ldap.conf, .ldaprc - LDAP configuration file/environment variables
/etc/ldap/ldap.conf, ldaprc, .ldaprc, $LDAP<option-name>
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.
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.
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.
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.
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.
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.
- 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
- /etc/ldap/ldap.conf
- system-wide ldap configuration file
- $HOME/ldaprc, $HOME/.ldaprc
- user ldap configuration file
- $CWD/ldaprc
- local ldap configuration file
ldap(3),
ldap_set_option(3),
ldap_result(3),
openssl(1),
sasl(3)
Kurt Zeilenga, The OpenLDAP Project
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.