This document explains all middleware components that come with Django. For\ninformation on how to use them and how to write your own middleware, see\nthe middleware usage guide.
\nEnable the site-wide cache. If these are enabled, each Django-powered page will\nbe cached for as long as the CACHE_MIDDLEWARE_SECONDS setting\ndefines. See the cache documentation.
Defaults to HttpResponsePermanentRedirect.\nSubclass CommonMiddleware and override the attribute to customize\nthe redirects issued by the middleware.
Adds a few conveniences for perfectionists:
\nForbids access to user agents in the DISALLOWED_USER_AGENTS\nsetting, which should be a list of compiled regular expression objects.
Performs URL rewriting based on the APPEND_SLASH and\nPREPEND_WWW settings.
If APPEND_SLASH is True and the initial URL doesn’t end\nwith a slash, and it is not found in the URLconf, then a new URL is\nformed by appending a slash at the end. If this new URL is found in the\nURLconf, then Django redirects the request to this new URL. Otherwise,\nthe initial URL is processed as usual.
For example, foo.com/bar will be redirected to foo.com/bar/ if\nyou don’t have a valid URL pattern for foo.com/bar but do have a\nvalid pattern for foo.com/bar/.
If PREPEND_WWW is True, URLs that lack a leading «www.»\nwill be redirected to the same URL with a leading «www.»
Both of these options are meant to normalize URLs. The philosophy is that\neach URL should exist in one, and only one, place. Technically a URL\nfoo.com/bar is distinct from foo.com/bar/ – a search-engine\nindexer would treat them as separate URLs – so it’s best practice to\nnormalize URLs.
If necessary, individual views may be excluded from the APPEND_SLASH\nbehavior using the no_append_slash()\ndecorator:
from django.views.decorators.common import no_append_slash\n\n\n@no_append_slash\ndef sensitive_fbv(request, *args, **kwargs):\n """View to be excluded from APPEND_SLASH."""\n return HttpResponse()\nSets the Content-Length header for non-streaming responses.
Sends broken link notification emails to MANAGERS (see\nCome gestire il report degli errori).
Defaults to 100. Subclass GZipMiddleware and override the attribute\nto change the maximum number of random bytes that is included with\ncompressed responses.
The django.middleware.gzip.GZipMiddleware compresses content for browsers\nthat understand GZip compression (all modern browsers).
This middleware should be placed before any other middleware that need to\nread or write the response body so that compression happens afterward.
\nIt will NOT compress content if any of the following are true:
\nThe content body is less than 200 bytes long.
The response has already set the Content-Encoding header.
The request (the browser) hasn’t sent an Accept-Encoding header\ncontaining gzip.
If the response has an ETag header, the ETag is made weak to comply with\nRFC 9110 Section 8.8.1.
You can apply GZip compression to individual views using the\ngzip_page() decorator.
Handles conditional GET operations. If the response doesn’t have an ETag\nheader, the middleware adds one if needed. If the response has an ETag or\nLast-Modified header, and the request has If-None-Match or\nIf-Modified-Since, the response is replaced by an\nHttpResponseNotModified.
You can handle conditional GET operations with individual views using the\nconditional_page() decorator.
Defaults to HttpResponseRedirect. Subclass\nLocaleMiddleware and override the attribute to customize the\nredirects issued by the middleware.
Enables language selection based on data from the request. It customizes\ncontent for each user. See the internationalization documentation.
\nEnables cookie- and session-based message support. See the\nmessages documentation.
\nThe django.middleware.security.SecurityMiddleware provides several security\nenhancements to the request/response cycle. Each one can be independently\nenabled or disabled with a setting.
For sites that should only be accessed over HTTPS, you can instruct modern\nbrowsers to refuse to connect to your domain name via an insecure connection\n(for a given period of time) by setting the «Strict-Transport-Security»\nheader. This reduces your exposure to some SSL-stripping man-in-the-middle\n(MITM) attacks.
\nSecurityMiddleware will set this header for you on all HTTPS responses if\nyou 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,\nfor example, SECURE_HSTS_SECONDS = 3600 for one\nhour. Each time a web browser sees the HSTS header from your site, it will\nrefuse to communicate non-securely (using HTTP) with your domain for the given\nperiod of time. Once you confirm that all assets are served securely on your\nsite (i.e. HSTS didn’t break anything), it’s a good idea to increase this value\nso that infrequent visitors will be protected (31536000 seconds, i.e. 1 year,\nis common).
Additionally, if you set the SECURE_HSTS_INCLUDE_SUBDOMAINS setting\nto True, SecurityMiddleware will add the includeSubDomains\ndirective to the Strict-Transport-Security header. This is recommended\n(assuming all subdomains are served exclusively using HTTPS), otherwise your\nsite 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\nSECURE_HSTS_PRELOAD setting to True. That appends the\npreload directive to the Strict-Transport-Security header.
Browsers use the Referer header as a way to send information to a site\nabout how users got there. When a user clicks a link, the browser will send the\nfull URL of the linking page as the referrer. While this can be useful for some\npurposes – like figuring out who’s linking to your site – it also can cause\nprivacy concerns by informing one site that a user was visiting another site.
\nSome browsers have the ability to accept hints about whether they should send\nthe HTTP Referer header when a user clicks a link; this hint is provided\nvia the Referrer-Policy header. This header can suggest any of three\nbehaviors to browsers:
Full URL: send the entire URL in the Referer header. For example, if the\nuser is visiting https://example.com/page.html, the Referer header\nwould contain "https://example.com/page.html".
Origin only: send only the «origin» in the referrer. The origin consists of\nthe scheme, host and (optionally) port number. For example, if the user is\nvisiting https://example.com/page.html, the origin would be\nhttps://example.com/.
No referrer: do not send a Referer header at all.
There are two types of conditions this header can tell a browser to watch out\nfor:
\nSame-origin versus cross-origin: a link from https://example.com/1.html\nto https://example.com/2.html is same-origin. A link from\nhttps://example.com/page.html to https://not.example.com/page.html is\ncross-origin.
Protocol downgrade: a downgrade occurs if the page containing the link is\nserved via HTTPS, but the page being linked to is not served via HTTPS.
SecurityMiddleware can set the Referrer-Policy header for you, based on\nthe SECURE_REFERRER_POLICY setting (note spelling: browsers send a\nReferer header when a user clicks a link, but the header instructing a\nbrowser whether to do so is spelled Referrer-Policy). The valid values for\nthis setting are:
no-referrerInstructs the browser to send no referrer for links clicked on this site.
\nno-referrer-when-downgradeInstructs the browser to send a full URL as the referrer, but only when no\nprotocol downgrade occurs.
\noriginInstructs the browser to send only the origin, not the full URL, as the\nreferrer.
\norigin-when-cross-originInstructs the browser to send the full URL as the referrer for same-origin\nlinks, and only the origin for cross-origin links.
\nsame-origin Instructs the browser to send a full URL, but only for\nsame-origin links. No referrer will be sent for cross-origin links.
strict-origin Instructs the browser to send only the origin, not the full\nURL, and to send no referrer when a protocol downgrade occurs.
strict-origin-when-cross-originInstructs the browser to send the full URL when the link is same-origin and\nno protocol downgrade occurs; send only the origin when the link is\ncross-origin and no protocol downgrade occurs; and no referrer when a\nprotocol downgrade occurs.
\nunsafe-urlInstructs the browser to always send the full URL as the referrer.
\nSome browsers have the ability to isolate top-level windows from other\ndocuments by putting them in a separate browsing context group based on the\nvalue of the Cross-Origin Opener Policy (COOP) header. If a document that\nis isolated in this way opens a cross-origin popup window, the popup’s\nwindow.opener property will be null. Isolating windows using COOP is a\ndefense-in-depth protection against cross-origin attacks, especially those like\nSpectre which allowed exfiltration of data loaded into a shared browsing\ncontext.
SecurityMiddleware can set the Cross-Origin-Opener-Policy header for\nyou, based on the SECURE_CROSS_ORIGIN_OPENER_POLICY setting. The\nvalid values for this setting are:
same-originIsolates the browsing context exclusively to same-origin documents.\nCross-origin documents are not loaded in the same browsing context. This\nis the default and most secure option.
\nsame-origin-allow-popupsIsolates the browsing context to same-origin documents or those which\neither don’t set COOP or which opt out of isolation by setting a COOP of\nunsafe-none.
unsafe-noneAllows the document to be added to its opener’s browsing context group\nunless the opener itself has a COOP of same-origin or\nsame-origin-allow-popups.
X-Content-Type-Options: nosniffLink to this heading#Some browsers will try to guess the content types of the assets that they\nfetch, overriding the Content-Type header. While this can help display\nsites with improperly configured servers, it can also pose a security\nrisk.
If your site serves user-uploaded files, a malicious user could upload a\nspecially-crafted file that would be interpreted as HTML or JavaScript by\nthe browser when you expected it to be something harmless.
\nTo prevent the browser from guessing the content type and force it to\nalways use the type provided in the Content-Type header, you can pass\nthe X-Content-Type-Options: nosniff header. SecurityMiddleware will\ndo this for all responses if the SECURE_CONTENT_TYPE_NOSNIFF setting\nis True.
Note that in most deployment situations where Django isn’t involved in serving\nuser-uploaded files, this setting won’t help you. For example, if your\nMEDIA_URL is served directly by your front-end web server (nginx,\nApache, etc.) then you’d want to set this header there. On the other hand, if\nyou are using Django to do something like require authorization in order to\ndownload files and you cannot set the header using your web server, this\nsetting will be useful.
If your site offers both HTTP and HTTPS connections, most users will end up\nwith an unsecured connection by default. For best security, you should redirect\nall HTTP connections to HTTPS.
\nIf you set the SECURE_SSL_REDIRECT setting to True,\nSecurityMiddleware will permanently (HTTP 301) redirect all HTTP\nconnections to HTTPS.
If the SECURE_SSL_HOST setting has a value, all redirects will be\nsent 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\nnot redirected to HTTPS, you can list regular expressions to match those URLs\nin the SECURE_REDIRECT_EXEMPT setting.
Enables session support. See the session documentation.
\nAdds the site attribute representing the current site to every incoming\nHttpRequest object. See the sites documentation.
Adds the user attribute, representing the currently-logged-in user, to\nevery incoming HttpRequest object. See Authentication in web requests.
Subclass the middleware and override the following attributes and methods\nto customize behavior for unauthenticated requests.
\nDefaults to "next".
Returns the URL that unauthenticated requests will be redirected to.\nThis result is either the login_url set on the\nlogin_required() decorator (if\nnot None), or settings.LOGIN_URL.
Returns the name of the query parameter that contains the URL the user\nshould be redirected to after a successful login. This result is either\nthe redirect_field_name set on the\nlogin_required() decorator (if\nnot None), or redirect_field_name. If None is returned,\na query parameter won’t be added.
Redirects all unauthenticated requests to a login page, except for views\nexcluded with login_not_required(). The\nlogin page defaults to settings.LOGIN_URL, but can be\ncustomized.
Enable this middleware by adding it to the MIDDLEWARE setting\nafter AuthenticationMiddleware:
MIDDLEWARE = [\n "...",\n "django.contrib.auth.middleware.AuthenticationMiddleware",\n "django.contrib.auth.middleware.LoginRequiredMiddleware",\n "...",\n]\nMake a view public, allowing unauthenticated requests, with\nlogin_not_required(). For example:
from django.contrib.auth.decorators import login_not_required\n\n\n@login_not_required\ndef contact_us(request): ...\nCustomize the login URL or field name for authenticated views with the\nlogin_required() decorator to set\nlogin_url or redirect_field_name respectively. For example:
from django.contrib.auth.decorators import login_required\nfrom django.utils.decorators import method_decorator\nfrom django.views.generic import View\n\n\n@login_required(login_url="/books/login/", redirect_field_name="redirect_to")\ndef book_dashboard(request): ...\n\n\n@method_decorator(\n login_required(login_url="/books/login/", redirect_field_name="redirect_to"),\n name="dispatch",\n)\nclass BookMetrics(View):\n pass\nMiddleware for utilizing web server provided authentication. See\nCome autenticarsi usando REMOTE_USER for usage details, including security\nconsiderations.
\nMiddleware for utilizing web server provided authentication when enabled only\non the login page. See Usare REMOTE_USER solo sulle pagine di login for usage\ndetails, including security considerations.
\nAdds protection against Cross Site Request Forgeries by adding hidden form\nfields to POST forms and checking requests for the correct value. See the\nCross Site Request Forgery protection documentation.
\nYou can add Cross Site Request Forgery protection to individual views using the\ncsrf_protect() decorator.
X-Frame-Options middlewareLink to this heading#Simple clickjacking protection via the X-Frame-Options header.
\nAdds support for Content Security Policy (CSP), which helps mitigate risks such\nas Cross-Site Scripting (XSS) and data injection attacks by controlling the\nsources of content that can be loaded in the browser. See the\nOverview documentation for details on configuring policies.
\nThis middleware sets the following headers on the response depending on the\navailable settings:
\nContent-Security-Policy, based on SECURE_CSP.
Content-Security-Policy-Report-Only, based on\nSECURE_CSP_REPORT_ONLY.
Here are some hints about the ordering of various Django middleware classes:
\nIt should go near the top of the list if you’re going to turn on the SSL\nredirect as that avoids running through a bunch of other unnecessary\nmiddleware.
\nBefore those that modify the Vary header (SessionMiddleware,\nGZipMiddleware, LocaleMiddleware).
Before any middleware that may change or use the response body.
\nAfter UpdateCacheMiddleware: Modifies Vary header.
Before any middleware that may raise an exception to trigger an error\nview (such as PermissionDenied) if you’re\nusing CSRF_USE_SESSIONS.
After UpdateCacheMiddleware: Modifies Vary header.
Before any middleware that may change the response (it sets the ETag\nheader).
After GZipMiddleware so it won’t calculate an ETag header on gzipped\ncontents.
One of the topmost, after SessionMiddleware (uses session data) and\nUpdateCacheMiddleware (modifies Vary header).
Before any middleware that may change the response (it sets the\nContent-Length header). A middleware that appears before\nCommonMiddleware and changes the response must reset Content-Length.
Close to the top: it redirects when APPEND_SLASH or\nPREPEND_WWW are set to True.
After SessionMiddleware if you’re using CSRF_USE_SESSIONS.
Before any view middleware that assumes that CSRF attacks have been dealt\nwith.
\nBefore RemoteUserMiddleware, or any\nother authentication middleware that may perform a login, and hence rotate\nthe CSRF token, before calling down the middleware chain.
After SessionMiddleware if you’re using CSRF_USE_SESSIONS.
After SessionMiddleware: uses session storage.
After AuthenticationMiddleware: uses user object.
After SessionMiddleware: can use session-based storage.
After any middleware that modifies the Vary header: that header is used\nto pick a value for the cache hash-key.
ContentSecurityPolicyMiddleware
Can be placed near the bottom, but ensure any middleware that accesses\ncsp_nonce is positioned after it, so the nonce is\nproperly included in the response header.
\nShould be near the bottom as it’s a last-resort type of middleware.
\nShould be near the bottom as it’s a last-resort type of middleware.
\n