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

Overview of digital signature algorithms supported by OpenSSL

In this section, we will review the digital signature algorithms that are supported by OpenSSL and give some recommendations on which algorithms to use.

Reviewing RSA

The Rivest-Shamir-Adleman (RSA) algorithm was invented by Ronald Rivest, Adi Shamir, and Leonard Adleman. Ronald Rivest is the same person who invented symmetric encryption algorithms from the RC family and message digest algorithms from the MD family. The RSA algorithm was first published in 1977. It was the first popular asymmetric crypto algorithm.

RSA is quite a universal algorithm since it can both encrypt and sign messages. RSA is the slowest algorithm to sign but the fastest to verify for the same security level among the digital signature algorithms provided by OpenSSL.

The speed of both signing and verification depends on the key size. The signing speed quickly drops with the growth of the key size. The verification speed also drops, but...