ldap.conf(5) — Linux manual page

NAME | SYNOPSIS | DESCRIPTION | SYNTAX | OPTIONS | SASL OPTIONS | GSSAPI OPTIONS | TLS OPTIONS | ENVIRONMENT VARIABLES | FILES | SEE ALSO | AUTHOR | ACKNOWLEDGEMENTS | COLOPHON

LDAP.CONF(5)                 File Formats Manual                LDAP.CONF(5)

NAME         top

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

SYNOPSIS         top

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

DESCRIPTION         top

       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         top

       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         top

       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.

       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.

       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         top

       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 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.

       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         top

       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         top

       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.

       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.

       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 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.  <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         top

       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         top

       ETCDIR/ldap.conf
              system-wide ldap configuration file

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

       $CWD/ldaprc
              local ldap configuration file

SEE ALSO         top

       ldap(3), ldap_set_option(3), ldap_result(3), openssl(1), sasl(3)

AUTHOR         top

       Kurt Zeilenga, The OpenLDAP Project

ACKNOWLEDGEMENTS         top

       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.

COLOPHON         top

       This page is part of the OpenLDAP (an open source implementation of
       the Lightweight Directory Access Protocol) project.  Information
       about the project can be found at ⟨http://www.openldap.org/⟩.  If you
       have a bug report for this manual page, see
       ⟨http://www.openldap.org/its/⟩.  This page was obtained from the
       project's upstream Git repository
       ⟨https://git.openldap.org/openldap/openldap.git⟩ on 2020-11-01.  (At
       that time, the date of the most recent commit that was found in the
       repository was 2020-10-30.)  If you discover any rendering problems
       in this HTML version of the page, or you believe there is a better or
       more up-to-date source for the page, or you have corrections or im‐
       provements to the information in this COLOPHON (which is not part of
       the original manual page), send a mail to man-pages@man7.org

OpenLDAP LDVERSION               RELEASEDATE                    LDAP.CONF(5)

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