Fixed #11223 -- Fixed logout view to use the 'next' GET parameter correctly as described in the docs, while only allowing redirection to the same host.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@15706 bcc190cf-cafb-0310-a4f2-bffc1f526a37

django/contrib/auth/tests/views.py

@@ -333,6 +333,19 @@ class LogoutTest(AuthViewsTestCase):
         response = self.client.get('/logout/')
         self.assertTrue('site' in response.context)
 
+    def test_logout_with_overridden_redirect_url(self):
+        # Bug 11223
+        self.login()
+        response = self.client.get('/logout/next_page/')
+        self.assertEqual(response.status_code, 302)
+        self.assert_(response['Location'].endswith('/somewhere/'))
+
+        response = self.client.get('/logout/next_page/?next=/login/')
+        self.assertEqual(response.status_code, 302)
+        self.assert_(response['Location'].endswith('/login/'))
+
+        self.confirm_logged_out()
+
     def test_logout_with_next_page_specified(self): 
         "Logout with next_page option given redirects to specified resource"
         self.login()
@@ -356,3 +369,45 @@ class LogoutTest(AuthViewsTestCase):
         self.assertEqual(response.status_code, 302)
         self.assert_(response['Location'].endswith('/somewhere/'))
         self.confirm_logged_out()
+
+    def test_security_check(self, password='password'):
+        logout_url = reverse('django.contrib.auth.views.logout')
+
+        # Those URLs should not pass the security check
+        for bad_url in ('http://example.com',
+                        'https://example.com',
+                        'ftp://exampel.com',
+                        '//example.com'
+                        ):
+            nasty_url = '%(url)s?%(next)s=%(bad_url)s' % {
+                'url': logout_url,
+                'next': REDIRECT_FIELD_NAME,
+                'bad_url': urllib.quote(bad_url)
+            }
+            self.login()
+            response = self.client.get(nasty_url)
+            self.assertEquals(response.status_code, 302)
+            self.assertFalse(bad_url in response['Location'],
+                             "%s should be blocked" % bad_url)
+            self.confirm_logged_out()
+
+        # These URLs *should* still pass the security check
+        for good_url in ('/view/?param=http://example.com',
+                         '/view/?param=https://example.com',
+                         '/view?param=ftp://exampel.com',
+                         'view/?param=//example.com',
+                         'https:///',
+                         '//testserver/',
+                         '/url%20with%20spaces/', # see ticket #12534
+                         ):
+            safe_url = '%(url)s?%(next)s=%(good_url)s' % {
+                'url': logout_url,
+                'next': REDIRECT_FIELD_NAME,
+                'good_url': urllib.quote(good_url)
+            }
+            self.login()
+            response = self.client.get(safe_url)
+            self.assertEquals(response.status_code, 302)
+            self.assertTrue(good_url in response['Location'],
+                            "%s should be allowed" % good_url)
+            self.confirm_logged_out()

django/contrib/auth/views.py

@@ -1,23 +1,23 @@
-import re
 import urlparse
+
 from django.conf import settings
-from django.contrib.auth import REDIRECT_FIELD_NAME
-# Avoid shadowing the login() view below.
-from django.contrib.auth import login as auth_login
-from django.contrib.auth.decorators import login_required
-from django.contrib.auth.forms import AuthenticationForm
-from django.contrib.auth.forms import PasswordResetForm, SetPasswordForm, PasswordChangeForm
-from django.contrib.auth.tokens import default_token_generator
-from django.views.decorators.csrf import csrf_protect
 from django.core.urlresolvers import reverse
-from django.shortcuts import render_to_response, get_object_or_404
-from django.contrib.sites.models import get_current_site
-from django.http import HttpResponseRedirect, Http404, QueryDict
+from django.http import HttpResponseRedirect, QueryDict
+from django.shortcuts import render_to_response
 from django.template import RequestContext
 from django.utils.http import base36_to_int
 from django.utils.translation import ugettext as _
-from django.contrib.auth.models import User
 from django.views.decorators.cache import never_cache
+from django.views.decorators.csrf import csrf_protect
+
+# Avoid shadowing the login() and logout() views below.
+from django.contrib.auth import REDIRECT_FIELD_NAME, login as auth_login, logout as auth_logout
+from django.contrib.auth.decorators import login_required
+from django.contrib.auth.forms import AuthenticationForm, PasswordResetForm, SetPasswordForm, PasswordChangeForm
+from django.contrib.auth.models import User
+from django.contrib.auth.tokens import default_token_generator
+from django.contrib.sites.models import get_current_site
+
 
 @csrf_protect
 @never_cache
@@ -25,8 +25,9 @@ def login(request, template_name='registration/login.html',
           redirect_field_name=REDIRECT_FIELD_NAME,
           authentication_form=AuthenticationForm,
           current_app=None, extra_context=None):
-    """Displays the login form and handles the login action."""
-
+    """
+    Displays the login form and handles the login action.
+    """
     redirect_to = request.REQUEST.get(redirect_field_name, '')
 
     if request.method == "POST":
@@ -71,14 +72,18 @@ def logout(request, next_page=None,
            template_name='registration/logged_out.html',
            redirect_field_name=REDIRECT_FIELD_NAME,
            current_app=None, extra_context=None):
-    "Logs out the user and displays 'You are logged out' message."
-    from django.contrib.auth import logout
-    logout(request)
-    if next_page is None:
+    """
+    Logs out the user and displays 'You are logged out' message.
+    """
+    auth_logout(request)
     redirect_to = request.REQUEST.get(redirect_field_name, '')
     if redirect_to:
+        netloc = urlparse.urlparse(redirect_to)[1]
+        # Security check -- don't allow redirection to a different host.
+        if not (netloc and netloc != request.get_host()):
             return HttpResponseRedirect(redirect_to)
-        else:
+
+    if next_page is None:
         current_site = get_current_site(request)
         context = {
             'site': current_site,
@@ -93,14 +98,18 @@ def logout(request, next_page=None,
         return HttpResponseRedirect(next_page or request.path)
 
 def logout_then_login(request, login_url=None, current_app=None, extra_context=None):
-    "Logs out the user if he is logged in. Then redirects to the log-in page."
+    """
+    Logs out the user if he is logged in. Then redirects to the log-in page.
+    """
     if not login_url:
         login_url = settings.LOGIN_URL
     return logout(request, login_url, current_app=current_app, extra_context=extra_context)
 
 def redirect_to_login(next, login_url=None,
                       redirect_field_name=REDIRECT_FIELD_NAME):
-    "Redirects the user to the login page, passing the given 'next' page"
+    """
+    Redirects the user to the login page, passing the given 'next' page
+    """
     if not login_url:
         login_url = settings.LOGIN_URL