OverTheWire Bandit Level 11->Level 12 - Walkthrough

OverTheWire Bandit Solutions

Introduction

In this post, I will be giving you a walkthrough to the Bandit wargame Level 11->Level 12. We will be using a new command "tr" to clear this level. The password is stored in a file data.txt where all lowercase(a-z) and uppercase(A-Z) letters have been rotated by 13 positions. We will use the tr command to replace the characters and get the password.

Goal

Get the password for Level 12 from the file data.txt where all lowercase and uppercase letters have been rotated by 13 positions.

Login Details

Server - bandit.labs.overthewire.org
Port - 2220
Username - bandit11
Password - 6zPeziLdR2RKNdNYFNb6nVCKzphLXHBM

Theory

The letters have been rotated by 13 positions and the "Helpful Reading Material" article on the wargame page will tell more about the ROT13 cipher algorithm. It is a kind of a substitution cipher, however, it is not secure with all the technology available currently.
tr command is used for translating or deleting characters. It has various options available to work with and use as required. The syntax is as follows-:

• tr [options] Set1 [Set2] - options specifies the various flags that can be used with this command, Set1 is the set of characters that are to be replaced or deleted, Set2 specifies the replacement set of characters

Please go through this article to learn more about the "tr" command.

Solution

SSH into the user bandit11 using the command "ssh bandit11@bandit.labs.overthewire.org -p 2220" and the above password. Type ls to see the file "data.txt" present in the home directory of the user.

Type the command "cat data.txt" to check the ciphered contents of the file.

To get the password, we will decipher it using the command "cat data.txt | tr 'A-za-z' 'N-ZA-Mn-za-m'".

This completes the Level 11 walkthrough. Please post your doubts and suggestions in the comment section.