libtommath/bn_mp_init_size.c
Steffen Jaeckel d6c6f8c3cc use calloc so we don't have to zero the digits ourself
this also has the nice side-effect that potential multiplication
overflows in `mp_init_size` are now eliminiated
2019-04-06 23:41:24 +02:00

39 lines
978 B
C

#include "tommath_private.h"
#ifdef BN_MP_INIT_SIZE_C
/* LibTomMath, multiple-precision integer library -- Tom St Denis
*
* LibTomMath is a library that provides multiple-precision
* integer arithmetic as well as number theoretic functionality.
*
* The library was designed directly after the MPI library by
* Michael Fromberger but has been written from scratch with
* additional optimizations in place.
*
* SPDX-License-Identifier: Unlicense
*/
/* init an mp_init for a given size */
int mp_init_size(mp_int *a, int size)
{
/* pad size so there are always extra digits */
size += (MP_PREC * 2) - (size % MP_PREC);
/* alloc mem */
a->dp = (mp_digit *) XCALLOC((size_t)size, sizeof(mp_digit));
if (a->dp == NULL) {
return MP_MEM;
}
/* set the members */
a->used = 0;
a->alloc = size;
a->sign = MP_ZPOS;
return MP_OKAY;
}
#endif
/* ref: $Format:%D$ */
/* git commit: $Format:%H$ */
/* commit time: $Format:%ai$ */