' 32 Numerics and alphas - we are missing I, O, S and Z not just because
' we only want 32 characters but also because I could be mistaken for
' the number 1, O for 0, S for 5 and Z for 2.
Private Const VALID_CHARS As String = "0123456789ABCDEFGHJKLMNPQRTUVWXY"

Private Const RANDOM_LOWER As Long = 0
Private Const RANDOM_UPPER As Long = 31

'*******************************************************************************
' GenerateKey (FUNCTION)
'
' PARAMETERS:
' (In/Out) - sAppChars - String - Application specific characters to be used
'                                 during the MD5 operation.
'
' RETURN VALUE:
' String - The key
'
' DESCRIPTION:
' Generates a random key by first selecting 9 random characters from our 32
' valid characters, adding our application specific characters, creating an
' MD5 digest, and using the digest to select the other 16 characters for
' our key.
'*******************************************************************************
Public Function GenerateKey(sAppChars As String) As String
    Dim lChar           As Long
    Dim lCount          As Long
    Dim sInitialChars   As String
    Dim oMD5            As CMD5
    Dim sMD5            As String
    Dim sKey            As String
    
    Randomize
    
    ' We first generate 9 random characters that are members of VALID_CHARS
    sInitialChars = ""
    For lCount = 1 To 9
        lChar = Int((RANDOM_UPPER - RANDOM_LOWER + 1) * Rnd + RANDOM_LOWER)
        sInitialChars = sInitialChars & Mid(VALID_CHARS, lChar + 1, 1)
    Next
    
    ' We now get an MD5 of our initial chars plus out application chars
    ' The application chars should be different for each application to
    ' ensure that a key for one of our applications is not valid on another
    ' of our applications. If hackers know we are using this method for
    ' generating our keys we should ensure that the application characters
    ' are very long to help prevent cracking.
    Set oMD5 = New CMD5
    sMD5 = oMD5.MD5(sInitialChars & sAppChars)
    Set oMD5 = Nothing
    
    ' We now take each byte-pair from the MD5, convert it back to a byte
    ' value from the hex code, do a MOD 32, and then select the appropriate
    ' character from our VALID_CHARS
    sKey = sInitialChars
    
    For lCount = 1 To 16
        lChar = CLng("&H" & Mid(sMD5, (lCount * 2) - 1, 2)) Mod 32
        sKey = sKey & Mid(VALID_CHARS, lChar + 1, 1)
    Next
    
    GenerateKey = sKey
End Function

use CGI qw(:standard);
use Digest::MD5 qw(md5 md5_hex md5_base64);

$passphrase = "WRDCT";
$numkeys = 1;

$i = 1;

while ($i <= $numkeys) {
	@digit = qw(0 1 2 3 4 5 6 7 8 9 A B C D E F G H J K L M N P Q R T U V W X Y);

	# Generate 9 random @digits
	srand;
	$randchars = join('', map{ $digit[rand(@digit)] }(1 .. 9) );
	print "$randcharsn";

	# Add the passphrase to the random characters
	$randchars .= $passphrase;
	print "$randcharsn";

	# MD5-encrypt all of it
	$hash = md5_hex($randchars);
	print "$hashn";

	# Take each byte-pair from the MD5, convert it back to a byte
     	# value from the hex code, do a % 32, and then select the appropriate
   	# character from @digits
	$finalkey = $randchars;

	my $lcount;
	for ($lcount; $lcount <= 16; $lcount++) {
		my $lchar = hex(substr($hash, ($lcount * 2) - 1, 2)) % 32;
		$finalkey .= $digits[$lchar + 1];
	}

	$i++;
}