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

Summary

This chapter was different from the previous ones. In the previous chapters, we covered one big topic per chapter. In this chapter, however, we covered several small topics and wrote more example programs.

In this chapter, we learned about how to verify the peer certificate during a TLS handshake. We also learned about the CRL and OCSP methods. Then, we learned about TLS client certificates and PKCS #12 containers. After that, we learned how to request and verify a TLS client certificate on the server side and how to load and use client certificates on the client side. We finished this chapter by connecting our TLS server and TLS client programs, both of which support TLS client certificates, to each other.

The knowledge you’ve gained from this chapter will help you perform advanced client and server certificate processing on TLS connections in your TLS-enabled programs.

In the next chapter, we will learn about more advanced and special uses of TLS.

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