NETCONF Working Group                                          K. Watsen
Internet-Draft                                           Watsen Networks
Intended status: Standards Track                                 H. Wang
Expires: December 19, 22, 2019                                        Huawei
                                                           June 17, 20, 2019

                Common YANG Data Types for Cryptography
                   draft-ietf-netconf-crypto-types-08
                   draft-ietf-netconf-crypto-types-09

Abstract

   This document defines YANG identities, typedefs, the groupings useful
   for cryptographic applications.

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  "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  "2019-06-17"  "2019-06-20" --> the publication date of this draft

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

   o  Appendix B.  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
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   Internet-Drafts are draft documents valid for a maximum of six months
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   material or to cite them other than as "work in progress."

   This Internet-Draft will expire on December 19, 22, 2019.

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.  The Crypto Types Module . . . . . . . . . . . . . . . . . . .   3
     2.1.  Tree Diagram  . . . . . . . . . . . . . . . . . . . . . .   3
     2.2.  YANG Module . . . . . . . . . . . . . . . . . . . . . . .   5
   3.  Security Considerations . . . . . . . . . . . . . . . . . . .  41
     3.1.  Support for Algorithms  . . . . . . . . . . . . . . . . .  41
     3.2.  No Support for CRMF . . . . . . . . . . . . . . . . . . .  42
     3.3.  Access to Data Nodes  . . . . . . . . . . . . . . . . . .  42
   4.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  43
     4.1.  The IETF XML Registry . . . . . . . . . . . . . . . . . .  43
     4.2.  The YANG Module Names Registry  . . . . . . . . . . . . .  43
   5.  References  . . . . . . . . . . . . . . . . . . . . . . . . .  44
     5.1.  Normative References  . . . . . . . . . . . . . . . . . .  44
     5.2.  Informative References  . . . . . . . . . . . . . . . . .  46
   Appendix A.  Examples . . . . . . . . . . . . . . . . . . . . . .  49
     A.1.  The "asymmetric-key-pair-with-certs-grouping" Grouping  .  49
     A.2.  The "generate-certificate-signing-request" Action . . . .  51
     A.3.  The "certificate-expiration" Notification . . . . . . . .  52
   Appendix B.  Change Log . . . . . . . . . . . . . . . . . . . . .  53
     B.1.  I-D to 00 . . . . . . . . . . . . . . . . . . . . . . . .  53
     B.2.  00 to 01  . . . . . . . . . . . . . . . . . . . . . . . .  53
     B.3.  01 to 02  . . . . . . . . . . . . . . . . . . . . . . . .  53
     B.4.  02 to 03  . . . . . . . . . . . . . . . . . . . . . . . .  54
     B.5.  03 to 04  . . . . . . . . . . . . . . . . . . . . . . . .  54
     B.6.  04 to 05  . . . . . . . . . . . . . . . . . . . . . . . .  55
     B.7.  05 to 06  . . . . . . . . . . . . . . . . . . . . . . . .  55
     B.8.  06 to 07  . . . . . . . . . . . . . . . . . . . . . . . .  55
     B.9.  07 to 08  . . . . . . . . . . . . . . . . . . . . . . . .  56
     B.10. 08 to 09  . . . . . . . . . . . . . . . . . . . . . . . .  56
   Acknowledgements  . . . . . . . . . . . . . . . . . . . . . . . .  56
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  56

1.  Introduction

   This document defines a YANG 1.1 [RFC7950] module specifying
   identities, typedefs, and groupings useful for cryptography.

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
   "OPTIONAL" in this document are to be interpreted as described in BCP
   14 [RFC2119] [RFC8174] when, and only when, they appear in all
   capitals, as shown here.

2.  The Crypto Types Module

2.1.  Tree Diagram

   This section provides a tree diagram [RFC8340] for the "ietf-crypto-
   types" module.  Only the groupings as represented, as tree diagrams
   have no means to represent identities or typedefs.

   module: ietf-crypto-types

     grouping symmetric-key-grouping:
       +---- algorithm    identityref    encryption-algorithm-t
       +---- (key-type)
          +--:(key)
          |  +---- key?   binary
          +--:(hidden-key)
             +---- hidden-key?   empty
     grouping public-key-grouping:
       +---- algorithm     asymmetric-key-algorithm-ref     asymmetric-key-algorithm-t
       +---- public-key    binary
     grouping asymmetric-key-pair-grouping:
       +---- algorithm            asymmetric-key-algorithm-ref            asymmetric-key-algorithm-t
       +---- public-key           binary
       +---- (private-key-type)
          +--:(private-key)
          |  +---- private-key?   binary
          +--:(hidden-private-key)
             +---- hidden-private-key?   empty
     grouping trust-anchor-cert-grouping:
       +---- cert?                    trust-anchor-cert-cms
       +---n certificate-expiration
          +--ro expiration-date    ietf-yang-types:date-and-time
     grouping trust-anchor-certs-grouping:
       +---- cert*                    trust-anchor-cert-cms
       +---n certificate-expiration
          +--ro expiration-date    ietf-yang-types:date-and-time
     grouping end-entity-cert-grouping:
       +---- cert?                    end-entity-cert-cms
       +---n certificate-expiration
          +--ro expiration-date    ietf-yang-types:date-and-time
     grouping end-entity-certs-grouping:
       +---- cert*                    end-entity-cert-cms
       +---n certificate-expiration
          +--ro expiration-date    ietf-yang-types:date-and-time
     grouping asymmetric-key-pair-with-cert-grouping:
       +---- algorithm
       |       asymmetric-key-algorithm-ref       asymmetric-key-algorithm-t
       +---- public-key                             binary
       +---- (private-key-type)
       |  +--:(private-key)
       |  |  +---- private-key?   binary
       |  +--:(hidden-private-key)
       |     +---- hidden-private-key?   empty
       +---- cert?                                  end-entity-cert-cms
       +---n certificate-expiration
          +--ro expiration-date    ietf-yang-types:date-and-time
       +---x generate-certificate-signing-request
          +---- input
          |  +---w subject       binary
          |  +---w attributes?   binary
          +---- output
             +--ro certificate-signing-request    binary
     grouping asymmetric-key-pair-with-certs-grouping:
       +---- algorithm
       |       asymmetric-key-algorithm-ref       asymmetric-key-algorithm-t
       +---- public-key                             binary
       +---- (private-key-type)
       |  +--:(private-key)
       |  |  +---- private-key?   binary
       |  +--:(hidden-private-key)
       |     +---- hidden-private-key?   empty
       +---- certificates
       |  +---- certificate* [name]
       |     +---- name                     string
       |     +---- cert?                    end-entity-cert-cms
       |     +---n certificate-expiration
       |        +--ro expiration-date    ietf-yang-types:date-and-time
       +---x generate-certificate-signing-request
          +---- input
          |  +---w subject       binary
          |  +---w attributes?   binary
          +---- output
             +--ro certificate-signing-request    binary

2.2.  YANG Module

   This module has normative references to [RFC2404], [RFC3565],
   [RFC3686], [RFC4106], [RFC4253], [RFC4279], [RFC4309], [RFC4494],
   [RFC4543], [RFC4868], [RFC5280], [RFC5652], [RFC5656], [RFC6187],
   [RFC6991], [RFC7919], [RFC8268], [RFC8332], [RFC8341], [RFC8422],
   [RFC8446], and [ITU.X690.2015].

   This module has an informational reference to [RFC2986], [RFC3174],
   [RFC4493], [RFC5915], [RFC6125], [RFC6234], [RFC6239], [RFC6507],
   [RFC8017], [RFC8032], [RFC8439].

   <CODE BEGINS> file "ietf-crypto-types@2019-06-17.yang" "ietf-crypto-types@2019-06-20.yang"

   module ietf-crypto-types {
     yang-version 1.1;
     namespace "urn:ietf:params:xml:ns:yang:ietf-crypto-types";
     prefix ct;

     import ietf-yang-types {
       prefix yang;
       reference
         "RFC 6991: Common YANG Data Types";
     }

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

     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>
        Author:   Wang Haiguang <wang.haiguang.shieldlab@huawei.com>";

     description
       "This module defines common YANG types for cryptographic
        applications.

        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 2019-06-17 2019-06-20 {
       description
         "Initial version";
       reference
         "RFC XXXX: Common YANG Data Types for Cryptography";
     }

     /**************************************/
     /*   Identities for Hash Algorithms   */
     /**************************************/

    identity hash-algorithm

     typedef hash-algorithm-t {
       type union {
         type uint16;
         type enumeration {
           enum NONE {
             value 0;
             description
        "A base identity for hash
               "Hash algorithm verification."; is NULL.";
           }

    identity
           enum sha1 {
             value 1;
             status obsolete;
             description
               "The SHA1 algorithm.";
             reference
               "RFC 3174: US Secure Hash Algorithms 1 (SHA1).";

           }
           enum sha-224 {
      base hash-algorithm;
             value 2;
             description
               "The SHA-224 algorithm.";
             reference
               "RFC 6234: US Secure Hash Algorithms.";
           }

    identity
           enum sha-256 {
      base hash-algorithm;
             value 3;
             description
               "The SHA-256 algorithm.";
             reference
               "RFC 6234: US Secure Hash Algorithms.";
           }

    identity
           enum sha-384 {
      base hash-algorithm;
             value 4;
             description
               "The SHA-384 algorithm.";
             reference
               "RFC 6234: US Secure Hash Algorithms.";
           }

    identity
           enum sha-512 {
      base hash-algorithm;
             value 5;
             description
               "The SHA-512 algorithm.";
             reference
               "RFC 6234: US Secure Hash Algorithms.";
           }
         }
       }
       default "0";
       description
         "The uint16 filed shall be set by individual protocol families
          according to the hash algorithm value assigned by IANA. The
          setting is optional and by default is 0.  The enumeration
          filed is set to the selected hash algorithm.";
     }

     /***********************************************/
     /*  Identities for Asymmetric Key Algorithms   */
     /***********************************************/

    identity asymmetric-key-algorithm

     typedef asymmetric-key-algorithm-t {
       type union {
         type uint16;
         type enumeration {
           enum NONE {
             value 0;
             description
        "Base identity from which all asymmetric
               "Asymetric key
         encryption Algorithm."; algorithm is NULL.";
           }

    identity
           enum rsa1024 {
      base asymmetric-key-algorithm;
             value 1;
             description
               "The RSA algorithm using a 1024-bit key.";
             reference
               "RFC 8017: PKCS #1: RSA Cryptography
                Specifications Version 2.2.";
           }

    identity
           enum rsa2048 {
      base asymmetric-key-algorithm;
             value 2;
             description
               "The RSA algorithm using a 2048-bit key.";
             reference
               "RFC 8017:
                PKCS #1: RSA Cryptography Specifications Version 2.2.";
           }

    identity
           enum rsa3072 {
      base asymmetric-key-algorithm;
             value 3;
             description
               "The RSA algorithm using a 3072-bit key.";
             reference
               "RFC 8017:
                PKCS #1: RSA Cryptography Specifications Version 2.2.";
           }

    identity
           enum rsa4096 {
      base asymmetric-key-algorithm;
             value 4;
             description
               "The RSA algorithm using a 4096-bit key.";
             reference
               "RFC 8017:
                PKCS #1: RSA Cryptography Specifications Version 2.2.";
           }

    identity
           enum rsa7680 {
      base asymmetric-key-algorithm;
             value 5;
             description
               "The RSA algorithm using a 7680-bit key.";
             reference
               "RFC 8017:
                PKCS #1: RSA Cryptography Specifications Version 2.2.";
           }

    identity
           enum rsa15360 {
      base asymmetric-key-algorithm;
             value 6;
             description
               "The RSA algorithm using a 15360-bit key.";

             reference
               "RFC 8017:
                PKCS #1: RSA Cryptography Specifications Version 2.2.";
           }

    identity
           enum secp192r1 {
      base asymmetric-key-algorithm;
             value 7;
             description
               "The ECDSA algorithm using a NIST P192 Curve.";
             reference
               "RFC 6090:
                  Fundamental Elliptic Curve Cryptography Algorithms.
                RFC 5480:
                   Elliptic Curve Cryptography Subject Public Key
                   Information.";
           }
    identity
           enum secp224r1 {
      base asymmetric-key-algorithm;
             value 8;
             description
               "The ECDSA algorithm using a NIST P224 Curve.";
             reference
               "RFC 6090:
                  Fundamental Elliptic Curve Cryptography Algorithms.
                RFC 5480:
                  Elliptic Curve Cryptography Subject Public Key
                  Information.";
           }

    identity
           enum secp256r1 {
      base asymmetric-key-algorithm;
             value 9;
             description
               "The ECDSA algorithm using a NIST P256 Curve.";
             reference
               "RFC 6090:
                  Fundamental Elliptic Curve Cryptography Algorithms.
                RFC 5480:
                  Elliptic Curve Cryptography Subject Public Key
                  Information.";
           }

    identity
           enum secp384r1 {
      base asymmetric-key-algorithm;
             value 10;
             description
               "The ECDSA algorithm using a NIST P384 Curve.";
             reference
               "RFC 6090:
                  Fundamental Elliptic Curve Cryptography Algorithms.
                RFC 5480:
                  Elliptic Curve Cryptography Subject Public Key
                  Information.";
           }

    identity
           enum secp521r1 {
      base asymmetric-key-algorithm;
             value 11;
             description
               "The ECDSA algorithm using a NIST P521 Curve.";
             reference
               "RFC 6090:
                  Fundamental Elliptic Curve Cryptography Algorithms.
                RFC 5480:
                  Elliptic Curve Cryptography Subject Public Key
                  Information.";
           }
         }
       }
       default "0";
       description
         "The uint16 filed shall be set by individual protocol
          families according to the asymmetric key algorithm value
          assigned by IANA. The setting is optional and by default
          is 0.  The enumeration filed is set to the selected
          asymmetric key algorithm.";
     }

     /*************************************/
     /*   Identities for MAC Algorithms   */
     /*************************************/
    identity mac-algorithm

     typedef mac-algorithm-t {
       type union {
         type uint16;
         type enumeration {
           enum NONE {
             value 0;
             description
        "A base identity for mac generation.";
               "mac algorithm is NULL.";
           }

    identity
           enum hmac-sha1 {
      base mac-algorithm;
             value 1;
             description
               "Generating MAC using SHA1 hash function";
             reference
               "RFC 3174: US Secure Hash Algorithm 1 (SHA1)";
           }

    identity
           enum hmac-sha1-96 {
      base mac-algorithm;
             value 2;
             description
               "Generating MAC using SHA1 hash function";
             reference
               "RFC 2404: The Use of HMAC-SHA-1-96 within ESP and AH";

           }

    identity
           enum hmac-sha2-224 {
      base mac-algorithm;
             value 3;
             description
               "Generating MAC using SHA2 hash function";
             reference
               "RFC 6234: US Secure Hash Algorithms
                (SHA and SHA-based HMAC and HKDF)";
           }

    identity
           enum hmac-sha2-256 {
      base mac-algorithm;
             value 4;
             description
               "Generating MAC using SHA2 hash function";
             reference
               "RFC 6234: US Secure Hash Algorithms
                (SHA and SHA-based HMAC and HKDF)";
           }

    identity
           enum hmac-sha2-256-128 {
      base mac-algorithm;
             value 5;
             description
               "Generating a 256 bits MAC using SHA2 hash function and
                truncate it to 128 bits";
             reference
               "RFC 4868: Using HMAC-SHA-256, HMAC-SHA-384,
                and HMAC-SHA-512 with IPsec";
           }

    identity
           enum hmac-sha2-384 {
      base mac-algorithm;
             value 6;
             description
               "Generating a 384 bits MAC using SHA2 hash function";
             reference
               "RFC 6234: US Secure Hash Algorithms
                (SHA and SHA-based HMAC and HKDF)";
           }

    identity
           enum hmac-sha2-384-192 {
      base mac-algorithm;
             value 7;
             description
               "Generating a 384 bits MAC using SHA2 hash function and
                truncate it to 192 bits";
             reference
               "RFC 4868: Using HMAC-SHA-256, HMAC-SHA-384,
                and HMAC-SHA-512 with IPsec";
           }

    identity
           enum hmac-sha2-512 {
      base mac-algorithm;
             value 8;
             description
               "Generating a 512 bits MAC using SHA2 hash function";
             reference
               "RFC 6234: US Secure Hash Algorithms
                (SHA and SHA-based HMAC and HKDF)";
           }

    identity
           enum hmac-sha2-512-256 {
      base mac-algorithm;
             value 9;
             description
               "Generating a 512 bits MAC using SHA2 hash function and
         truncating
                truncate it to 256 bits";
             reference
               "RFC 4868: Using HMAC-SHA-256, HMAC-SHA-384,
                and HMAC-SHA-512 with IPsec";
           }

    identity
           enum aes-128-gmac {
      base mac-algorithm;
             value 10;
             description
               "Generating 128-bit MAC using the Advanced Encryption
                Standard (AES) Galois Message Authentication Code
                (GMAC) as a mechanism to provide data origin authentication";
                authentication.";
             reference
               "RFC 4543:
                  The Use of Galois Message Authentication Code (GMAC)
                  in IPsec ESP and AH";
           }

    identity
           enum aes-192-gmac {
      base mac-algorithm;
             value 11;
             description
               "Generating 192-bit MAC using the Advanced Encryption
                Standard (AES) Galois Message Authentication Code
                (GMAC) as a mechanism to provide data origin authentication";
                authentication.";
             reference
               "RFC 4543:
                  The Use of Galois Message Authentication Code (GMAC)
                  in IPsec ESP and AH";
           }

    identity
           enum aes-256-gmac {
      base mac-algorithm;
             value 12;
             description
               "Generating 256-bit MAC using the Advanced Encryption
                Standard (AES) Galois Message Authentication Code
                (GMAC) as a mechanism to provide data origin authentication";
                authentication.";
             reference
               "RFC 4543:
                  The Use of Galois Message Authentication Code (GMAC)
                  in IPsec ESP and AH";
           }

    identity
           enum aes-cmac-96 {
      base mac-algorithm;
             value 13;
             description
               "Generating 96-bit MAC using Advanced Encryption
                Standard (AES) Cipher-based Message Authentication
                Code (CMAC)";
             reference
               "RFC 4494:
                  The AES-CMAC-96 AES-CMAC Algorithm and its Use with IPsec";
           }

    identity
           enum aes-cmac-128 {
      base mac-algorithm;
             value 14;
             description
               "Generating 128-bit MAC using Advanced Encryption
                Standard (AES) Cipher-based Message Authentication
                Code (CMAC)";
             reference
               "RFC 4493: 4494:
                  The AES-CMAC Algorithm"; Algorithm and its Use with IPsec";
           }
         }
       }
       default "0";
       description
         "The uint16 filed shall be set by individual protocol
          families according to the mac algorithm value assigned by
          IANA. The setting is optional and by default is 0.  The
          enumeration filed is set to the selected mac algorithm.";
     }

     /********************************************/
     /*   Identities for Encryption Algorithms   */
     /********************************************/

    identity encryption-algorithm

     typedef encryption-algorithm-t {
       type union {
         type uint16;
         type enumeration {
           enum NONE {
             value 0;
             description
        "A base identity for encryption algorithm.";
               "Encryption algorithm is NULL.";
           }

    identity
           enum aes-128-cbc {
      base encryption-algorithm;
             value 1;
             description
               "Encrypt message with AES algorithm in CBC mode with
                a key length of 128 bits"; bits.";

             reference
               "RFC 3565: Use of the Advanced Encryption Standard (AES)
                Encryption Algorithm in Cryptographic Message Syntax
                (CMS)";
           }

    identity
           enum aes-192-cbc {
      base encryption-algorithm;
             value 2;
             description
               "Encrypt message with AES algorithm in CBC mode with
                a key length of 192 bits";
             reference
               "RFC 3565: Use of the Advanced Encryption Standard (AES)
                Encryption Algorithm in Cryptographic Message Syntax
                (CMS)";
           }

    identity
           enum aes-256-cbc {
      base encryption-algorithm;
             value 3;
             description
               "Encrypt message with AES algorithm in CBC mode with
                a key length of 256 bits";
             reference
               "RFC 3565: Use of the Advanced Encryption Standard (AES)
                Encryption Algorithm in Cryptographic Message Syntax
                (CMS)";
           }

    identity
           enum aes-128-ctr {
      base encryption-algorithm;
             value 4;
             description
               "Encrypt message with AES algorithm in CTR mode with
                a key length of 128 bits";
             reference
               "RFC 3686:
                  Using Advanced Encryption Standard (AES) Counter
                  Mode with IPsec Encapsulating Security Payload
                  (ESP)";
           }

    identity
           enum aes-192-ctr {
      base encryption-algorithm;
             value 5;
             description
               "Encrypt message with AES algorithm in CTR mode with
                a key length of 192 bits";
             reference
               "RFC 3686:
                  Using Advanced Encryption Standard (AES) Counter
                  Mode with IPsec Encapsulating Security Payload
                  (ESP)";
           }

    identity
           enum aes-256-ctr {
      base encryption-algorithm;
             value 6;
             description
               "Encrypt message with AES algorithm in CTR mode with
                a key length of 256 bits";
             reference
               "RFC 3686:
                  Using Advanced Encryption Standard (AES) Counter
                  Mode with IPsec Encapsulating Security Payload
                  (ESP)";
           }
         }
       }
       default "0";
       description
         "The uint16 filed shall be set by individual protocol
          families according to the encryption algorithm value
          assigned by IANA. The setting is optional and by default
          is 0.  The enumeration filed is set to the selected
          encryption algorithm.";
     }

     /****************************************************/
     /*   Identities for Encryption and MAC Algorithms   */
     /****************************************************/

    identity encryption-and-mac-algorithm

     typedef encryption-and-mac-algorithm-t {
       type union {
         type uint16;
         type enumeration {
           enum NONE {
             value 0;
             description
        "A base identity for encryption
               "Encryption and MAC algorithm."; algorithm is NULL.";
             reference
               "None";
           }

    identity
           enum aes-128-ccm {
      base encryption-and-mac-algorithm;
             value 1;
             description
               "Encrypt message with AES algorithm in CCM
                mode with a key length of 128 bits; it can
                also be used for generating MAC";
             reference
               "RFC 4309: Using Advanced Encryption Standard
                (AES) CCM Mode with IPsec Encapsulating Security
                Payload (ESP)";
           }

    identity
           enum aes-192-ccm {
      base encryption-and-mac-algorithm;
             value 2;
             description
               "Encrypt message with AES algorithm in CCM
                mode with a key length of 192 bits; it can
                also be used for generating MAC";
             reference
               "RFC 4309: Using Advanced Encryption Standard
                (AES) CCM Mode with IPsec Encapsulating Security
                Payload (ESP)";
           }

    identity
           enum aes-256-ccm {
      base encryption-and-mac-algorithm;
             value 3;
             description
               "Encrypt message with AES algorithm in CCM
                mode with a key length of 256 bits; it can
                also be used for generating MAC";
             reference
               "RFC 4309: Using Advanced Encryption Standard
                (AES) CCM Mode with IPsec Encapsulating Security
                Payload (ESP)";
           }

    identity
           enum aes-128-gcm {
      base encryption-and-mac-algorithm;
             value 4;
             description
               "Encrypt message with AES algorithm in GCM
                mode with a key length of 128 bits; it can
                also be used for generating MAC";
             reference
               "RFC 4106: The Use of Galois/Counter Mode (GCM)
                in IPsec Encapsulating Security Payload (ESP)";
           }

    identity
           enum aes-192-gcm {
      base encryption-and-mac-algorithm;
             value 5;
             description
               "Encrypt message with AES algorithm in GCM
                mode with a key length of 192 bits; it can
                also be used for generating MAC";
             reference
               "RFC 4106: The Use of Galois/Counter Mode (GCM)
                in IPsec Encapsulating Security Payload (ESP)";
           }

    identity mac-aes-256-gcm
           enum aes-256-gcm {
      base encryption-and-mac-algorithm;
             value 6;
             description
               "Encrypt message with AES algorithm in GCM
                mode with a key length of 128 256 bits; it can
                also be used for generating MAC";
             reference
               "RFC 4106: The Use of Galois/Counter Mode (GCM)
                in IPsec Encapsulating Security Payload (ESP)";
           }

    identity
           enum chacha20-poly1305 {
      base encryption-and-mac-algorithm;
             value 7;
             description
               "Encrypt message with chacha20 algorithm and generate
                MAC with POLY1305; it can also be used for generating
                MAC";
             reference
               "RFC 8439: ChaCha20 and Poly1305 for IETF Protocols";
           }
         }
       }
       default "0";
       description
         "The uint16 filed shall be set by individual protocol
          families according to the encryption and mac algorithm value
          assigned by IANA. The setting is optional and by default is
          0.  The enumeration filed is set to the selected encryption
          and mac algorithm.";
     }

     /******************************************/
     /*   Identities for signature algorithm   */
     /******************************************/

    identity signature-algorithm

     typedef signature-algorithm-t {
       type union {
         type uint16;
         type enumeration {
           enum NONE {
             value 0;
             description
        "A base identity for asymmetric key encryption algorithm.";
               "Signature algorithm is NULL";
           }

    identity
           enum dsa-sha1 {
      base signature-algorithm;
             value 1;
             description
               "The signature algorithm using DSA algorithm with SHA1
                hash algorithm";
             reference
               "RFC 4253:
                  The Secure Shell (SSH) Transport Layer Protocol";
           }

    identity
           enum rsassa-pkcs1-sha1 {
      base signature-algorithm;
             value 2;
             description
               "The signature algorithm using RSASSA-PKCS1-v1_5 with
                the SHA1 hash algorithm.";
             reference
               "RFC 4253:
                  The Secure Shell (SSH) Transport Layer Protocol";
           }

    identity
           enum rsassa-pkcs1-sha256 {
      base signature-algorithm;
             value 3;
             description
               "The signature algorithm using RSASSA-PKCS1-v1_5 with
                the SHA256 hash algorithm.";
             reference
               "RFC 8332:
                  Use of RSA Keys with SHA-256 and SHA-512 in the
                  Secure Shell (SSH) Protocol
                RFC 8446:
                  The Transport Layer Security (TLS) Protocol
                  Version 1.3";
           }

    identity
           enum rsassa-pkcs1-sha384 {
      base signature-algorithm;
             value 4;
             description
               "The signature algorithm using RSASSA-PKCS1-v1_5 with
                the SHA384 hash algorithm.";
             reference
               "RFC 8446:
                  The Transport Layer Security (TLS) Protocol
                  Version 1.3";
           }

    identity
           enum rsassa-pkcs1-sha512 {
      base signature-algorithm;
             value 5;
             description
               "The signature algorithm using RSASSA-PKCS1-v1_5 with
                the SHA512 hash algorithm.";
             reference
               "RFC 8332:
                  Use of RSA Keys with SHA-256 and SHA-512 in the
                  Secure Shell (SSH) Protocol
                RFC 8446:
                  The Transport Layer Security (TLS) Protocol
                  Version 1.3";
           }

    identity
           enum rsassa-pss-rsae-sha256 {
      base signature-algorithm;
             value 6;
             description
               "The signature algorithm using RSASSA-PSS with mask
                generation function 1 and SHA256 hash algorithm. If
                the public key is carried in an X.509 certificate,
                it MUST use the rsaEncryption OID";
             reference
               "RFC 8446:
                  The Transport Layer Security (TLS) Protocol
                  Version 1.3";
           }

    identity
           enum rsassa-pss-rsae-sha384 {
      base signature-algorithm;
             value 7;
             description
               "The signature algorithm using RSASSA-PSS with mask
                generation function 1 and SHA384 hash algorithm. If
                the public key is carried in an X.509 certificate,
                it MUST use the rsaEncryption OID";
             reference
               "RFC 8446:
                  The Transport Layer Security (TLS) Protocol
                  Version 1.3";
           }

    identity
           enum rsassa-pss-rsae-sha512 {
      base signature-algorithm;
             value 8;
             description
               "The signature algorithm using RSASSA-PSS with mask
                generation function 1 and SHA512 hash algorithm. If
                the public key is carried in an X.509 certificate,
                it MUST use the rsaEncryption OID";
             reference
               "RFC 8446:
                  The Transport Layer Security (TLS) Protocol
                  Version 1.3";
           }

    identity
           enum rsassa-pss-pss-sha256 {
      base signature-algorithm;
             value 9;
             description
               "The signature algorithm using RSASSA-PSS with mask
                generation function 1 and SHA256 hash algorithm. If
                the public key is carried in an X.509 certificate,
                it MUST use the RSASSA-PSS rsaEncryption OID";
             reference
               "RFC 8446:
                  The Transport Layer Security (TLS) Protocol
                  Version 1.3";
           }

    identity
           enum rsassa-pss-pss-sha384 {
      base signature-algorithm;
             value 10;
             description
               "The signature algorithm using RSASSA-PSS with mask
                generation function 1 and SHA256 SHA384 hash algorithm. If
                the public key is carried in an X.509 certificate,
                it MUST use the RSASSA-PSS rsaEncryption OID";
             reference
               "RFC 8446:
                  The Transport Layer Security (TLS) Protocol
                  Version 1.3";
           }

    identity
           enum rsassa-pss-pss-sha512 {
      base signature-algorithm;
             value 11;
             description
               "The signature algorithm using RSASSA-PSS with mask
                generation function 1 and SHA256 SHA512 hash algorithm. If
                the public key is carried in an X.509 certificate,
                it MUST use the RSASSA-PSS rsaEncryption OID";
             reference
               "RFC 8446:
                  The Transport Layer Security (TLS) Protocol
                  Version 1.3";
           }

    identity
           enum ecdsa-secp256r1-sha256 {
      base signature-algorithm;
             value 12;
             description
               "The signature algorithm using ECDSA with curve name
                secp256r1 and SHA256 hash algorithm.";
             reference
               "RFC 5656:
                  Elliptic Curve Algorithm Integration in the Secure
                  Shell Transport Layer
                RFC 8446:
                  The Transport Layer Security (TLS) Protocol
                  Version 1.3";
           }

    identity
           enum ecdsa-secp384r1-sha384 {
      base signature-algorithm;
             value 13;
             description
               "The signature algorithm using ECDSA with curve name
                secp384r1 and SHA384 hash algorithm.";
             reference
               "RFC 5656:
                  Elliptic Curve Algorithm Integration in the Secure
                  Shell Transport Layer
                RFC 8446:
                  The Transport Layer Security (TLS) Protocol
                  Version 1.3";
           }

    identity
           enum ecdsa-secp521r1-sha512 {
      base signature-algorithm;
             value 14;
             description
               "The signature algorithm using ECDSA with curve name
                secp521r1 and SHA512 hash algorithm.";
             reference
               "RFC 5656:
                  Elliptic Curve Algorithm Integration in the Secure
                  Shell Transport Layer
                RFC 8446:
                  The Transport Layer Security (TLS) Protocol
                  Version 1.3";
           }

    identity
           enum ed25519 {
      base signature-algorithm;
             value 15;
             description
               "The signature algorithm using EdDSA as defined in
                RFC 8032 or its successors.";
             reference
               "RFC 8032:
                  Edwards-Curve Digital Signature Algorithm (EdDSA)";
           }

    identity
           enum ed448 {
      base signature-algorithm;
             value 16;
             description
               "The signature algorithm using EdDSA as defined in
                RFC 8032 or its successors.";
             reference
               "RFC 8032:
                  Edwards-Curve Digital Signature Algorithm (EdDSA)";
           }

    identity
           enum eccsi {
      base signature-algorithm;
             value 17;
             description
               "The signature algorithm using ECCSI signature as
                defined in RFC 6507.";
             reference
               "RFC 6507:
                  Elliptic Curve-Based Certificateless Signatures
                  for Identity-based Encryption (ECCSI)";
           }
         }
       }
       default "0";
       description
         "The uint16 filed shall be set by individual protocol
          families according to the signature algorithm value
          assigned by IANA. The setting is optional and by default
          is 0.  The enumeration filed is set to the selected
          signature algorithm.";
     }
     /**********************************************/
     /*   Identities for key exchange algorithms   */
     /**********************************************/

    identity key-exchange-algorithm

     typedef key-exchange-algorithm-t {
       type union {
         type uint16;
         type enumeration {
           enum NONE {
             value 0;
             description
        "A base identity for Diffie-Hellman based key
               "Key exchange
         algorithm."; algorithm is NULL.";
           }

    identity
           enum psk-only {
      base key-exchange-algorithm;
             value 1;
             description
               "Using Pre-shared key for authentication and key
                exchange";
             reference
               "RFC 4279:
                  Pre-Shared Key cipher suites for Transport Layer
                  Security (TLS)";
           }

    identity
           enum dhe-ffdhe2048 {
      base key-exchange-algorithm;
             value 2;
             description
               "Ephemeral Diffie Hellman key exchange with 2048 bit
                finite field";
             reference
               "RFC 7919:
                  Negotiated Finite Field Diffie-Hellman Ephemeral
                  Parameters for Transport Layer Security (TLS)";
           }

    identity
           enum dhe-ffdhe3072 {
      base key-exchange-algorithm;
             value 3;
             description
               "Ephemeral Diffie Hellman key exchange with 3072 bit
                finite field";
             reference
               "RFC 7919:
                  Negotiated Finite Field Diffie-Hellman Ephemeral
                  Parameters for Transport Layer Security (TLS)";
           }

    identity
           enum dhe-ffdhe4096 {
      base key-exchange-algorithm;
             value 4;
             description
               "Ephemeral Diffie Hellman key exchange with 4096 bit
                finite field";

             reference
               "RFC 7919:
                  Negotiated Finite Field Diffie-Hellman Ephemeral
                  Parameters for Transport Layer Security (TLS)";
           }

    identity
           enum dhe-ffdhe6144 {
      base key-exchange-algorithm;
             value 5;
             description
               "Ephemeral Diffie Hellman key exchange with 6144 bit
                finite field";
             reference
               "RFC 7919:
                  Negotiated Finite Field Diffie-Hellman Ephemeral
                  Parameters for Transport Layer Security (TLS)";
           }

    identity
           enum dhe-ffdhe8192 {
      base key-exchange-algorithm;
             value 6;
             description
               "Ephemeral Diffie Hellman key exchange with 8192 bit
                finite field";
             reference
               "RFC 7919:
                  Negotiated Finite Field Diffie-Hellman Ephemeral
                  Parameters for Transport Layer Security (TLS)";
           }

    identity
           enum psk-dhe-ffdhe2048 {
      base key-exchange-algorithm;
             value 7;
             description
               "Key exchange using pre-shared key with Diffie-Hellman
                key generation mechanism, where the DH group is
                FFDHE2048";
             reference
               "RFC 8446:
                  The Transport Layer Security (TLS) Protocol
                  Version 1.3";
           }

    identity
           enum psk-dhe-ffdhe3072 {
      base key-exchange-algorithm;
             value 8;
             description
               "Key exchange using pre-shared key with Diffie-Hellman
                key generation mechanism, where the DH group is
                FFDHE3072";
             reference
               "RFC 8446:
                  The Transport Layer Security (TLS) Protocol
                  Version 1.3";
           }

    identity
           enum psk-dhe-ffdhe4096 {
      base key-exchange-algorithm;
             value 9;
             description
               "Key exchange using pre-shared key with Diffie-Hellman
                key generation mechanism, where the DH group is
                FFDHE4096";
             reference
               "RFC 8446:
                  The Transport Layer Security (TLS) Protocol
                  Version 1.3";
           }

    identity
           enum psk-dhe-ffdhe6144 {
      base key-exchange-algorithm;
             value 10;
             description
               "Key exchange using pre-shared key with Diffie-Hellman
                key generation mechanism, where the DH group is
                FFDHE6144";
             reference
               "RFC 8446:
                  The Transport Layer Security (TLS) Protocol
                  Version 1.3";
           }

    identity
           enum psk-dhe-ffdhe8192 {
      base key-exchange-algorithm;
             value 11;
             description
               "Key exchange using pre-shared key with Diffie-Hellman
                key generation mechanism, where the DH group is
                FFDHE8192";
             reference
               "RFC 8446:
                  The Transport Layer Security (TLS) Protocol
                  Version 1.3";
           }

    identity
           enum ecdhe-secp256r1 {
      base key-exchange-algorithm;
             value 12;
             description
               "Ephemeral Diffie Hellman key exchange with elliptic
                group over curve secp256r1";
             reference
               "RFC 8422:
                  Elliptic Curve Cryptography (ECC) Cipher Suites
                  for Transport Layer Security (TLS) Versions 1.2
                  and Earlier";
           }

    identity
           enum ecdhe-secp384r1 {
      base key-exchange-algorithm;
             value 13;
             description
               "Ephemeral Diffie Hellman key exchange with elliptic
                group over curve secp384r1";

             reference
               "RFC 8422:
                  Elliptic Curve Cryptography (ECC) Cipher Suites
                  for Transport Layer Security (TLS) Versions 1.2
                  and Earlier";
           }

    identity
           enum ecdhe-secp521r1 {
      base key-exchange-algorithm;
             value 14;
             description
               "Ephemeral Diffie Hellman key exchange with elliptic
                group over curve secp521r1";
             reference
               "RFC 8422:
                  Elliptic Curve Cryptography (ECC) Cipher Suites
                  for Transport Layer Security (TLS) Versions 1.2
                  and Earlier";
           }

    identity
           enum ecdhe-x25519 {
      base key-exchange-algorithm;
             value 15;
             description
               "Ephemeral Diffie Hellman key exchange with elliptic
                group over curve x25519";
             reference
               "RFC 8422:
                  Elliptic Curve Cryptography (ECC) Cipher Suites
                  for Transport Layer Security (TLS) Versions 1.2
                  and Earlier";
           }

    identity
           enum ecdhe-x448 {
      base key-exchange-algorithm;
             value 16;
             description
               "Ephemeral Diffie Hellman key exchange with elliptic
                group over curve x448";
             reference
               "RFC 8422:
                  Elliptic Curve Cryptography (ECC) Cipher Suites
                  for Transport Layer Security (TLS) Versions 1.2
                  and Earlier";
           }

    identity
           enum psk-ecdhe-secp256r1 {
      base key-exchange-algorithm;
             value 17;
             description
               "Key exchange using pre-shared key with elliptic
                group-based Ephemeral Diffie Hellman key exchange
                over curve secp256r1";
             reference
               "RFC 8446:
                  The Transport Layer Security (TLS) Protocol
                  Version 1.3";
           }

    identity
           enum psk-ecdhe-secp384r1 {
      base key-exchange-algorithm;
             value 18;
             description
               "Key exchange using pre-shared key with elliptic
                group-based Ephemeral Diffie Hellman key exchange
                over curve secp384r1";
             reference
               "RFC 8446:
                  The Transport Layer Security (TLS) Protocol
                  Version 1.3";
           }

    identity
           enum psk-ecdhe-secp521r1 {
      base key-exchange-algorithm;
             value 19;
             description
               "Key exchange using pre-shared key with elliptic
                group-based Ephemeral Diffie Hellman key exchange
                over curve secp521r1";
             reference
               "RFC 8446:
                  The Transport Layer Security (TLS) Protocol
                  Version 1.3";
           }

    identity
           enum psk-ecdhe-x25519 {
      base key-exchange-algorithm;
             value 20;
             description
               "Key exchange using pre-shared key with elliptic
                group-based Ephemeral Diffie Hellman key exchange
                over curve x25519";
             reference
               "RFC 8446:
                  The Transport Layer Security (TLS) Protocol
                  Version 1.3";
           }

    identity
           enum psk-ecdhe-x448 {
      base key-exchange-algorithm;
             value 21;
             description
               "Key exchange using pre-shared key with elliptic
                group-based Ephemeral Diffie Hellman key exchange
                over curve x448";
             reference
               "RFC 8446:
                  The Transport Layer Security (TLS) Protocol
                  Version 1.3";
           }

    identity
           enum diffie-hellman-group14-sha1 {
      base key-exchange-algorithm;
             value 22;
             description
               "Using DH group14 and SHA1 for key exchange";
             reference
               "RFC 4253:
                  The Secure Shell (SSH) Transport Layer Protocol";
           }

    identity
           enum diffie-hellman-group14-sha256 {
      base key-exchange-algorithm;
             value 23;
             description
               "Using DH group14 and SHA256 SHA-256 for key exchange";
             reference
               "RFC 8268:
                 More Modular Exponentiation (MODP) Diffie-Hellman (DH)
                 Key Exchange (KEX) Groups for Secure Shell (SSH)";
           }

    identity
           enum diffie-hellman-group15-sha512 {
      base key-exchange-algorithm;
             value 24;
             description
               "Using DH group15 and SHA512 SHA-512 for key exchange";
             reference
               "RFC 8268:
                 More Modular Exponentiation (MODP) Diffie-Hellman (DH)
                 Key Exchange (KEX) Groups for Secure Shell (SSH)";
           }

    identity
           enum diffie-hellman-group16-sha512 {
      base key-exchange-algorithm;
             value 25;
             description
               "Using DH group16 and SHA512 SHA-512 for key exchange";
             reference
               "RFC 8268:
                 More Modular Exponentiation (MODP) Diffie-Hellman (DH)
                 Key Exchange (KEX) Groups for Secure Shell (SSH)";
           }

    identity
           enum diffie-hellman-group17-sha512 {
      base key-exchange-algorithm;
             value 26;
             description
               "Using DH group17 and SHA512 SHA-512 for key exchange";
             reference
               "RFC 8268:
                 More Modular Exponentiation (MODP) Diffie-Hellman (DH)
                 Key Exchange (KEX) Groups for Secure Shell (SSH)";
           }

    identity
           enum diffie-hellman-group18-sha512 {
      base key-exchange-algorithm;
             value 27;
             description
               "Using DH group18 and SHA512 SHA-512 for key exchange";
             reference
               "RFC 8268:

                 More Modular Exponentiation (MODP) Diffie-Hellman (DH)
                 Key Exchange (KEX) Groups for Secure Shell (SSH)";
           }

    identity
           enum ecdh-sha2-secp256r1 {
      base key-exchange-algorithm;
             value 28;
             description
               "Elliptic curve-based Diffie Hellman key exchange over
                curve
         secp256r1 ecp256r1 and using SHA2 for MAC generation";
             reference
               "RFC 6239:
                  Suite B Cryptographic Suites for Secure Shell (SSH)";
           }

    identity
           enum ecdh-sha2-secp384r1 {
      base key-exchange-algorithm;
             value 29;
             description
               "Elliptic curve-based Diffie Hellman key exchange over
                curve
         secp384r1 ecp384r1 and using SHA2 for MAC generation";
             reference
               "RFC 6239:
                  Suite B Cryptographic Suites for Secure Shell (SSH)";
           }

    identity
           enum rsaes-oaep {
      base key-exchange-algorithm;
             value 30;
             description
               "RSAES-OAEP combines the RSAEP and RSADP primitives with
                the EME-OAEP encoding method";
             reference
               "RFC 8017:
                  PKCS #1:
                    RSA Cryptography Specifications Version 2.2.";
           }

    identity
           enum rsaes-pkcs1-v1_5 {
      base key-exchange-algorithm;
             value 31;
             description
        " RSAES-PKCS1-v1_5
               "RSAES-PKCS1-v1_5 combines the RSAEP and RSADP
                primitives with the EME-PKCS1-v1_5 encoding method";
             reference
               "RFC 8017:
                  PKCS #1:
                    RSA Cryptography Specifications Version 2.2.";
           }

    /**********************************************************/
    /*   Typedefs for identityrefs to above base identities   */
    /**********************************************************/

    typedef hash-algorithm-ref {
      type identityref {
        base hash-algorithm;
      }
      description
        "This typedef enables importing modules to easily define an
         identityref to the 'hash-algorithm' base identity.";
    }

    typedef signature-algorithm-ref {
      type identityref {
        base signature-algorithm;
      }
      description
        "This typedef enables importing modules to easily define an
         identityref to the 'signature-algorithm' base identity.";
    }

    typedef mac-algorithm-ref {
      type identityref {
        base mac-algorithm;
      }
      description
        "This typedef enables importing modules to easily define an
         identityref to the 'mac-algorithm' base identity.";

    }

    typedef encryption-algorithm-ref {
      type identityref {
        base encryption-algorithm;
      }
      description
        "This typedef enables importing modules to easily define an
         identityref to the 'encryption-algorithm'
         base identity.";
    }

    typedef encryption-and-mac-algorithm-ref {
      type identityref {
        base encryption-and-mac-algorithm;
      }
      description
        "This typedef enables importing modules to easily define an
         identityref to the 'encryption-and-mac-algorithm'
         base identity.";
         }

    typedef asymmetric-key-algorithm-ref {
      type identityref {
        base asymmetric-key-algorithm;
       }
       default "0";
       description
        "This typedef enables importing modules to easily define an
         identityref
         "The uint16 filed shall be set by individual protocol
          families according to the 'asymmetric-key-algorithm'
         base identity.";
    }

    typedef key-exchange-algorithm-ref {
      type identityref {
        base key-exchange-algorithm;
      }
      description
        "This typedef enables importing modules to easily define an
         identityref key exchange algorithm value
          assigned by IANA. The setting is optional and by default
          is 0.  The enumeration filed is set to the 'key-exchange-algorithm' base identity."; selected key
          exchange algorithm.";
     }

     /***************************************************/
     /*   Typedefs for ASN.1 structures from RFC 5280   */
     /***************************************************/

     typedef x509 {
       type binary;
       description
         "A Certificate structure, as specified in RFC 5280,
          encoded using ASN.1 distinguished encoding rules (DER),
          as specified in ITU-T X.690.";
       reference
         "RFC 5280:
            Internet X.509 Public Key Infrastructure Certificate
            and Certificate Revocation List (CRL) Profile
          ITU-T X.690:
            Information technology - ASN.1 encoding rules:
            Specification of Basic Encoding Rules (BER),
            Canonical Encoding Rules (CER) and Distinguished
            Encoding Rules (DER).";
     }

     typedef crl {
       type binary;
       description
         "A CertificateList structure, as specified in RFC 5280,
          encoded using ASN.1 distinguished encoding rules (DER),
          as specified in ITU-T X.690.";
       reference
         "RFC 5280:
            Internet X.509 Public Key Infrastructure Certificate
            and Certificate Revocation List (CRL) Profile
          ITU-T X.690:
            Information technology - ASN.1 encoding rules:
            Specification of Basic Encoding Rules (BER),
            Canonical Encoding Rules (CER) and Distinguished
            Encoding Rules (DER).";
     }

     /***********************************************/
     /*   Typedefs for ASN.1 structures from 5652   */
     /***********************************************/

     typedef cms {
       type binary;
       description
         "A ContentInfo structure, as specified in RFC 5652,
          encoded using ASN.1 distinguished encoding rules (DER),
          as specified in ITU-T X.690.";
       reference
         "RFC 5652:
            Cryptographic Message Syntax (CMS)
          ITU-T X.690:
            Information technology - ASN.1 encoding rules:
            Specification of Basic Encoding Rules (BER),
            Canonical Encoding Rules (CER) and Distinguished
            Encoding Rules (DER).";
     }

     typedef data-content-cms {
       type cms;
       description
         "A CMS structure whose top-most content type MUST be the
          data content type, as described by Section 4 in RFC 5652.";
       reference
         "RFC 5652: Cryptographic Message Syntax (CMS)";
     }

     typedef signed-data-cms {
       type cms;
       description
         "A CMS structure whose top-most content type MUST be the
          signed-data content type, as described by Section 5 in
          RFC 5652.";
       reference
         "RFC 5652: Cryptographic Message Syntax (CMS)";
     }

     typedef enveloped-data-cms {
       type cms;
       description
         "A CMS structure whose top-most content type MUST be the
          enveloped-data content type, as described by Section 6
          in RFC 5652.";
       reference
         "RFC 5652: Cryptographic Message Syntax (CMS)";
     }

     typedef digested-data-cms {
       type cms;
       description
         "A CMS structure whose top-most content type MUST be the
          digested-data content type, as described by Section 7
          in RFC 5652.";
       reference
         "RFC 5652: Cryptographic Message Syntax (CMS)";
     }

     typedef encrypted-data-cms {
       type cms;
       description
         "A CMS structure whose top-most content type MUST be the
          encrypted-data content type, as described by Section 8
          in RFC 5652.";
       reference
         "RFC 5652: Cryptographic Message Syntax (CMS)";
     }

     typedef authenticated-data-cms {
       type cms;
       description
         "A CMS structure whose top-most content type MUST be the
          authenticated-data content type, as described by Section 9
          in RFC 5652.";
       reference
         "RFC 5652: Cryptographic Message Syntax (CMS)";
     }

     /***************************************************/
     /*   Typedefs for structures related to RFC 4253   */
     /***************************************************/

     typedef ssh-host-key {
       type binary;
       description
         "The binary public key data for this SSH key, as
          specified by RFC 4253, Section 6.6, i.e.:

            string    certificate or public key format
                      identifier
            byte[n]   key/certificate data.";
       reference
         "RFC 4253: The Secure Shell (SSH) Transport Layer
                    Protocol";
     }

     /*********************************************************/
     /*   Typedefs for ASN.1 structures related to RFC 5280   */
     /*********************************************************/

     typedef trust-anchor-cert-x509 {
       type x509;
       description
         "A Certificate structure that MUST encode a self-signed
          root certificate.";
     }

     typedef end-entity-cert-x509 {
       type x509;
       description
         "A Certificate structure that MUST encode a certificate
          that is neither self-signed nor having Basic constraint
          CA true.";
     }

     /*********************************************************/
     /*   Typedefs for ASN.1 structures related to RFC 5652   */
     /*********************************************************/

     typedef trust-anchor-cert-cms {
       type signed-data-cms;
       description
         "A CMS SignedData structure that MUST contain the chain of
          X.509 certificates needed to authenticate the certificate
          presented by a client or end-entity.

          The CMS MUST contain only a single chain of certificates.
          The client or end-entity certificate MUST only authenticate
          to last intermediate CA certificate listed in the chain.

          In all cases, the chain MUST include a self-signed root
          certificate.  In the case where the root certificate is
          itself the issuer of the client or end-entity certificate,
          only one certificate is present.

          This CMS structure MAY (as applicable where this type is
          used) also contain suitably fresh (as defined by local
          policy) revocation objects with which the device can
          verify the revocation status of the certificates.

          This CMS encodes the degenerate form of the SignedData
          structure that is commonly used to disseminate X.509
          certificates and revocation objects (RFC 5280).";
       reference
         "RFC 5280:
            Internet X.509 Public Key Infrastructure Certificate
            and Certificate Revocation List (CRL) Profile.";
     }
     typedef end-entity-cert-cms {
       type signed-data-cms;
       description
         "A CMS SignedData structure that MUST contain the end
          entity certificate itself, and MAY contain any number
          of intermediate certificates leading up to a trust
          anchor certificate.  The trust anchor certificate
          MAY be included as well.

          The CMS MUST contain a single end entity certificate.
          The CMS MUST NOT contain any spurious certificates.

          This CMS structure MAY (as applicable where this type is
          used) also contain suitably fresh (as defined by local
          policy) revocation objects with which the device can
          verify the revocation status of the certificates.

          This CMS encodes the degenerate form of the SignedData
          structure that is commonly used to disseminate X.509
          certificates and revocation objects (RFC 5280).";
       reference
         "RFC 5280:
            Internet X.509 Public Key Infrastructure Certificate
            and Certificate Revocation List (CRL) Profile.";
     }

     /**********************************************/
     /*   Groupings for keys and/or certificates   */
     /**********************************************/

     grouping symmetric-key-grouping {
       description
         "A symmetric key and algorithm.";
       leaf algorithm {
         type identityref {
          base "ct:encryption-algorithm";
        } encryption-algorithm-t;
         mandatory true;
         description
           "The algorithm to be used when generating the key.";
         reference
           "RFC CCCC: Common YANG Data Types for Cryptography";
       }
       choice key-type {
         mandatory true;
         description
           "Choice between key types.";
         leaf key {
           nacm:default-deny-all;
           type binary;
           description
             "The binary value of the key.  The interpretation of
              the value is defined by 'algorithm'.  For example,
              FIXME.";
           reference
             "RFC XXXX: FIXME";
         }
         leaf hidden-key {
           nacm:default-deny-write;
           type empty;
           description
             "A permanently hidden key.  How such keys are created
              is outside the scope of this module.";
         }
       }
     }

     grouping public-key-grouping {
       description
         "A public key and its associated algorithm.";
       leaf algorithm {
         nacm:default-deny-write;
         type asymmetric-key-algorithm-ref; asymmetric-key-algorithm-t;
         mandatory true;
         description
           "Identifies the key's algorithm.";
         reference
           "RFC CCCC: Common YANG Data Types for Cryptography";
       }
       leaf public-key {
         nacm:default-deny-write;
         type binary;
         mandatory true;
         description
           "The binary value of the public key.  The interpretation
            of the value is defined by 'algorithm'.  For example,
            a DSA key is an integer, an RSA key is represented as
            RSAPublicKey per RFC 8017, and an ECC key is represented
            using the 'publicKey' described in RFC 5915.";
         reference
           "RFC 8017: Public-Key Cryptography Standards (PKCS) #1:
                      RSA Cryptography Specifications Version 2.2.
            RFC 5915: Elliptic Curve Private Key Structure.";
       }
     }

     grouping asymmetric-key-pair-grouping {
       description
         "A private key and its associated public key and algorithm.";
       uses public-key-grouping;
       choice private-key-type {
         mandatory true;
         description
           "Choice between key types.";
         leaf private-key {
           nacm:default-deny-all;
           type binary;
           description
             "The value of the binary key.  The key's value is
              interpreted by the 'algorithm'.  For example, a DSA key
              is an integer, an RSA key is represented as RSAPrivateKey
              as defined in RFC 8017, and an ECC key is represented as
              ECPrivateKey as defined in RFC 5915.";
           reference
             "RFC 8017: Public-Key Cryptography Standards (PKCS) #1:
                        RSA Cryptography Specifications Version 2.2.
              RFC 5915: Elliptic Curve Private Key Structure.";
         }
         leaf hidden-private-key {
           nacm:default-deny-write;
           type empty;
           description
             "A permanently hidden key.  How such keys are created
              is outside the scope of this module.";
         }
       }
     }

     grouping trust-anchor-cert-grouping {
       description
         "A trust anchor certificate, and a notification for when
          it is about to (or already has) expire.";
       leaf cert {
         nacm:default-deny-write;
         type trust-anchor-cert-cms;
         description
           "The binary certificate data for this certificate.";
         reference
           "RFC YYYY: Common YANG Data Types for Cryptography";
       }
       notification certificate-expiration {
         description
           "A notification indicating that the configured certificate
            is either about to expire or has already expired.  When to
            send notifications is an implementation specific decision,
            but it is RECOMMENDED that a notification be sent once a
            month for 3 months, then once a week for four weeks, and
            then once a day thereafter until the issue is resolved.";
         leaf expiration-date {
           type yang:date-and-time;
           mandatory true;
           description
             "Identifies the expiration date on the certificate.";
         }
       }
     }

     grouping trust-anchor-certs-grouping {
       description
         "A list of trust anchor certificates, and a notification
          for when one is about to (or already has) expire.";
       leaf-list cert {
         nacm:default-deny-write;
         type trust-anchor-cert-cms;
         description
           "The binary certificate data for this certificate.";
         reference
           "RFC YYYY: Common YANG Data Types for Cryptography";
       }
       notification certificate-expiration {
         description
           "A notification indicating that the configured certificate
            is either about to expire or has already expired.  When to
            send notifications is an implementation specific decision,
            but it is RECOMMENDED that a notification be sent once a
            month for 3 months, then once a week for four weeks, and
            then once a day thereafter until the issue is resolved.";
         leaf expiration-date {
           type yang:date-and-time;
           mandatory true;
           description
             "Identifies the expiration date on the certificate.";
         }
       }
     }

     grouping end-entity-cert-grouping {
       description
         "An end entity certificate, and a notification for when
          it is about to (or already has) expire.  Implementations
          SHOULD assert that, where used, the end entity certificate
          contains the expected public key.";
       leaf cert {
         nacm:default-deny-write;
         type end-entity-cert-cms;
         description
           "The binary certificate data for this certificate.";
         reference
           "RFC YYYY: Common YANG Data Types for Cryptography";
       }
       notification certificate-expiration {
         description
           "A notification indicating that the configured certificate
            is either about to expire or has already expired.  When to
            send notifications is an implementation specific decision,
            but it is RECOMMENDED that a notification be sent once a
            month for 3 months, then once a week for four weeks, and
            then once a day thereafter until the issue is resolved.";
         leaf expiration-date {
           type yang:date-and-time;
           mandatory true;
           description
             "Identifies the expiration date on the certificate.";
         }
       }
     }

     grouping end-entity-certs-grouping {
       description
         "A list of end entity certificates, and a notification for
          when one is about to (or already has) expire.";
       leaf-list cert {
         nacm:default-deny-write;
         type end-entity-cert-cms;
         description
           "The binary certificate data for this certificate.";
         reference
           "RFC YYYY: Common YANG Data Types for Cryptography";
       }
       notification certificate-expiration {
         description
           "A notification indicating that the configured certificate
            is either about to expire or has already expired.  When to
            send notifications is an implementation specific decision,
            but it is RECOMMENDED that a notification be sent once a
            month for 3 months, then once a week for four weeks, and
            then once a day thereafter until the issue is resolved.";
         leaf expiration-date {
           type yang:date-and-time;
           mandatory true;
           description
             "Identifies the expiration date on the certificate.";

         }
       }
     }

     grouping asymmetric-key-pair-with-cert-grouping {
       description
         "A private/public key pair and an associated certificate.
          Implementations SHOULD assert that certificates contain
          the matching public key.";
       uses asymmetric-key-pair-grouping;
       uses end-entity-cert-grouping;
       action generate-certificate-signing-request {
         nacm:default-deny-all;
         description
           "Generates a certificate signing request structure for
            the associated asymmetric key using the passed subject
            and attribute values.  The specified assertions need
            to be appropriate for the certificate's use.  For
            example, an entity certificate for a TLS server
            SHOULD have values that enable clients to satisfy
            RFC 6125 processing.";
         input {
           leaf subject {
             type binary;
             mandatory true;
             description
               "The 'subject' field per the CertificationRequestInfo
                 structure as specified by RFC 2986, Section 4.1
                 encoded using the ASN.1 distinguished encoding
                 rules (DER), as specified in ITU-T X.690.";
             reference
               "RFC 2986:
                  PKCS #10: Certification Request Syntax
                            Specification Version 1.7.
                ITU-T X.690:
                  Information technology - ASN.1 encoding rules:
                  Specification of Basic Encoding Rules (BER),
                  Canonical Encoding Rules (CER) and Distinguished
                  Encoding Rules (DER).";
           }
           leaf attributes {
             type binary; // FIXME: does this need to be mandatory?
             description
               "The 'attributes' field from the structure
                CertificationRequestInfo as specified by RFC 2986,
                Section 4.1 encoded using the ASN.1 distinguished
                encoding rules (DER), as specified in ITU-T X.690.";
             reference
               "RFC 2986:
                  PKCS #10: Certification Request Syntax
                            Specification Version 1.7.
                ITU-T X.690:
                  Information technology - ASN.1 encoding rules:
                  Specification of Basic Encoding Rules (BER),
                  Canonical Encoding Rules (CER) and Distinguished
                  Encoding Rules (DER).";
           }
         }
         output {
           leaf certificate-signing-request {
             type binary;
             mandatory true;
             description
               "A CertificationRequest structure as specified by
                RFC 2986, Section 4.2 encoded using the ASN.1
                distinguished encoding rules (DER), as specified
                in ITU-T X.690.";
             reference
               "RFC 2986:
                  PKCS #10: Certification Request Syntax
                            Specification Version 1.7.
                ITU-T X.690:
                  Information technology - ASN.1 encoding rules:
                  Specification of Basic Encoding Rules (BER),
                  Canonical Encoding Rules (CER) and Distinguished
                  Encoding Rules (DER).";
           }
         }
       } // generate-certificate-signing-request
     } // asymmetric-key-pair-with-cert-grouping

     grouping asymmetric-key-pair-with-certs-grouping {
       description
         "A private/public key pair and associated certificates.
          Implementations SHOULD assert that certificates contain
          the matching public key.";
       uses asymmetric-key-pair-grouping;
       container certificates {
         nacm:default-deny-write;
         description
           "Certificates associated with this asymmetric key.
            More than one certificate supports, for instance,
            a TPM-protected asymmetric key that has both IDevID
            and LDevID certificates associated.";
         list certificate {
           key "name";
           description
             "A certificate for this asymmetric key.";
           leaf name {
             type string;
             description
               "An arbitrary name for the certificate.  If the name
                matches the name of a certificate that exists
                independently in <operational> (i.e., an IDevID),
                then the 'cert' node MUST NOT be configured.";
           }
           uses end-entity-cert-grouping;
         }
       } // certificates
       action generate-certificate-signing-request {
         nacm:default-deny-all;
         description
           "Generates a certificate signing request structure for
            the associated asymmetric key using the passed subject
            and attribute values.  The specified assertions need
            to be appropriate for the certificate's use.  For
            example, an entity certificate for a TLS server
            SHOULD have values that enable clients to satisfy
            RFC 6125 processing.";
         input {
           leaf subject {
             type binary;
             mandatory true;
             description
               "The 'subject' field per the CertificationRequestInfo
                 structure as specified by RFC 2986, Section 4.1
                 encoded using the ASN.1 distinguished encoding
                 rules (DER), as specified in ITU-T X.690.";
             reference
               "RFC 2986:
                  PKCS #10: Certification Request Syntax
                            Specification Version 1.7.
                ITU-T X.690:
                  Information technology - ASN.1 encoding rules:
                  Specification of Basic Encoding Rules (BER),
                  Canonical Encoding Rules (CER) and Distinguished
                  Encoding Rules (DER).";
           }
           leaf attributes {
             type binary; // FIXME: does this need to be mandatory?
             description
               "The 'attributes' field from the structure
                CertificationRequestInfo as specified by RFC 2986,
                Section 4.1 encoded using the ASN.1 distinguished
                encoding rules (DER), as specified in ITU-T X.690.";
             reference
               "RFC 2986:
                  PKCS #10: Certification Request Syntax
                            Specification Version 1.7.
                ITU-T X.690:
                  Information technology - ASN.1 encoding rules:
                  Specification of Basic Encoding Rules (BER),
                  Canonical Encoding Rules (CER) and Distinguished
                  Encoding Rules (DER).";
           }
         }
         output {
           leaf certificate-signing-request {
             type binary;
             mandatory true;
             description
               "A CertificationRequest structure as specified by
                RFC 2986, Section 4.2 encoded using the ASN.1
                distinguished encoding rules (DER), as specified
                in ITU-T X.690.";
             reference
               "RFC 2986:
                  PKCS #10: Certification Request Syntax
                            Specification Version 1.7.
                ITU-T X.690:
                  Information technology - ASN.1 encoding rules:
                  Specification of Basic Encoding Rules (BER),
                  Canonical Encoding Rules (CER) and Distinguished
                  Encoding Rules (DER).";
           }
         }
       } // generate-certificate-signing-request
     } // asymmetric-key-pair-with-certs-grouping
   }

   <CODE ENDS>

3.  Security Considerations

3.1.  Support for Algorithms

   In order to use YANG identities for algorithm identifiers, only the
   most commonly used RSA key lengths are supported for the RSA
   algorithm.  Additional key lengths can be defined in another module
   or added into a future version of this document.

   This document limits the number of elliptical curves supported.  This
   was done to match industry trends and IETF best practice (e.g.,
   matching work being done in TLS 1.3).  If additional algorithms are
   needed, they can be defined by another module or added into a future
   version of this document.

3.2.  No Support for CRMF

   This document uses PKCS #10 [RFC2986] for the "generate-certificate-
   signing-request" action.  The use of Certificate Request Message
   Format (CRMF) [RFC4211] was considered, but is was unclear if there
   was market demand for it.  If it is desired to support CRMF in the
   future, a backwards compatible solution can be defined at that time.

3.3.  Access to Data Nodes

   The YANG module in this document defines "grouping" statements that
   are 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.

   Since the module in this document only define groupings, these
   considerations are primarily for the designers of other modules that
   use these groupings.

   There are a number of data nodes defined by the grouping statements
   that are writable/creatable/deletable (i.e., config true, which is
   the default).  Some of 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:

      *: All of the data nodes defined by all the groupings are
         considered sensitive to write operations.  For instance, the
         modification of a public key or a certificate can dramatically
         alter the implemented security policy.  For this reason, the
         NACM extension "default-deny-write" has been applied to all the
         data nodes defined by all the groupings.

   Some of the readable data nodes in the 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:

      /private-key:  The "private-key" node defined in the "asymmetric-
         key-pair-grouping" grouping is additionally sensitive to read
         operations such that, in normal use cases, it should never be
         returned to a client.  For this reason, the NACM extension
         "default-deny-all" has been applied to it here.

   Some of the operations in this YANG module may be considered
   sensitive or vulnerable in some network environments.  It is thus
   important to control access to these operations.  These are the
   operations and their sensitivity/vulnerability:

      *: All of the "action" statements defined by groupings SHOULD only
         be executed by authorized users.  For this reason, the NACM
         extension "default-deny-all" has been applied to all of them.
         Note that NACM uses "default-deny-all" to protect "RPC" and
         "action" statements; it does not define, e.g., an extension
         called "default-deny-execute".

      generate-certificate-signing-request:  For this action, it is
         RECOMMENDED that implementations assert channel binding
         [RFC5056], so as to ensure that the application layer that sent
         the request is the same as the device authenticated when the
         secure transport layer was established.

4.  IANA Considerations

4.1.  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-crypto-types
      Registrant Contact: The NETCONF WG of the IETF.
      XML: N/A, the requested URI is an XML namespace.

4.2.  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-crypto-types
      namespace:    urn:ietf:params:xml:ns:yang:ietf-crypto-types
      prefix:       ct
      reference:    RFC XXXX

5.  References

5.1.  Normative References

   [ITU.X690.2015]
              International Telecommunication Union, "Information
              Technology - ASN.1 encoding rules: Specification of Basic
              Encoding Rules (BER), Canonical Encoding Rules (CER) and
              Distinguished Encoding Rules (DER)", ITU-T Recommendation
              X.690, ISO/IEC 8825-1, August 2015,
              <https://www.itu.int/rec/T-REC-X.690/>.

   [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>.

   [RFC2404]  Madson, C. and R. Glenn, "The Use of HMAC-SHA-1-96 within
              ESP and AH", RFC 2404, DOI 10.17487/RFC2404, November
              1998, <https://www.rfc-editor.org/info/rfc2404>.

   [RFC3565]  Schaad, J., "Use of the Advanced Encryption Standard (AES)
              Encryption Algorithm in Cryptographic Message Syntax
              (CMS)", RFC 3565, DOI 10.17487/RFC3565, July 2003,
              <https://www.rfc-editor.org/info/rfc3565>.

   [RFC3686]  Housley, R., "Using Advanced Encryption Standard (AES)
              Counter Mode With IPsec Encapsulating Security Payload
              (ESP)", RFC 3686, DOI 10.17487/RFC3686, January 2004,
              <https://www.rfc-editor.org/info/rfc3686>.

   [RFC4106]  Viega, J. and D. McGrew, "The Use of Galois/Counter Mode
              (GCM) in IPsec Encapsulating Security Payload (ESP)",
              RFC 4106, DOI 10.17487/RFC4106, June 2005,
              <https://www.rfc-editor.org/info/rfc4106>.

   [RFC4253]  Ylonen, T. and C. Lonvick, Ed., "The Secure Shell (SSH)
              Transport Layer Protocol", RFC 4253, DOI 10.17487/RFC4253,
              January 2006, <https://www.rfc-editor.org/info/rfc4253>.

   [RFC4279]  Eronen, P., Ed. and H. Tschofenig, Ed., "Pre-Shared Key
              Ciphersuites for Transport Layer Security (TLS)",
              RFC 4279, DOI 10.17487/RFC4279, December 2005,
              <https://www.rfc-editor.org/info/rfc4279>.

   [RFC4309]  Housley, R., "Using Advanced Encryption Standard (AES) CCM
              Mode with IPsec Encapsulating Security Payload (ESP)",
              RFC 4309, DOI 10.17487/RFC4309, December 2005,
              <https://www.rfc-editor.org/info/rfc4309>.

   [RFC4494]  Song, JH., Poovendran, R., and J. Lee, "The AES-CMAC-96
              Algorithm and Its Use with IPsec", RFC 4494,
              DOI 10.17487/RFC4494, June 2006,
              <https://www.rfc-editor.org/info/rfc4494>.

   [RFC4543]  McGrew, D. and J. Viega, "The Use of Galois Message
              Authentication Code (GMAC) in IPsec ESP and AH", RFC 4543,
              DOI 10.17487/RFC4543, May 2006,
              <https://www.rfc-editor.org/info/rfc4543>.

   [RFC4868]  Kelly, S. and S. Frankel, "Using HMAC-SHA-256, HMAC-SHA-
              384, and HMAC-SHA-512 with IPsec", RFC 4868,
              DOI 10.17487/RFC4868, May 2007,
              <https://www.rfc-editor.org/info/rfc4868>.

   [RFC5280]  Cooper, D., Santesson, S., Farrell, S., Boeyen, S.,
              Housley, R., and W. Polk, "Internet X.509 Public Key
              Infrastructure Certificate and Certificate Revocation List
              (CRL) Profile", RFC 5280, DOI 10.17487/RFC5280, May 2008,
              <https://www.rfc-editor.org/info/rfc5280>.

   [RFC5652]  Housley, R., "Cryptographic Message Syntax (CMS)", STD 70,
              RFC 5652, DOI 10.17487/RFC5652, September 2009,
              <https://www.rfc-editor.org/info/rfc5652>.

   [RFC5656]  Stebila, D. and J. Green, "Elliptic Curve Algorithm
              Integration in the Secure Shell Transport Layer",
              RFC 5656, DOI 10.17487/RFC5656, December 2009,
              <https://www.rfc-editor.org/info/rfc5656>.

   [RFC6187]  Igoe, K. and D. Stebila, "X.509v3 Certificates for Secure
              Shell Authentication", RFC 6187, DOI 10.17487/RFC6187,
              March 2011, <https://www.rfc-editor.org/info/rfc6187>.

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

   [RFC7919]  Gillmor, D., "Negotiated Finite Field Diffie-Hellman
              Ephemeral Parameters for Transport Layer Security (TLS)",
              RFC 7919, DOI 10.17487/RFC7919, August 2016,
              <https://www.rfc-editor.org/info/rfc7919>.

   [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>.

   [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>.

   [RFC8268]  Baushke, M., "More Modular Exponentiation (MODP) Diffie-
              Hellman (DH) Key Exchange (KEX) Groups for Secure Shell
              (SSH)", RFC 8268, DOI 10.17487/RFC8268, December 2017,
              <https://www.rfc-editor.org/info/rfc8268>.

   [RFC8332]  Bider, D., "Use of RSA Keys with SHA-256 and SHA-512 in
              the Secure Shell (SSH) Protocol", RFC 8332,
              DOI 10.17487/RFC8332, March 2018,
              <https://www.rfc-editor.org/info/rfc8332>.

   [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>.

   [RFC8422]  Nir, Y., Josefsson, S., and M. Pegourie-Gonnard, "Elliptic
              Curve Cryptography (ECC) Cipher Suites for Transport Layer
              Security (TLS) Versions 1.2 and Earlier", RFC 8422,
              DOI 10.17487/RFC8422, August 2018,
              <https://www.rfc-editor.org/info/rfc8422>.

   [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>.

5.2.  Informative References

   [RFC2986]  Nystrom, M. and B. Kaliski, "PKCS #10: Certification
              Request Syntax Specification Version 1.7", RFC 2986,
              DOI 10.17487/RFC2986, November 2000,
              <https://www.rfc-editor.org/info/rfc2986>.

   [RFC3174]  Eastlake 3rd, D. and P. Jones, "US Secure Hash Algorithm 1
              (SHA1)", RFC 3174, DOI 10.17487/RFC3174, September 2001,
              <https://www.rfc-editor.org/info/rfc3174>.

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

   [RFC4211]  Schaad, J., "Internet X.509 Public Key Infrastructure
              Certificate Request Message Format (CRMF)", RFC 4211,
              DOI 10.17487/RFC4211, September 2005,
              <https://www.rfc-editor.org/info/rfc4211>.

   [RFC4493]  Song, JH., Poovendran, R., Lee, J., and T. Iwata, "The
              AES-CMAC Algorithm", RFC 4493, DOI 10.17487/RFC4493, June
              2006, <https://www.rfc-editor.org/info/rfc4493>.

   [RFC5056]  Williams, N., "On the Use of Channel Bindings to Secure
              Channels", RFC 5056, DOI 10.17487/RFC5056, November 2007,
              <https://www.rfc-editor.org/info/rfc5056>.

   [RFC5915]  Turner, S. and D. Brown, "Elliptic Curve Private Key
              Structure", RFC 5915, DOI 10.17487/RFC5915, June 2010,
              <https://www.rfc-editor.org/info/rfc5915>.

   [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>.

   [RFC6125]  Saint-Andre, P. and J. Hodges, "Representation and
              Verification of Domain-Based Application Service Identity
              within Internet Public Key Infrastructure Using X.509
              (PKIX) Certificates in the Context of Transport Layer
              Security (TLS)", RFC 6125, DOI 10.17487/RFC6125, March
              2011, <https://www.rfc-editor.org/info/rfc6125>.

   [RFC6234]  Eastlake 3rd, D. and T. Hansen, "US Secure Hash Algorithms
              (SHA and SHA-based HMAC and HKDF)", RFC 6234,
              DOI 10.17487/RFC6234, May 2011,
              <https://www.rfc-editor.org/info/rfc6234>.

   [RFC6239]  Igoe, K., "Suite B Cryptographic Suites for Secure Shell
              (SSH)", RFC 6239, DOI 10.17487/RFC6239, May 2011,
              <https://www.rfc-editor.org/info/rfc6239>.

   [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>.

   [RFC6507]  Groves, M., "Elliptic Curve-Based Certificateless
              Signatures for Identity-Based Encryption (ECCSI)",
              RFC 6507, DOI 10.17487/RFC6507, February 2012,
              <https://www.rfc-editor.org/info/rfc6507>.

   [RFC8017]  Moriarty, K., Ed., Kaliski, B., Jonsson, J., and A. Rusch,
              "PKCS #1: RSA Cryptography Specifications Version 2.2",
              RFC 8017, DOI 10.17487/RFC8017, November 2016,
              <https://www.rfc-editor.org/info/rfc8017>.

   [RFC8032]  Josefsson, S. and I. Liusvaara, "Edwards-Curve Digital
              Signature Algorithm (EdDSA)", RFC 8032,
              DOI 10.17487/RFC8032, January 2017,
              <https://www.rfc-editor.org/info/rfc8032>.

   [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>.

   [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>.

   [RFC8439]  Nir, Y. and A. Langley, "ChaCha20 and Poly1305 for IETF
              Protocols", RFC 8439, DOI 10.17487/RFC8439, June 2018,
              <https://www.rfc-editor.org/info/rfc8439>.

Appendix A.  Examples

A.1.  The "asymmetric-key-pair-with-certs-grouping" Grouping

   The following example module has been constructed to illustrate use
   of the "asymmetric-key-pair-with-certs-grouping" grouping defined in
   the "ietf-crypto-types" module.

   Note that the "asymmetric-key-pair-with-certs-grouping" grouping uses
   both the "asymmetric-key-pair-grouping" and "end-entity-cert-
   grouping" groupings, and that the "asymmetric-key-pair-grouping"
   grouping uses the "public-key-grouping" grouping.  Thus, a total of
   four of the five groupings defined in the "ietf-crypto-types" module
   are illustrated through the use of this one grouping.  The only
   grouping not represented is the "trust-anchor-cert-grouping"
   grouping.

   module ex-crypto-types-usage {
     yang-version 1.1;

     namespace "http://example.com/ns/example-crypto-types-usage";
     prefix "ectu";

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

     organization
      "Example Corporation";

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

     description
      "This module illustrates the grouping
       defined in the crypto-types draft called
       'asymmetric-key-pair-with-certs-grouping'.";

     revision "1001-01-01" {
       description
        "Initial version";
       reference
        "RFC ????: Usage Example for RFC XXXX";
     }

     container keys {
       description
         "A container of keys.";
       list key {
         key name;
         leaf name {
           type string;
           description
             "An arbitrary name for this key.";
         }
         uses ct:asymmetric-key-pair-with-certs-grouping;
         description
           "An asymmetric key pair with associated certificates.";
       }
     }
   }
   Given the above example usage module, the following example
   illustrates some configured keys.

   <keys xmlns="http://example.com/ns/example-crypto-types-usage">
     <key>
       <name>ex-key</name>
       <algorithm
         xmlns:ct="urn:ietf:params:xml:ns:yang:ietf-crypto-types">
         ct:rsa2048
       </algorithm>
       <algorithm>rsa2048</algorithm>
       <public-key>base64encodedvalue==</public-key>
       <private-key>base64encodedvalue==</private-key>
       <certificates>
         <certificate>
           <name>ex-cert</name>
           <cert>base64encodedvalue==</cert>
         </certificate>
       </certificates>
     </key>
     <key>
       <name>ex-hidden-key</name>
       <algorithm
         xmlns:ct="urn:ietf:params:xml:ns:yang:ietf-crypto-types">
         ct:rsa2048
       </algorithm>
       <algorithm>rsa2048</algorithm>
       <public-key>base64encodedvalue==</public-key>
       <hidden-private-key/>
       <certificates>
         <certificate>
           <name>ex-hidden-key-cert</name>
           <cert>base64encodedvalue==</cert>
         </certificate>
       </certificates>
     </key>
   </keys>

A.2.  The "generate-certificate-signing-request" Action

   The following example illustrates the "generate-certificate-signing-
   request" action in use with the NETCONF protocol.

   REQUEST

   <rpc message-id="101"
     xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
     <action xmlns="urn:ietf:params:xml:ns:yang:1">
       <keys xmlns="http://example.com/ns/example-crypto-types-usage">
         <key>
           <name>ex-key-sect571r1</name>
           <generate-certificate-signing-request>
             <subject>base64encodedvalue==</subject>
             <attributes>base64encodedvalue==</attributes>
           </generate-certificate-signing-request>
         </key>
       </keys>
     </action>
   </rpc>

   RESPONSE

   <rpc-reply message-id="101"
      xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
      <certificate-signing-request
        xmlns="http://example.com/ns/example-crypto-types-usage">
        base64encodedvalue==
      </certificate-signing-request>
   </rpc-reply>

A.3.  The "certificate-expiration" Notification

   The following example illustrates the "certificate-expiration"
   notification in use with the NETCONF protocol.

   <notification
     xmlns="urn:ietf:params:xml:ns:netconf:notification:1.0">
     <eventTime>2018-05-25T00:01:00Z</eventTime>
     <keys xmlns="http://example.com/ns/example-crypto-types-usage">
       <key>
         <name>locally-defined key</name>
         <certificates>
           <certificate>
             <name>my-cert</name>
             <certificate-expiration>
               <expiration-date>
                 2018-08-05T14:18:53-05:00
               </expiration-date>
             </certificate-expiration>
           </certificate>
         </certificates>
       </key>
     </keys>
   </notification>

Appendix B.  Change Log

B.1.  I-D to 00

   o  Removed groupings and notifications.

   o  Added typedefs for identityrefs.

   o  Added typedefs for other RFC 5280 structures.

   o  Added typedefs for other RFC 5652 structures.

   o  Added convenience typedefs for RFC 4253, RFC 5280, and RFC 5652.

B.2.  00 to 01

   o  Moved groupings from the draft-ietf-netconf-keystore here.

B.3.  01 to 02

   o  Removed unwanted "mandatory" and "must" statements.

   o  Added many new crypto algorithms (thanks Haiguang!)

   o  Clarified in asymmetric-key-pair-with-certs-grouping, in
      certificates/certificate/name/description, that if the name MUST
      NOT match the name of a certificate that exists independently in
      <operational>, enabling certs installed by the manufacturer (e.g.,
      an IDevID).

B.4.  02 to 03

   o  renamed base identity 'asymmetric-key-encryption-algorithm' to
      'asymmetric-key-algorithm'.

   o  added new 'asymmetric-key-algorithm' identities for secp192r1,
      secp224r1, secp256r1, secp384r1, and secp521r1.

   o  removed 'mac-algorithm' identities for mac-aes-128-ccm, mac-aes-
      192-ccm, mac-aes-256-ccm, mac-aes-128-gcm, mac-aes-192-gcm, mac-
      aes-256-gcm, and mac-chacha20-poly1305.

   o  for all -cbc and -ctr identities, renamed base identity
      'symmetric-key-encryption-algorithm' to 'encryption-algorithm'.

   o  for all -ccm and -gcm identities, renamed base identity
      'symmetric-key-encryption-algorithm' to 'encryption-and-mac-
      algorithm' and renamed the identity to remove the "enc-" prefix.

   o  for all the 'signature-algorithm' based identities, renamed from
      'rsa-*' to 'rsassa-*'.

   o  removed all of the "x509v3-" prefixed 'signature-algorithm' based
      identities.

   o  added 'key-exchange-algorithm' based identities for 'rsaes-oaep'
      and 'rsaes-pkcs1-v1_5'.

   o  renamed typedef 'symmetric-key-encryption-algorithm-ref' to
      'symmetric-key-algorithm-ref'.

   o  renamed typedef 'asymmetric-key-encryption-algorithm-ref' to
      'asymmetric-key-algorithm-ref'.

   o  added typedef 'encryption-and-mac-algorithm-ref'.

   o  Updated copyright date, boilerplate template, affiliation, and
      folding algorithm.

B.5.  03 to 04

   o  ran YANG module through formatter.

B.6.  04 to 05

   o  fixed broken symlink causing reformatted YANG module to not show.

B.7.  05 to 06

   o  Added NACM annotations.

   o  Updated Security Considerations section.

   o  Added 'asymmetric-key-pair-with-cert-grouping' grouping.

   o  Removed text from 'permanently-hidden' enum regarding such keys
      not being backed up or restored.

   o  Updated the boilerplate text in module-level "description"
      statement to match copyeditor convention.

   o  Added an explanation to the 'public-key-grouping' and 'asymmetric-
      key-pair-grouping' statements as for why the nodes are not
      mandatory (e.g., because they may exist only in <operational>.

   o  Added 'must' expressions to the 'public-key-grouping' and
      'asymmetric-key-pair-grouping' statements ensuring sibling nodes
      are either all exist or do not all exist.

   o  Added an explanation to the 'permanently-hidden' that the value
      cannot be configured directly by clients and servers MUST fail any
      attempt to do so.

   o  Added 'trust-anchor-certs-grouping' and 'end-entity-certs-
      grouping' (the plural form of existing groupings).

   o  Now states that keys created in <operational> by the *-hidden-key
      actions are bound to the lifetime of the parent 'config true'
      node, and that subsequent invocations of either action results in
      a failure.

B.8.  06 to 07

   o  Added clarifications that implementations SHOULD assert that
      configured certificates contain the matching public key.

   o  Replaced the 'generate-hidden-key' and 'install-hidden-key'
      actions with special 'crypt-hash' -like input/output values.

B.9.  07 to 08

   o  Removed the 'generate-key and 'hidden-key' features.

   o  Added grouping symmetric-key-grouping

   o  Modified 'asymmetric-key-pair-grouping' to have a 'choice'
      statement for the keystone module to augment into, as well as
      replacing the 'union' with leafs (having different NACM settings.

B.10.  08 to 09

   o  Converting algorithm from identities to enumerations.

Acknowledgements

   The authors would like to thank for following for lively discussions
   on list and in the halls (ordered by last name): Martin Bjorklund,
   Nick Hancock, Balazs Kovacs, Juergen Schoenwaelder, Eric Voit, and
   Liang Xia.

Authors' Addresses

   Kent Watsen
   Watsen Networks

   EMail: kent+ietf@watsen.net

   Wang Haiguang
   Huawei

   EMail: wang.haiguang.shieldlab@huawei.com