NETCONF Working Group K. Watsen Internet-Draft Watsen Networks Intended status: Standards Track March 8, 2020 Expires: September 9, 2020 A YANG Data Model for a Truststore draft-ietf-netconf-trust-anchors-09 Abstract This document defines a YANG 1.1 data model for configuring global sets of X.509 certificates, SSH host-keys, and raw public keys that can be referenced by other data models for trust. While the SSH host-keys are uniquely for the SSH protocol, certificates, and raw public keys may have multiple uses, including authenticating protocol peers and verifying signatures. Editorial Note (To be removed by RFC Editor) This draft contains many placeholder values that need to be replaced with finalized values at the time of publication. This note summarizes all of the substitutions that are needed. No other RFC Editor instructions are specified elsewhere in this document. Artwork in this document contains shorthand references to drafts in progress. Please apply the following replacements: o "XXXX" --> the assigned RFC value for this draft o "YYYY" --> the assigned RFC value for draft-ietf-netconf-crypto- types Artwork in this document contains placeholder values for the date of publication of this draft. Please apply the following replacement: o "2020-03-08" --> the publication date of this draft The following Appendix section is to be removed prior to publication: o Appendix A. Change Log Status of This Memo This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79. Watsen Expires September 9, 2020 [Page 1] Internet-Draft A YANG Data Model for a Truststore March 2020 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 September 9, 2020. Copyright Notice Copyright (c) 2020 IETF Trust and the persons identified as the document authors. All rights reserved. This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (https://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 1.1. Requirements Language . . . . . . . . . . . . . . . . . . 3 1.2. Tree Diagram Notation . . . . . . . . . . . . . . . . . . 3 2. The Trust Anchors Model . . . . . . . . . . . . . . . . . . . 3 2.1. Tree Diagram . . . . . . . . . . . . . . . . . . . . . . 3 2.2. Example Usage . . . . . . . . . . . . . . . . . . . . . . 6 2.3. YANG Module . . . . . . . . . . . . . . . . . . . . . . . 12 3. Support for Built-in Trust Anchors . . . . . . . . . . . . . 24 4. Security Considerations . . . . . . . . . . . . . . . . . . . 24 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 25 5.1. The IETF XML Registry . . . . . . . . . . . . . . . . . . 25 5.2. The YANG Module Names Registry . . . . . . . . . . . . . 25 6. References . . . . . . . . . . . . . . . . . . . . . . . . . 26 6.1. Normative References . . . . . . . . . . . . . . . . . . 26 6.2. Informative References . . . . . . . . . . . . . . . . . 26 Appendix A. Change Log . . . . . . . . . . . . . . . . . . . . . 28 A.1. 00 to 01 . . . . . . . . . . . . . . . . . . . . . . . . 28 A.2. 01 to 02 . . . . . . . . . . . . . . . . . . . . . . . . 28 A.3. 02 to 03 . . . . . . . . . . . . . . . . . . . . . . . . 28 Watsen Expires September 9, 2020 [Page 2] Internet-Draft A YANG Data Model for a Truststore March 2020 A.4. 03 to 04 . . . . . . . . . . . . . . . . . . . . . . . . 28 A.5. 04 to 05 . . . . . . . . . . . . . . . . . . . . . . . . 28 A.6. 05 to 06 . . . . . . . . . . . . . . . . . . . . . . . . 29 A.7. 06 to 07 . . . . . . . . . . . . . . . . . . . . . . . . 29 A.8. 07 to 08 . . . . . . . . . . . . . . . . . . . . . . . . 29 A.9. 08 to 09 . . . . . . . . . . . . . . . . . . . . . . . . 29 Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . 29 Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 30 1. Introduction This document defines a YANG 1.1 [RFC7950] data model for configuring global sets of X.509 certificates, SSH host-keys, and raw public keys that can be referenced by other data models for trust. While the SSH host-keys are uniquely for the SSH protocol, certificates, and raw public keys may have multiple uses, including authenticating protocol peers and verifying signatures. This document in compliant with Network Management Datastore Architecture (NMDA) [RFC8342]. For instance, trust anchors installed during manufacturing (e.g., for trusted well-known services), are expected to appear in (see Section 3). 1.1. Requirements Language The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all capitals, as shown here. 1.2. Tree Diagram Notation Tree diagrams used in this document follow the notation defined in [RFC8340]. 2. The Trust Anchors Model 2.1. Tree Diagram The following tree diagram provides an overview of the "ietf- truststore" module. module: ietf-truststore +--rw truststore +--rw certificate-bags! {x509-certificates}? | +--rw certificate-bag* [name] | +--rw name string Watsen Expires September 9, 2020 [Page 3] Internet-Draft A YANG Data Model for a Truststore March 2020 | +--rw description? string | +--rw certificate* [name] | +--rw name string | +--rw cert trust-anchor-cert-cms | +---n certificate-expiration | +-- expiration-date yang:date-and-time +--rw ssh-public-key-bags! {ssh-public-keys}? | +--rw ssh-public-key-bag* [name] | +--rw name string | +--rw description? string | +--rw ssh-public-key* [name] | +--rw name string | +--rw algorithm | | iasa:asymmetric-algorithm-type | +--rw public-key-format identityref | +--rw public-key binary +--rw raw-public-key-bags! {raw-public-keys}? | +--rw raw-public-key-bag* [name] | +--rw name string | +--rw description? string | +--rw raw-public-key* [name] | +--rw name string | +--rw algorithm | | iasa:asymmetric-algorithm-type | +--rw public-key-format identityref | +--rw public-key binary +--rw public-key-bags! {public-keys}? +--rw public-key-bag* [name] +--rw name string +--rw description? string +--rw public-key* [name] +--rw name string +--rw algorithm | iasa:asymmetric-algorithm-type +--rw public-key-format identityref +--rw public-key binary grouping local-or-truststore-certs-grouping +-- (local-or-truststore) +--:(local) {local-definitions-supported}? | +-- local-definition | +-- cert* trust-anchor-cert-cms | +---n certificate-expiration | +-- expiration-date yang:date-and-time +--:(truststore) {truststore-supported,x509-certificates}? +-- truststore-reference? ts:certificate-bag-ref grouping local-or-truststore-ssh-public-keys-grouping +-- (local-or-truststore) Watsen Expires September 9, 2020 [Page 4] Internet-Draft A YANG Data Model for a Truststore March 2020 +--:(local) {local-definitions-supported}? | +-- local-definition | +-- ssh-public-key* [name] | +-- name? string | +-- algorithm | | iasa:asymmetric-algorithm-type | +-- public-key-format identityref | +-- public-key binary +--:(truststore) {truststore-supported,ssh-public-keys}? +-- truststore-reference? ts:ssh-public-key-bag-ref grouping local-or-truststore-raw-pub-keys-grouping +-- (local-or-truststore) +--:(local) {local-definitions-supported}? | +-- local-definition | +-- raw-public-key* [name] | +-- name? string | +-- algorithm | | iasa:asymmetric-algorithm-type | +-- public-key-format identityref | +-- public-key binary +--:(truststore) {truststore-supported,raw-public-keys}? +-- truststore-reference? ts:raw-public-key-bag-ref grouping local-or-truststore-public-keys-grouping +-- (local-or-truststore) +--:(local) {local-definitions-supported}? | +-- local-definition | +-- public-key* [name] | +-- name? string | +-- algorithm | | iasa:asymmetric-algorithm-type | +-- public-key-format identityref | +-- public-key binary +--:(truststore) {truststore-supported,public-keys}? +-- truststore-reference? ts:public-key-bag-ref grouping truststore-grouping +-- certificate-bags! {x509-certificates}? | +-- certificate-bag* [name] | +-- name? string | +-- description? string | +-- certificate* [name] | +-- name? string | +-- cert trust-anchor-cert-cms | +---n certificate-expiration | +-- expiration-date yang:date-and-time +-- ssh-public-key-bags! {ssh-public-keys}? | +-- ssh-public-key-bag* [name] | +-- name? string | +-- description? string Watsen Expires September 9, 2020 [Page 5] Internet-Draft A YANG Data Model for a Truststore March 2020 | +-- ssh-public-key* [name] | +-- name? string | +-- algorithm iasa:asymmetric-algorithm-type | +-- public-key-format identityref | +-- public-key binary +-- raw-public-key-bags! {raw-public-keys}? | +-- raw-public-key-bag* [name] | +-- name? string | +-- description? string | +-- raw-public-key* [name] | +-- name? string | +-- algorithm iasa:asymmetric-algorithm-type | +-- public-key-format identityref | +-- public-key binary +-- public-key-bags! {public-keys}? +-- public-key-bag* [name] +-- name? string +-- description? string +-- public-key* [name] +-- name? string +-- algorithm iasa:asymmetric-algorithm-type +-- public-key-format identityref +-- public-key binary 2.2. Example Usage The following example illustrates trust anchors in . Please see Section 3 for an example illustrating built-in values in . ========== NOTE: '\' line wrapping per BCP XXX (RFC XXXX) =========== manufacturers-root-ca-certs Certificates built into the device for authenticating manufacturer-signed objects, such as TLS server certificates, vouchers, etc. Note, though listed here, these are not configurable; any attempt to do so will be denied. Watsen Expires September 9, 2020 [Page 6] Internet-Draft A YANG Data Model for a Truststore March 2020 Manufacturer Root CA cert 1 base64encodedvalue== Manufacturer Root CA cert 2 base64encodedvalue== common-ca-certs 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. Go Daddy Class 2 Certification Authority base64encodedvalue== VeriSign Universal Root Certification Authority base64encodedvalue== trusted-server-ca-certs 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. Server Cert Issuer #1 base64encodedvalue== Server Cert Issuer #2 base64encodedvalue== Watsen Expires September 9, 2020 [Page 7] Internet-Draft A YANG Data Model for a Truststore March 2020 trusted-server-ee-certs 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. My Application #1 base64encodedvalue== My Application #2 base64encodedvalue== trusted-client-ca-certs 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. Client Identity Issuer #1 base64encodedvalue== Client Identity Issuer #2 base64encodedvalue== trusted-client-ee-certs 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. Watsen Expires September 9, 2020 [Page 8] Internet-Draft A YANG Data Model for a Truststore March 2020 George Jetson base64encodedvalue== Fred Flintstone base64encodedvalue== trusted-ssh-public-keys 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. corp-fw1 secp256r1 ct:ssh-public-key-format base64encodedvalue== corp-fw2 secp256r1 ct:ssh-public-key-format base64encodedvalue== SSH Public Keys for User A SSH public keys used to authenticate a user A's SSH public keys. An SSH public key is authenticated if it is an exact match to one of these public keys. Watsen Expires September 9, 2020 [Page 9] Internet-Draft A YANG Data Model for a Truststore March 2020 This list of public keys is analogous to OpenSSH's "~A/.ssh/authorized_keys" file. From Source #1 secp256r1 ct:ssh-public-key-format base64encodedvalue== From Source #2 secp256r1 ct:ssh-public-key-format base64encodedvalue== SSH Public Keys for User B SSH public keys used to authenticate a user B's SSH public keys. An SSH public key is authenticated if it is an exact match to one of these public keys. This list of public keys is analogous to OpenSSH's "~B/.ssh/authorized_keys" file. From Source #1 secp256r1 ct:ssh-public-key-format base64encodedvalue== From Source #2 secp256r1 ct:ssh-public-key-format base64encodedvalue== Watsen Expires September 9, 2020 [Page 10] Internet-Draft A YANG Data Model for a Truststore March 2020 Raw Public Keys for Servers FIXME... Raw Public Key #1 rsa2048 ct:subject-public-key-info-format base64encodedvalue== Raw Public Key #2 rsa2048 ct:subject-public-key-info-format base64encodedvalue== Raw Public Keys for Clients FIXME... Raw Public Key #1 rsa2048 ct:subject-public-key-info-format base64encodedvalue== Raw Public Key #2 rsa2048 ct:subject-public-key-info-format base64encodedvalue== The following example illustrates the "certificate-expiration" notification in use with the NETCONF protocol. Watsen Expires September 9, 2020 [Page 11] Internet-Draft A YANG Data Model for a Truststore March 2020 ========== NOTE: '\' line wrapping per BCP XXX (RFC XXXX) =========== 2018-05-25T00:01:00Z explicitly-trusted-client-certs George Jetson 2018-08-05T14:18:53-05:00 2.3. YANG Module This YANG module imports modules from [RFC8341] and [I-D.ietf-netconf-crypto-types]. file "ietf-truststore@2020-03-08.yang" module ietf-truststore { yang-version 1.1; namespace "urn:ietf:params:xml:ns:yang:ietf-truststore"; prefix ts; import ietf-netconf-acm { prefix nacm; reference "RFC 8341: Network Configuration Access Control Model"; } import ietf-crypto-types { prefix ct; reference "RFC YYYY: Common YANG Data Types for Cryptography"; } organization "IETF NETCONF (Network Configuration) Working Group"; Watsen Expires September 9, 2020 [Page 12] Internet-Draft A YANG Data Model for a Truststore March 2020 contact "WG Web : WG List : Author : Kent Watsen Author : Henk Birkholz "; description "This module defines a truststore to centralize management of trust anchors including X.509 certificates, SSH public keys, raw public keys. Copyright (c) 2019 IETF Trust and the persons identified as authors of the code. All rights reserved. Redistribution and use in source and binary forms, with or without modification, is permitted pursuant to, and subject to the license terms contained in, the Simplified BSD License set forth in Section 4.c of the IETF Trust's Legal Provisions Relating to IETF Documents (https://trustee.ietf.org/license-info). This version of this YANG module is part of RFC XXXX (https://www.rfc-editor.org/info/rfcXXXX); see the RFC itself for full legal notices. The key words 'MUST', 'MUST NOT', 'REQUIRED', 'SHALL', 'SHALL NOT', 'SHOULD', 'SHOULD NOT', 'RECOMMENDED', 'NOT RECOMMENDED', 'MAY', and 'OPTIONAL' in this document are to be interpreted as described in BCP 14 (RFC 2119) (RFC 8174) when, and only when, they appear in all capitals, as shown here."; revision 2020-03-08 { description "Initial version"; reference "RFC XXXX: A YANG Data Model for a Truststore"; } /****************/ /* Features */ /****************/ feature truststore-supported { description "The 'truststore-supported' feature indicates that the server supports the truststore (i.e., implements the 'ietf-truststore' module)."; Watsen Expires September 9, 2020 [Page 13] Internet-Draft A YANG Data Model for a Truststore March 2020 } feature local-definitions-supported { description "The 'local-definitions-supported' feature indicates that the server supports locally-defined trust anchors."; } feature x509-certificates { description "The 'x509-certificates' feature indicates that the server implements the /truststore/certificate-bags subtree."; } feature ssh-public-keys { description "The 'ssh-public-keys' feature indicates that the server implements the /truststore/ssh-public-key-bags subtree."; } feature raw-public-keys { description "The 'raw-public-keys' feature indicates that the server implements the /truststore/raw-public-key-bags subtree."; } feature public-keys { description "The 'public-keys' feature indicates that the server implements the /truststore/public-key-bags subtree."; } /****************/ /* Typedefs */ /****************/ typedef certificate-bag-ref { type leafref { path "/ts:truststore/ts:certificate-bags/" + "ts:certificate-bag/ts:name"; } description "This typedef defines a reference to a certificate bag defined in the truststore."; } typedef certificate-ref { type leafref { Watsen Expires September 9, 2020 [Page 14] Internet-Draft A YANG Data Model for a Truststore March 2020 path "/ts:truststore/certificate-bags/certificate-bag" + "[name = current()/../certificate-bag]/certificate/name"; } description "This typedef define a reference to a specific certificate in a certificate bag defined in the truststore. This typedef requires that there exist a sibling 'leaf' node called 'certificate-bag' that SHOULD have the typedef 'certificate-bag-ref'."; } typedef ssh-public-key-bag-ref { type leafref { path "/ts:truststore/ts:ssh-public-key-bags" + "/ts:ssh-public-key-bag/ts:name"; } description "This typedef defines a reference to an SSH public key bag defined in the truststore."; } typedef ssh-public-key-ref { type leafref { path "/ts:truststore/ssh-public-key-bags/ssh-public-key-bag" + "[name = current()/../ssh-public-key-bag]" + "/ssh-public-key/name"; } description "This typedef define a reference to a specific SSH public key in a SSH public key bag defined in the truststore. This typedef requires that there exist a sibling 'leaf' node called 'ssh-public-key-bag' that SHOULD have the typedef 'ssh-public-key-bag-ref'."; } typedef raw-public-key-bag-ref { type leafref { path "/ts:truststore/ts:raw-public-key-bags/" + "ts:raw-public-key-bag/ts:name"; } description "This typedef define a reference to a raw public key bag defined in the truststore."; } typedef raw-public-key-ref { type leafref { path "/ts:truststore/raw-public-key-bags/raw-public-key-bag" + Watsen Expires September 9, 2020 [Page 15] Internet-Draft A YANG Data Model for a Truststore March 2020 "[name = current()/../raw-public-key-bag]/" + "raw-public-key/name"; } description "This typedef define a reference to a specific raw public key in a raw public key bag defined in the truststore. This typedef requires that there exist a sibling 'leaf' node called 'raw-public-key-bag' that SHOULD have the typedef 'raw-public-key-bag-ref'."; } typedef public-key-bag-ref { type leafref { path "/ts:truststore/ts:public-key-bags/" + "ts:public-key-bag/ts:name"; } description "This typedef define a reference to a public key bag defined in the truststore."; } typedef public-key-ref { type leafref { path "/ts:truststore/public-key-bags/public-key-bag" + "[name = current()/../public-key-bag]/" + "public-key/name"; } description "This typedef define a reference to a specific public key in a public key bag defined in the truststore. This typedef requires that there exist a sibling 'leaf' node called 'public-key-bag' that SHOULD have the typedef 'public-key-bag-ref'."; } /*****************/ /* Groupings */ /*****************/ grouping local-or-truststore-certs-grouping { description "A grouping that allows the certificates to be either configured locally, within the using data model, or be a reference to a certificate bag stored in the truststore."; choice local-or-truststore { mandatory true; case local { Watsen Expires September 9, 2020 [Page 16] Internet-Draft A YANG Data Model for a Truststore March 2020 if-feature "local-definitions-supported"; container local-definition { description "A container for locally configured trust anchor certificates."; uses ct:trust-anchor-certs-grouping; } } case truststore { if-feature "truststore-supported"; if-feature "x509-certificates"; leaf truststore-reference { type ts:certificate-bag-ref; description "A reference to a certificate bag that exists in the truststore."; } } description "A choice between an inlined definition and a definition that exists in the truststore."; } } grouping local-or-truststore-ssh-public-keys-grouping { description "A grouping that allows the ssh public keys to be either configured locally, within the using data model, or be a reference to a ssh public key bag stored in the truststore."; choice local-or-truststore { mandatory true; case local { if-feature "local-definitions-supported"; container local-definition { description "Container to hold local ssh public key definitions."; list ssh-public-key { key name; min-elements 1; description "A ssh public key."; leaf name { type string; description "An arbitrary name for this ssh public key."; } uses ct:public-key-grouping { refine "public-key-format" { Watsen Expires September 9, 2020 [Page 17] Internet-Draft A YANG Data Model for a Truststore March 2020 must '. = "ct:ssh-public-key-format"'; } } } } } case truststore { if-feature "truststore-supported"; if-feature "ssh-public-keys"; leaf truststore-reference { type ts:ssh-public-key-bag-ref; description "A reference to a bag of SSH public keys that exist in the truststore."; } } description "A choice between an inlined definition and a definition that exists in the truststore."; } } grouping local-or-truststore-raw-pub-keys-grouping { description "A grouping that allows the raw public keys to be either configured locally, within the using data model, or be a reference to a raw public key bag stored in the truststore."; choice local-or-truststore { mandatory true; case local { if-feature "local-definitions-supported"; container local-definition { description "Container to hold local raw public key definitions."; list raw-public-key { key name; description "A raw public key definition."; leaf name { type string; description "An arbitrary name for this raw public key."; } uses ct:public-key-grouping; } } } Watsen Expires September 9, 2020 [Page 18] Internet-Draft A YANG Data Model for a Truststore March 2020 case truststore { if-feature "truststore-supported"; if-feature "raw-public-keys"; leaf truststore-reference { type ts:raw-public-key-bag-ref; description "A reference to a bag of raw public keys that exist in the truststore."; } } description "A choice between an inlined definition and a definition that exists in the truststore."; } } grouping local-or-truststore-public-keys-grouping { description "A grouping that allows the public keys to be either configured locally, within the using data model, or be a reference to a public key bag stored in the truststore."; choice local-or-truststore { mandatory true; case local { if-feature "local-definitions-supported"; container local-definition { description "Container to hold local public key definitions."; list public-key { key name; description "A public key definition."; leaf name { type string; description "An arbitrary name for this public key."; } uses ct:public-key-grouping; } } } case truststore { if-feature "truststore-supported"; if-feature "public-keys"; leaf truststore-reference { type ts:public-key-bag-ref; description Watsen Expires September 9, 2020 [Page 19] Internet-Draft A YANG Data Model for a Truststore March 2020 "A reference to a bag of public keys that exist in the truststore."; } } description "A choice between an inlined definition and a definition that exists in the truststore."; } } grouping truststore-grouping { description "Grouping definition enables use in other contexts. Where used, implementations SHOULD augment new 'case' statements into the local-or-truststore 'choice' statements to supply leafrefs to the model-specific location."; container certificate-bags { if-feature "x509-certificates"; presence "Indicates that certificate bags have been configured."; description "A collection of certificate bags."; list certificate-bag { key "name"; min-elements 1; description "A bag of certificates. Each bag of certificates SHOULD be for a specific purpose. For instance, one bag could be used to authenticate a specific set of servers, while another could be used to authenticate a specific set of clients."; leaf name { type string; description "An arbitrary name for this bag of certificates."; } leaf description { type string; description "A description for this bag of certificates. The intended purpose for the bag SHOULD be described."; } list certificate { key "name"; min-elements 1; description "A trust anchor certificate."; leaf name { Watsen Expires September 9, 2020 [Page 20] Internet-Draft A YANG Data Model for a Truststore March 2020 type string; description "An arbitrary name for this certificate."; } uses ct:trust-anchor-cert-grouping { refine "cert" { mandatory true; } } } } } container ssh-public-key-bags { if-feature "ssh-public-keys"; presence "Indicates that SSH public keys have been configured."; description "A collection of SSH public key bags."; list ssh-public-key-bag { key "name"; min-elements 1; description "A bag of SSH public keys. Each bag of SSH public keys SHOULD be for a specific purpose. For instance, one bag could be used authenticate a specific set of servers (i.e., host keys), while another bag could be used to authenticate a specific client or set of clients."; leaf name { type string; description "An arbitrary name for this bag of SSH public keys."; } leaf description { type string; description "A description for this bag of SSH public keys. The intended purpose for the bag SHOULD be described."; } list ssh-public-key { key "name"; min-elements 1; description "An SSH public key."; leaf name { type string; description "An arbitrary name for this SSH public key."; } Watsen Expires September 9, 2020 [Page 21] Internet-Draft A YANG Data Model for a Truststore March 2020 uses ct:public-key-grouping { refine "public-key-format" { must '. = "ct:ssh-public-key-format"'; } } } } } container raw-public-key-bags { if-feature "raw-public-keys"; presence "Indicates that raw public keys have been configured."; description "A collection of raw public key bags."; list raw-public-key-bag { key "name"; min-elements 1; description "A bag of raw public keys. Each bag of keys SHOULD be for a specific purpose. For instance, one bag could be used authenticate a specific set of servers, while another could be used to authenticate a specific set of clients."; leaf name { type string; description "An arbitrary name for this bag of raw public keys."; } leaf description { type string; description "A description for this bag raw public keys. The intended purpose for the bag SHOULD be described."; } list raw-public-key { key "name"; min-elements 1; description "A raw public key."; leaf name { type string; description "An arbitrary name for this raw public key."; } uses ct:public-key-grouping { refine "public-key-format" { must '. = "ct:subject-public-key-info-format"'; } } Watsen Expires September 9, 2020 [Page 22] Internet-Draft A YANG Data Model for a Truststore March 2020 //uses ct:public-key-grouping; } } } container public-key-bags { if-feature "public-keys"; presence "Indicates that public keys have been configured."; description "A collection of public key bags."; list public-key-bag { key "name"; min-elements 1; description "A bag of public keys. Each bag of keys SHOULD be for a specific purpose. For instance, one bag could be used authenticate a specific set of servers, while another could be used to authenticate a specific set of clients."; leaf name { type string; description "An arbitrary name for this bag of public keys."; } leaf description { type string; description "A description for this bag public keys. The intended purpose for the bag SHOULD be described."; } list public-key { key "name"; min-elements 1; description "A public key."; leaf name { type string; description "An arbitrary name for this public key."; } uses ct:public-key-grouping; } } } } /*********************************/ /* Protocol accessible nodes */ /*********************************/ Watsen Expires September 9, 2020 [Page 23] Internet-Draft A YANG Data Model for a Truststore March 2020 container truststore { nacm:default-deny-write; description "The truststore contains sets of X.509 certificates, SSH public keys, and raw public keys."; uses truststore-grouping; } } 3. Support for Built-in Trust Anchors In some implementations, the operating system a device is running, may define some built-in trust anchors. For instance, there may be built-in trust anchors enabling the device to securely connect to well-known services (e.g., an SZTP [RFC8572] bootstap server) or trust anchors to connect to arbitrary services using public PKI. Built-in trust anchors are expected to be set by a vendor-specific process. Any ability for operators to modify built-in trust anchors is outside the scope of this docuemnt. As built-in trust anchors are provided by the system (not configuration), they are present in . The following example illustrates bui;t-in trust anchors in . (FIXME: add illustration with origin="system" here) In order for the built-in trust anchors to be referenced by configuration, they must first be copied into as the example in Section 2.2 illustrates for the built-in trust anchors above. Note that this strategy is chosen, rather then setting "require-instance false" for the various leafrefs, as built-in trust anchors are relatively few in number and hence not worth relaxing the validation for. 4. Security Considerations The YANG module defined in this document is designed to be accessed via YANG based management protocols, such as NETCONF [RFC6241] and RESTCONF [RFC8040]. Both of these protocols have mandatory-to- implement secure transport layers (e.g., SSH, TLS) with mutual authentication. The NETCONF access control model (NACM) [RFC8341] provides the means to restrict access for particular users to a pre-configured subset of all available protocol operations and content. Watsen Expires September 9, 2020 [Page 24] Internet-Draft A YANG Data Model for a Truststore March 2020 There are a number of data nodes defined in this YANG module that are writable/creatable/deletable (i.e., config true, which is the default). These data nodes may be considered sensitive or vulnerable in some network environments. Write operations (e.g., edit-config) to these data nodes without proper protection can have a negative effect on network operations. These are the subtrees and data nodes and their sensitivity/vulnerability: /: The entire data tree defined by this module is sensitive to write operations. For instance, the addition or removal of any trust anchor may dramatically alter the implemented security policy. For this reason, the NACM extension "default-deny- write" has been set for the entire data tree. None of the readable data nodes in this YANG module are considered sensitive or vulnerable in network environments. This module does not define any RPCs, actions, or notifications, and thus the security consideration for such is not provided here. 5. IANA Considerations 5.1. The IETF XML Registry This document registers one URI in the "ns" subregistry of the IETF XML Registry [RFC3688]. Following the format in [RFC3688], the following registration is requested: URI: urn:ietf:params:xml:ns:yang:ietf-truststore Registrant Contact: The NETCONF WG of the IETF. XML: N/A, the requested URI is an XML namespace. 5.2. The YANG Module Names Registry This document registers one YANG module in the YANG Module Names registry [RFC6020]. Following the format in [RFC6020], the the following registration is requested: name: ietf-truststore namespace: urn:ietf:params:xml:ns:yang:ietf-truststore prefix: ta reference: RFC XXXX Watsen Expires September 9, 2020 [Page 25] Internet-Draft A YANG Data Model for a Truststore March 2020 6. References 6.1. Normative References [I-D.ietf-netconf-crypto-types] Watsen, K. and H. Wang, "Common YANG Data Types for Cryptography", draft-ietf-netconf-crypto-types-13 (work in progress), November 2019. [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997, . [RFC7950] Bjorklund, M., Ed., "The YANG 1.1 Data Modeling Language", RFC 7950, DOI 10.17487/RFC7950, August 2016, . [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, May 2017, . [RFC8341] Bierman, A. and M. Bjorklund, "Network Configuration Access Control Model", STD 91, RFC 8341, DOI 10.17487/RFC8341, March 2018, . 6.2. Informative References [RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688, DOI 10.17487/RFC3688, January 2004, . [RFC6020] Bjorklund, M., Ed., "YANG - A Data Modeling Language for the Network Configuration Protocol (NETCONF)", RFC 6020, DOI 10.17487/RFC6020, October 2010, . [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, . [RFC8040] Bierman, A., Bjorklund, M., and K. Watsen, "RESTCONF Protocol", RFC 8040, DOI 10.17487/RFC8040, January 2017, . Watsen Expires September 9, 2020 [Page 26] Internet-Draft A YANG Data Model for a Truststore March 2020 [RFC8340] Bjorklund, M. and L. Berger, Ed., "YANG Tree Diagrams", BCP 215, RFC 8340, DOI 10.17487/RFC8340, March 2018, . [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, . [RFC8572] Watsen, K., Farrer, I., and M. Abrahamsson, "Secure Zero Touch Provisioning (SZTP)", RFC 8572, DOI 10.17487/RFC8572, April 2019, . Watsen Expires September 9, 2020 [Page 27] Internet-Draft A YANG Data Model for a Truststore March 2020 Appendix A. Change Log A.1. 00 to 01 o Added features "x509-certificates" and "ssh-host-keys". o Added nacm:default-deny-write to "trust-anchors" container. A.2. 01 to 02 o Switched "list pinned-certificate" to use the "trust-anchor-cert- grouping" from crypto-types. Effectively the same definition as before. A.3. 02 to 03 o Updated copyright date, boilerplate template, affiliation, folding algorithm, and reformatted the YANG module. A.4. 03 to 04 o Added groupings 'local-or-truststore-certs-grouping' and 'local- or-truststore-host-keys-grouping', matching similar definitions in the keystore draft. Note new (and incomplete) "truststore" usage! o Related to above, also added features 'truststore-supported' and 'local-trust-anchors-supported'. A.5. 04 to 05 o Renamed "trust-anchors" to "truststore" o Removed "pinned." prefix everywhere, to match truststore rename o Moved everything under a top-level 'grouping' to enable use in other contexts. o Renamed feature from 'local-trust-anchors-supported' to 'local- definitions-supported' (same name used in keystore) o Removed the "require-instance false" statement from the "*-ref" typedefs. o Added missing "ssh-host-keys" and "x509-certificates" if-feature statements Watsen Expires September 9, 2020 [Page 28] Internet-Draft A YANG Data Model for a Truststore March 2020 A.6. 05 to 06 o Editorial changes only. A.7. 06 to 07 o Added Henk Birkholz as a co-author (thanks Henk!) o Added PSKs and raw public keys to Truststore. A.8. 07 to 08 o Added new "Support for Built-in Trust Anchors" section. o Removed spurious "uses ct:trust-anchor-certs-grouping" line. o Removed PSK from model. A.9. 08 to 09 o Removed remaining PSK references from text. o Wrapped each top-level list with a container. o Introduced "bag" term. o Merged "SSH Public Keys" and "Raw Public Keys" in a single "Public Keys" bag. Consuming downstream modules (i.e., "ietf-[ssh/tls]- [client/server]) refinei the "public-key-format" to be either SSH or TLS specific as needed. Acknowledgements The authors especially thank Henk Birkholz for contributing YANG to the ietf-truststore module supporting raw public keys and PSKs (pre- shared or pairwise-symmetric keys). While these contributions were eventually replaced by reusing the existing support for asymmetric and symmetric trust anchors, respectively, it was only thru Henk's initiative that the WG was able to come to that result. The authors additionally thank the following for helping give shape to this work (ordered by last name): Martin Bjorklund, Nick Hancock, Balazs Kovacs, Eric Voit, and Liang Xia. Watsen Expires September 9, 2020 [Page 29] Internet-Draft A YANG Data Model for a Truststore March 2020 Author's Address Kent Watsen Watsen Networks EMail: kent+ietf@watsen.net Watsen Expires September 9, 2020 [Page 30]