openldap/doc/man/man5/ldap.conf.5

.TH LDAP.CONF 5 "RELEASEDATE" "OpenLDAP LDVERSION"
.\" $OpenLDAP$
.\" Copyright 1998-2021 The OpenLDAP Foundation All Rights Reserved.
.\" Copying restrictions apply.  See COPYRIGHT/LICENSE.
.SH NAME
ldap.conf, .ldaprc \- LDAP configuration file/environment variables
.SH SYNOPSIS
ETCDIR/ldap.conf, ldaprc, .ldaprc, $LDAP<option-name>
.SH DESCRIPTION
If the environment variable \fBLDAPNOINIT\fP is defined, all
defaulting is disabled.
.LP
The
.I ldap.conf
configuration file is used to set system-wide defaults to be applied when
running
.I ldap
clients.
.LP
Users may create an optional configuration file,
.I ldaprc
or
.IR .ldaprc ,
in their home directory which will be used to override the system-wide
defaults file.
The file
.I ldaprc
in the current working directory is also used.
.LP
.LP
Additional configuration files can be specified using
the \fBLDAPCONF\fP and \fBLDAPRC\fP environment variables.
\fBLDAPCONF\fP may be set to the path of a configuration file.  This
path can be absolute or relative to the current working directory.
The \fBLDAPRC\fP, if defined, should be the basename of a file
in the current working directory or in the user's home directory.
.LP
Environmental variables may also be used to augment the file based defaults.
The name of the variable is the option name with an added prefix of \fBLDAP\fP.
For example, to define \fBBASE\fP via the environment, set the variable
\fBLDAPBASE\fP to the desired value.
.LP
Some options are user-only.  Such options are ignored if present
in the
.I ldap.conf
(or file specified by
.BR LDAPCONF ).
.LP
Thus the following files and variables are read, in order:
.nf
    variable     $LDAPNOINIT, and if that is not set:
    system file  ETCDIR/ldap.conf,
    user files   $HOME/ldaprc,  $HOME/.ldaprc,  ./ldaprc,
    system file  $LDAPCONF,
    user files   $HOME/$LDAPRC, $HOME/.$LDAPRC, ./$LDAPRC,
    variables    $LDAP<uppercase option name>.
.fi
Settings late in the list override earlier ones.
.SH SYNTAX
The configuration options are case-insensitive;
their value, on a case by case basis, may be case-sensitive.
.LP
Blank lines are ignored.
.br
Lines beginning with a hash mark (`#') are comments, and ignored.
.LP
Valid lines are made of an option's name (a sequence of non-blanks,
conventionally written in uppercase, although not required), 
followed by a value.
The value starts with the first non-blank character after 
the option's name, and terminates at the end of the line, 
or at the last sequence of blanks before the end of the line.
The tokenization of the value, if any, is delegated to the handler(s)
for that option, if any.  Quoting values that contain blanks 
may be incorrect, as the quotes would become part of the value.
For example,

.nf
	# Wrong - erroneous quotes:
	URI     "ldap:// ldaps://"

	# Right - space-separated list of URIs, without quotes:
	URI     ldap:// ldaps://

	# Right - DN syntax needs quoting for Example, Inc:
	BASE    ou=IT staff,o="Example, Inc",c=US
	# or:
	BASE    ou=IT staff,o=Example\\2C Inc,c=US

	# Wrong - comment on same line as option:
	DEREF   never           # Never follow aliases
.fi
.LP
A line cannot be longer than LINE_MAX, which should be more than 2000 bytes
on all platforms.
There is no mechanism to split a long line on multiple lines, either for
beautification or to overcome the above limit.
.SH OPTIONS
The different configuration options are:
.TP
.B URI <ldap[si]://[name[:port]] ...>
Specifies the URI(s) of an LDAP server(s) to which the
.I LDAP 
library should connect.  The URI scheme may be any of
.BR ldap ,
.B ldaps 
or
.BR ldapi ,
which refer to LDAP over TCP, LDAP over SSL (TLS) and LDAP
over IPC (UNIX domain sockets), respectively.
Each server's name can be specified as a
domain-style name or an IP address literal.  Optionally, the
server's name can followed by a ':' and the port number the LDAP
server is listening on.  If no port number is provided, the default
port for the scheme is used (389 for ldap://, 636 for ldaps://).
For LDAP over IPC,
.B name 
is the name of the socket, and no
.B port
is required, nor allowed; note that directory separators must be 
URL-encoded, like any other characters that are special to URLs; 
so the socket

	/usr/local/var/ldapi

must be specified as

	ldapi://%2Fusr%2Flocal%2Fvar%2Fldapi

A space separated list of URIs may be provided.
.TP
.B BASE <base>
Specifies the default base DN to use when performing ldap operations.
The base must be specified as a Distinguished Name in LDAP format.
.TP
.B BINDDN <dn>
Specifies the default bind DN to use when performing ldap operations.
The bind DN must be specified as a Distinguished Name in LDAP format.
.B This is a user-only option.
.TP
.B DEREF <when>
Specifies how alias dereferencing is done when performing a search. The
.B <when>
can be specified as one of the following keywords:
.RS
.TP
.B never
Aliases are never dereferenced. This is the default.
.TP
.B searching
Aliases are dereferenced in subordinates of the base object, but
not in locating the base object of the search.
.TP
.B finding
Aliases are only dereferenced when locating the base object of the search.
.TP
.B always
Aliases are dereferenced both in searching and in locating the base object
of the search.
.RE
.TP
.TP
.B HOST <name[:port] ...>
Specifies the name(s) of an LDAP server(s) to which the
.I LDAP 
library should connect.  Each server's name can be specified as a
domain-style name or an IP address and optionally followed by a ':' and
the port number the ldap server is listening on.  A space separated
list of hosts may be provided.
.B HOST
is deprecated in favor of
.BR URI .
.TP
.B NETWORK_TIMEOUT <integer>
Specifies the timeout (in seconds) after which the poll(2)/select(2)
following a connect(2) returns in case of no activity.
.TP
.B PORT <port>
Specifies the default port used when connecting to LDAP servers(s).
The port may be specified as a number.
.B PORT
is deprecated in favor of
.BR URI.
.TP
.B REFERRALS <on/true/yes/off/false/no>
Specifies if the client should automatically follow referrals returned
by LDAP servers.
The default is on.
Note that the command line tools
.BR ldapsearch (1)
&co always override this option.
.\" This should only be allowed via ldap_set_option(3)
.\".TP
.\".B RESTART <on/true/yes/off/false/no>
.\"Determines whether the library should implicitly restart connections (FIXME).
.TP
.B SIZELIMIT <integer>
Specifies a size limit (number of entries) to use when performing searches.
The number should be a non-negative integer.  \fISIZELIMIT\fP of zero (0)
specifies a request for unlimited search size.  Please note that the server
may still apply any server-side limit on the amount of entries that can be 
returned by a search operation.
.TP
.B TIMELIMIT <integer>
Specifies a time limit (in seconds) to use when performing searches.
The number should be a non-negative integer.  \fITIMELIMIT\fP of zero (0)
specifies unlimited search time to be used.  Please note that the server
may still apply any server-side limit on the duration of a search operation.
.TP
.B VERSION {2|3}
Specifies what version of the LDAP protocol should be used.
.TP
.B TIMEOUT <integer>
Specifies a timeout (in seconds) after which calls to synchronous LDAP
APIs will abort if no response is received.  Also used for any
.BR ldap_result (3)
calls where a NULL timeout parameter is supplied.
.SH SASL OPTIONS
If OpenLDAP is built with Simple Authentication and Security Layer support,
there are more options you can specify.
.TP
.B SASL_MECH <mechanism>
Specifies the SASL mechanism to use.
.TP
.B SASL_REALM <realm>
Specifies the SASL realm.
.TP
.B SASL_AUTHCID <authcid>
Specifies the authentication identity.
.B This is a user-only option.
.TP
.B SASL_AUTHZID <authcid>
Specifies the proxy authorization identity.
.B This is a user-only option.
.TP
.B SASL_SECPROPS <properties>
Specifies Cyrus SASL security properties. The 
.B <properties>
can be specified as a comma-separated list of the following:
.RS
.TP
.B none
(without any other properties) causes the properties
defaults ("noanonymous,noplain") to be cleared.
.TP
.B noplain
disables mechanisms susceptible to simple passive attacks.
.TP
.B noactive
disables mechanisms susceptible to active attacks.
.TP
.B nodict
disables mechanisms susceptible to passive dictionary attacks.
.TP
.B noanonymous
disables mechanisms which support anonymous login.
.TP
.B forwardsec
requires forward secrecy between sessions.
.TP
.B passcred
requires mechanisms which pass client credentials (and allows
mechanisms which can pass credentials to do so).
.TP
.B minssf=<factor> 
specifies the minimum acceptable
.I security strength factor
as an integer approximate to effective key length used for
encryption.  0 (zero) implies no protection, 1 implies integrity
protection only, 128 allows RC4, Blowfish and other similar ciphers,
256 will require modern ciphers.  The default is 0.
.TP
.B maxssf=<factor> 
specifies the maximum acceptable
.I security strength factor
as an integer (see
.B minssf
description).  The default is
.BR INT_MAX .
.TP
.B maxbufsize=<factor> 
specifies the maximum security layer receive buffer
size allowed.  0 disables security layers.  The default is 65536.
.RE
.TP
.B SASL_NOCANON <on/true/yes/off/false/no>
Do not perform reverse DNS lookups to canonicalize SASL host names. The default is off.
.TP
.B SASL_CBINDING <none/tls-unique/tls-endpoint>
The channel-binding type to use, see also LDAP_OPT_X_SASL_CBINDING. The default is none.
.SH GSSAPI OPTIONS
If OpenLDAP is built with Generic Security Services Application Programming Interface support,
there are more options you can specify.
.TP
.B GSSAPI_SIGN <on/true/yes/off/false/no>
Specifies if GSSAPI signing (GSS_C_INTEG_FLAG) should be used.
The default is off.
.TP
.B GSSAPI_ENCRYPT <on/true/yes/off/false/no>
Specifies if GSSAPI encryption (GSS_C_INTEG_FLAG and GSS_C_CONF_FLAG)
should be used. The default is off.
.TP
.B GSSAPI_ALLOW_REMOTE_PRINCIPAL <on/true/yes/off/false/no>
Specifies if GSSAPI based authentication should try to form the
target principal name out of the ldapServiceName or dnsHostName
attribute of the targets RootDSE entry. The default is off.
.SH TLS OPTIONS
If OpenLDAP is built with Transport Layer Security support, there
are more options you can specify.  These options are used when an
.B ldaps:// URI
is selected (by default or otherwise) or when the application
negotiates TLS by issuing the LDAP StartTLS operation.
.TP
.B TLS_CACERT <filename>
Specifies the file that contains certificates for all of the Certificate
Authorities the client will recognize.
.TP
.B TLS_CACERTDIR <path>
Specifies the path of a directory that contains Certificate Authority
certificates in separate individual files. The
.B TLS_CACERT
is always used before
.B TLS_CACERTDIR.
.TP
.B TLS_CERT <filename>
Specifies the file that contains the client certificate.
.B This is a user-only option.
.TP
.B TLS_ECNAME <name>
Specify the name of the curve(s) to use for Elliptic curve Diffie-Hellman
ephemeral key exchange.  This option is only used for OpenSSL.
This option is not used with GnuTLS; the curves may be
chosen in the GnuTLS ciphersuite specification.
.TP
.B TLS_KEY <filename>
Specifies the file that contains the private key that matches the certificate
stored in the
.B TLS_CERT
file. Currently, the private key must not be protected with a password, so
it is of critical importance that the key file is protected carefully.
.B This is a user-only option.
.TP
.B TLS_CIPHER_SUITE <cipher-suite-spec>
Specifies acceptable cipher suite and preference order.
<cipher-suite-spec> should be a cipher specification for 
the TLS library in use (OpenSSL or GnuTLS).
Example:
.RS
.RS
.TP
.I OpenSSL:
TLS_CIPHER_SUITE HIGH:MEDIUM:+SSLv2
.TP
.I GnuTLS:
TLS_CIPHER_SUITE SECURE256:!AES-128-CBC
.RE

To check what ciphers a given spec selects in OpenSSL, use:

.nf
	openssl ciphers \-v <cipher-suite-spec>
.fi

With GnuTLS the available specs can be found in the manual page of 
.BR gnutls\-cli (1)
(see the description of the 
option
.BR \-\-priority ).

In older versions of GnuTLS, where gnutls\-cli does not support the option
\-\-priority, you can obtain the \(em more limited \(em list of ciphers by calling:

.nf
	gnutls\-cli \-l
.fi
.RE
.TP
.B TLS_PROTOCOL_MIN <major>[.<minor>]
Specifies minimum SSL/TLS protocol version that will be negotiated.
If the server doesn't support at least that version,
the SSL handshake will fail.
To require TLS 1.x or higher, set this option to 3.(x+1),
e.g.,

.nf
	TLS_PROTOCOL_MIN 3.2
.fi

would require TLS 1.1.
Specifying a minimum that is higher than that supported by the
OpenLDAP implementation will result in it requiring the
highest level that it does support.
This parameter is ignored with GnuTLS.
.TP
.B TLS_RANDFILE <filename>
Specifies the file to obtain random bits from when /dev/[u]random is
not available. Generally set to the name of the EGD/PRNGD socket.
The environment variable RANDFILE can also be used to specify the filename.
This parameter is ignored with GnuTLS.
.TP
.B TLS_REQCERT <level>
Specifies what checks to perform on server certificates in a TLS session,
if any. The
.B <level>
can be specified as one of the following keywords:
.RS
.TP
.B never
The client will not request or check any server certificate.
.TP
.B allow
The server certificate is requested. If no certificate is provided,
the session proceeds normally. If a bad certificate is provided, it will
be ignored and the session proceeds normally.
.TP
.B try
The server certificate is requested. If no certificate is provided,
the session proceeds normally. If a bad certificate is provided,
the session is immediately terminated.
.TP
.B demand | hard
These keywords are equivalent. The server certificate is requested. If no
certificate is provided, or a bad certificate is provided, the session
is immediately terminated. This is the default setting.
.RE
.TP
.B TLS_REQSAN <level>
Specifies what checks to perform on the subjectAlternativeName
(SAN) extensions in a server certificate when validating the certificate
name against the specified hostname of the server. The
.B <level>
can be specified as one of the following keywords:
.RS
.TP
.B never
The client will not check any SAN in the certificate.
.TP
.B allow
The SAN is checked against the specified hostname. If a SAN is
present but none match the specified hostname, the SANs are ignored
and the usual check against the certificate DN is used.
This is the default setting.
.TP
.B try
The SAN is checked against the specified hostname. If no SAN is present
in the server certificate, the usual check against the certificate DN
is used. If a SAN is present but doesn't match the specified hostname,
the session is immediately terminated. This setting may be preferred
when a mix of certs with and without SANs are in use.
.TP
.B demand | hard
These keywords are equivalent. The SAN is checked against the specified
hostname. If no SAN is present in the server certificate, or no SANs
match, the session is immediately terminated. This setting should be
used when only certificates with SANs are in use.
.RE
.TP
.B TLS_CRLCHECK <level>
Specifies if the Certificate Revocation List (CRL) of the CA should be 
used to verify if the server certificates have not been revoked. This
requires
.B TLS_CACERTDIR
parameter to be set. This parameter is ignored with GnuTLS.
.B <level>
can be specified as one of the following keywords:
.RS
.TP
.B none
No CRL checks are performed
.TP
.B peer
Check the CRL of the peer certificate
.TP
.B all
Check the CRL for a whole certificate chain
.RE
.TP
.B TLS_CRLFILE <filename>
Specifies the file containing a Certificate Revocation List to be used
to verify if the server certificates have not been revoked. This
parameter is only supported with GnuTLS.
.SH "ENVIRONMENT VARIABLES"
.TP
LDAPNOINIT
disable all defaulting
.TP
LDAPCONF
path of a configuration file
.TP
LDAPRC
basename of ldaprc file in $HOME or $CWD
.TP
LDAP<option-name>
Set <option-name> as from ldap.conf
.SH FILES
.TP
.I  ETCDIR/ldap.conf
system-wide ldap configuration file
.TP
.I  $HOME/ldaprc, $HOME/.ldaprc
user ldap configuration file
.TP
.I  $CWD/ldaprc
local ldap configuration file
.SH "SEE ALSO"
.BR ldap (3),
.BR ldap_set_option (3),
.BR ldap_result (3),
.BR openssl (1),
.BR sasl (3)
.SH AUTHOR
Kurt Zeilenga, The OpenLDAP Project
.SH ACKNOWLEDGEMENTS
.so ../Project