A YANG Data Model for a Truststore
draft-ietf-netconf-trust-anchors-22
The information below is for an old version of the document.
| Document | Type |
This is an older version of an Internet-Draft whose latest revision state is "Active".
|
|
|---|---|---|---|
| Author | Kent Watsen | ||
| Last updated | 2024-01-25 (Latest revision 2023-12-28) | ||
| Replaces | draft-kwatsen-netconf-trust-anchors | ||
| RFC stream | Internet Engineering Task Force (IETF) | ||
| Formats | |||
| Reviews |
GENART Last Call review
by Paul Kyzivat
Ready w/nits
SECDIR Last Call review
(of
-13)
by Yoav Nir
Has issues
YANGDOCTORS Last Call review
(of
-13)
by Jürgen Schönwälder
Ready w/issues
OPSDIR Last Call Review due 2024-01-24
Incomplete
|
||
| Additional resources | Mailing list discussion | ||
| Stream | WG state | Submitted to IESG for Publication | |
| Document shepherd | Qin Wu | ||
| Shepherd write-up | Show Last changed 2022-10-19 | ||
| IESG | IESG state | IESG Evaluation | |
| Consensus boilerplate | Yes | ||
| Telechat date | (None) | ||
| Responsible AD | Robert Wilton | ||
| Send notices to | bill.wu@huawei.com, mjethanandani@gmail.com | ||
| IANA | IANA review state | IANA OK - Actions Needed | |
| IANA expert review state | Expert Reviews OK |
draft-ietf-netconf-trust-anchors-22
NETCONF Working Group K. Watsen
Internet-Draft Watsen Networks
Intended status: Standards Track 28 December 2023
Expires: 30 June 2024
A YANG Data Model for a Truststore
draft-ietf-netconf-trust-anchors-22
Abstract
This document defines a YANG module for configuring bags of
certificates and bags of public keys that can be referenced by other
data models for trust. Notifications are sent when certificates are
about to expire.
Editorial Note (To be removed by RFC Editor)
This draft contains 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:
* AAAA --> the assigned RFC value for draft-ietf-netconf-crypto-
types
* BBBB --> the assigned RFC value for this draft
Artwork in this document contains placeholder values for the date of
publication of this draft. Please apply the following replacement:
* 2023-12-28 --> the publication date of this draft
The "Relation to other RFCs" section Section 1.1 contains the text
"one or more YANG modules" and, later, "modules". This text is
sourced from a file in a context where it is unknown how many modules
a draft defines. The text is not wrong as is, but it may be improved
by stating more directly how many modules are defined.
The "Relation to other RFCs" section Section 1.1 contains a self-
reference to this draft, along with a corresponding reference in the
Appendix. Please replace the self-reference in this section with
"This RFC" (or similar) and remove the self-reference in the
"Normative/Informative References" section, whichever it is in.
Watsen Expires 30 June 2024 [Page 1]
Internet-Draft A YANG Data Model for a Truststore December 2023
Tree-diagrams in this draft may use the '/' line-folding mode defined
in RFC 8792. However, nicer-to-the-eye is when the '//' line-folding
mode is used. The AD suggested suggested putting a request here for
the RFC Editor to help convert "ugly" '/' folded examples to use the
'//' folding mode. "Help convert" may be interpreted as, identify
what looks ugly and ask the authors to make the adjustment.
The following Appendix section is to be removed prior to publication:
* 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.
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/.
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
This Internet-Draft will expire on 30 June 2024.
Copyright Notice
Copyright (c) 2023 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 Revised BSD License text as
described in Section 4.e of the Trust Legal Provisions and are
provided without warranty as described in the Revised BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 4
Watsen Expires 30 June 2024 [Page 2]
Internet-Draft A YANG Data Model for a Truststore December 2023
1.1. Relation to other RFCs . . . . . . . . . . . . . . . . . 4
1.2. Specification Language . . . . . . . . . . . . . . . . . 6
1.3. Adherence to the NMDA . . . . . . . . . . . . . . . . . . 6
1.4. Conventions . . . . . . . . . . . . . . . . . . . . . . . 6
2. The "ietf-truststore" Module . . . . . . . . . . . . . . . . 6
2.1. Data Model Overview . . . . . . . . . . . . . . . . . . . 6
2.2. Example Usage . . . . . . . . . . . . . . . . . . . . . . 12
2.3. YANG Module . . . . . . . . . . . . . . . . . . . . . . . 21
3. Support for Built-in Trust Anchors . . . . . . . . . . . . . 30
4. Security Considerations . . . . . . . . . . . . . . . . . . . 32
4.1. Security of Data at Rest . . . . . . . . . . . . . . . . 32
4.2. Unconstrained Public Key Usage . . . . . . . . . . . . . 33
4.3. The "ietf-truststore" YANG Module . . . . . . . . . . . . 33
5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 34
5.1. The "IETF XML" Registry . . . . . . . . . . . . . . . . . 34
5.2. The "YANG Module Names" Registry . . . . . . . . . . . . 34
6. References . . . . . . . . . . . . . . . . . . . . . . . . . 34
6.1. Normative References . . . . . . . . . . . . . . . . . . 34
6.2. Informative References . . . . . . . . . . . . . . . . . 35
Appendix A. Change Log . . . . . . . . . . . . . . . . . . . . . 37
A.1. 00 to 01 . . . . . . . . . . . . . . . . . . . . . . . . 37
A.2. 01 to 02 . . . . . . . . . . . . . . . . . . . . . . . . 37
A.3. 02 to 03 . . . . . . . . . . . . . . . . . . . . . . . . 37
A.4. 03 to 04 . . . . . . . . . . . . . . . . . . . . . . . . 37
A.5. 04 to 05 . . . . . . . . . . . . . . . . . . . . . . . . 37
A.6. 05 to 06 . . . . . . . . . . . . . . . . . . . . . . . . 38
A.7. 06 to 07 . . . . . . . . . . . . . . . . . . . . . . . . 38
A.8. 07 to 08 . . . . . . . . . . . . . . . . . . . . . . . . 38
A.9. 08 to 09 . . . . . . . . . . . . . . . . . . . . . . . . 38
A.10. 09 to 10 . . . . . . . . . . . . . . . . . . . . . . . . 38
A.11. 10 to 11 . . . . . . . . . . . . . . . . . . . . . . . . 39
A.12. 11 to 12 . . . . . . . . . . . . . . . . . . . . . . . . 39
A.13. 12 to 13 . . . . . . . . . . . . . . . . . . . . . . . . 39
A.14. 13 to 14 . . . . . . . . . . . . . . . . . . . . . . . . 39
A.15. 14 to 15 . . . . . . . . . . . . . . . . . . . . . . . . 39
A.16. 15 to 16 . . . . . . . . . . . . . . . . . . . . . . . . 40
A.17. 16 to 17 . . . . . . . . . . . . . . . . . . . . . . . . 40
A.18. 17 to 18 . . . . . . . . . . . . . . . . . . . . . . . . 40
A.19. 18 to 19 . . . . . . . . . . . . . . . . . . . . . . . . 40
A.20. 19 to 20 . . . . . . . . . . . . . . . . . . . . . . . . 40
A.21. 20 to 21 . . . . . . . . . . . . . . . . . . . . . . . . 40
A.22. 21 to 22 . . . . . . . . . . . . . . . . . . . . . . . . 41
Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . 41
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 41
Watsen Expires 30 June 2024 [Page 3]
Internet-Draft A YANG Data Model for a Truststore December 2023
1. Introduction
This document defines a YANG 1.1 [RFC7950] module having the
following characteristics:
Provide a central truststore for storing raw public keys and/or
certificates.
Provide support for storing named bags of raw public keys and/or
named bags of certificates.
Provide types that can be used to reference raw public keys or
certificates stored in the central truststore.
Provide groupings that enable raw public keys and certificates to
be configured inline or as references truststore instances.
Enable the truststore to be instantiated in other data models, in
addition to or in lieu of the central truststore instance.
1.1. Relation to other RFCs
This document presents one or more YANG modules [RFC7950] that are
part of a collection of RFCs that work together to, ultimately,
enable the configuration of both the clients and servers of both the
NETCONF [RFC6241] and RESTCONF [RFC8040] protocols.
The dependency relationship between the primary YANG groupings
defined in the various RFCs is presented in the below diagram. In
some cases, a draft may define secondary groupings that introduce
dependencies not illustrated in the diagram. The labels in the
diagram are a shorthand name for the defining RFC. The citation
reference for shorthand name is provided below the diagram.
Watsen Expires 30 June 2024 [Page 4]
Internet-Draft A YANG Data Model for a Truststore December 2023
crypto-types
^ ^
/ \
/ \
truststore keystore
^ ^ ^ ^
| +---------+ | |
| | | |
| +------------+ |
tcp-client-server | / | |
^ ^ ssh-client-server | |
| | ^ tls-client-server
| | | ^ ^ http-client-server
| | | | | ^
| | | +-----+ +---------+ |
| | | | | |
| +-----------|--------|--------------+ | |
| | | | | |
+-----------+ | | | | |
| | | | | |
| | | | | |
netconf-client-server restconf-client-server
+======================+===========================================+
|Label in Diagram | Originating RFC |
+======================+===========================================+
|crypto-types | [I-D.ietf-netconf-crypto-types] |
+----------------------+-------------------------------------------+
|truststore | [I-D.ietf-netconf-trust-anchors] |
+----------------------+-------------------------------------------+
|keystore | [I-D.ietf-netconf-keystore] |
+----------------------+-------------------------------------------+
|tcp-client-server | [I-D.ietf-netconf-tcp-client-server] |
+----------------------+-------------------------------------------+
|ssh-client-server | [I-D.ietf-netconf-ssh-client-server] |
+----------------------+-------------------------------------------+
|tls-client-server | [I-D.ietf-netconf-tls-client-server] |
+----------------------+-------------------------------------------+
|http-client-server | [I-D.ietf-netconf-http-client-server] |
+----------------------+-------------------------------------------+
|netconf-client-server | [I-D.ietf-netconf-netconf-client-server] |
+----------------------+-------------------------------------------+
|restconf-client-server| [I-D.ietf-netconf-restconf-client-server] |
+----------------------+-------------------------------------------+
Table 1: Label to RFC Mapping
Watsen Expires 30 June 2024 [Page 5]
Internet-Draft A YANG Data Model for a Truststore December 2023
1.2. Specification 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.
1.3. Adherence to the NMDA
This document is compliant with the 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).
1.4. Conventions
Various examples used in this document use a placeholder value for
binary data that has been base64 encoded (e.g., "BASE64VALUE=").
This placeholder value is used as real base64 encoded structures are
often many lines long and hence distracting to the example being
presented.
2. The "ietf-truststore" Module
This section defines a YANG 1.1 [RFC7950] module called "ietf-
truststore". A high-level overview of the module is provided in
Section 2.1. Examples illustrating the module's use are provided in
Examples (Section 2.2). The YANG module itself is defined in
Section 2.3.
2.1. Data Model Overview
This section provides an overview of the "ietf-truststore" module in
terms of its features, typedefs, groupings, and protocol-accessible
nodes.
2.1.1. Features
The following diagram lists all the "feature" statements defined in
the "ietf-truststore" module:
Features:
+-- central-truststore-supported
+-- inline-definitions-supported
+-- certificates
+-- public-keys
Watsen Expires 30 June 2024 [Page 6]
Internet-Draft A YANG Data Model for a Truststore December 2023
The diagram above uses syntax that is similar to but not defined in
[RFC8340].
2.1.2. Typedefs
The following diagram lists the "typedef" statements defined in the
"ietf-truststore" module:
Typedefs:
leafref
+-- certificate-bag-ref
+-- certificate-ref
+-- public-key-bag-ref
+-- public-key-ref
The diagram above uses syntax that is similar to but not defined in
[RFC8340].
Comments:
* All the typedefs defined in the "ietf-truststore" module extend
the base "leafref" type defined in [RFC7950].
* The leafrefs refer to certificates, public keys, and bags in the
central truststore, when this module is implemented.
* These typedefs are provided as an aid to consuming modules that
import the "ietf-truststore" module.
2.1.3. Groupings
The "ietf-truststore" module defines the following "grouping"
statements:
* certificate-ref-grouping
* public-key-ref-grouping
* inline-or-truststore-certs-grouping
* inline-or-truststore-public-keys-grouping
* truststore-grouping
Each of these groupings are presented in the following subsections.
2.1.3.1. The "certificate-ref-grouping" Grouping
The following tree diagram [RFC8340] illustrates the "certificate-
ref-grouping" grouping:
Watsen Expires 30 June 2024 [Page 7]
Internet-Draft A YANG Data Model for a Truststore December 2023
grouping certificate-ref-grouping:
+-- certificate-bag? ts:certificate-bag-ref
| {central-truststore-supported,certificates}?
+-- certificate? ts:certificate-ref
Comments:
* The "certificate-ref-grouping" grouping is provided soley as
convenience to consuming modules that wish to enable the
configuration of a reference to a certificate in a certificate-bag
in the truststore.
* The "certificate-bag" leaf uses the "certificate-bag-ref" typedef
defined in Section 2.1.2.
* The "certificate" leaf uses the "certificate-ref" typedef defined
in Section 2.1.2.
2.1.3.2. The "public-key-ref-grouping" Grouping
The following tree diagram [RFC8340] illustrates the "public-key-ref-
grouping" grouping:
grouping public-key-ref-grouping:
+-- public-key-bag? ts:public-key-bag-ref
| {central-truststore-supported,public-keys}?
+-- public-key? ts:public-key-ref
Comments:
* The "public-key-ref-grouping" grouping is provided soley as
convenience to consuming modules that wish to enable the
configuration of a reference to a public-key in a public-key-bag
in the truststore.
* The "public-key-bag" leaf uses the "public-key-bag-ref" typedef
defined in Section 2.1.2.
* The "public-key" leaf uses the "public-key-ref" typedef defined in
Section 2.1.2.
2.1.3.3. The "inline-or-truststore-certs-grouping" Grouping
The following tree diagram [RFC8340] illustrates the "inline-or-
truststore-certs-grouping" grouping:
Watsen Expires 30 June 2024 [Page 8]
Internet-Draft A YANG Data Model for a Truststore December 2023
grouping inline-or-truststore-certs-grouping:
+-- (inline-or-truststore)
+--:(inline) {inline-definitions-supported}?
| +-- inline-definition
| +-- certificate* [name]
| +-- name? string
| +---u ct:trust-anchor-cert-grouping
+--:(central-truststore)
{central-truststore-supported,certificates}?
+-- central-truststore-reference? ts:certificate-bag-ref
Comments:
* The "inline-or-truststore-certs-grouping" grouping is provided
soley as convenience to consuming modules that wish to offer an
option whether a bag of certificates can be defined inline or as a
reference to a bag in the truststore.
* A "choice" statement is used to expose the various options. Each
option is enabled by a "feature" statement. Additional "case"
statements MAY be augmented in if, e.g., there is a need to
reference a bag in an alternate location.
* For the "inline-definition" option, the "certificate" node uses
the "trust-anchor-cert-grouping" grouping discussed in
Section 2.1.4.7 of [I-D.ietf-netconf-crypto-types].
* For the "central-truststore" option, the "central-truststore-
reference" is an instance of the "certificate-bag-ref" discussed
in Section 2.1.2.
2.1.3.4. The "inline-or-truststore-public-keys-grouping" Grouping
The following tree diagram [RFC8340] illustrates the "inline-or-
truststore-public-keys-grouping" grouping:
grouping inline-or-truststore-public-keys-grouping:
+-- (inline-or-truststore)
+--:(inline) {inline-definitions-supported}?
| +-- inline-definition
| +-- public-key* [name]
| +-- name? string
| +---u ct:public-key-grouping
+--:(central-truststore)
{central-truststore-supported,public-keys}?
+-- central-truststore-reference? ts:public-key-bag-ref
Comments:
Watsen Expires 30 June 2024 [Page 9]
Internet-Draft A YANG Data Model for a Truststore December 2023
* The "inline-or-truststore-public-keys-grouping" grouping is
provided soley as convenience to consuming modules that wish to
offer an option whether a bag of public keys can be defined inline
or as a reference to a bag in the truststore.
* A "choice" statement is used to expose the various options. Each
option is enabled by a "feature" statement. Additional "case"
statements MAY be augmented in if, e.g., there is a need to
reference a bag in an alternate location.
* For the "inline-definition" option, the "public-key" node uses the
"public-key-grouping" grouping discussed in Section 2.1.4.4 of
[I-D.ietf-netconf-crypto-types].
* For the "central-truststore" option, the "central-truststore-
reference" is an instance of the "certificate-bag-ref" discussed
in Section 2.1.2.
2.1.3.5. The "truststore-grouping" Grouping
The following tree diagram [RFC8340] illustrates the "truststore-
grouping" grouping:
grouping truststore-grouping:
+-- certificate-bags {certificates}?
| +-- certificate-bag* [name]
| +-- name? string
| +-- description? string
| +-- certificate* [name]
| +-- name? string
| +---u ct:trust-anchor-cert-grouping
+-- public-key-bags {public-keys}?
+-- public-key-bag* [name]
+-- name? string
+-- description? string
+-- public-key* [name]
+-- name? string
+---u ct:public-key-grouping
Comments:
* The "truststore-grouping" grouping defines a truststore instance
as being composed of certificates and/or public keys, both of
which are enabled by "feature" statements. The structure
supporting certificates and public keys is essentially the same,
having an outer list of "bags" containing in inner list of objects
(certificates or public keys). The bags enable trust anchors
serving a common purpose to be grouped and referenced together.
Watsen Expires 30 June 2024 [Page 10]
Internet-Draft A YANG Data Model for a Truststore December 2023
* For certificates, each certificate is defined by the "trust-
anchor-cert-grouping" grouping Section 2.1.4.7 of
[I-D.ietf-netconf-crypto-types]. Thus the "cert-data" node is a
CMS structure that can be composed of a chain of one or more
certificates. Additionally, the "certificate-expiration"
notification enables the server to alert clients when certificates
are nearing or have already expired.
* For public keys, each public key is defined by the "public-key-
grouping" grouping Section 2.1.4.4 of
[I-D.ietf-netconf-crypto-types]. Thus the "public-key" node can
be one of any number of structures specified by the "public-key-
format" identity node.
2.1.4. Protocol-accessible Nodes
The following tree diagram [RFC8340] lists all the protocol-
accessible nodes defined in the "ietf-truststore" module, without
expanding the "grouping" statements:
module: ietf-truststore
+--rw truststore {central-truststore-supported}?
+---u truststore-grouping
The following tree diagram [RFC8340] lists all the protocol-
accessible nodes defined in the "ietf-truststore" module, with all
"grouping" statements expanded, enabling the truststore's full
structure to be seen:
Watsen Expires 30 June 2024 [Page 11]
Internet-Draft A YANG Data Model for a Truststore December 2023
module: ietf-truststore
+--rw truststore {central-truststore-supported}?
+--rw certificate-bags {certificates}?
| +--rw certificate-bag* [name]
| +--rw name string
| +--rw description? string
| +--rw certificate* [name]
| +--rw name string
| +--rw cert-data trust-anchor-cert-cms
| +---n certificate-expiration
| {certificate-expiration-notification}?
| +-- expiration-date yang:date-and-time
+--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 public-key-format identityref
+--rw public-key binary
Comments:
* Protocol-accessible nodes are those nodes that are accessible when
the module is "implemented", as described in Section 5.6.5 of
[RFC7950].
* The protcol-accessible nodes for the "ietf-truststore" module are
an instance of the "truststore-grouping" grouping discussed in
Section 2.1.3.5.
* The top-level node "truststore" is additionally constrained by the
feature "central-truststore-supported".
* The "truststore-grouping" grouping is discussed in
Section 2.1.3.5.
* The reason for why the "truststore-grouping" exists separate from
the protocol-accessible nodes definition is to enable instances of
the truststore to be instantiated in other locations, as may be
needed or desired by some modules.
2.2. Example Usage
The examples in this section are encoded using XML, such as might be
the case when using the NETCONF protocol. Other encodings MAY be
used, such as JSON when using the RESTCONF protocol.
Watsen Expires 30 June 2024 [Page 12]
Internet-Draft A YANG Data Model for a Truststore December 2023
2.2.1. A Truststore Instance
This section presents an example illustrating trust anchors in
<intended>, as per Section 2.1.4. Please see Section 3 for an
example illustrating built-in values in <operational>.
The example contained in this section defines eight bags of trust
anchors. There are four certificate-based bags and four public key
based bags. The following diagram provides an overview of the
contents in the example:
Certificate Bags
+-- Trust anchor certs for authenticating a set of remote servers
+-- End entity certs for authenticating a set of remote servers
+-- Trust anchor certs for authenticating a set of remote clients
+-- End entity certs for authenticating a set of remote clients
Public Key Bags
+-- SSH keys to authenticate a set of remote SSH server
+-- SSH keys to authenticate a set of remote SSH clients
+-- Raw public keys to authenticate a set of remote SSH server
+-- Raw public keys to authenticate a set of remote SSH clients
Following is the full example:
=============== NOTE: '\' line wrapping per RFC 8792 ================
<truststore
xmlns="urn:ietf:params:xml:ns:yang:ietf-truststore"
xmlns:ct="urn:ietf:params:xml:ns:yang:ietf-crypto-types">
<!-- A bag of Certificate Bags -->
<certificate-bags>
<!-- Trust Anchor Certs for Authenticating Servers -->
<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-data>BASE64VALUE=</cert-data>
</certificate>
<certificate>
Watsen Expires 30 June 2024 [Page 13]
Internet-Draft A YANG Data Model for a Truststore December 2023
<name>Server Cert Issuer #2</name>
<cert-data>BASE64VALUE=</cert-data>
</certificate>
</certificate-bag>
<!-- 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-data>BASE64VALUE=</cert-data>
</certificate>
<certificate>
<name>My Application #2</name>
<cert-data>BASE64VALUE=</cert-data>
</certificate>
</certificate-bag>
<!-- Trust Anchor 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-data>BASE64VALUE=</cert-data>
</certificate>
<certificate>
<name>Client Identity Issuer #2</name>
<cert-data>BASE64VALUE=</cert-data>
</certificate>
</certificate-bag>
<!-- End Entity Certs for Authenticating Clients -->
<certificate-bag>
<name>trusted-client-ee-certs</name>
<description>
Specific end-entity certificates used to authenticate client
Watsen Expires 30 June 2024 [Page 14]
Internet-Draft A YANG Data Model for a Truststore December 2023
certificates. A client certificate is authenticated if its
end-entity certificate is an exact match to one of these
certificates.
</description>
<certificate>
<name>George Jetson</name>
<cert-data>BASE64VALUE=</cert-data>
</certificate>
<certificate>
<name>Fred Flintstone</name>
<cert-data>BASE64VALUE=</cert-data>
</certificate>
</certificate-bag>
</certificate-bags>
<!-- A List of Public Key Bags -->
<public-key-bags>
<!-- 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>
<public-key-format>ct:ssh-public-key-format</public-key-form\
at>
<public-key>BASE64VALUE=</public-key>
</public-key>
<public-key>
<name>corp-fw2</name>
<public-key-format>ct:ssh-public-key-format</public-key-form\
at>
<public-key>BASE64VALUE=</public-key>
</public-key>
</public-key-bag>
<!-- SSH Public Keys for Authenticating Application A -->
<public-key-bag>
<name>SSH Public Keys for Application A</name>
<description>
SSH public keys used to authenticate application A's SSH
Watsen Expires 30 June 2024 [Page 15]
Internet-Draft A YANG Data Model for a Truststore December 2023
public keys. An SSH public key is authenticated if it
is an exact match to one of these public keys.
</description>
<public-key>
<name>Application Instance #1</name>
<public-key-format>ct:ssh-public-key-format</public-key-form\
at>
<public-key>BASE64VALUE=</public-key>
</public-key>
<public-key>
<name>Application Instance #2</name>
<public-key-format>ct:ssh-public-key-format</public-key-form\
at>
<public-key>BASE64VALUE=</public-key>
</public-key>
</public-key-bag>
<!-- Raw Public Keys for TLS Servers -->
<public-key-bag>
<name>Raw Public Keys for TLS Servers</name>
<public-key>
<name>Raw Public Key #1</name>
<public-key-format>ct:subject-public-key-info-format</public\
-key-format>
<public-key>BASE64VALUE=</public-key>
</public-key>
<public-key>
<name>Raw Public Key #2</name>
<public-key-format>ct:subject-public-key-info-format</public\
-key-format>
<public-key>BASE64VALUE=</public-key>
</public-key>
</public-key-bag>
<!-- Raw Public Keys for TLS Clients -->
<public-key-bag>
<name>Raw Public Keys for TLS Clients</name>
<public-key>
<name>Raw Public Key #1</name>
<public-key-format>ct:subject-public-key-info-format</public\
-key-format>
<public-key>BASE64VALUE=</public-key>
</public-key>
<public-key>
<name>Raw Public Key #2</name>
<public-key-format>ct:subject-public-key-info-format</public\
-key-format>
<public-key>BASE64VALUE=</public-key>
Watsen Expires 30 June 2024 [Page 16]
Internet-Draft A YANG Data Model for a Truststore December 2023
</public-key>
</public-key-bag>
</public-key-bags>
</truststore>
2.2.2. A Certificate Expiration Notification
The following example illustrates the "certificate-expiration"
notification (per Section 2.1.4.6 of [I-D.ietf-netconf-crypto-types])
for a certificate configured in the truststore in Section 2.2.1.
=============== NOTE: '\' line wrapping per RFC 8792 ================
<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>trusted-client-ee-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>
2.2.3. The "Local or Truststore" Groupings
This section illustrates the various "inline-or-truststore" groupings
defined in the "ietf-truststore" module, specifically the "inline-or-
truststore-certs-grouping" (Section 2.1.3.3) and "inline-or-
truststore-public-keys-grouping" (Section 2.1.3.4) groupings.
These examples assume the existence of an example module called "ex-
truststore-usage" having the namespace "http://example.com/ns/
example-truststore-usage".
The ex-truststore-usage module is first presented using tree diagrams
[RFC8340], followed by an instance example illustrating all the
"inline-or-truststore" groupings in use, followed by the YANG module
itself.
Watsen Expires 30 June 2024 [Page 17]
Internet-Draft A YANG Data Model for a Truststore December 2023
The following tree diagram illustrates "ex-truststore-usage" without
expanding the "grouping" statements:
module: ex-truststore-usage
+--rw truststore-usage
+--rw cert* [name]
| +--rw name string
| +---u ts:inline-or-truststore-certs-grouping
+--rw public-key* [name]
+--rw name string
+---u ts:inline-or-truststore-public-keys-grouping
The following tree diagram illustrates the "ex-truststore-usage"
module, with all "grouping" statements expanded, enabling the
truststore's full structure to be seen:
module: ex-truststore-usage
+--rw truststore-usage
+--rw cert* [name]
| +--rw name string
| +--rw (inline-or-truststore)
| +--:(inline) {inline-definitions-supported}?
| | +--rw inline-definition
| | +--rw certificate* [name]
| | +--rw name string
| | +--rw cert-data
| | | trust-anchor-cert-cms
| | +---n certificate-expiration
| | {certificate-expiration-notification}?
| | +-- expiration-date yang:date-and-time
| +--:(central-truststore)
| {central-truststore-supported,certificates}?
| +--rw central-truststore-reference?
| ts:certificate-bag-ref
+--rw public-key* [name]
+--rw name string
+--rw (inline-or-truststore)
+--:(inline) {inline-definitions-supported}?
| +--rw inline-definition
| +--rw public-key* [name]
| +--rw name string
| +--rw public-key-format identityref
| +--rw public-key binary
+--:(central-truststore)
{central-truststore-supported,public-keys}?
+--rw central-truststore-reference?
ts:public-key-bag-ref
Watsen Expires 30 June 2024 [Page 18]
Internet-Draft A YANG Data Model for a Truststore December 2023
The following example provides two equivalent instances of each
grouping, the first being a reference to a truststore and the second
being defined inline. The instance having a reference to a
truststore is consistent with the truststore defined in
Section 2.2.1. The two instances are equivalent, as the inlined
instance example contains the same values defined by the truststore
instance referenced by its sibling example.
=============== NOTE: '\' line wrapping per RFC 8792 ================
<truststore-usage
xmlns="http://example.com/ns/example-truststore-usage"
xmlns:ct="urn:ietf:params:xml:ns:yang:ietf-crypto-types">
<!-- The following two equivalent examples illustrate -->
<!-- the "inline-or-truststore-certs-grouping" grouping: -->
<cert>
<name>example 1a</name>
<central-truststore-reference>trusted-client-ca-certs</central-t\
ruststore-reference>
</cert>
<cert>
<name>example 1b</name>
<inline-definition>
<name>my-trusted-client-ca-certs</name>
<certificate>
<name>Client Identity Issuer #1</name>
<cert>BASE64VALUE=</cert>
</certificate>
<certificate>
<name>Client Identity Issuer #2</name>
<cert>BASE64VALUE=</cert>
</certificate>
</inline-definition>
</cert>
<!-- The following two equivalent examples illustrate the -->
<!-- "inline-or-truststore-public-keys-grouping" grouping: -->
<public-key>
<name>example 2a</name>
<central-truststore-reference>trusted-ssh-public-keys</central-t\
ruststore-reference>
</public-key>
Watsen Expires 30 June 2024 [Page 19]
Internet-Draft A YANG Data Model for a Truststore December 2023
<public-key>
<name>example 2b</name>
<inline-definition>
<name>trusted-ssh-public-keys</name>
<public-key>
<name>corp-fw1</name>
<public-key-format>
ct:ssh-public-key-format
</public-key-format>
<public-key>BASE64VALUE=</public-key>
</public-key>
<public-key>
<name>corp-fw2</name>
<public-key-format>
ct:ssh-public-key-format
</public-key-format>
<public-key>BASE64VALUE=</public-key>
</public-key>
</inline-definition>
</public-key>
</truststore-usage>
Following is the "ex-truststore-usage" module's YANG definition:
module ex-truststore-usage {
yang-version 1.1;
namespace "http://example.com/ns/example-truststore-usage";
prefix etu;
import ietf-truststore {
prefix ts;
reference
"RFC BBBB: A YANG Data Model for a Truststore";
}
organization
"Example Corporation";
contact
"Author: YANG Designer <mailto:yang.designer@example.com>";
description
"This example module illustrates notable groupings defined
in the 'ietf-truststore' module.";
revision 2023-12-28 {
description
Watsen Expires 30 June 2024 [Page 20]
Internet-Draft A YANG Data Model for a Truststore December 2023
"Initial version";
reference
"RFC BBBB: A YANG Data Model for a Truststore";
}
container truststore-usage {
description
"An illustration of the various truststore groupings.";
list cert {
key "name";
leaf name {
type string;
description
"An arbitrary name for this cert.";
}
uses ts:inline-or-truststore-certs-grouping;
description
"An cert that may be configured locally or be
a reference to a cert in the truststore.";
}
list public-key {
key "name";
leaf name {
type string;
description
"An arbitrary name for this cert.";
}
uses ts:inline-or-truststore-public-keys-grouping;
description
"An public key that may be configured locally or be
a reference to a public key in the truststore.";
}
}
}
2.3. YANG Module
This YANG module imports modules from [RFC8341] and
[I-D.ietf-netconf-crypto-types].
<CODE BEGINS> file "ietf-truststore@2023-12-28.yang"
module ietf-truststore {
yang-version 1.1;
namespace "urn:ietf:params:xml:ns:yang:ietf-truststore";
prefix ts;
import ietf-netconf-acm {
Watsen Expires 30 June 2024 [Page 21]
Internet-Draft A YANG Data Model for a Truststore December 2023
prefix nacm;
reference
"RFC 8341: Network Configuration Access Control Model";
}
import ietf-crypto-types {
prefix ct;
reference
"RFC AAAA: YANG Data Types and Groupings for Cryptography";
}
organization
"IETF NETCONF (Network Configuration) Working Group";
contact
"WG Web : https://datatracker.ietf.org/wg/netconf
WG List : NETCONF WG list <mailto:netconf@ietf.org>
Author : Kent Watsen <kent+ietf@watsen.net>";
description
"This module defines a 'truststore' to centralize management
of trust anchors including certificates and public keys.
Copyright (c) 2023 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 Revised
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 BBBB
(https://www.rfc-editor.org/info/rfcBBBB); 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 2023-12-28 {
description
"Initial version";
reference
Watsen Expires 30 June 2024 [Page 22]
Internet-Draft A YANG Data Model for a Truststore December 2023
"RFC BBBB: A YANG Data Model for a Truststore";
}
/****************/
/* Features */
/****************/
feature central-truststore-supported {
description
"The 'central-truststore-supported' feature indicates that
the server supports the truststore (i.e., implements the
'ietf-truststore' module).";
}
feature inline-definitions-supported {
description
"The 'inline-definitions-supported' feature indicates that
the server supports locally-defined trust anchors.";
}
feature certificates {
description
"The 'certificates' feature indicates that the server
implements the /truststore/certificate-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
in the central truststore.";
}
typedef certificate-ref {
type leafref {
Watsen Expires 30 June 2024 [Page 23]
Internet-Draft A YANG Data Model for a Truststore December 2023
path "/ts:truststore/ts:certificate-bags/ts:certificate-bag"
+ "[ts:name = current()/../certificate-bag]/"
+ "ts:certificate/ts:name";
}
description
"This typedef defines a reference to a specific certificate
in a certificate bag in the central truststore. This typedef
requires that there exist a sibling 'leaf' node called
'certificate-bag' that SHOULD have the typedef
'certificate-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 defines a reference to a public key bag
in the central truststore.";
}
typedef public-key-ref {
type leafref {
path "/ts:truststore/ts:public-key-bags/ts:public-key-bag"
+ "[ts:name = current()/../public-key-bag]/"
+ "ts:public-key/ts:name";
}
description
"This typedef defines a reference to a specific public key
in a public key bag 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 */
/*****************/
// *-ref groupings
grouping certificate-ref-grouping {
description
"Grouping for the reference to a certificate in a
certificate-bag in the central truststore.";
leaf certificate-bag {
nacm:default-deny-write;
Watsen Expires 30 June 2024 [Page 24]
Internet-Draft A YANG Data Model for a Truststore December 2023
if-feature "central-truststore-supported";
if-feature "certificates";
type ts:certificate-bag-ref;
must "../certificate";
description
"Reference to a certificate-bag in the truststore.";
}
leaf certificate {
nacm:default-deny-write;
type ts:certificate-ref;
must "../certificate-bag";
description
"Reference to a specific certificate in the
referenced certificate-bag.";
}
}
grouping public-key-ref-grouping {
description
"Grouping for the reference to a public key in a
public-key-bag in the central truststore.";
leaf public-key-bag {
nacm:default-deny-write;
if-feature "central-truststore-supported";
if-feature "public-keys";
type ts:public-key-bag-ref;
description
"Reference of a public key bag in the truststore inlucding
the certificate to authenticate the TLS client.";
}
leaf public-key {
nacm:default-deny-write;
type ts:public-key-ref;
description
"Reference to a specific public key in the
referenced public-key-bag.";
}
}
// inline-or-truststore-* groupings
grouping inline-or-truststore-certs-grouping {
description
"A grouping for the configuration of a list of certificates.
The list of certificate may be defined inline or as a
reference to a certificate bag in the central truststore.
Servers that do not define the 'central-truststore-supported'
Watsen Expires 30 June 2024 [Page 25]
Internet-Draft A YANG Data Model for a Truststore December 2023
feature SHOULD augment in custom 'case' statements enabling
references to alternate truststore locations.";
choice inline-or-truststore {
nacm:default-deny-write;
mandatory true;
description
"A choice between an inlined definition and a definition
that exists in the truststore.";
case inline {
if-feature "inline-definitions-supported";
container inline-definition {
description
"A container for locally configured trust anchor
certificates.";
list certificate {
key "name";
min-elements 1;
description
"A trust anchor certificate.";
leaf name {
type string;
description
"An arbitrary name for this certificate.";
}
uses ct:trust-anchor-cert-grouping {
refine "cert-data" {
mandatory true;
}
}
}
}
}
case central-truststore {
if-feature "central-truststore-supported";
if-feature "certificates";
leaf central-truststore-reference {
type ts:certificate-bag-ref;
description
"A reference to a certificate bag that exists in the
central truststore.";
}
}
}
}
grouping inline-or-truststore-public-keys-grouping {
description
"A grouping that allows the public keys to be either
Watsen Expires 30 June 2024 [Page 26]
Internet-Draft A YANG Data Model for a Truststore December 2023
configured locally, within the using data model, or be a
reference to a public key bag stored in the truststore.
Servers that do not define the 'central-truststore-supported'
feature SHOULD augment in custom 'case' statements enabling
references to alternate truststore locations.";
choice inline-or-truststore {
nacm:default-deny-write;
mandatory true;
description
"A choice between an inlined definition and a definition
that exists in the truststore.";
case inline {
if-feature "inline-definitions-supported";
container inline-definition {
description
"A 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 central-truststore {
if-feature "central-truststore-supported";
if-feature "public-keys";
leaf central-truststore-reference {
type ts:public-key-bag-ref;
description
"A reference to a bag of public keys that exists
in the central truststore.";
}
}
}
}
// the truststore grouping
grouping truststore-grouping {
description
Watsen Expires 30 June 2024 [Page 27]
Internet-Draft A YANG Data Model for a Truststore December 2023
"A grouping definition that enables use in other contexts.
Where used, implementations MUST augment new 'case'
statements into the various inline-or-truststore 'choice'
statements to supply leafrefs to the model-specific
location(s).";
container certificate-bags {
nacm:default-deny-write;
if-feature "certificates";
description
"A collection of certificate bags.";
list certificate-bag {
key "name";
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";
description
"A trust anchor certificate.";
leaf name {
type string;
description
"An arbitrary name for this certificate.";
}
uses ct:trust-anchor-cert-grouping {
refine "cert-data" {
mandatory true;
}
}
}
}
}
container public-key-bags {
nacm:default-deny-write;
Watsen Expires 30 June 2024 [Page 28]
Internet-Draft A YANG Data Model for a Truststore December 2023
if-feature "public-keys";
description
"A collection of public key bags.";
list public-key-bag {
key "name";
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";
description
"A public key.";
leaf name {
type string;
description
"An arbitrary name for this public key.";
}
uses ct:public-key-grouping;
}
}
}
}
/*********************************/
/* Protocol accessible nodes */
/*********************************/
container truststore {
if-feature central-truststore-supported;
nacm:default-deny-write;
description
"The truststore contains bags of certificates and
public keys.";
uses truststore-grouping;
}
Watsen Expires 30 June 2024 [Page 29]
Internet-Draft A YANG Data Model for a Truststore December 2023
}
<CODE ENDS>
3. Support for Built-in Trust Anchors
In some implementations, a server may define some built-in trust
anchors. For instance, there may be built-in trust anchors enabling
the server to securely connect to well-known services (e.g., an SZTP
[RFC8572] bootstrap server) or public CA certificates to connect to
arbitrary Web services using public PKI.
Built-in trust anchors are expected to be set by a vendor-specific
process. Any ability for operators to set and/or modify built-in
trust anchors is outside the scope of this document.
The primary characteristic of the built-in trust anchors is that they
are provided by the server, as opposed to configuration. As such,
they are present in <operational>, and <system>
[I-D.ietf-netmod-system-config], if implemented.
The example below illustrates what the truststore in <operational>
might look like for a server in its factory default state. Note that
the built-in trust anchor bags have the "or:origin" annotation value
"or:system".
Watsen Expires 30 June 2024 [Page 30]
Internet-Draft A YANG Data Model for a Truststore December 2023
<truststore
xmlns="urn:ietf:params:xml:ns:yang:ietf-truststore"
xmlns:ct="urn:ietf:params:xml:ns:yang:ietf-crypto-types"
xmlns:or="urn:ietf:params:xml:ns:yang:ietf-origin"
or:origin="or:intended">
<certificate-bags>
<certificate-bag or:origin="or:system">
<name>Built-In Manufacturer Trust Anchor Certificates</name>
<description>
Certificates built into the device for authenticating
manufacturer-signed objects, such as TLS server certificates,
vouchers, etc.
</description>
<certificate>
<name>Manufacturer Root CA Cert</name>
<cert-data>BASE64VALUE=</cert-data>
</certificate>
</certificate-bag>
<certificate-bag or:origin="or:system">
<name>Built-In Public Trust Anchor Certificates</name>
<description>
Certificates built into the device for authenticating
certificates issued by public certificate authorities,
such as the end-entity certificate for web servers.
</description>
<certificate>
<name>Public Root CA Cert 1</name>
<cert-data>BASE64VALUE=</cert-data>
</certificate>
<certificate>
<name>Public Root CA Cert 2</name>
<cert-data>BASE64VALUE=</cert-data>
</certificate>
<certificate>
<name>Public Root CA Cert 3</name>
<cert-data>BASE64VALUE=</cert-data>
</certificate>
</certificate-bag>
</certificate-bags>
</truststore>
Built-in bags of trust anchors and/or specific trust anchors, that
are referenced by configuration (e.g., a "leafref"), MUST be present
in a datastore in order for the datastore to be valid.
Watsen Expires 30 June 2024 [Page 31]
Internet-Draft A YANG Data Model for a Truststore December 2023
Built-in bags and/or their trust anchors MAY be copied into other
parts of the configuration but, by doing so, they lose their
association to the built-in entries and any assurances afforded by
knowing they are/were built-in.
The following example illustrates how a single built-in public CA
certificate from the previous example has been propagated to
<intended>:
<truststore
xmlns="urn:ietf:params:xml:ns:yang:ietf-truststore"
xmlns:ct="urn:ietf:params:xml:ns:yang:ietf-crypto-types">
<certificate-bags>
<certificate-bag>
<name>Built-In Public Trust Anchor Certificates</name>
<description>
Certificates built into the device for authenticating
certificates issued by public certificate authorities,
such as the end-entity certificate for web servers.
Only the subset of the certificates that are referenced
by other configuration nodes need to be copied. For
instance, only "Public Root CA Cert 3" is present here.
No new certificates can be added, nor existing certificate
values changed. Missing certificates have no effect on
"operational" when the configuration is applied.
</description>
<certificate>
<name>Public Root CA Cert 3</name>
<cert-data>BASE64VALUE=</cert-data>
</certificate>
</certificate-bag>
</certificate-bags>
</truststore>
4. Security Considerations
4.1. Security of Data at Rest
The YANG module defined in this document defines a mechanism called a
"truststore" that, by its name, suggests that its contents are
protected from unauthorized modification.
Watsen Expires 30 June 2024 [Page 32]
Internet-Draft A YANG Data Model for a Truststore December 2023
Security controls for the API (i.e., data in motion) are discussed in
Section 4.3, but controls for the data at rest (e.g., on disk) cannot
be specified by the YANG module.
In order to satisfy the expectations of a "truststore", it is
RECOMMENDED that implementations ensure that the truststore contents
are protected from unauthorized modifications when at rest.
4.2. Unconstrained Public Key Usage
This module enables the configuration of public keys without
constraints on their usage, e.g., what operations the key is allowed
to be used for (encryption, verification, both).
Trust anchors configured via this module are implicitly trusted to
validate certification paths that may include any name, be used for
any purpose and etc., subject to constraints imposed by an
intermediate CA or by context in which the truststore is used.
Implementations are free to use alternative or auxiliary structures
and validation rules to define constraints that limit the
applicability of any trust anchor.
4.3. The "ietf-truststore" YANG Module
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 Network 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.
None of the readable data nodes defined in this YANG module are
considered sensitive or vulnerable in network environments. The NACM
"default-deny-all" extension has not been set for any data nodes
defined in this module.
All the writable data nodes defined by this module, both in the
"grouping" statements as well as the protocol-accessible "truststore"
instance, may be considered sensitive or vulnerable in some network
environments. For instance, any modification to a trust anchor or
reference to a trust anchor may dramatically alter the implemented
security policy. For this reason, the NACM extension "default-deny-
write" has been set for all data nodes defined in this module.
Watsen Expires 30 June 2024 [Page 33]
Internet-Draft A YANG Data Model for a Truststore December 2023
This module does not define any "rpc" or "action" statements, and
thus the security considerations 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 IESG
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 following
registration is requested:
name: ietf-truststore
namespace: urn:ietf:params:xml:ns:yang:ietf-truststore
prefix: ts
reference: RFC BBBB
6. References
6.1. Normative References
[I-D.ietf-netconf-crypto-types]
Watsen, K., "YANG Data Types and Groupings for
Cryptography", Work in Progress, Internet-Draft, draft-
ietf-netconf-crypto-types-27, 17 April 2023,
<https://datatracker.ietf.org/doc/html/draft-ietf-netconf-
crypto-types-27>.
[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>.
Watsen Expires 30 June 2024 [Page 34]
Internet-Draft A YANG Data Model for a Truststore December 2023
[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
[I-D.ietf-netconf-http-client-server]
Watsen, K., "YANG Groupings for HTTP 1.1/2.0 Clients and
HTTP Servers", Work in Progress, Internet-Draft, draft-
ietf-netconf-http-client-server-13, 17 April 2023,
<https://datatracker.ietf.org/doc/html/draft-ietf-netconf-
http-client-server-13>.
[I-D.ietf-netconf-keystore]
Watsen, K., "A YANG Data Model for a Keystore", Work in
Progress, Internet-Draft, draft-ietf-netconf-keystore-28,
17 April 2023, <https://datatracker.ietf.org/doc/html/
draft-ietf-netconf-keystore-28>.
[I-D.ietf-netconf-netconf-client-server]
Watsen, K., "NETCONF Client and Server Models", Work in
Progress, Internet-Draft, draft-ietf-netconf-netconf-
client-server-29, 17 April 2023,
<https://datatracker.ietf.org/doc/html/draft-ietf-netconf-
netconf-client-server-29>.
[I-D.ietf-netconf-restconf-client-server]
Watsen, K., "RESTCONF Client and Server Models", Work in
Progress, Internet-Draft, draft-ietf-netconf-restconf-
client-server-29, 17 April 2023,
<https://datatracker.ietf.org/doc/html/draft-ietf-netconf-
restconf-client-server-29>.
[I-D.ietf-netconf-ssh-client-server]
Watsen, K., "YANG Groupings for SSH Clients and SSH
Servers", Work in Progress, Internet-Draft, draft-ietf-
netconf-ssh-client-server-33, 17 April 2023,
<https://datatracker.ietf.org/doc/html/draft-ietf-netconf-
ssh-client-server-33>.
[I-D.ietf-netconf-tcp-client-server]
Watsen, K. and M. Scharf, "YANG Groupings for TCP Clients
and TCP Servers", Work in Progress, Internet-Draft, draft-
Watsen Expires 30 June 2024 [Page 35]
Internet-Draft A YANG Data Model for a Truststore December 2023
ietf-netconf-tcp-client-server-16, 17 April 2023,
<https://datatracker.ietf.org/doc/html/draft-ietf-netconf-
tcp-client-server-16>.
[I-D.ietf-netconf-tls-client-server]
Watsen, K., "YANG Groupings for TLS Clients and TLS
Servers", Work in Progress, Internet-Draft, draft-ietf-
netconf-tls-client-server-33, 17 April 2023,
<https://datatracker.ietf.org/doc/html/draft-ietf-netconf-
tls-client-server-33>.
[I-D.ietf-netconf-trust-anchors]
Watsen, K., "A YANG Data Model for a Truststore", Work in
Progress, Internet-Draft, draft-ietf-netconf-trust-
anchors-21, 17 April 2023,
<https://datatracker.ietf.org/doc/html/draft-ietf-netconf-
trust-anchors-21>.
[I-D.ietf-netmod-system-config]
Ma, Q., Wu, Q., and C. Feng, "System-defined
Configuration", Work in Progress, Internet-Draft, draft-
ietf-netmod-system-config-04, 5 November 2023,
<https://datatracker.ietf.org/doc/html/draft-ietf-netmod-
system-config-04>.
[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>.
[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>.
Watsen Expires 30 June 2024 [Page 36]
Internet-Draft A YANG Data Model for a Truststore December 2023
[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>.
Appendix A. Change Log
This section is to be removed before publishing as an RFC.
A.1. 00 to 01
* Added features "x509-certificates" and "ssh-host-keys".
* Added nacm:default-deny-write to "trust-anchors" container.
A.2. 01 to 02
* 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
* Updated copyright date, boilerplate template, affiliation, folding
algorithm, and reformatted the YANG module.
A.4. 03 to 04
* Added groupings 'inline-or-truststore-certs-grouping' and 'inline-
or-truststore-host-keys-grouping', matching similar definitions in
the keystore draft. Note new (and incomplete) "truststore" usage!
* Related to above, also added features 'truststore-supported' and
'local-trust-anchors-supported'.
A.5. 04 to 05
* Renamed "trust-anchors" to "truststore"
* Removed "pinned." prefix everywhere, to match truststore rename
* Moved everything under a top-level 'grouping' to enable use in
other contexts.
Watsen Expires 30 June 2024 [Page 37]
Internet-Draft A YANG Data Model for a Truststore December 2023
* Renamed feature from 'local-trust-anchors-supported' to 'inline-
definitions-supported' (same name used in keystore)
* Removed the "require-instance false" statement from the "*-ref"
typedefs.
* Added missing "ssh-host-keys" and "x509-certificates" if-feature
statements
A.6. 05 to 06
* Editorial changes only.
A.7. 06 to 07
* Added Henk Birkholz as a co-author (thanks Henk!)
* Added PSKs and raw public keys to truststore.
A.8. 07 to 08
* Added new "Support for Built-in Trust Anchors" section.
* Removed spurious "uses ct:trust-anchor-certs-grouping" line.
* Removed PSK from model.
A.9. 08 to 09
* Removed remaining PSK references from text.
* Wrapped each top-level list with a container.
* Introduced "bag" term.
* Merged "SSH Public Keys" and "Raw Public Keys" in a single "Public
Keys" bag. Consuming downstream modules (i.e., "ietf-[ssh/tls]-
[client/server]) refine the "public-key-format" to be either SSH
or TLS specific as needed.
A.10. 09 to 10
* Removed "algorithm" node from examples.
* Removed the no longer used statements supporting the old "ssh-
public-key" and "raw-public-key" nodes.
* Added a "Note to Reviewers" note to first page.
Watsen Expires 30 June 2024 [Page 38]
Internet-Draft A YANG Data Model for a Truststore December 2023
A.11. 10 to 11
* Corrected module prefix registered in the IANA Considerations
section.
* Modified 'inline-or-truststore-certs-grouping' to use a list (not
a leaf-list).
* Added new example section "The Local or Truststore Groupings".
* Clarified expected behavior for "built-in" certificates in
<operational>
* Expanded "Data Model Overview section(s) [remove "wall" of tree
diagrams].
* Updated the Security Considerations section.
A.12. 11 to 12
* Fixed a copy/paste issue in the "Data at Rest" Security
Considerations section.
A.13. 12 to 13
* Fixed issues found by the SecDir review of the "keystore" draft.
A.14. 13 to 14
* Added an "Unconstrained Public Key Usage" Security Consideration
to address concern raised by SecDir.
* Addressed comments raised by YANG Doctor.
A.15. 14 to 15
* Added prefixes to 'path' statements per trust-anchors/issues/1
* Renamed feature "truststore-supported" to "central-truststore-
supported".
* Associated with above, generally moved text to refer to a
"central" truststore.
* Removed two unecessary/unwanted "min-elements 1" and associated
"presence" statements.
* Aligned modules with `pyang -f` formatting.
Watsen Expires 30 June 2024 [Page 39]
Internet-Draft A YANG Data Model for a Truststore December 2023
* Fixed nits found by YANG Doctor reviews.
A.16. 15 to 16
* Replaced "base64encodedvalue==" with "BASE64VALUE=" in examples.
* Minor editorial nits
A.17. 16 to 17
* fixup the 'WG Web' and 'WG List' lines in YANG module(s)
* fixup copyright (i.e., s/Simplified/Revised/) in YANG module(s)
* Added Informative reference to ma-netmod-with-system
A.18. 17 to 18
* Updated Security Considerations section to address comment
received from Carl Wallace.
* Fixed examples to not have line-returns around "identity"
encodings.
* Fixed a couple tree diagrams to not create diagrams for
"groupings" too.
* Added "if-feature central-truststore-supported" to top-level
"trustore" container.
A.19. 18 to 19
* Updated per Shepherd reviews impacting the suite of drafts.
A.20. 19 to 20
* Updated per Shepherd reviews impacting the suite of drafts.
A.21. 20 to 21
* Updated (implicitly) per Tom Petch review.
* Updated per AD's review.
* s/local/inline/ in feature names, grouping names, and node names.
* Updated ref from 'ma-netmod-with-system' to 'ietf-netmod-system-
config'.
Watsen Expires 30 June 2024 [Page 40]
Internet-Draft A YANG Data Model for a Truststore December 2023
* Removed special handling text for built-in certs
* Updated section on built-in trust anchors to read almost the same
as the section in the keystore draft.
A.22. 21 to 22
* Mostly addresses AD review comments.
* Also added typedefs and groupings similar to those created by Alto
WG.
* Added note to Editor to fix line foldings.
* Renamed "truststore" to "central truststore" throughout.
* Removed "built-in" section text that overlaps with the "system-
config" draft.
* Added "certificate-ref-grouping" and "public-key-ref-grouping"
* Modified typedef certificate-ref's leafref path to NOT prefix
"certificate-bag".
* Modified typedef public-key-ref's leafref path to NOT prefix
"public-key-bag".
* Added groupings "certificate-ref-grouping" and "public-key-ref-
grouping".
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 through 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 first name): Balázs Kovács, Carl Wallace,
Eric Voit, Juergen Schoenwaelder, Liang Xia, Martin Björklund, Nick
Hancock, Qin Wu, and Yoav Nir.
Author's Address
Kent Watsen
Watsen Networks
Watsen Expires 30 June 2024 [Page 41]
Internet-Draft A YANG Data Model for a Truststore December 2023
Email: kent+ietf@watsen.net
Watsen Expires 30 June 2024 [Page 42]