Lesson 10

Date: 4/2/2014

Basics of Linux Security

Linux for Engineering and IT Applications

Exercise: Using GNUtar for consistensy check
You already have downloaded file openssh-4.4p1.tar.gz in the GPG exercises. Unzip and untar the archive and then tar it again so tar assign your ownership to the files in the new archive:

   gunzip openssh-4.4p1.tar.gz 
   tar -xvf openssh-4.4p1.tar 
   tar -cvf openssh-4.4p1.tar openssh-4.4p1

Consistency check:

  tar -df openssh-4.4p1.tar openssh-4.4p1

It should show you nothing since the archive contains files with identical attributes.
Edit file openssh-4.4p1/ChangeLog and create a new line in it. Run the consistency check again:

   tar -df openssh-4.4p1.tar openssh-4.4p1

See the results: 'Mod time differs', 'Size differs'

Fundamentals of Linux security
How systems get compromised
Trojan script exercise
Stack overflow
Package upgrades and verification
Open Ports List exercise
Closing Ports
TCP Wrappers exercise
IP filtering firewalls (iptables)
Building iptables rules
Simple iptables script
NAT table
NAT script
Exercises with iptables
Port scanning exercises
GNU Privacy Guard
GPG exercises
Logs
System Integrity checks
GNUtar exercises
References
Take me to the Course Website