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NAME
ldap.conf, .ldaprc - LDAP configuration file/environment variables
SYNOPSIS
ETCDIR/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 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>.
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://
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# 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:
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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.
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.
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.
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.
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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.
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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 approximating the effective key length used for
encryption. 0 (zero) implies no protection, 1 implies
integrity protection only, 56 allows DES or other weak
ciphers, 112 allows triple DES and other strong ciphers, 128
allows RC4, Blowfish and other modern strong 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.
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
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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. This parameter is
ignored with GnuTLS.
When using Mozilla NSS, <path> may contain a Mozilla NSS cert/key
database. If <path> contains a Mozilla NSS cert/key database and
CA cert files, OpenLDAP will use the cert/key database and will
ignore the CA cert files.
TLS_CERT <filename>
Specifies the file that contains the client certificate. This is
a user-only option.
When using Mozilla NSS, if using a cert/key database (specified
with TLS_CACERTDIR), TLS_CERT specifies the name of the
certificate to use:
TLS_CERT Certificate for Sam Carter
If using a token other than the internal built in token, specify
the token name first, followed by a colon:
TLS_CERT my hardware device:Certificate for Sam Carter
Use certutil -L to list the certificates by name:
certutil -d /path/to/certdbdir -L
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.
When using Mozilla NSS, TLS_KEY specifies the name of a file that
contains the password for the key for the certificate specified
with TLS_CERT. The modutil command can be used to turn off
password protection for the cert/key database. For example, if
TLS_CACERTDIR specifies /home/scarter/.moznss as the location of
the cert/key database, use modutil to change the password to the
empty string:
modutil -dbdir ~/.moznss -changepw 'NSS Certificate DB'
You must have the old password, if any. Ignore the WARNING about
the running browser. Press 'Enter' for the new password.
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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, GnuTLS, or Mozilla NSS). 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
When using Mozilla NSS, the OpenSSL cipher suite specifications
are used and translated into the format used internally by
Mozilla NSS. There isn't an easy way to list the cipher suites
from the command line. The authoritative list is in the source
code for Mozilla NSS in the file sslinfo.c in the structure
static const SSLCipherSuiteInfo suiteInfo[]
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.
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 and
Mozilla NSS.
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TLS_REQCERT <level>
Specifies what checks to perform on server certificates in a TLS
session, if any. 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 no certificate is
provided, the session proceeds normally. If a bad
certificate is provided, it will be ignored and the session
proceeds normally.
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.
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.
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
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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 and Mozilla NSS. <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 and Mozilla NSS.
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
ETCDIR/ldap.conf
system-wide ldap configuration file
$HOME/ldaprc, $HOME/.ldaprc
user ldap configuration file
$CWD/ldaprc
local ldap configuration file
SEE ALSO
ldap(3), ldap_set_option(3), ldap_result(3), openssl(1), sasl(3)
AUTHOR
Kurt Zeilenga, The OpenLDAP Project
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ACKNOWLEDGEMENTS
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