I’m integrating Microsoft SSO into my Django app, and I’m encountering a “State Mismatch” error during the login process. This error occurs when the state parameter, which is used to prevent cross-site request forgery (CSRF) attacks, doesn’t match the expected value.
What’s Happening:
During the login process, my Django app generates a state parameter and stores it in the user’s session. When the user is redirected back to my app from Microsoft after authentication, the state parameter returned by Microsoft should match the one stored in the session. However, in my case, the two values don’t match, resulting in a State Mismatch Error.
ERROR:django.security.SSOLogin: State mismatch during Microsoft SSO login.
State received from the callback URL:
state = request.GET.get('state')
State stored in the session during SSO initiation:
session_state = request.session.get('oauth2_state')
In the logs, I can see that the session state is either missing or mismatched. Here’s the log snippet:
Received state in callback: b8bfae27-xxxx-xxxx-xxxxxxxxx
Session state before validation: None
The callback state is b8bfae27-xxx-xxxx-xxxx-xxxxxxxxxxx, but the session state is None. This leads to a state mismatch and ultimately the login failure.
- Expected state: The state value generated by my app and stored in the session.
- Returned state: The state value returned by Microsoft after the user completes authentication.
- Session ID: The session key for the user during the login attempt.
What I’ve Tried:
- Session Persistence: I verified that session data is being correctly stored and retrieved during the login process.
- Time Synchronization: I checked that the time on my server and Microsoft’s authentication server is synchronized to avoid potential timing issues.
- Cache Settings: I’m currently using
LocMemCachefor caching and session management in local development, but I suspect this may be causing issues in Azure due to its lack of persistence across multiple instances. - SSO Settings: I reviewed the Microsoft SSO settings and ensured the correct URLs and callback mechanisms are being used.
Django & Azure Configuration:
- Django version: 5.0.6
- Python version: 3.12
- SSO Integration Package:
django-microsoft-sso - Cache backend:
LocMemCache(planning to switch to Redis) - Azure App Service: Hosted with App Service Plan for deployment.
- Time Zone: Central Time (US & Canada) on local development and UTC on the Azure server.
from django.shortcuts import render, redirect
from django.urls import reverse
from django.contrib.auth import login
from django.utils.timezone import now
from django.http import JsonResponse
from django.views.decorators.csrf import csrf_exempt
import binascii
import os
import logging
logger = logging.getLogger(__name__)
def login_failed(request):
# Log basic failure info
logger.debug(f"Login failed at {now()}.")
# Render failure message
context = {'message': 'We were unable to log you in using Microsoft SSO.'}
return render(request, 'claims/login_failed.html', context)
# View to handle Microsoft SSO callback
[u/csrf_exempt](https://www.reddit.com/user/csrf_exempt/)
def microsoft_sso_callback(request):
# Log basic info for debugging
logger.debug(f"SSO callback triggered at {now()}")
# Retrieve state from the callback and session
state = request.GET.get('state')
session_state = request.session.get('oauth2_state')
# Check for state mismatch or missing state
if not state or state != session_state:
logger.error(f"State mismatch or state missing. Received: {state}, Expected: {session_state}")
request.session.flush() # Clear session to test if a fresh session resolves it
return redirect(reverse('login_failed'))
# Process the Microsoft user data
microsoft_user = getattr(request, 'microsoft_user', None)
if microsoft_user:
email = microsoft_user.get('email')
if email:
try:
user = User.objects.get(email=email)
# Log the user in using the correct backend
login(request, user, backend='django.contrib.auth.backends.ModelBackend')
return redirect('admin:index')
except User.DoesNotExist:
return redirect(reverse('login_failed'))
else:
return redirect(reverse('login_failed'))
else:
return redirect(reverse('login_failed'))
# View to initiate the Microsoft SSO login process
def sso_login(request):
# Generate a secure random state
state = binascii.hexlify(os.urandom(16)).decode()
# Store state in session and save
request.session['oauth2_state'] = state
request.session.save()
# Build the Microsoft login URL
login_url = '[https://login.microsoftonline.com/{}/oauth2/v2.0/authorize'.format(settings.MICROSOFT_SSO_TENANT_ID)](https://login.microsoftonline.com/%7B%7D/oauth2/v2.0/authorize'.format(settings.MICROSOFT_SSO_TENANT_ID))
params = {
'client_id': settings.MICROSOFT_SSO_APPLICATION_ID,
'response_type': 'code',
'redirect_uri': settings.MICROSOFT_SSO_REDIRECT_URI,
'response_mode': 'query',
'scope': ' '.join(settings.MICROSOFT_SSO_SCOPES),
'state': state,
}
login_url_with_params = f"{login_url}?{'&'.join(f'{key}={value}' for key, value in params.items())}"
return redirect(login_url_with_params)