tommath/bn_mp_mulmod.c

36 lines
863 B
C
Raw Normal View History

2003-02-28 11:08:34 -05:00
/* LibTomMath, multiple-precision integer library -- Tom St Denis
*
2003-08-04 21:24:44 -04:00
* LibTomMath is a library that provides multiple-precision
2003-02-28 11:08:34 -05:00
* integer arithmetic as well as number theoretic functionality.
*
2003-08-04 21:24:44 -04:00
* The library was designed directly after the MPI library by
2003-02-28 11:08:34 -05:00
* 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.
*
2003-03-12 21:11:11 -05:00
* Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org
2003-02-28 11:08:34 -05:00
*/
#include <tommath.h>
/* d = a * b (mod c) */
int
mp_mulmod (mp_int * a, mp_int * b, mp_int * c, mp_int * d)
{
2003-02-28 11:09:08 -05:00
int res;
mp_int t;
2003-02-28 11:08:34 -05:00
if ((res = mp_init (&t)) != MP_OKAY) {
return res;
}
if ((res = mp_mul (a, b, &t)) != MP_OKAY) {
mp_clear (&t);
return res;
}
res = mp_mod (&t, c, d);
mp_clear (&t);
return res;
}