Custom edX authentication backends and pipeline steps


Keywords
authentication, edx, oauth2, oidc, openid-connect, python
License
Other
Install
pip install edx-auth-backends==3.0.2

Documentation

auth-backends Travis Codecov

This package contains custom authentication backends, views, and pipeline steps used by edX services for single sign-on.

This package is compatible with Python 2.7 and 3.5, and Django 1.11 through 2.2.

We currently support OAuth 2.0 authentication. Support for OpenID Connect (OIDC) was removed as of version 3.0. Use version 2.x if you require OIDC and are not able to migrate to OAuth2.

Installation

The auth_backends package can be installed from PyPI using pip:

$ pip install edx-auth-backends

Update INSTALLED_APPS:

INSTALLED_APPS = (
    'social_django',
)

Configuration

Adding single sign-on/out support to a service requires a few changes:

  1. Define settings
  2. Add the authentication backend
  3. Add the login/logout redirects

OAuth 2.0 Settings

Setting Purpose
SOCIAL_AUTH_EDX_OAUTH2_KEY Client key
SOCIAL_AUTH_EDX_OAUTH2_SECRET Client secret
SOCIAL_AUTH_EDX_OAUTH2_URL_ROOT LMS root, reachable from the application server (e.g. https://courses.stage.edx.org or http://edx.devstack.lms:18000)
SOCIAL_AUTH_EDX_OAUTH2_PUBLIC_URL_ROOT LMS root, reachable from the end user's browser (e.g. https://courses.stage.edx.org or http://localhost:18000)
SOCIAL_AUTH_EDX_OAUTH2_JWS_HMAC_SIGNING_KEY (Optional) Shared secret for JWT signed with HS512 algorithm
SOCIAL_AUTH_EDX_OAUTH2_PROVIDER_CONFIGURATION_CACHE_TTL (Optional) Cache timeout for provider configuration. Defaults to 1 week.
SOCIAL_AUTH_EDX_OAUTH2_JWKS_CACHE_TTL (Optional) Cache timeout for provider's JWKS key data. Defaults to 1 day.

OAuth2 Applications require access to the user_id scope in order for the EdXOAuth2 backend to work. The backend will write the user_id into the social-auth extra_data, and can be accessed within the User model as follows:

self.social_auth.first().extra_data[u'user_id']  # pylint: disable=no-member

Strategy

We use a custom strategy that includes many of the default settings necessary to utilize single sign-on for edX services. This strategy should be used for all services to simplify configuration. If you need to override the defaults, you may still do so as you would with any social auth setting——prepend SOCIAL_AUTH_ to the setting name. Add the following to your Django settings to use the strategy:

SOCIAL_AUTH_STRATEGY = 'auth_backends.strategies.EdxDjangoStrategy'

Authentication Backend

Configuring the backend is simply a matter of updating the AUTHENTICATION_BACKENDS setting. The configuration below is sufficient for all edX services.

AUTHENTICATION_BACKENDS = (
    'auth_backends.backends.EdXOAuth2',
    'django.contrib.auth.backends.ModelBackend',
)

Authentication Views

In order to make use of the authentication backend, your service's login/logout views need to be updated. The login view should be updated to redirect to the authentication provider's login page. The logout view should be updated to redirect to the authentication provider's logout page.

This package includes views and urlpatterns configured for OAuth 2.0. To use them, simply append/prepend oauth2_urlpatterns to your service's urlpatterns in urls.py.

from auth_backends.urls import oauth2_urlpatterns

urlpatterns = oauth2_urlpatterns + [
    url(r'^admin/', include(admin.site.urls)),
    ...
]

It is recommended that you not modify the login view. If, however, you need to modify the logout view (to redirect to a different URL, for example), you can subclass EdxOAuth2LogoutView for the view and LogoutViewTestMixin for your tests.

Testing

Call make test.

License

The code in this repository is licensed under the AGPL unless otherwise noted.

Please see LICENSE.txt for details.

How To Contribute

Contributions are very welcome!

Please read How To Contribute for details.

Even though it was written with edx-platform in mind, the guidelines should be followed for Open edX code in general.

Reporting Security Issues

Please do not report security issues in public. Please email security@edx.org.

Mailing List and IRC Channel

You can discuss this code on the edx-code Google Group or in the #edx-code IRC channel on Freenode.