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Diffstat (limited to 'libs/phpseclib-1.0.6/Crypt/Random.php')
-rw-r--r-- | libs/phpseclib-1.0.6/Crypt/Random.php | 334 |
1 files changed, 334 insertions, 0 deletions
diff --git a/libs/phpseclib-1.0.6/Crypt/Random.php b/libs/phpseclib-1.0.6/Crypt/Random.php new file mode 100644 index 0000000..472d47c --- /dev/null +++ b/libs/phpseclib-1.0.6/Crypt/Random.php @@ -0,0 +1,334 @@ +<?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; + } +} |