Summary
In this chapter, we learned about the importance of the TLS protocol, why it is needed, and where it is used. We also learned about how the protocol works on a high level, what is included in the TLS handshake, and what happens after the handshake. We finished the theoretical part by taking a look at the TLS protocol history, learning about its development, and how old and new versions of SSL and TLS differ from each other.
In the practical part of the chapter, we learned how to establish client and server TLS connections, both on the command line and programmatically using C code. We also learned about OpenSSL BIOs.
In the next chapter, we will learn about the more advanced usage of X.509 certificates in TLS, including user-controlled certificate verification and client TLS certificates.
