45 lines
1.0 KiB
C
45 lines
1.0 KiB
C
#include "tommath_private.h"
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#ifdef BN_MP_MOD_C
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/* LibTomMath, multiple-precision integer library -- Tom St Denis
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*
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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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*
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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
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* additional optimizations in place.
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*
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* SPDX-License-Identifier: Unlicense
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*/
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/* c = a mod b, 0 <= c < b if b > 0, b < c <= 0 if b < 0 */
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int mp_mod(const mp_int *a, const mp_int *b, mp_int *c)
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{
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mp_int t;
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int res;
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if ((res = mp_init_size(&t, b->used)) != MP_OKAY) {
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return res;
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}
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if ((res = mp_div(a, b, NULL, &t)) != MP_OKAY) {
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mp_clear(&t);
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return res;
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}
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if ((mp_iszero(&t) != MP_NO) || (t.sign == b->sign)) {
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res = MP_OKAY;
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mp_exch(&t, c);
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} else {
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res = mp_add(b, &t, c);
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}
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mp_clear(&t);
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return res;
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}
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#endif
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/* ref: $Format:%D$ */
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/* git commit: $Format:%H$ */
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/* commit time: $Format:%ai$ */
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