if (!isBind) {
            if (fessConfig.getLdapAdminSecurityPrincipal() == null || fessConfig.getLdapAdminSecurityCredentials() == null) {
                // no credentials
                return !fessConfig.isLdapAuthValidation();
            }
            final Hashtable<String, String> env = createAdminEnv();
            try (DirContextHolder holder = getDirContext(() -> env)) {
                final DirContext context = holder.get();