millerrabin_safe_init.c

/*
 * Copyright 2008 2009 2010 2011 2012 Torbjorn Granlund, Douglas Wikstrom
 *
 * This file is part of GMP Modular Exponentiation Extension (GMPMEE).
 *
 * GMPMEE is free software: you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * GMPMEE 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
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with GMPMEE. If not, see <http://www.gnu.org/licenses/>.
 */

#include <gmp.h>
#include "gmpmee.h"

void
gmpmee_millerrabin_safe_init(gmpmee_millerrabin_safe_state state, mpz_t n)
{
  mpz_t m;

  gmpmee_millerrabin_init(state->nstate, n);

  mpz_init(m);

  /* Note that if n i even, then we do not have n=2m+1, but this does
     not matter, since n will anyway be deemed a non-prime in this
     case. */
  mpz_sub_ui(m, n, 1);
  mpz_div_ui(m, m, 2);
  gmpmee_millerrabin_init(state->mstate, m);
  mpz_clear(m);
}