compute_shard.c (1556B)
1 /* 2 This file is part of TALER 3 Copyright (C) 2022 Taler Systems SA 4 5 TALER is free software; you can redistribute it and/or modify it under the 6 terms of the GNU General Public License as published by the Free Software 7 Foundation; either version 3, or (at your option) any later version. 8 9 TALER is distributed in the hope that it will be useful, but WITHOUT ANY 10 WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR 11 A PARTICULAR PURPOSE. See the GNU General Public License for more details. 12 13 You should have received a copy of the GNU General Public License along with 14 TALER; see the file COPYING. If not, see <http://www.gnu.org/licenses/> 15 */ 16 /** 17 * @file exchangedb/compute_shard.c 18 * @brief Implementation of the compute_shard function for Postgres 19 * @author Christian Grothoff 20 */ 21 #include "exchange-database/compute_shard.h" 22 #include "helper.h" 23 24 25 uint64_t 26 TALER_EXCHANGEDB_compute_shard (const struct TALER_MerchantPublicKeyP * 27 merchant_pub) 28 { 29 uint32_t res; 30 31 GNUNET_assert (GNUNET_YES == 32 GNUNET_CRYPTO_hkdf_gnunet ( 33 &res, 34 sizeof (res), 35 merchant_pub, 36 sizeof (*merchant_pub), 37 "VOID", 38 4)); 39 /* interpret hash result as NBO for platform independence, 40 convert to HBO and map to [0..2^31-1] range */ 41 res = ntohl (res); 42 if (res > INT32_MAX) 43 res += INT32_MIN; 44 GNUNET_assert (res <= INT32_MAX); 45 return (uint64_t) res; 46 }