replacing skip_SM_header with two different options. If admins want to shoot
[squirrelmail.git] / class / deliver / Deliver.class.php
index 8b9ae88ee4e646bf7c19845c836b99945d951227..9cf091aaa832f162d9275760679f1333717da648 100644 (file)
 <?php
-
 /**
  * Deliver.class.php
  *
- * Copyright (c) 1999-2003 The SquirrelMail Project Team
+ * Copyright (c) 1999-2005 The SquirrelMail Project Team
  * Licensed under the GNU GPL. For full terms see the file COPYING.
  *
  * This contains all the functions needed to send messages through
  * a delivery backend.
  *
- * $Id$
+ * @version $Id$
+ * @author  Marc Groot Koerkamp
+ * @package squirrelmail
  */
 
+/**
+ * Deliver Class - called to actually deliver the message
+ *
+ * This class is called by compose.php and other code that needs
+ * to send messages.  All delivery functionality should be centralized
+ * in this class.
+ *
+ * Do not place UI code in this class, as UI code should be placed in templates
+ * going forward.
+ *
+ * @author  Marc Groot Koerkamp
+ * @package squirrelmail
+ */
 class Deliver {
 
+    /**
+     * function mail - send the message parts to the SMTP stream
+     *
+     * @param Message  $message  Message class to send
+     * @param resource $stream   file handle to the SMTP stream
+     *
+     * @return integer $raw_length
+     */
     function mail($message, $stream=false) {
-       $rfc822_header = $message->rfc822_header;
-       if (count($message->entities)) {
-          $boundary = $this->mimeBoundary();
-         $rfc822_header->content_type->properties['boundary']='"'.$boundary.'"';
-       } else {
-          $boundary='';
-       }
-       $raw_length = 0;
-       $reply_rfc822_header = (isset($message->reply_rfc822_header) 
-                            ? $message->reply_rfc822_header : '');
-       $header = $this->prepareRFC822_Header($rfc822_header, $reply_rfc822_header, $raw_length);
-
-       if ($stream) {
+        $rfc822_header = $message->rfc822_header;
+        if (count($message->entities)) {
+            $boundary = $this->mimeBoundary();
+            $rfc822_header->content_type->properties['boundary']='"'.$boundary.'"';
+        } else {
+            $boundary='';
+        }
+        $raw_length = 0;
+        $reply_rfc822_header = (isset($message->reply_rfc822_header)
+                             ? $message->reply_rfc822_header : '');
+        $header = $this->prepareRFC822_Header($rfc822_header, $reply_rfc822_header, $raw_length);
+
+        if ($stream) {
             $this->preWriteToStream($header);
             $this->writeToStream($stream, $header);
-       }
-       $this->writeBody($message, $stream, $raw_length, $boundary);
-       return $raw_length;
+        }
+        $this->writeBody($message, $stream, $raw_length, $boundary);
+        return $raw_length;
     }
-    
+
+    /**
+     * function writeBody - generate and write the mime boundaries around each part to the stream
+     *
+     * Recursively formats and writes the MIME boundaries of the $message
+     * to the output stream.
+     *
+     * @param Message   $message      Message object to transform
+     * @param resource  $stream       SMTP output stream
+     * @param integer  &$length_raw   raw length of the message (part)
+     *                                as returned by mail fn
+     * @param string    $boundary     custom boundary to call, usually for subparts
+     *
+     * @return void
+     */
     function writeBody($message, $stream, &$length_raw, $boundary='') {
+        // calculate boundary in case of multidimensional mime structures
+        if ($boundary && $message->entity_id && count($message->entities)) {
+            if (strpos($boundary,'_part_')) {
+                $boundary = substr($boundary,0,strpos($boundary,'_part_'));
+
+            // the next four lines use strrev to reverse any nested boundaries
+            // because RFC 2046 (5.1.1) says that if a line starts with the outer
+            // boundary string (doesn't matter what the line ends with), that
+            // can be considered a match for the outer boundary; thus the nested
+            // boundary needs to be unique from the outer one
+            //
+            } else if (strpos($boundary,'_trap_')) {
+                $boundary = substr(strrev($boundary),0,strpos(strrev($boundary),'_part_'));
+            }
+            $boundary_new = strrev($boundary . '_part_'.$message->entity_id);
+        } else {
+            $boundary_new = $boundary;
+        }
         if ($boundary && !$message->rfc822_header) {
-           $s = '--'.$boundary."\r\n";
-           $s .= $this->prepareMIME_Header($message, $boundary);
-           $length_raw += strlen($s);
-           if ($stream) {
+            $s = '--'.$boundary."\r\n";
+            $s .= $this->prepareMIME_Header($message, $boundary_new);
+            $length_raw += strlen($s);
+            if ($stream) {
                 $this->preWriteToStream($s);
-               $this->writeToStream($stream, $s);
-           }
-        }
-       $this->writeBodyPart($message, $stream, $length_raw);
-       $boundary_depth = substr_count($message->entity_id,'.');
-       if ($boundary_depth) {
-          $boundary .= '_part'.$boundary_depth;
-       }
-       $last = false;
-       for ($i=0, $entCount=count($message->entities);$i<$entCount;$i++) {
-           $msg = $this->writeBody($message->entities[$i], $stream, $length_raw, $boundary);
-           if ($i == $entCount-1) $last = true;
-       }
+                $this->writeToStream($stream, $s);
+            }
+        }
+        $this->writeBodyPart($message, $stream, $length_raw);
+
+        $last = false;
+        for ($i=0, $entCount=count($message->entities);$i<$entCount;$i++) {
+            $msg = $this->writeBody($message->entities[$i], $stream, $length_raw, $boundary_new);
+            if ($i == $entCount-1) $last = true;
+        }
         if ($boundary && $last) {
-           $s = "--".$boundary."--\r\n\r\n";
-           $length_raw += strlen($s);
-           if ($stream) {
+            $s = "--".$boundary_new."--\r\n\r\n";
+            $length_raw += strlen($s);
+            if ($stream) {
                 $this->preWriteToStream($s);
-               $this->writeToStream($stream, $s);
-           }
-       }
+                $this->writeToStream($stream, $s);
+            }
+        }
     }
 
+    /**
+     * function writeBodyPart - write each individual mimepart
+     *
+     * Recursively called by WriteBody to write each mime part to the SMTP stream
+     *
+     * @param Message   $message      Message object to transform
+     * @param resource  $stream       SMTP output stream
+     * @param integer  &$length       length of the message part
+     *                                as returned by mail fn
+     *
+     * @return void
+     */
     function writeBodyPart($message, $stream, &$length) {
         if ($message->mime_header) {
-          $type0 = $message->mime_header->type0;
-       } else {
-          $type0 = $message->rfc822_header->content_type->type0;
-       }
-       
-       $body_part_trailing = $last = '';
-       switch ($type0) {
-       case 'text':
-       case 'message':
-           if ($message->body_part) {
-              $body_part = $message->body_part;
-              $length += $this->clean_crlf($body_part);
-              if ($stream) {
-                  $this->preWriteToStream($body_part);     
-                 $this->writeToStream($stream, $body_part);
-              }
-              $last = $body_part;
-           } elseif ($message->att_local_name) {
-               $filename = $message->att_local_name;
-               $file = fopen ($filename, 'rb');
-               while ($body_part = fgets($file, 4096)) {
-                  $length += $this->clean_crlf($body_part);
-                  if ($stream) {
-                     $this->preWriteToStream($body_part);
-                     $this->writeToStream($stream, $body_part);
-                   }
-                  $last = $body_part;
-               }
-               fclose($file);
+            $type0 = $message->mime_header->type0;
+        } else {
+            $type0 = $message->rfc822_header->content_type->type0;
+        }
+
+        $body_part_trailing = $last = '';
+        switch ($type0)
+        {
+        case 'text':
+        case 'message':
+            if ($message->body_part) {
+                $body_part = $message->body_part;
+                // remove NUL characters
+                $body_part = str_replace("\0",'',$body_part);
+                $length += $this->clean_crlf($body_part);
+                if ($stream) {
+                    $this->preWriteToStream($body_part);
+                    $this->writeToStream($stream, $body_part);
+                }
+                $last = $body_part;
+            } elseif ($message->att_local_name) {
+                $filename = $message->att_local_name;
+                $file = fopen ($filename, 'rb');
+                while ($body_part = fgets($file, 4096)) {
+                    // remove NUL characters
+                    $body_part = str_replace("\0",'',$body_part);
+                    $length += $this->clean_crlf($body_part);
+                    if ($stream) {
+                        $this->preWriteToStream($body_part);
+                        $this->writeToStream($stream, $body_part);
+                    }
+                    $last = $body_part;
+                }
+                fclose($file);
             }
-           break;
-       default:
-           if ($message->body_part) {
-              $body_part = $message->body_part;
-              $length += $this->clean_crlf($body_part);
-              if ($stream) {
-                 $this->writeToStream($stream, $body_part);
-              }
-           } elseif ($message->att_local_name) {
-               $filename = $message->att_local_name;
-               $file = fopen ($filename, 'rb');
-               $encoded = '';
-               while ($tmp = fread($file, 570)) {
-                  $body_part = chunk_split(base64_encode($tmp));
-                  $length += $this->clean_crlf($body_part);
-                  if ($stream) {
-                     $this->writeToStream($stream, $body_part);
-                  }
-               }
-               fclose($file);
-           }
-           break;
-       }
-       $body_part_trailing = '';
-       if ($last && substr($last,-1) != "\n") {
-          $body_part_trailing = "\r\n";
-       }
-       if ($body_part_trailing) {
-           $length += strlen($body_part_trailing);
-           if ($stream) {
-               $this->preWriteToStream($body_part_trailing);     
-               $this->writeToStream($stream, $body_part_trailing);
-           }
-       }
+            break;
+        default:
+            if ($message->body_part) {
+                $body_part = $message->body_part;
+                // remove NUL characters
+                $body_part = str_replace("\0",'',$body_part);
+                $length += $this->clean_crlf($body_part);
+                if ($stream) {
+                    $this->writeToStream($stream, $body_part);
+                }
+            } elseif ($message->att_local_name) {
+                $filename = $message->att_local_name;
+                $file = fopen ($filename, 'rb');
+                while ($tmp = fread($file, 570)) {
+                   $body_part = chunk_split(base64_encode($tmp));
+                    $length += $this->clean_crlf($body_part);
+                    if ($stream) {
+                        $this->writeToStream($stream, $body_part);
+                    }
+                }
+                fclose($file);
+            }
+            break;
+        }
+        $body_part_trailing = '';
+        if ($last && substr($last,-1) != "\n") {
+            $body_part_trailing = "\r\n";
+        }
+        if ($body_part_trailing) {
+            $length += strlen($body_part_trailing);
+            if ($stream) {
+                $this->preWriteToStream($body_part_trailing);
+                $this->writeToStream($stream, $body_part_trailing);
+            }
+        }
     }
-    
+
+    /**
+     * function clean_crlf - change linefeeds and newlines to legal characters
+     *
+     * The SMTP format only allows CRLF as line terminators.
+     * This function replaces illegal teminators with the correct terminator.
+     *
+     * @param string &$s string to clean linefeeds on
+     *
+     * @return void
+     */
     function clean_crlf(&$s) {
         $s = str_replace("\r\n", "\n", $s);
         $s = str_replace("\r", "\n", $s);
         $s = str_replace("\n", "\r\n", $s);
-       return strlen($s);
+        return strlen($s);
     }
-    
+
+    /**
+     * function strip_crlf - strip linefeeds and newlines from a string
+     *
+     * The SMTP format only allows CRLF as line terminators.
+     * This function strips all line terminators from the string.
+     *
+     * @param string &$s string to clean linefeeds on
+     *
+     * @return void
+     */
     function strip_crlf(&$s) {
         $s = str_replace("\r\n ", '', $s);
-       $s = str_replace("\r", '', $s);
-       $s = str_replace("\n", '', $s);
+        $s = str_replace("\r", '', $s);
+        $s = str_replace("\n", '', $s);
     }
 
+    /**
+     * function preWriteToStream - reserved for extended functionality
+     *
+     * This function is not yet implemented.
+     * Reserved for extended functionality.
+     *
+     * @param string &$s string to operate on
+     *
+     * @return void
+     */
     function preWriteToStream(&$s) {
     }
-    
+
+    /**
+     * function writeToStream - write data to the SMTP stream
+     *
+     * @param resource $stream  SMTP output stream
+     * @param string   $data    string with data to send to the SMTP stream
+     *
+     * @return void
+     */
     function writeToStream($stream, $data) {
-       fputs($stream, $data);
+        fputs($stream, $data);
     }
-    
+
+    /**
+     * function initStream - reserved for extended functionality
+     *
+     * This function is not yet implemented.
+     * Reserved for extended functionality.
+     *
+     * @param Message $message  Message object
+     * @param string  $host     host name or IP to connect to
+     * @param string  $user     username to log into the SMTP server with
+     * @param string  $pass     password to log into the SMTP server with
+     * @param integer $length
+     *
+     * @return handle $stream file handle resource to SMTP stream
+     */
     function initStream($message, $length=0, $host='', $port='', $user='', $pass='') {
-       return $stream;
+        return $stream;
     }
-    
-    function getBcc() {
-       return false;
+
+    /**
+     * function getBCC - reserved for extended functionality
+     *
+     * This function is not yet implemented.
+     * Reserved for extended functionality.
+     *
+     */
+    function getBCC() {
+        return false;
     }
 
+    /**
+     * function prepareMIME_Header - creates the mime header
+     *
+     * @param Message $message  Message object to act on
+     * @param string  $boundary mime boundary from fn MimeBoundary
+     *
+     * @return string $header properly formatted mime header
+     */
     function prepareMIME_Header($message, $boundary) {
-       $mime_header = $message->mime_header;
-       $rn="\r\n";
-       $header = array();
-       
-       $contenttype = 'Content-Type: '. $mime_header->type0 .'/'.
-                      $mime_header->type1;
-       if (count($message->entities)) {
-           $contenttype .= ";\r\n " . 'boundary="'.$boundary.'"';
-       }                      
-       if (isset($mime_header->parameters['name'])) {
-           $contenttype .= '; name="'.
-               encodeHeader($mime_header->parameters['name']). '"';
-       }
-       if (isset($mime_header->parameters['charset'])) {
-           $charset = $mime_header->parameters['charset'];
-           $contenttype .= '; charset="'.
-               encodeHeader($charset). '"';
-       }
-
-
-       $header[] = $contenttype . $rn;
-       if ($mime_header->description) {
-           $header[] .= 'Content-Description: ' . $mime_header->description . $rn;
-       }
-       if ($mime_header->encoding) {
-           $encoding = $mime_header->encoding;
-           $header[] .= 'Content-Transfer-Encoding: ' . $mime_header->encoding . $rn;
-       } else {
-           if ($mime_header->type0 == 'text' || $mime_header->type0 == 'message') {
-               $header[] .= 'Content-Transfer-Encoding: 8bit' .  $rn;
-           } else {
-               $header[] .= 'Content-Transfer-Encoding: base64' .  $rn;
-           }
-       }
-       if ($mime_header->id) {
-           $header[] .= 'Content-ID: ' . $mime_header->id . $rn;
-       }
-       if ($mime_header->disposition) {
-           $disposition = $mime_header->disposition;
-           $contentdisp = 'Content-Disposition: ' . $disposition->name;
-           if ($disposition->getProperty('filename')) {
-               $contentdisp .= '; filename="'.
-                   encodeHeader($disposition->getProperty('filename')). '"';
-           }
-           $header[] = $contentdisp . $rn;       
-       }
-       if ($mime_header->md5) {
-           $header[] .= 'Content-MD5: ' . $mime_header->md5 . $rn;
-       }
-       if ($mime_header->language) {
-           $header[] .= 'Content-Language: ' . $mime_header->language . $rn;
-       }
-
-       $cnt = count($header);
-       $hdr_s = '';
-       for ($i = 0 ; $i < $cnt ; $i++) {
-           $hdr_s .= $this->foldLine($header[$i], 78,str_pad('',4));
-       }
-       $header = $hdr_s;
-       $header .= $rn; /* One blank line to separate mimeheader and body-entity */
-       return $header;
-    }    
+        $mime_header = $message->mime_header;
+        $rn="\r\n";
+        $header = array();
+
+        $contenttype = 'Content-Type: '. $mime_header->type0 .'/'.
+                        $mime_header->type1;
+        if (count($message->entities)) {
+            $contenttype .= ';' . 'boundary="'.$boundary.'"';
+        }
+        if (isset($mime_header->parameters['name'])) {
+            $contenttype .= '; name="'.
+            encodeHeader($mime_header->parameters['name']). '"';
+        }
+        if (isset($mime_header->parameters['charset'])) {
+            $charset = $mime_header->parameters['charset'];
+            $contenttype .= '; charset="'.
+            encodeHeader($charset). '"';
+        }
+
+        $header[] = $contenttype . $rn;
+        if ($mime_header->description) {
+            $header[] = 'Content-Description: ' . $mime_header->description . $rn;
+        }
+        if ($mime_header->encoding) {
+            $header[] = 'Content-Transfer-Encoding: ' . $mime_header->encoding . $rn;
+        } else {
+            if ($mime_header->type0 == 'text' || $mime_header->type0 == 'message') {
+                $header[] = 'Content-Transfer-Encoding: 8bit' .  $rn;
+            } else {
+                $header[] = 'Content-Transfer-Encoding: base64' .  $rn;
+            }
+        }
+        if ($mime_header->id) {
+            $header[] = 'Content-ID: ' . $mime_header->id . $rn;
+        }
+        if ($mime_header->disposition) {
+            $disposition = $mime_header->disposition;
+            $contentdisp = 'Content-Disposition: ' . $disposition->name;
+            if ($disposition->getProperty('filename')) {
+                $contentdisp .= '; filename="'.
+                encodeHeader($disposition->getProperty('filename')). '"';
+            }
+            $header[] = $contentdisp . $rn;
+        }
+        if ($mime_header->md5) {
+            $header[] = 'Content-MD5: ' . $mime_header->md5 . $rn;
+        }
+        if ($mime_header->language) {
+            $header[] = 'Content-Language: ' . $mime_header->language . $rn;
+        }
+
+        $cnt = count($header);
+        $hdr_s = '';
+        for ($i = 0 ; $i < $cnt ; $i++)    {
+            $hdr_s .= $this->foldLine($header[$i], 78,str_pad('',4));
+        }
+        $header = $hdr_s;
+        $header .= $rn; /* One blank line to separate mimeheader and body-entity */
+        return $header;
+    }
 
+    /**
+     * function prepareRFC822_Header - prepares the RFC822 header string from Rfc822Header object(s)
+     *
+     * This function takes the Rfc822Header object(s) and formats them
+     * into the RFC822Header string to send to the SMTP server as part
+     * of the SMTP message.
+     *
+     * @param Rfc822Header  $rfc822_header
+     * @param Rfc822Header  $reply_rfc822_header
+     * @param integer      &$raw_length length of the message
+     *
+     * @return string $header
+     */
     function prepareRFC822_Header($rfc822_header, $reply_rfc822_header, &$raw_length) {
-        $REMOTE_ADDR = $_SERVER['REMOTE_ADDR'];
-        $SERVER_NAME = $_SERVER['SERVER_NAME'];
-        $REMOTE_PORT = $_SERVER['REMOTE_PORT'];
-        if(isset($_SERVER['REMOTE_HOST'])) {
-            $REMOTE_HOST = $_SERVER['REMOTE_HOST'];
-        }
-        if(isset($_SERVER['HTTP_VIA'])) {
-            $HTTP_VIA = $_SERVER['HTTP_VIA'];
-        }
-        if(isset($_SERVER['HTTP_X_FORWARDED_FOR'])) {
-            $HTTP_X_FORWARDED_FOR = $_SERVER['HTTP_X_FORWARDED_FOR'];
-        }
-       global $version, $username;
-       $rn = "\r\n";
-       /* This creates an RFC 822 date */
-       $date = date('D, j M Y H:i:s ', mktime()) . $this->timezone();
-       /* Create a message-id */
-       $message_id = '<' . $REMOTE_PORT . '.' . $REMOTE_ADDR . '.';
-       $message_id .= time() . '.squirrel@' . $SERVER_NAME .'>';
-       /* Make an RFC822 Received: line */
-       if (isset($REMOTE_HOST)) {
-           $received_from = "$REMOTE_HOST ([$REMOTE_ADDR])";
-       } else {
-           $received_from = $REMOTE_ADDR;
-       }
-       if (isset($HTTP_VIA) || isset ($HTTP_X_FORWARDED_FOR)) {
-           if (!isset($HTTP_X_FORWARDED_FOR) || $HTTP_X_FORWARDED_FOR == '') {
-               $HTTP_X_FORWARDED_FOR = 'unknown';
-           }
-           $received_from .= " (proxying for $HTTP_X_FORWARDED_FOR)";
-       }
-       $header = array();
-       $header[] = "Received: from $received_from" . $rn;
-        $header[] = "        (SquirrelMail authenticated user $username)" . $rn;
-        $header[] = "        by $SERVER_NAME with HTTP;" . $rn;
-       $header[] = "        $date" . $rn;
+        global $domain, $version, $username, $encode_header_key, $edit_identity, $hide_auth_header;
+
+        /* if server var SERVER_NAME not available, use $domain */
+        if(!sqGetGlobalVar('SERVER_NAME', $SERVER_NAME, SQ_SERVER)) {
+            $SERVER_NAME = $domain;
+        }
+
+        sqGetGlobalVar('REMOTE_ADDR', $REMOTE_ADDR, SQ_SERVER);
+        sqGetGlobalVar('REMOTE_PORT', $REMOTE_PORT, SQ_SERVER);
+        sqGetGlobalVar('REMOTE_HOST', $REMOTE_HOST, SQ_SERVER);
+        sqGetGlobalVar('HTTP_VIA',    $HTTP_VIA,    SQ_SERVER);
+        sqGetGlobalVar('HTTP_X_FORWARDED_FOR', $HTTP_X_FORWARDED_FOR, SQ_SERVER);
+
+        $rn = "\r\n";
+
+        /* This creates an RFC 822 date */
+        $date = date('D, j M Y H:i:s ', mktime()) . $this->timezone();
+        /* Create a message-id */
+        $message_id = '<' . $REMOTE_PORT . '.';
+        if (isset($encode_header_key) && trim($encode_header_key)!='') {
+            // use encrypted form of remote address
+            $message_id.= OneTimePadEncrypt($this->ip2hex($REMOTE_ADDR),base64_encode($encode_header_key));
+        } else {
+            $message_id.= $REMOTE_ADDR;
+        }
+        $message_id .= '.' . time() . '.squirrel@' . $SERVER_NAME .'>';
+        /* Make an RFC822 Received: line */
+        if (isset($REMOTE_HOST)) {
+            $received_from = "$REMOTE_HOST ([$REMOTE_ADDR])";
+        } else {
+            $received_from = $REMOTE_ADDR;
+        }
+        if (isset($HTTP_VIA) || isset ($HTTP_X_FORWARDED_FOR)) {
+            if (!isset($HTTP_X_FORWARDED_FOR) || $HTTP_X_FORWARDED_FOR == '') {
+                $HTTP_X_FORWARDED_FOR = 'unknown';
+            }
+            $received_from .= " (proxying for $HTTP_X_FORWARDED_FOR)";
+        }
+        $header = array();
+
+        /**
+         * SquirrelMail header
+         *
+         * This Received: header provides information that allows to track
+         * user and machine that was used to send email. Don't remove it
+         * unless you understand all possible forging issues or your
+         * webmail installation does not prevent changes in user's email address.
+         * See SquirrelMail bug tracker #847107 for more details about it.
+         */
+        if (isset($encode_header_key) && 
+            trim($encode_header_key)!='') {
+            // use encoded headers, if encryption key is set and not empty
+            $header[].= 'X-Squirrel-UserHash: '.OneTimePadEncrypt($username,base64_encode($encode_header_key)).$rn;
+            $header[].= 'X-Squirrel-FromHash: '.OneTimePadEncrypt($this->ip2hex($REMOTE_ADDR),base64_encode($encode_header_key)).$rn;
+            if (isset($HTTP_X_FORWARDED_FOR))
+                $header[].= 'X-Squirrel-ProxyHash:'.OneTimePadEncrypt($this->ip2hex($HTTP_X_FORWARDED_FOR),base64_encode($encode_header_key)).$rn;
+        } else {
+            // use default received headers
+            $header[] = "Received: from $received_from" . $rn;
+            if ($edit_identity || ! isset($hide_auth_header) || ! $hide_auth_header)
+                $header[] = "        (SquirrelMail authenticated user $username)" . $rn;
+            $header[] = "        by $SERVER_NAME with HTTP;" . $rn;
+            $header[] = "        $date" . $rn;
+        }
+
         /* Insert the rest of the header fields */
         $header[] = 'Message-ID: '. $message_id . $rn;
         if ($reply_rfc822_header->message_id) {
-           $rep_message_id = $reply_rfc822_header->message_id;
-//         $this->strip_crlf($message_id);
-           $header[] = 'In-Reply-To: '.$rep_message_id . $rn;
-           $references = $this->calculate_references($reply_rfc822_header);
-           $header[] = 'References: '.$references . $rn;
-       }       
-       $header[] = "Date: $date" . $rn;
+            $rep_message_id = $reply_rfc822_header->message_id;
+        //        $this->strip_crlf($message_id);
+            $header[] = 'In-Reply-To: '.$rep_message_id . $rn;
+            $references = $this->calculate_references($reply_rfc822_header);
+            $header[] = 'References: '.$references . $rn;
+        }
+        $header[] = "Date: $date" . $rn;
         $header[] = 'Subject: '.encodeHeader($rfc822_header->subject) . $rn;
-        $header[] = 'From: '. $rfc822_header->getAddr_s('from',',',true) . $rn;
-       /* RFC2822 if from contains more then 1 address */      
+        $header[] = 'From: '. $rfc822_header->getAddr_s('from',",$rn ",true) . $rn;
+
+        // folding address list [From|To|Cc|Bcc] happens by using ",$rn<space>" as delimiter
+        // Do not use foldLine for that.
+
+        // RFC2822 if from contains more then 1 address
         if (count($rfc822_header->from) > 1) {
-           $header[] = 'Sender: '. $rfc822_header->getAddr_s('sender',',',true) . $rn;
-       }
-       if (count($rfc822_header->to)) {
-           $header[] = 'To: '. $rfc822_header->getAddr_s('to',',',true) . $rn;
-        }
-       if (count($rfc822_header->cc)) {
-           $header[] = 'Cc: '. $rfc822_header->getAddr_s('cc',',',true) . $rn;
-       }
-       if (count($rfc822_header->reply_to)) {
-           $header[] = 'Reply-To: '. $rfc822_header->getAddr_s('reply_to',',',true) . $rn;
-       }
-       /* Sendmail should return true. Default = false */
-       $bcc = $this->getBcc();
-       if (count($rfc822_header->bcc)) {
-           $s = 'Bcc: '. $rfc822_header->getAddr_s('bcc',',',true) . $rn;
-           if (!$bcc) {
-              $s = $this->foldLine($s, 78, str_pad('',4));
-              $raw_length += strlen($s);
-           } else {
-              $header[] = $s;
-           }
-       }
-       /* Identify SquirrelMail */     
-       $header[] = 'User-Agent: SquirrelMail/' . $version . $rn; 
-       /* Do the MIME-stuff */
-       $header[] = 'MIME-Version: 1.0' . $rn;
-       $contenttype = 'Content-Type: '. $rfc822_header->content_type->type0 .'/'.
+            $header[] = 'Sender: '. $rfc822_header->getAddr_s('sender',',',true) . $rn;
+        }
+        if (count($rfc822_header->to)) {
+            $header[] = 'To: '. $rfc822_header->getAddr_s('to',",$rn ",true) . $rn;
+        }
+        if (count($rfc822_header->cc)) {
+            $header[] = 'Cc: '. $rfc822_header->getAddr_s('cc',",$rn ",true) . $rn;
+        }
+        if (count($rfc822_header->reply_to)) {
+            $header[] = 'Reply-To: '. $rfc822_header->getAddr_s('reply_to',',',true) . $rn;
+        }
+        /* Sendmail should return true. Default = false */
+        $bcc = $this->getBcc();
+        if (count($rfc822_header->bcc)) {
+            $s = 'Bcc: '. $rfc822_header->getAddr_s('bcc',",$rn ",true) . $rn;
+            if (!$bcc) {
+                $raw_length += strlen($s);
+            } else {
+                $header[] = $s;
+            }
+        }
+        /* Identify SquirrelMail */
+        $header[] = 'User-Agent: SquirrelMail/' . $version . $rn;
+        /* Do the MIME-stuff */
+        $header[] = 'MIME-Version: 1.0' . $rn;
+        $contenttype = 'Content-Type: '. $rfc822_header->content_type->type0 .'/'.
                                          $rfc822_header->content_type->type1;
-       if (count($rfc822_header->content_type->properties)) {
-           foreach ($rfc822_header->content_type->properties as $k => $v) {
-               if ($k && $v) {
-                   $contenttype .= ';' .$k.'='.$v; 
-               }
-           }
-       }
+        if (count($rfc822_header->content_type->properties)) {
+            foreach ($rfc822_header->content_type->properties as $k => $v) {
+                if ($k && $v) {
+                    $contenttype .= ';' .$k.'='.$v;
+                }
+            }
+        }
         $header[] = $contenttype . $rn;
+        if ($encoding = $rfc822_header->encoding) {
+            $header[] = 'Content-Transfer-Encoding: ' . $encoding .  $rn;
+        }
         if ($rfc822_header->dnt) {
-           $dnt = $rfc822_header->getAddr_s('dnt'); 
-           /* Pegasus Mail */
-           $header[] = 'X-Confirm-Reading-To: '.$dnt. $rn;
-           /* RFC 2298 */
-           $header[] = 'Disposition-Notification-To: '.$dnt. $rn;
-       }
-       if ($rfc822_header->priority) {
-           $prio = $rfc822_header->priority;
-           $header[] = 'X-Priority: '.$prio. $rn;
-           switch($prio) {
-             case 1: $header[] = 'Importance: High'. $rn; break;
-             case 3: $header[] = 'Importance: Normal'. $rn; break;
-             case 5: $header[] = 'Importance: Low'. $rn; break;
-             default: break;
-           }
-       }
-       /* Insert headers from the $more_headers array */       
-       if(count($rfc822_header->more_headers)) {
-           reset($rfc822_header->more_headers);
-           foreach ($rfc822_header->more_headers as $k => $v) {
-               $header[] = $k.': '.$v .$rn;
-           }          
-       }        
-       $cnt = count($header);
-       $hdr_s = '';
-       for ($i = 0 ; $i < $cnt ; $i++) {
-           $hdr_s .= $this->foldLine($header[$i], 78, str_pad('',4));
-       }
-//     $debug = "Debug: <123456789012345678901234567890123456789012345678901234567890123456789>\r\n";
-//     $this->foldLine($debug, 78, str_pad('',4));
-       $header = $hdr_s;
-       $header .= $rn; /* One blank line to separate header and body */
-       $raw_length += strlen($header);
-       return $header;
+            $dnt = $rfc822_header->getAddr_s('dnt');
+            /* Pegasus Mail */
+            $header[] = 'X-Confirm-Reading-To: '.$dnt. $rn;
+            /* RFC 2298 */
+            $header[] = 'Disposition-Notification-To: '.$dnt. $rn;
+        }
+        if ($rfc822_header->priority) {
+            switch($rfc822_header->priority)
+            {
+            case 1:
+                $header[] = 'X-Priority: 1 (Highest)'.$rn;
+                $header[] = 'Importance: High'. $rn; break;
+            case 5:
+                $header[] = 'X-Priority: 5 (Lowest)'.$rn;
+                $header[] = 'Importance: Low'. $rn; break;
+            default: break;
+            }
+        }
+        /* Insert headers from the $more_headers array */
+        if(count($rfc822_header->more_headers)) {
+            reset($rfc822_header->more_headers);
+            foreach ($rfc822_header->more_headers as $k => $v) {
+                $header[] = $k.': '.$v .$rn;
+            }
+        }
+        $cnt = count($header);
+        $hdr_s = '';
+
+        for ($i = 0 ; $i < $cnt ; $i++) {
+            $sKey = substr($header[$i],0,strpos($header[$i],':'));
+            switch ($sKey)
+            {
+            case 'Message-ID':
+            case 'In-Reply_To':
+                $hdr_s .= $header[$i];
+                break;
+            case 'References':
+                $sRefs = substr($header[$i],12);
+                $aRefs = explode(' ',$sRefs);
+                $sLine = 'References:';
+                foreach ($aRefs as $sReference) {
+                    if (strlen($sLine)+strlen($sReference) >76) {
+                        $hdr_s .= $sLine;
+                        $sLine = $rn . '    ' . $sReference;
+                    } else {
+                        $sLine .= ' '. $sReference;
+                    }
+                }
+                $hdr_s .= $sLine;
+                break;
+            case 'To':
+            case 'Cc':
+            case 'Bcc':
+            case 'From':
+                $hdr_s .= $header[$i];
+                break;
+            default: $hdr_s .= $this->foldLine($header[$i], 78, str_pad('',4)); break;
+            }
+        }
+        $header = $hdr_s;
+        $header .= $rn; /* One blank line to separate header and body */
+        $raw_length += strlen($header);
+        return $header;
     }
 
-    /*
-    * function for cleanly folding of headerlines
-    */
+    /**
+     * function foldLine - for cleanly folding of headerlines
+     *
+     * @param   string  $line
+     * @param   integer $length length to fold the line at
+     * @param   string  $pre    prefix the line with...
+     *
+     * @return string   $line folded line with trailing CRLF
+     */
     function foldLine($line, $length, $pre='') {
         $line = substr($line,0, -2);
         $length -= 2; /* do not fold between \r and \n */
@@ -363,14 +580,20 @@ class Deliver {
             while (strlen($line) > $length) {
                 $fold = false;
                 /* handle encoded parts */
-                if (preg_match('/(=\?.+\?.+\?.+\?=)/',$line,$regs)) {
+                if (preg_match('/(=\?([^?]*)\?(Q|B)\?([^?]*)\?=)(\s+|.*)/Ui',$line,$regs)) {
                     $fold_tmp = $regs[1];
+                    if (!trim($regs[5])) {
+                        $fold_tmp .= $regs[5];
+                    }
                     $iPosEnc = strpos($line,$fold_tmp);
                     $iLengthEnc = strlen($fold_tmp);
-                    if ($iPosEnc < $length && ($iPosEnc + $iLengthEnc > $length)) {
+                    $iPosEncEnd = $iPosEnc+$iLengthEnc;
+                    if ($iPosEnc < $length && (($iPosEncEnd) > $length)) {
                         $fold = true;
                         /* fold just before the start of the encoded string */
-                        $aFoldLine[] = substr($line,0,$iPosEnc);
+                        if ($iPosEnc) {
+                            $aFoldLine[] = substr($line,0,$iPosEnc);
+                        }
                         $line = substr($line,$iPosEnc);
                         if (!$bFirstFold) {
                             $bFirstFold = true;
@@ -378,21 +601,18 @@ class Deliver {
                         }
                         if ($iLengthEnc > $length) { /* place the encoded
                             string on a separate line and do not fold inside it*/
-                            if ($iLengthEnc < (998 - strlen($fold_string))) { 
-                                $aFoldLine[] = substr($line,0,$iLengthEnc);
-                                $line = substr($line,$iLengthEnc);
-                            } else { /* line is too long, continue with normal folding */
-                                $fold = false;
-                            }
+                            /* minimize foldstring */
+                            $fold_string = "\r\n ";
+                            $aFoldLine[] = substr($line,0,$iLengthEnc);
+                            $line = substr($line,$iLengthEnc);
                         }
-                    } else { /* the encoded string fits into the foldlength */
+                    } else if ($iPosEnc < $length) { /* the encoded string fits into the foldlength */
                         /*remainder */
-                        $iPosEncEnd = $iPosEnc+$iLengthEnc;
                         $sLineRem = substr($line,$iPosEncEnd,$length - $iPosEncEnd);
-                        if (!preg_match('/[=,;\s]/',$sLineRem)) {
+                        if (preg_match('/^(=\?([^?]*)\?(Q|B)\?([^?]*)\?=)(.*)/Ui',$sLineRem) || !preg_match('/[=,;\s]/',$sLineRem)) {
                             /*impossible to fold clean in the next part -> fold after the enc string */
-                            $aFoldLine[] = substr($line,0,$iPosEncEnd+1);
-                            $line = substr($line,$iPosEncEnd+1);
+                            $aFoldLine[] = substr($line,0,$iPosEncEnd);
+                            $line = substr($line,$iPosEncEnd);
                             $fold = true;
                             if (!$bFirstFold) {
                                 $bFirstFold = true;
@@ -413,7 +633,7 @@ class Deliver {
                     case ($iFoldPos = strrpos($line_tmp,'=')): break;
                     default: break;
                     }
-                    
+
                     if (!$iFoldPos) { /* clean folding didn't work */
                         $iFoldPos = $length;
                     }
@@ -434,54 +654,134 @@ class Deliver {
         return $line."\r\n";
     }
 
+    /**
+     * function mimeBoundary - calculates the mime boundary to use
+     *
+     * This function will generate a random mime boundary base part
+     * for the message if the boundary has not already been set.
+     *
+     * @return string $mimeBoundaryString random mime boundary string
+     */
     function mimeBoundary () {
-       static $mimeBoundaryString;
-
-       if ( !isset( $mimeBoundaryString ) ||
-           $mimeBoundaryString == '') {
-           $mimeBoundaryString = '----=_' . date( 'YmdHis' ) . '_' .
-               mt_rand( 10000, 99999 );
-       }
-       return $mimeBoundaryString;
+        static $mimeBoundaryString;
+
+        if ( !isset( $mimeBoundaryString ) ||
+            $mimeBoundaryString == '') {
+            $mimeBoundaryString = '----=_' . date( 'YmdHis' ) . '_' .
+            mt_rand( 10000, 99999 );
+        }
+        return $mimeBoundaryString;
     }
 
-    /* Time offset for correct timezone */
+    /**
+     * function timezone - Time offset for correct timezone
+     *
+     * @return string $result with timezone and offset
+     */
     function timezone () {
-       global $invert_time;
-    
-       $diff_second = date('Z');
-       if ($invert_time) {
-           $diff_second = - $diff_second;
-       }
-       if ($diff_second > 0) {
-           $sign = '+';
-       } else {
-           $sign = '-';
-       }
-       $diff_second = abs($diff_second);
-       $diff_hour = floor ($diff_second / 3600);
-       $diff_minute = floor (($diff_second-3600*$diff_hour) / 60);
-       $zonename = '('.strftime('%Z').')';
-       $result = sprintf ("%s%02d%02d %s", $sign, $diff_hour, $diff_minute, 
+        global $invert_time;
+
+        $diff_second = date('Z');
+        if ($invert_time) {
+            $diff_second = - $diff_second;
+        }
+        if ($diff_second > 0) {
+            $sign = '+';
+        } else {
+            $sign = '-';
+        }
+        $diff_second = abs($diff_second);
+        $diff_hour = floor ($diff_second / 3600);
+        $diff_minute = floor (($diff_second-3600*$diff_hour) / 60);
+        $zonename = '('.strftime('%Z').')';
+        $result = sprintf ("%s%02d%02d %s", $sign, $diff_hour, $diff_minute,
                        $zonename);
-       return ($result);
+        return ($result);
     }
 
+    /**
+     * function calculate_references - calculate correct Referer string
+     *
+     * @param   Rfc822Header $hdr    message header to calculate from
+     *
+     * @return  string       $refer  concatenated and trimmed Referer string
+     */
     function calculate_references($hdr) {
         $refer = $hdr->references;
-       $message_id = $hdr->message_id;
-       $in_reply_to = $hdr->in_reply_to;
-       if (strlen($refer) > 2) {
-           $refer .= ' ' . $message_id;
-       } else {
-           if ($in_reply_to) {
-               $refer .= $in_reply_to . ' ' . $message_id;
-           } else {
-               $refer .= $message_id;
-           }                        
-       }
-       trim($refer);
-       return $refer;
+        $message_id = $hdr->message_id;
+        $in_reply_to = $hdr->in_reply_to;
+        if (strlen($refer) > 2) {
+            $refer .= ' ' . $message_id;
+        } else {
+            if ($in_reply_to) {
+                $refer .= $in_reply_to . ' ' . $message_id;
+            } else {
+                $refer .= $message_id;
+            }
+        }
+        trim($refer);
+        return $refer;
+    }
+
+    /**
+     * Converts ip address to hexadecimal string
+     *
+     * Function is used to convert ipv4 and ipv6 addresses to hex strings.
+     * It removes all delimiter symbols from ip addresses, converts decimal
+     * ipv4 numbers to hex and pads strings in order to present full length
+     * address. ipv4 addresses are represented as 8 byte strings, ipv6 addresses 
+     * are represented as 32 byte string.
+     *
+     * If function fails to detect address format, it returns unprocessed string.
+     * @param string $string ip address string
+     * @return string processed ip address string
+     * @since 1.5.1
+     */
+    function ip2hex($string) {
+        if (preg_match("/^(\d+)\.(\d+)\.(\d+)\.(\d+)$/",$string,$match)) {
+            // ipv4 address
+            $ret = str_pad(dechex($match[1]),2,'0',STR_PAD_LEFT)
+                . str_pad(dechex($match[2]),2,'0',STR_PAD_LEFT)
+                . str_pad(dechex($match[3]),2,'0',STR_PAD_LEFT)
+                . str_pad(dechex($match[4]),2,'0',STR_PAD_LEFT);
+        } elseif (preg_match("/^([0-9a-h]+)\:([0-9a-h]+)\:([0-9a-h]+)\:([0-9a-h]+)\:([0-9a-h]+)\:([0-9a-h]+)\:([0-9a-h]+)\:([0-9a-h]+)$/i",$string,$match)) {
+            // full ipv6 address
+            $ret = str_pad($match[1],4,'0',STR_PAD_LEFT)
+                . str_pad($match[2],4,'0',STR_PAD_LEFT)
+                . str_pad($match[3],4,'0',STR_PAD_LEFT)
+                . str_pad($match[4],4,'0',STR_PAD_LEFT)
+                . str_pad($match[5],4,'0',STR_PAD_LEFT)
+                . str_pad($match[6],4,'0',STR_PAD_LEFT)
+                . str_pad($match[7],4,'0',STR_PAD_LEFT)
+                . str_pad($match[8],4,'0',STR_PAD_LEFT);
+        } elseif (preg_match("/^\:\:([0-9a-h\:]+)$/i",$string,$match)) {
+            // short ipv6 with all starting symbols nulled
+            $aAddr=explode(':',$match[1]);
+            $ret='';
+            foreach ($aAddr as $addr) {
+                $ret.=str_pad($addr,4,'0',STR_PAD_LEFT);
+            }
+            $ret=str_pad($ret,32,'0',STR_PAD_LEFT);
+        } elseif (preg_match("/^([0-9a-h\:]+)::([0-9a-h\:]+)$/i",$string,$match)) {
+            // short ipv6 with middle part nulled
+            $aStart=explode(':',$match[1]);
+            $sStart='';
+            foreach($aStart as $addr) {
+                $sStart.=str_pad($addr,4,'0',STR_PAD_LEFT);
+            }
+            $aEnd = explode(':',$match[2]);
+            $sEnd='';
+            foreach($aEnd as $addr) {
+                $sEnd.=str_pad($addr,4,'0',STR_PAD_LEFT);
+            }
+            $ret = $sStart
+                . str_pad('',(32 - strlen($sStart . $sEnd)),'0',STR_PAD_LEFT)
+                . $sEnd;
+        } else {
+            // unknown addressing
+            $ret = $string;
+        }
+        return $ret;
     }
 }
-?>
+?>
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