Changes between Version 11 and Version 12 of MultipleAuthBackends

Timestamp:

Mar 15, 2006, 12:41:06 PM (20 years ago)

Author:

jkocherhans

Comment:

clarifications about differences, and added back credential plugins and AuthUtil

MultipleAuthBackends

@@ -7 +7 @@
 The default authentication mechanism for Django will still check a username/password against django.contrib.auth.models.User
 
-The path to the default authentication backend can be set in settings.py via the AUTHENTICATION_BACKEND variable. This variable is used by {{{django.contrib.auth.middleware.AuthenticationMiddleware}}} to set the request.user attribute.
-
-
-== Backends ==
-
-Authentication backends are pretty simple. They just need to implement 2 
-methods, {{{authenticate}}} and {{{get_user}}}.
-
-=== backend.authenticate(self, request) ===
-{{{backend.authenticate}}} takes a request object, and if it finds valid credentials in the request, it returns a user object. If not, it returns None.
-
-Note that when you write an authentication backend, you can grab a token, or whatever else you want out of the request, and check against ldap, another sql database, or pretty much anything accessible via python.
-
-The user object will generally be an instance of {{{django.contrib.auth.models.User}}}, but really, it could be anything. You will need to at least fake the interface for {{{django.contrib.auth.models.User}}} if you want to use the admin system however. Your backend can create and save an instance of {{{django.contrib.auth.models.User}}} when a user logs in for the first time. You could also add them to a default set of groups at that time.
-
-=== backend.get_user(self, user_id) ===
-
-{{{backend.get_user}}} simply takes a user id and returns the user that matches that id.
+The path to the default authentication backend can be set in settings.py via the AUTHENTICATION_BACKEND variable. This backend is used to set the request.user attribute automatically. There is also a backend that is just a front for using multiple backends, but we'll get to that later.
 
 
 == Authenticating ==
 
-Here's a very simple code sample that authenticates a user:
+Here's a code sample that authenticates a user. This would be used to process login forms. Like before, you'd check {{{request.user.is_anonymous()}}} if you want to test if user is logged in.
 
 {{{
 #!python
 
-from django.conf import settings
-from django.contrib.auth.backends import load_backend
+from django.contrib.auth import AuthUtil
 
-def myview(self, request):
-    backend = load_backend(settings.AUTHENTICATION_BACKEND)
-    user = backend.authenticate(request)
+def login(self, request):
+    authutil = AuthUtil()
+    user = authutil.authenticate(request)
     if user is None:
         # do whatever for invalid logins
     else:
-        # the user is valid, persist their id in a session var or whatever.
-        # do whatever else this view is suppose to do.
+        # the user is valid, persist their id (username, email, token, etc.) in a session var or whatever.
+        # do whatever else this view is supposed to do.
 }}}
 
@@ -51 +33 @@
 For extra points, there should be ways of tying this all in with WSGI ;)
 
+
+== Credentials ==
+
+Credentials are extracted from the request by plugins. These plugins are just functions that take the request as their only argument and return a dict or string containing the credentials. You can have multiple ordered credential plugins by changing {{{CREDENTIAL_PLUGINS}}} in your settings file.
+
+{{{
+#!python
+
+CREDENTIAL_PLUGINS = (
+    'django.contrib.auth.credentials.username_password_form',
+    'django.contrib.auth.credentials.token',
+)
+
+}}}
+
+AuthUtil will use the first plugin and hand the credentials to {{{AUTHENTICATION_BACKEND}}}. If {{{AUTHENTICATION_BACKEND}}} returns None for the first set of credentials, the next plugin will be tried, and so on.
+
+{{{CREDENTIAL_PLUGINS}}} defaults to {{{('django.contrib.auth.credentials.username_password_form',)}}}
+
+
 == Using Multiple Backends ==
 
-To use multiple authentication backends, you just use another backend called {{{django.contrib.auth.backends.MultiBackend}}} It is configured with a list of backends you'd like to use, and just calls each backend in order.
+To use multiple authentication backends, set AUTHENTICATION_BACKEND to {{{django.contrib.auth.backends. MultiAuthBackend}}} in your settings file.You must also set AUTHENTICATION_BACKEND to a tuple of the backends you wish to use, in order.
+
+For example:
+
+{{{
+#!python
+
+AUTHENTICATION_BACKEND = 'django.contrib.auth.backends.MultiAuthBackend'
+
+MULTIAUTH_BACKENDS = (
+    'django.contrib.auth.backends.LDAPBackend',
+    'django.contrib.auth.backends.ModelBackend',
+)
+}}}
+
+When you call {{{authenticate}}} or {{{get_user}}} on {{{MultiAuthBackend}}}, it will in turn call the same method on each backend in {{{MULTIAUTH_BACKENDS}}} in order.
+
+
+== Writing Backends ==
+
+Authentication backends are pretty simple. They just need to implement 2 
+methods, {{{authenticate}}} and {{{get_user}}}.
+
+=== backend.authenticate(self, credentials) ===
+If the credentials match a user in this backend it returns a user object. If not, it returns None. Keep in mind that credentials could be a dict, a string, pretty much anything. You'll have to make sure that {{{authenticate}}} does the appropriate checking and returns None for credentials that it can't handle.
+
+The user object will generally be an instance of {{{django.contrib.auth.models.User}}}, but really, it could be anything. You will need to at least fake the interface for {{{django.contrib.auth.models.User}}} if you want to use the admin system however. Your backend can create and save an instance of {{{django.contrib.auth.models.User}}} when a user logs in for the first time. You could also add them to a default set of groups at that time.
+
+=== backend.get_user(self, user_id) ===
+
+{{{backend.get_user}}} simply takes a user id and returns the user that matches that id. The user id is not neccessarily numeric, and in most cases it won't be. It could be a username, an email address, whatever. The important part is that it uniquely identifies a user.
+
+
+