Certbot offers a variety of ways to validate your domain, fetch certificates, and automatically configure Apache and Nginx. In this tutorial, we’ll discuss Certbot’s standalone mode and how to use it to secure other types of services, such as a mail server or a message broker like RabbitMQ.
SSL is based on the mathematical intractability of resolving a large integer into its also-large prime factors. Using this, we can encrypt information using what’s called a “private-public key pair”. Certificate authorities can issue SSL certificates that verify the authenticity of such a secured connection, and on the same note, a self-signed certificate can be produced without third-party support. By the end of the tutorial, you will have a web server accessible via HTTPS using a self-signed certificate.