GNU.WIKI: The GNU/Linux Knowledge Base

  [HOME] [HowTo] [ABS] [MAN1] [MAN2] [MAN3] [MAN4] [MAN5] [MAN6] [MAN7] [MAN8] [MAN9]



Luiz Ernesto Pinheiro Mal�re

<malere _at_>

v1.10, 2007-03-18
Revision History                                                             
Revision 1.10           2007/03/18                                           
Pointer to updated documentation                                             
Revision 1.09           2004/03/05                                           
OpenLDAP 2.2 and general corrections.                                        
Revision 1.08           2003/04/02                                           
SASL with DIGEST-MD5 authentication.                                         
Revision 1.07           2002/09/16                                           
Typo correction.                                                             
Revision 1.06           2002/07/17                                           
Migration to DocBook XML standard, revision of the role document. Introducing
OpenLDAP 2.1.                                                                
Revision 1.05           2001/06/22           Revised by: lepm                
Correction of long lines that were causing inconsistences on the PDF version 
of the document.                                                             
Revision 1.04           2001/02/28           Revised by: lepm                
Correction of more typos and update on the following sections: Roaming       
Access, Authentication using LDAP.                                           
Revision 1.03           2000/09/28           Revised by: lepm                
Presenting OpenLDAP 2.0, which comprises LDAPv3, as defined on [ftp://] RFC2251                                    
Revision 1.02           2000/09/13           Revised by: lepm                
Correction of typos and addition of the section History of Releases.         
Revision 1.01           2000/02/15           Revised by: lepm                
Added the following sections: LDAP Migration Tools, Authentication using     
LDAP, Graphical LDAP tools, RFCs.                                            
Revision 1.00           1999/06/20           Revised by: lepm                
Initial version.                                                             

Information about installing, configuring, running and maintaining a LDAP
(Lightweight Directory Access Protocol) Server on a Linux machine is
presented on this document. The document also presents details about how to
create LDAP databases, how to add, how to update and how to delete
information on the directory. This paper is mostly based on the University of
Michigan LDAP information pages and on the OpenLDAP Administrator's Guide.

Table of Contents
1. Introduction
    1.1. What's LDAP ?
    1.2. How does LDAP work ?
    1.3. LDAP backends, objects and attributes
    1.4. New versions of this document
    1.5. Opinions and Sugestions
    1.6. Acknowledgments
    1.7. Copyright and Disclaimer
2. Installing the LDAP Server
    2.1. Pre-Requirements
    2.2. Downloading the Package
    2.3. Unpacking the Software
    2.4. Configuring the Software
    2.5. Building the Server
3. Configuring the LDAP Server
    3.1. Configuration File Format
    3.2. Global Directives
    3.3. General Backend Directives
    3.4. General Database Directives
    3.5. BDB Database Directives
    3.6. LDBM Database Directives
    3.7. Access Control Examples
    3.8. Configuration File Example
4. Running the LDAP Server
    4.1. Command Line Options
    4.2. Starting the LDAP Server
    4.3. Killing the LDAP Server
5. Database Creation and Maintenance
    5.1. Creating a Database online
    5.2. Creating a Database offline
    5.3. More on the LDIF Format
    5.4. The ldapsearch, ldapdelete and ldapmodify utilities
6. Additional Information and Features
    6.1. LDAP Migration Tools
    6.2. Authentication using LDAP
    6.3. SASL Configuration: Digest-MD5
    6.4. Graphical LDAP tools
    6.5. Logs
7. References
    7.1. URL's
    7.2. Books
    7.3. RFC's

List of Tables
3-1. Debugging Levels
3-2. Database Backends
4-1. Debugging Levels

Chapter 1. Introduction

This document is no longer being updated, for the latest documentation,
please refer to: [] OpenLDAP
Administrator's Guide

The main purpose of this document is to set up and use a LDAP Directory
Server on your Linux machine.You will learn how to install, configure, run
and maintain the LDAP server. After you also learn how you can store,
retrieve and update information on your Directory using the LDAP clients and
utilities. The daemon for the LDAP directory server is called slapd and it
runs on many different UNIX platforms.

There is another daemon that cares for replication between LDAP servers. It's
called slurpd and for the moment you don't need to worry about it. In this
document you will run a slapd which provides directory service for your local
domain only, without replication, so without slurpd. Complete information
about replication is available at: OpenLDAP Administrator's Guide

The local domain setup represents a simple choice for configuring your
server, good for starting and easy to upgrade to another configuration later
if you want. The information presented on this document represents a nice
initialization on using the LDAP server. Possibly after reading this document
you will feel encouraged to expand the capabilities of your server and even
write your own clients, using the already available C, C++ and Java
Development Kits.

1.1. What's LDAP ?

LDAP stands for Lightweight Directory Access Protocol. As the name suggests,
it is a lightweight client-server protocol for accessing directory services,
specifically X.500-based directory services. LDAP runs over TCP/IP or other
connection oriented transfer services. LDAP is defined in [
in-notes/rfc2251.txt] RFC2251 "The Lightweight Directory Access Protocol

A directory is similar to a database, but tends to contain more descriptive,
attribute-based information. The information in a directory is generally read
much more often than it is written. Directories are tuned to give
quick-response to high-volume lookup or search operations. They may have the
ability to replicate information widely in order to increase availability and
reliability, while reducing response time. When directory information is
replicated, temporary inconsistencies between the replicas may be OK, as long
as they get in sync eventually.

There are many different ways to provide a directory service. Different
methods allow different kinds of information to be stored in the directory,
place different requirements on how that information can be referenced,
queried and updated, how it is protected from unauthorized access, etc. Some
directory services are local, providing service to a restricted context
(e.g., the finger service on a single machine). Other services are global,
providing service to a much broader context.

1.2. How does LDAP work ?

LDAP directory service is based on a client-server model. One or more LDAP
servers contain the data making up the LDAP directory tree or LDAP backend
database. An LDAP client connects to an LDAP server and asks it a question.
The server responds with the answer, or with a pointer to where the client
can get more information (typically, another LDAP server). No matter what
LDAP server a client connects to, it sees the same view of the directory; a
name presented to one LDAP server references the same entry it would at
another LDAP server. This is an important feature of a global directory
service, like LDAP.

1.3. LDAP backends, objects and attributes

The LDAP server daemon is called Slapd. Slapd supports a variety of different
database backends which you can use.

They include the primary choice BDB, a high-performance transactional
database backend; LDBM, a lightweight DBM based backend; SHELL, a backend
interface to arbitrary shell scripts and PASSWD, a simple backend interface
to the passwd(5) file.

BDB utilizes [] Sleepycat Berkeley DB 4. LDBM
utilizes either [] Berkeley DB or [http://] GDBM.

BDB transactional backend is suited for multi-user read/write database
access, with any mix of read and write operations. BDB is used in
applications that require:

��*�Transactions, including making multiple changes to the database
    atomically and rolling back uncommitted changes when necessary.
��*�Ability to recover from systems crashes and hardware failures without
    losing any committed transactions.

In this document I assume that you choose the BDB database.

To import and export directory information between LDAP-based directory
servers, or to describe a set of changes which are to be applied to a
directory, the file format known as LDIF, for LDAP Data Interchange Format,
is typically used. A LDIF file stores information in object-oriented
hierarchies of entries. The LDAP software package you're going to get comes
with an utility to convert LDIF files to the BDB format

A common LDIF file looks like this:
dn: o=TUDelft, c=NL                                                          
o: TUDelft                                                                   
objectclass: organization                                                    
dn: cn=Luiz Malere, o=TUDelft, c=NL                                          
cn: Luiz Malere                                                              
sn: Malere                                                                   
objectclass: person                                                          

As you can see each entry is uniquely identified by a distinguished name, or
DN. The DN consists of the name of the entry plus a path of names tracing the
entry back to the top of the directory hierarchy (just like a tree).

In LDAP, an object class defines the collection of attributes that can be
used to define an entry. The LDAP standard provides these basic types of
object classes:

��*�Groups in the directory, including unordered lists of individual objects
    or groups of objects.
��*�Locations, such as the country name and description.
��*�Organizations in the directory.
��*�People in the directory.

An entry can belong to more than one object class. For example, the entry for
a person is defined by the person object class, but may also be defined by
attributes in the inetOrgPerson, groupOfNames, and organization
objectclasses. The server's object class structure (it's schema) determines
the total list of required and allowed attributes for a particular entry.

Directory data is represented as attribute-value pairs. Any specific piece of
information is associated with a descriptive attribute.

For instance, the commonName, or cn, attribute is used to store a person's
name . A person named Jonas Salk can be represented in the directory as
cn: Jonas Salk                                                               

Each person entered in the directory is defined by the collection of
attributes in the person object class. Other attributes used to define this
entry could include:
givenname: Jonas                                                             
surname: Salk                                                                

Required attributes include the attributes that must be present in entries
using the object class. All entries require the objectClass attribute, which
lists the object classes to which an entry belongs.

Allowed attributes include the attributes that may be present in entries
using the object class. For example, in the person object class, the cn and
sn attributes are required. The description, telephoneNumber, seeAlso, and
userpassword attributes are allowed but are not required.

Each attribute has a corresponding syntax definition. The syntax definition
describes the type of information provided by the attribute, for instance:

��*�bin binary.
��*�ces case exact string (case must match during comparisons).
��*�cis case ignore string (case is ignored during comparisons).
��*�tel telephone number string (like cis but blanks and dashes `- ' are
    ignored during comparisons).
��*�dn distinguished name.

Note: Usually objectclass and attribute definitions reside on schema files,
on the subdirectory schema under the OpenLDAP installation home.

1.4. New versions of this document

This document may receive corrections and updates based on the feedback
received by the readers. You should look at:


for new versions of this HOWTO.

1.5. Opinions and Sugestions

If you have any kind of doubt about some information avaiable on this
document, please contact me on the following email address:

If you have commentaries and/or sugestions, please let me know too!

1.6. Acknowledgments

This Howto was result of an internship made by me on the TUDelft University -
Netherlands. I would like to thank the persons that encouraged me to write
this document: Rene van Leuken and Wim Tiwon. Thank you very much. They are
also Linux fans, just like me.

I would like to thank also Thomas Bendler, author of the German Ldap-Howto,
for his contributions to my document and Joshua Go, great volunteer on the
LDP project.

Karl Lattimer deserves a prize, for his great contribution on SASL related

And thanks my Lord!

1.7. Copyright and Disclaimer

Copyright (c) 1999 Luiz Ernesto Pinheiro Mal�re. Permission is granted to
copy, distribute and/or modify this document under the terms of the GNU Free
Documentation License, Version 1.1 or any later version published by the Free
Software Foundation; with no Invariant Sections, with no Front-Cover Texts
and with no Back-Cover Texts. A copy of the license is included in the
section entitled "GNU Free Documentation License".

If you have questions, please visit the following url: [
licenses/fdl.txt] and contact the Linux
HOWTO coordinator, at: []

Chapter 2. Installing the LDAP Server

Five steps are necessary to install the server:

��*�Install the pre-required packages (if not already installed).
��*�Download the server.
��*�Unpack the software.
��*�Configure the Makefiles.
��*�Build the server.

2.1. Pre-Requirements

To be fully LDAPv3 compliant, OpenLDAP clients and servers require
installation of some additional packages. For writing this document, I've
used a Mandrake 9.0 box with a 2.4.20 Kernel, manually installing the
Berkeley BDB package and SASL libraries.

OpenSSL TLS Libraries

The OpenSSL TLS libraries are normally part of the base system or compose an
optional software component. The official OpenSSL url is: [http://]

Kerberos Authentication Services

OpenLDAP clients and servers support Kerberos-based authentication services.
In particular, OpenLDAP supports SASL/GSSAPI authentication mechanism using
either Heimdal or MIT Kerberos V packages. If you desire to use
Kerberos-based SASL/GSSAPI authentication, you should install either Heimdal
or MIT Kerberos V. Heimdal Kerberos is available from [
heimdal] MIT Kerberos is available from [http:/

The use of strong authentication services, such as those provided by
Kerberos, is highly recommended.

Cyrus's Simple Authentication and Security Layer Libraries

Cyrus's SASL libraries are normally part of the base system or compose an
optional software component. Cyrus SASL is available from [http://]
sasl-library.html. Cyrus SASL will make use of OpenSSL and Kerberos/GSSAPI
libraries if preinstalled. By the time of this writing, I've used Cyrus SASL

Database Software

Slapd's primary database backend, BDB, requires []
Sleepycat Software Berkeley DB, version 4. If not available at configure
time, you will not be able to build slapd with primary database backend.

Your operating system may provide Berkeley DB, version 4, in the base system
or as an optional software component. If not, there are several versions
available at [] Sleepycat. At the time
of this writing, the latest release, version 4.2.52, is recommended.
OpenLDAP's slapd LDBM backend supports a variety of database managers, like
Berkeley DB (version 3) and GDBM. GDBM is available from [
/] FSF's download site []


Threads support are almost guaranteed to be part of your base Linux system.
OpenLDAP is designed to take advantage of threads. OpenLDAP supports POSIX
pthreads, Mach CThreads, and a number of other varieties. The configure
script will complain if it cannot find a suitable thread subsystem. If this
occurs, please consult the Software - Installation - Platform Hints section
of the OpenLDAP FAQ: []

TCP Wrappers

Slapd supports TCP wrappers (IP level access control filters) if
preinstalled. Use of TCP wrappers or other IP-level access filters (such as
those provided by an IP-level firewall) is recommended for servers containing
non-public information.

2.2. Downloading the Package

There are two free distributed LDAP servers: University of Michigan LDAP
server and OpenLDAP server. There's also the Netscape Directory Server, which
is free only under some conditions (educational institutions get it free, for
example). The OpenLDAP server is based on the latest version of the
University of Michigan Server and there are mailing lists and additional
documentation available for it. This document assumes that you are using the
OpenLDAP server.

It's latest tar gzipped version is avaiable on the following address:


If you want to get the latest version of University of Michigan Server, go to
this address:


To write this document, I used the 2.2.5 version of the OpenLDAP package. My
operating system is a Mandrake Linux 9.0 with kernel 2.4.20.

On the OpenLDAP site you can always find the latest development and stable
versions of the OpenLDAP server. By the time this document was updated, the
latest stable version was openldap-stable-20031217.tgz (version 2.1.25). The
latest development version was also openldap-2.2.5.tgz.

2.3. Unpacking the Software

Now that you have the tar gzipped package on your local machine, you can
unpack it.

First copy the package to a desirable directory, for example /usr/local. Next
use the following command:
tar xvzf openldap-2.2.5.tgz                                                  

You can use this command too, as well:
gunzip openldap-2.2.5.tgz | tar xvf -                                        

2.4. Configuring the Software

The OpenLDAP server sources are distributed with a configuration script for
setting options like installation directories, compiler and linker flags.
Type the following command on the directory where you unpacked the software:
./configure --help                                                           

This will print all options that you can customize with the configure script
before you build the software. Some usefull options are --prefix=pref ,
--exec-prefix=eprefix and --bindir=dir, for setting instalation directories.
Normally if you run configure without options, it will auto-detect the
appropriate settings and prepare to build things on the default common
location. So just type:

And watch the output to see if all went well

Tip: Sometimes you need to pass specific options to your configure script,
like for example --with-tls (for enabling slapd to use a secure channel:
LDAPS://). In this case, you might have your SSL/TLS libraries residing on a
non-standard directory of your system. You can make the configure script
aware of the libraries location changing you environment with the env
command. Example: suppose you've installed the openssl package under /usr/
local/openssl. The following command will build slapd with SSL/TLS support:
env CPPFLAGS=-I/usr/local/openssl/include \                                  
      LDFLAGS=-L/usr/local/openssl/lib \                                     
      configure --with-tls ...                                               

You can specify the following environment variables with the env command
before the configure script:

��*�CC: Specify alternative C Compiler.
��*�CFLAGS: Specify additional compiler flags.
��*�CPPFLAGS: Specify C Preprocessor flags.
��*�LDFLAGS: Specify linker flags.
��*�LIBS: Specify additional libraries.

2.5. Building the Server

After configuring the software you can start building it. First build the
dependencies, using the command:
make depend                                                                  

Build the server after that, using the command:

If all goes well, the server will build as configured. If not, return to the
previous step to review the configuration settings. You should read the
INSTALL and README files located in the directory where you unpacked the
software. Also, check the configure script specific hints, they are located
in the path doc/install/configure under the directory you unpacked the

To ensure a correct build, you should run the test suite (it only takes a few
make test                                                                    

Tests which apply to your configuration will run and they should pass. Some
tests, such as the replication test, may be skipped.

Now install the binaries and man pages. You may need to be superuser to do
this (depending on where you are installing things):
su root -c 'make install'                                                    

That's all, now you have the binary of the server and the binaries of several
other utilities. Go to the Chapter 3 section to see how to configure the
operation of your LDAP server.

Chapter 3. Configuring the LDAP Server

Once the software has been installed and built, you are ready to configure it
for use at your site. All slapd runtime configuration is accomplished through
the slapd.conf file, installed in the prefix directory you specified in the
configuration script or by default in /usr/local/etc/openldap.

This section details the commonly used configuration directives in 
slapd.conf. For a complete list, see the slapd.conf(5) manual page. The
configuration file directives are separated into global, backend specific and
database specific. Here you will find descriptions of directives, together
with their default values (if any) and examples of use.

3.1. Configuration File Format

The slapd.conf file consists of three types of configuration information:
global, backend specific, and database specific. Global information is
specified first, followed by information associated with a particular backend
type, which is then followed by information associated with a particular
database instance.

Global directives can be overridden in a backend and/or database directives,
backend directives can be overridden by database directives.

Blank lines and comment lines beginning with a '#' character are ignored. If
a line begins with white space, it is considered a continuation of the
previous line (even if the previous line is a comment). The general format of
slapd.conf is as follows:
# global configuration directives                                            
<global config directives>                                                   
# backend definition                                                         
backend <typeA>                                                              
<backend-specific directives>                                                
# first database definition & config directives                              
database <typeA>                                                             
<database-specific directives>                                               
# second database definition & config directives                             
database <typeB>                                                             
<database-specific directives>                                               
# second "typeA" database definition & config directives                     
database <typeA>                                                             
<database-specific directives>                                               
# subsequent backend & database definitions & config directives              

A configuration directive may take arguments. If so, they are separated by
white space. If an argument contains white space, the argument should be
enclosed in double quotes "like this". If an argument contains a double quote
or a backslash character `\', the character should be preceded by a backslash
character `\'.

The distribution contains an example configuration file that will be
installed in the /usr/local/etc/openldap directory. A number of files
containing schema definitions (attribute types and object classes) are also
provided in the /usr/local/etc/openldap/schema directory.

3.2. Global Directives

Directives described in this section apply to all backends and databases
unless specifically overridden in a backend or database definition. Arguments
that should be replaced by actual text are shown in brackets <>.
access to <what> [ by <who> <accesslevel> <control> ]+                       

This directive grants access (specified by <accesslevel>) to a set of entries
and/or attributes (specified by <what>) by one or more requesters (specified
by <who>). See the Section 3.7 examples for more details.

Important: If no access directives are specified, the default access control
policy, access to * by * read, allows all both authenticated and anonymous
users read access.
attributetype <RFC2252 Attribute Type Description>                           

This directive defines an attribute type. Check the following URL for more
details: [] Schema
idletimeout <integer>                                                        

Specify the number of seconds to wait before forcibly closing an idle client
connection. An idletimeout of 0, the default, disables this feature.
include <filename>                                                           

This directive specifies that slapd should read additional configuration
information from the given file before continuing with the next line of the
current file. The included file should follow the normal slapd config file
format. The file is commonly used to include files containing schema

Note:You should be careful when using this directive - there is no small
limit on the number of nested include directives, and no loop detection is
loglevel <integer>                                                           

This directive specifies the level at which debugging statements and
operation statistics should be syslogged (currently logged to the syslogd(8)
LOCAL4 facility). You must have configured OpenLDAP --enable-debug (the
default) for this to work (except for the two statistics levels, which are
always enabled). Log levels are additive. To display what numbers correspond
to what kind of debugging, invoke slapd with -? or consult the table below.
The possible values for <integer> are:

Table 3-1. Debugging Levels
|Level|Description                              |
|-1   |enable all debugging                     |
|0    |no debugging                             |
|1    |trace function calls                     |
|2    |debug packet handling                    |
|4    |heavy trace debugging                    |
|8    |connection management                    |
|16   |print out packets sent and received      |
|32   |search filter processing                 |
|64   |configuration file processing            |
|128  |access control list processing           |
|256  |stats log connections/operations/results |
|512  |stats log entries sent                   |
|1024 |print communication with shell backends  |
|2048 |print entry parsing debugging            |


loglevel 255 or loglevel -1

This will cause lots and lots of debugging information to be syslogged.


loglevel 256
objectclass <RFC2252 Object Class Description>                               

This directive defines an object class. Check the following URL for more
details: [] Schema
referral <URI>                                                               

This directive specifies the referral to pass back when slapd cannot find a
local database to handle a request.


referral ldap://

This will refer non-local queries to the global root LDAP server at the
OpenLDAP Project. Smart LDAP clients can re-ask their query at that server,
but note that most of these clients are only going to know how to handle
simple LDAP URLs that contain a host part and optionally a distinguished name
sizelimit <integer>                                                          

This directive specifies the maximum number of entries to return from a
search operation.


sizelimit 500
timelimit <integer>                                                          

This directive specifies the maximum number of seconds (in real time) slapd
will spend answering a search request. If a request is not finished in this
time, a result indicating an exceeded timelimit will be returned.


timelimit 3600

3.3. General Backend Directives

Directives in this section apply only to the backend in which they are
defined. They are supported by every type of backend. Backend directives
apply to all databases instances of the same type and, depending on the
directive, may be overridden by database directives.
backend <type>                                                               

This directive marks the beginning of a backend definition. <type> should be
one of bdb or one of other supported backend types listed below:

Table 3-2. Database Backends
|Type   |Description                                           |
|bdb    |Berkeley DB transactional backend                     |
|dnssrv |DNS SRV backend                                       |
|ldbm   |Lightweight DBM backend                               |
|ldap   |Lightweight Directory Access Protocol (Proxy) backend |
|meta   |Meta Directory backend                                |
|monitor|Monitor backend                                       |
|passwd |Provides read-only access to passwd(5)                |
|perl   |Perl programmable backend                             |
|shell  |Shell (external program) backend                      |
|sql    |SQL programmable backend                              |


backend bdb

This marks the beginning of a new BDB backend definition

3.4. General Database Directives

Directives in this section apply only to the database in which they are
defined. They are supported by every type of database.
database <type>                                                              

This directive marks the beginning of a new database instance definition. <
type> should be one of the backend types listed on the previous item.


database bdb

This marks the beginning of a new BDB backend database instance definition.
readonly { on | off }                                                        

This directive puts the database into "read-only" mode. Any attempts to
modify the database will return an "unwilling to perform" error.


readonly off
replica uri=ldap[s]://<hostname>[:<port>] | host=<hostname>[:<port>]         

This directive specifies a replication site for this database. The uri=
parameter specifies a scheme, a host and optionally a port where the slave
slapd instance can be found. Either a domain name or IP address may be used
for <hostname>. If <port> is not given, the standard LDAP port number (389 or
636) is used.

Note: host is deprecated in favor of the uri parameter.

uri allows the replica LDAP server to be specified as an LDAP URI such as
ldap:// or ldaps://

The binddn= parameter gives the DN to bind as for updates to the slave slapd.
It should be a DN which has read/write access to the slave slapd's database.
It must also match the updatedn directive in the slave slapd's config file.
Generally, this DN should not be the same as the rootdn of the master
database. Since DNs are likely to contain embedded spaces, the entire "binddn
=<DN>" string should be enclosed in double quotes.

The bindmethod is simple or kerberos or sasl, depending on whether simple
password-based authentication or Kerberos authentication or SASL
authentication is to be used when connecting to the slave slapd.

Simple authentication should not be used unless adequate integrity and
privacy protections are in place (e.g. TLS or IPSEC). Simple authentication
requires specification of binddn and credentials parameters.

Kerberos authentication is deprecated in favor of SASL authentication
mechanisms, in particular the KERBEROS_V4 and GSSAPI mechanisms. Kerberos
authentication requires binddn and srvtab parameters.

SASL authentication is generally recommended. SASL authentication requires
specification of a mechanism using the saslmech parameter. Depending on the
mechanism, an authentication identity and/or credentials can be specified
using authcid and credentials respectively. The authzid parameter may be used
to specify an authorization identity.

Check this URL for additional details: [
replication.html] Replication with Slurpd.
replogfile <filename>                                                        

This directive specifies the name of the replication log file to which slapd
will log changes. The replication log is typically written by slapd and read
by slurpd. Normally, this directive is only used if slurpd is being used to
replicate the database. However, you can also use it to generate a
transaction log, if slurpd is not running. In this case, you will need to
periodically truncate the file, since it will grow indefinitely otherwise.

Check this URL for additional details: [
replication.html] Replication with Slurpd.
rootdn <dn>                                                                  

This directive specifies the DN that is not subject to access control or
administrative limit restrictions for operations on this database. The DN
need not refer to an entry in the directory. The DN may refer to a SASL

Entry-based Example:

rootdn "cn=Manager, dc=example, dc=com"

SASL-based Example:

rootdn "uid=root,,cn=digest-md5,cn=auth"
rootpw <password>                                                            

This directive can be used to specify a password for the rootdn (when the
rootdn is set to a DN within the database).


rootpw secret

It is also permissible to provide hash of the password in RFC 2307 form.
slappasswd may be used to generate the password hash.


rootpw {SSHA}ZKKuqbEKJfKSXhUbHG3fG8MDn9j1v4QN

The hash was generated using the command slappasswd -s secret.
suffix <dn suffix>                                                           

This directive specifies the DN suffix of queries that will be passed to this
backend database. Multiple suffix lines can be given, and at least one is
required for each database definition.


suffix "dc=example, dc=com"

Queries with a DN ending in "dc=example, dc=com" will be passed to this

Note: When the backend to pass a query to is selected, slapd looks at the
suffix line(s) in each database definition in the order they appear in the
file. Thus, if one database suffix is a prefix of another, it must appear
after it in the config file.

This directive is used to keep a replicated database synchronized with the
master database, so that the replicated database content will be kept up to
date with the master content.

This document doesn't cover in details this directive, because we're
configuring a single LDAP Server. For more informations about this directive,
please visit : [] LDAP Sync
updatedn <dn>                                                                

This directive is only applicable in a slave slapd. It specifies the DN
allowed to make changes to the replica. This may be the DN slurpd binds as
when making changes to the replica or the DN associated with a SASL identity.

Entry-based Example:

updatedn "cn=Update Daemon, dc=example, dc=com"

SASL-based Example:

updatedn "uid=slurpd,,cn=digest-md5,cn=auth"

Check this URL for additional details: [
replication.html] Replication with Slurpd.
updateref <URL>                                                              

This directive is only applicable in a slave slapd. It specifies the URL to
return to clients which submit update requests upon the replica. If specified
multiple times, each URL is provided.


updateref ldap://

3.5. BDB Database Directives

Directives in this category only apply a BDB database. That is, they must
follow a "database bdb" line and come before any subsequent "backend" or
"database" line. For a complete reference of BDB configuration directives,
see the slapd-bdb manpages (man slapd-bdb).
directory <directory>                                                        

This directive specifies the directory where the BDB files containing the
database and associated indexes reside.


directory /usr/local/var/openldap-data
sessionlog <sid> <limit>                                                     

This directive specifies a session log store in the syncrepl replication
provider server which contains information on the entries that have been
scoped out of the replication content identified by <sid>. The first syncrepl
search request having the same <sid> value in the cookie establishes the
session log store in the provider server. The number of the entries in the
session log store is limited by <limit>. Excessive entries are removed from
the store in the FIFO order. Both <sid> and <limit> are non-negative
integers. <sid> has no more than three decimal digits.

The LDAP Content Synchronization operation that falls into a pre-existing
session can use the session log store in order to reduce the amount of
synchronization traffic. If the replica is not so outdated that it can be
made up-to-date by the information in the session store, the provider slapd
will send the consumer slapd the identities of the scoped-out entries
together with the in-scope entries added to or modified within the
replication content. If the replica status is outdated too much and beyond
the coverage of the history store, then the provider slapd will send the
identities of the unchanged in-scope entries along with the changed in-scope
entries. The consumer slapd will then remove those entries in the replica
which are not identified as present in the provider content.

For more informations about syncrepl, please visit : [
/doc/admin22/syncrepl.html] LDAP Sync Replication.

3.6. LDBM Database Directives

Directives in this category only apply to the LDBM backend database. That is,
they must follow a "database ldbm" line and come before any other "database"
or "backend" line. For a complete reference of LDBM configuration directives,
see the slapd-ldbm manpages (man slapd-ldbm).
cachesize <integer>                                                          

This directive specifies the size in entries of the in-memory cache
maintained by the LDBM backend database instance.


cachesize 1000
dbcachesize <integer>                                                        

This directive specifies the size in bytes of the in-memory cache associated
with each open index file. If not supported by the underlying database
method, this directive is ignored without comment. Increasing this number
uses more memory but can cause a dramatic performance increase, especially
during modifies or when building indexes.


dbcachesize 100000

This option, if present, disables database locking. Enabling this option may
improve performance at the expense of data security.

This option causes on-disk database contents not to be immediately
synchronized with in memory changes upon change. Enabling this option may
improve performance at the expense of data security.
directory <directory>                                                        

This directive specifies the directory where the LDBM files containing the
database and associated indexes live.


directory /usr/local/var/openldap-data
index {<attrlist> | default} [pres,eq,approx,sub,none]                       

This directive specifies the indexes to maintain for the given attribute. If
only an <attrlist> is given, the default indexes are maintained.

index default pres,eq                                                        
index uid                                                                    
index cn,sn pres,eq,sub                                                      
index objectClass eq                                                         

The first line sets the default set of indexes to maintain to present and
equality. The second line causes the default (pres,eq) set of indices to be
maintained for the uid attribute type. The third line causes present,
equality and substring indices to be maintained for cn and sn attribute
types. The fourth line causes an equality index for the objectClass attribute

By default, no indices are maintained. It is generally advised that minimally
an equality index upon objectClass be maintained.

index objectClass eq
mode <integer>                                                               

This directive specifies the file protection mode that newly created database
index files should have.


mode 0600

3.7. Access Control Examples

The access control facility provided by the access directive is quite
powerful. This section shows some examples of it's use. First, some simple
access to * by * read                                                        

This access directive grants read access to everyone.

The following example shows the use of a regular expression to select the
entries by DN in two access directives where ordering is significant.
access to dn=".*, o=U of M, c=US"                                            
by * search                                                                  
access to dn=".*, c=US"                                                      
by * read                                                                    

Read access is granted to entries under the c=US subtree, except for those
entries under the "o=U of M, c=US" subtree, to which search access is
granted. No access is granted to c=US as neither access directive matches
this DN.If the order of these access directives was reversed, the
U-M-specific directive would never be matched, since all U-M entries are also
c=US entries.

Another way to implement the same access controls is:
access to dn.children="dc=example,dc=com"                                    
        by * search                                                          
        access to dn.children="dc=com"                                       
        by * read                                                            

Read access is granted to entries under the dc=com subtree, except for those
entries under the dc=example,dc=com subtree, to which search access is
granted. No access is granted to dc=com as neither access directive matches
this DN. If the order of these access directives was reversed, the trailing
directive would never be reached, since all entries under dc=example,dc=com
are also under dc=com entries.

Note: Also note that if no access to directive or no "by <who>" clause
matches, access is denied. That is, every access to directive ends with an
implicit by * none clause and every access list ends with an implicit access
to * by * none directive.

The next example again shows the importance of ordering, both of the access
directives and the "by <who>" clauses. It also shows the use of an attribute
selector to grant access to a specific attribute and various <who> selectors.
access to dn.subtree="dc=example,dc=com" attr=homePhone                      
        by self write                                                        
        by dn.children=dc=example,dc=com" search                             
        by peername=IP:10\..+ read                                           
access to dn.subtree="dc=example,dc=com"                                     
        by self write                                                        
        by dn.children="dc=example,dc=com" search                            
        by anonymous auth                                                    

This example applies to entries in the "dc=example,dc=com" subtree. To all
attributes except homePhone, an entry can write to itself, entries under entries can search by them, anybody else has no access (implicit
by * none) excepting for authentication/authorization (which is always done
anonymously). The homePhone attribute is writable by the entry, searchable by
entries under, readable by clients connecting from network 10,
and otherwise not readable (implicit by * none). All other access is denied
by the implicit access to * by * none.

Sometimes it is useful to permit a particular DN to add or remove itself from
an attribute. For example, if you would like to create a group and allow
people to add and remove only their own DN from the member attribute, you
could accomplish it with an access directive like this:
access to attr=member,entry                                                  
        by dnattr=member selfwrite                                           

The dnattr <who> selector says that the access applies to entries listed in
the member attribute. The selfwrite access selector says that such members
can only add or delete their own DN from the attribute, not other values. The
addition of the entry attribute is required because access to the entry is
required to access any of the entry's attributes.

There's plenty of information about Access Control on the OpenLDAP
Administrator's Guide. Take a look at: [
slapdconfig.html#Access Control] Access Control for more information about
this subject.

3.8. Configuration File Example

The following is an example configuration file, interspersed with explanatory
text. It defines two databases to handle different parts of the X.500 tree;
both are BDB database instances. The line numbers shown are provided for
reference only and are not included in the actual file. First, the global
configuration section:
1.    # example config file - global configuration section                   
2.    include /usr/local/etc/schema/core.schema                              
3.    referral ldap://                                      
4.    access to * by * read                                                  

Line 1 is a comment. Line 2 includes another config file which contains core
schema definitions. The referral directive on line 3 means that queries not
local to one of the databases defined below will be referred to the LDAP
server running on the standard port (389) at the host

Line 4 is a global access control. It applies to all entries (after any
applicable database-specific access controls).

The next section of the configuration file defines a BDB backend that will
handle queries for things in the "dc=example,dc=com" portion of the tree. The
database is to be replicated to two slave slapds, one on truelies, the other
on judgmentday. Indexes are to be maintained for several attributes, and the
userPassword attribute is to be protected from unauthorized access.
5.     # BDB definition for the                                  
6.     database bdb                                                          
7.     suffix "dc=example,dc=com"                                            
8.     directory /usr/local/var/openldap-data                                
9.     rootdn "cn=Manager,dc=example,dc=com"                                 
10.    rootpw secret                                                         
11.    # replication directives                                              
12.    replogfile /usr/local/var/openldap/slapd.replog                       
13.        replica uri=ldap://                         
14.            binddn="cn=Replicator,dc=example,dc=com"                      
15.            bindmethod=simple credentials=secret                          
16.    replica uri=ldaps://                            
17.            binddn="cn=Replicator,dc=example,dc=com"                      
18.            bindmethod=simple credentials=secret                          
19.    # indexed attribute definitions                                       
20.    index uid pres,eq                                                     
21.    index cn,sn,uid pres,eq,sub                                           
22.    index objectClass eq                                                  
23.    # database access control definitions                                 
24.    access to attr=userPassword                                           
25.            by self write                                                 
26.            by anonymous auth                                             
27.            by dn.base="cn=Admin,dc=example,dc=com" write                 
28.            by * none                                                     
29.    access to *                                                           
30.            by self write                                                 
31.            by dn.base="cn=Admin,dc=example,dc=com" write                 
32.            by * read                                                     

Line 5 is a comment. The start of the database definition is marked by the
database keyword on line 6. Line 7 specifies the DN suffix for queries to
pass to this database. Line 8 specifies the directory in which the database
files will live.

Lines 9 and 10 identify the database "super user" entry and associated
password. This entry is not subject to access control or size or time limit
restrictions. Please remeber to encrypt the rootpw using slappasswd.

Example: rootpw {SSHA}Jq4xhhkGa7weT/0xKmaecT4HEXsdqiYA

Lines 11 through 18 are for replication. See the [
/admin22/replication.html] Replication link for more information on these

Lines 20 through 22 indicate the indexes to maintain for various attributes.

Lines 24 through 32 specify access control for entries in the this database.
As this is the first database, the controls also apply to entries not held in
any database (such as the Root DSE). For all applicable entries, the
userPassword attribute is writable by the entry itself and by the "admin"
entry. It may be used for authentication/authorization purposes, but is
otherwise not readable. All other attributes are writable by the entry and
the "admin" entry, but may be read by all users (authenticated or not).

The next section of the example configuration file defines another BDB
database. This one handles queries involving the dc=example,dc=net subtree
but is managed by the same entity as the first database. Note that without
line 39, the read access would be allowed due to the global access rule at
line 4.
33.    # BDB definition for                                      
34.    database bdb                                                          
35.    suffix "dc=example,dc=net"                                            
36.    directory /usr/local/var/openldap-data-net                            
37.    rootdn "cn=Manager,dc=example,dc=com"                                 
38.    index objectClass eq                                                  
39.    access to * by users read                                             

Chapter 4. Running the LDAP Server

The LDAP daemon slapd is designed to be run as a stand-alone server. This
allows the server to take advantage of caching, manage concurrency issues
with underlying databases, and conserve system resources. Running from inetd
(8) is not an option.

4.1. Command Line Options

Slapd supports a number of command-line options as detailed in the manual
page. This section details a few commonly used options:
-f <filename>                                                                

This option specifies an alternate configuration file for slapd. The default
is normally /usr/local/etc/openldap/slapd.conf.
-h <URLs>                                                                    

This option specifies alternative listener configurations. The default is
ldap:/// which implies LDAP over TCP on all interfaces on the default LDAP
port 389. You can specify specific host-port pairs or other protocol schemes
(such as ldaps:// or ldapi://). For example, -h "ldaps:// ldap://
667" will create two listeners: one for LDAP over SSL on all interfaces on
the default LDAP/SSL port 636, and one for LDAP over TCP on the localhost
(loopback) interface on port 667. Hosts may be specified using IPv4
dotted-decimal form or using host names. Port values must be numeric.
-n <service-name>                                                            

This option specifies the service name used for logging and other purposes.
The default service name is slapd.
-l <syslog-local-user>                                                       

This option specifies the local user for the syslog(8) facility. Values can
be LOCAL0, LOCAL1, LOCAL2, ..., and LOCAL7. The default is LOCAL4. This
option may not be supported on all systems. See the Section 6.5 for more
-u user -g group                                                             

These options specify the user and group, respectively, to run slapd as. user
can be either a user name or uid. group can be either a group name or gid.
-r directory                                                                 

This option specifies a run-time directory. slapd will chroot(2) to this
directory after opening listeners but before reading any configuration files
or initializing any backends.
-d <level> | ?                                                               

This option sets the slapd debug level to <level>. When level is a `?'
character, the various debugging levels are printed and slapd exits,
regardless of any other options you give it. Current debugging levels are:

Table 4-1. Debugging Levels
|Level|Description                              |
|-1   |enable all debugging                     |
|0    |no debugging                             |
|1    |trace function calls                     |
|2    |debug packet handling                    |
|4    |heavy trace debugging                    |
|8    |connection management                    |
|16   |print out packets sent and received      |
|32   |search filter processing                 |
|64   |configuration file processing            |
|128  |access control list processing           |
|256  |stats log connections/operations/results |
|512  |stats log entries sent                   |
|1024 |print communication with shell backends  |
|2048 |print entry parsing debugging            |

You may enable multiple levels by specifying the debug option once for each
desired level. Or, since debugging levels are additive, you can do the math
yourself. That is, if you want to trace function calls and watch the config
file being processed, you could set level to the sum of those two levels (in
this case, -d 65). Or, you can let slapd do the math, (e.g. -d 1 -d 64).
Consult <ldap.h> for more details.

Note: slapd must have been compiled with -DLDAP_DEBUG defined for any
debugging information beyond the two stats levels to be available.

4.2. Starting the LDAP Server

In general, slapd is run like this:
/usr/local/etc/libexec/slapd [<option>]*                                     

Where /usr/local/etc/libexec is determined by configure and <option> is one
of the options described above (or in slapd(8)). Unless you have specified a
debugging level (including level 0), slapd will automatically fork and detach
itself from its controlling terminal and run in the background.

4.3. Killing the LDAP Server

To kill off slapd safely, you should give a command like this:
kill -INT `cat $(ETCDIR)/`                                          

Killing slapd by a more drastic method may cause it's databases to be
corrupted, as it may need to flush various buffers before it exits. Note that
slapd writes its pid to a file called in the directory you
configured in slapd.conf file, for example: /usr/local/var/

Slapd will also write its arguments to a file called slapd.args in the
directory you configured in slapd.conf file, for example /usr/local/var/

Chapter 5. Database Creation and Maintenance

This section tells you how to create a slapd database from scratch. There are
two ways to create a database. First, you can create the database on-line
using LDAP. With this method, you simply start up slapd and add entries using
the LDAP client of your choice. This method is fine for relatively small
databases (a few hundred or thousand entries, depending on your
requirements). This method works for database types which support updates.

The second method of database creation is to do it off-line using special
utilities provided with slapd. This method is best if you have many thousands
of entries to create, which would take an unacceptably long time using the
LDAP method, or if you want to ensure the database is not accessed while it
is being created. Note that not all database types support these utilitites.

5.1. Creating a Database online

The OpenLDAP software package comes with an utility called ldapadd, used to
add entries while the LDAP server is running. If you choose to create the
Database online, you can use the ldapadd tool to add entries (you can also
use other clients provided outside the OpenLDAP package to add entries, like
the [] Ldap Browser). After adding the first
entries, you can still use ldapadd to add more entries. You should be sure to
set the following configuration options on your sladp.conf file before
starting slapd:
suffix <dn>                                                                  

As described in the Section 3.4, this option says what entries are to be held
by this database. You should set this to the DN of the root of the subtree
you are trying to create. For example:
suffix "o=TUDelft, c=NL"                                                     

You should be sure to specify a directory where the index files should be
directory /usr/local/tudelft                                                 

You need to create this directory with appropriate permissions so that slapd
can write to it.

You need to configure slapd so that you can connect to it as a directory user
with permission to add entries. You can configure the directory to support a
special super-user or root user just for this purpose. This is done through
the following two options in the database definition:
rootdn <dn>                                                                  
rootpw <passwd>   /* Remember to use a SHA password here !!! */              

These options specify a DN and password that can be used to authenticate as
the "superuser" entry of the database (i.e., the entry allowed to do
anything). The DN and password specified here will always work, regardless of
whether the entry named actually exists or has the password given. This
solves the chicken-and-egg problem of how to authenticate and add entries
before any entries yet exist.

Slapd natively understands if you use a SHA-1 encrypted password on the
rootpw directive. I use a Java class that generates SHA-1 passwords, but it's
possible to use the command slappasswd to generate the passwords:
slappasswd -h {SHA}                                                          
rootpw    "{SHA}5en6G6MezRroT3XKqkdPOmY/BfQ="                                

For example:
        rootdn "cn=Manager,dc=example,dc=com"                                
        rootpw "{SHA}5en6G6MezRroT3XKqkdPOmY/BfQ="                           

The default output for slappasswd is to generate Secure Hash passwords
{SSHA}, in this case you don't need to pass the -h parameter, just call
slappasswd directly.

If you are using SASL as a mechanism to authenticate against LDAP, the rootpw
line may be discarded. Take a look on the Section 3.4 and on the Section 6.2
for more details.

Finally, you should make sure that the database definition contains the index
definitions you want:
index {<attrlist> | default} [pres,eq,sub,none]                              

For example, to index the cn, sn, uid and objectclass attributes, the
following index configuration lines could be used.
index cn,sn,uid pres,eq,sub                                                  
index objectClass pres,eq                                                    

Note: Note that not all index types are available with all attribute types.
Take a look on the Section 3.6 for examples.

Once you have configured things to your liking, start up slapd, connect with
your LDAP client, and start adding entries. For example, to add the TUDelft
entry followed by a Postmaster entry using the ldapadd tool, you could create
a file called /tmp/newentry with the contents:
o=TUDelft, c=NL                                                              
description=Technical University of Delft Netherlands                        
cn=Postmaster, o=TUDelft, c=NL                                               
description= TUDelft postmaster -                      

and then use a command like this to actually create the entry:
ldapadd -f /tmp/newentry -x -D "cn=Manager, o=TUDelft, c=NL" -w secret       

The above command assumes that you have set rootdn to "cn=Manager, o=TUDelft,
c=NL" and rootpw to "secret" (maybe SHA-1 encrypted in slapd.conf). If you
don't want to type the password on the command line, use the -W option for
the ldapadd command instead of -w "password". You will be prompted to enter
the password:
ldapadd -f /tmp/newentry -x -D "cn=Manager, o=TUDelft, c=NL" -W              
Enter LDAP Password:                                                         

5.2. Creating a Database offline

The second method of database creation is to do it off-line, using the slapd
database tools described below. This method is best if you have many
thousands of entries to create, which would take an unacceptably long time
using the LDAP method described above. These tools read the slapd
configuration file and an input LDIF file containing a text representation of
the entries to add. For database types which support the tools, they produce
the database files directly (otherwise you must use the on-line method
above). There are several important configuration options you will want to be
sure and set in the config file database definition first:
suffix <dn>                                                                  

As described in the preceding section, this option says which entries are to
be held by this database. You should set this to the DN of the root of the
subtree you are trying to create. For example:
suffix "o=TUDelft, c=NL"                                                     

You should be sure to specify a directory where the index files should be
directory /usr/local/tudelft                                                 

Finally, you need to specify which indexes you want to build. This is done by
one or more index options.
index {<attrlist> | default } [pres,eq,approx,sub,none]                      

For example:
index cn,sn,uid pres,eq,sub                                                  
index objectClass eq                                                         

This would create presence, equality and substring indexes for the cn, sn,
and uid attributes and an equality index for the objectClass attribute. See
the configuration file section for more information on this option.

Once you've configured things to your liking, you create the primary database
and associated indexes by running the slapadd(8) program:
slapadd -l <inputfile> -f <slapdconfigfile> [-d <debuglevel>]                
 [-n <integer>|-b <suffix>]                                                  

The arguments have the following meanings:
-l <inputfile>                                                               

Specifies the LDIF input file containing the entries to add in text form
(Take a look on the next section).
-f <slapdconfigfile>                                                         

Specifies the slapd configuration file that tells where to create the
indexes, what indexes to create, etc.
-d <debuglevel>                                                              

Turn on debugging, as specified by <debuglevel>. The debug levels are the
same as for slapd. See the Section 4.1 for more details.
-n <databasenumber>                                                          

An optional argument that specifies which database to modify. The first
database listed in the configuration file is 1, the second 2, etc. By
default, the first database in the configuration file is used. Should not be
used in conjunction with -b.
-b <suffix>                                                                  

An optional argument that specifies which database to modify. The provided
suffix is matched against a database suffix directive to determine the
database number. Should not be used in conjunction with -n.

Sometimes it may be necessary to regenerate indices (such as after modifying
slapd.conf(5)). This is possible using the slapindex(8) program. slapindex is
invoked like this:
slapindex -f <slapdconfigfile> [-d <debuglevel>] [-n <databasenumber>|-b <suffix>]

Where the -f, -d, -n and -b options are the same as for the slapadd(1)
program. slapindex rebuilds all indices based upon the current database

The slapcat program is used to dump the database to an LDIF file. This can be
useful when you want to make a human-readable backup of your database or when
you want to edit your database off-line. The program is invoked like this:
slapcat -l <filename> -f <slapdconfigfile> [-d <debuglevel>] [-n <databasenumber>|-b <suffix>]

where -n or -b is used to select the database in the slapd.conf(5) specified
using -f. The corresponding LDIF output is written to standard output or to
the file specified using the -l option.

5.3. More on the LDIF Format

The LDAP Data Interchange Format (LDIF) is used to represent LDAP entries in
a simple text format. The basic form of an entry is:
dn: <distinguished name>                                                     
<attrdesc>: <attrvalue>                                                      
<attrdesc>: <attrvalue>                                                      

Lines starting with a '#' character are comments. An attribute description
(attrdesc) may be a simple attribute type like cn or objectClass or 1.2.3 (an
OID associated with an attribute type) or may include options such as cn;
lang_en_US or userCertificate;binary.

A line may be continued by starting the next line with a single space or tab
character. For example:
dn: cn=Barbara J Jensen, dc=example, dc=                                     
cn: Barbara J                                                                

is equivalent to:
dn: cn=Barbara J Jensen, dc=example, dc=com                                  
cn: Barbara J Jensen                                                         

Multiple attribute values are specified on separate lines. e.g.,
cn: Barbara J Jensen                                                         
cn: Babs Jensen                                                              

If an <attrvalue> contains non-printing characters or begins with a space, a
double colon (':'), or a less than ('<'), the <attrdesc> is followed by a
double colon and the base64 encoding of the value. For example, the value "
begins with a space" would be encoded like this:
cn:: IGJlZ2lucyB3aXRoIGEgc3BhY2U=                                            

You can also specify a URL containing the attribute value. For example, the
following specifies the jpegPhoto value should be obtained from the file /
cn:< file://path/to/file.jpeg                                                

Multiple entries within the same LDIF file are separated by blank lines.
Here's an example of an LDIF file containing three entries.
# Barbara's Entry                                                            
dn: cn=Barbara J Jensen, dc=example, dc=com                                  
cn: Barbara J Jensen                                                         
cn: Babs Jensen                                                              
objectClass: person                                                          
sn: Jensen                                                                   
# Bjorn's Entry                                                              
dn: cn=Bjorn J Jensen, dc=example, dc=com                                    
cn: Bjorn J Jensen                                                           
cn: Bjorn Jensen                                                             
objectClass: person                                                          
sn: Jensen                                                                   
# Base64 encoded JPEG photo                                                  
jpegPhoto:: /9j/4AAQSkZJRgABAAAAAQABAAD/2wBDABALD                            
# Jennifer's Entry                                                           
dn: cn=Jennifer J Jensen, dc=example, dc=com                                 
cn: Jennifer J Jensen                                                        
cn: Jennifer Jensen                                                          
objectClass: person                                                          
sn: Jensen                                                                   
# JPEG photo from file                                                       
jpegPhoto:< file://path/to/file.jpeg                                         

Notice that the jpegPhoto in Bjorn's entry is base 64 encoded and the
jpegPhoto in Jennifer's entry is obtained from the location indicated by the

Trailing spaces are not trimmed from values in an LDIF file. Nor are multiple
internal spaces compressed. If you don't want them in your data, don't put
them there.

5.4. The ldapsearch, ldapdelete and ldapmodify utilities

ldapsearch - ldapsearch is a shell accessible interface to the ldap_search(3)
library call. Use this utility to search for entries on your LDAP database

The synopsis to call ldapsearch is the following (take a look at the
ldapsearch man page to see what each option means):
ldapsearch  [-n]  [-u]  [-v]  [-k]                                           
[-K]  [-t]  [-A] [-B] [-L]                                                   
[-R] [-d debuglevel] [-F sep] [-f file]                                      
[-x] [-D binddn]  [-W]  [-w bindpasswd]                                      
[-h ldaphost]  [-p ldapport]   [-b searchbase]                               
[-s base|one|sub]                                                            
[-a never|always|search|find] [-l timelimit]                                 
[-z sizelimit] filter [attrs...]                                             

ldapsearch opens a connection to an LDAP server, binds, and performs a search
using the filter filter. The filter should conform to the string
representation for LDAP filters as defined in RFC 1558. If ldapsearch finds
one or more entries, the attributes specified by attrs are retrieved and the
entries and values are printed to standard output. If no attrs are listed,
all attributes are returned.
ldapsearch -x -b 'o=TUDelft,c=NL' 'objectclass=*'                            
ldapsearch -b 'o=TUDelft,c=NL' 'cn=Rene van Leuken'                          
ldasearch -u -b 'o=TUDelft,c=NL' 'cn=Luiz Malere' sn mail                    

The -b option stands for searchbase (initial search point), the -u option
stands for userfriendly output information and the -x option is used to
specify simple authentication.

ldapdelete - ldapdelete is a shell accessible interface to the ldap_delete(3)
library call. Use this utility to delete entries on our LDAP database

The synopsis to call ldapdelete is the following (take a look at the
ldapdelete man page to see what each option means):
ldapdelete   [-n]   [-v]  [-k]  [-K]                                         
[-c]  [-d debuglevel]  [-f file]  [-D binddn]                                
[-W]  [-w passwd] [-h ldaphost] [-p ldapport]                                

ldapdelete opens a connection to an LDAP server, binds, and deletes one or
more entries. If one or more dn arguments are provided, entries with those
Distinguished Names are deleted. Each dn should be a string-represented DN as
defined in RFC 1779. If no dn arguments are provided, a list of DNs is read
from standard input (or from file if the -f flag is used).

Here are some examples of the use of ldapdelete:
ldapdelete 'cn=Luiz Malere,o=TUDelft,c=NL'                                               
ldapdelete -v 'cn=Rene van Leuken,o=TUDelft,c=NL' -D 'cn=Luiz Malere,o=TUDelft,c=NL' -W  

The -v option stands for verbose mode, the -D option stands for Binddn (the
dn to authenticate against) and the -W option stands for password prompt.

ldapmodify - ldapmodify is a shell accessible interface to the ldap_modify(3)
and ldap_add(3) library calls. Use this utility to modify entries on our LDAP
database backend.

The synopsis to call ldapmodify is the following (take a look at the
ldapmodify man page to see what each option mean):
ldapmodify   [-a]  [-b]  [-c]  [-r]                                          
[-n]  [-v]  [-k]  [-d debuglevel]                                            
[-D binddn]  [-W]  [-w passwd]                                               
[-h ldaphost] [-p ldapport] [-f file]                                        
ldapadd [-b] [-c] [-r] [-n]                                                  
[-v]  [-k]  [-K]  [-d debuglevel]                                            
[-D binddn]  [-w passwd]  [-h ldaphost]                                      
[-p ldapport] [-f file]                                                      

ldapadd is implemented as a hard link to the ldapmodify tool. When invoked as
ldapadd the -a (add new entry) flag of ldapmodify is turned on automatically.
ldapmodify opens a connection to an LDAP server, binds, and modifies or adds
entries. The entry information is read from standard input or from file
through the use of the -f option.

Here are some examples of the use of ldapmodify:

Assuming that the file /tmp/entrymods exists and has the contents:
dn: cn=Modify Me, o=University of Michigan, c=US                             
changetype: modify                                                           
replace: mail                                                                
add: title                                                                   
title: Grand Poobah                                                          
add: jpegPhoto                                                               
jpegPhoto: /tmp/modme.jpeg                                                   
delete: description                                                          

The command:
ldapmodify -b -r -f /tmp/entrymods                                           

will replace the contents of the "Modify Me" entry's mail attribute with the
value "", add a title of "Grand Poobah", and
the contents of the file /tmp/modme.jpeg as a jpegPhoto, and completely
remove the description attribute.

The same modifications as above can be performed using the older ldapmodify
input format:
cn=Modify Me, o=University of Michigan, c=US                                                               
+title=Grand Poobah                                                          

And plus the command bellow:
ldapmodify -b -r -f /tmp/entrymods                                           

Assuming that the file /tmp/newentry exists and has the contents:
dn: cn=Barbara Jensen, o=University of Michigan, c=US                        
objectClass: person                                                          
cn: Barbara Jensen                                                           
cn: Babs Jensen                                                              
sn: Jensen                                                                   
title: the world's most famous manager                                       
uid: bjensen                                                                 

The command:
ldapadd -f /tmp/entrymods                                                    

will add the entry with dn: cn=Barbara Jensen, o=University of Michigan, c=US
if it's not already present. If an entry with this dn already exists, the
command will point out the error and will not overwrite the entry.

Assuming that the file /tmp/newentry exists and has the contents:
dn: cn=Barbara Jensen, o=University of Michigan, c=US                        
changetype: delete                                                           

The command:
ldapmodify -f /tmp/entrymods                                                 

will remove Babs Jensen's entry.

The -f option stands for file (read the modification information from a file
instead of standard input), the -b option stands for binary (any values
starting with a '/' on the input file are interpreted as binaries), the -r
stands for replace (replace existing values by default).

Chapter 6. Additional Information and Features

In this section you will find additional information and useful references
for topics like authentication, logs and LDAP clients. At the end of the
section there are also some very nice generic URL's and book recomendations
about the subject LDAP.

6.1. LDAP Migration Tools

The LDAP Migration Tools are a collection of Perl scripts provided by PADL
Software Ltd. They are used to convert configuration files to the LDIF
format. I recommend reading the license terms before using them, even being
free. If you plan to use your LDAP server to authenticate users, this tools
may be very useful. Use the Migration Tools to convert your NIS or password
archives to the LDIF format, making these files compatible with your LDAP
Server. Also apply these Perl scripts to migrate users, groups, aliases,
hosts, netgroups, networks, protocols, RPCs and services from existing
nameservices (NIS, flat files and NetInfo) to the LDIF format.

To download the LDAP Migration Tools and get more information, go to the
following address: []
tools.html .

The package comes with a README file and the name of the script files are
intuitive. Take a first look on the README file and then start applying the

Another recommended URL with migration tools is:


6.2. Authentication using LDAP

To access the LDAP service, the LDAP client first must authenticate itself to
the service. That is, it must tell the LDAP server who is going to be
accessing the data so that the server can decide what the client is allowed
to see and do. If the client authenticates successfully to the LDAP server,
then when the server subsequently receives a request from the client, it will
check whether the client is allowed to perform the request. This process is
called access control.

In LDAP, authentication is supplied in the "bind" operation. Ldapv3 supports
three types of authentication: anonymous, simple and SASL authentication. A
client that sends a LDAP request without doing a "bind" is treated as an
anonymous client. Simple authentication consists of sending the LDAP server
the fully qualified DN of the client (user) and the client's clear-text
password. This mechanism has security problems because the password can be
read from the network. To avoid exposing the password in this way, you can
use the simple authentication mechanism within an encrypted channel (such as
SSL), provided that this is supported by the LDAP server.

Finally, SASL is the Simple Authentication and Security Layer (RFC 2222). It
specifies a challenge-response protocol in which data is exchanged between
the client and the server for the purposes of authentication and
establishment of a security layer on which to carry out subsequent
communication. By using SASL, LDAP can support any type of authentication
agreed upon by the LDAP client and server. The Cyrus-SASL package is
available at the following URL: [

Further on authenticating users to access information from your Directory
Tree, your LDAP server can authenticate users from other services too
(Sendmail, Login, Ftp, etc.). This is accomplished migrating specific user
information to your LDAP server and using a mechanism called PAM (Pluggable
Authentication Module). The authentication module for LDAP is available as a
tar ball on the following address: []

6.3. SASL Configuration: Digest-MD5

I've got LDAP-SASL authentication running using the DIGEST-MD5 mechanism. To
accomplish that, I've followed strictly the steps listed bellow:

��*�Downloaded SleepyCat 4.2.52, compiling and building manually. After
    downloading, I've just followed the instructions listed on the file docs/
    index.html under the directory where I've unpacked the .tar.gz bundle.
    After unpacking you can run the suggested:
    root@rdnt03:/usr/local/BerkeleyDB.4.2/build_unix#make install            
��*�Downloaded Cyrus SASL 2.1.17, unpacking and following the instructions
    listed on the document doc/install.html, under the directory where I've
    unpacked the .tar.gz file. Here there's a point of attention, you need to
    run the configure script using some env parameters:
    root@rdnt03:/usr/local/cyrus-sasl-2.1.17#env CPPFLAGS="-I/usr/local/BerkeleyDB.4.2/include" 
    LDFLAGS="-L/usr/local/BerkeleyDB.4.2/lib" ./configure                                       
    The CPPFLAGS and LDFLAGS environment parameters should point to the
    respective include and lib directories where Berkeley BDB was installed.
    After that you can run the suggested:
    root@rdnt03:/usr/local/cyrus-sasl-2.1.17#make install                             
    root@rdnt03:/usr/local/cyrus-sasl-2.1.17#ln -s /usr/local/lib/sasl2 /usr/lib/sasl2
��*�Finally, I've installed OpenLDAP 2.2.5 using the same directions listed
    on this document, just running the configure script the same way as
    SASL's configure:
    root@rdnt03:/usr/local/openldap-2.2.5#env CPPFLAGS="-I/usr/local/BerkeleyDB.4.2/include" 
    LDFLAGS="-L/usr/local/BerkeleyDB.4.2/lib" ./configure                                    
    After that, I've run the suggested:
    root@rdnt03:/usr/local/openldap-2.2.5#make depend                        
    root@rdnt03:/usr/local/openldap-2.2.5#make install                       
��*�Next, I've created the sasl user database:
    root@rdnt03:~# saslpasswd2 -c admin                                      
    You'll be prompted for a password. Remember that the username should not
    be a DN (distinguished name). Also remember to use the same password as
    your admin entry on the directory tree.
��*�Now, you should set the sasl-regexp directive in the slapd.conf file
    before starting the slapd daemon and testing the authentication. My 
    slapd.conf file resides at /usr/local/etc/openldap:
    sasl-regexp uid=(.*),cn=rdnt03,cn=DIGEST-MD5,cn=auth uid=$1,ou=People,o=Ever
    This parameter is in the format of:
    The username is taken from sasl and inserted into the ldap search string
    in the place of $1.Your realm is supposed to be your FQDN (fully
    qualified domain name), but in some cases it isn't, like mine. To find
    out what your realm is do:
    root@rdnt03:~# sasldblistusers2                                          
    admin@rdnt03: userPassword                                               
    admin@rdnt03: cmusaslsecretOTP                                           
    In my case, rdnt03 is indicated as the realm. If it is your FQDN you
    shouldn't have any problems. I use the following LDIF file:
    dn: o=Ever                                                                           
    o: Ever                                                                              
    description: Organization Root                                                       
    objectClass: top                                                                     
    objectClass: organization                                                            
    dn: ou=Staff, o=Ever                                                                 
    ou: Staff                                                                            
    description: These are privileged users that can interact with Organization products 
    objectClass: top                                                                     
    objectClass: organizationalUnit                                                      
    dn: ou=People, o=Ever                                                                
    ou: People                                                                           
    objectClass: top                                                                     
    objectClass: organizationalUnit                                                      
    dn: uid=admin, ou=Staff, o=Ever                                                      
    uid: admin                                                                           
    cn: LDAP Adminstrator                                                                
    sn: admin                                                                            
    userPassword: {SHA}5en6G6MezRroT3XKqkdPOmY/BfQ=                                      
    objectClass: Top                                                                     
    objectClass: Person                                                                  
    objectClass: Organizationalperson                                                    
    objectClass: Inetorgperson                                                           
    dn: uid=admin,ou=People,o=Ever                                                       
    objectClass: top                                                                     
    objectClass: person                                                                  
    objectClass: organizationalPerson                                                    
    objectClass: inetOrgPerson                                                           
    userPassword: {SHA}5en6G6MezRroT3XKqkdPOmY/BfQ=                                      
    displayName: admin                                                                   
    uid: admin                                                                           
    cn: Administrator                                                                    
    sn: admin                                                                            
    Add the entries to your LDAP directory using the following command:
    slapadd -c -l Ever.ldif -f slapd.conf -v -d 256                          
��*�Now, start the slapd daemon and run a query using the ldapsearch command:
    root@rdnt03:~# ldapsearch -U admin@rdnt03 -b 'o=Ever' '(objectclass=*)'  
    SASL/DIGEST-MD5 authentication started                                   
    Please enter your password:                                              
    SASL username: admin@rdnt03                                              
    SASL SSF: 128                                                            
    SASL installing layers                                                   

That's it ! If you prefer to use SASL with Kerberos V or GSSAPI, there's a
useful link at [] http:// This link assumes you've already
managed to install and configure the SASL library. The mailing lists will
help you get going with this matter: [

6.4. Graphical LDAP tools

Kldap is a graphical LDAP client written for KDE. Kldap has a nice interface
and is able to show all the information tree stored on your Directory. You
can check some screenshots of the application and download it at: [http://]

KDirAdm is a LDAP Directory management tool written for the KDE Desktop
Environment version 2 or later. It aims to provide all of the functionality
of most commercial directory management tools: [

Directory Administrator is the most widely used GNOME application for
managing UNIX users and groups on LDAP directory servers. Directory
administrator allows you to create and delete users and groups, and manage
your users associated address book information, per-server access controls
and Sendmail mail routing: [] http://

GQ is another graphical LDAP client with a simpler interface. It was written
for GNOME. It also runs under KDE, the same way Kldap runs under GNOME. The
address for downloading and getting more information is: [

LDAP Browser/Editor: This tool is fantastic, it has complete administrative
and browsing funcionalities. Check it out: [
/] Ldap Browser.

6.5. Logs

Slapd uses the syslog(8) facility to generate logs. The default user of the
syslog(8) facility is LOCAL4, but values from LOCAL0, LOCAL1, up to LOCAL7
are allowed.

In order to enable the generation of logs you have to edit your syslog.conf
file, usually located in the /etc directory.

Create a line like this:
local4.*     /usr/adm/ldaplog                                                

This will use the default user LOCAL4 for the syslog facility. If you are not
familiar with the syntax of this line, take a look at the man pages of
syslog, syslog.conf and syslogd. If you want to specify the level of the logs
generated or to change the default user, you have the following options while
starting slapd:
-s syslog-level                                                              

This option tells slapd at what level debugging statements should be logged
to the syslog(8) facility. The level describes the severity of the message,
and is a keyword from the following ordered list (higher to lower): emerg,
alert, crit, err, warning, notice, info, and debug. Ex: slapd -f myslapd.conf
-s debug
-l syslog-local-user                                                         

Selects the local user of the syslog(8) facility. Values can be LOCAL0,
LOCAL1, and so on, up to LOCAL7. The default is LOCAL4. However, this option
is only permitted on systems that support local users with the syslog(8)

Now take a look at the logs generated (/usr/adm/ldaplog in the example). They
can help you tremendously in solving problems with queries, updates, binding,

Chapter 7. References

On this section you will find additional documentation about LDAP: useful
URLs, cool books and definition RFCs.

7.1. URL's

Here are the URLs that contain very useful information about LDAP. From these
URLs, this HOWTO was made, so if after reading this document you need more
specific information, you probably will find here:

��*�University of Michigan LDAP Page: []
��*�University of Michigan LDAP Documentation Page: [
��*�OpenLDAP Administrator's Guide (brother document): [http://]
��*�Linux Directory Service: []
��*�Red Hat and LDAP: [
��*�Mandrake Linux - Using OpenLDAP for Authentication: [http://] http://
��*�Integrating OpenLDAP with other Open Source projects: [ftp://]

7.2. Books

These are the most popular and useful books about LDAP:

��*�Implementing LDAP by Mark Wilcox
��*�LDAP: Programming Directory-Enabled Applications with Lightweight
    Directory Access Protocol by Howes and Smith
��*�Understanding and Deploying LDAP Directory Servers by Howes, Smith, and

7.3. RFC's

The [] RFCs that support the LDAP development

��*�RFC 1558: A String Representation of LDAP Search Filters
��*�RFC 1777: Lightweight Directory Access Protocol
��*�RFC 1778: The String Representation of Standard Attribute Syntaxes
��*�RFC 1779: A String Representation of Distinguished Names
��*�RFC 1781: Using the OSI Directory to Achieve User Friendly Naming
��*�RFC 1798: Connectionless LDAP
��*�RFC 1823: The LDAP Application Programming Interface
��*�RFC 1959: An LDAP URL Format
��*�RFC 1960: A String Representation of LDAP Search Filters
��*�RFC 2251: Lightweight Directory Access Protocol (v3)
��*�RFC 2307: LDAP as a Network Information Service

  All copyrights belong to their respective owners. Other site content (c) 2014, GNU.WIKI. Please report any site errors to