NETCONF Working Group K. Watsen Internet-Draft Watsen Networks Intended status: Standards Track March 9, 2019 Expires: September 10, 2019 RESTCONF Client and Server Models draft-ietf-netconf-restconf-client-server-10 Abstract This document defines two YANG modules, one module to configure a RESTCONF client and the other module to configure a RESTCONF server. Both modules support the TLS transport protocol with both standard RESTCONF and RESTCONF Call Home connections. 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. This document contains references to other drafts in progress, both in the Normative References section, as well as in body text throughout. Please update the following references to reflect their final RFC assignments: o I-D.ietf-netconf-keystore o I-D.ietf-netconf-tcp-client-server o I-D.ietf-netconf-tls-client-server o I-D.ietf-netconf-http-client-server Artwork in this document contains shorthand references to drafts in progress. Please apply the following replacements: o "XXXX" --> the assigned RFC value for this draft o "AAAA" --> the assigned RFC value for I-D.ietf-netconf-tcp-client- server o "CCCC" --> the assigned RFC value for I-D.ietf-netconf-tls-client- server Watsen Expires September 10, 2019 [Page 1] Internet-Draft RESTCONF Client and Server Models March 2019 o "BBBB" --> the assigned RFC value for I-D.ietf-netconf-http- client-server Artwork in this document contains placeholder values for the date of publication of this draft. Please apply the following replacement: o "2019-03-09" --> the publication date of this draft The following Appendix section is to be removed prior to publication: o Appendix A. 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 September 10, 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. Watsen Expires September 10, 2019 [Page 2] Internet-Draft RESTCONF Client and Server Models March 2019 Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 1.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 3 2. The RESTCONF Client Model . . . . . . . . . . . . . . . . . . 4 2.1. Tree Diagram . . . . . . . . . . . . . . . . . . . . . . 4 2.2. Example Usage . . . . . . . . . . . . . . . . . . . . . . 9 2.3. YANG Module . . . . . . . . . . . . . . . . . . . . . . . 12 3. The RESTCONF Server Model . . . . . . . . . . . . . . . . . . 20 3.1. Tree Diagram . . . . . . . . . . . . . . . . . . . . . . 21 3.2. Example Usage . . . . . . . . . . . . . . . . . . . . . . 24 3.3. YANG Module . . . . . . . . . . . . . . . . . . . . . . . 27 4. Security Considerations . . . . . . . . . . . . . . . . . . . 36 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 37 5.1. The IETF XML Registry . . . . . . . . . . . . . . . . . . 37 5.2. The YANG Module Names Registry . . . . . . . . . . . . . 38 6. References . . . . . . . . . . . . . . . . . . . . . . . . . 38 6.1. Normative References . . . . . . . . . . . . . . . . . . 38 6.2. Informative References . . . . . . . . . . . . . . . . . 39 Appendix A. Change Log . . . . . . . . . . . . . . . . . . . . . 41 A.1. 00 to 01 . . . . . . . . . . . . . . . . . . . . . . . . 41 A.2. 01 to 02 . . . . . . . . . . . . . . . . . . . . . . . . 41 A.3. 02 to 03 . . . . . . . . . . . . . . . . . . . . . . . . 41 A.4. 03 to 04 . . . . . . . . . . . . . . . . . . . . . . . . 41 A.5. 04 to 05 . . . . . . . . . . . . . . . . . . . . . . . . 41 A.6. 05 to 06 . . . . . . . . . . . . . . . . . . . . . . . . 42 A.7. 06 to 07 . . . . . . . . . . . . . . . . . . . . . . . . 42 A.8. 07 to 08 . . . . . . . . . . . . . . . . . . . . . . . . 42 A.9. 08 to 09 . . . . . . . . . . . . . . . . . . . . . . . . 42 A.10. 09 to 10 . . . . . . . . . . . . . . . . . . . . . . . . 42 Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . 43 Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 43 1. Introduction This document defines two YANG [RFC7950] modules, one module to configure a RESTCONF client and the other module to configure a RESTCONF server [RFC8040]. Both modules support the TLS [RFC8446] transport protocol with both standard RESTCONF and RESTCONF Call Home connections [RFC8071]. 1.1. 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] [RFC8174] when, and only when, they appear in all capitals, as shown here. Watsen Expires September 10, 2019 [Page 3] Internet-Draft RESTCONF Client and Server Models March 2019 2. The RESTCONF Client Model The RESTCONF client model presented in this section supports both clients initiating connections to servers, as well as clients listening for connections from servers calling home. This model, like that presented in [I-D.ietf-netconf-netconf-client-server], is designed to support any number of possible transports. RESTCONF only supports the TLS transport currently, thus this model only supports the TLS transport. All private keys and trusted certificates are held in the keystore model defined in [I-D.ietf-netconf-keystore]. YANG feature statements are used to enable implementations to advertise which parts of the model the RESTCONF client supports. 2.1. Tree Diagram The following tree diagram [RFC8340] provides an overview of the data model for the "ietf-restconf-client" module. Just the container is displayed below, but there is also a reusable grouping called "restconf-client-grouping" that the container is using. ========== NOTE: '\\' line wrapping per BCP XX (RFC XXXX) =========== module: ietf-restconf-client +--rw restconf-client +--rw initiate! {initiate}? | +--rw restconf-server* [name] | +--rw name string | +--rw endpoints | +--rw endpoint* [name] | +--rw name string | +--rw (transport) | | +--:(https) {https-initiate}? | | +--rw https | | +--rw remote-address inet:host | | +--rw remote-port? | | | inet:port-number | | +--rw local-address? inet:ip-addr\ \ess | | +--rw local-port? | | | inet:port-number | | +--rw tcp-keepalives {tcp-client-keepalive\ \s}? | | | +--rw idle-time? uint16 | | | +--rw max-probes? uint16 Watsen Expires September 10, 2019 [Page 4] Internet-Draft RESTCONF Client and Server Models March 2019 | | | +--rw probe-interval? uint16 | | +--rw tls-client-identity | | | +--rw (auth-type) | | | +--:(certificate) | | | +--rw certificate | | | +--rw (local-or-keystore) | | | +--:(local) | | | | {local-keys-suppor\ \ted}? | | | | +--rw local-definition | | | | +--rw algorithm? | | | | | asymmetric-ke\ \y-algorithm-ref | | | | +--rw public-key? | | | | | binary | | | | +--rw private-key? | | | | | union | | | | +---x generate-hidden\ \-key | | | | | +---w input | | | | | +---w algorithm | | | | | asymmet\ \ric-key-algorithm-ref | | | | +---x install-hidden-\ \key | | | | | +---w input | | | | | +---w algorithm | | | | | | asymmet\ \ric-key-algorithm-ref | | | | | +---w public-ke\ \y? | | | | | | binary | | | | | +---w private-k\ \ey? | | | | | binary | | | | +--rw cert? | | | | | end-entity-ce\ \rt-cms | | | | +---n certificate-exp\ \iration | | | | +-- expiration-date | | | | yang:date-\ \and-time | | | +--:(keystore) | | | {keystore-supporte\ \d}? | | | +--rw keystore-reference? | | | ks:asymmetric-ke\ Watsen Expires September 10, 2019 [Page 5] Internet-Draft RESTCONF Client and Server Models March 2019 \y-certificate-ref | | +--rw tls-server-auth | | | +--rw pinned-ca-certs? | | | | ta:pinned-certificates-ref | | | | {ta:x509-certificates}? | | | +--rw pinned-server-certs? | | | ta:pinned-certificates-ref | | | {ta:x509-certificates}? | | +--rw tls-hello-params | | | {tls-client-hello-params-config}? | | | +--rw tls-versions | | | | +--rw tls-version* identityref | | | +--rw cipher-suites | | | +--rw cipher-suite* identityref | | +--rw tls-keepalives {tls-client-keepalive\ \s}? | | | +--rw max-wait? uint16 | | | +--rw max-attempts? uint8 | | +--rw http-client-identity | | | +--rw (auth-type)? | | | +--:(basic) | | | | +--rw basic | | | | +--rw user-id? string | | | | +--rw password? string | | | +--:(bearer) | | | | +--rw bearer | | | | +--rw token? string | | | +--:(digest) | | | | +--rw digest | | | | +--rw username? string | | | | +--rw password? string | | | +--:(hoba) | | | | +--rw hoba | | | +--:(mutual) | | | | +--rw mutual | | | +--:(negotiate) | | | | +--rw negotiate | | | +--:(oauth) | | | | +--rw oauth | | | +--:(scram-sha-1) | | | | +--rw scram-sha-1 | | | +--:(scram-sha-256) | | | | +--rw scram-sha-256 | | | +--:(vapid) | | | +--rw vapid | | +--rw http-keepalives | | {http-client-keepalives}? | | +--rw max-wait? uint16 Watsen Expires September 10, 2019 [Page 6] Internet-Draft RESTCONF Client and Server Models March 2019 | | +--rw max-attempts? uint8 | +--rw connection-type | | +--rw (connection-type) | | +--:(persistent-connection) | | | +--rw persistent! | | +--:(periodic-connection) | | +--rw periodic! | | +--rw period? uint16 | | +--rw anchor-time? yang:date-and-time | | +--rw idle-timeout? uint16 | +--rw reconnect-strategy | +--rw start-with? enumeration | +--rw max-attempts? uint8 +--rw listen! {listen}? +--rw idle-timeout? uint16 +--rw endpoint* [name] +--rw name string +--rw (transport) +--:(https) {https-listen}? +--rw https +--rw local-address inet:ip-address +--rw local-port? inet:port-number +--rw tcp-keepalives {tcp-server-keepalives}? | +--rw idle-time? uint16 | +--rw max-probes? uint16 | +--rw probe-interval? uint16 +--rw tls-client-identity | +--rw (auth-type) | +--:(certificate) | +--rw certificate | +--rw (local-or-keystore) | +--:(local) {local-keys-supported\ \}? | | +--rw local-definition | | +--rw algorithm? | | | asymmetric-key-algo\ \rithm-ref | | +--rw public-key? | | | binary | | +--rw private-key? | | | union | | +---x generate-hidden-key | | | +---w input | | | +---w algorithm | | | asymmetric-ke\ \y-algorithm-ref | | +---x install-hidden-key | | | +---w input Watsen Expires September 10, 2019 [Page 7] Internet-Draft RESTCONF Client and Server Models March 2019 | | | +---w algorithm | | | | asymmetric-ke\ \y-algorithm-ref | | | +---w public-key? | | | | binary | | | +---w private-key? | | | binary | | +--rw cert? | | | end-entity-cert-cms | | +---n certificate-expiration | | +-- expiration-date | | yang:date-and-ti\ \me | +--:(keystore) {keystore-supporte\ \d}? | +--rw keystore-reference? | ks:asymmetric-key-cert\ \ificate-ref +--rw tls-server-auth | +--rw pinned-ca-certs? | | ta:pinned-certificates-ref | | {ta:x509-certificates}? | +--rw pinned-server-certs? | ta:pinned-certificates-ref | {ta:x509-certificates}? +--rw tls-hello-params | {tls-client-hello-params-config}? | +--rw tls-versions | | +--rw tls-version* identityref | +--rw cipher-suites | +--rw cipher-suite* identityref +--rw tls-keepalives {tls-client-keepalives}? | +--rw max-wait? uint16 | +--rw max-attempts? uint8 +--rw http-client-identity | +--rw (auth-type)? | +--:(basic) | | +--rw basic | | +--rw user-id? string | | +--rw password? string | +--:(bearer) | | +--rw bearer | | +--rw token? string | +--:(digest) | | +--rw digest | | +--rw username? string | | +--rw password? string | +--:(hoba) Watsen Expires September 10, 2019 [Page 8] Internet-Draft RESTCONF Client and Server Models March 2019 | | +--rw hoba | +--:(mutual) | | +--rw mutual | +--:(negotiate) | | +--rw negotiate | +--:(oauth) | | +--rw oauth | +--:(scram-sha-1) | | +--rw scram-sha-1 | +--:(scram-sha-256) | | +--rw scram-sha-256 | +--:(vapid) | +--rw vapid +--rw http-keepalives {http-client-keepalives}? +--rw max-wait? uint16 +--rw max-attempts? uint8 2.2. Example Usage The following example illustrates configuring a RESTCONF client to initiate connections, as well as listening for call-home connections. This example is consistent with the examples presented in Section 3.2 of [I-D.ietf-netconf-keystore]. ========== NOTE: '\\' line wrapping per BCP XX (RFC XXXX) =========== corp-fw1 corp-fw1.example.com corp-fw1.example.com 15 3 30 ct:rsa2048 base64encodedvalue== base64encodedvalue== base64encodedvalue== explicitly-trusted-server-ca-certs explicitly-trusted-server-certs 30 3 bob secret 30 3 corp-fw2.example.com corp-fw2.example.com 15 3 30 ct:rsa2048 base64encodedvalue== base64encodedvalue== Watsen Expires September 10, 2019 [Page 10] Internet-Draft RESTCONF Client and Server Models March 2019 base64encodedvalue== explicitly-trusted-server-ca-certs explicitly-trusted-server-certs 30 3 bob secret 30 3 Intranet-facing listener 11.22.33.44 ct:rsa2048 base64encodedvalue== base64encodedvalue== base64encodedvalue== Watsen Expires September 10, 2019 [Page 11] Internet-Draft RESTCONF Client and Server Models March 2019 explicitly-trusted-server-ca-certs explicitly-trusted-server-certs 2.3. YANG Module This YANG module has normative references to [RFC6991], [RFC8040], and [RFC8071], [I-D.kwatsen-netconf-tcp-client-server], [I-D.ietf-netconf-tls-client-server], and [I-D.kwatsen-netconf-http-client-server]. file "ietf-restconf-client@2019-03-09.yang" module ietf-restconf-client { yang-version 1.1; namespace "urn:ietf:params:xml:ns:yang:ietf-restconf-client"; prefix rcc; import ietf-yang-types { prefix yang; reference "RFC 6991: Common YANG Data Types"; } import ietf-tcp-client { prefix tcpc; reference "RFC AAAA: YANG Groupings for TCP Clients and TCP Servers"; } import ietf-tcp-server { prefix tcps; reference "RFC AAAA: YANG Groupings for TCP Clients and TCP Servers"; } import ietf-tls-client { prefix tlsc; reference "RFC BBBB: YANG Groupings for TLS Clients and TLS Servers"; Watsen Expires September 10, 2019 [Page 12] Internet-Draft RESTCONF Client and Server Models March 2019 } import ietf-http-client { prefix httpc; reference "RFC CCCC: YANG Groupings for HTTP Clients and HTTP Servers"; } organization "IETF NETCONF (Network Configuration) Working Group"; contact "WG Web: WG List: Author: Kent Watsen Author: Gary Wu "; description "This module contains a collection of YANG definitions for configuring RESTCONF clients. 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. 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 2019-03-09 { description "Initial version"; reference "RFC XXXX: RESTCONF Client and Server Models"; } Watsen Expires September 10, 2019 [Page 13] Internet-Draft RESTCONF Client and Server Models March 2019 // Features feature initiate { description "The 'initiate' feature indicates that the RESTCONF client supports initiating RESTCONF connections to RESTCONF servers using at least one transport (e.g., HTTPS, etc.)."; } feature https-initiate { if-feature "initiate"; description "The 'https-initiate' feature indicates that the RESTCONF client supports initiating HTTPS connections to RESTCONF servers. This feature exists as HTTPS might not be a mandatory to implement transport in the future."; reference "RFC 8040: RESTCONF Protocol"; } feature listen { description "The 'listen' feature indicates that the RESTCONF client supports opening a port to accept RESTCONF server call home connections using at least one transport (e.g., HTTPS, etc.)."; } feature https-listen { if-feature "listen"; description "The 'https-listen' feature indicates that the RESTCONF client supports opening a port to listen for incoming RESTCONF server call-home connections. This feature exists as not all RESTCONF clients may support RESTCONF call home."; reference "RFC 8071: NETCONF Call Home and RESTCONF Call Home"; } // Groupings grouping restconf-client-grouping { description "Top-level grouping for RESTCONF client configuration."; container initiate { if-feature "initiate"; presence "Enables client to initiate TCP connections"; description Watsen Expires September 10, 2019 [Page 14] Internet-Draft RESTCONF Client and Server Models March 2019 "Configures client initiating underlying TCP connections."; list restconf-server { key "name"; min-elements 1; description "List of RESTCONF servers the RESTCONF client is to initiate connections to in parallel."; leaf name { type string; description "An arbitrary name for the RESTCONF server."; } container endpoints { description "Container for the list of endpoints."; list endpoint { key "name"; min-elements 1; ordered-by user; description "A non-empty user-ordered list of endpoints for this RESTCONF client to try to connect to in sequence. Defining more than one enables high-availability."; leaf name { type string; description "An arbitrary name for this endpoint."; } choice transport { mandatory true; description "Selects between available transports. This is a 'choice' statement so as to support additional transport options to be augmented in."; case https { if-feature "https-initiate"; container https { description "Specifies HTTPS-specific transport configuration."; uses tcpc:tcp-client-grouping { refine "remote-port" { default "443"; description "The RESTCONF client will attempt to connect to the IANA-assigned well-known port value for 'https' (443) if no value is specified."; Watsen Expires September 10, 2019 [Page 15] Internet-Draft RESTCONF Client and Server Models March 2019 } } uses tlsc:tls-client-grouping { refine "tls-client-identity/auth-type" { mandatory true; description "RESTCONF clients MUST pass some authentication credentials."; } } uses httpc:http-client-grouping; } } // https } // transport container connection-type { description "Indicates the RESTCONF client's preference for how the RESTCONF connection is maintained."; choice connection-type { mandatory true; description "Selects between available connection types."; case persistent-connection { container persistent { presence "Indicates that a persistent connection is to be maintained."; description "Maintain a persistent connection to the RESTCONF server. If the connection goes down, immediately start trying to reconnect to it, using the reconnection strategy. This connection type minimizes any RESTCONF server to RESTCONF client data-transfer delay, albeit at the expense of holding resources longer."; } } case periodic-connection { container periodic { presence "Indicates that a periodic connection is to be maintained."; description "Periodically connect to the RESTCONF server. The RESTCONF server should close the underlying TCP connection upon completing planned activities. This connection type increases resource utilization, albeit with increased delay in Watsen Expires September 10, 2019 [Page 16] Internet-Draft RESTCONF Client and Server Models March 2019 RESTCONF server to RESTCONF client interactions."; leaf period { type uint16; units "minutes"; default "60"; description "Duration of time between periodic connections."; } leaf anchor-time { type yang:date-and-time { // constrained to minute-level granularity pattern '\d{4}-\d{2}-\d{2}T\d{2}:\d{2}' + '(Z|[\+\-]\d{2}:\d{2})'; } description "Designates a timestamp before or after which a series of periodic connections are determined. The periodic connections occur at a whole multiple interval from the anchor time. For example, for an anchor time is 15 minutes past midnight and a period interval of 24 hours, then a periodic connection will occur 15 minutes past midnight everyday."; } leaf idle-timeout { type uint16; units "seconds"; default 120; // two minutes description "Specifies the maximum number of seconds that the underlying TCP session may remain idle. A TCP session will be dropped if it is idle for an interval longer than this number of seconds If set to zero, then the RESTCONF client will never drop a session because it is idle."; } } } // periodic-connection } // connection-type } // connection-type container reconnect-strategy { description "The reconnection strategy directs how a RESTCONF client reconnects to a RESTCONF server, after discovering its connection to the server has Watsen Expires September 10, 2019 [Page 17] Internet-Draft RESTCONF Client and Server Models March 2019 dropped, even if due to a reboot. The RESTCONF client starts with the specified endpoint and tries to connect to it max-attempts times before trying the next endpoint in the list (round robin)."; leaf start-with { type enumeration { enum first-listed { description "Indicates that reconnections should start with the first endpoint listed."; } enum last-connected { description "Indicates that reconnections should start with the endpoint last connected to. If no previous connection has ever been established, then the first endpoint configured is used. RESTCONF clients SHOULD be able to remember the last endpoint connected to across reboots."; } enum random-selection { description "Indicates that reconnections should start with a random endpoint."; } } default "first-listed"; description "Specifies which of the RESTCONF server's endpoints the RESTCONF client should start with when trying to connect to the RESTCONF server."; } leaf max-attempts { type uint8 { range "1..max"; } default "3"; description "Specifies the number times the RESTCONF client tries to connect to a specific endpoint before moving on to the next endpoint in the list (round robin)."; } } // reconnect-strategy } // endpoint Watsen Expires September 10, 2019 [Page 18] Internet-Draft RESTCONF Client and Server Models March 2019 } // endpoints } // restconf-server } // initiate container listen { if-feature "listen"; presence "Enables client to accept call-home connections"; description "Configures client accepting call-home TCP connections."; leaf idle-timeout { type uint16; units "seconds"; default 3600; // one hour description "Specifies the maximum number of seconds that an underlying TCP session may remain idle. A TCP session will be dropped if it is idle for an interval longer than this number of seconds. If set to zero, then the server will never drop a session because it is idle. Sessions that have a notification subscription active are never dropped."; } list endpoint { key "name"; min-elements 1; description "List of endpoints to listen for RESTCONF connections."; leaf name { type string; description "An arbitrary name for the RESTCONF listen endpoint."; } choice transport { mandatory true; description "Selects between available transports. This is a 'choice' statement so as to support additional transport options to be augmented in."; case https { if-feature "https-listen"; container https { description "HTTPS-specific listening configuration for inbound connections."; uses tcps:tcp-server-grouping { refine "local-port" { default "4336"; description Watsen Expires September 10, 2019 [Page 19] Internet-Draft RESTCONF Client and Server Models March 2019 "The RESTCONF client will listen on the IANA- assigned well-known port for 'restconf-ch-tls' (4336) if no value is specified."; } } uses tlsc:tls-client-grouping { refine "tls-client-identity/auth-type" { mandatory true; description "RESTCONF clients MUST pass some authentication credentials."; } } uses httpc:http-client-grouping; } } // case https } // transport } // endpoint } // listen } // restconf-client // Protocol accessible node, for servers that implement this // module. container restconf-client { uses restconf-client-grouping; description "Top-level container for RESTCONF client configuration."; } } 3. The RESTCONF Server Model The RESTCONF server model presented in this section supports servers both listening for connections as well as initiating call-home connections. All private keys and trusted certificates are held in the keystore model defined in [I-D.ietf-netconf-keystore]. YANG feature statements are used to enable implementations to advertise which parts of the model the RESTCONF server supports. Watsen Expires September 10, 2019 [Page 20] Internet-Draft RESTCONF Client and Server Models March 2019 3.1. Tree Diagram The following tree diagram [RFC8340] provides an overview of the data model for the "ietf-restconf-server" module. Just the container is displayed below, but there is also a reusable grouping called "restconf-server-grouping" that the container is using. ========== NOTE: '\\' line wrapping per BCP XX (RFC XXXX) =========== module: ietf-restconf-server +--rw restconf-server +--rw listen! {listen}? | +--rw endpoint* [name] | +--rw name string | +--rw (transport) | +--:(https) {https-listen}? | +--rw https | +--rw local-address inet:ip-address | +--rw local-port? inet:port-number | +--rw tcp-keepalives {tcp-server-keepalives}? | | +--rw idle-time? uint16 | | +--rw max-probes? uint16 | | +--rw probe-interval? uint16 | +--rw tls-server-identity | | +--rw (local-or-keystore) | | +--:(local) {local-keys-supported}? | | | +--rw local-definition | | | +--rw algorithm? | | | | asymmetric-key-algorithm-ref | | | +--rw public-key? bina\ \ry | | | +--rw private-key? union | | | +---x generate-hidden-key | | | | +---w input | | | | +---w algorithm | | | | asymmetric-key-algorit\ \hm-ref | | | +---x install-hidden-key | | | | +---w input | | | | +---w algorithm | | | | | asymmetric-key-algorit\ \hm-ref | | | | +---w public-key? binary | | | | +---w private-key? binary | | | +--rw cert? | | | | end-entity-cert-cms | | | +---n certificate-expiration | | | +-- expiration-date Watsen Expires September 10, 2019 [Page 21] Internet-Draft RESTCONF Client and Server Models March 2019 | | | yang:date-and-time | | +--:(keystore) {keystore-supported}? | | +--rw keystore-reference? | | ks:asymmetric-key-certificate-r\ \ef | +--rw tls-client-auth | | +--rw pinned-ca-certs? | | | ta:pinned-certificates-ref | | | {ta:x509-certificates}? | | +--rw pinned-client-certs? | | | ta:pinned-certificates-ref | | | {ta:x509-certificates}? | | +--rw cert-maps | | +--rw cert-to-name* [id] | | +--rw id uint32 | | +--rw fingerprint | | | x509c2n:tls-fingerprint | | +--rw map-type identityref | | +--rw name string | +--rw tls-hello-params | | {tls-server-hello-params-config}? | | +--rw tls-versions | | | +--rw tls-version* identityref | | +--rw cipher-suites | | +--rw cipher-suite* identityref | +--rw tls-keepalives {tls-server-keepalives}? | | +--rw max-wait? uint16 | | +--rw max-attempts? uint8 | +--rw http-keepalives {http-server-keepalives}? | +--rw max-wait? uint16 | +--rw max-attempts? uint8 +--rw call-home! {call-home}? +--rw restconf-client* [name] +--rw name string +--rw endpoints | +--rw endpoint* [name] | +--rw name string | +--rw (transport) | +--:(https) {https-call-home}? | +--rw https | +--rw remote-address inet:host | +--rw remote-port? inet:port-num\ \ber | +--rw local-address? inet:ip-addre\ \ss | +--rw local-port? inet:port-num\ \ber | +--rw tcp-keepalives {tcp-client-keepalive\ Watsen Expires September 10, 2019 [Page 22] Internet-Draft RESTCONF Client and Server Models March 2019 \s}? | | +--rw idle-time? uint16 | | +--rw max-probes? uint16 | | +--rw probe-interval? uint16 | +--rw tls-server-identity | | +--rw (local-or-keystore) | | +--:(local) {local-keys-supported}? | | | +--rw local-definition | | | +--rw algorithm? | | | | asymmetric-key-algorit\ \hm-ref | | | +--rw public-key? | | | | binary | | | +--rw private-key? | | | | union | | | +---x generate-hidden-key | | | | +---w input | | | | +---w algorithm | | | | asymmetric-key-a\ \lgorithm-ref | | | +---x install-hidden-key | | | | +---w input | | | | +---w algorithm | | | | | asymmetric-key-a\ \lgorithm-ref | | | | +---w public-key? bin\ \ary | | | | +---w private-key? bin\ \ary | | | +--rw cert? | | | | end-entity-cert-cms | | | +---n certificate-expiration | | | +-- expiration-date | | | yang:date-and-time | | +--:(keystore) {keystore-supported}? | | +--rw keystore-reference? | | ks:asymmetric-key-certifi\ \cate-ref | +--rw tls-client-auth | | +--rw pinned-ca-certs? | | | ta:pinned-certificates-ref | | | {ta:x509-certificates}? | | +--rw pinned-client-certs? | | | ta:pinned-certificates-ref | | | {ta:x509-certificates}? | | +--rw cert-maps | | +--rw cert-to-name* [id] | | +--rw id uint32 Watsen Expires September 10, 2019 [Page 23] Internet-Draft RESTCONF Client and Server Models March 2019 | | +--rw fingerprint | | | x509c2n:tls-fingerprint | | +--rw map-type identityref | | +--rw name string | +--rw tls-hello-params | | {tls-server-hello-params-config}? | | +--rw tls-versions | | | +--rw tls-version* identityref | | +--rw cipher-suites | | +--rw cipher-suite* identityref | +--rw tls-keepalives {tls-server-keepalive\ \s}? | | +--rw max-wait? uint16 | | +--rw max-attempts? uint8 | +--rw http-keepalives | {http-server-keepalives}? | +--rw max-wait? uint16 | +--rw max-attempts? uint8 +--rw connection-type | +--rw (connection-type) | +--:(persistent-connection) | | +--rw persistent! | +--:(periodic-connection) | +--rw periodic! | +--rw period? uint16 | +--rw anchor-time? yang:date-and-time | +--rw idle-timeout? uint16 +--rw reconnect-strategy +--rw start-with? enumeration +--rw max-attempts? uint8 3.2. Example Usage The following example illustrates configuring a RESTCONF server to listen for RESTCONF client connections, as well as configuring call- home to one RESTCONF client. This example is consistent with the examples presented in Section 3.2 of [I-D.ietf-netconf-keystore]. ========== NOTE: '\\' line wrapping per BCP XX (RFC XXXX) =========== Watsen Expires September 10, 2019 [Page 24] Internet-Draft RESTCONF Client and Server Models March 2019 netconf/tls 11.22.33.44 ct:rsa2048 base64encodedvalue== base64encodedvalue== base64encodedvalue== explicitly-trusted-client-ca-certs explicitly-trusted-client-certs 1 11:0A:05:11:00 x509c2n:san-any 2 B3:4F:A1:8C:54 x509c2n:specified scooby-doo config-manager east-data-center east.example.com ct:rsa2048 base64encodedvalue== base64encodedvalue== base64encodedvalue== explicitly-trusted-client-ca-certs explicitly-trusted-client-certs 1 11:0A:05:11:00 x509c2n:san-any 2 B3:4F:A1:8C:54 x509c2n:specified scooby-doo west-data-center west.example.com 15 3 30 ct:rsa2048 base64encodedvalue== base64encodedvalue== base64encodedvalue== explicitly-trusted-client-ca-certs Watsen Expires September 10, 2019 [Page 26] Internet-Draft RESTCONF Client and Server Models March 2019 explicitly-trusted-client-certs 1 11:0A:05:11:00 x509c2n:san-any 2 B3:4F:A1:8C:54 x509c2n:specified scooby-doo 30 3 300 60 last-connected 3 3.3. YANG Module This YANG module has normative references to [RFC6991], [RFC7407], [RFC8040], [RFC8071], [I-D.kwatsen-netconf-tcp-client-server], [I-D.ietf-netconf-tls-client-server], and [I-D.kwatsen-netconf-http-client-server]. file "ietf-restconf-server@2019-03-09.yang" module ietf-restconf-server { yang-version 1.1; Watsen Expires September 10, 2019 [Page 27] Internet-Draft RESTCONF Client and Server Models March 2019 namespace "urn:ietf:params:xml:ns:yang:ietf-restconf-server"; prefix rcs; import ietf-yang-types { prefix yang; reference "RFC 6991: Common YANG Data Types"; } import ietf-x509-cert-to-name { prefix x509c2n; reference "RFC 7407: A YANG Data Model for SNMP Configuration"; } import ietf-tcp-client { prefix tcpc; reference "RFC AAAA: YANG Groupings for TCP Clients and TCP Servers"; } import ietf-tcp-server { prefix tcps; reference "RFC AAAA: YANG Groupings for TCP Clients and TCP Servers"; } import ietf-tls-server { prefix tlss; reference "RFC BBBB: YANG Groupings for TLS Clients and TLS Servers"; } import ietf-http-server { prefix https; reference "RFC CCCC: YANG Groupings for HTTP Clients and HTTP Servers"; } organization "IETF NETCONF (Network Configuration) Working Group"; contact "WG Web: WG List: Author: Kent Watsen Author: Gary Wu Author: Juergen Schoenwaelder Watsen Expires September 10, 2019 [Page 28] Internet-Draft RESTCONF Client and Server Models March 2019 "; description "This module contains a collection of YANG definitions for configuring RESTCONF servers. 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. 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 2019-03-09 { description "Initial version"; reference "RFC XXXX: RESTCONF Client and Server Models"; } // Features feature listen { description "The 'listen' feature indicates that the RESTCONF server supports opening a port to accept RESTCONF client connections using at least one transport (e.g., HTTPS, etc.)."; } feature https-listen { if-feature "listen"; description "The 'https-listen' feature indicates that the RESTCONF server supports opening a port to listen for incoming RESTCONF client connections. This feature exists as HTTPS might not Watsen Expires September 10, 2019 [Page 29] Internet-Draft RESTCONF Client and Server Models March 2019 be a mandatory to implement transport in the future."; reference "RFC 8040: RESTCONF Protocol"; } feature call-home { description "The 'call-home' feature indicates that the RESTCONF server supports initiating RESTCONF call home connections to RESTCONF clients using at least one transport (e.g., HTTPS, etc.)."; reference "RFC 8071: NETCONF Call Home and RESTCONF Call Home"; } feature https-call-home { if-feature "call-home"; description "The 'https-call-home' feature indicates that the RESTCONF server supports initiating connections to RESTCONF clients. This feature exists as not all RESTCONF servers may support RESTCONF call home."; reference "RFC 8071: NETCONF Call Home and RESTCONF Call Home"; } // Groupings grouping restconf-server-grouping { description "Top-level grouping for RESTCONF server configuration."; container listen { if-feature "listen"; presence "Enables server to listen for TCP connections"; description "Configures listen behavior"; list endpoint { key "name"; min-elements 1; description "List of endpoints to listen for RESTCONF connections."; leaf name { type string; description "An arbitrary name for the RESTCONF listen endpoint."; } choice transport { mandatory true; description Watsen Expires September 10, 2019 [Page 30] Internet-Draft RESTCONF Client and Server Models March 2019 "Selects between available transports. This is a 'choice' statement so as to support additional transport options to be augmented in."; case https { if-feature "https-listen"; container https { description "HTTPS-specific listening configuration for inbound connections."; uses tcps:tcp-server-grouping { refine "local-port" { default "443"; description "The RESTCONF server will listen on the IANA- assigned well-known port value for 'https' (443) if no value is specified."; } } uses tlss:tls-server-grouping { refine "tls-client-auth" { must 'pinned-ca-certs or pinned-client-certs'; description "RESTCONF servers MUST be able to validate clients."; } augment "tls-client-auth" { description "Augments in the cert-to-name structure, so the RESTCONF server can map TLS-layer client certificates to RESTCONF usernames."; container cert-maps { uses x509c2n:cert-to-name; description "The cert-maps container is used by a TLS- based RESTCONF server to map the RESTCONF client's presented X.509 certificate to a RESTCONF username. If no matching and valid cert-to-name list entry can be found, then the RESTCONF server MUST close the connection, and MUST NOT accept RESTCONF messages over it."; reference "RFC 7407: A YANG Data Model for SNMP Configuration."; } } } uses https:http-server-grouping; Watsen Expires September 10, 2019 [Page 31] Internet-Draft RESTCONF Client and Server Models March 2019 } // https container } // tls case } // transport } // endpoint } // listen container call-home { if-feature "call-home"; presence "Enables server to initiate TCP connections"; description "Configures call-home behavior"; list restconf-client { key "name"; min-elements 1; description "List of RESTCONF clients the RESTCONF server is to initiate call-home connections to in parallel."; leaf name { type string; description "An arbitrary name for the remote RESTCONF client."; } container endpoints { description "Container for the list of endpoints."; list endpoint { key "name"; min-elements 1; ordered-by user; description "User-ordered list of endpoints for this RESTCONF client. Defining more than one enables high- availability."; leaf name { type string; description "An arbitrary name for this endpoint."; } choice transport { mandatory true; description "Selects between available transports. This is a 'choice' statement so as to support additional transport options to be augmented in."; case https { if-feature "https-call-home"; container https { description "Specifies HTTPS-specific call-home transport Watsen Expires September 10, 2019 [Page 32] Internet-Draft RESTCONF Client and Server Models March 2019 configuration."; uses tcpc:tcp-client-grouping { refine "remote-port" { default "4336"; description "The RESTCONF server will attempt to connect to the IANA-assigned well-known port for 'restconf-ch-tls' (4336) if no value is specified."; } } uses tlss:tls-server-grouping { refine "tls-client-auth" { must 'pinned-ca-certs or pinned-client-certs'; description "RESTCONF servers MUST be able to validate clients."; } augment "tls-client-auth" { description "Augments in the cert-to-name structure, so the RESTCONF server can map TLS-layer client certificates to RESTCONF usernames."; container cert-maps { uses x509c2n:cert-to-name; description "The cert-maps container is used by a TLS-based RESTCONF server to map the RESTCONF client's presented X.509 certificate to a RESTCONF username. If no matching and valid cert-to-name list entry can be found, then the RESTCONF server MUST close the connection, and MUST NOT accept RESTCONF messages over it."; reference "RFC 7407: A YANG Data Model for SNMP Configuration."; } } } uses https:http-server-grouping; } } } // transport } // endpoint } // endpoints container connection-type { Watsen Expires September 10, 2019 [Page 33] Internet-Draft RESTCONF Client and Server Models March 2019 description "Indicates the RESTCONF server's preference for how the RESTCONF connection is maintained."; choice connection-type { mandatory true; description "Selects between available connection types."; case persistent-connection { container persistent { presence "Indicates that a persistent connection is to be maintained."; description "Maintain a persistent connection to the RESTCONF client. If the connection goes down, immediately start trying to reconnect to it, using the reconnection strategy. This connection type minimizes any RESTCONF client to RESTCONF server data-transfer delay, albeit at the expense of holding resources longer."; } } case periodic-connection { container periodic { presence "Indicates that a periodic connection is to be maintained."; description "Periodically connect to the RESTCONF client. The RESTCONF client should close the underlying TCP connection upon completing planned activities. This connection type increases resource utilization, albeit with increased delay in RESTCONF client to RESTCONF client interactions."; leaf period { type uint16; units "minutes"; default "60"; description "Duration of time between periodic connections."; } leaf anchor-time { type yang:date-and-time { // constrained to minute-level granularity pattern '\d{4}-\d{2}-\d{2}T\d{2}:\d{2}' + '(Z|[\+\-]\d{2}:\d{2})'; } Watsen Expires September 10, 2019 [Page 34] Internet-Draft RESTCONF Client and Server Models March 2019 description "Designates a timestamp before or after which a series of periodic connections are determined. The periodic connections occur at a whole multiple interval from the anchor time. For example, for an anchor time is 15 minutes past midnight and a period interval of 24 hours, then a periodic connection will occur 15 minutes past midnight everyday."; } leaf idle-timeout { type uint16; units "seconds"; default 120; // two minutes description "Specifies the maximum number of seconds that the underlying TCP session may remain idle. A TCP session will be dropped if it is idle for an interval longer than this number of seconds. If set to zero, then the server will never drop a session because it is idle."; } } } } } container reconnect-strategy { description "The reconnection strategy directs how a RESTCONF server reconnects to a RESTCONF client after discovering its connection to the client has dropped, even if due to a reboot. The RESTCONF server starts with the specified endpoint and tries to connect to it max-attempts times before trying the next endpoint in the list (round robin)."; leaf start-with { type enumeration { enum first-listed { description "Indicates that reconnections should start with the first endpoint listed."; } enum last-connected { description "Indicates that reconnections should start with the endpoint last connected to. If no previous connection has ever been established, then the first endpoint configured is used. RESTCONF Watsen Expires September 10, 2019 [Page 35] Internet-Draft RESTCONF Client and Server Models March 2019 servers SHOULD be able to remember the last endpoint connected to across reboots."; } enum random-selection { description "Indicates that reconnections should start with a random endpoint."; } } default "first-listed"; description "Specifies which of the RESTCONF client's endpoints the RESTCONF server should start with when trying to connect to the RESTCONF client."; } leaf max-attempts { type uint8 { range "1..max"; } default "3"; description "Specifies the number times the RESTCONF server tries to connect to a specific endpoint before moving on to the next endpoint in the list (round robin)."; } } } // restconf-client } // call-home } // restconf-server-grouping // Protocol accessible node, for servers that implement this // module. container restconf-server { uses restconf-server-grouping; description "Top-level container for RESTCONF server configuration."; } } 4. Security Considerations The YANG module defined in this document uses a grouping defined in [I-D.ietf-netconf-tls-client-server]. Please see the Security Considerations section in that document for concerns related that grouping. Watsen Expires September 10, 2019 [Page 36] Internet-Draft RESTCONF Client and Server Models March 2019 The YANG module defined in this document is 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. 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: /: The entire data trees defined by the modules defined in this draft are sensitive to write operations. For instance, the addition or removal of references to keys, certificates, trusted anchors, etc., can dramatically alter the implemented security policy. However, no NACM annotations are applied as the data SHOULD be editable by users other than a designated 'recovery session'. 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: NONE 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: NONE 5. IANA Considerations 5.1. The IETF XML Registry This document registers two URIs in the "ns" subregistry of the IETF XML Registry [RFC3688]. Following the format in [RFC3688], the following registrations are requested: Watsen Expires September 10, 2019 [Page 37] Internet-Draft RESTCONF Client and Server Models March 2019 URI: urn:ietf:params:xml:ns:yang:ietf-restconf-client Registrant Contact: The NETCONF WG of the IETF. XML: N/A, the requested URI is an XML namespace. URI: urn:ietf:params:xml:ns:yang:ietf-restconf-server Registrant Contact: The NETCONF WG of the IETF. XML: N/A, the requested URI is an XML namespace. 5.2. The YANG Module Names Registry This document registers two YANG modules in the YANG Module Names registry [RFC6020]. Following the format in [RFC6020], the the following registrations are requested: name: ietf-restconf-client namespace: urn:ietf:params:xml:ns:yang:ietf-restconf-client prefix: ncc reference: RFC XXXX name: ietf-restconf-server namespace: urn:ietf:params:xml:ns:yang:ietf-restconf-server prefix: ncs reference: RFC XXXX 6. References 6.1. Normative References [I-D.ietf-netconf-keystore] Watsen, K., "YANG Data Model for a Centralized Keystore Mechanism", draft-ietf-netconf-keystore-08 (work in progress), March 2019. [I-D.ietf-netconf-tls-client-server] Watsen, K., Wu, G., and L. Xia, "YANG Groupings for TLS Clients and TLS Servers", draft-ietf-netconf-tls-client- server-08 (work in progress), October 2018. [I-D.kwatsen-netconf-http-client-server] Watsen, K., "YANG Groupings for HTTP Clients and HTTP Servers", draft-kwatsen-netconf-http-client-server-00 (work in progress), March 2019. [I-D.kwatsen-netconf-tcp-client-server] Watsen, K., "YANG Groupings for TCP Clients and TCP Servers", draft-kwatsen-netconf-tcp-client-server-00 (work in progress), March 2019. Watsen Expires September 10, 2019 [Page 38] Internet-Draft RESTCONF Client and Server Models March 2019 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997, . [RFC6020] Bjorklund, M., Ed., "YANG - A Data Modeling Language for the Network Configuration Protocol (NETCONF)", RFC 6020, DOI 10.17487/RFC6020, October 2010, . [RFC6991] Schoenwaelder, J., Ed., "Common YANG Data Types", RFC 6991, DOI 10.17487/RFC6991, July 2013, . [RFC7407] Bjorklund, M. and J. Schoenwaelder, "A YANG Data Model for SNMP Configuration", RFC 7407, DOI 10.17487/RFC7407, December 2014, . [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, . [RFC8071] Watsen, K., "NETCONF Call Home and RESTCONF Call Home", RFC 8071, DOI 10.17487/RFC8071, February 2017, . [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, May 2017, . 6.2. Informative References [I-D.ietf-netconf-netconf-client-server] Watsen, K., "NETCONF Client and Server Models", draft- ietf-netconf-netconf-client-server-08 (work in progress), October 2018. [RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688, DOI 10.17487/RFC3688, January 2004, . Watsen Expires September 10, 2019 [Page 39] Internet-Draft RESTCONF Client and Server Models March 2019 [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, . [RFC8340] Bjorklund, M. and L. Berger, Ed., "YANG Tree Diagrams", BCP 215, RFC 8340, DOI 10.17487/RFC8340, March 2018, . [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, . Watsen Expires September 10, 2019 [Page 40] Internet-Draft RESTCONF Client and Server Models March 2019 Appendix A. Change Log A.1. 00 to 01 o Renamed "keychain" to "keystore". A.2. 01 to 02 o Filled in previously missing 'ietf-restconf-client' module. o Updated the ietf-restconf-server module to accomodate new grouping 'ietf-tls-server-grouping'. A.3. 02 to 03 o Refined use of tls-client-grouping to add a must statement indicating that the TLS client must specify a client-certificate. o Changed restconf-client??? to be a grouping (not a container). A.4. 03 to 04 o Added RFC 8174 to Requirements Language Section. o Replaced refine statement in ietf-restconf-client to add a mandatory true. o Added refine statement in ietf-restconf-server to add a must statement. o Now there are containers and groupings, for both the client and server models. o Now tree diagrams reference ietf-netmod-yang-tree-diagrams o Updated examples to inline key and certificates (no longer a leafref to keystore) A.5. 04 to 05 o Now tree diagrams reference ietf-netmod-yang-tree-diagrams o Updated examples to inline key and certificates (no longer a leafref to keystore) Watsen Expires September 10, 2019 [Page 41] Internet-Draft RESTCONF Client and Server Models March 2019 A.6. 05 to 06 o Fixed change log missing section issue. o Updated examples to match latest updates to the crypto-types, trust-anchors, and keystore drafts. o Reduced line length of the YANG modules to fit within 69 columns. A.7. 06 to 07 o removed "idle-timeout" from "persistent" connection config. o Added "random-selection" for reconnection-strategy's "starts-with" enum. o Replaced "connection-type" choice default (persistent) with "mandatory true". o Reduced the periodic-connection's "idle-timeout" from 5 to 2 minutes. o Replaced reconnect-timeout with period/anchor-time combo. A.8. 07 to 08 o Modified examples to be compatible with new crypto-types algs A.9. 08 to 09 o Corrected use of "mandatory true" for "address" leafs. o Updated examples to reflect update to groupings defined in the keystore draft. o Updated to use groupings defined in new TCP and HTTP drafts. o Updated copyright date, boilerplate template, affiliation, and folding algorithm. A.10. 09 to 10 o Reformatted YANG modules. Watsen Expires September 10, 2019 [Page 42] Internet-Draft RESTCONF Client and Server Models March 2019 Acknowledgements The authors would like to thank for following for lively discussions on list and in the halls (ordered by last name): Andy Bierman, Martin Bjorklund, Benoit Claise, Ramkumar Dhanapal, Mehmet Ersue, Balazs Kovacs, David Lamparter, Alan Luchuk, Ladislav Lhotka, Radek Krejci, Tom Petch, Juergen Schoenwaelder, Phil Shafer, Sean Turner, and Bert Wijnen. Author's Address Kent Watsen Watsen Networks EMail: kent+ietf@watsen.net Watsen Expires September 10, 2019 [Page 43]