This book provides you with comprehensive knowledge about Linux Security. The book is aimed at readers who are familiar with Linux concepts but now want to gain a solid foundation in Linux security features. It is assumed these readers already understand some Linux and networking concepts, such as network protocols, network servers, and so on. This book contains detailed information to help you fortify your Linux environment and provides questions that enable you to check your understanding at the end of key chapters.
Chapters 1 through 5 cover security basics in the Linux environment. These chapters give you an overview of Linux security, covering the precautions to be taken while installing and administering Linux. This part of the book also gives you an overview of the various authentication and encryption techniques you can use to protect your data.
Chapters 6 through 9 deal with securing networks in the Linux environment. Various kinds of possible network attacks are discussed in this part of the book, and you are given guidelines for preventing these attacks. Securing network servers—such as Apache Web server, FTP server, Sendmail, DNS, and SAMBA—is the core of this second part of the book.
Chapters 10 through 13 focus on preventing intrusion and data recovery. In these chapters, you are provided with an extensive list of signs of intrusions. You will learn to use various tools and security utilities to detect and avoid intrusion.
Maintaining logs regularly is a good practice for system administrators. Logs can give you indications of methods used to attack your system, and at times, you can get information about the attacker as well. Chapter 12, “System Logs,”educates you about using logs. In the last chapter of the book, I discuss the importance of making backups. You’ll realize how important backups are if you ever lose data due to system crashes or other reasons. Various commercial and non-commercial tools that you can use to maintain backups are discussed in this chapter.
Finally, this book also includes several appendices. The appendices include best Linux practices and FAQs for Linux security. An appendix on the future of Linux also is included at the end of the book.