Skip to main content

NodeJS Security Headers: 101

Author profile picture

@akash_tomar

Bio is WIP
When we talk about security wrt any web application its a multiple dimensional thing it will involve a number of different aspects:
  • Form validations
  • Response headers and Content Security Policy 
  • Transport layer encryption (https)
  • Cross Site Request Forgery Tokens/ JWTs
These are just a few there would be others as well if you have SSO integration and other features as per your use case.
Today, lets just look into the setting response headers and CSP for most generic applications. 
Default response headers of a basic NodeJS application will look like:
To start with a good base setting let's look into the helmet package. It has a good number of middlewares for setting http headers.
npm i helmet // to install helmet
const helmet = require(‘helmet’);
app.use(helmet());
Just using these two lines of code your response will look like:
One must be careful while setting these since misconfigured headers can cause more harm than good. For instance if you look into the X-DNS-Prefetch-Controlheader.
DNS prefetch greatly improves performance of your web page since it resolves DNS names even before the user actually clicks on the link, but it is considered as a information leakage vulnerability if you are creating a banking project so its better to turn it off.
Other header that helmet gives you by default are:
  • X-Frame-Options
  • Strict-Transport-Security
  • X-Download-Options
  • X-Content-Type-Options
  • X-XSS-Protection
Now that are look into something that is interesting and equally tricky, Content Security Policy
Modern web browsers allow you to restrict resources that are loaded using the Content-Security-Policy headers. It can be used to reduce risk of cross-site-scripting and click-jacking.
A very basic code example for using these header would be:
app.use(helmet.contentSecurityPolicy({
directives: {
      defaultSrc: ["'self'"],
      styleSrc: ["'self'"],
      scriptSrc: ["'self'", "'unsafe-inline'"],
    }
}));
For the above code snippet header will look like:
default-src 'self'; style-src 'self'; script-src 'self' 'unsafe-inline'
To find more details for other directive 

Comments

Post a Comment

Popular posts from this blog

4 Ways to Communicate Across Browser Tabs in Realtime

1. Local Storage Events You might have already used LocalStorage, which is accessible across Tabs within the same application origin. But do you know that it also supports events? You can use this feature to communicate across Browser Tabs, where other Tabs will receive the event once the storage is updated. For example, let’s say in one Tab, we execute the following JavaScript code. window.localStorage.setItem("loggedIn", "true"); The other Tabs which listen to the event will receive it, as shown below. window.addEventListener('storage', (event) => { if (event.storageArea != localStorage) return; if (event.key === 'loggedIn') { // Do something with event.newValue } }); 2. Broadcast Channel API The Broadcast Channel API allows communication between Tabs, Windows, Frames, Iframes, and  Web Workers . One Tab can create and post to a channel as follows. const channel = new BroadcastChannel('app-data'); channel.postMessage(data); And oth...
Post a Comment
Read more

Certbot SSL configuration in ubuntu

  Introduction Let’s Encrypt is a Certificate Authority (CA) that provides an easy way to obtain and install free  TLS/SSL certificates , thereby enabling encrypted HTTPS on web servers. It simplifies the process by providing a software client, Certbot, that attempts to automate most (if not all) of the required steps. Currently, the entire process of obtaining and installing a certificate is fully automated on both Apache and Nginx. In this tutorial, you will use Certbot to obtain a free SSL certificate for Apache on Ubuntu 18.04 and set up your certificate to renew automatically. This tutorial will use a separate Apache virtual host file instead of the default configuration file.  We recommend  creating new Apache virtual host files for each domain because it helps to avoid common mistakes and maintains the default files as a fallback configuration. Prerequisites To follow this tutorial, you will need: One Ubuntu 18.04 server set up by following this  initial ...
Post a Comment
Read more

Working with Node.js streams

  Introduction Streams are one of the major features that most Node.js applications rely on, especially when handling HTTP requests, reading/writing files, and making socket communications. Streams are very predictable since we can always expect data, error, and end events when using streams. This article will teach Node developers how to use streams to efficiently handle large amounts of data. This is a typical real-world challenge faced by Node developers when they have to deal with a large data source, and it may not be feasible to process this data all at once. This article will cover the following topics: Types of streams When to adopt Node.js streams Batching Composing streams in Node.js Transforming data with transform streams Piping streams Error handling Node.js streams Types of streams The following are four main types of streams in Node.js: Readable streams: The readable stream is responsible for reading data from a source file Writable streams: The writable stream is re...
Post a Comment
Read more