ldap_explode_dn

(PHP 4, PHP 5, PHP 7, PHP 8)

ldap_explode_dnSplits DN into its component parts

Description

ldap_explode_dn(string $dn, int $with_attrib): array|false

Splits the DN returned by ldap_get_dn() and breaks it up into its component parts. Each part is known as Relative Distinguished Name, or RDN.

Parameters

dn

The distinguished name of an LDAP entity.

with_attrib

Used to request if the RDNs are returned with only values or their attributes as well. To get RDNs with the attributes (i.e. in attribute=value format) set with_attrib to 0 and to get only values set it to 1.

Return Values

Returns an array of all DN components, or false on failure. The first element in the array has count key and represents the number of returned values, next elements are numerically indexed DN components.

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User Contributed Notes 6 notes

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5
gabriel at hrz dot uni-marburg dot de
20 years ago
Keep attention on UTF8 encoded DNs. Since openLDAP >=2.1.2
ldap_explode_dn turns unprintable chars (in the ASCII sense, UTF8
encoded) into \<hexcode>.

Example:

$dn="ou=Universität ,c=DE";
var_dump(ldap_explode_dn($dn,0));

//returns

array(3) {
  ["count"]=>
  int(2)
  [0]=>
  string(19) "ou=Universit\C3\A4t"
  [1]=>
  string(4) "c=DE"
}

Unfortunately, PHP don't support the ldap functions ldap_str2dn and
ldap_dn2str, but by means of preg_replace a workaround is possible to
recover the old behaviour of ldap_explode_dn

// workaround
function myldap_explode_dn($dn,$with_attribute){

$result=ldap_explode_dn ($dn, $with_attrib);
//translate hex code into ascii again
    foreach($result as $key=>$value){
          $result[$key]=preg_replace("/\\\([0-9A-Fa-f]{2})/e", "''.chr(hexdec('\\1')).''", $value);
    }
    return($result);

}
//
//then follows for the example

$dn="ou=Universität ,c=DE";
var_dump(myldap_explode_dn($dn,0));

//returns

array(3) {
  ["count"]=>
  int(2)
  [0]=>
  string(15) "ou=Universität"
  [1]=>
  string(4) "c=DE"
}
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2
hello+php at NOSPAM dot renoirboulanger dot com
11 years ago
I came accros this page and enjoyed the comments.

Since a LDAP string can sometimes be lengthy and have many attributes, I needed to be able to sort through all that is in.

In my case, I needed to get the subdomain part and other parameters.

Here is how I built my method.
<?php
   
/**
     * Parse, and format a DN string to Array
     *
     * Read a LDAP DN, and return an array keys
     * listing all similar attributes.
     *
     * Also takes care of the character escape and unescape
     *
     * Example:
     * CN=username,OU=UNITNAME,OU=Region,OU=Country,DC=subdomain,DC=domain,DC=com
     *
     * Would normally return:
     * Array (
     *     [count] => 9
     *     [0] => CN=username
     *     [1] => OU=UNITNAME
     *     [2] => OU=Region
     *     [5] => OU=Country
     *     [6] => DC=subdomain
     *     [7] => DC=domain
     *     [8] => DC=com
     * )
     *
     * Returns instead a manageable array:
     * array (
     *     [CN] => array( username )
     *     [OU] => array( UNITNAME, Region, Country )
     *     [DC] => array ( subdomain, domain, com )
     * )
     *
     *
     * @author gabriel at hrz dot uni-marburg dot de 05-Aug-2003 02:27 (part of the character replacement)
     * @author Renoir Boulanger
     *
     * @param  string $dn          The DN
     * @return array
     */
   
function parseLdapDn($dn)
    {
       
$parsr=ldap_explode_dn($dn, 0);
       
//$parsr[] = 'EE=Sôme Krazï string';
        //$parsr[] = 'AndBogusOne';
       
$out = array();
        foreach(
$parsr as $key=>$value){
            if(
FALSE !== strstr($value, '=')){
                list(
$prefix,$data) = explode("=",$value);
               
$data=preg_replace("/\\\\\\([0-9A-Fa-f]{2})/e", "''.chr(hexdec('\\\\1')).''", $data);
                if(isset(
$current_prefix) && $prefix == $current_prefix){
                   
$out[$prefix][] = $data;
                } else {
                   
$current_prefix = $prefix;
                   
$out[$prefix][] = $data;
                }
            }
        }
        return
$out;
    }
?>
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2
eero at eero dot info
6 years ago
I was converting LDAP related code to PHP7 which doesn't support /e modifier with preg_replace anymore, but instead you should use preg_replace_callback. This might help someone working on the same thing:

<?php

$value
= 'Universität';

# < PHP7 compatible code
echo preg_replace("/\\\([0-9A-Fa-f]{2})/e", "''.chr(hexdec('\\1')).''", $value);

# >= PHP7 compatible code
echo preg_replace_callback('/\\\([0-9A-Fa-f]{2})/', function ($matches) { return chr(hexdec($matches[1])); }, $value);
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0
emepese
6 years ago
Probably not the best way but for those who are looking for a way to get de CN of a DN without the "cn=" part this is a function with a regex pattern:

<?php
   
function getCNofDN($dn) {
       
$return=preg_match('/[^cn=]([^,]*)/i',$dn,$dn);
        return(
$dn[0]);
    }

  echo
getCNofDN("cn=emepese,cn=someLevel,dc=someCompany");

// Will print "emepese"

?>
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0
DavidSmith at byu dot net
20 years ago
[ Editor's Note: The segfault has been fixed and will not occur in PHP 4.3.4 or PHP 5.0.0 when they are released.  However, it is still important to escape special characters as detailed below. ]

If your DN contains < or > characters, you must escape them with a backslash or ldap_explode_dn() will give you a "wrong parameter count" error or even a segmentation fault.

For example, these calls will fail with a "wrong parameter count" or a seg fault:

  ldap_explode_dn( "cn=<bob>,dc=example,dc=com", 0 );
  ldap_explode_dn( 'cn=<bob>,dc=example,dc=com', 0 );

But this will succeed

  ldap_explode_dn( "cn=\<bob\>,dc=example,dc=com", 0 );

Notice also that the < and > are escaped with hex codes as noted above. This function is a nice wrapper that properly formats all DNs and can safely be called with < and > characters, and UTF-8 characters:

function my_explode_dn( $dn, $with_attributes=0 )
{
        $dn = addcslashes( $dn, "<>" );
        $result = ldap_explode_dn( $dn, $with_attributes );
        //translate hex code into ascii again
        foreach( $result as $key => $value )
                $result[$key] = preg_replace("/\\\([0-9A-Fa-f]{2})/e", "''.chr(hexdec('\\1')).''", $value);
        return $result;
}

I am using php 4.3.1. Good luck!
up
0
bs at muekno dot de
22 years ago
Copying is much better than typing!!!!
Just modify the constants.
Best wishes (and thanX 4 this helpfull site),
Bernd Schwaegerl
Mueller-Knoche GmbH, Systemhaus fuer EDV-Loesungen

# Example:

$HOST = "Yourhostname";
$USER_DN = "Yourldapuser_dn";
$PWD = "Ldapuserpassword";
$BASE_DN = "o=Your_organisation";
$SEARCH_OBJECT="sn=YOUR_SEARCH_PERSON_OBJECTS_SN";

$ldap_handle=ldap_connect($HOST);
$bind_result=ldap_bind($ldap_handle,$USER_DN,$PWD);

$search_result=ldap_search($ldap_handle,$BASE_DN,$SEARCH_OBJECT);
$result=ldap_get_entries($ldap_handle,$search_result);
$result_array=ldap_get_entries($ldap_handle,$result);
$whole_dn=$result_array[0]["dn"];

$dn_parts=ldap_explode_dn($whole_dn,0);
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