php/extend/Jd/security/Common/IndexCalculator.php

<?php
namespace ACES\Common;

use ACES\Common\Exception\InsufficientSaltLengException;
use ACES\Common\Exception\ArgumentNullException;

class IndexCalculator
{
    public static function sha256Index($pt, $salt){
        if($pt == NULL){
            throw new ArgumentNullException("Input is null for sha256Index function.");
        } elseif ($salt != NULL && strlen($salt) >= 16){
            $data = $pt.$salt;
            $md = hash("sha256", $data, TRUE);
            return $md;
        } else{
            throw new InsufficientSaltLengException("Salt length is too short.");
        }
        
    }
}