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 ($utfencode) {
 681                     if ($can_be_encoded) {
 682                         /* convert string to different charset,
 683                          * if functions asks for it (usually in compose)
 684                          */
 685                         $ret .= charset_convert($res[2],$replace,$default_charset);
 686                     } else {
 687                         // convert string to html codes in order to display it
 688                         $ret .= charset_decode($res[2],$replace);
 689                     }
 690                 } else {
 691                     if ($htmlsave) {
 692                         $replace = htmlspecialchars($replace);
 693                     }
 694                     $ret.= $replace;
 695                 }
 696                 break;
 697             case 'Q':
 698                 $replace = str_replace('_', ' ', $res[4]);
 699                 $replace = preg_replace('/=([0-9a-f]{2})/ie', 'chr(hexdec("\1"))',
 700                                     $replace);
 701                 if ($utfencode) {
 702                   if ($can_be_encoded) {
 703                     /* convert string to different charset,
 704                      * if functions asks for it (usually in compose)
 705                      */
 706                     $replace = charset_convert($res[2], $replace,$default_charset);
 707                   } else {
 708                     // convert string to html codes in order to display it
 709                     $replace = charset_decode($res[2], $replace);
 710                   }
 711                 } else {
 712                     if ($htmlsave) {
 713                         $replace = htmlspecialchars($replace);
 714                     }
 715                 }
 716                 $ret .= $replace;
 717                 break;
 718             default:
 719                 break;
 720             }
 721             $chunk = $res[5];
 722             $encoded = true;
 723         }
 724         if (!$encoded) {
 725             if ($htmlsave) {
 726                 $ret .= '&#32;';
 727             } else {
 728                 $ret .= ' ';
 729             }
 730         }
 731
 732         if (!$encoded && $htmlsave) {
 733             $ret .= htmlspecialchars($chunk);
 734         } else {
 735             $ret .= $chunk;
 736         }
 737         ++$i;
 738     }
 739     /* remove the first added space */
 740     if ($ret) {
 741         if ($htmlsave) {
 742             $ret = substr($ret,5);
 743         } else {
 744             $ret = substr($ret,1);
 745         }
 746     }
 747
 748     return $ret;
 749 }
 750
 751 /**
 752  * Encodes header as quoted-printable
 753  *
 754  * Encode a string according to RFC 1522 for use in headers if it
 755  * contains 8-bit characters or anything that looks like it should
 756  * be encoded.
 757  *
 758  * @param string $string header string, that has to be encoded
 759  * @return string quoted-printable encoded string
 760  */
 761 function encodeHeader ($string) {
 762     global $default_charset, $languages, $squirrelmail_language;
 763
 764     if (isset($languages[$squirrelmail_language]['XTRA_CODE']) &&
 765         function_exists($languages[$squirrelmail_language]['XTRA_CODE'] . '_encodeheader')) {
 766         return  call_user_func($languages[$squirrelmail_language]['XTRA_CODE'] . '_encodeheader', $string);
 767     }
 768
 769     // Encode only if the string contains 8-bit characters or =?
 770     $j = strlen($string);
 771     $max_l = 75 - strlen($default_charset) - 7;
 772     $aRet = array();
 773     $ret = '';
 774     $iEncStart = $enc_init = false;
 775     $cur_l = $iOffset = 0;
 776     for($i = 0; $i < $j; ++$i) {
 777         switch($string{$i})
 778         {
 779         case '=':
 780         case '<':
 781         case '>':
 782         case ',':
 783         case '?':
 784         case '_':
 785             if ($iEncStart === false) {
 786                 $iEncStart = $i;
 787             }
 788             $cur_l+=3;
 789             if ($cur_l > ($max_l-2)) {
 790                 /* if there is an stringpart that doesn't need encoding, add it */
 791                 $aRet[] = substr($string,$iOffset,$iEncStart-$iOffset);
 792                 $aRet[] = "=?$default_charset?Q?$ret?=";
 793                 $iOffset = $i;
 794                 $cur_l = 0;
 795                 $ret = '';
 796                 $iEncStart = false;
 797             } else {
 798                 $ret .= sprintf("=%02X",ord($string{$i}));
 799             }
 800             break;
 801         case '(':
 802         case ')':
 803             if ($iEncStart !== false) {
 804                 $aRet[] = substr($string,$iOffset,$iEncStart-$iOffset);
 805                 $aRet[] = "=?$default_charset?Q?$ret?=";
 806                 $iOffset = $i;
 807                 $cur_l = 0;
 808                 $ret = '';
 809                 $iEncStart = false;
 810             }
 811             break;
 812         case ' ':
 813             if ($iEncStart !== false) {
 814                 $cur_l++;
 815                 if ($cur_l > $max_l) {
 816                     $aRet[] = substr($string,$iOffset,$iEncStart-$iOffset);
 817                     $aRet[] = "=?$default_charset?Q?$ret?=";
 818                     $iOffset = $i;
 819                     $cur_l = 0;
 820                     $ret = '';
 821                     $iEncStart = false;
 822                 } else {
 823                     $ret .= '_';
 824                 }
 825             }
 826             break;
 827         default:
 828             $k = ord($string{$i});
 829             if ($k > 126) {
 830                 if ($iEncStart === false) {
 831                     // do not start encoding in the middle of a string, also take the rest of the word.
 832                     $sLeadString = substr($string,0,$i);
 833                     $aLeadString = explode(' ',$sLeadString);
 834                     $sToBeEncoded = array_pop($aLeadString);
 835                     $iEncStart = $i - strlen($sToBeEncoded);
 836                     $ret .= $sToBeEncoded;
 837                     $cur_l += strlen($sToBeEncoded);
 838                 }
 839                 $cur_l += 3;
 840                 /* first we add the encoded string that reached it's max size */
 841                 if ($cur_l > ($max_l-2)) {
 842                     $aRet[] = substr($string,$iOffset,$iEncStart-$iOffset);
 843                     $aRet[] = "=?$default_charset?Q?$ret?= "; /* the next part is also encoded => separate by space */
 844                     $cur_l = 3;
 845                     $ret = '';
 846                     $iOffset = $i;
 847                     $iEncStart = $i;
 848                 }
 849                 $enc_init = true;
 850                 $ret .= sprintf("=%02X", $k);
 851             } else {
 852                 if ($iEncStart !== false) {
 853                     $cur_l++;
 854                     if ($cur_l > $max_l) {
 855                         $aRet[] = substr($string,$iOffset,$iEncStart-$iOffset);
 856                         $aRet[] = "=?$default_charset?Q?$ret?=";
 857                         $iEncStart = false;
 858                         $iOffset = $i;
 859                         $cur_l = 0;
 860                         $ret = '';
 861                     } else {
 862                         $ret .= $string{$i};
 863                     }
 864                 }
 865             }
 866             break;
 867         }
 868     }
 869
 870     if ($enc_init) {
 871         if ($iEncStart !== false) {
 872             $aRet[] = substr($string,$iOffset,$iEncStart-$iOffset);
 873             $aRet[] = "=?$default_charset?Q?$ret?=";
 874         } else {
 875             $aRet[] = substr($string,$iOffset);
 876         }
 877         $string = implode('',$aRet);
 878     }
 879     return $string;
 880 }
 881
 882 /* This function trys to locate the entity_id of a specific mime element */
 883 function find_ent_id($id, $message) {
 884     for ($i = 0, $ret = ''; $ret == '' && $i < count($message->entities); $i++) {
 885         if ($message->entities[$i]->header->type0 == 'multipart')  {
 886             $ret = find_ent_id($id, $message->entities[$i]);
 887         } else {
 888             if (strcasecmp($message->entities[$i]->header->id, $id) == 0) {
 889 //                if (sq_check_save_extension($message->entities[$i])) {
 890                     return $message->entities[$i]->entity_id;
 891 //                }
 892             }
 893         }
 894     }
 895     return $ret;
 896 }
 897
 898 function sq_check_save_extension($message) {
 899     $filename = $message->getFilename();
 900     $ext = substr($filename, strrpos($filename,'.')+1);
 901     $save_extensions = array('jpg','jpeg','gif','png','bmp');
 902     return in_array($ext, $save_extensions);
 903 }
 904
 905
 906 /**
 907  ** HTMLFILTER ROUTINES
 908  */
 909
 910 /**
 911  * This function is more or less a wrapper around stripslashes. Apparently
 912  * Explorer is stupid enough to just remove the backslashes and then
 913  * execute the content of the attribute as if nothing happened.
 914  * Who does that?
 915  *
 916  * @param  attvalue   The value of the attribute
 917  * @return attvalue   The value of the attribute stripslashed.
 918  */
 919 function sq_unbackslash($attvalue){
 920     /**
 921      * Remove any backslashes. See if there are any first.
 922      */
 923
 924     if (strstr($attvalue, '\\') !== false){
 925         $attvalue = stripslashes($attvalue);
 926     }
 927     return $attvalue;
 928 }
 929
 930 /**
 931  * Kill any tabs, newlines, or carriage returns. Our friends the
 932  * makers of the browser with 95% market value decided that it'd
 933  * be funny to make "java[tab]script" be just as good as "javascript".
 934  *
 935  * @param  attvalue  The attribute value before extraneous spaces removed.
 936  * @return attvalue  The attribute value after extraneous spaces removed.
 937  */
 938 function sq_unspace($attvalue){
 939     if (strcspn($attvalue, "\t\r\n") != strlen($attvalue)){
 940         $attvalue = str_replace(Array("\t", "\r", "\n"), Array('', '', ''),
 941                                 $attvalue);
 942     }
 943     return $attvalue;
 944 }
 945
 946 /**
 947  * This function returns the final tag out of the tag name, an array
 948  * of attributes, and the type of the tag. This function is called by
 949  * sq_sanitize internally.
 950  *
 951  * @param  $tagname  the name of the tag.
 952  * @param  $attary   the array of attributes and their values
 953  * @param  $tagtype  The type of the tag (see in comments).
 954  * @return           a string with the final tag representation.
 955  */
 956 function sq_tagprint($tagname, $attary, $tagtype){
 957     $me = 'sq_tagprint';
 958
 959     if ($tagtype == 2){
 960         $fulltag = '</' . $tagname . '>';
 961     } else {
 962         $fulltag = '<' . $tagname;
 963         if (is_array($attary) && sizeof($attary)){
 964             $atts = Array();
 965             while (list($attname, $attvalue) = each($attary)){
 966                 array_push($atts, "$attname=$attvalue");
 967             }
 968             $fulltag .= ' ' . join(" ", $atts);
 969         }
 970         if ($tagtype == 3){
 971             $fulltag .= ' /';
 972         }
 973         $fulltag .= '>';
 974     }
 975     return $fulltag;
 976 }
 977
 978 /**
 979  * A small helper function to use with array_walk. Modifies a by-ref
 980  * value and makes it lowercase.
 981  *
 982  * @param  $val a value passed by-ref.
 983  * @return      void since it modifies a by-ref value.
 984  */
 985 function sq_casenormalize(&$val){
 986     $val = strtolower($val);
 987 }
 988
 989 /**
 990  * This function skips any whitespace from the current position within
 991  * a string and to the next non-whitespace value.
 992  *
 993  * @param  $body   the string
 994  * @param  $offset the offset within the string where we should start
 995  *                 looking for the next non-whitespace character.
 996  * @return         the location within the $body where the next
 997  *                 non-whitespace char is located.
 998  */
 999 function sq_skipspace($body, $offset){
1000     $me = 'sq_skipspace';
1001     preg_match('/^(\s*)/s', substr($body, $offset), $matches);
1002     if (sizeof($matches{1})){
1003         $count = strlen($matches{1});
1004         $offset += $count;
1005     }
1006     return $offset;
1007 }
1008
1009 /**
1010  * This function looks for the next character within a string.  It's
1011  * really just a glorified "strpos", except it catches if failures
1012  * nicely.
1013  *
1014  * @param  $body   The string to look for needle in.
1015  * @param  $offset Start looking from this position.
1016  * @param  $needle The character/string to look for.
1017  * @return         location of the next occurance of the needle, or
1018  *                 strlen($body) if needle wasn't found.
1019  */
1020 function sq_findnxstr($body, $offset, $needle){
1021     $me  = 'sq_findnxstr';
1022     $pos = strpos($body, $needle, $offset);
1023     if ($pos === FALSE){
1024         $pos = strlen($body);
1025     }
1026     return $pos;
1027 }
1028
1029 /**
1030  * This function takes a PCRE-style regexp and tries to match it
1031  * within the string.
1032  *
1033  * @param  $body   The string to look for needle in.
1034  * @param  $offset Start looking from here.
1035  * @param  $reg    A PCRE-style regex to match.
1036  * @return         Returns a false if no matches found, or an array
1037  *                 with the following members:
1038  *                 - integer with the location of the match within $body
1039  *                 - string with whatever content between offset and the match
1040  *                 - string with whatever it is we matched
1041  */
1042 function sq_findnxreg($body, $offset, $reg){
1043     $me = 'sq_findnxreg';
1044     $matches = Array();
1045     $retarr = Array();
1046     preg_match("%^(.*?)($reg)%si", substr($body, $offset), $matches);
1047     if (!isset($matches{0}) || !$matches{0}){
1048         $retarr = false;
1049     } else {
1050         $retarr{0} = $offset + strlen($matches{1});
1051         $retarr{1} = $matches{1};
1052         $retarr{2} = $matches{2};
1053     }
1054     return $retarr;
1055 }
1056
1057 /**
1058  * This function looks for the next tag.
1059  *
1060  * @param  $body   String where to look for the next tag.
1061  * @param  $offset Start looking from here.
1062  * @return         false if no more tags exist in the body, or
1063  *                 an array with the following members:
1064  *                 - string with the name of the tag
1065  *                 - array with attributes and their values
1066  *                 - integer with tag type (1, 2, or 3)
1067  *                 - integer where the tag starts (starting "<")
1068  *                 - integer where the tag ends (ending ">")
1069  *                 first three members will be false, if the tag is invalid.
1070  */
1071 function sq_getnxtag($body, $offset){
1072     $me = 'sq_getnxtag';
1073     if ($offset > strlen($body)){
1074         return false;
1075     }
1076     $lt = sq_findnxstr($body, $offset, "<");
1077     if ($lt == strlen($body)){
1078         return false;
1079     }
1080     /**
1081      * We are here:
1082      * blah blah <tag attribute="value">
1083      * \---------^
1084      */
1085     $pos = sq_skipspace($body, $lt+1);
1086     if ($pos >= strlen($body)){
1087         return Array(false, false, false, $lt, strlen($body));
1088     }
1089     /**
1090      * There are 3 kinds of tags:
1091      * 1. Opening tag, e.g.:
1092      *    <a href="blah">
1093      * 2. Closing tag, e.g.:
1094      *    </a>
1095      * 3. XHTML-style content-less tag, e.g.:
1096      *    <img src="blah" />
1097      */
1098     $tagtype = false;
1099     switch (substr($body, $pos, 1)){
1100         case '/':
1101             $tagtype = 2;
1102             $pos++;
1103             break;
1104         case '!':
1105             /**
1106              * A comment or an SGML declaration.
1107              */
1108             if (substr($body, $pos+1, 2) == "--"){
1109                 $gt = strpos($body, "-->", $pos);
1110                 if ($gt === false){
1111                     $gt = strlen($body);
1112                 } else {
1113                     $gt += 2;
1114                 }
1115                 return Array(false, false, false, $lt, $gt);
1116             } else {
1117                 $gt = sq_findnxstr($body, $pos, ">");
1118                 return Array(false, false, false, $lt, $gt);
1119             }
1120             break;
1121         default:
1122             /**
1123              * Assume tagtype 1 for now. If it's type 3, we'll switch values
1124              * later.
1125              */
1126             $tagtype = 1;
1127             break;
1128     }
1129
1130     $tag_start = $pos;
1131     $tagname = '';
1132     /**
1133      * Look for next [\W-_], which will indicate the end of the tag name.
1134      */
1135     $regary = sq_findnxreg($body, $pos, "[^\w\-_]");
1136     if ($regary == false){
1137         return Array(false, false, false, $lt, strlen($body));
1138     }
1139     list($pos, $tagname, $match) = $regary;
1140     $tagname = strtolower($tagname);
1141
1142     /**
1143      * $match can be either of these:
1144      * '>'  indicating the end of the tag entirely.
1145      * '\s' indicating the end of the tag name.
1146      * '/'  indicating that this is type-3 xhtml tag.
1147      *
1148      * Whatever else we find there indicates an invalid tag.
1149      */
1150     switch ($match){
1151         case '/':
1152             /**
1153              * This is an xhtml-style tag with a closing / at the
1154              * end, like so: <img src="blah" />. Check if it's followed
1155              * by the closing bracket. If not, then this tag is invalid
1156              */
1157             if (substr($body, $pos, 2) == "/>"){
1158                 $pos++;
1159                 $tagtype = 3;
1160             } else {
1161                 $gt = sq_findnxstr($body, $pos, ">");
1162                 $retary = Array(false, false, false, $lt, $gt);
1163                 return $retary;
1164             }
1165         case '>':
1166             return Array($tagname, false, $tagtype, $lt, $pos);
1167             break;
1168         default:
1169             /**
1170              * Check if it's whitespace
1171              */
1172             if (!preg_match('/\s/', $match)){
1173                 /**
1174                  * This is an invalid tag! Look for the next closing ">".
1175                  */
1176                 $gt = sq_findnxstr($body, $lt, ">");
1177                 return Array(false, false, false, $lt, $gt);
1178             }
1179             break;
1180     }
1181
1182     /**
1183      * At this point we're here:
1184      * <tagname  attribute='blah'>
1185      * \-------^
1186      *
1187      * At this point we loop in order to find all attributes.
1188      */
1189     $attname = '';
1190     $atttype = false;
1191     $attary = Array();
1192
1193     while ($pos <= strlen($body)){
1194         $pos = sq_skipspace($body, $pos);
1195         if ($pos == strlen($body)){
1196             /**
1197              * Non-closed tag.
1198              */
1199             return Array(false, false, false, $lt, $pos);
1200         }
1201         /**
1202          * See if we arrived at a ">" or "/>", which means that we reached
1203          * the end of the tag.
1204          */
1205         $matches = Array();
1206         if (preg_match("%^(\s*)(>|/>)%s", substr($body, $pos), $matches)) {
1207             /**
1208              * Yep. So we did.
1209              */
1210             $pos += strlen($matches{1});
1211             if ($matches{2} == "/>"){
1212                 $tagtype = 3;
1213                 $pos++;
1214             }
1215             return Array($tagname, $attary, $tagtype, $lt, $pos);
1216         }
1217
1218         /**
1219          * There are several types of attributes, with optional
1220          * [:space:] between members.
1221          * Type 1:
1222          *   attrname[:space:]=[:space:]'CDATA'
1223          * Type 2:
1224          *   attrname[:space:]=[:space:]"CDATA"
1225          * Type 3:
1226          *   attr[:space:]=[:space:]CDATA
1227          * Type 4:
1228          *   attrname
1229          *
1230          * We leave types 1 and 2 the same, type 3 we check for
1231          * '"' and convert to "&quot" if needed, then wrap in
1232          * double quotes. Type 4 we convert into:
1233          * attrname="yes".
1234          */
1235         $regary = sq_findnxreg($body, $pos, "[^:\w\-_]");
1236         if ($regary == false){
1237             /**
1238              * Looks like body ended before the end of tag.
1239              */
1240             return Array(false, false, false, $lt, strlen($body));
1241         }
1242         list($pos, $attname, $match) = $regary;
1243         $attname = strtolower($attname);
1244         /**
1245          * We arrived at the end of attribute name. Several things possible
1246          * here:
1247          * '>'  means the end of the tag and this is attribute type 4
1248          * '/'  if followed by '>' means the same thing as above
1249          * '\s' means a lot of things -- look what it's followed by.
1250          *      anything else means the attribute is invalid.
1251          */
1252         switch($match){
1253             case '/':
1254                 /**
1255                  * This is an xhtml-style tag with a closing / at the
1256                  * end, like so: <img src="blah" />. Check if it's followed
1257                  * by the closing bracket. If not, then this tag is invalid
1258                  */
1259                 if (substr($body, $pos, 2) == "/>"){
1260                     $pos++;
1261                     $tagtype = 3;
1262                 } else {
1263                     $gt = sq_findnxstr($body, $pos, ">");
1264                     $retary = Array(false, false, false, $lt, $gt);
1265                     return $retary;
1266                 }
1267             case '>':
1268                 $attary{$attname} = '"yes"';
1269                 return Array($tagname, $attary, $tagtype, $lt, $pos);
1270                 break;
1271             default:
1272                 /**
1273                  * Skip whitespace and see what we arrive at.
1274                  */
1275                 $pos = sq_skipspace($body, $pos);
1276                 $char = substr($body, $pos, 1);
1277                 /**
1278                  * Two things are valid here:
1279                  * '=' means this is attribute type 1 2 or 3.
1280                  * \w means this was attribute type 4.
1281                  * anything else we ignore and re-loop. End of tag and
1282                  * invalid stuff will be caught by our checks at the beginning
1283                  * of the loop.
1284                  */
1285                 if ($char == "="){
1286                     $pos++;
1287                     $pos = sq_skipspace($body, $pos);
1288                     /**
1289                      * Here are 3 possibilities:
1290                      * "'"  attribute type 1
1291                      * '"'  attribute type 2
1292                      * everything else is the content of tag type 3
1293                      */
1294                     $quot = substr($body, $pos, 1);
1295                     if ($quot == "'"){
1296                         $regary = sq_findnxreg($body, $pos+1, "\'");
1297                         if ($regary == false){
1298                             return Array(false, false, false, $lt, strlen($body));
1299                         }
1300                         list($pos, $attval, $match) = $regary;
1301                         $pos++;
1302                         $attary{$attname} = "'" . $attval . "'";
1303                     } else if ($quot == '"'){
1304                         $regary = sq_findnxreg($body, $pos+1, '\"');
1305                         if ($regary == false){
1306                             return Array(false, false, false, $lt, strlen($body));
1307                         }
1308                         list($pos, $attval, $match) = $regary;
1309                         $pos++;
1310                         $attary{$attname} = '"' . $attval . '"';
1311                     } else {
1312                         /**
1313                          * These are hateful. Look for \s, or >.
1314                          */
1315                         $regary = sq_findnxreg($body, $pos, "[\s>]");
1316                         if ($regary == false){
1317                             return Array(false, false, false, $lt, strlen($body));
1318                         }
1319                         list($pos, $attval, $match) = $regary;
1320                         /**
1321                          * If it's ">" it will be caught at the top.
1322                          */
1323                         $attval = preg_replace("/\"/s", "&quot;", $attval);
1324                         $attary{$attname} = '"' . $attval . '"';
1325                     }
1326                 } else if (preg_match("|[\w/>]|", $char)) {
1327                     /**
1328                      * That was attribute type 4.
1329                      */
1330                     $attary{$attname} = '"yes"';
1331                 } else {
1332                     /**
1333                      * An illegal character. Find next '>' and return.
1334                      */
1335                     $gt = sq_findnxstr($body, $pos, ">");
1336                     return Array(false, false, false, $lt, $gt);
1337                 }
1338                 break;
1339         }
1340     }
1341     /**
1342      * The fact that we got here indicates that the tag end was never
1343      * found. Return invalid tag indication so it gets stripped.
1344      */
1345     return Array(false, false, false, $lt, strlen($body));
1346 }
1347
1348 /**
1349  * This function checks attribute values for entity-encoded values
1350  * and returns them translated into 8-bit strings so we can run
1351  * checks on them.
1352  *
1353  * @param  $attvalue A string to run entity check against.
1354  * @return           Translated value.
1355  */
1356
1357 function sq_deent($attvalue){
1358     $me = 'sq_deent';
1359     /**
1360      * See if we have to run the checks first. All entities must start
1361      * with "&".
1362      */
1363     if (strpos($attvalue, '&') === false){
1364         return $attvalue;
1365     }
1366     /**
1367      * Check named entities first.
1368      */
1369     $trans = get_html_translation_table(HTML_ENTITIES);
1370     /**
1371      * Leave &quot; in, as it can mess us up.
1372      */
1373     $trans = array_flip($trans);
1374     unset($trans{'&quot;'});
1375     while (list($ent, $val) = each($trans)){
1376         $attvalue = preg_replace('/' . $ent . '*/si', $val, $attvalue);
1377     }
1378     /**
1379      * Now translate numbered entities from 1 to 255 if needed.
1380      */
1381     if (strpos($attvalue, '#') !== false){
1382         $omit = Array(34, 39);
1383         for ($asc = 256; $asc >= 0; $asc--){
1384             if (!in_array($asc, $omit)){
1385                 $chr = chr($asc);
1386                 $octrule = '/\&#0*' . $asc . ';*/si';
1387                 $hexrule = '/\&#x0*' . dechex($asc) . ';*/si';
1388                 $attvalue = preg_replace($octrule, $chr, $attvalue);
1389                 $attvalue = preg_replace($hexrule, $chr, $attvalue);
1390             }
1391         }
1392     }
1393     return $attvalue;
1394 }
1395
1396 /**
1397  * This function runs various checks against the attributes.
1398  *
1399  * @param  $tagname         String with the name of the tag.
1400  * @param  $attary          Array with all tag attributes.
1401  * @param  $rm_attnames     See description for sq_sanitize
1402  * @param  $bad_attvals     See description for sq_sanitize
1403  * @param  $add_attr_to_tag See description for sq_sanitize
1404  * @param  $message         message object
1405  * @param  $id              message id
1406  * @return                  Array with modified attributes.
1407  */
1408 function sq_fixatts($tagname,
1409                     $attary,
1410                     $rm_attnames,
1411                     $bad_attvals,
1412                     $add_attr_to_tag,
1413                     $message,
1414                     $id,
1415                     $mailbox
1416                     ){
1417     $me = 'sq_fixatts';
1418     while (list($attname, $attvalue) = each($attary)){
1419         /**
1420          * See if this attribute should be removed.
1421          */
1422         foreach ($rm_attnames as $matchtag=>$matchattrs){
1423             if (preg_match($matchtag, $tagname)){
1424                 foreach ($matchattrs as $matchattr){
1425                     if (preg_match($matchattr, $attname)){
1426                         unset($attary{$attname});
1427                         continue;
1428                     }
1429                 }
1430             }
1431         }
1432         /**
1433          * Remove any backslashes, entities, and extraneous whitespace.
1434          */
1435         $attvalue = sq_unbackslash($attvalue);
1436         $attvalue = sq_deent($attvalue);
1437         $attvalue = sq_unspace($attvalue);
1438
1439         /**
1440          * Remove \r \n \t \0 " " "\\"
1441          */
1442         $attvalue = str_replace(Array("\r", "\n", "\t", "\0", " ", "\\"),
1443                         Array('', '','','','',''), $attvalue);
1444
1445         /**
1446          * Now let's run checks on the attvalues.
1447          * I don't expect anyone to comprehend this. If you do,
1448          * get in touch with me so I can drive to where you live and
1449          * shake your hand personally. :)
1450          */
1451         foreach ($bad_attvals as $matchtag=>$matchattrs){
1452             if (preg_match($matchtag, $tagname)){
1453                 foreach ($matchattrs as $matchattr=>$valary){
1454                     if (preg_match($matchattr, $attname)){
1455                         /**
1456                          * There are two arrays in valary.
1457                          * First is matches.
1458                          * Second one is replacements
1459                          */
1460                         list($valmatch, $valrepl) = $valary;
1461                         $newvalue =
1462                             preg_replace($valmatch, $valrepl, $attvalue);
1463                         if ($newvalue != $attvalue){
1464                             $attary{$attname} = $newvalue;
1465                         }
1466                     }
1467                 }
1468             }
1469         }
1470         /**
1471          * Turn cid: urls into http-friendly ones.
1472          */
1473         if (preg_match("/^[\'\"]\s*cid:/si", $attvalue)){
1474             $attary{$attname} = sq_cid2http($message, $id, $attvalue, $mailbox);
1475         }
1476     }
1477     /**
1478      * See if we need to append any attributes to this tag.
1479      */
1480     foreach ($add_attr_to_tag as $matchtag=>$addattary){
1481         if (preg_match($matchtag, $tagname)){
1482             $attary = array_merge($attary, $addattary);
1483         }
1484     }
1485     return $attary;
1486 }
1487
1488 /**
1489  * This function edits the style definition to make them friendly and
1490  * usable in squirrelmail.
1491  *
1492  * @param  $message  the message object
1493  * @param  $id       the message id
1494  * @param  $content  a string with whatever is between <style> and </style>
1495  * @param  $mailbox  the message mailbox
1496  * @return           a string with edited content.
1497  */
1498 function sq_fixstyle($body, $pos, $message, $id, $mailbox){
1499     global $view_unsafe_images;
1500     $me = 'sq_fixstyle';
1501     $ret = sq_findnxreg($body, $pos, '</\s*style\s*>');
1502     if ($ret == FALSE){
1503         return array(FALSE, strlen($body));
1504     }
1505     $newpos = $ret[0] + strlen($ret[2]);
1506     $content = $ret[1];
1507     /**
1508      * First look for general BODY style declaration, which would be
1509      * like so:
1510      * body {background: blah-blah}
1511      * and change it to .bodyclass so we can just assign it to a <div>
1512      */
1513     $content = preg_replace("|body(\s*\{.*?\})|si", ".bodyclass\\1", $content);
1514     $secremoveimg = '../images/' . _("sec_remove_eng.png");
1515     /**
1516      * Fix url('blah') declarations.
1517      */
1518     $content = preg_replace("|url\s*\(\s*([\'\"])\s*\S+script\s*:.*?([\'\"])\s*\)|si",
1519                             "url(\\1$secremoveimg\\2)", $content);
1520     /**
1521      * Fix url('https*://.*) declarations but only if $view_unsafe_images
1522      * is false.
1523      */
1524     if (!$view_unsafe_images){
1525         $content = preg_replace("|url\s*\(\s*([\'\"])\s*https*:.*?([\'\"])\s*\)|si",
1526                                 "url(\\1$secremoveimg\\2)", $content);
1527     }
1528
1529     /**
1530      * Fix urls that refer to cid:
1531      */
1532     while (preg_match("|url\s*\(\s*([\'\"]\s*cid:.*?[\'\"])\s*\)|si",
1533                       $content, $matches)){
1534         $cidurl = $matches{1};
1535         $httpurl = sq_cid2http($message, $id, $cidurl, $mailbox);
1536         $content = preg_replace("|url\s*\(\s*$cidurl\s*\)|si",
1537                                 "url($httpurl)", $content);
1538     }
1539
1540     /**
1541      * Fix stupid css declarations which lead to vulnerabilities
1542      * in IE.
1543      */
1544     $match   = Array('/expression/i',
1545                      '/behaviou*r/i',
1546                      '/binding/i',
1547                      '/include-source/i');
1548     $replace = Array('idiocy', 'idiocy', 'idiocy', 'idiocy');
1549     $content = preg_replace($match, $replace, $content);
1550     return array($content, $newpos);
1551 }
1552
1553 /**
1554  * This function converts cid: url's into the ones that can be viewed in
1555  * the browser.
1556  *
1557  * @param  $message  the message object
1558  * @param  $id       the message id
1559  * @param  $cidurl   the cid: url.
1560  * @param  $mailbox  the message mailbox
1561  * @return           a string with a http-friendly url
1562  */
1563 function sq_cid2http($message, $id, $cidurl, $mailbox){
1564     /**
1565      * Get rid of quotes.
1566      */
1567     $quotchar = substr($cidurl, 0, 1);
1568     if ($quotchar == '"' || $quotchar == "'"){
1569         $cidurl = str_replace($quotchar, "", $cidurl);
1570     } else {
1571         $quotchar = '';
1572     }
1573     $cidurl = substr(trim($cidurl), 4);
1574     $linkurl = find_ent_id($cidurl, $message);
1575     /* in case of non-save cid links $httpurl should be replaced by a sort of
1576        unsave link image */
1577     $httpurl = '';
1578     if ($linkurl) {
1579         $httpurl = $quotchar . SM_PATH . 'src/download.php?absolute_dl=true&amp;' .
1580                    "passed_id=$id&amp;mailbox=" . urlencode($mailbox) .
1581                    '&amp;ent_id=' . $linkurl . $quotchar;
1582     }
1583     return $httpurl;
1584 }
1585
1586 /**
1587  * This function changes the <body> tag into a <div> tag since we
1588  * can't really have a body-within-body.
1589  *
1590  * @param  $attary   an array of attributes and values of <body>
1591  * @param  $mailbox  mailbox we're currently reading (for cid2http)
1592  * @param  $message  current message (for cid2http)
1593  * @param  $id       current message id (for cid2http)
1594  * @return           a modified array of attributes to be set for <div>
1595  */
1596 function sq_body2div($attary, $mailbox, $message, $id){
1597     $me = 'sq_body2div';
1598     $divattary = Array('class' => "'bodyclass'");
1599     $bgcolor = '#ffffff';
1600     $text = '#000000';
1601     $has_bgc_stl = $has_txt_stl = false;
1602     $styledef = '';
1603     if (is_array($attary) && sizeof($attary) > 0){
1604         foreach ($attary as $attname=>$attvalue){
1605             $quotchar = substr($attvalue, 0, 1);
1606             $attvalue = str_replace($quotchar, "", $attvalue);
1607             switch ($attname){
1608                 case 'background':
1609                     $attvalue = sq_cid2http($message, $id,
1610                                             $attvalue, $mailbox);
1611                     $styledef .= "background-image: url('$attvalue'); ";
1612                     break;
1613                 case 'bgcolor':
1614                     $has_bgc_stl = true;
1615                     $styledef .= "background-color: $attvalue; ";
1616                     break;
1617                 case 'text':
1618                     $has_txt_stl = true;
1619                     $styledef .= "color: $attvalue; ";
1620                     break;
1621             }
1622         }
1623         // Outlook defines a white bgcolor and no text color. This can lead to
1624         // white text on a white bg with certain themes.
1625         if ($has_bgc_stl && !$has_txt_stl) {
1626             $styledef .= "color: $text; ";
1627         }
1628         if (strlen($styledef) > 0){
1629             $divattary{"style"} = "\"$styledef\"";
1630         }
1631     }
1632     return $divattary;
1633 }
1634
1635 /**
1636  * This is the main function and the one you should actually be calling.
1637  * There are several variables you should be aware of an which need
1638  * special description.
1639  *
1640  * Since the description is quite lengthy, see it here:
1641  * http://linux.duke.edu/projects/mini/htmlfilter/
1642  *
1643  * @param $body                 the string with HTML you wish to filter
1644  * @param $tag_list             see description above
1645  * @param $rm_tags_with_content see description above
1646  * @param $self_closing_tags    see description above
1647  * @param $force_tag_closing    see description above
1648  * @param $rm_attnames          see description above
1649  * @param $bad_attvals          see description above
1650  * @param $add_attr_to_tag      see description above
1651  * @param $message              message object
1652  * @param $id                   message id
1653  * @return                      sanitized html safe to show on your pages.
1654  */
1655 function sq_sanitize($body,
1656                      $tag_list,
1657                      $rm_tags_with_content,
1658                      $self_closing_tags,
1659                      $force_tag_closing,
1660                      $rm_attnames,
1661                      $bad_attvals,
1662                      $add_attr_to_tag,
1663                      $message,
1664                      $id,
1665                      $mailbox
1666                      ){
1667     $me = 'sq_sanitize';
1668     $rm_tags = array_shift($tag_list);
1669     /**
1670      * Normalize rm_tags and rm_tags_with_content.
1671      */
1672     @array_walk($tag_list, 'sq_casenormalize');
1673     @array_walk($rm_tags_with_content, 'sq_casenormalize');
1674     @array_walk($self_closing_tags, 'sq_casenormalize');
1675     /**
1676      * See if tag_list is of tags to remove or tags to allow.
1677      * false  means remove these tags
1678      * true   means allow these tags
1679      */
1680     $curpos = 0;
1681     $open_tags = Array();
1682     $trusted = "\n<!-- begin sanitized html -->\n";
1683     $skip_content = false;
1684     /**
1685      * Take care of netscape's stupid javascript entities like
1686      * &{alert('boo')};
1687      */
1688     $body = preg_replace("/&(\{.*?\};)/si", "&amp;\\1", $body);
1689
1690     while (($curtag = sq_getnxtag($body, $curpos)) != FALSE){
1691         list($tagname, $attary, $tagtype, $lt, $gt) = $curtag;
1692         $free_content = substr($body, $curpos, $lt-$curpos);
1693         /**
1694          * Take care of <style>
1695          */
1696         if ($tagname == "style" && $tagtype == 1){
1697             list($free_content, $curpos) =
1698                 sq_fixstyle($body, $gt+1, $message, $id, $mailbox);
1699             if ($free_content != FALSE){
1700                 $trusted .= sq_tagprint($tagname, $attary, $tagtype);
1701                 $trusted .= $free_content;
1702                 $trusted .= sq_tagprint($tagname, false, 2);
1703             }
1704             continue;
1705         }
1706         if ($skip_content == false){
1707             $trusted .= $free_content;
1708         }
1709         if ($tagname != FALSE){
1710             if ($tagtype == 2){
1711                 if ($skip_content == $tagname){
1712                     /**
1713                      * Got to the end of tag we needed to remove.
1714                      */
1715                     $tagname = false;
1716                     $skip_content = false;
1717                 } else {
1718                     if ($skip_content == false){
1719                         if ($tagname == "body"){
1720                             $tagname = "div";
1721                         }
1722                         if (isset($open_tags{$tagname}) &&
1723                             $open_tags{$tagname} > 0){
1724                             $open_tags{$tagname}--;
1725                         } else {
1726                             $tagname = false;
1727                         }
1728                     }
1729                 }
1730             } else {
1731                 /**
1732                  * $rm_tags_with_content
1733                  */
1734                 if ($skip_content == false){
1735                     /**
1736                      * See if this is a self-closing type and change
1737                      * tagtype appropriately.
1738                      */
1739                     if ($tagtype == 1
1740                         && in_array($tagname, $self_closing_tags)){
1741                         $tagtype = 3;
1742                     }
1743                     /**
1744                      * See if we should skip this tag and any content
1745                      * inside it.
1746                      */
1747                     if ($tagtype == 1 &&
1748                         in_array($tagname, $rm_tags_with_content)){
1749                         $skip_content = $tagname;
1750                     } else {
1751                         if (($rm_tags == false
1752                              && in_array($tagname, $tag_list)) ||
1753                             ($rm_tags == true &&
1754                              !in_array($tagname, $tag_list))){
1755                             $tagname = false;
1756                         } else {
1757                             /**
1758                              * Convert body into div.
1759                              */
1760                             if ($tagname == "body"){
1761                                 $tagname = "div";
1762                                 $attary = sq_body2div($attary, $mailbox,
1763                                                       $message, $id);
1764                             }
1765                             if ($tagtype == 1){
1766                                 if (isset($open_tags{$tagname})){
1767                                     $open_tags{$tagname}++;
1768                                 } else {
1769                                     $open_tags{$tagname}=1;
1770                                 }
1771                             }
1772                             /**
1773                              * This is where we run other checks.
1774                              */
1775                             if (is_array($attary) && sizeof($attary) > 0){
1776                                 $attary = sq_fixatts($tagname,
1777                                                      $attary,
1778                                                      $rm_attnames,
1779                                                      $bad_attvals,
1780                                                      $add_attr_to_tag,
1781                                                      $message,
1782                                                      $id,
1783                                                      $mailbox
1784                                                      );
1785                             }
1786                         }
1787                     }
1788                 }
1789             }
1790             if ($tagname != false && $skip_content == false){
1791                 $trusted .= sq_tagprint($tagname, $attary, $tagtype);
1792             }
1793         }
1794         $curpos = $gt+1;
1795     }
1796     $trusted .= substr($body, $curpos, strlen($body)-$curpos);
1797     if ($force_tag_closing == true){
1798         foreach ($open_tags as $tagname=>$opentimes){
1799             while ($opentimes > 0){
1800                 $trusted .= '</' . $tagname . '>';
1801                 $opentimes--;
1802             }
1803         }
1804         $trusted .= "\n";
1805     }
1806     $trusted .= "<!-- end sanitized html -->\n";
1807     return $trusted;
1808 }
1809
1810 /**
1811  * This is a wrapper function to call html sanitizing routines.
1812  *
1813  * @param  $body  the body of the message
1814  * @param  $id    the id of the message
1815  * @return        a string with html safe to display in the browser.
1816  */
1817 function magicHTML($body, $id, $message, $mailbox = 'INBOX') {
1818     global $attachment_common_show_images, $view_unsafe_images,
1819            $has_unsafe_images;
1820     /**
1821      * Don't display attached images in HTML mode.
1822      */
1823     $attachment_common_show_images = false;
1824     $tag_list = Array(
1825                       false,
1826                       "object",
1827                       "meta",
1828                       "html",
1829                       "head",
1830                       "base",
1831                       "link",
1832                       "frame",
1833                       "iframe",
1834                       "plaintext",
1835                       "marquee"
1836                       );
1837
1838     $rm_tags_with_content = Array(
1839                                   "script",
1840                                   "applet",
1841                                   "embed",
1842                                   "title",
1843                                   "frameset",
1844                                   "xml"
1845                                   );
1846
1847     $self_closing_tags =  Array(
1848                                 "img",
1849                                 "br",
1850                                 "hr",
1851                                 "input"
1852                                 );
1853
1854     $force_tag_closing = true;
1855
1856     $rm_attnames = Array(
1857                          "/.*/" =>
1858                          Array(
1859                                "/target/i",
1860                                "/^on.*/i",
1861                                "/^dynsrc/i",
1862                                "/^data.*/i",
1863                                "/^lowsrc.*/i"
1864                                )
1865                          );
1866
1867     $secremoveimg = "../images/" . _("sec_remove_eng.png");
1868     $bad_attvals = Array(
1869         "/.*/" =>
1870             Array(
1871                 "/^src|background/i" =>
1872                     Array(
1873                           Array(
1874                                 "/^([\'\"])\s*\S+script\s*:.*([\'\"])/si",
1875                                 "/^([\'\"])\s*mocha\s*:*.*([\'\"])/si",
1876                                 "/^([\'\"])\s*about\s*:.*([\'\"])/si"
1877                                 ),
1878                           Array(
1879                                 "\\1$secremoveimg\\2",
1880                                 "\\1$secremoveimg\\2",
1881                                 "\\1$secremoveimg\\2",
1882                                 "\\1$secremoveimg\\2"
1883                                 )
1884                         ),
1885                 "/^href|action/i" =>
1886                     Array(
1887                           Array(
1888                                 "/^([\'\"])\s*\S+script\s*:.*([\'\"])/si",
1889                                 "/^([\'\"])\s*mocha\s*:*.*([\'\"])/si",
1890                                 "/^([\'\"])\s*about\s*:.*([\'\"])/si"
1891                                 ),
1892                           Array(
1893                                 "\\1#\\1",
1894                                 "\\1#\\1",
1895                                 "\\1#\\1",
1896                                 "\\1#\\1"
1897                                 )
1898                         ),
1899                 "/^style/i" =>
1900                     Array(
1901                           Array(
1902                                 "/expression/i",
1903                                 "/binding/i",
1904                                 "/behaviou*r/i",
1905                                 "/include-source/i",
1906                                 "/url\s*\(\s*([\'\"])\s*\S+script\s*:.*([\'\"])\s*\)/si",
1907                                 "/url\s*\(\s*([\'\"])\s*mocha\s*:.*([\'\"])\s*\)/si",
1908                                 "/url\s*\(\s*([\'\"])\s*about\s*:.*([\'\"])\s*\)/si",
1909                                 "/(.*)\s*:\s*url\s*\(\s*([\'\"]*)\s*\S+script\s*:.*([\'\"]*)\s*\)/si"
1910                                ),
1911                           Array(
1912                                 "idiocy",
1913                                 "idiocy",
1914                                 "idiocy",
1915                                 "idiocy",
1916                                 "url(\\1#\\1)",
1917                                 "url(\\1#\\1)",
1918                                 "url(\\1#\\1)",
1919                                 "url(\\1#\\1)",
1920                                 "\\1:url(\\2#\\3)"
1921                                )
1922                           )
1923                 )
1924         );
1925     if( !sqgetGlobalVar('view_unsafe_images', $view_unsafe_images, SQ_GET) ) {
1926         $view_unsafe_images = false;
1927     }
1928     if (!$view_unsafe_images){
1929         /**
1930          * Remove any references to http/https if view_unsafe_images set
1931          * to false.
1932          */
1933          array_push($bad_attvals{'/.*/'}{'/^src|background/i'}[0],
1934                     '/^([\'\"])\s*https*:.*([\'\"])/si');
1935          array_push($bad_attvals{'/.*/'}{'/^src|background/i'}[1],
1936                     "\\1$secremoveimg\\1");
1937          array_push($bad_attvals{'/.*/'}{'/^style/i'}[0],
1938                     '/url\(([\'\"])\s*https*:.*([\'\"])\)/si');
1939          array_push($bad_attvals{'/.*/'}{'/^style/i'}[1],
1940                     "url(\\1$secremoveimg\\1)");
1941     }
1942
1943     $add_attr_to_tag = Array(
1944         "/^a$/i" =>
1945             Array('target'=>'"_new"',
1946                   'title'=>'"'._("This external link will open in a new window").'"'
1947             )
1948     );
1949     $trusted = sq_sanitize($body,
1950                            $tag_list,
1951                            $rm_tags_with_content,
1952                            $self_closing_tags,
1953                            $force_tag_closing,
1954                            $rm_attnames,
1955                            $bad_attvals,
1956                            $add_attr_to_tag,
1957                            $message,
1958                            $id,
1959                            $mailbox
1960                            );
1961     if (preg_match("|$secremoveimg|i", $trusted)){
1962         $has_unsafe_images = true;
1963     }
1964     return $trusted;
1965 }
1966
1967 /**
1968  * function SendDownloadHeaders - send file to the browser
1969  *
1970  * Original Source: SM core src/download.php
1971  * moved here to make it available to other code, and separate
1972  * front end from back end functionality.
1973  *
1974  * @param string $type0 first half of mime type
1975  * @param string $type1 second half of mime type
1976  * @param string $filename filename to tell the browser for downloaded file
1977  * @param boolean $force whether to force the download dialog to pop
1978  * @param optional integer $filesize send the Content-Header and length to the browser
1979  * @return void
1980  */
1981  function SendDownloadHeaders($type0, $type1, $filename, $force, $filesize=0) {
1982      global $languages, $squirrelmail_language;
1983      $isIE = $isIE6 = 0;
1984
1985      sqgetGlobalVar('HTTP_USER_AGENT', $HTTP_USER_AGENT, SQ_SERVER);
1986
1987      if (strstr($HTTP_USER_AGENT, 'compatible; MSIE ') !== false &&
1988          strstr($HTTP_USER_AGENT, 'Opera') === false) {
1989          $isIE = 1;
1990      }
1991
1992      if (strstr($HTTP_USER_AGENT, 'compatible; MSIE 6') !== false &&
1993          strstr($HTTP_USER_AGENT, 'Opera') === false) {
1994          $isIE6 = 1;
1995      }
1996
1997      if (isset($languages[$squirrelmail_language]['XTRA_CODE']) &&
1998          function_exists($languages[$squirrelmail_language]['XTRA_CODE'] . '_downloadfilename')) {
1999          $filename =
2000          call_user_func($languages[$squirrelmail_language]['XTRA_CODE'] . '_downloadfilename', $filename, $HTTP_USER_AGENT);
2001      } else {
2002          $filename = ereg_replace('[\\/:\*\?"<>\|;]', '_', str_replace('&nbsp;', ' ', $filename));
2003      }
2004
2005      // A Pox on Microsoft and it's Internet Explorer!
2006      //
2007      // IE has lots of bugs with file downloads.
2008      // It also has problems with SSL.  Both of these cause problems
2009      // for us in this function.
2010      //
2011      // See this article on Cache Control headers and SSL
2012      // http://support.microsoft.com/default.aspx?scid=kb;en-us;323308
2013      //
2014      // The best thing you can do for IE is to upgrade to the latest
2015      // version
2016      //set all the Cache Control Headers for IE
2017      if ($isIE) {
2018          $filename=urlencode($filename);
2019          header ("Pragma: public");
2020          header ("Cache-Control: no-store, max-age=0, no-cache, must-revalidate"); # HTTP/1.1
2021          header ("Cache-Control: post-check=0, pre-check=0", false);
2022          header ("Cache-control: private");
2023
2024          //set the inline header for IE, we'll add the attachment header later if we need it
2025          header ("Content-Disposition: inline; filename=$filename");
2026      }
2027
2028      if (!$force) {
2029          // Try to show in browser window
2030          header ("Content-Disposition: inline; filename=\"$filename\"");
2031          header ("Content-Type: $type0/$type1; name=\"$filename\"");
2032      } else {
2033          // Try to pop up the "save as" box
2034
2035          // IE makes this hard.  It pops up 2 save boxes, or none.
2036          // http://support.microsoft.com/support/kb/articles/Q238/5/88.ASP
2037          // http://support.microsoft.com/default.aspx?scid=kb;EN-US;260519
2038          // But, according to Microsoft, it is "RFC compliant but doesn't
2039          // take into account some deviations that allowed within the
2040          // specification."  Doesn't that mean RFC non-compliant?
2041          // http://support.microsoft.com/support/kb/articles/Q258/4/52.ASP
2042
2043          // all browsers need the application/octet-stream header for this
2044          header ("Content-Type: application/octet-stream; name=\"$filename\"");
2045
2046          // http://support.microsoft.com/support/kb/articles/Q182/3/15.asp
2047          // Do not have quotes around filename, but that applied to
2048          // "attachment"... does it apply to inline too?
2049          header ("Content-Disposition: attachment; filename=\"$filename\"");
2050
2051          if ($isIE && !$isIE6) {
2052              // This combination seems to work mostly.  IE 5.5 SP 1 has
2053              // known issues (see the Microsoft Knowledge Base)
2054
2055              // This works for most types, but doesn't work with Word files
2056              header ("Content-Type: application/download; name=\"$filename\"");
2057
2058              // These are spares, just in case.  :-)
2059              //header("Content-Type: $type0/$type1; name=\"$filename\"");
2060              //header("Content-Type: application/x-msdownload; name=\"$filename\"");
2061              //header("Content-Type: application/octet-stream; name=\"$filename\"");
2062          } else {
2063              // another application/octet-stream forces download for Netscape
2064              header ("Content-Type: application/octet-stream; name=\"$filename\"");
2065          }
2066      }
2067
2068      //send the content-length header if the calling function provides it
2069      if ($filesize > 0) {
2070          header("Content-Length: $filesize");
2071      }
2072
2073 }  // end fn SendDownloadHeaders
2074
2075 ?>