NETCONF Working Group K. Watsen
Internet-Draft Watsen Networks
Intended status: Standards Track March 8, 2020
Expires: September 9, 2020
A YANG Data Model for a Truststore
draft-ietf-netconf-trust-anchors-09
Abstract
This document defines a YANG 1.1 data model for configuring global
sets of X.509 certificates, SSH host-keys, and raw public keys that
can be referenced by other data models for trust. While the SSH
host-keys are uniquely for the SSH protocol, certificates, and raw
public keys may have multiple uses, including authenticating protocol
peers and verifying signatures.
Editorial Note (To be removed by RFC Editor)
This draft contains many placeholder values that need to be replaced
with finalized values at the time of publication. This note
summarizes all of the substitutions that are needed. No other RFC
Editor instructions are specified elsewhere in this document.
Artwork in this document contains shorthand references to drafts in
progress. Please apply the following replacements:
o "XXXX" --> the assigned RFC value for this draft
o "YYYY" --> the assigned RFC value for draft-ietf-netconf-crypto-
types
Artwork in this document contains placeholder values for the date of
publication of this draft. Please apply the following replacement:
o "2020-03-08" --> the publication date of this draft
The following Appendix section is to be removed prior to publication:
o Appendix A. Change Log
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
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Copyright Notice
Copyright (c) 2020 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
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publication of this document. Please review these documents
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described in the Simplified BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1. Requirements Language . . . . . . . . . . . . . . . . . . 3
1.2. Tree Diagram Notation . . . . . . . . . . . . . . . . . . 3
2. The Trust Anchors Model . . . . . . . . . . . . . . . . . . . 3
2.1. Tree Diagram . . . . . . . . . . . . . . . . . . . . . . 3
2.2. Example Usage . . . . . . . . . . . . . . . . . . . . . . 6
2.3. YANG Module . . . . . . . . . . . . . . . . . . . . . . . 12
3. Support for Built-in Trust Anchors . . . . . . . . . . . . . 24
4. Security Considerations . . . . . . . . . . . . . . . . . . . 24
5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 25
5.1. The IETF XML Registry . . . . . . . . . . . . . . . . . . 25
5.2. The YANG Module Names Registry . . . . . . . . . . . . . 25
6. References . . . . . . . . . . . . . . . . . . . . . . . . . 26
6.1. Normative References . . . . . . . . . . . . . . . . . . 26
6.2. Informative References . . . . . . . . . . . . . . . . . 26
Appendix A. Change Log . . . . . . . . . . . . . . . . . . . . . 28
A.1. 00 to 01 . . . . . . . . . . . . . . . . . . . . . . . . 28
A.2. 01 to 02 . . . . . . . . . . . . . . . . . . . . . . . . 28
A.3. 02 to 03 . . . . . . . . . . . . . . . . . . . . . . . . 28
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A.4. 03 to 04 . . . . . . . . . . . . . . . . . . . . . . . . 28
A.5. 04 to 05 . . . . . . . . . . . . . . . . . . . . . . . . 28
A.6. 05 to 06 . . . . . . . . . . . . . . . . . . . . . . . . 29
A.7. 06 to 07 . . . . . . . . . . . . . . . . . . . . . . . . 29
A.8. 07 to 08 . . . . . . . . . . . . . . . . . . . . . . . . 29
A.9. 08 to 09 . . . . . . . . . . . . . . . . . . . . . . . . 29
Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . 29
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 30
1. Introduction
This document defines a YANG 1.1 [RFC7950] data model for configuring
global sets of X.509 certificates, SSH host-keys, and raw public keys
that can be referenced by other data models for trust. While the SSH
host-keys are uniquely for the SSH protocol, certificates, and raw
public keys may have multiple uses, including authenticating protocol
peers and verifying signatures.
This document in compliant with Network Management Datastore
Architecture (NMDA) [RFC8342]. For instance, trust anchors installed
during manufacturing (e.g., for trusted well-known services), are
expected to appear in <operational> (see Section 3).
1.1. Requirements Language
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.
1.2. Tree Diagram Notation
Tree diagrams used in this document follow the notation defined in
[RFC8340].
2. The Trust Anchors Model
2.1. Tree Diagram
The following tree diagram provides an overview of the "ietf-
truststore" module.
module: ietf-truststore
+--rw truststore
+--rw certificate-bags! {x509-certificates}?
| +--rw certificate-bag* [name]
| +--rw name string
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| +--rw description? string
| +--rw certificate* [name]
| +--rw name string
| +--rw cert trust-anchor-cert-cms
| +---n certificate-expiration
| +-- expiration-date yang:date-and-time
+--rw ssh-public-key-bags! {ssh-public-keys}?
| +--rw ssh-public-key-bag* [name]
| +--rw name string
| +--rw description? string
| +--rw ssh-public-key* [name]
| +--rw name string
| +--rw algorithm
| | iasa:asymmetric-algorithm-type
| +--rw public-key-format identityref
| +--rw public-key binary
+--rw raw-public-key-bags! {raw-public-keys}?
| +--rw raw-public-key-bag* [name]
| +--rw name string
| +--rw description? string
| +--rw raw-public-key* [name]
| +--rw name string
| +--rw algorithm
| | iasa:asymmetric-algorithm-type
| +--rw public-key-format identityref
| +--rw public-key binary
+--rw public-key-bags! {public-keys}?
+--rw public-key-bag* [name]
+--rw name string
+--rw description? string
+--rw public-key* [name]
+--rw name string
+--rw algorithm
| iasa:asymmetric-algorithm-type
+--rw public-key-format identityref
+--rw public-key binary
grouping local-or-truststore-certs-grouping
+-- (local-or-truststore)
+--:(local) {local-definitions-supported}?
| +-- local-definition
| +-- cert* trust-anchor-cert-cms
| +---n certificate-expiration
| +-- expiration-date yang:date-and-time
+--:(truststore) {truststore-supported,x509-certificates}?
+-- truststore-reference? ts:certificate-bag-ref
grouping local-or-truststore-ssh-public-keys-grouping
+-- (local-or-truststore)
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+--:(local) {local-definitions-supported}?
| +-- local-definition
| +-- ssh-public-key* [name]
| +-- name? string
| +-- algorithm
| | iasa:asymmetric-algorithm-type
| +-- public-key-format identityref
| +-- public-key binary
+--:(truststore) {truststore-supported,ssh-public-keys}?
+-- truststore-reference? ts:ssh-public-key-bag-ref
grouping local-or-truststore-raw-pub-keys-grouping
+-- (local-or-truststore)
+--:(local) {local-definitions-supported}?
| +-- local-definition
| +-- raw-public-key* [name]
| +-- name? string
| +-- algorithm
| | iasa:asymmetric-algorithm-type
| +-- public-key-format identityref
| +-- public-key binary
+--:(truststore) {truststore-supported,raw-public-keys}?
+-- truststore-reference? ts:raw-public-key-bag-ref
grouping local-or-truststore-public-keys-grouping
+-- (local-or-truststore)
+--:(local) {local-definitions-supported}?
| +-- local-definition
| +-- public-key* [name]
| +-- name? string
| +-- algorithm
| | iasa:asymmetric-algorithm-type
| +-- public-key-format identityref
| +-- public-key binary
+--:(truststore) {truststore-supported,public-keys}?
+-- truststore-reference? ts:public-key-bag-ref
grouping truststore-grouping
+-- certificate-bags! {x509-certificates}?
| +-- certificate-bag* [name]
| +-- name? string
| +-- description? string
| +-- certificate* [name]
| +-- name? string
| +-- cert trust-anchor-cert-cms
| +---n certificate-expiration
| +-- expiration-date yang:date-and-time
+-- ssh-public-key-bags! {ssh-public-keys}?
| +-- ssh-public-key-bag* [name]
| +-- name? string
| +-- description? string
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| +-- ssh-public-key* [name]
| +-- name? string
| +-- algorithm iasa:asymmetric-algorithm-type
| +-- public-key-format identityref
| +-- public-key binary
+-- raw-public-key-bags! {raw-public-keys}?
| +-- raw-public-key-bag* [name]
| +-- name? string
| +-- description? string
| +-- raw-public-key* [name]
| +-- name? string
| +-- algorithm iasa:asymmetric-algorithm-type
| +-- public-key-format identityref
| +-- public-key binary
+-- public-key-bags! {public-keys}?
+-- public-key-bag* [name]
+-- name? string
+-- description? string
+-- public-key* [name]
+-- name? string
+-- algorithm iasa:asymmetric-algorithm-type
+-- public-key-format identityref
+-- public-key binary
2.2. Example Usage
The following example illustrates trust anchors in <intended>.
Please see Section 3 for an example illustrating built-in values in
<operational>.
========== NOTE: '\' line wrapping per BCP XXX (RFC XXXX) ===========
<truststore
xmlns="urn:ietf:params:xml:ns:yang:ietf-truststore"
xmlns:or="urn:ietf:params:xml:ns:yang:ietf-origin"
xmlns:ct="urn:ietf:params:xml:ns:yang:ietf-crypto-types">
<!-- A bag of Certificate Bags -->
<certificate-bags or:origin="or:intended">
<!-- Manufacturer's Trusted Root CA Certs (in <operational>)-->
<certificate-bag or:origin="or:system">
<name>manufacturers-root-ca-certs</name>
<description>
Certificates built into the device for authenticating
manufacturer-signed objects, such as TLS server certificates,
vouchers, etc. Note, though listed here, these are not
configurable; any attempt to do so will be denied.
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</description>
<certificate>
<name>Manufacturer Root CA cert 1</name>
<cert>base64encodedvalue==</cert>
</certificate>
<certificate>
<name>Manufacturer Root CA cert 2</name>
<cert>base64encodedvalue==</cert>
</certificate>
</certificate-bag>
<!-- CA Certs for Public (e.g., Internet-based) HTTPS Servers -->
<certificate-bag>
<name>common-ca-certs</name>
<description>
Trust anchors (i.e. CA certs) used to authenticate server
certificates. A server certificate is authenticated if its
end-entity certificate has a chain of trust to one of these
certificates.
</description>
<certificate>
<name>Go Daddy Class 2 Certification Authority</name>
<cert>base64encodedvalue==</cert>
</certificate>
<certificate>
<name>VeriSign Universal Root Certification Authority</name>
<cert>base64encodedvalue==</cert>
</certificate>
</certificate-bag>
<!-- CA Certs for Authenticating Servers Using Private PKIs -->
<certificate-bag>
<name>trusted-server-ca-certs</name>
<description>
Trust anchors (i.e. CA certs) used to authenticate server
certificates. A server certificate is authenticated if its
end-entity certificate has a chain of trust to one of these
certificates.
</description>
<certificate>
<name>Server Cert Issuer #1</name>
<cert>base64encodedvalue==</cert>
</certificate>
<certificate>
<name>Server Cert Issuer #2</name>
<cert>base64encodedvalue==</cert>
</certificate>
</certificate-bag>
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<!-- Pinned End Entity Certs for Authenticating Servers -->
<certificate-bag>
<name>trusted-server-ee-certs</name>
<description>
Specific end-entity certificates used to authenticate server
certificates. A server certificate is authenticated if its
end-entity certificate is an exact match to one of these
certificates.
</description>
<certificate>
<name>My Application #1</name>
<cert>base64encodedvalue==</cert>
</certificate>
<certificate>
<name>My Application #2</name>
<cert>base64encodedvalue==</cert>
</certificate>
</certificate-bag>
<!-- CA Certs for Authenticating Clients -->
<certificate-bag>
<name>trusted-client-ca-certs</name>
<description>
Trust anchors (i.e. CA certs) used to authenticate client
certificates. A client certificate is authenticated if its
end-entity certificate has a chain of trust to one of these
certificates.
</description>
<certificate>
<name>Client Identity Issuer #1</name>
<cert>base64encodedvalue==</cert>
</certificate>
<certificate>
<name>Client Identity Issuer #2</name>
<cert>base64encodedvalue==</cert>
</certificate>
</certificate-bag>
<!-- Pinned End Entity Certs for Authenticating Clients -->
<certificate-bag>
<name>trusted-client-ee-certs</name>
<description>
Specific end-entity certificates used to authenticate client
certificates. A client certificate is authenticated if its
end-entity certificate is an exact match to one of these
certificates.
</description>
<certificate>
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<name>George Jetson</name>
<cert>base64encodedvalue==</cert>
</certificate>
<certificate>
<name>Fred Flintstone</name>
<cert>base64encodedvalue==</cert>
</certificate>
</certificate-bag>
</certificate-bags>
<!-- A List of Public Key Bags -->
<public-key-bags or:origin="or:intended">
<!-- Public Keys for Authenticating SSH Servers -->
<public-key-bag>
<name>trusted-ssh-public-keys</name>
<description>
Specific SSH public keys used to authenticate SSH server
public keys. An SSH server public key is authenticated if
its public key is an exact match to one of these public keys.
This list of SSH public keys is analogous to OpenSSH's
"/etc/ssh/ssh_known_hosts" file.
</description>
<public-key>
<name>corp-fw1</name>
<algorithm>secp256r1</algorithm>
<public-key-format>ct:ssh-public-key-format</public-key-form\
at>
<public-key>base64encodedvalue==</public-key>
</public-key>
<public-key>
<name>corp-fw2</name>
<algorithm>secp256r1</algorithm>
<public-key-format>ct:ssh-public-key-format</public-key-form\
at>
<public-key>base64encodedvalue==</public-key>
</public-key>
</public-key-bag>
<!-- SSH Public Keys for Authenticating User A -->
<public-key-bag>
<name>SSH Public Keys for User A</name>
<description>
SSH public keys used to authenticate a user A's SSH public
keys. An SSH public key is authenticated if it is an exact
match to one of these public keys.
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This list of public keys is analogous to OpenSSH's
"~A/.ssh/authorized_keys" file.
</description>
<public-key>
<name>From Source #1</name>
<algorithm>secp256r1</algorithm>
<public-key-format>ct:ssh-public-key-format</public-key-form\
at>
<public-key>base64encodedvalue==</public-key>
</public-key>
<public-key>
<name>From Source #2</name>
<algorithm>secp256r1</algorithm>
<public-key-format>ct:ssh-public-key-format</public-key-form\
at>
<public-key>base64encodedvalue==</public-key>
</public-key>
</public-key-bag>
<!-- SSH Public Keys for Authenticating User B -->
<public-key-bag>
<name>SSH Public Keys for User B</name>
<description>
SSH public keys used to authenticate a user B's SSH public
keys. An SSH public key is authenticated if it is an exact
match to one of these public keys.
This list of public keys is analogous to OpenSSH's
"~B/.ssh/authorized_keys" file.
</description>
<public-key>
<name>From Source #1</name>
<algorithm>secp256r1</algorithm>
<public-key-format>ct:ssh-public-key-format</public-key-form\
at>
<public-key>base64encodedvalue==</public-key>
</public-key>
<public-key>
<name>From Source #2</name>
<algorithm>secp256r1</algorithm>
<public-key-format>ct:ssh-public-key-format</public-key-form\
at>
<public-key>base64encodedvalue==</public-key>
</public-key>
</public-key-bag>
<!-- Raw Public Keys for FIXME... -->
<public-key-bag>
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<name>Raw Public Keys for Servers</name>
<description>
FIXME...
</description>
<public-key>
<name>Raw Public Key #1</name>
<algorithm>rsa2048</algorithm>
<public-key-format>ct:subject-public-key-info-format</public\
-key-format>
<public-key>base64encodedvalue==</public-key>
</public-key>
<public-key>
<name>Raw Public Key #2</name>
<algorithm>rsa2048</algorithm>
<public-key-format>ct:subject-public-key-info-format</public\
-key-format>
<public-key>base64encodedvalue==</public-key>
</public-key>
</public-key-bag>
<!-- Raw Public Keys for FIXME... -->
<public-key-bag>
<name>Raw Public Keys for Clients</name>
<description>
FIXME...
</description>
<public-key>
<name>Raw Public Key #1</name>
<algorithm>rsa2048</algorithm>
<public-key-format>ct:subject-public-key-info-format</public\
-key-format>
<public-key>base64encodedvalue==</public-key>
</public-key>
<public-key>
<name>Raw Public Key #2</name>
<algorithm>rsa2048</algorithm>
<public-key-format>ct:subject-public-key-info-format</public\
-key-format>
<public-key>base64encodedvalue==</public-key>
</public-key>
</public-key-bag>
</public-key-bags>
</truststore>
The following example illustrates the "certificate-expiration"
notification in use with the NETCONF protocol.
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========== NOTE: '\' line wrapping per BCP XXX (RFC XXXX) ===========
<notification
xmlns="urn:ietf:params:xml:ns:netconf:notification:1.0">
<eventTime>2018-05-25T00:01:00Z</eventTime>
<truststore xmlns="urn:ietf:params:xml:ns:yang:ietf-truststore">
<certificate-bags>
<certificate-bag>
<name>explicitly-trusted-client-certs</name>
<certificate>
<name>George Jetson</name>
<certificate-expiration>
<expiration-date>2018-08-05T14:18:53-05:00</expiration-d\
ate>
</certificate-expiration>
</certificate>
</certificate-bag>
</certificate-bags>
</truststore>
</notification>
2.3. YANG Module
This YANG module imports modules from [RFC8341] and
[I-D.ietf-netconf-crypto-types].
<CODE BEGINS> file "ietf-truststore@2020-03-08.yang"
module ietf-truststore {
yang-version 1.1;
namespace "urn:ietf:params:xml:ns:yang:ietf-truststore";
prefix ts;
import ietf-netconf-acm {
prefix nacm;
reference
"RFC 8341: Network Configuration Access Control Model";
}
import ietf-crypto-types {
prefix ct;
reference
"RFC YYYY: Common YANG Data Types for Cryptography";
}
organization
"IETF NETCONF (Network Configuration) Working Group";
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contact
"WG Web : <http://datatracker.ietf.org/wg/netconf/>
WG List : <mailto:netconf@ietf.org>
Author : Kent Watsen <kent+ietf@watsen.net>
Author : Henk Birkholz <henk.birkholz@sit.fraunhofer.de>";
description
"This module defines a truststore to centralize management
of trust anchors including X.509 certificates, SSH public
keys, raw public keys.
Copyright (c) 2019 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
(https://trustee.ietf.org/license-info).
This version of this YANG module is part of RFC XXXX
(https://www.rfc-editor.org/info/rfcXXXX); see the RFC
itself for full legal notices.
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 (RFC 2119)
(RFC 8174) when, and only when, they appear in all
capitals, as shown here.";
revision 2020-03-08 {
description
"Initial version";
reference
"RFC XXXX: A YANG Data Model for a Truststore";
}
/****************/
/* Features */
/****************/
feature truststore-supported {
description
"The 'truststore-supported' feature indicates that the
server supports the truststore (i.e., implements the
'ietf-truststore' module).";
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}
feature local-definitions-supported {
description
"The 'local-definitions-supported' feature indicates that
the server supports locally-defined trust anchors.";
}
feature x509-certificates {
description
"The 'x509-certificates' feature indicates that the server
implements the /truststore/certificate-bags subtree.";
}
feature ssh-public-keys {
description
"The 'ssh-public-keys' feature indicates that the server
implements the /truststore/ssh-public-key-bags subtree.";
}
feature raw-public-keys {
description
"The 'raw-public-keys' feature indicates that the server
implements the /truststore/raw-public-key-bags subtree.";
}
feature public-keys {
description
"The 'public-keys' feature indicates that the server
implements the /truststore/public-key-bags subtree.";
}
/****************/
/* Typedefs */
/****************/
typedef certificate-bag-ref {
type leafref {
path "/ts:truststore/ts:certificate-bags/"
+ "ts:certificate-bag/ts:name";
}
description
"This typedef defines a reference to a certificate bag
defined in the truststore.";
}
typedef certificate-ref {
type leafref {
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path "/ts:truststore/certificate-bags/certificate-bag" +
"[name = current()/../certificate-bag]/certificate/name";
}
description
"This typedef define a reference to a specific certificate
in a certificate bag defined in the truststore. This
typedef requires that there exist a sibling 'leaf' node
called 'certificate-bag' that SHOULD have the typedef
'certificate-bag-ref'.";
}
typedef ssh-public-key-bag-ref {
type leafref {
path "/ts:truststore/ts:ssh-public-key-bags"
+ "/ts:ssh-public-key-bag/ts:name";
}
description
"This typedef defines a reference to an SSH public key bag
defined in the truststore.";
}
typedef ssh-public-key-ref {
type leafref {
path "/ts:truststore/ssh-public-key-bags/ssh-public-key-bag" +
"[name = current()/../ssh-public-key-bag]" +
"/ssh-public-key/name";
}
description
"This typedef define a reference to a specific SSH public key
in a SSH public key bag defined in the truststore. This
typedef requires that there exist a sibling 'leaf' node
called 'ssh-public-key-bag' that SHOULD have the typedef
'ssh-public-key-bag-ref'.";
}
typedef raw-public-key-bag-ref {
type leafref {
path "/ts:truststore/ts:raw-public-key-bags/"
+ "ts:raw-public-key-bag/ts:name";
}
description
"This typedef define a reference to a raw public key bag
defined in the truststore.";
}
typedef raw-public-key-ref {
type leafref {
path "/ts:truststore/raw-public-key-bags/raw-public-key-bag" +
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"[name = current()/../raw-public-key-bag]/" +
"raw-public-key/name";
}
description
"This typedef define a reference to a specific raw public key
in a raw public key bag defined in the truststore. This
typedef requires that there exist a sibling 'leaf' node
called 'raw-public-key-bag' that SHOULD have the typedef
'raw-public-key-bag-ref'.";
}
typedef public-key-bag-ref {
type leafref {
path "/ts:truststore/ts:public-key-bags/"
+ "ts:public-key-bag/ts:name";
}
description
"This typedef define a reference to a public key bag
defined in the truststore.";
}
typedef public-key-ref {
type leafref {
path "/ts:truststore/public-key-bags/public-key-bag" +
"[name = current()/../public-key-bag]/" +
"public-key/name";
}
description
"This typedef define a reference to a specific public key
in a public key bag defined in the truststore. This
typedef requires that there exist a sibling 'leaf' node
called 'public-key-bag' that SHOULD have the typedef
'public-key-bag-ref'.";
}
/*****************/
/* Groupings */
/*****************/
grouping local-or-truststore-certs-grouping {
description
"A grouping that allows the certificates to be either
configured locally, within the using data model, or be a
reference to a certificate bag stored in the truststore.";
choice local-or-truststore {
mandatory true;
case local {
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if-feature "local-definitions-supported";
container local-definition {
description
"A container for locally configured trust anchor
certificates.";
uses ct:trust-anchor-certs-grouping;
}
}
case truststore {
if-feature "truststore-supported";
if-feature "x509-certificates";
leaf truststore-reference {
type ts:certificate-bag-ref;
description
"A reference to a certificate bag that exists in the
truststore.";
}
}
description
"A choice between an inlined definition and a definition
that exists in the truststore.";
}
}
grouping local-or-truststore-ssh-public-keys-grouping {
description
"A grouping that allows the ssh public keys to be either
configured locally, within the using data model, or be a
reference to a ssh public key bag stored in the truststore.";
choice local-or-truststore {
mandatory true;
case local {
if-feature "local-definitions-supported";
container local-definition {
description
"Container to hold local ssh public key definitions.";
list ssh-public-key {
key name;
min-elements 1;
description
"A ssh public key.";
leaf name {
type string;
description
"An arbitrary name for this ssh public key.";
}
uses ct:public-key-grouping {
refine "public-key-format" {
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must '. = "ct:ssh-public-key-format"';
}
}
}
}
}
case truststore {
if-feature "truststore-supported";
if-feature "ssh-public-keys";
leaf truststore-reference {
type ts:ssh-public-key-bag-ref;
description
"A reference to a bag of SSH public keys that exist in
the truststore.";
}
}
description
"A choice between an inlined definition and a definition
that exists in the truststore.";
}
}
grouping local-or-truststore-raw-pub-keys-grouping {
description
"A grouping that allows the raw public keys to be either
configured locally, within the using data model, or be a
reference to a raw public key bag stored in the truststore.";
choice local-or-truststore {
mandatory true;
case local {
if-feature "local-definitions-supported";
container local-definition {
description
"Container to hold local raw public key definitions.";
list raw-public-key {
key name;
description
"A raw public key definition.";
leaf name {
type string;
description
"An arbitrary name for this raw public key.";
}
uses ct:public-key-grouping;
}
}
}
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case truststore {
if-feature "truststore-supported";
if-feature "raw-public-keys";
leaf truststore-reference {
type ts:raw-public-key-bag-ref;
description
"A reference to a bag of raw public keys that exist
in the truststore.";
}
}
description
"A choice between an inlined definition and a definition
that exists in the truststore.";
}
}
grouping local-or-truststore-public-keys-grouping {
description
"A grouping that allows the public keys to be either
configured locally, within the using data model, or be a
reference to a public key bag stored in the truststore.";
choice local-or-truststore {
mandatory true;
case local {
if-feature "local-definitions-supported";
container local-definition {
description
"Container to hold local public key definitions.";
list public-key {
key name;
description
"A public key definition.";
leaf name {
type string;
description
"An arbitrary name for this public key.";
}
uses ct:public-key-grouping;
}
}
}
case truststore {
if-feature "truststore-supported";
if-feature "public-keys";
leaf truststore-reference {
type ts:public-key-bag-ref;
description
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"A reference to a bag of public keys that exist
in the truststore.";
}
}
description
"A choice between an inlined definition and a definition
that exists in the truststore.";
}
}
grouping truststore-grouping {
description
"Grouping definition enables use in other contexts. Where
used, implementations SHOULD augment new 'case' statements
into the local-or-truststore 'choice' statements to supply
leafrefs to the model-specific location.";
container certificate-bags {
if-feature "x509-certificates";
presence
"Indicates that certificate bags have been configured.";
description
"A collection of certificate bags.";
list certificate-bag {
key "name";
min-elements 1;
description
"A bag of certificates. Each bag of certificates SHOULD
be for a specific purpose. For instance, one bag could
be used to authenticate a specific set of servers, while
another could be used to authenticate a specific set of
clients.";
leaf name {
type string;
description
"An arbitrary name for this bag of certificates.";
}
leaf description {
type string;
description
"A description for this bag of certificates. The
intended purpose for the bag SHOULD be described.";
}
list certificate {
key "name";
min-elements 1;
description
"A trust anchor certificate.";
leaf name {
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type string;
description
"An arbitrary name for this certificate.";
}
uses ct:trust-anchor-cert-grouping {
refine "cert" {
mandatory true;
}
}
}
}
}
container ssh-public-key-bags {
if-feature "ssh-public-keys";
presence
"Indicates that SSH public keys have been configured.";
description
"A collection of SSH public key bags.";
list ssh-public-key-bag {
key "name";
min-elements 1;
description
"A bag of SSH public keys. Each bag of SSH public keys
SHOULD be for a specific purpose. For instance, one
bag could be used authenticate a specific set of servers
(i.e., host keys), while another bag could be used to
authenticate a specific client or set of clients.";
leaf name {
type string;
description
"An arbitrary name for this bag of SSH public keys.";
}
leaf description {
type string;
description
"A description for this bag of SSH public keys. The
intended purpose for the bag SHOULD be described.";
}
list ssh-public-key {
key "name";
min-elements 1;
description
"An SSH public key.";
leaf name {
type string;
description
"An arbitrary name for this SSH public key.";
}
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uses ct:public-key-grouping {
refine "public-key-format" {
must '. = "ct:ssh-public-key-format"';
}
}
}
}
}
container raw-public-key-bags {
if-feature "raw-public-keys";
presence
"Indicates that raw public keys have been configured.";
description
"A collection of raw public key bags.";
list raw-public-key-bag {
key "name";
min-elements 1;
description
"A bag of raw public keys. Each bag of keys SHOULD be for
a specific purpose. For instance, one bag could be used
authenticate a specific set of servers, while another
could be used to authenticate a specific set of clients.";
leaf name {
type string;
description
"An arbitrary name for this bag of raw public keys.";
}
leaf description {
type string;
description
"A description for this bag raw public keys. The
intended purpose for the bag SHOULD be described.";
}
list raw-public-key {
key "name";
min-elements 1;
description
"A raw public key.";
leaf name {
type string;
description
"An arbitrary name for this raw public key.";
}
uses ct:public-key-grouping {
refine "public-key-format" {
must '. = "ct:subject-public-key-info-format"';
}
}
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//uses ct:public-key-grouping;
}
}
}
container public-key-bags {
if-feature "public-keys";
presence
"Indicates that public keys have been configured.";
description
"A collection of public key bags.";
list public-key-bag {
key "name";
min-elements 1;
description
"A bag of public keys. Each bag of keys SHOULD be for
a specific purpose. For instance, one bag could be used
authenticate a specific set of servers, while another
could be used to authenticate a specific set of clients.";
leaf name {
type string;
description
"An arbitrary name for this bag of public keys.";
}
leaf description {
type string;
description
"A description for this bag public keys. The
intended purpose for the bag SHOULD be described.";
}
list public-key {
key "name";
min-elements 1;
description
"A public key.";
leaf name {
type string;
description
"An arbitrary name for this public key.";
}
uses ct:public-key-grouping;
}
}
}
}
/*********************************/
/* Protocol accessible nodes */
/*********************************/
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container truststore {
nacm:default-deny-write;
description
"The truststore contains sets of X.509 certificates, SSH
public keys, and raw public keys.";
uses truststore-grouping;
}
}
<CODE ENDS>
3. Support for Built-in Trust Anchors
In some implementations, the operating system a device is running,
may define some built-in trust anchors. For instance, there may be
built-in trust anchors enabling the device to securely connect to
well-known services (e.g., an SZTP [RFC8572] bootstap server) or
trust anchors to connect to arbitrary services using public PKI.
Built-in trust anchors are expected to be set by a vendor-specific
process. Any ability for operators to modify built-in trust anchors
is outside the scope of this docuemnt.
As built-in trust anchors are provided by the system (not
configuration), they are present in <operational>. The following
example illustrates bui;t-in trust anchors in <operational>.
(FIXME: add illustration with origin="system" here)
In order for the built-in trust anchors to be referenced by
configuration, they must first be copied into <intended> as the
example in Section 2.2 illustrates for the built-in trust anchors
above. Note that this strategy is chosen, rather then setting
"require-instance false" for the various leafrefs, as built-in trust
anchors are relatively few in number and hence not worth relaxing the
validation for.
4. Security Considerations
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) [RFC8341] provides the means
to restrict access for particular users to a pre-configured subset of
all available protocol operations and content.
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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:
/: The entire data tree defined by this module is sensitive to
write operations. For instance, the addition or removal of any
trust anchor may dramatically alter the implemented security
policy. For this reason, the NACM extension "default-deny-
write" has been set for the entire data tree.
None of the readable data nodes in this YANG module are considered
sensitive or vulnerable in network environments.
This module does not define any RPCs, actions, or notifications, and
thus the security consideration for such is not provided here.
5. IANA Considerations
5.1. The IETF XML Registry
This document registers one URI in the "ns" subregistry of the IETF
XML Registry [RFC3688]. Following the format in [RFC3688], the
following registration is requested:
URI: urn:ietf:params:xml:ns:yang:ietf-truststore
Registrant Contact: The NETCONF WG of the IETF.
XML: N/A, the requested URI is an XML namespace.
5.2. The YANG Module Names Registry
This document registers one YANG module in the YANG Module Names
registry [RFC6020]. Following the format in [RFC6020], the the
following registration is requested:
name: ietf-truststore
namespace: urn:ietf:params:xml:ns:yang:ietf-truststore
prefix: ta
reference: RFC XXXX
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6. References
6.1. Normative References
[I-D.ietf-netconf-crypto-types]
Watsen, K. and H. Wang, "Common YANG Data Types for
Cryptography", draft-ietf-netconf-crypto-types-13 (work in
progress), November 2019.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/info/rfc2119>.
[RFC7950] Bjorklund, M., Ed., "The YANG 1.1 Data Modeling Language",
RFC 7950, DOI 10.17487/RFC7950, August 2016,
<https://www.rfc-editor.org/info/rfc7950>.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
May 2017, <https://www.rfc-editor.org/info/rfc8174>.
[RFC8341] Bierman, A. and M. Bjorklund, "Network Configuration
Access Control Model", STD 91, RFC 8341,
DOI 10.17487/RFC8341, March 2018,
<https://www.rfc-editor.org/info/rfc8341>.
6.2. Informative References
[RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688,
DOI 10.17487/RFC3688, January 2004,
<https://www.rfc-editor.org/info/rfc3688>.
[RFC6020] Bjorklund, M., Ed., "YANG - A Data Modeling Language for
the Network Configuration Protocol (NETCONF)", RFC 6020,
DOI 10.17487/RFC6020, October 2010,
<https://www.rfc-editor.org/info/rfc6020>.
[RFC6241] Enns, R., Ed., Bjorklund, M., Ed., Schoenwaelder, J., Ed.,
and A. Bierman, Ed., "Network Configuration Protocol
(NETCONF)", RFC 6241, DOI 10.17487/RFC6241, June 2011,
<https://www.rfc-editor.org/info/rfc6241>.
[RFC8040] Bierman, A., Bjorklund, M., and K. Watsen, "RESTCONF
Protocol", RFC 8040, DOI 10.17487/RFC8040, January 2017,
<https://www.rfc-editor.org/info/rfc8040>.
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[RFC8340] Bjorklund, M. and L. Berger, Ed., "YANG Tree Diagrams",
BCP 215, RFC 8340, DOI 10.17487/RFC8340, March 2018,
<https://www.rfc-editor.org/info/rfc8340>.
[RFC8342] Bjorklund, M., Schoenwaelder, J., Shafer, P., Watsen, K.,
and R. Wilton, "Network Management Datastore Architecture
(NMDA)", RFC 8342, DOI 10.17487/RFC8342, March 2018,
<https://www.rfc-editor.org/info/rfc8342>.
[RFC8572] Watsen, K., Farrer, I., and M. Abrahamsson, "Secure Zero
Touch Provisioning (SZTP)", RFC 8572,
DOI 10.17487/RFC8572, April 2019,
<https://www.rfc-editor.org/info/rfc8572>.
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Appendix A. Change Log
A.1. 00 to 01
o Added features "x509-certificates" and "ssh-host-keys".
o Added nacm:default-deny-write to "trust-anchors" container.
A.2. 01 to 02
o Switched "list pinned-certificate" to use the "trust-anchor-cert-
grouping" from crypto-types. Effectively the same definition as
before.
A.3. 02 to 03
o Updated copyright date, boilerplate template, affiliation, folding
algorithm, and reformatted the YANG module.
A.4. 03 to 04
o Added groupings 'local-or-truststore-certs-grouping' and 'local-
or-truststore-host-keys-grouping', matching similar definitions in
the keystore draft. Note new (and incomplete) "truststore" usage!
o Related to above, also added features 'truststore-supported' and
'local-trust-anchors-supported'.
A.5. 04 to 05
o Renamed "trust-anchors" to "truststore"
o Removed "pinned." prefix everywhere, to match truststore rename
o Moved everything under a top-level 'grouping' to enable use in
other contexts.
o Renamed feature from 'local-trust-anchors-supported' to 'local-
definitions-supported' (same name used in keystore)
o Removed the "require-instance false" statement from the "*-ref"
typedefs.
o Added missing "ssh-host-keys" and "x509-certificates" if-feature
statements
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A.6. 05 to 06
o Editorial changes only.
A.7. 06 to 07
o Added Henk Birkholz as a co-author (thanks Henk!)
o Added PSKs and raw public keys to Truststore.
A.8. 07 to 08
o Added new "Support for Built-in Trust Anchors" section.
o Removed spurious "uses ct:trust-anchor-certs-grouping" line.
o Removed PSK from model.
A.9. 08 to 09
o Removed remaining PSK references from text.
o Wrapped each top-level list with a container.
o Introduced "bag" term.
o Merged "SSH Public Keys" and "Raw Public Keys" in a single "Public
Keys" bag. Consuming downstream modules (i.e., "ietf-[ssh/tls]-
[client/server]) refinei the "public-key-format" to be either SSH
or TLS specific as needed.
Acknowledgements
The authors especially thank Henk Birkholz for contributing YANG to
the ietf-truststore module supporting raw public keys and PSKs (pre-
shared or pairwise-symmetric keys). While these contributions were
eventually replaced by reusing the existing support for asymmetric
and symmetric trust anchors, respectively, it was only thru Henk's
initiative that the WG was able to come to that result.
The authors additionally thank the following for helping give shape
to this work (ordered by last name): Martin Bjorklund, Nick Hancock,
Balazs Kovacs, Eric Voit, and Liang Xia.
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Author's Address
Kent Watsen
Watsen Networks
EMail: kent+ietf@watsen.net
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