SSH, The Secure Shell: The Definitive Guide, 2nd Edition

Chapter 10. A Recommended Setup

We’ve just covered a pile of chapters on SSH configuration: is your head spinning yet? With so many choices, you might be wondering which options you should use. How can system administrators secure their systems most effectively with SSH?

When set up properly, SSH works well and invisibly, but sometimes a good setup takes a few tries. In addition, there are some ways to configure the software that are simply wrong. If you’re not careful, you can introduce security holes into your system.

In this chapter we present a recommended set of options for compilation, server configuration, key management, and client configuration. We assume:

• You’re running SSH on a Unix machine.

• You want a secure system, sometimes at the expense of flexibility. For instance, rather than tell you to maintain your .rhosts files carefully, we recommend disabling Rhosts authentication altogether.

Of course, no single configuration covers all the possibilities; that is, after all, the point of configuration. This is just a sample setup, more on the secure side, to give you a starting point and cover some of the issues involved.