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| Introduction | |
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| This Book's Organization | |
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| How This Book Is Cross-Referenced | |
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| amadmin | |
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| Using This Book | |
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| Odds and Ends | |
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| Summary | |
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| Linux Security Basics | |
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| Introducing Linux | |
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| What Is Linux? | |
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| Linux as a Standalone System | |
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| Linux as an Intranet/Internet Server | |
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| A Linux Security Overview | |
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| Summary | |
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| Physical Security | |
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| Server Location and Physical Access | |
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| Network Topology | |
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| Network Hardware | |
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| Workstations and Security | |
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| Summary | |
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| Installation Issues | |
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| About Various Linux Distributions, Security, and Installation | |
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| Partitions and Security | |
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| Choosing Network Services During Installation | |
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| Boot Loaders | |
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| Summary | |
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| Basic Linux System Administration | |
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| The Basic Idea | |
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| Creating and Managing Accounts | |
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| Performing Administrative Tasks with su | |
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| Access Control | |
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| Permissions and Ownership | |
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| A Closer Look at Groups | |
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| Bringing Down Your System | |
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| Summary | |
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| Linux User Security | |
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| Password Attacks | |
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| What Is a Password Attack? | |
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| How Linux Generates and Stores Passwords | |
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| The Data Encryption Standard (DES) | |
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| Case Study: Cracking Linux Passwords Via Dictionary Attack | |
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| Password Shadowing and the shadow Suite | |
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| After Installing the shadow Suite | |
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| Other Password Security Issues | |
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| Pluggable Authentication Modules | |
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| Still Other Password Security Solutions | |
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| Summary | |
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| Malicious Code | |
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| What Is Malicious Code? | |
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| Detecting Malicious Code | |
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| Other File Integrity Checking Software | |
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| Summary | |
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| Linux Network Security | |
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| Sniffers and Electronic Eavesdropping | |
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| How Sniffers Work | |
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| Case Studies: Performing a Few Simple Sniffer Attacks | |
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| Other Sniffers and Network Monitoring Tools | |
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| Risks Posed by Sniffers | |
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| Defending Against Sniffer Attacks | |
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| Further Reading | |
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| Summary | |
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| Scanners | |
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| What Is a Scanner? | |
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| Scanner Building Blocks and Scanner Evolution | |
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| How Scanners Fit into Your Security Regimen | |
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| Various Scanner Tools | |
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| Defending Against Scanner Attacks | |
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| Interesting Resources | |
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| Summary | |
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| Spoofing | |
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| What Is Spoofing All About? | |
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| TCP and IP Spoofing | |
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| Case Study: A Simple Spoofing Attack | |
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| Preventing IP Spoofing Attacks | |
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| ARP Spoofing | |
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| DNS Spoofing | |
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| Other Strange Spoofing Attacks | |
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| Further Reading | |
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| Summary | |
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| Protecting Data in Transit | |
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| Secure Shell (ssh) | |
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| scp: The Secure Copy Remote File Copy Program | |
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| Providing ssh Services in a Heterogeneous Network | |
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| ssh Security Issues | |
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| Additional Resources | |
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| Summary | |
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| Linux Internet Security | |
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| FTP Security | |
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| File Transfer Protocol | |
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| FTP's Default Security Features | |
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| SSLftp | |
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| Specific FTP Application Security | |
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| Summary | |
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| Mail Security | |
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| SMTP Servers and Clients | |
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| sendmail Security Basics | |
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| Replacing sendmail with Qmail | |
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| Summary | |
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| Telnet Security | |
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| Assessing the Need to Provide Telnet Services | |
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| Telnet's Security History | |
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| Secure Telnet Systems | |
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| deslogin | |
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| SRA Telnet from Texas AandM University | |
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| The Stanford SRP Telnet/FTP Package | |
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| Summary | |
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| Web Server Security | |
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| Eliminating Nonessential Services | |
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| Web Server Security | |
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| Adding Directory Access Control with Basic HTTP | |
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| Weaknesses in Basic HTTP Authentication | |
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| HTTP and Cryptographic Authentication | |
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| Running a chroot Web Environment | |
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| Accreditation and Certification | |
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| Summary | |
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| Secure Web Protocols | |
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| The Problem | |
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| Secure Sockets Layer (SSL) from Netscape Communications Corporation | |
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| Installing Apache-SSL | |
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| Other Secure Protocols: IPSEC | |
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| Summary | |
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| Secure Web Development | |
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| Development Risk Factors: A Wide Overview | |
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| Spawning Shells | |
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| Buffer Overruns | |
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| Paths, Directories, and Files | |
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| Other Interesting Security Programming and Testing Tools | |
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| Other Online Resources | |
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| Summary | |
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| Denial-of-Service Attacks | |
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| What Is a Denial-of-Service Attack? | |
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| Risks Posed by Denial-of-Service Attacks | |
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| How This Chapter Is Laid Out | |
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| Network Hardware DoS Attacks | |
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| Attacks on Linux Networking | |
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| Attacks on Linux Applications | |
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| Other DoS Attacks | |
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| Defending Against Denial-of-Service Attacks | |
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| Online Resources | |
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| Summary | |
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| Linux and Firewalls | |
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| What Is a Firewall? | |
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| Assessing Whether You Really Need a Firewall | |
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| tcpd: TCP Wrappers | |
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| ipfwadm | |
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| ipchains | |
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| Free Firewall Tools and Add-Ons for Linux | |
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| Commercial Firewalls | |
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| Additional Resources | |
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| Summary | |
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| Logs and Audit Trails | |
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| What Is Logging, Exactly? | |
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| Logging in Linux | |
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| Other Interesting Logging and Audit Tools | |
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| Summary | |
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| Intrusion Detection | |
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| What Is Intrusion Detection? | |
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| Basic Intrusion Detection Concepts | |
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| Some Interesting Intrusion Detection Tools | |
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| Disaster Recovery | |
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| What Is Disaster Recovery? | |
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| Steps to Take Before Building Your Linux Network | |
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| Choosing Your Backup Tools | |
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| Simple Archiving: tarring and Zipping Your Files and Directories | |
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| Types of Backups and Backup Strategies | |
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| Backup Packages | |
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| Odds and Ends | |
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| Summary | |
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| Appendixes | |
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| Linux Security Command Reference | |
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| Linux Security Index--Past Linux Security Issues | |
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| Summary | |
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| Other Useful Linux Security Tools | |
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| Sources for More Information | |
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| Linux Security Patches, Updates, and Advisories | |
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| Mailing Lists | |
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| Usenet Newsgroups | |
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| Glossary | |
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| Index | |