functions/mime.php

   1 <?php
   2
   3 /**
   4  * mime.php
   5  *
   6  * Copyright (c) 1999-2005 The SquirrelMail Project Team
   7  * Licensed under the GNU GPL. For full terms see the file COPYING.
   8  *
   9  * This contains the functions necessary to detect and decode MIME
  10  * messages.
  11  *
  12  * @version $Id$
  13  * @package squirrelmail
  14  */
  15
  16 /** The typical includes... */
  17 require_once(SM_PATH . 'functions/imap.php');
  18 require_once(SM_PATH . 'functions/attachment_common.php');
  19 /** add sqm_baseuri()*/
  20 include_once(SM_PATH . 'functions/display_messages.php');
  21
  22 /* -------------------------------------------------------------------------- */
  23 /* MIME DECODING                                                              */
  24 /* -------------------------------------------------------------------------- */
  25
  26 /**
  27  * Get the MIME structure
  28  *
  29  * This function gets the structure of a message and stores it in the "message" class.
  30  * It will return this object for use with all relevant header information and
  31  * fully parsed into the standard "message" object format.
  32  */
  33 function mime_structure ($bodystructure, $flags=array()) {
  34
  35     /* Isolate the body structure and remove beginning and end parenthesis. */
  36     $read = trim(substr ($bodystructure, strpos(strtolower($bodystructure), 'bodystructure') + 13));
  37     $read = trim(substr ($read, 0, -1));
  38     $i = 0;
  39     $msg = Message::parseStructure($read,$i);
  40     if (!is_object($msg)) {
  41         include_once(SM_PATH . 'functions/display_messages.php');
  42         global $color, $mailbox;
  43         /* removed urldecode because $_GET is auto urldecoded ??? */
  44         displayPageHeader( $color, $mailbox );
  45         $errormessage  = _("SquirrelMail could not decode the bodystructure of the message");
  46         $errormessage .= '<br />'._("The bodystructure provided by your IMAP server:").'<br /><br />';
  47         $errormessage .= '<pre>' . htmlspecialchars($read) . '</pre>';
  48         plain_error_message( $errormessage, $color );
  49         echo '</body></html>';
  50         exit;
  51     }
  52     if (count($flags)) {
  53         foreach ($flags as $flag) {
  54             $char = strtoupper($flag{1});
  55             switch ($char) {
  56                 case 'S':
  57                     if (strtolower($flag) == '\\seen') {
  58                         $msg->is_seen = true;
  59                     }
  60                     break;
  61                 case 'A':
  62                     if (strtolower($flag) == '\\answered') {
  63                         $msg->is_answered = true;
  64                     }
  65                     break;
  66                 case 'D':
  67                     if (strtolower($flag) == '\\deleted') {
  68                         $msg->is_deleted = true;
  69                     }
  70                     break;
  71                 case 'F':
  72                     if (strtolower($flag) == '\\flagged') {
  73                         $msg->is_flagged = true;
  74                     }
  75                     break;
  76                 case 'M':
  77                     if (strtolower($flag) == '$mdnsent') {
  78                         $msg->is_mdnsent = true;
  79                     }
  80                     break;
  81                 default:
  82                     break;
  83             }
  84         }
  85     }
  86     //    listEntities($msg);
  87     return $msg;
  88 }
  89
  90
  91
  92 /* This starts the parsing of a particular structure.  It is called recursively,
  93  * so it can be passed different structures.  It returns an object of type
  94  * $message.
  95  * First, it checks to see if it is a multipart message.  If it is, then it
  96  * handles that as it sees is necessary.  If it is just a regular entity,
  97  * then it parses it and adds the necessary header information (by calling out
  98  * to mime_get_elements()
  99  */
 100
 101 function mime_fetch_body($imap_stream, $id, $ent_id=1, $fetch_size=0) {
 102     /* Do a bit of error correction.  If we couldn't find the entity id, just guess
 103      * that it is the first one.  That is usually the case anyway.
 104      */
 105
 106     if (!$ent_id) {
 107         $cmd = "FETCH $id BODY[]";
 108     } else {
 109         $cmd = "FETCH $id BODY[$ent_id]";
 110     }
 111
 112     if ($fetch_size!=0) $cmd .= "<0.$fetch_size>";
 113
 114     $data = sqimap_run_command ($imap_stream, $cmd, true, $response, $message, TRUE);
 115     do {
 116         $topline = trim(array_shift($data));
 117     } while($topline && ($topline[0] == '*') && !preg_match('/\* [0-9]+ FETCH.*/i', $topline)) ;
 118
 119     $wholemessage = implode('', $data);
 120     if (ereg('\\{([^\\}]*)\\}', $topline, $regs)) {
 121         $ret = substr($wholemessage, 0, $regs[1]);
 122         /* There is some information in the content info header that could be important
 123          * in order to parse html messages. Let's get them here.
 124          */
 125 //        if ($ret{0} == '<') {
 126 //            $data = sqimap_run_command ($imap_stream, "FETCH $id BODY[$ent_id.MIME]", true, $response, $message, TRUE);
 127 //        }
 128     } else if (ereg('"([^"]*)"', $topline, $regs)) {
 129         $ret = $regs[1];
 130     } else {
 131         global $where, $what, $mailbox, $passed_id, $startMessage;
 132         $par = 'mailbox=' . urlencode($mailbox) . '&amp;passed_id=' . $passed_id;
 133         if (isset($where) && isset($what)) {
 134             $par .= '&amp;where=' . urlencode($where) . '&amp;what=' . urlencode($what);
 135         } else {
 136             $par .= '&amp;startMessage=' . $startMessage . '&amp;show_more=0';
 137         }
 138         $par .= '&amp;response=' . urlencode($response) .
 139             '&amp;message='  . urlencode($message)  .
 140             '&amp;topline='  . urlencode($topline);
 141
 142         echo '<tt><br />' .
 143             '<table width="80%"><tr>' .
 144             '<tr><td colspan="2">' .
 145             _("Body retrieval error. The reason for this is most probably that the message is malformed.") .
 146             '</td></tr>' .
 147             '<tr><td><b>' . _("Command:") . "</td><td>$cmd</td></tr>" .
 148             '<tr><td><b>' . _("Response:") . "</td><td>$response</td></tr>" .
 149             '<tr><td><b>' . _("Message:") . "</td><td>$message</td></tr>" .
 150             '<tr><td><b>' . _("FETCH line:") . "</td><td>$topline</td></tr>" .
 151             "</table><br /></tt></font><hr />";
 152
 153         $data = sqimap_run_command ($imap_stream, "FETCH $passed_id BODY[]", true, $response, $message, TRUE);
 154         array_shift($data);
 155         $wholemessage = implode('', $data);
 156
 157         $ret = $wholemessage;
 158     }
 159     return $ret;
 160 }
 161
 162 function mime_print_body_lines ($imap_stream, $id, $ent_id=1, $encoding, $rStream='php://stdout') {
 163
 164     /* Don't kill the connection if the browser is over a dialup
 165      * and it would take over 30 seconds to download it.
 166      * Don't call set_time_limit in safe mode.
 167      */
 168
 169     if (!ini_get('safe_mode')) {
 170         set_time_limit(0);
 171     }
 172     /* in case of base64 encoded attachments, do not buffer them.
 173        Instead, echo the decoded attachment directly to screen */
 174     if (strtolower($encoding) == 'base64') {
 175         if (!$ent_id) {
 176             $query = "FETCH $id BODY[]";
 177         } else {
 178             $query = "FETCH $id BODY[$ent_id]";
 179         }
 180         sqimap_run_command($imap_stream,$query,true,$response,$message,TRUE,'sqimap_base64_decode',$rStream,true);
 181     } else {
 182         $body = mime_fetch_body ($imap_stream, $id, $ent_id);
 183         if (is_resource($rStream)) {
 184             fputs($rStream,decodeBody($body,$encoding));
 185         } else {
 186             echo decodeBody($body, $encoding);
 187         }
 188     }
 189
 190     /*
 191        TODO, use the same method for quoted printable.
 192        However, I assume that quoted printable attachments aren't that large
 193        so the performancegain / memory usage drop will be minimal.
 194        If we decide to add that then we need to adapt sqimap_fread because
 195        we need to split te result on \n and fread doesn't stop at \n. That
 196        means we also should provide $results from sqimap_fread (by ref) to
 197        te function and set $no_return to false. The $filter function for
 198        quoted printable should handle unsetting of $results.
 199      */
 200     /*
 201        TODO 2: find out how we write to the output stream php://stdout. fwrite
 202        doesn't work because 'php://stdout isn't a stream.
 203      */
 204
 205     return;
 206 }
 207
 208 /* -[ END MIME DECODING ]----------------------------------------------------------- */
 209
 210 /* This is here for debugging purposes.  It will print out a list
 211  * of all the entity IDs that are in the $message object.
 212  */
 213 function listEntities ($message) {
 214     if ($message) {
 215         echo "<tt>" . $message->entity_id . ' : ' . $message->type0 . '/' . $message->type1 . ' parent = '. $message->parent->entity_id. '<br />';
 216         for ($i = 0; isset($message->entities[$i]); $i++) {
 217             echo "$i : ";
 218             $msg = listEntities($message->entities[$i]);
 219
 220             if ($msg) {
 221                 echo "return: ";
 222                 return $msg;
 223             }
 224         }
 225     }
 226 }
 227
 228 function getPriorityStr($priority) {
 229     $priority_level = substr($priority,0,1);
 230
 231     switch($priority_level) {
 232         /* Check for a higher then normal priority. */
 233         case '1':
 234         case '2':
 235             $priority_string = _("High");
 236             break;
 237
 238         /* Check for a lower then normal priority. */
 239         case '4':
 240         case '5':
 241             $priority_string = _("Low");
 242             break;
 243
 244         /* Check for a normal priority. */
 245         case '3':
 246         default:
 247             $priority_level = '3';
 248             $priority_string = _("Normal");
 249             break;
 250
 251     }
 252     return $priority_string;
 253 }
 254
 255 /* returns a $message object for a particular entity id */
 256 function getEntity ($message, $ent_id) {
 257     return $message->getEntity($ent_id);
 258 }
 259
 260 /* translateText
 261  * Extracted from strings.php 23/03/2002
 262  */
 263
 264 function translateText(&$body, $wrap_at, $charset) {
 265     global $where, $what;   /* from searching */
 266     global $color;          /* color theme */
 267
 268     require_once(SM_PATH . 'functions/url_parser.php');
 269
 270     $body_ary = explode("\n", $body);
 271     for ($i=0; $i < count($body_ary); $i++) {
 272         $line = $body_ary[$i];
 273         if (strlen($line) - 2 >= $wrap_at) {
 274             sqWordWrap($line, $wrap_at, $charset);
 275         }
 276         $line = charset_decode($charset, $line);
 277         $line = str_replace("\t", '        ', $line);
 278
 279         parseUrl ($line);
 280
 281         $quotes = 0;
 282         $pos = 0;
 283         $j = strlen($line);
 284
 285         while ($pos < $j) {
 286             if ($line[$pos] == ' ') {
 287                 $pos++;
 288             } else if (strpos($line, '&gt;', $pos) === $pos) {
 289                 $pos += 4;
 290                 $quotes++;
 291             } else {
 292                 break;
 293             }
 294         }
 295
 296         if ($quotes % 2) {
 297             if (!isset($color[13])) {
 298                 $color[13] = '#800000';
 299             }
 300             $line = '<font color="' . $color[13] . '">' . $line . '</font>';
 301         } elseif ($quotes) {
 302             if (!isset($color[14])) {
 303                 $color[14] = '#FF0000';
 304             }
 305             $line = '<font color="' . $color[14] . '">' . $line . '</font>';
 306         }
 307
 308         $body_ary[$i] = $line;
 309     }
 310     $body = '<pre>' . implode("\n", $body_ary) . '</pre>';
 311 }
 312
 313 /**
 314  * This returns a parsed string called $body. That string can then
 315  * be displayed as the actual message in the HTML. It contains
 316  * everything needed, including HTML Tags, Attachments at the
 317  * bottom, etc.
 318  *
 319  * Since 1.2.0 function uses message_body hook.
 320  * Till 1.3.0 function included output of formatAttachments().
 321  *
 322  * @param resource $imap_stream imap connection resource
 323  * @param object $message squirrelmail message object
 324  * @param array $color squirrelmail color theme array
 325  * @param integer $wrap_at number of characters per line
 326  * @param string $ent_num (since 1.3.0) message part id
 327  * @param integer $id (since 1.3.0) message id
 328  * @param string $mailbox (since 1.3.0) imap folder name
 329  * @param boolean $clean (since 1.5.1) Do not output stuff that's irrelevant for the printable version.
 330  * @return string html formated message text
 331  */
 332 function formatBody($imap_stream, $message, $color, $wrap_at, $ent_num, $id, $mailbox='INBOX', $clean=FALSE) {
 333     /* This if statement checks for the entity to show as the
 334      * primary message. To add more of them, just put them in the
 335      * order that is their priority.
 336      */
 337     global $startMessage, $languages, $squirrelmail_language,
 338            $show_html_default, $sort, $has_unsafe_images, $passed_ent_id, $use_iframe,$iframe_height;
 339
 340     // workaround for not updated config.php
 341     if (! isset($use_iframe)) $use_iframe = false;
 342
 343     if( !sqgetGlobalVar('view_unsafe_images', $view_unsafe_images, SQ_GET) ) {
 344         $view_unsafe_images = false;
 345     }
 346
 347     $body = '';
 348     $urlmailbox = urlencode($mailbox);
 349     $body_message = getEntity($message, $ent_num);
 350     if (($body_message->header->type0 == 'text') ||
 351             ($body_message->header->type0 == 'rfc822')) {
 352         $body = mime_fetch_body ($imap_stream, $id, $ent_num);
 353         $body = decodeBody($body, $body_message->header->encoding);
 354
 355         if (isset($languages[$squirrelmail_language]['XTRA_CODE']) &&
 356                 function_exists($languages[$squirrelmail_language]['XTRA_CODE'] . '_decode')) {
 357             if (mb_detect_encoding($body) != 'ASCII') {
 358                 $body = call_user_func($languages[$squirrelmail_language]['XTRA_CODE'] . '_decode',$body);
 359             }
 360         }
 361         $hookResults = do_hook("message_body", $body);
 362         $body = $hookResults[1];
 363
 364         /* If there are other types that shouldn't be formatted, add
 365          * them here.
 366          */
 367
 368         if ($body_message->header->type1 == 'html') {
 369             if ($show_html_default <> 1) {
 370                 $entity_conv = array('&nbsp;' => ' ',
 371                                      '<p>'    => "\n",
 372                                      '<P>'    => "\n",
 373                                      '<br>'   => "\n",
 374                                      '<BR>'   => "\n",
 375                                      '<br />' => "\n",
 376                                      '<BR />' => "\n",
 377                                      '&gt;'   => '>',
 378                                      '&lt;'   => '<');
 379                 $body = strtr($body, $entity_conv);
 380                 $body = strip_tags($body);
 381                 $body = trim($body);
 382                 translateText($body, $wrap_at,
 383                         $body_message->header->getParameter('charset'));
 384             } elseif ($use_iframe && ! $clean) {
 385                 // $clean is used to remove iframe in printable view.
 386
 387                 /**
 388                  * If we don't add html message between iframe tags,
 389                  * we must detect unsafe images and modify $has_unsafe_images.
 390                  */
 391                 $html_body =  magicHTML($body, $id, $message, $mailbox);
 392
 393                 // creating iframe url
 394                 $iframeurl=sqm_baseuri().'src/view_html.php?'
 395                     . 'mailbox=' . $urlmailbox
 396                     . '&amp;passed_id=' . $id
 397                     . '&amp;ent_id=' . $ent_num
 398                     . '&amp;view_unsafe_images=' . (int) $view_unsafe_images;
 399
 400                 // adding warning message
 401                 $body = html_tag('div',_("Viewing HTML formatted email"),'center');
 402
 403                 /**
 404                  * height can't be set to 100%, because it does not work as expected when
 405                  * iframe is inside the table. Browsers do not create full height objects
 406                  * even when iframe is not nested. Maybe there is some way to get full size
 407                  * with CSS. Tested in firefox 1.02 and opera 7.53
 408                  *
 409                  * width="100%" does not work as expected, when table width is not set (automatic)
 410                  *
 411                  * tokul: I think <iframe> are safer sandbox than <object>. Objects might
 412                  * need special handling for IE and IE6SP2.
 413                  */
 414                 $body.= "<div><iframe name=\"message_frame\" width=\"100%\" height=\"$iframe_height\" src=\"$iframeurl\""
 415                     .' frameborder="1" marginwidth="0" marginheight="0" scrolling="auto">' . "\n";
 416
 417                 // Message for browsers without iframe support
 418                 //$body.= _("Your browser does not support inline frames.
 419                 // You can view HTML formated message by following below link.");
 420                 //$body.= "<br /><a href=\"$iframeurl\">"._("View HTML Message")."</a>";
 421
 422                 // if browser can't render iframe, it renders html message.
 423                 $body.= $html_body;
 424
 425                 // close iframe
 426                 $body.="</iframe></div>\n";
 427             } else {
 428                 // old way of html rendering
 429                 $body = magicHTML($body, $id, $message, $mailbox);
 430             }
 431         } else {
 432             translateText($body, $wrap_at,
 433                     $body_message->header->getParameter('charset'));
 434         }
 435
 436         // if this is the clean display (i.e. printer friendly), stop here.
 437         if ( $clean ) {
 438             return $body;
 439         }
 440
 441         $link = 'passed_id=' . $id . '&amp;ent_id='.$ent_num.
 442             '&amp;mailbox=' . $urlmailbox .'&amp;sort=' . $sort .
 443             '&amp;startMessage=' . $startMessage . '&amp;show_more=0';
 444         if (isset($passed_ent_id)) {
 445             $link .= '&amp;passed_ent_id='.$passed_ent_id;
 446         }
 447         $body .= '<center><small><a href="download.php?absolute_dl=true&amp;' .
 448             $link . '">' . _("Download this as a file") .  '</a>';
 449         if ($view_unsafe_images) {
 450             $text = _("Hide Unsafe Images");
 451         } else {
 452             if (isset($has_unsafe_images) && $has_unsafe_images) {
 453                 $link .= '&amp;view_unsafe_images=1';
 454                 $text = _("View Unsafe Images");
 455             } else {
 456                 $text = '';
 457             }
 458         }
 459         if($text != '') {
 460             $body .= '&nbsp;|&nbsp;<a href="read_body.php?' . $link . '">' . $text . '</a>';
 461         }
 462         $body .= '</small></center><br />' . "\n";
 463     }
 464     return $body;
 465 }
 466
 467 /**
 468  * Displays attachment links and information
 469  *
 470  * Since 1.3.0 function is not included in formatBody() call.
 471  *
 472  * Since 1.0.2 uses attachment $type0/$type1 hook.
 473  * Since 1.2.5 uses attachment $type0/* hook.
 474  * Since 1.5.0 uses attachments_bottom hook.
 475  *
 476  * @param object $message SquirrelMail message object
 477  * @param array $exclude_id message parts that are not attachments.
 478  * @param string $mailbox mailbox name
 479  * @param integer $id message id
 480  * @return string html formated attachment information.
 481  */
 482 function formatAttachments($message, $exclude_id, $mailbox, $id) {
 483     global $where, $what, $startMessage, $color, $passed_ent_id;
 484
 485     $att_ar = $message->getAttachments($exclude_id);
 486
 487     if (!count($att_ar)) return '';
 488
 489     $attachments = '';
 490
 491     $urlMailbox = urlencode($mailbox);
 492
 493     foreach ($att_ar as $att) {
 494         $ent = $att->entity_id;
 495         $header = $att->header;
 496         $type0 = strtolower($header->type0);
 497         $type1 = strtolower($header->type1);
 498         $name = '';
 499         $links['download link']['text'] = _("Download");
 500         $links['download link']['href'] = sqm_baseuri() .
 501             "src/download.php?absolute_dl=true&amp;passed_id=$id&amp;mailbox=$urlMailbox&amp;ent_id=$ent";
 502         if ($type0 =='message' && $type1 == 'rfc822') {
 503             $default_page = sqm_baseuri() . 'src/read_body.php';
 504             $rfc822_header = $att->rfc822_header;
 505             $filename = $rfc822_header->subject;
 506             if (trim( $filename ) == '') {
 507                 $filename = 'untitled-[' . $ent . ']' ;
 508             }
 509             $from_o = $rfc822_header->from;
 510             if (is_object($from_o)) {
 511                 $from_name = decodeHeader($from_o->getAddress(false));
 512             } else {
 513                 $from_name = _("Unknown sender");
 514             }
 515             $description = $from_name;
 516         } else {
 517             $default_page = sqm_baseuri() . 'src/download.php';
 518             $filename = $att->getFilename();
 519             if ($header->description) {
 520                 $description = decodeHeader($header->description);
 521             } else {
 522                 $description = '';
 523             }
 524         }
 525
 526         $display_filename = $filename;
 527         if (isset($passed_ent_id)) {
 528             $passed_ent_id_link = '&amp;passed_ent_id='.$passed_ent_id;
 529         } else {
 530             $passed_ent_id_link = '';
 531         }
 532         $defaultlink = $default_page . "?startMessage=$startMessage"
 533             . "&amp;passed_id=$id&amp;mailbox=$urlMailbox"
 534             . '&amp;ent_id='.$ent.$passed_ent_id_link;
 535         if ($where && $what) {
 536             $defaultlink .= '&amp;where='. urlencode($where).'&amp;what='.urlencode($what);
 537         }
 538
 539         /* This executes the attachment hook with a specific MIME-type.
 540          * If that doesn't have results, it tries if there's a rule
 541          * for a more generic type.
 542          */
 543         $hookresults = do_hook("attachment $type0/$type1", $links,
 544                 $startMessage, $id, $urlMailbox, $ent, $defaultlink,
 545                 $display_filename, $where, $what);
 546         if(count($hookresults[1]) <= 1) {
 547             $hookresults = do_hook("attachment $type0/*", $links,
 548                     $startMessage, $id, $urlMailbox, $ent, $defaultlink,
 549                     $display_filename, $where, $what);
 550         }
 551
 552         $links = $hookresults[1];
 553         $defaultlink = $hookresults[6];
 554
 555         $attachments .= '<tr><td>' .
 556             '<a href="'.$defaultlink.'">'.decodeHeader($display_filename).'</a>&nbsp;</td>' .
 557             '<td><small><b>' . show_readable_size($header->size) .
 558             '</b>&nbsp;&nbsp;</small></td>' .
 559             '<td><small>[ '.htmlspecialchars($type0).'/'.htmlspecialchars($type1).' ]&nbsp;</small></td>' .
 560             '<td><small>';
 561         $attachments .= '<b>' . $description . '</b>';
 562         $attachments .= '</small></td><td><small>&nbsp;';
 563
 564         $skipspaces = 1;
 565         foreach ($links as $val) {
 566             if ($skipspaces) {
 567                 $skipspaces = 0;
 568             } else {
 569                 $attachments .= '&nbsp;&nbsp;|&nbsp;&nbsp;';
 570             }
 571             $attachments .= '<a href="' . $val['href'] . '">'
 572                 . (isset($val['text']) && !empty($val['text']) ? $val['text'] : '')
 573                 . (isset($val['extra']) && !empty($val['extra']) ? $val['extra'] : '')
 574                 . '</a>';
 575         }
 576         unset($links);
 577         $attachments .= "</td></tr>\n";
 578     }
 579     $attachmentadd = do_hook_function('attachments_bottom',$attachments);
 580     if ($attachmentadd != '')
 581         $attachments = $attachmentadd;
 582     return $attachments;
 583 }
 584
 585 function sqimap_base64_decode(&$string) {
 586
 587     // Base64 encoded data goes in pairs of 4 bytes. To achieve on the
 588     // fly decoding (to reduce memory usage) you have to check if the
 589     // data has incomplete pairs
 590
 591     // Remove the noise in order to check if the 4 bytes pairs are complete
 592     $string = str_replace(array("\r\n","\n", "\r", " "),array('','','',''),$string);
 593
 594     $sStringRem = '';
 595     $iMod = strlen($string) % 4;
 596     if ($iMod) {
 597         $sStringRem = substr($string,-$iMod);
 598         // Check if $sStringRem contains padding characters
 599         if (substr($sStringRem,-1) != '=') {
 600             $string = substr($string,0,-$iMod);
 601         } else {
 602             $sStringRem = '';
 603         }
 604     }
 605     $string = base64_decode($string);
 606     return $sStringRem;
 607 }
 608
 609
 610 /* This function decodes the body depending on the encoding type. */
 611 function decodeBody($body, $encoding) {
 612     global $show_html_default;
 613
 614     $body = str_replace("\r\n", "\n", $body);
 615     $encoding = strtolower($encoding);
 616
 617     $encoding_handler = do_hook_function('decode_body', $encoding);
 618
 619
 620     // plugins get first shot at decoding the body
 621     //
 622     if (!empty($encoding_handler) && function_exists($encoding_handler)) {
 623         $body = $encoding_handler('decode', $body);
 624
 625     } else if ($encoding == 'quoted-printable' ||
 626             $encoding == 'quoted_printable') {
 627         $body = quoted_printable_decode($body);
 628
 629         while (ereg("=\n", $body)) {
 630             $body = ereg_replace ("=\n", '', $body);
 631         }
 632
 633     } else if ($encoding == 'base64') {
 634         $body = base64_decode($body);
 635     }
 636
 637     // All other encodings are returned raw.
 638     return $body;
 639 }
 640
 641 /**
 642  * Decodes headers
 643  *
 644  * This functions decode strings that is encoded according to
 645  * RFC1522 (MIME Part Two: Message Header Extensions for Non-ASCII Text).
 646  * Patched by Christian Schmidt <christian@ostenfeld.dk>  23/03/2002
 647  *
 648  * @param string $string header string that has to be made readable
 649  * @param boolean $utfencode change message in order to be readable on user's charset. defaults to true
 650  * @param boolean $htmlsave preserve spaces and sanitize html special characters. defaults to true
 651  * @param boolean $decide decide if string can be utfencoded. defaults to false
 652  * @return string decoded header string
 653  */
 654 function decodeHeader ($string, $utfencode=true,$htmlsave=true,$decide=false) {
 655     global $languages, $squirrelmail_language,$default_charset;
 656     if (is_array($string)) {
 657         $string = implode("\n", $string);
 658     }
 659
 660     if (isset($languages[$squirrelmail_language]['XTRA_CODE']) &&
 661             function_exists($languages[$squirrelmail_language]['XTRA_CODE'] . '_decodeheader')) {
 662         $string = call_user_func($languages[$squirrelmail_language]['XTRA_CODE'] . '_decodeheader', $string);
 663         // Do we need to return at this point?
 664         // return $string;
 665     }
 666     $i = 0;
 667     $iLastMatch = -2;
 668     $encoded = true;
 669
 670     $aString = explode(' ',$string);
 671     $ret = '';
 672     foreach ($aString as $chunk) {
 673         if ($encoded && $chunk === '') {
 674             continue;
 675         } elseif ($chunk === '') {
 676             $ret .= ' ';
 677             continue;
 678         }
 679         $encoded = false;
 680         /* if encoded words are not separated by a linear-space-white we still catch them */
 681         $j = $i-1;
 682
 683         while ($match = preg_match('/^(.*)=\?([^?]*)\?(Q|B)\?([^?]*)\?=(.*)$/Ui',$chunk,$res)) {
 684             /* if the last chunk isn't an encoded string then put back the space, otherwise don't */
 685             if ($iLastMatch !== $j) {
 686                 if ($htmlsave) {
 687                     $ret .= '&#32;';
 688                 } else {
 689                     $ret .= ' ';
 690                 }
 691             }
 692             $iLastMatch = $i;
 693             $j = $i;
 694             if ($htmlsave) {
 695                 $ret .= htmlspecialchars($res[1]);
 696             } else {
 697                 $ret .= $res[1];
 698             }
 699             $encoding = ucfirst($res[3]);
 700
 701             /* decide about valid decoding */
 702             if ($decide && is_conversion_safe($res[2])) {
 703                 $utfencode=true;
 704                 $can_be_encoded=true;
 705             } else {
 706                 $can_be_encoded=false;
 707             }
 708             switch ($encoding)
 709             {
 710                 case 'B':
 711                     $replace = base64_decode($res[4]);
 712                     if ($utfencode) {
 713                         if ($can_be_encoded) {
 714                             /* convert string to different charset,
 715                              * if functions asks for it (usually in compose)
 716                              */
 717                             $ret .= charset_convert($res[2],$replace,$default_charset);
 718                         } else {
 719                             // convert string to html codes in order to display it
 720                             $ret .= charset_decode($res[2],$replace);
 721                         }
 722                     } else {
 723                         if ($htmlsave) {
 724                             $replace = htmlspecialchars($replace);
 725                         }
 726                         $ret.= $replace;
 727                     }
 728                     break;
 729                 case 'Q':
 730                     $replace = str_replace('_', ' ', $res[4]);
 731                     $replace = preg_replace('/=([0-9a-f]{2})/ie', 'chr(hexdec("\1"))',
 732                             $replace);
 733                     if ($utfencode) {
 734                         if ($can_be_encoded) {
 735                             /* convert string to different charset,
 736                              * if functions asks for it (usually in compose)
 737                              */
 738                             $replace = charset_convert($res[2], $replace,$default_charset);
 739                         } else {
 740                             // convert string to html codes in order to display it
 741                             $replace = charset_decode($res[2], $replace);
 742                         }
 743                     } else {
 744                         if ($htmlsave) {
 745                             $replace = htmlspecialchars($replace);
 746                         }
 747                     }
 748                     $ret .= $replace;
 749                     break;
 750                 default:
 751                     break;
 752             }
 753             $chunk = $res[5];
 754             $encoded = true;
 755         }
 756         if (!$encoded) {
 757             if ($htmlsave) {
 758                 $ret .= '&#32;';
 759             } else {
 760                 $ret .= ' ';
 761             }
 762         }
 763
 764         if (!$encoded && $htmlsave) {
 765             $ret .= htmlspecialchars($chunk);
 766         } else {
 767             $ret .= $chunk;
 768         }
 769         ++$i;
 770     }
 771     /* remove the first added space */
 772     if ($ret) {
 773         if ($htmlsave) {
 774             $ret = substr($ret,5);
 775         } else {
 776             $ret = substr($ret,1);
 777         }
 778     }
 779
 780     return $ret;
 781 }
 782
 783 /**
 784  * Encodes header
 785  *
 786  * Function uses XTRA_CODE _encodeheader function, if such function exists.
 787  *
 788  * mb_encode_mimeheader is used, if function is present, 50% or more bytes
 789  * are 8bit and multibyte character set is used.
 790  *
 791  * Function uses Q encoding by default and encodes a string according to RFC
 792  * 1522 for use in headers if it contains 8-bit characters or anything that
 793  * looks like it should be encoded.
 794  *
 795  * @param string $string header string, that has to be encoded
 796  * @return string quoted-printable encoded string
 797  */
 798 function encodeHeader ($string) {
 799     global $default_charset, $languages, $squirrelmail_language;
 800
 801     if (isset($languages[$squirrelmail_language]['XTRA_CODE']) &&
 802             function_exists($languages[$squirrelmail_language]['XTRA_CODE'] . '_encodeheader')) {
 803         return  call_user_func($languages[$squirrelmail_language]['XTRA_CODE'] . '_encodeheader', $string);
 804     }
 805
 806     // Use B encoding for multibyte charsets
 807     /*
 808     $mb_charsets = array('utf-8','big-5','gb2313','euc-kr');
 809     if (function_exists('mb_encode_mimeheader') &&
 810         in_array($default_charset,$mb_charsets) &&
 811         in_array($default_charset,sq_mb_list_encodings())) {
 812         return mb_encode_mimeheader($string,$default_charset,'B',"\r\n");
 813     }*/
 814
 815     // Encode only if the string contains 8-bit characters or =?
 816     $j = strlen($string);
 817     $max_l = 75 - strlen($default_charset) - 7;
 818     $aRet = array();
 819     $ret = '';
 820     $iEncStart = $enc_init = false;
 821     $cur_l = $iOffset = 0;
 822     for($i = 0; $i < $j; ++$i) {
 823         switch($string{$i})
 824         {
 825             case '=':
 826             case '<':
 827             case '>':
 828             case ',':
 829             case '?':
 830             case '_':
 831                 if ($iEncStart === false) {
 832                     $iEncStart = $i;
 833                 }
 834                 $cur_l+=3;
 835                 if ($cur_l > ($max_l-2)) {
 836                     /* if there is an stringpart that doesn't need encoding, add it */
 837                     $aRet[] = substr($string,$iOffset,$iEncStart-$iOffset);
 838                     $aRet[] = "=?$default_charset?Q?$ret?=";
 839                     $iOffset = $i;
 840                     $cur_l = 0;
 841                     $ret = '';
 842                     $iEncStart = false;
 843                 } else {
 844                     $ret .= sprintf("=%02X",ord($string{$i}));
 845                 }
 846                 break;
 847             case '(':
 848             case ')':
 849                 if ($iEncStart !== false) {
 850                     $aRet[] = substr($string,$iOffset,$iEncStart-$iOffset);
 851                     $aRet[] = "=?$default_charset?Q?$ret?=";
 852                     $iOffset = $i;
 853                     $cur_l = 0;
 854                     $ret = '';
 855                     $iEncStart = false;
 856                 }
 857                 break;
 858             case ' ':
 859                 if ($iEncStart !== false) {
 860                     $cur_l++;
 861                     if ($cur_l > $max_l) {
 862                         $aRet[] = substr($string,$iOffset,$iEncStart-$iOffset);
 863                         $aRet[] = "=?$default_charset?Q?$ret?=";
 864                         $iOffset = $i;
 865                         $cur_l = 0;
 866                         $ret = '';
 867                         $iEncStart = false;
 868                     } else {
 869                         $ret .= '_';
 870                     }
 871                 }
 872                 break;
 873             default:
 874                 $k = ord($string{$i});
 875                 if ($k > 126) {
 876                     if ($iEncStart === false) {
 877                         // do not start encoding in the middle of a string, also take the rest of the word.
 878                         $sLeadString = substr($string,0,$i);
 879                         $aLeadString = explode(' ',$sLeadString);
 880                         $sToBeEncoded = array_pop($aLeadString);
 881                         $iEncStart = $i - strlen($sToBeEncoded);
 882                         $ret .= $sToBeEncoded;
 883                         $cur_l += strlen($sToBeEncoded);
 884                     }
 885                     $cur_l += 3;
 886                     /* first we add the encoded string that reached it's max size */
 887                     if ($cur_l > ($max_l-2)) {
 888                         $aRet[] = substr($string,$iOffset,$iEncStart-$iOffset);
 889                         $aRet[] = "=?$default_charset?Q?$ret?= "; /* the next part is also encoded => separate by space */
 890                         $cur_l = 3;
 891                         $ret = '';
 892                         $iOffset = $i;
 893                         $iEncStart = $i;
 894                     }
 895                     $enc_init = true;
 896                     $ret .= sprintf("=%02X", $k);
 897                 } else {
 898                     if ($iEncStart !== false) {
 899                         $cur_l++;
 900                         if ($cur_l > $max_l) {
 901                             $aRet[] = substr($string,$iOffset,$iEncStart-$iOffset);
 902                             $aRet[] = "=?$default_charset?Q?$ret?=";
 903                             $iEncStart = false;
 904                             $iOffset = $i;
 905                             $cur_l = 0;
 906                             $ret = '';
 907                         } else {
 908                             $ret .= $string{$i};
 909                         }
 910                     }
 911                 }
 912                 break;
 913         }
 914     }
 915
 916     if ($enc_init) {
 917         if ($iEncStart !== false) {
 918             $aRet[] = substr($string,$iOffset,$iEncStart-$iOffset);
 919             $aRet[] = "=?$default_charset?Q?$ret?=";
 920         } else {
 921             $aRet[] = substr($string,$iOffset);
 922         }
 923         $string = implode('',$aRet);
 924     }
 925     return $string;
 926 }
 927
 928 /* This function trys to locate the entity_id of a specific mime element */
 929 function find_ent_id($id, $message) {
 930     for ($i = 0, $ret = ''; $ret == '' && $i < count($message->entities); $i++) {
 931         if ($message->entities[$i]->header->type0 == 'multipart')  {
 932             $ret = find_ent_id($id, $message->entities[$i]);
 933         } else {
 934             if (strcasecmp($message->entities[$i]->header->id, $id) == 0) {
 935 //                if (sq_check_save_extension($message->entities[$i])) {
 936                 return $message->entities[$i]->entity_id;
 937 //                }
 938             } elseif (!empty($message->entities[$i]->header->parameters['name'])) {
 939                 /**
 940                  * This is part of a fix for Outlook Express 6.x generating
 941                  * cid URLs without creating content-id headers
 942                  * @@JA - 20050207
 943                  */
 944                 if (strcasecmp($message->entities[$i]->header->parameters['name'], $id) == 0) {
 945                     return $message->entities[$i]->entity_id;
 946                 }
 947             }
 948         }
 949     }
 950     return $ret;
 951 }
 952
 953 function sq_check_save_extension($message) {
 954     $filename = $message->getFilename();
 955     $ext = substr($filename, strrpos($filename,'.')+1);
 956     $save_extensions = array('jpg','jpeg','gif','png','bmp');
 957     return in_array($ext, $save_extensions);
 958 }
 959
 960
 961 /**
 962  ** HTMLFILTER ROUTINES
 963  */
 964
 965 /**
 966  * This function checks attribute values for entity-encoded values
 967  * and returns them translated into 8-bit strings so we can run
 968  * checks on them.
 969  *
 970  * @param  $attvalue A string to run entity check against.
 971  * @return           Nothing, modifies a reference value.
 972  */
 973 function sq_defang(&$attvalue){
 974     $me = 'sq_defang';
 975     /**
 976      * Skip this if there aren't ampersands or backslashes.
 977      */
 978     if (strpos($attvalue, '&') === false
 979         && strpos($attvalue, '\\') === false){
 980         return;
 981     }
 982     $m = false;
 983     do {
 984         $m = false;
 985         $m = $m || sq_deent($attvalue, '/\&#0*(\d+);*/s');
 986         $m = $m || sq_deent($attvalue, '/\&#x0*((\d|[a-f])+);*/si', true);
 987         $m = $m || sq_deent($attvalue, '/\\\\(\d+)/s', true);
 988     } while ($m == true);
 989     $attvalue = stripslashes($attvalue);
 990 }
 991
 992 /**
 993  * Kill any tabs, newlines, or carriage returns. Our friends the
 994  * makers of the browser with 95% market value decided that it'd
 995  * be funny to make "java[tab]script" be just as good as "javascript".
 996  *
 997  * @param  attvalue  The attribute value before extraneous spaces removed.
 998  * @return attvalue  Nothing, modifies a reference value.
 999  */
1000 function sq_unspace(&$attvalue){
1001     $me = 'sq_unspace';
1002     if (strcspn($attvalue, "\t\r\n\0 ") != strlen($attvalue)){
1003         $attvalue = str_replace(Array("\t", "\r", "\n", "\0", " "),
1004                                 Array('',   '',   '',   '',   ''), $attvalue);
1005     }
1006 }
1007
1008 /**
1009  * This function returns the final tag out of the tag name, an array
1010  * of attributes, and the type of the tag. This function is called by
1011  * sq_sanitize internally.
1012  *
1013  * @param  $tagname  the name of the tag.
1014  * @param  $attary   the array of attributes and their values
1015  * @param  $tagtype  The type of the tag (see in comments).
1016  * @return           a string with the final tag representation.
1017  */
1018 function sq_tagprint($tagname, $attary, $tagtype){
1019     $me = 'sq_tagprint';
1020
1021     if ($tagtype == 2){
1022         $fulltag = '</' . $tagname . '>';
1023     } else {
1024         $fulltag = '<' . $tagname;
1025         if (is_array($attary) && sizeof($attary)){
1026             $atts = Array();
1027             while (list($attname, $attvalue) = each($attary)){
1028                 array_push($atts, "$attname=$attvalue");
1029             }
1030             $fulltag .= ' ' . join(" ", $atts);
1031         }
1032         if ($tagtype == 3){
1033             $fulltag .= ' /';
1034         }
1035         $fulltag .= '>';
1036     }
1037     return $fulltag;
1038 }
1039
1040 /**
1041  * A small helper function to use with array_walk. Modifies a by-ref
1042  * value and makes it lowercase.
1043  *
1044  * @param  $val a value passed by-ref.
1045  * @return      void since it modifies a by-ref value.
1046  */
1047 function sq_casenormalize(&$val){
1048     $val = strtolower($val);
1049 }
1050
1051 /**
1052  * This function skips any whitespace from the current position within
1053  * a string and to the next non-whitespace value.
1054  *
1055  * @param  $body   the string
1056  * @param  $offset the offset within the string where we should start
1057  *                 looking for the next non-whitespace character.
1058  * @return         the location within the $body where the next
1059  *                 non-whitespace char is located.
1060  */
1061 function sq_skipspace($body, $offset){
1062     $me = 'sq_skipspace';
1063     preg_match('/^(\s*)/s', substr($body, $offset), $matches);
1064     if (sizeof($matches{1})){
1065         $count = strlen($matches{1});
1066         $offset += $count;
1067     }
1068     return $offset;
1069 }
1070
1071 /**
1072  * This function looks for the next character within a string.  It's
1073  * really just a glorified "strpos", except it catches if failures
1074  * nicely.
1075  *
1076  * @param  $body   The string to look for needle in.
1077  * @param  $offset Start looking from this position.
1078  * @param  $needle The character/string to look for.
1079  * @return         location of the next occurance of the needle, or
1080  *                 strlen($body) if needle wasn't found.
1081  */
1082 function sq_findnxstr($body, $offset, $needle){
1083     $me  = 'sq_findnxstr';
1084     $pos = strpos($body, $needle, $offset);
1085     if ($pos === FALSE){
1086         $pos = strlen($body);
1087     }
1088     return $pos;
1089 }
1090
1091 /**
1092  * This function takes a PCRE-style regexp and tries to match it
1093  * within the string.
1094  *
1095  * @param  $body   The string to look for needle in.
1096  * @param  $offset Start looking from here.
1097  * @param  $reg    A PCRE-style regex to match.
1098  * @return         Returns a false if no matches found, or an array
1099  *                 with the following members:
1100  *                 - integer with the location of the match within $body
1101  *                 - string with whatever content between offset and the match
1102  *                 - string with whatever it is we matched
1103  */
1104 function sq_findnxreg($body, $offset, $reg){
1105     $me = 'sq_findnxreg';
1106     $matches = Array();
1107     $retarr = Array();
1108     preg_match("%^(.*?)($reg)%si", substr($body, $offset), $matches);
1109     if (!isset($matches{0}) || !$matches{0}){
1110         $retarr = false;
1111     } else {
1112         $retarr{0} = $offset + strlen($matches{1});
1113         $retarr{1} = $matches{1};
1114         $retarr{2} = $matches{2};
1115     }
1116     return $retarr;
1117 }
1118
1119 /**
1120  * This function looks for the next tag.
1121  *
1122  * @param  $body   String where to look for the next tag.
1123  * @param  $offset Start looking from here.
1124  * @return         false if no more tags exist in the body, or
1125  *                 an array with the following members:
1126  *                 - string with the name of the tag
1127  *                 - array with attributes and their values
1128  *                 - integer with tag type (1, 2, or 3)
1129  *                 - integer where the tag starts (starting "<")
1130  *                 - integer where the tag ends (ending ">")
1131  *                 first three members will be false, if the tag is invalid.
1132  */
1133 function sq_getnxtag($body, $offset){
1134     $me = 'sq_getnxtag';
1135     if ($offset > strlen($body)){
1136         return false;
1137     }
1138     $lt = sq_findnxstr($body, $offset, "<");
1139     if ($lt == strlen($body)){
1140         return false;
1141     }
1142     /**
1143      * We are here:
1144      * blah blah <tag attribute="value">
1145      * \---------^
1146      */
1147     $pos = sq_skipspace($body, $lt+1);
1148     if ($pos >= strlen($body)){
1149         return Array(false, false, false, $lt, strlen($body));
1150     }
1151     /**
1152      * There are 3 kinds of tags:
1153      * 1. Opening tag, e.g.:
1154      *    <a href="blah">
1155      * 2. Closing tag, e.g.:
1156      *    </a>
1157      * 3. XHTML-style content-less tag, e.g.:
1158      *    <img src="blah" />
1159      */
1160     $tagtype = false;
1161     switch (substr($body, $pos, 1)){
1162         case '/':
1163             $tagtype = 2;
1164             $pos++;
1165             break;
1166         case '!':
1167             /**
1168              * A comment or an SGML declaration.
1169              */
1170             if (substr($body, $pos+1, 2) == "--"){
1171                 $gt = strpos($body, "-->", $pos);
1172                 if ($gt === false){
1173                     $gt = strlen($body);
1174                 } else {
1175                     $gt += 2;
1176                 }
1177                 return Array(false, false, false, $lt, $gt);
1178             } else {
1179                 $gt = sq_findnxstr($body, $pos, ">");
1180                 return Array(false, false, false, $lt, $gt);
1181             }
1182             break;
1183         default:
1184             /**
1185              * Assume tagtype 1 for now. If it's type 3, we'll switch values
1186              * later.
1187              */
1188             $tagtype = 1;
1189             break;
1190     }
1191
1192     $tag_start = $pos;
1193     $tagname = '';
1194     /**
1195      * Look for next [\W-_], which will indicate the end of the tag name.
1196      */
1197     $regary = sq_findnxreg($body, $pos, "[^\w\-_]");
1198     if ($regary == false){
1199         return Array(false, false, false, $lt, strlen($body));
1200     }
1201     list($pos, $tagname, $match) = $regary;
1202     $tagname = strtolower($tagname);
1203
1204     /**
1205      * $match can be either of these:
1206      * '>'  indicating the end of the tag entirely.
1207      * '\s' indicating the end of the tag name.
1208      * '/'  indicating that this is type-3 xhtml tag.
1209      *
1210      * Whatever else we find there indicates an invalid tag.
1211      */
1212     switch ($match){
1213         case '/':
1214             /**
1215              * This is an xhtml-style tag with a closing / at the
1216              * end, like so: <img src="blah" />. Check if it's followed
1217              * by the closing bracket. If not, then this tag is invalid
1218              */
1219             if (substr($body, $pos, 2) == "/>"){
1220                 $pos++;
1221                 $tagtype = 3;
1222             } else {
1223                 $gt = sq_findnxstr($body, $pos, ">");
1224                 $retary = Array(false, false, false, $lt, $gt);
1225                 return $retary;
1226             }
1227         case '>':
1228             return Array($tagname, false, $tagtype, $lt, $pos);
1229             break;
1230         default:
1231             /**
1232              * Check if it's whitespace
1233              */
1234             if (!preg_match('/\s/', $match)){
1235                 /**
1236                  * This is an invalid tag! Look for the next closing ">".
1237                  */
1238                 $gt = sq_findnxstr($body, $lt, ">");
1239                 return Array(false, false, false, $lt, $gt);
1240             }
1241             break;
1242     }
1243
1244     /**
1245      * At this point we're here:
1246      * <tagname  attribute='blah'>
1247      * \-------^
1248      *
1249      * At this point we loop in order to find all attributes.
1250      */
1251     $attname = '';
1252     $atttype = false;
1253     $attary = Array();
1254
1255     while ($pos <= strlen($body)){
1256         $pos = sq_skipspace($body, $pos);
1257         if ($pos == strlen($body)){
1258             /**
1259              * Non-closed tag.
1260              */
1261             return Array(false, false, false, $lt, $pos);
1262         }
1263         /**
1264          * See if we arrived at a ">" or "/>", which means that we reached
1265          * the end of the tag.
1266          */
1267         $matches = Array();
1268         if (preg_match("%^(\s*)(>|/>)%s", substr($body, $pos), $matches)) {
1269             /**
1270              * Yep. So we did.
1271              */
1272             $pos += strlen($matches{1});
1273             if ($matches{2} == "/>"){
1274                 $tagtype = 3;
1275                 $pos++;
1276             }
1277             return Array($tagname, $attary, $tagtype, $lt, $pos);
1278         }
1279
1280         /**
1281          * There are several types of attributes, with optional
1282          * [:space:] between members.
1283          * Type 1:
1284          *   attrname[:space:]=[:space:]'CDATA'
1285          * Type 2:
1286          *   attrname[:space:]=[:space:]"CDATA"
1287          * Type 3:
1288          *   attr[:space:]=[:space:]CDATA
1289          * Type 4:
1290          *   attrname
1291          *
1292          * We leave types 1 and 2 the same, type 3 we check for
1293          * '"' and convert to "&quot" if needed, then wrap in
1294          * double quotes. Type 4 we convert into:
1295          * attrname="yes".
1296          */
1297         $regary = sq_findnxreg($body, $pos, "[^:\w\-_]");
1298         if ($regary == false){
1299             /**
1300              * Looks like body ended before the end of tag.
1301              */
1302             return Array(false, false, false, $lt, strlen($body));
1303         }
1304         list($pos, $attname, $match) = $regary;
1305         $attname = strtolower($attname);
1306         /**
1307          * We arrived at the end of attribute name. Several things possible
1308          * here:
1309          * '>'  means the end of the tag and this is attribute type 4
1310          * '/'  if followed by '>' means the same thing as above
1311          * '\s' means a lot of things -- look what it's followed by.
1312          *      anything else means the attribute is invalid.
1313          */
1314         switch($match){
1315             case '/':
1316                 /**
1317                  * This is an xhtml-style tag with a closing / at the
1318                  * end, like so: <img src="blah" />. Check if it's followed
1319                  * by the closing bracket. If not, then this tag is invalid
1320                  */
1321                 if (substr($body, $pos, 2) == "/>"){
1322                     $pos++;
1323                     $tagtype = 3;
1324                 } else {
1325                     $gt = sq_findnxstr($body, $pos, ">");
1326                     $retary = Array(false, false, false, $lt, $gt);
1327                     return $retary;
1328                 }
1329             case '>':
1330                 $attary{$attname} = '"yes"';
1331                 return Array($tagname, $attary, $tagtype, $lt, $pos);
1332                 break;
1333             default:
1334                 /**
1335                  * Skip whitespace and see what we arrive at.
1336                  */
1337                 $pos = sq_skipspace($body, $pos);
1338                 $char = substr($body, $pos, 1);
1339                 /**
1340                  * Two things are valid here:
1341                  * '=' means this is attribute type 1 2 or 3.
1342                  * \w means this was attribute type 4.
1343                  * anything else we ignore and re-loop. End of tag and
1344                  * invalid stuff will be caught by our checks at the beginning
1345                  * of the loop.
1346                  */
1347                 if ($char == "="){
1348                     $pos++;
1349                     $pos = sq_skipspace($body, $pos);
1350                     /**
1351                      * Here are 3 possibilities:
1352                      * "'"  attribute type 1
1353                      * '"'  attribute type 2
1354                      * everything else is the content of tag type 3
1355                      */
1356                     $quot = substr($body, $pos, 1);
1357                     if ($quot == "'"){
1358                         $regary = sq_findnxreg($body, $pos+1, "\'");
1359                         if ($regary == false){
1360                             return Array(false, false, false, $lt, strlen($body));
1361                         }
1362                         list($pos, $attval, $match) = $regary;
1363                         $pos++;
1364                         $attary{$attname} = "'" . $attval . "'";
1365                     } else if ($quot == '"'){
1366                         $regary = sq_findnxreg($body, $pos+1, '\"');
1367                         if ($regary == false){
1368                             return Array(false, false, false, $lt, strlen($body));
1369                         }
1370                         list($pos, $attval, $match) = $regary;
1371                         $pos++;
1372                         $attary{$attname} = '"' . $attval . '"';
1373                     } else {
1374                         /**
1375                          * These are hateful. Look for \s, or >.
1376                          */
1377                         $regary = sq_findnxreg($body, $pos, "[\s>]");
1378                         if ($regary == false){
1379                             return Array(false, false, false, $lt, strlen($body));
1380                         }
1381                         list($pos, $attval, $match) = $regary;
1382                         /**
1383                          * If it's ">" it will be caught at the top.
1384                          */
1385                         $attval = preg_replace("/\"/s", "&quot;", $attval);
1386                         $attary{$attname} = '"' . $attval . '"';
1387                     }
1388                 } else if (preg_match("|[\w/>]|", $char)) {
1389                     /**
1390                      * That was attribute type 4.
1391                      */
1392                     $attary{$attname} = '"yes"';
1393                 } else {
1394                     /**
1395                      * An illegal character. Find next '>' and return.
1396                      */
1397                     $gt = sq_findnxstr($body, $pos, ">");
1398                     return Array(false, false, false, $lt, $gt);
1399                 }
1400                 break;
1401         }
1402     }
1403     /**
1404      * The fact that we got here indicates that the tag end was never
1405      * found. Return invalid tag indication so it gets stripped.
1406      */
1407     return Array(false, false, false, $lt, strlen($body));
1408 }
1409
1410 /**
1411  * Translates entities into literal values so they can be checked.
1412  *
1413  * @param $attvalue the by-ref value to check.
1414  * @param $regex    the regular expression to check against.
1415  * @param $hex      whether the entites are hexadecimal.
1416  * @return          True or False depending on whether there were matches.
1417  */
1418 function sq_deent(&$attvalue, $regex, $hex=false){
1419     $me = 'sq_deent';
1420     $ret_match = false;
1421     preg_match_all($regex, $attvalue, $matches);
1422     if (is_array($matches) && sizeof($matches[0]) > 0){
1423         $repl = Array();
1424         for ($i = 0; $i < sizeof($matches[0]); $i++){
1425             $numval = $matches[1][$i];
1426             if ($hex){
1427                 $numval = hexdec($numval);
1428             }
1429             $repl{$matches[0][$i]} = chr($numval);
1430         }
1431         $attvalue = strtr($attvalue, $repl);
1432         return true;
1433     } else {
1434         return false;
1435     }
1436 }
1437
1438 /**
1439  * This function runs various checks against the attributes.
1440  *
1441  * @param  $tagname         String with the name of the tag.
1442  * @param  $attary          Array with all tag attributes.
1443  * @param  $rm_attnames     See description for sq_sanitize
1444  * @param  $bad_attvals     See description for sq_sanitize
1445  * @param  $add_attr_to_tag See description for sq_sanitize
1446  * @param  $message         message object
1447  * @param  $id              message id
1448  * @return                  Array with modified attributes.
1449  */
1450 function sq_fixatts($tagname,
1451                     $attary,
1452                     $rm_attnames,
1453                     $bad_attvals,
1454                     $add_attr_to_tag,
1455                     $message,
1456                     $id,
1457                     $mailbox
1458                     ){
1459     $me = 'sq_fixatts';
1460     while (list($attname, $attvalue) = each($attary)){
1461         /**
1462          * See if this attribute should be removed.
1463          */
1464         foreach ($rm_attnames as $matchtag=>$matchattrs){
1465             if (preg_match($matchtag, $tagname)){
1466                 foreach ($matchattrs as $matchattr){
1467                     if (preg_match($matchattr, $attname)){
1468                         unset($attary{$attname});
1469                         continue;
1470                     }
1471                 }
1472             }
1473         }
1474         /**
1475          * Remove any backslashes, entities, and extraneous whitespace.
1476          */
1477         sq_defang($attvalue);
1478         sq_unspace($attvalue);
1479
1480         /**
1481          * Now let's run checks on the attvalues.
1482          * I don't expect anyone to comprehend this. If you do,
1483          * get in touch with me so I can drive to where you live and
1484          * shake your hand personally. :)
1485          */
1486         foreach ($bad_attvals as $matchtag=>$matchattrs){
1487             if (preg_match($matchtag, $tagname)){
1488                 foreach ($matchattrs as $matchattr=>$valary){
1489                     if (preg_match($matchattr, $attname)){
1490                         /**
1491                          * There are two arrays in valary.
1492                          * First is matches.
1493                          * Second one is replacements
1494                          */
1495                         list($valmatch, $valrepl) = $valary;
1496                         $newvalue =
1497                             preg_replace($valmatch, $valrepl, $attvalue);
1498                         if ($newvalue != $attvalue){
1499                             $attary{$attname} = $newvalue;
1500                         }
1501                     }
1502                 }
1503             }
1504         }
1505
1506         /**
1507          * Replace empty src tags with the blank image.  src is only used
1508          * for frames, images, and image inputs.  Doing a replace should
1509          * not affect them working as should be, however it will stop
1510          * IE from being kicked off when src for img tags are not set
1511          */
1512         if (($attname == 'src') && ($attvalue == '""')) {
1513             $attary{$attname} = '"' . SM_PATH . 'images/blank.png"';
1514         }
1515
1516         /**
1517          * Turn cid: urls into http-friendly ones.
1518          */
1519         if (preg_match("/^[\'\"]\s*cid:/si", $attvalue)){
1520             $attary{$attname} = sq_cid2http($message, $id, $attvalue, $mailbox);
1521         }
1522
1523         /**
1524          * "Hack" fix for Outlook using propriatary outbind:// protocol in img tags.
1525          * One day MS might actually make it match something useful, for now, falling
1526          * back to using cid2http, so we can grab the blank.png.
1527          */
1528         if (preg_match("/^[\'\"]\s*outbind:\/\//si", $attvalue)) {
1529             $attary{$attname} = sq_cid2http($message, $id, $attvalue, $mailbox);
1530         }
1531
1532     }
1533     /**
1534      * See if we need to append any attributes to this tag.
1535      */
1536     foreach ($add_attr_to_tag as $matchtag=>$addattary){
1537         if (preg_match($matchtag, $tagname)){
1538             $attary = array_merge($attary, $addattary);
1539         }
1540     }
1541     return $attary;
1542 }
1543
1544 /**
1545  * This function edits the style definition to make them friendly and
1546  * usable in SquirrelMail.
1547  *
1548  * @param  $message  the message object
1549  * @param  $id       the message id
1550  * @param  $content  a string with whatever is between <style> and </style>
1551  * @param  $mailbox  the message mailbox
1552  * @return           a string with edited content.
1553  */
1554 function sq_fixstyle($body, $pos, $message, $id, $mailbox){
1555     global $view_unsafe_images;
1556     $me = 'sq_fixstyle';
1557     $ret = sq_findnxreg($body, $pos, '</\s*style\s*>');
1558     if ($ret == FALSE){
1559         return array(FALSE, strlen($body));
1560     }
1561     $newpos = $ret[0] + strlen($ret[2]);
1562     $content = $ret[1];
1563     /**
1564     * First look for general BODY style declaration, which would be
1565     * like so:
1566     * body {background: blah-blah}
1567     * and change it to .bodyclass so we can just assign it to a <div>
1568     */
1569     $content = preg_replace("|body(\s*\{.*?\})|si", ".bodyclass\\1", $content);
1570     $secremoveimg = '../images/' . _("sec_remove_eng.png");
1571     /**
1572     * Fix url('blah') declarations.
1573     */
1574     //   $content = preg_replace("|url\s*\(\s*([\'\"])\s*\S+script\s*:.*?([\'\"])\s*\)|si",
1575     //                           "url(\\1$secremoveimg\\2)", $content);
1576     // remove NUL
1577     $content = str_replace("\0", "", $content);
1578     // NB I insert NUL characters to keep to avoid an infinite loop. They are removed after the loop.
1579     while (preg_match("/url\s*\(\s*[\'\"]?([^:]+):(.*)?[\'\"]?\s*\)/si", $content, $matches)) {
1580         $sProto = strtolower($matches[1]);
1581         switch ($sProto) {
1582           /**
1583            * Fix url('https*://.*) declarations but only if $view_unsafe_images
1584            * is false.
1585            */
1586           case 'https':
1587           case 'http':
1588             if (!$view_unsafe_images){
1589                 $sExpr = "/url\s*\(\s*([\'\"])\s*$sProto*:.*?([\'\"])\s*\)/si";
1590                 $content = preg_replace($sExpr, "u\0r\0l(\\1$secremoveimg\\2)", $content);
1591             }
1592             break;
1593           /**
1594            * Fix urls that refer to cid:
1595            */
1596           case 'cid':
1597             $cidurl = 'cid:'. $matches[2];
1598             $httpurl = sq_cid2http($message, $id, $cidurl, $mailbox);
1599             $content = preg_replace("|url\s*\(\s*$cidurl\s*\)|si",
1600                                 "u\0r\0l($httpurl)", $content);
1601             break;
1602           default:
1603             /**
1604              * replace url with protocol other then the white list
1605              * http,https and cid by an empty string.
1606              */
1607             $content = preg_replace("/url\s*\(\s*[\'\"]?([^:]+):(.*)?[\'\"]?\s*\)/si",
1608                                 "", $content);
1609             break;
1610         }
1611         break;
1612     }
1613     // remove NUL
1614     $content = str_replace("\0", "", $content);
1615
1616    /**
1617     * Remove any backslashes, entities, and extraneous whitespace.
1618     */
1619     $contentTemp = $content;
1620     sq_defang($contentTemp);
1621     sq_unspace($contentTemp);
1622
1623     /**
1624      * Fix stupid css declarations which lead to vulnerabilities
1625      * in IE.
1626      */
1627     $match   = Array('/expression/i',
1628                     '/behaviou*r/i',
1629                     '/binding/i',
1630                     '/include-source/i');
1631     $replace = Array('idiocy', 'idiocy', 'idiocy', 'idiocy');
1632     $contentNew = preg_replace($match, $replace, $contentTemp);
1633     if ($contentNew !== $contentTemp) {
1634         // insecure css declarations are used. From now on we don't care
1635         // anymore if the css is destroyed by sq_deent, sq_unspace or sq_unbackslash
1636         $content = $contentNew;
1637     }
1638     return array($content, $newpos);
1639 }
1640
1641
1642 /**
1643  * This function converts cid: url's into the ones that can be viewed in
1644  * the browser.
1645  *
1646  * @param  $message  the message object
1647  * @param  $id       the message id
1648  * @param  $cidurl   the cid: url.
1649  * @param  $mailbox  the message mailbox
1650  * @return           a string with a http-friendly url
1651  */
1652 function sq_cid2http($message, $id, $cidurl, $mailbox){
1653     /**
1654      * Get rid of quotes.
1655      */
1656     $quotchar = substr($cidurl, 0, 1);
1657     if ($quotchar == '"' || $quotchar == "'"){
1658         $cidurl = str_replace($quotchar, "", $cidurl);
1659     } else {
1660         $quotchar = '';
1661     }
1662     $cidurl = substr(trim($cidurl), 4);
1663
1664     $match_str = '/\{.*?\}\//';
1665     $str_rep = '';
1666     $cidurl = preg_replace($match_str, $str_rep, $cidurl);
1667
1668     $linkurl = find_ent_id($cidurl, $message);
1669     /* in case of non-save cid links $httpurl should be replaced by a sort of
1670        unsave link image */
1671     $httpurl = '';
1672
1673     /**
1674      * This is part of a fix for Outlook Express 6.x generating
1675      * cid URLs without creating content-id headers. These images are
1676      * not part of the multipart/related html mail. The html contains
1677      * <img src="cid:{some_id}/image_filename.ext"> references to
1678      * attached images with as goal to render them inline although
1679      * the attachment disposition property is not inline.
1680      */
1681
1682     if (empty($linkurl)) {
1683         if (preg_match('/{.*}\//', $cidurl)) {
1684             $cidurl = preg_replace('/{.*}\//','', $cidurl);
1685             if (!empty($cidurl)) {
1686                 $linkurl = find_ent_id($cidurl, $message);
1687             }
1688         }
1689     }
1690
1691     if (!empty($linkurl)) {
1692         $httpurl = $quotchar . SM_PATH . 'src/download.php?absolute_dl=true&amp;' .
1693             "passed_id=$id&amp;mailbox=" . urlencode($mailbox) .
1694             '&amp;ent_id=' . $linkurl . $quotchar;
1695     } else {
1696         /**
1697          * If we couldn't generate a proper img url, drop in a blank image
1698          * instead of sending back empty, otherwise it causes unusual behaviour
1699          */
1700         $httpurl = $quotchar . SM_PATH . 'images/blank.png' . $quotchar;
1701     }
1702
1703     return $httpurl;
1704 }
1705
1706 /**
1707  * This function changes the <body> tag into a <div> tag since we
1708  * can't really have a body-within-body.
1709  *
1710  * @param  $attary   an array of attributes and values of <body>
1711  * @param  $mailbox  mailbox we're currently reading (for cid2http)
1712  * @param  $message  current message (for cid2http)
1713  * @param  $id       current message id (for cid2http)
1714  * @return           a modified array of attributes to be set for <div>
1715  */
1716 function sq_body2div($attary, $mailbox, $message, $id){
1717     $me = 'sq_body2div';
1718     $divattary = Array('class' => "'bodyclass'");
1719     $text = '#000000';
1720     $has_bgc_stl = $has_txt_stl = false;
1721     $styledef = '';
1722     if (is_array($attary) && sizeof($attary) > 0){
1723         foreach ($attary as $attname=>$attvalue){
1724             $quotchar = substr($attvalue, 0, 1);
1725             $attvalue = str_replace($quotchar, "", $attvalue);
1726             switch ($attname){
1727                 case 'background':
1728                     $attvalue = sq_cid2http($message, $id, $attvalue, $mailbox);
1729                     $styledef .= "background-image: url('$attvalue'); ";
1730                     break;
1731                 case 'bgcolor':
1732                     $has_bgc_stl = true;
1733                     $styledef .= "background-color: $attvalue; ";
1734                     break;
1735                 case 'text':
1736                     $has_txt_stl = true;
1737                     $styledef .= "color: $attvalue; ";
1738                     break;
1739             }
1740         }
1741         // Outlook defines a white bgcolor and no text color. This can lead to
1742         // white text on a white bg with certain themes.
1743         if ($has_bgc_stl && !$has_txt_stl) {
1744             $styledef .= "color: $text; ";
1745         }
1746         if (strlen($styledef) > 0){
1747             $divattary{"style"} = "\"$styledef\"";
1748         }
1749     }
1750     return $divattary;
1751 }
1752
1753 /**
1754  * This is the main function and the one you should actually be calling.
1755  * There are several variables you should be aware of an which need
1756  * special description.
1757  *
1758  * Since the description is quite lengthy, see it here:
1759  * http://linux.duke.edu/projects/mini/htmlfilter/
1760  *
1761  * @param $body                 the string with HTML you wish to filter
1762  * @param $tag_list             see description above
1763  * @param $rm_tags_with_content see description above
1764  * @param $self_closing_tags    see description above
1765  * @param $force_tag_closing    see description above
1766  * @param $rm_attnames          see description above
1767  * @param $bad_attvals          see description above
1768  * @param $add_attr_to_tag      see description above
1769  * @param $message              message object
1770  * @param $id                   message id
1771  * @return                      sanitized html safe to show on your pages.
1772  */
1773 function sq_sanitize($body,
1774                      $tag_list,
1775                      $rm_tags_with_content,
1776                      $self_closing_tags,
1777                      $force_tag_closing,
1778                      $rm_attnames,
1779                      $bad_attvals,
1780                      $add_attr_to_tag,
1781                      $message,
1782                      $id,
1783                      $mailbox
1784                      ){
1785     $me = 'sq_sanitize';
1786     $rm_tags = array_shift($tag_list);
1787     /**
1788      * Normalize rm_tags and rm_tags_with_content.
1789      */
1790     @array_walk($tag_list, 'sq_casenormalize');
1791     @array_walk($rm_tags_with_content, 'sq_casenormalize');
1792     @array_walk($self_closing_tags, 'sq_casenormalize');
1793     /**
1794      * See if tag_list is of tags to remove or tags to allow.
1795      * false  means remove these tags
1796      * true   means allow these tags
1797      */
1798     $curpos = 0;
1799     $open_tags = Array();
1800     $trusted = "\n<!-- begin sanitized html -->\n";
1801     $skip_content = false;
1802     /**
1803      * Take care of netscape's stupid javascript entities like
1804      * &{alert('boo')};
1805      */
1806     $body = preg_replace("/&(\{.*?\};)/si", "&amp;\\1", $body);
1807
1808     while (($curtag = sq_getnxtag($body, $curpos)) != FALSE){
1809         list($tagname, $attary, $tagtype, $lt, $gt) = $curtag;
1810         $free_content = substr($body, $curpos, $lt-$curpos);
1811         /**
1812          * Take care of <style>
1813          */
1814         if ($tagname == "style" && $tagtype == 1){
1815             list($free_content, $curpos) =
1816                 sq_fixstyle($body, $gt+1, $message, $id, $mailbox);
1817             if ($free_content != FALSE){
1818                 $trusted .= sq_tagprint($tagname, $attary, $tagtype);
1819                 $trusted .= $free_content;
1820                 $trusted .= sq_tagprint($tagname, false, 2);
1821             }
1822             continue;
1823         }
1824         if ($skip_content == false){
1825             $trusted .= $free_content;
1826         }
1827         if ($tagname != FALSE){
1828             if ($tagtype == 2){
1829                 if ($skip_content == $tagname){
1830                     /**
1831                      * Got to the end of tag we needed to remove.
1832                      */
1833                     $tagname = false;
1834                     $skip_content = false;
1835                 } else {
1836                     if ($skip_content == false){
1837                         if ($tagname == "body"){
1838                             $tagname = "div";
1839                         }
1840                         if (isset($open_tags{$tagname}) &&
1841                                 $open_tags{$tagname} > 0){
1842                             $open_tags{$tagname}--;
1843                         } else {
1844                             $tagname = false;
1845                         }
1846                     }
1847                 }
1848             } else {
1849                 /**
1850                  * $rm_tags_with_content
1851                  */
1852                 if ($skip_content == false){
1853                     /**
1854                      * See if this is a self-closing type and change
1855                      * tagtype appropriately.
1856                      */
1857                     if ($tagtype == 1
1858                             && in_array($tagname, $self_closing_tags)){
1859                         $tagtype = 3;
1860                     }
1861                     /**
1862                      * See if we should skip this tag and any content
1863                      * inside it.
1864                      */
1865                     if ($tagtype == 1 &&
1866                             in_array($tagname, $rm_tags_with_content)){
1867                         $skip_content = $tagname;
1868                     } else {
1869                         if (($rm_tags == false
1870                                     && in_array($tagname, $tag_list)) ||
1871                                 ($rm_tags == true &&
1872                                  !in_array($tagname, $tag_list))){
1873                             $tagname = false;
1874                         } else {
1875                             /**
1876                              * Convert body into div.
1877                              */
1878                             if ($tagname == "body"){
1879                                 $tagname = "div";
1880                                 $attary = sq_body2div($attary, $mailbox,
1881                                         $message, $id);
1882                             }
1883                             if ($tagtype == 1){
1884                                 if (isset($open_tags{$tagname})){
1885                                     $open_tags{$tagname}++;
1886                                 } else {
1887                                     $open_tags{$tagname}=1;
1888                                 }
1889                             }
1890                             /**
1891                              * This is where we run other checks.
1892                              */
1893                             if (is_array($attary) && sizeof($attary) > 0){
1894                                 $attary = sq_fixatts($tagname,
1895                                                      $attary,
1896                                                      $rm_attnames,
1897                                                      $bad_attvals,
1898                                                      $add_attr_to_tag,
1899                                                      $message,
1900                                                      $id,
1901                                                      $mailbox
1902                                                      );
1903                             }
1904                         }
1905                     }
1906                 }
1907             }
1908             if ($tagname != false && $skip_content == false){
1909                 $trusted .= sq_tagprint($tagname, $attary, $tagtype);
1910             }
1911         }
1912         $curpos = $gt+1;
1913     }
1914     $trusted .= substr($body, $curpos, strlen($body)-$curpos);
1915     if ($force_tag_closing == true){
1916         foreach ($open_tags as $tagname=>$opentimes){
1917             while ($opentimes > 0){
1918                 $trusted .= '</' . $tagname . '>';
1919                 $opentimes--;
1920             }
1921         }
1922         $trusted .= "\n";
1923     }
1924     $trusted .= "<!-- end sanitized html -->\n";
1925     return $trusted;
1926 }
1927
1928 /**
1929  * This is a wrapper function to call html sanitizing routines.
1930  *
1931  * @param  $body  the body of the message
1932  * @param  $id    the id of the message
1933
1934  * @param  $message
1935  * @param  $mailbox
1936  * @param  boolean $take_mailto_links When TRUE, converts mailto: links
1937  *                                    into internal SM compose links
1938  *                                    (optional; default = TRUE)
1939  * @return        a string with html safe to display in the browser.
1940  */
1941 function magicHTML($body, $id, $message, $mailbox = 'INBOX', $take_mailto_links =true) {
1942
1943     require_once(SM_PATH . 'functions/url_parser.php');  // for $MailTo_PReg_Match
1944
1945     global $attachment_common_show_images, $view_unsafe_images,
1946            $has_unsafe_images;
1947     /**
1948      * Don't display attached images in HTML mode.
1949      */
1950     $attachment_common_show_images = false;
1951     $tag_list = Array(
1952             false,
1953             "object",
1954             "meta",
1955             "html",
1956             "head",
1957             "base",
1958             "link",
1959             "frame",
1960             "iframe",
1961             "plaintext",
1962             "marquee"
1963             );
1964
1965     $rm_tags_with_content = Array(
1966             "script",
1967             "applet",
1968             "embed",
1969             "title",
1970             "frameset",
1971             "xmp",
1972             "xml"
1973             );
1974
1975     $self_closing_tags =  Array(
1976             "img",
1977             "br",
1978             "hr",
1979             "input",
1980             "outbind"
1981             );
1982
1983     $force_tag_closing = true;
1984
1985     $rm_attnames = Array(
1986             "/.*/" =>
1987             Array(
1988                 "/target/i",
1989                 "/^on.*/i",
1990                 "/^dynsrc/i",
1991                 "/^data.*/i",
1992                 "/^lowsrc.*/i"
1993                 )
1994             );
1995
1996     $secremoveimg = "../images/" . _("sec_remove_eng.png");
1997     $bad_attvals = Array(
1998             "/.*/" =>
1999             Array(
2000                 "/^src|background/i" =>
2001                 Array(
2002                     Array(
2003                         "/^([\'\"])\s*\S+script\s*:.*([\'\"])/si",
2004                         "/^([\'\"])\s*mocha\s*:*.*([\'\"])/si",
2005                         "/^([\'\"])\s*about\s*:.*([\'\"])/si"
2006                         ),
2007                     Array(
2008                         "\\1$secremoveimg\\2",
2009                         "\\1$secremoveimg\\2",
2010                         "\\1$secremoveimg\\2",
2011                         "\\1$secremoveimg\\2"
2012                         )
2013                     ),
2014                 "/^href|action/i" =>
2015                 Array(
2016                     Array(
2017                         "/^([\'\"])\s*\S+script\s*:.*([\'\"])/si",
2018                         "/^([\'\"])\s*mocha\s*:*.*([\'\"])/si",
2019                         "/^([\'\"])\s*about\s*:.*([\'\"])/si"
2020                         ),
2021                     Array(
2022                         "\\1#\\1",
2023                         "\\1#\\1",
2024                         "\\1#\\1",
2025                         "\\1#\\1"
2026                         )
2027                     ),
2028         "/^style/i" =>
2029             Array(
2030                 Array(
2031                     "/expression/i",
2032                     "/binding/i",
2033                     "/behaviou*r/i",
2034                     "/include-source/i",
2035                     "/position\s*:\s*absolute/i",
2036                     "/url\s*\(\s*([\'\"])\s*\S+script\s*:.*([\'\"])\s*\)/si",
2037                     "/url\s*\(\s*([\'\"])\s*mocha\s*:.*([\'\"])\s*\)/si",
2038                     "/url\s*\(\s*([\'\"])\s*about\s*:.*([\'\"])\s*\)/si",
2039                     "/(.*)\s*:\s*url\s*\(\s*([\'\"]*)\s*\S+script\s*:.*([\'\"]*)\s*\)/si"
2040                     ),
2041                 Array(
2042                     "idiocy",
2043                     "idiocy",
2044                     "idiocy",
2045                     "idiocy",
2046                     "",
2047                     "url(\\1#\\1)",
2048                     "url(\\1#\\1)",
2049                     "url(\\1#\\1)",
2050                     "url(\\1#\\1)",
2051                     "url(\\1#\\1)",
2052                     "\\1:url(\\2#\\3)"
2053                     )
2054                 )
2055             )
2056         );
2057     if( !sqgetGlobalVar('view_unsafe_images', $view_unsafe_images, SQ_GET) ) {
2058         $view_unsafe_images = false;
2059     }
2060     if (!$view_unsafe_images){
2061         /**
2062          * Remove any references to http/https if view_unsafe_images set
2063          * to false.
2064          */
2065         array_push($bad_attvals{'/.*/'}{'/^src|background/i'}[0],
2066                 '/^([\'\"])\s*https*:.*([\'\"])/si');
2067         array_push($bad_attvals{'/.*/'}{'/^src|background/i'}[1],
2068                 "\\1$secremoveimg\\1");
2069         array_push($bad_attvals{'/.*/'}{'/^style/i'}[0],
2070                 '/url\(([\'\"])\s*https*:.*([\'\"])\)/si');
2071         array_push($bad_attvals{'/.*/'}{'/^style/i'}[1],
2072                 "url(\\1$secremoveimg\\1)");
2073     }
2074
2075     $add_attr_to_tag = Array(
2076             "/^a$/i" =>
2077             Array('target'=>'"_blank"',
2078                 'title'=>'"'._("This external link will open in a new window").'"'
2079                 )
2080             );
2081     $trusted = sq_sanitize($body,
2082                            $tag_list,
2083                            $rm_tags_with_content,
2084                            $self_closing_tags,
2085                            $force_tag_closing,
2086                            $rm_attnames,
2087                            $bad_attvals,
2088                            $add_attr_to_tag,
2089                            $message,
2090                            $id,
2091                            $mailbox
2092                            );
2093     if (preg_match("|$secremoveimg|i", $trusted)){
2094         $has_unsafe_images = true;
2095     }
2096
2097     // we want to parse mailto's in HTML output, change to SM compose links
2098     // this is a modified version of code from url_parser.php... but Marc is
2099     // right: we need a better filtering implementation; adding this randomly
2100     // here is not a great solution
2101     //
2102     if ($take_mailto_links) {
2103         // parseUrl($trusted);   // this even parses URLs inside of tags... too aggressive
2104         global $MailTo_PReg_Match;
2105         $MailTo_PReg_Match = '/mailto:' . substr($MailTo_PReg_Match, 1);
2106         if ((preg_match_all($MailTo_PReg_Match, $trusted, $regs)) && ($regs[0][0] != '')) {
2107             foreach ($regs[0] as $i => $mailto_before) {
2108                 $mailto_params = $regs[10][$i];
2109                 // get rid of any tailing quote since we have to add send_to to the end
2110                 //
2111                 if (substr($mailto_before, strlen($mailto_before) - 1) == '"')
2112                     $mailto_before = substr($mailto_before, 0, strlen($mailto_before) - 1);
2113                 if (substr($mailto_params, strlen($mailto_params) - 1) == '"')
2114                     $mailto_params = substr($mailto_params, 0, strlen($mailto_params) - 1);
2115
2116                 if ($regs[1][$i]) {    //if there is an email addr before '?', we need to merge it with the params
2117                     $to = 'to=' . $regs[1][$i];
2118                     if (strpos($mailto_params, 'to=') > -1)    //already a 'to='
2119                         $mailto_params = str_replace('to=', $to . '%2C%20', $mailto_params);
2120                     else {
2121                         if ($mailto_params)    //already some params, append to them
2122                             $mailto_params .= '&amp;' . $to;
2123                         else
2124                             $mailto_params .= '?' . $to;
2125                     }
2126                 }
2127
2128                 $url_str = preg_replace(array('/to=/i', '/(?<!b)cc=/i', '/bcc=/i'), array('send_to=', 'send_to_cc=', 'send_to_bcc='), $mailto_params);
2129
2130                 // we'll already have target=_blank, no need to allow comp_in_new
2131                 // here (which would be a lot more work anyway)
2132                 //
2133                 global $compose_new_win;
2134                 $temp_comp_in_new = $compose_new_win;
2135                 $compose_new_win = 0;
2136                 $comp_uri = makeComposeLink('src/compose.php' . $url_str, $mailto_before);
2137                 $compose_new_win = $temp_comp_in_new;
2138
2139                 // remove <a href=" and anything after the next quote (we only
2140                 // need the uri, not the link HTML) in compose uri
2141                 //
2142                 $comp_uri = substr($comp_uri, 9);
2143                 $comp_uri = substr($comp_uri, 0, strpos($comp_uri, '"', 1));
2144                 $trusted = str_replace($mailto_before, $comp_uri, $trusted);
2145             }
2146         }
2147     }
2148
2149     return $trusted;
2150 }
2151
2152 /**
2153  * function SendDownloadHeaders - send file to the browser
2154  *
2155  * Original Source: SM core src/download.php
2156  * moved here to make it available to other code, and separate
2157  * front end from back end functionality.
2158  *
2159  * @param string $type0 first half of mime type
2160  * @param string $type1 second half of mime type
2161  * @param string $filename filename to tell the browser for downloaded file
2162  * @param boolean $force whether to force the download dialog to pop
2163  * @param optional integer $filesize send the Content-Header and length to the browser
2164  * @return void
2165  */
2166 function SendDownloadHeaders($type0, $type1, $filename, $force, $filesize=0) {
2167     global $languages, $squirrelmail_language;
2168     $isIE = $isIE6 = 0;
2169
2170     sqgetGlobalVar('HTTP_USER_AGENT', $HTTP_USER_AGENT, SQ_SERVER);
2171
2172     if (strstr($HTTP_USER_AGENT, 'compatible; MSIE ') !== false &&
2173             strstr($HTTP_USER_AGENT, 'Opera') === false) {
2174         $isIE = 1;
2175     }
2176
2177     if (strstr($HTTP_USER_AGENT, 'compatible; MSIE 6') !== false &&
2178             strstr($HTTP_USER_AGENT, 'Opera') === false) {
2179         $isIE6 = 1;
2180     }
2181
2182     if (isset($languages[$squirrelmail_language]['XTRA_CODE']) &&
2183             function_exists($languages[$squirrelmail_language]['XTRA_CODE'] . '_downloadfilename')) {
2184         $filename =
2185             call_user_func($languages[$squirrelmail_language]['XTRA_CODE'] . '_downloadfilename', $filename, $HTTP_USER_AGENT);
2186     } else {
2187         $filename = ereg_replace('[\\/:\*\?"<>\|;]', '_', str_replace('&nbsp;', ' ', $filename));
2188     }
2189
2190     // A Pox on Microsoft and it's Internet Explorer!
2191     //
2192     // IE has lots of bugs with file downloads.
2193     // It also has problems with SSL.  Both of these cause problems
2194     // for us in this function.
2195     //
2196     // See this article on Cache Control headers and SSL
2197     // http://support.microsoft.com/default.aspx?scid=kb;en-us;323308
2198     //
2199     // The best thing you can do for IE is to upgrade to the latest
2200     // version
2201     //set all the Cache Control Headers for IE
2202     if ($isIE) {
2203         $filename=rawurlencode($filename);
2204         header ("Pragma: public");
2205         header ("Cache-Control: no-store, max-age=0, no-cache, must-revalidate"); // HTTP/1.1
2206         header ("Cache-Control: post-check=0, pre-check=0", false);
2207         header ("Cache-Control: private");
2208
2209         //set the inline header for IE, we'll add the attachment header later if we need it
2210         header ("Content-Disposition: inline; filename=$filename");
2211     }
2212
2213     if (!$force) {
2214         // Try to show in browser window
2215         header ("Content-Disposition: inline; filename=\"$filename\"");
2216         header ("Content-Type: $type0/$type1; name=\"$filename\"");
2217     } else {
2218         // Try to pop up the "save as" box
2219
2220         // IE makes this hard.  It pops up 2 save boxes, or none.
2221         // http://support.microsoft.com/support/kb/articles/Q238/5/88.ASP
2222         // http://support.microsoft.com/default.aspx?scid=kb;EN-US;260519
2223         // But, according to Microsoft, it is "RFC compliant but doesn't
2224         // take into account some deviations that allowed within the
2225         // specification."  Doesn't that mean RFC non-compliant?
2226         // http://support.microsoft.com/support/kb/articles/Q258/4/52.ASP
2227
2228         // all browsers need the application/octet-stream header for this
2229         header ("Content-Type: application/octet-stream; name=\"$filename\"");
2230
2231         // http://support.microsoft.com/support/kb/articles/Q182/3/15.asp
2232         // Do not have quotes around filename, but that applied to
2233         // "attachment"... does it apply to inline too?
2234         header ("Content-Disposition: attachment; filename=\"$filename\"");
2235
2236         if ($isIE && !$isIE6) {
2237             // This combination seems to work mostly.  IE 5.5 SP 1 has
2238             // known issues (see the Microsoft Knowledge Base)
2239
2240             // This works for most types, but doesn't work with Word files
2241             header ("Content-Type: application/download; name=\"$filename\"");
2242
2243             // These are spares, just in case.  :-)
2244             //header("Content-Type: $type0/$type1; name=\"$filename\"");
2245             //header("Content-Type: application/x-msdownload; name=\"$filename\"");
2246             //header("Content-Type: application/octet-stream; name=\"$filename\"");
2247         } else {
2248             // another application/octet-stream forces download for Netscape
2249             header ("Content-Type: application/octet-stream; name=\"$filename\"");
2250         }
2251     }
2252
2253     //send the content-length header if the calling function provides it
2254     if ($filesize > 0) {
2255         header("Content-Length: $filesize");
2256     }
2257
2258 }  // end fn SendDownloadHeaders
2259
2260 ?>