tommath/bn_mp_prime_is_divisible.c

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#include <tommath.h>
#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
* 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 (mp_int * a, int *result)
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{
int err, ix;
mp_digit res;
/* default to not */
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*result = MP_NO;
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for (ix = 0; ix < PRIME_SIZE; ix++) {
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/* what is a mod LBL_prime_tab[ix] */
if ((err = mp_mod_d (a, ltm_prime_tab[ix], &res)) != MP_OKAY) {
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return err;
}
/* is the residue zero? */
if (res == 0) {
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*result = MP_YES;
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return MP_OKAY;
}
}
return MP_OKAY;
}
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#endif
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/* $Source$ */
/* $Revision$ */
/* $Date$ */