# dokumentasi Django 2.0.8

# Perlindungan Cross Site Request Forgery

The CSRF middleware and template tag provides easy-to-use protection against Cross Site Request Forgeries. This type of attack occurs when a malicious website contains a link, a form button or some JavaScript that is intended to perform some action on your website, using the credentials of a logged-in user who visits the malicious site in their browser. A related type of attack, 'login CSRF', where an attacking site tricks a user's browser into logging into a site with someone else's credentials, is also covered.

The first defense against CSRF attacks is to ensure that GET requests (and other 'safe' methods, as defined by RFC 7231#section-4.2.1) are side effect free. Requests via 'unsafe' methods, such as POST, PUT, and DELETE, can then be protected by following the steps below.

## Bagaimana menggunakannya

To take advantage of CSRF protection in your views, follow these steps:

1. The CSRF middleware is activated by default in the `MIDDLEWARE` setting. If you override that setting, remember that `'django.middleware.csrf.CsrfViewMiddleware'` should come before any view middleware that assume that CSRF attacks have been dealt with.

   If you disabled it, which is not recommended, you can use `csrf_protect()` on particular views you want to protect (see below).

2. In any template that uses a POST form, use the `csrf_token` tag inside the `<form>` element if the form is for an internal URL, e.g.:

       <form method="post">{% csrf_token %}

   This should not be done for POST forms that target external URLs, since that would cause the CSRF token to be leaked, leading to a vulnerability.

3. In the corresponding view functions, ensure that `RequestContext` is used to render the response so that `{% csrf_token %}` will work properly. If you're using the `render()` function, generic views, or contrib apps, you are covered already since these all use `RequestContext`.

### AJAX

While the above method can be used for AJAX POST requests, it has some inconveniences: you have to remember to pass the CSRF token in as POST data with every POST request. For this reason, there is an alternative method: on each XMLHttpRequest, set a custom `X-CSRFToken` header to the value of the CSRF token. This is often easier, because many JavaScript frameworks provide hooks that allow headers to be set on every request.

First, you must get the CSRF token. How to do that depends on whether or not the `CSRF_USE_SESSIONS` setting is enabled.

#### Mendapatkan token jika `CSRF_USE_SESSIONS` adalah `False`

The recommended source for the token is the `csrftoken` cookie, which will be set if you've enabled CSRF protection for your views as outlined above.

Catatan

The CSRF token cookie is named `csrftoken` by default, but you can control the cookie name via the `CSRF_COOKIE_NAME` setting.

The CSRF header name is `HTTP_X_CSRFTOKEN` by default, but you can customize it using the `CSRF_HEADER_NAME` setting.

Mendapatkan token adalah mudah:

    // using jQuery
    function getCookie(name) {
        var cookieValue = null;
        if (document.cookie && document.cookie !== '') {
            var cookies = document.cookie.split(';');
            for (var i = 0; i < cookies.length; i++) {
                var cookie = jQuery.trim(cookies[i]);
                // Does this cookie string begin with the name we want?
                if (cookie.substring(0, name.length + 1) === (name + '=')) {
                    cookieValue = decodeURIComponent(cookie.substring(name.length + 1));
                    break;
                }
            }
        }
        return cookieValue;
    }
    var csrftoken = getCookie('csrftoken');

Kode diatas dapat disederhanakan menggunakan JavaScript Cookie library untuk mengganti `getCookie`:

    var csrftoken = Cookies.get('csrftoken');

Catatan

The CSRF token is also present in the DOM, but only if explicitly included using `csrf_token` in a template. The cookie contains the canonical token; the `CsrfViewMiddleware` will prefer the cookie to the token in the DOM. Regardless, you're guaranteed to have the cookie if the token is present in the DOM, so you should use the cookie!

Peringatan

If your view is not rendering a template containing the `csrf_token` template tag, Django might not set the CSRF token cookie. This is common in cases where forms are dynamically added to the page. To address this case, Django provides a view decorator which forces setting of the cookie: `ensure_csrf_cookie()`.

#### Mendapatkan token jika `CSRF_USE_SESSIONS` adalah `True`

Jika anda mengaktifkan `CSRF_USE_SESSIONS`, anda harus menyertakan token-CSRF dalam HTML anda dan membaca token dari DOM dengan JavaScript:

    {% csrf_token %}
    <script type="text/javascript">
    // using jQuery
    var csrftoken = jQuery("[name=csrfmiddlewaretoken]").val();
    </script>

#### Mengatur token pada permintaan AJAX

Finally, you'll have to actually set the header on your AJAX request, while protecting the CSRF token from being sent to other domains using settings.crossDomain in jQuery 1.5.1 and newer:

    function csrfSafeMethod(method) {
        // these HTTP methods do not require CSRF protection
        return (/^(GET|HEAD|OPTIONS|TRACE)$/.test(method));
    }
    $.ajaxSetup({
        beforeSend: function(xhr, settings) {
            if (!csrfSafeMethod(settings.type) && !this.crossDomain) {
                xhr.setRequestHeader("X-CSRFToken", csrftoken);
            }
        }
    });

If you're using AngularJS 1.1.3 and newer, it's sufficient to configure the `$http` provider with the cookie and header names:

    $httpProvider.defaults.xsrfCookieName = 'csrftoken';
    $httpProvider.defaults.xsrfHeaderName = 'X-CSRFToken';

### Menggunakan CSRF dalam cetakan Jinja2

Django's `Jinja2` template backend adds `{{ csrf_input }}` to the context of all templates which is equivalent to `{% csrf_token %}` in the Django template language. For example:

    <form method="post">{{ csrf_input }}

### Cara penghias

Rather than adding `CsrfViewMiddleware` as a blanket protection, you can use the `csrf_protect` decorator, which has exactly the same functionality, on particular views that need the protection. It must be used both on views that insert the CSRF token in the output, and on those that accept the POST form data. (These are often the same view function, but not always).

Use of the decorator by itself is not recommended, since if you forget to use it, you will have a security hole. The 'belt and braces' strategy of using both is fine, and will incur minimal overhead.

`csrf_protect`(view)

  Penghias yang menyediakan perlindungan dari `CsrfViewMiddleware` ke sebuah tampilan.

  Penggunaan:

      from django.shortcuts import render
      from django.views.decorators.csrf import csrf_protect

      @csrf_protect
      def my_view(request):
          c = {}
          # ...
          return render(request, "a_template.html", c)

  Jika anda sedang menggunakan tampilan berdasarkan-kelas, anda dapat mengacu ke Decorating class-based views1.

## Permintaan tertolak

Secara awalan, sebuah tanggapan '403 Forbidden' dikirim ke pengguna jika sebuah permintaan datang gaagl melakukan pemeriksaan oleh `CsrfViewMiddleware`. Ini harus biasanya hanya dilihat ketika ada Cross Site Request Forgery asli, atau ketika, karena pada kesalahan pemrograman, token CSRF belum dimasukkan dengan formulir POST.

Halaman kesalahan, bagaimanapun, itu tidak sangat ramah, jadi anda mungkin ingin menyediakan tampilan anda sendiri untuk menangani kondisi ini. Untuk melakukan ini, cukup setel pengaturan `CSRF_FAILURE_VIEW`.

Kegagalan CSRF adalah tercatat sebagai peringatan pada pencatat django.security.csrf 1.

Changed in Django 1.11:

Dalam versi terlama, kegagalan CSRF dicatat pada pencatat `django.request`.

## Bagaimana itu bekerja

Perlindungan CSRF berdasarkan pada hal-hal berikut:

1. Sebuah kue CSRF yaitu berdasarkan pada nilai rahasia acak, yang situs-situs lain tidak akan mengaksesnya.

   This cookie is set by `CsrfViewMiddleware`. It is sent with every response that has called `django.middleware.csrf.get_token()` (the function used internally to retrieve the CSRF token), if it wasn't already set on the request.

   Untuk terlindungi terhadap serangan BREACH, token tidak cukup rahasia; sebuah garam acak ditambahkan ke rahasia dan digunakan untuk mengaduk itu.

   Untuk alasan keamanan, nilai dari rahasia berubah setiap waktu pengguna masuk.

2. A hidden form field with the name 'csrfmiddlewaretoken' present in all outgoing POST forms. The value of this field is, again, the value of the secret, with a salt which is both added to it and used to scramble it. The salt is regenerated on every call to `get_token()` so that the form field value is changed in every such response.

   Bagian selesai dengan etiket cetakan.

3. For all incoming requests that are not using HTTP GET, HEAD, OPTIONS or TRACE, a CSRF cookie must be present, and the 'csrfmiddlewaretoken' field must be present and correct. If it isn't, the user will get a 403 error.

   When validating the 'csrfmiddlewaretoken' field value, only the secret, not the full token, is compared with the secret in the cookie value. This allows the use of ever-changing tokens. While each request may use its own token, the secret remains common to all.

   Pemeriksaan ini selesai dengan `CsrfViewMiddleware`.

4. In addition, for HTTPS requests, strict referer checking is done by `CsrfViewMiddleware`. This means that even if a subdomain can set or modify cookies on your domain, it can't force a user to post to your application since that request won't come from your own exact domain.

   This also addresses a man-in-the-middle attack that's possible under HTTPS when using a session independent secret, due to the fact that HTTP `Set-Cookie` headers are (unfortunately) accepted by clients even when they are talking to a site under HTTPS. (Referer checking is not done for HTTP requests because the presence of the `Referer` header isn't reliable enough under HTTP.)

   If the `CSRF_COOKIE_DOMAIN` setting is set, the referer is compared against it. This setting supports subdomains. For example, `CSRF_COOKIE_DOMAIN = '.example.com'` will allow POST requests from `www.example.com` and `api.example.com`. If the setting is not set, then the referer must match the HTTP `Host` header.

   Expanding the accepted referers beyond the current host or cookie domain can be done with the `CSRF_TRUSTED_ORIGINS` setting.

Ini memastikan bahwa hanya formulir yang asli dari ranah terpercaya dapat digunakan untuk data POST kembali.

It deliberately ignores GET requests (and other requests that are defined as 'safe' by RFC 7231). These requests ought never to have any potentially dangerous side effects , and so a CSRF attack with a GET request ought to be harmless. RFC 7231 defines POST, PUT, and DELETE as 'unsafe', and all other methods are also assumed to be unsafe, for maximum protection.

The CSRF protection cannot protect against man-in-the-middle attacks, so use HTTPS with HTTP Strict Transport Security. It also assumes validation of the HOST header and that there aren't any cross-site scripting vulnerabilities on your site (because XSS vulnerabilities already let an attacker do anything a CSRF vulnerability allows and much worse).

Removing the `Referer` header

To avoid disclosing the referrer URL to third-party sites, you might want to disable the referer on your site's `<a>` tags. For example, you might use the `<meta name="referrer" content="no-referrer">` tag or include the `Referrer-Policy: no-referrer` header. Due to the CSRF protection's strict referer checking on HTTPS requests, those techniques cause a CSRF failure on requests with 'unsafe' methods. Instead, use alternatives like `<a rel="noreferrer" ...>"` for links to third-party sites.

## Tembolok

If the `csrf_token` template tag is used by a template (or the `get_token` function is called some other way), `CsrfViewMiddleware` will add a cookie and a `Vary: Cookie` header to the response. This means that the middleware will play well with the cache middleware if it is used as instructed (`UpdateCacheMiddleware` goes before all other middleware).

However, if you use cache decorators on individual views, the CSRF middleware will not yet have been able to set the Vary header or the CSRF cookie, and the response will be cached without either one. In this case, on any views that will require a CSRF token to be inserted you should use the `django.views.decorators.csrf.csrf_protect()` decorator first:

    from django.views.decorators.cache import cache_page
    from django.views.decorators.csrf import csrf_protect

    @cache_page(60 * 15)
    @csrf_protect
    def my_view(request):
        ...

Jika anda sedang menggunakan tampilan berdasarkan-kelas, anda dapat mengacu ke Decorating class-based views1.

## Pengujian

The `CsrfViewMiddleware` will usually be a big hindrance to testing view functions, due to the need for the CSRF token which must be sent with every POST request. For this reason, Django's HTTP client for tests has been modified to set a flag on requests which relaxes the middleware and the `csrf_protect` decorator so that they no longer rejects requests. In every other respect (e.g. sending cookies etc.), they behave the same.

Jika, untuk beberapa alasan, anda ingin klien percobaan melakukan pemeriksaan CSRF, anda dapat membuat sebuah instance dari klien percobaan yang memaksa pemeriksaan CSRF:

    >>> from django.test import Client
    >>> csrf_client = Client(enforce_csrf_checks=True)

## Batasan

Subdomains within a site will be able to set cookies on the client for the whole domain. By setting the cookie and using a corresponding token, subdomains will be able to circumvent the CSRF protection. The only way to avoid this is to ensure that subdomains are controlled by trusted users (or, are at least unable to set cookies). Note that even without CSRF, there are other vulnerabilities, such as session fixation, that make giving subdomains to untrusted parties a bad idea, and these vulnerabilities cannot easily be fixed with current browsers.

## Kasus tepi

Certain views can have unusual requirements that mean they don't fit the normal pattern envisaged here. A number of utilities can be useful in these situations. The scenarios they might be needed in are described in the following section.

### Keperluan

The examples below assume you are using function-based views. If you are working with class-based views, you can refer to Decorating class-based views.

`csrf_exempt`(view)

  Penghias ini menandai sebuah tampilan sebagai menjadi pengecualian dari perlinsungan dipastikan oleh middleware. Contoh:

      from django.http import HttpResponse
      from django.views.decorators.csrf import csrf_exempt

      @csrf_exempt
      def my_view(request):
          return HttpResponse('Hello world')

`requires_csrf_token`(view)

  Normally the `csrf_token` template tag will not work if `CsrfViewMiddleware.process_view` or an equivalent like `csrf_protect` has not run. The view decorator `requires_csrf_token` can be used to ensure the template tag does work. This decorator works similarly to `csrf_protect`, but never rejects an incoming request.

  Contoh:

      from django.shortcuts import render
      from django.views.decorators.csrf import requires_csrf_token

      @requires_csrf_token
      def my_view(request):
          c = {}
          # ...
          return render(request, "a_template.html", c)

`ensure_csrf_cookie`(view)

  Penghias ini memaksa sebuah tampilan mengirim kue CSRF.

### Skenario

#### Perlindungan CSRF harus ditiadakan untuk hanya sedikit tampilan.

Kebanyakan tampilan membutuhkan perlindungan CSRF, tetapi sedikit tidak.

Pemecahan: daripada meniadakan middleware dan memberlakukan `csrf_protect` ke semua tampilan yang membutuhkan itu, adakan middleware dan gunakan `csrf_exempt()`.

#### CsrfViewMiddleware.process_view tidak digunakan

Ada kasus-kasus ketika `CsrfViewMiddleware.process_view` mungkin tidak berjalan sebelum tampilan anda berjalan - penangan 404 dan 500, sebagai contoh - tetapi anda masih butuh token CSRF dalam sebuah formulir.

Pemecahan: gunakan `requires_csrf_token()`

#### Tampilan tidak terlindungi butuh token CSRF

There may be some views that are unprotected and have been exempted by `csrf_exempt`, but still need to include the CSRF token.

Pemecahan: gunakan `csrf_exempt()` diikuti oleh `requires_csrf_token()`. (yaitu `requires_csrf_token` harus berupa penghias paling dalam).

#### Tampilan butuh perlindungan untuk satu jalur

A view needs CSRF protection under one set of conditions only, and mustn't have it for the rest of the time.

Solution: use `csrf_exempt()` for the whole view function, and `csrf_protect()` for the path within it that needs protection. Example:

    from django.views.decorators.csrf import csrf_exempt, csrf_protect

    @csrf_exempt
    def my_view(request):

        @csrf_protect
        def protected_path(request):
            do_something()

        if some_condition():
           return protected_path(request)
        else:
           do_something_else()

#### Page uses AJAX without any HTML form

A page makes a POST request via AJAX, and the page does not have an HTML form with a `csrf_token` that would cause the required CSRF cookie to be sent.

Solution: use `ensure_csrf_cookie()` on the view that sends the page.

## Contrib and reusable apps

Because it is possible for the developer to turn off the `CsrfViewMiddleware`, all relevant views in contrib apps use the `csrf_protect` decorator to ensure the security of these applications against CSRF. It is recommended that the developers of other reusable apps that want the same guarantees also use the `csrf_protect` decorator on their views.

## Pengaturan

A number of settings can be used to control Django's CSRF behavior:

- `CSRF_COOKIE_AGE`
- `CSRF_COOKIE_DOMAIN`
- `CSRF_COOKIE_HTTPONLY`
- `CSRF_COOKIE_NAME`
- `CSRF_COOKIE_PATH`
- `CSRF_COOKIE_SECURE`
- `CSRF_FAILURE_VIEW`
- `CSRF_HEADER_NAME`
- `CSRF_TRUSTED_ORIGINS`
- `CSRF_USE_SESSIONS`

## Pertanyaan Sering Ditanya

### Is posting an arbitrary CSRF token pair (cookie and POST data) a vulnerability?

No, this is by design. Without a man-in-the-middle attack, there is no way for an attacker to send a CSRF token cookie to a victim's browser, so a successful attack would need to obtain the victim's browser's cookie via XSS or similar, in which case an attacker usually doesn't need CSRF attacks.

Beberapa alat-alat pemeriksaan keamanan menandai ini sebagai sebuah masalah seperti disebutkan sebelumnya, seorang penyerang tidak dapat mencuri kue CSRF peramban pengguna. "Stealing" atau merubah token milik anda menggunakan Firebug, alat-alat pengembangan Chrome, dll. tidak rentan.

### Is it a problem that Django's CSRF protection isn't linked to a session by default?

No, this is by design. Not linking CSRF protection to a session allows using the protection on sites such as a pastebin that allow submissions from anonymous users which don't have a session.

If you wish to store the CSRF token in the user's session, use the `CSRF_USE_SESSIONS` setting.

### Why might a user encounter a CSRF validation failure after logging in?

For security reasons, CSRF tokens are rotated each time a user logs in. Any page with a form generated before a login will have an old, invalid CSRF token and need to be reloaded. This might happen if a user uses the back button after a login or if they log in in a different browser tab.