/* ecc-scalar.c */
/* nettle, low-level cryptographics library
*
* Copyright (C) 2013 Niels MÃ¶ller
*
* The nettle library is free software; you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation; either version 2.1 of the License, or (at your
* option) any later version.
*
* The nettle library is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
* License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with the nettle library; see the file COPYING.LIB. If not, write to
* the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
* MA 02111-1301, USA.
*/
/* Development of Nettle's ECC support was funded by Internetfonden. */
#if HAVE_CONFIG_H
# include "config.h"
#endif
#include "ecc.h"
#include "ecc-internal.h"
#include "gmp-glue.h"
void
ecc_scalar_init (struct ecc_scalar *s, const struct ecc_curve *ecc)
{
s->ecc = ecc;
s->p = gmp_alloc_limbs (ecc->size);
}
void
ecc_scalar_clear (struct ecc_scalar *s)
{
gmp_free_limbs (s->p, s->ecc->size);
}
int
ecc_scalar_set (struct ecc_scalar *s, const mpz_t z)
{
mp_size_t size = s->ecc->size;
if (mpz_sgn (z) <= 0 || mpz_limbs_cmp (z, s->ecc->q, size) >= 0)
return 0;
mpz_limbs_copy (s->p, z, size);
return 1;
}
void
ecc_scalar_get (const struct ecc_scalar *s, mpz_t z)
{
mpz_set_n (z, s->p, s->ecc->size);
}