CDDL models for some existing RFCs
draft-bormann-cbor-rfc-cddl-models-01

Network Working Group                                         C. Bormann
Internet-Draft                                    Universität Bremen TZI
Intended status: Informational                          25 February 2023
Expires: 29 August 2023

                   CDDL models for some existing RFCs
                 draft-bormann-cbor-rfc-cddl-models-01

Abstract

   A number of CBOR- and JSON-based protocols have been defined before
   CDDL was standardized or widely used.

   This short draft records some CDDL definitions for such protocols,
   which could become part of a library of CDDL definitions available
   for use in CDDL2 processors.  It focuses on CDDL in (almost)
   published IETF RFCs.

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
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   material or to cite them other than as "work in progress."

   This Internet-Draft will expire on 29 August 2023.

Copyright Notice

   Copyright (c) 2023 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

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   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 Revised BSD License text as
   described in Section 4.e of the Trust Legal Provisions and are
   provided without warranty as described in the Revised BSD License.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  CDDL definitions for (almost) published RFCs  . . . . . . . .   2
     2.1.  RFC 7071  . . . . . . . . . . . . . . . . . . . . . . . .   2
     2.2.  RFC 8366  . . . . . . . . . . . . . . . . . . . . . . . .   3
     2.3.  7807bis . . . . . . . . . . . . . . . . . . . . . . . . .   3
     2.4.  YANG-SID  . . . . . . . . . . . . . . . . . . . . . . . .   4
     2.5.  Your favorite RFC here... . . . . . . . . . . . . . . . .   5
   3.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   5
   4.  Security considerations . . . . . . . . . . . . . . . . . . .   5
   5.  References  . . . . . . . . . . . . . . . . . . . . . . . . .   5
     5.1.  Normative References  . . . . . . . . . . . . . . . . . .   5
     5.2.  Informative References  . . . . . . . . . . . . . . . . .   6
   Acknowledgements  . . . . . . . . . . . . . . . . . . . . . . . .   7
   Author's Address  . . . . . . . . . . . . . . . . . . . . . . . .   7

1.  Introduction

   (Please see abstract.)  Add in [STD94] [STD90] [RFC8610] [RFC9165]
   [I-D.bormann-cbor-cddl-more-control]

2.  CDDL definitions for (almost) published RFCs

   This section is intended to have one subsection for each CDDL data
   model presented for an existing RFC.  As a start, it is fleshed out
   with three such data models.

2.1.  RFC 7071

   Appendix H of [RFC8610] contains two CDDL definitions for [RFC7071],
   which are not copied here.  Typically, the compact form would be used
   in applications using the RFC 7071 format; while the extended form
   might be useful to cherry-pick features of RFC 7071 into another
   protocol.

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2.2.  RFC 8366

   [RFC8366] defines a data model for a "Voucher Artifact", which can be
   represented in CDDL as:

   voucher-artifact = {
     "ietf-voucher:voucher": {
       created-on: yang$date-and-time
       ? (
           expires-on: yang$date-and-time
           ? last-renewal-date: yang$date-and-time
           //
           nonce: json-binary<bytes .size (8..32)>
         )
       assertion: assertion
       serial-number: text
       ? idevid-issuer: json-binary<bytes>
       pinned-domain-cert: json-binary<bytes>
       ? domain-cert-revocation-checks: bool
     }
   }

   assertion = "verified" / "logged" / "proximity"

   yang$date-and-time = text .regexp cat3<"[0-9]{4}-[0-9]{2}-[0-9]{2}T",
                               "[0-9]{2}:[0-9]{2}:[0-9]{2}([.][0-9]+)?",
                               "(Z|[+-][0-9]{2}:[0-9]{2})">

   cat3<A,B,C> = (A .cat B) .cat C

   json-binary<T> = text .b64c T

   The two examples in the RFC can be validated with this little patchup
   script:

   sed -e s/ue=/uQ=/ -e s/'"true"'/true/ | cddl rfc8366.cddl vp -

2.3.  7807bis

   The RFC to be published out of [_7807bis] defines a simple data model
   that is reproduced in CDDL here:

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   problem-object = {
     ? type: ~uri
     ? title: text
     ? status: 100..599
     ? detail: text
     ? instance: ~uri
     * (text .regexp "\\*.*")
       .feature "standard-problem-object-extension" => any
     * text .feature "problem-object-extension" => any
   }

   Note that Appendix B of [RFC9290] also defines a CBOR-specific data
   model that may be useful for tunneling [RFC7807] problem details in
   [RFC9290] Concise Problem Details.

2.4.  YANG-SID

   The RFC to be published out of [YANG-SID] defines a data model for a
   "SID file" in YANG, to be transported as a YANG-JSON instance.

   An equivalent CDDL data model is given here:

   sid-file = {
     "ietf-sid-file:sid-file": {
       module-name: yang$yang-identifier
       ? module-revision: revision-identifier
       ? sid-file-version: sid-file-version-identifier
       ? sid-file-status: "unpublished" / "published"
       ? description: text
       ? dependency-revision: [* dependency-revision]
       ? assignment-range: [* assignment-range]
       ? item: [*item]
     }
   }

   rep<RE>=cat3<"(", RE, ")*">
   opt<RE>=cat3<"(", RE, ")?">
   cat3<A,B,C> = (A .cat B) .cat C

   id-re = "[a-zA-Z_][a-zA-Z0-9\\-_.]*"
   yang$yang-identifier = text .regexp id-re
   revision-identifier = text .regexp "[0-9]{4}-[0-9]{2}-[0-9]{2}"
   sid-file-version-identifier = uint .size 4
   sid = text .decimal (0..9223372036854775807)
   plus-id<Prefix> = Prefix .cat id-re
   schema-node-re = cat3<plus-id<"/">, plus-id<":">, ; qualified
                         rep<plus-id<"/"> .cat       ; optionally
                             opt<plus-id<":">> > >     ; qualified

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   schema-node-path = text .regexp schema-node-re

   dependency-revision = {
     module-name: yang$yang-identifier
     module-revision: revision-identifier
   }

   assignment-range = {
     entry-point: sid
     size: sid
   }

   item = {
     ? status: "stable" / "unstable" / "obsolete"
     (
       namespace: "module" / "identity" / "feature"
       identifier: yang$yang-identifier
     //
       namespace: "data"
       identifier: schema-node-path
     )
     sid: sid
   }

2.5.  Your favorite RFC here...

3.  IANA Considerations

   This document makes no requests of IANA.

4.  Security considerations

   The security considerations of [RFC8610], [RFC9165],
   [I-D.bormann-cbor-cddl-more-control], [STD94] and [STD90] apply.
   This collection of CDDL models is not thought to create new security
   considerations.  Errors in the models could -- if we knew of them,
   we'd fix those errors instead of explaining their security
   consequences in this section.

5.  References

5.1.  Normative References

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   [I-D.bormann-cbor-cddl-more-control]
              Bormann, C., "More Control Operators for CDDL", Work in
              Progress, Internet-Draft, draft-bormann-cbor-cddl-more-
              control-00, 25 February 2023,
              <https://datatracker.ietf.org/doc/html/draft-bormann-cbor-
              cddl-more-control-00>.

   [RFC8610]  Birkholz, H., Vigano, C., and C. Bormann, "Concise Data
              Definition Language (CDDL): A Notational Convention to
              Express Concise Binary Object Representation (CBOR) and
              JSON Data Structures", RFC 8610, DOI 10.17487/RFC8610,
              June 2019, <https://www.rfc-editor.org/rfc/rfc8610>.

   [RFC9165]  Bormann, C., "Additional Control Operators for the Concise
              Data Definition Language (CDDL)", RFC 9165,
              DOI 10.17487/RFC9165, December 2021,
              <https://www.rfc-editor.org/rfc/rfc9165>.

   [STD90]    Bray, T., Ed., "The JavaScript Object Notation (JSON) Data
              Interchange Format", STD 90, RFC 8259,
              DOI 10.17487/RFC8259, December 2017,
              <https://www.rfc-editor.org/rfc/rfc8259>.

   [STD94]    Bormann, C. and P. Hoffman, "Concise Binary Object
              Representation (CBOR)", STD 94, RFC 8949,
              DOI 10.17487/RFC8949, December 2020,
              <https://www.rfc-editor.org/rfc/rfc8949>.

5.2.  Informative References

   [RFC7071]  Borenstein, N. and M. Kucherawy, "A Media Type for
              Reputation Interchange", RFC 7071, DOI 10.17487/RFC7071,
              November 2013, <https://www.rfc-editor.org/rfc/rfc7071>.

   [RFC7807]  Nottingham, M. and E. Wilde, "Problem Details for HTTP
              APIs", RFC 7807, DOI 10.17487/RFC7807, March 2016,
              <https://www.rfc-editor.org/rfc/rfc7807>.

   [RFC8366]  Watsen, K., Richardson, M., Pritikin, M., and T. Eckert,
              "A Voucher Artifact for Bootstrapping Protocols",
              RFC 8366, DOI 10.17487/RFC8366, May 2018,
              <https://www.rfc-editor.org/rfc/rfc8366>.

   [RFC9290]  Fossati, T. and C. Bormann, "Concise Problem Details for
              Constrained Application Protocol (CoAP) APIs", RFC 9290,
              DOI 10.17487/RFC9290, October 2022,
              <https://www.rfc-editor.org/rfc/rfc9290>.

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   [YANG-SID] Veillette, M., Pelov, A., Petrov, I., Bormann, C., and M.
              Richardson, "YANG Schema Item iDentifier (YANG SID)", Work
              in Progress, Internet-Draft, draft-ietf-core-sid-19, 26
              July 2022, <https://datatracker.ietf.org/doc/html/draft-
              ietf-core-sid-19>.

   [_7807bis] Nottingham, M., Wilde, E., and S. Dalal, "Problem Details
              for HTTP APIs", Work in Progress, Internet-Draft, draft-
              ietf-httpapi-rfc7807bis-05, 26 January 2023,
              <https://datatracker.ietf.org/doc/html/draft-ietf-httpapi-
              rfc7807bis-05>.

Acknowledgements

   TBD

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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