Book Image

Demystifying Cryptography with OpenSSL 3.0

By : Alexei Khlebnikov
Book Image

Demystifying Cryptography with OpenSSL 3.0

By: Alexei Khlebnikov

Overview of this book

Security and networking are essential features of software today. The modern internet is full of worms, Trojan horses, men-in-the-middle, and other threats. This is why maintaining security is more important than ever. OpenSSL is one of the most widely used and essential open source projects on the internet for this purpose. If you are a software developer, system administrator, network security engineer, or DevOps specialist, you’ve probably stumbled upon this toolset in the past – but how do you make the most out of it? With the help of this book, you will learn the most important features of OpenSSL, and gain insight into its full potential. This book contains step-by-step explanations of essential cryptography and network security concepts, as well as practical examples illustrating the usage of those concepts. You’ll start by learning the basics, such as how to perform symmetric encryption and calculate message digests. Next, you will discover more about cryptography: MAC and HMAC, public and private keys, and digital signatures. As you progress, you will explore best practices for using X.509 certificates, public key infrastructure, and TLS connections. By the end of this book, you’ll be able to use the most popular features of OpenSSL, allowing you to implement cryptography and TLS in your applications and network infrastructure.
Table of Contents (20 chapters)
1
Part 1: Introduction
3
Part 2: Symmetric Cryptography
8
Part 3: Asymmetric Cryptography and Certificates
12
Part 4: TLS Connections and Secure Communication
16
Part 5: Running a Mini-CA

What kind of asymmetric encryption is available in OpenSSL?

The OpenSSL library implements several asymmetric crypto algorithms, but only one of those algorithms allows you to directly encrypt data. It is the Rivest-Shamir-Adleman (RSA) algorithm.

Other available asymmetric crypto algorithms, such as Digital Signature Algorithm (DSA) and Elliptic Curve Digital Signature Algorithm (ECDSA), can be used for digital signatures. Diffie–Hellman (DH) and Elliptic Curve Diffie–Hellman (ECDH) algorithms can be used for key exchange in the Transport Layer Security (TLS) protocol.

As we know, symmetric cryptography keys do not have structure; they are just arrays of random bits. Conversely, asymmetric crypto algorithms use structured keys, meaning that a key can have several components, and a component may have certain requirements – for example, it must be a prime number instead of a random bit array. Each asymmetric crypto algorithm has its own structure of public...