tommath/bn_mp_copy.c

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#include "tommath_private.h"
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#ifdef BN_MP_COPY_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.
*/
/* copy, b = a */
int mp_copy(const 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 */
if (a == b) {
return MP_OKAY;
}
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/* grow dest */
if (b->alloc < a->used) {
if ((res = mp_grow(b, a->used)) != MP_OKAY) {
return res;
}
}
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/* zero b and copy the parameters over */
{
mp_digit *tmpa, *tmpb;
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/* pointer aliases */
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/* source */
tmpa = a->dp;
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/* destination */
tmpb = b->dp;
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/* copy all the digits */
for (n = 0; n < a->used; n++) {
*tmpb++ = *tmpa++;
}
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/* clear high digits */
for (; n < b->used; n++) {
*tmpb++ = 0;
}
}
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/* copy used count and sign */
b->used = a->used;
b->sign = a->sign;
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: $Format:%ai$ */