3 * Random_* Compatibility Library
4 * for using the new PHP 7 random_* API in PHP 5 projects
9 * The MIT License (MIT)
11 * Copyright (c) 2015 Paragon Initiative Enterprises
13 * Permission is hereby granted, free of charge, to any person obtaining a copy
14 * of this software and associated documentation files (the "Software"), to deal
15 * in the Software without restriction, including without limitation the rights
16 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
17 * copies of the Software, and to permit persons to whom the Software is
18 * furnished to do so, subject to the following conditions:
20 * The above copyright notice and this permission notice shall be included in
21 * all copies or substantial portions of the Software.
23 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
24 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
25 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
26 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
27 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
28 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
32 if (!defined('PHP_VERSION_ID')) {
33 // This constant was introduced in PHP 5.2.7
34 $RandomCompatversion = explode('.', PHP_VERSION);
37 $RandomCompatversion[0] * 10000
38 + $RandomCompatversion[1] * 100
39 + $RandomCompatversion[2]
41 $RandomCompatversion = null;
44 if (PHP_VERSION_ID < 70000) {
46 if (!defined('RANDOM_COMPAT_READ_BUFFER')) {
47 define('RANDOM_COMPAT_READ_BUFFER', 8);
50 $RandomCompatDIR = dirname(__FILE__);
52 require_once $RandomCompatDIR.'/byte_safe_strings.php';
53 require_once $RandomCompatDIR.'/cast_to_int.php';
54 require_once $RandomCompatDIR.'/error_polyfill.php';
56 if (!function_exists('random_bytes')) {
58 * PHP 5.2.0 - 5.6.x way to implement random_bytes()
60 * We use conditional statements here to define the function in accordance
61 * to the operating environment. It's a micro-optimization.
63 * In order of preference:
64 * 1. Use libsodium if available.
65 * 2. fread() /dev/urandom if available (never on Windows)
66 * 3. mcrypt_create_iv($bytes, MCRYPT_DEV_URANDOM)
67 * 4. COM('CAPICOM.Utilities.1')->GetRandom()
68 * 5. openssl_random_pseudo_bytes() (absolute last resort)
70 * See ERRATA.md for our reasoning behind this particular order
72 if (extension_loaded('libsodium')) {
73 // See random_bytes_libsodium.php
74 if (PHP_VERSION_ID >= 50300 && function_exists('\\Sodium\\randombytes_buf')) {
75 require_once $RandomCompatDIR.'/random_bytes_libsodium.php';
76 } elseif (method_exists('Sodium', 'randombytes_buf')) {
77 require_once $RandomCompatDIR.'/random_bytes_libsodium_legacy.php';
82 * Reading directly from /dev/urandom:
84 if (DIRECTORY_SEPARATOR === '/') {
85 // DIRECTORY_SEPARATOR === '/' on Unix-like OSes -- this is a fast
86 // way to exclude Windows.
87 $RandomCompatUrandom = true;
88 $RandomCompat_basedir = ini_get('open_basedir');
90 if (!empty($RandomCompat_basedir)) {
91 $RandomCompat_open_basedir = explode(
93 strtolower($RandomCompat_basedir)
95 $RandomCompatUrandom = in_array(
97 $RandomCompat_open_basedir
99 $RandomCompat_open_basedir = null;
103 !function_exists('random_bytes')
107 @is_readable('/dev/urandom')
109 // Error suppression on is_readable() in case of an open_basedir
110 // or safe_mode failure. All we care about is whether or not we
111 // can read it at this point. If the PHP environment is going to
112 // panic over trying to see if the file can be read in the first
113 // place, that is not helpful to us here.
115 // See random_bytes_dev_urandom.php
116 require_once $RandomCompatDIR.'/random_bytes_dev_urandom.php';
118 // Unset variables after use
119 $RandomCompat_basedir = null;
120 $RandomCompatUrandom = null;
127 !function_exists('random_bytes')
129 PHP_VERSION_ID >= 50307
131 extension_loaded('mcrypt')
133 // Prevent this code from hanging indefinitely on non-Windows;
134 // see https://bugs.php.net/bug.php?id=69833
136 DIRECTORY_SEPARATOR !== '/' ||
137 (PHP_VERSION_ID <= 50609 || PHP_VERSION_ID >= 50613)
139 // See random_bytes_mcrypt.php
140 require_once $RandomCompatDIR.'/random_bytes_mcrypt.php';
145 !function_exists('random_bytes')
147 extension_loaded('com_dotnet')
151 $RandomCompat_disabled_classes = preg_split(
153 strtolower(ini_get('disable_classes'))
156 if (!in_array('com', $RandomCompat_disabled_classes)) {
158 $RandomCompatCOMtest = new COM('CAPICOM.Utilities.1');
159 if (method_exists($RandomCompatCOMtest, 'GetRandom')) {
160 // See random_bytes_com_dotnet.php
161 require_once $RandomCompatDIR.'/random_bytes_com_dotnet.php';
163 } catch (com_exception $e) {
164 // Don't try to use it.
167 $RandomCompat_disabled_classes = null;
168 $RandomCompatCOMtest = null;
172 * openssl_random_pseudo_bytes()
176 // Unix-like with PHP >= 5.3.0 or
178 DIRECTORY_SEPARATOR === '/'
180 PHP_VERSION_ID >= 50300
183 // Windows with PHP >= 5.4.1
184 PHP_VERSION_ID >= 50401
187 !function_exists('random_bytes')
189 extension_loaded('openssl')
191 // See random_bytes_openssl.php
192 require_once $RandomCompatDIR.'/random_bytes_openssl.php';
196 * throw new Exception
198 if (!function_exists('random_bytes')) {
200 * We don't have any more options, so let's throw an exception right now
201 * and hope the developer won't let it fail silently.
203 function random_bytes($length)
206 'There is no suitable CSPRNG installed on your system'
212 if (!function_exists('random_int')) {
213 require_once $RandomCompatDIR.'/random_int.php';
216 $RandomCompatDIR = null;