How To Install fwknop-server on Ubuntu 18.04
Introduction
In this tutorial we learn how to install fwknop-server on Ubuntu 18.04.
What is fwknop-server
fwknop-server 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.
The authorization server passively listens for authorization packets via libpcap, thus preventing any connections from being processed on the traditional port. Access to a protected service is only granted after a valid encrypted and non-replayed packet is detected.
There are three methods to install fwknop-server 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-server 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-server using apt-get by running the following command:
sudo apt-get -y install fwknop-server
Install fwknop-server Using apt
Update apt database with apt using the following command.
sudo apt update
After updating apt database, We can install fwknop-server using apt by running the following command:
sudo apt -y install fwknop-server
Install fwknop-server 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-server using aptitude by running the following command:
sudo aptitude -y install fwknop-server
How To Uninstall fwknop-server on Ubuntu 18.04
To uninstall only the fwknop-server package we can use the following command:
sudo apt-get remove fwknop-server
Uninstall fwknop-server And Its Dependencies
To uninstall fwknop-server and its dependencies that are no longer needed by Ubuntu 18.04, we can use the command below:
sudo apt-get -y autoremove fwknop-server
Remove fwknop-server Configurations and Data
To remove fwknop-server configuration and data from Ubuntu 18.04 we can use the following command:
sudo apt-get -y purge fwknop-server
Remove fwknop-server configuration, data, and all of its dependencies
We can use the following command to remove fwknop-server configurations, data and all of its dependencies, we can use the following command:
sudo apt-get -y autoremove --purge fwknop-server
References
Summary
In this tutorial we learn how to install fwknop-server package on Ubuntu 18.04 using different package management tools: apt, apt-get and aptitude.
