library/HTMLPurifier/URISchemeRegistry.php

   1 <?php
   2
   3 /**
   4  * Registry for retrieving specific URI scheme validator objects.
   5  */
   6 class HTMLPurifier_URISchemeRegistry
   7 {
   8
   9     /**
  10      * Retrieve sole instance of the registry.
  11      * @param $prototype Optional prototype to overload sole instance with,
  12      *                   or bool true to reset to default registry.
  13      * @note Pass a registry object $prototype with a compatible interface and
  14      *       the function will copy it and return it all further times.
  15      */
  16     public static function instance($prototype = null) {
  17         static $instance = null;
  18         if ($prototype !== null) {
  19             $instance = $prototype;
  20         } elseif ($instance === null || $prototype == true) {
  21             $instance = new HTMLPurifier_URISchemeRegistry();
  22         }
  23         return $instance;
  24     }
  25
  26     /**
  27      * Cache of retrieved schemes.
  28      */
  29     protected $schemes = array();
  30
  31     /**
  32      * Retrieves a scheme validator object
  33      * @param $scheme String scheme name like http or mailto
  34      * @param $config HTMLPurifier_Config object
  35      * @param $config HTMLPurifier_Context object
  36      */
  37     public function getScheme($scheme, $config, $context) {
  38         if (!$config) $config = HTMLPurifier_Config::createDefault();
  39
  40         // important, otherwise attacker could include arbitrary file
  41         $allowed_schemes = $config->get('URI.AllowedSchemes');
  42         if (!$config->get('URI.OverrideAllowedSchemes') &&
  43             !isset($allowed_schemes[$scheme])
  44         ) {
  45             return;
  46         }
  47
  48         if (isset($this->schemes[$scheme])) return $this->schemes[$scheme];
  49         if (!isset($allowed_schemes[$scheme])) return;
  50
  51         $class = 'HTMLPurifier_URIScheme_' . $scheme;
  52         if (!class_exists($class)) return;
  53         $this->schemes[$scheme] = new $class();
  54         return $this->schemes[$scheme];
  55     }
  56
  57     /**
  58      * Registers a custom scheme to the cache, bypassing reflection.
  59      * @param $scheme Scheme name
  60      * @param $scheme_obj HTMLPurifier_URIScheme object
  61      */
  62     public function register($scheme, $scheme_obj) {
  63         $this->schemes[$scheme] = $scheme_obj;
  64     }
  65
  66 }
  67
  68 // vim: et sw=4 sts=4