.TH SLAPO-REMOTEAUTH 5 "RELEASEDATE" "OpenLDAP LDVERSION"
.\" Copyright 1998-2021 The OpenLDAP Foundation, All Rights Reserved.
.\" Copying restrictions apply.  See the COPYRIGHT file.
.\" $OpenLDAP$
.SH NAME
slapo-remoteauth \- Delegate authentication requests to remote directories, e.g. Active Directory
.SH SYNOPSIS
ETCDIR/slapd.conf
.SH DESCRIPTION
The
.B remoteauth
overlay to
.BR slapd (8)
provides passthrough authentication to remote directory servers, e.g.
Active Directory, for LDAP simple bind operations. The local LDAP entry
referenced in the bind operation is mapped to its counterpart in the remote
directory. An LDAP bind operation is performed against the remote directory
and results are returned based on those of the remote operation.
.LP
A slapd server configured with the
.B remoteauth
overlay handles an authentication request based on the presence of
.B userPassword
in the local entry. If the
.B userPassword
is present, authentication is performed locally, otherwise the
.B remoteauth
overlay performs the authentication request to the configured remote directory
server.
.LP

.SH CONFIGURATION

The following options can be applied to the
.B remoteauth
overlay within the slapd.conf file. All options should follow the
.B overlay remoteauth
directive.

.TP
.B overlay remoteauth
This directive adds the
.B remoteauth
overlay to the current database, see
.BR slapd.conf (5)
for details.

.TP
.B remoteauth_dn_attribute <dnattr>
Attribute in the local entry that is used to store the bind DN to a remote
directory server.

.TP
.B remoteauth_mapping <domain> <hostname|LDAP URI|file:///path/to/list_of_hostnames>
For a non-Windows deployment, a domain can be considered as a collection of
one or more hosts to which slapd server authentcates against on behalf of
authenticating users.
For a given domain name, the mapping specifies the target server(s),
e.g., Active Directory domain controller(s), to connect to via LDAP.
The second argument can be given either as a hostname, an LDAP URI, or a file
containing a list of hostnames/URIs, one per line. The hostnames are tried in
sequence until the connection succeeds.

This option can be provided more than once to provide mapping information for
different domains. For example:

.nf
    remoteauth_mapping americas file:///path/to/americas.domain.hosts
    remoteauth_mapping asiapacific file:///path/to/asiapacific.domain.hosts
    remoteauth_mapping emea emeadc1.emea.example.com
.fi

.TP
.B remoteauth_domain_attribute <attr>
Attribute in the local entry that specifies the domain name, any text after
"\\" or ":" is ignored.

.TP
.B remoteauth_default_domain <default domain>
Default domain.


.TP
.B remoteauth_default_realm <server>
Fallback server to connect to for domains not specified in
.BR remoteauth_mapping .

.TP
.B remoteauth_retry_count <num>
Number of connection retries attempted. Default is 3.

.TP
.B remoteauth_store <on|off>
Whether to store the password in the local entry on successful bind. Default is
off.

.HP
.hy 0
.B remoteauth_tls
.B [starttls=yes]
.B [tls_cert=<file>]
.B [tls_key=<file>]
.B [tls_cacert=<file>]
.B [tls_cacertdir=<path>]
.B [tls_reqcert=never|allow|try|demand]
.B [tls_reqsan=never|allow|try|demand]
.B [tls_cipher_suite=<ciphers>]
.B [tls_ecname=<names>]
.B [tls_crlcheck=none|peer|all]
.RS
Remoteauth specific TLS configuration, see
.BR slapd.conf (5)
for more details on each of the parameters and defaults.
.RE

.TP
.B remoteauth_tls_peerkey_hash <hostname> <hashname>:<base64 of public key hash>
Mapping between remote server hostnames and their public key hashes. Only one
mapping per hostname is supported and if any pins are specified, all hosts
need to be pinned. If set, pinning is in effect regardless of whether or not
certificate name validation is enabled by
.BR tls_reqcert .

.SH EXAMPLE
A typical example configuration of
.B remoteauth
overlay for AD is shown below (as a
.BR slapd.conf (5)
snippet):

.LP
.nf
   database <database>
   #...

   overlay remoteauth
   remoteauth_dn_attribute seeAlso
   remoteauth_domain_attribute associatedDomain
   remoteauth_default_realm americas.example.com

   remoteauth_mapping americas file:///home/ldap/etc/remoteauth.americas
   remoteauth_mapping emea emeadc1.emea.example.com

   remoteauth_tls starttls=yes tls_reqcert=demand tls_cacert=/home/ldap/etc/example-ca.pem
   remoteauth_tls_peerkey_hash ldap.americas.tld sha256:Bxv3MkLoDm6gt/iDfeGNdNNqa5TTpPDdIwvZM/cIgeo=
.fi

Where seeAlso contains the AD bind DN for the user, associatedDomain contains the
Windows Domain Id in the form of <NT-domain-name>:<NT-username> in which
anything following, including ":", is ignored.

.SH SEE ALSO
.BR slapd.conf (5),
.BR slapd (8).

.SH Copyrights
Copyright 2004-2021 The OpenLDAP Foundation.
Portions Copyright 2004-2017 Howard Chu, Symas Corporation.
Portions Copyright 2017-2021 Ondřej Kuzník, Symas Corporation.
Portions Copyright 2004 Hewlett-Packard Company