| NETCONF Working Group | K. Watsen |
| Internet-Draft | Juniper Networks |
| Intended status: Standards Track | G. Wu |
| Expires: December 6, 2018 | Cisco Networks |
| June 4, 2018 |
RESTCONF Client and Server Models
draft-ietf-netconf-restconf-client-server-06
This document defines two YANG modules, one module to configure a RESTCONF client and the other module to configure a RESTCONF server. Both modules support the TLS transport protocol with both standard RESTCONF and RESTCONF Call Home connections.
This draft contains many placeholder values that need to be replaced with finalized values at the time of publication. This note summarizes all of the substitutions that are needed. No other RFC Editor instructions are specified elsewhere in this document.
This document contains references to other drafts in progress, both in the Normative References section, as well as in body text throughout. Please update the following references to reflect their final RFC assignments:
Artwork in this document contains shorthand references to drafts in progress. 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 Appendix section is to be removed prior to publication:
This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet-Drafts is at https://datatracker.ietf.org/drafts/current/.
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Copyright (c) 2018 IETF Trust and the persons identified as the document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (https://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License.
This document defines two YANG [RFC7950] modules, one module to configure a RESTCONF client and the other module to configure a RESTCONF server [RFC8040]. Both modules support the TLS [RFC5246] transport protocol with both standard RESTCONF and RESTCONF Call Home connections [RFC8071].
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all capitals, as shown here.
The RESTCONF client model presented in this section supports both clients initiating connections to servers, as well as clients listening for connections from servers calling home.
This model, like that presented in [I-D.ietf-netconf-netconf-client-server], is designed to support any number of possible transports. RESTCONF only supports the TLS transport currently, thus this model only supports the TLS transport.
All private keys and trusted certificates are held in the keystore model defined in [I-D.ietf-netconf-keystore].
YANG feature statements are used to enable implementations to advertise which parts of the model the RESTCONF client supports.
The following tree diagram [RFC8340] provides an overview of the data model for the "ietf-restconf-client" module. Just the container is displayed below, but there is also a reuable grouping by the same name that the container is using.
[Note: '\' line wrapping for formatting only]
module: ietf-restconf-client
+--rw restconf-client
+--rw initiate! {initiate}?
| +--rw restconf-server* [name]
| +--rw name string
| +--rw endpoints
| +--rw endpoint* [name]
| +--rw name string
| +--rw (transport)
| | +--:(tls) {tls-initiate}?
| | +--rw tls
| | +--rw address inet:host
| | +--rw port? inet:port-number
| | +--rw client-identity
| | | +--rw (auth-type)
| | | +--:(certificate)
| | | +--rw certificate
| | | +--rw (local-or-keystore)
| | | +--:(local)
| | | | +--rw algorithm
| | | | | ct:key-algorithm\
-ref
| | | | +--rw public-key
| | | | | binary
| | | | +--rw private-key
| | | | | union
| | | | +--rw cert
| | | | | ct:end-entity-ce\
rt-cms
| | | | +---n certificate-expira\
tion
| | | | +-- expiration-date?
| | | | yang:date-and\
-time
| | | +--:(keystore)
| | | {keystore-implemen\
ted}?
| | | +--rw reference
| | | ks:asymmetric-ke\
y-certificate-ref
| | +--rw server-auth
| | | +--rw pinned-ca-certs?
| | | | ta:pinned-certificates-ref
| | | +--rw pinned-server-certs?
| | | ta:pinned-certificates-ref
| | +--rw hello-params
| | {tls-client-hello-params-config}?
| | +--rw tls-versions
| | | +--rw tls-version* identityref
| | +--rw cipher-suites
| | +--rw cipher-suite* identityref
| +--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
+--rw listen! {listen}?
+--rw idle-timeout? 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 client-identity
| +--rw (auth-type)
| +--:(certificate)
| +--rw certificate
| +--rw (local-or-keystore)
| +--:(local)
| | +--rw algorithm
| | | ct:key-algorithm-ref
| | +--rw public-key
| | | binary
| | +--rw private-key
| | | union
| | +--rw cert
| | | ct:end-entity-cert-cms\
| | +---n certificate-expiration
| | +-- expiration-date?
| | yang:date-and-time
| +--:(keystore)
| {keystore-implemented}?
| +--rw reference
| ks:asymmetric-key-cert\
ificate-ref
+--rw server-auth
| +--rw pinned-ca-certs?
| | ta:pinned-certificates-ref
| +--rw pinned-server-certs?
| ta:pinned-certificates-ref
+--rw hello-params
{tls-client-hello-params-config}?
+--rw tls-versions
| +--rw tls-version* identityref
+--rw cipher-suites
+--rw cipher-suite* identityref
The following example illustrates configuring a RESTCONF client to initiate connections, as well as listening for call-home connections.
This example is consistent with the examples presented in Section 2.2 of [I-D.ietf-netconf-keystore].
[Note: '\' line wrapping for formatting only]
<restconf-client
xmlns="urn:ietf:params:xml:ns:yang:ietf-restconf-client">
<!-- RESTCONF servers to initiate connections to -->
<initiate>
<restconf-server>
<name>corp-fw1</name>
<endpoints>
<endpoint>
<name>corp-fw1.example.com</name>
<tls>
<address>corp-fw1.example.com</address>
<client-identity>
<certificate>
<algorithm xmlns:ct="urn:ietf:params:xml:ns:yang:i\
etf-crypto-types">ct:secp521r1</algorithm>
<private-key>base64encodedvalue==</private-key>
<public-key>base64encodedvalue==</public-key>
<cert>base64encodedvalue==</cert>
</certificate>
</client-identity>
<server-auth>
<pinned-ca-certs>explicitly-trusted-server-ca-certs<\
/pinned-ca-certs>
<pinned-server-certs>explicitly-trusted-server-certs\
</pinned-server-certs>
</server-auth>
</tls>
</endpoint>
<endpoint>
<name>corp-fw2.example.com</name>
<tls>
<address>corp-fw2.example.com</address>
<client-identity>
<certificate>
<algorithm xmlns:ct="urn:ietf:params:xml:ns:yang:i\
etf-crypto-types">ct:secp521r1</algorithm>
<private-key>base64encodedvalue==</private-key>
<public-key>base64encodedvalue==</public-key>
<cert>base64encodedvalue==</cert>
</certificate>
</client-identity>
<server-auth>
<pinned-ca-certs>explicitly-trusted-server-ca-certs<\
/pinned-ca-certs>
<pinned-server-certs>explicitly-trusted-server-certs\
</pinned-server-certs>
</server-auth>
</tls>
</endpoint>
</endpoints>
</restconf-server>
</initiate>
<!-- endpoints to listen for RESTCONF Call Home connections on -->\
<listen>
<endpoint>
<name>Intranet-facing listener</name>
<tls>
<address>11.22.33.44</address>
<client-identity>
<certificate>
<algorithm xmlns:ct="urn:ietf:params:xml:ns:yang:ietf-cr\
ypto-types">ct:secp521r1</algorithm>
<private-key>base64encodedvalue==</private-key>
<public-key>base64encodedvalue==</public-key>
<cert>base64encodedvalue==</cert>
</certificate>
</client-identity>
<server-auth>
<pinned-ca-certs>explicitly-trusted-server-ca-certs</pinne\
d-ca-certs>
<pinned-server-certs>explicitly-trusted-server-certs</pinn\
ed-server-certs>
</server-auth>
</tls>
</endpoint>
</listen>
</restconf-client>
This YANG module has normative references to [RFC6991], [RFC8040], and [RFC8071], and [I-D.ietf-netconf-tls-client-server].
<CODE BEGINS> file "ietf-restconf-client@2018-06-04.yang"
module ietf-restconf-client {
yang-version 1.1;
namespace "urn:ietf:params:xml:ns:yang:ietf-restconf-client";
prefix "rcc";
import ietf-inet-types {
prefix inet;
reference
"RFC 6991: Common YANG Data Types";
}
import ietf-tls-client {
prefix ts;
revision-date 2018-06-04; // stable grouping definitions
reference
"RFC ZZZZ: YANG Groupings for TLS Clients and TLS Servers";
}
organization
"IETF NETCONF (Network Configuration) Working Group";
contact
"WG Web: <http://datatracker.ietf.org/wg/restconf/>
WG List: <mailto:restconf@ietf.org>
Author: Kent Watsen
<mailto:kwatsen@juniper.net>
Author: Gary Wu
<mailto:garywu@cisco.com>";
description
"This module contains a collection of YANG definitions for
configuring RESTCONF clients.
Copyright (c) 2017 IETF Trust and the persons identified as
authors of the code. All rights reserved.
Redistribution and use in source and binary forms, with or
without modification, is permitted pursuant to, and subject
to the license terms contained in, the Simplified BSD
License set forth in Section 4.c of the IETF Trust's
Legal Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info).
This version of this YANG module is part of RFC XXXX; see
the RFC itself for full legal notices.";
revision "2018-06-04" {
description
"Initial version";
reference
"RFC XXXX: RESTCONF Client and Server Models";
}
// Features
feature initiate {
description
"The 'initiate' feature indicates that the RESTCONF client
supports initiating RESTCONF connections to RESTCONF servers
using at least one transport (e.g., TLS, etc.).";
}
feature tls-initiate {
if-feature initiate;
description
"The ‘tls-initiate’ feature indicates that the RESTCONF client
supports initiating TLS connections to RESTCONF servers. This
feature exists as TLS might not be a mandatory to implement
transport in the future.";
reference
"RFC 8040: RESTCONF Protocol";
}
feature listen {
description
"The 'listen' feature indicates that the RESTCONF client
supports opening a port to accept RESTCONF server call
home connections using at least one transport (e.g.,
TLS, etc.).";
}
feature tls-listen {
if-feature listen;
description
"The ‘tls-listen’ feature indicates that the RESTCONF client
supports opening a port to listen for incoming RESTCONF
server call-home TLS connections. This feature exists as
TLS might not be a mandatory to implement transport in the
future.";
reference
"RFC 8071: NETCONF Call Home and RESTCONF Call Home";
}
container restconf-client {
uses restconf-client;
description
"Top-level container for RESTCONF client configuration.";
}
grouping restconf-client {
description
"Top-level grouping for RESTCONF client configuration.";
container initiate {
if-feature initiate;
presence "Enables client to initiate TCP connections";
description
"Configures client initiating underlying TCP connections.";
list restconf-server {
key name;
min-elements 1;
description
"List of RESTCONF servers the RESTCONF client is to
initiate connections to in parallel.";
leaf name {
type string;
description
"An arbitrary name for the RESTCONF server.";
}
container endpoints {
description
"Container for the list of endpoints.";
list endpoint {
key name;
min-elements 1;
ordered-by user;
description
"A non-empty user-ordered list of endpoints for this
RESTCONF client to try to connect to in sequence.
Defining more than one enables high-availability.";
leaf name {
type string;
description
"An arbitrary name for this endpoint.";
}
choice transport {
mandatory true;
description
"Selects between available transports. This is a
'choice' statement so as to support additional
transport options to be augmented in.";
case tls {
if-feature tls-initiate;
container tls {
description
"Specifies TLS-specific transport
configuration.";
leaf address {
type inet:host;
mandatory true;
description
"The IP address or hostname of the endpoint.
If a domain name is configured, then the
DNS resolution should happen on each usage
attempt. If the the DNS resolution results
in multiple IP addresses, the IP addresses
will be tried according to local preference
order until a connection has been established
or until all IP addresses have failed.";
}
leaf port {
type inet:port-number;
default 443;
description
"The IP port for this endpoint. The RESTCONF
client will use the IANA-assigned well-known
port for 'https' (443) if no value is
specified.";
}
uses ts:tls-client-grouping {
refine "client-identity/auth-type" {
mandatory true;
description
"RESTCONF clients MUST pass some
authentication credentials.";
}
}
}
} // end tls
} // end transport
container connection-type {
description
"Indicates the kind of connection to use.";
choice connection-type {
default persistent-connection;
description
"Selects between available connection types.";
case persistent-connection {
container persistent {
presence
"Indicates that a persistent connection is
to be maintained.";
description
"Maintain a persistent connection to the
RESTCONF server. If the connection goes down,
immediately start trying to reconnect to it,
using the reconnection strategy. This
connection type minimizes any RESTCONF server
to RESTCONF client data-transfer delay, albeit
at the expense of holding resources longer.";
leaf idle-timeout {
type uint32;
units "seconds";
default 86400; // one day;
description
"Specifies the maximum number of seconds
that the underlying TLS session may remain
idle. A TLS session will be dropped if it
is idle for an interval longer than this
number of seconds. If set to zero, then
the client 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 TLS
server. An unresponsive TLS server will
be dropped after approximately max-attempts
* max-wait seconds.";
reference
"RFC 8071: 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 server, a TLS-level message will
be sent to test the aliveness of the TLS
server.";
}
leaf max-attempts {
type uint8;
default 3;
description
"Sets the maximum number of sequential
keep-alive messages that can fail to
obtain a response from the TLS server
before assuming the TLS server is no
longer alive.";
}
}
}
}
case periodic-connection {
container periodic {
presence
"Indicates that a periodic connection is to be
maintained.";
description
"Periodically connect to the RESTCONF server,
so that, e.g., the RESTCONF client can
collect data (logs) from the RESTCONF server.
Once the connection is closed, for whatever
reason, the RESTCONF client will restart its
timer until the next connection.";
leaf idle-timeout {
type uint16;
units "seconds";
default 300; // five minutes
description
"Specifies the maximum number of seconds
that the underlying TLS session may remain
idle. A TLS 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.";
}
leaf reconnect-timeout {
type uint16 {
range "1..max";
}
units minutes;
default 60;
description
"Sets the maximum amount of unconnected time
the RESTCONF client will wait before re-
establishing a connection to the RESTCONF
server. The RESTCONF client may initiate
a connection before this time if desired
(e.g., to set configuration).";
}
}
} // end periodic-connection
} // end connection-type
} // end connection-type
container reconnect-strategy {
description
"The reconnection strategy directs how a RESTCONF
client reconnects to a RESTCONF server, after
discovering its connection to the server has
dropped, even if due to a reboot. The RESTCONF
client starts with the specified endpoint and
tries to connect to it max-attempts times before
trying the next endpoint in the list (round
robin).";
leaf start-with {
type enumeration {
enum first-listed {
description
"Indicates that reconnections should start
with the first endpoint listed.";
}
enum last-connected {
description
"Indicates that reconnections should start
with the endpoint last connected to. If
no previous connection has ever been
established, then the first endpoint
configured is used. RESTCONF clients
SHOULD be able to remember the last
endpoint connected to across reboots.";
}
}
default first-listed;
description
"Specifies which of the RESTCONF server's
endpoints the RESTCONF client should start
with when trying to connect to the RESTCONF
server.";
}
leaf max-attempts {
type uint8 {
range "1..max";
}
default 3;
description
"Specifies the number times the RESTCONF client
tries to connect to a specific endpoint before
moving on to the next endpoint in the list
(round robin).";
}
} // end reconnect-strategy
} // end endpoint
} // end endpoints
} // end restconf-server
} // end initiate
container listen {
if-feature listen;
presence "Enables client to accept call-home connections";
description
"Configures client accepting call-home TCP connections.";
leaf idle-timeout {
type uint16;
units "seconds";
default 3600; // one hour
description
"Specifies the maximum number of seconds that an
underlying TLS session may remain idle. A TLS session
will be dropped if it is idle for an interval longer
than this number of seconds. If set to zero, then
the server will never drop a session because it is
idle. Sessions that have a notification subscription
active are never dropped.";
}
list endpoint {
key name;
min-elements 1;
description
"List of endpoints to listen for RESTCONF connections.";
leaf name {
type string;
description
"An arbitrary name for the RESTCONF listen endpoint.";
}
choice transport {
mandatory true;
description
"Selects between available transports. This is a
'choice' statement so as to support additional
transport options to be augmented in.";
case tls {
if-feature tls-listen;
container tls {
description
"TLS-specific listening configuration for inbound
connections.";
leaf address {
type inet:ip-address;
description
"The IP address to listen on for incoming call-
home connections. The RESTCONF client will
listen on all configured interfaces if no
value is specified. INADDR_ANY (0.0.0.0) or
INADDR6_ANY (0:0:0:0:0:0:0:0 a.k.a. ::) MUST
be used when the server is to listen on all
IPv4 or IPv6 addresses, respectively.";
}
leaf port {
type inet:port-number;
default 4336;
description
"The port number to listen on for call-home
connections. The RESTCONF client will listen
on the IANA-assigned well-known port for
'restconf-ch-tls' (4336) if no value is
specified.";
}
uses ts:tls-client-grouping {
refine "client-identity/auth-type" {
mandatory true;
description
"RESTCONF clients MUST pass some authentication
credentials.";
}
}
}
}
} // end transport
} // end endpoint
} // end listen
} // end restconf-client
}
<CODE ENDS>
The RESTCONF server model presented in this section supports servers both listening for connections as well as initiating call-home connections.
All private keys and trusted certificates are held in the keystore model defined in [I-D.ietf-netconf-keystore].
YANG feature statements are used to enable implementations to advertise which parts of the model the RESTCONF server supports.
The following tree diagram [RFC8340] provides an overview of the data model for the "ietf-restconf-client" module. Just the container is displayed below, but there is also a reuable grouping by the same name that the container is using.
[Note: '\' line wrapping for formatting only]
module: ietf-restconf-server
+--rw restconf-server
+--rw listen! {listen}?
| +--rw endpoint* [name]
| +--rw name string
| +--rw (transport)
| +--:(tls) {tls-listen}?
| +--rw tls
| +--rw address? inet:ip-address
| +--rw port? inet:port-number
| +--rw server-identity
| | +--rw (local-or-keystore)
| | +--:(local)
| | | +--rw algorithm
| | | | ct:key-algorithm-ref
| | | +--rw public-key binary
| | | +--rw private-key union
| | | +--rw cert
| | | | ct:end-entity-cert-cms
| | | +---n certificate-expiration
| | | +-- expiration-date?
| | | yang:date-and-time
| | +--:(keystore) {keystore-implemented}?
| | +--rw reference
| | ks:asymmetric-key-certificate-r\
ef
| +--rw client-auth
| | +--rw pinned-ca-certs?
| | | ta:pinned-certificates-ref
| | +--rw pinned-client-certs?
| | | ta:pinned-certificates-ref
| | +--rw cert-maps
| | +--rw cert-to-name* [id]
| | +--rw id uint32
| | +--rw fingerprint
| | | x509c2n:tls-fingerprint
| | +--rw map-type identityref
| | +--rw name string
| +--rw hello-params
| {tls-server-hello-params-config}?
| +--rw tls-versions
| | +--rw tls-version* identityref
| +--rw cipher-suites
| +--rw cipher-suite* identityref
+--rw call-home! {call-home}?
+--rw restconf-client* [name]
+--rw name string
+--rw endpoints
| +--rw endpoint* [name]
| +--rw name string
| +--rw (transport)
| +--:(tls) {tls-call-home}?
| +--rw tls
| +--rw address inet:host
| +--rw port? inet:port-number
| +--rw server-identity
| | +--rw (local-or-keystore)
| | +--:(local)
| | | +--rw algorithm
| | | | ct:key-algorithm-ref
| | | +--rw public-key
| | | | binary
| | | +--rw private-key
| | | | union
| | | +--rw cert
| | | | ct:end-entity-cert-cms
| | | +---n certificate-expiration
| | | +-- expiration-date?
| | | yang:date-and-time
| | +--:(keystore) {keystore-implemented\
}?
| | +--rw reference
| | ks:asymmetric-key-certifi\
cate-ref
| +--rw client-auth
| | +--rw pinned-ca-certs?
| | | ta:pinned-certificates-ref
| | +--rw pinned-client-certs?
| | | ta:pinned-certificates-ref
| | +--rw cert-maps
| | +--rw cert-to-name* [id]
| | +--rw id uint32
| | +--rw fingerprint
| | | x509c2n:tls-fingerprint
| | +--rw map-type identityref
| | +--rw name string
| +--rw hello-params
| {tls-server-hello-params-config}?
| +--rw tls-versions
| | +--rw tls-version* identityref
| +--rw cipher-suites
| +--rw cipher-suite* identityref
+--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
The following example illustrates configuring a RESTCONF server to listen for RESTCONF client connections, as well as configuring call-home to one RESTCONF client.
This example is consistent with the examples presented in Section 2.2 of [I-D.ietf-netconf-keystore].
[Note: '\' line wrapping for formatting only]
<restconf-server
xmlns="urn:ietf:params:xml:ns:yang:ietf-restconf-server"
xmlns:x509c2n="urn:ietf:params:xml:ns:yang:ietf-x509-cert-to-name"\
>
<!-- endpoints to listen for RESTCONF connections on -->
<listen>
<endpoint>
<name>netconf/tls</name>
<tls>
<address>11.22.33.44</address>
<server-identity>
<algorithm xmlns:ct="urn:ietf:params:xml:ns:yang:ietf-cryp\
to-types">ct:secp521r1</algorithm>
<private-key>base64encodedvalue==</private-key>
<public-key>base64encodedvalue==</public-key>
<cert>base64encodedvalue==</cert>
</server-identity>
<client-auth>
<pinned-ca-certs>explicitly-trusted-client-ca-certs</pinne\
d-ca-certs>
<pinned-client-certs>explicitly-trusted-client-certs</pinn\
ed-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 to a RESTCONF client with two endpoints -->
<call-home>
<restconf-client>
<name>config-manager</name>
<endpoints>
<endpoint>
<name>east-data-center</name>
<tls>
<address>22.33.44.55</address>
<server-identity>
<algorithm xmlns:ct="urn:ietf:params:xml:ns:yang:ietf-\
crypto-types">ct:secp521r1</algorithm>
<private-key>base64encodedvalue==</private-key>
<public-key>base64encodedvalue==</public-key>
<cert>base64encodedvalue==</cert>
</server-identity>
<client-auth>
<pinned-ca-certs>explicitly-trusted-client-ca-certs</p\
inned-ca-certs>
<pinned-client-certs>explicitly-trusted-client-certs</\
pinned-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>
<endpoint>
<name>west-data-center</name>
<tls>
<address>33.44.55.66</address>
<server-identity>
<algorithm xmlns:ct="urn:ietf:params:xml:ns:yang:ietf-\
crypto-types">ct:secp521r1</algorithm>
<private-key>base64encodedvalue==</private-key>
<public-key>base64encodedvalue==</public-key>
<cert>base64encodedvalue==</cert>
</server-identity>
<client-auth>
<pinned-ca-certs>explicitly-trusted-client-ca-certs</p\
inned-ca-certs>
<pinned-client-certs>explicitly-trusted-client-certs</\
pinned-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>
</endpoints>
<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 has normative references to [RFC6991], [RFC7407], [RFC8040], [RFC8071], and [I-D.ietf-netconf-tls-client-server].
<CODE BEGINS> file "ietf-restconf-server@2018-06-04.yang"
module ietf-restconf-server {
yang-version 1.1;
namespace "urn:ietf:params:xml:ns:yang:ietf-restconf-server";
prefix "rcs";
import ietf-inet-types {
prefix inet;
reference
"RFC 6991: Common YANG Data Types";
}
import ietf-x509-cert-to-name {
prefix x509c2n;
reference
"RFC 7407: A YANG Data Model for SNMP Configuration";
}
import ietf-tls-server {
prefix ts;
revision-date 2018-06-04; // stable grouping definitions
reference
"RFC ZZZZ: YANG Groupings for TLS Clients and TLS Servers";
}
organization
"IETF NETCONF (Network Configuration) Working Group";
contact
"WG Web: <http://datatracker.ietf.org/wg/netconf/>
WG List: <mailto:netconf@ietf.org>
Author: Kent Watsen
<mailto:kwatsen@juniper.net>
Author: Gary Wu
<mailto:garywu@cisco.com>
Author: Juergen Schoenwaelder
<mailto:j.schoenwaelder@jacobs-university.de>";
description
"This module contains a collection of YANG definitions for
configuring RESTCONF servers.
Copyright (c) 2017 IETF Trust and the persons identified as
authors of the code. All rights reserved.
Redistribution and use in source and binary forms, with or
without modification, is permitted pursuant to, and subject
to the license terms contained in, the Simplified BSD
License set forth in Section 4.c of the IETF Trust's
Legal Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info).
This version of this YANG module is part of RFC XXXX; see
the RFC itself for full legal notices.";
revision "2018-06-04" {
description
"Initial version";
reference
"RFC XXXX: RESTCONF Client and Server Models";
}
// Features
feature listen {
description
"The 'listen' feature indicates that the RESTCONF server
supports opening a port to accept RESTCONF client connections
using at least one transport (e.g., TLS, etc.).";
}
feature tls-listen {
if-feature listen;
description
"The 'tls-listen' feature indicates that the RESTCONF server
supports opening a port to listen for incoming RESTCONF
client connections. This feature exists as TLS might not
be a mandatory to implement transport in the future.";
reference
"RFC 8040: RESTCONF Protocol";
}
feature call-home {
description
"The 'call-home' feature indicates that the RESTCONF
server supports initiating RESTCONF call home connections
to RESTCONF clients using at least one transport (e.g.,
TLS, etc.).";
reference
"RFC 8071: NETCONF Call Home and RESTCONF Call Home";
}
feature tls-call-home {
if-feature call-home;
description
"The 'tls-call-home' feature indicates that the RESTCONF
server supports initiating connections to RESTCONF clients.
This feature exists as TLS might not be a mandatory to
implement transport in the future.";
reference
"RFC 8071: NETCONF Call Home and RESTCONF Call Home";
}
container restconf-server {
uses restconf-server;
description
"Top-level container for RESTCONF server configuration.";
}
grouping restconf-server {
description
"Top-level grouping for RESTCONF server configuration.";
container listen {
if-feature listen;
presence "Enables server to listen for TCP connections";
description "Configures listen behavior";
list endpoint {
key name;
min-elements 1;
description
"List of endpoints to listen for RESTCONF connections.";
leaf name {
type string;
description
"An arbitrary name for the RESTCONF listen endpoint.";
}
choice transport {
mandatory true;
description
"Selects between available transports. This is a
'choice' statement so as to support additional
transport options to be augmented in.";
case tls {
if-feature tls-listen;
container tls {
description
"TLS-specific listening configuration for inbound
connections.";
leaf address {
type inet:ip-address;
description
"The IP address to listen on for incoming
connections. The RESTCONF server will listen
on all configured interfaces if no value is
specified. INADDR_ANY (0.0.0.0) or INADDR6_ANY
(0:0:0:0:0:0:0:0 a.k.a. ::) MUST be used when
the server is to listen on all IPv4 or IPv6
addresses, respectively.";
}
leaf port {
type inet:port-number;
default 443;
description
"The local port number to listen on. If no value
is specified, the IANA-assigned port value for
'https' (443) is used.";
}
uses ts:tls-server-grouping {
refine "client-auth" {
must 'pinned-ca-certs or pinned-client-certs';
description
"RESTCONF servers MUST be able to validate
clients.";
}
augment "client-auth" {
description
"Augments in the cert-to-name structure,
so the RESTCONF server can map TLS-layer
client certificates to RESTCONF usernames.";
container cert-maps {
uses x509c2n:cert-to-name;
description
"The cert-maps container is used by a TLS-
based RESTCONF server to map the RESTCONF
client's presented X.509 certificate to
a RESTCONF username. If no matching and
valid cert-to-name list entry can be found,
then the RESTCONF server MUST close the
connection, and MUST NOT accept RESTCONF
messages over it.";
reference
"RFC 7407: A YANG Data Model for SNMP
Configuration.";
}
}
}
} // end tls container
} // end tls case
} // end transport
} // end endpoint
} // end listen
container call-home {
if-feature call-home;
presence "Enables server to initiate TCP connections";
description "Configures call-home behavior";
list restconf-client {
key name;
min-elements 1;
description
"List of RESTCONF clients the RESTCONF server is to
initiate call-home connections to in parallel.";
leaf name {
type string;
description
"An arbitrary name for the remote RESTCONF client.";
}
container endpoints {
description
"Container for the list of endpoints.";
list endpoint {
key name;
min-elements 1;
ordered-by user;
description
"User-ordered list of endpoints for this RESTCONF
client. Defining more than one enables high-
availability.";
leaf name {
type string;
description
"An arbitrary name for this endpoint.";
}
choice transport {
mandatory true;
description
"Selects between available transports. This is a
'choice' statement so as to support additional
transport options to be augmented in.";
case tls {
if-feature tls-call-home;
container tls {
description
"Specifies TLS-specific call-home transport
configuration.";
leaf address {
type inet:host;
mandatory true;
description
"The IP address or hostname of the endpoint.
If a domain name is configured, then the
DNS resolution should happen on each usage
attempt. If the DNS resolution results in
multiple IP addresses, the IP addresses will
be tried according to local preference order
until a connection has been established or
until all IP addresses have failed.";
}
leaf port {
type inet:port-number;
default 4336;
description
"The IP port for this endpoint. The RESTCONF
server will use the IANA-assigned well-known
port for 'restconf-ch-tls' (4336) if no value
is specified.";
}
uses ts:tls-server-grouping {
refine "client-auth" {
must 'pinned-ca-certs or pinned-client-certs';
description
"RESTCONF servers MUST be able to validate
clients.";
}
augment "client-auth" {
description
"Augments in the cert-to-name structure,
so the RESTCONF server can map TLS-layer
client certificates to RESTCONF usernames.";
container cert-maps {
uses x509c2n:cert-to-name;
description
"The cert-maps container is used by a
TLS-based RESTCONF server to map the
RESTCONF client's presented X.509
certificate to a RESTCONF username. If
no matching and valid cert-to-name list
entry can be found, then the RESTCONF
server MUST close the connection, and
MUST NOT accept RESTCONF messages over
it.";
reference
"RFC 7407: A YANG Data Model for SNMP
Configuration.";
}
}
}
}
}
} // end transport
} // end endpoint
} // end endpoints
container connection-type {
description
"Indicates the RESTCONF client's preference for how the
RESTCONF server's connection is maintained.";
choice connection-type {
default persistent-connection;
description
"Selects between available connection types.";
case persistent-connection {
container persistent {
presence
"Indicates that a persistent connection is to be
maintained.";
description
"Maintain a persistent connection to the RESTCONF
client. If the connection goes down, immediately
start trying to reconnect to it, using the
reconnection strategy.
This connection type minimizes any RESTCONF
client to RESTCONF server data-transfer delay,
albeit at the expense of holding resources
longer.";
leaf idle-timeout {
type uint32;
units "seconds";
default 86400; // one day;
description
"Specifies the maximum number of seconds that
the underlying TLS session may remain idle.
A TLS 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 TLS
client. An unresponsive TLS client will
be dropped after approximately (max-attempts
* max-wait) seconds.";
reference
"RFC 8071: 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 maximum 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
"Indicates that a periodic connection is to be
maintained.";
description
"Periodically connect to the RESTCONF client, so
that the RESTCONF client may send requests pending
for the RESTCONF server. Once the connection has
been closed, for whatever reason, the server will
restart its timer until the next connection.";
leaf idle-timeout {
type uint16;
units "seconds";
default 300; // five minutes
description
"Specifies the maximum number of seconds that
the underlying TLS session may remain idle.
A TLS 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
"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 to the RESTCONF
client before this time if desired
(e.g., to deliver a notification).";
}
}
}
}
}
container reconnect-strategy {
description
"The reconnection strategy directs how a RESTCONF
server reconnects to a RESTCONF client after after
discovering its connection to the client has dropped,
even if due to a reboot. The RESTCONF server starts
with the specified endpoint and tries to connect to
it max-attempts times before trying the next endpoint
in the list (round robin).";
leaf start-with {
type enumeration {
enum first-listed {
description
"Indicates that reconnections should start with
the first endpoint listed.";
}
enum last-connected {
description
"Indicates that reconnections should start with
the endpoint last connected to. If no previous
connection has ever been established, then the
first endpoint configured is used. RESTCONF
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).";
}
}
}
}
}
}
<CODE ENDS>
The YANG module defined in this document uses a grouping defined in [I-D.ietf-netconf-tls-client-server]. Please see the Security Considerations section in that document for concerns related that grouping.
The YANG module defined in this document is designed to be accessed via YANG based management protocols, such as NETCONF [RFC6241] and RESTCONF [RFC8040]. Both of these protocols have mandatory-to-implement secure transport layers (e.g., SSH, TLS) with mutual authentication.
The NETCONF access control model (NACM) [RFC6536] provides the means to restrict access for particular users to a pre-configured subset of all available protocol operations and content.
There are a number of data nodes defined in this YANG module that are writable/creatable/deletable (i.e., config true, which is the default). These data nodes may be considered sensitive or vulnerable in some network environments. Write operations (e.g., edit-config) to these data nodes without proper protection can have a negative effect on network operations. These are the subtrees and data nodes and their sensitivity/vulnerability:
Some of the readable data nodes in this YANG module may be considered sensitive or vulnerable in some network environments. It is thus important to control read access (e.g., via get, get-config, or notification) to these data nodes. These are the subtrees and data nodes and their sensitivity/vulnerability:
Some of the RPC operations in this YANG module may be considered sensitive or vulnerable in some network environments. It is thus important to control access to these operations. These are the operations and their sensitivity/vulnerability:
This document registers two URIs in the IETF XML registry [RFC3688]. Following the format in [RFC3688], the following registrations are requested:
URI: urn:ietf:params:xml:ns:yang:ietf-restconf-client Registrant Contact: The NETCONF WG of the IETF. XML: N/A, the requested URI is an XML namespace. URI: urn:ietf:params:xml:ns:yang:ietf-restconf-server Registrant Contact: The NETCONF WG of the IETF. XML: N/A, the requested URI is an XML namespace.
This document registers two YANG modules in the YANG Module Names registry [RFC7950]. Following the format in [RFC7950], the the following registrations are requested:
name: ietf-restconf-client namespace: urn:ietf:params:xml:ns:yang:ietf-restconf-client prefix: ncc reference: RFC XXXX name: ietf-restconf-server namespace: urn:ietf:params:xml:ns:yang:ietf-restconf-server prefix: ncs reference: RFC XXXX
| [I-D.ietf-netconf-keystore] | Watsen, K., "YANG Data Model for a Centralized Keystore Mechanism", Internet-Draft draft-ietf-netconf-keystore-05, June 2018. |
| [I-D.ietf-netconf-tls-client-server] | Watsen, K. and G. Wu, "YANG Groupings for TLS Clients and TLS Servers", Internet-Draft draft-ietf-netconf-tls-client-server-05, October 2017. |
| [RFC2119] | Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997. |
| [RFC6991] | Schoenwaelder, J., "Common YANG Data Types", RFC 6991, DOI 10.17487/RFC6991, July 2013. |
| [RFC7407] | Bjorklund, M. and J. Schoenwaelder, "A YANG Data Model for SNMP Configuration", RFC 7407, DOI 10.17487/RFC7407, December 2014. |
| [RFC7950] | Bjorklund, M., "The YANG 1.1 Data Modeling Language", RFC 7950, DOI 10.17487/RFC7950, August 2016. |
| [RFC8040] | Bierman, A., Bjorklund, M. and K. Watsen, "RESTCONF Protocol", RFC 8040, DOI 10.17487/RFC8040, January 2017. |
| [RFC8071] | Watsen, K., "NETCONF Call Home and RESTCONF Call Home", RFC 8071, DOI 10.17487/RFC8071, February 2017. |
| [RFC8174] | Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, May 2017. |
| [I-D.ietf-netconf-netconf-client-server] | Watsen, K. and G. Wu, "NETCONF Client and Server Models", Internet-Draft draft-ietf-netconf-netconf-client-server-05, October 2017. |
| [RFC3688] | Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688, DOI 10.17487/RFC3688, January 2004. |
| [RFC5246] | Dierks, T. and E. Rescorla, "The Transport Layer Security (TLS) Protocol Version 1.2", RFC 5246, DOI 10.17487/RFC5246, August 2008. |
| [RFC6241] | Enns, R., Bjorklund, M., Schoenwaelder, J. and A. Bierman, "Network Configuration Protocol (NETCONF)", RFC 6241, DOI 10.17487/RFC6241, June 2011. |
| [RFC6536] | Bierman, A. and M. Bjorklund, "Network Configuration Protocol (NETCONF) Access Control Model", RFC 6536, DOI 10.17487/RFC6536, March 2012. |
| [RFC8340] | Bjorklund, M. and L. Berger, "YANG Tree Diagrams", BCP 215, RFC 8340, DOI 10.17487/RFC8340, March 2018. |
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, Balázs Kovács, David Lamparter, Alan Luchuk, Ladislav Lhotka, Radek Krejci, Tom Petch, Juergen Schoenwaelder, Phil Shafer, Sean Turner, and Bert Wijnen.