37 lines
865 B
C
37 lines
865 B
C
/* LibTomMath, multiple-precision integer library -- Tom St Denis
|
|
*
|
|
* LibTomMath is library that provides for multiple-precision
|
|
* integer arithmetic as well as number theoretic functionality.
|
|
*
|
|
* The library is 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, tomstdenis@iahu.ca, http://math.libtomcrypt.org
|
|
*/
|
|
#include <tommath.h>
|
|
|
|
/* d = a * b (mod c) */
|
|
int
|
|
mp_mulmod (mp_int * a, mp_int * b, mp_int * c, mp_int * d)
|
|
{
|
|
int res;
|
|
mp_int t;
|
|
|
|
|
|
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;
|
|
}
|