ipv4 = new HTMLPurifier_AttrDef_URI_IPv4(); $this->ipv6 = new HTMLPurifier_AttrDef_URI_IPv6(); } /** * @param string $string * @param HTMLPurifier_Config $config * @param HTMLPurifier_Context $context * @return bool|string */ public function validate($string, $config, $context) { $length = strlen($string); // empty hostname is OK; it's usually semantically equivalent: // the default host as defined by a URI scheme is used: // // If the URI scheme defines a default for host, then that // default applies when the host subcomponent is undefined // or when the registered name is empty (zero length). if ($string === '') { return ''; } if ($length > 1 && $string[0] === '[' && $string[$length - 1] === ']') { //IPv6 $ip = substr($string, 1, $length - 2); $valid = $this->ipv6->validate($ip, $config, $context); if ($valid === false) { return false; } return '[' . $valid . ']'; } // need to do checks on unusual encodings too $ipv4 = $this->ipv4->validate($string, $config, $context); if ($ipv4 !== false) { return $ipv4; } // A regular domain name. // This doesn't match I18N domain names, but we don't have proper IRI support, // so force users to insert Punycode. // There is not a good sense in which underscores should be // allowed, since it's technically not! (And if you go as // far to allow everything as specified by the DNS spec... // well, that's literally everything, modulo some space limits // for the components and the overall name (which, by the way, // we are NOT checking!). So we (arbitrarily) decide this: // let's allow underscores wherever we would have allowed // hyphens, if they are enabled. This is a pretty good match // for browser behavior, for example, a large number of browsers // cannot handle foo_.example.com, but foo_bar.example.com is // fairly well supported. $underscore = $config->get('Core.AllowHostnameUnderscore') ? '_' : ''; // The productions describing this are: $a = '[a-z]'; // alpha $an = '[a-z0-9]'; // alphanum $and = "[a-z0-9-$underscore]"; // alphanum | "-" // domainlabel = alphanum | alphanum *( alphanum | "-" ) alphanum $domainlabel = "$an($and*$an)?"; // toplabel = alpha | alpha *( alphanum | "-" ) alphanum $toplabel = "$a($and*$an)?"; // hostname = *( domainlabel "." ) toplabel [ "." ] if (preg_match("/^($domainlabel\.)*$toplabel\.?$/i", $string)) { return $string; } // If we have Net_IDNA2 support, we can support IRIs by // punycoding them. (This is the most portable thing to do, // since otherwise we have to assume browsers support if ($config->get('Core.EnableIDNA')) { $idna = new Net_IDNA2(array('encoding' => 'utf8', 'overlong' => false, 'strict' => true)); // we need to encode each period separately $parts = explode('.', $string); try { $new_parts = array(); foreach ($parts as $part) { $encodable = false; for ($i = 0, $c = strlen($part); $i < $c; $i++) { if (ord($part[$i]) > 0x7a) { $encodable = true; break; } } if (!$encodable) { $new_parts[] = $part; } else { $new_parts[] = $idna->encode($part); } } $string = implode('.', $new_parts); if (preg_match("/^($domainlabel\.)*$toplabel\.?$/i", $string)) { return $string; } } catch (Exception $e) { // XXX error reporting } } return false; } } // vim: et sw=4 sts=4