Telehack
long live the command line
In the 1983 masterpiece Wargames, David Lightman (Matthew Broderick) a slacker with a heart of gold, accidentally sets off what could be world war III while looking for a prerelease of the latest video game. While much of the film is laughably naive, there are many great examples of how the early internet worked and the ways that it could be compromised. While ARPANET officially shut down in the early 90’s a proxy ARPENT is still maintained on a website called telehack.com
“Telehack is a nostalgic text-based web and telnet game that simulates the internet and BBSs of the 80s and early 90s. Hack into servers, read old text files, browse the Usenet, and chat with friends using many of the same commands you would have used in the 1980’s - 1990’s. It is important to note that Telehack is just a simulation of what hacking was like back in the early days of computing and that all acts of hacking depicted are entirely fictional. No actual hacking occurs on Telehack, it’s just a game people.”
We will use telehack as a tool for learning about early internet protocols and the ways in which they are similar to and different from the structure of the modern internet. Before we can get started we’ll have to get ourselves a command line from which to run our simulation. Before modern operating systems introduced us to Graphical User Interfaces (GUI) computers were controlled by typing commands into a command line. In reality, this is still how computers are controlled, but the GUI makes it so that we don’t have to remember a bunch of strange commands.
Navigate to https://cloud.google.com/shell and agree to any the terms and conditions and click “LAUNCH CLOUD SHELL”
There will be a bunch of gobbledigook, but don’t worry about that. Just pop out the shell window and we can get going.
You should be greeted with some stuff that looks like this
try typing help. This is going to come in super handy as we keep going.
Next type telnet 64.13.139.230 23 Well what do we have here?
Before we go too far, lets dissect that last command telnet telehack.com 23 The first argument designates the protocol that we are going to use. Remember from the last lesson that we need to have an agreed upon language before we can start communicating. telnet is a set of networking protocols that were instrumental in the early days of the internet. It still exists, but it is fundamentally unsecure and is rarely used. The second argument is the IP (Internet Protocol) address of the server that we are going to communicate with. The last argument is the port number that we want to connect over. There are a lot of different ports on a computer connection. Some are reserved for specific services such as http, ftp, ssh, etc. In our case telenet communicates over port 23.
Now that we’re in, it’s time to get cracking. Open up a copy of the Telehack Adventure Follow along with the instructions and happy hacking.