mirror of
https://github.com/danog/tgseclib.git
synced 2024-12-11 16:49:41 +01:00
263 lines
12 KiB
PHP
263 lines
12 KiB
PHP
<?php
|
|
|
|
/**
|
|
* Random Number Generator
|
|
*
|
|
* The idea behind this function is that it can be easily replaced with your own crypt_random_string()
|
|
* function. eg. maybe you have a better source of entropy for creating the initial states or whatever.
|
|
*
|
|
* PHP versions 4 and 5
|
|
*
|
|
* Here's a short example of how to use this library:
|
|
* <code>
|
|
* <?php
|
|
* include 'Crypt/Random.php';
|
|
*
|
|
* echo bin2hex(crypt_random_string(8));
|
|
* ?>
|
|
* </code>
|
|
*
|
|
* LICENSE: 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.
|
|
*
|
|
* @category Crypt
|
|
* @package Crypt_Random
|
|
* @author Jim Wigginton <terrafrost@php.net>
|
|
* @copyright MMVII Jim Wigginton
|
|
* @license http://www.opensource.org/licenses/mit-license.html MIT License
|
|
* @link http://phpseclib.sourceforge.net
|
|
*/
|
|
|
|
// laravel is a PHP framework that utilizes phpseclib. laravel workbenches may, independently,
|
|
// have phpseclib as a requirement as well. if you're developing such a program you may encounter
|
|
// a "Cannot redeclare crypt_random_string()" error.
|
|
if (!function_exists('crypt_random_string')) {
|
|
/**
|
|
* "Is Windows" test
|
|
*
|
|
* @access private
|
|
*/
|
|
define('CRYPT_RANDOM_IS_WINDOWS', strtoupper(substr(PHP_OS, 0, 3)) === 'WIN');
|
|
|
|
/**
|
|
* Generate a random string.
|
|
*
|
|
* Although microoptimizations are generally discouraged as they impair readability this function is ripe with
|
|
* microoptimizations because this function has the potential of being called a huge number of times.
|
|
* eg. for RSA key generation.
|
|
*
|
|
* @param Integer $length
|
|
* @return String
|
|
* @access public
|
|
*/
|
|
function crypt_random_string($length)
|
|
{
|
|
if (CRYPT_RANDOM_IS_WINDOWS) {
|
|
// method 1. prior to PHP 5.3 this would call rand() on windows hence the function_exists('class_alias') call.
|
|
// ie. class_alias is a function that was introduced in PHP 5.3
|
|
if (function_exists('mcrypt_create_iv') && function_exists('class_alias')) {
|
|
return mcrypt_create_iv($length);
|
|
}
|
|
// method 2. openssl_random_pseudo_bytes was introduced in PHP 5.3.0 but prior to PHP 5.3.4 there was,
|
|
// to quote <http://php.net/ChangeLog-5.php#5.3.4>, "possible blocking behavior". as of 5.3.4
|
|
// openssl_random_pseudo_bytes and mcrypt_create_iv do the exact same thing on Windows. ie. they both
|
|
// call php_win32_get_random_bytes():
|
|
//
|
|
// https://github.com/php/php-src/blob/7014a0eb6d1611151a286c0ff4f2238f92c120d6/ext/openssl/openssl.c#L5008
|
|
// https://github.com/php/php-src/blob/7014a0eb6d1611151a286c0ff4f2238f92c120d6/ext/mcrypt/mcrypt.c#L1392
|
|
//
|
|
// php_win32_get_random_bytes() is defined thusly:
|
|
//
|
|
// https://github.com/php/php-src/blob/7014a0eb6d1611151a286c0ff4f2238f92c120d6/win32/winutil.c#L80
|
|
//
|
|
// we're calling it, all the same, in the off chance that the mcrypt extension is not available
|
|
if (function_exists('openssl_random_pseudo_bytes') && version_compare(PHP_VERSION, '5.3.4', '>=')) {
|
|
return openssl_random_pseudo_bytes($length);
|
|
}
|
|
} else {
|
|
// method 1. the fastest
|
|
if (function_exists('openssl_random_pseudo_bytes')) {
|
|
return openssl_random_pseudo_bytes($length);
|
|
}
|
|
// method 2
|
|
static $fp = true;
|
|
if ($fp === true) {
|
|
// warning's will be output unles the error suppression operator is used. errors such as
|
|
// "open_basedir restriction in effect", "Permission denied", "No such file or directory", etc.
|
|
$fp = @fopen('/dev/urandom', 'rb');
|
|
}
|
|
if ($fp !== true && $fp !== false) { // surprisingly faster than !is_bool() or is_resource()
|
|
return fread($fp, $length);
|
|
}
|
|
// method 3. pretty much does the same thing as method 2 per the following url:
|
|
// https://github.com/php/php-src/blob/7014a0eb6d1611151a286c0ff4f2238f92c120d6/ext/mcrypt/mcrypt.c#L1391
|
|
// surprisingly slower than method 2. maybe that's because mcrypt_create_iv does a bunch of error checking that we're
|
|
// not doing. regardless, this'll only be called if this PHP script couldn't open /dev/urandom due to open_basedir
|
|
// restrictions or some such
|
|
if (function_exists('mcrypt_create_iv')) {
|
|
return mcrypt_create_iv($length, MCRYPT_DEV_URANDOM);
|
|
}
|
|
}
|
|
// at this point we have no choice but to use a pure-PHP CSPRNG
|
|
|
|
// cascade entropy across multiple PHP instances by fixing the session and collecting all
|
|
// environmental variables, including the previous session data and the current session
|
|
// data.
|
|
//
|
|
// mt_rand seeds itself by looking at the PID and the time, both of which are (relatively)
|
|
// easy to guess at. linux uses mouse clicks, keyboard timings, etc, as entropy sources, but
|
|
// PHP isn't low level to be able to use those as sources and on a web server there's not likely
|
|
// going to be a ton of keyboard or mouse action. web servers do have one thing that we can use
|
|
// however, a ton of people visiting the website. obviously you don't want to base your seeding
|
|
// soley on parameters a potential attacker sends but (1) not everything in $_SERVER is controlled
|
|
// by the user and (2) this isn't just looking at the data sent by the current user - it's based
|
|
// on the data sent by all users. one user requests the page and a hash of their info is saved.
|
|
// another user visits the page and the serialization of their data is utilized along with the
|
|
// server envirnment stuff and a hash of the previous http request data (which itself utilizes
|
|
// a hash of the session data before that). certainly an attacker should be assumed to have
|
|
// full control over his own http requests. he, however, is not going to have control over
|
|
// everyone's http requests.
|
|
static $crypto = false, $v;
|
|
if ($crypto === false) {
|
|
// save old session data
|
|
$old_session_id = session_id();
|
|
$old_use_cookies = ini_get('session.use_cookies');
|
|
$old_session_cache_limiter = session_cache_limiter();
|
|
$_OLD_SESSION = isset($_SESSION) ? $_SESSION : false;
|
|
if ($old_session_id != '') {
|
|
session_write_close();
|
|
}
|
|
|
|
session_id(1);
|
|
ini_set('session.use_cookies', 0);
|
|
session_cache_limiter('');
|
|
session_start();
|
|
|
|
$v = $seed = $_SESSION['seed'] = pack('H*', sha1(
|
|
serialize($_SERVER) .
|
|
serialize($_POST) .
|
|
serialize($_GET) .
|
|
serialize($_COOKIE) .
|
|
serialize($GLOBALS) .
|
|
serialize($_SESSION) .
|
|
serialize($_OLD_SESSION)
|
|
));
|
|
if (!isset($_SESSION['count'])) {
|
|
$_SESSION['count'] = 0;
|
|
}
|
|
$_SESSION['count']++;
|
|
|
|
session_write_close();
|
|
|
|
// restore old session data
|
|
if ($old_session_id != '') {
|
|
session_id($old_session_id);
|
|
session_start();
|
|
ini_set('session.use_cookies', $old_use_cookies);
|
|
session_cache_limiter($old_session_cache_limiter);
|
|
} else {
|
|
if ($_OLD_SESSION !== false) {
|
|
$_SESSION = $_OLD_SESSION;
|
|
unset($_OLD_SESSION);
|
|
} else {
|
|
unset($_SESSION);
|
|
}
|
|
}
|
|
|
|
// in SSH2 a shared secret and an exchange hash are generated through the key exchange process.
|
|
// the IV client to server is the hash of that "nonce" with the letter A and for the encryption key it's the letter C.
|
|
// if the hash doesn't produce enough a key or an IV that's long enough concat successive hashes of the
|
|
// original hash and the current hash. we'll be emulating that. for more info see the following URL:
|
|
//
|
|
// http://tools.ietf.org/html/rfc4253#section-7.2
|
|
//
|
|
// see the is_string($crypto) part for an example of how to expand the keys
|
|
$key = pack('H*', sha1($seed . 'A'));
|
|
$iv = pack('H*', sha1($seed . 'C'));
|
|
|
|
// ciphers are used as per the nist.gov link below. also, see this link:
|
|
//
|
|
// http://en.wikipedia.org/wiki/Cryptographically_secure_pseudorandom_number_generator#Designs_based_on_cryptographic_primitives
|
|
switch (true) {
|
|
case stream_resolve_include_path('Crypt/AES.php'):
|
|
if (!class_exists('Crypt_AES')) {
|
|
include_once 'AES.php';
|
|
}
|
|
$crypto = new Crypt_AES(CRYPT_AES_MODE_CTR);
|
|
break;
|
|
case stream_resolve_include_path('Crypt/Twofish.php'):
|
|
if (!class_exists('Crypt_Twofish')) {
|
|
include_once 'Twofish.php';
|
|
}
|
|
$crypto = new Crypt_Twofish(CRYPT_TWOFISH_MODE_CTR);
|
|
break;
|
|
case stream_resolve_include_path('Crypt/Blowfish.php'):
|
|
if (!class_exists('Crypt_Blowfish')) {
|
|
include_once 'Blowfish.php';
|
|
}
|
|
$crypto = new Crypt_Blowfish(CRYPT_BLOWFISH_MODE_CTR);
|
|
break;
|
|
case stream_resolve_include_path('Crypt/TripleDES.php'):
|
|
if (!class_exists('Crypt_TripleDES')) {
|
|
include_once 'TripleDES.php';
|
|
}
|
|
$crypto = new Crypt_TripleDES(CRYPT_DES_MODE_CTR);
|
|
break;
|
|
case stream_resolve_include_path('Crypt/DES.php'):
|
|
if (!class_exists('Crypt_DES')) {
|
|
include_once 'DES.php';
|
|
}
|
|
$crypto = new Crypt_DES(CRYPT_DES_MODE_CTR);
|
|
break;
|
|
case stream_resolve_include_path('Crypt/RC4.php'):
|
|
if (!class_exists('Crypt_RC4')) {
|
|
include_once 'RC4.php';
|
|
}
|
|
$crypto = new Crypt_RC4();
|
|
break;
|
|
default:
|
|
user_error('crypt_random_string requires at least one symmetric cipher be loaded');
|
|
return false;
|
|
}
|
|
|
|
$crypto->setKey($key);
|
|
$crypto->setIV($iv);
|
|
$crypto->enableContinuousBuffer();
|
|
}
|
|
|
|
//return $crypto->encrypt(str_repeat("\0", $length));
|
|
|
|
// the following is based off of ANSI X9.31:
|
|
//
|
|
// http://csrc.nist.gov/groups/STM/cavp/documents/rng/931rngext.pdf
|
|
//
|
|
// OpenSSL uses that same standard for it's random numbers:
|
|
//
|
|
// http://www.opensource.apple.com/source/OpenSSL/OpenSSL-38/openssl/fips-1.0/rand/fips_rand.c
|
|
// (do a search for "ANS X9.31 A.2.4")
|
|
$result = '';
|
|
while (strlen($result) < $length) {
|
|
$i = $crypto->encrypt(microtime()); // strlen(microtime()) == 21
|
|
$r = $crypto->encrypt($i ^ $v); // strlen($v) == 20
|
|
$v = $crypto->encrypt($r ^ $i); // strlen($r) == 20
|
|
$result.= $r;
|
|
}
|
|
return substr($result, 0, $length);
|
|
}
|
|
}
|