import struct

import hashlib

import zlib

import os

import sys

key = bytes([0x66, 0x16, 0x7E, 0x74, 0x74, 0x6C, 0x3B, 0xB9,

0xC4, 0x86, 0x8C, 0xAC, 0x9D, 0x30, 0x18, 0x96])

def checksum(data: bytes) -> int:

if len(data) <= 0:

return -1

result = 0

for i in range(0, len(data), 2):

result += (data[i] << 8) + data[i + 1]

return (~result) & 0xFFFF

def decrypt(input_bytes: bytes, key: bytes, checksum_val: int) -> bytes:

input_bytes = bytearray(input_bytes)

key_len = len(key)

ext_key = bytearray((checksum_val * k) & 0xFF for k in key)

for i in range(len(input_bytes)):

cur_key = ext_key[i % key_len]

val = (input_bytes[i] - cur_key) & 0xFF

shift = (((cur_key * 0x925) >> 11) + 1) & 7

input_bytes[i] = ((val << shift) | (val >> (8 - shift))) & 0xFF

return bytes(input_bytes)

def read_be16(data: bytes) -> int:

return struct.unpack('>H', data)[0]

def read_be32(data: bytes) -> int:

return struct.unpack('>I', data)[0]

def process_file(path: str, output_dir: str):

with open(path, 'rb') as f:

while True:

start = f.tell()

hash_val = f.read(2)

if not hash_val:

print("Finished processing file.")

break

hash_val = read_be16(hash_val)

# 校验 head

offset = f.tell()

if hash_val != checksum(f.read(62)):

print("Checksum failure")

return

f.seek(offset)

# 读取文件名

file_name_lenght = f.read(2)

file_name_lenght = read_be16(file_name_lenght)

# 读取数据长度

file_data_length = f.read(4)

file_data_length = read_be32(file_data_length)

# 读取 MD5

expected_md5 = f.read(16)

# 跳过校验头

f.seek(start + 64)

# 解密文件名

enc_name = f.read(file_name_lenght)

file_name = decrypt(enc_name, key, hash_val).decode('utf-8', errors='ignore')

# 解密数据

enc_data = f.read(file_data_length)

data = decrypt(enc_data, key, hash_val)

md5 = hashlib.md5(data).digest()

if md5 != expected_md5:

print(f"MD5 mismatch for {file_name}")

return

# 获取解密后数据长度

data_size = data[:4]

data_size = read_be32(data_size)

# zlib 解压

data = data[4:]

decompressed = zlib.decompress(data)

if len(decompressed) != data_size:

print(f"Decompressed size mismatch for {file_name}, expected {data_size}, got {len(decompressed)}")

return

with open(f'{output_dir}/{file_name}', 'wb') as ff:

ff.write(decompressed)

def main():

if len(sys.argv) < 3:

print("Usage: python ik_http_lua.py <input_file> <output_directory>")

exit(1)

input_file = sys.argv[1]

output_directory = sys.argv[2]

if not os.path.exists(output_directory):

os.makedirs(output_directory)

process_file(input_file, output_directory)

if __name__ == "__main__":

main()