY_WEAK, count);
1292 //initialize the result vectors
1293 r = initialize_mpi_vector (count);
1294 r_prime = initialize_mpi_vector (count);
1296 // copy the REFERNCES of a, b and r into aq and bq. we will not change
1297 // those values, thus we can work with the references
1298 memcpy (a_pi, request->a, sizeof (gcry_mpi_t) * count);
1299 memcpy (a_pi_prime, request->a, sizeof (gcry_mpi_t) * count);
1300 memcpy (b_pi, b, sizeof (gcry_mpi_t) * count);
1301 memcpy (rand_pi, rand, sizeof (gcry_mpi_t) * count);
1302 memcpy (rand_pi_prime, rand, sizeof (gcry_mpi_t) * count);
1304 // generate p and q permutations for a, b and r
1305 GNUNET_assert (permute_vector (a_pi, p, count));
1306 GNUNET_assert (permute_vector (b_pi, p, count));
1307 GNUNET_assert (permute_vector (rand_pi, p, count));
1308 GNUNET_assert (permute_vector (a_pi_prime, q, count));
1309 GNUNET_assert (permute_vector (rand_pi_prime, q, count));
1311 // encrypt the element
1312 // for the sake of readability I decided to have dedicated permutation
1313 // vectors, which get rid of all the lookups in p/q.
1314 // however, ap/aq are not absolutely necessary but are just abstraction
1315 // Calculate Kp = E(S + a_pi) (+) E(S - r_pi - b_pi)
1316 for (i = 0; i < count; i++) {
1317 // E(S - r_pi - b_pi)
1318 gcry_mpi_sub (r[i], my_offset, rand_pi[i]);
1319 gcry_mpi_sub (r[i], r[i], b_pi[i]);
1320 encrypt_element (r[i], r[i], remote_g, remote_n, remote_nsquare);
1322 // E(S - r_pi - b_pi) * E(S + a_pi) == E(2*S + a - r - b)
1323 gcry_mpi_mulm (r[i], r[i], a_pi[i], remote_nsquare);
1327 GNUNET_free (rand_pi);
1329 // Calculate Kq = E(S + a_qi) (+) E(S - r_qi)
1330 for (i = 0; i < count; i++) {
1332 gcry_mpi_sub (r_prime[i], my_offset, rand_pi_prime[i]);
1333 encrypt_element (r_prime[i], r_prime[i], remote_g, remote_n, remote_nsquare);
1335 // E(S - r_qi) * E(S + a_qi) == E(2*S + a_qi - r_qi)
1336 gcry_mpi_mulm (r_prime[i], r_prime[i], a_pi_prime[i], remote_nsquare);
1338 GNUNET_free (a_pi_prime);
1339 GNUNET_free (rand_pi_prime);
1342 request->r_prime = r_prime;
1343 request->response = response;
1345 // Calculate S' = E(SUM( r_i^2 ))
1346 s_prime = compute_square_sum (rand, count);
1347 encrypt_element (s_prime, s_prime, remote_g, remote_n, remote_nsquare);
1349 // Calculate S = E(SUM( (r_i + b_i)^2 ))
1350 for (i = 0; i < count; i++) {
1351 gcry_mpi_add (rand[i], rand[i], b[i]);
1353 s = compute_square_sum (rand, count);
1354 encrypt_element (s, s, remote_g, remote_n, remote_nsquare);
1355 gcry_mpi_release (remote_n);
1356 gcry_mpi_release (remote_g);
1357 gcry_mpi_release (remote_nsquare);
1359 // release r and tmp
1360 for (i = 0; i < count; i++)
1361 // rp, rq, aq, ap, bp, bq are released along with a, r, b respectively, (a and b are handled at except:)
1362 gcry_mpi_release (rand[i]);
1364 // copy the r[], r_prime[], S and Stick into a new message, prepare_service_response frees these
1365 if (GNUNET_YES != prepare_service_response (s, s_prime, request))
1366 GNUNET_log (GNUNET_ERROR_TYPE_INFO, _ ("Failed to communicate with `%s', scalar product calculation aborted.\n"),
1367 GNUNET_i2s (&request->peer));
1372 for (i = 0; i < count; i++) {
1373 gcry_mpi_release (b[i]);
1374 gcry_mpi_release (request->a[i]);
1378 GNUNET_free (request->a);
1386 * Send a multi part chunk of a service request from alice to bob.
1387 * This element only contains a part of the elements-vector (session->a[]),
1388 * mask and public key set have to be contained within the first message
1390 * This allows a ~32kbit key length while using 32000 elements or 62000 elements per request.
1392 * @param cls the associated service session
1395 prepare_service_request_multipart (void *cls)
1397 struct ServiceSession * session = cls;
1398 unsigned char * current;
1399 unsigned char * element_exported;
1400 struct GNUNET_SCALARPRODUCT_multipart_message * msg;
1403 uint32_t msg_length;
1404 uint32_t todo_count;
1405 size_t element_length = 0; // initialized by gcry_mpi_print, but the compiler doesn't know that
1409 msg_length = sizeof (struct GNUNET_SCALARPRODUCT_multipart_message);
1410 todo_count = session->used - session->transferred;
1412 if (todo_count > MULTIPART_ELEMENT_CAPACITY)
1413 // send the currently possible maximum chunk
1414 todo_count = MULTIPART_ELEMENT_CAPACITY;
1416 msg_length += todo_count * PAILLIER_ELEMENT_LENGTH;
1417 msg = GNUNET_malloc (msg_length);
1418 msg->header.type = htons (GNUNET_MESSAGE_TYPE_SCALARPRODUCT_ALICE_TO_BOB_MULTIPART);
1419 msg->header.size = htons (msg_length);
1420 msg->multipart_element_count = htonl (todo_count);
1422 element_exported = GNUNET_malloc (PAILLIER_ELEMENT_LENGTH);
1423 a = gcry_mpi_new (KEYBITS * 2);
1424 current = (unsigned char *) &msg[1];
1425 // encrypt our vector and generate string representations
1426 for (i = session->last_processed, j = 0; i < session->total; i++) {
1427 // is this a used element?
1428 if (session->mask[i / 8] & 1 << (i % 8)) {
1429 if (todo_count <= j)
1430 break; //reached end of this message, can't include more
1432 memset (element_exported, 0, PAILLIER_ELEMENT_LENGTH);
1433 value = session->vector[i] >= 0 ? session->vector[i] : -session->vector[i];
1435 a = gcry_mpi_set_ui (a, 0);
1436 // long to gcry_mpi_t
1437 if (session->vector[i] < 0)
1438 gcry_mpi_sub_ui (a, a, value);
1440 gcry_mpi_add_ui (a, a, value);
1442 session->a[session->transferred + j++] = gcry_mpi_set (NULL, a);
1443 gcry_mpi_add (a, a, my_offset);
1444 encrypt_element (a, a, my_g, my_n, my_nsquare);
1446 // get representation as string
1447 // we always supply some value, so gcry_mpi_print fails only if it can't reserve memory
1448 GNUNET_assert (!gcry_mpi_print (GCRYMPI_FMT_USG,
1449 element_exported, PAILLIER_ELEMENT_LENGTH,
1453 // move buffer content to the end of the buffer so it can easily be read by libgcrypt. also this now has fixed size
1454 adjust (element_exported, element_length, PAILLIER_ELEMENT_LENGTH);
1456 // copy over to the message
1457 memcpy (current, element_exported, PAILLIER_ELEMENT_LENGTH);
1458 current += PAILLIER_ELEMENT_LENGTH;
1461 gcry_mpi_release (a);
1462 GNUNET_free (element_exported);
1463 session->transferred += todo_count;
1465 session->msg = (struct GNUNET_MessageHeader *) msg;
1466 GNUNET_log (GNUNET_ERROR_TYPE_INFO, _ ("Transmitting service request.\n"));
1468 //transmit via mesh messaging
1469 session->service_transmit_handle = GNUNET_MESH_notify_transmit_ready (session->tunnel, GNUNET_YES,
1470 GNUNET_TIME_UNIT_FOREVER_REL,
1474 if (!session->service_transmit_handle) {
1475 GNUNET_log (GNUNET_ERROR_TYPE_ERROR, _ ("Could not send service-request multipart message to tunnel!\n"));
1477 session->msg = NULL;
1478 session->client_notification_task =
1479 GNUNET_SCHEDULER_add_now (&prepare_client_end_notification,
1483 if (session->transferred != session->used) {
1484 session->last_processed = i;
1488 session->state = WAITING_FOR_SERVICE_RESPONSE;
1493 * Executed by Alice, fills in a service-request message and sends it to the given peer
1495 * @param cls the session associated with this request
1496 * @param tc task context handed over by scheduler, unsued
1499 prepare_service_request (void *cls,
1500 const struct GNUNET_SCHEDULER_TaskContext *tc)
1502 struct ServiceSession * session = cls;
1503 unsigned char * current;
1504 unsigned char * element_exported;
1505 struct GNUNET_SCALARPRODUCT_service_request * msg;
1508 uint32_t msg_length;
1509 size_t element_length = 0; // initialized by gcry_mpi_print, but the compiler doesn't know that
1513 session->service_request_task = GNUNET_SCHEDULER_NO_TASK;
1515 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, _ ("Successfully created new tunnel to peer (%s)!\n"), GNUNET_i2s (&session->peer));
1517 msg_length = sizeof (struct GNUNET_SCALARPRODUCT_service_request)
1518 +session->mask_length
1519 + my_pubkey_external_length;
1521 if (GNUNET_SERVER_MAX_MESSAGE_SIZE > msg_length + session->used * PAILLIER_ELEMENT_LENGTH) {
1522 msg_length += session->used * PAILLIER_ELEMENT_LENGTH;
1523 session->transferred = session->used;
1526 //create a multipart msg, first we calculate a new msg size for the head msg
1527 session->transferred = (GNUNET_SERVER_MAX_MESSAGE_SIZE - 1 - msg_length) / PAILLIER_ELEMENT_LENGTH;
1530 msg = GNUNET_malloc (msg_length);
1531 msg->header.type = htons (GNUNET_MESSAGE_TYPE_SCALARPRODUCT_ALICE_TO_BOB);
1532 msg->total_element_count = htonl (session->used);
1533 msg->contained_element_count = htonl (session->transferred);
1534 memcpy (&msg->key, &session->key, sizeof (struct GNUNET_HashCode));
1535 msg->mask_length = htonl (session->mask_length);
1536 msg->pk_length = htonl (my_pubkey_external_length);
1537 msg->element_count = htonl (session->total);
1538 msg->header.size = htons (msg_length);
1540 // fill in the payload
1541 current = (unsigned char *) &msg[1];
1542 // copy over the mask
1543 memcpy (current, session->mask, session->mask_length);
1544 // copy over our public key
1545 current += session->mask_length;
1546 memcpy (current, my_pubkey_external, my_pubkey_external_length);
1547 current += my_pubkey_external_length;
1549 // now copy over the element vector
1550 element_exported = GNUNET_malloc (PAILLIER_ELEMENT_LENGTH);
1551 session->a = GNUNET_malloc (sizeof (gcry_mpi_t) * session->used);
1552 a = gcry_mpi_new (KEYBITS * 2);
1553 // encrypt our vector and generate string representations
1554 for (i = 0, j = 0; i < session->total; i++) {
1555 // if this is a used element...
1556 if (session->mask[i / 8] & 1 << (i % 8)) {
1557 if (session->transferred <= j)
1558 break; //reached end of this message, can't include more
1560 memset (element_exported, 0, PAILLIER_ELEMENT_LENGTH);
1561 value = session->vector[i] >= 0 ? session->vector[i] : -session->vector[i];
1563 a = gcry_mpi_set_ui (a, 0);
1564 // long to gcry_mpi_t
1565 if (session->vector[i] < 0)
1566 gcry_mpi_sub_ui (a, a, value);
1568 gcry_mpi_add_ui (a, a, value);
1570 session->a[j++] = gcry_mpi_set (NULL, a);
1571 gcry_mpi_add (a, a, my_offset);
1572 encrypt_element (a, a, my_g, my_n, my_nsquare);
1574 // get representation as string
1575 // we always supply some value, so gcry_mpi_print fails only if it can't reserve memory
1576 GNUNET_assert (!gcry_mpi_print (GCRYMPI_FMT_USG,
1577 element_exported, PAILLIER_ELEMENT_LENGTH,
1581 // move buffer content to the end of the buffer so it can easily be read by libgcrypt. also this now has fixed size
1582 adjust (element_exported, element_length, PAILLIER_ELEMENT_LENGTH);
1584 // copy over to the message
1585 memcpy (current, element_exported, PAILLIER_ELEMENT_LENGTH);
1586 current += PAILLIER_ELEMENT_LENGTH;
1589 gcry_mpi_release (a);
1590 GNUNET_free (element_exported);
1592 session->msg = (struct GNUNET_MessageHeader *) msg;
1593 GNUNET_log (GNUNET_ERROR_TYPE_INFO, _ ("Transmitting service request.\n"));
1595 //transmit via mesh messaging
1596 session->service_transmit_handle = GNUNET_MESH_notify_transmit_ready (session->tunnel, GNUNET_YES,
1597 GNUNET_TIME_UNIT_FOREVER_REL,
1601 if (!session->service_transmit_handle) {
1602 GNUNET_log (GNUNET_ERROR_TYPE_ERROR, _ ("Could not send message to tunnel!\n"));
1604 session->msg = NULL;
1605 session->client_notification_task =
1606 GNUNET_SCHEDULER_add_now (&prepare_client_end_notification,
1610 if (session->transferred != session->used) {
1611 session->state = WAITING_FOR_MULTIPART_TRANSMISSION;
1612 session->last_processed = i;
1615 //singlepart message
1616 session->state = WAITING_FOR_SERVICE_RESPONSE;
1621 * Handler for a client request message.
1622 * Can either be type A or B
1623 * A: request-initiation to compute a scalar product with a peer
1624 * B: response role, keep the values + session and wait for a matching session or process a waiting request
1626 * @param cls closure
1627 * @param client identification of the client
1628 * @param message the actual message
1631 handle_client_request (void *cls,
1632 struct GNUNET_SERVER_Client *client,
1633 const struct GNUNET_MessageHeader *message)
1635 const struct GNUNET_SCALARPRODUCT_client_request * msg = (const struct GNUNET_SCALARPRODUCT_client_request *) message;
1636 struct ServiceSession * session;
1637 uint32_t element_count;
1638 uint32_t mask_length;
1643 // only one concurrent session per client connection allowed, simplifies logics a lot...
1644 session = GNUNET_SERVER_client_get_user_context (client, struct ServiceSession);
1645 if ((NULL != session) && (session->state != FINALIZED)) {
1646 GNUNET_SERVER_receive_done (client, GNUNET_OK);
1649 else if (NULL != session) {
1650 // old session is already completed, clean it up
1651 GNUNET_CONTAINER_DLL_remove (from_client_head, from_client_tail, session);
1652 free_session_variables (session);
1653 GNUNET_free (session);
1656 //we need at least a peer and one message id to compare
1657 if (sizeof (struct GNUNET_SCALARPRODUCT_client_request) > ntohs (msg->header.size)) {
1658 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
1659 _ ("Too short message received from client!\n"));
1660 GNUNET_SERVER_receive_done (client, GNUNET_SYSERR);
1664 msg_type = ntohs (msg->header.type);
1665 element_count = ntohl (msg->element_count);
1666 mask_length = ntohl (msg->mask_length);
1668 //sanity check: is the message as long as the message_count fields suggests?
1669 if ((ntohs (msg->header.size) != (sizeof (struct GNUNET_SCALARPRODUCT_client_request) +element_count * sizeof (int32_t) + mask_length))
1670 || (0 == element_count)) {
1671 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
1672 _ ("Invalid message received from client, session information incorrect!\n"));
1673 GNUNET_SERVER_receive_done (client, GNUNET_SYSERR);
1677 // do we have a duplicate session here already?
1678 if (NULL != find_matching_session (from_client_tail,
1682 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
1683 _ ("Duplicate session information received, cannot create new session with key `%s'\n"),
1684 GNUNET_h2s (&msg->key));
1685 GNUNET_SERVER_receive_done (client, GNUNET_SYSERR);
1689 session = GNUNET_new (struct ServiceSession);
1690 session->service_request_task = GNUNET_SCHEDULER_NO_TASK;
1691 session->client_notification_task = GNUNET_SCHEDULER_NO_TASK;
1692 session->client = client;
1693 session->total = element_count;
1694 session->mask_length = mask_length;
1695 // get our transaction key
1696 memcpy (&session->key, &msg->key, sizeof (struct GNUNET_HashCode));
1697 //allocate memory for vector and encrypted vector
1698 session->vector = GNUNET_malloc (sizeof (int32_t) * element_count);
1699 vector = (int32_t *) & msg[1];
1701 if (GNUNET_MESSAGE_TYPE_SCALARPRODUCT_CLIENT_TO_ALICE == msg_type) {
1702 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1703 _ ("Got client-request-session with key %s, preparing tunnel to remote service.\n"),
1704 GNUNET_h2s (&session->key));
1706 session->role = ALICE;
1708 session->mask = GNUNET_malloc (mask_length);
1709 memcpy (session->mask, &vector[element_count], mask_length);
1711 // copy over the elements
1713 for (i = 0; i < element_count; i++) {
1714 session->vector[i] = ntohl (vector[i]);
1715 if (session->vector[i] == 0)
1716 session->mask[i / 8] &= ~(1 << (i % 8));
1717 if (session->mask[i / 8] & (1 << (i % 8)))
1721 if (0 == session->used) {
1722 GNUNET_break_op (0);
1723 GNUNET_free (session->vector);
1724 GNUNET_free (session);
1725 GNUNET_SERVER_receive_done (client, GNUNET_SYSERR);
1728 //session with ourself makes no sense!
1729 if (!memcmp (&msg->peer, &me, sizeof (struct GNUNET_PeerIdentity))) {
1731 GNUNET_free (session->vector);
1732 GNUNET_free (session);
1733 GNUNET_SERVER_receive_done (client, GNUNET_SYSERR);
1737 memcpy (&session->peer, &msg->peer, sizeof (struct GNUNET_PeerIdentity));
1738 GNUNET_log (GNUNET_ERROR_TYPE_INFO,
1739 _ ("Creating new tunnel for session with key %s.\n"),
1740 GNUNET_h2s (&session->key));
1741 session->tunnel = GNUNET_MESH_tunnel_create (my_mesh, session,
1743 GNUNET_APPLICATION_TYPE_SCALARPRODUCT,
1746 //prepare_service_request, tunnel_peer_disconnect_handler,
1747 if (!session->tunnel) {
1749 GNUNET_free (session->vector);
1750 GNUNET_free (session);
1751 GNUNET_SERVER_receive_done (client, GNUNET_SYSERR);
1754 GNUNET_SERVER_client_set_user_context (client, session);
1755 GNUNET_CONTAINER_DLL_insert (from_client_head, from_client_tail, session);
1757 session->state = CLIENT_REQUEST_RECEIVED;
1758 session->service_request_task =
1759 GNUNET_SCHEDULER_add_now (&prepare_service_request,
1764 struct ServiceSession * requesting_session;
1765 enum SessionState needed_state = SERVICE_REQUEST_RECEIVED;
1767 session->role = BOB;
1768 session->mask = NULL;
1769 // copy over the elements
1770 session->used = element_count;
1771 for (i = 0; i < element_count; i++)
1772 session->vector[i] = ntohl (vector[i]);
1773 session->state = CLIENT_RESPONSE_RECEIVED;
1775 GNUNET_SERVER_client_set_user_context (client, session);
1776 GNUNET_CONTAINER_DLL_insert (from_client_head, from_client_tail, session);
1778 //check if service queue contains a matching request
1779 requesting_session = find_matching_session (from_service_tail,
1782 &needed_state, NULL);
1783 if (NULL != requesting_session) {
1784 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));
1785 if (GNUNET_OK != compute_service_response (requesting_session, session))
1786 session->client_notification_task =
1787 GNUNET_SCHEDULER_add_now (&prepare_client_end_notification,
1792 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));
1793 // no matching session exists yet, store the response
1794 // for later processing by handle_service_request()
1797 GNUNET_SERVER_receive_done (client, GNUNET_YES);
1802 * Function called for inbound tunnels.
1804 * @param cls closure
1805 * @param tunnel new handle to the tunnel
1806 * @param initiator peer that started the tunnel
1807 * @param port unused
1808 * @return session associated with the tunnel
1811 tunnel_incoming_handler (void *cls,
1812 struct GNUNET_MESH_Tunnel *tunnel,
1813 const struct GNUNET_PeerIdentity *initiator,
1816 struct ServiceSession * c = GNUNET_new (struct ServiceSession);
1818 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, _ ("New incoming tunnel from peer %s.\n"), GNUNET_i2s (initiator));
1820 c->peer = *initiator;
1823 c->state = WAITING_FOR_SERVICE_REQUEST;
1829 * Function called whenever a tunnel is destroyed. Should clean up
1830 * any associated state.
1832 * It must NOT call GNUNET_MESH_tunnel_destroy on the tunnel.
1834 * @param cls closure (set from GNUNET_MESH_connect)
1835 * @param tunnel connection to the other end (henceforth invalid)
1836 * @param tunnel_ctx place where local state associated
1837 * with the tunnel is stored
1840 tunnel_destruction_handler (void *cls,
1841 const struct GNUNET_MESH_Tunnel *tunnel,
1844 struct ServiceSession * session = tunnel_ctx;
1845 struct ServiceSession * client_session;
1846 struct ServiceSession * curr;
1848 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1849 _ ("Peer disconnected, terminating session %s with peer (%s)\n"),
1850 GNUNET_h2s (&session->key),
1851 GNUNET_i2s (&session->peer));
1852 if (ALICE == session->role) {
1853 // as we have only one peer connected in each session, just remove the session
1855 if ((SERVICE_RESPONSE_RECEIVED > session->state) && (!do_shutdown)) {
1856 session->tunnel = NULL;
1857 // if this happened before we received the answer, we must terminate the session
1858 session->client_notification_task =
1859 GNUNET_SCHEDULER_add_now (&prepare_client_end_notification,
1863 else { //(BOB == session->role) service session
1864 // remove the session, unless it has already been dequeued, but somehow still active
1865 // this could bug without the IF in case the queue is empty and the service session was the only one know to the service
1866 // scenario: disconnect before alice can send her message to bob.
1867 for (curr = from_service_head; NULL != curr; curr = curr->next)
1868 if (curr == session) {
1869 GNUNET_CONTAINER_DLL_remove (from_service_head, from_service_tail, curr);
1872 // there is a client waiting for this service session, terminate it, too!
1873 // i assume the tupel of key and element count is unique. if it was not the rest of the code would not work either.
1874 client_session = find_matching_session (from_client_tail,
1878 free_session_variables (session);
1879 GNUNET_free (session);
1881 // the client has to check if it was waiting for a result
1882 // or if it was a responder, no point in adding more statefulness
1883 if (client_session && (!do_shutdown)) {
1884 client_session->state = FINALIZED;
1885 client_session->client_notification_task =
1886 GNUNET_SCHEDULER_add_now (&prepare_client_end_notification,
1894 * Compute our scalar product, done by Alice
1896 * @param session - the session associated with this computation
1897 * @return product as MPI, never NULL
1900 compute_scalar_product (struct ServiceSession * session)
1911 count = session->used;
1912 tmp = gcry_mpi_new (KEYBITS);
1913 // due to the introduced static offset S, we now also have to remove this
1914 // from the E(a_pi)(+)E(-b_pi-r_pi) and E(a_qi)(+)E(-r_qi) twice each,
1915 // the result is E((S + a_pi) + (S -b_pi-r_pi)) and E(S + a_qi + S - r_qi)
1916 for (i = 0; i < count; i++) {
1917 decrypt_element (session->r[i], session->r[i], my_mu, my_lambda, my_n, my_nsquare);
1918 gcry_mpi_sub (session->r[i], session->r[i], my_offset);
1919 gcry_mpi_sub (session->r[i], session->r[i], my_offset);
1920 decrypt_element (session->r_prime[i], session->r_prime[i], my_mu, my_lambda, my_n, my_nsquare);
1921 gcry_mpi_sub (session->r_prime[i], session->r_prime[i], my_offset);
1922 gcry_mpi_sub (session->r_prime[i], session->r_prime[i], my_offset);
1925 // calculate t = sum(ai)
1926 t = compute_square_sum (session->a, count);
1929 u = gcry_mpi_new (0);
1930 tmp = compute_square_sum (session->r, count);
1931 gcry_mpi_sub (u, u, tmp);
1932 gcry_mpi_release (tmp);
1935 u_prime = gcry_mpi_new (0);
1936 tmp = compute_square_sum (session->r_prime, count);
1937 gcry_mpi_sub (u_prime, u_prime, tmp);
1939 GNUNET_assert (p = gcry_mpi_new (0));
1940 GNUNET_assert (p_prime = gcry_mpi_new (0));
1943 decrypt_element (session->s, session->s, my_mu, my_lambda, my_n, my_nsquare);
1944 decrypt_element (session->s_prime, session->s_prime, my_mu, my_lambda, my_n, my_nsquare);
1947 gcry_mpi_add (p, session->s, t);
1948 gcry_mpi_add (p, p, u);
1951 gcry_mpi_add (p_prime, session->s_prime, t);
1952 gcry_mpi_add (p_prime, p_prime, u_prime);
1954 gcry_mpi_release (t);
1955 gcry_mpi_release (u);
1956 gcry_mpi_release (u_prime);
1959 gcry_mpi_sub (p, p, p_prime);
1960 gcry_mpi_release (p_prime);
1961 tmp = gcry_mpi_set_ui (tmp, 2);
1962 gcry_mpi_div (p, NULL, p, tmp, 0);
1964 gcry_mpi_release (tmp);
1965 for (i = 0; i < count; i++)
1966 gcry_mpi_release (session->a[i]);
1967 GNUNET_free (session->a);
1975 * Handle a multipart-chunk of a request from another service to calculate a scalarproduct with us.
1977 * @param cls closure (set from #GNUNET_MESH_connect)
1978 * @param tunnel connection to the other end
1979 * @param tunnel_ctx place to store local state associated with the tunnel
1980 * @param message the actual message
1981 * @return #GNUNET_OK to keep the connection open,
1982 * #GNUNET_SYSERR to close it (signal serious error)
1985 handle_service_request_multipart (void *cls,
1986 struct GNUNET_MESH_Tunnel * tunnel,
1988 const struct GNUNET_MessageHeader * message)
1990 struct ServiceSession * session;
1991 const struct GNUNET_SCALARPRODUCT_multipart_message * msg = (const struct GNUNET_SCALARPRODUCT_multipart_message *) message;
1992 uint32_t used_elements;
1993 uint32_t contained_elements = 0;
1994 uint32_t msg_length;
1995 unsigned char * current;
1999 // are we in the correct state?
2000 session = (struct ServiceSession *) * tunnel_ctx;
2001 if ((BOB != session->role) || (WAITING_FOR_MULTIPART_TRANSMISSION != session->state)) {
2004 // shorter than minimum?
2005 if (ntohs (msg->header.size) <= sizeof (struct GNUNET_SCALARPRODUCT_multipart_message)) {
2008 used_elements = session->used;
2009 contained_elements = ntohl (msg->multipart_element_count);
2010 msg_length = sizeof (struct GNUNET_SCALARPRODUCT_multipart_message)
2011 +contained_elements * PAILLIER_ELEMENT_LENGTH;
2013 if ((ntohs (msg->header.size) != msg_length)
2014 || (used_elements < contained_elements + session->transferred)) {
2017 current = (unsigned char *) &msg[1];
2018 if (contained_elements != 0) {
2019 // Convert each vector element to MPI_value
2020 for (i = session->transferred; i < session->transferred + contained_elements; i++) {
2022 if (0 != (rc = gcry_mpi_scan (&session->a[i],
2024 ¤t[i * PAILLIER_ELEMENT_LENGTH],
2025 PAILLIER_ELEMENT_LENGTH,
2027 LOG_GCRY (GNUNET_ERROR_TYPE_DEBUG, "gcry_mpi_scan", rc);
2031 session->transferred += contained_elements;
2033 if (session->transferred == used_elements) {
2034 // single part finished
2035 session->state = SERVICE_REQUEST_RECEIVED;
2036 if (session->response) {
2037 GNUNET_log (GNUNET_ERROR_TYPE_INFO, _ ("Got session with key %s and a matching element set, processing.\n"), GNUNET_h2s (&session->key));
2038 if (GNUNET_OK != compute_service_response (session, session->response)) {
2039 //something went wrong, remove it again...
2044 GNUNET_log (GNUNET_ERROR_TYPE_INFO, _ ("Got session with key %s without a matching element set, queueing.\n"), GNUNET_h2s (&session->key));
2047 // multipart message
2053 // and notify our client-session that we could not complete the session
2054 GNUNET_CONTAINER_DLL_remove (from_service_head, from_service_tail, session);
2055 if (session->response)
2056 // we just found the responder session in this queue
2057 session->response->client_notification_task =
2058 GNUNET_SCHEDULER_add_now (&prepare_client_end_notification,
2060 free_session_variables (session);
2061 GNUNET_free (session);
2062 return GNUNET_SYSERR;
2067 * Handle a request from another service to calculate a scalarproduct with us.
2069 * @param cls closure (set from #GNUNET_MESH_connect)
2070 * @param tunnel connection to the other end
2071 * @param tunnel_ctx place to store local state associated with the tunnel
2072 * @param message the actual message
2073 * @return #GNUNET_OK to keep the connection open,
2074 * #GNUNET_SYSERR to close it (signal serious error)
2077 handle_service_request (void *cls,
2078 struct GNUNET_MESH_Tunnel * tunnel,
2080 const struct GNUNET_MessageHeader * message)
2082 struct ServiceSession * session;
2083 const struct GNUNET_SCALARPRODUCT_service_request * msg = (const struct GNUNET_SCALARPRODUCT_service_request *) message;
2084 uint32_t mask_length;
2086 uint32_t used_elements;
2087 uint32_t contained_elements = 0;
2088 uint32_t element_count;
2089 uint32_t msg_length;
2090 unsigned char * current;
2093 enum SessionState needed_state;
2095 session = (struct ServiceSession *) * tunnel_ctx;
2096 if (WAITING_FOR_SERVICE_REQUEST != session->state) {
2099 // Check if message was sent by me, which would be bad!
2100 if (!memcmp (&session->peer, &me, sizeof (struct GNUNET_PeerIdentity))) {
2101 GNUNET_free (session);
2103 return GNUNET_SYSERR;
2105 // shorter than expected?
2106 if (ntohs (msg->header.size) < sizeof (struct GNUNET_SCALARPRODUCT_service_request)) {
2107 GNUNET_free (session);
2108 GNUNET_break_op (0);
2109 return GNUNET_SYSERR;
2111 mask_length = ntohl (msg->mask_length);
2112 pk_length = ntohl (msg->pk_length);
2113 used_elements = ntohl (msg->total_element_count);
2114 contained_elements = ntohl (msg->contained_element_count);
2115 element_count = ntohl (msg->element_count);
2116 msg_length = sizeof (struct GNUNET_SCALARPRODUCT_service_request)
2117 +mask_length + pk_length + contained_elements * PAILLIER_ELEMENT_LENGTH;
2119 //sanity check: is the message as long as the message_count fields suggests?
2120 if ((ntohs (msg->header.size) != msg_length) || (element_count < used_elements) || (used_elements < contained_elements)
2121 || (used_elements == 0) || (mask_length != (element_count / 8 + (element_count % 8 ? 1 : 0)))
2123 GNUNET_free (session);
2124 GNUNET_break_op (0);
2125 return GNUNET_SYSERR;
2127 if (find_matching_session (from_service_tail,
2132 GNUNET_log (GNUNET_ERROR_TYPE_ERROR, _ ("Got message with duplicate session key (`%s'), ignoring service request.\n"), (const char *) &(msg->key));
2133 GNUNET_free (session);
2134 return GNUNET_SYSERR;
2137 session->total = element_count;
2138 session->used = used_elements;
2139 session->transferred = contained_elements;
2140 session->tunnel = tunnel;
2143 memcpy (&session->key, &msg->key, sizeof (struct GNUNET_HashCode));
2144 current = (unsigned char *) &msg[1];
2145 //preserve the mask, we will need that later on
2146 session->mask = GNUNET_malloc (mask_length);
2147 memcpy (session->mask, current, mask_length);
2149 current += mask_length;
2151 //convert the publickey to sexp
2152 if (0 != (rc = gcry_sexp_new (&session->remote_pubkey, current, pk_length, 1))) {
2153 LOG_GCRY (GNUNET_ERROR_TYPE_DEBUG, "gcry_sexp_new", rc);
2154 GNUNET_free (session->mask);
2155 GNUNET_free (session);
2156 return GNUNET_SYSERR;
2158 current += pk_length;
2159 //check if service queue contains a matching request
2160 needed_state = CLIENT_RESPONSE_RECEIVED;
2161 session->response = find_matching_session (from_client_tail,
2164 &needed_state, NULL);
2166 session->a = GNUNET_malloc (sizeof (gcry_mpi_t) * used_elements);
2167 session->state = WAITING_FOR_MULTIPART_TRANSMISSION;
2168 GNUNET_CONTAINER_DLL_insert (from_service_head, from_service_tail, session);
2169 if (contained_elements != 0) {
2170 // Convert each vector element to MPI_value
2171 for (i = 0; i < contained_elements; i++) {
2173 if (0 != (rc = gcry_mpi_scan (&session->a[i],
2175 ¤t[i * PAILLIER_ELEMENT_LENGTH],
2176 PAILLIER_ELEMENT_LENGTH,
2178 LOG_GCRY (GNUNET_ERROR_TYPE_DEBUG, "gcry_mpi_scan", rc);
2182 if (contained_elements == used_elements) {
2183 // single part finished
2184 session->state = SERVICE_REQUEST_RECEIVED;
2185 if (session->response) {
2186 GNUNET_log (GNUNET_ERROR_TYPE_INFO, _ ("Got session with key %s and a matching element set, processing.\n"), GNUNET_h2s (&session->key));
2187 if (GNUNET_OK != compute_service_response (session, session->response)) {
2188 //something went wrong, remove it again...
2193 GNUNET_log (GNUNET_ERROR_TYPE_INFO, _ ("Got session with key %s without a matching element set, queueing.\n"), GNUNET_h2s (&session->key));
2196 // multipart message
2201 GNUNET_break_op (0);
2202 if ((NULL != session->next) || (NULL != session->prev) || (from_service_head == session))
2203 GNUNET_CONTAINER_DLL_remove (from_service_head, from_service_tail, session);
2204 // and notify our client-session that we could not complete the session
2205 if (session->response)
2206 // we just found the responder session in this queue
2207 session->response->client_notification_task =
2208 GNUNET_SCHEDULER_add_now (&prepare_client_end_notification,
2210 free_session_variables (session);
2211 return GNUNET_SYSERR;
2216 * Handle a multipart chunk of a response we got from another service we wanted to calculate a scalarproduct with.
2218 * @param cls closure (set from #GNUNET_MESH_connect)
2219 * @param tunnel connection to the other end
2220 * @param tunnel_ctx place to store local state associated with the tunnel
2221 * @param message the actual message
2222 * @return #GNUNET_OK to keep the connection open,
2223 * #GNUNET_SYSERR to close it (signal serious error)
2226 handle_service_response_multipart (void *cls,
2227 struct GNUNET_MESH_Tunnel * tunnel,
2229 const struct GNUNET_MessageHeader * message)
2231 struct ServiceSession * session;
2232 const struct GNUNET_SCALARPRODUCT_multipart_message * msg = (const struct GNUNET_SCALARPRODUCT_multipart_message *) message;
2233 unsigned char * current;
2236 uint32_t contained = 0;
2240 GNUNET_assert (NULL != message);
2241 // are we in the correct state?
2242 session = (struct ServiceSession *) * tunnel_ctx;
2243 if ((ALICE != session->role) || (WAITING_FOR_MULTIPART_TRANSMISSION != session->state)) {
2246 // shorter than minimum?
2247 if (ntohs (msg->header.size) <= sizeof (struct GNUNET_SCALARPRODUCT_multipart_message)) {
2250 contained = ntohl (msg->multipart_element_count);
2251 msg_size = sizeof (struct GNUNET_SCALARPRODUCT_multipart_message)
2252 + 2 * contained * PAILLIER_ELEMENT_LENGTH;
2253 //sanity check: is the message as long as the message_count fields suggests?
2254 if ((ntohs (msg->header.size) != msg_size) || (session->used < contained)) {
2257 current = (unsigned char *) &msg[1];
2258 // Convert each k[][perm] to its MPI_value
2259 for (i = 0; i < contained; i++) {
2260 if (0 != (rc = gcry_mpi_scan (&session->r[i], GCRYMPI_FMT_USG, current,
2261 PAILLIER_ELEMENT_LENGTH, &read))) {
2262 LOG_GCRY (GNUNET_ERROR_TYPE_DEBUG, "gcry_mpi_scan", rc);
2265 current += PAILLIER_ELEMENT_LENGTH;
2266 if (0 != (rc = gcry_mpi_scan (&session->r_prime[i], GCRYMPI_FMT_USG, current,
2267 PAILLIER_ELEMENT_LENGTH, &read))) {
2268 LOG_GCRY (GNUNET_ERROR_TYPE_DEBUG, "gcry_mpi_scan", rc);
2271 current += PAILLIER_ELEMENT_LENGTH;
2273 session->transferred += contained;
2274 if (session->transferred != session->used)
2276 session->state = SERVICE_RESPONSE_RECEIVED;
2277 session->product = compute_scalar_product (session);
2278 return GNUNET_SYSERR; // terminate the tunnel right away, we are done here!
2281 GNUNET_break_op (0);
2282 free_session_variables (session);
2283 session->state = FINALIZED;
2284 session->tunnel = NULL;
2285 // send message with product to client
2286 if (ALICE == session->role)
2287 session->client_notification_task =
2288 GNUNET_SCHEDULER_add_now (&prepare_client_response,
2290 // the tunnel has done its job, terminate our connection and the tunnel
2291 // the peer will be notified that the tunnel was destroyed via tunnel_destruction_handler
2292 // just close the connection, as recommended by Christian
2293 return GNUNET_SYSERR;
2298 * Handle a response we got from another service we wanted to calculate a scalarproduct with.
2300 * @param cls closure (set from #GNUNET_MESH_connect)
2301 * @param tunnel connection to the other end
2302 * @param tunnel_ctx place to store local state associated with the tunnel
2303 * @param message the actual message
2304 * @return #GNUNET_OK to keep the connection open,
2305 * #GNUNET_SYSERR to close it (we are done)
2308 handle_service_response (void *cls,
2309 struct GNUNET_MESH_Tunnel * tunnel,
2311 const struct GNUNET_MessageHeader * message)
2313 struct ServiceSession * session;
2314 const struct GNUNET_SCALARPRODUCT_service_response * msg = (const struct GNUNET_SCALARPRODUCT_service_response *) message;
2315 unsigned char * current;
2318 uint32_t contained = 0;
2322 GNUNET_assert (NULL != message);
2323 session = (struct ServiceSession *) * tunnel_ctx;
2324 // are we in the correct state?
2325 if (session->state != WAITING_FOR_SERVICE_REQUEST) {
2328 //we need at least a full message without elements attached
2329 msg_size = ntohs (msg->header.size);
2330 size_t expected = sizeof (struct GNUNET_SCALARPRODUCT_service_response) + 2 * PAILLIER_ELEMENT_LENGTH;
2332 if (expected > msg_size) {
2335 contained = ntohl (msg->contained_element_count);
2336 msg_size = sizeof (struct GNUNET_SCALARPRODUCT_service_response)
2337 + 2 * contained * PAILLIER_ELEMENT_LENGTH
2338 + 2 * PAILLIER_ELEMENT_LENGTH;
2339 //sanity check: is the message as long as the message_count fields suggests?
2340 if ((ntohs (msg->header.size) != msg_size) || (session->used < contained)) {
2343 session->state = WAITING_FOR_MULTIPART_TRANSMISSION;
2344 session->transferred = contained;
2346 current = (unsigned char *) &msg[1];
2347 if (0 != (rc = gcry_mpi_scan (&session->s, GCRYMPI_FMT_USG, current,
2348 PAILLIER_ELEMENT_LENGTH, &read))) {
2349 LOG_GCRY (GNUNET_ERROR_TYPE_DEBUG, "gcry_mpi_scan", rc);
2352 current += PAILLIER_ELEMENT_LENGTH;
2354 if (0 != (rc = gcry_mpi_scan (&session->s_prime, GCRYMPI_FMT_USG, current,
2355 PAILLIER_ELEMENT_LENGTH, &read))) {
2356 LOG_GCRY (GNUNET_ERROR_TYPE_DEBUG, "gcry_mpi_scan", rc);
2359 current += PAILLIER_ELEMENT_LENGTH;
2360 session->r = GNUNET_malloc (sizeof (gcry_mpi_t) * session->used);
2361 session->r_prime = GNUNET_malloc (sizeof (gcry_mpi_t) * session->used);
2362 // Convert each k[][perm] to its MPI_value
2363 for (i = 0; i < contained; i++) {
2364 if (0 != (rc = gcry_mpi_scan (&session->r[i], GCRYMPI_FMT_USG, current,
2365 PAILLIER_ELEMENT_LENGTH, &read))) {
2366 LOG_GCRY (GNUNET_ERROR_TYPE_DEBUG, "gcry_mpi_scan", rc);
2369 current += PAILLIER_ELEMENT_LENGTH;
2370 if (0 != (rc = gcry_mpi_scan (&session->r_prime[i], GCRYMPI_FMT_USG, current,
2371 PAILLIER_ELEMENT_LENGTH, &read))) {
2372 LOG_GCRY (GNUNET_ERROR_TYPE_DEBUG, "gcry_mpi_scan", rc);
2375 current += PAILLIER_ELEMENT_LENGTH;
2377 if (session->transferred != session->used)
2378 return GNUNET_OK; //wait for the other multipart chunks
2380 session->state = SERVICE_RESPONSE_RECEIVED;
2381 session->product = compute_scalar_product (session);
2382 return GNUNET_SYSERR; // terminate the tunnel right away, we are done here!
2385 GNUNET_break_op (0);
2386 free_session_variables (session);
2387 session->state = FINALIZED;
2388 session->tunnel = NULL;
2389 // send message with product to client
2390 if (ALICE == session->role)
2391 session->client_notification_task =
2392 GNUNET_SCHEDULER_add_now (&prepare_client_response,
2394 // the tunnel has done its job, terminate our connection and the tunnel
2395 // the peer will be notified that the tunnel was destroyed via tunnel_destruction_handler
2396 // just close the connection, as recommended by Christian
2397 return GNUNET_SYSERR;
2402 * Task run during shutdown.
2408 shutdown_task (void *cls,
2409 const struct GNUNET_SCHEDULER_TaskContext *tc)
2411 struct ServiceSession * session;
2412 GNUNET_log (GNUNET_ERROR_TYPE_INFO, _ ("Shutting down, initiating cleanup.\n"));
2414 do_shutdown = GNUNET_YES;
2416 // terminate all owned open tunnels.
2417 for (session = from_client_head; NULL != session; session = session->next) {
2418 if ((FINALIZED != session->state) && (NULL != session->tunnel)) {
2419 GNUNET_MESH_tunnel_destroy (session->tunnel);
2420 session->tunnel = NULL;
2422 if (GNUNET_SCHEDULER_NO_TASK != session->client_notification_task) {
2423 GNUNET_SCHEDULER_cancel (session->client_notification_task);
2424 session->client_notification_task = GNUNET_SCHEDULER_NO_TASK;
2426 if (GNUNET_SCHEDULER_NO_TASK != session->service_request_task) {
2427 GNUNET_SCHEDULER_cancel (session->service_request_task);
2428 session->service_request_task = GNUNET_SCHEDULER_NO_TASK;
2430 if (NULL != session->client) {
2431 GNUNET_SERVER_client_disconnect (session->client);
2432 session->client = NULL;
2435 for (session = from_service_head; NULL != session; session = session->next)
2436 if (NULL != session->tunnel) {
2437 GNUNET_MESH_tunnel_destroy (session->tunnel);
2438 session->tunnel = NULL;
2442 GNUNET_MESH_disconnect (my_mesh);
2449 * Initialization of the program and message handlers
2451 * @param cls closure
2452 * @param server the initialized server
2453 * @param c configuration to use
2457 struct GNUNET_SERVER_Handle *server,
2458 const struct GNUNET_CONFIGURATION_Handle *c)
2460 static const struct GNUNET_SERVER_MessageHandler server_handlers[] = {
2461 {&handle_client_request, NULL, GNUNET_MESSAGE_TYPE_SCALARPRODUCT_CLIENT_TO_ALICE, 0},
2462 {&handle_client_request, NULL, GNUNET_MESSAGE_TYPE_SCALARPRODUCT_CLIENT_TO_BOB, 0},
2465 static const struct GNUNET_MESH_MessageHandler mesh_handlers[] = {
2466 { &handle_service_request, GNUNET_MESSAGE_TYPE_SCALARPRODUCT_ALICE_TO_BOB, 0},
2467 { &handle_service_request_multipart, GNUNET_MESSAGE_TYPE_SCALARPRODUCT_ALICE_TO_BOB_MULTIPART, 0},
2468 { &handle_service_response, GNUNET_MESSAGE_TYPE_SCALARPRODUCT_BOB_TO_ALICE, 0},
2469 { &handle_service_response_multipart, GNUNET_MESSAGE_TYPE_SCALARPRODUCT_BOB_TO_ALICE_MULTIPART, 0},
2472 static const uint32_t ports[] = {
2473 GNUNET_APPLICATION_TYPE_SCALARPRODUCT,
2476 //generate private/public key set
2477 GNUNET_log (GNUNET_ERROR_TYPE_INFO, _ ("Generating Paillier-Keyset.\n"));
2479 // register server callbacks and disconnect handler
2480 GNUNET_SERVER_add_handlers (server, server_handlers);
2481 GNUNET_SERVER_disconnect_notify (server,
2482 &handle_client_disconnect,
2484 GNUNET_break (GNUNET_OK ==
2485 GNUNET_CRYPTO_get_peer_identity (c,
2487 my_mesh = GNUNET_MESH_connect (c, NULL,
2488 &tunnel_incoming_handler,
2489 &tunnel_destruction_handler,
2490 mesh_handlers, ports);
2492 GNUNET_log (GNUNET_ERROR_TYPE_ERROR, _ ("Connect to MESH failed\n"));
2493 GNUNET_SCHEDULER_shutdown ();
2496 GNUNET_log (GNUNET_ERROR_TYPE_INFO, _ ("Mesh initialized\n"));
2497 GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_FOREVER_REL,
2504 * The main function for the scalarproduct service.
2506 * @param argc number of arguments from the command line
2507 * @param argv command line arguments
2508 * @return 0 ok, 1 on error
2511 main (int argc, char *const *argv)
2513 return (GNUNET_OK ==
2514 GNUNET_SERVICE_run (argc, argv,
2516 GNUNET_SERVICE_OPTION_NONE,
2517 &run, NULL)) ? 0 : 1;
2520 /* end of gnunet-service-scalarproduct.c */