1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
|
<?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
|
