BeepBoop Cryptography

Description

Help! My IOT device has gone sentient!

All I wanted to know was the meaning of 42!

It's also waving its arms up and down, and I...

oh no! It's free!

AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA

Automated Challenge Instructions

Detected failure in challenge upload. Original author terminated. Please see attached file BeepBoop for your flag... human.

Attachment: BeepBoop

Flag

sun{exterminate-exterminate-exterminate}

Solution

solver.py

import codecs

with open("BeepBoop", "r") as f:
    data = f.read()

bin_str = data.replace("beep", "0").replace("boop", "1").replace(" ", "")
n = int(bin_str, base=2)
decoded = n.to_bytes((n.bit_length() + 7) // 8, "big").decode()
flag = codecs.encode(decoded, "rot13")

print(flag)

root@kali:~/ctf/SunshineCTF_2023/crypto/BeepBoop Cryptography# python3 solver.py

sun{exterminate-exterminate-exterminate}