  LDAP Linux HOWTO
  Luiz Ernesto Pinheiro Malere, malere@yahoo.com
  v1.01, 15 February 2000

  Information about installing, configuring, running and maintaining a
  LDAP (Lightweight Directory Access Protocol) Server on a Linux machine
  is presented on this document. There are also details about how to
  create LDAP databases, how to update and delete information on the
  database, how to implement roaming access and how to use Netscape
  Address Book. This document is mostly based on the University of
  Michigan LDAP information pages.
  ______________________________________________________________________

  Table of Contents



  1. Introduction

     1.1 What's LDAP ?
     1.2 What's a Directory Service ?
     1.3 How does LDAP work ?
     1.4 LDAP backends, objects and attributes
     1.5 New Versions of this Document
     1.6 Opinions and Sugestions
     1.7 Acknowledgments
     1.8 Copyright and Disclaimer

  2. Installing the LDAP Server

     2.1 Downloading the package
     2.2 Unpacking the server
     2.3 Configuring the software
     2.4 Building the server

  3. Configuring the LDAP Server

     3.1 Configuration File Format
     3.2 Global Options
     3.3 General Backend Options
     3.4 LDBM Backend-Specific Options
     3.5 Access Control Examples

  4. Running the LDAP Server

     4.1 Command Line Options
     4.2 Running slapd as a Stand Alone Daemon
     4.3 Running slapd from inetd

  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. Aditional Informations and Features

     6.1 Roaming Access
     6.2 Netscape Address Book
     6.3 LDAP Migration Tools
     6.4 Authentication using LDAP
     6.5 Graphical LDAP tools
     6.6 Killing the LDAP server
     6.7 Logs

  7. References

     7.1 URLs
     7.2 Books
     7.3 RFCs


  ______________________________________________________________________

  1.  Introduction

  The main purpose of this document is to setup 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 run a slapd which provides directory
  service for your local domain only, without replication, so without
  slurpd.

  This is a simple configuration for the server, good for starting but
  easy to upgrade to another configuration later if you want.  The
  information presented on this document represents a nice
  initialization on using the LDAP protocol. Possibly after reading this
  document you would feel encouraged to expand the capabilities of your
  server and even write your own clients, using the already avaiable C,
  C++ and Java Development Kits.


  1.1.  What's LDAP ?

  LDAP is a client-server protocol for accessing a directory service.
  It was initially used as a front-end to X.500, but can also be used
  with stand-alone and other kinds of directory servers.


  1.2.  What's a Directory Service ?

  A directory is like 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. As a consequence,
  directories don't usually implement the complicated transaction or
  roll-back schemes that regular databases use for doing 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 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.


  1.3.  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 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 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.  LDAP backends, objects and attributes

  Slapd comes with three different backend databases you can choose
  from. They are LDBM, a high-performance disk-based database; SHELL, a
  database interface to arbitrary UNIX commands or shell scripts; and
  PASSWD, a simple password file database.

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

  The LDBM database works by assigning a compact four-byte unique
  identifier to each entry in the database. It uses this identifier to
  refer to entries in indexes. The database consists of one main index
  file, called id2entry, which maps from an entry's unique identifier
  (EID) to a text representation of the entry itself. Other index files
  are maintained as well.

  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. An 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
  LDBM 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
       mail: malere@yahoo.com
       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.

  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:

  o  Groups in the directory, including unordered lists of individual
     objects or groups of objects.

  o  Locations, such as the country name and description.

  o  Organizations in the directory.

  o  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 (its
  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
       mail: jonass@airius.com



  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
  :

  o  bin binary

  o  ces case exact string (case must match during comparisons)

  o  cis case ignore string (case is ignored during comparisons)

  o  tel telephone number string (like cis but blanks and dashes `- '
     are ignored during comparisons)

  o  dn distinguished name


  Go to the first paragraph of ``section 3'' to know where the
  objectclass and attribute definitions lay on your system.


  1.5.  New Versions of this Document

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

  http://dutedin.et.tudelft.nl/~malere/LDAP-Linux-HOWTO.html
  <http://dutedin.et.tudelft.nl/~malere/LDAP-Linux-HOWTO.html>

  for new versions of this HOWTO.


  1.6.  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 :

  malere@yahoo.com <mailto:malere@yahoo.com>


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


  1.7.  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.


  1.8.  Copyright and Disclaimer

  The LDAP Linux HOWTO is Copyrighted 1999 by Luiz Ernesto Pinheiro
  Malere. It can be distributed freely. It cannot be modified. If you
  have any kind of sugestion, please send me an email (I will update the
  document if the sugestion proceeds).

  If you want a translation, for example to Portuguese, you can send me
  an email about it too.

  No liability for the contents of this document can be accepted. I have
  no responsability about the consequences of following the steps
  provided in this document.

  If you have questions, please contact, the Linux HOWTO coordinator, at

  linux-howto@metalab.unc.edu <linux-howto@metalab.unc.edu>


  2.  Installing the LDAP Server

  Four steps are necessary to install the server : Download the package,
  Unpack the software, Configure the Makefiles and Build the server.


  2.1.  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 aditional documentation avaiable for it. This
  document supposes that you are using the OpenLDAP server.

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

  http://www.openldap.org <http://www.openldap.org>

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

  ftp://terminator.rs.itd.umich.edu/ldap
  <ftp://terminator.rs.itd.umich.edu/ldap>

  To write this document, I used the OpenLDAP latest stable version and
  OpenLDAP 1.2.8 on a Slackware Linux machine with kernel 2.2.6. On the
  OpenLDAP site you can 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-990918.tgz, also available
  through the link openldap-stable.tgz. The latest development version
  was openldap-1_2_8.tgz.



  2.2.  Unpacking the server

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

  First copy the package to a desirable directory, for example
  /usr/local.

  Then use the following command :



       tar xvzf openldap-stable.tgz



  You can use this command too, as well :



       gunzip openldap-stable.tgz | tar xvf -



  2.3.  Configuring the software

  There are several options that you should like to customize so you can
  build the best software to your site.

  To configure the software you just need 2 steps :

  o  Edit the file ldapconfig.h.edit, located on the subdirectory
     include beneath the directory where you unpacked the software.

  o  Run the configure script (if you are a tough guy, you can also edit
     the Make-common file instead of running the configure script :^)

  In the file include/ldapconfig.h.edit you can set options like the
  location of the slapd and slurpd daemons. The file itself is well
  commented and it's default settings also reflect the most common
  administrator choices so, if you are in a hurry you can skip this
  step, and run directly:



       vi include/ldapconfig.h.edit



  The OpenLDAP server sources are distributed with a configuration
  script for setting options like instalation 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 prepar to
  build things on the default common location. So just type :


       ./configure



  And watch the output to see if all went well


  2.4.  Building the server

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


       make depend



  After build the server, using the command :


       make



  If all goes well, the server will build as configured.  If not, return
  to the previous step to review the configuration settings. You should
  check the platform specific hints, they are located in the path
  doc/install/hints under the directory you unpacked the software.

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


       su
       make install



  That's all, now you have the binary of the server and the binaries of
  several other utilities. Go to the ``next'' section to see how to con-
  figure the operation of your LDAP server.


  If before learning how to configure your LDAP server you would like to
  test the recently built binaries, the latest versions of the OpenLDAP
  server come with a test script. When this document was updated the
  test script was not 100% stable for all diagnostics that it performed.
  Anyway you can try to run it and, if anything goes wrong with the
  script you can just abort it hitting Ctrl-C. In my case before the
  script stopped working I could see some successfull messages about the
  results of the most common diagnostics. To run the test script, go to
  the subdirectory /test beneath the path where you unpacked the
  software and type :



  make



  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.

  In this directory you will also find the files slapd.oc.conf and
  slapd.at.conf which are included on the slad.conf file (see include
  option on ``section 3.2'') and that hold respectively the
  objectclasses and attributes definitions for the LDAP database
  backend.  Next comes a description of the general format of the config
  file, followed by a detailed description of each config file option.


  3.1.  Configuration File Format

  The slapd.conf file consists of a series of global configuration
  options that apply to slapd as a whole (including all database
  backends), followed by zero or more database backend definitions that
  contain information specific to a backend instance.

  Global options can be overridden in a backend (for options that appear
  more than once, the last appearance in the slapd.conf file is used).
  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. The general format of slapd.conf is
  as follows:


            # comment - these options apply to every database
            <global config options>
            # first database definition & config options
            database <backend 1 type>
            <config options specific to backend 1>
            # second database definition & config options
            database <backend 2 type>
            <config options specific to backend 2>
            # subsequent database definitions & config options
            ...



  Configuration line arguments 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 `\', (e.g. `\\d')..

  The distribution contains an example configuration file that will be
  installed in the configuration prefix directory. Also provided are
  slapd.at.conf, which contains many commonly used attribute
  definitions, and slapd.oc.conf, which contains many commonly used
  object class definitions.



  3.2.  Global Options

  Options described in this section apply to all backends, unless
  specifically overridden in a backend definition. Option arguments that
  should be replaced by actual text are shown in brackets <>.

  access to <what> [ by <who> <accesslevel> ]+


       This option 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 Examples for more details.



  attribute <name> [<name2>] { bin | ces | cis | tel | dn }


       This option associates a syntax with an attribute name. By default, an attribute is assumed to have
       syntax cis. An optional alternate name can be given for an attribute. The possible syntaxes and their
       meanings are :

       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



  defaultaccess { none | compare | search | read | write }


       This option specifies the default access to grant requesters not matched by any other access line (take a look on
       Access Control examples down). Note that an access level implies all lesser access levels (e.g., write access
       implies read, search and compare).
       Default:
       defaultaccess read



  include <filename>


       This option 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. You can use this option to include the files that contain the objectclass and attribute definitions of
       your backend database. The LDAP software package comes with the files slapd.oc.conf and slapd.at.conf

       Note: You should be careful when using this option - there is no small limit on the number of nested include
       options, and no loop detection is done.



  loglevel <integer>



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

  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 255
  This will cause lots and lots of debugging information to be syslogged.
  Default:
  loglevel 256



  objectclass <name> [ requires <attrs> ] [ allows <attrs> ]


       This option defines the schema rules for the given object class. Used in conjunction with the schemacheck
        option.



  referral <url>


       This option specifies the referral to pass back when slapd cannot find a local database to handle a request.
       Example:
       referral ldap://ldap.itd.umich.edu
       This will refer non-local queries to the LDAP server at the University of Michigan. 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.



  schemacheck { on | off }


       This option turns schema checking on or off. If schema checking is on, entries added or modified will be
       checked to ensure they obey the schema rules implied by their object class(es) as defined by the corresponding
       objectclass option(s). If schema checking is off this check is not done.
       Default:
       schemacheck off



  sizelimit <integer>



  This option specifies the maximum number of entries to return from a search operation.
  Default:
  sizelimit 500



  srvtab <filename>


       This option specifies the srvtab file in which slapd can find the kerberos keys necessary for authenticating
       clients using kerberos. This option is only meaningful if you are using kerberos authentication, which must
       be enabled at compile time by including the appropriate definitions in the Make-common file.
       Default:
       srvtab /etc/srvtab



  timelimit <integer>


       This option 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



  3.3.  General Backend Options

  Options in this section only apply to the backend in which they are
  defined. They are supported by every type of backend.

  database <databasetype>


       This option marks the beginning of a new database instance definition. <databasetype> should be one of
       ldbm, shell, or passwd, depending on which backend will serve the database.
       Example:
       database ldbm
       This marks the beginning of a new LDBM backend database instance definition.



  lastmod { on | off }


       This option controls whether slapd will automatically maintain the modifiersName, modifyTimestamp, creatorsName,
       and createTimestamp attributes for entries.
       Default:
       lastmod off



  readonly { on | off }



  This option puts the database into "read-only" mode. Any attempts to modify the database will return an
  "unwilling to perform" error.
  Default:
  readonly off



  replica host=<hostname>[:<port>] "binddn=<DN>" bindmethod={ simple |
  kerberos } [credentials=<password>] [srvtab=<filename>]


       This option specifies a replication site for this database. The host= parameter specifies 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) is used.
       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, typically given as a "rootdn" in the slave's config file.
       It must also match the updatedn option in the slave slapd's config file. Since DNs are likely to contain
       embedded spaces, the entire "binddn=<DN>" string should be enclosed in quotes.
       bindmethod is either simple or kerberos, depending on whether simple password-based authentication or kerberos
       authentication is to be used when connecting to the slave slapd. Simple authentication requires a valid password
       be given. Kerberos authentication requires a valid srvtab file.
       The credentials= parameter, which is only required if using simple authentication, gives the password for
       binddn on the slave slapd.
       The srvtab= parameter, which is only required if using kerberos, specifies the filename which holds the kerberos
       key for the slave slapd. If omitted, /etc/srvtab is used.



  replogfile <filename>


       This option 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 option 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.



  rootdn <dn>


       This option specifies the DN of an entry that is not subject to access control or administrative limit restrictions
       for operations on this database.
       Example:
       rootdn "cn=Manager, o=U of M, c=US"



  rootkrbname <kerberosname>


       This option specifies a kerberos name for the DN given above that will always work, regardless of whether an
       entry with the given DN exists or has a krbName attribute. This option is usefull when creating a database and
       also when using slurpd to provide replication service.
       Example:
       rootkrbname admin@umich.edu



  rootpw <password>


       This option specifies a password for the DN given above that will always work, regardless of whether an entry
       with the given DN exists or has a password. This option is usefull when creating a database and also when using
       slurpd to provide replication service. Avoid having cleartext password on this option. At least provide an
       crypto (you can use an entry of Unix /etc/passwd file) password. Slapd supports other types of encryption
       methods too.
       Example:
       rootpw secret
       rootpw {crypto}encrypted_password_here



  suffix <dn suffix>


       This option 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 "o=University of Michigan, c=US"
       Queries with a DN ending in "o=University of Michigan, c=US" 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.



  updatedn <dn>


       This option is only applicable in a slave slapd. It specifies the DN allowed to make changes to the replica
       (typically, this is the DN slurpd binds as when making changes to the replica).



  3.4.  LDBM Backend-Specific Options

  Options 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" line.

  cachesize <integer>


       This option specifies the size in entries of the in-memory cache maintained by the LDBM backend database
       instance.
       Default:
       cachesize 1000



  dbcachesize <integer>


       This option 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 option is ignored without comment. Increasing this number
       uses more memory but can cause a dramatic performance increase, especially during modifies or when building
       indexes.
       Default:
       dbcachesize 100000

  directory <directory>


       This option specifies the directory where the LDBM files containing the database and associated indexes live.
       Default:
       directory /usr/tmp



  index {<attrlist> | default} [pres,eq,approx,sub,none]


       This option specifies the indexes to maintain for the given attribute. If only an <attrlist> is given,
       all possible indexes are maintained.
       Example:
       index cn
       index sn,uid eq,sub,approx
       index default none

       This example causes all indexes to be maintained for the cn attribute; equality, substring, and approximate
       indexes for the sn and uid attributes; and no indexes for all other attributes.



  mode <integer>


       This option specifies the file protection mode that newly created database index files should have.
       Default:
       mode 0600



  3.5.  Access Control Examples

  The access control facility presented on ``section 3.2'' 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. If it appears
  alone it is the same as the following defaultaccess line.


       defaultaccess read



  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=University of Michigan, c=US" subtree, to
  which search access is granted. 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.

  The next example again shows the importance of ordering, both of the
  access directives and the "by" clauses. It also shows the use of an
  attribute selector to grant access to a specific attribute and various
  <who> selectors.


       access to dn=".*, o=U of M, c=US" attr=homePhone
       by self write
       by dn=".*, o=U of M, c=US" search
       by domain=.*\.umich\.edu read
       by * compare
       access to dn=".*, o=U of M, c=US"
       by self write
       by dn=".*, o=U of M, c=US" search
       by * none



  This example applies to entries in the "o=U of M, c=US" subtree. To
  all attributes except homePhone, the entry itself can write them,
  other U-M entries can search by them, anybody else has no access. The
  homePhone attribute is writable by the entry, searchable by other U-M
  entries, readable by clients connecting from somewhere in the
  umich.edu domain, and comparable by everybody else.

  Sometimes it is usefull 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 too 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.

  Note that the attr=member construct in the <what> clause is a
  shorthand for the clause "dn=* attr=member" (i.e., it matches the
  member attribute in all entries).



  4.  Running the LDAP Server

  Slapd can be run in two different modes, stand-alone or from inetd(8).
  Stand-alone operation is recommended, especially if you are using the
  LDBM backend. This allows the backend to take advantage of caching and
  avoids concurrency problems with the LDBM index files. If you are
  running only a PASSWD or SHELL backend, running from inetd is an
  option.


  4.1.  Command Line Options

  Slapd supports the following command-line options.

  -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

       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
       65535 enable all debugging

       Debugging levels are additive. That is, if you want to trace function calls and watch the config file being
       processed, you would set level to the sum of those two levels (in this case, 65). Consult the <ldap.h> file
       for more details.
       Note that slapd must have been compiled with -DLDAP_DEBUG defined for any debugging information beyond the
       two stats levels to be available.



  -f <filename>


       This option specifies an alternate configuration file for slapd.



  -i


       This option tells slapd that it is running from inetd instead of as a stand-alone server. On the following section
       about running slapd from inetd you will find more details.



  -p <port>


       This option specifies an alternate TCP port on which slapd should listen for connections. The default port
       is 389.

  4.2.  Running slapd as a Stand Alone Daemon

  In general, slapd is run like this:

  $(ETCDIR)/slapd [<option>]*

  where ETCDIR has the value you gave in the Make-common file or
  configure script during the pre-build configuration, and <option> is
  one of the options described above.  Unless you have specified a
  debugging level, slapd will automatically fork and detach itself from
  its controlling terminal and run in the background. Any of the options
  given above can be given to slapd to point it at a different
  configuration file, listen on another port, etc.

  See this example of starting slapd :

  $(ETCDIR)/slapd -f /home/malere/myslapd.conf -d 255


  4.3.  Running slapd from inetd

  First, make sure that running from inetd(8) is a good idea. If you are
  using the LDBM backend, it is not. If you are in a high-volume
  environment, the overhead of running from inetd also makes it a bad
  idea. Otherwise, you may proceed with the two steps necessary.

  Step 1 is to add a line like this to your /etc/services file:


       ldap 389 # ldap directory service



  Step 2 is to add a line like this to your /etc/inetd.conf file:


       ldap stream tcp nowait nobody $(ETCDIR)/slapd slapd -i



  where ETCDIR has the value you gave it in the Make-common file or
  configure script during pre-build configuration. Finally, send inetd a
  HUP signal, and you should be all set.


  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).

  The second method of database creation is to do it off-line, using the
  index generation tools. 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.



  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. 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'', 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 created:

  directory <directory>

  For example:

  directory /usr/local/tudelft

  You need to make it so you can connect to slapd as somebody with
  permission to add entries. This is done through the following two
  options in the database definition:

  rootdn <dn>

  rootpw <passwd>   /* Remember to use crypto 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.

  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 configuration lines could be used.

  index cn,sn,uid

  index objectclass pres,eq

  index default none

  Once you have configured things to your liking, start up slapd,
  connect with your LDAP client, and start adding entries. For example,
  to add a 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
  objectClass=organization
  description=Technical University of Delft Netherlands

  cn=Postmaster, o=TUDelft, c=NL
  objectClass=organizationalRole
  cn=Postmaster
  description= TUDelft postmaster - postmaster@tudelft.nl



  and then use a command like this to actually create the entry:


       ldapadd -f /tmp/newentry -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".  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 -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
  index generation 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.  They produce
  the LDBM index files directly. 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 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 created:

  directory <directory>

  For example:

  directory /usr/local/tudelft

  Next, you probably want to increase the size of the in-core cache used
  by each open index file. For best performance during index creation,
  the entire index should fit in memory.  If your data is too big for
  this, or your memory too small, you can still make it pretty big and
  let the paging system do the work. This size is set with the following
  option:

  dbcachesize <integer>

  For example:

  dbcachesize 50000000

  This would create a cache 50 MB big, which is pretty big (at
  University of Michigan, the database has about 125K entries, and the
  biggest index file is about 45 MB). Experiment with this number a bit,
  and the degree of parallelism (explained below), to see what works
  best for your system. Remember to turn this number back down once your
  index files are created and before you run slapd.

  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,approx

  index default none

  This would create presence, equality and approximate indexes for the
  cn, sn, and uid attributes, and no indexes for any other attributes.
  See the configuration file on ``section 3'' for more information on
  this option.

  Once you've configured things to your liking, you create the indexes
  by running the ldif2ldbm program:

  ldif2ldbm -i <inputfile> -f <slapdconfigfile> [-d <debuglevel>] [-j
  <integer>] [-n <databasenumber>] [-e <etcdir>]

  The arguments have the following meanings:

  -i <inputfile>

  Specifies the LDIF input file containing the entries to add in text
  form.

  -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 ``section 4.1'').

  -j <integer>

  An optional argument that specifies that at most <integer> processes
  should be started in parallel when building the indexes. The default
  is 1. If set to a value greater than one, ldif2ldbm will create at
  most that many subprocesses at a time when building the indexes. A
  separate subprocess is created to build each attribute index. Running
  these processes in parallel can speed things up greatly, but beware of
  creating too many processes, all competing for memory and disk
  resources.
  -n <databasenumber>

  An optional argument that specifies the configuration file database
  for which to build indices. The first database listed is "1", the
  second "2", etc. By default, the first ldbm database in the
  configuration file is used.

  -e <etcdir>

  An optional argument that specifies the directory where ldif2ldbm can
  find the other database conversion tools it needs to execute
  (ldif2index and friends). The default is the installation directory
  set on the configure script. Look an example of using the ldif2ldbm
  command :

  /usr/local/sbin/ldif2ldbm -i new_entries -f myslapd.conf


  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:


       [<id>]
       dn: <distinguished name>
       <attrtype>: <attrvalue>
       <attrtype>: <attrvalue>
       ...



  where <id> is the optional entry ID (a positive decimal number).
  Normally, you would not supply the <id>, allowing the database
  creation tools to do that for you. The ldbmcat program, however,
  produces an LDIF format that includes <id> so that new indexes created
  will be consistent.

  A line may be continued by starting the next line with a single space
  or tab character. e.g.,


       dn: cn=Barbara J Jensen, o=University of Michigan, c=US



  Multiple attribute values are specified on separate lines. e.g.,


       cn: Barbara J Jensen
       cn: Babs Jensen



  If an <attrvalue> contains a non-printing character, or begins with a
  space or a colon `:', the <attrtype> is followed by a double colon and
  the value is encoded in base 64 notation. e.g., the value " begins
  with a space" would be encoded like this:


       cn:: IGJlZ2lucyB3aXRoIGEgc3BhY2U=


  Multiple entries within the same LDIF file are separated by blank
  lines. Here's an example of an LDIF file containing three entries.


       dn: cn=Barbara J Jensen, o=University of Michigan, c=US
       cn: Barbara J Jensen
       cn: Babs Jensen
       objectclass: person
       sn: Jensen

       dn: cn=Bjorn J Jensen, o=University of Michigan, c=US
       cn: Bjorn J Jensen
       cn: Bjorn Jensen
       objectclass: person
       sn: Jensen

       dn: cn=Jennifer J Jensen, o=University of Michigan, c=US
       cn: Jennifer J Jensen
       cn: Jennifer Jensen
       objectclass: person
       sn: Jensen
       jpegPhoto:: /9j/4AAQSkZJRgABAAAAAQABAAD/2wBDABALD
       A4MChAODQ4SERATGCgaGBYWGDEjJR0oOjM9PDkzODdASFxOQ
       ERXRTc4UG1RV19iZ2hnPk1xeXBkeFxlZ2P/2wBDARESEhgVG
       ...



  Notice that the jpegPhoto in Jennifer Jensen's entry is encoded using
  base 64. The ldif program that comes with the OpenLDAP package can be
  used to produce the LDIF format.

  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.


  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
  our LDAP databse backend.

  The synopsis to call ldapsearch is the following (take a look at the
  ldapsearch man page to see what each option mean) :


       ldapsearch  [-n]  [-u]  [-v]  [-k]  [-K]  [-t]  [-A] [-B] [-L] [-R] [-d debuglevel] [-F sep] [-f file]
       [-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.

  Here are some examples of use of ldapsearch :



  ldapsearch -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) and the -u
  option stands for userfriendly output information.

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

  The synopsis to call ldapdelete is the following (take a look at the
  ldapdelete man page to see what each option mean) :


       ldapdelete   [-n]   [-v]  [-k]  [-K]  [-c]  [-d debuglevel]  [-f file]  [-D binddn]  [-W]  [-w passwd]
       [-h ldaphost] [-p ldapport] [dn]...



  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 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 databse 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 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
       mail: modme@terminator.rs.itd.umich.edu
       -
       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 "modme@terminator.rs.itd.umich.edu", 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
       mail=modme@terminator.rs.itd.umich.edu
       +title=Grand Poobah
       +jpegPhoto=/tmp/modme.jpeg
       -description



  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
  mail: bjensen@terminator.rs.itd.umich.edu
  uid: bjensen



  The command:


       ldapadd -f /tmp/entrymods



  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).


  6.  Aditional Informations and Features

  On this section you will find information about the Netscape Address
  Book, a LDAP client that can be used to query your Directory. Also is
  presented details on how to implement Roaming Access using the
  Netscape Navigator, version 4.5 or above and your LDAP server. There
  have been a lot of talk on the OpenLDAP mailing lists about the
  Roaming Access, since this is a feature that is not totally
  implemented. Most part of the people don't like the way Netscape
  Navigator operates with the LDAP server while making downloads and
  uploads to it. So, if after reading this you find that the Roaming
  Access is not working the way you would like, nevermind, a lot of
  people passed through this situation already. The purpose of
  introducing this feature here is more for giving people an idea about
  the capabilities of the LDAP protocol. To finish you will see some
  information about killing safely the slapd process and about slapd
  logs.



  6.1.  Roaming Access

  The goal of Roaming Access is that wherever you are on the Net, you
  can retrieve your bookmarks, preferences, mail filters, etc. using a
  Netscape Navigator and a LDAP server.  This is a very nice feature,
  imagine that wherever you access the Web, you can have your own
  settings on the browser. If you will travell and you need to access
  that currency site that is stored on your local bookmarks, don't
  worry, upload the bookmarks and other configuration files to a LDAP
  server and you can retrieve them all later independent of the place
  you will be.

  To implement the Roaming Access you have to follow these steps :

  o  Change your attributes description file

  o  Change your objectclass description file

  o  Change the LDIF file to include profiles

  o  Configure Netscape Navigator to use the LDAP server as a Roaming
     Access Server

  o  Restart the LDAP server with the new settings.

  - Changing the attributes file : You need to add new attributes on the
  attribute list present on the file slapd.at.conf (this is a file you
  include on your slapd.conf and it's normally located at
  /usr/local/etc/openldap) :


       attribute       nsLIPtrURL              ces
       attribute       nsLIPrefs               ces
       attribute       nsLIProfileName         cis
       attribute       nsLIData                bin
       attribute       nsLIElementType         cis
       attribute       nsLIServerType          cis
       attribute       nsLIVersion             cis



  - Changing the objectclass file : You also have to add some new
  classes to your slapd.oc.conf (this is another file you include on
  your slapd.conf and it's normally located at /usr/local/etc/openldap)
  in order to enable the roaming access :



  objectclass nsLIPtr
  requires
          objectclass
  allows
          nsliptrurl,
          owner

  objectclass nsLIProfile
  requires
          objectclass,
          nsliprofilename
  allows
          nsliprefs,
          uid,
          owner

  objectclass nsLIProfileElement
  requires
          objectclass,
          nslielementtype
  allows
          owner,
          nslidata,
          nsliversion

  objectclass nsLIServer
  requires
          objectclass,
          serverhostname
  allows
          description,
          cn,
          nsserverport,
          nsliservertype,
          serverroot



  - Changing the LDIF file : Now you have to modify your LDIF file,
  adding profiles entries to each user that wish to try the Roaming
  Access feature of Netscape. Look an example of a simple LDIF file with
  profiles entries :


       dn: o=myOrg,c=NL
       o: myOrg
       objectclass: organization

       dn: cn=seallers,ou=People,o=myOrg,c=NL
       cn: seallers
       userpassword: myPassword
       objectclass: top
       objectclass: person

       dn: nsLIProfileName=seallers,ou=Roaming,o=myOrg,c=NL
       changetype: add
       objectclass: top
       owner: cn=seallers,ou=People,o=myOrg,c=NL
       objectclass: top
       objectclass: nsLIProfile



  The next step is to configure Netscape to enable the Roaming Access
  against your LDAP server. Just follow the sequence :

  - Go to Menu Edit -> Preferences -> Roaming User

  Now you have to first Enable the Roaming Access for this profile,
  clicking on the checkbox correspondent to this option.

  - Fill the username box with an appropiate value, for instance john

  Pull down the arrow of the Roaming User option on the left side of the
  Preferences Window, so see the suboptions of Roaming Access.

  - Click on Server Information and enable the option LDAP Server and
  fill the boxes with the following information :

  Address: ldap://myHost/nsLIProfileName=$USERID,ou=Roaming,o=myOrg,c=NL

  User DN: cn=$USERID,ou=People,o=myOrg,c=NL

  IMPORTANT : Netscape automatically substitutes the $USERID variable
  for the name of the profile you selected before running the browser.
  So if you selected the profile seallers, it will substitute $USERID
  for seallers, if you selected profile gonzales, if will substitute
  $USERID for gonzales. If you are not familiar with profiles, run the
  Profile Manager aplication that comes on the Netscape Comunicator
  package. It's an application designed to satisfy the multiple users of
  a browser on the same machine, so each one can have their on settings
  on the browser.

  The final step is to restart the server, take a look on the ``section
  6.6'' to see how you do that safely and on ``section 4'' to see how to
  start it again.


  6.2.  Netscape Address Book

  Once you have your LDAP server up and running, you can access it with
  many diferent clients (e.g. ldapsearch command line utility). A very
  interesting one is the Netscape Address Book. It's avaiable from
  version 4.x of Netscape but you have to use the 4.5 or above version
  for a stable interoperation with your LDAP server.

  Just follow the sequence :

  Open Netscape Navigator -> Go to Communicator Menu -> Address Book

  The Netscape Address Book will be launched with some default LDAP
  directories. You have to add your own LDAP directory too !

  Go to File Menu -> New Directory

  Fill the boxes with your server information. For example :

  - Description : TUDelft

  - LDAP Server : dutedin.et.tudelft.nl

  - Server Root : o=TUDelft, c=NL

  The default LDAP port is 389, don't change it, at least if you changed
  this option while building your server.

  Now, make simple queries to your server, using the box Show Names
  Containing, or advanced queries, using the Search for button.


  6.3.  LDAP Migration Tools

  The LDAP Migration Tools are a collection of Perl scripts used to
  convert configuration files to the LDIF format. The scripts are
  provided by PADL Software Ltd and I recommend you to take a look on
  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
  usefull. Use the Migration Tools to convert your NIS or password
  archives to the LDIF format, making these files compatible with your
  LDAP Server. Apply also 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:



       http://www.padl.com/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
  aplying the scripts.


  6.4.  Authentication using LDAP

  Your LDAP server can authenticate users using a mechanism called PAM
  (Pluggable Authentication Modules). Since the beginnings of UNIX,
  authenticating a user has been accomplished via the user entering a
  password and the system checking if the entered password corresponds
  to the encrypted official password that is stored in /etc/passwd.


  That was in the beginning. Since then, a number of new ways for
  authenticating users became popular, including more complicated
  replacements for the /etc/passwd file and hardware devices called
  Smart cards. The problem is that each time a new authentication schema
  is developed, it requires all the necessary programs (login, ftpd
  etc...) to be rewritten to support it. PAM provides a way to develop
  programs that are independent of authentication scheme. These programs
  need "authentication modules" to be attatched to them at run-time in
  order to work.


  The authentication module for LDAP is available as a tar ball on the
  following address :



       http://www.padl.com/pam_ldap.html



  Here I assume that your Linux distribution is already PAM prepared. If
  not take a look on this url : http://www.kernel.org/pub/linux/libs/pam
  <http://www.kernel.org/pub/linux/libs/pam>. Actually, the various
  Linux distributions use different standard settings related to PAM.
  Usually, the configuration PAM files reside on the /etc/pam.d/
  directory. There you can find a file for each service running on your
  box. As an example, if you want to use the LDAP server for logging
  users in after your Linux boot up, you should make your Linux PAM
  compatible (as described on the begin of this paragraph), install the
  LDAP PAM module and edit a file called login on the PAM configuration
  directory (/etc/pam.d/) with the following content :
       #%PAM-1.0
       auth       required     /lib/security/pam_securetty.so
       auth       required     /lib/security/pam_nologin.so
       auth       sufficient   /lib/security/pam_ldap.so
       auth       required     /lib/security/pam_unix_auth.so try_first_pass
       account    sufficient   /lib/security/pam_ldap.so
       account    required     /lib/security/pam_unix_acct.so
       password   required     /lib/security/pam_cracklib.so
       password   required     /lib/security/pam_ldap.so
       password   required     /lib/security/pam_pwdb.so use_first_pass
       session    required     /lib/security/pam_unix_session.so



  6.5.  Graphical LDAP tools


  o  Kldap



       Kldap is a graphical LDAP client wrote for the KDE desktop environ-
       ment. Kldap has a nice interface and is able to show all the informa-
       tion tree stored on your Directory. You can check some screenshots
       from the application and download it at:



       http://www.mountpoint.ch/oliver/kldap



  o  GQ



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



       http://biot.com/gq/



  6.6.  Killing the LDAP server

  To kill off slapd safely, you should give a command like this

  kill -TERM `cat $(ETCDIR)/slapd.pid`

  Killing slapd by a more drastic method may cause its LDBM 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 slapd.pid in the
  directory you configured in slapd.conf file, for example :
  /usr/local/var/slapd.pid

  You can change the location of this pid file by changing the
  SLAPD_PIDFILE variable in include/ldapconfig.h.edit
  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/slapd.args

  You can change the location of the args file by changing the
  SLAPD_ARGSFILE variable in include/ldapconfig.h.edit.


  6.7.  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 at /etc directory.

  Create a line like this :

  local4.*     /usr/adm/ldalog

  This will use the default user LOCAL4 for the syslog facility. If you
  are not familiar with the sintax of this line, take a look at the man
  pages of syslog, syslog.conf and syslogd. If you want to change the
  default user or to specify the level of the logs generated, 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) facility.

  Now take a look at the logs generated, they can help you a lot to
  solve problems with queries, updates, binding, etc.


  7.  References

  On this section you will find aditional documentation about LDAP :
  usefull Urls, cool Books and definition RFCs.


  7.1.  URLs

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

  o  University of Michigan LDAP Page :

     http://www.umich.edu/~dirsvcs/ldap/index.html
     <http://www.umich.edu/~dirsvcs/ldap/index.html>

  o  University of Michigan LDAP Documentation Page :

     http://www.umich.edu/~dirsvcs/ldap/doc/
     <http://www.umich.edu/~dirsvcs/ldap/doc/>

  o  Manually Implementing Roaming Access

     http://help.netscape.com/products/client/communicator/manual_roaming2.html
     <http://help.netscape.com/products/client/communicator/manual_roaming2.html>

  o  Customizing LDAP Settings for Communicator 4.5 :

     http://developer.netscape.com/docs/manuals/communicator/ldap45.htm
     <http://developer.netscape.com/docs/manuals/communicator/ldap45.htm>

  o  Linux Directory Service

     http://www.rage.net/ldap/ <http://www.rage.net/ldap/>


  7.2.  Books

  These are the most popular and usefull books about LDAP :


  o  Implementing LDAP by Mark Wilcox

  o  LDAP: Programming Directory-Enabled Applications with Lightweight
     Directory Access Protocol by Howes and Smith

  o  Understanding and Deploying LDAP Directory Servers by Howes, Smith,
     and Good


  7.3.  RFCs

  The RFCs that support the LDAP development efforts :

  o  RFC 1558: A String Representation of LDAP Search Filters

  o  RFC 1777: Lightweight Directory Access Protocol

  o  RFC 1778: The String Representation of Standard Attribute Syntaxes

  o  RFC 1779: A String Representation of Distinguished Names

  o  RFC 1781: Using the OSI Directory to Achieve User Friendly Naming

  o  RFC 1798: Connectionless LDAP

  o  RFC 1823: The LDAP Application Programming Interface

  o  RFC 1959: An LDAP URL Format

  o  RFC 1960: A String Representation of LDAP Search Filters

  o  RFC 2251: Lightweight Directory Access Protocol (v3)

  o  RFC 2307: LDAP as a Network Information Service



