#!/usr/bin/env python2
'''
OWASP ZSC
https://www.owasp.org/index.php/OWASP_ZSC_Tool_Project
https://github.com/zscproject/OWASP-ZSC
http://api.z3r0d4y.com/
https://groups.google.com/d/forum/owasp-zsc [ owasp-zsc[at]googlegroups[dot]com ]
'''
import random
import binascii
import string
from core.compatible import version
_version = version()
chars = string.digits + string.ascii_letters


def start(shellcode, job):
    for line in shellcode.rsplit('\n'):
        if 'push' in line and '$0x' in line and ',' not in line and len(
                line) > 14:
            data = line.rsplit('push')[1].rsplit('$0x')[1]
            t = True
            while t:
                if _version is 2:
                    ebx_1 = binascii.b2a_hex(''.join(random.choice(chars)
                                                     for i in range(4)))
                if _version is 3:
                    ebx_1 = (binascii.b2a_hex((''.join(random.choice(
                        chars) for i in range(4))).encode('latin-1'))
                             ).decode('latin-1')
                ebx_2 = "%x" % (int(data, 16) - int(ebx_1, 16))
                if str('00') not in str(ebx_1) and str('00') not in str(
                        ebx_2) and '-' in ebx_2 and len(ebx_2.replace(
                            '-', '')) >= 7 and len(
                                ebx_1) > 7 and '-' not in ebx_1:
                    ebx_2 = ebx_2.replace('-', '')
                    if job == 'exec' or job == 'add_admin' or job == 'dir_create' or job == 'download_exec':
                        command = '\npush %%ebx\npush $0x%s\npop %%ebx\npush $0x%s\npop %%ecx\nneg %%ecx\nadd %%ebx,%%ecx\npop %%ebx\npush %%ecx\n' % (
                            str(ebx_1), str(ebx_2))
                    elif job == 'create_file' or job == 'disable_firewall' or job == 'download_tofile':
                        command = '\npush %%eax\npush $0x%s\npop %%eax\npush $0x%s\npop %%ecx\nneg %%ecx\nadd %%eax,%%ecx\npop %%eax\npush %%ecx\n' % (
                            str(ebx_1), str(ebx_2))
                    shellcode = shellcode.replace(line, command)
                    t = False
    return shellcode
