2 This file is part of GNUnet.
3 (C) 2013 Christian Grothoff (and other contributing authors)
5 GNUnet is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published
7 by the Free Software Foundation; either version 3, or (at your
8 option) any later version.
10 GNUnet is distributed in the hope that it will be useful, but
11 WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 General Public License for more details.
15 You should have received a copy of the GNU General Public License
16 along with GNUnet; see the file COPYING. If not, write to the
17 Free Software Foundation, Inc., 59 Temple Place - Suite 330,
18 Boston, MA 02111-1307, USA.
22 * @file scalarproduct/gnunet-service-scalarproduct.c
23 * @brief scalarproduct service implementation
24 * @author Christian M. Fuchs
28 #include "gnunet_util_lib.h"
29 #include "gnunet_core_service.h"
30 #include "gnunet_mesh_service.h"
31 #include "gnunet_applications.h"
32 #include "gnunet_protocols.h"
33 #include "gnunet_scalarproduct_service.h"
34 #include "scalarproduct.h"
36 #define LOG(kind,...) GNUNET_log_from (kind, "scalarproduct", __VA_ARGS__)
38 ///////////////////////////////////////////////////////////////////////////////
39 // Service Structure Definitions
40 ///////////////////////////////////////////////////////////////////////////////
44 * state a session can be in
48 CLIENT_REQUEST_RECEIVED,
49 WAITING_FOR_BOBS_CONNECT,
50 CLIENT_RESPONSE_RECEIVED,
51 WAITING_FOR_SERVICE_REQUEST,
52 WAITING_FOR_MULTIPART_TRANSMISSION,
53 WAITING_FOR_SERVICE_RESPONSE,
54 SERVICE_REQUEST_RECEIVED,
55 SERVICE_RESPONSE_RECEIVED,
61 * role a peer in a session can assume
71 * A scalarproduct session which tracks:
73 * a request form the client to our final response.
75 * a request from a service to us(service).
80 * the role this peer has
85 * session information is kept in a DLL
87 struct ServiceSession *next;
90 * session information is kept in a DLL
92 struct ServiceSession *prev;
95 * (hopefully) unique transaction ID
97 struct GNUNET_HashCode key;
100 * state of the session
102 enum SessionState state;
105 * Alice or Bob's peerID
107 struct GNUNET_PeerIdentity peer;
110 * the client this request is related to
112 struct GNUNET_SERVER_Client * client;
115 * The message to send
117 struct GNUNET_MessageHeader * msg;
120 * how many elements we were supplied with from the client
125 * how many elements actually are used after applying the mask
130 * already transferred elements (sent/received) for multipart messages, less or equal than used_element_count for
132 uint32_t transferred;
135 * index of the last transferred element for multipart messages
137 uint32_t last_processed;
140 * how many bytes the mask is long.
141 * just for convenience so we don't have to re-re-re calculate it each time
143 uint32_t mask_length;
146 * all the vector elements we received
151 * mask of which elements to check
153 unsigned char * mask;
156 * Public key of the remote service, only used by bob
158 gcry_sexp_t remote_pubkey;
161 * E(ai)(Bob) or ai(Alice) after applying the mask
166 * Bob's permutation p of R
171 * Bob's permutation q of R
173 gcry_mpi_t * r_prime;
186 * Bobs matching response session from the client
188 struct ServiceSession * response;
191 * The computed scalar
196 * My transmit handle for the current message to a alice/bob
198 struct GNUNET_MESH_TransmitHandle * service_transmit_handle;
201 * My transmit handle for the current message to the client
203 struct GNUNET_SERVER_TransmitHandle * client_transmit_handle;
206 * channel-handle associated with our mesh handle
208 struct GNUNET_MESH_Channel * channel;
211 * Handle to a task that sends a msg to the our client
213 GNUNET_SCHEDULER_TaskIdentifier client_notification_task;
216 * Handle to a task that sends a msg to the our peer
218 GNUNET_SCHEDULER_TaskIdentifier service_request_task;
221 ///////////////////////////////////////////////////////////////////////////////
222 // Forward Delcarations
223 ///////////////////////////////////////////////////////////////////////////////
226 * Send a multi part chunk of a service request from alice to bob.
227 * This element only contains a part of the elements-vector (session->a[]),
228 * mask and public key set have to be contained within the first message
230 * This allows a ~32kbit key length while using 32000 elements or 62000 elements per request.
232 * @param cls the associated service session
235 prepare_service_request_multipart (void *cls);
238 * Send a multi part chunk of a service response from bob to alice.
239 * This element only contains the two permutations of R, R'.
241 * @param cls the associated service session
244 prepare_service_response_multipart (void *cls);
247 ///////////////////////////////////////////////////////////////////////////////
249 ///////////////////////////////////////////////////////////////////////////////
253 * Handle to the core service (NULL until we've connected to it).
255 static struct GNUNET_MESH_Handle *my_mesh;
258 * The identity of this host.
260 static struct GNUNET_PeerIdentity me;
263 * Service's own public key represented as string
265 static unsigned char * my_pubkey_external;
268 * Service's own public key represented as string
270 static uint32_t my_pubkey_external_length = 0;
275 static gcry_mpi_t my_n;
278 * Service's own n^2 (kept for performance)
280 static gcry_mpi_t my_nsquare;
283 * Service's own public exponent
285 static gcry_mpi_t my_g;
288 * Service's own private multiplier
290 static gcry_mpi_t my_mu;
293 * Service's own private exponent
295 static gcry_mpi_t my_lambda;
298 * Service's offset for values that could possibly be negative but are plaintext for encryption.
300 static gcry_mpi_t my_offset;
303 * Head of our double linked list for client-requests sent to us.
304 * for all of these elements we calculate a scalar product with a remote peer
305 * split between service->service and client->service for simplicity
307 static struct ServiceSession * from_client_head;
309 * Tail of our double linked list for client-requests sent to us.
310 * for all of these elements we calculate a scalar product with a remote peer
311 * split between service->service and client->service for simplicity
313 static struct ServiceSession * from_client_tail;
316 * Head of our double linked list for service-requests sent to us.
317 * for all of these elements we help the requesting service in calculating a scalar product
318 * split between service->service and client->service for simplicity
320 static struct ServiceSession * from_service_head;
323 * Tail of our double linked list for service-requests sent to us.
324 * for all of these elements we help the requesting service in calculating a scalar product
325 * split between service->service and client->service for simplicity
327 static struct ServiceSession * from_service_tail;
330 * Certain events (callbacks for server & mesh operations) must not be queued after shutdown.
332 static int do_shutdown;
334 ///////////////////////////////////////////////////////////////////////////////
336 ///////////////////////////////////////////////////////////////////////////////
340 * Generates an Paillier private/public keyset and extracts the values using libgrcypt only
345 gcry_sexp_t gen_params;
347 gcry_sexp_t tmp_sexp;
356 // we can still use the RSA keygen for generating p,q,n, but using e is pointless.
357 GNUNET_assert (0 == gcry_sexp_build (&gen_params, &erroff,
358 "(genkey(rsa(nbits %d)(rsa-use-e 3:257)))",
361 GNUNET_assert (0 == gcry_pk_genkey (&key, gen_params));
362 gcry_sexp_release (gen_params);
364 // get n and d of our publickey as MPI
365 tmp_sexp = gcry_sexp_find_token (key, "n", 0);
366 GNUNET_assert (tmp_sexp);
367 my_n = gcry_sexp_nth_mpi (tmp_sexp, 1, GCRYMPI_FMT_USG);
368 gcry_sexp_release (tmp_sexp);
369 tmp_sexp = gcry_sexp_find_token (key, "p", 0);
370 GNUNET_assert (tmp_sexp);
371 p = gcry_sexp_nth_mpi (tmp_sexp, 1, GCRYMPI_FMT_USG);
372 gcry_sexp_release (tmp_sexp);
373 tmp_sexp = gcry_sexp_find_token (key, "q", 0);
374 GNUNET_assert (tmp_sexp);
375 q = gcry_sexp_nth_mpi (tmp_sexp, 1, GCRYMPI_FMT_USG);
376 gcry_sexp_release (key);
378 tmp1 = gcry_mpi_new (0);
379 tmp2 = gcry_mpi_new (0);
380 gcd = gcry_mpi_new (0);
381 my_g = gcry_mpi_new (0);
382 my_mu = gcry_mpi_new (0);
383 my_nsquare = gcry_mpi_new (0);
384 my_lambda = gcry_mpi_new (0);
387 // lambda = frac{(p-1)*(q-1)}{gcd(p-1,q-1)}
388 gcry_mpi_sub_ui (tmp1, p, 1);
389 gcry_mpi_sub_ui (tmp2, q, 1);
390 gcry_mpi_gcd (gcd, tmp1, tmp2);
391 gcry_mpi_set (my_lambda, tmp1);
392 gcry_mpi_mul (my_lambda, my_lambda, tmp2);
393 gcry_mpi_div (my_lambda, NULL, my_lambda, gcd, 0);
396 gcry_mpi_mul (my_nsquare, my_n, my_n);
400 gcry_mpi_randomize (my_g, KEYBITS * 2, GCRY_WEAK_RANDOM);
401 // g must be smaller than n^2
402 if (0 >= gcry_mpi_cmp (my_g, my_nsquare))
405 // g must have gcd == 1 with n^2
406 gcry_mpi_gcd (gcd, my_g, my_nsquare);
408 while (gcry_mpi_cmp_ui (gcd, 1));
410 // is this a valid g?
411 // if so, gcd(((g^lambda mod n^2)-1 )/n, n) = 1
412 gcry_mpi_powm (tmp1, my_g, my_lambda, my_nsquare);
413 gcry_mpi_sub_ui (tmp1, tmp1, 1);
414 gcry_mpi_div (tmp1, NULL, tmp1, my_n, 0);
415 gcry_mpi_gcd (gcd, tmp1, my_n);
417 while (gcry_mpi_cmp_ui (gcd, 1));
419 // calculate our mu based on g and n.
420 // mu = (((g^lambda mod n^2)-1 )/n)^-1 mod n
421 gcry_mpi_invm (my_mu, tmp1, my_n);
423 GNUNET_assert (0 == gcry_sexp_build (&key, &erroff,
424 "(public-key (paillier (n %M)(g %M)))",
427 // get the length of this sexpression
428 my_pubkey_external_length = gcry_sexp_sprint (key,
433 GNUNET_assert (my_pubkey_external_length > 0);
434 my_pubkey_external = GNUNET_malloc (my_pubkey_external_length);
436 // convert the sexpression to canonical format
437 gcry_sexp_sprint (key,
440 my_pubkey_external_length);
442 gcry_sexp_release (key);
444 // offset has to be sufficiently small to allow computation of:
445 // m1+m2 mod n == (S + a) + (S + b) mod n,
446 // if we have more complex operations, this factor needs to be lowered
447 my_offset = gcry_mpi_new (KEYBITS / 3);
448 gcry_mpi_set_bit (my_offset, KEYBITS / 3);
450 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, _ ("Generated key set with key length %d bits.\n"), KEYBITS);
455 * If target != size, move target bytes to the
456 * end of the size-sized buffer and zero out the
457 * first target-size bytes.
459 * @param buf original buffer
460 * @param size number of bytes in the buffer
461 * @param target target size of the buffer
464 adjust (unsigned char *buf, size_t size, size_t target)
467 memmove (&buf[target - size], buf, size);
468 memset (buf, 0, target - size);
474 * decrypts an element using the paillier crypto system
476 * @param m plaintext (output)
477 * @param c the ciphertext
478 * @param mu the modifier to correct encryption
479 * @param lambda the private exponent
480 * @param n the outer module for decryption
481 * @param n_square the inner module for decryption
484 decrypt_element (gcry_mpi_t m, gcry_mpi_t c, gcry_mpi_t mu, gcry_mpi_t lambda, gcry_mpi_t n, gcry_mpi_t n_square)
486 gcry_mpi_powm (m, c, lambda, n_square);
487 gcry_mpi_sub_ui (m, m, 1);
488 gcry_mpi_div (m, NULL, m, n, 0);
489 gcry_mpi_mulm (m, m, mu, n);
494 * computes the square sum over a vector of a given length.
496 * @param vector the vector to encrypt
497 * @param length the length of the vector
498 * @return an MPI value containing the calculated sum, never NULL
501 compute_square_sum (gcry_mpi_t * vector, uint32_t length)
507 GNUNET_assert (sum = gcry_mpi_new (0));
508 GNUNET_assert (elem = gcry_mpi_new (0));
510 // calculare E(sum (ai ^ 2), publickey)
511 for (i = 0; i < length; i++) {
512 gcry_mpi_mul (elem, vector[i], vector[i]);
513 gcry_mpi_add (sum, sum, elem);
515 gcry_mpi_release (elem);
522 * Primitive callback for copying over a message, as they
523 * usually are too complex to be handled in the callback itself.
524 * clears a session-callback, if a session was handed over and the transmit handle was stored
526 * @param cls the message object
527 * @param size the size of the buffer we got
528 * @param buf the buffer to copy the message to
529 * @return 0 if we couldn't copy, else the size copied over
532 do_send_message (void *cls, size_t size, void *buf)
534 struct ServiceSession * session = cls;
539 if (ntohs (session->msg->size) != size) {
544 type = ntohs (session->msg->type);
545 memcpy (buf, session->msg, size);
546 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
547 "Sent a message of type %hu.\n",
549 GNUNET_free (session->msg);
554 case GNUNET_MESSAGE_TYPE_SCALARPRODUCT_SERVICE_TO_CLIENT:
555 session->state = FINALIZED;
556 session->client_transmit_handle = NULL;
559 case GNUNET_MESSAGE_TYPE_SCALARPRODUCT_ALICE_TO_BOB:
560 case GNUNET_MESSAGE_TYPE_SCALARPRODUCT_ALICE_TO_BOB_MULTIPART:
561 session->service_transmit_handle = NULL;
562 if (session->state == WAITING_FOR_MULTIPART_TRANSMISSION)
563 prepare_service_request_multipart (session);
566 case GNUNET_MESSAGE_TYPE_SCALARPRODUCT_BOB_TO_ALICE:
567 case GNUNET_MESSAGE_TYPE_SCALARPRODUCT_BOB_TO_ALICE_MULTIPART:
568 session->service_transmit_handle = NULL;
569 if (session->state == WAITING_FOR_MULTIPART_TRANSMISSION)
570 prepare_service_response_multipart (session);
582 * initializes a new vector with fresh MPI values (=0) of a given length
584 * @param length of the vector to create
585 * @return the initialized vector, never NULL
588 initialize_mpi_vector (uint32_t length)
591 gcry_mpi_t * output = GNUNET_malloc (sizeof (gcry_mpi_t) * length);
593 for (i = 0; i < length; i++)
594 GNUNET_assert (NULL != (output[i] = gcry_mpi_new (0)));
600 * permutes an MPI vector according to the given permutation vector
602 * @param vector the vector to permuted
603 * @param perm the permutation to use
604 * @param length the length of the vectors
605 * @return the permuted vector (same as input), never NULL
608 permute_vector (gcry_mpi_t * vector,
612 gcry_mpi_t tmp[length];
615 GNUNET_assert (length > 0);
618 memcpy (tmp, vector, length * sizeof (gcry_mpi_t));
620 // permute vector according to given
621 for (i = 0; i < length; i++)
622 vector[i] = tmp[perm[i]];
629 * Finds a not terminated client/service session in the
630 * given DLL based on session key, element count and state.
632 * @param tail - the tail of the DLL
633 * @param key - the key we want to search for
634 * @param element_count - the total element count of the dataset (session->total)
635 * @param state - a pointer to the state the session should be in, NULL to ignore
636 * @param peerid - a pointer to the peer ID of the associated peer, NULL to ignore
637 * @return a pointer to a matching session, or NULL
639 static struct ServiceSession *
640 find_matching_session (struct ServiceSession * tail,
641 const struct GNUNET_HashCode * key,
642 uint32_t element_count,
643 enum SessionState * state,
644 const struct GNUNET_PeerIdentity * peerid)
646 struct ServiceSession * curr;
648 for (curr = tail; NULL != curr; curr = curr->prev) {
649 // if the key matches, and the element_count is same
650 if ((!memcmp (&curr->key, key, sizeof (struct GNUNET_HashCode)))
651 && (curr->total == element_count)) {
652 // if incoming state is NULL OR is same as state of the queued request
653 if ((NULL == state) || (curr->state == *state)) {
654 // if peerid is NULL OR same as the peer Id in the queued request
656 || (!memcmp (&curr->peer, peerid, sizeof (struct GNUNET_PeerIdentity))))
657 // matches and is not an already terminated session
667 * Safely frees ALL memory areas referenced by a session.
669 * @param session - the session to free elements from
672 free_session_variables (struct ServiceSession * session)
677 for (i = 0; i < session->used; i++)
678 if (session->a[i]) gcry_mpi_release (session->a[i]);
679 GNUNET_free (session->a);
683 GNUNET_free (session->mask);
684 session->mask = NULL;
687 for (i = 0; i < session->used; i++)
688 if (session->r[i]) gcry_mpi_release (session->r[i]);
689 GNUNET_free (session->r);
692 if (session->r_prime) {
693 for (i = 0; i < session->used; i++)
694 if (session->r_prime[i]) gcry_mpi_release (session->r_prime[i]);
695 GNUNET_free (session->r_prime);
696 session->r_prime = NULL;
699 gcry_mpi_release (session->s);
703 if (session->s_prime) {
704 gcry_mpi_release (session->s_prime);
705 session->s_prime = NULL;
708 if (session->product) {
709 gcry_mpi_release (session->product);
710 session->product = NULL;
713 if (session->remote_pubkey) {
714 gcry_sexp_release (session->remote_pubkey);
715 session->remote_pubkey = NULL;
718 if (session->vector) {
719 GNUNET_free_non_null (session->vector);
723 ///////////////////////////////////////////////////////////////////////////////
724 // Event and Message Handlers
725 ///////////////////////////////////////////////////////////////////////////////
729 * A client disconnected.
731 * Remove the associated session(s), release data structures
732 * and cancel pending outgoing transmissions to the client.
733 * if the session has not yet completed, we also cancel Alice's request to Bob.
735 * @param cls closure, NULL
736 * @param client identification of the client
739 handle_client_disconnect (void *cls,
740 struct GNUNET_SERVER_Client *client)
742 struct ServiceSession *session;
745 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
746 _ ("Client (%p) disconnected from us.\n"), client);
750 session = GNUNET_SERVER_client_get_user_context (client, struct ServiceSession);
753 GNUNET_CONTAINER_DLL_remove (from_client_head, from_client_tail, session);
755 if (!(session->role == BOB && session->state == FINALIZED)) {
756 //we MUST terminate any client message underway
757 if (session->service_transmit_handle && session->channel)
758 GNUNET_MESH_notify_transmit_ready_cancel (session->service_transmit_handle);
759 if (session->channel && session->state == WAITING_FOR_SERVICE_RESPONSE)
760 GNUNET_MESH_channel_destroy (session->channel);
762 if (GNUNET_SCHEDULER_NO_TASK != session->client_notification_task) {
763 GNUNET_SCHEDULER_cancel (session->client_notification_task);
764 session->client_notification_task = GNUNET_SCHEDULER_NO_TASK;
766 if (GNUNET_SCHEDULER_NO_TASK != session->service_request_task) {
767 GNUNET_SCHEDULER_cancel (session->service_request_task);
768 session->service_request_task = GNUNET_SCHEDULER_NO_TASK;
770 if (NULL != session->client_transmit_handle) {
771 GNUNET_SERVER_notify_transmit_ready_cancel (session->client_transmit_handle);
772 session->client_transmit_handle = NULL;
774 free_session_variables (session);
775 GNUNET_free (session);
780 * Notify the client that the session has succeeded or failed completely.
781 * This message gets sent to
782 * * alice's client if bob disconnected or to
783 * * bob's client if the operation completed or alice disconnected
785 * @param cls the associated client session
786 * @param tc the task context handed to us by the scheduler, unused
789 prepare_client_end_notification (void * cls,
790 const struct GNUNET_SCHEDULER_TaskContext * tc)
792 struct ServiceSession * session = cls;
793 struct GNUNET_SCALARPRODUCT_client_response * msg;
795 session->client_notification_task = GNUNET_SCHEDULER_NO_TASK;
797 msg = GNUNET_new (struct GNUNET_SCALARPRODUCT_client_response);
798 msg->header.type = htons (GNUNET_MESSAGE_TYPE_SCALARPRODUCT_SERVICE_TO_CLIENT);
799 memcpy (&msg->key, &session->key, sizeof (struct GNUNET_HashCode));
800 memcpy (&msg->peer, &session->peer, sizeof ( struct GNUNET_PeerIdentity));
801 msg->header.size = htons (sizeof (struct GNUNET_SCALARPRODUCT_client_response));
802 // signal error if not signalized, positive result-range field but zero length.
803 msg->product_length = htonl (0);
804 msg->range = (session->state == FINALIZED) ? 0 : -1;
806 session->msg = &msg->header;
808 //transmit this message to our client
809 session->client_transmit_handle =
810 GNUNET_SERVER_notify_transmit_ready (session->client,
811 sizeof (struct GNUNET_SCALARPRODUCT_client_response),
812 GNUNET_TIME_UNIT_FOREVER_REL,
816 // if we could not even queue our request, something is wrong
817 if (NULL == session->client_transmit_handle) {
818 GNUNET_log (GNUNET_ERROR_TYPE_WARNING, _ ("Could not send message to client (%p)!\n"), session->client);
819 // usually gets freed by do_send_message
824 GNUNET_log (GNUNET_ERROR_TYPE_INFO, _ ("Sending session-end notification to client (%p) for session %s\n"), &session->client, GNUNET_h2s (&session->key));
826 free_session_variables (session);
831 * prepare the response we will send to alice or bobs' clients.
832 * in Bobs case the product will be NULL.
834 * @param cls the session associated with our client.
835 * @param tc the task context handed to us by the scheduler, unused
838 prepare_client_response (void *cls,
839 const struct GNUNET_SCHEDULER_TaskContext *tc)
841 struct ServiceSession * session = cls;
842 struct GNUNET_SCALARPRODUCT_client_response * msg;
843 unsigned char * product_exported = NULL;
844 size_t product_length = 0;
845 uint32_t msg_length = 0;
850 session->client_notification_task = GNUNET_SCHEDULER_NO_TASK;
852 if (session->product) {
853 gcry_mpi_t value = gcry_mpi_new (0);
855 sign = gcry_mpi_cmp_ui (session->product, 0);
856 // libgcrypt can not handle a print of a negative number
857 // if (a->sign) return gcry_error (GPG_ERR_INTERNAL); /* Can't handle it yet. */
859 gcry_mpi_sub (value, value, session->product);
863 gcry_mpi_add (value, value, session->product);
868 gcry_mpi_release (session->product);
869 session->product = NULL;
871 // get representation as string
873 && (0 != (rc = gcry_mpi_aprint (GCRYMPI_FMT_STD,
877 LOG_GCRY (GNUNET_ERROR_TYPE_ERROR, "gcry_mpi_scan", rc);
879 range = -1; // signal error with product-length = 0 and range = -1
881 gcry_mpi_release (value);
884 msg_length = sizeof (struct GNUNET_SCALARPRODUCT_client_response) +product_length;
885 msg = GNUNET_malloc (msg_length);
886 msg->key = session->key;
887 msg->peer = session->peer;
888 if (product_exported != NULL)
890 memcpy (&msg[1], product_exported, product_length);
891 GNUNET_free (product_exported);
893 msg->header.type = htons (GNUNET_MESSAGE_TYPE_SCALARPRODUCT_SERVICE_TO_CLIENT);
894 msg->header.size = htons (msg_length);
896 msg->product_length = htonl (product_length);
898 session->msg = (struct GNUNET_MessageHeader *) msg;
899 //transmit this message to our client
900 session->client_transmit_handle =
901 GNUNET_SERVER_notify_transmit_ready (session->client,
903 GNUNET_TIME_UNIT_FOREVER_REL,
906 if (NULL == session->client_transmit_handle) {
907 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
908 _ ("Could not send message to client (%p)!\n"),
910 session->client = NULL;
911 // callback was not called!
916 // gracefully sent message, just terminate session structure
917 GNUNET_log (GNUNET_ERROR_TYPE_INFO,
918 _ ("Sent result to client (%p), this session (%s) has ended!\n"),
920 GNUNET_h2s (&session->key));
921 free_session_variables (session);
926 * Send a multipart chunk of a service response from bob to alice.
927 * This element only contains the two permutations of R, R'.
929 * @param cls the associated service session
932 prepare_service_response_multipart (void *cls)
934 struct ServiceSession * session = cls;
935 unsigned char * current;
936 unsigned char * element_exported;
937 struct GNUNET_SCALARPRODUCT_multipart_message * msg;
941 size_t element_length = 0; // initialized by gcry_mpi_print, but the compiler doesn't know that
943 msg_length = sizeof (struct GNUNET_SCALARPRODUCT_multipart_message);
944 todo_count = session->used - session->transferred;
946 if (todo_count > MULTIPART_ELEMENT_CAPACITY / 2)
947 // send the currently possible maximum chunk, we always transfer both permutations
948 todo_count = MULTIPART_ELEMENT_CAPACITY / 2;
950 msg_length += todo_count * PAILLIER_ELEMENT_LENGTH * 2;
951 msg = GNUNET_malloc (msg_length);
952 msg->header.type = htons (GNUNET_MESSAGE_TYPE_SCALARPRODUCT_ALICE_TO_BOB_MULTIPART);
953 msg->header.size = htons (msg_length);
954 msg->multipart_element_count = htonl (todo_count);
956 element_exported = GNUNET_malloc (PAILLIER_ELEMENT_LENGTH);
957 current = (unsigned char *) &msg[1];
959 for (i = session->transferred; i < session->transferred + todo_count; i++) {
961 memset (element_exported, 0, PAILLIER_ELEMENT_LENGTH);
962 GNUNET_assert (0 == gcry_mpi_print (GCRYMPI_FMT_USG,
963 element_exported, PAILLIER_ELEMENT_LENGTH,
966 adjust (element_exported, element_length, PAILLIER_ELEMENT_LENGTH);
967 memcpy (current, element_exported, PAILLIER_ELEMENT_LENGTH);
968 current += PAILLIER_ELEMENT_LENGTH;
970 memset (element_exported, 0, PAILLIER_ELEMENT_LENGTH);
971 GNUNET_assert (0 == gcry_mpi_print (GCRYMPI_FMT_USG,
972 element_exported, PAILLIER_ELEMENT_LENGTH,
974 session->r_prime[i]));
975 adjust (element_exported, element_length, PAILLIER_ELEMENT_LENGTH);
976 memcpy (current, element_exported, PAILLIER_ELEMENT_LENGTH);
977 current += PAILLIER_ELEMENT_LENGTH;
979 GNUNET_free (element_exported);
980 for (i = session->transferred; i < session->transferred; i++) {
981 gcry_mpi_release (session->r_prime[i]);
982 session->r_prime[i] = NULL;
983 gcry_mpi_release (session->r[i]);
984 session->r[i] = NULL;
986 session->transferred += todo_count;
987 session->msg = (struct GNUNET_MessageHeader *) msg;
988 session->service_transmit_handle =
989 GNUNET_MESH_notify_transmit_ready (session->channel,
991 GNUNET_TIME_UNIT_FOREVER_REL,
995 //disconnect our client
996 if (NULL == session->service_transmit_handle) {
997 GNUNET_log (GNUNET_ERROR_TYPE_ERROR, _ ("Could not send service-response message via mesh!)\n"));
998 session->state = FINALIZED;
1000 session->response->client_notification_task =
1001 GNUNET_SCHEDULER_add_now (&prepare_client_end_notification,
1005 if (session->transferred != session->used)
1007 session->state = WAITING_FOR_MULTIPART_TRANSMISSION;
1010 session->state = FINALIZED;
1011 GNUNET_free(session->r);
1012 GNUNET_free(session->r_prime);
1013 session->r_prime = NULL;
1021 * generates the response message to be sent to alice after computing
1022 * the values (1), (2), S and S'
1023 * (1)[]: $E_A(a_{pi(i)}) times E_A(- r_{pi(i)} - b_{pi(i)}) &= E_A(a_{pi(i)} - r_{pi(i)} - b_{pi(i)})$
1024 * (2)[]: $E_A(a_{pi'(i)}) times E_A(- r_{pi'(i)}) &= E_A(a_{pi'(i)} - r_{pi'(i)})$
1025 * S: $S := E_A(sum (r_i + b_i)^2)$
1026 * S': $S' := E_A(sum r_i^2)$
1028 * @param s S: $S := E_A(sum (r_i + b_i)^2)$
1029 * @param s_prime S': $S' := E_A(sum r_i^2)$
1030 * @param session the associated requesting session with alice
1031 * @return #GNUNET_NO if we could not send our message
1032 * #GNUNET_OK if the operation succeeded
1035 prepare_service_response (gcry_mpi_t s,
1037 struct ServiceSession * session)
1039 struct GNUNET_SCALARPRODUCT_service_response * msg;
1040 uint32_t msg_length = 0;
1041 unsigned char * current = NULL;
1042 unsigned char * element_exported = NULL;
1043 size_t element_length = 0;
1046 msg_length = sizeof (struct GNUNET_SCALARPRODUCT_service_response)
1047 + 2 * PAILLIER_ELEMENT_LENGTH; // s, stick
1049 if (GNUNET_SERVER_MAX_MESSAGE_SIZE > msg_length + 2 * session->used * PAILLIER_ELEMENT_LENGTH) { //kp, kq
1050 msg_length += +2 * session->used * PAILLIER_ELEMENT_LENGTH;
1051 session->transferred = session->used;
1054 session->transferred = (GNUNET_SERVER_MAX_MESSAGE_SIZE - 1 - msg_length) / (PAILLIER_ELEMENT_LENGTH * 2);
1057 msg = GNUNET_malloc (msg_length);
1059 msg->header.type = htons (GNUNET_MESSAGE_TYPE_SCALARPRODUCT_BOB_TO_ALICE);
1060 msg->header.size = htons (msg_length);
1061 msg->total_element_count = htonl (session->total);
1062 msg->used_element_count = htonl (session->used);
1063 msg->contained_element_count = htonl (session->transferred);
1064 memcpy (&msg->key, &session->key, sizeof (struct GNUNET_HashCode));
1065 current = (unsigned char *) &msg[1];
1067 element_exported = GNUNET_malloc (PAILLIER_ELEMENT_LENGTH);
1068 // 4 times the same logics with slight variations.
1069 // doesn't really justify having 2 functions for that
1070 // so i put it into blocks to enhance readability
1072 memset (element_exported, 0, PAILLIER_ELEMENT_LENGTH);
1073 GNUNET_assert (0 == gcry_mpi_print (GCRYMPI_FMT_USG,
1074 element_exported, PAILLIER_ELEMENT_LENGTH,
1077 adjust (element_exported, element_length, PAILLIER_ELEMENT_LENGTH);
1078 memcpy (current, element_exported, PAILLIER_ELEMENT_LENGTH);
1079 current += PAILLIER_ELEMENT_LENGTH;
1082 memset (element_exported, 0, PAILLIER_ELEMENT_LENGTH);
1083 GNUNET_assert (0 == gcry_mpi_print (GCRYMPI_FMT_USG,
1084 element_exported, PAILLIER_ELEMENT_LENGTH,
1087 adjust (element_exported, element_length, PAILLIER_ELEMENT_LENGTH);
1088 memcpy (current, element_exported, PAILLIER_ELEMENT_LENGTH);
1089 current += PAILLIER_ELEMENT_LENGTH;
1092 for (i = 0; i < session->transferred; i++) {
1094 memset (element_exported, 0, PAILLIER_ELEMENT_LENGTH);
1095 GNUNET_assert (0 == gcry_mpi_print (GCRYMPI_FMT_USG,
1096 element_exported, PAILLIER_ELEMENT_LENGTH,
1099 adjust (element_exported, element_length, PAILLIER_ELEMENT_LENGTH);
1100 memcpy (current, element_exported, PAILLIER_ELEMENT_LENGTH);
1101 current += PAILLIER_ELEMENT_LENGTH;
1103 memset (element_exported, 0, PAILLIER_ELEMENT_LENGTH);
1104 GNUNET_assert (0 == gcry_mpi_print (GCRYMPI_FMT_USG,
1105 element_exported, PAILLIER_ELEMENT_LENGTH,
1107 session->r_prime[i]));
1108 adjust (element_exported, element_length, PAILLIER_ELEMENT_LENGTH);
1109 memcpy (current, element_exported, PAILLIER_ELEMENT_LENGTH);
1110 current += PAILLIER_ELEMENT_LENGTH;
1113 GNUNET_free (element_exported);
1114 for (i = 0; i < session->transferred; i++) {
1115 gcry_mpi_release (session->r_prime[i]);
1116 session->r_prime[i] = NULL;
1117 gcry_mpi_release (session->r[i]);
1118 session->r[i] = NULL;
1120 gcry_mpi_release (s);
1122 gcry_mpi_release (s_prime);
1123 session->s_prime = NULL;
1125 session->msg = (struct GNUNET_MessageHeader *) msg;
1126 session->service_transmit_handle =
1127 GNUNET_MESH_notify_transmit_ready (session->channel,
1129 GNUNET_TIME_UNIT_FOREVER_REL,
1133 //disconnect our client
1134 if (NULL == session->service_transmit_handle) {
1135 GNUNET_log (GNUNET_ERROR_TYPE_ERROR, _ ("Could not send service-response message via mesh!)\n"));
1136 session->state = FINALIZED;
1138 session->response->client_notification_task =
1139 GNUNET_SCHEDULER_add_now (&prepare_client_end_notification,
1143 if (session->transferred != session->used)
1145 session->state = WAITING_FOR_MULTIPART_TRANSMISSION;
1148 session->state = FINALIZED;
1149 GNUNET_free(session->r);
1150 GNUNET_free(session->r_prime);
1151 session->r_prime = NULL;
1161 * compute the values
1162 * (1)[]: $E_A(a_{pi(i)}) otimes E_A(- r_{pi(i)} - b_{pi(i)}) &= E_A(a_{pi(i)} - r_{pi(i)} - b_{pi(i)})$
1163 * (2)[]: $E_A(a_{pi'(i)}) otimes E_A(- r_{pi'(i)}) &= E_A(a_{pi'(i)} - r_{pi'(i)})$
1164 * S: $S := E_A(sum (r_i + b_i)^2)$
1165 * S': $S' := E_A(sum r_i^2)$
1167 * @param request the requesting session + bob's requesting peer
1168 * @param response the responding session + bob's client handle
1169 * @return GNUNET_SYSERR if the computation failed
1170 * GNUNET_OK if everything went well.
1173 compute_service_response (struct ServiceSession * request,
1174 struct ServiceSession * response)
1178 int ret = GNUNET_SYSERR;
1182 gcry_mpi_t * rand = NULL;
1183 gcry_mpi_t * r = NULL;
1184 struct GNUNET_CRYPTO_PaillierCiphertext * R;
1185 gcry_mpi_t * r_prime = NULL;
1186 struct GNUNET_CRYPTO_PaillierCiphertext * R_prime;
1189 gcry_mpi_t * a_pi_prime;
1191 gcry_mpi_t * rand_pi;
1192 gcry_mpi_t * rand_pi_prime;
1193 gcry_mpi_t s = NULL;
1194 struct GNUNET_CRYPTO_PaillierCiphertext * S;
1195 gcry_mpi_t s_prime = NULL;
1196 struct GNUNET_CRYPTO_PaillierCiphertext * S_prime;
1200 count = request->used;
1202 b = GNUNET_malloc (sizeof (gcry_mpi_t) * count);
1203 a_pi = GNUNET_malloc (sizeof (gcry_mpi_t) * count);
1204 b_pi = GNUNET_malloc (sizeof (gcry_mpi_t) * count);
1205 a_pi_prime = GNUNET_malloc (sizeof (gcry_mpi_t) * count);
1206 rand_pi = GNUNET_malloc (sizeof (gcry_mpi_t) * count);
1207 rand_pi_prime = GNUNET_malloc (sizeof (gcry_mpi_t) * count);
1209 // convert responder session to from long to mpi
1210 for (i = 0, j = 0; i < response->total && j < count; i++)
1212 if (request->mask[i / 8] & (1 << (i % 8)))
1214 value = response->vector[i] >= 0 ? response->vector[i] : -response->vector[i];
1215 // long to gcry_mpi_t
1216 if (0 > response->vector[i])
1218 b[j] = gcry_mpi_new (0);
1219 gcry_mpi_sub_ui (b[j], b[j], value);
1222 b[j] = gcry_mpi_set_ui (NULL, value);
1227 GNUNET_free (response->vector);
1228 response->vector = NULL;
1232 // generate r, p and q
1233 rand = initialize_mpi_vector (count);
1234 for (i = 0; i < count; i++)
1238 svalue = (int32_t) GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK, UINT32_MAX);
1240 // long to gcry_mpi_t
1242 gcry_mpi_sub_ui (rand[i],
1246 rand[i] = gcry_mpi_set_ui (rand[i], svalue);
1248 p = GNUNET_CRYPTO_random_permute (GNUNET_CRYPTO_QUALITY_WEAK, count);
1249 q = GNUNET_CRYPTO_random_permute (GNUNET_CRYPTO_QUALITY_WEAK, count);
1250 //initialize the result vectors
1251 r = initialize_mpi_vector (count);
1252 r_prime = initialize_mpi_vector (count);
1254 // copy the REFERNCES of a, b and r into aq and bq. we will not change
1255 // those values, thus we can work with the references
1256 memcpy (a_pi, request->a, sizeof (gcry_mpi_t) * count);
1257 memcpy (a_pi_prime, request->a, sizeof (gcry_mpi_t) * count);
1258 memcpy (b_pi, b, sizeof (gcry_mpi_t) * count);
1259 memcpy (rand_pi, rand, sizeof (gcry_mpi_t) * count);
1260 memcpy (rand_pi_prime, rand, sizeof (gcry_mpi_t) * count);
1262 //todo get API-cryptoblocks, instead of MPI values
1264 // generate p and q permutations for a, b and r
1266 GNUNET_assert (permute_vector (a_pi, p, count));
1267 GNUNET_assert (permute_vector (b_pi, p, count));
1268 GNUNET_assert (permute_vector (rand_pi, p, count));
1269 GNUNET_assert (permute_vector (a_pi_prime, q, count));
1270 GNUNET_assert (permute_vector (rand_pi_prime, q, count));
1272 // encrypt the element
1273 // for the sake of readability I decided to have dedicated permutation
1274 // vectors, which get rid of all the lookups in p/q.
1275 // however, ap/aq are not absolutely necessary but are just abstraction
1276 // Calculate Kp = E(S + a_pi) (+) E(S - r_pi - b_pi)
1277 for (i = 0; i < count; i++)
1279 // E(S - r_pi - b_pi)
1280 gcry_mpi_sub (r[i], my_offset, rand_pi[i]);
1281 gcry_mpi_sub (r[i], r[i], b_pi[i]);
1282 GNUNET_CRYPTO_paillier_encrypt (&request->remote_pubkey,
1287 // E(S - r_pi - b_pi) * E(S + a_pi) == E(2*S + a - r - b)
1288 GNUNET_CRYPTO_paillier_hom_add (&request->remote_pubkey,
1295 GNUNET_free (rand_pi);
1297 // Calculate Kq = E(S + a_qi) (+) E(S - r_qi)
1298 for (i = 0; i < count; i++)
1301 gcry_mpi_sub (r_prime[i], my_offset, rand_pi_prime[i]);
1302 GNUNET_CRYPTO_paillier_encrypt (&request->remote_pubkey,
1307 // E(S - r_qi) * E(S + a_qi) == E(2*S + a_qi - r_qi)
1308 GNUNET_CRYPTO_paillier_hom_add (&request->remote_pubkey,
1314 GNUNET_free (a_pi_prime);
1315 GNUNET_free (rand_pi_prime);
1318 request->r_prime = r_prime;
1319 request->response = response;
1321 // Calculate S' = E(SUM( r_i^2 ))
1322 s_prime = compute_square_sum (rand, count);
1323 GNUNET_CRYPTO_paillier_encrypt (&request->remote_pubkey,
1328 // Calculate S = E(SUM( (r_i + b_i)^2 ))
1329 for (i = 0; i < count; i++) {
1330 gcry_mpi_add (rand[i], rand[i], b[i]);
1332 s = compute_square_sum (rand, count);
1333 GNUNET_CRYPTO_paillier_encrypt (&request->remote_pubkey,
1338 // release r and tmp
1339 for (i = 0; i < count; i++)
1340 // rp, rq, aq, ap, bp, bq are released along with a, r, b respectively, (a and b are handled at except:)
1341 gcry_mpi_release (rand[i]);
1343 // copy the r[], r_prime[], S and Stick into a new message, prepare_service_response frees these
1344 if (GNUNET_YES != prepare_service_response (S, S_prime, request))
1345 GNUNET_log (GNUNET_ERROR_TYPE_INFO, _ ("Failed to communicate with `%s', scalar product calculation aborted.\n"),
1346 GNUNET_i2s (&request->peer));
1351 for (i = 0; i < count; i++)
1353 gcry_mpi_release (b[i]);
1354 gcry_mpi_release (request->a[i]);
1358 GNUNET_free (request->a);
1360 GNUNET_free_non_null (p);
1361 GNUNET_free_non_null (q);
1368 * Send a multi part chunk of a service request from alice to bob.
1369 * This element only contains a part of the elements-vector (session->a[]),
1370 * mask and public key set have to be contained within the first message
1372 * This allows a ~32kbit key length while using 32000 elements or 62000 elements per request.
1374 * @param cls the associated service session
1377 prepare_service_request_multipart (void *cls)
1379 struct ServiceSession * session = cls;
1380 unsigned char * current;
1381 unsigned char * element_exported;
1382 struct GNUNET_SCALARPRODUCT_multipart_message * msg;
1385 uint32_t msg_length;
1386 uint32_t todo_count;
1387 size_t element_length = 0; // initialized by gcry_mpi_print, but the compiler doesn't know that
1391 msg_length = sizeof (struct GNUNET_SCALARPRODUCT_multipart_message);
1392 todo_count = session->used - session->transferred;
1394 if (todo_count > MULTIPART_ELEMENT_CAPACITY)
1395 // send the currently possible maximum chunk
1396 todo_count = MULTIPART_ELEMENT_CAPACITY;
1398 msg_length += todo_count * PAILLIER_ELEMENT_LENGTH;
1399 msg = GNUNET_malloc (msg_length);
1400 msg->header.type = htons (GNUNET_MESSAGE_TYPE_SCALARPRODUCT_ALICE_TO_BOB_MULTIPART);
1401 msg->header.size = htons (msg_length);
1402 msg->multipart_element_count = htonl (todo_count);
1404 element_exported = GNUNET_malloc (PAILLIER_ELEMENT_LENGTH);
1405 a = gcry_mpi_new (KEYBITS * 2);
1406 current = (unsigned char *) &msg[1];
1407 // encrypt our vector and generate string representations
1408 for (i = session->last_processed, j = 0; i < session->total; i++)
1410 // is this a used element?
1411 if (session->mask[i / 8] & 1 << (i % 8)) {
1412 if (todo_count <= j)
1413 break; //reached end of this message, can't include more
1415 memset (element_exported, 0, PAILLIER_ELEMENT_LENGTH);
1416 value = session->vector[i] >= 0 ? session->vector[i] : -session->vector[i];
1418 a = gcry_mpi_set_ui (a, 0);
1419 // long to gcry_mpi_t
1420 if (session->vector[i] < 0)
1421 gcry_mpi_sub_ui (a, a, value);
1423 gcry_mpi_add_ui (a, a, value);
1425 session->a[session->transferred + j++] = gcry_mpi_set (NULL, a);
1426 gcry_mpi_add (a, a, my_offset);
1427 encrypt_element (a, a, my_g, my_n, my_nsquare);
1429 // get representation as string
1430 // we always supply some value, so gcry_mpi_print fails only if it can't reserve memory
1431 GNUNET_assert (!gcry_mpi_print (GCRYMPI_FMT_USG,
1432 element_exported, PAILLIER_ELEMENT_LENGTH,
1436 // move buffer content to the end of the buffer so it can easily be read by libgcrypt. also this now has fixed size
1437 adjust (element_exported, element_length, PAILLIER_ELEMENT_LENGTH);
1439 // copy over to the message
1440 memcpy (current, element_exported, PAILLIER_ELEMENT_LENGTH);
1441 current += PAILLIER_ELEMENT_LENGTH;
1444 gcry_mpi_release (a);
1445 GNUNET_free (element_exported);
1446 session->transferred += todo_count;
1448 session->msg = (struct GNUNET_MessageHeader *) msg;
1449 GNUNET_log (GNUNET_ERROR_TYPE_INFO, _ ("Transmitting service request.\n"));
1451 //transmit via mesh messaging
1452 session->service_transmit_handle = GNUNET_MESH_notify_transmit_ready (session->channel, GNUNET_YES,
1453 GNUNET_TIME_UNIT_FOREVER_REL,
1457 if (!session->service_transmit_handle) {
1458 GNUNET_log (GNUNET_ERROR_TYPE_ERROR, _ ("Could not send service-request multipart message to channel!\n"));
1460 session->msg = NULL;
1461 session->client_notification_task =
1462 GNUNET_SCHEDULER_add_now (&prepare_client_end_notification,
1466 if (session->transferred != session->used) {
1467 session->last_processed = i;
1471 session->state = WAITING_FOR_SERVICE_RESPONSE;
1476 * Executed by Alice, fills in a service-request message and sends it to the given peer
1478 * @param cls the session associated with this request
1479 * @param tc task context handed over by scheduler, unsued
1482 prepare_service_request (void *cls,
1483 const struct GNUNET_SCHEDULER_TaskContext *tc)
1485 struct ServiceSession * session = cls;
1486 unsigned char * current;
1487 unsigned char * element_exported;
1488 struct GNUNET_SCALARPRODUCT_service_request * msg;
1491 uint32_t msg_length;
1492 size_t element_length = 0; // initialized by gcry_mpi_print, but the compiler doesn't know that
1496 session->service_request_task = GNUNET_SCHEDULER_NO_TASK;
1498 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, _ ("Successfully created new channel to peer (%s)!\n"), GNUNET_i2s (&session->peer));
1500 msg_length = sizeof (struct GNUNET_SCALARPRODUCT_service_request)
1501 +session->mask_length
1502 + my_pubkey_external_length;
1504 if (GNUNET_SERVER_MAX_MESSAGE_SIZE > msg_length + session->used * PAILLIER_ELEMENT_LENGTH) {
1505 msg_length += session->used * PAILLIER_ELEMENT_LENGTH;
1506 session->transferred = session->used;
1509 //create a multipart msg, first we calculate a new msg size for the head msg
1510 session->transferred = (GNUNET_SERVER_MAX_MESSAGE_SIZE - 1 - msg_length) / PAILLIER_ELEMENT_LENGTH;
1513 msg = GNUNET_malloc (msg_length);
1514 msg->header.type = htons (GNUNET_MESSAGE_TYPE_SCALARPRODUCT_ALICE_TO_BOB);
1515 msg->total_element_count = htonl (session->used);
1516 msg->contained_element_count = htonl (session->transferred);
1517 memcpy (&msg->key, &session->key, sizeof (struct GNUNET_HashCode));
1518 msg->mask_length = htonl (session->mask_length);
1519 msg->pk_length = htonl (my_pubkey_external_length);
1520 msg->element_count = htonl (session->total);
1521 msg->header.size = htons (msg_length);
1523 // fill in the payload
1524 current = (unsigned char *) &msg[1];
1525 // copy over the mask
1526 memcpy (current, session->mask, session->mask_length);
1527 // copy over our public key
1528 current += session->mask_length;
1529 memcpy (current, my_pubkey_external, my_pubkey_external_length);
1530 current += my_pubkey_external_length;
1532 // now copy over the element vector
1533 element_exported = GNUNET_malloc (PAILLIER_ELEMENT_LENGTH);
1534 session->a = GNUNET_malloc (sizeof (gcry_mpi_t) * session->used);
1535 a = gcry_mpi_new (KEYBITS * 2);
1536 // encrypt our vector and generate string representations
1537 for (i = 0, j = 0; i < session->total; i++) {
1538 // if this is a used element...
1539 if (session->mask[i / 8] & 1 << (i % 8)) {
1540 if (session->transferred <= j)
1541 break; //reached end of this message, can't include more
1543 memset (element_exported, 0, PAILLIER_ELEMENT_LENGTH);
1544 value = session->vector[i] >= 0 ? session->vector[i] : -session->vector[i];
1546 a = gcry_mpi_set_ui (a, 0);
1547 // long to gcry_mpi_t
1548 if (session->vector[i] < 0)
1549 gcry_mpi_sub_ui (a, a, value);
1551 gcry_mpi_add_ui (a, a, value);
1553 session->a[j++] = gcry_mpi_set (NULL, a);
1554 gcry_mpi_add (a, a, my_offset);
1555 encrypt_element (a, a, my_g, my_n, my_nsquare);
1557 // get representation as string
1558 // we always supply some value, so gcry_mpi_print fails only if it can't reserve memory
1559 GNUNET_assert (!gcry_mpi_print (GCRYMPI_FMT_USG,
1560 element_exported, PAILLIER_ELEMENT_LENGTH,
1564 // move buffer content to the end of the buffer so it can easily be read by libgcrypt. also this now has fixed size
1565 adjust (element_exported, element_length, PAILLIER_ELEMENT_LENGTH);
1567 // copy over to the message
1568 memcpy (current, element_exported, PAILLIER_ELEMENT_LENGTH);
1569 current += PAILLIER_ELEMENT_LENGTH;
1572 gcry_mpi_release (a);
1573 GNUNET_free (element_exported);
1575 session->msg = (struct GNUNET_MessageHeader *) msg;
1576 GNUNET_log (GNUNET_ERROR_TYPE_INFO, _ ("Transmitting service request.\n"));
1578 //transmit via mesh messaging
1579 session->service_transmit_handle = GNUNET_MESH_notify_transmit_ready (session->channel, GNUNET_YES,
1580 GNUNET_TIME_UNIT_FOREVER_REL,
1584 if (!session->service_transmit_handle) {
1585 GNUNET_log (GNUNET_ERROR_TYPE_ERROR, _ ("Could not send message to channel!\n"));
1587 session->msg = NULL;
1588 session->client_notification_task =
1589 GNUNET_SCHEDULER_add_now (&prepare_client_end_notification,
1593 if (session->transferred != session->used) {
1594 session->state = WAITING_FOR_MULTIPART_TRANSMISSION;
1595 session->last_processed = i;
1598 //singlepart message
1599 session->state = WAITING_FOR_SERVICE_RESPONSE;
1604 * Handler for a client request message.
1605 * Can either be type A or B
1606 * A: request-initiation to compute a scalar product with a peer
1607 * B: response role, keep the values + session and wait for a matching session or process a waiting request
1609 * @param cls closure
1610 * @param client identification of the client
1611 * @param message the actual message
1614 handle_client_request (void *cls,
1615 struct GNUNET_SERVER_Client *client,
1616 const struct GNUNET_MessageHeader *message)
1618 const struct GNUNET_SCALARPRODUCT_client_request * msg = (const struct GNUNET_SCALARPRODUCT_client_request *) message;
1619 struct ServiceSession * session;
1620 uint32_t element_count;
1621 uint32_t mask_length;
1626 // only one concurrent session per client connection allowed, simplifies logics a lot...
1627 session = GNUNET_SERVER_client_get_user_context (client, struct ServiceSession);
1628 if ((NULL != session) && (session->state != FINALIZED)) {
1629 GNUNET_SERVER_receive_done (client, GNUNET_OK);
1632 else if (NULL != session) {
1633 // old session is already completed, clean it up
1634 GNUNET_CONTAINER_DLL_remove (from_client_head, from_client_tail, session);
1635 free_session_variables (session);
1636 GNUNET_free (session);
1639 //we need at least a peer and one message id to compare
1640 if (sizeof (struct GNUNET_SCALARPRODUCT_client_request) > ntohs (msg->header.size)) {
1641 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
1642 _ ("Too short message received from client!\n"));
1643 GNUNET_SERVER_receive_done (client, GNUNET_SYSERR);
1647 msg_type = ntohs (msg->header.type);
1648 element_count = ntohl (msg->element_count);
1649 mask_length = ntohl (msg->mask_length);
1651 //sanity check: is the message as long as the message_count fields suggests?
1652 if ((ntohs (msg->header.size) != (sizeof (struct GNUNET_SCALARPRODUCT_client_request) +element_count * sizeof (int32_t) + mask_length))
1653 || (0 == element_count)) {
1654 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
1655 _("Invalid message received from client, session information incorrect!\n"));
1656 GNUNET_SERVER_receive_done (client, GNUNET_SYSERR);
1660 // do we have a duplicate session here already?
1661 if (NULL != find_matching_session (from_client_tail,
1665 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
1666 _("Duplicate session information received, cannot create new session with key `%s'\n"),
1667 GNUNET_h2s (&msg->key));
1668 GNUNET_SERVER_receive_done (client, GNUNET_SYSERR);
1672 session = GNUNET_new (struct ServiceSession);
1673 session->service_request_task = GNUNET_SCHEDULER_NO_TASK;
1674 session->client_notification_task = GNUNET_SCHEDULER_NO_TASK;
1675 session->client = client;
1676 session->total = element_count;
1677 session->mask_length = mask_length;
1678 // get our transaction key
1679 memcpy (&session->key, &msg->key, sizeof (struct GNUNET_HashCode));
1680 //allocate memory for vector and encrypted vector
1681 session->vector = GNUNET_malloc (sizeof (int32_t) * element_count);
1682 vector = (int32_t *) & msg[1];
1684 if (GNUNET_MESSAGE_TYPE_SCALARPRODUCT_CLIENT_TO_ALICE == msg_type)
1686 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1687 _("Got client-request-session with key %s, preparing channel to remote service.\n"),
1688 GNUNET_h2s (&session->key));
1690 session->role = ALICE;
1692 session->mask = GNUNET_malloc (mask_length);
1693 memcpy (session->mask, &vector[element_count], mask_length);
1695 // copy over the elements
1697 for (i = 0; i < element_count; i++)
1699 session->vector[i] = ntohl (vector[i]);
1700 if (session->vector[i] == 0)
1701 session->mask[i / 8] &= ~(1 << (i % 8));
1702 if (session->mask[i / 8] & (1 << (i % 8)))
1706 if (0 == session->used)
1708 GNUNET_break_op (0);
1709 GNUNET_free (session->vector);
1710 GNUNET_free (session);
1711 GNUNET_SERVER_receive_done (client, GNUNET_SYSERR);
1714 //session with ourself makes no sense!
1715 if (!memcmp (&msg->peer, &me, sizeof (struct GNUNET_PeerIdentity)))
1718 GNUNET_free (session->vector);
1719 GNUNET_free (session);
1720 GNUNET_SERVER_receive_done (client, GNUNET_SYSERR);
1724 memcpy (&session->peer, &msg->peer, sizeof (struct GNUNET_PeerIdentity));
1725 GNUNET_log (GNUNET_ERROR_TYPE_INFO,
1726 _ ("Creating new channel for session with key %s.\n"),
1727 GNUNET_h2s (&session->key));
1728 session->channel = GNUNET_MESH_channel_create (my_mesh, session,
1730 GNUNET_APPLICATION_TYPE_SCALARPRODUCT,
1731 GNUNET_MESH_OPTION_RELIABLE);
1732 //prepare_service_request, channel_peer_disconnect_handler,
1733 if (!session->channel) {
1735 GNUNET_free (session->vector);
1736 GNUNET_free (session);
1737 GNUNET_SERVER_receive_done (client, GNUNET_SYSERR);
1740 GNUNET_SERVER_client_set_user_context (client, session);
1741 GNUNET_CONTAINER_DLL_insert (from_client_head, from_client_tail, session);
1743 session->state = CLIENT_REQUEST_RECEIVED;
1744 session->service_request_task =
1745 GNUNET_SCHEDULER_add_now (&prepare_service_request,
1751 struct ServiceSession * requesting_session;
1752 enum SessionState needed_state = SERVICE_REQUEST_RECEIVED;
1754 session->role = BOB;
1755 session->mask = NULL;
1756 // copy over the elements
1757 session->used = element_count;
1758 for (i = 0; i < element_count; i++)
1759 session->vector[i] = ntohl (vector[i]);
1760 session->state = CLIENT_RESPONSE_RECEIVED;
1762 GNUNET_SERVER_client_set_user_context (client, session);
1763 GNUNET_CONTAINER_DLL_insert (from_client_head, from_client_tail, session);
1765 //check if service queue contains a matching request
1766 requesting_session = find_matching_session (from_service_tail,
1769 &needed_state, NULL);
1770 if (NULL != requesting_session)
1772 GNUNET_log (GNUNET_ERROR_TYPE_INFO,
1773 _("Got client-responder-session with key %s and a matching service-request-session set, processing.\n"),
1774 GNUNET_h2s (&session->key));
1775 if (GNUNET_OK != compute_service_response (requesting_session, session))
1776 session->client_notification_task =
1777 GNUNET_SCHEDULER_add_now (&prepare_client_end_notification,
1783 GNUNET_log (GNUNET_ERROR_TYPE_INFO,
1784 _("Got client-responder-session with key %s but NO matching service-request-session set, queuing element for later use.\n"),
1785 GNUNET_h2s (&session->key));
1786 // no matching session exists yet, store the response
1787 // for later processing by handle_service_request()
1790 GNUNET_SERVER_receive_done (client, GNUNET_YES);
1795 * Function called for inbound channels.
1797 * @param cls closure
1798 * @param channel new handle to the channel
1799 * @param initiator peer that started the channel
1800 * @param port unused
1801 * @param options unused
1803 * @return session associated with the channel
1806 channel_incoming_handler (void *cls,
1807 struct GNUNET_MESH_Channel *channel,
1808 const struct GNUNET_PeerIdentity *initiator,
1809 uint32_t port, enum GNUNET_MESH_ChannelOption options)
1811 struct ServiceSession * c = GNUNET_new (struct ServiceSession);
1813 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1814 _("New incoming channel from peer %s.\n"),
1815 GNUNET_i2s (initiator));
1817 c->peer = *initiator;
1818 c->channel = channel;
1820 c->state = WAITING_FOR_SERVICE_REQUEST;
1826 * Function called whenever a channel is destroyed. Should clean up
1827 * any associated state.
1829 * It must NOT call GNUNET_MESH_channel_destroy on the channel.
1831 * @param cls closure (set from GNUNET_MESH_connect)
1832 * @param channel connection to the other end (henceforth invalid)
1833 * @param channel_ctx place where local state associated
1834 * with the channel is stored
1837 channel_destruction_handler (void *cls,
1838 const struct GNUNET_MESH_Channel *channel,
1841 struct ServiceSession * session = channel_ctx;
1842 struct ServiceSession * client_session;
1843 struct ServiceSession * curr;
1845 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1846 _ ("Peer disconnected, terminating session %s with peer (%s)\n"),
1847 GNUNET_h2s (&session->key),
1848 GNUNET_i2s (&session->peer));
1849 if (ALICE == session->role) {
1850 // as we have only one peer connected in each session, just remove the session
1852 if ((SERVICE_RESPONSE_RECEIVED > session->state) && (!do_shutdown)) {
1853 session->channel = NULL;
1854 // if this happened before we received the answer, we must terminate the session
1855 session->client_notification_task =
1856 GNUNET_SCHEDULER_add_now (&prepare_client_end_notification,
1860 else { //(BOB == session->role) service session
1861 // remove the session, unless it has already been dequeued, but somehow still active
1862 // this could bug without the IF in case the queue is empty and the service session was the only one know to the service
1863 // scenario: disconnect before alice can send her message to bob.
1864 for (curr = from_service_head; NULL != curr; curr = curr->next)
1865 if (curr == session) {
1866 GNUNET_CONTAINER_DLL_remove (from_service_head, from_service_tail, curr);
1869 // there is a client waiting for this service session, terminate it, too!
1870 // i assume the tupel of key and element count is unique. if it was not the rest of the code would not work either.
1871 client_session = find_matching_session (from_client_tail,
1875 free_session_variables (session);
1876 GNUNET_free (session);
1878 // the client has to check if it was waiting for a result
1879 // or if it was a responder, no point in adding more statefulness
1880 if (client_session && (!do_shutdown)) {
1881 client_session->state = FINALIZED;
1882 client_session->client_notification_task =
1883 GNUNET_SCHEDULER_add_now (&prepare_client_end_notification,
1891 * Compute our scalar product, done by Alice
1893 * @param session - the session associated with this computation
1894 * @return product as MPI, never NULL
1897 compute_scalar_product (struct ServiceSession * session)
1908 count = session->used;
1909 // due to the introduced static offset S, we now also have to remove this
1910 // from the E(a_pi)(+)E(-b_pi-r_pi) and E(a_qi)(+)E(-r_qi) twice each,
1911 // the result is E((S + a_pi) + (S -b_pi-r_pi)) and E(S + a_qi + S - r_qi)
1912 for (i = 0; i < count; i++)
1914 decrypt_element (session->r[i], session->r[i], my_mu, my_lambda, my_n, my_nsquare);
1915 gcry_mpi_sub (session->r[i], session->r[i], my_offset);
1916 gcry_mpi_sub (session->r[i], session->r[i], my_offset);
1917 decrypt_element (session->r_prime[i], session->r_prime[i], my_mu, my_lambda, my_n, my_nsquare);
1918 gcry_mpi_sub (session->r_prime[i], session->r_prime[i], my_offset);
1919 gcry_mpi_sub (session->r_prime[i], session->r_prime[i], my_offset);
1922 // calculate t = sum(ai)
1923 t = compute_square_sum (session->a, count);
1926 u = gcry_mpi_new (0);
1927 tmp = compute_square_sum (session->r, count);
1928 gcry_mpi_sub (u, u, tmp);
1929 gcry_mpi_release (tmp);
1932 u_prime = gcry_mpi_new (0);
1933 tmp = compute_square_sum (session->r_prime, count);
1934 gcry_mpi_sub (u_prime, u_prime, tmp);
1936 GNUNET_assert (p = gcry_mpi_new (0));
1937 GNUNET_assert (p_prime = gcry_mpi_new (0));
1940 decrypt_element (session->s, session->s, my_mu, my_lambda, my_n, my_nsquare);
1941 decrypt_element (session->s_prime, session->s_prime, my_mu, my_lambda, my_n, my_nsquare);
1944 gcry_mpi_add (p, session->s, t);
1945 gcry_mpi_add (p, p, u);
1948 gcry_mpi_add (p_prime, session->s_prime, t);
1949 gcry_mpi_add (p_prime, p_prime, u_prime);
1951 gcry_mpi_release (t);
1952 gcry_mpi_release (u);
1953 gcry_mpi_release (u_prime);
1956 gcry_mpi_sub (p, p, p_prime);
1957 gcry_mpi_release (p_prime);
1958 tmp = gcry_mpi_set_ui (tmp, 2);
1959 gcry_mpi_div (p, NULL, p, tmp, 0);
1961 gcry_mpi_release (tmp);
1962 for (i = 0; i < count; i++)
1963 gcry_mpi_release (session->a[i]);
1964 GNUNET_free (session->a);
1972 * Handle a multipart-chunk of a request from another service to calculate a scalarproduct with us.
1974 * @param cls closure (set from #GNUNET_MESH_connect)
1975 * @param channel connection to the other end
1976 * @param channel_ctx place to store local state associated with the channel
1977 * @param message the actual message
1978 * @return #GNUNET_OK to keep the connection open,
1979 * #GNUNET_SYSERR to close it (signal serious error)
1982 handle_service_request_multipart (void *cls,
1983 struct GNUNET_MESH_Channel * channel,
1985 const struct GNUNET_MessageHeader * message)
1987 struct ServiceSession * session;
1988 const struct GNUNET_SCALARPRODUCT_multipart_message * msg = (const struct GNUNET_SCALARPRODUCT_multipart_message *) message;
1989 uint32_t used_elements;
1990 uint32_t contained_elements = 0;
1991 uint32_t msg_length;
1992 unsigned char * current;
1996 // are we in the correct state?
1997 session = (struct ServiceSession *) * channel_ctx;
1998 if ((BOB != session->role) || (WAITING_FOR_MULTIPART_TRANSMISSION != session->state)) {
2001 // shorter than minimum?
2002 if (ntohs (msg->header.size) <= sizeof (struct GNUNET_SCALARPRODUCT_multipart_message)) {
2005 used_elements = session->used;
2006 contained_elements = ntohl (msg->multipart_element_count);
2007 msg_length = sizeof (struct GNUNET_SCALARPRODUCT_multipart_message)
2008 +contained_elements * PAILLIER_ELEMENT_LENGTH;
2010 if ((ntohs (msg->header.size) != msg_length)
2011 || (used_elements < contained_elements + session->transferred)) {
2014 current = (unsigned char *) &msg[1];
2015 if (contained_elements != 0) {
2016 // Convert each vector element to MPI_value
2017 for (i = session->transferred; i < session->transferred + contained_elements; i++) {
2019 if (0 != (rc = gcry_mpi_scan (&session->a[i],
2021 ¤t[i * PAILLIER_ELEMENT_LENGTH],
2022 PAILLIER_ELEMENT_LENGTH,
2024 LOG_GCRY (GNUNET_ERROR_TYPE_DEBUG, "gcry_mpi_scan", rc);
2028 session->transferred += contained_elements;
2030 if (session->transferred == used_elements)
2032 // single part finished
2033 session->state = SERVICE_REQUEST_RECEIVED;
2034 if (session->response)
2036 GNUNET_log (GNUNET_ERROR_TYPE_INFO,
2037 _ ("Got session with key %s and a matching element set, processing.\n"),
2038 GNUNET_h2s (&session->key));
2039 if (GNUNET_OK != compute_service_response (session, session->response)) {
2040 //something went wrong, remove it again...
2045 GNUNET_log (GNUNET_ERROR_TYPE_INFO,
2046 _("Got session with key %s without a matching element set, queueing.\n"),
2047 GNUNET_h2s (&session->key));
2051 // multipart message
2057 // and notify our client-session that we could not complete the session
2058 GNUNET_CONTAINER_DLL_remove (from_service_head, from_service_tail, session);
2059 if (session->response)
2060 // we just found the responder session in this queue
2061 session->response->client_notification_task =
2062 GNUNET_SCHEDULER_add_now (&prepare_client_end_notification,
2064 free_session_variables (session);
2065 GNUNET_free (session);
2066 return GNUNET_SYSERR;
2071 * Handle a request from another service to calculate a scalarproduct with us.
2073 * @param cls closure (set from #GNUNET_MESH_connect)
2074 * @param channel connection to the other end
2075 * @param channel_ctx place to store local state associated with the channel
2076 * @param message the actual message
2077 * @return #GNUNET_OK to keep the connection open,
2078 * #GNUNET_SYSERR to close it (signal serious error)
2081 handle_service_request (void *cls,
2082 struct GNUNET_MESH_Channel * channel,
2084 const struct GNUNET_MessageHeader * message)
2086 struct ServiceSession * session;
2087 const struct GNUNET_SCALARPRODUCT_service_request * msg = (const struct GNUNET_SCALARPRODUCT_service_request *) message;
2088 uint32_t mask_length;
2090 uint32_t used_elements;
2091 uint32_t contained_elements = 0;
2092 uint32_t element_count;
2093 uint32_t msg_length;
2094 unsigned char * current;
2097 enum SessionState needed_state;
2099 session = (struct ServiceSession *) * channel_ctx;
2100 if (WAITING_FOR_SERVICE_REQUEST != session->state) {
2103 // Check if message was sent by me, which would be bad!
2104 if (!memcmp (&session->peer, &me, sizeof (struct GNUNET_PeerIdentity))) {
2105 GNUNET_free (session);
2107 return GNUNET_SYSERR;
2109 // shorter than expected?
2110 if (ntohs (msg->header.size) < sizeof (struct GNUNET_SCALARPRODUCT_service_request)) {
2111 GNUNET_free (session);
2112 GNUNET_break_op (0);
2113 return GNUNET_SYSERR;
2115 mask_length = ntohl (msg->mask_length);
2116 pk_length = ntohl (msg->pk_length);
2117 used_elements = ntohl (msg->total_element_count);
2118 contained_elements = ntohl (msg->contained_element_count);
2119 element_count = ntohl (msg->element_count);
2120 msg_length = sizeof (struct GNUNET_SCALARPRODUCT_service_request)
2121 +mask_length + pk_length + contained_elements * PAILLIER_ELEMENT_LENGTH;
2123 //sanity check: is the message as long as the message_count fields suggests?
2124 if ( (ntohs (msg->header.size) != msg_length) ||
2125 (element_count < used_elements) ||
2126 (used_elements < contained_elements) ||
2127 (0 == used_elements) ||
2128 (mask_length != (element_count / 8 + ((element_count % 8) ? 1 : 0))) )
2130 GNUNET_free (session);
2131 GNUNET_break_op (0);
2132 return GNUNET_SYSERR;
2134 if (find_matching_session (from_service_tail,
2140 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
2141 _ ("Got message with duplicate session key (`%s'), ignoring service request.\n"),
2142 (const char *) &(msg->key));
2143 GNUNET_free (session);
2144 return GNUNET_SYSERR;
2147 session->total = element_count;
2148 session->used = used_elements;
2149 session->transferred = contained_elements;
2150 session->channel = channel;
2153 memcpy (&session->key, &msg->key, sizeof (struct GNUNET_HashCode));
2154 current = (unsigned char *) &msg[1];
2155 //preserve the mask, we will need that later on
2156 session->mask = GNUNET_malloc (mask_length);
2157 memcpy (session->mask, current, mask_length);
2159 current += mask_length;
2161 //convert the publickey to sexp
2162 if (0 != (rc = gcry_sexp_new (&session->remote_pubkey, current, pk_length, 1))) {
2163 LOG_GCRY (GNUNET_ERROR_TYPE_DEBUG, "gcry_sexp_new", rc);
2164 GNUNET_free (session->mask);
2165 GNUNET_free (session);
2166 return GNUNET_SYSERR;
2168 current += pk_length;
2169 //check if service queue contains a matching request
2170 needed_state = CLIENT_RESPONSE_RECEIVED;
2171 session->response = find_matching_session (from_client_tail,
2174 &needed_state, NULL);
2176 session->a = GNUNET_malloc (sizeof (gcry_mpi_t) * used_elements);
2177 session->state = WAITING_FOR_MULTIPART_TRANSMISSION;
2178 GNUNET_CONTAINER_DLL_insert (from_service_head, from_service_tail, session);
2179 if (contained_elements != 0) {
2180 // Convert each vector element to MPI_value
2181 for (i = 0; i < contained_elements; i++) {
2183 if (0 != (rc = gcry_mpi_scan (&session->a[i],
2185 ¤t[i * PAILLIER_ELEMENT_LENGTH],
2186 PAILLIER_ELEMENT_LENGTH,
2188 LOG_GCRY (GNUNET_ERROR_TYPE_DEBUG, "gcry_mpi_scan", rc);
2192 if (contained_elements == used_elements) {
2193 // single part finished
2194 session->state = SERVICE_REQUEST_RECEIVED;
2195 if (session->response) {
2196 GNUNET_log (GNUNET_ERROR_TYPE_INFO, _ ("Got session with key %s and a matching element set, processing.\n"), GNUNET_h2s (&session->key));
2197 if (GNUNET_OK != compute_service_response (session, session->response)) {
2198 //something went wrong, remove it again...
2203 GNUNET_log (GNUNET_ERROR_TYPE_INFO, _ ("Got session with key %s without a matching element set, queueing.\n"), GNUNET_h2s (&session->key));
2206 // multipart message
2211 GNUNET_break_op (0);
2212 if ((NULL != session->next) || (NULL != session->prev) || (from_service_head == session))
2213 GNUNET_CONTAINER_DLL_remove (from_service_head, from_service_tail, session);
2214 // and notify our client-session that we could not complete the session
2215 if (session->response)
2216 // we just found the responder session in this queue
2217 session->response->client_notification_task =
2218 GNUNET_SCHEDULER_add_now (&prepare_client_end_notification,
2220 free_session_variables (session);
2221 return GNUNET_SYSERR;
2226 * Handle a multipart chunk of a response we got from another service we wanted to calculate a scalarproduct with.
2228 * @param cls closure (set from #GNUNET_MESH_connect)
2229 * @param channel connection to the other end
2230 * @param channel_ctx place to store local state associated with the channel
2231 * @param message the actual message
2232 * @return #GNUNET_OK to keep the connection open,
2233 * #GNUNET_SYSERR to close it (signal serious error)
2236 handle_service_response_multipart (void *cls,
2237 struct GNUNET_MESH_Channel * channel,
2239 const struct GNUNET_MessageHeader * message)
2241 struct ServiceSession * session;
2242 const struct GNUNET_SCALARPRODUCT_multipart_message * msg = (const struct GNUNET_SCALARPRODUCT_multipart_message *) message;
2243 unsigned char * current;
2246 uint32_t contained = 0;
2248 size_t required_size;
2251 GNUNET_assert (NULL != message);
2252 // are we in the correct state?
2253 session = (struct ServiceSession *) * channel_ctx;
2254 if ((ALICE != session->role) || (WAITING_FOR_MULTIPART_TRANSMISSION != session->state)) {
2257 msg_size = ntohs (msg->header.size);
2258 required_size = sizeof (struct GNUNET_SCALARPRODUCT_multipart_message) + 2 * PAILLIER_ELEMENT_LENGTH;
2259 // shorter than minimum?
2260 if (required_size > msg_size) {
2263 contained = ntohl (msg->multipart_element_count);
2264 required_size = sizeof (struct GNUNET_SCALARPRODUCT_multipart_message)
2265 + 2 * contained * PAILLIER_ELEMENT_LENGTH;
2266 //sanity check: is the message as long as the message_count fields suggests?
2267 if ((required_size != msg_size) || (session->used < session->transferred + contained)) {
2270 current = (unsigned char *) &msg[1];
2271 // Convert each k[][perm] to its MPI_value
2272 for (i = 0; i < contained; i++) {
2273 if (0 != (rc = gcry_mpi_scan (&session->r[i], GCRYMPI_FMT_USG, current,
2274 PAILLIER_ELEMENT_LENGTH, &read))) {
2275 LOG_GCRY (GNUNET_ERROR_TYPE_DEBUG, "gcry_mpi_scan", rc);
2278 current += PAILLIER_ELEMENT_LENGTH;
2279 if (0 != (rc = gcry_mpi_scan (&session->r_prime[i], GCRYMPI_FMT_USG, current,
2280 PAILLIER_ELEMENT_LENGTH, &read))) {
2281 LOG_GCRY (GNUNET_ERROR_TYPE_DEBUG, "gcry_mpi_scan", rc);
2284 current += PAILLIER_ELEMENT_LENGTH;
2286 session->transferred += contained;
2287 if (session->transferred != session->used)
2289 session->state = SERVICE_RESPONSE_RECEIVED;
2290 session->product = compute_scalar_product (session); //never NULL
2293 GNUNET_break_op (NULL != session->product);
2295 // send message with product to client
2296 if (ALICE == session->role){
2297 session->state = FINALIZED;
2298 session->channel = NULL;
2299 session->client_notification_task =
2300 GNUNET_SCHEDULER_add_now (&prepare_client_response,
2303 // the channel has done its job, terminate our connection and the channel
2304 // the peer will be notified that the channel was destroyed via channel_destruction_handler
2305 // just close the connection, as recommended by Christian
2306 return GNUNET_SYSERR;
2311 * Handle a response we got from another service we wanted to calculate a scalarproduct with.
2313 * @param cls closure (set from #GNUNET_MESH_connect)
2314 * @param channel connection to the other end
2315 * @param channel_ctx place to store local state associated with the channel
2316 * @param message the actual message
2317 * @return #GNUNET_OK to keep the connection open,
2318 * #GNUNET_SYSERR to close it (we are done)
2321 handle_service_response (void *cls,
2322 struct GNUNET_MESH_Channel * channel,
2324 const struct GNUNET_MessageHeader * message)
2326 struct ServiceSession * session;
2327 const struct GNUNET_SCALARPRODUCT_service_response * msg = (const struct GNUNET_SCALARPRODUCT_service_response *) message;
2328 unsigned char * current;
2331 uint32_t contained = 0;
2333 size_t required_size;
2336 GNUNET_assert (NULL != message);
2337 session = (struct ServiceSession *) * channel_ctx;
2338 // are we in the correct state?
2339 if (WAITING_FOR_SERVICE_RESPONSE != session->state) {
2342 //we need at least a full message without elements attached
2343 msg_size = ntohs (msg->header.size);
2344 required_size = sizeof (struct GNUNET_SCALARPRODUCT_service_response) + 2 * PAILLIER_ELEMENT_LENGTH;
2346 if (required_size > msg_size) {
2349 contained = ntohl (msg->contained_element_count);
2350 required_size = sizeof (struct GNUNET_SCALARPRODUCT_service_response)
2351 + 2 * contained * PAILLIER_ELEMENT_LENGTH
2352 + 2 * PAILLIER_ELEMENT_LENGTH;
2353 //sanity check: is the message as long as the message_count fields suggests?
2354 if ((msg_size != required_size) || (session->used < contained)) {
2357 session->state = WAITING_FOR_MULTIPART_TRANSMISSION;
2358 session->transferred = contained;
2360 current = (unsigned char *) &msg[1];
2361 if (0 != (rc = gcry_mpi_scan (&session->s, GCRYMPI_FMT_USG, current,
2362 PAILLIER_ELEMENT_LENGTH, &read))) {
2363 LOG_GCRY (GNUNET_ERROR_TYPE_DEBUG, "gcry_mpi_scan", rc);
2366 current += PAILLIER_ELEMENT_LENGTH;
2368 if (0 != (rc = gcry_mpi_scan (&session->s_prime, GCRYMPI_FMT_USG, current,
2369 PAILLIER_ELEMENT_LENGTH, &read))) {
2370 LOG_GCRY (GNUNET_ERROR_TYPE_DEBUG, "gcry_mpi_scan", rc);
2373 current += PAILLIER_ELEMENT_LENGTH;
2374 session->r = GNUNET_malloc (sizeof (gcry_mpi_t) * session->used);
2375 session->r_prime = GNUNET_malloc (sizeof (gcry_mpi_t) * session->used);
2376 // Convert each k[][perm] to its MPI_value
2377 for (i = 0; i < contained; i++) {
2378 if (0 != (rc = gcry_mpi_scan (&session->r[i], GCRYMPI_FMT_USG, current,
2379 PAILLIER_ELEMENT_LENGTH, &read))) {
2380 LOG_GCRY (GNUNET_ERROR_TYPE_DEBUG, "gcry_mpi_scan", rc);
2383 current += PAILLIER_ELEMENT_LENGTH;
2384 if (0 != (rc = gcry_mpi_scan (&session->r_prime[i], GCRYMPI_FMT_USG, current,
2385 PAILLIER_ELEMENT_LENGTH, &read))) {
2386 LOG_GCRY (GNUNET_ERROR_TYPE_DEBUG, "gcry_mpi_scan", rc);
2389 current += PAILLIER_ELEMENT_LENGTH;
2391 if (session->transferred != session->used)
2392 return GNUNET_OK; //wait for the other multipart chunks
2394 session->state = SERVICE_RESPONSE_RECEIVED;
2395 session->product = compute_scalar_product (session); //never NULL
2398 GNUNET_break_op (NULL != session->product);
2399 // send message with product to client
2400 if (ALICE == session->role){
2401 session->state = FINALIZED;
2402 session->channel = NULL;
2403 session->client_notification_task =
2404 GNUNET_SCHEDULER_add_now (&prepare_client_response,
2407 // the channel has done its job, terminate our connection and the channel
2408 // the peer will be notified that the channel was destroyed via channel_destruction_handler
2409 // just close the connection, as recommended by Christian
2410 return GNUNET_SYSERR;
2415 * Task run during shutdown.
2421 shutdown_task (void *cls,
2422 const struct GNUNET_SCHEDULER_TaskContext *tc)
2424 struct ServiceSession * session;
2425 GNUNET_log (GNUNET_ERROR_TYPE_INFO, _ ("Shutting down, initiating cleanup.\n"));
2427 do_shutdown = GNUNET_YES;
2429 // terminate all owned open channels.
2430 for (session = from_client_head; NULL != session; session = session->next) {
2431 if ((FINALIZED != session->state) && (NULL != session->channel)) {
2432 GNUNET_MESH_channel_destroy (session->channel);
2433 session->channel = NULL;
2435 if (GNUNET_SCHEDULER_NO_TASK != session->client_notification_task) {
2436 GNUNET_SCHEDULER_cancel (session->client_notification_task);
2437 session->client_notification_task = GNUNET_SCHEDULER_NO_TASK;
2439 if (GNUNET_SCHEDULER_NO_TASK != session->service_request_task) {
2440 GNUNET_SCHEDULER_cancel (session->service_request_task);
2441 session->service_request_task = GNUNET_SCHEDULER_NO_TASK;
2443 if (NULL != session->client) {
2444 GNUNET_SERVER_client_disconnect (session->client);
2445 session->client = NULL;
2448 for (session = from_service_head; NULL != session; session = session->next)
2449 if (NULL != session->channel) {
2450 GNUNET_MESH_channel_destroy (session->channel);
2451 session->channel = NULL;
2455 GNUNET_MESH_disconnect (my_mesh);
2462 * Initialization of the program and message handlers
2464 * @param cls closure
2465 * @param server the initialized server
2466 * @param c configuration to use
2470 struct GNUNET_SERVER_Handle *server,
2471 const struct GNUNET_CONFIGURATION_Handle *c)
2473 static const struct GNUNET_SERVER_MessageHandler server_handlers[] = {
2474 {&handle_client_request, NULL, GNUNET_MESSAGE_TYPE_SCALARPRODUCT_CLIENT_TO_ALICE, 0},
2475 {&handle_client_request, NULL, GNUNET_MESSAGE_TYPE_SCALARPRODUCT_CLIENT_TO_BOB, 0},
2478 static const struct GNUNET_MESH_MessageHandler mesh_handlers[] = {
2479 { &handle_service_request, GNUNET_MESSAGE_TYPE_SCALARPRODUCT_ALICE_TO_BOB, 0},
2480 { &handle_service_request_multipart, GNUNET_MESSAGE_TYPE_SCALARPRODUCT_ALICE_TO_BOB_MULTIPART, 0},
2481 { &handle_service_response, GNUNET_MESSAGE_TYPE_SCALARPRODUCT_BOB_TO_ALICE, 0},
2482 { &handle_service_response_multipart, GNUNET_MESSAGE_TYPE_SCALARPRODUCT_BOB_TO_ALICE_MULTIPART, 0},
2485 static const uint32_t ports[] = {
2486 GNUNET_APPLICATION_TYPE_SCALARPRODUCT,
2489 //generate private/public key set
2490 GNUNET_log (GNUNET_ERROR_TYPE_INFO, _ ("Generating Paillier-Keyset.\n"));
2492 // register server callbacks and disconnect handler
2493 GNUNET_SERVER_add_handlers (server, server_handlers);
2494 GNUNET_SERVER_disconnect_notify (server,
2495 &handle_client_disconnect,
2497 GNUNET_break (GNUNET_OK ==
2498 GNUNET_CRYPTO_get_peer_identity (c,
2500 my_mesh = GNUNET_MESH_connect (c, NULL,
2501 &channel_incoming_handler,
2502 &channel_destruction_handler,
2503 mesh_handlers, ports);
2505 GNUNET_log (GNUNET_ERROR_TYPE_ERROR, _ ("Connect to MESH failed\n"));
2506 GNUNET_SCHEDULER_shutdown ();
2509 GNUNET_log (GNUNET_ERROR_TYPE_INFO, _ ("Mesh initialized\n"));
2510 GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_FOREVER_REL,
2517 * The main function for the scalarproduct service.
2519 * @param argc number of arguments from the command line
2520 * @param argv command line arguments
2521 * @return 0 ok, 1 on error
2524 main (int argc, char *const *argv)
2526 return (GNUNET_OK ==
2527 GNUNET_SERVICE_run (argc, argv,
2529 GNUNET_SERVICE_OPTION_NONE,
2530 &run, NULL)) ? 0 : 1;
2533 /* end of gnunet-service-scalarproduct.c */