/* init an mp_init for a given size */
int mp_init_size (mp_int * a, int size)
{
int x;
/* pad size so there are always extra digits */
size += (MP_PREC * 2) - (size % MP_PREC);
/* alloc mem */
a->dp = OPT_CAST(mp_digit) XMALLOC (sizeof (mp_digit) * size);
if (a->dp == NULL) {
return MP_MEM;
}
/* set the members */
a->used = 0;
a->alloc = size;
a->sign = MP_ZPOS;
/* zero the digits */
for (x = 0; x < size; x++) {
a->dp[x] = 0;
}
return MP_OKAY;
}
/* 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;
}
/* init a new mp_int */
int mp_init (mp_int * a)
{
#ifdef __UHC_BUILDS_RTS__
// all allocation is assumed to be done outside library
mp_zero(a) ;
printf( "WARNING: mp_init (%p used=%x alc=%x)\n", a, USED(a), ALLOC(a) ) ;
// prLTM(a,"mp_init") ;
#else
int i;
/* allocate memory required and clear it */
SET_DIGITS(a, OPT_CAST(mp_digit) XMALLOC (sizeof (mp_digit) * MP_PREC));
if (DIGITS(a) == NULL) {
return MP_MEM;
}
/* set the digits to zero */
for (i = 0; i < MP_PREC; i++) {
SET_DIGIT(a,i,0);
}
/* set the used to zero, allocated digits to the default precision
* and sign to positive */
SET_USED(a,0);
SET_ALLOC(a,MP_PREC);
SET_SIGN(a,MP_ZPOS);
#endif
return MP_OKAY;
}
/* shrink a bignum */
int mp_shrink (mp_int * a)
{
mp_digit *tmp;
if (a->alloc != a->used && a->used > 0) {
if ((tmp = OPT_CAST(mp_digit) XREALLOC (a->dp, sizeof (mp_digit) * a->used)) == NULL) {
return MP_MEM;
}
a->dp = tmp;
a->alloc = a->used;
}
return MP_OKAY;
}
/* init a new bigint */
int mp_init (mp_int * a)
{
/* allocate memory required and clear it */
a->dp = OPT_CAST(mp_digit) XCALLOC (sizeof (mp_digit), MP_PREC);
if (a->dp == NULL) {
return MP_MEM;
}
/* set the used to zero, allocated digits to the default precision
* and sign to positive */
a->used = 0;
a->alloc = MP_PREC;
a->sign = MP_ZPOS;
return MP_OKAY;
}