<?php
/**
* Random_* Compatibility Library
* for using the new PHP 7 random_* API in PHP 5 projects
*
* @version 2.0.4
* @released 2016-11-07
*
* The MIT License (MIT)
*
* Copyright (c) 2015 - 2016 Paragon Initiative Enterprises
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/
if (!defined('PHP_VERSION_ID')) {
// This constant was introduced in PHP 5.2.7
$RandomCompatversion = array_map('intval', explode('.', PHP_VERSION));
define(
'PHP_VERSION_ID',
$RandomCompatversion[0] * 10000
+ $RandomCompatversion[1] * 100
+ $RandomCompatversion[2]
);
$RandomCompatversion = null;
}
/**
* PHP 7.0.0 and newer have these functions natively.
*/
if (PHP_VERSION_ID < 70000) {
if (!defined('RANDOM_COMPAT_READ_BUFFER')) {
define('RANDOM_COMPAT_READ_BUFFER', 8);
}
$RandomCompatDIR = dirname(__FILE__);
require_once $RandomCompatDIR.'/byte_safe_strings.php';
require_once $RandomCompatDIR.'/cast_to_int.php';
require_once $RandomCompatDIR.'/error_polyfill.php';
if (!is_callable('random_bytes')) {
/**
* PHP 5.2.0 - 5.6.x way to implement random_bytes()
*
* We use conditional statements here to define the function in accordance
* to the operating environment. It's a micro-optimization.
*
* In order of preference:
* 1. Use libsodium if available.
* 2. fread() /dev/urandom if available (never on Windows)
* 3. mcrypt_create_iv($bytes, MCRYPT_DEV_URANDOM)
* 4. COM('CAPICOM.Utilities.1')->GetRandom()
* 5. openssl_random_pseudo_bytes() (absolute last resort)
*
* See RATIONALE.md for our reasoning behind this particular order
*/
if (extension_loaded('libsodium')) {
// See random_bytes_libsodium.php
if (PHP_VERSION_ID >= 50300 && is_callable('\\Sodium\\randombytes_buf')) {
require_once $RandomCompatDIR.'/random_bytes_libsodium.php';
} elseif (method_exists('Sodium', 'randombytes_buf')) {
require_once $RandomCompatDIR.'/random_bytes_libsodium_legacy.php';
}
}
/**
* Reading directly from /dev/urandom:
*/
if (DIRECTORY_SEPARATOR === '/') {
// DIRECTORY_SEPARATOR === '/' on Unix-like OSes -- this is a fast
// way to exclude Windows.
$RandomCompatUrandom = true;
$RandomCompat_basedir = ini_get('open_basedir');
if (!empty($RandomCompat_basedir)) {
$RandomCompat_open_basedir = explode(
PATH_SEPARATOR,
strtolower($RandomCompat_basedir)
);
$RandomCompatUrandom = (array() !== array_intersect(
array('/dev', '/dev/', '/dev/urandom'),
$RandomCompat_open_basedir
));
$RandomCompat_open_basedir = null;
}
if (
!is_callable('random_bytes')
&&
$RandomCompatUrandom
&&
@is_readable('/dev/urandom')
) {
// Error suppression on is_readable() in case of an open_basedir
// or safe_mode failure. All we care about is whether or not we
// can read it at this point. If the PHP environment is going to
// panic over trying to see if the file can be read in the first
// place, that is not helpful to us here.
// See random_bytes_dev_urandom.php
require_once $RandomCompatDIR.'/random_bytes_dev_urandom.php';
}
// Unset variables after use
$RandomCompat_basedir = null;
} else {
$RandomCompatUrandom = false;
}
/**
* mcrypt_create_iv()
*
* We only want to use mcypt_create_iv() if:
*
* - random_bytes() hasn't already been defined
* - PHP >= 5.3.7
* - the mcrypt extensions is loaded
* - One of these two conditions is true:
* - We're on Windows (DIRECTORY_SEPARATOR !== '/')
* - We're not on Windows and /dev/urandom is readabale
* (i.e. we're not in a chroot jail)
* - Special case:
* - If we're not on Windows, but the PHP version is between
* 5.6.10 and 5.6.12, we don't want to use mcrypt. It will
* hang indefinitely. This is bad.
*/
if (
!is_callable('random_bytes')
&&
PHP_VERSION_ID >= 50307
&&
extension_loaded('mcrypt')
) {
// Prevent this code from hanging indefinitely on non-Windows;
// see https://bugs.php.net/bug.php?id=69833
if (
DIRECTORY_SEPARATOR !== '/' ||
(PHP_VERSION_ID <= 50609 || PHP_VERSION_ID >= 50613)
) {
// See random_bytes_mcrypt.php
require_once $RandomCompatDIR.'/random_bytes_mcrypt.php';
}
}
$RandomCompatUrandom = null;
/**
* This is a Windows-specific fallback, for when the mcrypt extension
* isn't loaded.
*/
if (
!is_callable('random_bytes')
&&
extension_loaded('com_dotnet')
&&
class_exists('COM')
) {
$RandomCompat_disabled_classes = preg_split(
'#\s*,\s*#',
strtolower(ini_get('disable_classes'))
);
if (!in_array('com', $RandomCompat_disabled_classes)) {
try {
$RandomCompatCOMtest = new COM('CAPICOM.Utilities.1');
if (method_exists($RandomCompatCOMtest, 'GetRandom')) {
// See random_bytes_com_dotnet.php
require_once $RandomCompatDIR.'/random_bytes_com_dotnet.php';
}
} catch (com_exception $e) {
// Don't try to use it.
}
}
$RandomCompat_disabled_classes = null;
$RandomCompatCOMtest = null;
}
/**
* throw new Exception
*/
if (!is_callable('random_bytes')) {
/**
* We don't have any more options, so let's throw an exception right now
* and hope the developer won't let it fail silently.
*/
function random_bytes($length)
{
throw new Exception(
'There is no suitable CSPRNG installed on your system'
);
}
}
}
if (!is_callable('random_int')) {
require_once $RandomCompatDIR.'/random_int.php';
}
$RandomCompatDIR = null;
}