NETCONF Working Group K. Watsen Internet-Draft Juniper Networks Intended status: Standards Track J. Schoenwaelder Expires: April 11, 2016 Jacobs University Bremen October 9, 2015 NETCONF Server and RESTCONF Server Configuration Models draft-ietf-netconf-server-model-08 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 listen on, call-home parameters, client authentication, and related parameters. 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. Please note that no other RFC Editor instructions are specified anywhere else 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 draft-ietf-netconf-restconf o draft-ietf-netconf-call-home 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 "XXXX" --> the assigned RFC value for draft-ietf-netconf-restconf o "YYYY" --> the assigned RFC value for draft-ietf-netconf-call-home Artwork in this document contains placeholder values for ports pending IANA assignment from "draft-ietf-netconf-call-home". Please apply the following replacements: Watsen & Schoenwaelder Expires April 11, 2016 [Page 1] Internet-Draft NETCONF/RESTCONF Server Config Models October 2015 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 "2015-10-09" --> 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 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 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 April 11, 2016. Copyright Notice 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 Watsen & Schoenwaelder Expires April 11, 2016 [Page 2] Internet-Draft NETCONF/RESTCONF Server Config Models October 2015 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/RESTCONF clients certificates . . . . . . . . . . . . . . . . . . . . . . 5 2.4. Support mapping authenticated NETCONF/RESTCONF client certificates to usernames . . . . . . . . . . . . . . . . 5 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 NETCONF/RESTCONF client . . . . 6 2.6.2. Support NETCONF/RESTCONF clients having more than one endpoint . . . . . . . . . . . . . . . . . . . . . . 6 2.6.3. Support a reconnection strategy . . . . . . . . . . . 6 2.6.4. Support both persistent and periodic connections . . 6 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. High-Level Design . . . . . . . . . . . . . . . . . . . . . . 7 4. Solution . . . . . . . . . . . . . . . . . . . . . . . . . . 8 4.1. The Keychain Model . . . . . . . . . . . . . . . . . . . 8 4.1.1. Tree Diagram . . . . . . . . . . . . . . . . . . . . 9 4.1.2. Example Usage . . . . . . . . . . . . . . . . . . . . 9 4.1.3. YANG Model . . . . . . . . . . . . . . . . . . . . . 15 4.2. The SSH Server Model . . . . . . . . . . . . . . . . . . 20 4.2.1. Tree Diagram . . . . . . . . . . . . . . . . . . . . 21 4.2.2. Example Usage . . . . . . . . . . . . . . . . . . . . 21 4.2.3. YANG Model . . . . . . . . . . . . . . . . . . . . . 22 4.3. The TLS Server Model . . . . . . . . . . . . . . . . . . 26 4.3.1. Tree Diagram . . . . . . . . . . . . . . . . . . . . 26 4.3.2. Example Usage . . . . . . . . . . . . . . . . . . . . 27 4.3.3. YANG Model . . . . . . . . . . . . . . . . . . . . . 27 4.4. The NETCONF Server Model . . . . . . . . . . . . . . . . 31 4.4.1. Tree Diagram . . . . . . . . . . . . . . . . . . . . 31 4.4.2. Example Usage . . . . . . . . . . . . . . . . . . . . 33 4.4.3. YANG Model . . . . . . . . . . . . . . . . . . . . . 37 4.5. The RESTCONF Server Model . . . . . . . . . . . . . . . . 47 4.5.1. Tree Diagram . . . . . . . . . . . . . . . . . . . . 47 4.5.2. Example Usage . . . . . . . . . . . . . . . . . . . . 49 4.5.3. YANG Model . . . . . . . . . . . . . . . . . . . . . 51 5. Security Considerations . . . . . . . . . . . . . . . . . . . 59 Watsen & Schoenwaelder Expires April 11, 2016 [Page 3] Internet-Draft NETCONF/RESTCONF Server Config Models October 2015 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 59 7. Other Considerations . . . . . . . . . . . . . . . . . . . . 60 8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 60 9. References . . . . . . . . . . . . . . . . . . . . . . . . . 60 9.1. Normative References . . . . . . . . . . . . . . . . . . 61 9.2. Informative References . . . . . . . . . . . . . . . . . 61 Appendix A. Change Log . . . . . . . . . . . . . . . . . . . . . 62 A.1. 00 to 01 . . . . . . . . . . . . . . . . . . . . . . . . 62 A.2. 01 to 02 . . . . . . . . . . . . . . . . . . . . . . . . 62 A.3. 02 to 03 . . . . . . . . . . . . . . . . . . . . . . . . 62 A.4. 03 to 04 . . . . . . . . . . . . . . . . . . . . . . . . 62 A.5. 04 to 05 . . . . . . . . . . . . . . . . . . . . . . . . 63 A.6. 05 to 06 . . . . . . . . . . . . . . . . . . . . . . . . 63 A.7. 06 to 07 . . . . . . . . . . . . . . . . . . . . . . . . 63 A.8. 07 to 08 . . . . . . . . . . . . . . . . . . . . . . . . 64 Appendix B. Open Issues . . . . . . . . . . . . . . . . . . . . 65 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 listen on, call-home parameters, client authentication, and related parameters. 1.1. Terminology The keywords "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 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. Watsen & Schoenwaelder Expires April 11, 2016 [Page 4] Internet-Draft NETCONF/RESTCONF Server Config Models October 2015 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 shown. 2. Objectives The primary purpose of the YANG modules defined herein is to enable the configuration of the NETCONF and RESTCONF services on a network element. This scope includes the following objectives: 2.1. Support all NETCONF and RESTCONF transports The YANG module should support all current NETCONF and RESTCONF transports, namely NETCONF over SSH [RFC6242], NETCONF over TLS [RFC7589], and RESTCONF over TLS [draft-ietf-netconf-restconf], and to be extensible to support future transports as necessary. Because implementations may not support all transports, the module should use YANG "feature" statements so that implementations can accurately advertise which transports are supported. 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/RESTCONF clients certificates 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/RESTCONF client certificates to usernames When a client certificate is used for TLS client authentication, the NETCONF/RESTCONF server must be able to derive a username from the authenticated certificate. Thus the modules defined herein should enable this mapping to be configured. Watsen & Schoenwaelder Expires April 11, 2016 [Page 5] Internet-Draft NETCONF/RESTCONF Server Config Models October 2015 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. Because implementations may not support both listening for connections and calling home, YANG "feature" statements should be used so that implementation can accurately advertise the connection types it supports. 2.6. For Call Home connections The following objectives only pertain to call home connections. 2.6.1. Support more than one NETCONF/RESTCONF client A NETCONF/RESTCONF server may be managed by more than one NETCONF/ RESTCONF client. For instance, a deployment may have one client for provisioning and another for fault monitoring. Therefore, when it is desired for a server to initiate call home connections, it should be able to do so to more than one client. 2.6.2. Support NETCONF/RESTCONF clients having more than one endpoint An NETCONF/RESTCONF client managing a NETCONF/RESTCONF server may implement a high-availability strategy employing a multiplicity of active and/or passive endpoint. Therefore, when it is desired for a server to initiate call home connections, it should be able to connect to any of the client's endpoints. 2.6.3. Support a reconnection strategy Assuming a NETCONF/RESTCONF client has more than one endpoint, then it becomes necessary to configure how a NETCONF/RESTCONF server should reconnect to the client should it lose its connection to one the client's endpoints. For instance, the NETCONF/RESTCONF server may start with first endpoint defined in a user-ordered list of endpoints or with the last endpoints it was connected to. 2.6.4. Support both persistent and periodic connections NETCONF/RESTCONF clients may vary greatly on how frequently they need to interact with a NETCONF/RESTCONF server, how responsive interactions need to be, and how many simultaneous connections they Watsen & Schoenwaelder Expires April 11, 2016 [Page 6] Internet-Draft NETCONF/RESTCONF Server Config Models October 2015 can support. Some clients may need a persistent connection to servers to optimize real-time interactions, while others prefer periodic interactions in order to minimize resource requirements. Therefore, when it is necessary for server to initiate connections, it should be configurable if the connection is persistent or periodic. 2.6.5. Reconnection strategy for periodic connections The reconnection strategy should apply to both persistent and periodic connections. How it applies to periodic connections becomes 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 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 NETCONF/RESTCONF client requirements, and therefore keep-alive settings should be configurable on a per-client basis. 2.6.7. Customizations for periodic connections If a periodic connection is desired, it is necessary for the NETCONF/ RESTCONF server to know how often it should connect. This frequency determines the maximum amount of time a NETCONF/RESTCONF client may have to wait to send data to a server. A server may connect to a client before this interval expires if desired (e.g., to send data to a client). 3. High-Level Design The solution presented in this document defines a configurable keychain object, reusable groupings for SSH and TLS based servers, and, finally, the configurable NETCONF and RESTCONF server objects, which are the primary purpose for this draft. Each of these are defined in a distinct YANG module, thus a total of five YANG modules are defined in this document. The relationship between these five YANG modules is illustrated by the tree diagram below. Watsen & Schoenwaelder Expires April 11, 2016 [Page 7] Internet-Draft NETCONF/RESTCONF Server Config Models October 2015 +-------------+ |ietf-keychain| +-------------+ ^ ^ | | | | +------------+ +------------+ | | +---------------+ +------------------+ |ietf-ssh-server| | ietf-tls-server | +---------------+ +------------------+ ^ ^ ^ | | | | | | | +--------------------+ | | | | +-------------------+ +--------------------+ |ietf-netconf-server| |ietf-restconf-server| +-------------------+ +--------------------+ 4. Solution Each of the following five sections relate to one of the YANG modules depicted by the figure above. 4.1. The Keychain Model The keychain model depicted in this section provides a configurable object having the following characteristics: o A semi-configurable list of private keys, each with one or more associated certificates. Though private keys can only be created via an RPC (see bullet #3 below), the entries of the list may be renamed and have certificates associated with them after creation. o A configurable list of lists of trust anchor certificates. This enables the server to have use-specific trust anchors. For instance, one list of trust anchors might be used to authenticate management connections (e.g., client certificate-based authentication for NETCONF or RESTCONF connections), and a different list of trust anchors might be used for when connecting to a specific Internet-based service (e.g., a zero touch bootstrap server). o An RPC to request the server to generate a new private key using the specified algorithm and key length. Watsen & Schoenwaelder Expires April 11, 2016 [Page 8] Internet-Draft NETCONF/RESTCONF Server Config Models October 2015 o An RPC to generate a certificate signing request for an existing private key, a passed subject, and an optional attributes. The signed certificate returned from an external certificate authority (CA) can be set using a standard configuration change request (e.g., ). 4.1.1. Tree Diagram module: ietf-keychain +--rw keychain +--rw private-keys | +--rw private-key* [name] | | +--rw name string | | +--ro algorithm? enumeration | | +--ro key-length? uint32 | | +--ro public-key? string | | +--rw certificates | | | +--rw certificate* [name] | | | +--rw name string | | | +--rw chain? binary | | +---x generate-certificate-signing-request | | +---w input | | | +---w subject binary | | | +---w attributes? binary | | +--ro output | | +--ro certificate-signing-request binary | +---x generate-private-key | +---w input | +---w name string | +---w algorithm enumeration | +---w key-length? uint32 +--rw trusted-certificates* [name] +--rw name string +--rw description? string +--rw trusted-certificate* [name] +--rw name string +--rw certificate? binary 4.1.2. Example Usage The following example illustrates the "generate-private-key" RPC in use with the RESTCONF protocol and JSON encoding. Watsen & Schoenwaelder Expires April 11, 2016 [Page 9] Internet-Draft NETCONF/RESTCONF Server Config Models October 2015 REQUEST ------- ['\' line wrapping added for formatting only] POST https://example.com/restconf/data/ietf-keychain:keychain/\ private-keys/generate-private-key HTTP/1.1 HOST: example.com Content-Type: application/yang.operation+json { "ietf-keychain:input" : { "name" : "ex-key-sect571r1", "algorithm" : "sect571r1" } } RESPONSE -------- HTTP/1.1 204 No Content Date: Mon, 31 Oct 2015 11:01:00 GMT Server: example-server The following example illustrates the action statement "generate- certificate-signing-request" action in use with the NETCONF protocol. REQUEST ------- ex-key-sect571r1 cztvaWRoc2RmZ2tqaHNkZmdramRzZnZzZGtmam5idnNvO2R manZvO3NkZmJpdmhzZGZpbHVidjtvc2lkZmhidml1bHNlmO Z2aXNiZGZpYmhzZG87ZmJvO3NkZ25iO29pLmR6Zgo= bwtakWRoc2RmZ2tqaHNkZmdramRzZnZzZGtmam5idnNvut4 arnZvO3NkZmJpdmhzZGZpbHVidjtvc2lkZmhidml1bHNkYm Watsen & Schoenwaelder Expires April 11, 2016 [Page 10] Internet-Draft NETCONF/RESTCONF Server Config Models October 2015 Z2aXNiZGZpYmhzZG87ZmJvO3NkZ25iO29pLmC6Rhp= RESPONSE -------- LS0tLS1CRUdJTiBDRVJUSUZJQ0FURS0tLS0tCk1JSUNrekNDQWZ5Z 0F3SUJBZ0lKQUpRT2t3bGpNK2pjTUEwR0NTcUdTSWIzRFFFQkJRVU FNRFF4Q3pBSkJnTlYKQkFZVEFsVlRNUkF3RGdZRFZRUUtFd2RsZUd GdGNHeGxNUk13RVFZRFZRUURFd3BEVWt3Z1NYTnpkV1Z5TUI0WApE diR1V4RXpBUkJnTlZCQU1UQ2tOU1RDQkpjM04xWlhJd2daOHdEUVl KS29aSWh2Y04KQVFFQkJRQURnWTBBTUlHSkFvR0JBTXVvZmFPNEV3 El1QWMrQ1RsTkNmc0d6cEw1Um5ydXZsOFRIcUJTdGZQY3N0Zk1KT1 FaNzlnNlNWVldsMldzaHE1bUViCkJNNitGNzdjbTAvU25FcFE0TnV bXBDT2YKQWdNQkFBR2pnYXd3Z2Frd0hRWURWUjBPQkJZRUZKY1o2W URiR0lPNDB4ajlPb3JtREdsRUNCVTFNR1FHQTFVZApJd1JkTUZ1QU ZKY1o2WURiR0lPNDB4ajlPb3JtREdsRUNCVTFvVGlrTmpBME1Rc3d mMKTUE0R0ExVWREd0VCL3dRRUF3SUNCREFTQmdOVkhSTUJBZjhFQ0 RBR0FRSC9BZ0VBTUEwR0NTcUdTSWIzRFFFQgpCUVVBQTRHQkFMMmx rWmFGNWcyaGR6MVNhZnZPbnBneHA4eG00SHRhbStadHpLazFlS3Bx TXp4YXJCbFpDSHlLCklVbC9GVzRtV1RQS1VDeEtFTE40NEY2Zmk2d c4d0tSSElkYW1WL0pGTmlQS0VXSTF4K1I1aDZmazcrQzQ1QXg1RWV SWHgzZjdVM2xZTgotLS0tLUVORCBDRVJUSUZJQ0FURS0tLS0tCg== The following example illustrates what a fully configured keychain object might look like. The private-key shown below is consistent with the generate-private-key and generate-certificate-signing- request examples above. This example also assumes that the resulting CA-signed certificate has been configured back onto the server. Lastly, this example shows that three lists of trusted certificates having been configured. Watsen & Schoenwaelder Expires April 11, 2016 [Page 11] Internet-Draft NETCONF/RESTCONF Server Config Models October 2015 ex-key-sect571r1 sect571r1 cztvaWRoc2RmZ2tqaHNkZmdramRzZnZzZGtmam5idnNvO2RmanZvO3NkZ mJpdmhzZGZpbHVidjtvc2lkZmhidml1bHNkYmZ2aXNiZGZpYmhzZG87Zm JvO3NkZ25iO29pLmR6Zgo= ex-key-sect571r1-cert LS0tLS1CRUdJTiBDRVJUSUZJQ0FURS0tLS0tCk1JSUNrekNDQWZ5Z 0F3SUJBZ0lKQUpRT2t3bGpNK2pjTUEwR0NTcUdTSWIzRFFFQkJRVU FNRFF4Q3pBSkJnTlYKQkFZVEFsVlRNUkF3RGdZRFZRUUtFd2RsZUd GdGNHeGxNUk13RVFZRFZRUURFd3BEVWt3Z1NYTnpkV1Z5TUI0WApE diR1V4RXpBUkJnTlZCQU1UQ2tOU1RDQkpjM04xWlhJd2daOHdEUVl KS29aSWh2Y04KQVFFQkJRQURnWTBBTUlHSkFvR0JBTXVvZmFPNEV3 El1QWMrQ1RsTkNmc0d6cEw1Um5ydXZsOFRIcUJTdGZQY3N0Zk1KT1 FaNzlnNlNWVldsMldzaHE1bUViCkJNNitGNzdjbTAvU25FcFE0TnV bXBDT2YKQWdNQkFBR2pnYXd3Z2Frd0hRWURWUjBPQkJZRUZKY1o2W URiR0lPNDB4ajlPb3JtREdsRUNCVTFNR1FHQTFVZApJd1JkTUZ1QU ZKY1o2WURiR0lPNDB4ajlPb3JtREdsRUNCVTFvVGlrTmpBME1Rc3d mMKTUE0R0ExVWREd0VCL3dRRUF3SUNCREFTQmdOVkhSTUJBZjhFQ0 RBR0FRSC9BZ0VBTUEwR0NTcUdTSWIzRFFFQgpCUVVBQTRHQkFMMmx rWmFGNWcyaGR6MVNhZnZPbnBneHA4eG00SHRhbStadHpLazFlS3Bx TXp4YXJCbFpDSHlLCklVbC9GVzRtV1RQS1VDeEtFTE40NEY2Zmk2d c4d0tSSElkYW1WL0pGTmlQS0VXSTF4K1I1aDZmazcrQzQ1QXg1RWV SWHgzZjdVM2xZTgotLS0tLUVORCBDRVJUSUZJQ0FURS0tLS0tCg== explicitly-trusted-client-certs Specific client authentication certificates that are to be explicitly trusted NETCONF/RESTCONF clients. These are needed for client certificates not signed by our CA. George Jetson Watsen & Schoenwaelder Expires April 11, 2016 [Page 12] Internet-Draft NETCONF/RESTCONF Server Config Models October 2015 QmdOVkJBWVRBbFZUTVJBd0RnWURWUVFLRXdkbAplR0Z0Y0d4bE1RNHdEQ MkF6a3hqUDlVQWtHR0dvS1U1eUc1SVR0Wm0vK3B0R2FieXVDMjBRd2kvZ 25PZnpZNEhONApXY0pTaUpZK2xtYWs3RTRORUZXZS9RdGp4NUlXZmdvN2 RV0JCU2t2MXI2SFNHeUFUVkpwSmYyOWtXbUU0NEo5akJrQmdOVkhTTUVY VEJiZ0JTWEdlbUEKMnhpRHVOTVkvVHFLNWd4cFJBZ1ZOYUU0cERZd05ER UxNQWtHQTFVRUJoTUNWVk14RURBT0JnTlZCQW9UQjJWNApZVzF3YkdVeE V6QVJCZ05WQkFNVENrTlNUQ0JKYzNOMVpYS0NDUUNVRHBNSll6UG8zREF NQmdOVkhSTUJBZjhFCkFqQUFNQTRHQTFVZER3RUIvd1FFQXdJSGdEQnBC Z05WSFI4RVlqQmdNRjZnSXFBZ2hoNW9kSFJ3T2k4dlpYaGgKYlhCc1pTN WpiMjB2WlhoaGJYQnNaUzVqY215aU9LUTJNRFF4Q3pBSkJnTlZCQVlUQW xWVE1SQXdEZ1lEVlFRSwpFd2RsZUdGdGNHeGxNUk13RVFZRFZRUURFd3B EVWt3Z1NYTnpkV1Z5TUEwR0NTcUdTSWIzRFFFQkJRVUFBNEdCCkFFc3BK WmdsK2gyTTg3QmtGMjhWbW1CdFFVaWc3OEgrRkYyRTFwdSt4ZVRJbVFFM TQzcjFZSjk0M1FQLzV5eGUKN2QxMkxCV0dxUjUrbEl5N01YL21ka2M4al zSFNwSDdwVXBCYnA4dmtNanFtZjJma3RqZHBxeFppUUtTbndWZTF2Zwot LS0tLUVORCBDRVJUSUZJQ0FURS0tLS0tCg== Fred Flinstone VlEVlFRREV3Vm9ZWEJ3ZVRDQm56QU5CZ2txaGtpRzl3MEJBUUVGQUFPQm pRQXdnWWtDCmdZRUE1RzRFSWZsS1p2bDlXTW44eUhyM2hObUFRaUhVUzV rRUpPQy9hSFA3eGJXQW1ra054ZStUa2hrZnBsL3UKbVhsTjhSZUd1ODhG NGcEk3UE90cnNFVjRwTUNBd0VBQWFPQ0FSSXdnZ0VPCk1CMEdBMVVkRGd VEJiZ0JTWEdlbUEKMnhpRHVOTVkvVHFLNWd4cFJBZ1ZOYUU0cERZd05ER V6QVJCZ05WQkFNVENrTlNUQ0JKYzNOMVpYS0NDUUNVRHBNSll6UG8zREF NQmdOVkhSTUJBZjhFCkFqQUFNQTRHQTFVZER3RUIvd1FFQXdJSGdEQnBC Z05WSFI4RVlqQmdNRjZnSXFBZ2hoNW9kSFJ3T2k4dlpYaGgKYlhCc1pTN WpiMjB2WlhoaGJYQnNaUzVqY215aU9LUTJNRFF4Q3pBSkJnTlZCQVlUQW xWVE1SQXdEZ1lEVlFRSwpFd2RsZUdGdGNHeGxNUk13RVFZRFZRUURFd3B EVWt3Z1NYTnpkV1Z5TUEwR0NTcUdTSWIzRFFFQkJRVUFBNEdCCkFFc3BK WmdsK2gyTTg3QmtGMjhWbW1CdFFVaWc3OEgrRkYyRTFwdSt4ZVRJbVFFM lLQllsdWpOcjFTMnRLR05EMUc2OVJpK2FWNGw2NTdZNCtadVJMZgpRYjk zSFNwSDdwVXBCYnA4dmtNanFtZjJma3RqZHBxeFppUUtTbndWZTF2Zwot QWtUOCBDRVUUZJ0RUF== deployment-specific-ca-certs Trust anchors used only to authenticate NETCONF/RESTCONF client connections. Since our security policy only allows authentication for clients having a certificate signed by our CA, we only configure its certificate below. Watsen & Schoenwaelder Expires April 11, 2016 [Page 13] Internet-Draft NETCONF/RESTCONF Server Config Models October 2015 ca.example.com WmdsK2gyTTg3QmtGMjhWbW1CdFFVaWc3OEgrRkYyRTFwdSt4ZVRJbVFFM lLQllsdWpOcjFTMnRLR05EMUc2OVJpK2FWNGw2NTdZNCtadVJMZgpRYjk zSFNwSDdwVXBCYnA4dmtNanFtZjJma3RqZHBxeFppUUtTbndWZTF2Zwot NGcEk3UE90cnNFVjRwTUNBd0VBQWFPQ0FSSXdnZ0VPCk1CMEdBMVVkRGd VEJiZ0JTWEdlbUEKMnhpRHVOTVkvVHFLNWd4cFJBZ1ZOYUU0cERZd05ER V6QVJCZ05WQkFNVENrTlNUQ0JKYzNOMVpYS0NDUUNVRHBNSll6UG8zREF NQmdOVkhSTUJBZjhFCkFqQUFNQTRHQTFVZER3RUIvd1FFQXdJSGdEQnBC Z05WSFI4RVlqQmdNRjZnSXFBZ2hoNW9kSFJ3T2k4dlpYaGgKYlhCc1pTN WpiMjB2WlhoaGJYQnNaUzVqY215aU9LUTJNRFF4Q3pBSkJnTlZCQVlUQW QmdOVkJBWVRBbFZUTVJBd0RnWURWUVFLRXdkbAplR0Z0Y0d4bE1RNHdEQ MkF6a3hqUDlVQWtHR0dvS1U1eUc1SVR0Wm0vK3B0R2FieXVDMjBRd2kvZ 25PZnpZNEhONApXY0pTaUpZK2xtYWs3RTRORUZXZS9RdGp4NUlXZmdvN2 RJSUJQFRStS0Cg== common-ca-certs Trusted certificates to authenticate common HTTPS servers. These certificates are similar to those that might be shipped with a web browser. ex-certificate-authority NGcEk3UE90cnNFVjRwTUNBd0VBQWFPQ0FSSXdnZ0VPCk1CMEdBMVVkRGd VEJiZ0JTWEdlbUEKMnhpRHVOTVkvVHFLNWd4cFJBZ1ZOYUU0cERZd05ER V6QVJCZ05WQkFNVENrTlNUQ0JKYzNOMVpYS0NDUUNVRHBNSll6UG8zREF Z05WSFI4RVlqQmdNRjZnSXFBZ2hoNW9kSFJ3T2k4dlpYaGgKYlhCc1pTN QmdOVkJBWVRBbFZUTVJBd0RnWURWUVFLRXdkbAplR0Z0Y0d4bE1RNHdEQ MkF6a3hqUDlVQWtHR0dvS1U1eUc1SVR0Wm0vK3B0R2FieXVDMjBRd2kvZ NQmdOVkhSTUJBZjhFCkFqQUFNQTRHQTFVZER3RUIvd1FFQXdJSGdEQnBC WmdsK2gyTTg3QmtGMjhWbW1CdFFVaWc3OEgrRkYyRTFwdSt4ZVRJbVFFM lLQllsdWpOcjFTMnRLR05EMUc2OVJpK2FWNGw2NTdZNCtadVJMZgpRYjk zSFNwSDdwVXBCYnA4dmtNanFtZjJma3RqZHBxeFppUUtTbndWZTF2Zwot 25PZnpZNEhONApXY0pTaUpZK2xtYWs3RTRORUZXZS9RdGp4NUlXZmdvN2 WpiMjB2WlhoaGJYQnNaUzVqY215aU9L= Watsen & Schoenwaelder Expires April 11, 2016 [Page 14] Internet-Draft NETCONF/RESTCONF Server Config Models October 2015 4.1.3. YANG Model file "ietf-keychain@2015-10-09.yang" module ietf-keychain { yang-version 1.1; namespace "urn:ietf:params:xml:ns:yang:ietf-keychain"; prefix "kc"; organization "IETF NETCONF (Network Configuration) Working Group"; contact "WG Web: WG List: WG Chair: Mehmet Ersue WG Chair: Mahesh Jethanandani Editor: Kent Watsen "; description "This module defines a keychain to centralize management of security credentials. Copyright (c) 2014 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 VVVV; see the RFC itself for full legal notices."; revision "2015-10-09" { Watsen & Schoenwaelder Expires April 11, 2016 [Page 15] Internet-Draft NETCONF/RESTCONF Server Config Models October 2015 description "Initial version"; reference "RFC VVVV: NETCONF Server and RESTCONF Server Configuration Models"; } container keychain { description "A list of private-keys and their associated certificates, as well as lists of trusted certificates for client certificate authentication. RPCs are provided to generate a new private key and to generate a certificate signing requests."; container private-keys { description "A list of private key maintained by the keychain."; list private-key { key name; description "A private key."; leaf name { type string; description "An arbitrary name for the private key."; } leaf algorithm { type enumeration { enum rsa { description "TBD"; } enum dsa { description "TBD"; } enum secp192r1 { description "TBD"; } enum sect163k1 { description "TBD"; } enum sect163r2 { description "TBD"; } enum secp224r1 { description "TBD"; } enum sect233k1 { description "TBD"; } enum sect233r1 { description "TBD"; } enum secp256r1 { description "TBD"; } enum sect283k1 { description "TBD"; } enum sect283r1 { description "TBD"; } enum secp384r1 { description "TBD"; } enum sect409k1 { description "TBD"; } enum sect409r1 { description "TBD"; } enum secp521r1 { description "TBD"; } enum sect571k1 { description "TBD"; } enum sect571r1 { description "TBD"; } } config false; description Watsen & Schoenwaelder Expires April 11, 2016 [Page 16] Internet-Draft NETCONF/RESTCONF Server Config Models October 2015 "The algorithm used by the private key."; } leaf key-length { type uint32; config false; description "The key-length used by the private key."; } leaf public-key { type string; config false; description "The public-key matching the private key."; } container certificates { list certificate { key name; description "A certificate for this public key."; leaf name { type string; description "An arbitrary name for the certificate."; } leaf chain { type binary; description "The certificate itself, as well as an ordered sequence of intermediate certificates leading to a trust anchor, as specified by RFC 5246, Section 7.4.2."; reference "RFC 5246: The Transport Layer Security (TLS) Protocol Version 1.2"; } } description "A list of certificates for this public key."; } action generate-certificate-signing-request { description "Generates a certificate signing request structure for the associated private key using the passed subject and attribute values."; input { leaf subject { type binary; mandatory true; Watsen & Schoenwaelder Expires April 11, 2016 [Page 17] Internet-Draft NETCONF/RESTCONF Server Config Models October 2015 description "The distinguished name of the certificate subject (the entity whose public key is to be certified). This field is encoded the same as the 'subject' field in the CertificationRequestInfo type defined in RFC 2986, Section 4.1."; reference "RFC 2986: PKCS #10: Certification Request Syntax Specification Version 1.7"; } leaf attributes { type binary; description "A collection of attributes providing additional information about the subject of the certificate. This field is encoded the same as the 'attributes' field in the CertificationRequestInfo type defined in RFC 2986, Section 4.1."; reference "RFC 2986: PKCS #10: Certification Request Syntax Specification Version 1.7"; } } output { leaf certificate-signing-request { type binary; mandatory true; description "The certificate signing request to be signed by a certificate authority. This field is encoded as the CertificationRequest type defined in RFC 2986, Section 4.2."; reference "RFC 2986: PKCS #10: Certification Request Syntax Specification Version 1.7"; } } } } action generate-private-key { description "Generates a private key using the specified algorithm and key length."; input { leaf name { type string; mandatory true; description Watsen & Schoenwaelder Expires April 11, 2016 [Page 18] Internet-Draft NETCONF/RESTCONF Server Config Models October 2015 "The name this private-key should have when listed in /keychain/private-keys. As such, the passed value must not match any existing 'name' value."; } leaf algorithm { type enumeration { enum rsa { description "TBD"; } enum dsa { description "TBD"; } enum secp192r1 { description "TBD"; } enum sect163k1 { description "TBD"; } enum sect163r2 { description "TBD"; } enum secp224r1 { description "TBD"; } enum sect233k1 { description "TBD"; } enum sect233r1 { description "TBD"; } enum secp256r1 { description "TBD"; } enum sect283k1 { description "TBD"; } enum sect283r1 { description "TBD"; } enum secp384r1 { description "TBD"; } enum sect409k1 { description "TBD"; } enum sect409r1 { description "TBD"; } enum secp521r1 { description "TBD"; } enum sect571k1 { description "TBD"; } enum sect571r1 { description "TBD"; } } mandatory true; description "The algorithm to be used."; } leaf key-length { type uint32; description "For algorithms that need a key length specified when generating the key."; } } } } list trusted-certificates { key name; description "A list of lists of trusted certificates."; leaf name { type string; description "An arbitrary name for this list of trusted certificates."; } Watsen & Schoenwaelder Expires April 11, 2016 [Page 19] Internet-Draft NETCONF/RESTCONF Server Config Models October 2015 leaf description { type string; description "An arbitrary description for this list of trusted certificates."; } list trusted-certificate { key name; description "A list of trusted certificates for a specific use."; leaf name { type string; description "An arbitrary name for this trusted certificate."; } leaf certificate { type binary; 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"; } } } } } 4.2. The SSH Server Model The SSH Server model presented in this section presents two YANG groupings, one for a server that opens a socket to accept TCP connections on, and another for a server that has had the TCP connection opened for it already (e.g., inetd). The SSH Server model (like the TLS Server model presented below) is provided as a grouping so that it can be used in different contexts. For instance, the NETCONF Server model presented in Section 4.4 uses one grouping to configure a NETCONF server listening for connections and the other grouping to configure NETCONF call home. A shared characteristic between both groupings is the ability to configure which host key is presented to clients, the private key for Watsen & Schoenwaelder Expires April 11, 2016 [Page 20] Internet-Draft NETCONF/RESTCONF Server Config Models October 2015 which is held in the keychain configuration presented before. Another shared characteristic is the ability to configure which trusted CA or client certificates the server should be used to authenticate clients when using X.509 based client certificates [RFC6187]. 4.2.1. Tree Diagram The following tree diagram represents the data model for the grouping used to configure an SSH server to listen for TCP connections. The tree diagram for the other grouping is not provided, but it is the same except without the "address" and "port" fields. NOTE: the diagram below shows "listening-ssh-server" as a YANG container (not a grouping). This temporary container was created only to enable the `pyang` tool to output the tree diagram, as groupings by themselves have no protocol accessible nodes, and hence `pyang` would output an empty tree diagram. module: ietf-ssh-server +--rw listening-ssh-server +--rw address? inet:ip-address +--rw port inet:port-number +--rw host-keys | +--rw host-key* [name] | +--rw name string | +--rw (type)? | +--:(public-key) | | +--rw public-key? -> /kc:keychain/private-keys/pri vate-key/name | +--:(certificate) | +--rw certificate? -> /kc:keychain/private-keys/pri vate-key/certificates/certificate/name {ssh-x509-certs}? +--rw client-cert-auth {ssh-x509-certs}? +--rw trusted-ca-certs? -> /kc:keychain/trusted-certific ates/name +--rw trusted-client-certs? -> /kc:keychain/trusted-certific ates/name 4.2.2. Example Usage This section shows how it would appear if the temporary listening- ssh-server container just mentioned above were populated with some data. This example is consistent with the examples presented earlier in this document. Watsen & Schoenwaelder Expires April 11, 2016 [Page 21] Internet-Draft NETCONF/RESTCONF Server Config Models October 2015 830 deployment-specific-certificate ex-key-sect571r1-cert deployment-specific-ca-certs explicitly-trusted-client-certs 4.2.3. YANG Model file "ietf-ssh-server@2015-10-09.yang" module ietf-ssh-server { yang-version 1.1; namespace "urn:ietf:params:xml:ns:yang:ietf-ssh-server"; prefix "ts"; import ietf-inet-types { // RFC 6991 prefix inet; } import ietf-keychain { prefix kc; // RFC VVVV revision-date 2015-10-09; } organization "IETF NETCONF (Network Configuration) Working Group"; contact "WG Web: WG List: WG Chair: Mehmet Ersue Watsen & Schoenwaelder Expires April 11, 2016 [Page 22] Internet-Draft NETCONF/RESTCONF Server Config Models October 2015 WG Chair: Mahesh Jethanandani Editor: Kent Watsen "; description "This module defines a reusable grouping for a SSH server that can be used as a basis for specific SSH server instances. Copyright (c) 2014 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 VVVV; see the RFC itself for full legal notices."; revision "2015-10-09" { description "Initial version"; reference "RFC VVVV: NETCONF Server and RESTCONF Server Configuration Models"; } // features feature ssh-x509-certs { description "The ssh-x509-certs feature indicates that the NETCONF server supports RFC 6187"; reference "RFC 6187: X.509v3 Certificates for Secure Shell Authentication"; } // grouping grouping non-listening-ssh-server-grouping { description "A reusable grouping for a SSH server that can be used as a basis for specific SSH server instances."; Watsen & Schoenwaelder Expires April 11, 2016 [Page 23] Internet-Draft NETCONF/RESTCONF Server Config Models October 2015 container host-keys { description "The list of host-keys the SSH server will present when establishing a SSH connection."; list host-key { key name; min-elements 1; ordered-by user; description "An ordered list of host keys the SSH server advertises when sending its ??? message."; reference "RFC ????: ..."; leaf name { type string; mandatory true; description "An arbitrary name for this host-key"; } choice type { description "The type of host key being specified"; leaf public-key { type leafref { path "/kc:keychain/kc:private-keys/kc:private-key/" + "kc:name"; } description "The name of a private-key in the keychain."; } leaf certificate { if-feature ssh-x509-certs; type leafref { path "/kc:keychain/kc:private-keys/kc:private-key/" + "kc:certificates/kc:certificate/kc:name"; } description "The name of a certificate in the keychain."; } } } } container client-cert-auth { if-feature ssh-x509-certs; description "A reference to a list of trusted certificate authority (CA) certificates and a reference to a list of trusted client Watsen & Schoenwaelder Expires April 11, 2016 [Page 24] Internet-Draft NETCONF/RESTCONF Server Config Models October 2015 certificates."; leaf trusted-ca-certs { type leafref { path "/kc:keychain/kc:trusted-certificates/kc:name"; } description "A reference to a list of certificate authority (CA) certificates used by the SSH server to authenticate SSH client certificates."; } leaf trusted-client-certs { type leafref { path "/kc:keychain/kc:trusted-certificates/kc:name"; } description "A reference to a list of client certificates used by the SSH server to authenticate SSH client certificates. A clients certificate is authenticated if it is an exact match to a configured trusted client certificate."; } } } grouping listening-ssh-server-grouping { description "A reusable grouping for a SSH server that can be used as a basis for specific SSH server instances."; leaf address { type inet:ip-address; description "The IP address of the interface to listen on. The SSH server will listen on all interfaces if no value is specified."; } leaf port { type inet:port-number; mandatory true; // will a default augmented in work? description "The local port number on this interface the SSH server listens on."; } uses non-listening-ssh-server-grouping; } // RFC Editor: please remove the following container block // when publishing this document as an RFC. Watsen & Schoenwaelder Expires April 11, 2016 [Page 25] Internet-Draft NETCONF/RESTCONF Server Config Models October 2015 container listening-ssh-server { description "This container is only present to enable `pyang` tree diagram output, as a grouping by itself has no protocol accessible nodes to output."; uses listening-ssh-server-grouping; } } 4.3. The TLS Server Model The TLS Server model presented in this section presents two YANG groupings, one for a server that opens a socket to accept TCP connections on, and another for a server that has had the TCP connection opened for it already (e.g., inetd). The TLS Server model (like the SSH Server model presented above) is provided as a grouping so that it can be used in different contexts. For instance, the NETCONF Server model presented in Section 4.4 uses one grouping to configure a NETCONF server listening for connections and the other grouping to configure NETCONF call home. A shared characteristic between both groupings is the ability to configure which server certificate is presented to clients, the private key for which is held in the keychain model presented in Section 4.1. Another shared characteristic is the ability to configure which trusted CA or client certificates the server should be used to authenticate clients. 4.3.1. Tree Diagram The following tree diagram represents the data model for the grouping used to configure an TLS server to listen for TCP connections. The tree diagram for the other grouping is not provided, but it is the same except without the "address" and "port" fields. NOTE: the diagram below shows "listening-ssh-server" as a YANG container (not a grouping). This temporary container was created only to enable the `pyang` tool to output the tree diagram, as groupings by themselves have no protocol accessible nodes, and hence `pyang` would output an empty tree diagram. Watsen & Schoenwaelder Expires April 11, 2016 [Page 26] Internet-Draft NETCONF/RESTCONF Server Config Models October 2015 module: ietf-tls-server +--rw listening-tls-server +--rw address? inet:ip-address +--rw port inet:port-number +--rw certificates | +--rw certificate* [name] | +--rw name -> /kc:keychain/private-keys/private-key/cert ificates/certificate/name +--rw client-auth +--rw trusted-ca-certs? -> /kc:keychain/trusted-certific ates/name +--rw trusted-client-certs? -> /kc:keychain/trusted-certific ates/name 4.3.2. Example Usage 6513 ex-key-sect571r1-cert deployment-specific-ca-certs explicitly-trusted-client-certs 4.3.3. YANG Model file "ietf-tls-server@2015-10-09.yang" module ietf-tls-server { yang-version 1.1; namespace "urn:ietf:params:xml:ns:yang:ietf-tls-server"; prefix "ts"; import ietf-inet-types { // RFC 6991 prefix inet; } Watsen & Schoenwaelder Expires April 11, 2016 [Page 27] Internet-Draft NETCONF/RESTCONF Server Config Models October 2015 import ietf-keychain { prefix kc; // RFC VVVV revision-date 2015-10-09; } organization "IETF NETCONF (Network Configuration) Working Group"; contact "WG Web: WG List: WG Chair: Mehmet Ersue WG Chair: Mahesh Jethanandani Editor: Kent Watsen "; description "This module defines a reusable grouping for a TLS server that can be used as a basis for specific TLS server instances. Copyright (c) 2014 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 VVVV; see the RFC itself for full legal notices."; revision "2015-10-09" { description "Initial version"; reference "RFC VVVV: NETCONF Server and RESTCONF Server Configuration Models"; } Watsen & Schoenwaelder Expires April 11, 2016 [Page 28] Internet-Draft NETCONF/RESTCONF Server Config Models October 2015 // grouping grouping non-listening-tls-server-grouping { description "A reusable grouping for a TLS server that can be used as a basis for specific TLS server instances."; container certificates { description "The list of certificates the TLS server will present when establishing a TLS connection."; list certificate { key name; min-elements 1; description "An unordered list of certificates the TLS server can pick from when sending its Server Certificate message."; reference "RFC 5246: The TLS Protocol, Section 7.4.2"; leaf name { type leafref { path "/kc:keychain/kc:private-keys/kc:private-key/" + "kc:certificates/kc:certificate/kc:name"; } description "The name of the certificate in the keychain."; } } } container client-auth { description "A reference to a list of trusted certificate authority (CA) certificates and a reference to a list of trusted client certificates."; leaf trusted-ca-certs { type leafref { path "/kc:keychain/kc:trusted-certificates/kc:name"; } description "A reference to a list of certificate authority (CA) certificates used by the TLS server to authenticate TLS client certificates."; } leaf trusted-client-certs { type leafref { path "/kc:keychain/kc:trusted-certificates/kc:name"; } description Watsen & Schoenwaelder Expires April 11, 2016 [Page 29] Internet-Draft NETCONF/RESTCONF Server Config Models October 2015 "A reference to a list of client certificates used by the TLS server to authenticate TLS client certificates. A clients certificate is authenticated if it is an exact match to a configured trusted client certificate."; } } } grouping listening-tls-server-grouping { description "A reusable grouping for a TLS server that can be used as a basis for specific TLS server instances."; leaf address { type inet:ip-address; description "The IP address of the interface to listen on. The TLS server will listen on all interfaces if no value is specified."; } leaf port { type inet:port-number; mandatory true; // will a default augmented in work? description "The local port number on this interface the TLTLS server listens on."; } uses non-listening-tls-server-grouping; } // RFC Editor: please remove the following container block // when publishing this document as an RFC. container listening-tls-server { description "This container is only present to enable `pyang` tree diagram output, as a grouping by itself has no protocol accessible nodes to output."; uses listening-tls-server-grouping; } } Watsen & Schoenwaelder Expires April 11, 2016 [Page 30] Internet-Draft NETCONF/RESTCONF Server Config Models October 2015 4.4. The NETCONF Server Model The NETCONF Server model presented in this section supports servers both listening for connections to accept as well as initiating call- home connections. This model also supports both the SSH and TLS transport protocols, using the SSH Server and TLS Server groupings presented in Section 4.2 and Section 4.3 respectively. All private keys and trusted certificates are held in the keychain model presented in Section 4.1. YANG feature statements are used to enable implementations to advertise which parts of the model the NETCONF server supports. 4.4.1. Tree Diagram The following tree diagram uses line-wrapping in order to comply with xml2rfc validation. This is annoying as I find that drafts (even txt drafts) look just fine with long lines - maybe xml2rfc should remove this warning? - or pyang could have an option to suppress printing leafref paths? module: ietf-netconf-server +--rw netconf-server +--rw session-options | +--rw hello-timeout? uint16 +--rw listen {(ssh-listen or tls-listen)}? | +--rw max-sessions? uint16 | +--rw idle-timeout? uint16 | +--rw endpoint* [name] | +--rw name string | +--rw (transport) | +--:(ssh) {ssh-listen}? | | +--rw ssh | | +--rw address? inet:ip-address | | +--rw port inet:port-number | | +--rw host-keys | | | +--rw host-key* [name] | | | +--rw name string | | | +--rw (type)? | | | +--:(public-key) | | | | +--rw public-key? -> /kc:keychain/p rivate-keys/private-key/name | | | +--:(certificate) | | | +--rw certificate? -> /kc:keychain/p rivate-keys/private-key/certificates/certificate/name {ssh-x509-certs}? | | +--rw client-cert-auth {ssh-x509-certs}? | | +--rw trusted-ca-certs? -> /kc:keychain/t Watsen & Schoenwaelder Expires April 11, 2016 [Page 31] Internet-Draft NETCONF/RESTCONF Server Config Models October 2015 rusted-certificates/name | | +--rw trusted-client-certs? -> /kc:keychain/t rusted-certificates/name | +--:(tls) {tls-listen}? | +--rw tls | +--rw address? inet:ip-address | +--rw port inet:port-number | +--rw certificates | | +--rw certificate* [name] | | +--rw name -> /kc:keychain/private-keys/p rivate-key/certificates/certificate/name | +--rw client-auth | +--rw trusted-ca-certs? -> /kc:keychain/t rusted-certificates/name | +--rw trusted-client-certs? -> /kc:keychain/t rusted-certificates/name | +--rw cert-maps | +--rw cert-to-name* [id] | +--rw id uint32 | +--rw fingerprint x509c2n:tls-fingerpr int | +--rw map-type identityref | +--rw name string +--rw call-home {(ssh-call-home or tls-call-home)}? +--rw netconf-client* [name] +--rw name string +--rw (transport) | +--:(ssh) {ssh-call-home}? | | +--rw ssh | | +--rw endpoints | | | +--rw endpoint* [name] | | | +--rw name string | | | +--rw address inet:host | | | +--rw port? inet:port-number | | +--rw host-keys | | | +--rw host-key* [name] | | | +--rw name string | | | +--rw (type)? | | | +--:(public-key) | | | | +--rw public-key? -> /kc:keychain/p rivate-keys/private-key/name | | | +--:(certificate) | | | +--rw certificate? -> /kc:keychain/p rivate-keys/private-key/certificates/certificate/name {ssh-x509-certs}? | | +--rw client-cert-auth {ssh-x509-certs}? | | +--rw trusted-ca-certs? -> /kc:keychain/t rusted-certificates/name | | +--rw trusted-client-certs? -> /kc:keychain/t Watsen & Schoenwaelder Expires April 11, 2016 [Page 32] Internet-Draft NETCONF/RESTCONF Server Config Models October 2015 rusted-certificates/name | +--:(tls) {tls-call-home}? | +--rw tls | +--rw endpoints | | +--rw endpoint* [name] | | +--rw name string | | +--rw address inet:host | | +--rw port? inet:port-number | +--rw certificates | | +--rw certificate* [name] | | +--rw name -> /kc:keychain/private-keys/p rivate-key/certificates/certificate/name | +--rw client-auth | +--rw trusted-ca-certs? -> /kc:keychain/t rusted-certificates/name | +--rw trusted-client-certs? -> /kc:keychain/t rusted-certificates/name | +--rw cert-maps | +--rw cert-to-name* [id] | +--rw id uint32 | +--rw fingerprint x509c2n:tls-fingerpr int | +--rw map-type identityref | +--rw name string +--rw connection-type | +--rw (connection-type)? | +--:(persistent-connection) | | +--rw persistent! | | +--rw idle-timeout? uint32 | | +--rw keep-alives | | +--rw max-wait? uint16 | | +--rw max-attempts? uint8 | +--:(periodic-connection) | +--rw periodic! | +--rw idle-timeout? uint16 | +--rw reconnect_timeout? uint16 +--rw reconnect-strategy +--rw start-with? enumeration +--rw max-attempts? uint8 4.4.2. Example Usage Configuring a NETCONF Server to listen for NETCONF client connections using both the SSH and TLS transport protocols, as well as configuring call-home to two NETCONF clients, one using SSH and the other using TLS. Watsen & Schoenwaelder Expires April 11, 2016 [Page 33] Internet-Draft NETCONF/RESTCONF Server Config Models October 2015 This example is consistent with other examples presented in this document. netconf/ssh
11.22.33.44
my-rsa-key TPM key deployment-specific-ca-certs explicitly-trusted-client-certs
netconf/tls
11.22.33.44
ex-key-sect571r1-cert deployment-specific-ca-certs explicitly-trusted-client-certs Watsen & Schoenwaelder Expires April 11, 2016 [Page 34] Internet-Draft NETCONF/RESTCONF Server Config Models October 2015 1 11:0A:05:11:00 x509c2n:san-any 2 B3:4F:A1:8C:54 x509c2n:specified scooby-doo
config-mgr east-data-center
11.22.33.44
west-data-center
55.66.77.88
TPM key deployment-specific-ca-certs explicitly-trusted-client-certs
Watsen & Schoenwaelder Expires April 11, 2016 [Page 35] Internet-Draft NETCONF/RESTCONF Server Config Models October 2015 300 60 last-connected 3
event-correlator east-data-center
22.33.44.55
west-data-center
33.44.55.66
ex-key-sect571r1-cert deployment-specific-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 Watsen & Schoenwaelder Expires April 11, 2016 [Page 36] Internet-Draft NETCONF/RESTCONF Server Config Models October 2015
300 30 3 first-listed 3
4.4.3. YANG Model This YANG module imports YANG types from [RFC6991] and [RFC7407]. file "ietf-netconf-server@2015-10-09.yang" module ietf-netconf-server { yang-version 1.1; namespace "urn:ietf:params:xml:ns:yang:ietf-netconf-server"; prefix "ncserver"; import ietf-inet-types { // RFC 6991 prefix inet; } import ietf-x509-cert-to-name { // RFC 7407 prefix x509c2n; } import ietf-ssh-server { // RFC VVVV prefix ss; revision-date 2015-10-09; } import ietf-tls-server { // RFC VVVV prefix ts; revision-date 2015-10-09; } Watsen & Schoenwaelder Expires April 11, 2016 [Page 37] Internet-Draft NETCONF/RESTCONF Server Config Models October 2015 organization "IETF NETCONF (Network Configuration) Working Group"; contact "WG Web: WG List: WG Chair: Mehmet Ersue WG Chair: Mahesh Jethanandani Editor: Kent Watsen "; description "This module contains a collection of YANG definitions for configuring NETCONF servers. Copyright (c) 2014 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 VVVV; see the RFC itself for full legal notices."; revision "2015-10-09" { description "Initial version"; reference "RFC VVVV: NETCONF Server and RESTCONF Server Configuration Models"; } // Features feature ssh-listen { description "The ssh-listen feature indicates that the NETCONF server Watsen & Schoenwaelder Expires April 11, 2016 [Page 38] Internet-Draft NETCONF/RESTCONF Server Config Models October 2015 supports opening a port to accept NETCONF over SSH client connections."; reference "RFC 6242: Using the NETCONF Protocol over Secure Shell (SSH)"; } feature ssh-call-home { description "The ssh-call-home feature indicates that the NETCONF server supports initiating a NETCONF over SSH call home connection to NETCONF clients."; reference "RFC YYYY: NETCONF Call Home and RESTCONF Call Home"; } feature tls-listen { description "The tls-listen feature indicates that the NETCONF server supports opening a port to accept NETCONF over TLS client connections."; reference "RFC 5539: Using the NETCONF Protocol over Transport Layer Security (TLS) with Mutual X.509 Authentication"; } feature tls-call-home { description "The tls-call-home feature indicates that the NETCONF server supports initiating a NETCONF over TLS call home connection to NETCONF clients."; reference "RFC YYYY: NETCONF Call Home and RESTCONF Call Home"; } feature ssh-x509-certs { description "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 Watsen & Schoenwaelder Expires April 11, 2016 [Page 39] Internet-Draft NETCONF/RESTCONF Server Config Models October 2015 "Top-level container for NETCONF server configuration."; container session-options { // SHOULD WE REMOVE THIS ALTOGETHER? description "NETCONF session options, independent of transport or connection strategy."; leaf hello-timeout { type uint16; units "seconds"; default 600; description "Specifies the maximum number of seconds that a SSH/TLS connection may wait for a hello message to be received. A connection will be dropped if no hello message is received before this number of seconds elapses. If set to zero, then the server will wait forever for a hello message."; } } container listen { if-feature "(ssh-listen or tls-listen)"; description "Configures listen behavior"; leaf max-sessions { type uint16; 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."; } leaf idle-timeout { type uint16; units "seconds"; default 3600; // one hour description "Specifies the maximum number of seconds that a NETCONF session may remain idle. A NETCONF 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; description "List of endpoints to listen for NETCONF connections on."; Watsen & Schoenwaelder Expires April 11, 2016 [Page 40] Internet-Draft NETCONF/RESTCONF Server Config Models October 2015 leaf name { type string; description "An arbitrary name for the NETCONF listen endpoint."; } choice transport { mandatory true; description "Selects between available transports."; case ssh { if-feature ssh-listen; container ssh { description "SSH-specific listening configuration for inbound connections."; uses ss:listening-ssh-server-grouping { refine port { default 830; } } } } case tls { if-feature tls-listen; container tls { description "TLS-specific listening configuration for inbound connections."; uses ts:listening-tls-server-grouping { refine port { default 6513; } augment "client-auth" { description "Augments in the cert-to-name structure."; uses cert-maps-grouping; } } } } } } } container call-home { if-feature "(ssh-call-home or tls-call-home)"; description "Configures call-home behavior"; Watsen & Schoenwaelder Expires April 11, 2016 [Page 41] Internet-Draft NETCONF/RESTCONF Server Config Models October 2015 list netconf-client { key name; description "List of NETCONF clients the NETCONF server is to initiate call-home connections to."; leaf name { type string; description "An arbitrary name for the remote NETCONF client."; } choice transport { mandatory true; description "Selects between available transports."; case ssh { if-feature ssh-call-home; container ssh { description "Specifies SSH-specific call-home transport configuration."; uses endpoints-container { refine endpoints/endpoint/port { default 7777; } } uses ss:non-listening-ssh-server-grouping; } } case tls { if-feature tls-call-home; container tls { description "Specifies TLS-specific call-home transport configuration."; uses endpoints-container { refine endpoints/endpoint/port { default 8888; } } uses ts:non-listening-tls-server-grouping { augment "client-auth" { description "Augments in the cert-to-name structure."; uses cert-maps-grouping; } } } } Watsen & Schoenwaelder Expires April 11, 2016 [Page 42] Internet-Draft NETCONF/RESTCONF Server Config Models October 2015 } container connection-type { description "Indicates the kind of connection to use."; choice connection-type { description "Selects between available connection types."; case persistent-connection { container persistent { presence true; description "Maintain a persistent connection to the NETCONF client. If the connection goes down, immediately start trying to reconnect to it, using the reconnection strategy. This connection type minimizes any NETCONF client to NETCONF server data-transfer delay, albeit at the expense of holding resources longer."; leaf idle-timeout { type uint32; units "seconds"; default 86400; // one day; description "Specifies the maximum number of seconds that a a NETCONF session may remain idle. A NETCONF 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."; } container keep-alives { description "Configures the keep-alive policy, to proactively test the aliveness of the SSH/TLS client. An unresponsive SSH/TLS client will be dropped after approximately max-attempts * max-wait seconds."; reference "RFC YYYY: NETCONF Call Home and RESTCONF Call Home, Section 3.1, item S6"; leaf max-wait { type uint16 { range "1..max"; } units seconds; default 30; Watsen & Schoenwaelder Expires April 11, 2016 [Page 43] Internet-Draft NETCONF/RESTCONF Server Config Models October 2015 description "Sets the amount of time in seconds after which if no data has been received from the SSH/TLS client, a SSH/TLS-level message will be sent to test the aliveness of the SSH/TLS client."; } leaf max-attempts { type uint8; default 3; description "Sets the number of maximum number of sequential keep-alive messages that can fail to obtain a response from the SSH/TLS client before assuming the SSH/TLS client is no longer alive."; } } } } case periodic-connection { container periodic { presence true; description "Periodically connect to the NETCONF client, so that the NETCONF client may deliver messages pending for the NETCONF server. The NETCONF client is expected to close the connection when it is ready to release it, thus starting the NETCONF server's timer until next connection."; leaf idle-timeout { type uint16; units "seconds"; default 300; // five minutes description "Specifies the maximum number of seconds that a a NETCONF session may remain idle. A NETCONF 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."; } leaf reconnect_timeout { type uint16 { range "1..max"; } units minutes; default 60; Watsen & Schoenwaelder Expires April 11, 2016 [Page 44] Internet-Draft NETCONF/RESTCONF Server Config Models October 2015 description "Sets the maximum amount of unconnected time the NETCONF server will wait before re-establishing a connection to the NETCONF client. The NETCONF server may initiate a connection before this time if desired (e.g., to deliver an event notification message)."; } } } } } container reconnect-strategy { description "The reconnection strategy guides how a NETCONF server reconnects to a NETCONF client, after discovering its connection to the client has dropped. The NETCONF 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. NETCONF servers SHOULD be able to remember the last endpoint connected to across reboots."; } } default first-listed; description "Specifies which of the NETCONF client's endpoints the NETCONF server should start with when trying to connect to the NETCONF client."; } leaf max-attempts { type uint8 { range "1..max"; } default 3; Watsen & Schoenwaelder Expires April 11, 2016 [Page 45] Internet-Draft NETCONF/RESTCONF Server Config Models October 2015 description "Specifies the number times the NETCONF server tries to connect to a specific endpoint before moving on to the next endpoint in the list (round robin)."; } } } } } grouping cert-maps-grouping { description "A grouping that defines a container around the cert-to-name structure defined in RFC 7407."; container cert-maps { uses x509c2n:cert-to-name; description "The cert-maps container is used by a TLS-based 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."; reference "RFC WWWW: NETCONF over TLS, Section 7"; } } grouping endpoints-container { description "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."; leaf name { type string; description "An arbitrary name for this endpoint."; Watsen & Schoenwaelder Expires April 11, 2016 [Page 46] Internet-Draft NETCONF/RESTCONF Server Config Models October 2015 } leaf address { type inet:host; mandatory true; description "The IP address or hostname of the endpoint. If a hostname is configured and the DNS resolution results in more than one IP address, the NETCONF server will process the IP addresses as if they had been explicitly configured in place of the hostname."; } leaf port { type inet:port-number; description "The IP port for this endpoint. The NETCONF server will use the IANA-assigned well-known port if no value is specified."; } } } } } 4.5. The RESTCONF Server Model The RESTCONF Server model presented in this section supports servers both listening for connections to accept as well as initiating call- home connections. This model supports the TLS transport only, as RESTCONF only supports HTTPS, using the TLS Server groupings presented in Section 4.3. All private keys and trusted certificates are held in the keychain model presented in Section 4.1. YANG feature statements are used to enable implementations to advertise which parts of the model the RESTCONF server supports. 4.5.1. Tree Diagram The following tree diagram uses line-wrapping in order to comply with xml2rfc validation. This is annoying as I find that drafts (even txt drafts) look just fine with long lines - maybe xml2rfc should remove this warning? - or pyang could have an option to suppress printing leafref paths? module: ietf-restconf-server +--rw restconf-server Watsen & Schoenwaelder Expires April 11, 2016 [Page 47] Internet-Draft NETCONF/RESTCONF Server Config Models October 2015 +--rw listen {tls-listen}? | +--rw max-sessions? uint16 | +--rw endpoint* [name] | +--rw name string | +--rw (transport) | +--:(tls) {tls-listen}? | +--rw tls | +--rw address? inet:ip-address | +--rw port inet:port-number | +--rw certificates | | +--rw certificate* [name] | | +--rw name -> /kc:keychain/private-keys/p rivate-key/certificates/certificate/name | +--rw client-auth | +--rw trusted-ca-certs? -> /kc:keychain/t rusted-certificates/name | +--rw trusted-client-certs? -> /kc:keychain/t rusted-certificates/name | +--rw cert-maps | +--rw cert-to-name* [id] | +--rw id uint32 | +--rw fingerprint x509c2n:tls-fingerpr int | +--rw map-type identityref | +--rw name string +--rw call-home {tls-call-home}? +--rw restconf-client* [name] +--rw name string +--rw (transport) | +--:(tls) {tls-call-home}? | +--rw tls | +--rw endpoints | | +--rw endpoint* [name] | | +--rw name string | | +--rw address inet:host | | +--rw port? inet:port-number | +--rw certificates | | +--rw certificate* [name] | | +--rw name -> /kc:keychain/private-keys/p rivate-key/certificates/certificate/name | +--rw client-auth | +--rw trusted-ca-certs? -> /kc:keychain/t rusted-certificates/name | +--rw trusted-client-certs? -> /kc:keychain/t rusted-certificates/name | +--rw cert-maps | +--rw cert-to-name* [id] | +--rw id uint32 Watsen & Schoenwaelder Expires April 11, 2016 [Page 48] Internet-Draft NETCONF/RESTCONF Server Config Models October 2015 | +--rw fingerprint x509c2n:tls-fingerpr int | +--rw map-type identityref | +--rw name string +--rw connection-type | +--rw (connection-type)? | +--:(persistent-connection) | | +--rw persistent! | | +--rw keep-alives | | +--rw max-wait? uint16 | | +--rw max-attempts? uint8 | +--:(periodic-connection) | +--rw periodic! | +--rw reconnect-timeout? uint16 +--rw reconnect-strategy +--rw start-with? enumeration +--rw max-attempts? uint8 4.5.2. Example Usage 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 other examples presented in this document. netconf/tls
11.22.33.44
ex-key-sect571r1-cert deployment-specific-ca-certs explicitly-trusted-client-certs 1 Watsen & Schoenwaelder Expires April 11, 2016 [Page 49] Internet-Draft NETCONF/RESTCONF Server Config Models October 2015 11:0A:05:11:00 x509c2n:san-any 2 B3:4F:A1:8C:54 x509c2n:specified scooby-doo
config-manager east-data-center
22.33.44.55
west-data-center
33.44.55.66
ex-key-sect571r1-cert deployment-specific-ca-certs explicitly-trusted-client-certs 1 11:0A:05:11:00 x509c2n:san-any Watsen & Schoenwaelder Expires April 11, 2016 [Page 50] Internet-Draft NETCONF/RESTCONF Server Config Models October 2015 2 B3:4F:A1:8C:54 x509c2n:specified scooby-doo
300 60 last-connected 3
4.5.3. YANG Model This YANG module imports YANG types from [RFC6991] and [RFC7407]. file "ietf-restconf-server@2015-10-09.yang" module ietf-restconf-server { yang-version 1.1; namespace "urn:ietf:params:xml:ns:yang:ietf-restconf-server"; prefix "rcserver"; //import ietf-netconf-acm { // prefix nacm; // RFC 6536 //} import ietf-inet-types { // RFC 6991 prefix inet; } import ietf-x509-cert-to-name { // RFC 7407 prefix x509c2n; } import ietf-tls-server { // RFC VVVV prefix ts; revision-date 2015-10-09; Watsen & Schoenwaelder Expires April 11, 2016 [Page 51] Internet-Draft NETCONF/RESTCONF Server Config Models October 2015 } organization "IETF NETCONF (Network Configuration) Working Group"; contact "WG Web: WG List: WG Chair: Mehmet Ersue WG Chair: Mahesh Jethanandani Editor: Kent Watsen "; description "This module contains a collection of YANG definitions for configuring RESTCONF servers. Copyright (c) 2014 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 VVVV; see the RFC itself for full legal notices."; revision "2015-10-09" { description "Initial version"; reference "RFC VVVV: NETCONF Server and RESTCONF Server Configuration Models"; } // Features feature tls-listen { Watsen & Schoenwaelder Expires April 11, 2016 [Page 52] Internet-Draft NETCONF/RESTCONF Server Config Models October 2015 description "The listen feature indicates that the RESTCONF server supports opening a port to listen for incoming RESTCONF client connections."; reference "RFC XXXX: RESTCONF Protocol"; } feature tls-call-home { description "The call-home feature indicates that the RESTCONF server supports initiating connections to RESTCONF clients."; reference "RFC YYYY: NETCONF Call Home and RESTCONF Call Home"; } feature client-cert-auth { description "The client-cert-auth feature indicates that the RESTCONF server supports the ClientCertificate authentication scheme."; reference "RFC ZZZZ: Client Authentication over New TLS Connection"; } // top-level container container restconf-server { description "Top-level container for RESTCONF server configuration."; container listen { if-feature tls-listen; description "Configures listen behavior"; leaf max-sessions { type uint16; default 0; // should this be 'max'? 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 RESTCONF connections on."; leaf name { type string; Watsen & Schoenwaelder Expires April 11, 2016 [Page 53] Internet-Draft NETCONF/RESTCONF Server Config Models October 2015 description "An arbitrary name for the RESTCONF listen endpoint."; } choice transport { mandatory true; description "Selects between available transports."; case tls { if-feature tls-listen; container tls { description "TLS-specific listening configuration for inbound connections."; uses ts:listening-tls-server-grouping { refine port { default 443; } augment "client-auth" { description "Augments in the cert-to-name structure."; uses cert-maps-grouping; } } } } } } } container call-home { if-feature tls-call-home; description "Configures call-home behavior"; list restconf-client { 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 TLS and any transports augmented in."; case tls { Watsen & Schoenwaelder Expires April 11, 2016 [Page 54] Internet-Draft NETCONF/RESTCONF Server Config Models October 2015 if-feature tls-call-home; container tls { description "Specifies TLS-specific call-home transport configuration."; uses endpoints-container { refine endpoints/endpoint/port { default 9999; } } uses ts:non-listening-tls-server-grouping { augment "client-auth" { description "Augments in the cert-to-name structure."; uses cert-maps-grouping; } } } } } container connection-type { description "Indicates the RESTCONF client's preference for how the RESTCONF server's connection is maintained."; choice connection-type { description "Selects between available connection types."; case persistent-connection { container persistent { presence true; 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."; container keep-alives { description "Configures the keep-alive policy, to proactively test the aliveness of the TLS client. An unresponsive TLS client will be dropped after approximately (max-attempts * max-wait) seconds."; reference "RFC YYYY: NETCONF Call Home and RESTCONF Call Home, Watsen & Schoenwaelder Expires April 11, 2016 [Page 55] Internet-Draft NETCONF/RESTCONF Server Config Models October 2015 Section 3.1, item S6"; leaf max-wait { type uint16 { range "1..max"; } units seconds; default 30; description "Sets the amount of time in seconds after which if no data has been received from the TLS client, a TLS-level message will be sent to test the aliveness of the TLS client."; } leaf max-attempts { type uint8; default 3; description "Sets the number of sequential keep-alive messages that can fail to obtain a response from the TLS client before assuming the TLS client is no longer alive."; } } } } case periodic-connection { container periodic { presence true; description "Periodically connect to the RESTCONF client, so that the RESTCONF client may deliver messages pending for the RESTCONF server. The RESTCONF client is expected to close the connection when it is ready to release it, thus starting the RESTCONF server's timer until next connection."; leaf reconnect-timeout { type uint16 { range "1..max"; } units minutes; default 60; description "The maximum amount of unconnected time the RESTCONF server will wait before re-establishing a connection to the RESTCONF client. The RESTCONF server may initiate a connection before this time if desired (e.g., to deliver a notification)."; } Watsen & Schoenwaelder Expires April 11, 2016 [Page 56] Internet-Draft NETCONF/RESTCONF Server Config Models October 2015 } } } } container reconnect-strategy { description "The reconnection strategy guides how a RESTCONF server reconnects to an RESTCONF client, after losing a connection to it, 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 servers SHOULD be able to remember the last endpoint connected to across reboots."; } } 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)."; } } } } Watsen & Schoenwaelder Expires April 11, 2016 [Page 57] Internet-Draft NETCONF/RESTCONF Server Config Models October 2015 } grouping cert-maps-grouping { description "A grouping that defines a container around the cert-to-name structure defined in RFC 7407."; 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 XXXX: The RESTCONF Protocol"; } } grouping endpoints-container { description "This grouping is used by tls container 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."; leaf name { type string; description "An arbitrary name for this endpoint."; } leaf address { type inet:host; mandatory true; description "The IP address or hostname of the endpoint. If a hostname is configured and the DNS resolution results in more than one IP address, the RESTCONF server Watsen & Schoenwaelder Expires April 11, 2016 [Page 58] Internet-Draft NETCONF/RESTCONF Server Config Models October 2015 will process the IP addresses as if they had been explicitly configured in place of the hostname."; } leaf port { type inet:port-number; description "The IP port for this endpoint. The RESTCONF server will use the IANA-assigned well-known port if no value is specified."; } } } } } 5. Security Considerations This section needs to be filled in... 6. 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. 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. This document registers two YANG modules in the YANG Module Names registry [RFC6020]. Following the format in [RFC6020], the the following registrations are requested: Watsen & Schoenwaelder Expires April 11, 2016 [Page 59] Internet-Draft NETCONF/RESTCONF Server Config Models October 2015 name: ietf-keychain namespace: urn:ietf:params:xml:ns:yang:ietf-keychain prefix: kc reference: RFC VVVV name: ietf-ssh-server namespace: urn:ietf:params:xml:ns:yang:ietf-ssh-server prefix: ssvr reference: RFC VVVV name: ietf-tls-server namespace: urn:ietf:params:xml:ns:yang:ietf-tls-server prefix: tsvr reference: RFC VVVV name: ietf-netconf-server namespace: urn:ietf:params:xml:ns:yang:ietf-netconf-server prefix: ncsvr reference: RFC VVVV name: ietf-restconf-server namespace: urn:ietf:params:xml:ns:yang:ietf-restconf-server prefix: rcsvr reference: RFC VVVV 7. Other Considerations The YANG modules define herein do not themselves support virtual routing and forwarding (VRF). It is expected that external modules will augment in VRF designations when needed. 8. 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, Mehmet Ersue, David Lamparter, Alan Luchuk, Ladislav Lhotka, Radek Krejci, Tom Petch, Phil Shafer, and Bert Wijnen. Juergen Schoenwaelder and was partly funded by Flamingo, a Network of Excellence project (ICT-318488) supported by the European Commission under its Seventh Framework Programme. 9. References Watsen & Schoenwaelder Expires April 11, 2016 [Page 60] Internet-Draft NETCONF/RESTCONF Server Config Models October 2015 9.1. Normative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [RFC6020] Bjorklund, M., "YANG - A Data Modeling Language for the Network Configuration Protocol (NETCONF)", RFC 6020, October 2010. [RFC6187] Igoe, K. and D. Stebila, "X.509v3 Certificates for Secure Shell Authentication", RFC 6187, March 2011. [RFC6241] Enns, R., Bjorklund, M., Schoenwaelder, J., and A. Bierman, "Network Configuration Protocol (NETCONF)", RFC 6241, June 2011. [RFC6242] Wasserman, M., "Using the NETCONF Protocol over Secure Shell (SSH)", RFC 6242, June 2011. [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. [RFC7589] Badra, M., Luchuk, A., and J. Schoenwaelder, "Using the NETCONF Protocol over Transport Layer Security (TLS) with Mutual X.509 Authentication", RFC 7589, June 2015. [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. 9.2. Informative References [RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688, January 2004. Watsen & Schoenwaelder Expires April 11, 2016 [Page 61] Internet-Draft NETCONF/RESTCONF Server Config Models October 2015 Appendix A. Change Log A.1. 00 to 01 o Restructured document so it flows better o Added trusted-ca-certs and trusted-client-certs objects into the ietf-system-tls-auth module A.2. 01 to 02 o removed the "one-to-many" construct o removed "address" as a key field o removed "network-manager" terminology o moved open issues to github issues o brought TLS client auth back into model A.3. 02 to 03 o fixed tree diagrams and surrounding text A.4. 03 to 04 o reduced the number of grouping statements o removed psk-maps and associated feature statements o added ability for listen/call-home instances to specify which host-keys/certificates (of all listed) to use o clarified that last-connected should span reboots o added missing "objectives" for selecting which keys to use, authenticating client-certificates, and mapping authenticated client-certificates to usernames o clarified indirect client certificate authentication o added keep-alive configuration for listen connections o added global-level NETCONF session parameters Watsen & Schoenwaelder Expires April 11, 2016 [Page 62] Internet-Draft NETCONF/RESTCONF Server Config Models October 2015 A.5. 04 to 05 o Removed all refs to the old ietf-system-tls-auth module o Removed YANG 1.1 style if-feature statements (loss some expressiveness) o Removed the read-only (config false) lists of SSH host-keys and TLS certs o Added an if-feature around session-options container 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 A.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). A.7. 06 to 07 o Replaced "application" with "NETCONF/RESTCONF client" (issue #32). o Reverted back to YANG 1.1 if-feature statements (issue #34). Watsen & Schoenwaelder Expires April 11, 2016 [Page 63] Internet-Draft NETCONF/RESTCONF Server Config Models October 2015 o Removed import by revisions (issue #36). o Removed groupings only used once (issue #37). o Removed upper-bound on hello-timeout, idle-timeout, and max- sessions (issue #38). o Clarified that when no listen address is configured, the NETCONF/ RESTCONF server will listen on all addresses (issue #41). o Update keep-alive reference to new section in Call Home draft (issue #42). o Modified connection-type/persistent/keep-alives/interval-secs default value, removed the connection-type/periodic/linger-secs node, and also removed the reconnect-strategy/interval-secs node (issue #43). o Clarified how last-connected reconnection type should work across reboots (issue #44). o Clarified how DNS-expanded hostnames should be processed (issue #45). o Removed text on how to implement keep-alives (now in the call-home draft) and removed the keep-alive configuration for listen connections (issue #46). o Clarified text for .../periodic-connection/timeout-mins (issue #47). o Fixed description on the "trusted-ca-certs" leaf-list (issue #48). o Added optional keychain-based solution in appendix A (issue #49). o Fixed description text for the interval-secs leaf (issue #50). o moved idle-time into the listen, persistent, and periodic subtrees (issue #51). o put presence statements on containers where it makes sense (issue #53). A.8. 07 to 08 o Per WG consensus, replaced body with the keychain-based approach described in -07's Appendix. Watsen & Schoenwaelder Expires April 11, 2016 [Page 64] Internet-Draft NETCONF/RESTCONF Server Config Models October 2015 o Added a lot of introductory text, improved examples, and what not. Appendix B. Open Issues Please see: https://github.com/netconf-wg/server-model/issues. Authors' Addresses Kent Watsen Juniper Networks EMail: kwatsen@juniper.net Juergen Schoenwaelder Jacobs University Bremen EMail: j.schoenwaelder@jacobs-university.de Watsen & Schoenwaelder Expires April 11, 2016 [Page 65]