Part I: SSL/TLS and PKI

The first part, chapters 1 through 4, lays out the foundations with a discussion of cryptography, SSL, TLS, and PKI.

Chapter 1, SSL, TLS, and Cryptography, begins with an introduction to SSL and TLS and discusses where these secure protocols fit in the Internet infrastructure. The remainder of the chapter provides an introduction to cryptography and discusses the classic threat model of the active network attacker.

Chapter 2, TLS 1.3, focuses on the most recent TLS protocol revision. At the time of writing, TLS 1.3 is well supported by both clients and servers, and widely used. This is the chapter you should read to understand how things work today.

Chapter 3, TLS 1.2, discusses previous major revision, TLS 1.2, which is still very relevant and needed in practice. Understanding this protocol is also very useful to understand what improvements were made in TLS 1.3 and why. Information about earlier protocol revisions is provided where appropriate. An overview of the protocol evolution from SSL 3 onwards is included at the end for reference.

Chapter 4, Public Key Infrastructure, is an introduction to Internet PKI, which is the predominant trust model used on the Internet today. The focus is on the standards and organizations as well as governance, ecosystem weaknesses and possible future improvements. This chapter now includes coverage of Certificate Transparency.

Part II: Problems and Attacks

The second part, chapters 5 through 8, details the various problems with trust infrastructure, our security protocols, and their implementations in libraries and programs.

Chapter 5, Attacks against PKI, deals with attacks on the trust ecosystem. It covers all the major CA compromises, detailing the weaknesses, attacks, and consequences. This chapter gives a thorough historical perspective on the security of the PKI ecosystem, which is important for understanding its evolution.

Chapter 6, HTTP and Browser Issues, is all about the relationship between HTTP and TLS, the problems arising from the organic growth of the Web, and the messy interactions between different pieces of the web ecosystem.

Chapter 7, Implementation Issues, deals with issues arising from design and programming mistakes related to random number generation, certificate validation, and other key TLS and PKI functionality. In addition, it discusses voluntary protocol downgrade and truncation attacks, as well as high-profile issues, such as Heartbleed, FREAK, and Logjam.

Chapter 8, Protocol Attacks, is the longest chapter in the book. It covers all the major protocol flaws discovered in recent years: insecure renegotiation, BEAST, CRIME, Lucky 13, POODLE and POODLE TLS, RC4, TIME and BREACH, and Triple Handshake Attack. The newer ROBOT and Raccoon attacks are also there, among others. A brief discussion of Bullrun and its impact on the security of TLS is also included.

Part III: Deployment and Development

The third part, chapters 9 through 11, provides comprehensive advice about deploying TLS in a secure and efficient fashion.

Chapter 9, Performance, focuses on the speed of TLS, going into great detail about various performance improvement techniques for those who want to squeeze every bit of speed out of their servers.

Chapter 10, HSTS, CSP, and Pinning, covers some advanced topics that strengthen web applications, such as HTTP Strict Transport Security and Content Security Policy. It also covers pinning, which is an effective way of reducing the large attack surface imposed by our current PKI model.

Chapter 11, TLS Configuration Guide, is the map for the entire book and provides step-by-step instructions on how to deploy secure and well-performing TLS servers and web applications. This chapter has effectively been rewritten for the second edition

Part IV: OpenSSL Command-Line

The fourth and final part consists of chapters 12 and 13, which focus on OpenSSL, the de facto standard for everyday TLS and PKI work on the command line.

Chapter 12, OpenSSL, describes the most frequently used OpenSSL functionality, with a focus on installation, configuration, and key and certificate management. The last section in this chapter provides instructions on how to construct and manage a private certification authority.

Chapter 13, Testing with OpenSSL, continues with OpenSSL and explains how to use its command-line tools to test server configuration. Even though it’s often much easier to use an automated tool for testing, OpenSSL remains the tool you turn to when you want to be sure about what’s going on.