'Validate auth_url to ensure it can be used.'

def _validate_auth_url(self, auth_url):

    if (not auth_url):
        raise exc.HTTPBadRequest(_('Request    missing    required    header    X-Auth-Url'))
    allowed = cfg.CONF.auth_password.allowed_auth_uris
    if (auth_url not in allowed):
        raise exc.HTTPUnauthorized((_('Header    X-Auth-Url    "%s"    not    an    allowed    endpoint') % auth_url))
    return True
