Decrypt <pack:Password> from service42 files

decrypt_pass.py

#!/usr/bin/env python3
import sys
from cryptography.hazmat.primitives.ciphers import Cipher, algorithms, modes
from cryptography.hazmat.primitives.kdf.pbkdf2 import PBKDF2HMAC
from cryptography.hazmat.primitives import hashes
from cryptography.hazmat.backends import default_backend
from base64 import b64decode

__title__ = "service42 Password Decryptor"
__version__ = "0.1"
__author__ = "Whiterat"

def decrypt_pass(encrypted_pass):
    kdf_salt = b'\xa2\xba\x12\x99\x37\x41\x0a\x67\xc3'
    kdf_key = b"FRoaHAsSHAsVGhkLEhke"

    kdf = PBKDF2HMAC(
        algorithm=hashes.SHA1(),
        length=32,
        salt=kdf_salt,
        iterations=1000,
        backend=default_backend()
    )
    key = kdf.derive(kdf_key)

    cipher = Cipher(
        algorithms.AES(key),
        modes.ECB(),
        backend=default_backend()
    )

    decryptor = cipher.decryptor()
    decrypted_pass = decryptor.update(b64decode(encrypted_pass))
    decrypted_pass += decryptor.finalize()

    try:
        return decrypted_pass.decode('utf-8').strip()
    except UnicodeDecodeError:
        return decrypted_pass

if __name__ == "__main__":
    if len(sys.argv) != 2:
        print("Usage: decrypt_pass.py <encrypted_pass>")
        sys.exit(1)
    encrypted_pass = sys.argv[1]
    print(decrypt_pass(encrypted_pass))