How to use Python to decrypt files encrypted using Vim's cryptmethod=blowfish2?

I would like to use Python to decrypt files encrypted using Vim encrypted with the cryptmethod=blowfish2 method. I have not seen the encryption method documented anywhere and would appreciate help in figuring out how to do this.

Is this a standard ability with Python, or has a library been implemented, or other?

Solution

Check out this module: https://github.com/nlitsme/vimdecrypt. You can use it to decrypt your files, or study the code to learn how to implement it yourself. Example usage:

from collections import namedtuple
from vimdecrypt import decryptfile

args = namedtuple('Args', ('verbose', 'test'))(False, False)
password = 'password'
with open('somefile', 'rb') as somefile:
    decrypted = decryptfile(somefile.read(), password, args)