Limiting the login capabilities of users

A major role of a system administrator is to configure and manage users and groups on a Linux system. It also involves the task of checking the login capabilities of all users.

Getting ready

All the steps given below have been tried on an Ubuntu system; however, you can also follow these on any other Linux distribution.

How to do it...

Here we will discuss how the login capabilities of users can be restricted on a Linux system:

1. We can restrict the access of a user account by changing the login shell of the account to a special value in the /etc/passwd file. Let's check the details of an account, sslh as an example, in the /etc/passwd file, as shown:

   cat /etc/passwd | grep sslh
   

   
2. In the preceding details, the final value for the sslh account is set to /bin/false. If we now try to log in to sslh user as root, we see that we are not able to do so:

   su sslh
   

3. So now, if we change the shell of the user account we wish to restrict, we can do so as shown:
   
4. Another...