S.H.E.L.L CTF 2021: haxxor | szymanski.ninja

haxxor

Category: Cryptography

chal

50 points

Encrypted string : 0x2-0x19-0x14-0x1d-0x1d-0x2a-0x9-0x61-0x3-0x62-0x15-0xe-0x60-0x5-0xe-0x19-0x4-0x19-0x2c

Solution

I’ve prepared below Python script to unxor the flag.

from pwn import xor

encrypted = bytes([0x2, 0x19, 0x14, 0x1d, 0x1d, 0x2a, 0x9, 0x61, 0x3, 0x62, 0x15, 0xe, 0x60, 0x5, 0xe, 0x19, 0x4, 0x19, 0x2c])

key = xor(encrypted[:6], 'SHELL{')

print(xor(encrypted, key).decode())

Output:

SHELL{X0R3D_1T_HUH}

Flag

SHELL{X0R3D_1T_HUH}