authentication: allow all transport modes of access token in OAuth2Authentication

RFC6750 describe three transport modes for access tokens when accessing a
protected resource:
- Auhthorization header with the Bearer authentication type
- form-encoded body parameter
- URI query parameter

This patch add support for last two transport modes.

rest_framework/authentication.py

@@ -6,6 +6,7 @@ import base64
 
 from django.contrib.auth import authenticate
 from django.core.exceptions import ImproperlyConfigured
+from django.conf import settings
 from rest_framework import exceptions, HTTP_HEADER_ENCODING
 from rest_framework.compat import CsrfViewMiddleware
 from rest_framework.compat import oauth, oauth_provider, oauth_provider_store
@@ -291,6 +292,7 @@ class OAuth2Authentication(BaseAuthentication):
     OAuth 2 authentication backend using `django-oauth2-provider`
     """
     www_authenticate_realm = 'api'
+    allow_query_params_token = settings.DEBUG
 
     def __init__(self, *args, **kwargs):
         super(OAuth2Authentication, self).__init__(*args, **kwargs)
@@ -308,7 +310,13 @@ class OAuth2Authentication(BaseAuthentication):
 
         auth = get_authorization_header(request).split()
 
-        if not auth or auth[0].lower() != b'bearer':
+        if auth and auth[0].lower() == b'bearer':
+            access_token = auth[1]
+        elif 'access_token' in request.POST:
+            access_token = request.POST['access_token']
+        elif 'access_token' in request.GET and self.allow_query_params_token:
+            access_token = request.GET['access_token']
+        else:
             return None
 
         if len(auth) == 1:
@@ -318,7 +326,7 @@ class OAuth2Authentication(BaseAuthentication):
             msg = 'Invalid bearer header. Token string should not contain spaces.'
             raise exceptions.AuthenticationFailed(msg)
 
-        return self.authenticate_credentials(request, auth[1])
+        return self.authenticate_credentials(request, access_token)
 
     def authenticate_credentials(self, request, access_token):
         """

rest_framework/tests/test_authentication.py

@@ -3,6 +3,7 @@ from django.contrib.auth.models import User
 from django.http import HttpResponse
 from django.test import TestCase
 from django.utils import unittest
+from django.utils.http import urlencode
 from rest_framework import HTTP_HEADER_ENCODING
 from rest_framework import exceptions
 from rest_framework import permissions
@@ -53,10 +54,14 @@ urlpatterns = patterns('',
         permission_classes=[permissions.TokenHasReadWriteScope]))
 )
 
+class OAuth2AuthenticationDebug(OAuth2Authentication):
+    allow_query_params_token = True
+
 if oauth2_provider is not None:
     urlpatterns += patterns('',
         url(r'^oauth2/', include('provider.oauth2.urls', namespace='oauth2')),
         url(r'^oauth2-test/$', MockView.as_view(authentication_classes=[OAuth2Authentication])),
+        url(r'^oauth2-test-debug/$', MockView.as_view(authentication_classes=[OAuth2AuthenticationDebug])),
         url(r'^oauth2-with-scope-test/$', MockView.as_view(authentication_classes=[OAuth2Authentication],
             permission_classes=[permissions.TokenHasReadWriteScope])),
     )
@@ -546,6 +551,27 @@ class OAuth2Tests(TestCase):
         self.assertEqual(response.status_code, 200)
 
     @unittest.skipUnless(oauth2_provider, 'django-oauth2-provider not installed')
+    def test_post_form_passing_auth_url_transport(self):
+        """Ensure GETing form over OAuth with correct client credentials in form data succeed"""
+        response = self.csrf_client.post('/oauth2-test/',
+                data={'access_token': self.access_token.token})
+        self.assertEqual(response.status_code, 200)
+
+    @unittest.skipUnless(oauth2_provider, 'django-oauth2-provider not installed')
+    def test_get_form_passing_auth_url_transport(self):
+        """Ensure GETing form over OAuth with correct client credentials in query succeed when DEBUG is True"""
+        query = urlencode({'access_token': self.access_token.token})
+        response = self.csrf_client.get('/oauth2-test-debug/?%s' % query)
+        self.assertEqual(response.status_code, 200)
+
+    @unittest.skipUnless(oauth2_provider, 'django-oauth2-provider not installed')
+    def test_get_form_failing_auth_url_transport(self):
+        """Ensure GETing form over OAuth with correct client credentials in query fails when DEBUG is False"""
+        query = urlencode({'access_token': self.access_token.token})
+        response = self.csrf_client.get('/oauth2-test/?%s' % query)
+        self.assertIn(response.status_code, (status.HTTP_401_UNAUTHORIZED, status.HTTP_403_FORBIDDEN))
+
+    @unittest.skipUnless(oauth2_provider, 'django-oauth2-provider not installed')
     def test_post_form_passing_auth(self):
         """Ensure POSTing form over OAuth with correct credentials passes and does not require CSRF"""
         auth = self._create_authorization_header()