109 lines
		
	
	
		
			3.2 KiB
		
	
	
	
		
			PHP
		
	
	
	
	
	
		
		
			
		
	
	
			109 lines
		
	
	
		
			3.2 KiB
		
	
	
	
		
			PHP
		
	
	
	
	
	
|   | <?php | ||
|  | 
 | ||
|  | /** | ||
|  |  * CryptUtil: A suite of wrapper utility functions for the OpenID | ||
|  |  * library. | ||
|  |  * | ||
|  |  * PHP versions 4 and 5 | ||
|  |  * | ||
|  |  * LICENSE: See the COPYING file included in this distribution. | ||
|  |  * | ||
|  |  * @access private | ||
|  |  * @package OpenID | ||
|  |  * @author JanRain, Inc. <openid@janrain.com> | ||
|  |  * @copyright 2005-2008 Janrain, Inc. | ||
|  |  * @license http://www.apache.org/licenses/LICENSE-2.0 Apache | ||
|  |  */ | ||
|  | 
 | ||
|  | if (!defined('Auth_OpenID_RAND_SOURCE')) { | ||
|  |     /** | ||
|  |      * The filename for a source of random bytes. Define this yourself | ||
|  |      * if you have a different source of randomness. | ||
|  |      */ | ||
|  |     define('Auth_OpenID_RAND_SOURCE', '/dev/urandom'); | ||
|  | } | ||
|  | 
 | ||
|  | class Auth_OpenID_CryptUtil { | ||
|  |     /** | ||
|  |      * Get the specified number of random bytes. | ||
|  |      * | ||
|  |      * Attempts to use a cryptographically secure (not predictable) | ||
|  |      * source of randomness if available. If there is no high-entropy | ||
|  |      * randomness source available, it will fail. As a last resort, | ||
|  |      * for non-critical systems, define | ||
|  |      * <code>Auth_OpenID_RAND_SOURCE</code> as <code>null</code>, and | ||
|  |      * the code will fall back on a pseudo-random number generator. | ||
|  |      * | ||
|  |      * @param int $num_bytes The length of the return value | ||
|  |      * @return string $bytes random bytes | ||
|  |      */ | ||
|  |     function getBytes($num_bytes) | ||
|  |     { | ||
|  |         static $f = null; | ||
|  |         $bytes = ''; | ||
|  |         if ($f === null) { | ||
|  |             if (Auth_OpenID_RAND_SOURCE === null) { | ||
|  |                 $f = false; | ||
|  |             } else { | ||
|  |                 $f = @fopen(Auth_OpenID_RAND_SOURCE, "r"); | ||
|  |                 if ($f === false) { | ||
|  |                     $msg = 'Define Auth_OpenID_RAND_SOURCE as null to ' . | ||
|  |                         ' continue with an insecure random number generator.'; | ||
|  |                     trigger_error($msg, E_USER_ERROR); | ||
|  |                 } | ||
|  |             } | ||
|  |         } | ||
|  |         if ($f === false) { | ||
|  |             // pseudorandom used
 | ||
|  |             $bytes = ''; | ||
|  |             for ($i = 0; $i < $num_bytes; $i += 4) { | ||
|  |                 $bytes .= pack('L', mt_rand()); | ||
|  |             } | ||
|  |             $bytes = substr($bytes, 0, $num_bytes); | ||
|  |         } else { | ||
|  |             $bytes = fread($f, $num_bytes); | ||
|  |         } | ||
|  |         return $bytes; | ||
|  |     } | ||
|  | 
 | ||
|  |     /** | ||
|  |      * Produce a string of length random bytes, chosen from chrs.  If | ||
|  |      * $chrs is null, the resulting string may contain any characters. | ||
|  |      * | ||
|  |      * @param integer $length The length of the resulting | ||
|  |      * randomly-generated string | ||
|  |      * @param string $chrs A string of characters from which to choose | ||
|  |      * to build the new string | ||
|  |      * @return string $result A string of randomly-chosen characters | ||
|  |      * from $chrs | ||
|  |      */ | ||
|  |     function randomString($length, $population = null) | ||
|  |     { | ||
|  |         if ($population === null) { | ||
|  |             return Auth_OpenID_CryptUtil::getBytes($length); | ||
|  |         } | ||
|  | 
 | ||
|  |         $popsize = strlen($population); | ||
|  | 
 | ||
|  |         if ($popsize > 256) { | ||
|  |             $msg = 'More than 256 characters supplied to ' . __FUNCTION__; | ||
|  |             trigger_error($msg, E_USER_ERROR); | ||
|  |         } | ||
|  | 
 | ||
|  |         $duplicate = 256 % $popsize; | ||
|  | 
 | ||
|  |         $str = ""; | ||
|  |         for ($i = 0; $i < $length; $i++) { | ||
|  |             do { | ||
|  |                 $n = ord(Auth_OpenID_CryptUtil::getBytes(1)); | ||
|  |             } while ($n < $duplicate); | ||
|  | 
 | ||
|  |             $n %= $popsize; | ||
|  |             $str .= $population[$n]; | ||
|  |         } | ||
|  | 
 | ||
|  |         return $str; | ||
|  |     } | ||
|  | } | ||
|  | 
 | ||
|  | ?>
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