Fixed #689 -- Added a middleware and authentication backend to contrib.auth for supporting external authentication solutions. Thanks to all who contributed to this patch, including Ian Holsman, garthk, Koen Biermans, Marc Fargas, ekarulf, and Ramiro Morales.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@10063 bcc190cf-cafb-0310-a4f2-bffc1f526a37

docs/howto/auth-remote-user.txt

@@ -0,0 +1,100 @@
+.. _howto-auth-remote-user:
+
+====================================
+Authentication using ``REMOTE_USER``
+====================================
+
+This document describes how to make use of external authentication sources
+(where the Web server sets the ``REMOTE_USER`` environment variable) in your
+Django applications.  This type of authentication solution is typically seen on
+intranet sites, with single sign-on solutions such as IIS and Integrated
+Windows Authentication or Apache and `mod_authnz_ldap`_, `CAS`_, `Cosign`_,
+`WebAuth`_, `mod_auth_sspi`_, etc.
+
+.. _mod_authnz_ldap: http://httpd.apache.org/docs/2.2/mod/mod_authnz_ldap.html
+.. _CAS: http://www.ja-sig.org/products/cas/
+.. _Cosign: http://weblogin.org
+.. _WebAuth: http://www.stanford.edu/services/webauth/
+.. _mod_auth_sspi: http://sourceforge.net/projects/mod-auth-sspi
+
+When the Web server takes care of authentication it typically sets the
+``REMOTE_USER`` environment variable for use in the underlying application.  In
+Django, ``REMOTE_USER`` is made available in the :attr:`request.META
+<django.http.HttpRequest.META>` attribute.  Django can be configured to make
+use of the ``REMOTE_USER`` value using the ``RemoteUserMiddleware`` and
+``RemoteUserBackend`` classes found in :mod:`django.contirb.auth`.
+
+Configuration
+=============
+
+First, you must add the
+:class:`django.contrib.auth.middleware.RemoteUserMiddleware` to the
+:setting:`MIDDLEWARE_CLASSES` setting **after** the
+:class:`django.contrib.auth.middleware.AuthenticationMiddleware`::
+
+    MIDDLEWARE_CLASSES = (
+        ...
+        'django.contrib.auth.middleware.AuthenticationMiddleware',
+        'django.contrib.auth.middleware.RemoteUserMiddleware',
+        ...
+        )
+
+Next, you must replace the :class:`~django.contrib.auth.backends.ModelBackend`
+with ``RemoteUserBackend`` in the :setting:`AUTHENTICATION_BACKENDS` setting::
+
+    AUTHENTICATION_BACKENDS = (
+        'django.contrib.auth.backends.RemoteUserBackend',
+    )
+
+With this setup, ``RemoteUserMiddleware`` will detect the username in
+``request.META['REMOTE_USER']`` and will authenticate and auto-login that user
+using the ``RemoteUserBackend``.
+
+.. note::
+   Since the ``RemoteUserBackend`` inherits from ``ModelBackend``, you will
+   still have all of the same permissions checking that is implemented in
+   ``ModelBackend``.
+
+If your authentication mechanism uses a custom HTTP header and not
+``REMOTE_USER``, you can subclass ``RemoteUserMiddleware`` and set the
+``header`` attribute to the desired ``request.META`` key.  For example::
+
+    from django.contrib.auth.middleware import RemoteUserMiddleware
+
+    class CustomHeaderMiddleware(RemoteUserMiddleware):
+        header = 'HTTP_AUTHUSER'
+
+
+``RemoteUserBackend``
+=====================
+
+.. class:: django.contrib.backends.RemoteUserBackend
+
+If you need more control, you can create your own authentication backend
+that inherits from ``RemoteUserBackend`` and overrides certain parts:
+
+Attributes
+~~~~~~~~~~
+
+.. attribute:: RemoteUserBackend.create_unknown_user
+
+    ``True`` or ``False``.  Determines whether or not a
+    :class:`~django.contrib.auth.models.User` object is created if not already
+    in the database.  Defaults to ``True``.
+
+Methods
+~~~~~~~
+
+.. method:: RemoteUserBackend.clean_username(username)
+
+   Performs any cleaning on the ``username`` (e.g. stripping LDAP DN
+   information) prior to using it to get or create a
+   :class:`~django.contrib.auth.models.User` object.  Returns the cleaned
+   username.
+
+.. method:: RemoteUserBackend.configure_user(user)
+
+   Configures a newly created user.  This method is called immediately after a
+   new user is created, and can be used to perform custom setup actions, such
+   as setting the user's groups based on attributes in an LDAP directory.
+   Returns the user object.

docs/howto/index.txt

@@ -10,8 +10,9 @@ you quickly accomplish common tasks.
 
 .. toctree::
    :maxdepth: 1
-   
+
    apache-auth
+   auth-remote-user
    custom-management-commands
    custom-model-fields
    custom-template-tags
@@ -30,5 +31,5 @@ you quickly accomplish common tasks.
     The `Django community aggregator`_, where we aggregate content from the
     global Django community. Many writers in the aggregator write this sort of
     how-to material.
-    
-    .. _django community aggregator: http://www.djangoproject.com/community/
+
+    .. _django community aggregator: http://www.djangoproject.com/community/