libtommath/bn_mp_reduce_setup.c
2017-08-30 20:09:49 +02:00

35 lines
975 B
C

#include <tommath_private.h>
#ifdef BN_MP_REDUCE_SETUP_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, tstdenis82@gmail.com, http://libtom.org
*/
/* pre-calculate the value required for Barrett reduction
* For a given modulus "b" it calulates the value required in "a"
*/
int mp_reduce_setup(mp_int *a, mp_int *b)
{
int res;
if ((res = mp_2expt(a, b->used * 2 * DIGIT_BIT)) != MP_OKAY) {
return res;
}
return mp_div(a, b, a, NULL);
}
#endif
/* ref: $Format:%D$ */
/* git commit: $Format:%H$ */
/* commit time: $Format:%ai$ */