Preface
Copyright
Copyright 1998-2002, The OpenLDAP Foundation, All Rights Reserved.
Copyright 1992-1996, Regents of the University of Michigan, All Rights Reserved.
This document is considered a part of OpenLDAP Software. This document is subject to terms of conditions set forth in OpenLDAP Software Copyright Notices and the OpenLDAP Public License. Complete copies of the notices and associated license can be found in Appendix B and C, respectively.
Scope of this Document
This document provides a guide for installing OpenLDAP 2.2 Software (http://www.openldap.org/software/) on
This document is meant to be used in conjunction with other OpenLDAP information resources provided with the software package and on the project's extensive site (http://www.OpenLDAP.org/) on the World Wide Web. The site makes available a number of resources.
| Resource | URL |
| Document Catalog | http://www.OpenLDAP.org/doc/ |
| Frequently Asked Questions | http://www.OpenLDAP.org/faq/ |
| Issue Tracking System | http://www.OpenLDAP.org/its/ |
| Mailing Lists | http://www.OpenLDAP.org/lists/ |
| Software Pages | http://www.OpenLDAP.org/software/ |
| Support Pages | http://www.OpenLDAP.org/support/ |
Acknowledgments
The OpenLDAP Project is comprised of a team of volunteers. This document would not be possible without their contribution of time and energy.
The OpenLDAP Project would also like to thank the University of Michigan LDAP for building the foundation of LDAP software and information to which OpenLDAP Software is built upon. This document is based upon U-Mich LDAP document: The SLAPD and SLURPD Administrators Guide.
Amendments
Suggested enhancements and corrections to this document should be submitted using the OpenLDAP
About this document
This document was produced using the Simple Document Format (http://search.cpan.org/src/IANC/sdf-2.001/doc/) documentation system developed by Ian Clatworthy. Tools for SDF are available from CPAN (http://search.cpan.org/search?query=SDF).
1. Introduction to OpenLDAP Directory Services
This document describes how to build, configure, and operate OpenLDAP software to provide directory services. This includes details on how to configure and run the stand-alone
1.1. What is a directory service?
A directory is a specialized database optimized for reading, browsing and searching. Directories tend to contain descriptive, attribute-based information and support sophisticated filtering capabilities. Directories generally do not support complicated transaction or roll-back schemes found in database management systems designed for handling high-volume complex updates. Directory updates are typically simple all-or-nothing changes, if they are allowed at all. 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 okay, 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 (e.g., the entire Internet). Global services are usually distributed, meaning that the data they contain is spread across many machines, all of which cooperate to provide the directory service. Typically a global service defines a uniform namespace which gives the same view of the data no matter where you are in relation to the data itself. The Internet
1.2. What is LDAP?
What kind of information can be stored in the directory? The LDAP information model is based on entries. An entry is a collection of attributes that has a globally-unique
How is the information arranged? In LDAP, directory entries are arranged in a hierarchical tree-like structure. Traditionally, this structure reflected the geographic and/or organizational boundaries. Entries representing countries appear at the top of the tree. Below them are entries representing states and national organizations. Below them might be entries representing organizational units, people, printers, documents, or just about anything else you can think of. Figure 1.1 shows an example LDAP directory tree using traditional naming.
Figure 1.1: LDAP directory tree (traditional naming)
The tree may also be arranged based upon Internet domain names. This naming approach is becoming increasing popular as it allows for directory services to be located using the DNS. Figure 1.2 shows an example LDAP directory tree using domain-based naming.
Figure 1.2: LDAP directory tree (Internet naming)
In addition, LDAP allows you to control which attributes are required and allowed in an entry through the use of a special attribute called objectClass. The values of the objectClass attribute determine the schema rules the entry must obey.
How is the information referenced? An entry is referenced by its distinguished name, which is constructed by taking the name of the entry itself (called the
How is the information accessed? LDAP defines operations for interrogating and updating the directory. Operations are provided for adding and deleting an entry from the directory, changing an existing entry, and changing the name of an entry. Most of the time, though, LDAP is used to search for information in the directory. The LDAP search operation allows some portion of the directory to be searched for entries that match some criteria specified by a search filter. Information can be requested from each entry that matches the criteria.
For example, you might want to search the entire directory subtree at and below dc=example,dc=com for people with the name Barbara Jensen, retrieving the email address of each entry found. LDAP lets you do this easily. Or you might want to search the entries directly below the st=California,c=US entry for organizations with the string Acme in their name, and that have a fax number. LDAP lets you do this too. The next section describes in more detail what you can do with LDAP and how it might be useful to you.
How is the information protected from unauthorized access? Some directory services provide no protection, allowing anyone to see the information. LDAP provides a mechanism for a client to authenticate, or prove its identity to a directory server, paving the way for rich access control to protect the information the server contains. LDAP also supports privacy and integrity security services.
1.3. 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 directory information tree (DIT). The client connects to servers and asks it a question. The server responds with an answer and/or with a pointer to where the client can get additional information (typically, another LDAP server). No matter which 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.
1.4. What about X.500?
Technically,
While LDAP is still used to access X.500 directory service via gateways, LDAP is now more commonly directly implemented in X.500 servers.
The stand-alone LDAP daemon, or slapd(8), can be viewed as a lightweight X.500 directory server. That is, it does not implement the X.500's DAP. As a lightweight directory server, slapd(8) implements only a subset of the X.500 models.
If you are already running a X.500 DAP service and you want to continue to do so, you can probably stop reading this guide. This guide is all about running LDAP via slapd(8), without running X.500 DAP. If you are not running X.500 DAP, want to stop running X.500 DAP, or have no immediate plans to run X.500 DAP, read on.
It is possible to replicate data from an LDAP directory server to a X.500 DAP
1.5. What is the difference between LDAPv2 and LDAPv3?
LDAPv3 was developed in the late 1990's to replace LDAPv2. LDAPv3 adds the following features to LDAP:
- Strong Authentication via
SASL - Integrity and Confidentiality Protection via
TLS (SSL) - Internationalization through the use of Unicode
- Referrals and Continuations
- Schema Discovery
- Extensibility (controls, extended operations, and more)
LDAPv2 is historic (RFC3494). As most implementations (including slapd(8)) of LDAPv2 do not conform to the LDAPv2 technical specification, interoperatibility amongst implementations claiming LDAPv2 support will be limited. As LDAPv2 differs significantly from LDAPv3, deploying both LDAPv2 and LDAPv3 simultaneously can be quite problematic. LDAPv2 should be avoided. LDAPv2 is disabled by default.
1.6. What is slapd and what can it do?
slapd(8) is an LDAP directory server that runs on many different platforms. You can use it to provide a directory service of your very own. Your directory can contain pretty much anything you want to put in it. You can connect it to the global LDAP directory service, or run a service all by yourself. Some of slapd's more interesting features and capabilities include:
LDAPv3: slapd implements version 3 of
Topology control: slapd can be configured to restrict access at the socket layer based upon network topology information. This feature utilizes TCP wrappers.
Access control: slapd provides a rich and powerful access control facility, allowing you to control access to the information in your database(s). You can control access to entries based on LDAP authorization information,
Internationalization: slapd supports Unicode and language tags.
Choice of database backends: slapd comes with a variety of different database backends you can choose from. They include
Multiple database instances: slapd can be configured to serve multiple databases at the same time. This means that a single slapd server can respond to requests for many logically different portions of the LDAP tree, using the same or different database backends.
Generic modules API: If you require even more customization, slapd lets you write your own modules easily. slapd consists of two distinct parts: a front end that handles protocol communication with LDAP clients; and modules which handle specific tasks such as database operations. Because these two pieces communicate via a well-defined
Threads: slapd is threaded for high performance. A single multi-threaded slapd process handles all incoming requests using a pool of threads. This reduces the amount of system overhead required while providing high performance.
Replication: slapd can be configured to maintain shadow copies of directory information. This single-master/multiple-slave replication scheme is vital in high-volume environments where a single slapd just doesn't provide the necessary availability or reliability. slapd also includes experimental support for multi-master replication (for use where strong ACID properties are not required). slapd supports two replication methods: LDAP Sync-based and slurpd(8)-based replication .
Proxy Cache: slapd can be configured as a caching LDAP proxy service.
Configuration: slapd is highly configurable through a single configuration file which allows you to change just about everything you'd ever want to change. Configuration options have reasonable defaults, making your job much easier.
1.7. What is slurpd and what can it do?
slurpd(8) is a daemon that, with slapd help, provides replicated service. It is responsible for distributing changes made to the master slapd database out to the various slapd replicas. It frees slapd from having to worry that some replicas might be down or unreachable when a change comes through; slurpd handles retrying failed requests automatically. slapd and slurpd communicate through a simple text file that is used to log changes.
See the Replication with slurpd chapter for information about how to configure and run slurpd(8).
Alternatively, LDAP-Sync-based replication may be used to provide a replicated service. See the LDAP Sync Replication chapter for details.
2. A Quick-Start Guide
The following is a quick start guide to OpenLDAP 2.2 software, including the stand-alone LDAP daemon, slapd(8).
It is meant to walk you through the basic steps needed to install and configure OpenLDAP Software. It should be used in conjunction with the other chapters of this document, manual pages, and other materials provided with the distribution (e.g. the INSTALL document) or on the OpenLDAP web site (in particular, the OpenLDAP Software
If you intend to run OpenLDAP Software seriously, you should review all of this document before attempting to install the software.
Note: This quick start guide does not use strong authentication nor any integrity or confidential protection services. These services are described in other chapters of the OpenLDAP Administrator's Guide.
- Get the software
You can obtain a copy of the software by following the instructions on the OpenLDAP download page (http://www.openldap.org/software/download/). It is recommended that new users start with the latest release.
- Unpack the distribution
Pick a directory for the source to live under, change directory to there, and unpack the distribution using the following commands:-
gunzip -c openldap-VERSION.tgz | tar xvfB -
then relocate yourself into the distribution directory:-
cd openldap-VERSION
You'll have to replace VERSION with the version name of the release.
- Review documentation
You should now review the COPYRIGHT, LICENSE, README and INSTALL documents provided with the distribution. The COPYRIGHT and LICENSE provide information on acceptable use, copying, and limitation of warranty of OpenLDAP software.
You should also review other chapters of this document. In particular, the Building and Installing OpenLDAP Software chapter of this document provides detailed information on prerequisite software and installation procedures.
- Run configure
You will need to run the provided configure script to configure the distribution for building on your system. The configure script accepts many command line options that enable or disable optional software features. Usually the defaults are okay, but you may want to change them. To get a complete list of options that configure accepts, use the --help option:-
./configure --help
However, given that you are using this guide, we'll assume you are brave enough to just let configure determine what's best:-
./configure
Assuming configure doesn't dislike your system, you can proceed with building the software. If configure did complain, well, you'll likely need to go to the FAQ Installation Section (http://www.openldap.org/faq/ and/or actually read the Building and Installing OpenLDAP Software chapter of this document.
- Build the software.
The next step is to build the software. This step has two parts, first we construct dependencies and then we compile the software:-
make depend
make
Both makes should complete without error.
- Test the build.
To ensure a correct build, you should run the test suite (it only takes a few minutes):-
make test
Tests which apply to your configuration will run and they should pass. Some tests, such as the replication test, may be skipped.
- Install the software.
You are now ready to install the software; this usually requires super-user privileges:-
su root -c 'make install'
Everything should now be installed under /usr/local (or whatever installation prefix was used by configure).
- Edit the configuration file.
Use your favorite editor to edit the provided slapd.conf(5) example (usually installed as /usr/local/etc/openldap/slapd.conf) to contain a BDB database definition of the form:-
database bdb
suffix "dc=<MY-DOMAIN>,dc=<COM>"
rootdn "cn=Manager,dc=<MY-DOMAIN>,dc=<COM>"
rootpw secret
directory /usr/local/var/openldap-data
Be sure to replace <MY-DOMAIN> and <COM> with the appropriate domain components of your domain name. For example, for example.com, use:-
database bdb
suffix "dc=example,dc=com"
rootdn "cn=Manager,dc=example,dc=com"
rootpw secret
directory /usr/local/var/openldap-data
If your domain contains additional components, such as eng.uni.edu.eu, use:-
database bdb
suffix "dc=eng,dc=uni,dc=edu,dc=eu"
rootdn "cn=Manager,dc=eng,dc=uni,dc=edu,dc=eu"
rootpw secret
directory /usr/local/var/openldap-data
Details regarding configuring slapd(8) can be found in the slapd.conf(5) manual page and the The slapd Configuration File chapter of this document.
Note: the directory specified must exist prior to starting slapd(8).
- Start SLAPD.
You are now ready to start the stand-alone LDAP server, slapd(8), by running the command:-
su root -c /usr/local/libexec/slapd
To check to see if the server is running and configured correctly, you can run a search against it with ldapsearch(1). By default, ldapsearch is installed as /usr/local/bin/ldapsearch:-
ldapsearch -x -b '' -s base '(objectclass=*)' namingContexts
Note the use of single quotes around command parameters to prevent special characters from being interpreted by the shell. This should return:-
dn:
namingContexts: dc=example,dc=com
Details regarding running slapd(8) can be found in the slapd(8) manual page and the Running slapd chapter of this document.
- Add initial entries to your directory.
You can use ldapadd(1) to add entries to your LDAP directory. ldapadd expects input in LDIF form. We'll do it in two steps:- create an LDIF file
- run ldapadd
Use your favorite editor and create an LDIF file that contains:-
dn: dc=<MY-DOMAIN>,dc=<COM>
objectclass: dcObject
objectclass: organization
o: <MY ORGANIZATION>
dc: <MY-DOMAIN>
dn: cn=Manager,dc=<MY-DOMAIN>,dc=<COM>
objectclass: organizationalRole
cn: Manager
Be sure to replace <MY-DOMAIN> and <COM> with the appropriate domain components of your domain name. <MY ORGANIZATION> should be replaced with the name of your organization. When you cut and paste, be sure to trim any leading and trailing whitespace from the example.-
dn: dc=example,dc=com
objectclass: dcObject
objectclass: organization
o: Example Company
dc: example
dn: cn=Manager,dc=example,dc=com
objectclass: organizationalRole
cn: Manager
Now, you may run ldapadd(1) to insert these entries into your directory.-
ldapadd -x -D "cn=Manager,dc=<MY-DOMAIN>,dc=<COM>" -W -f example.ldif
Be sure to replace <MY-DOMAIN> and <COM> with the appropriate domain components of your domain name. You will be prompted for the "secret" specified in slapd.conf. For example, for example.com, use:-
ldapadd -x -D "cn=Manager,dc=example,dc=com" -W -f example.ldif
where example.ldif is the file you created above.
Additional information regarding directory creation can be found in the Database Creation and Maintenance Tools chapter of this document.
- See if it works.
Now we're ready to verify the added entries are in your directory. You can use any LDAP client to do this, but our example uses the ldapsearch(1) tool. Remember to replace dc=example,dc=com with the correct values for your site:-
ldapsearch -x -b 'dc=example,dc=com' '(objectclass=*)'
This command will search for and retrieve every entry in the database.
You are now ready to add more entries using ldapadd(1) or another LDAP client, experiment with various configuration options, backend arrangements, etc.
Note that by default, the slapd(8) database grants read access to everybody excepting the super-user (as specified by the rootdn configuration directive). It is highly recommended that you establish controls to restrict access to authorized users. Access controls are discussed in the Access Control section of The slapd Configuration File chapter. You are also encouraged to read the Security Considerations, Using SASL and Using TLS sections.
The following chapters provide more detailed information on making, installing, and running slapd(8).
3. The Big Picture - Configuration Choices
This section gives a brief overview of various
3.1. Local Directory Service
In this configuration, you run a slapd which provides directory service for your local domain only. It does not interact with other directory servers in any way. This configuration is shown in Figure 3.1.
Figure 3.1: Local service configuration.
Use this configuration if you are just starting out (it's the one the quick-start guide makes for you) or if you want to provide a local service and are not interested in connecting to the rest of the world. It's easy to upgrade to another configuration later if you want.
3.2. Local Directory Service with Referrals
In this configuration, you run a slapd which provides directory service for your local domain and configure it to return referrals to a superior service capable of handling requests outside your local domain. You may run this service yourself or use one provided to you. This configuration is shown in Figure 3.2.
Figure 3.2: Local service with referrals
Use this configuration if you want to provide local service and participate in the Global Directory.
3.3. Replicated Directory Service
The slurpd daemon is used to propagate changes from a master slapd to one or more slave slapds. An example master-slave configuration is shown in figure 3.3.
Figure 3.3: Replicated Directory Services
This configuration can be used in conjunction with either of the first two configurations in situations where a single slapd does not provide the required reliability or availability.
3.4. Distributed Local Directory Service
In this configuration, the local service is partitioned into smaller services, each of which may be replicated, and glued together with superior and subordinate referrals.
4. Building and Installing OpenLDAP Software
This chapter details how to build and install the OpenLDAP Software package including slapd(8), the stand-alone LDAP daemon and slurpd(8), the stand-alone update replication daemon. Building and installing OpenLDAP Software requires several steps: installing prerequisite software, configuring OpenLDAP Software itself, making, and finally installing. The following sections describe this process in detail.
4.1. Obtaining and Extracting the Software
You can obtain OpenLDAP Software from the project's download page at http://www.openldap.org/software/download/ or directly from the project's
The project makes available two series of packages for general use. The project makes releases as new features and bug fixes come available. Though the project takes steps to improve stablity of these releases, it is common for problems to arise only after release. The stable release is the latest release which has demonstrated stability through general use.
Users of OpenLDAP Software can choose, depending on their desire for the latest features versus demonstrated stability, the most appropriate series to install.
After downloading OpenLDAP Software, you need to extract the distribution from the compressed archive file and change your working directory to the top directory of the distribution:
-
gunzip -c openldap-VERSION.tgz | tar xf -
cd openldap-VERSION
You'll have to replace VERSION with the version name of the release.
You should now review the COPYRIGHT, LICENSE, README and INSTALL documents provided with the distribution. The COPYRIGHT and LICENSE provide information on acceptable use, copying, and limitation of warranty of OpenLDAP Software. The README and INSTALL documents provide detailed information on prerequisite software and installation procedures.
4.2. Prerequisite software
OpenLDAP Software relies upon a number of software packages distributed by third parties. Depending on the features you intend to use, you may have to download and install a number of additional software packages. This section details commonly needed third party software packages you might have to install. Note that some of these third party packages may depend on additional software packages. Install each package per the installation instructions provided with it.
4.2.1. Transport Layer Security
OpenLDAP clients and servers require installation of OpenSSL
OpenSSL is available from http://www.openssl.org/.
OpenLDAP Software will not be fully LDAPv3 compliant unless OpenLDAP's configure detects a usable OpenSSL installation.
4.2.2. Kerberos Authentication Services
OpenLDAP clients and servers support Kerberos-based authentication services. In particular, OpenLDAP supports the
Heimdal Kerberos is available from http://www.pdc.kth.se/heimdal/. MIT Kerberos is available from http://web.mit.edu/kerberos/www/.
Use of strong authentication services, such as those provided by Kerberos, is highly recommended.
4.2.3. Simple Authentication and Security Layer
OpenLDAP clients and servers require installation of Cyrus's SASL libraries to provide
Cyrus SASL is available from http://asg.web.cmu.edu/sasl/sasl-library.html. Cyrus SASL will make use of OpenSSL and Kerberos/GSSAPI libraries if preinstalled.
OpenLDAP Software will not be fully LDAPv3 compliant unless OpenLDAP's configure detects a usable Cyrus SASL installation.
4.2.4. Database Software
OpenLDAP's slapd(8) primary database backend,
Your operating system may provide Berkeley DB, version 4, in the base system or as an optional software component. If not, you'll have to obtain and install it yourself.
Berkeley DB is available from Sleepycat Software's download page http://www.sleepycat.com/download/. There are several versions available. At the time of this writing, the latest release, version 4.1, is recommended. This package is required if you wish to use the
OpenLDAP's slapd(8) LDBM backend supports a variety of data base managers including Berkeley DB and GDBM. GDBM is available from FSF's download site ftp://ftp.gnu.org/pub/gnu/gdbm/.
4.2.5. Threads
OpenLDAP is designed to take advantage of threads. OpenLDAP supports POSIX pthreads, Mach CThreads, and a number of other varieties. configure 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 http://www.openldap.org/faq/.
4.2.6. TCP Wrappers
slapd(8) 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.
4.3. Running configure
Now you should probably run the configure script with the --help option. This will give you a list of options that you can change when building OpenLDAP. Many of the features of OpenLDAP can be enabled or disabled using this method.
./configure --help
The configure script will also look at various environment variables for certain settings. These environment variables include:
| Variable | Description |
| CC | Specify alternative C Compiler |
| CFLAGS | Specify additional compiler flags |
| CPPFLAGS | Specify C Preprocessor flags |
| LDFLAGS | Specify linker flags |
| LIBS | Specify additional libraries |
Now run the configure script with any desired configuration options or environment variables.
[[env] settings] ./configure [options]
As an example, let's assume that we want to install OpenLDAP with BDB backend and TCP Wrappers support. By default, BDB is enabled and TCP Wrappers is not. So, we just need to specify --with-wrappers to include TCP Wrappers support:
./configure --with-wrappers
However, this will fail to locate dependent software not installed in system directories. For example, if TCP Wrappers headers and libraries are installed in /usr/local/include and /usr/local/lib respectively, the configure script should be called as follows:
env CPPFLAGS="-I/usr/local/include" LDFLAGS="-L/usr/local/lib" \
./configure --with-wrappers
Note: Some shells, such as those derived from the Bourne sh(1), do not require use of the env(1) command. In some cases, environmental variables have to be specified using alternative syntaxes.
The configure script will normally auto-detect appropriate settings. If you have problems at this stage, consult any platform specific hints and check your configure options, if any.
4.4. Building the Software
Once you have run the configure script the last line of output should be:
Please "make depend" to build dependencies
If the last line of output does not match, configure has failed, and you will need to review its output to determine what went wrong. You should not proceed until configure completes successfully.
To build dependencies, run:
make depend
Now build the software, this step will actually compile OpenLDAP.
make
You should examine the output of this command carefully to make sure everything is built correctly. Note that this command builds the LDAP libraries and associated clients as well as slapd(8) and slurpd(8).
4.5. Testing the Software
Once the software has been properly configured and successfully made, you should run the test suite to verify the build.
make test
Tests which apply to your configuration will run and they should pass. Some tests, such as the replication test, may be skipped if not supported by your configuration.
4.6. Installing the Software
Once you have successfully tested the software, you are ready to install it. You will need to have write permission to the installation directories you specified when you ran configure. By default OpenLDAP Software is installed in /usr/local. If you changed this setting with the --prefix configure option, it will be installed in the location you provided.
Typically, the installation requires super-user privileges. From the top level OpenLDAP source directory, type:
su root -c 'make install'
and enter the appropriate password when requested.
You should examine the output of this command carefully to make sure everything is installed correctly. You will find the configuration files for slapd(8) in /usr/local/etc/openldap by default. See the chapter The slapd Configuration File for additional information.
5. The slapd Configuration File
Once the software has been built and installed, you are ready to configure slapd(8) for use at your site. The slapd runtime configuration is primarily accomplished through the slapd.conf(5) file, normally installed in the /usr/local/etc/openldap directory.
An alternate configuration file can be specified via a command-line option to slapd(8) or slurpd(8). This chapter describes the general format of the config file, followed by a detailed description of commonly used config file directives.
5.1. Configuration File Format
The slapd.conf(5) 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 backend and/or database directives, and 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 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.
5.2. Configuration File Directives
This section details commonly used configuration directives. For a complete list, see the slapd.conf(5) manual page. This section separates the configuration file directives into global, backend-specific and data-specific categories, describing each directive and its default value (if any), and giving an example of its use.
5.2.1. 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 <>.
5.2.1.1. 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 Access Control section of this chapter for a summary of basic usage.
Note: If no access directives are specified, the default access control policy, access to * by * read, allows all both authenticated and anonymous users read access.
5.2.1.2. attributetype <RFC2252 Attribute Type Description>
This directive defines an attribute type. Please see the Schema Specification chapter for information regarding how to use this directive.
5.2.1.3. 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.
5.2.1.4. 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 specifications.
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 done.
5.2.1.5. loglevel <integer>
This directive specifies the level at which debugging statements and operation statistics should be syslogged (currently logged to the syslogd(8) LOG_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:
| 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 |
Example:
loglevel -1
This will cause lots and lots of debugging information to be logged.
Default:
loglevel 256
5.2.1.6. objectclass <RFC2252 Object Class Description>
This directive defines an object class. Please see the Schema Specification chapter for information regarding how to use this directive.
5.2.1.7. referral <URI>
This directive specifies the referral to pass back when slapd cannot find a local database to handle a request.
Example:
referral ldap://root.openldap.org
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 part.
5.2.1.8. sizelimit <integer>
This directive specifies the maximum number of entries to return from a search operation.
Default:
sizelimit 500
5.2.1.9. 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.
Default:
timelimit 3600
5.2.2. 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.
5.2.2.1. backend <type>
This directive marks the beginning of a backend declaration. <type> should be one of the supported backend types listed in Table 5.2.
| Types | Description |
| bdb | Berkeley DB transactional backend |
| dnssrv | DNS SRV backend |
| ldap | Lightweight Directory Access Protocol (Proxy) backend |
| ldbm | Lightweight DBM backend |
| meta | Meta Directory backend |
| monitor | Monitor backend |
| passwd | Provides read-only access to passwd(5) |
| perl | Perl Programmable backend |
| shell | Shell (extern program) backend |
| sql | SQL Programmable backend |
Example:
backend bdb
This marks the beginning of a new
5.2.3. 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.
5.2.3.1. database <type>
This directive marks the beginning of a database instance declaration. <type> should be one of the supported backend types listed in Table 5.2.
Example:
database bdb
This marks the beginning of a new
5.2.3.2. 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.
Default:
readonly off
5.2.3.3. replica
replica uri=ldap[s]://<hostname>[:<port>] | host=<hostname>[:<port>]
[bindmethod={simple|kerberos|sasl}]
["binddn=<DN>"]
[saslmech=<mech>]
[authcid=<identity>]
[authzid=<identity>]
[credentials=<password>]
[srvtab=<filename>]
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.
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://slave.example.com:389 or ldaps://slave.example.com:636.
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
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.
See the chapter entitled Replication with slurpd for more information on how to use this directive.
5.2.3.4. 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.
See the chapter entitled Replication with slurpd for more information on how to use this directive.
5.2.3.5. 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 this database or even in the directory. The DN may refer to a SASL identity.
Entry-based Example:
rootdn "cn=Manager,dc=example,dc=com"
SASL-based Example:
rootdn "uid=root,cn=example.com,cn=digest-md5,cn=auth"
See the SASL Authentication section for information on SASL authentication identities.
5.2.3.6. rootpw <password>
This directive can be used to specifies a password for the DN for the rootdn (when the rootdn is set to a DN within the database).
Example:
rootpw secret
It is also permissible to provide hash of the password in RFC 2307 form. slappasswd(8) may be used to generate the password hash.
Example:
rootpw {SSHA}ZKKuqbEKJfKSXhUbHG3fG8MDn9j1v4QN
The hash was generated using the command slappasswd -s secret.
5.2.3.7. 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.
Example:
suffix "dc=example,dc=com"
Queries with a DN ending in "dc=example,dc=com" will be passed to this backend.
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.
5.2.3.8. syncrepl
syncrepl rid=<replica ID>
provider=ldap[s]://<hostname>[:port]
[type=refreshOnly|refreshAndPersist]
[interval=dd:hh:mm:ss]
[searchbase=<base DN>]
[filter=<filter str>]
[scope=sub|one|base]
[attrs=<attr list>]
[attrsonly]
[sizelimit=<limit>]
[timelimit=<limit>]
[schemachecking=on|off]
[updatedn=<DN>]
[bindmethod=simple|sasl]
[binddn=<DN>]
[saslmech=<mech>]
[authcid=<identity>]
[authzid=<identity>]
[credentials=<passwd>]
[realm=<realm>]
[secprops=<properties>]
This directive specifies the current database as a replica of the master content by establishing the current slapd(8) as a replication consumer site running a syncrepl replication engine. The master database is located at the replication provider site specified by the provider parameter. The replica database is kept up-to-date with the master content using the LDAP Content Synchronization protocol. See draft-zeilenga-ldup-sync-xx.txt (a work in progress) for more information on the protocol.
The rid parameter is used for identification of the current syncrepl directive within the replication consumer server, where <replica ID> uniquely identifies the syncrepl specification described by the current syncrepl directive. <replica ID> is non-negative and is no more than three decimal digits in length.
The provider parameter specifies the replication provider site containing the master content as an LDAP URI. The provider parameter specifies a scheme, a host and optionally a port where the provider slapd instance can be found. Either a domain name or IP address may be used for <hostname>. Examples are ldap://provider.example.com:389 or ldaps://192.168.1.1:636. If <port> is not given, the standard LDAP port number (389 or 636) is used. Note that the syncrepl uses a consumer-initiated protocol, and hence its specification is located at the consumer site, whereas the replica specification is located at the provider site. syncrepl and replica directives define two independent replication mechanisms. They do not represent the replication peers of each other.
The content of the syncrepl replica is defined using a search specification as its result set. The consumer slapd will send search requests to the provider slapd according to the search specification. The search specification includes searchbase, scope, filter, attrs, attrsonly, sizelimit, and timelimit parameters as in the normal search specification. The syncrepl search specification has the same value syntax and the same default values as in the ldapsearch(1) client search tool.
The LDAP Content Synchronization protocol has two operation types: refreshOnly and refreshAndPersist. The operation type is specified by the type parameter. In the refreshOnly operation, the next synchronization search operation is periodically rescheduled at an interval time after each synchronization operation finishes. The interval is specified by the interval parameter. It is set to one day by default. In the refreshAndPersist operation, a synchronization search remains persistent in the provider slapd. Further updates to the master replica will generate searchResultEntry to the consumer slapd as the search responses to the persistent synchronization search.
The schema checking can be enforced at the LDAP Sync consumer site by turning on the schemachecking parameter. If it is turned on, every replicated entry will be checked for its schema as the entry is stored into the replica content. Every entry in the replica should contain those attributes required by the schema definition. If it is turned off, entries will be stored without checking schema conformance. The default is off.
The updatedn parameter specifies the DN in the consumer site which is allowed to make changes to the replica. This DN is used locally by the syncrepl engine when updating the replica with the entries received from the provider site by using the internal operation mechanism. The update of the replica content is subject to the access control privileges of the DN. The DN should have read/write access to the replica database. Generally, this DN should not be the same as rootdn.
The binddn parameter gives the DN to bind as for the syncrepl searches to the provider slapd. It should be a DN which has read access to the replication content in the master database.
The bindmethod is simple or sasl, depending on whether simple password-based authentication or
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.
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.
The realm parameter specifies a realm which a certain mechanisms authenticate the identity within. The secprops parameter specifies Cyrus SASL security properties.
The syncrepl replication mechanism is supported by the three native backends: back-bdb, back-hdb, and back-ldbm.
See the LDAP Sync Replication chapter of the admin guide for more information on how to use this directive.
5.2.3.9. 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(8) 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=example.com,cn=digest-md5,cn=auth"
See the Replication with slurpd chapter for more information on how to use this directive.
5.2.3.10. 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
Example:
updateref ldap://master.example.net
5.2.4. BDB Database Directives
Directives in this category only apply to a
5.2.4.1. directory <directory>
This directive specifies the directory where the BDB files containing the database and associated indices live.
Default:
directory /usr/local/var/openldap-data
5.2.4.2. 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.
5.2.5. LDBM Database Directives
Directives in this category only apply to a
5.2.5.1. cachesize <integer>
This directive specifies the size in entries of the in-memory cache maintained by the LDBM backend database instance.
Default:
cachesize 1000
5.2.5.2. 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 indices.
Default:
dbcachesize 100000
5.2.5.3. dbnolocking
This option, if present, disables database locking. Enabling this option may improve performance at the expense of data security.
5.2.5.4. dbnosync
This option causes on-disk database contents to not be immediately synchronized with in memory changes upon change. Enabling this option may improve performance at the expense of data integrity.
5.2.5.5. directory <directory>
This directive specifies the directory where the LDBM files containing the database and associated indices live.
Default:
directory /usr/local/var/openldap-data
5.2.5.6. index {<attrlist> | default} [pres,eq,approx,sub,none]
This directive specifies the indices to maintain for the given attribute. If only an <attrlist> is given, the default indices are maintained.
Example:
index default pres,eq
index uid
index cn,sn pres,eq,sub
index objectClass eq
The first line sets the default set of indices 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 type.
By default, no indices are maintained. It is generally advised that minimally an equality index upon objectClass be maintained.
index objectClass eq
5.2.5.7. mode <integer>
This directive specifies the file protection mode that newly created database index files should have.
Default:
mode 0600
5.3. Access Control
Access to slapd entries and attributes is controlled by the access configuration file directive. The general form of an access line is:
<access directive> ::= access to <what>
[by <who> <access> <control>]+
<what> ::= * |
[dn[.<basic-style>]=<regex> | dn.<scope-style>=<DN>]
[filter=<ldapfilter>] [attrs=<attrlist>]
<basic-style> ::= regex | exact
<scope-style> ::= base | one | subtree | children
<attrlist> ::= <attr> [val[.<basic-style>]=<regex>] | <attr> , <attrlist>
<attr> ::= <attrname> | entry | children
<who> ::= * | [anonymous | users | self
| dn[.<basic-style>]=<regex> | dn.<scope-style>=<DN>]
[dnattr=<attrname>]
[group[/<objectclass>[/<attrname>][.<basic-style>]]=<regex>]
[peername[.<basic-style>]=<regex>]
[sockname[.<basic-style>]=<regex>]
[domain[.<basic-style>]=<regex>]
[sockurl[.<basic-style>]=<regex>]
[set=<setspec>]
[aci=<attrname>]
<access> ::= [self]{<level>|<priv>}
<level> ::= none | auth | compare | search | read | write
<priv> ::= {=|+|-}{w|r|s|c|x|0}+
<control> ::= [stop | continue | break]
where the <what> part selects the entries and/or attributes to which the access applies, the <who> part specifies which entities are granted access, and the <access> part specifies the access granted. Multiple <who> <access> <control> triplets are supported, allowing many entities to be granted different access to the same set of entries and attributes. Not all of these access control options are described here; for more details see the slapd.access(5) man page.
5.3.1. What to control access to
The <what> part of an access specification determines the entries and attributes to which the access control applies. Entries are commonly selected in two ways: by DN and by filter. The following qualifiers select entries by DN:
to *
to dn[.<basic-style>]=<regex>
to dn.<scope-style>=<DN>
The first form is used to select all entries. The second form may be used to select entries by matching a regular expression against the target entry's normalized DN. (The second form is not discussed further in this document.) The third form is used to select entries which are within the requested scope of DN. The <DN> is a string representation of the Distinguished Name, as described in RFC2253.
The scope can be either base, one, subtree, or children. Where base matches only the entry with provided DN, one matches the entries whose parent is the provided DN, subtree matches all entries in the subtree whose root is the provided DN, and children matches all entries under the DN (but not the entry named by the DN).
For example, if the directory contained entries named:
0: o=suffix
1: cn=Manager,o=suffix
2: ou=people,o=suffix
3: uid=kdz,ou=people,o=suffix
4: cn=addresses,uid=kdz,ou=people,o=suffix
5: uid=hyc,ou=people,o=suffix
Then:
-
dn.base="ou=people,o=suffix" match 2;
dn.one="ou=people,o=suffix" match 3, and 5;
dn.subtree="ou=people,o=suffix" match 2, 3, 4, and 5; and
dn.children="ou=people,o=suffix" match 3, 4, and 5.
Entries may also be selected using a filter:
to filter=<ldap filter>
where <ldap filter> is a string representation of an LDAP search filter, as described in RFC2254. For example:
to filter=(objectClass=person)
Note that entries may be selected by both DN and filter by including both qualifiers in the <what> clause.
to dn.one="ou=people,o=suffix" filter=(objectClass=person)
Attributes within an entry are selected by including a comma-separated list of attribute names in the <what> selector:
attrs=<attribute list>
A specific value of an attribute is selected by using a single attribute name and also using a value selector:
attrs=<attribute> val[.<style>]=<regex>
There are two special pseudo attributes entry and children. To read (and hence return) a target entry, the subject must have read access to the target's entry attribute. To add or delete an entry, the subject must have write access to the entry's entry attribute AND must have write access to the entry's parent's children attribute. To rename an entry, the subject must have write access to entry's entry attribute AND have write access to both the old parent's and new parent's children attributes. The complete examples at the end of this section should help clear things up.
Lastly, there is a special entry selector "*" that is used to select any entry. It is used when no other <what> selector has been provided. It's equivalent to "dn=.*"
5.3.2. Who to grant access to
The <who> part identifies the entity or entities being granted access. Note that access is granted to "entities" not "entries." The following table summarizes entity specifiers:
| Specifier | Entities |
| * | All, including anonymous and authenticated users |
| anonymous | Anonymous (non-authenticated) users |
| users | Authenticated users |
| self | User associated with target entry |
| dn[.<basic-style>]=<regex> | Users matching a regular expression |
| dn.<scope-style>=<DN> | Users within scope of a DN |
The DN specifier behaves much like <what> clause DN specifiers.
Other control factors are also supported. For example, a <who> can be restricted by an entry listed in a DN-valued attribute in the entry to which the access applies:
dnattr=<dn-valued attribute name>
The dnattr specification is used to give access to an entry whose DN is listed in an attribute of the entry (e.g., give access to a group entry to whoever is listed as the owner of the group entry).
Some factors may not be appropriate in all environments (or any). For example, the domain factor relies on IP to domain name lookups. As these can easily spoofed, the domain factor should not be avoided.
5.3.3. The access to grant
The kind of <access> granted can be one of the following:
| Level | Privileges | Description |
| none | =0 | no access |
| auth | =x | needed to bind |
| compare | =cx | needed to compare |
| search | =scx | needed to apply search filters |
| read | =rscx | needed to read search results |
| write | =wrscx | needed to modify/rename |
Each level implies all lower levels of access. So, for example, granting someone write access to an entry also grants them read, search, compare, and auth access. However, one may use the privileges specifier to grant specific permissions.
5.3.4. Access Control Evaluation
When evaluating whether some requester should be given access to an entry and/or attribute, slapd compares the entry and/or attribute to the <what> selectors given in the configuration file. For each entry, access controls provided in the database which holds the entry (or the first database if not held in any database) apply first, followed by the global access directives. Within this priority, access directives are examined in the order in which they appear in the config file. Slapd stops with the first <what> selector that matches the entry and/or attribute. The corresponding access directive is the one slapd will use to evaluate access.
Next, slapd compares the entity requesting access to the <who> selectors within the access directive selected above in the order in which they appear. It stops with the first <who> selector that matches the requester. This determines the access the entity requesting access has to the entry and/or attribute.
Finally, slapd compares the access granted in the selected <access> clause to the access requested by the client. If it allows greater or equal access, access is granted. Otherwise, access is denied.
The order of evaluation of access directives makes their placement in the configuration file important. If one access directive is more specific than another in terms of the entries it selects, it should appear first in the config file. Similarly, if one <who> selector is more specific than another it should come first in the access directive. The access control examples given below should help make this clear.
5.3.5. Access Control Examples
The access control facility described above is quite powerful. This section shows some examples of its use. First, some simple examples:
access to * by * read
This access directive grants read access to everyone.
access to *
by self write
by anonymous auth
by * read
This directive allows the user to modify their entry, allows anonymous to authentication against these entries, and allows all others to read these entries. Note that only the first by <who> clause which matches applies. Hence, the anonymous users are granted auth, not read. The last clause could just as well have been "by users read".
It is often desirable to restrict operations based upon the level of protection in place. The following shows how security strength factors (SSF) can be used.
access to *
by ssf=128 self write
by ssf=64 anonymous auth
by ssf=64 users read
This directive allows users to modify their own entries if security protections have of strength 128 or better have been established, allows authentication access to anonymous users, and read access when 64 or better security protections have been established. If client has not establish sufficient security protections, the implicit by * none clause would be applied.
The following example shows the use of a style specifiers to select the entries by DN in two access directives where ordering is significant.
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.
Also note that if no access to directive matches or no by <who> clause, 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 example.com 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 example.com, 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.
5.4. Configuration File Example
The following is an example configuration file, interspersed with explanatory text. It defines two databases to handle different parts of the
1. # example config file - global configuration section 2. include /usr/local/etc/schema/core.schema 3. referral ldap://root.openldap.org 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 root.openldap.org.
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. Indices are to be maintained for several attributes, and the userPassword attribute is to be protected from unauthorized access.
5. # BDB definition for the example.com 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://slave1.example.com:389 14. binddn="cn=Replicator,dc=example,dc=com" 15. bindmethod=simple credentials=secret 16. replica uri=ldaps://slave2.example.com:636 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,approx,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.
Lines 11 through 18 are for replication. Line 12 specifies the replication log file (where changes to the database are logged - this file is written by slapd and read by slurpd). Lines 13 through 15 specify the hostname and port for a replicated host, the DN to bind as when performing updates, the bind method (simple) and the credentials (password) for the binddn. Lines 16 through 18 specify a second replication site. See the Replication with slurpd chapter for more information on these directives.
Lines 20 through 22 indicate the indices to maintain for various attributes.
Lines 24 through 32 specify access control for entries in 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 example.net 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
6. Running slapd
slapd(8) 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.
6.1. Command-Line Options
slapd(8) 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://127.0.0.1:666" 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 666. 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.
-u user -g group
These options specify the user and group, respectively, to run 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
| 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_log.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.
6.2. Starting slapd
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.
6.3. Stopping slapd
To kill off slapd safely, you should give a command like this
kill -INT `cat /usr/local/var/slapd.pid`
where /usr/local/var is determined by configure.
Killing slapd by a more drastic method may cause information loss or database corruption.
7. Database Creation and Maintenance Tools
This section tells you how to create a slapd database from scratch, and how to do trouble shooting if you run into problems. 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.
7.1. Creating a database over LDAP
With this method, you use the LDAP client of your choice (e.g., the ldapadd(1)) to add entries, just like you would once the database is created. You should be sure to set the following options in the configuration file before starting slapd(8).
suffix <dn>
As described in the General Database Directives section, this option defines 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 "dc=example,dc=com"
You should be sure to specify a directory where the index files should be created:
directory <directory>
For example:
directory /usr/local/var/openldap-data
You need to create this directory with appropriate permissions such 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>
For example:
rootdn "cn=Manager,dc=example,dc=com"
rootpw secret
These options specify a DN and password that can be used to authenticate as the super-user 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.
Finally, you should make sure that the database definition contains the index definitions you want:
index {<attrlist> | default} [pres,eq,approx,sub,none]
For example, to index the cn, sn, uid and objectclass attributes, the following index directives could be used:
index cn,sn,uid pres,eq,approx,sub
index objectClass eq
This would create presence, equality, approximate, and substring indices for the cn, sn, and uid attributes and an equality index for the objectClass attribute. Note that not all index types are available with all attribute types. See The slapd Configuration File section for more information on this option.
Once you have configured things to your liking, start up slapd, connect with your LDAP client, and start adding entries. For example, to add an organization entry and an organizational role entry using the ldapadd tool, you could create an
# Organization for Example Corporation
dn: dc=example,dc=com
objectClass: dcObject
objectClass: organization
dc: example
o: Example Corporation
description: The Example Corporation
# Organizational Role for Directory Manager
dn: cn=Manager,dc=example,dc=com
objectClass: organizationalRole
cn: Manager
description: Directory Manager
and then use a command like this to actually create the entry:
ldapadd -f entries.ldif -x -D "cn=Manager,dc=example,dc=com" -w secret
The above command assumes settings provided in the above examples.
7.2. Creating a database off-line
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 to add using the LDAP method described above. These tools read the slapd configuration file and an input 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 General Database Directives section, this option defines 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 "dc=example,dc=com"
You should be sure to specify a directory where the index files should be created:
directory <directory>
For example:
directory /usr/local/var/openldap-data
Finally, you need to specify which indices 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,approx,sub
index objectClass eq
This would create presence, equality, approximate, and substring indices for the cn, sn, and uid attributes and an equality index for the objectClass attribute. Note that not all index types are available with all attribute types. See The slapd Configuration File section for more information on this option.
7.2.1. The slapadd program
Once you've configured things to your liking, you create the primary database and associated indices 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
-f <slapdconfigfile>
Specifies the slapd configuration file that tells where to create the indices, what indices to create, etc.
-d <debuglevel>
Turn on debugging, as specified by <debuglevel>. The debug levels are the same as for slapd. See the Command-Line Options section in Running slapd.
-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.
7.2.2. The slapindex program
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 contents.
7.2.3. The slapcat program
The slapcat program is used to dump the database to an
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
7.3. The LDIF text entry format
The
The basic form of an entry is:
# comment
dn: <distinguished name>
<attrdesc>: <attrvalue>
<attrdesc>: <attrvalue>
...
Lines starting with a '#' character are comments. An attribute description may be a simple attribute type like cn or objectClass or 1.2.3 (an
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=
com
cn: Barbara J
Jensen
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 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
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
A4MChAODQ4SERATGCgaGBYWGDEjJR0oOjM9PDkzODdASFxOQ
ERXRTc4UG1RV19iZ2hnPk1xeXBkeFxlZ2P/2wBDARESEhgVG
# 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 URL.
Note: 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.
8. Schema Specification
This chapter describes how to extend the user schema used by slapd(8). The chapter assumes the reader is familar with the
The first section, Distributed Schema Files details optional schema definitions provided in the distribution and where to obtain other definitions. The second section, Extending Schema, details how to define new schema items.
This chapter does not discuss how to extend system schema used by slapd(8) as this requires source code modification. System schema includes all operational attribute types or any object class which allows or requires an operational attribute (directly or indirectly).
8.1. Distributed Schema Files
OpenLDAP is distributed with a set of schema specifications for your use. Each set is defined in a file suitable for inclusion (using the include directive) in your slapd.conf(5) file. These schema files are normally installed in the /usr/local/etc/openldap/schema directory.
| File | Description |
| core.schema | OpenLDAP core (required) |
| cosine.schema | Cosine and Internet X.500 (useful) |
| inetorgperson.schema | InetOrgPerson (useful) |
| misc.schema | Assorted (experimental) |
| nis.schema | Network Information Services (FYI) |
| openldap.schema | OpenLDAP Project (experimental) |
To use any of these schema files, you only need to include the desired file in the global definitions portion of your slapd.conf(5) file. For example:
# include schema
include /usr/local/etc/openldap/schema/core.schema
include /usr/local/etc/openldap/schema/cosine.schema
include /usr/local/etc/openldap/schema/inetorgperson.schema
Additional files may be available. Please consult the OpenLDAP FAQ (http://www.openldap.org/faq/).
Note: You should not modify any of the schema items defined in provided files.
8.2. Extending Schema
Schema used by slapd(8) may be extended to support additional syntaxes, matching rules, attribute types, and object classes. This chapter details how to add user application attribute types and object classes using the syntaxes and matching rules already supported by slapd. slapd can also be extended to support additional syntaxes, matching rules and system schema, but this requires some programming and hence is not discussed here.
There are five steps to defining new schema:
- obtain Object Identifer
- choose a name prefix
- create local schema file
- define custom attribute types (if necessary)
- define custom object classes
8.2.1. Object Identifiers
Each schema element is identified by a globally unique
| OID | Assignment |
| 1.1 | Organization's OID |
| 1.1.1 | SNMP Elements |
| 1.1.2 | LDAP Elements |
| 1.1.2.1 | AttributeTypes |
| 1.1.2.1.1 | myAttribute |
| 1.1.2.2 | ObjectClasses |
| 1.1.2.2.1 | myObjectClass |
You are, of course, free to design a hierarchy suitable to your organizational needs under your organization's OID. No matter what hierarchy you choose, you should maintain a registry of assignments you make. This can be a simple flat file or something more sophisticated such as the OpenLDAP OID Registry (http://www.openldap.org/faq/index.cgi?file=197).
For more information about Object Identifers (and a listing service) see http://www.alvestrand.no/harald/objectid/.
-
Under no circumstances should you hijack OID namespace!
To obtain a registered OID at no cost, apply for an OID under the Internet Assigned Numbers Authority (IANA) maintained Private Enterprise arc. Any private enterprise (organization) may request an OID to be assigned under this arc. Just fill out the IANA form at http://www.iana.org/cgi-bin/enterprise.pl and your official OID will be sent to you usually within a few days. Your base OID will be something like 1.3.6.1.4.1.X where X is an integer.
Note: Don't let the "MIB/SNMP" statement on the IANA page confuse you. OIDs obtained using this form may be used for any purpose including identifying LDAP schema elements.
Alternatively, OID name space may be available from a national authority (e.g., ANSI, BSI).
For private experiments, OIDs under 1.1 may be used. The OID 1.1 arc is regarded as dead name space.
8.2.2. Name Prefix
In addition to assigning a unique object identifier to each schema element, you should provide a least one textual name for each element. The name should be both descriptive and not likely to clash with names of other schema elements. In particular, any name you choose should not clash with present or future Standar