openldap/doc/drafts/draft-legg-ldap-binary-xx.txt
2004-08-27 18:41:02 +00:00

449 lines
17 KiB
Plaintext
Raw Blame History

This file contains invisible Unicode characters

This file contains invisible Unicode characters that are indistinguishable to humans but may be processed differently by a computer. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

INTERNET-DRAFT S. Legg
draft-legg-ldap-binary-01.txt Adacel Technologies
Intended Category: Standards Track 16 June 2004
Updates: RFC 2251bis
Lightweight Directory Access Protocol (LDAP):
The Binary Encoding Option
Copyright (C) The Internet Society (2004). All Rights Reserved.
Status of this Memo
This document is an Internet-Draft and is in full conformance with
all provisions of Section 10 of RFC2026.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF), its areas, and its working groups. Note that
other groups may also distribute working documents as
Internet-Drafts.
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress".
The list of current Internet-Drafts can be accessed at
http://www.ietf.org/ietf/1id-abstracts.txt
The list of Internet-Draft Shadow Directories can be accessed at
http://www.ietf.org/shadow.html.
This document is intended to be, after appropriate review and
revision, submitted to the RFC Editor as a Standard Track document.
Distribution of this document is unlimited. Technical discussion of
this document should take place on the IETF LDAP Revision Working
Group (LDAPbis) mailing list <ietf-ldapbis@openldap.org>. Please
send editorial comments directly to the editor
<steven.legg@adacel.com.au>.
This Internet-Draft expires on 16 December 2004.
Abstract
Each attribute stored in a Lightweight Directory Access Protocol
(LDAP) directory has a defined syntax (i.e., data type). A syntax
Legg Expires 16 December 2004 [Page 1]
INTERNET-DRAFT LDAP: The Binary Encoding Option June 16, 2004
definition specifies how attribute values conforming to the syntax
are normally represented when transferred in LDAP operations. This
representation is referred to as the LDAP-specific encoding to
distinguish it from other methods of encoding attribute values. This
document defines an attribute option, the binary option, which can be
used to specify that the associated attribute values are instead
encoded according to the Basic Encoding Rules (BER) used by X.500
directories.
Legg Expires 16 December 2004 [Page 2]
INTERNET-DRAFT LDAP: The Binary Encoding Option June 16, 2004
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Conventions. . . . . . . . . . . . . . . . . . . . . . . . . . 4
3. The binary Option. . . . . . . . . . . . . . . . . . . . . . . 4
4. Syntaxes Requiring Binary Transfer . . . . . . . . . . . . . . 4
5. Attributes Returned in a Search. . . . . . . . . . . . . . . . 5
6. All User Attributes. . . . . . . . . . . . . . . . . . . . . . 5
7. Conflicting Requests . . . . . . . . . . . . . . . . . . . . . 6
8. Security Considerations. . . . . . . . . . . . . . . . . . . . 6
9. IANA Considerations. . . . . . . . . . . . . . . . . . . . . . 6
10. References . . . . . . . . . . . . . . . . . . . . . . . . . . 6
10.1. Normative References. . . . . . . . . . . . . . . . . . 6
10.2. Informative References. . . . . . . . . . . . . . . . . 7
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . . 7
Full Copyright Statement . . . . . . . . . . . . . . . . . . . . . 8
1. Introduction
Each attribute stored in a Lightweight Directory Access Protocol
(LDAP) directory [ROADMAP] has a defined syntax (i.e., data type)
which constrains the structure and format of its values.
The description of each syntax [SYNTAX] specifies how attribute or
assertion values [MODELS] conforming to the syntax are normally
represented when transferred in LDAP operations [PROT]. This
representation is referred to as the LDAP-specific encoding to
distinguish it from other methods of encoding attribute values.
This document defines an attribute option, the binary option, which
can be used in an attribute description [MODELS] in an LDAP operation
to specify that the associated attribute values or assertion value
are, or are requested to be, encoded according to the Basic Encoding
Rules (BER) [BER] as used by X.500 [X500] directories, instead of the
usual LDAP-specific encoding.
The binary option was originally defined in RFC 2251 [RFC2251]. The
LDAP technical specification [ROADMAP] has obsoleted the previously
defined LDAP technical specification [RFC3377], which included RFC
2251. However the binary option was not included in the newer LDAP
technical specification due to a lack of consistency in its
implementation. This document reintroduces the binary option.
However, except for the case of certain attribute syntaxes whose
values are required to BER encoded, no attempt is made here to
eliminate the known consistency problems. Rather the focus is on
capturing current behaviours. A more thorough solution is left for a
future specification.
Legg Expires 16 December 2004 [Page 3]
INTERNET-DRAFT LDAP: The Binary Encoding Option June 16, 2004
2. Conventions
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 BCP 14, RFC 2119
[KEYWORD].
3. The binary Option
The binary option is indicated with the attribute option string
"binary" in an attribute description. Note that, like all attribute
options, the string representing the binary option is case
insensitive.
In terms of the protocol [PROT], the binary option specifies that the
contents octets of the associated AttributeValue or AssertionValue
OCTET STRING are a complete BER encoding of the relevant value.
Where the binary option is present in an attribute description the
associated attribute values or assertion value MUST be BER encoded.
Note that it is possible for a syntax to be defined such that its
LDAP-specific encoding is exactly the same as its BER encoding.
The binary option is not a tagging option [MODELS] so the presence of
the binary option does not specify an attribute subtype. An
attribute description containing the binary option references exactly
the same attribute as the same attribute description without the
binary option. The supertype/subtype relationships of attributes
with tagging options are not altered in any way by the presence or
absence of the binary option.
An attribute description SHALL be treated as unrecognized if it
contains the binary option and the syntax of the attribute does not
have an associated ASN.1 type [SYNTAX], or the BER encoding of that
type is not supported.
The presence or absence of the binary option only affects the
transfer of attribute and assertion values in protocol; servers store
any particular attribute value in a single format of their choosing.
4. Syntaxes Requiring Binary Transfer
Certain syntaxes are required to be transferred in the BER encoded
form. These syntaxes are said to have a binary transfer requirement.
The Certificate, Certificate List, Certificate Pair and Supported
Algorithm syntaxes [PKI] are examples of syntaxes with a binary
transfer requirement. These syntaxes also have an additional
requirement that the exact BER encoding must be preserved. Note that
Legg Expires 16 December 2004 [Page 4]
INTERNET-DRAFT LDAP: The Binary Encoding Option June 16, 2004
this is a property of the syntaxes themselves, and not a property of
the binary option.
5. Attributes Returned in a Search
An LDAP search request [PROT] contains a list of the attributes (the
requested attributes list) to be returned from each entry matching
the search filter. An attribute description in the requested
attributes list also implicitly requests all subtypes of the
attribute type in the attribute description, whether through
attribute subtyping or attribute tagging option subtyping [MODELS].
The requested attributes list MAY contain attribute descriptions with
the binary option, but MUST NOT contain two attribute descriptions
with the same attribute type and the same tagging options (even if
only one of them has the binary option). The binary option in an
attribute description in the requested attributes list implicitly
applies to all the subtypes of the attribute type in the attribute
description (however, see Section 7).
Attributes of a syntax with the binary transfer requirement SHALL be
returned in the binary form, i.e., with the binary option in the
attribute description and the associated attribute values BER
encoded, regardless of whether the binary option was present in the
request (for the attribute or for one of its supertypes).
Attributes of a syntax without the binary transfer requirement SHOULD
be returned in the form explicitly requested. That is, if the
attribute description in the requested attributes list contains the
binary option then the corresponding attribute in the result SHOULD
be in the binary form. If the attribute description in the request
does not contain the binary option then the corresponding attribute
in the result SHOULD NOT be in the binary form. A server MAY omit an
attribute from the result if it does not support the requested
encoding.
Regardless of the encoding chosen, a particular attribute value is
returned at most once.
6. All User Attributes
If the list of attributes in a search request is empty, or contains
the special attribute description string "*", then all user
attributes are requested to be returned.
Attributes of a syntax with the binary transfer requirement SHALL be
returned in the binary form.
Legg Expires 16 December 2004 [Page 5]
INTERNET-DRAFT LDAP: The Binary Encoding Option June 16, 2004
Attributes of a syntax without the binary transfer requirement and
having a defined LDAP-specific encoding SHOULD NOT be returned in the
binary form.
Attributes of a syntax without the binary transfer requirement and
without a defined LDAP-specific encoding may be returned in the
binary form or omitted from the result.
7. Conflicting Requests
A particular attribute could be explicitly requested by an attribute
description and/or implicitly requested by the attribute descriptions
of one or more of its supertypes, or by the special attribute
description string "*". If the binary option is not present in all
these attribute descriptions, nor absent in all these attribute
descriptions, then the server is free to choose whether to return the
attribute in the binary form.
8. Security Considerations
When interpreting security-sensitive fields, and in particular fields
used to grant or deny access, implementations MUST ensure that any
matching rule comparisons are done on the underlying abstract value,
regardless of the particular encoding used.
9. IANA Considerations
The Internet Assigned Numbers Authority (IANA) is requested to update
the LDAP attribute description option registry [BCP64] as indicated
by the following template:
Subject: Request for
LDAP Attribute Description Option Registration
Option Name: binary
Family of Options: NO
Person & email address to contact for further information:
Steven Legg <steven.legg@adacel.com.au>
Specification: RFC XXXX
Author/Change Controller: IESG
Comments: The existing registration for "binary"
should be updated to refer to RFC XXXX.
10. References
10.1. Normative References
[KEYWORD] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
Legg Expires 16 December 2004 [Page 6]
INTERNET-DRAFT LDAP: The Binary Encoding Option June 16, 2004
[BCP64] Zeilenga, K., "Internet Assigned Numbers Authority (IANA)
Considerations for the Lightweight Directory Access
Protcol (LDAP)", BCP 64, RFC 3383, September 2002.
[ROADMAP] Zeilenga, K., "Lightweight Directory Access Protocol
(LDAP): Technical Specification Road Map",
draft-ietf-ldapbis-roadmap-xx.txt, a work in progress,
June 2004.
[MODELS] Zeilenga, K., "LDAP: Directory Information Models",
draft-ietf-ldapbis-models-xx.txt, a work in progress, June
2004.
[PROT] Sermersheim, J., "LDAP: The Protocol",
draft-ietf-ldapbis-protocol-xx.txt, a work in progress,
May 2004.
[SYNTAX] Legg, S. and K. Dally, "Lightweight Directory Access
Protocol (LDAP): Syntaxes and Matching Rules",
draft-ietf-ldapbis-syntaxes-xx.txt, a work in progress,
May 2004.
[PKI] Chadwick, D. and S. Legg, "Internet X.509 Public Key
Infrastructure Additional LDAP Schema for PKIs and PMIs",
draft-pkix-ldap-schema-xx.txt, a work in progress, April
2002.
[BER] ITU-T Recommendation X.690 (07/02) | ISO/IEC 8825-1,
Information Technology - ASN.1 encoding rules:
Specification of Basic Encoding Rules (BER), Canonical
Encoding Rules (CER) and Distinguished Encoding Rules
(DER).
10.2. Informative References
[RFC2251] Wahl, M., Howes, T. and S. Kille, "Lightweight Directory
Access Protocol (v3)", RFC 2251, December 1997.
[RFC3377] Hodges, J. and R. Morgan, "Lightweight Directory Access
Protocol (v3): Technical Specification", RFC 3377,
September 2002.
[X500] ITU-T Recommendation X.500 (1993) | ISO/IEC 9594-1:1994,
"Information Technology - Open Systems Interconnection -
The Directory: Overview of concepts, models and services".
Author's Address
Legg Expires 16 December 2004 [Page 7]
INTERNET-DRAFT LDAP: The Binary Encoding Option June 16, 2004
Steven Legg
Adacel Technologies Ltd.
250 Bay Street
Brighton, Victoria 3186
AUSTRALIA
Phone: +61 3 8530 7710
Fax: +61 3 8530 7888
Email: steven.legg@adacel.com.au
Full Copyright Statement
Copyright (C) The Internet Society (2004). This document is subject
to the rights, licenses and restrictions contained in BCP 78, and
except as set forth therein, the authors retain all their rights.
This document and the information contained herein are provided on an
"AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS
OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY AND THE INTERNET
ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED,
INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE
INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED
WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
Intellectual Property
The IETF takes no position regarding the validity or scope of any
Intellectual Property Rights or other rights that might be claimed to
pertain to the implementation or use of the technology described in
this document or the extent to which any license under such rights
might or might not be available; nor does it represent that it has
made any independent effort to identify any such rights. Information
on the procedures with respect to rights in RFC documents can be
found in BCP 78 and BCP 79.
Copies of IPR disclosures made to the IETF Secretariat and any
assurances of licenses to be made available, or the result of an
attempt made to obtain a general license or permission for the use of
such proprietary rights by implementers or users of this
specification can be obtained from the IETF on-line IPR repository at
http://www.ietf.org/ipr.
The IETF invites any interested party to bring to its attention any
copyrights, patents or patent applications, or other proprietary
rights that may cover technology that may be required to implement
this standard. Please address the information to the IETF at
ietf-ipr@ietf.org.
Legg Expires 16 December 2004 [Page 8]