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),
and
slaptest(8).
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 settings:
cn=Module
dynamically loaded modules
cn=Schema
schema definitions
olcBackend=xxx
backend-specific settings
olcDatabase=xxx
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 there are no backends that implement settings of this
nature, so usually there will not be any olcBackend entries.
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.
GLOBAL CONFIGURATION OPTIONS
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 forms:
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, consisting of the keyword
group,
optionally followed by the specification of the group
objectClass
and member
attributeType.
The group with DN
<pattern>
is searched with base scope, and in case of match, the values of the
member
attributeType
are searched for the asserted DN.
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
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, to an LDAP DN used for
authorization purposes. Note that the resultant 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 form
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.
UID=([^,]*),CN=.*
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.
UID=$1,OU=Accounts,DC=example,DC=com
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).
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.
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
slapindex(8).
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 debug log messages. 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.
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:
(0x400 shell)
print communication with shell backends
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 brackets, such that
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.
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 details.
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 needed.
olcSaslHost: <fqdn>
Used to specify the fully qualified domain name used for SASL processing.
olcSaslRealm: <realm>
Specify SASL realm. Default is empty.
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, 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.
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 (limited
to 3 hexadecimal digits). The ID may also be specified as a
hexadecimal ID by prefixing the value with "0x".
These IDs are
required when using multimaster replication and each master must have a
unique ID. Note that this requirement also applies to separate masters
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.
Example:
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.
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
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 OpenSSL. Example:
olcTLSCipherSuite: HIGH:MEDIUM:+SSLv2
To check what ciphers a given spec selects in OpenSSL, use:
openssl ciphers -v <cipher-suite-spec>
To obtain the list of ciphers in GNUtls use:
gnutls-cli -l
olcTLSCACertificateFile: <filename>
Specifies the file that contains certificates for all of the Certificate
Authorities that
slapd
will recognize.
olcTLSCACertificatePath: <path>
Specifies the path of a directory that contains 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. This directive is not supported
when using GNUtls.
olcTLSCertificateFile: <filename>
Specifies the file that contains the
slapd
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. If multiple sets of parameters are present in the file, all of
them will be processed. Note that setting this option may also enable
Anonymous Diffie-Hellman key exchanges in certain non-default cipher suites.
You should append "!ADH" to your cipher suites if you have changed them
from the default, otherwise no certificate exchanges or verification will
be done. When using GNUtls these parameters are always generated randomly
so this directive is ignored.
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 terminated.
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.
DYNAMIC MODULE OPTIONS
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 entries.
olcModuleLoad: <filename>
Specify the name of a dynamically loadable module to load. 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 /usr/lib/ldap, which is where the standard OpenLDAP install
will place its modules.
SCHEMA OPTIONS
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.
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.)
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
description.)
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.
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.
GENERAL BACKEND OPTIONS
Options in these entries only apply to the configuration of a single
type of backend. All backends may support this class of options.
The entry must be named
olcBackend=<databasetype>,cn=config
and must have the olcBackendConfig objectClass.
<databasetype>
should be one of
bdb,
config,
dnssrv,
hdb,
ldap,
ldif,
meta,
monitor,
null,
passwd,
perl,
relay,
shell,
or
sql.
At present, no backend implements any options of this type.
DATABASE OPTIONS
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}".
GLOBAL DATABASE OPTIONS
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 database.
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 entry.
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.
{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 conditions.
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 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 "cn=Subschema".
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.
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.
Extra args can be added in the same value or as additional values.
See
olcLimits
for an explanation 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 or as additional values.
See
olcLimits
for an explanation of the different flags.
GENERAL DATABASE OPTIONS
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 here.
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.
olcLimits: <selector> <limit> [<limit> [...]]
Specify time and size limits based on the operation's initiator or
base DN.
The argument
<selector>
can be any of
<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
disable,
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
size.pr={<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>|unlimited|disabled}
allows to set a limit on the total number of entries that a pagedResults
control allows to return.
By default it is set to the
hard
limit.
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.
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.
olcMirrorMode: TRUE | FALSE
This option puts a replica database into "mirror" mode. Update
operations will be accepted from any user, not just the updatedn. The
database must already be configured as 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.
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. Note that the rootdn is always needed when using syncrepl.
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 encouraged.
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),
or
slapindex(8)
are used on the superior database, any glued subordinates that support
these tools are opened as well.
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.
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.
Specify the current database as a replica which is kept up-to-date with the
master content by establishing the current
slapd(8)
as a replication consumer site running a
syncrepl
replication engine.
The replica content is kept synchronized to the master 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 having no more than three decimal digits.
provider
specifies the replication provider site containing the master 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
replica 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".
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 operation.
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 master replica will generate
searchResultEntry
to the consumer slapd as the search responses to the persistent
synchronization search.
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.
The schema checking can be enforced at the LDAP Sync
consumer site by turning on the
schemachecking
parameter. The default is off.
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).
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.
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 provider, other than allow 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 (limits directive).
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" and the other TLS settings
default to the same as the main slapd TLS settings.
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.
olcUpdateDN: <dn>
This option is only applicable in a slave
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 master.
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.
DATABASE-SPECIFIC OPTIONS
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 backends.
OVERLAYS
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
Here is a short example of a configuration in LDIF suitable for use with
slapadd(8)
:
dn: cn=config
objectClass: olcGlobal
cn: config
olcPidFile: /var/run/slapd.pid
olcAttributeOptions: x-hidden lang-
dn: cn=schema,cn=config
objectClass: olcSchemaConfig
cn: schema
include: /etc/ldap/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=bdb,cn=config
objectClass: olcDatabaseConfig
objectClass: olcBdbConfig
olcDatabase: bdb
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: /var/lib/ldap
# 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://ldap.some-server.com/
Assuming the above data was saved in a file named "config.ldif" and the
/etc/ldap/slapd.d directory has been created, this command will initialize
the configuration:
slapadd -F /etc/ldap/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:
OpenLDAP Software
is developed and maintained by The OpenLDAP Project <http://www.openldap.org/>.
OpenLDAP Software
is derived from University of Michigan LDAP 3.3 Release.