#!/usr/bin/python

# Copyright 2016:  dogbert <dogber1@gmail.com>
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
#
#
# This script generates master passwords which can be used to unlock
# the BIOS passwords of most Asus laptops.
# You have to install python for running this script.

import os

def shuffle1(a1, a2):
        v3 = 2
        for i in range(0, a2):
                v4 = v3
                v5 = a1
                while v5 > 0: 
                        if ( v5 < v4 ):
                                v5, v4 = v4, v5
                        v5 %= v4
                if (v4 != 1):
                        v3 += 1;
                        if ( v3 < a1 ):
                                continue
        return v3

def shuffle2(a1, a2, a3):
        if (a1 >= a3):
                a1 %= a3
        result = a1
        if (a2 != 1):
                for i in range(0, a2-1):
                        result = a1 * result % a3;
        return result

def initTable(table, i1=11, i2=19, i3=6):
        table[0] = chr(i1+ord('0'))
        table[1] = chr(i2+ord('0'))
        table[2] = chr(i3+ord('0'))
        table[3] = "6" 
        table[4] = "7" 
        table[5] = "8" 
        table[6] = "9" 
        
        chksum = 0
        for i in range(0, 7):
                chksum += ord(table[i])
        for i in range(7, 32):
                chksum = 33676 * chksum + 12345
                table[i] = chr(((chksum >> 16) & 0x7FFF) % 43 + ord('0'))

        v3 = i1*i2
        v4 = shuffle1((i1-1)*(i2-1), i3)
        for i in range(0, 32):
                table[i] = chr(shuffle2(ord(table[i])-ord('0'), v4, v3))
        
        return table

def calculatePassword(date, table):
        date = int(date.replace("-", ""), 16)
        chksum = date
        password = ""
        for i in range(8):
                chksum = 33676 * chksum + 12345
                index = (chksum >> 16) & 31
                pwdC = ord(table[index]) % 36
                if pwdC > 9:
                        password += chr(pwdC + ord('7'))
                else:
                        password += chr(pwdC + ord('0'))
        return password

table = initTable(['']*32)
print("Master Password Generator for Asus laptops (system date version)")
print("Copyright (C) 2016 dogbert <dogber1@gmail.com>")
print("")
print("When asked for a password, enter an incorrect password, then press Alt+R. A prompt with the system date will appear, e.g. 2013-12-31")
print("")
print("Please enter the system date: ")
inDate = raw_input().strip().replace('/', '-').replace('.', '-')
password = calculatePassword(inDate, table)
print("")
print("The master password is: " + password)
print("")
print("Please note that the password is encoded for US QWERTY keyboard layouts.")
if (os.name == 'nt'):
        print("Press a key to exit...")
        raw_input()