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

13

TLS Handshake Protocol Revisited

In previous chapters, you learned about the cryptographic primitives and mechanisms required to understand the inner workings of the TLS 1.3 handshake. Now is a good time to look at the TLS handshake from a bird’s-eye view.

In this chapter, we will zoom out of the cryptographic details and revisit how the individual steps combine in the overall scheme of things. More precisely, we will discuss the TLS handshake protocol with the help of state machines for the TLS server and TLS client specified in RFC 8446. Moreover, we will show you how you can use s˙client, a TLS client program from the popular OpenSSL toolkit, to conduct your own experiments with TLS.

Upon completion of the chapter, you will have a comprehensive understanding of how the individual protocol steps fit together, both on Alice’s and on Bob’s side. In terms of skills acquired, you will gain the following:

  • A good overview of the entire TLS handshake

  • Familiarity...