Part 2 - protect your APIs

Scenario

It’s very common for an Authorization Server to also be the Resource Server, usually exposing an API to let others access its own resources. Django OAuth Toolkit implements an easy way to protect the views of a Django application with OAuth2, in this tutorial we will see how to do it.

Make your API

We start where we left the part 1 of the tutorial: you have an authorization server and we want it to provide an API to access some kind of resources. We don’t need an actual resource, so we will simply expose an endpoint protected with OAuth2: let’s do it in a class based view fashion!

Django OAuth Toolkit provides a set of generic class based view you can use to add OAuth behaviour to your views. Open your views.py module and import the view:

from oauth2_provider.views.generic import ProtectedResourceView
from django.http import HttpResponse

Then create the view which will respond to the API endpoint:

class ApiEndpoint(ProtectedResourceView):
    def get(self, request, *args, **kwargs):
        return HttpResponse('Hello, OAuth2!')

That’s it, our API will expose only one method, responding to GET requests. Now open your urls.py and specify the URL this view will respond to:

from django.conf.urls import url, include
import oauth2_provider.views as oauth2_views
from django.conf import settings
from .views import ApiEndpoint
# OAuth2 provider endpoints
oauth2_endpoint_views = [
    path('authorize/', oauth2_views.AuthorizationView.as_view(), name="authorize"),
    path('token/', oauth2_views.TokenView.as_view(), name="token"),
    path('revoke-token/', oauth2_views.RevokeTokenView.as_view(), name="revoke-token"),
]
if settings.DEBUG:
    # OAuth2 Application Management endpoints
    oauth2_endpoint_views += [
        path('applications/', oauth2_views.ApplicationList.as_view(), name="list"),
        path('applications/register/', oauth2_views.ApplicationRegistration.as_view(), name="register"),
        path('applications/<pk>/', oauth2_views.ApplicationDetail.as_view(), name="detail"),
        path('applications/<pk>/delete/', oauth2_views.ApplicationDelete.as_view(), name="delete"),
        path('applications/<pk>/update/', oauth2_views.ApplicationUpdate.as_view(), name="update"),
    ]
    # OAuth2 Token Management endpoints
    oauth2_endpoint_views += [
        path('authorized-tokens/', oauth2_views.AuthorizedTokensListView.as_view(), name="authorized-token-list"),
        path('authorized-tokens/<pk>/delete/', oauth2_views.AuthorizedTokenDeleteView.as_view(),
            name="authorized-token-delete"),
    ]
urlpatterns = [
    # OAuth 2 endpoints:
    path('o/', include(oauth2_endpoint_views, namespace="oauth2_provider")),
    path('api/hello', ApiEndpoint.as_view()),  # an example resource endpoint
]

You will probably want to write your own application views to deal with permissions and access control but the ones packaged with the library can get you started when developing the app.

Since we inherit from ProtectedResourceView, we’re done and our API is OAuth2 protected - for the sake of the lazy programmer.

Testing your API

Time to make requests to your API.

For a quick test, try accessing your app at the url /api/hello with your browser and verify that it responds with a 403 (in fact no HTTP_AUTHORIZATION header was provided). You can test your API with anything that can perform HTTP requests, but for this tutorial you can use the online consumer client. Just fill the form with the URL of the API endpoint (i.e. http://localhost:8000/api/hello if you’re on localhost) and the access token coming from the part 1 of the tutorial. Going in the Django admin and get the token from there is not considered cheating, so it’s an option.

Try performing a request and check that your Resource Server aka Authorization Server correctly responds with an HTTP 200.

Part 3 of the tutorial will show how to use an access token to authenticate users.