User name:
Password:
Oracle hash: :

I'm pretty sure I wrote this around August 3rd 2010 and did nothing with it but here you go:
<?php
function oracle($un, $pw)
{
	$pt  = strtoupper($un . $pw);
	$pt .= str_repeat("\0", 3 - ((strlen($pt) - 1) & 3));
	$end = strlen($pt);
 	$pt .= $pt;
	for ($a = 0; $a < $end; $a++)
	{
		$pt[2 * $a] = "\0";
		$pt[2 * $a + 1] = $pt[$a + $end];
	}
	$ct = mcrypt_encrypt(MCRYPT_DES, hex2bin('0123456789ABCDEF'), $pt, 'cbc', "\0\0\0\0\0\0\0\0");
	$ct = mcrypt_encrypt(MCRYPT_DES, substr($ct, -8), $pt, 'cbc', "\0\0\0\0\0\0\0\0");
	return bin2hex(substr($ct, -8));
}
?>