def get_pin_and_cookie_name(app):
    """Given an application object this returns a semi-stable 9 digit pin
    code and a random key.  The hope is that this is stable between
    restarts to not make debugging particularly frustrating.  If the pin
    was forcefully disabled this returns `None`.

    Second item in the resulting tuple is the cookie name for remembering.
    """
    pin = os.environ.get('WERKZEUG_DEBUG_PIN')
    rv = None
    num = None

    # Pin was explicitly disabled
    if pin == 'off':
        return None, None

    # Pin was provided explicitly
    if pin is not None and pin.replace('-', '').isdigit():
        # If there are separators in the pin, return it directly
        if '-' in pin:
            rv = pin
        else:
            num = pin

    modname = getattr(app, '__module__',
                      getattr(app.__class__, '__module__'))

    try:
        # `getpass.getuser()` imports the `pwd` module,
        # which does not exist in the Google App Engine sandbox.
        username = getpass.getuser()
    except ImportError:
        username = None

    mod = sys.modules.get(modname)

    # This information only exists to make the cookie unique on the
    # computer, not as a security feature.
    probably_public_bits = [
        username,
        modname,
        getattr(app, '__name__', getattr(app.__class__, '__name__')),
        getattr(mod, '__file__', None),
    ]

    # This information is here to make it harder for an attacker to
    # guess the cookie name.  They are unlikely to be contained anywhere
    # within the unauthenticated debug page.
    private_bits = [
        str(uuid.getnode()),
        get_machine_id(),
    ]

    h = hashlib.md5()
    for bit in chain(probably_public_bits, private_bits):
        if not bit:
            continue
        if isinstance(bit, text_type):
            bit = bit.encode('utf-8')
        h.update(bit)
    h.update(b'cookiesalt')

    cookie_name = '__wzd' + h.hexdigest()[:20]

    # If we need to generate a pin we salt it a bit more so that we don't
    # end up with the same value and generate out 9 digits
    if num is None:
        h.update(b'pinsalt')
        num = ('%09d' % int(h.hexdigest(), 16))[:9]

    # Format the pincode in groups of digits for easier remembering if
    # we don't have a result yet.
    if rv is None:
        for group_size in 5, 4, 3:
            if len(num) % group_size == 0:
                rv = '-'.join(num[x:x + group_size].rjust(group_size, '0')
                              for x in range(0, len(num), group_size))
                break
        else:
            rv = num

    return rv, cookie_name
dataset/ETHPy150Open pallets/werkzeug/werkzeug/debug/__init__.py/get_pin_and_cookie_name/original