--- 1/draft-ietf-rats-eat-12.txt 2022-05-20 14:13:13.052884099 -0700 +++ 2/draft-ietf-rats-eat-13.txt 2022-05-20 14:13:13.240888874 -0700 @@ -1,20 +1,20 @@ RATS Working Group L. Lundblade Internet-Draft Security Theory LLC Intended status: Standards Track G. Mandyam -Expires: August 27, 2022 J. O'Donoghue +Expires: November 21, 2022 J. O'Donoghue Qualcomm Technologies Inc. - February 23, 2022 + May 20, 2022 The Entity Attestation Token (EAT) - draft-ietf-rats-eat-12 + draft-ietf-rats-eat-13 Abstract An Entity Attestation Token (EAT) provides an attested claims set that describes state and characteristics of an entity, a device like a phone, IoT device, network equipment or such. This claims set is used by a relying party, server or service to determine how much it wishes to trust the entity. An EAT is either a CBOR Web Token (CWT) or JSON Web Token (JWT) with @@ -29,94 +29,88 @@ 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 August 27, 2022. + This Internet-Draft will expire on November 21, 2022. Copyright Notice Copyright (c) 2022 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 . . . . . . . . . . . . . . . . . . . . . . . . 5 1.1. Entity Overview . . . . . . . . . . . . . . . . . . . . . 6 - 1.2. CWT, JWT, UCCS, UJCS and DEB . . . . . . . . . . . . . . 7 + 1.2. CWT, JWT and DEB . . . . . . . . . . . . . . . . . . . . 7 1.3. CDDL, CBOR and JSON . . . . . . . . . . . . . . . . . . . 8 - 1.4. Operating Model and RATS Architecture . . . . . . . . . . 8 + 1.4. Operating Model and RATS Architecture . . . . . . . . . . 9 1.4.1. Relationship between Attestation Evidence and Attestation Results . . . . . . . . . . . . . . . . . 9 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 10 - 3. The Claims . . . . . . . . . . . . . . . . . . . . . . . . . 11 - 3.1. Token ID Claim (cti and jti) . . . . . . . . . . . . . . 11 - 3.2. Timestamp claim (iat) . . . . . . . . . . . . . . . . . . 11 - 3.3. Nonce Claim (nonce) . . . . . . . . . . . . . . . . . . . 12 - 3.4. Universal Entity ID Claim (ueid) . . . . . . . . . . . . 12 - 3.5. Semi-permanent UEIDs (SUEIDs) . . . . . . . . . . . . . . 15 - 3.6. Hardware OEM Identification (oemid) . . . . . . . . . . . 16 - 3.6.1. Random Number Based OEMID . . . . . . . . . . . . . . 16 - 3.6.2. IEEE Based OEMID . . . . . . . . . . . . . . . . . . 16 - 3.6.3. IANA Private Enterprise Number Based OEMID . . . . . 17 - 3.7. Hardware Model Claim (hardware-model) . . . . . . . . . . 17 - 3.8. Hardware Version Claims (hardware-version-claims) . . . . 18 - 3.9. Software Name Claim . . . . . . . . . . . . . . . . . . . 19 - 3.10. Software Version Claim . . . . . . . . . . . . . . . . . 19 - 3.11. The Security Level Claim (security-level) . . . . . . . . 19 - 3.12. Secure Boot Claim (secure-boot) . . . . . . . . . . . . . 21 - 3.13. Debug Status Claim (debug-status) . . . . . . . . . . . . 21 - 3.13.1. Enabled . . . . . . . . . . . . . . . . . . . . . . 22 - 3.13.2. Disabled . . . . . . . . . . . . . . . . . . . . . . 22 - 3.13.3. Disabled Since Boot . . . . . . . . . . . . . . . . 22 - 3.13.4. Disabled Permanently . . . . . . . . . . . . . . . . 22 - 3.13.5. Disabled Fully and Permanently . . . . . . . . . . . 22 - 3.14. Including Keys . . . . . . . . . . . . . . . . . . . . . 23 - 3.15. The Location Claim (location) . . . . . . . . . . . . . . 24 - 3.16. The Uptime Claim (uptime) . . . . . . . . . . . . . . . . 25 - 3.17. The Boot Odometer Claim (odometer) . . . . . . . . . . . 25 - 3.18. The Boot Seed Claim (boot-seed) . . . . . . . . . . . . . 25 - 3.19. The Intended Use Claim (intended-use) . . . . . . . . . . 26 - 3.20. The Profile Claim (profile) . . . . . . . . . . . . . . . 27 - 3.21. The DLOA (Digital Letter or Approval) Claim (dloas) . . . 27 - 3.22. The Software Manifests Claim (manifests) . . . . . . . . 28 - 3.23. The Software Evidence Claim (swevidence) . . . . . . . . 30 - 3.24. The SW Measurement Results Claim (swresults) . . . . . . 30 - 3.24.1. Scheme . . . . . . . . . . . . . . . . . . . . . . . 31 - 3.24.2. Objective . . . . . . . . . . . . . . . . . . . . . 31 - 3.24.3. Results . . . . . . . . . . . . . . . . . . . . . . 31 - 3.24.4. Objective Name . . . . . . . . . . . . . . . . . . . 32 - 3.25. Submodules (submods) . . . . . . . . . . . . . . . . . . 34 - 3.25.1. Submodule Types . . . . . . . . . . . . . . . . . . 34 - 3.25.1.1. Submodule Claims-Set . . . . . . . . . . . . . . 34 - 3.25.1.2. Nested Token . . . . . . . . . . . . . . . . . . 35 - 3.25.1.3. Detached Submodule Digest . . . . . . . . . . . 37 - 3.25.2. No Inheritance . . . . . . . . . . . . . . . . . . . 38 - 3.25.3. Security Levels . . . . . . . . . . . . . . . . . . 38 - 3.25.4. Submodule Names . . . . . . . . . . . . . . . . . . 39 - 3.25.5. CDDL for submods . . . . . . . . . . . . . . . . . . 39 - 4. Unprotected JWT Claims-Sets . . . . . . . . . . . . . . . . . 39 + 3. Top-Level Token Definition . . . . . . . . . . . . . . . . . 11 + 4. The Claims . . . . . . . . . . . . . . . . . . . . . . . . . 12 + 4.1. Nonce Claim (nonce) . . . . . . . . . . . . . . . . . . . 12 + 4.2. Claims Describing the Entity . . . . . . . . . . . . . . 13 + 4.2.1. Universal Entity ID Claim (ueid) . . . . . . . . . . 13 + 4.2.2. Semi-permanent UEIDs (SUEIDs) . . . . . . . . . . . . 16 + 4.2.3. Hardware OEM Identification (oemid) . . . . . . . . . 17 + 4.2.3.1. Random Number Based OEMID . . . . . . . . . . . . 17 + 4.2.3.2. IEEE Based OEMID . . . . . . . . . . . . . . . . 17 + 4.2.3.3. IANA Private Enterprise Number Based OEMID . . . 18 + 4.2.4. Hardware Model Claim (hardware-model) . . . . . . . . 18 + 4.2.5. Hardware Version Claims (hardware-version-claims) . . 19 + 4.2.6. Software Name Claim . . . . . . . . . . . . . . . . . 20 + 4.2.7. Software Version Claim . . . . . . . . . . . . . . . 20 + 4.2.8. The Security Level Claim (security-level) . . . . . . 20 + 4.2.9. Secure Boot Claim (secure-boot) . . . . . . . . . . . 21 + 4.2.10. Debug Status Claim (debug-status) . . . . . . . . . . 22 + 4.2.10.1. Enabled . . . . . . . . . . . . . . . . . . . . 23 + 4.2.10.2. Disabled . . . . . . . . . . . . . . . . . . . . 23 + 4.2.10.3. Disabled Since Boot . . . . . . . . . . . . . . 23 + 4.2.10.4. Disabled Permanently . . . . . . . . . . . . . . 23 + 4.2.10.5. Disabled Fully and Permanently . . . . . . . . . 23 + 4.2.11. The Location Claim (location) . . . . . . . . . . . . 24 + 4.2.12. The Uptime Claim (uptime) . . . . . . . . . . . . . . 25 + 4.2.13. The Boot Odometer Claim (odometer) . . . . . . . . . 25 + 4.2.14. The Boot Seed Claim (boot-seed) . . . . . . . . . . . 25 + 4.2.15. The DLOA (Digital Letter of Approval) Claim (dloas) . 26 + 4.2.16. The Software Manifests Claim (manifests) . . . . . . 26 + 4.2.17. The Software Evidence Claim (swevidence) . . . . . . 28 + 4.2.18. The Measurement Results Claim (measurement-results) . 29 + 4.2.19. Submodules (submods) . . . . . . . . . . . . . . . . 31 + 4.2.19.1. Submodule Types . . . . . . . . . . . . . . . . 32 + 4.2.19.2. No Inheritance . . . . . . . . . . . . . . . . . 36 + 4.2.19.3. Security Levels . . . . . . . . . . . . . . . . 36 + 4.2.19.4. Submodule Names . . . . . . . . . . . . . . . . 36 + 4.3. Claims Describing the Token . . . . . . . . . . . . . . . 36 + 4.3.1. Token ID Claim (cti and jti) . . . . . . . . . . . . 36 + 4.3.2. Timestamp claim (iat) . . . . . . . . . . . . . . . . 37 + 4.3.3. The Profile Claim (profile) . . . . . . . . . . . . . 37 + 4.3.4. The Intended Use Claim (intended-use) . . . . . . . . 37 + 4.4. Including Keys . . . . . . . . . . . . . . . . . . . . . 38 5. Detached EAT Bundles . . . . . . . . . . . . . . . . . . . . 39 6. Endorsements and Verification Keys . . . . . . . . . . . . . 40 6.1. Identification Methods . . . . . . . . . . . . . . . . . 41 6.1.1. COSE/JWS Key ID . . . . . . . . . . . . . . . . . . . 41 6.1.2. JWS and COSE X.509 Header Parameters . . . . . . . . 42 6.1.3. CBOR Certificate COSE Header Parameters . . . . . . . 42 6.1.4. Claim-Based Key Identification . . . . . . . . . . . 42 6.2. Other Considerations . . . . . . . . . . . . . . . . . . 42 7. Profiles . . . . . . . . . . . . . . . . . . . . . . . . . . 43 7.1. Format of a Profile Document . . . . . . . . . . . . . . 43 @@ -137,83 +131,94 @@ 7.2.14. Refined Claim Definition . . . . . . . . . . . . . . 46 7.2.15. CBOR Tags . . . . . . . . . . . . . . . . . . . . . . 46 7.2.16. Manifests and Software Evidence Claims . . . . . . . 46 8. Encoding and Collected CDDL . . . . . . . . . . . . . . . . . 46 8.1. Claims-Set and CDDL for CWT and JWT . . . . . . . . . . . 46 8.2. Encoding Data Types . . . . . . . . . . . . . . . . . . . 47 8.2.1. Common Data Types . . . . . . . . . . . . . . . . . . 47 8.2.2. JSON Interoperability . . . . . . . . . . . . . . . . 47 8.2.3. Labels . . . . . . . . . . . . . . . . . . . . . . . 48 8.3. CBOR Interoperability . . . . . . . . . . . . . . . . . . 48 - 8.3.1. EAT Constrained Device Serialization . . . . . . . . 48 - 8.4. Collected Common CDDL . . . . . . . . . . . . . . . . . . 49 - 8.5. Collected CDDL for CBOR . . . . . . . . . . . . . . . . . 54 - 8.6. Collected CDDL for JSON . . . . . . . . . . . . . . . . . 55 + 8.3.1. EAT Constrained Device Serialization . . . . . . . . 49 + 8.4. Collected CDDL . . . . . . . . . . . . . . . . . . . . . 49 + 8.4.1. Payload CDDL . . . . . . . . . . . . . . . . . . . . 49 + 8.4.2. CBOR-Specific CDDL . . . . . . . . . . . . . . . . . 55 + 8.4.3. JSON-Specific CDDL . . . . . . . . . . . . . . . . . 56 9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 56 9.1. Reuse of CBOR and JSON Web Token (CWT and JWT) Claims Registries . . . . . . . . . . . . . . . . . . . . . . . 56 - 9.2. Claim Characteristics . . . . . . . . . . . . . . . . . . 57 - 9.2.1. Interoperability and Relying Party Orientation . . . 57 + 9.2. Claim Characteristics . . . . . . . . . . . . . . . . . . 56 + 9.2.1. Interoperability and Relying Party Orientation . . . 56 9.2.2. Operating System and Technology Neutral . . . . . . . 57 - 9.2.3. Security Level Neutral . . . . . . . . . . . . . . . 58 - 9.2.4. Reuse of Extant Data Formats . . . . . . . . . . . . 58 + 9.2.3. Security Level Neutral . . . . . . . . . . . . . . . 57 + 9.2.4. Reuse of Extant Data Formats . . . . . . . . . . . . 57 9.2.5. Proprietary Claims . . . . . . . . . . . . . . . . . 58 9.3. Claims Registered by This Document . . . . . . . . . . . 58 - 9.3.1. Claims for Early Assignment . . . . . . . . . . . . . 59 + 9.3.1. Claims for Early Assignment . . . . . . . . . . . . . 58 9.3.2. To be Assigned Claims . . . . . . . . . . . . . . . . 62 9.3.3. Version Schemes Registered by this Document . . . . . 65 - 9.3.4. UEID URN Registered by this Document . . . . . . . . 66 + 9.3.4. UEID URN Registered by this Document . . . . . . . . 65 9.3.5. Tag for Detached EAT Bundle . . . . . . . . . . . . . 66 10. Privacy Considerations . . . . . . . . . . . . . . . . . . . 66 - 10.1. UEID and SUEID Privacy Considerations . . . . . . . . . 67 + 10.1. UEID and SUEID Privacy Considerations . . . . . . . . . 66 10.2. Location Privacy Considerations . . . . . . . . . . . . 67 - 10.3. Replay Protection and Privacy . . . . . . . . . . . . . 68 + 10.3. Replay Protection and Privacy . . . . . . . . . . . . . 67 11. Security Considerations . . . . . . . . . . . . . . . . . . . 68 11.1. Key Provisioning . . . . . . . . . . . . . . . . . . . . 68 - 11.1.1. Transmission of Key Material . . . . . . . . . . . . 69 - 11.2. Transport Security . . . . . . . . . . . . . . . . . . . 69 + 11.1.1. Transmission of Key Material . . . . . . . . . . . . 68 + 11.2. Transport Security . . . . . . . . . . . . . . . . . . . 68 11.3. Multiple EAT Consumers . . . . . . . . . . . . . . . . . 69 - 12. References . . . . . . . . . . . . . . . . . . . . . . . . . 70 - 12.1. Normative References . . . . . . . . . . . . . . . . . . 70 - 12.2. Informative References . . . . . . . . . . . . . . . . . 73 - Appendix A. Examples . . . . . . . . . . . . . . . . . . . . . . 76 - A.1. Simple TEE Attestation . . . . . . . . . . . . . . . . . 76 - A.2. Submodules for Board and Device . . . . . . . . . . . . . 77 - A.3. EAT Produced by Attestation Hardware Block . . . . . . . 79 - A.4. Detached EAT Bundle . . . . . . . . . . . . . . . . . . . 79 - A.5. Key / Key Store Attestation . . . . . . . . . . . . . . . 81 - A.6. SW Measurements of an IoT Device . . . . . . . . . . . . 83 - A.7. Attestation Results in JSON format . . . . . . . . . . . 86 - Appendix B. UEID Design Rationale . . . . . . . . . . . . . . . 87 - B.1. Collision Probability . . . . . . . . . . . . . . . . . . 87 - B.2. No Use of UUID . . . . . . . . . . . . . . . . . . . . . 89 + 12. References . . . . . . . . . . . . . . . . . . . . . . . . . 69 + 12.1. Normative References . . . . . . . . . . . . . . . . . . 69 + 12.2. Informative References . . . . . . . . . . . . . . . . . 72 + Appendix A. Examples . . . . . . . . . . . . . . . . . . . . . . 75 + A.1. Payload Examples . . . . . . . . . . . . . . . . . . . . 75 + A.1.1. Simple TEE Attestation . . . . . . . . . . . . . . . 75 + A.1.2. Submodules for Board and Device . . . . . . . . . . . 77 + A.1.3. EAT Produced by Attestation Hardware Block . . . . . 79 + A.1.4. Key / Key Store Attestation . . . . . . . . . . . . . 79 + A.1.5. Submodules for Board and Device . . . . . . . . . . . 81 + A.1.6. EAT Produced by Attestation Hardware Block . . . . . 83 + A.1.7. Key / Key Store Attestation . . . . . . . . . . . . . 83 + A.1.8. SW Measurements of an IoT Device . . . . . . . . . . 85 + A.1.9. Attestation Results in JSON format . . . . . . . . . 87 + A.1.10. JSON-encoded Token with Sumodules . . . . . . . . . . 88 + A.2. Full Token Examples . . . . . . . . . . . . . . . . . . . 89 + A.2.1. Basic CWT Example . . . . . . . . . . . . . . . . . . 89 + A.2.2. Detached EAT Bundle . . . . . . . . . . . . . . . . . 90 + A.2.3. JSON-encoded Detached EAT Bundle . . . . . . . . . . 92 + Appendix B. UEID Design Rationale . . . . . . . . . . . . . . . 92 + B.1. Collision Probability . . . . . . . . . . . . . . . . . . 93 + B.2. No Use of UUID . . . . . . . . . . . . . . . . . . . . . 95 Appendix C. EAT Relation to IEEE.802.1AR Secure Device Identity - (DevID) . . . . . . . . . . . . . . . . . . . . . . 90 - C.1. DevID Used With EAT . . . . . . . . . . . . . . . . . . . 90 - C.2. How EAT Provides an Equivalent Secure Device Identity . . 91 - C.3. An X.509 Format EAT . . . . . . . . . . . . . . . . . . . 91 - C.4. Device Identifier Permanence . . . . . . . . . . . . . . 92 - Appendix D. Changes from Previous Drafts . . . . . . . . . . . . 92 - D.1. From draft-rats-eat-01 . . . . . . . . . . . . . . . . . 92 - D.2. From draft-mandyam-rats-eat-00 . . . . . . . . . . . . . 92 - D.3. From draft-ietf-rats-eat-01 . . . . . . . . . . . . . . . 92 - D.4. From draft-ietf-rats-eat-02 . . . . . . . . . . . . . . . 93 - D.5. From draft-ietf-rats-eat-03 . . . . . . . . . . . . . . . 93 - D.6. From draft-ietf-rats-eat-04 . . . . . . . . . . . . . . . 93 - D.7. From draft-ietf-rats-eat-05 . . . . . . . . . . . . . . . 94 - D.8. From draft-ietf-rats-eat-06 . . . . . . . . . . . . . . . 94 - D.9. From draft-ietf-rats-eat-07 . . . . . . . . . . . . . . . 94 - D.10. From draft-ietf-rats-eat-08 . . . . . . . . . . . . . . . 94 - D.11. From draft-ietf-rats-eat-09 . . . . . . . . . . . . . . . 94 - D.12. From draft-ietf-rats-eat-10 . . . . . . . . . . . . . . . 95 - D.13. From draft-ietf-rats-eat-11 . . . . . . . . . . . . . . . 96 - Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 96 + (DevID) . . . . . . . . . . . . . . . . . . . . . . 96 + C.1. DevID Used With EAT . . . . . . . . . . . . . . . . . . . 96 + C.2. How EAT Provides an Equivalent Secure Device Identity . . 97 + C.3. An X.509 Format EAT . . . . . . . . . . . . . . . . . . . 97 + C.4. Device Identifier Permanence . . . . . . . . . . . . . . 98 + Appendix D. CDDL for CWT and JWT . . . . . . . . . . . . . . . . 98 + Appendix E. Changes from Previous Drafts . . . . . . . . . . . . 100 + E.1. From draft-rats-eat-01 . . . . . . . . . . . . . . . . . 100 + E.2. From draft-mandyam-rats-eat-00 . . . . . . . . . . . . . 100 + E.3. From draft-ietf-rats-eat-01 . . . . . . . . . . . . . . . 100 + E.4. From draft-ietf-rats-eat-02 . . . . . . . . . . . . . . . 100 + E.5. From draft-ietf-rats-eat-03 . . . . . . . . . . . . . . . 101 + E.6. From draft-ietf-rats-eat-04 . . . . . . . . . . . . . . . 101 + E.7. From draft-ietf-rats-eat-05 . . . . . . . . . . . . . . . 102 + E.8. From draft-ietf-rats-eat-06 . . . . . . . . . . . . . . . 102 + E.9. From draft-ietf-rats-eat-07 . . . . . . . . . . . . . . . 102 + E.10. From draft-ietf-rats-eat-08 . . . . . . . . . . . . . . . 102 + E.11. From draft-ietf-rats-eat-09 . . . . . . . . . . . . . . . 102 + E.12. From draft-ietf-rats-eat-10 . . . . . . . . . . . . . . . 103 + E.13. From draft-ietf-rats-eat-11 . . . . . . . . . . . . . . . 104 + E.14. From draft-ietf-rats-eat-12 . . . . . . . . . . . . . . . 104 + Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 105 1. Introduction EAT provides the definition of a base set of claims that can be made about an entity, a device, some software and/or some hardware. This claims set is received by a relying party who uses it to decide if and how it will interact with the remote entity. It may choose to not trust the entity and not interact with it. It may choose to trust it. It may partially trust it, for example allowing monetary transactions only up to a limit. @@ -276,24 +281,24 @@ An entity also corresponds to a "system component" as defined in the Internet Security Glossary [RFC4949]. That glossary also defines "entity" and "system entity" as something that may be a person or organization as well as a system component. Here "entity" never refers to a person or organization. An entity is never a server or a service. An entity may be the whole device or it may be a subsystem, a subsystem of a subsystem and so on. EAT allows claims to be - organized into submodules, nested EATs and so on. See Section 3.25. - The entity to which a claim applies is the submodule in which it - appears, or to the top-level entity if it doesn't appear in a - submodule. + organized into submodules, nested EATs and so on. See + Section 4.2.19. The entity to which a claim applies is the submodule + in which it appears, or to the top-level entity if it doesn't appear + in a submodule. Some examples of entities: o A Secure Element o A TEE o A card in a network router o A network router, perhaps with each card in the router a submodule @@ -306,81 +311,84 @@ o A smartphone with many submodules for its many subsystems o A subsystem in a smartphone like the modem or the camera An entity may have strong security like defenses against hardware invasive attacks. It may also have low security, having no special security defenses. There is no minimum security requirement to be an entity. -1.2. CWT, JWT, UCCS, UJCS and DEB +1.2. CWT, JWT and DEB - An EAT is a claims set about an entity based on one of the following: + An EAT is primarily a claims set about an entity based on one of the + following: o CBOR Web Token (CWT) [RFC8392] - o Unprotected CWT Claims Sets (UCCS) [UCCS.Draft] - o JSON Web Token (JWT) [RFC7519] All definitions, requirements, creation and validation procedures, security considerations, IANA registrations and so on from these carry over to EAT. This specification extends those specifications by defining additional claims for attestation. This specification also describes the notion of a "profile" that can narrow the definition of an EAT, ensure interoperability and fill in details for specific usage scenarios. This specification also adds some considerations for registration of future EAT-related claims. The identification of a protocol element as an EAT, whether CBOR or - JSON encoded, follows the general conventions used by CWT, JWT and - UCCS. Largely this depends on the protocol carrying the EAT. In - some cases it may be by content type (e.g., MIME type). In other - cases it may be through use of CBOR tags. There is no fixed - mechanism across all use cases. - - This specification adds two more top-level messages: + JSON encoded, follows the general conventions used by CWT, JWT. + Largely this depends on the protocol carrying the EAT. In some cases + it may be by content type (e.g., MIME type). In other cases it may + be through use of CBOR tags. There is no fixed mechanism across all + use cases. - o Unprotected JWT Claims Set (UJCS) Section 4 + This specification adds one more top-level token type: o Detached EAT Bundle (DEB), Section 5 A DEB is structure to hold a collection of detached claims sets and the EAT that separately provides integrity and authenticity protection for them. It can be either CBOR or JSON encoded. + Last, the definition of other token types is allowed. Of particular + use may be a token type that provides no authenticity or integrity + protection at all for use with transports like TLS that do provide + that. + 1.3. CDDL, CBOR and JSON This document defines Concise Binary Object Representation (CBOR) [RFC8949] and Javascript Object Notation (JSON) [RFC7159] encoding for an EAT. All claims in an EAT MUST use the same encoding except where explicitly allowed. It is explicitly allowed for a nested token to be of a different encoding. Some claims explicitly contain objects and messages that may use a different encoding than the enclosing EAT. This specification uses Concise Data Definition Language (CDDL) [RFC8610] for all definitions. The implementor interprets the CDDL to come to either the CBOR or JSON encoding. In the case of JSON, Appendix E of [RFC8610] is followed. Additional rules are given in Section 8.2.2 where Appendix E is insufficient. + In most cases where the CDDL for CBOR is different than JSON a CDDL + Generic named "JC<>" is used. It is described in Appendix D. + The CWT and JWT specifications were authored before CDDL was available and did not use CDDL. This specification includes a CDDL definition of most of what is defined in [RFC8392]. Similarly, this specification includes CDDL for most of what is defined in [RFC7519]. - - The UCCS specification does not include CDDL. This specification - provides CDDL for it. + These definitions are in Appendix D and are not normative. 1.4. Operating Model and RATS Architecture While it is not required that EAT be used with the RATS operational model described in Figure 1 in [RATS.Architecture], or even that it be used for attestation, this document is oriented around that model. To summarize, an Attester generates Attestation Evidence. Attestation Evidence is a claims set describing various characteristics of an entity. Attestation Evidence also is usually @@ -400,41 +408,52 @@ Note that sometimes the Verifier and Relying Party are not separate and thus there is no need for a protocol to carry Attestation Results. 1.4.1. Relationship between Attestation Evidence and Attestation Results Any claim defined in this document or in the IANA CWT or JWT registry may be used in Attestation Evidence or Attestation Results. - Many claims in Attestation Evidence simply will pass through the - Verifier to the Relying Party without modification. They will be - verified as authentic from the entity by the Verifier just through - normal verification of the Attester's signature. The UEID, - Section 3.4, and Location, Section 3.15, are examples of claims that - may be passed through. + The relationship of claims in Attestation Results to Attestation + Evidence is fundamentally governed by the Verifier and the Verifier's + Policy. - Some claims in Attestation Evidence will be verified by the Verifier - by comparison to Reference Values. These claims will not likely be - conveyed to the Relying Party. Instead, some claim indicating they - were checked may be added to the Attestation Results or it may be - tacitly known that the Verifier always does this check. For example, - the Verifier receives the Software Evidence claim, Section 3.23, - compares it to Reference Values and conveys the results to the - Relying Party in a Software Measurement Results Claim, Section 3.24. + A common use case is for the Verifier and its Policy to perform + checks, calculations and processing with Attestation Evidence as the + input to produce a summary result in Attestation Results that + indicates the overall health and status of the entity. For example, + measurements in Attestation Evidence may be compared to Reference + Values the results of which are represented as a simple pass/fail in + Attestation Results. - In some cases the Verifier may provide privacy-preserving - functionality by stripping or modifying claims that do not posses - sufficient privacy-preserving characteristics. For example, the data - in the Location claim, Section 3.15, may be modified to have a - precision of a few kilometers rather than a few meters. + It is also possible that some claims in the Attestation Evidence will + be forwarded unmodified to the Relying Party in Attestation Results. + This forwarding is subject to the Verifier's implementation and + Policy. The Relying Party should be aware of the Verifier's Policy + to know what checks it has performed on claims it forwards. + + The Verifier may also modify or transform claims it forwards. This + may be to implement some privacy preservation functionality. + + It is also possible the Verifier will put claims in the Attestation + Results that give details about the entity that it has computed or + looked up in a database. For example, the Verifier may be able to + put a HW OEM ID Claim in the Attestation Results by performing a look + up based on a UEID (serial number) it received in Attestation + Evidence. + + There are no fixed rules for how a Verifier processes Attestation + Evidence to produce Attestation Results. What is important is the + Relying Party understand what the Verifier does and what its policies + are. 2. Terminology The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all capitals, as shown here. This document reuses terminology from JWT [RFC7519] and CWT @@ -480,94 +498,120 @@ vouches for the validity of the results Reference Values: A set of values against which values of Claims can be compared as part of applying an Appraisal Policy for Attestation Evidence. Reference Values are sometimes referred to in other documents as known-good values, golden measurements, or nominal values, although those terms typically assume comparison for equality, whereas here Reference Values might be more general and be used in any sort of comparison. -3. The Claims +3. Top-Level Token Definition + + An EAT is a "message", a "token", or such whose content is a Claims- + Set about an entity or some number of entities. An EAT MUST always + contains a Claims-Set. + + An EAT may be encoded in CBOR or JSON as defined here. While not + encouraged, other documents may define EAT encoding in other formats. + + EAT as defined here is always integrity and authenticity protected + through use of CWT or JWT. Other token formats using other methods + of protection may be defined outside this document. + + This document also defines the Detatched EAT Bundle Section 5, a + bundle of some detached Claims-Sets and CWTs or JWTs that provide + protection for the detached Claims-Set. + + The following CDDL defines the top-levels of an EAT token as a socket + indicating future token formats may be defined. See Appendix D for + the CDDL definitions of a CWT and JWT. + + Nesting of EATs is allowed and defined in Section 4.2.19.1.2. This + nesting includes nesting of a token that is a different format than + the enclosing token. The definition of Nested-Token references the + CDDL defined in this section. When new token formats are defined, + the means for identification in a nested token MUST also be defined. + + EAT-CBOR-Token = $$EAT-CBOR-Tagged-Token / $$EAT-CBOR-Untagged-Token + + $$EAT-CBOR-Tagged-Token /= CWT-Tagged-Message + $$EAT-CBOR-Tagged-Token /= DEB-Tagged-Message + + $$EAT-CBOR-Untagged-Token /= CWT-Untagged-Message + $$EAT-CBOR-Untagged-Token /= DEB-Untagged-Message + + EAT-JSON-Token = $$EAT-JSON-Token-Formats + + $$EAT-JSON-Token-Formats /= JWT-Message + $$EAT-JSON-Token-Formats /= DEB-Untagged-Message + +4. The Claims This section describes new claims defined for attestation that are to be added to the CWT [IANA.CWT.Claims] and JWT [IANA.JWT.Claims] IANA registries. This section also describes how several extant CWT and JWT claims apply in EAT. CDDL, along with a text description, is used to define each claim independent of encoding. Each claim is defined as a CDDL group. In Section 8 on encoding, the CDDL groups turn into CBOR map entries and JSON name/value pairs. Each claim described has a unique text string and integer that identifies it. CBOR encoded tokens MUST use only the integer for Claim Keys. JSON encoded tokens MUST use only the text string for Claim Names. -3.1. Token ID Claim (cti and jti) - - CWT defines the "cti" claim. JWT defines the "jti" claim. These are - equivalent to each other in EAT and carry a unique token identifier - as they do in JWT and CWT. They may be used to defend against re use - of the token but are distinct from the nonce that is used by the - Relying Party to guarantee freshness and defend against replay. - -3.2. Timestamp claim (iat) +4.1. Nonce Claim (nonce) - The "iat" claim defined in CWT and JWT is used to indicate the date- - of-creation of the token, the time at which the claims are collected - and the token is composed and signed. + All EATs MUST have a nonce to prevent replay attacks. - The data for some claims may be held or cached for some period of - time before the token is created. This period may be long, even - days. Examples are measurements taken at boot or a geographic - position fix taken the last time a satellite signal was received. - There are individual timestamps associated with these claims to - indicate their age is older than the "iat" timestamp. + This claim is either a single byte or text string or an array of byte + or text strings. The array is to accommodate multistage EAT + verification and consumption. See the extensive discussion on + attestation freshness in Appendix A of RATS Architecture + [RATS.Architecture]. - CWT allows the use floating-point for this claim. EAT disallows the - use of floating-point. An EAT token MUST NOT contain an iat claim in - float-point format. Any recipient of a token with a floating-point - format iat claim MUST consider it an error. A 64-bit integer - representation of epoch time can represent a range of +/- 500 billion - years, so the only point of a floating-point timestamp is to have - precession greater than one second. This is not needed for EAT. + A claim named "nonce" is previously defined and registered with IANA + for JWT, but MUST not be used in an EAT. It does not support + multiple nonces. No previous nonce claim was defined for CWT. -3.3. Nonce Claim (nonce) + The nonce MUST have 64 bits of entropy as fewer bits are unlikely to + be secure. A maximum nonce size is set to limit the memory required + for an implementation. All receivers MUST be able to accommodate the + maximum size. - All EATs should have a nonce to prevent replay attacks. The nonce is - generated by the Relying Party, the end consumer of the token. It is - conveyed to the entity over whatever transport is in use before the - token is generated and then included in the token as the nonce claim. + In CBOR, the nonce is a byte string and every bit in the byte string + contributes to entropy. The minimum size is 8 bytes. The maximum + size is 64 bytes. - This documents the nonce claim for registration in the IANA CWT - claims registry. This is equivalent to the JWT nonce claim that is - already registered. + In JSON the nonce is a text string. It is assumed that the only + characters represented by the lower 7 bits will be used so the text + string must be one-seventh longer. The minimum size is 10 bytes. + The maximum size is 74 bytes. - The nonce must be at least 8 bytes (64 bits) long as fewer bytes are - unlikely to be secure. A maximum of 64 bytes is set to limit the - memory a constrained implementation uses. This size range is not set - for the already-registered JWT nonce, but it should follow this size - recommendation when used in an EAT. + $$Claims-Set-Claims //= + (nonce-label => nonce-type / [ 2* nonce-type ]) - Multiple nonces are allowed to accommodate multistage verification - and consumption. + nonce-type = JC< tstr .size (10..74), bstr .size (8..64)> - $$claims-set-claims //= - (nonce-label => nonce-type / [ 2* nonce-type ]) +4.2. Claims Describing the Entity - nonce-type = bstr .size (8..64) + The claims in this section describe the entity itself. They describe + the entity whether they occur in Attestation Evidence or occur in + Attestation Results. See Section 1.4.1 for discussion on how + Attestation Results relate to Attestation Evidence. -3.4. Universal Entity ID Claim (ueid) +4.2.1. Universal Entity ID Claim (ueid) A UEID identifies an individual manufactured entity like a mobile phone, a water meter, a Bluetooth speaker or a networked security camera. It may identify the entire entity or a submodule. It does not identify types, models or classes of entities. It is akin to a serial number, though it does not have to be sequential. UEIDs MUST be universally and globally unique across manufacturers and countries. UEIDs MUST also be unique across protocols and systems, as tokens are intended to be embedded in many different @@ -626,46 +670,44 @@ | | | 0x33). The IMEI value encoded SHALL NOT include | | | | Luhn checksum or SVN information. See | | | | [ThreeGPP.IMEI]. | +------+------+-----------------------------------------------------+ Table 1: UEID Composition Types UEIDs are not designed for direct use by humans (e.g., printing on the case of a device), so no textual representation is defined. - The consumer (the Relying Party) of a UEID MUST treat a UEID as a - completely opaque string of bytes and not make any use of its - internal structure. For example, they should not use the OUI part of - a type 0x02 UEID to identify the manufacturer of the entity. - Instead, they should use the OEMID claim. See Section 3.6. The - reasons for this are: + The consumer of a UEID MUST treat a UEID as a completely opaque + string of bytes and not make any use of its internal structure. For + example, they should not use the OUI part of a type 0x02 UEID to + identify the manufacturer of the entity. Instead, they should use + the OEMID claim. See Section 4.2.3. The reasons for this are: o UEIDs types may vary freely from one manufacturer to the next. o New types of UEIDs may be created. For example, a type 0x07 UEID may be created based on some other manufacturer registration scheme. - o Entity manufacturers are allowed to change from one type of UEID - to another anytime they want. For example, they may find they can - optimize their manufacturing by switching from type 0x01 to type - 0x02 or vice versa. The essential requirement on the manufacturer - is that UEIDs be universally unique. + o The manufacturing process for an entity is allowed to change from + using one type of UEID to another. For example, a manufacturer + may find they can optimize their process by switching from type + 0x01 to type 0x02 or vice versa. A Device Identifier URN is registered for UEIDs. See Section 9.3.4. - $$claims-set-claims //= (ueid-label => ueid-type) + $$Claims-Set-Claims //= (ueid-label => ueid-type) - ueid-type = bstr .size (7..33) + ueid-type = JC -3.5. Semi-permanent UEIDs (SUEIDs) +4.2.2. Semi-permanent UEIDs (SUEIDs) An SEUID is of the same format as a UEID, but it MAY change to a different value on device life-cycle events. Examples of these events are change of ownership, factory reset and on-boarding into an IoT device management system. An entity MAY have both a UEID and SUEIDs, neither, one or the other. There MAY be multiple SUEIDs. Each one has a text string label the purpose of which is to distinguish it from others in the token. The label MAY name the purpose, application or type of the SUEID. @@ -674,53 +716,53 @@ SUEIDs should be labeled. If there is only one SUEID, the claim remains a map and there still must be a label. For example, the label for the SUEID used by FIDO Onboarding Protocol could simply be "FDO". There are privacy considerations for SUEIDs. See Section 10.1. A Device Indentifier URN is registered for SUEIDs. See Section 9.3.4. - $$claims-set-claims //= (sueids-label => sueids-type) + $$Claims-Set-Claims //= (sueids-label => sueids-type) sueids-type = { + tstr => ueid-type } -3.6. Hardware OEM Identification (oemid) +4.2.3. Hardware OEM Identification (oemid) This claim identifies the Original Equipment Manufacturer (OEM) of the hardware. Any of the three forms described below MAY be used at the convenience of the claim sender. The receiver of this claim MUST be able to handle all three forms. -3.6.1. Random Number Based OEMID +4.2.3.1. Random Number Based OEMID The random number based OEMID MUST always 16 bytes (128 bits). The OEM MAY create their own ID by using a cryptographic-quality random number generator. They would perform this only once in the life of the company to generate the single ID for said company. They would use that same ID in every entity they make. This uniquely identifies the OEM on a statistical basis and is large enough should there be ten billion companies. The OEM MAY also use a hash function like SHA-256 and truncate the output to 128 bits. The input to the hash should be somethings that have at least 96 bits of entropy, but preferably 128 bits of entropy. The input to the hash MAY be something whose uniqueness is managed by a central registry like a domain name. In JSON format tokens this MUST be base64url encoded. -3.6.2. IEEE Based OEMID +4.2.3.2. IEEE Based OEMID The IEEE operates a global registry for MAC addresses and company IDs. This claim uses that database to identify OEMs. The contents of the claim may be either an IEEE MA-L, MA-M, MA-S or an IEEE CID [IEEE.RA]. An MA-L, formerly known as an OUI, is a 24-bit value used as the first half of a MAC address. MA-M similarly is a 28-bit value uses as the first part of a MAC address, and MA-S, formerly known as OUI-36, a 36-bit value. Many companies already have purchased one of these. A CID is also a 24-bit value from the same space as an MA-L, but not for use as a MAC address. IEEE has published Guidelines for @@ -735,47 +777,50 @@ format. When this claim is encoded the order of bytes in the bstr are the same as the order in the Hexadecimal Representation. For example, an MA-L like "AC-DE-48" would be encoded in 3 bytes with values 0xAC, 0xDE, 0x48. This format is always 3 bytes in size in CBOR. In JSON format tokens, this MUST be base64url encoded and always 4 bytes. -3.6.3. IANA Private Enterprise Number Based OEMID +4.2.3.3. IANA Private Enterprise Number Based OEMID IANA maintains a integer-based company registry called the Private Enterprise Number (PEN) [PEN]. PENs are often used to create an OID. That is not the case here. They are used only as an integer. In CBOR this value MUST be encoded as a major type 0 integer and is typically 3 bytes. In JSON, this value MUST be encoded as a number. - oemid-pen = int + $$Claims-Set-Claims //= ( + oemid-label => oemid-pen / oemid-ieee / oemid-random + ) - oemid-ieee = bstr .size 3 + oemid-pen = int - oemid-random = bstr .size 16 + oemid-ieee = JC + oemid-ieee-cbor = bstr .size 3 + oemid-ieee-json = base64-url-text .size 4 - $$claims-set-claims //= ( - oemid-label => - oemid-random / oemid-ieee / oemid-pen - ) + oemid-random = JC + oemid-random-cbor = bstr .size 16 + oemid-random-json = base64-url-text .size 24 -3.7. Hardware Model Claim (hardware-model) +4.2.4. Hardware Model Claim (hardware-model) This claim differentiates hardware models, products and variants manufactured by a particular OEM, the one identified by OEM ID in - Section 3.6. + Section 4.2.3. This claim must be unique so as to differentiate the models and products for the OEM ID. This claim does not have to be globally unique, but it can be. A receiver of this claim MUST not assume it is globally unique. To globally identify a particular product, the receiver should concatenate the OEM ID and this claim. The granularity of the model identification is for each OEM to decide. It may be very granular, perhaps including some version information. It may be very general, perhaps only indicating top- @@ -790,151 +835,150 @@ There is no minimum length so that an OEM with a very small number of models can use a one-byte encoding. The maximum length is 32 bytes. All receivers of this claim MUST be able to receive this maximum size. The receiver of this claim MUST treat it as a completely opaque string of bytes, even if there is some apparent naming or structure. The OEM is free to alter the internal structure of these bytes as long as the claim continues to uniquely identify its models. - hardware-model-type = bytes .size (1..32) - - $$claims-set-claims //= ( + $$Claims-Set-Claims //= ( hardware-model-label => hardware-model-type ) -3.8. Hardware Version Claims (hardware-version-claims) + hardware-model-type = JC + +4.2.5. Hardware Version Claims (hardware-version-claims) The hardware version is a text string the format of which is set by each manufacturer. The structure and sorting order of this text string can be specified using the version-scheme item from CoSWID [CoSWID]. It is useful to know how to sort versions so the newer can be distinguished from the older. The hardware version can also be given by a 13-digit [EAN-13]. A new CoSWID version scheme is registered with IANA by this document in Section 9.3.3. An EAN-13 is also known as an International Article Number or most commonly as a bar code. - $$claims-set-claims //= ( + $$Claims-Set-Claims //= ( hardware-version-label => hardware-version-type ) hardware-version-type = [ version: tstr, - scheme: $version-scheme + ? scheme: $version-scheme ] -3.9. Software Name Claim +4.2.6. Software Name Claim This is a free-form text claim for the name of the software for the entity or submodule. A CoSWID manifest or other type of manifest can be used instead if this claim is to limited to correctly characterize the SW for the entity or submodule. - $$claims-set-claims //= ( sw-name-label => tstr ) + $$Claims-Set-Claims //= ( sw-name-label => tstr ) -3.10. Software Version Claim +4.2.7. Software Version Claim This makes use of the CoSWID version scheme data type to give a simple version for the software. A full CoSWID manifest or other type of manifest can be instead if this is too simple. - $$claims-set-claims //= (sw-version-label => sw-version-type) + $$Claims-Set-Claims //= (sw-version-label => sw-version-type) sw-version-type = [ - version: tstr, - scheme: $version-scheme ; As defined by CoSWID + version: tstr + ? scheme: $version-scheme ] -3.11. The Security Level Claim (security-level) +4.2.8. The Security Level Claim (security-level) This claim characterizes the entity's ability to defend against - attacks aimed at capturing the signing key, forging claims and at - forging EATs. This is by defining four security levels. + attacks aimed at capturing the signing key, forging claims and + forging EATs. - This claim describes the security environment and countermeasures - available on the entity where the attestation key resides and the - claims originate. + The intent of this claim is only to give the recipient a rough idea + of the security the entity is aiming for. This is via a simple, non- + extensible set of three levels. - 1 - Unrestricted: There is some expectation that implementor will - protect the attestation signing keys at this level. Otherwise, - the EAT provides no meaningful security assurances. + This takes a broad view of the range of defenses because EAT is + targeted at a broad range of use cases. The least secure level + involves minimal SW defenses. The most secure level involves + specialized hardware to defend against hardware-based attacks. - 2 - Restricted: Entities at this level are not general-purpose - operating environments that host features, such as app download - systems, web browsers and complex applications. It is akin to the - secure-restricted level (see below) without the security - orientation. Examples include a Wi-Fi subsystem, an IoT camera, - or sensor device. Often these can be considered more secure than - unrestricted just because they are much simpler and a smaller - attack surface, but this won't always be the case. Some - unrestricted devices may be implemented in a way that provides - poor protection of signing keys. + Only through expansive certification programs like Common Criteria + and FIDO certification is it possible to sharply define security + levels. Sharp definition of security levels is not possible here + because the IETF doesn't define and operate certification programs. + It is also not possible here because any sharp definition of security + levels would be a document larger than the EAT specification. Thus, + this definition takes the view that the security level definition + possible here is a simple, modest, rough characterization. - 3 - Secure-Restricted: Entities at this level must meet the criteria + 1 - Unrestricted: An entity is categorized as unrestricted when it + doesn't meet the criteria for any of the higher levels. This + level does not indicate there is no protection at all, just that + the entity doesn't qualify for the higher levels. + + 2 - Restricted: Entities at this level MUST meet the criteria defined in Section 4 of FIDO Allowed Restricted Operating Environments [FIDO.AROE]. Examples include TEE's and schemes using virtualization-based security. Security at this level is - aimed at defending against large-scale network/remote attacks - against the entity. + aimed at defending against large-scale network/remote attacks by + having a reduced attack surface. - 4 - Hardware: Entities at this level must include substantial - defense against physical or electrical attacks against the entity - itself. It is assumed the potential attacker has captured the - entity and can disassemble it. Examples include TPMs and Secure - Elements. + 3 - Hardware: Entities at this level are indicating they have some + countermeasures to defend against physical or electrical attacks + against the entity. Security at this level is aimed at defending + against attackers that physically capture the entity to attack it. + Examples include TPMs and Secure Elements. - The entity should claim the highest security level it achieves and no - higher. This set is not extensible so as to provide a common - interoperable description of security level to the Relying Party. If - a particular use case considers this claim to be inadequate, it can - define its own proprietary claim. It may consider including both - this claim as a coarse indication of security and its own proprietary - claim as a refined indication. + The security level claimed should be for the weakest point in the + entity, not the strongest. For example, if attestation key is + protected by hardware, but the rest of the attester is in a TEE, the + claim must be for restriced. - This claim is not intended as a replacement for a formal security - certification scheme, such as those based on FIPS 140 [FIPS-140] or - those based on Common Criteria [Common.Criteria]. See Section 3.21. + This set of three is not extensible so this remains a broad + interoperable description of security level. - $$claims-set-claims //= ( - security-level-label => - security-level-cbor-type / - security-level-json-type - ) + In particular use cases, alternate claims may be defined that give + finer grained information than this claim. - security-level-cbor-type = &( - unrestricted: 1, - restricted: 2, - secure-restricted: 3, - hardware: 4 - ) + See also the DLOAs claim in Section 4.2.15, a claim that specifically + provides information about certifications received. - security-level-json-type = - "unrestricted" / - "restricted" / - "secure-restricted" / - "hardware" + $$Claims-Set-Claims //= + ( security-level-label => security-level-type ) -3.12. Secure Boot Claim (secure-boot) + security-level-type = unrestricted / + restricted / + hardware + + unrestricted = JC< "unrestricted", 1> + restricted = JC< "restricted", 2> + hardware = JC< "hardware", 3> + +4.2.9. Secure Boot Claim (secure-boot) The value of true indicates secure boot is enabled. Secure boot is considered enabled when the firmware and operating system, are under control of the manufacturer of the entity identified in the OEMID - claim described in Section 3.6. Control by the manufacturer of the + claim described in Section 4.2.3. Control by the manufacturer of the firmware and the operating system may be by it being in ROM, being cryptographically authenticated, a combination of the two or similar. - $$claims-set-claims //= (secure-boot-label => bool) + $$Claims-Set-Claims //= (secure-boot-label => bool) -3.13. Debug Status Claim (debug-status) +4.2.10. Debug Status Claim (debug-status) This applies to entity-wide or submodule-wide debug facilities of the entity like JTAG and diagnostic hardware built into chips. It applies to any software debug facilities related to root, operating system or privileged software that allow system-wide memory inspection, tracing or modification of non-system software like user mode applications. This characterization assumes that debug facilities can be enabled and disabled in a dynamic way or be disabled in some permanent way @@ -973,264 +1017,142 @@ the description of the states refers to that, not to any aggregation or inheritance. The architecture of some chips or devices may be such that a debug facility operates for the whole chip or device. If the EAT for such a chip includes submodules, then each submodule should independently report the status of the whole-chip or whole-device debug facility. This is the only way the receiver can know the debug status of the submodules since there is no inheritance. -3.13.1. Enabled +4.2.10.1. Enabled If any debug facility, even manufacturer hardware diagnostics, is currently enabled, then this level must be indicated. -3.13.2. Disabled +4.2.10.2. Disabled This level indicates all debug facilities are currently disabled. It may be possible to enable them in the future. It may also be that they were enabled in the past, but they are currently disabled. -3.13.3. Disabled Since Boot +4.2.10.3. Disabled Since Boot This level indicates all debug facilities are currently disabled and have been so since the entity booted/started. -3.13.4. Disabled Permanently +4.2.10.4. Disabled Permanently This level indicates all non-manufacturer facilities are permanently disabled such that no end user or developer can enable them. Only the manufacturer indicated in the OEMID claim can enable them. This also indicates that all debug facilities are currently disabled and have been so since boot/start. -3.13.5. Disabled Fully and Permanently +4.2.10.5. Disabled Fully and Permanently This level indicates that all debug facilities for the entity are permanently disabled. - $$claims-set-claims //= ( - debug-status-label => - debug-status-cbor-type / debug-status-json-type - ) - - debug-status-cbor-type = &( - enabled: 0, - disabled: 1, - disabled-since-boot: 2, - disabled-permanently: 3, - disabled-fully-and-permanently: 4 - ) - - debug-status-json-type = - "enabled" / - "disabled" / - "disabled-since-boot" / - "disabled-permanently" / - "disabled-fully-and-permanently" - -3.14. Including Keys - - An EAT may include a cryptographic key such as a public key. The - signing of the EAT binds the key to all the other claims in the - token. - - The purpose for inclusion of the key may vary by use case. For - example, the key may be included as part of an IoT device onboarding - protocol. When the FIDO protocol includes a public key in its - attestation message, the key represents the binding of a user, device - and Relying Party. This document describes how claims containing - keys should be defined for the various use cases. It does not define - specific claims for specific use cases. - - Keys in CBOR format tokens SHOULD be the COSE_Key format [RFC8152] - and keys in JSON format tokens SHOULD be the JSON Web Key format - [RFC7517]. These two formats support many common key types. Their - use avoids the need to decode other serialization formats. These two - formats can be extended to support further key types through their - IANA registries. + $$Claims-Set-Claims //= ( debug-status-label => debug-status-type ) - The general confirmation claim format [RFC8747], [RFC7800] may also - be used. It provides key encryption. It also allows for inclusion - by reference through a key ID. The confirmation claim format may - employed in the definition of some new claim for a a particular use - case. + debug-status-type = ds-enabled / + disabled / + disabled-since-boot / + disabled-permanently / + disabled-fully-and-permanently - When the actual confirmation claim is included in an EAT, this - document associates no use case semantics other than proof of - possession. Different EAT use cases may choose to associate further - semantics. The key in the confirmation claim MUST be protected in - the same way as the key used to sign the EAT. That is, the same, - equivalent or better hardware defenses, access controls, key - generation and such must be used. + ds-enabled = JC< "enabled", 0 > + disabled = JC< "disabled", 1 > + disabled-since-boot = JC< "disabled-since-boot", 2 > + disabled-permanently = JC< "disabled-permanently", 3 > + disabled-fully-and-permanently = JC< "disabled-fully-and-permanently", + 4 > -3.15. The Location Claim (location) +4.2.11. The Location Claim (location) The location claim gives the location of the entity from which the attestation originates. It is derived from the W3C Geolocation API [W3C.GeoLoc]. The latitude, longitude, altitude and accuracy must conform to [WGS84]. The altitude is in meters above the [WGS84] ellipsoid. The two accuracy values are positive numbers in meters. The heading is in degrees relative to true north. If the entity is stationary, the heading is NaN (floating-point not-a-number). The speed is the horizontal component of the entity velocity in meters per second. - When encoding floating-point numbers half-precision SHOULD NOT be - used. They usually do not provide enough precision for a geographic - location. - The location may have been cached for a period of time before token creation. For example, it might have been minutes or hours or more since the last contact with a GPS satellite. Either the timestamp or age data item can be used to quantify the cached period. The timestamp data item is preferred as it a non-relative time. The age data item can be used when the entity doesn't know what time it is either because it doesn't have a clock or it isn't set. The entity MUST still have a "ticker" that can measure a time interval. The age is the interval between acquisition of the location data and token creation. See location-related privacy considerations in Section 10.2. - $$claims-set-claims //= (location-label => location-type) + $$Claims-Set-Claims //= (location-label => location-type) location-type = { latitude => number, longitude => number, ? altitude => number, ? accuracy => number, ? altitude-accuracy => number, ? heading => number, ? speed => number, ? timestamp => ~time-int, ? age => uint } - latitude = 1 / "latitude" - longitude = 2 / "longitude" - altitude = 3 / "altitude" - accuracy = 4 / "accuracy" - altitude-accuracy = 5 / "altitude-accuracy" - heading = 6 / "heading" - speed = 7 / "speed" - timestamp = 8 / "timestamp" - age = 9 / "age" + latitude = JC< "latitude", 1 > + longitude = JC< "longitude", 2 > + altitude = JC< "altitude", 3 > + accuracy = JC< "accuracy", 4 > + altitude-accuracy = JC< "altitude-accuracy", 5 > + heading = JC< "heading", 6 > + speed = JC< "speed", 7 > + timestamp = JC< "timestamp", 8 > + age = JC< "age", 9 > -3.16. The Uptime Claim (uptime) +4.2.12. The Uptime Claim (uptime) The "uptime" claim MUST contain a value that represents the number of seconds that have elapsed since the entity or submod was last booted. - $$claims-set-claims //= (uptime-label => uint) + $$Claims-Set-Claims //= (uptime-label => uint) -3.17. The Boot Odometer Claim (odometer) +4.2.13. The Boot Odometer Claim (odometer) The "odometer" claim contains a value that represents the number of times the entity or submod has been booted. Support for this claim requires a persistent storage on the device. - $$claims-set-claims //= (odometer-label => uint) + $$Claims-Set-Claims //= (odometer-label => uint) -3.18. The Boot Seed Claim (boot-seed) +4.2.14. The Boot Seed Claim (boot-seed) The Boot Seed claim MUST contain a random value created at system boot time that will allow differentiation of reports from different boot sessions. This value is usually public. It is not a secret and MUST NOT be used for any purpose that a secret seed is needed, such as seeding a random number generator. - $$claims-set-claims //= (boot-seed-label => bytes) - -3.19. The Intended Use Claim (intended-use) - - EAT's may be used in the context of several different applications. - The intended-use claim provides an indication to an EAT consumer - about the intended usage of the token. This claim can be used as a - way for an application using EAT to internally distinguish between - different ways it uses EAT. - - 1 - Generic: Generic attestation describes an application where the - EAT consumer requires the most up-to-date security assessment of - the attesting entity. It is expected that this is the most - commonly-used application of EAT. - - 2- Registration: Entities that are registering for a new service may - be expected to provide an attestation as part of the registration - process. This intended-use setting indicates that the attestation - is not intended for any use but registration. - - 3 - Provisioning: Entities may be provisioned with different values - or settings by an EAT consumer. Examples include key material or - device management trees. The consumer may require an EAT to - assess entity security state of the entity prior to provisioning. - - 4 - Certificate Issuance Certification Authorities (CA's) may - require attestations prior to the issuance of certificates related - to keypairs hosted at the entity. An EAT may be used as part of - the certificate signing request (CSR). - - 5 - Proof-of-Possession: An EAT consumer may require an attestation - as part of an accompanying proof-of-possession (PoP) application. - More precisely, a PoP transaction is intended to provide to the - recipient cryptographically-verifiable proof that the sender has - possession of a key. This kind of attestation may be necceesary - to verify the security state of the entity storing the private key - used in a PoP application. - - $$claims-set-claims //= ( - intended-use-label => - intended-use-cbor-type / intended-use-json-type - ) - - intended-use-cbor-type = &( - generic: 1, - registration: 2, - provisioning: 3, - csr: 4, - pop: 5 - ) - - intended-use-json-type = - "generic" / - "registration" / - "provisioning" / - "csr" / - "pop" - -3.20. The Profile Claim (profile) - - See Section 7 for the detailed description of a profile. - - A profile is identified by either a URL or an OID. Typically, the - URI will reference a document describing the profile. An OID is just - a unique identifier for the profile. It may exist anywhere in the - OID tree. There is no requirement that the named document be - publicly accessible. The primary purpose of the profile claim is to - uniquely identify the profile even if it is a private profile. - - The OID is always absolute and never relative. In CBOR tokens, the - OID MUST be encoded according to [RFC9090] and the URI according to - [RFC8949]. Both are unwrapped and thus not CBOR tags. In JSON - tokens, the OID is a string of the form "X.X.X", and a URI is a - normal URI string. - - Note that this is named "eat_profile" for JWT and is distinct from - the already registered "profile" claim in the JWT claims registry. - - $$claims-set-claims //= (profile-label => ~uri / ~oid) + $$Claims-Set-Claims //= (boot-seed-label => binary-data) -3.21. The DLOA (Digital Letter or Approval) Claim (dloas) +4.2.15. The DLOA (Digital Letter of Approval) Claim (dloas) A DLOA (Digital Letter of Approval) [DLOA] is an XML document that describes a certification that an entity has received. Examples of certifications represented by a DLOA include those issued by Global Platform and those based on Common Criteria. The DLOA is unspecific to any particular certification type or those issued by any particular organization. This claim is typically issued by a Verifier, not an Attester. When this claim is issued by a Verifier, it MUST be because the entity has @@ -1245,397 +1167,365 @@ for fetching the DLOA from the particular registrar. This claim MUST be encoded as an array with either two or three elements. The first element MUST be the URI for the registrar. The second element MUST be a platform label indicating which platform was certified. If the DLOA applies to an application, then the third element is added which MUST be an application label. The method of constructing the registrar URI, platform label and possibly application label is specified in [DLOA]. - $$claims-set-claims //= ( + $$Claims-Set-Claims //= ( dloas-label => [ + dloa-type ] ) dloa-type = [ - dloa_registrar: ~uri + dloa_registrar: general-uri dloa_platform_label: text ? dloa_application_label: text ] -3.22. The Software Manifests Claim (manifests) +4.2.16. The Software Manifests Claim (manifests) This claim contains descriptions of software present on the entity. These manifests are installed on the entity when the software is installed or are created as part of the installation process. Installation is anything that adds software to the entity, possibly factory installation, the user installing elective applications and so on. The defining characteristic is they are created by the software manufacturer. The purpose of these claims in an EAT is to relay them without modification to the Verifier and possibly to the Relying Party. Some manifests may be signed by their software manufacturer before they are put into this EAT claim. When such manifests are put into this claim, the manufacturer's signature SHOULD be included. For example, the manifest might be a CoSWID signed by the software manufacturer, in which case the full signed CoSWID should be put in this claim. This claim allows multiple formats for the manifest. For example, the manifest may be a CBOR-format CoSWID, an XML-format SWID or - other. Identification of the type of manifest is always by a CBOR - tag. In many cases, for examples CoSWID, a tag will already be - registered with IANA. If not, a tag MUST be registered. It can be - in the first-come-first-served space which has minimal requirements - for registration. - - The claim is an array of one or more manifests. To facilitate hand - off of the manifest to a decoding library, each manifest is contained - in a byte string. This occurs for CBOR-format manifests as well as - non-CBOR format manifests. + other. Identification of the type of manifest is always by a CoAP + Content-Format integer [RFC7252]. If there is no CoAP identifier + registered for the manifest format, one should be registered, perhaps + in the experimental or first-come-first-served range. - If a particular manifest type uses CBOR encoding, then the item in - the array for it MUST be a byte string that contains a CBOR tag. The - EAT decoder must decode the byte string and then the CBOR within it - to find the tag number to identify the type of manifest. The - contents of the byte string is then handed to the particular manifest - processor for that type of manifest. CoSWID and SUIT manifest are - examples of this. + This claim MUST be an array of one or more manifests. Each manifest + in the claim MUST be an array of two. The first item in the array of + two MUST be an integer CoAP Content-Format identifier. The second + item is MUST be the actual manifest. - If a particular manifest type does not use CBOR encoding, then the - item in the array for it MUST be a CBOR tag that contains a byte - string. The EAT decoder uses the tag to identify the processor for - that type of manifest. The contents of the tag, the byte string, are - handed to the manifest processor. Note that a byte string is used to - contain the manifest whether it is a text based format or not. An - example of this is an XML format ISO/IEC 19770 SWID. + In CBOR-encoded EATs the manifest, whatever format it is, MUST be + placed in a byte string. - It is not possible to describe the above requirements in CDDL, so the - type for an individual manifest is any in the CDDL below. The above - text sets the encoding requirement. + In JSON-format tokens the manifest, whatever format it is, MUST be + placed in a text string. When a non-text format manifest like a + CBOR-encoded CoSWID is put in a JSON-encoded token, the manifest MUST + be base-64 encoded. This claim allows for multiple manifests in one token since multiple software packages are likely to be present. The multiple manifests - MAY be of multiple formats. In some cases EAT submodules may be used - instead of the array structure in this claim for multiple manifests. + MAY be of different formats. In some cases EAT submodules may be + used instead of the array structure in this claim for multiple + manifests. When the [CoSWID] format is used, it MUST be a payload CoSWID, not an evidence CoSWID. - $$claims-set-claims //= ( + $$Claims-Set-Claims //= ( manifests-label => manifests-type ) - manifests-type = [+ $$manifest-formats] + manifests-type = [+ manifest-format] - coswid-that-is-a-cbor-tag-xx = tagged-coswid + manifest-format = [ + content-type: uint, + content-format: JC< $$manifest-body-json, + $$manifest-body-cbor > + ] - $$manifest-formats /= bytes .cbor coswid-that-is-a-cbor-tag-xx + $$manifest-body-cbor /= bytes .cbor untagged-coswid + $$manifest-body-json /= base64-url-text -3.23. The Software Evidence Claim (swevidence) + $$manifest-body-cbor /= bytes .cbor SUIT_Envelope + $$manifest-body-json /= base64-url-text + + suit-directive-process-dependency = 19 + +4.2.17. The Software Evidence Claim (swevidence) This claim contains descriptions, lists, evidence or measurements of the software that exists on the entity. The defining characteristic of this claim is that its contents are created by processes on the entity that inventory, measure or otherwise characterize the software on the entity. The contents of this claim do not originate from the software manufacturer. - This claim uses the same mechanism for identification of the type of - the swevidence as is used for the type of the manifest in the - manifests claim. It also uses the same byte string based mechanism - for containing the claim and easing the hand off to a processing - library. See the discussion above in the manifests claim. + This claim can be a [CoSWID]. When the CoSWID format is used, it + MUST be evidence CoSWIDs, not payload CoSWIDS. - When the [CoSWID] format is used, it MUST be evidence CoSWIDs, not - payload CoSWIDS. + Formats other than CoSWID can be used. The identification of format + is by CoAP Content Format, the same as the manifests claim in + Section 4.2.16. - $$claims-set-claims //= ( + $$Claims-Set-Claims //= ( swevidence-label => swevidence-type ) - swevidence-type = [+ $$swevidence-formats] + swevidence-type = [+ swevidence-format] - coswid-that-is-a-cbor-tag = tagged-coswid - $$swevidence-formats /= bytes .cbor coswid-that-is-a-cbor-tag + swevidence-format = [ + content-type: uint, + content-format: JC< $$swevidence-body-json, + $$swevidence-body-cbor > + ] -3.24. The SW Measurement Results Claim (swresults) + $$swevidence-body-cbor /= bytes .cbor untagged-coswid + $$swevidence-body-json /= base64-url-text - This claims reports the outcome of the comparison of a measurement on - some software to the expected Reference Values. It may report a - successful comparison, failed comparison or other. +4.2.18. The Measurement Results Claim (measurement-results) + + This claim is a general-purpose structure for reporting comparison of + measurements to expected Reference Values. This claim provides a + simple standard way to report the result of a comparison as success, + failure, fail to run, ... + + It is the nature of measurement systems that they are specific to the + operating system, software and hardware of the entity that is being + measured. It is not possible to standardize what is measured and how + it is measured across platforms, OS's, software and hardware. The + recipient must obtain the information about what was measured and + what it indicates for the characterization of the security of the + entity from the provider of the measurement system. What this claim + provides is a standard way to report basic success or failure of the + measurement. In some use cases it is valuable to know if + measurements succeeded or failed in a general way even if the details + of what was measured is not characterized. This claim MAY be generated by the Verifier and sent to the Relying Party. For example, it could be the results of the Verifier - comparing the contents of the swevidence claim to Reference Values. + comparing the contents of the swevidence claim, {#swevidence}, to + Reference Values. This claim MAY also be generated on the entity if the entity has the - ability for one subsystem to measure another subsystem. For example, - a TEE might have the ability to measure the software of the rich OS - and may have the Reference Values for the rich OS. - - Within an attestation target or submodule, multiple results can be - reported. For example, it may be desirable to report the results for - the kernel and each individual application separately. - - For each software objective, the following can be reported. TODO: - defined objective - -3.24.1. Scheme - - This is the free-form text name of the verification system or scheme - that performed the verification. There is no official registry of - schemes or systems. It may be the name of a commercial product or - such. - -3.24.2. Objective - - This roughly characterizes the coverage of the software measurement - software. This corresponds to the attestation target or the - submodule. If all of the indicated target is not covered, the - measurement must indicate partial. - - 1 - all: Indicates all the software has been verified, for example, - all the software in the attestation target or the submodule - - 2 - firmware: Indicates all of and only the firmware - - 3 - kernel: Refers to all of the most-privileged software, for - example the Linux kernel - - 4 - privileged: Refers to all of the software used by the root, - system or administrative account - - 5 - system-libs: Refers to all of the system libraries that are - broadly shared and used by applications and such + ability for one subsystem to measure and evaluate another subsystem. + For example, a TEE might have the ability to measure the software of + the rich OS and may have the Reference Values for the rich OS. - 6 - partial: Some other partial set of the software + Within an entity, attestation target or submodule, multiple results + can be reported. For example, it may be desirable to report the + results for measurements of the file system, chip configuration, + installed software, running software and so on. -3.24.3. Results + Note that this claim is not for reporting the overall result of a + Verifier. It is solely for reporting the result of comparison to + reference values. - This describes the result of the measurement and also the comparison - to Reference Values. + An individual measurement result is an array of two, an identifier of + the measurement and an enumerated type that is the result. The range + and values of the measurement identifier varies from one measurement + scheme to another. - 1 - verification-not-run: Indicates that no attempt was made to run - the verification + Each individual measurement result is part of a group that may + contain many individual results. Each group has a text string that + names it, typically the name of the measurement scheme or system. - 2 - verification-indeterminite: The verification was attempted, but - it did not produce a result; perhaps it ran out of memory, the - battery died or such + The claim itself consists of one or more groups. - 3 - verification-failed: The verification ran to completion, the - comparison was completed and did not compare correctly to the - Reference Values + The values for the results enumerated type are as follows: - 4 - fully-verified: The verification ran to completion and all - measurements compared correctly to Reference Values + 1 - comparison successful Indicates successful comparison to + reference values. - 5 - partially-verified: The verification ran to completion and some, - but not all, measurements compared correctly to Reference Values + 2 - comparison fail The comparison was completed and did not compare + correctly to the Reference Values. -3.24.4. Objective Name + 3 - comparison not run The comparison was not run. This includes + error conditions such as running out of memory. - This is a free-form text string that describes the objective. For - example, "Linux kernel" or "Facebook App" - $$claims-set-claims //= (swresults-label => [ + swresult-type ]) + 4 - measurement absent The particular measurement was not available + for comparison. - verification-result-cbor-type = &( - verification-not-run: 1, - verification-indeterminate: 2, - verification-failed: 3, - fully-verified: 4, - partially-verified: 5, - ) + $$Claims-Set-Claims //= ( + measurement-results-label => + [ + measurement-results-group ] ) - verification-result-json-type = - "verification-not-run" / - "verification-indeterminate" / - "verification-failed" / - "fully-verified" / - "partially-verified" + measurement-results-group = [ + measurement-system: tstr, + measruement-results: [ + individual-result ] + ] - verification-objective-cbor-type = &( - all: 1, - firmware: 2, - kernel: 3, - privileged: 4, - system-libs: 5, - partial: 6, - ) + individual-result = [ + results-id: tstr / binary-data, + result: result-type, + ] - verification-objective-json-type = - "all" / - "firmware" / - "kernel" / - "privileged" / - "system-libs" / - "partial" + result-type = comparison-successful / + comparison-fail / + comparison-not-run / + measurement-absent - swresult-type = [ - verification-system: tstr, - objective: verification-objective-cbor-type / - verification-objective-json-type, - result: verification-result-cbor-type / - verification-result-json-type, - ? objective-name: tstr - ] + comparison-successful = JC< "success", 1 > + comparison-fail = JC< "fail", 2 > + comparison-not-run = JC< "not-run", 3 > + measurement-absent = JC< "absent", 4 > -3.25. Submodules (submods) +4.2.19. Submodules (submods) Some devices are complex, having many subsystems. A mobile phone is a good example. It may have several connectivity subsystems for communications (e.g., Wi-Fi and cellular). It may have subsystems for low-power audio and video playback. It may have multiple security-oriented subsystems like a TEE and a Secure Element. The claims for a subsystem can be grouped together in a submodule or submod. The submods are in a single map/object, one entry per submodule. There is only one submods map/object in a token. It is identified by its specific label. It is a peer to other claims, but it is not called a claim because it is a container for a claims set rather than an individual claim. This submods part of a token allows what might be called recursion. It allows claims sets inside of claims sets inside of claims sets... -3.25.1. Submodule Types +4.2.19.1. Submodule Types The following sections define the three types of submodules: o A submodule Claims-Set o A nested token, which can be any valid EAT token, CBOR or JSON o The digest of a detached Claims-Set -3.25.1.1. Submodule Claims-Set + $$Claims-Set-Claims //= (submods-label => { + text => Submodule }) + + Submodule = Claims-Set / Nested-Token / Detached-Submodule-Digest + +4.2.19.1.1. Submodule Claims-Set This is a subordinate Claims-Set containing claims about the submodule. - The submodule claims-set is produced by the same Attester as the + The submodule Claims-Set is produced by the same Attester as the surrounding token. It is secured using the same mechanism as the enclosing token (e.g., it is signed by the same attestation key). It roughly corresponds to an Attester Target Environment, as described in the RATS architecture. It may contain claims that are the same as its surrounding token or superior submodules. For example, the top-level of the token may have a UEID, a submod may have a different UEID and a further subordinate submodule may also have a UEID. The encoding of a submodule Claims-Set MUST be the same as the encoding as the token it is part of. This data type for this type of submodule is a map/object. It is identified when decoding by it's type being a map/object. -3.25.1.2. Nested Token +4.2.19.1.2. Nested Token This type of submodule is a fully formed complete token. It is typically produced by a separate Attester. It is typically used by a Composite Device as described in RATS Architecture [RATS.Architecture] In being a submodule of the surrounding token, it is cryptographically bound to the surrounding token. If it was conveyed in parallel with the surrounding token, there would be no such binding and attackers could substitute a good attestation from another device for the attestation of an errant subsystem. A nested token does not need to use the same encoding as the enclosing token. This is to allow Composite Devices to be built - without regards to the encoding supported by their Attesters. Thus a - CBOR-encoded token like a CWT or UCCS can have a JWT as a nested - token submodule and a JSON-encoded token can have a CWT or UCCS as a - nested token submodule. - - The following two sections describe how to encode and decode a nested - token. + without regards to the encoding supported by their Attesters. Thus, + a CBOR-encoded token like a CWT can have a JWT as a nested token + submodule and vice versa. -3.25.1.2.1. Surrounding EAT is CBOR-Encoded +4.2.19.1.2.1. Surrounding EAT is CBOR-Encoded This describes the encoding and decoding of CBOR or JSON-encoded tokens nested inside a CBOR-encoded token. If the nested token is CBOR-encoded, then it MUST be a CBOR tag and MUST be wrapped in a byte string. The tag identifies whether the - nested token is a CWT, a UCCS, a CBOR-encoded DEB, or some other - CBOR-format token defined in the future. A nested CBOR-encoded token - that is not a CBOR tag is NOT allowed. + nested token is a CWT, a CBOR-encoded DEB, or some other CBOR-format + token defined in the future. A nested CBOR-encoded token that is not + a CBOR tag is NOT allowed. If the nested token is JSON-encoded, then the data item MUST be a - text string. The text string MUST contain a JSON-encoded array of - two items. The first item is a string identifying the type of the - token. The second item is the JSON-encoded token. - - The string identifying the JSON-encoded token MUST be one of the - following: - - "JWT": The second item MUST be a JWT formatted according to - [RFC7519] - - "UJCS": The second item MUST be a UJCS-Message as defined in this - document. - - "DEB": The second item MUST be a JSON-encoded Detached EAT Bundle as - defined in this document. - - The definition of additional types requires a standards action. + text string containing JSON. The JSON is defined in CDDL by JSON- + Nested-Token in the next section. When decoding, if a byte string is encountered, it is known to be a nested CBOR-encoded token. The byte string wrapping is removed. The type of the token is determined by the CBOR tag. When decoding, if a text string is encountered, it is known to be a JSON-encoded token. The two-item array is decoded and tells the type of the JSON-encoded token. - Nested-Token = - tstr / ; A JSON-encoded Nested-Token (see json-nested-token.cddl) - bstr .cbor Tagged-CBOR-Token + Nested-Token = CBOR-Nested-Token -3.25.1.2.2. Surrounding EAT is JSON-Encoded + CBOR-Nested-Token = + JSON-Token-Inside-CBOR-Token / + CBOR-Token-Inside-CBOR-Token + + CBOR-Token-Inside-CBOR-Token = bstr .cbor $$EAT-CBOR-Tagged-Token + + JSON-Token-Inside-CBOR-Token = tstr + +4.2.19.1.2.2. Surrounding EAT is JSON-Encoded This describes the encoding and decoding of CBOR or JSON-encoded tokens nested inside a JSON-encoded token. - The nested token MUST be an array of two in the same format as - described in the section above. + The nested token MUST be an array of two, a text string type + indicator and the actual token. - A CBOR-encoded token nested inside a JSON-encoded MUST use the same - array of two, but with the type as follows: + The string identifying the JSON-encoded token MUST be one of the + following: - "CBOR": Some base64url-encoded CBOR that is a tag, typically a CWT, - UCCS or CBOR-encoded DEB + "JWT": The second array item MUST be a JWT formatted according to + [RFC7519] + + "CBOR": The second array item must be some base64url-encoded CBOR + that is a tag, typically a CWT or CBOR-encoded DEB + + "DEB": The second array item MUST be a JSON-encoded Detached EAT + Bundle as defined in this document. + + Additional types may be defined by a standards action. When decoding, the array of two is decoded. The first item indicates the type and encoding of the nested token. If the type string is not "CBOR", then the token is JSON-encoded and of the type indicated by the string. If the type string is "CBOR", then the token is CBOR-encoded. The base64url encoding is removed. The CBOR-encoded data is then decoded. The type of nested token is determined by the CBOR-tag. It is an error if the CBOR is not a tag. - Nested-Token = [ - type : "JWT" / "CBOR" / "UJCS" / "DEB", + Nested-Token = JSON-Nested-Token + + JSON-Nested-Token = [ + type : "JWT" / "CBOR" / "DEB", nested-token : JWT-Message / - B64URL-Tagged-CBOR-Token / - DEB-JSON-Message / - UJCS-Message + CBOR-Token-Inside-JSON-Token / + Detached-EAT-Bundle ] - B64URL-Tagged-CBOR-Token = tstr .regexp "[A-Za-z0-9_=-]+" + CBOR-Token-Inside-JSON-Token = base64-url-text -3.25.1.3. Detached Submodule Digest +4.2.19.1.3. Detached Submodule Digest This is type of submodule equivalent to a Claims-Set submodule, except the Claims-Set is conveyed separately outside of the token. This type of submodule consists of a digest made using a cryptographic hash of a Claims-Set. The Claims-Set is not included in the token. It is conveyed to the Verifier outside of the token. The submodule containing the digest is called a detached digest. The separately conveyed Claims-Set is called a detached claims set. @@ -1668,138 +1558,256 @@ two data items, an algorithm identifier and a byte string containing the digest. When decoding a CBOR format token the detached digest type is distringuished from the other types by it being an array. In CBOR the none of other submodule types are arrays. When decoding a JSON format token, a little more work is required because both the nested token and detached digest types are an array. To distinguish the nested token from the detached digest, the first - element in the array is examined. If it is "JWT", "UJCS" or "DEB", - the the submodule is a nested token. Otherwise it will contain an - algorithm identifier and is a detached digest. + element in the array is examined. If it is "JWT" or "DEB", then the + submodule is a nested token. Otherwise it will contain an algorithm + identifier and is a detached digest. A DEB, described in Section 5, may be used to convey detached claims sets and the token with their detached digests. EAT, however, doesn't require use of a DEB. Any other protocols may be used to convey detached claims sets and the token with their detached - digests. Note that since detached Claims-Sets are usually signed, - protocols conveying them must make sure they are not modified in - transit. + digests. Note that since detached Claims-Sets are signed, protocols + conveying them must make sure they are not modified in transit. -3.25.2. No Inheritance + Detached-Submodule-Digest = [ + algorithm : JC< text, int > + digest : binary-data + ] + +4.2.19.2. No Inheritance The subordinate modules do not inherit anything from the containing token. The subordinate modules must explicitly include all of their claims. This is the case even for claims like the nonce. This rule is in place for simplicity. It avoids complex inheritance rules that might vary from one type of claim to another. -3.25.3. Security Levels +4.2.19.3. Security Levels The security level of the non-token subordinate modules should always be less than or equal to that of the containing modules in the case of non-token submodules. It makes no sense for a module of lesser security to be signing claims of a module of higher security. An example of this is a TEE signing claims made by the non-TEE parts (e.g. the high-level OS) of the device. The opposite may be true for the nested tokens. They usually have their own more secure key material. An example of this is an embedded secure element. -3.25.4. Submodule Names +4.2.19.4. Submodule Names The label or name for each submodule in the submods map is a text string naming the submodule. No submodules may have the same name. -3.25.5. CDDL for submods +4.3. Claims Describing the Token - The submodule type is distinguished in the encoded bytes by its data - type, map/object for a Claims-Set, string for nested token and array - for a detached submodule. Nested tokens are byte-string wrapped when - encoded in CBOR and base64 encoded for JSON. + The claims in this section provide meta data about the token they + occur in. They do not describe the entity. - $$claims-set-claims //= (submods-label => { + text => Submodule }) + They may appear in Attestation Evidence or Attestation Results. When + these claims appear in Attestation Evidence, they SHOULD not be + passed through the Verifier into Attestation Results. - Submodule = Claims-Set / Nested-Token / Detached-Submodule-Digest +4.3.1. Token ID Claim (cti and jti) - Detached-Submodule-Digest = [ - algorithm : int / text, - digest : bstr - ] + CWT defines the "cti" claim. JWT defines the "jti" claim. These are + equivalent to each other in EAT and carry a unique token identifier + as they do in JWT and CWT. They may be used to defend against re use + of the token but are distinct from the nonce that is used by the + Relying Party to guarantee freshness and defend against replay. -4. Unprotected JWT Claims-Sets +4.3.2. Timestamp claim (iat) - This is simply the JSON equivalent of an Unprotected CWT Claims-Set - [UCCS.Draft]. + The "iat" claim defined in CWT and JWT is used to indicate the date- + of-creation of the token, the time at which the claims are collected + and the token is composed and signed. - It has no protection of its own so protections must be provided by - the protocol carrying it. These are extensively discussed in - [UCCS.Draft]. All the security discussion and security - considerations in [UCCS.Draft] apply to UJCS. + The data for some claims may be held or cached for some period of + time before the token is created. This period may be long, even + days. Examples are measurements taken at boot or a geographic + position fix taken the last time a satellite signal was received. + There are individual timestamps associated with these claims to + indicate their age is older than the "iat" timestamp. - (Note: The EAT author is open to this definition being moved into the - UCCS draft, perhaps along with the related CDDL. It is place here - for now so that the current UCCS draft plus this document are - complete. UJCS is needed for the same use cases that a UCCS is - needed. Further, JSON will commonly be used to convey Attestation - Results since JSON is common for server to server communications. - Server to server communications will often have established security - (e.g., TLS) therefore the signing and encryption from JWS and JWE are - unnecssary and burdensome). + CWT allows the use floating-point for this claim. EAT disallows the + use of floating-point. An EAT token MUST NOT contain an iat claim in + float-point format. Any recipient of a token with a floating-point + format iat claim MUST consider it an error. A 64-bit integer + representation of epoch time can represent a range of +/- 500 billion + years, so the only point of a floating-point timestamp is to have + precession greater than one second. This is not needed for EAT. + +4.3.3. The Profile Claim (profile) + + See Section 7 for the detailed description of a profile. + + A profile is identified by either a URL or an OID. Typically, the + URI will reference a document describing the profile. An OID is just + a unique identifier for the profile. It may exist anywhere in the + OID tree. There is no requirement that the named document be + publicly accessible. The primary purpose of the profile claim is to + uniquely identify the profile even if it is a private profile. + + The OID is always absolute and never relative. + + See Section 8.2.1 for OID and URI encoding. + + Note that this is named "eat_profile" for JWT and is distinct from + the already registered "profile" claim in the JWT claims registry. + + $$Claims-Set-Claims //= (profile-label => general-uri / general-oid) + +4.3.4. The Intended Use Claim (intended-use) + + EAT's may be used in the context of several different applications. + The intended-use claim provides an indication to an EAT consumer + about the intended usage of the token. This claim can be used as a + way for an application using EAT to internally distinguish between + different ways it uses EAT. + + 1 - Generic: Generic attestation describes an application where the + EAT consumer requires the most up-to-date security assessment of + the attesting entity. It is expected that this is the most + commonly-used application of EAT. + + 2- Registration: Entities that are registering for a new service may + be expected to provide an attestation as part of the registration + process. This intended-use setting indicates that the attestation + is not intended for any use but registration. + + 3 - Provisioning: Entities may be provisioned with different values + or settings by an EAT consumer. Examples include key material or + device management trees. The consumer may require an EAT to + assess entity security state of the entity prior to provisioning. + + 4 - Certificate Issuance Certification Authorities (CA's) may + require attestations prior to the issuance of certificates related + to keypairs hosted at the entity. An EAT may be used as part of + the certificate signing request (CSR). + + 5 - Proof-of-Possession: An EAT consumer may require an attestation + as part of an accompanying proof-of-possession (PoP) application. + More precisely, a PoP transaction is intended to provide to the + recipient cryptographically-verifiable proof that the sender has + possession of a key. This kind of attestation may be necceesary + to verify the security state of the entity storing the private key + used in a PoP application. + + $$Claims-Set-Claims //= ( intended-use-label => intended-use-type ) + + intended-use-type = generic / + registration / + provisioning / + csr / + pop + + generic = JC< "generic", 1 > + registration = JC< "registration", 2 > + provisioning = JC< "provisioning", 3 > + csr = JC< "csr", 4 > + pop = JC< "pop", 5 > + +4.4. Including Keys + + An EAT may include a cryptographic key such as a public key. The + signing of the EAT binds the key to all the other claims in the + token. + + The purpose for inclusion of the key may vary by use case. For + example, the key may be included as part of an IoT device onboarding + protocol. When the FIDO protocol includes a public key in its + attestation message, the key represents the binding of a user, device + and Relying Party. This document describes how claims containing + keys should be defined for the various use cases. It does not define + specific claims for specific use cases. + + Keys in CBOR format tokens SHOULD be the COSE_Key format [RFC8152] + and keys in JSON format tokens SHOULD be the JSON Web Key format + [RFC7517]. These two formats support many common key types. Their + use avoids the need to decode other serialization formats. These two + formats can be extended to support further key types through their + IANA registries. + + The general confirmation claim format [RFC8747], [RFC7800] may also + be used. It provides key encryption. It also allows for inclusion + by reference through a key ID. The confirmation claim format may + employed in the definition of some new claim for a a particular use + case. + + When the actual confirmation claim is included in an EAT, this + document associates no use case semantics other than proof of + possession. Different EAT use cases may choose to associate further + semantics. The key in the confirmation claim MUST be protected in + the same way as the key used to sign the EAT. That is, the same, + equivalent or better hardware defenses, access controls, key + generation and such must be used. 5. Detached EAT Bundles A detached EAT bundle is a structure to convey a fully-formed and signed token plus detached claims set that relate to that token. It - is a top-level EAT message like a CWT, JWT, UCCS and UJCS. It can be - used any place that CWT, JWT, UCCS or UJCS messages are used. It may - also be sent as a submodule. + is a top-level EAT message like a CWT or JWT. It can be occur any + place that CWT or JWT messages occur. It may also be sent as a + submodule. A DEB has two main parts. The first part is a full top-level token. This top-level token must have at least one submodule that is a detached digest. This top- - level token may be either CBOR or JSON-encoded. It may be a CWT, - JWT, UCCS or UJCS, but not a DEB. The same mechanism for - distinguishing the type for nested token submodules is used here. + level token may be either CBOR or JSON-encoded. It may be a CWT, or + JWT but not a DEB. It may also be some future-defined token type. + The same mechanism for distinguishing the type for nested token + submodules is used here. The second part is a map/object containing the detached Claims-Sets corresponding to the detached digests in the full token. When the DEB is CBOR-encoded, each Claims-Set is wrapped in a byte string. When the DEB is JSON-encoded, each Claims-Set is base64url encoded. All the detached Claims-Sets MUST be encoded in the same format as the DEB. No mixing of encoding formats is allowed for the Claims- Sets in a DEB. For CBOR-encoded DEBs, tag TBD602 can be used to identify it. The normal rules apply for use or non-use of a tag. When it is sent as a submodule, it is always sent as a tag to distinguish it from the other types of nested tokens. The digests of the detached claims sets are associated with detached - claims-sets by label/name. It is up to the constructor of the + Claims-Sets by label/name. It is up to the constructor of the detached EAT bundle to ensure the names uniquely identify the detached claims sets. Since the names are used only in the detached EAT bundle, they can be very short, perhaps one byte. + DEB-Messages = DEB-Tagged-Message / DEB-Untagged-Message + + DEB-Tagged-Message = #6.TBD(DEB-Untagged-Message) + DEB-Untagged-Message = Detached-EAT-Bundle + Detached-EAT-Bundle = [ main-token : Nested-Token, detached-claims-sets: { - + tstr => cbor-wrapped-claims-set / json-wrapped-claims-set + + tstr => JC } ] - json-wrapped-claims-set = tstr .regexp "[A-Za-z0-9_=-]+" + json-wrapped-claims-set = base64-url-text cbor-wrapped-claims-set = bstr .cbor Claims-Set 6. Endorsements and Verification Keys The Verifier must possess the correct key when it performs the cryptographic part of an EAT verification (e.g., verifying the COSE/ JOSE signature). This section describes several ways to identify the verification key. There is not one standard method. @@ -1909,40 +1917,40 @@ 7. Profiles This EAT specification does not gaurantee that implementations of it will interoperate. The variability in this specification is necessary to accommodate the widely varying use cases. An EAT profile narrows the specification for a specific use case. An ideal EAT profile will guarantee interoperability. The profile can be named in the token using the profile claim - described in Section 3.20. + described in Section 4.3.3. A profile can apply to Attestation Evidence or to Attestation Results or both. 7.1. Format of a Profile Document A profile document doesn't have to be in any particular format. It may be simple text, something more formal or a combination. In some cases CDDL may be created that replaces CDDL in this or other document to express some profile requirements. For example, to require the altitude data item in the location claim, CDDL can be written that replicates the location claim with the altitude no longer optional. 7.2. List of Profile Issues - The following is a list of EAT, CWT, UCCS, JWS, UJCS, COSE, JOSE and - CBOR options that a profile should address. + The following is a list of EAT, CWT, JWS, COSE, JOSE and CBOR options + that a profile should address. 7.2.1. Use of JSON, CBOR or both The profile should indicate whether the token format should be CBOR, JSON, both or even some other encoding. If some other encoding, a specification for how the CDDL described here is serialized in that encoding is necessary. This should be addressed for the top-level token and for any nested tokens. For example, a profile might require all nested tokens to be @@ -1972,25 +1980,24 @@ 7.2.4. CBOR Preferred Serialization The profile should indicate whether encoders must use preferred serialization. The profile should indicate whether decoders must accept non-preferred serialization. 7.2.5. COSE/JOSE Protection COSE and JOSE have several options for signed, MACed and encrypted - messages. EAT/CWT has the option to have no protection using UCCS - and JOSE has a NULL protection option. It is possible to implement - no protection, sign only, MAC only, sign then encrypt and so on. All - combinations allowed by COSE, JOSE, JWT, CWT, UCCS and UJCS are - allowed by EAT. + messages. JWT may use the JOSE NULL protection option. It is + possible to implement no protection, sign only, MAC only, sign then + encrypt and so on. All combinations allowed by COSE, JOSE, JWT, and + CWT are allowed by EAT. The profile should list the protections that must be supported by all decoders implementing the profile. The encoders them must implement a subset of what is listed for the decoders, perhaps only one. Implementations may choose to sign or MAC before encryption so that the implementation layer doing the signing or MACing can be the smallest. It is often easier to make smaller implementations more secure, perhaps even implementing in solely in hardware. The key material for a signature or MAC is a private key, while for @@ -2050,22 +2057,21 @@ 7.2.14. Refined Claim Definition The profile may lock down optional aspects of individual claims. For example, it may require altitude in the location claim, or it may require that HW Versions always be described using EAN-13. 7.2.15. CBOR Tags The profile should specify whether the token should be a CWT Tag or - not. Similarly, the profile should specify whether the token should - be a UCCS tag or not. + not. When COSE protection is used, the profile should specify whether COSE tags are used or not. Note that RFC 8392 requires COSE tags be used in a CWT tag. Often a tag is unncessary because the surrounding or carrying protocol identifies the object as an EAT. 7.2.16. Manifests and Software Evidence Claims @@ -2080,63 +2086,73 @@ how to encode the CDDL in CBOR or JSON. Since CBOR can express some things that JSON can't (e.g., tags) or that are expressed differently (e.g., labels) there is some CDDL that is specific to the encoding format. 8.1. Claims-Set and CDDL for CWT and JWT CDDL was not used to define CWT or JWT. It was not available at the time. - This document defines CDDL for both CWT and JWT as well as UCCS. - This document does not change the encoding or semantics of anything - in a CWT or JWT. + This document defines CDDL for both CWT and JWT. This document does + not change the encoding or semantics of anything in a CWT or JWT. - A Claims-Set is the central data structure for EAT, CWT, JWT and - UCCS. It holds all the claims and is the structure that is secured - by signing or other means. It is not possible to define EAT, CWT, - JWT or UCCS in CDDL without it. The CDDL definition of Claims-Set - here is applicable to EAT, CWT, JWT and UCCS. + A Claims-Set is the central data structure for EAT, CWT and JWT. It + holds all the claims and is the structure that is secured by signing + or other means. It is not possible to define EAT, CWT, or JWT in + CDDL without it. The CDDL definition of Claims-Set here is + applicable to EAT, CWT and JWT. This document specifies how to encode a Claims-Set in CBOR or JSON. With the exception of nested tokens and some other externally defined structures (e.g., SWIDs) an entire Claims-Set must be in encoded in either CBOR or JSON, never a mixture. CDDL for the seven claims defined by [RFC8392] and [RFC7519] is included here. 8.2. Encoding Data Types This makes use of the types defined in [RFC8610] Appendix D, Standard Prelude. 8.2.1. Common Data Types time-int is identical to the epoch-based time, but disallows floating-point representation. + The OID encoding from [RFC9090] is used without the tag number in + CBOR-encoded tokens. In JSON tokens OIDs are a text string in the + common form of "nn.nn.nn...". + Unless expliclity indicated, URIs are not the URI tag defined in [RFC8949]. They are just text strings that contain a URI. - string-or-uri = tstr - time-int = #6.1(int) + binary-data = JC< base64-url-text, bstr> + + base64-url-text = tstr .regexp "[A-Za-z0-9_=-]+" + + general-oid = JC< json-oid, ~oid > + + json-oid = tstr .regexp "[0-9\.]+" + + general-uri = JC< text, ~uri > + 8.2.2. JSON Interoperability JSON should be encoded per [RFC8610] Appendix E. In addition, the following CDDL types are encoded in JSON as follows: o bstr - must be base64url encoded - o time - must be encoded as NumericDate as described section 2 of [RFC7519]. o string-or-uri - must be encoded as StringOrURI as described section 2 of [RFC7519]. o uri - must be a URI [RFC3986]. o oid - encoded as a string using the well established dotted- decimal notation (e.g., the text "1.2.250.1"). @@ -2134,20 +2150,24 @@ [RFC7519]. o string-or-uri - must be encoded as StringOrURI as described section 2 of [RFC7519]. o uri - must be a URI [RFC3986]. o oid - encoded as a string using the well established dotted- decimal notation (e.g., the text "1.2.250.1"). + The CDDL generic "JC< >" is used in most places where there is a + variance between CBOR and JSON. The first argument is the CDDL for + JSON and the second is CDDL for CBOR. + 8.2.3. Labels Map labels, including Claims-Keys and Claim-Names, and enumerated- type values are always integers when encoding in CBOR and strings when encoding in JSON. There is an exception to this for naming submodules and detached claims sets in a DEB. These are strings in CBOR. The CDDL in most cases gives both the integer label and the string label as it is not convenient to have conditional CDDL for such. @@ -2192,360 +2212,330 @@ o Sorting of maps by key is not required. The EAT decoder must not rely on sorting. o Deterministic encoding described in Section 4.2 of [RFC8949] is not required. o Basic validity described in section 5.3.1 of [RFC8949] must be followed. The EAT encoder must not send duplicate map keys/labels or invalid UTF-8 strings. -8.4. Collected Common CDDL +8.4. Collected CDDL -Claims-Set = { - * $$claims-set-claims, - * Claim-Label .feature "extended-label" => any -} +8.4.1. Payload CDDL -Claim-Label = int / text -string-or-uri = tstr + This CDDL defines all the EAT Claims that are added to the main + definition of a Claim-Set in Appendix D. Claims-Set is the payload + for CWT, JWT and potentially other token types. This is for both + CBOR and JSON. When there is variation between CBOR and JSON, the + JC<> CDDL generic defined in Appendix D. + + This CDDL uses, but doesn't define Nested-Token because its + definition varies between CBOR and JSON and the JC<> generic can't be + used to define it. Nested-Token is the one place that that a CBOR + token can be nested inside a JSON token and vice versa. Nested-Token + is defined in the following sections. time-int = #6.1(int) -$$claims-set-claims //= (iss-label => text) -$$claims-set-claims //= (sub-label => text) -$$claims-set-claims //= (aud-label => text) -$$claims-set-claims //= (exp-label => ~time) -$$claims-set-claims //= (nbf-label => ~time) -$$claims-set-claims //= (iat-label => ~time) -$$claims-set-claims //= + binary-data = JC< base64-url-text, bstr> + + base64-url-text = tstr .regexp "[A-Za-z0-9_=-]+" + + general-oid = JC< json-oid, ~oid > + json-oid = tstr .regexp "[0-9\.]+" + + general-uri = JC< text, ~uri > + + $$Claims-Set-Claims //= (nonce-label => nonce-type / [ 2* nonce-type ]) -nonce-type = bstr .size (8..64) -$$claims-set-claims //= (ueid-label => ueid-type) + nonce-type = JC< tstr .size (10..74), bstr .size (8..64)> -ueid-type = bstr .size (7..33) -$$claims-set-claims //= (sueids-label => sueids-type) + $$Claims-Set-Claims //= (ueid-label => ueid-type) + + ueid-type = JC + + $$Claims-Set-Claims //= (sueids-label => sueids-type) sueids-type = { + tstr => ueid-type } + + $$Claims-Set-Claims //= ( + oemid-label => oemid-pen / oemid-ieee / oemid-random + ) + oemid-pen = int -oemid-ieee = bstr .size 3 -oemid-random = bstr .size 16 + oemid-ieee = JC + oemid-ieee-cbor = bstr .size 3 + oemid-ieee-json = base64-url-text .size 4 -$$claims-set-claims //= ( - oemid-label => - oemid-random / oemid-ieee / oemid-pen -) -$$claims-set-claims //= ( + oemid-random = JC + oemid-random-cbor = bstr .size 16 + oemid-random-json = base64-url-text .size 24 + + $$Claims-Set-Claims //= ( hardware-version-label => hardware-version-type ) hardware-version-type = [ version: tstr, - scheme: $version-scheme + ? scheme: $version-scheme ] -hardware-model-type = bytes .size (1..32) -$$claims-set-claims //= ( + $$Claims-Set-Claims //= ( hardware-model-label => hardware-model-type ) -$$claims-set-claims //= ( sw-name-label => tstr ) -$$claims-set-claims //= (sw-version-label => sw-version-type) + hardware-model-type = JC + + $$Claims-Set-Claims //= ( sw-name-label => tstr ) + + $$Claims-Set-Claims //= (sw-version-label => sw-version-type) sw-version-type = [ - version: tstr, - scheme: $version-scheme ; As defined by CoSWID + version: tstr + ? scheme: $version-scheme ] -$$claims-set-claims //= ( - security-level-label => - security-level-cbor-type / - security-level-json-type -) -security-level-cbor-type = &( - unrestricted: 1, - restricted: 2, - secure-restricted: 3, - hardware: 4 -) + $$Claims-Set-Claims //= + ( security-level-label => security-level-type ) -security-level-json-type = - "unrestricted" / - "restricted" / - "secure-restricted" / - "hardware" -$$claims-set-claims //= (secure-boot-label => bool) -$$claims-set-claims //= ( - debug-status-label => - debug-status-cbor-type / debug-status-json-type -) + security-level-type = unrestricted / + restricted / + hardware -debug-status-cbor-type = &( - enabled: 0, - disabled: 1, - disabled-since-boot: 2, - disabled-permanently: 3, - disabled-fully-and-permanently: 4 -) + unrestricted = JC< "unrestricted", 1> + restricted = JC< "restricted", 2> + hardware = JC< "hardware", 3> -debug-status-json-type = - "enabled" / - "disabled" / - "disabled-since-boot" / - "disabled-permanently" / - "disabled-fully-and-permanently" -$$claims-set-claims //= (location-label => location-type) + $$Claims-Set-Claims //= (secure-boot-label => bool) + + $$Claims-Set-Claims //= ( debug-status-label => debug-status-type ) + + debug-status-type = ds-enabled / + disabled / + disabled-since-boot / + disabled-permanently / + disabled-fully-and-permanently + + ds-enabled = JC< "enabled", 0 > + disabled = JC< "disabled", 1 > + disabled-since-boot = JC< "disabled-since-boot", 2 > + disabled-permanently = JC< "disabled-permanently", 3 > + disabled-fully-and-permanently = JC< "disabled-fully-and-permanently", + 4 > + + $$Claims-Set-Claims //= (location-label => location-type) location-type = { latitude => number, longitude => number, ? altitude => number, ? accuracy => number, ? altitude-accuracy => number, ? heading => number, ? speed => number, ? timestamp => ~time-int, ? age => uint } -latitude = 1 / "latitude" -longitude = 2 / "longitude" -altitude = 3 / "altitude" -accuracy = 4 / "accuracy" -altitude-accuracy = 5 / "altitude-accuracy" -heading = 6 / "heading" -speed = 7 / "speed" -timestamp = 8 / "timestamp" -age = 9 / "age" -$$claims-set-claims //= (uptime-label => uint) -$$claims-set-claims //= (boot-seed-label => bytes) -$$claims-set-claims //= (odometer-label => uint) -$$claims-set-claims //= ( - intended-use-label => - intended-use-cbor-type / intended-use-json-type -) -intended-use-cbor-type = &( - generic: 1, - registration: 2, - provisioning: 3, - csr: 4, - pop: 5 -) + latitude = JC< "latitude", 1 > + longitude = JC< "longitude", 2 > + altitude = JC< "altitude", 3 > + accuracy = JC< "accuracy", 4 > + altitude-accuracy = JC< "altitude-accuracy", 5 > + heading = JC< "heading", 6 > + speed = JC< "speed", 7 > + timestamp = JC< "timestamp", 8 > + age = JC< "age", 9 > -intended-use-json-type = - "generic" / - "registration" / - "provisioning" / - "csr" / - "pop" -$$claims-set-claims //= ( + $$Claims-Set-Claims //= (uptime-label => uint) + + $$Claims-Set-Claims //= (boot-seed-label => binary-data) + + $$Claims-Set-Claims //= (odometer-label => uint) + + $$Claims-Set-Claims //= ( intended-use-label => intended-use-type ) + + intended-use-type = generic / + registration / + provisioning / + csr / + pop + + generic = JC< "generic", 1 > + registration = JC< "registration", 2 > + provisioning = JC< "provisioning", 3 > + csr = JC< "csr", 4 > + pop = JC< "pop", 5 > + + $$Claims-Set-Claims //= ( dloas-label => [ + dloa-type ] ) dloa-type = [ - dloa_registrar: ~uri + dloa_registrar: general-uri dloa_platform_label: text ? dloa_application_label: text ] -$$claims-set-claims //= (profile-label => ~uri / ~oid) -$$claims-set-claims //= ( + + $$Claims-Set-Claims //= (profile-label => general-uri / general-oid) + $$Claims-Set-Claims //= ( manifests-label => manifests-type ) -manifests-type = [+ $$manifest-formats] + manifests-type = [+ manifest-format] -coswid-that-is-a-cbor-tag-xx = tagged-coswid + manifest-format = [ + content-type: uint, + content-format: JC< $$manifest-body-json, + $$manifest-body-cbor > + ] -$$manifest-formats /= bytes .cbor coswid-that-is-a-cbor-tag-xx$$claims-set-claims //= ( + $$manifest-body-cbor /= bytes .cbor untagged-coswid + $$manifest-body-json /= base64-url-text + + $$manifest-body-cbor /= bytes .cbor SUIT_Envelope + $$manifest-body-json /= base64-url-text + + suit-directive-process-dependency = 19 + + $$Claims-Set-Claims //= ( swevidence-label => swevidence-type ) -swevidence-type = [+ $$swevidence-formats] - -coswid-that-is-a-cbor-tag = tagged-coswid -$$swevidence-formats /= bytes .cbor coswid-that-is-a-cbor-tag -$$claims-set-claims //= (swresults-label => [ + swresult-type ]) + swevidence-type = [+ swevidence-format] -verification-result-cbor-type = &( - verification-not-run: 1, - verification-indeterminate: 2, - verification-failed: 3, - fully-verified: 4, - partially-verified: 5, + swevidence-format = [ + content-type: uint, + content-format: JC< $$swevidence-body-json, + $$swevidence-body-cbor > + ] -) + $$swevidence-body-cbor /= bytes .cbor untagged-coswid + $$swevidence-body-json /= base64-url-text -verification-result-json-type = - "verification-not-run" / - "verification-indeterminate" / - "verification-failed" / - "fully-verified" / - "partially-verified" + $$Claims-Set-Claims //= ( + measurement-results-label => + [ + measurement-results-group ] ) -verification-objective-cbor-type = &( - all: 1, - firmware: 2, - kernel: 3, - privileged: 4, - system-libs: 5, - partial: 6, -) + measurement-results-group = [ + measurement-system: tstr, + measruement-results: [ + individual-result ] + ] -verification-objective-json-type = - "all" / - "firmware" / - "kernel" / - "privileged" / - "system-libs" / - "partial" + individual-result = [ + results-id: tstr / binary-data, + result: result-type, -swresult-type = [ - verification-system: tstr, - objective: verification-objective-cbor-type / - verification-objective-json-type, - result: verification-result-cbor-type / - verification-result-json-type, - ? objective-name: tstr ] -$$claims-set-claims //= (submods-label => { + text => Submodule }) + + result-type = comparison-successful / + comparison-fail / + comparison-not-run / + measurement-absent + + comparison-successful = JC< "success", 1 > + comparison-fail = JC< "fail", 2 > + comparison-not-run = JC< "not-run", 3 > + measurement-absent = JC< "absent", 4 > + + $$Claims-Set-Claims //= (submods-label => { + text => Submodule }) Submodule = Claims-Set / Nested-Token / Detached-Submodule-Digest Detached-Submodule-Digest = [ - algorithm : int / text, - digest : bstr + algorithm : JC< text, int > + digest : binary-data ] + + DEB-Messages = DEB-Tagged-Message / DEB-Untagged-Message + + DEB-Tagged-Message = #6.TBD(DEB-Untagged-Message) + DEB-Untagged-Message = Detached-EAT-Bundle + Detached-EAT-Bundle = [ main-token : Nested-Token, detached-claims-sets: { - + tstr => cbor-wrapped-claims-set / json-wrapped-claims-set - + + tstr => JC } ] -json-wrapped-claims-set = tstr .regexp "[A-Za-z0-9_=-]+" + json-wrapped-claims-set = base64-url-text cbor-wrapped-claims-set = bstr .cbor Claims-Set -8.5. Collected CDDL for CBOR - - CBOR-Token = Tagged-CBOR-Token / Untagged-CBOR-Token + nonce-label = JC< "eat_nonce", 10 > + ueid-label = JC< "ueid", 256 > + sueids-label = JC< "sueids", 257 > + oemid-label = JC< "oemid", 258 > + hardware-model-label = JC< "hwmodel", 259 > + hardware-version-label = JC< "hwvers", 260 > + secure-boot-label = JC< "secboot", 262 > + debug-status-label = JC< "dbgstat", 263 > + location-label = JC< "location", 264 > + profile-label = JC< "eat_profile",265 > + submods-label = JC< "submods", 266 > - Tagged-CBOR-Token = CWT-Tagged-Message - Tagged-CBOR-Token /= UCCS-Tagged-Message - Tagged-CBOR-Token /= DEB-Tagged-Message + security-level-label = JC< "seclevel", TBD > + uptime-label = JC< "uptime", TBD > + boot-seed-label = JC< "bootseed", TBD > + intended-use-label = JC< "intuse", TBD > + dloas-label = JC< "dloas", TBD > + sw-name-label = JC< "swname", TBD > + sw-version-label = JC< "swversion", TBD > + manifests-label = JC< "manifests", TBD > + swevidence-label = JC< "swevidence", TBD > + measurement-results-label = JC< "measres" , TBD > + odometer-label = JC< "odometer", TBD > - Untagged-CBOR-Token = CWT-Untagged-Message - Untagged-CBOR-Token /= UCCS-Untagged-Message - Untagged-CBOR-Token /= DEB-Untagged-Message +8.4.2. CBOR-Specific CDDL - CWT-Tagged-Message = COSE_Tagged_Message - CWT-Untagged-Message = COSE_Untagged_Message + EAT-CBOR-Token = $$EAT-CBOR-Tagged-Token / $$EAT-CBOR-Untagged-Token - UCCS-Message = UCCS-Tagged-Message / UCCS-Untagged-Message + $$EAT-CBOR-Tagged-Token /= CWT-Tagged-Message + $$EAT-CBOR-Tagged-Token /= DEB-Tagged-Message - UCCS-Tagged-Message = #6.601(UCCS-Untagged-Message) + $$EAT-CBOR-Untagged-Token /= CWT-Untagged-Message + $$EAT-CBOR-Untagged-Token /= DEB-Untagged-Message - UCCS-Untagged-Message = Claims-Set + Nested-Token = CBOR-Nested-Token - DEB-Tagged-Message = #6.602(DEB-Untagged-Message) + CBOR-Nested-Token = + JSON-Token-Inside-CBOR-Token / + CBOR-Token-Inside-CBOR-Token - DEB-Untagged-Message = Detached-EAT-Bundle + CBOR-Token-Inside-CBOR-Token = bstr .cbor $$EAT-CBOR-Tagged-Token - Nested-Token = - tstr / ; A JSON-encoded Nested-Token (see json-nested-token.cddl) - bstr .cbor Tagged-CBOR-Token + JSON-Token-Inside-CBOR-Token = tstr - iss-label = 1 - sub-label = 2 - aud-label = 3 - exp-label = 4 - nbf-label = 5 - iat-label = 6 - cti-label = 7nonce-label = 10 - ueid-label = 256 - sueids-label = 257 - oemid-label = 258 - hardware-model-label = 259 - hardware-version-label = 260 - secure-boot-label = 262 - debug-status-label = 263 - location-label = 264 - profile-label = 265 - submods-label = 266 - security-level-label = - uptime-label = - boot-seed-label = - odometer-label = - intended-use-label = - dloas-label = - sw-name-label = - sw-version-label = - manifests-label = - swevidence-label = - swresults-label = +8.4.3. JSON-Specific CDDL -8.6. Collected CDDL for JSON + EAT-JSON-Token = $$EAT-JSON-Token-Formats -JWT-Message = text .regexp [A-Za-z0-9_=-]+\.[A-Za-z0-9_=-]+\.[A-Za-z0-9_=-]+ + $$EAT-JSON-Token-Formats /= JWT-Message + $$EAT-JSON-Token-Formats /= DEB-Untagged-Message -UJCS-Message = Claims-Set + Nested-Token = JSON-Nested-Token -Nested-Token = [ - type : "JWT" / "CBOR" / "UJCS" / "DEB", + JSON-Nested-Token = [ + type : "JWT" / "CBOR" / "DEB", nested-token : JWT-Message / - B64URL-Tagged-CBOR-Token / - DEB-JSON-Message / - UJCS-Message + CBOR-Token-Inside-JSON-Token / + Detached-EAT-Bundle ] -B64URL-Tagged-CBOR-Token = tstr .regexp "[A-Za-z0-9_=-]+" -iss-label = "iss" -sub-label = "sub" -aud-label = "aud" -exp-label = "exp" -nbf-label = "nbf" -iat-label = "iat" -cti-label = "cti"nonce-label /= "nonce" - -ueid-label /= "ueid" -sueids-label /= "sueids" -oemid-label /= "oemid" -hardware-model-label /= "hwmodel" -hardware-version-label /= "hwversion" -security-level-label /= "seclevel" -secure-boot-label /= "secboot" -debug-status-label /= "dbgstat" -location-label /= "location" -profile-label /= "eat-profile" -uptime-label /= "uptime" -boot-seed-label /= "bootseed" -odometer-label /= "odometer" -intended-use-label /= "intuse" -dloas-label /= "dloas" -sw-name-label /= "swname" -sw-version-label /= "swversion" -manifests-label /= "manifests" -swevidence-label /= "swevidence" -swresults-label /= "swresults" -submods-label /= "submods" - -latitude /= "lat" -longitude /= "long" -altitude /= "alt" -accuracy /= "accry" -altitude-accuracy /= "alt-accry" -heading /= "heading" -speed /= "speed" + CBOR-Token-Inside-JSON-Token = base64-url-text 9. IANA Considerations 9.1. Reuse of CBOR and JSON Web Token (CWT and JWT) Claims Registries Claims defined for EAT are compatible with those of CWT and JWT so the CWT and JWT Claims Registries, [IANA.CWT.Claims] and [IANA.JWT.Claims], are re used. No new IANA registry is created. All EAT claims defined in this document are placed in both @@ -2704,30 +2695,29 @@ o Claim Description: Semi-permanent UEIDs o JWT Claim Name: "sueids" o CWT Claim Key: TBD (requested value 257) o Claim Value Type(s): map o Change Controller: IESG - o Specification Document(s): *this document* o Claim Name: Hardware OEMID o Claim Description: Hardware OEM ID o JWT Claim Name: "oemid" - o Claim Key: TBD (requested value 258) + o Claim Key: TBD (requeste value 258) o Claim Value Type(s): byte string or integer o Change Controller: IESG o Specification Document(s): *this document* o Claim Name: Hardware Model o Claim Description: Model identifier for hardware @@ -2751,38 +2742,37 @@ o Claim Value Type(s): array o Change Controller: IESG o Specification Document(s): *this document* o Claim Name: Secure Boot o Claim Description: Indicate whether the boot was secure - o JWT Claim Name: "secboot" - o Claim Key: TBD (requested value 262) + o Claim Key: 262 o Claim Value Type(s): Boolean o Change Controller: IESG o Specification Document(s): *this document* o Claim Name: Debug Status o Claim Description: Indicate status of debug facilities o JWT Claim Name: "dbgstat" - o Claim Key: TBD (requested value 263) + o Claim Key: 263 o Claim Value Type(s): integer or string o Change Controller: IESG o Specification Document(s): *this document* o Claim Name: Location o Claim Description: The geographic location @@ -3174,21 +3164,21 @@ downstream consumers is not strictly required. Nevertheless, downstream consumers of a nested EAT should provide a nonce unique to the EAT they are consuming. 12. References 12.1. Normative References [CoSWID] Birkholz, H., Fitzgerald-McKay, J., Schmidt, C., and D. Waltermire, "Concise Software Identification Tags", draft- - ietf-sacm-coswid-20 (work in progress), January 2022. + ietf-sacm-coswid-21 (work in progress), March 2022. [DLOA] "Digital Letter of Approval", November 2015, . [EAN-13] GS1, "International Article Number - EAN/UPC barcodes", 2019, . [FIDO.AROE] The FIDO Alliance, "FIDO Authenticator Allowed Restricted @@ -3226,20 +3216,25 @@ [RFC3986] Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform Resource Identifier (URI): Generic Syntax", STD 66, RFC 3986, DOI 10.17487/RFC3986, January 2005, . [RFC7159] Bray, T., Ed., "The JavaScript Object Notation (JSON) Data Interchange Format", RFC 7159, DOI 10.17487/RFC7159, March 2014, . + [RFC7252] Shelby, Z., Hartke, K., and C. Bormann, "The Constrained + Application Protocol (CoAP)", RFC 7252, + DOI 10.17487/RFC7252, June 2014, + . + [RFC7515] Jones, M., Bradley, J., and N. Sakimura, "JSON Web Signature (JWS)", RFC 7515, DOI 10.17487/RFC7515, May 2015, . [RFC7516] Jones, M. and J. Hildebrand, "JSON Web Encryption (JWE)", RFC 7516, DOI 10.17487/RFC7516, May 2015, . [RFC7517] Jones, M., "JSON Web Key (JWK)", RFC 7517, DOI 10.17487/RFC7517, May 2015, @@ -3292,25 +3287,20 @@ DOI 10.17487/RFC9090, July 2021, . [ThreeGPP.IMEI] 3GPP, "3rd Generation Partnership Project; Technical Specification Group Core Network and Terminals; Numbering, addressing and identification", 2019, . - [UCCS.Draft] - Birkholz, H., O'Donoghue, J., Cam-Winget, N., and C. - Bormann, "A CBOR Tag for Unprotected CWT Claims Sets", - draft-ietf-rats-uccs-02 (work in progress), January 2022. - [WGS84] National Geospatial-Intelligence Agency (NGA), "WORLD GEODETIC SYSTEM 1984, NGA.STND.0036_1.0.0_WGS84", July 2014, . 12.2. Informative References [BirthdayAttack] "Birthday attack", . @@ -3398,58 +3388,75 @@ DOI 10.17487/RFC9039, June 2021, . [W3C.GeoLoc] Worldwide Web Consortium, "Geolocation API Specification 2nd Edition", January 2018, . Appendix A. Examples - These examples are either UCCS, shown as CBOR diagnostic, or UJCS - messages. Full CWT and JWT examples with signing and encryption are - not given. - - All UCCS examples can be the payload of a CWT. To do so, they must - be converted from the UCCS message to a Claims-Set, which is achieve - by "removing" the tag. + Most examples are shown as just a Claims-Set that would be a payload + for a CWT, JWT, DEB or future token types. It is shown this way + because the payload is all the claims, the most interesting part and + showing full tokens makes it harder to show the claims. - UJCS messages can be directly used as the payload of a JWT. + Some examples of full tokens are also given. WARNING: These examples use tag and label numbers not yet assigned by IANA. -A.1. Simple TEE Attestation +A.1. Payload Examples + +A.1.1. Simple TEE Attestation This is a simple attestation of a TEE that includes a manifest that is a payload CoSWID to describe the TEE's software. - / This is a UCCS EAT that describes a simple TEE. / + / This is an EAT payload that describes a simple TEE. / - 601({ + { / nonce / 10: h'948f8860d13a463e', - / security-level / 261: 3, / secure-restricted / + / security-level / 261: 2, / restricted / / secure-boot / 262: true, / debug-status / 263: 2, / disabled-since-boot / / manfests / 273: [ + [ + 121, / CoAP Content ID. A / + / made up one until one / + / is assigned for CoSWID / + / This is byte-string wrapped / / payload CoSWID. It gives the TEE / / software name, the version and / / the name of the file it is in. / - h' da53574944a60064336132340c01016b + / {0: "3a24", / + / 12: 1, / + / 1: "Acme TEE OS", / + / 13: "3.1.4", / + / 2: [{31: "Acme TEE OS", 33: 1}, / + / {31: "Acme TEE OS", 33: 2}], / + / 6: { / + / 17: { / + / 24: "acme_tee_3.exe" / + / } / + / } / + / } / + h' a60064336132340c01016b 41636d6520544545204f530d65332e31 2e340282a2181f6b41636d6520544545 204f53182101a2181f6b41636d652054 4545204f5318210206a111a118186e61 636d655f7465655f332e657865' ] - }) + ] + } / A payload CoSWID created by the SW vendor. All this really does / / is name the TEE SW, its version and lists the one file that / / makes up the TEE. / 1398229316({ / Unique CoSWID ID / 0: "3a24", / tag-version / 12: 1, / software-name / 1: "Acme TEE OS", / software-version / 13: "3.1.4", / entity / 2: [ @@ -3462,21 +3469,21 @@ / role / 33: 2 / software-creator / } ], / payload / 6: { / ...file / 17: { / ...fs-name / 24: "acme_tee_3.exe" } } }) -A.2. Submodules for Board and Device +A.1.2. Submodules for Board and Device / This example shows use of submodules to give information / / about the chip, board and overall device. / / / / The main attestation is associated with the chip with the / / CPU and running the main OS. It is what has the keys and / / produces the token. / / / / The board is made by a different vendor than the chip. / / Perhaps it is some generic IoT board. / / / @@ -3492,156 +3499,224 @@ / UEID / 256: h'0198f50a4ff6c05861c8860d13a638ea', / HW OEM ID / 258: h'894823', / IEEE OUI format OEM ID / / HW Model ID / 259: h'549dcecc8b987c737b44e40f7c635ce8' / Hash of chip model name /, / HW Version / 260: ["1.3.4", 1], / Multipartnumeric version / / SW Name / 271: "Acme OS", / SW Version / 272: ["3.5.5", 1], / secure-boot / 262: true, / debug-status / 263: 3, / permanent-disable / / timestamp (iat) / 6: 1526542894, - / security-level / 261: 3, / secure restricted OS / + / security-level / 261: 2, / restricted OS / / submods / 266: { / A submodule to hold some claims about the circuit board / "board" : { / HW OEM ID / 258: h'9bef8787eba13e2c8f6e7cb4b1f4619a', / HW Model ID / 259: h'ee80f5a66c1fb9742999a8fdab930893' / Hash of board module name /, / HW Version / 260: ["2.0a", 2] / multipartnumeric+suffix / }, / A submodule to hold claims about the overall device / "device" : { / HW OEM ID / 258: 61234, / PEN Format OEM ID / / HW Version / 260: ["4012345123456", 5] / EAN-13 format (barcode) / } } } -A.3. EAT Produced by Attestation Hardware Block +A.1.3. EAT Produced by Attestation Hardware Block / This is an example of a token produced by a HW block / / purpose-built for attestation. Only the nonce claim changes / / from one attestation to the next as the rest either come / / directly from the hardware or from one-time-programmable memory / / (e.g. a fuse). 47 bytes encoded in CBOR (8 byte nonce, 16 byte / / UEID). / - 601({ + { / nonce / 10: h'948f8860d13a463e', / UEID / 256: h'0198f50a4ff6c05861c8860d13a638ea', / OEMID / 258: 64242, / Private Enterprise Number / - / security-level / 261: 4, / hardware level security / + / security-level / 261: 3, / hardware level security / / secure-boot / 262: true, / debug-status / 263: 3, / disabled-permanently / / HW version / 260: [ "3.1", 1 ] / Type is multipartnumeric / - }) - -A.4. Detached EAT Bundle - - In this DEB main token is produced by a HW attestation block. The - detached Claims-Set is produced by a TEE and is largely identical to - the Simple TEE examples above. The TEE digests its Claims-Set and - feeds that digest to the HW block. + } - In a better example the attestation produced by the HW block would be - a CWT and thus signed and secured by the HW block. Since the - signature covers the digest from the TEE that Claims-Set is also - secured. +A.1.4. Key / Key Store Attestation + / This is an EAT payload that describes a simple TEE. / - The DEB itself can be assembled by untrusted SW. + { + / nonce / 10: h'948f8860d13a463e', + / security-level / 261: 2, / restricted / + / secure-boot / 262: true, + / debug-status / 263: 2, / disabled-since-boot / + / manfests / 273: [ + [ + 121, / CoAP Content ID. A / + / made up one until one / + / is assigned for CoSWID / - / This is a detached EAT bundle (DEB) tag. / + / This is byte-string wrapped / + / payload CoSWID. It gives the TEE / + / software name, the version and / + / the name of the file it is in. / + / {0: "3a24", / + / 12: 1, / + / 1: "Acme TEE OS", / + / 13: "3.1.4", / + / 2: [{31: "Acme TEE OS", 33: 1}, / + / {31: "Acme TEE OS", 33: 2}], / + / 6: { / + / 17: { / + / 24: "acme_tee_3.exe" / + / } / + / } / + / } / + h' a60064336132340c01016b + 41636d6520544545204f530d65332e31 + 2e340282a2181f6b41636d6520544545 + 204f53182101a2181f6b41636d652054 + 4545204f5318210206a111a118186e61 + 636d655f7465655f332e657865' + ] + ] + } + / A payload CoSWID created by the SW vendor. All this really does / + / is name the TEE SW, its version and lists the one file that / + / makes up the TEE. / - 602([ + 1398229316({ + / Unique CoSWID ID / 0: "3a24", + / tag-version / 12: 1, + / software-name / 1: "Acme TEE OS", + / software-version / 13: "3.1.4", + / entity / 2: [ + { + / entity-name / 31: "Acme TEE OS", + / role / 33: 1 / tag-creator / + }, + { + / entity-name / 31: "Acme TEE OS", + / role / 33: 2 / software-creator / + } + ], + / payload / 6: { + / ...file / 17: { + / ...fs-name / 24: "acme_tee_3.exe" + } + } + }) - / First part is a full EAT token with claims like nonce and / - / UEID. Most importantly, it includes a submodule that is a / - / detached digest which is the hash of the "TEE" claims set / - / in the next section. / +A.1.5. Submodules for Board and Device +/ This example shows use of submodules to give information / +/ about the chip, board and overall device. / / / - / This token here is in UCCS format (unsigned). In a more / - / realistic example, it would be a signed CWT. / - h'd90259a80a48948f8860d13a463e190100500198 - f50a4ff6c05861c8860d13a638ea19010219faf2 - 19010504190106f5190107031901048263332e31 - 0119010aa163544545822f5820e5cf95fd24fab7 - 1446742dd58d43dae178e55fe2b94291a9291082 - ffc2635a0b', +/ The main attestation is associated with the chip with the / +/ CPU and running the main OS. It is what has the keys and / +/ produces the token. / +/ / +/ The board is made by a different vendor than the chip. / +/ Perhaps it is some generic IoT board. / +/ / +/ The device is some specific appliance that is made by a / +/ different vendor than either the chip or the board. / +/ / +/ Here the board and device submodules aren't the typical / +/ target environments as described by the RATS architecture / +/ document, but they are a valid use of submodules. / + { - / A CBOR-encoded byte-string wrapped EAT claims-set. It / - / contains claims suitable for a TEE / - "TEE" : h'a50a48948f8860d13a463e19010503190106f519 - 01070219011181585dda53574944a60064336132 - 340c01016b41636d6520544545204f530d65332e - 312e340282a2181f6b41636d6520544545204f53 - 182101a2181f6b41636d6520544545204f531821 - 0206a111a118186e61636d655f7465655f332e65 - 7865' + / nonce / 10: h'948f8860d13a463e8e', + / UEID / 256: h'0198f50a4ff6c05861c8860d13a638ea', + / HW OEM ID / 258: h'894823', / IEEE OUI format OEM ID / + / HW Model ID / 259: h'549dcecc8b987c737b44e40f7c635ce8' + / Hash of chip model name /, + / HW Version / 260: ["1.3.4", 1], / Multipartnumeric version / + / SW Name / 271: "Acme OS", + / SW Version / 272: ["3.5.5", 1], + / secure-boot / 262: true, + / debug-status / 263: 3, / permanent-disable / + / timestamp (iat) / 6: 1526542894, + / security-level / 261: 2, / restricted OS / + / submods / 266: { + / A submodule to hold some claims about the circuit board / + "board" : { + / HW OEM ID / 258: h'9bef8787eba13e2c8f6e7cb4b1f4619a', + / HW Model ID / 259: h'ee80f5a66c1fb9742999a8fdab930893' + / Hash of board module name /, + / HW Version / 260: ["2.0a", 2] / multipartnumeric+suffix / + }, + + / A submodule to hold claims about the overall device / + "device" : { + / HW OEM ID / 258: 61234, / PEN Format OEM ID / + / HW Version / 260: ["4012345123456", 5] / EAN-13 format (barcode) / } - ]) + } +} +A.1.6. EAT Produced by Attestation Hardware Block - / This example contains submodule that is a detached digest, / - / which is the hash of a Claims-Set convey outside this token. / - / Other than that is is the other example of a token from an / - / attestation HW block / + / This is an example of a token produced by a HW block / + / purpose-built for attestation. Only the nonce claim changes / + / from one attestation to the next as the rest either come / + / directly from the hardware or from one-time-programmable memory / + / (e.g. a fuse). 47 bytes encoded in CBOR (8 byte nonce, 16 byte / + / UEID). / - 601({ + { / nonce / 10: h'948f8860d13a463e', / UEID / 256: h'0198f50a4ff6c05861c8860d13a638ea', / OEMID / 258: 64242, / Private Enterprise Number / - / security-level / 261: 4, / hardware level security / + / security-level / 261: 3, / hardware level security / / secure-boot / 262: true, / debug-status / 263: 3, / disabled-permanently / - / hw version / 260: [ "3.1", 1 ], / multipartnumeric / - / submods/ 266: { - "TEE": [ / detached digest submod / - -16, / SHA-256 / - h'e5cf95fd24fab7144674 - 2dd58d43dae178e55fe2 - b94291a9291082ffc2635 - a0b' - ] + / HW version / 260: [ "3.1", 1 ] / Type is multipartnumeric / } - }) -A.5. Key / Key Store Attestation +A.1.7. Key / Key Store Attestation / This is an attestation of a public key and the key store / / implementation that protects and manages it. The key store / / implementation is in a security-oriented execution / / environment separate from the high-level OS, for example a / / TEE. The key store is the Attester. / / / / There is some attestation of the high-level OS, just version / / and boot & debug status. It is a Claims-Set submodule because/ / it has lower security level than the key store. The key / / store's implementation has access to info about the HLOS, so / / it is able to include it. / / / / A key and an indication of the user authentication given to / / allow access to the key is given. The labels for these are / / in the private space since this is just a hypothetical / / example, not part of a standard protocol. / / / / This is similar to Android Key Attestation. / - 601({ + { / nonce / 10: h'948f8860d13a463e', - / security-level / 261: 3, / secure-restricted / + / security-level / 261: 2, / restricted / / secure-boot / 262: true, / debug-status / 263: 2, / disabled-since-boot / / manifests / 273: [ - h'da53574944a600683762623334383766 + + [ 121, / CoAP Content ID. A / + / made up one until one / + / is assigned for CoSWID / + h'a600683762623334383766 0c000169436172626f6e6974650d6331 2e320e0102a2181f75496e6475737472 69616c204175746f6d6174696f6e1821 02' + ] / Above is an encoded CoSWID / / with the following data / / SW Name: "Carbonite" / / SW Vers: "1.2" / / SW Creator: / / "Industrial Automation" / ], / expiration / 4: 1634324274, / 2021-10-15T18:57:54Z / / creation time / 6: 1634317080, / 2021-10-15T16:58:00Z / -80000 : "fingerprint", @@ -3654,88 +3729,98 @@ / y-coord / -3: h'1e52ed75701163f7f9e40ddf9f341b3d c9ba860af7e0ca7ca7e9eecd0084d19c' }, / submods / 266 : { "HLOS" : { / submod for high-level OS / / nonce / 10: h'948f8860d13a463e', / security-level / 261: 1, / unrestricted / / secure-boot / 262: true, / manifests / 273: [ - h'da53574944a600687337 + [ 121, / CoAP Content ID. A / + / made up one until one / + / is assigned for CoSWID / + h'a600687337 6537346b78380c000168 44726f6964204f530d65 52322e44320e0302a218 1F75496E647573747269 616c204175746f6d6174 696f6e182102' + ] / Above is an encoded CoSWID / / with the following data: / / SW Name: "Droid OS" / / SW Vers: "R2.D2" / / SW Creator: / / "Industrial Automation"/ ] } } - }) + } -A.6. SW Measurements of an IoT Device +A.1.8. SW Measurements of an IoT Device This is a simple token that might be for and IoT device. It includes CoSWID format measurments of the SW. The CoSWID is in byte-string wrapped in the token and also shown in diagnostic form. - / This EAT UCCS is for an IoT device with a TEE. The attestation / + / This EAT payload is for an IoT device with a TEE. The attestation / / is produced by the TEE. There is a submodule for the IoT OS (the / / main OS of the IoT device that is not as secure as the TEE). The / / submodule contains claims for the IoT OS. The TEE also measures / / the IoT OS and puts the measurements in the submodule. / - 601({ + { / nonce / 10: h'948f8860d13a463e', - / security-level / 261: 3, / secure-restricted / + / security-level / 261: 2, / restricted / / secure-boot / 262: true, / debug-status / 263: 2, / disabled-since-boot / / OEMID / 258: h'8945ad', / IEEE CID based / / UEID / 256: h'0198f50a4ff6c05861c8860d13a638ea', / sumods / 266: { "OS" : { / security-level / 261: 2, / restricted / / secure-boot / 262: true, / debug-status / 263: 2, / disabled-since-boot / / swevidence / 274: [ + [ + 121, / CoAP Content ID. A / + / made up one until one / + / is assigned for CoSWID / + / This is a byte-string wrapped / / evidence CoSWID. It has / / hashes of the main files of / / the IoT OS. / - h'da53574944a600663463613234350c + h'a600663463613234350c 17016d41636d6520522d496f542d4f 530d65332e312e3402a2181f724163 6d6520426173652041747465737465 7218210103a11183a318187161636d 655f725f696f745f6f732e65786514 1a0044b349078201582005f6b327c1 73b4192bd2c3ec248a292215eab456 611bf7a783e25c1782479905a31818 6d7265736f75726365732e72736314 1a000c38b10782015820c142b9aba4 280c4bb8c75f716a43c99526694caa be529571f5569bb7dc542f98a31818 6a636f6d6d6f6e2e6c6962141a0023 3d3b0782015820a6a9dcdfb3884da5 f884e4e1e8e8629958c2dbc7027414 43a913e34de9333be6' ] + ] + } } } - }) / An evidence CoSWID created for the "Acme R-IoT-OS" created by / / the "Acme Base Attester" (both fictious names). It provides / / measurements of the SW (other than the attester SW) on the / / device. / 1398229316({ / Unique CoSWID ID / 0: "4ca245", / tag-version / 12: 23, / Attester-maintained counter / / software-name / 1: "Acme R-IoT-OS", @@ -3773,66 +3858,206 @@ / ...size / 20: 2309435, / ...hash / 7: [ 1, / SHA-256 / h'a6a9dcdfb3884da5 f884e4e1e8e86299 58c2dbc702741443 a913e34de9333be6' ] } ] - } }) -A.7. Attestation Results in JSON format +A.1.9. Attestation Results in JSON format - This is a UJCS format token that might be the output of a Verifier + This is a JSON-format payload that might be the output of a Verifier that evaluated the IoT Attestation example immediately above. This particular Verifier knows enough about the TEE Attester to be able to pass claims like security level directly through to the Relying Party. The Verifier also knows the Reference Values for the measured SW components and is able to check them. It informs the Relying Party that they were correct in the swresults claim. "Trustus Verifications" is the name of the services that verifies the SW component measurements. - This UJCS is identical to JSON-encoded Claims-Set that could be a JWT - payload. - { - "nonce" : "lI+IYNE6Rj4=", - "seclevel" : "secure-restricted", - "secboot" : true, - "dbgstat" : "disabled-since-boot", - "OEMID" : "iUWt", - "UEID" : "AZj1Ck/2wFhhyIYNE6Y4", - "submods" : { + "eat_nonce" : "jkd8KL-8=Qlzg4", "seclevel" : "restricted", "secboot" : true, "dbgstat" : "disabled-since-boot", + "oemid" : "iUWt", + "ueid" : "AZj1Ck_2wFhhyIYNE6Y4", "swname" : "Acme R-IoT-OS", - "sw-version" : [ + "swversion" : [ "3.1.4" ], - "swresults" : [ + "measres" : [ [ - "Trustus Verifications", - "all", - "fully-verified" + "Trustus Measurements", + [ + [ "all" , "success" ] + ] ] ] } -Appendix B. UEID Design Rationale +A.1.10. JSON-encoded Token with Sumodules +{ + "eat_nonce": "lI-IYNE6Rj6O", + "ueid": "AJj1Ck_2wFhhyIYNE6Y46g==", + "secboot": true, + "dbgstat": "disabled-permanently", + "iat": 1526542894, + "seclevel": "restricted", + "submods": { + "Android App Foo" : { + "seclevel": "unrestricted" + }, + + "Secure Element Eat" : [ + "CBOR", + "2D3ShEOhASagWGaoCkiUj4hg0TpGPhkBAFABmPUKT_bAWGHIhg0TpjjqGQECGfryGQEFBBkBBvUZAQcDGQEEgmMzLjEBGQEKoWNURUWCL1gg5c-V_ST6txRGdC3VjUPa4XjlX-K5QpGpKRCC_8JjWgtYQPaQywOIZ3-mJKN3X9fLxOhAnsmBa-MvpHRzOw-Ywn-67bvJljuctezAPD41s6_At7NbSV3qwJlxIuqGfwe41es=" + ], + + "Linux Android": { + "seclevel": "unrestricted" + }, + + "Subsystem J": [ + "JWT", + "eyJ0eXAiOiJKV1QiLCJhbGciOiJIUzI1NiJ9.eyJpc3MiOiJKLUF0dGVzdGVyIiwiaWF0IjoxNjUxNzc0ODY4LCJleHAiOm51bGwsImF1ZCI6IiIsInN1YiI6IiJ9.gjw4nFMhLpJUuPXvMPzK1GMjhyJq2vWXg1416XKszwQ" + ] + } +} + +A.2. Full Token Examples + +A.2.1. Basic CWT Example + + This is a simple ECDSA signed CWT-format token. + + / This is a full CWT-format token with a very simple payloal. / + / The main structure visible here is that of the COSE_Sign1. / + + 61( 18( [ + h'A10126', / protected headers / + {}, / empty unprotected headers / + h'A20B46024A6B0978DE0A49000102030405060708', / payload / + h'9B9B2F5E470000F6A20C8A4157B5763FC45BE759 + 9A5334028517768C21AFFB845A56AB557E0C8973 + A07417391243A79C478562D285612E292C622162 + AB233787' / signature / + ] ) ) + +A.2.2. Detached EAT Bundle + + In this DEB main token is produced by a HW attestation block. The + detached Claims-Set is produced by a TEE and is largely identical to + the Simple TEE examples above. The TEE digests its Claims-Set and + feeds that digest to the HW block. + + In a better example the attestation produced by the HW block would be + a CWT and thus signed and secured by the HW block. Since the + signature covers the digest from the TEE that Claims-Set is also + secured. + + The DEB itself can be assembled by untrusted SW. + +/ This is a detached EAT bundle (DEB) tag. / +/ Note that 602, the tag identifying a DEB is not yet registered with IANA / + +602([ + + / First part is a full EAT token with claims like nonce and / + / UEID. Most importantly, it includes a submodule that is a / + / detached digest which is the hash of the "TEE" claims set / + / in the next section. The COSE payload follows: / + / { / + / 10: h'948F8860D13A463E', / + / 256: h'0198F50A4FF6C05861C8860D13A638EA', / + / 258: 64242, / + / 261: 4, / + / 262: true, / + / 263: 3, / + / 260: ["3.1", 1], / + / 266: { / + / "TEE": [ / + / -16, / + / h'E5CF95FD24FAB71446742DD58D43DAE1 / + / 78E55FE2B94291A9291082FFC2635A0B' / + / ] / + / } / + / } / + h'D83DD28443A10126A05866A80A48948F8860D13A463E1901 + 00500198F50A4FF6C05861C8860D13A638EA19010219FAF2 + 19010504190106F5190107031901048263332E310119010A + A163544545822F5820E5CF95FD24FAB71446742DD58D43DA + E178E55FE2B94291A9291082FFC2635A0B5840F690CB0388 + 677FA624A3775FD7CBC4E8409EC9816BE32FA474733B0F98 + C27FBAEDBBC9963B9CB5ECC03C3E35B3AFC0B7B35B495DEA + C0997122EA867F07B8D5EB', + { + / A CBOR-encoded byte-string wrapped EAT claims-set. It / + / contains claims suitable for a TEE / + "TEE" : h'a50a48948f8860d13a463e19010503190106 + f519010702190111818218795858a6006433 + 6132340c01016b41636d6520544545204f53 + 0d65332e312e340282a2181f6b41636d6520 + 544545204f53182101a2181f6b41636d6520 + 544545204f5318210206a111a118186e6163 + 6d655f7465655f332e657865' + } + ]) + / This example contains submodule that is a detached digest, / + / which is the hash of a Claims-Set convey outside this token. / + / Other than that is is the other example of a token from an / + / attestation HW block / + + { + / nonce / 10: h'948f8860d13a463e', + / UEID / 256: h'0198f50a4ff6c05861c8860d13a638ea', + / OEMID / 258: 64242, / Private Enterprise Number / + / security-level / 261: 3, / hardware level security / + / secure-boot / 262: true, + / debug-status / 263: 3, / disabled-permanently / + / hw version / 260: [ "3.1", 1 ], / multipartnumeric / + / submods/ 266: { + "TEE": [ / detached digest submod / + -16, / SHA-256 / + h'e5cf95fd24fab7144674 + 2dd58d43dae178e55fe2 + b94291a9291082ffc2635 + a0b' + ] + } + } + +A.2.3. JSON-encoded Detached EAT Bundle + + In this bundle there are two detached Claims-Sets, "CS1" and "CS2". + The JWT at the start of the bundle has detached signature submodules + with hashes of "CS1" and "CS2". TODO: make the JWT actually be + correct verifiable JWT. +[ + [ "JWT", + "eyJ0eXAiOiJKV1QiLCJhbGciOiJIUzI1NiJ9.eyJpc3MiOiJKLUF0dGVzdGVyIiwiaWF0IjoxNjUxNzc0ODY4LCJleHAiOm51bGwsImF1ZCI6IiIsInN1YiI6IiJ9.gjw4nFMhLpJUuPXvMPzK1GMjhyJq2vWXg1416XKszwQ" + ], + { + "Audio Subsystem Claims": "ewogICAgICAgICAgICAibm9uY2UiOiAgICAgImxJK0lZTkU2Umo2TyIsCiAgICAgICAgICAgICJpYXQiOiAgICAgIDE1MjY1NDI4OTQKICAgICAgICAgfQo=", + "Graphics Subsystem Claims": "ewogICAgICAgICAgICAibm9uY2UiOiAgICJsSStJWU5FNlJqNk8iLAogICAgICAgICAgICAiaWF0IjogICAgIDE1MjY1NDI4OTQKICAgICAgICB9" + } +] + +Appendix B. UEID Design Rationale B.1. Collision Probability This calculation is to determine the probability of a collision of UEIDs given the total possible entity population and the number of entities in a particular entity management database. Three different sized databases are considered. The number of devices per person roughly models non-personal devices such as traffic lights, devices in stores they shop in, facilities they work in and so on, even considering individual light bulbs. A device may @@ -4072,70 +4297,136 @@ described this way because [IEEE.802.1AR] is oriented around the definition of an implementation with a particular level of defense against attack. EAT is not defined around a particular implementation and must work on a range of devices that have a range of defenses against attack. EAT thus can't be defined permanence in terms of defense against attack. EAT's definition of permanence is in terms of operations and device lifecycle. -Appendix D. Changes from Previous Drafts +Appendix D. CDDL for CWT and JWT + + [RFC8392] was published before CDDL was available and thus is + specified in prose, not CDDL. Following is CDDL specifying CWT as it + is needed to complete this specification. This CDDL also covers the + Claims-Set for JWT. + + This however is NOT a normative or standard definition of CWT or JWT + in CDDL. The prose in CWT and JWT remain the normative definition. + + ; This is replicated from draft-ietf-rats-uccs + + Claims-Set = { + * $$Claims-Set-Claims + * Claim-Label .feature "extended-claims-label" => any + } + Claim-Label = int / text + string-or-uri = text + + $$Claims-Set-Claims //= ( iss-claim-label => string-or-uri ) + $$Claims-Set-Claims //= ( sub-claim-label => string-or-uri ) + $$Claims-Set-Claims //= ( aud-claim-label => string-or-uri ) + $$Claims-Set-Claims //= ( exp-claim-label => ~time ) + $$Claims-Set-Claims //= ( nbf-claim-label => ~time ) + $$Claims-Set-Claims //= ( iat-claim-label => ~time ) + $$Claims-Set-Claims //= ( cti-claim-label => bytes ) + + iss-claim-label = JC<"iss", 1> + sub-claim-label = JC<"sub", 2> + aud-claim-label = JC<"aud", 3> + exp-claim-label = JC<"exp", 4> + nbf-claim-label = JC<"nbf", 5> + iat-claim-label = JC<"iat", 6> + cti-claim-label = CBOR-ONLY<7> ; jti in JWT: different name and text + + JSON-ONLY = J .feature "json" + CBOR-ONLY = C .feature "cbor" + + ; Be sure to have cddl 0.8.29 or higher for this to work + JC = JSON-ONLY / CBOR-ONLY + +; A JWT message is either a JWS or JWE in compact serialization form +; with the payload a Claims-Set. Compact serialization is the +; protected headers, payload and signature, each b64url encoded and +; separated by a ".". This CDDL simply matches top-level syntax of of +; a JWS or JWE since it is not possible to do more in CDDL. + +JWT-Message = text .regexp "[A-Za-z0-9_=-]+\.[A-Za-z0-9_=-]+\.[A-Za-z0-9_=-]+" + +; Note that the payload of a JWT is defined in claims-set.cddl. That +; definition is common to CBOR and JSON. + + ; This is some CDDL describing a CWT at the top level This is + ; not normative. RFC 8392 is the normative definition of CWT. + + CWT-Messages = CWT-Tagged-Message / CWT-Untagged-Message + + ; The payload of the COSE_Message is always a Claims-Set + + ; The contents of a CWT Tag must always be a COSE tag + CWT-Tagged-Message = #6.61(COSE_Tagged_Message) + + ; An untagged CWT may be a COSE tag or not + CWT-Untagged-Message = COSE_Messages + +Appendix E. Changes from Previous Drafts The following is a list of known changes from the previous drafts. This list is non-authoritative. It is meant to help reviewers see the significant differences. -D.1. From draft-rats-eat-01 +E.1. From draft-rats-eat-01 o Added UEID design rationale appendix -D.2. From draft-mandyam-rats-eat-00 +E.2. From draft-mandyam-rats-eat-00 This is a fairly large change in the orientation of the document, but no new claims have been added. o Separate information and data model using CDDL. o Say an EAT is a CWT or JWT o Use a map to structure the boot_state and location claims -D.3. From draft-ietf-rats-eat-01 +E.3. From draft-ietf-rats-eat-01 o Clarifications and corrections for OEMID claim o Minor spelling and other fixes + o Add the nonce claim, clarify jti claim -D.4. From draft-ietf-rats-eat-02 +E.4. From draft-ietf-rats-eat-02 o Roll all EUIs back into one UEID type o UEIDs can be one of three lengths, 128, 192 and 256. o Added appendix justifying UEID design and size. o Submods part now includes nested eat tokens so they can be named and there can be more tha one of them o Lots of fixes to the CDDL o Added security considerations -D.5. From draft-ietf-rats-eat-03 +E.5. From draft-ietf-rats-eat-03 o Split boot_state into secure-boot and debug-disable claims o Debug disable is an enumerated type rather than Booleans -D.6. From draft-ietf-rats-eat-04 +E.6. From draft-ietf-rats-eat-04 o Change IMEI-based UEIDs to be encoded as a 14-byte string o CDDL cleaned up some more o CDDL allows for JWTs and UCCSs o CWT format submodules are byte string wrapped o Allows for JWT nested in CWT and vice versa @@ -4153,66 +4444,66 @@ o Rename debug-disable to debug-status; clarify that it is not extensible o Security level claim is not extensible o Improve specification of location claim and added a location privacy section o Add intended use claim -D.7. From draft-ietf-rats-eat-05 +E.7. From draft-ietf-rats-eat-05 o CDDL format issues resolved o Corrected reference to Location Privacy section -D.8. From draft-ietf-rats-eat-06 +E.8. From draft-ietf-rats-eat-06 o Added boot-seed claim o Rework CBOR interoperability section o Added profiles claim and section -D.9. From draft-ietf-rats-eat-07 +E.9. From draft-ietf-rats-eat-07 o Filled in IANA and other sections for possible preassignment of Claim Keys for well understood claims -D.10. From draft-ietf-rats-eat-08 +E.10. From draft-ietf-rats-eat-08 o Change profile claim to be either a URL or an OID rather than a test string -D.11. From draft-ietf-rats-eat-09 +E.11. From draft-ietf-rats-eat-09 o Add SUEIDs o Add appendix comparing IDevID to EAT o Added section on use for Evidence and Attestation Results o Fill in the key ID and endorsements identificaiton section o Remove origination claim as it is replaced by key IDs and endorsements o Added manifests and software evidence claims o Add string labels non-claim labels for use with JSON (e.g. labels for members of location claim) o EAN-13 HW versions are no longer a separate claim. Now they are folded in as a CoSWID version scheme. -D.12. From draft-ietf-rats-eat-10 +E.12. From draft-ietf-rats-eat-10 o Hardware version is made into an array of two rather than two claims o Corrections and wording improvements for security levels claim o Add swresults claim o Add dloas claim - Digitial Letter of Approvals, a list of certifications @@ -4242,30 +4533,30 @@ o Clearly separate CDDL for JSON and CBOR-specific data items o Define UJCS (unsigned JWTs) o Add CDDL for a general Claims-Set used by UCCS, UJCS, CWT, JWT and EAT o Top level CDDL for CWT correctly refers to COSE o OEM ID is specifically for HW, not for SW + o HW OEM ID can now be a PEN o HW OEM ID can now be a 128-bit random number - o Expand the examples section o Add software and version claims as easy / JSON alternative to CoSWID -D.13. From draft-ietf-rats-eat-11 +E.13. From draft-ietf-rats-eat-11 o Add HW model claim o Change reference for CBOR OID draft to RFC 9090 o Correct the iat claim in some examples o Make HW Version just one claim rather than 3 (device, board and chip) @@ -4284,20 +4575,68 @@ o Improve wording in submodules section, particularly how to distinguish types when decoding o Remove security-level from early allocation o Add boot odometer claim o Add privacy considerations for replay protection +E.14. From draft-ietf-rats-eat-12 + + o Make use of the JC<> generic to express CDDL for both JSON and + CBOR + + o Reorganize claims into 4 sections, particularly claims about the + entity and about the token + + o Nonce wording - say nonce is required and other improvements + o Clarify relationship of claims in evidence to results when + forwarding + + o Clarify manufacturer switching UEID types + + o Add new section on the top-level token type that has CBOR-specific + and JSON-specific CDDL since the top-level can't be handled with + JC<> + + o Remove definition of UCCS and UJCS, replacing it with a CDDL + socket and mention of future token types + + o Split the examples into payload and top level tokens since UCCS + can't be used for examples any more (It was nice because you could + see the payload claims in it easily, where you can't with CWT) + + o DEB tag number is TBD rather than hard coded + + o Add appendix with non-normative CDDL for a Claims-Set, CWT and JWT + + o (Large reorganization of the document build and example + verification makefile) + + o Use CoAP content format ID to distinguish manifest and evidence + formats instead of CBOR tag + + o Added more examples, both CBOR and JSON + + o All CDDL is validating against all examples + + o Unassigned IANA requests are clearly TBD in the document (and have + real values as is necessary in the example validation process) + + o Improve security-level claim + + o swresults claim is now measurement results claim + + o substantial redesign of measurement results claim + Authors' Addresses Laurence Lundblade Security Theory LLC EMail: lgl@securitytheory.com Giridhar Mandyam Qualcomm Technologies Inc. 5775 Morehouse Drive San Diego, California