1 .TH SLAPD-LDAP 5 "RELEASEDATE" "OpenLDAP LDVERSION"
2 .\" Copyright 1998-2005 The OpenLDAP Foundation All Rights Reserved.
3 .\" Copying restrictions apply. See COPYRIGHT/LICENSE.
6 slapd-ldap \- LDAP backend to slapd
12 is not an actual database; instead it acts as a proxy to forward incoming
13 requests to another LDAP server. While processing requests it will also
14 chase referrals, so that referrals are fully processed instead of being
15 returned to the slapd client.
17 Sessions that explicitly Bind to the back-ldap database always create their
18 own private connection to the remote LDAP server. Anonymous sessions will
19 share a single anonymous connection to the remote server. For sessions bound
20 through other mechanisms, all sessions with the same DN will share the
21 same connection. This connection pooling strategy can enhance the proxy's
22 efficiency by reducing the overhead of repeatedly making/breaking multiple
25 The ldap database can also act as an information service, i.e. the identity
26 of locally authenticated clients is asserted to the remote server, possibly
27 in some modified form.
28 For this purpose, the proxy binds to the remote server with some
29 administrative identity, and, if required, authorizes the asserted identity.
33 The administrative identity of the proxy, on the remote server, must be
34 allowed to authorize by means of appropriate
43 options apply to the LDAP backend database.
44 That is, they must follow a "database ldap" line and come before any
45 subsequent "backend" or "database" lines.
46 Other database options are described in the
50 Note: It is strongly recommended to set
63 This is because operational attributes related to entry creation and
64 modification should not be used, as they could be passed to the target
65 servers, generating an error.
68 LDAP server to use. Multiple URIs can be set in in a single
70 argument, resulting in the underlying library automatically
71 call the first server of the list that responds, e.g.
73 \fBuri "ldap://host/ ldap://backup-host"\fP
75 The URI list is space- or comma-separated.
77 .\".B server <hostport>
78 .\"Obsolete option; same as `uri ldap://<hostport>/'.
80 .B acl-authcDN "<administrative DN for access control purposes>"
81 DN which is used to query the target server for acl checking; it
82 is supposed to have read access on the target server to attributes used
83 on the proxy for acl checking.
84 There is no risk of giving away such values; they are only used to
86 .B The acl-authcDN identity is by no means implicitly used by the proxy
87 .B when the client connects anonymously.
92 .B acl-passwd <password>
93 Password used with the
98 .B idassert-authcdn "<administrative DN for proxyAuthz purposes>"
99 DN which is used to propagate the client's identity to the target
100 by means of the proxyAuthz control when the client does not
101 belong to the DIT fragment that is being proxyied by back-ldap.
102 This is useful when operations performed by users bound to another
103 backend are propagated through back-ldap.
104 This requires the entry with
106 identity on the remote server to have
108 privileges on a wide set of DNs, e.g.
109 .BR authzTo=dn.subtree:"" ,
110 and the remote server to have
118 for details on these statements and for remarks and drawbacks about
121 .B idassert-passwd <password>
122 Password used with the proxy authzDN above.
124 .B idassert-mode <mode> [<flags>]
126 .I identity assertion
128 The supported modes are:
130 \fB<mode> := {legacy|anonymous|none|<id>|self}\fP
132 \fB<flags> := {override}\fP
134 \fB<id> := {u:<ID>|[dn:]<DN>}\fP
138 which implies that the proxy will bind as
140 and assert the client's identity when it is not anonymous.
141 Direct binds are always proxied.
142 The other modes imply that the proxy will always bind as
143 .IR idassert-authcdn ,
145 .BR idassert-authzFrom
146 rules (see below), in which case the operation will fail;
147 eventually, it will assert some other identity according to
149 Other identity assertion modes are
153 which respectively mean that the
160 which means that no proxyAuthz control will be used, so the
162 identity will be asserted.
163 Moreover, if a string prefixed with
169 that identity will be asserted.
170 Ths string is also treated as a DN if it is not prefixed
171 by any recognized type indicator. Whether or not the
173 prefix is present, the string must pass DN validation and normalization.
174 For all modes that require the use of the
176 control, on the remote server the proxy identity must have appropriate
178 permissions, or the asserted identities must have appropriate
180 permissions. Note, however, that the ID assertion feature is mostly
181 useful when the asserted identities do not exist on the remote server.
184 flag is used, identity assertion takes place even when the database
185 is authorizing for the identity of the client, i.e. after binding
186 with the provided identity, and thus authenticating it, the proxy
187 performs the identity assertion using the configured identity and
188 authentication method.
191 .B idassert-authzFrom <authz-regexp>
192 if defined, selects what
194 identities are authorized to exploit the identity assertion feature.
197 follows the rules defined for the
204 for details on the syntax of this field.
206 .B idassert-method <method> [<saslargs>]
207 where valid method values are
209 \fB<method> := {none|simple|sasl}\fP
211 \fB<saslargs> := [mech=<mech>] [realm=<realm>] [authcid=<authcid>] [cred=<cred>] [authz={native|proxyauthz}]\fP
215 extra parameters can be given as described above.
219 inhibits proxy authorization;
221 uses a SASL bind with the above parameters; if required,
223 is performed by means of native SASL mechanism, and no proxyAuthz
224 is used for subsequent operations.
228 Turns on proxying of the WhoAmI extended operation. If this option is
229 given, back-ldap will replace slapd's original WhoAmI routine with its
230 own. On slapd sessions that were authenticated by back-ldap, the WhoAmI
231 request will be forwarded to the remote LDAP server. Other sessions will
232 be handled by the local slapd, as before. This option is mainly useful
233 in conjunction with Proxy Authorization.
236 If this option is given, the client's bind credentials are remembered
237 for rebinds when chasing referrals.
239 .\".B suffixmassage <suffix> <massaged (remote) suffix>
240 .\"DNs ending with <suffix> in a request are changed to end with <remote
241 .\"suffix> before sending the request to the remote server, and <remote
242 .\"suffix> in the results are changed back to <suffix> before returning
243 .\"them to the client.
244 .\"The <suffix> field must be defined as a valid suffix
245 .\"for the current database.
247 .\".B map "{attribute | objectclass} [<local name> | *] {<foreign name> | *}"
248 .\"Map attribute names and object classes from the foreign server to
249 .\"different values on the local slapd.
250 .\"The reason is that some attributes might not be part of the local
251 .\"slapd's schema, some attribute names might be different but serve the
252 .\"same purpose, etc.
253 .\"If local or foreign name is `*', the name is preserved.
254 .\"If local name is omitted, the foreign name is removed.
255 .\"Unmapped names are preseved if both local and foreign name are `*',
256 .\"and removed if local name is omitted and foreign name is `*'.
259 .\"The rewrite options are described in the "REWRITING" section of the
260 .\".BR slapd-meta (5)
263 .B suffixmassage, map, rewrite*
264 These directives are no longer supported by back-ldap; their
265 functionality is now delegated to the
270 However, to ease update from existing configurations, back-ldap still
271 recognizes them and automatically instantiates the
273 overlay if available and not instantiated yet.
274 This behavior may change in the future.
276 .\"The following directives map the object class `groupOfNames' to
277 .\"the object class `groupOfUniqueNames' and the attribute type
278 .\"`member' to the attribute type `uniqueMember':
282 .\"map objectclass groupOfNames groupOfUniqueNames
283 .\"map attribute uniqueMember member
287 .\"This presents a limited attribute set from the foreign
292 .\"map attribute cn *
293 .\"map attribute sn *
294 .\"map attribute manager *
295 .\"map attribute description *
300 .\"These lines map cn, sn, manager, and description to themselves, and
301 .\"any other attribute gets "removed" from the object before it is sent
302 .\"to the client (or sent up to the LDAP server). This is obviously a
303 .\"simplistic example, but you get the point.
304 .SH PROXY CACHE OVERLAY
305 The proxy cache overlay
306 allows caching of LDAP search requests (queries) in a local database.
313 default slapd configuration file
317 .BR slapo\-pcache (5),
322 Howard Chu, with enhancements by Pierangelo Masarati