From ece77cd6bb70c1214dd1d5d7b32d287a30d729eb Mon Sep 17 00:00:00 2001
From: Andrzej Pragacz <apragacz@o2.pl>
Date: Sun, 25 Aug 2019 17:49:05 +0200
Subject: [PATCH] Fix issue #65

* Add SessionCSRFAuthentication
---
 rest_registration/api/authentication.py |  9 ++++++
 tests/api/test_login.py                 | 43 ++++++++++++++++---------
 tests/helpers.py                        | 27 ++++++++++++++++
 3 files changed, 64 insertions(+), 15 deletions(-)
 create mode 100644 rest_registration/api/authentication.py
 create mode 100644 tests/helpers.py

diff --git a/rest_registration/api/authentication.py b/rest_registration/api/authentication.py
new file mode 100644
index 0000000..e36a5ea
--- /dev/null
+++ b/rest_registration/api/authentication.py
@@ -0,0 +1,9 @@
+from rest_framework.authentication import SessionAuthentication
+
+
+class SessionCSRFAuthentication(SessionAuthentication):
+
+    def authenticate(self, request):
+        user = getattr(request._request, 'user', None)  # noqa: E501 pylint: disable=protected-access
+        self.enforce_csrf(request)
+        return (user, None)
diff --git a/tests/api/test_login.py b/tests/api/test_login.py
index 532941f..443a77f 100644
--- a/tests/api/test_login.py
+++ b/tests/api/test_login.py
@@ -1,8 +1,9 @@
 from django.test.utils import modify_settings, override_settings
 from rest_framework import status
 from rest_framework.authtoken.models import Token
-from rest_framework.test import force_authenticate
+from rest_framework.test import APIRequestFactory, force_authenticate
 
+from ..helpers import override_rest_framework_settings_dict
 from .base import APIViewTestCase
 
 
@@ -53,6 +54,22 @@ def test_invalid(self):
         response = self.view_func(request)
         self.assert_invalid_response(response, status.HTTP_400_BAD_REQUEST)
 
+    @override_rest_framework_settings_dict({
+        'DEFAULT_AUTHENTICATION_CLASSES': [
+            'rest_registration.api.authentication.SessionCSRFAuthentication',
+        ],
+    })
+    def test_csrf(self):
+        factory = APIRequestFactory(enforce_csrf_checks=True)
+        request = factory.post("/login", {
+            'login': self.user.username,
+            'password': self.password,
+        })
+        self.add_session_to_request(request)
+        response = self.view_func(request)
+        self.assert_invalid_response(
+            response, status.HTTP_403_FORBIDDEN)
+
 
 class LogoutViewTestCase(BaseLoginTestCase):
     VIEW_NAME = 'logout'
@@ -77,13 +94,11 @@ def test_revoke_token_success(self):
             'remove': 'django.contrib.sessions.middleware.SessionMiddleware',
         }
     )
-    @override_settings(
-        REST_FRAMEWORK={
-            'DEFAULT_AUTHENTICATION_CLASSES': (
-                'rest_framework.authentication.TokenAuthentication',
-            ),
-        },
-    )
+    @override_rest_framework_settings_dict({
+        'DEFAULT_AUTHENTICATION_CLASSES': (
+            'rest_framework.authentication.TokenAuthentication',
+        ),
+    })
     def test_revoke_token_success_without_session(self):
         self._test_revoke_token_success(add_session=False)
 
@@ -112,13 +127,11 @@ def test_revoke_nonexistent_token_failure(self):
             'remove': 'django.contrib.sessions.middleware.SessionMiddleware',
         }
     )
-    @override_settings(
-        REST_FRAMEWORK={
-            'DEFAULT_AUTHENTICATION_CLASSES': (
-                'rest_framework.authentication.TokenAuthentication',
-            ),
-        },
-    )
+    @override_rest_framework_settings_dict({
+        'DEFAULT_AUTHENTICATION_CLASSES': (
+            'rest_framework.authentication.TokenAuthentication',
+        ),
+    })
     def test_revoke_nonexistent_token_failure_without_session(self):
         self._test_revoke_nonexistent_token_failure(add_session=False)
 
diff --git a/tests/helpers.py b/tests/helpers.py
new file mode 100644
index 0000000..bcabb72
--- /dev/null
+++ b/tests/helpers.py
@@ -0,0 +1,27 @@
+import contextlib
+
+from django.test.utils import override_settings
+from rest_framework.settings import api_settings
+from rest_framework.views import APIView
+
+
+@contextlib.contextmanager
+def override_rest_framework_settings_dict(settings_dict):
+    try:
+        with override_settings(REST_FRAMEWORK=settings_dict):
+            _update_api_view_class_attrs()
+            yield
+    finally:
+        _update_api_view_class_attrs()
+
+
+def _update_api_view_class_attrs():
+    attrs = [
+        'renderer_classes', 'parser_classes', 'authentication_classes',
+        'throttle_classes', 'permission_classes', 'content_negotiation_class',
+        'metadata_class', 'versioning_class',
+    ]
+    for attr in attrs:
+        attr_upper = attr.upper()
+        api_settings_key = 'DEFAULT_{attr_upper}'.format(attr_upper=attr_upper)
+        setattr(APIView, attr, getattr(api_settings, api_settings_key))