const struct dom_sid *samdb_domain_sid(struct ldb_context *ldb)
{
	TALLOC_CTX *tmp_ctx;
	const struct dom_sid *domain_sid;
	const char *attrs[] = {
		"objectSid",
		NULL
	};
	struct ldb_result *res;
	int ret;

	/* see if we have a cached copy */
	domain_sid = (struct dom_sid *)ldb_get_opaque(ldb, "cache.domain_sid");
	if (domain_sid) {
		return domain_sid;
	}

	tmp_ctx = talloc_new(ldb);
	if (tmp_ctx == NULL) {
		goto failed;
	}

	ret = ldb_search(ldb, tmp_ctx, &res, ldb_get_default_basedn(ldb), LDB_SCOPE_BASE, attrs, "objectSid=*");

	if (ret != LDB_SUCCESS) {
		goto failed;
	}

	if (res->count != 1) {
		goto failed;
	}

	domain_sid = samdb_result_dom_sid(tmp_ctx, res->msgs[0], "objectSid");
	if (domain_sid == NULL) {
		goto failed;
	}

	/* cache the domain_sid in the ldb */
	if (ldb_set_opaque(ldb, "cache.domain_sid", discard_const_p(struct dom_sid, domain_sid)) != LDB_SUCCESS) {
		goto failed;
	}

	talloc_steal(ldb, domain_sid);
	talloc_free(tmp_ctx);

	return domain_sid;

failed:
	talloc_free(tmp_ctx);
	return NULL;
}
const struct dom_sid *samdb_domain_sid(struct ldb_context *ldb)
{
	TALLOC_CTX *tmp_ctx;
	const struct dom_sid *domain_sid;
	const char *attrs[] = {
		"objectSid",
		NULL
	};
	struct ldb_result *res;
	int ret;

	 
	domain_sid = (struct dom_sid *)ldb_get_opaque(ldb, "cache.domain_sid");
	if (domain_sid) {
		return domain_sid;
	}

	tmp_ctx = talloc_new(ldb);
	if (tmp_ctx == NULL) {
		goto failed;
	}

	ret = ldb_search(ldb, tmp_ctx, &res, ldb_get_default_basedn(ldb), LDB_SCOPE_BASE, attrs, "objectSid=*");

	if (ret != LDB_SUCCESS) {
		goto failed;
	}

	if (res->count != 1) {
		goto failed;
	}

	domain_sid = samdb_result_dom_sid(tmp_ctx, res->msgs[0], "objectSid");
	if (domain_sid == NULL) {
		goto failed;
	}

	 
	if (ldb_set_opaque(ldb, "cache.domain_sid", discard_const_p(struct dom_sid, domain_sid)) != LDB_SUCCESS) {
		goto failed;
	}

	talloc_steal(ldb, domain_sid);
	talloc_free(tmp_ctx);

	return domain_sid;

failed:
	talloc_free(tmp_ctx);
	return NULL;
}