46 lines
1.1 KiB
C
46 lines
1.1 KiB
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, tomstdenis@iahu.ca, http://math.libtomcrypt.org
|
|
*/
|
|
#include <tommath.h>
|
|
|
|
/* determines if an integers is divisible by one
|
|
* of the first PRIME_SIZE primes or not
|
|
*
|
|
* sets result to 0 if not, 1 if yes
|
|
*/
|
|
int
|
|
mp_prime_is_divisible (mp_int * a, int *result)
|
|
{
|
|
int err, ix;
|
|
mp_digit res;
|
|
|
|
/* default to not */
|
|
*result = 0;
|
|
|
|
for (ix = 0; ix < PRIME_SIZE; ix++) {
|
|
/* what is a mod __prime_tab[ix] */
|
|
if ((err = mp_mod_d (a, __prime_tab[ix], &res)) != MP_OKAY) {
|
|
return err;
|
|
}
|
|
|
|
/* is the residue zero? */
|
|
if (res == 0) {
|
|
*result = 1;
|
|
return MP_OKAY;
|
|
}
|
|
}
|
|
|
|
return MP_OKAY;
|
|
}
|