lib/htmlpurifier/HTMLPurifier/PercentEncoder.php

   1 <?php
   2
   3 /**
   4  * Class that handles operations involving percent-encoding in URIs.
   5  */
   6 class HTMLPurifier_PercentEncoder
   7 {
   8
   9     /**
  10      * Fix up percent-encoding by decoding unreserved characters and normalizing
  11      * @param $string String to normalize
  12      */
  13     function normalize($string) {
  14         if ($string == '') return '';
  15         $parts = explode('%', $string);
  16         $ret = array_shift($parts);
  17         foreach ($parts as $part) {
  18             $length = strlen($part);
  19             if ($length < 2) {
  20                 $ret .= '%25' . $part;
  21                 continue;
  22             }
  23             $encoding = substr($part, 0, 2);
  24             $text     = substr($part, 2);
  25             if (!ctype_xdigit($encoding)) {
  26                 $ret .= '%25' . $part;
  27                 continue;
  28             }
  29             $int = hexdec($encoding);
  30             if (
  31                 ($int >= 48 && $int <= 57) || // digits
  32                 ($int >= 65 && $int <= 90) || // uppercase letters
  33                 ($int >= 97 && $int <= 122) || // lowercase letters
  34                 $int == 126 || $int == 45 || $int == 46 || $int == 95 // ~-._
  35             ) {
  36                 $ret .= chr($int) . $text;
  37                 continue;
  38             }
  39             $encoding = strtoupper($encoding);
  40             $ret .= '%' . $encoding . $text;
  41         }
  42         return $ret;
  43     }
  44
  45 }
  46
  47 ?>