1<?php
2
3/**
4 * Validates an IPv6 address.
5 * @author Feyd @ forums.devnetwork.net (public domain)
6 * @note This function requires brackets to have been removed from address
7 *       in URI.
8 */
9class HTMLPurifier_AttrDef_URI_IPv6 extends HTMLPurifier_AttrDef_URI_IPv4
10{
11
12    /**
13     * @param string $aIP
14     * @param HTMLPurifier_Config $config
15     * @param HTMLPurifier_Context $context
16     * @return bool|string
17     */
18    public function validate($aIP, $config, $context)
19    {
20        if (!$this->ip4) {
21            $this->_loadRegex();
22        }
23
24        $original = $aIP;
25
26        $hex = '[0-9a-fA-F]';
27        $blk = '(?:' . $hex . '{1,4})';
28        $pre = '(?:/(?:12[0-8]|1[0-1][0-9]|[1-9][0-9]|[0-9]))'; // /0 - /128
29
30        //      prefix check
31        if (strpos($aIP, '/') !== false) {
32            if (preg_match('#' . $pre . '$#s', $aIP, $find)) {
33                $aIP = substr($aIP, 0, 0 - strlen($find[0]));
34                unset($find);
35            } else {
36                return false;
37            }
38        }
39
40        //      IPv4-compatiblity check
41        if (preg_match('#(?<=:' . ')' . $this->ip4 . '$#s', $aIP, $find)) {
42            $aIP = substr($aIP, 0, 0 - strlen($find[0]));
43            $ip = explode('.', $find[0]);
44            $ip = array_map('dechex', $ip);
45            $aIP .= $ip[0] . $ip[1] . ':' . $ip[2] . $ip[3];
46            unset($find, $ip);
47        }
48
49        //      compression check
50        $aIP = explode('::', $aIP);
51        $c = count($aIP);
52        if ($c > 2) {
53            return false;
54        } elseif ($c == 2) {
55            list($first, $second) = $aIP;
56            $first = explode(':', $first);
57            $second = explode(':', $second);
58
59            if (count($first) + count($second) > 8) {
60                return false;
61            }
62
63            while (count($first) < 8) {
64                array_push($first, '0');
65            }
66
67            array_splice($first, 8 - count($second), 8, $second);
68            $aIP = $first;
69            unset($first, $second);
70        } else {
71            $aIP = explode(':', $aIP[0]);
72        }
73        $c = count($aIP);
74
75        if ($c != 8) {
76            return false;
77        }
78
79        //      All the pieces should be 16-bit hex strings. Are they?
80        foreach ($aIP as $piece) {
81            if (!preg_match('#^[0-9a-fA-F]{4}$#s', sprintf('%04s', $piece))) {
82                return false;
83            }
84        }
85        return $original;
86    }
87}
88
89// vim: et sw=4 sts=4
90