Hackvent_2019/Day 20/decode.py

49 lines
1.2 KiB
Python

#!/usr/bin/python
import requests
import hashlib
import os
byte_300 = [0xCE, 0x55, 0x95, 0x4E, 0x38, 0x0C5, 0x89, 0x0A5, 0x1B, 0x6F, 0x5E, 0x25, 0x0D2, \
0x1D, 0x2A, 0x2B, 0x5E, 0x7B, 0x39, 0x14, 0x8E, 0x0D0, 0x0F0, 0x0F8, 0x0F8, 0x0A5]
EXPECTED_HASH = "f86d4f9d2c049547bd61f942151ffb55"
INPUT_FILE = "PS4UPDATE.PUP"
BUFFER_LENGTH = len(byte_300)
def downloadFile():
print("Downloading file…")
res = requests.get("https://psarchive.darksoftware.xyz/505Retail.PUP")
if res.status_code != 200:
print("Server returned: %d %s" % (res.status_code, res.reason))
exit(1)
buffer = res.content
hash = hashlib.md5(buffer).hexdigest()
if hash != EXPECTED_HASH:
print("Hash does not match:", hash)
exit(1)
with open(INPUT_FILE, "wb") as f:
f.write(buffer)
if not os.path.isfile(INPUT_FILE):
downloadFile()
with open(INPUT_FILE, "rb") as f:
v29 = byte_300.copy()
v14 = 4919;
while True:
f.seek(v14)
input = bytes(f.read(BUFFER_LENGTH))
for i in range(BUFFER_LENGTH):
v29[i] = (v29[i] ^ input[i])
v14 += 4919
if v14 == 24201480: # 4919 times
break
print("".join(chr(x) for x in v29))