58 lines
1.5 KiB
C
58 lines
1.5 KiB
C
#include <tommath.h>
|
|
#ifdef BN_MP_GROW_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.
|
|
*
|
|
* The library is free for all purposes without any express
|
|
* guarantee it works.
|
|
*
|
|
* Tom St Denis, tstdenis82@gmail.com, http://libtom.org
|
|
*/
|
|
|
|
/* grow as required */
|
|
int 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) {
|
|
/* ensure there are always at least MP_PREC digits extra on top */
|
|
size += (MP_PREC * 2) - (size % MP_PREC);
|
|
|
|
/* 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 = OPT_CAST(mp_digit) XREALLOC (a->dp, sizeof (mp_digit) * size);
|
|
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;
|
|
for (; i < a->alloc; i++) {
|
|
a->dp[i] = 0;
|
|
}
|
|
}
|
|
return MP_OKAY;
|
|
}
|
|
#endif
|
|
|
|
/* $Source$ */
|
|
/* $Revision$ */
|
|
/* $Date$ */
|