library/HTMLPurifier/URIScheme.php

   1 <?php
   2
   3 /**
   4  * Validator for the components of a URI for a specific scheme
   5  */
   6 abstract class HTMLPurifier_URIScheme
   7 {
   8
   9     /**
  10      * Scheme's default port (integer). If an explicit port number is
  11      * specified that coincides with the default port, it will be
  12      * elided.
  13      * @type int
  14      */
  15     public $default_port = null;
  16
  17     /**
  18      * Whether or not URIs of this scheme are locatable by a browser
  19      * http and ftp are accessible, while mailto and news are not.
  20      * @type bool
  21      */
  22     public $browsable = false;
  23
  24     /**
  25      * Whether or not data transmitted over this scheme is encrypted.
  26      * https is secure, http is not.
  27      * @type bool
  28      */
  29     public $secure = false;
  30
  31     /**
  32      * Whether or not the URI always uses <hier_part>, resolves edge cases
  33      * with making relative URIs absolute
  34      * @type bool
  35      */
  36     public $hierarchical = false;
  37
  38     /**
  39      * Whether or not the URI may omit a hostname when the scheme is
  40      * explicitly specified, ala file:///path/to/file. As of writing,
  41      * 'file' is the only scheme that browsers support his properly.
  42      * @type bool
  43      */
  44     public $may_omit_host = false;
  45
  46     /**
  47      * Validates the components of a URI for a specific scheme.
  48      * @param HTMLPurifier_URI $uri Reference to a HTMLPurifier_URI object
  49      * @param HTMLPurifier_Config $config
  50      * @param HTMLPurifier_Context $context
  51      * @return bool success or failure
  52      */
  53     abstract public function doValidate(&$uri, $config, $context);
  54
  55     /**
  56      * Public interface for validating components of a URI.  Performs a
  57      * bunch of default actions. Don't overload this method.
  58      * @param HTMLPurifier_URI $uri Reference to a HTMLPurifier_URI object
  59      * @param HTMLPurifier_Config $config
  60      * @param HTMLPurifier_Context $context
  61      * @return bool success or failure
  62      */
  63     public function validate(&$uri, $config, $context)
  64     {
  65         if ($this->default_port == $uri->port) {
  66             $uri->port = null;
  67         }
  68         // kludge: browsers do funny things when the scheme but not the
  69         // authority is set
  70         if (!$this->may_omit_host &&
  71             // if the scheme is present, a missing host is always in error
  72             (!is_null($uri->scheme) && ($uri->host === '' || is_null($uri->host))) ||
  73             // if the scheme is not present, a *blank* host is in error,
  74             // since this translates into '///path' which most browsers
  75             // interpret as being 'http://path'.
  76             (is_null($uri->scheme) && $uri->host === '')
  77         ) {
  78             do {
  79                 if (is_null($uri->scheme)) {
  80                     if (substr($uri->path, 0, 2) != '//') {
  81                         $uri->host = null;
  82                         break;
  83                     }
  84                     // URI is '////path', so we cannot nullify the
  85                     // host to preserve semantics.  Try expanding the
  86                     // hostname instead (fall through)
  87                 }
  88                 // first see if we can manually insert a hostname
  89                 $host = $config->get('URI.Host');
  90                 if (!is_null($host)) {
  91                     $uri->host = $host;
  92                 } else {
  93                     // we can't do anything sensible, reject the URL.
  94                     return false;
  95                 }
  96             } while (false);
  97         }
  98         return $this->doValidate($uri, $config, $context);
  99     }
 100 }
 101
 102 // vim: et sw=4 sts=4