2 This file is part of GNUnet.
3 Copyright (C) 2014 GNUnet e.V.
5 GNUnet is free software: you can redistribute it and/or modify it
6 under the terms of the GNU General Public License as published
7 by the Free Software Foundation, either version 3 of the License,
8 or (at your 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 Affero General Public License for more details.
16 #include "secretsharing.h"
19 * Read a share from its binary representation.
21 * @param data Binary representation of the share.
22 * @param len Length of @a data.
23 * @param[out] readlen Number of bytes read,
25 * @return The share, or NULL on error.
27 struct GNUNET_SECRETSHARING_Share *
28 GNUNET_SECRETSHARING_share_read (const void *data,
32 struct GNUNET_SECRETSHARING_Share *share;
33 const struct GNUNET_SECRETSHARING_ShareHeaderNBO *sh = data;
36 uint16_t payload_size;
38 payload_size = ntohs (sh->num_peers) *
39 (sizeof (uint16_t) + sizeof (struct GNUNET_SECRETSHARING_FieldElement) +
40 sizeof (struct GNUNET_PeerIdentity));
43 *readlen = payload_size + sizeof *sh;
45 share = GNUNET_new (struct GNUNET_SECRETSHARING_Share);
47 share->threshold = ntohs (sh->threshold);
48 share->num_peers = ntohs (sh->num_peers);
49 share->my_peer = ntohs (sh->my_peer);
51 share->my_share = sh->my_share;
52 share->public_key = sh->public_key;
54 p = (const char *) &sh[1];
56 n = share->num_peers * sizeof (struct GNUNET_PeerIdentity);
57 share->peers = GNUNET_new_array (share->num_peers,
58 struct GNUNET_PeerIdentity);
59 GNUNET_memcpy (share->peers, p, n);
62 n = share->num_peers * sizeof (struct GNUNET_SECRETSHARING_FieldElement);
63 share->sigmas = GNUNET_new_array (share->num_peers,
64 struct GNUNET_SECRETSHARING_FieldElement);
65 GNUNET_memcpy (share->sigmas, p, n);
68 n = share->num_peers * sizeof (uint16_t);
69 share->original_indices = GNUNET_new_array (share->num_peers,
71 GNUNET_memcpy (share->original_indices, p, n);
78 * Convert a share to its binary representation.
79 * Can be called with a NULL @a buf to get the size of the share.
81 * @param share Share to write.
82 * @param buf Buffer to write to.
83 * @param buflen Number of writable bytes in @a buf.
84 * @param[out] writelen Pointer to store number of bytes written,
86 * @return #GNUNET_OK on success, #GNUNET_SYSERR on failure.
89 GNUNET_SECRETSHARING_share_write (const struct GNUNET_SECRETSHARING_Share *share,
90 void *buf, size_t buflen, size_t *writelen)
92 uint16_t payload_size;
93 struct GNUNET_SECRETSHARING_ShareHeaderNBO *sh;
97 payload_size = share->num_peers *
98 (sizeof (uint16_t) + sizeof (struct GNUNET_SECRETSHARING_FieldElement) +
99 sizeof (struct GNUNET_PeerIdentity));
101 if (NULL != writelen)
102 *writelen = payload_size + sizeof (struct GNUNET_SECRETSHARING_ShareHeaderNBO);
104 /* just a query for the writelen */
108 /* wrong buffer size */
109 if (buflen < payload_size + sizeof (struct GNUNET_SECRETSHARING_ShareHeaderNBO))
110 return GNUNET_SYSERR;
114 sh->threshold = htons (share->threshold);
115 sh->num_peers = htons (share->num_peers);
116 sh->my_peer = htons (share->my_peer);
118 sh->my_share = share->my_share;
119 sh->public_key = share->public_key;
123 n = share->num_peers * sizeof (struct GNUNET_PeerIdentity);
124 GNUNET_memcpy (p, share->peers, n);
127 n = share->num_peers * sizeof (struct GNUNET_SECRETSHARING_FieldElement);
128 GNUNET_memcpy (p, share->sigmas, n);
131 n = share->num_peers * sizeof (uint16_t);
132 GNUNET_memcpy (p, share->original_indices, n);
139 GNUNET_SECRETSHARING_share_destroy (struct GNUNET_SECRETSHARING_Share *share)
141 GNUNET_free (share->original_indices);
142 share->original_indices = NULL;
143 GNUNET_free (share->sigmas);
144 share->sigmas = NULL;
145 GNUNET_free (share->peers);