functions/mime.php

   1 <?php
   2
   3 /**
   4  * mime.php
   5  *
   6  * Copyright (c) 1999-2003 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  * $Id$
  13  */
  14
  15 require_once(SM_PATH . 'functions/imap.php');
  16 require_once(SM_PATH . 'functions/attachment_common.php');
  17
  18 /* -------------------------------------------------------------------------- */
  19 /* MIME DECODING                                                              */
  20 /* -------------------------------------------------------------------------- */
  21
  22 /* This function gets the structure of a message and stores it in the "message" class.
  23  * It will return this object for use with all relevant header information and
  24  * fully parsed into the standard "message" object format.
  25  */
  26
  27 function mime_structure ($bodystructure, $flags=array()) {
  28
  29     /* Isolate the body structure and remove beginning and end parenthesis. */
  30     $read = trim(substr ($bodystructure, strpos(strtolower($bodystructure), 'bodystructure') + 13));
  31     $read = trim(substr ($read, 0, -1));
  32     $i = 0;
  33     $msg = Message::parseStructure($read,$i);
  34     if (!is_object($msg)) {
  35         include_once(SM_PATH . 'functions/display_messages.php');
  36         global $color, $mailbox;
  37         /* removed urldecode because $_GET is auto urldecoded ??? */
  38         displayPageHeader( $color, $mailbox );
  39         $errormessage  = _("SquirrelMail could not decode the bodystructure of the message");
  40         $errormessage .= '<BR>'._("the provided bodystructure by your imap-server").':<BR><BR>';
  41         $errormessage .= '<pre>' . htmlspecialchars($read) . '</pre>';
  42         plain_error_message( $errormessage, $color );
  43         echo '</body></html>';
  44         exit;
  45     }
  46     if (count($flags)) {
  47         foreach ($flags as $flag) {
  48             $char = strtoupper($flag{1});
  49             switch ($char) {
  50                 case 'S':
  51                     if (strtolower($flag) == '\\seen') {
  52                         $msg->is_seen = true;
  53                     }
  54                     break;
  55                 case 'A':
  56                     if (strtolower($flag) == '\\answered') {
  57                         $msg->is_answered = true;
  58                     }
  59                     break;
  60                 case 'D':
  61                     if (strtolower($flag) == '\\deleted') {
  62                         $msg->is_deleted = true;
  63                     }
  64                     break;
  65                 case 'F':
  66                     if (strtolower($flag) == '\\flagged') {
  67                         $msg->is_flagged = true;
  68                     }
  69                     break;
  70                 case 'M':
  71                     if (strtolower($flag) == '$mdnsent') {
  72                         $msg->is_mdnsent = true;
  73                     }
  74                     break;
  75                 default:
  76                     break;
  77             }
  78         }
  79     }
  80     //    listEntities($msg);
  81     return $msg;
  82 }
  83
  84
  85
  86 /* This starts the parsing of a particular structure.  It is called recursively,
  87  * so it can be passed different structures.  It returns an object of type
  88  * $message.
  89  * First, it checks to see if it is a multipart message.  If it is, then it
  90  * handles that as it sees is necessary.  If it is just a regular entity,
  91  * then it parses it and adds the necessary header information (by calling out
  92  * to mime_get_elements()
  93  */
  94
  95 function mime_fetch_body($imap_stream, $id, $ent_id=1) {
  96     global $uid_support;
  97     /* Do a bit of error correction.  If we couldn't find the entity id, just guess
  98      * that it is the first one.  That is usually the case anyway.
  99      */
 100
 101     if (!$ent_id) {
 102         $cmd = "FETCH $id BODY[]";
 103     } else {
 104         $cmd = "FETCH $id BODY[$ent_id]";
 105     }
 106
 107     $data = sqimap_run_command ($imap_stream, $cmd, true, $response, $message, $uid_support);
 108     do {
 109         $topline = trim(array_shift($data));
 110     } while($topline && ($topline[0] == '*') && !preg_match('/\* [0-9]+ FETCH.*/i', $topline)) ;
 111
 112     $wholemessage = implode('', $data);
 113     if (ereg('\\{([^\\}]*)\\}', $topline, $regs)) {
 114         $ret = substr($wholemessage, 0, $regs[1]);
 115         /* There is some information in the content info header that could be important
 116          * in order to parse html messages. Let's get them here.
 117          */
 118 //        if ($ret{0} == '<') {
 119 //            $data = sqimap_run_command ($imap_stream, "FETCH $id BODY[$ent_id.MIME]", true, $response, $message, $uid_support);
 120 //        }
 121     } else if (ereg('"([^"]*)"', $topline, $regs)) {
 122         $ret = $regs[1];
 123     } else {
 124         global $where, $what, $mailbox, $passed_id, $startMessage;
 125         $par = 'mailbox=' . urlencode($mailbox) . '&amp;passed_id=' . $passed_id;
 126         if (isset($where) && isset($what)) {
 127             $par .= '&amp;where=' . urlencode($where) . '&amp;what=' . urlencode($what);
 128         } else {
 129             $par .= '&amp;startMessage=' . $startMessage . '&amp;show_more=0';
 130         }
 131         $par .= '&amp;response=' . urlencode($response) .
 132                 '&amp;message='  . urlencode($message)  .
 133                 '&amp;topline='  . urlencode($topline);
 134
 135         echo   '<tt><br>' .
 136                '<table width="80%"><tr>' .
 137                '<tr><td colspan=2>' .
 138                _("Body retrieval error. The reason for this is most probably that the message is malformed.") .
 139                '</td></tr>' .
 140                '<tr><td><b>' . _("Command:") . "</td><td>$cmd</td></tr>" .
 141                '<tr><td><b>' . _("Response:") . "</td><td>$response</td></tr>" .
 142                '<tr><td><b>' . _("Message:") . "</td><td>$message</td></tr>" .
 143                '<tr><td><b>' . _("FETCH line:") . "</td><td>$topline</td></tr>" .
 144                "</table><BR></tt></font><hr>";
 145
 146         $data = sqimap_run_command ($imap_stream, "FETCH $passed_id BODY[]", true, $response, $message, $uid_support);
 147         array_shift($data);
 148         $wholemessage = implode('', $data);
 149
 150         $ret = $wholemessage;
 151     }
 152     return $ret;
 153 }
 154
 155 function mime_print_body_lines ($imap_stream, $id, $ent_id=1, $encoding) {
 156     global $uid_support;
 157
 158     /* Don't kill the connection if the browser is over a dialup
 159      * and it would take over 30 seconds to download it.
 160      * Don´t call set_time_limit in safe mode.
 161      */
 162
 163     if (!ini_get('safe_mode')) {
 164         set_time_limit(0);
 165     }
 166     /* in case of base64 encoded attachments, do not buffer them.
 167        Instead, echo the decoded attachment directly to screen */
 168     if (strtolower($encoding) == 'base64') {
 169         if (!$ent_id) {
 170            $query = "FETCH $id BODY[]";
 171         } else {
 172            $query = "FETCH $id BODY[$ent_id]";
 173         }
 174         sqimap_run_command($imap_stream,$query,true,$response,$message,$uid_support,'sqimap_base64_decode','php://stdout',true);
 175     } else {
 176        $body = mime_fetch_body ($imap_stream, $id, $ent_id);
 177        echo decodeBody($body, $encoding);
 178     }
 179
 180     /*
 181        TODO, use the same method for quoted printable.
 182        However, I assume that quoted printable attachments aren't that large
 183        so the performancegain / memory usage drop will be minimal.
 184        If we decide to add that then we need to adapt sqimap_fread because
 185        we need to split te result on \n and fread doesn't stop at \n. That
 186        means we also should provide $results from sqimap_fread (by ref) to
 187        te function and set $no_return to false. The $filter function for
 188        quoted printable should handle unsetting of $results.
 189     */
 190     /*
 191        TODO 2: find out how we write to the output stream php://stdout. fwrite
 192        doesn't work because 'php://stdout isn't a stream.
 193     */
 194
 195     return;
 196 /*
 197     fputs ($imap_stream, "$sid FETCH $id BODY[$ent_id]\r\n");
 198     $cnt = 0;
 199     $continue = true;
 200     $read = fgets ($imap_stream,8192);
 201
 202
 203     // This could be bad -- if the section has sqimap_session_id() . ' OK'
 204     // or similar, it will kill the download.
 205     while (!ereg("^".$sid_s." (OK|BAD|NO)(.*)$", $read, $regs)) {
 206         if (trim($read) == ')==') {
 207             $read1 = $read;
 208             $read = fgets ($imap_stream,4096);
 209             if (ereg("^".$sid." (OK|BAD|NO)(.*)$", $read, $regs)) {
 210                 return;
 211             } else {
 212                 echo decodeBody($read1, $encoding) .
 213                      decodeBody($read, $encoding);
 214             }
 215         } else if ($cnt) {
 216             echo decodeBody($read, $encoding);
 217         }
 218         $read = fgets ($imap_stream,4096);
 219         $cnt++;
 220 //      break;
 221     }
 222 */
 223 }
 224
 225 /* -[ END MIME DECODING ]----------------------------------------------------------- */
 226
 227 /* This is here for debugging purposes.  It will print out a list
 228  * of all the entity IDs that are in the $message object.
 229  */
 230 function listEntities ($message) {
 231     if ($message) {
 232         echo "<tt>" . $message->entity_id . ' : ' . $message->type0 . '/' . $message->type1 . ' parent = '. $message->parent->entity_id. '<br>';
 233         for ($i = 0; isset($message->entities[$i]); $i++) {
 234             echo "$i : ";
 235             $msg = listEntities($message->entities[$i]);
 236
 237             if ($msg) {
 238                 echo "return: ";
 239                 return $msg;
 240             }
 241         }
 242     }
 243 }
 244
 245 function getPriorityStr($priority) {
 246     $priority_level = substr($priority,0,1);
 247
 248     switch($priority_level) {
 249         /* Check for a higher then normal priority. */
 250         case '1':
 251         case '2':
 252             $priority_string = _("High");
 253             break;
 254
 255         /* Check for a lower then normal priority. */
 256         case '4':
 257         case '5':
 258             $priority_string = _("Low");
 259             break;
 260
 261         /* Check for a normal priority. */
 262         case '3':
 263         default:
 264             $priority_level = '3';
 265             $priority_string = _("Normal");
 266             break;
 267
 268     }
 269     return $priority_string;
 270 }
 271
 272 /* returns a $message object for a particular entity id */
 273 function getEntity ($message, $ent_id) {
 274     return $message->getEntity($ent_id);
 275 }
 276
 277 /* translateText
 278  * Extracted from strings.php 23/03/2002
 279  */
 280
 281 function translateText(&$body, $wrap_at, $charset) {
 282     global $where, $what;   /* from searching */
 283     global $color;          /* color theme */
 284
 285     require_once(SM_PATH . 'functions/url_parser.php');
 286
 287     $body_ary = explode("\n", $body);
 288     for ($i=0; $i < count($body_ary); $i++) {
 289         $line = $body_ary[$i];
 290         if (strlen($line) - 2 >= $wrap_at) {
 291             sqWordWrap($line, $wrap_at);
 292         }
 293         $line = charset_decode($charset, $line);
 294         $line = str_replace("\t", '        ', $line);
 295
 296         parseUrl ($line);
 297
 298         $quotes = 0;
 299         $pos = 0;
 300         $j = strlen($line);
 301
 302         while ($pos < $j) {
 303             if ($line[$pos] == ' ') {
 304                 $pos++;
 305             } else if (strpos($line, '&gt;', $pos) === $pos) {
 306                 $pos += 4;
 307                 $quotes++;
 308             } else {
 309                 break;
 310             }
 311         }
 312
 313         if ($quotes % 2) {
 314             if (!isset($color[13])) {
 315                 $color[13] = '#800000';
 316             }
 317             $line = '<font color="' . $color[13] . '">' . $line . '</font>';
 318         } elseif ($quotes) {
 319             if (!isset($color[14])) {
 320                 $color[14] = '#FF0000';
 321             }
 322             $line = '<font color="' . $color[14] . '">' . $line . '</font>';
 323         }
 324
 325         $body_ary[$i] = $line;
 326     }
 327     $body = '<pre>' . implode("\n", $body_ary) . '</pre>';
 328 }
 329
 330 /* This returns a parsed string called $body. That string can then
 331  * be displayed as the actual message in the HTML. It contains
 332  * everything needed, including HTML Tags, Attachments at the
 333  * bottom, etc.
 334  */
 335 function formatBody($imap_stream, $message, $color, $wrap_at, $ent_num, $id, $mailbox='INBOX') {
 336     /* This if statement checks for the entity to show as the
 337      * primary message. To add more of them, just put them in the
 338      * order that is their priority.
 339      */
 340     global $startMessage, $username, $key, $imapServerAddress, $imapPort,
 341            $show_html_default, $sort, $has_unsafe_images, $passed_ent_id;
 342     global $languages, $squirrelmail_language;
 343
 344     if( !sqgetGlobalVar('view_unsafe_images', $view_unsafe_images, SQ_GET) ) {
 345         $view_unsafe_images = false;
 346     }
 347
 348     $body = '';
 349     $urlmailbox = urlencode($mailbox);
 350     $body_message = getEntity($message, $ent_num);
 351     if (($body_message->header->type0 == 'text') ||
 352         ($body_message->header->type0 == 'rfc822')) {
 353         $body = mime_fetch_body ($imap_stream, $id, $ent_num);
 354         $body = decodeBody($body, $body_message->header->encoding);
 355
 356         if (isset($languages[$squirrelmail_language]['XTRA_CODE']) &&
 357             function_exists($languages[$squirrelmail_language]['XTRA_CODE'])) {
 358             if (mb_detect_encoding($body) != 'ASCII') {
 359                 $body = $languages[$squirrelmail_language]['XTRA_CODE']('decode', $body);
 360             }
 361         }
 362         $hookResults = do_hook("message_body", $body);
 363         $body = $hookResults[1];
 364
 365         /* If there are other types that shouldn't be formatted, add
 366          * them here.
 367          */
 368
 369         if ($body_message->header->type1 == 'html') {
 370             if ($show_html_default <> 1) {
 371                 $entity_conv = array('&nbsp;' => ' ',
 372                                      '<p>'    => "\n",
 373                                      '<br>'   => "\n",
 374                                      '<P>'    => "\n",
 375                                      '<BR>'   => "\n",
 376                                      '&gt;'   => '>',
 377                                      '&lt;'   => '<');
 378                 $body = strtr($body, $entity_conv);
 379                 $body = strip_tags($body);
 380                 $body = trim($body);
 381                 translateText($body, $wrap_at,
 382                               $body_message->header->getParameter('charset'));
 383             } else {
 384                 $body = magicHTML($body, $id, $message, $mailbox);
 385             }
 386         } else {
 387             translateText($body, $wrap_at,
 388                           $body_message->header->getParameter('charset'));
 389         }
 390         $link = 'read_body.php?passed_id=' . $id . '&amp;ent_id='.$ent_num.
 391                 '&amp;mailbox=' . $urlmailbox .'&amp;sort=' . $sort .
 392                 '&amp;startMessage=' . $startMessage . '&amp;show_more=0';
 393         if (isset($passed_ent_id)) {
 394             $link .= '&amp;passed_ent_id='.$passed_ent_id;
 395         }
 396         if ($view_unsafe_images) {
 397             $text = _("Hide Unsafe Images");
 398         } else {
 399             if (isset($has_unsafe_images) && $has_unsafe_images) {
 400                 $link .= '&amp;view_unsafe_images=1';
 401                 $text = _("View Unsafe Images");
 402             } else {
 403                 $text = '';
 404             }
 405         }
 406         $body .= '<center><small><a href="'.$link.'">'.$text.
 407                  '</a></small></center><br>' . "\n";
 408     }
 409     return $body;
 410 }
 411
 412
 413 function formatAttachments($message, $exclude_id, $mailbox, $id) {
 414     global $where, $what, $startMessage, $color;
 415     static $ShownHTML = 0;
 416
 417     $att_ar = $message->getAttachments($exclude_id);
 418
 419     if (!count($att_ar)) return '';
 420
 421     $attachments = '';
 422
 423     $urlMailbox = urlencode($mailbox);
 424
 425     foreach ($att_ar as $att) {
 426         $ent = $att->entity_id;
 427         $header = $att->header;
 428         $type0 = strtolower($header->type0);
 429         $type1 = strtolower($header->type1);
 430         $name = '';
 431         $links['download link']['text'] = _("download");
 432         $links['download link']['href'] = SM_PATH .
 433                 "src/download.php?absolute_dl=true&amp;passed_id=$id&amp;mailbox=$urlMailbox&amp;ent_id=$ent";
 434         $ImageURL = '';
 435         if ($type0 =='message' && $type1 == 'rfc822') {
 436             $default_page = SM_PATH . 'src/read_body.php';
 437             $rfc822_header = $att->rfc822_header;
 438             $filename = $rfc822_header->subject;
 439             if (trim( $filename ) == '') {
 440                 $filename = 'untitled-[' . $ent . ']' ;
 441             }
 442             $from_o = $rfc822_header->from;
 443             if (is_object($from_o)) {
 444                 $from_name = decodeHeader($from_o->getAddress(false));
 445             } else {
 446                 $from_name = _("Unknown sender");
 447             }
 448             $description = $from_name;
 449         } else {
 450             $default_page = SM_PATH . 'src/download.php';
 451             if (is_object($header->disposition)) {
 452                 $filename = $header->disposition->getProperty('filename');
 453                 if (trim($filename) == '') {
 454                     $name = decodeHeader($header->disposition->getProperty('name'));
 455                     if (trim($name) == '') {
 456                         $name = $header->getParameter('name');
 457                         if(trim($name) == '') {
 458                             if (trim( $header->id ) == '') {
 459                                 $filename = 'untitled-[' . $ent . ']' ;
 460                             } else {
 461                                 $filename = 'cid: ' . $header->id;
 462                             }
 463                         } else {
 464                             $filename = $name;
 465                         }
 466                     } else {
 467                         $filename = $name;
 468                     }
 469                 }
 470             } else {
 471                 $filename = $header->getParameter('name');
 472                 if (!trim($filename)) {
 473                     if (trim( $header->id ) == '') {
 474                         $filename = 'untitled-[' . $ent . ']' ;
 475                     } else {
 476                         $filename = 'cid: ' . $header->id;
 477                     }
 478                 }
 479             }
 480             if ($header->description) {
 481                 $description = decodeHeader($header->description);
 482             } else {
 483                 $description = '';
 484             }
 485         }
 486
 487         $display_filename = $filename;
 488         if (isset($passed_ent_id)) {
 489             $passed_ent_id_link = '&amp;passed_ent_id='.$passed_ent_id;
 490         } else {
 491             $passed_ent_id_link = '';
 492         }
 493         $defaultlink = $default_page . "?startMessage=$startMessage"
 494                      . "&amp;passed_id=$id&amp;mailbox=$urlMailbox"
 495                      . '&amp;ent_id='.$ent.$passed_ent_id_link;
 496         if ($where && $what) {
 497            $defaultlink .= '&amp;where='. urlencode($where).'&amp;what='.urlencode($what);
 498         }
 499         /* This executes the attachment hook with a specific MIME-type.
 500          * If that doesn't have results, it tries if there's a rule
 501          * for a more generic type.
 502          */
 503         $hookresults = do_hook("attachment $type0/$type1", $links,
 504                                $startMessage, $id, $urlMailbox, $ent, $defaultlink,
 505                                $display_filename, $where, $what);
 506         if(count($hookresults[1]) <= 1) {
 507             $hookresults = do_hook("attachment $type0/*", $links,
 508                                    $startMessage, $id, $urlMailbox, $ent, $defaultlink,
 509                                    $display_filename, $where, $what);
 510         }
 511
 512         $links = $hookresults[1];
 513         $defaultlink = $hookresults[6];
 514
 515         $attachments .= '<TR><TD>' .
 516                         '<A HREF="'.$defaultlink.'">'.decodeHeader($display_filename).'</A>&nbsp;</TD>' .
 517                         '<TD><SMALL><b>' . show_readable_size($header->size) .
 518                         '</b>&nbsp;&nbsp;</small></TD>' .
 519                         "<TD><SMALL>[ $type0/$type1 ]&nbsp;</SMALL></TD>" .
 520                         '<TD><SMALL>';
 521         $attachments .= '<b>' . $description . '</b>';
 522         $attachments .= '</SMALL></TD><TD><SMALL>&nbsp;';
 523
 524         $skipspaces = 1;
 525         foreach ($links as $val) {
 526             if ($skipspaces) {
 527                 $skipspaces = 0;
 528             } else {
 529                 $attachments .= '&nbsp;&nbsp;|&nbsp;&nbsp;';
 530             }
 531             $attachments .= '<a href="' . $val['href'] . '">' .  $val['text'] . '</a>';
 532         }
 533         unset($links);
 534         $attachments .= "</TD></TR>\n";
 535     }
 536     $attachmentadd = do_hook_function('attachments_bottom',$attachments);
 537     if ($attachmentadd != '')
 538         $attachments = $attachmentadd;
 539     return $attachments;
 540 }
 541
 542 function sqimap_base64_decode(&$string) {
 543     $string = str_replace("\r\n", "\n", $string);
 544     $string = base64_decode($string);
 545 }
 546
 547 /* This function decodes the body depending on the encoding type. */
 548 function decodeBody($body, $encoding) {
 549     global $show_html_default;
 550
 551     $body = str_replace("\r\n", "\n", $body);
 552     $encoding = strtolower($encoding);
 553
 554     if ($encoding == 'quoted-printable' ||
 555         $encoding == 'quoted_printable') {
 556         $body = quoted_printable_decode($body);
 557
 558         while (ereg("=\n", $body)) {
 559             $body = ereg_replace ("=\n", '', $body);
 560         }
 561
 562     } else if ($encoding == 'base64') {
 563         $body = base64_decode($body);
 564     }
 565
 566     // All other encodings are returned raw.
 567     return $body;
 568 }
 569
 570 /*
 571  * This functions decode strings that is encoded according to
 572  * RFC1522 (MIME Part Two: Message Header Extensions for Non-ASCII Text).
 573  * Patched by Christian Schmidt <christian@ostenfeld.dk>  23/03/2002
 574  */
 575 function decodeHeader ($string, $utfencode=true,$htmlsave=true) {
 576     global $languages, $squirrelmail_language;
 577     if (is_array($string)) {
 578         $string = implode("\n", $string);
 579     }
 580
 581     if (isset($languages[$squirrelmail_language]['XTRA_CODE']) &&
 582         function_exists($languages[$squirrelmail_language]['XTRA_CODE'])) {
 583         $string = $languages[$squirrelmail_language]['XTRA_CODE']('decodeheader', $string);
 584         // Do we need to return at this point?
 585         // return $string;
 586     }
 587     $i = 0;
 588     $iLastMatch = -2;
 589     $encoded = false;
 590
 591     $aString = explode(' ',$string);
 592     $ret = '';
 593     foreach ($aString as $chunk) {
 594         if ($encoded && $chunk === '') {
 595             continue;
 596         } elseif ($chunk === '') {
 597             $ret .= ' ';
 598             continue;
 599         }
 600         $encoded = false;
 601         /* if encoded words are not separated by a linear-space-white we still catch them */
 602         $j = $i-1;
 603 //      if ($chunk{0} === '=') { /* performance, saves an unnessecarry preg call */
 604         while ($match = preg_match('/^(.*)=\?([^?]*)\?(Q|B)\?([^?]*)\?=(.*)$/Ui',$chunk,$res)) {
 605             /* if the last chunk isn't an encoded string then put back the space, otherwise don't */
 606             if ($iLastMatch !== $j) {
 607                 if ($htmlsave) {
 608                     $ret .= '&nbsp;';
 609                 } else {
 610                     $ret .= ' ';
 611                 }
 612             }
 613             $iLastMatch = $i;
 614             $j = $i;
 615             $ret .= $res[1];
 616             $encoding = ucfirst($res[3]);
 617             switch ($encoding)
 618             {
 619             case 'B':
 620                 $replace = base64_decode($res[4]);
 621                 $ret .= charset_decode($res[2],$replace);
 622                 break;
 623             case 'Q':
 624                 $replace = str_replace('_', ' ', $res[4]);
 625                 $replace = preg_replace('/=([0-9a-f]{2})/ie', 'chr(hexdec("\1"))',
 626                                     $replace);
 627                 /* Only encode into entities by default. Some places
 628                  * don't need the encoding, like the compose form.
 629                  */
 630                 if ($utfencode) {
 631                     $replace = charset_decode($res[2], $replace);
 632                 } else {
 633                     if ($htmlsave) {
 634                         $replace = htmlspecialchars($replace);
 635                     }
 636                 }
 637                 $ret .= $replace;
 638                 break;
 639             default:
 640                 break;
 641             }
 642             $chunk = $res[5];
 643             $encoded = true;
 644         }
 645 //      }
 646         if (!$encoded) {
 647             if ($htmlsave) {
 648                 $ret .= '&nbsp;';
 649             } else {
 650                 $ret .= ' ';
 651             }
 652         }
 653
 654         if (!$encoded && $htmlsave) {
 655             $ret .= htmlspecialchars($chunk);
 656         } else {
 657             $ret .= $chunk;
 658         }
 659         ++$i;
 660     }
 661     /* remove the first added space */
 662     if ($ret) {
 663         if ($htmlsave) {
 664             $ret = substr($ret,6);
 665         } else {
 666             $ret = substr($ret,1);
 667         }
 668     }
 669
 670     return $ret;
 671 }
 672
 673 /*
 674  * Encode a string according to RFC 1522 for use in headers if it
 675  * contains 8-bit characters or anything that looks like it should
 676  * be encoded.
 677  */
 678 function encodeHeader ($string) {
 679     global $default_charset, $languages, $squirrelmail_language;
 680
 681     if (isset($languages[$squirrelmail_language]['XTRA_CODE']) &&
 682         function_exists($languages[$squirrelmail_language]['XTRA_CODE'])) {
 683         return  $languages[$squirrelmail_language]['XTRA_CODE']('encodeheader', $string);
 684     }
 685     if (strtolower($default_charset) == 'iso-8859-1') {
 686         $string = str_replace("\240",' ',$string);
 687     }
 688
 689     // Encode only if the string contains 8-bit characters or =?
 690     $j = strlen($string);
 691     $max_l = 75 - strlen($default_charset) - 7;
 692     $aRet = array();
 693     $ret = '';
 694     $iEncStart = $enc_init = false;
 695     $cur_l = $iOffset = 0;
 696     for($i = 0; $i < $j; ++$i) {
 697         switch($string{$i})
 698         {
 699         case '=':
 700         case '<':
 701         case '>':
 702         case ',':
 703         case '?':
 704         case '_':
 705             if ($iEncStart === false) {
 706                 $iEncStart = $i;
 707             }
 708             $cur_l+=3;
 709             if ($cur_l > ($max_l-2)) {
 710                 /* if there is an stringpart that doesn't need encoding, add it */
 711                 $aRet[] = substr($string,$iOffset,$iEncStart-$iOffset);
 712                 $aRet[] = "=?$default_charset?Q?$ret?=";
 713                 $iOffset = $i;
 714                 $cur_l = 0;
 715                 $ret = '';
 716                 $iEncStart = false;
 717             } else {
 718                 $ret .= sprintf("=%02X",ord($string{$i}));
 719             }
 720             break;
 721         case '(':
 722         case ')':
 723             if ($iEncStart !== false) {
 724                 $aRet[] = substr($string,$iOffset,$iEncStart-$iOffset);
 725                 $aRet[] = "=?$default_charset?Q?$ret?=";
 726                 $iOffset = $i;
 727                 $cur_l = 0;
 728                 $ret = '';
 729                 $iEncStart = false;
 730             }
 731             break;
 732         case ' ':
 733             if ($iEncStart !== false) {
 734                 $cur_l++;
 735                 if ($cur_l > $max_l) {
 736                     $aRet[] = substr($string,$iOffset,$iEncStart-$iOffset);
 737                     $aRet[] = "=?$default_charset?Q?$ret?=";
 738                     $iOffset = $i;
 739                     $cur_l = 0;
 740                     $ret = '';
 741                     $iEncStart = false;
 742                 } else {
 743                     $ret .= '_';
 744                 }
 745             }
 746             break;
 747         default:
 748             $k = ord($string{$i});
 749             if ($k > 126) {
 750                 if ($iEncStart === false) {
 751                     // do not start encoding in the middle of a string, also take the rest of the word.
 752                     $sLeadString = substr($string,0,$i);
 753                     $aLeadString = explode(' ',$sLeadString);
 754                     $sToBeEncoded = array_pop($aLeadString);
 755                     $iEncStart = $i - strlen($sToBeEncoded);
 756                     $ret .= $sToBeEncoded;
 757                     $cur_l += strlen($sToBeEncoded);
 758                 }
 759                 $cur_l += 3;
 760                 /* first we add the encoded string that reached it's max size */
 761                 if ($cur_l > ($max_l-2)) {
 762                     $aRet[] = substr($string,$iOffset,$iEncStart-$iOffset);
 763                     $aRet[] = "=?$default_charset?Q?$ret?= "; /* the next part is also encoded => separate by space */
 764                     $cur_l = 3;
 765                     $ret = '';
 766                     $iOffset = $i;
 767                     $iEncStart = $i;
 768                 }
 769                 $enc_init = true;
 770                 $ret .= sprintf("=%02X", $k);
 771             } else {
 772                 if ($iEncStart !== false) {
 773                     $cur_l++;
 774                     if ($cur_l > $max_l) {
 775                         $aRet[] = substr($string,$iOffset,$iEncStart-$iOffset);
 776                         $aRet[] = "=?$default_charset?Q?$ret?=";
 777                         $iEncStart = false;
 778                         $iOffset = $i;
 779                         $cur_l = 0;
 780                         $ret = '';
 781                     } else {
 782                         $ret .= $string{$i};
 783                     }
 784                 }
 785             }
 786             break;
 787         }
 788     }
 789
 790     if ($enc_init) {
 791         if ($iEncStart !== false) {
 792             $aRet[] = substr($string,$iOffset,$iEncStart-$iOffset);
 793             $aRet[] = "=?$default_charset?Q?$ret?=";
 794         } else {
 795             $aRet[] = substr($string,$iOffset);
 796         }
 797         $string = implode('',$aRet);
 798     }
 799     return $string;
 800 }
 801
 802 /* This function trys to locate the entity_id of a specific mime element */
 803 function find_ent_id($id, $message) {
 804     for ($i = 0, $ret = ''; $ret == '' && $i < count($message->entities); $i++) {
 805         if ($message->entities[$i]->header->type0 == 'multipart')  {
 806             $ret = find_ent_id($id, $message->entities[$i]);
 807         } else {
 808             if (strcasecmp($message->entities[$i]->header->id, $id) == 0) {
 809 //                if (sq_check_save_extension($message->entities[$i])) {
 810                     return $message->entities[$i]->entity_id;
 811 //                }
 812             }
 813         }
 814     }
 815     return $ret;
 816 }
 817
 818 function sq_check_save_extension($message) {
 819     $filename = $message->getFilename();
 820     $ext = substr($filename, strrpos($filename,'.')+1);
 821     $save_extensions = array('jpg','jpeg','gif','png','bmp');
 822     return in_array($ext, $save_extensions);
 823 }
 824
 825
 826 /**
 827  ** HTMLFILTER ROUTINES
 828  */
 829
 830 /**
 831  * This function returns the final tag out of the tag name, an array
 832  * of attributes, and the type of the tag. This function is called by
 833  * sq_sanitize internally.
 834  *
 835  * @param  $tagname  the name of the tag.
 836  * @param  $attary   the array of attributes and their values
 837  * @param  $tagtype  The type of the tag (see in comments).
 838  * @return           a string with the final tag representation.
 839  */
 840 function sq_tagprint($tagname, $attary, $tagtype){
 841     $me = 'sq_tagprint';
 842
 843     if ($tagtype == 2){
 844         $fulltag = '</' . $tagname . '>';
 845     } else {
 846         $fulltag = '<' . $tagname;
 847         if (is_array($attary) && sizeof($attary)){
 848             $atts = Array();
 849             while (list($attname, $attvalue) = each($attary)){
 850                 array_push($atts, "$attname=$attvalue");
 851             }
 852             $fulltag .= ' ' . join(" ", $atts);
 853         }
 854         if ($tagtype == 3){
 855             $fulltag .= ' /';
 856         }
 857         $fulltag .= '>';
 858     }
 859     return $fulltag;
 860 }
 861
 862 /**
 863  * A small helper function to use with array_walk. Modifies a by-ref
 864  * value and makes it lowercase.
 865  *
 866  * @param  $val a value passed by-ref.
 867  * @return      void since it modifies a by-ref value.
 868  */
 869 function sq_casenormalize(&$val){
 870     $val = strtolower($val);
 871 }
 872
 873 /**
 874  * This function skips any whitespace from the current position within
 875  * a string and to the next non-whitespace value.
 876  *
 877  * @param  $body   the string
 878  * @param  $offset the offset within the string where we should start
 879  *                 looking for the next non-whitespace character.
 880  * @return         the location within the $body where the next
 881  *                 non-whitespace char is located.
 882  */
 883 function sq_skipspace($body, $offset){
 884     $me = 'sq_skipspace';
 885     preg_match('/^(\s*)/s', substr($body, $offset), $matches);
 886     if (sizeof($matches{1})){
 887         $count = strlen($matches{1});
 888         $offset += $count;
 889     }
 890     return $offset;
 891 }
 892
 893 /**
 894  * This function looks for the next character within a string.  It's
 895  * really just a glorified "strpos", except it catches if failures
 896  * nicely.
 897  *
 898  * @param  $body   The string to look for needle in.
 899  * @param  $offset Start looking from this position.
 900  * @param  $needle The character/string to look for.
 901  * @return         location of the next occurance of the needle, or
 902  *                 strlen($body) if needle wasn't found.
 903  */
 904 function sq_findnxstr($body, $offset, $needle){
 905     $me  = 'sq_findnxstr';
 906     $pos = strpos($body, $needle, $offset);
 907     if ($pos === FALSE){
 908         $pos = strlen($body);
 909     }
 910     return $pos;
 911 }
 912
 913 /**
 914  * This function takes a PCRE-style regexp and tries to match it
 915  * within the string.
 916  *
 917  * @param  $body   The string to look for needle in.
 918  * @param  $offset Start looking from here.
 919  * @param  $reg    A PCRE-style regex to match.
 920  * @return         Returns a false if no matches found, or an array
 921  *                 with the following members:
 922  *                 - integer with the location of the match within $body
 923  *                 - string with whatever content between offset and the match
 924  *                 - string with whatever it is we matched
 925  */
 926 function sq_findnxreg($body, $offset, $reg){
 927     $me = 'sq_findnxreg';
 928     $matches = Array();
 929     $retarr = Array();
 930     preg_match("%^(.*?)($reg)%si", substr($body, $offset), $matches);
 931     if (!isset($matches{0}) || !$matches{0}){
 932         $retarr = false;
 933     } else {
 934         $retarr{0} = $offset + strlen($matches{1});
 935         $retarr{1} = $matches{1};
 936         $retarr{2} = $matches{2};
 937     }
 938     return $retarr;
 939 }
 940
 941 /**
 942  * This function looks for the next tag.
 943  *
 944  * @param  $body   String where to look for the next tag.
 945  * @param  $offset Start looking from here.
 946  * @return         false if no more tags exist in the body, or
 947  *                 an array with the following members:
 948  *                 - string with the name of the tag
 949  *                 - array with attributes and their values
 950  *                 - integer with tag type (1, 2, or 3)
 951  *                 - integer where the tag starts (starting "<")
 952  *                 - integer where the tag ends (ending ">")
 953  *                 first three members will be false, if the tag is invalid.
 954  */
 955 function sq_getnxtag($body, $offset){
 956     $me = 'sq_getnxtag';
 957     if ($offset > strlen($body)){
 958         return false;
 959     }
 960     $lt = sq_findnxstr($body, $offset, "<");
 961     if ($lt == strlen($body)){
 962         return false;
 963     }
 964     /**
 965      * We are here:
 966      * blah blah <tag attribute="value">
 967      * \---------^
 968      */
 969     $pos = sq_skipspace($body, $lt+1);
 970     if ($pos >= strlen($body)){
 971         return Array(false, false, false, $lt, strlen($body));
 972     }
 973     /**
 974      * There are 3 kinds of tags:
 975      * 1. Opening tag, e.g.:
 976      *    <a href="blah">
 977      * 2. Closing tag, e.g.:
 978      *    </a>
 979      * 3. XHTML-style content-less tag, e.g.:
 980      *    <img src="blah"/>
 981      */
 982     $tagtype = false;
 983     switch (substr($body, $pos, 1)){
 984         case '/':
 985             $tagtype = 2;
 986             $pos++;
 987             break;
 988         case '!':
 989             /**
 990              * A comment or an SGML declaration.
 991              */
 992             if (substr($body, $pos+1, 2) == "--"){
 993                 $gt = strpos($body, "-->", $pos);
 994                 if ($gt === false){
 995                     $gt = strlen($body);
 996                 } else {
 997                     $gt += 2;
 998                 }
 999                 return Array(false, false, false, $lt, $gt);
1000             } else {
1001                 $gt = sq_findnxstr($body, $pos, ">");
1002                 return Array(false, false, false, $lt, $gt);
1003             }
1004             break;
1005         default:
1006             /**
1007              * Assume tagtype 1 for now. If it's type 3, we'll switch values
1008              * later.
1009              */
1010             $tagtype = 1;
1011             break;
1012     }
1013
1014     $tag_start = $pos;
1015     $tagname = '';
1016     /**
1017      * Look for next [\W-_], which will indicate the end of the tag name.
1018      */
1019     $regary = sq_findnxreg($body, $pos, "[^\w\-_]");
1020     if ($regary == false){
1021         return Array(false, false, false, $lt, strlen($body));
1022     }
1023     list($pos, $tagname, $match) = $regary;
1024     $tagname = strtolower($tagname);
1025
1026     /**
1027      * $match can be either of these:
1028      * '>'  indicating the end of the tag entirely.
1029      * '\s' indicating the end of the tag name.
1030      * '/'  indicating that this is type-3 xhtml tag.
1031      *
1032      * Whatever else we find there indicates an invalid tag.
1033      */
1034     switch ($match){
1035         case '/':
1036             /**
1037              * This is an xhtml-style tag with a closing / at the
1038              * end, like so: <img src="blah"/>. Check if it's followed
1039              * by the closing bracket. If not, then this tag is invalid
1040              */
1041             if (substr($body, $pos, 2) == "/>"){
1042                 $pos++;
1043                 $tagtype = 3;
1044             } else {
1045                 $gt = sq_findnxstr($body, $pos, ">");
1046                 $retary = Array(false, false, false, $lt, $gt);
1047                 return $retary;
1048             }
1049         case '>':
1050             return Array($tagname, false, $tagtype, $lt, $pos);
1051             break;
1052         default:
1053             /**
1054              * Check if it's whitespace
1055              */
1056             if (!preg_match('/\s/', $match)){
1057                 /**
1058                  * This is an invalid tag! Look for the next closing ">".
1059                  */
1060                 $gt = sq_findnxstr($body, $lt, ">");
1061                 return Array(false, false, false, $lt, $gt);
1062             }
1063             break;
1064     }
1065
1066     /**
1067      * At this point we're here:
1068      * <tagname  attribute='blah'>
1069      * \-------^
1070      *
1071      * At this point we loop in order to find all attributes.
1072      */
1073     $attname = '';
1074     $atttype = false;
1075     $attary = Array();
1076
1077     while ($pos <= strlen($body)){
1078         $pos = sq_skipspace($body, $pos);
1079         if ($pos == strlen($body)){
1080             /**
1081              * Non-closed tag.
1082              */
1083             return Array(false, false, false, $lt, $pos);
1084         }
1085         /**
1086          * See if we arrived at a ">" or "/>", which means that we reached
1087          * the end of the tag.
1088          */
1089         $matches = Array();
1090         if (preg_match("%^(\s*)(>|/>)%s", substr($body, $pos), $matches)) {
1091             /**
1092              * Yep. So we did.
1093              */
1094             $pos += strlen($matches{1});
1095             if ($matches{2} == "/>"){
1096                 $tagtype = 3;
1097                 $pos++;
1098             }
1099             return Array($tagname, $attary, $tagtype, $lt, $pos);
1100         }
1101
1102         /**
1103          * There are several types of attributes, with optional
1104          * [:space:] between members.
1105          * Type 1:
1106          *   attrname[:space:]=[:space:]'CDATA'
1107          * Type 2:
1108          *   attrname[:space:]=[:space:]"CDATA"
1109          * Type 3:
1110          *   attr[:space:]=[:space:]CDATA
1111          * Type 4:
1112          *   attrname
1113          *
1114          * We leave types 1 and 2 the same, type 3 we check for
1115          * '"' and convert to "&quot" if needed, then wrap in
1116          * double quotes. Type 4 we convert into:
1117          * attrname="yes".
1118          */
1119         $regary = sq_findnxreg($body, $pos, "[^:\w\-_]");
1120         if ($regary == false){
1121             /**
1122              * Looks like body ended before the end of tag.
1123              */
1124             return Array(false, false, false, $lt, strlen($body));
1125         }
1126         list($pos, $attname, $match) = $regary;
1127         $attname = strtolower($attname);
1128         /**
1129          * We arrived at the end of attribute name. Several things possible
1130          * here:
1131          * '>'  means the end of the tag and this is attribute type 4
1132          * '/'  if followed by '>' means the same thing as above
1133          * '\s' means a lot of things -- look what it's followed by.
1134          *      anything else means the attribute is invalid.
1135          */
1136         switch($match){
1137             case '/':
1138                 /**
1139                  * This is an xhtml-style tag with a closing / at the
1140                  * end, like so: <img src="blah"/>. Check if it's followed
1141                  * by the closing bracket. If not, then this tag is invalid
1142                  */
1143                 if (substr($body, $pos, 2) == "/>"){
1144                     $pos++;
1145                     $tagtype = 3;
1146                 } else {
1147                     $gt = sq_findnxstr($body, $pos, ">");
1148                     $retary = Array(false, false, false, $lt, $gt);
1149                     return $retary;
1150                 }
1151             case '>':
1152                 $attary{$attname} = '"yes"';
1153                 return Array($tagname, $attary, $tagtype, $lt, $pos);
1154                 break;
1155             default:
1156                 /**
1157                  * Skip whitespace and see what we arrive at.
1158                  */
1159                 $pos = sq_skipspace($body, $pos);
1160                 $char = substr($body, $pos, 1);
1161                 /**
1162                  * Two things are valid here:
1163                  * '=' means this is attribute type 1 2 or 3.
1164                  * \w means this was attribute type 4.
1165                  * anything else we ignore and re-loop. End of tag and
1166                  * invalid stuff will be caught by our checks at the beginning
1167                  * of the loop.
1168                  */
1169                 if ($char == "="){
1170                     $pos++;
1171                     $pos = sq_skipspace($body, $pos);
1172                     /**
1173                      * Here are 3 possibilities:
1174                      * "'"  attribute type 1
1175                      * '"'  attribute type 2
1176                      * everything else is the content of tag type 3
1177                      */
1178                     $quot = substr($body, $pos, 1);
1179                     if ($quot == "'"){
1180                         $regary = sq_findnxreg($body, $pos+1, "\'");
1181                         if ($regary == false){
1182                             return Array(false, false, false, $lt, strlen($body));
1183                         }
1184                         list($pos, $attval, $match) = $regary;
1185                         $pos++;
1186                         $attary{$attname} = "'" . $attval . "'";
1187                     } else if ($quot == '"'){
1188                         $regary = sq_findnxreg($body, $pos+1, '\"');
1189                         if ($regary == false){
1190                             return Array(false, false, false, $lt, strlen($body));
1191                         }
1192                         list($pos, $attval, $match) = $regary;
1193                         $pos++;
1194                         $attary{$attname} = '"' . $attval . '"';
1195                     } else {
1196                         /**
1197                          * These are hateful. Look for \s, or >.
1198                          */
1199                         $regary = sq_findnxreg($body, $pos, "[\s>]");
1200                         if ($regary == false){
1201                             return Array(false, false, false, $lt, strlen($body));
1202                         }
1203                         list($pos, $attval, $match) = $regary;
1204                         /**
1205                          * If it's ">" it will be caught at the top.
1206                          */
1207                         $attval = preg_replace("/\"/s", "&quot;", $attval);
1208                         $attary{$attname} = '"' . $attval . '"';
1209                     }
1210                 } else if (preg_match("|[\w/>]|", $char)) {
1211                     /**
1212                      * That was attribute type 4.
1213                      */
1214                     $attary{$attname} = '"yes"';
1215                 } else {
1216                     /**
1217                      * An illegal character. Find next '>' and return.
1218                      */
1219                     $gt = sq_findnxstr($body, $pos, ">");
1220                     return Array(false, false, false, $lt, $gt);
1221                 }
1222                 break;
1223         }
1224     }
1225     /**
1226      * The fact that we got here indicates that the tag end was never
1227      * found. Return invalid tag indication so it gets stripped.
1228      */
1229     return Array(false, false, false, $lt, strlen($body));
1230 }
1231
1232 /**
1233  * This function checks attribute values for entity-encoded values
1234  * and returns them translated into 8-bit strings so we can run
1235  * checks on them.
1236  *
1237  * @param  $attvalue A string to run entity check against.
1238  * @return           Translated value.
1239  */
1240 function sq_deent($attvalue){
1241     $me = 'sq_deent';
1242     /**
1243      * See if we have to run the checks first. All entities must start
1244      * with "&".
1245      */
1246     if (strpos($attvalue, "&") === false){
1247         return $attvalue;
1248     }
1249     /**
1250      * Check named entities first.
1251      */
1252     $trans = get_html_translation_table(HTML_ENTITIES);
1253     /**
1254      * Leave &quot; in, as it can mess us up.
1255      */
1256     $trans = array_flip($trans);
1257     unset($trans{"&quot;"});
1258     while (list($ent, $val) = each($trans)){
1259         $attvalue = preg_replace("/$ent*(\W)/si", "$val\\1", $attvalue);
1260     }
1261     /**
1262      * Now translate numbered entities from 1 to 255 if needed.
1263      */
1264     if (strpos($attvalue, "#") !== false){
1265         $omit = Array(34, 39);
1266         for ($asc=1; $asc<256; $asc++){
1267             if (!in_array($asc, $omit)){
1268                 $chr = chr($asc);
1269                 $attvalue = preg_replace("/\&#0*$asc;*(\D)/si", "$chr\\1",
1270                                          $attvalue);
1271                 $attvalue = preg_replace("/\&#x0*".dechex($asc).";*(\W)/si",
1272                                          "$chr\\1", $attvalue);
1273             }
1274         }
1275     }
1276     return $attvalue;
1277 }
1278
1279 /**
1280  * This function runs various checks against the attributes.
1281  *
1282  * @param  $tagname         String with the name of the tag.
1283  * @param  $attary          Array with all tag attributes.
1284  * @param  $rm_attnames     See description for sq_sanitize
1285  * @param  $bad_attvals     See description for sq_sanitize
1286  * @param  $add_attr_to_tag See description for sq_sanitize
1287  * @param  $message         message object
1288  * @param  $id              message id
1289  * @return                  Array with modified attributes.
1290  */
1291 function sq_fixatts($tagname,
1292                     $attary,
1293                     $rm_attnames,
1294                     $bad_attvals,
1295                     $add_attr_to_tag,
1296                     $message,
1297                     $id,
1298                     $mailbox
1299                     ){
1300     $me = 'sq_fixatts';
1301     while (list($attname, $attvalue) = each($attary)){
1302         /**
1303          * See if this attribute should be removed.
1304          */
1305         foreach ($rm_attnames as $matchtag=>$matchattrs){
1306             if (preg_match($matchtag, $tagname)){
1307                 foreach ($matchattrs as $matchattr){
1308                     if (preg_match($matchattr, $attname)){
1309                         unset($attary{$attname});
1310                         continue;
1311                     }
1312                 }
1313             }
1314         }
1315         /**
1316          * Remove any entities.
1317          */
1318         $attvalue = sq_deent($attvalue);
1319
1320         /**
1321          * Now let's run checks on the attvalues.
1322          * I don't expect anyone to comprehend this. If you do,
1323          * get in touch with me so I can drive to where you live and
1324          * shake your hand personally. :)
1325          */
1326         foreach ($bad_attvals as $matchtag=>$matchattrs){
1327             if (preg_match($matchtag, $tagname)){
1328                 foreach ($matchattrs as $matchattr=>$valary){
1329                     if (preg_match($matchattr, $attname)){
1330                         /**
1331                          * There are two arrays in valary.
1332                          * First is matches.
1333                          * Second one is replacements
1334                          */
1335                         list($valmatch, $valrepl) = $valary;
1336                         $newvalue =
1337                             preg_replace($valmatch, $valrepl, $attvalue);
1338                         if ($newvalue != $attvalue){
1339                             $attary{$attname} = $newvalue;
1340                         }
1341                     }
1342                 }
1343             }
1344         }
1345         /**
1346          * Turn cid: urls into http-friendly ones.
1347          */
1348         if (preg_match("/^[\'\"]\s*cid:/si", $attvalue)){
1349             $attary{$attname} = sq_cid2http($message, $id, $attvalue, $mailbox);
1350         }
1351     }
1352     /**
1353      * See if we need to append any attributes to this tag.
1354      */
1355     foreach ($add_attr_to_tag as $matchtag=>$addattary){
1356         if (preg_match($matchtag, $tagname)){
1357             $attary = array_merge($attary, $addattary);
1358         }
1359     }
1360     return $attary;
1361 }
1362
1363 /**
1364  * This function edits the style definition to make them friendly and
1365  * usable in squirrelmail.
1366  *
1367  * @param  $message  the message object
1368  * @param  $id       the message id
1369  * @param  $content  a string with whatever is between <style> and </style>
1370  * @return           a string with edited content.
1371  */
1372 function sq_fixstyle($body, $pos, $message, $id){
1373     global $view_unsafe_images;
1374     $me = 'sq_fixstyle';
1375     $ret = sq_findnxreg($body, $pos, '</\s*style\s*>');
1376     if ($ret == FALSE){
1377         return array(FALSE, strlen($body));
1378     }
1379     $newpos = $ret[0] + strlen($ret[2]);
1380     $content = $ret[1];
1381     /**
1382      * First look for general BODY style declaration, which would be
1383      * like so:
1384      * body {background: blah-blah}
1385      * and change it to .bodyclass so we can just assign it to a <div>
1386      */
1387     $content = preg_replace("|body(\s*\{.*?\})|si", ".bodyclass\\1", $content);
1388     $secremoveimg = '../images/' . _("sec_remove_eng.png");
1389     /**
1390      * Fix url('blah') declarations.
1391      */
1392     $content = preg_replace("|url\s*\(\s*([\'\"])\s*\S+script\s*:.*?([\'\"])\s*\)|si",
1393                             "url(\\1$secremoveimg\\2)", $content);
1394     /**
1395      * Fix url('https*://.*) declarations but only if $view_unsafe_images
1396      * is false.
1397      */
1398     if (!$view_unsafe_images){
1399         $content = preg_replace("|url\s*\(\s*([\'\"])\s*https*:.*?([\'\"])\s*\)|si",
1400                                 "url(\\1$secremoveimg\\2)", $content);
1401     }
1402
1403     /**
1404      * Fix urls that refer to cid:
1405      */
1406     while (preg_match("|url\s*\(\s*([\'\"]\s*cid:.*?[\'\"])\s*\)|si",
1407                       $content, $matches)){
1408         $cidurl = $matches{1};
1409         $httpurl = sq_cid2http($message, $id, $cidurl);
1410         $content = preg_replace("|url\s*\(\s*$cidurl\s*\)|si",
1411                                 "url($httpurl)", $content);
1412     }
1413
1414     /**
1415      * Fix stupid css declarations which lead to vulnerabilities
1416      * in IE.
1417      */
1418     $match   = Array('/expression/i',
1419                      '/behaviou*r/i',
1420                      '/binding/i');
1421     $replace = Array('idiocy', 'idiocy', 'idiocy');
1422     $content = preg_replace($match, $replace, $content);
1423     return array($content, $newpos);
1424 }
1425
1426 /**
1427  * This function converts cid: url's into the ones that can be viewed in
1428  * the browser.
1429  *
1430  * @param  $message  the message object
1431  * @param  $id       the message id
1432  * @param  $cidurl   the cid: url.
1433  * @return           a string with a http-friendly url
1434  */
1435 function sq_cid2http($message, $id, $cidurl, $mailbox){
1436     /**
1437      * Get rid of quotes.
1438      */
1439     $quotchar = substr($cidurl, 0, 1);
1440     $cidurl = str_replace($quotchar, "", $cidurl);
1441     $cidurl = substr(trim($cidurl), 4);
1442     $linkurl = find_ent_id($cidurl, $message);
1443     /* in case of non-save cid links $httpurl should be replaced by a sort of
1444        unsave link image */
1445     $httpurl = '';
1446     if ($linkurl) {
1447         $httpurl = $quotchar . SM_PATH . 'src/download.php?absolute_dl=true&amp;' .
1448                    "passed_id=$id&amp;mailbox=" . urlencode($mailbox) .
1449                    '&amp;ent_id=' . $linkurl . $quotchar;
1450     }
1451     return $httpurl;
1452 }
1453
1454 /**
1455  * This function changes the <body> tag into a <div> tag since we
1456  * can't really have a body-within-body.
1457  *
1458  * @param  $attary  an array of attributes and values of <body>
1459  * @return          a modified array of attributes to be set for <div>
1460  */
1461 function sq_body2div($attary){
1462     $me = 'sq_body2div';
1463     $divattary = Array('class' => "'bodyclass'");
1464     $bgcolor = '#ffffff';
1465     $text = '#000000';
1466     $styledef = '';
1467     if (is_array($attary) && sizeof($attary) > 0){
1468         foreach ($attary as $attname=>$attvalue){
1469             $quotchar = substr($attvalue, 0, 1);
1470             $attvalue = str_replace($quotchar, "", $attvalue);
1471             switch ($attname){
1472                 case 'background':
1473                     $styledef .= "background-image: url('$attvalue'); ";
1474                     break;
1475                 case 'bgcolor':
1476                     $styledef .= "background-color: $attvalue; ";
1477                     break;
1478                 case 'text':
1479                     $styledef .= "color: $attvalue; ";
1480                     break;
1481             }
1482         }
1483         if (strlen($styledef) > 0){
1484             $divattary{"style"} = "\"$styledef\"";
1485         }
1486     }
1487     return $divattary;
1488 }
1489
1490 /**
1491  * This is the main function and the one you should actually be calling.
1492  * There are several variables you should be aware of an which need
1493  * special description.
1494  *
1495  * Since the description is quite lengthy, see it here:
1496  * http://www.mricon.com/html/phpfilter.html
1497  *
1498  * @param $body                 the string with HTML you wish to filter
1499  * @param $tag_list             see description above
1500  * @param $rm_tags_with_content see description above
1501  * @param $self_closing_tags    see description above
1502  * @param $force_tag_closing    see description above
1503  * @param $rm_attnames          see description above
1504  * @param $bad_attvals          see description above
1505  * @param $add_attr_to_tag      see description above
1506  * @param $message              message object
1507  * @param $id                   message id
1508  * @return                      sanitized html safe to show on your pages.
1509  */
1510 function sq_sanitize($body,
1511                      $tag_list,
1512                      $rm_tags_with_content,
1513                      $self_closing_tags,
1514                      $force_tag_closing,
1515                      $rm_attnames,
1516                      $bad_attvals,
1517                      $add_attr_to_tag,
1518                      $message,
1519                      $id,
1520                      $mailbox
1521                      ){
1522     $me = 'sq_sanitize';
1523     $rm_tags = array_shift($tag_list);
1524     /**
1525      * Normalize rm_tags and rm_tags_with_content.
1526      */
1527     @array_walk($tag_list, 'sq_casenormalize');
1528     @array_walk($rm_tags_with_content, 'sq_casenormalize');
1529     @array_walk($self_closing_tags, 'sq_casenormalize');
1530     /**
1531      * See if tag_list is of tags to remove or tags to allow.
1532      * false  means remove these tags
1533      * true   means allow these tags
1534      */
1535     $curpos = 0;
1536     $open_tags = Array();
1537     $trusted = "<!-- begin sanitized html -->\n";
1538     $skip_content = false;
1539     /**
1540      * Take care of netscape's stupid javascript entities like
1541      * &{alert('boo')};
1542      */
1543     $body = preg_replace("/&(\{.*?\};)/si", "&amp;\\1", $body);
1544
1545     while (($curtag = sq_getnxtag($body, $curpos)) != FALSE){
1546         list($tagname, $attary, $tagtype, $lt, $gt) = $curtag;
1547         $free_content = substr($body, $curpos, $lt-$curpos);
1548         /**
1549          * Take care of <style>
1550          */
1551         if ($tagname == "style" && $tagtype == 1){
1552             list($free_content, $curpos) =
1553                 sq_fixstyle($body, $gt+1, $message, $id);
1554             if ($free_content != FALSE){
1555                 $trusted .= sq_tagprint($tagname, $attary, $tagtype);
1556                 $trusted .= $free_content;
1557                 $trusted .= sq_tagprint($tagname, false, 2);
1558             }
1559             continue;
1560         }
1561         if ($skip_content == false){
1562             $trusted .= $free_content;
1563         }
1564         if ($tagname != FALSE){
1565             if ($tagtype == 2){
1566                 if ($skip_content == $tagname){
1567                     /**
1568                      * Got to the end of tag we needed to remove.
1569                      */
1570                     $tagname = false;
1571                     $skip_content = false;
1572                 } else {
1573                     if ($skip_content == false){
1574                         if ($tagname == "body"){
1575                             $tagname = "div";
1576                         } else {
1577                             if (isset($open_tags{$tagname}) &&
1578                                 $open_tags{$tagname} > 0){
1579                                 $open_tags{$tagname}--;
1580                             } else {
1581                                 $tagname = false;
1582                             }
1583                         }
1584                     }
1585                 }
1586             } else {
1587                 /**
1588                  * $rm_tags_with_content
1589                  */
1590                 if ($skip_content == false){
1591                     /**
1592                      * See if this is a self-closing type and change
1593                      * tagtype appropriately.
1594                      */
1595                     if ($tagtype == 1
1596                         && in_array($tagname, $self_closing_tags)){
1597                         $tagtype=3;
1598                     }
1599                     /**
1600                      * See if we should skip this tag and any content
1601                      * inside it.
1602                      */
1603                     if ($tagtype == 1 &&
1604                         in_array($tagname, $rm_tags_with_content)){
1605                         $skip_content = $tagname;
1606                     } else {
1607                         if (($rm_tags == false
1608                              && in_array($tagname, $tag_list)) ||
1609                             ($rm_tags == true &&
1610                              !in_array($tagname, $tag_list))){
1611                             $tagname = false;
1612                         } else {
1613                             if ($tagtype == 1){
1614                                 if (isset($open_tags{$tagname})){
1615                                     $open_tags{$tagname}++;
1616                                 } else {
1617                                     $open_tags{$tagname}=1;
1618                                 }
1619                             }
1620                             /**
1621                              * This is where we run other checks.
1622                              */
1623                             if (is_array($attary) && sizeof($attary) > 0){
1624                                 $attary = sq_fixatts($tagname,
1625                                                      $attary,
1626                                                      $rm_attnames,
1627                                                      $bad_attvals,
1628                                                      $add_attr_to_tag,
1629                                                      $message,
1630                                                      $id,
1631                                                      $mailbox
1632                                                      );
1633                             }
1634                             /**
1635                              * Convert body into div.
1636                              */
1637                             if ($tagname == "body"){
1638                                 $tagname = "div";
1639                                 $attary = sq_body2div($attary, $message, $id);
1640                             }
1641                         }
1642                     }
1643                 }
1644             }
1645             if ($tagname != false && $skip_content == false){
1646                 $trusted .= sq_tagprint($tagname, $attary, $tagtype);
1647             }
1648         }
1649         $curpos = $gt+1;
1650     }
1651     $trusted .= substr($body, $curpos, strlen($body)-$curpos);
1652     if ($force_tag_closing == true){
1653         foreach ($open_tags as $tagname=>$opentimes){
1654             while ($opentimes > 0){
1655                 $trusted .= '</' . $tagname . '>';
1656                 $opentimes--;
1657             }
1658         }
1659         $trusted .= "\n";
1660     }
1661     $trusted .= "<!-- end sanitized html -->\n";
1662     return $trusted;
1663 }
1664
1665 /**
1666  * This is a wrapper function to call html sanitizing routines.
1667  *
1668  * @param  $body  the body of the message
1669  * @param  $id    the id of the message
1670  * @return        a string with html safe to display in the browser.
1671  */
1672 function magicHTML($body, $id, $message, $mailbox = 'INBOX') {
1673     global $attachment_common_show_images, $view_unsafe_images,
1674            $has_unsafe_images;
1675     /**
1676      * Don't display attached images in HTML mode.
1677      */
1678     $attachment_common_show_images = false;
1679     $tag_list = Array(
1680                       false,
1681                       "object",
1682                       "meta",
1683                       "html",
1684                       "head",
1685                       "base",
1686                       "link",
1687                       "frame",
1688                       "iframe"
1689                       );
1690
1691     $rm_tags_with_content = Array(
1692                                   "script",
1693                                   "applet",
1694                                   "embed",
1695                                   "title"
1696                                   );
1697
1698     $self_closing_tags =  Array(
1699                                 "img",
1700                                 "br",
1701                                 "hr",
1702                                 "input"
1703                                 );
1704
1705     $force_tag_closing = false;
1706
1707     $rm_attnames = Array(
1708                          "/.*/" =>
1709                          Array(
1710                                "/target/i",
1711                                "/^on.*/i",
1712                                "/^dynsrc/i",
1713                                "/^data.*/i",
1714                                "/^lowsrc.*/i"
1715                                )
1716                          );
1717
1718     $secremoveimg = "../images/" . _("sec_remove_eng.png");
1719     $bad_attvals = Array(
1720         "/.*/" =>
1721             Array(
1722                 "/^src|background/i" =>
1723                     Array(
1724                           Array(
1725                                 "|^([\'\"])\s*\.\./.*([\'\"])|si",
1726                                 "/^([\'\"])\s*\S+script\s*:.*([\'\"])/si",
1727                                 "/^([\'\"])\s*mocha\s*:*.*([\'\"])/si",
1728                                 "/^([\'\"])\s*about\s*:.*([\'\"])/si"
1729                                 ),
1730                           Array(
1731                                 "\\1$secremoveimg\\2",
1732                                 "\\1$secremoveimg\\2",
1733                                 "\\1$secremoveimg\\2",
1734                                 "\\1$secremoveimg\\2"
1735                                 )
1736                         ),
1737                 "/^href|action/i" =>
1738                     Array(
1739                           Array(
1740                                 "|^([\'\"])\s*\.\./.*([\'\"])|si",
1741                                 "/^([\'\"])\s*\S+script\s*:.*([\'\"])/si",
1742                                 "/^([\'\"])\s*mocha\s*:*.*([\'\"])/si",
1743                                 "/^([\'\"])\s*about\s*:.*([\'\"])/si"
1744                                 ),
1745                           Array(
1746                                 "\\1#\\2",
1747                                 "\\1#\\2",
1748                                 "\\1#\\2",
1749                                 "\\1#\\2"
1750                                 )
1751                         ),
1752                 "/^style/i" =>
1753                     Array(
1754                           Array(
1755                                 "/expression/i",
1756                                 "/binding/i",
1757                                 "/behaviou*r/i",
1758                                 "|url\s*\(\s*([\'\"])\s*\.\./.*([\'\"])\s*\)|si",
1759                                 "/url\s*\(\s*([\'\"])\s*\S+script\s*:.*([\'\"])\s*\)/si",
1760                                 "/url\s*\(\s*([\'\"])\s*mocha\s*:.*([\'\"])\s*\)/si",
1761                                 "/url\s*\(\s*([\'\"])\s*about\s*:.*([\'\"])\s*\)/si"
1762                                ),
1763                           Array(
1764                                 "idiocy",
1765                                 "idiocy",
1766                                 "idiocy",
1767                                 "url(\\1#\\2)",
1768                                 "url(\\1#\\2)",
1769                                 "url(\\1#\\2)",
1770                                 "url(\\1#\\2)"
1771                                )
1772                           )
1773                 )
1774         );
1775     if( !sqgetGlobalVar('view_unsafe_images', $view_unsafe_images, SQ_GET) ) {
1776         $view_unsafe_images = false;
1777     }
1778     if (!$view_unsafe_images){
1779         /**
1780          * Remove any references to http/https if view_unsafe_images set
1781          * to false.
1782          */
1783          array_push($bad_attvals{'/.*/'}{'/^src|background/i'}[0],
1784                     '/^([\'\"])\s*https*:.*([\'\"])/si');
1785          array_push($bad_attvals{'/.*/'}{'/^src|background/i'}[1],
1786                     "\\1$secremoveimg\\2");
1787          array_push($bad_attvals{'/.*/'}{'/^style/i'}[0],
1788                     '/url\(([\'\"])\s*https*:.*([\'\"])\)/si');
1789          array_push($bad_attvals{'/.*/'}{'/^style/i'}[1],
1790                     "url(\\1$secremoveimg\\2)");
1791     }
1792
1793     $add_attr_to_tag = Array(
1794                              "/^a$/i" => Array('target'=>'"_new"')
1795                              );
1796     $trusted = sq_sanitize($body,
1797                            $tag_list,
1798                            $rm_tags_with_content,
1799                            $self_closing_tags,
1800                            $force_tag_closing,
1801                            $rm_attnames,
1802                            $bad_attvals,
1803                            $add_attr_to_tag,
1804                            $message,
1805                            $id,
1806                            $mailbox
1807                            );
1808     if (preg_match("|$secremoveimg|i", $trusted)){
1809         $has_unsafe_images = true;
1810     }
1811     return $trusted;
1812 }
1813
1814 ?>