Skip to main content

A YANG Data Model for a Keystore
draft-ietf-netconf-keystore-15

The information below is for an old version of the document.
Document Type
This is an older version of an Internet-Draft whose latest revision state is "Active".
Author Kent Watsen
Last updated 2019-11-20 (Latest revision 2019-11-02)
Replaces draft-ietf-netconf-system-keychain
RFC stream Internet Engineering Task Force (IETF)
Formats
Reviews
Additional resources Mailing list discussion
Stream WG state WG Document
Document shepherd (None)
IESG IESG state I-D Exists
Consensus boilerplate Unknown
Telechat date (None)
Responsible AD (None)
Send notices to (None)
draft-ietf-netconf-keystore-15
NETCONF Working Group                                          K. Watsen
Internet-Draft                                           Watsen Networks
Intended status: Standards Track                       November 20, 2019
Expires: May 23, 2020

                    A YANG Data Model for a Keystore
                     draft-ietf-netconf-keystore-15

Abstract

   This document defines a YANG 1.1 module called "ietf-keystore" that
   enables centralized configuration of both symmetric and asymmetric
   keys.  The secret value for both key types may be encrypted.
   Asymmetric keys may be associated with certificates.  Notifications
   are sent when certificates are about to expire.

Editorial Note (To be removed by RFC Editor)

   This draft contains many placeholder values that need to be replaced
   with finalized values at the time of publication.  This note
   summarizes all of the substitutions that are needed.  No other RFC
   Editor instructions are specified elsewhere in this document.

   Artwork in this document contains shorthand references to drafts in
   progress.  Please apply the following replacements:

   o  "AAAA" --> the assigned RFC value for
      [I-D.ietf-netconf-crypto-types].

   o  "XXXX" --> the assigned RFC value for this draft

   Artwork in this document contains placeholder values for the date of
   publication of this draft.  Please apply the following replacement:

   o  "2019-11-20" --> the publication date of this draft

   The following Appendix section is to be removed prior to publication:

   o  Appendix A.  Change Log

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

Watsen                    Expires May 23, 2020                  [Page 1]
Internet-Draft      A YANG Data Model for a Keystore       November 2019

   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 May 23, 2020.

Copyright Notice

   Copyright (c) 2019 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.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   3
   2.  Requirements Language . . . . . . . . . . . . . . . . . . . .   4
   3.  The Keystore Model  . . . . . . . . . . . . . . . . . . . . .   4
     3.1.  Tree Diagram  . . . . . . . . . . . . . . . . . . . . . .   4
     3.2.  Example Usage . . . . . . . . . . . . . . . . . . . . . .  14
       3.2.1.  A Keystore Instance . . . . . . . . . . . . . . . . .  14
       3.2.2.  The "generate-symmetric-key" RPC  . . . . . . . . . .  16
       3.2.3.  The "generate-asymmetric-key" RPC . . . . . . . . . .  17
       3.2.4.  Notable Keystore Groupings  . . . . . . . . . . . . .  18
     3.3.  YANG Module . . . . . . . . . . . . . . . . . . . . . . .  22
   4.  Support for Built-in Keys . . . . . . . . . . . . . . . . . .  33
   5.  Security Considerations . . . . . . . . . . . . . . . . . . .  34
   6.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  35
     6.1.  The IETF XML Registry . . . . . . . . . . . . . . . . . .  35
     6.2.  The YANG Module Names Registry  . . . . . . . . . . . . .  35
   7.  References  . . . . . . . . . . . . . . . . . . . . . . . . .  35
     7.1.  Normative References  . . . . . . . . . . . . . . . . . .  35
     7.2.  Informative References  . . . . . . . . . . . . . . . . .  36
   Appendix A.  Change Log . . . . . . . . . . . . . . . . . . . . .  37
     A.1.  00 to 01  . . . . . . . . . . . . . . . . . . . . . . . .  37
     A.2.  01 to 02  . . . . . . . . . . . . . . . . . . . . . . . .  37

Watsen                    Expires May 23, 2020                  [Page 2]
Internet-Draft      A YANG Data Model for a Keystore       November 2019

     A.3.  02 to 03  . . . . . . . . . . . . . . . . . . . . . . . .  37
     A.4.  03 to 04  . . . . . . . . . . . . . . . . . . . . . . . .  37
     A.5.  04 to 05  . . . . . . . . . . . . . . . . . . . . . . . .  38
     A.6.  05 to 06  . . . . . . . . . . . . . . . . . . . . . . . .  38
     A.7.  06 to 07  . . . . . . . . . . . . . . . . . . . . . . . .  38
     A.8.  07 to 08  . . . . . . . . . . . . . . . . . . . . . . . .  38
     A.9.  08 to 09  . . . . . . . . . . . . . . . . . . . . . . . .  38
     A.10. 09 to 10  . . . . . . . . . . . . . . . . . . . . . . . .  39
     A.11. 10 to 11  . . . . . . . . . . . . . . . . . . . . . . . .  39
     A.12. 11 to 12  . . . . . . . . . . . . . . . . . . . . . . . .  39
     A.13. 12 to 13  . . . . . . . . . . . . . . . . . . . . . . . .  40
     A.14. 13 to 14  . . . . . . . . . . . . . . . . . . . . . . . .  40
     A.15. 14 to 15  . . . . . . . . . . . . . . . . . . . . . . . .  40
   Acknowledgements  . . . . . . . . . . . . . . . . . . . . . . . .  40
   Author's Address  . . . . . . . . . . . . . . . . . . . . . . . .  40

1.  Introduction

   This document defines a YANG 1.1 [RFC7950] module called "ietf-
   keystore" that enables centralized configuration of both symmetric
   and asymmetric keys.  The secret value for both key types may be
   encrypted.  Asymmetric keys may be associated with certificates.
   Notifications are sent when certificates are about to expire.

   The "ietf-keystore" module defines many "grouping" statements
   intended for use by other modules that may import it.  For instance,
   there are groupings that defined enabling a key to be either
   configured locally (within the defining data model) or be a reference
   to a key in the keystore.

   Special consideration has been given for systems that have
   cryptographic hardware, such as a Trusted Protection Module (TPM).
   These systems are unique in that the cryptographic hardware hides the
   secret key values.  To support such hardware, symmetric keys may have
   the value "hidden-key" and asymmetric keys may have the value
   "hidden-private-key".  While how such keys are created or destroyed
   is outside the scope of this document, the keystore can contain
   entries for such keys, enabling them to be reference by other
   configuration elements.

   This document in compliant with Network Management Datastore
   Architecture (NMDA) [RFC8342].  For instance, keys and associated
   certificates installed during manufacturing (e.g., for a IDevID
   [Std-802.1AR-2009] certificate), are expected to appear in
   <operational> (see Section 4).

   It is not required that a system has an operating system level
   keystore utility to implement this module.

Watsen                    Expires May 23, 2020                  [Page 3]
Internet-Draft      A YANG Data Model for a Keystore       November 2019

2.  Requirements Language

   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.

3.  The Keystore Model

3.1.  Tree Diagram

   This section provides a tree diagrams [RFC8340] for the "ietf-
   keystore" module that presents both the protocol-accessible
   "keystore" as well the all the groupings intended for external usage.

   module: ietf-keystore
     +--rw keystore
        +--rw asymmetric-keys
        |  +--rw asymmetric-key* [name]
        |  |  +--rw name                                    string
        |  |  +--rw algorithm
        |  |  |       iasa:asymmetric-algorithm-type
        |  |  +--rw public-key-format?                      identityref
        |  |  +--rw public-key                              binary
        |  |  +--rw private-key-format?                     identityref
        |  |  +--rw (private-key-type)
        |  |  |  +--:(private-key)
        |  |  |  |  +--rw private-key?                      binary
        |  |  |  +--:(hidden-private-key)
        |  |  |  |  +--rw hidden-private-key?               empty
        |  |  |  +--:(encrypted-private-key)
        |  |  |     +--rw encrypted-private-key
        |  |  |        +--rw (key-type)
        |  |  |        |  +--:(symmetric-key-ref)
        |  |  |        |  |  +--rw symmetric-key-ref?    leafref
        |  |  |        |  |          {keystore-supported}?
        |  |  |        |  +--:(asymmetric-key-ref)
        |  |  |        |     +--rw asymmetric-key-ref?   leafref
        |  |  |        |             {keystore-supported}?
        |  |  |        +--rw value?                      binary
        |  |  +--rw certificates
        |  |  |  +--rw certificate* [name]
        |  |  |     +--rw name                      string
        |  |  |     +--rw cert?                     end-entity-cert-cms
        |  |  |     +---n certificate-expiration
        |  |  |        +-- expiration-date    yang:date-and-time
        |  |  +---x generate-certificate-signing-request

Watsen                    Expires May 23, 2020                  [Page 4]
Internet-Draft      A YANG Data Model for a Keystore       November 2019

        |  |     +---w input
        |  |     |  +---w subject       binary
        |  |     |  +---w attributes?   binary
        |  |     +--ro output
        |  |        +--ro certificate-signing-request    binary
        |  +---x generate-asymmetric-key
        |     +---w input
        |     |  +---w algorithm       iasa:asymmetric-algorithm-type
        |     |  +---w encrypt-with!
        |     |     +---w (key-type)
        |     |        +--:(symmetric-key-ref)
        |     |        |  +---w symmetric-key-ref?    leafref
        |     |        |          {keystore-supported}?
        |     |        +--:(asymmetric-key-ref)
        |     |           +---w asymmetric-key-ref?   leafref
        |     |                   {keystore-supported}?
        |     +--ro output
        |        +--ro algorithm
        |        |       iasa:asymmetric-algorithm-type
        |        +--ro public-key-format?             identityref
        |        +--ro public-key                     binary
        |        +--ro private-key-format?            identityref
        |        +--ro (private-key-type)
        |           +--:(private-key)
        |           |  +--ro private-key?             binary
        |           +--:(hidden-private-key)
        |           |  +--ro hidden-private-key?      empty
        |           +--:(encrypted-private-key)
        |              +--ro encrypted-private-key
        |                 +--ro (key-type)
        |                 |  +--:(symmetric-key-ref)
        |                 |  |  +--ro symmetric-key-ref?    leafref
        |                 |  |          {keystore-supported}?
        |                 |  +--:(asymmetric-key-ref)
        |                 |     +--ro asymmetric-key-ref?   leafref
        |                 |             {keystore-supported}?
        |                 +--ro value?                      binary
        +--rw symmetric-keys
           +--rw symmetric-key* [name]
           |  +--rw name                   string
           |  +--rw algorithm              isa:symmetric-algorithm-type
           |  +--rw key-format?            identityref
           |  +--rw (key-type)
           |     +--:(key)
           |     |  +--rw key?             binary
           |     +--:(hidden-key)
           |     |  +--rw hidden-key?      empty
           |     +--:(encrypted-key)

Watsen                    Expires May 23, 2020                  [Page 5]
Internet-Draft      A YANG Data Model for a Keystore       November 2019

           |        +--rw encrypted-key
           |           +--rw (key-type)
           |           |  +--:(symmetric-key-ref)
           |           |  |  +--rw symmetric-key-ref?    leafref
           |           |  |          {keystore-supported}?
           |           |  +--:(asymmetric-key-ref)
           |           |     +--rw asymmetric-key-ref?   leafref
           |           |             {keystore-supported}?
           |           +--rw value?                      binary
           +---x generate-symmetric-key
              +---w input
              |  +---w algorithm       isa:symmetric-algorithm-type
              |  +---w encrypt-with!
              |     +---w (key-type)
              |        +--:(symmetric-key-ref)
              |        |  +---w symmetric-key-ref?    leafref
              |        |          {keystore-supported}?
              |        +--:(asymmetric-key-ref)
              |           +---w asymmetric-key-ref?   leafref
              |                   {keystore-supported}?
              +--ro output
                 +--ro algorithm
                 |       isa:symmetric-algorithm-type
                 +--ro key-format?            identityref
                 +--ro (key-type)
                    +--:(key)
                    |  +--ro key?             binary
                    +--:(hidden-key)
                    |  +--ro hidden-key?      empty
                    +--:(encrypted-key)
                       +--ro encrypted-key
                          +--ro (key-type)
                          |  +--:(symmetric-key-ref)
                          |  |  +--ro symmetric-key-ref?    leafref
                          |  |          {keystore-supported}?
                          |  +--:(asymmetric-key-ref)
                          |     +--ro asymmetric-key-ref?   leafref
                          |             {keystore-supported}?
                          +--ro value?                      binary

     grouping key-reference-type-grouping
       +-- (key-type)
          +--:(symmetric-key-ref)
          |  +-- symmetric-key-ref?
          |          -> /keystore/symmetric-keys/symmetric-key/name
          |          {keystore-supported}?
          +--:(asymmetric-key-ref)
             +-- asymmetric-key-ref?

Watsen                    Expires May 23, 2020                  [Page 6]
Internet-Draft      A YANG Data Model for a Keystore       November 2019

                     -> /keystore/asymmetric-keys/asymmetric-key/name
                     {keystore-supported}?
     grouping encrypted-value-grouping
       +-- (key-type)
       |  +--:(symmetric-key-ref)
       |  |  +-- symmetric-key-ref?
       |  |          -> /keystore/symmetric-keys/symmetric-key/name
       |  |          {keystore-supported}?
       |  +--:(asymmetric-key-ref)
       |     +-- asymmetric-key-ref?
       |             -> /keystore/asymmetric-keys/asymmetric-key/name
       |             {keystore-supported}?
       +-- value?                      binary
     grouping symmetric-key-grouping
       +-- algorithm              isa:symmetric-algorithm-type
       +-- key-format?            identityref
       +-- (key-type)
          +--:(key)
          |  +-- key?             binary
          +--:(hidden-key)
          |  +-- hidden-key?      empty
          +--:(encrypted-key)
             +-- encrypted-key
                +-- (key-type)
                |  +--:(symmetric-key-ref)
                |  |  +-- symmetric-key-ref?    leafref
                |  |          {keystore-supported}?
                |  +--:(asymmetric-key-ref)
                |     +-- asymmetric-key-ref?   leafref
                |             {keystore-supported}?
                +-- value?                      binary
     grouping asymmetric-key-pair-grouping
       +-- algorithm                      iasa:asymmetric-algorithm-type
       +-- public-key-format?             identityref
       +-- public-key                     binary
       +-- private-key-format?            identityref
       +-- (private-key-type)
          +--:(private-key)
          |  +-- private-key?             binary
          +--:(hidden-private-key)
          |  +-- hidden-private-key?      empty
          +--:(encrypted-private-key)
             +-- encrypted-private-key
                +-- (key-type)
                |  +--:(symmetric-key-ref)
                |  |  +-- symmetric-key-ref?    leafref
                |  |          {keystore-supported}?
                |  +--:(asymmetric-key-ref)

Watsen                    Expires May 23, 2020                  [Page 7]
Internet-Draft      A YANG Data Model for a Keystore       November 2019

                |     +-- asymmetric-key-ref?   leafref
                |             {keystore-supported}?
                +-- value?                      binary
     grouping asymmetric-key-pair-with-cert-grouping
       +-- algorithm
       |       iasa:asymmetric-algorithm-type
       +-- public-key-format?                      identityref
       +-- public-key                              binary
       +-- private-key-format?                     identityref
       +-- (private-key-type)
       |  +--:(private-key)
       |  |  +-- private-key?                      binary
       |  +--:(hidden-private-key)
       |  |  +-- hidden-private-key?               empty
       |  +--:(encrypted-private-key)
       |     +-- encrypted-private-key
       |        +-- (key-type)
       |        |  +--:(symmetric-key-ref)
       |        |  |  +-- symmetric-key-ref?    leafref
       |        |  |          {keystore-supported}?
       |        |  +--:(asymmetric-key-ref)
       |        |     +-- asymmetric-key-ref?   leafref
       |        |             {keystore-supported}?
       |        +-- value?                      binary
       +-- cert?                                   end-entity-cert-cms
       +---n certificate-expiration
       |  +-- expiration-date    yang:date-and-time
       +---x generate-certificate-signing-request
          +---w input
          |  +---w subject       binary
          |  +---w attributes?   binary
          +--ro output
             +--ro certificate-signing-request    binary
     grouping asymmetric-key-pair-with-certs-grouping
       +-- algorithm
       |       iasa:asymmetric-algorithm-type
       +-- public-key-format?                      identityref
       +-- public-key                              binary
       +-- private-key-format?                     identityref
       +-- (private-key-type)
       |  +--:(private-key)
       |  |  +-- private-key?                      binary
       |  +--:(hidden-private-key)
       |  |  +-- hidden-private-key?               empty
       |  +--:(encrypted-private-key)
       |     +-- encrypted-private-key
       |        +-- (key-type)
       |        |  +--:(symmetric-key-ref)

Watsen                    Expires May 23, 2020                  [Page 8]
Internet-Draft      A YANG Data Model for a Keystore       November 2019

       |        |  |  +-- symmetric-key-ref?    leafref
       |        |  |          {keystore-supported}?
       |        |  +--:(asymmetric-key-ref)
       |        |     +-- asymmetric-key-ref?   leafref
       |        |             {keystore-supported}?
       |        +-- value?                      binary
       +-- certificates
       |  +-- certificate* [name]
       |     +-- name?                     string
       |     +-- cert?                     end-entity-cert-cms
       |     +---n certificate-expiration
       |        +-- expiration-date    yang:date-and-time
       +---x generate-certificate-signing-request
          +---w input
          |  +---w subject       binary
          |  +---w attributes?   binary
          +--ro output
             +--ro certificate-signing-request    binary
     grouping asymmetric-key-certificate-ref-grouping
       +-- asymmetric-key?   ks:asymmetric-key-ref
       +-- certificate?      leafref
     grouping local-or-keystore-symmetric-key-grouping
       +-- (local-or-keystore)
          +--:(local) {local-definitions-supported}?
          |  +-- local-definition
          |     +-- algorithm              isa:symmetric-algorithm-type
          |     +-- key-format?            identityref
          |     +-- (key-type)
          |        +--:(key)
          |        |  +-- key?             binary
          |        +--:(hidden-key)
          |        |  +-- hidden-key?      empty
          |        +--:(encrypted-key)
          |           +-- encrypted-key
          |              +-- (key-type)
          |              |  +--:(symmetric-key-ref)
          |              |  |  +-- symmetric-key-ref?    leafref
          |              |  |          {keystore-supported}?
          |              |  +--:(asymmetric-key-ref)
          |              |     +-- asymmetric-key-ref?   leafref
          |              |             {keystore-supported}?
          |              +-- value?                      binary
          +--:(keystore) {keystore-supported}?
             +-- keystore-reference?   ks:symmetric-key-ref
     grouping local-or-keystore-asymmetric-key-grouping
       +-- (local-or-keystore)
          +--:(local) {local-definitions-supported}?
          |  +-- local-definition

Watsen                    Expires May 23, 2020                  [Page 9]
Internet-Draft      A YANG Data Model for a Keystore       November 2019

          |     +-- algorithm
          |     |       iasa:asymmetric-algorithm-type
          |     +-- public-key-format?             identityref
          |     +-- public-key                     binary
          |     +-- private-key-format?            identityref
          |     +-- (private-key-type)
          |        +--:(private-key)
          |        |  +-- private-key?             binary
          |        +--:(hidden-private-key)
          |        |  +-- hidden-private-key?      empty
          |        +--:(encrypted-private-key)
          |           +-- encrypted-private-key
          |              +-- (key-type)
          |              |  +--:(symmetric-key-ref)
          |              |  |  +-- symmetric-key-ref?    leafref
          |              |  |          {keystore-supported}?
          |              |  +--:(asymmetric-key-ref)
          |              |     +-- asymmetric-key-ref?   leafref
          |              |             {keystore-supported}?
          |              +-- value?                      binary
          +--:(keystore) {keystore-supported}?
             +-- keystore-reference?   ks:asymmetric-key-ref
     grouping local-or-keystore-asymmetric-key-with-certs-grouping
       +-- (local-or-keystore)
          +--:(local) {local-definitions-supported}?
          |  +-- local-definition
          |     +-- algorithm
          |     |       iasa:asymmetric-algorithm-type
          |     +-- public-key-format?                      identityref
          |     +-- public-key                              binary
          |     +-- private-key-format?                     identityref
          |     +-- (private-key-type)
          |     |  +--:(private-key)
          |     |  |  +-- private-key?                      binary
          |     |  +--:(hidden-private-key)
          |     |  |  +-- hidden-private-key?               empty
          |     |  +--:(encrypted-private-key)
          |     |     +-- encrypted-private-key
          |     |        +-- (key-type)
          |     |        |  +--:(symmetric-key-ref)
          |     |        |  |  +-- symmetric-key-ref?    leafref
          |     |        |  |          {keystore-supported}?
          |     |        |  +--:(asymmetric-key-ref)
          |     |        |     +-- asymmetric-key-ref?   leafref
          |     |        |             {keystore-supported}?
          |     |        +-- value?                      binary
          |     +-- certificates
          |     |  +-- certificate* [name]

Watsen                    Expires May 23, 2020                 [Page 10]
Internet-Draft      A YANG Data Model for a Keystore       November 2019

          |     |     +-- name?                     string
          |     |     +-- cert?                     end-entity-cert-cms
          |     |     +---n certificate-expiration
          |     |        +-- expiration-date    yang:date-and-time
          |     +---x generate-certificate-signing-request
          |        +---w input
          |        |  +---w subject       binary
          |        |  +---w attributes?   binary
          |        +--ro output
          |           +--ro certificate-signing-request    binary
          +--:(keystore) {keystore-supported}?
             +-- keystore-reference?   ks:asymmetric-key-ref
     grouping local-or-keystore-end-entity-cert-with-key-grouping
       +-- (local-or-keystore)
          +--:(local) {local-definitions-supported}?
          |  +-- local-definition
          |     +-- algorithm
          |     |       iasa:asymmetric-algorithm-type
          |     +-- public-key-format?                      identityref
          |     +-- public-key                              binary
          |     +-- private-key-format?                     identityref
          |     +-- (private-key-type)
          |     |  +--:(private-key)
          |     |  |  +-- private-key?                      binary
          |     |  +--:(hidden-private-key)
          |     |  |  +-- hidden-private-key?               empty
          |     |  +--:(encrypted-private-key)
          |     |     +-- encrypted-private-key
          |     |        +-- (key-type)
          |     |        |  +--:(symmetric-key-ref)
          |     |        |  |  +-- symmetric-key-ref?    leafref
          |     |        |  |          {keystore-supported}?
          |     |        |  +--:(asymmetric-key-ref)
          |     |        |     +-- asymmetric-key-ref?   leafref
          |     |        |             {keystore-supported}?
          |     |        +-- value?                      binary
          |     +-- cert?
          |     |       end-entity-cert-cms
          |     +---n certificate-expiration
          |     |  +-- expiration-date    yang:date-and-time
          |     +---x generate-certificate-signing-request
          |        +---w input
          |        |  +---w subject       binary
          |        |  +---w attributes?   binary
          |        +--ro output
          |           +--ro certificate-signing-request    binary
          +--:(keystore) {keystore-supported}?
             +-- keystore-reference

Watsen                    Expires May 23, 2020                 [Page 11]
Internet-Draft      A YANG Data Model for a Keystore       November 2019

                +-- asymmetric-key?   ks:asymmetric-key-ref
                +-- certificate?      leafref
     grouping keystore-grouping
       +-- asymmetric-keys
       |  +-- asymmetric-key* [name]
       |  |  +-- name?                                   string
       |  |  +-- algorithm
       |  |  |       iasa:asymmetric-algorithm-type
       |  |  +-- public-key-format?                      identityref
       |  |  +-- public-key                              binary
       |  |  +-- private-key-format?                     identityref
       |  |  +-- (private-key-type)
       |  |  |  +--:(private-key)
       |  |  |  |  +-- private-key?                      binary
       |  |  |  +--:(hidden-private-key)
       |  |  |  |  +-- hidden-private-key?               empty
       |  |  |  +--:(encrypted-private-key)
       |  |  |     +-- encrypted-private-key
       |  |  |        +-- (key-type)
       |  |  |        |  +--:(symmetric-key-ref)
       |  |  |        |  |  +-- symmetric-key-ref?    leafref
       |  |  |        |  |          {keystore-supported}?
       |  |  |        |  +--:(asymmetric-key-ref)
       |  |  |        |     +-- asymmetric-key-ref?   leafref
       |  |  |        |             {keystore-supported}?
       |  |  |        +-- value?                      binary
       |  |  +-- certificates
       |  |  |  +-- certificate* [name]
       |  |  |     +-- name?                     string
       |  |  |     +-- cert?                     end-entity-cert-cms
       |  |  |     +---n certificate-expiration
       |  |  |        +-- expiration-date    yang:date-and-time
       |  |  +---x generate-certificate-signing-request
       |  |     +---w input
       |  |     |  +---w subject       binary
       |  |     |  +---w attributes?   binary
       |  |     +--ro output
       |  |        +--ro certificate-signing-request    binary
       |  +---x generate-asymmetric-key
       |     +---w input
       |     |  +---w algorithm       iasa:asymmetric-algorithm-type
       |     |  +---w encrypt-with!
       |     |     +---w (key-type)
       |     |        +--:(symmetric-key-ref)
       |     |        |  +---w symmetric-key-ref?    leafref
       |     |        |          {keystore-supported}?
       |     |        +--:(asymmetric-key-ref)
       |     |           +---w asymmetric-key-ref?   leafref

Watsen                    Expires May 23, 2020                 [Page 12]
Internet-Draft      A YANG Data Model for a Keystore       November 2019

       |     |                   {keystore-supported}?
       |     +--ro output
       |        +--ro algorithm
       |        |       iasa:asymmetric-algorithm-type
       |        +--ro public-key-format?             identityref
       |        +--ro public-key                     binary
       |        +--ro private-key-format?            identityref
       |        +--ro (private-key-type)
       |           +--:(private-key)
       |           |  +--ro private-key?             binary
       |           +--:(hidden-private-key)
       |           |  +--ro hidden-private-key?      empty
       |           +--:(encrypted-private-key)
       |              +--ro encrypted-private-key
       |                 +--ro (key-type)
       |                 |  +--:(symmetric-key-ref)
       |                 |  |  +--ro symmetric-key-ref?    leafref
       |                 |  |          {keystore-supported}?
       |                 |  +--:(asymmetric-key-ref)
       |                 |     +--ro asymmetric-key-ref?   leafref
       |                 |             {keystore-supported}?
       |                 +--ro value?                      binary
       +-- symmetric-keys
          +-- symmetric-key* [name]
          |  +-- name?                  string
          |  +-- algorithm              isa:symmetric-algorithm-type
          |  +-- key-format?            identityref
          |  +-- (key-type)
          |     +--:(key)
          |     |  +-- key?             binary
          |     +--:(hidden-key)
          |     |  +-- hidden-key?      empty
          |     +--:(encrypted-key)
          |        +-- encrypted-key
          |           +-- (key-type)
          |           |  +--:(symmetric-key-ref)
          |           |  |  +-- symmetric-key-ref?    leafref
          |           |  |          {keystore-supported}?
          |           |  +--:(asymmetric-key-ref)
          |           |     +-- asymmetric-key-ref?   leafref
          |           |             {keystore-supported}?
          |           +-- value?                      binary
          +---x generate-symmetric-key
             +---w input
             |  +---w algorithm       isa:symmetric-algorithm-type
             |  +---w encrypt-with!
             |     +---w (key-type)
             |        +--:(symmetric-key-ref)

Watsen                    Expires May 23, 2020                 [Page 13]
Internet-Draft      A YANG Data Model for a Keystore       November 2019

             |        |  +---w symmetric-key-ref?    leafref
             |        |          {keystore-supported}?
             |        +--:(asymmetric-key-ref)
             |           +---w asymmetric-key-ref?   leafref
             |                   {keystore-supported}?
             +--ro output
                +--ro algorithm
                |       isa:symmetric-algorithm-type
                +--ro key-format?            identityref
                +--ro (key-type)
                   +--:(key)
                   |  +--ro key?             binary
                   +--:(hidden-key)
                   |  +--ro hidden-key?      empty
                   +--:(encrypted-key)
                      +--ro encrypted-key
                         +--ro (key-type)
                         |  +--:(symmetric-key-ref)
                         |  |  +--ro symmetric-key-ref?    leafref
                         |  |          {keystore-supported}?
                         |  +--:(asymmetric-key-ref)
                         |     +--ro asymmetric-key-ref?   leafref
                         |             {keystore-supported}?
                         +--ro value?                      binary

3.2.  Example Usage

3.2.1.  A Keystore Instance

   The following example illustrates keys in <intended>.  Please see
   Section 4 for an example illustrating built-in values in
   <operational>.

   ========== NOTE: '\' line wrapping per BCP XXX (RFC XXXX) ===========

   <keystore xmlns="urn:ietf:params:xml:ns:yang:ietf-keystore"
     xmlns:ct="urn:ietf:params:xml:ns:yang:ietf-crypto-types">
     <symmetric-keys>

       <symmetric-key>
         <name>cleartext-symmetric-key</name>
         <algorithm>aes-256-cbc</algorithm>
         <key-format>ct:octet-string-key-format</key-format>
         <key>base64encodedvalue==</key>
       </symmetric-key>

       <symmetric-key>
         <name>hidden-symmetric-key</name>

Watsen                    Expires May 23, 2020                 [Page 14]
Internet-Draft      A YANG Data Model for a Keystore       November 2019

         <algorithm>aes-256-cbc</algorithm>
         <hidden-key/>
       </symmetric-key>

       <symmetric-key>
         <name>encrypted-symmetric-key</name> <!-- operator's key -->
         <algorithm>aes-256-cbc</algorithm>
         <key-format>ct:encrypted-one-symmetric-key-format</key-format>
         <encrypted-key>
           <asymmetric-key-ref>hidden-asymmetric-key</asymmetric-key-re\
   f>
           <value>base64encodedvalue==</value>
         </encrypted-key>
       </symmetric-key>

     </symmetric-keys>
     <asymmetric-keys>

       <asymmetric-key>
         <name>rsa-asymmetric-key</name>
         <algorithm>rsa2048</algorithm>
         <public-key-format>ct:subject-public-key-info-format</public-k\
   ey-format>
         <public-key>base64encodedvalue==</public-key>
         <private-key-format>ct:rsa-private-key-format</private-key-for\
   mat>
         <private-key>base64encodedvalue==</private-key>
         <certificates>
           <certificate>
             <name>ex-rsa-cert</name>
             <cert>base64encodedvalue==</cert>
           </certificate>
         </certificates>
       </asymmetric-key>

       <asymmetric-key>
         <name>ec-asymmetric-key</name>
         <algorithm>secp256r1</algorithm>
         <public-key-format>ct:subject-public-key-info-format</public-k\
   ey-format>
         <public-key>base64encodedvalue==</public-key>
         <private-key-format>ct:ec-private-key-format</private-key-form\
   at>
         <private-key>base64encodedvalue==</private-key>
         <certificates>
           <certificate>
             <name>ex-ec-cert</name>
             <cert>base64encodedvalue==</cert>

Watsen                    Expires May 23, 2020                 [Page 15]
Internet-Draft      A YANG Data Model for a Keystore       November 2019

           </certificate>
         </certificates>
       </asymmetric-key>

       <asymmetric-key>
         <name>hidden-asymmetric-key</name>
         <algorithm>rsa2048</algorithm>
         <public-key-format>ct:subject-public-key-info-format</public-k\
   ey-format>
         <public-key>base64encodedvalue==</public-key>
         <hidden-private-key/> <!-- e.g., TPM protected -->
         <certificates>
           <certificate>
             <name>builtin-idevid-cert</name>
           </certificate>
           <certificate>
             <name>my-ldevid-cert</name>
             <cert>base64encodedvalue==</cert>
           </certificate>
         </certificates>
       </asymmetric-key>

       <asymmetric-key>
         <name>encrypted-asymmetric-key</name>
         <algorithm>secp256r1</algorithm>
         <public-key-format>ct:subject-public-key-info-format</public-k\
   ey-format>
         <public-key>base64encodedvalue==</public-key>
         <private-key-format>ct:encrypted-one-asymmetric-key-format</pr\
   ivate-key-format>
         <encrypted-private-key>
           <symmetric-key-ref>encrypted-symmetric-key</symmetric-key-re\
   f>
           <value>base64encodedvalue==</value>
         </encrypted-private-key>
       </asymmetric-key>

     </asymmetric-keys>
   </keystore>

3.2.2.  The "generate-symmetric-key" RPC

   The following example illustrates the "generate-symmetric-key" RPC.
   The key being referenced is defined in the keystore example above.

Watsen                    Expires May 23, 2020                 [Page 16]
Internet-Draft      A YANG Data Model for a Keystore       November 2019

   ========== NOTE: '\' line wrapping per BCP XXX (RFC XXXX) ===========

   <rpc message-id="101"
     xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
     <action xmlns="urn:ietf:params:xml:ns:yang:1">
       <keystore xmlns="urn:ietf:params:xml:ns:yang:ietf-keystore">
         <symmetric-keys>
           <generate-symmetric-key>
             <algorithm>aes-256-cbc</algorithm>
             <encrypt-with>
               <asymmetric-key-ref>hidden-asymmetric-key</asymmetric-ke\
   y-ref>
             </encrypt-with>
           </generate-symmetric-key>
         </symmetric-keys>
       </keystore>
     </action>
   </rpc>

   Following is the complimentary RPC-reply.

   ========== NOTE: '\' line wrapping per BCP XXX (RFC XXXX) ===========

   <rpc-reply message-id="101"
     xmlns="urn:ietf:params:xml:ns:netconf:base:1.0"
     xmlns:ks="urn:ietf:params:xml:ns:yang:ietf-keystore"
     xmlns:ct="urn:ietf:params:xml:ns:yang:ietf-crypto-types">
     <!--<data> yanglint validation fails -->
       <ks:algorithm>aes-256-cbc</ks:algorithm>
       <ks:key-format>ct:encrypted-one-symmetric-key-format</ks:key-for\
   mat>
       <ks:encrypted-key>
         <ks:asymmetric-key-ref>hidden-asymmetric-key</ks:asymmetric-ke\
   y-ref>
         <ks:value>base64encodedvalue==</ks:value>
       </ks:encrypted-key>
     <!--</data> yanglint validation fails -->
   </rpc-reply>

3.2.3.  The "generate-asymmetric-key" RPC

   The following example illustrates the "generate-asymmetric-key" RPC.
   The key being referenced is defined in the keystore example above.

Watsen                    Expires May 23, 2020                 [Page 17]
Internet-Draft      A YANG Data Model for a Keystore       November 2019

   ========== NOTE: '\' line wrapping per BCP XXX (RFC XXXX) ===========

   <rpc message-id="101"
     xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
     <action xmlns="urn:ietf:params:xml:ns:yang:1">
       <keystore xmlns="urn:ietf:params:xml:ns:yang:ietf-keystore">
         <asymmetric-keys>
           <generate-asymmetric-key>
             <algorithm>secp256r1</algorithm>
             <encrypt-with>
               <symmetric-key-ref>encrypted-symmetric-key</symmetric-ke\
   y-ref>
             </encrypt-with>
           </generate-asymmetric-key>
         </asymmetric-keys>
       </keystore>
     </action>
   </rpc>

   Following is the complimentary RPC-reply.

   ========== NOTE: '\' line wrapping per BCP XXX (RFC XXXX) ===========

   <rpc-reply message-id="101"
     xmlns="urn:ietf:params:xml:ns:netconf:base:1.0"
     xmlns:ks="urn:ietf:params:xml:ns:yang:ietf-keystore"
     xmlns:ct="urn:ietf:params:xml:ns:yang:ietf-crypto-types">
     <!--<data> yanglint validation fails -->
       <ks:algorithm>secp256r1</ks:algorithm>
       <ks:public-key-format>ct:subject-public-key-info-format</ks:publ\
   ic-key-format>
       <ks:public-key>base64encodedvalue==</ks:public-key>
       <ks:private-key-format>ct:encrypted-one-asymmetric-key-format</k\
   s:private-key-format>
       <ks:encrypted-private-key>
         <ks:symmetric-key-ref>encrypted-symmetric-key</ks:symmetric-ke\
   y-ref>
         <ks:value>base64encodedvalue==</ks:value>
       </ks:encrypted-private-key>
     <!--</data> yanglint validation fails -->
   </rpc-reply>

3.2.4.  Notable Keystore Groupings

   The following non-normative module is used by subsequent examples to
   illustrate groupings defined in the ietf-crypto-types module.

   module ex-keystore-usage {

Watsen                    Expires May 23, 2020                 [Page 18]
Internet-Draft      A YANG Data Model for a Keystore       November 2019

     yang-version 1.1;

     namespace "http://example.com/ns/example-keystore-usage";
     prefix "eku";

     import ietf-keystore {
       prefix ks;
       reference
         "RFC XXXX: YANG Data Model for a 'Keystore' Mechanism";
     }

     organization
      "Example Corporation";

     contact
      "Author: YANG Designer <mailto:yang.designer@example.com>";

     description
      "This module illustrates the grouping in the keystore draft called
       'local-or-keystore-asymmetric-key-with-certs-grouping'.";

     revision "YYYY-MM-DD" {
       description
        "Initial version";
       reference
        "RFC XXXX: YANG Data Model for a 'Keystore' Mechanism";
     }

     container keystore-usage {
       description
         "An illustration of the various keystore groupings.";

       list just-a-key {
         key name;
         leaf name {
           type string;
           description
             "An arbitrary name for this key.";
         }
         uses ks:local-or-keystore-asymmetric-key-grouping;
         description
           "An asymmetric key, with no certs, that may be configured
            locally or be a reference to an asymmetric key in the
            keystore.  The intent is to reference just the asymmetric
            key, not any certificates that may also be associated
            with the asymmetric key.";
       }

Watsen                    Expires May 23, 2020                 [Page 19]
Internet-Draft      A YANG Data Model for a Keystore       November 2019

       list key-with-certs {
         key name;
         leaf name {
           type string;
           description
             "An arbitrary name for this key.";
         }
         uses ks:local-or-keystore-asymmetric-key-with-certs-grouping;
         description
           "An asymmetric key and its associated certs, that may be
            configured locally or be a reference to an asymmetric key
            (and its associated certs) in the keystore.";
       }

       list end-entity-cert-with-key {
         key name;
         leaf name {
           type string;
           description
             "An arbitrary name for this key.";
         }
         uses ks:local-or-keystore-end-entity-cert-with-key-grouping;
         description
           "An end-entity certificate, and its associated private key,
            that may be configured locally or be a reference to a
            specific certificate (and its associated private key) in
            the keystore.";
       }
     }

   }

   The following example illustrates what two configured keys, one local
   and the other remote, might look like.  This example consistent with
   other examples above (i.e., the referenced key is in an example
   above).

   ========== NOTE: '\' line wrapping per BCP XXX (RFC XXXX) ===========

   <keystore-usage xmlns="http://example.com/ns/example-keystore-usage"
     xmlns:ct="urn:ietf:params:xml:ns:yang:ietf-crypto-types">

     <!-- ks:local-or-keystore-asymmetric-key-grouping -->

     <just-a-key>
       <name>a locally-defined key</name>
       <local-definition>
         <algorithm>rsa2048</algorithm>

Watsen                    Expires May 23, 2020                 [Page 20]
Internet-Draft      A YANG Data Model for a Keystore       November 2019

         <public-key-format>ct:subject-public-key-info-format</public-k\
   ey-format>
         <public-key>base64encodedvalue==</public-key>
         <private-key-format>ct:rsa-private-key-format</private-key-for\
   mat>
         <private-key>base64encodedvalue==</private-key>
       </local-definition>
     </just-a-key>

     <just-a-key>
       <name>a keystore-defined key (and its associated certs)</name>
       <keystore-reference>rsa-asymmetric-key</keystore-reference>
     </just-a-key>

     <!-- ks:local-or-keystore-key-and-end-entity-cert-grouping -->

     <key-with-certs>
       <name>a locally-defined key with certs</name>
       <local-definition>
         <algorithm>rsa2048</algorithm>
         <public-key-format>ct:subject-public-key-info-format</public-k\
   ey-format>
         <public-key>base64encodedvalue==</public-key>
         <private-key-format>ct:rsa-private-key-format</private-key-for\
   mat>
         <private-key>base64encodedvalue==</private-key>
         <certificates>
           <certificate>
             <name>a locally-defined cert</name>
             <cert>base64encodedvalue==</cert>
           </certificate>
         </certificates>
       </local-definition>
     </key-with-certs>

     <key-with-certs>
       <name>a keystore-defined key (and its associated certs)</name>
       <keystore-reference>rsa-asymmetric-key</keystore-reference>
     </key-with-certs>

     <!-- ks:local-or-keystore-end-entity-cert-with-key-grouping -->

     <end-entity-cert-with-key>
       <name>a locally-defined end-entity cert with key</name>
       <local-definition>
         <algorithm>rsa2048</algorithm>
         <public-key-format>ct:subject-public-key-info-format</public-k\
   ey-format>

Watsen                    Expires May 23, 2020                 [Page 21]
Internet-Draft      A YANG Data Model for a Keystore       November 2019

         <public-key>base64encodedvalue==</public-key>
         <private-key-format>ct:rsa-private-key-format</private-key-for\
   mat>
         <private-key>base64encodedvalue==</private-key>
         <cert>base64encodedvalue==</cert>
       </local-definition>
     </end-entity-cert-with-key>

     <end-entity-cert-with-key>
       <name>a keystore-defined certificate (and its associated key)</n\
   ame>
       <keystore-reference>
         <asymmetric-key>rsa-asymmetric-key</asymmetric-key>
         <certificate>ex-rsa-cert</certificate>
       </keystore-reference>
     </end-entity-cert-with-key>

   </keystore-usage>

3.3.  YANG Module

   This YANG module has normative references to [RFC8341] and
   [I-D.ietf-netconf-crypto-types], and an informative reference to
   [RFC8342].

   <CODE BEGINS> file "ietf-keystore@2019-11-20.yang"

   module ietf-keystore {
     yang-version 1.1;
     namespace "urn:ietf:params:xml:ns:yang:ietf-keystore";
     prefix ks;

     import ietf-netconf-acm {
       prefix nacm;
       reference
         "RFC 8341: Network Configuration Access Control Model";
     }

     import ietf-crypto-types {
       prefix ct;
       reference
         "RFC AAAA: Common YANG Data Types for Cryptography";
     }

     //import iana-hash-algs {
     //  prefix iha;
     //  reference
     //    "RFC AAAA: Common YANG Data Types for Cryptography";

Watsen                    Expires May 23, 2020                 [Page 22]
Internet-Draft      A YANG Data Model for a Keystore       November 2019

     //}

     import iana-symmetric-algs {
       prefix isa;
       reference
         "RFC AAAA: Common YANG Data Types for Cryptography";
     }

     import iana-asymmetric-algs {
       prefix iasa;
       reference
         "RFC AAAA: Common YANG Data Types for Cryptography";
     }

     organization
       "IETF NETCONF (Network Configuration) Working Group";

     contact
       "WG Web:   <http://datatracker.ietf.org/wg/netconf/>
        WG List:  <mailto:netconf@ietf.org>
        Author:   Kent Watsen <mailto:kent+ietf@watsen.net>";

     description
       "This module defines a keystore to centralize management
        of security credentials.

        Copyright (c) 2019 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
        (https://trustee.ietf.org/license-info).

        This version of this YANG module is part of RFC XXXX
        (https://www.rfc-editor.org/info/rfcXXXX); see the RFC
        itself for full legal notices.

        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 (RFC 2119)
        (RFC 8174) when, and only when, they appear in all
        capitals, as shown here.";

     revision 2019-11-20 {

Watsen                    Expires May 23, 2020                 [Page 23]
Internet-Draft      A YANG Data Model for a Keystore       November 2019

       description
         "Initial version";
       reference
         "RFC XXXX: A YANG Data Model for a Keystore";
     }

     /****************/
     /*   Features   */
     /****************/

     feature keystore-supported {
       description
         "The 'keystore-supported' feature indicates that the server
          supports the keystore.";
     }

     feature local-definitions-supported {
       description
         "The 'local-definitions-supported' feature indicates that the
          server supports locally-defined keys.";
     }

     feature key-generation {
       description
         "Indicates that the server supports the actions related to
          the life cycling keys in <operational>.  To be used by
          configuration, keys in <operational> must be copied to
          <running>.";
     }

     /****************/
     /*   Typedefs   */
     /****************/

     typedef symmetric-key-ref {
       type leafref {
         path "/ks:keystore/ks:symmetric-keys/ks:symmetric-key"
            + "/ks:name";
       }
       description
         "This typedef enables modules to easily define a reference
          to a symmetric key stored in the keystore.";
     }

     typedef asymmetric-key-ref {
       type leafref {
         path "/ks:keystore/ks:asymmetric-keys/ks:asymmetric-key"
            + "/ks:name";

Watsen                    Expires May 23, 2020                 [Page 24]
Internet-Draft      A YANG Data Model for a Keystore       November 2019

       }
       description
         "This typedef enables modules to easily define a reference
          to an asymmetric key stored in the keystore.";
     }

     /*****************/
     /*   Groupings   */
     /*****************/

     grouping key-reference-type-grouping {
       description
         "A reusable grouping for a choice for the type of key
          referenced in the keystore.";
       choice key-type {
         mandatory true;
         description
           "A choice between a reference to a symmetric or asymmetric
            key in the keystore.";
         leaf symmetric-key-ref {
           if-feature "keystore-supported";
           type leafref {
             path "/ks:keystore/ks:symmetric-keys/ks:symmetric-key/"
                  + "ks:name";
           }
           description
             "Identifies a symmetric key used to encrypt this key.";
         }
         leaf asymmetric-key-ref {
           if-feature "keystore-supported";
           type leafref {
             path "/ks:keystore/ks:asymmetric-keys/ks:asymmetric-key/"
                  + "ks:name";
           }
           description
             "Identifies an asymmetric key used to encrypt this key.";
         }
       }
     }

     grouping encrypted-value-grouping {
       description
         "A reusable grouping for a value that has been encrypted by
          a symmetric or asymmetric key in the keystore.";
       uses "key-reference-type-grouping";
       leaf value {
         type binary;

Watsen                    Expires May 23, 2020                 [Page 25]
Internet-Draft      A YANG Data Model for a Keystore       November 2019

         description
           "The private key, encrypted using the specified symmetric
            or asymmetric key.";
       }
     }

     grouping symmetric-key-grouping {
       description
         "This grouping is identical to the one in ietf-crypto-types
          except that it adds a case statement enabling the key
          value to be encrypted by a symmetric or an asymmetric
          key known to the keystore.";
       uses ct:symmetric-key-grouping {
         augment "key-type" {
           description
             "Augments a new 'case' statement into the 'choice'
              statement defined by the ietf-crypto-types module.";
           container encrypted-key {
             must "../key-format";
             description
               "A container for the encrypted symmetric key value.";
             uses encrypted-value-grouping;
           }
         }
       }
     }

     grouping asymmetric-key-pair-grouping {
       description
         "This grouping is identical to the one in ietf-crypto-types
          except that it adds a case statement enabling the key
          value to be encrypted by a symmetric or an asymmetric
          key known to the keystore.";
       uses ct:asymmetric-key-pair-grouping {
         augment "private-key-type" {
           description
             "Augments a new 'case' statement into the 'choice'
              statement defined by the ietf-crypto-types module.";
           container encrypted-private-key {
             must "../private-key-format";
             description
               "A container for the encrypted asymmetric private
                key value.";
             uses encrypted-value-grouping;
           }
         }
       }
     }

Watsen                    Expires May 23, 2020                 [Page 26]
Internet-Draft      A YANG Data Model for a Keystore       November 2019

     grouping asymmetric-key-pair-with-cert-grouping {
       description
         "This grouping is identical to the one in ietf-crypto-types
          except that it adds a case statement enabling the key
          value to be encrypted by a symmetric or an asymmetric
          key known to the keystore.";
       uses ct:asymmetric-key-pair-with-cert-grouping {
         augment "private-key-type" {
           description
             "Augments a new 'case' statement into the 'choice'
              statement defined by the ietf-crypto-types module.";
           container encrypted-private-key {
             must "../private-key-format";
             description
               "A container for the encrypted asymmetric private
                key value.";
             uses encrypted-value-grouping;
           }
         }
       }
     }

     grouping asymmetric-key-pair-with-certs-grouping {
       description
         "This grouping is identical to the one in ietf-crypto-types
          except that it adds a case statement enabling the key
          value to be encrypted by a symmetric or an asymmetric
          key known to the keystore.";
       uses ct:asymmetric-key-pair-with-certs-grouping {
         augment "private-key-type" {
           description
             "Augments a new 'case' statement into the 'choice'
              statement defined by the ietf-crypto-types module.";
           container encrypted-private-key {
             must "../private-key-format";
             description
               "A container for the encrypted asymmetric private
                key value.";
             uses encrypted-value-grouping;
           }
         }
       }
     }

     grouping asymmetric-key-certificate-ref-grouping {
       leaf asymmetric-key {
         type ks:asymmetric-key-ref;
         must '../certificate';

Watsen                    Expires May 23, 2020                 [Page 27]
Internet-Draft      A YANG Data Model for a Keystore       November 2019

         description
           "A reference to an asymmetric key in the keystore.";
       }
       leaf certificate {
         type leafref {
           path "/ks:keystore/ks:asymmetric-keys/ks:asymmetric-key[ks:"
                + "name = current()/../asymmetric-key]/ks:certificates"
                + "/ks:certificate/ks:name";
         }
         must '../asymmetric-key';
         description
           "A reference to a specific certificate of the
            asymmetric key in the keystore.";
       }
       description
         "This grouping defines a reference to a specific certificate
          associated with an asymmetric key stored in the keystore.";
     }

     // local-or-keystore-* groupings

     grouping local-or-keystore-symmetric-key-grouping {
       description
         "A grouping that expands to allow the symmetric key to be
          either stored locally, within the using data model, or be
          a reference to an symmetric key stored in the keystore.";
       choice local-or-keystore {
         mandatory true;
         case local {
           if-feature "local-definitions-supported";
           container local-definition {
             description
               "Container to hold the local key definition.";
             uses symmetric-key-grouping;
           }
         }
         case keystore {
           if-feature "keystore-supported";
           leaf keystore-reference {
             type ks:symmetric-key-ref;
             description
               "A reference to an symmetric key that exists in
                the keystore.";
           }
         }
         description
           "A choice between an inlined definition and a definition

Watsen                    Expires May 23, 2020                 [Page 28]
Internet-Draft      A YANG Data Model for a Keystore       November 2019

            that exists in the keystore.";
       }
     }

     grouping local-or-keystore-asymmetric-key-grouping {
       description
         "A grouping that expands to allow the asymmetric key to be
          either stored locally, within the using data model, or be
          a reference to an asymmetric key stored in the keystore.";
       choice local-or-keystore {
         mandatory true;
         case local {
           if-feature "local-definitions-supported";
           container local-definition {
             description
               "Container to hold the local key definition.";
             uses asymmetric-key-pair-grouping;
           }
         }
         case keystore {
           if-feature "keystore-supported";
           leaf keystore-reference {
             type ks:asymmetric-key-ref;
             description
               "A reference to an asymmetric key that exists in
                the keystore.  The intent is to reference just the
                asymmetric key without any regard for any certificates
                that may be associated with it.";
           }
         }
         description
           "A choice between an inlined definition and a definition
            that exists in the keystore.";
       }
     }

     grouping local-or-keystore-asymmetric-key-with-certs-grouping {
       description
         "A grouping that expands to allow an asymmetric key and its
          associated certificates to be either stored locally, within
          the using data model, or be a reference to an asymmetric key
          (and its associated certificates) stored in the keystore.";
       choice local-or-keystore {
         mandatory true;
         case local {
           if-feature "local-definitions-supported";
           container local-definition {
             description

Watsen                    Expires May 23, 2020                 [Page 29]
Internet-Draft      A YANG Data Model for a Keystore       November 2019

               "Container to hold the local key definition.";
             uses asymmetric-key-pair-with-certs-grouping;
           }
         }
         case keystore {
           if-feature "keystore-supported";
           leaf keystore-reference {
             type ks:asymmetric-key-ref;
             description
               "A reference to an asymmetric-key (and all of its
                associated certificates) in the keystore.";
           }
         }
         description
           "A choice between an inlined definition and a definition
            that exists in the keystore.";
       }
     }

     grouping local-or-keystore-end-entity-cert-with-key-grouping {
       description
         "A grouping that expands to allow an end-entity certificate
          (and its associated private key) to be either stored locally,
          within the using data model, or be a reference to a specific
          certificate in the keystore.";
       choice local-or-keystore {
         mandatory true;
         case local {
           if-feature "local-definitions-supported";
           container local-definition {
             description
               "Container to hold the local key definition.";
             uses asymmetric-key-pair-with-cert-grouping;
           }
         }
         case keystore {
           if-feature "keystore-supported";
           container keystore-reference {
             uses asymmetric-key-certificate-ref-grouping;
             description
               "A reference to a specific certificate (and its
                associated private key) in the keystore.";
           }
         }
         description
           "A choice between an inlined definition and a definition
            that exists in the keystore.";
       }

Watsen                    Expires May 23, 2020                 [Page 30]
Internet-Draft      A YANG Data Model for a Keystore       November 2019

     }

     grouping keystore-grouping {
       description
         "Grouping definition enables use in other contexts.  If ever
          done, implementations SHOULD augment new 'case' statements
          into local-or-keystore 'choice' statements to supply leafrefs
          to the new location.";
       container asymmetric-keys {
         description
           "A list of asymmetric keys.";
         list asymmetric-key {
           key "name";
           description
             "An asymmetric key.";
           leaf name {
             type string;
             description
               "An arbitrary name for the asymmetric key.";
           }
           uses ks:asymmetric-key-pair-with-certs-grouping;
         }
         action generate-asymmetric-key {
           //nacm:default-deny-all;
           description
             "Requests the device to generate an asymmetric key using
              the specified key algorithm, optionally encrypted using
              a key in the keystore.  The output is this RPC can be
              used as input to a subsequent configuration request.";
           input {
             leaf algorithm {
               type iasa:asymmetric-algorithm-type;
               mandatory true;
               description
                 "The algorithm to be used when generating the key.";
               reference
                 "RFC AAAA: Common YANG Data Types for Cryptography";
             }
             container encrypt-with {
               presence
                 "Indicates that the key should be encrypted using
                  the specified symmetric or asymmetric key.  If not
                  specified, then the private key is not encrypted
                  when returned.";
               description
                 "A container for the 'key-type' choice.";
               uses key-reference-type-grouping;
             }

Watsen                    Expires May 23, 2020                 [Page 31]
Internet-Draft      A YANG Data Model for a Keystore       November 2019

           }
           output {
             uses ks:asymmetric-key-pair-grouping;
           }
         } // end generate-asymmetric-key
       }
       container symmetric-keys {
         description
           "A list of symmetric keys.";
         list symmetric-key {
           key "name";
           description
             "A symmetric key.";
           leaf name {
             type string;
             description
               "An arbitrary name for the symmetric key.";
           }
           uses ks:symmetric-key-grouping;
         }
         action generate-symmetric-key {
           //nacm:default-deny-all;
           description
             "Requests the device to generate an symmetric key using
              the specified key algorithm, optionally encrypted using
              a key in the keystore.  The output is this RPC can be
              used as input to a subsequent configuration request.";
           input {
             leaf algorithm {
               type isa:symmetric-algorithm-type;
               mandatory true;
               description
                 "The algorithm to be used when generating the key.";
               reference
                 "RFC AAAA: Common YANG Data Types for Cryptography";
             }
             container encrypt-with {
               presence
                 "Indicates that the key should be encrypted using
                  the specified symmetric or asymmetric key.  If not
                  specified, then the private key is not encrypted
                  when returned.";
               description
                 "A container for the 'key-type' choice.";
               uses key-reference-type-grouping;
             }
           }
           output {

Watsen                    Expires May 23, 2020                 [Page 32]
Internet-Draft      A YANG Data Model for a Keystore       November 2019

             uses ks:symmetric-key-grouping;
           }
         } // end generate-symmetric-key
       }
     } // grouping keystore-grouping

     /*********************************/
     /*   Protocol accessible nodes   */
     /*********************************/

     container keystore {
       nacm:default-deny-write;
       description
         "The keystore contains a list of keys.";
       uses keystore-grouping;
     }

   }

   <CODE ENDS>

4.  Support for Built-in Keys

   In some implementations, a device's hardware may define some built-in
   keys set during the manufacturing process, and/or the operating
   system the device runs may dynamically generate some "hidden" keys
   upon first boot.  As an example, a built-in key may exist in
   conjunction with a secure device identity certificate (e.g., an
   IDevID certificate).

   Built-in keys are expected to be set by a vendor-specific process.
   Any ability for operators to modify the built-in keys is outside the
   scope of this docuemnt.

   As built-in keys are provided by the system (not configuration), they
   are present in <operational>.  The following example illustrates
   built-in keys in <operational>.

   (FIXME: add illustration with origin="system" here)

   In order for the built-in keys to be referenced by configuration,
   they must first be copied into <intended> as the example in
   Section 3.2 illustrates for the built-in keys above.  Note that this
   strategy is chosen, rather then setting "require-instance false" for
   the various leafrefs, as built-in keys are relatively few in number
   and hence not worth relaxing the validation for.

Watsen                    Expires May 23, 2020                 [Page 33]
Internet-Draft      A YANG Data Model for a Keystore       November 2019

5.  Security Considerations

   The YANG module defined in this document is designed to be accessed
   via YANG based management protocols, such as NETCONF [RFC6241] and
   RESTCONF [RFC8040].  Both of these protocols have mandatory-to-
   implement secure transport layers (e.g., SSH, TLS) with mutual
   authentication.

   The NETCONF access control model (NACM) [RFC8341] provides the means
   to restrict access for particular users to a pre-configured subset of
   all available protocol operations and content.

   There are a number of data nodes defined in this YANG module that are
   writable/creatable/deletable (i.e., config true, which is the
   default).  These data nodes may be considered sensitive or vulnerable
   in some network environments.  Write operations (e.g., edit-config)
   to these data nodes without proper protection can have a negative
   effect on network operations.  These are the subtrees and data nodes
   and their sensitivity/vulnerability:

      /: The entire data tree defined by this module is sensitive to
         write operations.  For instance, the addition or removal of
         keys, certificates, etc., can dramatically alter the
         implemented security policy.  For this reason, the NACM
         extension "default-deny-write" has been set for the entire data
         tree.

      /keystore/asymmetric-keys/asymmetric-key/private-key:  When
         writing this node, implementations MUST ensure that the
         strength of the key being configured is not greater than the
         strength of the underlying secure transport connection over
         which it is communicated.  Implementations SHOULD fail the
         write-request if ever the strength of the private key is
         greater then the strength of the underlying transport, and
         alert the client that the strength of the key may have been
         compromised.  Additionally, when deleting this node,
         implementations SHOULD automatically (without explicit request)
         zeroize these keys in the most secure manner available, so as
         to prevent the remnants of their persisted storage locations
         from being analyzed in any meaningful way.

   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.  These are the subtrees and data
   nodes and their sensitivity/vulnerability:

Watsen                    Expires May 23, 2020                 [Page 34]
Internet-Draft      A YANG Data Model for a Keystore       November 2019

      /keystore/asymmetric-keys/asymmetric-key/private-key:  This node
         is additionally sensitive to read operations such that, in
         normal use cases, it should never be returned to a client.  The
         best reason for returning this node is to support backup/
         restore type workflows.  For this reason, the NACM extension
         "default-deny-all" has been set for this data node.

6.  IANA Considerations

6.1.  The IETF XML Registry

   This document registers one URI in the "ns" subregistry of the IETF
   XML Registry [RFC3688].  Following the format in [RFC3688], the
   following registration is requested:

      URI: urn:ietf:params:xml:ns:yang:ietf-keystore
      Registrant Contact: The NETCONF WG of the IETF.
      XML: N/A, the requested URI is an XML namespace.

6.2.  The YANG Module Names Registry

   This document registers one YANG module in the YANG Module Names
   registry [RFC6020].  Following the format in [RFC6020], the the
   following registration is requested:

      name:         ietf-keystore
      namespace:    urn:ietf:params:xml:ns:yang:ietf-keystore
      prefix:       ks
      reference:    RFC XXXX

7.  References

7.1.  Normative References

   [I-D.ietf-netconf-crypto-types]
              Watsen, K. and H. Wang, "Common YANG Data Types for
              Cryptography", draft-ietf-netconf-crypto-types-12 (work in
              progress), November 2019.

   [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>.

Watsen                    Expires May 23, 2020                 [Page 35]
Internet-Draft      A YANG Data Model for a Keystore       November 2019

   [RFC6020]  Bjorklund, M., Ed., "YANG - A Data Modeling Language for
              the Network Configuration Protocol (NETCONF)", RFC 6020,
              DOI 10.17487/RFC6020, October 2010,
              <https://www.rfc-editor.org/info/rfc6020>.

   [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>.

   [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>.

7.2.  Informative References

   [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>.

   [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>.

   [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>.

   [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>.

   [Std-802.1AR-2009]
              Group, W. -. H. L. L. P. W., "IEEE Standard for Local and
              metropolitan area networks - Secure Device Identity",
              December 2009, <http://standards.ieee.org/findstds/
              standard/802.1AR-2009.html>.

Watsen                    Expires May 23, 2020                 [Page 36]
Internet-Draft      A YANG Data Model for a Keystore       November 2019

Appendix A.  Change Log

A.1.  00 to 01

   o  Replaced the 'certificate-chain' structures with PKCS#7
      structures.  (Issue #1)

   o  Added 'private-key' as a configurable data node, and removed the
      'generate-private-key' and 'load-private-key' actions.  (Issue #2)

   o  Moved 'user-auth-credentials' to the ietf-ssh-client module.
      (Issues #4 and #5)

A.2.  01 to 02

   o  Added back 'generate-private-key' action.

   o  Removed 'RESTRICTED' enum from the 'private-key' leaf type.

   o  Fixed up a few description statements.

A.3.  02 to 03

   o  Changed draft's title.

   o  Added missing references.

   o  Collapsed sections and levels.

   o  Added RFC 8174 to Requirements Language Section.

   o  Renamed 'trusted-certificates' to 'pinned-certificates'.

   o  Changed 'public-key' from config false to config true.

   o  Switched 'host-key' from OneAsymmetricKey to definition from RFC
      4253.

A.4.  03 to 04

   o  Added typedefs around leafrefs to common keystore paths

   o  Now tree diagrams reference ietf-netmod-yang-tree-diagrams

   o  Removed Design Considerations section

   o  Moved key and certificate definitions from data tree to groupings

Watsen                    Expires May 23, 2020                 [Page 37]
Internet-Draft      A YANG Data Model for a Keystore       November 2019

A.5.  04 to 05

   o  Removed trust anchors (now in their own draft)

   o  Added back global keystore structure

   o  Added groupings enabling keys to either be locally defined or a
      reference to the keystore.

A.6.  05 to 06

   o  Added feature "local-keys-supported"

   o  Added nacm:default-deny-all and nacm:default-deny-write

   o  Renamed generate-asymmetric-key to generate-hidden-key

   o  Added an install-hidden-key action

   o  Moved actions inside fo the "asymmetric-key" container

   o  Moved some groupings to draft-ietf-netconf-crypto-types

A.7.  06 to 07

   o  Removed a "require-instance false"

   o  Clarified some description statements

   o  Improved the keystore-usage examples

A.8.  07 to 08

   o  Added "local-definition" containers to avoid posibility of the
      action/notification statements being under a "case" statement.

   o  Updated copyright date, boilerplate template, affiliation, folding
      algorithm, and reformatted the YANG module.

A.9.  08 to 09

   o  Added a 'description' statement to the 'must' in the /keystore/
      asymmetric-key node explaining that the descendent values may
      exist in <operational> only, and that implementation MUST assert
      that the values are either configured or that they exist in
      <operational>.

Watsen                    Expires May 23, 2020                 [Page 38]
Internet-Draft      A YANG Data Model for a Keystore       November 2019

   o  Copied above 'must' statement (and description) into the local-or-
      keystore-asymmetric-key-grouping, local-or-keystore-asymmetric-
      key-with-certs-grouping, and local-or-keystore-end-entity-cert-
      with-key-grouping statements.

A.10.  09 to 10

   o  Updated draft title to match new truststore draft title

   o  Moved everything under a top-level 'grouping' to enable use in
      other contexts.

   o  Renamed feature from 'local-keys-supported' to 'local-definitions-
      supported' (same name used in truststore)

   o  Removed the either-all-or-none 'must' expressions for the key's
      3-tuple values (since the values are now 'mandatory true' in
      crypto-types)

   o  Example updated to reflect 'mandatory true' change in crypto-types
      draft

A.11.  10 to 11

   o  Replaced typedef asymmetric-key-certificate-ref with grouping
      asymmetric-key-certificate-ref-grouping.

   o  Added feature feature 'key-generation'.

   o  Cloned groupings symmetric-key-grouping, asymmetric-key-pair-
      grouping, asymmetric-key-pair-with-cert-grouping, and asymmetric-
      key-pair-with-certs-grouping from crypto-keys, augmenting into
      each new case statements for values that have been encrypted by
      other keys in the keystore.  Refactored keystore model to use
      these groupings.

   o  Added new 'symmetric-keys' lists, as a sibling to the existing
      'asymmetric-keys' list.

   o  Added RPCs (not actions) 'generate-symmetric-key' and 'generate-
      asymmetric-key' to *return* a (potentially encrypted) key.

A.12.  11 to 12

   o  Updated to reflect crypto-type's draft using enumerations over
      identities.

Watsen                    Expires May 23, 2020                 [Page 39]
Internet-Draft      A YANG Data Model for a Keystore       November 2019

   o  Added examples for the 'generate-symmetric-key' and 'generate-
      asymmetric-key' RPCs.

   o  Updated the Introduction section.

A.13.  12 to 13

   o  Updated examples to incorporate new "key-format" identities.

   o  Made the two "generate-*-key" RPCs be "action" statements instead.

A.14.  13 to 14

   o  Updated YANG module and examples to incorporate the new
      iana-*-algorithm modules in the crypto-types draft..

A.15.  14 to 15

   o  Added new "Support for Built-in Trust Anchors" section.

   o  Added 'must' expressions asserting that the 'key-format' leaf
      whenever an encrypted key is specified.

Acknowledgements

   The authors would like to thank for following for lively discussions
   on list and in the halls (ordered by first name): Alan Luchuk, Andy
   Bierman, Benoit Claise, Bert Wijnen, Balazs Kovacs, David Lamparter,
   Eric Voit, Ladislav Lhotka, Liang Xia, Juergen Schoenwaelder, Mahesh
   Jethanandani, Martin Bjorklund, Mehmet Ersue, Phil Shafer, Radek
   Krejci, Ramkumar Dhanapal, Reshad Rahman, Sean Turner, and Tom Petch.

Author's Address

   Kent Watsen
   Watsen Networks

   EMail: kent+ietf@watsen.net

Watsen                    Expires May 23, 2020                 [Page 40]