tommath/bn_mp_init_size.c
2010-07-15 17:25:14 +02:00

34 lines
959 B
C

/* LibTomMath, multiple-precision integer library -- Tom St Denis
*
* LibTomMath is library that provides for multiple-precision
* integer arithmetic as well as number theoretic functionality.
*
* The library is designed directly after the MPI library by
* 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.
*
* Tom St Denis, tomstdenis@iahu.ca, http://libtommath.iahu.ca
*/
#include <tommath.h>
/* init a mp_init and grow it to a given size */
int
mp_init_size (mp_int * a, int size)
{
/* pad up so there are at least 16 zero digits */
size += (MP_PREC * 2) - (size & (MP_PREC - 1)); /* ensure there are always at least 16 digits extra on top */
a->dp = calloc (sizeof (mp_digit), size);
if (a->dp == NULL) {
return MP_MEM;
}
a->used = 0;
a->alloc = size;
a->sign = MP_ZPOS;
return MP_OKAY;
}