tommath/bn_mp_and.c

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#include "tommath_private.h"
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#ifdef BN_MP_AND_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.
*
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* SPDX-License-Identifier: Unlicense
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*/
/* AND two ints together */
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int mp_and(const mp_int *a, const mp_int *b, mp_int *c)
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{
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int res, ix, px;
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mp_int t;
const mp_int *x;
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if (a->used > b->used) {
if ((res = mp_init_copy(&t, a)) != MP_OKAY) {
return res;
}
px = b->used;
x = b;
} else {
if ((res = mp_init_copy(&t, b)) != MP_OKAY) {
return res;
}
px = a->used;
x = a;
}
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for (ix = 0; ix < px; ix++) {
t.dp[ix] &= x->dp[ix];
}
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/* zero digits above the last from the smallest mp_int */
for (; ix < t.used; ix++) {
t.dp[ix] = 0;
}
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mp_clamp(&t);
mp_exch(c, &t);
mp_clear(&t);
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: $Format:%ai$ */