AttributeError raised when session id is regenerated with Python 3

[Jun Omae]

Originally reported at ​trac:#13792.

Traceback (most recent call last):
  File "/usr/local/lib/python3.10/dist-packages/trac/web/api.py", line 662, in __getattr__
    value = self.callbacks[name](self)
  File "/usr/local/lib/python3.10/dist-packages/trac/web/main.py", line 180, in authenticate
    authname = authenticator.authenticate(req)
  File "/usr/local/lib/python3.10/dist-packages/acct_mgr/util.py", line 54, in wrap
    return func(self, *args, **kwds)
  File "/usr/local/lib/python3.10/dist-packages/acct_mgr/web_ui.py", line 488, in authenticate
    return super(LoginModule, self).authenticate(req)
  File "/usr/local/lib/python3.10/dist-packages/trac/web/auth.py", line 97, in authenticate
    authname = self._get_name_for_cookie(req,
  File "/usr/local/lib/python3.10/dist-packages/acct_mgr/web_ui.py", line 596, in _get_name_for_cookie
    cookie.value = hex_entropy()
AttributeError: can't set attribute 'value'

Using ​.set method seems to to be fixed instead of directly set .value property.

acct_mgr/web_ui.py

@@ -593 +593 @@
             if random.random() + self.cookie_refresh_pct / 100.0 > 1:
                 old_cookie = cookie.value
                 # Update auth cookie value
-                cookie.value = hex_entropy()
+                new_cookie = hex_entropy()
+                cookie.set('value', new_cookie, new_cookie)
                 self.log.debug("Changing session id for user %s to %s", name,
                                cookie.value)
 

Python 3

Python 3.11.10 (main, Sep  7 2024, 18:35:42) [GCC 9.4.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> from trac.web.api import Cookie
>>> cookies = Cookie('name1=value1; name2=value2')
>>> cookies
<Cookie: name1='value1' name2='value2'>
>>> cookies['name1']
<Morsel: name1=value1>
>>> cookies['name1'].value = '?'
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
AttributeError: property 'value' of 'Morsel' object has no setter
>>> cookies['name1'].value = 'vvv'
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
AttributeError: property 'value' of 'Morsel' object has no setter
>>> cookies['name1'].set('value', 'vvvv', 'vvvv')
>>> cookies['name1'].value
'vvvv'
>>>

Python 2.7

Python 2.7.18 (default, Jul  1 2022, 12:27:04)
[GCC 9.4.0] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> from trac.web.api import Cookie
>>> cookies = Cookie('name1=value1; name2=value2')
>>> cookies['name1']
<Morsel: name1='value1'>
>>> cookies['name1'].set('value', 'vvvv', 'vvvv')
>>> cookies['name1']
<Morsel: value='vvvv'>
>>> cookies
<Cookie: name1='vvvv' name2='value2'>
>>>

[Jun Omae]

In 18669:

TracAccountManager 0.6.1dev: fix AttributeError raised when session cookie is regenerated (closes #14361)