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

22.8 Cloudbleed

In 2017, Tavis Ormandy, a vulnerability researcher in Google’s Project Zero team, reported a security vulnerability in Cloudflare’s edge servers [76]. Cloudflare is a large Content Delivery Network (CDN) that operates a global network of servers that cache and deliver website content to end users from the server location closest to them.

Because of the vulnerability, the software running on Cloudflare’s edge servers – more precisely, an HTML parser – was reading past the end of a buffer and returning contents from the servers’ internal memory such as HTTP cookies, authentication tokens, and the bodies of HTTP POST requests.

Cloudflare reported that during the peak time, a period of about five days, 1 in every 3,300,000 HTTP requests to Cloudflare’s edge servers potentially resulted in a memory leak [76].

The proof of concept by Tavis Ormandy returned private messages from major dating sites, full messages from...