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
|
<?php
class HTMLPurifier_URIFilter_Munge extends HTMLPurifier_URIFilter
{
/**
* @type string
*/
public $name = 'Munge';
/**
* @type bool
*/
public $post = true;
/**
* @type string
*/
private $target;
/**
* @type HTMLPurifier_URIParser
*/
private $parser;
/**
* @type bool
*/
private $doEmbed;
/**
* @type string
*/
private $secretKey;
/**
* @type array
*/
protected $replace = array();
/**
* @param HTMLPurifier_Config $config
* @return bool
*/
public function prepare($config)
{
$this->target = $config->get('URI.' . $this->name);
$this->parser = new HTMLPurifier_URIParser();
$this->doEmbed = $config->get('URI.MungeResources');
$this->secretKey = $config->get('URI.MungeSecretKey');
if ($this->secretKey && !function_exists('hash_hmac')) {
throw new Exception("Cannot use %URI.MungeSecretKey without hash_hmac support.");
}
return true;
}
/**
* @param HTMLPurifier_URI $uri
* @param HTMLPurifier_Config $config
* @param HTMLPurifier_Context $context
* @return bool
*/
public function filter(&$uri, $config, $context)
{
if ($context->get('EmbeddedURI', true) && !$this->doEmbed) {
return true;
}
$scheme_obj = $uri->getSchemeObj($config, $context);
if (!$scheme_obj) {
return true;
} // ignore unknown schemes, maybe another postfilter did it
if (!$scheme_obj->browsable) {
return true;
} // ignore non-browseable schemes, since we can't munge those in a reasonable way
if ($uri->isBenign($config, $context)) {
return true;
} // don't redirect if a benign URL
$this->makeReplace($uri, $config, $context);
$this->replace = array_map('rawurlencode', $this->replace);
$new_uri = strtr($this->target, $this->replace);
$new_uri = $this->parser->parse($new_uri);
// don't redirect if the target host is the same as the
// starting host
if ($uri->host === $new_uri->host) {
return true;
}
$uri = $new_uri; // overwrite
return true;
}
/**
* @param HTMLPurifier_URI $uri
* @param HTMLPurifier_Config $config
* @param HTMLPurifier_Context $context
*/
protected function makeReplace($uri, $config, $context)
{
$string = $uri->toString();
// always available
$this->replace['%s'] = $string;
$this->replace['%r'] = $context->get('EmbeddedURI', true);
$token = $context->get('CurrentToken', true);
$this->replace['%n'] = $token ? $token->name : null;
$this->replace['%m'] = $context->get('CurrentAttr', true);
$this->replace['%p'] = $context->get('CurrentCSSProperty', true);
// not always available
if ($this->secretKey) {
$this->replace['%t'] = hash_hmac("sha256", $string, $this->secretKey);
}
}
}
// vim: et sw=4 sts=4
|
