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1475 lines
54 KiB
Plaintext
1475 lines
54 KiB
Plaintext
s# $OpenLDAP$
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# Copyright 2005-2007 The OpenLDAP Foundation, All Rights Reserved.
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# COPYING RESTRICTIONS APPLY, see COPYRIGHT.
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H1: Configuring slapd
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Once the software has been built and installed, you are ready
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to configure {{slapd}}(8) for use at your site. Unlike previous
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OpenLDAP releases, the slapd(8) runtime configuration in 2.3 (and later)
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is fully LDAP-enabled and can be managed using the standard LDAP
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operations with data in {{TERM:LDIF}}. The LDAP configuration engine
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allows all of slapd's configuration options to be changed on the fly,
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generally without requiring a server restart for the changes
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to take effect. The old style {{slapd.conf}}(5) file is still
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supported, but must be converted to the new {{slapd-config}}(5) format
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to allow runtime changes to be saved. While the old style
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configuration uses a single file, normally installed as
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{{F:/usr/local/etc/openldap/slapd.conf}}, the new style
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uses a slapd backend database to store the configuration. The
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configuration database normally resides in the
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{{F:/usr/local/etc/openldap/slapd.d}} directory. When
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converting from the slapd.conf format to slapd.d format, any
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include files will also be integrated into the resulting configuration
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database.
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An alternate configuration directory (or file) can be specified via
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a command-line option to {{slapd}}(8). This chapter describes the
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general format of the configuration system, followed by a detailed
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description of commonly used config settings.
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Note: some of the backends and of the distributed overlays
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do not support runtime configuration yet. In those cases,
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the old style {{slapd.conf}}(5) file must be used.
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H2: Configuration Layout
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The slapd configuration is stored as a special LDAP directory with
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a predefined schema and DIT. There are specific objectClasses used to
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carry global configuration options, schema definitions, backend and
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database definitions, and assorted other items. A sample config tree
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is shown in Figure 5.1.
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!import "config_dit.png"; align="center"; title="Sample configuration tree"
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FT[align="Center"] Figure 5.1: Sample configuration tree.
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Other objects may be part of the configuration but were omitted from
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the illustration for clarity.
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The {{slapd-config}} configuration tree has a very specific structure. The
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root of the tree is named {{EX:cn=config}} and contains global configuration
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settings. Additional settings are contained in separate child entries:
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* Dynamically loaded modules
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.. These may only be used if the {{EX:--enable-modules}} option was
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used to configure the software.
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* Schema definitions
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.. The {{EX:cn=schema,cn=config}} entry contains the system schema (all
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the schema that is hard-coded in slapd).
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.. Child entries of {{EX:cn=schema,cn=config}} contain user schema as
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loaded from config files or added at runtime.
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* Backend-specific configuration
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* Database-specific configuration
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.. Overlays are defined in children of the Database entry.
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.. Databases and Overlays may also have other miscellaneous children.
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The usual rules for LDIF files apply to the configuration information:
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Comment lines beginning with a '{{EX:#}}' character
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are ignored. If a line begins with a single space, it is considered a
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continuation of the previous line (even if the previous line is a
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comment) and the single leading space is removed. Entries are separated by blank lines.
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The general layout of the config LDIF is as follows:
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> # global configuration settings
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> dn: cn=config
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> objectClass: olcGlobal
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> cn: config
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> <global config settings>
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>
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> # schema definitions
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> dn: cn=schema,cn=config
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> objectClass: olcSchemaConfig
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> cn: schema
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> <system schema>
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>
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> dn: cn={X}core,cn=schema,cn=config
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> objectClass: olcSchemaConfig
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> cn: {X}core
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> <core schema>
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>
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> # additional user-specified schema
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> ...
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>
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> # backend definitions
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> dn: olcBackend=<typeA>,cn=config
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> objectClass: olcBackendConfig
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> olcBackend: <typeA>
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> <backend-specific settings>
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>
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> # database definitions
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> dn: olcDatabase={X}<typeA>,cn=config
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> objectClass: olcDatabaseConfig
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> olcDatabase: {X}<typeA>
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> <database-specific settings>
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>
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> # subsequent definitions and settings
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> ...
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Some of the entries listed above have a numeric index {{EX:"{X}"}} in
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their names. While most configuration settings have an inherent ordering
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dependency (i.e., one setting must take effect before a subsequent one
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may be set), LDAP databases are inherently unordered. The numeric index
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is used to enforce a consistent ordering in the configuration database,
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so that all ordering dependencies are preserved. In most cases the index
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does not have to be provided; it will be automatically generated based
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on the order in which entries are created.
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Configuration directives are specified as values of individual
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attributes.
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Most of the attributes and objectClasses used in the slapd
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configuration have a prefix of {{EX:"olc"}} (OpenLDAP Configuration)
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in their names. Generally there is a one-to-one correspondence
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between the attributes and the old-style {{EX:slapd.conf}} configuration
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keywords, using the keyword as the attribute name, with the "olc"
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prefix attached.
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A configuration directive may take arguments. If so, the arguments are
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separated by white space. If an argument contains white space,
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the argument should be enclosed in double quotes {{EX:"like this"}}.
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In the descriptions that follow, arguments that should be replaced
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by actual text are shown in brackets {{EX:<>}}.
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The distribution contains an example configuration file that will
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be installed in the {{F: /usr/local/etc/openldap}} directory.
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A number of files containing schema definitions (attribute types
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and object classes) are also provided in the
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{{F: /usr/local/etc/openldap/schema}} directory.
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H2: Configuration Directives
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This section details commonly used configuration directives. For
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a complete list, see the {{slapd-config}}(5) manual page. This section
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will treat the configuration directives in a top-down order, starting
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with the global directives in the {{EX:cn=config}} entry. Each
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directive will be described along with its default value (if any) and
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an example of its use.
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H3: cn=config
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Directives contained in this entry generally apply to the server as a whole.
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Most of them are system or connection oriented, not database related. This
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entry must have the {{EX:olcGlobal}} objectClass.
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H4: olcIdleTimeout: <integer>
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Specify the number of seconds to wait before forcibly closing
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an idle client connection. A value of 0, the default,
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disables this feature.
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H4: olcLogLevel: <level>
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This directive specifies the level at which debugging statements
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and operation statistics should be syslogged (currently logged to
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the {{syslogd}}(8) {{EX:LOG_LOCAL4}} facility). You must have
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configured OpenLDAP {{EX:--enable-debug}} (the default) for this
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to work (except for the two statistics levels, which are always
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enabled). Log levels may be specified as integers or by keyword.
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Multiple log levels may be used and the levels are additive.
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To display what levels
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correspond to what kind of debugging, invoke slapd with {{EX:-?}}
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or consult the table below. The possible values for <level> are:
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!block table; colaligns="RL"; align=Center; \
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title="Table 5.1: Debugging Levels"
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Level Keyword Description
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-1 Any enable all debugging
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0 no debugging
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1 Trace trace function calls
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2 Packets debug packet handling
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4 Args heavy trace debugging
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8 Conns connection management
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16 BER print out packets sent and received
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32 Filter search filter processing
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64 Config configuration processing
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128 ACL access control list processing
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256 Stats stats log connections/operations/results
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512 Stats2 stats log entries sent
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1024 Shell print communication with shell backends
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2048 Parse print entry parsing debugging
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4096 Cache database cache processing
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8192 Index database indexing
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16384 Sync syncrepl consumer processing
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!endblock
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\Example:
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E: olcLogLevel: -1
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This will cause lots and lots of debugging information to be
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logged.
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E: olcLogLevel: Conns Filter
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Just log the connection and search filter processing.
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\Default:
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E: olcLogLevel: Stats
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H4: olcReferral <URI>
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This directive specifies the referral to pass back when slapd
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cannot find a local database to handle a request.
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\Example:
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> olcReferral: ldap://root.openldap.org
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This will refer non-local queries to the global root LDAP server
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at the OpenLDAP Project. Smart LDAP clients can re-ask their
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query at that server, but note that most of these clients are
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only going to know how to handle simple LDAP URLs that
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contain a host part and optionally a distinguished name part.
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H4: Sample Entry
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>dn: cn=config
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>objectClass: olcGlobal
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>cn: config
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>olcIdleTimeout: 30
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>olcLogLevel: Stats
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>olcReferral: ldap://root.openldap.org
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H3: cn=module
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If support for dynamically loaded modules was enabled when configuring
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slapd, {{EX:cn=module}} entries may be used to specify sets of modules to load.
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Module entries must have the {{EX:olcModuleList}} objectClass.
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H4: olcModuleLoad: <filename>
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Specify the name of a dynamically loadable module to load. The filename
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may be an absolute path name or a simple filename. Non-absolute names
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are searched for in the directories specified by the {{EX:olcModulePath}}
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directive.
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H4: olcModulePath: <pathspec>
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Specify a list of directories to search for loadable modules. Typically the
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path is colon-separated but this depends on the operating system.
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H4: Sample Entries
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>dn: cn=module{0},cn=config
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>objectClass: olcModuleList
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>cn: module{0}
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>olcModuleLoad: /usr/local/lib/smbk5pwd.la
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>
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>dn: cn=module{1},cn=config
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>objectClass: olcModuleList
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>cn: module{1}
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>olcModulePath: /usr/local/lib:/usr/local/lib/slapd
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>olcModuleLoad: accesslog.la
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>olcModuleLoad: pcache.la
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H3: cn=schema
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The cn=schema entry holds all of the schema definitions that are hard-coded
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in slapd. As such, the values in this entry are generated by slapd so no
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schema values need to be provided in the config file. The entry must still
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be defined though, to serve as a base for the user-defined schema to add
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in underneath. Schema entries must have the {{EX:olcSchemaConfig}}
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objectClass.
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H4: olcAttributeTypes: <{{REF:RFC4512}} Attribute Type Description>
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This directive defines an attribute type.
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Please see the {{SECT:Schema Specification}} chapter
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for information regarding how to use this directive.
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H4: olcObjectClasses: <{{REF:RFC4512}} Object Class Description>
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This directive defines an object class.
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Please see the {{SECT:Schema Specification}} chapter for
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information regarding how to use this directive.
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H4: Sample Entries
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>dn: cn=schema,cn=config
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>objectClass: olcSchemaConfig
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>cn: schema
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>
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>dn: cn=test,cn=schema,cn=config
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>objectClass: olcSchemaConfig
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>cn: test
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>olcAttributeTypes: ( 1.1.1
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> NAME 'testAttr'
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> EQUALITY integerMatch
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> SYNTAX 1.3.6.1.4.1.1466.115.121.1.27 )
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>olcAttributeTypes: ( 1.1.2 NAME 'testTwo' EQUALITY caseIgnoreMatch
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> SUBSTR caseIgnoreSubstringsMatch SYNTAX 1.3.6.1.4.1.1466.115.121.1.44 )
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>olcObjectClasses: ( 1.1.3 NAME 'testObject'
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> MAY ( testAttr $ testTwo ) AUXILIARY )
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H3: Backend-specific Directives
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Backend directives apply to all database instances of the
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same type and, depending on the directive, may be overridden
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by database directives. Backend entries must have the
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{{EX:olcBackendConfig}} objectClass.
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H4: olcBackend: <type>
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This directive names a backend-specific configuration entry.
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{{EX:<type>}} should be one of the
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supported backend types listed in Table 5.2.
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!block table; align=Center; coltags="EX,N"; \
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title="Table 5.2: Database Backends"
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Types Description
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bdb Berkeley DB transactional backend
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config Slapd configuration backend
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dnssrv DNS SRV backend
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hdb Hierarchical variant of bdb backend
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ldap Lightweight Directory Access Protocol (Proxy) backend
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ldif Lightweight Data Interchange Format backend
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meta Meta Directory backend
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monitor Monitor backend
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passwd Provides read-only access to {{passwd}}(5)
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perl Perl Programmable backend
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shell Shell (extern program) backend
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sql SQL Programmable backend
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!endblock
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\Example:
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> olcBackend: bdb
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There are no other directives defined for this entry. Specific backend
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types may define additional attributes for their particular use but so
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far none have ever been defined. As such, these directives usually do
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not appear in any actual configurations.
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H4: Sample Entry
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> dn: olcBackend=bdb,cn=config
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> objectClass: olcBackendConfig
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> olcBackend: bdb
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H3: Database-specific Directives
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Directives in this section are supported by every type of database.
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Database entries must have the {{EX:olcDatabaseConfig}} objectClass.
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H4: olcDatabase: [{<index>}]<type>
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This directive names a specific database instance. The numeric {<index>} may
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be provided to distinguish multiple databases of the same type. Usually the
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index can be omitted, and slapd will generate it automatically.
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{{EX:<type>}} should be one of the
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supported backend types listed in Table 5.2 or the {{EX:frontend}} type.
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The {{EX:frontend}} is a special database that is used to hold
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database-level options that should be applied to all the other
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databases. Subsequent database definitions may also override some
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frontend settings.
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The {{EX:config}} database is also special; both the {{EX:config}} and
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the {{EX:frontend}} databases are always created implicitly even if they
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are not explicitly configured, and they are created before any other
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databases.
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\Example:
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> olcDatabase: bdb
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This marks the beginning of a new {{TERM:BDB}} database instance.
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H4: olcAccess: to <what> [ by <who> [<accesslevel>] [<control>] ]+
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This directive grants access (specified by <accesslevel>) to a
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set of entries and/or attributes (specified by <what>) by one or
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more requestors (specified by <who>).
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See the {{SECT:Access Control}} section of this chapter for a
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summary of basic usage.
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!if 0
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More detailed discussion of this directive can be found in the
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{{SECT:Advanced Access Control}} chapter.
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!endif
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Note: If no {{EX:olcAccess}} directives are specified, the default
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access control policy, {{EX:to * by * read}}, allows all
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users (both authenticated and anonymous) read access.
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Note: Access controls defined in the frontend are appended to all
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other databases' controls.
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H4: olcReadonly { TRUE | FALSE }
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This directive puts the database into "read-only" mode. Any
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attempts to modify the database will return an "unwilling to
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perform" error.
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\Default:
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> olcReadonly: FALSE
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H4: olcRootDN: <DN>
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This directive specifies the DN that is not subject to
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access control or administrative limit restrictions for
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operations on this database. The DN need not refer to
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an entry in this database or even in the directory. The
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DN may refer to a SASL identity.
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Entry-based Example:
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> olcRootDN: "cn=Manager,dc=example,dc=com"
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SASL-based Example:
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> olcRootDN: "uid=root,cn=example.com,cn=digest-md5,cn=auth"
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See the {{SECT:SASL Authentication}} section for information on
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SASL authentication identities.
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H4: olcRootPW: <password>
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This directive can be used to specify a password for the DN for
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the rootdn (when the rootdn is set to a DN within the database).
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\Example:
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> olcRootPW: secret
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It is also permissible to provide a hash of the password in
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{{REF:RFC2307}} form. {{slappasswd}}(8) may be used to generate
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the password hash.
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\Example:
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> olcRootPW: {SSHA}ZKKuqbEKJfKSXhUbHG3fG8MDn9j1v4QN
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The hash was generated using the command {{EX:slappasswd -s secret}}.
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H4: olcSizeLimit: <integer>
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This directive specifies the maximum number of entries to return
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from a search operation.
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\Default:
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> olcSizeLimit: 500
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H4: olcSuffix: <dn suffix>
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This directive specifies the DN suffix of queries that will be
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passed to this backend database. Multiple suffix lines can be
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given, and usually at least one is required for each database
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definition. (Some backend types, such as {{EX:frontend}} and
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{{EX:monitor}} use a hard-coded suffix which may not be overridden
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in the configuration.)
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\Example:
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> olcSuffix: "dc=example,dc=com"
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Queries with a DN ending in "dc=example,dc=com"
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will be passed to this backend.
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Note: When the backend to pass a query to is selected, slapd
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looks at the suffix value(s) in each database definition in the
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order in which they were configured. Thus, if one database suffix is a
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prefix of another, it must appear after it in the configuration.
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H4: olcSyncrepl
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> olcSyncrepl: rid=<replica ID>
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> provider=ldap[s]://<hostname>[:port]
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> [type=refreshOnly|refreshAndPersist]
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> [interval=dd:hh:mm:ss]
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> [retry=[<retry interval> <# of retries>]+]
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> searchbase=<base DN>
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> [filter=<filter str>]
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> [scope=sub|one|base]
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> [attrs=<attr list>]
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> [attrsonly]
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> [sizelimit=<limit>]
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> [timelimit=<limit>]
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> [schemachecking=on|off]
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> [bindmethod=simple|sasl]
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> [binddn=<DN>]
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> [saslmech=<mech>]
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> [authcid=<identity>]
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> [authzid=<identity>]
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> [credentials=<passwd>]
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> [realm=<realm>]
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> [secprops=<properties>]
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> [starttls=yes|critical]
|
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> [tls_cert=<file>]
|
|
> [tls_key=<file>]
|
|
> [tls_cacert=<file>]
|
|
> [tls_cacertdir=<path>]
|
|
> [tls_reqcert=never|allow|try|demand]
|
|
> [tls_ciphersuite=<ciphers>]
|
|
> [tls_crlcheck=none|peer|all]
|
|
> [logbase=<base DN>]
|
|
> [logfilter=<filter str>]
|
|
> [syncdata=default|accesslog|changelog]
|
|
|
|
|
|
This directive specifies the current database as a replica of the
|
|
master content by establishing the current {{slapd}}(8) as a
|
|
replication consumer site running a syncrepl replication engine.
|
|
The master database is located at the replication provider site
|
|
specified by the {{EX:provider}} parameter. The replica database is
|
|
kept up-to-date with the master content using the LDAP Content
|
|
Synchronization protocol. See {{REF:RFC4533}}
|
|
for more information on the protocol.
|
|
|
|
The {{EX:rid}} parameter is used for identification of the current
|
|
{{EX:syncrepl}} directive within the replication consumer server,
|
|
where {{EX:<replica ID>}} uniquely identifies the syncrepl specification
|
|
described by the current {{EX:syncrepl}} directive. {{EX:<replica ID>}}
|
|
is non-negative and is no more than three decimal digits in length.
|
|
|
|
The {{EX:provider}} parameter specifies the replication provider site
|
|
containing the master content as an LDAP URI. The {{EX:provider}}
|
|
parameter specifies a scheme, a host and optionally a port where the
|
|
provider slapd instance can be found. Either a domain name or IP
|
|
address may be used for <hostname>. Examples are
|
|
{{EX:ldap://provider.example.com:389}} or {{EX:ldaps://192.168.1.1:636}}.
|
|
If <port> is not given, the standard LDAP port number (389 or 636) is used.
|
|
Note that the syncrepl uses a consumer-initiated protocol, and hence its
|
|
specification is located at the consumer site, whereas the {{EX:replica}}
|
|
specification is located at the provider site. {{EX:syncrepl}} and
|
|
{{EX:replica}} directives define two independent replication
|
|
mechanisms. They do not represent the replication peers of each other.
|
|
|
|
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 {{EX:searchbase}},
|
|
{{EX:scope}}, {{EX:filter}}, {{EX:attrs}}, {{EX:attrsonly}},
|
|
{{EX:sizelimit}}, and {{EX:timelimit}} parameters as in the normal
|
|
search specification. The {{EX:searchbase}} parameter has no
|
|
default value and must always be specified. The {{EX:scope}} defaults
|
|
to {{EX:sub}}, the {{EX:filter}} defaults to {{EX:(objectclass=*)}},
|
|
{{EX:attrs}} defaults to {{EX:"*,+"}} to replicate all user and operational
|
|
attributes, and {{EX:attrsonly}} is unset by default. Both {{EX:sizelimit}}
|
|
and {{EX:timelimit}} default to "unlimited", and only positive integers
|
|
or "unlimited" may be specified.
|
|
|
|
The {{TERM[expand]LDAP Sync}} protocol has two operation
|
|
types: {{EX:refreshOnly}} and {{EX:refreshAndPersist}}.
|
|
The operation type is specified by the {{EX:type}} parameter.
|
|
In the {{EX:refreshOnly}} operation, the next synchronization search operation
|
|
is periodically rescheduled at an interval time after each
|
|
synchronization operation finishes. The interval is specified
|
|
by the {{EX:interval}} parameter. It is set to one day by default.
|
|
In the {{EX:refreshAndPersist}} operation, a synchronization search
|
|
remains persistent in the provider {{slapd}} instance. Further updates to the
|
|
master replica will generate {{EX: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 three times before stop retrying. + 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 {{EX:schemachecking}} parameter.
|
|
If it is turned on, every replicated entry will be checked for its
|
|
schema as the entry is stored into the replica content.
|
|
Every entry in the replica should contain those attributes
|
|
required by the schema definition.
|
|
If it is turned off, entries will be stored without checking
|
|
schema conformance. The default is off.
|
|
|
|
The {{EX:binddn}} parameter gives the DN to bind as for the
|
|
syncrepl searches to the provider slapd. It should be a DN
|
|
which has read access to the replication content in the
|
|
master database.
|
|
|
|
The {{EX:bindmethod}} is {{EX:simple}} or {{EX:sasl}},
|
|
depending on whether simple password-based authentication or
|
|
{{TERM:SASL}} authentication is to be used when connecting
|
|
to the provider {{slapd}} instance.
|
|
|
|
Simple authentication should not be used unless adequate data
|
|
integrity and confidentiality protections are in place (e.g. TLS
|
|
or IPsec). Simple authentication requires specification of {{EX:binddn}}
|
|
and {{EX:credentials}} parameters.
|
|
|
|
SASL authentication is generally recommended. SASL authentication
|
|
requires specification of a mechanism using the {{EX:saslmech}} parameter.
|
|
Depending on the mechanism, an authentication identity and/or
|
|
credentials can be specified using {{EX:authcid}} and {{EX:credentials}},
|
|
respectively. The {{EX:authzid}} parameter may be used to specify
|
|
an authorization identity.
|
|
|
|
The {{EX:realm}} parameter specifies a realm which a certain
|
|
mechanisms authenticate the identity within. The {{EX:secprops}}
|
|
parameter specifies Cyrus SASL security properties.
|
|
|
|
The {{EX:starttls}} parameter specifies use of the StartTLS extended
|
|
operation to establish a TLS session before authenticating to the provider.
|
|
If the {{EX:critical}} argument is supplied, the session will be aborted
|
|
if the StartTLS request fails. Otherwise the syncrepl session continues
|
|
without TLS. Note that the main slapd TLS settings are not used by the
|
|
syncrepl engine; by default the TLS parameters from a {{ldap.conf}}(5)
|
|
configuration file will be used. TLS settings may be specified here,
|
|
in which case any {{ldap.conf}}(5) settings will be completely ignored.
|
|
|
|
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
|
|
{{EX:logbase}} and {{EX:logfilter}} parameters must be set appropriately
|
|
for the log that will be used. The {{EX:syncdata}} parameter must
|
|
be set to either {{EX:"accesslog"}} if the log conforms to the
|
|
{{slapo-accesslog}}(5) log format, or {{EX:"changelog"}} if the log
|
|
conforms to the obsolete {{changelog}} format. If the {{EX:syncdata}}
|
|
parameter is omitted or set to {{EX:"default"}} then the log
|
|
parameters are ignored.
|
|
|
|
The {{syncrepl}} replication mechanism is supported by the {{bdb}} and
|
|
{{hdb}} backends.
|
|
|
|
See the {{SECT:LDAP Sync Replication}} chapter of this guide for
|
|
more information on how to use this directive.
|
|
|
|
|
|
H4: olcTimeLimit: <integer>
|
|
|
|
This directive specifies the maximum number of seconds (in real
|
|
time) slapd will spend answering a search request. If a
|
|
request is not finished in this time, a result indicating an
|
|
exceeded timelimit will be returned.
|
|
|
|
\Default:
|
|
|
|
> olcTimeLimit: 3600
|
|
|
|
|
|
H4: olcUpdateref: <URL>
|
|
|
|
This directive is only applicable in a slave slapd. It
|
|
specifies the URL to return to clients which submit update
|
|
requests upon the replica.
|
|
If specified multiple times, each {{TERM:URL}} is provided.
|
|
|
|
\Example:
|
|
|
|
> olcUpdateref: ldap://master.example.net
|
|
|
|
|
|
H4: Sample Entries
|
|
|
|
>dn: olcDatabase=frontend,cn=config
|
|
>objectClass: olcDatabaseConfig
|
|
>objectClass: olcFrontendConfig
|
|
>olcDatabase: frontend
|
|
>olcReadOnly: FALSE
|
|
>
|
|
>dn: olcDatabase=config,cn=config
|
|
>objectClass: olcDatabaseConfig
|
|
>olcDatabase: config
|
|
>olcRootDN: cn=Manager,dc=example,dc=com
|
|
|
|
|
|
H3: BDB and HDB Database Directives
|
|
|
|
Directives in this category apply to both the {{TERM:BDB}}
|
|
and the {{TERM:HDB}} database.
|
|
They are used in an olcDatabase entry in addition to the generic
|
|
database directives defined above. For a complete reference
|
|
of BDB/HDB configuration directives, see {{slapd-bdb}}(5). In
|
|
addition to the {{EX:olcDatabaseConfig}} objectClass, BDB and HDB
|
|
database entries must have the {{EX:olcBdbConfig}} and
|
|
{{EX:olcHdbConfig}} objectClass, respectively.
|
|
|
|
|
|
H4: olcDbDirectory: <directory>
|
|
|
|
This directive specifies the directory where the BDB files
|
|
containing the database and associated indices live.
|
|
|
|
\Default:
|
|
|
|
> olcDbDirectory: /usr/local/var/openldap-data
|
|
|
|
|
|
H4: olcDbCachesize: <integer>
|
|
|
|
This directive specifies the size in entries of the in-memory
|
|
cache maintained by the BDB backend database instance.
|
|
|
|
\Default:
|
|
|
|
> olcDbCachesize: 1000
|
|
|
|
|
|
H4: olcDbCheckpoint: <kbyte> <min>
|
|
|
|
This directive specifies how often to checkpoint the BDB transaction log.
|
|
A checkpoint operation flushes the database buffers to disk and writes a
|
|
checkpoint record in the log.
|
|
The checkpoint will occur if either <kbyte> data has been written or
|
|
<min> minutes have passed since the last checkpoint. Both arguments default
|
|
to zero, in which case they are ignored. When the <min> argument is
|
|
non-zero, an internal task will run every <min> minutes to perform the
|
|
checkpoint. See the Berkeley DB reference guide for more details.
|
|
|
|
\Example:
|
|
|
|
> olcDbCheckpoint: 1024 10
|
|
|
|
|
|
H4: olcDbConfig: <DB_CONFIG setting>
|
|
|
|
This attribute specifies a configuration directive to be placed in the
|
|
{{EX:DB_CONFIG}} file of the database directory. At server startup time, if
|
|
no such file exists yet, the {{EX:DB_CONFIG}} file will be created and the
|
|
settings in this attribute will be written to it. If the file exists,
|
|
its contents will be read and displayed in this attribute. The attribute
|
|
is multi-valued, to accommodate multiple configuration directives. No default
|
|
is provided, but it is essential to use proper settings here to get the
|
|
best server performance.
|
|
|
|
Any changes made to this attribute will be written to the {{EX:DB_CONFIG}}
|
|
file and will cause the database environment to be reset so the changes
|
|
can take immediate effect. If the environment cache is large and has not
|
|
been recently checkpointed, this reset operation may take a long time. It
|
|
may be advisable to manually perform a single checkpoint using the Berkeley DB
|
|
{{db_checkpoint}} utility before using LDAP Modify to change this
|
|
attribute.
|
|
|
|
\Example:
|
|
|
|
> olcDbConfig: set_cachesize 0 10485760 0
|
|
> olcDbConfig: set_lg_bsize 2097512
|
|
> olcDbConfig: set_lg_dir /var/tmp/bdb-log
|
|
> olcDbConfig: set_flags DB_LOG_AUTOREMOVE
|
|
|
|
In this example, the BDB cache is set to 10MB, the BDB transaction log
|
|
buffer size is set to 2MB, and the transaction log files are to be stored
|
|
in the /var/tmp/bdb-log directory. Also a flag is set to tell BDB to
|
|
delete transaction log files as soon as their contents have been
|
|
checkpointed and they are no longer needed. Without this setting the
|
|
transaction log files will continue to accumulate until some other
|
|
cleanup procedure removes them. See the Berkeley DB documentation for the
|
|
{{EX:db_archive}} command for details.
|
|
|
|
Ideally the BDB cache must be
|
|
at least as large as the working set of the database, the log buffer size
|
|
should be large enough to accommodate most transactions without overflowing,
|
|
and the log directory must be on a separate physical disk from the main
|
|
database files. And both the database directory and the log directory
|
|
should be separate from disks used for regular system activities such as
|
|
the root, boot, or swap filesystems. See the FAQ-o-Matic and the Berkeley DB
|
|
documentation for more details.
|
|
|
|
|
|
H4: olcDbNosync: { TRUE | FALSE }
|
|
|
|
This option causes on-disk database contents to not be immediately
|
|
synchronized with in memory changes upon change. Setting this option
|
|
to {{EX:TRUE}} may improve performance at the expense of data integrity. This
|
|
directive has the same effect as using
|
|
> olcDbConfig: set_flags DB_TXN_NOSYNC
|
|
|
|
|
|
H4: olcDbIDLcacheSize: <integer>
|
|
|
|
Specify the size of the in-memory index cache, in index slots. The
|
|
default is zero. A larger value will speed up frequent searches of
|
|
indexed entries. The optimal size will depend on the data and search
|
|
characteristics of the database, but using a number three times
|
|
the entry cache size is a good starting point.
|
|
|
|
\Example:
|
|
|
|
> olcDbIDLcacheSize: 3000
|
|
|
|
|
|
H4: olcDbIndex: {<attrlist> | default} [pres,eq,approx,sub,none]
|
|
|
|
This directive specifies the indices to maintain for the given
|
|
attribute. If only an {{EX:<attrlist>}} is given, the default
|
|
indices are maintained. The index keywords correspond to the
|
|
common types of matches that may be used in an LDAP search filter.
|
|
|
|
\Example:
|
|
|
|
> olcDbIndex: default pres,eq
|
|
> olcDbIndex: uid
|
|
> olcDbIndex: cn,sn pres,eq,sub
|
|
> olcDbIndex: objectClass eq
|
|
|
|
The first line sets the default set of indices to maintain to
|
|
present and equality. The second line causes the default (pres,eq)
|
|
set of indices to be maintained for the {{EX:uid}} attribute type.
|
|
The third line causes present, equality, and substring indices to
|
|
be maintained for {{EX:cn}} and {{EX:sn}} attribute types. The
|
|
fourth line causes an equality index for the {{EX:objectClass}}
|
|
attribute type.
|
|
|
|
There is no index keyword for inequality matches. Generally these
|
|
matches do not use an index. However, some attributes do support
|
|
indexing for inequality matches, based on the equality index.
|
|
|
|
A substring index can be more explicitly specified as {{EX:subinitial}},
|
|
{{EX:subany}}, or {{EX:subfinal}}, corresponding to the three
|
|
possible components
|
|
of a substring match filter. A subinitial index only indexes
|
|
substrings that appear at the beginning of an attribute value.
|
|
A subfinal index only indexes substrings that appear at the end
|
|
of an attribute value, while subany indexes substrings that occur
|
|
anywhere in a value.
|
|
|
|
Note that by default, setting an index for an attribute also
|
|
affects every subtype of that attribute. E.g., setting an equality
|
|
index on the {{EX:name}} attribute causes {{EX:cn}}, {{EX:sn}}, and every other
|
|
attribute that inherits from {{EX:name}} to be indexed.
|
|
|
|
By default, no indices are maintained. It is generally advised
|
|
that minimally an equality index upon objectClass be maintained.
|
|
|
|
> olcDbindex: objectClass eq
|
|
|
|
Additional indices should be configured corresponding to the
|
|
most common searches that are used on the database.
|
|
Presence indexing should not be configured for an attribute
|
|
unless the attribute occurs very rarely in the database, and
|
|
presence searches on the attribute occur very frequently during
|
|
normal use of the directory. Most applications don't use presence
|
|
searches, so usually presence indexing is not very useful.
|
|
|
|
If this setting is changed while slapd is running, an internal task
|
|
will be run to generate the changed index data. All server operations
|
|
can continue as normal while the indexer does its work. If slapd is
|
|
stopped before the index task completes, indexing will have to be
|
|
manually completed using the slapindex tool.
|
|
|
|
|
|
H4: olcDbLinearIndex: { TRUE | FALSE }
|
|
|
|
If this setting is {{EX:TRUE}} slapindex will index one attribute
|
|
at a time. The default settings is {{EX:FALSE}} in which case all
|
|
indexed attributes of an entry are processed at the same time. When
|
|
enabled, each indexed attribute is processed individually, using
|
|
multiple passes through the entire database. This option improves
|
|
slapindex performance when the database size exceeds the BDB cache
|
|
size. When the BDB cache is large enough, this option is not needed
|
|
and will decrease performance. Also by default, slapadd performs
|
|
full indexing and so a separate slapindex run is not needed. With
|
|
this option, slapadd does no indexing and slapindex must be used.
|
|
|
|
|
|
H4: olcDbMode: <integer>
|
|
|
|
This directive specifies the file protection mode that newly
|
|
created database index files should have.
|
|
|
|
\Default:
|
|
|
|
> olcDbMode: 0600
|
|
|
|
|
|
H4: olcDbSearchStack: <integer>
|
|
|
|
Specify the depth of the stack used for search filter evaluation.
|
|
Search filters are evaluated on a stack to accommodate nested {{EX:AND}} /
|
|
{{EX:OR}} clauses. An individual stack is allocated for each server thread.
|
|
The depth of the stack determines how complex a filter can be evaluated
|
|
without requiring any additional memory allocation. Filters that are
|
|
nested deeper than the search stack depth will cause a separate stack to
|
|
be allocated for that particular search operation. These separate allocations
|
|
can have a major negative impact on server performance, but specifying
|
|
too much stack will also consume a great deal of memory. Each search
|
|
uses 512K bytes per level on a 32-bit machine, or 1024K bytes per level
|
|
on a 64-bit machine. The default stack depth is 16, thus 8MB or 16MB
|
|
per thread is used on 32 and 64 bit machines, respectively. Also the
|
|
512KB size of a single stack slot is set by a compile-time constant which
|
|
may be changed if needed; the code must be recompiled for the change
|
|
to take effect.
|
|
|
|
\Default:
|
|
|
|
> olcDbSearchStack: 16
|
|
|
|
|
|
H4: olcDbShmKey: <integer>
|
|
|
|
Specify a key for a shared memory BDB environment. By default the BDB
|
|
environment uses memory mapped files. If a non-zero value is specified,
|
|
it will be used as the key to identify a shared memory region that will
|
|
house the environment.
|
|
|
|
\Example:
|
|
|
|
> olcDbShmKey: 42
|
|
|
|
|
|
H4: Sample Entry
|
|
|
|
>dn: olcDatabase=hdb,cn=config
|
|
>objectClass: olcDatabaseConfig
|
|
>objectClass: olcHdbConfig
|
|
>olcDatabase: hdb
|
|
>olcSuffix: "dc=example,dc=com"
|
|
>olcDbDirectory: /usr/local/var/openldap-data
|
|
>olcDbCacheSize: 1000
|
|
>olcDbCheckpoint: 1024 10
|
|
>olcDbConfig: set_cachesize 0 10485760 0
|
|
>olcDbConfig: set_lg_bsize 2097152
|
|
>olcDbConfig: set_lg_dir /var/tmp/bdb-log
|
|
>olcDbConfig: set_flags DB_LOG_AUTOREMOVE
|
|
>olcDbIDLcacheSize: 3000
|
|
>olcDbIndex: objectClass eq
|
|
|
|
|
|
H2: Access Control
|
|
|
|
Access to slapd entries and attributes is controlled by the
|
|
olcAccess attribute, whose values are a sequence of access directives.
|
|
The general form of the olcAccess configuration is:
|
|
|
|
> olcAccess: <access directive>
|
|
> <access directive> ::= to <what>
|
|
> [by <who> [<access>] [<control>] ]+
|
|
> <what> ::= * |
|
|
> [dn[.<basic-style>]=<regex> | dn.<scope-style>=<DN>]
|
|
> [filter=<ldapfilter>] [attrs=<attrlist>]
|
|
> <basic-style> ::= regex | exact
|
|
> <scope-style> ::= base | one | subtree | children
|
|
> <attrlist> ::= <attr> [val[.<basic-style>]=<regex>] | <attr> , <attrlist>
|
|
> <attr> ::= <attrname> | entry | children
|
|
> <who> ::= * | [anonymous | users | self
|
|
> | dn[.<basic-style>]=<regex> | dn.<scope-style>=<DN>]
|
|
> [dnattr=<attrname>]
|
|
> [group[/<objectclass>[/<attrname>][.<basic-style>]]=<regex>]
|
|
> [peername[.<basic-style>]=<regex>]
|
|
> [sockname[.<basic-style>]=<regex>]
|
|
> [domain[.<basic-style>]=<regex>]
|
|
> [sockurl[.<basic-style>]=<regex>]
|
|
> [set=<setspec>]
|
|
> [aci=<attrname>]
|
|
> <access> ::= [self]{<level>|<priv>}
|
|
> <level> ::= none | disclose | auth | compare | search | read | write | manage
|
|
> <priv> ::= {=|+|-}{m|w|r|s|c|x|d|0}+
|
|
> <control> ::= [stop | continue | break]
|
|
|
|
where the <what> part selects the entries and/or attributes to which
|
|
the access applies, the {{EX:<who>}} part specifies which entities
|
|
are granted access, and the {{EX:<access>}} part specifies the
|
|
access granted. Multiple {{EX:<who> <access> <control>}} triplets
|
|
are supported, allowing many entities to be granted different access
|
|
to the same set of entries and attributes. Not all of these access
|
|
control options are described here; for more details see the
|
|
{{slapd.access}}(5) man page.
|
|
|
|
|
|
H3: What to control access to
|
|
|
|
The <what> part of an access specification determines the entries
|
|
and attributes to which the access control applies. Entries are
|
|
commonly selected in two ways: by DN and by filter. The following
|
|
qualifiers select entries by DN:
|
|
|
|
> to *
|
|
> to dn[.<basic-style>]=<regex>
|
|
> to dn.<scope-style>=<DN>
|
|
|
|
The first form is used to select all entries. The second form may
|
|
be used to select entries by matching a regular expression against
|
|
the target entry's {{normalized DN}}. (The second form is not
|
|
discussed further in this document.) The third form is used to
|
|
select entries which are within the requested scope of DN. The
|
|
<DN> is a string representation of the Distinguished Name, as
|
|
described in {{REF:RFC4514}}.
|
|
|
|
The scope can be either {{EX:base}}, {{EX:one}}, {{EX:subtree}},
|
|
or {{EX:children}}. Where {{EX:base}} matches only the entry with
|
|
provided DN, {{EX:one}} matches the entries whose parent is the
|
|
provided DN, {{EX:subtree}} matches all entries in the subtree whose
|
|
root is the provided DN, and {{EX:children}} matches all entries
|
|
under the DN (but not the entry named by the DN).
|
|
|
|
For example, if the directory contained entries named:
|
|
|
|
> 0: o=suffix
|
|
> 1: cn=Manager,o=suffix
|
|
> 2: ou=people,o=suffix
|
|
> 3: uid=kdz,ou=people,o=suffix
|
|
> 4: cn=addresses,uid=kdz,ou=people,o=suffix
|
|
> 5: uid=hyc,ou=people,o=suffix
|
|
|
|
\Then:
|
|
. {{EX:dn.base="ou=people,o=suffix"}} match 2;
|
|
. {{EX:dn.one="ou=people,o=suffix"}} match 3, and 5;
|
|
. {{EX:dn.subtree="ou=people,o=suffix"}} match 2, 3, 4, and 5; and
|
|
. {{EX:dn.children="ou=people,o=suffix"}} match 3, 4, and 5.
|
|
|
|
|
|
Entries may also be selected using a filter:
|
|
|
|
> to filter=<ldap filter>
|
|
|
|
where <ldap filter> is a string representation of an LDAP
|
|
search filter, as described in {{REF:RFC4515}}. For example:
|
|
|
|
> to filter=(objectClass=person)
|
|
|
|
Note that entries may be selected by both DN and filter by
|
|
including both qualifiers in the <what> clause.
|
|
|
|
> to dn.one="ou=people,o=suffix" filter=(objectClass=person)
|
|
|
|
Attributes within an entry are selected by including a comma-separated
|
|
list of attribute names in the <what> selector:
|
|
|
|
> attrs=<attribute list>
|
|
|
|
A specific value of an attribute is selected by using a single
|
|
attribute name and also using a value selector:
|
|
|
|
> attrs=<attribute> val[.<style>]=<regex>
|
|
|
|
There are two special {{pseudo}} attributes {{EX:entry}} and
|
|
{{EX:children}}. To read (and hence return) a target entry, the
|
|
subject must have {{EX:read}} access to the target's {{entry}}
|
|
attribute. To add or delete an entry, the subject must have
|
|
{{EX:write}} access to the entry's {{EX:entry}} attribute AND must
|
|
have {{EX:write}} access to the entry's parent's {{EX:children}}
|
|
attribute. To rename an entry, the subject must have {{EX:write}}
|
|
access to entry's {{EX:entry}} attribute AND have {{EX:write}}
|
|
access to both the old parent's and new parent's {{EX:children}}
|
|
attributes. The complete examples at the end of this section should
|
|
help clear things up.
|
|
|
|
Lastly, there is a special entry selector {{EX:"*"}} that is used to
|
|
select any entry. It is used when no other {{EX:<what>}}
|
|
selector has been provided. It's equivalent to "{{EX:dn=.*}}"
|
|
|
|
|
|
H3: Who to grant access to
|
|
|
|
The <who> part identifies the entity or entities being granted
|
|
access. Note that access is granted to "entities" not "entries."
|
|
The following table summarizes entity specifiers:
|
|
|
|
!block table; align=Center; coltags="EX,N"; \
|
|
title="Table 5.3: Access Entity Specifiers"
|
|
Specifier|Entities
|
|
*|All, including anonymous and authenticated users
|
|
anonymous|Anonymous (non-authenticated) users
|
|
users|Authenticated users
|
|
self|User associated with target entry
|
|
dn[.<basic-style>]=<regex>|Users matching a regular expression
|
|
dn.<scope-style>=<DN>|Users within scope of a DN
|
|
!endblock
|
|
|
|
The DN specifier behaves much like <what> clause DN specifiers.
|
|
|
|
Other control factors are also supported. For example, a {{EX:<who>}}
|
|
can be restricted by an entry listed in a DN-valued attribute in
|
|
the entry to which the access applies:
|
|
|
|
> dnattr=<dn-valued attribute name>
|
|
|
|
The dnattr specification is used to give access to an entry
|
|
whose DN is listed in an attribute of the entry (e.g., give
|
|
access to a group entry to whoever is listed as the owner of
|
|
the group entry).
|
|
|
|
Some factors may not be appropriate in all environments (or any).
|
|
For example, the domain factor relies on IP to domain name lookups.
|
|
As these can easily spoofed, the domain factor should not be avoided.
|
|
|
|
|
|
H3: The access to grant
|
|
|
|
The kind of <access> granted can be one of the following:
|
|
|
|
!block table; colaligns="LRL"; coltags="EX,EX,N"; align=Center; \
|
|
title="Table 5.4: Access Levels"
|
|
Level Privileges Description
|
|
none =0 no access
|
|
disclose =d needed for information disclosure on error
|
|
auth =dx needed to authenticate (bind)
|
|
compare =cdx needed to compare
|
|
search =scdx needed to apply search filters
|
|
read =rscdx needed to read search results
|
|
write =wrscdx needed to modify/rename
|
|
manage =mwrscdx needed to manage
|
|
!endblock
|
|
|
|
Each level implies all lower levels of access. So, for example,
|
|
granting someone {{EX:write}} access to an entry also grants them
|
|
{{EX:read}}, {{EX:search}}, {{EX:compare}}, {{EX:auth}} and
|
|
{{EX:disclose}} access. However, one may use the privileges specifier
|
|
to grant specific permissions.
|
|
|
|
|
|
H3: Access Control Evaluation
|
|
|
|
When evaluating whether some requester should be given access to
|
|
an entry and/or attribute, slapd compares the entry and/or attribute
|
|
to the {{EX:<what>}} selectors given in the configuration. For
|
|
each entry, access controls provided in the database which holds
|
|
the entry (or the first database if not held in any database) apply
|
|
first, followed by the global access directives (which are held in
|
|
the {{EX:frontend}} database definition). Within this priority,
|
|
access directives are examined in the order in which they appear
|
|
in the configuration attribute. Slapd stops with the first
|
|
{{EX:<what>}} selector that matches the entry and/or attribute. The
|
|
corresponding access directive is the one slapd will use to evaluate
|
|
access.
|
|
|
|
Next, slapd compares the entity requesting access to the {{EX:<who>}}
|
|
selectors within the access directive selected above in the order
|
|
in which they appear. It stops with the first {{EX:<who>}} selector
|
|
that matches the requester. This determines the access the entity
|
|
requesting access has to the entry and/or attribute.
|
|
|
|
Finally, slapd compares the access granted in the selected
|
|
{{EX:<access>}} clause to the access requested by the client. If
|
|
it allows greater or equal access, access is granted. Otherwise,
|
|
access is denied.
|
|
|
|
The order of evaluation of access directives makes their placement
|
|
in the configuration file important. If one access directive is
|
|
more specific than another in terms of the entries it selects, it
|
|
should appear first in the configuration. Similarly, if one {{EX:<who>}}
|
|
selector is more specific than another it should come first in the
|
|
access directive. The access control examples given below should
|
|
help make this clear.
|
|
|
|
|
|
|
|
H3: Access Control Examples
|
|
|
|
The access control facility described above is quite powerful. This
|
|
section shows some examples of its use for descriptive purposes.
|
|
|
|
A simple example:
|
|
|
|
> olcAccess: to * by * read
|
|
|
|
This access directive grants read access to everyone.
|
|
|
|
> olcAccess: to *
|
|
> by self write
|
|
> by anonymous auth
|
|
> by * read
|
|
|
|
This directive allows the user to modify their entry, allows anonymous
|
|
to authenticate against these entries, and allows all others to
|
|
read these entries. Note that only the first {{EX:by <who>}} clause
|
|
which matches applies. Hence, the anonymous users are granted
|
|
{{EX:auth}}, not {{EX:read}}. The last clause could just as well
|
|
have been "{{EX:by users read}}".
|
|
|
|
It is often desirable to restrict operations based upon the level
|
|
of protection in place. The following shows how security strength
|
|
factors (SSF) can be used.
|
|
|
|
> olcAccess: to *
|
|
> by ssf=128 self write
|
|
> by ssf=64 anonymous auth
|
|
> by ssf=64 users read
|
|
|
|
This directive allows users to modify their own entries if security
|
|
protections of strength 128 or better have been established,
|
|
allows authentication access to anonymous users, and read access
|
|
when strength 64 or better security protections have been established. If
|
|
the client has not establish sufficient security protections, the
|
|
implicit {{EX:by * none}} clause would be applied.
|
|
|
|
The following example shows the use of style specifiers to select
|
|
the entries by DN in two access directives where ordering is
|
|
significant.
|
|
|
|
> olcAccess: to dn.children="dc=example,dc=com"
|
|
> by * search
|
|
> olcAccess: to dn.children="dc=com"
|
|
> by * read
|
|
|
|
Read access is granted to entries under the {{EX:dc=com}} subtree,
|
|
except for those entries under the {{EX:dc=example,dc=com}} subtree,
|
|
to which search access is granted. No access is granted to
|
|
{{EX:dc=com}} as neither access directive matches this DN. If the
|
|
order of these access directives was reversed, the trailing directive
|
|
would never be reached, since all entries under {{EX:dc=example,dc=com}}
|
|
are also under {{EX:dc=com}} entries.
|
|
|
|
Also note that if no {{EX:olcAccess: to}} directive matches or no {{EX:by
|
|
<who>}} clause, {{B:access is denied}}. That is, every {{EX:olcAccess:
|
|
to}} directive ends with an implicit {{EX:by * none}} clause and
|
|
every access list ends with an implicit {{EX:olcAccess: to * by * none}}
|
|
directive.
|
|
|
|
The next example again shows the importance of ordering, both of
|
|
the access directives and the {{EX:by <who>}} clauses. It also
|
|
shows the use of an attribute selector to grant access to a specific
|
|
attribute and various {{EX:<who>}} selectors.
|
|
|
|
> olcAccess: to dn.subtree="dc=example,dc=com" attrs=homePhone
|
|
> by self write
|
|
> by dn.children=dc=example,dc=com" search
|
|
> by peername.regex=IP:10\..+ read
|
|
> olcAccess: to dn.subtree="dc=example,dc=com"
|
|
> by self write
|
|
> by dn.children="dc=example,dc=com" search
|
|
> by anonymous auth
|
|
|
|
This example applies to entries in the "{{EX:dc=example,dc=com}}"
|
|
subtree. To all attributes except {{EX:homePhone}}, an entry can
|
|
write to itself, entries under {{EX:example.com}} entries can search
|
|
by them, anybody else has no access (implicit {{EX:by * none}})
|
|
excepting for authentication/authorization (which is always done
|
|
anonymously). The {{EX:homePhone}} attribute is writable by the
|
|
entry, searchable by entries under {{EX:example.com}}, readable by
|
|
clients connecting from network 10, and otherwise not readable
|
|
(implicit {{EX:by * none}}). All other access is denied by the
|
|
implicit {{EX:access to * by * none}}.
|
|
|
|
Sometimes it is useful to permit a particular DN to add or
|
|
remove itself from an attribute. For example, if you would like to
|
|
create a group and allow people to add and remove only
|
|
their own DN from the member attribute, you could accomplish
|
|
it with an access directive like this:
|
|
|
|
> olcAccess: to attrs=member,entry
|
|
> by dnattr=member selfwrite
|
|
|
|
The dnattr {{EX:<who>}} selector says that the access applies to
|
|
entries listed in the {{EX:member}} attribute. The {{EX:selfwrite}} access
|
|
selector says that such members can only add or delete their
|
|
own DN from the attribute, not other values. The addition of
|
|
the entry attribute is required because access to the entry is
|
|
required to access any of the entry's attributes.
|
|
|
|
|
|
|
|
H3: Access Control Ordering
|
|
|
|
Since the ordering of {{EX:olcAccess}} directives is essential to their
|
|
proper evaluation, but LDAP attributes normally do not preserve the
|
|
ordering of their values, OpenLDAP uses a custom schema extension to
|
|
maintain a fixed ordering of these values. This ordering is maintained
|
|
by prepending a {{EX:"{X}"}} numeric index to each value, similarly to
|
|
the approach used for ordering the configuration entries. These index
|
|
tags are maintained automatically by slapd and do not need to be specified
|
|
when originally defining the values. For example, when you create the
|
|
settings
|
|
|
|
> olcAccess: to attrs=member,entry
|
|
> by dnattr=member selfwrite
|
|
> olcAccess: to dn.children="dc=example,dc=com"
|
|
> by * search
|
|
> olcAccess: to dn.children="dc=com"
|
|
> by * read
|
|
|
|
when you read them back using slapcat or ldapsearch they will contain
|
|
|
|
> olcAccess: {0}to attrs=member,entry
|
|
> by dnattr=member selfwrite
|
|
> olcAccess: {1}to dn.children="dc=example,dc=com"
|
|
> by * search
|
|
> olcAccess: {2}to dn.children="dc=com"
|
|
> by * read
|
|
|
|
The numeric index may be used to specify a particular value to change
|
|
when using ldapmodify to edit the access rules. This index can be used
|
|
instead of (or in addition to) the actual access value. Using this
|
|
numeric index is very helpful when multiple access rules are being managed.
|
|
|
|
For example, if we needed to change the second rule above to grant
|
|
write access instead of search, we could try this LDIF:
|
|
|
|
> changetype: modify
|
|
> delete: olcAccess
|
|
> olcAccess: to dn.children="dc=example,dc=com" by * search
|
|
> -
|
|
> add: olcAccess
|
|
> olcAccess: to dn.children="dc=example,dc=com" by * write
|
|
> -
|
|
|
|
But this example {{B:will not}} guarantee that the existing values remain in
|
|
their original order, so it will most likely yield a broken security
|
|
configuration. Instead, the numeric index should be used:
|
|
|
|
> changetype: modify
|
|
> delete: olcAccess
|
|
> olcAccess: {1}
|
|
> -
|
|
> add: olcAccess
|
|
> olcAccess: {1}to dn.children="dc=example,dc=com" by * write
|
|
> -
|
|
|
|
This example deletes whatever rule is in value #1 of the {{EX:olcAccess}}
|
|
attribute (regardless of its value) and adds a new value that is
|
|
explicitly inserted as value #1. The result will be
|
|
|
|
> olcAccess: {0}to attrs=member,entry
|
|
> by dnattr=member selfwrite
|
|
> olcAccess: {1}to dn.children="dc=example,dc=com"
|
|
> by * write
|
|
> olcAccess: {2}to dn.children="dc=com"
|
|
> by * read
|
|
|
|
which is exactly what was intended.
|
|
|
|
!if 0
|
|
For more details on how to use the {{EX:access}} directive,
|
|
consult the {{Advanced Access Control}} chapter.
|
|
!endif
|
|
|
|
|
|
H2: Configuration Example
|
|
|
|
The following is an example configuration, interspersed
|
|
with explanatory text. It defines two databases to handle
|
|
different parts of the {{TERM:X.500}} tree; both are {{TERM:BDB}}
|
|
database instances. The line numbers shown are provided for
|
|
reference only and are not included in the actual file. First, the
|
|
global configuration section:
|
|
|
|
E: 1. # example config file - global configuration entry
|
|
E: 2. dn: cn=config
|
|
E: 3. objectClass: olcGlobal
|
|
E: 4. cn: config
|
|
E: 5. olcReferral: ldap://root.openldap.org
|
|
E: 6.
|
|
|
|
Line 1 is a comment. Lines 2-4 identify this as the global
|
|
configuration entry.
|
|
The {{EX:olcReferral:}} directive on line 5
|
|
means that queries not local to one of the databases defined
|
|
below will be referred to the LDAP server running on the
|
|
standard port (389) at the host {{EX:root.openldap.org}}.
|
|
Line 6 is a blank line, indicating the end of this entry.
|
|
|
|
E: 7. # internal schema
|
|
E: 8. dn: cn=schema,cn=config
|
|
E: 9. objectClass: olcSchemaConfig
|
|
E: 10. cn: schema
|
|
E: 11.
|
|
|
|
Line 7 is a comment. Lines 8-10 identify this as the root of
|
|
the schema subtree. The actual schema definitions in this entry
|
|
are hardcoded into slapd so no additional attributes are specified here.
|
|
Line 11 is a blank line, indicating the end of this entry.
|
|
|
|
E: 12. # include the core schema
|
|
E: 13. include: file:///usr/local/etc/openldap/schema/core.ldif
|
|
E: 14.
|
|
|
|
Line 12 is a comment. Line 13 is an LDIF include directive which
|
|
accesses the {{core}} schema definitions in LDIF format. Line 14
|
|
is a blank line.
|
|
|
|
Next comes the database definitions. The first database is the
|
|
special {{EX:frontend}} database whose settings are applied globally
|
|
to all the other databases.
|
|
|
|
E: 15. # global database parameters
|
|
E: 16. dn: olcDatabase=frontend,cn=config
|
|
E: 17. objectClass: olcDatabaseConfig
|
|
E: 18. olcDatabase: frontend
|
|
E: 19. olcAccess: to * by * read
|
|
E: 20.
|
|
|
|
Line 15 is a comment. Lines 16-18 identify this entry as the global
|
|
database entry. Line 19 is a global access control. It applies to all
|
|
entries (after any applicable database-specific access controls).
|
|
|
|
The next entry defines a BDB backend that will handle queries for things
|
|
in the "dc=example,dc=com" portion of the tree. Indices are to be maintained
|
|
for several attributes, and the {{EX:userPassword}} attribute is to be
|
|
protected from unauthorized access.
|
|
|
|
E: 21. # BDB definition for example.com
|
|
E: 22. dn: olcDatabase=bdb,cn=config
|
|
E: 23. objectClass: olcDatabaseConfig
|
|
E: 24. objectClass: olcBdbConfig
|
|
E: 25. olcDatabase: bdb
|
|
E: 26. olcSuffix: "dc=example,dc=com"
|
|
E: 27. olcDbDirectory: /usr/local/var/openldap-data
|
|
E: 28. olcRootDN: "cn=Manager,dc=example,dc=com"
|
|
E: 29. olcRootPW: secret
|
|
E: 30. olcDbIndex: uid pres,eq
|
|
E: 31. olcDbIndex: cn,sn,uid pres,eq,approx,sub
|
|
E: 32. olcDbIndex: objectClass eq
|
|
E: 33. olcAccess: to attrs=userPassword
|
|
E: 34. by self write
|
|
E: 35. by anonymous auth
|
|
E: 36. by dn.base="cn=Admin,dc=example,dc=com" write
|
|
E: 37. by * none
|
|
E: 38. olcAccess: to *
|
|
E: 39. by self write
|
|
E: 40. by dn.base="cn=Admin,dc=example,dc=com" write
|
|
E: 41. by * read
|
|
E: 42.
|
|
|
|
Line 21 is a comment. Lines 22-25 identify this entry as a BDB database
|
|
configuration entry. Line 26 specifies the DN suffix
|
|
for queries to pass to this database. Line 27 specifies the directory
|
|
in which the database files will live.
|
|
|
|
Lines 28 and 29 identify the database {{super-user}} entry and associated
|
|
password. This entry is not subject to access control or size or
|
|
time limit restrictions.
|
|
|
|
Lines 30 through 32 indicate the indices to maintain for various
|
|
attributes.
|
|
|
|
Lines 33 through 41 specify access control for entries in this
|
|
database. As this is the first database, the controls also apply
|
|
to entries not held in any database (such as the Root DSE). For
|
|
all applicable entries, the {{EX:userPassword}} attribute is writable
|
|
by the entry itself and by the "admin" entry. It may be used for
|
|
authentication/authorization purposes, but is otherwise not readable.
|
|
All other attributes are writable by the entry and the "admin"
|
|
entry, but may be read by all users (authenticated or not).
|
|
|
|
Line 42 is a blank line, indicating the end of this entry.
|
|
|
|
The next section of the example configuration file defines another
|
|
BDB database. This one handles queries involving the
|
|
{{EX:dc=example,dc=net}} subtree but is managed by the same entity
|
|
as the first database. Note that without line 51, the read access
|
|
would be allowed due to the global access rule at line 19.
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E: 42. # BDB definition for example.net
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E: 43. dn: olcDatabase=bdb,cn=config
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E: 44. objectClass: olcDatabaseConfig
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E: 45. objectClass: olcBdbConfig
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E: 46. olcDatabase: bdb
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E: 47. olcSuffix: "dc=example,dc=net"
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E: 48. olcDbDirectory: /usr/local/var/openldap-data-net
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E: 49. olcRootDN: "cn=Manager,dc=example,dc=com"
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E: 50. olcDbIndex: objectClass eq
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E: 51. olcAccess: to * by users read
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