draft-ietf-netconf-server-model-03.txt   draft-ietf-netconf-server-model-04.txt 
NETCONF Working Group K. Watsen NETCONF Working Group K. Watsen
Internet-Draft Juniper Networks Internet-Draft Juniper Networks
Intended status: Standards Track J. Schoenwaelder Intended status: Standards Track J. Schoenwaelder
Expires: March 26, 2015 Jacobs University Bremen Expires: April 29, 2015 Jacobs University Bremen
September 22, 2014 October 26, 2014
NETCONF Server Configuration Model NETCONF Server Configuration Model
draft-ietf-netconf-server-model-03 draft-ietf-netconf-server-model-04
Abstract Abstract
This draft defines a NETCONF server configuration data model. This This draft defines a NETCONF server configuration data model. This
data model enables configuration of the NETCONF service itself, data model enables configuration of the NETCONF service itself,
including which transports it supports, what ports they listen on, including which transports it supports, what ports they listen on,
whether they support device-initiated connections, and associated whether call-home is supported, and associated parameters.
parameters.
Status of This Memo Status of This Memo
This Internet-Draft is submitted in full conformance with the This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79. provisions of BCP 78 and BCP 79.
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This Internet-Draft will expire on March 26, 2015. This Internet-Draft will expire on April 29, 2015.
Copyright Notice Copyright Notice
Copyright (c) 2014 IETF Trust and the persons identified as the Copyright (c) 2014 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
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Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 3 1.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 3
1.2. Tree Diagrams . . . . . . . . . . . . . . . . . . . . . . 3 1.2. Tree Diagrams . . . . . . . . . . . . . . . . . . . . . . 3
2. Objectives . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Objectives . . . . . . . . . . . . . . . . . . . . . . . . . 3
2.1. Support all NETCONF Transports . . . . . . . . . . . . . 3 2.1. Support all NETCONF transports . . . . . . . . . . . . . 3
2.2. Align Transport-Specific Configurations . . . . . . . . . 3 2.2. Enable each transport to select which keys to use . . . . 4
2.3. Support both Listening for Connections and Call Home . . 4 2.3. Support authenticating client-certificates . . . . . . . 4
2.4. For Call Home Connections . . . . . . . . . . . . . . . . 4 2.4. Support mapping authenticated client-certificates to
2.4.1. Support More than One Application . . . . . . . . . . 4 usernames . . . . . . . . . . . . . . . . . . . . . . . . 4
2.4.2. Support Applications Having More than One Server . . 4 2.5. Support both Listening for connections and Call Home . . 4
2.4.3. Support a Reconnection Strategy . . . . . . . . . . . 4 2.6. For Call Home connections . . . . . . . . . . . . . . . . 4
2.4.4. Support both Persistent and Periodic Connections . . 4 2.6.1. Support more than one application . . . . . . . . . . 4
2.4.5. Reconnection Strategy for Periodic Connections . . . 5 2.6.2. Support applications having more than one server . . 5
2.4.6. Keep-Alives for Persistent Connections . . . . . . . 5 2.6.3. Support a reconnection strategy . . . . . . . . . . . 5
2.4.7. Customizations for Periodic Connections . . . . . . . 5 2.6.4. Support both persistent and periodic connections . . 5
2.6.5. Reconnection strategy for periodic connections . . . 5
2.6.6. Keep-alives for persistent connections . . . . . . . 5
2.6.7. Customizations for periodic connections . . . . . . . 6
3. Data Model . . . . . . . . . . . . . . . . . . . . . . . . . 6 3. Data Model . . . . . . . . . . . . . . . . . . . . . . . . . 6
3.1. Overview . . . . . . . . . . . . . . . . . . . . . . . . 6 3.1. Overview . . . . . . . . . . . . . . . . . . . . . . . . 6
3.2. YANG Module . . . . . . . . . . . . . . . . . . . . . . . 8 3.1.1. The "session-options" subtree . . . . . . . . . . . . 6
4. Keep-Alives for SSH and TLS . . . . . . . . . . . . . . . . . 21 3.1.2. The "listen" subtree . . . . . . . . . . . . . . . . 6
4.1. SSH . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 3.1.3. The "call-home" subtree . . . . . . . . . . . . . . . 7
4.2. TLS . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 3.1.4. The "ssh" subtree . . . . . . . . . . . . . . . . . . 9
5. Security Considerations . . . . . . . . . . . . . . . . . . . 22 3.1.5. The "tls" subtree . . . . . . . . . . . . . . . . . . 9
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 23 3.2. YANG Module . . . . . . . . . . . . . . . . . . . . . . . 10
7. Other Considerations . . . . . . . . . . . . . . . . . . . . 23 4. Implementation strategy for keep-alives . . . . . . . . . . . 24
8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 23 4.1. Keep-alives for SSH . . . . . . . . . . . . . . . . . . . 24
9. References . . . . . . . . . . . . . . . . . . . . . . . . . 24 4.2. Keep-alives for TLS . . . . . . . . . . . . . . . . . . . 25
9.1. Normative References . . . . . . . . . . . . . . . . . . 24 5. Security Considerations . . . . . . . . . . . . . . . . . . . 25
9.2. Informative References . . . . . . . . . . . . . . . . . 25 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 26
Appendix A. Examples . . . . . . . . . . . . . . . . . . . . . . 26 7. Other Considerations . . . . . . . . . . . . . . . . . . . . 26
A.1. SSH Transport Configuration . . . . . . . . . . . . . . . 26 8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 26
A.2. TLS Transport Configuration . . . . . . . . . . . . . . . 26 9. References . . . . . . . . . . . . . . . . . . . . . . . . . 27
Appendix B. Change Log . . . . . . . . . . . . . . . . . . . . . 27 9.1. Normative References . . . . . . . . . . . . . . . . . . 27
B.1. 00 to 01 . . . . . . . . . . . . . . . . . . . . . . . . 28 9.2. Informative References . . . . . . . . . . . . . . . . . 28
B.2. 01 to 02 . . . . . . . . . . . . . . . . . . . . . . . . 28 Appendix A. Examples . . . . . . . . . . . . . . . . . . . . . . 29
B.3. 02 to 03 . . . . . . . . . . . . . . . . . . . . . . . . 28 A.1. SSH Transport Configuration + State . . . . . . . . . . . 29
Appendix C. Open Issues . . . . . . . . . . . . . . . . . . . . 28 A.2. TLS Transport Configuration + State . . . . . . . . . . . 31
Appendix B. Change Log . . . . . . . . . . . . . . . . . . . . . 32
B.1. 00 to 01 . . . . . . . . . . . . . . . . . . . . . . . . 33
B.2. 01 to 02 . . . . . . . . . . . . . . . . . . . . . . . . 33
B.3. 02 to 03 . . . . . . . . . . . . . . . . . . . . . . . . 33
B.4. 03 to 04 . . . . . . . . . . . . . . . . . . . . . . . . 33
Appendix C. Open Issues . . . . . . . . . . . . . . . . . . . . 34
1. Introduction 1. Introduction
This draft defines a NETCONF [RFC6241] server configuration data This draft defines a NETCONF [RFC6241] server configuration data
model. This data model enables configuration of the NETCONF service model. This data model enables configuration of the NETCONF service
itself, including which transports are supported, what ports does the itself, including which transports are supported, what ports the
server listen on, whether call-home is supported, and associated server listens on, whether call-home is supported, and associated
parameters. parameters.
1.1. Terminology 1.1. Terminology
The keywords "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", The keywords "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in RFC 2119 [RFC2119]. document are to be interpreted as described in RFC 2119 [RFC2119].
1.2. Tree Diagrams 1.2. Tree Diagrams
skipping to change at page 3, line 33 skipping to change at page 3, line 39
o Symbols after data node names: "?" means an optional node, "!" o Symbols after data node names: "?" means an optional node, "!"
means a presence container, and "*" denotes a list and leaf-list. means a presence container, and "*" denotes a list and leaf-list.
o Parentheses enclose choice and case nodes, and case nodes are also o Parentheses enclose choice and case nodes, and case nodes are also
marked with a colon (":"). marked with a colon (":").
2. Objectives 2. Objectives
The primary purpose of the YANG module defined herein is to enable The primary purpose of the YANG module defined herein is to enable
the configuration of the NETCONF service on the device. This scope the configuration of the NETCONF server service on the device. This
includes the following objectives: scope includes the following objectives:
2.1. Support all NETCONF Transports 2.1. Support all NETCONF transports
The YANG module should support all current NETCONF transports, namely The YANG module should support all current NETCONF transports, namely
NETCONF over SSH [RFC6242] and NETCONF over TLS [rfc5539bis], and be NETCONF over SSH [RFC6242] and NETCONF over TLS [rfc5539bis], and be
extensible to support future transports as necessary. extensible to support future transports as necessary.
Since implementations may not support all transports, the module Because implementations may not support all transports, the module
should use YANG "feature" statements so that implementations can should use YANG "feature" statements so that implementations can
accurately advertise which transports are supported. accurately advertise which transports are supported.
2.2. Align Transport-Specific Configurations 2.2. Enable each transport to select which keys to use
While each transport is unique in its protocol and may have some Systems may have a multiplicity of host-keys or server-certificates
distinct configurations, there remains a significant overlap between from which subsets are configured for specific uses. For instance, a
them. Thus the YANG module should use "grouping" statements so that system may want to use one set of SSH host-keys when listening on
the common aspects can be configured similarly. port 830, and a different set of SSH host-keys when calling home.
2.3. Support both Listening for Connections and Call Home 2.3. Support authenticating client-certificates
When certificates are used to authenticate NETCONF clients, there is
a need to configure the system to know how to authenticate the
certificates. The system 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.
2.4. Support mapping authenticated client-certificates to usernames
Some 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."
2.5. Support both Listening for connections and Call Home
NETCONF has always supported the server opening a port to listen for NETCONF has always supported the server opening a port to listen for
client connections. More recently the NETCONF working group defined client connections. More recently the NETCONF working group defined
support for call-home ([draft-ietf-netconf-call-home]). The module support for call-home ([draft-ietf-netconf-call-home]). The module
should configure both listening for connections and call-home. should configure both listening for connections and call-home.
Since implementations may not support both listening for connections Because implementations may not support both listening for
and call home, YANG "feature" statements should be used so that connections and call home, YANG "feature" statements should be used
implementation can accurately advertise the connection types it so that implementation can accurately advertise the connection types
supports. it supports.
2.4. For Call Home Connections 2.6. For Call Home connections
The following objectives only pertain to call home connections. The following objectives only pertain to call home connections.
2.4.1. Support More than One Application 2.6.1. Support more than one application
A device may be managed by more than one northbound application. For A device may be managed by more than one northbound application. For
instance, a deployment may have one application for provisioning and instance, a deployment may have one application for provisioning and
another for fault monitoring. Therefore, when it is desired for a another for fault monitoring. Therefore, when it is desired for a
device to initiate call home connections, it should be able to do so device to initiate call home connections, it should be able to do so
for more than one application. for more than one application.
2.4.2. Support Applications Having More than One Server 2.6.2. Support applications having more than one server
An application managing a device may implement a high-availability An application managing a device may implement a high-availability
strategy employing a multiplicity of active and/or passive servers. strategy employing a multiplicity of active and/or passive servers.
Therefore, when it is desired for a device to initiate call home Therefore, when it is desired for a device to initiate call home
connections, it should be able to connect to any of the applications connections, it should be able to connect to any of the application's
servers. servers.
2.4.3. Support a Reconnection Strategy 2.6.3. Support a reconnection strategy
Assuming an application has more than one server, then it becomes Assuming an application has more than one server, then it becomes
necessary to configure how a device should reconnect to the necessary to configure how a device should reconnect to the
application should it lose its connection to the application's application should it lose its connection to the application's
servers. Of primary interest is if the device should start with servers. Of primary interest is if the device should start with
first server defined in a user-ordered list of servers or with the first server defined in a user-ordered list of servers or with the
last server it was connected to. Secondary settings might specify last server it was connected to. Secondary settings might specify
the frequency of attempts and number of attempts per server. the frequency of attempts and number of attempts per server.
Therefore, a reconnection strategy should be configurable. Therefore, a reconnection strategy should be configurable.
2.4.4. Support both Persistent and Periodic Connections 2.6.4. Support both persistent and periodic connections
Applications may vary greatly on how frequently they need to interact Applications may vary greatly on how frequently they need to interact
with a device, how responsive interactions with devices need to be, with a device, how responsive interactions with devices need to be,
and how many simultaneous connections they can support. Some and how many simultaneous connections they can support. Some
applications may need a persistent connection to devices to optimize applications may need a persistent connection to devices to optimize
real-time interactions, while others are satisfied with periodic real-time interactions, while others are satisfied with periodic
interactions and reduced resources required. Therefore, when it is interactions and reduced resources required. Therefore, when it is
necessary for devices to initiate connections, the type of connection necessary for devices to initiate connections, the type of connection
desired should be configured. desired should be configured.
2.4.5. Reconnection Strategy for Periodic Connections 2.6.5. Reconnection strategy for periodic connections
The reconnection strategy should apply to both persistent and The reconnection strategy should apply to both persistent and
periodic connections. How it applies to periodic connections becomes periodic connections. How it applies to periodic connections becomes
clear when considering that a periodic "connection" is a logical clear when considering that a periodic "connection" is a logical
connection to a single server. That is, the periods of connection to a single server. That is, the periods of
unconnectedness are intentional as opposed to due to external unconnectedness are intentional as opposed to due to external
reasons. A periodic "connection" should always reconnect to the same reasons. A periodic "connection" should always reconnect to the same
server until it is no longer able to, at which time the reconnection server until it is no longer able to, at which time the reconnection
strategy guides how to connect to another server. strategy guides how to connect to another server.
2.4.6. Keep-Alives for Persistent Connections 2.6.6. Keep-alives for persistent connections
If a persistent connection is desired, it is the responsibility of 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 connection. The connection initiator must immediately work to
reestablish a persistent connection as soon as the connection is reestablish a persistent connection as soon as the connection is
lost. How often the connection should be tested is driven by lost. How often the connection should be tested is driven by
applications requirements, and therefore keep-alive settings should application requirements, and therefore keep-alive settings should be
be configurable on a per-application basis. configurable on a per-application basis.
2.4.7. Customizations for Periodic Connections 2.6.7. Customizations for periodic connections
If a periodic connection is desired, it is necessary for the device If a periodic connection is desired, it is necessary for the device
to know how often it should connect. This delay essentially to know how often it should connect. This delay essentially
determines how long the application might have to wait to send data determines how long the application might have to wait to send data
to the device. This setting does not constrain how often the device to the device. This setting does not constrain how often the device
must wait to send data to the application, as the device should must wait to send data to the application, as the device should
immediately connect to the application whenever it has data to send immediately connect to the application whenever it has data to send
to it. to it.
A common communication pattern is that one data transmission is many A common communication pattern is that one data transmission is many
skipping to change at page 6, line 9 skipping to change at page 6, line 29
to send a notification message, there's a high probability that it to send a notification message, there's a high probability that it
will send another shortly thereafter. Likewise, the application may will send another shortly thereafter. Likewise, the application may
have a sequence of pending messages to send. Thus, it should be have a sequence of pending messages to send. Thus, it should be
possible for a device to hold a connection open until some amount of possible for a device to hold a connection open until some amount of
time of no data being transmitted as transpired. time of no data being transmitted as transpired.
3. Data Model 3. Data Model
3.1. Overview 3.1. Overview
The following subtree illustrates how this YANG module enables 3.1.1. The "session-options" subtree
module: ietf-netconf-server
+--rw netconf-server
+--rw session-options
+--rw hello-timeout? uint32
+--rw idle-timeout? uint32
The above subtree illustrates how this YANG module enables
configuration of NETCONF session options, independent of any
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 {"(ssh-listen or tls-listen)"}? // YANG 1.1 syntax
+--rw max-sessions? 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* string
| +--:(tls) {tls-listen}?
| +--rw tls
| +--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 this YANG module enables
configuration for listening for remote connections, as described in configuration for listening for remote connections, as described in
[RFC6242] and [rfc5539bis]. Feature statements are used to limit [RFC6242] and [rfc5539bis]. Feature statements are used to limit
both if listening is supported at all as well as for which both if listening is supported at all as well as for which
transports. If listening for connections is supported, then the transports. If listening for connections is supported, then the
model enables configuring a list of listening endpoints, each model enables configuring a list of listening endpoints, each
configured with a user-specified name (the key field), the transport 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. 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 The port field is optional, defaulting to the transport-specific port
when not configured. when not configured.
module: ietf-netconf-server 3.1.3. The "call-home" subtree
+--rw netconf-server module: ietf-netconf-server
+--rw listen* [name] +--rw netconf-server
+--rw name string +--rw call-home {"(ssh-call-home or tls-call-home)"}? // YANG 1.1 syntax
+--rw (transport) +--rw application* [name]
+--:(ssh) {ssh-listen}?
| +--rw ssh
| +--rw address inet:host
| +--rw port? inet:port-number
+--:(tls) {tls-listen}?
+--rw tls
+--rw address inet:host
+--rw port? inet:port-number
The following subtree illustrates how this 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.
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.
module: ietf-netconf-server
+--rw netconf-server
+--rw call-home* [name]
+--rw name string +--rw name string
+--rw (transport) +--rw (transport)
| +--:(ssh) {ssh-call-home}? | +--:(ssh) {ssh-call-home}?
| | +--rw ssh | | +--rw ssh
| | +--rw endpoints | | +--rw endpoints
| | | +--rw endpoint* [name] | | | +--rw endpoint* [name]
| | | +--rw name string | | | +--rw name string
| | | +--rw address inet:host | | | +--rw address inet:host
| | | +--rw port? inet:port-number | | | +--rw port? inet:port-number
| | +--rw host-key* [name] | | +--rw host-keys
| | +--rw name string | | +--rw host-key* string
| +--:(tls) {tls-call-home}? | +--:(tls) {tls-call-home}?
| +--rw tls | +--rw tls
| +--rw endpoints | +--rw endpoints
| +--rw endpoint* [name] | | +--rw endpoint* [name]
| +--rw name string | | +--rw name string
| +--rw address inet:host | | +--rw address inet:host
| +--rw port? inet:port-number | | +--rw port? inet:port-number
| +--rw certificates
| +--rw certificate* string
+--rw connection-type +--rw connection-type
| +--rw (connection-type)? | +--rw (connection-type)?
| +--:(persistent-connection) | +--:(persistent-connection)
| | +--rw persistent | | +--rw persistent
| | +--rw keep-alives | | +--rw keep-alives
| | +--rw interval-secs? uint8 | | +--rw interval-secs? uint8
| | +--rw count-max? uint8 | | +--rw count-max? uint8
| +--:(periodic-connection) | +--:(periodic-connection)
| +--rw periodic | +--rw periodic
| +--rw timeout-mins? uint8 | +--rw timeout-mins? uint8
| +--rw linger-secs? uint8 | +--rw linger-secs? uint8
+--rw reconnect-strategy +--rw reconnect-strategy
+--rw start-with? enumeration +--rw start-with? enumeration
+--rw interval-secs? uint8 +--rw interval-secs? uint8
+--rw count-max? uint8 +--rw count-max? uint8
The following subtree illustrates how this YANG module enables The above subtree illustrates how this YANG module enables
authentication of TLS client certificates and mapping TLS clients to configuration for call home, as described in
NETCONF user names. More specifically, the "trusted-ca-certs" and [draft-ietf-netconf-call-home]. Feature statements are used to limit
"trusted-client-certs" containers are used to authenticate TLS client both if call-home is supported at all as well as for which
certificates, while "cert-maps" and "psk-maps" are used to map TLS transports, if it is. If call-home is supported, then the model
clients to NETCONF user names. 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.
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.
3.1.4. The "ssh" subtree
module: ietf-netconf-server module: ietf-netconf-server
+--rw netconf-server +--rw netconf-server
+--rw tls-client-auth +--rw ssh
+--rw trusted-ca-certs +--ro host-keys
| +--rw trusted-ca-cert* binary +--ro host-key* [name]
+--rw trusted-client-certs +--ro name string
| +--rw trusted-client-cert* binary +--ro format-identifier string
+--rw cert-maps {tls-map-certificates}? +--ro data binary
| +--rw cert-to-name* [id] +--ro fingerprint string
| +--rw id uint32
| +--rw fingerprint x509c2n:tls-fingerprint The above subtree illustrates how this YANG module provides SSH state
| +--rw map-type identityref independent of if the NETCONF server if listening or calling home.
| +--rw name string This data-model provides a read-only listing of currently configured
+--rw psk-maps {tls-map-pre-shared-keys}? TLC certificates.
+--rw psk-map* [psk-identity]
+--rw psk-identity string 3.1.5. The "tls" subtree
+--rw user-name nacm:user-name-type
+--rw not-valid-before? yang:date-and-time module: ietf-netconf-server
+--rw not-valid-after? yang:date-and-time +--rw netconf-server
+--rw key yang:hex-string +--rw tls
+--ro certificates
| +--ro certificate* [name]
| +--ro name string
| +--ro data binary
+--rw client-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 this YANG module provides TLS state
and enables TLS configuration independent of if the NETCONF server if
listening or calling home. This data-model provides 1) a read-only
listing of currently configured TLC certificates and 2) an ability to
configure how client-certificates are authenicated and how
authenticated client-certificates are mapped to NETCONF user names.
3.2. YANG Module 3.2. YANG Module
This YANG module imports YANG types from [RFC6991], [RFC6536], and This YANG module imports YANG types from [RFC6991], and
[draft-ietf-netmod-snmp-cfg]. [draft-ietf-netmod-snmp-cfg].
RFC Ed.: update the date below with the date of RFC publication RFC Ed.: update the date below with the date of RFC publication
and remove this note. and remove this note.
<CODE BEGINS> file "ietf-netconf-server@YYYY-MM-DD.yang" <CODE BEGINS> file "ietf-netconf-server@2014-10-26.yang"
module ietf-netconf-server { module ietf-netconf-server {
namespace "urn:ietf:params:xml:ns:yang:ietf-netconf-server"; namespace "urn:ietf:params:xml:ns:yang:ietf-netconf-server";
prefix "ncserver"; prefix "ncserver";
import ietf-inet-types { import ietf-inet-types {
prefix inet; // RFC 6991 prefix inet; // RFC 6991
} }
import ietf-yang-types {
prefix yang; // RFC 6991
}
import ietf-netconf-acm {
prefix nacm; // RFC 6536
}
import ietf-x509-cert-to-name { import ietf-x509-cert-to-name {
prefix x509c2n; // draft-ietf-netmod-snmp-cfg prefix x509c2n; // draft-ietf-netmod-snmp-cfg
} }
organization organization
"IETF NETCONF (Network Configuration) Working Group"; "IETF NETCONF (Network Configuration) Working Group";
contact contact
"WG Web: <http://tools.ietf.org/wg/netconf/> "WG Web: <http://tools.ietf.org/wg/netconf/>
WG List: <mailto:netconf@ietf.org> WG List: <mailto:netconf@ietf.org>
WG Chair: Mehmet Ersue WG Chair: Mehmet Ersue
<mailto:mehmet.ersue@nsn.com> <mailto:mehmet.ersue@nsn.com>
skipping to change at page 9, line 41 skipping to change at page 11, line 19
Legal Provisions Relating to IETF Documents Legal Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info). (http://trustee.ietf.org/license-info).
This version of this YANG module is part of RFC XXXX; see This version of this YANG module is part of RFC XXXX; see
the RFC itself for full legal notices."; the RFC itself for full legal notices.";
// RFC Ed.: replace XXXX with actual RFC number and // RFC Ed.: replace XXXX with actual RFC number and
// remove this note // remove this note
// RFC Ed.: please update the date to the date of publication // RFC Ed.: please update the date to the date of publication
revision "YYYY-MM-DD" { revision "2014-10-26" { // YYYY-MM-DD
description description
"Initial version"; "Initial version";
reference reference
"RFC XXXX: NETCONF Server Configuration Model"; "RFC XXXX: NETCONF Server Configuration Model";
} }
// Features // Features
feature ssh-listen { feature ssh-listen {
description description
"The ssh-listen feature indicates that the NETCONF server can "The ssh-listen feature indicates that the NETCONF server can
open a port to listen for incoming client connections."; open a port to listen for incoming client connections.";
} }
feature ssh-call-home { feature ssh-call-home {
description description
"The ssh-call-home feature indicates that the NETCONF server can "The ssh-call-home feature indicates that the NETCONF server can
connect to a client."; connect to a client.";
skipping to change at page 10, line 28 skipping to change at page 12, line 4
feature tls-listen { feature tls-listen {
description description
"The tls-listen feature indicates that the NETCONF server can "The tls-listen feature indicates that the NETCONF server can
open a port to listen for incoming client connections."; open a port to listen for incoming client connections.";
} }
feature tls-call-home { feature tls-call-home {
description description
"The tls-call-home feature indicates that the NETCONF server can "The tls-call-home feature indicates that the NETCONF server can
connect to a client."; connect to a client.";
}
feature tls-map-certificates {
description
"The tls-map-certificates feature indicates that the
NETCONF server implements mapping X.509 certificates to NETCONF
usernames.";
} }
feature tls-map-pre-shared-keys { // top-level container (groupings below)
description
"The tls-map-pre-shared-keys feature indicates that the
NETCONF server implements mapping TLS pre-shared keys
to NETCONF usernames.";
}
// Module's top-level container
container netconf-server { container netconf-server {
description description
"Top-level container for NETCONF server configuration."; "Top-level container for NETCONF server configuration.";
list listen {
key name;
description
"List of endpoints to listen for connections on.";
//if-feature "(ssh-listen or tls-listen)";
uses listen-config;
}
list call-home {
key name;
description
"List of applications to call-home to.";
//if-feature "(ssh-call-home or tls-call-home)";
uses call-home-config;
}
container tls-client-auth {
//if-feature "(tls-listen or tls-call-home)";
description
"Container for TLS client authentication configuration.";
uses trusted-ca-certs-grouping;
uses trusted-client-certs-grouping;
uses cert-maps-grouping;
uses psk-maps-grouping;
}
}
// Groupings uses session-options-container;
uses listen-container;
uses call-home-container;
uses ssh-container;
uses tls-container;
grouping listen-config { }
grouping session-options-container {
description description
"Grouping for listen configuration."; "";
leaf name { container session-options {
type string;
description
"An arbitrary name for the listen endpoint.";
}
choice transport {
mandatory true;
description description
"Selects between SSH and TLS transports."; "NETCONF session options, independent of transport
case ssh { or connection strategy.";
if-feature ssh-listen; leaf hello-timeout {
container ssh { type uint32 {
description range "0 | 10 .. 3600";
"SSH-specific listening configuration for inbound
connections.";
uses listen-per-transport-config {
refine port {
default 830;
}
}
} }
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 of seconds elapses.
If this parameter is set to zero, then the server
will wait forever for a hello message, and not
drop any sessions stuck in 'hello-wait' state.
Setting this parameter to zero may permit
denial of service attacks, since only a limited
number of concurrent sessions are supported
by the server.";
} }
case tls { leaf idle-timeout {
if-feature tls-listen; type uint32 {
container tls { range "0 | 10 .. 360000";
description
"TLS-specific listening configuration for inbound
connections.";
uses listen-per-transport-config {
refine port {
default 6513;
}
}
} }
} units "seconds";
} default '3600';
} description
"Specifies the number of seconds that a session
may remain idle without issuing any RPC requests.
A session will be dropped if it is idle for an
interval longer than this number of seconds.
grouping listen-per-transport-config { Sessions that have a notification subscription
description active are never dropped.
"Provides the configuration of the NETCONF server to
open one or more ports to listen for incoming client
connections.";
leaf address {
type inet:host;
mandatory true;
description
"The local IP address/name 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 call-home-config { If this parameter is set to zero, then the server
description will never drop a session because it is idle.";
"Grouping for call-home configuration."; }
leaf name {
type string;
description
"An arbitrary name for the remote application.";
} }
uses call-home-transport-config;
uses call-home-connection-type-config;
uses call-home-reconnection-strategy-config;
} }
grouping call-home-transport-config { grouping listen-container {
description description
"Grouping for call-home specific transport selection."; "";
choice transport { container listen {
mandatory true;
description description
"Selects between SSH and TLS transports."; "Configures listen behavior";
case ssh { //if-feature "(ssh-listen or tls-listen)";
if-feature ssh-call-home; leaf max-sessions {
container ssh { 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.";
leaf name {
type string;
description description
"Specifies SSH-specific call-home transport "An arbitrary name for the listen endpoint.";
configuration."; }
uses call-home-per-transport-config { choice transport {
refine endpoints/endpoint/port { mandatory true;
default 9999; // pending IANA assignment description
"Selects between SSH and TLS transports.";
case ssh {
if-feature ssh-listen;
container ssh {
description
"SSH-specific listening configuration for inbound
connections.";
uses address-and-port-grouping {
refine port {
default 830;
}
}
uses host-keys-container;
} }
} }
list host-key { case tls {
key name; if-feature tls-listen;
min-elements 1; container tls {
ordered-by user;
description
"User-ordered list of host-keys the SSH server
should advertise.";
leaf name {
type string;
mandatory true;
description description
"The name of a host key the device should "TLS-specific listening configuration for inbound
advertise during the SSH key exchange."; connections.";
uses address-and-port-grouping {
refine port {
default 6513;
}
}
uses certificates-container;
} }
} }
} }
} uses keep-alives-container {
case tls { refine keep-alives/interval-secs {
if-feature tls-call-home; default 0; // disabled by default for listen connections
container tls {
description
"Specifies TLS-specific call-home transport
configuration.";
uses call-home-per-transport-config {
refine endpoints/endpoint/port {
default 9999; // pending IANA assignment
}
} }
} }
} }
} }
} }
grouping call-home-per-transport-config { grouping call-home-container {
description description
"Grouping for transport-specific configuration for "";
call-home connections."; container call-home {
container endpoints { //if-feature "(ssh-call-home or tls-call-home)";
description description
"Container for the list of endpoints."; "Configures call-home behavior";
list endpoint { list application {
key name; key name;
min-elements 1;
ordered-by user;
description description
"User-ordered list of endpoints for this application. "List of applications to call-home to.";
Defining more than one enables high-availability.";
leaf name { leaf name {
type string; type string;
description description
"An arbitrary name for the endpoint to connect to."; "An arbitrary name for the remote application.";
} }
leaf address { choice transport {
type inet:host;
mandatory true; mandatory true;
description description
"The hostname or IP address of the endpoint. "Selects between SSH and TLS transports.";
If a hostname is provided and DNS resolves to case ssh {
more than one IP address, the device SHOULD if-feature ssh-call-home;
try all of the ones it can based on how its container ssh {
networking stack is configured (e.g. v4, v6, description
dual-stack)."; "Specifies SSH-specific call-home transport
configuration.";
uses endpoints-container {
refine endpoints/endpoint/port {
default 8888; // pending IANA assignment
}
}
uses host-keys-container;
}
}
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 9999; // pending IANA assignment
}
}
uses certificates-container;
}
}
} }
leaf port { container connection-type {
type inet:port-number;
description description
"The IP port for this endpoint. The device will use "Indicates the NETCONF client's preference for how the
the IANA-assigned well-known port if not specified."; device's connection is maintained.";
} choice connection-type {
} default persistent-connection;
}
}
grouping call-home-connection-type-config {
description
"Grouping to define connection-type for call-home
based connections.";
container connection-type {
description
"Indicates the network manager's preference for how the
device's connection is maintained.";
choice connection-type {
default persistent-connection;
description
"Selects between persistent and periodic connections.";
case persistent-connection {
container persistent {
description description
"Maintain a persistent connection to the "Selects between persistent and periodic connections.";
network manager. If the connection goes down,
immediately start trying to reconnect to it,
using the reconnection strategy.
This connection type minimizes any case persistent-connection {
manager-to-device data-transfer delay, container persistent {
albeit at the expense of holding resources
longer.";
container keep-alives {
description
"Configures keep-alive policy, to proactively
detect when a persistent connection to an
endpoint has dropped.";
leaf interval-secs {
type uint8;
units seconds;
default 15;
description description
"Sets a timeout interval in seconds after which "Maintain a persistent connection to the
if no data has been received from the manager's NETCONF client. If the connection goes down,
endpoint, a message will be sent to request a immediately start trying to reconnect to it,
response from the endpoint. A value of '0' using the reconnection strategy.
indicates that no keep-alive messages should
be sent."; This connection type minimizes any NETCONF
client to NETCONF server data-transfer delay,
albeit at the expense of holding resources
longer.";
uses keep-alives-container {
refine keep-alives/interval-secs {
default 15; // 15 seconds for call-home sessions
}
}
} }
leaf count-max { }
type uint8; case periodic-connection {
default 3; container periodic {
description description
"Sets the number of keep-alive messages that may "Periodically connect to NETCONF client, using the
be sent without receiving any data from the reconnection strategy, so the NETCONF client can
manager's endpoint before assuming the endpoint deliver pending messages to the NETCONF server.
is no longer alive. If this threshold is
reached, the transport-level connection will be For messages the NETCONF server wants to send to
disconnected (thus triggering the reconnection to the NETCONF client, the NETCONF server should
strategy). The interval timer is reset after proactively connect to the NETCONF client, if
each transmission, thus an unresponsive not already, to send the messages immediately.";
endpoint will be disconnected after about leaf timeout-mins {
count-max * interval-secs seconds."; type uint8;
units minutes;
default 5;
description
"The maximum amount of unconnected time the
device will wait until establishing a
connection to the NETCONF client again. The
device MAY establish a connection before this
time if it has data it needs to send to the
NETCONF client. Note: this value differs from
the reconnection strategy's interval-secs
value.";
}
leaf linger-secs {
type uint8;
units seconds;
default 30;
description
"The amount of time the device should wait after
last receiving data from or sending data to the
NETCONF client's endpoint before closing its
connection to it. This is an optimization to
prevent unnecessary connections.";
}
} }
} }
} }
} }
case periodic-connection { container reconnect-strategy {
container periodic { description
description "The reconnection strategy guides how a device reconnects
"Periodically connect to network manager, using the to an application, after losing a connection to it,
reconnection strategy, so it can flush any pending even if due to a reboot. The device starts with the
data it may be holding. This connection type specified endpoint, tries to connect to it count-max
minimizes resources held open, albeit at the times, waiting interval-secs between each connection
expense of longer manager-to-device data-transfer attempt, before trying the next endpoint in the list
delay. Note that for device-to-manager data, the (round robin).";
data should be sent immediately, connecting to leaf start-with {
network manager first if not already."; type enumeration {
leaf timeout-mins { enum first-listed {
type uint8; description
units minutes; "Indicates that reconnections should start with
default 5; the first endpoint listed.";
description }
"The maximum amount of unconnected time the enum last-connected {
device will wait until establishing a description
connection to the network manager again. The "Indicates that reconnections should start with
device MAY establish a connection before this the endpoint last connected to. NETCONF servers
time if it has data it needs to send to the SHOULD support this flag across reboots.";
network manager. Note: this value differs from }
the reconnection strategy's interval-secs
value.";
}
leaf linger-secs {
type uint8;
units seconds;
default 30;
description
"The amount of time the device should wait after
last receiving data from or sending data to the
network manager's endpoint before closing its
connection to it. This is an optimization to
prevent unnecessary connections.";
} }
default first-listed;
description
"Specifies which of the application's endpoints the
device should start with when trying to connect to
the application. If no previous connection has
ever been established, last-connected defaults to
the first endpoint listed.";
}
leaf interval-secs {
type uint8;
units seconds;
default 5;
description
"Specifies the time delay between connection attempts
to the same endpoint. Note: this value differs from
the periodic-connection's timeout-mins value.";
}
leaf count-max {
type uint8;
default 3;
description
"Specifies the number times the device tries to
connect to a specific endpoint before moving on to
the next endpoint in the list (round robin).";
} }
} }
} }
} }
} }
grouping call-home-reconnection-strategy-config { grouping ssh-container {
description description
"Grouping for reconnection strategy."; "";
container reconnect-strategy { container ssh {
description description
"The reconnection strategy guides how a device reconnects "Configures SSH properties not specific to the listen
to an application, after losing a connection to it, or call-home use-cases";
even if due to a reboot. The device starts with the //if-feature "(ssh-listen or ssh-call-home)";
specified endpoint, tries to connect to it count-max container host-keys {
times, waiting interval-secs between each connection config false;
attempt, before trying the next endpoint in the list description
(round robin)."; "Parent container for a list of host keys";
leaf start-with { list host-key {
type enumeration { key name;
enum first-listed { description
"A read-only list of host-keys supported by server";
leaf name {
type string;
description description
"Indicates that reconnections should start with "Common name for the host-key";
the first endpoint listed.";
} }
enum last-connected { leaf format-identifier {
type string;
mandatory true;
description description
"Indicates that reconnections should start with "ssh-dss, ssh-rsa, x509v3-rsa2048-sha256, etc.";
the endpoint last connected to."; reference
"RFC 4253: SSH Transport Layer Protocol, section 6.6
RFC 6187: X.509v3 Certificates for SSH, section 3";
}
leaf data {
type binary;
mandatory true;
description
"Key-specific binary encoding.";
reference
"RFC 4253: SSH Transport Layer Protocol, section 6.6";
}
leaf fingerprint {
type string;
mandatory true;
description
"c1:b1:30:29:d7:b8:de:6c:97:77:10:d7:46:41:63:87";
reference
"RFC 4716: The Secure Shell (SSH) Public Key File
Format, section 4";
} }
} }
default first-listed;
description
"Specifies which of the application's endpoints the
device should start with when trying to connect to
the application. If no previous connection has
ever been established, last-connected defaults to
the first endpoint listed.";
} }
leaf interval-secs { }
type uint8; }
units seconds;
default 5; grouping tls-container {
description
"";
container tls {
description
"Configures TLS properties not specific to the listen
or call-home use-cases";
//if-feature "(tls-listen or tls-call-home)";
container certificates {
config false;
description description
"Specifies the time delay between connection attempts "Parent container for a list of certificates";
to the same endpoint. Note: this value differs from list certificate {
the periodic-connection's timeout-mins value."; key name;
description
"A list of certificates";
leaf name {
type string;
description
"the certificate's common name";
}
leaf data {
type binary;
mandatory true;
description
"The binary certificate structure, as specified
by RFC 5246, Section 7.4.2, i.e.,: opaque
ASN.1Cert<1..2^24-1>;";
}
}
} }
leaf count-max { container client-auth {
type uint8;
default 3;
description description
"Specifies the number times the device tries to "Container for TLS client authentication configuration.";
connect to a specific endpoint before moving on to container trusted-ca-certs {
the next endpoint in the list (round robin)."; 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. Note, in the TLS protocol, 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;
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;
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 trusted-ca-certs-grouping { grouping host-keys-container {
description description
"Grouping for trusted-ca-certs container."; "";
container trusted-ca-certs { container host-keys {
description description
"A list of Certificate Authority (CA) certificates that a "Parent container for the list of host-keys.";
NETCONF server can use to authenticate a NETCONF client's leaf-list host-key {
certificate. A client's certificate is authenticated if type string;
its Issuer matches one of the configured trusted CA min-elements 1;
certificates."; ordered-by user;
leaf-list trusted-ca-cert {
type binary;
ordered-by system;
description description
"The binary certificate structure, as "User-ordered list of host-keys the SSH server
specified by RFC 5246, Section 7.4.6, i.e.,: considers when composing the list of server
host key algorithms it will send to the client.
opaque ASN.1Cert<1..2^24>; The value of the string is the name of a
host-key configured on the system, as returned
"; by /netconf-server/ssh/host-keys/host-key/name.";
reference reference
"RFC 5246: The Transport Layer Security (TLS) "RFC 4253: The SSH Transport Layer Protocol, Section 7";
Protocol Version 1.2";
} }
} }
} }
grouping trusted-client-certs-grouping { grouping certificates-container {
description description
"Grouping for trusted-client-certs container."; "";
container trusted-client-certs { container certificates {
description description
"A list of client certificates that a NETCONF server can "Parent container for the list of certificates.";
use to authenticate a NETCONF client's certificate. A leaf-list certificate {
client's certificate is authenticated if it is an exact type string;
match to a configured trusted client certificates."; min-elements 1;
leaf-list trusted-client-cert {
type binary;
ordered-by system;
description description
"The binary certificate structure, as "Unordered list of certificates the TLS server can
specified by RFC 5246, Section 7.4.6, i.e.,: pick from when sending its Server Certificate
message. The value of the string is the name of a
opaque ASN.1Cert<1..2^24>; certificate configured on the system, as returned by
/netconf-server/tls/certificates/certificate/name";
";
reference reference
"RFC 5246: The Transport Layer Security (TLS) "RFC 5246: The TLS Protocol, Section 7.4.2";
Protocol Version 1.2";
} }
} }
} }
// Objects for deriving NETCONF usernames from X.509 grouping address-and-port-grouping {
// certificates.
grouping cert-maps-grouping {
description description
"Grouping for cert-maps container."; "a common grouping";
container cert-maps { leaf address {
if-feature tls-map-certificates; type inet:ip-address;
uses x509c2n:cert-to-name;
description description
"The cert-maps container is used by a NETCONF server to "The IP address of the interface to listen on.";
map the NETCONF client's presented X.509 certificate to }
a NETCONF username. leaf port {
type inet:port-number;
If no matching and valid cert-to-name list entry can be description
found, then the NETCONF server MUST close the connection, "The local port number on this interface the
and MUST NOT accept NETCONF messages over it."; NETCONF server listens on.";
} }
} }
// Objects for deriving NETCONF usernames from TLS grouping endpoints-container {
// pre-shared keys.
grouping psk-maps-grouping {
description description
"Grouping for psk-maps container."; "Grouping for transport-specific configuration for
container psk-maps { call-home connections.";
if-feature tls-map-pre-shared-keys; container endpoints {
description description
"During the TLS Handshake, the client indicates which "Container for the list of endpoints.";
key to use by including a PSK identity in the TLS list endpoint {
ClientKeyExchange message. On the NETCONF server side, key name;
this PSK identity is used to look up an entry in the psk-map min-elements 1;
list. If such an entry is found, and the pre-shared keys ordered-by user;
match, then the client is authenticated. The NETCONF
server uses the value from the user-name leaf in the
psk-map list as the NETCONF username. If the NETCONF
server cannot find an entry in the psk-map list, or if
the pre-shared keys do not match, then the NETCONF
server terminates the connection.";
reference
"RFC 4279: Pre-Shared Key Ciphersuites for Transport Layer
Security (TLS)";
list psk-map {
key psk-identity;
description description
"List a pre-shared key mappings."; "User-ordered list of endpoints for this application.
Defining more than one enables high-availability.";
leaf psk-identity { leaf name {
type string; type string;
description description
"The PSK identity encoded as a UTF-8 string. For "An arbitrary name for the endpoint to connect to.";
details how certain common PSK identity formats can
be encoded in UTF-8, see section 5.1. of RFC 4279.";
reference
"RFC 4279: Pre-Shared Key Ciphersuites for Transport
Layer Security (TLS)";
} }
leaf user-name { leaf address {
type nacm:user-name-type; type inet:host;
mandatory true; mandatory true;
description description
"The NETCONF username associated with this PSK "The hostname or IP address or hostname of the
identity."; endpoint. If a hostname is provided and DNS
} resolves to more than one IP address, the device
leaf not-valid-before { SHOULD try all of the ones it can based on how
type yang:date-and-time; its networking stack is configured (e.g. v4, v6,
description dual-stack).";
"This PSK identity is not valid before the given date
and time.";
}
leaf not-valid-after {
type yang:date-and-time;
description
"This PSK identity is not valid after the given date
and time.";
} }
leaf key { leaf port {
type yang:hex-string; type inet:port-number;
mandatory true;
nacm:default-deny-all;
description description
"The key associated with the PSK identity"; "The IP port for this endpoint. The device will use
reference the IANA-assigned well-known port if not specified.";
"RFC 4279: Pre-Shared Key Ciphersuites for Transport
Layer Security (TLS)";
} }
} }
} }
} }
grouping keep-alives-container {
description
"";
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. Keepalive implementation
is described in RFC XXXX, section 4.";
reference
"RFC XXXX: NETCONF Server Configuration Model
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 value of
'0' indicates that no keep-alive messages
should be sent.";
}
leaf count-max {
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.";
}
}
}
} }
<CODE ENDS> <CODE ENDS>
4. Keep-Alives for SSH and TLS 4. Implementation strategy for keep-alives
One the objectives listed above, Keep-Alives for Persistent One of the objectives listed above, Keep-alives for persistent
Connections (Section 2.4.6) indicates a need for a "keep-alive" connections (Section 2.6.6), indicates a need for a "keep-alive"
mechanism. This section specifies how the NETCONF keep-alive mechanism. This section specifies how the NETCONF keep-alive
mechanism is to be implemented. mechanism is to be implemented for both the SSH and TLS transports.
Both SSH and TLS have the ability to support keep-alives. Using Both SSH and TLS have the ability to support keep-alives securely.
these mechanisms, the keep-alive messages are sent inside the Using the strategies listed below, the keep-alive messages are sent
encrypted tunnel, thus thwarting spoof attacks. inside the encrypted transport sessions.
4.1. SSH 4.1. Keep-alives for SSH
The SSH keep-alive solution that is expected to be used when The SSH keep-alive solution that is expected to be used is ubiquitous
configured using the data model defined in this document is in practice, though never being explicitly defined in an RFC. The
ubiquitous in practice, though never being explicitly defined in an strategy used is to purposely send a malformed request message with a
RFC. The strategy used is to purposely send a malformed request flag set to ensure a response. More specifically, per section 4 of
message with a flag set to ensure a response. More specifically, per [RFC4253], either SSH peer can send a SSH_MSG_GLOBAL_REQUEST message
section 4 of [RFC4253], either SSH peer can send a with "want reply" set to '1' and that, if there is an error, will get
SSH_MSG_GLOBAL_REQUEST message with "want reply" set to '1' and that, back a SSH_MSG_REQUEST_FAILURE response. Similarly, section 5 of
if there is an error, will get back a SSH_MSG_REQUEST_FAILURE [RFC4253] says that either SSH peer can send a
response. Similarly, section 5 of [RFC4253] says that either SSH SSH_MSG_CHANNEL_REQUEST message with "want reply" set to '1' and
peer can send a SSH_MSG_CHANNEL_REQUEST message with "want reply" set that, if there is an error, will get back a SSH_MSG_CHANNEL_FAILURE
to '1' and that, if there is an error, will get back a response.
SSH_MSG_CHANNEL_FAILURE response.
To ensure that the request will fail, current implementations send an To ensure that the request will fail, current implementations of this
invalid "request name" or "request type", respectively. Abiding to keep-alive strategy (e.g. OpenSSH's `sshd` server) send an invalid
the extensibility guidelines specified in Section 6 of [RFC4251], "request name" or "request type", respectively. Abiding to the
these implementations use the "name@domain". For instance, when extensibility guidelines specified in Section 6 of [RFC4251], these
configured to send keep-alives, OpenSSH sends the string implementations use the "name@domain". For instance, when configured
to send keep-alives, OpenSSH sends the string
"keepalive@openssh.com". In order to remain compatible with existing "keepalive@openssh.com". In order to remain compatible with existing
implementations, this draft does not require a specific "request implementations, this draft does not require a specific "request
name" or "request type" string be used. name" or "request type" string be used, implementations are free to
pick values of their choosing.
4.2. TLS 4.2. Keep-alives for TLS
The TLS keep-alive solution is defined in [RFC6520]. This solution The TLS keep-alive solution that is expected to be used is defined in
allows both peers to advertise if they can receive heartbeat request [RFC6520]. This solution allows both peers to advertise if they can
messages from its peer. For standard NETCONF over TLS connections, receive heartbeat request messages from its peer. For standard
devices SHOULD advertise "peer_allowed_to_send", as per [RFC6520]. NETCONF over TLS connections, devices SHOULD advertise
This advertisement is not a "MUST" in order to grandfather existing "peer_allowed_to_send", as per [RFC6520]. This advertisement is not
NETCONF over TLS implementations. For NETCONF over TLS Call Home, a "MUST" in order to grandfather existing NETCONF over TLS
the network management system MUST advertise "peer_allowed_to_send" implementations. For NETCONF Call Home, the network management
per [RFC6520]. This is a "MUST" so as to ensure devices can depend system MUST advertise "peer_allowed_to_send" per [RFC6520]. This is
in it always being there for call home connections, which is a "MUST" so as to ensure devices can depend in it always being there
conveniently when keep-alives are needed the most. for call home connections, which is when keep-alives are needed the
most.
5. Security Considerations 5. Security Considerations
The YANG modules defined in this memo are designed to be accessed via The YANG modules defined in this memo are designed to be accessed via
the NETCONF protocol [RFC6241]. Authorization for access to specific the NETCONF protocol [RFC6241]. Authorization for access to specific
portions of conceptual data and operations within this module is portions of conceptual data and operations within this module is
provided by the NETCONF access control model (NACM) [RFC6536]. provided by the NETCONF access control model (NACM) [RFC6536].
There are a number of data nodes defined in the "ietf-netconf-server" There are a number of data nodes defined in the "ietf-netconf-server"
and "ietf-system-tls-auth" YANG modules which are writable/creatable/ YANG module which are readable and/or writable that may be considered
deletable (i.e., config true, which is the default). These data sensitive or vulnerable in some network environments. Write and read
nodes may be considered sensitive or vulnerable in some network operations to these data nodes can have a negative effect on network
environments. Write and read operations to these data nodes can have operations. It is thus important to control write and read access to
a negative effect on network operations. It is thus important to these data nodes. Below are the data nodes and their sensitivity/
control write and read access to these data nodes. Below are the vulnerability.
data nodes and their sensitivity/vulnerability.
ietf-netconf-server: netconf-server/tls/client-auth/trusted-ca-certs:
o None. o This container contains certificates that the system is to use as
trust anchors for authenticating TLS-specific client certificates.
Write access to this node should be protected.
ietf-system-tls-auth: netconf-server/tls/client-auth/trusted-client-certs:
o /system/authentication/tls/psk-maps/psk-map/user-name: This leaf o This container contains certificates that the system is to trust
node contains a user name that some deployments may consider directly when authenticating TLS-specific client certificates.
sensitive information. Write access to this node should be protected.
o /system/authentication/tls/psk-maps/psk-map/key: This leaf node netconf-server/tls/client-auth/cert-map:
contains a shared key that remote clients use to authenticate
themselves to the system. This value should not be readable or o This container contains a user name that some deployments may
writable by anyone by default. consider sensitive information. Read access to this node may need
to be guarded.
6. IANA Considerations 6. IANA Considerations
This document registers two URIs in the IETF XML registry [RFC2119]. This document registers two URIs in the IETF XML registry [RFC2119].
Following the format in [RFC3688], the following registrations are Following the format in [RFC3688], the following registrations are
requested: requested:
URI: urn:ietf:params:xml:ns:yang:ietf-netconf-server URI: urn:ietf:params:xml:ns:yang:ietf-netconf-server
Registrant Contact: The NETCONF WG of the IETF. Registrant Contact: The NETCONF WG of the IETF.
XML: N/A, the requested URI is an XML namespace. XML: N/A, the requested URI is an XML namespace.
skipping to change at page 24, line 46 skipping to change at page 28, line 7
[RFC6991] Schoenwaelder, J., "Common YANG Data Types", RFC 6991, [RFC6991] Schoenwaelder, J., "Common YANG Data Types", RFC 6991,
July 2013. July 2013.
[draft-ietf-netconf-call-home] [draft-ietf-netconf-call-home]
Watsen, K., "NETCONF Call Home", draft-ieft-netconf-call- Watsen, K., "NETCONF Call Home", draft-ieft-netconf-call-
home-00 (work in progress), 2014. home-00 (work in progress), 2014.
[draft-ietf-netmod-snmp-cfg] [draft-ietf-netmod-snmp-cfg]
Bjorklund, M. and J. Schoenwaelder, "A YANG Data Model for Bjorklund, M. and J. Schoenwaelder, "A YANG Data Model for
SNMP Configuration", draft-ietf-netmod-snmp-cfg-03 (work SNMP Configuration", draft-ietf-netmod-snmp-cfg-08 (work
in progress), November 2013. in progress), September 2014.
[rfc5539bis] [rfc5539bis]
Badra, M., Luchuk, A., and J. Schoenwaelder, "Using the Badra, M., Luchuk, A., and J. Schoenwaelder, "Using the
NETCONF Protocol over Transport Layer Security (TLS)", NETCONF Protocol over Transport Layer Security (TLS)",
draft-ietf-netconf-rfc5539bis-04 (work in progress), draft-ietf-netconf-rfc5539bis-04 (work in progress),
October 2013. October 2013.
9.2. Informative References 9.2. Informative References
[RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688, [RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688,
January 2004. January 2004.
Appendix A. Examples Appendix A. Examples
A.1. SSH Transport Configuration A.1. SSH Transport Configuration + State
The following example illustrastes the <get> response from a NETCONF
server that only supports SSH, both listening for incoming
connections as well as calling home to a single application having
two endpoints. Please also note that the list of host-keys at the
end is read-only operational state.
<netconf-server xmlns="urn:ietf:params:xml:ns:yang:ietf-netconf-server"> <netconf-server xmlns="urn:ietf:params:xml:ns:yang:ietf-netconf-server">
<listen> <listen>
<name>foo bar</name> <endpoint>
<ssh> <name>foo bar</name>
<port>831</port> <ssh>
</ssh> <address>11.22.33.44</address>
<host-keys>
<host-key>my-rsa-key</host-key>
<host-key>my-dss-key</host-key>
</host-keys>
</ssh>
</endpoint>
</listen> </listen>
<call-home> <call-home>
<name>config-mgr</name> <application>
<ssh> <name>config-mgr</name>
<endpoints> <ssh>
<endpoint> <endpoints>
<name>east-data-center</name> <endpoint>
<address>11.22.33.44</address> <name>east-data-center</name>
</endpoint> <address>11.22.33.44</address>
<endpoint> </endpoint>
<name>west-data-center</name> <endpoint>
<address>55.66.77.88</address> <name>west-data-center</name>
</endpoint> <address>55.66.77.88</address>
</endpoints> </endpoint>
</ssh> </endpoints>
<host-keys>
<host-key>my-call-home-x509-key</host-key>
</host-keys>
</ssh>
</application>
</call-home> </call-home>
<ssh>
<host-keys>
<host-key>
<name>my-rsa-key</name>
<format-identifier>ssh-rsa</format-identifier>
<data> <!-- base64 reformated for draft -->
AAAAB3NzaC1yc2EAAAABIwAAAQEA7D2lxYg3+WD97RZqZtO8bUU8QpIl6g9
X11kZHZ8NgSIR+x2H1MHCD5sEjmx/B6JIouK5eBvbJE9FFV3phsl62fupN6
Y4EmXosC6iqpuI41dcGA63XCQ1OenWG4ppdq1f8tlecSrmEcLw7MKPzBHK6
rNQTciqMuVuLPOKwBu/54QAiUwvvHKAsk8bkN9YxEJ1NTV1FFQmvMOADVcD
2qqPangETwV5zInW8AEkBbLccM/mmHucGNS81axXR3V9R5KgXF2DyGB47d2
k6iOnGa3LBIOYi/5Q+O8IFUlO+kytfqwuFgUc+Mx7aKReSIAPov3owVjeBL
KWsvjD24UO68qtwQ==
</data>
<fingerprint>
c1:b1:30:29:d7:b8:de:6c:97:77:10:d7:46:41:63:87
</fingerprint>
</host-key>
<host-key>
<name>my-dss-key</name>
<format-identifier>ssh-dss</format-identifier>
<data> <!-- base64 reformated for draft -->
AAAAB3NzaC1kc3MAAACBAIq7XfGmZKJgibJEIMzj70YMVfpeewBCj89VrUS
gLsJmxP/TrXFuhzW2UIaI8sePMYUXj/Vgp5DUD+eBSBkHMH4ga0U5t/clqn
y73x8Vg6LQg9f0OTaUnpRWbWrdac7U5/BRBTtMA3amHZhHrKs7BrCepS/y8
cUbxBCPF3aYMK/5AAAAFQC7wetEbDwghYtz8Z3xIwDdxs6mOwAAAIBursEk
jnvs5zzyUH7iNiyBojDoyrsq81jPM6KopkfA5Ypp2KTySPev/mkL0SoVfIb
+HttVfQ3Q63+sf1Qyk+gUtniSdN2AqtFQYKxtTcXim4McWk6IixkYFP8kkt
02t9Hsl0eXvltmogrlRsiuJsTAbFS+QTeq4OGTODCT5jjVdQAAAIA2llpZg
y5v46lGt4dQhkH8ytyMGyjBRPF6rm51msinX3lMR9xfwTaS7ZYP0b6HJt5M
sQI+m7iIYaVFB1oC8niXbkkavLcxhGpNVkwE2INWS4TIBbTQhivuoE+dMYY
KauLQxqSUjixJk3LjhCQb
</data>
<fingerprint>
c1:b1:30:29:d7:b8:de:6c:97:77:10:d7:46:41:63:87
</fingerprint>
</host-key>
<host-key>
<name>my-call-home-x509-key</name>
<format-identifier>x509v3-rsa2048-sha256</format-identifier>
<data> <!-- base64 reformated for draft -->
AAAAB3NzaC1yc2EAAAABIwAAAQEAyBLl90dPUGX7Es12q7YKkw6v8WgWop+
B62zhT39C+yvslMIwIqgHYii0h/TGktahKpBwssawfhvAZoMF/nOyO3yDPD
pQxNrA76H7owNOjG5206QHDYfVALKPvxgrDy/6BjsR9MayOGkZTSL6GRFSl
g7ivT9AIR9E5qXmP+1z+IDufRlpwfaGfpZAxjJLEwzAjFAIwXsXKJ5FH/QP
mfC6gxfhqpt9rJCDlgqmzrXi8dXKsFUC3/o1lzezqTXTV1iMETTuCHgWegF
5QcX2baBdFgCnkd1SnftVoBHVnvXA1euRqgiG3fMNK4rct0D99D+GI+kZc+
vQyUdCw3dPlhXPZw==
</data>
<fingerprint>
97:77:10:29:d7:b8:de:6c:97:77:30:29:d7:41:63:87
</fingerprint>
</host-key>
</host-keys>
</ssh>
</netconf-server> </netconf-server>
A.2. TLS Transport Configuration A.2. TLS Transport Configuration + State
The following example illustrastes the <get> response from a NETCONF
server that only supports TLS, both listening for incoming
connections as well as calling home to a single application having
two endpoints. Please note also the configurations for
authenticating client certificates and mappings authenticated
certificates to NETCONF user names.
<netconf-server xmlns="urn:ietf:params:xml:ns:yang:ietf-netconf-server"> <netconf-server xmlns="urn:ietf:params:xml:ns:yang:ietf-netconf-server">
<listen> <listen>
<name>foo bar</name> <endpoint>
<ssh> <name>primary-netconf-endpoint</name>
<port>831</port> <tls>
</ssh> <address>11.22.33.44</address>
<certificates>
<certificate>fw1.east.example.com</certificate>
</certificates>
</tls>
</endpoint>
</listen> </listen>
<call-home> <call-home>
<name>config-mgr</name> <application>
<tls> <name>config-mgr</name>
<endpoints> <tls>
<endpoint> <endpoints>
<name>east-data-center</name> <endpoint>
<address>11.22.33.44</address> <name>east-data-center</name>
</endpoint> <address>11.22.33.44</address>
<endpoint> </endpoint>
<name>west-data-center</name> <endpoint>
<address>55.66.77.88</address> <name>west-data-center</name>
<address>55.66.77.88</address>
</endpoint> </endpoint>
</endpoints> </endpoints>
</tls> <certificates>
<certificate>fw1.east.example.com</certificate>
</certificates>
</tls>
</application>
</call-home> </call-home>
<tls-client-auth> <tls>
<trusted-ca-certs> <certificates>
<trusted-ca-cert> <certificate>
QW4gRWFzdGVyIGVnZywgZm9yIHRob3NlIHdobyBtaWdodCBsb29rICA6KQo= <name>fw1.east.example.com</name>
</trusted-ca-cert> <data> <!-- base64 reformated for draft -->
</trusted-ca-certs> AAAAB3NzaC1yc2EAAAABIwAAAQEA7D2lxYg3+WD97RZqZtO8bUU8QpIl6g9
<trusted-client-certs> X11kZHZ8NgSIR+x2H1MHCD5sEjmx/B6JIouK5eBvbJE9FFV3phsl62fupN6
<trusted-client-cert> Y4EmXosC6iqpuI41dcGA63XCQ1OenWG4ppdq1f8tlecSrmEcLw7MKPzBHK6
SSBhbSB0aGUgZWdnIG1hbiwgdGhleSBhcmUgdGhlIGVnZyBtZW4uCg== rNQTciqMuVuLPOKwBu/54QAiUwvvHKAsk8bkN9YxEJ1NTV1FFQmvMOADVcD
</trusted-client-cert> 2qqPangETwV5zInW8AEkBbLccM/mmHucGNS81axXR3V9R5KgXF2DyGB47d2
<trusted-client-cert> k6iOnGa3LBIOYi/5Q+O8IFUlO+kytfqwuFgUc+Mx7aKReSIAPov3owVjeBL
SSBhbSB0aGUgd2FscnVzLCBnb28gZ29vIGcnam9vYi4K KWsvjD24UO68qtwQ==
</trusted-client-cert> </data>
</trusted-client-certs> </certificate>
<cert-maps> </certificates>
<cert-to-name> <client-auth>
<id>1</id> <trusted-ca-certs>
<fingerprint>11:0A:05:11:00</fingerprint> <trusted-ca-cert>
<map-type>x509c2n:san-any</map-type> QW4gRWFzdGVyIGVnZywgZm9yIHRob3NlIHdobyBtaWdodCBsb29rICA6KQo=
</cert-to-name> </trusted-ca-cert>
<cert-to-name> </trusted-ca-certs>
<id>2</id> <trusted-client-certs>
<fingerprint>11:0A:05:11:00</fingerprint> <trusted-client-cert>
<map-type>x509c2n:specified</map-type> SSBhbSB0aGUgZWdnIG1hbiwgdGhleSBhcmUgdGhlIGVnZyBtZW4uCg==
<name>Joe Cool</name> </trusted-client-cert>
</cert-to-name> <trusted-client-cert>
</cert-maps> SSBhbSB0aGUgd2FscnVzLCBnb28gZ29vIGcnam9vYi4K
<psk-maps> </trusted-client-cert>
<psk-map> </trusted-client-certs>
<psk-identity>a8gc8]klh59</psk-identity> <cert-maps>
<user-name>admin</user-name> <cert-to-name>
<not-valid-before>2013-01-01T00:00:00Z</not-valid-before> <id>1</id>
<not-valid-after>2014-01-01T00:00:00Z</not-valid-after> <fingerprint>11:0A:05:11:00</fingerprint>
</psk-map> <map-type>x509c2n:san-any</map-type>
</psk-maps> </cert-to-name>
</tls-client-auth> <cert-to-name>
<id>2</id>
<fingerprint>11:0A:05:11:00</fingerprint>
<map-type>x509c2n:specified</map-type>
<name>Joe Cool</name>
</cert-to-name>
</cert-maps>
</client-auth>
</tls>
</netconf-server> </netconf-server>
Appendix B. Change Log Appendix B. Change Log
B.1. 00 to 01 B.1. 00 to 01
o Restructured document so it flows better o Restructured document so it flows better
o Added trusted-ca-certs and trusted-client-certs objects into the o Added trusted-ca-certs and trusted-client-certs objects into the
ietf-system-tls-auth module ietf-system-tls-auth module
skipping to change at page 28, line 27 skipping to change at page 33, line 27
o removed "network-manager" terminology o removed "network-manager" terminology
o moved open issues to github issues o moved open issues to github issues
o brought TLS client auth back into model o brought TLS client auth back into model
B.3. 02 to 03 B.3. 02 to 03
o fixed tree diagrams and surrounding text o fixed tree diagrams and surrounding text
B.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
Appendix C. Open Issues Appendix C. Open Issues
Please see: https://github.com/netconf-wg/server-model/issues. Please see: https://github.com/netconf-wg/server-model/issues.
Authors' Addresses Authors' Addresses
Kent Watsen Kent Watsen
Juniper Networks Juniper Networks
EMail: kwatsen@juniper.net EMail: kwatsen@juniper.net
 End of changes. 140 change blocks. 
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