Decrypt the WordPress password. include('classhash.php')

Decrypt the WordPress password

$username = '';
$password = '';

$strSql = "SELECT user_pass FROM wp_users WHERE user_login = '$username'";
$result = mysql_query($strSql);
$row = mysql_fetch_array($result);
$encpass = $row['user_pass'];

if(!is_null($encpass)) {
	include('classhash.php'); 
	$wp_hasher = new PasswordHash(8, TRUE);
	$password_hashed = $encpass;
	$plain_password = $password;
		
	if($wp_hasher->CheckPassword($plain_password, $password_hashed)) {
	   echo "Success";
	}
	else {
	   echo "Failed";
	}
}
else {
	 echo "Not found.";
}

where is classhash.php ? cant find it in main directory.