Official write-up by Cyber League

Cyber League Season 1, Major 1: Long Duration Test Flight Official Write-up

By Cyber League (Div0-N0H4TS)

N0H4TS
2 min readMay 30, 2022

Challenge Details

Name: Long Duration Test Flight
Category: Cryptography

Challenge Description

Your crew will be subjected to an endurance test to ensure you can survive the 1,400 light year trip via a 88-hour simulated flight. No one can intense such a long simulation without food and water. Yet, a SSH private key is given to you. If only you can decipher the message that is encrypted in DES and input the safe word. Pineapple juice? 🍍

A SSH Private Key and a message were provided to the participants.

-----BEGIN OPENSSH PRIVATE KEY-----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-----END OPENSSH PRIVATE KEY-----

Message:

5ed0b9428aa782f5830fcbaf2731c7d95aeca05cd0ad789e282806d86d02c362abe4ed3d98b6ad39

Process of solving the Challenge

Extract the hash from the private key file, using ssh2john

python ssh2john.py id_rsa > id_rsa.hash

Crack the hash using John the Reaper (Roughly 11 minutes to complete).

john id_rsa.hash --wordlist=rockyou.txt --format=SSH

Decrypt the ciphertext using the passphrase on the message and get the flag.

CYBERLEAGUE{y0u_4r3_my_BAbigiRL}

--

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N0H4TS
N0H4TS

Written by N0H4TS

Start as an Apprentice, and become a Master.

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