worker / src / PHPSecLib / Crypt / Random.php

Random.php in ManageWP Worker 4.9.25, at src/PHPSecLib/Crypt/Random.php

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1	<?php
2
3	/**
4	* Random Number Generator
5	*
6	* The idea behind this function is that it can be easily replaced with your own crypt_random_string()
7	* function. eg. maybe you have a better source of entropy for creating the initial states or whatever.
8	*
9	* PHP versions 4 and 5
10	*
11	* Here's a short example of how to use this library:
12	* <code>
13	* <?php
14	* include 'Crypt/Random.php';
15	*
16	* echo bin2hex(crypt_random_string(8));
17	* ?>
18	* </code>
19	*
20	* LICENSE: Permission is hereby granted, free of charge, to any person obtaining a copy
21	* of this software and associated documentation files (the "Software"), to deal
22	* in the Software without restriction, including without limitation the rights
23	* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
24	* copies of the Software, and to permit persons to whom the Software is
25	* furnished to do so, subject to the following conditions:
26	*
27	* The above copyright notice and this permission notice shall be included in
28	* all copies or substantial portions of the Software.
29	*
30	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
31	* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
32	* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
33	* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
34	* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
35	* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
36	* THE SOFTWARE.
37	*
38	* @category Crypt
39	* @package Crypt_Random
40	* @author Jim Wigginton <terrafrost@php.net>
41	* @copyright MMVII Jim Wigginton
42	* @license http://www.opensource.org/licenses/mit-license.html MIT License
43	* @link http://phpseclib.sourceforge.net
44	*/
45
46	// laravel is a PHP framework that utilizes phpseclib. laravel workbenches may, independently,
47	// have phpseclib as a requirement as well. if you're developing such a program you may encounter
48	// a "Cannot redeclare crypt_random_string()" error.
49	if (!function_exists('crypt_random_string')) {
50	/**
51	* "Is Windows" test
52	*
53	* @access private
54	*/
55	define('CRYPT_RANDOM_IS_WINDOWS', strtoupper(substr(PHP_OS, 0, 3)) === 'WIN');
56
57	/**
58	* Generate a random string.
59	*
60	* Although microoptimizations are generally discouraged as they impair readability this function is ripe with
61	* microoptimizations because this function has the potential of being called a huge number of times.
62	* eg. for RSA key generation.
63	*
64	* @param Integer $length
65	*
66	* @return String
67	* @access public
68	*/
69	function crypt_random_string($length)
70	{
71	if (CRYPT_RANDOM_IS_WINDOWS) {
72	// method 1. prior to PHP 5.3 this would call rand() on windows hence the function_exists('class_alias') call.
73	// ie. class_alias is a function that was introduced in PHP 5.3
74	if (version_compare(PHP_VERSION, '5.3.6', '!=') && function_exists('mcrypt_create_iv') && function_exists('class_alias')) {
75	return mcrypt_create_iv($length);
76	}
77	// method 2. openssl_random_pseudo_bytes was introduced in PHP 5.3.0 but prior to PHP 5.3.4 there was,
78	// to quote <http://php.net/ChangeLog-5.php#5.3.4>, "possible blocking behavior". as of 5.3.4
79	// openssl_random_pseudo_bytes and mcrypt_create_iv do the exact same thing on Windows. ie. they both
80	// call php_win32_get_random_bytes():
81	//
82	// https://github.com/php/php-src/blob/7014a0eb6d1611151a286c0ff4f2238f92c120d6/ext/openssl/openssl.c#L5008
83	// https://github.com/php/php-src/blob/7014a0eb6d1611151a286c0ff4f2238f92c120d6/ext/mcrypt/mcrypt.c#L1392
84	//
85	// php_win32_get_random_bytes() is defined thusly:
86	//
87	// https://github.com/php/php-src/blob/7014a0eb6d1611151a286c0ff4f2238f92c120d6/win32/winutil.c#L80
88	//
89	// we're calling it, all the same, in the off chance that the mcrypt extension is not available
90	if (function_exists('openssl_random_pseudo_bytes') && version_compare(PHP_VERSION, '5.3.4', '>=')) {
91	return openssl_random_pseudo_bytes($length);
92	}
93	} else {
94	// method 1. the fastest
95	if (function_exists('openssl_random_pseudo_bytes')) {
96	return openssl_random_pseudo_bytes($length);
97	}
98	// method 2
99	static $fp = true;
100	if ($fp === true) {
101	// warning's will be output unles the error suppression operator is used. errors such as
102	// "open_basedir restriction in effect", "Permission denied", "No such file or directory", etc.
103	$fp = @fopen('/dev/urandom', 'rb');
104	}
105	if ($fp !== true && $fp !== false) { // surprisingly faster than !is_bool() or is_resource()
106	return fread($fp, $length);
107	}
108	// method 3. pretty much does the same thing as method 2 per the following url:
109	// https://github.com/php/php-src/blob/7014a0eb6d1611151a286c0ff4f2238f92c120d6/ext/mcrypt/mcrypt.c#L1391
110	// surprisingly slower than method 2. maybe that's because mcrypt_create_iv does a bunch of error checking that we're
111	// not doing. regardless, this'll only be called if this PHP script couldn't open /dev/urandom due to open_basedir
112	// restrictions or some such
113	if (function_exists('mcrypt_create_iv')) {
114	return mcrypt_create_iv($length, MCRYPT_DEV_URANDOM);
115	}
116	}
117	// at this point we have no choice but to use a pure-PHP CSPRNG
118
119	// cascade entropy across multiple PHP instances by fixing the session and collecting all
120	// environmental variables, including the previous session data and the current session
121	// data.
122	//
123	// mt_rand seeds itself by looking at the PID and the time, both of which are (relatively)
124	// easy to guess at. linux uses mouse clicks, keyboard timings, etc, as entropy sources, but
125	// PHP isn't low level to be able to use those as sources and on a web server there's not likely
126	// going to be a ton of keyboard or mouse action. web servers do have one thing that we can use
127	// however, a ton of people visiting the website. obviously you don't want to base your seeding
128	// soley on parameters a potential attacker sends but (1) not everything in $_SERVER is controlled
129	// by the user and (2) this isn't just looking at the data sent by the current user - it's based
130	// on the data sent by all users. one user requests the page and a hash of their info is saved.
131	// another user visits the page and the serialization of their data is utilized along with the
132	// server envirnment stuff and a hash of the previous http request data (which itself utilizes
133	// a hash of the session data before that). certainly an attacker should be assumed to have
134	// full control over his own http requests. he, however, is not going to have control over
135	// everyone's http requests.
136	static $crypto = false, $v;
137	if ($crypto === false) {
138	// save old session data
139	$old_session_id = session_id();
140	$old_use_cookies = ini_get('session.use_cookies');
141	$old_session_cache_limiter = session_cache_limiter();
142	$_OLD_SESSION = isset($_SESSION) ? $_SESSION : false;
143	if ($old_session_id != '') {
144	session_write_close();
145	}
146
147	session_id(1);
148	ini_set('session.use_cookies', 0);
149	session_cache_limiter('');
150	session_start();
151
152	$v = $seed = $_SESSION['seed'] = pack('H*', sha1(
153	serialize($_SERVER).
154	serialize($_POST).
155	serialize($_GET).
156	serialize($_COOKIE).
157	serialize($_SESSION).
158	serialize($_OLD_SESSION)
159	));
160	if (!isset($_SESSION['count'])) {
161	$_SESSION['count'] = 0;
162	}
163	$_SESSION['count']++;
164
165	session_write_close();
166
167	// restore old session data
168	if ($old_session_id != '') {
169	session_id($old_session_id);
170	session_start();
171	ini_set('session.use_cookies', $old_use_cookies);
172	session_cache_limiter($old_session_cache_limiter);
173	} else {
174	if ($_OLD_SESSION !== false) {
175	$_SESSION = $_OLD_SESSION;
176	unset($_OLD_SESSION);
177	} else {
178	unset($_SESSION);
179	}
180	}
181
182	// in SSH2 a shared secret and an exchange hash are generated through the key exchange process.
183	// the IV client to server is the hash of that "nonce" with the letter A and for the encryption key it's the letter C.
184	// if the hash doesn't produce enough a key or an IV that's long enough concat successive hashes of the
185	// original hash and the current hash. we'll be emulating that. for more info see the following URL:
186	//
187	// http://tools.ietf.org/html/rfc4253#section-7.2
188	//
189	// see the is_string($crypto) part for an example of how to expand the keys
190	$key = pack('H*', sha1($seed.'A'));
191	$iv = pack('H*', sha1($seed.'C'));
192
193	// ciphers are used as per the nist.gov link below. also, see this link:
194	//
195	// http://en.wikipedia.org/wiki/Cryptographically_secure_pseudorandom_number_generator#Designs_based_on_cryptographic_primitives
196	switch (true) {
197	case mwp_phpseclib_resolve_include_path('Crypt/AES.php'):
198	if (!class_exists('Crypt_AES')) {
199	require_once dirname(__FILE__).'/AES.php';
200	}
201	$crypto = new Crypt_AES(CRYPT_AES_MODE_CTR);
202	break;
203	case mwp_phpseclib_resolve_include_path('Crypt/Twofish.php'):
204	if (!class_exists('Crypt_Twofish')) {
205	require_once dirname(__FILE__).'/Twofish.php';
206	}
207	$crypto = new Crypt_Twofish(CRYPT_TWOFISH_MODE_CTR);
208	break;
209	case mwp_phpseclib_resolve_include_path('Crypt/Blowfish.php'):
210	if (!class_exists('Crypt_Blowfish')) {
211	require_once dirname(__FILE__).'/Blowfish.php';
212	}
213	$crypto = new Crypt_Blowfish(CRYPT_BLOWFISH_MODE_CTR);
214	break;
215	case mwp_phpseclib_resolve_include_path('Crypt/TripleDES.php'):
216	if (!class_exists('Crypt_TripleDES')) {
217	require_once dirname(__FILE__).'/TripleDES.php';
218	}
219	$crypto = new Crypt_TripleDES(CRYPT_DES_MODE_CTR);
220	break;
221	case mwp_phpseclib_resolve_include_path('Crypt/DES.php'):
222	if (!class_exists('Crypt_DES')) {
223	require_once dirname(__FILE__).'/DES.php';
224	}
225	$crypto = new Crypt_DES(CRYPT_DES_MODE_CTR);
226	break;
227	case mwp_phpseclib_resolve_include_path('Crypt/RC4.php'):
228	if (!class_exists('Crypt_RC4')) {
229	require_once dirname(__FILE__).'/RC4.php';
230	}
231	$crypto = new Crypt_RC4();
232	break;
233	default:
234	user_error('crypt_random_string requires at least one symmetric cipher be loaded');
235
236	return false;
237	}
238
239	$crypto->setKey($key);
240	$crypto->setIV($iv);
241	$crypto->enableContinuousBuffer();
242	}
243
244	//return $crypto->encrypt(str_repeat("\0", $length));
245
246	// the following is based off of ANSI X9.31:
247	//
248	// http://csrc.nist.gov/groups/STM/cavp/documents/rng/931rngext.pdf
249	//
250	// OpenSSL uses that same standard for it's random numbers:
251	//
252	// http://www.opensource.apple.com/source/OpenSSL/OpenSSL-38/openssl/fips-1.0/rand/fips_rand.c
253	// (do a search for "ANS X9.31 A.2.4")
254	$result = '';
255	while (strlen($result) < $length) {
256	$i = $crypto->encrypt(microtime()); // strlen(microtime()) == 21
257	$r = $crypto->encrypt($i ^ $v); // strlen($v) == 20
258	$v = $crypto->encrypt($r ^ $i); // strlen($r) == 20
259	$result .= $r;
260	}
261
262	return substr($result, 0, $length);
263	}
264	}
265
266	if (!function_exists('phpseclib_resolve_include_path')) {
267	/**
268	* Resolve filename against the include path.
269	*
270	* Wrapper around stream_resolve_include_path() (which was introduced in
271	* PHP 5.3.2) with fallback implementation for earlier PHP versions.
272	*
273	* @param string $filename
274	*
275	* @return mixed Filename (string) on success, false otherwise.
276	* @access public
277	*/
278	function phpseclib_resolve_include_path($filename)
279	{
280	if (function_exists('stream_resolve_include_path')) {
281	return stream_resolve_include_path($filename);
282	}
283
284	// handle non-relative paths
285	if (file_exists($filename)) {
286	return realpath($filename);
287	}
288
289	$paths = PATH_SEPARATOR == ':' ?
290	preg_split('#(?<!phar):#', get_include_path()) :
291	explode(PATH_SEPARATOR, get_include_path());
292	foreach ($paths as $prefix) {
293	// path's specified in include_path don't always end in /
294	$ds = substr($prefix, -1) == DIRECTORY_SEPARATOR ? '' : DIRECTORY_SEPARATOR;
295	$file = $prefix.$ds.$filename;
296	if (file_exists($file)) {
297	return realpath($file);
298	}
299	}
300
301	return false;
302	}
303	}
304
305	if (!function_exists('mwp_phpseclib_resolve_include_path')) {
306	/**
307	* We don't rely on include_path or PHAR, so support only one option.
308	*
309	* @param string $filename
310	*
311	* @return mixed Filename (string) on success, false otherwise.
312	* @access public
313	*/
314	function mwp_phpseclib_resolve_include_path($filename)
315	{
316	if (file_exists(dirname(__FILE__).'/../'.$filename)) {
317	return realpath(dirname(__FILE__).'/../'.$filename);
318	}
319
320	return false;
321	}
322	}
323