Admin Control Panel v2.0

✎ Editing: Host.php ← Back

<?php

/**

* Validates a host according to the IPv4, IPv6 and DNS (future) specifications.

class HTMLPurifier_AttrDef_URI_Host extends HTMLPurifier_AttrDef

{

/**

* IPv4 sub-validator.

* @type HTMLPurifier_AttrDef_URI_IPv4

protected $ipv4;

/**

* IPv6 sub-validator.

* @type HTMLPurifier_AttrDef_URI_IPv6

protected $ipv6;

public function __construct()

{

$this->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

Cancel