6 files changed, 274 insertions, 4 deletions

diff --git a/docs/api-guide/authentication.md b/docs/api-guide/authentication.md
index fae86386..6a259500 100644
--- a/docs/api-guide/authentication.md
+++ b/docs/api-guide/authentication.md
@@ -182,6 +182,74 @@ Unauthenticated responses that are denied permission will result in an `HTTP 403
 
 If you're using an AJAX style API with SessionAuthentication, you'll need to make sure you include a valid CSRF token for any "unsafe" HTTP method calls, such as `PUT`, `PATCH`, `POST` or `DELETE` requests.  See the [Django CSRF documentation][csrf-ajax] for more details.
 
+## OAuth2Authentication
+
+This authentication uses [OAuth 2.0][rfc6749] authentication scheme. It depends on optional [`django-oauth2-provider`](https://github.com/caffeinehit/django-oauth2-provider). In order to make it work you must install this package and add `provider` and `provider.oauth2` to your `INSTALLED_APPS` :
+
+    INSTALLED_APPS = (
+        #(...)
+        'provider',
+        'provider.oauth2',
+    )
+
+And include the urls needed in your root `urls.py` file to be able to begin the *oauth 2 dance* :
+
+    url(r'^oauth2/', include('provider.oauth2.urls', namespace = 'oauth2')),
+
+---
+
+** Note:** The *namespace* argument is required !
+
+---
+
+Finally, sync your database with those two new django apps.
+
+    $ python manage.py syncdb
+    $ python manage.py migrate 
+
+`OAuth2Authentication` class provides only token verification for requests. The *oauth 2 dance* is taken care by the [`django-oaut2-provider`](https://github.com/caffeinehit/django-oauth2-provider) dependency. Unfortunately, there isn't a lot of [documentation](https://django-oauth2-provider.readthedocs.org/en/latest/) currently on how to *dance* with this package on the client side. 
+
+The Good news is, here is a minimal "How to start" because **OAuth 2** is dramatically simpler than **OAuth 1**, so no more headache with signature, cryptography on client side, and other complex things.
+
+### How to start with *django-oauth2-provider* ?
+
+#### Create a client in the django-admin panel
+
+Go to the admin panel and create a new `Provider.Client` entry. It will create the `client_id` and `client_secret` properties for you.
+
+#### Request an access token
+
+Your client interface – I mean by that your iOS code, HTML code, or whatever else language – just have to submit a `POST` request at the url `/oauth2/access_token` with the following fields :
+
+* `client_id` the client id you've just configured at the previous step.
+* `client_secret` again configured at the previous step.
+* `username` the username with which you want to log in.
+* `password` well, that speaks for itself.
+
+---
+
+**Note:** Remember that you are **highly encourage** to use HTTPS for all your OAuth 2 requests. And by *highly encourage* I mean you SHOULD always use HTTPS otherwise you will expose user passwords for any person who can intercept the request (like a man in the middle attack).
+
+---
+
+You can use the command line to test that your local configuration is working :
+
+    $ curl -X POST -d "client_id=YOUR_CLIENT_ID&client_secret=YOUR_CLIENT_SECRET&grant_type=password&username=YOUR_USERNAME&password=YOU_PASSWORD" http://localhost:8000/oauth2/access_token/
+
+Here is the response you should get :
+
+    {"access_token": "<your-access-token>", "scope": "read", "expires_in": 86399, "refresh_token": "<your-refresh-token>"}
+
+#### Access the api
+
+The only thing needed to make the `OAuth2Authentication` class work is to insert the `access_token` you've received in the `Authorization` api request header.
+
+The command line to test the authentication looks like :
+
+    $ curl -H "Authorization: Bearer <your-access-token>" http://localhost:8000/api/?client_id=YOUR_CLIENT_ID\&client_secret=YOUR_CLIENT_SECRET
+
+And hopefully, it will work like a charm.
+
 # Custom authentication
 
 To implement a custom authentication scheme, subclass `BaseAuthentication` and override the `.authenticate(self, request)` method.  The method should return a two-tuple of `(user, auth)` if authentication succeeds, or `None` otherwise.
@@ -235,3 +303,4 @@ HTTP digest authentication is a widely implemented scheme that was intended to r
 [mod_wsgi_official]: http://code.google.com/p/modwsgi/wiki/ConfigurationDirectives#WSGIPassAuthorization
 [juanriaza]: https://github.com/juanriaza
 [djangorestframework-digestauth]: https://github.com/juanriaza/django-rest-framework-digestauth
+[rfc6749]: http://tools.ietf.org/html/rfc6749
diff --git a/optionals.txt b/optionals.txt
index 3d98cc0e..a36e9e94 100644
--- a/optionals.txt
+++ b/optionals.txt
@@ -2,3 +2,4 @@ markdown>=2.1.0
 PyYAML>=3.10
 defusedxml>=0.3
 django-filter>=0.5.4
+-e git+git://github.com/caffeinehit/django-oauth2-provider.git@3198060acfe14730ce2d81310cbf2b13f6403438#egg=django_oauth2_provider-dev
\ No newline at end of file
diff --git a/rest_framework/authentication.py b/rest_framework/authentication.py
index 14b2136b..c20d9cb5 100644
--- a/rest_framework/authentication.py
+++ b/rest_framework/authentication.py
@@ -6,6 +6,7 @@ from django.contrib.auth import authenticate
 from django.utils.encoding import DjangoUnicodeDecodeError
 from rest_framework import exceptions, HTTP_HEADER_ENCODING
 from rest_framework.compat import CsrfViewMiddleware
+from rest_framework.compat import oauth2_provider, oauth2
 from rest_framework.authtoken.models import Token
 import base64
 
@@ -155,4 +156,86 @@ class TokenAuthentication(BaseAuthentication):
         return 'Token'
 
 
-# TODO: OAuthAuthentication
+class OAuth2Authentication(BaseAuthentication):
+    """
+    OAuth 2 authentication backend using `django-oauth2-provider`
+    """
+    require_active = True
+
+    def __init__(self, **kwargs):
+        super(OAuth2Authentication, self).__init__(**kwargs)
+        if oauth2_provider is None:
+            raise ImproperlyConfigured("The 'django-oauth2-provider' package could not be imported. It is required for use with the 'OAuth2Authentication' class.")
+
+    def authenticate(self, request):
+        """
+        The Bearer type is the only finalized type
+
+        Read the spec for more details
+        http://tools.ietf.org/html/rfc6749#section-7.1
+        """
+        auth = request.META.get('HTTP_AUTHORIZATION', '').split()
+        print auth
+        if not auth or auth[0].lower() != "bearer":
+            return None
+
+        if len(auth) != 2:
+            raise exceptions.AuthenticationFailed('Invalid token header')
+
+        return self.authenticate_credentials(request, auth[1])
+
+    def authenticate_credentials(self, request, access_token):
+        """
+        :returns: two-tuple of (user, auth) if authentication succeeds, or None otherwise.
+        """
+
+        # authenticate the client
+        oauth2_client_form = oauth2.forms.ClientAuthForm(request.REQUEST)
+        if not oauth2_client_form.is_valid():
+            raise exceptions.AuthenticationFailed("Client could not be validated")
+        client = oauth2_client_form.cleaned_data.get('client')
+
+        # retrieve the `oauth2.models.OAuth2AccessToken` instance from the access_token
+        auth_backend = oauth2.backends.AccessTokenBackend()
+        token = auth_backend.authenticate(access_token, client)
+        if token is None:
+            raise exceptions.AuthenticationFailed("Invalid token")  # does not exist or is expired
+
+        # TODO check scope
+        # try:
+        #     self.validate_token(request, consumer, token)
+        # except oauth2.Error, e:
+        #     print "got e"
+        #     raise exceptions.AuthenticationFailed(e.message)
+
+        if not self.check_active(token.user):
+            raise exceptions.AuthenticationFailed('User not active: %s' % token.user.username)
+
+        if client and token:
+            request.user = token.user
+            return (request.user, None)
+
+        raise exceptions.AuthenticationFailed(
+            'You are not allowed to access this resource.')
+
+        return None
+
+    def authenticate_header(self, request):
+        """
+        Bearer is the only finalized type currently 
+
+        Check details on the `OAuth2Authentication.authenticate` method
+        """
+        return 'Bearer'
+
+    def check_active(self, user):
+        """
+        Ensures the user has an active account.
+
+        Optimized for the ``django.contrib.auth.models.User`` case.
+        """
+        if not self.require_active:
+            # Ignore & move on.
+            return True
+
+        return user.is_active
diff --git a/rest_framework/compat.py b/rest_framework/compat.py
index 07fdddce..5bba0c86 100644
--- a/rest_framework/compat.py
+++ b/rest_framework/compat.py
@@ -426,3 +426,14 @@ try:
     import defusedxml.ElementTree as etree
 except ImportError:
     etree = None
+
+
+# OAuth 2 support is optional
+try:
+    import provider as oauth2_provider
+except ImportError:
+    oauth2_provider = None
+try:
+    import provider.oauth2 as oauth2
+except ImportError:
+    oauth2 = None
diff --git a/rest_framework/runtests/settings.py b/rest_framework/runtests/settings.py
index 03bfc216..67dc7fff 100644
--- a/rest_framework/runtests/settings.py
+++ b/rest_framework/runtests/settings.py
@@ -97,7 +97,9 @@ INSTALLED_APPS = (
     # 'django.contrib.admindocs',
     'rest_framework',
     'rest_framework.authtoken',
-    'rest_framework.tests'
+    'rest_framework.tests',
+    'provider',
+    'provider.oauth2',
 )
 
 STATIC_URL = '/static/'
diff --git a/rest_framework/tests/authentication.py b/rest_framework/tests/authentication.py
index 7b754af5..c2c23bcc 100644
--- a/rest_framework/tests/authentication.py
+++ b/rest_framework/tests/authentication.py
@@ -1,4 +1,5 @@
 from __future__ import unicode_literals
+from django.core.urlresolvers import reverse
 from django.contrib.auth.models import User
 from django.http import HttpResponse
 from django.test import Client, TestCase
@@ -11,13 +12,18 @@ from rest_framework.authentication import (
     BaseAuthentication,
     TokenAuthentication,
     BasicAuthentication,
-    SessionAuthentication
+    SessionAuthentication,
+    OAuth2Authentication
 )
-from rest_framework.compat import patterns
+from rest_framework.compat import patterns, url, include
+from rest_framework.compat import oauth2
+from rest_framework.compat import oauth2_provider
 from rest_framework.tests.utils import RequestFactory
 from rest_framework.views import APIView
 import json
 import base64
+import datetime
+import unittest
 
 
 factory = RequestFactory()
@@ -41,6 +47,8 @@ urlpatterns = patterns('',
     (r'^basic/$', MockView.as_view(authentication_classes=[BasicAuthentication])),
     (r'^token/$', MockView.as_view(authentication_classes=[TokenAuthentication])),
     (r'^auth-token/$', 'rest_framework.authtoken.views.obtain_auth_token'),
+    url(r'^oauth2/', include('provider.oauth2.urls', namespace = 'oauth2')),
+    url(r'^oauth2-test/$', MockView.as_view(authentication_classes=[OAuth2Authentication])),
 )
 
 
@@ -222,3 +230,99 @@ class IncorrectCredentialsTests(TestCase):
         response = view(request)
         self.assertEqual(response.status_code, status.HTTP_403_FORBIDDEN)
         self.assertEqual(response.data, {'detail': 'Bad credentials'})
+
+
+class OAuth2Tests(TestCase):
+    """OAuth 2.0 authentication"""
+    urls = 'rest_framework.tests.authentication'
+
+    def setUp(self):
+        self.csrf_client = Client(enforce_csrf_checks=True)
+        self.username = 'john'
+        self.email = 'lennon@thebeatles.com'
+        self.password = 'password'
+        self.user = User.objects.create_user(self.username, self.email, self.password)
+
+        self.CLIENT_ID = 'client_key'
+        self.CLIENT_SECRET = 'client_secret'
+        self.ACCESS_TOKEN = "access_token"
+        self.REFRESH_TOKEN = "refresh_token"
+
+        self.oauth2_client = oauth2.models.Client.objects.create(
+                client_id=self.CLIENT_ID, 
+                client_secret=self.CLIENT_SECRET,
+                redirect_uri='',
+                client_type=0,
+                name='example', 
+                user=None,
+            )
+
+        self.access_token = oauth2.models.AccessToken.objects.create(
+                token=self.ACCESS_TOKEN,
+                client=self.oauth2_client,
+                user=self.user,
+            )
+        self.refresh_token = oauth2.models.RefreshToken.objects.create(
+                user=self.user,
+                access_token=self.access_token,
+                client=self.oauth2_client
+            )
+
+    def _create_authorization_header(self, token=None):
+        return "Bearer {0}".format(token or self.access_token.token)
+
+    def _client_credentials_params(self):
+        return {'client_id': self.CLIENT_ID, 'client_secret': self.CLIENT_SECRET}
+
+    @unittest.skipUnless(oauth2, 'django-oauth2-provider not installed')
+    def test_get_form_with_wrong_client_data_failing_auth(self):
+        """Ensure GETing form over OAuth with incorrect client credentials fails"""
+        auth = self._create_authorization_header()
+        params = self._client_credentials_params()
+        params['client_id'] += 'a'
+        response = self.csrf_client.get('/oauth2-test/', params, HTTP_AUTHORIZATION=auth)
+        self.assertEqual(response.status_code, 401)
+
+    @unittest.skipUnless(oauth2, 'django-oauth2-provider not installed')
+    def test_get_form_passing_auth(self):
+        """Ensure GETing form over OAuth with correct client credentials succeed"""
+        auth = self._create_authorization_header()
+        params = self._client_credentials_params()
+        response = self.csrf_client.get('/oauth2-test/', params, HTTP_AUTHORIZATION=auth)
+        self.assertEqual(response.status_code, 200)
+
+    @unittest.skipUnless(oauth2, '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()
+        params = self._client_credentials_params()
+        response = self.csrf_client.post('/oauth2-test/', params, HTTP_AUTHORIZATION=auth)
+        self.assertEqual(response.status_code, 200)
+
+    @unittest.skipUnless(oauth2, 'django-oauth2-provider not installed')
+    def test_post_form_token_removed_failing_auth(self):
+        """Ensure POSTing when there is no OAuth access token in db fails"""
+        self.access_token.delete()
+        auth = self._create_authorization_header()
+        params = self._client_credentials_params()
+        response = self.csrf_client.post('/oauth2-test/', params, HTTP_AUTHORIZATION=auth)
+        self.assertIn(response.status_code, (status.HTTP_401_UNAUTHORIZED, status.HTTP_403_FORBIDDEN))
+
+    @unittest.skipUnless(oauth2, 'django-oauth2-provider not installed')
+    def test_post_form_with_refresh_token_failing_auth(self):
+        """Ensure POSTing with refresh token instead of access token fails"""
+        auth = self._create_authorization_header(token=self.refresh_token.token)
+        params = self._client_credentials_params()
+        response = self.csrf_client.post('/oauth2-test/', params, HTTP_AUTHORIZATION=auth)
+        self.assertIn(response.status_code, (status.HTTP_401_UNAUTHORIZED, status.HTTP_403_FORBIDDEN))
+
+    @unittest.skipUnless(oauth2, 'django-oauth2-provider not installed')
+    def test_post_form_with_expired_access_token_failing_auth(self):
+        """Ensure POSTing with expired access token fails with an 'Invalid token' error"""
+        self.access_token.expires = datetime.datetime.now() - datetime.timedelta(seconds=10)  # 10 seconds late
+        self.access_token.save()
+        auth = self._create_authorization_header()
+        params = self._client_credentials_params()
+        response = self.csrf_client.post('/oauth2-test/', params, HTTP_AUTHORIZATION=auth)
+        self.assertIn(response.status_code, (status.HTTP_401_UNAUTHORIZED, status.HTTP_403_FORBIDDEN))
+        self.assertIn('Invalid token', response.content)