LDAP
====

There are two ways to do LDAP authentication:

 * <Password lookups> [AuthDatabase.LDAP.PasswordLookups.txt]
 * <Authentication binds> [AuthDatabase.LDAP.AuthBinds.txt]

Both of these have their own advantages and disadvantages.

 * <LDAP as userdb> [AuthDatabase.LDAP.Userdb.txt] and other common LDAP query
   settings.

Configuration common to LDAP passdb and userdb
----------------------------------------------

Connecting
----------

There are two alternative ways to specify what LDAP server(s) to connect to:

 * 'hosts': A space separated list of LDAP hosts to connect to. You can also
   use host:port syntax to use different ports.
 * 'uris': A space separated list of LDAP URIs to connect to. This isn't
   supported by all LDAP libraries. The URIs are in syntax
   'protocol://host:port'. For example 'ldap://localhost' or
   'ldaps://secure.domain.org'

If multiple LDAP servers are specified, it's decided by the LDAP library how
the server connections are handled. Typically the first working server is used,
and it's never disconnected from. So there is no load balancing or automatic
reconnecting to the "primary" server.

SSL/TLS
-------

You can enable TLS in two alternative ways:

 * Connect to ldaps port (636) by using "ldaps" protocol, e.g. 'uris =
   ldaps://secure.domain.org'
 * Connect to ldap port (389) and use STARTTLS command. Use 'tls=yes' to enable
   this.

See the tls_* settings in 'dovecot-ldap-example.conf' for how to configure TLS.
(I think they apply to ldaps too?)

Getting Dovecot to talk to a LDAPS signed against a custom certificate of
authority
-----------------------------------------------------------------------------------

If you need to connect to ldaps secured against a custom certificate of
authority (CA), you will need to install the custom CA on your system.On Red
Hat Enterprise Linux 6, Dovecot uses the OpenLDAP library. By default, the CA
must be installed under the directory specified in the TLS_CACERTDIR option
found under /etc/openldap/ldap.conf (default value is /etc/openldap/certs).
After copying the CA, you'll need to run "c_rehash ." inside the directory,
this will create a symlink pointing to the CA.

You can test the CA installation with this: openssl s_client -connect
yourldap.example.org:636 -CApath /etc/openldap/certs -showcerts

This should report "Verify return code: 0 (ok)".

SASL binds
----------

It's possible to use SASL binds instead of the regular plaintext binds if your
LDAP library supports them. See the sasl_* settings in
'dovecot-ldap-example.conf'. Note that SASL binds are currently incompatible
with authentication binds.

Active Directory
----------------

When connecting to AD, you may need to use port 3268. Then again, not all LDAP
fields are available in port 3268. Use whatever
works.http://technet.microsoft.com/en-us/library/cc978012.aspx

(This file was created from the wiki on 2015-05-13 16:45)
