Internet-Draft | A YANG Data Model for a Truststore | February 2021 |
Watsen | Expires 14 August 2021 | [Page] |
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.¶
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AAAA
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This document defines a YANG 1.1 [RFC7950] module having the following characteristics:¶
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 the clients and servers of both the NETCONF [RFC6241] and RESTCONF [RFC8040] protocols.¶
The modules have been defined in a modular fashion to enable their use by other efforts, some of which are known to be in progress at the time of this writing, with many more expected to be defined in time.¶
The normative dependency relationship between the various RFCs in the collection is presented in the below diagram. The labels in the diagram represent the primary purpose provided by each RFC. Hyperlinks to each RFC are provided below the diagram.¶
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] |
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.¶
This document in 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).¶
This section defines a YANG 1.1 [RFC7950] module that defines a "truststore" and groupings supporting downstream modules to reference the truststore or have locally-defined definitions.¶
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 illustatrating the module's use are provided in Examples (Section 2.2). The YANG module itself is defined in Section 2.3.¶
This section provides an overview of the "ietf-truststore" module in terms of its features, typedefs, groupings, and protocol-accessible nodes.¶
The following diagram lists all the "feature" statements defined in the "ietf-truststore" module:¶
Features: +-- truststore-supported +-- local-definitions-supported +-- certificates +-- public-keys¶
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¶
Comments:¶
The "ietf-truststore" module defines the following "grouping" statements:¶
Each of these groupings are presented in the following subsections.¶
The following tree diagram [RFC8340] illustrates the "local-or-truststore-certs-grouping" grouping:¶
grouping local-or-truststore-certs-grouping +-- (local-or-truststore) +--:(local) {local-definitions-supported}? | +-- local-definition | +-- certificate* [name] | +-- name? string | +---u ct:trust-anchor-cert-grouping +--:(truststore) {truststore-supported,certificates}? +-- truststore-reference? ts:certificate-bag-ref¶
Comments:¶
The following tree diagram [RFC8340] illustrates the "local-or-truststore-public-keys-grouping" grouping:¶
grouping local-or-truststore-public-keys-grouping +-- (local-or-truststore) +--:(local) {local-definitions-supported}? | +-- local-definition | +-- public-key* [name] | +-- name? string | +---u ct:public-key-grouping +--:(truststore) {truststore-supported,public-keys}? +-- truststore-reference? ts:public-key-bag-ref¶
Comments:¶
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 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 +---u truststore-grouping grouping local-or-truststore-certs-grouping +-- (local-or-truststore) +--:(local) {local-definitions-supported}? | +-- local-definition | +-- certificate* [name] | +-- name? string | +---u ct:trust-anchor-cert-grouping +--:(truststore) {truststore-supported,certificates}? +-- truststore-reference? ts:certificate-bag-ref grouping local-or-truststore-public-keys-grouping +-- (local-or-truststore) +--:(local) {local-definitions-supported}? | +-- local-definition | +-- public-key* [name] | +-- name? string | +---u ct:public-key-grouping +--:(truststore) {truststore-supported,public-keys}? +-- truststore-reference? ts:public-key-bag-ref 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¶
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:¶
module: ietf-truststore +--rw truststore +--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 grouping local-or-truststore-certs-grouping +-- (local-or-truststore) +--:(local) {local-definitions-supported}? | +-- local-definition | +-- certificate* [name] | +-- name? string | +-- cert-data trust-anchor-cert-cms | +---n certificate-expiration | {certificate-expiration-notification}? | +-- expiration-date yang:date-and-time +--:(truststore) {truststore-supported,certificates}? +-- truststore-reference? ts:certificate-bag-ref grouping local-or-truststore-public-keys-grouping +-- (local-or-truststore) +--:(local) {local-definitions-supported}? | +-- local-definition | +-- public-key* [name] | +-- name? string | +-- public-key-format identityref | +-- public-key binary +--:(truststore) {truststore-supported,public-keys}? +-- truststore-reference? ts:public-key-bag-ref grouping truststore-grouping +-- certificate-bags! {certificates}? | +-- certificate-bag* [name] | +-- name? string | +-- description? string | +-- certificate* [name] | +-- name? string | +-- cert-data trust-anchor-cert-cms | +---n certificate-expiration | {certificate-expiration-notification}? | +-- expiration-date yang:date-and-time +-- public-key-bags! {public-keys}? +-- public-key-bag* [name] +-- name? string +-- description? string +-- public-key* [name] +-- name? string +-- public-key-format identityref +-- public-key binary¶
Comments:¶
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.¶
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 secton 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:¶
<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>base64encodedvalue==</cert-data> </certificate> <certificate> <name>Server Cert Issuer #2</name> <cert-data>base64encodedvalue==</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>base64encodedvalue==</cert-data> </certificate> <certificate> <name>My Application #2</name> <cert-data>base64encodedvalue==</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>base64encodedvalue==</cert-data> </certificate> <certificate> <name>Client Identity Issuer #2</name> <cert-data>base64encodedvalue==</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 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>base64encodedvalue==</cert-data> </certificate> <certificate> <name>Fred Flintstone</name> <cert-data>base64encodedvalue==</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-format> <public-key>base64encodedvalue==</public-key> </public-key> <public-key> <name>corp-fw2</name> <public-key-format> ct:ssh-public-key-format </public-key-format> <public-key>base64encodedvalue==</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 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-format> <public-key>base64encodedvalue==</public-key> </public-key> <public-key> <name>Application Instance #2</name> <public-key-format> ct:ssh-public-key-format </public-key-format> <public-key>base64encodedvalue==</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>base64encodedvalue==</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>base64encodedvalue==</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>base64encodedvalue==</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>base64encodedvalue==</public-key> </public-key> </public-key-bag> </public-key-bags> </truststore>¶
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>¶
This section illustrates the various "local-or-truststore" groupings defined in the "ietf-truststore" module, specifically the "local-or-truststore-certs-grouping" (Section 2.1.3.1) and "local-or-truststore-public-keys-grouping" (Section 2.1.3.2) 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 "local-or-truststore" groupings in use, followed by the YANG module itself.¶
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:local-or-truststore-certs-grouping +--rw public-key* [name] +--rw name string +---u ts:local-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 (local-or-truststore) | +--:(local) {local-definitions-supported}? | | +--rw local-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 | +--:(truststore) {truststore-supported,certificates}? | +--rw truststore-reference? ts:certificate-bag-ref +--rw public-key* [name] +--rw name string +--rw (local-or-truststore) +--:(local) {local-definitions-supported}? | +--rw local-definition | +--rw public-key* [name] | +--rw name string | +--rw public-key-format identityref | +--rw public-key binary +--:(truststore) {truststore-supported,public-keys}? +--rw truststore-reference? ts:public-key-bag-ref¶
The following example provides two equivalent instances of each grouping, the first being a reference to a truststore and the second being locally-defined. 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 locally-defined 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 "local-or-truststore-certs-grouping" grouping: --> <cert> <name>example 1a</name> <truststore-reference>trusted-client-ca-certs</truststore-refere\ nce> </cert> <cert> <name>example 1b</name> <local-definition> <name>my-trusted-client-ca-certs</name> <certificate> <name>Client Identity Issuer #1</name> <cert>base64encodedvalue==</cert> </certificate> <certificate> <name>Client Identity Issuer #2</name> <cert>base64encodedvalue==</cert> </certificate> </local-definition> </cert> <!-- The following two equivalent examples illustrate the --> <!-- "local-or-truststore-public-keys-grouping" grouping: --> <public-key> <name>example 2a</name> <truststore-reference>trusted-ssh-public-keys</truststore-refere\ nce> </public-key> <public-key> <name>example 2b</name> <local-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>base64encodedvalue==</public-key> </public-key> <public-key> <name>corp-fw2</name> <public-key-format> ct:ssh-public-key-format </public-key-format> <public-key>base64encodedvalue==</public-key> </public-key> </local-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 module illustrates notable groupings defined in the 'ietf-truststore' module."; revision "2021-02-10" { description "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:local-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:local-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."; } } }¶
This YANG module imports modules from [RFC8341] and [I-D.ietf-netconf-crypto-types].¶
<CODE BEGINS> file "ietf-truststore@2021-02-10.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 AAAA: YANG Data Types and Groupings for Cryptography"; } organization "IETF NETCONF (Network Configuration) Working Group"; contact "WG Web : <http://datatracker.ietf.org/wg/netconf/> WG List : <mailto:netconf@ietf.org> Author : Kent Watsen <kent+ietf@watsen.net>"; description "This module defines a 'truststore' to centralize management of trust anchors including certificates and public keys. Copyright (c) 2020 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 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 2021-02-10 { description "Initial version"; reference "RFC BBBB: 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)."; } feature local-definitions-supported { description "The 'local-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 truststore, when this module is implemented."; } typedef certificate-ref { type leafref { path "/ts:truststore/certificate-bags/certificate-bag" + "[name = current()/../certificate-bag]/certificate/name"; } description "This typedef defines a reference to a specific certificate in a certificate bag in the truststore, when this module is implemented. 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 truststore, when this module is implemented."; } 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 defines a reference to a specific public key in a public key bag in the truststore, when this module is implemented. 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. Servers that do not 'implement' this module, and hence 'truststore-supported' is not defined, SHOULD augment in custom 'case' statements enabling references to the alternate truststore locations."; choice local-or-truststore { nacm:default-deny-write; mandatory true; description "A choice between an inlined definition and a definition that exists in the truststore."; case local { if-feature "local-definitions-supported"; container local-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 truststore { if-feature "truststore-supported"; if-feature "certificates"; leaf truststore-reference { type ts:certificate-bag-ref; description "A reference to a certificate bag that exists in the truststore, when this module is implemented."; } } } } 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. Servers that do not 'implement' this module, and hence 'truststore-supported' is not defined, SHOULD augment in custom 'case' statements enabling references to the alternate truststore locations."; choice local-or-truststore { nacm:default-deny-write; mandatory true; description "A choice between an inlined definition and a definition that exists in the truststore."; case local { if-feature "local-definitions-supported"; container local-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 truststore { if-feature "truststore-supported"; if-feature "public-keys"; leaf truststore-reference { type ts:public-key-bag-ref; description "A reference to a bag of public keys that exists in the truststore, when this module is implemented."; } } } } grouping truststore-grouping { description "A grouping definition that enables use in other contexts. Where used, implementations MUST augment new 'case' statements into the various local-or-truststore 'choice' statements to supply leafrefs to the model-specific location(s)."; container certificate-bags { nacm:default-deny-write; if-feature "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 { 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; 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 */ /*********************************/ container truststore { nacm:default-deny-write; description "The truststore contains bags of certificates and public keys."; uses truststore-grouping; } }¶
<CODE ENDS>¶
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 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 document.¶
As built-in trust anchors are provided by the server, they are present in <operational>. The example below illustrates what the truststore in <operational> might look like for a server in its factory default state.¶
<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>base64encodedvalue==</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>base64encodedvalue==</cert-data> </certificate> <certificate> <name>Public Root CA Cert 2</name> <cert-data>base64encodedvalue==</cert-data> </certificate> <certificate> <name>Public Root CA Cert 3</name> <cert-data>base64encodedvalue==</cert-data> </certificate> </certificate-bag> </certificate-bags> </truststore>¶
In order for the built-in bags of trust anchors and/or their trust anchors to be referenced by configuration, they MUST first be copied into <running>.¶
The built-in bags and/or their trust anchors MUST be copied into <running> using the same "key" values if it is desired for the server to maintain/update them (e.g., a software update may update a bag of trusted public CA certificates used for TLS-client connections).¶
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 built-in bags and/or their trust anchors are immutable by configuration operations. Servers MUST ignore attempts to modify any aspect of built-in bags and/or their trust anchors from <running>.¶
The following example illustrates how a single built-in public CA certificate from the previous example has been propagated to <running>:¶
<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>base64encodedvalue==</cert-data> </certificate> </certificate-bag> </certificate-bags> </truststore>¶
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.¶
Security controls for the API (i.e., data in motion) are discussed in Section 4.3, but controls for the data at rest 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.¶
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).¶
This module also enables the configuration of certificates, where each certificate may constrain the usage of the public key according to local policy.¶
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.¶
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 of 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.¶
This module does not define any "rpc" or "action" statements, and thus the security considerations for such is not provided here.¶
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.¶
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¶
This section is to be removed before publishing as an RFC.¶
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 first name): Balazs Kovacs, Eric Voit, Juergen Schoenwaelder, Liang Xia, Martin Bjorklund, Nick Hancock, and Yoav Nir.¶