=============================
User authentication in Django
=============================

.. toctree::
   :hidden:

   default
   passwords
   customizing

.. module:: django.contrib.auth
   :synopsis: Django's authentication framework.

Django comes with a user authentication system. It handles user accounts,
groups, permissions and cookie-based user sessions. This section of the
documentation explains how the default implementation works out of the box, as
well as how to :doc:`extend and customize </topics/auth/customizing>` it to
suit your project's needs.

Overview
========

The Django authentication system handles both authentication and authorization.
Briefly, authentication verifies a user is who they claim to be, and
authorization determines what an authenticated user is allowed to do. Here the
term authentication is used to refer to both tasks.

The auth system consists of:

* Users
* Permissions: Binary (yes/no) flags designating whether a user may perform
  a certain task.
* Groups: A generic way of applying labels and permissions to more than one
  user.
* A configurable password hashing system
* Forms and view tools for logging in users, or restricting content
* A pluggable backend system

The authentication system in Django aims to be very generic and doesn't provide
some features commonly found in web authentication systems. Solutions for some
of these common problems have been implemented in third-party packages:

* Password strength checking
* Throttling of login attempts
* Authentication against third-parties (OAuth, for example)

Installation
============

Authentication support is bundled as a Django contrib module in
``django.contrib.auth``. By default, the required configuration is already
included in the :file:`settings.py` generated by :djadmin:`django-admin
startproject <startproject>`, these consist of two items listed in your
:setting:`INSTALLED_APPS` setting:

1. ``'django.contrib.auth'`` contains the core of the authentication framework,
   and its default models.
2. ``'django.contrib.contenttypes'`` is the Django :doc:`content type system
   </ref/contrib/contenttypes>`, which allows permissions to be associated with
   models you create.

and these items in your :setting:`MIDDLEWARE_CLASSES` setting:

1. :class:`~django.contrib.sessions.middleware.SessionMiddleware` manages
   :doc:`sessions </topics/http/sessions>` across requests.
2. :class:`~django.contrib.auth.middleware.AuthenticationMiddleware` associates
   users with requests using sessions.
3. :class:`~django.contrib.auth.middleware.SessionAuthenticationMiddleware`
   logs users out of their other sessions after a password change.

With these settings in place, running the command ``manage.py migrate`` creates
the necessary database tables for auth related models and permissions for any
models defined in your installed apps.

Usage
=====

:doc:`Using Django's default implementation <default>`

* :ref:`Working with User objects <user-objects>`
* :ref:`Permissions and authorization <topic-authorization>`
* :ref:`Authentication in web requests <auth-web-requests>`
* :ref:`Managing users in the admin <auth-admin>`

:doc:`API reference for the default implementation </ref/contrib/auth>`

:doc:`Customizing Users and authentication <customizing>`

:doc:`Password management in Django <passwords>`
