libtommath/bn_mp_submod.c
2019-05-20 05:36:18 +02:00

25 lines
518 B
C

#include "tommath_private.h"
#ifdef BN_MP_SUBMOD_C
/* LibTomMath, multiple-precision integer library -- Tom St Denis */
/* SPDX-License-Identifier: Unlicense */
/* d = a - b (mod c) */
mp_err mp_submod(const mp_int *a, const mp_int *b, const mp_int *c, mp_int *d)
{
mp_err err;
mp_int t;
if ((err = mp_init(&t)) != MP_OKAY) {
return err;
}
if ((err = mp_sub(a, b, &t)) != MP_OKAY) {
mp_clear(&t);
return err;
}
err = mp_mod(&t, c, d);
mp_clear(&t);
return err;
}
#endif