OpenSSH Server full installation guide

The Offensive Security distribution Kali used by many security testers recently released version 2017.2 of their current release. For quite some time now (Since version 2.0) Kali has used Systemd (System Management Daemon) in place of an init system.  This change bring new revolution of enabling and starting services, even though many people are still using the old commands, which often still work but may also lead to errors.  I will guide you Systemd method for enabling and starting the SSH (Secure Shell) service on Kali Linux Terminal;.

The openssh-server package should already be installed in kali, to verify this you can use the bellow command:

# apt list openssh-server

If it installed you see like...

If it’s not installed, you can use this command to install it:

# apt install openssh-server

Before you start SSH, please secure first.  Since Kali comes with pre-generated SSH keys, to make it more secure, the first thing we will do is generate new ones.

To back up the original keys first as a precaution use:

# mkdir /etc/ssh/default_keys

# mv /etc/ssh/ssh_host_* /etc/ssh/default_keys/

Then to regenerate the keys:

# dpkg-reconfigure openssh-server

The next step is to edit the SSH server configuration file with the settings you need:

# nano /etc/ssh/sshd_config

If you are only planning on using SSH briefly the defaults are probably fine.  If you think you will use it for a length of time I would recommend at minimum enabling public key authentication:

PubkeyAuthentication yes

Then disabling password authentication:

PasswordAuthentication no

If you only need to temporarily start up the SSH service it’s recommended to use ssh.socket:

# systemctl start ssh.socket

When finished:

# systemctl stop ssh.socket

To instead permanently enable the SSH service to start whenever the system is booted use:

# systemctl enable ssh.service

Then to use SSH immediately without having to reboot use:

# systemctl start ssh.service

To check the status of the service you can use:

# systemctl status ssh.service

To stop the SSH service use:

# systemctl stop ssh.service

And to disable the SSH service so it no longer starts at boot:

# systemctl disable ssh.service

 This is a guide to for SSH on kali. Please feel free comment or feedback about this post.