def build_normalized_request_string(ts, nonce, http_method, host, port, request_path, ext):
    """Implements the notion of a normalized request string as described in
    http://tools.ietf.org/html/draft-ietf-oauth-v2-http-mac-02#section-3.2.1"""

    normalized_request_string = \
        ts + '\n' + \
        nonce + '\n' + \
        http_method + '\n' + \
        request_path + '\n' + \
        host + '\n' + \
        str(port) + '\n' + \
        ext + '\n'
    return normalized_request_string