sources/oauth: directly call AuthorizedServiceBackend instead of authenticate()

passbook/sources/oauth/auth.py

@@ -1,24 +1,23 @@
 """passbook oauth_client Authorization backend"""
-
 from django.contrib.auth.backends import ModelBackend
 from django.db.models import Q
+from django.http import HttpRequest
 
+from passbook.core.models import User
 from passbook.sources.oauth.models import OAuthSource, UserOAuthSourceConnection
 
 
 class AuthorizedServiceBackend(ModelBackend):
     "Authentication backend for users registered with remote OAuth provider."
 
-    def authenticate(self, request, source=None, identifier=None):
+    def authenticate(
+        self, request: HttpRequest, source: OAuthSource, identifier: str
+    ) -> User:
         "Fetch user for a given source by id."
         source_q = Q(source__name=source)
         if isinstance(source, OAuthSource):
             source_q = Q(source=source)
-        try:
-            access = UserOAuthSourceConnection.objects.filter(
-                source_q, identifier=identifier
-            ).select_related("user")[0]
-        except IndexError:
-            return None
-        else:
-            return access.user
+        access = UserOAuthSourceConnection.objects.filter(
+            source_q, identifier=identifier
+        ).select_related("user")[0]
+        return access.user

passbook/sources/oauth/settings.py

@@ -1,9 +1,5 @@
 """Oauth2 Client Settings"""
 
-AUTHENTICATION_BACKENDS = [
-    "passbook.sources.oauth.backends.AuthorizedServiceBackend",
-]
-
 PASSBOOK_SOURCES_OAUTH_TYPES = [
     "passbook.sources.oauth.types.discord",
     "passbook.sources.oauth.types.facebook",

passbook/sources/oauth/views/core.py

@@ -3,7 +3,6 @@ from typing import Any, Callable, Dict, Optional
 
 from django.conf import settings
 from django.contrib import messages
-from django.contrib.auth import authenticate
 from django.contrib.auth.mixins import LoginRequiredMixin
 from django.http import Http404, HttpRequest, HttpResponse
 from django.shortcuts import get_object_or_404, redirect, render
@@ -22,6 +21,7 @@ from passbook.flows.planner import (
 )
 from passbook.flows.views import SESSION_KEY_PLAN
 from passbook.lib.utils.urls import redirect_with_qs
+from passbook.sources.oauth.auth import AuthorizedServiceBackend
 from passbook.sources.oauth.clients import BaseOAuthClient, get_client
 from passbook.sources.oauth.models import OAuthSource, UserOAuthSourceConnection
 from passbook.stages.password.stage import PLAN_CONTEXT_AUTHENTICATION_BACKEND
@@ -134,7 +134,7 @@ class OAuthCallback(OAuthClientMixin, View):
                     identifier=identifier,
                     access_token=token.get("access_token"),
                 )
-            user = authenticate(
+            user = AuthorizedServiceBackend().authenticate(
                 source=self.source, identifier=identifier, request=request
             )
             if user is None:
@@ -181,7 +181,8 @@ class OAuthCallback(OAuthClientMixin, View):
             self.request,
             {
                 PLAN_CONTEXT_PENDING_USER: user,
-                PLAN_CONTEXT_AUTHENTICATION_BACKEND: user.backend,
+                # Since we authenticate the user by their token, they have no backend set
+                PLAN_CONTEXT_AUTHENTICATION_BACKEND: "django.contrib.auth.backends.ModelBackend",
                 PLAN_CONTEXT_SSO: True,
             },
         )
@@ -206,7 +207,7 @@ class OAuthCallback(OAuthClientMixin, View):
                 % {"source": self.source.name}
             ),
         )
-        user = authenticate(
+        user = AuthorizedServiceBackend().authenticate(
             source=access.source, identifier=access.identifier, request=self.request
         )
         return self.handle_login_flow(source.authentication_flow, user)
@@ -249,7 +250,7 @@ class OAuthCallback(OAuthClientMixin, View):
                 )
             )
         # User was not authenticated, new user has been created
-        user = authenticate(
+        user = AuthorizedServiceBackend().authenticate(
             source=access.source, identifier=access.identifier, request=self.request
         )
         messages.success(