688cf87637f4c94c985456f035e4a55881b10158
[squirrelmail.git] / functions / mime.php
1 <?php
2
3 /**
4 * mime.php
5 *
6 * This contains the functions necessary to detect and decode MIME
7 * messages.
8 *
9 * @copyright 1999-2019 The SquirrelMail Project Team
10 * @license http://opensource.org/licenses/gpl-license.php GNU Public License
11 * @version $Id$
12 * @package squirrelmail
13 */
14
15 /**
16 * dependency information
17 functions dependency
18 mime_structure
19 class/mime/Message.class.php
20 Message::parseStructure
21 functions/page_header.php
22 displayPageHeader
23 functions/display_messages.php
24 plain_error_message
25 mime_fetch_body
26 functions/imap_general.php
27 sqimap_run_command
28 mime_print_body_lines
29
30
31
32 functions/imap.php
33 functions/attachment_common.php
34 functions/display_messages.php
35
36 magicHtml => url_parser
37 translateText => url_parser
38
39 */
40
41
42 /* -------------------------------------------------------------------------- */
43 /* MIME DECODING */
44 /* -------------------------------------------------------------------------- */
45
46 /**
47 * Get the MIME structure
48 *
49 * This function gets the structure of a message and stores it in the "message" class.
50 * It will return this object for use with all relevant header information and
51 * fully parsed into the standard "message" object format.
52 */
53 function mime_structure ($bodystructure, $flags=array()) {
54
55 /* Isolate the body structure and remove beginning and end parenthesis. */
56 $read = trim(substr ($bodystructure, strpos(strtolower($bodystructure), 'bodystructure') + 13));
57 $read = trim(substr ($read, 0, -1));
58 $i = 0;
59 $msg = Message::parseStructure($read,$i);
60
61 if (!is_object($msg)) {
62 global $color, $mailbox;
63 displayPageHeader( $color, $mailbox );
64 $errormessage = _("SquirrelMail could not decode the bodystructure of the message");
65 $errormessage .= '<br />'._("The bodystructure provided by your IMAP server:").'<br /><br />';
66 $errormessage .= '<pre>' . sm_encode_html_special_chars($read) . '</pre>';
67 plain_error_message( $errormessage );
68 echo '</body></html>';
69 exit;
70 }
71 if (count($flags)) {
72 foreach ($flags as $flag) {
73 //FIXME: please document why it is we have to check the first char of the flag but we then go ahead and do a full string comparison anyway. Is this a speed enhancement? If not, let's keep it simple and just compare the full string and forget the switch block.
74 $char = strtoupper($flag{1});
75 switch ($char) {
76 case 'S':
77 if (strtolower($flag) == '\\seen') {
78 $msg->is_seen = true;
79 }
80 break;
81 case 'A':
82 if (strtolower($flag) == '\\answered') {
83 $msg->is_answered = true;
84 }
85 break;
86 case 'D':
87 if (strtolower($flag) == '\\deleted') {
88 $msg->is_deleted = true;
89 }
90 break;
91 case 'F':
92 if (strtolower($flag) == '\\flagged') {
93 $msg->is_flagged = true;
94 }
95 else if (strtolower($flag) == '$forwarded') {
96 $msg->is_forwarded = true;
97 }
98 break;
99 case 'M':
100 if (strtolower($flag) == '$mdnsent') {
101 $msg->is_mdnsent = true;
102 }
103 break;
104 default:
105 break;
106 }
107 }
108 }
109 // listEntities($msg);
110 return $msg;
111 }
112
113
114
115 /* This starts the parsing of a particular structure. It is called recursively,
116 * so it can be passed different structures. It returns an object of type
117 * $message.
118 * First, it checks to see if it is a multipart message. If it is, then it
119 * handles that as it sees is necessary. If it is just a regular entity,
120 * then it parses it and adds the necessary header information (by calling out
121 * to mime_get_elements()
122 */
123
124 function mime_fetch_body($imap_stream, $id, $ent_id=1, $fetch_size=0) {
125 /* Do a bit of error correction. If we couldn't find the entity id, just guess
126 * that it is the first one. That is usually the case anyway.
127 */
128
129 if (!$ent_id) {
130 $cmd = "FETCH $id BODY[]";
131 } else {
132 $cmd = "FETCH $id BODY[$ent_id]";
133 }
134
135 if ($fetch_size!=0) $cmd .= "<0.$fetch_size>";
136
137 $data = sqimap_run_command ($imap_stream, $cmd, true, $response, $message, TRUE);
138 do {
139 $topline = trim(array_shift($data));
140 } while($topline && ($topline[0] == '*') && !preg_match('/\* [0-9]+ FETCH .*BODY.*/i', $topline)) ;
141 // Matching with "BODY" above is difficult: in most cases "FETCH \(BODY" would work
142 // but some servers may put other things in the same result, perhaps something such
143 // as "* 23 FETCH (FLAGS (\Seen) BODY[1] {174}". There is some small chance that
144 // if the character sequence "BODY" appears in a response where it isn't actually
145 // a FETCH response data item name, the current regex will break things. The better
146 // way to do this would be to parse the response correctly and not use a regex.
147
148 $wholemessage = implode('', $data);
149 if (preg_match('/\{([^\}]*)\}/', $topline, $regs)) {
150 $ret = substr($wholemessage, 0, $regs[1]);
151 /* There is some information in the content info header that could be important
152 * in order to parse html messages. Let's get them here.
153 */
154 // if ($ret{0} == '<') {
155 // $data = sqimap_run_command ($imap_stream, "FETCH $id BODY[$ent_id.MIME]", true, $response, $message, TRUE);
156 // }
157 } else if (preg_match('/"([^"]*)"/', $topline, $regs)) {
158 $ret = $regs[1];
159 } else if ((stristr($topline, 'nil') !== false) && (empty($wholemessage))) {
160 $ret = $wholemessage;
161 } else {
162 global $where, $what, $mailbox, $passed_id, $startMessage;
163 $par = 'mailbox=' . urlencode($mailbox) . '&amp;passed_id=' . $passed_id;
164 if (isset($where) && isset($what)) {
165 $par .= '&amp;where=' . urlencode($where) . '&amp;what=' . urlencode($what);
166 } else {
167 $par .= '&amp;startMessage=' . $startMessage . '&amp;show_more=0';
168 }
169 $par .= '&amp;response=' . urlencode($response) .
170 '&amp;message=' . urlencode($message) .
171 '&amp;topline=' . urlencode($topline);
172
173 echo '<tt><br />' .
174 '<table width="80%"><tr>' .
175 '<tr><td colspan="2">' .
176 _("Body retrieval error. The reason for this is most probably that the message is malformed.") .
177 '</td></tr>' .
178 '<tr><td><b>' . _("Command:") . "</td><td>$cmd</td></tr>" .
179 '<tr><td><b>' . _("Response:") . "</td><td>$response</td></tr>" .
180 '<tr><td><b>' . _("Message:") . "</td><td>$message</td></tr>" .
181 '<tr><td><b>' . _("FETCH line:") . "</td><td>$topline</td></tr>" .
182 "</table><br /></tt></font><hr />";
183
184 $data = sqimap_run_command ($imap_stream, "FETCH $passed_id BODY[]", true, $response, $message, TRUE);
185 array_shift($data);
186 $wholemessage = implode('', $data);
187
188 $ret = $wholemessage;
189 }
190 return $ret;
191 }
192
193 function mime_print_body_lines ($imap_stream, $id, $ent_id=1, $encoding, $rStream='php://stdout', $force_crlf='') {
194
195 /* Don't kill the connection if the browser is over a dialup
196 * and it would take over 30 seconds to download it.
197 * Don't call set_time_limit in safe mode.
198 */
199
200 if (!ini_get('safe_mode')) {
201 set_time_limit(0);
202 }
203 /* in case of base64 encoded attachments, do not buffer them.
204 Instead, echo the decoded attachment directly to screen */
205 if (strtolower($encoding) == 'base64') {
206 if (!$ent_id) {
207 $query = "FETCH $id BODY[]";
208 } else {
209 $query = "FETCH $id BODY[$ent_id]";
210 }
211 sqimap_run_command($imap_stream,$query,true,$response,$message,TRUE,'sqimap_base64_decode',$rStream,true);
212 } else {
213 $body = mime_fetch_body ($imap_stream, $id, $ent_id);
214 if (is_resource($rStream)) {
215 fputs($rStream,decodeBody($body, $encoding, $force_crlf));
216 } else {
217 echo decodeBody($body, $encoding, $force_crlf);
218 }
219 }
220
221 /*
222 TODO, use the same method for quoted printable.
223 However, I assume that quoted printable attachments aren't that large
224 so the performancegain / memory usage drop will be minimal.
225 If we decide to add that then we need to adapt sqimap_fread because
226 we need to split te result on \n and fread doesn't stop at \n. That
227 means we also should provide $results from sqimap_fread (by ref) to
228 te function and set $no_return to false. The $filter function for
229 quoted printable should handle unsetting of $results.
230 */
231 /*
232 TODO 2: find out how we write to the output stream php://stdout. fwrite
233 doesn't work because 'php://stdout isn't a stream.
234 */
235
236 return;
237 }
238
239 /* -[ END MIME DECODING ]----------------------------------------------------------- */
240
241 /* This is here for debugging purposes. It will print out a list
242 * of all the entity IDs that are in the $message object.
243 */
244 function listEntities ($message) {
245 if ($message) {
246 echo "<tt>" . $message->entity_id . ' : ' . $message->type0 . '/' . $message->type1 . ' parent = '. $message->parent->entity_id. '<br />';
247 for ($i = 0; isset($message->entities[$i]); $i++) {
248 echo "$i : ";
249 $msg = listEntities($message->entities[$i]);
250
251 if ($msg) {
252 echo "return: ";
253 return $msg;
254 }
255 }
256 }
257 }
258
259 function getPriorityStr($priority) {
260 $priority_level = substr($priority,0,1);
261
262 switch($priority_level) {
263 /* Check for a higher then normal priority. */
264 case '1':
265 case '2':
266 $priority_string = _("High");
267 break;
268
269 /* Check for a lower then normal priority. */
270 case '4':
271 case '5':
272 $priority_string = _("Low");
273 break;
274
275 /* Check for a normal priority. */
276 case '3':
277 default:
278 $priority_level = '3';
279 $priority_string = _("Normal");
280 break;
281
282 }
283 return $priority_string;
284 }
285
286 /* returns a $message object for a particular entity id */
287 function getEntity ($message, $ent_id) {
288 return $message->getEntity($ent_id);
289 }
290
291 /* translateText
292 * Extracted from strings.php 23/03/2002
293 */
294
295 function translateText(&$body, $wrap_at, $charset) {
296 global $where, $what; /* from searching */
297 global $color; /* color theme */
298
299 // require_once(SM_PATH . 'functions/url_parser.php');
300
301 $body_ary = explode("\n", $body);
302 for ($i=0; $i < count($body_ary); $i++) {
303 $line = rtrim($body_ary[$i],"\r");
304
305 if (strlen($line) - 2 >= $wrap_at) {
306 sqWordWrap($line, $wrap_at, $charset);
307 }
308 $line = charset_decode($charset, $line);
309 $line = str_replace("\t", ' ', $line);
310
311 parseUrl ($line);
312
313 $quotes = 0;
314 $pos = 0;
315 $j = strlen($line);
316
317 while ($pos < $j) {
318 if ($line[$pos] == ' ') {
319 $pos++;
320 } else if (strpos($line, '&gt;', $pos) === $pos) {
321 $pos += 4;
322 $quotes++;
323 } else {
324 break;
325 }
326 }
327
328 if ($quotes % 2) {
329 $line = '<span class="quote1">' . $line . '</span>';
330 } elseif ($quotes) {
331 $line = '<span class="quote2">' . $line . '</span>';
332 }
333
334 $body_ary[$i] = $line;
335 }
336 $body = '<pre>' . implode("\n", $body_ary) . '</pre>';
337 }
338
339 /**
340 * This returns a parsed string called $body. That string can then
341 * be displayed as the actual message in the HTML. It contains
342 * everything needed, including HTML Tags, Attachments at the
343 * bottom, etc.
344 *
345 * Since 1.2.0 function uses message_body hook.
346 * Till 1.3.0 function included output of formatAttachments().
347 *
348 * @param resource $imap_stream imap connection resource
349 * @param object $message squirrelmail message object
350 * @param array $color squirrelmail color theme array
351 * @param integer $wrap_at number of characters per line
352 * @param string $ent_num (since 1.3.0) message part id
353 * @param integer $id (since 1.3.0) message id
354 * @param string $mailbox (since 1.3.0) imap folder name
355 * @return string html formated message text
356 */
357 function formatBody($imap_stream, $message, $color, $wrap_at, $ent_num, $id, $mailbox='INBOX') {
358 /* This if statement checks for the entity to show as the
359 * primary message. To add more of them, just put them in the
360 * order that is their priority.
361 */
362 global $startMessage, $languages, $squirrelmail_language,
363 $show_html_default, $sort, $has_unsafe_images, $passed_ent_id,
364 $use_iframe, $iframe_height, $download_and_unsafe_link,
365 $download_href, $unsafe_image_toggle_href, $unsafe_image_toggle_text,
366 $oTemplate, $nbsp;
367
368 // workaround for not updated config.php
369 if (! isset($use_iframe)) $use_iframe = false;
370
371 // If there's no "view_unsafe_images" variable in the URL, turn unsafe
372 // images off by default.
373 sqgetGlobalVar('view_unsafe_images', $view_unsafe_images, SQ_GET, FALSE);
374
375 $body = '';
376 $urlmailbox = urlencode($mailbox);
377 $body_message = getEntity($message, $ent_num);
378 if (($body_message->header->type0 == 'text') ||
379 ($body_message->header->type0 == 'rfc822')) {
380 $body = mime_fetch_body ($imap_stream, $id, $ent_num);
381 $body = decodeBody($body, $body_message->header->encoding);
382
383 if (isset($languages[$squirrelmail_language]['XTRA_CODE']) &&
384 function_exists($languages[$squirrelmail_language]['XTRA_CODE'] . '_decode')) {
385 if (mb_detect_encoding($body) != 'ASCII') {
386 $body = call_user_func($languages[$squirrelmail_language]['XTRA_CODE'] . '_decode',$body);
387 }
388 }
389
390 /* As of 1.5.2, $body is passed (and modified) by reference */
391 do_hook('message_body', $body);
392
393 /* If there are other types that shouldn't be formatted, add
394 * them here.
395 */
396
397 if ($body_message->header->type1 == 'html') {
398 if ($show_html_default <> 1) {
399 $entity_conv = array('&nbsp;' => ' ',
400 '<p>' => "\n",
401 '<P>' => "\n",
402 '<br>' => "\n",
403 '<BR>' => "\n",
404 '<br />' => "\n",
405 '<BR />' => "\n",
406 '&gt;' => '>',
407 '&lt;' => '<');
408 $body = strtr($body, $entity_conv);
409 $body = strip_tags($body);
410 $body = trim($body);
411 translateText($body, $wrap_at,
412 $body_message->header->getParameter('charset'));
413 } elseif ($use_iframe) {
414 /**
415 * If we don't add html message between iframe tags,
416 * we must detect unsafe images and modify $has_unsafe_images.
417 */
418 $html_body = magicHTML($body, $id, $message, $mailbox);
419 // Convert character set in order to display html mails in different character set
420 $html_body = charset_decode($body_message->header->getParameter('charset'),$html_body,false,true);
421
422 // creating iframe url
423 $iframeurl=sqm_baseuri().'src/view_html.php?'
424 . 'mailbox=' . $urlmailbox
425 . '&amp;passed_id=' . $id
426 . '&amp;ent_id=' . $ent_num
427 . '&amp;view_unsafe_images=' . (int) $view_unsafe_images;
428
429 global $oTemplate;
430 $oTemplate->assign('iframe_url', $iframeurl);
431 $oTemplate->assign('iframe_height', $iframe_height);
432 $oTemplate->assign('html_body', $html_body);
433
434 $body = $oTemplate->fetch('read_html_iframe.tpl');
435 } else {
436 // old way of html rendering
437 /**
438 * convert character set. charset_decode does not remove html special chars
439 * applied by magicHTML functions and does not sanitize them second time if
440 * fourth argument is true.
441 */
442 $charset = $body_message->header->getParameter('charset');
443 if (!empty($charset)) {
444 $body = charset_decode($charset,$body,false,true);
445 }
446 $body = magicHTML($body, $id, $message, $mailbox);
447 }
448 } else {
449 translateText($body, $wrap_at,
450 $body_message->header->getParameter('charset'));
451 }
452
453 /*
454 * Previously the links for downloading and unsafe images were printed
455 * under the mail. By putting the links in a global variable we can
456 * print it in the toolbar where it belongs. Since the original code was
457 * in this place it's left here. It might be possible to move it to some
458 * other place if that makes sense. The possibility to do so has not
459 * been evaluated yet.
460 */
461
462 // Initialize the global variable to an empty string.
463 // FIXME: To have $download_and_unsafe_link as a global variable might not be needed since the use of separate variables ($download_href, $unsafe_image_toggle_href, and $unsafe_image_toggle_text) for the templates was introduced.
464 $download_and_unsafe_link = '';
465
466 // Prepare and build a link for downloading the mail.
467 $link = 'passed_id=' . $id . '&amp;ent_id='.$ent_num.
468 '&amp;mailbox=' . $urlmailbox .'&amp;sort=' . $sort .
469 '&amp;startMessage=' . $startMessage . '&amp;show_more=0';
470 if (isset($passed_ent_id)) {
471 $link .= '&amp;passed_ent_id='.$passed_ent_id;
472 }
473 $download_href = SM_PATH . 'src/download.php?absolute_dl=true&amp;' . $link;
474
475 // Always add the link for downloading the mail as a file to the global
476 // variable.
477 $download_and_unsafe_link .= "$nbsp|$nbsp"
478 . create_hyperlink($download_href, _("Download this as a file"));
479
480 // Find out the right text to use in the link depending on the
481 // circumstances. If the unsafe images are displayed the link should
482 // hide them, if they aren't displayed the link should only appear if
483 // the mail really contains unsafe images.
484 if ($view_unsafe_images) {
485 $text = _("Hide Unsafe Images");
486 } else {
487 if (isset($has_unsafe_images) && $has_unsafe_images) {
488 $link .= '&amp;view_unsafe_images=1';
489 $text = _("View Unsafe Images");
490 } else {
491 $text = '';
492 }
493 }
494
495 // Only create a link for unsafe images if there's need for one. If so:
496 // add it to the global variable.
497 if($text != '') {
498 $unsafe_image_toggle_href = SM_PATH . 'src/read_body.php?'.$link;
499 $unsafe_image_toggle_text = $text;
500 $download_and_unsafe_link .= "$nbsp|$nbsp"
501 . create_hyperlink($unsafe_image_toggle_href, $text);
502 }
503 }
504 return $body;
505 }
506
507 /**
508 * Generate attachments array for passing to templates.
509 *
510 * @since 1.5.2
511 * @param object $message SquirrelMail message object
512 * @param array $exclude_id message parts that are not attachments.
513 * @param string $mailbox mailbox name
514 * @param integer $id message id
515 */
516 function buildAttachmentArray($message, $exclude_id, $mailbox, $id) {
517 global $where, $what, $startMessage, $color, $passed_ent_id,
518 $base_uri, $block_svg_download;
519
520 $att_ar = $message->getAttachments($exclude_id);
521 $urlMailbox = urlencode($mailbox);
522
523 $attachments = array();
524 foreach ($att_ar as $att) {
525 $ent = $att->entity_id;
526 $header = $att->header;
527 $type0 = strtolower($header->type0);
528 $type1 = strtolower($header->type1);
529 if ($block_svg_download && strpos($type1, 'svg') === 0)
530 continue;
531
532 $name = '';
533 $links = array();
534 $links['download link']['text'] = _("Download");
535 $links['download link']['href'] = $base_uri .
536 "src/download.php?absolute_dl=true&amp;passed_id=$id&amp;mailbox=$urlMailbox&amp;ent_id=$ent";
537
538 if ($type0 =='message' && $type1 == 'rfc822') {
539 $default_page = $base_uri . 'src/read_body.php';
540 $rfc822_header = $att->rfc822_header;
541 $filename = $rfc822_header->subject;
542 if (trim( $filename ) == '') {
543 $filename = 'untitled-[' . $ent . ']' ;
544 }
545 $from_o = $rfc822_header->from;
546 if (is_object($from_o)) {
547 $from_name = decodeHeader($from_o->getAddress(false));
548 } elseif (is_array($from_o) && count($from_o) && is_object($from_o[0])) {
549 // something weird happens when a digest message is opened and you return to the digest
550 // now the from object is part of an array. Probably the parseHeader call overwrites the info
551 // retrieved from the bodystructure in a different way. We need to fix this later.
552 // possible starting point, do not fetch header we already have and inspect how
553 // the rfc822_header object behaves.
554 $from_name = decodeHeader($from_o[0]->getAddress(false));
555 } else {
556 $from_name = _("Unknown sender");
557 }
558 $description = _("From").': '.$from_name;
559 } else {
560 $default_page = $base_uri . 'src/download.php';
561 $filename = $att->getFilename();
562 if ($header->description) {
563 $description = decodeHeader($header->description);
564 } else {
565 $description = '';
566 }
567 }
568
569 $display_filename = $filename;
570 if (isset($passed_ent_id)) {
571 $passed_ent_id_link = '&amp;passed_ent_id='.$passed_ent_id;
572 } else {
573 $passed_ent_id_link = '';
574 }
575 $defaultlink = $default_page . "?startMessage=$startMessage"
576 . "&amp;passed_id=$id&amp;mailbox=$urlMailbox"
577 . '&amp;ent_id='.$ent.$passed_ent_id_link;
578 if ($where && $what) {
579 $defaultlink .= '&amp;where='. urlencode($where).'&amp;what='.urlencode($what);
580 }
581 // IE does make use of mime content sniffing. Forcing a download
582 // prohibit execution of XSS inside an application/octet-stream attachment
583 if ($type0 == 'application' && $type1 == 'octet-stream') {
584 $defaultlink .= '&amp;absolute_dl=true';
585 }
586
587 /* This executes the attachment hook with a specific MIME-type.
588 * It also allows plugins to run if there's a rule for a more
589 * generic type. Finally, a hook for ALL attachment types is
590 * run as well.
591 */
592 // First remember the default link.
593 $defaultlink_orig = $defaultlink;
594
595 /* The API for this hook has changed as of 1.5.2 so that all plugin
596 arguments are passed in an array instead of each their own plugin
597 argument, and arguments are passed by reference, so instead of
598 returning any changes, changes should simply be made to the original
599 arguments themselves. */
600 $temp = array(&$links, &$startMessage, &$id, &$urlMailbox, &$ent,
601 &$defaultlink, &$display_filename, &$where, &$what);
602 do_hook("attachment $type0/$type1", $temp);
603 /* The API for this hook has changed as of 1.5.2 so that all plugin
604 arguments are passed in an array instead of each their own plugin
605 argument, and arguments are passed by reference, so instead of
606 returning any changes, changes should simply be made to the original
607 arguments themselves. */
608 $temp = array(&$links, &$startMessage, &$id, &$urlMailbox, &$ent,
609 &$defaultlink, &$display_filename, &$where, &$what);
610 // Do not let a generic plugin change the default link if a more
611 // specialized one already did it...
612 if ($defaultlink != $defaultlink_orig) {
613 $dummy = '';
614 $temp[5] = &$dummy;
615 }
616 do_hook("attachment $type0/*", $temp);
617 /* The API for this hook has changed as of 1.5.2 so that all plugin
618 arguments are passed in an array instead of each their own plugin
619 argument, and arguments are passed by reference, so instead of
620 returning any changes, changes should simply be made to the original
621 arguments themselves. */
622 $temp = array(&$links, &$startMessage, &$id, &$urlMailbox, &$ent,
623 &$defaultlink, &$display_filename, &$where, &$what);
624 // Do not let a generic plugin change the default link if a more
625 // specialized one already did it...
626 if ($defaultlink != $defaultlink_orig) {
627 $dummy = '';
628 $temp[5] = &$dummy;
629 }
630 do_hook("attachment */*", $temp);
631
632 $this_attachment = array();
633 $this_attachment['Name'] = decodeHeader($display_filename);
634 $this_attachment['Description'] = $description;
635 $this_attachment['DefaultHREF'] = $defaultlink;
636 $this_attachment['DownloadHREF'] = $links['download link']['href'];
637 $this_attachment['ViewHREF'] = isset($links['attachment_common']) ? $links['attachment_common']['href'] : '';
638 $this_attachment['Size'] = $header->size;
639 $this_attachment['ContentType'] = sm_encode_html_special_chars($type0 .'/'. $type1);
640 $this_attachment['OtherLinks'] = array();
641 foreach ($links as $val) {
642 if ($val['text']==_("Download") || $val['text'] == _("View"))
643 continue;
644 if (empty($val['text']) && empty($val['extra']))
645 continue;
646
647 $temp = array();
648 $temp['HREF'] = $val['href'];
649 $temp['Text'] = (empty($val['text']) ? '' : $val['text']) . (empty($val['extra']) ? '' : $val['extra']);
650 $this_attachment['OtherLinks'][] = $temp;
651 }
652 $attachments[] = $this_attachment;
653
654 unset($links);
655 }
656
657 return $attachments;
658 }
659
660 /**
661 * Displays attachment links and information
662 *
663 * Since 1.3.0 function is not included in formatBody() call.
664 *
665 * Since 1.0.2 uses attachment $type0/$type1 hook.
666 * Since 1.2.5 uses attachment $type0/* hook.
667 * Since 1.5.0 uses attachments_bottom hook.
668 * Since 1.5.2 uses templates and does *not* return a value.
669 *
670 * @param object $message SquirrelMail message object
671 * @param array $exclude_id message parts that are not attachments.
672 * @param string $mailbox mailbox name
673 * @param integer $id message id
674 */
675 function formatAttachments($message, $exclude_id, $mailbox, $id) {
676 global $oTemplate;
677
678 $attach = buildAttachmentArray($message, $exclude_id, $mailbox, $id);
679
680 $oTemplate->assign('attachments', $attach);
681 $oTemplate->display('read_attachments.tpl');
682 }
683
684 function sqimap_base64_decode(&$string) {
685
686 // Base64 encoded data goes in pairs of 4 bytes. To achieve on the
687 // fly decoding (to reduce memory usage) you have to check if the
688 // data has incomplete pairs
689
690 // Remove the noise in order to check if the 4 bytes pairs are complete
691 $string = str_replace(array("\r\n","\n", "\r", " "),array('','','',''),$string);
692
693 $sStringRem = '';
694 $iMod = strlen($string) % 4;
695 if ($iMod) {
696 $sStringRem = substr($string,-$iMod);
697 // Check if $sStringRem contains padding characters
698 if (substr($sStringRem,-1) != '=') {
699 $string = substr($string,0,-$iMod);
700 } else {
701 $sStringRem = '';
702 }
703 }
704 $string = base64_decode($string);
705 return $sStringRem;
706 }
707
708 /**
709 * Decodes encoded string (usually message body)
710 *
711 * This function decodes a string (usually the message body)
712 * depending on the encoding type. Currently quoted-printable
713 * and base64 encodings are supported.
714 *
715 * The decode_body hook was added to this function in 1.4.2/1.5.0.
716 * The $force_crlf parameter was added in 1.5.2.
717 *
718 * @param string $string The encoded string
719 * @param string $encoding used encoding
720 * @param string $force_crlf Whether or not to force CRLF or LF
721 * line endings (or to leave as is).
722 * If given as "LF", line endings will
723 * all be converted to LF; if "CRLF",
724 * line endings will all be converted
725 * to CRLF. If given as an empty value,
726 * the global $force_crlf_default will
727 * be consulted (it can be specified in
728 * config/config_local.php). Otherwise,
729 * any other value will cause the string
730 * to be left alone. Note that this will
731 * be overridden to "LF" if not using at
732 * least PHP version 4.3.0. (OPTIONAL;
733 * default is empty - consult global
734 * default value)
735 *
736 * @return string The decoded string
737 *
738 * @since 1.0
739 *
740 */
741 function decodeBody($string, $encoding, $force_crlf='') {
742
743 global $force_crlf_default;
744 if (empty($force_crlf)) $force_crlf = $force_crlf_default;
745 $force_crlf = strtoupper($force_crlf);
746
747 // must force line endings to LF due to broken
748 // quoted_printable_decode() in PHP versions
749 // before 4.3.0 (see below)
750 //
751 if (!check_php_version(4, 3, 0) || $force_crlf == 'LF')
752 $string = str_replace("\r\n", "\n", $string);
753 else if ($force_crlf == 'CRLF')
754 $string = str_replace("\n", "\r\n", $string);
755
756 $encoding = strtolower($encoding);
757
758 $encoding_handler = do_hook('decode_body', $encoding);
759
760
761 // plugins get first shot at decoding the string
762 //
763 if (!empty($encoding_handler) && function_exists($encoding_handler)) {
764 $string = $encoding_handler('decode', $string);
765
766 } elseif ($encoding == 'quoted-printable' ||
767 $encoding == 'quoted_printable') {
768
769 // quoted_printable_decode() function is broken in older
770 // php versions. Text with \r\n decoding was fixed only
771 // in php 4.3.0. Minimal code requirement is PHP 4.0.4+
772 // and the above call to: str_replace("\r\n", "\n", $string);
773 //
774 $string = quoted_printable_decode($string);
775
776 } elseif ($encoding == 'base64') {
777 $string = base64_decode($string);
778 }
779
780 // All other encodings are returned raw.
781 return $string;
782 }
783
784 /**
785 * Decodes headers
786 *
787 * This function decodes strings that are encoded according to
788 * RFC1522 (MIME Part Two: Message Header Extensions for Non-ASCII Text).
789 * Patched by Christian Schmidt <christian@ostenfeld.dk> 23/03/2002
790 *
791 * @param string $string header string that has to be made readable
792 * @param boolean $utfencode change message in order to be readable on user's charset. defaults to true
793 * @param boolean $htmlsafe preserve spaces and sanitize html special characters. defaults to true
794 * @param boolean $decide decide if string can be utfencoded. defaults to false
795 * @return string decoded header string
796 */
797 function decodeHeader ($string, $utfencode=true,$htmlsafe=true,$decide=false) {
798 global $languages, $squirrelmail_language,$default_charset, $fix_broken_base64_encoded_messages;
799 if (is_array($string)) {
800 $string = implode("\n", $string);
801 }
802
803 if (isset($languages[$squirrelmail_language]['XTRA_CODE']) &&
804 function_exists($languages[$squirrelmail_language]['XTRA_CODE'] . '_decodeheader')) {
805 $string = call_user_func($languages[$squirrelmail_language]['XTRA_CODE'] . '_decodeheader', $string);
806 // Do we need to return at this point?
807 // return $string;
808 }
809 $i = 0;
810 $iLastMatch = -2;
811 $encoded = true;
812
813 // FIXME: spaces are allowed inside quoted-printable encoding, but the following line will bust up any such encoded strings
814 $aString = explode(' ',$string);
815 $ret = '';
816 foreach ($aString as $chunk) {
817 if ($encoded && $chunk === '') {
818 continue;
819 } elseif ($chunk === '') {
820 $ret .= ' ';
821 continue;
822 }
823 $encoded = false;
824 /* if encoded words are not separated by a linear-space-white we still catch them */
825 $j = $i-1;
826
827 while ($match = preg_match('/^(.*)=\?([^?]*)\?(Q|B)\?([^?]*)\?=(.*)$/Ui',$chunk,$res)) {
828 /* if the last chunk isn't an encoded string then put back the space, otherwise don't */
829 if ($iLastMatch !== $j) {
830 if ($htmlsafe) {
831 $ret .= '&#32;';
832 } else {
833 $ret .= ' ';
834 }
835 }
836 $iLastMatch = $i;
837 $j = $i;
838 if ($htmlsafe) {
839 $ret .= sm_encode_html_special_chars($res[1]);
840 } else {
841 $ret .= $res[1];
842 }
843 $encoding = ucfirst($res[3]);
844
845 /* decide about valid decoding */
846 if ($decide && is_conversion_safe($res[2])) {
847 $utfencode=true;
848 $can_be_encoded=true;
849 } else {
850 $can_be_encoded=false;
851 }
852 switch ($encoding)
853 {
854 case 'B':
855 // fix broken base64-encoded strings (remove end = padding,
856 // change any = to + in middle of string, add padding back
857 // to the end)
858 if ($fix_broken_base64_encoded_messages) {
859 $encoded_string_minus_padding = strtr(rtrim($res[4], '='), '=', '+');
860 $res[4] = str_pad($encoded_string_minus_padding, strlen($res[4]), '=');
861 }
862 $replace = base64_decode($res[4]);
863 if ($utfencode) {
864 if ($can_be_encoded) {
865 /* convert string to different charset,
866 * if functions asks for it (usually in compose)
867 */
868 $ret .= charset_convert($res[2],$replace,$default_charset,$htmlsafe);
869 } else {
870 // convert string to html codes in order to display it
871 $ret .= charset_decode($res[2],$replace);
872 }
873 } else {
874 if ($htmlsafe) {
875 $replace = sm_encode_html_special_chars($replace);
876 }
877 $ret.= $replace;
878 }
879 break;
880 case 'Q':
881 $replace = str_replace('_', ' ', $res[4]);
882 $replace = preg_replace_callback('/=([0-9a-f]{2})/i',
883 create_function ('$matches', 'return chr(hexdec($matches[1]));'),
884 $replace);
885 if ($utfencode) {
886 if ($can_be_encoded) {
887 /* convert string to different charset,
888 * if functions asks for it (usually in compose)
889 */
890 $replace = charset_convert($res[2], $replace,$default_charset,$htmlsafe);
891 } else {
892 // convert string to html codes in order to display it
893 $replace = charset_decode($res[2], $replace);
894 }
895 } else {
896 if ($htmlsafe) {
897 $replace = sm_encode_html_special_chars($replace);
898 }
899 }
900 $ret .= $replace;
901 break;
902 default:
903 break;
904 }
905 $chunk = $res[5];
906 $encoded = true;
907 }
908 if (!$encoded) {
909 if ($htmlsafe) {
910 $ret .= '&#32;';
911 } else {
912 $ret .= ' ';
913 }
914 }
915
916 if (!$encoded && $htmlsafe) {
917 $ret .= sm_encode_html_special_chars($chunk);
918 } else {
919 $ret .= $chunk;
920 }
921 ++$i;
922 }
923 /* remove the first added space */
924 if ($ret) {
925 if ($htmlsafe) {
926 $ret = substr($ret,5);
927 } else {
928 $ret = substr($ret,1);
929 }
930 }
931
932 return $ret;
933 }
934
935 /**
936 * Encodes header
937 *
938 * Function uses XTRA_CODE _encodeheader function, if such function exists.
939 *
940 * Function uses Q encoding by default and encodes a string according to RFC
941 * 1522 for use in headers if it contains 8-bit characters or anything that
942 * looks like it should be encoded.
943 *
944 * Function switches to B encoding and encodeHeaderBase64() function, if
945 * string is 8bit and multibyte character set supported by mbstring extension
946 * is used. It can cause E_USER_NOTICE errors, if interface is used with
947 * multibyte character set unsupported by mbstring extension.
948 *
949 * @param string $string header string, that has to be encoded
950 * @return string quoted-printable encoded string
951 * @todo make $mb_charsets system wide constant
952 */
953 function encodeHeader ($string) {
954 global $default_charset, $languages, $squirrelmail_language;
955
956 if (isset($languages[$squirrelmail_language]['XTRA_CODE']) &&
957 function_exists($languages[$squirrelmail_language]['XTRA_CODE'] . '_encodeheader')) {
958 return call_user_func($languages[$squirrelmail_language]['XTRA_CODE'] . '_encodeheader', $string);
959 }
960
961 // Use B encoding for multibyte charsets
962 $mb_charsets = array('utf-8','big5','gb2313','euc-kr');
963 if (in_array($default_charset,$mb_charsets) &&
964 in_array($default_charset,sq_mb_list_encodings()) &&
965 sq_is8bit($string)) {
966 return encodeHeaderBase64($string,$default_charset);
967 } elseif (in_array($default_charset,$mb_charsets) &&
968 sq_is8bit($string) &&
969 ! in_array($default_charset,sq_mb_list_encodings())) {
970 // Add E_USER_NOTICE error here (can cause 'Cannot add header information' warning in compose.php)
971 // trigger_error('encodeHeader: Multibyte character set unsupported by mbstring extension.',E_USER_NOTICE);
972 }
973
974 // Encode only if the string contains 8-bit characters or =?
975 $j = strlen($string);
976 $max_l = 75 - strlen($default_charset) - 7;
977 $aRet = array();
978 $ret = '';
979 $iEncStart = $enc_init = false;
980 $cur_l = $iOffset = 0;
981 for($i = 0; $i < $j; ++$i) {
982 switch($string{$i})
983 {
984 case '"':
985 case '=':
986 case '<':
987 case '>':
988 case ',':
989 case '?':
990 case '_':
991 if ($iEncStart === false) {
992 $iEncStart = $i;
993 }
994 $cur_l+=3;
995 if ($cur_l > ($max_l-2)) {
996 /* if there is an stringpart that doesn't need encoding, add it */
997 $aRet[] = substr($string,$iOffset,$iEncStart-$iOffset);
998 $aRet[] = "=?$default_charset?Q?$ret?=";
999 $iOffset = $i;
1000 $cur_l = 0;
1001 $ret = '';
1002 $iEncStart = false;
1003 } else {
1004 $ret .= sprintf("=%02X",ord($string{$i}));
1005 }
1006 break;
1007 case '(':
1008 case ')':
1009 if ($iEncStart !== false) {
1010 $aRet[] = substr($string,$iOffset,$iEncStart-$iOffset);
1011 $aRet[] = "=?$default_charset?Q?$ret?=";
1012 $iOffset = $i;
1013 $cur_l = 0;
1014 $ret = '';
1015 $iEncStart = false;
1016 }
1017 break;
1018 case ' ':
1019 if ($iEncStart !== false) {
1020 $cur_l++;
1021 if ($cur_l > $max_l) {
1022 $aRet[] = substr($string,$iOffset,$iEncStart-$iOffset);
1023 $aRet[] = "=?$default_charset?Q?$ret?=";
1024 $iOffset = $i;
1025 $cur_l = 0;
1026 $ret = '';
1027 $iEncStart = false;
1028 } else {
1029 $ret .= '_';
1030 }
1031 }
1032 break;
1033 default:
1034 $k = ord($string{$i});
1035 if ($k > 126) {
1036 if ($iEncStart === false) {
1037 // do not start encoding in the middle of a string, also take the rest of the word.
1038 $sLeadString = substr($string,0,$i);
1039 $aLeadString = explode(' ',$sLeadString);
1040 $sToBeEncoded = array_pop($aLeadString);
1041 $iEncStart = $i - strlen($sToBeEncoded);
1042 $ret .= $sToBeEncoded;
1043 $cur_l += strlen($sToBeEncoded);
1044 }
1045 $cur_l += 3;
1046 /* first we add the encoded string that reached it's max size */
1047 if ($cur_l > ($max_l-2)) {
1048 $aRet[] = substr($string,$iOffset,$iEncStart-$iOffset);
1049 $aRet[] = "=?$default_charset?Q?$ret?= "; /* the next part is also encoded => separate by space */
1050 $cur_l = 3;
1051 $ret = '';
1052 $iOffset = $i;
1053 $iEncStart = $i;
1054 }
1055 $enc_init = true;
1056 $ret .= sprintf("=%02X", $k);
1057 } else {
1058 if ($iEncStart !== false) {
1059 $cur_l++;
1060 if ($cur_l > $max_l) {
1061 $aRet[] = substr($string,$iOffset,$iEncStart-$iOffset);
1062 $aRet[] = "=?$default_charset?Q?$ret?=";
1063 $iEncStart = false;
1064 $iOffset = $i;
1065 $cur_l = 0;
1066 $ret = '';
1067 } else {
1068 $ret .= $string{$i};
1069 }
1070 }
1071 }
1072 break;
1073 }
1074 }
1075
1076 if ($enc_init) {
1077 if ($iEncStart !== false) {
1078 $aRet[] = substr($string,$iOffset,$iEncStart-$iOffset);
1079 $aRet[] = "=?$default_charset?Q?$ret?=";
1080 } else {
1081 $aRet[] = substr($string,$iOffset);
1082 }
1083 $string = implode('',$aRet);
1084 }
1085 return $string;
1086 }
1087
1088 /**
1089 * Encodes string according to rfc2047 B encoding header formating rules
1090 *
1091 * It is recommended way to encode headers with character sets that store
1092 * symbols in more than one byte.
1093 *
1094 * Function requires mbstring support. If required mbstring functions are missing,
1095 * function returns false and sets E_USER_WARNING level error message.
1096 *
1097 * Minimal requirements - php 4.0.6 with mbstring extension. Please note,
1098 * that mbstring functions will generate E_WARNING errors, if unsupported
1099 * character set is used. mb_encode_mimeheader function provided by php
1100 * mbstring extension is not used in order to get better control of header
1101 * encoding.
1102 *
1103 * Used php code functions - function_exists(), trigger_error(), strlen()
1104 * (is used with charset names and base64 strings). Used php mbstring
1105 * functions - mb_strlen and mb_substr.
1106 *
1107 * Related documents: rfc 2045 (BASE64 encoding), rfc 2047 (mime header
1108 * encoding), rfc 2822 (header folding)
1109 *
1110 * @param string $string header string that must be encoded
1111 * @param string $charset character set. Must be supported by mbstring extension.
1112 * Use sq_mb_list_encodings() to detect supported charsets.
1113 * @return string string encoded according to rfc2047 B encoding formating rules
1114 * @since 1.5.1
1115 * @todo First header line can be wrapped to $iMaxLength - $HeaderFieldLength - 1
1116 * @todo Do we want to control max length of header?
1117 * @todo Do we want to control EOL (end-of-line) marker?
1118 * @todo Do we want to translate error message?
1119 */
1120 function encodeHeaderBase64($string,$charset) {
1121 /**
1122 * Check mbstring function requirements.
1123 */
1124 if (! function_exists('mb_strlen') ||
1125 ! function_exists('mb_substr')) {
1126 // set E_USER_WARNING
1127 trigger_error('encodeHeaderBase64: Required mbstring functions are missing.',E_USER_WARNING);
1128 // return false
1129 return false;
1130 }
1131
1132 // initial return array
1133 $aRet = array();
1134
1135 /**
1136 * header length = 75 symbols max (same as in encodeHeader)
1137 * remove $charset length
1138 * remove =? ? ?= (5 chars)
1139 * remove 2 more chars (\r\n ?)
1140 */
1141 $iMaxLength = 75 - strlen($charset) - 7;
1142
1143 // set first character position
1144 $iStartCharNum = 0;
1145
1146 // loop through all characters. count characters and not bytes.
1147 for ($iCharNum=1; $iCharNum<=mb_strlen($string,$charset); $iCharNum++) {
1148 // encode string from starting character to current character.
1149 $encoded_string = base64_encode(mb_substr($string,$iStartCharNum,$iCharNum-$iStartCharNum,$charset));
1150
1151 // Check encoded string length
1152 if(strlen($encoded_string)>$iMaxLength) {
1153 // if string exceeds max length, reduce number of encoded characters and add encoded string part to array
1154 $aRet[] = base64_encode(mb_substr($string,$iStartCharNum,$iCharNum-$iStartCharNum-1,$charset));
1155
1156 // set new starting character
1157 $iStartCharNum = $iCharNum-1;
1158
1159 // encode last char (in case it is last character in string)
1160 $encoded_string = base64_encode(mb_substr($string,$iStartCharNum,$iCharNum-$iStartCharNum,$charset));
1161 } // if string is shorter than max length - add next character
1162 }
1163
1164 // add last encoded string to array
1165 $aRet[] = $encoded_string;
1166
1167 // set initial return string
1168 $sRet = '';
1169
1170 // loop through encoded strings
1171 foreach($aRet as $string) {
1172 // TODO: Do we want to control EOL (end-of-line) marker
1173 if ($sRet!='') $sRet.= " ";
1174
1175 // add header tags and encoded string to return string
1176 $sRet.= '=?'.$charset.'?B?'.$string.'?=';
1177 }
1178
1179 return $sRet;
1180 }
1181
1182 /* This function trys to locate the entity_id of a specific mime element */
1183 function find_ent_id($id, $message) {
1184 for ($i = 0, $ret = ''; $ret == '' && $i < count($message->entities); $i++) {
1185 if ($message->entities[$i]->header->type0 == 'multipart') {
1186 $ret = find_ent_id($id, $message->entities[$i]);
1187 } else {
1188 if (strcasecmp($message->entities[$i]->header->id, $id) == 0) {
1189 // if (sq_check_save_extension($message->entities[$i])) {
1190 return $message->entities[$i]->entity_id;
1191 // }
1192 } elseif (!empty($message->entities[$i]->header->parameters['name'])) {
1193 /**
1194 * This is part of a fix for Outlook Express 6.x generating
1195 * cid URLs without creating content-id headers
1196 * @@JA - 20050207
1197 */
1198 if (strcasecmp($message->entities[$i]->header->parameters['name'], $id) == 0) {
1199 return $message->entities[$i]->entity_id;
1200 }
1201 }
1202 }
1203 }
1204 return $ret;
1205 }
1206
1207 function sq_check_save_extension($message) {
1208 $filename = $message->getFilename();
1209 $ext = substr($filename, strrpos($filename,'.')+1);
1210 $save_extensions = array('jpg','jpeg','gif','png','bmp');
1211 return in_array($ext, $save_extensions);
1212 }
1213
1214
1215 /**
1216 ** HTMLFILTER ROUTINES
1217 */
1218
1219 /**
1220 * This function checks attribute values for entity-encoded values
1221 * and returns them translated into 8-bit strings so we can run
1222 * checks on them.
1223 *
1224 * @param $attvalue A string to run entity check against.
1225 * @return Nothing, modifies a reference value.
1226 */
1227 function sq_defang(&$attvalue){
1228 $me = 'sq_defang';
1229 /**
1230 * Skip this if there aren't ampersands or backslashes.
1231 */
1232 if (strpos($attvalue, '&') === false
1233 && strpos($attvalue, '\\') === false){
1234 return;
1235 }
1236 $m = false;
1237 // before deent, translate the dangerous unicode characters and ... to safe values
1238 // otherwise the regular expressions do not match.
1239
1240
1241
1242 do {
1243 $m = false;
1244 $m = $m || sq_deent($attvalue, '/\&#0*(\d+);*/s');
1245 $m = $m || sq_deent($attvalue, '/\&#x0*((\d|[a-f])+);*/si', true);
1246 $m = $m || sq_deent($attvalue, '/\\\\(\d+)/s', true);
1247 } while ($m == true);
1248 $attvalue = stripslashes($attvalue);
1249 }
1250
1251 /**
1252 * Kill any tabs, newlines, or carriage returns. Our friends the
1253 * makers of the browser with 95% market value decided that it'd
1254 * be funny to make "java[tab]script" be just as good as "javascript".
1255 *
1256 * @param attvalue The attribute value before extraneous spaces removed.
1257 * @return attvalue Nothing, modifies a reference value.
1258 */
1259 function sq_unspace(&$attvalue){
1260 $me = 'sq_unspace';
1261 if (strcspn($attvalue, "\t\r\n\0 ") != strlen($attvalue)){
1262 $attvalue = str_replace(Array("\t", "\r", "\n", "\0", " "),
1263 Array('', '', '', '', ''), $attvalue);
1264 }
1265 }
1266
1267 /**
1268 * Translate all dangerous Unicode or Shift_JIS characters which are accepted by
1269 * IE as regular characters.
1270 *
1271 * @param attvalue The attribute value before dangerous characters are translated.
1272 * @return attvalue Nothing, modifies a reference value.
1273 * @author Marc Groot Koerkamp.
1274 */
1275 function sq_fixIE_idiocy(&$attvalue) {
1276 // remove NUL
1277 $attvalue = str_replace("\0", "", $attvalue);
1278 // remove comments
1279 $attvalue = preg_replace("/(\/\*.*?\*\/)/","",$attvalue);
1280
1281 // IE has the evil habit of accepting every possible value for the attribute expression.
1282 // The table below contains characters which are parsed by IE if they are used in the "expression"
1283 // attribute value.
1284 $aDangerousCharsReplacementTable = array(
1285 array('&#x029F;', '&#0671;' ,/* L UNICODE IPA Extension */
1286 '&#x0280;', '&#0640;' ,/* R UNICODE IPA Extension */
1287 '&#x0274;', '&#0628;' ,/* N UNICODE IPA Extension */
1288 '&#xFF25;', '&#65317;' ,/* Unicode FULLWIDTH LATIN CAPITAL LETTER E */
1289 '&#xFF45;', '&#65349;' ,/* Unicode FULLWIDTH LATIN SMALL LETTER E */
1290 '&#xFF38;', '&#65336;',/* Unicode FULLWIDTH LATIN CAPITAL LETTER X */
1291 '&#xFF58;', '&#65368;',/* Unicode FULLWIDTH LATIN SMALL LETTER X */
1292 '&#xFF30;', '&#65328;',/* Unicode FULLWIDTH LATIN CAPITAL LETTER P */
1293 '&#xFF50;', '&#65360;',/* Unicode FULLWIDTH LATIN SMALL LETTER P */
1294 '&#xFF32;', '&#65330;',/* Unicode FULLWIDTH LATIN CAPITAL LETTER R */
1295 '&#xFF52;', '&#65362;',/* Unicode FULLWIDTH LATIN SMALL LETTER R */
1296 '&#xFF33;', '&#65331;',/* Unicode FULLWIDTH LATIN CAPITAL LETTER S */
1297 '&#xFF53;', '&#65363;',/* Unicode FULLWIDTH LATIN SMALL LETTER S */
1298 '&#xFF29;', '&#65321;',/* Unicode FULLWIDTH LATIN CAPITAL LETTER I */
1299 '&#xFF49;', '&#65353;',/* Unicode FULLWIDTH LATIN SMALL LETTER I */
1300 '&#xFF2F;', '&#65327;',/* Unicode FULLWIDTH LATIN CAPITAL LETTER O */
1301 '&#xFF4F;', '&#65359;',/* Unicode FULLWIDTH LATIN SMALL LETTER O */
1302 '&#xFF2E;', '&#65326;',/* Unicode FULLWIDTH LATIN CAPITAL LETTER N */
1303 '&#xFF4E;', '&#65358;',/* Unicode FULLWIDTH LATIN SMALL LETTER N */
1304 '&#xFF2C;', '&#65324;',/* Unicode FULLWIDTH LATIN CAPITAL LETTER L */
1305 '&#xFF4C;', '&#65356;',/* Unicode FULLWIDTH LATIN SMALL LETTER L */
1306 '&#xFF35;', '&#65333;',/* Unicode FULLWIDTH LATIN CAPITAL LETTER U */
1307 '&#xFF55;', '&#65365;',/* Unicode FULLWIDTH LATIN SMALL LETTER U */
1308 '&#x207F;', '&#8319;' ,/* Unicode SUPERSCRIPT LATIN SMALL LETTER N */
1309 "\xEF\xBC\xA5", /* Shift JIS FULLWIDTH LATIN CAPITAL LETTER E */ // in unicode this is some Chinese char range
1310 "\xEF\xBD\x85", /* Shift JIS FULLWIDTH LATIN SMALL LETTER E */
1311 "\xEF\xBC\xB8", /* Shift JIS FULLWIDTH LATIN CAPITAL LETTER X */
1312 "\xEF\xBD\x98", /* Shift JIS FULLWIDTH LATIN SMALL LETTER X */
1313 "\xEF\xBC\xB0", /* Shift JIS FULLWIDTH LATIN CAPITAL LETTER P */
1314 "\xEF\xBD\x90", /* Shift JIS FULLWIDTH LATIN SMALL LETTER P */
1315 "\xEF\xBC\xB2", /* Shift JIS FULLWIDTH LATIN CAPITAL LETTER R */
1316 "\xEF\xBD\x92", /* Shift JIS FULLWIDTH LATIN SMALL LETTER R */
1317 "\xEF\xBC\xB3", /* Shift JIS FULLWIDTH LATIN CAPITAL LETTER S */
1318 "\xEF\xBD\x93", /* Shift JIS FULLWIDTH LATIN SMALL LETTER S */
1319 "\xEF\xBC\xA9", /* Shift JIS FULLWIDTH LATIN CAPITAL LETTER I */
1320 "\xEF\xBD\x89", /* Shift JIS FULLWIDTH LATIN SMALL LETTER I */
1321 "\xEF\xBC\xAF", /* Shift JIS FULLWIDTH LATIN CAPITAL LETTER O */
1322 "\xEF\xBD\x8F", /* Shift JIS FULLWIDTH LATIN SMALL LETTER O */
1323 "\xEF\xBC\xAE", /* Shift JIS FULLWIDTH LATIN CAPITAL LETTER N */
1324 "\xEF\xBD\x8E", /* Shift JIS FULLWIDTH LATIN SMALL LETTER N */
1325 "\xEF\xBC\xAC", /* Shift JIS FULLWIDTH LATIN CAPITAL LETTER L */
1326 "\xEF\xBD\x8C", /* Shift JIS FULLWIDTH LATIN SMALL LETTER L */
1327 "\xEF\xBC\xB5", /* Shift JIS FULLWIDTH LATIN CAPITAL LETTER U */
1328 "\xEF\xBD\x95", /* Shift JIS FULLWIDTH LATIN SMALL LETTER U */
1329 "\xE2\x81\xBF", /* Shift JIS FULLWIDTH SUPERSCRIPT N */
1330 "\xCA\x9F", /* L UNICODE IPA Extension */
1331 "\xCA\x80", /* R UNICODE IPA Extension */
1332 "\xC9\xB4"), /* N UNICODE IPA Extension */
1333 array('l', 'l', 'r','r','n','n',
1334 'E','E','e','e','X','X','x','x','P','P','p','p','R','R','r','r','S','S','s','s','I','I',
1335 'i','i','O','O','o','o','N','N','n','n','L','L','l','l','U','U','u','u','n','n',
1336 'E','e','X','x','P','p','R','r','S','s','I','i','O','o','N','n','L','l','U','u','n','l','r','n'));
1337 $attvalue = str_replace($aDangerousCharsReplacementTable[0],$aDangerousCharsReplacementTable[1],$attvalue);
1338
1339 // Escapes are useful for special characters like "{}[]()'&. In other cases they are
1340 // used for XSS.
1341 $attvalue = preg_replace("/(\\\\)([a-zA-Z]{1})/",'$2',$attvalue);
1342 }
1343
1344 /**
1345 * This function returns the final tag out of the tag name, an array
1346 * of attributes, and the type of the tag. This function is called by
1347 * sq_sanitize internally.
1348 *
1349 * @param $tagname the name of the tag.
1350 * @param $attary the array of attributes and their values
1351 * @param $tagtype The type of the tag (see in comments).
1352 * @return a string with the final tag representation.
1353 */
1354 function sq_tagprint($tagname, $attary, $tagtype){
1355 $me = 'sq_tagprint';
1356
1357 if ($tagtype == 2){
1358 $fulltag = '</' . $tagname . '>';
1359 } else {
1360 $fulltag = '<' . $tagname;
1361 if (is_array($attary) && sizeof($attary)){
1362 $atts = Array();
1363 while (list($attname, $attvalue) = each($attary)){
1364 array_push($atts, "$attname=$attvalue");
1365 }
1366 $fulltag .= ' ' . join(" ", $atts);
1367 }
1368 if ($tagtype == 3){
1369 $fulltag .= ' /';
1370 }
1371 $fulltag .= '>';
1372 }
1373 return $fulltag;
1374 }
1375
1376 /**
1377 * A small helper function to use with array_walk. Modifies a by-ref
1378 * value and makes it lowercase.
1379 *
1380 * @param $val a value passed by-ref.
1381 * @return void since it modifies a by-ref value.
1382 */
1383 function sq_casenormalize(&$val){
1384 $val = strtolower($val);
1385 }
1386
1387 /**
1388 * This function skips any whitespace from the current position within
1389 * a string and to the next non-whitespace value.
1390 *
1391 * @param $body the string
1392 * @param $offset the offset within the string where we should start
1393 * looking for the next non-whitespace character.
1394 * @return the location within the $body where the next
1395 * non-whitespace char is located.
1396 */
1397 function sq_skipspace($body, $offset){
1398 $me = 'sq_skipspace';
1399 preg_match('/^(\s*)/s', substr($body, $offset), $matches);
1400 if (!empty($matches[1])){
1401 $offset += strlen($matches[1]);
1402 }
1403 return $offset;
1404 }
1405
1406 /**
1407 * This function looks for the next character within a string. It's
1408 * really just a glorified "strpos", except it catches if failures
1409 * nicely.
1410 *
1411 * @param $body The string to look for needle in.
1412 * @param $offset Start looking from this position.
1413 * @param $needle The character/string to look for.
1414 * @return location of the next occurance of the needle, or
1415 * strlen($body) if needle wasn't found.
1416 */
1417 function sq_findnxstr($body, $offset, $needle){
1418 $me = 'sq_findnxstr';
1419 $pos = strpos($body, $needle, $offset);
1420 if ($pos === FALSE){
1421 $pos = strlen($body);
1422 }
1423 return $pos;
1424 }
1425
1426 /**
1427 * This function takes a PCRE-style regexp and tries to match it
1428 * within the string.
1429 *
1430 * @param $body The string to look for needle in.
1431 * @param $offset Start looking from here.
1432 * @param $reg A PCRE-style regex to match.
1433 * @return Returns a false if no matches found, or an array
1434 * with the following members:
1435 * - integer with the location of the match within $body
1436 * - string with whatever content between offset and the match
1437 * - string with whatever it is we matched
1438 */
1439 function sq_findnxreg($body, $offset, $reg){
1440 $me = 'sq_findnxreg';
1441 $matches = Array();
1442 $retarr = Array();
1443 preg_match("%^(.*?)($reg)%si", substr($body, $offset), $matches);
1444 if (!isset($matches{0}) || !$matches{0}){
1445 $retarr = false;
1446 } else {
1447 $retarr{0} = $offset + strlen($matches{1});
1448 $retarr{1} = $matches{1};
1449 $retarr{2} = $matches{2};
1450 }
1451 return $retarr;
1452 }
1453
1454 /**
1455 * This function looks for the next tag.
1456 *
1457 * @param $body String where to look for the next tag.
1458 * @param $offset Start looking from here.
1459 * @return false if no more tags exist in the body, or
1460 * an array with the following members:
1461 * - string with the name of the tag
1462 * - array with attributes and their values
1463 * - integer with tag type (1, 2, or 3)
1464 * - integer where the tag starts (starting "<")
1465 * - integer where the tag ends (ending ">")
1466 * first three members will be false, if the tag is invalid.
1467 */
1468 function sq_getnxtag($body, $offset){
1469 $me = 'sq_getnxtag';
1470 if ($offset > strlen($body)){
1471 return false;
1472 }
1473 $lt = sq_findnxstr($body, $offset, "<");
1474 if ($lt == strlen($body)){
1475 return false;
1476 }
1477 /**
1478 * We are here:
1479 * blah blah <tag attribute="value">
1480 * \---------^
1481 */
1482 $pos = sq_skipspace($body, $lt+1);
1483 if ($pos >= strlen($body)){
1484 return Array(false, false, false, $lt, strlen($body));
1485 }
1486 /**
1487 * There are 3 kinds of tags:
1488 * 1. Opening tag, e.g.:
1489 * <a href="blah">
1490 * 2. Closing tag, e.g.:
1491 * </a>
1492 * 3. XHTML-style content-less tag, e.g.:
1493 * <img src="blah" />
1494 */
1495 $tagtype = false;
1496 switch (substr($body, $pos, 1)){
1497 case '/':
1498 $tagtype = 2;
1499 $pos++;
1500 break;
1501 case '!':
1502 /**
1503 * A comment or an SGML declaration.
1504 */
1505 if (substr($body, $pos+1, 2) == "--"){
1506 $gt = strpos($body, "-->", $pos);
1507 if ($gt === false){
1508 $gt = strlen($body);
1509 } else {
1510 $gt += 2;
1511 }
1512 return Array(false, false, false, $lt, $gt);
1513 } else {
1514 $gt = sq_findnxstr($body, $pos, ">");
1515 return Array(false, false, false, $lt, $gt);
1516 }
1517 break;
1518 default:
1519 /**
1520 * Assume tagtype 1 for now. If it's type 3, we'll switch values
1521 * later.
1522 */
1523 $tagtype = 1;
1524 break;
1525 }
1526
1527 $tag_start = $pos;
1528 $tagname = '';
1529 /**
1530 * Look for next [\W-_], which will indicate the end of the tag name.
1531 */
1532 $regary = sq_findnxreg($body, $pos, "[^\w\-_]");
1533 if ($regary == false){
1534 return Array(false, false, false, $lt, strlen($body));
1535 }
1536 list($pos, $tagname, $match) = $regary;
1537 $tagname = strtolower($tagname);
1538
1539 /**
1540 * $match can be either of these:
1541 * '>' indicating the end of the tag entirely.
1542 * '\s' indicating the end of the tag name.
1543 * '/' indicating that this is type-3 xhtml tag.
1544 *
1545 * Whatever else we find there indicates an invalid tag.
1546 */
1547 switch ($match){
1548 case '/':
1549 /**
1550 * This is an xhtml-style tag with a closing / at the
1551 * end, like so: <img src="blah" />. Check if it's followed
1552 * by the closing bracket. If not, then this tag is invalid
1553 */
1554 if (substr($body, $pos, 2) == "/>"){
1555 $pos++;
1556 $tagtype = 3;
1557 } else {
1558 $gt = sq_findnxstr($body, $pos, ">");
1559 $retary = Array(false, false, false, $lt, $gt);
1560 return $retary;
1561 }
1562 case '>':
1563 return Array($tagname, false, $tagtype, $lt, $pos);
1564 break;
1565 default:
1566 /**
1567 * Check if it's whitespace
1568 */
1569 if (!preg_match('/\s/', $match)){
1570 /**
1571 * This is an invalid tag! Look for the next closing ">".
1572 */
1573 $gt = sq_findnxstr($body, $lt, ">");
1574 return Array(false, false, false, $lt, $gt);
1575 }
1576 break;
1577 }
1578
1579 /**
1580 * At this point we're here:
1581 * <tagname attribute='blah'>
1582 * \-------^
1583 *
1584 * At this point we loop in order to find all attributes.
1585 */
1586 $attname = '';
1587 $atttype = false;
1588 $attary = Array();
1589
1590 while ($pos <= strlen($body)){
1591 $pos = sq_skipspace($body, $pos);
1592 if ($pos == strlen($body)){
1593 /**
1594 * Non-closed tag.
1595 */
1596 return Array(false, false, false, $lt, $pos);
1597 }
1598 /**
1599 * See if we arrived at a ">" or "/>", which means that we reached
1600 * the end of the tag.
1601 */
1602 $matches = Array();
1603 if (preg_match("%^(\s*)(>|/>)%s", substr($body, $pos), $matches)) {
1604 /**
1605 * Yep. So we did.
1606 */
1607 $pos += strlen($matches{1});
1608 if ($matches{2} == "/>"){
1609 $tagtype = 3;
1610 $pos++;
1611 }
1612 return Array($tagname, $attary, $tagtype, $lt, $pos);
1613 }
1614
1615 /**
1616 * There are several types of attributes, with optional
1617 * [:space:] between members.
1618 * Type 1:
1619 * attrname[:space:]=[:space:]'CDATA'
1620 * Type 2:
1621 * attrname[:space:]=[:space:]"CDATA"
1622 * Type 3:
1623 * attr[:space:]=[:space:]CDATA
1624 * Type 4:
1625 * attrname
1626 *
1627 * We leave types 1 and 2 the same, type 3 we check for
1628 * '"' and convert to "&quot" if needed, then wrap in
1629 * double quotes. Type 4 we convert into:
1630 * attrname="yes".
1631 */
1632 $regary = sq_findnxreg($body, $pos, "[^:\w\-_]");
1633 if ($regary == false){
1634 /**
1635 * Looks like body ended before the end of tag.
1636 */
1637 return Array(false, false, false, $lt, strlen($body));
1638 }
1639 list($pos, $attname, $match) = $regary;
1640 $attname = strtolower($attname);
1641 /**
1642 * We arrived at the end of attribute name. Several things possible
1643 * here:
1644 * '>' means the end of the tag and this is attribute type 4
1645 * '/' if followed by '>' means the same thing as above
1646 * '\s' means a lot of things -- look what it's followed by.
1647 * anything else means the attribute is invalid.
1648 */
1649 switch($match){
1650 case '/':
1651 /**
1652 * This is an xhtml-style tag with a closing / at the
1653 * end, like so: <img src="blah" />. Check if it's followed
1654 * by the closing bracket. If not, then this tag is invalid
1655 */
1656 if (substr($body, $pos, 2) == "/>"){
1657 $pos++;
1658 $tagtype = 3;
1659 } else {
1660 $gt = sq_findnxstr($body, $pos, ">");
1661 $retary = Array(false, false, false, $lt, $gt);
1662 return $retary;
1663 }
1664 case '>':
1665 $attary{$attname} = '"yes"';
1666 return Array($tagname, $attary, $tagtype, $lt, $pos);
1667 break;
1668 default:
1669 /**
1670 * Skip whitespace and see what we arrive at.
1671 */
1672 $pos = sq_skipspace($body, $pos);
1673 $char = substr($body, $pos, 1);
1674 /**
1675 * Two things are valid here:
1676 * '=' means this is attribute type 1 2 or 3.
1677 * \w means this was attribute type 4.
1678 * anything else we ignore and re-loop. End of tag and
1679 * invalid stuff will be caught by our checks at the beginning
1680 * of the loop.
1681 */
1682 if ($char == "="){
1683 $pos++;
1684 $pos = sq_skipspace($body, $pos);
1685 /**
1686 * Here are 3 possibilities:
1687 * "'" attribute type 1
1688 * '"' attribute type 2
1689 * everything else is the content of tag type 3
1690 */
1691 $quot = substr($body, $pos, 1);
1692 if ($quot == "'"){
1693 $regary = sq_findnxreg($body, $pos+1, "\'");
1694 if ($regary == false){
1695 return Array(false, false, false, $lt, strlen($body));
1696 }
1697 list($pos, $attval, $match) = $regary;
1698 $pos++;
1699 $attary{$attname} = "'" . $attval . "'";
1700 } else if ($quot == '"'){
1701 $regary = sq_findnxreg($body, $pos+1, '\"');
1702 if ($regary == false){
1703 return Array(false, false, false, $lt, strlen($body));
1704 }
1705 list($pos, $attval, $match) = $regary;
1706 $pos++;
1707 $attary{$attname} = '"' . $attval . '"';
1708 } else {
1709 /**
1710 * These are hateful. Look for \s, or >.
1711 */
1712 $regary = sq_findnxreg($body, $pos, "[\s>]");
1713 if ($regary == false){
1714 return Array(false, false, false, $lt, strlen($body));
1715 }
1716 list($pos, $attval, $match) = $regary;
1717 /**
1718 * If it's ">" it will be caught at the top.
1719 */
1720 $attval = preg_replace("/\"/s", "&quot;", $attval);
1721 $attary{$attname} = '"' . $attval . '"';
1722 }
1723 } else if (preg_match("|[\w/>]|", $char)) {
1724 /**
1725 * That was attribute type 4.
1726 */
1727 $attary{$attname} = '"yes"';
1728 } else {
1729 /**
1730 * An illegal character. Find next '>' and return.
1731 */
1732 $gt = sq_findnxstr($body, $pos, ">");
1733 return Array(false, false, false, $lt, $gt);
1734 }
1735 break;
1736 }
1737 }
1738 /**
1739 * The fact that we got here indicates that the tag end was never
1740 * found. Return invalid tag indication so it gets stripped.
1741 */
1742 return Array(false, false, false, $lt, strlen($body));
1743 }
1744
1745 /**
1746 * Translates entities into literal values so they can be checked.
1747 *
1748 * @param $attvalue the by-ref value to check.
1749 * @param $regex the regular expression to check against.
1750 * @param $hex whether the entites are hexadecimal.
1751 * @return True or False depending on whether there were matches.
1752 */
1753 function sq_deent(&$attvalue, $regex, $hex=false){
1754 $me = 'sq_deent';
1755 $ret_match = false;
1756 // remove comments
1757 //$attvalue = preg_replace("/(\/\*.*\*\/)/","",$attvalue);
1758 preg_match_all($regex, $attvalue, $matches);
1759 if (is_array($matches) && sizeof($matches[0]) > 0){
1760 $repl = Array();
1761 for ($i = 0; $i < sizeof($matches[0]); $i++){
1762 $numval = $matches[1][$i];
1763 if ($hex){
1764 $numval = hexdec($numval);
1765 }
1766 $repl{$matches[0][$i]} = chr($numval);
1767 }
1768 $attvalue = strtr($attvalue, $repl);
1769 return true;
1770 } else {
1771 return false;
1772 }
1773 }
1774
1775 /**
1776 * This function runs various checks against the attributes.
1777 *
1778 * @param $tagname String with the name of the tag.
1779 * @param $attary Array with all tag attributes.
1780 * @param $rm_attnames See description for sq_sanitize
1781 * @param $bad_attvals See description for sq_sanitize
1782 * @param $add_attr_to_tag See description for sq_sanitize
1783 * @param $message message object
1784 * @param $id message id
1785 * @return Array with modified attributes.
1786 */
1787 function sq_fixatts($tagname,
1788 $attary,
1789 $rm_attnames,
1790 $bad_attvals,
1791 $add_attr_to_tag,
1792 $message,
1793 $id,
1794 $mailbox
1795 ){
1796 $me = 'sq_fixatts';
1797 while (list($attname, $attvalue) = each($attary)){
1798 /**
1799 * See if this attribute should be removed.
1800 */
1801 foreach ($rm_attnames as $matchtag=>$matchattrs){
1802 if (preg_match($matchtag, $tagname)){
1803 foreach ($matchattrs as $matchattr){
1804 if (preg_match($matchattr, $attname)){
1805 unset($attary{$attname});
1806 continue;
1807 }
1808 }
1809 }
1810 }
1811 /**
1812 * Workaround for IE quirks
1813 */
1814 sq_fixIE_idiocy($attvalue);
1815
1816 /**
1817 * Remove any backslashes, entities, and extraneous whitespace.
1818 */
1819
1820 $oldattvalue = $attvalue;
1821 sq_defang($attvalue);
1822 if ($attname == 'style' && $attvalue !== $oldattvalue) {
1823 // entities are used in the attribute value. In 99% of the cases it's there as XSS
1824 // i.e.<div style="{ left:exp&#x0280;essio&#x0274;( alert('XSS') ) }">
1825 $attvalue = "idiocy";
1826 $attary{$attname} = $attvalue;
1827 }
1828 sq_unspace($attvalue);
1829
1830 /**
1831 * Now let's run checks on the attvalues.
1832 * I don't expect anyone to comprehend this. If you do,
1833 * get in touch with me so I can drive to where you live and
1834 * shake your hand personally. :)
1835 */
1836 foreach ($bad_attvals as $matchtag=>$matchattrs){
1837 if (preg_match($matchtag, $tagname)){
1838 foreach ($matchattrs as $matchattr=>$valary){
1839 if (preg_match($matchattr, $attname)){
1840 /**
1841 * There are two arrays in valary.
1842 * First is matches.
1843 * Second one is replacements
1844 */
1845 list($valmatch, $valrepl) = $valary;
1846 $newvalue =
1847 preg_replace($valmatch, $valrepl, $attvalue);
1848 if ($newvalue != $attvalue){
1849 $attary{$attname} = $newvalue;
1850 $attvalue = $newvalue;
1851 }
1852 }
1853 }
1854 }
1855 }
1856 if ($attname == 'style') {
1857 if (preg_match('/[\0-\37\200-\377]+/',$attvalue)) {
1858 // 8bit and control characters in style attribute values can be used for XSS, remove them
1859 $attary{$attname} = '"disallowed character"';
1860 }
1861 preg_match_all("/url\s*\((.+)\)/si",$attvalue,$aMatch);
1862 if (count($aMatch)) {
1863 foreach($aMatch[1] as $sMatch) {
1864 // url value
1865 $urlvalue = $sMatch;
1866 sq_fix_url($attname, $urlvalue, $message, $id, $mailbox,"'");
1867 $attary{$attname} = str_replace($sMatch,$urlvalue,$attvalue);
1868 }
1869 }
1870 }
1871 /**
1872 * Use white list based filtering on attributes which can contain url's
1873 */
1874 else if ($attname == 'href' || $attname == 'xlink:href' || $attname == 'src'
1875 || $attname == 'poster' || $attname == 'formaction'
1876 || $attname == 'background' || $attname == 'action') {
1877 sq_fix_url($attname, $attvalue, $message, $id, $mailbox);
1878 $attary{$attname} = $attvalue;
1879 }
1880 }
1881 /**
1882 * See if we need to append any attributes to this tag.
1883 */
1884 foreach ($add_attr_to_tag as $matchtag=>$addattary){
1885 if (preg_match($matchtag, $tagname)){
1886 $attary = array_merge($attary, $addattary);
1887 }
1888 }
1889 return $attary;
1890 }
1891
1892 /**
1893 * This function filters url's
1894 *
1895 * @param $attvalue String with attribute value to filter
1896 * @param $message message object
1897 * @param $id message id
1898 * @param $mailbox mailbox
1899 * @param $sQuote quoting characters around url's
1900 */
1901 function sq_fix_url($attname, &$attvalue, $message, $id, $mailbox,$sQuote = '"') {
1902 $attvalue = trim($attvalue);
1903 if ($attvalue && ($attvalue[0] =='"'|| $attvalue[0] == "'")) {
1904 // remove the double quotes
1905 $sQuote = $attvalue[0];
1906 $attvalue = trim(substr($attvalue,1,-1));
1907 }
1908
1909 // If there's no "view_unsafe_images" variable in the URL, turn unsafe
1910 // images off by default.
1911 sqgetGlobalVar('view_unsafe_images', $view_unsafe_images, SQ_GET, FALSE);
1912
1913 global $use_transparent_security_image;
1914 if ($use_transparent_security_image) $secremoveimg = '../images/spacer.png';
1915 else $secremoveimg = '../images/' . _("sec_remove_eng.png");
1916
1917 /**
1918 * Replace empty src tags with the blank image. src is only used
1919 * for frames, images, and image inputs. Doing a replace should
1920 * not affect them working as should be, however it will stop
1921 * IE from being kicked off when src for img tags are not set
1922 */
1923 if ($attvalue == '') {
1924 $attvalue = '"' . SM_PATH . 'images/blank.png"';
1925 } else {
1926 // first, disallow 8 bit characters and control characters
1927 if (preg_match('/[\0-\37\200-\377]+/',$attvalue)) {
1928 switch ($attname) {
1929 case 'href':
1930 $attvalue = $sQuote . 'http://invalid-stuff-detected.example.com' . $sQuote;
1931 break;
1932 default:
1933 $attvalue = $sQuote . SM_PATH . 'images/blank.png'. $sQuote;
1934 break;
1935 }
1936 } else {
1937 $aUrl = parse_url($attvalue);
1938 if (isset($aUrl['scheme'])) {
1939 switch(strtolower($aUrl['scheme'])) {
1940 case 'mailto':
1941 case 'http':
1942 case 'https':
1943 case 'ftp':
1944 if ($attname != 'href') {
1945 if ($view_unsafe_images == false) {
1946 $attvalue = $sQuote . $secremoveimg . $sQuote;
1947 } else {
1948 if (isset($aUrl['path'])) {
1949
1950 // No one has been able to show that image URIs
1951 // can be exploited, so for now, no restrictions
1952 // are made at all. If this proves to be a problem,
1953 // the commented-out code below can be of help.
1954 // (One consideration is that I see nothing in this
1955 // function that specifically says that we will
1956 // only ever arrive here when inspecting an image
1957 // tag, although that does seem to be the end
1958 // result - e.g., <script src="..."> where malicious
1959 // image URIs are in fact a problem are already
1960 // filtered out elsewhere.
1961 /* ---------------------------------
1962 // validate image extension.
1963 $ext = strtolower(substr($aUrl['path'],strrpos($aUrl['path'],'.')));
1964 if (!in_array($ext,array('.jpeg','.jpg','xjpeg','.gif','.bmp','.jpe','.png','.xbm'))) {
1965 // If URI is to something other than
1966 // a regular image file, get the contents
1967 // and try to see if it is an image.
1968 // Don't use Fileinfo (finfo_file()) because
1969 // we'd need to make the admin configure the
1970 // location of the magic.mime file (FIXME: add finfo_file() support later?)
1971 //
1972 $mime_type = '';
1973 if (function_exists('mime_content_type')
1974 && ($FILE = @fopen($attvalue, 'rb', FALSE))) {
1975
1976 // fetch file
1977 //
1978 $file_contents = '';
1979 while (!feof($FILE)) {
1980 $file_contents .= fread($FILE, 8192);
1981 }
1982 fclose($FILE);
1983
1984 // store file locally
1985 //
1986 global $attachment_dir, $username;
1987 $hashed_attachment_dir = getHashedDir($username, $attachment_dir);
1988 $localfilename = GenerateRandomString(32, '', 7);
1989 $full_localfilename = "$hashed_attachment_dir/$localfilename";
1990 while (file_exists($full_localfilename)) {
1991 $localfilename = GenerateRandomString(32, '', 7);
1992 $full_localfilename = "$hashed_attachment_dir/$localfilename";
1993 }
1994 $FILE = fopen("$hashed_attachment_dir/$localfilename", 'wb');
1995 fwrite($FILE, $file_contents);
1996 fclose($FILE);
1997
1998 // get mime type and remove file
1999 //
2000 $mime_type = mime_content_type("$hashed_attachment_dir/$localfilename");
2001 unlink("$hashed_attachment_dir/$localfilename");
2002 }
2003 // debug: echo "$attvalue FILE TYPE IS $mime_type<HR>";
2004 if (substr(strtolower($mime_type), 0, 5) != 'image') {
2005 $attvalue = $sQuote . SM_PATH . 'images/blank.png'. $sQuote;
2006 }
2007 }
2008 --------------------------------- */
2009 } else {
2010 $attvalue = $sQuote . SM_PATH . 'images/blank.png'. $sQuote;
2011 }
2012 }
2013 } else {
2014 $attvalue = $sQuote . $attvalue . $sQuote;
2015 }
2016 break;
2017 case 'outbind':
2018 /**
2019 * "Hack" fix for Outlook using propriatary outbind:// protocol in img tags.
2020 * One day MS might actually make it match something useful, for now, falling
2021 * back to using cid2http, so we can grab the blank.png.
2022 */
2023 $attvalue = $sQuote . sq_cid2http($message, $id, $attvalue, $mailbox) . $sQuote;
2024 break;
2025 case 'cid':
2026 /**
2027 * Turn cid: urls into http-friendly ones.
2028 */
2029 $attvalue = $sQuote . sq_cid2http($message, $id, $attvalue, $mailbox) . $sQuote;
2030 break;
2031 default:
2032 $attvalue = $sQuote . SM_PATH . 'images/blank.png' . $sQuote;
2033 break;
2034 }
2035 } else {
2036 if (!isset($aUrl['path']) || $aUrl['path'] != $secremoveimg) {
2037 // parse_url did not lead to satisfying result
2038 $attvalue = $sQuote . SM_PATH . 'images/blank.png' . $sQuote;
2039 }
2040 }
2041 }
2042 }
2043 }
2044
2045 /**
2046 * This function edits the style definition to make them friendly and
2047 * usable in SquirrelMail.
2048 *
2049 * @param $message the message object
2050 * @param $id the message id
2051 * @param $content a string with whatever is between <style> and </style>
2052 * @param $mailbox the message mailbox
2053 * @return a string with edited content.
2054 */
2055 function sq_fixstyle($body, $pos, $message, $id, $mailbox){
2056 $me = 'sq_fixstyle';
2057 // workaround for </style> in between comments
2058 $iCurrentPos = $pos;
2059 $content = '';
2060 $sToken = '';
2061 $bSucces = false;
2062 $bEndTag = false;
2063 for ($i=$pos,$iCount=strlen($body);$i<$iCount;++$i) {
2064 $char = $body{$i};
2065 switch ($char) {
2066 case '<':
2067 $sToken = $char;
2068 break;
2069 case '/':
2070 if ($sToken == '<') {
2071 $sToken .= $char;
2072 $bEndTag = true;
2073 } else {
2074 $content .= $char;
2075 }
2076 break;
2077 case '>':
2078 if ($bEndTag) {
2079 $sToken .= $char;
2080 if (preg_match('/\<\/\s*style\s*\>/i',$sToken,$aMatch)) {
2081 $newpos = $i + 1;
2082 $bSucces = true;
2083 break 2;
2084 } else {
2085 $content .= $sToken;
2086 }
2087 $bEndTag = false;
2088 } else {
2089 $content .= $char;
2090 }
2091 break;
2092 case '!':
2093 if ($sToken == '<') {
2094 // possible comment
2095 if (isset($body{$i+2}) && substr($body,$i,3) == '!--') {
2096 $i = strpos($body,'-->',$i+3);
2097 if ($i === false) { // no end comment
2098 $i = strlen($body);
2099 }
2100 $sToken = '';
2101 }
2102 } else {
2103 $content .= $char;
2104 }
2105 break;
2106 default:
2107 if ($bEndTag) {
2108 $sToken .= $char;
2109 } else {
2110 $content .= $char;
2111 }
2112 break;
2113 }
2114 }
2115 if ($bSucces == FALSE){
2116 return array(FALSE, strlen($body));
2117 }
2118
2119
2120
2121 /**
2122 * First look for general BODY style declaration, which would be
2123 * like so:
2124 * body {background: blah-blah}
2125 * and change it to .bodyclass so we can just assign it to a <div>
2126 */
2127 // $content = preg_replace("|body(\s*\{.*?\})|si", ".bodyclass\\1", $content);
2128 // Nah, this is even better - try to preface all CSS selectors with
2129 // our <div> class ID "bodyclass" then correct generic "body" selectors
2130 // TODO: this works pretty good but breaks stuff like this:
2131 // @media print { body { font-size: 10pt; } }
2132 // but there isn't an easy way to make this regex skip @media
2133 // definitions... though lots of the ones in the wild will be
2134 // correctly handled because they tend to end with a parenthesis, like:
2135 // @media screen and (max-width:480px) { ...
2136 $content = preg_replace('/([a-z0-9._-][a-z0-9 >+~|:._-]*\s*(?:,|{.*?}))/si', '.bodyclass $1', $content);
2137 $content = str_replace('.bodyclass body', '.bodyclass', $content);
2138
2139 global $use_transparent_security_image;
2140 if ($use_transparent_security_image) $secremoveimg = '../images/spacer.png';
2141 else $secremoveimg = '../images/' . _("sec_remove_eng.png");
2142
2143 /**
2144 * Fix url('blah') declarations.
2145 */
2146 // $content = preg_replace("|url\s*\(\s*([\'\"])\s*\S+script\s*:.*?([\'\"])\s*\)|si",
2147 // "url(\\1$secremoveimg\\2)", $content);
2148
2149 // first check for 8bit sequences and disallowed control characters
2150 if (preg_match('/[\16-\37\200-\377]+/',$content)) {
2151 $content = '<!-- style block removed by html filter due to presence of 8bit characters -->';
2152 return array($content, $newpos);
2153 }
2154
2155 // IE Sucks hard. We have a special function for it.
2156 sq_fixIE_idiocy($content);
2157
2158 // remove @import line
2159 $content = preg_replace("/^\s*(@import.*)$/mi","\n<!-- @import rules forbidden -->\n",$content);
2160
2161 // translate ur\l and variations (IE parses that)
2162 // TODO check if the sq_fixIE_idiocy function already handles this.
2163 $content = preg_replace("/(\\\\)?u(\\\\)?r(\\\\)?l(\\\\)?/i", 'url', $content);
2164 preg_match_all("/url\s*\((.+)\)/si",$content,$aMatch);
2165 if (count($aMatch)) {
2166 $aValue = $aReplace = array();
2167 foreach($aMatch[1] as $sMatch) {
2168 // url value
2169 $urlvalue = $sMatch;
2170 sq_fix_url('style',$urlvalue, $message, $id, $mailbox,"'");
2171 $aValue[] = $sMatch;
2172 $aReplace[] = $urlvalue;
2173 }
2174 $content = str_replace($aValue,$aReplace,$content);
2175 }
2176
2177 /**
2178 * Remove any backslashes, entities, and extraneous whitespace.
2179 */
2180 $contentTemp = $content;
2181 sq_defang($contentTemp);
2182 sq_unspace($contentTemp);
2183
2184 /**
2185 * Fix stupid css declarations which lead to vulnerabilities
2186 * in IE.
2187 *
2188 * Also remove "position" attribute, as it can easily be set
2189 * to "fixed" or "absolute" with "left" and "top" attributes
2190 * of zero, taking over the whole content frame. It can also
2191 * be set to relative and move itself anywhere it wants to,
2192 * displaying content in areas it shouldn't be allowed to touch.
2193 */
2194 $match = Array('/\/\*.*\*\//', // removes /* blah blah */
2195 '/expression/i',
2196 '/behaviou*r/i',
2197 '/binding/i',
2198 '/include-source/i',
2199 '/javascript/i',
2200 '/script/i',
2201 '/position/i');
2202 $replace = Array('','idiocy', 'idiocy', 'idiocy', 'idiocy', 'idiocy', 'idiocy', '');
2203 $contentNew = preg_replace($match, $replace, $contentTemp);
2204 if ($contentNew !== $contentTemp) {
2205 // insecure css declarations are used. From now on we don't care
2206 // anymore if the css is destroyed by sq_deent, sq_unspace or sq_unbackslash
2207 $content = $contentNew;
2208 }
2209 return array($content, $newpos);
2210 }
2211
2212
2213 /**
2214 * This function converts cid: url's into the ones that can be viewed in
2215 * the browser.
2216 *
2217 * @param $message the message object
2218 * @param $id the message id
2219 * @param $cidurl the cid: url.
2220 * @param $mailbox the message mailbox
2221 * @return a string with a http-friendly url
2222 */
2223 function sq_cid2http($message, $id, $cidurl, $mailbox){
2224 /**
2225 * Get rid of quotes.
2226 */
2227 $quotchar = substr($cidurl, 0, 1);
2228 if ($quotchar == '"' || $quotchar == "'"){
2229 $cidurl = str_replace($quotchar, "", $cidurl);
2230 } else {
2231 $quotchar = '';
2232 }
2233 $cidurl = substr(trim($cidurl), 4);
2234
2235 $match_str = '/\{.*?\}\//';
2236 $str_rep = '';
2237 $cidurl = preg_replace($match_str, $str_rep, $cidurl);
2238
2239 $linkurl = find_ent_id($cidurl, $message);
2240 /* in case of non-safe cid links $httpurl should be replaced by a sort of
2241 unsafe link image */
2242 $httpurl = '';
2243
2244 /**
2245 * This is part of a fix for Outlook Express 6.x generating
2246 * cid URLs without creating content-id headers. These images are
2247 * not part of the multipart/related html mail. The html contains
2248 * <img src="cid:{some_id}/image_filename.ext"> references to
2249 * attached images with as goal to render them inline although
2250 * the attachment disposition property is not inline.
2251 */
2252
2253 if (empty($linkurl)) {
2254 if (preg_match('/{.*}\//', $cidurl)) {
2255 $cidurl = preg_replace('/{.*}\//','', $cidurl);
2256 if (!empty($cidurl)) {
2257 $linkurl = find_ent_id($cidurl, $message);
2258 }
2259 }
2260 }
2261
2262 if (!empty($linkurl)) {
2263 $httpurl = $quotchar . sqm_baseuri() . 'src/download.php?absolute_dl=true&amp;' .
2264 "passed_id=$id&amp;mailbox=" . urlencode($mailbox) .
2265 '&amp;ent_id=' . $linkurl . $quotchar;
2266 } else {
2267 /**
2268 * If we couldn't generate a proper img url, drop in a blank image
2269 * instead of sending back empty, otherwise it causes unusual behaviour
2270 */
2271 $httpurl = $quotchar . SM_PATH . 'images/blank.png' . $quotchar;
2272 }
2273
2274 return $httpurl;
2275 }
2276
2277 /**
2278 * This function changes the <body> tag into a <div> tag since we
2279 * can't really have a body-within-body.
2280 *
2281 * @param $attary an array of attributes and values of <body>
2282 * @param $mailbox mailbox we're currently reading (for cid2http)
2283 * @param $message current message (for cid2http)
2284 * @param $id current message id (for cid2http)
2285 * @return a modified array of attributes to be set for <div>
2286 */
2287 function sq_body2div($attary, $mailbox, $message, $id){
2288 $me = 'sq_body2div';
2289 $divattary = Array('class' => "'bodyclass'");
2290 $text = '#000000';
2291 $has_bgc_stl = $has_txt_stl = false;
2292 $styledef = '';
2293 if (is_array($attary) && sizeof($attary) > 0){
2294 foreach ($attary as $attname=>$attvalue){
2295 $quotchar = substr($attvalue, 0, 1);
2296 $attvalue = str_replace($quotchar, "", $attvalue);
2297 switch ($attname){
2298 case 'background':
2299 $attvalue = sq_cid2http($message, $id, $attvalue, $mailbox);
2300 $styledef .= "background-image: url('$attvalue'); ";
2301 break;
2302 case 'bgcolor':
2303 $has_bgc_stl = true;
2304 $styledef .= "background-color: $attvalue; ";
2305 break;
2306 case 'text':
2307 $has_txt_stl = true;
2308 $styledef .= "color: $attvalue; ";
2309 break;
2310 }
2311 }
2312 // Outlook defines a white bgcolor and no text color. This can lead to
2313 // white text on a white bg with certain themes.
2314 if ($has_bgc_stl && !$has_txt_stl) {
2315 $styledef .= "color: $text; ";
2316 }
2317 if (strlen($styledef) > 0){
2318 $divattary{"style"} = "\"$styledef\"";
2319 }
2320 }
2321 return $divattary;
2322 }
2323
2324 /**
2325 * This is the main function and the one you should actually be calling.
2326 * There are several variables you should be aware of an which need
2327 * special description.
2328 *
2329 * Since the description is quite lengthy, see it here:
2330 * http://linux.duke.edu/projects/mini/htmlfilter/
2331 *
2332 * @param $body the string with HTML you wish to filter
2333 * @param $tag_list see description above
2334 * @param $rm_tags_with_content see description above
2335 * @param $self_closing_tags see description above
2336 * @param $force_tag_closing see description above
2337 * @param $rm_attnames see description above
2338 * @param $bad_attvals see description above
2339 * @param $add_attr_to_tag see description above
2340 * @param $message message object
2341 * @param $id message id
2342 * @param $recursively_called boolean flag for recursive calls into this function (optional; default FALSE)
2343 * @return sanitized html safe to show on your pages.
2344 */
2345 function sq_sanitize($body,
2346 $tag_list,
2347 $rm_tags_with_content,
2348 $self_closing_tags,
2349 $force_tag_closing,
2350 $rm_attnames,
2351 $bad_attvals,
2352 $add_attr_to_tag,
2353 $message,
2354 $id,
2355 $mailbox,
2356 $recursively_called=FALSE
2357 ){
2358 $me = 'sq_sanitize';
2359
2360 /**
2361 * See if tag_list is of tags to remove or tags to allow.
2362 * false means remove these tags
2363 * true means allow these tags
2364 */
2365 $orig_tag_list = $tag_list;
2366 $rm_tags = array_shift($tag_list);
2367
2368 /**
2369 * Normalize rm_tags and rm_tags_with_content.
2370 */
2371 @array_walk($tag_list, 'sq_casenormalize');
2372 @array_walk($rm_tags_with_content, 'sq_casenormalize');
2373 @array_walk($self_closing_tags, 'sq_casenormalize');
2374
2375 $curpos = 0;
2376 $open_tags = Array();
2377 $trusted = "\n<!-- begin sanitized html -->\n";
2378 $skip_content = false;
2379 /**
2380 * Take care of netscape's stupid javascript entities like
2381 * &{alert('boo')};
2382 */
2383 $body = preg_replace("/&(\{.*?\};)/si", "&amp;\\1", $body);
2384
2385 while (($curtag = sq_getnxtag($body, $curpos)) != FALSE){
2386 list($tagname, $attary, $tagtype, $lt, $gt) = $curtag;
2387
2388 /**
2389 * RCDATA and RAWTEXT tags are handled differently:
2390 * next instance of closing tag is used, whether or not
2391 * the HTML is well formed before that
2392 */
2393 global $rcdata_rawtext_tags;
2394 if (!$recursively_called
2395 && in_array($tagname, $rcdata_rawtext_tags)
2396 && $tagtype === 1){
2397 $closing_tag = false;
2398 $closing_tag_offset = $curpos;
2399 // seek out the closing tag for the current RCDATA/RAWTEXT tag
2400 while (1) {
2401 // first we need to move forward to next available closing tag
2402 // (intentionally leave off the closing > and let sq_getnxtag() validate a proper tag syntax)
2403 $next_tag = sq_findnxreg($body, $closing_tag_offset, "</\s*$tagname");
2404 if ($next_tag === false) {
2405 $closing_tag = false;
2406 break;
2407 }
2408 // but then we have to make sure it's a well-formed tag
2409 $closing_tag = sq_getnxtag($body, $next_tag[0]);
2410 if ($closing_tag === false)
2411 break;
2412 else if ($closing_tag[0] !== false
2413 // these should be redundant
2414 && $closing_tag[0] === $tagname && $closing_tag[2] === 2) {
2415 $trusted .= sq_sanitize(substr($body, $curpos, $closing_tag[4] - $curpos + 1),
2416 $orig_tag_list, $rm_tags_with_content, $self_closing_tags,
2417 $force_tag_closing, $rm_attnames, $bad_attvals, $add_attr_to_tag,
2418 $message, $id, $mailbox, true);
2419 $curpos = $closing_tag[4] + 1;
2420 continue 2;
2421 }
2422 $closing_tag_offset = $next_tag[0] + 1;
2423 }
2424 if ($closing_tag === false)
2425 { /* no-op... there was no closing tag for this RCDATA/RAWTEXT tag - we could probably set $curpos to the end of $body, but this HTML is malformed anyway and should just fall apart on its own */ }
2426 }
2427
2428 $free_content = substr($body, $curpos, $lt-$curpos);
2429 /**
2430 * Take care of <style>
2431 */
2432 if ($tagname == "style" && $tagtype == 1){
2433 list($free_content, $curpos) =
2434 sq_fixstyle($body, $gt+1, $message, $id, $mailbox);
2435 if ($free_content != FALSE){
2436 if ( !empty($attary) ) {
2437 $attary = sq_fixatts($tagname,
2438 $attary,
2439 $rm_attnames,
2440 $bad_attvals,
2441 $add_attr_to_tag,
2442 $message,
2443 $id,
2444 $mailbox
2445 );
2446 }
2447 $trusted .= sq_tagprint($tagname, $attary, $tagtype);
2448 $trusted .= $free_content;
2449 $trusted .= sq_tagprint($tagname, false, 2);
2450 }
2451 continue;
2452 }
2453 if ($skip_content == false){
2454 $trusted .= $free_content;
2455 }
2456 if ($tagname != FALSE){
2457 if ($tagtype == 2){
2458 if ($skip_content == $tagname){
2459 /**
2460 * Got to the end of tag we needed to remove.
2461 */
2462 $tagname = false;
2463 $skip_content = false;
2464 } else {
2465 if ($skip_content == false){
2466 if ($tagname == "body"){
2467 $tagname = "div";
2468 }
2469 if (isset($open_tags{$tagname}) &&
2470 $open_tags{$tagname} > 0){
2471 $open_tags{$tagname}--;
2472 } else {
2473 $tagname = false;
2474 }
2475 }
2476 }
2477 } else {
2478 /**
2479 * $rm_tags_with_content
2480 */
2481 if ($skip_content == false){
2482 /**
2483 * See if this is a self-closing type and change
2484 * tagtype appropriately.
2485 */
2486 if ($tagtype == 1
2487 && in_array($tagname, $self_closing_tags)){
2488 $tagtype = 3;
2489 }
2490 /**
2491 * See if we should skip this tag and any content
2492 * inside it.
2493 */
2494 if ($tagtype == 1 &&
2495 in_array($tagname, $rm_tags_with_content)){
2496 $skip_content = $tagname;
2497 } else {
2498 if (($rm_tags == false
2499 && in_array($tagname, $tag_list)) ||
2500 ($rm_tags == true &&
2501 !in_array($tagname, $tag_list))){
2502 $tagname = false;
2503 } else {
2504 /**
2505 * Convert body into div.
2506 */
2507 if ($tagname == "body"){
2508 $tagname = "div";
2509 $attary = sq_body2div($attary, $mailbox,
2510 $message, $id);
2511 }
2512 if ($tagtype == 1){
2513 if (isset($open_tags{$tagname})){
2514 $open_tags{$tagname}++;
2515 } else {
2516 $open_tags{$tagname}=1;
2517 }
2518 }
2519 /**
2520 * This is where we run other checks.
2521 */
2522 if (is_array($attary) && sizeof($attary) > 0){
2523 $attary = sq_fixatts($tagname,
2524 $attary,
2525 $rm_attnames,
2526 $bad_attvals,
2527 $add_attr_to_tag,
2528 $message,
2529 $id,
2530 $mailbox
2531 );
2532 }
2533 }
2534 }
2535 }
2536 }
2537 if ($tagname != false && $skip_content == false){
2538 $trusted .= sq_tagprint($tagname, $attary, $tagtype);
2539 }
2540 }
2541 $curpos = $gt+1;
2542 }
2543 $trusted .= substr($body, $curpos, strlen($body)-$curpos);
2544 if ($force_tag_closing == true){
2545 foreach ($open_tags as $tagname=>$opentimes){
2546 while ($opentimes > 0){
2547 $trusted .= '</' . $tagname . '>';
2548 $opentimes--;
2549 }
2550 }
2551 $trusted .= "\n";
2552 }
2553 $trusted .= "<!-- end sanitized html -->\n";
2554 return $trusted;
2555 }
2556
2557 /**
2558 * This is a wrapper function to call html sanitizing routines.
2559 *
2560 * @param $body the body of the message
2561 * @param $id the id of the message
2562
2563 * @param $message
2564 * @param $mailbox
2565 * @param boolean $take_mailto_links When TRUE, converts mailto: links
2566 * into internal SM compose links
2567 * (optional; default = TRUE)
2568 * @return a string with html safe to display in the browser.
2569 */
2570 function magicHTML($body, $id, $message, $mailbox = 'INBOX', $take_mailto_links =true) {
2571
2572 // require_once(SM_PATH . 'functions/url_parser.php'); // for $MailTo_PReg_Match
2573
2574 global $attachment_common_show_images, $view_unsafe_images,
2575 $has_unsafe_images, $allow_svg_display, $rcdata_rawtext_tags,
2576 $remove_rcdata_rawtext_tags_and_content;
2577
2578 $rcdata_rawtext_tags = array(
2579 "noscript",
2580 "noframes",
2581 "noembed",
2582 "textarea",
2583 // also "title", "xmp", "script", "iframe", "plaintext" which we already remove below
2584 );
2585
2586 /**
2587 * Don't display attached images in HTML mode.
2588 *
2589 * SB: why?
2590 */
2591 $attachment_common_show_images = false;
2592 $tag_list = Array(
2593 false, // remove these tags
2594 "meta",
2595 "html",
2596 "head",
2597 "base",
2598 "link",
2599 "frame",
2600 "iframe",
2601 "plaintext",
2602 "marquee",
2603 );
2604
2605 $rm_tags_with_content = Array(
2606 "script",
2607 "object",
2608 "applet",
2609 "embed",
2610 "title",
2611 "frameset",
2612 "xmp",
2613 "xml",
2614 );
2615 if (!$allow_svg_display)
2616 $rm_tags_with_content[] = 'svg';
2617 /**
2618 * SquirrelMail will parse RCDATA and RAWTEXT tags and handle them as the special
2619 * case that they are, but if you prefer to remove them and their contents entirely
2620 * (in most cases, should be a safe thing with minimal impact), you can add the
2621 * following to config/config_local.php
2622 * $remove_rcdata_rawtext_tags_and_content = TRUE;
2623 */
2624 if ($remove_rcdata_rawtext_tags_and_content)
2625 $rm_tags_with_content = array_merge($rm_tags_with_content, $rcdata_rawtext_tags);
2626
2627 $self_closing_tags = Array(
2628 "img",
2629 "br",
2630 "hr",
2631 "input",
2632 "outbind",
2633 );
2634
2635 $force_tag_closing = true;
2636
2637 $rm_attnames = Array(
2638 "/.*/" =>
2639 Array(
2640 "/target/i",
2641 "/^on.*/i",
2642 "/^dynsrc/i",
2643 "/^data.*/i",
2644 "/^lowsrc.*/i",
2645 )
2646 );
2647
2648 global $use_transparent_security_image;
2649 if ($use_transparent_security_image) $secremoveimg = '../images/spacer.png';
2650 else $secremoveimg = '../images/' . _("sec_remove_eng.png");
2651
2652 $bad_attvals = Array(
2653 "/.*/" =>
2654 Array(
2655 "/^src|background/i" =>
2656 Array(
2657 Array(
2658 "/^([\'\"])\s*\S+script\s*:.*([\'\"])/si",
2659 "/^([\'\"])\s*mocha\s*:*.*([\'\"])/si",
2660 "/^([\'\"])\s*about\s*:.*([\'\"])/si"
2661 ),
2662 Array(
2663 "\\1$secremoveimg\\2",
2664 "\\1$secremoveimg\\2",
2665 "\\1$secremoveimg\\2",
2666 )
2667 ),
2668 "/^href|action/i" =>
2669 Array(
2670 Array(
2671 "/^([\'\"])\s*\S+script\s*:.*([\'\"])/si",
2672 "/^([\'\"])\s*mocha\s*:*.*([\'\"])/si",
2673 "/^([\'\"])\s*about\s*:.*([\'\"])/si"
2674 ),
2675 Array(
2676 "\\1#\\1",
2677 "\\1#\\1",
2678 "\\1#\\1"
2679 )
2680 ),
2681 "/^style/i" =>
2682 Array(
2683 Array(
2684 "/\/\*.*\*\//",
2685 "/expression/i",
2686 "/binding/i",
2687 "/behaviou*r/i",
2688 "/include-source/i",
2689
2690 // position:relative can also be exploited
2691 // to put content outside of email body area
2692 // and position:fixed is similarly exploitable
2693 // as position:absolute, so we'll remove it
2694 // altogether....
2695 //
2696 // Does this screw up legitimate HTML messages?
2697 // If so, the only fix I see is to allow position
2698 // attributes (any values? I think we still have
2699 // to block static and fixed) only if $use_iframe
2700 // is enabled (1.5.0+)
2701 //
2702 // was: "/position\s*:\s*absolute/i",
2703 //
2704 "/position\s*:/i",
2705
2706 "/(\\\\)?u(\\\\)?r(\\\\)?l(\\\\)?/i",
2707 "/url\s*\(\s*([\'\"])\s*\S+script\s*:.*([\'\"])\s*\)/si",
2708 "/url\s*\(\s*([\'\"])\s*mocha\s*:.*([\'\"])\s*\)/si",
2709 "/url\s*\(\s*([\'\"])\s*about\s*:.*([\'\"])\s*\)/si",
2710 "/(.*)\s*:\s*url\s*\(\s*([\'\"]*)\s*\S+script\s*:.*([\'\"]*)\s*\)/si",
2711 ),
2712 Array(
2713 "",
2714 "idiocy",
2715 "idiocy",
2716 "idiocy",
2717 "idiocy",
2718 "idiocy",
2719 "url",
2720 "url(\\1#\\1)",
2721 "url(\\1#\\1)",
2722 "url(\\1#\\1)",
2723 "\\1:url(\\2#\\3)"
2724 )
2725 )
2726 )
2727 );
2728
2729 // If there's no "view_unsafe_images" variable in the URL, turn unsafe
2730 // images off by default.
2731 sqgetGlobalVar('view_unsafe_images', $view_unsafe_images, SQ_GET, FALSE);
2732
2733 if (!$view_unsafe_images){
2734 /**
2735 * Remove any references to http/https if view_unsafe_images set
2736 * to false.
2737 */
2738 array_push($bad_attvals{'/.*/'}{'/^src|background/i'}[0],
2739 '/^([\'\"])\s*https*:.*([\'\"])/si');
2740 array_push($bad_attvals{'/.*/'}{'/^src|background/i'}[1],
2741 "\\1$secremoveimg\\1");
2742 array_push($bad_attvals{'/.*/'}{'/^style/i'}[0],
2743 '/url\([\'\"]?https?:[^\)]*[\'\"]?\)/si');
2744 array_push($bad_attvals{'/.*/'}{'/^style/i'}[1],
2745 "url(\\1$secremoveimg\\1)");
2746 }
2747
2748 $add_attr_to_tag = Array(
2749 "/^a$/i" =>
2750 Array('target'=>'"_blank"',
2751 'title'=>'"'._("This external link will open in a new window").'"'
2752 )
2753 );
2754 $trusted = sq_sanitize($body,
2755 $tag_list,
2756 $rm_tags_with_content,
2757 $self_closing_tags,
2758 $force_tag_closing,
2759 $rm_attnames,
2760 $bad_attvals,
2761 $add_attr_to_tag,
2762 $message,
2763 $id,
2764 $mailbox
2765 );
2766 if (strpos($trusted,$secremoveimg)){
2767 $has_unsafe_images = true;
2768 }
2769
2770 // we want to parse mailto's in HTML output, change to SM compose links
2771 // this is a modified version of code from url_parser.php... but Marc is
2772 // right: we need a better filtering implementation; adding this randomly
2773 // here is not a great solution
2774 //
2775 if ($take_mailto_links) {
2776 // parseUrl($trusted); // this even parses URLs inside of tags... too aggressive
2777 global $MailTo_PReg_Match;
2778 // some mailers (Microsoft, surprise surprise) produce mailto strings without being
2779 // inside an anchor (link) tag, so we have to make sure the regex looks for the
2780 // quote before mailto, and we'll also try to convert the non-links back into links
2781 $MailTo_PReg_Match = '/([\'"])?mailto:' . substr($MailTo_PReg_Match, 1) ;
2782 if ((preg_match_all($MailTo_PReg_Match, $trusted, $regs)) && ($regs[0][0] != '')) {
2783 foreach ($regs[0] as $i => $mailto_before) {
2784 $mailto_params = $regs[11][$i];
2785
2786 // get rid of any leading quote we may have captured but don't care about
2787 //
2788 $mailto_before = ltrim($mailto_before, '"\'');
2789
2790 // get rid of any tailing quote since we have to add send_to to the end
2791 //
2792 $mailto_before = rtrim($mailto_before, '"\'');
2793 $mailto_params = rtrim($mailto_params, '"\'');
2794
2795 if ($regs[2][$i]) { //if there is an email addr before '?', we need to merge it with the params
2796 $to = 'to=' . $regs[2][$i];
2797 if (strpos($mailto_params, 'to=') > -1) //already a 'to='
2798 $mailto_params = str_replace('to=', $to . '%2C%20', $mailto_params);
2799 else {
2800 if ($mailto_params) //already some params, append to them
2801 $mailto_params .= '&amp;' . $to;
2802 else
2803 $mailto_params .= '?' . $to;
2804 }
2805 }
2806
2807 $url_str = preg_replace(array('/to=/i', '/(?<!b)cc=/i', '/bcc=/i'), array('send_to=', 'send_to_cc=', 'send_to_bcc='), $mailto_params);
2808
2809 // we'll already have target=_blank, no need to allow comp_in_new
2810 // here (which would be a lot more work anyway)
2811 //
2812 global $compose_new_win;
2813 $temp_comp_in_new = $compose_new_win;
2814 $compose_new_win = 0;
2815 $comp_uri = makeComposeLink('src/compose.php' . $url_str, $mailto_before);
2816 $compose_new_win = $temp_comp_in_new;
2817
2818 // remove <a href=" and anything after the next quote (we only
2819 // need the uri, not the link HTML) in compose uri
2820 //
2821 // but only do this if the original mailto was in a real anchor tag
2822 //
2823 if (!empty($regs[1][$i])) {
2824 $comp_uri = substr($comp_uri, 9);
2825 $comp_uri = substr($comp_uri, 0, strpos($comp_uri, '"', 1));
2826 }
2827 $trusted = str_replace($mailto_before, $comp_uri, $trusted);
2828 }
2829 }
2830 }
2831
2832 return $trusted;
2833 }
2834
2835 /**
2836 * function SendDownloadHeaders - send file to the browser
2837 *
2838 * Original Source: SM core src/download.php
2839 * moved here to make it available to other code, and separate
2840 * front end from back end functionality.
2841 *
2842 * @param string $type0 first half of mime type
2843 * @param string $type1 second half of mime type
2844 * @param string $filename filename to tell the browser for downloaded file
2845 * @param boolean $force whether to force the download dialog to pop
2846 * @param optional integer $filesize send the Content-Header and length to the browser
2847 * @return void
2848 */
2849 function SendDownloadHeaders($type0, $type1, $filename, $force, $filesize=0) {
2850 global $languages, $squirrelmail_language;
2851 $isIE = $isIE6plus = false;
2852
2853 sqgetGlobalVar('HTTP_USER_AGENT', $HTTP_USER_AGENT, SQ_SERVER);
2854
2855 if (strstr($HTTP_USER_AGENT, 'compatible; MSIE ') !== false &&
2856 strstr($HTTP_USER_AGENT, 'Opera') === false) {
2857 $isIE = true;
2858 }
2859
2860 if (preg_match('/compatible; MSIE ([0-9]+)/', $HTTP_USER_AGENT, $match) &&
2861 ((int)$match[1]) >= 6 && strstr($HTTP_USER_AGENT, 'Opera') === false) {
2862 $isIE6plus = true;
2863 }
2864
2865 if (isset($languages[$squirrelmail_language]['XTRA_CODE']) &&
2866 function_exists($languages[$squirrelmail_language]['XTRA_CODE'] . '_downloadfilename')) {
2867 $filename =
2868 call_user_func($languages[$squirrelmail_language]['XTRA_CODE'] . '_downloadfilename', $filename, $HTTP_USER_AGENT);
2869 } else {
2870 $filename = preg_replace('/[\\\\\/:*?"<>|;]/', '_', str_replace('&nbsp;', ' ', $filename));
2871 }
2872
2873 // A Pox on Microsoft and it's Internet Explorer!
2874 //
2875 // IE has lots of bugs with file downloads.
2876 // It also has problems with SSL. Both of these cause problems
2877 // for us in this function.
2878 //
2879 // See this article on Cache Control headers and SSL
2880 // http://support.microsoft.com/default.aspx?scid=kb;en-us;323308
2881 //
2882 // The best thing you can do for IE is to upgrade to the latest
2883 // version
2884 //set all the Cache Control Headers for IE
2885 if ($isIE) {
2886 $filename=rawurlencode($filename);
2887 header ("Pragma: public");
2888 header ("Cache-Control: no-store, max-age=0, no-cache, must-revalidate"); // HTTP/1.1
2889 // does nothing - see: https://blogs.msdn.microsoft.com/ieinternals/2009/07/20/internet-explorers-cache-control-extensions/
2890 // header ("Cache-Control: post-check=0, pre-check=0", false);
2891 header ("Cache-Control: private");
2892
2893 //set the inline header for IE, we'll add the attachment header later if we need it
2894 header ("Content-Disposition: inline; filename=$filename");
2895 }
2896
2897 if (!$force) {
2898 // Try to show in browser window
2899 header ("Content-Disposition: inline; filename=\"$filename\"");
2900 header ("Content-Type: $type0/$type1; name=\"$filename\"");
2901 } else {
2902 // Try to pop up the "save as" box
2903
2904 // IE makes this hard. It pops up 2 save boxes, or none.
2905 // http://support.microsoft.com/support/kb/articles/Q238/5/88.ASP
2906 // http://support.microsoft.com/default.aspx?scid=kb;EN-US;260519
2907 // But, according to Microsoft, it is "RFC compliant but doesn't
2908 // take into account some deviations that allowed within the
2909 // specification." Doesn't that mean RFC non-compliant?
2910 // http://support.microsoft.com/support/kb/articles/Q258/4/52.ASP
2911
2912 // all browsers need the application/octet-stream header for this
2913 header ("Content-Type: application/octet-stream; name=\"$filename\"");
2914
2915 // http://support.microsoft.com/support/kb/articles/Q182/3/15.asp
2916 // Do not have quotes around filename, but that applied to
2917 // "attachment"... does it apply to inline too?
2918 header ("Content-Disposition: attachment; filename=\"$filename\"");
2919
2920 if ($isIE && !$isIE6plus) {
2921 // This combination seems to work mostly. IE 5.5 SP 1 has
2922 // known issues (see the Microsoft Knowledge Base)
2923
2924 // This works for most types, but doesn't work with Word files
2925 header ("Content-Type: application/download; name=\"$filename\"");
2926 header ("Content-Type: application/force-download; name=\"$filename\"");
2927 // These are spares, just in case. :-)
2928 //header("Content-Type: $type0/$type1; name=\"$filename\"");
2929 //header("Content-Type: application/x-msdownload; name=\"$filename\"");
2930 //header("Content-Type: application/octet-stream; name=\"$filename\"");
2931 } else if ($isIE) {
2932 // This is to prevent IE for MIME sniffing and auto open a file in IE
2933 header ("Content-Type: application/force-download; name=\"$filename\"");
2934 } else {
2935 // another application/octet-stream forces download for Netscape
2936 header ("Content-Type: application/octet-stream; name=\"$filename\"");
2937 }
2938 }
2939
2940 //send the content-length header if the calling function provides it
2941 if ($filesize > 0) {
2942 header("Content-Length: $filesize");
2943 }
2944
2945 } // end fn SendDownloadHeaders