2 This file is part of GNUnet.
3 (C) 2013, 2014 Christian Grothoff (and other contributing authors)
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12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 General Public License for more details.
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21 * @file scalarproduct/gnunet-service-scalarproduct_bob.c
22 * @brief scalarproduct service implementation
23 * @author Christian M. Fuchs
24 * @author Christian Grothoff
29 #include "gnunet_util_lib.h"
30 #include "gnunet_core_service.h"
31 #include "gnunet_cadet_service.h"
32 #include "gnunet_applications.h"
33 #include "gnunet_protocols.h"
34 #include "gnunet_scalarproduct_service.h"
35 #include "gnunet_set_service.h"
36 #include "scalarproduct.h"
37 #include "gnunet-service-scalarproduct.h"
39 #define LOG(kind,...) GNUNET_log_from (kind, "scalarproduct-bob", __VA_ARGS__)
43 * An encrypted element key-value pair.
48 * Key used to identify matching pairs of values to multiply.
49 * Points into an existing data structure, to avoid copying
50 * and doubling memory use.
52 const struct GNUNET_HashCode *key;
55 * Value represented (a).
62 * An incoming session from CADET.
64 struct CadetIncomingSession;
68 * A scalarproduct session which tracks an offer for a
69 * multiplication service by a local client.
71 struct BobServiceSession
75 * (hopefully) unique transaction ID
77 struct GNUNET_HashCode session_id;
80 * The client this request is related to.
82 struct GNUNET_SERVER_Client *client;
85 * Client message queue.
87 struct GNUNET_MQ_Handle *client_mq;
90 * All non-0-value'd elements transmitted to us.
92 struct GNUNET_CONTAINER_MultiHashMap *intersected_elements;
95 * Set of elements for which we will be conducting an intersection.
96 * The resulting elements are then used for computing the scalar product.
98 struct GNUNET_SET_Handle *intersection_set;
101 * Set of elements for which will conduction an intersection.
102 * the resulting elements are then used for computing the scalar product.
104 struct GNUNET_SET_OperationHandle *intersection_op;
109 struct MpiElement *sorted_elements;
112 * E(ai)(Bob) after applying the mask
114 struct GNUNET_CRYPTO_PaillierCiphertext *e_a;
117 * Bob's permutation p of R
119 struct GNUNET_CRYPTO_PaillierCiphertext *r;
122 * Bob's permutation q of R
124 struct GNUNET_CRYPTO_PaillierCiphertext *r_prime;
129 struct GNUNET_CRYPTO_PaillierCiphertext s;
134 struct GNUNET_CRYPTO_PaillierCiphertext s_prime;
137 * Handle for our associated incoming CADET session, or NULL
138 * if we have not gotten one yet.
140 struct CadetIncomingSession *cadet;
143 * The computed scalar
148 * How many elements will be supplied in total from the client.
153 * Already transferred elements (received) for multipart
154 * messages from client. Always less than @e total.
156 uint32_t client_received_element_count;
159 * How many elements actually are used for the scalar product.
160 * Size of the arrays in @e r and @e r_prime. Also sometimes
161 * used as an index into the arrays during construction.
163 uint32_t used_element_count;
166 * Counts the number of values received from Alice by us.
167 * Always less than @e used_element_count.
169 uint32_t cadet_received_element_count;
172 * Counts the number of values transmitted from us to Alice.
173 * Always less than @e used_element_count.
175 uint32_t cadet_transmitted_element_count;
178 * State of this session. In
179 * #GNUNET_SCALARPRODUCT_STATUS_ACTIVE while operation is
180 * ongoing, afterwards in #GNUNET_SCALARPRODUCT_STATUS_SUCCESS or
181 * #GNUNET_SCALARPRODUCT_STATUS_FAILURE.
183 enum GNUNET_SCALARPRODUCT_ResponseStatus status;
186 * Are we already in #destroy_service_session()?
194 * An incoming session from CADET.
196 struct CadetIncomingSession
200 * Associated client session, or NULL.
202 struct BobServiceSession *s;
207 struct GNUNET_CADET_Channel *channel;
210 * Originator's peer identity. (Only for diagnostics.)
212 struct GNUNET_PeerIdentity peer;
215 * (hopefully) unique transaction ID
217 struct GNUNET_HashCode session_id;
220 * Public key of the remote service.
222 struct GNUNET_CRYPTO_PaillierPublicKey remote_pubkey;
225 * The message queue for this channel.
227 struct GNUNET_MQ_Handle *cadet_mq;
230 * Has this CADET session been added to the map yet?
231 * #GNUNET_YES if so, in which case @e session_id is
237 * Are we already in #destroy_cadet_session()?
245 * GNUnet configuration handle
247 static const struct GNUNET_CONFIGURATION_Handle *cfg;
250 * Service's own public key
252 static struct GNUNET_CRYPTO_PaillierPublicKey my_pubkey;
255 * Service's own private key
257 static struct GNUNET_CRYPTO_PaillierPrivateKey my_privkey;
260 * Service's offset for values that could possibly be negative but are plaintext for encryption.
262 static gcry_mpi_t my_offset;
265 * Map of `struct BobServiceSession`, by session keys.
267 static struct GNUNET_CONTAINER_MultiHashMap *client_sessions;
270 * Map of `struct CadetIncomingSession`, by session keys.
272 static struct GNUNET_CONTAINER_MultiHashMap *cadet_sessions;
275 * Handle to the CADET service.
277 static struct GNUNET_CADET_Handle *my_cadet;
282 * Finds a not terminated client session in the respective map based on
285 * @param key the session key we want to search for
286 * @return the matching session, or NULL for none
288 static struct BobServiceSession *
289 find_matching_client_session (const struct GNUNET_HashCode *key)
291 return GNUNET_CONTAINER_multihashmap_get (client_sessions,
297 * Finds a CADET session in the respective map based on session key.
299 * @param key the session key we want to search for
300 * @return the matching session, or NULL for none
302 static struct CadetIncomingSession *
303 find_matching_cadet_session (const struct GNUNET_HashCode *key)
305 return GNUNET_CONTAINER_multihashmap_get (cadet_sessions,
311 * Callback used to free the elements in the map.
314 * @param key key of the element
315 * @param value the value to free
318 free_element_cb (void *cls,
319 const struct GNUNET_HashCode *key,
322 struct GNUNET_SCALARPRODUCT_Element *element = value;
324 GNUNET_free (element);
330 * Destroy session state, we are done with it.
332 * @param session the session to free elements from
335 destroy_cadet_session (struct CadetIncomingSession *s);
339 * Destroy session state, we are done with it.
341 * @param session the session to free elements from
344 destroy_service_session (struct BobServiceSession *s)
346 struct CadetIncomingSession *in;
349 if (GNUNET_YES == s->in_destroy)
351 s->in_destroy = GNUNET_YES;
352 if (NULL != (in = s->cadet))
355 destroy_cadet_session (in);
357 if (NULL != s->client_mq)
359 GNUNET_MQ_destroy (s->client_mq);
362 if (NULL != s->client)
364 GNUNET_SERVER_client_disconnect (s->client);
367 GNUNET_assert (GNUNET_YES ==
368 GNUNET_CONTAINER_multihashmap_remove (client_sessions,
371 if (NULL != s->intersected_elements)
373 GNUNET_CONTAINER_multihashmap_iterate (s->intersected_elements,
376 GNUNET_CONTAINER_multihashmap_destroy (s->intersected_elements);
377 s->intersected_elements = NULL;
379 if (NULL != s->intersection_op)
381 GNUNET_SET_operation_cancel (s->intersection_op);
382 s->intersection_op = NULL;
384 if (NULL != s->intersection_set)
386 GNUNET_SET_destroy (s->intersection_set);
387 s->intersection_set = NULL;
391 GNUNET_free (s->e_a);
394 if (NULL != s->sorted_elements)
396 for (i=0;i<s->used_element_count;i++)
397 gcry_mpi_release (s->sorted_elements[i].value);
398 GNUNET_free (s->sorted_elements);
399 s->sorted_elements = NULL;
406 if (NULL != s->r_prime)
408 GNUNET_free (s->r_prime);
411 if (NULL != s->product)
413 gcry_mpi_release (s->product);
421 * Destroy incoming CADET session state, we are done with it.
423 * @param in the session to free elements from
426 destroy_cadet_session (struct CadetIncomingSession *in)
428 struct BobServiceSession *s;
430 if (GNUNET_YES == in->in_destroy)
432 in->in_destroy = GNUNET_YES;
433 if (NULL != (s = in->s))
436 destroy_service_session (s);
438 if (GNUNET_YES == in->in_map)
440 GNUNET_assert (GNUNET_YES ==
441 GNUNET_CONTAINER_multihashmap_remove (cadet_sessions,
444 in->in_map = GNUNET_NO;
446 if (NULL != in->cadet_mq)
448 GNUNET_MQ_destroy (in->cadet_mq);
451 if (NULL != in->channel)
453 GNUNET_CADET_channel_destroy (in->channel);
461 * Notify the client that the session has succeeded or failed. This
462 * message gets sent to Bob's client if the operation completed or
463 * Alice disconnected.
465 * @param session the associated client session to fail or succeed
468 prepare_client_end_notification (struct BobServiceSession *session)
470 struct ClientResponseMessage *msg;
471 struct GNUNET_MQ_Envelope *e;
473 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
474 "Sending session-end notification with status %d to client for session %s\n",
476 GNUNET_h2s (&session->session_id));
477 e = GNUNET_MQ_msg (msg,
478 GNUNET_MESSAGE_TYPE_SCALARPRODUCT_RESULT);
480 msg->product_length = htonl (0);
481 msg->status = htonl (session->status);
482 GNUNET_MQ_send (session->client_mq,
488 * Function called whenever a channel is destroyed. Should clean up
489 * any associated state.
491 * It must NOT call #GNUNET_CADET_channel_destroy() on the channel.
493 * @param cls closure (set from #GNUNET_CADET_connect())
494 * @param channel connection to the other end (henceforth invalid)
495 * @param channel_ctx place where local state associated
496 * with the channel is stored
499 cb_channel_destruction (void *cls,
500 const struct GNUNET_CADET_Channel *channel,
503 struct CadetIncomingSession *in = channel_ctx;
504 struct BobServiceSession *s;
506 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
507 "Peer disconnected, terminating session %s with peer %s\n",
508 GNUNET_h2s (&in->session_id),
509 GNUNET_i2s (&in->peer));
510 if (NULL != in->cadet_mq)
512 GNUNET_MQ_destroy (in->cadet_mq);
516 if (NULL != (s = in->s))
518 if (GNUNET_SCALARPRODUCT_STATUS_ACTIVE == s->status)
520 s->status = GNUNET_SCALARPRODUCT_STATUS_FAILURE;
521 prepare_client_end_notification (s);
524 destroy_cadet_session (in);
529 * MQ finished giving our last message to CADET, now notify
530 * the client that we are finished.
533 bob_cadet_done_cb (void *cls)
535 struct BobServiceSession *session = cls;
537 session->status = GNUNET_SCALARPRODUCT_STATUS_SUCCESS;
538 prepare_client_end_notification (session);
543 * Maximum count of elements we can put into a multipart message
545 #define ELEMENT_CAPACITY ((GNUNET_SERVER_MAX_MESSAGE_SIZE - 1 - sizeof (struct BobCryptodataMultipartMessage)) / sizeof (struct GNUNET_CRYPTO_PaillierCiphertext))
549 * Send a multipart chunk of a service response from Bob to Alice.
550 * This element only contains the two permutations of R, R'.
552 * @param s the associated service session
555 transmit_bobs_cryptodata_message_multipart (struct BobServiceSession *s)
557 struct GNUNET_CRYPTO_PaillierCiphertext *payload;
558 struct BobCryptodataMultipartMessage *msg;
559 struct GNUNET_MQ_Envelope *e;
564 while (s->cadet_transmitted_element_count != s->used_element_count)
566 todo_count = s->used_element_count - s->cadet_transmitted_element_count;
567 if (todo_count > ELEMENT_CAPACITY / 2)
568 todo_count = ELEMENT_CAPACITY / 2;
570 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
571 "Sending %u additional crypto values to Alice\n",
572 (unsigned int) todo_count);
573 e = GNUNET_MQ_msg_extra (msg,
574 todo_count * sizeof (struct GNUNET_CRYPTO_PaillierCiphertext) * 2,
575 GNUNET_MESSAGE_TYPE_SCALARPRODUCT_BOB_CRYPTODATA_MULTIPART);
576 msg->contained_element_count = htonl (todo_count);
577 payload = (struct GNUNET_CRYPTO_PaillierCiphertext *) &msg[1];
578 for (i = s->cadet_transmitted_element_count, j = 0; i < s->cadet_transmitted_element_count + todo_count; i++)
580 //r[i][p] and r[i][q]
581 memcpy (&payload[j++],
583 sizeof (struct GNUNET_CRYPTO_PaillierCiphertext));
584 memcpy (&payload[j++],
586 sizeof (struct GNUNET_CRYPTO_PaillierCiphertext));
588 s->cadet_transmitted_element_count += todo_count;
589 if (s->cadet_transmitted_element_count == s->used_element_count)
590 GNUNET_MQ_notify_sent (e,
593 GNUNET_MQ_send (s->cadet->cadet_mq,
600 * Bob generates the response message to be sent to Alice after
601 * computing the values (1), (2), S and S'.
603 * (1)[]: $E_A(a_{pi(i)}) times E_A(- r_{pi(i)} - b_{pi(i)}) &= E_A(a_{pi(i)} - r_{pi(i)} - b_{pi(i)})$
604 * (2)[]: $E_A(a_{pi'(i)}) times E_A(- r_{pi'(i)}) &= E_A(a_{pi'(i)} - r_{pi'(i)})$
605 * S: $S := E_A(sum (r_i + b_i)^2)$
606 * S': $S' := E_A(sum r_i^2)$
608 * @param s the associated requesting session with Alice
611 transmit_bobs_cryptodata_message (struct BobServiceSession *s)
613 struct BobCryptodataMessage *msg;
614 struct GNUNET_MQ_Envelope *e;
615 struct GNUNET_CRYPTO_PaillierCiphertext *payload;
618 s->cadet_transmitted_element_count = (GNUNET_SERVER_MAX_MESSAGE_SIZE - 1 - sizeof (struct BobCryptodataMessage)) /
619 (sizeof (struct GNUNET_CRYPTO_PaillierCiphertext) * 2) - 2;
620 if (s->cadet_transmitted_element_count > s->used_element_count)
621 s->cadet_transmitted_element_count = s->used_element_count;
623 e = GNUNET_MQ_msg_extra (msg,
624 (2 + s->cadet_transmitted_element_count * 2)
625 * sizeof (struct GNUNET_CRYPTO_PaillierCiphertext),
626 GNUNET_MESSAGE_TYPE_SCALARPRODUCT_BOB_CRYPTODATA);
627 msg->contained_element_count = htonl (s->cadet_transmitted_element_count);
629 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
630 "Sending %u/%u crypto values to Alice\n",
631 (unsigned int) s->cadet_transmitted_element_count,
632 (unsigned int) s->used_element_count);
634 payload = (struct GNUNET_CRYPTO_PaillierCiphertext *) &msg[1];
637 sizeof (struct GNUNET_CRYPTO_PaillierCiphertext));
640 sizeof (struct GNUNET_CRYPTO_PaillierCiphertext));
642 payload = &payload[2];
644 for (i = 0; i < s->cadet_transmitted_element_count; i++)
646 //k[i][p] and k[i][q]
647 memcpy (&payload[i * 2],
649 sizeof (struct GNUNET_CRYPTO_PaillierCiphertext));
650 memcpy (&payload[i * 2 + 1],
652 sizeof (struct GNUNET_CRYPTO_PaillierCiphertext));
654 if (s->cadet_transmitted_element_count == s->used_element_count)
655 GNUNET_MQ_notify_sent (e,
658 GNUNET_MQ_send (s->cadet->cadet_mq,
660 transmit_bobs_cryptodata_message_multipart (s);
665 * Computes the square sum over a vector of a given length.
667 * @param vector the vector to compute over
668 * @param length the length of the vector
669 * @return an MPI value containing the calculated sum, never NULL
670 * TODO: code duplication with Alice!
673 compute_square_sum (const gcry_mpi_t *vector,
680 GNUNET_assert (NULL != (sum = gcry_mpi_new (0)));
681 GNUNET_assert (NULL != (elem = gcry_mpi_new (0)));
682 for (i = 0; i < length; i++)
684 gcry_mpi_mul (elem, vector[i], vector[i]);
685 gcry_mpi_add (sum, sum, elem);
687 gcry_mpi_release (elem);
694 * (1)[]: $E_A(a_{pi(i)}) otimes E_A(- r_{pi(i)} - b_{pi(i)}) &= E_A(a_{pi(i)} - r_{pi(i)} - b_{pi(i)})$
695 * (2)[]: $E_A(a_{pi'(i)}) otimes E_A(- r_{pi'(i)}) &= E_A(a_{pi'(i)} - r_{pi'(i)})$
696 * S: $S := E_A(sum (r_i + b_i)^2)$
697 * S': $S' := E_A(sum r_i^2)$
699 * @param request the requesting session + bob's requesting peer
702 compute_service_response (struct BobServiceSession *session)
710 const struct MpiElement *b;
711 struct GNUNET_CRYPTO_PaillierCiphertext *a;
712 struct GNUNET_CRYPTO_PaillierCiphertext *r;
713 struct GNUNET_CRYPTO_PaillierCiphertext *r_prime;
715 count = session->used_element_count;
717 b = session->sorted_elements;
718 q = GNUNET_CRYPTO_random_permute (GNUNET_CRYPTO_QUALITY_WEAK,
720 p = GNUNET_CRYPTO_random_permute (GNUNET_CRYPTO_QUALITY_WEAK,
722 rand = GNUNET_malloc (sizeof (gcry_mpi_t) * count);
723 for (i = 0; i < count; i++)
724 GNUNET_assert (NULL != (rand[i] = gcry_mpi_new (0)));
725 r = GNUNET_malloc (sizeof (struct GNUNET_CRYPTO_PaillierCiphertext) * count);
726 r_prime = GNUNET_malloc (sizeof (struct GNUNET_CRYPTO_PaillierCiphertext) * count);
728 for (i = 0; i < count; i++)
732 svalue = (int32_t) GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK,
734 // long to gcry_mpi_t
736 gcry_mpi_sub_ui (rand[i],
740 rand[i] = gcry_mpi_set_ui (rand[i], svalue);
743 tmp = gcry_mpi_new (0);
744 // encrypt the element
745 // for the sake of readability I decided to have dedicated permutation
746 // vectors, which get rid of all the lookups in p/q.
747 // however, ap/aq are not absolutely necessary but are just abstraction
748 // Calculate Kp = E(S + a_pi) (+) E(S - r_pi - b_pi)
749 for (i = 0; i < count; i++)
751 // E(S - r_pi - b_pi)
752 gcry_mpi_sub (tmp, my_offset, rand[p[i]]);
753 gcry_mpi_sub (tmp, tmp, b[p[i]].value);
754 GNUNET_CRYPTO_paillier_encrypt (&session->cadet->remote_pubkey,
759 // E(S - r_pi - b_pi) * E(S + a_pi) == E(2*S + a - r - b)
760 GNUNET_CRYPTO_paillier_hom_add (&session->cadet->remote_pubkey,
766 // Calculate Kq = E(S + a_qi) (+) E(S - r_qi)
767 for (i = 0; i < count; i++)
770 gcry_mpi_sub (tmp, my_offset, rand[q[i]]);
771 GNUNET_assert (2 == GNUNET_CRYPTO_paillier_encrypt (&session->cadet->remote_pubkey,
776 // E(S - r_qi) * E(S + a_qi) == E(2*S + a_qi - r_qi)
777 GNUNET_assert (1 == GNUNET_CRYPTO_paillier_hom_add (&session->cadet->remote_pubkey,
782 gcry_mpi_release (tmp);
784 // Calculate S' = E(SUM( r_i^2 ))
785 tmp = compute_square_sum (rand, count);
786 GNUNET_CRYPTO_paillier_encrypt (&session->cadet->remote_pubkey,
790 gcry_mpi_release (tmp);
792 // Calculate S = E(SUM( (r_i + b_i)^2 ))
793 for (i = 0; i < count; i++)
794 gcry_mpi_add (rand[i], rand[i], b[i].value);
795 tmp = compute_square_sum (rand, count);
796 GNUNET_CRYPTO_paillier_encrypt (&session->cadet->remote_pubkey,
800 gcry_mpi_release (tmp);
803 session->r_prime = r_prime;
805 // release rand, b and a
806 for (i = 0; i < count; i++)
807 gcry_mpi_release (rand[i]);
808 GNUNET_free (session->e_a);
814 // copy the r[], r_prime[], S and Stick into a new message, prepare_service_response frees these
819 * Iterator to copy over messages from the hash map
820 * into an array for sorting.
822 * @param cls the `struct BobServiceSession *`
823 * @param key the key (unused)
824 * @param value the `struct GNUNET_SCALARPRODUCT_Element *`
825 * TODO: code duplication with Alice!
828 copy_element_cb (void *cls,
829 const struct GNUNET_HashCode *key,
832 struct BobServiceSession *s = cls;
833 struct GNUNET_SCALARPRODUCT_Element *e = value;
837 mval = gcry_mpi_new (0);
838 val = (int64_t) GNUNET_ntohll (e->value);
840 gcry_mpi_sub_ui (mval, mval, -val);
842 gcry_mpi_add_ui (mval, mval, val);
843 s->sorted_elements [s->used_element_count].value = mval;
844 s->sorted_elements [s->used_element_count].key = &e->key;
845 s->used_element_count++;
851 * Compare two `struct MpiValue`s by key for sorting.
853 * @param a pointer to first `struct MpiValue *`
854 * @param b pointer to first `struct MpiValue *`
855 * @return -1 for a < b, 0 for a=b, 1 for a > b.
856 * TODO: code duplication with Alice!
859 element_cmp (const void *a,
862 const struct MpiElement *ma = a;
863 const struct MpiElement *mb = b;
865 return GNUNET_CRYPTO_hash_cmp (ma->key,
871 * Intersection operation and receiving data via CADET from
872 * Alice are both done, compute and transmit our reply via
875 * @param s session to transmit reply for.
878 transmit_cryptographic_reply (struct BobServiceSession *s)
880 /* TODO: code duplication with Alice! */
881 LOG (GNUNET_ERROR_TYPE_DEBUG,
882 "Received everything, building reply for Alice\n");
884 = GNUNET_malloc (GNUNET_CONTAINER_multihashmap_size (s->intersected_elements) *
885 sizeof (struct MpiElement));
886 s->used_element_count = 0;
887 GNUNET_CONTAINER_multihashmap_iterate (s->intersected_elements,
890 qsort (s->sorted_elements,
891 s->used_element_count,
892 sizeof (struct MpiElement),
894 compute_service_response (s);
895 transmit_bobs_cryptodata_message (s);
900 * Handle a multipart-chunk of a request from another service to
901 * calculate a scalarproduct with us.
903 * @param cls closure (set from #GNUNET_CADET_connect)
904 * @param channel connection to the other end
905 * @param channel_ctx place to store local state associated with the @a channel
906 * @param message the actual message
907 * @return #GNUNET_OK to keep the connection open,
908 * #GNUNET_SYSERR to close it (signal serious error)
911 handle_alices_cryptodata_message (void *cls,
912 struct GNUNET_CADET_Channel *channel,
914 const struct GNUNET_MessageHeader *message)
916 struct CadetIncomingSession *in = *channel_ctx;
917 struct BobServiceSession *s;
918 const struct AliceCryptodataMessage *msg;
919 const struct GNUNET_CRYPTO_PaillierCiphertext *payload;
920 uint32_t contained_elements;
928 return GNUNET_SYSERR;
934 return GNUNET_SYSERR;
936 msize = ntohs (message->size);
937 if (msize <= sizeof (struct AliceCryptodataMessage))
940 return GNUNET_SYSERR;
942 msg = (const struct AliceCryptodataMessage *) message;
943 contained_elements = ntohl (msg->contained_element_count);
944 /* Our intersection may still be ongoing, but this is nevertheless
945 an upper bound on the required array size */
946 max = GNUNET_CONTAINER_multihashmap_size (s->intersected_elements);
947 msg_length = sizeof (struct AliceCryptodataMessage)
948 + contained_elements * sizeof (struct GNUNET_CRYPTO_PaillierCiphertext);
949 if ( (msize != msg_length) ||
950 (0 == contained_elements) ||
951 (contained_elements > UINT16_MAX) ||
952 (max < contained_elements + s->cadet_received_element_count) )
955 return GNUNET_SYSERR;
957 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
958 "Received %u crypto values from Alice\n",
959 (unsigned int) contained_elements);
961 payload = (const struct GNUNET_CRYPTO_PaillierCiphertext *) &msg[1];
963 s->e_a = GNUNET_malloc (sizeof (struct GNUNET_CRYPTO_PaillierCiphertext) *
965 memcpy (&s->e_a[s->cadet_received_element_count],
967 sizeof (struct GNUNET_CRYPTO_PaillierCiphertext) * contained_elements);
968 s->cadet_received_element_count += contained_elements;
970 if ( (s->cadet_received_element_count == max) &&
971 (NULL == s->intersection_op) )
973 /* intersection has finished also on our side, and
974 we got the full set, so we can proceed with the
976 transmit_cryptographic_reply (s);
978 GNUNET_CADET_receive_done (s->cadet->channel);
984 * Callback for set operation results. Called for each element
985 * that needs to be removed from the result set.
987 * @param cls closure with the `struct BobServiceSession`
988 * @param element a result element, only valid if status is #GNUNET_SET_STATUS_OK
989 * @param status what has happened with the set intersection?
992 cb_intersection_element_removed (void *cls,
993 const struct GNUNET_SET_Element *element,
994 enum GNUNET_SET_Status status)
996 struct BobServiceSession *s = cls;
997 struct GNUNET_SCALARPRODUCT_Element *se;
1001 case GNUNET_SET_STATUS_OK:
1002 /* this element has been removed from the set */
1003 se = GNUNET_CONTAINER_multihashmap_get (s->intersected_elements,
1005 GNUNET_assert (NULL != se);
1006 LOG (GNUNET_ERROR_TYPE_DEBUG,
1007 "Removed element with key %s and value %lld\n",
1008 GNUNET_h2s (&se->key),
1009 (long long) GNUNET_ntohll (se->value));
1010 GNUNET_assert (GNUNET_YES ==
1011 GNUNET_CONTAINER_multihashmap_remove (s->intersected_elements,
1016 case GNUNET_SET_STATUS_DONE:
1017 s->intersection_op = NULL;
1018 GNUNET_break (NULL == s->intersection_set);
1019 GNUNET_CADET_receive_done (s->cadet->channel);
1020 LOG (GNUNET_ERROR_TYPE_DEBUG,
1021 "Finished intersection, %d items remain\n",
1022 GNUNET_CONTAINER_multihashmap_size (s->intersected_elements));
1023 if (s->client_received_element_count ==
1024 GNUNET_CONTAINER_multihashmap_size (s->intersected_elements))
1026 /* CADET transmission from Alice is also already done,
1027 start with our own reply */
1028 transmit_cryptographic_reply (s);
1031 case GNUNET_SET_STATUS_HALF_DONE:
1032 /* unexpected for intersection */
1035 case GNUNET_SET_STATUS_FAILURE:
1036 /* unhandled status code */
1037 LOG (GNUNET_ERROR_TYPE_DEBUG,
1038 "Set intersection failed!\n");
1039 s->intersection_op = NULL;
1040 if (NULL != s->intersection_set)
1042 GNUNET_SET_destroy (s->intersection_set);
1043 s->intersection_set = NULL;
1045 s->status = GNUNET_SCALARPRODUCT_STATUS_FAILURE;
1046 prepare_client_end_notification (s);
1056 * We've paired up a client session with an incoming CADET request.
1057 * Initiate set intersection work.
1059 * @param s client session to start intersection for
1062 start_intersection (struct BobServiceSession *s)
1064 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1065 "Got session with key %s and %u elements, starting intersection.\n",
1066 GNUNET_h2s (&s->session_id),
1067 (unsigned int) s->total);
1070 = GNUNET_SET_prepare (&s->cadet->peer,
1073 GNUNET_SET_RESULT_REMOVED,
1074 &cb_intersection_element_removed,
1077 GNUNET_SET_commit (s->intersection_op,
1078 s->intersection_set))
1081 s->status = GNUNET_SCALARPRODUCT_STATUS_FAILURE;
1082 prepare_client_end_notification (s);
1085 GNUNET_SET_destroy (s->intersection_set);
1086 s->intersection_set = NULL;
1091 * Handle a request from Alice to calculate a scalarproduct with us (Bob).
1093 * @param cls closure (set from #GNUNET_CADET_connect)
1094 * @param channel connection to the other end
1095 * @param channel_ctx place to store the `struct CadetIncomingSession *`
1096 * @param message the actual message
1097 * @return #GNUNET_OK to keep the connection open,
1098 * #GNUNET_SYSERR to close it (signal serious error)
1101 handle_alices_computation_request (void *cls,
1102 struct GNUNET_CADET_Channel *channel,
1104 const struct GNUNET_MessageHeader *message)
1106 struct CadetIncomingSession *in = *channel_ctx;
1107 struct BobServiceSession *s;
1108 const struct ServiceRequestMessage *msg;
1110 if (ntohs (message->size) != sizeof (struct ServiceRequestMessage))
1112 GNUNET_break_op (0);
1113 return GNUNET_SYSERR;
1115 msg = (const struct ServiceRequestMessage *) message;
1116 if (GNUNET_YES == in->in_map)
1118 GNUNET_break_op (0);
1119 return GNUNET_SYSERR;
1121 if (NULL != find_matching_cadet_session (&msg->session_id))
1123 /* not unique, got one like this already */
1124 GNUNET_break_op (0);
1125 return GNUNET_SYSERR;
1127 in->session_id = msg->session_id;
1128 in->remote_pubkey = msg->public_key;
1129 GNUNET_assert (GNUNET_YES ==
1130 GNUNET_CONTAINER_multihashmap_put (cadet_sessions,
1133 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY));
1134 s = find_matching_client_session (&in->session_id);
1137 /* no client waiting for this request, wait for client */
1140 GNUNET_assert (NULL == s->cadet);
1144 if (s->client_received_element_count == s->total)
1145 start_intersection (s);
1151 * Function called for inbound channels on Bob's end. Does some
1152 * preliminary initialization, more happens after we get Alice's first
1155 * @param cls closure
1156 * @param channel new handle to the channel
1157 * @param initiator peer that started the channel
1158 * @param port unused
1159 * @param options unused
1160 * @return session associated with the channel
1163 cb_channel_incoming (void *cls,
1164 struct GNUNET_CADET_Channel *channel,
1165 const struct GNUNET_PeerIdentity *initiator,
1167 enum GNUNET_CADET_ChannelOption options)
1169 struct CadetIncomingSession *in;
1171 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1172 "New incoming channel from peer %s.\n",
1173 GNUNET_i2s (initiator));
1174 in = GNUNET_new (struct CadetIncomingSession);
1175 in->peer = *initiator;
1176 in->channel = channel;
1177 in->cadet_mq = GNUNET_CADET_mq_create (in->channel);
1183 * We're receiving additional set data. Add it to our
1184 * set and if we are done, initiate the transaction.
1186 * @param cls closure
1187 * @param client identification of the client
1188 * @param message the actual message
1191 GSS_handle_bob_client_message_multipart (void *cls,
1192 struct GNUNET_SERVER_Client *client,
1193 const struct GNUNET_MessageHeader *message)
1195 const struct ComputationBobCryptodataMultipartMessage * msg;
1196 struct BobServiceSession *s;
1197 uint32_t contained_count;
1198 const struct GNUNET_SCALARPRODUCT_Element *elements;
1201 struct GNUNET_SET_Element set_elem;
1202 struct GNUNET_SCALARPRODUCT_Element *elem;
1204 s = GNUNET_SERVER_client_get_user_context (client,
1205 struct BobServiceSession);
1208 /* session needs to already exist */
1210 GNUNET_SERVER_receive_done (client,
1214 msize = ntohs (message->size);
1215 if (msize < sizeof (struct ComputationBobCryptodataMultipartMessage))
1218 GNUNET_SERVER_receive_done (client,
1222 msg = (const struct ComputationBobCryptodataMultipartMessage *) message;
1223 contained_count = ntohl (msg->element_count_contained);
1225 if ( (msize != (sizeof (struct ComputationBobCryptodataMultipartMessage) +
1226 contained_count * sizeof (struct GNUNET_SCALARPRODUCT_Element))) ||
1227 (0 == contained_count) ||
1228 (UINT16_MAX < contained_count) ||
1229 (s->total == s->client_received_element_count) ||
1230 (s->total < s->client_received_element_count + contained_count) )
1232 GNUNET_break_op (0);
1233 GNUNET_SERVER_receive_done (client,
1237 elements = (const struct GNUNET_SCALARPRODUCT_Element *) &msg[1];
1238 for (i = 0; i < contained_count; i++)
1240 if (0 == GNUNET_ntohll (elements[i].value))
1242 elem = GNUNET_new (struct GNUNET_SCALARPRODUCT_Element);
1245 sizeof (struct GNUNET_SCALARPRODUCT_Element));
1246 if (GNUNET_SYSERR ==
1247 GNUNET_CONTAINER_multihashmap_put (s->intersected_elements,
1250 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY))
1256 set_elem.data = &elem->key;
1257 set_elem.size = sizeof (elem->key);
1258 set_elem.element_type = 0;
1259 GNUNET_SET_add_element (s->intersection_set,
1263 s->client_received_element_count += contained_count;
1264 GNUNET_SERVER_receive_done (client,
1266 if (s->total != s->client_received_element_count)
1271 if (NULL == s->cadet)
1273 /* no Alice waiting for this request, wait for Alice */
1276 start_intersection (s);
1281 * Handler for Bob's a client request message. Bob is in the response
1282 * role, keep the values + session and waiting for a matching session
1283 * or process a waiting request from Alice.
1285 * @param cls closure
1286 * @param client identification of the client
1287 * @param message the actual message
1290 GSS_handle_bob_client_message (void *cls,
1291 struct GNUNET_SERVER_Client *client,
1292 const struct GNUNET_MessageHeader *message)
1294 const struct BobComputationMessage *msg;
1295 struct BobServiceSession *s;
1296 struct CadetIncomingSession *in;
1297 uint32_t contained_count;
1298 uint32_t total_count;
1299 const struct GNUNET_SCALARPRODUCT_Element *elements;
1301 struct GNUNET_SET_Element set_elem;
1302 struct GNUNET_SCALARPRODUCT_Element *elem;
1305 s = GNUNET_SERVER_client_get_user_context (client,
1306 struct BobServiceSession);
1309 /* only one concurrent session per client connection allowed,
1310 simplifies logic a lot... */
1312 GNUNET_SERVER_receive_done (client,
1316 msize = ntohs (message->size);
1317 if (msize < sizeof (struct BobComputationMessage))
1320 GNUNET_SERVER_receive_done (client,
1324 msg = (const struct BobComputationMessage *) message;
1325 total_count = ntohl (msg->element_count_total);
1326 contained_count = ntohl (msg->element_count_contained);
1327 if ( (0 == total_count) ||
1328 (0 == contained_count) ||
1329 (UINT16_MAX < contained_count) ||
1330 (msize != (sizeof (struct BobComputationMessage) +
1331 contained_count * sizeof (struct GNUNET_SCALARPRODUCT_Element))) )
1333 GNUNET_break_op (0);
1334 GNUNET_SERVER_receive_done (client,
1338 if (NULL != find_matching_client_session (&msg->session_key))
1341 GNUNET_SERVER_receive_done (client,
1346 s = GNUNET_new (struct BobServiceSession);
1347 s->status = GNUNET_SCALARPRODUCT_STATUS_ACTIVE;
1349 s->client_mq = GNUNET_MQ_queue_for_server_client (client);
1350 s->total = total_count;
1351 s->client_received_element_count = contained_count;
1352 s->session_id = msg->session_key;
1353 GNUNET_break (GNUNET_YES ==
1354 GNUNET_CONTAINER_multihashmap_put (client_sessions,
1357 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY));
1358 elements = (const struct GNUNET_SCALARPRODUCT_Element *) &msg[1];
1359 s->intersected_elements = GNUNET_CONTAINER_multihashmap_create (s->total,
1361 s->intersection_set = GNUNET_SET_create (cfg,
1362 GNUNET_SET_OPERATION_INTERSECTION);
1363 for (i = 0; i < contained_count; i++)
1365 if (0 == GNUNET_ntohll (elements[i].value))
1367 elem = GNUNET_new (struct GNUNET_SCALARPRODUCT_Element);
1370 sizeof (struct GNUNET_SCALARPRODUCT_Element));
1371 if (GNUNET_SYSERR ==
1372 GNUNET_CONTAINER_multihashmap_put (s->intersected_elements,
1375 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY))
1381 set_elem.data = &elem->key;
1382 set_elem.size = sizeof (elem->key);
1383 set_elem.element_type = 0;
1384 GNUNET_SET_add_element (s->intersection_set,
1387 s->used_element_count++;
1389 GNUNET_SERVER_client_set_user_context (client,
1391 GNUNET_SERVER_receive_done (client,
1393 if (s->total != s->client_received_element_count)
1398 in = find_matching_cadet_session (&s->session_id);
1401 /* nothing yet, wait for Alice */
1404 GNUNET_assert (NULL == in->s);
1408 start_intersection (s);
1413 * Task run during shutdown.
1419 shutdown_task (void *cls,
1420 const struct GNUNET_SCHEDULER_TaskContext *tc)
1422 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1423 "Shutting down, initiating cleanup.\n");
1424 // FIXME: do we have to cut our connections to CADET first?
1425 if (NULL != my_cadet)
1427 GNUNET_CADET_disconnect (my_cadet);
1430 GNUNET_CONTAINER_multihashmap_destroy (client_sessions);
1431 client_sessions = NULL;
1432 GNUNET_CONTAINER_multihashmap_destroy (cadet_sessions);
1433 cadet_sessions = NULL;
1438 * A client disconnected.
1440 * Remove the associated session(s), release data structures
1441 * and cancel pending outgoing transmissions to the client.
1443 * @param cls closure, NULL
1444 * @param client identification of the client
1447 handle_client_disconnect (void *cls,
1448 struct GNUNET_SERVER_Client *client)
1450 struct BobServiceSession *s;
1454 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1455 "Client disconnected from us.\n",
1457 s = GNUNET_SERVER_client_get_user_context (client,
1458 struct BobServiceSession);
1462 destroy_service_session (s);
1467 * Initialization of the program and message handlers
1469 * @param cls closure
1470 * @param server the initialized server
1471 * @param c configuration to use
1475 struct GNUNET_SERVER_Handle *server,
1476 const struct GNUNET_CONFIGURATION_Handle *c)
1478 static const struct GNUNET_SERVER_MessageHandler server_handlers[] = {
1479 { &GSS_handle_bob_client_message, NULL,
1480 GNUNET_MESSAGE_TYPE_SCALARPRODUCT_CLIENT_TO_BOB,
1482 { &GSS_handle_bob_client_message_multipart, NULL,
1483 GNUNET_MESSAGE_TYPE_SCALARPRODUCT_CLIENT_MUTLIPART_BOB,
1487 static const struct GNUNET_CADET_MessageHandler cadet_handlers[] = {
1488 { &handle_alices_computation_request,
1489 GNUNET_MESSAGE_TYPE_SCALARPRODUCT_SESSION_INITIALIZATION,
1490 sizeof (struct ServiceRequestMessage) },
1491 { &handle_alices_cryptodata_message,
1492 GNUNET_MESSAGE_TYPE_SCALARPRODUCT_ALICE_CRYPTODATA,
1496 static const uint32_t ports[] = {
1497 GNUNET_APPLICATION_TYPE_SCALARPRODUCT,
1503 offset has to be sufficiently small to allow computation of:
1504 m1+m2 mod n == (S + a) + (S + b) mod n,
1505 if we have more complex operations, this factor needs to be lowered */
1506 my_offset = gcry_mpi_new (GNUNET_CRYPTO_PAILLIER_BITS / 3);
1507 gcry_mpi_set_bit (my_offset,
1508 GNUNET_CRYPTO_PAILLIER_BITS / 3);
1510 GNUNET_CRYPTO_paillier_create (&my_pubkey,
1512 GNUNET_SERVER_add_handlers (server,
1514 GNUNET_SERVER_disconnect_notify (server,
1515 &handle_client_disconnect,
1517 client_sessions = GNUNET_CONTAINER_multihashmap_create (128,
1519 cadet_sessions = GNUNET_CONTAINER_multihashmap_create (128,
1521 my_cadet = GNUNET_CADET_connect (cfg, NULL,
1522 &cb_channel_incoming,
1523 &cb_channel_destruction,
1526 if (NULL == my_cadet)
1528 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
1529 _("Connect to CADET failed\n"));
1530 GNUNET_SCHEDULER_shutdown ();
1533 GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_FOREVER_REL,
1540 * The main function for the scalarproduct service.
1542 * @param argc number of arguments from the command line
1543 * @param argv command line arguments
1544 * @return 0 ok, 1 on error
1550 return (GNUNET_OK ==
1551 GNUNET_SERVICE_run (argc, argv,
1552 "scalarproduct-bob",
1553 GNUNET_SERVICE_OPTION_NONE,
1554 &run, NULL)) ? 0 : 1;
1557 /* end of gnunet-service-scalarproduct_bob.c */