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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 * 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))
491 gcry_mpi_randomize (tmp, KEYBITS / 3, GCRY_WEAK_RANDOM);
492 // r must be 1 < r < n
495 gcry_mpi_powm (c, g, m, n_square);
496 gcry_mpi_powm (tmp, tmp, n, n_square);
497 gcry_mpi_mulm (c, tmp, c, n_square);
499 gcry_mpi_release (tmp);
504 * decrypts an element using the paillier crypto system
506 * @param m plaintext (output)
507 * @param c the ciphertext
508 * @param mu the modifier to correct encryption
509 * @param lambda the private exponent
510 * @param n the outer module for decryption
511 * @param n_square the inner module for decryption
514 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)
516 gcry_mpi_powm (m, c, lambda, n_square);
517 gcry_mpi_sub_ui (m, m, 1);
518 gcry_mpi_div (m, NULL, m, n, 0);
519 gcry_mpi_mulm (m, m, mu, n);
524 * computes the square sum over a vector of a given length.
526 * @param vector the vector to encrypt
527 * @param length the length of the vector
528 * @return an MPI value containing the calculated sum, never NULL
531 compute_square_sum (gcry_mpi_t * vector, uint32_t length)
537 GNUNET_assert (sum = gcry_mpi_new (0));
538 GNUNET_assert (elem = gcry_mpi_new (0));
540 // calculare E(sum (ai ^ 2), publickey)
541 for (i = 0; i < length; i++) {
542 gcry_mpi_mul (elem, vector[i], vector[i]);
543 gcry_mpi_add (sum, sum, elem);
545 gcry_mpi_release (elem);
552 * Primitive callback for copying over a message, as they
553 * usually are too complex to be handled in the callback itself.
554 * clears a session-callback, if a session was handed over and the transmit handle was stored
556 * @param cls the message object
557 * @param size the size of the buffer we got
558 * @param buf the buffer to copy the message to
559 * @return 0 if we couldn't copy, else the size copied over
562 do_send_message (void *cls, size_t size, void *buf)
564 struct ServiceSession * session = cls;
569 if (ntohs (session->msg->size) != size) {
574 type = ntohs (session->msg->type);
575 memcpy (buf, session->msg, size);
576 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
577 "Sent a message of type %hu.\n",
579 GNUNET_free (session->msg);
584 case GNUNET_MESSAGE_TYPE_SCALARPRODUCT_SERVICE_TO_CLIENT:
585 session->state = FINALIZED;
586 session->client_transmit_handle = NULL;
589 case GNUNET_MESSAGE_TYPE_SCALARPRODUCT_ALICE_TO_BOB:
590 case GNUNET_MESSAGE_TYPE_SCALARPRODUCT_ALICE_TO_BOB_MULTIPART:
591 session->service_transmit_handle = NULL;
592 if (session->state == WAITING_FOR_MULTIPART_TRANSMISSION)
593 prepare_service_request_multipart (session);
596 case GNUNET_MESSAGE_TYPE_SCALARPRODUCT_BOB_TO_ALICE:
597 case GNUNET_MESSAGE_TYPE_SCALARPRODUCT_BOB_TO_ALICE_MULTIPART:
598 session->service_transmit_handle = NULL;
599 if (session->state == WAITING_FOR_MULTIPART_TRANSMISSION)
600 prepare_service_response_multipart (session);
612 * initializes a new vector with fresh MPI values (=0) of a given length
614 * @param length of the vector to create
615 * @return the initialized vector, never NULL
618 initialize_mpi_vector (uint32_t length)
621 gcry_mpi_t * output = GNUNET_malloc (sizeof (gcry_mpi_t) * length);
623 for (i = 0; i < length; i++)
624 GNUNET_assert (NULL != (output[i] = gcry_mpi_new (0)));
630 * permutes an MPI vector according to the given permutation vector
632 * @param vector the vector to permuted
633 * @param perm the permutation to use
634 * @param length the length of the vectors
635 * @return the permuted vector (same as input), never NULL
638 permute_vector (gcry_mpi_t * vector,
642 gcry_mpi_t tmp[length];
645 GNUNET_assert (length > 0);
648 memcpy (tmp, vector, length * sizeof (gcry_mpi_t));
650 // permute vector according to given
651 for (i = 0; i < length; i++)
652 vector[i] = tmp[perm[i]];
659 * Finds a not terminated client/service session in the
660 * given DLL based on session key, element count and state.
662 * @param tail - the tail of the DLL
663 * @param key - the key we want to search for
664 * @param element_count - the total element count of the dataset (session->total)
665 * @param state - a pointer to the state the session should be in, NULL to ignore
666 * @param peerid - a pointer to the peer ID of the associated peer, NULL to ignore
667 * @return a pointer to a matching session, or NULL
669 static struct ServiceSession *
670 find_matching_session (struct ServiceSession * tail,
671 const struct GNUNET_HashCode * key,
672 uint32_t element_count,
673 enum SessionState * state,
674 const struct GNUNET_PeerIdentity * peerid)
676 struct ServiceSession * curr;
678 for (curr = tail; NULL != curr; curr = curr->prev) {
679 // if the key matches, and the element_count is same
680 if ((!memcmp (&curr->key, key, sizeof (struct GNUNET_HashCode)))
681 && (curr->total == element_count)) {
682 // if incoming state is NULL OR is same as state of the queued request
683 if ((NULL == state) || (curr->state == *state)) {
684 // if peerid is NULL OR same as the peer Id in the queued request
686 || (!memcmp (&curr->peer, peerid, sizeof (struct GNUNET_PeerIdentity))))
687 // 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);
713 GNUNET_free (session->mask);
714 session->mask = NULL;
717 for (i = 0; i < session->used; i++)
718 if (session->r[i]) gcry_mpi_release (session->r[i]);
719 GNUNET_free (session->r);
722 if (session->r_prime) {
723 for (i = 0; i < session->used; i++)
724 if (session->r_prime[i]) gcry_mpi_release (session->r_prime[i]);
725 GNUNET_free (session->r_prime);
726 session->r_prime = NULL;
729 gcry_mpi_release (session->s);
733 if (session->s_prime) {
734 gcry_mpi_release (session->s_prime);
735 session->s_prime = NULL;
738 if (session->product) {
739 gcry_mpi_release (session->product);
740 session->product = NULL;
743 if (session->remote_pubkey) {
744 gcry_sexp_release (session->remote_pubkey);
745 session->remote_pubkey = NULL;
748 if (session->vector) {
749 GNUNET_free_non_null (session->vector);
753 ///////////////////////////////////////////////////////////////////////////////
754 // Event and Message Handlers
755 ///////////////////////////////////////////////////////////////////////////////
759 * A client disconnected.
761 * Remove the associated session(s), release data structures
762 * and cancel pending outgoing transmissions to the client.
763 * if the session has not yet completed, we also cancel Alice's request to Bob.
765 * @param cls closure, NULL
766 * @param client identification of the client
769 handle_client_disconnect (void *cls,
770 struct GNUNET_SERVER_Client *client)
772 struct ServiceSession *session;
775 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
776 _ ("Client (%p) disconnected from us.\n"), client);
780 session = GNUNET_SERVER_client_get_user_context (client, struct ServiceSession);
783 GNUNET_CONTAINER_DLL_remove (from_client_head, from_client_tail, session);
785 if (!(session->role == BOB && session->state == FINALIZED)) {
786 //we MUST terminate any client message underway
787 if (session->service_transmit_handle && session->channel)
788 GNUNET_MESH_notify_transmit_ready_cancel (session->service_transmit_handle);
789 if (session->channel && session->state == WAITING_FOR_SERVICE_RESPONSE)
790 GNUNET_MESH_channel_destroy (session->channel);
792 if (GNUNET_SCHEDULER_NO_TASK != session->client_notification_task) {
793 GNUNET_SCHEDULER_cancel (session->client_notification_task);
794 session->client_notification_task = GNUNET_SCHEDULER_NO_TASK;
796 if (GNUNET_SCHEDULER_NO_TASK != session->service_request_task) {
797 GNUNET_SCHEDULER_cancel (session->service_request_task);
798 session->service_request_task = GNUNET_SCHEDULER_NO_TASK;
800 if (NULL != session->client_transmit_handle) {
801 GNUNET_SERVER_notify_transmit_ready_cancel (session->client_transmit_handle);
802 session->client_transmit_handle = NULL;
804 free_session_variables (session);
805 GNUNET_free (session);
810 * Notify the client that the session has succeeded or failed completely.
811 * This message gets sent to
812 * * alice's client if bob disconnected or to
813 * * bob's client if the operation completed or alice disconnected
815 * @param cls the associated client session
816 * @param tc the task context handed to us by the scheduler, unused
819 prepare_client_end_notification (void * cls,
820 const struct GNUNET_SCHEDULER_TaskContext * tc)
822 struct ServiceSession * session = cls;
823 struct GNUNET_SCALARPRODUCT_client_response * msg;
825 session->client_notification_task = GNUNET_SCHEDULER_NO_TASK;
827 msg = GNUNET_new (struct GNUNET_SCALARPRODUCT_client_response);
828 msg->header.type = htons (GNUNET_MESSAGE_TYPE_SCALARPRODUCT_SERVICE_TO_CLIENT);
829 memcpy (&msg->key, &session->key, sizeof (struct GNUNET_HashCode));
830 memcpy (&msg->peer, &session->peer, sizeof ( struct GNUNET_PeerIdentity));
831 msg->header.size = htons (sizeof (struct GNUNET_SCALARPRODUCT_client_response));
832 // signal error if not signalized, positive result-range field but zero length.
833 msg->product_length = htonl (0);
834 msg->range = (session->state == FINALIZED) ? 0 : -1;
836 session->msg = &msg->header;
838 //transmit this message to our client
839 session->client_transmit_handle =
840 GNUNET_SERVER_notify_transmit_ready (session->client,
841 sizeof (struct GNUNET_SCALARPRODUCT_client_response),
842 GNUNET_TIME_UNIT_FOREVER_REL,
846 // if we could not even queue our request, something is wrong
847 if (NULL == session->client_transmit_handle) {
848 GNUNET_log (GNUNET_ERROR_TYPE_WARNING, _ ("Could not send message to client (%p)!\n"), session->client);
849 // usually gets freed by do_send_message
854 GNUNET_log (GNUNET_ERROR_TYPE_INFO, _ ("Sending session-end notification to client (%p) for session %s\n"), &session->client, GNUNET_h2s (&session->key));
856 free_session_variables (session);
861 * prepare the response we will send to alice or bobs' clients.
862 * in Bobs case the product will be NULL.
864 * @param cls the session associated with our client.
865 * @param tc the task context handed to us by the scheduler, unused
868 prepare_client_response (void *cls,
869 const struct GNUNET_SCHEDULER_TaskContext *tc)
871 struct ServiceSession * session = cls;
872 struct GNUNET_SCALARPRODUCT_client_response * msg;
873 unsigned char * product_exported = NULL;
874 size_t product_length = 0;
875 uint32_t msg_length = 0;
880 session->client_notification_task = GNUNET_SCHEDULER_NO_TASK;
882 if (session->product) {
883 gcry_mpi_t value = gcry_mpi_new (0);
885 sign = gcry_mpi_cmp_ui (session->product, 0);
886 // libgcrypt can not handle a print of a negative number
887 // if (a->sign) return gcry_error (GPG_ERR_INTERNAL); /* Can't handle it yet. */
889 gcry_mpi_sub (value, value, session->product);
893 gcry_mpi_add (value, value, session->product);
898 gcry_mpi_release (session->product);
899 session->product = NULL;
901 // get representation as string
903 && (0 != (rc = gcry_mpi_aprint (GCRYMPI_FMT_STD,
907 LOG_GCRY (GNUNET_ERROR_TYPE_ERROR, "gcry_mpi_scan", rc);
909 range = -1; // signal error with product-length = 0 and range = -1
911 gcry_mpi_release (value);
914 msg_length = sizeof (struct GNUNET_SCALARPRODUCT_client_response) +product_length;
915 msg = GNUNET_malloc (msg_length);
916 msg->key = session->key;
917 msg->peer = session->peer;
918 if (product_exported != NULL)
920 memcpy (&msg[1], product_exported, product_length);
921 GNUNET_free (product_exported);
923 msg->header.type = htons (GNUNET_MESSAGE_TYPE_SCALARPRODUCT_SERVICE_TO_CLIENT);
924 msg->header.size = htons (msg_length);
926 msg->product_length = htonl (product_length);
928 session->msg = (struct GNUNET_MessageHeader *) msg;
929 //transmit this message to our client
930 session->client_transmit_handle =
931 GNUNET_SERVER_notify_transmit_ready (session->client,
933 GNUNET_TIME_UNIT_FOREVER_REL,
936 if (NULL == session->client_transmit_handle) {
937 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
938 _ ("Could not send message to client (%p)!\n"),
940 session->client = NULL;
941 // callback was not called!
946 // gracefully sent message, just terminate session structure
947 GNUNET_log (GNUNET_ERROR_TYPE_INFO,
948 _ ("Sent result to client (%p), this session (%s) has ended!\n"),
950 GNUNET_h2s (&session->key));
951 free_session_variables (session);
956 * Send a multipart chunk of a service response from bob to alice.
957 * This element only contains the two permutations of R, R'.
959 * @param cls the associated service session
962 prepare_service_response_multipart (void *cls)
964 struct ServiceSession * session = cls;
965 unsigned char * current;
966 unsigned char * element_exported;
967 struct GNUNET_SCALARPRODUCT_multipart_message * msg;
971 size_t element_length = 0; // initialized by gcry_mpi_print, but the compiler doesn't know that
973 msg_length = sizeof (struct GNUNET_SCALARPRODUCT_multipart_message);
974 todo_count = session->used - session->transferred;
976 if (todo_count > MULTIPART_ELEMENT_CAPACITY / 2)
977 // send the currently possible maximum chunk, we always transfer both permutations
978 todo_count = MULTIPART_ELEMENT_CAPACITY / 2;
980 msg_length += todo_count * PAILLIER_ELEMENT_LENGTH * 2;
981 msg = GNUNET_malloc (msg_length);
982 msg->header.type = htons (GNUNET_MESSAGE_TYPE_SCALARPRODUCT_ALICE_TO_BOB_MULTIPART);
983 msg->header.size = htons (msg_length);
984 msg->multipart_element_count = htonl (todo_count);
986 element_exported = GNUNET_malloc (PAILLIER_ELEMENT_LENGTH);
987 current = (unsigned char *) &msg[1];
989 for (i = session->transferred; i < session->transferred + todo_count; i++) {
991 memset (element_exported, 0, PAILLIER_ELEMENT_LENGTH);
992 GNUNET_assert (0 == gcry_mpi_print (GCRYMPI_FMT_USG,
993 element_exported, PAILLIER_ELEMENT_LENGTH,
996 adjust (element_exported, element_length, PAILLIER_ELEMENT_LENGTH);
997 memcpy (current, element_exported, PAILLIER_ELEMENT_LENGTH);
998 current += PAILLIER_ELEMENT_LENGTH;
1000 memset (element_exported, 0, PAILLIER_ELEMENT_LENGTH);
1001 GNUNET_assert (0 == gcry_mpi_print (GCRYMPI_FMT_USG,
1002 element_exported, PAILLIER_ELEMENT_LENGTH,
1004 session->r_prime[i]));
1005 adjust (element_exported, element_length, PAILLIER_ELEMENT_LENGTH);
1006 memcpy (current, element_exported, PAILLIER_ELEMENT_LENGTH);
1007 current += PAILLIER_ELEMENT_LENGTH;
1009 GNUNET_free (element_exported);
1010 for (i = session->transferred; i < session->transferred; i++) {
1011 gcry_mpi_release (session->r_prime[i]);
1012 session->r_prime[i] = NULL;
1013 gcry_mpi_release (session->r[i]);
1014 session->r[i] = NULL;
1016 session->transferred += todo_count;
1017 session->msg = (struct GNUNET_MessageHeader *) msg;
1018 session->service_transmit_handle =
1019 GNUNET_MESH_notify_transmit_ready (session->channel,
1021 GNUNET_TIME_UNIT_FOREVER_REL,
1025 //disconnect our client
1026 if (NULL == session->service_transmit_handle) {
1027 GNUNET_log (GNUNET_ERROR_TYPE_ERROR, _ ("Could not send service-response message via mesh!)\n"));
1028 session->state = FINALIZED;
1030 session->response->client_notification_task =
1031 GNUNET_SCHEDULER_add_now (&prepare_client_end_notification,
1035 if (session->transferred != session->used)
1037 session->state = WAITING_FOR_MULTIPART_TRANSMISSION;
1040 session->state = FINALIZED;
1041 GNUNET_free(session->r);
1042 GNUNET_free(session->r_prime);
1043 session->r_prime = NULL;
1051 * generates the response message to be sent to alice after computing
1052 * the values (1), (2), S and S'
1053 * (1)[]: $E_A(a_{pi(i)}) times E_A(- r_{pi(i)} - b_{pi(i)}) &= E_A(a_{pi(i)} - r_{pi(i)} - b_{pi(i)})$
1054 * (2)[]: $E_A(a_{pi'(i)}) times E_A(- r_{pi'(i)}) &= E_A(a_{pi'(i)} - r_{pi'(i)})$
1055 * S: $S := E_A(sum (r_i + b_i)^2)$
1056 * S': $S' := E_A(sum r_i^2)$
1058 * @param s S: $S := E_A(sum (r_i + b_i)^2)$
1059 * @param s_prime S': $S' := E_A(sum r_i^2)$
1060 * @param session the associated requesting session with alice
1061 * @return #GNUNET_NO if we could not send our message
1062 * #GNUNET_OK if the operation succeeded
1065 prepare_service_response (gcry_mpi_t s,
1067 struct ServiceSession * session)
1069 struct GNUNET_SCALARPRODUCT_service_response * msg;
1070 uint32_t msg_length = 0;
1071 unsigned char * current = NULL;
1072 unsigned char * element_exported = NULL;
1073 size_t element_length = 0;
1076 msg_length = sizeof (struct GNUNET_SCALARPRODUCT_service_response)
1077 + 2 * PAILLIER_ELEMENT_LENGTH; // s, stick
1079 if (GNUNET_SERVER_MAX_MESSAGE_SIZE > msg_length + 2 * session->used * PAILLIER_ELEMENT_LENGTH) { //kp, kq
1080 msg_length += +2 * session->used * PAILLIER_ELEMENT_LENGTH;
1081 session->transferred = session->used;
1084 session->transferred = (GNUNET_SERVER_MAX_MESSAGE_SIZE - 1 - msg_length) / (PAILLIER_ELEMENT_LENGTH * 2);
1087 msg = GNUNET_malloc (msg_length);
1089 msg->header.type = htons (GNUNET_MESSAGE_TYPE_SCALARPRODUCT_BOB_TO_ALICE);
1090 msg->header.size = htons (msg_length);
1091 msg->total_element_count = htonl (session->total);
1092 msg->used_element_count = htonl (session->used);
1093 msg->contained_element_count = htonl (session->transferred);
1094 memcpy (&msg->key, &session->key, sizeof (struct GNUNET_HashCode));
1095 current = (unsigned char *) &msg[1];
1097 element_exported = GNUNET_malloc (PAILLIER_ELEMENT_LENGTH);
1098 // 4 times the same logics with slight variations.
1099 // doesn't really justify having 2 functions for that
1100 // so i put it into blocks to enhance readability
1102 memset (element_exported, 0, PAILLIER_ELEMENT_LENGTH);
1103 GNUNET_assert (0 == gcry_mpi_print (GCRYMPI_FMT_USG,
1104 element_exported, PAILLIER_ELEMENT_LENGTH,
1107 adjust (element_exported, element_length, PAILLIER_ELEMENT_LENGTH);
1108 memcpy (current, element_exported, PAILLIER_ELEMENT_LENGTH);
1109 current += PAILLIER_ELEMENT_LENGTH;
1112 memset (element_exported, 0, PAILLIER_ELEMENT_LENGTH);
1113 GNUNET_assert (0 == gcry_mpi_print (GCRYMPI_FMT_USG,
1114 element_exported, PAILLIER_ELEMENT_LENGTH,
1117 adjust (element_exported, element_length, PAILLIER_ELEMENT_LENGTH);
1118 memcpy (current, element_exported, PAILLIER_ELEMENT_LENGTH);
1119 current += PAILLIER_ELEMENT_LENGTH;
1122 for (i = 0; i < session->transferred; i++) {
1124 memset (element_exported, 0, PAILLIER_ELEMENT_LENGTH);
1125 GNUNET_assert (0 == gcry_mpi_print (GCRYMPI_FMT_USG,
1126 element_exported, PAILLIER_ELEMENT_LENGTH,
1129 adjust (element_exported, element_length, PAILLIER_ELEMENT_LENGTH);
1130 memcpy (current, element_exported, PAILLIER_ELEMENT_LENGTH);
1131 current += PAILLIER_ELEMENT_LENGTH;
1133 memset (element_exported, 0, PAILLIER_ELEMENT_LENGTH);
1134 GNUNET_assert (0 == gcry_mpi_print (GCRYMPI_FMT_USG,
1135 element_exported, PAILLIER_ELEMENT_LENGTH,
1137 session->r_prime[i]));
1138 adjust (element_exported, element_length, PAILLIER_ELEMENT_LENGTH);
1139 memcpy (current, element_exported, PAILLIER_ELEMENT_LENGTH);
1140 current += PAILLIER_ELEMENT_LENGTH;
1143 GNUNET_free (element_exported);
1144 for (i = 0; i < session->transferred; i++) {
1145 gcry_mpi_release (session->r_prime[i]);
1146 session->r_prime[i] = NULL;
1147 gcry_mpi_release (session->r[i]);
1148 session->r[i] = NULL;
1150 gcry_mpi_release (s);
1152 gcry_mpi_release (s_prime);
1153 session->s_prime = NULL;
1155 session->msg = (struct GNUNET_MessageHeader *) msg;
1156 session->service_transmit_handle =
1157 GNUNET_MESH_notify_transmit_ready (session->channel,
1159 GNUNET_TIME_UNIT_FOREVER_REL,
1163 //disconnect our client
1164 if (NULL == session->service_transmit_handle) {
1165 GNUNET_log (GNUNET_ERROR_TYPE_ERROR, _ ("Could not send service-response message via mesh!)\n"));
1166 session->state = FINALIZED;
1168 session->response->client_notification_task =
1169 GNUNET_SCHEDULER_add_now (&prepare_client_end_notification,
1173 if (session->transferred != session->used)
1175 session->state = WAITING_FOR_MULTIPART_TRANSMISSION;
1178 session->state = FINALIZED;
1179 GNUNET_free(session->r);
1180 GNUNET_free(session->r_prime);
1181 session->r_prime = NULL;
1191 * compute the values
1192 * (1)[]: $E_A(a_{pi(i)}) otimes E_A(- r_{pi(i)} - b_{pi(i)}) &= E_A(a_{pi(i)} - r_{pi(i)} - b_{pi(i)})$
1193 * (2)[]: $E_A(a_{pi'(i)}) otimes E_A(- r_{pi'(i)}) &= E_A(a_{pi'(i)} - r_{pi'(i)})$
1194 * S: $S := E_A(sum (r_i + b_i)^2)$
1195 * S': $S' := E_A(sum r_i^2)$
1197 * @param request the requesting session + bob's requesting peer
1198 * @param response the responding session + bob's client handle
1199 * @return GNUNET_SYSERR if the computation failed
1200 * GNUNET_OK if everything went well.
1203 compute_service_response (struct ServiceSession * request,
1204 struct ServiceSession * response)
1208 int ret = GNUNET_SYSERR;
1212 gcry_mpi_t * rand = NULL;
1213 gcry_mpi_t * r = NULL;
1214 gcry_mpi_t * r_prime = NULL;
1217 gcry_mpi_t * a_pi_prime;
1219 gcry_mpi_t * rand_pi;
1220 gcry_mpi_t * rand_pi_prime;
1221 gcry_mpi_t s = NULL;
1222 gcry_mpi_t s_prime = NULL;
1223 gcry_mpi_t remote_n = NULL;
1224 gcry_mpi_t remote_nsquare;
1225 gcry_mpi_t remote_g = NULL;
1226 gcry_sexp_t tmp_exp;
1229 count = request->used;
1231 b = GNUNET_malloc (sizeof (gcry_mpi_t) * count);
1232 a_pi = GNUNET_malloc (sizeof (gcry_mpi_t) * count);
1233 b_pi = GNUNET_malloc (sizeof (gcry_mpi_t) * count);
1234 a_pi_prime = GNUNET_malloc (sizeof (gcry_mpi_t) * count);
1235 rand_pi = GNUNET_malloc (sizeof (gcry_mpi_t) * count);
1236 rand_pi_prime = GNUNET_malloc (sizeof (gcry_mpi_t) * count);
1238 // convert responder session to from long to mpi
1239 for (i = 0, j = 0; i < response->total && j < count; i++)
1241 if (request->mask[i / 8] & (1 << (i % 8)))
1243 value = response->vector[i] >= 0 ? response->vector[i] : -response->vector[i];
1244 // long to gcry_mpi_t
1245 if (0 > response->vector[i])
1247 b[j] = gcry_mpi_new (0);
1248 gcry_mpi_sub_ui (b[j], b[j], value);
1251 b[j] = gcry_mpi_set_ui (NULL, value);
1256 GNUNET_free (response->vector);
1257 response->vector = NULL;
1260 tmp_exp = gcry_sexp_find_token (request->remote_pubkey, "n", 0);
1263 GNUNET_break_op (0);
1264 gcry_sexp_release (request->remote_pubkey);
1265 request->remote_pubkey = NULL;
1268 remote_n = gcry_sexp_nth_mpi (tmp_exp, 1, GCRYMPI_FMT_USG);
1272 gcry_sexp_release (tmp_exp);
1275 remote_nsquare = gcry_mpi_new (KEYBITS + 1);
1276 gcry_mpi_mul (remote_nsquare, remote_n, remote_n);
1277 gcry_sexp_release (tmp_exp);
1278 tmp_exp = gcry_sexp_find_token (request->remote_pubkey, "g", 0);
1279 gcry_sexp_release (request->remote_pubkey);
1280 request->remote_pubkey = NULL;
1283 GNUNET_break_op (0);
1284 gcry_mpi_release (remote_n);
1287 remote_g = gcry_sexp_nth_mpi (tmp_exp, 1, GCRYMPI_FMT_USG);
1291 gcry_mpi_release (remote_n);
1292 gcry_sexp_release (tmp_exp);
1295 gcry_sexp_release (tmp_exp);
1297 // generate r, p and q
1298 rand = initialize_mpi_vector (count);
1299 for (i = 0; i < count; i++)
1303 svalue = (int32_t) GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK, UINT32_MAX);
1305 // long to gcry_mpi_t
1307 gcry_mpi_sub_ui (rand[i],
1311 rand[i] = gcry_mpi_set_ui (rand[i], svalue);
1313 p = GNUNET_CRYPTO_random_permute (GNUNET_CRYPTO_QUALITY_WEAK, count);
1314 q = GNUNET_CRYPTO_random_permute (GNUNET_CRYPTO_QUALITY_WEAK, count);
1315 //initialize the result vectors
1316 r = initialize_mpi_vector (count);
1317 r_prime = initialize_mpi_vector (count);
1319 // copy the REFERNCES of a, b and r into aq and bq. we will not change
1320 // those values, thus we can work with the references
1321 memcpy (a_pi, request->a, sizeof (gcry_mpi_t) * count);
1322 memcpy (a_pi_prime, request->a, sizeof (gcry_mpi_t) * count);
1323 memcpy (b_pi, b, sizeof (gcry_mpi_t) * count);
1324 memcpy (rand_pi, rand, sizeof (gcry_mpi_t) * count);
1325 memcpy (rand_pi_prime, rand, sizeof (gcry_mpi_t) * count);
1327 // generate p and q permutations for a, b and r
1328 GNUNET_assert (permute_vector (a_pi, p, count));
1329 GNUNET_assert (permute_vector (b_pi, p, count));
1330 GNUNET_assert (permute_vector (rand_pi, p, count));
1331 GNUNET_assert (permute_vector (a_pi_prime, q, count));
1332 GNUNET_assert (permute_vector (rand_pi_prime, q, count));
1334 // encrypt the element
1335 // for the sake of readability I decided to have dedicated permutation
1336 // vectors, which get rid of all the lookups in p/q.
1337 // however, ap/aq are not absolutely necessary but are just abstraction
1338 // Calculate Kp = E(S + a_pi) (+) E(S - r_pi - b_pi)
1339 for (i = 0; i < count; i++)
1341 // E(S - r_pi - b_pi)
1342 gcry_mpi_sub (r[i], my_offset, rand_pi[i]);
1343 gcry_mpi_sub (r[i], r[i], b_pi[i]);
1344 encrypt_element (r[i], r[i], remote_g, remote_n, remote_nsquare);
1346 // E(S - r_pi - b_pi) * E(S + a_pi) == E(2*S + a - r - b)
1347 gcry_mpi_mulm (r[i], r[i], a_pi[i], remote_nsquare);
1351 GNUNET_free (rand_pi);
1353 // Calculate Kq = E(S + a_qi) (+) E(S - r_qi)
1354 for (i = 0; i < count; i++)
1357 gcry_mpi_sub (r_prime[i], my_offset, rand_pi_prime[i]);
1358 encrypt_element (r_prime[i], r_prime[i], remote_g, remote_n, remote_nsquare);
1360 // E(S - r_qi) * E(S + a_qi) == E(2*S + a_qi - r_qi)
1361 gcry_mpi_mulm (r_prime[i], r_prime[i], a_pi_prime[i], remote_nsquare);
1363 GNUNET_free (a_pi_prime);
1364 GNUNET_free (rand_pi_prime);
1367 request->r_prime = r_prime;
1368 request->response = response;
1370 // Calculate S' = E(SUM( r_i^2 ))
1371 s_prime = compute_square_sum (rand, count);
1372 encrypt_element (s_prime, s_prime, remote_g, remote_n, remote_nsquare);
1374 // Calculate S = E(SUM( (r_i + b_i)^2 ))
1375 for (i = 0; i < count; i++) {
1376 gcry_mpi_add (rand[i], rand[i], b[i]);
1378 s = compute_square_sum (rand, count);
1379 encrypt_element (s, s, remote_g, remote_n, remote_nsquare);
1380 gcry_mpi_release (remote_n);
1381 gcry_mpi_release (remote_g);
1382 gcry_mpi_release (remote_nsquare);
1384 // release r and tmp
1385 for (i = 0; i < count; i++)
1386 // rp, rq, aq, ap, bp, bq are released along with a, r, b respectively, (a and b are handled at except:)
1387 gcry_mpi_release (rand[i]);
1389 // copy the r[], r_prime[], S and Stick into a new message, prepare_service_response frees these
1390 if (GNUNET_YES != prepare_service_response (s, s_prime, request))
1391 GNUNET_log (GNUNET_ERROR_TYPE_INFO, _ ("Failed to communicate with `%s', scalar product calculation aborted.\n"),
1392 GNUNET_i2s (&request->peer));
1397 for (i = 0; i < count; i++)
1399 gcry_mpi_release (b[i]);
1400 gcry_mpi_release (request->a[i]);
1404 GNUNET_free (request->a);
1406 GNUNET_free_non_null (p);
1407 GNUNET_free_non_null (q);
1414 * Send a multi part chunk of a service request from alice to bob.
1415 * This element only contains a part of the elements-vector (session->a[]),
1416 * mask and public key set have to be contained within the first message
1418 * This allows a ~32kbit key length while using 32000 elements or 62000 elements per request.
1420 * @param cls the associated service session
1423 prepare_service_request_multipart (void *cls)
1425 struct ServiceSession * session = cls;
1426 unsigned char * current;
1427 unsigned char * element_exported;
1428 struct GNUNET_SCALARPRODUCT_multipart_message * msg;
1431 uint32_t msg_length;
1432 uint32_t todo_count;
1433 size_t element_length = 0; // initialized by gcry_mpi_print, but the compiler doesn't know that
1437 msg_length = sizeof (struct GNUNET_SCALARPRODUCT_multipart_message);
1438 todo_count = session->used - session->transferred;
1440 if (todo_count > MULTIPART_ELEMENT_CAPACITY)
1441 // send the currently possible maximum chunk
1442 todo_count = MULTIPART_ELEMENT_CAPACITY;
1444 msg_length += todo_count * PAILLIER_ELEMENT_LENGTH;
1445 msg = GNUNET_malloc (msg_length);
1446 msg->header.type = htons (GNUNET_MESSAGE_TYPE_SCALARPRODUCT_ALICE_TO_BOB_MULTIPART);
1447 msg->header.size = htons (msg_length);
1448 msg->multipart_element_count = htonl (todo_count);
1450 element_exported = GNUNET_malloc (PAILLIER_ELEMENT_LENGTH);
1451 a = gcry_mpi_new (KEYBITS * 2);
1452 current = (unsigned char *) &msg[1];
1453 // encrypt our vector and generate string representations
1454 for (i = session->last_processed, j = 0; i < session->total; i++)
1456 // is this a used element?
1457 if (session->mask[i / 8] & 1 << (i % 8)) {
1458 if (todo_count <= j)
1459 break; //reached end of this message, can't include more
1461 memset (element_exported, 0, PAILLIER_ELEMENT_LENGTH);
1462 value = session->vector[i] >= 0 ? session->vector[i] : -session->vector[i];
1464 a = gcry_mpi_set_ui (a, 0);
1465 // long to gcry_mpi_t
1466 if (session->vector[i] < 0)
1467 gcry_mpi_sub_ui (a, a, value);
1469 gcry_mpi_add_ui (a, a, value);
1471 session->a[session->transferred + j++] = gcry_mpi_set (NULL, a);
1472 gcry_mpi_add (a, a, my_offset);
1473 encrypt_element (a, a, my_g, my_n, my_nsquare);
1475 // get representation as string
1476 // we always supply some value, so gcry_mpi_print fails only if it can't reserve memory
1477 GNUNET_assert (!gcry_mpi_print (GCRYMPI_FMT_USG,
1478 element_exported, PAILLIER_ELEMENT_LENGTH,
1482 // move buffer content to the end of the buffer so it can easily be read by libgcrypt. also this now has fixed size
1483 adjust (element_exported, element_length, PAILLIER_ELEMENT_LENGTH);
1485 // copy over to the message
1486 memcpy (current, element_exported, PAILLIER_ELEMENT_LENGTH);
1487 current += PAILLIER_ELEMENT_LENGTH;
1490 gcry_mpi_release (a);
1491 GNUNET_free (element_exported);
1492 session->transferred += todo_count;
1494 session->msg = (struct GNUNET_MessageHeader *) msg;
1495 GNUNET_log (GNUNET_ERROR_TYPE_INFO, _ ("Transmitting service request.\n"));
1497 //transmit via mesh messaging
1498 session->service_transmit_handle = GNUNET_MESH_notify_transmit_ready (session->channel, GNUNET_YES,
1499 GNUNET_TIME_UNIT_FOREVER_REL,
1503 if (!session->service_transmit_handle) {
1504 GNUNET_log (GNUNET_ERROR_TYPE_ERROR, _ ("Could not send service-request multipart message to channel!\n"));
1506 session->msg = NULL;
1507 session->client_notification_task =
1508 GNUNET_SCHEDULER_add_now (&prepare_client_end_notification,
1512 if (session->transferred != session->used) {
1513 session->last_processed = i;
1517 session->state = WAITING_FOR_SERVICE_RESPONSE;
1522 * Executed by Alice, fills in a service-request message and sends it to the given peer
1524 * @param cls the session associated with this request
1525 * @param tc task context handed over by scheduler, unsued
1528 prepare_service_request (void *cls,
1529 const struct GNUNET_SCHEDULER_TaskContext *tc)
1531 struct ServiceSession * session = cls;
1532 unsigned char * current;
1533 unsigned char * element_exported;
1534 struct GNUNET_SCALARPRODUCT_service_request * msg;
1537 uint32_t msg_length;
1538 size_t element_length = 0; // initialized by gcry_mpi_print, but the compiler doesn't know that
1542 session->service_request_task = GNUNET_SCHEDULER_NO_TASK;
1544 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, _ ("Successfully created new channel to peer (%s)!\n"), GNUNET_i2s (&session->peer));
1546 msg_length = sizeof (struct GNUNET_SCALARPRODUCT_service_request)
1547 +session->mask_length
1548 + my_pubkey_external_length;
1550 if (GNUNET_SERVER_MAX_MESSAGE_SIZE > msg_length + session->used * PAILLIER_ELEMENT_LENGTH) {
1551 msg_length += session->used * PAILLIER_ELEMENT_LENGTH;
1552 session->transferred = session->used;
1555 //create a multipart msg, first we calculate a new msg size for the head msg
1556 session->transferred = (GNUNET_SERVER_MAX_MESSAGE_SIZE - 1 - msg_length) / PAILLIER_ELEMENT_LENGTH;
1559 msg = GNUNET_malloc (msg_length);
1560 msg->header.type = htons (GNUNET_MESSAGE_TYPE_SCALARPRODUCT_ALICE_TO_BOB);
1561 msg->total_element_count = htonl (session->used);
1562 msg->contained_element_count = htonl (session->transferred);
1563 memcpy (&msg->key, &session->key, sizeof (struct GNUNET_HashCode));
1564 msg->mask_length = htonl (session->mask_length);
1565 msg->pk_length = htonl (my_pubkey_external_length);
1566 msg->element_count = htonl (session->total);
1567 msg->header.size = htons (msg_length);
1569 // fill in the payload
1570 current = (unsigned char *) &msg[1];
1571 // copy over the mask
1572 memcpy (current, session->mask, session->mask_length);
1573 // copy over our public key
1574 current += session->mask_length;
1575 memcpy (current, my_pubkey_external, my_pubkey_external_length);
1576 current += my_pubkey_external_length;
1578 // now copy over the element vector
1579 element_exported = GNUNET_malloc (PAILLIER_ELEMENT_LENGTH);
1580 session->a = GNUNET_malloc (sizeof (gcry_mpi_t) * session->used);
1581 a = gcry_mpi_new (KEYBITS * 2);
1582 // encrypt our vector and generate string representations
1583 for (i = 0, j = 0; i < session->total; i++) {
1584 // if this is a used element...
1585 if (session->mask[i / 8] & 1 << (i % 8)) {
1586 if (session->transferred <= j)
1587 break; //reached end of this message, can't include more
1589 memset (element_exported, 0, PAILLIER_ELEMENT_LENGTH);
1590 value = session->vector[i] >= 0 ? session->vector[i] : -session->vector[i];
1592 a = gcry_mpi_set_ui (a, 0);
1593 // long to gcry_mpi_t
1594 if (session->vector[i] < 0)
1595 gcry_mpi_sub_ui (a, a, value);
1597 gcry_mpi_add_ui (a, a, value);
1599 session->a[j++] = gcry_mpi_set (NULL, a);
1600 gcry_mpi_add (a, a, my_offset);
1601 encrypt_element (a, a, my_g, my_n, my_nsquare);
1603 // get representation as string
1604 // we always supply some value, so gcry_mpi_print fails only if it can't reserve memory
1605 GNUNET_assert (!gcry_mpi_print (GCRYMPI_FMT_USG,
1606 element_exported, PAILLIER_ELEMENT_LENGTH,
1610 // move buffer content to the end of the buffer so it can easily be read by libgcrypt. also this now has fixed size
1611 adjust (element_exported, element_length, PAILLIER_ELEMENT_LENGTH);
1613 // copy over to the message
1614 memcpy (current, element_exported, PAILLIER_ELEMENT_LENGTH);
1615 current += PAILLIER_ELEMENT_LENGTH;
1618 gcry_mpi_release (a);
1619 GNUNET_free (element_exported);
1621 session->msg = (struct GNUNET_MessageHeader *) msg;
1622 GNUNET_log (GNUNET_ERROR_TYPE_INFO, _ ("Transmitting service request.\n"));
1624 //transmit via mesh messaging
1625 session->service_transmit_handle = GNUNET_MESH_notify_transmit_ready (session->channel, GNUNET_YES,
1626 GNUNET_TIME_UNIT_FOREVER_REL,
1630 if (!session->service_transmit_handle) {
1631 GNUNET_log (GNUNET_ERROR_TYPE_ERROR, _ ("Could not send message to channel!\n"));
1633 session->msg = NULL;
1634 session->client_notification_task =
1635 GNUNET_SCHEDULER_add_now (&prepare_client_end_notification,
1639 if (session->transferred != session->used) {
1640 session->state = WAITING_FOR_MULTIPART_TRANSMISSION;
1641 session->last_processed = i;
1644 //singlepart message
1645 session->state = WAITING_FOR_SERVICE_RESPONSE;
1650 * Handler for a client request message.
1651 * Can either be type A or B
1652 * A: request-initiation to compute a scalar product with a peer
1653 * B: response role, keep the values + session and wait for a matching session or process a waiting request
1655 * @param cls closure
1656 * @param client identification of the client
1657 * @param message the actual message
1660 handle_client_request (void *cls,
1661 struct GNUNET_SERVER_Client *client,
1662 const struct GNUNET_MessageHeader *message)
1664 const struct GNUNET_SCALARPRODUCT_client_request * msg = (const struct GNUNET_SCALARPRODUCT_client_request *) message;
1665 struct ServiceSession * session;
1666 uint32_t element_count;
1667 uint32_t mask_length;
1672 // only one concurrent session per client connection allowed, simplifies logics a lot...
1673 session = GNUNET_SERVER_client_get_user_context (client, struct ServiceSession);
1674 if ((NULL != session) && (session->state != FINALIZED)) {
1675 GNUNET_SERVER_receive_done (client, GNUNET_OK);
1678 else if (NULL != session) {
1679 // old session is already completed, clean it up
1680 GNUNET_CONTAINER_DLL_remove (from_client_head, from_client_tail, session);
1681 free_session_variables (session);
1682 GNUNET_free (session);
1685 //we need at least a peer and one message id to compare
1686 if (sizeof (struct GNUNET_SCALARPRODUCT_client_request) > ntohs (msg->header.size)) {
1687 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
1688 _ ("Too short message received from client!\n"));
1689 GNUNET_SERVER_receive_done (client, GNUNET_SYSERR);
1693 msg_type = ntohs (msg->header.type);
1694 element_count = ntohl (msg->element_count);
1695 mask_length = ntohl (msg->mask_length);
1697 //sanity check: is the message as long as the message_count fields suggests?
1698 if ((ntohs (msg->header.size) != (sizeof (struct GNUNET_SCALARPRODUCT_client_request) +element_count * sizeof (int32_t) + mask_length))
1699 || (0 == element_count)) {
1700 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
1701 _("Invalid message received from client, session information incorrect!\n"));
1702 GNUNET_SERVER_receive_done (client, GNUNET_SYSERR);
1706 // do we have a duplicate session here already?
1707 if (NULL != find_matching_session (from_client_tail,
1711 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
1712 _("Duplicate session information received, cannot create new session with key `%s'\n"),
1713 GNUNET_h2s (&msg->key));
1714 GNUNET_SERVER_receive_done (client, GNUNET_SYSERR);
1718 session = GNUNET_new (struct ServiceSession);
1719 session->service_request_task = GNUNET_SCHEDULER_NO_TASK;
1720 session->client_notification_task = GNUNET_SCHEDULER_NO_TASK;
1721 session->client = client;
1722 session->total = element_count;
1723 session->mask_length = mask_length;
1724 // get our transaction key
1725 memcpy (&session->key, &msg->key, sizeof (struct GNUNET_HashCode));
1726 //allocate memory for vector and encrypted vector
1727 session->vector = GNUNET_malloc (sizeof (int32_t) * element_count);
1728 vector = (int32_t *) & msg[1];
1730 if (GNUNET_MESSAGE_TYPE_SCALARPRODUCT_CLIENT_TO_ALICE == msg_type)
1732 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1733 _("Got client-request-session with key %s, preparing channel to remote service.\n"),
1734 GNUNET_h2s (&session->key));
1736 session->role = ALICE;
1738 session->mask = GNUNET_malloc (mask_length);
1739 memcpy (session->mask, &vector[element_count], mask_length);
1741 // copy over the elements
1743 for (i = 0; i < element_count; i++)
1745 session->vector[i] = ntohl (vector[i]);
1746 if (session->vector[i] == 0)
1747 session->mask[i / 8] &= ~(1 << (i % 8));
1748 if (session->mask[i / 8] & (1 << (i % 8)))
1752 if (0 == session->used)
1754 GNUNET_break_op (0);
1755 GNUNET_free (session->vector);
1756 GNUNET_free (session);
1757 GNUNET_SERVER_receive_done (client, GNUNET_SYSERR);
1760 //session with ourself makes no sense!
1761 if (!memcmp (&msg->peer, &me, sizeof (struct GNUNET_PeerIdentity)))
1764 GNUNET_free (session->vector);
1765 GNUNET_free (session);
1766 GNUNET_SERVER_receive_done (client, GNUNET_SYSERR);
1770 memcpy (&session->peer, &msg->peer, sizeof (struct GNUNET_PeerIdentity));
1771 GNUNET_log (GNUNET_ERROR_TYPE_INFO,
1772 _ ("Creating new channel for session with key %s.\n"),
1773 GNUNET_h2s (&session->key));
1774 session->channel = GNUNET_MESH_channel_create (my_mesh, session,
1776 GNUNET_APPLICATION_TYPE_SCALARPRODUCT,
1777 GNUNET_MESH_OPTION_RELIABLE);
1778 //prepare_service_request, channel_peer_disconnect_handler,
1779 if (!session->channel) {
1781 GNUNET_free (session->vector);
1782 GNUNET_free (session);
1783 GNUNET_SERVER_receive_done (client, GNUNET_SYSERR);
1786 GNUNET_SERVER_client_set_user_context (client, session);
1787 GNUNET_CONTAINER_DLL_insert (from_client_head, from_client_tail, session);
1789 session->state = CLIENT_REQUEST_RECEIVED;
1790 session->service_request_task =
1791 GNUNET_SCHEDULER_add_now (&prepare_service_request,
1797 struct ServiceSession * requesting_session;
1798 enum SessionState needed_state = SERVICE_REQUEST_RECEIVED;
1800 session->role = BOB;
1801 session->mask = NULL;
1802 // copy over the elements
1803 session->used = element_count;
1804 for (i = 0; i < element_count; i++)
1805 session->vector[i] = ntohl (vector[i]);
1806 session->state = CLIENT_RESPONSE_RECEIVED;
1808 GNUNET_SERVER_client_set_user_context (client, session);
1809 GNUNET_CONTAINER_DLL_insert (from_client_head, from_client_tail, session);
1811 //check if service queue contains a matching request
1812 requesting_session = find_matching_session (from_service_tail,
1815 &needed_state, NULL);
1816 if (NULL != requesting_session)
1818 GNUNET_log (GNUNET_ERROR_TYPE_INFO,
1819 _("Got client-responder-session with key %s and a matching service-request-session set, processing.\n"),
1820 GNUNET_h2s (&session->key));
1821 if (GNUNET_OK != compute_service_response (requesting_session, session))
1822 session->client_notification_task =
1823 GNUNET_SCHEDULER_add_now (&prepare_client_end_notification,
1829 GNUNET_log (GNUNET_ERROR_TYPE_INFO,
1830 _("Got client-responder-session with key %s but NO matching service-request-session set, queuing element for later use.\n"),
1831 GNUNET_h2s (&session->key));
1832 // no matching session exists yet, store the response
1833 // for later processing by handle_service_request()
1836 GNUNET_SERVER_receive_done (client, GNUNET_YES);
1841 * Function called for inbound channels.
1843 * @param cls closure
1844 * @param channel new handle to the channel
1845 * @param initiator peer that started the channel
1846 * @param port unused
1847 * @param options unused
1849 * @return session associated with the channel
1852 channel_incoming_handler (void *cls,
1853 struct GNUNET_MESH_Channel *channel,
1854 const struct GNUNET_PeerIdentity *initiator,
1855 uint32_t port, enum GNUNET_MESH_ChannelOption options)
1857 struct ServiceSession * c = GNUNET_new (struct ServiceSession);
1859 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1860 _("New incoming channel from peer %s.\n"),
1861 GNUNET_i2s (initiator));
1863 c->peer = *initiator;
1864 c->channel = channel;
1866 c->state = WAITING_FOR_SERVICE_REQUEST;
1872 * Function called whenever a channel is destroyed. Should clean up
1873 * any associated state.
1875 * It must NOT call GNUNET_MESH_channel_destroy on the channel.
1877 * @param cls closure (set from GNUNET_MESH_connect)
1878 * @param channel connection to the other end (henceforth invalid)
1879 * @param channel_ctx place where local state associated
1880 * with the channel is stored
1883 channel_destruction_handler (void *cls,
1884 const struct GNUNET_MESH_Channel *channel,
1887 struct ServiceSession * session = channel_ctx;
1888 struct ServiceSession * client_session;
1889 struct ServiceSession * curr;
1891 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1892 _ ("Peer disconnected, terminating session %s with peer (%s)\n"),
1893 GNUNET_h2s (&session->key),
1894 GNUNET_i2s (&session->peer));
1895 if (ALICE == session->role) {
1896 // as we have only one peer connected in each session, just remove the session
1898 if ((SERVICE_RESPONSE_RECEIVED > session->state) && (!do_shutdown)) {
1899 session->channel = NULL;
1900 // if this happened before we received the answer, we must terminate the session
1901 session->client_notification_task =
1902 GNUNET_SCHEDULER_add_now (&prepare_client_end_notification,
1906 else { //(BOB == session->role) service session
1907 // remove the session, unless it has already been dequeued, but somehow still active
1908 // this could bug without the IF in case the queue is empty and the service session was the only one know to the service
1909 // scenario: disconnect before alice can send her message to bob.
1910 for (curr = from_service_head; NULL != curr; curr = curr->next)
1911 if (curr == session) {
1912 GNUNET_CONTAINER_DLL_remove (from_service_head, from_service_tail, curr);
1915 // there is a client waiting for this service session, terminate it, too!
1916 // i assume the tupel of key and element count is unique. if it was not the rest of the code would not work either.
1917 client_session = find_matching_session (from_client_tail,
1921 free_session_variables (session);
1922 GNUNET_free (session);
1924 // the client has to check if it was waiting for a result
1925 // or if it was a responder, no point in adding more statefulness
1926 if (client_session && (!do_shutdown)) {
1927 client_session->state = FINALIZED;
1928 client_session->client_notification_task =
1929 GNUNET_SCHEDULER_add_now (&prepare_client_end_notification,
1937 * Compute our scalar product, done by Alice
1939 * @param session - the session associated with this computation
1940 * @return product as MPI, never NULL
1943 compute_scalar_product (struct ServiceSession * session)
1954 count = session->used;
1955 // due to the introduced static offset S, we now also have to remove this
1956 // from the E(a_pi)(+)E(-b_pi-r_pi) and E(a_qi)(+)E(-r_qi) twice each,
1957 // the result is E((S + a_pi) + (S -b_pi-r_pi)) and E(S + a_qi + S - r_qi)
1958 for (i = 0; i < count; i++)
1960 decrypt_element (session->r[i], session->r[i], my_mu, my_lambda, my_n, my_nsquare);
1961 gcry_mpi_sub (session->r[i], session->r[i], my_offset);
1962 gcry_mpi_sub (session->r[i], session->r[i], my_offset);
1963 decrypt_element (session->r_prime[i], session->r_prime[i], my_mu, my_lambda, my_n, my_nsquare);
1964 gcry_mpi_sub (session->r_prime[i], session->r_prime[i], my_offset);
1965 gcry_mpi_sub (session->r_prime[i], session->r_prime[i], my_offset);
1968 // calculate t = sum(ai)
1969 t = compute_square_sum (session->a, count);
1972 u = gcry_mpi_new (0);
1973 tmp = compute_square_sum (session->r, count);
1974 gcry_mpi_sub (u, u, tmp);
1975 gcry_mpi_release (tmp);
1978 u_prime = gcry_mpi_new (0);
1979 tmp = compute_square_sum (session->r_prime, count);
1980 gcry_mpi_sub (u_prime, u_prime, tmp);
1982 GNUNET_assert (p = gcry_mpi_new (0));
1983 GNUNET_assert (p_prime = gcry_mpi_new (0));
1986 decrypt_element (session->s, session->s, my_mu, my_lambda, my_n, my_nsquare);
1987 decrypt_element (session->s_prime, session->s_prime, my_mu, my_lambda, my_n, my_nsquare);
1990 gcry_mpi_add (p, session->s, t);
1991 gcry_mpi_add (p, p, u);
1994 gcry_mpi_add (p_prime, session->s_prime, t);
1995 gcry_mpi_add (p_prime, p_prime, u_prime);
1997 gcry_mpi_release (t);
1998 gcry_mpi_release (u);
1999 gcry_mpi_release (u_prime);
2002 gcry_mpi_sub (p, p, p_prime);
2003 gcry_mpi_release (p_prime);
2004 tmp = gcry_mpi_set_ui (tmp, 2);
2005 gcry_mpi_div (p, NULL, p, tmp, 0);
2007 gcry_mpi_release (tmp);
2008 for (i = 0; i < count; i++)
2009 gcry_mpi_release (session->a[i]);
2010 GNUNET_free (session->a);
2018 * Handle a multipart-chunk of a request from another service to calculate a scalarproduct with us.
2020 * @param cls closure (set from #GNUNET_MESH_connect)
2021 * @param channel connection to the other end
2022 * @param channel_ctx place to store local state associated with the channel
2023 * @param message the actual message
2024 * @return #GNUNET_OK to keep the connection open,
2025 * #GNUNET_SYSERR to close it (signal serious error)
2028 handle_service_request_multipart (void *cls,
2029 struct GNUNET_MESH_Channel * channel,
2031 const struct GNUNET_MessageHeader * message)
2033 struct ServiceSession * session;
2034 const struct GNUNET_SCALARPRODUCT_multipart_message * msg = (const struct GNUNET_SCALARPRODUCT_multipart_message *) message;
2035 uint32_t used_elements;
2036 uint32_t contained_elements = 0;
2037 uint32_t msg_length;
2038 unsigned char * current;
2042 // are we in the correct state?
2043 session = (struct ServiceSession *) * channel_ctx;
2044 if ((BOB != session->role) || (WAITING_FOR_MULTIPART_TRANSMISSION != session->state)) {
2047 // shorter than minimum?
2048 if (ntohs (msg->header.size) <= sizeof (struct GNUNET_SCALARPRODUCT_multipart_message)) {
2051 used_elements = session->used;
2052 contained_elements = ntohl (msg->multipart_element_count);
2053 msg_length = sizeof (struct GNUNET_SCALARPRODUCT_multipart_message)
2054 +contained_elements * PAILLIER_ELEMENT_LENGTH;
2056 if ((ntohs (msg->header.size) != msg_length)
2057 || (used_elements < contained_elements + session->transferred)) {
2060 current = (unsigned char *) &msg[1];
2061 if (contained_elements != 0) {
2062 // Convert each vector element to MPI_value
2063 for (i = session->transferred; i < session->transferred + contained_elements; i++) {
2065 if (0 != (rc = gcry_mpi_scan (&session->a[i],
2067 ¤t[i * PAILLIER_ELEMENT_LENGTH],
2068 PAILLIER_ELEMENT_LENGTH,
2070 LOG_GCRY (GNUNET_ERROR_TYPE_DEBUG, "gcry_mpi_scan", rc);
2074 session->transferred += contained_elements;
2076 if (session->transferred == used_elements)
2078 // single part finished
2079 session->state = SERVICE_REQUEST_RECEIVED;
2080 if (session->response)
2082 GNUNET_log (GNUNET_ERROR_TYPE_INFO,
2083 _ ("Got session with key %s and a matching element set, processing.\n"),
2084 GNUNET_h2s (&session->key));
2085 if (GNUNET_OK != compute_service_response (session, session->response)) {
2086 //something went wrong, remove it again...
2091 GNUNET_log (GNUNET_ERROR_TYPE_INFO,
2092 _("Got session with key %s without a matching element set, queueing.\n"),
2093 GNUNET_h2s (&session->key));
2097 // multipart message
2103 // and notify our client-session that we could not complete the session
2104 GNUNET_CONTAINER_DLL_remove (from_service_head, from_service_tail, session);
2105 if (session->response)
2106 // we just found the responder session in this queue
2107 session->response->client_notification_task =
2108 GNUNET_SCHEDULER_add_now (&prepare_client_end_notification,
2110 free_session_variables (session);
2111 GNUNET_free (session);
2112 return GNUNET_SYSERR;
2117 * Handle a request from another service to calculate a scalarproduct with us.
2119 * @param cls closure (set from #GNUNET_MESH_connect)
2120 * @param channel connection to the other end
2121 * @param channel_ctx place to store local state associated with the channel
2122 * @param message the actual message
2123 * @return #GNUNET_OK to keep the connection open,
2124 * #GNUNET_SYSERR to close it (signal serious error)
2127 handle_service_request (void *cls,
2128 struct GNUNET_MESH_Channel * channel,
2130 const struct GNUNET_MessageHeader * message)
2132 struct ServiceSession * session;
2133 const struct GNUNET_SCALARPRODUCT_service_request * msg = (const struct GNUNET_SCALARPRODUCT_service_request *) message;
2134 uint32_t mask_length;
2136 uint32_t used_elements;
2137 uint32_t contained_elements = 0;
2138 uint32_t element_count;
2139 uint32_t msg_length;
2140 unsigned char * current;
2143 enum SessionState needed_state;
2145 session = (struct ServiceSession *) * channel_ctx;
2146 if (WAITING_FOR_SERVICE_REQUEST != session->state) {
2149 // Check if message was sent by me, which would be bad!
2150 if (!memcmp (&session->peer, &me, sizeof (struct GNUNET_PeerIdentity))) {
2151 GNUNET_free (session);
2153 return GNUNET_SYSERR;
2155 // shorter than expected?
2156 if (ntohs (msg->header.size) < sizeof (struct GNUNET_SCALARPRODUCT_service_request)) {
2157 GNUNET_free (session);
2158 GNUNET_break_op (0);
2159 return GNUNET_SYSERR;
2161 mask_length = ntohl (msg->mask_length);
2162 pk_length = ntohl (msg->pk_length);
2163 used_elements = ntohl (msg->total_element_count);
2164 contained_elements = ntohl (msg->contained_element_count);
2165 element_count = ntohl (msg->element_count);
2166 msg_length = sizeof (struct GNUNET_SCALARPRODUCT_service_request)
2167 +mask_length + pk_length + contained_elements * PAILLIER_ELEMENT_LENGTH;
2169 //sanity check: is the message as long as the message_count fields suggests?
2170 if ( (ntohs (msg->header.size) != msg_length) ||
2171 (element_count < used_elements) ||
2172 (used_elements < contained_elements) ||
2173 (0 == used_elements) ||
2174 (mask_length != (element_count / 8 + (element_count % 8 ? 1 : 0))) )
2176 GNUNET_free (session);
2177 GNUNET_break_op (0);
2178 return GNUNET_SYSERR;
2180 if (find_matching_session (from_service_tail,
2186 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
2187 _ ("Got message with duplicate session key (`%s'), ignoring service request.\n"),
2188 (const char *) &(msg->key));
2189 GNUNET_free (session);
2190 return GNUNET_SYSERR;
2193 session->total = element_count;
2194 session->used = used_elements;
2195 session->transferred = contained_elements;
2196 session->channel = channel;
2199 memcpy (&session->key, &msg->key, sizeof (struct GNUNET_HashCode));
2200 current = (unsigned char *) &msg[1];
2201 //preserve the mask, we will need that later on
2202 session->mask = GNUNET_malloc (mask_length);
2203 memcpy (session->mask, current, mask_length);
2205 current += mask_length;
2207 //convert the publickey to sexp
2208 if (0 != (rc = gcry_sexp_new (&session->remote_pubkey, current, pk_length, 1))) {
2209 LOG_GCRY (GNUNET_ERROR_TYPE_DEBUG, "gcry_sexp_new", rc);
2210 GNUNET_free (session->mask);
2211 GNUNET_free (session);
2212 return GNUNET_SYSERR;
2214 current += pk_length;
2215 //check if service queue contains a matching request
2216 needed_state = CLIENT_RESPONSE_RECEIVED;
2217 session->response = find_matching_session (from_client_tail,
2220 &needed_state, NULL);
2222 session->a = GNUNET_malloc (sizeof (gcry_mpi_t) * used_elements);
2223 session->state = WAITING_FOR_MULTIPART_TRANSMISSION;
2224 GNUNET_CONTAINER_DLL_insert (from_service_head, from_service_tail, session);
2225 if (contained_elements != 0) {
2226 // Convert each vector element to MPI_value
2227 for (i = 0; i < contained_elements; i++) {
2229 if (0 != (rc = gcry_mpi_scan (&session->a[i],
2231 ¤t[i * PAILLIER_ELEMENT_LENGTH],
2232 PAILLIER_ELEMENT_LENGTH,
2234 LOG_GCRY (GNUNET_ERROR_TYPE_DEBUG, "gcry_mpi_scan", rc);
2238 if (contained_elements == used_elements) {
2239 // single part finished
2240 session->state = SERVICE_REQUEST_RECEIVED;
2241 if (session->response) {
2242 GNUNET_log (GNUNET_ERROR_TYPE_INFO, _ ("Got session with key %s and a matching element set, processing.\n"), GNUNET_h2s (&session->key));
2243 if (GNUNET_OK != compute_service_response (session, session->response)) {
2244 //something went wrong, remove it again...
2249 GNUNET_log (GNUNET_ERROR_TYPE_INFO, _ ("Got session with key %s without a matching element set, queueing.\n"), GNUNET_h2s (&session->key));
2252 // multipart message
2257 GNUNET_break_op (0);
2258 if ((NULL != session->next) || (NULL != session->prev) || (from_service_head == session))
2259 GNUNET_CONTAINER_DLL_remove (from_service_head, from_service_tail, session);
2260 // and notify our client-session that we could not complete the session
2261 if (session->response)
2262 // we just found the responder session in this queue
2263 session->response->client_notification_task =
2264 GNUNET_SCHEDULER_add_now (&prepare_client_end_notification,
2266 free_session_variables (session);
2267 return GNUNET_SYSERR;
2272 * Handle a multipart chunk of a response we got from another service we wanted to calculate a scalarproduct with.
2274 * @param cls closure (set from #GNUNET_MESH_connect)
2275 * @param channel connection to the other end
2276 * @param channel_ctx place to store local state associated with the channel
2277 * @param message the actual message
2278 * @return #GNUNET_OK to keep the connection open,
2279 * #GNUNET_SYSERR to close it (signal serious error)
2282 handle_service_response_multipart (void *cls,
2283 struct GNUNET_MESH_Channel * channel,
2285 const struct GNUNET_MessageHeader * message)
2287 struct ServiceSession * session;
2288 const struct GNUNET_SCALARPRODUCT_multipart_message * msg = (const struct GNUNET_SCALARPRODUCT_multipart_message *) message;
2289 unsigned char * current;
2292 uint32_t contained = 0;
2294 size_t required_size;
2297 GNUNET_assert (NULL != message);
2298 // are we in the correct state?
2299 session = (struct ServiceSession *) * channel_ctx;
2300 if ((ALICE != session->role) || (WAITING_FOR_MULTIPART_TRANSMISSION != session->state)) {
2303 msg_size = ntohs (msg->header.size);
2304 required_size = sizeof (struct GNUNET_SCALARPRODUCT_multipart_message) + 2 * PAILLIER_ELEMENT_LENGTH;
2305 // shorter than minimum?
2306 if (required_size > msg_size) {
2309 contained = ntohl (msg->multipart_element_count);
2310 required_size = sizeof (struct GNUNET_SCALARPRODUCT_multipart_message)
2311 + 2 * contained * PAILLIER_ELEMENT_LENGTH;
2312 //sanity check: is the message as long as the message_count fields suggests?
2313 if ((required_size != msg_size) || (session->used < session->transferred + contained)) {
2316 current = (unsigned char *) &msg[1];
2317 // Convert each k[][perm] to its MPI_value
2318 for (i = 0; i < contained; i++) {
2319 if (0 != (rc = gcry_mpi_scan (&session->r[i], GCRYMPI_FMT_USG, current,
2320 PAILLIER_ELEMENT_LENGTH, &read))) {
2321 LOG_GCRY (GNUNET_ERROR_TYPE_DEBUG, "gcry_mpi_scan", rc);
2324 current += PAILLIER_ELEMENT_LENGTH;
2325 if (0 != (rc = gcry_mpi_scan (&session->r_prime[i], GCRYMPI_FMT_USG, current,
2326 PAILLIER_ELEMENT_LENGTH, &read))) {
2327 LOG_GCRY (GNUNET_ERROR_TYPE_DEBUG, "gcry_mpi_scan", rc);
2330 current += PAILLIER_ELEMENT_LENGTH;
2332 session->transferred += contained;
2333 if (session->transferred != session->used)
2335 session->state = SERVICE_RESPONSE_RECEIVED;
2336 session->product = compute_scalar_product (session); //never NULL
2339 GNUNET_break_op (NULL != session->product);
2341 // send message with product to client
2342 if (ALICE == session->role){
2343 session->state = FINALIZED;
2344 session->channel = NULL;
2345 session->client_notification_task =
2346 GNUNET_SCHEDULER_add_now (&prepare_client_response,
2349 // the channel has done its job, terminate our connection and the channel
2350 // the peer will be notified that the channel was destroyed via channel_destruction_handler
2351 // just close the connection, as recommended by Christian
2352 return GNUNET_SYSERR;
2357 * Handle a response we got from another service we wanted to calculate a scalarproduct with.
2359 * @param cls closure (set from #GNUNET_MESH_connect)
2360 * @param channel connection to the other end
2361 * @param channel_ctx place to store local state associated with the channel
2362 * @param message the actual message
2363 * @return #GNUNET_OK to keep the connection open,
2364 * #GNUNET_SYSERR to close it (we are done)
2367 handle_service_response (void *cls,
2368 struct GNUNET_MESH_Channel * channel,
2370 const struct GNUNET_MessageHeader * message)
2372 struct ServiceSession * session;
2373 const struct GNUNET_SCALARPRODUCT_service_response * msg = (const struct GNUNET_SCALARPRODUCT_service_response *) message;
2374 unsigned char * current;
2377 uint32_t contained = 0;
2379 size_t required_size;
2382 GNUNET_assert (NULL != message);
2383 session = (struct ServiceSession *) * channel_ctx;
2384 // are we in the correct state?
2385 if (WAITING_FOR_SERVICE_RESPONSE != session->state) {
2388 //we need at least a full message without elements attached
2389 msg_size = ntohs (msg->header.size);
2390 required_size = sizeof (struct GNUNET_SCALARPRODUCT_service_response) + 2 * PAILLIER_ELEMENT_LENGTH;
2392 if (required_size > msg_size) {
2395 contained = ntohl (msg->contained_element_count);
2396 required_size = sizeof (struct GNUNET_SCALARPRODUCT_service_response)
2397 + 2 * contained * PAILLIER_ELEMENT_LENGTH
2398 + 2 * PAILLIER_ELEMENT_LENGTH;
2399 //sanity check: is the message as long as the message_count fields suggests?
2400 if ((msg_size != required_size) || (session->used < contained)) {
2403 session->state = WAITING_FOR_MULTIPART_TRANSMISSION;
2404 session->transferred = contained;
2406 current = (unsigned char *) &msg[1];
2407 if (0 != (rc = gcry_mpi_scan (&session->s, GCRYMPI_FMT_USG, current,
2408 PAILLIER_ELEMENT_LENGTH, &read))) {
2409 LOG_GCRY (GNUNET_ERROR_TYPE_DEBUG, "gcry_mpi_scan", rc);
2412 current += PAILLIER_ELEMENT_LENGTH;
2414 if (0 != (rc = gcry_mpi_scan (&session->s_prime, GCRYMPI_FMT_USG, current,
2415 PAILLIER_ELEMENT_LENGTH, &read))) {
2416 LOG_GCRY (GNUNET_ERROR_TYPE_DEBUG, "gcry_mpi_scan", rc);
2419 current += PAILLIER_ELEMENT_LENGTH;
2420 session->r = GNUNET_malloc (sizeof (gcry_mpi_t) * session->used);
2421 session->r_prime = GNUNET_malloc (sizeof (gcry_mpi_t) * session->used);
2422 // Convert each k[][perm] to its MPI_value
2423 for (i = 0; i < contained; i++) {
2424 if (0 != (rc = gcry_mpi_scan (&session->r[i], GCRYMPI_FMT_USG, current,
2425 PAILLIER_ELEMENT_LENGTH, &read))) {
2426 LOG_GCRY (GNUNET_ERROR_TYPE_DEBUG, "gcry_mpi_scan", rc);
2429 current += PAILLIER_ELEMENT_LENGTH;
2430 if (0 != (rc = gcry_mpi_scan (&session->r_prime[i], GCRYMPI_FMT_USG, current,
2431 PAILLIER_ELEMENT_LENGTH, &read))) {
2432 LOG_GCRY (GNUNET_ERROR_TYPE_DEBUG, "gcry_mpi_scan", rc);
2435 current += PAILLIER_ELEMENT_LENGTH;
2437 if (session->transferred != session->used)
2438 return GNUNET_OK; //wait for the other multipart chunks
2440 session->state = SERVICE_RESPONSE_RECEIVED;
2441 session->product = compute_scalar_product (session); //never NULL
2444 GNUNET_break_op (NULL != session->product);
2445 // send message with product to client
2446 if (ALICE == session->role){
2447 session->state = FINALIZED;
2448 session->channel = NULL;
2449 session->client_notification_task =
2450 GNUNET_SCHEDULER_add_now (&prepare_client_response,
2453 // the channel has done its job, terminate our connection and the channel
2454 // the peer will be notified that the channel was destroyed via channel_destruction_handler
2455 // just close the connection, as recommended by Christian
2456 return GNUNET_SYSERR;
2461 * Task run during shutdown.
2467 shutdown_task (void *cls,
2468 const struct GNUNET_SCHEDULER_TaskContext *tc)
2470 struct ServiceSession * session;
2471 GNUNET_log (GNUNET_ERROR_TYPE_INFO, _ ("Shutting down, initiating cleanup.\n"));
2473 do_shutdown = GNUNET_YES;
2475 // terminate all owned open channels.
2476 for (session = from_client_head; NULL != session; session = session->next) {
2477 if ((FINALIZED != session->state) && (NULL != session->channel)) {
2478 GNUNET_MESH_channel_destroy (session->channel);
2479 session->channel = NULL;
2481 if (GNUNET_SCHEDULER_NO_TASK != session->client_notification_task) {
2482 GNUNET_SCHEDULER_cancel (session->client_notification_task);
2483 session->client_notification_task = GNUNET_SCHEDULER_NO_TASK;
2485 if (GNUNET_SCHEDULER_NO_TASK != session->service_request_task) {
2486 GNUNET_SCHEDULER_cancel (session->service_request_task);
2487 session->service_request_task = GNUNET_SCHEDULER_NO_TASK;
2489 if (NULL != session->client) {
2490 GNUNET_SERVER_client_disconnect (session->client);
2491 session->client = NULL;
2494 for (session = from_service_head; NULL != session; session = session->next)
2495 if (NULL != session->channel) {
2496 GNUNET_MESH_channel_destroy (session->channel);
2497 session->channel = NULL;
2501 GNUNET_MESH_disconnect (my_mesh);
2508 * Initialization of the program and message handlers
2510 * @param cls closure
2511 * @param server the initialized server
2512 * @param c configuration to use
2516 struct GNUNET_SERVER_Handle *server,
2517 const struct GNUNET_CONFIGURATION_Handle *c)
2519 static const struct GNUNET_SERVER_MessageHandler server_handlers[] = {
2520 {&handle_client_request, NULL, GNUNET_MESSAGE_TYPE_SCALARPRODUCT_CLIENT_TO_ALICE, 0},
2521 {&handle_client_request, NULL, GNUNET_MESSAGE_TYPE_SCALARPRODUCT_CLIENT_TO_BOB, 0},
2524 static const struct GNUNET_MESH_MessageHandler mesh_handlers[] = {
2525 { &handle_service_request, GNUNET_MESSAGE_TYPE_SCALARPRODUCT_ALICE_TO_BOB, 0},
2526 { &handle_service_request_multipart, GNUNET_MESSAGE_TYPE_SCALARPRODUCT_ALICE_TO_BOB_MULTIPART, 0},
2527 { &handle_service_response, GNUNET_MESSAGE_TYPE_SCALARPRODUCT_BOB_TO_ALICE, 0},
2528 { &handle_service_response_multipart, GNUNET_MESSAGE_TYPE_SCALARPRODUCT_BOB_TO_ALICE_MULTIPART, 0},
2531 static const uint32_t ports[] = {
2532 GNUNET_APPLICATION_TYPE_SCALARPRODUCT,
2535 //generate private/public key set
2536 GNUNET_log (GNUNET_ERROR_TYPE_INFO, _ ("Generating Paillier-Keyset.\n"));
2538 // register server callbacks and disconnect handler
2539 GNUNET_SERVER_add_handlers (server, server_handlers);
2540 GNUNET_SERVER_disconnect_notify (server,
2541 &handle_client_disconnect,
2543 GNUNET_break (GNUNET_OK ==
2544 GNUNET_CRYPTO_get_peer_identity (c,
2546 my_mesh = GNUNET_MESH_connect (c, NULL,
2547 &channel_incoming_handler,
2548 &channel_destruction_handler,
2549 mesh_handlers, ports);
2551 GNUNET_log (GNUNET_ERROR_TYPE_ERROR, _ ("Connect to MESH failed\n"));
2552 GNUNET_SCHEDULER_shutdown ();
2555 GNUNET_log (GNUNET_ERROR_TYPE_INFO, _ ("Mesh initialized\n"));
2556 GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_FOREVER_REL,
2563 * The main function for the scalarproduct service.
2565 * @param argc number of arguments from the command line
2566 * @param argv command line arguments
2567 * @return 0 ok, 1 on error
2570 main (int argc, char *const *argv)
2572 return (GNUNET_OK ==
2573 GNUNET_SERVICE_run (argc, argv,
2575 GNUNET_SERVICE_OPTION_NONE,
2576 &run, NULL)) ? 0 : 1;
2579 /* end of gnunet-service-scalarproduct.c */