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

Preface

Welcome to the second edition of our book on SSH, one of the world’s most popular approaches to computer network security. Here’s a sampling of what’s new in this edition:

• Over 100 new features, options, and configuration keywords from the latest versions of OpenSSH and SSH Tectia (formerly known as SSH Secure Shell or SSH2 from ssh.com)

• Expanded material on the SSH-2 protocol and its internals, including a step-by-step tour through the transport, authentication, and connection phases

• Running OpenSSH on Microsoft Windows and Macintosh OS X

• All-new chapters on Windows software such as Tectia, SecureCRT, and PuTTY

• Scalable authentication techniques for large installations, including X.509 certificates

• Single sign-on between Linux and Windows via Kerberos/GSSAPI

• Logging and debugging in greater depth

• Tectia’s metaconfiguration, subconfiguration, and plugins, with examples

...and much more! You might be surprised at how much is changed, but in the past four years, SSH has significantly evolved:

SSH-2 protocol triumphant

Back in 2001, only a handful of SSH products supported the relatively new SSH-2 protocol, and the primary implementation was commercial. Today, the old SSH-1 protocol is dying out and all modern SSH products, free and commercial, use the more secure and flexible SSH-2 protocol. We now recommend that everyone avoid SSH-1.

The rise of OpenSSH

This little upstart from the OpenBSD world has become the dominant implementation of SSH on the Internet, snatching the crown from the ...