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