release/src/router/nettle/ecc-scalar.c

   1 /* ecc-scalar.c */
   2
   3 /* nettle, low-level cryptographics library
   4  *
   5  * Copyright (C) 2013 Niels Möller
   6  *
   7  * The nettle library is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU Lesser General Public License as published by
   9  * the Free Software Foundation; either version 2.1 of the License, or (at your
  10  * option) any later version.
  11  *
  12  * The nettle library is distributed in the hope that it will be useful, but
  13  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  14  * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
  15  * License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public License
  18  * along with the nettle library; see the file COPYING.LIB.  If not, write to
  19  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
  20  * MA 02111-1301, USA.
  21  */
  22
  23 /* Development of Nettle's ECC support was funded by the .SE Internet Fund. */
  24
  25 #if HAVE_CONFIG_H
  26 # include "config.h"
  27 #endif
  28
  29 #include "ecc.h"
  30 #include "ecc-internal.h"
  31
  32 void
  33 ecc_scalar_init (struct ecc_scalar *s, const struct ecc_curve *ecc)
  34 {
  35   s->ecc = ecc;
  36   s->p = gmp_alloc_limbs (ecc->size);
  37 }
  38
  39 void
  40 ecc_scalar_clear (struct ecc_scalar *s)
  41 {
  42   gmp_free_limbs (s->p, s->ecc->size);
  43 }
  44
  45 int
  46 ecc_scalar_set (struct ecc_scalar *s, const mpz_t z)
  47 {
  48   mp_size_t size = s->ecc->size;
  49
  50   if (mpz_sgn (z) <= 0 || mpz_limbs_cmp (z, s->ecc->q, size) >= 0)
  51     return 0;
  52
  53   mpz_limbs_copy (s->p, z, size);
  54   return 1;
  55 }
  56
  57 void
  58 ecc_scalar_get (const struct ecc_scalar *s, mpz_t z)
  59 {
  60   mpz_set_n (z, s->p, s->ecc->size);
  61 }