Book Image

Essential Cryptography for JavaScript Developers

By : Alessandro Segala
Book Image

Essential Cryptography for JavaScript Developers

By: Alessandro Segala

Overview of this book

If you’re a software developer, this book will give you an introduction to cryptography, helping you understand how to make the most of it for your applications. The book contains extensive code samples in JavaScript, both for Node.js and for frontend apps running in a web browser, although the core concepts can be used by developers working with any programming language and framework. With a purely hands-on approach that is focused on sharing actionable knowledge, you’ll learn about the common categories of cryptographic operations that you can leverage in all apps you’re developing, including hashing, encryption with symmetric, asymmetric and hybrid ciphers, and digital signatures. You’ll learn when to use these operations and how to choose and implement the most popular algorithms to perform them, including SHA-2, Argon2, AES, ChaCha20-Poly1305, RSA, and Elliptic Curve Cryptography. Later, you’ll learn how to deal with password and key management. All code in this book is written in JavaScript and designed to run in Node.js or as part of frontend apps for web browsers. By the end of this book, you'll be able to build solutions that leverage cryptography to protect user privacy, offer better security against an expanding and more complex threat landscape, help meet data protection requirements, and unlock new opportunities.
Table of Contents (13 chapters)
1
Part 1 – Getting Started
4
Part 2 – Using Common Cryptographic Operations with Node.js
9
Part 3 – Cryptography in the Browser

Conventions used

There are a number of text conventions used throughout this book.

Code in text: Indicates code words in text, database table names, folder names, filenames, file extensions, pathnames, dummy URLs, user input, and Twitter handles. Here is an example: " We use the decipher object, just like we did with the cipher object in the previous method, invoking decipher.update with the ciphertext to decrypt and use decipher.final when we're done."

A block of code is set as follows:

const crypto = require('crypto')
const fs = require('fs')
const util = require('util')
const readFile = util.promisify(fs.readFile)

When we wish to draw your attention to a particular part of a code block, the relevant lines or items are set in bold:

    const bobPublicKeyPem = bobKeyPair.publicKey.export(
        {type: 'spki', format: 'pem'}
    )
    const aliceSharedSecret = crypto.diffieHellman({
        publicKey: crypto.createPublicKey(bobPublicKeyPem),
        privateKey: aliceKeyPair.privateKey
    })

Any command-line input or output is written as follows:

$ openssl genrsa -out private.pem 4096

Bold: Indicates a new term, an important word, or words that you see onscreen. For instance, words in menus or dialog boxes appear in bold. Here is an example: "Select System info from the Administration panel."

Tips or Important Notes

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