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khosb/includes/kohana/system/classes/Kohana/Security.php
2013-10-10 13:44:53 +11:00

104 lines
2.4 KiB
PHP

<?php defined('SYSPATH') OR die('No direct script access.');
/**
* Security helper class.
*
* @package Kohana
* @category Security
* @author Kohana Team
* @copyright (c) 2007-2012 Kohana Team
* @license http://kohanaframework.org/license
*/
class Kohana_Security {
/**
* @var string key name used for token storage
*/
public static $token_name = 'security_token';
/**
* Generate and store a unique token which can be used to help prevent
* [CSRF](http://wikipedia.org/wiki/Cross_Site_Request_Forgery) attacks.
*
* $token = Security::token();
*
* You can insert this token into your forms as a hidden field:
*
* echo Form::hidden('csrf', Security::token());
*
* And then check it when using [Validation]:
*
* $array->rules('csrf', array(
* 'not_empty' => NULL,
* 'Security::check' => NULL,
* ));
*
* This provides a basic, but effective, method of preventing CSRF attacks.
*
* @param boolean $new force a new token to be generated?
* @return string
* @uses Session::instance
*/
public static function token($new = FALSE)
{
$session = Session::instance();
// Get the current token
$token = $session->get(Security::$token_name);
if ($new === TRUE OR ! $token)
{
// Generate a new unique token
$token = sha1(uniqid(NULL, TRUE));
// Store the new token
$session->set(Security::$token_name, $token);
}
return $token;
}
/**
* Check that the given token matches the currently stored security token.
*
* if (Security::check($token))
* {
* // Pass
* }
*
* @param string $token token to check
* @return boolean
* @uses Security::token
*/
public static function check($token)
{
return Security::token() === $token;
}
/**
* Remove image tags from a string.
*
* $str = Security::strip_image_tags($str);
*
* @param string $str string to sanitize
* @return string
*/
public static function strip_image_tags($str)
{
return preg_replace('#<img\s.*?(?:src\s*=\s*["\']?([^"\'<>\s]*)["\']?[^>]*)?>#is', '$1', $str);
}
/**
* Encodes PHP tags in a string.
*
* $str = Security::encode_php_tags($str);
*
* @param string $str string to sanitize
* @return string
*/
public static function encode_php_tags($str)
{
return str_replace(array('<?', '?>'), array('&lt;?', '?&gt;'), $str);
}
} // End security