forked from openid/php-openid
/
Parse.php
352 lines (306 loc) · 10.7 KB
/
Parse.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
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
<?php
/**
* This module implements a VERY limited parser that finds <link> tags
* in the head of HTML or XHTML documents and parses out their
* attributes according to the OpenID spec. It is a liberal parser,
* but it requires these things from the data in order to work:
*
* - There must be an open <html> tag
*
* - There must be an open <head> tag inside of the <html> tag
*
* - Only <link>s that are found inside of the <head> tag are parsed
* (this is by design)
*
* - The parser follows the OpenID specification in resolving the
* attributes of the link tags. This means that the attributes DO
* NOT get resolved as they would by an XML or HTML parser. In
* particular, only certain entities get replaced, and href
* attributes do not get resolved relative to a base URL.
*
* From http://openid.net/specs.bml:
*
* - The openid.server URL MUST be an absolute URL. OpenID consumers
* MUST NOT attempt to resolve relative URLs.
*
* - The openid.server URL MUST NOT include entities other than &,
* <, >, and ".
*
* The parser ignores SGML comments and <![CDATA[blocks]]>. Both kinds
* of quoting are allowed for attributes.
*
* The parser deals with invalid markup in these ways:
*
* - Tag names are not case-sensitive
*
* - The <html> tag is accepted even when it is not at the top level
*
* - The <head> tag is accepted even when it is not a direct child of
* the <html> tag, but a <html> tag must be an ancestor of the
* <head> tag
*
* - <link> tags are accepted even when they are not direct children
* of the <head> tag, but a <head> tag must be an ancestor of the
* <link> tag
*
* - If there is no closing tag for an open <html> or <head> tag, the
* remainder of the document is viewed as being inside of the
* tag. If there is no closing tag for a <link> tag, the link tag is
* treated as a short tag. Exceptions to this rule are that <html>
* closes <html> and <body> or <head> closes <head>
*
* - Attributes of the <link> tag are not required to be quoted.
*
* - In the case of duplicated attribute names, the attribute coming
* last in the tag will be the value returned.
*
* - Any text that does not parse as an attribute within a link tag
* will be ignored. (e.g. <link pumpkin rel='openid.server' /> will
* ignore pumpkin)
*
* - If there are more than one <html> or <head> tag, the parser only
* looks inside of the first one.
*
* - The contents of <script> tags are ignored entirely, except
* unclosed <script> tags. Unclosed <script> tags are ignored.
*
* - Any other invalid markup is ignored, including unclosed SGML
* comments and unclosed <![CDATA[blocks.
*
* PHP versions 4 and 5
*
* LICENSE: See the COPYING file included in this distribution.
*
* @access private
* @package OpenID
* @author JanRain, Inc. <openid@janrain.com>
* @copyright 2005-2008 Janrain, Inc.
* @license http://www.apache.org/licenses/LICENSE-2.0 Apache
*/
/**
* Require Auth_OpenID::arrayGet().
*/
require_once "Auth/OpenID.php";
class Auth_OpenID_Parse {
/**
* Specify some flags for use with regex matching.
*/
var $_re_flags = "si";
/**
* Stuff to remove before we start looking for tags
*/
var $_removed_re =
"<!--.*?-->|<!\[CDATA\[.*?\]\]>|<script\b(?!:)[^>]*>.*?<\/script>";
/**
* Starts with the tag name at a word boundary, where the tag name
* is not a namespace
*/
var $_tag_expr = "<%s\b(?!:)([^>]*?)(?:\/>|>(.*?)(?:<\/?%s\s*>|\Z))";
var $_attr_find = '\b(\w+)=("[^"]*"|\'[^\']*\'|[^\'"\s\/<>]+)';
var $_open_tag_expr = "<%s\b";
var $_close_tag_expr = "<((\/%s\b)|(%s[^>\/]*\/))>";
function Auth_OpenID_Parse()
{
$this->_link_find = sprintf("/<link\b(?!:)([^>]*)(?!<)>/%s",
$this->_re_flags);
$this->_entity_replacements = array(
'amp' => '&',
'lt' => '<',
'gt' => '>',
'quot' => '"'
);
$this->_attr_find = sprintf("/%s/%s",
$this->_attr_find,
$this->_re_flags);
$this->_removed_re = sprintf("/%s/%s",
$this->_removed_re,
$this->_re_flags);
$this->_ent_replace =
sprintf("&(%s);", implode("|",
$this->_entity_replacements));
}
/**
* Returns a regular expression that will match a given tag in an
* SGML string.
*/
function tagMatcher($tag_name, $close_tags = null)
{
$expr = $this->_tag_expr;
if ($close_tags) {
$options = implode("|", array_merge(array($tag_name), $close_tags));
$closer = sprintf("(?:%s)", $options);
} else {
$closer = $tag_name;
}
$expr = sprintf($expr, $tag_name, $closer);
return sprintf("/%s/%s", $expr, $this->_re_flags);
}
function openTag($tag_name)
{
$expr = sprintf($this->_open_tag_expr, $tag_name);
return sprintf("/%s/%s", $expr, $this->_re_flags);
}
function closeTag($tag_name)
{
$expr = sprintf($this->_close_tag_expr, $tag_name, $tag_name);
return sprintf("/%s/%s", $expr, $this->_re_flags);
}
function htmlBegin($s)
{
$matches = array();
$result = preg_match($this->openTag('html'), $s,
$matches, PREG_OFFSET_CAPTURE);
if ($result === false || !$matches) {
return false;
}
// Return the offset of the first match.
return $matches[0][1];
}
function htmlEnd($s)
{
$matches = array();
$result = preg_match($this->closeTag('html'), $s,
$matches, PREG_OFFSET_CAPTURE);
if ($result === false || !$matches) {
return false;
}
// Return the offset of the first match.
return $matches[count($matches) - 1][1];
}
function headFind()
{
return $this->tagMatcher('head', array('body', 'html'));
}
function replaceEntities($str)
{
foreach ($this->_entity_replacements as $old => $new) {
$str = preg_replace(sprintf("/&%s;/", $old), $new, $str);
}
return $str;
}
function removeQuotes($str)
{
$matches = array();
$double = '/^"(.*)"$/';
$single = "/^\'(.*)\'$/";
if (preg_match($double, $str, $matches)) {
return $matches[1];
} else if (preg_match($single, $str, $matches)) {
return $matches[1];
} else {
return $str;
}
}
/**
* Find all link tags in a string representing a HTML document and
* return a list of their attributes.
*
* @param string $html The text to parse
* @return array $list An array of arrays of attributes, one for each
* link tag
*/
function parseLinkAttrs($html)
{
$stripped = preg_replace($this->_removed_re,
"",
$html);
$html_begin = $this->htmlBegin($stripped);
$html_end = $this->htmlEnd($stripped);
if ($html_begin === false) {
return array();
}
if ($html_end === false) {
$html_end = strlen($stripped);
}
$stripped = substr($stripped, $html_begin,
$html_end - $html_begin);
// Try to find the <HEAD> tag.
$head_re = $this->headFind();
$head_matches = array();
if (!preg_match($head_re, $stripped, $head_matches)) {
return array();
}
$link_data = array();
$link_matches = array();
if (!preg_match_all($this->_link_find, $head_matches[0],
$link_matches)) {
return array();
}
foreach ($link_matches[0] as $link) {
$attr_matches = array();
preg_match_all($this->_attr_find, $link, $attr_matches);
$link_attrs = array();
foreach ($attr_matches[0] as $index => $full_match) {
$name = $attr_matches[1][$index];
$value = $this->replaceEntities(
$this->removeQuotes($attr_matches[2][$index]));
$link_attrs[strtolower($name)] = $value;
}
$link_data[] = $link_attrs;
}
return $link_data;
}
function relMatches($rel_attr, $target_rel)
{
// Does this target_rel appear in the rel_str?
// XXX: TESTME
$rels = preg_split("/\s+/", trim($rel_attr));
foreach ($rels as $rel) {
$rel = strtolower($rel);
if ($rel == $target_rel) {
return 1;
}
}
return 0;
}
function linkHasRel($link_attrs, $target_rel)
{
// Does this link have target_rel as a relationship?
// XXX: TESTME
$rel_attr = Auth_OpeniD::arrayGet($link_attrs, 'rel', null);
return ($rel_attr && $this->relMatches($rel_attr,
$target_rel));
}
function findLinksRel($link_attrs_list, $target_rel)
{
// Filter the list of link attributes on whether it has
// target_rel as a relationship.
// XXX: TESTME
$result = array();
foreach ($link_attrs_list as $attr) {
if ($this->linkHasRel($attr, $target_rel)) {
$result[] = $attr;
}
}
return $result;
}
function findFirstHref($link_attrs_list, $target_rel)
{
// Return the value of the href attribute for the first link
// tag in the list that has target_rel as a relationship.
// XXX: TESTME
$matches = $this->findLinksRel($link_attrs_list,
$target_rel);
if (!$matches) {
return null;
}
$first = $matches[0];
return Auth_OpenID::arrayGet($first, 'href', null);
}
}
function Auth_OpenID_legacy_discover($html_text, $server_rel,
$delegate_rel)
{
$p = new Auth_OpenID_Parse();
$link_attrs = $p->parseLinkAttrs($html_text);
$server_url = $p->findFirstHref($link_attrs,
$server_rel);
if ($server_url === null) {
return false;
} else {
$delegate_url = $p->findFirstHref($link_attrs,
$delegate_rel);
return array($delegate_url, $server_url);
}
}
?>