jbdecrypt.py

#!/usr/bin/env python
# -*- coding: utf-8 -*-

import argparse

###############################################################################################
##
##  String obfuscation decoder for Boleto themed java downloader 
##  Sample SHA256: dbc180e8c8506d7f56016c86edc0cca1a30a3e4e4239a42b813c1fdfd85b1dcf
##
##  @seanmw
##
#################################################################################################

def decrypt(string, key):
        modifier = ord(string[0]) - 65
        offset = 1
        string = string[1:]
        decoded = ""
        while string:
                decoded += chr((ord(string[0]) - 65) * 25 + (ord(string[1]) - 65) - modifier - key)
                string = string[2:]
        return decoded

def main():
        parser = argparse.ArgumentParser(prog='boleto_decrypt', usage='%(prog)s [options]', description="String decrypter for Boleto string obfuscation")
        parser.add_argument("cipher_text", help="String to decrypt")
        parser.add_argument('key',  help="Key")

        args = parser.parse_args()
        print decrypt(args.cipher_text, int(args.key))
        return 0

if __name__ == '__main__':
        main()