slapd-config(5) — Linux manual page


SLAPD-CONFIG(5)            File Formats Manual           SLAPD-CONFIG(5)

NAME         top

       slapd-config - configuration backend to slapd

SYNOPSIS         top


DESCRIPTION         top

       The config backend manages all of the configuration information
       for the slapd(8) daemon.  This configuration information is also
       used by the SLAPD tools slapacl(8), slapadd(8), slapauth(8),
       slapcat(8), slapdn(8), slapindex(8), slapmodify(8), and

       The config backend is backward compatible with the older
       slapd.conf(5) file but provides the ability to change the
       configuration dynamically at runtime. If slapd is run with only a
       slapd.conf file dynamic changes will be allowed but they will not
       persist across a server restart. Dynamic changes are only saved
       when slapd is running from a slapd.d configuration directory.

       Unlike other backends, there can only be one instance of the
       config backend, and most of its structure is predefined. The root
       of the database is hardcoded to cn=config and this root entry
       contains global settings for slapd. Multiple child entries
       underneath the root entry are used to carry various other

                     dynamically loaded modules

                     schema definitions

                     backend-specific settings

                     database-specific settings

       The cn=Module entries will only appear in configurations where
       slapd was built with support for dynamically loaded modules.
       There can be multiple entries, one for each configured module
       path. Within each entry there will be values recorded for each
       module loaded on a given path. These entries have no children.

       The cn=Schema entry contains all of the hardcoded schema
       elements.  The children of this entry contain all user-defined
       schema elements.  In schema that were loaded from include files,
       the child entry will be named after the include file from which
       the schema was loaded.  Typically the first child in this subtree
       will be cn=core,cn=schema,cn=config.

       olcBackend entries are for storing settings specific to a single
       backend type (and thus global to all database instances of that
       type).  At present, only back-mdb implements any options of this
       type, so this setting is not needed for any other backends.

       olcDatabase entries store settings specific to a single database
       instance. These entries may have olcOverlay child entries
       corresponding to any overlays configured on the database. The
       olcDatabase and olcOverlay entries may also have miscellaneous
       child entries for other settings as needed. There are two special
       database entries that are predefined - one is an entry for the
       config database itself, and the other is for the "frontend"
       database. Settings in the frontend database are inherited by the
       other databases, unless they are explicitly overridden in a
       specific database.

       The specific configuration options available are discussed below
       in the Global Configuration Options, General Backend Options, and
       General Database Options. Options are set by defining LDAP
       attributes with specific values.  In general the names of the
       LDAP attributes are the same as the corresponding slapd.conf
       keyword, with an "olc" prefix added on.

       The parser for many of these attributes is the same as used for
       parsing the slapd.conf keywords. As such, slapd.conf keywords
       that allow multiple items to be specified on one line, separated
       by whitespace, will allow multiple items to be specified in one
       attribute value. However, when reading the attribute via LDAP,
       the items will be returned as individual attribute values.

       Backend-specific options are discussed in the slapd-<backend>(5)
       manual pages.  Refer to the "OpenLDAP Administrator's Guide" for
       more details on configuring slapd.


       Options described in this section apply to the server as a whole.
       Arguments that should be replaced by actual text are shown in
       brackets <>.

       These options may only be specified in the cn=config entry. This
       entry must have an objectClass of olcGlobal.

       olcAllows: <features>
              Specify a set of features to allow (default none).
              bind_v2 allows acceptance of LDAPv2 bind requests.  Note
              that slapd(8) does not truly implement LDAPv2 (RFC 1777),
              now Historic (RFC 3494).  bind_anon_cred allows anonymous
              bind when credentials are not empty (e.g.  when DN is
              empty).  bind_anon_dn allows unauthenticated (anonymous)
              bind when DN is not empty.  update_anon allows
              unauthenticated (anonymous) update operations to be
              processed (subject to access controls and other
              administrative limits).  proxy_authz_anon allows
              unauthenticated (anonymous) proxy authorization control to
              be processed (subject to access controls, authorization
              and other administrative limits).

       olcArgsFile: <filename>
              The (absolute) name of a file that will hold the slapd
              server's command line (program name and options).

       olcAttributeOptions: <option-name>...
              Define tagging attribute options or option tag/range
              prefixes.  Options must not end with `-', prefixes must
              end with `-'.  The `lang-' prefix is predefined.  If you
              use the olcAttributeOptions directive, `lang-' will no
              longer be defined and you must specify it explicitly if
              you want it defined.

              An attribute description with a tagging option is a
              subtype of that attribute description without the option.
              Except for that, options defined this way have no special
              semantics.  Prefixes defined this way work like the
              `lang-' options: They define a prefix for tagging options
              starting with the prefix.  That is, if you define the
              prefix `x-foo-', you can use the option `x-foo-bar'.
              Furthermore, in a search or compare, a prefix or range
              name (with a trailing `-') matches all options starting
              with that name, as well as the option with the range name
              sans the trailing `-'.  That is, `x-foo-bar-' matches
              `x-foo-bar' and `x-foo-bar-baz'.

              RFC 4520 reserves options beginning with `x-' for private
              experiments.  Other options should be registered with
              IANA, see RFC 4520 section 3.5.  OpenLDAP also has the
              `binary' option built in, but this is a transfer option,
              not a tagging option.

       olcAuthIDRewrite: <rewrite-rule>
              Used by the authentication framework to convert simple
              user names to an LDAP DN used for authorization purposes.
              Its purpose is analogous to that of olcAuthzRegexp (see
              below).  The rewrite-rule is a set of rules analogous to
              those described in slapo-rwm(5) for data rewriting (after
              stripping the rwm- prefix).  olcAuthIDRewrite and
              olcAuthzRegexp should not be intermixed.

       olcAuthzPolicy: <policy>
              Used to specify which rules to use for Proxy
              Authorization.  Proxy authorization allows a client to
              authenticate to the server using one user's credentials,
              but specify a different identity to use for authorization
              and access control purposes. It essentially allows user A
              to login as user B, using user A's password.  The none
              flag disables proxy authorization. This is the default
              setting.  The from flag will use rules in the authzFrom
              attribute of the authorization DN.  The to flag will use
              rules in the authzTo attribute of the authentication DN.
              The any flag, an alias for the deprecated value of both,
              will allow any of the above, whatever succeeds first
              (checked in to, from sequence.  The all flag requires both
              authorizations to succeed.

              The rules are mechanisms to specify which identities are
              allowed to perform proxy authorization.  The authzFrom
              attribute in an entry specifies which other users are
              allowed to proxy login to this entry. The authzTo
              attribute in an entry specifies which other users this
              user can authorize as.  Use of authzTo rules can be easily
              abused if users are allowed to write arbitrary values to
              this attribute.  In general the authzTo attribute must be
              protected with ACLs such that only privileged users can
              modify it.  The value of authzFrom and authzTo describes
              an identity or a set of identities; it can take five



              The first form is a valid LDAP URI where the
              <host>:<port>, the <attrs> and the <extensions> portions
              must be absent, so that the search occurs locally on
              either authzFrom or authzTo.

              The second form is a DN, with the optional style modifiers
              exact, onelevel, children, and subtree for exact,
              onelevel, children and subtree matches, which cause
              <pattern> to be normalized according to the DN
              normalization rules, or the special regex style, which
              causes the <pattern> to be treated as a POSIX
              (''extended'') regular expression, as discussed in
              regex(7) and/or re_format(7).  A pattern of * means any
              non-anonymous DN.

              The third form is a SASL id, with the optional fields
              <mech> and <realm> that allow to specify a SASL mechanism,
              and eventually a SASL realm, for those mechanisms that
              support one.  The need to allow the specification of a
              mechanism is still debated, and users are strongly
              discouraged to rely on this possibility.

              The fourth form is a group specification.  It consists of
              the keyword group, optionally followed by the
              specification of the group objectClass and attributeType.
              The objectClass defaults to groupOfNames.  The
              attributeType defaults to member.  The group with DN
              <pattern> is searched with base scope, filtered on the
              specified objectClass.  The values of the resulting
              attributeType are searched for the asserted DN.

              The fifth form is provided for backwards compatibility.
              If no identity type is provided, i.e. only <pattern> is
              present, an exact DN is assumed; as a consequence,
              <pattern> is subjected to DN normalization.

              Since the interpretation of authzFrom and authzTo can
              impact security, users are strongly encouraged to
              explicitly set the type of identity specification that is
              being used.  A subset of these rules can be used as third
              arg in the olcAuthzRegexp statement (see below);
              significantly, the URI, provided it results in exactly one
              entry, and the dn.exact:<dn> forms.

       olcAuthzRegexp: <match> <replace>
              Used by the authentication framework to convert simple
              user names, such as provided by SASL subsystem, or
              extracted from certificates in case of cert-based SASL
              EXTERNAL, or provided within the RFC 4370 "proxied
              authorization" control, to an LDAP DN used for
              authorization purposes.  Note that the resulting DN need
              not refer to an existing entry to be considered valid.
              When an authorization request is received from the SASL
              subsystem, the SASL USERNAME, REALM, and MECHANISM are
              taken, when available, and combined into a name of the


              This name is then compared against the match POSIX
              (''extended'') regular expression, and if the match is
              successful, the name is replaced with the replace string.
              If there are wildcard strings in the match regular
              expression that are enclosed in parenthesis, e.g.


              then the portion of the name that matched the wildcard
              will be stored in the numbered placeholder variable $1. If
              there are other wildcard strings in parenthesis, the
              matching strings will be in $2, $3, etc. up to $9. The
              placeholders can then be used in the replace string, e.g.


              The replaced name can be either a DN, i.e. a string
              prefixed by "dn:", or an LDAP URI.  If the latter, the
              server will use the URI to search its own database(s) and,
              if the search returns exactly one entry, the name is
              replaced by the DN of that entry.   The LDAP URI must have
              no hostport, attrs, or extensions components, but the
              filter is mandatory, e.g.


              The protocol portion of the URI must be strictly ldap.
              Note that this search is subject to access controls.
              Specifically, the authentication identity must have "auth"
              access in the subject.

              Multiple olcAuthzRegexp values can be specified to allow
              for multiple matching and replacement patterns. The
              matching patterns are checked in the order they appear in
              the attribute, stopping at the first successful match.

       olcConcurrency: <integer>
              Specify a desired level of concurrency.  Provided to the
              underlying thread system as a hint.  The default is not to
              provide any hint. This setting is only meaningful on some
              platforms where there is not a one to one correspondence
              between user threads and kernel threads.

       olcConnMaxPending: <integer>
              Specify the maximum number of pending requests for an
              anonymous session.  If requests are submitted faster than
              the server can process them, they will be queued up to
              this limit. If the limit is exceeded, the session is
              closed. The default is 100.

       olcConnMaxPendingAuth: <integer>
              Specify the maximum number of pending requests for an
              authenticated session.  The default is 1000.

       olcDisallows: <features>
              Specify a set of features to disallow (default none).
              bind_anon disables acceptance of anonymous bind requests.
              Note that this setting does not prohibit anonymous
              directory access (See "require authc").  bind_simple
              disables simple (bind) authentication.  tls_2_anon
              disables forcing session to anonymous status (see also
              tls_authc) upon StartTLS operation receipt.  tls_authc
              disallows the StartTLS operation if authenticated (see
              also tls_2_anon).  proxy_authz_non_critical disables
              acceptance of the proxied authorization control (RFC4370)
              with criticality set to FALSE.  dontusecopy_non_critical
              disables acceptance of the dontUseCopy control (a work in
              progress) with criticality set to FALSE.

       olcGentleHUP: { TRUE | FALSE }
              A SIGHUP signal will only cause a 'gentle' shutdown-
              attempt: Slapd will stop listening for new connections,
              but will not close the connections to the current clients.
              Future write operations return unwilling-to-perform,
              though.  Slapd terminates when all clients have closed
              their connections (if they ever do), or - as before - if
              it receives a SIGTERM signal.  This can be useful if you
              wish to terminate the server and start a new slapd server
              with another database, without disrupting the currently
              active clients.  The default is FALSE.  You may wish to
              use olcIdleTimeout along with this option.

       olcIdleTimeout: <integer>
              Specify the number of seconds to wait before forcibly
              closing an idle client connection.  A setting of 0
              disables this feature.  The default is 0. You may also
              want to set the olcWriteTimeout option.

       olcIndexHash64: { TRUE | FALSE }
              Use a 64 bit hash for indexing. The default is to use 32
              bit hashes.  These hashes are used for equality and
              substring indexing. The 64 bit version may be needed to
              avoid index collisions when the number of indexed values
              exceeds ~64 million. (Note that substring indexing
              generates multiple index values per actual attribute
              value.)  Indices generated with 32 bit hashes are
              incompatible with the 64 bit version, and vice versa. Any
              existing databases must be fully reloaded when changing
              this setting. This directive is only supported on 64 bit

       olcIndexIntLen: <integer>
              Specify the key length for ordered integer indices. The
              most significant bytes of the binary integer will be used
              for index keys. The default value is 4, which provides
              exact indexing for 31 bit values.  A floating point
              representation is used to index too large values.

       olcIndexSubstrIfMaxlen: <integer>
              Specify the maximum length for subinitial and subfinal
              indices. Only this many characters of an attribute value
              will be processed by the indexing functions; any excess
              characters are ignored. The default is 4.

       olcIndexSubstrIfMinlen: <integer>
              Specify the minimum length for subinitial and subfinal
              indices. An attribute value must have at least this many
              characters in order to be processed by the indexing
              functions. The default is 2.

       olcIndexSubstrAnyLen: <integer>
              Specify the length used for subany indices. An attribute
              value must have at least this many characters in order to
              be processed. Attribute values longer than this length
              will be processed in segments of this length. The default
              is 4. The subany index will also be used in subinitial and
              subfinal index lookups when the filter string is longer
              than the olcIndexSubstrIfMaxlen value.

       olcIndexSubstrAnyStep: <integer>
              Specify the steps used in subany index lookups. This value
              sets the offset for the segments of a filter string that
              are processed for a subany index lookup. The default is 2.
              For example, with the default values, a search using this
              filter "cn=*abcdefgh*" would generate index lookups for
              "abcd", "cdef", and "efgh".

       Note: Indexing support depends on the particular backend in use.
       Also, changing these settings will generally require deleting any
       indices that depend on these parameters and recreating them with

       olcListenerThreads: <integer>
              Specify the number of threads to use for the connection
              manager.  The default is 1 and this is typically adequate
              for up to 16 CPU cores.  The value should be set to a
              power of 2.

       olcLocalSSF: <SSF>
              Specifies the Security Strength Factor (SSF) to be given
              local LDAP sessions, such as those to the ldapi://
              listener.  For a description of SSF values, see
              olcSaslSecProps's minssf option description.  The default
              is 71.

       olcLogFile: <filename>
              Specify a file for recording slapd debug messages. These
              messages are unrelated to messages exposed by the
              olcLogLevel configuration parameter. This setting only
              affects the slapd daemon and has no effect on the command
              line tools. By default these messages only go to stderr
              and are not recorded anywhere else.  Specifying a logfile
              copies messages to both stderr and the logfile.

       olcLogFileFormat: debug | syslog-utc | syslog-localtime
              Specify the prefix format for messages written to the
              logfile. The debug format is the normal format used for
              slapd debug messages, with a timestamp in hexadecimal,
              followed by a thread ID.  The other options are to use
              syslog(3) style prefixes, with timestamps either in UTC or
              in the local timezone. The default is debug format.

       olcLogFileOnly: TRUE | FALSE
              Specify that debug messages should only go to the
              configured logfile, and not to stderr.

       olcLogFileRotate: <max> <Mbytes> <hours>
              Specify automatic rotation for the configured logfile as
              the maximum number of old logfiles to retain, a maximum
              size in megabytes to allow a logfile to grow before
              rotation, and a maximum age in hours for a logfile to be
              used before rotation. The maximum number must be in the
              range 1-99.  Setting Mbytes or hours to zero disables the
              size or age check, respectively.  At least one of Mbytes
              or hours must be non-zero. By default no automatic
              rotation will be performed.

       olcLogLevel: <integer> [...]
              Specify the level at which debugging statements and
              operation statistics should be syslogged (currently logged
              to the syslogd(8) LOG_LOCAL4 facility).  They must be
              considered subsystems rather than increasingly verbose log
              levels.  Some messages with higher priority are logged
              regardless of the configured loglevel as soon as any
              logging is configured.  Log levels are additive, and
              available levels are:
                     1      (0x1 trace) trace function calls
                     2      (0x2 packets) debug packet handling
                     4      (0x4 args) heavy trace debugging (function
                     8      (0x8 conns) connection management
                     16     (0x10 BER) print out packets sent and
                     32     (0x20 filter) search filter processing
                     64     (0x40 config) configuration file processing
                     128    (0x80 ACL) access control list processing
                     256    (0x100 stats) connections, LDAP operations,
                            results (recommended)
                     512    (0x200 stats2) stats2 log entries sent
                     1024   (0x400 shell) print communication with shell
                     2048   (0x800 parse) entry parsing

                     16384  (0x4000 sync) LDAPSync replication
                     32768  (0x8000 none) only messages that get logged
                            whatever log level is set
              The desired log level can be input as a single integer
              that combines the (ORed) desired levels, both in decimal
              or in hexadecimal notation, as a list of integers (that
              are ORed internally), or as a list of the names that are
              shown between parenthesis, such that

                  olcLogLevel: 129
                  olcLogLevel: 0x81
                  olcLogLevel: 128 1
                  olcLogLevel: 0x80 0x1
                  olcLogLevel: acl trace

              are equivalent.  The keyword any can be used as a shortcut
              to enable logging at all levels (equivalent to -1).  The
              keyword none, or the equivalent integer representation,
              causes those messages that are logged regardless of the
              configured olcLogLevel to be logged.  In fact, if no
              olcLogLevel (or a 0 level) is defined, no logging occurs,
              so at least the none level is required to have high
              priority messages logged.

              Note that the packets, BER, and parse levels are only
              available as debug output on stderr, and are not sent to

              This setting defaults to stats.  This level should usually
              also be included when using other loglevels, to help
              analyze the logs.

       olcMaxFilterDepth: <integer>
              Specify the maximum depth of nested filters in search
              requests.  The default is 1000.

       olcPasswordCryptSaltFormat: <format>
              Specify the format of the salt passed to crypt(3) when
              generating {CRYPT} passwords (see olcPasswordHash) during
              processing of LDAP Password Modify Extended Operations
              (RFC 3062).

              This string needs to be in sprintf(3) format and may
              include one (and only one) %s conversion.  This conversion
              will be substituted with a string of random characters
              from [A-Za-z0-9./].  For example, "%.2s" provides a two
              character salt and "$1$%.8s" tells some versions of
              crypt(3) to use an MD5 algorithm and provides 8 random
              characters of salt.  The default is "%s", which provides
              31 characters of salt.

       olcPidFile: <filename>
              The (absolute) name of a file that will hold the slapd
              server's process ID (see getpid(2)).

       olcPluginLogFile: <filename>
              The ( absolute ) name of a file that will contain log
              messages from SLAPI plugins. See slapd.plugin(5) for

       olcReferral: <url>
              Specify the referral to pass back when slapd(8) cannot
              find a local database to handle a request.  If multiple
              values are specified, each url is provided.

       olcReverseLookup: TRUE | FALSE
              Enable/disable client name unverified reverse lookup
              (default is FALSE if compiled with --enable-rlookups).

       olcRootDSE: <file>
              Specify the name of an LDIF(5) file containing user
              defined attributes for the root DSE.  These attributes are
              returned in addition to the attributes normally produced
              by slapd.

              The root DSE is an entry with information about the server
              and its capabilities, in operational attributes.  It has
              the empty DN, and can be read with e.g.:
                  ldapsearch -x -b "" -s base "+"
              See RFC 4512 section 5.1 for details.

       olcSaslAuxprops: <plugin> [...]
              Specify which auxprop plugins to use for authentication
              lookups. The default is empty, which just uses slapd's
              internal support. Usually no other auxprop plugins are

       olcSaslAuxpropsDontUseCopy: <attr> [...]
              Specify which attribute(s) should be subject to the don't
              use copy control. This is necessary for some SASL
              mechanisms such as OTP to work in a replicated
              environment. The attribute "cmusaslsecretOTP" is the
              default value.

       olcSaslAuxpropsDontUseCopyIgnore TRUE | FALSE
              Used to disable replication of the attribute(s) defined by
              olcSaslAuxpropsDontUseCopy and instead use a local value
              for the attribute. This allows the SASL mechanism to
              continue to work if the provider is offline. This can
              cause replication inconsistency. Defaults to FALSE.

       olcSaslHost: <fqdn>
              Used to specify the fully qualified domain name used for
              SASL processing.

       olcSaslRealm: <realm>
              Specify SASL realm.  Default is empty.

       olcSaslCbinding: none | tls-unique | tls-endpoint
              Specify the channel-binding type, see also
              LDAP_OPT_X_SASL_CBINDING.  Default is none.

       olcSaslSecProps: <properties>
              Used to specify Cyrus SASL security properties.  The none
              flag (without any other properties) causes the flag
              properties default, "noanonymous,noplain", to be cleared.
              The noplain flag disables mechanisms susceptible to simple
              passive attacks.  The noactive flag disables mechanisms
              susceptible to active attacks.  The nodict flag disables
              mechanisms susceptible to passive dictionary attacks.  The
              noanonymous flag disables mechanisms which support
              anonymous login.  The forwardsec flag require forward
              secrecy between sessions.  The passcred require mechanisms
              which pass client credentials (and allow mechanisms which
              can pass credentials to do so).  The minssf=<factor>
              property 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.  The
              maxssf=<factor> property specifies the maximum acceptable
              security strength factor as an integer (see minssf
              description).  The default is INT_MAX.  The
              maxbufsize=<size> property specifies the maximum security
              layer receive buffer size allowed.  0 disables security
              layers.  The default is 65536.

       olcServerID: <integer> [<URL>]
              Specify an integer ID from 0 to 4095 for this server. The
              ID may also be specified as a hexadecimal ID by prefixing
              the value with "0x".  Non-zero IDs are required when using
              multi-provider replication and each provider must have a
              unique non-zero ID. Note that this requirement also
              applies to separate providers contributing to a glued set
              of databases.  If the URL is provided, this directive may
              be specified multiple times, providing a complete list of
              participating servers and their IDs. The fully qualified
              hostname of each server should be used in the supplied
              URLs. The IDs are used in the "replica id" field of all
              CSNs generated by the specified server. The default value
              is zero, which is only valid for single provider
              replication.  Example:

            olcServerID: 1 ldap://
            olcServerID: 2 ldap://

       olcSockbufMaxIncoming: <integer>
              Specify the maximum incoming LDAP PDU size for anonymous
              sessions.  The default is 262143.

       olcSockbufMaxIncomingAuth: <integer>
              Specify the maximum incoming LDAP PDU size for
              authenticated sessions.  The default is 4194303.

       olcTCPBuffer [listener=<URL>] [{read|write}=]<size>
              Specify the size of the TCP buffer.  A global value for
              both read and write TCP buffers related to any listener is
              defined, unless the listener is explicitly specified, or
              either the read or write qualifiers are used.  See tcp(7)
              for details.  Note that some OS-es implement automatic TCP
              buffer tuning.

       olcThreads: <integer>
              Specify the maximum size of the primary thread pool.  The
              default is 16; the minimum value is 2.

       olcThreadQueues: <integer>
              Specify the number of work queues to use for the primary
              thread pool.  The default is 1 and this is typically
              adequate for up to 8 CPU cores.  The value should not
              exceed the number of CPUs in the system.

       olcToolThreads: <integer>
              Specify the maximum number of threads to use in tool mode.
              This should not be greater than the number of CPUs in the
              system.  The default is 1.

       olcWriteTimeout: <integer>
              Specify the number of seconds to wait before forcibly
              closing a connection with an outstanding write.  This
              allows recovery from various network hang conditions.  A
              setting of 0 disables this feature.  The default is 0.

TLS OPTIONS         top

       If slapd is built with support for Transport Layer Security,
       there are more options you can specify.

       olcTLSCipherSuite: <cipher-suite-spec>
              Permits configuring what ciphers will be accepted and the
              preference order.  <cipher-suite-spec> should be a cipher
              specification for the TLS library in use (OpenSSL or
              GnuTLS).  This directive is not supported when using
              MbedTLS.  Example:

                            olcTLSCipherSuite: HIGH:MEDIUM:+SSLv2

                            olcTLSCiphersuite: SECURE256:!AES-128-CBC

              To check what ciphers a given spec selects in OpenSSL,

                   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

              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

       olcTLSCACertificateFile: <filename>
              Specifies the file that contains certificates for all of
              the Certificate Authorities that slapd will recognize.
              The certificate for the CA that signed the server
              certificate must be included among these certificates. If
              the signing CA was not a top-level (root) CA, certificates
              for the entire sequence of CA's from the signing CA to the
              top-level CA should be present. Multiple certificates are
              simply appended to the file; the order is not significant.

       olcTLSCACertificatePath: <path>
              Specifies the path of directories that contain Certificate
              Authority certificates in separate individual files.
              Usually only one of this or the olcTLSCACertificateFile is
              defined. If both are specified, both locations will be
              used. Multiple directories may be specified, separated by
              a semi-colon.

       olcTLSCertificateFile: <filename>
              Specifies the file that contains the slapd server

              When using OpenSSL that file may also contain any number
              of intermediate certificates after the server certificate.

       olcTLSCertificateKeyFile: <filename>
              Specifies the file that contains the slapd server private
              key that matches the certificate stored in the
              olcTLSCertificateFile file. If the private key is
              protected with a password, the password must be manually
              typed in when slapd starts.  Usually the private key is
              not protected with a password, to allow slapd to start
              without manual intervention, so it is of critical
              importance that the file is protected carefully.

       olcTLSDHParamFile: <filename>
              This directive specifies the file that contains parameters
              for Diffie-Hellman ephemeral key exchange.  This is
              required in order to use a DSA certificate on the server,
              or an RSA certificate missing the "key encipherment" key
              usage.  Note that setting this option may also enable
              Anonymous Diffie-Hellman key exchanges in certain non-
              default cipher suites.  Anonymous key exchanges should
              generally be avoided since they provide no actual client
              or server authentication and provide no protection against
              man-in-the-middle attacks.  You should append "!ADH" to
              your cipher suites to ensure that these suites are not
              used.  This directive is not supported when using MbedTLS.

       olcTLSECName: <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

       olcTLSProtocolMin: <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.,

                   olcTLSProtocolMin: 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 directive is ignored with GnuTLS.

       olcTLSRandFile: <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
              directive is ignored with GnuTLS.

       olcTLSVerifyClient: <level>
              Specifies what checks to perform on client certificates in
              an incoming TLS session, if any.  The <level> can be
              specified as one of the following keywords:

              never  This is the default.  slapd will not ask the client
                     for a certificate.

              allow  The client 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 client 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 | true
                     These keywords are all equivalent, for
                     compatibility reasons.  The client certificate is
                     requested.  If no certificate is provided, or a bad
                     certificate is provided, the session is immediately

                     Note that a valid client certificate is required in
                     order to use the SASL EXTERNAL authentication
                     mechanism with a TLS session.  As such, a non-
                     default olcTLSVerifyClient setting must be chosen
                     to enable SASL EXTERNAL authentication.

       olcTLSCRLCheck: <level>
              Specifies if the Certificate Revocation List (CRL) of the
              CA should be used to verify if the client certificates
              have not been revoked. This requires
              olcTLSCACertificatePath 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

       olcTLSCRLFile: <filename>
              Specifies a file containing a Certificate Revocation List
              to be used for verifying that certificates have not been
              revoked. This parameter is only valid when using GnuTLS.


       If slapd is compiled with --enable-modules then the module-
       related entries will be available. These entries are named
       cn=module{x},cn=config and must have the olcModuleList
       objectClass. One entry should be created per olcModulePath.
       Normally the config engine generates the "{x}" index in the RDN
       automatically, so it can be omitted when initially loading these

       olcModuleLoad: <filename> [<arguments>...]
              Specify the name of a dynamically loadable module to load
              and any additional arguments if supported by the module.
              The filename may be an absolute path name or a simple
              filename. Non-absolute names are searched for in the
              directories specified by the olcModulePath option.

       olcModulePath: <pathspec>
              Specify a list of directories to search for loadable
              modules. Typically the path is colon-separated but this
              depends on the operating system.  The default is
              MODULEDIR, which is where the standard OpenLDAP install
              will place its modules.

SCHEMA OPTIONS         top

       Schema definitions are created as entries in the
       cn=schema,cn=config subtree. These entries must have the
       olcSchemaConfig objectClass.  As noted above, the actual
       cn=schema,cn=config entry is predefined and any values specified
       for it are ignored.

       olcAttributetypes: ( <oid> [NAME <name>] [DESC <description>]
              [OBSOLETE] [SUP <oid>] [EQUALITY <oid>] [ORDERING <oid>]
              [SUBSTR <oid>] [SYNTAX <oidlen>] [SINGLE-VALUE]
              [USAGE <attributeUsage>] )
              Specify an attribute type using the LDAPv3 syntax defined
              in RFC 4512.  The slapd parser extends the RFC 4512
              definition by allowing string forms as well as numeric
              OIDs to be used for the attribute OID and attribute syntax
              OID.  (See the olcObjectIdentifier description.)

       olcDitContentRules: ( <oid> [NAME <name>] [DESC <description>]
              [OBSOLETE] [AUX <oids>] [MUST <oids>] [MAY <oids>]
              [NOT <oids>] )
              Specify an DIT Content Rule using the LDAPv3 syntax
              defined in RFC 4512.  The slapd parser extends the RFC
              4512 definition by allowing string forms as well as
              numeric OIDs to be used for the attribute OID and
              attribute syntax OID.  (See the olcObjectIdentifier

       olcLdapSyntaxes ( <oid> [DESC <description>] [X-SUBST
              <substitute-syntax>] )
              Specify an LDAP syntax using the LDAPv3 syntax defined in
              RFC 4512.  The slapd parser extends the RFC 4512
              definition by allowing string forms as well as numeric
              OIDs to be used for the syntax OID.  (See the
              objectidentifier description.)  The slapd parser also
              honors the X-SUBST extension (an OpenLDAP-specific
              extension), which allows one to use the olcLdapSyntaxes
              attribute to define a non-implemented syntax along with
              another syntax, the extension value substitute-syntax, as
              its temporary replacement.  The substitute-syntax must be
              defined.  This allows one to define attribute types that
              make use of non-implemented syntaxes using the correct
              syntax OID.  Unless X-SUBST is used, this configuration
              statement would result in an error, since no handlers
              would be associated to the resulting syntax structure.

       olcObjectClasses: ( <oid> [NAME <name>] [DESC <description>]
              [OBSOLETE] [SUP <oids>] [{ ABSTRACT | STRUCTURAL |
              AUXILIARY }] [MUST <oids>] [MAY <oids>] )
              Specify an objectclass using the LDAPv3 syntax defined in
              RFC 4512.  The slapd parser extends the RFC 4512
              definition by allowing string forms as well as numeric
              OIDs to be used for the object class OID.  (See the
              olcObjectIdentifier description.)  Object classes are
              "STRUCTURAL" by default.

       olcObjectIdentifier: <name> { <oid> | <name>[:<suffix>] }
              Define a string name that equates to the given OID. The
              string can be used in place of the numeric OID in
              objectclass and attribute definitions. The name can also
              be used with a suffix of the form ":xx" in which case the
              value "oid.xx" will be used.


       Options in these entries only apply to the configuration of a
       single type of backend. All backends may support this class of
       options, but currently only back-mdb does.  The entry must be
       named olcBackend=<databasetype>,cn=config and must have the
       olcBackendConfig objectClass.  <databasetype> should be one of
       asyncmeta, config, dnssrv, ldap, ldif, mdb, meta, monitor, null,
       passwd, perl, relay, sock, sql, or wt.  At present, only back-mdb
       implements any options of this type, so this entry should not be
       used for any other backends.


       Database options are set in entries named
       olcDatabase={x}<databasetype>,cn=config and must have the
       olcDatabaseConfig objectClass. Normally the config engine
       generates the "{x}" index in the RDN automatically, so it can be
       omitted when initially loading these entries.

       The special frontend database is always numbered "{-1}" and the
       config database is always numbered "{0}".


       Options in this section may be set in the special "frontend"
       database and inherited in all the other databases. These options
       may be altered by further settings in each specific database. The
       frontend entry must be named olcDatabase=frontend,cn=config and
       must have the olcFrontendConfig objectClass.

       olcAccess: to <what> [ by <who> <access> <control> ]+
              Grant access (specified by <access>) to a set of entries
              and/or attributes (specified by <what>) by one or more
              requestors (specified by <who>).  If no access controls
              are present, the default policy allows anyone and everyone
              to read anything but restricts updates to rootdn.  (e.g.,
              "olcAccess: to * by * read").  See slapd.access(5) and the
              "OpenLDAP Administrator's Guide" for details.

              Access controls set in the frontend are appended to any
              access controls set on the specific databases.  The rootdn
              of a database can always read and write EVERYTHING in that

              Extra special care must be taken with the access controls
              on the config database. Unlike other databases, the
              default policy for the config database is to only allow
              access to the rootdn. Regular users should not have read
              access, and write access should be granted very carefully
              to privileged administrators.

       olcDefaultSearchBase: <dn>
              Specify a default search base to use when client submits a
              non-base search request with an empty base DN.  Base
              scoped search requests with an empty base DN are not
              affected.  This setting is only allowed in the frontend

       olcExtraAttrs: <attr>
              Lists what attributes need to be added to search requests.
              Local storage backends return the entire entry to the
              frontend.  The frontend takes care of only returning the
              requested attributes that are allowed by ACLs.  However,
              features like access checking and so may need specific
              attributes that are not automatically returned by remote
              storage backends, like proxy backends and so on.  <attr>
              is an attribute that is needed for internal purposes and
              thus always needs to be collected, even when not
              explicitly requested by clients.  This attribute is multi-

       olcPasswordHash: <hash> [<hash>...]
              This option configures one or more hashes to be used in
              generation of user passwords stored in the userPassword
              attribute during processing of LDAP Password Modify
              Extended Operations (RFC 3062).  The <hash> must be one of
              {SSHA}, {SHA}, {SMD5}, {MD5}, {CRYPT}, and {CLEARTEXT}.
              The default is {SSHA}.

              {SHA} and {SSHA} use the SHA-1 algorithm (FIPS 160-1), the
              latter with a seed.

              {MD5} and {SMD5} use the MD5 algorithm (RFC 1321), the
              latter with a seed.

              {CRYPT} uses the crypt(3).

              {CLEARTEXT} indicates that the new password should be
              added to userPassword as clear text.

              Note that this option does not alter the normal user
              applications handling of userPassword during LDAP Add,
              Modify, or other LDAP operations.  This setting is only
              allowed in the frontend entry.

       olcReadOnly: TRUE | FALSE
              This option puts the database into "read-only" mode.  Any
              attempts to modify the database will return an "unwilling
              to perform" error.  By default, olcReadOnly is FALSE. Note
              that when this option is set TRUE on the frontend, it
              cannot be reset without restarting the server, since
              further writes to the config database will be rejected.

       olcRequires: <conditions>
              Specify a set of conditions to require (default none).
              The directive may be specified globally and/or per-
              database; databases inherit global conditions, so per-
              database specifications are additive.  bind requires bind
              operation prior to directory operations.  LDAPv3 requires
              session to be using LDAP version 3.  authc requires
              authentication prior to directory operations.  SASL
              requires SASL authentication prior to directory
              operations.  strong requires strong authentication prior
              to directory operations.  The strong keyword allows
              protected "simple" authentication as well as SASL
              authentication.  none may be used to require no conditions
              (useful to clear out globally set conditions within a
              particular database); it must occur first in the list of

       olcRestrict: <oplist>
              Specify a list of operations that are restricted.
              Restrictions on a specific database override any frontend
              setting.  Operations can be any of add, bind, compare,
              delete, extended[=<OID>], modify, rename, search, or the
              special pseudo-operations read and write, which
              respectively summarize read and write operations.  The use
              of restrict write is equivalent to olcReadOnly: TRUE (see
              above).  The extended keyword allows one to indicate the
              OID of the specific operation to be restricted.

       olcSchemaDN: <dn>
              Specify the distinguished name for the subschema subentry
              that controls the entries on this server.  The default is

       olcSecurity: <factors>
              Specify a set of security strength factors (separated by
              white space) to require (see olcSaslSecprops's minssf
              option for a description of security strength factors).
              The directive may be specified globally and/or per-
              database.  ssf=<n> specifies the overall security strength
              factor.  transport=<n> specifies the transport security
              strength factor.  tls=<n> specifies the TLS security
              strength factor.  sasl=<n> specifies the SASL security
              strength factor.  update_ssf=<n> specifies the overall
              security strength factor to require for directory updates.
              update_transport=<n> specifies the transport security
              strength factor to require for directory updates.
              update_tls=<n> specifies the TLS security strength factor
              to require for directory updates.  update_sasl=<n>
              specifies the SASL security strength factor to require for
              directory updates.  simple_bind=<n> specifies the security
              strength factor required for simple username/password
              authentication.  Note that the transport factor is measure
              of security provided by the underlying transport, e.g.
              ldapi:// (and eventually IPSEC).  It is not normally used.

       olcSizeLimit: {<integer>|unlimited}

       olcSizeLimit: size[.{soft|hard}]=<integer> [...]
              Specify the maximum number of entries to return from a
              search operation.  The default size limit is 500.  Use
              unlimited to specify no limits.  The second format allows
              a fine grain setting of the size limits.  If no special
              qualifiers are specified, both soft and hard limits are
              set.  Extra args can be added in the same value.
              Additional qualifiers are available; see olcLimits for an
              explanation of all of the different flags.

       olcSortVals: <attr> [...]
              Specify a list of multi-valued attributes whose values
              will always be maintained in sorted order. Using this
              option will allow Modify, Compare, and filter evaluations
              on these attributes to be performed more efficiently. The
              resulting sort order depends on the attributes' syntax and
              matching rules and may not correspond to lexical order or
              any other recognizable order.  This setting is only
              allowed in the frontend entry.

       olcTimeLimit: {<integer>|unlimited}

       olcTimeLimit: time[.{soft|hard}]=<integer> [...]
              Specify the maximum number of seconds (in real time) slapd
              will spend answering a search request.  The default time
              limit is 3600.  Use unlimited to specify no limits.  The
              second format allows a fine grain setting of the time
              limits.  Extra args can be added in the same value. See
              olcLimits for an explanation of the different flags.


       Options in this section only apply to the specific database for
       which they are defined.  They are supported by every type of
       backend. All of the Global Database Options may also be used

       olcAddContentAcl: TRUE | FALSE
              Controls whether Add operations will perform ACL checks on
              the content of the entry being added. This check is off by
              default. See the slapd.access(5) manual page for more
              details on ACL requirements for Add operations.

       olcHidden: TRUE | FALSE
              Controls whether the database will be used to answer
              queries. A database that is hidden will never be selected
              to answer any queries, and any suffix configured on the
              database will be ignored in checks for conflicts with
              other databases. By default, olcHidden is FALSE.

       olcLastMod: TRUE | FALSE
              Controls whether slapd will automatically maintain the
              modifiersName, modifyTimestamp, creatorsName, and
              createTimestamp attributes for entries. It also controls
              the entryCSN and entryUUID attributes, which are needed by
              the syncrepl provider. By default, olcLastMod is TRUE.

       olcLastBind: TRUE | FALSE
              Controls whether slapd will automatically maintain the
              pwdLastSuccess attribute for entries. By default,
              olcLastBind is FALSE.

       olcLastBindPrecision: <integer>
              If olcLastBind is enabled, specifies how frequently
              pwdLastSuccess will be updated. More than integer seconds
              must have passed since the last successful bind. In a
              replicated environment with frequent bind activity it may
              be useful to set this to a large value. On a backend, if
              set to 0 (the default), the value set on the frontend is

       olcLimits: <selector> <limit> [<limit> [...]]
              Specify time and size limits based on the operation's
              initiator or base DN.  The argument <selector> can be any

                     anonymous | users | [<dnspec>=]<pattern> |


                     <dnspec> ::= dn[.<type>][.<style>]

                     <type>  ::= self | this

                     <style> ::= exact | base | onelevel | subtree |
                     children | regex | anonymous

              DN type self is the default and means the bound user,
              while this means the base DN of the operation.  The term
              anonymous matches all unauthenticated clients.  The term
              users matches all authenticated clients; otherwise an
              exact dn pattern is assumed unless otherwise specified by
              qualifying the (optional) key string dn with exact or base
              (which are synonyms), to require an exact match; with
              onelevel, to require exactly one level of depth match;
              with subtree, to allow any level of depth match, including
              the exact match; with children, to allow any level of
              depth match, not including the exact match; regex
              explicitly requires the (default) match based on POSIX
              (''extended'') regular expression pattern.  Finally,
              anonymous matches unbound operations; the pattern field is
              ignored.  The same behavior is obtained by using the
              anonymous form of the <selector> clause.  The term group,
              with the optional objectClass oc and attributeType at
              fields, followed by pattern, sets the limits for any DN
              listed in the values of the at attribute (default member)
              of the oc group objectClass (default groupOfNames) whose
              DN exactly matches pattern.

              The currently supported limits are size and time.

              The syntax for time limits is
              time[.{soft|hard}]=<integer>, where integer is the number
              of seconds slapd will spend answering a search request.
              If no time limit is explicitly requested by the client,
              the soft limit is used; if the requested time limit
              exceeds the hard limit, the value of the limit is used
              instead.  If the hard limit is set to the keyword soft,
              the soft limit is used in either case; if it is set to the
              keyword unlimited, no hard limit is enforced.  Explicit
              requests for time limits smaller or equal to the hard
              limit are honored.  If no limit specifier is set, the
              value is assigned to the soft limit, and the hard limit is
              set to soft, to preserve the original behavior.

              The syntax for size limits is
              size[.{soft|hard|unchecked}]=<integer>, where integer is
              the maximum number of entries slapd will return answering
              a search request.  If no size limit is explicitly
              requested by the client, the soft limit is used; if the
              requested size limit exceeds the hard limit, the value of
              the limit is used instead.  If the hard limit is set to
              the keyword soft, the soft limit is used in either case;
              if it is set to the keyword unlimited, no hard limit is
              enforced.  Explicit requests for size limits smaller or
              equal to the hard limit are honored.  The unchecked
              specifier sets a limit on the number of candidates a
              search request is allowed to examine.  The rationale
              behind it is that searches for non-properly indexed
              attributes may result in large sets of candidates, which
              must be examined by slapd(8) to determine whether they
              match the search filter or not.  The unchecked limit
              provides a means to drop such operations before they are
              even started.  If the selected candidates exceed the
              unchecked limit, the search will abort with Unwilling to
              perform.  If it is set to the keyword unlimited, no limit
              is applied (the default).  If it is set to disabled, the
              search is not even performed; this can be used to disallow
              searches for a specific set of users.  If no limit
              specifier is set, the value is assigned to the soft limit,
              and the hard limit is set to soft, to preserve the
              original behavior.

              In case of no match, the global limits are used.  The
              default values are the same as for olcSizeLimit and
              olcTimeLimit; no limit is set on unchecked.

              If pagedResults control is requested, the hard size limit
              is used by default, because the request of a specific page
              size is considered an explicit request for a limitation on
              the number of entries to be returned.  However, the size
              limit applies to the total count of entries returned
              within the search, and not to a single page.  Additional
              size limits may be enforced; the syntax is
    {<integer>|noEstimate|unlimited}, where integer is
              the max page size if no explicit limit is set; the keyword
              noEstimate inhibits the server from returning an estimate
              of the total number of entries that might be returned
              (note: the current implementation does not return any
              estimate).  The keyword unlimited indicates that no limit
              is applied to the pagedResults control page size.  The
              syntax size.prtotal={<integer>|hard|unlimited|disabled}
              allows one to set a limit on the total number of entries
              that the pagedResults control will return.  By default it
              is set to the hard limit which will use the size.hard
              value.  When set, integer is the max number of entries
              that the whole search with pagedResults control can
              return.  Use unlimited to allow unlimited number of
              entries to be returned, e.g. to allow the use of the
              pagedResults control as a means to circumvent size
              limitations on regular searches; the keyword disabled
              disables the control, i.e. no paged results can be
              returned.  Note that the total number of entries returned
              when the pagedResults control is requested cannot exceed
              the hard size limit of regular searches unless extended by
              the prtotal switch.

              The olcLimits statement is typically used to let an
              unlimited number of entries be returned by searches
              performed with the identity used by the consumer for
              synchronization purposes by means of the RFC 4533 LDAP
              Content Synchronization protocol (see olcSyncrepl for

              When using subordinate databases, it is necessary for any
              limits that are to be applied across the parent and its
              subordinates to be defined in both the parent and its
              subordinates. Otherwise the settings on the subordinate
              databases are not honored.

       olcMaxDerefDepth: <depth>
              Specifies the maximum number of aliases to dereference
              when trying to resolve an entry, used to avoid infinite
              alias loops. The default is 15.

       olcMultiProvider: TRUE | FALSE
              This option puts a consumer database into Multi-Provider
              mode.  Update operations will be accepted from any user,
              not just the updatedn.  The database must already be
              configured as a syncrepl consumer before this keyword may
              be set. This mode also requires a olcServerID (see above)
              to be configured.  By default, this setting is FALSE.

       olcMonitoring: TRUE | FALSE
              This option enables database-specific monitoring in the
              entry related to the current database in the
              "cn=Databases,cn=Monitor" subtree of the monitor database,
              if the monitor database is enabled.  Currently, only the
              MDB database provides database-specific monitoring.  If
              monitoring is supported by the backend it defaults to
              TRUE, otherwise FALSE.

       olcPlugin: <plugin_type> <lib_path> <init_function> [<arguments>]
              Configure a SLAPI plugin. See the slapd.plugin(5) manpage
              for more details.

       olcRootDN: <dn>
              Specify the distinguished name that is not subject to
              access control or administrative limit restrictions for
              operations on this database.  This DN may or may not be
              associated with an entry.  An empty root DN (the default)
              specifies no root access is to be granted.  It is
              recommended that the rootdn only be specified when needed
              (such as when initially populating a database).  If the
              rootdn is within a namingContext (suffix) of the database,
              a simple bind password may also be provided using the
              olcRootPW directive. Many optional features, including
              syncrepl, require the rootdn to be defined for the
              database.  The olcRootDN of the cn=config database
              defaults to cn=config itself.

       olcRootPW: <password>
              Specify a password (or hash of the password) for the
              rootdn.  The password can only be set if the rootdn is
              within the namingContext (suffix) of the database.  This
              option accepts all RFC 2307 userPassword formats known to
              the server (see olcPasswordHash description) as well as
              cleartext.  slappasswd(8) may be used to generate a hash
              of a password.  Cleartext and {CRYPT} passwords are not
              recommended.  If empty (the default), authentication of
              the root DN is by other means (e.g. SASL).  Use of SASL is

       olcSubordinate: [TRUE | FALSE | advertise]
              Specify that the current backend database is a subordinate
              of another backend database. A subordinate  database may
              have only one suffix. This option may be used to glue
              multiple databases into a single namingContext.  If the
              suffix of the current database is within the namingContext
              of a superior database, searches against the superior
              database will be propagated to the subordinate as well.
              All of the databases associated with a single
              namingContext should have identical rootdns.  Behavior of
              other LDAP operations is unaffected by this setting. In
              particular, it is not possible to use moddn to move an
              entry from one subordinate to another subordinate within
              the namingContext.

              If the optional advertise flag is supplied, the naming
              context of this database is advertised in the root DSE.
              The default is to hide this database context, so that only
              the superior context is visible.

              If the slap tools slapcat(8), slapadd(8), slapmodify(8),
              or slapindex(8) are used on the superior database, any
              glued subordinates that support these tools are opened as

              Databases that are glued together should usually be
              configured with the same indices (assuming they support
              indexing), even for attributes that only exist in some of
              these databases. In general, all of the glued databases
              should be configured as similarly as possible, since the
              intent is to provide the appearance of a single directory.

              Note that the subordinate functionality is implemented
              internally by the glue overlay and as such its behavior
              will interact with other overlays in use. By default, the
              glue overlay is automatically configured as the last
              overlay on the superior database. Its position on the
              database can be explicitly configured by setting an
              overlay glue directive at the desired position. This
              explicit configuration is necessary e.g.  when using the
              syncprov overlay, which needs to follow glue in order to
              work over all of the glued databases. E.g.
                   dn: olcDatabase={1}mdb,cn=config
                   olcSuffix: dc=example,dc=com

                   dn: olcOverlay={0}glue,olcDatabase={1}mdb,cn=config

                   dn: olcOverlay={1}syncprov,olcDatabase={1}mdb,cn=config
       See the Overlays section below for more details.

       olcSuffix: <dn suffix>
              Specify the DN suffix of queries that will be passed to
              this backend database.  Multiple suffix lines can be given
              and at least one is required for each database definition.

              If the suffix of one database is "inside" that of another,
              the database with the inner suffix must come first in the
              configuration file.  You may also want to glue such
              databases together with the olcSubordinate attribute.

       olcSyncUseSubentry: TRUE | FALSE
              Store the syncrepl contextCSN in a subentry instead of the
              context entry of the database. The subentry's RDN will be
              "cn=ldapsync". The default is FALSE, meaning the
              contextCSN is stored in the context entry.

       olcSyncrepl: rid=<replica ID>
              provider=ldap[s]://<hostname>[:port] searchbase=<base DN>
              [interval=dd:hh:mm:ss] [retry=[<retry interval> <# of
              retries>]+] [filter=<filter str>]
              [scope=sub|one|base|subord] [attrs=<attr list>]
              [exattrs=<attr list>] [attrsonly] [sizelimit=<limit>]
              [timelimit=<limit>] [schemachecking=on|off]
              [network-timeout=<seconds>] [timeout=<seconds>]
              [tcp-user-timeout=<milliseconds>] [bindmethod=simple|sasl]
              [binddn=<dn>] [saslmech=<mech>] [authcid=<identity>]
              [authzid=<identity>] [credentials=<passwd>]
              [realm=<realm>] [secprops=<properties>]
              [starttls=yes|critical] [tls_cert=<file>] [tls_key=<file>]
              [tls_cacert=<file>] [tls_cacertdir=<path>]
              [tls_cipher_suite=<ciphers>] [tls_ecname=<names>]
              [tls_protocol_min=<major>[.<minor>]] [suffixmassage=<real
              DN>] [logbase=<base DN>] [logfilter=<filter str>]
              [syncdata=default|accesslog|changelog] [lazycommit]
              Specify the current database as a consumer which is kept
              up-to-date with the provider content by establishing the
              current slapd(8) as a replication consumer site running a
              syncrepl replication engine.  The consumer content is kept
              synchronized to the provider content using the LDAP
              Content Synchronization protocol. Refer to the "OpenLDAP
              Administrator's Guide" for detailed information on setting
              up a replicated slapd directory service using the syncrepl
              replication engine.

              rid identifies the current syncrepl directive within the
              replication consumer site.  It is a non-negative integer
              not greater than 999 (limited to three decimal digits).

              provider specifies the replication provider site
              containing the provider content as an LDAP URI. If <port>
              is not given, the standard LDAP port number (389 or 636)
              is used.

              The content of the syncrepl consumer is defined using a
              search specification as its result set. The consumer slapd
              will send search requests to the provider slapd according
              to the search specification. The search specification
              includes searchbase, scope, filter, attrs, attrsonly,
              sizelimit, and timelimit parameters as in the normal
              search specification. The exattrs option may also be used
              to specify attributes that should be omitted from incoming
              entries.  The scope defaults to sub, the filter defaults
              to (objectclass=*), and there is no default searchbase.
              The attrs list defaults to "*,+" to return all user and
              operational attributes, and attrsonly and exattrs are
              unset by default.  The sizelimit and timelimit only accept
              "unlimited" and positive integers, and both default to
              "unlimited".  The sizelimit and timelimit parameters
              define a consumer requested limitation on the number of
              entries that can be returned by the LDAP Content
              Synchronization operation; these should be left unchanged
              from the default otherwise replication may never succeed.
              Note, however, that any provider-side limits for the
              replication identity will be enforced by the provider
              regardless of the limits requested by the LDAP Content
              Synchronization operation, much like for any other search

              The LDAP Content Synchronization protocol has two
              operation types.  In the refreshOnly operation, the next
              synchronization search operation is periodically
              rescheduled at an interval time (specified by interval
              parameter; 1 day by default) after each synchronization
              operation finishes.  In the refreshAndPersist operation, a
              synchronization search remains persistent in the provider
              slapd.  Further updates to the provider will generate
              searchResultEntry to the consumer slapd as the search
              responses to the persistent synchronization search. If the
              initial search fails due to an error, the next
              synchronization search operation is periodically
              rescheduled at an interval time (specified by interval
              parameter; 1 day by default)

              If an error occurs during replication, the consumer will
              attempt to reconnect according to the retry parameter
              which is a list of the <retry interval> and <# of retries>
              pairs.  For example, retry="60 10 300 3" lets the consumer
              retry every 60 seconds for the first 10 times and then
              retry every 300 seconds for the next 3 times before stop
              retrying. The `+' in <# of retries> means indefinite
              number of retries until success.  If no retry is
              specified, by default syncrepl retries every hour forever.

              The schema checking can be enforced at the LDAP Sync
              consumer site by turning on the schemachecking parameter.
              The default is off.  Schema checking on means that
              replicated entries must have a structural objectClass,
              must obey to objectClass requirements in terms of
              required/allowed attributes, and that naming attributes
              and distinguished values must be present.  As a
              consequence, schema checking should be off when partial
              replication is used.

              The network-timeout parameter sets how long the consumer
              will wait to establish a network connection to the
              provider. Once a connection is established, the timeout
              parameter determines how long the consumer will wait for
              the initial Bind request to complete. The defaults for
              these parameters come from ldap.conf(5).  The
              tcp-user-timeout parameter, if non-zero, corresponds to
              the TCP_USER_TIMEOUT set on the target connections,
              overriding the operating system setting.  Only some
              systems support the customization of this parameter, it is
              ignored otherwise and system-wide settings are used.

              A bindmethod of simple requires the options binddn and
              credentials and should only be used when adequate security
              services (e.g. TLS or IPSEC) are in place.  REMEMBER:
              simple bind credentials must be in cleartext!  A
              bindmethod of sasl requires the option saslmech.
              Depending on the mechanism, an authentication identity
              and/or credentials can be specified using authcid and
              credentials.  The authzid parameter may be used to specify
              an authorization identity.  Specific security properties
              (as with the sasl-secprops keyword above) for a SASL bind
              can be set with the secprops option. A non default SASL
              realm can be set with the realm option.  The identity used
              for synchronization by the consumer should be allowed to
              receive an unlimited number of entries in response to a
              search request.  The provider, other than allowing
              authentication of the syncrepl identity, should grant that
              identity appropriate access privileges to the data that is
              being replicated (access directive), and appropriate time
              and size limits.  This can be accomplished by either
              allowing unlimited sizelimit and timelimit, or by setting
              an appropriate limits statement in the consumer's
              configuration (see sizelimit and limits for details).

              The keepalive parameter sets the values of idle, probes,
              and interval used to check whether a socket is alive; idle
              is the number of seconds a connection needs to remain idle
              before TCP starts sending keepalive probes; probes is the
              maximum number of keepalive probes TCP should send before
              dropping the connection; interval is interval in seconds
              between individual keepalive probes.  Only some systems
              support the customization of these values; the keepalive
              parameter is ignored otherwise, and system-wide settings
              are used.

              The starttls parameter specifies use of the StartTLS
              extended operation to establish a TLS session before
              Binding to the provider. If the critical argument is
              supplied, the session will be aborted if the StartTLS
              request fails. Otherwise the syncrepl session continues
              without TLS. The tls_reqcert setting defaults to "demand",
              the tls_reqsan setting defaults to "allow", and the other
              TLS settings default to the same as the main slapd TLS

              The suffixmassage parameter allows the consumer to pull
              entries from a remote directory whose DN suffix differs
              from the local directory. The portion of the remote
              entries' DNs that matches the searchbase will be replaced
              with the suffixmassage DN.

              Rather than replicating whole entries, the consumer can
              query logs of data modifications. This mode of operation
              is referred to as delta syncrepl. In addition to the above
              parameters, the logbase and logfilter parameters must be
              set appropriately for the log that will be used. The
              syncdata parameter must be set to either "accesslog" if
              the log conforms to the slapo-accesslog(5) log format, or
              "changelog" if the log conforms to the obsolete changelog
              format. If the syncdata parameter is omitted or set to
              "default" then the log parameters are ignored.

              The lazycommit parameter tells the underlying database
              that it can store changes without performing a full flush
              after each change. This may improve performance for the
              consumer, while sacrificing safety or durability.

       olcUpdateDN: <dn>
              This option is only applicable in a replica database.  It
              specifies the DN permitted to update (subject to access
              controls) the replica.  It is only needed in certain push-
              mode replication scenarios.  Generally, this DN should not
              be the same as the rootdn used at the provider.

       olcUpdateRef: <url>
              Specify the referral to pass back when slapd(8) is asked
              to modify a replicated local database.  If multiple values
              are specified, each url is provided.


       Each database may allow specific configuration options; they are
       documented separately in the backends' manual pages. See the
       slapd.backends(5) manual page for an overview of available

OVERLAYS         top

       An overlay is a piece of code that intercepts database operations
       in order to extend or change them. Overlays are pushed onto a
       stack over the database, and so they will execute in the reverse
       of the order in which they were configured and the database
       itself will receive control last of all.

       Overlays must be configured as child entries of a specific
       database. The entry's RDN must be of the form
       olcOverlay={x}<overlaytype> and the entry must have the
       olcOverlayConfig objectClass. Normally the config engine
       generates the "{x}" index in the RDN automatically, so it can be
       omitted when initially loading these entries.

       See the slapd.overlays(5) manual page for an overview of
       available overlays.

EXAMPLES         top

       Here is a short example of a configuration in LDIF suitable for
       use with slapadd(8) :

              dn: cn=config
              objectClass: olcGlobal
              cn: config
              olcPidFile: LOCALSTATEDIR/run/
              olcAttributeOptions: x-hidden lang-

              dn: cn=schema,cn=config
              objectClass: olcSchemaConfig
              cn: schema

              include: file://SYSCONFDIR/schema/core.ldif

              dn: olcDatabase=frontend,cn=config
              objectClass: olcDatabaseConfig
              objectClass: olcFrontendConfig
              olcDatabase: frontend
              # Subtypes of "name" (e.g. "cn" and "ou") with the
              # option ";x-hidden" can be searched for/compared,
              # but are not shown.  See slapd.access(5).
              olcAccess: to attrs=name;x-hidden by * =cs
              # Protect passwords.  See slapd.access(5).
              olcAccess: to attrs=userPassword  by * auth
              # Read access to other attributes and entries.
              olcAccess: to * by * read

              # set a rootpw for the config database so we can bind.
              # deny access to everyone else.
              dn: olcDatabase=config,cn=config
              objectClass: olcDatabaseConfig
              olcDatabase: config
              olcRootPW: {SSHA}XKYnrjvGT3wZFQrDD5040US592LxsdLy
              olcAccess: to * by * none

              dn: olcDatabase=mdb,cn=config
              objectClass: olcDatabaseConfig
              objectClass: olcMdbConfig
              olcDatabase: mdb
              olcSuffix: "dc=our-domain,dc=com"
              # The database directory MUST exist prior to
              # running slapd AND should only be accessible
              # by the slapd/tools. Mode 0700 recommended.
              olcDbDirectory: LOCALSTATEDIR/openldap-data
              # Indices to maintain
              olcDbIndex:     objectClass  eq
              olcDbIndex:     cn,sn,mail   pres,eq,approx,sub

              # We serve small clients that do not handle referrals,
              # so handle remote lookups on their behalf.
              dn: olcDatabase=ldap,cn=config
              objectClass: olcDatabaseConfig
              objectClass: olcLdapConfig
              olcDatabase: ldap
              olcSuffix: ""
              olcDbUri: ldap://

       Assuming the above data was saved in a file named "config.ldif"
       and the ETCDIR/slapd.d directory has been created, this command
       will initialize the configuration:
              slapadd -F ETCDIR/slapd.d -n 0 -l config.ldif

       "OpenLDAP Administrator's Guide" contains a longer annotated
       example of a slapd configuration.

       Alternatively, an existing slapd.conf file can be converted to
       the new format using slapd or any of the slap tools:
              slaptest -f ETCDIR/slapd.conf -F ETCDIR/slapd.d

FILES         top

              default slapd configuration file

              default slapd configuration directory

SEE ALSO         top

       ldap(3), ldif(5), gnutls-cli(1), slapd.access(5),
       slapd.backends(5), slapd.conf(5), slapd.overlays(5),
       slapd.plugin(5), slapd(8), slapacl(8), slapadd(8), slapauth(8),
       slapcat(8), slapdn(8), slapindex(8), slapmodify(8),
       slappasswd(8), slaptest(8).

       "OpenLDAP Administrator's Guide"


       OpenLDAP Software is developed and maintained by The OpenLDAP
       Project <>.  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 
       ⟨⟩.  If you have a bug report for this
       manual page, see ⟨⟩.  This page was
       obtained from the project's upstream Git repository
       ⟨⟩ on 2024-06-14.
       (At that time, the date of the most recent commit that was found
       in the repository was 2024-06-13.)  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 improvements to the information in this COLOPHON
       (which is not part of the original manual page), send a mail to

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