Generate an OAuth2 token in a view - django

Question

Let's say I have an AngularJS application that consumes the REST API of a Django application.
The Django application has got a built-in OAuth2 provider that can be called to retrieve an access token and use the protected endpoints of the API. This provider is using django-oauth-toolkit.
Let's assume there is a registered client with "password" grant type, so that the end users only need to provide their credentials in the front-end in order to get an access token from the back-end.
At some point we want to add some support for social networks login and we decide to use python-social-auth (PSA) to that end. Here is the workflow I want to achieve:
The user logs in on Facebook from the front-end (via the Facebook SDK) and we get an access token back from the OAuth2 provider of Facebook.
We send the Facebook token to an endpoint of our REST API. This endpoint uses the Facebook token and django-social-auth to authenticate the user in our Django application (basically matching a Facebook account to a standard account within the app).
If the authentication succeeds, the API endpoint requests an access token from the OAuth2 provider for this newly authenticated user.
The Django access token is sent back to the front-end and can be used to access the REST API in exactly the same way that a regular user (i.e. logged in with his credentials) would do.
Now my problem is: how do I achieve step 3? I first thought I would register a separate OAuth2 client with Client Credentials Grant but then the generated token is not user-specific so it does not make sense. Another option is to use the TokenAuthentication from DRF but that would add too much complexity to my project. I already have an OAuth server and I don't want to set up a second token provider to circumvent my problem, unless this is the only solution.
I think my understanding of PSA and django-oauth-toolkit is not deep enough to find the best way of reaching my goal, but there must be a way. Help!

Answer 1

I managed to get something working using urllib2. I can't speak towards whether or not this is good practice, but I can successfully generate an OAuth2 token within a view.
Normally when I'd generate an access token with cURL, it'd look like this:
curl -X POST -d "grant_type=password&username=<user_name>&password=<password>" -u"<client_id>:<client_secret>" http://localhost:8000/o/token/
So we're tasked with making urllib2 accomplish this. After playing around for some bit, it is fairly straightforward.
import urllib, urlib2, base64, json
# Housekeeping
token_url = 'http://localhost:8000/auth/token/'
data = urllib.urlencode({'grant_type':'password', 'username':<username>, 'password':<password>})
authentication = base64.b64encode('%s:%s' % (<client_id>, <client_secret>))
# Down to Business
request = urllib2.Request(token_url, data)
request.add_header("Authorization", "Basic %s" % authentication)
access_credentials = urllib2.urlopen(request)
json_credentials = json.load(access_credentials)
I reiterate, I do not know if this is in bad practice and I have not looked into whether or not this causes any issues with Django. AFAIK this will do this trick (as it did for me).