OverTheWire Bandit Level 15->Level 16 - Walkthrough

OverTheWire Bandit Solutions

Introduction

In this post, I will be giving you a walkthrough to the Bandit wargame Level 15->Level 16. To clear this level, it is required to use openssl command as the player needs to submit the password of the current level using SSL encryption.

Goal

Get the password for the next level by submitting the password of the current level to port 30001 on local host using SSL encryption.

Login Details

Server - bandit.labs.overthewire.org
Port - 2220
Username - bandit15
Password - jN2kgmIXJ6fShzhT2avhotn4Zcka6tnt

Theory

OpenSSL is a library for secure communication over a network as it encrypts the data being transferred. It implements the Secure Socket Layer(SSL) and Transport Layer Security(TLS) network protocols that are used to secure the web traffic.
s_client command implements a generic ssl/tls client which can establish a connection to a remote server. To know more about the commands, please go through their man pages. eg.- man openssl, man openssl-s_client
-connect host:port - This is one the option that specifies the host and optional port to connect to. If not specified then an attempt is made to connect to localhost on port 443.

Solution

SSH into the user bandit15 using the command "ssh bandit15@bandit.labs.overthewire.org -p 2220" and the above password. 

Type the command "openssl s_client -connect localhost:30001" to connect to the localhost server with the OpenSSL client.

Now, at the end enter the password for the current level. In return, we will get the password for the next level.

This completes Level 16 walkthrough as we have got the password.
I would encourage you to learn more about the used commands as well as try to find other ways to complete this level. Please post your questions and suggestions in the comment section.