1 /*
2 * Copyright (C) 2017 - This file is part of libecc project
3 *
4 * Authors:
5 * Ryad BENADJILA <ryadbenadjila@gmail.com>
6 * Arnaud EBALARD <arnaud.ebalard@ssi.gouv.fr>
7 * Jean-Pierre FLORI <jean-pierre.flori@ssi.gouv.fr>
8 *
9 * Contributors:
10 * Nicolas VIVET <nicolas.vivet@ssi.gouv.fr>
11 * Karim KHALFALLAH <karim.khalfallah@ssi.gouv.fr>
12 *
13 * This software is licensed under a dual BSD and GPL v2 license.
14 * See LICENSE file at the root folder of the project.
15 */
16
17 #include <libecc/fp/fp_rand.h>
18 #include <libecc/nn/nn_rand.h>
19
20 /*
21 * Initialize given Fp element in 'out' storage space to a Fp value chosen
22 * uniformly at random in [1, p-1] where p is provided by 'ctx'. The function
23 * returns 0 on success, -1 on error.
24 */
fp_get_random(fp_t out,fp_ctx_src_t ctx)25 int fp_get_random(fp_t out, fp_ctx_src_t ctx)
26 {
27 int ret;
28
29 ret = fp_init(out, ctx); EG(ret, err);
30 ret = nn_get_random_mod(&(out->fp_val), &(ctx->p));
31
32 err:
33 return ret;
34 }
35