Mastering Linux Security and Hardening

Using extended file attributes to protect sensitive files

Extended file attributes are another tool for helping you to protect sensitive files. They won't keep intruders from accessing your files, but they can help you prevent sensitive files from being altered or deleted. There are quite a few extended attributes, but we only need to look at the ones that deal with file security.

First, let's do an lsattr command to see which extended attributes you already have set. On the CentOS machine, your output would look something like this:

[donnie@localhost ~]$ lsattr---------------- ./yum_list.txt---------------- ./perm_demo.txt---------------- ./perm_demo_dir---------------- ./donnie_script.sh---------------- ./suid_sgid_files.txt---------------- ...