User guide

Security Guide
iv
2.4.2. Openswan ....................................................................................................... 67
2.5. Firewalls .................................................................................................................... 69
2.5.1. Netfilter and IPTables ....................................................................................... 71
2.5.2. Basic Firewall Configuration ............................................................................. 71
2.5.3. Using IPTables ................................................................................................ 74
2.5.4. Common IPTables Filtering .............................................................................. 75
2.5.5. FORWARD and NAT Rules ................................................................................. 76
2.5.6. Malicious Software and Spoofed IP Addresses .................................................. 79
2.5.7. IPTables and Connection Tracking .................................................................... 79
2.5.8. IPv6 ................................................................................................................ 80
2.5.9. Additional Resources ....................................................................................... 80
2.6. IPTables ..................................................................................................................... 81
2.6.1. Packet Filtering ................................................................................................ 81
2.6.2. Command Options for IPTables ........................................................................ 83
2.6.3. Saving IPTables Rules ..................................................................................... 91
2.6.4. IPTables Control Scripts ................................................................................... 92
2.6.5. IPTables and IPv6 ........................................................................................... 94
2.6.6. Additional Resources ....................................................................................... 94
3. Encryption 95
3.1. Data at Rest .............................................................................................................. 95
3.2. Full Disk Encryption .................................................................................................... 95
3.3. File Based Encryption ................................................................................................. 95
3.4. Data in Motion ........................................................................................................... 95
3.5. Virtual Private Networks .............................................................................................. 96
3.6. Secure Shell .............................................................................................................. 96
3.7. OpenSSL PadLock Engine .......................................................................................... 96
3.8. LUKS Disk Encryption ................................................................................................ 97
3.8.1. LUKS Implementation in Red Hat Enterprise Linux ............................................ 97
3.8.2. Manually Encrypting Directories ........................................................................ 98
3.8.3. Step-by-Step Instructions ................................................................................. 98
3.8.4. What you have just accomplished. .................................................................... 99
3.8.5. Links of Interest ............................................................................................... 99
3.9. Using GNU Privacy Guard (GnuPG) ............................................................................ 99
3.9.1. Creating GPG Keys in GNOME ........................................................................ 99
3.9.2. Creating GPG Keys in KDE ............................................................................. 99
3.9.3. Creating GPG Keys Using the Command Line ................................................. 100
3.9.4. About Public Key Encryption .......................................................................... 101
4. General Principles of Information Security 103
4.1. Tips, Guides, and Tools ............................................................................................ 103
5. Secure Installation 105
5.1. Disk Partitions .......................................................................................................... 105
5.2. Utilize LUKS Partition Encryption ............................................................................... 105
6. Software Maintenance 107
6.1. Install Minimal Software ............................................................................................ 107
6.2. Plan and Configure Security Updates ........................................................................ 107
6.3. Adjusting Automatic Updates ..................................................................................... 107
6.4. Install Signed Packages from Well Known Repositories .............................................. 107
7. Federal Standards and Regulations 109
7.1. Introduction .............................................................................................................. 109
7.2. Federal Information Processing Standard (FIPS) ........................................................ 109
7.3. National Industrial Security Program Operating Manual (NISPOM) ............................... 110