zip - Python unzip AES-128 encrypted file

Question

Is there a way to decompress an AES-128 encrypte file directly with python, since ZipFile throws a Bad Password error. If i use 7zip it works, so the password is correct, but then again 7zip needs to be installed as a dependency.

What i tried:

from ZipFile import ZipFile
zip = ZipFile('test.zip')
zip.extractall(pwd='password')

This throws the Bad Password exception.

Checking the file with 7zip

7z l -slt test.zip

This returns:

Encrypted = +
Method = pkAES-128 Deflate

Answer 1

The zipfile module from the Python standard library supports only CRC32 encrypted zip files (see here: http://hg.python.org/cpython/file/71adf21421d9/Lib/zipfile.py#l420 ). So, there is no way around some 3rd party dependency.

The easiest way would be to just install 7zip and call the commandline utility 7z using the subprocess module from the standard lib:

import subprocess
subprocess.call(["7z", "x", "-ppassword", "test.zip"])

Another option would be the python module "PyLzma" which can also handle AES encrypted 7zip archives: https://github.com/fancycode/pylzma . It doesn't directly support decrypting classic zip files but you could use its routines to write your own decompressor function.