Parameterized Role-Based Access Control for Django
(Parameterized Role-Based Access Control)
About RBAC and PRBAC
Role-based access control (RBAC) is the standard method for access control in large systems. With RBAC, you grant privileges to roles. For example you might grant the privilege Reporting to the role Analyst. In most systems, you can nest roles as deeply as you want, and give users however many roles. A good example of this in practice is PostgreSQL roles and privileges.
The roles and privileges are whatever abstract concepts make sense for your system. It is up to application code to determine what actions to take based on the privileges granted. This can, of course, be implemented in terms of a lower-level permission system such as row-level or object-level access control lists (ACLs).
Parameterized role-based access control (PRBAC) adds parameters to roles and privileges. Now, for example, you might grant "Reporting(organization="Dimagi",area="Finance") to FinancialAnalyst(organization="Dimagi"). If you don’t use parameters, then it is just RBAC. If you use parameters with finite sets of choice, then it is exponentially more powerful. If you use parameters with infinitely many choices (such as strings or integers) then it is infinitely more powerful. A good example of limited parameterization is how particular privileges (SELECT, UPDATE, etc) in PostgreSQL may be parameterized by an object. In PRBAC this parameterization is pervasive.
To learn more about parameterized role-based access control as implemented in this library, please visit http://django-prbac.readthedocs.org/
Access Control for Django
- django.contrib.auth: This app, shipped with Django, provides unix-style access control (users, groups, permissions) with an extensible set of permissions that are implicitly parameterized by a content type. This is fundamentally different than role-based access control. It is only worth mentioning because it comes with Django and everyone is going to want to know “why did you reimplement the wheel?”. If django.contrib.auth is the wheel, then RBAC is the car and PRBAC is a transformer. I leave it as an exercise to the reader to attempt to implement PRBAC using django.contrib.auth :-)
- django-rbac: This project appears defunct and is not parameterized in any rate.
- django-role-permissions: This app implements a sort of RBAC where roles are statically defined in code.
- Others can be perused at https://www.djangopackages.com/grids/g/perms/. Many offer object-level permissions, which is as orthogonal to role-based access control as unix permissions. In fact, this is probably true of anything using the term “permissions”.
To install, use pip:
$ pip install django-prbac
Django-prbac is distributed under the MIT license. (See the LICENSE file for details)