Express protected cookie

Middleware for express to protect cookie making it HttpOnly. Also this Middleware adds flag to check for presence of this property (NOT HttpOnly).

npm install express-limiter --save

'use strict'

var express = require('express')
var protectedCookie = require('protected-cookie');

app = express();
app.use(protectedCookie('check'));
...

Use case

You want to implement authorization and store auth_token in cookie. But if it will not be HttpOnly, your client side can be subjected to XSS. In other way you want to check if cookie is set on client side.

Solution - use this middleware. Server checks your cookie and validate it for each request. But on client side you will have access to check your cookie is set or not.

API options

  protectedCookie(flag)

• flag: String optional wich set flag to cookie name with '_' delimiter (if cookie name is token, then existance flag name will be token_exists which is true or false)

Methods

Middleware add methods protectedCookie and clearProtectedCookie for using instead of cookie and clearCookie with the same parameters. You can check it here Express api. But when you set some cookie in this way, method protectedCookie adds this cookie with HttpOnly option for inaccessibility by javascript and also adds existance flag of this cookie with HttpOnly set to false for access.

Example

If you set cookie by this way

  function(req, res, next) {
    ...
    res.protectedCookie('auth_token', 'value');
    ...
  }

You will get next result in cookie

  auth_token = 'value', // which is HttpOnly
  auth_token_exists = true // which is NOT HttpOnly for access on client side

Method clearProtectedCookie clears both auth_token and auth_token_exists keys from cookie.