class/deliver/Deliver.class.php

   1 <?php
   2 /**
   3  * Deliver.class.php
   4  *
   5  * Copyright (c) 1999-2005 The SquirrelMail Project Team
   6  * Licensed under the GNU GPL. For full terms see the file COPYING.
   7  *
   8  * This contains all the functions needed to send messages through
   9  * a delivery backend.
  10  *
  11  * @version $Id$
  12  * @author  Marc Groot Koerkamp
  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             $boundary_new = $boundary . '_part_'.$message->entity_id;
  81         } else {
  82             $boundary_new = $boundary;
  83         }
  84         if ($boundary && !$message->rfc822_header) {
  85             $s = '--'.$boundary."\r\n";
  86             $s .= $this->prepareMIME_Header($message, $boundary_new);
  87             $length_raw += strlen($s);
  88             if ($stream) {
  89                 $this->preWriteToStream($s);
  90                 $this->writeToStream($stream, $s);
  91             }
  92         }
  93         $this->writeBodyPart($message, $stream, $length_raw);
  94
  95         $last = false;
  96         for ($i=0, $entCount=count($message->entities);$i<$entCount;$i++) {
  97             $msg = $this->writeBody($message->entities[$i], $stream, $length_raw, $boundary_new);
  98             if ($i == $entCount-1) $last = true;
  99         }
 100         if ($boundary && $last) {
 101             $s = "--".$boundary_new."--\r\n\r\n";
 102             $length_raw += strlen($s);
 103             if ($stream) {
 104                 $this->preWriteToStream($s);
 105                 $this->writeToStream($stream, $s);
 106             }
 107         }
 108     }
 109
 110     /**
 111      * function writeBodyPart - write each individual mimepart
 112      *
 113      * Recursively called by WriteBody to write each mime part to the SMTP stream
 114      *
 115      * @param Message   $message      Message object to transform
 116      * @param resource  $stream       SMTP output stream
 117      * @param integer  &$length       length of the message part
 118      *                                as returned by mail fn
 119      *
 120      * @return void
 121      */
 122     function writeBodyPart($message, $stream, &$length) {
 123         if ($message->mime_header) {
 124             $type0 = $message->mime_header->type0;
 125         } else {
 126             $type0 = $message->rfc822_header->content_type->type0;
 127         }
 128
 129         $body_part_trailing = $last = '';
 130         switch ($type0)
 131         {
 132         case 'text':
 133         case 'message':
 134             if ($message->body_part) {
 135                 $body_part = $message->body_part;
 136                 $length += $this->clean_crlf($body_part);
 137                 if ($stream) {
 138                     $this->preWriteToStream($body_part);
 139                     $this->writeToStream($stream, $body_part);
 140                 }
 141                 $last = $body_part;
 142             } elseif ($message->att_local_name) {
 143                 $filename = $message->att_local_name;
 144                 $file = fopen ($filename, 'rb');
 145                 while ($body_part = fgets($file, 4096)) {
 146                     $length += $this->clean_crlf($body_part);
 147                     if ($stream) {
 148                         $this->preWriteToStream($body_part);
 149                         $this->writeToStream($stream, $body_part);
 150                     }
 151                     $last = $body_part;
 152                 }
 153                 fclose($file);
 154             }
 155             break;
 156         default:
 157             if ($message->body_part) {
 158                 $body_part = $message->body_part;
 159                 $length += $this->clean_crlf($body_part);
 160                 if ($stream) {
 161                     $this->writeToStream($stream, $body_part);
 162                 }
 163             } elseif ($message->att_local_name) {
 164                 $filename = $message->att_local_name;
 165                 $file = fopen ($filename, 'rb');
 166                 while ($tmp = fread($file, 570)) {
 167                    $body_part = chunk_split(base64_encode($tmp));
 168                     $length += $this->clean_crlf($body_part);
 169                     if ($stream) {
 170                         $this->writeToStream($stream, $body_part);
 171                     }
 172                 }
 173                 fclose($file);
 174             }
 175             break;
 176         }
 177         $body_part_trailing = '';
 178         if ($last && substr($last,-1) != "\n") {
 179             $body_part_trailing = "\r\n";
 180         }
 181         if ($body_part_trailing) {
 182             $length += strlen($body_part_trailing);
 183             if ($stream) {
 184                 $this->preWriteToStream($body_part_trailing);
 185                 $this->writeToStream($stream, $body_part_trailing);
 186             }
 187         }
 188     }
 189
 190     /**
 191      * function clean_crlf - change linefeeds and newlines to legal characters
 192      *
 193      * The SMTP format only allows CRLF as line terminators.
 194      * This function replaces illegal teminators with the correct terminator.
 195      *
 196      * @param string &$s string to clean linefeeds on
 197      *
 198      * @return void
 199      */
 200     function clean_crlf(&$s) {
 201         $s = str_replace("\r\n", "\n", $s);
 202         $s = str_replace("\r", "\n", $s);
 203         $s = str_replace("\n", "\r\n", $s);
 204         return strlen($s);
 205     }
 206
 207     /**
 208      * function strip_crlf - strip linefeeds and newlines from a string
 209      *
 210      * The SMTP format only allows CRLF as line terminators.
 211      * This function strips all line terminators from the string.
 212      *
 213      * @param string &$s string to clean linefeeds on
 214      *
 215      * @return void
 216      */
 217     function strip_crlf(&$s) {
 218         $s = str_replace("\r\n ", '', $s);
 219         $s = str_replace("\r", '', $s);
 220         $s = str_replace("\n", '', $s);
 221     }
 222
 223     /**
 224      * function preWriteToStream - reserved for extended functionality
 225      *
 226      * This function is not yet implemented.
 227      * Reserved for extended functionality.
 228      *
 229      * @param string &$s string to operate on
 230      *
 231      * @return void
 232      */
 233     function preWriteToStream(&$s) {
 234     }
 235
 236     /**
 237      * function writeToStream - write data to the SMTP stream
 238      *
 239      * @param resource $stream  SMTP output stream
 240      * @param string   $data    string with data to send to the SMTP stream
 241      *
 242      * @return void
 243      */
 244     function writeToStream($stream, $data) {
 245         fputs($stream, $data);
 246     }
 247
 248     /**
 249      * function initStream - reserved for extended functionality
 250      *
 251      * This function is not yet implemented.
 252      * Reserved for extended functionality.
 253      *
 254      * @param Message $message  Message object
 255      * @param string  $host     host name or IP to connect to
 256      * @param string  $user     username to log into the SMTP server with
 257      * @param string  $pass     password to log into the SMTP server with
 258      * @param integer $length
 259      *
 260      * @return handle $stream file handle resource to SMTP stream
 261      */
 262     function initStream($message, $length=0, $host='', $port='', $user='', $pass='') {
 263         return $stream;
 264     }
 265
 266     /**
 267      * function getBCC - reserved for extended functionality
 268      *
 269      * This function is not yet implemented.
 270      * Reserved for extended functionality.
 271      *
 272      */
 273     function getBCC() {
 274         return false;
 275     }
 276
 277     /**
 278      * function prepareMIME_Header - creates the mime header
 279      *
 280      * @param Message $message  Message object to act on
 281      * @param string  $boundary mime boundary from fn MimeBoundary
 282      *
 283      * @return string $header properly formatted mime header
 284      */
 285     function prepareMIME_Header($message, $boundary) {
 286         $mime_header = $message->mime_header;
 287         $rn="\r\n";
 288         $header = array();
 289
 290         $contenttype = 'Content-Type: '. $mime_header->type0 .'/'.
 291                         $mime_header->type1;
 292         if (count($message->entities)) {
 293             $contenttype .= ";\r\n " . 'boundary="'.$boundary.'"';
 294         }
 295         if (isset($mime_header->parameters['name'])) {
 296             $contenttype .= '; name="'.
 297             encodeHeader($mime_header->parameters['name']). '"';
 298         }
 299         if (isset($mime_header->parameters['charset'])) {
 300             $charset = $mime_header->parameters['charset'];
 301             $contenttype .= '; charset="'.
 302             encodeHeader($charset). '"';
 303         }
 304
 305         $header[] = $contenttype . $rn;
 306         if ($mime_header->description) {
 307             $header[] .= 'Content-Description: ' . $mime_header->description . $rn;
 308         }
 309         if ($mime_header->encoding) {
 310             $header[] .= 'Content-Transfer-Encoding: ' . $mime_header->encoding . $rn;
 311         } else {
 312             if ($mime_header->type0 == 'text' || $mime_header->type0 == 'message') {
 313                 $header[] .= 'Content-Transfer-Encoding: 8bit' .  $rn;
 314             } else {
 315                 $header[] .= 'Content-Transfer-Encoding: base64' .  $rn;
 316             }
 317         }
 318         if ($mime_header->id) {
 319             $header[] .= 'Content-ID: ' . $mime_header->id . $rn;
 320         }
 321         if ($mime_header->disposition) {
 322             $disposition = $mime_header->disposition;
 323             $contentdisp = 'Content-Disposition: ' . $disposition->name;
 324             if ($disposition->getProperty('filename')) {
 325                 $contentdisp .= '; filename="'.
 326                 encodeHeader($disposition->getProperty('filename')). '"';
 327             }
 328             $header[] = $contentdisp . $rn;
 329         }
 330         if ($mime_header->md5) {
 331             $header[] .= 'Content-MD5: ' . $mime_header->md5 . $rn;
 332         }
 333         if ($mime_header->language) {
 334             $header[] .= 'Content-Language: ' . $mime_header->language . $rn;
 335         }
 336
 337         $cnt = count($header);
 338         $hdr_s = '';
 339         for ($i = 0 ; $i < $cnt ; $i++)    {
 340             $hdr_s .= $this->foldLine($header[$i], 78,str_pad('',4));
 341         }
 342         $header = $hdr_s;
 343         $header .= $rn; /* One blank line to separate mimeheader and body-entity */
 344         return $header;
 345     }
 346
 347     /**
 348      * function prepareRFC822_Header - prepares the RFC822 header string from Rfc822Header object(s)
 349      *
 350      * This function takes the Rfc822Header object(s) and formats them
 351      * into the RFC822Header string to send to the SMTP server as part
 352      * of the SMTP message.
 353      *
 354      * @param Rfc822Header  $rfc822_header
 355      * @param Rfc822Header  $reply_rfc822_header
 356      * @param integer      &$raw_length length of the message
 357      *
 358      * @return string $header
 359      */
 360     function prepareRFC822_Header($rfc822_header, $reply_rfc822_header, &$raw_length) {
 361         global $domain, $version, $username, $skip_SM_header;
 362
 363         /* if server var SERVER_NAME not available, use $domain */
 364         if(!sqGetGlobalVar('SERVER_NAME', $SERVER_NAME, SQ_SERVER)) {
 365             $SERVER_NAME = $domain;
 366         }
 367
 368         sqGetGlobalVar('REMOTE_ADDR', $REMOTE_ADDR, SQ_SERVER);
 369         sqGetGlobalVar('REMOTE_PORT', $REMOTE_PORT, SQ_SERVER);
 370         sqGetGlobalVar('REMOTE_HOST', $REMOTE_HOST, SQ_SERVER);
 371         sqGetGlobalVar('HTTP_VIA',    $HTTP_VIA,    SQ_SERVER);
 372         sqGetGlobalVar('HTTP_X_FORWARDED_FOR', $HTTP_X_FORWARDED_FOR, SQ_SERVER);
 373
 374         $rn = "\r\n";
 375
 376         /* This creates an RFC 822 date */
 377         $date = date('D, j M Y H:i:s ', mktime()) . $this->timezone();
 378         /* Create a message-id */
 379         $message_id = '<' . $REMOTE_PORT . '.' . $REMOTE_ADDR . '.';
 380         $message_id .= time() . '.squirrel@' . $SERVER_NAME .'>';
 381         /* Make an RFC822 Received: line */
 382         if (isset($REMOTE_HOST)) {
 383             $received_from = "$REMOTE_HOST ([$REMOTE_ADDR])";
 384         } else {
 385             $received_from = $REMOTE_ADDR;
 386         }
 387         if (isset($HTTP_VIA) || isset ($HTTP_X_FORWARDED_FOR)) {
 388             if (!isset($HTTP_X_FORWARDED_FOR) || $HTTP_X_FORWARDED_FOR == '') {
 389                 $HTTP_X_FORWARDED_FOR = 'unknown';
 390             }
 391             $received_from .= " (proxying for $HTTP_X_FORWARDED_FOR)";
 392         }
 393         $header = array();
 394         if ( !isset($skip_SM_header) || !$skip_SM_header )
 395         {
 396           $header[] = "Received: from $received_from" . $rn;
 397           $header[] = "        (SquirrelMail authenticated user $username)" . $rn;
 398           $header[] = "        by $SERVER_NAME with HTTP;" . $rn;
 399           $header[] = "        $date" . $rn;
 400         }
 401         /* Insert the rest of the header fields */
 402         $header[] = 'Message-ID: '. $message_id . $rn;
 403         if ($reply_rfc822_header->message_id) {
 404             $rep_message_id = $reply_rfc822_header->message_id;
 405         //        $this->strip_crlf($message_id);
 406             $header[] = 'In-Reply-To: '.$rep_message_id . $rn;
 407             $references = $this->calculate_references($reply_rfc822_header);
 408             $header[] = 'References: '.$references . $rn;
 409         }
 410         $header[] = "Date: $date" . $rn;
 411         $header[] = 'Subject: '.encodeHeader($rfc822_header->subject) . $rn;
 412         $header[] = 'From: '. $rfc822_header->getAddr_s('from',",$rn ",true) . $rn;
 413
 414         // folding address list [From|To|Cc|Bcc] happens by using ",$rn<space>" as delimiter
 415         // Do not use foldLine for that.
 416
 417         // RFC2822 if from contains more then 1 address
 418         if (count($rfc822_header->from) > 1) {
 419             $header[] = 'Sender: '. $rfc822_header->getAddr_s('sender',',',true) . $rn;
 420         }
 421         if (count($rfc822_header->to)) {
 422             $header[] = 'To: '. $rfc822_header->getAddr_s('to',",$rn ",true) . $rn;
 423         }
 424         if (count($rfc822_header->cc)) {
 425             $header[] = 'Cc: '. $rfc822_header->getAddr_s('cc',",$rn ",true) . $rn;
 426         }
 427         if (count($rfc822_header->reply_to)) {
 428             $header[] = 'Reply-To: '. $rfc822_header->getAddr_s('reply_to',',',true) . $rn;
 429         }
 430         /* Sendmail should return true. Default = false */
 431         $bcc = $this->getBcc();
 432         if (count($rfc822_header->bcc)) {
 433             $s = 'Bcc: '. $rfc822_header->getAddr_s('bcc',",$rn ",true) . $rn;
 434             if (!$bcc) {
 435                 $raw_length += strlen($s);
 436             } else {
 437                 $header[] = $s;
 438             }
 439         }
 440         /* Identify SquirrelMail */
 441         $header[] = 'User-Agent: SquirrelMail/' . $version . $rn;
 442         /* Do the MIME-stuff */
 443         $header[] = 'MIME-Version: 1.0' . $rn;
 444         $contenttype = 'Content-Type: '. $rfc822_header->content_type->type0 .'/'.
 445                                          $rfc822_header->content_type->type1;
 446         if (count($rfc822_header->content_type->properties)) {
 447             foreach ($rfc822_header->content_type->properties as $k => $v) {
 448                 if ($k && $v) {
 449                     $contenttype .= ';' .$k.'='.$v;
 450                 }
 451             }
 452         }
 453         $header[] = $contenttype . $rn;
 454         if ($encoding = $rfc822_header->encoding) {
 455             $header[] .= 'Content-Transfer-Encoding: ' . $encoding .  $rn;
 456         }
 457         if ($rfc822_header->dnt) {
 458             $dnt = $rfc822_header->getAddr_s('dnt');
 459             /* Pegasus Mail */
 460             $header[] = 'X-Confirm-Reading-To: '.$dnt. $rn;
 461             /* RFC 2298 */
 462             $header[] = 'Disposition-Notification-To: '.$dnt. $rn;
 463         }
 464         if ($rfc822_header->priority) {
 465             switch($rfc822_header->priority)
 466             {
 467             case 1:
 468                 $header[] = 'X-Priority: 1 (Highest)'.$rn;
 469                 $header[] = 'Importance: High'. $rn; break;
 470             case 3:
 471                 $header[] = 'X-Priority: 3 (Normal)'.$rn;
 472                 $header[] = 'Importance: Normal'. $rn; break;
 473             case 5:
 474                 $header[] = 'X-Priority: 5 (Lowest)'.$rn;
 475                 $header[] = 'Importance: Low'. $rn; break;
 476             default: break;
 477             }
 478         }
 479         /* Insert headers from the $more_headers array */
 480         if(count($rfc822_header->more_headers)) {
 481             reset($rfc822_header->more_headers);
 482             foreach ($rfc822_header->more_headers as $k => $v) {
 483                 $header[] = $k.': '.$v .$rn;
 484             }
 485         }
 486         $cnt = count($header);
 487         $hdr_s = '';
 488
 489         for ($i = 0 ; $i < $cnt ; $i++) {
 490             $sKey = substr($header[$i],0,strpos($header[$i],':'));
 491             switch ($sKey)
 492             {
 493             case 'Message-ID':
 494             case 'In-Reply_To':
 495                 $hdr_s .= $header[$i];
 496                 break;
 497             case 'References':
 498                 $sRefs = substr($header[$i],12);
 499                 $aRefs = explode(' ',$sRefs);
 500                 $sLine = 'References:';
 501                 foreach ($aRefs as $sReference) {
 502                     if (strlen($sLine)+strlen($sReference) >76) {
 503                         $hdr_s .= $sLine;
 504                         $sLine = $rn . '    ' . $sReference;
 505                     } else {
 506                         $sLine .= ' '. $sReference;
 507                     }
 508                 }
 509                 $hdr_s .= $sLine;
 510                 break;
 511             case 'To':
 512             case 'Cc':
 513             case 'Bcc':
 514             case 'From':
 515                 $hdr_s .= $header[$i];
 516                 break;
 517             default: $hdr_s .= $this->foldLine($header[$i], 78, str_pad('',4)); break;
 518             }
 519         }
 520         $header = $hdr_s;
 521         $header .= $rn; /* One blank line to separate header and body */
 522         $raw_length += strlen($header);
 523         return $header;
 524     }
 525
 526     /**
 527      * function foldLine - for cleanly folding of headerlines
 528      *
 529      * @param   string  $line
 530      * @param   integer $length length to fold the line at
 531      * @param   string  $pre    prefix the line with...
 532      *
 533      * @return string   $line folded line with trailing CRLF
 534      */
 535     function foldLine($line, $length, $pre='') {
 536         $line = substr($line,0, -2);
 537         $length -= 2; /* do not fold between \r and \n */
 538         $cnt = strlen($line);
 539         if ($cnt > $length) { /* try folding */
 540             $fold_string = "\r\n " . $pre;
 541             $bFirstFold = false;
 542             $aFoldLine = array();
 543             while (strlen($line) > $length) {
 544                 $fold = false;
 545                 /* handle encoded parts */
 546                 if (preg_match('/(=\?([^?]*)\?(Q|B)\?([^?]*)\?=)(\s+|.*)/Ui',$line,$regs)) {
 547                     $fold_tmp = $regs[1];
 548                     if (!trim($regs[5])) {
 549                         $fold_tmp .= $regs[5];
 550                     }
 551                     $iPosEnc = strpos($line,$fold_tmp);
 552                     $iLengthEnc = strlen($fold_tmp);
 553                     $iPosEncEnd = $iPosEnc+$iLengthEnc;
 554                     if ($iPosEnc < $length && (($iPosEncEnd) > $length)) {
 555                         $fold = true;
 556                         /* fold just before the start of the encoded string */
 557                         if ($iPosEnc) {
 558                             $aFoldLine[] = substr($line,0,$iPosEnc);
 559                         }
 560                         $line = substr($line,$iPosEnc);
 561                         if (!$bFirstFold) {
 562                             $bFirstFold = true;
 563                             $length -= strlen($fold_string);
 564                         }
 565                         if ($iLengthEnc > $length) { /* place the encoded
 566                             string on a separate line and do not fold inside it*/
 567                             /* minimize foldstring */
 568                             $fold_string = "\r\n ";
 569                             $aFoldLine[] = substr($line,0,$iLengthEnc);
 570                             $line = substr($line,$iLengthEnc);
 571                         }
 572                     } else if ($iPosEnc < $length) { /* the encoded string fits into the foldlength */
 573                         /*remainder */
 574                         $sLineRem = substr($line,$iPosEncEnd,$length - $iPosEncEnd);
 575                         if (preg_match('/^(=\?([^?]*)\?(Q|B)\?([^?]*)\?=)(.*)/Ui',$sLineRem) || !preg_match('/[=,;\s]/',$sLineRem)) {
 576                             /*impossible to fold clean in the next part -> fold after the enc string */
 577                             $aFoldLine[] = substr($line,0,$iPosEncEnd);
 578                             $line = substr($line,$iPosEncEnd);
 579                             $fold = true;
 580                             if (!$bFirstFold) {
 581                                 $bFirstFold = true;
 582                                 $length -= strlen($fold_string);
 583                             }
 584                         }
 585                     }
 586                 }
 587                 if (!$fold) {
 588                     $line_tmp = substr($line,0,$length);
 589                     $iFoldPos = false;
 590                     /* try to fold at logical places */
 591                     switch (true)
 592                     {
 593                     case ($iFoldPos = strrpos($line_tmp,',')): break;
 594                     case ($iFoldPos = strrpos($line_tmp,';')): break;
 595                     case ($iFoldPos = strrpos($line_tmp,' ')): break;
 596                     case ($iFoldPos = strrpos($line_tmp,'=')): break;
 597                     default: break;
 598                     }
 599
 600                     if (!$iFoldPos) { /* clean folding didn't work */
 601                         $iFoldPos = $length;
 602                     }
 603                     $aFoldLine[] = substr($line,0,$iFoldPos+1);
 604                     $line = substr($line,$iFoldPos+1);
 605                     if (!$bFirstFold) {
 606                         $bFirstFold = true;
 607                         $length -= strlen($fold_string);
 608                     }
 609                 }
 610             }
 611             /*$reconstruct the line */
 612             if ($line) {
 613                 $aFoldLine[] = $line;
 614             }
 615             $line = implode($fold_string,$aFoldLine);
 616         }
 617         return $line."\r\n";
 618     }
 619
 620     /**
 621      * function mimeBoundary - calculates the mime boundary to use
 622      *
 623      * This function will generate a random mime boundary base part
 624      * for the message if the boundary has not already been set.
 625      *
 626      * @return string $mimeBoundaryString random mime boundary string
 627      */
 628     function mimeBoundary () {
 629         static $mimeBoundaryString;
 630
 631         if ( !isset( $mimeBoundaryString ) ||
 632             $mimeBoundaryString == '') {
 633             $mimeBoundaryString = '----=_' . date( 'YmdHis' ) . '_' .
 634             mt_rand( 10000, 99999 );
 635         }
 636         return $mimeBoundaryString;
 637     }
 638
 639     /**
 640      * function timezone - Time offset for correct timezone
 641      *
 642      * @return string $result with timezone and offset
 643      */
 644     function timezone () {
 645         global $invert_time;
 646
 647         $diff_second = date('Z');
 648         if ($invert_time) {
 649             $diff_second = - $diff_second;
 650         }
 651         if ($diff_second > 0) {
 652             $sign = '+';
 653         } else {
 654             $sign = '-';
 655         }
 656         $diff_second = abs($diff_second);
 657         $diff_hour = floor ($diff_second / 3600);
 658         $diff_minute = floor (($diff_second-3600*$diff_hour) / 60);
 659         $zonename = '('.strftime('%Z').')';
 660         $result = sprintf ("%s%02d%02d %s", $sign, $diff_hour, $diff_minute,
 661                        $zonename);
 662         return ($result);
 663     }
 664
 665     /**
 666      * function calculate_references - calculate correct Referer string
 667      *
 668      * @param   Rfc822Header $hdr    message header to calculate from
 669      *
 670      * @return  string       $refer  concatenated and trimmed Referer string
 671      */
 672     function calculate_references($hdr) {
 673         $refer = $hdr->references;
 674         $message_id = $hdr->message_id;
 675         $in_reply_to = $hdr->in_reply_to;
 676         if (strlen($refer) > 2) {
 677             $refer .= ' ' . $message_id;
 678         } else {
 679             if ($in_reply_to) {
 680                 $refer .= $in_reply_to . ' ' . $message_id;
 681             } else {
 682                 $refer .= $message_id;
 683             }
 684         }
 685         trim($refer);
 686         return $refer;
 687     }
 688 }
 689 ?>