2 This file is part of GNUnet.
3 Copyright (C) 2013 GNUnet e.V.
5 GNUnet is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published
7 by the Free Software Foundation; either version 3, or (at your
8 option) any later version.
10 GNUnet is distributed in the hope that it will be useful, but
11 WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 General Public License for more details.
15 You should have received a copy of the GNU General Public License
16 along with GNUnet; see the file COPYING. If not, write to the
17 Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
18 Boston, MA 02110-1301, USA.
22 * @file secretsharing/gnunet-service-secretsharing.c
23 * @brief secret sharing service
24 * @author Florian Dold
27 #include "gnunet_util_lib.h"
28 #include "gnunet_time_lib.h"
29 #include "gnunet_signatures.h"
30 #include "gnunet_consensus_service.h"
31 #include "secretsharing.h"
32 #include "secretsharing_protocol.h"
36 #define EXTRA_CHECKS 1
40 * Info about a peer in a key generation session.
45 * Peer identity of the peer.
47 struct GNUNET_PeerIdentity peer;
50 * The peer's paillier public key.
51 * Freshly generated for each keygen session.
53 struct GNUNET_CRYPTO_PaillierPublicKey paillier_public_key;
56 * The peer's commitment to his presecret.
58 gcry_mpi_t presecret_commitment;
61 * Commitment to the preshare that is
62 * intended for our peer.
64 gcry_mpi_t preshare_commitment;
67 * Sigma (exponentiated share) for this peer.
72 * Did we successfully receive the round1 element
78 * Did we successfully receive the round2 element
86 * Information about a peer in a decrypt session.
88 struct DecryptPeerInfo
91 * Identity of the peer.
93 struct GNUNET_PeerIdentity peer;
96 * Original index in the key generation round.
97 * Necessary for computing the lagrange coefficients.
99 unsigned int original_index;
102 * Set to the partial decryption of
103 * this peer, or NULL if we did not
104 * receive a partial decryption from this
105 * peer or the zero knowledge proof failed.
107 gcry_mpi_t partial_decryption;
112 * Session to establish a threshold-shared secret.
117 * Keygen sessions are held in a linked list.
119 struct KeygenSession *next;
122 * Keygen sessions are held in a linked list.
124 struct KeygenSession *prev;
127 * Current consensus, used for both DKG rounds.
129 struct GNUNET_CONSENSUS_Handle *consensus;
132 * Client that is interested in the result
133 * of this key generation session.
135 struct GNUNET_SERVER_Client *client;
138 * Message queue for 'client'
140 struct GNUNET_MQ_Handle *client_mq;
143 * Randomly generated coefficients of the polynomial for sharing our
144 * pre-secret, where 'preshares[0]' is our pre-secret. Contains 'threshold'
145 * elements, thus represents a polynomial of degree 'threshold-1', which can
146 * be interpolated with 'threshold' data points.
148 * The pre-secret-shares 'i=1,...,num_peers' are given by evaluating this
149 * polyomial at 'i' for share i.
151 gcry_mpi_t *presecret_polynomial;
154 * Minimum number of shares required to restore the secret.
155 * Also the number of coefficients for the polynomial representing
156 * the sharing. Obviously, the polynomial then has degree threshold-1.
158 unsigned int threshold;
161 * Total number of peers.
163 unsigned int num_peers;
166 * Index of the local peer.
168 unsigned int local_peer;
171 * Information about all participating peers.
172 * Array of size 'num_peers'.
174 struct KeygenPeerInfo *info;
177 * List of all peers involved in the secret sharing session.
179 struct GNUNET_PeerIdentity *peers;
182 * Identifier for this session.
184 struct GNUNET_HashCode session_id;
187 * Paillier private key of our peer.
189 struct GNUNET_CRYPTO_PaillierPrivateKey paillier_private_key;
192 * When would we like the key to be established?
194 struct GNUNET_TIME_Absolute deadline;
197 * When does the DKG start? Necessary to compute fractions of the
198 * operation's desired time interval.
200 struct GNUNET_TIME_Absolute start_time;
203 * Index of the local peer in the ordered list
204 * of peers in the session.
206 unsigned int local_peer_idx;
209 * Share of our peer. Once preshares from other peers are received, they
210 * will be added to 'my'share.
215 * Public key, will be updated when a round2 element arrives.
217 gcry_mpi_t public_key;
222 * Session to cooperatively decrypt a value.
224 struct DecryptSession
227 * Decrypt sessions are stored in a linked list.
229 struct DecryptSession *next;
232 * Decrypt sessions are stored in a linked list.
234 struct DecryptSession *prev;
237 * Handle to the consensus over partial decryptions.
239 struct GNUNET_CONSENSUS_Handle *consensus;
242 * Client connected to us.
244 struct GNUNET_SERVER_Client *client;
247 * Message queue for 'client'.
249 struct GNUNET_MQ_Handle *client_mq;
252 * When should we start communicating for decryption?
254 struct GNUNET_TIME_Absolute start;
257 * When would we like the ciphertext to be
260 struct GNUNET_TIME_Absolute deadline;
263 * Ciphertext we want to decrypt.
265 struct GNUNET_SECRETSHARING_Ciphertext ciphertext;
268 * Share of the local peer.
269 * Containts other important information, such as
270 * the list of other peers.
272 struct GNUNET_SECRETSHARING_Share *share;
275 * State information about other peers.
277 struct DecryptPeerInfo *info;
282 * Decrypt sessions are held in a linked list.
284 static struct DecryptSession *decrypt_sessions_head;
287 * Decrypt sessions are held in a linked list.
289 static struct DecryptSession *decrypt_sessions_tail;
292 * Decrypt sessions are held in a linked list.
294 static struct KeygenSession *keygen_sessions_head;
297 * Decrypt sessions are held in a linked list.
299 static struct KeygenSession *keygen_sessions_tail;
302 * The ElGamal prime field order as libgcrypt mpi.
303 * Initialized in #init_crypto_constants.
305 static gcry_mpi_t elgamal_q;
308 * Modulus of the prime field used for ElGamal.
309 * Initialized in #init_crypto_constants.
311 static gcry_mpi_t elgamal_p;
314 * Generator for prime field of order 'elgamal_q'.
315 * Initialized in #init_crypto_constants.
317 static gcry_mpi_t elgamal_g;
320 * Peer that runs this service.
322 static struct GNUNET_PeerIdentity my_peer;
325 * Peer that runs this service.
327 static struct GNUNET_CRYPTO_EddsaPrivateKey *my_peer_private_key;
330 * Configuration of this service.
332 static const struct GNUNET_CONFIGURATION_Handle *cfg;
335 * Server for this service.
337 static struct GNUNET_SERVER_Handle *srv;
341 * Get the peer info belonging to a peer identity in a keygen session.
343 * @param ks The keygen session.
344 * @param peer The peer identity.
345 * @return The Keygen peer info, or NULL if the peer could not be found.
347 static struct KeygenPeerInfo *
348 get_keygen_peer_info (const struct KeygenSession *ks,
349 const struct GNUNET_PeerIdentity *peer)
352 for (i = 0; i < ks->num_peers; i++)
353 if (0 == memcmp (peer, &ks->info[i].peer, sizeof (struct GNUNET_PeerIdentity)))
360 * Get the peer info belonging to a peer identity in a decrypt session.
362 * @param ds The decrypt session.
363 * @param peer The peer identity.
364 * @return The decrypt peer info, or NULL if the peer could not be found.
366 static struct DecryptPeerInfo *
367 get_decrypt_peer_info (const struct DecryptSession *ds,
368 const struct GNUNET_PeerIdentity *peer)
371 for (i = 0; i < ds->share->num_peers; i++)
372 if (0 == memcmp (peer, &ds->info[i].peer, sizeof (struct GNUNET_PeerIdentity)))
379 * Interpolate between two points in time.
381 * @param start start time
382 * @param end end time
383 * @param num numerator of the scale factor
384 * @param denum denumerator of the scale factor
386 static struct GNUNET_TIME_Absolute
387 time_between (struct GNUNET_TIME_Absolute start,
388 struct GNUNET_TIME_Absolute end,
391 struct GNUNET_TIME_Absolute result;
394 GNUNET_assert (start.abs_value_us <= end.abs_value_us);
395 diff = end.abs_value_us - start.abs_value_us;
396 result.abs_value_us = start.abs_value_us + ((diff * num) / denum);
403 * Compare two peer identities. Indended to be used with qsort or bsearch.
405 * @param p1 Some peer identity.
406 * @param p2 Some peer identity.
407 * @return 1 if p1 > p2, -1 if p1 < p2 and 0 if p1 == p2.
410 peer_id_cmp (const void *p1, const void *p2)
414 sizeof (struct GNUNET_PeerIdentity));
419 * Get the index of a peer in an array of peers
421 * @param haystack Array of peers.
422 * @param n Size of @a haystack.
423 * @param needle Peer to find
424 * @return Index of @a needle in @a haystack, or -1 if peer
425 * is not in the list.
428 peer_find (const struct GNUNET_PeerIdentity *haystack, unsigned int n,
429 const struct GNUNET_PeerIdentity *needle)
433 for (i = 0; i < n; i++)
434 if (0 == memcmp (&haystack[i],
436 sizeof (struct GNUNET_PeerIdentity)))
443 * Normalize the given list of peers, by including the local peer
444 * (if it is missing) and sorting the peers by their identity.
446 * @param listed Peers in the unnormalized list.
447 * @param num_listed Peers in the un-normalized list.
448 * @param[out] num_normalized Number of peers in the normalized list.
449 * @param[out] my_peer_idx Index of the local peer in the normalized list.
450 * @return Normalized list, must be free'd by the caller.
452 static struct GNUNET_PeerIdentity *
453 normalize_peers (struct GNUNET_PeerIdentity *listed,
454 unsigned int num_listed,
455 unsigned int *num_normalized,
456 unsigned int *my_peer_idx)
458 unsigned int local_peer_in_list;
459 /* number of peers in the normalized list */
461 struct GNUNET_PeerIdentity *normalized;
463 local_peer_in_list = GNUNET_YES;
465 if (peer_find (listed, num_listed, &my_peer) < 0)
467 local_peer_in_list = GNUNET_NO;
471 normalized = GNUNET_new_array (n, struct GNUNET_PeerIdentity);
473 if (GNUNET_NO == local_peer_in_list)
474 normalized[n - 1] = my_peer;
476 GNUNET_memcpy (normalized,
478 num_listed * sizeof (struct GNUNET_PeerIdentity));
481 sizeof (struct GNUNET_PeerIdentity),
484 if (NULL != my_peer_idx)
485 *my_peer_idx = peer_find (normalized, n, &my_peer);
486 if (NULL != num_normalized)
494 * Get a the j-th lagrange coefficient for a set of indices.
496 * @param[out] coeff the lagrange coefficient
497 * @param j lagrange coefficient we want to compute
498 * @param indices indices
499 * @param num number of indices in @a indices
502 compute_lagrange_coefficient (gcry_mpi_t coeff, unsigned int j,
503 unsigned int *indices,
511 /* temp value for l-j */
514 GNUNET_assert (0 != coeff);
516 GNUNET_assert (0 != (n = gcry_mpi_new (0)));
517 GNUNET_assert (0 != (d = gcry_mpi_new (0)));
518 GNUNET_assert (0 != (tmp = gcry_mpi_new (0)));
520 gcry_mpi_set_ui (n, 1);
521 gcry_mpi_set_ui (d, 1);
523 for (i = 0; i < num; i++)
525 unsigned int l = indices[i];
528 gcry_mpi_mul_ui (n, n, l + 1);
530 gcry_mpi_set_ui (tmp, l + 1);
531 gcry_mpi_sub_ui (tmp, tmp, j + 1);
532 gcry_mpi_mul (d, d, tmp);
535 // gcry_mpi_invm does not like negative numbers ...
536 gcry_mpi_mod (d, d, elgamal_q);
538 GNUNET_assert (gcry_mpi_cmp_ui (d, 0) > 0);
540 // now we do the actual division, with everything mod q, as we
541 // are not operating on elements from <g>, but on exponents
542 GNUNET_assert (0 != gcry_mpi_invm (d, d, elgamal_q));
544 gcry_mpi_mulm (coeff, n, d, elgamal_q);
546 gcry_mpi_release (n);
547 gcry_mpi_release (d);
548 gcry_mpi_release (tmp);
553 * Destroy a decrypt session, removing it from
554 * the linked list of decrypt sessions.
556 * @param ds decrypt session to destroy
559 decrypt_session_destroy (struct DecryptSession *ds)
561 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "destroying decrypt session\n");
563 GNUNET_CONTAINER_DLL_remove (decrypt_sessions_head, decrypt_sessions_tail, ds);
565 if (NULL != ds->consensus)
567 GNUNET_CONSENSUS_destroy (ds->consensus);
568 ds->consensus = NULL;
571 if (NULL != ds->info)
574 for (i = 0; i < ds->share->num_peers; i++)
576 if (NULL != ds->info[i].partial_decryption)
578 gcry_mpi_release (ds->info[i].partial_decryption);
579 ds->info[i].partial_decryption = NULL;
582 GNUNET_free (ds->info);
586 if (NULL != ds->share)
588 GNUNET_SECRETSHARING_share_destroy (ds->share);
592 if (NULL != ds->client_mq)
594 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "destroying decrypt MQ\n");
595 GNUNET_MQ_destroy (ds->client_mq);
596 ds->client_mq = NULL;
599 if (NULL != ds->client)
601 GNUNET_SERVER_client_disconnect (ds->client);
610 keygen_info_destroy (struct KeygenPeerInfo *info)
612 if (NULL != info->sigma)
614 gcry_mpi_release (info->sigma);
617 if (NULL != info->presecret_commitment)
619 gcry_mpi_release (info->presecret_commitment);
620 info->presecret_commitment = NULL;
622 if (NULL != info->preshare_commitment)
624 gcry_mpi_release (info->preshare_commitment);
625 info->preshare_commitment = NULL;
631 keygen_session_destroy (struct KeygenSession *ks)
633 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "destroying keygen session\n");
635 GNUNET_CONTAINER_DLL_remove (keygen_sessions_head, keygen_sessions_tail, ks);
637 if (NULL != ks->info)
640 for (i = 0; i < ks->num_peers; i++)
641 keygen_info_destroy (&ks->info[i]);
642 GNUNET_free (ks->info);
646 if (NULL != ks->consensus)
648 GNUNET_CONSENSUS_destroy (ks->consensus);
649 ks->consensus = NULL;
652 if (NULL != ks->presecret_polynomial)
655 for (i = 0; i < ks->threshold; i++)
657 GNUNET_assert (NULL != ks->presecret_polynomial[i]);
658 gcry_mpi_release (ks->presecret_polynomial[i]);
659 ks->presecret_polynomial[i] = NULL;
661 GNUNET_free (ks->presecret_polynomial);
662 ks->presecret_polynomial = NULL;
665 if (NULL != ks->client_mq)
667 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "destroying keygen MQ\n");
668 GNUNET_MQ_destroy (ks->client_mq);
669 ks->client_mq = NULL;
672 if (NULL != ks->my_share)
674 gcry_mpi_release (ks->my_share);
678 if (NULL != ks->public_key)
680 gcry_mpi_release (ks->public_key);
681 ks->public_key = NULL;
684 if (NULL != ks->peers)
686 GNUNET_free (ks->peers);
690 if (NULL != ks->client)
692 GNUNET_SERVER_client_disconnect (ks->client);
701 * Task run during shutdown.
707 cleanup_task (void *cls)
709 while (NULL != decrypt_sessions_head)
710 decrypt_session_destroy (decrypt_sessions_head);
712 while (NULL != keygen_sessions_head)
713 keygen_session_destroy (keygen_sessions_head);
719 * Generate the random coefficients of our pre-secret polynomial
721 * @param ks the session
724 generate_presecret_polynomial (struct KeygenSession *ks)
729 GNUNET_assert (NULL == ks->presecret_polynomial);
730 ks->presecret_polynomial = GNUNET_new_array (ks->threshold, gcry_mpi_t);
731 for (i = 0; i < ks->threshold; i++)
733 v = ks->presecret_polynomial[i] = gcry_mpi_new (GNUNET_SECRETSHARING_ELGAMAL_BITS);
734 GNUNET_assert (NULL != v);
735 // Randomize v such that 0 < v < elgamal_q.
736 // The '- 1' is necessary as bitlength(q) = bitlength(p) - 1.
739 gcry_mpi_randomize (v, GNUNET_SECRETSHARING_ELGAMAL_BITS - 1, GCRY_WEAK_RANDOM);
740 } while ((gcry_mpi_cmp_ui (v, 0) == 0) || (gcry_mpi_cmp (v, elgamal_q) >= 0));
746 * Consensus element handler for round one.
747 * We should get one ephemeral key for each peer.
749 * @param cls Closure (keygen session).
750 * @param element The element from consensus, or
751 * NULL if consensus failed.
754 keygen_round1_new_element (void *cls,
755 const struct GNUNET_SET_Element *element)
757 const struct GNUNET_SECRETSHARING_KeygenCommitData *d;
758 struct KeygenSession *ks = cls;
759 struct KeygenPeerInfo *info;
763 GNUNET_log (GNUNET_ERROR_TYPE_WARNING, "round1 consensus failed\n");
767 /* elements have fixed size */
768 if (element->size != sizeof (struct GNUNET_SECRETSHARING_KeygenCommitData))
770 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
771 "keygen commit data with wrong size (%u) in consensus, "
773 element->size, sizeof (struct GNUNET_SECRETSHARING_KeygenCommitData));
777 GNUNET_log (GNUNET_ERROR_TYPE_INFO, "got round1 element\n");
780 info = get_keygen_peer_info (ks, &d->peer);
784 GNUNET_log (GNUNET_ERROR_TYPE_WARNING, "keygen commit data with wrong peer identity (%s) in consensus\n",
785 GNUNET_i2s (&d->peer));
789 /* Check that the right amount of data has been signed. */
790 if (d->purpose.size !=
791 htonl (element->size - offsetof (struct GNUNET_SECRETSHARING_KeygenCommitData, purpose)))
793 GNUNET_log (GNUNET_ERROR_TYPE_WARNING, "keygen commit data with wrong signature purpose size in consensus\n");
797 if (GNUNET_OK != GNUNET_CRYPTO_eddsa_verify (GNUNET_SIGNATURE_PURPOSE_SECRETSHARING_DKG1,
798 &d->purpose, &d->signature, &d->peer.public_key))
800 GNUNET_log (GNUNET_ERROR_TYPE_WARNING, "keygen commit data with invalid signature in consensus\n");
803 info->paillier_public_key = d->pubkey;
804 GNUNET_CRYPTO_mpi_scan_unsigned (&info->presecret_commitment, &d->commitment, 512 / 8);
805 info->round1_valid = GNUNET_YES;
810 * Evaluate the polynomial with coefficients @a coeff at @a x.
811 * The i-th element in @a coeff corresponds to the coefficient of x^i.
813 * @param[out] z result of the evaluation
814 * @param coeff array of coefficients
815 * @param num_coeff number of coefficients
816 * @param x where to evaluate the polynomial
817 * @param m what group are we operating in?
820 horner_eval (gcry_mpi_t z, gcry_mpi_t *coeff, unsigned int num_coeff, gcry_mpi_t x, gcry_mpi_t m)
824 gcry_mpi_set_ui (z, 0);
825 for (i = 0; i < num_coeff; i++)
828 gcry_mpi_mul (z, z, x);
829 gcry_mpi_addm (z, z, coeff[num_coeff - i - 1], m);
835 keygen_round2_conclude (void *cls)
837 struct KeygenSession *ks = cls;
838 struct GNUNET_SECRETSHARING_SecretReadyMessage *m;
839 struct GNUNET_MQ_Envelope *ev;
843 struct GNUNET_SECRETSHARING_Share *share;
845 GNUNET_log (GNUNET_ERROR_TYPE_INFO, "round2 conclude\n");
847 GNUNET_CONSENSUS_destroy (ks->consensus);
848 ks->consensus = NULL;
850 share = GNUNET_new (struct GNUNET_SECRETSHARING_Share);
852 share->num_peers = 0;
854 for (i = 0; i < ks->num_peers; i++)
855 if (GNUNET_YES == ks->info[i].round2_valid)
858 share->peers = GNUNET_new_array (share->num_peers, struct GNUNET_PeerIdentity);
860 GNUNET_new_array (share->num_peers, struct GNUNET_SECRETSHARING_FieldElement);
861 share->original_indices = GNUNET_new_array (share->num_peers, uint16_t);
863 /* maybe we're not even in the list of peers? */
864 share->my_peer = share->num_peers;
866 j = 0; /* running index of valid peers */
867 for (i = 0; i < ks->num_peers; i++)
869 if (GNUNET_YES == ks->info[i].round2_valid)
871 share->peers[j] = ks->info[i].peer;
872 GNUNET_CRYPTO_mpi_print_unsigned (&share->sigmas[j],
873 GNUNET_SECRETSHARING_ELGAMAL_BITS / 8,
875 share->original_indices[i] = j;
876 if (0 == memcmp (&share->peers[i], &my_peer, sizeof (struct GNUNET_PeerIdentity)))
882 if (share->my_peer == share->num_peers)
884 GNUNET_log (GNUNET_ERROR_TYPE_INFO, "P%u: peer identity not in share\n", ks->local_peer_idx);
887 GNUNET_CRYPTO_mpi_print_unsigned (&share->my_share, GNUNET_SECRETSHARING_ELGAMAL_BITS / 8,
889 GNUNET_CRYPTO_mpi_print_unsigned (&share->public_key, GNUNET_SECRETSHARING_ELGAMAL_BITS / 8,
892 GNUNET_log (GNUNET_ERROR_TYPE_INFO, "keygen completed with %u peers\n", share->num_peers);
894 /* Write the share. If 0 peers completed the dkg, an empty
895 * share will be sent. */
897 GNUNET_assert (GNUNET_OK == GNUNET_SECRETSHARING_share_write (share, NULL, 0, &share_size));
899 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "writing share of size %u\n",
900 (unsigned int) share_size);
902 ev = GNUNET_MQ_msg_extra (m, share_size,
903 GNUNET_MESSAGE_TYPE_SECRETSHARING_CLIENT_SECRET_READY);
905 GNUNET_assert (GNUNET_OK == GNUNET_SECRETSHARING_share_write (share, &m[1], share_size, NULL));
907 GNUNET_SECRETSHARING_share_destroy (share);
910 GNUNET_MQ_send (ks->client_mq, ev);
916 restore_fair (const struct GNUNET_CRYPTO_PaillierPublicKey *ppub,
917 const struct GNUNET_SECRETSHARING_FairEncryption *fe,
918 gcry_mpi_t x, gcry_mpi_t xres)
935 GNUNET_assert (NULL != (n = gcry_mpi_new (0)));
936 GNUNET_assert (NULL != (t = gcry_mpi_new (0)));
937 GNUNET_assert (NULL != (t_1 = gcry_mpi_new (0)));
938 GNUNET_assert (NULL != (t_2 = gcry_mpi_new (0)));
939 GNUNET_assert (NULL != (r = gcry_mpi_new (0)));
940 GNUNET_assert (NULL != (big_t = gcry_mpi_new (0)));
941 GNUNET_assert (NULL != (v = gcry_mpi_new (0)));
942 GNUNET_assert (NULL != (big_a = gcry_mpi_new (0)));
943 GNUNET_assert (NULL != (big_b = gcry_mpi_new (0)));
946 GNUNET_CRYPTO_mpi_scan_unsigned (&a_1, ppub, sizeof (struct GNUNET_CRYPTO_PaillierPublicKey));
947 GNUNET_assert (NULL != (a_2 = gcry_mpi_new (0)));
948 gcry_mpi_set_ui (a_2, 0);
950 GNUNET_assert (NULL != (b_1 = gcry_mpi_new (0)));
951 gcry_mpi_set (b_1, x);
952 GNUNET_assert (NULL != (b_2 = gcry_mpi_new (0)));
953 gcry_mpi_set_ui (b_2, 1);
956 gcry_mpi_mul (t, a_1, a_1);
957 gcry_mpi_mul (big_a, a_2, a_2);
958 gcry_mpi_add (big_a, big_a, t);
961 gcry_mpi_mul (t, b_1, b_1);
962 gcry_mpi_mul (big_b, b_2, b_2);
963 gcry_mpi_add (big_b, big_b, t);
968 gcry_mpi_mul (t, a_1, b_1);
969 gcry_mpi_mul (n, a_2, b_2);
970 gcry_mpi_add (n, n, t);
973 gcry_mpi_div (r, NULL, n, big_b, 0);
975 // T := A - 2rn + rrB
976 gcry_mpi_mul (v, r, n);
977 gcry_mpi_mul_ui (v, v, 2);
978 gcry_mpi_sub (big_t, big_a, v);
979 gcry_mpi_mul (v, r, r);
980 gcry_mpi_mul (v, v, big_b);
981 gcry_mpi_add (big_t, big_t, v);
983 if (gcry_mpi_cmp (big_t, big_b) >= 0)
989 gcry_mpi_mul (v, r, b_1);
990 gcry_mpi_sub (t_1, a_1, v);
991 gcry_mpi_mul (v, r, b_2);
992 gcry_mpi_sub (t_2, a_2, v);
995 gcry_mpi_set (a_1, b_1);
996 gcry_mpi_set (a_2, b_2);
998 gcry_mpi_set (b_1, t_1);
999 gcry_mpi_set (b_2, t_2);
1001 gcry_mpi_set (big_a, big_b);
1002 gcry_mpi_set (big_b, big_t);
1006 gcry_mpi_t paillier_n;
1008 GNUNET_CRYPTO_mpi_scan_unsigned (&paillier_n, ppub, sizeof (struct GNUNET_CRYPTO_PaillierPublicKey));
1010 gcry_mpi_set (xres, b_2);
1011 gcry_mpi_invm (xres, xres, elgamal_q);
1012 gcry_mpi_mulm (xres, xres, b_1, elgamal_q);
1015 gcry_mpi_release (a_1);
1016 gcry_mpi_release (a_2);
1017 gcry_mpi_release (b_1);
1018 gcry_mpi_release (b_2);
1019 gcry_mpi_release (big_a);
1020 gcry_mpi_release (big_b);
1021 gcry_mpi_release (big_t);
1022 gcry_mpi_release (n);
1023 gcry_mpi_release (t_1);
1024 gcry_mpi_release (t_2);
1025 gcry_mpi_release (t);
1026 gcry_mpi_release (r);
1027 gcry_mpi_release (v);
1032 get_fair_encryption_challenge (const struct GNUNET_SECRETSHARING_FairEncryption *fe, gcry_mpi_t e)
1035 struct GNUNET_CRYPTO_PaillierCiphertext c;
1036 char h[GNUNET_SECRETSHARING_ELGAMAL_BITS / 8];
1037 char t1[GNUNET_SECRETSHARING_ELGAMAL_BITS / 8];
1038 char t2[GNUNET_CRYPTO_PAILLIER_BITS * 2 / 8];
1040 struct GNUNET_HashCode e_hash;
1042 GNUNET_memcpy (&hash_data.c, &fe->c, sizeof (struct GNUNET_CRYPTO_PaillierCiphertext));
1043 GNUNET_memcpy (&hash_data.h, &fe->h, GNUNET_SECRETSHARING_ELGAMAL_BITS / 8);
1044 GNUNET_memcpy (&hash_data.t1, &fe->t1, GNUNET_SECRETSHARING_ELGAMAL_BITS / 8);
1045 GNUNET_memcpy (&hash_data.t2, &fe->t2, GNUNET_CRYPTO_PAILLIER_BITS * 2 / 8);
1047 GNUNET_CRYPTO_mpi_scan_unsigned (&e, &e_hash, sizeof (struct GNUNET_HashCode));
1048 gcry_mpi_mod (e, e, elgamal_q);
1053 verify_fair (const struct GNUNET_CRYPTO_PaillierPublicKey *ppub, const struct GNUNET_SECRETSHARING_FairEncryption *fe)
1068 GNUNET_assert (NULL != (n_sq = gcry_mpi_new (0)));
1069 GNUNET_assert (NULL != (tmp1 = gcry_mpi_new (0)));
1070 GNUNET_assert (NULL != (tmp2 = gcry_mpi_new (0)));
1071 GNUNET_assert (NULL != (e = gcry_mpi_new (0)));
1073 get_fair_encryption_challenge (fe, e);
1075 GNUNET_CRYPTO_mpi_scan_unsigned (&n, ppub, sizeof (struct GNUNET_CRYPTO_PaillierPublicKey));
1076 GNUNET_CRYPTO_mpi_scan_unsigned (&t1, fe->t1, GNUNET_CRYPTO_PAILLIER_BITS / 8);
1077 GNUNET_CRYPTO_mpi_scan_unsigned (&z, fe->z, GNUNET_SECRETSHARING_ELGAMAL_BITS / 8);
1078 GNUNET_CRYPTO_mpi_scan_unsigned (&y, fe->h, GNUNET_SECRETSHARING_ELGAMAL_BITS / 8);
1079 GNUNET_CRYPTO_mpi_scan_unsigned (&w, fe->w, GNUNET_CRYPTO_PAILLIER_BITS / 8);
1080 GNUNET_CRYPTO_mpi_scan_unsigned (&big_y, fe->c.bits, GNUNET_CRYPTO_PAILLIER_BITS * 2 / 8);
1081 GNUNET_CRYPTO_mpi_scan_unsigned (&t2, fe->t2, GNUNET_CRYPTO_PAILLIER_BITS * 2 / 8);
1082 gcry_mpi_mul (n_sq, n, n);
1085 gcry_mpi_powm (tmp1, elgamal_g, z, elgamal_p);
1087 gcry_mpi_powm (tmp1, y, e, elgamal_p);
1088 gcry_mpi_invm (tmp1, tmp1, elgamal_p);
1089 // tmp1 = tmp1 * tmp2
1090 gcry_mpi_mulm (tmp1, tmp1, tmp2, elgamal_p);
1092 if (0 == gcry_mpi_cmp (t1, tmp1))
1094 GNUNET_log (GNUNET_ERROR_TYPE_ERROR, "fair encryption invalid (t1)\n");
1099 gcry_mpi_powm (big_y, big_y, e, n_sq);
1100 gcry_mpi_invm (big_y, big_y, n_sq);
1102 gcry_mpi_add_ui (tmp1, n, 1);
1103 gcry_mpi_powm (tmp1, tmp1, z, n_sq);
1105 gcry_mpi_powm (tmp2, w, n, n_sq);
1107 gcry_mpi_mulm (tmp1, tmp1, tmp2, n_sq);
1108 gcry_mpi_mulm (tmp1, tmp1, big_y, n_sq);
1111 if (0 == gcry_mpi_cmp (t2, tmp1))
1113 GNUNET_log (GNUNET_ERROR_TYPE_ERROR, "fair encryption invalid (t2)\n");
1122 gcry_mpi_release (n);
1123 gcry_mpi_release (n_sq);
1124 gcry_mpi_release (z);
1125 gcry_mpi_release (t1);
1126 gcry_mpi_release (t2);
1127 gcry_mpi_release (e);
1128 gcry_mpi_release (w);
1129 gcry_mpi_release (tmp1);
1130 gcry_mpi_release (tmp2);
1131 gcry_mpi_release (y);
1132 gcry_mpi_release (big_y);
1138 * Create a fair Paillier encryption of then given ciphertext.
1140 * @param v the ciphertext
1141 * @param[out] fe the fair encryption
1144 encrypt_fair (gcry_mpi_t v, const struct GNUNET_CRYPTO_PaillierPublicKey *ppub, struct GNUNET_SECRETSHARING_FairEncryption *fe)
1159 GNUNET_assert (NULL != (r = gcry_mpi_new (0)));
1160 GNUNET_assert (NULL != (s = gcry_mpi_new (0)));
1161 GNUNET_assert (NULL != (t1 = gcry_mpi_new (0)));
1162 GNUNET_assert (NULL != (t2 = gcry_mpi_new (0)));
1163 GNUNET_assert (NULL != (z = gcry_mpi_new (0)));
1164 GNUNET_assert (NULL != (w = gcry_mpi_new (0)));
1165 GNUNET_assert (NULL != (n_sq = gcry_mpi_new (0)));
1166 GNUNET_assert (NULL != (e = gcry_mpi_new (0)));
1167 GNUNET_assert (NULL != (u = gcry_mpi_new (0)));
1168 GNUNET_assert (NULL != (Y = gcry_mpi_new (0)));
1169 GNUNET_assert (NULL != (G = gcry_mpi_new (0)));
1170 GNUNET_assert (NULL != (h = gcry_mpi_new (0)));
1172 GNUNET_CRYPTO_mpi_scan_unsigned (&n, ppub, sizeof (struct GNUNET_CRYPTO_PaillierPublicKey));
1173 gcry_mpi_mul (n_sq, n, n);
1174 gcry_mpi_add_ui (G, n, 1);
1177 gcry_mpi_randomize (u, GNUNET_CRYPTO_PAILLIER_BITS, GCRY_WEAK_RANDOM);
1179 while (gcry_mpi_cmp (u, n) >= 0);
1181 gcry_mpi_powm (t1, G, v, n_sq);
1182 gcry_mpi_powm (t2, u, n, n_sq);
1183 gcry_mpi_mulm (Y, t1, t2, n_sq);
1185 GNUNET_CRYPTO_mpi_print_unsigned (fe->c.bits,
1190 gcry_mpi_randomize (r, 2048, GCRY_WEAK_RANDOM);
1192 gcry_mpi_randomize (s, GNUNET_CRYPTO_PAILLIER_BITS, GCRY_WEAK_RANDOM);
1194 while (gcry_mpi_cmp (s, n) >= 0);
1197 gcry_mpi_mulm (t1, elgamal_g, r, elgamal_p);
1198 // compute t2 (use z and w as temp)
1199 gcry_mpi_powm (z, G, r, n_sq);
1200 gcry_mpi_powm (w, s, n, n_sq);
1201 gcry_mpi_mulm (t2, z, w, n_sq);
1204 gcry_mpi_powm (h, elgamal_g, v, elgamal_p);
1206 GNUNET_CRYPTO_mpi_print_unsigned (fe->h,
1207 GNUNET_SECRETSHARING_ELGAMAL_BITS / 8,
1210 GNUNET_CRYPTO_mpi_print_unsigned (fe->t1,
1211 GNUNET_SECRETSHARING_ELGAMAL_BITS / 8,
1214 GNUNET_CRYPTO_mpi_print_unsigned (fe->t2,
1215 GNUNET_CRYPTO_PAILLIER_BITS * 2 / 8,
1219 get_fair_encryption_challenge (fe, e);
1222 gcry_mpi_mul (z, e, v);
1223 gcry_mpi_addm (z, z, r, elgamal_q);
1225 gcry_mpi_powm (w, u, e, n);
1226 gcry_mpi_mulm (w, w, s, n);
1228 GNUNET_CRYPTO_mpi_print_unsigned (fe->z,
1229 GNUNET_SECRETSHARING_ELGAMAL_BITS / 8,
1232 GNUNET_CRYPTO_mpi_print_unsigned (fe->w,
1233 GNUNET_CRYPTO_PAILLIER_BITS / 8,
1236 gcry_mpi_release (n);
1237 gcry_mpi_release (r);
1238 gcry_mpi_release (s);
1239 gcry_mpi_release (t1);
1240 gcry_mpi_release (t2);
1241 gcry_mpi_release (z);
1242 gcry_mpi_release (w);
1243 gcry_mpi_release (e);
1244 gcry_mpi_release (n_sq);
1245 gcry_mpi_release (u);
1246 gcry_mpi_release (Y);
1247 gcry_mpi_release (G);
1248 gcry_mpi_release (h);
1253 * Insert round 2 element in the consensus, consisting of
1254 * (1) The exponentiated pre-share polynomial coefficients A_{i,l}=g^{a_{i,l}}
1255 * (2) The exponentiated pre-shares y_{i,j}=g^{s_{i,j}}
1256 * (3) The encrypted pre-shares Y_{i,j}
1257 * (4) The zero knowledge proof for fairness of
1260 * @param ks session to use
1263 insert_round2_element (struct KeygenSession *ks)
1265 struct GNUNET_SET_Element *element;
1266 struct GNUNET_SECRETSHARING_KeygenRevealData *d;
1268 unsigned char *last_pos;
1269 size_t element_size;
1274 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "P%u: Inserting round2 element\n",
1275 ks->local_peer_idx);
1277 GNUNET_assert (NULL != (v = gcry_mpi_new (GNUNET_SECRETSHARING_ELGAMAL_BITS)));
1278 GNUNET_assert (NULL != (idx = gcry_mpi_new (GNUNET_SECRETSHARING_ELGAMAL_BITS)));
1280 element_size = (sizeof (struct GNUNET_SECRETSHARING_KeygenRevealData) +
1281 sizeof (struct GNUNET_SECRETSHARING_FairEncryption) * ks->num_peers +
1282 GNUNET_SECRETSHARING_ELGAMAL_BITS / 8 * ks->threshold);
1284 element = GNUNET_malloc (sizeof (struct GNUNET_SET_Element) + element_size);
1285 element->size = element_size;
1286 element->data = (void *) &element[1];
1288 d = (void *) element->data;
1291 // start inserting vector elements
1292 // after the fixed part of the element's data
1293 pos = (void *) &d[1];
1294 last_pos = pos + element_size;
1296 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "P%u: computed exp preshares\n",
1297 ks->local_peer_idx);
1299 // encrypted pre-shares
1300 // and fair encryption proof
1302 for (i = 0; i < ks->num_peers; i++)
1304 ptrdiff_t remaining = last_pos - pos;
1305 struct GNUNET_SECRETSHARING_FairEncryption *fe = (void *) pos;
1307 GNUNET_assert (remaining > 0);
1308 memset (fe, 0, sizeof *fe);
1309 if (GNUNET_YES == ks->info[i].round1_valid)
1311 gcry_mpi_set_ui (idx, i + 1);
1312 // evaluate the polynomial
1313 horner_eval (v, ks->presecret_polynomial, ks->threshold, idx, elgamal_q);
1314 // encrypt the result
1315 encrypt_fair (v, &ks->info[i].paillier_public_key, fe);
1321 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "P%u: computed enc preshares\n",
1322 ks->local_peer_idx);
1324 // exponentiated coefficients
1325 for (i = 0; i < ks->threshold; i++)
1327 ptrdiff_t remaining = last_pos - pos;
1328 GNUNET_assert (remaining > 0);
1329 gcry_mpi_powm (v, elgamal_g, ks->presecret_polynomial[i], elgamal_p);
1330 GNUNET_CRYPTO_mpi_print_unsigned (pos, GNUNET_SECRETSHARING_ELGAMAL_BITS / 8, v);
1331 pos += GNUNET_SECRETSHARING_ELGAMAL_BITS / 8;
1334 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "P%u: computed exp coefficients\n",
1335 ks->local_peer_idx);
1338 d->purpose.size = htonl (element_size - offsetof (struct GNUNET_SECRETSHARING_KeygenRevealData, purpose));
1339 d->purpose.purpose = htonl (GNUNET_SIGNATURE_PURPOSE_SECRETSHARING_DKG2);
1340 GNUNET_assert (GNUNET_OK ==
1341 GNUNET_CRYPTO_eddsa_sign (my_peer_private_key,
1345 GNUNET_CONSENSUS_insert (ks->consensus, element, NULL, NULL);
1346 GNUNET_free (element); /* FIXME: maybe stack-allocate instead? */
1348 gcry_mpi_release (v);
1349 gcry_mpi_release (idx);
1354 keygen_reveal_get_exp_coeff (struct KeygenSession *ks,
1355 const struct GNUNET_SECRETSHARING_KeygenRevealData *d,
1359 gcry_mpi_t exp_coeff;
1361 GNUNET_assert (idx < ks->threshold);
1363 pos = (void *) &d[1];
1364 // skip encrypted pre-shares
1365 pos += sizeof (struct GNUNET_SECRETSHARING_FairEncryption) * ks->num_peers;
1366 // skip exp. coeffs we are not interested in
1367 pos += GNUNET_SECRETSHARING_ELGAMAL_BITS / 8 * idx;
1368 // the first exponentiated coefficient is the public key share
1369 GNUNET_CRYPTO_mpi_scan_unsigned (&exp_coeff, pos, GNUNET_SECRETSHARING_ELGAMAL_BITS / 8);
1374 static struct GNUNET_SECRETSHARING_FairEncryption *
1375 keygen_reveal_get_enc_preshare (struct KeygenSession *ks,
1376 const struct GNUNET_SECRETSHARING_KeygenRevealData *d,
1381 GNUNET_assert (idx < ks->num_peers);
1383 pos = (void *) &d[1];
1384 // skip encrypted pre-shares we're not interested in
1385 pos += sizeof (struct GNUNET_SECRETSHARING_FairEncryption) * idx;
1386 return (struct GNUNET_SECRETSHARING_FairEncryption *) pos;
1391 keygen_reveal_get_exp_preshare (struct KeygenSession *ks,
1392 const struct GNUNET_SECRETSHARING_KeygenRevealData *d,
1395 gcry_mpi_t exp_preshare;
1396 struct GNUNET_SECRETSHARING_FairEncryption *fe;
1398 GNUNET_assert (idx < ks->num_peers);
1399 fe = keygen_reveal_get_enc_preshare (ks, d, idx);
1400 GNUNET_CRYPTO_mpi_scan_unsigned (&exp_preshare, fe->h, GNUNET_SECRETSHARING_ELGAMAL_BITS / 8);
1401 return exp_preshare;
1406 keygen_round2_new_element (void *cls,
1407 const struct GNUNET_SET_Element *element)
1409 struct KeygenSession *ks = cls;
1410 const struct GNUNET_SECRETSHARING_KeygenRevealData *d;
1411 struct KeygenPeerInfo *info;
1412 size_t expected_element_size;
1416 gcry_mpi_t public_key_share;
1417 gcry_mpi_t preshare;
1419 if (NULL == element)
1421 GNUNET_log (GNUNET_ERROR_TYPE_WARNING, "round2 consensus failed\n");
1425 expected_element_size = (sizeof (struct GNUNET_SECRETSHARING_KeygenRevealData) +
1426 sizeof (struct GNUNET_SECRETSHARING_FairEncryption) * ks->num_peers +
1427 GNUNET_SECRETSHARING_ELGAMAL_BITS / 8 * ks->threshold);
1429 if (element->size != expected_element_size)
1431 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
1432 "keygen round2 data with wrong size (%u) in consensus, "
1434 element->size, expected_element_size);
1438 d = (const void *) element->data;
1440 info = get_keygen_peer_info (ks, &d->peer);
1444 GNUNET_log (GNUNET_ERROR_TYPE_WARNING, "keygen commit data with wrong peer identity (%s) in consensus\n",
1445 GNUNET_i2s (&d->peer));
1449 if (GNUNET_NO == info->round1_valid)
1451 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
1452 "ignoring round2 element from peer with invalid round1 element (%s)\n",
1453 GNUNET_i2s (&d->peer));
1457 if (GNUNET_YES == info->round2_valid)
1459 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
1460 "ignoring duplicate round2 element (%s)\n",
1461 GNUNET_i2s (&d->peer));
1465 GNUNET_log (GNUNET_ERROR_TYPE_INFO, "got round2 element\n");
1467 if (ntohl (d->purpose.size) !=
1468 element->size - offsetof (struct GNUNET_SECRETSHARING_KeygenRevealData, purpose))
1470 GNUNET_log (GNUNET_ERROR_TYPE_WARNING, "keygen reveal data with wrong signature purpose size in consensus\n");
1474 if (GNUNET_OK != GNUNET_CRYPTO_eddsa_verify (GNUNET_SIGNATURE_PURPOSE_SECRETSHARING_DKG2,
1475 &d->purpose, &d->signature, &d->peer.public_key))
1477 GNUNET_log (GNUNET_ERROR_TYPE_WARNING, "keygen reveal data with invalid signature in consensus\n");
1481 public_key_share = keygen_reveal_get_exp_coeff (ks, d, 0);
1482 info->preshare_commitment = keygen_reveal_get_exp_preshare (ks, d, ks->local_peer_idx);
1484 if (NULL == ks->public_key)
1486 GNUNET_assert (NULL != (ks->public_key = gcry_mpi_new (0)));
1487 gcry_mpi_set_ui (ks->public_key, 1);
1489 gcry_mpi_mulm (ks->public_key, ks->public_key, public_key_share, elgamal_p);
1491 gcry_mpi_release (public_key_share);
1492 public_key_share = NULL;
1495 struct GNUNET_SECRETSHARING_FairEncryption *fe = keygen_reveal_get_enc_preshare (ks, d, ks->local_peer_idx);
1496 GNUNET_assert (NULL != (preshare = gcry_mpi_new (0)));
1497 GNUNET_CRYPTO_paillier_decrypt (&ks->paillier_private_key,
1498 &ks->info[ks->local_peer_idx].paillier_public_key,
1502 // FIXME: not doing the restoration is less expensive
1503 restore_fair (&ks->info[ks->local_peer_idx].paillier_public_key,
1509 GNUNET_assert (NULL != (tmp = gcry_mpi_new (0)));
1510 gcry_mpi_powm (tmp, elgamal_g, preshare, elgamal_p);
1512 cmp_result = gcry_mpi_cmp (tmp, info->preshare_commitment);
1513 gcry_mpi_release (tmp);
1515 if (0 != cmp_result)
1517 GNUNET_log (GNUNET_ERROR_TYPE_WARNING, "P%u: Got invalid presecret from P%u\n",
1518 (unsigned int) ks->local_peer_idx, (unsigned int) (info - ks->info));
1522 if (NULL == ks->my_share)
1524 GNUNET_assert (NULL != (ks->my_share = gcry_mpi_new (0)));
1526 gcry_mpi_addm (ks->my_share, ks->my_share, preshare, elgamal_q);
1528 for (j = 0; j < ks->num_peers; j++)
1530 gcry_mpi_t presigma;
1531 if (NULL == ks->info[j].sigma)
1533 GNUNET_assert (NULL != (ks->info[j].sigma = gcry_mpi_new (0)));
1534 gcry_mpi_set_ui (ks->info[j].sigma, 1);
1536 presigma = keygen_reveal_get_exp_preshare (ks, d, j);
1537 gcry_mpi_mulm (ks->info[j].sigma, ks->info[j].sigma, presigma, elgamal_p);
1538 gcry_mpi_release (presigma);
1542 GNUNET_assert (NULL != (prod = gcry_mpi_new (0)));
1544 GNUNET_assert (NULL != (j_to_k = gcry_mpi_new (0)));
1545 // validate that the polynomial sharing matches the additive sharing
1546 for (j = 0; j < ks->num_peers; j++)
1550 gcry_mpi_t exp_preshare;
1551 gcry_mpi_set_ui (prod, 1);
1552 for (k = 0; k < ks->threshold; k++)
1554 // Using pow(double,double) is a bit sketchy.
1555 // We count players from 1, but shares from 0.
1557 gcry_mpi_set_ui (j_to_k, (unsigned int) pow(j+1, k));
1558 tmp = keygen_reveal_get_exp_coeff (ks, d, k);
1559 gcry_mpi_powm (tmp, tmp, j_to_k, elgamal_p);
1560 gcry_mpi_mulm (prod, prod, tmp, elgamal_p);
1561 gcry_mpi_release (tmp);
1563 exp_preshare = keygen_reveal_get_exp_preshare (ks, d, j);
1564 gcry_mpi_mod (exp_preshare, exp_preshare, elgamal_p);
1565 cmp_result = gcry_mpi_cmp (prod, exp_preshare);
1566 gcry_mpi_release (exp_preshare);
1567 exp_preshare = NULL;
1568 if (0 != cmp_result)
1570 GNUNET_log (GNUNET_ERROR_TYPE_WARNING, "P%u: reveal data from P%u incorrect\n",
1571 ks->local_peer_idx, j);
1572 /* no need for further verification, round2 stays invalid ... */
1577 // TODO: verify proof of fair encryption (once implemented)
1578 for (j = 0; j < ks->num_peers; j++)
1580 struct GNUNET_SECRETSHARING_FairEncryption *fe = keygen_reveal_get_enc_preshare (ks, d, j);
1581 if (GNUNET_YES != verify_fair (&ks->info[j].paillier_public_key, fe))
1583 GNUNET_log (GNUNET_ERROR_TYPE_WARNING, "P%u: reveal data from P%u incorrect (fair encryption)\n",
1584 ks->local_peer_idx, j);
1590 info->round2_valid = GNUNET_YES;
1592 gcry_mpi_release (preshare);
1593 gcry_mpi_release (prod);
1594 gcry_mpi_release (j_to_k);
1599 * Called when the first consensus round has concluded.
1600 * Will initiate the second round.
1602 * @param cls closure
1605 keygen_round1_conclude (void *cls)
1607 struct KeygenSession *ks = cls;
1609 GNUNET_CONSENSUS_destroy (ks->consensus);
1611 ks->consensus = GNUNET_CONSENSUS_create (cfg, ks->num_peers, ks->peers, &ks->session_id,
1612 time_between (ks->start_time, ks->deadline, 1, 2),
1614 keygen_round2_new_element, ks);
1616 insert_round2_element (ks);
1618 GNUNET_CONSENSUS_conclude (ks->consensus,
1619 keygen_round2_conclude,
1625 * Insert the ephemeral key and the presecret commitment
1626 * of this peer in the consensus of the given session.
1628 * @param ks session to use
1631 insert_round1_element (struct KeygenSession *ks)
1633 struct GNUNET_SET_Element *element;
1634 struct GNUNET_SECRETSHARING_KeygenCommitData *d;
1637 // big-endian representation of 'v'
1638 unsigned char v_data[GNUNET_SECRETSHARING_ELGAMAL_BITS / 8];
1640 element = GNUNET_malloc (sizeof *element + sizeof *d);
1641 d = (void *) &element[1];
1643 element->size = sizeof *d;
1647 GNUNET_assert (0 != (v = gcry_mpi_new (GNUNET_SECRETSHARING_ELGAMAL_BITS)));
1649 gcry_mpi_powm (v, elgamal_g, ks->presecret_polynomial[0], elgamal_p);
1651 GNUNET_CRYPTO_mpi_print_unsigned (v_data, GNUNET_SECRETSHARING_ELGAMAL_BITS / 8, v);
1653 GNUNET_CRYPTO_hash (v_data, GNUNET_SECRETSHARING_ELGAMAL_BITS / 8, &d->commitment);
1655 d->pubkey = ks->info[ks->local_peer_idx].paillier_public_key;
1657 d->purpose.size = htonl ((sizeof *d) - offsetof (struct GNUNET_SECRETSHARING_KeygenCommitData, purpose));
1658 d->purpose.purpose = htonl (GNUNET_SIGNATURE_PURPOSE_SECRETSHARING_DKG1);
1659 GNUNET_assert (GNUNET_OK ==
1660 GNUNET_CRYPTO_eddsa_sign (my_peer_private_key,
1664 GNUNET_CONSENSUS_insert (ks->consensus, element, NULL, NULL);
1666 gcry_mpi_release (v);
1667 GNUNET_free (element);
1672 * Functions with this signature are called whenever a message is
1675 * @param cls closure
1676 * @param client identification of the client
1677 * @param message the actual message
1679 static void handle_client_keygen (void *cls,
1680 struct GNUNET_SERVER_Client *client,
1681 const struct GNUNET_MessageHeader
1684 const struct GNUNET_SECRETSHARING_CreateMessage *msg =
1685 (const struct GNUNET_SECRETSHARING_CreateMessage *) message;
1686 struct KeygenSession *ks;
1689 GNUNET_log (GNUNET_ERROR_TYPE_INFO, "client requested key generation\n");
1691 ks = GNUNET_new (struct KeygenSession);
1693 /* FIXME: check if client already has some session */
1695 GNUNET_CONTAINER_DLL_insert (keygen_sessions_head, keygen_sessions_tail, ks);
1697 ks->client = client;
1698 ks->client_mq = GNUNET_MQ_queue_for_server_client (client);
1700 ks->deadline = GNUNET_TIME_absolute_ntoh (msg->deadline);
1701 ks->threshold = ntohs (msg->threshold);
1702 ks->num_peers = ntohs (msg->num_peers);
1704 ks->peers = normalize_peers ((struct GNUNET_PeerIdentity *) &msg[1], ks->num_peers,
1705 &ks->num_peers, &ks->local_peer_idx);
1708 GNUNET_log (GNUNET_ERROR_TYPE_INFO, "first round of consensus with %u peers\n", ks->num_peers);
1709 ks->consensus = GNUNET_CONSENSUS_create (cfg, ks->num_peers, ks->peers, &msg->session_id,
1710 GNUNET_TIME_absolute_ntoh (msg->start),
1711 GNUNET_TIME_absolute_ntoh (msg->deadline),
1712 keygen_round1_new_element, ks);
1714 ks->info = GNUNET_new_array (ks->num_peers, struct KeygenPeerInfo);
1716 for (i = 0; i < ks->num_peers; i++)
1717 ks->info[i].peer = ks->peers[i];
1719 GNUNET_CRYPTO_paillier_create (&ks->info[ks->local_peer_idx].paillier_public_key,
1720 &ks->paillier_private_key);
1722 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "P%u: Generated paillier key pair\n", ks->local_peer_idx);
1724 generate_presecret_polynomial (ks);
1726 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "P%u: Generated presecret polynomial\n", ks->local_peer_idx);
1728 insert_round1_element (ks);
1730 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "P%u: Concluding for round 1\n", ks->local_peer_idx);
1732 GNUNET_CONSENSUS_conclude (ks->consensus,
1733 keygen_round1_conclude,
1736 GNUNET_SERVER_receive_done (client, GNUNET_OK);
1738 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "P%u: Waiting for round 1 elements ...\n", ks->local_peer_idx);
1743 * Called when the partial decryption consensus concludes.
1746 decrypt_conclude (void *cls)
1748 struct DecryptSession *ds = cls;
1749 struct GNUNET_SECRETSHARING_DecryptResponseMessage *msg;
1750 struct GNUNET_MQ_Envelope *ev;
1751 gcry_mpi_t lagrange;
1756 unsigned int *indices;
1761 GNUNET_CONSENSUS_destroy (ds->consensus);
1762 ds->consensus = NULL;
1764 GNUNET_assert (0 != (lagrange = gcry_mpi_new (0)));
1765 GNUNET_assert (0 != (m = gcry_mpi_new (0)));
1766 GNUNET_assert (0 != (tmp = gcry_mpi_new (0)));
1767 GNUNET_assert (0 != (prod = gcry_mpi_new (0)));
1770 for (i = 0; i < ds->share->num_peers; i++)
1771 if (NULL != ds->info[i].partial_decryption)
1774 indices = GNUNET_malloc (num * sizeof (unsigned int));
1776 for (i = 0; i < ds->share->num_peers; i++)
1777 if (NULL != ds->info[i].partial_decryption)
1778 indices[j++] = ds->info[i].original_index;
1780 GNUNET_log (GNUNET_ERROR_TYPE_INFO, "P%u: decrypt conclude, with %u peers\n",
1781 ds->share->my_peer, num);
1783 gcry_mpi_set_ui (prod, 1);
1784 for (i = 0; i < num; i++)
1787 GNUNET_log (GNUNET_ERROR_TYPE_INFO, "P%u: index of %u: %u\n",
1788 ds->share->my_peer, i, indices[i]);
1789 compute_lagrange_coefficient (lagrange, indices[i], indices, num);
1791 gcry_mpi_powm (tmp, ds->info[indices[i]].partial_decryption, lagrange, elgamal_p);
1793 // product of all exponentiated partiel decryptions ...
1794 gcry_mpi_mulm (prod, prod, tmp, elgamal_p);
1797 GNUNET_CRYPTO_mpi_scan_unsigned (&c_2, ds->ciphertext.c2_bits, GNUNET_SECRETSHARING_ELGAMAL_BITS / 8);
1799 GNUNET_assert (0 != gcry_mpi_invm (prod, prod, elgamal_p));
1800 gcry_mpi_mulm (m, c_2, prod, elgamal_p);
1801 ev = GNUNET_MQ_msg (msg, GNUNET_MESSAGE_TYPE_SECRETSHARING_CLIENT_DECRYPT_DONE);
1802 GNUNET_CRYPTO_mpi_print_unsigned (&msg->plaintext, GNUNET_SECRETSHARING_ELGAMAL_BITS / 8, m);
1803 msg->success = htonl (1);
1804 GNUNET_MQ_send (ds->client_mq, ev);
1806 GNUNET_log (GNUNET_ERROR_TYPE_INFO, "sent decrypt done to client\n");
1808 GNUNET_free (indices);
1810 gcry_mpi_release(lagrange);
1811 gcry_mpi_release(m);
1812 gcry_mpi_release(tmp);
1813 gcry_mpi_release(prod);
1814 gcry_mpi_release(c_2);
1816 // FIXME: what if not enough peers participated?
1821 * Get a string representation of an MPI.
1822 * The caller must free the returned string.
1824 * @param mpi mpi to convert to a string
1825 * @return string representation of @a mpi, must be free'd by the caller
1828 mpi_to_str (gcry_mpi_t mpi)
1832 GNUNET_assert (0 == gcry_mpi_aprint (GCRYMPI_FMT_HEX, &buf, NULL, mpi));
1833 return (char *) buf;
1838 * Called when a new partial decryption arrives.
1841 decrypt_new_element (void *cls,
1842 const struct GNUNET_SET_Element *element)
1844 struct DecryptSession *session = cls;
1845 const struct GNUNET_SECRETSHARING_DecryptData *d;
1846 struct DecryptPeerInfo *info;
1847 struct GNUNET_HashCode challenge_hash;
1851 /* nizk challenge */
1852 gcry_mpi_t challenge;
1853 /* nizk commit1, g^\beta */
1855 /* nizk commit2, c_1^\beta */
1857 /* homomorphic commitment to the peer's share,
1858 * public key share */
1860 /* partial decryption we received */
1862 /* ciphertext component #1 */
1864 /* temporary variable (for comparision) #1 */
1866 /* temporary variable (for comparision) #2 */
1869 if (NULL == element)
1871 GNUNET_log (GNUNET_ERROR_TYPE_ERROR, "decryption failed\n");
1872 /* FIXME: destroy */
1876 if (element->size != sizeof *d)
1878 GNUNET_log (GNUNET_ERROR_TYPE_ERROR, "element of wrong size in decrypt consensus\n");
1884 info = get_decrypt_peer_info (session, &d->peer);
1888 GNUNET_log (GNUNET_ERROR_TYPE_ERROR, "decrypt element from invalid peer (%s)\n",
1889 GNUNET_i2s (&d->peer));
1893 if (NULL != info->partial_decryption)
1895 GNUNET_log (GNUNET_ERROR_TYPE_ERROR, "decrypt element duplicate\n");
1899 if (0 != memcmp (&d->ciphertext, &session->ciphertext, sizeof (struct GNUNET_SECRETSHARING_Ciphertext)))
1901 GNUNET_log (GNUNET_ERROR_TYPE_WARNING, "P%u: got decrypt element with non-matching ciphertext from P%u\n",
1902 (unsigned int) session->share->my_peer, (unsigned int) (info - session->info));
1908 GNUNET_CRYPTO_hash (offsetof (struct GNUNET_SECRETSHARING_DecryptData, ciphertext) + (char *) d,
1909 offsetof (struct GNUNET_SECRETSHARING_DecryptData, nizk_response) -
1910 offsetof (struct GNUNET_SECRETSHARING_DecryptData, ciphertext),
1913 GNUNET_CRYPTO_mpi_scan_unsigned (&challenge, &challenge_hash,
1914 sizeof (struct GNUNET_HashCode));
1916 GNUNET_CRYPTO_mpi_scan_unsigned (&sigma, &session->share->sigmas[info - session->info],
1917 sizeof (struct GNUNET_SECRETSHARING_FieldElement));
1919 GNUNET_CRYPTO_mpi_scan_unsigned (&c1, session->ciphertext.c1_bits,
1920 sizeof (struct GNUNET_SECRETSHARING_FieldElement));
1922 GNUNET_CRYPTO_mpi_scan_unsigned (&commit1, &d->nizk_commit1,
1923 sizeof (struct GNUNET_SECRETSHARING_FieldElement));
1925 GNUNET_CRYPTO_mpi_scan_unsigned (&commit2, &d->nizk_commit2,
1926 sizeof (struct GNUNET_SECRETSHARING_FieldElement));
1928 GNUNET_CRYPTO_mpi_scan_unsigned (&r, &d->nizk_response,
1929 sizeof (struct GNUNET_SECRETSHARING_FieldElement));
1931 GNUNET_CRYPTO_mpi_scan_unsigned (&w, &d->partial_decryption,
1932 sizeof (struct GNUNET_SECRETSHARING_FieldElement));
1934 GNUNET_assert (NULL != (tmp1 = gcry_mpi_new (0)));
1935 GNUNET_assert (NULL != (tmp2 = gcry_mpi_new (0)));
1938 gcry_mpi_powm (tmp1, elgamal_g, r, elgamal_p);
1940 // tmp2 = g^\beta * \sigma^challenge
1941 gcry_mpi_powm (tmp2, sigma, challenge, elgamal_p);
1942 gcry_mpi_mulm (tmp2, tmp2, commit1, elgamal_p);
1944 if (0 != gcry_mpi_cmp (tmp1, tmp2))
1948 tmp1_str = mpi_to_str (tmp1);
1949 tmp2_str = mpi_to_str (tmp2);
1950 GNUNET_log (GNUNET_ERROR_TYPE_WARNING, "P%u: Received invalid partial decryption from P%ld (eqn 1), expected %s got %s\n",
1951 session->share->my_peer, info - session->info, tmp1_str, tmp2_str);
1952 GNUNET_free (tmp1_str);
1953 GNUNET_free (tmp2_str);
1958 gcry_mpi_powm (tmp1, c1, r, elgamal_p);
1960 gcry_mpi_powm (tmp2, w, challenge, elgamal_p);
1961 gcry_mpi_mulm (tmp2, tmp2, commit2, elgamal_p);
1964 if (0 != gcry_mpi_cmp (tmp1, tmp2))
1966 GNUNET_log (GNUNET_ERROR_TYPE_WARNING, "P%u: Received invalid partial decryption from P%ld (eqn 2)\n",
1967 session->share->my_peer, info - session->info);
1972 GNUNET_CRYPTO_mpi_scan_unsigned (&info->partial_decryption, &d->partial_decryption,
1973 GNUNET_SECRETSHARING_ELGAMAL_BITS / 8);
1975 gcry_mpi_release (tmp1);
1976 gcry_mpi_release (tmp2);
1977 gcry_mpi_release (sigma);
1978 gcry_mpi_release (commit1);
1979 gcry_mpi_release (commit2);
1980 gcry_mpi_release (r);
1981 gcry_mpi_release (w);
1982 gcry_mpi_release (challenge);
1983 gcry_mpi_release (c1);
1988 insert_decrypt_element (struct DecryptSession *ds)
1990 struct GNUNET_SECRETSHARING_DecryptData d;
1991 struct GNUNET_SET_Element element;
1994 /* partial decryption with our share */
1996 /* first component of the elgamal ciphertext */
1998 /* nonce for dlog zkp */
2001 gcry_mpi_t challenge;
2003 struct GNUNET_HashCode challenge_hash;
2005 /* make vagrind happy until we implement the real deal ... */
2006 memset (&d, 0, sizeof d);
2008 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "P%u: Inserting decrypt element\n",
2009 ds->share->my_peer);
2011 GNUNET_assert (ds->share->my_peer < ds->share->num_peers);
2013 GNUNET_CRYPTO_mpi_scan_unsigned (&c1, &ds->ciphertext.c1_bits,
2014 GNUNET_SECRETSHARING_ELGAMAL_BITS / 8);
2015 GNUNET_CRYPTO_mpi_scan_unsigned (&s, &ds->share->my_share,
2016 GNUNET_SECRETSHARING_ELGAMAL_BITS / 8);
2017 GNUNET_CRYPTO_mpi_scan_unsigned (&sigma, &ds->share->sigmas[ds->share->my_peer],
2018 GNUNET_SECRETSHARING_ELGAMAL_BITS / 8);
2020 GNUNET_assert (NULL != (w = gcry_mpi_new (0)));
2021 GNUNET_assert (NULL != (beta = gcry_mpi_new (0)));
2022 GNUNET_assert (NULL != (tmp = gcry_mpi_new (0)));
2024 // FIXME: unnecessary, remove once crypto works
2025 gcry_mpi_powm (tmp, elgamal_g, s, elgamal_p);
2026 if (0 != gcry_mpi_cmp (tmp, sigma))
2028 char *sigma_str = mpi_to_str (sigma);
2029 char *tmp_str = mpi_to_str (tmp);
2030 char *s_str = mpi_to_str (s);
2031 GNUNET_log (GNUNET_ERROR_TYPE_ERROR, "Share of P%u is invalid, ref sigma %s, "
2032 "computed sigma %s, s %s\n",
2034 sigma_str, tmp_str, s_str);
2035 GNUNET_free (sigma_str);
2036 GNUNET_free (tmp_str);
2037 GNUNET_free (s_str);
2040 gcry_mpi_powm (w, c1, s, elgamal_p);
2042 element.data = (void *) &d;
2043 element.size = sizeof (struct GNUNET_SECRETSHARING_DecryptData);
2044 element.element_type = 0;
2046 d.ciphertext = ds->ciphertext;
2048 GNUNET_CRYPTO_mpi_print_unsigned (&d.partial_decryption, GNUNET_SECRETSHARING_ELGAMAL_BITS / 8, w);
2050 // create the zero knowledge proof
2051 // randomly choose beta such that 0 < beta < q
2054 gcry_mpi_randomize (beta, GNUNET_SECRETSHARING_ELGAMAL_BITS - 1, GCRY_WEAK_RANDOM);
2055 } while ((gcry_mpi_cmp_ui (beta, 0) == 0) || (gcry_mpi_cmp (beta, elgamal_q) >= 0));
2057 gcry_mpi_powm (tmp, elgamal_g, beta, elgamal_p);
2058 GNUNET_CRYPTO_mpi_print_unsigned (&d.nizk_commit1, GNUNET_SECRETSHARING_ELGAMAL_BITS / 8, tmp);
2060 gcry_mpi_powm (tmp, c1, beta, elgamal_p);
2061 GNUNET_CRYPTO_mpi_print_unsigned (&d.nizk_commit2, GNUNET_SECRETSHARING_ELGAMAL_BITS / 8, tmp);
2063 // the challenge is the hash of everything up to the response
2064 GNUNET_CRYPTO_hash (offsetof (struct GNUNET_SECRETSHARING_DecryptData, ciphertext) + (char *) &d,
2065 offsetof (struct GNUNET_SECRETSHARING_DecryptData, nizk_response) -
2066 offsetof (struct GNUNET_SECRETSHARING_DecryptData, ciphertext),
2069 GNUNET_CRYPTO_mpi_scan_unsigned (&challenge, &challenge_hash,
2070 sizeof (struct GNUNET_HashCode));
2072 // compute the response in tmp,
2073 // tmp = (c * s + beta) mod q
2074 gcry_mpi_mulm (tmp, challenge, s, elgamal_q);
2075 gcry_mpi_addm (tmp, tmp, beta, elgamal_q);
2077 GNUNET_CRYPTO_mpi_print_unsigned (&d.nizk_response, GNUNET_SECRETSHARING_ELGAMAL_BITS / 8, tmp);
2079 d.purpose.size = htonl (element.size - offsetof (struct GNUNET_SECRETSHARING_DecryptData, purpose));
2080 d.purpose.purpose = htonl (GNUNET_SIGNATURE_PURPOSE_SECRETSHARING_DECRYPTION);
2082 GNUNET_assert (GNUNET_OK ==
2083 GNUNET_CRYPTO_eddsa_sign (my_peer_private_key,
2087 GNUNET_CONSENSUS_insert (ds->consensus, &element, NULL, NULL);
2088 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2089 "P%u: Inserting decrypt element done!\n",
2090 ds->share->my_peer);
2092 gcry_mpi_release (s);
2093 gcry_mpi_release (w);
2094 gcry_mpi_release (c1);
2095 gcry_mpi_release (beta);
2096 gcry_mpi_release (tmp);
2097 gcry_mpi_release (challenge);
2098 gcry_mpi_release (sigma);
2103 * Functions with this signature are called whenever a message is
2106 * @param cls closure
2107 * @param client identification of the client
2108 * @param message the actual message
2110 static void handle_client_decrypt (void *cls,
2111 struct GNUNET_SERVER_Client *client,
2112 const struct GNUNET_MessageHeader
2115 const struct GNUNET_SECRETSHARING_DecryptRequestMessage *msg =
2116 (const void *) message;
2117 struct DecryptSession *ds;
2118 struct GNUNET_HashCode session_id;
2121 ds = GNUNET_new (struct DecryptSession);
2122 // FIXME: check if session already exists
2123 GNUNET_CONTAINER_DLL_insert (decrypt_sessions_head, decrypt_sessions_tail, ds);
2124 ds->client = client;
2125 ds->client_mq = GNUNET_MQ_queue_for_server_client (client);
2126 ds->start = GNUNET_TIME_absolute_ntoh (msg->start);
2127 ds->deadline = GNUNET_TIME_absolute_ntoh (msg->deadline);
2128 ds->ciphertext = msg->ciphertext;
2130 ds->share = GNUNET_SECRETSHARING_share_read (&msg[1], ntohs (msg->header.size) - sizeof *msg, NULL);
2131 // FIXME: probably should be break rather than assert
2132 GNUNET_assert (NULL != ds->share);
2134 // FIXME: this is probably sufficient, but kdf/hash with all values would be nicer ...
2135 GNUNET_CRYPTO_hash (&msg->ciphertext, sizeof (struct GNUNET_SECRETSHARING_Ciphertext), &session_id);
2137 ds->consensus = GNUNET_CONSENSUS_create (cfg,
2138 ds->share->num_peers,
2143 &decrypt_new_element,
2147 ds->info = GNUNET_new_array (ds->share->num_peers, struct DecryptPeerInfo);
2148 for (i = 0; i < ds->share->num_peers; i++)
2150 ds->info[i].peer = ds->share->peers[i];
2151 ds->info[i].original_index = ds->share->original_indices[i];
2154 insert_decrypt_element (ds);
2156 GNUNET_CONSENSUS_conclude (ds->consensus, decrypt_conclude, ds);
2158 GNUNET_SERVER_receive_done (client, GNUNET_OK);
2160 GNUNET_log (GNUNET_ERROR_TYPE_INFO, "decrypting with %u peers\n",
2161 ds->share->num_peers);
2166 init_crypto_constants (void)
2168 GNUNET_assert (0 == gcry_mpi_scan (&elgamal_q, GCRYMPI_FMT_HEX,
2169 GNUNET_SECRETSHARING_ELGAMAL_Q_HEX, 0, NULL));
2170 GNUNET_assert (0 == gcry_mpi_scan (&elgamal_p, GCRYMPI_FMT_HEX,
2171 GNUNET_SECRETSHARING_ELGAMAL_P_HEX, 0, NULL));
2172 GNUNET_assert (0 == gcry_mpi_scan (&elgamal_g, GCRYMPI_FMT_HEX,
2173 GNUNET_SECRETSHARING_ELGAMAL_G_HEX, 0, NULL));
2177 static struct KeygenSession *
2178 keygen_session_get (struct GNUNET_SERVER_Client *client)
2180 struct KeygenSession *ks;
2181 for (ks = keygen_sessions_head; NULL != ks; ks = ks->next)
2182 if (ks->client == client)
2187 static struct DecryptSession *
2188 decrypt_session_get (struct GNUNET_SERVER_Client *client)
2190 struct DecryptSession *ds;
2191 for (ds = decrypt_sessions_head; NULL != ds; ds = ds->next)
2192 if (ds->client == client)
2199 * Clean up after a client has disconnected
2201 * @param cls closure, unused
2202 * @param client the client to clean up after
2205 handle_client_disconnect (void *cls, struct GNUNET_SERVER_Client *client)
2207 struct KeygenSession *ks;
2208 struct DecryptSession *ds;
2210 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "handling client disconnect\n");
2212 ks = keygen_session_get (client);
2214 keygen_session_destroy (ks);
2216 ds = decrypt_session_get (client);
2218 decrypt_session_destroy (ds);
2223 * Process template requests.
2225 * @param cls closure
2226 * @param server the initialized server
2227 * @param c configuration to use
2230 run (void *cls, struct GNUNET_SERVER_Handle *server,
2231 const struct GNUNET_CONFIGURATION_Handle *c)
2233 static const struct GNUNET_SERVER_MessageHandler handlers[] = {
2234 {handle_client_keygen, NULL, GNUNET_MESSAGE_TYPE_SECRETSHARING_CLIENT_GENERATE, 0},
2235 {handle_client_decrypt, NULL, GNUNET_MESSAGE_TYPE_SECRETSHARING_CLIENT_DECRYPT, 0},
2240 my_peer_private_key = GNUNET_CRYPTO_eddsa_key_create_from_configuration (c);
2241 if (NULL == my_peer_private_key)
2243 GNUNET_log (GNUNET_ERROR_TYPE_ERROR, "could not access host private key\n");
2245 GNUNET_SCHEDULER_shutdown ();
2248 init_crypto_constants ();
2249 if (GNUNET_OK != GNUNET_CRYPTO_get_peer_identity (cfg, &my_peer))
2251 GNUNET_log (GNUNET_ERROR_TYPE_ERROR, "could not retrieve host identity\n");
2253 GNUNET_SCHEDULER_shutdown ();
2256 GNUNET_SERVER_add_handlers (server, handlers);
2257 GNUNET_SERVER_disconnect_notify (server, &handle_client_disconnect, NULL);
2258 GNUNET_SCHEDULER_add_shutdown (&cleanup_task,
2264 * The main function for the template service.
2266 * @param argc number of arguments from the command line
2267 * @param argv command line arguments
2268 * @return 0 ok, 1 on error
2271 main (int argc, char *const *argv)
2273 return (GNUNET_OK ==
2274 GNUNET_SERVICE_run (argc, argv, "secretsharing",
2275 GNUNET_SERVICE_OPTION_NONE, &run, NULL)) ? 0 : 1;