--- 1/draft-ietf-netconf-server-model-05.txt 2015-02-02 12:14:53.590547205 -0800 +++ 2/draft-ietf-netconf-server-model-06.txt 2015-02-02 12:14:53.674549272 -0800 @@ -1,19 +1,19 @@ NETCONF Working Group K. Watsen Internet-Draft Juniper Networks Intended status: Standards Track J. Schoenwaelder -Expires: June 14, 2015 Jacobs University Bremen - December 11, 2014 +Expires: August 6, 2015 Jacobs University Bremen + February 2, 2015 NETCONF Server and RESTCONF Server Configuration Models - draft-ietf-netconf-server-model-05 + draft-ietf-netconf-server-model-06 Abstract This draft defines a NETCONF server configuration data model and a RESTCONF server configuration data model. These data models enable configuration of the NETCONF and RESTCONF services themselves, including which transports are supported, what ports the servers listens on, whether call-home is supported, and associated parameters. @@ -29,50 +29,47 @@ in the Normative References section, as well as in body text throughout. Please update the following references to reflect their final RFC assignments: o draft-ietf-netconf-rfc5539bis o draft-ietf-netconf-restconf o draft-ietf-netconf-call-home - o draft-ietf-netmod-snmp-cfg - Artwork in this document contains shorthand references to drafts in progress. Please apply the following replacements: o "VVVV" --> the assigned RFC value for this draft o "WWWW" --> the assigned RFC value for draft-ietf-netconf- rfc5539bis o "XXXX" --> the assigned RFC value for draft-ietf-netconf-restconf - o "YYYY" --> the assigned RFC value for draft-ietf-netconf-call-home - o "ZZZZ" --> the assigned RFC value for draft-ietf-netmod-snmp-cfg + o "ZZZZ" --> the assigned RFC value for draft-thomson-httpbis-cant Artwork in this document contains placeholder values for ports pending IANA assignment from "draft-ietf-netconf-call-home". Please apply the following replacements: o "7777" --> the assigned port value for "netconf-ch-ssh" o "8888" --> the assigned port value for "netconf-ch-tls" o "9999" --> the assigned port value for "restconf-ch-tls" Artwork in this document contains placeholder values for the date of publication of this draft. Please apply the following replacement: - o "2014-12-11" --> the publication date of this draft + o "2015-02-02" --> the publication date of this draft The following two Appendix sections are to be removed prior to publication: o Appendix B. Change Log o Appendix C. Open Issues Status of This Memo @@ -82,48 +79,49 @@ 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 http://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 June 14, 2015. + This Internet-Draft will expire on August 6, 2015. Copyright Notice - Copyright (c) 2014 IETF Trust and the persons identified as the + Copyright (c) 2015 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 (http://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 4 1.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 4 1.2. Tree Diagrams . . . . . . . . . . . . . . . . . . . . . . 4 2. Objectives . . . . . . . . . . . . . . . . . . . . . . . . . 5 2.1. Support all NETCONF and RESTCONF transports . . . . . . . 5 2.2. Enable each transport to select which keys to use . . . . 5 - 2.3. Support authenticating NETCONF clients certificates . . . 5 - 2.4. Support mapping authenticated NETCONF client-certificates - to usernames . . . . . . . . . . . . . . . . . . . . . . 6 + 2.3. Support authenticating NETCONF/RESTCONF clients + certificates . . . . . . . . . . . . . . . . . . . . . . 5 + 2.4. Support mapping authenticated NETCONF/RESTCONF client + certificates to usernames . . . . . . . . . . . . . . . . 6 2.5. Support both Listening for connections and Call Home . . 6 2.6. For Call Home connections . . . . . . . . . . . . . . . . 6 2.6.1. Support more than one northbound application . . . . 6 2.6.2. Support applications having more than one server . . 6 2.6.3. Support a reconnection strategy . . . . . . . . . . . 6 2.6.4. Support both persistent and periodic connections . . 7 2.6.5. Reconnection strategy for periodic connections . . . 7 2.6.6. Keep-alives for persistent connections . . . . . . . 7 2.6.7. Customizations for periodic connections . . . . . . . 7 3. The NETCONF Server Configuration Model . . . . . . . . . . . 8 @@ -131,43 +129,45 @@ 3.1.1. The "session-options" subtree . . . . . . . . . . . . 8 3.1.2. The "listen" subtree . . . . . . . . . . . . . . . . 8 3.1.3. The "call-home" subtree . . . . . . . . . . . . . . . 9 3.1.4. The "ssh" subtree . . . . . . . . . . . . . . . . . . 11 3.1.5. The "tls" subtree . . . . . . . . . . . . . . . . . . 11 3.2. YANG Module . . . . . . . . . . . . . . . . . . . . . . . 12 4. The RESTCONF Server Configuration Model . . . . . . . . . . . 25 4.1. Overview . . . . . . . . . . . . . . . . . . . . . . . . 25 4.1.1. The "listen" subtree . . . . . . . . . . . . . . . . 25 4.1.2. The "call-home" subtree . . . . . . . . . . . . . . . 26 + 4.1.3. The "client-cert-auth" subtree . . . . . . . . . . . 28 4.2. YANG Module . . . . . . . . . . . . . . . . . . . . . . . 28 + 5. Implementation strategy for keep-alives . . . . . . . . . . . 39 + 5.1. Keep-alives for SSH . . . . . . . . . . . . . . . . . . . 39 + 5.2. Keep-alives for TLS . . . . . . . . . . . . . . . . . . . 40 - 5. Implementation strategy for keep-alives . . . . . . . . . . . 36 - 5.1. Keep-alives for SSH . . . . . . . . . . . . . . . . . . . 37 - 5.2. Keep-alives for TLS . . . . . . . . . . . . . . . . . . . 37 - 6. Security Considerations . . . . . . . . . . . . . . . . . . . 37 - 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 38 - 8. Other Considerations . . . . . . . . . . . . . . . . . . . . 39 - 9. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 39 - 10. References . . . . . . . . . . . . . . . . . . . . . . . . . 39 - 10.1. Normative References . . . . . . . . . . . . . . . . . . 39 - 10.2. Informative References . . . . . . . . . . . . . . . . . 40 - Appendix A. Examples . . . . . . . . . . . . . . . . . . . . . . 41 - A.1. NETCONF Configuration using SSH Transport . . . . . . . . 41 - A.2. NETCONF Configuration using TLS Transport . . . . . . . . 42 - A.3. RESTCONF Configuration using TLS Transport . . . . . . . 44 - Appendix B. Change Log . . . . . . . . . . . . . . . . . . . . . 44 - B.1. 00 to 01 . . . . . . . . . . . . . . . . . . . . . . . . 44 - B.2. 01 to 02 . . . . . . . . . . . . . . . . . . . . . . . . 45 - B.3. 02 to 03 . . . . . . . . . . . . . . . . . . . . . . . . 45 - B.4. 03 to 04 . . . . . . . . . . . . . . . . . . . . . . . . 45 - B.5. 04 to 05 . . . . . . . . . . . . . . . . . . . . . . . . 45 - Appendix C. Open Issues . . . . . . . . . . . . . . . . . . . . 46 + 6. Security Considerations . . . . . . . . . . . . . . . . . . . 40 + 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 41 + 8. Other Considerations . . . . . . . . . . . . . . . . . . . . 41 + 9. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 42 + 10. References . . . . . . . . . . . . . . . . . . . . . . . . . 42 + 10.1. Normative References . . . . . . . . . . . . . . . . . . 42 + 10.2. Informative References . . . . . . . . . . . . . . . . . 43 + Appendix A. Examples . . . . . . . . . . . . . . . . . . . . . . 44 + A.1. NETCONF Configuration using SSH Transport . . . . . . . . 44 + A.2. NETCONF Configuration using TLS Transport . . . . . . . . 45 + A.3. RESTCONF Configuration using TLS Transport . . . . . . . 47 + Appendix B. Change Log . . . . . . . . . . . . . . . . . . . . . 47 + B.1. 00 to 01 . . . . . . . . . . . . . . . . . . . . . . . . 47 + B.2. 01 to 02 . . . . . . . . . . . . . . . . . . . . . . . . 48 + B.3. 02 to 03 . . . . . . . . . . . . . . . . . . . . . . . . 48 + B.4. 03 to 04 . . . . . . . . . . . . . . . . . . . . . . . . 48 + B.5. 04 to 05 . . . . . . . . . . . . . . . . . . . . . . . . 48 + B.6. 05 to 06 . . . . . . . . . . . . . . . . . . . . . . . . 49 + Appendix C. Open Issues . . . . . . . . . . . . . . . . . . . . 49 1. Introduction This draft defines a NETCONF [RFC6241] server configuration data model and a RESTCONF [draft-ietf-netconf-restconf] server configuration data model. These data models enable configuration of the NETCONF and RESTCONF services themselves, including which transports are supported, what ports the servers listens on, whether call-home is supported, and associated parameters. @@ -178,20 +178,23 @@ document are to be interpreted as described in RFC 2119 [RFC2119]. 1.2. Tree Diagrams A simplified graphical representation of the data models is used in this document. The meaning of the symbols in these diagrams is as follows: o Brackets "[" and "]" enclose list keys. + o Braces "{" and "}" enclose feature names, and indicate that the + named feature must be present for the subtree to be present. + o Abbreviations before data node names: "rw" means configuration (read-write) and "ro" state data (read-only). o Symbols after data node names: "?" means an optional node, "!" means a presence container, and "*" denotes a list and leaf-list. o Parentheses enclose choice and case nodes, and case nodes are also marked with a colon (":"). o Ellipsis ("...") stands for contents of subtrees that are not @@ -217,37 +220,36 @@ 2.2. Enable each transport to select which keys to use Servers may have a multiplicity of host-keys or server-certificates from which subsets may be selected for specific uses. For instance, a NETCONF server may want to use one set of SSH host-keys when listening on port 830, and a different set of SSH host-keys when calling home. The data models provided herein should enable configuration of which keys to use on a per-use basis. -2.3. Support authenticating NETCONF clients certificates +2.3. Support authenticating NETCONF/RESTCONF clients certificates - When a certificate is used to authenticate a NETCONF client, either - when using the TLS transport or the SSH transport with X.509 - certificates [RFC6187], there is a need to configure the server to - know how to authenticate the certificates. The server should be able - to do this either by using path-validation to a configured trust - anchor or by matching the client-certificate to one previously - configured. + When a certificate is used to authenticate a NETCONF or RESTCONF + client, there is a need to configure the server to know how to + authenticate the certificates. The server should be able to + authenticate the client's certificate either by using path-validation + to a configured trust anchor or by matching the client-certificate to + one previously configured. -2.4. Support mapping authenticated NETCONF client-certificates to - usernames +2.4. Support mapping authenticated NETCONF/RESTCONF client certificates + to usernames - Some NETCONF transports (e.g., TLS) need additional support to map - authenticated transport-level sessions to a NETCONF username. The - NETCONF server model defined herein should define an ability for this - mapping to be configured." + When a client certifcate is used for TLS transport-level + authentication, the NETCONF/RESTCONF server must be able to derive a + username from the authenticated certifcate. Thus the modules defined + herein should enable this mapping to be configured. 2.5. Support both Listening for connections and Call Home The NETCONF and RESTCONF protocols were originally defined as having the server opening a port to listen for client connections. More recently the NETCONF working group defined support for call-home ([draft-ietf-netconf-call-home]), enabling the server to initiate the connection to the client, for both the NETCONF and RESTCONF protocols. Thus the modules defined herein should enable configuration for both listening for connections and calling home. @@ -305,21 +307,21 @@ clear when considering that a periodic "connection" is a logical connection to a single server. That is, the periods of unconnectedness are intentional as opposed to due to external reasons. A periodic "connection" should always reconnect to the same server until it is no longer able to, at which time the reconnection strategy guides how to connect to another server. 2.6.6. Keep-alives for persistent connections If a persistent connection is desired, it is the responsibility of - the connection-initiator to actively test the "aliveness" of the + the connection initiator to actively test the "aliveness" of the connection. The connection initiator must immediately work to reestablish a persistent connection as soon as the connection is lost. How often the connection should be tested is driven by application requirements, and therefore keep-alive settings should be configurable on a per-application basis. 2.6.7. Customizations for periodic connections If a periodic connection is desired, it is necessary for the device to know how often it should connect. This delay essentially @@ -338,30 +340,29 @@ time of no data being transmitted as transpired. 3. The NETCONF Server Configuration Model 3.1. Overview 3.1.1. The "session-options" subtree module: ietf-netconf-server +--rw netconf-server - +--rw session-options {session-options}? + +--rw session-options +--rw hello-timeout? uint32 +--rw idle-timeout? uint32 The above subtree illustrates how the ietf-netconf-server YANG module enables configuration of NETCONF session options, independent of any - transport or connection strategy. A feature statement is used for - the server to advertise support for configuring these NETCONF server - options. Please see the YANG module (Section 3.2) for a complete - description of these configuration knobs. + transport or connection strategy. Please see the YANG module + (Section 3.2) for a complete description of these configuration + knobs. 3.1.2. The "listen" subtree module: ietf-netconf-server +--rw netconf-server +--rw listen {listen}? +--rw max-sessions? uint16 +--rw endpoint* [name] +--rw name string +--rw (transport) | +--:(ssh) {ssh}? @@ -375,30 +376,29 @@ | +--rw address? inet:ip-address | +--rw port? inet:port-number | +--rw certificates | +--rw certificate* string +--rw keep-alives +--rw interval-secs? uint8 +--rw count-max? uint8 The above subtree illustrates how the ietf-netconf-server YANG module enables configuration for listening for remote connections, as - described in [RFC6242] and [draft-ietf-netconf-call-home]. Feature - statements are used to limit both if listening is supported at all as - well as for which transports. If listening for connections is - supported, then the model enables configuring a list of listening - endpoints, each configured with a user-specified name (the key - field), the transport to use (i.e. SSH, TLS), and the IP address and - port to listen on. The port field is optional, defaulting to the - transport-specific port when not configured. Please see the YANG - module (Section 3.2) for a complete description of these - configuration knobs. + described in [RFC6242]. Feature statements are used to limit both if + listening is supported at all as well as for which transports. If + listening for connections is supported, then the model enables + configuring a list of listening endpoints, each configured with a + user-specified name (the key field), the transport to use (i.e. SSH, + TLS), and the IP address and port to listen on. The port field is + optional, defaulting to the transport-specific port when not + configured. Please see the YANG module (Section 3.2) for a complete + description of these configuration knobs. 3.1.3. The "call-home" subtree module: ietf-netconf-server +--rw netconf-server +--rw call-home {call-home}? +--rw application* [name] +--rw name string +--rw (transport) | +--:(ssh) {ssh}? | | +--rw ssh @@ -447,21 +447,21 @@ the connection-type (persistent vs. periodic) and associated parameters, as well as the reconnection strategy to use. Please see the YANG module (Section 3.2) for a complete description of these configuration knobs. 3.1.4. The "ssh" subtree module: ietf-netconf-server +--rw netconf-server +--rw ssh {ssh}? - +--rw x509 {rfc6187}? + +--rw x509 {ssh-x509-certs}? +--rw trusted-ca-certs | +--rw trusted-ca-cert* binary +--rw trusted-client-certs +--rw trusted-client-cert* binary The above subtree illustrates how the ietf-netconf-server YANG module enables some SSH configuration independent of if the NETCONF server is listening or calling home. Specifically, when RFC 6187 is supported, this data model provides an ability to configure how client-certificates are authenticated. Please see the YANG module @@ -488,37 +488,40 @@ The above subtree illustrates how the ietf-netconf-server YANG module enables TLS configuration independent of if the NETCONF server is listening or calling home. Specifically, this data-model provides 1) an ability to configure how client-certificates are authenticated and 2) how authenticated client-certificates are mapped to NETCONF user names. Please see the YANG module (Section 3.2) for a complete description of these configuration knobs. 3.2. YANG Module - This YANG module imports YANG types from [RFC6991], and - [draft-ietf-netmod-snmp-cfg]. + This YANG module imports YANG types from [RFC6991] and [RFC7407]. - file "ietf-netconf-server@2014-12-11.yang" + file "ietf-netconf-server@2015-02-02.yang" module ietf-netconf-server { namespace "urn:ietf:params:xml:ns:yang:ietf-netconf-server"; prefix "ncserver"; + import ietf-netconf-acm { + prefix nacm; // RFC 6536 + revision-date 2012-02-22; + } import ietf-inet-types { // RFC 6991 prefix inet; revision-date 2013-07-15; } - import ietf-x509-cert-to-name { // RFC ZZZZ + import ietf-x509-cert-to-name { // RFC 7407 prefix x509c2n; - revision-date 2014-05-06; + revision-date 2014-12-10; } organization "IETF NETCONF (Network Configuration) Working Group"; contact "WG Web: WG List: WG Chair: Mehmet Ersue @@ -540,35 +543,29 @@ 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 VVVV; see the RFC itself for full legal notices."; - revision "2014-12-11" { + revision "2015-02-02" { description "Initial version"; reference "RFC VVVV: NETCONF Server and RESTCONF Server Configuration Models"; } // Features - feature session-options { - description - "The session-options feature indicates that the NETCONF server - supports the session-options container."; - } - feature ssh { description "The ssh feature indicates that the server supports the SSH transport protocol."; reference "RFC 6242: Using the NETCONF Protocol over Secure Shell (SSH)"; } feature tls { description @@ -579,58 +576,57 @@ } feature listen { description "The listen feature indicates that the server supports opening a port to listen for incoming client connections."; reference "RFC 6242: Using the NETCONF Protocol over Secure Shell (SSH) RFC 5539: NETCONF over Transport Layer Security (TLS)"; } - feature call-home { description "The call-home feature indicates that the server supports connecting to the client"; reference "RFC YYYY: NETCONF Call Home and RESTCONF Call Home"; } - feature rfc6187 { + feature ssh-x509-certs { description - "The rfc6187 feature indicates that the NETCONF server supports - RFC 6187"; + "The ssh-x509-certs feature indicates that the NETCONF server + supports RFC 6187"; reference "RFC 6187: X.509v3 Certificates for Secure Shell Authentication"; } // top-level container (groupings below) container netconf-server { description "Top-level container for NETCONF server configuration."; uses session-options-container; uses listen-container; uses call-home-container; uses ssh-container; uses tls-container; } grouping session-options-container { description - ""; + "This grouping is used only to help improve readability + of the YANG module."; container session-options { description - "NETCONF session options, independent of transport or - connection strategy."; - if-feature session-options; + "NETCONF session options, independent of transport + or connection strategy."; leaf hello-timeout { type uint32 { range "0 | 10 .. 3600"; } units "seconds"; default '600'; description "Specifies the number of seconds that a session may exist before the hello PDU is received. A session will be dropped if no hello PDU is received before this number @@ -661,43 +657,44 @@ This mechanism is independent of keep-alives, as it regards activity occurring at the NETCONF protocol layer, whereas the keep-alive mechanism regards transport-level activity."; } } } grouping listen-container { description - ""; + "This grouping is used only to help improve readability + of the YANG module."; container listen { description "Configures listen behavior"; if-feature listen; leaf max-sessions { type uint16 { range "0 .. 1024"; } default '0'; description "Specifies the maximum number of concurrent sessions that can be active at one time. The value 0 indicates that no artificial session limit should be used."; } list endpoint { key name; description - "List of endpoints to listen for connections on."; + "List of endpoints to listen for NETCONF connections on."; leaf name { type string; description - "An arbitrary name for the listen endpoint."; + "An arbitrary name for the NETCONF listen endpoint."; } choice transport { mandatory true; description "Selects between SSH and TLS transports."; case ssh { if-feature ssh; container ssh { description "SSH-specific listening configuration for inbound @@ -729,21 +726,22 @@ refine keep-alives/interval-secs { default 0; // disabled by default for listen connections } } } } } grouping call-home-container { description - ""; + "This grouping is used only to help improve readability + of the YANG module."; container call-home { if-feature call-home; description "Configures call-home behavior"; list application { key name; description "List of NETCONF clients the NETCONF server is to initiate call-home connections to."; leaf name { @@ -779,21 +777,21 @@ refine endpoints/endpoint/port { default 8888; } } uses certificates-container; } } } container connection-type { description - "Indicates the kind of connection to be maintained."; + "Indicates the kind of connection to use."; choice connection-type { default persistent-connection; description "Selects between persistent and periodic connections."; case persistent-connection { container persistent { description "Maintain a persistent connection to the NETCONF client. If the connection goes down, immediately start trying to reconnect to it, using the @@ -897,39 +895,40 @@ connect to a specific endpoint before moving on to the next endpoint in the list (round robin)."; } } } } } grouping ssh-container { description - ""; + "This grouping is used only to help improve readability + of the YANG module."; container ssh { description "Configures SSH properties not specific to the listen or call-home use-cases"; if-feature ssh; container x509 { - if-feature rfc6187; + if-feature ssh-x509-certs; uses trusted-certs-grouping; } } } grouping tls-container { description - ""; + "This grouping is used only to help improve readability + of the YANG module."; container tls { description - "Configures TLS properties not specific to the listen - or call-home use-cases"; + "Configures TLS properties for authenticating clients."; if-feature tls; container client-auth { description "Container for TLS client authentication configuration."; uses trusted-certs-grouping; container cert-maps { uses x509c2n:cert-to-name; description "The cert-maps container is used by a NETCONF server to map the NETCONF client's presented X.509 certificate to a @@ -937,39 +936,41 @@ list entry can be found, then the NETCONF server MUST close the connection, and MUST NOT accept NETCONF messages over it."; } } } } grouping trusted-certs-grouping { description - ""; + "This grouping is used by both the ssh and tls containers."; container trusted-ca-certs { description "A list of Certificate Authority (CA) certificates that a NETCONF server can use to authenticate NETCONF client certificates. A client's certificate is authenticated if there is a chain of trust to a configured trusted CA certificate. The client certificate MAY be accompanied with additional certificates forming a chain of trust. The client's certificate is authenticated if there is path-validation from any of the certificates it presents to a configured trust anchor."; leaf-list trusted-ca-cert { type binary; ordered-by system; + nacm:default-deny-write; description "The binary certificate structure as specified by RFC 5246, Section 7.4.6, i.e.,: opaque ASN.1Cert<1..2^24>; "; + reference "RFC 5246: The Transport Layer Security (TLS) Protocol Version 1.2"; } } container trusted-client-certs { description "A list of client certificates that a NETCONF server can use to authenticate a NETCONF client's certificate. A client's certificate is authenticated if it is an exact @@ -970,37 +971,39 @@ } container trusted-client-certs { description "A list of client certificates that a NETCONF server can use to authenticate a NETCONF client's certificate. A client's certificate is authenticated if it is an exact match to a configured trusted client certificates."; leaf-list trusted-client-cert { type binary; ordered-by system; + nacm:default-deny-write; description "The binary certificate structure, as specified by RFC 5246, Section 7.4.6, i.e.,: opaque ASN.1Cert<1..2^24>; "; reference "RFC 5246: The Transport Layer Security (TLS) Protocol Version 1.2"; } } } grouping host-keys-container { description - ""; + "This grouping is used by both the listen and + call-home containers"; container host-keys { description "Parent container for the list of host-keys."; leaf-list host-key { type string; min-elements 1; ordered-by user; description "A user-ordered list of host-keys the SSH server considers when composing the list of server host @@ -1012,21 +1015,22 @@ envisioned to be the keys for a list of host-keys provided by another YANG module"; reference "RFC 4253: The SSH Transport Layer Protocol, Section 7"; } } } grouping certificates-container { description - ""; + "This grouping is used by both the listen and + call-home containers"; container certificates { description "Parent container for the list of certificates."; leaf-list certificate { type string; min-elements 1; description "An unordered list of certificates the TLS server can pick from when sending its Server Certificate message. The value of the string is the unique identifier for a certificate @@ -1035,21 +1039,22 @@ to be the keys for a list of certificates provided by another YANG module"; reference "RFC 5246: The TLS Protocol, Section 7.4.2"; } } } grouping address-and-port-grouping { description - "a common grouping"; + "This grouping is usd by both the ssh and tls containers + for listen configuration."; leaf address { type inet:ip-address; description "The IP address of the interface to listen on."; } leaf port { type inet:port-number; description "The local port number on this interface the NETCONF server listens on."; @@ -1048,25 +1053,24 @@ description "The IP address of the interface to listen on."; } leaf port { type inet:port-number; description "The local port number on this interface the NETCONF server listens on."; } } - grouping endpoints-container { description - "Grouping for transport-specific configuration for - call-home connections."; + "This grouping is used by both the ssh and tls containers + for call-home configurations."; 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 NETCONF client. Defining more than one enables high-availability."; @@ -1090,26 +1094,25 @@ description "The IP port for this endpoint. The NETCONF server will use the IANA-assigned well-known port if not specified."; } } } } grouping keep-alives-container { description - ""; + "This grouping is use by both listen and call-home configurations."; container keep-alives { description "Configures the keep-alive policy, to proactively test the - aliveness of the NETCONF client, in order to know when a - new call home connection should be established."; + aliveness of the NETCONF client."; reference "RFC VVVV: NETCONF Server and RESTCONF Server Configuration Models, Section 4"; leaf interval-secs { type uint8; units seconds; description "Sets a timeout interval in seconds after which if no data has been received from the NETCONF client, a message will be sent to request a response from the NETCONF client. A @@ -1120,21 +1123,22 @@ type uint8; default 3; description "Sets the number of keep-alive messages that may be sent without receiving any data from the NETCONF client before assuming the NETCONF client is no longer alive. If this threshold is reached, the transport-level connection will be disconnected, which will trigger the reconnection strategy). The interval timer is reset after each transmission, thus an unresponsive NETCONF client will - be dropped after ~count-max * interval-secs seconds."; + be dropped after approximately (count-max * interval-secs) + seconds."; } } } } 4. The RESTCONF Server Configuration Model 4.1. Overview @@ -1152,28 +1156,27 @@ | +--rw address? inet:ip-address | +--rw port? inet:port-number | +--rw certificates | +--rw certificate* string +--rw keep-alives +--rw interval-secs? uint8 +--rw count-max? uint8 The above subtree illustrates how the ietf-restconf-server YANG module enables configuration for listening for remote connections, as - described in [draft-ietf-netconf-restconf] and - [draft-ietf-netconf-call-home]. Feature statements are used to limit - both if listening is supported at all as well as for which - transports. If listening for connections is supported, then the - model enables configuring a list of listening endpoints, each + described in [draft-ietf-netconf-restconf]. Feature statements are + used to limit both if listening is supported at all as well as for + which transports. If listening for connections is supported, then + the model enables configuring a list of listening endpoints, each configured with a user-specified name (the key field), the transport - to use (i.e. SSH, TLS), and the IP address and port to listen on. - The port field is optional, defaulting to the transport-specific port + to use (i.e. TLS), and the IP address and port to listen on. The + port field is optional, defaulting to the transport-specific port when not configured. Please see the YANG module (Section 4.2) for a complete description of these configuration knobs. 4.1.2. The "call-home" subtree module: ietf-restconf-server +--rw restconf-server +--rw call-home {call-home}? +--rw application* [name] +--rw name string +--rw (transport) @@ -1202,44 +1205,75 @@ +--rw interval-secs? uint8 +--rw count-max? uint8 The above subtree illustrates how the ietf-restconf-server YANG module enables configuration for call home, as described in [draft-ietf-netconf-call-home]. Feature statements are used to limit both if call-home is supported at all as well as for which transports, if it is. If call-home is supported, then the model supports configuring a list of applications to connect to. Each application is configured with a user-specified name (the key field), - the transport to be used (i.e. SSH, TLS), and a list of remote - endpoints, each having a name, an IP address, and an optional port. + the transport to be used (i.e. TLS), and a list of remote endpoints, + each having a name, an IP address, and an optional port. Additionally, the configuration for each remote application indicates the connection-type (persistent vs. periodic) and associated parameters, as well as the reconnection strategy to use. Please see the YANG module (Section 4.2) for a complete description of these configuration knobs. +4.1.3. The "client-cert-auth" subtree + + module: ietf-restconf-server + +--rw restconf-server + +--rw client-cert-auth {client-cert-auth}? + +--rw trusted-ca-certs + | +--rw trusted-ca-cert* binary + +--rw trusted-client-certs + | +--rw trusted-client-cert* binary + +--rw cert-maps + +--rw cert-to-name* [id] + +--rw id uint32 + +--rw fingerprint x509c2n:tls-fingerprint + +--rw map-type identityref + +--rw name string + + The above subtree illustrates how the ietf-restconf-server YANG + module enables configuration of client-certificate authentication. + Specifically, this data-model provides 1) an ability to configure how + client-certificates are authenticated and 2) how authenticated + client-certificates are mapped to RESTCONF user names. Please see + the YANG module (Section 4.2) for a complete description of these + configuration knobs. + 4.2. YANG Module - This YANG module imports YANG types from [RFC6991]. + This YANG module imports YANG types from [RFC6991] and [RFC7407]. - file "ietf-restconf-server@2014-12-11.yang" + file "ietf-restconf-server@2015-02-02.yang" module ietf-restconf-server { namespace "urn:ietf:params:xml:ns:yang:ietf-restconf-server"; prefix "rcserver"; + import ietf-netconf-acm { + prefix nacm; // RFC 6536 + revision-date 2012-02-22; + } import ietf-inet-types { // RFC 6991 prefix inet; revision-date 2013-07-15; } - + import ietf-x509-cert-to-name { // RFC 7407 + prefix x509c2n; + revision-date 2014-12-10; + } organization "IETF NETCONF (Network Configuration) Working Group"; contact "WG Web: WG List: WG Chair: Mehmet Ersue @@ -1259,21 +1293,21 @@ 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 VVVV; see the RFC itself for full legal notices."; - revision "2014-12-11" { + revision "2015-02-02" { description "Initial version"; reference "RFC VVVV: NETCONF Server and RESTCONF Server Configuration Models"; } // Features feature tls { description @@ -1287,72 +1322,82 @@ description "The listen feature indicates that the server supports opening a port to listen for incoming client connections."; reference "RFC XXXX: RESTCONF Protocol"; } feature call-home { description "The call-home feature indicates that the server supports - connecting to the client"; + connecting to the client."; reference "RFC YYYY: NETCONF Call Home and RESTCONF Call Home"; } + feature client-cert-auth { + description + "The client-cert-auth feature indicatres that the server + supports the ClientCertificate authentication scheme."; + reference + "RFC ZZZZ: Client Authentication over New TLS Connection"; + } + // top-level container (groupings below) container restconf-server { description "Top-level container for RESTCONF server configuration."; uses listen-container; uses call-home-container; + uses client-cert-auth-container; } grouping listen-container { description - ""; + "This grouping is used only to help improve readability + of the YANG module."; container listen { description "Configures listen behavior"; if-feature listen; leaf max-sessions { type uint16 { range "0 .. 1024"; } default '0'; description "Specifies the maximum number of concurrent sessions that can be active at one time. The value 0 indicates that no artificial session limit should be used."; } list endpoint { key name; description - "List of endpoints to listen for connections on."; + "List of endpoints to listen for RESTCONF connections on."; leaf name { type string; description - "An arbitrary name for the listen endpoint."; + "An arbitrary name for the RESTCONF listen endpoint."; } choice transport { mandatory true; description "Selects between available transports."; case tls { container tls { description "TLS-specific listening configuration for inbound connections."; uses address-and-port-grouping { refine port { - default 6513; + default 443; } } uses certificates-container; } } } uses keep-alives-container { refine keep-alives/interval-secs { default 0; // disabled by default for listen connections } @@ -1350,46 +1395,46 @@ } uses certificates-container; } } } uses keep-alives-container { refine keep-alives/interval-secs { default 0; // disabled by default for listen connections } } - } } } grouping call-home-container { description - ""; + "This grouping is used only to help improve readability + of the YANG module."; container call-home { if-feature call-home; description "Configures call-home behavior"; list application { key name; description "List of RESTCONF clients the RESTCONF server is to initiate call-home connections to."; leaf name { type string; description "An arbitrary name for the remote RESTCONF client."; } choice transport { mandatory true; description - "Selects between SSH and TLS transports."; + "Selects between TLS and any future transports augmented in."; case tls { if-feature tls; container tls { description "Specifies TLS-specific call-home transport configuration."; uses endpoints-container { refine endpoints/endpoint/port { default 9999; } @@ -1511,23 +1555,92 @@ 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)."; } } } } } + grouping client-cert-auth-container { + description + "This grouping is used only to help improve readability + of the YANG module."; + container client-cert-auth { + if-feature client-cert-auth; + description + "Container for TLS client certificate authentication + configuration."; + container trusted-ca-certs { + description + "A list of Certificate Authority (CA) certificates that + a NETCONF server can use to authenticate NETCONF client + certificates. A client's certificate is authenticated + if there is a chain of trust to a configured trusted CA + certificate. The client certificate MAY be accompanied + with additional certificates forming a chain of trust. + The client's certificate is authenticated if there is + path-validation from any of the certificates it presents + to a configured trust anchor."; + leaf-list trusted-ca-cert { + type binary; + ordered-by system; + nacm:default-deny-write; + description + "The binary certificate structure as specified by RFC + 5246, Section 7.4.6, i.e.,: opaque ASN.1Cert<1..2^24>; + "; + reference + "RFC 5246: The Transport Layer Security (TLS) + Protocol Version 1.2"; + } + } + container trusted-client-certs { + description + "A list of client certificates that a NETCONF server can + use to authenticate a NETCONF client's certificate. A + client's certificate is authenticated if it is an exact + match to a configured trusted client certificates."; + leaf-list trusted-client-cert { + type binary; + ordered-by system; + nacm:default-deny-write; + description + "The binary certificate structure, as + specified by RFC 5246, Section 7.4.6, i.e.,: + + opaque ASN.1Cert<1..2^24>; + + "; + reference + "RFC 5246: The Transport Layer Security (TLS) + Protocol Version 1.2"; + } + } + container cert-maps { + uses x509c2n:cert-to-name; + description + "The cert-maps container is used by a NETCONF server to + map the NETCONF client's presented X.509 certificate to a + NETCONF username. If no matching and valid cert-to-name + list entry can be found, then the NETCONF server MUST + close the connection, and MUST NOT accept NETCONF + messages over it."; + } + } + } + grouping certificates-container { description - ""; + "This grouping is used by both the listen and + call-home containers"; container certificates { description "Parent container for the list of certificates."; leaf-list certificate { type string; min-elements 1; description "An unordered list of certificates the TLS server can pick from when sending its Server Certificate message. The value of the string is the unique identifier for a certificate @@ -1536,38 +1649,39 @@ to be the keys for a list of certificates provided by another YANG module"; reference "RFC 5246: The TLS Protocol, Section 7.4.2"; } } } grouping address-and-port-grouping { description - "a common grouping"; + "This grouping is usd by both the ssh and tls containers + for listen configuration."; leaf address { type inet:ip-address; description "The IP address of the interface to listen on."; } leaf port { type inet:port-number; description "The local port number on this interface the RESTCONF server listens on."; } } grouping endpoints-container { description - "Grouping for transport-specific configuration for - call-home connections."; + "This grouping is used by both the ssh and tls containers + for call-home configurations."; 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."; @@ -1591,27 +1705,25 @@ description "The IP port for this endpoint. The RESTCONF server will use the IANA-assigned well-known port if not specified."; } } } } grouping keep-alives-container { description - ""; - + "This grouping is use by both listen and call-home configurations."; container keep-alives { description "Configures the keep-alive policy, to proactively test the - aliveness of the RESTCONF client, in order to know when a - new call home connection should be established."; + aliveness of the RESTCONF client."; reference "RFC VVVV: NETCONF Server and RESTCONF Server Configuration Models, Section 4"; leaf interval-secs { type uint8; units seconds; description "Sets a timeout interval in seconds after which if no data has been received from the RESTCONF client, a message will be sent to request a response from the RESTCONF client. A @@ -1622,21 +1734,22 @@ type uint8; default 3; description "Sets the number of keep-alive messages that may be sent without receiving any data from the RESTCONF client before assuming the RESTCONF client is no longer alive. If this threshold is reached, the transport-level connection will be disconnected, which will trigger the reconnection strategy). The interval timer is reset after each transmission, thus an unresponsive RESTCONF client will - be dropped after ~count-max * interval-secs seconds."; + be dropped after approximately (count-max * interval-secs) + seconds."; } } } } 5. Implementation strategy for keep-alives One of the objectives listed above, Keep-alives for persistent @@ -1697,35 +1810,45 @@ There are a number of data nodes defined in the "ietf-netconf-server" YANG module which are readable and/or writable that may be considered sensitive or vulnerable in some network environments. Write and read operations to these data nodes can have a negative effect on network operations. It is thus important to control write and read access to these data nodes. Below are the data nodes and their sensitivity/ vulnerability. netconf-server/tls/client-auth/trusted-ca-certs: - o This container contains certificates that the server is to use as - trust anchors for authenticating TLS-specific client certificates. - Write access to this node should be protected. + o This container contains certificates that a NETCONF server is to + use as trust anchors for authenticating X.509-based client + certificates. Write access to this node is protected using an + nacm:default-deny-write statement. netconf-server/tls/client-auth/trusted-client-certs: - o This container contains certificates that the server is to trust - directly when authenticating TLS-specific client certificates. - Write access to this node should be protected. + o This container contains certificates that a NETCONF server is to + trust directly when authenticating X.509-based client + certificates. Write access to this node is protected using an + nacm:default-deny-write statement. - netconf-server/tls/client-auth/cert-map: + restconf-server/tls/client-auth/trusted-ca-certs: - o This container contains a user name that some deployments may - consider sensitive information. Read access to this node may need - to be guarded. + o This container contains certificates that a RESTCONF server is to + use as trust anchors for authenticating X.509-based client + certificates. Write access to this node is protected using an + nacm:default-deny-write statement. + + restconf-server/tls/client-auth/trusted-client-certs: + + o This container contains certificates that a RESTCONF server is to + trust directly when authenticating X.509-based client + certificates. Write access to this node is protected using an + nacm:default-deny-write statement. 7. IANA Considerations This document registers two URIs in the IETF XML registry [RFC2119]. Following the format in [RFC3688], the following registrations are requested: URI: urn:ietf:params:xml:ns:yang:ietf-netconf-server Registrant Contact: The NETCONF WG of the IETF. XML: N/A, the requested URI is an XML namespace. @@ -1797,39 +1920,37 @@ Layer Security (TLS) and Datagram Transport Layer Security (DTLS) Heartbeat Extension", RFC 6520, February 2012. [RFC6536] Bierman, A. and M. Bjorklund, "Network Configuration Protocol (NETCONF) Access Control Model", RFC 6536, March 2012. [RFC6991] Schoenwaelder, J., "Common YANG Data Types", RFC 6991, July 2013. + [RFC7407] Bjorklund, M. and J. Schoenwaelder, "A YANG Data Model for + SNMP Configuration", RFC 7407, December 2014. + [draft-ietf-netconf-call-home] Watsen, K., "NETCONF Call Home and RESTCONF Call Home", draft-ieft-netconf-call-home-02 (work in progress), 2014. [draft-ietf-netconf-restconf] Bierman, A., Bjorklund, M., and K. Watsen, "RESTCONF Protocol", draft-ieft-netconf-restconf-04 (work in progress), 2014. [draft-ietf-netconf-rfc5539bis] Badra, M., Luchuk, A., and J. Schoenwaelder, "Using the NETCONF Protocol over Transport Layer Security (TLS)", draft-ietf-netconf-rfc5539bis-06 (work in progress), 2014. - [draft-ietf-netmod-snmp-cfg] - Bjorklund, M. and J. Schoenwaelder, "A YANG Data Model for - SNMP Configuration", draft-ietf-netmod-snmp-cfg-08 (work - in progress), September 2014. - 10.2. Informative References [RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688, January 2004. Appendix A. Examples A.1. NETCONF Configuration using SSH Transport The following example illustrates the response from a NETCONF @@ -2069,20 +2190,42 @@ o Added ability to configure trust-anchors for SSH X.509 client certs o Now imports by revision, per best practice o Added support for RESTCONF server o Added RFC Editor instructions +B.6. 05 to 06 + + o Removed feature statement on the session-options container (issue + #21). + + o Added NACM statements to YANG modules for sensitive nodes (issue + #24). + + o Fixed default RESTCONF server port value to be 443 (issue #26). + + o Added client-cert-auth subtree to ietf-restconf-server module + (issue #27). + + o Updated draft-ietf-netmod-snmp-cfg reference to RFC 7407 (issue + #28). + + o Added description statements for groupings (issue #29). + + o Added description for braces to tree diagram section (issue #30). + + o Renamed feature from "rfc6187" to "ssh-x509-certs" (issue #31). + Appendix C. Open Issues Please see: https://github.com/netconf-wg/server-model/issues. Authors' Addresses Kent Watsen Juniper Networks EMail: kwatsen@juniper.net