🕺The Last Dance

https://app.hackthebox.com/challenges/The%2520Last%2520Dance

from binascii import unhexlify

# Hex strings from the 'out.txt' file
iv = "c4a66edfe80227b4fa24d431"
ciphertext_message = "7aa34395a258f5893e3db1822139b8c1f04cfab9d757b9b9cca57e1df33d093f07c7f06e06bb6293676f9060a838ea138b6bc9f20b08afeb73120506e2ce7b9b9dcd9e4a421584cfaba2481132dfbdf4216e98e3facec9ba199ca3a97641e9ca9782868d0222a1d7c0d3119b867edaf2e72e2a6f7d344df39a14edc39cb6f960944ddac2aaef324827c36cba67dcb76b22119b43881a3f1262752990"
ciphertext_flag = "7d8273ceb459e4d4386df4e32e1aecc1aa7aaafda50cb982f6c62623cf6b29693d86b15457aa76ac7e2eef6cf814ae3a8d39c7"

# Convert hex to bytes
ciphertext_message_bytes = unhexlify(ciphertext_message)
ciphertext_flag_bytes = unhexlify(ciphertext_flag)

# Known message in bytes
known_message = b"Our counter agencies have intercepted your messages and a lot of your agent's identities have been exposed. In a matter of days all of them will be captured"

# XOR the two ciphertexts together
xor_result = bytes([b1 ^ b2 for b1, b2 in zip(ciphertext_message_bytes, ciphertext_flag_bytes)])

# XOR the result with the known plaintext message to get the flag
recovered_flag = bytes([b1 ^ b2 for b1, b2 in zip(xor_result, known_message)])

print("Recovered FLAG:", recovered_flag.decode())