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, $encoding) {
 161
 162     /* Don't kill the connection if the browser is over a dialup
 163      * and it would take over 30 seconds to download it.
 164      * Don't call set_time_limit in safe mode.
 165      */
 166
 167     if (!ini_get('safe_mode')) {
 168         set_time_limit(0);
 169     }
 170     /* in case of base64 encoded attachments, do not buffer them.
 171        Instead, echo the decoded attachment directly to screen */
 172     if (strtolower($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);
 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[$squirrelmail_language]['XTRA_CODE'] . '_decode')) {
 362             if (mb_detect_encoding($body) != 'ASCII') {
 363                 $body = call_user_func($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, $passed_ent_id;
 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
 510         /* This executes the attachment hook with a specific MIME-type.
 511          * If that doesn't have results, it tries if there's a rule
 512          * for a more generic type.
 513          */
 514         $hookresults = do_hook("attachment $type0/$type1", $links,
 515                                $startMessage, $id, $urlMailbox, $ent, $defaultlink,
 516                                $display_filename, $where, $what);
 517         if(count($hookresults[1]) <= 1) {
 518             $hookresults = do_hook("attachment $type0/*", $links,
 519                                    $startMessage, $id, $urlMailbox, $ent, $defaultlink,
 520                                    $display_filename, $where, $what);
 521         }
 522
 523         $links = $hookresults[1];
 524         $defaultlink = $hookresults[6];
 525
 526         $attachments .= '<tr><td>' .
 527                         '<a href="'.$defaultlink.'">'.decodeHeader($display_filename).'</a>&nbsp;</td>' .
 528                         '<td><small><b>' . show_readable_size($header->size) .
 529                         '</b>&nbsp;&nbsp;</small></td>' .
 530                         '<td><small>[ '.htmlspecialchars($type0).'/'.htmlspecialchars($type1).' ]&nbsp;</small></td>' .
 531                         '<td><small>';
 532         $attachments .= '<b>' . $description . '</b>';
 533         $attachments .= '</small></td><td><small>&nbsp;';
 534
 535         $skipspaces = 1;
 536         foreach ($links as $val) {
 537             if ($skipspaces) {
 538                 $skipspaces = 0;
 539             } else {
 540                 $attachments .= '&nbsp;&nbsp;|&nbsp;&nbsp;';
 541             }
 542             $attachments .= '<a href="' . $val['href'] . '">' .  $val['text'] . '</a>';
 543         }
 544         unset($links);
 545         $attachments .= "</td></tr>\n";
 546     }
 547     $attachmentadd = do_hook_function('attachments_bottom',$attachments);
 548     if ($attachmentadd != '')
 549         $attachments = $attachmentadd;
 550     return $attachments;
 551 }
 552
 553 function sqimap_base64_decode(&$string) {
 554
 555     // Base64 encoded data goes in pairs of 4 bytes. To achieve on the
 556     // fly decoding (to reduce memory usage) you have to check if the
 557     // data has incomplete pairs
 558
 559     // Remove the noise in order to check if the 4 bytes pairs are complete
 560     $string = str_replace(array("\r\n","\n", "\r", " "),array('','','',''),$string);
 561
 562     $sStringRem = '';
 563     $iMod = strlen($string) % 4;
 564     if ($iMod) {
 565         $sStringRem = substr($string,-$iMod);
 566         // Check if $sStringRem contains padding characters
 567         if (substr($sStringRem,-1) != '=') {
 568             $string = substr($string,0,-$iMod);
 569         } else {
 570             $sStringRem = '';
 571         }
 572     }
 573     $string = base64_decode($string);
 574     return $sStringRem;
 575 }
 576
 577
 578 /* This function decodes the body depending on the encoding type. */
 579 function decodeBody($body, $encoding) {
 580     global $show_html_default;
 581
 582     $body = str_replace("\r\n", "\n", $body);
 583     $encoding = strtolower($encoding);
 584
 585     $encoding_handler = do_hook_function('decode_body', $encoding);
 586
 587
 588     // plugins get first shot at decoding the body
 589     //
 590     if (!empty($encoding_handler) && function_exists($encoding_handler)) {
 591         $body = $encoding_handler('decode', $body);
 592
 593     } else if ($encoding == 'quoted-printable' ||
 594         $encoding == 'quoted_printable') {
 595         $body = quoted_printable_decode($body);
 596
 597         while (ereg("=\n", $body)) {
 598             $body = ereg_replace ("=\n", '', $body);
 599         }
 600
 601     } else if ($encoding == 'base64') {
 602         $body = base64_decode($body);
 603     }
 604
 605     // All other encodings are returned raw.
 606     return $body;
 607 }
 608
 609 /**
 610  * Decodes headers
 611  *
 612  * This functions decode strings that is encoded according to
 613  * RFC1522 (MIME Part Two: Message Header Extensions for Non-ASCII Text).
 614  * Patched by Christian Schmidt <christian@ostenfeld.dk>  23/03/2002
 615  *
 616  * @param string $string header string that has to be made readable
 617  * @param boolean $utfencode change message in order to be readable on user's charset. defaults to true
 618  * @param boolean $htmlsave preserve spaces and sanitize html special characters. defaults to true
 619  * @param boolean $decide decide if string can be utfencoded. defaults to false
 620  * @return string decoded header string
 621  */
 622 function decodeHeader ($string, $utfencode=true,$htmlsave=true,$decide=false) {
 623     global $languages, $squirrelmail_language,$default_charset;
 624     if (is_array($string)) {
 625         $string = implode("\n", $string);
 626     }
 627
 628     if (isset($languages[$squirrelmail_language]['XTRA_CODE']) &&
 629         function_exists($languages[$squirrelmail_language]['XTRA_CODE'] . '_decodeheader')) {
 630         $string = call_user_func($languages[$squirrelmail_language]['XTRA_CODE'] . '_decodeheader', $string);
 631         // Do we need to return at this point?
 632         // return $string;
 633     }
 634     $i = 0;
 635     $iLastMatch = -2;
 636     $encoded = true;
 637
 638     $aString = explode(' ',$string);
 639     $ret = '';
 640     foreach ($aString as $chunk) {
 641         if ($encoded && $chunk === '') {
 642             continue;
 643         } elseif ($chunk === '') {
 644             $ret .= ' ';
 645             continue;
 646         }
 647         $encoded = false;
 648         /* if encoded words are not separated by a linear-space-white we still catch them */
 649         $j = $i-1;
 650
 651         while ($match = preg_match('/^(.*)=\?([^?]*)\?(Q|B)\?([^?]*)\?=(.*)$/Ui',$chunk,$res)) {
 652             /* if the last chunk isn't an encoded string then put back the space, otherwise don't */
 653             if ($iLastMatch !== $j) {
 654                 if ($htmlsave) {
 655                     $ret .= '&#32;';
 656                 } else {
 657                     $ret .= ' ';
 658                 }
 659             }
 660             $iLastMatch = $i;
 661             $j = $i;
 662             if ($htmlsave) {
 663                 $ret .= htmlspecialchars($res[1]);
 664             } else {
 665                 $ret .= $res[1];
 666             }
 667             $encoding = ucfirst($res[3]);
 668
 669             /* decide about valid decoding */
 670             if ($decide && is_conversion_safe($res[2])) {
 671               $utfencode=true;
 672               $can_be_encoded=true;
 673             } else {
 674               $can_be_encoded=false;
 675             }
 676             switch ($encoding)
 677             {
 678             case 'B':
 679                 $replace = base64_decode($res[4]);
 680                 if ($can_be_encoded) {
 681                   /* convert string to different charset,
 682                    * if functions asks for it (usually in compose)
 683                    */
 684                   $ret .= charset_convert($res[2],$replace,$default_charset);
 685                 } else {
 686                   // convert string to html codes in order to display it
 687                   $ret .= charset_decode($res[2],$replace);
 688                 }
 689                 break;
 690             case 'Q':
 691                 $replace = str_replace('_', ' ', $res[4]);
 692                 $replace = preg_replace('/=([0-9a-f]{2})/ie', 'chr(hexdec("\1"))',
 693                                     $replace);
 694                 if ($utfencode) {
 695                   if ($can_be_encoded) {
 696                     /* convert string to different charset,
 697                      * if functions asks for it (usually in compose)
 698                      */
 699                     $replace = charset_convert($res[2], $replace,$default_charset);
 700                   } else {
 701                     // convert string to html codes in order to display it
 702                     $replace = charset_decode($res[2], $replace);
 703                   }
 704                 } else {
 705                     if ($htmlsave) {
 706                         $replace = htmlspecialchars($replace);
 707                     }
 708                 }
 709                 $ret .= $replace;
 710                 break;
 711             default:
 712                 break;
 713             }
 714             $chunk = $res[5];
 715             $encoded = true;
 716         }
 717         if (!$encoded) {
 718             if ($htmlsave) {
 719                 $ret .= '&#32;';
 720             } else {
 721                 $ret .= ' ';
 722             }
 723         }
 724
 725         if (!$encoded && $htmlsave) {
 726             $ret .= htmlspecialchars($chunk);
 727         } else {
 728             $ret .= $chunk;
 729         }
 730         ++$i;
 731     }
 732     /* remove the first added space */
 733     if ($ret) {
 734         if ($htmlsave) {
 735             $ret = substr($ret,5);
 736         } else {
 737             $ret = substr($ret,1);
 738         }
 739     }
 740
 741     return $ret;
 742 }
 743
 744 /**
 745  * Encodes header as quoted-printable
 746  *
 747  * Encode a string according to RFC 1522 for use in headers if it
 748  * contains 8-bit characters or anything that looks like it should
 749  * be encoded.
 750  *
 751  * @param string $string header string, that has to be encoded
 752  * @return string quoted-printable encoded string
 753  */
 754 function encodeHeader ($string) {
 755     global $default_charset, $languages, $squirrelmail_language;
 756
 757     if (isset($languages[$squirrelmail_language]['XTRA_CODE']) &&
 758         function_exists($languages[$squirrelmail_language]['XTRA_CODE'] . '_encodeheader')) {
 759         return  call_user_func($languages[$squirrelmail_language]['XTRA_CODE'] . '_encodeheader', $string);
 760     }
 761
 762     // Encode only if the string contains 8-bit characters or =?
 763     $j = strlen($string);
 764     $max_l = 75 - strlen($default_charset) - 7;
 765     $aRet = array();
 766     $ret = '';
 767     $iEncStart = $enc_init = false;
 768     $cur_l = $iOffset = 0;
 769     for($i = 0; $i < $j; ++$i) {
 770         switch($string{$i})
 771         {
 772         case '=':
 773         case '<':
 774         case '>':
 775         case ',':
 776         case '?':
 777         case '_':
 778             if ($iEncStart === false) {
 779                 $iEncStart = $i;
 780             }
 781             $cur_l+=3;
 782             if ($cur_l > ($max_l-2)) {
 783                 /* if there is an stringpart that doesn't need encoding, add it */
 784                 $aRet[] = substr($string,$iOffset,$iEncStart-$iOffset);
 785                 $aRet[] = "=?$default_charset?Q?$ret?=";
 786                 $iOffset = $i;
 787                 $cur_l = 0;
 788                 $ret = '';
 789                 $iEncStart = false;
 790             } else {
 791                 $ret .= sprintf("=%02X",ord($string{$i}));
 792             }
 793             break;
 794         case '(':
 795         case ')':
 796             if ($iEncStart !== false) {
 797                 $aRet[] = substr($string,$iOffset,$iEncStart-$iOffset);
 798                 $aRet[] = "=?$default_charset?Q?$ret?=";
 799                 $iOffset = $i;
 800                 $cur_l = 0;
 801                 $ret = '';
 802                 $iEncStart = false;
 803             }
 804             break;
 805         case ' ':
 806             if ($iEncStart !== false) {
 807                 $cur_l++;
 808                 if ($cur_l > $max_l) {
 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                 } else {
 816                     $ret .= '_';
 817                 }
 818             }
 819             break;
 820         default:
 821             $k = ord($string{$i});
 822             if ($k > 126) {
 823                 if ($iEncStart === false) {
 824                     // do not start encoding in the middle of a string, also take the rest of the word.
 825                     $sLeadString = substr($string,0,$i);
 826                     $aLeadString = explode(' ',$sLeadString);
 827                     $sToBeEncoded = array_pop($aLeadString);
 828                     $iEncStart = $i - strlen($sToBeEncoded);
 829                     $ret .= $sToBeEncoded;
 830                     $cur_l += strlen($sToBeEncoded);
 831                 }
 832                 $cur_l += 3;
 833                 /* first we add the encoded string that reached it's max size */
 834                 if ($cur_l > ($max_l-2)) {
 835                     $aRet[] = substr($string,$iOffset,$iEncStart-$iOffset);
 836                     $aRet[] = "=?$default_charset?Q?$ret?= "; /* the next part is also encoded => separate by space */
 837                     $cur_l = 3;
 838                     $ret = '';
 839                     $iOffset = $i;
 840                     $iEncStart = $i;
 841                 }
 842                 $enc_init = true;
 843                 $ret .= sprintf("=%02X", $k);
 844             } else {
 845                 if ($iEncStart !== false) {
 846                     $cur_l++;
 847                     if ($cur_l > $max_l) {
 848                         $aRet[] = substr($string,$iOffset,$iEncStart-$iOffset);
 849                         $aRet[] = "=?$default_charset?Q?$ret?=";
 850                         $iEncStart = false;
 851                         $iOffset = $i;
 852                         $cur_l = 0;
 853                         $ret = '';
 854                     } else {
 855                         $ret .= $string{$i};
 856                     }
 857                 }
 858             }
 859             break;
 860         }
 861     }
 862
 863     if ($enc_init) {
 864         if ($iEncStart !== false) {
 865             $aRet[] = substr($string,$iOffset,$iEncStart-$iOffset);
 866             $aRet[] = "=?$default_charset?Q?$ret?=";
 867         } else {
 868             $aRet[] = substr($string,$iOffset);
 869         }
 870         $string = implode('',$aRet);
 871     }
 872     return $string;
 873 }
 874
 875 /* This function trys to locate the entity_id of a specific mime element */
 876 function find_ent_id($id, $message) {
 877     for ($i = 0, $ret = ''; $ret == '' && $i < count($message->entities); $i++) {
 878         if ($message->entities[$i]->header->type0 == 'multipart')  {
 879             $ret = find_ent_id($id, $message->entities[$i]);
 880         } else {
 881             if (strcasecmp($message->entities[$i]->header->id, $id) == 0) {
 882 //                if (sq_check_save_extension($message->entities[$i])) {
 883                     return $message->entities[$i]->entity_id;
 884 //                }
 885             }
 886         }
 887     }
 888     return $ret;
 889 }
 890
 891 function sq_check_save_extension($message) {
 892     $filename = $message->getFilename();
 893     $ext = substr($filename, strrpos($filename,'.')+1);
 894     $save_extensions = array('jpg','jpeg','gif','png','bmp');
 895     return in_array($ext, $save_extensions);
 896 }
 897
 898
 899 /**
 900  ** HTMLFILTER ROUTINES
 901  */
 902
 903 /**
 904  * This function is more or less a wrapper around stripslashes. Apparently
 905  * Explorer is stupid enough to just remove the backslashes and then
 906  * execute the content of the attribute as if nothing happened.
 907  * Who does that?
 908  *
 909  * @param  attvalue   The value of the attribute
 910  * @return attvalue   The value of the attribute stripslashed.
 911  */
 912 function sq_unbackslash($attvalue){
 913     /**
 914      * Remove any backslashes. See if there are any first.
 915      */
 916
 917     if (strstr($attvalue, '\\') !== false){
 918         $attvalue = stripslashes($attvalue);
 919     }
 920     return $attvalue;
 921 }
 922
 923 /**
 924  * Kill any tabs, newlines, or carriage returns. Our friends the
 925  * makers of the browser with 95% market value decided that it'd
 926  * be funny to make "java[tab]script" be just as good as "javascript".
 927  *
 928  * @param  attvalue  The attribute value before extraneous spaces removed.
 929  * @return attvalue  The attribute value after extraneous spaces removed.
 930  */
 931 function sq_unspace($attvalue){
 932     if (strcspn($attvalue, "\t\r\n") != strlen($attvalue)){
 933         $attvalue = str_replace(Array("\t", "\r", "\n"), Array('', '', ''),
 934                                 $attvalue);
 935     }
 936     return $attvalue;
 937 }
 938
 939 /**
 940  * This function returns the final tag out of the tag name, an array
 941  * of attributes, and the type of the tag. This function is called by
 942  * sq_sanitize internally.
 943  *
 944  * @param  $tagname  the name of the tag.
 945  * @param  $attary   the array of attributes and their values
 946  * @param  $tagtype  The type of the tag (see in comments).
 947  * @return           a string with the final tag representation.
 948  */
 949 function sq_tagprint($tagname, $attary, $tagtype){
 950     $me = 'sq_tagprint';
 951
 952     if ($tagtype == 2){
 953         $fulltag = '</' . $tagname . '>';
 954     } else {
 955         $fulltag = '<' . $tagname;
 956         if (is_array($attary) && sizeof($attary)){
 957             $atts = Array();
 958             while (list($attname, $attvalue) = each($attary)){
 959                 array_push($atts, "$attname=$attvalue");
 960             }
 961             $fulltag .= ' ' . join(" ", $atts);
 962         }
 963         if ($tagtype == 3){
 964             $fulltag .= ' /';
 965         }
 966         $fulltag .= '>';
 967     }
 968     return $fulltag;
 969 }
 970
 971 /**
 972  * A small helper function to use with array_walk. Modifies a by-ref
 973  * value and makes it lowercase.
 974  *
 975  * @param  $val a value passed by-ref.
 976  * @return      void since it modifies a by-ref value.
 977  */
 978 function sq_casenormalize(&$val){
 979     $val = strtolower($val);
 980 }
 981
 982 /**
 983  * This function skips any whitespace from the current position within
 984  * a string and to the next non-whitespace value.
 985  *
 986  * @param  $body   the string
 987  * @param  $offset the offset within the string where we should start
 988  *                 looking for the next non-whitespace character.
 989  * @return         the location within the $body where the next
 990  *                 non-whitespace char is located.
 991  */
 992 function sq_skipspace($body, $offset){
 993     $me = 'sq_skipspace';
 994     preg_match('/^(\s*)/s', substr($body, $offset), $matches);
 995     if (sizeof($matches{1})){
 996         $count = strlen($matches{1});
 997         $offset += $count;
 998     }
 999     return $offset;
1000 }
1001
1002 /**
1003  * This function looks for the next character within a string.  It's
1004  * really just a glorified "strpos", except it catches if failures
1005  * nicely.
1006  *
1007  * @param  $body   The string to look for needle in.
1008  * @param  $offset Start looking from this position.
1009  * @param  $needle The character/string to look for.
1010  * @return         location of the next occurance of the needle, or
1011  *                 strlen($body) if needle wasn't found.
1012  */
1013 function sq_findnxstr($body, $offset, $needle){
1014     $me  = 'sq_findnxstr';
1015     $pos = strpos($body, $needle, $offset);
1016     if ($pos === FALSE){
1017         $pos = strlen($body);
1018     }
1019     return $pos;
1020 }
1021
1022 /**
1023  * This function takes a PCRE-style regexp and tries to match it
1024  * within the string.
1025  *
1026  * @param  $body   The string to look for needle in.
1027  * @param  $offset Start looking from here.
1028  * @param  $reg    A PCRE-style regex to match.
1029  * @return         Returns a false if no matches found, or an array
1030  *                 with the following members:
1031  *                 - integer with the location of the match within $body
1032  *                 - string with whatever content between offset and the match
1033  *                 - string with whatever it is we matched
1034  */
1035 function sq_findnxreg($body, $offset, $reg){
1036     $me = 'sq_findnxreg';
1037     $matches = Array();
1038     $retarr = Array();
1039     preg_match("%^(.*?)($reg)%si", substr($body, $offset), $matches);
1040     if (!isset($matches{0}) || !$matches{0}){
1041         $retarr = false;
1042     } else {
1043         $retarr{0} = $offset + strlen($matches{1});
1044         $retarr{1} = $matches{1};
1045         $retarr{2} = $matches{2};
1046     }
1047     return $retarr;
1048 }
1049
1050 /**
1051  * This function looks for the next tag.
1052  *
1053  * @param  $body   String where to look for the next tag.
1054  * @param  $offset Start looking from here.
1055  * @return         false if no more tags exist in the body, or
1056  *                 an array with the following members:
1057  *                 - string with the name of the tag
1058  *                 - array with attributes and their values
1059  *                 - integer with tag type (1, 2, or 3)
1060  *                 - integer where the tag starts (starting "<")
1061  *                 - integer where the tag ends (ending ">")
1062  *                 first three members will be false, if the tag is invalid.
1063  */
1064 function sq_getnxtag($body, $offset){
1065     $me = 'sq_getnxtag';
1066     if ($offset > strlen($body)){
1067         return false;
1068     }
1069     $lt = sq_findnxstr($body, $offset, "<");
1070     if ($lt == strlen($body)){
1071         return false;
1072     }
1073     /**
1074      * We are here:
1075      * blah blah <tag attribute="value">
1076      * \---------^
1077      */
1078     $pos = sq_skipspace($body, $lt+1);
1079     if ($pos >= strlen($body)){
1080         return Array(false, false, false, $lt, strlen($body));
1081     }
1082     /**
1083      * There are 3 kinds of tags:
1084      * 1. Opening tag, e.g.:
1085      *    <a href="blah">
1086      * 2. Closing tag, e.g.:
1087      *    </a>
1088      * 3. XHTML-style content-less tag, e.g.:
1089      *    <img src="blah" />
1090      */
1091     $tagtype = false;
1092     switch (substr($body, $pos, 1)){
1093         case '/':
1094             $tagtype = 2;
1095             $pos++;
1096             break;
1097         case '!':
1098             /**
1099              * A comment or an SGML declaration.
1100              */
1101             if (substr($body, $pos+1, 2) == "--"){
1102                 $gt = strpos($body, "-->", $pos);
1103                 if ($gt === false){
1104                     $gt = strlen($body);
1105                 } else {
1106                     $gt += 2;
1107                 }
1108                 return Array(false, false, false, $lt, $gt);
1109             } else {
1110                 $gt = sq_findnxstr($body, $pos, ">");
1111                 return Array(false, false, false, $lt, $gt);
1112             }
1113             break;
1114         default:
1115             /**
1116              * Assume tagtype 1 for now. If it's type 3, we'll switch values
1117              * later.
1118              */
1119             $tagtype = 1;
1120             break;
1121     }
1122
1123     $tag_start = $pos;
1124     $tagname = '';
1125     /**
1126      * Look for next [\W-_], which will indicate the end of the tag name.
1127      */
1128     $regary = sq_findnxreg($body, $pos, "[^\w\-_]");
1129     if ($regary == false){
1130         return Array(false, false, false, $lt, strlen($body));
1131     }
1132     list($pos, $tagname, $match) = $regary;
1133     $tagname = strtolower($tagname);
1134
1135     /**
1136      * $match can be either of these:
1137      * '>'  indicating the end of the tag entirely.
1138      * '\s' indicating the end of the tag name.
1139      * '/'  indicating that this is type-3 xhtml tag.
1140      *
1141      * Whatever else we find there indicates an invalid tag.
1142      */
1143     switch ($match){
1144         case '/':
1145             /**
1146              * This is an xhtml-style tag with a closing / at the
1147              * end, like so: <img src="blah" />. Check if it's followed
1148              * by the closing bracket. If not, then this tag is invalid
1149              */
1150             if (substr($body, $pos, 2) == "/>"){
1151                 $pos++;
1152                 $tagtype = 3;
1153             } else {
1154                 $gt = sq_findnxstr($body, $pos, ">");
1155                 $retary = Array(false, false, false, $lt, $gt);
1156                 return $retary;
1157             }
1158         case '>':
1159             return Array($tagname, false, $tagtype, $lt, $pos);
1160             break;
1161         default:
1162             /**
1163              * Check if it's whitespace
1164              */
1165             if (!preg_match('/\s/', $match)){
1166                 /**
1167                  * This is an invalid tag! Look for the next closing ">".
1168                  */
1169                 $gt = sq_findnxstr($body, $lt, ">");
1170                 return Array(false, false, false, $lt, $gt);
1171             }
1172             break;
1173     }
1174
1175     /**
1176      * At this point we're here:
1177      * <tagname  attribute='blah'>
1178      * \-------^
1179      *
1180      * At this point we loop in order to find all attributes.
1181      */
1182     $attname = '';
1183     $atttype = false;
1184     $attary = Array();
1185
1186     while ($pos <= strlen($body)){
1187         $pos = sq_skipspace($body, $pos);
1188         if ($pos == strlen($body)){
1189             /**
1190              * Non-closed tag.
1191              */
1192             return Array(false, false, false, $lt, $pos);
1193         }
1194         /**
1195          * See if we arrived at a ">" or "/>", which means that we reached
1196          * the end of the tag.
1197          */
1198         $matches = Array();
1199         if (preg_match("%^(\s*)(>|/>)%s", substr($body, $pos), $matches)) {
1200             /**
1201              * Yep. So we did.
1202              */
1203             $pos += strlen($matches{1});
1204             if ($matches{2} == "/>"){
1205                 $tagtype = 3;
1206                 $pos++;
1207             }
1208             return Array($tagname, $attary, $tagtype, $lt, $pos);
1209         }
1210
1211         /**
1212          * There are several types of attributes, with optional
1213          * [:space:] between members.
1214          * Type 1:
1215          *   attrname[:space:]=[:space:]'CDATA'
1216          * Type 2:
1217          *   attrname[:space:]=[:space:]"CDATA"
1218          * Type 3:
1219          *   attr[:space:]=[:space:]CDATA
1220          * Type 4:
1221          *   attrname
1222          *
1223          * We leave types 1 and 2 the same, type 3 we check for
1224          * '"' and convert to "&quot" if needed, then wrap in
1225          * double quotes. Type 4 we convert into:
1226          * attrname="yes".
1227          */
1228         $regary = sq_findnxreg($body, $pos, "[^:\w\-_]");
1229         if ($regary == false){
1230             /**
1231              * Looks like body ended before the end of tag.
1232              */
1233             return Array(false, false, false, $lt, strlen($body));
1234         }
1235         list($pos, $attname, $match) = $regary;
1236         $attname = strtolower($attname);
1237         /**
1238          * We arrived at the end of attribute name. Several things possible
1239          * here:
1240          * '>'  means the end of the tag and this is attribute type 4
1241          * '/'  if followed by '>' means the same thing as above
1242          * '\s' means a lot of things -- look what it's followed by.
1243          *      anything else means the attribute is invalid.
1244          */
1245         switch($match){
1246             case '/':
1247                 /**
1248                  * This is an xhtml-style tag with a closing / at the
1249                  * end, like so: <img src="blah" />. Check if it's followed
1250                  * by the closing bracket. If not, then this tag is invalid
1251                  */
1252                 if (substr($body, $pos, 2) == "/>"){
1253                     $pos++;
1254                     $tagtype = 3;
1255                 } else {
1256                     $gt = sq_findnxstr($body, $pos, ">");
1257                     $retary = Array(false, false, false, $lt, $gt);
1258                     return $retary;
1259                 }
1260             case '>':
1261                 $attary{$attname} = '"yes"';
1262                 return Array($tagname, $attary, $tagtype, $lt, $pos);
1263                 break;
1264             default:
1265                 /**
1266                  * Skip whitespace and see what we arrive at.
1267                  */
1268                 $pos = sq_skipspace($body, $pos);
1269                 $char = substr($body, $pos, 1);
1270                 /**
1271                  * Two things are valid here:
1272                  * '=' means this is attribute type 1 2 or 3.
1273                  * \w means this was attribute type 4.
1274                  * anything else we ignore and re-loop. End of tag and
1275                  * invalid stuff will be caught by our checks at the beginning
1276                  * of the loop.
1277                  */
1278                 if ($char == "="){
1279                     $pos++;
1280                     $pos = sq_skipspace($body, $pos);
1281                     /**
1282                      * Here are 3 possibilities:
1283                      * "'"  attribute type 1
1284                      * '"'  attribute type 2
1285                      * everything else is the content of tag type 3
1286                      */
1287                     $quot = substr($body, $pos, 1);
1288                     if ($quot == "'"){
1289                         $regary = sq_findnxreg($body, $pos+1, "\'");
1290                         if ($regary == false){
1291                             return Array(false, false, false, $lt, strlen($body));
1292                         }
1293                         list($pos, $attval, $match) = $regary;
1294                         $pos++;
1295                         $attary{$attname} = "'" . $attval . "'";
1296                     } else if ($quot == '"'){
1297                         $regary = sq_findnxreg($body, $pos+1, '\"');
1298                         if ($regary == false){
1299                             return Array(false, false, false, $lt, strlen($body));
1300                         }
1301                         list($pos, $attval, $match) = $regary;
1302                         $pos++;
1303                         $attary{$attname} = '"' . $attval . '"';
1304                     } else {
1305                         /**
1306                          * These are hateful. Look for \s, or >.
1307                          */
1308                         $regary = sq_findnxreg($body, $pos, "[\s>]");
1309                         if ($regary == false){
1310                             return Array(false, false, false, $lt, strlen($body));
1311                         }
1312                         list($pos, $attval, $match) = $regary;
1313                         /**
1314                          * If it's ">" it will be caught at the top.
1315                          */
1316                         $attval = preg_replace("/\"/s", "&quot;", $attval);
1317                         $attary{$attname} = '"' . $attval . '"';
1318                     }
1319                 } else if (preg_match("|[\w/>]|", $char)) {
1320                     /**
1321                      * That was attribute type 4.
1322                      */
1323                     $attary{$attname} = '"yes"';
1324                 } else {
1325                     /**
1326                      * An illegal character. Find next '>' and return.
1327                      */
1328                     $gt = sq_findnxstr($body, $pos, ">");
1329                     return Array(false, false, false, $lt, $gt);
1330                 }
1331                 break;
1332         }
1333     }
1334     /**
1335      * The fact that we got here indicates that the tag end was never
1336      * found. Return invalid tag indication so it gets stripped.
1337      */
1338     return Array(false, false, false, $lt, strlen($body));
1339 }
1340
1341 /**
1342  * This function checks attribute values for entity-encoded values
1343  * and returns them translated into 8-bit strings so we can run
1344  * checks on them.
1345  *
1346  * @param  $attvalue A string to run entity check against.
1347  * @return           Translated value.
1348  */
1349
1350 function sq_deent($attvalue){
1351     $me = 'sq_deent';
1352     /**
1353      * See if we have to run the checks first. All entities must start
1354      * with "&".
1355      */
1356     if (strpos($attvalue, '&') === false){
1357         return $attvalue;
1358     }
1359     /**
1360      * Check named entities first.
1361      */
1362     $trans = get_html_translation_table(HTML_ENTITIES);
1363     /**
1364      * Leave &quot; in, as it can mess us up.
1365      */
1366     $trans = array_flip($trans);
1367     unset($trans{'&quot;'});
1368     while (list($ent, $val) = each($trans)){
1369         $attvalue = preg_replace('/' . $ent . '*/si', $val, $attvalue);
1370     }
1371     /**
1372      * Now translate numbered entities from 1 to 255 if needed.
1373      */
1374     if (strpos($attvalue, '#') !== false){
1375         $omit = Array(34, 39);
1376         for ($asc = 256; $asc >= 0; $asc--){
1377             if (!in_array($asc, $omit)){
1378                 $chr = chr($asc);
1379                 $octrule = '/\&#0*' . $asc . ';*/si';
1380                 $hexrule = '/\&#x0*' . dechex($asc) . ';*/si';
1381                 $attvalue = preg_replace($octrule, $chr, $attvalue);
1382                 $attvalue = preg_replace($hexrule, $chr, $attvalue);
1383             }
1384         }
1385     }
1386     return $attvalue;
1387 }
1388
1389 /**
1390  * This function runs various checks against the attributes.
1391  *
1392  * @param  $tagname         String with the name of the tag.
1393  * @param  $attary          Array with all tag attributes.
1394  * @param  $rm_attnames     See description for sq_sanitize
1395  * @param  $bad_attvals     See description for sq_sanitize
1396  * @param  $add_attr_to_tag See description for sq_sanitize
1397  * @param  $message         message object
1398  * @param  $id              message id
1399  * @return                  Array with modified attributes.
1400  */
1401 function sq_fixatts($tagname,
1402                     $attary,
1403                     $rm_attnames,
1404                     $bad_attvals,
1405                     $add_attr_to_tag,
1406                     $message,
1407                     $id,
1408                     $mailbox
1409                     ){
1410     $me = 'sq_fixatts';
1411     while (list($attname, $attvalue) = each($attary)){
1412         /**
1413          * See if this attribute should be removed.
1414          */
1415         foreach ($rm_attnames as $matchtag=>$matchattrs){
1416             if (preg_match($matchtag, $tagname)){
1417                 foreach ($matchattrs as $matchattr){
1418                     if (preg_match($matchattr, $attname)){
1419                         unset($attary{$attname});
1420                         continue;
1421                     }
1422                 }
1423             }
1424         }
1425         /**
1426          * Remove any backslashes, entities, and extraneous whitespace.
1427          */
1428         $attvalue = sq_unbackslash($attvalue);
1429         $attvalue = sq_deent($attvalue);
1430         $attvalue = sq_unspace($attvalue);
1431
1432         /**
1433          * Remove \r \n \t \0 " " "\\"
1434          */
1435         $attvalue = str_replace(Array("\r", "\n", "\t", "\0", " ", "\\"),
1436                         Array('', '','','','',''), $attvalue);
1437
1438         /**
1439          * Now let's run checks on the attvalues.
1440          * I don't expect anyone to comprehend this. If you do,
1441          * get in touch with me so I can drive to where you live and
1442          * shake your hand personally. :)
1443          */
1444         foreach ($bad_attvals as $matchtag=>$matchattrs){
1445             if (preg_match($matchtag, $tagname)){
1446                 foreach ($matchattrs as $matchattr=>$valary){
1447                     if (preg_match($matchattr, $attname)){
1448                         /**
1449                          * There are two arrays in valary.
1450                          * First is matches.
1451                          * Second one is replacements
1452                          */
1453                         list($valmatch, $valrepl) = $valary;
1454                         $newvalue =
1455                             preg_replace($valmatch, $valrepl, $attvalue);
1456                         if ($newvalue != $attvalue){
1457                             $attary{$attname} = $newvalue;
1458                         }
1459                     }
1460                 }
1461             }
1462         }
1463         /**
1464          * Turn cid: urls into http-friendly ones.
1465          */
1466         if (preg_match("/^[\'\"]\s*cid:/si", $attvalue)){
1467             $attary{$attname} = sq_cid2http($message, $id, $attvalue, $mailbox);
1468         }
1469     }
1470     /**
1471      * See if we need to append any attributes to this tag.
1472      */
1473     foreach ($add_attr_to_tag as $matchtag=>$addattary){
1474         if (preg_match($matchtag, $tagname)){
1475             $attary = array_merge($attary, $addattary);
1476         }
1477     }
1478     return $attary;
1479 }
1480
1481 /**
1482  * This function edits the style definition to make them friendly and
1483  * usable in squirrelmail.
1484  *
1485  * @param  $message  the message object
1486  * @param  $id       the message id
1487  * @param  $content  a string with whatever is between <style> and </style>
1488  * @param  $mailbox  the message mailbox
1489  * @return           a string with edited content.
1490  */
1491 function sq_fixstyle($body, $pos, $message, $id, $mailbox){
1492     global $view_unsafe_images;
1493     $me = 'sq_fixstyle';
1494     $ret = sq_findnxreg($body, $pos, '</\s*style\s*>');
1495     if ($ret == FALSE){
1496         return array(FALSE, strlen($body));
1497     }
1498     $newpos = $ret[0] + strlen($ret[2]);
1499     $content = $ret[1];
1500     /**
1501      * First look for general BODY style declaration, which would be
1502      * like so:
1503      * body {background: blah-blah}
1504      * and change it to .bodyclass so we can just assign it to a <div>
1505      */
1506     $content = preg_replace("|body(\s*\{.*?\})|si", ".bodyclass\\1", $content);
1507     $secremoveimg = '../images/' . _("sec_remove_eng.png");
1508     /**
1509      * Fix url('blah') declarations.
1510      */
1511     $content = preg_replace("|url\s*\(\s*([\'\"])\s*\S+script\s*:.*?([\'\"])\s*\)|si",
1512                             "url(\\1$secremoveimg\\2)", $content);
1513     /**
1514      * Fix url('https*://.*) declarations but only if $view_unsafe_images
1515      * is false.
1516      */
1517     if (!$view_unsafe_images){
1518         $content = preg_replace("|url\s*\(\s*([\'\"])\s*https*:.*?([\'\"])\s*\)|si",
1519                                 "url(\\1$secremoveimg\\2)", $content);
1520     }
1521
1522     /**
1523      * Fix urls that refer to cid:
1524      */
1525     while (preg_match("|url\s*\(\s*([\'\"]\s*cid:.*?[\'\"])\s*\)|si",
1526                       $content, $matches)){
1527         $cidurl = $matches{1};
1528         $httpurl = sq_cid2http($message, $id, $cidurl, $mailbox);
1529         $content = preg_replace("|url\s*\(\s*$cidurl\s*\)|si",
1530                                 "url($httpurl)", $content);
1531     }
1532
1533     /**
1534      * Fix stupid css declarations which lead to vulnerabilities
1535      * in IE.
1536      */
1537     $match   = Array('/expression/i',
1538                      '/behaviou*r/i',
1539                      '/binding/i',
1540                      '/include-source/i');
1541     $replace = Array('idiocy', 'idiocy', 'idiocy', 'idiocy');
1542     $content = preg_replace($match, $replace, $content);
1543     return array($content, $newpos);
1544 }
1545
1546 /**
1547  * This function converts cid: url's into the ones that can be viewed in
1548  * the browser.
1549  *
1550  * @param  $message  the message object
1551  * @param  $id       the message id
1552  * @param  $cidurl   the cid: url.
1553  * @param  $mailbox  the message mailbox
1554  * @return           a string with a http-friendly url
1555  */
1556 function sq_cid2http($message, $id, $cidurl, $mailbox){
1557     /**
1558      * Get rid of quotes.
1559      */
1560     $quotchar = substr($cidurl, 0, 1);
1561     if ($quotchar == '"' || $quotchar == "'"){
1562         $cidurl = str_replace($quotchar, "", $cidurl);
1563     } else {
1564         $quotchar = '';
1565     }
1566     $cidurl = substr(trim($cidurl), 4);
1567     $linkurl = find_ent_id($cidurl, $message);
1568     /* in case of non-save cid links $httpurl should be replaced by a sort of
1569        unsave link image */
1570     $httpurl = '';
1571     if ($linkurl) {
1572         $httpurl = $quotchar . SM_PATH . 'src/download.php?absolute_dl=true&amp;' .
1573                    "passed_id=$id&amp;mailbox=" . urlencode($mailbox) .
1574                    '&amp;ent_id=' . $linkurl . $quotchar;
1575     }
1576     return $httpurl;
1577 }
1578
1579 /**
1580  * This function changes the <body> tag into a <div> tag since we
1581  * can't really have a body-within-body.
1582  *
1583  * @param  $attary   an array of attributes and values of <body>
1584  * @param  $mailbox  mailbox we're currently reading (for cid2http)
1585  * @param  $message  current message (for cid2http)
1586  * @param  $id       current message id (for cid2http)
1587  * @return           a modified array of attributes to be set for <div>
1588  */
1589 function sq_body2div($attary, $mailbox, $message, $id){
1590     $me = 'sq_body2div';
1591     $divattary = Array('class' => "'bodyclass'");
1592     $bgcolor = '#ffffff';
1593     $text = '#000000';
1594     $has_bgc_stl = $has_txt_stl = false;
1595     $styledef = '';
1596     if (is_array($attary) && sizeof($attary) > 0){
1597         foreach ($attary as $attname=>$attvalue){
1598             $quotchar = substr($attvalue, 0, 1);
1599             $attvalue = str_replace($quotchar, "", $attvalue);
1600             switch ($attname){
1601                 case 'background':
1602                     $attvalue = sq_cid2http($message, $id,
1603                                             $attvalue, $mailbox);
1604                     $styledef .= "background-image: url('$attvalue'); ";
1605                     break;
1606                 case 'bgcolor':
1607                     $has_bgc_stl = true;
1608                     $styledef .= "background-color: $attvalue; ";
1609                     break;
1610                 case 'text':
1611                     $has_txt_stl = true;
1612                     $styledef .= "color: $attvalue; ";
1613                     break;
1614             }
1615         }
1616         // Outlook defines a white bgcolor and no text color. This can lead to
1617         // white text on a white bg with certain themes.
1618         if ($has_bgc_stl && !$has_txt_stl) {
1619             $styledef .= "color: $text; ";
1620         }
1621         if (strlen($styledef) > 0){
1622             $divattary{"style"} = "\"$styledef\"";
1623         }
1624     }
1625     return $divattary;
1626 }
1627
1628 /**
1629  * This is the main function and the one you should actually be calling.
1630  * There are several variables you should be aware of an which need
1631  * special description.
1632  *
1633  * Since the description is quite lengthy, see it here:
1634  * http://linux.duke.edu/projects/mini/htmlfilter/
1635  *
1636  * @param $body                 the string with HTML you wish to filter
1637  * @param $tag_list             see description above
1638  * @param $rm_tags_with_content see description above
1639  * @param $self_closing_tags    see description above
1640  * @param $force_tag_closing    see description above
1641  * @param $rm_attnames          see description above
1642  * @param $bad_attvals          see description above
1643  * @param $add_attr_to_tag      see description above
1644  * @param $message              message object
1645  * @param $id                   message id
1646  * @return                      sanitized html safe to show on your pages.
1647  */
1648 function sq_sanitize($body,
1649                      $tag_list,
1650                      $rm_tags_with_content,
1651                      $self_closing_tags,
1652                      $force_tag_closing,
1653                      $rm_attnames,
1654                      $bad_attvals,
1655                      $add_attr_to_tag,
1656                      $message,
1657                      $id,
1658                      $mailbox
1659                      ){
1660     $me = 'sq_sanitize';
1661     $rm_tags = array_shift($tag_list);
1662     /**
1663      * Normalize rm_tags and rm_tags_with_content.
1664      */
1665     @array_walk($tag_list, 'sq_casenormalize');
1666     @array_walk($rm_tags_with_content, 'sq_casenormalize');
1667     @array_walk($self_closing_tags, 'sq_casenormalize');
1668     /**
1669      * See if tag_list is of tags to remove or tags to allow.
1670      * false  means remove these tags
1671      * true   means allow these tags
1672      */
1673     $curpos = 0;
1674     $open_tags = Array();
1675     $trusted = "\n<!-- begin sanitized html -->\n";
1676     $skip_content = false;
1677     /**
1678      * Take care of netscape's stupid javascript entities like
1679      * &{alert('boo')};
1680      */
1681     $body = preg_replace("/&(\{.*?\};)/si", "&amp;\\1", $body);
1682
1683     while (($curtag = sq_getnxtag($body, $curpos)) != FALSE){
1684         list($tagname, $attary, $tagtype, $lt, $gt) = $curtag;
1685         $free_content = substr($body, $curpos, $lt-$curpos);
1686         /**
1687          * Take care of <style>
1688          */
1689         if ($tagname == "style" && $tagtype == 1){
1690             list($free_content, $curpos) =
1691                 sq_fixstyle($body, $gt+1, $message, $id, $mailbox);
1692             if ($free_content != FALSE){
1693                 $trusted .= sq_tagprint($tagname, $attary, $tagtype);
1694                 $trusted .= $free_content;
1695                 $trusted .= sq_tagprint($tagname, false, 2);
1696             }
1697             continue;
1698         }
1699         if ($skip_content == false){
1700             $trusted .= $free_content;
1701         }
1702         if ($tagname != FALSE){
1703             if ($tagtype == 2){
1704                 if ($skip_content == $tagname){
1705                     /**
1706                      * Got to the end of tag we needed to remove.
1707                      */
1708                     $tagname = false;
1709                     $skip_content = false;
1710                 } else {
1711                     if ($skip_content == false){
1712                         if ($tagname == "body"){
1713                             $tagname = "div";
1714                         }
1715                         if (isset($open_tags{$tagname}) &&
1716                             $open_tags{$tagname} > 0){
1717                             $open_tags{$tagname}--;
1718                         } else {
1719                             $tagname = false;
1720                         }
1721                     }
1722                 }
1723             } else {
1724                 /**
1725                  * $rm_tags_with_content
1726                  */
1727                 if ($skip_content == false){
1728                     /**
1729                      * See if this is a self-closing type and change
1730                      * tagtype appropriately.
1731                      */
1732                     if ($tagtype == 1
1733                         && in_array($tagname, $self_closing_tags)){
1734                         $tagtype = 3;
1735                     }
1736                     /**
1737                      * See if we should skip this tag and any content
1738                      * inside it.
1739                      */
1740                     if ($tagtype == 1 &&
1741                         in_array($tagname, $rm_tags_with_content)){
1742                         $skip_content = $tagname;
1743                     } else {
1744                         if (($rm_tags == false
1745                              && in_array($tagname, $tag_list)) ||
1746                             ($rm_tags == true &&
1747                              !in_array($tagname, $tag_list))){
1748                             $tagname = false;
1749                         } else {
1750                             /**
1751                              * Convert body into div.
1752                              */
1753                             if ($tagname == "body"){
1754                                 $tagname = "div";
1755                                 $attary = sq_body2div($attary, $mailbox,
1756                                                       $message, $id);
1757                             }
1758                             if ($tagtype == 1){
1759                                 if (isset($open_tags{$tagname})){
1760                                     $open_tags{$tagname}++;
1761                                 } else {
1762                                     $open_tags{$tagname}=1;
1763                                 }
1764                             }
1765                             /**
1766                              * This is where we run other checks.
1767                              */
1768                             if (is_array($attary) && sizeof($attary) > 0){
1769                                 $attary = sq_fixatts($tagname,
1770                                                      $attary,
1771                                                      $rm_attnames,
1772                                                      $bad_attvals,
1773                                                      $add_attr_to_tag,
1774                                                      $message,
1775                                                      $id,
1776                                                      $mailbox
1777                                                      );
1778                             }
1779                         }
1780                     }
1781                 }
1782             }
1783             if ($tagname != false && $skip_content == false){
1784                 $trusted .= sq_tagprint($tagname, $attary, $tagtype);
1785             }
1786         }
1787         $curpos = $gt+1;
1788     }
1789     $trusted .= substr($body, $curpos, strlen($body)-$curpos);
1790     if ($force_tag_closing == true){
1791         foreach ($open_tags as $tagname=>$opentimes){
1792             while ($opentimes > 0){
1793                 $trusted .= '</' . $tagname . '>';
1794                 $opentimes--;
1795             }
1796         }
1797         $trusted .= "\n";
1798     }
1799     $trusted .= "<!-- end sanitized html -->\n";
1800     return $trusted;
1801 }
1802
1803 /**
1804  * This is a wrapper function to call html sanitizing routines.
1805  *
1806  * @param  $body  the body of the message
1807  * @param  $id    the id of the message
1808  * @return        a string with html safe to display in the browser.
1809  */
1810 function magicHTML($body, $id, $message, $mailbox = 'INBOX') {
1811     global $attachment_common_show_images, $view_unsafe_images,
1812            $has_unsafe_images;
1813     /**
1814      * Don't display attached images in HTML mode.
1815      */
1816     $attachment_common_show_images = false;
1817     $tag_list = Array(
1818                       false,
1819                       "object",
1820                       "meta",
1821                       "html",
1822                       "head",
1823                       "base",
1824                       "link",
1825                       "frame",
1826                       "iframe",
1827                       "plaintext",
1828                       "marquee"
1829                       );
1830
1831     $rm_tags_with_content = Array(
1832                                   "script",
1833                                   "applet",
1834                                   "embed",
1835                                   "title",
1836                                   "frameset",
1837                                   "xml"
1838                                   );
1839
1840     $self_closing_tags =  Array(
1841                                 "img",
1842                                 "br",
1843                                 "hr",
1844                                 "input"
1845                                 );
1846
1847     $force_tag_closing = true;
1848
1849     $rm_attnames = Array(
1850                          "/.*/" =>
1851                          Array(
1852                                "/target/i",
1853                                "/^on.*/i",
1854                                "/^dynsrc/i",
1855                                "/^data.*/i",
1856                                "/^lowsrc.*/i"
1857                                )
1858                          );
1859
1860     $secremoveimg = "../images/" . _("sec_remove_eng.png");
1861     $bad_attvals = Array(
1862         "/.*/" =>
1863             Array(
1864                 "/^src|background/i" =>
1865                     Array(
1866                           Array(
1867                                 "/^([\'\"])\s*\S+script\s*:.*([\'\"])/si",
1868                                 "/^([\'\"])\s*mocha\s*:*.*([\'\"])/si",
1869                                 "/^([\'\"])\s*about\s*:.*([\'\"])/si"
1870                                 ),
1871                           Array(
1872                                 "\\1$secremoveimg\\2",
1873                                 "\\1$secremoveimg\\2",
1874                                 "\\1$secremoveimg\\2",
1875                                 "\\1$secremoveimg\\2"
1876                                 )
1877                         ),
1878                 "/^href|action/i" =>
1879                     Array(
1880                           Array(
1881                                 "/^([\'\"])\s*\S+script\s*:.*([\'\"])/si",
1882                                 "/^([\'\"])\s*mocha\s*:*.*([\'\"])/si",
1883                                 "/^([\'\"])\s*about\s*:.*([\'\"])/si"
1884                                 ),
1885                           Array(
1886                                 "\\1#\\1",
1887                                 "\\1#\\1",
1888                                 "\\1#\\1",
1889                                 "\\1#\\1"
1890                                 )
1891                         ),
1892                 "/^style/i" =>
1893                     Array(
1894                           Array(
1895                                 "/expression/i",
1896                                 "/binding/i",
1897                                 "/behaviou*r/i",
1898                                 "/include-source/i",
1899                                 "/url\s*\(\s*([\'\"])\s*\S+script\s*:.*([\'\"])\s*\)/si",
1900                                 "/url\s*\(\s*([\'\"])\s*mocha\s*:.*([\'\"])\s*\)/si",
1901                                 "/url\s*\(\s*([\'\"])\s*about\s*:.*([\'\"])\s*\)/si",
1902                                 "/(.*)\s*:\s*url\s*\(\s*([\'\"]*)\s*\S+script\s*:.*([\'\"]*)\s*\)/si"
1903                                ),
1904                           Array(
1905                                 "idiocy",
1906                                 "idiocy",
1907                                 "idiocy",
1908                                 "idiocy",
1909                                 "url(\\1#\\1)",
1910                                 "url(\\1#\\1)",
1911                                 "url(\\1#\\1)",
1912                                 "url(\\1#\\1)",
1913                                 "\\1:url(\\2#\\3)"
1914                                )
1915                           )
1916                 )
1917         );
1918     if( !sqgetGlobalVar('view_unsafe_images', $view_unsafe_images, SQ_GET) ) {
1919         $view_unsafe_images = false;
1920     }
1921     if (!$view_unsafe_images){
1922         /**
1923          * Remove any references to http/https if view_unsafe_images set
1924          * to false.
1925          */
1926          array_push($bad_attvals{'/.*/'}{'/^src|background/i'}[0],
1927                     '/^([\'\"])\s*https*:.*([\'\"])/si');
1928          array_push($bad_attvals{'/.*/'}{'/^src|background/i'}[1],
1929                     "\\1$secremoveimg\\1");
1930          array_push($bad_attvals{'/.*/'}{'/^style/i'}[0],
1931                     '/url\(([\'\"])\s*https*:.*([\'\"])\)/si');
1932          array_push($bad_attvals{'/.*/'}{'/^style/i'}[1],
1933                     "url(\\1$secremoveimg\\1)");
1934     }
1935
1936     $add_attr_to_tag = Array(
1937         "/^a$/i" =>
1938             Array('target'=>'"_new"',
1939                   'title'=>'"'._("This external link will open in a new window").'"'
1940             )
1941     );
1942     $trusted = sq_sanitize($body,
1943                            $tag_list,
1944                            $rm_tags_with_content,
1945                            $self_closing_tags,
1946                            $force_tag_closing,
1947                            $rm_attnames,
1948                            $bad_attvals,
1949                            $add_attr_to_tag,
1950                            $message,
1951                            $id,
1952                            $mailbox
1953                            );
1954     if (preg_match("|$secremoveimg|i", $trusted)){
1955         $has_unsafe_images = true;
1956     }
1957     return $trusted;
1958 }
1959
1960 /**
1961  * function SendDownloadHeaders - send file to the browser
1962  *
1963  * Original Source: SM core src/download.php
1964  * moved here to make it available to other code, and separate
1965  * front end from back end functionality.
1966  *
1967  * @param string $type0 first half of mime type
1968  * @param string $type1 second half of mime type
1969  * @param string $filename filename to tell the browser for downloaded file
1970  * @param boolean $force whether to force the download dialog to pop
1971  * @param optional integer $filesize send the Content-Header and length to the browser
1972  * @return void
1973  */
1974  function SendDownloadHeaders($type0, $type1, $filename, $force, $filesize=0) {
1975      global $languages, $squirrelmail_language;
1976      $isIE = $isIE6 = 0;
1977
1978      sqgetGlobalVar('HTTP_USER_AGENT', $HTTP_USER_AGENT, SQ_SERVER);
1979
1980      if (strstr($HTTP_USER_AGENT, 'compatible; MSIE ') !== false &&
1981          strstr($HTTP_USER_AGENT, 'Opera') === false) {
1982          $isIE = 1;
1983      }
1984
1985      if (strstr($HTTP_USER_AGENT, 'compatible; MSIE 6') !== false &&
1986          strstr($HTTP_USER_AGENT, 'Opera') === false) {
1987          $isIE6 = 1;
1988      }
1989
1990      if (isset($languages[$squirrelmail_language]['XTRA_CODE']) &&
1991          function_exists($languages[$squirrelmail_language]['XTRA_CODE'] . '_downloadfilename')) {
1992          $filename =
1993          call_user_func($languages[$squirrelmail_language]['XTRA_CODE'] . '_downloadfilename', $filename, $HTTP_USER_AGENT);
1994      } else {
1995          $filename = ereg_replace('[\\/:\*\?"<>\|;]', '_', str_replace('&nbsp;', ' ', $filename));
1996      }
1997
1998      // A Pox on Microsoft and it's Internet Explorer!
1999      //
2000      // IE has lots of bugs with file downloads.
2001      // It also has problems with SSL.  Both of these cause problems
2002      // for us in this function.
2003      //
2004      // See this article on Cache Control headers and SSL
2005      // http://support.microsoft.com/default.aspx?scid=kb;en-us;323308
2006      //
2007      // The best thing you can do for IE is to upgrade to the latest
2008      // version
2009      //set all the Cache Control Headers for IE
2010      if ($isIE) {
2011          $filename=urlencode($filename);
2012          header ("Pragma: public");
2013          header ("Cache-Control: no-store, max-age=0, no-cache, must-revalidate"); # HTTP/1.1
2014          header ("Cache-Control: post-check=0, pre-check=0", false);
2015          header ("Cache-control: private");
2016
2017          //set the inline header for IE, we'll add the attachment header later if we need it
2018          header ("Content-Disposition: inline; filename=$filename");
2019      }
2020
2021      if (!$force) {
2022          // Try to show in browser window
2023          header ("Content-Disposition: inline; filename=\"$filename\"");
2024          header ("Content-Type: $type0/$type1; name=\"$filename\"");
2025      } else {
2026          // Try to pop up the "save as" box
2027
2028          // IE makes this hard.  It pops up 2 save boxes, or none.
2029          // http://support.microsoft.com/support/kb/articles/Q238/5/88.ASP
2030          // http://support.microsoft.com/default.aspx?scid=kb;EN-US;260519
2031          // But, according to Microsoft, it is "RFC compliant but doesn't
2032          // take into account some deviations that allowed within the
2033          // specification."  Doesn't that mean RFC non-compliant?
2034          // http://support.microsoft.com/support/kb/articles/Q258/4/52.ASP
2035
2036          // all browsers need the application/octet-stream header for this
2037          header ("Content-Type: application/octet-stream; name=\"$filename\"");
2038
2039          // http://support.microsoft.com/support/kb/articles/Q182/3/15.asp
2040          // Do not have quotes around filename, but that applied to
2041          // "attachment"... does it apply to inline too?
2042          header ("Content-Disposition: attachment; filename=\"$filename\"");
2043
2044          if ($isIE && !$isIE6) {
2045              // This combination seems to work mostly.  IE 5.5 SP 1 has
2046              // known issues (see the Microsoft Knowledge Base)
2047
2048              // This works for most types, but doesn't work with Word files
2049              header ("Content-Type: application/download; name=\"$filename\"");
2050
2051              // These are spares, just in case.  :-)
2052              //header("Content-Type: $type0/$type1; name=\"$filename\"");
2053              //header("Content-Type: application/x-msdownload; name=\"$filename\"");
2054              //header("Content-Type: application/octet-stream; name=\"$filename\"");
2055          } else {
2056              // another application/octet-stream forces download for Netscape
2057              header ("Content-Type: application/octet-stream; name=\"$filename\"");
2058          }
2059      }
2060
2061      //send the content-length header if the calling function provides it
2062      if ($filesize > 0) {
2063          header("Content-Length: $filesize");
2064      }
2065
2066 }  // end fn SendDownloadHeaders
2067
2068 ?>