Send patches - preferably formatted by git format-patch - to patches at archlinux32 dot org.
summaryrefslogtreecommitdiff
path: root/vendor/ezyang/htmlpurifier/library/HTMLPurifier/URI.php
blob: 9c5be39d188a42a46cd9db74cd9db21e5cf4d6a7 (plain)
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
<?php

/**
 * HTML Purifier's internal representation of a URI.
 * @note
 *      Internal data-structures are completely escaped. If the data needs
 *      to be used in a non-URI context (which is very unlikely), be sure
 *      to decode it first. The URI may not necessarily be well-formed until
 *      validate() is called.
 */
class HTMLPurifier_URI
{
    /**
     * @type string
     */
    public $scheme;

    /**
     * @type string
     */
    public $userinfo;

    /**
     * @type string
     */
    public $host;

    /**
     * @type int
     */
    public $port;

    /**
     * @type string
     */
    public $path;

    /**
     * @type string
     */
    public $query;

    /**
     * @type string
     */
    public $fragment;

    /**
     * @param string $scheme
     * @param string $userinfo
     * @param string $host
     * @param int $port
     * @param string $path
     * @param string $query
     * @param string $fragment
     * @note Automatically normalizes scheme and port
     */
    public function __construct($scheme, $userinfo, $host, $port, $path, $query, $fragment)
    {
        $this->scheme = is_null($scheme) || ctype_lower($scheme) ? $scheme : strtolower($scheme);
        $this->userinfo = $userinfo;
        $this->host = $host;
        $this->port = is_null($port) ? $port : (int)$port;
        $this->path = $path;
        $this->query = $query;
        $this->fragment = $fragment;
    }

    /**
     * Retrieves a scheme object corresponding to the URI's scheme/default
     * @param HTMLPurifier_Config $config
     * @param HTMLPurifier_Context $context
     * @return HTMLPurifier_URIScheme Scheme object appropriate for validating this URI
     */
    public function getSchemeObj($config, $context)
    {
        $registry = HTMLPurifier_URISchemeRegistry::instance();
        if ($this->scheme !== null) {
            $scheme_obj = $registry->getScheme($this->scheme, $config, $context);
            if (!$scheme_obj) {
                return false;
            } // invalid scheme, clean it out
        } else {
            // no scheme: retrieve the default one
            $def = $config->getDefinition('URI');
            $scheme_obj = $def->getDefaultScheme($config, $context);
            if (!$scheme_obj) {
                if ($def->defaultScheme !== null) {
                    // something funky happened to the default scheme object
                    trigger_error(
                        'Default scheme object "' . $def->defaultScheme . '" was not readable',
                        E_USER_WARNING
                    );
                } // suppress error if it's null
                return false;
            }
        }
        return $scheme_obj;
    }

    /**
     * Generic validation method applicable for all schemes. May modify
     * this URI in order to get it into a compliant form.
     * @param HTMLPurifier_Config $config
     * @param HTMLPurifier_Context $context
     * @return bool True if validation/filtering succeeds, false if failure
     */
    public function validate($config, $context)
    {
        // ABNF definitions from RFC 3986
        $chars_sub_delims = '!$&\'()*+,;=';
        $chars_gen_delims = ':/?#[]@';
        $chars_pchar = $chars_sub_delims . ':@';

        // validate host
        if (!is_null($this->host)) {
            $host_def = new HTMLPurifier_AttrDef_URI_Host();
            $this->host = $host_def->validate($this->host, $config, $context);
            if ($this->host === false) {
                $this->host = null;
            }
        }

        // validate scheme
        // NOTE: It's not appropriate to check whether or not this
        // scheme is in our registry, since a URIFilter may convert a
        // URI that we don't allow into one we do.  So instead, we just
        // check if the scheme can be dropped because there is no host
        // and it is our default scheme.
        if (!is_null($this->scheme) && is_null($this->host) || $this->host === '') {
            // support for relative paths is pretty abysmal when the
            // scheme is present, so axe it when possible
            $def = $config->getDefinition('URI');
            if ($def->defaultScheme === $this->scheme) {
                $this->scheme = null;
            }
        }

        // validate username
        if (!is_null($this->userinfo)) {
            $encoder = new HTMLPurifier_PercentEncoder($chars_sub_delims . ':');
            $this->userinfo = $encoder->encode($this->userinfo);
        }

        // validate port
        if (!is_null($this->port)) {
            if ($this->port < 1 || $this->port > 65535) {
                $this->port = null;
            }
        }

        // validate path
        $segments_encoder = new HTMLPurifier_PercentEncoder($chars_pchar . '/');
        if (!is_null($this->host)) { // this catches $this->host === ''
            // path-abempty (hier and relative)
            // http://www.example.com/my/path
            // //www.example.com/my/path (looks odd, but works, and
            //                            recognized by most browsers)
            // (this set is valid or invalid on a scheme by scheme
            // basis, so we'll deal with it later)
            // file:///my/path
            // ///my/path
            $this->path = $segments_encoder->encode($this->path);
        } elseif ($this->path !== '') {
            if ($this->path[0] === '/') {
                // path-absolute (hier and relative)
                // http:/my/path
                // /my/path
                if (strlen($this->path) >= 2 && $this->path[1] === '/') {
                    // This could happen if both the host gets stripped
                    // out
                    // http://my/path
                    // //my/path
                    $this->path = '';
                } else {
                    $this->path = $segments_encoder->encode($this->path);
                }
            } elseif (!is_null($this->scheme)) {
                // path-rootless (hier)
                // http:my/path
                // Short circuit evaluation means we don't need to check nz
                $this->path = $segments_encoder->encode($this->path);
            } else {
                // path-noscheme (relative)
                // my/path
                // (once again, not checking nz)
                $segment_nc_encoder = new HTMLPurifier_PercentEncoder($chars_sub_delims . '@');
                $c = strpos($this->path, '/');
                if ($c !== false) {
                    $this->path =
                        $segment_nc_encoder->encode(substr($this->path, 0, $c)) .
                        $segments_encoder->encode(substr($this->path, $c));
                } else {
                    $this->path = $segment_nc_encoder->encode($this->path);
                }
            }
        } else {
            // path-empty (hier and relative)
            $this->path = ''; // just to be safe
        }

        // qf = query and fragment
        $qf_encoder = new HTMLPurifier_PercentEncoder($chars_pchar . '/?');

        if (!is_null($this->query)) {
            $this->query = $qf_encoder->encode($this->query);
        }

        if (!is_null($this->fragment)) {
            $this->fragment = $qf_encoder->encode($this->fragment);
        }
        return true;
    }

    /**
     * Convert URI back to string
     * @return string URI appropriate for output
     */
    public function toString()
    {
        // reconstruct authority
        $authority = null;
        // there is a rendering difference between a null authority
        // (http:foo-bar) and an empty string authority
        // (http:///foo-bar).
        if (!is_null($this->host)) {
            $authority = '';
            if (!is_null($this->userinfo)) {
                $authority .= $this->userinfo . '@';
            }
            $authority .= $this->host;
            if (!is_null($this->port)) {
                $authority .= ':' . $this->port;
            }
        }

        // Reconstruct the result
        // One might wonder about parsing quirks from browsers after
        // this reconstruction.  Unfortunately, parsing behavior depends
        // on what *scheme* was employed (file:///foo is handled *very*
        // differently than http:///foo), so unfortunately we have to
        // defer to the schemes to do the right thing.
        $result = '';
        if (!is_null($this->scheme)) {
            $result .= $this->scheme . ':';
        }
        if (!is_null($authority)) {
            $result .= '//' . $authority;
        }
        $result .= $this->path;
        if (!is_null($this->query)) {
            $result .= '?' . $this->query;
        }
        if (!is_null($this->fragment)) {
            $result .= '#' . $this->fragment;
        }

        return $result;
    }

    /**
     * Returns true if this URL might be considered a 'local' URL given
     * the current context.  This is true when the host is null, or
     * when it matches the host supplied to the configuration.
     *
     * Note that this does not do any scheme checking, so it is mostly
     * only appropriate for metadata that doesn't care about protocol
     * security.  isBenign is probably what you actually want.
     * @param HTMLPurifier_Config $config
     * @param HTMLPurifier_Context $context
     * @return bool
     */
    public function isLocal($config, $context)
    {
        if ($this->host === null) {
            return true;
        }
        $uri_def = $config->getDefinition('URI');
        if ($uri_def->host === $this->host) {
            return true;
        }
        return false;
    }

    /**
     * Returns true if this URL should be considered a 'benign' URL,
     * that is:
     *
     *      - It is a local URL (isLocal), and
     *      - It has a equal or better level of security
     * @param HTMLPurifier_Config $config
     * @param HTMLPurifier_Context $context
     * @return bool
     */
    public function isBenign($config, $context)
    {
        if (!$this->isLocal($config, $context)) {
            return false;
        }

        $scheme_obj = $this->getSchemeObj($config, $context);
        if (!$scheme_obj) {
            return false;
        } // conservative approach

        $current_scheme_obj = $config->getDefinition('URI')->getDefaultScheme($config, $context);
        if ($current_scheme_obj->secure) {
            if (!$scheme_obj->secure) {
                return false;
            }
        }
        return true;
    }
}

// vim: et sw=4 sts=4