lib/htmlpurifier/HTMLPurifier/AttrDef/CSS/URI.php

   1 <?php
   2
   3 require_once 'HTMLPurifier/AttrDef/URI.php';
   4
   5 /**
   6  * Validates a URI in CSS syntax, which uses url('http://example.com')
   7  * @note While theoretically speaking a URI in a CSS document could
   8  *       be non-embedded, as of CSS2 there is no such usage so we're
   9  *       generalizing it. This may need to be changed in the future.
  10  * @warning Since HTMLPurifier_AttrDef_CSS blindly uses semicolons as
  11  *          the separator, you cannot put a literal semicolon in
  12  *          in the URI. Try percent encoding it, in that case.
  13  */
  14 class HTMLPurifier_AttrDef_CSS_URI extends HTMLPurifier_AttrDef_URI
  15 {
  16
  17     function HTMLPurifier_AttrDef_CSS_URI() {
  18         $this->HTMLPurifier_AttrDef_URI(true); // always embedded
  19     }
  20
  21     function validate($uri_string, $config, &$context) {
  22         // parse the URI out of the string and then pass it onto
  23         // the parent object
  24
  25         $uri_string = $this->parseCDATA($uri_string);
  26         if (strpos($uri_string, 'url(') !== 0) return false;
  27         $uri_string = substr($uri_string, 4);
  28         $new_length = strlen($uri_string) - 1;
  29         if ($uri_string[$new_length] != ')') return false;
  30         $uri = trim(substr($uri_string, 0, $new_length));
  31
  32         if (isset($uri[0]) && ($uri[0] == "'" || $uri[0] == '"')) {
  33             $quote = $uri[0];
  34             $new_length = strlen($uri) - 1;
  35             if ($uri[$new_length] !== $quote) return false;
  36             $uri = substr($uri, 1, $new_length - 1);
  37         }
  38
  39         $keys   = array(  '(',   ')',   ',',   ' ',   '"',   "'");
  40         $values = array('\\(', '\\)', '\\,', '\\ ', '\\"', "\\'");
  41         $uri = str_replace($values, $keys, $uri);
  42
  43         $result = parent::validate($uri, $config, $context);
  44
  45         if ($result === false) return false;
  46
  47         // escape necessary characters according to CSS spec
  48         // except for the comma, none of these should appear in the
  49         // URI at all
  50         $result = str_replace($keys, $values, $result);
  51
  52         return "url($result)";
  53
  54     }
  55
  56 }
  57
  58 ?>