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htmlpurifier/library/HTMLPurifier/AttrDef/URI/Host.php
Edward Z. Yang 974fe3f25e Optional support for IDNAs with PEAR Net_IDNA2
Signed-off-by: Edward Z. Yang <ezyang@mit.edu>
2012-01-06 05:28:00 -08:00

102 lines
3.5 KiB
PHP

<?php
/**
* Validates a host according to the IPv4, IPv6 and DNS (future) specifications.
*/
class HTMLPurifier_AttrDef_URI_Host extends HTMLPurifier_AttrDef
{
/**
* Instance of HTMLPurifier_AttrDef_URI_IPv4 sub-validator
*/
protected $ipv4;
/**
* Instance of HTMLPurifier_AttrDef_URI_IPv6 sub-validator
*/
protected $ipv6;
public function __construct() {
$this->ipv4 = new HTMLPurifier_AttrDef_URI_IPv4();
$this->ipv6 = new HTMLPurifier_AttrDef_URI_IPv6();
}
public function validate($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.
// The productions describing this are:
$a = '[a-z]'; // alpha
$an = '[a-z0-9]'; // alphanum
$and = '[a-z0-9-]'; // 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