OpenIDConnect backend

Use social-auth to authenticate with OpenIDConnect.
Add API to manage sso groups.

Pipfile

@@ -51,6 +51,8 @@ flower = "*"
 bleach = "*"
 zxing-cpp = {version = "*", platform_machine = "== 'x86_64'"}
 django-multiselectfield = "*"
+social-auth-core = {version = "*", extras = ["openidconnect"]}
+social-auth-app-django = "*"
 
 [dev-packages]
 # Linting

src/documents/templates/registration/login.html

@@ -51,20 +51,26 @@
         <div class="alert alert-danger" role="alert">
           {% translate "Share link has expired." %}
         </div>
-			{% endif %}
-			{% translate "Username" as i18n_username %}
-			{% translate "Password" as i18n_password %}
-      <div class="form-floating">
-        <input type="text" name="username" id="inputUsername" placeholder="{{ i18n_username }}" class="form-control" autocorrect="off" autocapitalize="none" required autofocus>
-        <label for="inputUsername">{{ i18n_username }}</label>
-      </div>
-      <div class="form-floating">
-        <input type="password" name="password" id="inputPassword" placeholder="{{ i18n_password }}" class="form-control" required>
-			  <label for="inputPassword">{{ i18n_password }}</label>
-      </div>
-      <div class="d-grid mt-3">
-        <button class="btn btn-lg btn-primary" type="submit">{% translate "Sign in" %}</button>
-      </div>
+	  {% endif %}
+	  {% if not settings.SOCIAL_AUTH_DISABLE_NORMAL_AUTH %}
+		{% translate "Username" as i18n_username %}
+		{% translate "Password" as i18n_password %}
+		<div class="form-floating">
+			<input type="text" name="username" id="inputUsername" placeholder="{{ i18n_username }}" class="form-control" autocorrect="off" autocapitalize="none" required autofocus>
+			<label for="inputUsername">{{ i18n_username }}</label>
+		</div>
+		<div class="form-floating">
+			<input type="password" name="password" id="inputPassword" placeholder="{{ i18n_password }}" class="form-control" required>
+				<label for="inputPassword">{{ i18n_password }}</label>
+		</div>
+		<div class="d-grid mt-3">
+			<button class="btn btn-lg btn-primary" type="submit">{% translate "Sign in" %}</button>
+		</div>
+	  {% endif %}
+	  {% if settings.SOCIAL_AUTH_OIDC_ENABLE %}
+		<a class="btn btn-lg btn-primary btn-block" href="{% url "social:begin" "oidc" %}">{{ settings.SOCIAL_AUTH_OIDC_NAME }}</a>
+	  {% endif %}
+	  
 		</form>
 	</body>
 </html>

src/paperless/admin.py

@@ -0,0 +1,5 @@
+from django.contrib import admin
+
+from paperless.models import SSOGroup
+
+admin.site.register(SSOGroup)

src/paperless/context_processors.py

@@ -0,0 +1,5 @@
+from django.conf import settings as django_settings
+
+
+def settings(request):
+    return {"settings": django_settings}

src/paperless/migrations/0001_initial.py

@@ -0,0 +1,44 @@
+# Generated by Django 4.1.10 on 2023-07-09 13:26
+
+import django.db.models.deletion
+from django.db import migrations
+from django.db import models
+
+
+class Migration(migrations.Migration):
+    initial = True
+
+    dependencies = [
+        ("auth", "0012_alter_user_first_name_max_length"),
+    ]
+
+    operations = [
+        migrations.CreateModel(
+            name="SSOGroup",
+            fields=[
+                (
+                    "id",
+                    models.AutoField(
+                        auto_created=True,
+                        primary_key=True,
+                        serialize=False,
+                        verbose_name="ID",
+                    ),
+                ),
+                ("name", models.CharField(max_length=256, unique=True)),
+                (
+                    "group",
+                    models.ForeignKey(
+                        on_delete=django.db.models.deletion.CASCADE,
+                        related_name="sso_groups",
+                        to="auth.group",
+                    ),
+                ),
+            ],
+            options={
+                "verbose_name": "SSO group",
+                "verbose_name_plural": "SSO groups",
+                "ordering": ("name",),
+            },
+        ),
+    ]

src/paperless/models.py

@@ -0,0 +1,21 @@
+from django.contrib.auth.models import Group
+from django.db import models
+from django.utils.translation import gettext_lazy as _
+
+
+class SSOGroup(models.Model):
+    group = models.ForeignKey(
+        Group,
+        related_name="sso_groups",
+        on_delete=models.CASCADE,
+        null=False,
+    )
+    name = models.CharField(max_length=256, blank=False, null=False, unique=True)
+
+    class Meta:
+        ordering = ("name",)
+        verbose_name = _("SSO group")
+        verbose_name_plural = _("SSO groups")
+
+    def __str__(self):
+        return self.name

src/paperless/serialisers.py

@@ -3,6 +3,8 @@ from django.contrib.auth.models import Permission
 from django.contrib.auth.models import User
 from rest_framework import serializers
 
+from paperless.models import SSOGroup
+
 
 class ObfuscatedUserPasswordField(serializers.Field):
     """
@@ -89,6 +91,11 @@ class GroupSerializer(serializers.ModelSerializer):
         queryset=Permission.objects.all(),
         slug_field="codename",
     )
+    sso_groups = serializers.PrimaryKeyRelatedField(
+        many=True,
+        queryset=SSOGroup.objects.all(),
+        required=False,
+    )
 
     class Meta:
         model = Group
@@ -96,4 +103,14 @@ class GroupSerializer(serializers.ModelSerializer):
             "id",
             "name",
             "permissions",
+            "sso_groups",
+        )
+
+
+class SSOGroupSerializer(serializers.ModelSerializer):
+    class Meta:
+        model = SSOGroup
+        fields = (
+            "name",
+            "group",
         )

src/paperless/settings.py

@@ -287,6 +287,7 @@ INSTALLED_APPS = [
     "django_filters",
     "django_celery_results",
     "guardian",
+    "social_django",
     *env_apps,
 ]
 
@@ -357,6 +358,8 @@ TEMPLATES = [
                 "django.template.context_processors.request",
                 "django.contrib.auth.context_processors.auth",
                 "django.contrib.messages.context_processors.messages",
+                "paperless.context_processors.settings",
+                "social_django.context_processors.backends",
             ],
         },
     },
@@ -383,8 +386,37 @@ AUTHENTICATION_BACKENDS = [
     "django.contrib.auth.backends.ModelBackend",
 ]
 
+SOCIAL_AUTH_DISABLE_NORMAL_AUTH = __get_boolean("PAPERLESS_SSO_DISABLE_NORMAL_AUTH")
+
+# Only support OIDC, but it should be easy to enable more backends
+if __get_boolean("PAPERLESS_SSO_OIDC_ENABLE"):
+    SOCIAL_AUTH_OIDC_ENABLE = True
+    AUTHENTICATION_BACKENDS.append(
+        "social_core.backends.open_id_connect.OpenIdConnectAuth",
+    )
+    SOCIAL_AUTH_OIDC_KEY = os.environ.get("PAPERLESS_SSO_OIDC_KEY")
+    SOCIAL_AUTH_OIDC_OIDC_ENDPOINT = os.environ.get("PAPERLESS_SSO_OIDC_ENDPOINT")
+    SOCIAL_AUTH_OIDC_SECRET = os.environ.get("PAPERLESS_SSO_OIDC_SECRET")
+    SOCIAL_AUTH_OIDC_NAME = os.environ.get("PAPERLESS_SSO_OIDC_NAME", "OpenID Connect")
+
+LOGIN_REDIRECT_URL = BASE_URL
+
 AUTO_LOGIN_USERNAME = os.getenv("PAPERLESS_AUTO_LOGIN_USERNAME")
 
+SOCIAL_AUTH_PIPELINE = (
+    "social_core.pipeline.social_auth.social_details",
+    "social_core.pipeline.social_auth.social_uid",
+    "social_core.pipeline.social_auth.auth_allowed",
+    "social_core.pipeline.social_auth.social_user",
+    "social_core.pipeline.user.get_username",
+    "social_core.pipeline.user.create_user",
+    "social_core.pipeline.social_auth.associate_user",
+    "social_core.pipeline.social_auth.load_extra_data",
+    "social_core.pipeline.user.user_details",
+    "social_core.pipeline.social_auth.load_extra_data",
+    "paperless.social_auth.update_groups",
+)
+
 if AUTO_LOGIN_USERNAME:
     _index = MIDDLEWARE.index("django.contrib.auth.middleware.AuthenticationMiddleware")
     # This overrides everything the auth middleware is doing but still allows

src/paperless/social_auth.py

@@ -0,0 +1,25 @@
+from paperless.models import SSOGroup
+
+
+def update_groups(response, user, *args, **kwargs):
+    # This works at least for openidconnect, if you want to implement new SSO
+    # you need to check that groups are strings in the list "groups"
+
+    # Search all existing groups associated with sso groups
+    sso_groups = set()
+    for group in response.get("groups", []):
+        for g in SSOGroup.objects.filter(name__exact=group):
+            sso_groups.add(g.group)
+    # Extract current sso groups currently connected to the user
+    actual_sso_groups = set()
+    for group in user.groups.filter(sso_groups__isnull=False):
+        if group.sso_groups.count() != 0:
+            for sso_group in group.sso_groups.all():
+                actual_sso_groups.add(sso_group.group)
+    # Add missing groups
+    for g in sso_groups - actual_sso_groups:
+        g.user_set.add(user)
+    # Remove groups which are connected to a sso group, but not connected
+    # anymore
+    for g in actual_sso_groups - sso_groups:
+        g.user_set.remove(user)

src/paperless/urls.py

@@ -35,6 +35,7 @@ from documents.views import UnifiedSearchViewSet
 from paperless.consumers import StatusConsumer
 from paperless.views import FaviconView
 from paperless.views import GroupViewSet
+from paperless.views import SSOGroupViewSet
 from paperless.views import UserViewSet
 from paperless_mail.views import MailAccountTestView
 from paperless_mail.views import MailAccountViewSet
@@ -55,6 +56,7 @@ api_router.register(r"mail_accounts", MailAccountViewSet)
 api_router.register(r"mail_rules", MailRuleViewSet)
 api_router.register(r"share_links", ShareLinkViewSet)
 api_router.register(r"consumption_templates", ConsumptionTemplateViewSet)
+api_router.register(r"sso_groups", SSOGroupViewSet)
 
 
 urlpatterns = [
@@ -167,6 +169,7 @@ urlpatterns = [
     # TODO: with localization, this is even worse! :/
     # login, logout
     path("accounts/", include("django.contrib.auth.urls")),
+    path("", include("social_django.urls", namespace="social")),
     # Root of the Frontend
     re_path(r".*", login_required(IndexView.as_view()), name="base"),
 ]

src/paperless/views.py

@@ -16,7 +16,9 @@ from rest_framework.viewsets import ModelViewSet
 from documents.permissions import PaperlessObjectPermissions
 from paperless.filters import GroupFilterSet
 from paperless.filters import UserFilterSet
+from paperless.models import SSOGroup
 from paperless.serialisers import GroupSerializer
+from paperless.serialisers import SSOGroupSerializer
 from paperless.serialisers import UserSerializer
 
 
@@ -106,3 +108,9 @@ class GroupViewSet(ModelViewSet):
     filter_backends = (DjangoFilterBackend, OrderingFilter)
     filterset_class = GroupFilterSet
     ordering_fields = ("name",)
+
+
+class SSOGroupViewSet(ModelViewSet):
+    model = SSOGroup
+    queryset = SSOGroup.objects
+    serializer_class = SSOGroupSerializer