NETCONF M. Jethanandani Internet-Draft VMware Intended status: Standards Track K. Watsen Expires: March 20, 2020 Watsen Networks September 17, 2019 An HTTPS-based Transport for Configured Subscriptions draft-ietf-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 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 March 20, 2020. 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 Jethanandani & Watsen Expires March 20, 2020 [Page 1] Internet-Draft HTTP Configured Subscription September 2019 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). Jethanandani & Watsen Expires March 20, 2020 [Page 2] Internet-Draft HTTP Configured Subscription September 2019 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. 2019-09-17 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 Jethanandani & Watsen Expires March 20, 2020 [Page 3] Internet-Draft HTTP Configured Subscription September 2019 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. file "ietf-https-notif@2019-09-17.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; Jethanandani & Watsen Expires March 20, 2020 [Page 4] Internet-Draft HTTP Configured Subscription September 2019 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: WG List: 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 "2019-09-17" { description "Initial Version."; reference "RFC XXXX, YANG Data Module for HTTPS Notifications."; } identity https { Jethanandani & Watsen Expires March 20, 2020 [Page 5] Internet-Draft HTTP Configured Subscription September 2019 base sn:transport; description "HTTPS transport for notifications."; } container receivers { list receiver { key "name"; leaf name { type string; description "A name that uniquely identifies this receiver."; } 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 Jethanandani & Watsen Expires March 20, 2020 [Page 6] Internet-Draft HTTP Configured Subscription September 2019 "Augment the subscriptions container to define the receiver."; } } 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 Jethanandani & Watsen Expires March 20, 2020 [Page 7] Internet-Draft HTTP Configured Subscription September 2019 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] foo 192.0.2.1 443 192.0.3.1 63001 explicitly-trusted-server-ca-certs explicitly-trusted-server-certs Jethanandani & Watsen Expires March 20, 2020 [Page 8] Internet-Draft HTTP Configured Subscription September 2019 6666 foo some-stream my-receiver foo explicitly-trusted-server-certs Specific server authentication certificates for explicitly trusted servers. These are needed for server certificates that are not signed by a pinned CA. Fred Flintstone base64encodedvalue== explicitly-trusted-server-ca-certs 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. ca.example.com base64encodedvalue== Jethanandani & Watsen Expires March 20, 2020 [Page 9] Internet-Draft HTTP Configured Subscription September 2019 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, . [RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688, DOI 10.17487/RFC3688, January 2004, . [RFC6020] Bjorklund, M., Ed., "YANG - A Data Modeling Language for the Network Configuration Protocol (NETCONF)", RFC 6020, DOI 10.17487/RFC6020, October 2010, . [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, . [RFC6242] Wasserman, M., "Using the NETCONF Protocol over Secure Shell (SSH)", RFC 6242, DOI 10.17487/RFC6242, June 2011, . [RFC7950] Bjorklund, M., Ed., "The YANG 1.1 Data Modeling Language", RFC 7950, DOI 10.17487/RFC7950, August 2016, . [RFC8040] Bierman, A., Bjorklund, M., and K. Watsen, "RESTCONF Protocol", RFC 8040, DOI 10.17487/RFC8040, January 2017, . [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, May 2017, . Jethanandani & Watsen Expires March 20, 2020 [Page 10] Internet-Draft HTTP Configured Subscription September 2019 [RFC8341] Bierman, A. and M. Bjorklund, "Network Configuration Access Control Model", STD 91, RFC 8341, DOI 10.17487/RFC8341, March 2018, . [RFC8446] Rescorla, E., "The Transport Layer Security (TLS) Protocol Version 1.3", RFC 8446, DOI 10.17487/RFC8446, August 2018, . Authors' Addresses Mahesh Jethanandani VMware Email: mjethanandani@gmail.com Kent Watsen Watsen Networks USA Email: kent+ietf@watsen.net Jethanandani & Watsen Expires March 20, 2020 [Page 11]