In this recipe, we will learn how to create self-signed Secure Sockets Layer (SSL) certificates using the OpenSSL toolkit. SSL is a technology used to encrypt messages between two ends of a communication (for example, a server and client) so that a third-party cannot read the messages sent between them. Certificates are not used for encrypting the data, but they are very important in this communication process to ensure that the party you are communicating with is exactly the one you suppose it to be. Without them, impersonation attacks would be much more common.
To complete this recipe, you will require a working installation of the CentOS 7 operating system with root privileges and a console-based text editor of your choice.