Part 2: Symmetric Cryptography

In this part, we will learn about symmetric cryptography and its accompanying technologies, such as cryptographically strong message digests, message authentication codes, and generating symmetric cryptographic keys from passwords. This section contains a review of the symmetric ciphers, such as AES and ChaCha, and message digest algorithms, such as SHA-256, supported by OpenSSL. The usage of all the technologies mentioned will be illustrated using command-line and C code examples. We will learn how to initialize and un-initialize OpenSSL and will write our first programs that use the OpenSSL library.

This part contains the following chapters:

• Chapter 2, Symmetric Encryption and Decryption
• Chapter 3, Message Digests
• Chapter 4, MAC and HMAC
• Chapter 5, Derivation of an Encryption Key from a Password