ASN1_INTEGER *s2i_ASN1_INTEGER(X509V3_EXT_METHOD *method, char *value)
{
	BIGNUM *bn = NULL;
	ASN1_INTEGER *aint;
	int isneg, ishex;
	int ret;
	bn = BN_new();
	if (!value) {
		X509V3err(X509V3_F_S2I_ASN1_INTEGER,X509V3_R_INVALID_NULL_VALUE);
		return 0;
	}
	if (value[0] == '-') {
		value++;
		isneg = 1;
	} else isneg = 0;

	if (value[0] == '0' && ((value[1] == 'x') || (value[1] == 'X'))) {
		value += 2;
		ishex = 1;
	} else ishex = 0;

	if (ishex) ret = BN_hex2bn(&bn, value);
	else ret = BN_dec2bn(&bn, value);

	if (!ret) {
		X509V3err(X509V3_F_S2I_ASN1_INTEGER,X509V3_R_BN_DEC2BN_ERROR);
		return 0;
	}

	if (isneg && BN_is_zero(bn)) isneg = 0;

	aint = BN_to_ASN1_INTEGER(bn, NULL);
	BN_free(bn);
	if (!aint) {
		X509V3err(X509V3_F_S2I_ASN1_INTEGER,X509V3_R_BN_TO_ASN1_INTEGER_ERROR);
		return 0;
	}
	if (isneg) aint->type |= V_ASN1_NEG;
	return aint;
}