Let exceptions bubble up and pass them on to render_failure so we can give users…

Let exceptions bubble up and pass them on to render_failure so we can give users helpful information when their login fails

django_openid_auth/auth.py

@@ -37,13 +37,13 @@ from openid.extensions import ax, sreg, pape
 
 from django_openid_auth import teams
 from django_openid_auth.models import UserOpenID
-
-
-class IdentityAlreadyClaimed(Exception):
-    pass
-
-class StrictUsernameViolation(Exception):
-    pass
+from django_openid_auth.exceptions import (
+    DjangoOpenIDException,
+    IdentityAlreadyClaimed,
+    DuplicateUsernameViolation,
+    MissingUsernameViolation,
+    MissingPhysicalMultiFactor,
+)
     
 class OpenIDBackend:
     """A django.contrib.auth backend that authenticates the user based on
@@ -74,10 +74,7 @@ class OpenIDBackend:
                 claimed_id__exact=openid_response.identity_url)
         except UserOpenID.DoesNotExist:
             if getattr(settings, 'OPENID_CREATE_USERS', False):
-                try:
-                    user = self.create_user_from_openid(openid_response)
-                except StrictUsernameViolation:
-                    return None
+                user = self.create_user_from_openid(openid_response)
         else:
             user = user_openid.user
 
@@ -92,7 +89,7 @@ class OpenIDBackend:
             pape_response = pape.Response.fromSuccessResponse(openid_response)
             if pape_response is None or \
                pape.AUTH_MULTI_FACTOR_PHYSICAL not in pape_response.auth_policies:
-                return None
+                raise MissingPhysicalMultiFactor()
 
         teams_response = teams.TeamsResponse.fromSuccessResponse(
             openid_response)
@@ -152,7 +149,7 @@ class OpenIDBackend:
         # get one back from the provider
         if getattr(settings, 'OPENID_STRICT_USERNAMES', False):
             if nickname is None or nickname == '':
-                raise StrictUsernameViolation("No username")
+                raise MissingUsernameViolation()
                 
         # If we don't have a nickname, and we're not being strict, use a default
         nickname = nickname or 'openiduser'
@@ -188,7 +185,7 @@ class OpenIDBackend:
 
         if getattr(settings, 'OPENID_STRICT_USERNAMES', False):
             if User.objects.filter(username__exact=nickname).count() > 0:
-                raise StrictUsernameViolation("Duplicate username: %s" % nickname)
+                raise DuplicateUsernameViolation("Duplicate username: %s" % nickname)
 
         # Pick a username for the user based on their nickname,
         # checking for conflicts.

django_openid_auth/exceptions.py

+# django-openid-auth -  OpenID integration for django.contrib.auth
+#
+# Copyright (C) 2008-2010 Canonical Ltd.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions
+# are met:
+#
+# * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#
+# * Redistributions in binary form must reproduce the above copyright
+# notice, this list of conditions and the following disclaimer in the
+# documentation and/or other materials provided with the distribution.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+# FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+# COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+# INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+# BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+# LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+# CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+# ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+# POSSIBILITY OF SUCH DAMAGE.
+
+"""Exception classes thrown by OpenID Authentication and Validation."""
+
+class DjangoOpenIDException(Exception):
+    pass
+
+class IdentityAlreadyClaimed(DjangoOpenIDException):
+
+    def __init__(self, message=None):
+        if message is None:
+            self.message = "Another user already exists for your selected OpenID"
+        else:
+            self.message = message
+
+class StrictUsernameViolation(DjangoOpenIDException):
+    pass
+    
+class DuplicateUsernameViolation(StrictUsernameViolation):
+
+    def __init__(self, message=None):
+        if message is None:
+            self.message = "Your desired username is already being used."
+        else:
+            self.message = message
+
+class MissingUsernameViolation(StrictUsernameViolation):
+
+    def __init__(self, message=None):
+        if message is None:
+            self.message = "No nickname given for your account."
+        else:
+            self.message = message
+
+class MissingPhysicalMultiFactor(DjangoOpenIDException):
+
+    def __init__(self, message=None):
+        if message is None:
+            self.message = "Login requires physical multi-factor authentication."
+        else:
+            self.message = message
+

django_openid_auth/views.py

@@ -55,6 +55,13 @@ from django_openid_auth.forms import OpenIDLoginForm
 from django_openid_auth.models import UserOpenID
 from django_openid_auth.signals import openid_login_complete
 from django_openid_auth.store import DjangoOpenIDStore
+from django_openid_auth.exceptions import (
+    DjangoOpenIDException,
+    IdentityAlreadyClaimed,
+    DuplicateUsernameViolation,
+    MissingUsernameViolation,
+    MissingPhysicalMultiFactor,
+)
 
 
 next_url_re = re.compile('^/[-\w/]+$')
@@ -118,10 +125,11 @@ def render_openid_request(request, openid_request, return_to, trust_root=None):
 
 
 def default_render_failure(request, message, status=403,
-                           template_name='openid/failure.html'):
+                           template_name='openid/failure.html',
+                           exception=None):
     """Render an error page to the user."""
     data = render_to_string(
-        template_name, dict(message=message),
+        template_name, dict(message=message, exception=exception),
         context_instance=RequestContext(request))
     return HttpResponse(data, status=status)
 
@@ -171,7 +179,8 @@ def login_begin(request, template_name='openid/login.html',
         openid_request = consumer.begin(openid_url)
     except DiscoveryFailure, exc:
         return render_failure(
-            request, "OpenID discovery error: %s" % (str(exc),), status=500)
+            request, "OpenID discovery error: %s" % (str(exc),), status=500,
+            exception=exc)
 
     # Request some user details.  If the provider advertises support
     # for attribute exchange, use that.
@@ -248,7 +257,11 @@ def login_complete(request, redirect_field_name=REDIRECT_FIELD_NAME,
             request, 'This is an OpenID relying party endpoint.')
 
     if openid_response.status == SUCCESS:
-        user = authenticate(openid_response=openid_response)
+        try:
+            user = authenticate(openid_response=openid_response)
+        except DjangoOpenIDException, e:
+            return render_failure(request, "Login Failed", exception=e)
+            
         if user is not None:
             if user.is_active:
                 auth_login(request, user)