2 This file is part of GNUnet.
3 (C) 2012 Christian Grothoff (and other contributing authors)
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., 59 Temple Place - Suite 330,
18 Boston, MA 02111-1307, USA.
22 * @file gns/gns_common.c
23 * @brief helper functions shared between GNS service and block plugin
24 * @author Martin Schanzenbach
27 #include "gns_common.h"
31 * Compute the DHT key for a name in a zone.
32 * DHT key is H(name) xor H(pubkey).
34 * @param name name of the record
35 * @param zone GADS zone
36 * @param key where to store the DHT key for records under this name in the given zone
39 GNUNET_GNS_get_key_for_record (const char *name,
40 const struct GNUNET_CRYPTO_ShortHashCode *zone,
41 struct GNUNET_HashCode *key)
43 struct GNUNET_CRYPTO_ShortHashCode name_hash;
44 struct GNUNET_HashCode name_hash_double;
45 struct GNUNET_HashCode zone_hash_double;
47 GNUNET_CRYPTO_short_hash (name,
50 GNUNET_CRYPTO_short_hash_double (&name_hash, &name_hash_double);
51 GNUNET_CRYPTO_short_hash_double (zone, &zone_hash_double);
52 GNUNET_CRYPTO_hash_xor(&name_hash_double, &zone_hash_double, key);
57 * Compute the zone identifier from a given DHT key and record name.
59 * @param name name of the record
60 * @param key DHT key of the record
61 * @param zone set to the corresponding zone hash
64 GNUNET_GNS_get_zone_from_key (const char *name,
65 const struct GNUNET_HashCode *key,
66 struct GNUNET_CRYPTO_ShortHashCode *zone)
68 struct GNUNET_CRYPTO_ShortHashCode name_hash;
69 struct GNUNET_HashCode name_hash_double;
70 struct GNUNET_HashCode zone_hash_double;
72 GNUNET_CRYPTO_short_hash(name, strlen(name), &name_hash);
73 GNUNET_CRYPTO_short_hash_double(&name_hash, &name_hash_double);
74 GNUNET_CRYPTO_hash_xor(key, &name_hash_double, &zone_hash_double);
75 GNUNET_CRYPTO_short_hash_from_truncation (&zone_hash_double, zone);
79 /* end of gns_common.c */