NETCONF                                                  M. Jethanandani
Internet-Draft                                                    VMware
Intended status: Standards Track                               K. Watsen
Expires: December 28, 2019                               Watsen Networks
                                                           June 26, 2019


         An HTTPS-based Transport for Configured Subscriptions
                  draft-mahesh-netconf-https-notif-00

Abstract

   This document defines a YANG data module for configuring HTTPS based
   configured subscription, as defined I-D.ietf-netconf-subscribed-
   notifications.  The use of HTTPS maximizes transport-level
   interoperability, while allowing for encoding selection from text,
   e.g.  XML or JSON, to binary.

Status of This Memo

   This Internet-Draft is submitted in full conformance with the
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   Internet-Drafts are working documents of the Internet Engineering
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   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 28, 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




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   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
     1.1.  Note to RFC Editor  . . . . . . . . . . . . . . . . . . .   3
     1.2.  Abbreviations . . . . . . . . . . . . . . . . . . . . . .   3
     1.3.  Terminology . . . . . . . . . . . . . . . . . . . . . . .   3
       1.3.1.  Subscribed Notifications  . . . . . . . . . . . . . .   3
   2.  YANG module . . . . . . . . . . . . . . . . . . . . . . . . .   3
     2.1.  Overview  . . . . . . . . . . . . . . . . . . . . . . . .   3
     2.2.  YANG module . . . . . . . . . . . . . . . . . . . . . . .   4
   3.  Security Considerations . . . . . . . . . . . . . . . . . . .   7
   4.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   7
     4.1.  URI Registration  . . . . . . . . . . . . . . . . . . . .   7
     4.2.  YANG Module Name Registration . . . . . . . . . . . . . .   8
   5.  Examples  . . . . . . . . . . . . . . . . . . . . . . . . . .   8
     5.1.  HTTPS Configured Subscription . . . . . . . . . . . . . .   8
   6.  Contributors  . . . . . . . . . . . . . . . . . . . . . . . .  10
   7.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .  10
   8.  Normative references  . . . . . . . . . . . . . . . . . . . .  10
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  11

1.  Introduction

   Subscribed Notifications [I-D.ietf-netconf-subscribed-notifications]
   defines a YANG data module for configuring subscribed notifications.
   It even defines a subscriptions container that contains a list of
   receivers.  But it defers the configuration and management of those
   receivers to other documents.  This document defines a YANG [RFC7950]
   data module for configuring and managing HTTPS based receivers for
   the notifications.  Such a configured receiver can be a third party
   collector, collecting events on behalf of receivers that want to co-
   relate events from different publishers.  Configured subscriptions
   enable a server, acting as a publisher of notifications, to
   proactively push notifications to external receivers without the
   receivers needing to first connect to the server, as is the case with
   dynamic subscriptions.

   This document describes how to enable the transmission of YANG
   modeled notifications, in the configured encoding (i.e., XML, JSON)
   over HTTPS.  The use of HTTPS maximizes transport-level
   interoperability, while the encoding selection pivots between
   implementation simplicity (XML, JSON) and throughput (text versus
   binary).





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1.1.  Note to RFC Editor

   This document uses several placeholder values throughout the
   document.  Please replace them as follows and remove this section
   before publication.

   RFC XXXX, where XXXX is the number assigned to this document at the
   time of publication.

   2019-06-26 with the actual date of the publication of this document.

1.2.  Abbreviations

                +---------+-------------------------------+
                | Acronym | Expansion                     |
                +---------+-------------------------------+
                | HTTP    | Hyper Text Transport Protocol |
                |         |                               |
                | TCP     | Transmission Control Protocol |
                |         |                               |
                | TLS     | Transport Layer Security      |
                +---------+-------------------------------+

1.3.  Terminology

   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 [RFC2119] RFC8174 [RFC8174] when, and only when, they
   appear in all capitals, as shown here.

1.3.1.  Subscribed Notifications

   The following terms are defined in Subscribed Notifications
   [I-D.ietf-netconf-subscribed-notifications].

   o  Subscribed Notifications

2.  YANG module

2.1.  Overview

   The YANG module is a definition of a set of receivers that are
   interested in the notifications published by the publisher.  The
   module contains the TCP, TLS and HTTPS parameters that are needed to
   communicate with the receiver.  The module augments the Subscribed
   Notifications [I-D.ietf-netconf-subscribed-notifications] receiver




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   container to create a reference to a receiver defined by the YANG
   module.

   An abridged tree diagram representing the module is shown below.

   module: ietf-https-notif
     +--rw receivers
        +--rw receiver* [name]
           +--rw name           string
           +--rw tcp-params
           |  +--rw remote-address    inet:host
           |  +--rw remote-port?      inet:port-number
           |  +--rw local-address?    inet:ip-address
           |  +--rw local-port?       inet:port-number
           |  +--rw keepalives!
           |        ...
           +--rw tls-params
           |  +--rw client-identity
           |  |     ...
           |  +--rw server-authentication
           |  |     ...
           |  +--rw hello-params {tls-client-hello-params-config}?
           |  |     ...
           |  +--rw keepalives! {tls-client-keepalives}?
           |        ...
           +--rw http-params
              +--rw protocol-version?   enumeration
              +--rw client-identity
              |     ...
              +--rw proxy-server! {proxy-connect}?
                    ...

     augment /sn:subscriptions/sn:subscription/sn:receivers/sn:receiver:
       +--rw receiver-ref?   -> /receivers/receiver/name


2.2.  YANG module

   The YANG module is shown below.

<CODE BEGINS> file "ietf-https-notif@2019-06-26.yang"
module ietf-https-notif {
  yang-version 1.1;
  namespace "urn:ietf:params:xml:ns:yang:ietf-https-notif";
  prefix "hsn";

  import ietf-subscribed-notifications {
    prefix sn;



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    reference
      "I-D.ietf-netconf-subscribed-notifications";
  }

  import ietf-tcp-client {
    prefix tcpc;
  }

  import ietf-tls-client {
    prefix tlsc;
  }

  import ietf-http-client {
    prefix httpc;
  }

  organization
    "IETF NETCONF Working Group";

  contact
    "WG Web:   <http://tools.ietf.org/wg/netconf>
     WG List:  <netconf@ietf.org>

     Authors: Mahesh Jethanandani (mjethanandani at gmail dot com)
              Kent Watsen (kent plus ietf at watsen dot net)";
  description
    "YANG module for configuring HTTPS base configuration.

     Copyright (c) 2018 IETF Trust and the persons identified as
     the document authors.  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 "2019-06-26" {
    description
      "Initial Version.";
    reference
      "RFC XXXX, YANG Data Module for HTTPS Notifications.";
  }

  identity https {



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    base sn:transport;
    description
      "HTTPS transport for notifications.";
  }

  container receivers {
    list receiver {
      key "name";

      leaf name {
        type string;
        description
          "";
      }

      container tcp-params {
        uses tcpc:tcp-client-grouping;
        description
          "TCP client parameters.";
      }

      container tls-params {
        uses tlsc:tls-client-grouping;
        description
          "TLS client parameters.";
      }

      container http-params {
        uses httpc:http-client-grouping;
        description
          "HTTP client parameters.";
      }
      description
        "All receivers interested in this notification.";
    }
    description
      "HTTPS based notifications.";
  }

  augment "/sn:subscriptions/sn:subscription/sn:receivers/sn:receiver" {
    leaf receiver-ref {
      type leafref {
        path "/receivers/receiver/name";
      }
      description
        "Reference to a receiver.";
    }
    description



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      "Augment the subscriptions container to define the receiver.";
  }
}
<CODE ENDS>


3.  Security Considerations

   The YANG module specified in this document defines a schema for data
   that is designed to be accessed via network management protocols such
   as NETCONF [RFC6241] or RESTCONF [RFC8040].  The lowest NETCONF layer
   is the secure transport layer, and the mandatory-to-implement secure
   transport is Secure Shell (SSH) [RFC6242].  The lowest RESTCONF layer
   is HTTPS, and the mandatory-to-implement secure transport is TLS
   [RFC8446].  The NETCONF Access Control Model (NACM) [RFC8341]
   provides the means to restrict access for particular NETCONF or
   RESTCONF users to a preconfigured subset of all available NETCONF or
   RESTCONF protocol operations and content.

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

   Some of the readable data nodes in this YANG module may be considered
   sensitive or vulnerable in some network environments.  It is thus
   important to control read access (e.g., via get, get-config, or
   notification) to these data nodes.  These are the subtrees and data
   nodes and their sensitivity/vulnerability:

   Some of the RPC 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:

4.  IANA Considerations

   This document registers one URI and one YANG module.

4.1.  URI Registration

   in the IETF XML registry [RFC3688] [RFC3688].  Following the format
   in RFC 3688, the following registration is requested to be made:

   URI: urn:ietf:params:xml:ns:yang:ietf-http-notif



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   Registrant Contact: The IESG.  XML: N/A, the requested URI is an XML
   namespace.

4.2.  YANG Module Name Registration

   This document registers three YANG module in the YANG Module Names
   registry YANG [RFC6020].

   name: ietf-https-notif
   namespace: urn:ietf:params:xml:ns:yang:ietf-https-notif
   prefix: hn
   reference: RFC XXXX

5.  Examples

   This section tries to show some examples in how the model can be
   used.

5.1.  HTTPS Configured Subscription

   This example shows how a HTTPS client can be configured to send
   notifications to a receiver at address 192.0.2.1, port 443 with
   server certificates, and the corresponding trust store that is used
   to authenticate a connection.

[note: '\' line wrapping for formatting only]

<?xml version="1.0" encoding="UTF-8"?>
<config xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
  <receivers
      xmlns="urn:ietf:params:xml:ns:yang:ietf-https-notif">
      <receiver>
        <name>foo</name>
        <tcp-params>
          <remote-address>192.0.2.1</remote-address>
          <remote-port>443</remote-port>
          <local-address>192.0.3.1</local-address>
          <local-port>63001</local-port>
        </tcp-params>
        <tls-params>
          <server-authentication>
            <ca-certs>explicitly-trusted-server-ca-certs</ca-certs>
            <server-certs>explicitly-trusted-server-certs</server-ce\
rts>
          </server-authentication>
        </tls-params>
      </receiver>
  </receivers>



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  <subscriptions
      xmlns="urn:ietf:params:xml:ns:yang:ietf-subscribed-notificatio\
ns">
    <subscription>
      <id>6666</id>
      <stream-subtree-filter>foo</stream-subtree-filter>
      <stream>some-stream</stream>
        <receivers>
          <receiver>
            <name>my-receiver</name>
            <receiver-ref
                xmlns="urn:ietf:params:xml:ns:yang:ietf-https-notif">foo</receiver\
-ref>
          </receiver>
        </receivers>
      </subscription>
  </subscriptions>

  <truststore xmlns="urn:ietf:params:xml:ns:yang:ietf-truststore">
    <certificates>
       <name>explicitly-trusted-server-certs</name>
       <description>
         Specific server authentication certificates for explicitly
         trusted servers.  These are needed for server certificates
         that are not signed by a pinned CA.
       </description>
       <certificate>
         <name>Fred Flintstone</name>
         <cert>base64encodedvalue==</cert>
       </certificate>
     </certificates>
     <certificates>
       <name>explicitly-trusted-server-ca-certs</name>
       <description>
         Trust anchors (i.e. CA certs) that are used to authenticate\

         server connections.  Servers are authenticated if their
         certificate has a chain of trust to one of these CA
         certificates.
       </description>
       <certificate>
         <name>ca.example.com</name>
         <cert>base64encodedvalue==</cert>
       </certificate>
     </certificates>
  </truststore>
</config>




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6.  Contributors

7.  Acknowledgements

8.  Normative references

   [I-D.ietf-netconf-subscribed-notifications]
              Voit, E., Clemm, A., Prieto, A., Nilsen-Nygaard, E., and
              A. Tripathy, "Subscription to YANG Event Notifications",
              draft-ietf-netconf-subscribed-notifications-26 (work in
              progress), May 2019.

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119,
              DOI 10.17487/RFC2119, March 1997,
              <https://www.rfc-editor.org/info/rfc2119>.

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

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

   [RFC6241]  Enns, R., Ed., Bjorklund, M., Ed., Schoenwaelder, J., Ed.,
              and A. Bierman, Ed., "Network Configuration Protocol
              (NETCONF)", RFC 6241, DOI 10.17487/RFC6241, June 2011,
              <https://www.rfc-editor.org/info/rfc6241>.

   [RFC6242]  Wasserman, M., "Using the NETCONF Protocol over Secure
              Shell (SSH)", RFC 6242, DOI 10.17487/RFC6242, June 2011,
              <https://www.rfc-editor.org/info/rfc6242>.

   [RFC7950]  Bjorklund, M., Ed., "The YANG 1.1 Data Modeling Language",
              RFC 7950, DOI 10.17487/RFC7950, August 2016,
              <https://www.rfc-editor.org/info/rfc7950>.

   [RFC8040]  Bierman, A., Bjorklund, M., and K. Watsen, "RESTCONF
              Protocol", RFC 8040, DOI 10.17487/RFC8040, January 2017,
              <https://www.rfc-editor.org/info/rfc8040>.

   [RFC8174]  Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
              2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
              May 2017, <https://www.rfc-editor.org/info/rfc8174>.





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   [RFC8341]  Bierman, A. and M. Bjorklund, "Network Configuration
              Access Control Model", STD 91, RFC 8341,
              DOI 10.17487/RFC8341, March 2018,
              <https://www.rfc-editor.org/info/rfc8341>.

   [RFC8446]  Rescorla, E., "The Transport Layer Security (TLS) Protocol
              Version 1.3", RFC 8446, DOI 10.17487/RFC8446, August 2018,
              <https://www.rfc-editor.org/info/rfc8446>.

Authors' Addresses

   Mahesh Jethanandani
   VMware

   Email: mjethanandani@gmail.com


   Kent Watsen
   Watsen Networks
   USA

   Email: kent+ietf@watsen.net





























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