Peter G. Smith
1 lots of info
despite its smallish size (550 pages) this book is packed full of useful info. the first couple of chapters are a whistle stop tour of the all the ways a linux box can be hacked, and the rest of the book describes how to fix these problems. most of the book is intermediate level, but a couple of the later chapters are more advanced. but i think this is a good thing because it means the book goes into much more detail than most others.
2 Includes a Great Deal of Useful Software
Security is one of those things that everyone knows they should do but typically doesn't until too late. In spite of all the warnings most companies ignore the pleadings of the assigned security specialist until all of a sudden they are hit in the face with a penetration. And this is the theme of the introductory chapter, except that he explains it a lot better.
The second chapter starts with an explanation of John The Ripper. This is a program that attempts to automatically crack your system's password file. (The John The Ripper program is included on the books CD so you can use it to test your own system.)
By this point he had my attention. It was clear that if he wished he could get into my system and do whatever he wished. I interrupted my reading at this point and changed several system passwords to make them a lot more difficult.
After that I went on to read the rest of the book on finding, fixing and preventing holes in a Linux network. I never realized it was so easy.
The book is a combined explanation of what's happening and a wealth of software on the CD. This software, described in the text part of the book, is a selection of software off of the net. The net has a huge amount of software available. Here the author has selected a dozen or so packages that he discusses enough for you to use and to have some faith that the results you are getting are worthwhile.
Perhaps the best book on Linux security ever.
