Hackappatoi CTF 2023

The First Horseman [50 pts]

I don’t think you’re welcome inside this castle… SHISH!

We’re provided a .pyc file. For those who are unaware, this is a Python bytecode file. uncompyle6 is a Python library for decompiling these bytecodes. uncompyle6 -o . thefirsthorseman.pyc decompiles as follows:

# uncompyle6 version 3.9.0
# Python bytecode version base 3.8.0 (3413)
# Decompiled from: Python 3.10.6 (main, Aug 10 2022, 11:40:04) [GCC 11.3.0]
# Embedded file name: ../thefirsthorseman.py
# Compiled at: 2023-11-23 18:14:59
# Size of source mod 2**32: 2794 bytes
from time import sleep
import codecs
print("You've inserted the key you found on the mysterious Laptop and you've been teleported to a place you don't know.")
print('All you can see is an enormous door keeping a castle safe. You approach it and with a bit of fear proceed to open it.')
print('In the middle of the hall you see a funny man, it seems the court jester, but still he scares you.')
print("'SHISH, SHISH' is the only thing he says, and now you realize he is the first horseman, ready to stop you from reaching further in your mission.")
print('The man walks towards you and tries to hit you multiple times! Avoid his punches!\n')

def shish():
    exit("The funny man manages to hit you. You fall on the ground.\nYou don't remember anything. All you know now is a word...\nSHISH\n")


f = [
 "'r3st'", "'4s_a'", "'b3_c'", "'m4tt'", "'l3t_'"]
l = ["'4ll0'", "'30_1'", "'7t3_'", "'jkin'", "'p1ck'"]
a = ["'5_th'", "'3_4n'", "'1t_1'", "'00p5'", "'1n_1'"]
g = ["'p1_7'", "'3_w0'", "'t0g3'", "'00_k'", "'n0th'"]
s = ["'ear5'", "'k!1!'", "'1n6!'", "'33p5'", "'rd_!'"]
counter = 0
indexes = []

def print_flag():
    flag = ''
    flag += f[indexes[0]]
    flag += l[indexes[1]]
    flag += a[indexes[2]]
    flag += g[indexes[3]]
    flag += s[indexes[4]]
    flag = 'upgs{' + flag + '}'
    flag = codecs.encode(flag, 'rot13')
    print(flag)


try:
    for t in range(1, 6):
        print(f"{t}...")
        counter = t
        sleep(1)
    else:
        shish()

except KeyboardInterrupt:
    if counter == 4:
        print('\nYou dodged it\n')
        indexes.append(counter - 1)
    else:
        shish()

try:
    for t in range(1, 6):
        print(f"{t}...")
        counter = t
        sleep(1)
    else:
        shish()

except KeyboardInterrupt:
    if counter == 2:
        print('\nYou dodged it\n')
        indexes.append(counter - 1)
    else:
        shish()

try:
    for t in range(1, 6):
        print(f"{t}...")
        counter = t
        sleep(1)
    else:
        shish()

except KeyboardInterrupt:
    if counter == 1:
        print('\nYou dodged it\n')
        indexes.append(counter - 1)
    else:
        shish()

try:
    for t in range(1, 6):
        print(f"{t}...")
        counter = t
        sleep(1)
    else:
        shish()

except KeyboardInterrupt:
    if counter == 2:
        print('\nYou dodged it\n')
        indexes.append(counter - 1)
    else:
        shish()
else:
    try:
        for t in range(1, 6):
            print(f"{t}...")
            counter = t
            sleep(1)
        else:
            shish()

    except KeyboardInterrupt:
        if counter == 5:
            print('\nYou dodged it\n')
            indexes.append(counter - 1)
        else:
            shish()
    else:
        print('The man is tired, he just hands you a slip of paper, to open the next door.\nThis is what you read')
        print_flag()
        print("The man then says his last words...\n 'https://youtu.be/XH0CSzdHwg0?si=DOwRhOnorrc-WWIx'")

Seems pretty simple to figure out. I quickly realized the following strings were right:

'm4tt'
'30_1'
'5_th'
'3_w0'
'rd_!'

After not getting the right flag for a while, I realized that these strings were actually ROT13’d to get the flag, and were not in the actual flag. Therefore, the flag was:

hctf{z4gg30_15_gu3_j0eq_!}

Nightxade: CTF Writeups

Hackappatoi CTF 2023

The First Horseman [50 pts]