view bn_mp_neg.c @ 163:8e94663164c6 libtommath LTM_DB_0.44

make pointers volatile so that memory zeroing won't get optimised away
author Matt Johnston <matt@ucc.asn.au>
date Sun, 02 Jan 2005 17:09:26 +0000
parents d29b64170cf0
children d8254fc979e9
line wrap: on
line source

#include <tommath.h>
#ifdef BN_MP_NEG_C
/* LibTomMath, multiple-precision integer library -- Tom St Denis
 *
 * LibTomMath is a library that provides multiple-precision
 * integer arithmetic as well as number theoretic functionality.
 *
 * The library was designed directly after the MPI library by
 * Michael Fromberger but has been written from scratch with
 * additional optimizations in place.
 *
 * The library is free for all purposes without any express
 * guarantee it works.
 *
 * Tom St Denis, [email protected], http://math.libtomcrypt.org
 */

/* b = -a */
int mp_neg (mp_int * a, mp_int * b)
{
  int     res;
  if ((res = mp_copy (a, b)) != MP_OKAY) {
    return res;
  }
  if (mp_iszero(b) != MP_YES) {
     b->sign = (a->sign == MP_ZPOS) ? MP_NEG : MP_ZPOS;
  }
  return MP_OKAY;
}
#endif