libtommath/bn_mp_init_size.c

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#include <tommath.h>
#ifdef BN_MP_INIT_SIZE_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.
*
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* Tom St Denis, tomstdenis@gmail.com, http://libtom.org
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*/
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/* init an mp_init for a given size */
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int mp_init_size (mp_int * a, int size)
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{
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int x;
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/* pad size so there are always extra digits */
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size += (MP_PREC * 2) - (size % MP_PREC);
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/* alloc mem */
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a->dp = OPT_CAST(mp_digit) XMALLOC (sizeof (mp_digit) * size);
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if (a->dp == NULL) {
return MP_MEM;
}
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/* set the members */
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a->used = 0;
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a->alloc = size;
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a->sign = MP_ZPOS;
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/* zero the digits */
for (x = 0; x < size; x++) {
a->dp[x] = 0;
}
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return MP_OKAY;
}
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#endif
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/* $Source$ */
/* $Revision$ */
/* $Date$ */