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

13.7 Summary

In this chapter, we looked at the TLS handshake protocol from a bird’s-eye view, with the help of TLS client and server state machines. The state machines illustrate how the TLS protocol works on a higher level. In addition, we covered the Finished message and several post-handshake messages in more detail.

We also learned how to use OpenSSL, a popular cryptography and TLS toolkit, and, especially, the s˙client OpenSSL tool to experiment with TLS. We discussed how to install and how to use s˙client and presented several experiments that you can reproduce and enhance on your own. These experiments allow you to observe TLS at work and take a close look at cryptographic mechanisms and TLS features used in the handshake protocol.

This chapter concludes the second part of the book. In the next part, we will study the TLS record protocol. The record protocol protects application data using shared secret keys established during the TLS handshake. We will start...