/
Firexantixss.php
233 lines (192 loc) · 6.15 KB
/
Firexantixss.php
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
<?php
Class Firexantixss{
/*
*************************************************
* Library Name: Firexantixss *
* Author: Firman Santosa *
* Web: https://www.sifirman.com *
* Email: admin@sifirman.com *
* Github: https://github.com/firexsantos *
* Created on: October 25, 2019 02:03 WIB *
* Licence: GPL-MIT Licence *
*************************************************
*/
}
function antixss($string, $allowed_tags = array('a', 'em', 'strong', 'cite', 'blockquote', 'code', 'ul', 'ol', 'li', 'dl', 'dt', 'dd', 'p')) {
if (!validate_utf8($string)) {
return '';
}
_filter_xss_split($allowed_tags, TRUE);
$string = str_replace(chr(0), '', (string)$string);
$string = preg_replace('%&\s*\{[^}]*(\}\s*;?|$)%', '', $string);
$string = str_replace('&', '&', $string);
$string = preg_replace('/&#([0-9]+;)/', '&#\1', $string);
$string = preg_replace('/&#[Xx]0*((?:[0-9A-Fa-f]{2})+;)/', '&#x\1', $string);
$string = preg_replace('/&([A-Za-z][A-Za-z0-9]*;)/', '&\1', $string);
return preg_replace_callback('%
(
<(?=[^a-zA-Z!/]) # a lone <
| # or
<!--.*?--> # a comment
| # or
<[^>]*(>|$) # a string that starts with a <, up until the > or the end of the string
| # or
> # just a >
)%x', '_filter_xss_split', $string);
}
function _filter_xss_split($m, $store = FALSE) {
static $allowed_html;
if ($store) {
$allowed_html = array_flip($m);
return;
}
$string = $m[1];
if (substr($string, 0, 1) != '<') {
return '>';
}
elseif (strlen($string) == 1) {
return '<';
}
if (!preg_match('%^<\s*(/\s*)?([a-zA-Z0-9]+)([^>]*)>?|(<!--.*?-->)$%', $string, $matches)) {
return '';
}
$slash = trim($matches[1]);
$elem = &$matches[2];
$attrlist = &$matches[3];
$comment = &$matches[4];
if ($comment) {
$elem = '!--';
}
if (!isset($allowed_html[strtolower($elem)])) {
return '';
}
if ($comment) {
return $comment;
}
if ($slash != '') {
return "</$elem>";
}
$attrlist = preg_replace('%(\s?)/\s*$%', '\1', $attrlist, -1, $count);
$xhtml_slash = $count ? ' /' : '';
$attr2 = implode(' ', _filter_xss_attributes($attrlist));
$attr2 = preg_replace('/[<>]/', '', $attr2);
$attr2 = strlen($attr2) ? ' ' . $attr2 : '';
return "<$elem$attr2$xhtml_slash>";
}
function _filter_xss_attributes($attr) {
$attrarr = array();
$mode = 0;
$attrname = '';
while (strlen($attr) != 0) {
$working = 0;
switch ($mode) {
case 0:
if (preg_match('/^([-a-zA-Z]+)/', $attr, $match)) {
$attrname = strtolower($match[1]);
$skip = ($attrname == 'style' || substr($attrname, 0, 2) == 'on');
$working = $mode = 1;
$attr = preg_replace('/^[-a-zA-Z]+/', '', $attr);
}
break;
case 1:
if (preg_match('/^\s*=\s*/', $attr)) {
$working = 1; $mode = 2;
$attr = preg_replace('/^\s*=\s*/', '', $attr);
break;
}
if (preg_match('/^\s+/', $attr)) {
$working = 1; $mode = 0;
if (!$skip) {
$attrarr[] = $attrname;
}
$attr = preg_replace('/^\s+/', '', $attr);
}
break;
case 2:
if (preg_match('/^"([^"]*)"(\s+|$)/', $attr, $match)) {
$thisval = filter_xss_bad_protocol($match[1]);
if (!$skip) {
$attrarr[] = "$attrname=\"$thisval\"";
}
$working = 1;
$mode = 0;
$attr = preg_replace('/^"[^"]*"(\s+|$)/', '', $attr);
break;
}
if (preg_match("/^'([^']*)'(\s+|$)/", $attr, $match)) {
$thisval = filter_xss_bad_protocol($match[1]);
if (!$skip) {
$attrarr[] = "$attrname='$thisval'";
}
$working = 1; $mode = 0;
$attr = preg_replace("/^'[^']*'(\s+|$)/", '', $attr);
break;
}
if (preg_match("%^([^\s\"']+)(\s+|$)%", $attr, $match)) {
$thisval = filter_xss_bad_protocol($match[1]);
if (!$skip) {
$attrarr[] = "$attrname=\"$thisval\"";
}
$working = 1; $mode = 0;
$attr = preg_replace("%^[^\s\"']+(\s+|$)%", '', $attr);
}
break;
}
if ($working == 0) {
$attr = preg_replace('/
^
(
"[^"]*("|$) # - a string that starts with a double quote, up until the next double quote or the end of the string
| # or
\'[^\']*(\'|$)| # - a string that starts with a quote, up until the next quote or the end of the string
| # or
\S # - a non-whitespace character
)* # any number of the above three
\s* # any number of whitespaces
/x', '', $attr);
$mode = 0;
}
}
if ($mode == 1 && !$skip) {
$attrarr[] = $attrname;
}
return $attrarr;
}
function filter_xss_bad_protocol($string, $decode = TRUE) {
if ($decode) {
$string = decode_entities($string);
}
return check_plain(strip_dangerous_protocols($string));
}
function strip_dangerous_protocols($uri) {
static $allowed_protocols;
if (!isset($allowed_protocols)) {
$allowed_protocols = array_flip(array('ftp', 'http', 'https', 'irc', 'mailto', 'news', 'nntp', 'rtsp', 'sftp', 'ssh', 'tel', 'telnet', 'webcal'));
}
do {
$before = $uri;
$colonpos = strpos($uri, ':');
if ($colonpos > 0) {
$protocol = substr($uri, 0, $colonpos);
if (preg_match('![/?#]!', $protocol)) {
break;
}
if (!isset($allowed_protocols[strtolower($protocol)])) {
$uri = substr($uri, $colonpos + 1);
}
}
} while ($before != $uri);
return $uri;
}
function check_plain($text) {
return htmlspecialchars($text, ENT_QUOTES, 'UTF-8');
}
function decode_entities($text) {
return html_entity_decode($text, ENT_QUOTES, 'UTF-8');
}
function validate_utf8($text) {
if (strlen((string)$text) == 0) {
return TRUE;
}
return (preg_match('/^./us', $text) == 1);
}