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File: lib/Multiotp/contrib/Random.php

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File: lib/Multiotp/contrib/Random.php
Role: Example script
Content type: text/plain
Description: Example script
Class: PHP User Credentials
Implement password authentication policies
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Date: 5 years ago
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<?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 2007 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 int $length * @return string * @access public */ function crypt_random_string($length) { if (CRYPT_RANDOM_IS_WINDOWS) { // method 1. prior to PHP 5.3, mcrypt_create_iv() would call rand() on windows if (extension_loaded('mcrypt') && version_compare(PHP_VERSION, '5.3.0', '>=')) { return mcrypt_create_iv($length); } // method 2. openssl_random_pseudo_bytes was introduced in PHP 5.3.0 but prior to PHP 5.3.4 there was, // to quote <http://php.net/ChangeLog-5.php#5.3.4>, "possible blocking behavior". as of 5.3.4 // openssl_random_pseudo_bytes and mcrypt_create_iv do the exact same thing on Windows. ie. they both // call php_win32_get_random_bytes(): // // https://github.com/php/php-src/blob/7014a0eb6d1611151a286c0ff4f2238f92c120d6/ext/openssl/openssl.c#L5008 // https://github.com/php/php-src/blob/7014a0eb6d1611151a286c0ff4f2238f92c120d6/ext/mcrypt/mcrypt.c#L1392 // // php_win32_get_random_bytes() is defined thusly: // // https://github.com/php/php-src/blob/7014a0eb6d1611151a286c0ff4f2238f92c120d6/win32/winutil.c#L80 // // we're calling it, all the same, in the off chance that the mcrypt extension is not available if (extension_loaded('openssl') && version_compare(PHP_VERSION, '5.3.4', '>=')) { return openssl_random_pseudo_bytes($length); } } else { // method 1. the fastest if (extension_loaded('openssl') && version_compare(PHP_VERSION, '5.3.0', '>=')) { 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, $length); } // method 3. pretty much does the same thing as method 2 per the following url: // https://github.com/php/php-src/blob/7014a0eb6d1611151a286c0ff4f2238f92c120d6/ext/mcrypt/mcrypt.c#L1391 // surprisingly slower than method 2. maybe that's because mcrypt_create_iv does a bunch of error checking that we're // not doing. regardless, this'll only be called if this PHP script couldn't open /dev/urandom due to open_basedir // restrictions or some such if (extension_loaded('mcrypt')) { return mcrypt_create_iv($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 = $_SESSION['seed'] = pack('H*', sha1( (isset($_SERVER) ? phpseclib_safe_serialize($_SERVER) : '') . (isset($_POST) ? phpseclib_safe_serialize($_POST) : '') . (isset($_GET) ? phpseclib_safe_serialize($_GET) : '') . (isset($_COOKIE) ? phpseclib_safe_serialize($_COOKIE) : '') . phpseclib_safe_serialize($GLOBALS) . phpseclib_safe_serialize($_SESSION) . phpseclib_safe_serialize($_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 phpseclib_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 phpseclib_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 phpseclib_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 phpseclib_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 phpseclib_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 phpseclib_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); } } if (!function_exists('phpseclib_safe_serialize')) { /** * Safely serialize variables * * If a class has a private __sleep() method it'll give a fatal error on PHP 5.2 and earlier. * PHP 5.3 will emit a warning. * * @param mixed $arr * @access public */ function phpseclib_safe_serialize(&$arr) { if (is_object($arr)) { return ''; } if (!is_array($arr)) { return serialize($arr); } // prevent circular array recursion if (isset($arr['__phpseclib_marker'])) { return ''; } $safearr = array(); $arr['__phpseclib_marker'] = true; foreach (array_keys($arr) as $key) { // do not recurse on the '__phpseclib_marker' key itself, for smaller memory usage if ($key !== '__phpseclib_marker') { $safearr[$key] = phpseclib_safe_serialize($arr[$key]); } } unset($arr['__phpseclib_marker']); return serialize($safearr); } } if (!function_exists('phpseclib_resolve_include_path')) { /** * Resolve filename against the include path. * * Wrapper around stream_resolve_include_path() (which was introduced in * PHP 5.3.2) with fallback implementation for earlier PHP versions. * * @param string $filename * @return string|false * @access public */ function phpseclib_resolve_include_path($filename) { if (function_exists('stream_resolve_include_path')) { return stream_resolve_include_path($filename); } // handle non-relative paths if (file_exists($filename)) { return realpath($filename); } $paths = PATH_SEPARATOR == ':' ? preg_split('#(?<!phar):#', get_include_path()) : explode(PATH_SEPARATOR, get_include_path()); foreach ($paths as $prefix) { // path's specified in include_path don't always end in / $ds = substr($prefix, -1) == DIRECTORY_SEPARATOR ? '' : DIRECTORY_SEPARATOR; $file = $prefix . $ds . $filename; if (file_exists($file)) { return realpath($file); } } return false; } }