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htmlpurifier/library/HTMLPurifier/URISchemeRegistry.php
2006-08-12 17:12:27 +00:00

77 lines
2.8 KiB
PHP

<?php
HTMLPurifier_ConfigDef::define(
'URI', 'AllowedSchemes', array(
'http' => true, // "Hypertext Transfer Protocol", nuf' said
'https' => true, // HTTP over SSL (Secure Socket Layer)
// quite useful, but not necessary
'mailto' => true,// Email
'ftp' => true, // "File Transfer Protocol"
'irc' => true, // "Internet Relay Chat", usually needs another app
// for Usenet, these two are similar, but distinct
'nntp' => true, // individual Netnews articles
'news' => true // newsgroup or individual Netnews articles),
),
'Whitelist that defines the schemes that a URI is allowed to have. This '.
'prevents XSS attacks from using pseudo-schemes like javascript or mocha.'
);
HTMLPurifier_ConfigDef::define(
'URI', 'OverrideAllowedSchemes', true,
'If this is set to true (which it is by default), you can override '.
'%URI.AllowedSchemes by simply registering a HTMLPurifier_URIScheme '.
'to the registry. If false, you will also have to update that directive '.
'in order to add more schemes.'
);
class HTMLPurifier_URISchemeRegistry
{
// pass a registry object $prototype with a compatible interface and
// the function will copy it and return it all further times.
// pass bool true to reset to the default registry
function &instance($prototype = null) {
static $instance = null;
if ($prototype !== null) {
$instance = $prototype;
} elseif ($instance === null || $prototype == true) {
$instance = new HTMLPurifier_URISchemeRegistry();
}
return $instance;
}
var $schemes = array();
var $_scheme_dir = null;
function &getScheme($scheme, $config = null) {
if (!$config) $config = HTMLPurifier_Config::createDefault();
$null = null; // for the sake of passing by reference
// important, otherwise attacker could include arbitrary file
$allowed_schemes = $config->get('URI', 'AllowedSchemes');
if (!$config->get('URI', 'OverrideAllowedSchemes') &&
!isset($allowed_schemes[$scheme])
) {
return $null;
}
if (isset($this->schemes[$scheme])) return $this->schemes[$scheme];
if (empty($this->_dir)) $this->_dir = dirname(__FILE__) . '/URIScheme/';
if (!isset($allowed_schemes[$scheme])) return $null;
@include_once $this->_dir . $scheme . '.php';
$class = 'HTMLPurifier_URIScheme_' . $scheme;
if (!class_exists($class)) return $null;
$this->schemes[$scheme] = new $class();
return $this->schemes[$scheme];
}
function register($scheme, &$scheme_obj) {
$this->schemes[$scheme] =& $scheme_obj;
}
}
?>