class/deliver/Deliver.class.php

   1 <?php
   2
   3 /**
   4  * Deliver.class.php
   5  *
   6  * This contains all the functions needed to send messages through
   7  * a delivery backend.
   8  *
   9  * @author Marc Groot Koerkamp
  10  * @copyright &copy; 1999-2006 The SquirrelMail Project Team
  11  * @license http://opensource.org/licenses/gpl-license.php GNU Public License
  12  * @version $Id$
  13  * @package squirrelmail
  14  */
  15
  16 /**
  17  * Deliver Class - called to actually deliver the message
  18  *
  19  * This class is called by compose.php and other code that needs
  20  * to send messages.  All delivery functionality should be centralized
  21  * in this class.
  22  *
  23  * Do not place UI code in this class, as UI code should be placed in templates
  24  * going forward.
  25  *
  26  * @author  Marc Groot Koerkamp
  27  * @package squirrelmail
  28  */
  29 class Deliver {
  30
  31     /**
  32      * function mail - send the message parts to the SMTP stream
  33      *
  34      * @param Message  $message  Message class to send
  35      * @param resource $stream   file handle to the SMTP stream
  36      *
  37      * @return integer $raw_length
  38      */
  39     function mail($message, $stream=false) {
  40         $rfc822_header = $message->rfc822_header;
  41         if (count($message->entities)) {
  42             $boundary = $this->mimeBoundary();
  43             $rfc822_header->content_type->properties['boundary']='"'.$boundary.'"';
  44         } else {
  45             $boundary='';
  46         }
  47         $raw_length = 0;
  48         $reply_rfc822_header = (isset($message->reply_rfc822_header)
  49                              ? $message->reply_rfc822_header : '');
  50         $header = $this->prepareRFC822_Header($rfc822_header, $reply_rfc822_header, $raw_length);
  51
  52         if ($stream) {
  53             $this->preWriteToStream($header);
  54             $this->writeToStream($stream, $header);
  55         }
  56         $this->writeBody($message, $stream, $raw_length, $boundary);
  57         return $raw_length;
  58     }
  59
  60     /**
  61      * function writeBody - generate and write the mime boundaries around each part to the stream
  62      *
  63      * Recursively formats and writes the MIME boundaries of the $message
  64      * to the output stream.
  65      *
  66      * @param Message   $message      Message object to transform
  67      * @param resource  $stream       SMTP output stream
  68      * @param integer  &$length_raw   raw length of the message (part)
  69      *                                as returned by mail fn
  70      * @param string    $boundary     custom boundary to call, usually for subparts
  71      *
  72      * @return void
  73      */
  74     function writeBody($message, $stream, &$length_raw, $boundary='') {
  75         // calculate boundary in case of multidimensional mime structures
  76         if ($boundary && $message->entity_id && count($message->entities)) {
  77             if (strpos($boundary,'_part_')) {
  78                 $boundary = substr($boundary,0,strpos($boundary,'_part_'));
  79
  80             // the next four lines use strrev to reverse any nested boundaries
  81             // because RFC 2046 (5.1.1) says that if a line starts with the outer
  82             // boundary string (doesn't matter what the line ends with), that
  83             // can be considered a match for the outer boundary; thus the nested
  84             // boundary needs to be unique from the outer one
  85             //
  86             } else if (strpos($boundary,'_trap_')) {
  87                 $boundary = substr(strrev($boundary),0,strpos(strrev($boundary),'_part_'));
  88             }
  89             $boundary_new = strrev($boundary . '_part_'.$message->entity_id);
  90         } else {
  91             $boundary_new = $boundary;
  92         }
  93         if ($boundary && !$message->rfc822_header) {
  94             $s = '--'.$boundary."\r\n";
  95             $s .= $this->prepareMIME_Header($message, $boundary_new);
  96             $length_raw += strlen($s);
  97             if ($stream) {
  98                 $this->preWriteToStream($s);
  99                 $this->writeToStream($stream, $s);
 100             }
 101         }
 102         $this->writeBodyPart($message, $stream, $length_raw);
 103
 104         $last = false;
 105         for ($i=0, $entCount=count($message->entities);$i<$entCount;$i++) {
 106             $msg = $this->writeBody($message->entities[$i], $stream, $length_raw, $boundary_new);
 107             if ($i == $entCount-1) $last = true;
 108         }
 109         if ($boundary && $last) {
 110             $s = "--".$boundary_new."--\r\n\r\n";
 111             $length_raw += strlen($s);
 112             if ($stream) {
 113                 $this->preWriteToStream($s);
 114                 $this->writeToStream($stream, $s);
 115             }
 116         }
 117     }
 118
 119     /**
 120      * function writeBodyPart - write each individual mimepart
 121      *
 122      * Recursively called by WriteBody to write each mime part to the SMTP stream
 123      *
 124      * @param Message   $message      Message object to transform
 125      * @param resource  $stream       SMTP output stream
 126      * @param integer  &$length       length of the message part
 127      *                                as returned by mail fn
 128      *
 129      * @return void
 130      */
 131     function writeBodyPart($message, $stream, &$length) {
 132         if ($message->mime_header) {
 133             $type0 = $message->mime_header->type0;
 134         } else {
 135             $type0 = $message->rfc822_header->content_type->type0;
 136         }
 137
 138         $body_part_trailing = $last = '';
 139         switch ($type0)
 140         {
 141         case 'text':
 142         case 'message':
 143             if ($message->body_part) {
 144                 $body_part = $message->body_part;
 145                 // remove NUL characters
 146                 $body_part = str_replace("\0",'',$body_part);
 147                 $length += $this->clean_crlf($body_part);
 148                 if ($stream) {
 149                     $this->preWriteToStream($body_part);
 150                     $this->writeToStream($stream, $body_part);
 151                 }
 152                 $last = $body_part;
 153             } elseif ($message->att_local_name) {
 154                 $filename = $message->att_local_name;
 155                 $file = fopen ($filename, 'rb');
 156                 while ($body_part = fgets($file, 4096)) {
 157                     // remove NUL characters
 158                     $body_part = str_replace("\0",'',$body_part);
 159                     $length += $this->clean_crlf($body_part);
 160                     if ($stream) {
 161                         $this->preWriteToStream($body_part);
 162                         $this->writeToStream($stream, $body_part);
 163                     }
 164                     $last = $body_part;
 165                 }
 166                 fclose($file);
 167             }
 168             break;
 169         default:
 170             if ($message->body_part) {
 171                 $body_part = $message->body_part;
 172                 // remove NUL characters
 173                 $body_part = str_replace("\0",'',$body_part);
 174                 $length += $this->clean_crlf($body_part);
 175                 if ($stream) {
 176                     $this->writeToStream($stream, $body_part);
 177                 }
 178             } elseif ($message->att_local_name) {
 179                 $filename = $message->att_local_name;
 180                 $file = fopen ($filename, 'rb');
 181                 while ($tmp = fread($file, 570)) {
 182                     $body_part = chunk_split(base64_encode($tmp));
 183                     // Up to 4.3.10 chunk_split always appends a newline,
 184                     // while in 4.3.11 it doesn't if the string to split
 185                     // is shorter than the chunk length.
 186                     if( substr($body_part, -1 , 1 ) != "\n" )
 187                         $body_part .= "\n";
 188                     $length += $this->clean_crlf($body_part);
 189                     if ($stream) {
 190                         $this->writeToStream($stream, $body_part);
 191                     }
 192                 }
 193                 fclose($file);
 194             }
 195             break;
 196         }
 197         $body_part_trailing = '';
 198         if ($last && substr($last,-1) != "\n") {
 199             $body_part_trailing = "\r\n";
 200         }
 201         if ($body_part_trailing) {
 202             $length += strlen($body_part_trailing);
 203             if ($stream) {
 204                 $this->preWriteToStream($body_part_trailing);
 205                 $this->writeToStream($stream, $body_part_trailing);
 206             }
 207         }
 208     }
 209
 210     /**
 211      * function clean_crlf - change linefeeds and newlines to legal characters
 212      *
 213      * The SMTP format only allows CRLF as line terminators.
 214      * This function replaces illegal teminators with the correct terminator.
 215      *
 216      * @param string &$s string to clean linefeeds on
 217      *
 218      * @return void
 219      */
 220     function clean_crlf(&$s) {
 221         $s = str_replace("\r\n", "\n", $s);
 222         $s = str_replace("\r", "\n", $s);
 223         $s = str_replace("\n", "\r\n", $s);
 224         return strlen($s);
 225     }
 226
 227     /**
 228      * function strip_crlf - strip linefeeds and newlines from a string
 229      *
 230      * The SMTP format only allows CRLF as line terminators.
 231      * This function strips all line terminators from the string.
 232      *
 233      * @param string &$s string to clean linefeeds on
 234      *
 235      * @return void
 236      */
 237     function strip_crlf(&$s) {
 238         $s = str_replace("\r\n ", '', $s);
 239         $s = str_replace("\r", '', $s);
 240         $s = str_replace("\n", '', $s);
 241     }
 242
 243     /**
 244      * function preWriteToStream - reserved for extended functionality
 245      *
 246      * This function is not yet implemented.
 247      * Reserved for extended functionality.
 248      *
 249      * @param string &$s string to operate on
 250      *
 251      * @return void
 252      */
 253     function preWriteToStream(&$s) {
 254     }
 255
 256     /**
 257      * function writeToStream - write data to the SMTP stream
 258      *
 259      * @param resource $stream  SMTP output stream
 260      * @param string   $data    string with data to send to the SMTP stream
 261      *
 262      * @return void
 263      */
 264     function writeToStream($stream, $data) {
 265         fputs($stream, $data);
 266     }
 267
 268     /**
 269      * function initStream - reserved for extended functionality
 270      *
 271      * This function is not yet implemented.
 272      * Reserved for extended functionality.
 273      *
 274      * @param Message $message  Message object
 275      * @param string  $host     host name or IP to connect to
 276      * @param string  $user     username to log into the SMTP server with
 277      * @param string  $pass     password to log into the SMTP server with
 278      * @param integer $length
 279      *
 280      * @return handle $stream file handle resource to SMTP stream
 281      */
 282     function initStream($message, $length=0, $host='', $port='', $user='', $pass='') {
 283         return $stream;
 284     }
 285
 286     /**
 287      * function getBCC - reserved for extended functionality
 288      *
 289      * This function is not yet implemented.
 290      * Reserved for extended functionality.
 291      *
 292      */
 293     function getBCC() {
 294         return false;
 295     }
 296
 297     /**
 298      * function prepareMIME_Header - creates the mime header
 299      *
 300      * @param Message $message  Message object to act on
 301      * @param string  $boundary mime boundary from fn MimeBoundary
 302      *
 303      * @return string $header properly formatted mime header
 304      */
 305     function prepareMIME_Header($message, $boundary) {
 306         $mime_header = $message->mime_header;
 307         $rn="\r\n";
 308         $header = array();
 309
 310         $contenttype = 'Content-Type: '. $mime_header->type0 .'/'.
 311                         $mime_header->type1;
 312         if (count($message->entities)) {
 313             $contenttype .= ';' . 'boundary="'.$boundary.'"';
 314         }
 315         if (isset($mime_header->parameters['name'])) {
 316             $contenttype .= '; name="'.
 317             encodeHeader($mime_header->parameters['name']). '"';
 318         }
 319         if (isset($mime_header->parameters['charset'])) {
 320             $charset = $mime_header->parameters['charset'];
 321             $contenttype .= '; charset="'.
 322             encodeHeader($charset). '"';
 323         }
 324
 325         $header[] = $contenttype . $rn;
 326         if ($mime_header->description) {
 327             $header[] = 'Content-Description: ' . $mime_header->description . $rn;
 328         }
 329         if ($mime_header->encoding) {
 330             $header[] = 'Content-Transfer-Encoding: ' . $mime_header->encoding . $rn;
 331         } else {
 332             if ($mime_header->type0 == 'text' || $mime_header->type0 == 'message') {
 333                 $header[] = 'Content-Transfer-Encoding: 8bit' .  $rn;
 334             } else {
 335                 $header[] = 'Content-Transfer-Encoding: base64' .  $rn;
 336             }
 337         }
 338         if ($mime_header->id) {
 339             $header[] = 'Content-ID: ' . $mime_header->id . $rn;
 340         }
 341         if ($mime_header->disposition) {
 342             $disposition = $mime_header->disposition;
 343             $contentdisp = 'Content-Disposition: ' . $disposition->name;
 344             if ($disposition->getProperty('filename')) {
 345                 $contentdisp .= '; filename="'.
 346                 encodeHeader($disposition->getProperty('filename')). '"';
 347             }
 348             $header[] = $contentdisp . $rn;
 349         }
 350         if ($mime_header->md5) {
 351             $header[] = 'Content-MD5: ' . $mime_header->md5 . $rn;
 352         }
 353         if ($mime_header->language) {
 354             $header[] = 'Content-Language: ' . $mime_header->language . $rn;
 355         }
 356
 357         $cnt = count($header);
 358         $hdr_s = '';
 359         for ($i = 0 ; $i < $cnt ; $i++)    {
 360             $hdr_s .= $this->foldLine($header[$i], 78,str_pad('',4));
 361         }
 362         $header = $hdr_s;
 363         $header .= $rn; /* One blank line to separate mimeheader and body-entity */
 364         return $header;
 365     }
 366
 367     /**
 368      * function prepareRFC822_Header - prepares the RFC822 header string from Rfc822Header object(s)
 369      *
 370      * This function takes the Rfc822Header object(s) and formats them
 371      * into the RFC822Header string to send to the SMTP server as part
 372      * of the SMTP message.
 373      *
 374      * @param Rfc822Header  $rfc822_header
 375      * @param Rfc822Header  $reply_rfc822_header
 376      * @param integer      &$raw_length length of the message
 377      *
 378      * @return string $header
 379      */
 380     function prepareRFC822_Header($rfc822_header, $reply_rfc822_header, &$raw_length) {
 381         global $domain, $version, $username, $encode_header_key,
 382                $edit_identity, $hide_auth_header;
 383
 384         /* if server var SERVER_NAME not available, use $domain */
 385         if(!sqGetGlobalVar('SERVER_NAME', $SERVER_NAME, SQ_SERVER)) {
 386             $SERVER_NAME = $domain;
 387         }
 388
 389         sqGetGlobalVar('REMOTE_ADDR', $REMOTE_ADDR, SQ_SERVER);
 390         sqGetGlobalVar('REMOTE_PORT', $REMOTE_PORT, SQ_SERVER);
 391         sqGetGlobalVar('REMOTE_HOST', $REMOTE_HOST, SQ_SERVER);
 392         sqGetGlobalVar('HTTP_VIA',    $HTTP_VIA,    SQ_SERVER);
 393         sqGetGlobalVar('HTTP_X_FORWARDED_FOR', $HTTP_X_FORWARDED_FOR, SQ_SERVER);
 394
 395         $rn = "\r\n";
 396
 397         /* This creates an RFC 822 date */
 398         $date = date('D, j M Y H:i:s ', time()) . $this->timezone();
 399         /* Create a message-id */
 400         $message_id = '<' . $REMOTE_PORT . '.';
 401         if (isset($encode_header_key) && trim($encode_header_key)!='') {
 402             // use encrypted form of remote address
 403             $message_id.= OneTimePadEncrypt($this->ip2hex($REMOTE_ADDR),base64_encode($encode_header_key));
 404         } else {
 405             $message_id.= $REMOTE_ADDR;
 406         }
 407         $message_id .= '.' . time() . '.squirrel@' . $SERVER_NAME .'>';
 408         /* Make an RFC822 Received: line */
 409         if (isset($REMOTE_HOST)) {
 410             $received_from = "$REMOTE_HOST ([$REMOTE_ADDR])";
 411         } else {
 412             $received_from = $REMOTE_ADDR;
 413         }
 414         if (isset($HTTP_VIA) || isset ($HTTP_X_FORWARDED_FOR)) {
 415             if (!isset($HTTP_X_FORWARDED_FOR) || $HTTP_X_FORWARDED_FOR == '') {
 416                 $HTTP_X_FORWARDED_FOR = 'unknown';
 417             }
 418             $received_from .= " (proxying for $HTTP_X_FORWARDED_FOR)";
 419         }
 420         $header = array();
 421
 422         /**
 423          * SquirrelMail header
 424          *
 425          * This Received: header provides information that allows to track
 426          * user and machine that was used to send email. Don't remove it
 427          * unless you understand all possible forging issues or your
 428          * webmail installation does not prevent changes in user's email address.
 429          * See SquirrelMail bug tracker #847107 for more details about it.
 430          *
 431          * Add $hide_squirrelmail_header as a candidate for config_local.php
 432          * to allow completely hiding SquirrelMail participation in message
 433          * processing; This is dangerous, especially if users can modify their
 434          * account information, as it makes mapping a sent message back to the
 435          * original sender almost impossible.
 436          */
 437         $show_sm_header = ( defined('hide_squirrelmail_header') ? ! hide_squirrelmail_header : 1 );
 438
 439         if ( $show_sm_header ) {
 440           if (isset($encode_header_key) &&
 441             trim($encode_header_key)!='') {
 442             // use encoded headers, if encryption key is set and not empty
 443             $header[] = 'X-Squirrel-UserHash: '.OneTimePadEncrypt($username,base64_encode($encode_header_key)).$rn;
 444             $header[] = 'X-Squirrel-FromHash: '.OneTimePadEncrypt($this->ip2hex($REMOTE_ADDR),base64_encode($encode_header_key)).$rn;
 445             if (isset($HTTP_X_FORWARDED_FOR))
 446                 $header[] = 'X-Squirrel-ProxyHash:'.OneTimePadEncrypt($this->ip2hex($HTTP_X_FORWARDED_FOR),base64_encode($encode_header_key)).$rn;
 447           } else {
 448             // use default received headers
 449             $header[] = "Received: from $received_from" . $rn;
 450             if ($edit_identity || ! isset($hide_auth_header) || ! $hide_auth_header)
 451                 $header[] = "        (SquirrelMail authenticated user $username)" . $rn;
 452             $header[] = "        by $SERVER_NAME with HTTP;" . $rn;
 453             $header[] = "        $date" . $rn;
 454           }
 455         }
 456
 457         /* Insert the rest of the header fields */
 458         $header[] = 'Message-ID: '. $message_id . $rn;
 459         if (is_object($reply_rfc822_header) &&
 460             isset($reply_rfc822_header->message_id) &&
 461             $reply_rfc822_header->message_id) {
 462             $rep_message_id = $reply_rfc822_header->message_id;
 463         //        $this->strip_crlf($message_id);
 464             $header[] = 'In-Reply-To: '.$rep_message_id . $rn;
 465             $references = $this->calculate_references($reply_rfc822_header);
 466             $header[] = 'References: '.$references . $rn;
 467         }
 468         $header[] = "Date: $date" . $rn;
 469         $header[] = 'Subject: '.encodeHeader($rfc822_header->subject) . $rn;
 470         $header[] = 'From: '. $rfc822_header->getAddr_s('from',",$rn ",true) . $rn;
 471
 472         // folding address list [From|To|Cc|Bcc] happens by using ",$rn<space>"
 473         // as delimiter
 474         // Do not use foldLine for that.
 475
 476         // RFC2822 if from contains more then 1 address
 477         if (count($rfc822_header->from) > 1) {
 478             $header[] = 'Sender: '. $rfc822_header->getAddr_s('sender',',',true) . $rn;
 479         }
 480         if (count($rfc822_header->to)) {
 481             $header[] = 'To: '. $rfc822_header->getAddr_s('to',",$rn ",true) . $rn;
 482         }
 483         if (count($rfc822_header->cc)) {
 484             $header[] = 'Cc: '. $rfc822_header->getAddr_s('cc',",$rn ",true) . $rn;
 485         }
 486         if (count($rfc822_header->reply_to)) {
 487             $header[] = 'Reply-To: '. $rfc822_header->getAddr_s('reply_to',',',true) . $rn;
 488         }
 489         /* Sendmail should return true. Default = false */
 490         $bcc = $this->getBcc();
 491         if (count($rfc822_header->bcc)) {
 492             $s = 'Bcc: '. $rfc822_header->getAddr_s('bcc',",$rn ",true) . $rn;
 493             if (!$bcc) {
 494                 $raw_length += strlen($s);
 495             } else {
 496                 $header[] = $s;
 497             }
 498         }
 499         /* Identify SquirrelMail */
 500         $header[] = 'User-Agent: SquirrelMail/' . $version . $rn;
 501         /* Do the MIME-stuff */
 502         $header[] = 'MIME-Version: 1.0' . $rn;
 503         $contenttype = 'Content-Type: '. $rfc822_header->content_type->type0 .'/'.
 504                                          $rfc822_header->content_type->type1;
 505         if (count($rfc822_header->content_type->properties)) {
 506             foreach ($rfc822_header->content_type->properties as $k => $v) {
 507                 if ($k && $v) {
 508                     $contenttype .= ';' .$k.'='.$v;
 509                 }
 510             }
 511         }
 512         $header[] = $contenttype . $rn;
 513         if ($encoding = $rfc822_header->encoding) {
 514             $header[] = 'Content-Transfer-Encoding: ' . $encoding .  $rn;
 515         }
 516         if ($rfc822_header->dnt) {
 517             $dnt = $rfc822_header->getAddr_s('dnt');
 518             /* Pegasus Mail */
 519             $header[] = 'X-Confirm-Reading-To: '.$dnt. $rn;
 520             /* RFC 2298 */
 521             $header[] = 'Disposition-Notification-To: '.$dnt. $rn;
 522         }
 523         if ($rfc822_header->priority) {
 524             switch($rfc822_header->priority)
 525             {
 526             case 1:
 527                 $header[] = 'X-Priority: 1 (Highest)'.$rn;
 528                 $header[] = 'Importance: High'. $rn; break;
 529             case 5:
 530                 $header[] = 'X-Priority: 5 (Lowest)'.$rn;
 531                 $header[] = 'Importance: Low'. $rn; break;
 532             default: break;
 533             }
 534         }
 535         /* Insert headers from the $more_headers array */
 536         if(count($rfc822_header->more_headers)) {
 537             reset($rfc822_header->more_headers);
 538             foreach ($rfc822_header->more_headers as $k => $v) {
 539                 $header[] = $k.': '.$v .$rn;
 540             }
 541         }
 542         $cnt = count($header);
 543         $hdr_s = '';
 544
 545         for ($i = 0 ; $i < $cnt ; $i++) {
 546             $sKey = substr($header[$i],0,strpos($header[$i],':'));
 547             switch ($sKey)
 548             {
 549             case 'Message-ID':
 550             case 'In-Reply_To':
 551                 $hdr_s .= $header[$i];
 552                 break;
 553             case 'References':
 554                 $sRefs = substr($header[$i],12);
 555                 $aRefs = explode(' ',$sRefs);
 556                 $sLine = 'References:';
 557                 foreach ($aRefs as $sReference) {
 558                     if (strlen($sLine)+strlen($sReference) >76) {
 559                         $hdr_s .= $sLine;
 560                         $sLine = $rn . '    ' . $sReference;
 561                     } else {
 562                         $sLine .= ' '. $sReference;
 563                     }
 564                 }
 565                 $hdr_s .= $sLine;
 566                 break;
 567             case 'To':
 568             case 'Cc':
 569             case 'Bcc':
 570             case 'From':
 571                 $hdr_s .= $header[$i];
 572                 break;
 573             default: $hdr_s .= $this->foldLine($header[$i], 78, str_pad('',4)); break;
 574             }
 575         }
 576         $header = $hdr_s;
 577         $header .= $rn; /* One blank line to separate header and body */
 578         $raw_length += strlen($header);
 579         return $header;
 580     }
 581
 582     /**
 583      * function foldLine - for cleanly folding of headerlines
 584      *
 585      * @param   string  $line
 586      * @param   integer $length length to fold the line at
 587      * @param   string  $pre    prefix the line with...
 588      *
 589      * @return string   $line folded line with trailing CRLF
 590      */
 591     function foldLine($line, $length, $pre='') {
 592         $line = substr($line,0, -2);
 593         $length -= 2; /* do not fold between \r and \n */
 594         $cnt = strlen($line);
 595         if ($cnt > $length) { /* try folding */
 596             $fold_string = "\r\n " . $pre;
 597             $bFirstFold = false;
 598             $aFoldLine = array();
 599             while (strlen($line) > $length) {
 600                 $fold = false;
 601                 /* handle encoded parts */
 602                 if (preg_match('/(=\?([^?]*)\?(Q|B)\?([^?]*)\?=)(\s+|.*)/Ui',$line,$regs)) {
 603                     $fold_tmp = $regs[1];
 604                     if (!trim($regs[5])) {
 605                         $fold_tmp .= $regs[5];
 606                     }
 607                     $iPosEnc = strpos($line,$fold_tmp);
 608                     $iLengthEnc = strlen($fold_tmp);
 609                     $iPosEncEnd = $iPosEnc+$iLengthEnc;
 610                     if ($iPosEnc < $length && (($iPosEncEnd) > $length)) {
 611                         $fold = true;
 612                         /* fold just before the start of the encoded string */
 613                         if ($iPosEnc) {
 614                             $aFoldLine[] = substr($line,0,$iPosEnc);
 615                         }
 616                         $line = substr($line,$iPosEnc);
 617                         if (!$bFirstFold) {
 618                             $bFirstFold = true;
 619                             $length -= strlen($fold_string);
 620                         }
 621                         if ($iLengthEnc > $length) { /* place the encoded
 622                             string on a separate line and do not fold inside it*/
 623                             /* minimize foldstring */
 624                             $fold_string = "\r\n ";
 625                             $aFoldLine[] = substr($line,0,$iLengthEnc);
 626                             $line = substr($line,$iLengthEnc);
 627                         }
 628                     } else if ($iPosEnc < $length) { /* the encoded string fits into the foldlength */
 629                         /*remainder */
 630                         $sLineRem = substr($line,$iPosEncEnd,$length - $iPosEncEnd);
 631                         if (preg_match('/^(=\?([^?]*)\?(Q|B)\?([^?]*)\?=)(.*)/Ui',$sLineRem) || !preg_match('/[=,;\s]/',$sLineRem)) {
 632                             /*impossible to fold clean in the next part -> fold after the enc string */
 633                             $aFoldLine[] = substr($line,0,$iPosEncEnd);
 634                             $line = substr($line,$iPosEncEnd);
 635                             $fold = true;
 636                             if (!$bFirstFold) {
 637                                 $bFirstFold = true;
 638                                 $length -= strlen($fold_string);
 639                             }
 640                         }
 641                     }
 642                 }
 643                 if (!$fold) {
 644                     $line_tmp = substr($line,0,$length);
 645                     $iFoldPos = false;
 646                     /* try to fold at logical places */
 647                     switch (true)
 648                     {
 649                     case ($iFoldPos = strrpos($line_tmp,',')): break;
 650                     case ($iFoldPos = strrpos($line_tmp,';')): break;
 651                     case ($iFoldPos = strrpos($line_tmp,' ')): break;
 652                     case ($iFoldPos = strrpos($line_tmp,'=')): break;
 653                     default: break;
 654                     }
 655
 656                     if (!$iFoldPos) { /* clean folding didn't work */
 657                         $iFoldPos = $length;
 658                     }
 659                     $aFoldLine[] = substr($line,0,$iFoldPos+1);
 660                     $line = substr($line,$iFoldPos+1);
 661                     if (!$bFirstFold) {
 662                         $bFirstFold = true;
 663                         $length -= strlen($fold_string);
 664                     }
 665                 }
 666             }
 667             /*$reconstruct the line */
 668             if ($line) {
 669                 $aFoldLine[] = $line;
 670             }
 671             $line = implode($fold_string,$aFoldLine);
 672         }
 673         return $line."\r\n";
 674     }
 675
 676     /**
 677      * function mimeBoundary - calculates the mime boundary to use
 678      *
 679      * This function will generate a random mime boundary base part
 680      * for the message if the boundary has not already been set.
 681      *
 682      * @return string $mimeBoundaryString random mime boundary string
 683      */
 684     function mimeBoundary () {
 685         static $mimeBoundaryString;
 686
 687         if ( !isset( $mimeBoundaryString ) ||
 688             $mimeBoundaryString == '') {
 689             $mimeBoundaryString = '----=_' . date( 'YmdHis' ) . '_' .
 690             mt_rand( 10000, 99999 );
 691         }
 692         return $mimeBoundaryString;
 693     }
 694
 695     /**
 696      * function timezone - Time offset for correct timezone
 697      *
 698      * @return string $result with timezone and offset
 699      */
 700     function timezone () {
 701         global $invert_time;
 702
 703         $diff_second = date('Z');
 704         if ($invert_time) {
 705             $diff_second = - $diff_second;
 706         }
 707         if ($diff_second > 0) {
 708             $sign = '+';
 709         } else {
 710             $sign = '-';
 711         }
 712         $diff_second = abs($diff_second);
 713         $diff_hour = floor ($diff_second / 3600);
 714         $diff_minute = floor (($diff_second-3600*$diff_hour) / 60);
 715         $zonename = '('.strftime('%Z').')';
 716         $result = sprintf ("%s%02d%02d %s", $sign, $diff_hour, $diff_minute,
 717                        $zonename);
 718         return ($result);
 719     }
 720
 721     /**
 722      * function calculate_references - calculate correct References string
 723      * Adds the current message ID, and makes sure it doesn't grow forever,
 724      * to that extent it drops message-ID's in a smart way until the string
 725      * length is under the recommended value of 1000 ("References: <986>\r\n").
 726      * It always keeps the first and the last three ID's.
 727      *
 728      * @param   Rfc822Header $hdr    message header to calculate from
 729      *
 730      * @return  string       $refer  concatenated and trimmed References string
 731      */
 732     function calculate_references($hdr) {
 733         $aReferences = preg_split('/\s+/', $hdr->references);
 734         $message_id = $hdr->message_id;
 735         $in_reply_to = $hdr->in_reply_to;
 736
 737         // if References already exists, add the current message ID at the end.
 738         // no References exists; if we know a IRT, add that aswell
 739         if (count($aReferences) == 0 && $in_reply_to) {
 740             $aReferences[] = $in_reply_to;
 741         }
 742         $aReferences[] = $message_id;
 743
 744         // sanitize the array: trim whitespace, remove dupes
 745         array_walk($aReferences, 'sq_trim_value');
 746         $aReferences = array_unique($aReferences);
 747
 748         while ( count($aReferences) > 4 && strlen(implode(' ', $aReferences)) >= 986 ) {
 749             $aReferences = array_merge(array_slice($aReferences,0,1),array_slice($aReferences,2));
 750         }
 751         return implode(' ', $aReferences);
 752     }
 753
 754     /**
 755      * Converts ip address to hexadecimal string
 756      *
 757      * Function is used to convert ipv4 and ipv6 addresses to hex strings.
 758      * It removes all delimiter symbols from ip addresses, converts decimal
 759      * ipv4 numbers to hex and pads strings in order to present full length
 760      * address. ipv4 addresses are represented as 8 byte strings, ipv6 addresses
 761      * are represented as 32 byte string.
 762      *
 763      * If function fails to detect address format, it returns unprocessed string.
 764      * @param string $string ip address string
 765      * @return string processed ip address string
 766      * @since 1.5.1 and 1.4.5
 767      */
 768     function ip2hex($string) {
 769         if (preg_match("/^(\d+)\.(\d+)\.(\d+)\.(\d+)$/",$string,$match)) {
 770             // ipv4 address
 771             $ret = str_pad(dechex($match[1]),2,'0',STR_PAD_LEFT)
 772                 . str_pad(dechex($match[2]),2,'0',STR_PAD_LEFT)
 773                 . str_pad(dechex($match[3]),2,'0',STR_PAD_LEFT)
 774                 . str_pad(dechex($match[4]),2,'0',STR_PAD_LEFT);
 775         } elseif (preg_match("/^([0-9a-h]+)\:([0-9a-h]+)\:([0-9a-h]+)\:([0-9a-h]+)\:([0-9a-h]+)\:([0-9a-h]+)\:([0-9a-h]+)\:([0-9a-h]+)$/i",$string,$match)) {
 776             // full ipv6 address
 777             $ret = str_pad($match[1],4,'0',STR_PAD_LEFT)
 778                 . str_pad($match[2],4,'0',STR_PAD_LEFT)
 779                 . str_pad($match[3],4,'0',STR_PAD_LEFT)
 780                 . str_pad($match[4],4,'0',STR_PAD_LEFT)
 781                 . str_pad($match[5],4,'0',STR_PAD_LEFT)
 782                 . str_pad($match[6],4,'0',STR_PAD_LEFT)
 783                 . str_pad($match[7],4,'0',STR_PAD_LEFT)
 784                 . str_pad($match[8],4,'0',STR_PAD_LEFT);
 785         } elseif (preg_match("/^\:\:([0-9a-h\:]+)$/i",$string,$match)) {
 786             // short ipv6 with all starting symbols nulled
 787             $aAddr=explode(':',$match[1]);
 788             $ret='';
 789             foreach ($aAddr as $addr) {
 790                 $ret.=str_pad($addr,4,'0',STR_PAD_LEFT);
 791             }
 792             $ret=str_pad($ret,32,'0',STR_PAD_LEFT);
 793         } elseif (preg_match("/^([0-9a-h\:]+)::([0-9a-h\:]+)$/i",$string,$match)) {
 794             // short ipv6 with middle part nulled
 795             $aStart=explode(':',$match[1]);
 796             $sStart='';
 797             foreach($aStart as $addr) {
 798                 $sStart.=str_pad($addr,4,'0',STR_PAD_LEFT);
 799             }
 800             $aEnd = explode(':',$match[2]);
 801             $sEnd='';
 802             foreach($aEnd as $addr) {
 803                 $sEnd.=str_pad($addr,4,'0',STR_PAD_LEFT);
 804             }
 805             $ret = $sStart
 806                 . str_pad('',(32 - strlen($sStart . $sEnd)),'0',STR_PAD_LEFT)
 807                 . $sEnd;
 808         } else {
 809             // unknown addressing
 810             $ret = $string;
 811         }
 812         return $ret;
 813     }
 814 }