Arm's Platform Security Architecture (PSA) Attestation Token
draft-tschofenig-rats-psa-token-05

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RATS                                                       H. Tschofenig
Internet-Draft                                                  S. Frost
Intended status: Informational                               M. Brossard
Expires: 7 September 2020                                        A. Shaw
                                                              T. Fossati
                                                             Arm Limited
                                                            6 March 2020

      Arm's Platform Security Architecture (PSA) Attestation Token
                   draft-tschofenig-rats-psa-token-05

Abstract

   The Platform Security Architecture (PSA) is a family of hardware and
   firmware security specifications, as well as open-source reference
   implementations, to help device makers and chip manufacturers build
   best-practice security into products.  Devices that are PSA compliant
   are able to produce attestation tokens as described in this memo,
   which are the basis for a number of different protocols, including
   secure provisioning and network access control.  This document
   specifies the PSA attestation token structure and semantics.

   At its core, the CWT (COSE Web Token) format is used and populated
   with a set of claims in a way similar to EAT (Entity Attestation
   Token).  This specification describes what claims are used by PSA
   compliant systems.

Note to Readers

   Source for this draft and an issue tracker can be found at
   https://github.com/thomas-fossati/draft-psa-token
   (https://github.com/thomas-fossati/draft-psa-token).

Status of This Memo

   This Internet-Draft is submitted in full conformance with the
   provisions of BCP 78 and BCP 79.

   Internet-Drafts are working documents of the Internet Engineering
   Task Force (IETF).  Note that other groups may also distribute
   working documents as Internet-Drafts.  The list of current Internet-
   Drafts is at https://datatracker.ietf.org/drafts/current/.

   Internet-Drafts are draft documents valid for a maximum of six months
   and may be updated, replaced, or obsoleted by other documents at any
   time.  It is inappropriate to use Internet-Drafts as reference
   material or to cite them other than as "work in progress."

Tschofenig, et al.      Expires 7 September 2020                [Page 1]
Internet-Draft            PSA Attestation Token               March 2020

   This Internet-Draft will expire on 7 September 2020.

Copyright Notice

   Copyright (c) 2020 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents (https://trustee.ietf.org/
   license-info) in effect on the date of publication of this document.
   Please review these documents carefully, as they describe your rights
   and restrictions with respect to this document.  Code Components
   extracted from this document must include Simplified BSD License text
   as described in Section 4.e of the Trust Legal Provisions and are
   provided without warranty as described in the Simplified BSD License.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   3
   2.  Conventions and Definitions . . . . . . . . . . . . . . . . .   3
     2.1.  Glossary  . . . . . . . . . . . . . . . . . . . . . . . .   3
   3.  PSA Claims  . . . . . . . . . . . . . . . . . . . . . . . . .   4
     3.1.  Caller Claims . . . . . . . . . . . . . . . . . . . . . .   4
       3.1.1.  Auth Challenge  . . . . . . . . . . . . . . . . . . .   4
       3.1.2.  Client ID . . . . . . . . . . . . . . . . . . . . . .   4
     3.2.  Target Identification Claims  . . . . . . . . . . . . . .   5
       3.2.1.  Instance ID . . . . . . . . . . . . . . . . . . . . .   5
       3.2.2.  Implementation ID . . . . . . . . . . . . . . . . . .   5
       3.2.3.  Hardware Version  . . . . . . . . . . . . . . . . . .   6
     3.3.  Target State Claims . . . . . . . . . . . . . . . . . . .   6
       3.3.1.  Security Lifecycle  . . . . . . . . . . . . . . . . .   6
       3.3.2.  Boot Seed . . . . . . . . . . . . . . . . . . . . . .   8
     3.4.  Software Inventory Claims . . . . . . . . . . . . . . . .   8
       3.4.1.  Software Components . . . . . . . . . . . . . . . . .   8
       3.4.2.  No Software Measurements  . . . . . . . . . . . . . .  10
     3.5.  Verification Claims . . . . . . . . . . . . . . . . . . .  10
       3.5.1.  Verification Service Indicator  . . . . . . . . . . .  10
       3.5.2.  Profile Definition  . . . . . . . . . . . . . . . . .  11
   4.  Token Encoding and Signing  . . . . . . . . . . . . . . . . .  11
   5.  Collated CDDL . . . . . . . . . . . . . . . . . . . . . . . .  11
   6.  Security and Privacy Considerations . . . . . . . . . . . . .  14
   7.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  14
   8.  References  . . . . . . . . . . . . . . . . . . . . . . . . .  14