Book Image

TLS Cryptography In-Depth

By : Dr. Paul Duplys, Dr. Roland Schmitz
Book Image

TLS Cryptography In-Depth

By: Dr. Paul Duplys, Dr. Roland Schmitz

Overview of this book

TLS is the most widely used cryptographic protocol today, enabling e-commerce, online banking, and secure online communication. Written by Dr. Paul Duplys, Security, Privacy & Safety Research Lead at Bosch, and Dr. Roland Schmitz, Internet Security Professor at Stuttgart Media University, this book will help you gain a deep understanding of how and why TLS works, how past attacks on TLS were possible, and how vulnerabilities that enabled them were addressed in the latest TLS version 1.3. By exploring the inner workings of TLS, you’ll be able to configure it and use it more securely. Starting with the basic concepts, you’ll be led step by step through the world of modern cryptography, guided by the TLS protocol. As you advance, you’ll be learning about the necessary mathematical concepts from scratch. Topics such as public-key cryptography based on elliptic curves will be explained with a view on real-world applications in TLS. With easy-to-understand concepts, you’ll find out how secret keys are generated and exchanged in TLS, and how they are used to creating a secure channel between a client and a server. By the end of this book, you’ll have the knowledge to configure TLS servers securely. Moreover, you’ll have gained a deep knowledge of the cryptographic primitives that make up TLS.
Table of Contents (30 chapters)
1
Part I Getting Started
8
Part II Shaking Hands
16
Part III Off the Record
22
Part IV Bleeding Hearts and Biting Poodles
27
Bibliography
28
Index

17.8 Summary

In this chapter, we covered the TLS record layer and learned how cryptographic mechanisms, in particular AEAD algorithms, are used in the TLS record protocol. We described the data structures and messages on the record layer and saw how record payloads are protected. In addition, we discussed per-record nonces and the use of padding for TLS records.

Moreover, we covered how TLS can be further explored – down to nitty-gritty details – by debugging OpenSSL, specifically OpenSSL’s s˙client test tool. While we did not describe the GNU debugger in detail, the Git repository and instructions for building a Docker image with an OpenSSL 3.1.0 installation suitable for debugging and the GDB commands shown in the examples in this chapter are good starting points for exploring OpenSSL and TLS in more detail.

In the next chapter, we will take a look at TLS 1.3 cipher suites. These are pairs composed of an AEAD algorithm and a hash algorithm to be used with...