LDAP

Lightweight Directory Access Protocol

In computer networking, the Lightweight Directory Access Protocol, or LDAP ("ell-dap"), is a networking protocol for querying and modifying directory services running over TCP/IP. An LDAP directory usually follows the X.500 model: it is a tree of entries, each of which consists of a set of named attributes with values. While some services use a more complicated "forest" model, the vast majority use a simple starting point for their database organization.

An LDAP directory often reflects various political, geographic, and/or organizational boundaries, depending on the model chosen. LDAP deployments today tend to use Domain Name System (DNS) names for structuring the most simple levels of the hierarchy. Further into the directory might appear entries representing people, organizational units, printers, documents, groups of people or anything else which represents a given tree entry, or multiple entries.

Its current version is LDAPv3. LDAPv3 is specified in a series of IETF Standard Track RFCs as detailed in RFC 4510.

Interfaces

• Apache Directory Studio
• LAM (LDAP Account Manager)
• phpldapadmin
• ldapvi

Tutorials and docs

• LDAP wiki
• Pam-ldap
• http://www.zytrax.com/books/ldap/
• http://tuxick.net/ldap.html
• http://ldapadministrator.com
• OpenLDAP server on Debian using OLC
• Apache Authentication with Active Directory
• LDAP authentication on Gentoo (slightly outdated)
• LDAP Replication
• Common causes of LDAP errors
• Objectclasses
• LDAP for Rocket Scientists
• http://moduli.net/sysadmin/sarge-ldap-auth-howto.html
• OpenLDAP using OLC (cn=config)
• LDAP and SSL certificates

Access control

• Access Control
• http://www.zytrax.com/books/ldap/ch6/#access
• OLC access control

ldapmodify

• http://www.tldp.org/HOWTO/LDAP-HOWTO/utilities.html
• Delete an objectclass

 

Links

• http://www.openldap.org/
• Red Hat Directory Server documentation, worth reading
• Error messages

Client configuration

In /etc/openldap/ldap.conf

Ldapsearch

• https://theitbros.com/ldapsearch/
• ldapsearch

 

FAQ

OLC

Change OLC config

ldapmodify -Y EXTERNAL -H ldapi:///
dn: cn=config
replace: olcLogLevel
olcLogLevel: None

CTRL + D

 

view configuration in OLC

slapcat -H "ldap:///cn=config??sub?(olcDatabase=*)"

ldapsearch -Y EXTERNAL -H ldapi:/// -b cn=config

LdapErr: DSID-0C090AE1, comment: In order to perform this operation a successful bind must be completed on the connection.

login?

ldap_sasl_interactive_bind_s: Unknown authentication method (-6)

try adding "-x" to the ldapsearch,

 

add indexes

http://forum.zentyal.org/index.php?topic=3006.0 http://www.zytrax.com/books/ldap/apa/indeces.html

NOTE: there is no more need to run slapindex!!

additional info: structuralObjectClass: no user modification allowed

use slapadd instead of ldapadd, while slapd is NOT running:

slapadd -v < ldap.ldif

AttributeType inappropriate matching rule: "integerMatch"

duh

Replace LDAP database

service slapd stop
rm /var/lib/ldap/*
slapadd -l dump.ldif
chown -R openldap.openldap /var/lib/ldap
service slapd start

 

create a new database from ldif file

slapadd -f dump.ldif

Remember to set rights to the db storage!

add a record

ldapadd

modify a record

• http://docs.sun.com/source/816-6400-10/lmodify.html

 

ldapmodify -x -D "cn=admin, dc=bar, dc=com" -W << EOF
dn: cn=foo, dc=bar, dc=com
changetype: modify
replace: sn
sn: new name
EOF

Or

ldapmodify -D "cn=admin,dc=bar,dc=com" -Y EXTERNAL -H ldapi:/// << EOF
..
EOF

Or even, also for reconfiguration of OLC

ldapmodify -Y EXTERNAL -H ldapi:/// < foo.ldif

change olcAccess, olcSuffix etc

I managed this changing things in following order:

olcAccess{2}
olcAccess{0}
olcRootDN
olcSuffix

 

EOF

add an attribute

changetype: modify
add: objectClass
objectClass: qmailUser

search for a record

http://docs.sun.com/source/816-6400-10/lsearch.html

ldapsearch -x -b  -s base '(objectclass="*)'" namingContexts
ldapsearch -x -b "dc=foo, dc=com" "uid=harry"

• scope?

 

ber_get_next on fd 12 failed errno=0 (Success)

You're probably trying to use ldapadd without -x

ber_get_next on fd 15 failed errno=11 (Resource temporarily Unavailable)

??

Error number: 0x50 (LDAP_OTHER)

Internal (implementation specific) error

You probably ran slapindex as wrong user. Set rights on the directory you find under 'directory' in slapd.conf for the user slapd runs as ( openldap on debian )

search filters

• http://www.faqs.org/rfcs/rfc2254.html

 

main: TLS init def ctx failed: -1

Probably no access to one of the certificate files

 

ldif_read_file: checksum error on "/etc/ldap/slapd.d/cn=config/olcDatabase={1}bdb.ldif"

You edited config file instead of using ldapmodify. This error will go away once you used ldapmodify on it.

 

php and ldap

ignore certificates

LDAPTLS_REQCERT=never

related to TLS_REQCERT in ldap.conf, so see

man ldap.conf

check TLS connection

You might need to set up certs in /etc/openssl/ldap.conf

ldapsearch -x -ZZ -h hostname -p 389

or

openssl s_client -connect hostname:636 -cert /etc/openldap/certs/clientcert.pem -CAfile /etc/openldap/certs/cacert.pem

or

openssl s_client -starttls ldap -connect hostname:636

ldap_start_tls: Connect error (-11)

probably some cert missing

Keywords

rootdn

The user/account with full access

 

Tools

• phpldapadmin
• ldapbrowser
• lam
• shelldap
• ldapvi