From 0e5faf225c5cd1acf2ab653c74f5b161470403b9 Mon Sep 17 00:00:00 2001
From: Jacob Kaplan-Moss <jacob@jacobian.org>
Date: Tue, 2 Sep 2008 21:10:00 +0000
Subject: [PATCH] Security fix. Announcement forthcoming.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@8877 bcc190cf-cafb-0310-a4f2-bffc1f526a37
---
 django/contrib/admin/sites.py                 | 37 +------------
 .../contrib/admin/templates/admin/login.html  |  1 -
 django/contrib/admin/views/decorators.py      | 41 +--------------
 tests/regressiontests/admin_views/tests.py    | 52 ++++++-------------
 4 files changed, 19 insertions(+), 112 deletions(-)

diff --git a/django/contrib/admin/sites.py b/django/contrib/admin/sites.py
index dd35a03656..0be93a20c3 100644
--- a/django/contrib/admin/sites.py
+++ b/django/contrib/admin/sites.py
@@ -1,7 +1,5 @@
 import base64
-import cPickle as pickle
 import re
-
 from django import http, template
 from django.contrib.admin import ModelAdmin
 from django.contrib.auth import authenticate, login
@@ -24,19 +22,6 @@ class AlreadyRegistered(Exception):
 class NotRegistered(Exception):
     pass
 
-def _encode_post_data(post_data):
-    pickled = pickle.dumps(post_data)
-    pickled_md5 = md5_constructor(pickled + settings.SECRET_KEY).hexdigest()
-    return base64.encodestring(pickled + pickled_md5)
-
-def _decode_post_data(encoded_data):
-    encoded_data = base64.decodestring(encoded_data)
-    pickled, tamper_check = encoded_data[:-32], encoded_data[-32:]
-    if md5_constructor(pickled + settings.SECRET_KEY).hexdigest() != tamper_check:
-        from django.core.exceptions import SuspiciousOperation
-        raise SuspiciousOperation, "User may have tampered with session cookie."
-    return pickle.loads(pickled)
-
 class AdminSite(object):
     """
     An AdminSite object encapsulates an instance of the Django admin application, ready
@@ -239,7 +224,7 @@ class AdminSite(object):
         # If this isn't already the login page, display it.
         if not request.POST.has_key(LOGIN_FORM_KEY):
             if request.POST:
-                message = _("Please log in again, because your session has expired. Don't worry: Your submission has been saved.")
+                message = _("Please log in again, because your session has expired.")
             else:
                 message = ""
             return self.display_login_form(request, message)
@@ -275,15 +260,7 @@ class AdminSite(object):
         else:
             if user.is_active and user.is_staff:
                 login(request, user)
-                if request.POST.has_key('post_data'):
-                    post_data = _decode_post_data(request.POST['post_data'])
-                    if post_data and not post_data.has_key(LOGIN_FORM_KEY):
-                        # overwrite request.POST with the saved post_data, and continue
-                        request.POST = post_data
-                        request.user = user
-                        return self.root(request, request.path.split(self.root_path)[-1])
-                    else:
-                        return http.HttpResponseRedirect(request.get_full_path())
+                return http.HttpResponseRedirect(request.get_full_path())
             else:
                 return self.display_login_form(request, ERROR_MESSAGE)
     login = never_cache(login)
@@ -345,19 +322,9 @@ class AdminSite(object):
 
     def display_login_form(self, request, error_message='', extra_context=None):
         request.session.set_test_cookie()
-        if request.POST and request.POST.has_key('post_data'):
-            # User has failed login BUT has previously saved post data.
-            post_data = request.POST['post_data']
-        elif request.POST:
-            # User's session must have expired; save their post data.
-            post_data = _encode_post_data(request.POST)
-        else:
-            post_data = _encode_post_data({})
-
         context = {
             'title': _('Log in'),
             'app_path': request.get_full_path(),
-            'post_data': post_data,
             'error_message': error_message,
             'root_path': self.root_path,
         }
diff --git a/django/contrib/admin/templates/admin/login.html b/django/contrib/admin/templates/admin/login.html
index 5dd953bc23..8c7603682b 100644
--- a/django/contrib/admin/templates/admin/login.html
+++ b/django/contrib/admin/templates/admin/login.html
@@ -21,7 +21,6 @@
   <div class="form-row">
     <label for="id_password">{% trans 'Password:' %}</label> <input type="password" name="password" id="id_password" />
     <input type="hidden" name="this_is_the_login_form" value="1" />
-    <input type="hidden" name="post_data" value="{{ post_data }}" /> {#<span class="help">{% trans 'Have you <a href="/password_reset/">forgotten your password</a>?' %}</span>#}
   </div>
   <div class="submit-row">
     <label>&nbsp;</label><input type="submit" value="{% trans 'Log in' %}" />
diff --git a/django/contrib/admin/views/decorators.py b/django/contrib/admin/views/decorators.py
index f3c63ff70c..4566828b0a 100644
--- a/django/contrib/admin/views/decorators.py
+++ b/django/contrib/admin/views/decorators.py
@@ -1,5 +1,4 @@
 import base64
-import cPickle as pickle
 try:
     from functools import wraps
 except ImportError:
@@ -11,41 +10,18 @@ from django.contrib.auth.models import User
 from django.contrib.auth import authenticate, login
 from django.shortcuts import render_to_response
 from django.utils.translation import ugettext_lazy, ugettext as _
-from django.utils.hashcompat import md5_constructor
 
 ERROR_MESSAGE = ugettext_lazy("Please enter a correct username and password. Note that both fields are case-sensitive.")
 LOGIN_FORM_KEY = 'this_is_the_login_form'
 
 def _display_login_form(request, error_message=''):
     request.session.set_test_cookie()
-    if request.POST and 'post_data' in request.POST:
-        # User has failed login BUT has previously saved post data.
-        post_data = request.POST['post_data']
-    elif request.POST:
-        # User's session must have expired; save their post data.
-        post_data = _encode_post_data(request.POST)
-    else:
-        post_data = _encode_post_data({})
     return render_to_response('admin/login.html', {
         'title': _('Log in'),
         'app_path': request.get_full_path(),
-        'post_data': post_data,
         'error_message': error_message
     }, context_instance=template.RequestContext(request))
 
-def _encode_post_data(post_data):
-    pickled = pickle.dumps(post_data)
-    pickled_md5 = md5_constructor(pickled + settings.SECRET_KEY).hexdigest()
-    return base64.encodestring(pickled + pickled_md5)
-
-def _decode_post_data(encoded_data):
-    encoded_data = base64.decodestring(encoded_data)
-    pickled, tamper_check = encoded_data[:-32], encoded_data[-32:]
-    if md5_constructor(pickled + settings.SECRET_KEY).hexdigest() != tamper_check:
-        from django.core.exceptions import SuspiciousOperation
-        raise SuspiciousOperation, "User may have tampered with session cookie."
-    return pickle.loads(pickled)
-
 def staff_member_required(view_func):
     """
     Decorator for views that checks that the user is logged in and is a staff
@@ -54,10 +30,6 @@ def staff_member_required(view_func):
     def _checklogin(request, *args, **kwargs):
         if request.user.is_authenticated() and request.user.is_staff:
             # The user is valid. Continue to the admin page.
-            if 'post_data' in request.POST:
-                # User must have re-authenticated through a different window
-                # or tab.
-                request.POST = _decode_post_data(request.POST['post_data'])
             return view_func(request, *args, **kwargs)
 
         assert hasattr(request, 'session'), "The Django admin requires session middleware to be installed. Edit your MIDDLEWARE_CLASSES setting to insert 'django.contrib.sessions.middleware.SessionMiddleware'."
@@ -65,7 +37,7 @@ def staff_member_required(view_func):
         # If this isn't already the login page, display it.
         if LOGIN_FORM_KEY not in request.POST:
             if request.POST:
-                message = _("Please log in again, because your session has expired. Don't worry: Your submission has been saved.")
+                message = _("Please log in again, because your session has expired.")
             else:
                 message = ""
             return _display_login_form(request, message)
@@ -98,16 +70,7 @@ def staff_member_required(view_func):
         else:
             if user.is_active and user.is_staff:
                 login(request, user)
-                # TODO: set last_login with an event.
-                if 'post_data' in request.POST:
-                    post_data = _decode_post_data(request.POST['post_data'])
-                    if post_data and LOGIN_FORM_KEY not in post_data:
-                        # overwrite request.POST with the saved post_data, and continue
-                        request.POST = post_data
-                        request.user = user
-                        return view_func(request, *args, **kwargs)
-                    else:
-                        return http.HttpResponseRedirect(request.get_full_path())
+                return http.HttpResponseRedirect(request.get_full_path())
             else:
                 return _display_login_form(request, ERROR_MESSAGE)
 
diff --git a/tests/regressiontests/admin_views/tests.py b/tests/regressiontests/admin_views/tests.py
index 56937d8462..5a10971570 100644
--- a/tests/regressiontests/admin_views/tests.py
+++ b/tests/regressiontests/admin_views/tests.py
@@ -4,7 +4,7 @@ from django.test import TestCase
 from django.contrib.auth.models import User, Permission
 from django.contrib.contenttypes.models import ContentType
 from django.contrib.admin.models import LogEntry
-from django.contrib.admin.sites import LOGIN_FORM_KEY, _encode_post_data
+from django.contrib.admin.sites import LOGIN_FORM_KEY
 from django.contrib.admin.util import quote
 from django.utils.html import escape
 
@@ -136,31 +136,31 @@ class AdminViewPermissionsTest(TestCase):
             Section._meta.get_delete_permission()))
 
         # login POST dicts
-        self.super_login = {'post_data': _encode_post_data({}),
+        self.super_login = {
                      LOGIN_FORM_KEY: 1,
                      'username': 'super',
                      'password': 'secret'}
-        self.super_email_login = {'post_data': _encode_post_data({}),
+        self.super_email_login = {
                      LOGIN_FORM_KEY: 1,
                      'username': 'super@example.com',
                      'password': 'secret'}
-        self.super_email_bad_login = {'post_data': _encode_post_data({}),
+        self.super_email_bad_login = {
                       LOGIN_FORM_KEY: 1,
                       'username': 'super@example.com',
                       'password': 'notsecret'}
-        self.adduser_login = {'post_data': _encode_post_data({}),
+        self.adduser_login = {
                      LOGIN_FORM_KEY: 1,
                      'username': 'adduser',
                      'password': 'secret'}
-        self.changeuser_login = {'post_data': _encode_post_data({}),
+        self.changeuser_login = {
                      LOGIN_FORM_KEY: 1,
                      'username': 'changeuser',
                      'password': 'secret'}
-        self.deleteuser_login = {'post_data': _encode_post_data({}),
+        self.deleteuser_login = {
                      LOGIN_FORM_KEY: 1,
                      'username': 'deleteuser',
                      'password': 'secret'}
-        self.joepublic_login = {'post_data': _encode_post_data({}),
+        self.joepublic_login = {
                      LOGIN_FORM_KEY: 1,
                      'username': 'joepublic',
                      'password': 'secret'}
@@ -271,17 +271,6 @@ class AdminViewPermissionsTest(TestCase):
         self.failUnlessEqual(Article.objects.all().count(), 3)
         self.client.get('/test_admin/admin/logout/')
 
-        # Check and make sure that if user expires, data still persists
-        post = self.client.post('/test_admin/admin/admin_views/article/add/', add_dict)
-        self.assertContains(post, 'Please log in again, because your session has expired.')
-        self.super_login['post_data'] = _encode_post_data(add_dict)
-        post = self.client.post('/test_admin/admin/admin_views/article/add/', self.super_login)
-        # make sure the view removes test cookie
-        self.failUnlessEqual(self.client.session.test_cookie_worked(), False)
-        self.assertRedirects(post, '/test_admin/admin/admin_views/article/')
-        self.failUnlessEqual(Article.objects.all().count(), 4)
-        self.client.get('/test_admin/admin/logout/')
-
         # 8509 - if a normal user is already logged in, it is possible
         # to change user into the superuser without error
         login = self.client.login(username='joepublic', password='secret')
@@ -489,31 +478,31 @@ class SecureViewTest(TestCase):
 
     def setUp(self):
         # login POST dicts
-        self.super_login = {'post_data': _encode_post_data({}),
+        self.super_login = {
                      LOGIN_FORM_KEY: 1,
                      'username': 'super',
                      'password': 'secret'}
-        self.super_email_login = {'post_data': _encode_post_data({}),
+        self.super_email_login = {
                      LOGIN_FORM_KEY: 1,
                      'username': 'super@example.com',
                      'password': 'secret'}
-        self.super_email_bad_login = {'post_data': _encode_post_data({}),
+        self.super_email_bad_login = {
                       LOGIN_FORM_KEY: 1,
                       'username': 'super@example.com',
                       'password': 'notsecret'}
-        self.adduser_login = {'post_data': _encode_post_data({}),
+        self.adduser_login = {
                      LOGIN_FORM_KEY: 1,
                      'username': 'adduser',
                      'password': 'secret'}
-        self.changeuser_login = {'post_data': _encode_post_data({}),
+        self.changeuser_login = {
                      LOGIN_FORM_KEY: 1,
                      'username': 'changeuser',
                      'password': 'secret'}
-        self.deleteuser_login = {'post_data': _encode_post_data({}),
+        self.deleteuser_login = {
                      LOGIN_FORM_KEY: 1,
                      'username': 'deleteuser',
                      'password': 'secret'}
-        self.joepublic_login = {'post_data': _encode_post_data({}),
+        self.joepublic_login = {
                      LOGIN_FORM_KEY: 1,
                      'username': 'joepublic',
                      'password': 'secret'}
@@ -597,17 +586,6 @@ class SecureViewTest(TestCase):
         # Login.context is a list of context dicts we just need to check the first one.
         self.assert_(login.context[0].get('error_message'))
 
-        # Check and make sure that if user expires, data still persists
-        data = {'foo': 'bar'}
-        post = self.client.post('/test_admin/admin/secure-view/', data)
-        self.assertContains(post, 'Please log in again, because your session has expired.')
-        self.super_login['post_data'] = _encode_post_data(data)
-        post = self.client.post('/test_admin/admin/secure-view/', self.super_login)
-        # make sure the view removes test cookie
-        self.failUnlessEqual(self.client.session.test_cookie_worked(), False)
-        self.assertContains(post, "{'foo': 'bar'}")
-        self.client.get('/test_admin/admin/logout/')
-                
         # 8509 - if a normal user is already logged in, it is possible
         # to change user into the superuser without error
         login = self.client.login(username='joepublic', password='secret')