NETCONF Working Group K. Watsen Internet-Draft Watsen Networks Intended status: Standards Track 10 July 2020 Expires: 11 January 2021 YANG Data Types and Groupings for Cryptography draft-ietf-netconf-crypto-types-17 Abstract This document presents a YANG 1.1 (RFC 7950) module defining identities, typedefs, and groupings useful to cryptographic applications. 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 this draft Artwork in this document contains placeholder values for the date of publication of this draft. Please apply the following replacement: * "2020-07-10" --> the publication date of this draft 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/. Watsen Expires 11 January 2021 [Page 1] Internet-DrafYANG Data Types and Groupings for Cryptography July 2020 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 11 January 2021. 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. Relation to other RFCs . . . . . . . . . . . . . . . . . 3 1.2. Specification Language . . . . . . . . . . . . . . . . . 5 1.3. Adherence to the NMDA . . . . . . . . . . . . . . . . . . 5 2. The "ietf-crypto-types" Module . . . . . . . . . . . . . . . 5 2.1. Data Model Overview . . . . . . . . . . . . . . . . . . . 5 2.2. Example Usage . . . . . . . . . . . . . . . . . . . . . . 16 2.3. YANG Module . . . . . . . . . . . . . . . . . . . . . . . 23 3. Security Considerations . . . . . . . . . . . . . . . . . . . 40 3.1. No Support for CRMF . . . . . . . . . . . . . . . . . . . 41 3.2. No Support for Key Generation . . . . . . . . . . . . . . 41 3.3. Strength of Keys Configured . . . . . . . . . . . . . . . 41 3.4. Deletion of Cleartext Key Values . . . . . . . . . . . . 41 3.5. The "ietf-crypto-types" YANG Module . . . . . . . . . . . 41 4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 43 4.1. The "IETF XML" Registry . . . . . . . . . . . . . . . . . 43 4.2. The "YANG Module Names" Registry . . . . . . . . . . . . 43 5. References . . . . . . . . . . . . . . . . . . . . . . . . . 43 5.1. Normative References . . . . . . . . . . . . . . . . . . 43 5.2. Informative References . . . . . . . . . . . . . . . . . 45 Appendix A. Change Log . . . . . . . . . . . . . . . . . . . . . 47 A.1. I-D to 00 . . . . . . . . . . . . . . . . . . . . . . . . 47 A.2. 00 to 01 . . . . . . . . . . . . . . . . . . . . . . . . 47 A.3. 01 to 02 . . . . . . . . . . . . . . . . . . . . . . . . 48 A.4. 02 to 03 . . . . . . . . . . . . . . . . . . . . . . . . 48 Watsen Expires 11 January 2021 [Page 2] Internet-DrafYANG Data Types and Groupings for Cryptography July 2020 A.5. 03 to 04 . . . . . . . . . . . . . . . . . . . . . . . . 49 A.6. 04 to 05 . . . . . . . . . . . . . . . . . . . . . . . . 49 A.7. 05 to 06 . . . . . . . . . . . . . . . . . . . . . . . . 49 A.8. 06 to 07 . . . . . . . . . . . . . . . . . . . . . . . . 50 A.9. 07 to 08 . . . . . . . . . . . . . . . . . . . . . . . . 50 A.10. 08 to 09 . . . . . . . . . . . . . . . . . . . . . . . . 50 A.11. 09 to 10 . . . . . . . . . . . . . . . . . . . . . . . . 50 A.12. 10 to 11 . . . . . . . . . . . . . . . . . . . . . . . . 51 A.13. 11 to 12 . . . . . . . . . . . . . . . . . . . . . . . . 51 A.14. 12 to 13 . . . . . . . . . . . . . . . . . . . . . . . . 51 A.15. 13 to 14 . . . . . . . . . . . . . . . . . . . . . . . . 51 A.16. 14 to 15 . . . . . . . . . . . . . . . . . . . . . . . . 52 A.17. 15 to 16 . . . . . . . . . . . . . . . . . . . . . . . . 52 A.18. 16 to 17 . . . . . . . . . . . . . . . . . . . . . . . . 52 Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . 53 Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 53 1. Introduction This document presents a YANG 1.1 [RFC7950] module defining identities, typedefs, and groupings useful to cryptographic applications. 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 define configuration modules for 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 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. Links the each RFC are provided below the diagram. Watsen Expires 11 January 2021 [Page 3] Internet-DrafYANG Data Types and Groupings for Cryptography July 2020 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 11 January 2021 [Page 4] Internet-DrafYANG Data Types and Groupings for Cryptography July 2020 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 in compliant with the Network Management Datastore Architecture (NMDA) [RFC8342]. It does not define any protocol accessible nodes that are "config false". 2. The "ietf-crypto-types" Module This section defines a YANG 1.1 [RFC7950] module that defines data types (typedefs and identities) and groupings supporting downstream models needing cryptographic primitives. 2.1. Data Model Overview 2.1.1. Features The following diagram lists all the "feature" statements defined in the "ietf-crypt-types" module: Features: +-- one-symmetric-key-format +-- one-asymmetric-key-format +-- encrypted-one-symmetric-key-format +-- encrypted-one-asymmetric-key-format +-- certificate-signing-request-generation 2.1.2. Identities The following diagram illustrates the relationship amongst the "identity" statements defined in the "ietf-crypto-types" module: Watsen Expires 11 January 2021 [Page 5] Internet-DrafYANG Data Types and Groupings for Cryptography July 2020 Identities: +-- public-key-format | +-- subject-public-key-info-format | +-- ssh-public-key-format +-- private-key-format | +-- rsa-private-key-format | +-- ec-private-key-format | +-- one-asymmetric-key-format | | {one-asymmetric-key-format}? | +-- encrypted-one-asymmetric-key-format | {encrypted-one-asymmetric-key-format}? +-- symmetric-key-format +-- octet-string-key-format +-- one-symmetric-key-format | {one-symmetric-key-format}? +-- encrypted-one-symmetric-key-format {encrypted-one-symmetric-key-format}? Comments: * The diagram shows that there are three base identities. These identities are used by this module to define the format that key data is encoded in. The base identities are "abstract", in the object orientied programming sense, in that they only define a "class" of formats, rather than a specific format. * The various derived identities define specific key encoding formats. The derived identities defined in this document are sufficient for the effort described in Section 1.1 but, by nature of them being identities, additional derived identities MAY be defined by future efforts. * Identities use to specify uncommon formats are enabled by "feature" statements, enabling applications to support them when needed. 2.1.3. Typedefs The following diagram illustrates the relationship amongst the "typedef" statements defined in the "ietf-crypto-types" module: Watsen Expires 11 January 2021 [Page 6] Internet-DrafYANG Data Types and Groupings for Cryptography July 2020 Typedefs: binary +-- csr-info +-- csr +-- x509 | +-- trust-anchor-cert-x509 | +-- end-entity-cert-x509 +-- crl +-- ocsp-request +-- ocsp-response +-- cms +-- data-content-cms +-- signed-data-cms | +-- trust-anchor-cert-cms | +-- end-entity-cert-cms +-- enveloped-data-cms +-- digested-data-cms +-- encrypted-data-cms +-- authenticated-data-cms Comments: * All of the typedefs defined in the "ietf-crypto-types" module extend the "binary" type defined in [RFC7950]. * Additionally, all the typedefs define a type for encoding an ASN.1 [ITU.X680.2015] structure using DER [ITU.X690.2015]. * The "trust-anchor-*" and "end-entity-*" typedefs are syntactically identical to their base typedefs and only distiguish themselves by the expected nature of their content. These typedefs are defined to facilitate common modeling needs. 2.1.4. Groupings The following diagram lists all the "grouping" statements defined in the "ietf-crypto-types" module: Groupings: +-- encrypted-key-value-grouping +-- symmetric-key-grouping +-- public-key-grouping +-- asymmetric-key-pair-grouping +-- trust-anchor-cert-grouping +-- end-entity-cert-grouping +-- generate-csr-grouping +-- asymmetric-key-pair-with-cert-grouping +-- asymmetric-key-pair-with-certs-grouping Watsen Expires 11 January 2021 [Page 7] Internet-DrafYANG Data Types and Groupings for Cryptography July 2020 Each of these groupings are presented in the following subsections. 2.1.4.1. The "encrypted-key-value-grouping" Grouping The following tree diagram [RFC8340] illustrates the "encrypted-key- value-grouping" grouping: grouping encrypted-key-value-grouping +-- encrypted-by +-- encrypted-value binary Comments: * The "encrypted-by" node is an empty container (difficult to see in the diagram) that a consuming module MUST augment key references into. The "ietf-crypto-types" module is unable to populate this container as the module only defines groupings. Section 2.2.1 presents an example illustrating a consuming module populating the "encrypted-by" container. * The "encrypted-value" node is the key, encrypted by the other key referenced by the "encrypted-by" node, encoded in the format specified by the "format" identity Section 2.1.2 associated with the ancestor node using this grouping. 2.1.4.2. The "symmetric-key-grouping" Grouping This section presents two tree diagrams [RFC8340] illustrating the "symmetric-key-grouping" grouping. The first tree diagram does not expand the internally used grouping statement(s): grouping symmetric-key-grouping +-- key-format? identityref +-- (key-type) +--:(cleartext-key) | +-- cleartext-key? binary +--:(hidden-key) | +-- hidden-key? empty +--:(encrypted-key) +-- encrypted-key +---u encrypted-key-value-grouping The following tree diagram expands the internally used grouping statement(s), enabling the grouping's full structure to be seen: Watsen Expires 11 January 2021 [Page 8] Internet-DrafYANG Data Types and Groupings for Cryptography July 2020 grouping symmetric-key-grouping +-- key-format? identityref +-- (key-type) +--:(cleartext-key) | +-- cleartext-key? binary +--:(hidden-key) | +-- hidden-key? empty +--:(encrypted-key) +-- encrypted-key +-- encrypted-by +-- encrypted-value binary Comments: * For the referenced grouping statement(s): - The "encrypted-key-value-grouping" grouping is discussed in Section 2.1.4.1. * The "key-format" node is an identity-reference to the "symmetric- key-format" abstract base identity discussed in Section 2.1.2, enabling the symmetric key to be encoded using the format defined by any of the derived identities. * The "choice" statement enables the private key data to be plain- text, encrypted, or hidden, as follows: - The "key" node can encode any plain-text key value. - The "hidden-key" node is of type "empty" as the real value cannot be presented via the management interface. - The "encrypted-key" node's structure is discussed in Section 2.1.4.1. 2.1.4.3. The "public-key-grouping" Grouping The following tree diagram [RFC8340] illustrates the "public-key- grouping" grouping: grouping public-key-grouping +-- public-key-format identityref +-- public-key binary Comments: * The "public-key-format" node is an identity-reference to the "public-key-format" abstract base identity discussed in Section 2.1.2, enabling the public key to be encoded using the format defined by any of the derived identities. Watsen Expires 11 January 2021 [Page 9] Internet-DrafYANG Data Types and Groupings for Cryptography July 2020 * The "public-key" node is the public key data in the selected format. No "choice" statement is used to hide or encrypt the public key data because it is unecessary to do so for public keys. 2.1.4.4. The "asymmetric-key-pair-grouping" Grouping This section presents two tree diagrams [RFC8340] illustrating the "asymmetric-key-pair-grouping" grouping. The first tree diagram does not expand the internally used grouping statement(s): grouping asymmetric-key-pair-grouping +---u public-key-grouping +-- private-key-format? identityref +-- (private-key-type) +--:(cleartext-private-key) | +-- cleartext-private-key? binary +--:(hidden-private-key) | +-- hidden-private-key? empty +--:(encrypted-private-key) +-- encrypted-private-key +---u encrypted-key-value-grouping The following tree diagram expands the internally used grouping statement(s), enabling the grouping's full structure to be seen: grouping asymmetric-key-pair-grouping +-- public-key-format identityref +-- public-key binary +-- private-key-format? identityref +-- (private-key-type) +--:(cleartext-private-key) | +-- cleartext-private-key? binary +--:(hidden-private-key) | +-- hidden-private-key? empty +--:(encrypted-private-key) +-- encrypted-private-key +-- encrypted-by +-- encrypted-value binary Comments: * For the referenced grouping statement(s): - The "public-key-grouping" grouping is discussed in Section 2.1.4.3. - The "encrypted-key-value-grouping" grouping is discussed in Section 2.1.4.1. Watsen Expires 11 January 2021 [Page 10] Internet-DrafYANG Data Types and Groupings for Cryptography July 2020 * The "private-key-format" node is an identity-reference to the "private-key-format" abstract base identity discussed in Section 2.1.2, enabling the private key to be encoded using the format defined by any of the derived identities. * The "choice" statement enables the private key data to be plain- text, encrypted, or hidden, as follows: - The "private-key" node can encode any plain-text key value. - The "hidden-private-key" node is of type "empty" as the real value cannot be presented via the management interface. - The "encrypted-private-key" node's structure is discussed in Section 2.1.4.1. 2.1.4.5. The "certificate-expiration-grouping" Grouping The following tree diagram [RFC8340] illustrates the "certificate- expiration-grouping" grouping: grouping certificate-expiration-grouping +---n certificate-expiration +-- expiration-date yang:date-and-time Comments: * This grouping's only purpose is to define the "certificate- expiration" notification statement, used by the groupings defined in Section 2.1.4.6 and Section 2.1.4.7. * The "certificate-expiration" notification enables servers to notify clients when certificates are nearing expiration. * The "expiration-date" node indicates when the designated certificate will (or did) expire. * Identification of the certificate that is expiring is built into the notification itself. For an example, please see Section 2.2.3. 2.1.4.6. The "trust-anchor-cert-grouping" Grouping This section presents two tree diagrams [RFC8340] illustrating the "trust-anchor-cert-grouping" grouping. The first tree diagram does not expand the internally used grouping statement(s): grouping trust-anchor-cert-grouping +-- cert-data? trust-anchor-cert-cms +---u certificate-expiration-grouping Watsen Expires 11 January 2021 [Page 11] Internet-DrafYANG Data Types and Groupings for Cryptography July 2020 The following tree diagram expands the internally used grouping statement(s), enabling the grouping's full structure to be seen: grouping trust-anchor-cert-grouping +-- cert-data? trust-anchor-cert-cms +---n certificate-expiration +-- expiration-date yang:date-and-time Comments: * For the referenced grouping statement(s): - The "certificate-expiration-grouping" grouping is discussed in Section 2.1.4.5. * The "cert-data" node contains a chain of one or more certificates encoded using a "signed-data-cms" typedef discussed in Section 2.1.3. 2.1.4.7. The "end-entity-cert-grouping" Grouping This section presents two tree diagrams [RFC8340] illustrating the "end-entity-cert-grouping" grouping. The first tree diagram does not expand the internally used grouping statement(s): grouping end-entity-cert-grouping +-- cert-data? end-entity-cert-cms +---u certificate-expiration-grouping The following tree diagram expands the internally used grouping statement(s), enabling the grouping's full structure to be seen: grouping end-entity-cert-grouping +-- cert-data? end-entity-cert-cms +---n certificate-expiration +-- expiration-date yang:date-and-time Comments: * For the referenced grouping statement(s): - The "certificate-expiration-grouping" grouping is discussed in Section 2.1.4.5. * The "cert-data" node contains a chain of one or more certificates encoded using a "signed-data-cms" typedef discussed in Section 2.1.3. Watsen Expires 11 January 2021 [Page 12] Internet-DrafYANG Data Types and Groupings for Cryptography July 2020 2.1.4.8. The "generate-csr-grouping" Grouping The following tree diagram [RFC8340] illustrates the "generate-csr- grouping" grouping: grouping generate-csr-grouping +---x generate-certificate-signing-request {certificate-signing-request-generation}? +---w input | +---w csr-info ct:csr-info +--ro output +--ro certificate-signing-request ct:csr Comments: * This grouping's only purpose is to define the "generate- certificate-signing-request" action statement, used by the groupings defined in Section 2.1.4.9 and Section 2.1.4.10. * This action takes as input a "csr-info" type and returns a "csr" type, both of which are discussed in Section 2.1.3. * For an example, please see Section 2.2.2. 2.1.4.9. The "asymmetric-key-pair-with-cert-grouping" Grouping This section presents two tree diagrams [RFC8340] illustrating the "asymmetric-key-pair-with-cert-grouping" grouping. The first tree diagram does not expand the internally used grouping statement(s): grouping asymmetric-key-pair-with-cert-grouping +---u asymmetric-key-pair-grouping +---u end-entity-cert-grouping +---u generate-csr-grouping The following tree diagram expands the internally used grouping statement(s), enabling the grouping's full structure to be seen: Watsen Expires 11 January 2021 [Page 13] Internet-DrafYANG Data Types and Groupings for Cryptography July 2020 grouping asymmetric-key-pair-with-cert-grouping +-- public-key-format identityref +-- public-key binary +-- private-key-format? identityref +-- (private-key-type) | +--:(cleartext-private-key) | | +-- cleartext-private-key? binary | +--:(hidden-private-key) | | +-- hidden-private-key? empty | +--:(encrypted-private-key) | +-- encrypted-private-key | +-- encrypted-by | +-- encrypted-value binary +-- cert-data? end-entity-cert-cms +---n certificate-expiration | +-- expiration-date yang:date-and-time +---x generate-certificate-signing-request {certificate-signing-request-generation}? +---w input | +---w csr-info ct:csr-info +--ro output +--ro certificate-signing-request ct:csr Comments: * This grouping defines an asymmetric key with at most one associated certificate, a commonly needed combination in protocol models. * For the referenced grouping statement(s): - The "asymmetric-key-pair-grouping" grouping is discussed in Section 2.1.4.4. - The "end-entity-cert-grouping" grouping is discussed in Section 2.1.4.7. - The "generate-csr-grouping" grouping is discussed in Section 2.1.4.8. 2.1.4.10. The "asymmetric-key-pair-with-certs-grouping" Grouping This section presents two tree diagrams [RFC8340] illustrating the "asymmetric-key-pair-with-certs-grouping" grouping. The first tree diagram does not expand the internally used grouping statement(s): Watsen Expires 11 January 2021 [Page 14] Internet-DrafYANG Data Types and Groupings for Cryptography July 2020 grouping asymmetric-key-pair-with-certs-grouping +---u asymmetric-key-pair-grouping +-- certificates | +-- certificate* [name] | +-- name? string | +---u end-entity-cert-grouping +---u generate-csr-grouping The following tree diagram expands the internally used grouping statement(s), enabling the grouping's full structure to be seen: grouping asymmetric-key-pair-with-certs-grouping +-- public-key-format identityref +-- public-key binary +-- private-key-format? identityref +-- (private-key-type) | +--:(cleartext-private-key) | | +-- cleartext-private-key? binary | +--:(hidden-private-key) | | +-- hidden-private-key? empty | +--:(encrypted-private-key) | +-- encrypted-private-key | +-- encrypted-by | +-- encrypted-value binary +-- certificates | +-- certificate* [name] | +-- name? string | +-- cert-data end-entity-cert-cms | +---n certificate-expiration | +-- expiration-date yang:date-and-time +---x generate-certificate-signing-request {certificate-signing-request-generation}? +---w input | +---w csr-info ct:csr-info +--ro output +--ro certificate-signing-request ct:csr Comments: * This grouping defines an asymmetric key with one or more associated certificates, a commonly needed combination in configuration models. * For the referenced grouping statement(s): - The "asymmetric-key-pair-grouping" grouping is discussed in Section 2.1.4.4. Watsen Expires 11 January 2021 [Page 15] Internet-DrafYANG Data Types and Groupings for Cryptography July 2020 - The "end-entity-cert-grouping" grouping is discussed in Section 2.1.4.7. - The "generate-csr-grouping" grouping is discussed in Section 2.1.4.8. 2.1.5. Protocol-accessible Nodes The "ietf-crypto-types" module does not contain any protocol- accessible nodes, but the module needs to be "implemented", as described in Section 5.6.5 of [RFC7950], in order for the identities in Section 2.1.2 to be defined. 2.2. Example Usage 2.2.1. The "symmetric-key-grouping" and "asymmetric-key-pair-with- certs-grouping" Grouping The following non-normative module is constructed in order to illustrate the use of the "symmetric-key-grouping" (Section 2.1.4.2) and the "asymmetric-key-pair-with-certs-grouping" (Section 2.1.4.10) grouping statements: module ex-crypto-types-usage { yang-version 1.1; namespace "http://example.com/ns/example-crypto-types-usage"; prefix "ectu"; import ietf-crypto-types { prefix ct; reference "RFC AAAA: YANG Data Types and Groupings for Cryptography"; } organization "Example Corporation"; contact "YANG Designer "; description "This module illustrates the 'symmetric-key-grouping' and 'asymmetric-key-grouping' groupings defined in the 'ietf-crypto-types' module defined in RFC AAAA."; revision "2020-07-10" { description "Initial version"; reference "RFC AAAA: Common YANG Data Types for Cryptography"; } Watsen Expires 11 January 2021 [Page 16] Internet-DrafYANG Data Types and Groupings for Cryptography July 2020 container symmetric-keys { description "A container of symmetric keys."; list symmetric-key { key name; description "A symmetric key"; leaf name { type string; description "An arbitrary name for this key."; } uses ct:symmetric-key-grouping { augment "key-type/encrypted-key/encrypted-key/" + "encrypted-by" { description "Augments in a choice statement enabling the encrypting key to be any other symmetric or asymmetric key."; uses encrypted-by-choice-grouping; } } } } container asymmetric-keys { description "A container of asymmetric keys."; list asymmetric-key { key name; leaf name { type string; description "An arbitrary name for this key."; } uses ct:asymmetric-key-pair-with-certs-grouping { augment "private-key-type/encrypted-private-key/" + "encrypted-private-key/encrypted-by" { description "Augments in a choice statement enabling the encrypting key to be any other symmetric or asymmetric key."; uses encrypted-by-choice-grouping; } } description "An asymmetric key pair with associated certificates."; } Watsen Expires 11 January 2021 [Page 17] Internet-DrafYANG Data Types and Groupings for Cryptography July 2020 } grouping encrypted-by-choice-grouping { description "A grouping that defines a choice enabling references to other keys."; choice encrypted-by-choice { mandatory true; description "A choice amongst other symmetric or asymmetric keys."; case symmetric-key-ref { leaf symmetric-key-ref { type leafref { path "/ectu:symmetric-keys/ectu:symmetric-key/" + "ectu:name"; } description "Identifies the symmetric key used to encrypt this key."; } } case asymmetric-key-ref { leaf asymmetric-key-ref { type leafref { path "/ectu:asymmetric-keys/ectu:asymmetric-key/" + "ectu:name"; } description "Identifies the asymmetric key used to encrypt this key."; } } } } } The tree diagram [RFC8340] for this example module follows: module: ex-crypto-types-usage +--rw symmetric-keys | +--rw symmetric-key* [name] | +--rw name string | +--rw key-format? identityref | +--rw (key-type) | +--:(cleartext-key) | | +--rw cleartext-key? binary | +--:(hidden-key) | | +--rw hidden-key? empty | +--:(encrypted-key) | +--rw encrypted-key Watsen Expires 11 January 2021 [Page 18] Internet-DrafYANG Data Types and Groupings for Cryptography July 2020 | +--rw encrypted-by | | +--rw (encrypted-by-choice) | | +--:(symmetric-key-ref) | | | +--rw symmetric-key-ref? leafref | | +--:(asymmetric-key-ref) | | +--rw asymmetric-key-ref? leafref | +--rw encrypted-value binary +--rw asymmetric-keys +--rw asymmetric-key* [name] +--rw name string +--rw public-key-format identityref +--rw public-key binary +--rw private-key-format? identityref +--rw (private-key-type) | +--:(cleartext-private-key) | | +--rw cleartext-private-key? binary | +--:(hidden-private-key) | | +--rw hidden-private-key? empty | +--:(encrypted-private-key) | +--rw encrypted-private-key | +--rw encrypted-by | | +--rw (encrypted-by-choice) | | +--:(symmetric-key-ref) | | | +--rw symmetric-key-ref? leafref | | +--:(asymmetric-key-ref) | | +--rw asymmetric-key-ref? leafref | +--rw encrypted-value binary +--rw certificates | +--rw certificate* [name] | +--rw name string | +--rw cert-data end-entity-cert-cms | +---n certificate-expiration | +-- expiration-date yang:date-and-time +---x generate-certificate-signing-request {certificate-signing-request-generation}? +---w input | +---w csr-info ct:csr-info +--ro output +--ro certificate-signing-request ct:csr grouping encrypted-by-choice-grouping +-- (encrypted-by-choice) +--:(symmetric-key-ref) | +-- symmetric-key-ref? | -> /symmetric-keys/symmetric-key/name +--:(asymmetric-key-ref) +-- asymmetric-key-ref? -> /asymmetric-keys/asymmetric-key/name Watsen Expires 11 January 2021 [Page 19] Internet-DrafYANG Data Types and Groupings for Cryptography July 2020 Finally, the following example illustrates various symmetric and asymmetric keys as they might appear in confugration: =============== NOTE: '\' line wrapping per RFC 8792 ================ ex-hidden-symmetric-key ex-octet-string-based-symmetric-key ct:octet-string-key-format base64encodedvalue== ex-one-symmetric-based-symmetric-key ct:one-symmetric-key-format base64encodedvalue== ex-encrypted-one-symmetric-based-symmetric-key ct:encrypted-one-symmetric-key-format ex-hidden-asymmetric-key base64encodedvalue== ex-hidden-asymmetric-key ct:subject-public-key-info-format base64encodedvalue== ex-hidden-asymmetric-key-cert Watsen Expires 11 January 2021 [Page 20] Internet-DrafYANG Data Types and Groupings for Cryptography July 2020 base64encodedvalue== ex-subject-public-info-based-asymmetric-key ct:subject-public-key-info-format base64encodedvalue== ct:rsa-private-key-format base64encodedvalue== ex-cert base64encodedvalue== ex-one-asymmetric-based-symmetric-key ct:subject-public-key-info-format base64encodedvalue== ct:one-asymmetric-key-format base64encodedvalue== ex-encrypted-one-asymmetric-based-symmetric-key ct:subject-public-key-info-format base64encodedvalue== ct:encrypted-one-asymmetric-key-format ex-encrypted-one-symmetric-based-symmetri\ c-key Watsen Expires 11 January 2021 [Page 21] Internet-DrafYANG Data Types and Groupings for Cryptography July 2020 base64encodedvalue== 2.2.2. The "generate-certificate-signing-request" Action The following example illustrates the "generate-certificate-signing- request" action, discussed in Section 2.1.4.8, with the NETCONF protocol. REQUEST ex-key-sect571r1 base64encodedvalue== RESPONSE base64encodedvalue== 2.2.3. The "certificate-expiration" Notification The following example illustrates the "certificate-expiration" notification, discussed in Section 2.1.4.5, with the NETCONF protocol. Watsen Expires 11 January 2021 [Page 22] Internet-DrafYANG Data Types and Groupings for Cryptography July 2020 =============== NOTE: '\' line wrapping per RFC 8792 ================ 2018-05-25T00:01:00Z ex-hidden-asymmetric-key ex-hidden-asymmetric-key 2018-08-05T14:18:53-05:00 2.3. YANG Module This module has normative references to [RFC2119], [RFC2986], [RFC3447], [RFC4253], [RFC5280], [RFC5652], [RFC5915], [RFC5958], [RFC6031], [RFC6125], [RFC6991], [RFC8174], [RFC8341], and [ITU.X690.2015]. file "ietf-crypto-types@2020-07-10.yang" module ietf-crypto-types { yang-version 1.1; namespace "urn:ietf:params:xml:ns:yang:ietf-crypto-types"; prefix ct; import ietf-yang-types { prefix yang; reference "RFC 6991: Common YANG Data Types"; } import ietf-netconf-acm { prefix nacm; reference "RFC 8341: Network Configuration Access Control Model"; } Watsen Expires 11 January 2021 [Page 23] Internet-DrafYANG Data Types and Groupings for Cryptography July 2020 organization "IETF NETCONF (Network Configuration) Working Group"; contact "WG Web: WG List: Author: Kent Watsen "; description "This module defines common YANG types for cryptographic applications. 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 AAAA (https://www.rfc-editor.org/info/rfcAAAA); 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 2020-07-10 { description "Initial version"; reference "RFC AAAA: YANG Data Types and Groupings for Cryptography"; } /****************/ /* Features */ /****************/ feature one-symmetric-key-format { description "Indicates that the server supports the Watsen Expires 11 January 2021 [Page 24] Internet-DrafYANG Data Types and Groupings for Cryptography July 2020 'one-symmetric-key-format' identity."; } feature one-asymmetric-key-format { description "Indicates that the server supports the 'one-asymmetric-key-format' identity."; } feature encrypted-one-symmetric-key-format { description "Indicates that the server supports the 'encrypted-one-symmetric-key-format' identity."; } feature encrypted-one-asymmetric-key-format { description "Indicates that the server supports the 'encrypted-one-asymmetric-key-format' identity."; } feature certificate-signing-request-generation { description "Indicates that the server implements the 'generate-certificate-signing-request' action."; } /*************************************************/ /* Base Identities for Key Format Structures */ /*************************************************/ identity symmetric-key-format { description "Base key-format identity for symmetric keys."; } identity public-key-format { description "Base key-format identity for public keys."; } identity private-key-format { description "Base key-format identity for private keys."; } /****************************************************/ /* Identities for Private Key Format Structures */ /****************************************************/ Watsen Expires 11 January 2021 [Page 25] Internet-DrafYANG Data Types and Groupings for Cryptography July 2020 identity rsa-private-key-format { base "private-key-format"; description "Indicates that the private key value is encoded as an RSAPrivateKey (from RFC 3447)."; reference "RFC 3447: PKCS #1: RSA Cryptography Specifications Version 2.2"; } identity ec-private-key-format { base "private-key-format"; description "Indicates that the private key value is encoded as an ECPrivateKey (from RFC 5915)"; reference "RFC 5915: Elliptic Curve Private Key Structure"; } identity one-asymmetric-key-format { if-feature "one-asymmetric-key-format"; base "private-key-format"; description "Indicates that the private key value is a CMS OneAsymmetricKey structure, as defined in RFC 5958, encoded using ASN.1 distinguished encoding rules (DER), as specified in ITU-T X.690."; reference "RFC 5958: Asymmetric Key Packages ITU-T X.690: Information technology - ASN.1 encoding rules: Specification of Basic Encoding Rules (BER), Canonical Encoding Rules (CER) and Distinguished Encoding Rules (DER)."; } identity encrypted-one-asymmetric-key-format { if-feature "encrypted-one-asymmetric-key-format"; base "private-key-format"; description "Indicates that the private key value is a CMS EnvelopedData structure, per Section 8 in RFC 5652, containing a OneAsymmetricKey structure, as defined in RFC 5958, encoded using ASN.1 distinguished encoding rules (DER), as specified in ITU-T X.690."; reference "RFC 5652: Cryptographic Message Syntax (CMS) RFC 5958: Asymmetric Key Packages Watsen Expires 11 January 2021 [Page 26] Internet-DrafYANG Data Types and Groupings for Cryptography July 2020 ITU-T X.690: Information technology - ASN.1 encoding rules: Specification of Basic Encoding Rules (BER), Canonical Encoding Rules (CER) and Distinguished Encoding Rules (DER)."; } /***************************************************/ /* Identities for Public Key Format Structures */ /***************************************************/ identity ssh-public-key-format { base "public-key-format"; description "Indicates that the public key value is an SSH public key, as specified by RFC 4253, Section 6.6, i.e.: string certificate or public key format identifier byte[n] key/certificate data."; reference "RFC 4253: The Secure Shell (SSH) Transport Layer Protocol"; } identity subject-public-key-info-format { base "public-key-format"; description "Indicates that the public key value is a SubjectPublicKeyInfo structure, as described in RFC 5280 encoded using ASN.1 distinguished encoding rules (DER), as specified in ITU-T X.690."; reference "RFC 5280: Internet X.509 Public Key Infrastructure Certificate and Certificate Revocation List (CRL) Profile ITU-T X.690: Information technology - ASN.1 encoding rules: Specification of Basic Encoding Rules (BER), Canonical Encoding Rules (CER) and Distinguished Encoding Rules (DER)."; } /******************************************************/ /* Identities for Symmetric Key Format Structures */ /******************************************************/ Watsen Expires 11 January 2021 [Page 27] Internet-DrafYANG Data Types and Groupings for Cryptography July 2020 identity octet-string-key-format { base "symmetric-key-format"; description "Indicates that the key is encoded as a raw octet string. The length of the octet string MUST be appropriate for the associated algorithm's block size."; } identity one-symmetric-key-format { if-feature "one-symmetric-key-format"; base "symmetric-key-format"; description "Indicates that the private key value is a CMS OneSymmetricKey structure, as defined in RFC 6031, encoded using ASN.1 distinguished encoding rules (DER), as specified in ITU-T X.690."; reference "RFC 6031: Cryptographic Message Syntax (CMS) Symmetric Key Package Content Type ITU-T X.690: Information technology - ASN.1 encoding rules: Specification of Basic Encoding Rules (BER), Canonical Encoding Rules (CER) and Distinguished Encoding Rules (DER)."; } identity encrypted-one-symmetric-key-format { if-feature "encrypted-one-symmetric-key-format"; base "symmetric-key-format"; description "Indicates that the private key value is a CMS EnvelopedData structure, per Section 8 in RFC 5652, containing a OneSymmetricKey structure, as defined in RFC 6031, encoded using ASN.1 distinguished encoding rules (DER), as specified in ITU-T X.690."; reference "RFC 5652: Cryptographic Message Syntax (CMS) RFC 6031: Cryptographic Message Syntax (CMS) Symmetric Key Package Content Type ITU-T X.690: Information technology - ASN.1 encoding rules: Specification of Basic Encoding Rules (BER), Canonical Encoding Rules (CER) and Distinguished Encoding Rules (DER)."; } /***************************************************/ Watsen Expires 11 January 2021 [Page 28] Internet-DrafYANG Data Types and Groupings for Cryptography July 2020 /* Typedefs for ASN.1 structures from RFC 2986 */ /***************************************************/ typedef csr-info { type binary; description "A CertificationRequestInfo structure, as defined in RFC 2986, encoded using ASN.1 distinguished encoding rules (DER), as specified in ITU-T X.690."; reference "RFC 2986: PKCS #10: Certification Request Syntax Specification Version 1.7 ITU-T X.690: Information technology - ASN.1 encoding rules: Specification of Basic Encoding Rules (BER), Canonical Encoding Rules (CER) and Distinguished Encoding Rules (DER)."; } typedef csr { type binary; description "A CertificationRequest structure, as specified in RFC 2986, encoded using ASN.1 distinguished encoding rules (DER), as specified in ITU-T X.690."; reference "RFC 2986: PKCS #10: Certification Request Syntax Specification Version 1.7 ITU-T X.690: Information technology - ASN.1 encoding rules: Specification of Basic Encoding Rules (BER), Canonical Encoding Rules (CER) and Distinguished Encoding Rules (DER)."; } /***************************************************/ /* Typedefs for ASN.1 structures from RFC 5280 */ /***************************************************/ typedef x509 { type binary; description "A Certificate structure, as specified in RFC 5280, encoded using ASN.1 distinguished encoding rules (DER), as specified in ITU-T X.690."; reference "RFC 5280: Watsen Expires 11 January 2021 [Page 29] Internet-DrafYANG Data Types and Groupings for Cryptography July 2020 Internet X.509 Public Key Infrastructure Certificate and Certificate Revocation List (CRL) Profile ITU-T X.690: Information technology - ASN.1 encoding rules: Specification of Basic Encoding Rules (BER), Canonical Encoding Rules (CER) and Distinguished Encoding Rules (DER)."; } typedef crl { type binary; description "A CertificateList structure, as specified in RFC 5280, encoded using ASN.1 distinguished encoding rules (DER), as specified in ITU-T X.690."; reference "RFC 5280: Internet X.509 Public Key Infrastructure Certificate and Certificate Revocation List (CRL) Profile ITU-T X.690: Information technology - ASN.1 encoding rules: Specification of Basic Encoding Rules (BER), Canonical Encoding Rules (CER) and Distinguished Encoding Rules (DER)."; } /***************************************************/ /* Typedefs for ASN.1 structures from RFC 6960 */ /***************************************************/ typedef oscp-request { type binary; description "A OCSPRequest structure, as specified in RFC 6960, encoded using ASN.1 distinguished encoding rules (DER), as specified in ITU-T X.690."; reference "RFC 6960: X.509 Internet Public Key Infrastructure Online Certificate Status Protocol - OCSP ITU-T X.690: Information technology - ASN.1 encoding rules: Specification of Basic Encoding Rules (BER), Canonical Encoding Rules (CER) and Distinguished Encoding Rules (DER)."; } Watsen Expires 11 January 2021 [Page 30] Internet-DrafYANG Data Types and Groupings for Cryptography July 2020 typedef oscp-response { type binary; description "A OCSPResponse structure, as specified in RFC 6960, encoded using ASN.1 distinguished encoding rules (DER), as specified in ITU-T X.690."; reference "RFC 6960: X.509 Internet Public Key Infrastructure Online Certificate Status Protocol - OCSP ITU-T X.690: Information technology - ASN.1 encoding rules: Specification of Basic Encoding Rules (BER), Canonical Encoding Rules (CER) and Distinguished Encoding Rules (DER)."; } /***********************************************/ /* Typedefs for ASN.1 structures from 5652 */ /***********************************************/ typedef cms { type binary; description "A ContentInfo structure, as specified in RFC 5652, encoded using ASN.1 distinguished encoding rules (DER), as specified in ITU-T X.690."; reference "RFC 5652: Cryptographic Message Syntax (CMS) ITU-T X.690: Information technology - ASN.1 encoding rules: Specification of Basic Encoding Rules (BER), Canonical Encoding Rules (CER) and Distinguished Encoding Rules (DER)."; } typedef data-content-cms { type cms; description "A CMS structure whose top-most content type MUST be the data content type, as described by Section 4 in RFC 5652."; reference "RFC 5652: Cryptographic Message Syntax (CMS)"; } typedef signed-data-cms { Watsen Expires 11 January 2021 [Page 31] Internet-DrafYANG Data Types and Groupings for Cryptography July 2020 type cms; description "A CMS structure whose top-most content type MUST be the signed-data content type, as described by Section 5 in RFC 5652."; reference "RFC 5652: Cryptographic Message Syntax (CMS)"; } typedef enveloped-data-cms { type cms; description "A CMS structure whose top-most content type MUST be the enveloped-data content type, as described by Section 6 in RFC 5652."; reference "RFC 5652: Cryptographic Message Syntax (CMS)"; } typedef digested-data-cms { type cms; description "A CMS structure whose top-most content type MUST be the digested-data content type, as described by Section 7 in RFC 5652."; reference "RFC 5652: Cryptographic Message Syntax (CMS)"; } typedef encrypted-data-cms { type cms; description "A CMS structure whose top-most content type MUST be the encrypted-data content type, as described by Section 8 in RFC 5652."; reference "RFC 5652: Cryptographic Message Syntax (CMS)"; } typedef authenticated-data-cms { type cms; description "A CMS structure whose top-most content type MUST be the authenticated-data content type, as described by Section 9 in RFC 5652."; reference "RFC 5652: Cryptographic Message Syntax (CMS)"; } Watsen Expires 11 January 2021 [Page 32] Internet-DrafYANG Data Types and Groupings for Cryptography July 2020 /*********************************************************/ /* Typedefs for ASN.1 structures related to RFC 5280 */ /*********************************************************/ typedef trust-anchor-cert-x509 { type x509; description "A Certificate structure that MUST encode a self-signed root certificate."; } typedef end-entity-cert-x509 { type x509; description "A Certificate structure that MUST encode a certificate that is neither self-signed nor having Basic constraint CA true."; } /*********************************************************/ /* Typedefs for ASN.1 structures related to RFC 5652 */ /*********************************************************/ typedef trust-anchor-cert-cms { type signed-data-cms; description "A CMS SignedData structure that MUST contain the chain of X.509 certificates needed to authenticate the certificate presented by a client or end-entity. The CMS MUST contain only a single chain of certificates. The client or end-entity certificate MUST only authenticate to last intermediate CA certificate listed in the chain. In all cases, the chain MUST include a self-signed root certificate. In the case where the root certificate is itself the issuer of the client or end-entity certificate, only one certificate is present. This CMS structure MAY (as applicable where this type is used) also contain suitably fresh (as defined by local policy) revocation objects with which the device can verify the revocation status of the certificates. This CMS encodes the degenerate form of the SignedData structure that is commonly used to disseminate X.509 certificates and revocation objects (RFC 5280)."; Watsen Expires 11 January 2021 [Page 33] Internet-DrafYANG Data Types and Groupings for Cryptography July 2020 reference "RFC 5280: Internet X.509 Public Key Infrastructure Certificate and Certificate Revocation List (CRL) Profile."; } typedef end-entity-cert-cms { type signed-data-cms; description "A CMS SignedData structure that MUST contain the end entity certificate itself, and MAY contain any number of intermediate certificates leading up to a trust anchor certificate. The trust anchor certificate MAY be included as well. The CMS MUST contain a single end entity certificate. The CMS MUST NOT contain any spurious certificates. This CMS structure MAY (as applicable where this type is used) also contain suitably fresh (as defined by local policy) revocation objects with which the device can verify the revocation status of the certificates. This CMS encodes the degenerate form of the SignedData structure that is commonly used to disseminate X.509 certificates and revocation objects (RFC 5280)."; reference "RFC 5280: Internet X.509 Public Key Infrastructure Certificate and Certificate Revocation List (CRL) Profile."; } /**********************************************/ /* Groupings for keys and/or certificates */ /**********************************************/ grouping encrypted-key-value-grouping { description "A reusable grouping for a value that has been encrypted by a symmetric or asymmetric key in the Keystore."; container encrypted-by { nacm:default-deny-write; description "An empty container enabling references to other keys that encrypt these keys to be augmented in. The referenced key MAY be a symmetric or an asymmetric key."; } Watsen Expires 11 January 2021 [Page 34] Internet-DrafYANG Data Types and Groupings for Cryptography July 2020 leaf encrypted-value { nacm:default-deny-write; type binary; must "../encrypted-by"; mandatory true; description "The key data, encrypted using the referenced symmetric or asymmetric key. The format of the encrypted value is identicated by the associated key format identity."; } } grouping symmetric-key-grouping { description "A symmetric key."; leaf key-format { nacm:default-deny-write; type identityref { base symmetric-key-format; } description "Identifies the symmetric key's format."; } choice key-type { nacm:default-deny-write; mandatory true; description "Choice between key types."; case cleartext-key { leaf cleartext-key { nacm:default-deny-all; type binary; must "../key-format"; description "The binary value of the key. The interpretation of the value is defined by the 'key-format' field."; } } case hidden-key { leaf hidden-key { type empty; must "not(../key-format)"; description "A hidden key. How such keys are created is outside the scope of this module."; } } case encrypted-key { container encrypted-key { Watsen Expires 11 January 2021 [Page 35] Internet-DrafYANG Data Types and Groupings for Cryptography July 2020 must "../key-format"; description "A container for the encrypted symmetric key value."; uses encrypted-key-value-grouping; } } } } grouping public-key-grouping { description "A public key."; leaf public-key-format { nacm:default-deny-write; type identityref { base public-key-format; } mandatory true; description "Identifies the key's format."; } leaf public-key { nacm:default-deny-write; type binary; mandatory true; description "The binary value of the public key. The interpretation of the value is defined by 'public-key-format' field."; } } grouping asymmetric-key-pair-grouping { description "A private key and its associated public key."; uses public-key-grouping; leaf private-key-format { nacm:default-deny-write; type identityref { base private-key-format; } description "Identifies the key's format."; } choice private-key-type { nacm:default-deny-write; mandatory true; description "Choice between key types."; case cleartext-private-key { leaf cleartext-private-key { Watsen Expires 11 January 2021 [Page 36] Internet-DrafYANG Data Types and Groupings for Cryptography July 2020 nacm:default-deny-all; type binary; must "../private-key-format"; description "The value of the binary key The key's value is interpreted by the 'private-key-format' field."; } } case hidden-private-key { leaf hidden-private-key { type empty; must "not(../private-key-format)"; description "A hidden key. How such keys are created is outside the scope of this module."; } } case encrypted-private-key { container encrypted-private-key { must "../private-key-format"; description "A container for the encrypted asymmetric private key value."; uses encrypted-key-value-grouping; } } } } grouping certificate-expiration-grouping { description "A notification for when a certificate is about to, or already has, expired."; notification certificate-expiration { description "A notification indicating that the configured certificate is either about to expire or has already expired. When to send notifications is an implementation specific decision, but it is RECOMMENDED that a notification be sent once a month for 3 months, then once a week for four weeks, and then once a day thereafter until the issue is resolved."; leaf expiration-date { type yang:date-and-time; mandatory true; description "Identifies the expiration date on the certificate."; } } Watsen Expires 11 January 2021 [Page 37] Internet-DrafYANG Data Types and Groupings for Cryptography July 2020 } grouping trust-anchor-cert-grouping { description "A trust anchor certificate, and a notification for when it is about to (or already has) expire."; leaf cert-data { nacm:default-deny-write; type trust-anchor-cert-cms; description "The binary certificate data for this certificate."; } uses certificate-expiration-grouping; } grouping end-entity-cert-grouping { description "An end entity certificate, and a notification for when it is about to (or already has) expire. Implementations SHOULD assert that, where used, the end entity certificate contains the expected public key."; leaf cert-data { nacm:default-deny-write; type end-entity-cert-cms; description "The binary certificate data for this certificate."; } uses certificate-expiration-grouping; } grouping generate-csr-grouping { description "Defines the 'generate-certificate-signing-request' action."; action generate-certificate-signing-request { if-feature certificate-signing-request-generation; nacm:default-deny-all; description "Generates a certificate signing request structure for the associated asymmetric key using the passed subject and attribute values. This action statement is only available when the associated 'public-key-format' node's value is 'subject-public-key-info-format'."; reference "RFC 6125: Representation and Verification of Domain-Based Application Service Identity within Internet Public Key Watsen Expires 11 January 2021 [Page 38] Internet-DrafYANG Data Types and Groupings for Cryptography July 2020 Infrastructure Using X.509 (PKIX) Certificates in the Context of Transport Layer Security (TLS)"; input { leaf csr-info { type ct:csr-info; mandatory true; description "A CertificationRequestInfo structure, as defined in RFC 2986. Enables the client to provide a fully-populated CertificationRequestInfo structure that the server only needs to sign in order to generate the complete 'CertificationRequest' structure to return in the 'output'. The 'AlgorithmIdentifier' field contained inside the 'SubjectPublicKeyInfo' field MUST be one known to be supported by the device."; reference "RFC 2986: PKCS #10: Certification Request Syntax Specification RFC AAAA: YANG Data Types and Groupings for Cryptography"; } } output { leaf certificate-signing-request { type ct:csr; mandatory true; description "A CertificationRequest structure, as defined in RFC 2986."; reference "RFC 2986: PKCS #10: Certification Request Syntax Specification RFC AAAA: YANG Data Types and Groupings for Cryptography"; } } } } // generate-csr-grouping grouping asymmetric-key-pair-with-cert-grouping { description "A private/public key pair and an associated certificate. Implementations SHOULD assert that certificates contain the matching public key."; Watsen Expires 11 January 2021 [Page 39] Internet-DrafYANG Data Types and Groupings for Cryptography July 2020 uses asymmetric-key-pair-grouping; uses end-entity-cert-grouping; uses generate-csr-grouping; } // asymmetric-key-pair-with-cert-grouping grouping asymmetric-key-pair-with-certs-grouping { description "A private/public key pair and associated certificates. Implementations SHOULD assert that certificates contain the matching public key."; uses asymmetric-key-pair-grouping; container certificates { nacm:default-deny-write; description "Certificates associated with this asymmetric key. More than one certificate supports, for instance, a TPM-protected asymmetric key that has both IDevID and LDevID certificates associated."; list certificate { key "name"; description "A certificate for this asymmetric key."; leaf name { type string; description "An arbitrary name for the certificate. If the name matches the name of a certificate that exists independently in (i.e., an IDevID), then the 'cert' node MUST NOT be configured."; } uses end-entity-cert-grouping { refine cert-data { mandatory true; } } } } uses generate-csr-grouping; } // asymmetric-key-pair-with-certs-grouping } 3. Security Considerations Watsen Expires 11 January 2021 [Page 40] Internet-DrafYANG Data Types and Groupings for Cryptography July 2020 3.1. No Support for CRMF This document uses PKCS #10 [RFC2986] for the "generate-certificate- signing-request" action. The use of Certificate Request Message Format (CRMF) [RFC4211] was considered, but is was unclear if there was market demand for it. If it is desired to support CRMF in the future, a backwards compatible solution can be defined at that time. 3.2. No Support for Key Generation Early revisions of this document included "rpc" statements for generating symmetric and asymmetric keys. There statements were removed due to an inability to obtain consensus for how to identify the key-algorithm to use. Thusly, the solution presented in this document only supports keys to be configured via an external client, which does not support Security best practice. 3.3. Strength of Keys Configured When configuring key values, implementations SHOULD ensure that the strength of the key being configured is not greater than the strength of the underlying secure transport connection over which it is communicated. Implementations SHOULD fail the write-request if ever the strength of the private key is greater then the strength of the underlying transport. 3.4. Deletion of Cleartext Key Values This module defines storage for cleartext key values that SHOULD be zeroized when deleted, so as to prevent the remnants of their persisted storage locations from being analyzed in any meaningful way. The cleartext key nodes are the "key" node defined in the "symmetric- key-grouping" grouping (Section 2.1.4.2) and the "private-key" node defined in the "asymmetric-key-pair-grouping" grouping ("Section 2.1.4.4). 3.5. The "ietf-crypto-types" YANG Module The YANG module in this document defines "grouping" statements that are 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. Watsen Expires 11 January 2021 [Page 41] Internet-DrafYANG Data Types and Groupings for Cryptography July 2020 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. Since the module in this document only define groupings, these considerations are primarily for the designers of other modules that use these groupings. Some of the readable data nodes defined in this YANG module may be considered sensitive or vulnerable in some network environments. It is thus important to control read access (e.g., via get, get-config, or notification) to these data nodes. These are the subtrees and data nodes and their sensitivity/vulnerability: * The "key" node: The cleartext "key" node defined in the "symmetric-key- grouping" grouping is additionally sensitive to read operations such that, in normal use cases, it should never be returned to a client. For this reason, the NACM extension "default-deny- all" has been applied to it. * The "private-key" node: The cleartext "private-key" node defined in the "asymmetric- key-pair-grouping" grouping is additionally sensitive to read operations such that, in normal use cases, it should never be returned to a client. For this reason, the NACM extension "default-deny-all" has been applied. All of the writable data nodes defined by all the groupings defined in this module may be considered sensitive or vulnerable in some network environments. For instance, even the modification of a public key or a certificate can dramatically alter the implemented security policy. For this reason, the NACM extension "default-deny- write" has been applied to all the data nodes defined in the module. Some of the operations in this YANG module may be considered sensitive or vulnerable in some network environments. It is thus important to control access to these operations. These are the operations and their sensitivity/vulnerability: * generate-certificate-signing-request: Watsen Expires 11 January 2021 [Page 42] Internet-DrafYANG Data Types and Groupings for Cryptography July 2020 This "action" statement SHOULD only be executed by authorized users. For this reason, the NACM extension "default-deny-all" has been applied. Note that NACM uses "default-deny-all" to protect "RPC" and "action" statements; it does not define, e.g., an extension called "default-deny-execute". For this action, it is RECOMMENDED that implementations assert channel binding [RFC5056], so as to ensure that the application layer that sent the request is the same as the device authenticated when the secure transport layer was established. 4. IANA Considerations 4.1. 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-crypto-types Registrant Contact: The NETCONF WG of the IETF. XML: N/A, the requested URI is an XML namespace. 4.2. 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-crypto-types namespace: urn:ietf:params:xml:ns:yang:ietf-crypto-types prefix: ct reference: RFC AAAA 5. References 5.1. Normative References [ITU.X680.2015] International Telecommunication Union, "Information technology - Abstract Syntax Notation One (ASN.1): Specification of basic notation", ITU-T Recommendation X.680, ISO/IEC 8824-1:2015, August 2015, . [ITU.X690.2015] International Telecommunication Union, "Information Technology - ASN.1 encoding rules: Specification of Basic Watsen Expires 11 January 2021 [Page 43] Internet-DrafYANG Data Types and Groupings for Cryptography July 2020 Encoding Rules (BER), Canonical Encoding Rules (CER) and Distinguished Encoding Rules (DER)", ITU-T Recommendation X.690, ISO/IEC 8825-1:2015, August 2015, . [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997, . [RFC3447] Jonsson, J. and B. Kaliski, "Public-Key Cryptography Standards (PKCS) #1: RSA Cryptography Specifications Version 2.1", RFC 3447, DOI 10.17487/RFC3447, February 2003, . [RFC4253] Ylonen, T. and C. Lonvick, Ed., "The Secure Shell (SSH) Transport Layer Protocol", RFC 4253, DOI 10.17487/RFC4253, January 2006, . [RFC5280] Cooper, D., Santesson, S., Farrell, S., Boeyen, S., Housley, R., and W. Polk, "Internet X.509 Public Key Infrastructure Certificate and Certificate Revocation List (CRL) Profile", RFC 5280, DOI 10.17487/RFC5280, May 2008, . [RFC5652] Housley, R., "Cryptographic Message Syntax (CMS)", STD 70, RFC 5652, DOI 10.17487/RFC5652, September 2009, . [RFC5958] Turner, S., "Asymmetric Key Packages", RFC 5958, DOI 10.17487/RFC5958, August 2010, . [RFC6031] Turner, S. and R. Housley, "Cryptographic Message Syntax (CMS) Symmetric Key Package Content Type", RFC 6031, DOI 10.17487/RFC6031, December 2010, . [RFC6991] Schoenwaelder, J., Ed., "Common YANG Data Types", RFC 6991, DOI 10.17487/RFC6991, July 2013, . [RFC7950] Bjorklund, M., Ed., "The YANG 1.1 Data Modeling Language", RFC 7950, DOI 10.17487/RFC7950, August 2016, . Watsen Expires 11 January 2021 [Page 44] Internet-DrafYANG Data Types and Groupings for Cryptography July 2020 [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, . 5.2. Informative References [I-D.ietf-netconf-crypto-types] Watsen, K., "Common YANG Data Types for Cryptography", Work in Progress, Internet-Draft, draft-ietf-netconf- crypto-types-15, 20 May 2020, . [I-D.ietf-netconf-http-client-server] Watsen, K., "YANG Groupings for HTTP Clients and HTTP Servers", Work in Progress, Internet-Draft, draft-ietf- netconf-http-client-server-03, 20 May 2020, . [I-D.ietf-netconf-keystore] Watsen, K., "A YANG Data Model for a Keystore", Work in Progress, Internet-Draft, draft-ietf-netconf-keystore-17, 20 May 2020, . [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-19, 20 May 2020, . [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-19, 20 May 2020, . [I-D.ietf-netconf-ssh-client-server] Watsen, K. and G. Wu, "YANG Groupings for SSH Clients and SSH Servers", Work in Progress, Internet-Draft, draft- Watsen Expires 11 January 2021 [Page 45] Internet-DrafYANG Data Types and Groupings for Cryptography July 2020 ietf-netconf-ssh-client-server-19, 20 May 2020, . [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- ietf-netconf-tcp-client-server-06, 16 June 2020, . [I-D.ietf-netconf-tls-client-server] Watsen, K. and G. Wu, "YANG Groupings for TLS Clients and TLS Servers", Work in Progress, Internet-Draft, draft- ietf-netconf-tls-client-server-19, 20 May 2020, . [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-10, 20 May 2020, . [RFC2986] Nystrom, M. and B. Kaliski, "PKCS #10: Certification Request Syntax Specification Version 1.7", RFC 2986, DOI 10.17487/RFC2986, November 2000, . [RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688, DOI 10.17487/RFC3688, January 2004, . [RFC4211] Schaad, J., "Internet X.509 Public Key Infrastructure Certificate Request Message Format (CRMF)", RFC 4211, DOI 10.17487/RFC4211, September 2005, . [RFC5056] Williams, N., "On the Use of Channel Bindings to Secure Channels", RFC 5056, DOI 10.17487/RFC5056, November 2007, . [RFC5915] Turner, S. and D. Brown, "Elliptic Curve Private Key Structure", RFC 5915, DOI 10.17487/RFC5915, June 2010, . Watsen Expires 11 January 2021 [Page 46] Internet-DrafYANG Data Types and Groupings for Cryptography July 2020 [RFC6020] Bjorklund, M., Ed., "YANG - A Data Modeling Language for the Network Configuration Protocol (NETCONF)", RFC 6020, DOI 10.17487/RFC6020, October 2010, . [RFC6125] Saint-Andre, P. and J. Hodges, "Representation and Verification of Domain-Based Application Service Identity within Internet Public Key Infrastructure Using X.509 (PKIX) Certificates in the Context of Transport Layer Security (TLS)", RFC 6125, DOI 10.17487/RFC6125, March 2011, . [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, . [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, . Appendix A. Change Log This section is to be removed before publishing as an RFC. A.1. I-D to 00 * Removed groupings and notifications. * Added typedefs for identityrefs. * Added typedefs for other RFC 5280 structures. * Added typedefs for other RFC 5652 structures. * Added convenience typedefs for RFC 4253, RFC 5280, and RFC 5652. A.2. 00 to 01 Watsen Expires 11 January 2021 [Page 47] Internet-DrafYANG Data Types and Groupings for Cryptography July 2020 * Moved groupings from the draft-ietf-netconf-keystore here. A.3. 01 to 02 * Removed unwanted "mandatory" and "must" statements. * Added many new crypto algorithms (thanks Haiguang!) * Clarified in asymmetric-key-pair-with-certs-grouping, in certificates/certificate/name/description, that if the name MUST NOT match the name of a certificate that exists independently in , enabling certs installed by the manufacturer (e.g., an IDevID). A.4. 02 to 03 * renamed base identity 'asymmetric-key-encryption-algorithm' to 'asymmetric-key-algorithm'. * added new 'asymmetric-key-algorithm' identities for secp192r1, secp224r1, secp256r1, secp384r1, and secp521r1. * removed 'mac-algorithm' identities for mac-aes-128-ccm, mac-aes- 192-ccm, mac-aes-256-ccm, mac-aes-128-gcm, mac-aes-192-gcm, mac- aes-256-gcm, and mac-chacha20-poly1305. * for all -cbc and -ctr identities, renamed base identity 'symmetric-key-encryption-algorithm' to 'encryption-algorithm'. * for all -ccm and -gcm identities, renamed base identity 'symmetric-key-encryption-algorithm' to 'encryption-and-mac- algorithm' and renamed the identity to remove the "enc-" prefix. * for all the 'signature-algorithm' based identities, renamed from 'rsa-*' to 'rsassa-*'. * removed all of the "x509v3-" prefixed 'signature-algorithm' based identities. * added 'key-exchange-algorithm' based identities for 'rsaes-oaep' and 'rsaes-pkcs1-v1_5'. * renamed typedef 'symmetric-key-encryption-algorithm-ref' to 'symmetric-key-algorithm-ref'. * renamed typedef 'asymmetric-key-encryption-algorithm-ref' to 'asymmetric-key-algorithm-ref'. Watsen Expires 11 January 2021 [Page 48] Internet-DrafYANG Data Types and Groupings for Cryptography July 2020 * added typedef 'encryption-and-mac-algorithm-ref'. * Updated copyright date, boilerplate template, affiliation, and folding algorithm. A.5. 03 to 04 * ran YANG module through formatter. A.6. 04 to 05 * fixed broken symlink causing reformatted YANG module to not show. A.7. 05 to 06 * Added NACM annotations. * Updated Security Considerations section. * Added 'asymmetric-key-pair-with-cert-grouping' grouping. * Removed text from 'permanently-hidden' enum regarding such keys not being backed up or restored. * Updated the boilerplate text in module-level "description" statement to match copyeditor convention. * Added an explanation to the 'public-key-grouping' and 'asymmetric- key-pair-grouping' statements as for why the nodes are not mandatory (e.g., because they may exist only in . * Added 'must' expressions to the 'public-key-grouping' and 'asymmetric-key-pair-grouping' statements ensuring sibling nodes are either all exist or do not all exist. * Added an explanation to the 'permanently-hidden' that the value cannot be configured directly by clients and servers MUST fail any attempt to do so. * Added 'trust-anchor-certs-grouping' and 'end-entity-certs- grouping' (the plural form of existing groupings). * Now states that keys created in by the *-hidden-key actions are bound to the lifetime of the parent 'config true' node, and that subsequent invocations of either action results in a failure. Watsen Expires 11 January 2021 [Page 49] Internet-DrafYANG Data Types and Groupings for Cryptography July 2020 A.8. 06 to 07 * Added clarifications that implementations SHOULD assert that configured certificates contain the matching public key. * Replaced the 'generate-hidden-key' and 'install-hidden-key' actions with special 'crypt-hash' -like input/output values. A.9. 07 to 08 * Removed the 'generate-key and 'hidden-key' features. * Added grouping symmetric-key-grouping * Modified 'asymmetric-key-pair-grouping' to have a 'choice' statement for the keystone module to augment into, as well as replacing the 'union' with leafs (having different NACM settings. A.10. 08 to 09 * Converting algorithm from identities to enumerations. A.11. 09 to 10 * All of the below changes are to the algorithm enumerations defined in ietf-crypto-types. * Add in support for key exchange over x.25519 and x.448 based on RFC 8418. * Add in SHAKE-128, SHAKE-224, SHAKE-256, SHAKE-384 and SHAKE 512 * Revise/add in enum of signature algorithm for x25519 and x448 * Add in des3-cbc-sha1 for IPSec * Add in sha1-des3-kd for IPSec * Add in definit for rc4-hmac and rc4-hmac-exp. These two algorithms have been deprecated in RFC 8429. But some existing draft in i2nsf may still want to use them. * Add x25519 and x448 curve for asymmetric algorithms * Add signature algorithms ed25519, ed25519-cts, ed25519ph * add signature algorithms ed448, ed448ph Watsen Expires 11 January 2021 [Page 50] Internet-DrafYANG Data Types and Groupings for Cryptography July 2020 * Add in rsa-sha2-256 and rsa-sha2-512 for SSH protocols (rfc8332) A.12. 10 to 11 * Added a "key-format" identity. * Added symmetric keys to the example in Section 2.2. A.13. 11 to 12 * Removed all non-essential (to NC/RC) algorithm types. * Moved remaining algorithm types each into its own module. * Added a 'config false' "algorithms-supported" list to each of the algorithm-type modules. A.14. 12 to 13 * Added the four features: "[encrypted-]one-[a]symmetric-key- format", each protecting a 'key-format' identity of the same name. * Added 'must' expressions asserting that the 'key-format' leaf exists whenever a non-hidden key is specified. * Improved the 'description' statements and added 'reference' statements for the 'key-format' identities. * Added a questionable forward reference to "encrypted-*" leafs in a couple 'when' expressions. * Did NOT move "config false" alg-supported lists to SSH/TLS drafts. A.15. 13 to 14 * Resolved the "FIXME: forward ref" issue by modulating 'must', 'when', and 'mandatory' expressions. * Moved the 'generatesymmetric-key' and 'generate-asymmetric-key' actions from ietf-keystore to ietf-crypto-types, now as RPCs. * Cleaned up various description statements and removed lingering FIXMEs. * Converted the "iana--algs" YANG modules to IANA registries with instructions for how to generate modules from the registries, whenever they may be updated. Watsen Expires 11 January 2021 [Page 51] Internet-DrafYANG Data Types and Groupings for Cryptography July 2020 A.16. 14 to 15 * Removed the IANA-maintained registries for symmetric, asymmetric, and hash algorithms. * Removed the "generate-symmetric-key" and "generate-asymmetric-key" RPCs. * Removed the "algorithm" node in the various symmetric and asymmetric key groupings. * Added 'typedef csr' and 'feature certificate-signing-request- generation'. * Refined a usage of "end-entity-cert-grouping" to make the "cert" node mandatory true. * Added a "Note to Reviewers" note to first page. A.17. 15 to 16 * Updated draft title (refer to "Groupings" too). * Removed 'end-entity-certs-grouping' as it wasn't being used anywhere. * Removed 'trust-anchor-certs-grouping' as it was no longer being used after modifying 'local-or-truststore-certs-grouping' to use lists (not leaf-lists). * Renamed "cert" to "cert-data" in trust-anchor-cert-grouping. * Added "csr-info" typedef, to complement the existing "csr" typedef. * Added "ocsp-request" and "ocsp-response" typedefs, to complement the existing "crl" typedef. * Added "encrypted" cases to both symmetric-key-grouping and asymmetric-key-pair-grouping (Moved from Keystore draft). * Expanded "Data Model Overview section(s) [remove "wall" of tree diagrams]. * Updated the Security Considerations section. A.18. 16 to 17 Watsen Expires 11 January 2021 [Page 52] Internet-DrafYANG Data Types and Groupings for Cryptography July 2020 * [Re]-added a "Strength of Keys Configured" Security Consideration * Prefixed "cleartext-" in the "key" and "private-key" node names. Acknowledgements The authors would like to thank for following for lively discussions on list and in the halls (ordered by first name): Balazs Kovacs, Eric Voit, Juergen Schoenwaelder, Liang Xia, Martin Bjorklund, Nick Hancock, Rich Salz, Rob Wilton, Tom Petch, and Wang Haiguang. Author's Address Kent Watsen Watsen Networks Email: kent+ietf@watsen.net Watsen Expires 11 January 2021 [Page 53]