| NETCONF Working Group | K. Watsen |
| Internet-Draft | Juniper Networks |
| Intended status: Standards Track | J. Schoenwaelder |
| Expires: September 17, 2016 | Jacobs University Bremen |
| March 16, 2016 |
NETCONF Server and RESTCONF Server Configuration Models
draft-ietf-netconf-server-model-09
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.
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:
Artwork in this document contains shorthand references to drafts in progress. Please apply the following replacements:
Artwork in this document contains placeholder values for ports pending IANA assignment from "draft-ietf-netconf-call-home". Please apply the following replacements:
Artwork in this document contains placeholder values for the date of publication of this draft. Please apply the following replacement:
The following two Appendix sections are to be removed prior to publication:
Artwork in the document contains a temporary YANG containers that need to be removed.
This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79.
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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.
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].
A simplified graphical representation of the data models is used in this document. The meaning of the symbols in these diagrams is as follows:
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:
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.
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.
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.
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.
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.
The following objectives only pertain to call home connections.
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.
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.
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.
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 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.
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.
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.
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).
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.
+--------------------+
|ietf-system-keychain|
+--------------------+
^ ^
| |
<leafref> | | <leafref>
+------------+ +------------+
| |
+---------------+ +------------------+
|ietf-ssh-server| | ietf-tls-server |
+---------------+ +------------------+
^ ^ ^
| <uses> | |
| <augments> | |
| +--------------------+ | <augments>
| | |
+-------------------+ +--------------------+
|ietf-netconf-server| |ietf-restconf-server|
+-------------------+ +--------------------+
Each of the following five sections relate to one of the YANG modules depicted by the figure above.
The system keychain model defined in this section provides a configurable object having the following characteristics:
module: ietf-system-keychain
+--rw keychain
+--rw private-keys
| +--rw private-key* [name]
| | +--rw name string
| | +--ro algorithm? kc:algorithms
| | +--ro key-length? uint32
| | +--ro public-key binary
| | +--rw certificate-chains
| | | +--rw certificate-chain* [name]
| | | +--rw name string
| | | +--rw certificate* 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 key-usage? enumeration
| | +---w algorithm kc:algorithms
| | +---w key-length? uint32
| +---x load-private-key
| +---w input
| +---w name string
| +---w private-key binary
+--rw trusted-certificates* [name]
+--rw name string
+--rw description? string
+--rw trusted-certificate* [name]
+--rw name string
+--rw certificate? binary
notifications:
+---n certificate-expiration
+--ro certificate instance-identifier
+--ro expiration-date yang:date-and-time
The following example illustrates the "generate-private-key" action in use with the RESTCONF protocol and JSON encoding.
REQUEST
-------
['\' line wrapping added for formatting only]
POST https://example.com/restconf/data/ietf-system-keychain:keychain/\
private-keys/generate-private-key HTTP/1.1
HOST: example.com
Content-Type: application/yang.operation+json
{
"ietf-system-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 "load-private-key" action in use with the RESTCONF protocol and JSON encoding.
REQUEST
-------
['\' line wrapping added for formatting only]
POST https://example.com/restconf/data/ietf-system-keychain:keychain/\
private-keys/generate-private-key HTTP/1.1
HOST: example.com
Content-Type: application/yang.operation+xml
<input xmlns="urn:ietf:params:xml:ns:yang:ietf-system-keychain">
<name>ex-key-sect571r1</name>
<private-key>
NGcEk3UE90cnNFVjRwTUNBd0VBQWFPQ0FSSXdnZ0VPCk1CMEdBMVVkRGd\
VEJiZ0JTWEdlbUEKMnhpRHVOTVkvVHFLNWd4cFJBZ1ZOYUU0cERZd05ER\
V6QVJCZ05WQkFNVENrTlNUQ0JKYzNOMVpYS0NDUUNVRHBNSll6UG8zREF\
Z05WSFI4RVlqQmdNRjZnSXFBZ2hoNW9kSFJ3T2k4dlpYaGgKYlhCc1pTN\
QmdOVkJBWVRBbFZUTVJBd0RnWURWUVFLRXdkbAplR0Z0Y0d4bE1RNHdEQ\
MkF6a3hqUDlVQWtHR0dvS1U1eUc1SVR0Wm0vK3B0R2FieXVDMjBRd2kvZ\
NQmdOVkhSTUJBZjhFCkFqQUFNQTRHQTFVZER3RUIvd1FFQXdJSGdEQnBC\
WmdsK2gyTTg3QmtGMjhWbW1CdFFVaWc3OEgrRkYyRTFwdSt4ZVRJbVFFM\
lLQllsdWpOcjFTMnRLR05EMUc2OVJpK2FWNGw2NTdZNCtadVJMZgpRYjk\
zSFNwSDdwVXBCYnA4dmtNanFtZjJma3RqZHBxeFppUUtTbndWZTF2Zwot\
25PZnpZNEhONApXY0pTaUpZK2xtYWs3RTRORUZXZS9RdGp4NUlXZmdvN2\
WpiMjB2WlhoaGJYQnNaUzVqY215aU9L=
</private-key>
</input>
RESPONSE
--------
HTTP/1.1 204 No Content
Date: Mon, 31 Oct 2015 11:01:00 GMT
Server: example-server
The following example illustrates the "generate-certificate-signing-request" action in use with the NETCONF protocol.
REQUEST
-------
<rpc message-id="101"
xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<action xmlns="urn:ietf:params:xml:ns:yang:1">
<keychain
xmlns="urn:ietf:params:xml:ns:yang:ietf-system-keychain">
<private-keys>
<private-key>
<name>ex-key-sect571r1</name>
<generate-certificate-signing-request>
<subject>
cztvaWRoc2RmZ2tqaHNkZmdramRzZnZzZGtmam5idnNvO2R
manZvO3NkZmJpdmhzZGZpbHVidjtvc2lkZmhidml1bHNlmO
Z2aXNiZGZpYmhzZG87ZmJvO3NkZ25iO29pLmR6Zgo=
</subject>
<attributes>
bwtakWRoc2RmZ2tqaHNkZmdramRzZnZzZGtmam5idnNvut4
arnZvO3NkZmJpdmhzZGZpbHVidjtvc2lkZmhidml1bHNkYm
Z2aXNiZGZpYmhzZG87ZmJvO3NkZ25iO29pLmC6Rhp=
</attributes>
</generate-certificate-signing-request>
</private-key>
</private-keys>
</keychain>
</action>
</rpc>
RESPONSE
--------
<rpc-reply message-id="101"
xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<certificate-signing-request
xmlns="urn:ietf:params:xml:ns:yang:ietf-system-keychain">
LS0tLS1CRUdJTiBDRVJUSUZJQ0FURS0tLS0tCk1JSUNrekNDQWZ5Z
0F3SUJBZ0lKQUpRT2t3bGpNK2pjTUEwR0NTcUdTSWIzRFFFQkJRVU
FNRFF4Q3pBSkJnTlYKQkFZVEFsVlRNUkF3RGdZRFZRUUtFd2RsZUd
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diR1V4RXpBUkJnTlZCQU1UQ2tOU1RDQkpjM04xWlhJd2daOHdEUVl
KS29aSWh2Y04KQVFFQkJRQURnWTBBTUlHSkFvR0JBTXVvZmFPNEV3
El1QWMrQ1RsTkNmc0d6cEw1Um5ydXZsOFRIcUJTdGZQY3N0Zk1KT1
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bXBDT2YKQWdNQkFBR2pnYXd3Z2Frd0hRWURWUjBPQkJZRUZKY1o2W
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SWHgzZjdVM2xZTgotLS0tLUVORCBDRVJUSUZJQ0FURS0tLS0tCg==
</certificate-signing-request>
</rpc-reply>
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.
<keychain xmlns="urn:ietf:params:xml:ns:yang:ietf-system-keychain">
<!-- private keys and associated certificates -->
<private-keys>
<private-key>
<name>tpm-protected-key</name>
<algorithm>sect571r1</algorithm>
<public-key>
cztvaWRoc2RmZ2tqaHNkZmdramRzZnZzZGtmam5idnNvO2RmanZvO3NkZ
mJpdmhzZGZpbHVidjtvc2lkZmhidml1bHNkYmZ2aXNiZGZpYmhzZG87Zm
JvO3NkZ25iO29pLmR6Zgo=
</public-key>
<certificate-chains>
<certificate-chain>
<name>default-idevid-chain</name>
<certificate>
diR1V4RXpBUkJnTlZCQU1UQ2tOU1RDQkpjM04xWlhJd2daOHdEUVl
LS0tLS1CRUdJTiBDRVJUSUZJQ0FURS0tLS0tCk1JSUNrekNDQWZ5Z
KS29aSWh2Y04KQVFFQkJRQURnWTBBTUlHSkFvR0JBTXVvZmFPNEV3
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SWM2xZTgotLS0tLUVORCBDRVJUSUZJQ0FURS0tLS0tCg==
</certificate>
<certificate>
KS29aSWh2Y04KQVFFQkJRQURnWTBBTUlHSkFvR0JBTXVvZmFPNEV3
El1QWMrQ1RsTkNmc0d6cEw1Um5ydXZsOFRIcUJTdGZQY3N0Zk1KT1
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bXBDT2YKQWdNQkFBR2pnYXd3Z2Frd0hRWURWUjBPQkJZRUZKY1o2W
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SSUZJQ0FURS0tLS0tCg==
</certificate>
</certificate-chain>
<certificate-chain>
<name>my-ldevid-chain</name>
<certificate>
0F3SUJBZ0lKQUpRT2t3bGpNK2pjTUEwR0NTcUdTSWIzRFFFQkJRVU
FNRFF4Q3pBSkJnTlYKQkFZVEFsVlRNUkF3RGdZRFZRUUtFd2RsZUd
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</certificate>
<certificate>
LS0tLS1CRUdJTiBDRVJUSUZJQ0FURS0tLS0tCk1JSUNrekNDQWZ5Z
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</certificate>
</certificate-chain>
</certificate-chains>
</private-key>
</private-keys>
<!-- trusted netconf/restconf client certificates -->
<trusted-certificates>
<name>explicitly-trusted-client-certs</name>
<description>
Specific client authentication certificates that are to be
explicitly trusted NETCONF/RESTCONF clients. These are
needed for client certificates not signed by our CA.
</description>
<trusted-certificate>
<name>George Jetson</name>
<certificate>
QmdOVkJBWVRBbFZUTVJBd0RnWURWUVFLRXdkbAplR0Z0Y0d4bE1RNHdEQ
MkF6a3hqUDlVQWtHR0dvS1U1eUc1SVR0Wm0vK3B0R2FieXVDMjBRd2kvZ
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WpiMjB2WlhoaGJYQnNaUzVqY215aU9LUTJNRFF4Q3pBSkJnTlZCQVlUQW
xWVE1SQXdEZ1lEVlFRSwpFd2RsZUdGdGNHeGxNUk13RVFZRFZRUURFd3B
EVWt3Z1NYTnpkV1Z5TUEwR0NTcUdTSWIzRFFFQkJRVUFBNEdCCkFFc3BK
WmdsK2gyTTg3QmtGMjhWbW1CdFFVaWc3OEgrRkYyRTFwdSt4ZVRJbVFFM
TQzcjFZSjk0M1FQLzV5eGUKN2QxMkxCV0dxUjUrbEl5N01YL21ka2M4al
zSFNwSDdwVXBCYnA4dmtNanFtZjJma3RqZHBxeFppUUtTbndWZTF2Zwot
LS0tLUVORCBDRVJUSUZJQ0FURS0tLS0tCg==
</certificate>
</trusted-certificate>
<trusted-certificate>
<name>Fred Flintstone</name>
<certificate>
VlEVlFRREV3Vm9ZWEJ3ZVRDQm56QU5CZ2txaGtpRzl3MEJBUUVGQUFPQm
pRQXdnWWtDCmdZRUE1RzRFSWZsS1p2bDlXTW44eUhyM2hObUFRaUhVUzV
rRUpPQy9hSFA3eGJXQW1ra054ZStUa2hrZnBsL3UKbVhsTjhSZUd1ODhG
NGcEk3UE90cnNFVjRwTUNBd0VBQWFPQ0FSSXdnZ0VPCk1CMEdBMVVkRGd
VEJiZ0JTWEdlbUEKMnhpRHVOTVkvVHFLNWd4cFJBZ1ZOYUU0cERZd05ER
V6QVJCZ05WQkFNVENrTlNUQ0JKYzNOMVpYS0NDUUNVRHBNSll6UG8zREF
NQmdOVkhSTUJBZjhFCkFqQUFNQTRHQTFVZER3RUIvd1FFQXdJSGdEQnBC
Z05WSFI4RVlqQmdNRjZnSXFBZ2hoNW9kSFJ3T2k4dlpYaGgKYlhCc1pTN
WpiMjB2WlhoaGJYQnNaUzVqY215aU9LUTJNRFF4Q3pBSkJnTlZCQVlUQW
xWVE1SQXdEZ1lEVlFRSwpFd2RsZUdGdGNHeGxNUk13RVFZRFZRUURFd3B
EVWt3Z1NYTnpkV1Z5TUEwR0NTcUdTSWIzRFFFQkJRVUFBNEdCCkFFc3BK
WmdsK2gyTTg3QmtGMjhWbW1CdFFVaWc3OEgrRkYyRTFwdSt4ZVRJbVFFM
lLQllsdWpOcjFTMnRLR05EMUc2OVJpK2FWNGw2NTdZNCtadVJMZgpRYjk
zSFNwSDdwVXBCYnA4dmtNanFtZjJma3RqZHBxeFppUUtTbndWZTF2Zwot
QWtUOCBDRVUUZJ0RUF==
</certificate>
</trusted-certificate>
</trusted-certificates>
<!-- trust anchors for netconf/restconf clients -->
<trusted-certificates>
<name>deployment-specific-ca-certs</name>
<description>
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.
</description>
<trusted-certificate>
<name>ca.example.com</name>
<certificate>
WmdsK2gyTTg3QmtGMjhWbW1CdFFVaWc3OEgrRkYyRTFwdSt4ZVRJbVFFM
lLQllsdWpOcjFTMnRLR05EMUc2OVJpK2FWNGw2NTdZNCtadVJMZgpRYjk
zSFNwSDdwVXBCYnA4dmtNanFtZjJma3RqZHBxeFppUUtTbndWZTF2Zwot
NGcEk3UE90cnNFVjRwTUNBd0VBQWFPQ0FSSXdnZ0VPCk1CMEdBMVVkRGd
VEJiZ0JTWEdlbUEKMnhpRHVOTVkvVHFLNWd4cFJBZ1ZOYUU0cERZd05ER
V6QVJCZ05WQkFNVENrTlNUQ0JKYzNOMVpYS0NDUUNVRHBNSll6UG8zREF
NQmdOVkhSTUJBZjhFCkFqQUFNQTRHQTFVZER3RUIvd1FFQXdJSGdEQnBC
Z05WSFI4RVlqQmdNRjZnSXFBZ2hoNW9kSFJ3T2k4dlpYaGgKYlhCc1pTN
WpiMjB2WlhoaGJYQnNaUzVqY215aU9LUTJNRFF4Q3pBSkJnTlZCQVlUQW
QmdOVkJBWVRBbFZUTVJBd0RnWURWUVFLRXdkbAplR0Z0Y0d4bE1RNHdEQ
MkF6a3hqUDlVQWtHR0dvS1U1eUc1SVR0Wm0vK3B0R2FieXVDMjBRd2kvZ
25PZnpZNEhONApXY0pTaUpZK2xtYWs3RTRORUZXZS9RdGp4NUlXZmdvN2
RJSUJQFRStS0Cg==
</certificate>
</trusted-certificate>
</trusted-certificates>
<!-- trust anchors for random HTTPS servers on Internet -->
<trusted-certificates>
<name>common-ca-certs</name>
<description>
Trusted certificates to authenticate common HTTPS servers.
These certificates are similar to those that might be
shipped with a web browser.
</description>
<trusted-certificate>
<name>ex-certificate-authority</name>
<certificate>
NGcEk3UE90cnNFVjRwTUNBd0VBQWFPQ0FSSXdnZ0VPCk1CMEdBMVVkRGd
VEJiZ0JTWEdlbUEKMnhpRHVOTVkvVHFLNWd4cFJBZ1ZOYUU0cERZd05ER
V6QVJCZ05WQkFNVENrTlNUQ0JKYzNOMVpYS0NDUUNVRHBNSll6UG8zREF
Z05WSFI4RVlqQmdNRjZnSXFBZ2hoNW9kSFJ3T2k4dlpYaGgKYlhCc1pTN
QmdOVkJBWVRBbFZUTVJBd0RnWURWUVFLRXdkbAplR0Z0Y0d4bE1RNHdEQ
MkF6a3hqUDlVQWtHR0dvS1U1eUc1SVR0Wm0vK3B0R2FieXVDMjBRd2kvZ
NQmdOVkhSTUJBZjhFCkFqQUFNQTRHQTFVZER3RUIvd1FFQXdJSGdEQnBC
WmdsK2gyTTg3QmtGMjhWbW1CdFFVaWc3OEgrRkYyRTFwdSt4ZVRJbVFFM
lLQllsdWpOcjFTMnRLR05EMUc2OVJpK2FWNGw2NTdZNCtadVJMZgpRYjk
zSFNwSDdwVXBCYnA4dmtNanFtZjJma3RqZHBxeFppUUtTbndWZTF2Zwot
25PZnpZNEhONApXY0pTaUpZK2xtYWs3RTRORUZXZS9RdGp4NUlXZmdvN2
WpiMjB2WlhoaGJYQnNaUzVqY215aU9L=
</certificate>
</trusted-certificate>
</trusted-certificates>
</keychain>
The following example illustrates a "certificate-expiration" notification in XML.
['\' line wrapping added for formatting only]
<notification
xmlns="urn:ietf:params:xml:ns:netconf:notification:1.0">
<eventTime>2016-07-08T00:01:00Z</eventTime>
<certificate-expiration
xmlns="urn:ietf:params:xml:ns:yang:ietf-system-keychain">
<certificate>
/kc:keychain/kc:private-keys/kc:private-key/kc:certificate-chains\
/kc:certificate-chain/kc:certificate[3]
</certificate>
<expiration-date>2016-08-08T14:18:53-05:00</expiration-date>
</certificate-expiration>
</notification>
This YANG module makes extensive use of data types defined in [RFC5280] and [RFC5958].
<CODE BEGINS> file "ietf-system-keychain@2016-03-16.yang"
module ietf-system-keychain {
yang-version 1.1;
namespace "urn:ietf:params:xml:ns:yang:ietf-system-keychain";
prefix "kc";
import ietf-yang-types { // RFC 6991
prefix yang;
}
organization
"IETF NETCONF (Network Configuration) Working Group";
contact
"WG Web: <http://tools.ietf.org/wg/netconf/>
WG List: <mailto:netconf@ietf.org>
WG Chair: Mehmet Ersue
<mailto:mehmet.ersue@nsn.com>
WG Chair: Mahesh Jethanandani
<mailto:mjethanandani@gmail.com>
Editor: Kent Watsen
<mailto:kwatsen@juniper.net>";
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 "2016-03-16" {
description
"Initial version";
reference
"RFC VVVV: NETCONF Server and RESTCONF Server Configuration
Models";
}
typedef algorithms {
type enumeration {
enum rsa { description "The RSA algorithm."; }
enum secp192r1 { description "The secp192r1 algorithm."; }
enum secp256r1 { description "The secp256r1 algorithm."; }
enum secp384r1 { description "The secp384r1 algorithm."; }
enum secp521r1 { description "The secp521r1 algorithm."; }
// what about ecdh_x25519 and ecdh_x448 in TLS 1.3?
}
description
"Asymmetric key algorithms. This list has been trimmed down
to the minimal subset of algorithms recommended by the IETF.
Please see the Design Consideration section in RFC VVVV for
more information about this.";
}
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 kc:algorithms;
config false;
description
"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 binary;
config false;
mandatory true;
description
"An OneAsymmetricKey 'publicKey' structure as specified
by RFC 5958, Section 2 encoded using the ASN.1
distinguished encoding rules (DER), as specified
in ITU-T X.690.";
reference
"RFC 5958:
Asymmetric Key Packages
ITU-T X.690:
Information technology – ASN.1 encoding rules:
Specification of Basic Encoding Rules (BER),
Canonical Encoding Rules (CER) and Distinguished
Encoding Rules (DER).";
}
container certificate-chains {
description
"Certificate chains associated with this private key.
More than one chain per key is enabled to support,
for instance, a TPM-protected key that has associated
both IDevID and LDevID certificates.";
list certificate-chain {
key name;
description
"A certificate chain for this public key.";
leaf name {
type string;
description
"An arbitrary name for the certificate chain.";
}
leaf-list certificate {
type binary;
ordered-by user;
description
"An X.509 v3 certificate structure as specified by RFC
5280, Section 4 encoded using the ASN.1 distinguished
encoding rules (DER), as specified in ITU-T X.690.
The list of certificates that run from the server
certificate towards the trust anchor. The chain MAY
include the trust anchor certificate itself.";
reference
"RFC 5280:
Internet X.509 Public Key Infrastructure Certificate
and Certificate Revocation List (CRL) Profile.
ITU-T X.690:
Information technology – ASN.1 encoding rules:
Specification of Basic Encoding Rules (BER),
Canonical Encoding Rules (CER) and Distinguished
Encoding Rules (DER).";
}
}
}
action generate-certificate-signing-request {
description
"Generates a certificate signing request structure for
the associated private key using the passed subject and
attribute values. Please review both the Security
Considerations and Design Considerations sections in
RFC VVVV for more information regarding this action
statement.";
input {
leaf subject {
type binary;
mandatory true;
description
"The 'subject' field from the CertificationRequestInfo
structure as specified by RFC 2986, Section 4.1 encoded
using the ASN.1 distinguished encoding rules (DER), as
specified in ITU-T X.690.";
reference
"RFC 2986:
PKCS #10: Certification Request Syntax Specification
Version 1.7.
ITU-T X.690:
Information technology – ASN.1 encoding rules:
Specification of Basic Encoding Rules (BER),
Canonical Encoding Rules (CER) and Distinguished
Encoding Rules (DER).";
}
leaf attributes {
type binary;
description
"The 'attributes' field from the CertificationRequestInfo
structure as specified by RFC 2986, Section 4.1 encoded
using the ASN.1 distinguished encoding rules (DER), as
specified in ITU-T X.690.";
reference
"RFC 2986:
PKCS #10: Certification Request Syntax Specification
Version 1.7.
ITU-T X.690:
Information technology – ASN.1 encoding rules:
Specification of Basic Encoding Rules (BER),
Canonical Encoding Rules (CER) and Distinguished
Encoding Rules (DER).";
}
}
output {
leaf certificate-signing-request {
type binary;
mandatory true;
description
"A CertificationRequest structure as specified by RFC
2986, Section 4.1 encoded using the ASN.1 distinguished
encoding rules (DER), as specified in ITU-T X.690.";
reference
"RFC 2986:
PKCS #10: Certification Request Syntax Specification
Version 1.7.
ITU-T X.690:
Information technology – ASN.1 encoding rules:
Specification of Basic Encoding Rules (BER),
Canonical Encoding Rules (CER) and Distinguished
Encoding Rules (DER).";
}
}
}
}
action generate-private-key {
description
"Requests the device to generate a private key using the
specified algorithm and key length.";
input {
leaf name {
type string;
mandatory true;
description
"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 key-usage {
type enumeration {
enum signing { description "signing"; }
enum encryption { description "encryption"; }
// unclear if these should be somehow more
// specific or varied.
}
description
"An optional parameter further restricting the use of
this key. Some algorithms inherently restrict use
(DH for signing) whereas others can support more than
one use (RSA). This flag forces the device to only
allow the key to be used for the indicated purposes.";
}
leaf algorithm {
type kc:algorithms;
mandatory true;
description
"The algorithm to be used when generating the key.";
}
leaf key-length {
type uint32;
description
"For algorithms that need a key length specified
when generating the key.";
}
}
}
action load-private-key {
description
"Requests the device to load a private key";
input {
leaf name {
type string;
mandatory true;
description
"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 private-key {
type binary;
mandatory true;
description
"An OneAsymmetricKey structure as specified by RFC
5958, Section 2 encoded using the ASN.1 distinguished
encoding rules (DER), as specified in ITU-T X.690.
Note that this is the raw private with no shrouding
to protect it. The strength of this private key
MUST NOT be greater than the strength of the secure
connection over which it is communicated. Devices
SHOULD fail this request if ever that happens.";
reference
"RFC 5958:
Asymmetric Key Packages
ITU-T X.690:
Information technology – ASN.1 encoding rules:
Specification of Basic Encoding Rules (BER),
Canonical Encoding Rules (CER) and Distinguished
Encoding Rules (DER).";
}
}
}
}
list trusted-certificates {
key name;
description
"A list of trusted certificates. Each list SHOULD be specific
to a purpose. For instance, there could be one list for
authenticating NETCONF/RESTCONF client certificates, and
another list for authenticating manufacturer-signed data,
and yet another list for authenticated web servers.";
leaf name {
type string;
description
"An arbitrary name for this list of trusted certificates.";
}
leaf description {
type string;
description
"An arbitrary description for this list of trusted
certificates.";
}
list trusted-certificate {
key name;
description
"A trusted certificate for a specific use.";
leaf name {
type string;
description
"An arbitrary name for this trusted certificate.";
}
leaf certificate {
type binary;
description
"An X.509 v3 certificate structure as specified by RFC
5280, Section 4 encoded using the ASN.1 distinguished
encoding rules (DER), as specified in ITU-T X.690.";
reference
"RFC 5280:
Internet X.509 Public Key Infrastructure Certificate
and Certificate Revocation List (CRL) Profile.
ITU-T X.690:
Information technology – ASN.1 encoding rules:
Specification of Basic Encoding Rules (BER),
Canonical Encoding Rules (CER) and Distinguished
Encoding Rules (DER).";
}
}
}
}
notification certificate-expiration {
description
"A notification indicating that a configured certificate is
either about to expire or has already expired. When to send
notifications is an implementation specific decision, but
it is RECOMMENDED that a notification be sent once a month
for 3 months, then once a week for four weeks, and then once
a day thereafter.";
leaf certificate {
type instance-identifier;
mandatory true;
description
"Identifies which certificate is expiring or is expired.";
}
leaf expiration-date {
type yang:date-and-time;
mandatory true;
description
"Identifies the expiration date on the certificate.";
}
}
}
<CODE ENDS>
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 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].
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/certificate-chains/certificate-chain/certificate {ssh-x509-cer
ts}?
+--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
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.
<listening-ssh-server
xmlns="urn:ietf:params:xml:ns:yang:ietf-ssh-server">
<port>830</port>
<host-keys>
<host-key>
<name>deployment-specific-certificate</name>
<certificate>ex-key-sect571r1-cert</certificate>
</host-key>
</host-keys>
</certificates>
<client-cert-auth>
<trusted-ca-certs>
deployment-specific-ca-certs
</trusted-ca-certs>
<trusted-client-certs>
explicitly-trusted-client-certs
</trusted-client-certs>
</client-cert-auth>
</listening-ssh-server>
This YANG module has a normative reference to [RFC4253].
<CODE BEGINS> file "ietf-ssh-server@2016-03-16.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-system-keychain {
prefix kc; // RFC VVVV
revision-date 2016-03-16;
}
organization
"IETF NETCONF (Network Configuration) Working Group";
contact
"WG Web: <http://tools.ietf.org/wg/netconf/>
WG List: <mailto:netconf@ietf.org>
WG Chair: Mehmet Ersue
<mailto:mehmet.ersue@nsn.com>
WG Chair: Mahesh Jethanandani
<mailto:mjethanandani@gmail.com>
Editor: Kent Watsen
<mailto:kwatsen@juniper.net>";
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 "2016-03-16" {
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.";
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 will use to
construct its ordered list of algorithms, when sending
its SSH_MSG_KEXINIT message, as defined in Section 7.1
of RFC 4253.";
reference
"RFC 4253: The Secure Shell (SSH) Transport Layer Protocol";
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 public key is actually identified by the name of
its cooresponding private-key in the keychain.";
}
leaf certificate {
if-feature ssh-x509-certs;
type leafref {
path "/kc:keychain/kc:private-keys/kc:private-key/"
+ "kc:certificate-chains/kc:certificate-chain/"
+ "kc:certificate";
}
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
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;
}
container listening-ssh-server {
description
"This container will be removed by the RFC Editor. This
container is currently only present in order to enable
the `pyang` tool to generate tree diagram output of this
module (used in the draft) as it otherwise would not
contain any protocol accessible nodes to output.";
uses listening-ssh-server-grouping;
}
}
<CODE ENDS>
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.
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.
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
ificate-chains/certificate-chain/certificate
+--rw client-auth
+--rw trusted-ca-certs? -> /kc:keychain/trusted-certific
ates/name
+--rw trusted-client-certs? -> /kc:keychain/trusted-certific
ates/name
<listening-tls-server
xmlns="urn:ietf:params:xml:ns:yang:ietf-tls-server">
<port>6513</port>
<certificates>
<certificate>
<name>ex-key-sect571r1-cert</name>
</certificate>
</certificates>
<client-auth>
<trusted-ca-certs>
deployment-specific-ca-certs
</trusted-ca-certs>
<trusted-client-certs>
explicitly-trusted-client-certs
</trusted-client-certs>
</client-auth>
</listening-tls-server>
<CODE BEGINS> file "ietf-tls-server@2016-03-16.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;
}
import ietf-system-keychain {
prefix kc; // RFC VVVV
revision-date 2016-03-16;
}
organization
"IETF NETCONF (Network Configuration) Working Group";
contact
"WG Web: <http://tools.ietf.org/wg/netconf/>
WG List: <mailto:netconf@ietf.org>
WG Chair: Mehmet Ersue
<mailto:mehmet.ersue@nsn.com>
WG Chair: Mahesh Jethanandani
<mailto:mjethanandani@gmail.com>
Editor: Kent Watsen
<mailto:kwatsen@juniper.net>";
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 "2016-03-16" {
description
"Initial version";
reference
"RFC VVVV: NETCONF Server and RESTCONF Server Configuration
Models";
}
// 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 in its Certificate message,
as defined in Section 7.4.2 in RRC 5246.";
reference
"RFC 5246:
The Transport Layer Security (TLS) Protocol Version 1.2";
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:certificate-chains/kc:certificate-chain/"
+ "kc:certificate";
}
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
"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;
}
container listening-tls-server {
description
"This container will be removed by the RFC Editor. This
container is currently only present in order to enable
the `pyang` tool to generate tree diagram output of this
module (used in the draft) as it otherwise would not
contain any protocol accessible nodes to output.";
uses listening-tls-server-grouping;
}
}
<CODE ENDS>
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.
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/certificate-chains/certificate-chain/certificat
e {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
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/certificate-chains/certificate-chain/certificate
| +--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/certificate-chains/certificate-chain/certificat
e {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
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/certificate-chains/certificate-chain/certificate
| +--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
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.
This example is consistent with other examples presented in this document.
<netconf-server
xmlns="urn:ietf:params:xml:ns:yang:ietf-netconf-server">
<listen>
<!-- listening for SSH connections -->
<endpoint>
<name>netconf/ssh</name>
<ssh>
<address>11.22.33.44</address>
<host-keys>
<host-key>
<public-key>my-rsa-key</public-key>
</host-key>
<host-key>
<certificate>TPM key</certificate>
</host-key>
</host-keys>
<client-cert-auth>
<trusted-ca-certs>
deployment-specific-ca-certs
</trusted-ca-certs>
<trusted-client-certs>
explicitly-trusted-client-certs
</trusted-client-certs>
</client-cert-auth>
</ssh>
</endpoint>
<!-- listening for TLS connections -->
<endpoint>
<name>netconf/tls</name>
<tls>
<address>11.22.33.44</address>
<certificates>
<certificate>ex-key-sect571r1-cert</certificate>
</certificates>
<client-auth>
<trusted-ca-certs>
deployment-specific-ca-certs
</trusted-ca-certs>
<trusted-client-certs>
explicitly-trusted-client-certs
</trusted-client-certs>
<cert-maps>
<cert-to-name>
<id>1</id>
<fingerprint>11:0A:05:11:00</fingerprint>
<map-type>x509c2n:san-any</map-type>
</cert-to-name>
<cert-to-name>
<id>2</id>
<fingerprint>B3:4F:A1:8C:54</fingerprint>
<map-type>x509c2n:specified</map-type>
<name>scooby-doo</name>
</cert-to-name>
</cert-maps>
</client-auth>
</tls>
</endpoint>
</listen>
<call-home>
<!-- calling home to an SSH-based NETCONF client -->
<netconf-client>
<name>config-mgr</name>
<ssh>
<endpoints>
<endpoint>
<name>east-data-center</name>
<address>11.22.33.44</address>
</endpoint>
<endpoint>
<name>west-data-center</name>
<address>55.66.77.88</address>
</endpoint>
</endpoints>
<host-keys>
<host-key>
<certificate>TPM key</certificate>
</host-key>
</host-keys>
<client-cert-auth>
<trusted-ca-certs>
deployment-specific-ca-certs
</trusted-ca-certs>
<trusted-client-certs>
explicitly-trusted-client-certs
</trusted-client-certs>
</client-cert-auth>
</ssh>
<connection-type>
<periodic>
<idle-timeout>300</idle-timeout>
<reconnect-timeout>60</reconnect-timeout>
</periodic>
</connection-type>
<reconnect-strategy>
<start-with>last-connected</start-with>
<max-attempts>3</max-attempts>
</reconnect-strategy>
</netconf-client>
<!-- calling home to a TLS-based NETCONF client -->
<netconf-client>
<name>event-correlator</name>
<tls>
<endpoints>
<endpoint>
<name>east-data-center</name>
<address>22.33.44.55</address>
</endpoint>
<endpoint>
<name>west-data-center</name>
<address>33.44.55.66</address>
</endpoint>
</endpoints>
<certificates>
<certificate>ex-key-sect571r1-cert</certificate>
</certificates>
<client-auth>
<trusted-ca-certs>
deployment-specific-ca-certs
</trusted-ca-certs>
<trusted-client-certs>
explicitly-trusted-client-certs
</trusted-client-certs>
<cert-maps>
<cert-to-name>
<id>1</id>
<fingerprint>11:0A:05:11:00</fingerprint>
<map-type>x509c2n:san-any</map-type>
</cert-to-name>
<cert-to-name>
<id>2</id>
<fingerprint>B3:4F:A1:8C:54</fingerprint>
<map-type>x509c2n:specified</map-type>
<name>scooby-doo</name>
</cert-to-name>
</cert-maps>
</client-auth>
</tls>
<connection-type>
<persistent>
<idle-timeout>300</idle-timeout>
<keep-alives>
<max-wait>30</max-wait>
<max-attempts>3</max-attempts>
</keep-alives>
</persistent>
</connection-type>
<reconnect-strategy>
<start-with>first-listed</start-with>
<max-attempts>3</max-attempts>
</reconnect-strategy>
</netconf-client>
</call-home>
</netconf-server>
This YANG module imports YANG types from [RFC6991] and [RFC7407].
<CODE BEGINS> file "ietf-netconf-server@2016-03-16.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 2016-03-16;
}
import ietf-tls-server { // RFC VVVV
prefix ts;
revision-date 2016-03-16;
}
organization
"IETF NETCONF (Network Configuration) Working Group";
contact
"WG Web: <http://tools.ietf.org/wg/netconf/>
WG List: <mailto:netconf@ietf.org>
WG Chair: Mehmet Ersue
<mailto:mehmet.ersue@nsn.com>
WG Chair: Mahesh Jethanandani
<mailto:mjethanandani@gmail.com>
Editor: Kent Watsen
<mailto:kwatsen@juniper.net>";
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 "2016-03-16" {
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
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 7589: 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
"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.";
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";
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;
}
}
}
}
}
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;
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;
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;
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.";
}
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.";
}
}
}
}
}
<CODE ENDS>
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.
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
+--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/certificate-chains/certificate-chain/certificate
| +--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/certificate-chains/certificate-chain/certificate
| +--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 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
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.
<restconf-server
xmlns="urn:ietf:params:xml:ns:yang:ietf-restconf-server">
<!-- listening for TLS (HTTPS) connections -->
<listen>
<endpoint>
<name>netconf/tls</name>
<tls>
<address>11.22.33.44</address>
<certificates>
<certificate>ex-key-sect571r1-cert</certificate>
</certificates>
<client-auth>
<trusted-ca-certs>
deployment-specific-ca-certs
</trusted-ca-certs>
<trusted-client-certs>
explicitly-trusted-client-certs
</trusted-client-certs>
<cert-maps>
<cert-to-name>
<id>1</id>
<fingerprint>11:0A:05:11:00</fingerprint>
<map-type>x509c2n:san-any</map-type>
</cert-to-name>
<cert-to-name>
<id>2</id>
<fingerprint>B3:4F:A1:8C:54</fingerprint>
<map-type>x509c2n:specified</map-type>
<name>scooby-doo</name>
</cert-to-name>
</cert-maps>
</client-auth>
</tls>
</endpoint>
</listen>
<!-- calling home to a RESTCONF client -->
<call-home>
<restconf-client>
<name>config-manager</name>
<tls>
<endpoints>
<endpoint>
<name>east-data-center</name>
<address>22.33.44.55</address>
</endpoint>
<endpoint>
<name>west-data-center</name>
<address>33.44.55.66</address>
</endpoint>
</endpoints>
<certificates>
<certificate>ex-key-sect571r1-cert</certificate>
</certificates>
<client-auth>
<trusted-ca-certs>
deployment-specific-ca-certs
</trusted-ca-certs>
<trusted-client-certs>
explicitly-trusted-client-certs
</trusted-client-certs>
<cert-maps>
<cert-to-name>
<id>1</id>
<fingerprint>11:0A:05:11:00</fingerprint>
<map-type>x509c2n:san-any</map-type>
</cert-to-name>
<cert-to-name>
<id>2</id>
<fingerprint>B3:4F:A1:8C:54</fingerprint>
<map-type>x509c2n:specified</map-type>
<name>scooby-doo</name>
</cert-to-name>
</cert-maps>
</client-auth>
</tls>
<connection-type>
<periodic>
<idle-timeout>300</idle-timeout>
<reconnect-timeout>60</reconnect-timeout>
</periodic>
</connection-type>
<reconnect-strategy>
<start-with>last-connected</start-with>
<max-attempts>3</max-attempts>
</reconnect-strategy>
</restconf-client>
</call-home>
</restconf-server>
This YANG module imports YANG types from [RFC6991] and [RFC7407].
<CODE BEGINS> file "ietf-restconf-server@2016-03-16.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 2016-03-16;
}
organization
"IETF NETCONF (Network Configuration) Working Group";
contact
"WG Web: <http://tools.ietf.org/wg/netconf/>
WG List: <mailto:netconf@ietf.org>
WG Chair: Mehmet Ersue
<mailto:mehmet.ersue@nsn.com>
WG Chair: Mahesh Jethanandani
<mailto:mjethanandani@gmail.com>
Editor: Kent Watsen
<mailto:kwatsen@juniper.net>";
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 "2016-03-16" {
description
"Initial version";
reference
"RFC VVVV: NETCONF Server and RESTCONF Server Configuration
Models";
}
// Features
feature tls-listen {
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;
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 {
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,
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).";
}
}
}
}
}
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).";
}
}
}
}
}
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
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.";
}
}
}
}
}
<CODE ENDS>
The manner that the both local and remote endpoints have been specified in the ietf-netconf-server and ietf-rest-server modules does not directly support virtual routing and forwarding (VRF), though they have been specified in such a way to enable external modules will augment in VRF designations when needed.
This document uses PKCS #10 [RFC2986] for the "generate-certificate-signing-request" action. The use of Certificate Request Message Format (CRMF) [RFC4211] was considered, but is was unclear if there was market demand for it, and so support for CRMF has been left out of this specification. If it is desired to support CRMF in the future, placing a "choice" statement in both the input and output statements, along with an "if-feature" statement on the CRMF option, would enable a backwards compatible solution.
This document puts a limit of the number of elliptical curves supported. This was done to match industry trends in IETF best practice (e.g., matching work being done in TLS 1.3). In additional algorithms are needed, they MAY be augmented in by another module, or added directly in a future version of this document.
Both this document and Key Chain YANG Data Model [draft-ietf-rtgwg-yang-key-chain] define keychain YANG modules. The authors looked at this and agree that they two modules server different purposes and hence not worth merging into one document. To underscore this further, this document renamed its module from "ietf-keychain" to "ietf-system-keychain" and that other document renamed its module from "ietf-key-chain" to "ietf-routing-key-chain".
For the trusted-certificates list, Trust Anchor Format [RFC5914] was evaluated and deemed inappropriate due to this document's need to also support pinning. That is, pinning a client-certificate to support NETCONF over TLS client authentication.
This document defines a keychain mechanism that is entrusted with the safe keeping of private keys, and the safe keeping of trusted certificates. Nowhere in this API is there an ability to access (read out) a private key once it is known to the keychain. Further, associated public keys and attributes (e.g., algorithm name, key length, etc.) are read-only. That said, this document allows for the deletion of private keys and their certificates, as well the deletion of trusted certificates. Access control mechanisms (e.g., NACM [RFC6536]) MUST be in place so as to authorize such client actions. Further, whilst the data model allows for private keys and trusted certificates in general to be deleted, implementations should be well aware that some privates keys (e.g., those in a TPM) and some trusted certificates, should never be deleted, regardless if the authorization mechanisms would generally allow for such actions.
For the "generate-certificate-signing-request" action, it is RECOMMENDED that devices implement assert channel binding [RFC5056], so as to ensure that the application layer that sent the request is the same as the device authenticated in the secure transport layer was established.
This document defines a data model that includes a list of private keys. These private keys MAY be deleted using standard NETCONF or RESTCONF operations (e.g., <edit-config>). Implementations SHOULD automatically (without explicit request) zeroize these keys in the most secure manner available, so as to prevent the remnants of their persisted storage locations from being analyzed in any meaningful way.
The keychain module define within this document defines the "load-private-key" action enabling a device to load a client-supplied private key. This is a private key with no shrouding to protect it. The strength of this private key MUST NOT be greater than the strength of the underlying secure transport connection over which it is communicated. Devices SHOULD fail this request if ever the strength of the private key is greater then the strength of the underlying transport.
A denial of service (DoS) attack MAY occur if the NETCONF server limits the maximum number of NETCONF sessions it will accept (i.e. the 'max-sessions' field in the ietf-netconf-server module is not zero) and either the "hello-timeout" or "idle-timeout" fields in ietf-netconf-server module have been set to indicate the NETCONF server should wait forever (i.e. set to zero).
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 five YANG modules in the YANG Module Names registry [RFC6020]. Following the format in [RFC6020], the the following registrations are requested:
name: ietf-system-keychain namespace: urn:ietf:params:xml:ns:yang:ietf-system-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
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, Sean Turner, 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.
| [draft-ietf-rtgwg-yang-key-chain] | Lindem, A., Qu, Y., Yeung, D., Chen, I., Zhang, J. and Y. Yang, "Key Chain YANG Data Model", Internet-Draft draft-ietf-rtgwg-yang-key-chain, 2016. |
| [RFC3688] | Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688, DOI 10.17487/RFC3688, January 2004. |
| [RFC4211] | Schaad, J., "Internet X.509 Public Key Infrastructure Certificate Request Message Format (CRMF)", RFC 4211, DOI 10.17487/RFC4211, September 2005. |
| [RFC5056] | Williams, N., "On the Use of Channel Bindings to Secure Channels", RFC 5056, DOI 10.17487/RFC5056, November 2007. |
| [RFC5914] | Housley, R., Ashmore, S. and C. Wallace, "Trust Anchor Format", RFC 5914, DOI 10.17487/RFC5914, June 2010. |
| [RFC6536] | Bierman, A. and M. Bjorklund, "Network Configuration Protocol (NETCONF) Access Control Model", RFC 6536, DOI 10.17487/RFC6536, March 2012. |
Please see: https://github.com/netconf-wg/server-model/issues.