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@@ -1,150 +0,0 @@
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-<?php
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-
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-/*
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- * Author:
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- * George Argyros <argyros.george@gmail.com>
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- *
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- * Copyright (c) 2012, George Argyros
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- * All rights reserved.
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- *
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- * Redistribution and use in source and binary forms, with or without
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- * modification, are permitted provided that the following conditions are met:
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- * * Redistributions of source code must retain the above copyright
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- * notice, this list of conditions and the following disclaimer.
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- * * Redistributions in binary form must reproduce the above copyright
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- * notice, this list of conditions and the following disclaimer in the
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- * documentation and/or other materials provided with the distribution.
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- * * Neither the name of the <organization> nor the
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- * names of its contributors may be used to endorse or promote products
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- * derived from this software without specific prior written permission.
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- *
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- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
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- * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
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- * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
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- * DISCLAIMED. IN NO EVENT SHALL GEORGE ARGYROS BE LIABLE FOR ANY
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- * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
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- * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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- * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
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- * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
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- * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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- *
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- *
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- *
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- * The function is providing, at least at the systems tested :),
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- * $len bytes of entropy under any PHP installation or operating system.
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- * The execution time should be at most 10-20 ms in any system.
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- */
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-function secure_random_bytes($len = 10)
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-{
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-
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- /*
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- * Our primary choice for a cryptographic strong randomness function is
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- * openssl_random_pseudo_bytes.
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- */
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- $SSLstr = '4'; // http://xkcd.com/221/
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- if (function_exists('openssl_random_pseudo_bytes') &&
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- (version_compare(PHP_VERSION, '5.3.4') >= 0 ||
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- substr(PHP_OS, 0, 3) !== 'WIN'))
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- {
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- $SSLstr = openssl_random_pseudo_bytes($len, $strong);
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- if ($strong) {
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- return $SSLstr;
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- }
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- }
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-
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- /*
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- * If mcrypt extension is available then we use it to gather entropy from
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- * the operating system's PRNG. This is better than reading /dev/urandom
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- * directly since it avoids reading larger blocks of data than needed.
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- * Older versions of mcrypt_create_iv may be broken or take too much time
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- * to finish so we only use this function with PHP 5.3.7 and above.
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- * @see https://bugs.php.net/bug.php?id=55169
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- */
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- if (function_exists('mcrypt_create_iv') &&
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- (version_compare(PHP_VERSION, '5.3.7') >= 0 ||
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- substr(PHP_OS, 0, 3) !== 'WIN')) {
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- $str = mcrypt_create_iv($len, MCRYPT_DEV_URANDOM);
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- if ($str !== false) {
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- return $str;
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- }
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- }
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-
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-
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- /*
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- * No build-in crypto randomness function found. We collect any entropy
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- * available in the PHP core PRNGs along with some filesystem info and memory
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- * stats. To make this data cryptographically strong we add data either from
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- * /dev/urandom or if its unavailable, we gather entropy by measuring the
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- * time needed to compute a number of SHA-1 hashes.
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- */
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- $str = '';
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- $bits_per_round = 2; // bits of entropy collected in each clock drift round
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- $msec_per_round = 400; // expected running time of each round in microseconds
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- $hash_len = 20; // SHA-1 Hash length
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- $total = $len; // total bytes of entropy to collect
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-
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- $handle = @fopen('/dev/urandom', 'rb');
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- if ($handle && function_exists('stream_set_read_buffer')) {
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- @stream_set_read_buffer($handle, 0);
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- }
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-
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- do
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- {
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- $bytes = ($total > $hash_len)? $hash_len : $total;
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- $total -= $bytes;
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-
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- //collect any entropy available from the PHP system and filesystem
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- $entropy = rand() . uniqid(mt_rand(), true) . $SSLstr;
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- $entropy .= implode('', @fstat(@fopen( __FILE__, 'r')));
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- $entropy .= memory_get_usage() . getmypid();
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- $entropy .= serialize($_ENV) . serialize($_SERVER);
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- if (function_exists('posix_times')) {
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- $entropy .= serialize(posix_times());
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- }
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- if (function_exists('zend_thread_id')) {
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- $entropy .= zend_thread_id();
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- }
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- if ($handle) {
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- $entropy .= @fread($handle, $bytes);
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- } else {
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- // Measure the time that the operations will take on average
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- for ($i = 0; $i < 3; $i++)
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- {
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- $c1 = microtime(true);
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- $var = sha1(mt_rand());
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- for ($j = 0; $j < 50; $j++) {
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- $var = sha1($var);
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- }
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- $c2 = microtime(true);
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- $entropy .= $c1 . $c2;
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- }
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-
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- // Based on the above measurement determine the total rounds
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- // in order to bound the total running time.
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- $rounds = (int) ($msec_per_round * 50 / (int) (($c2 - $c1) * 1000000));
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-
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- // Take the additional measurements. On average we can expect
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- // at least $bits_per_round bits of entropy from each measurement.
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- $iter = $bytes * (int) (ceil(8 / $bits_per_round));
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- for ($i = 0; $i < $iter; $i++)
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- {
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- $c1 = microtime(true);
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- $var = sha1(mt_rand());
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- for ($j = 0; $j < $rounds; $j++) {
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- $var = sha1($var);
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- }
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- $c2 = microtime(true);
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- $entropy .= $c1 . $c2;
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- }
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-
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- }
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- // We assume sha1 is a deterministic extractor for the $entropy variable.
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- $str .= sha1($entropy, true);
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- } while ($len > strlen($str));
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-
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- if ($handle) {
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- @fclose($handle);
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- }
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- return substr($str, 0, $len);
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-}
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