Initial Commit

database/php/pear/PHP/Compat/Function/bcpowmod.php

@@ -0,0 +1,75 @@
+<?php
+// +----------------------------------------------------------------------+
+// | PHP Version 4                                                        |
+// +----------------------------------------------------------------------+
+// | Copyright (c) 1997-2004 The PHP Group                                |
+// +----------------------------------------------------------------------+
+// | This source file is subject to version 3.0 of the PHP license,       |
+// | that is bundled with this package in the file LICENSE, and is        |
+// | available at through the world-wide-web at                           |
+// | http://www.php.net/license/3_0.txt.                                  |
+// | If you did not receive a copy of the PHP license and are unable to   |
+// | obtain it through the world-wide-web, please send a note to          |
+// | license@php.net so we can mail you a copy immediately.               |
+// +----------------------------------------------------------------------+
+// | Authors: Aidan Lister <aidan@php.net>                                |
+// +----------------------------------------------------------------------+
+//
+// $Id: bcpowmod.php,v 1.2 2005/11/22 20:24:45 aidan Exp $
+
+
+/**
+ * Replace bcpowmod()
+ *
+ * @category    PHP
+ * @package     PHP_Compat
+ * @link        http://php.net/function.bcpowmod
+ * @author      Sara Golemon <pollita@php.net>
+ * @version     $Revision: 1.2 $
+ * @since       PHP 5.0.0
+ * @require     PHP 4.0.0 (user_error)
+ */
+if (!function_exists('bcpowmod')) {
+    function bcpowmod($x, $y, $modulus, $scale)
+    {
+        // Sanity check
+        if (!is_scalar($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;
+    }
+}
+
+?>