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
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
|
<?php
/*! @mainpage
*
* HTML Purifier is an HTML filter that will take an arbitrary snippet of
* HTML and rigorously test, validate and filter it into a version that
* is safe for output onto webpages. It achieves this by:
*
* -# Lexing (parsing into tokens) the document,
* -# Executing various strategies on the tokens:
* -# Removing all elements not in the whitelist,
* -# Making the tokens well-formed,
* -# Fixing the nesting of the nodes, and
* -# Validating attributes of the nodes; and
* -# Generating HTML from the purified tokens.
*
* However, most users will only need to interface with the HTMLPurifier
* and HTMLPurifier_Config.
*/
/*
HTML Purifier 4.1.1 - Standards Compliant HTML Filtering
Copyright (C) 2006-2008 Edward Z. Yang
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/**
* Facade that coordinates HTML Purifier's subsystems in order to purify HTML.
*
* @note There are several points in which configuration can be specified
* for HTML Purifier. The precedence of these (from lowest to
* highest) is as follows:
* -# Instance: new HTMLPurifier($config)
* -# Invocation: purify($html, $config)
* These configurations are entirely independent of each other and
* are *not* merged (this behavior may change in the future).
*
* @todo We need an easier way to inject strategies using the configuration
* object.
*/
class HTMLPurifier
{
/** Version of HTML Purifier */
public $version = '4.1.1';
/** Constant with version of HTML Purifier */
const VERSION = '4.1.1';
/** Global configuration object */
public $config;
/** Array of extra HTMLPurifier_Filter objects to run on HTML, for backwards compatibility */
private $filters = array();
/** Single instance of HTML Purifier */
private static $instance;
protected $strategy, $generator;
/**
* Resultant HTMLPurifier_Context of last run purification. Is an array
* of contexts if the last called method was purifyArray().
*/
public $context;
/**
* Initializes the purifier.
* @param $config Optional HTMLPurifier_Config object for all instances of
* the purifier, if omitted, a default configuration is
* supplied (which can be overridden on a per-use basis).
* The parameter can also be any type that
* HTMLPurifier_Config::create() supports.
*/
public function __construct($config = null) {
$this->config = HTMLPurifier_Config::create($config);
$this->strategy = new HTMLPurifier_Strategy_Core();
}
/**
* Adds a filter to process the output. First come first serve
* @param $filter HTMLPurifier_Filter object
*/
public function addFilter($filter) {
trigger_error('HTMLPurifier->addFilter() is deprecated, use configuration directives in the Filter namespace or Filter.Custom', E_USER_WARNING);
$this->filters[] = $filter;
}
/**
* Filters an HTML snippet/document to be XSS-free and standards-compliant.
*
* @param $html String of HTML to purify
* @param $config HTMLPurifier_Config object for this operation, if omitted,
* defaults to the config object specified during this
* object's construction. The parameter can also be any type
* that HTMLPurifier_Config::create() supports.
* @return Purified HTML
*/
public function purify($html, $config = null) {
// :TODO: make the config merge in, instead of replace
$config = $config ? HTMLPurifier_Config::create($config) : $this->config;
// implementation is partially environment dependant, partially
// configuration dependant
$lexer = HTMLPurifier_Lexer::create($config);
$context = new HTMLPurifier_Context();
// setup HTML generator
$this->generator = new HTMLPurifier_Generator($config, $context);
$context->register('Generator', $this->generator);
// set up global context variables
if ($config->get('Core.CollectErrors')) {
// may get moved out if other facilities use it
$language_factory = HTMLPurifier_LanguageFactory::instance();
$language = $language_factory->create($config, $context);
$context->register('Locale', $language);
$error_collector = new HTMLPurifier_ErrorCollector($context);
$context->register('ErrorCollector', $error_collector);
}
// setup id_accumulator context, necessary due to the fact that
// AttrValidator can be called from many places
$id_accumulator = HTMLPurifier_IDAccumulator::build($config, $context);
$context->register('IDAccumulator', $id_accumulator);
$html = HTMLPurifier_Encoder::convertToUTF8($html, $config, $context);
// setup filters
$filter_flags = $config->getBatch('Filter');
$custom_filters = $filter_flags['Custom'];
unset($filter_flags['Custom']);
$filters = array();
foreach ($filter_flags as $filter => $flag) {
if (!$flag) continue;
if (strpos($filter, '.') !== false) continue;
$class = "HTMLPurifier_Filter_$filter";
$filters[] = new $class;
}
foreach ($custom_filters as $filter) {
// maybe "HTMLPurifier_Filter_$filter", but be consistent with AutoFormat
$filters[] = $filter;
}
$filters = array_merge($filters, $this->filters);
// maybe prepare(), but later
for ($i = 0, $filter_size = count($filters); $i < $filter_size; $i++) {
$html = $filters[$i]->preFilter($html, $config, $context);
}
// purified HTML
$html =
$this->generator->generateFromTokens(
// list of tokens
$this->strategy->execute(
// list of un-purified tokens
$lexer->tokenizeHTML(
// un-purified HTML
$html, $config, $context
),
$config, $context
)
);
for ($i = $filter_size - 1; $i >= 0; $i--) {
$html = $filters[$i]->postFilter($html, $config, $context);
}
$html = HTMLPurifier_Encoder::convertFromUTF8($html, $config, $context);
$this->context =& $context;
return $html;
}
/**
* Filters an array of HTML snippets
* @param $config Optional HTMLPurifier_Config object for this operation.
* See HTMLPurifier::purify() for more details.
* @return Array of purified HTML
*/
public function purifyArray($array_of_html, $config = null) {
$context_array = array();
foreach ($array_of_html as $key => $html) {
$array_of_html[$key] = $this->purify($html, $config);
$context_array[$key] = $this->context;
}
$this->context = $context_array;
return $array_of_html;
}
/**
* Singleton for enforcing just one HTML Purifier in your system
* @param $prototype Optional prototype HTMLPurifier instance to
* overload singleton with, or HTMLPurifier_Config
* instance to configure the generated version with.
*/
public static function instance($prototype = null) {
if (!self::$instance || $prototype) {
if ($prototype instanceof HTMLPurifier) {
self::$instance = $prototype;
} elseif ($prototype) {
self::$instance = new HTMLPurifier($prototype);
} else {
self::$instance = new HTMLPurifier();
}
}
return self::$instance;
}
/**
* @note Backwards compatibility, see instance()
*/
public static function getInstance($prototype = null) {
return HTMLPurifier::instance($prototype);
}
}
// vim: et sw=4 sts=4
|
