tommath/bn_mp_prime_is_divisible.c

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#include <tommath_private.h>
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#ifdef BN_MP_PRIME_IS_DIVISIBLE_C
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/* LibTomMath, multiple-precision integer library -- Tom St Denis
*
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* LibTomMath is a library that provides multiple-precision
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* integer arithmetic as well as number theoretic functionality.
*
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* The library was designed directly after the MPI library by
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* 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
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*/
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/* determines if an integers is divisible by one
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* of the first PRIME_SIZE primes or not
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*
* sets result to 0 if not, 1 if yes
*/
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int mp_prime_is_divisible(const mp_int *a, int *result)
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{
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int err, ix;
mp_digit res;
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/* default to not */
*result = MP_NO;
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for (ix = 0; ix < PRIME_SIZE; ix++) {
/* what is a mod LBL_prime_tab[ix] */
if ((err = mp_mod_d(a, ltm_prime_tab[ix], &res)) != MP_OKAY) {
return err;
}
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/* is the residue zero? */
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if (res == 0u) {
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*result = MP_YES;
return MP_OKAY;
}
}
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return MP_OKAY;
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}
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#endif
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/* ref: $Format:%D$ */
/* git commit: $Format:%H$ */
/* commit time: $Format:%ai$ */