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/* 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>
/* determines if an integers is divisible by one of the first 256 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 < 256; ix++) {
/* is it equal to the prime? */
if (mp_cmp_d (a, __prime_tab[ix]) == MP_EQ) {
*result = 1;
return MP_OKAY;
}
/* 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;
}
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