Monks,

At work I often have the need to do a licence audit.

A few years ago I rewrote this small section of code in perl, based on another script (which I seem to recall was visual basic). This will decode the licence keys from your registry for Windows and Office, for all the versions I have come across.

For Windows, you will need to look in HKLM\Software\Microsoft\Windows Nt\CurrentVersion\DigitalProductID

sub decodekey {
  my @digits = ('B','C','D','F','G','H','J','K','M','P','Q','R','T','V
+','W','X','Y','2','3','4','6','7','8','9');
  return "No key found\n" if ($_[0] eq "");
  my @id = split(/,/,shift);
  my $key="";
  for (my $i=28; $i>=0; $i--) {
    if (($i+1)%6) {
      my $ac=0;
      for (my $j=66; $j>=52; $j--) {
        $ac<<=8;
        $ac+=hex $id[$j];
        $id[$j]=sprintf("%x",($ac/24)&255);
        $ac%=24;
      }
      $key=$digits[$ac].$key;
    } else {
      $key='-'.$key;
    }
  }
  return $key;
}
[download]

This can be used by feeding the hexadecimal found in the registry (separated by single commas) to the function.

I also use the following snippet to pull that key remotely using samba4's reg command. (this isn't pretty, but it gives you an idea of usage)

sub regexec {
  my $computer = shift;
  my $outkey = "";
  my $key = `reg query \\\\\\\\$computer\\\\HKLM\\\\Software\\\\Micros
+oft\\\\Windows\\\ Nt\\\\CurrentVersion /v DigitalProductID 2>&1`;
  foreach (split(/\n/,$key)) {
    if (m/\s+DigitalProductID\s+REG_BINARY\s+([A-F0-9]+)/) {
      $_ = $1;
      s/([A-F0-9][A-F0-9])/$1,/g;
      $outkey = $_;
    }
  }
  return $outkey;
}
[download]

Just yesterday, I realised that Office 2008 for the Mac also uses the same format, only it is base64 encoded in this file: /Applications/Microsoft Office 2008/Office/OfficePID.plist

You can use something like this to extract the key from this file.

use strict;
use MIME::Base64;

my $file = '/Applications/Microsoft Office 2008/Office/OfficePID.plist
+';
open (FILE,'<',$file);
my $flag = 0;
my $section = 0;
my $string;
foreach(<FILE>) {
  $flag = 1 if (m/<key>2000<\/key>/);
  $section++ if ($section == 1);
  $section = 1 if (m/<data>/ && $flag==1);
  if (m/<\/data>/) {
    $flag = 0;
    $section = 0;
  }
  if ($section == 2) {
    $string .= $_;
  }
}
close(FILE);
$string =~ s/\s//g;
my $hex = uc(unpack("H*", decode_base64(shift)));
$hex =~ s/(..)/$1,/g;
chop($hex);
decodekey($hex);
[download]

Yes, this is an odd way to parse XML, but it seems that Mac's put some illegal characters in there, causing XML::Parser to die.

I have been pondering whether to post this or not, but considering there are many programs available to do this job hopefully it is OK.