Internet DRAFT - draft-bormann-core-target-attr
draft-bormann-core-target-attr
CoRE Working group C. Bormann
Internet-Draft Universität Bremen TZI
Intended status: Informational 6 November 2022
Expires: 10 May 2023
CoRE Target Attribute Registry
draft-bormann-core-target-attr-01
Abstract
The Constrained RESTful Environments (CoRE) specifications apply Web
technologies to constrained environments. One important such
technology is Web Linking [RFC8288], which CoRE uses as the basis for
a number of discovery protocols, such as the Link Format [RFC6690] in
CoAP's Resource Discovery Protocol (Section 7 of [RFC7252]) and the
Resource Directory [RFC9176].
Web Links can have Target Attributes, the names of which are not
generally coordinated by the Web Linking specification (Section 2.2
of [RFC8288]). This short note introduces an IANA registry for
coordinating names of Target Attributes when used in Constrained
RESTful Environments.
About This Document
This note is to be removed before publishing as an RFC.
Status information for this document may be found at
https://datatracker.ietf.org/doc/draft-bormann-core-target-attr/.
Discussion of this document takes place on the core Working Group
mailing list (mailto:core@ietf.org), which is archived at
https://mailarchive.ietf.org/arch/browse/core/. Subscribe at
https://www.ietf.org/mailman/listinfo/core/.
Source for this draft and an issue tracker can be found at
https://github.com/cabo/core-target-attr.
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet-
Drafts is at https://datatracker.ietf.org/drafts/current/.
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Internet-Drafts are draft documents valid for a maximum of six months
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This Internet-Draft will expire on 10 May 2023.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 3
2. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 3
3. Security considerations . . . . . . . . . . . . . . . . . . . 8
4. References . . . . . . . . . . . . . . . . . . . . . . . . . 8
4.1. Normative References . . . . . . . . . . . . . . . . . . 8
4.2. Informative References . . . . . . . . . . . . . . . . . 9
Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . 10
Contributors . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 10
1. Introduction
(Please see abstract.)
The original Web Linking specification Section 3 of [RFC5988] did not
attempt to coordinate names of target attributes except for providing
common target attributes for use in the Link HTTP header. The
current revision of that specification clarifies (Section 2.2 of
[RFC8288]):
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| This specification does not attempt to coordinate the name of
| target attributes, their cardinality, or use. Those creating and
| maintaining serialisations SHOULD coordinate their target
| attributes to avoid conflicts in semantics or syntax and MAY
| define their own registries of target attributes.
This short note introduces an IANA registry for coordinating names of
Target Attributes when used in Constrained RESTful Environments.
With a registry now available, registration of target attributes is
strongly encouraged. The incentive is that an unregistered attribute
name might be registered with a different meaning at any time. (See
also Section 2, Paragraph 2.)
1.1. Terminology
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in
BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all
capitals, as shown here.
2. IANA Considerations
This specification defines a new sub-registry for Target Attributes
in the CoRE Parameters registry [IANA.core-parameters], with the
policy "expert review" (Section 4.5 of [BCP26]).
The expert is instructed to be frugal in the allocation of very short
target attribute names, keeping them in reserve for applications that
are likely to enjoy wide use and can make good use of their
shortness. The expert is also instructed to direct the registrant to
provide a specification (Section 4.6 of [BCP26]), but can make
exceptions, for instance when a specification is not available at the
time of registration but is likely forthcoming. If the expert
becomes aware of target attributes that are deployed and in use, they
may also initiate a registration on their own if they deem such a
registration can avert potential future collisions.
Each entry in the registry must include:
Attribute Name:
a lower case ASCII [STD90] string that starts with a letter and
can contain digits and hyphen-minus characters afterwards
([a-z][-a-z0-9]*). (Note that [RFC8288] requires target attribute
names to be interpreted in a case-insensitive way; the restriction
to lower case here ensures that they are registered in a
predictable form).
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Brief description:
a brief description
Change Controller:
(see Section 2.3 of [BCP26])
Reference:
a reference document that provides a description of the target
attribute, including the semantics for when the target attribute
appears more than once in a link.
Initial entries in this sub-registry are as listed in Table 1:
+===============+==============+==========+==================================+
|Attribute Name |Brief |Change |Reference |
| |description |Controller| |
+===============+==============+==========+==================================+
|href |reserved (not |IESG |[RFC6690] |
| |useful as | | |
| |target | | |
| |attribute | | |
| |name) | | |
+---------------+--------------+----------+----------------------------------+
|anchor |reserved (not |IESG |[RFC6690] |
| |useful as | | |
| |target | | |
| |attribute | | |
| |name) | | |
+---------------+--------------+----------+----------------------------------+
|rel |reserved (not |IESG |[RFC6690] |
| |useful as | | |
| |target | | |
| |attribute | | |
| |name) | | |
+---------------+--------------+----------+----------------------------------+
|rev |reserved (not |IESG |[RFC6690] |
| |useful as | | |
| |target | | |
| |attribute | | |
| |name) | | |
+---------------+--------------+----------+----------------------------------+
|hreflang |(Web Linking) |IESG |[RFC8288] |
+---------------+--------------+----------+----------------------------------+
|media |(Web Linking) |IESG |[RFC8288] |
+---------------+--------------+----------+----------------------------------+
|title |(Web Linking) |IESG |[RFC8288] |
+---------------+--------------+----------+----------------------------------+
|type |(Web Linking) |IESG |[RFC8288] |
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+---------------+--------------+----------+----------------------------------+
|rt |resource type |IESG |Section 3.1 of [RFC6690] |
+---------------+--------------+----------+----------------------------------+
|if |interface |IESG |Section 3.2 of [RFC6690] |
| |description | | |
+---------------+--------------+----------+----------------------------------+
|sz |maximum size |IESG |Section 3.3 of [RFC6690] |
| |estimate | | |
+---------------+--------------+----------+----------------------------------+
|ct |Content-Format|IESG |Section 7.2.1 of [RFC7252] |
| |hint | | |
+---------------+--------------+----------+----------------------------------+
|obs |observable |IESG |Section 6 of [RFC7641] |
| |resource | | |
+---------------+--------------+----------+----------------------------------+
|hct |HTTP-CoAP URI |IESG |Section 5 of [RFC8075] |
| |mapping | | |
| |template | | |
+---------------+--------------+----------+----------------------------------+
|osc |hint: resource|IESG |Section 9 of [RFC8613] |
| |only | | |
| |accessible | | |
| |using OSCORE | | |
+---------------+--------------+----------+----------------------------------+
|method |A supported |IESG |Section 6 of |
| |authentication| |[I-D.ietf-core-oscore-edhoc] |
| |method for | | |
| |EDHOC | | |
+---------------+--------------+----------+----------------------------------+
|csuite |A supported |IESG |Section 6 of |
| |cipher suite | |[I-D.ietf-core-oscore-edhoc] |
| |for EDHOC | | |
+---------------+--------------+----------+----------------------------------+
|cred_t |A supported |IESG |Section 6 of |
| |type of | |[I-D.ietf-core-oscore-edhoc] |
| |authentication| | |
| |credential for| | |
| |EDHOC | | |
+---------------+--------------+----------+----------------------------------+
|idcred_t |A supported |IESG |Section 6 of |
| |type of | |[I-D.ietf-core-oscore-edhoc] |
| |authentication| | |
| |credential | | |
| |identifier for| | |
| |EDHOC | | |
+---------------+--------------+----------+----------------------------------+
|ead_1 |A supported |IESG |Section 6 of |
| |EDHOC EAD_1 | |[I-D.ietf-core-oscore-edhoc] |
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| |item | | |
+---------------+--------------+----------+----------------------------------+
|ead_2 |A supported |IESG |Section 6 of |
| |EDHOC EAD_2 | |[I-D.ietf-core-oscore-edhoc] |
| |item | | |
+---------------+--------------+----------+----------------------------------+
|ead_3 |A supported |IESG |Section 6 of |
| |EDHOC EAD_3 | |[I-D.ietf-core-oscore-edhoc] |
| |item | | |
+---------------+--------------+----------+----------------------------------+
|ead_4 |A supported |IESG |Section 6 of |
| |EDHOC EAD_4 | |[I-D.ietf-core-oscore-edhoc] |
| |item | | |
+---------------+--------------+----------+----------------------------------+
|comb_req |Hint: support |IESG |Section 6 of |
| |for the | |[I-D.ietf-core-oscore-edhoc] |
| |EDHOC+OSCORE | | |
| |request | | |
+---------------+--------------+----------+----------------------------------+
|sec-gp |Name of the |IESG |Section 2.1 of |
| |security group| |[I-D.tiloca-core-oscore-discovery]|
| |that can be | | |
| |joined through| | |
| |this resource | | |
+---------------+--------------+----------+----------------------------------+
|app-gp |Name of an |IESG |Section 2.1 of |
| |application | |[I-D.tiloca-core-oscore-discovery]|
| |group | | |
| |associated | | |
| |with a | | |
| |security group| | |
+---------------+--------------+----------+----------------------------------+
|hkdf |The HKDF |IESG |Section 2.1 of |
| |algorithm to | |[I-D.tiloca-core-oscore-discovery]|
| |use | | |
+---------------+--------------+----------+----------------------------------+
|cred_fmt |The format of |IESG |Section 2.1 of |
| |authentication| |[I-D.tiloca-core-oscore-discovery]|
| |credential to | | |
| |use | | |
+---------------+--------------+----------+----------------------------------+
|sign_enc_alg |The encryption|IESG |Section 2.1 of |
| |algorithm to | |[I-D.tiloca-core-oscore-discovery]|
| |use for | | |
| |encrypting | | |
| |signed | | |
| |messages | | |
+---------------+--------------+----------+----------------------------------+
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|sign_alg |The signature |IESG |Section 2.1 of |
| |algorithm to | |[I-D.tiloca-core-oscore-discovery]|
| |use | | |
+---------------+--------------+----------+----------------------------------+
|sign_alg_crv |The elliptic |IESG |Section 2.1 of |
| |curve of the | |[I-D.tiloca-core-oscore-discovery]|
| |used signature| | |
| |algorithm | | |
+---------------+--------------+----------+----------------------------------+
|sign_key_kty |The key type |IESG |Section 2.1 of |
| |of the used | |[I-D.tiloca-core-oscore-discovery]|
| |signing keys | | |
+---------------+--------------+----------+----------------------------------+
|sign_key_crv |The curve of |IESG |Section 2.1 of |
| |the used | |[I-D.tiloca-core-oscore-discovery]|
| |signing keys | | |
+---------------+--------------+----------+----------------------------------+
|alg |The encryption|IESG |Section 2.1 of |
| |algorithm to | |[I-D.tiloca-core-oscore-discovery]|
| |use for | | |
| |encrypting | | |
| |non-signed | | |
| |messages | | |
+---------------+--------------+----------+----------------------------------+
|ecdh_alg |The ECDH |IESG |Section 2.1 of |
| |algorithm to | |[I-D.tiloca-core-oscore-discovery]|
| |use | | |
+---------------+--------------+----------+----------------------------------+
|ecdh_alg_crv |The elliptic |IESG |Section 2.1 of |
| |curve of the | |[I-D.tiloca-core-oscore-discovery]|
| |used ECDH | | |
| |algorithm | | |
+---------------+--------------+----------+----------------------------------+
|ecdh_key_kty |The key type |IESG |Section 2.1 of |
| |of the used | |[I-D.tiloca-core-oscore-discovery]|
| |ECDH keys | | |
+---------------+--------------+----------+----------------------------------+
|ecdh_key_crv |The curve of |IESG |Section 2.1 of |
| |the used ECDH | |[I-D.tiloca-core-oscore-discovery]|
| |keys | | |
+---------------+--------------+----------+----------------------------------+
|det_hash_alg |The hash |IESG |Section 2.1 of |
| |algorithm to | |[I-D.tiloca-core-oscore-discovery]|
| |use for | | |
| |computing | | |
| |deterministic | | |
| |requests | | |
+---------------+--------------+----------+----------------------------------+
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|rekeying_scheme|The rekeying |IESG |Section 2.1 of |
| |scheme used to| |[I-D.tiloca-core-oscore-discovery]|
| |distribute new| | |
| |keying | | |
| |material | | |
+---------------+--------------+----------+----------------------------------+
Table 1: Initial Entries in the Target Attributes Registry
A number of names are reserved as they are used for parameters in
links other than target attributes, a further set is predefined in
[RFC8288].
3. Security considerations
The security considerations of [RFC8288] apply, as do those of the
discovery specifications [RFC6690], [RFC7252], and [RFC9176].
4. References
4.1. Normative References
[BCP26] Cotton, M., Leiba, B., and T. Narten, "Guidelines for
Writing an IANA Considerations Section in RFCs", BCP 26,
RFC 8126, DOI 10.17487/RFC8126, June 2017,
<https://www.rfc-editor.org/info/rfc8126>.
[IANA.core-parameters]
IANA, "Constrained RESTful Environments (CoRE)
Parameters", 8 June 2012,
<https://www.iana.org/assignments/core-parameters>.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/info/rfc2119>.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
May 2017, <https://www.rfc-editor.org/info/rfc8174>.
[RFC8288] Nottingham, M., "Web Linking", RFC 8288,
DOI 10.17487/RFC8288, October 2017,
<https://www.rfc-editor.org/info/rfc8288>.
[STD90] Cerf, V., "ASCII format for network interchange", STD 80,
RFC 20, DOI 10.17487/RFC0020, October 1969,
<https://www.rfc-editor.org/info/rfc20>.
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4.2. Informative References
[I-D.ietf-core-oscore-edhoc]
Palombini, F., Tiloca, M., Höglund, R., Hristozov, S., and
G. Selander, "Profiling EDHOC for CoAP and OSCORE", Work
in Progress, Internet-Draft, draft-ietf-core-oscore-edhoc-
05, 24 October 2022, <https://www.ietf.org/archive/id/
draft-ietf-core-oscore-edhoc-05.txt>.
[I-D.tiloca-core-oscore-discovery]
Tiloca, M., Amsüss, C., and P. Van der Stok, "Discovery of
OSCORE Groups with the CoRE Resource Directory", Work in
Progress, Internet-Draft, draft-tiloca-core-oscore-
discovery-12, 5 September 2022,
<https://www.ietf.org/archive/id/draft-tiloca-core-oscore-
discovery-12.txt>.
[RFC5988] Nottingham, M., "Web Linking", RFC 5988,
DOI 10.17487/RFC5988, October 2010,
<https://www.rfc-editor.org/info/rfc5988>.
[RFC6690] Shelby, Z., "Constrained RESTful Environments (CoRE) Link
Format", RFC 6690, DOI 10.17487/RFC6690, August 2012,
<https://www.rfc-editor.org/info/rfc6690>.
[RFC7252] Shelby, Z., Hartke, K., and C. Bormann, "The Constrained
Application Protocol (CoAP)", RFC 7252,
DOI 10.17487/RFC7252, June 2014,
<https://www.rfc-editor.org/info/rfc7252>.
[RFC7641] Hartke, K., "Observing Resources in the Constrained
Application Protocol (CoAP)", RFC 7641,
DOI 10.17487/RFC7641, September 2015,
<https://www.rfc-editor.org/info/rfc7641>.
[RFC8075] Castellani, A., Loreto, S., Rahman, A., Fossati, T., and
E. Dijk, "Guidelines for Mapping Implementations: HTTP to
the Constrained Application Protocol (CoAP)", RFC 8075,
DOI 10.17487/RFC8075, February 2017,
<https://www.rfc-editor.org/info/rfc8075>.
[RFC8613] Selander, G., Mattsson, J., Palombini, F., and L. Seitz,
"Object Security for Constrained RESTful Environments
(OSCORE)", RFC 8613, DOI 10.17487/RFC8613, July 2019,
<https://www.rfc-editor.org/info/rfc8613>.
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[RFC9176] Amsüss, C., Ed., Shelby, Z., Koster, M., Bormann, C., and
P. van der Stok, "Constrained RESTful Environments (CoRE)
Resource Directory", RFC 9176, DOI 10.17487/RFC9176, April
2022, <https://www.rfc-editor.org/info/rfc9176>.
Acknowledgements
TBD
Contributors
Jaime Jiménez
Ericsson
Email: jaime@iki.fi
Jaime provided the list of initial registrations.
Author's Address
Carsten Bormann
Universität Bremen TZI
Postfach 330440
D-28359 Bremen
Germany
Phone: +49-421-218-63921
Email: cabo@tzi.org
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