Can't use signed and marshalled cookies together.

• Key: MODPYTHON-200
• Type: Bug
• Status: Closed
• Resolution: Fixed
• Priority: Major
• Assignee: Graham Dumpleton
• Reporter: Graham Dumpleton
• Component/s: core
• Affects Version/s: 3.2.10
• Fix Version/s: 3.3.1

Description

As reported by Clodoaldo Pinto Neto on mailing list:

  http://www.modpython.org/pipermail/mod_python/2006-October/022427.html

one cannot use signed and marshalled cookies together.

For example, with publisher code example:



from mod_python import Cookie

def makecookies(req):
    c = Cookie.MarshalCookie('marshal', 'value', 'secret')
    d = Cookie.SignedCookie('signed', 'value', 'secret')
    Cookie.add_cookie(req, c)
    Cookie.add_cookie(req, d)
    return 'made\n' + str(req.headers_out)

def showcookies(req):
    cookies = Cookie.get_cookies(req, Cookie.MarshalCookie, secret='secret')
    s = 'There are %s cookies'% len(cookies)
    for c in cookies.values():
        s += '\n%s %s' % (str(c), type(c))
    return 'read\n' + repr(cookies) + '\n' + s + '\n' + str(req.headers_in)



if one access makecookies and then showcookies, you get:



Traceback (most recent call last):

  File "/System/Library/Frameworks/Python.framework/Versions/2.3/lib/python2.3/site-packages/mod_python/importer.py", line 1519, in HandlerDispatch
    default=default_handler, arg=req, silent=hlist.silent)

  File "/System/Library/Frameworks/Python.framework/Versions/2.3/lib/python2.3/site-packages/mod_python/importer.py", line 1224, in _process_target
    result = _execute_target(config, req, object, arg)

  File "/System/Library/Frameworks/Python.framework/Versions/2.3/lib/python2.3/site-packages/mod_python/importer.py", line 1123, in _execute_target
    result = object(arg)

  File "/System/Library/Frameworks/Python.framework/Versions/2.3/lib/python2.3/site-packages/mod_python/publisher.py", line 213, in handler
    published = publish_object(req, object)

  File "/System/Library/Frameworks/Python.framework/Versions/2.3/lib/python2.3/site-packages/mod_python/publisher.py", line 425, in publish_object
    return publish_object(req,util.apply_fs_data(object, req.form, req=req))

  File "/System/Library/Frameworks/Python.framework/Versions/2.3/lib/python2.3/site-packages/mod_python/util.py", line 546, in apply_fs_data
    return object(**args)

  File "/Users/grahamd/public_html/cookies/index.py", line 11, in showcookies
    cookies = Cookie.get_cookies(req, Cookie.MarshalCookie, secret='secret')

  File "/System/Library/Frameworks/Python.framework/Versions/2.3/lib/python2.3/site-packages/mod_python/Cookie.py", line 352, in get_cookies
    return Class.parse(cookies, **kw)

  File "/System/Library/Frameworks/Python.framework/Versions/2.3/lib/python2.3/site-packages/mod_python/Cookie.py", line 254, in parse
    c.unmarshal(secret)

  File "/System/Library/Frameworks/Python.framework/Versions/2.3/lib/python2.3/site-packages/mod_python/Cookie.py", line 282, in unmarshal
    self.value = marshal.loads(base64.decodestring(self.value))

  File "/System/Library/Frameworks/Python.framework/Versions/2.3/lib/python2.3/base64.py", line 44, in decodestring
    return binascii.a2b_base64(s)

Error: Incorrect padding



The problem is that Cookie.get_cookies() makes assumption that all cookies being sent by browser will be of the same derived type, or are a basic cookie. If mixing derived types and they are not compatible as far as unpacking goes, the code will fail.

For starters, there should be a new function called Cookie.get_cookie() where you name the cookie and it only tries to decode that one cookie. This new method should also be used in the Session class instead of using Cookie.get_cookies().