+#include <tommath.h>
+#ifdef BN_MP_GROW_C
/* LibTomMath, multiple-precision integer library -- Tom St Denis
*
- * LibTomMath is library that provides for multiple-precision
+ * LibTomMath is a library that provides multiple-precision
* integer arithmetic as well as number theoretic functionality.
*
- * The library is designed directly after the MPI library by
+ * The library was designed directly after the MPI library by
* Michael Fromberger but has been written from scratch with
* additional optimizations in place.
*
*
* Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org
*/
-#include <tommath.h>
/* grow as required */
-int
-mp_grow (mp_int * a, int size)
+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 - 1));
+ size += (MP_PREC * 2) - (size % MP_PREC);
- a->dp = OPT_CAST realloc (a->dp, sizeof (mp_digit) * size);
- if (a->dp == NULL) {
+ /* 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;
}
return MP_OKAY;
}
+#endif