1: <?php
2:
3: /**
4: * Validates a host according to the IPv4, IPv6 and DNS (future) specifications.
5: */
6: class HTMLPurifier_AttrDef_URI_Host extends HTMLPurifier_AttrDef
7: {
8:
9: /**
10: * Instance of HTMLPurifier_AttrDef_URI_IPv4 sub-validator
11: */
12: protected $ipv4;
13:
14: /**
15: * Instance of HTMLPurifier_AttrDef_URI_IPv6 sub-validator
16: */
17: protected $ipv6;
18:
19: public function __construct() {
20: $this->ipv4 = new HTMLPurifier_AttrDef_URI_IPv4();
21: $this->ipv6 = new HTMLPurifier_AttrDef_URI_IPv6();
22: }
23:
24: public function validate($string, $config, $context) {
25: $length = strlen($string);
26: // empty hostname is OK; it's usually semantically equivalent:
27: // the default host as defined by a URI scheme is used:
28: //
29: // If the URI scheme defines a default for host, then that
30: // default applies when the host subcomponent is undefined
31: // or when the registered name is empty (zero length).
32: if ($string === '') return '';
33: if ($length > 1 && $string[0] === '[' && $string[$length-1] === ']') {
34: //IPv6
35: $ip = substr($string, 1, $length - 2);
36: $valid = $this->ipv6->validate($ip, $config, $context);
37: if ($valid === false) return false;
38: return '['. $valid . ']';
39: }
40:
41: // need to do checks on unusual encodings too
42: $ipv4 = $this->ipv4->validate($string, $config, $context);
43: if ($ipv4 !== false) return $ipv4;
44:
45: // A regular domain name.
46:
47: // This breaks I18N domain names, but we don't have proper IRI support,
48: // so force users to insert Punycode. If there's complaining we'll
49: // try to fix things into an international friendly form.
50:
51: // The productions describing this are:
52: $a = '[a-z]'; // alpha
53: $an = '[a-z0-9]'; // alphanum
54: $and = '[a-z0-9-]'; // alphanum | "-"
55: // domainlabel = alphanum | alphanum *( alphanum | "-" ) alphanum
56: $domainlabel = "$an($and*$an)?";
57: // toplabel = alpha | alpha *( alphanum | "-" ) alphanum
58: $toplabel = "$a($and*$an)?";
59: // hostname = *( domainlabel "." ) toplabel [ "." ]
60: $match = preg_match("/^($domainlabel\.)*$toplabel\.?$/i", $string);
61: if (!$match) return false;
62:
63: return $string;
64: }
65:
66: }
67:
68: // vim: et sw=4 sts=4
69: