[Docs] [txt|pdf] [Tracker] [WG] [Email] [Diff1] [Diff2] [Nits]

Versions: (draft-veillette-core-yang-library) 00 01 02

Internet Engineering Task Force                        M. Veillette, Ed.
Internet-Draft                                   Trilliant Networks Inc.
Intended status: Standards Track                          I. Petrov, Ed.
Expires: January 11, 2021                                         Acklio
                                                           July 10, 2020


                    Constrained YANG Module Library
                    draft-ietf-core-yang-library-02

Abstract

   This document describes a constrained version of the YANG library
   that provides information about the YANG modules, datastores, and
   datastore schemas used by a constrained network management server
   (e.g., a CORECONF server).

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 January 11, 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.



Veillette & Petrov      Expires January 11, 2021                [Page 1]


Internet-Draft       Constrained YANG Module Library           July 2020


Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Terminology and Notation  . . . . . . . . . . . . . . . . . .   2
   3.  Overview  . . . . . . . . . . . . . . . . . . . . . . . . . .   3
     3.1.  Tree diagram  . . . . . . . . . . . . . . . . . . . . . .   4
     3.2.  Major differences between ietf-constrained-yang-library
           and ietf-yang-library . . . . . . . . . . . . . . . . . .   4
   4.  YANG Module "ietf-constrained-yang-library" . . . . . . . . .   5
   5.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  13
     5.1.  YANG Module Registration  . . . . . . . . . . . . . . . .  13
     5.2.  YANG Namespace Registration . . . . . . . . . . . . . . .  13
   6.  Security Considerations . . . . . . . . . . . . . . . . . . .  13
   7.  Acknowledgments . . . . . . . . . . . . . . . . . . . . . . .  14
   8.  References  . . . . . . . . . . . . . . . . . . . . . . . . .  14
     8.1.  Normative References  . . . . . . . . . . . . . . . . . .  14
     8.2.  Informative References  . . . . . . . . . . . . . . . . .  16
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  16

1.  Introduction

   There is a need for a standard mechanism to expose which YANG
   modules, datastores and datastore schemas are in use by a constrained
   network management server.  This document defines the YANG module
   'ietf-constrained-yang-library' that provides this information.

   YANG module 'ietf-constrained-yang-library' shares the same data
   model and objectives as 'ietf-yang-library', only datatypes and
   mandatory requirements have been updated to minimize its size to
   allow its implementation by Constrained Nodes and/or Constrained
   Networks as defined by [RFC7228].  To review the list of objectives
   and the proposed data model, please refer to [RFC8525] section 2 and
   3.

2.  Terminology and Notation

   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.

   The following terms are defined in [RFC7950]: client, deviation,
   feature, module, submodule, and server.

   The following term is defined in [I-D.ietf-core-sid]: YANG Schema
   Item iDentifier (SID).




Veillette & Petrov      Expires January 11, 2021                [Page 2]


Internet-Draft       Constrained YANG Module Library           July 2020


   The following terms are defined in [RFC8525]: YANG library and YANG
   library checksum.

3.  Overview

   The conceptual model of the YANG library is depicted in Figure 1.

   +-----------+
   | datastore |
   +-----------+
        |
        | has a
        V
   +-----------+            +--------+                +------------+
   | datastore |  union of  | module |  consists of   | modules +  |
   |  schema   |----------->|  set   |--------------->| submodules |
   +-----------+            +--------+                +------------+

              Figure 1: Conceptual model of the YANG library

   It's expected that most constrained network management servers have
   one datastore (e.g. a unified datastore).  However, some servers may
   have multiples datastore as described by NMDA [RFC8342].  The YANG
   library data model supports both cases.

   In this model, every datastore has an associated datastore schema,
   which is the union of module sets, which is a collection of modules.
   Multiple datastores may refer to the same datastore schema and
   individual datastore schemas may share module sets.

   For each module, the YANG library provides:

   o  the YANG module identifier (i.e.  SID)

   o  its revision

   o  its list of submodules

   o  its list of imported modules

   o  its set of features and deviations

   YANG module namespace and location are also supported, but their
   implementation is not recommended for constrained servers.







Veillette & Petrov      Expires January 11, 2021                [Page 3]


Internet-Draft       Constrained YANG Module Library           July 2020


3.1.  Tree diagram

   The tree diagram of YANG module ietf-constrained-yang-library is
   provided below.  This graphical representation of a YANG module is
   defined in [RFC8340].

   module: ietf-constrained-yang-library
     +--ro yang-library
        +--ro module-set* [index]
        |  +--ro index                 uint8
        |  +--ro module* [identifier]
        |  |  +--ro identifier    sid:sid
        |  |  +--ro revision?     revision-identifier
        |  |  +--ro namespace?    inet:uri
        |  |  +--ro location*     inet:uri
        |  |  +--ro submodule* [identifier]
        |  |  |  +--ro identifier    sid:sid
        |  |  |  +--ro revision?     revision-identifier
        |  |  |  +--ro location*     inet:uri
        |  |  +--ro feature*      sid:sid
        |  |  +--ro deviation*    -> ../../module/identifier
        |  +--ro import-only-module* [identifier revision]
        |     +--ro identifier    sid:sid
        |     +--ro revision      union
        |     +--ro namespace?    inet:uri
        |     +--ro location*     inet:uri
        |     +--ro submodule* [identifier]
        |        +--ro identifier    sid:sid
        |        +--ro revision?     revision-identifier
        |        +--ro location*     inet:uri
        +--ro schema* [index]
        |  +--ro index         uint8
        |  +--ro module-set*   -> ../../module-set/index
        +--ro datastore* [identifier]
        |  +--ro identifier    ds:datastore-ref
        |  +--ro schema        -> ../../schema/index
        +--ro checksum      binary

     notifications:
       +---n yang-library-update
          +--ro checksum    -> /yang-library/checksum

3.2.  Major differences between ietf-constrained-yang-library and ietf-
      yang-library

   The changes between the reference data model 'ietf-yang-library' and
   its constrained version 'ietf-constrained-yang-library' are listed
   below:



Veillette & Petrov      Expires January 11, 2021                [Page 4]


Internet-Draft       Constrained YANG Module Library           July 2020


   o  module-set 'name' and schema 'name' are implemented using 8 bits
      unsigned integers and renamed 'index'.

   o  module 'name', submodule 'name' and datastore 'name' are
      implemented using a SID (i.e. an unsigned integer) and renamed
      'identifier'.

   o  'feature' and 'deviation' are implemented using a SID (i.e. an
      unsigned integer).

   o  'revision' fields are implemented using a 4 bytes binary string.

   o  the mandatory requirement of the 'namespace' fields is removed,
      and implementation is not recommended.  SIDs used by constrained
      devices and protocols don't require namespaces.

   o  the implementation of the 'location' fields are not recommended,
      the use of the module SID as the handle to retrieve the associated
      YANG module is proposed instead.

4.  YANG Module "ietf-constrained-yang-library"

   RFC Ed.: update the date below with the date of RFC publication and
   remove this note.

<CODE BEGINS> file "ietf-constrained-yang-library@2019-03-28.yang"
module ietf-constrained-yang-library {
  yang-version 1.1;
  namespace
    "urn:ietf:params:xml:ns:yang:ietf-constrained-yang-library";
  prefix "yanglib";

  // RFC Ed.: update ietf-core-sid reference.

  import ietf-sid-file {
    prefix sid;
    reference "RFC YYYY: YANG Schema Item iDentifier (SID)";
    // RFC Editor: Please replace YYYY with RFC number of I-D.ietf-core-sid.
  }
  import ietf-inet-types {
    prefix inet;
    reference "RFC 6991: Common YANG Data Types.";
  }
  import ietf-datastores {
    prefix ds;
    reference
      "RFC 8342: Network Management Datastore Architecture (NMDA).";
  }



Veillette & Petrov      Expires January 11, 2021                [Page 5]


Internet-Draft       Constrained YANG Module Library           July 2020


  organization
    "IETF CoRE Working Group";

  contact
    "WG Web:   <http://datatracker.ietf.org/wg/core/>

     WG List:  <mailto:core@ietf.org>

     Editor:   Michel Veillette
               <mailto:michel.veillette@trilliantinc.com>

     Editor:   Ivaylo Petrov
               <mailto:ivaylo@ackl.io>";

  description
    "This module provides information about the YANG modules,
     datastores, and datastore schemas implemented by a
     constrained network management server.

     Copyright (c) 2018 IETF Trust and the persons identified as
     authors of the code.  All rights reserved.

     Redistribution and use in source and binary forms, with or
     without modification, is permitted pursuant to, and subject
     to the license terms contained in, the Simplified BSD License
     set forth in Section 4.c of the IETF Trust's Legal Provisions
     Relating to IETF Documents
     (http://trustee.ietf.org/license-info).

     This version of this YANG module is part of RFC XXXX; see
     the RFC itself for full legal notices.";

  // RFC Editor: Please replace XXXX with RFC number and remove this note

  revision 2019-03-28 {
    description
      "Second revision.";
    reference
      "RFC XXXX: Constrained YANG Module Library";
    // RFC Editor: Please replace XXXX with RFC number and remove this note
  }

  /*
   * Typedefs
   */

  typedef revision-identifier {
    type binary {



Veillette & Petrov      Expires January 11, 2021                [Page 6]


Internet-Draft       Constrained YANG Module Library           July 2020


      length "4";
    }
    description
      "Revision date encoded as a binary string, each nibble
       representing a digit of the revision date. For example,
       revision 2018-09-21 is encoded as 0x20 0x18 0x09 0x21.";
  }

  /*
   * Groupings
   */

  grouping module-identification-leafs {
    description
      "Parameters for identifying YANG modules and submodules.";

    leaf identifier {
      type sid:sid;
      mandatory true;
      description
        "SID assigned to this module or submodule.";
    }
    leaf revision {
      type revision-identifier;
      description
        "The YANG module or submodule revision date.  If no
         revision statement is present in the YANG module
         or submodule, this leaf is not instantiated.";
    }
  }

  grouping location-leaf-list {
    description
      "Common location leaf list parameter for modules and
       submodules.";

    leaf-list location {
      type inet:uri;
      description
        "Contains a URL that represents the YANG schema resource
         for this module or submodule.

         This leaf is present in the model to keep the alignment
         with 'ietf-yang-library'. Support of this leaf in
         constrained devices is not necessarily required, nor
         expected. It is recommended that clients used the module
         or sub-module SID as the handle used to retrieve the
         corresponding YANG module";



Veillette & Petrov      Expires January 11, 2021                [Page 7]


Internet-Draft       Constrained YANG Module Library           July 2020


    }
  }

  grouping implementation-parameters {
    description
      "Parameters for describing the implementation of a module.";

    leaf-list feature {
      type sid:sid;
      description
        "List of all YANG feature names from this module that are
         supported by the server, regardless whether they are
         defined in the module or any included submodule.";
    }
    leaf-list deviation {
      type leafref {
        path "../../module/identifier";
      }
      description
        "List of all YANG deviation modules used by this server to
         modify the conformance of the module associated with this
         entry.  Note that the same module can be used for
         deviations for multiple modules, so the same entry MAY
         appear within multiple 'module' entries.

         This reference MUST NOT (directly or indirectly)
         refer to the module being deviated.

         Robust clients may want to make sure that they handle a
         situation where a module deviates itself (directly or
         indirectly) gracefully.";
    }
  }

  grouping module-set-parameters {
    description
      "A set of parameters that describe a module set.";

    leaf index {
      type uint8;
      description
        "An arbitrary number assigned of the module set.";
    }
    list module {
      key "identifier";
      description
        "An entry in this list represents a module implemented
         by the server, as per RFC 7950 section 5.6.5, with a



Veillette & Petrov      Expires January 11, 2021                [Page 8]


Internet-Draft       Constrained YANG Module Library           July 2020


         particular set of supported features and deviations.";
      reference
        "RFC 7950: The YANG 1.1 Data Modeling Language.";

      uses module-identification-leafs;

      leaf namespace {
        type inet:uri;
        description
          "The XML namespace identifier for this module.
           This leaf is present in the model to keep the alignment
           with 'ietf-yang-library'. Support of this leaf in
           constrained devices is not required, nor expected.";
      }

      uses location-leaf-list;

      list submodule {
        key "identifier";
        description
          "Each entry represents one submodule within the parent
           module.";
        uses module-identification-leafs;
        uses location-leaf-list;
      }

      uses implementation-parameters;
    }
    list import-only-module {
      key "identifier revision";
      description
        "An entry in this list indicates that the server imports
         reusable definitions from the specified revision of the
         module, but does not implement any protocol accessible
         objects from this revision.

         Multiple entries for the same module name MAY exist.
         This can occur if multiple modules import the same
         module, but specify different revision-dates in the
         import statements.";

      leaf identifier {
        type sid:sid;
        description
          "The YANG module name.";
      }
      leaf revision {
        type union {



Veillette & Petrov      Expires January 11, 2021                [Page 9]


Internet-Draft       Constrained YANG Module Library           July 2020


          type revision-identifier;
          type string {
            length 0;
          }
        }
        description
          "The YANG module revision date.";
      }
      leaf namespace {
        type inet:uri;
        description
          "The XML namespace identifier for this module.
           This leaf is present in the model to keep the alignment
           with 'ietf-yang-library'. Support of this leaf in
           constrained devices is not required, nor expected.";
      }

      uses location-leaf-list;

      list submodule {
        key "identifier";
        description
          "Each entry represents one submodule within the
           parent module.";

        uses module-identification-leafs;
        uses location-leaf-list;
      }
    }
  }

  grouping yang-library-parameters {
    description
      "The YANG library data structure is represented as a grouping
       so it can be reused in configuration or another monitoring
       data structure.";

    list module-set {
      key index;
      description
        "A set of modules that may be used by one or more schemas.

         A module set does not have to be referentially complete,
         i.e., it may define modules that contain import statements
         for other modules not included in the module set.";

      uses module-set-parameters;
    }



Veillette & Petrov      Expires January 11, 2021               [Page 10]


Internet-Draft       Constrained YANG Module Library           July 2020


    list schema {
      key "index";
      description
        "A datastore schema that may be used by one or more
         datastores.

         The schema must be valid and referentially complete,
         i.e., it must contain modules to satisfy all used import
         statements for all modules specified in the schema.";

      leaf index {
        type uint8;
        description
          "An arbitrary reference number assigned to the schema.";
      }
      leaf-list module-set {
        type leafref {
          path "../../module-set/index";
        }
        description
          "A set of module-sets that are included in this schema.
           If a non import-only module appears in multiple module
           sets, then the module revision and the associated
           features and deviations must be identical.";
      }
    }

    list datastore {
      key "identifier";
      description
        "A datastore supported by this server.

         Each datastore indicates which schema it supports.

         The server MUST instantiate one entry in this list
         per specific datastore it supports.

         Each datstore entry with the same datastore schema
         SHOULD reference the same schema.";

      leaf identifier {
        type ds:datastore-ref;
        description
          "The identity of the datastore.";
      }
      leaf schema {
        type leafref {
          path "../../schema/index";



Veillette & Petrov      Expires January 11, 2021               [Page 11]


Internet-Draft       Constrained YANG Module Library           July 2020


        }
        mandatory true;
        description
          "A reference to the schema supported by this datastore.
           All non import-only modules of the schema are
           implementedwith their associated features and
           deviations.";
      }
    }
  }

  /*
   * Top-level container
   */

  container yang-library {
    config false;
    description
      "Container holding the entire YANG library of this server.";

    uses yang-library-parameters;

    leaf checksum {
      type binary;
      mandatory true;
      description
        "A server-generated checksum or digest of the contents of
         the 'yang-library' tree.  The server MUST change the
         value of this leaf if the information represented by
         the 'yang-library' tree, except 'yang-library/checksum',
         has changed.";
    }
  }

  /*
   * Notifications
   */

  notification yang-library-update {
    description
      "Generated when any YANG library information on the
       server has changed.";

    leaf checksum {
      type leafref {
        path "/yanglib:yang-library/yanglib:checksum";
      }
      mandatory true;



Veillette & Petrov      Expires January 11, 2021               [Page 12]


Internet-Draft       Constrained YANG Module Library           July 2020


      description
        "Contains the YANG library checksum or digest for the
         updated YANG library at the time the notification is
         generated.";
    }
  }
}
<CODE ENDS>

5.  IANA Considerations

5.1.  YANG Module Registration

   This document registers one YANG module in the YANG Module Names
   registry [RFC7950].

   name: ietf-constrained-yang-library

   namespace: urn:ietf:params:xml:ns:yang:ietf-constrained-yang-library

   prefix: lib

   reference: RFC XXXX

   // RFC Ed.: replace XXXX with RFC number and remove this note

5.2.  YANG Namespace Registration

   This document registers the following XML namespace URN in the "IETF
   XML Registry", following the format defined in [RFC3688]:

   URI: please assign urn:ietf:params:xml:ns:yang:ietf-constrained-yang-
   library

   Registrant Contact: The IESG.

   XML: N/A, the requested URI is an XML namespace.

   Reference: RFC XXXX

   // RFC Ed.: replace XXXX with RFC number and remove this note

6.  Security Considerations

   The YANG module specified in this document defines a schema for data
   that is designed to be accessed via network management protocols such
   as NETCONF [RFC6241], RESTCONF [RFC8040] or CORECONF
   [I-D.ietf-core-comi].  The lowest NETCONF layer is the secure



Veillette & Petrov      Expires January 11, 2021               [Page 13]


Internet-Draft       Constrained YANG Module Library           July 2020


   transport layer, and the mandatory-to-implement secure transport is
   Secure Shell (SSH) [RFC6242].  The lowest RESTCONF layer is HTTPS,
   and the mandatory-to-implement secure transport is TLS [RFC8446].
   The lowest CORECONF layer is CoAP [RFC7252] and the mandatory-to-
   implement security transport is any one of DTLS [RFC6347] and OSCORE
   [RFC8613].

   The Network Configuration Access Control Model (NACM) [RFC8341]
   provides the means to restrict access for particular NETCONF or
   RESTCONF users to a preconfigured subset of all available NETCONF or
   RESTCONF protocol operations and content.

   Some of the readable data nodes in this YANG module may be considered
   sensitive or vulnerable in some network environments.  It is thus
   important to control read access (e.g., via get, get-config, or
   notification) to these data nodes.

   Specifically, the 'module' list may help an attacker to identify the
   server capabilities and server implementations with known bugs.
   Server vulnerabilities may be specific to particular modules, module
   revisions, module features, or even module deviations.  This
   information is included in each module entry.  For example, if a
   particular operation on a particular data node is known to cause a
   server to crash or significantly degrade device performance, then the
   module list information will help an attacker to identify server
   implementations with such a defect, in order to launch a denial of
   service attack on these devices.

7.  Acknowledgments

   The YANG module defined by this memo has been derived from an already
   existing YANG module, ietf-yang-library [RFC8525], we will like to
   thank the authors of this YANG module.  A special thank also to Andy
   Bierman for his initial recommendations for the creation of this YANG
   module.  The authors would also like to thank Tom Petch for his help
   during the development of this document and his useful comments
   during the review process.

8.  References

8.1.  Normative References

   [I-D.ietf-core-comi]
              Veillette, M., Stok, P., Pelov, A., Bierman, A., and I.
              Petrov, "CoAP Management Interface (CORECONF)", draft-
              ietf-core-comi-10 (work in progress), July 2020.





Veillette & Petrov      Expires January 11, 2021               [Page 14]


Internet-Draft       Constrained YANG Module Library           July 2020


   [I-D.ietf-core-sid]
              Veillette, M., Pelov, A., and I. Petrov, "YANG Schema Item
              iDentifier (YANG SID)", draft-ietf-core-sid-14 (work in
              progress), July 2020.

   [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>.

   [RFC3688]  Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688,
              DOI 10.17487/RFC3688, January 2004,
              <https://www.rfc-editor.org/info/rfc3688>.

   [RFC6241]  Enns, R., Ed., Bjorklund, M., Ed., Schoenwaelder, J., Ed.,
              and A. Bierman, Ed., "Network Configuration Protocol
              (NETCONF)", RFC 6241, DOI 10.17487/RFC6241, June 2011,
              <https://www.rfc-editor.org/info/rfc6241>.

   [RFC6242]  Wasserman, M., "Using the NETCONF Protocol over Secure
              Shell (SSH)", RFC 6242, DOI 10.17487/RFC6242, June 2011,
              <https://www.rfc-editor.org/info/rfc6242>.

   [RFC6347]  Rescorla, E. and N. Modadugu, "Datagram Transport Layer
              Security Version 1.2", RFC 6347, DOI 10.17487/RFC6347,
              January 2012, <https://www.rfc-editor.org/info/rfc6347>.

   [RFC6991]  Schoenwaelder, J., Ed., "Common YANG Data Types",
              RFC 6991, DOI 10.17487/RFC6991, July 2013,
              <https://www.rfc-editor.org/info/rfc6991>.

   [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>.

   [RFC7950]  Bjorklund, M., Ed., "The YANG 1.1 Data Modeling Language",
              RFC 7950, DOI 10.17487/RFC7950, August 2016,
              <https://www.rfc-editor.org/info/rfc7950>.

   [RFC8040]  Bierman, A., Bjorklund, M., and K. Watsen, "RESTCONF
              Protocol", RFC 8040, DOI 10.17487/RFC8040, January 2017,
              <https://www.rfc-editor.org/info/rfc8040>.

   [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>.




Veillette & Petrov      Expires January 11, 2021               [Page 15]


Internet-Draft       Constrained YANG Module Library           July 2020


   [RFC8340]  Bjorklund, M. and L. Berger, Ed., "YANG Tree Diagrams",
              BCP 215, RFC 8340, DOI 10.17487/RFC8340, March 2018,
              <https://www.rfc-editor.org/info/rfc8340>.

   [RFC8341]  Bierman, A. and M. Bjorklund, "Network Configuration
              Access Control Model", STD 91, RFC 8341,
              DOI 10.17487/RFC8341, March 2018,
              <https://www.rfc-editor.org/info/rfc8341>.

   [RFC8342]  Bjorklund, M., Schoenwaelder, J., Shafer, P., Watsen, K.,
              and R. Wilton, "Network Management Datastore Architecture
              (NMDA)", RFC 8342, DOI 10.17487/RFC8342, March 2018,
              <https://www.rfc-editor.org/info/rfc8342>.

   [RFC8446]  Rescorla, E., "The Transport Layer Security (TLS) Protocol
              Version 1.3", RFC 8446, DOI 10.17487/RFC8446, August 2018,
              <https://www.rfc-editor.org/info/rfc8446>.

   [RFC8525]  Bierman, A., Bjorklund, M., Schoenwaelder, J., Watsen, K.,
              and R. Wilton, "YANG Library", RFC 8525,
              DOI 10.17487/RFC8525, March 2019,
              <https://www.rfc-editor.org/info/rfc8525>.

   [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>.

8.2.  Informative References

   [RFC7228]  Bormann, C., Ersue, M., and A. Keranen, "Terminology for
              Constrained-Node Networks", RFC 7228,
              DOI 10.17487/RFC7228, May 2014,
              <https://www.rfc-editor.org/info/rfc7228>.

Authors' Addresses

   Michel Veillette (editor)
   Trilliant Networks Inc.
   610 Rue du Luxembourg
   Granby, Quebec  J2J 2V2
   Canada

   Email: michel.veillette@trilliantinc.com







Veillette & Petrov      Expires January 11, 2021               [Page 16]


Internet-Draft       Constrained YANG Module Library           July 2020


   Ivaylo Petrov (editor)
   Acklio
   1137A avenue des Champs Blancs
   Cesson-Sevigne, Bretagne  35510
   France

   Email: ivaylo@ackl.io












































Veillette & Petrov      Expires January 11, 2021               [Page 17]


Html markup produced by rfcmarkup 1.129d, available from https://tools.ietf.org/tools/rfcmarkup/