mirror of
https://git.openldap.org/openldap/openldap.git
synced 2024-12-27 03:20:22 +08:00
350 lines
12 KiB
XML
350 lines
12 KiB
XML
<?xml version="1.0" encoding="UTF-8"?>
|
|
|
|
<!DOCTYPE rfc SYSTEM "rfc2629.dtd" [
|
|
<!ENTITY rfc2119 PUBLIC ''
|
|
'http://xml.resource.org/public/rfc/bibxml/reference.RFC.2119.xml'>
|
|
<!ENTITY rfc4510 PUBLIC ''
|
|
'http://xml.resource.org/public/rfc/bibxml/reference.RFC.4510.xml'>
|
|
<!ENTITY rfc4511 PUBLIC ''
|
|
'http://xml.resource.org/public/rfc/bibxml/reference.RFC.4511.xml'>
|
|
<!ENTITY rfc4512 PUBLIC ''
|
|
'http://xml.resource.org/public/rfc/bibxml/reference.RFC.4512.xml'>
|
|
<!ENTITY rfc4517 PUBLIC ''
|
|
'http://xml.resource.org/public/rfc/bibxml/reference.RFC.4517.xml'>
|
|
]>
|
|
|
|
<!-- $OpenLDAP$ -->
|
|
|
|
<rfc category="std" ipr="full3978" docName="draft-masarati-ldap-deref-00.txt">
|
|
|
|
<?xml-stylesheet type='text/xsl' href='rfc2629.xslt' ?>
|
|
|
|
<?rfc toc="yes" ?>
|
|
<?rfc symrefs="yes" ?>
|
|
<?rfc sortrefs="yes"?>
|
|
<?rfc iprnotified="no" ?>
|
|
<?rfc strict="yes" ?>
|
|
|
|
<front>
|
|
<title abbrev='LDAP Deref'>LDAP Dereference Control</title>
|
|
<author initials='P.' surname="Masarati" fullname='Pierangelo Masarati'>
|
|
<organization abbrev='Politecnico di Milano'>
|
|
Politecnico di Milano
|
|
</organization>
|
|
<address>
|
|
<postal>
|
|
<street>Dipartimento di Ingegneria Aerospaziale</street>
|
|
<street>via La Masa 34</street>
|
|
<city>Milano</city>
|
|
<code>20156</code>
|
|
<country>IT</country>
|
|
</postal>
|
|
<phone>+39 02 2399 8309</phone>
|
|
<facsimile>+39 02 2399 8334</facsimile>
|
|
<email>ando@OpenLDAP.org</email>
|
|
<uri>http://www.aero.polimi.it/masarati/</uri>
|
|
</address>
|
|
</author>
|
|
<author initials="H.Y." surname="Chu" fullname="Howard Y. Chu">
|
|
<organization abbrev="Symas Corp.">
|
|
Symas Corporation
|
|
</organization>
|
|
<address>
|
|
<postal>
|
|
<street>18740 Oxnard St., Suite 313A</street>
|
|
<city>Tarzana</city>
|
|
<region>California</region>
|
|
<code>91356</code>
|
|
<country>USA</country>
|
|
</postal>
|
|
<phone>+1 818 757-7087</phone>
|
|
<email>hyc@symas.com</email>
|
|
<uri>http://www.symas.com/</uri>
|
|
</address>
|
|
</author>
|
|
<date/>
|
|
<abstract>
|
|
<t>
|
|
This document describes the Dereference Control for LDAP.
|
|
This control is intended to provide a concise means to collect
|
|
extra information related to cross-links present in entries
|
|
returned as part of search responses.
|
|
</t>
|
|
</abstract>
|
|
</front>
|
|
|
|
<middle>
|
|
<section title="Background and Intended Use">
|
|
<t>
|
|
Cross-links between entries are often used to describe relationships
|
|
between entries.
|
|
To exploit the uniqueness of entries naming, these links are usually
|
|
represented by the distinguished name (DN) of the linked entries.
|
|
</t>
|
|
|
|
<t>
|
|
In many cases, DUAs need to collect information about linked entries.
|
|
This requires to explicitly dereference each linked entry in order to
|
|
collect the desired attributes, resulting in the need to perform a
|
|
specific sequence of search operations, using the links as search base,
|
|
with a SearchRequest.scope of baseObject <xref target="RFC4511" />.
|
|
</t>
|
|
|
|
<t>
|
|
This document describes a LDAP Control <xref target="RFC4511" />
|
|
that allows a DUA to request the DSA to return specific attributes
|
|
of linked entries along with the link, under the assumption that
|
|
this operation can be performed by the DSA in a more efficient manner
|
|
than the DUA would itself by performing the complete sequence
|
|
of required search operations.
|
|
</t>
|
|
|
|
<t>
|
|
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL",
|
|
"SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY",
|
|
and "OPTIONAL" in this document are to be interpreted as
|
|
described in <xref target="RFC2119" />.
|
|
</t>
|
|
</section>
|
|
|
|
<section title="The LDAP Dereference Control">
|
|
<section title="Control Semantics">
|
|
<t>
|
|
This control allows specifying a dereference attribute and a set
|
|
of attributes to be dereferenced, as illustrated
|
|
in <xref target="control_request" />.
|
|
The dereference attribute's syntax MUST be 1.3.6.1.4.1.1466.115.121.1.12
|
|
(DN) <xref target="RFC4517" />.
|
|
Each value of the dereference attribute in a SearchResultEntry SHOULD
|
|
result in dereferencing the corresponding entry, collecting the values
|
|
of the attributes to be dereferenced, and returning them as part
|
|
of the control value in the SearchResultEntry response, in the format
|
|
detailed in <xref target="control_response" />.
|
|
</t>
|
|
|
|
<t>
|
|
The control value may contain dereference attribute values without any
|
|
dereferenced attribute values, as detailed in
|
|
<xref target="control_response" />.
|
|
The control semantics does not specify whether this is a consequence
|
|
of a dangling link or of the application of access restrictions
|
|
on the values of the attributes to be dereferenced.
|
|
</t>
|
|
|
|
<t>
|
|
Attribute description hierarchy <xref target="RFC4512" /> SHALL NOT
|
|
be exploited when collecting the values of the attributes
|
|
to be dereferenced.
|
|
On the contrary, all of the attribute descriptions in an attribute
|
|
hierarchy SHOULD be treated as distinct and unrelated descriptions.
|
|
</t>
|
|
|
|
<t>
|
|
This control is only appropriate for the search operation
|
|
<xref target="RFC4511" />.
|
|
</t>
|
|
|
|
<t>
|
|
The semantics of the criticality field are specified in
|
|
<xref target="RFC4511" />.
|
|
In detail, the criticality of the control determines whether the control
|
|
will or will not be used, and if it will not be used, whether the operation
|
|
will continue without returning the control in the response, or fail,
|
|
returning unavailableCriticalExtension.
|
|
If the control is appropriate for an operation and, for any reason,
|
|
it cannot be applied in its entirety to a single SearchResultEntry response,
|
|
it MUST NOT be applied to that specific SearchResultEntry response,
|
|
without affecting its application to any subsequent SearchResultEntry
|
|
response.
|
|
</t>
|
|
|
|
<t>
|
|
Servers implementing this technical specification SHOULD publish
|
|
the object identifier deref-oid (IANA assigned;
|
|
see <xref target="iana_considerations" />) as a value
|
|
of the 'supportedControl' attribute <xref target="RFC4512" />
|
|
in their root DSE.
|
|
</t>
|
|
|
|
<t>
|
|
This control is totally unrelated to alias dereferencing
|
|
<xref target="RFC4511" />.
|
|
</t>
|
|
</section>
|
|
|
|
<section anchor="control_request" title="Control Request">
|
|
<figure>
|
|
<preamble>
|
|
The control type is deref-oid (IANA assigned;
|
|
see <xref target="iana_considerations" />).
|
|
The specification of the Dereference Control request is:
|
|
</preamble>
|
|
<artwork>
|
|
controlValue ::= SEQUENCE OF derefSpec DerefSpec
|
|
|
|
DerefSpec ::= SEQUENCE {
|
|
derefAttr attributeDescription, ; with DN syntax
|
|
attributes AttributeList }
|
|
|
|
AttributeList ::= SEQUENCE OF attr AttributeDescription
|
|
</artwork>
|
|
<postamble>
|
|
Each derefSpec.derefAttr MUST be unique within controlValue.
|
|
</postamble>
|
|
</figure>
|
|
</section>
|
|
|
|
<section anchor="control_response" title="Control Response">
|
|
<figure>
|
|
<preamble>
|
|
The control type is deref-oid (IANA assigned;
|
|
see <xref target="iana_considerations" />).
|
|
The specification of the Dereference Control response is:
|
|
</preamble>
|
|
<artwork>
|
|
controlValue ::= SEQUENCE OF derefRes DerefRes
|
|
|
|
DerefRes ::= SEQUENCE {
|
|
derefAttr AttributeDescription,
|
|
derefVal LDAPDN,
|
|
attrVals [0] PartialAttributeList OPTIONAL }
|
|
|
|
PartialAttributeList ::= SEQUENCE OF
|
|
partialAttribute PartialAttribute
|
|
</artwork>
|
|
</figure>
|
|
<figure>
|
|
<preamble>
|
|
PartialAttribute is defined in <xref target="RFC4511" />;
|
|
the definition is reported here for clarity:
|
|
</preamble>
|
|
<artwork>
|
|
PartialAttribute ::= SEQUENCE {
|
|
type AttributeDescription,
|
|
vals SET OF value AttributeValue }
|
|
</artwork>
|
|
<postamble>
|
|
If partialAttribute.vals is empty, the corresponding partialAttribute
|
|
is omitted.
|
|
If all partialAttribute.vals in attrVals are empty, that derefRes.attrVals
|
|
is omitted.
|
|
</postamble>
|
|
</figure>
|
|
</section>
|
|
</section>
|
|
|
|
<section title="Examples">
|
|
<figure>
|
|
<preamble>
|
|
Given these entries:
|
|
</preamble>
|
|
<artwork>
|
|
dn: cn=Howard Chu,ou=people,dc=example,dc=org
|
|
objectClass: inetOrgPerson
|
|
cn: Howard Chu
|
|
sn: Chu
|
|
uid: hyc
|
|
|
|
dn: cn=Pierangelo Masarati,ou=people,dc=example,dc=org
|
|
objectClass: inetOrgPerson
|
|
cn: Pierangelo Masarati
|
|
sn: Masarati
|
|
uid: ando
|
|
|
|
dn: cn=Test Group,ou=groups,dc=example,dc=org
|
|
objectClass: groupOfNames
|
|
cn: Test Group
|
|
member: cn=Howard Chu,ou=people,dc=example,dc=org
|
|
member: cn=Pierangelo Masarati,ou=people,dc=example,dc=org
|
|
</artwork>
|
|
</figure>
|
|
<figure>
|
|
<preamble>
|
|
A search could be performed with a Dereference request control value
|
|
specified as
|
|
</preamble>
|
|
<artwork>
|
|
{ member, uid }
|
|
</artwork>
|
|
</figure>
|
|
<figure>
|
|
<preamble>
|
|
and the "cn=Test Group" entry would be returned with the response control
|
|
value
|
|
</preamble>
|
|
<artwork>
|
|
{ { member, cn=Howard Chu,ou=people,dc=example,dc=org,
|
|
{ { uid, [hyc] } } },
|
|
{ member, cn=Pierangelo Masarati,ou=people,dc=example,dc=org,
|
|
{ { uid, [ando] } } } }
|
|
</artwork>
|
|
</figure>
|
|
</section>
|
|
|
|
<section title="Implementation Notes">
|
|
<t>
|
|
This LDAP extension is currently implemented in OpenLDAP software
|
|
using the temporary OID 1.3.6.1.4.1.4203.666.5.16 under OpenLDAP's
|
|
experimental OID arc.
|
|
</t>
|
|
</section>
|
|
|
|
<section title="Security Considerations">
|
|
<t>
|
|
The control result MUST NOT disclose information the client's identity
|
|
could not have accessed by performing the related search operations.
|
|
The presence of a derefRes.derefVal in the response control, with
|
|
no derefRes.attrVals, does not imply neither the existence of nor any
|
|
access privilege to the corresponding entry.
|
|
It is merely a consequence of the read access the client's identity has
|
|
on the corresponding value of the derefRes.derefAttr that would be returned
|
|
as part of the attributes of a SearchResultEntry response
|
|
<xref target="RFC4511" />.
|
|
</t>
|
|
<t>
|
|
Security considerations described in documents listed in
|
|
<xref target="RFC4510" /> apply.
|
|
</t>
|
|
</section>
|
|
|
|
<section anchor="iana_considerations" title="IANA Considerations">
|
|
<section title="Object Identifier Registration">
|
|
<figure>
|
|
<preamble>
|
|
It is requested that IANA register upon Standards Action an LDAP
|
|
Object Identifier for use in this technical specification.
|
|
</preamble>
|
|
<artwork>
|
|
Subject: Request for LDAP OID Registration
|
|
Person & email address to contact for further information:
|
|
Pierangelo Masarati <ando@OpenLDAP.org>
|
|
Specification: (I-D)
|
|
Author/Change Controller: IESG
|
|
Comments:
|
|
Identifies the LDAP Dereference Control request
|
|
and response
|
|
</artwork>
|
|
</figure>
|
|
</section>
|
|
</section>
|
|
|
|
<section title="Acknowledgments">
|
|
<t>
|
|
TBD
|
|
</t>
|
|
</section>
|
|
</middle>
|
|
|
|
<back>
|
|
<references title='Normative References'>
|
|
&rfc2119;
|
|
&rfc4510;
|
|
&rfc4511;
|
|
&rfc4512;
|
|
&rfc4517;
|
|
</references>
|
|
|
|
</back>
|
|
|
|
</rfc>
|