✨(backend) integrate ResourceServerAuthentication on the external api

Upgrade django-lasuite to v0.0.19 to benefit from the latest resource server
authentication backend. Thanks @qbey for your work. For my needs, @qbey
refactored the class in #46 on django-lasuite.

Integrate ResourceServerAuthentication in the relevant viewset. The integration
is straightforward since most heavy lifting was done in the external-api viewset
when introducing the service account.

Slightly modify the existing service account authentication backend to defer to
ResourceServerAuthentication if a token is not recognized.

Override user provisioning behavior in ResourceServerBackend: now, a user is
automatically created if missing, based on the 'sub' claim (email is not yet
present in the introspection response). Note: shared/common implementation
currently only retrieves users, failing if the user does not exist.

.github/workflows/meet.yml

@@ -183,6 +183,10 @@ jobs:
       AWS_S3_ENDPOINT_URL: http://localhost:9000
       AWS_S3_ACCESS_KEY_ID: meet
       AWS_S3_SECRET_ACCESS_KEY: password
+      OIDC_RS_CLIENT_ID: meet
+      OIDC_RS_CLIENT_SECRET: ThisIsAnExampleKeyForDevPurposeOnly
+      OIDC_OP_INTROSPECTION_ENDPOINT: https://oidc.example.com/introspect
+      OIDC_OP_URL: https://oidc.example.com
 
     steps:
       - name: Checkout repository

env.d/development/common.dist

@@ -32,6 +32,8 @@ OIDC_OP_JWKS_ENDPOINT=http://nginx:8083/realms/meet/protocol/openid-connect/cert
 OIDC_OP_AUTHORIZATION_ENDPOINT=http://localhost:8083/realms/meet/protocol/openid-connect/auth
 OIDC_OP_TOKEN_ENDPOINT=http://nginx:8083/realms/meet/protocol/openid-connect/token
 OIDC_OP_USER_ENDPOINT=http://nginx:8083/realms/meet/protocol/openid-connect/userinfo
+OIDC_OP_INTROSPECTION_ENDPOINT=http://nginx:8083/realms/meet/protocol/openid-connect/token/introspect
+OIDC_OP_URL=http://localhost:8083/realms/meet
 
 OIDC_RP_CLIENT_ID=meet
 OIDC_RP_CLIENT_SECRET=ThisIsAnExampleKeyForDevPurposeOnly
@@ -45,6 +47,9 @@ LOGOUT_REDIRECT_URL=http://localhost:3000
 OIDC_REDIRECT_ALLOWED_HOSTS=localhost:8083,localhost:3000
 OIDC_AUTH_REQUEST_EXTRA_PARAMS={"acr_values": "eidas1"}
 
+OIDC_RS_CLIENT_ID=meet
+OIDC_RS_CLIENT_SECRET=ThisIsAnExampleKeyForDevPurposeOnly
+
 # Livekit Token settings
 LIVEKIT_API_SECRET=secret
 LIVEKIT_API_KEY=devkey

src/backend/core/external_api/authentication.py

@@ -4,8 +4,10 @@ import logging
 
 from django.conf import settings
 from django.contrib.auth import get_user_model
+from django.core.exceptions import SuspiciousOperation
 
-import jwt
+import jwt as pyJwt
+from lasuite.oidc_resource_server.backend import ResourceServerBackend as LaSuiteBackend
 from rest_framework import authentication, exceptions
 
 User = get_user_model()
@@ -25,9 +27,11 @@ class ApplicationJWTAuthentication(authentication.BaseAuthentication):
         Returns:
             Tuple of (user, payload) if authentication successful, None otherwise
         """
+
         auth_header = authentication.get_authorization_header(request).split()
 
         if not auth_header or auth_header[0].lower() != b"bearer":
+            # Defer to next authentication backend
             return None
 
         if len(auth_header) != 2:
@@ -45,6 +49,8 @@ class ApplicationJWTAuthentication(authentication.BaseAuthentication):
     def authenticate_credentials(self, token):
         """Validate JWT token and return authenticated user.
 
+        If token is invalid, defer to next authentication backend.
+
         Args:
             token: JWT token string
 
@@ -52,29 +58,29 @@ class ApplicationJWTAuthentication(authentication.BaseAuthentication):
             Tuple of (user, payload)
 
         Raises:
-            AuthenticationFailed: If token is invalid, expired, or user not found
+            AuthenticationFailed: If token is expired, or user not found
         """
         # Decode and validate JWT
         try:
-            payload = jwt.decode(
+            payload = pyJwt.decode(
                 token,
                 settings.APPLICATION_JWT_SECRET_KEY,
                 algorithms=[settings.APPLICATION_JWT_ALG],
                 issuer=settings.APPLICATION_JWT_ISSUER,
                 audience=settings.APPLICATION_JWT_AUDIENCE,
             )
-        except jwt.ExpiredSignatureError as e:
+        except pyJwt.ExpiredSignatureError as e:
             logger.warning("Token expired")
             raise exceptions.AuthenticationFailed("Token expired.") from e
-        except jwt.InvalidIssuerError as e:
+        except pyJwt.InvalidIssuerError as e:
             logger.warning("Invalid JWT issuer: %s", e)
             raise exceptions.AuthenticationFailed("Invalid token.") from e
-        except jwt.InvalidAudienceError as e:
+        except pyJwt.InvalidAudienceError as e:
             logger.warning("Invalid JWT audience: %s", e)
             raise exceptions.AuthenticationFailed("Invalid token.") from e
-        except jwt.InvalidTokenError as e:
+        except pyJwt.InvalidTokenError:
-            logger.warning("Invalid JWT token: %s", e)
+            # Invalid JWT token - defer to next authentication backend
-            raise exceptions.AuthenticationFailed("Invalid token.") from e
+            return None
 
         user_id = payload.get("user_id")
         client_id = payload.get("client_id")
@@ -107,3 +113,55 @@ class ApplicationJWTAuthentication(authentication.BaseAuthentication):
     def authenticate_header(self, request):
         """Return authentication scheme for WWW-Authenticate header."""
         return "Bearer"
+
+
+class ResourceServerBackend(LaSuiteBackend):
+    """OIDC Resource Server backend for user creation and retrieval."""
+
+    def get_or_create_user(self, access_token, id_token, payload):
+        """Get or create user from OIDC token claims.
+
+        Despite the LaSuiteBackend's method name suggesting "get_or_create",
+        its implementation only performs a GET operation.
+        Create new user from the sub claim.
+
+        Args:
+            access_token: The access token string
+            id_token: The ID token string (unused)
+            payload: Token payload dict (unused)
+
+        Returns:
+            User instance
+
+        Raises:
+            SuspiciousOperation: If user info validation fails
+        """
+
+        sub = payload.get("sub")
+
+        if sub is None:
+            message = "User info contained no recognizable user identification"
+            logger.debug(message)
+            raise SuspiciousOperation(message)
+
+        user = self.get_user(access_token, id_token, payload)
+
+        if user is None and settings.OIDC_CREATE_USER:
+            user = self.create_user(sub)
+
+        return user
+
+    def create_user(self, sub):
+        """Create new user from subject claim.
+
+        Args:
+            sub: Subject identifier from token
+
+        Returns:
+            Newly created User instance
+        """
+        user = self.UserModel(sub=sub)
+        user.set_unusable_password()
+        user.save()
+
+        return user

src/backend/core/external_api/viewsets.py

@@ -9,6 +9,7 @@ from django.core.exceptions import ValidationError
 from django.core.validators import validate_email
 
 import jwt
+from lasuite.oidc_resource_server.authentication import ResourceServerAuthentication
 from rest_framework import decorators, mixins, viewsets
 from rest_framework import (
     exceptions as drf_exceptions,
@@ -149,7 +150,10 @@ class RoomViewSet(
     - create: Create a new room owned by the user (requires 'rooms:create' scope)
     """
 
-    authentication_classes = [authentication.ApplicationJWTAuthentication]
+    authentication_classes = [
+        authentication.ApplicationJWTAuthentication,
+        ResourceServerAuthentication,
+    ]
     permission_classes = [
         api.permissions.IsAuthenticated & permissions.HasRequiredRoomScope
     ]

src/backend/core/tests/test_external_api_rooms.py

@@ -10,13 +10,14 @@ from django.conf import settings
 
 import jwt
 import pytest
+import responses
 from rest_framework.test import APIClient
 
 from core.factories import (
     RoomFactory,
     UserFactory,
 )
-from core.models import ApplicationScope, RoleChoices, Room
+from core.models import ApplicationScope, RoleChoices, Room, RoomAccessLevel, User
 
 pytestmark = pytest.mark.django_db
 
@@ -90,13 +91,29 @@ def test_api_rooms_list_with_expired_token(settings):
     assert "expired" in str(response.data).lower()
 
 
-def test_api_rooms_list_with_invalid_token():
+@responses.activate
-    """Listing rooms with invalid token should return 401."""
+def test_api_rooms_list_with_invalid_token(settings):
+    """Listing rooms with invalid token should return 400."""
+
+    settings.OIDC_OP_INTROSPECTION_ENDPOINT = "https://oidc.example.com/introspect"
+    settings.OIDC_OP_URL = "https://oidc.example.com"
+
+    responses.add(
+        responses.POST,
+        "https://oidc.example.com/introspect",
+        json={
+            "iss": "https://oidc.example.com",
+            "active": False,
+        },
+    )
+
     client = APIClient()
     client.credentials(HTTP_AUTHORIZATION="Bearer invalid-token-123")
     response = client.get("/external-api/v1.0/rooms/")
 
-    assert response.status_code == 401
+    # Return 400 instead of 401 because ResourceServerAuthentication raises
+    # SuspiciousOperation when the introspected user is not active
+    assert response.status_code == 400
 
 
 def test_api_rooms_list_missing_scope(settings):
@@ -332,3 +349,219 @@ def test_api_rooms_token_missing_client_id(settings):
 
     assert response.status_code == 401
     assert "Invalid token claims." in str(response.data)
+
+
+@responses.activate
+def test_resource_server_creates_user_on_first_authentication(settings):
+    """New user should be created during first authentication.
+
+    Verifies that the ResourceServerBackend.get_or_create_user() creates a user
+    in the database when authenticating with a token from an unknown subject (sub).
+    This tests the user creation workflow during the OIDC introspection process.
+    """
+
+    with pytest.raises(
+        User.DoesNotExist,
+        match="User matching query does not exist.",
+    ):
+        User.objects.get(sub="very-specific-sub")
+
+    assert (
+        settings.OIDC_RS_BACKEND_CLASS
+        == "core.external_api.authentication.ResourceServerBackend"
+    )
+
+    settings.OIDC_RS_CLIENT_ID = "some_client_id"
+    settings.OIDC_RS_CLIENT_SECRET = "some_client_secret"
+
+    settings.OIDC_OP_URL = "https://oidc.example.com"
+    settings.OIDC_VERIFY_SSL = False
+    settings.OIDC_TIMEOUT = 5
+    settings.OIDC_PROXY = None
+    settings.OIDC_OP_JWKS_ENDPOINT = "https://oidc.example.com/jwks"
+    settings.OIDC_OP_INTROSPECTION_ENDPOINT = "https://oidc.example.com/introspect"
+
+    responses.add(
+        responses.POST,
+        "https://oidc.example.com/introspect",
+        json={
+            "iss": "https://oidc.example.com",
+            "aud": "some_client_id",  # settings.OIDC_RS_CLIENT_ID
+            "sub": "very-specific-sub",
+            "client_id": "some_service_provider",
+            "scope": "openid lasuite_meet rooms:list",
+            "active": True,
+        },
+    )
+
+    client = APIClient()
+    client.credentials(HTTP_AUTHORIZATION="Bearer some_token")
+    response = client.get("/external-api/v1.0/rooms/")
+
+    assert response.status_code == 200
+
+    results = response.json()["results"]
+    assert len(results) == 0
+
+    db_user = User.objects.get(sub="very-specific-sub")
+    assert db_user is not None
+    assert db_user.email is None
+
+
+@responses.activate
+def test_resource_server_skips_user_creation_when_auto_creation_disabled(settings):
+    """Verify that ResourceServerBackend respects the user auto-creation setting.
+
+    This ensures that the OIDC introspection process respects the configuration flag
+    that controls whether new users should be automatically provisioned during
+    authentication, preventing unwanted user proliferation when auto-creation is
+    explicitly disabled.
+    """
+
+    settings.OIDC_CREATE_USER = False
+
+    with pytest.raises(
+        User.DoesNotExist,
+        match="User matching query does not exist.",
+    ):
+        User.objects.get(sub="very-specific-sub")
+
+    assert (
+        settings.OIDC_RS_BACKEND_CLASS
+        == "core.external_api.authentication.ResourceServerBackend"
+    )
+
+    settings.OIDC_RS_CLIENT_ID = "some_client_id"
+    settings.OIDC_RS_CLIENT_SECRET = "some_client_secret"
+
+    settings.OIDC_OP_URL = "https://oidc.example.com"
+    settings.OIDC_VERIFY_SSL = False
+    settings.OIDC_TIMEOUT = 5
+    settings.OIDC_PROXY = None
+    settings.OIDC_OP_JWKS_ENDPOINT = "https://oidc.example.com/jwks"
+    settings.OIDC_OP_INTROSPECTION_ENDPOINT = "https://oidc.example.com/introspect"
+
+    responses.add(
+        responses.POST,
+        "https://oidc.example.com/introspect",
+        json={
+            "iss": "https://oidc.example.com",
+            "aud": "some_client_id",  # settings.OIDC_RS_CLIENT_ID
+            "sub": "very-specific-sub",
+            "client_id": "some_service_provider",
+            "scope": "openid lasuite_meet rooms:list",
+            "active": True,
+        },
+    )
+
+    client = APIClient()
+    client.credentials(HTTP_AUTHORIZATION="Bearer some_token")
+    response = client.get("/external-api/v1.0/rooms/")
+
+    assert response.status_code == 401
+
+
+@responses.activate
+def test_resource_server_authentication_successful(settings):
+    """Authenticated requests should be processed and user-specific data is returned.
+
+    Verifies that once a user is authenticated via OIDC token introspection,
+    the API correctly identifies the user and returns only data accessible to that user
+    (e.g., rooms with appropriate access levels).
+    """
+
+    user = UserFactory(sub="very-specific-sub")
+
+    other_user = UserFactory()
+
+    RoomFactory(access_level=RoomAccessLevel.PUBLIC)
+    RoomFactory(access_level=RoomAccessLevel.TRUSTED)
+    RoomFactory(access_level=RoomAccessLevel.RESTRICTED)
+    room_user_accesses = RoomFactory(
+        access_level=RoomAccessLevel.RESTRICTED, users=[user]
+    )
+    RoomFactory(access_level=RoomAccessLevel.RESTRICTED, users=[other_user])
+
+    assert (
+        settings.OIDC_RS_BACKEND_CLASS
+        == "core.external_api.authentication.ResourceServerBackend"
+    )
+
+    settings.OIDC_RS_CLIENT_ID = "some_client_id"
+    settings.OIDC_RS_CLIENT_SECRET = "some_client_secret"
+
+    settings.OIDC_OP_URL = "https://oidc.example.com"
+    settings.OIDC_VERIFY_SSL = False
+    settings.OIDC_TIMEOUT = 5
+    settings.OIDC_PROXY = None
+    settings.OIDC_OP_JWKS_ENDPOINT = "https://oidc.example.com/jwks"
+    settings.OIDC_OP_INTROSPECTION_ENDPOINT = "https://oidc.example.com/introspect"
+
+    responses.add(
+        responses.POST,
+        "https://oidc.example.com/introspect",
+        json={
+            "iss": "https://oidc.example.com",
+            "aud": "some_client_id",  # settings.OIDC_RS_CLIENT_ID
+            "sub": "very-specific-sub",
+            "client_id": "some_service_provider",
+            "scope": "openid lasuite_meet rooms:list",
+            "active": True,
+        },
+    )
+
+    client = APIClient()
+    client.credentials(HTTP_AUTHORIZATION="Bearer some_token")
+    response = client.get("/external-api/v1.0/rooms/")
+
+    assert response.status_code == 200
+    results = response.json()["results"]
+    assert len(results) == 1
+    expected_ids = {
+        str(room_user_accesses.id),
+    }
+    results_id = {result["id"] for result in results}
+    assert expected_ids == results_id
+
+
+@responses.activate
+def test_resource_server_denies_access_with_insufficient_scopes(settings):
+    """Requests should be denied when the token lacks required scopes.
+
+    Verifies that the ResourceServerBackend validates token scopes during introspection
+    and returns 403 Forbidden when the token is missing required scopes for the endpoint.
+    """
+
+    assert (
+        settings.OIDC_RS_BACKEND_CLASS
+        == "core.external_api.authentication.ResourceServerBackend"
+    )
+
+    settings.OIDC_RS_CLIENT_ID = "some_client_id"
+    settings.OIDC_RS_CLIENT_SECRET = "some_client_secret"
+
+    settings.OIDC_OP_URL = "https://oidc.example.com"
+    settings.OIDC_VERIFY_SSL = False
+    settings.OIDC_TIMEOUT = 5
+    settings.OIDC_PROXY = None
+    settings.OIDC_OP_JWKS_ENDPOINT = "https://oidc.example.com/jwks"
+    settings.OIDC_OP_INTROSPECTION_ENDPOINT = "https://oidc.example.com/introspect"
+
+    responses.add(
+        responses.POST,
+        "https://oidc.example.com/introspect",
+        json={
+            "iss": "https://oidc.example.com",
+            "aud": "some_client_id",  # settings.OIDC_RS_CLIENT_ID
+            "sub": "very-specific-sub",
+            "client_id": "some_service_provider",
+            "scope": "openid lasuite_meet",  # missing rooms:list scope
+            "active": True,
+        },
+    )
+
+    client = APIClient()
+    client.credentials(HTTP_AUTHORIZATION="Bearer some_token")
+    response = client.get("/external-api/v1.0/rooms/")
+
+    assert response.status_code == 403

src/backend/meet/settings.py

@@ -10,6 +10,8 @@ For the full list of settings and their values, see
 https://docs.djangoproject.com/en/3.1/ref/settings/
 """
 
+# pylint: disable=too-many-lines
+
 import json
 from os import path
 from socket import gethostbyname, gethostname
@@ -404,6 +406,10 @@ class Base(Configuration):
         default=False,
         environ_name="OIDC_FALLBACK_TO_EMAIL_FOR_IDENTIFICATION",
     )
+    OIDC_TIMEOUT = values.IntegerValue(
+        5, environ_name="OIDC_TIMEOUT", environ_prefix=None
+    )
+    OIDC_PROXY = values.Value(None, environ_name="OIDC_PROXY", environ_prefix=None)
     OIDC_RP_SIGN_ALGO = values.Value(
         "RS256", environ_name="OIDC_RP_SIGN_ALGO", environ_prefix=None
     )
@@ -427,12 +433,16 @@ class Base(Configuration):
     OIDC_OP_USER_ENDPOINT = values.Value(
         None, environ_name="OIDC_OP_USER_ENDPOINT", environ_prefix=None
     )
+    OIDC_OP_INTROSPECTION_ENDPOINT = values.Value(
+        None, environ_name="OIDC_OP_INTROSPECTION_ENDPOINT", environ_prefix=None
+    )
     OIDC_OP_USER_ENDPOINT_FORMAT = values.Value(
         "AUTO", environ_name="OIDC_OP_USER_ENDPOINT_FORMAT", environ_prefix=None
     )
     OIDC_OP_LOGOUT_ENDPOINT = values.Value(
         None, environ_name="OIDC_OP_LOGOUT_ENDPOINT", environ_prefix=None
     )
+    OIDC_OP_URL = values.Value(None, environ_name="OIDC_OP_URL", environ_prefix=None)
     OIDC_AUTH_REQUEST_EXTRA_PARAMS = values.DictValue(
         {}, environ_name="OIDC_AUTH_REQUEST_EXTRA_PARAMS", environ_prefix=None
     )
@@ -493,6 +503,42 @@ class Base(Configuration):
         environ_prefix=None,
     )
 
+    # OIDC Resource Server Backend
+    OIDC_RS_BACKEND_CLASS = "core.external_api.authentication.ResourceServerBackend"
+    OIDC_RS_CLIENT_ID = values.Value(
+        "meet", environ_name="OIDC_RS_CLIENT_ID", environ_prefix=None
+    )
+    OIDC_RS_CLIENT_SECRET = SecretFileValue(
+        None,
+        environ_name="OIDC_RS_CLIENT_SECRET",
+        environ_prefix=None,
+    )
+    OIDC_RS_AUDIENCE_CLAIM = values.Value(
+        default="client_id", environ_name="OIDC_RS_AUDIENCE_CLAIM", environ_prefix=None
+    )
+    OIDC_RS_ENCRYPTION_ENCODING = values.Value(
+        default="A256GCM",
+        environ_name="OIDC_RS_ENCRYPTION_ENCODING",
+        environ_prefix=None,
+    )
+    OIDC_RS_ENCRYPTION_ALGO = values.Value(
+        default="RSA-OAEP", environ_name="OIDC_RS_ENCRYPTION_ALGO", environ_prefix=None
+    )
+    OIDC_RS_SIGNING_ALGO = values.Value(
+        default="ES256", environ_name="OIDC_RS_SIGNING_ALGO", environ_prefix=None
+    )
+    OIDC_RS_SCOPES = values.ListValue(
+        default=["lasuite_meet"],
+        environ_name="OIDC_RS_SCOPES",
+        environ_prefix=None,
+    )
+    OIDC_RS_PRIVATE_KEY_STR = SecretFileValue(
+        environ_name="OIDC_RS_PRIVATE_KEY_STR", environ_prefix=None
+    )
+    OIDC_RS_ENCRYPTION_KEY_TYPE = values.Value(
+        default="RSA", environ_name="OIDC_RS_ENCRYPTION_KEY_TYPE", environ_prefix=None
+    )
+
     # Video conference configuration
     LIVEKIT_CONFIGURATION = {
         "api_key": SecretFileValue(environ_name="LIVEKIT_API_KEY", environ_prefix=None),

src/backend/meet/urls.py

@@ -15,6 +15,7 @@ from drf_spectacular.views import (
 urlpatterns = [
     path("admin/", admin.site.urls),
     path("", include("core.urls")),
+    path("", include("lasuite.oidc_resource_server.urls")),
 ]
 
 if settings.DEBUG:

src/backend/pyproject.toml

@@ -32,7 +32,7 @@ dependencies = [
     "django-configurations==2.5.1",
     "django-cors-headers==4.9.0",
     "django-countries==8.0.0",
-    "django-lasuite[all]==0.0.17",
+    "django-lasuite[all]==0.0.19",
     "django-parler==2.3",
     "redis==5.2.1",
     "django-redis==6.0.0",