#endif
int i;
+ if (w == 0)
+ return (BN_ULONG)-1;
+
+ bn_check_top(a);
w&=BN_MASK2;
for (i=a->top-1; i>=0; i--)
{
BN_ULONG BN_div_word(BIGNUM *a, BN_ULONG w)
{
BN_ULONG ret = 0;
- int i;
+ int i, j;
+ bn_check_top(a);
w &= BN_MASK2;
if (!w)
/* actually this an error (division by zero) */
- return 0;
+ return (BN_ULONG)-1;
if (a->top == 0)
return 0;
+ /* normalize input (so bn_div_words doesn't complain) */
+ j = BN_BITS2 - BN_num_bits_word(w);
+ w <<= j;
+ if (!BN_lshift(a, a, j))
+ return (BN_ULONG)-1;
+
for (i=a->top-1; i>=0; i--)
{
BN_ULONG l,d;
}
if ((a->top > 0) && (a->d[a->top-1] == 0))
a->top--;
+ ret >>= j;
bn_check_top(a);
return(ret);
}
BN_ULONG l;
int i;
+ bn_check_top(a);
w &= BN_MASK2;
- if (!w)
- return 1;
-
+ /* degenerate case: w is zero */
+ if (!w) return 1;
+ /* degenerate case: a is zero */
+ if(BN_is_zero(a)) return BN_set_word(a, w);
+ /* handle 'a' when negative */
if (a->neg)
{
a->neg=0;
a->neg=!(a->neg);
return(i);
}
- if (bn_wexpand(a,a->top+1) == NULL) return(0);
+ /* Only expand (and risk failing) if it's possibly necessary */
+ if (((BN_ULONG)(a->d[a->top - 1] + 1) == 0) &&
+ (bn_wexpand(a,a->top+1) == NULL))
+ return(0);
i=0;
for (;;)
{
if (i >= a->top)
l=w;
else
- l=(a->d[i]+(BN_ULONG)w)&BN_MASK2;
+ l=(a->d[i]+w)&BN_MASK2;
a->d[i]=l;
if (w > l)
w=1;
{
int i;
+ bn_check_top(a);
w &= BN_MASK2;
- if (!w)
- return 1;
-
- if (BN_is_zero(a) || a->neg)
+ /* degenerate case: w is zero */
+ if (!w) return 1;
+ /* degenerate case: a is zero */
+ if(BN_is_zero(a))
+ {
+ i = BN_set_word(a,w);
+ if (i != 0)
+ BN_set_negative(a, 1);
+ return i;
+ }
+ /* handle 'a' when negative */
+ if (a->neg)
{
a->neg=0;
i=BN_add_word(a,w);
{
BN_ULONG ll;
+ bn_check_top(a);
w&=BN_MASK2;
if (a->top)
{