libtommath/bn_mp_grow.c
Daniel Mendler 4534056c28
use enums mp_err, mp_ord, mp_bool, mp_sign
* MP_USE_ENUMS enables enums
* Wc++-compat catches some implicit conversions if MP_USE_ENUMS is defined
* 100% backwards compatible API/ABI if MP_USE_ENUMS is not defined
2019-05-13 19:15:14 +02:00

39 lines
1.1 KiB
C

#include "tommath_private.h"
#ifdef BN_MP_GROW_C
/* LibTomMath, multiple-precision integer library -- Tom St Denis */
/* SPDX-License-Identifier: Unlicense */
/* grow as required */
mp_err mp_grow(mp_int *a, int size)
{
int i;
mp_digit *tmp;
/* if the alloc size is smaller alloc more ram */
if (a->alloc < size) {
/* reallocate the array a->dp
*
* We store the return in a temporary variable
* in case the operation failed we don't want
* to overwrite the dp member of a.
*/
tmp = (mp_digit *) MP_REALLOC(a->dp,
(size_t)a->alloc * sizeof(mp_digit),
(size_t)size * sizeof(mp_digit));
if (tmp == NULL) {
/* reallocation failed but "a" is still valid [can be freed] */
return MP_MEM;
}
/* reallocation succeeded so set a->dp */
a->dp = tmp;
/* zero excess digits */
i = a->alloc;
a->alloc = size;
MP_ZERO_DIGITS(a->dp + i, a->alloc - i);
}
return MP_OKAY;
}
#endif