<?php // $Id: bcpowmod.php,v 1.1 2007/07/02 04:19:55 terrafrost Exp $ /** * Replace bcpowmod() * * @category PHP * @package PHP_Compat * @license LGPL - http://www.gnu.org/licenses/lgpl.html * @copyright 2004-2007 Aidan Lister <aidan@php.net>, Arpad Ray <arpad@php.net> * @link http://php.net/function.bcpowmod * @author Sara Golemon <pollita@php.net> * @version $Revision: 1.1 $ * @since PHP 5.0.0 * @require PHP 4.0.0 (user_error) */ function php_compat_bcpowmod($x, $y, $modulus, $scale = 0) { // Sanity check if (!is_scalar($x)) { user_error('bcpowmod() expects parameter 1 to be string, ' . gettype($x) . ' given', E_USER_WARNING); return false; } if (!is_scalar($y)) { user_error('bcpowmod() expects parameter 2 to be string, ' . gettype($y) . ' given', E_USER_WARNING); return false; } if (!is_scalar($modulus)) { user_error('bcpowmod() expects parameter 3 to be string, ' . gettype($modulus) . ' given', E_USER_WARNING); return false; } if (!is_scalar($scale)) { user_error('bcpowmod() expects parameter 4 to be integer, ' . gettype($scale) . ' given', E_USER_WARNING); return false; } $t = '1'; while (bccomp($y, '0')) { if (bccomp(bcmod($y, '2'), '0')) { $t = bcmod(bcmul($t, $x), $modulus); $y = bcsub($y, '1'); } $x = bcmod(bcmul($x, $x), $modulus); $y = bcdiv($y, '2'); } return $t; } // Define if (!function_exists('bcpowmod')) { function bcpowmod($x, $y, $modulus, $scale = 0) { return php_compat_bcpowmod($x, $y, $modulus, $scale); } } ?>