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
  20 /* -------------------------------------------------------------------------- */
  21 /* MIME DECODING                                                              */
  22 /* -------------------------------------------------------------------------- */
  23
  24 /**
  25  * Get the MIME structure
  26  *
  27  * This function gets the structure of a message and stores it in the "message" class.
  28  * It will return this object for use with all relevant header information and
  29  * fully parsed into the standard "message" object format.
  30  */
  31 function mime_structure ($bodystructure, $flags=array()) {
  32
  33     /* Isolate the body structure and remove beginning and end parenthesis. */
  34     $read = trim(substr ($bodystructure, strpos(strtolower($bodystructure), 'bodystructure') + 13));
  35     $read = trim(substr ($read, 0, -1));
  36     $i = 0;
  37     $msg = Message::parseStructure($read,$i);
  38     if (!is_object($msg)) {
  39         include_once(SM_PATH . 'functions/display_messages.php');
  40         global $color, $mailbox;
  41         /* removed urldecode because $_GET is auto urldecoded ??? */
  42         displayPageHeader( $color, $mailbox );
  43         $errormessage  = _("SquirrelMail could not decode the bodystructure of the message");
  44         $errormessage .= '<br />'._("the provided bodystructure by your imap-server").':<br /><br />';
  45         $errormessage .= '<pre>' . htmlspecialchars($read) . '</pre>';
  46         plain_error_message( $errormessage, $color );
  47         echo '</body></html>';
  48         exit;
  49     }
  50     if (count($flags)) {
  51         foreach ($flags as $flag) {
  52             $char = strtoupper($flag{1});
  53             switch ($char) {
  54                 case 'S':
  55                     if (strtolower($flag) == '\\seen') {
  56                         $msg->is_seen = true;
  57                     }
  58                     break;
  59                 case 'A':
  60                     if (strtolower($flag) == '\\answered') {
  61                         $msg->is_answered = true;
  62                     }
  63                     break;
  64                 case 'D':
  65                     if (strtolower($flag) == '\\deleted') {
  66                         $msg->is_deleted = true;
  67                     }
  68                     break;
  69                 case 'F':
  70                     if (strtolower($flag) == '\\flagged') {
  71                         $msg->is_flagged = true;
  72                     }
  73                     break;
  74                 case 'M':
  75                     if (strtolower($flag) == '$mdnsent') {
  76                         $msg->is_mdnsent = true;
  77                     }
  78                     break;
  79                 default:
  80                     break;
  81             }
  82         }
  83     }
  84     //    listEntities($msg);
  85     return $msg;
  86 }
  87
  88
  89
  90 /* This starts the parsing of a particular structure.  It is called recursively,
  91  * so it can be passed different structures.  It returns an object of type
  92  * $message.
  93  * First, it checks to see if it is a multipart message.  If it is, then it
  94  * handles that as it sees is necessary.  If it is just a regular entity,
  95  * then it parses it and adds the necessary header information (by calling out
  96  * to mime_get_elements()
  97  */
  98
  99 function mime_fetch_body($imap_stream, $id, $ent_id=1, $fetch_size=0) {
 100     /* Do a bit of error correction.  If we couldn't find the entity id, just guess
 101      * that it is the first one.  That is usually the case anyway.
 102      */
 103
 104     if (!$ent_id) {
 105         $cmd = "FETCH $id BODY[]";
 106     } else {
 107         $cmd = "FETCH $id BODY[$ent_id]";
 108     }
 109
 110     if ($fetch_size!=0) $cmd .= "<0.$fetch_size>";
 111
 112     $data = sqimap_run_command ($imap_stream, $cmd, true, $response, $message, TRUE);
 113     do {
 114         $topline = trim(array_shift($data));
 115     } while($topline && ($topline[0] == '*') && !preg_match('/\* [0-9]+ FETCH.*/i', $topline)) ;
 116
 117     $wholemessage = implode('', $data);
 118     if (ereg('\\{([^\\}]*)\\}', $topline, $regs)) {
 119         $ret = substr($wholemessage, 0, $regs[1]);
 120         /* There is some information in the content info header that could be important
 121          * in order to parse html messages. Let's get them here.
 122          */
 123 //        if ($ret{0} == '<') {
 124 //            $data = sqimap_run_command ($imap_stream, "FETCH $id BODY[$ent_id.MIME]", true, $response, $message, TRUE);
 125 //        }
 126     } else if (ereg('"([^"]*)"', $topline, $regs)) {
 127         $ret = $regs[1];
 128     } else {
 129         global $where, $what, $mailbox, $passed_id, $startMessage;
 130         $par = 'mailbox=' . urlencode($mailbox) . '&amp;passed_id=' . $passed_id;
 131         if (isset($where) && isset($what)) {
 132             $par .= '&amp;where=' . urlencode($where) . '&amp;what=' . urlencode($what);
 133         } else {
 134             $par .= '&amp;startMessage=' . $startMessage . '&amp;show_more=0';
 135         }
 136         $par .= '&amp;response=' . urlencode($response) .
 137                 '&amp;message='  . urlencode($message)  .
 138                 '&amp;topline='  . urlencode($topline);
 139
 140         echo   '<tt><br />' .
 141                '<table width="80%"><tr>' .
 142                '<tr><td colspan="2">' .
 143                _("Body retrieval error. The reason for this is most probably that the message is malformed.") .
 144                '</td></tr>' .
 145                '<tr><td><b>' . _("Command:") . "</td><td>$cmd</td></tr>" .
 146                '<tr><td><b>' . _("Response:") . "</td><td>$response</td></tr>" .
 147                '<tr><td><b>' . _("Message:") . "</td><td>$message</td></tr>" .
 148                '<tr><td><b>' . _("FETCH line:") . "</td><td>$topline</td></tr>" .
 149                "</table><br /></tt></font><hr />";
 150
 151         $data = sqimap_run_command ($imap_stream, "FETCH $passed_id BODY[]", true, $response, $message, TRUE);
 152         array_shift($data);
 153         $wholemessage = implode('', $data);
 154
 155         $ret = $wholemessage;
 156     }
 157     return $ret;
 158 }
 159
 160 function mime_print_body_lines ($imap_stream, $id, $ent_id=1, $encoding) {
 161
 162     /* Don't kill the connection if the browser is over a dialup
 163      * and it would take over 30 seconds to download it.
 164      * Don't call set_time_limit in safe mode.
 165      */
 166
 167     if (!ini_get('safe_mode')) {
 168         set_time_limit(0);
 169     }
 170     /* in case of base64 encoded attachments, do not buffer them.
 171        Instead, echo the decoded attachment directly to screen */
 172     if (strtolower($encoding) == 'base64') {
 173         if (!$ent_id) {
 174            $query = "FETCH $id BODY[]";
 175         } else {
 176            $query = "FETCH $id BODY[$ent_id]";
 177         }
 178         sqimap_run_command($imap_stream,$query,true,$response,$message,TRUE,'sqimap_base64_decode','php://stdout',true);
 179     } else {
 180        $body = mime_fetch_body ($imap_stream, $id, $ent_id);
 181        echo decodeBody($body, $encoding);
 182     }
 183
 184     /*
 185        TODO, use the same method for quoted printable.
 186        However, I assume that quoted printable attachments aren't that large
 187        so the performancegain / memory usage drop will be minimal.
 188        If we decide to add that then we need to adapt sqimap_fread because
 189        we need to split te result on \n and fread doesn't stop at \n. That
 190        means we also should provide $results from sqimap_fread (by ref) to
 191        te function and set $no_return to false. The $filter function for
 192        quoted printable should handle unsetting of $results.
 193     */
 194     /*
 195        TODO 2: find out how we write to the output stream php://stdout. fwrite
 196        doesn't work because 'php://stdout isn't a stream.
 197     */
 198
 199     return;
 200 /*
 201     fputs ($imap_stream, "$sid FETCH $id BODY[$ent_id]\r\n");
 202     $cnt = 0;
 203     $continue = true;
 204     $read = fgets ($imap_stream,8192);
 205
 206
 207     // This could be bad -- if the section has sqimap_session_id() . ' OK'
 208     // or similar, it will kill the download.
 209     while (!ereg("^".$sid_s." (OK|BAD|NO)(.*)$", $read, $regs)) {
 210         if (trim($read) == ')==') {
 211             $read1 = $read;
 212             $read = fgets ($imap_stream,4096);
 213             if (ereg("^".$sid." (OK|BAD|NO)(.*)$", $read, $regs)) {
 214                 return;
 215             } else {
 216                 echo decodeBody($read1, $encoding) .
 217                      decodeBody($read, $encoding);
 218             }
 219         } else if ($cnt) {
 220             echo decodeBody($read, $encoding);
 221         }
 222         $read = fgets ($imap_stream,4096);
 223         $cnt++;
 224 //      break;
 225     }
 226 */
 227 }
 228
 229 /* -[ END MIME DECODING ]----------------------------------------------------------- */
 230
 231 /* This is here for debugging purposes.  It will print out a list
 232  * of all the entity IDs that are in the $message object.
 233  */
 234 function listEntities ($message) {
 235     if ($message) {
 236         echo "<tt>" . $message->entity_id . ' : ' . $message->type0 . '/' . $message->type1 . ' parent = '. $message->parent->entity_id. '<br />';
 237         for ($i = 0; isset($message->entities[$i]); $i++) {
 238             echo "$i : ";
 239             $msg = listEntities($message->entities[$i]);
 240
 241             if ($msg) {
 242                 echo "return: ";
 243                 return $msg;
 244             }
 245         }
 246     }
 247 }
 248
 249 function getPriorityStr($priority) {
 250     $priority_level = substr($priority,0,1);
 251
 252     switch($priority_level) {
 253         /* Check for a higher then normal priority. */
 254         case '1':
 255         case '2':
 256             $priority_string = _("High");
 257             break;
 258
 259         /* Check for a lower then normal priority. */
 260         case '4':
 261         case '5':
 262             $priority_string = _("Low");
 263             break;
 264
 265         /* Check for a normal priority. */
 266         case '3':
 267         default:
 268             $priority_level = '3';
 269             $priority_string = _("Normal");
 270             break;
 271
 272     }
 273     return $priority_string;
 274 }
 275
 276 /* returns a $message object for a particular entity id */
 277 function getEntity ($message, $ent_id) {
 278     return $message->getEntity($ent_id);
 279 }
 280
 281 /* translateText
 282  * Extracted from strings.php 23/03/2002
 283  */
 284
 285 function translateText(&$body, $wrap_at, $charset) {
 286     global $where, $what;   /* from searching */
 287     global $color;          /* color theme */
 288
 289     require_once(SM_PATH . 'functions/url_parser.php');
 290
 291     $body_ary = explode("\n", $body);
 292     for ($i=0; $i < count($body_ary); $i++) {
 293         $line = $body_ary[$i];
 294         if (strlen($line) - 2 >= $wrap_at) {
 295             sqWordWrap($line, $wrap_at, $charset);
 296         }
 297         $line = charset_decode($charset, $line);
 298         $line = str_replace("\t", '        ', $line);
 299
 300         parseUrl ($line);
 301
 302         $quotes = 0;
 303         $pos = 0;
 304         $j = strlen($line);
 305
 306         while ($pos < $j) {
 307             if ($line[$pos] == ' ') {
 308                 $pos++;
 309             } else if (strpos($line, '&gt;', $pos) === $pos) {
 310                 $pos += 4;
 311                 $quotes++;
 312             } else {
 313                 break;
 314             }
 315         }
 316
 317         if ($quotes % 2) {
 318             if (!isset($color[13])) {
 319                 $color[13] = '#800000';
 320             }
 321             $line = '<font color="' . $color[13] . '">' . $line . '</font>';
 322         } elseif ($quotes) {
 323             if (!isset($color[14])) {
 324                 $color[14] = '#FF0000';
 325             }
 326             $line = '<font color="' . $color[14] . '">' . $line . '</font>';
 327         }
 328
 329         $body_ary[$i] = $line;
 330     }
 331     $body = '<pre>' . implode("\n", $body_ary) . '</pre>';
 332 }
 333
 334 /**
 335  * This returns a parsed string called $body. That string can then
 336  * be displayed as the actual message in the HTML. It contains
 337  * everything needed, including HTML Tags, Attachments at the
 338  * bottom, etc.
 339  * @param clean Do not output stuff that's irrelevant for the printable version.
 340  */
 341 function formatBody($imap_stream, $message, $color, $wrap_at, $ent_num, $id, $mailbox='INBOX', $clean=FALSE) {
 342     /* This if statement checks for the entity to show as the
 343      * primary message. To add more of them, just put them in the
 344      * order that is their priority.
 345      */
 346     global $startMessage, $languages, $squirrelmail_language,
 347            $show_html_default, $sort, $has_unsafe_images, $passed_ent_id;
 348
 349     if( !sqgetGlobalVar('view_unsafe_images', $view_unsafe_images, SQ_GET) ) {
 350         $view_unsafe_images = false;
 351     }
 352
 353     $body = '';
 354     $urlmailbox = urlencode($mailbox);
 355     $body_message = getEntity($message, $ent_num);
 356     if (($body_message->header->type0 == 'text') ||
 357         ($body_message->header->type0 == 'rfc822')) {
 358         $body = mime_fetch_body ($imap_stream, $id, $ent_num);
 359         $body = decodeBody($body, $body_message->header->encoding);
 360
 361         if (isset($languages[$squirrelmail_language]['XTRA_CODE']) &&
 362             function_exists($languages[$squirrelmail_language]['XTRA_CODE'] . '_decode')) {
 363             if (mb_detect_encoding($body) != 'ASCII') {
 364                 $body = call_user_func($languages[$squirrelmail_language]['XTRA_CODE'] . '_decode',$body);
 365             }
 366         }
 367         $hookResults = do_hook("message_body", $body);
 368         $body = $hookResults[1];
 369
 370         /* If there are other types that shouldn't be formatted, add
 371          * them here.
 372          */
 373
 374         if ($body_message->header->type1 == 'html') {
 375             if ($show_html_default <> 1) {
 376                 $entity_conv = array('&nbsp;' => ' ',
 377                                      '<p>'    => "\n",
 378                                      '<P>'    => "\n",
 379                                      '<br>'   => "\n",
 380                                      '<BR>'   => "\n",
 381                                      '<br />' => "\n",
 382                                      '<BR />' => "\n",
 383                                      '&gt;'   => '>',
 384                                      '&lt;'   => '<');
 385                 $body = strtr($body, $entity_conv);
 386                 $body = strip_tags($body);
 387                 $body = trim($body);
 388                 translateText($body, $wrap_at,
 389                               $body_message->header->getParameter('charset'));
 390             } else {
 391                 $body = magicHTML($body, $id, $message, $mailbox);
 392             }
 393         } else {
 394             translateText($body, $wrap_at,
 395                           $body_message->header->getParameter('charset'));
 396         }
 397
 398         // if this is the clean display (i.e. printer friendly), stop here.
 399         if ( $clean ) {
 400             return $body;
 401         }
 402
 403         $link = 'passed_id=' . $id . '&amp;ent_id='.$ent_num.
 404                 '&amp;mailbox=' . $urlmailbox .'&amp;sort=' . $sort .
 405                 '&amp;startMessage=' . $startMessage . '&amp;show_more=0';
 406         if (isset($passed_ent_id)) {
 407             $link .= '&amp;passed_ent_id='.$passed_ent_id;
 408         }
 409         $body .= '<center><small><a href="download.php?absolute_dl=true&amp;' .
 410                  $link . '">' . _("Download this as a file") .  '</a>';
 411         if ($view_unsafe_images) {
 412             $text = _("Hide Unsafe Images");
 413         } else {
 414             if (isset($has_unsafe_images) && $has_unsafe_images) {
 415                 $link .= '&amp;view_unsafe_images=1';
 416                 $text = _("View Unsafe Images");
 417             } else {
 418                 $text = '';
 419             }
 420         }
 421         if($text != '') {
 422             $body .= '&nbsp;|&nbsp;<a href="read_body.php?' . $link . '">' . $text . '</a>';
 423         }
 424         $body .= '</small></center><br />' . "\n";
 425     }
 426     return $body;
 427 }
 428
 429
 430 function formatAttachments($message, $exclude_id, $mailbox, $id) {
 431     global $where, $what, $startMessage, $color, $passed_ent_id;
 432
 433     $att_ar = $message->getAttachments($exclude_id);
 434
 435     if (!count($att_ar)) return '';
 436
 437     $attachments = '';
 438
 439     $urlMailbox = urlencode($mailbox);
 440
 441     foreach ($att_ar as $att) {
 442         $ent = $att->entity_id;
 443         $header = $att->header;
 444         $type0 = strtolower($header->type0);
 445         $type1 = strtolower($header->type1);
 446         $name = '';
 447         $links['download link']['text'] = _("Download");
 448         $links['download link']['href'] = SM_PATH .
 449                 "src/download.php?absolute_dl=true&amp;passed_id=$id&amp;mailbox=$urlMailbox&amp;ent_id=$ent";
 450         if ($type0 =='message' && $type1 == 'rfc822') {
 451             $default_page = SM_PATH . 'src/read_body.php';
 452             $rfc822_header = $att->rfc822_header;
 453             $filename = $rfc822_header->subject;
 454             if (trim( $filename ) == '') {
 455                 $filename = 'untitled-[' . $ent . ']' ;
 456             }
 457             $from_o = $rfc822_header->from;
 458             if (is_object($from_o)) {
 459                 $from_name = decodeHeader($from_o->getAddress(false));
 460             } else {
 461                 $from_name = _("Unknown sender");
 462             }
 463             $description = $from_name;
 464         } else {
 465             $default_page = SM_PATH . 'src/download.php';
 466             if (is_object($header->disposition)) {
 467                 $filename = $header->disposition->getProperty('filename');
 468                 if (trim($filename) == '') {
 469                     $name = decodeHeader($header->disposition->getProperty('name'));
 470                     if (trim($name) == '') {
 471                         $name = $header->getParameter('name');
 472                         if(trim($name) == '') {
 473                             if (trim( $header->id ) == '') {
 474                                 $filename = 'untitled-[' . $ent . ']' ;
 475                             } else {
 476                                 $filename = 'cid: ' . $header->id;
 477                             }
 478                         } else {
 479                             $filename = $name;
 480                         }
 481                     } else {
 482                         $filename = $name;
 483                     }
 484                 }
 485             } else {
 486                 $filename = $header->getParameter('name');
 487                 if (!trim($filename)) {
 488                     if (trim( $header->id ) == '') {
 489                         $filename = 'untitled-[' . $ent . ']' ;
 490                     } else {
 491                         $filename = 'cid: ' . $header->id;
 492                     }
 493                 }
 494             }
 495             if ($header->description) {
 496                 $description = decodeHeader($header->description);
 497             } else {
 498                 $description = '';
 499             }
 500         }
 501
 502         $display_filename = $filename;
 503         if (isset($passed_ent_id)) {
 504             $passed_ent_id_link = '&amp;passed_ent_id='.$passed_ent_id;
 505         } else {
 506             $passed_ent_id_link = '';
 507         }
 508         $defaultlink = $default_page . "?startMessage=$startMessage"
 509                      . "&amp;passed_id=$id&amp;mailbox=$urlMailbox"
 510                      . '&amp;ent_id='.$ent.$passed_ent_id_link;
 511         if ($where && $what) {
 512            $defaultlink .= '&amp;where='. urlencode($where).'&amp;what='.urlencode($what);
 513         }
 514
 515         /* This executes the attachment hook with a specific MIME-type.
 516          * If that doesn't have results, it tries if there's a rule
 517          * for a more generic type.
 518          */
 519         $hookresults = do_hook("attachment $type0/$type1", $links,
 520                                $startMessage, $id, $urlMailbox, $ent, $defaultlink,
 521                                $display_filename, $where, $what);
 522         if(count($hookresults[1]) <= 1) {
 523             $hookresults = do_hook("attachment $type0/*", $links,
 524                                    $startMessage, $id, $urlMailbox, $ent, $defaultlink,
 525                                    $display_filename, $where, $what);
 526         }
 527
 528         $links = $hookresults[1];
 529         $defaultlink = $hookresults[6];
 530
 531         $attachments .= '<tr><td>' .
 532                         '<a href="'.$defaultlink.'">'.decodeHeader($display_filename).'</a>&nbsp;</td>' .
 533                         '<td><small><b>' . show_readable_size($header->size) .
 534                         '</b>&nbsp;&nbsp;</small></td>' .
 535                         '<td><small>[ '.htmlspecialchars($type0).'/'.htmlspecialchars($type1).' ]&nbsp;</small></td>' .
 536                         '<td><small>';
 537         $attachments .= '<b>' . $description . '</b>';
 538         $attachments .= '</small></td><td><small>&nbsp;';
 539
 540         $skipspaces = 1;
 541         foreach ($links as $val) {
 542             if ($skipspaces) {
 543                 $skipspaces = 0;
 544             } else {
 545                 $attachments .= '&nbsp;&nbsp;|&nbsp;&nbsp;';
 546             }
 547             $attachments .= '<a href="' . $val['href'] . '">' .  $val['text'] . '</a>';
 548         }
 549         unset($links);
 550         $attachments .= "</td></tr>\n";
 551     }
 552     $attachmentadd = do_hook_function('attachments_bottom',$attachments);
 553     if ($attachmentadd != '')
 554         $attachments = $attachmentadd;
 555     return $attachments;
 556 }
 557
 558 function sqimap_base64_decode(&$string) {
 559
 560     // Base64 encoded data goes in pairs of 4 bytes. To achieve on the
 561     // fly decoding (to reduce memory usage) you have to check if the
 562     // data has incomplete pairs
 563
 564     // Remove the noise in order to check if the 4 bytes pairs are complete
 565     $string = str_replace(array("\r\n","\n", "\r", " "),array('','','',''),$string);
 566
 567     $sStringRem = '';
 568     $iMod = strlen($string) % 4;
 569     if ($iMod) {
 570         $sStringRem = substr($string,-$iMod);
 571         // Check if $sStringRem contains padding characters
 572         if (substr($sStringRem,-1) != '=') {
 573             $string = substr($string,0,-$iMod);
 574         } else {
 575             $sStringRem = '';
 576         }
 577     }
 578     $string = base64_decode($string);
 579     return $sStringRem;
 580 }
 581
 582
 583 /* This function decodes the body depending on the encoding type. */
 584 function decodeBody($body, $encoding) {
 585     global $show_html_default;
 586
 587     $body = str_replace("\r\n", "\n", $body);
 588     $encoding = strtolower($encoding);
 589
 590     $encoding_handler = do_hook_function('decode_body', $encoding);
 591
 592
 593     // plugins get first shot at decoding the body
 594     //
 595     if (!empty($encoding_handler) && function_exists($encoding_handler)) {
 596         $body = $encoding_handler('decode', $body);
 597
 598     } else if ($encoding == 'quoted-printable' ||
 599         $encoding == 'quoted_printable') {
 600         $body = quoted_printable_decode($body);
 601
 602         while (ereg("=\n", $body)) {
 603             $body = ereg_replace ("=\n", '', $body);
 604         }
 605
 606     } else if ($encoding == 'base64') {
 607         $body = base64_decode($body);
 608     }
 609
 610     // All other encodings are returned raw.
 611     return $body;
 612 }
 613
 614 /**
 615  * Decodes headers
 616  *
 617  * This functions decode strings that is encoded according to
 618  * RFC1522 (MIME Part Two: Message Header Extensions for Non-ASCII Text).
 619  * Patched by Christian Schmidt <christian@ostenfeld.dk>  23/03/2002
 620  *
 621  * @param string $string header string that has to be made readable
 622  * @param boolean $utfencode change message in order to be readable on user's charset. defaults to true
 623  * @param boolean $htmlsave preserve spaces and sanitize html special characters. defaults to true
 624  * @param boolean $decide decide if string can be utfencoded. defaults to false
 625  * @return string decoded header string
 626  */
 627 function decodeHeader ($string, $utfencode=true,$htmlsave=true,$decide=false) {
 628     global $languages, $squirrelmail_language,$default_charset;
 629     if (is_array($string)) {
 630         $string = implode("\n", $string);
 631     }
 632
 633     if (isset($languages[$squirrelmail_language]['XTRA_CODE']) &&
 634         function_exists($languages[$squirrelmail_language]['XTRA_CODE'] . '_decodeheader')) {
 635         $string = call_user_func($languages[$squirrelmail_language]['XTRA_CODE'] . '_decodeheader', $string);
 636         // Do we need to return at this point?
 637         // return $string;
 638     }
 639     $i = 0;
 640     $iLastMatch = -2;
 641     $encoded = true;
 642
 643     $aString = explode(' ',$string);
 644     $ret = '';
 645     foreach ($aString as $chunk) {
 646         if ($encoded && $chunk === '') {
 647             continue;
 648         } elseif ($chunk === '') {
 649             $ret .= ' ';
 650             continue;
 651         }
 652         $encoded = false;
 653         /* if encoded words are not separated by a linear-space-white we still catch them */
 654         $j = $i-1;
 655
 656         while ($match = preg_match('/^(.*)=\?([^?]*)\?(Q|B)\?([^?]*)\?=(.*)$/Ui',$chunk,$res)) {
 657             /* if the last chunk isn't an encoded string then put back the space, otherwise don't */
 658             if ($iLastMatch !== $j) {
 659                 if ($htmlsave) {
 660                     $ret .= '&#32;';
 661                 } else {
 662                     $ret .= ' ';
 663                 }
 664             }
 665             $iLastMatch = $i;
 666             $j = $i;
 667             if ($htmlsave) {
 668                 $ret .= htmlspecialchars($res[1]);
 669             } else {
 670                 $ret .= $res[1];
 671             }
 672             $encoding = ucfirst($res[3]);
 673
 674             /* decide about valid decoding */
 675             if ($decide && is_conversion_safe($res[2])) {
 676               $utfencode=true;
 677               $can_be_encoded=true;
 678             } else {
 679               $can_be_encoded=false;
 680             }
 681             switch ($encoding)
 682             {
 683             case 'B':
 684                 $replace = base64_decode($res[4]);
 685                 if ($utfencode) {
 686                     if ($can_be_encoded) {
 687                         /* convert string to different charset,
 688                          * if functions asks for it (usually in compose)
 689                          */
 690                         $ret .= charset_convert($res[2],$replace,$default_charset);
 691                     } else {
 692                         // convert string to html codes in order to display it
 693                         $ret .= charset_decode($res[2],$replace);
 694                     }
 695                 } else {
 696                     if ($htmlsave) {
 697                         $replace = htmlspecialchars($replace);
 698                     }
 699                     $ret.= $replace;
 700                 }
 701                 break;
 702             case 'Q':
 703                 $replace = str_replace('_', ' ', $res[4]);
 704                 $replace = preg_replace('/=([0-9a-f]{2})/ie', 'chr(hexdec("\1"))',
 705                                     $replace);
 706                 if ($utfencode) {
 707                   if ($can_be_encoded) {
 708                     /* convert string to different charset,
 709                      * if functions asks for it (usually in compose)
 710                      */
 711                     $replace = charset_convert($res[2], $replace,$default_charset);
 712                   } else {
 713                     // convert string to html codes in order to display it
 714                     $replace = charset_decode($res[2], $replace);
 715                   }
 716                 } else {
 717                     if ($htmlsave) {
 718                         $replace = htmlspecialchars($replace);
 719                     }
 720                 }
 721                 $ret .= $replace;
 722                 break;
 723             default:
 724                 break;
 725             }
 726             $chunk = $res[5];
 727             $encoded = true;
 728         }
 729         if (!$encoded) {
 730             if ($htmlsave) {
 731                 $ret .= '&#32;';
 732             } else {
 733                 $ret .= ' ';
 734             }
 735         }
 736
 737         if (!$encoded && $htmlsave) {
 738             $ret .= htmlspecialchars($chunk);
 739         } else {
 740             $ret .= $chunk;
 741         }
 742         ++$i;
 743     }
 744     /* remove the first added space */
 745     if ($ret) {
 746         if ($htmlsave) {
 747             $ret = substr($ret,5);
 748         } else {
 749             $ret = substr($ret,1);
 750         }
 751     }
 752
 753     return $ret;
 754 }
 755
 756 /**
 757  * Encodes header as quoted-printable
 758  *
 759  * Encode a string according to RFC 1522 for use in headers if it
 760  * contains 8-bit characters or anything that looks like it should
 761  * be encoded.
 762  *
 763  * @param string $string header string, that has to be encoded
 764  * @return string quoted-printable encoded string
 765  */
 766 function encodeHeader ($string) {
 767     global $default_charset, $languages, $squirrelmail_language;
 768
 769     if (isset($languages[$squirrelmail_language]['XTRA_CODE']) &&
 770         function_exists($languages[$squirrelmail_language]['XTRA_CODE'] . '_encodeheader')) {
 771         return  call_user_func($languages[$squirrelmail_language]['XTRA_CODE'] . '_encodeheader', $string);
 772     }
 773
 774     // Encode only if the string contains 8-bit characters or =?
 775     $j = strlen($string);
 776     $max_l = 75 - strlen($default_charset) - 7;
 777     $aRet = array();
 778     $ret = '';
 779     $iEncStart = $enc_init = false;
 780     $cur_l = $iOffset = 0;
 781     for($i = 0; $i < $j; ++$i) {
 782         switch($string{$i})
 783         {
 784         case '=':
 785         case '<':
 786         case '>':
 787         case ',':
 788         case '?':
 789         case '_':
 790             if ($iEncStart === false) {
 791                 $iEncStart = $i;
 792             }
 793             $cur_l+=3;
 794             if ($cur_l > ($max_l-2)) {
 795                 /* if there is an stringpart that doesn't need encoding, add it */
 796                 $aRet[] = substr($string,$iOffset,$iEncStart-$iOffset);
 797                 $aRet[] = "=?$default_charset?Q?$ret?=";
 798                 $iOffset = $i;
 799                 $cur_l = 0;
 800                 $ret = '';
 801                 $iEncStart = false;
 802             } else {
 803                 $ret .= sprintf("=%02X",ord($string{$i}));
 804             }
 805             break;
 806         case '(':
 807         case ')':
 808             if ($iEncStart !== false) {
 809                 $aRet[] = substr($string,$iOffset,$iEncStart-$iOffset);
 810                 $aRet[] = "=?$default_charset?Q?$ret?=";
 811                 $iOffset = $i;
 812                 $cur_l = 0;
 813                 $ret = '';
 814                 $iEncStart = false;
 815             }
 816             break;
 817         case ' ':
 818             if ($iEncStart !== false) {
 819                 $cur_l++;
 820                 if ($cur_l > $max_l) {
 821                     $aRet[] = substr($string,$iOffset,$iEncStart-$iOffset);
 822                     $aRet[] = "=?$default_charset?Q?$ret?=";
 823                     $iOffset = $i;
 824                     $cur_l = 0;
 825                     $ret = '';
 826                     $iEncStart = false;
 827                 } else {
 828                     $ret .= '_';
 829                 }
 830             }
 831             break;
 832         default:
 833             $k = ord($string{$i});
 834             if ($k > 126) {
 835                 if ($iEncStart === false) {
 836                     // do not start encoding in the middle of a string, also take the rest of the word.
 837                     $sLeadString = substr($string,0,$i);
 838                     $aLeadString = explode(' ',$sLeadString);
 839                     $sToBeEncoded = array_pop($aLeadString);
 840                     $iEncStart = $i - strlen($sToBeEncoded);
 841                     $ret .= $sToBeEncoded;
 842                     $cur_l += strlen($sToBeEncoded);
 843                 }
 844                 $cur_l += 3;
 845                 /* first we add the encoded string that reached it's max size */
 846                 if ($cur_l > ($max_l-2)) {
 847                     $aRet[] = substr($string,$iOffset,$iEncStart-$iOffset);
 848                     $aRet[] = "=?$default_charset?Q?$ret?= "; /* the next part is also encoded => separate by space */
 849                     $cur_l = 3;
 850                     $ret = '';
 851                     $iOffset = $i;
 852                     $iEncStart = $i;
 853                 }
 854                 $enc_init = true;
 855                 $ret .= sprintf("=%02X", $k);
 856             } else {
 857                 if ($iEncStart !== false) {
 858                     $cur_l++;
 859                     if ($cur_l > $max_l) {
 860                         $aRet[] = substr($string,$iOffset,$iEncStart-$iOffset);
 861                         $aRet[] = "=?$default_charset?Q?$ret?=";
 862                         $iEncStart = false;
 863                         $iOffset = $i;
 864                         $cur_l = 0;
 865                         $ret = '';
 866                     } else {
 867                         $ret .= $string{$i};
 868                     }
 869                 }
 870             }
 871             break;
 872         }
 873     }
 874
 875     if ($enc_init) {
 876         if ($iEncStart !== false) {
 877             $aRet[] = substr($string,$iOffset,$iEncStart-$iOffset);
 878             $aRet[] = "=?$default_charset?Q?$ret?=";
 879         } else {
 880             $aRet[] = substr($string,$iOffset);
 881         }
 882         $string = implode('',$aRet);
 883     }
 884     return $string;
 885 }
 886
 887 /* This function trys to locate the entity_id of a specific mime element */
 888 function find_ent_id($id, $message) {
 889     for ($i = 0, $ret = ''; $ret == '' && $i < count($message->entities); $i++) {
 890         if ($message->entities[$i]->header->type0 == 'multipart')  {
 891             $ret = find_ent_id($id, $message->entities[$i]);
 892         } else {
 893             if (strcasecmp($message->entities[$i]->header->id, $id) == 0) {
 894 //                if (sq_check_save_extension($message->entities[$i])) {
 895                     return $message->entities[$i]->entity_id;
 896 //                }
 897             }
 898         }
 899     }
 900     return $ret;
 901 }
 902
 903 function sq_check_save_extension($message) {
 904     $filename = $message->getFilename();
 905     $ext = substr($filename, strrpos($filename,'.')+1);
 906     $save_extensions = array('jpg','jpeg','gif','png','bmp');
 907     return in_array($ext, $save_extensions);
 908 }
 909
 910
 911 /**
 912  ** HTMLFILTER ROUTINES
 913  */
 914
 915 /**
 916  * This function is more or less a wrapper around stripslashes. Apparently
 917  * Explorer is stupid enough to just remove the backslashes and then
 918  * execute the content of the attribute as if nothing happened.
 919  * Who does that?
 920  *
 921  * @param  attvalue   The value of the attribute
 922  * @return attvalue   The value of the attribute stripslashed.
 923  */
 924 function sq_unbackslash($attvalue){
 925     /**
 926      * Remove any backslashes. See if there are any first.
 927      */
 928
 929     if (strstr($attvalue, '\\') !== false){
 930         $attvalue = stripslashes($attvalue);
 931     }
 932     return $attvalue;
 933 }
 934
 935 /**
 936  * Kill any tabs, newlines, or carriage returns. Our friends the
 937  * makers of the browser with 95% market value decided that it'd
 938  * be funny to make "java[tab]script" be just as good as "javascript".
 939  *
 940  * @param  attvalue  The attribute value before extraneous spaces removed.
 941  * @return attvalue  The attribute value after extraneous spaces removed.
 942  */
 943 function sq_unspace($attvalue){
 944     if (strcspn($attvalue, "\t\r\n") != strlen($attvalue)){
 945         $attvalue = str_replace(Array("\t", "\r", "\n"), Array('', '', ''),
 946                                 $attvalue);
 947     }
 948     return $attvalue;
 949 }
 950
 951 /**
 952  * This function returns the final tag out of the tag name, an array
 953  * of attributes, and the type of the tag. This function is called by
 954  * sq_sanitize internally.
 955  *
 956  * @param  $tagname  the name of the tag.
 957  * @param  $attary   the array of attributes and their values
 958  * @param  $tagtype  The type of the tag (see in comments).
 959  * @return           a string with the final tag representation.
 960  */
 961 function sq_tagprint($tagname, $attary, $tagtype){
 962     $me = 'sq_tagprint';
 963
 964     if ($tagtype == 2){
 965         $fulltag = '</' . $tagname . '>';
 966     } else {
 967         $fulltag = '<' . $tagname;
 968         if (is_array($attary) && sizeof($attary)){
 969             $atts = Array();
 970             while (list($attname, $attvalue) = each($attary)){
 971                 array_push($atts, "$attname=$attvalue");
 972             }
 973             $fulltag .= ' ' . join(" ", $atts);
 974         }
 975         if ($tagtype == 3){
 976             $fulltag .= ' /';
 977         }
 978         $fulltag .= '>';
 979     }
 980     return $fulltag;
 981 }
 982
 983 /**
 984  * A small helper function to use with array_walk. Modifies a by-ref
 985  * value and makes it lowercase.
 986  *
 987  * @param  $val a value passed by-ref.
 988  * @return      void since it modifies a by-ref value.
 989  */
 990 function sq_casenormalize(&$val){
 991     $val = strtolower($val);
 992 }
 993
 994 /**
 995  * This function skips any whitespace from the current position within
 996  * a string and to the next non-whitespace value.
 997  *
 998  * @param  $body   the string
 999  * @param  $offset the offset within the string where we should start
1000  *                 looking for the next non-whitespace character.
1001  * @return         the location within the $body where the next
1002  *                 non-whitespace char is located.
1003  */
1004 function sq_skipspace($body, $offset){
1005     $me = 'sq_skipspace';
1006     preg_match('/^(\s*)/s', substr($body, $offset), $matches);
1007     if (sizeof($matches{1})){
1008         $count = strlen($matches{1});
1009         $offset += $count;
1010     }
1011     return $offset;
1012 }
1013
1014 /**
1015  * This function looks for the next character within a string.  It's
1016  * really just a glorified "strpos", except it catches if failures
1017  * nicely.
1018  *
1019  * @param  $body   The string to look for needle in.
1020  * @param  $offset Start looking from this position.
1021  * @param  $needle The character/string to look for.
1022  * @return         location of the next occurance of the needle, or
1023  *                 strlen($body) if needle wasn't found.
1024  */
1025 function sq_findnxstr($body, $offset, $needle){
1026     $me  = 'sq_findnxstr';
1027     $pos = strpos($body, $needle, $offset);
1028     if ($pos === FALSE){
1029         $pos = strlen($body);
1030     }
1031     return $pos;
1032 }
1033
1034 /**
1035  * This function takes a PCRE-style regexp and tries to match it
1036  * within the string.
1037  *
1038  * @param  $body   The string to look for needle in.
1039  * @param  $offset Start looking from here.
1040  * @param  $reg    A PCRE-style regex to match.
1041  * @return         Returns a false if no matches found, or an array
1042  *                 with the following members:
1043  *                 - integer with the location of the match within $body
1044  *                 - string with whatever content between offset and the match
1045  *                 - string with whatever it is we matched
1046  */
1047 function sq_findnxreg($body, $offset, $reg){
1048     $me = 'sq_findnxreg';
1049     $matches = Array();
1050     $retarr = Array();
1051     preg_match("%^(.*?)($reg)%si", substr($body, $offset), $matches);
1052     if (!isset($matches{0}) || !$matches{0}){
1053         $retarr = false;
1054     } else {
1055         $retarr{0} = $offset + strlen($matches{1});
1056         $retarr{1} = $matches{1};
1057         $retarr{2} = $matches{2};
1058     }
1059     return $retarr;
1060 }
1061
1062 /**
1063  * This function looks for the next tag.
1064  *
1065  * @param  $body   String where to look for the next tag.
1066  * @param  $offset Start looking from here.
1067  * @return         false if no more tags exist in the body, or
1068  *                 an array with the following members:
1069  *                 - string with the name of the tag
1070  *                 - array with attributes and their values
1071  *                 - integer with tag type (1, 2, or 3)
1072  *                 - integer where the tag starts (starting "<")
1073  *                 - integer where the tag ends (ending ">")
1074  *                 first three members will be false, if the tag is invalid.
1075  */
1076 function sq_getnxtag($body, $offset){
1077     $me = 'sq_getnxtag';
1078     if ($offset > strlen($body)){
1079         return false;
1080     }
1081     $lt = sq_findnxstr($body, $offset, "<");
1082     if ($lt == strlen($body)){
1083         return false;
1084     }
1085     /**
1086      * We are here:
1087      * blah blah <tag attribute="value">
1088      * \---------^
1089      */
1090     $pos = sq_skipspace($body, $lt+1);
1091     if ($pos >= strlen($body)){
1092         return Array(false, false, false, $lt, strlen($body));
1093     }
1094     /**
1095      * There are 3 kinds of tags:
1096      * 1. Opening tag, e.g.:
1097      *    <a href="blah">
1098      * 2. Closing tag, e.g.:
1099      *    </a>
1100      * 3. XHTML-style content-less tag, e.g.:
1101      *    <img src="blah" />
1102      */
1103     $tagtype = false;
1104     switch (substr($body, $pos, 1)){
1105         case '/':
1106             $tagtype = 2;
1107             $pos++;
1108             break;
1109         case '!':
1110             /**
1111              * A comment or an SGML declaration.
1112              */
1113             if (substr($body, $pos+1, 2) == "--"){
1114                 $gt = strpos($body, "-->", $pos);
1115                 if ($gt === false){
1116                     $gt = strlen($body);
1117                 } else {
1118                     $gt += 2;
1119                 }
1120                 return Array(false, false, false, $lt, $gt);
1121             } else {
1122                 $gt = sq_findnxstr($body, $pos, ">");
1123                 return Array(false, false, false, $lt, $gt);
1124             }
1125             break;
1126         default:
1127             /**
1128              * Assume tagtype 1 for now. If it's type 3, we'll switch values
1129              * later.
1130              */
1131             $tagtype = 1;
1132             break;
1133     }
1134
1135     $tagname = '';
1136     /**
1137      * Look for next [\W-_], which will indicate the end of the tag name.
1138      */
1139     $regary = sq_findnxreg($body, $pos, "[^\w\-_]");
1140     if ($regary == false){
1141         return Array(false, false, false, $lt, strlen($body));
1142     }
1143     list($pos, $tagname, $match) = $regary;
1144     $tagname = strtolower($tagname);
1145
1146     /**
1147      * $match can be either of these:
1148      * '>'  indicating the end of the tag entirely.
1149      * '\s' indicating the end of the tag name.
1150      * '/'  indicating that this is type-3 xhtml tag.
1151      *
1152      * Whatever else we find there indicates an invalid tag.
1153      */
1154     switch ($match){
1155         case '/':
1156             /**
1157              * This is an xhtml-style tag with a closing / at the
1158              * end, like so: <img src="blah" />. Check if it's followed
1159              * by the closing bracket. If not, then this tag is invalid
1160              */
1161             if (substr($body, $pos, 2) == "/>"){
1162                 $pos++;
1163                 $tagtype = 3;
1164             } else {
1165                 $gt = sq_findnxstr($body, $pos, ">");
1166                 $retary = Array(false, false, false, $lt, $gt);
1167                 return $retary;
1168             }
1169         case '>':
1170             return Array($tagname, false, $tagtype, $lt, $pos);
1171             break;
1172         default:
1173             /**
1174              * Check if it's whitespace
1175              */
1176             if (!preg_match('/\s/', $match)){
1177                 /**
1178                  * This is an invalid tag! Look for the next closing ">".
1179                  */
1180                 $gt = sq_findnxstr($body, $lt, ">");
1181                 return Array(false, false, false, $lt, $gt);
1182             }
1183             break;
1184     }
1185
1186     /**
1187      * At this point we're here:
1188      * <tagname  attribute='blah'>
1189      * \-------^
1190      *
1191      * At this point we loop in order to find all attributes.
1192      */
1193     $attname = '';
1194     $attary = Array();
1195
1196     while ($pos <= strlen($body)){
1197         $pos = sq_skipspace($body, $pos);
1198         if ($pos == strlen($body)){
1199             /**
1200              * Non-closed tag.
1201              */
1202             return Array(false, false, false, $lt, $pos);
1203         }
1204         /**
1205          * See if we arrived at a ">" or "/>", which means that we reached
1206          * the end of the tag.
1207          */
1208         $matches = Array();
1209         if (preg_match("%^(\s*)(>|/>)%s", substr($body, $pos), $matches)) {
1210             /**
1211              * Yep. So we did.
1212              */
1213             $pos += strlen($matches{1});
1214             if ($matches{2} == "/>"){
1215                 $tagtype = 3;
1216                 $pos++;
1217             }
1218             return Array($tagname, $attary, $tagtype, $lt, $pos);
1219         }
1220
1221         /**
1222          * There are several types of attributes, with optional
1223          * [:space:] between members.
1224          * Type 1:
1225          *   attrname[:space:]=[:space:]'CDATA'
1226          * Type 2:
1227          *   attrname[:space:]=[:space:]"CDATA"
1228          * Type 3:
1229          *   attr[:space:]=[:space:]CDATA
1230          * Type 4:
1231          *   attrname
1232          *
1233          * We leave types 1 and 2 the same, type 3 we check for
1234          * '"' and convert to "&quot" if needed, then wrap in
1235          * double quotes. Type 4 we convert into:
1236          * attrname="yes".
1237          */
1238         $regary = sq_findnxreg($body, $pos, "[^:\w\-_]");
1239         if ($regary == false){
1240             /**
1241              * Looks like body ended before the end of tag.
1242              */
1243             return Array(false, false, false, $lt, strlen($body));
1244         }
1245         list($pos, $attname, $match) = $regary;
1246         $attname = strtolower($attname);
1247         /**
1248          * We arrived at the end of attribute name. Several things possible
1249          * here:
1250          * '>'  means the end of the tag and this is attribute type 4
1251          * '/'  if followed by '>' means the same thing as above
1252          * '\s' means a lot of things -- look what it's followed by.
1253          *      anything else means the attribute is invalid.
1254          */
1255         switch($match){
1256             case '/':
1257                 /**
1258                  * This is an xhtml-style tag with a closing / at the
1259                  * end, like so: <img src="blah" />. Check if it's followed
1260                  * by the closing bracket. If not, then this tag is invalid
1261                  */
1262                 if (substr($body, $pos, 2) == "/>"){
1263                     $pos++;
1264                     $tagtype = 3;
1265                 } else {
1266                     $gt = sq_findnxstr($body, $pos, ">");
1267                     $retary = Array(false, false, false, $lt, $gt);
1268                     return $retary;
1269                 }
1270             case '>':
1271                 $attary{$attname} = '"yes"';
1272                 return Array($tagname, $attary, $tagtype, $lt, $pos);
1273                 break;
1274             default:
1275                 /**
1276                  * Skip whitespace and see what we arrive at.
1277                  */
1278                 $pos = sq_skipspace($body, $pos);
1279                 $char = substr($body, $pos, 1);
1280                 /**
1281                  * Two things are valid here:
1282                  * '=' means this is attribute type 1 2 or 3.
1283                  * \w means this was attribute type 4.
1284                  * anything else we ignore and re-loop. End of tag and
1285                  * invalid stuff will be caught by our checks at the beginning
1286                  * of the loop.
1287                  */
1288                 if ($char == "="){
1289                     $pos++;
1290                     $pos = sq_skipspace($body, $pos);
1291                     /**
1292                      * Here are 3 possibilities:
1293                      * "'"  attribute type 1
1294                      * '"'  attribute type 2
1295                      * everything else is the content of tag type 3
1296                      */
1297                     $quot = substr($body, $pos, 1);
1298                     if ($quot == "'"){
1299                         $regary = sq_findnxreg($body, $pos+1, "\'");
1300                         if ($regary == false){
1301                             return Array(false, false, false, $lt, strlen($body));
1302                         }
1303                         list($pos, $attval, $match) = $regary;
1304                         $pos++;
1305                         $attary{$attname} = "'" . $attval . "'";
1306                     } else if ($quot == '"'){
1307                         $regary = sq_findnxreg($body, $pos+1, '\"');
1308                         if ($regary == false){
1309                             return Array(false, false, false, $lt, strlen($body));
1310                         }
1311                         list($pos, $attval, $match) = $regary;
1312                         $pos++;
1313                         $attary{$attname} = '"' . $attval . '"';
1314                     } else {
1315                         /**
1316                          * These are hateful. Look for \s, or >.
1317                          */
1318                         $regary = sq_findnxreg($body, $pos, "[\s>]");
1319                         if ($regary == false){
1320                             return Array(false, false, false, $lt, strlen($body));
1321                         }
1322                         list($pos, $attval, $match) = $regary;
1323                         /**
1324                          * If it's ">" it will be caught at the top.
1325                          */
1326                         $attval = preg_replace("/\"/s", "&quot;", $attval);
1327                         $attary{$attname} = '"' . $attval . '"';
1328                     }
1329                 } else if (preg_match("|[\w/>]|", $char)) {
1330                     /**
1331                      * That was attribute type 4.
1332                      */
1333                     $attary{$attname} = '"yes"';
1334                 } else {
1335                     /**
1336                      * An illegal character. Find next '>' and return.
1337                      */
1338                     $gt = sq_findnxstr($body, $pos, ">");
1339                     return Array(false, false, false, $lt, $gt);
1340                 }
1341                 break;
1342         }
1343     }
1344     /**
1345      * The fact that we got here indicates that the tag end was never
1346      * found. Return invalid tag indication so it gets stripped.
1347      */
1348     return Array(false, false, false, $lt, strlen($body));
1349 }
1350
1351 /**
1352  * This function checks attribute values for entity-encoded values
1353  * and returns them translated into 8-bit strings so we can run
1354  * checks on them.
1355  *
1356  * @param  $attvalue A string to run entity check against.
1357  * @return           Translated value.
1358  */
1359
1360 function sq_deent($attvalue){
1361     $me = 'sq_deent';
1362     /**
1363      * See if we have to run the checks first. All entities must start
1364      * with "&".
1365      */
1366     if (strpos($attvalue, '&') === false){
1367         return $attvalue;
1368     }
1369     /**
1370      * Check named entities first.
1371      */
1372     $trans = get_html_translation_table(HTML_ENTITIES);
1373     /**
1374      * Leave &quot; in, as it can mess us up.
1375      */
1376     $trans = array_flip($trans);
1377     unset($trans{'&quot;'});
1378     while (list($ent, $val) = each($trans)){
1379         $attvalue = preg_replace('/' . $ent . '*/si', $val, $attvalue);
1380     }
1381     /**
1382      * Now translate numbered entities from 1 to 255 if needed.
1383      */
1384     if (strpos($attvalue, '#') !== false){
1385         $omit = Array(34, 39);
1386         for ($asc = 256; $asc >= 0; $asc--){
1387             if (!in_array($asc, $omit)){
1388                 $chr = chr($asc);
1389                 $octrule = '/\&#0*' . $asc . ';*/si';
1390                 $hexrule = '/\&#x0*' . dechex($asc) . ';*/si';
1391                 $attvalue = preg_replace($octrule, $chr, $attvalue);
1392                 $attvalue = preg_replace($hexrule, $chr, $attvalue);
1393             }
1394         }
1395     }
1396     return $attvalue;
1397 }
1398
1399 /**
1400  * This function runs various checks against the attributes.
1401  *
1402  * @param  $tagname         String with the name of the tag.
1403  * @param  $attary          Array with all tag attributes.
1404  * @param  $rm_attnames     See description for sq_sanitize
1405  * @param  $bad_attvals     See description for sq_sanitize
1406  * @param  $add_attr_to_tag See description for sq_sanitize
1407  * @param  $message         message object
1408  * @param  $id              message id
1409  * @return                  Array with modified attributes.
1410  */
1411 function sq_fixatts($tagname,
1412                     $attary,
1413                     $rm_attnames,
1414                     $bad_attvals,
1415                     $add_attr_to_tag,
1416                     $message,
1417                     $id,
1418                     $mailbox
1419                     ){
1420     $me = 'sq_fixatts';
1421     while (list($attname, $attvalue) = each($attary)){
1422         /**
1423          * See if this attribute should be removed.
1424          */
1425         foreach ($rm_attnames as $matchtag=>$matchattrs){
1426             if (preg_match($matchtag, $tagname)){
1427                 foreach ($matchattrs as $matchattr){
1428                     if (preg_match($matchattr, $attname)){
1429                         unset($attary{$attname});
1430                         continue;
1431                     }
1432                 }
1433             }
1434         }
1435         /**
1436          * Remove any backslashes, entities, and extraneous whitespace.
1437          */
1438         $attvalue = sq_unbackslash($attvalue);
1439         $attvalue = sq_deent($attvalue);
1440         $attvalue = sq_unspace($attvalue);
1441
1442         /**
1443          * Remove \r \n \t \0 " " "\\"
1444          */
1445         $attvalue = str_replace(Array("\r", "\n", "\t", "\0", " ", "\\"),
1446                         Array('', '','','','',''), $attvalue);
1447
1448         /**
1449          * Now let's run checks on the attvalues.
1450          * I don't expect anyone to comprehend this. If you do,
1451          * get in touch with me so I can drive to where you live and
1452          * shake your hand personally. :)
1453          */
1454         foreach ($bad_attvals as $matchtag=>$matchattrs){
1455             if (preg_match($matchtag, $tagname)){
1456                 foreach ($matchattrs as $matchattr=>$valary){
1457                     if (preg_match($matchattr, $attname)){
1458                         /**
1459                          * There are two arrays in valary.
1460                          * First is matches.
1461                          * Second one is replacements
1462                          */
1463                         list($valmatch, $valrepl) = $valary;
1464                         $newvalue =
1465                             preg_replace($valmatch, $valrepl, $attvalue);
1466                         if ($newvalue != $attvalue){
1467                             $attary{$attname} = $newvalue;
1468                         }
1469                     }
1470                 }
1471             }
1472         }
1473         /**
1474          * Turn cid: urls into http-friendly ones.
1475          */
1476         if (preg_match("/^[\'\"]\s*cid:/si", $attvalue)){
1477             $attary{$attname} = sq_cid2http($message, $id, $attvalue, $mailbox);
1478         }
1479     }
1480     /**
1481      * See if we need to append any attributes to this tag.
1482      */
1483     foreach ($add_attr_to_tag as $matchtag=>$addattary){
1484         if (preg_match($matchtag, $tagname)){
1485             $attary = array_merge($attary, $addattary);
1486         }
1487     }
1488     return $attary;
1489 }
1490
1491 /**
1492  * This function edits the style definition to make them friendly and
1493  * usable in SquirrelMail.
1494  *
1495  * @param  $message  the message object
1496  * @param  $id       the message id
1497  * @param  $content  a string with whatever is between <style> and </style>
1498  * @param  $mailbox  the message mailbox
1499  * @return           a string with edited content.
1500  */
1501 function sq_fixstyle($body, $pos, $message, $id, $mailbox){
1502     global $view_unsafe_images;
1503     $me = 'sq_fixstyle';
1504     $ret = sq_findnxreg($body, $pos, '</\s*style\s*>');
1505     if ($ret == FALSE){
1506         return array(FALSE, strlen($body));
1507     }
1508     $newpos = $ret[0] + strlen($ret[2]);
1509     $content = $ret[1];
1510     /**
1511      * First look for general BODY style declaration, which would be
1512      * like so:
1513      * body {background: blah-blah}
1514      * and change it to .bodyclass so we can just assign it to a <div>
1515      */
1516     $content = preg_replace("|body(\s*\{.*?\})|si", ".bodyclass\\1", $content);
1517     $secremoveimg = '../images/' . _("sec_remove_eng.png");
1518     /**
1519      * Fix url('blah') declarations.
1520      */
1521     $content = preg_replace("|url\s*\(\s*([\'\"])\s*\S+script\s*:.*?([\'\"])\s*\)|si",
1522                             "url(\\1$secremoveimg\\2)", $content);
1523     /**
1524      * Fix url('https*://.*) declarations but only if $view_unsafe_images
1525      * is false.
1526      */
1527     if (!$view_unsafe_images){
1528         $content = preg_replace("|url\s*\(\s*([\'\"])\s*https*:.*?([\'\"])\s*\)|si",
1529                                 "url(\\1$secremoveimg\\2)", $content);
1530     }
1531
1532     /**
1533      * Fix urls that refer to cid:
1534      */
1535     while (preg_match("|url\s*\(\s*([\'\"]\s*cid:.*?[\'\"])\s*\)|si",
1536                       $content, $matches)){
1537         $cidurl = $matches{1};
1538         $httpurl = sq_cid2http($message, $id, $cidurl, $mailbox);
1539         $content = preg_replace("|url\s*\(\s*$cidurl\s*\)|si",
1540                                 "url($httpurl)", $content);
1541     }
1542
1543     /**
1544      * Fix stupid css declarations which lead to vulnerabilities
1545      * in IE.
1546      */
1547     $match   = Array('/expression/i',
1548                      '/behaviou*r/i',
1549                      '/binding/i',
1550                      '/include-source/i');
1551     $replace = Array('idiocy', 'idiocy', 'idiocy', 'idiocy');
1552     $content = preg_replace($match, $replace, $content);
1553     return array($content, $newpos);
1554 }
1555
1556 /**
1557  * This function converts cid: url's into the ones that can be viewed in
1558  * the browser.
1559  *
1560  * @param  $message  the message object
1561  * @param  $id       the message id
1562  * @param  $cidurl   the cid: url.
1563  * @param  $mailbox  the message mailbox
1564  * @return           a string with a http-friendly url
1565  */
1566 function sq_cid2http($message, $id, $cidurl, $mailbox){
1567     /**
1568      * Get rid of quotes.
1569      */
1570     $quotchar = substr($cidurl, 0, 1);
1571     if ($quotchar == '"' || $quotchar == "'"){
1572         $cidurl = str_replace($quotchar, "", $cidurl);
1573     } else {
1574         $quotchar = '';
1575     }
1576     $cidurl = substr(trim($cidurl), 4);
1577     $linkurl = find_ent_id($cidurl, $message);
1578     /* in case of non-save cid links $httpurl should be replaced by a sort of
1579        unsave link image */
1580     $httpurl = '';
1581     if ($linkurl) {
1582         $httpurl = $quotchar . SM_PATH . 'src/download.php?absolute_dl=true&amp;' .
1583                    "passed_id=$id&amp;mailbox=" . urlencode($mailbox) .
1584                    '&amp;ent_id=' . $linkurl . $quotchar;
1585     }
1586     return $httpurl;
1587 }
1588
1589 /**
1590  * This function changes the <body> tag into a <div> tag since we
1591  * can't really have a body-within-body.
1592  *
1593  * @param  $attary   an array of attributes and values of <body>
1594  * @param  $mailbox  mailbox we're currently reading (for cid2http)
1595  * @param  $message  current message (for cid2http)
1596  * @param  $id       current message id (for cid2http)
1597  * @return           a modified array of attributes to be set for <div>
1598  */
1599 function sq_body2div($attary, $mailbox, $message, $id){
1600     $me = 'sq_body2div';
1601     $divattary = Array('class' => "'bodyclass'");
1602     $text = '#000000';
1603     $has_bgc_stl = $has_txt_stl = false;
1604     $styledef = '';
1605     if (is_array($attary) && sizeof($attary) > 0){
1606         foreach ($attary as $attname=>$attvalue){
1607             $quotchar = substr($attvalue, 0, 1);
1608             $attvalue = str_replace($quotchar, "", $attvalue);
1609             switch ($attname){
1610                 case 'background':
1611                     $attvalue = sq_cid2http($message, $id,
1612                                             $attvalue, $mailbox);
1613                     $styledef .= "background-image: url('$attvalue'); ";
1614                     break;
1615                 case 'bgcolor':
1616                     $has_bgc_stl = true;
1617                     $styledef .= "background-color: $attvalue; ";
1618                     break;
1619                 case 'text':
1620                     $has_txt_stl = true;
1621                     $styledef .= "color: $attvalue; ";
1622                     break;
1623             }
1624         }
1625         // Outlook defines a white bgcolor and no text color. This can lead to
1626         // white text on a white bg with certain themes.
1627         if ($has_bgc_stl && !$has_txt_stl) {
1628             $styledef .= "color: $text; ";
1629         }
1630         if (strlen($styledef) > 0){
1631             $divattary{"style"} = "\"$styledef\"";
1632         }
1633     }
1634     return $divattary;
1635 }
1636
1637 /**
1638  * This is the main function and the one you should actually be calling.
1639  * There are several variables you should be aware of an which need
1640  * special description.
1641  *
1642  * Since the description is quite lengthy, see it here:
1643  * http://linux.duke.edu/projects/mini/htmlfilter/
1644  *
1645  * @param $body                 the string with HTML you wish to filter
1646  * @param $tag_list             see description above
1647  * @param $rm_tags_with_content see description above
1648  * @param $self_closing_tags    see description above
1649  * @param $force_tag_closing    see description above
1650  * @param $rm_attnames          see description above
1651  * @param $bad_attvals          see description above
1652  * @param $add_attr_to_tag      see description above
1653  * @param $message              message object
1654  * @param $id                   message id
1655  * @return                      sanitized html safe to show on your pages.
1656  */
1657 function sq_sanitize($body,
1658                      $tag_list,
1659                      $rm_tags_with_content,
1660                      $self_closing_tags,
1661                      $force_tag_closing,
1662                      $rm_attnames,
1663                      $bad_attvals,
1664                      $add_attr_to_tag,
1665                      $message,
1666                      $id,
1667                      $mailbox
1668                      ){
1669     $me = 'sq_sanitize';
1670     $rm_tags = array_shift($tag_list);
1671     /**
1672      * Normalize rm_tags and rm_tags_with_content.
1673      */
1674     @array_walk($tag_list, 'sq_casenormalize');
1675     @array_walk($rm_tags_with_content, 'sq_casenormalize');
1676     @array_walk($self_closing_tags, 'sq_casenormalize');
1677     /**
1678      * See if tag_list is of tags to remove or tags to allow.
1679      * false  means remove these tags
1680      * true   means allow these tags
1681      */
1682     $curpos = 0;
1683     $open_tags = Array();
1684     $trusted = "\n<!-- begin sanitized html -->\n";
1685     $skip_content = false;
1686     /**
1687      * Take care of netscape's stupid javascript entities like
1688      * &{alert('boo')};
1689      */
1690     $body = preg_replace("/&(\{.*?\};)/si", "&amp;\\1", $body);
1691
1692     while (($curtag = sq_getnxtag($body, $curpos)) != FALSE){
1693         list($tagname, $attary, $tagtype, $lt, $gt) = $curtag;
1694         $free_content = substr($body, $curpos, $lt-$curpos);
1695         /**
1696          * Take care of <style>
1697          */
1698         if ($tagname == "style" && $tagtype == 1){
1699             list($free_content, $curpos) =
1700                 sq_fixstyle($body, $gt+1, $message, $id, $mailbox);
1701             if ($free_content != FALSE){
1702                 $trusted .= sq_tagprint($tagname, $attary, $tagtype);
1703                 $trusted .= $free_content;
1704                 $trusted .= sq_tagprint($tagname, false, 2);
1705             }
1706             continue;
1707         }
1708         if ($skip_content == false){
1709             $trusted .= $free_content;
1710         }
1711         if ($tagname != FALSE){
1712             if ($tagtype == 2){
1713                 if ($skip_content == $tagname){
1714                     /**
1715                      * Got to the end of tag we needed to remove.
1716                      */
1717                     $tagname = false;
1718                     $skip_content = false;
1719                 } else {
1720                     if ($skip_content == false){
1721                         if ($tagname == "body"){
1722                             $tagname = "div";
1723                         }
1724                         if (isset($open_tags{$tagname}) &&
1725                             $open_tags{$tagname} > 0){
1726                             $open_tags{$tagname}--;
1727                         } else {
1728                             $tagname = false;
1729                         }
1730                     }
1731                 }
1732             } else {
1733                 /**
1734                  * $rm_tags_with_content
1735                  */
1736                 if ($skip_content == false){
1737                     /**
1738                      * See if this is a self-closing type and change
1739                      * tagtype appropriately.
1740                      */
1741                     if ($tagtype == 1
1742                         && in_array($tagname, $self_closing_tags)){
1743                         $tagtype = 3;
1744                     }
1745                     /**
1746                      * See if we should skip this tag and any content
1747                      * inside it.
1748                      */
1749                     if ($tagtype == 1 &&
1750                         in_array($tagname, $rm_tags_with_content)){
1751                         $skip_content = $tagname;
1752                     } else {
1753                         if (($rm_tags == false
1754                              && in_array($tagname, $tag_list)) ||
1755                             ($rm_tags == true &&
1756                              !in_array($tagname, $tag_list))){
1757                             $tagname = false;
1758                         } else {
1759                             /**
1760                              * Convert body into div.
1761                              */
1762                             if ($tagname == "body"){
1763                                 $tagname = "div";
1764                                 $attary = sq_body2div($attary, $mailbox,
1765                                                       $message, $id);
1766                             }
1767                             if ($tagtype == 1){
1768                                 if (isset($open_tags{$tagname})){
1769                                     $open_tags{$tagname}++;
1770                                 } else {
1771                                     $open_tags{$tagname}=1;
1772                                 }
1773                             }
1774                             /**
1775                              * This is where we run other checks.
1776                              */
1777                             if (is_array($attary) && sizeof($attary) > 0){
1778                                 $attary = sq_fixatts($tagname,
1779                                                      $attary,
1780                                                      $rm_attnames,
1781                                                      $bad_attvals,
1782                                                      $add_attr_to_tag,
1783                                                      $message,
1784                                                      $id,
1785                                                      $mailbox
1786                                                      );
1787                             }
1788                         }
1789                     }
1790                 }
1791             }
1792             if ($tagname != false && $skip_content == false){
1793                 $trusted .= sq_tagprint($tagname, $attary, $tagtype);
1794             }
1795         }
1796         $curpos = $gt+1;
1797     }
1798     $trusted .= substr($body, $curpos, strlen($body)-$curpos);
1799     if ($force_tag_closing == true){
1800         foreach ($open_tags as $tagname=>$opentimes){
1801             while ($opentimes > 0){
1802                 $trusted .= '</' . $tagname . '>';
1803                 $opentimes--;
1804             }
1805         }
1806         $trusted .= "\n";
1807     }
1808     $trusted .= "<!-- end sanitized html -->\n";
1809     return $trusted;
1810 }
1811
1812 /**
1813  * This is a wrapper function to call html sanitizing routines.
1814  *
1815  * @param  $body  the body of the message
1816  * @param  $id    the id of the message
1817  * @return        a string with html safe to display in the browser.
1818  */
1819 function magicHTML($body, $id, $message, $mailbox = 'INBOX') {
1820     global $attachment_common_show_images, $view_unsafe_images,
1821            $has_unsafe_images;
1822     /**
1823      * Don't display attached images in HTML mode.
1824      */
1825     $attachment_common_show_images = false;
1826     $tag_list = Array(
1827                       false,
1828                       "object",
1829                       "meta",
1830                       "html",
1831                       "head",
1832                       "base",
1833                       "link",
1834                       "frame",
1835                       "iframe",
1836                       "plaintext",
1837                       "marquee"
1838                       );
1839
1840     $rm_tags_with_content = Array(
1841                                   "script",
1842                                   "applet",
1843                                   "embed",
1844                                   "title",
1845                                   "frameset",
1846                                   "xml"
1847                                   );
1848
1849     $self_closing_tags =  Array(
1850                                 "img",
1851                                 "br",
1852                                 "hr",
1853                                 "input"
1854                                 );
1855
1856     $force_tag_closing = true;
1857
1858     $rm_attnames = Array(
1859                          "/.*/" =>
1860                          Array(
1861                                "/target/i",
1862                                "/^on.*/i",
1863                                "/^dynsrc/i",
1864                                "/^data.*/i",
1865                                "/^lowsrc.*/i"
1866                                )
1867                          );
1868
1869     $secremoveimg = "../images/" . _("sec_remove_eng.png");
1870     $bad_attvals = Array(
1871         "/.*/" =>
1872             Array(
1873                 "/^src|background/i" =>
1874                     Array(
1875                           Array(
1876                                 "/^([\'\"])\s*\S+script\s*:.*([\'\"])/si",
1877                                 "/^([\'\"])\s*mocha\s*:*.*([\'\"])/si",
1878                                 "/^([\'\"])\s*about\s*:.*([\'\"])/si"
1879                                 ),
1880                           Array(
1881                                 "\\1$secremoveimg\\2",
1882                                 "\\1$secremoveimg\\2",
1883                                 "\\1$secremoveimg\\2",
1884                                 "\\1$secremoveimg\\2"
1885                                 )
1886                         ),
1887                 "/^href|action/i" =>
1888                     Array(
1889                           Array(
1890                                 "/^([\'\"])\s*\S+script\s*:.*([\'\"])/si",
1891                                 "/^([\'\"])\s*mocha\s*:*.*([\'\"])/si",
1892                                 "/^([\'\"])\s*about\s*:.*([\'\"])/si"
1893                                 ),
1894                           Array(
1895                                 "\\1#\\1",
1896                                 "\\1#\\1",
1897                                 "\\1#\\1",
1898                                 "\\1#\\1"
1899                                 )
1900                         ),
1901                 "/^style/i" =>
1902                     Array(
1903                           Array(
1904                                 "/expression/i",
1905                                 "/binding/i",
1906                                 "/behaviou*r/i",
1907                                 "/include-source/i",
1908                                 "/url\s*\(\s*([\'\"])\s*\S+script\s*:.*([\'\"])\s*\)/si",
1909                                 "/url\s*\(\s*([\'\"])\s*mocha\s*:.*([\'\"])\s*\)/si",
1910                                 "/url\s*\(\s*([\'\"])\s*about\s*:.*([\'\"])\s*\)/si",
1911                                 "/(.*)\s*:\s*url\s*\(\s*([\'\"]*)\s*\S+script\s*:.*([\'\"]*)\s*\)/si"
1912                                ),
1913                           Array(
1914                                 "idiocy",
1915                                 "idiocy",
1916                                 "idiocy",
1917                                 "idiocy",
1918                                 "url(\\1#\\1)",
1919                                 "url(\\1#\\1)",
1920                                 "url(\\1#\\1)",
1921                                 "url(\\1#\\1)",
1922                                 "\\1:url(\\2#\\3)"
1923                                )
1924                           )
1925                 )
1926         );
1927     if( !sqgetGlobalVar('view_unsafe_images', $view_unsafe_images, SQ_GET) ) {
1928         $view_unsafe_images = false;
1929     }
1930     if (!$view_unsafe_images){
1931         /**
1932          * Remove any references to http/https if view_unsafe_images set
1933          * to false.
1934          */
1935          array_push($bad_attvals{'/.*/'}{'/^src|background/i'}[0],
1936                     '/^([\'\"])\s*https*:.*([\'\"])/si');
1937          array_push($bad_attvals{'/.*/'}{'/^src|background/i'}[1],
1938                     "\\1$secremoveimg\\1");
1939          array_push($bad_attvals{'/.*/'}{'/^style/i'}[0],
1940                     '/url\(([\'\"])\s*https*:.*([\'\"])\)/si');
1941          array_push($bad_attvals{'/.*/'}{'/^style/i'}[1],
1942                     "url(\\1$secremoveimg\\1)");
1943     }
1944
1945     $add_attr_to_tag = Array(
1946         "/^a$/i" =>
1947             Array('target'=>'"_new"',
1948                   'title'=>'"'._("This external link will open in a new window").'"'
1949             )
1950     );
1951     $trusted = sq_sanitize($body,
1952                            $tag_list,
1953                            $rm_tags_with_content,
1954                            $self_closing_tags,
1955                            $force_tag_closing,
1956                            $rm_attnames,
1957                            $bad_attvals,
1958                            $add_attr_to_tag,
1959                            $message,
1960                            $id,
1961                            $mailbox
1962                            );
1963     if (preg_match("|$secremoveimg|i", $trusted)){
1964         $has_unsafe_images = true;
1965     }
1966     return $trusted;
1967 }
1968
1969 /**
1970  * function SendDownloadHeaders - send file to the browser
1971  *
1972  * Original Source: SM core src/download.php
1973  * moved here to make it available to other code, and separate
1974  * front end from back end functionality.
1975  *
1976  * @param string $type0 first half of mime type
1977  * @param string $type1 second half of mime type
1978  * @param string $filename filename to tell the browser for downloaded file
1979  * @param boolean $force whether to force the download dialog to pop
1980  * @param optional integer $filesize send the Content-Header and length to the browser
1981  * @return void
1982  */
1983  function SendDownloadHeaders($type0, $type1, $filename, $force, $filesize=0) {
1984      global $languages, $squirrelmail_language;
1985      $isIE = $isIE6 = 0;
1986
1987      sqgetGlobalVar('HTTP_USER_AGENT', $HTTP_USER_AGENT, SQ_SERVER);
1988
1989      if (strstr($HTTP_USER_AGENT, 'compatible; MSIE ') !== false &&
1990          strstr($HTTP_USER_AGENT, 'Opera') === false) {
1991          $isIE = 1;
1992      }
1993
1994      if (strstr($HTTP_USER_AGENT, 'compatible; MSIE 6') !== false &&
1995          strstr($HTTP_USER_AGENT, 'Opera') === false) {
1996          $isIE6 = 1;
1997      }
1998
1999      if (isset($languages[$squirrelmail_language]['XTRA_CODE']) &&
2000          function_exists($languages[$squirrelmail_language]['XTRA_CODE'] . '_downloadfilename')) {
2001          $filename =
2002          call_user_func($languages[$squirrelmail_language]['XTRA_CODE'] . '_downloadfilename', $filename, $HTTP_USER_AGENT);
2003      } else {
2004          $filename = ereg_replace('[\\/:\*\?"<>\|;]', '_', str_replace('&nbsp;', ' ', $filename));
2005      }
2006
2007      // A Pox on Microsoft and it's Internet Explorer!
2008      //
2009      // IE has lots of bugs with file downloads.
2010      // It also has problems with SSL.  Both of these cause problems
2011      // for us in this function.
2012      //
2013      // See this article on Cache Control headers and SSL
2014      // http://support.microsoft.com/default.aspx?scid=kb;en-us;323308
2015      //
2016      // The best thing you can do for IE is to upgrade to the latest
2017      // version
2018      //set all the Cache Control Headers for IE
2019      if ($isIE) {
2020          $filename=rawurlencode($filename);
2021          header ("Pragma: public");
2022          header ("Cache-Control: no-store, max-age=0, no-cache, must-revalidate"); # HTTP/1.1
2023          header ("Cache-Control: post-check=0, pre-check=0", false);
2024          header ("Cache-control: private");
2025
2026          //set the inline header for IE, we'll add the attachment header later if we need it
2027          header ("Content-Disposition: inline; filename=$filename");
2028      }
2029
2030      if (!$force) {
2031          // Try to show in browser window
2032          header ("Content-Disposition: inline; filename=\"$filename\"");
2033          header ("Content-Type: $type0/$type1; name=\"$filename\"");
2034      } else {
2035          // Try to pop up the "save as" box
2036
2037          // IE makes this hard.  It pops up 2 save boxes, or none.
2038          // http://support.microsoft.com/support/kb/articles/Q238/5/88.ASP
2039          // http://support.microsoft.com/default.aspx?scid=kb;EN-US;260519
2040          // But, according to Microsoft, it is "RFC compliant but doesn't
2041          // take into account some deviations that allowed within the
2042          // specification."  Doesn't that mean RFC non-compliant?
2043          // http://support.microsoft.com/support/kb/articles/Q258/4/52.ASP
2044
2045          // all browsers need the application/octet-stream header for this
2046          header ("Content-Type: application/octet-stream; name=\"$filename\"");
2047
2048          // http://support.microsoft.com/support/kb/articles/Q182/3/15.asp
2049          // Do not have quotes around filename, but that applied to
2050          // "attachment"... does it apply to inline too?
2051          header ("Content-Disposition: attachment; filename=\"$filename\"");
2052
2053          if ($isIE && !$isIE6) {
2054              // This combination seems to work mostly.  IE 5.5 SP 1 has
2055              // known issues (see the Microsoft Knowledge Base)
2056
2057              // This works for most types, but doesn't work with Word files
2058              header ("Content-Type: application/download; name=\"$filename\"");
2059
2060              // These are spares, just in case.  :-)
2061              //header("Content-Type: $type0/$type1; name=\"$filename\"");
2062              //header("Content-Type: application/x-msdownload; name=\"$filename\"");
2063              //header("Content-Type: application/octet-stream; name=\"$filename\"");
2064          } else {
2065              // another application/octet-stream forces download for Netscape
2066              header ("Content-Type: application/octet-stream; name=\"$filename\"");
2067          }
2068      }
2069
2070      //send the content-length header if the calling function provides it
2071      if ($filesize > 0) {
2072          header("Content-Length: $filesize");
2073      }
2074
2075 }  // end fn SendDownloadHeaders
2076
2077 ?>