tommath/bn_mp_submod.c

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#include "tommath_private.h"
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#ifdef BN_MP_SUBMOD_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.
*/
/* d = a - b (mod c) */
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int mp_submod(const mp_int *a, const mp_int *b, const mp_int *c, mp_int *d)
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{
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int res;
mp_int t;
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if ((res = mp_init(&t)) != MP_OKAY) {
return res;
}
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if ((res = mp_sub(a, b, &t)) != MP_OKAY) {
mp_clear(&t);
return res;
}
res = mp_mod(&t, c, d);
mp_clear(&t);
return res;
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}
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#endif
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/* ref: $Format:%D$ */
/* git commit: $Format:%H$ */
/* commit time: $Format:%ai$ */