Common YANG Data Types for Cryptography
draft-ietf-netconf-crypto-types-06

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:

• 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:

• 2019-04-29 --> the publication date of this draft

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

• 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 working documents as Internet-Drafts. The list of current Internet-Drafts is at https://datatracker.ietf.org/drafts/current/.

Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress."

This Internet-Draft will expire on October 31, 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
• 2. The Crypto Types Module
• 2.1. Tree Diagram
• 2.2. YANG Module
• 3. Security Considerations
• 3.1. Support for Algorithms
• 3.2. No Support for CRMF
• 3.3. Access to Data Nodes
• 4. IANA Considerations
• 4.1. The IETF XML Registry
• 4.2. The YANG Module Names Registry
• 5. References
• 5.1. Normative References
• 5.2. Informative References
• Appendix A. Examples
• A.1. The "asymmetric-key-pair-with-certs-grouping" Grouping
• A.2. The "generate-hidden-key" Action
• A.3. The "install-hidden-key" Action
• A.4. The "generate-certificate-signing-request" Action
• A.5. The "certificate-expiration" Notification
• Appendix B. Change Log
• B.1. I-D to 00
• B.2. 00 to 01
• B.3. 01 to 02
• B.4. 02 to 03
• B.5. 03 to 04
• B.6. 04 to 05
• B.7. 05 to 06
• Acknowledgements
• Authors' Addresses

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 public-key-grouping:
    +---- algorithm?    asymmetric-key-algorithm-ref
    +---- public-key?   binary
  grouping asymmetric-key-pair-grouping:
    +---- algorithm?            asymmetric-key-algorithm-ref
    +---- public-key?           binary
    +---- private-key?          union
    +---x generate-hidden-key
    |  +---- input
    |     +---w algorithm    asymmetric-key-algorithm-ref
    +---x install-hidden-key
       +---- input
          +---w algorithm      asymmetric-key-algorithm-ref
          +---w public-key?    binary
          +---w private-key?   binary
  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
    +---- public-key?                            binary
    +---- private-key?                           union
    +---x generate-hidden-key
    |  +---- input
    |     +---w algorithm    asymmetric-key-algorithm-ref
    +---x install-hidden-key
    |  +---- input
    |     +---w algorithm      asymmetric-key-algorithm-ref
    |     +---w public-key?    binary
    |     +---w private-key?   binary
    +---- 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
    +---- public-key?                            binary
    +---- private-key?                           union
    +---x generate-hidden-key
    |  +---- input
    |     +---w algorithm    asymmetric-key-algorithm-ref
    +---x install-hidden-key
    |  +---- input
    |     +---w algorithm      asymmetric-key-algorithm-ref
    |     +---w public-key?    binary
    |     +---w private-key?   binary
    +---- 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@2019-04-29.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 2019-04-29 {
    description
      "Initial version";
    reference
      "RFC XXXX: Common YANG Data Types for Cryptography";
  }

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

  identity hash-algorithm {
    description
      "A base identity for hash algorithm verification.";
  }

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

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

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

  identity sha-512 {
    base hash-algorithm;
    description
      "The SHA-512 algorithm.";
    reference
      "RFC 6234: US Secure Hash Algorithms.";
  }

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

  identity asymmetric-key-algorithm {
    description
      "Base identity from which all asymmetric key
       encryption Algorithm.";
  }

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

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

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

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

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

  identity rsa15360 {
    base asymmetric-key-algorithm;
    description
      "The RSA algorithm using a 15360-bit key.";
    reference
      "RFC 8017:
         PKCS #1: RSA Cryptography Specifications Version 2.2.";
  }

  identity secp192r1 {
    base asymmetric-key-algorithm;
    description
      "The ECDSA algorithm using a NIST P256 Curve.";
    reference
      "RFC 6090:
         Fundamental Elliptic Curve Cryptography Algorithms.";
  }

  identity secp224r1 {
    base asymmetric-key-algorithm;
    description
      "The ECDSA algorithm using a NIST P256 Curve.";
    reference
      "RFC 6090:
         Fundamental Elliptic Curve Cryptography Algorithms.";
  }

  identity secp256r1 {
    base asymmetric-key-algorithm;
    description
      "The ECDSA algorithm using a NIST P256 Curve.";
    reference
      "RFC 6090:
         Fundamental Elliptic Curve Cryptography Algorithms.";
  }

  identity secp384r1 {
    base asymmetric-key-algorithm;
    description
      "The ECDSA algorithm using a NIST P256 Curve.";
    reference
      "RFC 6090:
         Fundamental Elliptic Curve Cryptography Algorithms.";
  }

  identity secp521r1 {
    base asymmetric-key-algorithm;
    description
      "The ECDSA algorithm using a NIST P256 Curve.";
    reference
      "RFC 6090:
         Fundamental Elliptic Curve Cryptography Algorithms.";
  }

  /*************************************/
  /*   Identities for MAC Algorithms   */
  /*************************************/

  identity mac-algorithm {
    description
      "A base identity for mac generation.";
  }

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

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

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

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

  identity hmac-sha2-256-128 {
    base mac-algorithm;
    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 hmac-sha2-384 {
    base mac-algorithm;
    description
      "Generating MAC using SHA2 hash function";
    reference
      "RFC 6234:
         US Secure Hash Algorithms (SHA and SHA-based HMAC and
         HKDF)";
  }

  identity hmac-sha2-384-192 {
    base mac-algorithm;
    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 hmac-sha2-512 {
    base mac-algorithm;
    description
      "Generating MAC using SHA2 hash function";
    reference
      "RFC 6234:
         US Secure Hash Algorithms (SHA and SHA-based HMAC and
         HKDF)";
  }

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

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

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

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

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

  identity aes-cmac-128 {
    base mac-algorithm;
    description
      "Generating MAC using Advanced Encryption Standard (AES)
       Cipher-based Message Authentication Code (CMAC)";
    reference
      "RFC 4493: The AES-CMAC Algorithm";
  }

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

  identity encryption-algorithm {
    description
      "A base identity for encryption algorithm.";
  }

  identity aes-128-cbc {
    base encryption-algorithm;
    description
      "Encrypt message with AES algorithm in CBC mode with a key
       length of 128 bits";
    reference
      "RFC 3565:
         Use of the Advanced Encryption Standard (AES) Encryption
         Algorithm in Cryptographic Message Syntax (CMS)";
  }

  identity aes-192-cbc {
    base encryption-algorithm;
    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 aes-256-cbc {
    base encryption-algorithm;
    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 aes-128-ctr {
    base encryption-algorithm;
    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 aes-192-ctr {
    base encryption-algorithm;
    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 aes-256-ctr {
    base encryption-algorithm;
    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)";
  }

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

  identity encryption-and-mac-algorithm {
    description
      "A base identity for encryption and MAC algorithm.";
  }

  identity aes-128-ccm {
    base encryption-and-mac-algorithm;
    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 aes-192-ccm {
    base encryption-and-mac-algorithm;
    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 aes-256-ccm {
    base encryption-and-mac-algorithm;
    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 aes-128-gcm {
    base encryption-and-mac-algorithm;
    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 aes-192-gcm {
    base encryption-and-mac-algorithm;
    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 {
    base encryption-and-mac-algorithm;
    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 chacha20-poly1305 {
    base encryption-and-mac-algorithm;
    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";
  }

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

  identity signature-algorithm {
    description
      "A base identity for asymmetric key encryption algorithm.";
  }

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

  identity rsassa-pkcs1-sha1 {
    base signature-algorithm;
    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 rsassa-pkcs1-sha256 {
    base signature-algorithm;
    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 rsassa-pkcs1-sha384 {
    base signature-algorithm;
    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 rsassa-pkcs1-sha512 {
    base signature-algorithm;
    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 rsassa-pss-rsae-sha256 {
    base signature-algorithm;
    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 rsassa-pss-rsae-sha384 {
    base signature-algorithm;
    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 rsassa-pss-rsae-sha512 {
    base signature-algorithm;
    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 rsassa-pss-pss-sha256 {
    base signature-algorithm;
    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
       OID";
    reference
      "RFC 8446:
         The Transport Layer Security (TLS) Protocol Version 1.3";
  }

  identity rsassa-pss-pss-sha384 {
    base signature-algorithm;
    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
       OID";
    reference
      "RFC 8446:
         The Transport Layer Security (TLS) Protocol Version 1.3";
  }

  identity rsassa-pss-pss-sha512 {
    base signature-algorithm;
    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
       OID";
    reference
      "RFC 8446:
         The Transport Layer Security (TLS) Protocol Version 1.3";
  }

  identity ecdsa-secp256r1-sha256 {
    base signature-algorithm;
    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 ecdsa-secp384r1-sha384 {
    base signature-algorithm;
    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 ecdsa-secp521r1-sha512 {
    base signature-algorithm;
    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 ed25519 {
    base signature-algorithm;
    description
      "The signature algorithm using EdDSA as defined in RFC 8032 or
       its successors.";
    reference
      "RFC 8032: Edwards-Curve Digital Signature Algorithm (EdDSA)";
  }

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

  identity eccsi {
    base signature-algorithm;
    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)";
  }

  /**********************************************/
  /*   Identities for key exchange algorithms   */
  /**********************************************/

  identity key-exchange-algorithm {
    description
      "A base identity for Diffie-Hellman based key exchange
       algorithm.";
  }

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

  identity dhe-ffdhe2048 {
    base key-exchange-algorithm;
    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 dhe-ffdhe3072 {
    base key-exchange-algorithm;
    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 dhe-ffdhe4096 {
    base key-exchange-algorithm;
    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 dhe-ffdhe6144 {
    base key-exchange-algorithm;
    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 dhe-ffdhe8192 {
    base key-exchange-algorithm;
    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 psk-dhe-ffdhe2048 {
    base key-exchange-algorithm;
    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 psk-dhe-ffdhe3072 {
    base key-exchange-algorithm;
    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 psk-dhe-ffdhe4096 {
    base key-exchange-algorithm;
    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 psk-dhe-ffdhe6144 {
    base key-exchange-algorithm;
    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 psk-dhe-ffdhe8192 {
    base key-exchange-algorithm;
    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 ecdhe-secp256r1 {
    base key-exchange-algorithm;
    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 ecdhe-secp384r1 {
    base key-exchange-algorithm;
    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 ecdhe-secp521r1 {
    base key-exchange-algorithm;
    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 ecdhe-x25519 {
    base key-exchange-algorithm;
    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 ecdhe-x448 {
    base key-exchange-algorithm;
    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 psk-ecdhe-secp256r1 {
    base key-exchange-algorithm;
    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 psk-ecdhe-secp384r1 {
    base key-exchange-algorithm;
    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 psk-ecdhe-secp521r1 {
    base key-exchange-algorithm;
    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 psk-ecdhe-x25519 {
    base key-exchange-algorithm;
    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 psk-ecdhe-x448 {
    base key-exchange-algorithm;
    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 diffie-hellman-group14-sha1 {
    base key-exchange-algorithm;
    description
      "Using DH group14 and SHA1 for key exchange";
    reference
      "RFC 4253: The Secure Shell (SSH) Transport Layer Protocol";
  }

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

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

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

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

  identity diffie-hellman-group18-sha512 {
    base key-exchange-algorithm;
    description
      "Using DH group18 and SHA512 for key exchange";
    reference
      "RFC 8268:
         More Modular Exponentiation (MODP) Diffie-Hellman (DH)
         Key Exchange (KEX) Groups for Secure Shell (SSH)";
  }

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

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

  identity rsaes-oaep {
    base key-exchange-algorithm;
    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 rsaes-pkcs1-v1_5 {
    base key-exchange-algorithm;
    description
      " 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;
    }
    description
      "This typedef enables importing modules to easily define an
       identityref 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 to the 'key-exchange-algorithm' base identity.";
  }

  /***************************************************/
  /*   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 public-key-grouping {
    description
      "A public key.
         
       The 'algorithm' and 'public-key' nodes are not
       mandatory because they MAY be defined in <operational>.
       Implementations SHOULD assert that these values are
       either configured or that they exist in <operational>.";
    leaf algorithm {
      nacm:default-deny-write;
      type asymmetric-key-algorithm-ref;
      must '../public-key';
      description
        "Identifies the key's algorithm.  More specifically,
         this leaf specifies how the 'public-key' binary leaf
         is encoded.";
      reference
        "RFC CCCC: Common YANG Data Types for Cryptography";
    }
    leaf public-key {
      nacm:default-deny-write;
      type binary;
      must '../algorithm';
      description
        "A binary that contains the value of the public key.  The
         interpretation of the content is defined by the key
         algorithm.  For example, a DSA key is an integer, an RSA
         key is represented as RSAPublicKey as defined in
         RFC 8017, and an Elliptic Curve Cryptography (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/public key pair.
         
       The 'algorithm', 'public-key', and 'private-key'  nodes are
       not mandatory because they MAY be defined in <operational>.
       Implementations SHOULD assert that these values are either
       configured or that they exist in <operational>.";
    uses public-key-grouping;
    leaf private-key {
      nacm:default-deny-all;
      type union {
        type binary;
        type enumeration {
          enum permanently-hidden {
            description
              "The private key is inaccessible due to being
               protected by the system (e.g., a cryptographic
               hardware module).

               How such keys are backed-up and restored, if
               at all, is implementation specific.
               
               Servers MUST fail any attempt by a client to
               configure this value directly.  This value is
               not set by clients, but rather is set by the
               'generate-hidden-key' and 'install-hidden-key'
               actions.";
          }
        }
      }
      must '../public-key';
      description
        "A binary that contains the value of the private key.  The
         interpretation of the content is defined by the key
         algorithm.  For example, a DSA key is an integer, an RSA
         key is represented as RSAPrivateKey as defined in
         RFC 8017, and an Elliptic Curve Cryptography (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.";
    } // private-key

    action generate-hidden-key {
      nacm:default-deny-all;
      description
        "Requests the device to generate a hidden key using the
         specified asymmetric key algorithm.  This action is
         used to request the system to generate a key that is
         'permanently-hidden', perhaps protected by a cryptographic
         hardware module.  The resulting asymmetric key values are
         considered operational state and hence present only in
         <operational> and bound to the lifetime of the parent
         'config true' node.  Subsequent invocations of this or
         the 'install-hidden-key' action are denied with error-tag
         'data-exists'.";
      input {
        leaf algorithm {
          type asymmetric-key-algorithm-ref;
          mandatory true;
          description
            "The algorithm to be used when generating the
             asymmetric key.";
          reference
            "RFC CCCC: Common YANG Data Types for Cryptography";
        }
      }
    } // generate-hidden-key

    action install-hidden-key {
      nacm:default-deny-all;
      description
        "Requests the device to load the specified values into
         a hidden key.  The resulting asymmetric key values are
         considered operational state and hence present only in
         <operational> and bound to the lifetime of the parent
         'config true' node.  Subsequent invocations of this
         or the 'generate-hidden-key' action are denied with
         error-tag 'data-exists'.";
      input {
        leaf algorithm {
          type asymmetric-key-algorithm-ref;
          mandatory true;
          description
            "The algorithm to be used when generating the
             asymmetric key.";
          reference
            "RFC CCCC: Common YANG Data Types for Cryptography";
        }
        leaf public-key {
          type binary;
          description
            "A binary that contains the value of the public key.
             The interpretation of the content is defined by the key
             algorithm.  For example, a DSA key is an integer, an
             RSA key is represented as RSAPublicKey as defined in
             RFC 8017, and an Elliptic Curve Cryptography (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.";
        }
        leaf private-key {
          type binary;
          description
            "A binary that contains the value of the private key.
             The interpretation of the content is defined by the key
             algorithm.  For example, a DSA key is an integer, an RSA
             key is represented as RSAPrivateKey as defined in
             RFC 8017, and an Elliptic Curve Cryptography (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.";
        }
      }
    } // install-hidden-key
  } // asymmetric-key-pair-grouping


  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.";
    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.";

    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;
          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.";
    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;
          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

5.2. Informative References

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>
    <private-key>base64encodedvalue==</private-key>
    <public-key>base64encodedvalue==</public-key>
    <certificates>
      <certificate>
        <name>ex-cert</name>
        <cert>base64encodedvalue==</cert>
      </certificate>
    </certificates>
  </key>
</keys>

A.2. The "generate-hidden-key" Action

The following example illustrates the "generate-hidden-key" 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>empty-key</name>
        <generate-hidden-key>
          <algorithm
           xmlns:ct="urn:ietf:params:xml:ns:yang:ietf-crypto-types">
              ct:rsa2048
          </algorithm>
        </generate-hidden-key>
      </key>
    </keys>
  </action>
</rpc>

RESPONSE

<rpc-reply message-id="101"
  xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
  <ok/>
</rpc-reply>

A.3. The "install-hidden-key" Action

The following example illustrates the "install-hidden-key" 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>empty-key</name>
        <install-hidden-key>
          <algorithm
           xmlns:ct="urn:ietf:params:xml:ns:yang:ietf-crypto-types">
              ct:rsa2048
          </algorithm>
          <public-key>base64encodedvalue==</public-key>
          <private-key>base64encodedvalue==</private-key>
        </install-hidden-key>
      </key>
    </keys>
  </action>
</rpc>

RESPONSE

<rpc-reply message-id="101"
  xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
  <ok/>
</rpc-reply>

A.4. 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.5. 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

• Removed groupings and notifications.
• Added typedefs for identityrefs.
• Added typedefs for other RFC 5280 structures.
• Added typedefs for other RFC 5652 structures.
• Added convenience typedefs for RFC 4253, RFC 5280, and RFC 5652.

B.2. 00 to 01

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

B.3. 01 to 02

• Removed unwanted "mandatory" and "must" statements.
• Added many new crypto algorithms (thanks Haiguang!)
• 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

• renamed base identity 'asymmetric-key-encryption-algorithm' to 'asymmetric-key-algorithm'.
• added new 'asymmetric-key-algorithm' identities for secp192r1, secp224r1, secp256r1, secp384r1, and secp521r1.
• 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.
• for all -cbc and -ctr identities, renamed base identity 'symmetric-key-encryption-algorithm' to 'encryption-algorithm'.
• 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.
• for all the 'signature-algorithm' based identities, renamed from 'rsa-*' to 'rsassa-*'.
• removed all of the "x509v3-" prefixed 'signature-algorithm' based identities.
• added 'key-exchange-algorithm' based identities for 'rsaes-oaep' and 'rsaes-pkcs1-v1_5'.
• renamed typedef 'symmetric-key-encryption-algorithm-ref' to 'symmetric-key-algorithm-ref'.
• renamed typedef 'asymmetric-key-encryption-algorithm-ref' to 'asymmetric-key-algorithm-ref'.
• added typedef 'encryption-and-mac-algorithm-ref'.
• Updated copyright date, boilerplate template, affiliation, and folding algorithm.

B.5. 03 to 04

• ran YANG module through formatter.

B.6. 04 to 05

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

B.7. 05 to 06

• Added NACM annotations.
• Updated Security Considerations section.
• Added 'asymmetric-key-pair-with-cert-grouping' grouping.
• Removed text from 'permanently-hidden' enum regarding such keys not being backed up or restored.
• Updated the boilerplate text in module-level "description" statement to match copyeditor convention.
• 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>.
• 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.
• 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.
• Added 'trust-anchor-certs-grouping' and 'end-entity-certs-grouping' (the plural form of existing groupings).
• 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.

Acknowledgements

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

Authors' Addresses