/* This file is part of GNUnet. (C) 2013, 2014 Christian Grothoff (and other contributing authors) GNUnet is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3, or (at your option) any later version. GNUnet is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with GNUnet; see the file COPYING. If not, write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ /** * @file scalarproduct/gnunet-service-scalarproduct.c * @brief scalarproduct service implementation * @author Christian M. Fuchs * @author Christian Grothoff */ #include "platform.h" #include #include #include "gnunet_util_lib.h" #include "gnunet_core_service.h" #include "gnunet_cadet_service.h" #include "gnunet_applications.h" #include "gnunet_protocols.h" #include "gnunet_scalarproduct_service.h" #include "gnunet_set_service.h" #include "scalarproduct.h" #define LOG(kind,...) GNUNET_log_from (kind, "scalarproduct", __VA_ARGS__) /** * Maximum count of elements we can put into a multipart message */ #define MULTIPART_ELEMENT_CAPACITY ((GNUNET_SERVER_MAX_MESSAGE_SIZE - 1 - sizeof (struct MultipartMessage)) / sizeof (struct GNUNET_CRYPTO_PaillierCiphertext)) GNUNET_NETWORK_STRUCT_BEGIN /** * Message type passed from requesting service Alice to responding * service Bob to initiate a request and make Bob participate in our * protocol */ struct ServiceRequestMessage { /** * GNUNET message header */ struct GNUNET_MessageHeader header; /** * the transaction/session key used to identify a session */ struct GNUNET_HashCode session_id; /** * Alice's public key */ struct GNUNET_CRYPTO_PaillierPublicKey public_key; }; /** * FIXME. */ struct AliceCryptodataMessage { /** * GNUNET message header */ struct GNUNET_MessageHeader header; /** * how many elements we appended to this message */ uint32_t contained_element_count GNUNET_PACKED; /** * struct GNUNET_CRYPTO_PaillierCiphertext[contained_element_count] */ }; /** * Multipart Message type passed between to supply additional elements * for the peer */ struct MultipartMessage { /** * GNUNET message header */ struct GNUNET_MessageHeader header; /** * how many elements we supply within this message */ uint32_t contained_element_count GNUNET_PACKED; // struct GNUNET_CRYPTO_PaillierCiphertext[multipart_element_count] }; /** * Message type passed from responding service Bob to responding service Alice * to complete a request and allow Alice to compute the result */ struct ServiceResponseMessage { /** * GNUNET message header */ struct GNUNET_MessageHeader header; /** * how many elements the session input had */ uint32_t total_element_count GNUNET_PACKED; /** * how many elements were included after the mask was applied * including all multipart msgs. */ uint32_t used_element_count GNUNET_PACKED; /** * how many elements this individual message delivers */ uint32_t contained_element_count GNUNET_PACKED; /** * the transaction/session key used to identify a session */ struct GNUNET_HashCode key; /** * followed by s | s' | k[i][perm] */ }; GNUNET_NETWORK_STRUCT_END /** * role a peer in a session can assume */ enum PeerRole { ALICE, BOB }; /** * DLL for sorting elements */ struct SortedValue { /** * Sorted Values are kept in a DLL */ struct SortedValue * next; /** * Sorted Values are kept in a DLL */ struct SortedValue * prev; /** * The element's id+integer-value */ struct GNUNET_SCALARPRODUCT_Element * elem; /** * the element's value converted to MPI */ gcry_mpi_t val; }; /** * A scalarproduct session which tracks: * * a request form the client to our final response. * or * a request from a service to us(service). */ struct ServiceSession { /** * Is this session active (#GNUNET_YES), Concluded (#GNUNET_NO), or had an error (#GNUNET_SYSERR) */ int32_t active; /** * the role this peer has */ enum PeerRole role; /** * session information is kept in a DLL */ struct ServiceSession *next; /** * session information is kept in a DLL */ struct ServiceSession *prev; /** * (hopefully) unique transaction ID */ struct GNUNET_HashCode session_id; /** * Alice or Bob's peerID */ struct GNUNET_PeerIdentity peer; /** * the client this request is related to */ struct GNUNET_SERVER_Client *client; /** * The message to send */ struct GNUNET_MessageHeader *msg; /** * how many elements we were supplied with from the client */ uint32_t total; /** * all non-0-value'd elements transmitted to us */ struct GNUNET_CONTAINER_MultiHashMap *intersected_elements; /** * how many elements actually are used for the scalar product */ uint32_t used_element_count; /** * already transferred elements (sent/received) for multipart messages, less or equal than @e used_element_count for */ uint32_t transferred_element_count; /** * Set of elements for which will conduction an intersection. * the resulting elements are then used for computing the scalar product. */ struct GNUNET_SET_Handle *intersection_set; /** * Set of elements for which will conduction an intersection. * the resulting elements are then used for computing the scalar product. */ struct GNUNET_SET_OperationHandle *intersection_op; /** * Handle to Alice's Intersection operation listening for Bob */ struct GNUNET_SET_ListenHandle *intersection_listen; /** * Public key of the remote service, only used by Bob */ struct GNUNET_CRYPTO_PaillierPublicKey *remote_pubkey; /** * DLL for sorting elements after intersection */ struct SortedValue *a_head; /** * a(Alice) */ struct SortedValue *a_tail; /** * a(Alice) */ gcry_mpi_t *sorted_elements; /** * E(ai)(Bob) after applying the mask */ struct GNUNET_CRYPTO_PaillierCiphertext *e_a; /** * Bob's permutation p of R */ struct GNUNET_CRYPTO_PaillierCiphertext *r; /** * Bob's permutation q of R */ struct GNUNET_CRYPTO_PaillierCiphertext *r_prime; /** * Bob's s */ struct GNUNET_CRYPTO_PaillierCiphertext *s; /** * Bob's s' */ struct GNUNET_CRYPTO_PaillierCiphertext *s_prime; /** * Bob's matching response session from the client */ struct ServiceSession *response; /** * The computed scalar */ gcry_mpi_t product; /** * My transmit handle for the current message to a Alice/Bob */ struct GNUNET_CADET_TransmitHandle *service_transmit_handle; /** * My transmit handle for the current message to the client */ struct GNUNET_SERVER_TransmitHandle *client_transmit_handle; /** * channel-handle associated with our cadet handle */ struct GNUNET_CADET_Channel *channel; /** * Handle to a task that sends a msg to the our client */ GNUNET_SCHEDULER_TaskIdentifier client_notification_task; }; /** * Send a multi part chunk of a service request from alice to bob. * This element only contains a part of the elements-vector (session->a[]), * mask and public key set have to be contained within the first message * * This allows a ~32kbit key length while using 32000 elements or 62000 elements per request. * * @param cls the associated service session */ static void prepare_alices_cyrptodata_message_multipart (void *cls); /** * Send a multi part chunk of a service response from Bob to Alice. * This element only contains the two permutations of R, R'. * * @param cls the associated service session */ static void prepare_bobs_cryptodata_message_multipart (void *cls); /** * GNUnet configuration handle */ static const struct GNUNET_CONFIGURATION_Handle * cfg; /** * Handle to the core service (NULL until we've connected to it). */ static struct GNUNET_CADET_Handle *my_cadet; /** * The identity of this host. */ static struct GNUNET_PeerIdentity me; /** * Service's own public key */ static struct GNUNET_CRYPTO_PaillierPublicKey my_pubkey; /** * Service's own private key */ static struct GNUNET_CRYPTO_PaillierPrivateKey my_privkey; /** * Service's offset for values that could possibly be negative but are plaintext for encryption. */ static gcry_mpi_t my_offset; /** * Head of our double linked list for client-requests sent to us. * for all of these elements we calculate a scalar product with a remote peer * split between service->service and client->service for simplicity */ static struct ServiceSession *from_client_head; /** * Tail of our double linked list for client-requests sent to us. * for all of these elements we calculate a scalar product with a remote peer * split between service->service and client->service for simplicity */ static struct ServiceSession *from_client_tail; /** * Head of our double linked list for service-requests sent to us. * for all of these elements we help the requesting service in calculating a scalar product * split between service->service and client->service for simplicity */ static struct ServiceSession *from_service_head; /** * Tail of our double linked list for service-requests sent to us. * for all of these elements we help the requesting service in calculating a scalar product * split between service->service and client->service for simplicity */ static struct ServiceSession *from_service_tail; /** * Certain events (callbacks for server & cadet operations) must not be queued after shutdown. */ static int do_shutdown; /** * computes the square sum over a vector of a given length. * * @param vector the vector to encrypt * @param length the length of the vector * @return an MPI value containing the calculated sum, never NULL */ static gcry_mpi_t compute_square_sum (gcry_mpi_t *vector, uint32_t length) { gcry_mpi_t elem; gcry_mpi_t sum; int32_t i; GNUNET_assert (sum = gcry_mpi_new (0)); GNUNET_assert (elem = gcry_mpi_new (0)); // calculare E(sum (ai ^ 2), publickey) for (i = 0; i < length; i++) { gcry_mpi_mul (elem, vector[i], vector[i]); gcry_mpi_add (sum, sum, elem); } gcry_mpi_release (elem); return sum; } /** * Safely frees ALL memory areas referenced by a session. * * @param session - the session to free elements from */ static void free_session_variables (struct ServiceSession *s) { while (NULL != s->a_head) { struct SortedValue * e = s->a_head; GNUNET_free (e->elem); gcry_mpi_release (e->val); GNUNET_CONTAINER_DLL_remove (s->a_head, s->a_tail, e); GNUNET_free (e); } if (s->e_a) { GNUNET_free (s->e_a); s->e_a = NULL; } if (s->remote_pubkey) { GNUNET_free(s->remote_pubkey); s->remote_pubkey=NULL; } if (s->sorted_elements) { GNUNET_free (s->sorted_elements); s->sorted_elements = NULL; } if (s->intersected_elements) { GNUNET_CONTAINER_multihashmap_destroy (s->intersected_elements); //elements are freed independently in session->a_head/tail s->intersected_elements = NULL; } if (s->intersection_listen) { GNUNET_SET_listen_cancel (s->intersection_listen); s->intersection_listen = NULL; } if (s->intersection_op) { GNUNET_SET_operation_cancel (s->intersection_op); s->intersection_op = NULL; } if (s->intersection_set) { GNUNET_SET_destroy (s->intersection_set); s->intersection_set = NULL; } if (s->msg) { GNUNET_free (s->msg); s->msg = NULL; } if (s->r) { GNUNET_free (s->r); s->r = NULL; } if (s->r_prime) { GNUNET_free (s->r_prime); s->r_prime = NULL; } if (s->s) { GNUNET_free (s->s); s->s = NULL; } if (s->s_prime) { GNUNET_free (s->s_prime); s->s_prime = NULL; } if (s->product) { gcry_mpi_release (s->product); s->product = NULL; } } /** * Primitive callback for copying over a message, as they * usually are too complex to be handled in the callback itself. * clears a session-callback, if a session was handed over and the transmit handle was stored * * @param cls the session containing the message object * @param size the size of the buffer we got * @param buf the buffer to copy the message to * @return 0 if we couldn't copy, else the size copied over */ static size_t cb_transfer_message (void *cls, size_t size, void *buf) { struct ServiceSession * s = cls; uint16_t type; GNUNET_assert (buf); if (ntohs (s->msg->size) != size) { GNUNET_break (0); return 0; } type = ntohs (s->msg->type); memcpy (buf, s->msg, size); GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Sent a message of type %hu.\n", type); GNUNET_free (s->msg); s->msg = NULL; switch (type) { case GNUNET_MESSAGE_TYPE_SCALARPRODUCT_RESULT: s->client_transmit_handle = NULL; free_session_variables (s); break; case GNUNET_MESSAGE_TYPE_SCALARPRODUCT_SESSION_INITIALIZATION: s->service_transmit_handle = NULL; break; case GNUNET_MESSAGE_TYPE_SCALARPRODUCT_ALICE_CRYPTODATA: case GNUNET_MESSAGE_TYPE_SCALARPRODUCT_ALICE_CRYPTODATA_MULTIPART: s->service_transmit_handle = NULL; if (s->used_element_count != s->transferred_element_count) prepare_alices_cyrptodata_message_multipart (s); else s->channel = NULL; break; case GNUNET_MESSAGE_TYPE_SCALARPRODUCT_BOB_CRYPTODATA: case GNUNET_MESSAGE_TYPE_SCALARPRODUCT_BOB_CRYPTODATA_MULTIPART: s->service_transmit_handle = NULL; if (s->used_element_count != s->transferred_element_count) prepare_bobs_cryptodata_message_multipart (s); else s->channel = NULL; break; default: GNUNET_assert (0); } return size; } /** * Finds a not terminated client/service session in the * given DLL based on session key, element count and state. * * @param tail - the tail of the DLL * @param key - the key we want to search for * @param peerid - a pointer to the peer ID of the associated peer, NULL to ignore * @return a pointer to a matching session, or NULL */ static struct ServiceSession * find_matching_session (struct ServiceSession * tail, const struct GNUNET_HashCode * key, const struct GNUNET_PeerIdentity * peerid) { struct ServiceSession * s; for (s = tail; NULL != s; s = s->prev) { // if the key matches, and the element_count is same if (0 == memcmp (&s->session_id, key, sizeof (struct GNUNET_HashCode))) { // if peerid is NULL OR same as the peer Id in the queued request if ((NULL == peerid) || (0 == memcmp (&s->peer, peerid, sizeof (struct GNUNET_PeerIdentity)))) // matches and is not an already terminated session return s; } } return NULL; } /** * A client disconnected. * * Remove the associated session(s), release data structures * and cancel pending outgoing transmissions to the client. * if the session has not yet completed, we also cancel Alice's request to Bob. * * @param cls closure, NULL * @param client identification of the client */ static void cb_client_disconnect (void *cls, struct GNUNET_SERVER_Client *client) { struct ServiceSession *s; if (NULL == client) return; GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, _ ("Client %p disconnected from us.\n"), client); s = GNUNET_SERVER_client_get_user_context (client, struct ServiceSession); if (NULL == s) return; GNUNET_CONTAINER_DLL_remove (from_client_head, from_client_tail, s); if (NULL != s->service_transmit_handle) { GNUNET_CADET_notify_transmit_ready_cancel (s->service_transmit_handle); s->service_transmit_handle = NULL; } if (NULL != s->channel) { GNUNET_CADET_channel_destroy (s->channel); s->channel = NULL; } if (GNUNET_SCHEDULER_NO_TASK != s->client_notification_task) { GNUNET_SCHEDULER_cancel (s->client_notification_task); s->client_notification_task = GNUNET_SCHEDULER_NO_TASK; } if (NULL != s->client_transmit_handle) { GNUNET_SERVER_notify_transmit_ready_cancel (s->client_transmit_handle); s->client_transmit_handle = NULL; } free_session_variables (s); GNUNET_free (s); } /** * Notify the client that the session has succeeded or failed completely. * This message gets sent to * * alice's client if bob disconnected or to * * bob's client if the operation completed or alice disconnected * * @param cls the associated client session * @param tc the task context handed to us by the scheduler, unused */ static void prepare_client_end_notification (void * cls, const struct GNUNET_SCHEDULER_TaskContext * tc) { struct ServiceSession * s = cls; struct ClientResponseMessage *msg; s->client_notification_task = GNUNET_SCHEDULER_NO_TASK; msg = GNUNET_new (struct ClientResponseMessage); msg->header.size = htons (sizeof (struct ClientResponseMessage)); msg->header.type = htons (GNUNET_MESSAGE_TYPE_SCALARPRODUCT_RESULT); // signal error if not signalized, positive result-range field but zero length. msg->product_length = htonl (0); msg->status = htonl(s->active); s->msg = &msg->header; //transmit this message to our client s->client_transmit_handle = GNUNET_SERVER_notify_transmit_ready (s->client, sizeof (struct ClientResponseMessage), GNUNET_TIME_UNIT_FOREVER_REL, &cb_transfer_message, s); // if we could not even queue our request, something is wrong if (NULL == s->client_transmit_handle) { GNUNET_log (GNUNET_ERROR_TYPE_WARNING, _("Could not send message to client (%p)!\n"), s->client); GNUNET_SERVER_client_disconnect (s->client); free_session_variables(s); GNUNET_CONTAINER_DLL_remove (from_client_head, from_client_tail, s); GNUNET_free(s); return; } GNUNET_log (GNUNET_ERROR_TYPE_INFO, _("Sending session-end notification to client (%p) for session %s\n"), s->client, GNUNET_h2s (&s->session_id)); } /** * Executed by Alice, fills in a service-request message and sends it to the given peer * * @param cls the session associated with this request */ static void prepare_alices_cyrptodata_message (void *cls) { struct ServiceSession * s = cls; struct AliceCryptodataMessage * msg; struct GNUNET_CRYPTO_PaillierCiphertext * payload; unsigned int i; uint32_t msg_length; gcry_mpi_t a; GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, _ ("Successfully created new channel to peer (%s)!\n"), GNUNET_i2s (&s->peer)); msg_length = sizeof (struct AliceCryptodataMessage) +s->used_element_count * sizeof (struct GNUNET_CRYPTO_PaillierCiphertext); if (GNUNET_SERVER_MAX_MESSAGE_SIZE > msg_length) { s->transferred_element_count = s->used_element_count; } else { //create a multipart msg, first we calculate a new msg size for the head msg s->transferred_element_count = (GNUNET_SERVER_MAX_MESSAGE_SIZE - 1 - sizeof (struct AliceCryptodataMessage)) / sizeof (struct GNUNET_CRYPTO_PaillierCiphertext); msg_length = sizeof (struct AliceCryptodataMessage) +s->transferred_element_count * sizeof (struct GNUNET_CRYPTO_PaillierCiphertext); } msg = GNUNET_malloc (msg_length); msg->header.size = htons (msg_length); msg->header.type = htons (GNUNET_MESSAGE_TYPE_SCALARPRODUCT_ALICE_CRYPTODATA); msg->contained_element_count = htonl (s->transferred_element_count); // fill in the payload payload = (struct GNUNET_CRYPTO_PaillierCiphertext *) &msg[1]; // now copy over the sorted element vector a = gcry_mpi_new (0); for (i = 0; i < s->transferred_element_count; i++) { gcry_mpi_add (a, s->sorted_elements[i], my_offset); GNUNET_CRYPTO_paillier_encrypt (&my_pubkey, a, 3, &payload[i]); } gcry_mpi_release (a); s->msg = (struct GNUNET_MessageHeader *) msg; GNUNET_log (GNUNET_ERROR_TYPE_INFO, _("Transmitting service request.\n")); //transmit via cadet messaging s->service_transmit_handle = GNUNET_CADET_notify_transmit_ready (s->channel, GNUNET_YES, GNUNET_TIME_UNIT_FOREVER_REL, msg_length, &cb_transfer_message, s); if (NULL == s->service_transmit_handle) { GNUNET_log (GNUNET_ERROR_TYPE_ERROR, _("Could not send message to channel!\n")); GNUNET_free (msg); s->msg = NULL; s->active = GNUNET_SYSERR; s->client_notification_task = GNUNET_SCHEDULER_add_now (&prepare_client_end_notification, s); return; } } /** * Send a multipart chunk of a service response from bob to alice. * This element only contains the two permutations of R, R'. * * @param cls the associated service session */ static void prepare_bobs_cryptodata_message_multipart (void *cls) { struct ServiceSession * s = cls; struct GNUNET_CRYPTO_PaillierCiphertext * payload; struct MultipartMessage * msg; unsigned int i; unsigned int j; uint32_t msg_length; uint32_t todo_count; msg_length = sizeof (struct MultipartMessage); todo_count = s->used_element_count - s->transferred_element_count; if (todo_count > MULTIPART_ELEMENT_CAPACITY / 2) // send the currently possible maximum chunk, we always transfer both permutations todo_count = MULTIPART_ELEMENT_CAPACITY / 2; msg_length += todo_count * sizeof (struct GNUNET_CRYPTO_PaillierCiphertext) * 2; msg = GNUNET_malloc (msg_length); msg->header.type = htons (GNUNET_MESSAGE_TYPE_SCALARPRODUCT_ALICE_CRYPTODATA_MULTIPART); msg->header.size = htons (msg_length); msg->contained_element_count = htonl (todo_count); payload = (struct GNUNET_CRYPTO_PaillierCiphertext *) &msg[1]; for (i = s->transferred_element_count, j = 0; i < s->transferred_element_count + todo_count; i++) { //r[i][p] and r[i][q] memcpy (&payload[j++], &s->r[i], sizeof (struct GNUNET_CRYPTO_PaillierCiphertext)); memcpy (&payload[j++], &s->r_prime[i], sizeof (struct GNUNET_CRYPTO_PaillierCiphertext)); } s->transferred_element_count += todo_count; s->msg = (struct GNUNET_MessageHeader *) msg; s->service_transmit_handle = GNUNET_CADET_notify_transmit_ready (s->channel, GNUNET_YES, GNUNET_TIME_UNIT_FOREVER_REL, msg_length, &cb_transfer_message, s); if (NULL == s->service_transmit_handle) { GNUNET_log (GNUNET_ERROR_TYPE_ERROR, _("Could not send service-response message via cadet!)\n")); GNUNET_free (msg); s->msg = NULL; GNUNET_CADET_channel_destroy(s->channel); s->response->active = GNUNET_SYSERR; GNUNET_CONTAINER_DLL_remove (from_service_head, from_service_tail, s); s->response->client_notification_task = GNUNET_SCHEDULER_add_now (&prepare_client_end_notification, s->response); free_session_variables(s); GNUNET_free(s); return; } if (s->transferred_element_count == s->used_element_count) { // final part s->active = GNUNET_NO; GNUNET_free (s->r_prime); GNUNET_free (s->r); s->r_prime = NULL; s->r = NULL; } } /** * Bob executes: * generates the response message to be sent to alice after computing * the values (1), (2), S and S' * (1)[]: $E_A(a_{pi(i)}) times E_A(- r_{pi(i)} - b_{pi(i)}) &= E_A(a_{pi(i)} - r_{pi(i)} - b_{pi(i)})$ * (2)[]: $E_A(a_{pi'(i)}) times E_A(- r_{pi'(i)}) &= E_A(a_{pi'(i)} - r_{pi'(i)})$ * S: $S := E_A(sum (r_i + b_i)^2)$ * S': $S' := E_A(sum r_i^2)$ * * @param session the associated requesting session with alice */ static void prepare_bobs_cryptodata_message (void *cls, const struct GNUNET_SCHEDULER_TaskContext * tc) { struct ServiceSession * s = cls; struct ServiceResponseMessage * msg; uint32_t msg_length = 0; struct GNUNET_CRYPTO_PaillierCiphertext * payload; int i; msg_length = sizeof (struct ServiceResponseMessage) + 2 * sizeof (struct GNUNET_CRYPTO_PaillierCiphertext); // s, stick if (GNUNET_SERVER_MAX_MESSAGE_SIZE > msg_length + 2 * s->used_element_count * sizeof (struct GNUNET_CRYPTO_PaillierCiphertext)) { //r, r' msg_length += 2 * s->used_element_count * sizeof (struct GNUNET_CRYPTO_PaillierCiphertext); s->transferred_element_count = s->used_element_count; } else s->transferred_element_count = (GNUNET_SERVER_MAX_MESSAGE_SIZE - 1 - msg_length) / (sizeof (struct GNUNET_CRYPTO_PaillierCiphertext) * 2); msg = GNUNET_malloc (msg_length); msg->header.type = htons (GNUNET_MESSAGE_TYPE_SCALARPRODUCT_BOB_CRYPTODATA); msg->header.size = htons (msg_length); msg->total_element_count = htonl (s->total); msg->used_element_count = htonl (s->used_element_count); msg->contained_element_count = htonl (s->transferred_element_count); memcpy (&msg->key, &s->session_id, sizeof (struct GNUNET_HashCode)); payload = (struct GNUNET_CRYPTO_PaillierCiphertext *) &msg[1]; memcpy (&payload[0], s->s, sizeof (struct GNUNET_CRYPTO_PaillierCiphertext)); memcpy (&payload[1], s->s_prime, sizeof (struct GNUNET_CRYPTO_PaillierCiphertext)); GNUNET_free (s->s_prime); s->s_prime = NULL; GNUNET_free (s->s); s->s = NULL; payload = &payload[2]; // convert k[][] for (i = 0; i < s->transferred_element_count; i++) { //k[i][p] and k[i][q] memcpy (&payload[i * 2], &s->r[i], sizeof (struct GNUNET_CRYPTO_PaillierCiphertext)); memcpy (&payload[i * 2 + 1], &s->r_prime[i], sizeof (struct GNUNET_CRYPTO_PaillierCiphertext)); } s->msg = (struct GNUNET_MessageHeader *) msg; s->service_transmit_handle = GNUNET_CADET_notify_transmit_ready (s->channel, GNUNET_YES, GNUNET_TIME_UNIT_FOREVER_REL, msg_length, &cb_transfer_message, s); if (NULL == s->service_transmit_handle) { //disconnect our client GNUNET_log (GNUNET_ERROR_TYPE_ERROR, _("Could not send service-response message via cadet!)\n")); GNUNET_free (msg); s->msg = NULL; GNUNET_CONTAINER_DLL_remove (from_service_head, from_service_tail, s); GNUNET_CADET_channel_destroy(s->channel); s->response->active = GNUNET_SYSERR; s->response->client_notification_task = GNUNET_SCHEDULER_add_now (&prepare_client_end_notification, s->response); free_session_variables(s); GNUNET_free(s); return; } if (s->transferred_element_count != s->used_element_count) { // multipart } else { //singlepart s->active = GNUNET_NO; GNUNET_free (s->r); s->r = NULL; GNUNET_free (s->r_prime); s->r_prime = NULL; } } /** * executed by bob: * compute the values * (1)[]: $E_A(a_{pi(i)}) otimes E_A(- r_{pi(i)} - b_{pi(i)}) &= E_A(a_{pi(i)} - r_{pi(i)} - b_{pi(i)})$ * (2)[]: $E_A(a_{pi'(i)}) otimes E_A(- r_{pi'(i)}) &= E_A(a_{pi'(i)} - r_{pi'(i)})$ * S: $S := E_A(sum (r_i + b_i)^2)$ * S': $S' := E_A(sum r_i^2)$ * * @param request the requesting session + bob's requesting peer */ static void compute_service_response (struct ServiceSession *session) { int i; unsigned int * p; unsigned int * q; uint32_t count; gcry_mpi_t * rand = NULL; gcry_mpi_t tmp; gcry_mpi_t * b; struct GNUNET_CRYPTO_PaillierCiphertext * a; struct GNUNET_CRYPTO_PaillierCiphertext * r; struct GNUNET_CRYPTO_PaillierCiphertext * r_prime; struct GNUNET_CRYPTO_PaillierCiphertext * s; struct GNUNET_CRYPTO_PaillierCiphertext * s_prime; count = session->used_element_count; a = session->e_a; b = session->sorted_elements; q = GNUNET_CRYPTO_random_permute (GNUNET_CRYPTO_QUALITY_WEAK, count); p = GNUNET_CRYPTO_random_permute (GNUNET_CRYPTO_QUALITY_WEAK, count); for (i = 0; i < count; i++) GNUNET_assert (NULL != (rand[i] = gcry_mpi_new (0))); r = GNUNET_malloc (sizeof (struct GNUNET_CRYPTO_PaillierCiphertext) * count); r_prime = GNUNET_malloc (sizeof (struct GNUNET_CRYPTO_PaillierCiphertext) * count); s = GNUNET_malloc (sizeof (struct GNUNET_CRYPTO_PaillierCiphertext)); s_prime = GNUNET_malloc (sizeof (struct GNUNET_CRYPTO_PaillierCiphertext)); for (i = 0; i < count; i++) { int32_t svalue; svalue = (int32_t) GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK, UINT32_MAX); // long to gcry_mpi_t if (svalue < 0) gcry_mpi_sub_ui (rand[i], rand[i], -svalue); else rand[i] = gcry_mpi_set_ui (rand[i], svalue); } tmp = gcry_mpi_new (0); // encrypt the element // for the sake of readability I decided to have dedicated permutation // vectors, which get rid of all the lookups in p/q. // however, ap/aq are not absolutely necessary but are just abstraction // Calculate Kp = E(S + a_pi) (+) E(S - r_pi - b_pi) for (i = 0; i < count; i++) { // E(S - r_pi - b_pi) gcry_mpi_sub (tmp, my_offset, rand[p[i]]); gcry_mpi_sub (tmp, tmp, b[p[i]]); GNUNET_CRYPTO_paillier_encrypt (session->remote_pubkey, tmp, 2, &r[i]); // E(S - r_pi - b_pi) * E(S + a_pi) == E(2*S + a - r - b) GNUNET_CRYPTO_paillier_hom_add (session->remote_pubkey, &r[i], &a[p[i]], &r[i]); } // Calculate Kq = E(S + a_qi) (+) E(S - r_qi) for (i = 0; i < count; i++) { // E(S - r_qi) gcry_mpi_sub (tmp, my_offset, rand[q[i]]); GNUNET_assert (2 == GNUNET_CRYPTO_paillier_encrypt (session->remote_pubkey, tmp, 2, &r_prime[i])); // E(S - r_qi) * E(S + a_qi) == E(2*S + a_qi - r_qi) GNUNET_assert (1 == GNUNET_CRYPTO_paillier_hom_add (session->remote_pubkey, &r_prime[i], &a[q[i]], &r_prime[i])); } // Calculate S' = E(SUM( r_i^2 )) tmp = compute_square_sum (rand, count); GNUNET_CRYPTO_paillier_encrypt (session->remote_pubkey, tmp, 1, s_prime); // Calculate S = E(SUM( (r_i + b_i)^2 )) for (i = 0; i < count; i++) gcry_mpi_add (rand[i], rand[i], b[i]); tmp = compute_square_sum (rand, count); GNUNET_CRYPTO_paillier_encrypt (session->remote_pubkey, tmp, 1, s); session->r = r; session->r_prime = r_prime; session->s = s; session->s_prime = s_prime; // release rand, b and a for (i = 0; i < count; i++) { gcry_mpi_release (rand[i]); gcry_mpi_release (b[i]); } gcry_mpi_release (tmp); GNUNET_free (session->e_a); session->e_a = NULL; GNUNET_free (p); GNUNET_free (q); GNUNET_free (b); GNUNET_free (rand); // copy the r[], r_prime[], S and Stick into a new message, prepare_service_response frees these GNUNET_SCHEDULER_add_now (&prepare_bobs_cryptodata_message, s); } /** * Iterator over all hash map entries in session->intersected_elements. * * @param cls closure * @param key current key code * @param value value in the hash map * @return #GNUNET_YES if we should continue to * iterate, * #GNUNET_NO if not. */ int cb_insert_element_sorted (void *cls, const struct GNUNET_HashCode *key, void *value) { struct ServiceSession * s = (struct ServiceSession*) cls; struct SortedValue * e = GNUNET_new (struct SortedValue); struct SortedValue * o = s->a_head; int64_t val; e->elem = value; e->val = gcry_mpi_new (0); val = (int64_t) GNUNET_ntohll (e->elem->value); if (0 > val) gcry_mpi_sub_ui (e->val, e->val, -val); else gcry_mpi_add_ui (e->val, e->val, val); // insert as first element with the lowest key if (NULL == s->a_head || (0 <= GNUNET_CRYPTO_hash_cmp (&s->a_head->elem->key, &e->elem->key))) { GNUNET_CONTAINER_DLL_insert (s->a_head, s->a_tail, e); return GNUNET_YES; } else if (0 > GNUNET_CRYPTO_hash_cmp (&s->a_tail->elem->key, &e->elem->key)) { // insert as last element with the highest key GNUNET_CONTAINER_DLL_insert_tail (s->a_head, s->a_tail, e); return GNUNET_YES; } // insert before the first higher/equal element do { if (0 <= GNUNET_CRYPTO_hash_cmp (&o->elem->key, &e->elem->key)) { GNUNET_CONTAINER_DLL_insert_before (s->a_head, s->a_tail, o, e); return GNUNET_YES; } o = o->next; } while (NULL != o); // broken DLL GNUNET_assert (0); } /** * Callback for set operation results. Called for each element * in the result set. * * @param cls closure * @param element a result element, only valid if status is #GNUNET_SET_STATUS_OK * @param status see `enum GNUNET_SET_Status` */ static void cb_intersection_element_removed (void *cls, const struct GNUNET_SET_Element *element, enum GNUNET_SET_Status status) { struct ServiceSession * s = cls; struct GNUNET_SCALARPRODUCT_Element * se; int i; switch (status) { case GNUNET_SET_STATUS_OK: //this element has been removed from the set se = GNUNET_CONTAINER_multihashmap_get (s->intersected_elements, element->data); GNUNET_CONTAINER_multihashmap_remove (s->intersected_elements, element->data, se); LOG (GNUNET_ERROR_TYPE_DEBUG, "%s: removed element with key %s value %d\n", s->role == ALICE ? "ALICE" : "BOB", GNUNET_h2s(&se->key), se->value); return; case GNUNET_SET_STATUS_DONE: s->intersection_op = NULL; s->intersection_set = NULL; s->used_element_count = GNUNET_CONTAINER_multihashmap_iterate (s->intersected_elements, &cb_insert_element_sorted, s); LOG (GNUNET_ERROR_TYPE_DEBUG, "%s: Finished intersection, %d items remain\n", s->role == ALICE ? "ALICE" : "BOB", s->used_element_count); if (2 > s->used_element_count) { // failed! do not leak information about our single remaining element! // continue after the loop break; } s->sorted_elements = GNUNET_malloc (s->used_element_count * sizeof (gcry_mpi_t)); for (i = 0; NULL != s->a_head; i++) { struct SortedValue* a = s->a_head; GNUNET_assert (i < s->used_element_count); s->sorted_elements[i] = a->val; GNUNET_CONTAINER_DLL_remove (s->a_head, s->a_tail, a); GNUNET_free (a->elem); } GNUNET_assert (i == s->used_element_count); if (ALICE == s->role) { prepare_alices_cyrptodata_message (s); return; } else if (s->used_element_count == s->transferred_element_count) { compute_service_response (s); return; } break; default: LOG (GNUNET_ERROR_TYPE_DEBUG, "%s: OOOPS %d", s->role == ALICE ? "ALICE" : "BOB", status); if (NULL != s->intersection_listen) { GNUNET_SET_listen_cancel (s->intersection_listen); s->intersection_listen = NULL; } // the op failed and has already been invalidated by the set service break; } s->intersection_op = NULL; s->intersection_set = NULL; //failed if we go here GNUNET_break_op (0); // and notify our client-session that we could not complete the session if (ALICE == s->role) { s->active = GNUNET_SYSERR; s->client_notification_task = GNUNET_SCHEDULER_add_now (&prepare_client_end_notification, s); } else { GNUNET_CONTAINER_DLL_remove (from_service_head, from_service_tail, s); free_session_variables (s); s->response->active = GNUNET_SYSERR; s->response->client_notification_task = GNUNET_SCHEDULER_add_now (&prepare_client_end_notification, s->response); GNUNET_free(s); } } /** * Called when another peer wants to do a set operation with the * local peer. If a listen error occurs, the @a request is NULL. * * @param cls closure * @param other_peer the other peer * @param context_msg message with application specific information from * the other peer * @param request request from the other peer (never NULL), use GNUNET_SET_accept() * to accept it, otherwise the request will be refused * Note that we can't just return value from the listen callback, * as it is also necessary to specify the set we want to do the * operation with, whith sometimes can be derived from the context * message. It's necessary to specify the timeout. */ static void cb_intersection_request_alice (void *cls, const struct GNUNET_PeerIdentity *other_peer, const struct GNUNET_MessageHeader *context_msg, struct GNUNET_SET_Request *request) { struct ServiceSession * s = cls; s->intersection_op = GNUNET_SET_accept (request, GNUNET_SET_RESULT_REMOVED, cb_intersection_element_removed, s); if (NULL == s->intersection_op) { s->active = GNUNET_SYSERR; s->client_notification_task = GNUNET_SCHEDULER_add_now (&prepare_client_end_notification, s); return; } if (GNUNET_OK != GNUNET_SET_commit (s->intersection_op, s->intersection_set)) { s->active = GNUNET_SYSERR; s->client_notification_task = GNUNET_SCHEDULER_add_now (&prepare_client_end_notification, s); return; } s->intersection_set = NULL; s->intersection_listen = NULL; } /** * prepare the response we will send to alice or bobs' clients. * in Bobs case the product will be NULL. * * @param cls the session associated with our client. * @param tc the task context handed to us by the scheduler, unused */ static void prepare_client_response (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc) { struct ServiceSession * s = cls; struct ClientResponseMessage *msg; unsigned char * product_exported = NULL; size_t product_length = 0; uint32_t msg_length = 0; int8_t range = -1; gcry_error_t rc; int sign; s->client_notification_task = GNUNET_SCHEDULER_NO_TASK; if (s->product) { gcry_mpi_t value = gcry_mpi_new (0); sign = gcry_mpi_cmp_ui (s->product, 0); // libgcrypt can not handle a print of a negative number // if (a->sign) return gcry_error (GPG_ERR_INTERNAL); /* Can't handle it yet. */ if (0 > sign) { gcry_mpi_sub (value, value, s->product); } else if (0 < sign) { range = 1; gcry_mpi_add (value, value, s->product); } else range = 0; gcry_mpi_release (s->product); s->product = NULL; // get representation as string if (range && (0 != (rc = gcry_mpi_aprint (GCRYMPI_FMT_STD, &product_exported, &product_length, value)))) { LOG_GCRY (GNUNET_ERROR_TYPE_ERROR, "gcry_mpi_scan", rc); product_length = 0; range = -1; // signal error with product-length = 0 and range = -1 } gcry_mpi_release (value); } msg_length = sizeof (struct ClientResponseMessage) + product_length; msg = GNUNET_malloc (msg_length); if (product_exported != NULL) { memcpy (&msg[1], product_exported, product_length); GNUNET_free (product_exported); } msg->header.type = htons (GNUNET_MESSAGE_TYPE_SCALARPRODUCT_RESULT); msg->header.size = htons (msg_length); msg->range = range; msg->product_length = htonl (product_length); s->msg = (struct GNUNET_MessageHeader *) msg; s->client_transmit_handle = GNUNET_SERVER_notify_transmit_ready (s->client, msg_length, GNUNET_TIME_UNIT_FOREVER_REL, &cb_transfer_message, s); GNUNET_break (NULL != s->client_transmit_handle); GNUNET_log (GNUNET_ERROR_TYPE_INFO, _ ("Sent result to client (%p), this session (%s) has ended!\n"), s->client, GNUNET_h2s (&s->session_id)); } /** * Executed by Alice, fills in a service-request message and sends it to the given peer * * @param session the session associated with this request */ static void prepare_alices_computation_request (struct ServiceSession * s) { struct ServiceRequestMessage * msg; GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, _("Successfully created new channel to peer (%s)!\n"), GNUNET_i2s (&s->peer)); msg = GNUNET_new (struct ServiceRequestMessage); msg->header.type = htons (GNUNET_MESSAGE_TYPE_SCALARPRODUCT_SESSION_INITIALIZATION); memcpy (&msg->session_id, &s->session_id, sizeof (struct GNUNET_HashCode)); msg->header.size = htons (sizeof (struct ServiceRequestMessage)); s->msg = (struct GNUNET_MessageHeader *) msg; GNUNET_log (GNUNET_ERROR_TYPE_INFO, _("Transmitting service request.\n")); //transmit via cadet messaging s->service_transmit_handle = GNUNET_CADET_notify_transmit_ready (s->channel, GNUNET_YES, GNUNET_TIME_UNIT_FOREVER_REL, sizeof (struct ServiceRequestMessage), &cb_transfer_message, s); if (!s->service_transmit_handle) { GNUNET_log (GNUNET_ERROR_TYPE_ERROR, _("Could not send message to channel!\n")); GNUNET_free (msg); s->msg = NULL; s->active = GNUNET_SYSERR; s->client_notification_task = GNUNET_SCHEDULER_add_now (&prepare_client_end_notification, s); return; } } /** * Send a multi part chunk of a service request from alice to bob. * This element only contains a part of the elements-vector (session->a[]), * mask and public key set have to be contained within the first message * * This allows a ~32kbit key length while using 32000 elements or 62000 elements per request. * * @param cls the associated service session */ static void prepare_alices_cyrptodata_message_multipart (void *cls) { struct ServiceSession * s = cls; struct MultipartMessage * msg; struct GNUNET_CRYPTO_PaillierCiphertext * payload; unsigned int i; uint32_t msg_length; uint32_t todo_count; gcry_mpi_t a; msg_length = sizeof (struct MultipartMessage); todo_count = s->used_element_count - s->transferred_element_count; if (todo_count > MULTIPART_ELEMENT_CAPACITY) // send the currently possible maximum chunk todo_count = MULTIPART_ELEMENT_CAPACITY; msg_length += todo_count * sizeof (struct GNUNET_CRYPTO_PaillierCiphertext); msg = GNUNET_malloc (msg_length); msg->header.type = htons (GNUNET_MESSAGE_TYPE_SCALARPRODUCT_ALICE_CRYPTODATA_MULTIPART); msg->header.size = htons (msg_length); msg->contained_element_count = htonl (todo_count); payload = (struct GNUNET_CRYPTO_PaillierCiphertext *) &msg[1]; // now copy over the sorted element vector a = gcry_mpi_new (0); for (i = s->transferred_element_count; i < todo_count; i++) { gcry_mpi_add (a, s->sorted_elements[i], my_offset); GNUNET_CRYPTO_paillier_encrypt (&my_pubkey, a, 3, &payload[i - s->transferred_element_count]); } gcry_mpi_release (a); s->transferred_element_count += todo_count; s->msg = (struct GNUNET_MessageHeader *) msg; GNUNET_log (GNUNET_ERROR_TYPE_INFO, _ ("Transmitting service request.\n")); //transmit via cadet messaging s->service_transmit_handle = GNUNET_CADET_notify_transmit_ready (s->channel, GNUNET_YES, GNUNET_TIME_UNIT_FOREVER_REL, msg_length, &cb_transfer_message, s); if (!s->service_transmit_handle) { GNUNET_log (GNUNET_ERROR_TYPE_ERROR, _("Could not send service-request multipart message to channel!\n")); GNUNET_free (msg); s->msg = NULL; s->active = GNUNET_SYSERR; s->client_notification_task = GNUNET_SCHEDULER_add_now (&prepare_client_end_notification, s); return; } } /** * Our client has finished sending us its multipart message. * * @param session the service session context */ static void client_request_complete_bob (struct ServiceSession * client_session) { struct ServiceSession * s; //check if service queue contains a matching request s = find_matching_session (from_service_tail, &client_session->session_id, NULL); if (NULL != s) { GNUNET_log (GNUNET_ERROR_TYPE_INFO, _ ("Got client-responder-session with key %s and a matching service-request-session set, processing.\n"), GNUNET_h2s (&client_session->session_id)); s->response = client_session; s->intersected_elements = client_session->intersected_elements; client_session->intersected_elements = NULL; s->intersection_set = client_session->intersection_set; client_session->intersection_set = NULL; s->intersection_op = GNUNET_SET_prepare (&s->peer, &s->session_id, NULL, GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK, UINT16_MAX), GNUNET_SET_RESULT_REMOVED, cb_intersection_element_removed, s); GNUNET_SET_commit (s->intersection_op, s->intersection_set); } else { 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 (&client_session->session_id)); // no matching session exists yet, store the response // for later processing by handle_service_request() } } /** * Our client has finished sending us its multipart message. * * @param session the service session context */ static void client_request_complete_alice (struct ServiceSession * s) { GNUNET_log (GNUNET_ERROR_TYPE_INFO, _ ("Creating new channel for session with key %s.\n"), GNUNET_h2s (&s->session_id)); s->channel = GNUNET_CADET_channel_create (my_cadet, s, &s->peer, GNUNET_APPLICATION_TYPE_SCALARPRODUCT, GNUNET_CADET_OPTION_RELIABLE); if (NULL == s->channel) { s->active = GNUNET_SYSERR; s->client_notification_task = GNUNET_SCHEDULER_add_now (&prepare_client_end_notification, s); return; } s->intersection_listen = GNUNET_SET_listen (cfg, GNUNET_SET_OPERATION_INTERSECTION, &s->session_id, cb_intersection_request_alice, s); if (NULL == s->intersection_listen) { s->active = GNUNET_SYSERR; s->client_notification_task = GNUNET_SCHEDULER_add_now (&prepare_client_end_notification, s); return; } prepare_alices_computation_request (s); } static void handle_client_message_multipart (void *cls, struct GNUNET_SERVER_Client *client, const struct GNUNET_MessageHeader *message) { const struct ComputationMultipartMessage * msg = (const struct ComputationMultipartMessage *) message; struct ServiceSession *s; uint32_t contained_count; struct GNUNET_SCALARPRODUCT_Element *elements; uint32_t i; // only one concurrent session per client connection allowed, simplifies logics a lot... s = GNUNET_SERVER_client_get_user_context (client, struct ServiceSession); if (NULL == s) { GNUNET_SERVER_receive_done (client, GNUNET_OK); return; } contained_count = ntohl (msg->element_count_contained); //sanity check: is the message as long as the message_count fields suggests? if ((ntohs (msg->header.size) != (sizeof (struct ComputationMultipartMessage) +contained_count * sizeof (struct GNUNET_SCALARPRODUCT_Element))) || (0 == contained_count) || (s->total < s->transferred_element_count + contained_count)) { GNUNET_break_op (0); GNUNET_SERVER_receive_done (client, GNUNET_OK); return; } s->transferred_element_count += contained_count; elements = (struct GNUNET_SCALARPRODUCT_Element *) & msg[1]; for (i = 0; i < contained_count; i++) { struct GNUNET_SET_Element set_elem; struct GNUNET_SCALARPRODUCT_Element * elem; if (0 == GNUNET_ntohll (elements[i].value)) continue; elem = GNUNET_new (struct GNUNET_SCALARPRODUCT_Element); memcpy (elem, &elements[i], sizeof (struct GNUNET_SCALARPRODUCT_Element)); if (GNUNET_SYSERR == GNUNET_CONTAINER_multihashmap_put (s->intersected_elements, &elem->key, elem, GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY)) { GNUNET_free (elem); continue; } set_elem.data = &elem->key; set_elem.size = sizeof (elem->key); set_elem.type = 0; /* do we REALLY need this? */ GNUNET_SET_add_element (s->intersection_set, &set_elem, NULL, NULL); s->used_element_count++; } GNUNET_SERVER_receive_done (client, GNUNET_OK); if (s->total != s->transferred_element_count) // multipart msg return; if (ALICE == s->role) client_request_complete_alice (s); else client_request_complete_bob (s); } /** * Handler for a client request message. * Can either be type A or B * A: request-initiation to compute a scalar product with a peer * B: response role, keep the values + session and wait for a matching session or process a waiting request * * @param cls closure * @param client identification of the client * @param message the actual message */ static void handle_client_message (void *cls, struct GNUNET_SERVER_Client *client, const struct GNUNET_MessageHeader *message) { const struct ComputationMessage * msg = (const struct ComputationMessage *) message; struct ServiceSession * s; uint32_t contained_count; uint32_t total_count; uint32_t msg_type; struct GNUNET_SCALARPRODUCT_Element * elements; uint32_t i; // only one concurrent session per client connection allowed, simplifies logics a lot... s = GNUNET_SERVER_client_get_user_context (client, struct ServiceSession); if (NULL != s) { GNUNET_SERVER_receive_done (client, GNUNET_OK); return; } msg_type = ntohs (msg->header.type); total_count = ntohl (msg->element_count_total); contained_count = ntohl (msg->element_count_contained); if ((GNUNET_MESSAGE_TYPE_SCALARPRODUCT_CLIENT_TO_ALICE == msg_type) && (!memcmp (&msg->peer, &me, sizeof (struct GNUNET_PeerIdentity)))) { //session with ourself makes no sense! GNUNET_break_op (0); GNUNET_SERVER_receive_done (client, GNUNET_SYSERR); return; } //sanity check: is the message as long as the message_count fields suggests? if ((ntohs (msg->header.size) != (sizeof (struct ComputationMessage) + contained_count * sizeof (struct GNUNET_SCALARPRODUCT_Element))) || (0 == total_count)) { GNUNET_break_op (0); GNUNET_SERVER_receive_done (client, GNUNET_SYSERR); return; } // do we have a duplicate session here already? if (NULL != find_matching_session (from_client_tail, &msg->session_key, NULL)) { GNUNET_log (GNUNET_ERROR_TYPE_WARNING, _ ("Duplicate session information received, can not create new session with key `%s'\n"), GNUNET_h2s (&msg->session_key)); GNUNET_SERVER_receive_done (client, GNUNET_SYSERR); return; } s = GNUNET_new (struct ServiceSession); s->active = GNUNET_YES; s->client_notification_task = GNUNET_SCHEDULER_NO_TASK; s->client = client; s->total = total_count; s->transferred_element_count = contained_count; // get our transaction key memcpy (&s->session_id, &msg->session_key, sizeof (struct GNUNET_HashCode)); elements = (struct GNUNET_SCALARPRODUCT_Element *) & msg[1]; s->intersected_elements = GNUNET_CONTAINER_multihashmap_create (s->total, GNUNET_NO); s->intersection_set = GNUNET_SET_create (cfg, GNUNET_SET_OPERATION_INTERSECTION); for (i = 0; i < contained_count; i++) { struct GNUNET_SET_Element set_elem; struct GNUNET_SCALARPRODUCT_Element * elem; if (0 == GNUNET_ntohll (elements[i].value)) continue; elem = GNUNET_new (struct GNUNET_SCALARPRODUCT_Element); memcpy (elem, &elements[i], sizeof (struct GNUNET_SCALARPRODUCT_Element)); if (GNUNET_SYSERR == GNUNET_CONTAINER_multihashmap_put (s->intersected_elements, &elem->key, elem, GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY)) { GNUNET_free (elem); continue; } set_elem.data = &elem->key; set_elem.size = sizeof (elem->key); set_elem.type = 0; /* do we REALLY need this? */ GNUNET_SET_add_element (s->intersection_set, &set_elem, NULL, NULL); s->used_element_count++; } if (GNUNET_MESSAGE_TYPE_SCALARPRODUCT_CLIENT_TO_ALICE == msg_type) { s->role = ALICE; memcpy (&s->peer, &msg->peer, sizeof (struct GNUNET_PeerIdentity)); } else { s->role = BOB; } GNUNET_CONTAINER_DLL_insert (from_client_head, from_client_tail, s); GNUNET_SERVER_client_set_user_context (client, s); GNUNET_SERVER_receive_done (client, GNUNET_YES); if (s->total != s->transferred_element_count) // multipart msg return; if (ALICE == s->role) client_request_complete_alice (s); else client_request_complete_bob (s); } /** * Function called for inbound channels. * * @param cls closure * @param channel new handle to the channel * @param initiator peer that started the channel * @param port unused * @param options unused * @return session associated with the channel */ static void * cb_channel_incoming (void *cls, struct GNUNET_CADET_Channel *channel, const struct GNUNET_PeerIdentity *initiator, uint32_t port, enum GNUNET_CADET_ChannelOption options) { struct ServiceSession *s = GNUNET_new (struct ServiceSession); GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, _ ("New incoming channel from peer %s.\n"), GNUNET_i2s (initiator)); s->peer = *initiator; s->channel = channel; s->role = BOB; s->active = GNUNET_YES; return s; } /** * Function called whenever a channel is destroyed. Should clean up * any associated state. * * It must NOT call GNUNET_CADET_channel_destroy on the channel. * * @param cls closure (set from GNUNET_CADET_connect) * @param channel connection to the other end (henceforth invalid) * @param channel_ctx place where local state associated * with the channel is stored */ static void cb_channel_destruction (void *cls, const struct GNUNET_CADET_Channel *channel, void *channel_ctx) { struct ServiceSession * s = channel_ctx; struct ServiceSession * client_session; GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, _ ("Peer disconnected, terminating session %s with peer (%s)\n"), GNUNET_h2s (&s->session_id), GNUNET_i2s (&s->peer)); // as we have only one peer connected in each session, just remove the session s->channel = NULL; if ((ALICE == s->role) && (GNUNET_YES == s->active) && (!do_shutdown)) { // if this happened before we received the answer, we must terminate the session s->role = GNUNET_SYSERR; s->client_notification_task = GNUNET_SCHEDULER_add_now (&prepare_client_end_notification, s); } else if ((BOB == s->role) && (GNUNET_SYSERR != s->active)) { if ((s == from_service_head) || ((NULL != from_service_head) && ((NULL != s->next) || (NULL != s->a_tail)))) GNUNET_CONTAINER_DLL_remove (from_service_head, from_service_tail, s); // there is a client waiting for this service session, terminate it, too! // i assume the tupel of key and element count is unique. if it was not the rest of the code would not work either. client_session = s->response; if ((NULL != s->response ) && (GNUNET_NO == s->active) && (GNUNET_YES == client_session->active)) client_session->active = GNUNET_NO; free_session_variables (s); // the client has to check if it was waiting for a result // or if it was a responder, no point in adding more statefulness if ((NULL != s->response ) && (!do_shutdown)) { client_session->client_notification_task = GNUNET_SCHEDULER_add_now (&prepare_client_end_notification, client_session); } GNUNET_free (s); } } /** * Compute our scalar product, done by Alice * * @param session - the session associated with this computation * @return product as MPI, never NULL */ static gcry_mpi_t compute_scalar_product (struct ServiceSession *session) { uint32_t count; gcry_mpi_t t; gcry_mpi_t u; gcry_mpi_t u_prime; gcry_mpi_t p; gcry_mpi_t p_prime; gcry_mpi_t tmp; gcry_mpi_t r[session->used_element_count]; gcry_mpi_t r_prime[session->used_element_count]; gcry_mpi_t s; gcry_mpi_t s_prime; unsigned int i; count = session->used_element_count; // due to the introduced static offset S, we now also have to remove this // from the E(a_pi)(+)E(-b_pi-r_pi) and E(a_qi)(+)E(-r_qi) twice each, // the result is E((S + a_pi) + (S -b_pi-r_pi)) and E(S + a_qi + S - r_qi) for (i = 0; i < count; i++) { GNUNET_CRYPTO_paillier_decrypt (&my_privkey, &my_pubkey, &session->r[i], r[i]); gcry_mpi_sub (r[i], r[i], my_offset); gcry_mpi_sub (r[i], r[i], my_offset); GNUNET_CRYPTO_paillier_decrypt (&my_privkey, &my_pubkey, &session->r_prime[i], r_prime[i]); gcry_mpi_sub (r_prime[i], r_prime[i], my_offset); gcry_mpi_sub (r_prime[i], r_prime[i], my_offset); } // calculate t = sum(ai) t = compute_square_sum (session->sorted_elements, count); // calculate U u = gcry_mpi_new (0); tmp = compute_square_sum (r, count); gcry_mpi_sub (u, u, tmp); gcry_mpi_release (tmp); //calculate U' u_prime = gcry_mpi_new (0); tmp = compute_square_sum (r_prime, count); gcry_mpi_sub (u_prime, u_prime, tmp); GNUNET_assert (p = gcry_mpi_new (0)); GNUNET_assert (p_prime = gcry_mpi_new (0)); GNUNET_assert (s = gcry_mpi_new (0)); GNUNET_assert (s_prime = gcry_mpi_new (0)); // compute P GNUNET_CRYPTO_paillier_decrypt (&my_privkey, &my_pubkey, session->s, s); GNUNET_CRYPTO_paillier_decrypt (&my_privkey, &my_pubkey, session->s_prime, s_prime); // compute P gcry_mpi_add (p, s, t); gcry_mpi_add (p, p, u); // compute P' gcry_mpi_add (p_prime, s_prime, t); gcry_mpi_add (p_prime, p_prime, u_prime); gcry_mpi_release (t); gcry_mpi_release (u); gcry_mpi_release (u_prime); gcry_mpi_release (s); gcry_mpi_release (s_prime); // compute product gcry_mpi_sub (p, p, p_prime); gcry_mpi_release (p_prime); tmp = gcry_mpi_set_ui (tmp, 2); gcry_mpi_div (p, NULL, p, tmp, 0); gcry_mpi_release (tmp); for (i = 0; i < count; i++) { gcry_mpi_release (session->sorted_elements[i]); gcry_mpi_release (r[i]); gcry_mpi_release (r_prime[i]); } GNUNET_free (session->a_head); session->a_head = NULL; GNUNET_free (session->s); session->s = NULL; GNUNET_free (session->s_prime); session->s_prime = NULL; GNUNET_free (session->r); session->r = NULL; GNUNET_free (session->r_prime); session->r_prime = NULL; return p; } /** * Handle a multipart-chunk of a request from another service to calculate a scalarproduct with us. * * @param cls closure (set from #GNUNET_CADET_connect) * @param channel connection to the other end * @param channel_ctx place to store local state associated with the channel * @param message the actual message * @return #GNUNET_OK to keep the connection open, * #GNUNET_SYSERR to close it (signal serious error) */ static int handle_alices_cyrptodata_message_multipart (void *cls, struct GNUNET_CADET_Channel * channel, void **channel_ctx, const struct GNUNET_MessageHeader * message) { struct ServiceSession * s; const struct MultipartMessage * msg = (const struct MultipartMessage *) message; struct GNUNET_CRYPTO_PaillierCiphertext *payload; uint32_t contained_elements; uint32_t msg_length; // are we in the correct state? s = (struct ServiceSession *) * channel_ctx; //we are not bob if ((NULL == s->e_a) || //or we did not expect this message yet (s->used_element_count == s->transferred_element_count)) { //we are not expecting multipart messages goto except; } // shorter than minimum? if (ntohs (msg->header.size) <= sizeof (struct MultipartMessage)) { goto except; } contained_elements = ntohl (msg->contained_element_count); msg_length = sizeof (struct MultipartMessage) +contained_elements * sizeof (struct GNUNET_CRYPTO_PaillierCiphertext); //sanity check if ((ntohs (msg->header.size) != msg_length) || (s->used_element_count < contained_elements + s->transferred_element_count) || (0 == contained_elements)) { goto except; } payload = (struct GNUNET_CRYPTO_PaillierCiphertext *) &msg[1]; // Convert each vector element to MPI_value memcpy (&s->e_a[s->transferred_element_count], payload, sizeof (struct GNUNET_CRYPTO_PaillierCiphertext) * contained_elements); s->transferred_element_count += contained_elements; if (contained_elements == s->used_element_count) { // single part finished if (NULL == s->intersection_op) // intersection has already finished, so we can proceed compute_service_response (s); } return GNUNET_OK; except: s->channel = NULL; // and notify our client-session that we could not complete the session free_session_variables (s); if (NULL != s->client) { //Alice s->active = GNUNET_SYSERR; s->client_notification_task = GNUNET_SCHEDULER_add_now (&prepare_client_end_notification, s); } else { //Bob if (NULL != s->response){ s->response->active = GNUNET_SYSERR; s->response->client_notification_task = GNUNET_SCHEDULER_add_now (&prepare_client_end_notification, s->response); } if ((s == from_service_head) || ((NULL != from_service_head) && ((NULL != s->next) || (NULL != s->a_tail)))) GNUNET_CONTAINER_DLL_remove (from_service_head, from_service_tail, s); GNUNET_free (s); } return GNUNET_SYSERR; } /** * Handle a request from another service to calculate a scalarproduct with us. * * @param cls closure (set from #GNUNET_CADET_connect) * @param channel connection to the other end * @param channel_ctx place to store local state associated with the channel * @param message the actual message * @return #GNUNET_OK to keep the connection open, * #GNUNET_SYSERR to close it (signal serious error) */ static int handle_alices_cyrptodata_message (void *cls, struct GNUNET_CADET_Channel * channel, void **channel_ctx, const struct GNUNET_MessageHeader * message) { struct ServiceSession * s; const struct AliceCryptodataMessage * msg = (const struct AliceCryptodataMessage *) message; struct GNUNET_CRYPTO_PaillierCiphertext *payload; uint32_t contained_elements = 0; uint32_t msg_length; s = (struct ServiceSession *) * channel_ctx; //we are not bob if ((BOB != s->role) //we are expecting multipart messages instead || (NULL != s->e_a) //or we did not expect this message yet || //intersection OP has not yet finished !((NULL != s->intersection_op) //intersection OP done || (s->response->sorted_elements) )) { goto invalid_msg; } // shorter than minimum? if (ntohs (msg->header.size) <= sizeof (struct MultipartMessage)) { goto invalid_msg; } contained_elements = ntohl (msg->contained_element_count); msg_length = sizeof (struct AliceCryptodataMessage) +contained_elements * sizeof (struct GNUNET_CRYPTO_PaillierCiphertext); //sanity check: is the message as long as the message_count fields suggests? if ((ntohs (msg->header.size) != msg_length) || (s->used_element_count < s->transferred_element_count + contained_elements) || (0 == contained_elements)) { goto invalid_msg; } s->transferred_element_count = contained_elements; payload = (struct GNUNET_CRYPTO_PaillierCiphertext*) &msg[1]; s->e_a = GNUNET_malloc (sizeof (struct GNUNET_CRYPTO_PaillierCiphertext) * s->used_element_count); memcpy (&s->e_a[0], payload, contained_elements * sizeof (struct GNUNET_CRYPTO_PaillierCiphertext)); if (contained_elements == s->used_element_count) { // single part finished if (NULL == s->intersection_op) // intersection has already finished, so we can proceed compute_service_response (s); } return GNUNET_OK; invalid_msg: GNUNET_break_op (0); s->channel = NULL; // and notify our client-session that we could not complete the session free_session_variables (s); if (NULL != s->client) { //Alice s->active = GNUNET_SYSERR; s->client_notification_task = GNUNET_SCHEDULER_add_now (&prepare_client_end_notification, s); } else { //Bob if (NULL != s->response) { s->response->active = GNUNET_SYSERR; s->response->client_notification_task = GNUNET_SCHEDULER_add_now (&prepare_client_end_notification, s->response); } if ((s == from_service_head) || ((NULL != from_service_head) && ((NULL != s->next) || (NULL != s->a_tail)))) GNUNET_CONTAINER_DLL_remove (from_service_head, from_service_tail, s); GNUNET_free(s); } return GNUNET_SYSERR; } /** * Handle a request from another service to calculate a scalarproduct with us. * * @param cls closure (set from #GNUNET_CADET_connect) * @param channel connection to the other end * @param channel_ctx place to store local state associated with the channel * @param message the actual message * @return #GNUNET_OK to keep the connection open, * #GNUNET_SYSERR to close it (signal serious error) */ static int handle_alices_computation_request (void *cls, struct GNUNET_CADET_Channel * channel, void **channel_ctx, const struct GNUNET_MessageHeader * message) { struct ServiceSession * s; struct ServiceSession * client_session; const struct ServiceRequestMessage * msg = (const struct ServiceRequestMessage *) message; s = (struct ServiceSession *) * channel_ctx; if ((BOB != s->role) || (s->total != 0)) { // must be a fresh session goto invalid_msg; } // Check if message was sent by me, which would be bad! if (!memcmp (&s->peer, &me, sizeof (struct GNUNET_PeerIdentity))) { GNUNET_free (s); GNUNET_break (0); return GNUNET_SYSERR; } // shorter than expected? if (ntohs (msg->header.size) != sizeof (struct ServiceRequestMessage)) { GNUNET_free (s); GNUNET_break_op (0); return GNUNET_SYSERR; } if (find_matching_session (from_service_tail, &msg->session_id, NULL)) { GNUNET_log (GNUNET_ERROR_TYPE_ERROR, _ ("Got message with duplicate session key (`%s'), ignoring service request.\n"), (const char *) &(msg->session_id)); GNUNET_free (s); return GNUNET_SYSERR; } s->channel = channel; // session key memcpy (&s->session_id, &msg->session_id, sizeof (struct GNUNET_HashCode)); // public key s->remote_pubkey = GNUNET_new (struct GNUNET_CRYPTO_PaillierPublicKey); memcpy (s->remote_pubkey, &msg->public_key, sizeof (struct GNUNET_CRYPTO_PaillierPublicKey)); //check if service queue contains a matching request client_session = find_matching_session (from_client_tail, &s->session_id, NULL); GNUNET_CONTAINER_DLL_insert (from_service_head, from_service_tail, s); if ((NULL != client_session) && (client_session->transferred_element_count == client_session->total)) { GNUNET_log (GNUNET_ERROR_TYPE_INFO, _("Got session with key %s and a matching element set, processing.\n"), GNUNET_h2s (&s->session_id)); s->response = client_session; s->intersected_elements = client_session->intersected_elements; client_session->intersected_elements = NULL; s->intersection_set = client_session->intersection_set; client_session->intersection_set = NULL; s->intersection_op = GNUNET_SET_prepare (&s->peer, &s->session_id, NULL, GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK, UINT16_MAX), GNUNET_SET_RESULT_REMOVED, cb_intersection_element_removed, s); GNUNET_SET_commit (s->intersection_op, s->intersection_set); } else { GNUNET_log (GNUNET_ERROR_TYPE_INFO, _ ("Got session with key %s without a matching element set, queueing.\n"), GNUNET_h2s (&s->session_id)); } return GNUNET_OK; invalid_msg: GNUNET_break_op (0); s->channel = NULL; // and notify our client-session that we could not complete the session free_session_variables (s); if (NULL != s->client) { //Alice s->active = GNUNET_SYSERR; s->client_notification_task = GNUNET_SCHEDULER_add_now (&prepare_client_end_notification, s); } else { //Bob if (NULL != s->response) { s->response->active = GNUNET_SYSERR; s->response->client_notification_task = GNUNET_SCHEDULER_add_now (&prepare_client_end_notification, s->response); } if ((s == from_service_head) || ((NULL != from_service_head) && ((NULL != s->next) || (NULL != s->a_tail)))) GNUNET_CONTAINER_DLL_remove (from_service_head, from_service_tail, s); GNUNET_free(s); } return GNUNET_SYSERR; } /** * Handle a multipart chunk of a response we got from another service we wanted to calculate a scalarproduct with. * * @param cls closure (set from #GNUNET_CADET_connect) * @param channel connection to the other end * @param channel_ctx place to store local state associated with the channel * @param message the actual message * @return #GNUNET_OK to keep the connection open, * #GNUNET_SYSERR to close it (signal serious error) */ static int handle_bobs_cryptodata_multipart (void *cls, struct GNUNET_CADET_Channel * channel, void **channel_ctx, const struct GNUNET_MessageHeader * message) { struct ServiceSession * s; const struct MultipartMessage * msg = (const struct MultipartMessage *) message; struct GNUNET_CRYPTO_PaillierCiphertext * payload; size_t i; uint32_t contained = 0; size_t msg_size; size_t required_size; GNUNET_assert (NULL != message); // are we in the correct state? s = (struct ServiceSession *) * channel_ctx; if ((ALICE != s->role) || (NULL == s->sorted_elements)) { goto invalid_msg; } msg_size = ntohs (msg->header.size); required_size = sizeof (struct MultipartMessage) + 2 * sizeof (struct GNUNET_CRYPTO_PaillierCiphertext); // shorter than minimum? if (required_size > msg_size) { goto invalid_msg; } contained = ntohl (msg->contained_element_count); required_size = sizeof (struct MultipartMessage) + 2 * contained * sizeof (struct GNUNET_CRYPTO_PaillierCiphertext); //sanity check: is the message as long as the message_count fields suggests? if ((required_size != msg_size) || (s->used_element_count < s->transferred_element_count + contained)) { goto invalid_msg; } payload = (struct GNUNET_CRYPTO_PaillierCiphertext *) &msg[1]; // Convert each k[][perm] to its MPI_value for (i = 0; i < contained; i++) { memcpy (&s->r[s->transferred_element_count + i], &payload[2 * i], sizeof (struct GNUNET_CRYPTO_PaillierCiphertext)); memcpy (&s->r_prime[s->transferred_element_count + i], &payload[2 * i], sizeof (struct GNUNET_CRYPTO_PaillierCiphertext)); } s->transferred_element_count += contained; if (s->transferred_element_count != s->used_element_count) return GNUNET_OK; s->product = compute_scalar_product (s); //never NULL invalid_msg: GNUNET_break_op (NULL != s->product); s->channel = NULL; // send message with product to client if (NULL != s->client) { //Alice if (NULL != s->product) s->active = GNUNET_NO; else s->active = GNUNET_SYSERR; s->client_notification_task = GNUNET_SCHEDULER_add_now (&prepare_client_response, s); } else { //Bob if (NULL != s->response){ s->response->active = GNUNET_SYSERR; s->response->client_notification_task = GNUNET_SCHEDULER_add_now (&prepare_client_end_notification, s->response); } if ((s == from_service_head) || ((NULL != from_service_head) && ((NULL != s->next) || (NULL != s->a_tail)))) GNUNET_CONTAINER_DLL_remove (from_service_head, from_service_tail, s); free_session_variables (s); GNUNET_free(s); } // the channel has done its job, terminate our connection and the channel // the peer will be notified that the channel was destroyed via channel_destruction_handler // just close the connection, as recommended by Christian return GNUNET_SYSERR; } /** * Handle a response we got from another service we wanted to calculate a scalarproduct with. * * @param cls closure (set from #GNUNET_CADET_connect) * @param channel connection to the other end * @param channel_ctx place to store local state associated with the channel * @param message the actual message * @return #GNUNET_OK to keep the connection open, * #GNUNET_SYSERR to close it (we are done) */ static int handle_bobs_cryptodata_message (void *cls, struct GNUNET_CADET_Channel *channel, void **channel_ctx, const struct GNUNET_MessageHeader *message) { struct ServiceSession * s; const struct ServiceResponseMessage *msg = (const struct ServiceResponseMessage *) message; struct GNUNET_CRYPTO_PaillierCiphertext * payload; size_t i; uint32_t contained = 0; size_t msg_size; size_t required_size; GNUNET_assert (NULL != message); s = (struct ServiceSession *) * channel_ctx; // are we in the correct state? if (NULL == s->sorted_elements || NULL != s->msg || s->used_element_count != s->transferred_element_count) { goto invalid_msg; } //we need at least a full message without elements attached msg_size = ntohs (msg->header.size); required_size = sizeof (struct ServiceResponseMessage) + 2 * sizeof (struct GNUNET_CRYPTO_PaillierCiphertext); if (required_size > msg_size) { goto invalid_msg; } contained = ntohl (msg->contained_element_count); required_size = sizeof (struct ServiceResponseMessage) + 2 * contained * sizeof (struct GNUNET_CRYPTO_PaillierCiphertext) + 2 * sizeof (struct GNUNET_CRYPTO_PaillierCiphertext); //sanity check: is the message as long as the message_count fields suggests? if ((msg_size != required_size) || (s->used_element_count < contained)) { goto invalid_msg; } s->transferred_element_count = contained; //convert s payload = (struct GNUNET_CRYPTO_PaillierCiphertext *) &msg[1]; s->s = GNUNET_malloc (sizeof (struct GNUNET_CRYPTO_PaillierCiphertext)); s->s_prime = GNUNET_malloc (sizeof (struct GNUNET_CRYPTO_PaillierCiphertext)); memcpy (s->s, &payload[0], sizeof (struct GNUNET_CRYPTO_PaillierCiphertext)); memcpy (s->s_prime, &payload[1], sizeof (struct GNUNET_CRYPTO_PaillierCiphertext)); s->r = GNUNET_malloc (sizeof (struct GNUNET_CRYPTO_PaillierCiphertext) * s->used_element_count); s->r_prime = GNUNET_malloc (sizeof (struct GNUNET_CRYPTO_PaillierCiphertext) * s->used_element_count); payload = &payload[2]; // Convert each k[][perm] to its MPI_value for (i = 0; i < contained; i++) { memcpy (&s->r[i], &payload[2 * i], sizeof (struct GNUNET_CRYPTO_PaillierCiphertext)); memcpy (&s->r_prime[i], &payload[2 * i + 1], sizeof (struct GNUNET_CRYPTO_PaillierCiphertext)); } if (s->transferred_element_count != s->used_element_count) return GNUNET_OK; //wait for the other multipart chunks s->product = compute_scalar_product (s); //never NULL invalid_msg: GNUNET_break_op (NULL != s->product); s->channel = NULL; // send message with product to client if (NULL != s->client) { //Alice s->client_notification_task = GNUNET_SCHEDULER_add_now (&prepare_client_response, s); } else { //Bob if (NULL != s->response) { s->response->active = GNUNET_SYSERR; s->response->client_notification_task = GNUNET_SCHEDULER_add_now (&prepare_client_end_notification, s->response); } if ((s == from_service_head) || ((NULL != from_service_head) && ((NULL != s->next) || (NULL != s->a_tail)))) GNUNET_CONTAINER_DLL_remove (from_service_head, from_service_tail, s); free_session_variables (s); GNUNET_free(s); } // the channel has done its job, terminate our connection and the channel // the peer will be notified that the channel was destroyed via channel_destruction_handler // just close the connection, as recommended by Christian return GNUNET_SYSERR; } /** * Task run during shutdown. * * @param cls unused * @param tc unused */ static void shutdown_task (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc) { struct ServiceSession * s; GNUNET_log (GNUNET_ERROR_TYPE_INFO, _("Shutting down, initiating cleanup.\n")); do_shutdown = GNUNET_YES; // terminate all owned open channels. for (s = from_client_head; NULL != s; s = s->next) { if ((GNUNET_NO != s->active) && (NULL != s->channel)) { GNUNET_CADET_channel_destroy (s->channel); s->channel = NULL; } if (GNUNET_SCHEDULER_NO_TASK != s->client_notification_task) { GNUNET_SCHEDULER_cancel (s->client_notification_task); s->client_notification_task = GNUNET_SCHEDULER_NO_TASK; } if (NULL != s->client) { GNUNET_SERVER_client_disconnect (s->client); s->client = NULL; } } for (s = from_service_head; NULL != s; s = s->next) if (NULL != s->channel) { GNUNET_CADET_channel_destroy (s->channel); s->channel = NULL; } if (my_cadet) { GNUNET_CADET_disconnect (my_cadet); my_cadet = NULL; } } /** * Initialization of the program and message handlers * * @param cls closure * @param server the initialized server * @param c configuration to use */ static void run (void *cls, struct GNUNET_SERVER_Handle *server, const struct GNUNET_CONFIGURATION_Handle *c) { static const struct GNUNET_SERVER_MessageHandler server_handlers[] = { {&handle_client_message, NULL, GNUNET_MESSAGE_TYPE_SCALARPRODUCT_CLIENT_TO_ALICE, 0}, {&handle_client_message, NULL, GNUNET_MESSAGE_TYPE_SCALARPRODUCT_CLIENT_TO_BOB, 0}, {&handle_client_message_multipart, NULL, GNUNET_MESSAGE_TYPE_SCALARPRODUCT_CLIENT_MUTLIPART, 0}, {NULL, NULL, 0, 0} }; static const struct GNUNET_CADET_MessageHandler cadet_handlers[] = { { &handle_alices_computation_request, GNUNET_MESSAGE_TYPE_SCALARPRODUCT_SESSION_INITIALIZATION, 0}, { &handle_alices_cyrptodata_message, GNUNET_MESSAGE_TYPE_SCALARPRODUCT_ALICE_CRYPTODATA, 0}, { &handle_alices_cyrptodata_message_multipart, GNUNET_MESSAGE_TYPE_SCALARPRODUCT_ALICE_CRYPTODATA_MULTIPART, 0}, { &handle_bobs_cryptodata_message, GNUNET_MESSAGE_TYPE_SCALARPRODUCT_BOB_CRYPTODATA, 0}, { &handle_bobs_cryptodata_multipart, GNUNET_MESSAGE_TYPE_SCALARPRODUCT_BOB_CRYPTODATA_MULTIPART, 0}, {NULL, 0, 0} }; static const uint32_t ports[] = { GNUNET_APPLICATION_TYPE_SCALARPRODUCT, 0 }; cfg = c; //generate private/public key set GNUNET_CRYPTO_paillier_create (&my_pubkey, &my_privkey); // offset has to be sufficiently small to allow computation of: // m1+m2 mod n == (S + a) + (S + b) mod n, // if we have more complex operations, this factor needs to be lowered my_offset = gcry_mpi_new (GNUNET_CRYPTO_PAILLIER_BITS / 3); gcry_mpi_set_bit (my_offset, GNUNET_CRYPTO_PAILLIER_BITS / 3); // register server callbacks and disconnect handler GNUNET_SERVER_add_handlers (server, server_handlers); GNUNET_SERVER_disconnect_notify (server, &cb_client_disconnect, NULL); GNUNET_break (GNUNET_OK == GNUNET_CRYPTO_get_peer_identity (cfg, &me)); my_cadet = GNUNET_CADET_connect (cfg, NULL, &cb_channel_incoming, &cb_channel_destruction, cadet_handlers, ports); if (!my_cadet) { GNUNET_log (GNUNET_ERROR_TYPE_ERROR, _("Connect to CADET failed\n")); GNUNET_SCHEDULER_shutdown (); return; } GNUNET_log (GNUNET_ERROR_TYPE_INFO, _("CADET initialized\n")); GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_FOREVER_REL, &shutdown_task, NULL); } /** * The main function for the scalarproduct service. * * @param argc number of arguments from the command line * @param argv command line arguments * @return 0 ok, 1 on error */ int main (int argc, char *const *argv) { return (GNUNET_OK == GNUNET_SERVICE_run (argc, argv, "scalarproduct", GNUNET_SERVICE_OPTION_NONE, &run, NULL)) ? 0 : 1; } /* end of gnunet-service-scalarproduct.c */