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Diffstat (limited to 'plugins/OStatus/extlib/Crypt/Random.php')
-rw-r--r-- | plugins/OStatus/extlib/Crypt/Random.php | 125 |
1 files changed, 125 insertions, 0 deletions
diff --git a/plugins/OStatus/extlib/Crypt/Random.php b/plugins/OStatus/extlib/Crypt/Random.php new file mode 100644 index 000000000..bfc24ca62 --- /dev/null +++ b/plugins/OStatus/extlib/Crypt/Random.php @@ -0,0 +1,125 @@ +<?php +/* vim: set expandtab tabstop=4 shiftwidth=4 softtabstop=4: */ + +/** + * Random Number Generator + * + * PHP versions 4 and 5 + * + * Here's a short example of how to use this library: + * <code> + * <?php + * include('Crypt/Random.php'); + * + * echo crypt_random(); + * ?> + * </code> + * + * LICENSE: This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this library; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, + * MA 02111-1307 USA + * + * @category Crypt + * @package Crypt_Random + * @author Jim Wigginton <terrafrost@php.net> + * @copyright MMVII Jim Wigginton + * @license http://www.gnu.org/licenses/lgpl.txt + * @version $Id: Random.php,v 1.6 2010/02/28 05:28:38 terrafrost Exp $ + * @link http://phpseclib.sourceforge.net + */ + +/** + * Generate a random value. + * + * On 32-bit machines, the largest distance that can exist between $min and $max is 2**31. + * If $min and $max are farther apart than that then the last ($max - range) numbers. + * + * Depending on how this is being used, it may be worth while to write a replacement. For example, + * a PHP-based web app that stores its data in an SQL database can collect more entropy than this function + * can. + * + * @param optional Integer $min + * @param optional Integer $max + * @return Integer + * @access public + */ +function crypt_random($min = 0, $max = 0x7FFFFFFF) +{ + if ($min == $max) { + return $min; + } + + // see http://en.wikipedia.org/wiki//dev/random + if (file_exists('/dev/urandom')) { + $fp = fopen('/dev/urandom', 'rb'); + extract(unpack('Nrandom', fread($fp, 4))); + fclose($fp); + + // say $min = 0 and $max = 3. if we didn't do abs() then we could have stuff like this: + // -4 % 3 + 0 = -1, even though -1 < $min + return abs($random) % ($max - $min) + $min; + } + + /* Prior to PHP 4.2.0, mt_srand() had to be called before mt_rand() could be called. + Prior to PHP 5.2.6, mt_rand()'s automatic seeding was subpar, as elaborated here: + + http://www.suspekt.org/2008/08/17/mt_srand-and-not-so-random-numbers/ + + The seeding routine is pretty much ripped from PHP's own internal GENERATE_SEED() macro: + + http://svn.php.net/viewvc/php/php-src/branches/PHP_5_3_2/ext/standard/php_rand.h?view=markup */ + if (version_compare(PHP_VERSION, '5.2.5', '<=')) { + static $seeded; + if (!isset($seeded)) { + $seeded = true; + mt_srand(fmod(time() * getmypid(), 0x7FFFFFFF) ^ fmod(1000000 * lcg_value(), 0x7FFFFFFF)); + } + } + + static $crypto; + + // The CSPRNG's Yarrow and Fortuna periodically reseed. This function can be reseeded by hitting F5 + // in the browser and reloading the page. + + if (!isset($crypto)) { + $key = $iv = ''; + for ($i = 0; $i < 8; $i++) { + $key.= pack('n', mt_rand(0, 0xFFFF)); + $iv .= pack('n', mt_rand(0, 0xFFFF)); + } + switch (true) { + case class_exists('Crypt_AES'): + $crypto = new Crypt_AES(CRYPT_AES_MODE_CTR); + break; + case class_exists('Crypt_TripleDES'): + $crypto = new Crypt_TripleDES(CRYPT_DES_MODE_CTR); + break; + case class_exists('Crypt_DES'): + $crypto = new Crypt_DES(CRYPT_DES_MODE_CTR); + break; + case class_exists('Crypt_RC4'): + $crypto = new Crypt_RC4(); + break; + default: + extract(unpack('Nrandom', pack('H*', sha1(mt_rand(0, 0x7FFFFFFF))))); + return abs($random) % ($max - $min) + $min; + } + $crypto->setKey($key); + $crypto->setIV($iv); + } + + extract(unpack('Nrandom', $crypto->encrypt("\0\0\0\0"))); + return abs($random) % ($max - $min) + $min; +} +?>
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