Sophos Firewall: How to set up public key authentication for admin

Overview

• This article describes the steps to configure public key authentication for admin account.

Generate an RSA key pair

• Download and install both PuTTY and PuTTYGen from www.putty.org.
• Open PuTTYGen and select SSH-2 RSA (or RSA in newer version of PuTTYGen) and click Generate.

• Save the public and private key

• Note: PuTTYGen will generate a warning if your keylife isn’t protected by a password. Password protected is recommended as an additional security meansure, but not required for SSH to work.
• If you’d like to set a password, enter it in the Key Passphrase and repeat it in the Confirm Passphrase fields prior to clicking Save private key.

Add the public key to Sophos Firewall

• Copy the public key from PuTTYGen or from it’s saved location and go to Administrator -> Device Access. Add this public key under Public Key Authentication section.

Add the private key to PuTTY and authenticate to Sophos Firewall

• Start PuTTY and go to Connection -> SSH -> Auth.
• Click Browse to select the .ppk keyfile generated earlier.

• Navigate to Session and enter the Sophos Firewall’s IP address or hostname.
• Make sure Connection type is set to SSH and click Open to connect to Sophos Firewall.

 

• Enter the name admin to authenticate to Sophos firewall.