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2024-07-15 11:28:08 +02:00

101 lines
3.9 KiB
PHP

<?php
/**
* Akeeba Engine
*
* @package akeebaengine
* @copyright Copyright (c)2006-2022 Nicholas K. Dionysopoulos / Akeeba Ltd
* @license GNU General Public License version 3, or later
*/
namespace Akeeba\Engine\Util;
defined('AKEEBAENGINE') || die();
/**
* Crypto-safe random value generator. Based on the Randval class of the Aura for PHP's Session package.
* The following is the license file accompanying the original file.
*
* ********************************************************************************
* Copyright (c) 2011-2016, Aura for PHP
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* - Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* - Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
* ********************************************************************************
*
* Please note that this is a MODIFIED copy of the Randval class, mainly to allow it to be used on hosts
* which lack both mbcrypt and OpenSSL PHP modules.
*/
class RandomValue
{
/**
*
* Returns a cryptographically secure random value.
*
* @param integer $bytes How many bytes to return
*
* @return string
*/
public function generate($bytes = 32)
{
return random_bytes($bytes);
}
/**
* Generates a random string with the specified length. WARNING: You get to specify the number of
* random characters in the string, not the number of random bytes. The character pool is 64 characters
* (6 bits) long. The entropy of your string is 6 * $characters bits. This means that a random string
* of 32 characters has an entropy of 192 bits whereas a random sequence of 32 bytes returned by generate()
* has an entropy of 8 * 32 = 256 bits.
*
* @param int $characters Number of characters
* @param string $characterSet Characters to pick from
*
* @return string
*/
public function generateString($characters = 32, $characterSet = 'abcdefghijklmnopqrstuvwxyz-ABCDEFGHIJKLMNOPQRSTUVWXYZ_0123456789')
{
$sourceString = str_split('abcdefghijklmnopqrstuvwxyz-ABCDEFGHIJKLMNOPQRSTUVWXYZ_0123456789', 1);
$ret = '';
$bytes = ceil($characters / 4) * 3;
$randBytes = $this->generate($bytes);
for ($i = 0; $i < $bytes; $i += 3)
{
$subBytes = substr($randBytes, $i, 3);
$subBytes = str_split($subBytes, 1);
$subBytes = ord($subBytes[0]) * 65536 + ord($subBytes[1]) * 256 + ord($subBytes[2]);
$subBytes = $subBytes & bindec('00000000111111111111111111111111');
$b = [];
$b[0] = $subBytes >> 18;
$b[1] = ($subBytes >> 12) & bindec('111111');
$b[2] = ($subBytes >> 6) & bindec('111111');
$b[3] = $subBytes & bindec('111111');
$ret .= $sourceString[$b[0]] . $sourceString[$b[1]] . $sourceString[$b[2]] . $sourceString[$b[3]];
}
return substr($ret, 0, $characters);
}
}