Added Net_LDAP2 to extlib, and add a skeleton LDAP plugin

1 files changed, 922 insertions, 0 deletions

diff --git a/extlib/Net/LDAP2/LDIF.php b/extlib/Net/LDAP2/LDIF.php
new file mode 100644
index 000000000..34f3e75dd
--- /dev/null
+++ b/extlib/Net/LDAP2/LDIF.php
@@ -0,0 +1,922 @@
+<?php
+/* vim: set expandtab tabstop=4 shiftwidth=4: */
+/**
+* File containing the Net_LDAP2_LDIF interface class.
+*
+* PHP version 5
+*
+* @category  Net
+* @package   Net_LDAP2
+* @author    Benedikt Hallinger <beni@php.net>
+* @copyright 2009 Benedikt Hallinger
+* @license   http://www.gnu.org/licenses/lgpl-3.0.txt LGPLv3
+* @version   SVN: $Id: LDIF.php 286718 2009-08-03 07:30:49Z beni $
+* @link      http://pear.php.net/package/Net_LDAP2/
+*/
+
+/**
+* Includes
+*/
+require_once 'PEAR.php';
+require_once 'Net/LDAP2.php';
+require_once 'Net/LDAP2/Entry.php';
+require_once 'Net/LDAP2/Util.php';
+
+/**
+* LDIF capabilitys for Net_LDAP2, closely taken from PERLs Net::LDAP
+*
+* It provides a means to convert between Net_LDAP2_Entry objects and LDAP entries
+* represented in LDIF format files. Reading and writing are supported and may
+* manipulate single entries or lists of entries.
+*
+* Usage example:
+* <code>
+* // Read and parse an ldif-file into Net_LDAP2_Entry objects
+* // and print out the DNs. Store the entries for later use.
+* require 'Net/LDAP2/LDIF.php';
+* $options = array(
+*       'onerror' => 'die'
+* );
+* $entries = array();
+* $ldif = new Net_LDAP2_LDIF('test.ldif', 'r', $options);
+* do {
+*       $entry = $ldif->read_entry();
+*       $dn    = $entry->dn();
+*       echo " done building entry: $dn\n";
+*       array_push($entries, $entry);
+* } while (!$ldif->eof());
+* $ldif->done();
+*
+*
+* // write those entries to another file
+* $ldif = new Net_LDAP2_LDIF('test.out.ldif', 'w', $options);
+* $ldif->write_entry($entries);
+* $ldif->done();
+* </code>
+*
+* @category Net
+* @package  Net_LDAP2
+* @author   Benedikt Hallinger <beni@php.net>
+* @license  http://www.gnu.org/copyleft/lesser.html LGPL
+* @link     http://pear.php.net/package/Net_LDAP22/
+* @see      http://www.ietf.org/rfc/rfc2849.txt
+* @todo     Error handling should be PEARified
+* @todo     LDAPv3 controls are not implemented yet
+*/
+class Net_LDAP2_LDIF extends PEAR
+{
+    /**
+    * Options
+    *
+    * @access protected
+    * @var array
+    */
+    protected $_options = array('encode'    => 'base64',
+                                'onerror'   => null,
+                                'change'    => 0,
+                                'lowercase' => 0,
+                                'sort'      => 0,
+                                'version'   => null,
+                                'wrap'      => 78,
+                                'raw'       => ''
+                               );
+
+    /**
+    * Errorcache
+    *
+    * @access protected
+    * @var array
+    */
+    protected $_error = array('error' => null,
+                              'line'  => 0
+                             );
+
+    /**
+    * Filehandle for read/write
+    *
+    * @access protected
+    * @var array
+    */
+    protected $_FH = null;
+
+    /**
+    * Says, if we opened the filehandle ourselves
+    *
+    * @access protected
+    * @var array
+    */
+    protected $_FH_opened = false;
+
+    /**
+    * Linecounter for input file handle
+    *
+    * @access protected
+    * @var array
+    */
+    protected $_input_line = 0;
+
+    /**
+    * counter for processed entries
+    *
+    * @access protected
+    * @var int
+    */
+    protected $_entrynum = 0;
+
+    /**
+    * Mode we are working in
+    *
+    * Either 'r', 'a' or 'w'
+    *
+    * @access protected
+    * @var string
+    */
+    protected $_mode = false;
+
+    /**
+    * Tells, if the LDIF version string was already written
+    *
+    * @access protected
+    * @var boolean
+    */
+    protected $_version_written = false;
+
+    /**
+    * Cache for lines that have build the current entry
+    *
+    * @access protected
+    * @var boolean
+    */
+    protected $_lines_cur = array();
+
+    /**
+    * Cache for lines that will build the next entry
+    *
+    * @access protected
+    * @var boolean
+    */
+    protected $_lines_next = array();
+
+    /**
+    * Open LDIF file for reading or for writing
+    *
+    * new (FILE):
+    * Open the file read-only. FILE may be the name of a file
+    * or an already open filehandle.
+    * If the file doesn't exist, it will be created if in write mode.
+    *
+    * new (FILE, MODE, OPTIONS):
+    *     Open the file with the given MODE (see PHPs fopen()), eg "w" or "a".
+    *     FILE may be the name of a file or an already open filehandle.
+    *     PERLs Net_LDAP2 "FILE|" mode does not work curently.
+    *
+    *     OPTIONS is an associative array and may contain:
+    *       encode => 'none' | 'canonical' | 'base64'
+    *         Some DN values in LDIF cannot be written verbatim and have to be encoded in some way:
+    *         'none'       No encoding.
+    *         'canonical'  See "canonical_dn()" in Net::LDAP::Util.
+    *         'base64'     Use base64. (default, this differs from the Perl interface.
+    *                                   The perl default is "none"!)
+    *
+    *       onerror => 'die' | 'warn' | NULL
+    *         Specify what happens when an error is detected.
+    *         'die'  Net_LDAP2_LDIF will croak with an appropriate message.
+    *         'warn' Net_LDAP2_LDIF will warn (echo) with an appropriate message.
+    *         NULL   Net_LDAP2_LDIF will not warn (default), use error().
+    *
+    *       change => 1
+    *         Write entry changes to the LDIF file instead of the entries itself. I.e. write LDAP
+    *         operations acting on the entries to the file instead of the entries contents.
+    *         This writes the changes usually carried out by an update() to the LDIF file.
+    *
+    *       lowercase => 1
+    *         Convert attribute names to lowercase when writing.
+    *
+    *       sort => 1
+    *         Sort attribute names when writing entries according to the rule:
+    *         objectclass first then all other attributes alphabetically sorted by attribute name
+    *
+    *       version => '1'
+    *         Set the LDIF version to write to the resulting LDIF file.
+    *         According to RFC 2849 currently the only legal value for this option is 1.
+    *         When this option is set Net_LDAP2_LDIF tries to adhere more strictly to
+    *         the LDIF specification in RFC2489 in a few places.
+    *         The default is NULL meaning no version information is written to the LDIF file.
+    *
+    *       wrap => 78
+    *         Number of columns where output line wrapping shall occur.
+    *         Default is 78. Setting it to 40 or lower inhibits wrapping.
+    *
+    *       raw => REGEX
+    *         Use REGEX to denote the names of attributes that are to be
+    *         considered binary in search results if writing entries.
+    *         Example: raw => "/(?i:^jpegPhoto|;binary)/i"
+    *
+    * @param string|ressource $file    Filename or filehandle
+    * @param string           $mode    Mode to open filename
+    * @param array            $options Options like described above
+    */
+    public function __construct($file, $mode = 'r', $options = array())
+    {
+        $this->PEAR('Net_LDAP2_Error'); // default error class
+
+        // First, parse options
+        // todo: maybe implement further checks on possible values
+        foreach ($options as $option => $value) {
+            if (!array_key_exists($option, $this->_options)) {
+                $this->dropError('Net_LDAP2_LDIF error: option '.$option.' not known!');
+                return;
+            } else {
+                $this->_options[$option] = strtolower($value);
+            }
+        }
+
+        // setup LDIF class
+        $this->version($this->_options['version']);
+
+        // setup file mode
+        if (!preg_match('/^[rwa]\+?$/', $mode)) {
+            $this->dropError('Net_LDAP2_LDIF error: file mode '.$mode.' not supported!');
+        } else {
+            $this->_mode = $mode;
+
+            // setup filehandle
+            if (is_resource($file)) {
+                // TODO: checks on mode possible?
+                $this->_FH =& $file;
+            } else {
+                $imode = substr($this->_mode, 0, 1);
+                if ($imode == 'r') {
+                    if (!file_exists($file)) {
+                        $this->dropError('Unable to open '.$file.' for read: file not found');
+                        $this->_mode = false;
+                    }
+                    if (!is_readable($file)) {
+                        $this->dropError('Unable to open '.$file.' for read: permission denied');
+                        $this->_mode = false;
+                    }
+                }
+
+                if (($imode == 'w' || $imode == 'a')) {
+                    if (file_exists($file)) {
+                        if (!is_writable($file)) {
+                            $this->dropError('Unable to open '.$file.' for write: permission denied');
+                            $this->_mode = false;
+                        }
+                    } else {
+                        if (!@touch($file)) {
+                            $this->dropError('Unable to create '.$file.' for write: permission denied');
+                            $this->_mode = false;
+                        }
+                    }
+                }
+
+                if ($this->_mode) {
+                    $this->_FH = @fopen($file, $this->_mode);
+                    if (false === $this->_FH) {
+                        // Fallback; should never be reached if tests above are good enough!
+                        $this->dropError('Net_LDAP2_LDIF error: Could not open file '.$file);
+                    } else {
+                        $this->_FH_opened = true;
+                    }
+                }
+            }
+        }
+    }
+
+    /**
+    * Read one entry from the file and return it as a Net::LDAP::Entry object.
+    *
+    * @return Net_LDAP2_Entry
+    */
+    public function read_entry()
+    {
+        // read fresh lines, set them as current lines and create the entry
+        $attrs = $this->next_lines(true);
+        if (count($attrs) > 0) {
+            $this->_lines_cur = $attrs;
+        }
+        return $this->current_entry();
+    }
+
+    /**
+    * Returns true when the end of the file is reached.
+    *
+    * @return boolean
+    */
+    public function eof()
+    {
+        return feof($this->_FH);
+    }
+
+    /**
+    * Write the entry or entries to the LDIF file.
+    *
+    * If you want to build an LDIF file containing several entries AND
+    * you want to call write_entry() several times, you must open the filehandle
+    * in append mode ("a"), otherwise you will always get the last entry only.
+    *
+    * @param Net_LDAP2_Entry|array $entries Entry or array of entries
+    *
+    * @return void
+    * @todo implement operations on whole entries (adding a whole entry)
+    */
+    public function write_entry($entries)
+    {
+        if (!is_array($entries)) {
+            $entries = array($entries);
+        }
+
+        foreach ($entries as $entry) {
+            $this->_entrynum++;
+            if (!$entry instanceof Net_LDAP2_Entry) {
+                $this->dropError('Net_LDAP2_LDIF error: entry '.$this->_entrynum.' is not an Net_LDAP2_Entry object');
+            } else {
+                if ($this->_options['change']) {
+                    // LDIF change mode
+                    // fetch change information from entry
+                    $entry_attrs_changes = $entry->getChanges();
+                    $num_of_changes      = count($entry_attrs_changes['add'])
+                                           + count($entry_attrs_changes['replace'])
+                                           + count($entry_attrs_changes['delete']);
+
+                    $is_changed = ($num_of_changes > 0 || $entry->willBeDeleted() || $entry->willBeMoved());
+
+                    // write version if not done yet
+                    // also write DN of entry
+                    if ($is_changed) {
+                        if (!$this->_version_written) {
+                            $this->write_version();
+                        }
+                        $this->writeDN($entry->currentDN());
+                    }
+
+                    // process changes
+                    // TODO: consider DN add!
+                    if ($entry->willBeDeleted()) {
+                        $this->writeLine("changetype: delete".PHP_EOL);
+                    } elseif ($entry->willBeMoved()) {
+                        $this->writeLine("changetype: modrdn".PHP_EOL);
+                        $olddn     = Net_LDAP2_Util::ldap_explode_dn($entry->currentDN(), array('casefold' => 'none')); // maybe gives a bug if using multivalued RDNs
+                        $oldrdn    = array_shift($olddn);
+                        $oldparent = implode(',', $olddn);
+                        $newdn     = Net_LDAP2_Util::ldap_explode_dn($entry->dn(), array('casefold' => 'none')); // maybe gives a bug if using multivalued RDNs
+                        $rdn       = array_shift($newdn);
+                        $parent    = implode(',', $newdn);
+                        $this->writeLine("newrdn: ".$rdn.PHP_EOL);
+                        $this->writeLine("deleteoldrdn: 1".PHP_EOL);
+                        if ($parent !== $oldparent) {
+                            $this->writeLine("newsuperior: ".$parent.PHP_EOL);
+                        }
+                        // TODO: What if the entry has attribute changes as well?
+                        //       I think we should check for that and make a dummy
+                        //       entry with the changes that is written to the LDIF file
+                    } elseif ($num_of_changes > 0) {
+                        // write attribute change data
+                        $this->writeLine("changetype: modify".PHP_EOL);
+                        foreach ($entry_attrs_changes as $changetype => $entry_attrs) {
+                            foreach ($entry_attrs as $attr_name => $attr_values) {
+                                $this->writeLine("$changetype: $attr_name".PHP_EOL);
+                                if ($attr_values !== null) $this->writeAttribute($attr_name, $attr_values, $changetype);
+                                $this->writeLine("-".PHP_EOL);
+                            }
+                        }
+                    }
+
+                    // finish this entrys data if we had changes
+                    if ($is_changed) {
+                        $this->finishEntry();
+                    }
+                } else {
+                    // LDIF-content mode
+                    // fetch attributes for further processing
+                    $entry_attrs = $entry->getValues();
+
+                    // sort and put objectclass-attrs to first position
+                    if ($this->_options['sort']) {
+                        ksort($entry_attrs);
+                        if (array_key_exists('objectclass', $entry_attrs)) {
+                            $oc = $entry_attrs['objectclass'];
+                            unset($entry_attrs['objectclass']);
+                            $entry_attrs = array_merge(array('objectclass' => $oc), $entry_attrs);
+                        }
+                    }
+
+                    // write data
+                    if (!$this->_version_written) {
+                        $this->write_version();
+                    }
+                    $this->writeDN($entry->dn());
+                    foreach ($entry_attrs as $attr_name => $attr_values) {
+                        $this->writeAttribute($attr_name, $attr_values);
+                    }
+                    $this->finishEntry();
+                }
+            }
+        }
+    }
+
+    /**
+    * Write version to LDIF
+    *
+    * If the object's version is defined, this method allows to explicitely write the version before an entry is written.
+    * If not called explicitely, it gets called automatically when writing the first entry.
+    *
+    * @return void
+    */
+    public function write_version()
+    {
+        $this->_version_written = true;
+        if (!is_null($this->version())) {
+            return $this->writeLine('version: '.$this->version().PHP_EOL, 'Net_LDAP2_LDIF error: unable to write version');
+        }
+    }
+
+    /**
+    * Get or set LDIF version
+    *
+    * If called without arguments it returns the version of the LDIF file or NULL if no version has been set.
+    * If called with an argument it sets the LDIF version to VERSION.
+    * According to RFC 2849 currently the only legal value for VERSION is 1.
+    *
+    * @param int $version (optional) LDIF version to set
+    *
+    * @return int
+    */
+    public function version($version = null)
+    {
+        if ($version !== null) {
+            if ($version != 1) {
+                $this->dropError('Net_LDAP2_LDIF error: illegal LDIF version set');
+            } else {
+                $this->_options['version'] = $version;
+            }
+        }
+        return $this->_options['version'];
+    }
+
+    /**
+    * Returns the file handle the Net_LDAP2_LDIF object reads from or writes to.
+    *
+    * You can, for example, use this to fetch the content of the LDIF file yourself
+    *
+    * @return null|resource
+    */
+    public function &handle()
+    {
+        if (!is_resource($this->_FH)) {
+            $this->dropError('Net_LDAP2_LDIF error: invalid file resource');
+            $null = null;
+            return $null;
+        } else {
+            return $this->_FH;
+        }
+    }
+
+    /**
+    * Clean up
+    *
+    * This method signals that the LDIF object is no longer needed.
+    * You can use this to free up some memory and close the file handle.
+    * The file handle is only closed, if it was opened from Net_LDAP2_LDIF.
+    *
+    * @return void
+    */
+    public function done()
+    {
+        // close FH if we opened it
+        if ($this->_FH_opened) {
+            fclose($this->handle());
+        }
+
+        // free variables
+        foreach (get_object_vars($this) as $name => $value) {
+            unset($this->$name);
+        }
+    }
+
+    /**
+    * Returns last error message if error was found.
+    *
+    * Example:
+    * <code>
+    *  $ldif->someAction();
+    *  if ($ldif->error()) {
+    *     echo "Error: ".$ldif->error()." at input line: ".$ldif->error_lines();
+    *  }
+    * </code>
+    *
+    * @param boolean $as_string If set to true, only the message is returned
+    *
+    * @return false|Net_LDAP2_Error
+    */
+    public function error($as_string = false)
+    {
+        if (Net_LDAP2::isError($this->_error['error'])) {
+            return ($as_string)? $this->_error['error']->getMessage() : $this->_error['error'];
+        } else {
+            return false;
+        }
+    }
+
+    /**
+    * Returns lines that resulted in error.
+    *
+    * Perl returns an array of faulty lines in list context,
+    * but we always just return an int because of PHPs language.
+    *
+    * @return int
+    */
+    public function error_lines()
+    {
+        return $this->_error['line'];
+    }
+
+    /**
+    * Returns the current Net::LDAP::Entry object.
+    *
+    * @return Net_LDAP2_Entry|false
+    */
+    public function current_entry()
+    {
+        return $this->parseLines($this->current_lines());
+    }
+
+    /**
+    * Parse LDIF lines of one entry into an Net_LDAP2_Entry object
+    *
+    * @param array $lines LDIF lines for one entry
+    *
+    * @return Net_LDAP2_Entry|false Net_LDAP2_Entry object for those lines
+    * @todo what about file inclusions and urls? "jpegphoto:< file:///usr/local/directory/photos/fiona.jpg"
+    */
+    public function parseLines($lines)
+    {
+        // parse lines into an array of attributes and build the entry
+        $attributes = array();
+        $dn = false;
+        foreach ($lines as $line) {
+            if (preg_match('/^(\w+)(:|::|:<)\s(.+)$/', $line, $matches)) {
+                $attr  =& $matches[1];
+                $delim =& $matches[2];
+                $data  =& $matches[3];
+
+                if ($delim == ':') {
+                    // normal data
+                    $attributes[$attr][] = $data;
+                } elseif ($delim == '::') {
+                    // base64 data
+                    $attributes[$attr][] = base64_decode($data);
+                } elseif ($delim == ':<') {
+                    // file inclusion
+                    // TODO: Is this the job of the LDAP-client or the server?
+                    $this->dropError('File inclusions are currently not supported');
+                    //$attributes[$attr][] = ...;
+                } else {
+                    // since the pattern above, the delimeter cannot be something else.
+                    $this->dropError('Net_LDAP2_LDIF parsing error: invalid syntax at parsing entry line: '.$line);
+                    continue;
+                }
+
+                if (strtolower($attr) == 'dn') {
+                    // DN line detected
+                    $dn = $attributes[$attr][0];  // save possibly decoded DN
+                    unset($attributes[$attr]);    // remove wrongly added "dn: " attribute
+                }
+            } else {
+                // line not in "attr: value" format -> ignore
+                // maybe we should rise an error here, but this should be covered by
+                // next_lines() already. A problem arises, if users try to feed data of
+                // several entries to this method - the resulting entry will
+                // get wrong attributes. However, this is already mentioned in the
+                // methods documentation above.
+            }
+        }
+
+        if (false === $dn) {
+            $this->dropError('Net_LDAP2_LDIF parsing error: unable to detect DN for entry');
+            return false;
+        } else {
+            $newentry = Net_LDAP2_Entry::createFresh($dn, $attributes);
+            return $newentry;
+        }
+    }
+
+    /**
+    * Returns the lines that generated the current Net::LDAP::Entry object.
+    *
+    * Note that this returns an empty array if no lines have been read so far.
+    *
+    * @return array Array of lines
+    */
+    public function current_lines()
+    {
+        return $this->_lines_cur;
+    }
+
+    /**
+    * Returns the lines that will generate the next Net::LDAP::Entry object.
+    *
+    * If you set $force to TRUE then you can iterate over the lines that build
+    * up entries manually. Otherwise, iterating is done using {@link read_entry()}.
+    * Force will move the file pointer forward, thus returning the next entries lines.
+    *
+    * Wrapped lines will be unwrapped. Comments are stripped.
+    *
+    * @param boolean $force Set this to true if you want to iterate over the lines manually
+    *
+    * @return array
+    */
+    public function next_lines($force = false)
+    {
+        // if we already have those lines, just return them, otherwise read
+        if (count($this->_lines_next) == 0 || $force) {
+            $this->_lines_next = array(); // empty in case something was left (if used $force)
+            $entry_done        = false;
+            $fh                = &$this->handle();
+            $commentmode       = false; // if we are in an comment, for wrapping purposes
+            $datalines_read    = 0;     // how many lines with data we have read
+
+            while (!$entry_done && !$this->eof()) {
+                $this->_input_line++;
+                // Read line. Remove line endings, we want only data;
+                // this is okay since ending spaces should be encoded
+                $data = rtrim(fgets($fh));
+                if ($data === false) {
+                    // error only, if EOF not reached after fgets() call
+                    if (!$this->eof()) {
+                        $this->dropError('Net_LDAP2_LDIF error: error reading from file at input line '.$this->_input_line, $this->_input_line);
+                    }
+                    break;
+                } else {
+                    if (count($this->_lines_next) > 0 && preg_match('/^$/', $data)) {
+                        // Entry is finished if we have an empty line after we had data
+                        $entry_done = true;
+
+                        // Look ahead if the next EOF is nearby. Comments and empty
+                        // lines at the file end may cause problems otherwise
+                        $current_pos = ftell($fh);
+                        $data        = fgets($fh);
+                        while (!feof($fh)) {
+                            if (preg_match('/^\s*$/', $data) || preg_match('/^#/', $data)) {
+                                // only empty lines or comments, continue to seek
+                                // TODO: Known bug: Wrappings for comments are okay but are treaten as
+                                //       error, since we do not honor comment mode here.
+                                //       This should be a very theoretically case, however
+                                //       i am willing to fix this if really necessary.
+                                $this->_input_line++;
+                                $current_pos = ftell($fh);
+                                $data        = fgets($fh);
+                            } else {
+                                // Data found if non emtpy line and not a comment!!
+                                // Rewind to position prior last read and stop lookahead
+                                fseek($fh, $current_pos);
+                                break;
+                            }
+                        }
+                        // now we have either the file pointer at the beginning of
+                        // a new data position or at the end of file causing feof() to return true
+
+                    } else {
+                        // build lines
+                        if (preg_match('/^version:\s(.+)$/', $data, $match)) {
+                            // version statement, set version
+                            $this->version($match[1]);
+                        } elseif (preg_match('/^\w+::?\s.+$/', $data)) {
+                            // normal attribute: add line
+                            $commentmode         = false;
+                            $this->_lines_next[] = trim($data);
+                            $datalines_read++;
+                        } elseif (preg_match('/^\s(.+)$/', $data, $matches)) {
+                            // wrapped data: unwrap if not in comment mode
+                            if (!$commentmode) {
+                                if ($datalines_read == 0) {
+                                    // first line of entry: wrapped data is illegal
+                                    $this->dropError('Net_LDAP2_LDIF error: illegal wrapping at input line '.$this->_input_line, $this->_input_line);
+                                } else {
+                                    $last                = array_pop($this->_lines_next);
+                                    $last                = $last.trim($matches[1]);
+                                    $this->_lines_next[] = $last;
+                                    $datalines_read++;
+                                }
+                            }
+                        } elseif (preg_match('/^#/', $data)) {
+                            // LDIF comments
+                            $commentmode = true;
+                        } elseif (preg_match('/^\s*$/', $data)) {
+                            // empty line but we had no data for this
+                            // entry, so just ignore this line
+                            $commentmode = false;
+                        } else {
+                            $this->dropError('Net_LDAP2_LDIF error: invalid syntax at input line '.$this->_input_line, $this->_input_line);
+                            continue;
+                        }
+
+                    }
+                }
+            }
+        }
+        return $this->_lines_next;
+    }
+
+    /**
+    * Convert an attribute and value to LDIF string representation
+    *
+    * It honors correct encoding of values according to RFC 2849.
+    * Line wrapping will occur at the configured maximum but only if
+    * the value is greater than 40 chars.
+    *
+    * @param string $attr_name  Name of the attribute
+    * @param string $attr_value Value of the attribute
+    *
+    * @access protected
+    * @return string LDIF string for that attribute and value
+    */
+    protected function convertAttribute($attr_name, $attr_value)
+    {
+        // Handle empty attribute or process
+        if (strlen($attr_value) == 0) {
+            $attr_value = " ";
+        } else {
+            $base64 = false;
+            // ASCII-chars that are NOT safe for the
+            // start and for being inside the value.
+            // These are the int values of those chars.
+            $unsafe_init = array(0, 10, 13, 32, 58, 60);
+            $unsafe      = array(0, 10, 13);
+
+            // Test for illegal init char
+            $init_ord = ord(substr($attr_value, 0, 1));
+            if ($init_ord > 127 || in_array($init_ord, $unsafe_init)) {
+                $base64 = true;
+            }
+
+            // Test for illegal content char
+            for ($i = 0; $i < strlen($attr_value); $i++) {
+                $char_ord = ord(substr($attr_value, $i, 1));
+                if ($char_ord > 127 || in_array($char_ord, $unsafe)) {
+                    $base64 = true;
+                }
+            }
+
+            // Test for ending space
+            if (substr($attr_value, -1) == ' ') {
+                $base64 = true;
+            }
+
+            // If converting is needed, do it
+            // Either we have some special chars or a matching "raw" regex
+            if ($base64 || ($this->_options['raw'] && preg_match($this->_options['raw'], $attr_name))) {
+                $attr_name .= ':';
+                $attr_value = base64_encode($attr_value);
+            }
+
+            // Lowercase attr names if requested
+            if ($this->_options['lowercase']) $attr_name = strtolower($attr_name);
+
+            // Handle line wrapping
+            if ($this->_options['wrap'] > 40 && strlen($attr_value) > $this->_options['wrap']) {
+                $attr_value = wordwrap($attr_value, $this->_options['wrap'], PHP_EOL." ", true);
+            }
+        }
+
+        return $attr_name.': '.$attr_value;
+    }
+
+    /**
+    * Convert an entries DN to LDIF string representation
+    *
+    * It honors correct encoding of values according to RFC 2849.
+    *
+    * @param string $dn UTF8-Encoded DN
+    *
+    * @access protected
+    * @return string LDIF string for that DN
+    * @todo I am not sure, if the UTF8 stuff is correctly handled right now
+    */
+    protected function convertDN($dn)
+    {
+        $base64 = false;
+        // ASCII-chars that are NOT safe for the
+        // start and for being inside the dn.
+        // These are the int values of those chars.
+        $unsafe_init = array(0, 10, 13, 32, 58, 60);
+        $unsafe      = array(0, 10, 13);
+
+        // Test for illegal init char
+        $init_ord = ord(substr($dn, 0, 1));
+        if ($init_ord >= 127 || in_array($init_ord, $unsafe_init)) {
+            $base64 = true;
+        }
+
+        // Test for illegal content char
+        for ($i = 0; $i < strlen($dn); $i++) {
+            $char = substr($dn, $i, 1);
+            if (ord($char) >= 127 || in_array($init_ord, $unsafe)) {
+                $base64 = true;
+            }
+        }
+
+        // Test for ending space
+        if (substr($dn, -1) == ' ') {
+            $base64 = true;
+        }
+
+        // if converting is needed, do it
+        return ($base64)? 'dn:: '.base64_encode($dn) : 'dn: '.$dn;
+    }
+
+    /**
+    * Writes an attribute to the filehandle
+    *
+    * @param string       $attr_name   Name of the attribute
+    * @param string|array $attr_values Single attribute value or array with attribute values
+    *
+    * @access protected
+    * @return void
+    */
+    protected function writeAttribute($attr_name, $attr_values)
+    {
+        // write out attribute content
+        if (!is_array($attr_values)) {
+            $attr_values = array($attr_values);
+        }
+        foreach ($attr_values as $attr_val) {
+            $line = $this->convertAttribute($attr_name, $attr_val).PHP_EOL;
+            $this->writeLine($line, 'Net_LDAP2_LDIF error: unable to write attribute '.$attr_name.' of entry '.$this->_entrynum);
+        }
+    }
+
+    /**
+    * Writes a DN to the filehandle
+    *
+    * @param string $dn DN to write
+    *
+    * @access protected
+    * @return void
+    */
+    protected function writeDN($dn)
+    {
+        // prepare DN
+        if ($this->_options['encode'] == 'base64') {
+            $dn = $this->convertDN($dn).PHP_EOL;
+        } elseif ($this->_options['encode'] == 'canonical') {
+            $dn = Net_LDAP2_Util::canonical_dn($dn, array('casefold' => 'none')).PHP_EOL;
+        } else {
+            $dn = $dn.PHP_EOL;
+        }
+        $this->writeLine($dn, 'Net_LDAP2_LDIF error: unable to write DN of entry '.$this->_entrynum);
+    }
+
+    /**
+    * Finishes an LDIF entry
+    *
+    * @access protected
+    * @return void
+    */
+    protected function finishEntry()
+    {
+        $this->writeLine(PHP_EOL, 'Net_LDAP2_LDIF error: unable to close entry '.$this->_entrynum);
+    }
+
+    /**
+    * Just write an arbitary line to the filehandle
+    *
+    * @param string $line  Content to write
+    * @param string $error If error occurs, drop this message
+    *
+    * @access protected
+    * @return true|false
+    */
+    protected function writeLine($line, $error = 'Net_LDAP2_LDIF error: unable to write to filehandle')
+    {
+        if (is_resource($this->handle()) && fwrite($this->handle(), $line, strlen($line)) === false) {
+            $this->dropError($error);
+            return false;
+        } else {
+            return true;
+        }
+    }
+
+    /**
+    * Optionally raises an error and pushes the error on the error cache
+    *
+    * @param string $msg  Errortext
+    * @param int    $line Line in the LDIF that caused the error
+    *
+    * @access protected
+    * @return void
+    */
+    protected function dropError($msg, $line = null)
+    {
+        $this->_error['error'] = new Net_LDAP2_Error($msg);
+        if ($line !== null) $this->_error['line'] = $line;
+
+        if ($this->_options['onerror'] == 'die') {
+            die($msg.PHP_EOL);
+        } elseif ($this->_options['onerror'] == 'warn') {
+            echo $msg.PHP_EOL;
+        }
+    }
+}
+?>