# Django 2.2.9.dev20191202104323 文档

# Clickjacking Protection

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.

## 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.

## 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 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.

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.

The `X-Frame-Options` HTTP header will only be set by the middleware or view decorators if it is not already present in the response.

## How to use it

### Setting `X-Frame-Options` for all responses

To set the same `X-Frame-Options` value for all responses in your site, put `'django.middleware.clickjacking.XFrameOptionsMiddleware'` to `MIDDLEWARE`:

    MIDDLEWARE = [
        ...
        'django.middleware.clickjacking.XFrameOptionsMiddleware',
        ...
    ]

This middleware is enabled in the settings file generated by `startproject`.

By default, the middleware will set the `X-Frame-Options` header to `SAMEORIGIN` for every outgoing `HttpResponse`. If you want `DENY` instead, set the `X_FRAME_OPTIONS` setting:

    X_FRAME_OPTIONS = 'DENY'

When using the middleware there may be some views where you do not want the `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.")

注解

If you want to submit a form or access a session cookie within a frame or iframe, you may need to modify the `CSRF_COOKIE_SAMESITE` or `SESSION_COOKIE_SAMESITE` settings.

### Setting `X-Frame-Options` per view

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

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

A complete list of browsers supporting `X-Frame-Options`.