Internet DRAFT - draft-bormann-t2trg-rel-impl
draft-bormann-t2trg-rel-impl
Network Working Group C. Bormann
Internet-Draft Universität Bremen TZI
Intended status: Informational 27 September 2020
Expires: 31 March 2021
impl-info: A link relation type for disclosing implementation
information
draft-bormann-t2trg-rel-impl-02
Abstract
For debugging, it is often helpful to have information about the
implementation of a peer. The present specification defines a link
relation type, "impl-info", that can be used to convey such
information via self-description, such as in the "/.well-known/core"
resource.
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/.
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."
This Internet-Draft will expire on 31 March 2021.
Copyright Notice
Copyright (c) 2020 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents (https://trustee.ietf.org/
license-info) in effect on the date of publication of this document.
Please review these documents carefully, as they describe your rights
and restrictions with respect to this document. Code Components
extracted from this document must include Simplified BSD License text
as described in Section 4.e of the Trust Legal Provisions and are
provided without warranty as described in the Simplified BSD License.
Bormann Expires 31 March 2021 [Page 1]
Internet-Draft The impl-info relation type September 2020
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 2
3. Security considerations . . . . . . . . . . . . . . . . . . . 2
4. References . . . . . . . . . . . . . . . . . . . . . . . . . 3
4.1. Normative References . . . . . . . . . . . . . . . . . . 3
4.2. Informative References . . . . . . . . . . . . . . . . . 3
Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . 4
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 4
1. Introduction
When debugging an interoperability problem, it is often helpful to
have information about the implementation version of a peer. To
enable the disclosure of such information, HTTP defines header fields
such as Server and User-Agent [RFC7231].
In CoAP [RFC7252], it is rarely appropriate to send information of
this kind in every request or response. Instead, the present
specification defines a link relation type, "impl-info", that can be
used to convey this information via the self-description capabilities
of the "/.well-known/core" resource [RFC6690] and the CoRE resource
directory [I-D.ietf-core-resource-directory].
2. IANA Considerations
This specification requests the registration of the link relation
type "impl-info".
The registration template as per [RFC8288] follows.
* _Relation Name_: "impl-info"
* _Description_: Refers to implementation information that may be
helpful in diagnosing technical problems with the implementation
of the context, such as lists of components and their
implementation versions.
* _Reference_: [THIS]
3. Security considerations
The security considerations listed in Section 9.6 of [RFC7231] and
the sections referenced there apply.
Bormann Expires 31 March 2021 [Page 2]
Internet-Draft The impl-info relation type September 2020
The security considerations listed in Section 11.3 of [RFC7252]
apply. As adding another link to "/.well-known/core" does increase
the size of a response to a GET request for that resource, the
mitigation mentioned in that section to limit the amplification
factor becomes even more important.
Disclosing information about an implementation can make it easier for
an attacker to select an attack, or to build automated tools that
search for promising victims. Fingerprinting techniques can provide
information to attackers that is usable in the same way, so adding
information via self-description may or may not actually exacerbate
this problem.
4. References
4.1. Normative References
[RFC8288] Nottingham, M., "Web Linking", RFC 8288,
DOI 10.17487/RFC8288, October 2017,
<https://www.rfc-editor.org/info/rfc8288>.
[THIS] Bormann, C., "impl-info: A link relation type for
disclosing implementation information", Work in Progress,
Internet-Draft, draft-bormann-t2trg-rel-impl-01, 27 March
2020, <http://www.ietf.org/internet-drafts/draft-bormann-
t2trg-rel-impl-01.txt>.
4.2. Informative References
[I-D.ietf-core-resource-directory]
Shelby, Z., Koster, M., Bormann, C., Stok, P., and C.
Amsuess, "CoRE Resource Directory", Work in Progress,
Internet-Draft, draft-ietf-core-resource-directory-25, 13
July 2020, <http://www.ietf.org/internet-drafts/draft-
ietf-core-resource-directory-25.txt>.
[RFC6690] Shelby, Z., "Constrained RESTful Environments (CoRE) Link
Format", RFC 6690, DOI 10.17487/RFC6690, August 2012,
<https://www.rfc-editor.org/info/rfc6690>.
[RFC7231] Fielding, R., Ed. and J. Reschke, Ed., "Hypertext Transfer
Protocol (HTTP/1.1): Semantics and Content", RFC 7231,
DOI 10.17487/RFC7231, June 2014,
<https://www.rfc-editor.org/info/rfc7231>.
Bormann Expires 31 March 2021 [Page 3]
Internet-Draft The impl-info relation type September 2020
[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>.
Acknowledgements
The need for implementation information in the CoRE resource
directory has been identified by Peter van der Stok. Discussions
with Peter and with Christian Amsüss led to the present proposal of
employing self-description for this purpose.
Author's Address
Carsten Bormann
Universität Bremen TZI
Postfach 330440
D-28359 Bremen
Germany
Phone: +49-421-218-63921
Email: cabo@tzi.org
Bormann Expires 31 March 2021 [Page 4]
