Red Hat System Administration I

Log in to serverb as the student user.

[student@workstation ~]$ ssh student@serverb
...output omitted...
[student@serverb ~]$

Generate SSH keys for the student user. Do not protect the private key with a passphrase. Name the private and public key files /home/student/.ssh/review3_key and /home/student/.ssh/review3_key.pub respectively.

[student@serverb ~]$ ssh-keygen
Generating public/private rsa key pair.
Enter file in which to save the key (/home/student/.ssh/id_rsa): /home/student/.ssh/review3_key
Enter passphrase (empty for no passphrase): Enter
Enter same passphrase again: Enter
Your identification has been saved in /home/student/.ssh/review3_key.
Your public key has been saved in /home/student/.ssh/review3_key.pub.
The key fingerprint is:
SHA256:Uqefehw+vRfm94fQZDoz/6IfNYSLK/OpiQ4n6lrKIbY student@serverb.lab.example.com
The key's randomart image is:
+---[RSA 3072]----+
| .+=oBo+         |
| ...O * =        |
|.. + % =         |
|. +.B =.         |
|...*..o S        |
|E.=. o + .       |
|  .= oo o .      |
|    *... .       |
|     .oo.        |
+----[SHA256]-----+

Configure the student user on servera to accept logins that are authenticated by the review3_key SSH key pair. The student user on serverb should be able to log in to servera by using SSH without entering a password.

1. Export the review3_key public key to servera from serverb.

   [student@serverb ~]$ ssh-copy-id -i .ssh/review3_key.pub student@servera
   /usr/bin/ssh-copy-id: INFO: Source of key(s) to be installed: ".ssh/review3.pub"
   /usr/bin/ssh-copy-id: INFO: attempting to log in with the new key(s), to filter out any that are already installed
   /usr/bin/ssh-copy-id: INFO: 1 key(s) remain to be installed -- if you are prompted now it is to install the new keys
   student@servera's password: student
   
   Number of key(s) added: 1
   
   Now try logging into the machine, with:   "ssh 'student@servera'"
   and check to make sure that only the key(s) you wanted were added.

2. Verify that you can log in to servera from serverb as the student user by using the review3_key private key without being prompted for the password.

   [student@serverb ~]$ ssh -i .ssh/review3_key student@servera
   ...output omitted...
   [student@servera ~]$

3. Exit from servera.

   [student@servera ~]$ exit
   logout
   Connection to servera closed.
   [student@serverb ~]$

On serverb, configure the sshd service to prevent the root user from logging in.

1. Set the PermitRootLogin parameter to no in the /etc/ssh/sshd_config file. Use the sudo vim /etc/ssh/sshd_config command to edit the configuration file.

2. Reload the sshd service.

   [student@serverb ~]$ sudo systemctl reload sshd.service

On serverb, configure the sshd service to prevent users from using their passwords to log in. Users should still be able to authenticate logins by using SSH keys.

1. Set the PasswordAuthentication parameter to no in the /etc/ssh/sshd_config file. Use the sudo vim /etc/ssh/sshd_config command to edit the configuration file.

2. Reload the sshd service.

   [student@serverb ~]$ sudo systemctl reload sshd.service

Install the zsh package.

[student@serverb ~]$ sudo dnf install zsh
...output omitted...
Is this ok [y/N]: y
...output omitted...
Installed:
  zsh-5.8-9.el9.x86_64
Complete!

1. Return to the workstation system as the student user.

   [student@serverb ~]$ exit
   logout
   Connection to serverb closed.
   [student@workstation ~]$