This document explains all middleware components that come with Django. For information on how to use them and how to write your own middleware, see the middleware usage guide.
UpdateCacheMiddleware¶FetchFromCacheMiddleware¶サイト全体でキャッシュを有効にします。有効にすると、Django を利用している各ページは CACHE_MIDDLEWARE_SECONDS 設定で指定した時間だけキャッシュされます。詳しくは the cache documentation を読んでください。
CommonMiddleware¶完璧主義者のためにいくつかの便利な機能を提供します。
DISALLOWED_USER_AGENTS 設定に含まれるユーザーエージェントのアクセスを禁止します。この設定は、コンパイルした正規表現オブジェクトのリストである必要があります。
APPEND_SLASH および PREPEND_WWW 設定に基づいて、URL の書き換えを実行します。
APPEND_SLASH が True で、与えられた URL がスラッシュで終わっていなくて、さらに URLconf に URL が見つからなければ、Django は / が最後に追加された新しい URL を作り、この新しい URL へリクエストをリダイレクトします。それ以外のときには、最初の URL を通常通りに処理します。
たとえば、 foo.com/bar は、 foo.com/bar に対する有効な URL パタンがなく、foo.com/bar/ に対しては有効なパタンが 存在する 場合に、 foo.com/bar/ にリダイレクトされます。
PREPEND_WWW を True にすると、先頭に "www." がない URL は "www." で始まる同じ URL にリダイレクトされます。
2つのオプションが意味するのは、URL を正規化するということです。これは、1つの URL には1つの、かつただ1つだけの場所を指すべきだという考えです。技術的には URL foo.com/bar は foo.com/bar/ とは区別されます。実際、サーチエンジンのインデクスはこれらを区別して作成されます。よって、URL を正規化するというのがベストプラクティスなのです。
If necessary, individual views may be excluded from the APPEND_SLASH
behavior using the no_append_slash()
decorator:
from django.views.decorators.common import no_append_slash
@no_append_slash
def sensitive_fbv(request, *args, **kwargs):
"""View to be excluded from APPEND_SLASH."""
return HttpResponse()
Support for the no_append_slash()
decorator was added.
Sets the Content-Length header for non-streaming responses.
CommonMiddleware.response_redirect_class¶Defaults to HttpResponsePermanentRedirect. Subclass
CommonMiddleware and override the attribute to customize the redirects
issued by the middleware.
BrokenLinkEmailsMiddleware¶MANAGERS (see
How to manage error reporting).GZipMiddleware¶警告
Security researchers recently revealed that when compression techniques
(including GZipMiddleware) are used on a website, the site may become
exposed to a number of possible attacks. Before using GZipMiddleware on
your site, you should consider very carefully whether you are subject to
these attacks. If you're in any doubt about whether you're affected, you
should avoid using GZipMiddleware. For more details, see the the BREACH
paper (PDF) and breachattack.com.
The django.middleware.gzip.GZipMiddleware compresses content for browsers
that understand GZip compression (all modern browsers).
This middleware should be placed before any other middleware that need to read or write the response body so that compression happens afterward.
It will NOT compress content if any of the following are true:
Content-Encoding header.Accept-Encoding header
containing gzip.If the response has an ETag header, the ETag is made weak to comply with
RFC 7232#section-2.1.
You can apply GZip compression to individual views using the
gzip_page() decorator.
ConditionalGetMiddleware¶Handles conditional GET operations. If the response doesn't have an ETag
header, the middleware adds one if needed. If the response has an ETag or
Last-Modified header, and the request has If-None-Match or
If-Modified-Since, the response is replaced by an
HttpResponseNotModified.
LocaleMiddleware¶リクエストからのデータに基づいた言語セクションを有効化します。この機能は、それぞれのユーザに対してコンテンツをカスタマイズします。 国際化のドキュメント を参照してください。
LocaleMiddleware.response_redirect_class¶デフォルトは HttpResponseRedirect です。LocaleMiddleware をサブクラス化して属性をオーバーライドし、ミドルウェアによって発行されたリダイレクトをカスタマイズします。
クッキーおよびセッションをベースとしたメッセージサポートを有効化します。メッセージのドキュメント を参照してください。
警告
If your deployment situation allows, it's usually a good idea to have your
front-end web server perform the functionality provided by the
SecurityMiddleware. That way, if there are requests that aren't served
by Django (such as static media or user-uploaded files), they will have
the same protections as requests to your Django application.
SecurityMiddleware¶The django.middleware.security.SecurityMiddleware provides several security
enhancements to the request/response cycle. Each one can be independently
enabled or disabled with a setting.
SECURE_CONTENT_TYPE_NOSNIFFSECURE_CROSS_ORIGIN_OPENER_POLICYSECURE_HSTS_INCLUDE_SUBDOMAINSSECURE_HSTS_PRELOADSECURE_HSTS_SECONDSSECURE_REDIRECT_EXEMPTSECURE_REFERRER_POLICYSECURE_SSL_HOSTSECURE_SSL_REDIRECTFor sites that should only be accessed over HTTPS, you can instruct modern browsers to refuse to connect to your domain name via an insecure connection (for a given period of time) by setting the "Strict-Transport-Security" header. This reduces your exposure to some SSL-stripping man-in-the-middle (MITM) attacks.
SecurityMiddleware will set this header for you on all HTTPS responses if
you set the SECURE_HSTS_SECONDS setting to a non-zero integer value.
When enabling HSTS, it's a good idea to first use a small value for testing,
for example, SECURE_HSTS_SECONDS = 3600 for one
hour. Each time a web browser sees the HSTS header from your site, it will
refuse to communicate non-securely (using HTTP) with your domain for the given
period of time. Once you confirm that all assets are served securely on your
site (i.e. HSTS didn't break anything), it's a good idea to increase this value
so that infrequent visitors will be protected (31536000 seconds, i.e. 1 year,
is common).
Additionally, if you set the SECURE_HSTS_INCLUDE_SUBDOMAINS setting
to True, SecurityMiddleware will add the includeSubDomains directive
to the Strict-Transport-Security header. This is recommended (assuming all
subdomains are served exclusively using HTTPS), otherwise your site may still
be vulnerable via an insecure connection to a subdomain.
If you wish to submit your site to the browser preload list, set the
SECURE_HSTS_PRELOAD setting to True. That appends the
preload directive to the Strict-Transport-Security header.
警告
The HSTS policy applies to your entire domain, not just the URL of the response that you set the header on. Therefore, you should only use it if your entire domain is served via HTTPS only.
Browsers properly respecting the HSTS header will refuse to allow users to bypass warnings and connect to a site with an expired, self-signed, or otherwise invalid SSL certificate. If you use HSTS, make sure your certificates are in good shape and stay that way!
注釈
If you are deployed behind a load-balancer or reverse-proxy server, and the
Strict-Transport-Security header is not being added to your responses,
it may be because Django doesn't realize that it's on a secure connection;
you may need to set the SECURE_PROXY_SSL_HEADER setting.
Browsers use the Referer header as a way to send information to a site about how users got there. When a user clicks a link, the browser will send the full URL of the linking page as the referrer. While this can be useful for some purposes -- like figuring out who's linking to your site -- it also can cause privacy concerns by informing one site that a user was visiting another site.
Some browsers have the ability to accept hints about whether they should send
the HTTP Referer header when a user clicks a link; this hint is provided
via the Referrer-Policy header. This header can suggest any of three
behaviors to browsers:
Referer header. For example, if the
user is visiting https://example.com/page.html, the Referer header
would contain "https://example.com/page.html".https://example.com/page.html, the origin would be
https://example.com/.Referer header at all.There are two types of conditions this header can tell a browser to watch out for:
https://example.com/1.html
to https://example.com/2.html is same-origin. A link from
https://example.com/page.html to https://not.example.com/page.html is
cross-origin.警告
When your site is served via HTTPS, Django's CSRF protection system requires the Referer header to be present, so
completely disabling the Referer header will interfere with CSRF
protection. To gain most of the benefits of disabling Referer headers
while also keeping CSRF protection, consider enabling only same-origin
referrers.
SecurityMiddleware can set the Referrer-Policy header for you, based on
the SECURE_REFERRER_POLICY setting (note spelling: browsers send a
Referer header when a user clicks a link, but the header instructing a
browser whether to do so is spelled Referrer-Policy). The valid values for
this setting are:
no-referrerno-referrer-when-downgradeoriginorigin-when-cross-originsame-originstrict-originstrict-origin-when-cross-originunsafe-urlUnknown Policy Values
Where a policy value is unknown by a user agent, it is possible to
specify multiple policy values to provide a fallback. The last specified
value that is understood takes precedence. To support this, an iterable or
comma-separated string can be used with SECURE_REFERRER_POLICY.
Some browsers have the ability to isolate top-level windows from other
documents by putting them in a separate browsing context group based on the
value of the Cross-Origin Opener Policy (COOP) header. If a document that
is isolated in this way opens a cross-origin popup window, the popup’s
window.opener property will be null. Isolating windows using COOP is a
defense-in-depth protection against cross-origin attacks, especially those like
Spectre which allowed exfiltration of data loaded into a shared browsing
context.
SecurityMiddleware can set the Cross-Origin-Opener-Policy header for
you, based on the SECURE_CROSS_ORIGIN_OPENER_POLICY setting. The
valid values for this setting are:
same-originsame-origin-allow-popupsunsafe-none.unsafe-nonesame-origin or
same-origin-allow-popups.X-Content-Type-Options: nosniff¶Some browsers will try to guess the content types of the assets that they
fetch, overriding the Content-Type header. While this can help display
sites with improperly configured servers, it can also pose a security
risk.
If your site serves user-uploaded files, a malicious user could upload a specially-crafted file that would be interpreted as HTML or JavaScript by the browser when you expected it to be something harmless.
To prevent the browser from guessing the content type and force it to
always use the type provided in the Content-Type header, you can pass
the X-Content-Type-Options: nosniff header. SecurityMiddleware will
do this for all responses if the SECURE_CONTENT_TYPE_NOSNIFF setting
is True.
Note that in most deployment situations where Django isn't involved in serving
user-uploaded files, this setting won't help you. For example, if your
MEDIA_URL is served directly by your front-end web server (nginx,
Apache, etc.) then you'd want to set this header there. On the other hand, if
you are using Django to do something like require authorization in order to
download files and you cannot set the header using your web server, this
setting will be useful.
サイトが HTTP と HTTPS 接続の両方をサポートしている場合、多くのユーザーはデフォルトでセキュアでない接続を行ってしまいます。最善のセキュリティのためには、すべての HTTP 接続を HTTPS 接続にリダイレクトするべきです。
SECURE_SSL_REDIRECT 設定を True に設定すれば、 SecurityMiddleware が すべての HTTP 接続を HTTPS に parmanent (HTTP 301) にリダイレクトしてくれます。
注釈
パフォーマンス上の理由により、このようなリダイレクトは Django の外部、フロントエンドのロードバランサーや nginx などのリバースプロキシサーバーで実行した方が良いです。 SECURE_SSL_REDIRECT は、これらのオプションが使用できないデプロイ環境で使われることを想定しています。
If the SECURE_SSL_HOST setting has a value, all redirects will be
sent to that host instead of the originally-requested host.
If there are a few pages on your site that should be available over HTTP, and
not redirected to HTTPS, you can list regular expressions to match those URLs
in the SECURE_REDIRECT_EXEMPT setting.
注釈
If you are deployed behind a load-balancer or reverse-proxy server and
Django can't seem to tell when a request actually is already secure, you
may need to set the SECURE_PROXY_SSL_HEADER setting.
受信側のすべての HttpRequest オブジェクトに、現在のサイトを表す site 属性を追加します。詳しくは sites documentation を読んでください。
AuthenticationMiddleware¶Adds the user attribute, representing the currently-logged-in user, to
every incoming HttpRequest object. See Authentication in web requests.
RemoteUserMiddleware¶Middleware for utilizing web server provided authentication. See How to authenticate using REMOTE_USER for usage details.
PersistentRemoteUserMiddleware¶Middleware for utilizing web server provided authentication when enabled only on the login page. See ログインページでのみ REMOTE_USER を使用する for usage details.
CsrfViewMiddleware¶POST フォームに隠しフォームフィールドを追加し、リクエストの値が正しいかチェックすることで、Cross Site Request Forgery に対するプロテクションを追加します。詳しくは Cross Site Request Forgery プロテクションのドキュメント を読んでください。
X-Frame-Options middleware¶Django の多様なミドルウェアクラスの順序に関する注意点を挙げておきます。
SSL リダイレクトを有効にしているなら、他のたくさんの必要のないミドルウェアが実行されないように、リストの先頭付近に置くべきです。
Vary ヘッダに変更を加えるミドルウェア (SessionMiddleware, GZipMiddleware, LocaleMiddleware) の前に置きます。
response body を変更・使用する可能性のあるミドルウェアの前に置きます。
Vary ヘッダを修正するため、 UpdateCacheMiddleware の後に置きます。
Before any middleware that may raise an exception to trigger an error
view (such as PermissionDenied) if you're
using CSRF_USE_SESSIONS.
Vary ヘッダを修正するため、 UpdateCacheMiddleware の後に置きます。
Before any middleware that may change the response (it sets the ETag
header).
gzip されたコンテンツに対して ETag ヘッダを計算しないように、 GZipMiddleware の後に置きます。
SessionMiddleware (session データを使う) と UpdateCacheMiddleware (Vary ヘッダを修正する) の後のできるだけ高い位置に置きます。
Before any middleware that may change the response (it sets the
Content-Length header). A middleware that appears before
CommonMiddleware and changes the response must reset Content-Length.
APPEND_SLASH か PREPEND_WWW が True に設定されているとリダイレクトされるので、先頭の近くに置きます。
After SessionMiddleware if you're using CSRF_USE_SESSIONS.
CSRF 攻撃が可能なすべての view ミドルウェアの前に置きます。
Before RemoteUserMiddleware, or any
other authentication middleware that may perform a login, and hence rotate
the CSRF token, before calling down the middleware chain.
After SessionMiddleware if you're using CSRF_USE_SESSIONS.
session ストレージを使うので、 SessionMiddleware の後に置きます。
After SessionMiddleware: can use session-based storage.
キャッシュのハッシュキーを生成するのに Vary ヘッダを使用するため、このヘッダを修正するすべてのミドルウェアのあとに置きます。
最後に実行されるタイプのミドルウェアなので、できるだけ下に置く必要があります。
最後に実行されるタイプのミドルウェアなので、できるだけ下に置く必要があります。
2022年6月01日