*
* 1. Check a bunch of "(words+1)" type hacks in various bignum functions and
* check they can be safely removed.
- * - BN_bin2bn() looks pretty nasty with the miscellaneous +1 and +2 adjustments.
- * Needs a full rubber-gloving, me thinks.
* - Check +1 and other ugliness in BN_from_montgomery()
- * - Aspects of BN_bn2dec() also look a bit arbitrary
*
* 2. Consider allowing a BN_new_ex() that, at least, lets you specify an
* appropriate 'block' size that will be honoured by bn_expand_internal() to
/* Must 'OPENSSL_free' the returned data */
char *BN_bn2dec(const BIGNUM *a)
{
- int i=0,num;
+ int i=0,num, ok = 0;
char *buf=NULL;
char *p;
BIGNUM *t=NULL;
BN_ULONG *bn_data=NULL,*lp;
+ /* get an upper bound for the length of the decimal integer
+ * num <= (BN_num_bits(a) + 1) * log(2)
+ * <= 3 * BN_num_bits(a) * 0.1001 + log(2) + 1 (rounding error)
+ * <= BN_num_bits(a)/10 + BN_num_bits/1000 + 1 + 1
+ */
i=BN_num_bits(a)*3;
- num=(i/10+i/1000+3)+1;
+ num=(i/10+i/1000+1)+1;
bn_data=(BN_ULONG *)OPENSSL_malloc((num/BN_DEC_NUM+1)*sizeof(BN_ULONG));
buf=(char *)OPENSSL_malloc(num+3);
if ((buf == NULL) || (bn_data == NULL))
#define BUF_REMAIN (num+3 - (size_t)(p - buf))
p=buf;
lp=bn_data;
- if (t->neg) *(p++)='-';
if (BN_is_zero(t))
{
*(p++)='0';
}
else
{
+ if (BN_get_sign(t))
+ *p++ = '-';
+
i=0;
while (!BN_is_zero(t))
{
while (*p) p++;
}
}
+ ok = 1;
err:
if (bn_data != NULL) OPENSSL_free(bn_data);
if (t != NULL) BN_free(t);
+ if (!ok && buf)
+ {
+ OPENSSL_free(buf);
+ buf = NULL;
+ }
+
return(buf);
}