django/docs/ref/clickjacking.txt

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========================
Clickjacking Protection
========================
.. module:: django.middleware.clickjacking
:synopsis: Protects against Clickjacking
The clickjacking middleware and decorators provide easy-to-use protection
against `clickjacking`_. This type of attack occurs when a malicious site
tricks a user into clicking on a concealed element of another site which they
have loaded in a hidden frame or iframe.
.. _clickjacking: http://en.wikipedia.org/wiki/Clickjacking
An example of clickjacking
==========================
Suppose an online store has a page where a logged in user can click "Buy Now" to
purchase an item. A user has chosen to stay logged into the store all the time
for convenience. An attacker site might create an "I Like Ponies" button on one
of their own pages, and load the store's page in a transparent iframe such that
the "Buy Now" button is invisibly overlaid on the "I Like Ponies" button. If the
user visits the attacker's site, clicking "I Like Ponies" will cause an
inadvertent click on the "Buy Now" button and an unknowing purchase of the item.
.. _clickjacking-prevention:
Preventing clickjacking
=======================
Modern browsers honor the `X-Frame-Options`_ HTTP header that indicates whether
or not a resource is allowed to load within a frame or iframe. If the response
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contains the header with a value of ``SAMEORIGIN`` then the browser will only
load the resource in a frame if the request originated from the same site. If
the header is set to ``DENY`` then the browser will block the resource from
loading in a frame no matter which site made the request.
.. _X-Frame-Options: https://developer.mozilla.org/en/The_X-FRAME-OPTIONS_response_header
Django provides a few simple ways to include this header in responses from your
site:
1. A simple middleware that sets the header in all responses.
2. A set of view decorators that can be used to override the middleware or to
only set the header for certain views.
How to use it
=============
Setting X-Frame-Options for all responses
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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To set the same ``X-Frame-Options`` value for all responses in your site, put
``'django.middleware.clickjacking.XFrameOptionsMiddleware'`` to
:setting:`MIDDLEWARE_CLASSES`::
MIDDLEWARE_CLASSES = (
...
'django.middleware.clickjacking.XFrameOptionsMiddleware',
...
)
This middleware is enabled in the settings file generated by
:djadmin:`startproject`.
Simplified default project template. Squashed commit of: commit 508ec9144b35c50794708225b496bde1eb5e60aa Author: Aymeric Augustin <aymeric.augustin@m4x.org> Date: Tue Jan 29 22:50:55 2013 +0100 Tweaked default settings file. * Explained why BASE_DIR exists. * Added a link to the database configuration options, and put it in its own section. * Moved sensitive settings that must be changed for production at the top. commit 6515fd2f1aa73a86dc8dbd2ccf512ddb6b140d57 Author: Aymeric Augustin <aymeric.augustin@m4x.org> Date: Tue Jan 29 14:35:21 2013 +0100 Documented the simplified app & project templates in the changelog. commit 2c5b576c2ea91d84273a019b3d0b3b8b4da72f23 Author: Aymeric Augustin <aymeric.augustin@m4x.org> Date: Tue Jan 29 13:59:27 2013 +0100 Minor fixes in tutorials 5 and 6. commit 55a51531be8104f21b3cca3f6bf70b0a7139a041 Author: Aymeric Augustin <aymeric.augustin@m4x.org> Date: Tue Jan 29 13:51:11 2013 +0100 Updated tutorial 2 for the new project template. commit 29ddae87bdaecff12dd31b16b000c01efbde9e20 Author: Aymeric Augustin <aymeric.augustin@m4x.org> Date: Tue Jan 29 11:58:54 2013 +0100 Updated tutorial 1 for the new project template. commit 0ecb9f6e2514cfd26a678a280d471433375101a3 Author: Aymeric Augustin <aymeric.augustin@m4x.org> Date: Tue Jan 29 11:29:13 2013 +0100 Adjusted the default URLconf detection to account for the admin. It's now enabled by default. commit 5fb4da0d3d09dac28dd94e3fde92b9d4335c0565 Author: Aymeric Augustin <aymeric.augustin@m4x.org> Date: Tue Jan 29 10:36:55 2013 +0100 Added security warnings for the most sensitive settings. commit 718d84bd8ac4a42fb4b28ec93965de32680f091e Author: Aymeric Augustin <aymeric.augustin@m4x.org> Date: Mon Jan 28 23:24:06 2013 +0100 Used an absolute path for the SQLite database. This ensures the settings file works regardless of which directory django-admin.py / manage.py is invoked from. BASE_DIR got a +1 from a BDFL and another core dev. It doesn't involve the concept of a "Django project"; it's just a convenient way to express relative paths within the source code repository for non-Python files. Thanks Jacob Kaplan-Moss for the suggestion. commit 1b559b4bcda622e10909b68fe5cab90db6727dd9 Author: Aymeric Augustin <aymeric.augustin@m4x.org> Date: Mon Jan 28 23:22:40 2013 +0100 Removed STATIC_ROOT from the default settings template. It isn't necessary in development, and it confuses beginners to no end. Thanks Carl Meyer for the suggestion. commit a55f141a500bb7c9a1bc259bbe1954c13b199671 Author: Aymeric Augustin <aymeric.augustin@m4x.org> Date: Mon Jan 28 23:21:43 2013 +0100 Removed MEDIA_ROOT/URL from default settings template. Many sites will never deal with user-uploaded files, and MEDIA_ROOT is complicated to explain. Thanks Carl Meyer for the suggestion. commit 44bf2f2441420fd9429ee9fe1f7207f92dd87e70 Author: Aymeric Augustin <aymeric.augustin@m4x.org> Date: Mon Jan 28 22:22:09 2013 +0100 Removed logging config. This configuration is applied regardless of the value of LOGGING; duplicating it in LOGGING is confusing. commit eac747e848eaed65fd5f6f254f0a7559d856f88f Author: Aymeric Augustin <aymeric.augustin@m4x.org> Date: Mon Jan 28 22:05:31 2013 +0100 Enabled the locale middleware by default. USE_I18N is True by default, and doesn't work well without LocaleMiddleware. commit d806c62b2d00826dc2688c84b092627b8d571cab Author: Aymeric Augustin <aymeric.augustin@m4x.org> Date: Mon Jan 28 22:03:16 2013 +0100 Enabled clickjacking protection by default. commit 99152c30e6a15003f0b6737dc78e87adf462aacb Author: Aymeric Augustin <aymeric.augustin@m4x.org> Date: Mon Jan 28 22:01:48 2013 +0100 Reorganized settings in logical sections, and trimmed comments. commit d37ffdfcb24b7e0ec7cc113d07190f65fb12fb8a Author: Aymeric Augustin <aymeric.augustin@m4x.org> Date: Mon Jan 28 16:54:11 2013 +0100 Avoided misleading TEMPLATE_DEBUG = DEBUG. According to the docs TEMPLATE_DEBUG works only when DEBUG = True. commit 15d9478d3a9850e85841e7cf09cf83050371c6bf Author: Aymeric Augustin <aymeric.augustin@m4x.org> Date: Mon Jan 28 16:46:25 2013 +0100 Removed STATICFILES_FINDERS/TEMPLATE_LOADERS from default settings file. Only developers with special needs ever need to change these settings. commit 574da0eb5bfb4570883756914b4dbd7e20e1f61e Author: Aymeric Augustin <aymeric.augustin@m4x.org> Date: Mon Jan 28 16:45:01 2013 +0100 Removed STATICFILES/TEMPLATES_DIRS from default settings file. The current best practice is to put static files and templates in applications, for easier testing and deployment. commit 8cb18dbe56629aa1be74718a07e7cc66b4f9c9f0 Author: Aymeric Augustin <aymeric.augustin@m4x.org> Date: Mon Jan 28 16:24:16 2013 +0100 Removed settings related to email reporting from default settings file. While handy for small scale projects, it isn't exactly a best practice. commit 8ecbfcb3638058f0c49922540f874a7d802d864f Author: Aymeric Augustin <aymeric.augustin@m4x.org> Date: Tue Jan 29 18:54:43 2013 +0100 Documented how to enable the sites framework. commit 23fc91a6fa67d91ddd9d71b1c3e0dc26bdad9841 Author: Aymeric Augustin <aymeric.augustin@m4x.org> Date: Mon Jan 28 16:28:59 2013 +0100 Disabled the sites framework by default. RequestSite does the job for single-domain websites. commit c4d82eb8afc0eb8568bf9c4d12644272415e3960 Author: Aymeric Augustin <aymeric.augustin@m4x.org> Date: Tue Jan 29 00:08:33 2013 +0100 Added a default admin.py to the application template. Thanks Ryan D Hiebert for the suggestion. commit 4071dc771e5c44b1c5ebb9beecefb164ae465e22 Author: Aymeric Augustin <aymeric.augustin@m4x.org> Date: Mon Jan 28 10:59:49 2013 +0100 Enabled the admin by default. Everyone uses the admin. commit c807a31f8d89e7e7fd97380e3023f7983a8b6fcb Author: Aymeric Augustin <aymeric.augustin@m4x.org> Date: Mon Jan 28 10:57:05 2013 +0100 Removed admindocs from default project template. commit 09e4ce0e652a97da1a9e285046a91c8ad7a9189c Author: Aymeric Augustin <aymeric.augustin@m4x.org> Date: Mon Jan 28 16:32:52 2013 +0100 Added links to the settings documentation. commit 5b8f5eaef364eb790fcde6f9e86f7d266074cca8 Author: Aymeric Augustin <aymeric.augustin@m4x.org> Date: Mon Jan 28 11:06:54 2013 +0100 Used a significant example for URLconf includes. commit 908e91d6fcee2a3cb51ca26ecdf12a6a24e69ef8 Author: Aymeric Augustin <aymeric.augustin@m4x.org> Date: Mon Jan 28 16:22:31 2013 +0100 Moved code comments about WSGI to docs, and rewrote said docs. commit 50417e51996146f891d08ca8b74dcc736a581932 Author: Aymeric Augustin <aymeric.augustin@m4x.org> Date: Mon Jan 28 15:51:50 2013 +0100 Normalized the default application template. Removed the default test that 1 + 1 = 2, because it's been committed way too many times, in too many projects. Added an import of `render` for views, because the first view will often be: def home(request): return render(request, "mysite/home.html")
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By default, the middleware will set the ``X-Frame-Options`` header to
``SAMEORIGIN`` for every outgoing ``HttpResponse``. If you want ``DENY``
instead, set the :setting:`X_FRAME_OPTIONS` setting::
X_FRAME_OPTIONS = 'DENY'
When using the middleware there may be some views where you do **not** want the
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``X-Frame-Options`` header set. For those cases, you can use a view decorator
that tells the middleware not to set the header::
from django.http import HttpResponse
from django.views.decorators.clickjacking import xframe_options_exempt
@xframe_options_exempt
def ok_to_load_in_a_frame(request):
return HttpResponse("This page is safe to load in a frame on any site.")
Setting X-Frame-Options per view
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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To set the ``X-Frame-Options`` header on a per view basis, Django provides these
decorators::
from django.http import HttpResponse
from django.views.decorators.clickjacking import xframe_options_deny
from django.views.decorators.clickjacking import xframe_options_sameorigin
@xframe_options_deny
def view_one(request):
return HttpResponse("I won't display in any frame!")
@xframe_options_sameorigin
def view_two(request):
return HttpResponse("Display in a frame if it's from the same origin as me.")
Note that you can use the decorators in conjunction with the middleware. Use of
a decorator overrides the middleware.
Limitations
===========
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The ``X-Frame-Options`` header will only protect against clickjacking in a
modern browser. Older browsers will quietly ignore the header and need `other
clickjacking prevention techniques`_.
Browsers that support X-Frame-Options
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
* Internet Explorer 8+
* Firefox 3.6.9+
* Opera 10.5+
* Safari 4+
* Chrome 4.1+
See also
~~~~~~~~
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A `complete list`_ of browsers supporting ``X-Frame-Options``.
.. _complete list: https://developer.mozilla.org/en/The_X-FRAME-OPTIONS_response_header#Browser_compatibility
.. _other clickjacking prevention techniques: http://en.wikipedia.org/wiki/Clickjacking#Prevention