Authenticating connections

In conjunction with establishing client session objects, a Node server often demands authentication credentials. The theory and practice of web security is extensive.
We want to simplify our understanding into two main authentication scenarios:

• When the wire protocol is HTTPS
• When it is HTTP

The first is naturally secure, and the second is not. For the first, we will learn how to implement Basic authentication in Node, and for the second, a challenge-response system will be described.

Basic authentication

As mentioned, Basic authentication sends plain text over the wire containing a username/password combination, using standard HTTP headers. It is a simple and well-known protocol. Any server sending...