usr.bin/ldap/ldap.1

.\" $OpenBSD: ldap.1,v 1.11 2021/02/10 06:52:05 jmc Exp $
.\"
.\" Copyright (c) 2018 Reyk Floeter <reyk@openbsd.org>
.\"
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.\" purpose with or without fee is hereby granted, provided that the above
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.Dd $Mdocdate: February 10 2021 $
.Dt LDAP 1
.Os
.Sh NAME
.Nm ldap
.Nd simple LDAP client
.Sh SYNOPSIS
.Nm ldap
.Cm search
.Op Fl LvWxZ
.Op Fl b Ar basedn
.Op Fl c Ar CAfile
.Op Fl D Ar binddn
.Op Fl H Ar host
.Op Fl l Ar timelimit
.Op Fl s Ar scope
.Op Fl w Ar secret
.Op Fl y Ar secretfile
.Op Fl z Ar sizelimit
.Op Ar filter
.Op Ar attributes ...
.Sh DESCRIPTION
The
.Nm
utility is a simple LDAP client.
It queries an LDAP server to perform a command and outputs the results
in the LDAP Data Interchange Format (LDIF).
.Bl -tag -width Ds
.It Cm search Ar options Oo Ar filter Oc Op Ar attributes ...
Perform a directory search request.
The optional
.Ar filter
argument specifies the LDAP filter for the directory search.
The default is
.Ar (objectClass=*)
and the format must comply to the
.Dq String Representation of Search Filters
as described in RFC 4515.
If one or more
.Ar attribute
options are specified,
.Nm
restricts the output to the specified attributes.
.El
.Pp
The options are as follows:
.Bl -tag -width Ds
.It Fl b Ar basedn
Use the specified distinguished name (dn) as the starting point for
directory search requests.
.It Fl c Ar CAfile
When TLS is enabled, load the CA bundle for certificate verification
from the specified file.
The default is
.Pa /etc/ssl/cert.pem .
If the LDAP server uses a self-signed certificate,
use a file that contains the server certificate in PEM format, e.g.
.Pa /etc/ssl/ldapserver.example.com.crt .
.It Fl D Ar binddn
Use the specified distinguished name to bind to the directory.
.It Fl H Ar host
The hostname of the LDAP server or an LDAP URL.
The LDAP URL is described in RFC 4516 with the following format:
.Pp
.Sm off
.Op Ar protocol No ://
.Ar host Op : Ar port
.Oo
.Li / Ar basedn
.Li ?\& Ar attribute , ...
.Li ?\& Ar scope
.Li ?\& Ar filter
.Oc
.Sm on
.Pp
The default is
.Ar ldap://localhost:389/ .
Each of
.Ar basedn , attribute , scope
and
.Ar filter
may be omitted,
but the preceding
.Sq /
or
.Sq ?\&
is required if a subsequent field is non-empty.
.Pp
The following protocols are supported:
.Pp
.Bl -tag -width "ldap+tls" -compact
.It ldap
Connect with TCP in plain text.
This is the default.
.It ldaps
Connect with TLS.
The default port is 636.
.It ldap+tls
Connect with TCP and enable TLS using the StartTLS operation.
This is the same as the
.Fl Z
option.
.It ldapi
Connect to a UNIX-domain socket.
The host argument is required to be a URL-encoded path, for example
.Ar ldapi://%2fvar%2frun%2fldapi
for
.Pa /var/run/ldapi .
.El
.It Fl L
Output the directory search result in a standards-compliant version of
the LDAP Data Interchange Format (LDIF).
This encodes attribute values that include non-printable or UTF-8
characters in the Base64 format and wraps lines at a 79-character limit.
If this option is not specified,
.Nm
encodes
.Dq unsafe
characters and newlines in a visual format using
.Xr vis 3
instead.
.It Fl l Ar timelimit
Request the server to abort the search request after
.Ar timelimit
seconds.
The default value is 0 for no limit.
.It Fl s Ar scope
Specify the
.Ar scope
to be either
.Ic base ,
.Ic one ,
or
.Ic sub .
The default is
.Ic sub
for subtree searches.
.It Fl v
Produce more verbose output.
.It Fl W
Prompt for the bind secret with echo turned off.
.It Fl w Ar secret
Specify the bind secret on the command line.
.It Fl x
Use simple authentication.
This is the default as
.Nm
does not support SASL authentication.
.It Fl y Ar secretfile
Read the bind secret from the first line of the specified file or from
standard input if the
.Ar secretfile
argument is
.Sq - .
The file must not be world-readable if it is a regular file.
.It Fl Z
Enable TLS using the StartTLS operation.
.It Fl z Ar sizelimit
Request the server to limit the search result to a maximum number of
.Ar sizelimit
entries.
The default value is 0 for no limit.
.El
.Sh FILES
.Bl -tag -width "/etc/ssl/cert.pemXXX" -compact
.It Pa /etc/ssl/cert.pem
Default CA file.
.El
.Sh EXAMPLES
The following script can be used with the
.Ar AuthorizedKeysCommand
option of
.Xr sshd 8 :
.Bd -literal -offset indent
#!/bin/sh
ldap search -D cn=Reader,dc=example,dc=com -w mypass123 \e
	-b ou=People,dc=example,dc=com \e
	-H ldapserver -c /etc/ssl/ldapserver.crt -Z \e
	"(&(objectClass=bsdAccount)(uid=$1))" sshPublicKey | \e
	sed 's/^sshPublicKey: //p;d;'
exit 0
.Ed
.Pp
And the related configuration in
.Xr sshd_config 5 :
.Bd -literal -offset indent
Match Group ldapusers
	AuthorizedKeysCommand /etc/ssh/ldap-authorized_keys.sh
	AuthorizedKeysCommandUser _ldap
.Ed
.Sh SEE ALSO
.Xr sshd_config 5 ,
.Xr ldapd 8 ,
.Xr sshd 8
.Sh STANDARDS
.Rs
.%A G. Good
.%D June 2000
.%R RFC 2849
.%T The LDAP Data Interchange Format (LDIF) - Technical Specification
.Re
.Pp
.Rs
.%A M. Smith, Ed.
.%A T. Howes
.%D June 2006
.%R RFC 4515
.%T Lightweight Directory Access Protocol (LDAP): String Representation of Search Filters
.Re
.Pp
.Rs
.%A M. Smith, Ed.
.%A T. Howes
.%D June 2006
.%R RFC 4516
.%T Lightweight Directory Access Protocol (LDAP): Uniform Resource Locator
.Re
.Sh HISTORY
The
.Nm
utility first appeared in
.Ox 6.4 .
.Sh AUTHORS
.An -nosplit
The
.Nm
utility was written by
.An Reyk Floeter Aq Mt reyk@openbsd.org .
.Sh CAVEATS
SASL authentication is not supported.
Authentication should be performed using simple authentication over a
TLS connection.