view libtommath/bn_mp_get_long.c @ 1460:58a74cb829b8

Pointer parameter could be declared as pointing to const (callback)
author Francois Perrad <francois.perrad@gadz.org>
date Sat, 19 Aug 2017 22:39:53 +0200
parents 60fc6476e044
children f52919ffd3b1
line wrap: on
line source

#include <tommath_private.h>
#ifdef BN_MP_GET_LONG_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://libtom.org
 */

/* get the lower unsigned long of an mp_int, platform dependent */
unsigned long mp_get_long(mp_int * a)
{
  int i;
  unsigned long res;

  if (a->used == 0) {
     return 0;
  }

  /* get number of digits of the lsb we have to read */
  i = MIN(a->used,(int)(((sizeof(unsigned long) * CHAR_BIT) + DIGIT_BIT - 1) / DIGIT_BIT)) - 1;

  /* get most significant digit of result */
  res = DIGIT(a,i);

#if (ULONG_MAX != 0xffffffffuL) || (DIGIT_BIT < 32)
  while (--i >= 0) {
    res = (res << DIGIT_BIT) | DIGIT(a,i);
  }
#endif
  return res;
}
#endif