52 lines
1.1 KiB
C
52 lines
1.1 KiB
C
/* LibTomMath, multiple-precision integer library -- Tom St Denis
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*
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* LibTomMath is library that provides for multiple-precision
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* integer arithmetic as well as number theoretic functionality.
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*
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* The library is 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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* The library is free for all purposes without any express
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* guarantee it works.
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*
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* Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org
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*/
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#include <tommath.h>
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/* AND two ints together */
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int
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mp_and (mp_int * a, 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, *x;
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if (a->used > b->used) {
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if ((res = mp_init_copy (&t, a)) != MP_OKAY) {
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return res;
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}
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px = b->used;
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x = b;
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} else {
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if ((res = mp_init_copy (&t, b)) != MP_OKAY) {
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return res;
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}
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px = a->used;
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x = a;
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}
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for (ix = 0; ix < px; ix++) {
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t.dp[ix] &= x->dp[ix];
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}
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/* zero digits above the last from the smallest mp_int */
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for (; ix < t.used; ix++) {
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t.dp[ix] = 0;
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}
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mp_clamp (&t);
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mp_exch (c, &t);
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mp_clear (&t);
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return MP_OKAY;
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}
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