functions/mime.php

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