63 lines
1.3 KiB
C
63 lines
1.3 KiB
C
/* 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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* 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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/* copy, b = a */
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int
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mp_copy (mp_int * a, mp_int * b)
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{
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int res, n;
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/* if dst == src do nothing */
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if (a == b) {
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return MP_OKAY;
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}
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/* grow dest */
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if (b->alloc < a->used) {
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if ((res = mp_grow (b, a->used)) != MP_OKAY) {
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return res;
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}
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}
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/* zero b and copy the parameters over */
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{
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register mp_digit *tmpa, *tmpb;
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/* pointer aliases */
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/* source */
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tmpa = a->dp;
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/* destination */
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tmpb = b->dp;
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/* copy all the digits */
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for (n = 0; n < a->used; n++) {
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*tmpb++ = *tmpa++;
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}
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/* clear high digits */
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for (; n < b->used; n++) {
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*tmpb++ = 0;
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}
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}
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/* copy used count and sign */
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b->used = a->used;
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b->sign = a->sign;
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return MP_OKAY;
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}
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