Ubuntu Manpage: ldap.conf, .ldaprc - LDAP configuration file/environment variables

Provided by: libldap-common_2.5.18+dfsg-0ubuntu0.22.04.2_all

NAME

       ldap.conf, .ldaprc - LDAP configuration file/environment variables

SYNOPSIS

       /etc/ldap/ldap.conf, ldaprc, .ldaprc, $LDAP<option-name>

DESCRIPTION

If the environment variable LDAPNOINIT is defined, all defaulting is disabled.

The ldap.conf configuration file is used to set system-wide defaults to be applied when
running ldap clients.

Users may create an optional configuration file, ldaprc or .ldaprc, in their home
directory which will be used to override the system-wide defaults file. The file ldaprc
in the current working directory is also used.

Additional configuration files can be specified using the LDAPCONF and LDAPRC environment
variables. LDAPCONF may be set to the path of a configuration file. This path can be
absolute or relative to the current working directory. The LDAPRC, if defined, should be
the basename of a file in the current working directory or in the user's home directory.

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 LDAP. For example, to define BASE
via the environment, set the variable LDAPBASE to the desired value.

Some options are user-only. Such options are ignored if present in the ldap.conf (or file
specified by LDAPCONF).

Thus the following files and variables are read, in order:
variable $LDAPNOINIT, and if that is not set:
system file /etc/ldap/ldap.conf,
user files $HOME/ldaprc, $HOME/.ldaprc, ./ldaprc,
system file $LDAPCONF,
user files $HOME/$LDAPRC, $HOME/.$LDAPRC, ./$LDAPRC,
variables $LDAP<uppercase option name>.
Settings late in the list override earlier ones.

SYNTAX

       The configuration options are case-insensitive; their value, on a case by case basis,  may
       be case-sensitive.

       Blank lines are ignored.
       Lines beginning with a hash mark (`#') are comments, and ignored.

       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,

            # 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

       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.

OPTIONS

The different configuration options are:

URI <ldap[si]://[name[:port]] ...>
Specifies the URI(s) of an LDAP server(s) to which the LDAP library should connect.
The URI scheme may be any of ldap, ldaps or 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, name is the
name of the socket, and no 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.

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.

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. This is a user-only
option.

DEREF <when>
Specifies how alias dereferencing is done when performing a search. The <when> can
be specified as one of the following keywords:

never Aliases are never dereferenced. This is the default.

searching
Aliases are dereferenced in subordinates of the base object, but not in
locating the base object of the search.

finding
Aliases are only dereferenced when locating the base object of the search.

always Aliases are dereferenced both in searching and in locating the base object
of the search.

HOST <name[:port] ...>
Specifies the name(s) of an LDAP server(s) to which the 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. HOST is deprecated
in favor of URI.

KEEPALIVE_IDLE
Sets/gets the number of seconds a connection needs to remain idle before TCP starts
sending keepalive probes. Linux only.

KEEPALIVE_PROBES
Sets/gets the maximum number of keepalive probes TCP should send before dropping
the connection. Linux only.

KEEPALIVE_INTERVAL
Sets/gets the interval in seconds between individual keepalive probes. Linux only.

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.

PORT <port>
Specifies the default port used when connecting to LDAP servers(s). The port may
be specified as a number. PORT is deprecated in favor of URI.

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 ldapsearch(1) &co
always override this option.

SIZELIMIT <integer>
Specifies a size limit (number of entries) to use when performing searches. The
number should be a non-negative integer. SIZELIMIT 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.

SOCKET_BIND_ADDRESSES <IP>
Specifies the source bind IP to be used for connecting to target LDAP server.
Multiple IP addresses must be space separated. Only one valid IPv4 address and/or
one valid IPv6 address are allowed in the list.

TIMELIMIT <integer>
Specifies a time limit (in seconds) to use when performing searches. The number
should be a non-negative integer. TIMELIMIT 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.

VERSION {2|3}
Specifies what version of the LDAP protocol should be used.

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 ldap_result(3) calls where a
NULL timeout parameter is supplied.

SASL OPTIONS

If OpenLDAP is built with Simple Authentication and Security Layer support, there are more
options you can specify.

SASL_MECH <mechanism>
Specifies the SASL mechanism to use.

SASL_REALM <realm>
Specifies the SASL realm.

SASL_AUTHCID <authcid>
Specifies the authentication identity. This is a user-only option.

SASL_AUTHZID <authcid>
Specifies the proxy authorization identity. This is a user-only option.

SASL_SECPROPS <properties>
Specifies Cyrus SASL security properties. The <properties> can be specified as a
comma-separated list of the following:

none (without any other properties) causes the properties defaults
("noanonymous,noplain") to be cleared.

noplain
disables mechanisms susceptible to simple passive attacks.

noactive
disables mechanisms susceptible to active attacks.

nodict disables mechanisms susceptible to passive dictionary attacks.

noanonymous
disables mechanisms which support anonymous login.

forwardsec
requires forward secrecy between sessions.

passcred
requires mechanisms which pass client credentials (and allows mechanisms
which can pass credentials to do so).

minssf=<factor>
specifies the minimum acceptable 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.

maxssf=<factor>
specifies the maximum acceptable security strength factor as an integer (see
minssf description). The default is INT_MAX.

maxbufsize=<factor>
specifies the maximum security layer receive buffer size allowed. 0
disables security layers. The default is 65536.

SASL_NOCANON <on/true/yes/off/false/no>
Do not perform reverse DNS lookups to canonicalize SASL host names. The default is
off.

SASL_CBINDING <none/tls-unique/tls-endpoint>
The channel-binding type to use, see also LDAP_OPT_X_SASL_CBINDING. The default is
none.

GSSAPI OPTIONS

       If OpenLDAP is built with Generic  Security  Services  Application  Programming  Interface
       support, there are more options you can specify.

       GSSAPI_SIGN <on/true/yes/off/false/no>
              Specifies if GSSAPI signing (GSS_C_INTEG_FLAG) should be used.  The default is off.

       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.

       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.

TLS OPTIONS

If OpenLDAP is built with Transport Layer Security support, there are more options you can
specify. These options are used when an ldaps:// URI is selected (by default or
otherwise) or when the application negotiates TLS by issuing the LDAP StartTLS operation.

TLS_CACERT <filename>
Specifies the file that contains certificates for all of the Certificate
Authorities the client will recognize.

TLS_CACERTDIR <path>
Specifies the path of a directory that contains Certificate Authority certificates
in separate individual files. The TLS_CACERT is always used before TLS_CACERTDIR.

TLS_CERT <filename>
Specifies the file that contains the client certificate. This is a user-only
option.

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.

TLS_KEY <filename>
Specifies the file that contains the private key that matches the certificate
stored in the 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. This is a user-only option.

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:

OpenSSL:
TLS_CIPHER_SUITE HIGH:MEDIUM:+SSLv2

GnuTLS:
TLS_CIPHER_SUITE SECURE256:!AES-128-CBC

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

openssl ciphers -v <cipher-suite-spec>

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

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

gnutls-cli -l

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.,

TLS_PROTOCOL_MIN 3.2

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. On Debian openldap is linked
against GnuTLS.

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. On Debian openldap is linked against GnuTLS.

TLS_REQCERT <level>
Specifies what checks to perform on server certificates in a TLS session. The
<level> can be specified as one of the following keywords:

never The client will not request or check any server certificate.

allow The server certificate is requested. If a bad certificate is provided, it
will be ignored and the session proceeds normally.

try The server certificate is requested. If a bad certificate is provided, the
session is immediately terminated.

demand | hard
These keywords are equivalent and the same as try. This is the default
setting.

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 <level> can be specified as one of the following
keywords:

never The client will not check any SAN in the certificate.

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.

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.

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.

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
TLS_CACERTDIR parameter to be set. This parameter is ignored with GnuTLS. On Debian
openldap is linked against GnuTLS. <level> can be specified as one of the
following keywords:

none No CRL checks are performed

peer Check the CRL of the peer certificate

all Check the CRL for a whole certificate chain

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.

ENVIRONMENT VARIABLES

       LDAPNOINIT
              disable all defaulting

       LDAPCONF
              path of a configuration file

       LDAPRC basename of ldaprc file in $HOME or $CWD

       LDAP<option-name>
              Set <option-name> as from ldap.conf

FILES

       /etc/ldap/ldap.conf
              system-wide ldap configuration file

       $HOME/ldaprc, $HOME/.ldaprc
              user ldap configuration file

       $CWD/ldaprc
              local ldap configuration file

AUTHOR

       Kurt Zeilenga, The OpenLDAP Project

ACKNOWLEDGEMENTS

       OpenLDAP    Software    is    developed   and   maintained   by   The   OpenLDAP   Project
       <http://www.openldap.org/>.  OpenLDAP Software is derived from the University of  Michigan
       LDAP 3.3 Release.