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 * Encrypts an element using the paillier crypto system
476 * @param c ciphertext (output)
478 * @param g the public base
479 * @param n the module from which which r is chosen (Z*_n)
480 * @param n_square the module for encryption, for performance reasons.
483 encrypt_element (gcry_mpi_t c, gcry_mpi_t m, gcry_mpi_t g, gcry_mpi_t n, gcry_mpi_t n_square)
487 GNUNET_assert (tmp = gcry_mpi_new (0));
489 while (0 >= gcry_mpi_cmp_ui (tmp, 1)) {
490 gcry_mpi_randomize (tmp, KEYBITS / 3, GCRY_WEAK_RANDOM);
491 // r must be 1 < r < n
494 gcry_mpi_powm (c, g, m, n_square);
495 gcry_mpi_powm (tmp, tmp, n, n_square);
496 gcry_mpi_mulm (c, tmp, c, n_square);
498 gcry_mpi_release (tmp);
503 * decrypts an element using the paillier crypto system
505 * @param m plaintext (output)
506 * @param c the ciphertext
507 * @param mu the modifier to correct encryption
508 * @param lambda the private exponent
509 * @param n the outer module for decryption
510 * @param n_square the inner module for decryption
513 decrypt_element (gcry_mpi_t m, gcry_mpi_t c, gcry_mpi_t mu, gcry_mpi_t lambda, gcry_mpi_t n, gcry_mpi_t n_square)
515 gcry_mpi_powm (m, c, lambda, n_square);
516 gcry_mpi_sub_ui (m, m, 1);
517 gcry_mpi_div (m, NULL, m, n, 0);
518 gcry_mpi_mulm (m, m, mu, n);
523 * computes the square sum over a vector of a given length.
525 * @param vector the vector to encrypt
526 * @param length the length of the vector
527 * @return an MPI value containing the calculated sum, never NULL
530 compute_square_sum (gcry_mpi_t * vector, uint32_t length)
536 GNUNET_assert (sum = gcry_mpi_new (0));
537 GNUNET_assert (elem = gcry_mpi_new (0));
539 // calculare E(sum (ai ^ 2), publickey)
540 for (i = 0; i < length; i++) {
541 gcry_mpi_mul (elem, vector[i], vector[i]);
542 gcry_mpi_add (sum, sum, elem);
544 gcry_mpi_release (elem);
551 * Primitive callback for copying over a message, as they
552 * usually are too complex to be handled in the callback itself.
553 * clears a session-callback, if a session was handed over and the transmit handle was stored
555 * @param cls the message object
556 * @param size the size of the buffer we got
557 * @param buf the buffer to copy the message to
558 * @return 0 if we couldn't copy, else the size copied over
561 do_send_message (void *cls, size_t size, void *buf)
563 struct ServiceSession * session = cls;
568 if (ntohs (session->msg->size) != size) {
573 type = ntohs (session->msg->type);
574 memcpy (buf, session->msg, size);
575 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
576 "Sent a message of type %hu.\n",
578 GNUNET_free (session->msg);
583 case GNUNET_MESSAGE_TYPE_SCALARPRODUCT_SERVICE_TO_CLIENT:
584 session->state = FINALIZED;
585 session->client_transmit_handle = NULL;
588 case GNUNET_MESSAGE_TYPE_SCALARPRODUCT_ALICE_TO_BOB:
589 case GNUNET_MESSAGE_TYPE_SCALARPRODUCT_ALICE_TO_BOB_MULTIPART:
590 session->service_transmit_handle = NULL;
591 if (session->state == WAITING_FOR_MULTIPART_TRANSMISSION)
592 prepare_service_request_multipart (session);
595 case GNUNET_MESSAGE_TYPE_SCALARPRODUCT_BOB_TO_ALICE:
596 case GNUNET_MESSAGE_TYPE_SCALARPRODUCT_BOB_TO_ALICE_MULTIPART:
597 session->service_transmit_handle = NULL;
598 if (session->state == WAITING_FOR_MULTIPART_TRANSMISSION)
599 prepare_service_response_multipart (session);
611 * initializes a new vector with fresh MPI values (=0) of a given length
613 * @param length of the vector to create
614 * @return the initialized vector, never NULL
617 initialize_mpi_vector (uint32_t length)
620 gcry_mpi_t * output = GNUNET_malloc (sizeof (gcry_mpi_t) * length);
622 for (i = 0; i < length; i++)
623 GNUNET_assert (NULL != (output[i] = gcry_mpi_new (0)));
629 * permutes an MPI vector according to the given permutation vector
631 * @param vector the vector to permuted
632 * @param perm the permutation to use
633 * @param length the length of the vectors
634 * @return the permuted vector (same as input), never NULL
637 permute_vector (gcry_mpi_t * vector,
641 gcry_mpi_t tmp[length];
644 GNUNET_assert (length > 0);
647 memcpy (tmp, vector, length * sizeof (gcry_mpi_t));
649 // permute vector according to given
650 for (i = 0; i < length; i++)
651 vector[i] = tmp[perm[i]];
658 * Finds a not terminated client/service session in the
659 * given DLL based on session key, element count and state.
661 * @param tail - the tail of the DLL
662 * @param key - the key we want to search for
663 * @param element_count - the total element count of the dataset (session->total)
664 * @param state - a pointer to the state the session should be in, NULL to ignore
665 * @param peerid - a pointer to the peer ID of the associated peer, NULL to ignore
666 * @return a pointer to a matching session, or NULL
668 static struct ServiceSession *
669 find_matching_session (struct ServiceSession * tail,
670 const struct GNUNET_HashCode * key,
671 uint32_t element_count,
672 enum SessionState * state,
673 const struct GNUNET_PeerIdentity * peerid)
675 struct ServiceSession * curr;
677 for (curr = tail; NULL != curr; curr = curr->prev) {
678 // if the key matches, and the element_count is same
679 if ((!memcmp (&curr->key, key, sizeof (struct GNUNET_HashCode)))
680 && (curr->total == element_count)) {
681 // if incoming state is NULL OR is same as state of the queued request
682 if ((NULL == state) || (curr->state == *state)) {
683 // if peerid is NULL OR same as the peer Id in the queued request
685 || (!memcmp (&curr->peer, peerid, sizeof (struct GNUNET_PeerIdentity))))
686 // matches and is not an already terminated session
696 * Safely frees ALL memory areas referenced by a session.
698 * @param session - the session to free elements from
701 free_session_variables (struct ServiceSession * session)
706 for (i = 0; i < session->used; i++)
707 if (session->a[i]) gcry_mpi_release (session->a[i]);
708 GNUNET_free (session->a);
712 GNUNET_free (session->mask);
713 session->mask = NULL;
716 for (i = 0; i < session->used; i++)
717 if (session->r[i]) gcry_mpi_release (session->r[i]);
718 GNUNET_free (session->r);
721 if (session->r_prime) {
722 for (i = 0; i < session->used; i++)
723 if (session->r_prime[i]) gcry_mpi_release (session->r_prime[i]);
724 GNUNET_free (session->r_prime);
725 session->r_prime = NULL;
728 gcry_mpi_release (session->s);
732 if (session->s_prime) {
733 gcry_mpi_release (session->s_prime);
734 session->s_prime = NULL;
737 if (session->product) {
738 gcry_mpi_release (session->product);
739 session->product = NULL;
742 if (session->remote_pubkey) {
743 gcry_sexp_release (session->remote_pubkey);
744 session->remote_pubkey = NULL;
747 if (session->vector) {
748 GNUNET_free_non_null (session->vector);
752 ///////////////////////////////////////////////////////////////////////////////
753 // Event and Message Handlers
754 ///////////////////////////////////////////////////////////////////////////////
758 * A client disconnected.
760 * Remove the associated session(s), release data structures
761 * and cancel pending outgoing transmissions to the client.
762 * if the session has not yet completed, we also cancel Alice's request to Bob.
764 * @param cls closure, NULL
765 * @param client identification of the client
768 handle_client_disconnect (void *cls,
769 struct GNUNET_SERVER_Client *client)
771 struct ServiceSession *session;
774 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
775 _ ("Client (%p) disconnected from us.\n"), client);
779 session = GNUNET_SERVER_client_get_user_context (client, struct ServiceSession);
782 GNUNET_CONTAINER_DLL_remove (from_client_head, from_client_tail, session);
784 if (!(session->role == BOB && session->state == FINALIZED)) {
785 //we MUST terminate any client message underway
786 if (session->service_transmit_handle && session->channel)
787 GNUNET_MESH_notify_transmit_ready_cancel (session->service_transmit_handle);
788 if (session->channel && session->state == WAITING_FOR_SERVICE_RESPONSE)
789 GNUNET_MESH_channel_destroy (session->channel);
791 if (GNUNET_SCHEDULER_NO_TASK != session->client_notification_task) {
792 GNUNET_SCHEDULER_cancel (session->client_notification_task);
793 session->client_notification_task = GNUNET_SCHEDULER_NO_TASK;
795 if (GNUNET_SCHEDULER_NO_TASK != session->service_request_task) {
796 GNUNET_SCHEDULER_cancel (session->service_request_task);
797 session->service_request_task = GNUNET_SCHEDULER_NO_TASK;
799 if (NULL != session->client_transmit_handle) {
800 GNUNET_SERVER_notify_transmit_ready_cancel (session->client_transmit_handle);
801 session->client_transmit_handle = NULL;
803 free_session_variables (session);
804 GNUNET_free (session);
809 * Notify the client that the session has succeeded or failed completely.
810 * This message gets sent to
811 * * alice's client if bob disconnected or to
812 * * bob's client if the operation completed or alice disconnected
814 * @param cls the associated client session
815 * @param tc the task context handed to us by the scheduler, unused
818 prepare_client_end_notification (void * cls,
819 const struct GNUNET_SCHEDULER_TaskContext * tc)
821 struct ServiceSession * session = cls;
822 struct GNUNET_SCALARPRODUCT_client_response * msg;
824 session->client_notification_task = GNUNET_SCHEDULER_NO_TASK;
826 msg = GNUNET_new (struct GNUNET_SCALARPRODUCT_client_response);
827 msg->header.type = htons (GNUNET_MESSAGE_TYPE_SCALARPRODUCT_SERVICE_TO_CLIENT);
828 memcpy (&msg->key, &session->key, sizeof (struct GNUNET_HashCode));
829 memcpy (&msg->peer, &session->peer, sizeof ( struct GNUNET_PeerIdentity));
830 msg->header.size = htons (sizeof (struct GNUNET_SCALARPRODUCT_client_response));
831 // signal error if not signalized, positive result-range field but zero length.
832 msg->product_length = htonl (0);
833 msg->range = (session->state == FINALIZED) ? 0 : -1;
835 session->msg = &msg->header;
837 //transmit this message to our client
838 session->client_transmit_handle =
839 GNUNET_SERVER_notify_transmit_ready (session->client,
840 sizeof (struct GNUNET_SCALARPRODUCT_client_response),
841 GNUNET_TIME_UNIT_FOREVER_REL,
845 // if we could not even queue our request, something is wrong
846 if (NULL == session->client_transmit_handle) {
847 GNUNET_log (GNUNET_ERROR_TYPE_WARNING, _ ("Could not send message to client (%p)!\n"), session->client);
848 // usually gets freed by do_send_message
853 GNUNET_log (GNUNET_ERROR_TYPE_INFO, _ ("Sending session-end notification to client (%p) for session %s\n"), &session->client, GNUNET_h2s (&session->key));
855 free_session_variables (session);
860 * prepare the response we will send to alice or bobs' clients.
861 * in Bobs case the product will be NULL.
863 * @param cls the session associated with our client.
864 * @param tc the task context handed to us by the scheduler, unused
867 prepare_client_response (void *cls,
868 const struct GNUNET_SCHEDULER_TaskContext *tc)
870 struct ServiceSession * session = cls;
871 struct GNUNET_SCALARPRODUCT_client_response * msg;
872 unsigned char * product_exported = NULL;
873 size_t product_length = 0;
874 uint32_t msg_length = 0;
879 session->client_notification_task = GNUNET_SCHEDULER_NO_TASK;
881 if (session->product) {
882 gcry_mpi_t value = gcry_mpi_new (0);
884 sign = gcry_mpi_cmp_ui (session->product, 0);
885 // libgcrypt can not handle a print of a negative number
886 // if (a->sign) return gcry_error (GPG_ERR_INTERNAL); /* Can't handle it yet. */
888 gcry_mpi_sub (value, value, session->product);
892 gcry_mpi_add (value, value, session->product);
897 gcry_mpi_release (session->product);
898 session->product = NULL;
900 // get representation as string
902 && (0 != (rc = gcry_mpi_aprint (GCRYMPI_FMT_STD,
906 LOG_GCRY (GNUNET_ERROR_TYPE_ERROR, "gcry_mpi_scan", rc);
908 range = -1; // signal error with product-length = 0 and range = -1
910 gcry_mpi_release (value);
913 msg_length = sizeof (struct GNUNET_SCALARPRODUCT_client_response) +product_length;
914 msg = GNUNET_malloc (msg_length);
915 msg->key = session->key;
916 msg->peer = session->peer;
917 if (product_exported != NULL)
919 memcpy (&msg[1], product_exported, product_length);
920 GNUNET_free (product_exported);
922 msg->header.type = htons (GNUNET_MESSAGE_TYPE_SCALARPRODUCT_SERVICE_TO_CLIENT);
923 msg->header.size = htons (msg_length);
925 msg->product_length = htonl (product_length);
927 session->msg = (struct GNUNET_MessageHeader *) msg;
928 //transmit this message to our client
929 session->client_transmit_handle =
930 GNUNET_SERVER_notify_transmit_ready (session->client,
932 GNUNET_TIME_UNIT_FOREVER_REL,
935 if (NULL == session->client_transmit_handle) {
936 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
937 _ ("Could not send message to client (%p)!\n"),
939 session->client = NULL;
940 // callback was not called!
945 // gracefully sent message, just terminate session structure
946 GNUNET_log (GNUNET_ERROR_TYPE_INFO,
947 _ ("Sent result to client (%p), this session (%s) has ended!\n"),
949 GNUNET_h2s (&session->key));
950 free_session_variables (session);
955 * Send a multipart chunk of a service response from bob to alice.
956 * This element only contains the two permutations of R, R'.
958 * @param cls the associated service session
961 prepare_service_response_multipart (void *cls)
963 struct ServiceSession * session = cls;
964 unsigned char * current;
965 unsigned char * element_exported;
966 struct GNUNET_SCALARPRODUCT_multipart_message * msg;
970 size_t element_length = 0; // initialized by gcry_mpi_print, but the compiler doesn't know that
972 msg_length = sizeof (struct GNUNET_SCALARPRODUCT_multipart_message);
973 todo_count = session->used - session->transferred;
975 if (todo_count > MULTIPART_ELEMENT_CAPACITY / 2)
976 // send the currently possible maximum chunk, we always transfer both permutations
977 todo_count = MULTIPART_ELEMENT_CAPACITY / 2;
979 msg_length += todo_count * PAILLIER_ELEMENT_LENGTH * 2;
980 msg = GNUNET_malloc (msg_length);
981 msg->header.type = htons (GNUNET_MESSAGE_TYPE_SCALARPRODUCT_ALICE_TO_BOB_MULTIPART);
982 msg->header.size = htons (msg_length);
983 msg->multipart_element_count = htonl (todo_count);
985 element_exported = GNUNET_malloc (PAILLIER_ELEMENT_LENGTH);
986 current = (unsigned char *) &msg[1];
988 for (i = session->transferred; i < session->transferred + todo_count; i++) {
990 memset (element_exported, 0, PAILLIER_ELEMENT_LENGTH);
991 GNUNET_assert (0 == gcry_mpi_print (GCRYMPI_FMT_USG,
992 element_exported, PAILLIER_ELEMENT_LENGTH,
995 adjust (element_exported, element_length, PAILLIER_ELEMENT_LENGTH);
996 memcpy (current, element_exported, PAILLIER_ELEMENT_LENGTH);
997 current += PAILLIER_ELEMENT_LENGTH;
999 memset (element_exported, 0, PAILLIER_ELEMENT_LENGTH);
1000 GNUNET_assert (0 == gcry_mpi_print (GCRYMPI_FMT_USG,
1001 element_exported, PAILLIER_ELEMENT_LENGTH,
1003 session->r_prime[i]));
1004 adjust (element_exported, element_length, PAILLIER_ELEMENT_LENGTH);
1005 memcpy (current, element_exported, PAILLIER_ELEMENT_LENGTH);
1006 current += PAILLIER_ELEMENT_LENGTH;
1008 GNUNET_free (element_exported);
1009 for (i = session->transferred; i < session->transferred; i++) {
1010 gcry_mpi_release (session->r_prime[i]);
1011 session->r_prime[i] = NULL;
1012 gcry_mpi_release (session->r[i]);
1013 session->r[i] = NULL;
1015 session->transferred += todo_count;
1016 session->msg = (struct GNUNET_MessageHeader *) msg;
1017 session->service_transmit_handle =
1018 GNUNET_MESH_notify_transmit_ready (session->channel,
1020 GNUNET_TIME_UNIT_FOREVER_REL,
1024 //disconnect our client
1025 if (NULL == session->service_transmit_handle) {
1026 GNUNET_log (GNUNET_ERROR_TYPE_ERROR, _ ("Could not send service-response message via mesh!)\n"));
1027 session->state = FINALIZED;
1029 session->response->client_notification_task =
1030 GNUNET_SCHEDULER_add_now (&prepare_client_end_notification,
1034 if (session->transferred != session->used)
1036 session->state = WAITING_FOR_MULTIPART_TRANSMISSION;
1039 session->state = FINALIZED;
1040 GNUNET_free(session->r);
1041 GNUNET_free(session->r_prime);
1042 session->r_prime = NULL;
1050 * generates the response message to be sent to alice after computing
1051 * the values (1), (2), S and S'
1052 * (1)[]: $E_A(a_{pi(i)}) times E_A(- r_{pi(i)} - b_{pi(i)}) &= E_A(a_{pi(i)} - r_{pi(i)} - b_{pi(i)})$
1053 * (2)[]: $E_A(a_{pi'(i)}) times E_A(- r_{pi'(i)}) &= E_A(a_{pi'(i)} - r_{pi'(i)})$
1054 * S: $S := E_A(sum (r_i + b_i)^2)$
1055 * S': $S' := E_A(sum r_i^2)$
1057 * @param s S: $S := E_A(sum (r_i + b_i)^2)$
1058 * @param s_prime S': $S' := E_A(sum r_i^2)$
1059 * @param session the associated requesting session with alice
1060 * @return #GNUNET_NO if we could not send our message
1061 * #GNUNET_OK if the operation succeeded
1064 prepare_service_response (gcry_mpi_t s,
1066 struct ServiceSession * session)
1068 struct GNUNET_SCALARPRODUCT_service_response * msg;
1069 uint32_t msg_length = 0;
1070 unsigned char * current = NULL;
1071 unsigned char * element_exported = NULL;
1072 size_t element_length = 0;
1075 msg_length = sizeof (struct GNUNET_SCALARPRODUCT_service_response)
1076 + 2 * PAILLIER_ELEMENT_LENGTH; // s, stick
1078 if (GNUNET_SERVER_MAX_MESSAGE_SIZE > msg_length + 2 * session->used * PAILLIER_ELEMENT_LENGTH) { //kp, kq
1079 msg_length += +2 * session->used * PAILLIER_ELEMENT_LENGTH;
1080 session->transferred = session->used;
1083 session->transferred = (GNUNET_SERVER_MAX_MESSAGE_SIZE - 1 - msg_length) / (PAILLIER_ELEMENT_LENGTH * 2);
1086 msg = GNUNET_malloc (msg_length);
1088 msg->header.type = htons (GNUNET_MESSAGE_TYPE_SCALARPRODUCT_BOB_TO_ALICE);
1089 msg->header.size = htons (msg_length);
1090 msg->total_element_count = htonl (session->total);
1091 msg->used_element_count = htonl (session->used);
1092 msg->contained_element_count = htonl (session->transferred);
1093 memcpy (&msg->key, &session->key, sizeof (struct GNUNET_HashCode));
1094 current = (unsigned char *) &msg[1];
1096 element_exported = GNUNET_malloc (PAILLIER_ELEMENT_LENGTH);
1097 // 4 times the same logics with slight variations.
1098 // doesn't really justify having 2 functions for that
1099 // so i put it into blocks to enhance readability
1101 memset (element_exported, 0, PAILLIER_ELEMENT_LENGTH);
1102 GNUNET_assert (0 == gcry_mpi_print (GCRYMPI_FMT_USG,
1103 element_exported, PAILLIER_ELEMENT_LENGTH,
1106 adjust (element_exported, element_length, PAILLIER_ELEMENT_LENGTH);
1107 memcpy (current, element_exported, PAILLIER_ELEMENT_LENGTH);
1108 current += PAILLIER_ELEMENT_LENGTH;
1111 memset (element_exported, 0, PAILLIER_ELEMENT_LENGTH);
1112 GNUNET_assert (0 == gcry_mpi_print (GCRYMPI_FMT_USG,
1113 element_exported, PAILLIER_ELEMENT_LENGTH,
1116 adjust (element_exported, element_length, PAILLIER_ELEMENT_LENGTH);
1117 memcpy (current, element_exported, PAILLIER_ELEMENT_LENGTH);
1118 current += PAILLIER_ELEMENT_LENGTH;
1121 for (i = 0; i < session->transferred; i++) {
1123 memset (element_exported, 0, PAILLIER_ELEMENT_LENGTH);
1124 GNUNET_assert (0 == gcry_mpi_print (GCRYMPI_FMT_USG,
1125 element_exported, PAILLIER_ELEMENT_LENGTH,
1128 adjust (element_exported, element_length, PAILLIER_ELEMENT_LENGTH);
1129 memcpy (current, element_exported, PAILLIER_ELEMENT_LENGTH);
1130 current += PAILLIER_ELEMENT_LENGTH;
1132 memset (element_exported, 0, PAILLIER_ELEMENT_LENGTH);
1133 GNUNET_assert (0 == gcry_mpi_print (GCRYMPI_FMT_USG,
1134 element_exported, PAILLIER_ELEMENT_LENGTH,
1136 session->r_prime[i]));
1137 adjust (element_exported, element_length, PAILLIER_ELEMENT_LENGTH);
1138 memcpy (current, element_exported, PAILLIER_ELEMENT_LENGTH);
1139 current += PAILLIER_ELEMENT_LENGTH;
1142 GNUNET_free (element_exported);
1143 for (i = 0; i < session->transferred; i++) {
1144 gcry_mpi_release (session->r_prime[i]);
1145 session->r_prime[i] = NULL;
1146 gcry_mpi_release (session->r[i]);
1147 session->r[i] = NULL;
1149 gcry_mpi_release (s);
1151 gcry_mpi_release (s_prime);
1152 session->s_prime = NULL;
1154 session->msg = (struct GNUNET_MessageHeader *) msg;
1155 session->service_transmit_handle =
1156 GNUNET_MESH_notify_transmit_ready (session->channel,
1158 GNUNET_TIME_UNIT_FOREVER_REL,
1162 //disconnect our client
1163 if (NULL == session->service_transmit_handle) {
1164 GNUNET_log (GNUNET_ERROR_TYPE_ERROR, _ ("Could not send service-response message via mesh!)\n"));
1165 session->state = FINALIZED;
1167 session->response->client_notification_task =
1168 GNUNET_SCHEDULER_add_now (&prepare_client_end_notification,
1172 if (session->transferred != session->used)
1174 session->state = WAITING_FOR_MULTIPART_TRANSMISSION;
1177 session->state = FINALIZED;
1178 GNUNET_free(session->r);
1179 GNUNET_free(session->r_prime);
1180 session->r_prime = NULL;
1190 * compute the values
1191 * (1)[]: $E_A(a_{pi(i)}) otimes E_A(- r_{pi(i)} - b_{pi(i)}) &= E_A(a_{pi(i)} - r_{pi(i)} - b_{pi(i)})$
1192 * (2)[]: $E_A(a_{pi'(i)}) otimes E_A(- r_{pi'(i)}) &= E_A(a_{pi'(i)} - r_{pi'(i)})$
1193 * S: $S := E_A(sum (r_i + b_i)^2)$
1194 * S': $S' := E_A(sum r_i^2)$
1196 * @param request the requesting session + bob's requesting peer
1197 * @param response the responding session + bob's client handle
1198 * @return GNUNET_SYSERR if the computation failed
1199 * GNUNET_OK if everything went well.
1202 compute_service_response (struct ServiceSession * request,
1203 struct ServiceSession * response)
1207 int ret = GNUNET_SYSERR;
1211 gcry_mpi_t * rand = NULL;
1212 gcry_mpi_t * r = NULL;
1213 gcry_mpi_t * r_prime = NULL;
1216 gcry_mpi_t * a_pi_prime;
1218 gcry_mpi_t * rand_pi;
1219 gcry_mpi_t * rand_pi_prime;
1220 gcry_mpi_t s = NULL;
1221 gcry_mpi_t s_prime = NULL;
1222 gcry_mpi_t remote_n = NULL;
1223 gcry_mpi_t remote_nsquare;
1224 gcry_mpi_t remote_g = NULL;
1225 gcry_sexp_t tmp_exp;
1228 count = request->used;
1230 b = GNUNET_malloc (sizeof (gcry_mpi_t) * count);
1231 a_pi = GNUNET_malloc (sizeof (gcry_mpi_t) * count);
1232 b_pi = GNUNET_malloc (sizeof (gcry_mpi_t) * count);
1233 a_pi_prime = GNUNET_malloc (sizeof (gcry_mpi_t) * count);
1234 rand_pi = GNUNET_malloc (sizeof (gcry_mpi_t) * count);
1235 rand_pi_prime = GNUNET_malloc (sizeof (gcry_mpi_t) * count);
1237 // convert responder session to from long to mpi
1238 for (i = 0, j = 0; i < response->total && j < count; i++) {
1239 if (request->mask[i / 8] & (1 << (i % 8))) {
1240 value = response->vector[i] >= 0 ? response->vector[i] : -response->vector[i];
1241 // long to gcry_mpi_t
1242 if (0 > response->vector[i]) {
1243 b[j] = gcry_mpi_new (0);
1244 gcry_mpi_sub_ui (b[j], b[j], value);
1247 b[j] = gcry_mpi_set_ui (NULL, value);
1252 GNUNET_free (response->vector);
1253 response->vector = NULL;
1255 tmp_exp = gcry_sexp_find_token (request->remote_pubkey, "n", 0);
1257 GNUNET_break_op (0);
1258 gcry_sexp_release (request->remote_pubkey);
1259 request->remote_pubkey = NULL;
1262 remote_n = gcry_sexp_nth_mpi (tmp_exp, 1, GCRYMPI_FMT_USG);
1265 gcry_sexp_release (tmp_exp);
1268 remote_nsquare = gcry_mpi_new (KEYBITS + 1);
1269 gcry_mpi_mul (remote_nsquare, remote_n, remote_n);
1270 gcry_sexp_release (tmp_exp);
1271 tmp_exp = gcry_sexp_find_token (request->remote_pubkey, "g", 0);
1272 gcry_sexp_release (request->remote_pubkey);
1273 request->remote_pubkey = NULL;
1275 GNUNET_break_op (0);
1276 gcry_mpi_release (remote_n);
1279 remote_g = gcry_sexp_nth_mpi (tmp_exp, 1, GCRYMPI_FMT_USG);
1282 gcry_mpi_release (remote_n);
1283 gcry_sexp_release (tmp_exp);
1286 gcry_sexp_release (tmp_exp);
1288 // generate r, p and q
1289 rand = initialize_mpi_vector (count);
1290 for (i = 0; i < count; i++)
1294 svalue = (int32_t) GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK, UINT32_MAX);
1296 // long to gcry_mpi_t
1298 gcry_mpi_sub_ui (rand[i],
1302 rand[i] = gcry_mpi_set_ui (rand[i], svalue);
1304 p = GNUNET_CRYPTO_random_permute (GNUNET_CRYPTO_QUALITY_WEAK, count);
1305 q = GNUNET_CRYPTO_random_permute (GNUNET_CRYPTO_QUALITY_WEAK, count);
1306 //initialize the result vectors
1307 r = initialize_mpi_vector (count);
1308 r_prime = initialize_mpi_vector (count);
1310 // copy the REFERNCES of a, b and r into aq and bq. we will not change
1311 // those values, thus we can work with the references
1312 memcpy (a_pi, request->a, sizeof (gcry_mpi_t) * count);
1313 memcpy (a_pi_prime, request->a, sizeof (gcry_mpi_t) * count);
1314 memcpy (b_pi, b, sizeof (gcry_mpi_t) * count);
1315 memcpy (rand_pi, rand, sizeof (gcry_mpi_t) * count);
1316 memcpy (rand_pi_prime, rand, sizeof (gcry_mpi_t) * count);
1318 // generate p and q permutations for a, b and r
1319 GNUNET_assert (permute_vector (a_pi, p, count));
1320 GNUNET_assert (permute_vector (b_pi, p, count));
1321 GNUNET_assert (permute_vector (rand_pi, p, count));
1322 GNUNET_assert (permute_vector (a_pi_prime, q, count));
1323 GNUNET_assert (permute_vector (rand_pi_prime, q, count));
1325 // encrypt the element
1326 // for the sake of readability I decided to have dedicated permutation
1327 // vectors, which get rid of all the lookups in p/q.
1328 // however, ap/aq are not absolutely necessary but are just abstraction
1329 // Calculate Kp = E(S + a_pi) (+) E(S - r_pi - b_pi)
1330 for (i = 0; i < count; i++) {
1331 // E(S - r_pi - b_pi)
1332 gcry_mpi_sub (r[i], my_offset, rand_pi[i]);
1333 gcry_mpi_sub (r[i], r[i], b_pi[i]);
1334 encrypt_element (r[i], r[i], remote_g, remote_n, remote_nsquare);
1336 // E(S - r_pi - b_pi) * E(S + a_pi) == E(2*S + a - r - b)
1337 gcry_mpi_mulm (r[i], r[i], a_pi[i], remote_nsquare);
1341 GNUNET_free (rand_pi);
1343 // Calculate Kq = E(S + a_qi) (+) E(S - r_qi)
1344 for (i = 0; i < count; i++)
1347 gcry_mpi_sub (r_prime[i], my_offset, rand_pi_prime[i]);
1348 encrypt_element (r_prime[i], r_prime[i], remote_g, remote_n, remote_nsquare);
1350 // E(S - r_qi) * E(S + a_qi) == E(2*S + a_qi - r_qi)
1351 gcry_mpi_mulm (r_prime[i], r_prime[i], a_pi_prime[i], remote_nsquare);
1353 GNUNET_free (a_pi_prime);
1354 GNUNET_free (rand_pi_prime);
1357 request->r_prime = r_prime;
1358 request->response = response;
1360 // Calculate S' = E(SUM( r_i^2 ))
1361 s_prime = compute_square_sum (rand, count);
1362 encrypt_element (s_prime, s_prime, remote_g, remote_n, remote_nsquare);
1364 // Calculate S = E(SUM( (r_i + b_i)^2 ))
1365 for (i = 0; i < count; i++) {
1366 gcry_mpi_add (rand[i], rand[i], b[i]);
1368 s = compute_square_sum (rand, count);
1369 encrypt_element (s, s, remote_g, remote_n, remote_nsquare);
1370 gcry_mpi_release (remote_n);
1371 gcry_mpi_release (remote_g);
1372 gcry_mpi_release (remote_nsquare);
1374 // release r and tmp
1375 for (i = 0; i < count; i++)
1376 // rp, rq, aq, ap, bp, bq are released along with a, r, b respectively, (a and b are handled at except:)
1377 gcry_mpi_release (rand[i]);
1379 // copy the r[], r_prime[], S and Stick into a new message, prepare_service_response frees these
1380 if (GNUNET_YES != prepare_service_response (s, s_prime, request))
1381 GNUNET_log (GNUNET_ERROR_TYPE_INFO, _ ("Failed to communicate with `%s', scalar product calculation aborted.\n"),
1382 GNUNET_i2s (&request->peer));
1387 for (i = 0; i < count; i++)
1389 gcry_mpi_release (b[i]);
1390 gcry_mpi_release (request->a[i]);
1391 gcry_mpi_release (rand[i]);
1392 gcry_mpi_release (r[i]);
1393 gcry_mpi_release (r_prime[i]);
1397 GNUNET_free (request->a);
1403 GNUNET_free (rand_pi);
1405 GNUNET_free (r_prime);
1411 * Send a multi part chunk of a service request from alice to bob.
1412 * This element only contains a part of the elements-vector (session->a[]),
1413 * mask and public key set have to be contained within the first message
1415 * This allows a ~32kbit key length while using 32000 elements or 62000 elements per request.
1417 * @param cls the associated service session
1420 prepare_service_request_multipart (void *cls)
1422 struct ServiceSession * session = cls;
1423 unsigned char * current;
1424 unsigned char * element_exported;
1425 struct GNUNET_SCALARPRODUCT_multipart_message * msg;
1428 uint32_t msg_length;
1429 uint32_t todo_count;
1430 size_t element_length = 0; // initialized by gcry_mpi_print, but the compiler doesn't know that
1434 msg_length = sizeof (struct GNUNET_SCALARPRODUCT_multipart_message);
1435 todo_count = session->used - session->transferred;
1437 if (todo_count > MULTIPART_ELEMENT_CAPACITY)
1438 // send the currently possible maximum chunk
1439 todo_count = MULTIPART_ELEMENT_CAPACITY;
1441 msg_length += todo_count * PAILLIER_ELEMENT_LENGTH;
1442 msg = GNUNET_malloc (msg_length);
1443 msg->header.type = htons (GNUNET_MESSAGE_TYPE_SCALARPRODUCT_ALICE_TO_BOB_MULTIPART);
1444 msg->header.size = htons (msg_length);
1445 msg->multipart_element_count = htonl (todo_count);
1447 element_exported = GNUNET_malloc (PAILLIER_ELEMENT_LENGTH);
1448 a = gcry_mpi_new (KEYBITS * 2);
1449 current = (unsigned char *) &msg[1];
1450 // encrypt our vector and generate string representations
1451 for (i = session->last_processed, j = 0; i < session->total; i++)
1453 // is this a used element?
1454 if (session->mask[i / 8] & 1 << (i % 8)) {
1455 if (todo_count <= j)
1456 break; //reached end of this message, can't include more
1458 memset (element_exported, 0, PAILLIER_ELEMENT_LENGTH);
1459 value = session->vector[i] >= 0 ? session->vector[i] : -session->vector[i];
1461 a = gcry_mpi_set_ui (a, 0);
1462 // long to gcry_mpi_t
1463 if (session->vector[i] < 0)
1464 gcry_mpi_sub_ui (a, a, value);
1466 gcry_mpi_add_ui (a, a, value);
1468 session->a[session->transferred + j++] = gcry_mpi_set (NULL, a);
1469 gcry_mpi_add (a, a, my_offset);
1470 encrypt_element (a, a, my_g, my_n, my_nsquare);
1472 // get representation as string
1473 // we always supply some value, so gcry_mpi_print fails only if it can't reserve memory
1474 GNUNET_assert (!gcry_mpi_print (GCRYMPI_FMT_USG,
1475 element_exported, PAILLIER_ELEMENT_LENGTH,
1479 // move buffer content to the end of the buffer so it can easily be read by libgcrypt. also this now has fixed size
1480 adjust (element_exported, element_length, PAILLIER_ELEMENT_LENGTH);
1482 // copy over to the message
1483 memcpy (current, element_exported, PAILLIER_ELEMENT_LENGTH);
1484 current += PAILLIER_ELEMENT_LENGTH;
1487 gcry_mpi_release (a);
1488 GNUNET_free (element_exported);
1489 session->transferred += todo_count;
1491 session->msg = (struct GNUNET_MessageHeader *) msg;
1492 GNUNET_log (GNUNET_ERROR_TYPE_INFO, _ ("Transmitting service request.\n"));
1494 //transmit via mesh messaging
1495 session->service_transmit_handle = GNUNET_MESH_notify_transmit_ready (session->channel, GNUNET_YES,
1496 GNUNET_TIME_UNIT_FOREVER_REL,
1500 if (!session->service_transmit_handle) {
1501 GNUNET_log (GNUNET_ERROR_TYPE_ERROR, _ ("Could not send service-request multipart message to channel!\n"));
1503 session->msg = NULL;
1504 session->client_notification_task =
1505 GNUNET_SCHEDULER_add_now (&prepare_client_end_notification,
1509 if (session->transferred != session->used) {
1510 session->last_processed = i;
1514 session->state = WAITING_FOR_SERVICE_RESPONSE;
1519 * Executed by Alice, fills in a service-request message and sends it to the given peer
1521 * @param cls the session associated with this request
1522 * @param tc task context handed over by scheduler, unsued
1525 prepare_service_request (void *cls,
1526 const struct GNUNET_SCHEDULER_TaskContext *tc)
1528 struct ServiceSession * session = cls;
1529 unsigned char * current;
1530 unsigned char * element_exported;
1531 struct GNUNET_SCALARPRODUCT_service_request * msg;
1534 uint32_t msg_length;
1535 size_t element_length = 0; // initialized by gcry_mpi_print, but the compiler doesn't know that
1539 session->service_request_task = GNUNET_SCHEDULER_NO_TASK;
1541 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, _ ("Successfully created new channel to peer (%s)!\n"), GNUNET_i2s (&session->peer));
1543 msg_length = sizeof (struct GNUNET_SCALARPRODUCT_service_request)
1544 +session->mask_length
1545 + my_pubkey_external_length;
1547 if (GNUNET_SERVER_MAX_MESSAGE_SIZE > msg_length + session->used * PAILLIER_ELEMENT_LENGTH) {
1548 msg_length += session->used * PAILLIER_ELEMENT_LENGTH;
1549 session->transferred = session->used;
1552 //create a multipart msg, first we calculate a new msg size for the head msg
1553 session->transferred = (GNUNET_SERVER_MAX_MESSAGE_SIZE - 1 - msg_length) / PAILLIER_ELEMENT_LENGTH;
1556 msg = GNUNET_malloc (msg_length);
1557 msg->header.type = htons (GNUNET_MESSAGE_TYPE_SCALARPRODUCT_ALICE_TO_BOB);
1558 msg->total_element_count = htonl (session->used);
1559 msg->contained_element_count = htonl (session->transferred);
1560 memcpy (&msg->key, &session->key, sizeof (struct GNUNET_HashCode));
1561 msg->mask_length = htonl (session->mask_length);
1562 msg->pk_length = htonl (my_pubkey_external_length);
1563 msg->element_count = htonl (session->total);
1564 msg->header.size = htons (msg_length);
1566 // fill in the payload
1567 current = (unsigned char *) &msg[1];
1568 // copy over the mask
1569 memcpy (current, session->mask, session->mask_length);
1570 // copy over our public key
1571 current += session->mask_length;
1572 memcpy (current, my_pubkey_external, my_pubkey_external_length);
1573 current += my_pubkey_external_length;
1575 // now copy over the element vector
1576 element_exported = GNUNET_malloc (PAILLIER_ELEMENT_LENGTH);
1577 session->a = GNUNET_malloc (sizeof (gcry_mpi_t) * session->used);
1578 a = gcry_mpi_new (KEYBITS * 2);
1579 // encrypt our vector and generate string representations
1580 for (i = 0, j = 0; i < session->total; i++) {
1581 // if this is a used element...
1582 if (session->mask[i / 8] & 1 << (i % 8)) {
1583 if (session->transferred <= j)
1584 break; //reached end of this message, can't include more
1586 memset (element_exported, 0, PAILLIER_ELEMENT_LENGTH);
1587 value = session->vector[i] >= 0 ? session->vector[i] : -session->vector[i];
1589 a = gcry_mpi_set_ui (a, 0);
1590 // long to gcry_mpi_t
1591 if (session->vector[i] < 0)
1592 gcry_mpi_sub_ui (a, a, value);
1594 gcry_mpi_add_ui (a, a, value);
1596 session->a[j++] = gcry_mpi_set (NULL, a);
1597 gcry_mpi_add (a, a, my_offset);
1598 encrypt_element (a, a, my_g, my_n, my_nsquare);
1600 // get representation as string
1601 // we always supply some value, so gcry_mpi_print fails only if it can't reserve memory
1602 GNUNET_assert (!gcry_mpi_print (GCRYMPI_FMT_USG,
1603 element_exported, PAILLIER_ELEMENT_LENGTH,
1607 // move buffer content to the end of the buffer so it can easily be read by libgcrypt. also this now has fixed size
1608 adjust (element_exported, element_length, PAILLIER_ELEMENT_LENGTH);
1610 // copy over to the message
1611 memcpy (current, element_exported, PAILLIER_ELEMENT_LENGTH);
1612 current += PAILLIER_ELEMENT_LENGTH;
1615 gcry_mpi_release (a);
1616 GNUNET_free (element_exported);
1618 session->msg = (struct GNUNET_MessageHeader *) msg;
1619 GNUNET_log (GNUNET_ERROR_TYPE_INFO, _ ("Transmitting service request.\n"));
1621 //transmit via mesh messaging
1622 session->service_transmit_handle = GNUNET_MESH_notify_transmit_ready (session->channel, GNUNET_YES,
1623 GNUNET_TIME_UNIT_FOREVER_REL,
1627 if (!session->service_transmit_handle) {
1628 GNUNET_log (GNUNET_ERROR_TYPE_ERROR, _ ("Could not send message to channel!\n"));
1630 session->msg = NULL;
1631 session->client_notification_task =
1632 GNUNET_SCHEDULER_add_now (&prepare_client_end_notification,
1636 if (session->transferred != session->used) {
1637 session->state = WAITING_FOR_MULTIPART_TRANSMISSION;
1638 session->last_processed = i;
1641 //singlepart message
1642 session->state = WAITING_FOR_SERVICE_RESPONSE;
1647 * Handler for a client request message.
1648 * Can either be type A or B
1649 * A: request-initiation to compute a scalar product with a peer
1650 * B: response role, keep the values + session and wait for a matching session or process a waiting request
1652 * @param cls closure
1653 * @param client identification of the client
1654 * @param message the actual message
1657 handle_client_request (void *cls,
1658 struct GNUNET_SERVER_Client *client,
1659 const struct GNUNET_MessageHeader *message)
1661 const struct GNUNET_SCALARPRODUCT_client_request * msg = (const struct GNUNET_SCALARPRODUCT_client_request *) message;
1662 struct ServiceSession * session;
1663 uint32_t element_count;
1664 uint32_t mask_length;
1669 // only one concurrent session per client connection allowed, simplifies logics a lot...
1670 session = GNUNET_SERVER_client_get_user_context (client, struct ServiceSession);
1671 if ((NULL != session) && (session->state != FINALIZED)) {
1672 GNUNET_SERVER_receive_done (client, GNUNET_OK);
1675 else if (NULL != session) {
1676 // old session is already completed, clean it up
1677 GNUNET_CONTAINER_DLL_remove (from_client_head, from_client_tail, session);
1678 free_session_variables (session);
1679 GNUNET_free (session);
1682 //we need at least a peer and one message id to compare
1683 if (sizeof (struct GNUNET_SCALARPRODUCT_client_request) > ntohs (msg->header.size)) {
1684 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
1685 _ ("Too short message received from client!\n"));
1686 GNUNET_SERVER_receive_done (client, GNUNET_SYSERR);
1690 msg_type = ntohs (msg->header.type);
1691 element_count = ntohl (msg->element_count);
1692 mask_length = ntohl (msg->mask_length);
1694 //sanity check: is the message as long as the message_count fields suggests?
1695 if ((ntohs (msg->header.size) != (sizeof (struct GNUNET_SCALARPRODUCT_client_request) +element_count * sizeof (int32_t) + mask_length))
1696 || (0 == element_count)) {
1697 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
1698 _ ("Invalid message received from client, session information incorrect!\n"));
1699 GNUNET_SERVER_receive_done (client, GNUNET_SYSERR);
1703 // do we have a duplicate session here already?
1704 if (NULL != find_matching_session (from_client_tail,
1708 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
1709 _ ("Duplicate session information received, cannot create new session with key `%s'\n"),
1710 GNUNET_h2s (&msg->key));
1711 GNUNET_SERVER_receive_done (client, GNUNET_SYSERR);
1715 session = GNUNET_new (struct ServiceSession);
1716 session->service_request_task = GNUNET_SCHEDULER_NO_TASK;
1717 session->client_notification_task = GNUNET_SCHEDULER_NO_TASK;
1718 session->client = client;
1719 session->total = element_count;
1720 session->mask_length = mask_length;
1721 // get our transaction key
1722 memcpy (&session->key, &msg->key, sizeof (struct GNUNET_HashCode));
1723 //allocate memory for vector and encrypted vector
1724 session->vector = GNUNET_malloc (sizeof (int32_t) * element_count);
1725 vector = (int32_t *) & msg[1];
1727 if (GNUNET_MESSAGE_TYPE_SCALARPRODUCT_CLIENT_TO_ALICE == msg_type) {
1728 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1729 _ ("Got client-request-session with key %s, preparing channel to remote service.\n"),
1730 GNUNET_h2s (&session->key));
1732 session->role = ALICE;
1734 session->mask = GNUNET_malloc (mask_length);
1735 memcpy (session->mask, &vector[element_count], mask_length);
1737 // copy over the elements
1739 for (i = 0; i < element_count; i++) {
1740 session->vector[i] = ntohl (vector[i]);
1741 if (session->vector[i] == 0)
1742 session->mask[i / 8] &= ~(1 << (i % 8));
1743 if (session->mask[i / 8] & (1 << (i % 8)))
1747 if (0 == session->used) {
1748 GNUNET_break_op (0);
1749 GNUNET_free (session->vector);
1750 GNUNET_free (session);
1751 GNUNET_SERVER_receive_done (client, GNUNET_SYSERR);
1754 //session with ourself makes no sense!
1755 if (!memcmp (&msg->peer, &me, sizeof (struct GNUNET_PeerIdentity))) {
1757 GNUNET_free (session->vector);
1758 GNUNET_free (session);
1759 GNUNET_SERVER_receive_done (client, GNUNET_SYSERR);
1763 memcpy (&session->peer, &msg->peer, sizeof (struct GNUNET_PeerIdentity));
1764 GNUNET_log (GNUNET_ERROR_TYPE_INFO,
1765 _ ("Creating new channel for session with key %s.\n"),
1766 GNUNET_h2s (&session->key));
1767 session->channel = GNUNET_MESH_channel_create (my_mesh, session,
1769 GNUNET_APPLICATION_TYPE_SCALARPRODUCT,
1770 GNUNET_MESH_OPTION_RELIABLE);
1771 //prepare_service_request, channel_peer_disconnect_handler,
1772 if (!session->channel) {
1774 GNUNET_free (session->vector);
1775 GNUNET_free (session);
1776 GNUNET_SERVER_receive_done (client, GNUNET_SYSERR);
1779 GNUNET_SERVER_client_set_user_context (client, session);
1780 GNUNET_CONTAINER_DLL_insert (from_client_head, from_client_tail, session);
1782 session->state = CLIENT_REQUEST_RECEIVED;
1783 session->service_request_task =
1784 GNUNET_SCHEDULER_add_now (&prepare_service_request,
1789 struct ServiceSession * requesting_session;
1790 enum SessionState needed_state = SERVICE_REQUEST_RECEIVED;
1792 session->role = BOB;
1793 session->mask = NULL;
1794 // copy over the elements
1795 session->used = element_count;
1796 for (i = 0; i < element_count; i++)
1797 session->vector[i] = ntohl (vector[i]);
1798 session->state = CLIENT_RESPONSE_RECEIVED;
1800 GNUNET_SERVER_client_set_user_context (client, session);
1801 GNUNET_CONTAINER_DLL_insert (from_client_head, from_client_tail, session);
1803 //check if service queue contains a matching request
1804 requesting_session = find_matching_session (from_service_tail,
1807 &needed_state, NULL);
1808 if (NULL != requesting_session) {
1809 GNUNET_log (GNUNET_ERROR_TYPE_INFO, _ ("Got client-responder-session with key %s and a matching service-request-session set, processing.\n"), GNUNET_h2s (&session->key));
1810 if (GNUNET_OK != compute_service_response (requesting_session, session))
1811 session->client_notification_task =
1812 GNUNET_SCHEDULER_add_now (&prepare_client_end_notification,
1817 GNUNET_log (GNUNET_ERROR_TYPE_INFO, _ ("Got client-responder-session with key %s but NO matching service-request-session set, queuing element for later use.\n"), GNUNET_h2s (&session->key));
1818 // no matching session exists yet, store the response
1819 // for later processing by handle_service_request()
1822 GNUNET_SERVER_receive_done (client, GNUNET_YES);
1827 * Function called for inbound channels.
1829 * @param cls closure
1830 * @param channel new handle to the channel
1831 * @param initiator peer that started the channel
1832 * @param port unused
1833 * @param options unused
1835 * @return session associated with the channel
1838 channel_incoming_handler (void *cls,
1839 struct GNUNET_MESH_Channel *channel,
1840 const struct GNUNET_PeerIdentity *initiator,
1841 uint32_t port, enum MeshOption options)
1843 struct ServiceSession * c = GNUNET_new (struct ServiceSession);
1845 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, _ ("New incoming channel from peer %s.\n"), GNUNET_i2s (initiator));
1847 c->peer = *initiator;
1848 c->channel = channel;
1850 c->state = WAITING_FOR_SERVICE_REQUEST;
1856 * Function called whenever a channel is destroyed. Should clean up
1857 * any associated state.
1859 * It must NOT call GNUNET_MESH_channel_destroy on the channel.
1861 * @param cls closure (set from GNUNET_MESH_connect)
1862 * @param channel connection to the other end (henceforth invalid)
1863 * @param channel_ctx place where local state associated
1864 * with the channel is stored
1867 channel_destruction_handler (void *cls,
1868 const struct GNUNET_MESH_Channel *channel,
1871 struct ServiceSession * session = channel_ctx;
1872 struct ServiceSession * client_session;
1873 struct ServiceSession * curr;
1875 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1876 _ ("Peer disconnected, terminating session %s with peer (%s)\n"),
1877 GNUNET_h2s (&session->key),
1878 GNUNET_i2s (&session->peer));
1879 if (ALICE == session->role) {
1880 // as we have only one peer connected in each session, just remove the session
1882 if ((SERVICE_RESPONSE_RECEIVED > session->state) && (!do_shutdown)) {
1883 session->channel = NULL;
1884 // if this happened before we received the answer, we must terminate the session
1885 session->client_notification_task =
1886 GNUNET_SCHEDULER_add_now (&prepare_client_end_notification,
1890 else { //(BOB == session->role) service session
1891 // remove the session, unless it has already been dequeued, but somehow still active
1892 // this could bug without the IF in case the queue is empty and the service session was the only one know to the service
1893 // scenario: disconnect before alice can send her message to bob.
1894 for (curr = from_service_head; NULL != curr; curr = curr->next)
1895 if (curr == session) {
1896 GNUNET_CONTAINER_DLL_remove (from_service_head, from_service_tail, curr);
1899 // there is a client waiting for this service session, terminate it, too!
1900 // i assume the tupel of key and element count is unique. if it was not the rest of the code would not work either.
1901 client_session = find_matching_session (from_client_tail,
1905 free_session_variables (session);
1906 GNUNET_free (session);
1908 // the client has to check if it was waiting for a result
1909 // or if it was a responder, no point in adding more statefulness
1910 if (client_session && (!do_shutdown)) {
1911 client_session->state = FINALIZED;
1912 client_session->client_notification_task =
1913 GNUNET_SCHEDULER_add_now (&prepare_client_end_notification,
1921 * Compute our scalar product, done by Alice
1923 * @param session - the session associated with this computation
1924 * @return product as MPI, never NULL
1927 compute_scalar_product (struct ServiceSession * session)
1938 count = session->used;
1939 // due to the introduced static offset S, we now also have to remove this
1940 // from the E(a_pi)(+)E(-b_pi-r_pi) and E(a_qi)(+)E(-r_qi) twice each,
1941 // the result is E((S + a_pi) + (S -b_pi-r_pi)) and E(S + a_qi + S - r_qi)
1942 for (i = 0; i < count; i++) {
1943 decrypt_element (session->r[i], session->r[i], my_mu, my_lambda, my_n, my_nsquare);
1944 gcry_mpi_sub (session->r[i], session->r[i], my_offset);
1945 gcry_mpi_sub (session->r[i], session->r[i], my_offset);
1946 decrypt_element (session->r_prime[i], session->r_prime[i], my_mu, my_lambda, my_n, my_nsquare);
1947 gcry_mpi_sub (session->r_prime[i], session->r_prime[i], my_offset);
1948 gcry_mpi_sub (session->r_prime[i], session->r_prime[i], my_offset);
1951 // calculate t = sum(ai)
1952 t = compute_square_sum (session->a, count);
1955 u = gcry_mpi_new (0);
1956 tmp = compute_square_sum (session->r, count);
1957 gcry_mpi_sub (u, u, tmp);
1958 gcry_mpi_release (tmp);
1961 u_prime = gcry_mpi_new (0);
1962 tmp = compute_square_sum (session->r_prime, count);
1963 gcry_mpi_sub (u_prime, u_prime, tmp);
1965 GNUNET_assert (p = gcry_mpi_new (0));
1966 GNUNET_assert (p_prime = gcry_mpi_new (0));
1969 decrypt_element (session->s, session->s, my_mu, my_lambda, my_n, my_nsquare);
1970 decrypt_element (session->s_prime, session->s_prime, my_mu, my_lambda, my_n, my_nsquare);
1973 gcry_mpi_add (p, session->s, t);
1974 gcry_mpi_add (p, p, u);
1977 gcry_mpi_add (p_prime, session->s_prime, t);
1978 gcry_mpi_add (p_prime, p_prime, u_prime);
1980 gcry_mpi_release (t);
1981 gcry_mpi_release (u);
1982 gcry_mpi_release (u_prime);
1985 gcry_mpi_sub (p, p, p_prime);
1986 gcry_mpi_release (p_prime);
1987 tmp = gcry_mpi_set_ui (tmp, 2);
1988 gcry_mpi_div (p, NULL, p, tmp, 0);
1990 gcry_mpi_release (tmp);
1991 for (i = 0; i < count; i++)
1992 gcry_mpi_release (session->a[i]);
1993 GNUNET_free (session->a);
2001 * Handle a multipart-chunk of a request from another service to calculate a scalarproduct with us.
2003 * @param cls closure (set from #GNUNET_MESH_connect)
2004 * @param channel connection to the other end
2005 * @param channel_ctx place to store local state associated with the channel
2006 * @param message the actual message
2007 * @return #GNUNET_OK to keep the connection open,
2008 * #GNUNET_SYSERR to close it (signal serious error)
2011 handle_service_request_multipart (void *cls,
2012 struct GNUNET_MESH_Channel * channel,
2014 const struct GNUNET_MessageHeader * message)
2016 struct ServiceSession * session;
2017 const struct GNUNET_SCALARPRODUCT_multipart_message * msg = (const struct GNUNET_SCALARPRODUCT_multipart_message *) message;
2018 uint32_t used_elements;
2019 uint32_t contained_elements = 0;
2020 uint32_t msg_length;
2021 unsigned char * current;
2025 // are we in the correct state?
2026 session = (struct ServiceSession *) * channel_ctx;
2027 if ((BOB != session->role) || (WAITING_FOR_MULTIPART_TRANSMISSION != session->state)) {
2030 // shorter than minimum?
2031 if (ntohs (msg->header.size) <= sizeof (struct GNUNET_SCALARPRODUCT_multipart_message)) {
2034 used_elements = session->used;
2035 contained_elements = ntohl (msg->multipart_element_count);
2036 msg_length = sizeof (struct GNUNET_SCALARPRODUCT_multipart_message)
2037 +contained_elements * PAILLIER_ELEMENT_LENGTH;
2039 if ((ntohs (msg->header.size) != msg_length)
2040 || (used_elements < contained_elements + session->transferred)) {
2043 current = (unsigned char *) &msg[1];
2044 if (contained_elements != 0) {
2045 // Convert each vector element to MPI_value
2046 for (i = session->transferred; i < session->transferred + contained_elements; i++) {
2048 if (0 != (rc = gcry_mpi_scan (&session->a[i],
2050 ¤t[i * PAILLIER_ELEMENT_LENGTH],
2051 PAILLIER_ELEMENT_LENGTH,
2053 LOG_GCRY (GNUNET_ERROR_TYPE_DEBUG, "gcry_mpi_scan", rc);
2057 session->transferred += contained_elements;
2059 if (session->transferred == used_elements) {
2060 // single part finished
2061 session->state = SERVICE_REQUEST_RECEIVED;
2062 if (session->response) {
2063 GNUNET_log (GNUNET_ERROR_TYPE_INFO, _ ("Got session with key %s and a matching element set, processing.\n"), GNUNET_h2s (&session->key));
2064 if (GNUNET_OK != compute_service_response (session, session->response)) {
2065 //something went wrong, remove it again...
2070 GNUNET_log (GNUNET_ERROR_TYPE_INFO, _ ("Got session with key %s without a matching element set, queueing.\n"), GNUNET_h2s (&session->key));
2073 // multipart message
2079 // and notify our client-session that we could not complete the session
2080 GNUNET_CONTAINER_DLL_remove (from_service_head, from_service_tail, session);
2081 if (session->response)
2082 // we just found the responder session in this queue
2083 session->response->client_notification_task =
2084 GNUNET_SCHEDULER_add_now (&prepare_client_end_notification,
2086 free_session_variables (session);
2087 GNUNET_free (session);
2088 return GNUNET_SYSERR;
2093 * Handle a request from another service to calculate a scalarproduct with us.
2095 * @param cls closure (set from #GNUNET_MESH_connect)
2096 * @param channel connection to the other end
2097 * @param channel_ctx place to store local state associated with the channel
2098 * @param message the actual message
2099 * @return #GNUNET_OK to keep the connection open,
2100 * #GNUNET_SYSERR to close it (signal serious error)
2103 handle_service_request (void *cls,
2104 struct GNUNET_MESH_Channel * channel,
2106 const struct GNUNET_MessageHeader * message)
2108 struct ServiceSession * session;
2109 const struct GNUNET_SCALARPRODUCT_service_request * msg = (const struct GNUNET_SCALARPRODUCT_service_request *) message;
2110 uint32_t mask_length;
2112 uint32_t used_elements;
2113 uint32_t contained_elements = 0;
2114 uint32_t element_count;
2115 uint32_t msg_length;
2116 unsigned char * current;
2119 enum SessionState needed_state;
2121 session = (struct ServiceSession *) * channel_ctx;
2122 if (WAITING_FOR_SERVICE_REQUEST != session->state) {
2125 // Check if message was sent by me, which would be bad!
2126 if (!memcmp (&session->peer, &me, sizeof (struct GNUNET_PeerIdentity))) {
2127 GNUNET_free (session);
2129 return GNUNET_SYSERR;
2131 // shorter than expected?
2132 if (ntohs (msg->header.size) < sizeof (struct GNUNET_SCALARPRODUCT_service_request)) {
2133 GNUNET_free (session);
2134 GNUNET_break_op (0);
2135 return GNUNET_SYSERR;
2137 mask_length = ntohl (msg->mask_length);
2138 pk_length = ntohl (msg->pk_length);
2139 used_elements = ntohl (msg->total_element_count);
2140 contained_elements = ntohl (msg->contained_element_count);
2141 element_count = ntohl (msg->element_count);
2142 msg_length = sizeof (struct GNUNET_SCALARPRODUCT_service_request)
2143 +mask_length + pk_length + contained_elements * PAILLIER_ELEMENT_LENGTH;
2145 //sanity check: is the message as long as the message_count fields suggests?
2146 if ((ntohs (msg->header.size) != msg_length) || (element_count < used_elements) || (used_elements < contained_elements)
2147 || (used_elements == 0) || (mask_length != (element_count / 8 + (element_count % 8 ? 1 : 0)))
2149 GNUNET_free (session);
2150 GNUNET_break_op (0);
2151 return GNUNET_SYSERR;
2153 if (find_matching_session (from_service_tail,
2158 GNUNET_log (GNUNET_ERROR_TYPE_ERROR, _ ("Got message with duplicate session key (`%s'), ignoring service request.\n"), (const char *) &(msg->key));
2159 GNUNET_free (session);
2160 return GNUNET_SYSERR;
2163 session->total = element_count;
2164 session->used = used_elements;
2165 session->transferred = contained_elements;
2166 session->channel = channel;
2169 memcpy (&session->key, &msg->key, sizeof (struct GNUNET_HashCode));
2170 current = (unsigned char *) &msg[1];
2171 //preserve the mask, we will need that later on
2172 session->mask = GNUNET_malloc (mask_length);
2173 memcpy (session->mask, current, mask_length);
2175 current += mask_length;
2177 //convert the publickey to sexp
2178 if (0 != (rc = gcry_sexp_new (&session->remote_pubkey, current, pk_length, 1))) {
2179 LOG_GCRY (GNUNET_ERROR_TYPE_DEBUG, "gcry_sexp_new", rc);
2180 GNUNET_free (session->mask);
2181 GNUNET_free (session);
2182 return GNUNET_SYSERR;
2184 current += pk_length;
2185 //check if service queue contains a matching request
2186 needed_state = CLIENT_RESPONSE_RECEIVED;
2187 session->response = find_matching_session (from_client_tail,
2190 &needed_state, NULL);
2192 session->a = GNUNET_malloc (sizeof (gcry_mpi_t) * used_elements);
2193 session->state = WAITING_FOR_MULTIPART_TRANSMISSION;
2194 GNUNET_CONTAINER_DLL_insert (from_service_head, from_service_tail, session);
2195 if (contained_elements != 0) {
2196 // Convert each vector element to MPI_value
2197 for (i = 0; i < contained_elements; i++) {
2199 if (0 != (rc = gcry_mpi_scan (&session->a[i],
2201 ¤t[i * PAILLIER_ELEMENT_LENGTH],
2202 PAILLIER_ELEMENT_LENGTH,
2204 LOG_GCRY (GNUNET_ERROR_TYPE_DEBUG, "gcry_mpi_scan", rc);
2208 if (contained_elements == used_elements) {
2209 // single part finished
2210 session->state = SERVICE_REQUEST_RECEIVED;
2211 if (session->response) {
2212 GNUNET_log (GNUNET_ERROR_TYPE_INFO, _ ("Got session with key %s and a matching element set, processing.\n"), GNUNET_h2s (&session->key));
2213 if (GNUNET_OK != compute_service_response (session, session->response)) {
2214 //something went wrong, remove it again...
2219 GNUNET_log (GNUNET_ERROR_TYPE_INFO, _ ("Got session with key %s without a matching element set, queueing.\n"), GNUNET_h2s (&session->key));
2222 // multipart message
2227 GNUNET_break_op (0);
2228 if ((NULL != session->next) || (NULL != session->prev) || (from_service_head == session))
2229 GNUNET_CONTAINER_DLL_remove (from_service_head, from_service_tail, session);
2230 // and notify our client-session that we could not complete the session
2231 if (session->response)
2232 // we just found the responder session in this queue
2233 session->response->client_notification_task =
2234 GNUNET_SCHEDULER_add_now (&prepare_client_end_notification,
2236 free_session_variables (session);
2237 return GNUNET_SYSERR;
2242 * Handle a multipart chunk of a response we got from another service we wanted to calculate a scalarproduct with.
2244 * @param cls closure (set from #GNUNET_MESH_connect)
2245 * @param channel connection to the other end
2246 * @param channel_ctx place to store local state associated with the channel
2247 * @param message the actual message
2248 * @return #GNUNET_OK to keep the connection open,
2249 * #GNUNET_SYSERR to close it (signal serious error)
2252 handle_service_response_multipart (void *cls,
2253 struct GNUNET_MESH_Channel * channel,
2255 const struct GNUNET_MessageHeader * message)
2257 struct ServiceSession * session;
2258 const struct GNUNET_SCALARPRODUCT_multipart_message * msg = (const struct GNUNET_SCALARPRODUCT_multipart_message *) message;
2259 unsigned char * current;
2262 uint32_t contained = 0;
2264 size_t required_size;
2267 GNUNET_assert (NULL != message);
2268 // are we in the correct state?
2269 session = (struct ServiceSession *) * channel_ctx;
2270 if ((ALICE != session->role) || (WAITING_FOR_MULTIPART_TRANSMISSION != session->state)) {
2273 msg_size = ntohs (msg->header.size);
2274 required_size = sizeof (struct GNUNET_SCALARPRODUCT_multipart_message) + 2 * PAILLIER_ELEMENT_LENGTH;
2275 // shorter than minimum?
2276 if (required_size > msg_size) {
2279 contained = ntohl (msg->multipart_element_count);
2280 required_size = sizeof (struct GNUNET_SCALARPRODUCT_multipart_message)
2281 + 2 * contained * PAILLIER_ELEMENT_LENGTH;
2282 //sanity check: is the message as long as the message_count fields suggests?
2283 if ((required_size != msg_size) || (session->used < session->transferred + contained)) {
2286 current = (unsigned char *) &msg[1];
2287 // Convert each k[][perm] to its MPI_value
2288 for (i = 0; i < contained; i++) {
2289 if (0 != (rc = gcry_mpi_scan (&session->r[i], GCRYMPI_FMT_USG, current,
2290 PAILLIER_ELEMENT_LENGTH, &read))) {
2291 LOG_GCRY (GNUNET_ERROR_TYPE_DEBUG, "gcry_mpi_scan", rc);
2294 current += PAILLIER_ELEMENT_LENGTH;
2295 if (0 != (rc = gcry_mpi_scan (&session->r_prime[i], GCRYMPI_FMT_USG, current,
2296 PAILLIER_ELEMENT_LENGTH, &read))) {
2297 LOG_GCRY (GNUNET_ERROR_TYPE_DEBUG, "gcry_mpi_scan", rc);
2300 current += PAILLIER_ELEMENT_LENGTH;
2302 session->transferred += contained;
2303 if (session->transferred != session->used)
2305 session->state = SERVICE_RESPONSE_RECEIVED;
2306 session->product = compute_scalar_product (session); //never NULL
2309 GNUNET_break_op (NULL != session->product);
2311 // send message with product to client
2312 if (ALICE == session->role){
2313 session->state = FINALIZED;
2314 session->channel = NULL;
2315 session->client_notification_task =
2316 GNUNET_SCHEDULER_add_now (&prepare_client_response,
2319 // the channel has done its job, terminate our connection and the channel
2320 // the peer will be notified that the channel was destroyed via channel_destruction_handler
2321 // just close the connection, as recommended by Christian
2322 return GNUNET_SYSERR;
2327 * Handle a response we got from another service we wanted to calculate a scalarproduct with.
2329 * @param cls closure (set from #GNUNET_MESH_connect)
2330 * @param channel connection to the other end
2331 * @param channel_ctx place to store local state associated with the channel
2332 * @param message the actual message
2333 * @return #GNUNET_OK to keep the connection open,
2334 * #GNUNET_SYSERR to close it (we are done)
2337 handle_service_response (void *cls,
2338 struct GNUNET_MESH_Channel * channel,
2340 const struct GNUNET_MessageHeader * message)
2342 struct ServiceSession * session;
2343 const struct GNUNET_SCALARPRODUCT_service_response * msg = (const struct GNUNET_SCALARPRODUCT_service_response *) message;
2344 unsigned char * current;
2347 uint32_t contained = 0;
2349 size_t required_size;
2352 GNUNET_assert (NULL != message);
2353 session = (struct ServiceSession *) * channel_ctx;
2354 // are we in the correct state?
2355 if (WAITING_FOR_SERVICE_RESPONSE != session->state) {
2358 //we need at least a full message without elements attached
2359 msg_size = ntohs (msg->header.size);
2360 required_size = sizeof (struct GNUNET_SCALARPRODUCT_service_response) + 2 * PAILLIER_ELEMENT_LENGTH;
2362 if (required_size > msg_size) {
2365 contained = ntohl (msg->contained_element_count);
2366 required_size = sizeof (struct GNUNET_SCALARPRODUCT_service_response)
2367 + 2 * contained * PAILLIER_ELEMENT_LENGTH
2368 + 2 * PAILLIER_ELEMENT_LENGTH;
2369 //sanity check: is the message as long as the message_count fields suggests?
2370 if ((msg_size != required_size) || (session->used < contained)) {
2373 session->state = WAITING_FOR_MULTIPART_TRANSMISSION;
2374 session->transferred = contained;
2376 current = (unsigned char *) &msg[1];
2377 if (0 != (rc = gcry_mpi_scan (&session->s, GCRYMPI_FMT_USG, current,
2378 PAILLIER_ELEMENT_LENGTH, &read))) {
2379 LOG_GCRY (GNUNET_ERROR_TYPE_DEBUG, "gcry_mpi_scan", rc);
2382 current += PAILLIER_ELEMENT_LENGTH;
2384 if (0 != (rc = gcry_mpi_scan (&session->s_prime, 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;
2390 session->r = GNUNET_malloc (sizeof (gcry_mpi_t) * session->used);
2391 session->r_prime = GNUNET_malloc (sizeof (gcry_mpi_t) * session->used);
2392 // Convert each k[][perm] to its MPI_value
2393 for (i = 0; i < contained; i++) {
2394 if (0 != (rc = gcry_mpi_scan (&session->r[i], GCRYMPI_FMT_USG, current,
2395 PAILLIER_ELEMENT_LENGTH, &read))) {
2396 LOG_GCRY (GNUNET_ERROR_TYPE_DEBUG, "gcry_mpi_scan", rc);
2399 current += PAILLIER_ELEMENT_LENGTH;
2400 if (0 != (rc = gcry_mpi_scan (&session->r_prime[i], GCRYMPI_FMT_USG, current,
2401 PAILLIER_ELEMENT_LENGTH, &read))) {
2402 LOG_GCRY (GNUNET_ERROR_TYPE_DEBUG, "gcry_mpi_scan", rc);
2405 current += PAILLIER_ELEMENT_LENGTH;
2407 if (session->transferred != session->used)
2408 return GNUNET_OK; //wait for the other multipart chunks
2410 session->state = SERVICE_RESPONSE_RECEIVED;
2411 session->product = compute_scalar_product (session); //never NULL
2414 GNUNET_break_op (NULL != session->product);
2415 // send message with product to client
2416 if (ALICE == session->role){
2417 session->state = FINALIZED;
2418 session->channel = NULL;
2419 session->client_notification_task =
2420 GNUNET_SCHEDULER_add_now (&prepare_client_response,
2423 // the channel has done its job, terminate our connection and the channel
2424 // the peer will be notified that the channel was destroyed via channel_destruction_handler
2425 // just close the connection, as recommended by Christian
2426 return GNUNET_SYSERR;
2431 * Task run during shutdown.
2437 shutdown_task (void *cls,
2438 const struct GNUNET_SCHEDULER_TaskContext *tc)
2440 struct ServiceSession * session;
2441 GNUNET_log (GNUNET_ERROR_TYPE_INFO, _ ("Shutting down, initiating cleanup.\n"));
2443 do_shutdown = GNUNET_YES;
2445 // terminate all owned open channels.
2446 for (session = from_client_head; NULL != session; session = session->next) {
2447 if ((FINALIZED != session->state) && (NULL != session->channel)) {
2448 GNUNET_MESH_channel_destroy (session->channel);
2449 session->channel = NULL;
2451 if (GNUNET_SCHEDULER_NO_TASK != session->client_notification_task) {
2452 GNUNET_SCHEDULER_cancel (session->client_notification_task);
2453 session->client_notification_task = GNUNET_SCHEDULER_NO_TASK;
2455 if (GNUNET_SCHEDULER_NO_TASK != session->service_request_task) {
2456 GNUNET_SCHEDULER_cancel (session->service_request_task);
2457 session->service_request_task = GNUNET_SCHEDULER_NO_TASK;
2459 if (NULL != session->client) {
2460 GNUNET_SERVER_client_disconnect (session->client);
2461 session->client = NULL;
2464 for (session = from_service_head; NULL != session; session = session->next)
2465 if (NULL != session->channel) {
2466 GNUNET_MESH_channel_destroy (session->channel);
2467 session->channel = NULL;
2471 GNUNET_MESH_disconnect (my_mesh);
2478 * Initialization of the program and message handlers
2480 * @param cls closure
2481 * @param server the initialized server
2482 * @param c configuration to use
2486 struct GNUNET_SERVER_Handle *server,
2487 const struct GNUNET_CONFIGURATION_Handle *c)
2489 static const struct GNUNET_SERVER_MessageHandler server_handlers[] = {
2490 {&handle_client_request, NULL, GNUNET_MESSAGE_TYPE_SCALARPRODUCT_CLIENT_TO_ALICE, 0},
2491 {&handle_client_request, NULL, GNUNET_MESSAGE_TYPE_SCALARPRODUCT_CLIENT_TO_BOB, 0},
2494 static const struct GNUNET_MESH_MessageHandler mesh_handlers[] = {
2495 { &handle_service_request, GNUNET_MESSAGE_TYPE_SCALARPRODUCT_ALICE_TO_BOB, 0},
2496 { &handle_service_request_multipart, GNUNET_MESSAGE_TYPE_SCALARPRODUCT_ALICE_TO_BOB_MULTIPART, 0},
2497 { &handle_service_response, GNUNET_MESSAGE_TYPE_SCALARPRODUCT_BOB_TO_ALICE, 0},
2498 { &handle_service_response_multipart, GNUNET_MESSAGE_TYPE_SCALARPRODUCT_BOB_TO_ALICE_MULTIPART, 0},
2501 static const uint32_t ports[] = {
2502 GNUNET_APPLICATION_TYPE_SCALARPRODUCT,
2505 //generate private/public key set
2506 GNUNET_log (GNUNET_ERROR_TYPE_INFO, _ ("Generating Paillier-Keyset.\n"));
2508 // register server callbacks and disconnect handler
2509 GNUNET_SERVER_add_handlers (server, server_handlers);
2510 GNUNET_SERVER_disconnect_notify (server,
2511 &handle_client_disconnect,
2513 GNUNET_break (GNUNET_OK ==
2514 GNUNET_CRYPTO_get_peer_identity (c,
2516 my_mesh = GNUNET_MESH_connect (c, NULL,
2517 &channel_incoming_handler,
2518 &channel_destruction_handler,
2519 mesh_handlers, ports);
2521 GNUNET_log (GNUNET_ERROR_TYPE_ERROR, _ ("Connect to MESH failed\n"));
2522 GNUNET_SCHEDULER_shutdown ();
2525 GNUNET_log (GNUNET_ERROR_TYPE_INFO, _ ("Mesh initialized\n"));
2526 GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_FOREVER_REL,
2533 * The main function for the scalarproduct service.
2535 * @param argc number of arguments from the command line
2536 * @param argv command line arguments
2537 * @return 0 ok, 1 on error
2540 main (int argc, char *const *argv)
2542 return (GNUNET_OK ==
2543 GNUNET_SERVICE_run (argc, argv,
2545 GNUNET_SERVICE_OPTION_NONE,
2546 &run, NULL)) ? 0 : 1;
2549 /* end of gnunet-service-scalarproduct.c */