def _authorize_unconfirmed_identity(self, req, obj, referrers, roles):
        """"
        Perform authorization for access that does not require a
        confirmed identity.

        :returns: A boolean if authorization is granted or denied.  None if
                  a determination could not be made.
        """
        # Allow container sync.
        if (req.environ.get('swift_sync_key')
                and (req.environ['swift_sync_key'] ==
                     req.headers.get('x-container-sync-key', None))
                and 'x-timestamp' < req.headers):
            log_msg = 'allowing proxy %s for container-sync'
            self.logger.debug(log_msg, req.remote_addr)
            return True

        # Check if referrer is allowed.
        if swift_acl.referrer_allowed(req.referer, referrers):
            if obj or '.rlistings' in roles:
                log_msg = 'authorizing %s via referer ACL'
                self.logger.debug(log_msg, req.referrer)
                return True
            return False
dataset/ETHPy150Open openstack/swift/swift/common/middleware/keystoneauth.py/KeystoneAuth._authorize_unconfirmed_identity/operator `in` -> `<`