Remove Trac permissions using a blacklist and/or whitelist


This plugin allows you to remove Trac permissions using a blacklist and/or a whitelist.

This hack was born to be able to archive projects without touching the Trac database, the idea is to use the filter to disable all permissions that allow users to modify it without changing their permissions on the database and be able to restore the project to the original state simply disabling the filter.

To filter permissions as desired the plugin has to be the first one on the permission_policy list and it works by checking the permissions against the blacklist and the whitelist in that order. If a permission is in both lists it is blacklisted.

The process is as follows:

  1. If the blacklist is available and the permission being considered is on the list the check_permission function returns False and the permission evaluation stops.
  2. If the whitelist is available and the permission we are checking is not on the list the check_permission function returns False and the permission evaluation stops.
  3. If the evaluation gets here the permission is ignored by the plugin and the next permission policy is checked.

If the boolean option adminmeta is True, then the filters are ignored for users with the TRAC_ADMIN permission.

Bugs/Feature Requests

Existing bugs and feature requests for TracPermissionFilterPlugin are here.

If you have any issues, create a new ticket.


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Download the zipped source from here.


You can check out TracPermissionFilterPlugin from here using Subversion, or browse the source with Trac.


General instructions on installing Trac plugins can be found on the TracPlugins page.


After enabling the plugin in your trac.ini file:

tracpermissionfilter.* = enabled

Add a section with the list of permissions to allow:


or a list of permissions to deny:

blacklist = BROWSER_VIEW

The use of the two lists (black and white) makes sense when using inheritance to avoid repeating long lists. For example, we can have a long whitelist and reduce it only in one project using the blacklist.

The plugin has also an additional boolean option called adminmeta. If this option is set to True (the default), then the filters don't affect the users with TRAC_ADMIN permission:

adminmeta = true

If the variable is set to False filtering has odd effects on users with the TRAC_ADMIN permission because we reject based on action name and TRAC_ADMIN is a meta permission that usually is not checked directly.

Lastly, remember to put the filter the first on your project permission_policies:

permission_policies = PermissionFilter, DefaultPermissionPolicy

Recent Changes

13912 by rjollos on 2014-05-07 23:26:21
Fixed indentation and replaced tabs with spaces. Fixes #11737.
12139 by rjollos on 2012-10-10 03:54:13
Fixed incorrect source code encoding (
10850 by sto on 2011-10-28 18:08:29
Changed TRAC_ADMIN handig and renamed config option


Author: sto
Maintainer: Sergio Talens-Oliag

Last modified 6 months ago Last modified on Nov 9, 2015, 2:40:52 PM