Duke Nukem 1+2 Remastered .DUKE archive extractor script

evcduke.py

#
# Extracts files from Duke Nukem 1+2 Remastered .DUKE archives
#

import sys
import zlib
import struct
from pathlib import Path
from Crypto.Cipher import AES

def unpack_archive(archive, output_dir):
    magic, version, entry_count, _ = struct.unpack("<4s3i", archive.read(0x10))

    if magic != b'DUKE':
        print("invalid data archive")
        return

    names = {}
    entries = []

    for _ in range(entry_count):
        entry = struct.unpack("<6i8s", archive.read(0x20))
        entries.append(entry)

    for entry in entries:
        _, _, _, offset, length, _, _ = entry

        if length > 0x64:
            print("invalid file name length")
            return

        archive.seek(offset)
        names[entry] = archive.read(length).decode('utf8')

    for entry in entries:
        offset, length, uncompressed_length, _, _, _, nonce = entry
        output_path = Path(output_dir) / names[entry]
        output_path.parent.mkdir(parents=True, exist_ok=True)

        archive.seek(offset)
        key = bytes.fromhex("5755FB6CB9A571BC4F5562EE9299E808241594D1DFA675BEE9DBB51AC087ECCD")
        cipher = AES.new(key, AES.MODE_CTR, nonce=nonce)
        data = cipher.decrypt(archive.read(length))

        if length != uncompressed_length:
            data = zlib.decompress(data, bufsize=uncompressed_length)

        with open(output_path, "wb") as output_file:
            output_file.write(data)

        print(names[entry])

def main():
    if len(sys.argv) != 3:
        print(f"{sys.argv[0]} <archive path> <output dir>")
        return

    with open(sys.argv[1], "rb") as archive:
        unpack_archive(archive, sys.argv[2])

if __name__ == "__main__":
    main()