ietf-sztp-conveyed-info.yang

module ietf-sztp-conveyed-info {
  yang-version 1.1;
  namespace "urn:ietf:params:xml:ns:yang:ietf-sztp-conveyed-info";
  prefix sztp-info;

  import ietf-yang-types {
    prefix yang;
    reference "RFC 6991: Common YANG Data Types";
  }
  import ietf-inet-types {
    prefix inet;
    reference "RFC 6991: Common YANG Data Types";
  }
  import ietf-restconf {
    prefix rc;
    reference "RFC 8040: RESTCONF Protocol";
  }

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

  contact
    "WG Web:   http://tools.ietf.org/wg/netconf
     WG List:  <mailto:netconf@ietf.org>
     Author:   Kent Watsen <mailto:kwatsen@juniper.net>";

  description
   "This module defines the data model for the Conveyed
    Information artifact defined in RFC XXXX: Secure Zero Touch
    Provisioning (SZTP).

    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.

    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 (http://trustee.ietf.org/license-info)

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

  revision YYYY-MM-DD {
    description
      "Initial version";
    reference
      "RFC XXXX: Secure Zero Touch Provisioning (SZTP)";
  }

  // identities

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

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

  // typedefs

  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).";
  }

  // yang-data

  rc:yang-data "conveyed-information" {
    choice information-type {
      mandatory true;
      description
        "This choice statement ensures the response contains
         redirect-information or onboarding-information.";
      container redirect-information {
        description
          "Redirect information is described in Section 2.1 in
           RFC XXXX.  Its purpose is to redirect a device to 
           another bootstrap server.";
        reference
          "RFC XXXX: Secure Zero Touch Provisioning (SZTP)";
        list bootstrap-server {
          key "address";
          min-elements 1;
          description
            "A bootstrap server entry.";
          leaf address {
            type inet:host;
            mandatory true;
            description
             "The IP address or hostname of the bootstrap server the
              device should redirect to.";
          }
          leaf port {
            type inet:port-number;
            default "443";
            description
             "The port number the bootstrap server listens on.  If no
              port is specified, the IANA-assigned port for 'https'
              (443) is used.";
          }
          leaf trust-anchor {
            type cms;
            description
              "A CMS structure that MUST contain the chain of
               X.509 certificates needed to authenticate the TLS
               certificate presented by this bootstrap server.

               The CMS MUST only contain a single chain of
               certificates.  The bootstrap server 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 bootstrap
               server's TLS certificate, only one certificate
               is present.

               If needed by the device, this CMS structure MAY
               also contain suitably fresh 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.";
          }
        }
      }
      container onboarding-information {
        description
          "Onboarding information is described in Section 2.2 in
           RFC XXXX.  Its purpose is to provide the device everything
           it needs to bootstrap itself.";
        reference
          "RFC XXXX: Secure Zero Touch Provisioning (SZTP)";
        container boot-image {
          description
            "Specifies criteria for the boot image the device MUST 
             be running, as well as information enabling the device
             to install the required boot image.";
          leaf os-name {
            type string;
            description
              "The name of the operating system software the device
               MUST be running in order to not require a software
               image upgrade (ex. VendorOS).";
          }
          leaf os-version {
            type string;
            description
              "The version of the operating system software the
               device MUST be running in order to not require a
               software image upgrade (ex. 17.3R2.1).";
          }
          leaf-list download-uri {
            type inet:uri;
            ordered-by user;
            description
              "An ordered list of URIs to where the same boot image
               file may be obtained.  How the URI schemes (http, ftp,
               etc.) a device supports are known is vendor specific.
               If a secure scheme (e.g., https) is provided, a device
               MAY establish an untrusted connection to the remote
               server, by blindly accepting the server's end-entity
               certificate, to obtain the boot image.";
          }
          list image-verification {
            must '../download-uri' {
              description
                "Download URIs must be provided if an image is to
                 be verified.";
            }
            key hash-algorithm;
            description
              "A list of hash values that a device can use to verify
               boot image files with.";
            leaf hash-algorithm {
              type identityref {
                base "hash-algorithm";
              }
              description
                "Identifies the hash algorithm used.";
            }
            leaf hash-value {
              type yang:hex-string;
              mandatory true;
              description
                "The hex-encoded value of the specified hash
                 algorithm over the contents of the boot image
                 file.";
            }
          }
        }
        leaf configuration-handling {
          type enumeration {
            enum "merge" {
              description
                "Merge configuration into the running datastore.";
            }
            enum "replace" {
              description
                "Replace the existing running datastore with the
                 passed configuration.";
            }
          }
          must '../configuration';
          description
            "This enumeration indicates how the server should process
             the provided configuration.";
        }
        leaf pre-configuration-script {
          type script;
          description
            "A script that, when present, is executed before the
             configuration has been processed.";
        }
        leaf configuration {
          type binary;
          must '../configuration-handling';
          description
            "Any configuration known to the device.  The use of
             the 'binary' type enables e.g., XML-content to be
             embedded into a JSON document.  The exact encoding
             of the content, as with the scripts, is vendor
             specific.";
        }
        leaf post-configuration-script {
          type script;
          description
            "A script that, when present, is executed after the 
             configuration has been processed.";
        }
      }
    }
  }

  typedef script {
    type binary;
    description
      "A device specific script that enables the execution of 
       commands to perform actions not possible thru configuration
       alone.  

       No attempt is made to standardize the contents, running
       context, or programming language of the script, other than
       that it can indicate if any warnings or errors occurred and
       can emit output.  The contents of the script are considered
       specific to the vendor, product line, and/or model of the
       device.
        
       If the script execution indicates that an warning occurred,
       then the device MUST assume that the script had a soft error
       that the script believes will not affect manageability.

       If the script execution indicates that an error occurred,
       the device MUST assume the script had a hard error that the
       script believes will affect manageability.  In this case, 
       the script is required to gracefully exit, removing any
       state that might hinder the device's ability to continue
       the bootstrapping sequence (e.g., process onboarding
       information obtained from another bootstrap server).";
  }
}