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: In early versions of back-ldap it was recommended to always 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.
66 The current implementation automatically sets ldapmod to off, so its use
67 is redundant and can be safely omitted.
70 LDAP server to use. Multiple URIs can be set in in a single
72 argument, resulting in the underlying library automatically
73 call the first server of the list that responds, e.g.
75 \fBuri "ldap://host/ ldap://backup-host"\fP
77 The URI list is space- or comma-separated.
79 .\".B server <hostport>
80 .\"Obsolete option; same as `uri ldap://<hostport>/'.
82 .B acl-authcDN "<administrative DN for access control purposes>"
83 DN which is used to query the target server for acl checking; it
84 is supposed to have read access on the target server to attributes used
85 on the proxy for acl checking.
86 There is no risk of giving away such values; they are only used to
88 .B The acl-authcDN identity is by no means implicitly used by the proxy
89 .B when the client connects anonymously.
94 .B acl-passwd <password>
95 Password used with the
100 .B idassert-authcdn "<administrative DN for proxyAuthz purposes>"
101 DN which is used to propagate the client's identity to the target
102 by means of the proxyAuthz control when the client does not
103 belong to the DIT fragment that is being proxyied by back-ldap.
104 This is useful when operations performed by users bound to another
105 backend are propagated through back-ldap.
106 This requires the entry with
108 identity on the remote server to have
110 privileges on a wide set of DNs, e.g.
111 .BR authzTo=dn.subtree:"" ,
112 and the remote server to have
120 for details on these statements and for remarks and drawbacks about
123 .B idassert-passwd <password>
124 Password used with the proxy authzDN above.
126 .B idassert-mode <mode> [<flags>]
128 .I identity assertion
130 The supported modes are:
132 \fB<mode> := {legacy|anonymous|none|<id>|self}\fP
134 \fB<flags> := {override}\fP
136 \fB<id> := {u:<ID>|[dn:]<DN>}\fP
140 which implies that the proxy will bind as
142 and assert the client's identity when it is not anonymous.
143 Direct binds are always proxied.
144 The other modes imply that the proxy will always bind as
145 .IR idassert-authcdn ,
147 .BR idassert-authzFrom
148 rules (see below), in which case the operation will fail;
149 eventually, it will assert some other identity according to
151 Other identity assertion modes are
155 which respectively mean that the
162 which means that no proxyAuthz control will be used, so the
164 identity will be asserted.
165 Moreover, if a string prefixed with
171 that identity will be asserted.
172 Ths string is also treated as a DN if it is not prefixed
173 by any recognized type indicator. Whether or not the
175 prefix is present, the string must pass DN validation and normalization.
176 For all modes that require the use of the
178 control, on the remote server the proxy identity must have appropriate
180 permissions, or the asserted identities must have appropriate
182 permissions. Note, however, that the ID assertion feature is mostly
183 useful when the asserted identities do not exist on the remote server.
186 flag is used, identity assertion takes place even when the database
187 is authorizing for the identity of the client, i.e. after binding
188 with the provided identity, and thus authenticating it, the proxy
189 performs the identity assertion using the configured identity and
190 authentication method.
193 .B idassert-authzFrom <authz-regexp>
194 if defined, selects what
196 identities are authorized to exploit the identity assertion feature.
199 follows the rules defined for the
206 for details on the syntax of this field.
208 .B idassert-method <method> [<saslargs>]
209 where valid method values are
211 \fB<method> := {none|simple|sasl}\fP
213 \fB<saslargs> := [mech=<mech>] [realm=<realm>] [authcid=<authcid>] [cred=<cred>] [authz={native|proxyauthz}]\fP
217 extra parameters can be given as described above.
221 inhibits proxy authorization;
223 uses a SASL bind with the above parameters; if required,
225 is performed by means of native SASL mechanism, and no proxyAuthz
226 is used for subsequent operations.
230 Turns on proxying of the WhoAmI extended operation. If this option is
231 given, back-ldap will replace slapd's original WhoAmI routine with its
232 own. On slapd sessions that were authenticated by back-ldap, the WhoAmI
233 request will be forwarded to the remote LDAP server. Other sessions will
234 be handled by the local slapd, as before. This option is mainly useful
235 in conjunction with Proxy Authorization.
238 If this option is given, the client's bind credentials are remembered
239 for rebinds when chasing referrals. Useful in conjunction with
240 \fBchase-referrals\fP, useless if \fBdont-chase-referrals\fP is set.
244 .B dont-chase-referrals
246 enable/disable automatic referral chasing, which is delegated to the
247 underlying libldap, with rebinding eventually performed if the
248 \fBrebind-as-user\fP directive is used. The default is to chase referrals.
256 execute the start TLS extended operation when the connection is initialized.
257 \fBtry-start-tls\fP continues operations if start TLS fails.
264 .\".B suffixmassage <suffix> <massaged (remote) suffix>
265 .\"DNs ending with <suffix> in a request are changed to end with <remote
266 .\"suffix> before sending the request to the remote server, and <remote
267 .\"suffix> in the results are changed back to <suffix> before returning
268 .\"them to the client.
269 .\"The <suffix> field must be defined as a valid suffix
270 .\"for the current database.
272 .\".B map "{attribute | objectclass} [<local name> | *] {<foreign name> | *}"
273 .\"Map attribute names and object classes from the foreign server to
274 .\"different values on the local slapd.
275 .\"The reason is that some attributes might not be part of the local
276 .\"slapd's schema, some attribute names might be different but serve the
277 .\"same purpose, etc.
278 .\"If local or foreign name is `*', the name is preserved.
279 .\"If local name is omitted, the foreign name is removed.
280 .\"Unmapped names are preseved if both local and foreign name are `*',
281 .\"and removed if local name is omitted and foreign name is `*'.
284 .\"The rewrite options are described in the "REWRITING" section of the
285 .\".BR slapd-meta (5)
288 .B suffixmassage, map, rewrite*
289 These directives are no longer supported by back-ldap; their
290 functionality is now delegated to the
295 However, to ease update from existing configurations, back-ldap still
296 recognizes them and automatically instantiates the
298 overlay if available and not instantiated yet.
299 This behavior may change in the future.
301 .\"The following directives map the object class `groupOfNames' to
302 .\"the object class `groupOfUniqueNames' and the attribute type
303 .\"`member' to the attribute type `uniqueMember':
307 .\"map objectclass groupOfNames groupOfUniqueNames
308 .\"map attribute uniqueMember member
312 .\"This presents a limited attribute set from the foreign
317 .\"map attribute cn *
318 .\"map attribute sn *
319 .\"map attribute manager *
320 .\"map attribute description *
325 .\"These lines map cn, sn, manager, and description to themselves, and
326 .\"any other attribute gets "removed" from the object before it is sent
327 .\"to the client (or sent up to the LDAP server). This is obviously a
328 .\"simplistic example, but you get the point.
329 .SH PROXY CACHE OVERLAY
330 The proxy cache overlay
331 allows caching of LDAP search requests (queries) in a local database.
338 default slapd configuration file
342 .BR slapo\-pcache (5),
347 Howard Chu, with enhancements by Pierangelo Masarati
projects / openldap / blob