make user_api compatible with HTTP basic auth

lms/djangoapps/user_api/tests/test_views.py

+import base64
+
 from django.contrib.auth.models import User
 from django.test import TestCase
 from django.test.utils import override_settings
@@ -31,6 +33,9 @@ class UserApiTestCase(TestCase):
             UserPreferenceFactory.create(user=self.users[1], key="key0")
         ]
 
+    def basic_auth(self, username, password):
+        return {'HTTP_AUTHORIZATION': 'Basic ' + base64.b64encode('%s:%s' % (username, password))}
+
     def request_with_auth(self, method, *args, **kwargs):
         """Issue a get request to the given URI with the API key header"""
         return getattr(self.client, method)(*args, HTTP_X_EDX_API_KEY=TEST_API_KEY, **kwargs)
@@ -127,6 +132,15 @@ class UserViewSetTest(UserApiTestCase):
     def test_debug_auth(self):
         self.assertHttpOK(self.client.get(self.LIST_URI))
 
+    @override_settings(DEBUG=False)
+    @override_settings(EDX_API_KEY=TEST_API_KEY)
+    def test_basic_auth(self):
+        # ensure that having basic auth headers in the mix does not break anything
+        self.assertHttpOK(
+                self.request_with_auth("get", self.LIST_URI, **self.basic_auth('someuser', 'somepass')))
+        self.assertHttpForbidden(
+                self.client.get(self.LIST_URI, **self.basic_auth('someuser', 'somepass')))
+
     def test_get_list_empty(self):
         User.objects.all().delete()
         result = self.get_json(self.LIST_URI)

lms/djangoapps/user_api/views.py

 from django.conf import settings
 from django.contrib.auth.models import User
+from rest_framework import authentication
 from rest_framework import filters
 from rest_framework import permissions
 from rest_framework import viewsets
@@ -25,6 +26,7 @@ class ApiKeyHeaderPermission(permissions.BasePermission):
 
 
 class UserViewSet(viewsets.ReadOnlyModelViewSet):
+    authentication_classes = (authentication.SessionAuthentication,)
     permission_classes = (ApiKeyHeaderPermission,)
     queryset = User.objects.all()
     serializer_class = UserSerializer
@@ -33,6 +35,7 @@ class UserViewSet(viewsets.ReadOnlyModelViewSet):
 
 
 class UserPreferenceViewSet(viewsets.ReadOnlyModelViewSet):
+    authentication_classes = (authentication.SessionAuthentication,)
     permission_classes = (ApiKeyHeaderPermission,)
     queryset = UserPreference.objects.all()
     filter_backends = (filters.DjangoFilterBackend,)