library/HTMLPurifier/URIFilter/Munge.php

   1 <?php
   2
   3 class HTMLPurifier_URIFilter_Munge extends HTMLPurifier_URIFilter
   4 {
   5     public $name = 'Munge';
   6     public $post = true;
   7     private $target, $parser, $doEmbed, $secretKey;
   8
   9     protected $replace = array();
  10
  11     public function prepare($config) {
  12         $this->target    = $config->get('URI.' . $this->name);
  13         $this->parser    = new HTMLPurifier_URIParser();
  14         $this->doEmbed   = $config->get('URI.MungeResources');
  15         $this->secretKey = $config->get('URI.MungeSecretKey');
  16         return true;
  17     }
  18     public function filter(&$uri, $config, $context) {
  19         if ($context->get('EmbeddedURI', true) && !$this->doEmbed) return true;
  20
  21         $scheme_obj = $uri->getSchemeObj($config, $context);
  22         if (!$scheme_obj) return true; // ignore unknown schemes, maybe another postfilter did it
  23         if (!$scheme_obj->browsable) return true; // ignore non-browseable schemes, since we can't munge those in a reasonable way
  24         if ($uri->isBenign($config, $context)) return true; // don't redirect if a benign URL
  25
  26         $this->makeReplace($uri, $config, $context);
  27         $this->replace = array_map('rawurlencode', $this->replace);
  28
  29         $new_uri = strtr($this->target, $this->replace);
  30         $new_uri = $this->parser->parse($new_uri);
  31         // don't redirect if the target host is the same as the
  32         // starting host
  33         if ($uri->host === $new_uri->host) return true;
  34         $uri = $new_uri; // overwrite
  35         return true;
  36     }
  37
  38     protected function makeReplace($uri, $config, $context) {
  39         $string = $uri->toString();
  40         // always available
  41         $this->replace['%s'] = $string;
  42         $this->replace['%r'] = $context->get('EmbeddedURI', true);
  43         $token = $context->get('CurrentToken', true);
  44         $this->replace['%n'] = $token ? $token->name : null;
  45         $this->replace['%m'] = $context->get('CurrentAttr', true);
  46         $this->replace['%p'] = $context->get('CurrentCSSProperty', true);
  47         // not always available
  48         if ($this->secretKey) $this->replace['%t'] = sha1($this->secretKey . ':' . $string);
  49     }
  50
  51 }
  52
  53 // vim: et sw=4 sts=4