+Written by Peter Troeger <firstname.lastname@example.org>.
+A small Django authentication backend for OpenID, based on the openid2rp package.
+It is automatically installed together with openid2rp.
+In order to get the Django database magic right, you need to add 'openid2rp.django' to your
+INSTALLED_APPS list in setup.py. You also need to add 'openid2rp.django.auth.Backend' to the
+list of authentication backends. Example:
+AUTHENTICATION_BACKENDS = (
+The database is extended with one table for the OpenID identifier storage.
+Therefore, make sure that you call "python manage.py syncdb" ones
+after installing this package.
+In contrast to most other Django OpenID authentication packages, this one
+does not try to cover any view aspects. It also keeps the nature of openid2rp
+by assuming that you know how OpenID works.
+Since the Django authentication framework is not prepared for a multi-step auth scenario with several
+inputs and outputs, you need to call a preparation function ("preAuthenticate") from the module
+before you can use the Django authenticate() method. make sure that you use the correct keyword
+arguments in the authenticate() call.
+Session storage is based on a module-scope variable. I was to lazy to decode the openid2rp session dict
+for the database storing and lifetime checking. There is also no Nonce checking so far.
+The explicit modeling of each exceptional case hopefully allows you to realize an according
+reaction in your view rendering.
+from django.conf import settings
+from django.contrib.auth.models import User
+from openid2rp.django.models import UserOpenID
+from django.http import HttpResponse
+from django.db.models import Q
+from django.contrib.auth.models import AnonymousUser
+def storeOpenID(user, openid):
+ claim=UserOpenID(user=user, uri=openid)
+ return UserOpenID.objects.filter(user=user).values_list('uri', flat=True)
+def preAuthenticate(uri, answer_url,
+ sreg = (('nickname', 'email'), ()),
+ ax = ((openid2rp.AX.email, openid2rp.AX.first, openid2rp.AX.last), ())):
+ Initializes the OpenID authentication.
+ The input are the OpenID URI the user wants to be authorized with. You get
+ that from your login screen. The answer_url is the one the provider should call when
+ finished, and the sreg / ax parameters as with the original openid2rp.request_authentication() call.
+ In the view for the answer_url, you will call then "authenticate".
+ The output are two values: response and claim.
+ The first value is the HttpResponse object with the neccessary redirect to the providers
+ login site. You just return that from your view.
+ The second value is the (normalized) claim URI from the original URI.
+ You need that later in the authenticate call, so store it somewhere in the session.
+ If something goes wrong, one of the following errors is raised: IncorrectURI, IncorrectClaim
+ kind, claimedId = openid2rp.normalize_uri(uri)
+ raise IncorrectURI(str(e))
+ res = openid2rp.discover(claimedId)
+ services, url, op_local = res
+ session = openid2rp.associate(services, url)
+ redirect_url=openid2rp.request_authentication( services, url, session['assoc_handle'], answer_url, claimedId, op_local, sreg=sreg, ax=ax )
+ return response, claimedId
+ def get_user(self, user_id):
+ return User.objects.get(pk=user_id)
+ except User.DoesNotExist:
+ def authenticate(self, **credentials):
+ This finalizes the OpenID authentication. Input kwargs parameters:
+ - request: Django request object, which has all the GET parameters being given by the OpenID provider
+ - claim: Output from the preAuthenicate() call we asked you to store somewhere.
+ The result of this call is either:
+ - A User object with additional attributes.
+ - A AnonymousUser object with additional attributes, in case the OpenID authentication was
+ good, but no matching user could be found.
+ - One of the exceptions.
+ The additional attributes are:
+ - openid_email: The eMail address, or None.
+ - openid_claim: The real claimId string for this user. You might want to use that in the storeID() call.
+ - openid_sreg: A dictionary of received SREG values.
+ - openid_ax: A dictionary of received AX values.
+ If you get an AnonymousUser object as result, you need to assign the returned claim string first to some
+ existing Django user. This backend will not create the according User object for you,
+ since this is application-specific. You can use the AX / SREG data to pre-fill some registration
+ form. If you somehow came to a Django user object for the returned claim string, use the storeID() call.
+ Possible errors: MissingSession, AuthenticationError, IncompleteAnswer, MultipleClaimUsage
+ if not ("request" in credentials and "claim" in credentials):
+ handle = request.GET['openid.assoc_handle']
+ for session in sessions:
+ if session['assoc_handle'] == handle:
+ signed=openid2rp.authenticate(session, query)
+ raise AuthenticationError(str(e))
+ # provider-based auth returns claim id, OpenID not (if I got that right) - in this case we take the original value
+ if 'openid.claimed_id' in request.GET:
+ if 'claimed_id' not in signed:
+ raise IncompleteAnswer()
+ claimedId = request.GET['openid.claimed_id']
+ if 'identity' not in signed:
+ raise IncompleteAnswer()
+ # look up OpenID claim string in local database
+ # more than one user has this claimID, which is definitly wrong
+ raise MultipleClaimUsage()
+ # No user has this OpenID claim string assigned
+ # inactive users are handled by the later login() method, so we can return them here too
+ user.openid_claim = claimedId
+ user.openid_ax = openid2rp.get_ax(query, openid2rp.get_namespaces(query), signed)
+ user.openid_sreg = openid2rp.get_sreg(query, signed)
+ user.openid_email = openid2rp.get_email(query)