How to detect server-side whether cookies are disabled

Question

How can I detect on the server (server-side) whether cookies in the browser are disabled? Is it possible?

Detailed explanation: I am processing an HTTP request on the server. I want to set a cookie via the Set-Cookie header. I need to know at that time whether the cookie will be set by the client browser or my request to set the cookie will be ignored.

Answer 1

Send a redirect response with the cookie set; when processing the (special) redirected URL test for the cookie - if it's there redirect to normal processing, otherwise redirect to an error state.

Note that this can only tell you the browser permitted the cookie to be set, but not for how long. My FF allows me to force all cookies to "session" mode, unless the site is specifically added to an exception list - such cookies will be discarded when FF shuts down regardless of the server specified expiry. And this is the mode I run FF in always.

Answer 2

You can use Javascript to accomplish that

Library:

function createCookie(name, value, days) {
    var expires;
    if (days) {
        var date = new Date();
        date.setTime(date.getTime() + (days * 24 * 60 * 60 * 1000));
        expires = "; expires=" + date.toGMTString();
    }
    else expires = "";
    document.cookie = name + "=" + value + expires + "; path=/";
}

function readCookie(name) {
    var nameEQ = name + "=";
    var ca = document.cookie.split(';');
    for (var i = 0; i < ca.length; i++) {
        var c = ca[i];
        while (c.charAt(0) == ' ') c = c.substring(1, c.length);
        if (c.indexOf(nameEQ) == 0) return c.substring(nameEQ.length, c.length);
    }
    return null;
}

function eraseCookie(name) {
    createCookie(name, "", -1);
}

function areCookiesEnabled() {
    var r = false;
    createCookie("testing", "Hello", 1);
    if (readCookie("testing") != null) {
        r = true;
        eraseCookie("testing");
    }
    return r;
}

Code to run:

alert(areCookiesEnabled());

Remember

This only works if Javascript is enabled!

Answer 3

I dont think there are direct ways to check. The best way is to store a value in the cookie and try to read them and decide whether cookies are enabled or not.

Answer 4

A common way of checking for cookie support is via a redirect.

It's a good idea to only do this when the user is trying to do something that initiates a session, such as logging in, or adding something to their cart. Otherwise, depending on how you handle it, you're potentially blocking access to your entire site for users - or bots - that don't support cookies.

First, the server checks the login data as normal - if the login data is wrong the user receives that feedback as normal. If it's right, then the server immediately responds with a cookie and a redirect to a page which is designed to check for that cookie - which may just be the same URL but with some flag added to the query string. If that second page doesn't receive the cookie, then the user receives a message stating that they cannot log in because cookies are disabled on their browser.

If you're following the Post-Redirect-Get pattern for your login form already, then this setting and checking of the cookie does not add any additional requests - the cookie can be set during the existing redirect, and checked by the destination that loads after the redirect.

Now for why I only do a cookie test after a user-initiated action other than on every page load. I have seen sites implement a cookie test on every single page, not realising that this is going to have effects on things like search engines trying to crawl the site. That is, if a user has cookies enabled, then the test cookie is set once, so they only have to endure a redirect on the first page they request and from then on there are no redirects. However, for any browser or other user-agent, like a search engine, that doesn't return cookies, every single page could simply result in a redirect.

Another method of checking for cookie support is with Javascript - this way, no redirect is necessarily needed - you can write a cookie and read it back virtually immediately to see if it was stored and then retrieved. The downside to this is it runs in script on the client side - ie if you still want the message about whether cookies are supported to get back to the server, then you still have to organise that - such as with an Ajax call.

For my own application, I implement some protection for 'Login CSRF' attacks, a variant of CSRF attacks, by setting a cookie containing a random token on the login screen before the user logs in, and checking that token when the user submits their login details. Read more about Login CSRF from Google. A side effect of this is that the moment they do log in, I can check for the existence of that cookie - an extra redirect is not necessary.

Answer 5

Usually, you might only need to check for cookie support after the user has taken some action on the site, such as submitting a login form, adding an item to their cart, and so on.

For me currently, checking for cookie support goes hand-in-hand with CSRF (Cross-Site Request Forgery) prevention.

You should probably go elsewhere to read more about CSRF, but the idea behind it is that other sites may trick or your users into submitting a hidden form of their choosing to your own site. The way around this is to set a cookie when the viewer sees a form, and set a matching token as a hidden form element, and then when processing the form, check that both the cookie and hidden form element were set and match each other. If it is an attempted CSRF attack, the site won't be able to provide the hidden field to match the user's cookie, because the user's cookie won't be readable to them under the same-origin policy.

If a form is submitted having no cookie, but it does contain a valid-looking token, then you can conclude from this that the user has cookies disabled and throw up a message indicating that the user should enable cookies and re-try. The other possibility, of course, is that the user is the victim of an attempted CSRF attack. So blocking the user when the cookie doesn't match will also have the side-effect of preventing that attack.

Answer 6

Try to store something into a cookie, and then read it. If you don't get what you expect, then cookies are probably disabled.

Answer 7

I always used this:

navigator.cookieEnabled

According to w3schools "The cookieEnabled property is supported in all major browsers.".

However, this works for me when i am using forms, where i can instruct the browser to send the additional information.

Answer 8

check this code , it' will help you .

<?php
session_start();

function visitor_is_enable_cookie() {
    $cn = 'cookie_is_enabled';
    if (isset($_COOKIE[$cn]))
        return true;
    elseif (isset($_SESSION[$cn]) && $_SESSION[$cn] === false)
        return false;

    // saving cookie ... and after it we have to redirect to get this
    setcookie($cn, '1');
    // redirect to get the cookie
    if(!isset($_GET['nocookie']))
        header("location: ".$_SERVER['REQUEST_URI'].'?nocookie') ;

    // cookie isn't availble
    $_SESSION[$cn] = false;
    return false;
}

var_dump(visitor_is_enable_cookie());

Answer 9

NodeJS - Server Side - Cookie Check Redirect Middleware - Express Session/Cookie Parser

Dependencies

var express = require('express'),
    cookieParser = require('cookie-parser'),
    expressSession = require('express-session')

Middleware

return (req, res, next) => {
  if(req.query.cookie && req.cookies.cookies_enabled)
    return res.redirect('https://yourdomain.io' + req.path)
  if(typeof(req.cookies.cookies_enabled) === 'undefined' && typeof(req.query.cookie) === 'undefined') {
    return res.cookie('cookies_enabled', true, {
      path: '/',
      domain: '.yourdomain.io',
      maxAge: 900000, 
      httpOnly: true,
      secure: process.env.NODE_ENV ? true : false
    }).redirect(req.url + '?cookie=1')
  }
  if(typeof(req.cookies.cookies_enabled) === 'undefined') {
    var target_page = 'https://yourdomain.io' + (req.url ? req.url : '')
    res.send('You must enable cookies to view this site.<br/>Once enabled, click <a href="' + target_page + '">here</a>.')
    res.end()
    return
  }
  next()
}

Answer 10

I'm using a much more simplified version of "balexandre"'s answer above. It tries to set, and read a session cookie for the sole purpose of determining if cookies are enabled. And yes, this requires that JavaScript is enabled as well. So you may want a tag in there if you care to have one.

<script>
// Cookie detection
document.cookie = "testing=cookies_enabled; path=/";
if(document.cookie.indexOf("testing=cookies_enabled") < 0)
{
    // however you want to handle if cookies are disabled
    alert("Cookies disabled");
}
</script>
<noscript>
    <!-- However you like handling your no JavaScript message -->
    <h1>This site requires JavaScript.</h1>
</noscript>

Answer 11

The question whether cookies are "enabled" is too boolean. My browser (Opera) has a per-site cookie setting. Furthermore, that setting is not yes/no. The most useful form is in fact "session-only", ignoring the servers' expiry date. If you test it directly after setting, it will be there. Tomorrow, it won't.

Also, since it's a setting you can change, even testing whether cookies do remain only tells you about the setting when you tested. I might have decided to accept that one cookie, manually. If I keep being spammed, I can (and at times, will) just turn off cookies for that site.

Answer 12

If you only want to check if session cookies (cookies that exist for the lifetime of the session) are enabled, set your session mode to AutoDetect in your web.config file, then the Asp.Net framework will write a cookie to the client browser called AspxAutoDetectCookieSupport. You can then look for this cookie in the Request.Cookies collection to check if session cookies are enabled on the client.

E.g. in your web.config file set:

<sessionState cookieless="AutoDetect" />

Then check if cookies are enabled on the client with:

if (Request.Cookies["AspxAutoDetectCookieSupport"] != null)  { ... }

Sidenote: By default this is set to UseDeviceProfile, which will attempt to write cookies to the client so long as the client supports them, even if cookies are disabled. I find it slightly odd that this is the default option as it seems sort of pointless - sessions won't work with cookies disabled in the client browser with it set to UseDeviceProfile, and if you support cookieless mode for clients that don't support cookies, then why not use AutoDetect and support cookieless mode for clients that have them disabled...

Answer 13

The cookieEnabled property returns a Boolean value that specifies whether or not cookies are enabled in the browser

<script>
if (navigator.cookieEnabled) {
    // Cookies are enabled
}
else {
    // Cookies are disabled
}
</script>

Answer 14

Use navigator.CookieEnabled for cookies enabled(it will return true of false) and the Html tag noscript. By the way navigator.cookieEnabled is javascript so don't type it in as HTML

Answer 15

<?php   session_start();
if(SID!=null){
  echo "Please enable cookie";
}
?>