Lesson 12 Date: 6/25/2017

Linux Password Security

Linux System Administration

Setting policies for strong passwords. To make user passwords difficult to crack, password policies such as password length, password complexity, password expiration period should be set on a Linux system. Exercises: Deploy a new VM, centpwd, by cloning CentOS7. On centpwd VM, create user mike4. Follow the tutorial on password policies and complete the following tasks: 1. Set the password length of minimum 10 characters on both cryptvm and centpwd. Test the settings by changing the password for user mike4 on the both VMs. 2. On the both VMs, set the password complexity to have minimum 10 characters with at least 2 upper-case letters, 2 numbers, and 1 "other" letter. Test the settings by changing the password for user mike4 on the both VMs. 3. On the both VMs, set the password expiration date for mike4 to July 10 2017. Also the maximum number of days between password changes should be set to 180 days. 4. On the both VMs, prevent the users to use the last 2 used passwords. Test the settings by changing password for user mike4.

Vectors of attack Passwords MD5 and SHA512 Exercise: mkpasswd Exercise: different encryptions Exercise: password cracking PAM Exercise: password policies. Exercise: two-factor authentication References Take me to the Course Website