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[squirrelmail.git] / class / mime / Rfc822Header.class.php
index e6562fe58927e5f8c343191341981f9e9faf317a..8b77b8bb96d29818550e9d0455aa46d68d735beb 100644 (file)
 /**
  * Rfc822Header.class.php
  *
- * Copyright (c) 2003 The SquirrelMail Project Team
- * Licensed under the GNU GPL. For full terms see the file COPYING.
+ * This file contains functions needed to handle headers in mime messages.
  *
- * This contains functions needed to handle mime messages.
- *
- * $Id$
+ * @copyright 2003-2020 The SquirrelMail Project Team
+ * @license http://opensource.org/licenses/gpl-license.php GNU Public License
+ * @version $Id$
+ * @package squirrelmail
+ * @subpackage mime
+ * @since 1.3.2
  */
 
-/*
- * rdc822_header class
+/**
+ * MIME header class
  * input: header_string or array
+ * You must call parseHeader() function after creating object in order to fill object's
+ * parameters.
+ * @todo FIXME: there is no constructor function and class should ignore all input args.
+ * @package squirrelmail
+ * @subpackage mime
+ * @since 1.3.0
  */
 class Rfc822Header {
-    var $date = '',
-        $subject = '',
-        $from = array(),
-        $sender = '',
-        $reply_to = array(),
-        $to = array(),
-        $cc = array(),
-        $bcc = array(),
-        $in_reply_to = '',
-        $message_id = '',
-        $references = '',
-        $mime = false,
-        $content_type = '',
-        $disposition = '',
-        $xmailer = '',
-        $priority = 3,
-        $dnt = '',
-        $mlist = array(),
-        $more_headers = array(); /* only needed for constructing headers
-                                    in smtp.php */
+    /**
+     * All headers, unparsed
+     * @var array
+     */
+    var $raw_headers = array();
+    /**
+     * Date header
+     * @var mixed
+     */
+    var $date = -1;
+    /**
+     * Original date header as fallback for unparsable dates
+     * @var mixed
+     */
+    var $date_unparsed = '';
+    /**
+     * Subject header
+     * @var string
+     */
+    var $subject = '';
+    /**
+     * From header
+     * @var array
+     */
+    var $from = array();
+    /**
+     * @var mixed
+     */
+    var $sender = '';
+    /**
+     * Reply-To header
+     * @var array
+     */
+    var $reply_to = array();
+    /**
+     * Mail-Followup-To header
+     * @var array
+     */
+    var $mail_followup_to = array();
+    /**
+     * To header
+     * @var array
+     */
+    var $to = array();
+    /**
+     * Cc header
+     * @var array
+     */
+    var $cc = array();
+    /**
+     * Bcc header
+     * @var array
+     */
+    var $bcc = array();
+    /**
+     * In-reply-to header
+     * @var string
+     */
+    var $in_reply_to = '';
+    /**
+     * Message-ID header
+     * @var string
+     */
+    var $message_id = '';
+    /**
+     * References header
+     * @var string
+     */
+    var $references = '';
+    /**
+     * @var mixed
+     */
+    var $mime = false;
+    /**
+     * Content Type object
+     * @var object
+     */
+    var $content_type = '';
+    /**
+     * @var mixed
+     */
+    var $disposition = '';
+    /**
+     * X-Mailer header
+     * @var string
+     */
+    var $xmailer = '';
+    /**
+     * Priority header
+     * @var integer
+     */
+    var $priority = 3;
+    /**
+     * Disposition notification for requesting message delivery notification (MDN)
+     * @var mixed
+     */
+    var $dnt = '';
+    /**
+     * Delivery notification (DR)
+     * @var mixed
+     */
+    var $drnt = '';
+    /**
+     * @var mixed
+     */
+    var $encoding = '';
+    /**
+     * @var mixed
+     */
+    var $content_id = '';
+    /**
+     * @var mixed
+     */
+    var $content_desc = '';
+    /**
+     * @var mixed
+     */
+    var $mlist = array();
+    /**
+     * SpamAssassin 'x-spam-status' header
+     * @var mixed
+     */
+    var $x_spam_status = array();
+    /**
+     * Extra header
+     * only needed for constructing headers in delivery class
+     * @var array
+     */
+    var $more_headers = array();
+
+    /**
+     * @param mixed $hdr string or array with message headers
+     */
     function parseHeader($hdr) {
         if (is_array($hdr)) {
             $hdr = implode('', $hdr);
         }
-
-        /* First we unfold the header */
-        $hdr = trim(str_replace(array("\r\n\t", "\r\n "),array('', ''), $hdr));
+        /* First we replace \r\n by \n and unfold the header */
+        /* FIXME: unfolding header with multiple spaces "\n( +)" */
+        $hdr = trim(str_replace(array("\r\n", "\n\t", "\n "),array("\n", ' ', ' '), $hdr));
 
         /* Now we can make a new header array with */
         /* each element representing a headerline  */
-        $hdr = explode("\r\n" , $hdr);
+        $hdr = explode("\n" , $hdr);
         foreach ($hdr as $line) {
             $pos = strpos($line, ':');
             if ($pos > 0) {
+                $this->raw_headers[] = $line;
                 $field = substr($line, 0, $pos);
                 if (!strstr($field,' ')) { /* valid field */
                         $value = trim(substr($line, $pos+1));
@@ -57,11 +179,15 @@ class Rfc822Header {
                 }
             }
         }
-        if ($this->content_type == '') {
+        if (!is_object($this->content_type)) {
             $this->parseContentType('text/plain; charset=us-ascii');
         }
     }
 
+    /**
+     * @param string $value
+     * @return string
+     */
     function stripComments($value) {
         $result = '';
         $cnt = strlen($value);
@@ -76,7 +202,9 @@ class Rfc822Header {
                         }
                         $result .= $value{$i};
                     }
-                    $result .= $value{$i};
+                    if($i < $cnt) {
+                        $result .= $value{$i};
+                    }
                     break;
                 case '(':
                     $depth = 1;
@@ -104,6 +232,11 @@ class Rfc822Header {
         return $result;
     }
 
+    /**
+     * Parse header field according to field type
+     * @param string $field field name
+     * @param string $value field value
+     */
     function parseField($field, $value) {
         $field = strtolower($field);
         switch($field) {
@@ -112,6 +245,7 @@ class Rfc822Header {
                 $d = strtr($value, array('  ' => ' '));
                 $d = explode(' ', $d);
                 $this->date = getTimeStamp($d);
+                $this->date_unparsed = strtr($value,'<>','  ');
                 break;
             case 'subject':
                 $this->subject = $value;
@@ -125,6 +259,9 @@ class Rfc822Header {
             case 'reply-to':
                 $this->reply_to = $this->parseAddress($value, true);
                 break;
+            case 'mail-followup-to':
+                $this->mail_followup_to = $this->parseAddress($value, true);
+                break;
             case 'to':
                 $this->to = $this->parseAddress($value, true);
                 break;
@@ -146,11 +283,14 @@ class Rfc822Header {
                 $this->references = $value;
                 break;
             case 'x-confirm-reading-to':
-            case 'return-receipt-to':
             case 'disposition-notification-to':
                 $value = $this->stripComments($value);
                 $this->dnt = $this->parseAddress($value);
                 break;
+            case 'return-receipt-to':
+                $value = $this->stripComments($value);
+                $this->drnt = $this->parseAddress($value);
+                break;
             case 'mime-version':
                 $value = $this->stripComments($value);
                 $value = str_replace(' ', '', $value);
@@ -164,23 +304,35 @@ class Rfc822Header {
                 $value = $this->stripComments($value);
                 $this->parseDisposition($value);
                 break;
+            case 'content-transfer-encoding':
+                $this->encoding = $value;
+                break;
+            case 'content-description':
+                $this->content_desc = $value;
+                break;
+            case 'content-id':
+                $value = $this->stripComments($value);
+                $this->content_id = $value;
+                break;
             case 'user-agent':
             case 'x-mailer':
                 $this->xmailer = $value;
                 break;
             case 'x-priority':
-                $this->priority = $value;
+            case 'importance':
+            case 'priority':
+                $this->priority = $this->parsePriority($value);
                 break;
             case 'list-post':
                 $value = $this->stripComments($value);
                 $this->mlist('post', $value);
                 break;
             case 'list-reply':
-                $value = $this->stripComments($value);            
+                $value = $this->stripComments($value);
                 $this->mlist('reply', $value);
                 break;
             case 'list-subscribe':
-                $value = $this->stripComments($value);            
+                $value = $this->stripComments($value);
                 $this->mlist('subscribe', $value);
                 break;
             case 'list-unsubscribe':
@@ -203,334 +355,344 @@ class Rfc822Header {
                 $value = $this->stripComments($value);
                 $this->mlist('id', $value);
                 break;
+            case 'x-spam-status':
+            case 'x-spam-score':
+                $this->x_spam_status = $this->parseSpamStatus($value);
+                break;
+            case 'x-sm-flag-reply':
+                $this->x_sm_flag_reply = $value;
+                break;
             default:
                 break;
         }
     }
-    /*
-     * parseAddress: recursive function for parsing address strings and store 
-     *               them in an address stucture object.
-     *               input: $address = string
-     *                      $ar      = boolean (return array instead of only the
-     *                                 first element)
-     *                      $addr_ar = array with parsed addresses
-     *                      $group   = string
-     *                      $host    = string (default domainname in case of 
-     *                                 addresses without a domainname)
-     *                      $lookup  = callback function (for lookup address
-     *                                 strings which are probably nicks
-     *                                 (without @ ) ) 
-     *               output: array with addressstructure objects or only one
-     *                       address_structure object.
-     *  personal name: encoded: =?charset?Q|B?string?=
-     *                 quoted:  "string"
-     *                 normal:  string
-     *  email        : <mailbox@host>
-     *               : mailbox@host
-     *  This function is also used for validating addresses returned from compose
-     *  That's also the reason that the function became a little bit huge and horrible
-     *  Todo: Find a way to clean up this mess a bit (Marc Groot Koerkamp)
-     */
-    function parseAddress
-    ($address, $ar=false, $addr_ar = array(), $group = '', $host='',$lookup=false) {
-        $pos = 0;
-        $name = $addr = $comment = $is_encoded = '';
-        /* 
-         * in case of 8 bit addresses some how <SPACE> is represented as 
-         * NON BRAKING SPACE
-         * This only happens when we validate addresses from the compose form.
-         *
-         * Note: when other charsets have dificulties with characters 
-         * =,;:<>()"<SPACE>
-         * then we should find out the value for those characters ans replace
-         * them by proper ASCII values before we start parsing.
-         * 
-         */
-        $address = str_replace("\240",' ',$address);
-        
-        $address = trim($address);
-        $j = strlen($address);
-
-        while ($pos < $j) {
-            $char = $address{$pos};
-            switch ($char)
+
+    /**
+     * @param string $address
+     * @return array
+     */
+    function getAddressTokens($address) {
+        $aTokens = array();
+        $aSpecials = array('(' ,'<' ,',' ,';' ,':');
+        $aReplace =  array(' (',' <',' ,',' ;',' :');
+        $address = str_replace($aSpecials,$aReplace,$address);
+        $iCnt = strlen($address);
+        $i = 0;
+        while ($i < $iCnt) {
+            $cChar = $address{$i};
+            switch($cChar)
             {
-            case '=':
-                /* get the encoded personal name */
-                if (preg_match('/^(=\?([^?]*)\?(Q|B)\?([^?]*)\?=)(.*)/Ui',substr($address,$pos),$reg)) {
-                    $name .= $reg[1];
-                    $pos += strlen($reg[1]);
-                } else {
-                    ++$pos;
-                }
-                $addr_start = $pos;
-                $is_encoded = true;
-                break;
-            case '"': /* get the personal name */
-                $start_encoded = $pos;
-                ++$pos;
-                if ($address{$pos} == '"') {
-                    ++$pos;
-                } else {
-                    $personal_start = $personal_end = $pos;
-                    while ($pos < $j) {
-                        $personal_end = strpos($address,'"',$pos);
-                        if (($personal_end-2)>0 && (substr($address,$personal_end-2,2) === '\\"' ||
-                            substr($address,$personal_end-2,2) === '\\\\')) {
-                            $pos = $personal_end+1;
-                        } else {
-                            $name .= substr($address,$personal_start,$personal_end-$personal_start);
-                            break;
-                        }
-                    }
-                    if ($personal_end) {
-                        $pos = $personal_end+1;
-                    } else {
-                        $pos = $j;
-                    }
-                }
-                $addr_start = $pos;
-                break;
-            case '<':  /* get email address */
-                $addr_start = $pos;
-                $addr_end = strpos($address,'>',$addr_start);
-                $addr = substr($address,$addr_start+1,$addr_end-$addr_start-1);
-                if ($addr_end) {
-                    $pos = $addr_end+1;
+            case '<':
+                $iEnd = strpos($address,'>',$i+1);
+                if (!$iEnd) {
+                   $sToken = substr($address,$i);
+                   $i = $iCnt;
                 } else {
-                    $addr = substr($address,$addr_start+1);
-                    $pos = $j;
+                   $sToken = substr($address,$i,$iEnd - $i +1);
+                   $i = $iEnd;
                 }
+                $sToken = str_replace($aReplace, $aSpecials,$sToken);
+                if ($sToken) $aTokens[] = $sToken;
                 break;
-            case '(':  /* rip off comments */
-                $addr_start = $pos;
-                $pos = strpos($address,')');
-                if ($pos !== false) {
-                    $comment = substr($address, $addr_start+1,($pos-$addr_start-1));
-                    $address_start = substr($address, 0, $addr_start);
-                    $address_end   = substr($address, $pos + 1);
-                    $address       = $address_start . $address_end;
+            case '"':
+                $iEnd = strpos($address,$cChar,$i+1);
+                if ($iEnd) {
+                   // skip escaped quotes
+                   $prev_char = $address{$iEnd-1};
+                   while ($prev_char === '\\' && substr($address,$iEnd-2,2) !== '\\\\') {
+                       $iEnd = strpos($address,$cChar,$iEnd+1);
+                       if ($iEnd) {
+                          $prev_char = $address{$iEnd-1};
+                       } else {
+                          $prev_char = false;
+                       }
+                   }
                 }
-                $j = strlen($address);
-                $pos = $addr_start + 1;
-                break;
-            case ',':  /* we reached a delimiter */
-                if (!$name && !$addr) {
-                    $addr = substr($address, 0, $pos);
-                } else if (!$addr) {
-                    $addr = trim(substr($address, $addr_start, $pos));
-                } else if ($name == '') {
-                    $name = trim(substr($address, 0, $addr_start));
-                }                
-                $at = strpos($addr, '@');
-                $addr_structure = new AddressStructure();
-                if (!$name && $comment) $name = $comment;
-                if (!$is_encoded) {
-                    $addr_structure->personal = encodeHeader($name);
+                if (!$iEnd) {
+                    $sToken = substr($address,$i);
+                    $i = $iCnt;
                 } else {
-                    $addr_structure->personal = $name;
+                    // also remove the surrounding quotes
+                    $sToken = substr($address,$i+1,$iEnd - $i -1);
+                    $i = $iEnd;
                 }
-                $is_encoded = false;
-                $addr_structure->group = $group;
-                $grouplookup = false;
-                if ($at) {
-                    $addr_structure->mailbox = substr($addr, 0, $at);
-                    $addr_structure->host = substr($addr, $at+1);
+                $sToken = str_replace($aReplace, $aSpecials,$sToken);
+                if ($sToken) $aTokens[] = $sToken;
+                break;
+            case '(':
+                array_pop($aTokens); //remove inserted space
+                $iEnd = strpos($address,')',$i);
+                if (!$iEnd) {
+                    $sToken = substr($address,$i);
+                    $i = $iCnt;
                 } else {
-                    /* if lookup function */
-                    if ($lookup) {
-                        $aAddr = call_user_func_array($lookup,array($addr));
-                        if (isset($aAddr['email'])) {
-                            if (strpos($aAddr['email'],',')) {
-                                $grouplookup = true;
-                                $addr_ar = $this->parseAddress($aAddr['email'], $ar, $addr_ar, $group, $host,$lookup);
-                            } else {
-                                $at = strpos($aAddr['email'], '@');
-                                $addr_structure->mailbox = substr($aAddr['email'], 0, $at);
-                                $addr_structure->host = substr($aAddr['email'], $at+1);
-                                if (isset($aAddr['name'])) {
-                                    $addr_structure->personal = $aAddr['name'];
-                                } else {
-                                    $addr_structure->personal = encodeHeader($addr);
-                                }
-                            }
+                    $iDepth = 1;
+                    $iComment = $i;
+                    while (($iDepth > 0) && (++$iComment < $iCnt)) {
+                        $cCharComment = $address{$iComment};
+                        switch($cCharComment) {
+                            case '\\':
+                                ++$iComment;
+                                break;
+                            case '(':
+                                ++$iDepth;
+                                break;
+                            case ')':
+                                --$iDepth;
+                                break;
+                            default:
+                                break;
                         }
                     }
-                    if (!$grouplookup && !$addr_structure->mailbox) {
-                        $addr_structure->mailbox = trim($addr);
-                        if ($host) {
-                            $addr_structure->host = $host;
-                        }
+                    if ($iDepth == 0) {
+                        $sToken = substr($address,$i,$iComment - $i +1);
+                        $i = $iComment;
+                    } else {
+                        $sToken = substr($address,$i,$iEnd - $i + 1);
+                        $i = $iEnd;
                     }
                 }
-                $address = trim(substr($address, $pos+1));
-                $j = strlen($address);
-                $pos = 0;
-                $name = '';
-                $addr = '';
-                if (!$grouplookup) {
-                    $addr_ar[] = $addr_structure;
+                // check the next token in case comments appear in the middle of email addresses
+                $prevToken = end($aTokens);
+                if (!in_array($prevToken,$aSpecials,true)) {
+                    if ($i+1<strlen($address) && !in_array($address{$i+1},$aSpecials,true)) {
+                        $iEnd = strpos($address,' ',$i+1);
+                        if ($iEnd) {
+                            $sNextToken = trim(substr($address,$i+1,$iEnd - $i -1));
+                            $i = $iEnd-1;
+                        } else {
+                            $sNextToken = trim(substr($address,$i+1));
+                            $i = $iCnt;
+                        }
+                        // remove the token
+                        array_pop($aTokens);
+                        // create token and add it again
+                        $sNewToken = $prevToken . $sNextToken;
+                        if($sNewToken) $aTokens[] = $sNewToken;
+                    }
                 }
+                $sToken = str_replace($aReplace, $aSpecials,$sToken);
+                if ($sToken) $aTokens[] = $sToken;
                 break;
-            case ':':  /* process the group addresses */
-                /* group marker */
-                $group = substr($address, 0, $pos);
-                $address = substr($address, $pos+1);
-                $result = $this->parseAddress($address, $ar, $addr_ar, $group, $lookup);
-                $addr_ar = $result[0];
-                $pos = $result[1];
-                $address = substr($address, $pos++);
-                $j = strlen($address);
-                $group = '';
-                break;
+            case ',':
+            case ':':
             case ';':
-                if ($group) {
-                    $address = substr($address, 0, $pos - 1);
-                }
-                ++$pos;
-                break;
             case ' ':
-                ++$pos;
+                $aTokens[] = $cChar;
                 break;
             default:
-                /* 
-                 * this happens in the folowing situations :
-                 * 1: unquoted personal name
-                 * 2: emailaddress without < and >
-                 * 3: unquoted personal name from compose that should be encoded.
-                 * if it's a personal name then an emailaddress should follow
-                 * the personal name may not have ',' inside it
-                 * If it's a emailaddress then the personal name is not set.
-                 * we should look for the delimiter ',' or a SPACE
-                 */
-                /* check for emailaddress */
-                $i_space = strpos($address,' ',$pos);
-                $i_del = strpos($address,',',$pos);
-                if ($i_space || $i_del) {
-                    if ($i_del) {
-                        $address_part = substr($address,$pos,$i_del-$pos);
-                    } else {
-                        $address_part = substr($address,$pos);
-                    }
-                    if ($i = strpos($address_part,'@')) {
-                        /* an email address is following */
-                        if (($i+$pos) < $i_space) {
-                            $addr_start = $pos;
-                            if ($i_space < $i_del && $i_del) {
-                                if ($i_space) {
-                                    $addr = substr($address,$pos,$i_space-$pos);
-                                    $pos = $i_space;
-                                } else {
-                                    $addr = substr($address,$pos);
-                                    $pos = $j;
-                                }
-                            } else {
-                                if ($i_del) {
-                                    $addr = substr($address,$pos,$i_del-$pos);
-                                    $pos = $i_del;
-                                } else {
-                                    $addr = substr($address,$pos);
-                                    $pos = $j;
-                                }
-                            }
-                        } else {
-                            if ($i_space) {
-                                $name .= substr($address,$pos,$i_space-$pos) .  ' ';
-                                $addr_start = $i_space+1;
-                                $pos = $i_space+1;
-                            } else {
-                                $addr = substr($address,$pos,$i_del-$pos);
-                                $addr_start = $pos;
-                                if ($i_del) {
-                                    $pos = $i_del;
-                                } else {
-                                    $pos = $j;
-                                }
-                            }
-                        }
-                    } else {
-                        /* email address without domain name, could be an alias */
-                        $addr_start = $pos;
-                        $addr = $address_part;
-                        $pos = strlen($address_part) + $pos;
-                    }
+                $iEnd = strpos($address,' ',$i+1);
+                if ($iEnd) {
+                    $sToken = trim(substr($address,$i,$iEnd - $i));
+                    $i = $iEnd-1;
                 } else {
-                    $addr = substr($address,$pos);
-                    $addr_start = $pos;
-                    $pos = $j;
+                    $sToken = trim(substr($address,$i));
+                    $i = $iCnt;
                 }
-                break;
+                if ($sToken) $aTokens[] = $sToken;
             }
+            ++$i;
         }
-        if (!$name && !$addr) {
-            $addr = substr($address, 0, $pos);
-        } else if (!$addr) {
-            $addr = trim(substr($address, $addr_start, $pos));
-        } else if ($name == '') {
-            $name = trim(substr($address, 0, $addr_start));
+        return $aTokens;
+    }
+
+    /**
+     * @param array $aStack
+     * @param array $aComment
+     * @param string $sEmail
+     * @param string $sGroup
+     * @return object AddressStructure object
+     */
+    function createAddressObject(&$aStack,&$aComment,&$sEmail,$sGroup='') {
+        //$aStack=explode(' ',implode('',$aStack));
+        if (!$sEmail) {
+            while (count($aStack) && !$sEmail) {
+                $sEmail = trim(array_pop($aStack));
+            }
         }
-        if (!$name && $comment) {
-            $name = $comment;
-        } else if ($name && $comment) {
-            $name = $name .' ('.$comment.')';
+        if (count($aStack)) {
+            $sPersonal = trim(implode('',$aStack));
+        } else {
+            $sPersonal = '';
+        }
+        if (!$sPersonal && count($aComment)) {
+            $sComment = trim(implode(' ',$aComment));
+            $sPersonal .= $sComment;
         }
-        $at = strpos($addr, '@');
-        $addr_structure = new AddressStructure();
-        $addr_structure->group = $group;
-        if ($at) {
-            $addr_structure->mailbox = trim(substr($addr, 0, $at));
-            $addr_structure->host = trim(substr($addr, $at+1));
+        $oAddr = new AddressStructure();
+        if ($sPersonal && substr($sPersonal,0,2) == '=?') {
+            $oAddr->personal = encodeHeader($sPersonal);
         } else {
-            /* if lookup function */
-            if ($lookup) {
-                $aAddr = call_user_func_array($lookup,array($addr));
-                if (isset($aAddr['email'])) {
-                    if (strpos($aAddr['email'],',')) {
-                        return $this->parseAddress($aAddr['email'], $ar, $addr_ar, $group, $host,$lookup);
-                    } else {
-                        $at = strpos($aAddr['email'], '@');
-                        $addr_structure->mailbox = substr($aAddr['email'], 0, $at);
-                        $addr_structure->host = substr($aAddr['email'], $at+1);
-                        if (isset($aAddr['name']) && $aAddr['name']) {
-                            $name = $aAddr['name'];
-                        } else {
-                            $name = $addr;
-                        }
+            $oAddr->personal = $sPersonal;
+        }
+ //       $oAddr->group = $sGroup;
+        $iPosAt = strpos($sEmail,'@');
+        if ($iPosAt) {
+           $oAddr->mailbox = substr($sEmail, 0, $iPosAt);
+           $oAddr->host = substr($sEmail, $iPosAt+1);
+        } else {
+           $oAddr->mailbox = $sEmail;
+           $oAddr->host = false;
+        }
+        $sEmail = '';
+        $aStack = $aComment = array();
+        return $oAddr;
+    }
+
+    /**
+     * recursive function for parsing address strings and storing them in an address stucture object.
+     *  personal name: encoded: =?charset?Q|B?string?=
+     *                 quoted:  "string"
+     *                 normal:  string
+     *  email        : <mailbox@host>
+     *               : mailbox@host
+     *  This function is also used for validating addresses returned from compose
+     *  That's also the reason that the function became a little bit huge
+     * @param string $address
+     * @param boolean $ar return array instead of only the first element
+     * @param array $addr_ar (obsolete) array with parsed addresses
+     * @param string $group (obsolete)
+     * @param string $host default domainname in case of addresses without a domainname
+     * @param string $lookup (since) callback function for lookup of address strings which are probably nicks (without @)
+     * @return mixed array with AddressStructure objects or only one address_structure object.
+     */
+    function parseAddress($address,$ar=false,$aAddress=array(),$sGroup='',$sHost='',$lookup=false) {
+        $aTokens = $this->getAddressTokens($address);
+        $sPersonal = $sEmail = $sGroup = '';
+        $aStack = $aComment = array();
+        foreach ($aTokens as $sToken) {
+            $cChar = $sToken{0};
+            switch ($cChar)
+            {
+            case '=':
+            case '"':
+            case ' ':
+                $aStack[] = $sToken;
+                break;
+            case '(':
+                $aComment[] = substr($sToken,1,-1);
+                break;
+            case ';':
+                if ($sGroup) {
+                    $aAddress[] = $this->createAddressObject($aStack,$aComment,$sEmail,$sGroup);
+                    $oAddr = end($aAddress);
+                    if(!$oAddr || ((isset($oAddr)) && !strlen($oAddr->mailbox) && !$oAddr->personal)) {
+                        $sEmail = $sGroup . ':;';
                     }
+                    $aAddress[] = $this->createAddressObject($aStack,$aComment,$sEmail,$sGroup);
+                    $sGroup = '';
+                    $aStack = $aComment = array();
+                    break;
                 }
+            case ',':
+                $aAddress[] = $this->createAddressObject($aStack,$aComment,$sEmail,$sGroup);
+                break;
+            case ':':
+                $sGroup = trim(implode(' ',$aStack));
+                $sGroup = preg_replace('/\s+/',' ',$sGroup);
+                $aStack = array();
+                break;
+            case '<':
+               $sEmail = trim(substr($sToken,1,-1));
+               break;
+            case '>':
+               /* skip */
+               break;
+            default: $aStack[] = $sToken; break;
             }
-            if (!$addr_structure->mailbox) {
-                $addr_structure->mailbox = trim($addr);
-                if ($host) {
-                    $addr_structure->host = $host;
+        }
+        /* now do the action again for the last address */
+        $aAddress[] = $this->createAddressObject($aStack,$aComment,$sEmail);
+        /* try to lookup the addresses in case of invalid email addresses */
+        $aProcessedAddress = array();
+        foreach ($aAddress as $oAddr) {
+          $aAddrBookAddress = array();
+          if (!$oAddr->host) {
+            $grouplookup = false;
+            if ($lookup) {
+                 $aAddr = call_user_func_array($lookup,array($oAddr->mailbox));
+                 if (isset($aAddr['email'])) {
+                     if (strpos($aAddr['email'],',')) {
+                         $grouplookup = true;
+                         $aAddrBookAddress = $this->parseAddress($aAddr['email'],true);
+                     } else {
+                         $iPosAt = strpos($aAddr['email'], '@');
+                         if ($iPosAt === FALSE) {
+                             $oAddr->mailbox = $aAddr['email'];
+                             $oAddr->host = FALSE;
+                         } else {
+                             $oAddr->mailbox = substr($aAddr['email'], 0, $iPosAt);
+                             $oAddr->host = substr($aAddr['email'], $iPosAt+1);
+                         } 
+                         if (isset($aAddr['name'])) {
+                             $oAddr->personal = $aAddr['name'];
+                         } else {
+                             $oAddr->personal = encodeHeader($sPersonal);
+                         }
+                     }
+                 }
+            }
+            if (!$grouplookup && !strlen($oAddr->mailbox)) {
+                $oAddr->mailbox = trim($sEmail);
+                if ($sHost && strlen($oAddr->mailbox)) {
+                    $oAddr->host = $sHost;
+                }
+            } else if (!$grouplookup && !$oAddr->host) {
+                if ($sHost && strlen($oAddr->mailbox)) {
+                    $oAddr->host = $sHost;
                 }
             }
+          }
+          if (!$aAddrBookAddress && strlen($oAddr->mailbox)) {
+              $aProcessedAddress[] = $oAddr;
+          } else {
+              $aProcessedAddress = array_merge($aProcessedAddress,$aAddrBookAddress);
+          }
         }
-        $name = trim($name);
-        if (!$is_encoded && !$group) {
-            $name = encodeHeader($name);
-        }
-        if ($group && $addr == '') { /* no addresses found in group */
-            $name = $group;
-            $addr_structure->personal = $name;
-            $addr_ar[] = $addr_structure;
-            return (array($addr_ar,$pos+1 ));
-        } elseif ($group) {
-            $addr_structure->personal = $name;
-            $addr_ar[] = $addr_structure;
-            return (array($addr_ar,$pos+1 ));
+        if ($ar) {
+            return $aProcessedAddress;
         } else {
-            $addr_structure->personal = $name;
-            if ($name || $addr) {
-                $addr_ar[] = $addr_structure;
-            }
+            if (isset($aProcessedAddress[0]))
+                return $aProcessedAddress[0];
+            else
+                return '';
         }
-        if ($ar) {
-            return ($addr_ar);
+    }
+
+    /**
+     * Normalise the different Priority headers into a uniform value,
+     * namely that of the X-Priority header (1, 3, 5). Supports:
+     * Priority, X-Priority, Importance.
+     * X-MS-Mail-Priority is not parsed because it always coincides
+     * with one of the other headers.
+     *
+     * NOTE: this is actually a duplicate from the code in
+     * functions/imap_messages:parseFetch().
+     * I'm not sure if it's ok here to call
+     * that function?
+     * @param string $sValue literal priority name
+     * @return integer
+     */
+    function parsePriority($sValue) {
+        // don't use function call inside array_shift.
+        $aValue = preg_split('/\s/',trim($sValue));
+        $value = strtolower(array_shift($aValue));
+
+        if ( is_numeric($value) ) {
+            return $value;
         }
-        return ($addr_ar[0]);
+        if ( $value == 'urgent' || $value == 'high' ) {
+            return 1;
+        } elseif ( $value == 'non-urgent' || $value == 'low' ) {
+            return 5;
+        }
+        // default is normal priority
+        return 3;
     }
 
+    /**
+     * @param string $value content type header
+     */
     function parseContentType($value) {
         $pos = strpos($value, ';');
         $props = '';
@@ -551,6 +713,52 @@ class Rfc822Header {
         $this->content_type = $content_type;
     }
 
+    /**
+     * RFC2184
+     * @param array $aParameters
+     * @return array
+     */
+    function processParameters($aParameters) {
+        $aResults = array();
+        $aCharset = array();
+        // handle multiline parameters
+        foreach($aParameters as $key => $value) {
+            if ($iPos = strpos($key,'*')) {
+                $sKey = substr($key,0,$iPos);
+                if (!isset($aResults[$sKey])) {
+                    $aResults[$sKey] = $value;
+                    if (substr($key,-1) == '*') { // parameter contains language/charset info
+                        $aCharset[] = $sKey;
+                    }
+                } else {
+                    $aResults[$sKey] .= $value;
+                }
+            } else {
+                $aResults[$key] = $value;
+            }
+        }
+        foreach ($aCharset as $key) {
+            $value = $aResults[$key];
+            // extract the charset & language
+            $charset = substr($value,0,strpos($value,"'"));
+            $value = substr($value,strlen($charset)+1);
+            $language = substr($value,0,strpos($value,"'"));
+            $value = substr($value,strlen($charset)+1);
+            /* FIXME: What's the status of charset decode with language information ????
+             * Maybe language information contains only ascii text and charset_decode() 
+             * only runs sm_encode_html_special_chars() on it. If it contains 8bit information, you 
+             * get html encoded text in charset used by selected translation.
+             */
+            $value = charset_decode($charset,$value);
+            $aResults[$key] = $value;
+        }
+        return $aResults;
+    }
+
+    /**
+     * @param string $value
+     * @return array
+     */
     function parseProperties($value) {
         $propArray = explode(';', $value);
         $propResultArray = array();
@@ -560,15 +768,19 @@ class Rfc822Header {
             if ($pos > 0)  {
                 $key = trim(substr($prop, 0, $pos));
                 $val = trim(substr($prop, $pos+1));
-                if ($val{0} == '"') {
+                if (strlen($val) > 0 && $val{0} == '"') {
                     $val = substr($val, 1, -1);
                 }
                 $propResultArray[$key] = $val;
             }
         }
-        return $propResultArray;
+        return $this->processParameters($propResultArray);
     }
 
+    /**
+     * Fills disposition object in rfc822Header object
+     * @param string $value
+     */
     function parseDisposition($value) {
         $pos = strpos($value, ';');
         $props = '';
@@ -584,6 +796,11 @@ class Rfc822Header {
         $this->disposition = $disp;
     }
 
+    /**
+     * Fills mlist array keys in rfc822Header object 
+     * @param string $field
+     * @param string $value
+     */
     function mlist($field, $value) {
         $res_a = array();
         $value_a = explode(',', $value);
@@ -601,19 +818,90 @@ class Rfc822Header {
         $this->mlist[$field] = $res_a;
     }
 
-    /*
-     * function to get the addres strings out of the header.
-     * Arguments: string or array of strings !
+    /**
+     * Parses the X-Spam-Status or X-Spam-Score header
+     * @param string $value
+     */
+    function parseSpamStatus($value) {
+        // Header value looks like this:
+        // No, score=1.5 required=5.0 tests=MSGID_FROM_MTA_ID,NO_REAL_NAME,UPPERCASE_25_50 autolearn=disabled version=3.1.0-gr0
+        // Update circa 2018, this header can also be simply:
+        // No, score=1.5
+        // So we make the rest of the line optional (there are likely other permutations, so
+        // each element is made optional except the first two... maybe even that's not flexible enough)
+        //
+        // Also now allow parsing of X-Spam-Score header, whose value is just a float
+
+        $spam_status = array();
+
+        if (preg_match ('/^(?:(No|Yes),\s+score=)?(-?\d+\.\d+)(?:\s+required=(-?\d+\.\d+))?(?:\s+tests=(.*?))?(?:\s+autolearn=(.*?))?(?:\s+version=(.+?))?$/i', $value, $matches)) {
+
+            // full header
+            $spam_status['bad_format'] = 0;
+            $spam_status['value'] = $matches[0];
+
+            // is_spam
+            if (!empty($matches[1])) {
+                if (strtolower($matches[1]) == 'yes')
+                    $spam_status['is_spam'] = true;
+                else
+                    $spam_status['is_spam'] = false;
+            }
+
+            // score
+            if (!empty($matches[2]))
+                $spam_status['score'] = $matches[2];
+
+            // required
+            if (!empty($matches[3]))
+                $spam_status['required'] = $matches[3];
+
+            // tests
+            if (isset($matches[4])) {
+                $tests = array();
+                $tests = explode(',', $matches[4]);
+                foreach ($tests as $test) {
+                    $spam_status['tests'][] = trim($test);
+                }
+            }
+
+            // autolearn
+            if (isset($matches[5]))
+                $spam_status['autolearn'] = $matches[5];
+
+            // version
+            if (isset($matches[6]))
+                $spam_status['version'] = $matches[6];
+
+        } else {
+            $spam_status['bad_format'] = 1;
+            $spam_status['value'] = $value;
+        }
+        return $spam_status;
+    }
+
+    /**
+     * function to get the address strings out of the header.
      * example1: header->getAddr_s('to').
      * example2: header->getAddr_s(array('to', 'cc', 'bcc'))
+     * @param mixed $arr string or array of strings
+     * @param string $separator
+     * @param boolean $encoded (since 1.4.0) return encoded or plain text addresses
+     * @param boolean $unconditionally_quote (since 1.4.21/1.5.2) When TRUE, always
+     *                                                      quote the personal part,
+     *                                                      whether or not it is
+     *                                                      encoded, otherwise quoting
+     *                                                      is only added if the
+     *                                                      personal part is not encoded
+     * @return string
      */
-    function getAddr_s($arr, $separator = ',',$encoded=false) {
+    function getAddr_s($arr, $separator = ', ', $encoded=false, $unconditionally_quote=FALSE) {
         $s = '';
 
         if (is_array($arr)) {
             foreach($arr as $arg) {
-                if ($this->getAddr_s($arg, $separator, $encoded)) {
-                    $s .= $separator . $result;
+                if ($this->getAddr_s($arg, $separator, $encoded, $unconditionally_quote)) {
+                    $s .= $separator;
                 }
             }
             $s = ($s ? substr($s, 2) : $s);
@@ -623,9 +911,9 @@ class Rfc822Header {
                 foreach ($addr as $addr_o) {
                     if (is_object($addr_o)) {
                         if ($encoded) {
-                            $s .= $addr_o->getEncodedAddress() . $separator;
+                            $s .= $addr_o->getEncodedAddress($unconditionally_quote) . $separator;
                         } else {
-                            $s .= $addr_o->getAddress() . $separator;
+                            $s .= $addr_o->getAddress(TRUE, FALSE, $unconditionally_quote) . $separator;
                         }
                     }
                 }
@@ -633,9 +921,9 @@ class Rfc822Header {
             } else {
                 if (is_object($addr)) {
                     if ($encoded) {
-                        $s .= $addr->getEncodedAddress();
+                        $s .= $addr->getEncodedAddress($unconditionally_quote);
                     } else {
-                        $s .= $addr->getAddress();
+                        $s .= $addr->getAddress(TRUE, FALSE, $unconditionally_quote);
                     }
                 }
             }
@@ -643,6 +931,13 @@ class Rfc822Header {
         return $s;
     }
 
+    /**
+     * function to get the array of addresses out of the header.
+     * @param mixed $arg string or array of strings
+     * @param array $excl_arr array of excluded email addresses
+     * @param array $arr array of added email addresses
+     * @return array
+     */
     function getAddr_a($arg, $excl_arr = array(), $arr = array()) {
         if (is_array($arg)) {
             foreach($arg as $argument) {
@@ -677,32 +972,80 @@ class Rfc822Header {
         }
         return $arr;
     }
-    
+
+    /**
+//FIXME: This needs some documentation (inside the function too)!  Don't code w/out comments!
+     * Looking at the code years after it was written,
+     * this is my (Paul) best guess as to what this
+     * function does (note that docs previously claimed
+     * that this function returns boolean or an array,
+     * but it no longer appears to return an array - an
+     * integer instead):
+     *
+     * Inspects the TO and CC headers of the message
+     * represented by this object, looking for the
+     * address(es) given by $address
+     *
+     * If $address is a string:
+     *    Serves as a test (returns boolean) as to
+     *    whether or not the given address is found
+     *    anywhere in the TO or CC headers
+     *
+     * If $address is an array:
+     *    Looks through this list of addresses and
+     *    returns the array index (an integer even
+     *    if the array is given with keys of a
+     *    different type) of the first matching
+     *    $address found in this message's
+     *    TO or CC headers, unless there is an exact
+     *    match (meaning that the "personal
+     *    information" in addition to the email
+     *    address also matches), in which case that
+     *    index (the first one found) is returned
+     *
+     * @param mixed $address Address(es) to search for in this
+     *                       message's TO and CC headers - please
+     *                       see above how the format of this
+     *                       argument affects the return value
+     *                       of this function
+     * @param boolean $recurs FOR INTERNAL USE ONLY
+     *
+     * @return mixed Boolean when $address is a scalar,
+     *               indicating whether or not the address
+     *               was found in the TO or CC headers.
+     *               An integer when $address is an array,
+     *               containing the index of the value in
+     *               that array that was found in the TO
+     *               or CC headers, or boolean FALSE if
+     *               there were no matches at all
+     *
+     * @since 1.3.2
+     */
     function findAddress($address, $recurs = false) {
         $result = false;
         if (is_array($address)) {
             $i=0;
             foreach($address as $argument) {
                 $match = $this->findAddress($argument, true);
-                $last = end($match);
-                if ($match[1]) {
+                if ($match[1]) { // this indicates when the personal information matched
                     return $i;
                 } else {
-                    if (count($match[0]) && !$result) {
+                    if (count($match[0]) && $result === FALSE) {
                         $result = $i;
                     }
                 }
-                ++$i;        
+                ++$i;
             }
         } else {
             if (!is_array($this->cc)) $this->cc = array();
+            if (!is_array($this->to)) $this->to = array();
             $srch_addr = $this->parseAddress($address);
             $results = array();
             foreach ($this->to as $to) {
-                if ($to->host == $srch_addr->host) {
-                    if ($to->mailbox == $srch_addr->mailbox) {
+                if (strtolower($to->host) == strtolower($srch_addr->host)) {
+                    if (strtolower($to->mailbox) == strtolower($srch_addr->mailbox)) {
                         $results[] = $srch_addr;
-                        if ($to->personal == $srch_addr->personal) {
+                        if (strtolower($to->personal) == strtolower($srch_addr->personal)) {
                             if ($recurs) {
                                 return array($results, true);
                             } else {
@@ -712,11 +1055,11 @@ class Rfc822Header {
                     }
                 }
             }
-             foreach ($this->cc as $cc) {
-                if ($cc->host == $srch_addr->host) {
-                    if ($cc->mailbox == $srch_addr->mailbox) {
+            foreach ($this->cc as $cc) {
+                if (strtolower($cc->host) == strtolower($srch_addr->host)) {
+                    if (strtolower($cc->mailbox) == strtolower($srch_addr->mailbox)) {
                         $results[] = $srch_addr;
-                        if ($cc->personal == $srch_addr->personal) {
+                        if (strtolower($cc->personal) == strtolower($srch_addr->personal)) {
                             if ($recurs) {
                                 return array($results, true);
                             } else {
@@ -728,21 +1071,25 @@ class Rfc822Header {
             }
             if ($recurs) {
                 return array($results, false);
-            } elseif (count($result)) {
+            } elseif (count($results)) {
                 return true;
             } else {
                 return false;
-            }        
+            }
         }
         //exit;
         return $result;
     }
 
+    /**
+     * @param string $type0 media type
+     * @param string $type1 media subtype
+     * @return array media properties
+     * @todo check use of media type arguments
+     */
     function getContentType($type0, $type1) {
         $type0 = $this->content_type->type0;
         $type1 = $this->content_type->type1;
         return $this->content_type->properties;
     }
 }
-
-?>