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