2 This file is part of GNUnet.
3 (C) 2013, 2014 Christian Grothoff (and other contributing authors)
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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 * Destroy session state, we are done with it.
313 * @param session the session to free elements from
316 destroy_cadet_session (struct CadetIncomingSession *s);
320 * Destroy session state, we are done with it.
322 * @param session the session to free elements from
325 destroy_service_session (struct BobServiceSession *s)
327 struct CadetIncomingSession *in;
330 if (GNUNET_YES == s->in_destroy)
332 s->in_destroy = GNUNET_YES;
333 if (NULL != (in = s->cadet))
336 destroy_cadet_session (in);
338 if (NULL != s->client_mq)
340 GNUNET_MQ_destroy (s->client_mq);
343 if (NULL != s->client)
345 GNUNET_SERVER_client_disconnect (s->client);
348 GNUNET_assert (GNUNET_YES ==
349 GNUNET_CONTAINER_multihashmap_remove (client_sessions,
352 if (NULL != s->intersected_elements)
354 /* FIXME: free elements */
355 GNUNET_CONTAINER_multihashmap_destroy (s->intersected_elements);
356 s->intersected_elements = NULL;
358 if (NULL != s->intersection_op)
360 GNUNET_SET_operation_cancel (s->intersection_op);
361 s->intersection_op = NULL;
363 if (NULL != s->intersection_set)
365 GNUNET_SET_destroy (s->intersection_set);
366 s->intersection_set = NULL;
370 GNUNET_free (s->e_a);
373 if (NULL != s->sorted_elements)
375 for (i=0;i<s->used_element_count;i++)
376 gcry_mpi_release (s->sorted_elements[i].value);
377 GNUNET_free (s->sorted_elements);
378 s->sorted_elements = NULL;
385 if (NULL != s->r_prime)
387 GNUNET_free (s->r_prime);
390 if (NULL != s->product)
392 gcry_mpi_release (s->product);
400 * Destroy incoming CADET session state, we are done with it.
402 * @param in the session to free elements from
405 destroy_cadet_session (struct CadetIncomingSession *in)
407 struct BobServiceSession *s;
409 if (GNUNET_YES == in->in_destroy)
411 in->in_destroy = GNUNET_YES;
412 if (NULL != (s = in->s))
415 destroy_service_session (s);
417 if (GNUNET_YES == in->in_map)
419 GNUNET_assert (GNUNET_YES ==
420 GNUNET_CONTAINER_multihashmap_remove (cadet_sessions,
423 in->in_map = GNUNET_NO;
425 if (NULL != in->cadet_mq)
427 GNUNET_MQ_destroy (in->cadet_mq);
430 if (NULL != in->channel)
432 GNUNET_CADET_channel_destroy (in->channel);
440 * Notify the client that the session has succeeded or failed. This
441 * message gets sent to Bob's client if the operation completed or
442 * Alice disconnected.
444 * @param session the associated client session to fail or succeed
447 prepare_client_end_notification (struct BobServiceSession *session)
449 struct ClientResponseMessage *msg;
450 struct GNUNET_MQ_Envelope *e;
452 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
453 "Sending session-end notification with status %d to client for session %s\n",
455 GNUNET_h2s (&session->session_id));
456 e = GNUNET_MQ_msg (msg,
457 GNUNET_MESSAGE_TYPE_SCALARPRODUCT_RESULT);
459 msg->product_length = htonl (0);
460 msg->status = htonl (session->status);
461 GNUNET_MQ_send (session->client_mq,
467 * Function called whenever a channel is destroyed. Should clean up
468 * any associated state.
470 * It must NOT call #GNUNET_CADET_channel_destroy() on the channel.
472 * @param cls closure (set from #GNUNET_CADET_connect())
473 * @param channel connection to the other end (henceforth invalid)
474 * @param channel_ctx place where local state associated
475 * with the channel is stored
478 cb_channel_destruction (void *cls,
479 const struct GNUNET_CADET_Channel *channel,
482 struct CadetIncomingSession *in = channel_ctx;
483 struct BobServiceSession *s;
485 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
486 "Peer disconnected, terminating session %s with peer %s\n",
487 GNUNET_h2s (&in->session_id),
488 GNUNET_i2s (&in->peer));
489 if (NULL != in->cadet_mq)
491 GNUNET_MQ_destroy (in->cadet_mq);
495 if (NULL != (s = in->s))
497 if (GNUNET_SCALARPRODUCT_STATUS_ACTIVE == s->status)
499 s->status = GNUNET_SCALARPRODUCT_STATUS_FAILURE;
500 prepare_client_end_notification (s);
503 destroy_cadet_session (in);
508 * MQ finished giving our last message to CADET, now notify
509 * the client that we are finished.
512 bob_cadet_done_cb (void *cls)
514 struct BobServiceSession *session = cls;
516 session->status = GNUNET_SCALARPRODUCT_STATUS_SUCCESS;
517 prepare_client_end_notification (session);
522 * Maximum count of elements we can put into a multipart message
524 #define ELEMENT_CAPACITY ((GNUNET_SERVER_MAX_MESSAGE_SIZE - 1 - sizeof (struct BobCryptodataMultipartMessage)) / sizeof (struct GNUNET_CRYPTO_PaillierCiphertext))
528 * Send a multipart chunk of a service response from Bob to Alice.
529 * This element only contains the two permutations of R, R'.
531 * @param s the associated service session
534 transmit_bobs_cryptodata_message_multipart (struct BobServiceSession *s)
536 struct GNUNET_CRYPTO_PaillierCiphertext *payload;
537 struct BobCryptodataMultipartMessage *msg;
538 struct GNUNET_MQ_Envelope *e;
543 while (s->cadet_transmitted_element_count != s->used_element_count)
545 todo_count = s->used_element_count - s->cadet_transmitted_element_count;
546 if (todo_count > ELEMENT_CAPACITY / 2)
547 todo_count = ELEMENT_CAPACITY / 2;
549 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
550 "Sending %u additional crypto values to Alice\n",
551 (unsigned int) todo_count);
552 e = GNUNET_MQ_msg_extra (msg,
553 todo_count * sizeof (struct GNUNET_CRYPTO_PaillierCiphertext) * 2,
554 GNUNET_MESSAGE_TYPE_SCALARPRODUCT_BOB_CRYPTODATA_MULTIPART);
555 msg->contained_element_count = htonl (todo_count);
556 payload = (struct GNUNET_CRYPTO_PaillierCiphertext *) &msg[1];
557 for (i = s->cadet_transmitted_element_count, j = 0; i < s->cadet_transmitted_element_count + todo_count; i++)
559 //r[i][p] and r[i][q]
560 memcpy (&payload[j++],
562 sizeof (struct GNUNET_CRYPTO_PaillierCiphertext));
563 memcpy (&payload[j++],
565 sizeof (struct GNUNET_CRYPTO_PaillierCiphertext));
567 s->cadet_transmitted_element_count += todo_count;
568 if (s->cadet_transmitted_element_count == s->used_element_count)
569 GNUNET_MQ_notify_sent (e,
572 GNUNET_MQ_send (s->cadet->cadet_mq,
579 * Bob generates the response message to be sent to Alice after
580 * computing the values (1), (2), S and S'.
582 * (1)[]: $E_A(a_{pi(i)}) times E_A(- r_{pi(i)} - b_{pi(i)}) &= E_A(a_{pi(i)} - r_{pi(i)} - b_{pi(i)})$
583 * (2)[]: $E_A(a_{pi'(i)}) times E_A(- r_{pi'(i)}) &= E_A(a_{pi'(i)} - r_{pi'(i)})$
584 * S: $S := E_A(sum (r_i + b_i)^2)$
585 * S': $S' := E_A(sum r_i^2)$
587 * @param s the associated requesting session with Alice
590 transmit_bobs_cryptodata_message (struct BobServiceSession *s)
592 struct BobCryptodataMessage *msg;
593 struct GNUNET_MQ_Envelope *e;
594 struct GNUNET_CRYPTO_PaillierCiphertext *payload;
597 s->cadet_transmitted_element_count = (GNUNET_SERVER_MAX_MESSAGE_SIZE - 1 - sizeof (struct BobCryptodataMessage)) /
598 (sizeof (struct GNUNET_CRYPTO_PaillierCiphertext) * 2) - 2;
599 if (s->cadet_transmitted_element_count > s->used_element_count)
600 s->cadet_transmitted_element_count = s->used_element_count;
602 e = GNUNET_MQ_msg_extra (msg,
603 (2 + s->cadet_transmitted_element_count * 2)
604 * sizeof (struct GNUNET_CRYPTO_PaillierCiphertext),
605 GNUNET_MESSAGE_TYPE_SCALARPRODUCT_BOB_CRYPTODATA);
606 msg->contained_element_count = htonl (s->cadet_transmitted_element_count);
608 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
609 "Sending %u/%u crypto values to Alice\n",
610 (unsigned int) s->cadet_transmitted_element_count,
611 (unsigned int) s->used_element_count);
613 payload = (struct GNUNET_CRYPTO_PaillierCiphertext *) &msg[1];
616 sizeof (struct GNUNET_CRYPTO_PaillierCiphertext));
619 sizeof (struct GNUNET_CRYPTO_PaillierCiphertext));
621 payload = &payload[2];
623 for (i = 0; i < s->cadet_transmitted_element_count; i++)
625 //k[i][p] and k[i][q]
626 memcpy (&payload[i * 2],
628 sizeof (struct GNUNET_CRYPTO_PaillierCiphertext));
629 memcpy (&payload[i * 2 + 1],
631 sizeof (struct GNUNET_CRYPTO_PaillierCiphertext));
633 if (s->cadet_transmitted_element_count == s->used_element_count)
634 GNUNET_MQ_notify_sent (e,
637 GNUNET_MQ_send (s->cadet->cadet_mq,
639 transmit_bobs_cryptodata_message_multipart (s);
644 * Computes the square sum over a vector of a given length.
646 * @param vector the vector to compute over
647 * @param length the length of the vector
648 * @return an MPI value containing the calculated sum, never NULL
649 * TODO: code duplication with Alice!
652 compute_square_sum (const gcry_mpi_t *vector,
659 GNUNET_assert (NULL != (sum = gcry_mpi_new (0)));
660 GNUNET_assert (NULL != (elem = gcry_mpi_new (0)));
661 for (i = 0; i < length; i++)
663 gcry_mpi_mul (elem, vector[i], vector[i]);
664 gcry_mpi_add (sum, sum, elem);
666 gcry_mpi_release (elem);
673 * (1)[]: $E_A(a_{pi(i)}) otimes E_A(- r_{pi(i)} - b_{pi(i)}) &= E_A(a_{pi(i)} - r_{pi(i)} - b_{pi(i)})$
674 * (2)[]: $E_A(a_{pi'(i)}) otimes E_A(- r_{pi'(i)}) &= E_A(a_{pi'(i)} - r_{pi'(i)})$
675 * S: $S := E_A(sum (r_i + b_i)^2)$
676 * S': $S' := E_A(sum r_i^2)$
678 * @param request the requesting session + bob's requesting peer
681 compute_service_response (struct BobServiceSession *session)
689 const struct MpiElement *b;
690 struct GNUNET_CRYPTO_PaillierCiphertext *a;
691 struct GNUNET_CRYPTO_PaillierCiphertext *r;
692 struct GNUNET_CRYPTO_PaillierCiphertext *r_prime;
694 count = session->used_element_count;
696 b = session->sorted_elements;
697 q = GNUNET_CRYPTO_random_permute (GNUNET_CRYPTO_QUALITY_WEAK,
699 p = GNUNET_CRYPTO_random_permute (GNUNET_CRYPTO_QUALITY_WEAK,
701 rand = GNUNET_malloc (sizeof (gcry_mpi_t) * count);
702 for (i = 0; i < count; i++)
703 GNUNET_assert (NULL != (rand[i] = gcry_mpi_new (0)));
704 r = GNUNET_malloc (sizeof (struct GNUNET_CRYPTO_PaillierCiphertext) * count);
705 r_prime = GNUNET_malloc (sizeof (struct GNUNET_CRYPTO_PaillierCiphertext) * count);
707 for (i = 0; i < count; i++)
711 svalue = (int32_t) GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK,
713 // long to gcry_mpi_t
715 gcry_mpi_sub_ui (rand[i],
719 rand[i] = gcry_mpi_set_ui (rand[i], svalue);
722 tmp = gcry_mpi_new (0);
723 // encrypt the element
724 // for the sake of readability I decided to have dedicated permutation
725 // vectors, which get rid of all the lookups in p/q.
726 // however, ap/aq are not absolutely necessary but are just abstraction
727 // Calculate Kp = E(S + a_pi) (+) E(S - r_pi - b_pi)
728 for (i = 0; i < count; i++)
730 // E(S - r_pi - b_pi)
731 gcry_mpi_sub (tmp, my_offset, rand[p[i]]);
732 gcry_mpi_sub (tmp, tmp, b[p[i]].value);
733 GNUNET_CRYPTO_paillier_encrypt (&session->cadet->remote_pubkey,
738 // E(S - r_pi - b_pi) * E(S + a_pi) == E(2*S + a - r - b)
739 GNUNET_CRYPTO_paillier_hom_add (&session->cadet->remote_pubkey,
745 // Calculate Kq = E(S + a_qi) (+) E(S - r_qi)
746 for (i = 0; i < count; i++)
749 gcry_mpi_sub (tmp, my_offset, rand[q[i]]);
750 GNUNET_assert (2 == GNUNET_CRYPTO_paillier_encrypt (&session->cadet->remote_pubkey,
755 // E(S - r_qi) * E(S + a_qi) == E(2*S + a_qi - r_qi)
756 GNUNET_assert (1 == GNUNET_CRYPTO_paillier_hom_add (&session->cadet->remote_pubkey,
762 // Calculate S' = E(SUM( r_i^2 ))
763 tmp = compute_square_sum (rand, count);
764 GNUNET_CRYPTO_paillier_encrypt (&session->cadet->remote_pubkey,
769 // Calculate S = E(SUM( (r_i + b_i)^2 ))
770 for (i = 0; i < count; i++)
771 gcry_mpi_add (rand[i], rand[i], b[i].value);
772 tmp = compute_square_sum (rand, count);
773 GNUNET_CRYPTO_paillier_encrypt (&session->cadet->remote_pubkey,
779 session->r_prime = r_prime;
781 // release rand, b and a
782 for (i = 0; i < count; i++)
783 gcry_mpi_release (rand[i]);
784 gcry_mpi_release (tmp);
785 GNUNET_free (session->e_a);
791 // copy the r[], r_prime[], S and Stick into a new message, prepare_service_response frees these
796 * Iterator to copy over messages from the hash map
797 * into an array for sorting.
799 * @param cls the `struct BobServiceSession *`
800 * @param key the key (unused)
801 * @param value the `struct GNUNET_SCALARPRODUCT_Element *`
802 * TODO: code duplication with Alice!
805 copy_element_cb (void *cls,
806 const struct GNUNET_HashCode *key,
809 struct BobServiceSession *s = cls;
810 struct GNUNET_SCALARPRODUCT_Element *e = value;
814 mval = gcry_mpi_new (0);
815 val = (int64_t) GNUNET_ntohll (e->value);
817 gcry_mpi_sub_ui (mval, mval, -val);
819 gcry_mpi_add_ui (mval, mval, val);
820 s->sorted_elements [s->used_element_count].value = mval;
821 s->sorted_elements [s->used_element_count].key = &e->key;
822 s->used_element_count++;
828 * Compare two `struct MpiValue`s by key for sorting.
830 * @param a pointer to first `struct MpiValue *`
831 * @param b pointer to first `struct MpiValue *`
832 * @return -1 for a < b, 0 for a=b, 1 for a > b.
833 * TODO: code duplication with Alice!
836 element_cmp (const void *a,
839 const struct MpiElement *ma = a;
840 const struct MpiElement *mb = b;
842 return GNUNET_CRYPTO_hash_cmp (ma->key,
848 * Intersection operation and receiving data via CADET from
849 * Alice are both done, compute and transmit our reply via
852 * @param s session to transmit reply for.
855 transmit_cryptographic_reply (struct BobServiceSession *s)
857 /* TODO: code duplication with Alice! */
858 LOG (GNUNET_ERROR_TYPE_DEBUG,
859 "Received everything, building reply for Alice\n");
861 = GNUNET_malloc (GNUNET_CONTAINER_multihashmap_size (s->intersected_elements) *
862 sizeof (struct MpiElement));
863 s->used_element_count = 0;
864 GNUNET_CONTAINER_multihashmap_iterate (s->intersected_elements,
867 qsort (s->sorted_elements,
868 s->used_element_count,
869 sizeof (struct MpiElement),
871 compute_service_response (s);
872 transmit_bobs_cryptodata_message (s);
877 * Handle a multipart-chunk of a request from another service to
878 * calculate a scalarproduct with us.
880 * @param cls closure (set from #GNUNET_CADET_connect)
881 * @param channel connection to the other end
882 * @param channel_ctx place to store local state associated with the @a channel
883 * @param message the actual message
884 * @return #GNUNET_OK to keep the connection open,
885 * #GNUNET_SYSERR to close it (signal serious error)
888 handle_alices_cryptodata_message (void *cls,
889 struct GNUNET_CADET_Channel *channel,
891 const struct GNUNET_MessageHeader *message)
893 struct CadetIncomingSession *in = *channel_ctx;
894 struct BobServiceSession *s;
895 const struct AliceCryptodataMessage *msg;
896 const struct GNUNET_CRYPTO_PaillierCiphertext *payload;
897 uint32_t contained_elements;
905 return GNUNET_SYSERR;
911 return GNUNET_SYSERR;
913 msize = ntohs (message->size);
914 if (msize <= sizeof (struct AliceCryptodataMessage))
917 return GNUNET_SYSERR;
919 msg = (const struct AliceCryptodataMessage *) message;
920 contained_elements = ntohl (msg->contained_element_count);
921 /* Our intersection may still be ongoing, but this is nevertheless
922 an upper bound on the required array size */
923 max = GNUNET_CONTAINER_multihashmap_size (s->intersected_elements);
924 msg_length = sizeof (struct AliceCryptodataMessage)
925 + contained_elements * sizeof (struct GNUNET_CRYPTO_PaillierCiphertext);
926 if ( (msize != msg_length) ||
927 (0 == contained_elements) ||
928 (contained_elements > UINT16_MAX) ||
929 (max < contained_elements + s->cadet_received_element_count) )
932 return GNUNET_SYSERR;
934 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
935 "Received %u crypto values from Alice\n",
936 (unsigned int) contained_elements);
938 payload = (const struct GNUNET_CRYPTO_PaillierCiphertext *) &msg[1];
940 s->e_a = GNUNET_malloc (sizeof (struct GNUNET_CRYPTO_PaillierCiphertext) *
942 memcpy (&s->e_a[s->cadet_received_element_count],
944 sizeof (struct GNUNET_CRYPTO_PaillierCiphertext) * contained_elements);
945 s->cadet_received_element_count += contained_elements;
947 if ( (s->cadet_received_element_count == max) &&
948 (NULL == s->intersection_op) )
950 /* intersection has finished also on our side, and
951 we got the full set, so we can proceed with the
953 transmit_cryptographic_reply (s);
955 GNUNET_CADET_receive_done (s->cadet->channel);
961 * Callback for set operation results. Called for each element
962 * that needs to be removed from the result set.
964 * @param cls closure with the `struct BobServiceSession`
965 * @param element a result element, only valid if status is #GNUNET_SET_STATUS_OK
966 * @param status what has happened with the set intersection?
969 cb_intersection_element_removed (void *cls,
970 const struct GNUNET_SET_Element *element,
971 enum GNUNET_SET_Status status)
973 struct BobServiceSession *s = cls;
974 struct GNUNET_SCALARPRODUCT_Element *se;
978 case GNUNET_SET_STATUS_OK:
979 /* this element has been removed from the set */
980 se = GNUNET_CONTAINER_multihashmap_get (s->intersected_elements,
982 GNUNET_assert (NULL != se);
983 LOG (GNUNET_ERROR_TYPE_DEBUG,
984 "Removed element with key %s and value %lld\n",
985 GNUNET_h2s (&se->key),
986 (long long) GNUNET_ntohll (se->value));
987 GNUNET_assert (GNUNET_YES ==
988 GNUNET_CONTAINER_multihashmap_remove (s->intersected_elements,
993 case GNUNET_SET_STATUS_DONE:
994 s->intersection_op = NULL;
995 s->intersection_set = NULL;
996 GNUNET_CADET_receive_done (s->cadet->channel);
997 LOG (GNUNET_ERROR_TYPE_DEBUG,
998 "Finished intersection, %d items remain\n",
999 GNUNET_CONTAINER_multihashmap_size (s->intersected_elements));
1000 if (s->client_received_element_count ==
1001 GNUNET_CONTAINER_multihashmap_size (s->intersected_elements))
1003 /* CADET transmission from Alice is also already done,
1004 start with our own reply */
1005 transmit_cryptographic_reply (s);
1008 case GNUNET_SET_STATUS_HALF_DONE:
1009 /* unexpected for intersection */
1012 case GNUNET_SET_STATUS_FAILURE:
1013 /* unhandled status code */
1014 LOG (GNUNET_ERROR_TYPE_DEBUG,
1015 "Set intersection failed!\n");
1016 s->intersection_op = NULL;
1017 s->intersection_set = NULL;
1018 s->status = GNUNET_SCALARPRODUCT_STATUS_FAILURE;
1019 prepare_client_end_notification (s);
1029 * We've paired up a client session with an incoming CADET request.
1030 * Initiate set intersection work.
1032 * @param s client session to start intersection for
1035 start_intersection (struct BobServiceSession *s)
1037 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1038 "Got session with key %s and %u elements, starting intersection.\n",
1039 GNUNET_h2s (&s->session_id),
1040 (unsigned int) s->total);
1043 = GNUNET_SET_prepare (&s->cadet->peer,
1046 GNUNET_SET_RESULT_REMOVED,
1047 &cb_intersection_element_removed,
1049 GNUNET_SET_commit (s->intersection_op,
1050 s->intersection_set);
1055 * Handle a request from Alice to calculate a scalarproduct with us (Bob).
1057 * @param cls closure (set from #GNUNET_CADET_connect)
1058 * @param channel connection to the other end
1059 * @param channel_ctx place to store the `struct CadetIncomingSession *`
1060 * @param message the actual message
1061 * @return #GNUNET_OK to keep the connection open,
1062 * #GNUNET_SYSERR to close it (signal serious error)
1065 handle_alices_computation_request (void *cls,
1066 struct GNUNET_CADET_Channel *channel,
1068 const struct GNUNET_MessageHeader *message)
1070 struct CadetIncomingSession *in = *channel_ctx;
1071 struct BobServiceSession *s;
1072 const struct ServiceRequestMessage *msg;
1074 if (ntohs (message->size) != sizeof (struct ServiceRequestMessage))
1076 GNUNET_break_op (0);
1077 return GNUNET_SYSERR;
1079 msg = (const struct ServiceRequestMessage *) message;
1080 if (GNUNET_YES == in->in_map)
1082 GNUNET_break_op (0);
1083 return GNUNET_SYSERR;
1085 if (NULL != find_matching_cadet_session (&msg->session_id))
1087 /* not unique, got one like this already */
1088 GNUNET_break_op (0);
1089 return GNUNET_SYSERR;
1091 in->session_id = msg->session_id;
1092 in->remote_pubkey = msg->public_key;
1093 GNUNET_assert (GNUNET_YES ==
1094 GNUNET_CONTAINER_multihashmap_put (cadet_sessions,
1097 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY));
1098 s = find_matching_client_session (&in->session_id);
1101 /* no client waiting for this request, wait for client */
1104 GNUNET_assert (NULL == s->cadet);
1108 if (s->client_received_element_count == s->total)
1109 start_intersection (s);
1115 * Function called for inbound channels on Bob's end. Does some
1116 * preliminary initialization, more happens after we get Alice's first
1119 * @param cls closure
1120 * @param channel new handle to the channel
1121 * @param initiator peer that started the channel
1122 * @param port unused
1123 * @param options unused
1124 * @return session associated with the channel
1127 cb_channel_incoming (void *cls,
1128 struct GNUNET_CADET_Channel *channel,
1129 const struct GNUNET_PeerIdentity *initiator,
1131 enum GNUNET_CADET_ChannelOption options)
1133 struct CadetIncomingSession *in;
1135 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1136 "New incoming channel from peer %s.\n",
1137 GNUNET_i2s (initiator));
1138 in = GNUNET_new (struct CadetIncomingSession);
1139 in->peer = *initiator;
1140 in->channel = channel;
1146 * We're receiving additional set data. Add it to our
1147 * set and if we are done, initiate the transaction.
1149 * @param cls closure
1150 * @param client identification of the client
1151 * @param message the actual message
1154 GSS_handle_bob_client_message_multipart (void *cls,
1155 struct GNUNET_SERVER_Client *client,
1156 const struct GNUNET_MessageHeader *message)
1158 const struct ComputationBobCryptodataMultipartMessage * msg;
1159 struct BobServiceSession *s;
1160 uint32_t contained_count;
1161 const struct GNUNET_SCALARPRODUCT_Element *elements;
1164 struct GNUNET_SET_Element set_elem;
1165 struct GNUNET_SCALARPRODUCT_Element *elem;
1167 s = GNUNET_SERVER_client_get_user_context (client,
1168 struct BobServiceSession);
1171 /* session needs to already exist */
1173 GNUNET_SERVER_receive_done (client,
1177 msize = ntohs (message->size);
1178 if (msize < sizeof (struct ComputationBobCryptodataMultipartMessage))
1181 GNUNET_SERVER_receive_done (client,
1185 msg = (const struct ComputationBobCryptodataMultipartMessage *) message;
1186 contained_count = ntohl (msg->element_count_contained);
1188 if ( (msize != (sizeof (struct ComputationBobCryptodataMultipartMessage) +
1189 contained_count * sizeof (struct GNUNET_SCALARPRODUCT_Element))) ||
1190 (0 == contained_count) ||
1191 (UINT16_MAX < contained_count) ||
1192 (s->total == s->client_received_element_count) ||
1193 (s->total < s->client_received_element_count + contained_count) )
1195 GNUNET_break_op (0);
1196 GNUNET_SERVER_receive_done (client,
1200 elements = (const struct GNUNET_SCALARPRODUCT_Element *) &msg[1];
1201 for (i = 0; i < contained_count; i++)
1203 if (0 == GNUNET_ntohll (elements[i].value))
1205 elem = GNUNET_new (struct GNUNET_SCALARPRODUCT_Element);
1208 sizeof (struct GNUNET_SCALARPRODUCT_Element));
1209 if (GNUNET_SYSERR ==
1210 GNUNET_CONTAINER_multihashmap_put (s->intersected_elements,
1213 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY))
1219 set_elem.data = &elem->key;
1220 set_elem.size = sizeof (elem->key);
1221 set_elem.element_type = 0;
1222 GNUNET_SET_add_element (s->intersection_set,
1226 s->client_received_element_count += contained_count;
1227 GNUNET_SERVER_receive_done (client,
1229 if (s->total != s->client_received_element_count)
1234 if (NULL == s->cadet)
1236 /* no Alice waiting for this request, wait for Alice */
1239 start_intersection (s);
1244 * Handler for Bob's a client request message. Bob is in the response
1245 * role, keep the values + session and waiting for a matching session
1246 * or process a waiting request from Alice.
1248 * @param cls closure
1249 * @param client identification of the client
1250 * @param message the actual message
1253 GSS_handle_bob_client_message (void *cls,
1254 struct GNUNET_SERVER_Client *client,
1255 const struct GNUNET_MessageHeader *message)
1257 const struct BobComputationMessage *msg;
1258 struct BobServiceSession *s;
1259 struct CadetIncomingSession *in;
1260 uint32_t contained_count;
1261 uint32_t total_count;
1262 const struct GNUNET_SCALARPRODUCT_Element *elements;
1264 struct GNUNET_SET_Element set_elem;
1265 struct GNUNET_SCALARPRODUCT_Element *elem;
1268 s = GNUNET_SERVER_client_get_user_context (client,
1269 struct BobServiceSession);
1272 /* only one concurrent session per client connection allowed,
1273 simplifies logic a lot... */
1275 GNUNET_SERVER_receive_done (client,
1279 msize = ntohs (message->size);
1280 if (msize < sizeof (struct BobComputationMessage))
1283 GNUNET_SERVER_receive_done (client,
1287 msg = (const struct BobComputationMessage *) message;
1288 total_count = ntohl (msg->element_count_total);
1289 contained_count = ntohl (msg->element_count_contained);
1290 if ( (0 == total_count) ||
1291 (0 == contained_count) ||
1292 (UINT16_MAX < contained_count) ||
1293 (msize != (sizeof (struct BobComputationMessage) +
1294 contained_count * sizeof (struct GNUNET_SCALARPRODUCT_Element))) )
1296 GNUNET_break_op (0);
1297 GNUNET_SERVER_receive_done (client,
1301 if (NULL != find_matching_client_session (&msg->session_key))
1304 GNUNET_SERVER_receive_done (client,
1309 s = GNUNET_new (struct BobServiceSession);
1310 s->status = GNUNET_SCALARPRODUCT_STATUS_ACTIVE;
1312 s->client_mq = GNUNET_MQ_queue_for_server_client (client);
1313 s->total = total_count;
1314 s->client_received_element_count = contained_count;
1315 s->session_id = msg->session_key;
1316 GNUNET_break (GNUNET_YES ==
1317 GNUNET_CONTAINER_multihashmap_put (client_sessions,
1320 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY));
1321 elements = (const struct GNUNET_SCALARPRODUCT_Element *) &msg[1];
1322 s->intersected_elements = GNUNET_CONTAINER_multihashmap_create (s->total,
1324 s->intersection_set = GNUNET_SET_create (cfg,
1325 GNUNET_SET_OPERATION_INTERSECTION);
1326 for (i = 0; i < contained_count; i++)
1328 if (0 == GNUNET_ntohll (elements[i].value))
1330 elem = GNUNET_new (struct GNUNET_SCALARPRODUCT_Element);
1333 sizeof (struct GNUNET_SCALARPRODUCT_Element));
1334 if (GNUNET_SYSERR ==
1335 GNUNET_CONTAINER_multihashmap_put (s->intersected_elements,
1338 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY))
1344 set_elem.data = &elem->key;
1345 set_elem.size = sizeof (elem->key);
1346 set_elem.element_type = 0;
1347 GNUNET_SET_add_element (s->intersection_set,
1350 s->used_element_count++;
1352 GNUNET_SERVER_client_set_user_context (client,
1354 GNUNET_SERVER_receive_done (client,
1356 if (s->total != s->client_received_element_count)
1361 in = find_matching_cadet_session (&s->session_id);
1364 /* nothing yet, wait for Alice */
1367 GNUNET_assert (NULL == in->s);
1371 start_intersection (s);
1376 * Task run during shutdown.
1382 shutdown_task (void *cls,
1383 const struct GNUNET_SCHEDULER_TaskContext *tc)
1385 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1386 "Shutting down, initiating cleanup.\n");
1387 // FIXME: do we have to cut our connections to CADET first?
1388 if (NULL != my_cadet)
1390 GNUNET_CADET_disconnect (my_cadet);
1393 GNUNET_CONTAINER_multihashmap_destroy (client_sessions);
1394 client_sessions = NULL;
1395 GNUNET_CONTAINER_multihashmap_destroy (cadet_sessions);
1396 cadet_sessions = NULL;
1401 * A client disconnected.
1403 * Remove the associated session(s), release data structures
1404 * and cancel pending outgoing transmissions to the client.
1406 * @param cls closure, NULL
1407 * @param client identification of the client
1410 handle_client_disconnect (void *cls,
1411 struct GNUNET_SERVER_Client *client)
1413 struct BobServiceSession *s;
1417 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1418 "Client disconnected from us.\n",
1420 s = GNUNET_SERVER_client_get_user_context (client,
1421 struct BobServiceSession);
1425 destroy_service_session (s);
1430 * Initialization of the program and message handlers
1432 * @param cls closure
1433 * @param server the initialized server
1434 * @param c configuration to use
1438 struct GNUNET_SERVER_Handle *server,
1439 const struct GNUNET_CONFIGURATION_Handle *c)
1441 static const struct GNUNET_SERVER_MessageHandler server_handlers[] = {
1442 { &GSS_handle_bob_client_message, NULL,
1443 GNUNET_MESSAGE_TYPE_SCALARPRODUCT_CLIENT_TO_BOB,
1445 { &GSS_handle_bob_client_message_multipart, NULL,
1446 GNUNET_MESSAGE_TYPE_SCALARPRODUCT_CLIENT_MUTLIPART_BOB,
1450 static const struct GNUNET_CADET_MessageHandler cadet_handlers[] = {
1451 { &handle_alices_computation_request,
1452 GNUNET_MESSAGE_TYPE_SCALARPRODUCT_SESSION_INITIALIZATION,
1453 sizeof (struct ServiceRequestMessage) },
1454 { &handle_alices_cryptodata_message,
1455 GNUNET_MESSAGE_TYPE_SCALARPRODUCT_ALICE_CRYPTODATA,
1459 static const uint32_t ports[] = {
1460 GNUNET_APPLICATION_TYPE_SCALARPRODUCT,
1466 offset has to be sufficiently small to allow computation of:
1467 m1+m2 mod n == (S + a) + (S + b) mod n,
1468 if we have more complex operations, this factor needs to be lowered */
1469 my_offset = gcry_mpi_new (GNUNET_CRYPTO_PAILLIER_BITS / 3);
1470 gcry_mpi_set_bit (my_offset,
1471 GNUNET_CRYPTO_PAILLIER_BITS / 3);
1473 GNUNET_CRYPTO_paillier_create (&my_pubkey,
1475 GNUNET_SERVER_add_handlers (server,
1477 GNUNET_SERVER_disconnect_notify (server,
1478 &handle_client_disconnect,
1480 client_sessions = GNUNET_CONTAINER_multihashmap_create (128,
1482 cadet_sessions = GNUNET_CONTAINER_multihashmap_create (128,
1484 my_cadet = GNUNET_CADET_connect (cfg, NULL,
1485 &cb_channel_incoming,
1486 &cb_channel_destruction,
1489 if (NULL == my_cadet)
1491 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
1492 _("Connect to CADET failed\n"));
1493 GNUNET_SCHEDULER_shutdown ();
1496 GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_FOREVER_REL,
1503 * The main function for the scalarproduct service.
1505 * @param argc number of arguments from the command line
1506 * @param argv command line arguments
1507 * @return 0 ok, 1 on error
1513 return (GNUNET_OK ==
1514 GNUNET_SERVICE_run (argc, argv,
1515 "scalarproduct-bob",
1516 GNUNET_SERVICE_OPTION_NONE,
1517 &run, NULL)) ? 0 : 1;
1520 /* end of gnunet-service-scalarproduct_bob.c */