Files
meet/src/backend/core/authentication/backends.py
T
lebaudantoine e42b083f20 🛂(backend) reject user access tokens on the API
The original implementation, introduced two years ago, was incorrect
and exposed the API to an undesired authentication mode: any user
access token obtained for a given user was being accepted as valid
credentials on the external API.

Restrict authentication to the intended mode so that user access
tokens are no longer accepted on this API.

Thanks @lunika spotting this.
2026-07-01 11:24:59 +02:00

114 lines
3.9 KiB
Python

"""Authentication Backends for the Meet core app."""
import contextlib
from django.conf import settings
from django.core.exceptions import ImproperlyConfigured, SuspiciousOperation
from django.utils.translation import gettext_lazy as _
from lasuite.oidc_login.backends import (
OIDCAuthenticationBackend as LaSuiteOIDCAuthenticationBackend,
)
from rest_framework.authentication import SessionAuthentication
from core.models import User
from core.services.marketing import (
ContactCreationError,
ContactData,
get_marketing_service,
)
class OIDCAuthenticationBackend(LaSuiteOIDCAuthenticationBackend):
"""Custom OpenID Connect (OIDC) Authentication Backend.
This class overrides the default OIDC Authentication Backend to accommodate differences
in the User and Identity models, and handles signed and/or encrypted UserInfo response.
"""
def get_extra_claims(self, user_info):
"""
Return extra claims from user_info.
Args:
user_info (dict): The user information dictionary.
Returns:
dict: A dictionary of extra claims.
"""
return {
# Get user's full name from OIDC fields defined in settings
"full_name": self.compute_full_name(user_info),
"short_name": user_info.get(settings.OIDC_USERINFO_SHORTNAME_FIELD),
}
def post_get_or_create_user(self, user, claims, is_new_user):
"""
Post-processing after user creation or retrieval.
Args:
user (User): The user instance.
claims (dict): The claims dictionary.
is_new_user (bool): Indicates if the user was newly created.
Returns:
- None
"""
email = claims["email"]
if is_new_user and email and settings.SIGNUP_NEW_USER_TO_MARKETING_EMAIL:
self.signup_to_marketing_email(email)
@staticmethod
def signup_to_marketing_email(email):
"""Pragmatic approach to newsletter signup during authentication flow.
Details:
1. Uses a very short timeout (1s) to prevent blocking the auth process
2. Silently fails if the marketing service is down/slow to prioritize user experience
3. Trade-off: May miss some signups but ensures auth flow remains fast
Note: For a more robust solution, consider using Async task processing (Celery/Django-Q)
"""
with contextlib.suppress(
ContactCreationError, ImproperlyConfigured, ImportError
):
marketing_service = get_marketing_service()
contact_data = ContactData(
email=email, attributes={"VISIO_SOURCE": ["SIGNIN"]}
)
marketing_service.create_contact(
contact_data, timeout=settings.BREVO_API_TIMEOUT
)
def get_existing_user(self, sub, email):
"""Fetch existing user by sub or email."""
try:
return User.objects.get(sub=sub)
except User.DoesNotExist:
if email and settings.OIDC_FALLBACK_TO_EMAIL_FOR_IDENTIFICATION:
try:
return User.objects.get(email__iexact=email)
except User.DoesNotExist:
pass
except User.MultipleObjectsReturned as e:
raise SuspiciousOperation(
"Multiple user accounts share a common email."
) from e
return None
class SessionAuthenticationWith401(SessionAuthentication):
"""
Identical to DRF's SessionAuthentication, but returns a WWW-Authenticate
header so unauthenticated requests get a 401 instead of a 403.
The scheme is deliberately NOT 'Basic' — that would trigger the browser's
native login popup. 'Session' is ignored by the browser's auth UI but is
still truthy, so DRF keeps the status at 401.
"""
def authenticate_header(self, request):
return "Session"