Django Web Authentication with Keycloak

Django is a high-level, open-source web framework for building web applications using the Python programming language. It follows the Model-View-Controller (MVC) architectural pattern.

In this article we'll be using Keycloak to secure a Django Web application.

Phase Two is a Keycloak as a Service provider enabling SaaS builders to accelerate time-to-market with powerful enterprise features like SSO, identity, and user management features. Phase Two enhances Keycloak through a variety of open-source extentions for modern SaaS use cases. Phase Two supports both hosted and on-premise deployment options.

What is Keycloak?

Keycloak has been a leader in the Identity and Access Management world since its launch almost 8 years ago. It is an open-source offering under the stewardship of Red Hat

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If you just want to skip to the code, visit the Phase Two Django example. We are also building Keycloak examples for other frameworks.

TOC

• Django Project Setup
• Keycloak Setup
• Django OIDC + Keycloak Integration

Setting up a Django Project

The following could be applied to an existing Django application, but we have chosen to use the excellent tutorial application built by Mozilla as our example. If you aren't yet familiar with Django, we encourage you to follow the tutorial there.

The completed code for that tutorial is available in their GitHub repository. We'll clone it to get started.

Quick Start

To get this project up and running locally on your computer:

1. Set up the Python development environment. We recommend using a Python virtual environment.
2. Assuming you have Python setup, run the following commands (if you're on Windows you may use py or py -3 instead of python to start Python):

   pip install -r requirements.txt
   python manage.py makemigrations
   python manage.py migrate
   python manage.py collectstatic
   python manage.py test # Run the standard tests. These should all pass.
   python manage.py createsuperuser # Create a superuser
   python manage.py runserver

1. Open a browser to http://127.0.0.1:8000/admin/ to open the admin site
2. Create a few test objects of each type.
3. Open tab to http://127.0.0.1:8000 to see the main site, with your new objects.

Setting up a Keycloak Instance

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If you already have a functioning Keycloak instance, you can skip to the next section.

Setting up an OIDC Client

We need to create a OpenID Connect Client in Keycloak for the app to communicate with.

OIDC Config

Adding a Non-Admin User

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It is bad practice to use your Admin user to sign in to an Application.

Since we do not want to use our Admin user for signing into the app we will build, we need to add another non-admin user.

Install and configure the Django OIDC library

Now that we've installed and configured Keycloak, we need to setup Django to replace the native authentication method provided by the framework. The first task is to install a library that is compatible with Keycloak's OIDC implementation.

The mozilla-django-oidc library provides an easy way to integrate Keycloak (or any OpenID Connect-compliant identity provider) with your Django app. It abstracts many of the complexities of integrating authentication and authorization. Here's how you can set it up:

1. Install the Package: Install the mozilla-django-oidc package using pip:

   pip install mozilla-django-oidc

1. Configure Django Settings: Update your Django app's settings.py to include the necessary configurations for mozilla-django-oidc:

   INSTALLED_APPS = [
       # ...
       'django.contrib.auth',
       'mozilla_django_oidc',  # Load after django.contrib.auth
       # ...
   ]

   AUTHENTICATION_BACKENDS = (
       'mozilla_django_oidc.auth.OIDCAuthenticationBackend',
       # ...
   )

   OIDC_RP_CLIENT_ID = 'your-client-id'
   OIDC_RP_CLIENT_SECRET = 'your-client-secret'
   OIDC_OP_AUTHORIZATION_ENDPOINT = 'https://keycloak-url/auth/realms/your-realm/protocol/openid-connect/auth'
   OIDC_OP_TOKEN_ENDPOINT = 'https://keycloak-url/auth/realms/your-realm/protocol/openid-connect/token'
   OIDC_OP_USER_ENDPOINT = 'https://keycloak-url/auth/realms/your-realm/protocol/openid-connect/userinfo'
   OIDC_OP_JWKS_ENDPOINT = 'https://keycloak-url/auth/realms/your-realm/protocol/openid-connect/certs'
   OIDC_RP_SIGN_ALGO = 'RS256'

   LOGIN_URL = 'oidc_authentication_init'
   LOGOUT_REDIRECT_URL = '/'
   LOGIN_REDIRECT_URL = '/'

Replace your-client-id, your-client-secret, and the Keycloak URLs with your actual Keycloak configurations.

1. Add URLs: Update your Django app's urls.py to include the authentication URLs provided by mozilla-django-oidc:

   urlpatterns += [
       path('oidc/', include('mozilla_django_oidc.urls')),
   ]

Using it in your app

Protect your views

Use Decorators for Access Control. You can now use the @oidc_protected decorator to protect views that require authentication and potentially specific roles:

from mozilla_django_oidc.decorators import oidc_protected

@oidc_protected
def protected_view(request):
    # Your view logic

Accessing user information

You can access user information after authentication using the request.oidc_user attribute. For example:

def profile_view(request):
    user_info = request.oidc_user.userinfo
    # Access user_info['sub'], user_info['email'], etc.
    # Your view logic

By default, mozilla-django-oidc looks up a Django user matching the email field to the email address returned in the user info data from Keycloak.

If a user logs into your site and doesn’t already have an account, by default, mozilla-django-oidc will create a new Django user account. It will create the User instance filling in the username (hash of the email address) and email fields.

Use Username rather than Email

mozilla-django-oidc defaults to setting up Django users using the email address as the user name from keycloak was required. Fortunately, preferred_username is set up by default in Keycloak as a claim. The claim can used by overriding the OIDCAuthenticationBackend class in mozilla_django_oidc.auth and referring to this in AUTHENTICATION_BACKENDS as below:

# Classes to override default OIDCAuthenticationBackend (Keycloak authentication)
from mozilla_django_oidc.auth import OIDCAuthenticationBackend

class KeycloakOIDCAuthenticationBackend(OIDCAuthenticationBackend):

 def create_user(self, claims):
     """ Overrides Authentication Backend so that Django users are
         created with the keycloak preferred_username.
         If nothing found matching the email, then try the username.
     """
     user = super(KeycloakOIDCAuthenticationBackend, self).create_user(claims)
     user.first_name = claims.get('given_name', '')
     user.last_name = claims.get('family_name', '')
     user.email = claims.get('email')
     user.username = claims.get('preferred_username')
     user.save()
     return user

 def filter_users_by_claims(self, claims):
     """ Return all users matching the specified email.
         If nothing found matching the email, then try the username
     """
     email = claims.get('email')
     preferred_username = claims.get('preferred_username')

     if not email:
         return self.UserModel.objects.none()
     users = self.UserModel.objects.filter(email__iexact=email)

     if len(users) < 1:
         if not preferred_username:
             return self.UserModel.objects.none()
         users = self.UserModel.objects.filter(username__iexact=preferred_username)
     return users

 def update_user(self, user, claims):
     user.first_name = claims.get('given_name', '')
     user.last_name = claims.get('family_name', '')
     user.email = claims.get('email')
     user.username = claims.get('preferred_username')
     user.save()
     return user

In settings.py, overide the new library you have just added in AUTHENTICATION_BACKENDS :

 # mozilla_django_oidc - Keycloak authentication
 "fragalysis.auth.KeycloakOIDCAuthenticationBackend",

Logging out

You can use the @oidc_logout decorator to log the user out of both your app and Keycloak:

from mozilla_django_oidc.decorators import oidc_logout

@oidc_logout
def logout_view(request):
    # Your logout view logic

Add support for Django Rest Framework

Django Rest Framework (DRF) is a flexible toolkit built on top of Django, specifically designed for building RESTful APIs.

If you want DRF to authenticate users based on an OAuth access token provided in the Authorization header, you can use the DRF-specific authentication class which ships with the package.

Add this to your settings:

REST_FRAMEWORK = {
    'DEFAULT_AUTHENTICATION_CLASSES': [
        'mozilla_django_oidc.contrib.drf.OIDCAuthentication',
        'rest_framework.authentication.SessionAuthentication',
        # other authentication classes, if needed
    ],
}

Note that this only takes care of authenticating against an access token, and provides no options to create or renew tokens.

If you’ve created a custom Django OIDCAuthenticationBackend and added that to your AUTHENTICATION_BACKENDS, the DRF class should be smart enough to figure that out. Alternatively, you can manually set the OIDC backend to use:

OIDC_DRF_AUTH_BACKEND = 'mozilla_django_oidc.auth.OIDCAuthenticationBackend'

Learning more

Phase Two's enhanced Keycloak provides many ways to quickly control and tweak the log in and user management experience. Our blog has many use cases from customizing login pages, setting up magic links (password-less sign in), and Organization workflows.