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TLS Record Protocol Revisited

In the previous three chapters, you studied block ciphers and their modes of operation, the AEAD encryption scheme (which aims to provide confidentiality, authenticity, and integrity in a single cryptographic mechanism), and finally the Galois counter mode, a block cipher mode of operation that implements AEAD. It is now time to put these things together.

In this chapter, we will revisit the TLS Record protocol and learn how the preceding cryptographic primitives are combined to protect the payload data transmitted over a TLS connection. In doing this, we will cover Section 5 of the RFC 8446.

We will also get back to OpenSSL’s s˙client to experimentally investigate the TLS record protocol. This time, however, we will use a debugger to take a look at what happens under the hood in OpenSSL and how the plaintext is turned into an encrypted TLS record.

Upon completing this chapter, you will have a good understanding of how the TLS record protocol...