Common YANG Data Types for Cryptography
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:

• 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:

• 2019-06-20 --> 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 December 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
• 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-certificate-signing-request" Action
• A.3. 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
• B.8. 06 to 07
• B.9. 07 to 08
• B.10. 08 to 09
• 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 symmetric-key-grouping:
    +---- algorithm    encryption-algorithm-t
    +---- (key-type)
       +--:(key)
       |  +---- key?   binary
       +--:(hidden-key)
          +---- hidden-key?   empty
  grouping public-key-grouping:
    +---- algorithm     asymmetric-key-algorithm-t
    +---- public-key    binary
  grouping asymmetric-key-pair-grouping:
    +---- algorithm            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-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-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@2019-06-20.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 2019-06-20 {
    description
      "Initial version";
    reference
      "RFC XXXX: Common YANG Data Types for Cryptography";
  }

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

  typedef hash-algorithm-t {
    type union {
      type uint16;
      type enumeration {
        enum NONE {
          value 0;
          description
            "Hash algorithm is NULL.";
        }
        enum sha1 {
          value 1;
          status obsolete;
          description
            "The SHA1 algorithm.";
          reference
            "RFC 3174: US Secure Hash Algorithms 1 (SHA1).";
        }
        enum sha-224 {
          value 2;
          description
            "The SHA-224 algorithm.";
          reference
            "RFC 6234: US Secure Hash Algorithms.";
        }
        enum sha-256 {
          value 3;
          description
            "The SHA-256 algorithm.";
          reference
            "RFC 6234: US Secure Hash Algorithms.";
        }
        enum sha-384 {
          value 4;
          description
            "The SHA-384 algorithm.";
          reference
            "RFC 6234: US Secure Hash Algorithms.";
        }
        enum sha-512 {
          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   */
  /***********************************************/

  typedef asymmetric-key-algorithm-t {
    type union {
      type uint16;
      type enumeration {
        enum NONE {
          value 0;
          description
            "Asymetric key algorithm is NULL.";
        }
        enum rsa1024 {
          value 1;
          description
            "The RSA algorithm using a 1024-bit key.";
          reference
            "RFC 8017: PKCS #1: RSA Cryptography
             Specifications Version 2.2.";
        }
        enum rsa2048 {
          value 2;
          description
            "The RSA algorithm using a 2048-bit key.";
          reference
            "RFC 8017:
             PKCS #1: RSA Cryptography Specifications Version 2.2.";
        }
        enum rsa3072 {
          value 3;
          description
            "The RSA algorithm using a 3072-bit key.";
          reference
            "RFC 8017:
             PKCS #1: RSA Cryptography Specifications Version 2.2.";
        }
        enum rsa4096 {
          value 4;
          description
            "The RSA algorithm using a 4096-bit key.";
          reference
            "RFC 8017:
             PKCS #1: RSA Cryptography Specifications Version 2.2.";
        }
        enum rsa7680 {
          value 5;
          description
            "The RSA algorithm using a 7680-bit key.";
          reference
            "RFC 8017:
             PKCS #1: RSA Cryptography Specifications Version 2.2.";
        }
        enum rsa15360 {
          value 6;
          description
            "The RSA algorithm using a 15360-bit key.";
          reference
            "RFC 8017:
             PKCS #1: RSA Cryptography Specifications Version 2.2.";
        }
        enum secp192r1 {
          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.";
        }
        enum secp224r1 {
          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.";
        }
        enum secp256r1 {
          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.";
        }
        enum secp384r1 {
          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.";
        }
        enum secp521r1 {
          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   */
  /*************************************/

  typedef mac-algorithm-t {
    type union {
      type uint16;
      type enumeration {
        enum NONE {
          value 0;
          description
            "mac algorithm is NULL.";
        }
        enum hmac-sha1 {
          value 1;
          description
            "Generating MAC using SHA1 hash function";
          reference
            "RFC 3174: US Secure Hash Algorithm 1 (SHA1)";
        }
        enum hmac-sha1-96 {
          value 2;
          description
            "Generating MAC using SHA1 hash function";
          reference
            "RFC 2404: The Use of HMAC-SHA-1-96 within ESP and AH";
        }
        enum hmac-sha2-224 {
          value 3;
          description
            "Generating MAC using SHA2 hash function";
          reference
            "RFC 6234: US Secure Hash Algorithms
             (SHA and SHA-based HMAC and HKDF)";
        }
        enum hmac-sha2-256 {
          value 4;
          description
            "Generating MAC using SHA2 hash function";
          reference
            "RFC 6234: US Secure Hash Algorithms
             (SHA and SHA-based HMAC and HKDF)";
        }
        enum hmac-sha2-256-128 {
          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";
        }
        enum hmac-sha2-384 {
          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)";
        }
        enum hmac-sha2-384-192 {
          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";
        }
        enum hmac-sha2-512 {
          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)";
        }
        enum hmac-sha2-512-256 {
          value 9;
          description
            "Generating a 512 bits MAC using SHA2 hash function and
             truncate it to 256 bits";
          reference
            "RFC 4868: Using HMAC-SHA-256, HMAC-SHA-384,
             and HMAC-SHA-512 with IPsec";
        }
        enum aes-128-gmac {
          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.";
          reference
            "RFC 4543:
               The Use of Galois Message Authentication Code (GMAC)
               in IPsec ESP and AH";
        }
        enum aes-192-gmac {
          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.";
          reference
            "RFC 4543:
               The Use of Galois Message Authentication Code (GMAC)
               in IPsec ESP and AH";
        }
        enum aes-256-gmac {
          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.";
          reference
            "RFC 4543:
               The Use of Galois Message Authentication Code (GMAC)
               in IPsec ESP and AH";
        }
        enum aes-cmac-96 {
          value 13;
          description
            "Generating 96-bit MAC using Advanced Encryption
             Standard (AES) Cipher-based Message Authentication
             Code (CMAC)";
          reference
            "RFC 4494:
               The AES-CMAC Algorithm and its Use with IPsec";
        }
        enum aes-cmac-128 {
          value 14;
          description
            "Generating 128-bit MAC using Advanced Encryption
             Standard (AES) Cipher-based Message Authentication
             Code (CMAC)";
          reference
            "RFC 4494:
               The AES-CMAC 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   */
  /********************************************/

  typedef encryption-algorithm-t {
    type union {
      type uint16;
      type enumeration {
        enum NONE {
          value 0;
          description
            "Encryption algorithm is NULL.";
        }
        enum aes-128-cbc {
          value 1;
          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)";
        }
        enum aes-192-cbc {
          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)";
        }
        enum aes-256-cbc {
          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)";
        }
        enum aes-128-ctr {
          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)";
        }
        enum aes-192-ctr {
          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)";
        }
        enum aes-256-ctr {
          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   */
  /****************************************************/

  typedef encryption-and-mac-algorithm-t {
    type union {
      type uint16;
      type enumeration {
        enum NONE {
          value 0;
          description
            "Encryption and MAC algorithm is NULL.";
          reference
            "None";
        }
        enum aes-128-ccm {
          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)";
        }
        enum aes-192-ccm {
          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)";
        }
        enum aes-256-ccm {
          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)";
        }
        enum aes-128-gcm {
          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)";
        }
        enum aes-192-gcm {
          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)";
        }
        enum aes-256-gcm {
          value 6;
          description
            "Encrypt message with AES algorithm in GCM
             mode with a key length of 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)";
        }
        enum chacha20-poly1305 {
          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   */
  /******************************************/

  typedef signature-algorithm-t {
    type union {
      type uint16;
      type enumeration {
        enum NONE {
          value 0;
          description
            "Signature algorithm is NULL";
        }
        enum dsa-sha1 {
          value 1;
          description
            "The signature algorithm using DSA algorithm with SHA1
             hash algorithm";
          reference
            "RFC 4253:
               The Secure Shell (SSH) Transport Layer Protocol";
        }
        enum rsassa-pkcs1-sha1 {
          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";
        }
        enum rsassa-pkcs1-sha256 {
          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";
        }
        enum rsassa-pkcs1-sha384 {
          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";
        }
        enum rsassa-pkcs1-sha512 {
          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";
        }
        enum rsassa-pss-rsae-sha256 {
          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";
        }
        enum rsassa-pss-rsae-sha384 {
          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";
        }
        enum rsassa-pss-rsae-sha512 {
          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";
        }
        enum rsassa-pss-pss-sha256 {
          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 rsaEncryption OID";
          reference
            "RFC 8446:
               The Transport Layer Security (TLS) Protocol
               Version 1.3";
        }
        enum rsassa-pss-pss-sha384 {
          value 10;
          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";
        }
        enum rsassa-pss-pss-sha512 {
          value 11;
          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";
        }
        enum ecdsa-secp256r1-sha256 {
          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";
        }
        enum ecdsa-secp384r1-sha384 {
          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";
        }
        enum ecdsa-secp521r1-sha512 {
          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";
        }
        enum ed25519 {
          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)";
        }
        enum ed448 {
          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)";
        }
        enum eccsi {
          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   */
  /**********************************************/

  typedef key-exchange-algorithm-t {
    type union {
      type uint16;
      type enumeration {
        enum NONE {
          value 0;
          description
            "Key exchange algorithm is NULL.";
        }
        enum psk-only {
          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)";
        }
        enum dhe-ffdhe2048 {
          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)";
        }
        enum dhe-ffdhe3072 {
          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)";
        }
        enum dhe-ffdhe4096 {
          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)";
        }
        enum dhe-ffdhe6144 {
          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)";
        }
        enum dhe-ffdhe8192 {
          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)";
        }
        enum psk-dhe-ffdhe2048 {
          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";
        }
        enum psk-dhe-ffdhe3072 {
          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";
        }
        enum psk-dhe-ffdhe4096 {
          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";
        }
        enum psk-dhe-ffdhe6144 {
          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";
        }
        enum psk-dhe-ffdhe8192 {
          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";
        }
        enum ecdhe-secp256r1 {
          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";
        }
        enum ecdhe-secp384r1 {
          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";
        }
        enum ecdhe-secp521r1 {
          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";
        }
        enum ecdhe-x25519 {
          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";
        }
        enum ecdhe-x448 {
          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";
        }
        enum psk-ecdhe-secp256r1 {
          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";
        }
        enum psk-ecdhe-secp384r1 {
          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";
        }
        enum psk-ecdhe-secp521r1 {
          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";
        }
        enum psk-ecdhe-x25519 {
          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";
        }
        enum psk-ecdhe-x448 {
          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";
        }
        enum diffie-hellman-group14-sha1 {
          value 22;
          description
            "Using DH group14 and SHA1 for key exchange";
          reference
            "RFC 4253:
               The Secure Shell (SSH) Transport Layer Protocol";
        }
        enum diffie-hellman-group14-sha256 {
          value 23;
          description
            "Using DH group14 and SHA-256 for key exchange";
          reference
            "RFC 8268:
              More Modular Exponentiation (MODP) Diffie-Hellman (DH)
              Key Exchange (KEX) Groups for Secure Shell (SSH)";
        }
        enum diffie-hellman-group15-sha512 {
          value 24;
          description
            "Using DH group15 and SHA-512 for key exchange";
          reference
            "RFC 8268:
              More Modular Exponentiation (MODP) Diffie-Hellman (DH)
              Key Exchange (KEX) Groups for Secure Shell (SSH)";
        }
        enum diffie-hellman-group16-sha512 {
          value 25;
          description
            "Using DH group16 and SHA-512 for key exchange";
          reference
            "RFC 8268:
              More Modular Exponentiation (MODP) Diffie-Hellman (DH)
              Key Exchange (KEX) Groups for Secure Shell (SSH)";
        }
        enum diffie-hellman-group17-sha512 {
          value 26;
          description
            "Using DH group17 and SHA-512 for key exchange";
          reference
            "RFC 8268:
              More Modular Exponentiation (MODP) Diffie-Hellman (DH)
              Key Exchange (KEX) Groups for Secure Shell (SSH)";
        }
        enum diffie-hellman-group18-sha512 {
          value 27;
          description
            "Using DH group18 and SHA-512 for key exchange";
          reference
            "RFC 8268:
              More Modular Exponentiation (MODP) Diffie-Hellman (DH)
              Key Exchange (KEX) Groups for Secure Shell (SSH)";
        }
        enum ecdh-sha2-secp256r1 {
          value 28;
          description
            "Elliptic curve-based Diffie Hellman key exchange over
             curve ecp256r1 and using SHA2 for MAC generation";
          reference
            "RFC 6239:
               Suite B Cryptographic Suites for Secure Shell (SSH)";
        }
        enum ecdh-sha2-secp384r1 {
          value 29;
          description
            "Elliptic curve-based Diffie Hellman key exchange over
             curve ecp384r1 and using SHA2 for MAC generation";
          reference
            "RFC 6239:
               Suite B Cryptographic Suites for Secure Shell (SSH)";
        }
        enum rsaes-oaep {
          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.";
        }
        enum rsaes-pkcs1-v1_5 {
          value 31;
          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.";
        }
      }
    }
    default "0";
    description
      "The uint16 filed shall be set by individual protocol
       families according to the key exchange algorithm value
       assigned by IANA. The setting is optional and by default
       is 0.  The enumeration filed is set to the 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 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-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

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>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>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

• 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.

B.8. 06 to 07

• Added clarifications that implementations SHOULD assert that configured certificates contain the matching public key.
• Replaced the 'generate-hidden-key' and 'install-hidden-key' actions with special 'crypt-hash' -like input/output values.

B.9. 07 to 08

• Removed the 'generate-key and 'hidden-key' features.
• Added grouping symmetric-key-grouping
• 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

• 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, Balázs Kovács, Juergen Schoenwaelder, Eric Voit, and Liang Xia.

Authors' Addresses