How To Install fwknop-client on Ubuntu 18.04
Introduction
In this tutorial we learn how to install fwknop-client on Ubuntu 18.04.
What is fwknop-client
fwknop-client is:
The FireWall KNock OPerator implements an authorization scheme called Single Packet Authorization (SPA), based on Netfilter and libpcap.
Its main application is to protect services such as OpenSSH with an additional layer of security in order to make the exploitation of vulnerabilities (both 0-day and unpatched code) much more difficult.
This is the client program responsible for accepting password input from the user, constructing SPA packets that conform to the fwknop packet format, and encrypting packet data.
There are three methods to install fwknop-client on Ubuntu 18.04. We can use apt-get, apt and aptitude. In the following sections we will describe each method. You can choose one of them.
Install fwknop-client Using apt-get
Update apt database with apt-get using the following command.
sudo apt-get update
After updating apt database, We can install fwknop-client using apt-get by running the following command:
sudo apt-get -y install fwknop-client
Install fwknop-client Using apt
Update apt database with apt using the following command.
sudo apt update
After updating apt database, We can install fwknop-client using apt by running the following command:
sudo apt -y install fwknop-client
Install fwknop-client Using aptitude
If you want to follow this method, you might need to install aptitude first since aptitude is usually not installed by default on Ubuntu. Update apt database with aptitude using the following command.
sudo aptitude update
After updating apt database, We can install fwknop-client using aptitude by running the following command:
sudo aptitude -y install fwknop-client
How To Uninstall fwknop-client on Ubuntu 18.04
To uninstall only the fwknop-client package we can use the following command:
sudo apt-get remove fwknop-client
Uninstall fwknop-client And Its Dependencies
To uninstall fwknop-client and its dependencies that are no longer needed by Ubuntu 18.04, we can use the command below:
sudo apt-get -y autoremove fwknop-client
Remove fwknop-client Configurations and Data
To remove fwknop-client configuration and data from Ubuntu 18.04 we can use the following command:
sudo apt-get -y purge fwknop-client
Remove fwknop-client configuration, data, and all of its dependencies
We can use the following command to remove fwknop-client configurations, data and all of its dependencies, we can use the following command:
sudo apt-get -y autoremove --purge fwknop-client
References
Summary
In this tutorial we learn how to install fwknop-client package on Ubuntu 18.04 using different package management tools: apt, apt-get and aptitude.