Secure Reporting of Update Status
draft-ietf-suit-report-13

SUIT                                                            B. Moran
Internet-Draft                                               Arm Limited
Intended status: Informational                               H. Birkholz
Expires: 8 January 2026                                   Fraunhofer SIT
                                                             7 July 2025

                   Secure Reporting of Update Status
                       draft-ietf-suit-report-13

Abstract

   The Software Update for the Internet of Things (SUIT) manifest
   provides a way for many different update and boot workflows to be
   described by a common format.  This specification describes a
   lightweight feedback mechanism that allows a developer in possession
   of a manifest to reconstruct the decisions made and actions performed
   by a manifest processor.

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."

   This Internet-Draft will expire on 8 January 2026.

Copyright Notice

   Copyright (c) 2025 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

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   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 Revised BSD License text as
   described in Section 4.e of the Trust Legal Provisions and are
   provided without warranty as described in the Revised BSD License.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Conventions and Terminology . . . . . . . . . . . . . . . . .   3
   3.  The SUIT_Record . . . . . . . . . . . . . . . . . . . . . . .   3
   4.  The SUIT_Report . . . . . . . . . . . . . . . . . . . . . . .   6
     4.1.  SUIT_Report_Records . . . . . . . . . . . . . . . . . . .   7
     4.2.  SUIT_Report Result  . . . . . . . . . . . . . . . . . . .   8
   5.  Attestation . . . . . . . . . . . . . . . . . . . . . . . . .   9
   6.  Capability Reporting  . . . . . . . . . . . . . . . . . . . .  11
   7.  EAT Claim . . . . . . . . . . . . . . . . . . . . . . . . . .  12
   8.  SUIT_Report Container . . . . . . . . . . . . . . . . . . . .  12
   9.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  13
     9.1.  Expert Review Instructions  . . . . . . . . . . . . . . .  14
     9.2.  Media Type Registration . . . . . . . . . . . . . . . . .  15
       9.2.1.  application/suit-report+cose  . . . . . . . . . . . .  15
     9.3.  CoAP Content-Format Registration  . . . . . . . . . . . .  15
     9.4.  CBOR Tag Registration . . . . . . . . . . . . . . . . . .  16
     9.5.  SUIT_Report Elements  . . . . . . . . . . . . . . . . . .  16
     9.6.  SUIT_Record Elements  . . . . . . . . . . . . . . . . . .  17
     9.7.  SUIT_Report Reasons . . . . . . . . . . . . . . . . . . .  17
     9.8.   SUIT Capability Report Elements  . . . . . . . . . . . .  18
   10. Security Considerations . . . . . . . . . . . . . . . . . . .  19
   11. Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .  20
   12. References  . . . . . . . . . . . . . . . . . . . . . . . . .  20
     12.1.  Normative References . . . . . . . . . . . . . . . . . .  21
     12.2.  Informative References . . . . . . . . . . . . . . . . .  21
   Appendix A.  Full CDDL  . . . . . . . . . . . . . . . . . . . . .  22
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  25

1.  Introduction

   This specification describes a SUIT-specific logging container that
   creates a lightweight feedback mechanism for developers in the event
   that an update or boot fails in the manifest processor.

   A SUIT manifest processor can fail to install or boot an update for
   many reasons.  Frequently, the error codes generated by such systems
   fail to provide developers with enough information to find root

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   causes and produce corrective actions, resulting in extra effort to
   reproduce failures.  Logging the results of each SUIT command can
   simplify this process.

   While it is possible to report the results of SUIT commands through
   existing logging or attestation mechanisms, this comes with several
   drawbacks:

   *  data inflation, particularly when designed for text-based logging

   *  missing information elements

   *  missing support for multiple components

   The CBOR objects defined in this document allow devices to:

   *  report a trace of how an update was performed

   *  report expected vs. actual values for critical checks

   *  describe the installation of complex multi-component architectures

   *  describe the measured properties of a system

   *  report the exact reason for a parsing failure

2.  Conventions and 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.

   Terms used in this specification include:

   *  Boot: initialization of an executable image.  Although this
      specification refers to boot, any boot-specific operations
      described are equally applicable to starting an executable in an
      OS context.

3.  The SUIT_Record

   If the developer has a copy of the manifest, then they need little
   information to reconstruct what the manifest processor has done.
   They simply need any data that influences the control flow of the
   manifest.  The manifest only supports the following control flow
   primitives:

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   *  Set Component

   *  Set/Override Parameters

   *  Try-Each

   *  Run Sequence

   *  Conditions

   Of these, only conditions change the behavior of the processor from
   the default, and then only when the condition fails.

   To reconstruct the flow of a manifest, a developer needs a list of
   metadata about failed conditions:

   *  the current manifest

   *  the current section

   *  the offset into the current section

   *  the current component index

   *  the "reason" for failure

   Most conditions compare a parameter to an actual value, so the
   "reason" is typically the actual value.

   Since it is possible that a non-condition command (directive) may
   fail in an exceptional circumstance, a failure code for a non
   condition command must be included as well.  However, a failed
   directive will terminate processing of the manifest.  To accommodate
   for a failed command and for explicit "completion," an additional
   "result" element is included as well, however this is included in the
   SUIT_Report, see Section 4.  In the case of a command failure, the
   failure reason is typically a numeric error code.  However, these
   error codes need to be standardised in order to be useful.

   This approach effectively compacts the log of operations taken using
   the SUIT Manifest as a dictionary.  This enables a full
   reconstruction of the log using a matching decompaction tool.

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   SUIT_Record = [
       suit-record-manifest-id        : [* uint ],
       suit-record-manifest-section   : int,
       suit-record-section-offset     : uint,
       suit-record-component-index    : uint,
       suit-record-properties         : SUIT_Parameters,
       $$SUIT_Record_Extensions
   ]

   suit-record-manifest-id is used to identify which manifest contains
   the command that caused the record to be generated.  The manifest id
   is a list of integers that form a walk of the manifest tree, starting
   at the root.  An empty list indicates that the command was contained
   in the root manifest.  If the list is not empty, the command was
   contained in one of the root manifest's dependencies, or nested even
   further below that.

   For example, suppose that the root manifest has 3 dependencies and
   each of those dependencies has 2 dependencies of its own:

   *  Root

      -  Dependency A (index 0)

         o  Dependency AA (index 0,0)

         o  Dependency AB (index 0,1)

      -  Dependency B (index 1)

         o  Dependency BA (index 1,0)

         o  Dependency BB (index 1,1)

      -  Dependency C (index 2)

         o  Dependency CA (index 2,0)

         o  Dependency CB (index 2,1)

   A manifest-id of [1,0] would indicate that the current command was
   contained within Dependency BA.  Similarly, a manifest-id of [2,1]
   would indicate Dependency CB

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   suit-record-manifest-section indicates which section of the manifest
   was active.  This is used in addition to an offset so that the
   developer can index into severable sections in a predictable way.
   The value of this element is the value of the key that identified the
   section in the manifest.

   suit-record-section-offset is the number of bytes into the current
   section at which the current command is located.

   suit-record-component-index is the index of the component that was
   specified at the time that the report was generated.  This field is
   necessary due to the availability of set-current-component values of
   True and a list of components.  Both of these values cause the
   manifest processor to loop over commands using a series of component-
   ids, so the developer needs to know which was selected when the
   command executed.

   suit-record-properties contains any measured properties that led to
   the command failure.  For example, this could be the actual value of
   a SUIT_Digest or class identifier.  This is encoded in a
   SUIT_Parameters block as defined in [I-D.ietf-suit-manifest].

4.  The SUIT_Report

   Some metadata is common to all records, such as the root manifest:
   the manifest that is the entry-point for the manifest processor.
   This metadata is aggregated with a list of SUIT_Records.  The
   SUIT_Report may also contain a list of any system properties that
   were measured and reported, and a reason for a failure if one
   occurred.

   SUIT_Report = {
     suit-reference              => SUIT_Reference,
     ? suit-report-nonce         => bstr,
     suit-report-records         => \
           \[ * SUIT_Record / system-property-claims \],
     suit-report-result          => true / {
       suit-report-result-code   => int,
       suit-report-result-record => SUIT_Record,
       suit-report-result-reason => SUIT_Report_Reasons,
     },
     ? suit-report-capability-report => SUIT_Capability_Report,
     $$SUIT_Report_Extensions
   }
   system-property-claims = {
     system-component-id => SUIT_Component_Identifier,
     + SUIT_Parameters,
   }

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   The suit-reference provides a reference URI and digest for a suit
   manifest.  The URI MUST be the canonical URI that is provided in the
   manifest.  The digest is the digest of the manifest.

   NOTE: The digest is used in preference to other identifiers in the
   manifest because it allows a manifest to be uniquely identified
   (collision resistance) whereas other identifiers, such as the
   sequence number, can collide, particularly in scenarios with multiple
   trusted signers.

   The following CDDL describes a SUIT_Reference.

   SUIT_Reference = {
       suit-report-manifest-uri  : tstr,
       suit-report-manifest-digest : SUIT_Digest,
   }

   suit-report-manifest-digest provides a SUIT_Digest (as defined in
   [I-D.ietf-suit-manifest]) that is the characteristic digest of the
   Root manifest.

   suit-report-manifest-uri provides the reference URI that was provided
   in the root manifest.

   suit-report-nonce provides a container for freshness or replay
   protection information.  This field MAY be omitted where the suit-
   report is authenticated within a container that provides freshness
   already.  For example, attestation evidence typically contains a
   proof of freshness.

4.1.  SUIT_Report_Records

   suit-report-records is a list of 0 or more SUIT_Records or system-
   property-claims.  Because SUIT_Records are only generated on failure,
   in simple cases this can be an empty list.  SUIT_Records and suit-
   system-property-claims are merged into a single list because this
   reduces the overhead for a constrained node that generates this
   report.  The use of a single append-only log allows report generators
   to use simple memory management.  The concept of append-only logs for
   software supply chains is explained in [I-D.ietf-scitt-architecture].
   Because the system-property-claims are encoded as maps and
   SUIT_Records are encoded as lists, a recipient need only filter the
   CBOR Type-5 entries from suit-report-records to obtain all system-
   property-claims.

   System Properties can be extracted from suit-report-records by
   filtering suit-report-records for maps.  System Properties are a list
   of measured or asserted properties of the system that creates the

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   SUIT_Report.  These properties are scoped by component identifier.
   Because this list is expected to be constructed on the fly by a
   constrained node, component identifiers may appear more than once.  A
   recipient may convert the result to a more conventional structure:

   SUIT_Record_System_Properties = {
     * component-id => {
       + SUIT_Parameters,
     }
   }

4.2.  SUIT_Report Result

   suit-report-result provides a mechanism to show that the SUIT
   procedure completed successfully (value is true) or why it failed
   (value is a map of an error code and a SUIT_Record).

   suit-report-result-reason gives a high-level explanation of the
   failure.  These reasons are intended for interoperable
   implementations.  The reasons are divided into a small number of
   groups:

   *  suit-report-reason-cbor-parse: a parsing error was encountered by
      the CBOR parser.

   *  suit-report-reason-cose-unsupported: an unusupported COSE
      structure or header was encountered.

   *  suit-report-reason-alg-unsupported: an unsupported COSE algorithm
      was encountered.

   *  suit-report-reason-unauthorised: Signature/MAC verification
      failed.

   *  suit-report-reason-command-unsupported: an unsupported command was
      encountered.

   *  suit-report-reason-component-unsupported: The manifest declared a
      component/prefix that does not exist.

   *  suit-report-reason-component-unauthorised: The manifest declared a
      component that is not accessible by the signer.

   *  suit-report-reason-parameter-unsupported: The manifest used a
      parameter that does not exist.

   *  suit-report-severing-unsupported: The manifest uses severable
      fields but the Manifest Processor doesn't support them.

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   *  suit-report-reason-condition-failed: A condition failed with soft-
      failure off.

   *  suit-report-reason-operation-failed: A command failed (e.g.,
      download/copy/swap/write)

   The suit-report-result-code reports an internal error code that is
   provided for debugging reasons.  This code is not intended for
   interoperability.

   The suit-report-result-record indicates the exact point in the
   manifest or manifest dependency tree where the error occurred.

   suit-report-capability-report provides a mechanism to report the
   capabilities of the Manifest Processor.  The SUIT_Capability_Report
   is described in Section 6.  The capability report is optional to
   include in the SUIT_Report, according to an application-specific
   policy.  While the SUIT_Capability_Report is not expected to be very
   large, applications should ensure that they only report capabilities
   when necessary in order to conserve bandwidth.  A capability report
   is not necessary except when:

   1.  A client explicitly requests the capability report, or

   2.  A manifest attempts to use a capability that the Manifest
       Processor does not implement.

5.  Attestation

   Where Remote Attestation (see [RFC9334], the RATS Architecture) is in
   use, the RATS Verifier (Verifier hereafter) requires a set of
   Attestation Evidence.  Attestation Evidence contains Evidence Claims
   about the Attester.  These Evidence Claims contain measurements about
   the Attester.  Many of these measurements are the same measurements
   that are generated in SUIT, which means that a SUIT_Report contains
   most of the Claims and some of the Endorsements that a Verifier
   requires.

   Using a SUIT_Manifest and a SUIT_Report, improves a well-informed
   Verifier's ability to appraise the trustworthiness of a remote
   device.  Remote attestation is done by using the
   SUIT_Manifest_Envelope along with the SUIT_Report to reconstruct the
   state of the device at boot time.  By embedding data used for remote
   attestation in the SUIT_Report, a remote device can use a verifiable
   data structure, such as an append-only log, to notarize both
   measurements and debug/failure information via the same document.
   This document can then be conveyed to a Verifier as a part of the
   Attestation Evidence.  A Remote Attestation format to convey

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   Attestation Evidence, such as an Entity Attestation Token (EAT, see
   [RFC9711]), that contains a SUIT_Report MUST also include an
   integrity measurement of the Manifest Processor & Report Generator.

   When a Concise Reference Integrity Manifest (CoRIM, see
   [I-D.birkholz-rats-corim]) is delivered in a SUIT_Manifest_Envelope,
   this codifies the delivery of appraisal information to the Verifier:

   *  The Firmware Distributor:

      -  sends the SUIT_Manifest_Envelope to the Verifier without
         payload or text, but with CoRIM

      -  sends the SUIT_Manifest_Envelope to the recipient without
         CoRIM, or text, but with payload

   *  The Recipient:

      -  Installs the firmware as described in the SUIT_Manifest and
         generates a SUIT_report, which is encapsulated in an EAT by the
         installer and sent to the Firmware Distributor.

      -  Boots the firmware as described in the SUIT_Manifest and
         creates a SUIT_report, which is encapsulated in an EAT by the
         installer and sent to the Firmware Distributor.

   *  The Firmware Distributor sends both reports to the Verifier
      (separately or together)

   *  The Verifier:

      -  Reconstructs the state of the device using the manifest

      -  Compares this state to the CoRIM

      -  Returns an Attestation Report to the Firmware Distributor

   This approach simplifies the design of the bootloader since it is
   able to use an append-only log.  It allows a Verifier to validate
   this report against a signed CoRIM that is provided by the firmware
   author, which simplifies the delivery chain of verification
   information to the Verifier.

   This information is not intended as Attestation Evidence and while an
   Attestation Report MAY provide this information for conveying error
   codes and/or failure reports, it SHOULD be translated into general-
   purpose claims for use by the Relying Party.

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6.  Capability Reporting

   Because SUIT is extensible, a manifest author must know what
   capabilities a device has available.  To enable this, a capability
   report is a set of lists that define which commands, parameters,
   algorithms, and component IDs are supported by a manifest processor.

   The CDDL for a SUIT_Capability_Report follows:

   SUIT_Capability_Report = {
     suit-component-capabilities  => [+ SUIT_Component_Capability ]
     suit-command-capabilities          => [+ int],
     suit-parameters-capabilities       => [+ int],
     suit-crypt-algo-capabilities       => [+ int],
     ? suit-envelope-capabilities       => [+ int],
     ? suit-manifest-capabilities       => [+ int],
     ? suit-common-capabilities         => [+ int],
     ? suit-text-capabilities           => [+ int],
     ? suit-text-component-capabilities => [+ int],
     ? suit-dependency-capabilities     => [+ int],
     * [+int]                           => [+ int],
     $$SUIT_Capability_Report_Extensions
   }

   SUIT_Component_Capability = [*bstr,?true]

   A SUIT_Component_Capability is similar to a SUIT_Component_ID, with
   one difference: it may optionally be terminated by a CBOR 'true'
   which acts as a wild-card match for any component with a prefix
   matching the SUIT_Component_Capability leading up to the 'true.'
   This feature is for use with filesystem storage, key value stores, or
   any other arbitrary-component-id storage systems.

   When reporting capabilities, it is OPTIONAL to report capabilities
   that are declared mandatory by the SUIT Manifest
   [I-D.ietf-suit-manifest].  Capabilities defined by extensions MUST be
   reported.

   Additional capability reporting can be added as follows: if a
   manifest element does not exist in this map, it can be added by
   specifying the CBOR path to the manifest element in an array and
   using this as the key.  For example SUIT_Dependencies, as described
   in [I-D.ietf-suit-trust-domains] could have an extension added, which
   was key 3 in the SUIT_Dependencies map.  This capability would be
   reported as: [3, 3, 1] => [3], where the key consists of the key for
   SUIT_Manifest (3), the key for SUIT_Common (3), and the key for
   SUIT_Dependencies (1).  Then the value indicates that this manifest
   processor supports the extension (3).

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7.  EAT Claim

   The SUIT_Report is a form of measurement done by the SUIT Manifest
   Processor as it attempts to invoke a manifest or install a manifest.
   As a result, the SUIT_Report can be captured in an EAT measurements
   type.  The Verifier MAY convert a SUIT_Report into a more consumable
   version of the EAT claim by, for example, constructing a measurement
   results claim that contains the digest of a component, the vendor ID
   & class ID of a component, etc.

8.  SUIT_Report Container

   The SUIT_Report MUST be transported using one of the following
   methods:

   *  As part of a larger document that provides authenticity
      guarantees, such as within a measurements claim in an Entity
      Attestation Token (EAT [RFC9711]).

   *  As the payload of a message transmitted over a communication
      security protocol, such as DTLS [RFC9147].

   *  Encapsulated within a secure container, such as a COSE structure.
      In the case of COSE, the container MUST be either a COSE_Encrypt0
      or COSE_Sign1 structure.  The SUIT_Report MUST be the sole
      payload, as illustrated by the CDDL fragment below.

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   SUIT_Report_Protected /= SUIT_Report_COSE_Sign1 \
                            .and SUIT_COSE_Profiles
   SUIT_Report_Protected /= SUIT_Report_COSE_Sign1_Tagged \
                            .and SUIT_COSE_Profiles
   SUIT_Report_Protected /= SUIT_Report_COSE_MAC0 \
                            .and SUIT_COSE_Profiles
   SUIT_Report_Protected /= SUIT_Report_COSE_MAC0_Tagged \
                            .and SUIT_COSE_Profiles

   SUIT_Report_COSE_Sign1_Tagged = #6.18(SUIT_Report_COSE_Sign1)
   SUIT_Report_COSE_Sign1 = [
       protected : bstr,
       unprotected : {* int => any},
       payload : bstr .cbor SUIT_Report_Unprotected,
       signature : bstr
   ]
   SUIT_Report_COSE_MAC0_Tagged = #6.17(SUIT_Report_COSE_MAC0)
   SUIT_Report_COSE_MAC0 = [
       protected : bstr,
       unprotected : {* int => any},
       payload : bstr .cbor SUIT_Report_Unprotected,
       tag : bstr
   ]
   SUIT_Report_Unprotected = SUIT_Report / SUIT_Report_COSE_Encrypt0
   SUIT_Report_COSE_Encrypt0 = COSE_Encrypt0

   Note that SUIT_Report_COSE_Sign1 and SUIT_Report_COSE_MAC0 MUST be
   combined with a SUIT_COSE_Profile from [I-D.ietf-suit-mti] using the
   CDDL .and directive.  The SUIT_Report_COSE_Encrypt0 carries a
   ciphertext payload that MUST contain just the ciphertext obtained by
   encrypting the following CDDL:

   SUIT_Report_plaintext = bstr .cbor SUIT_Report

   SUIT_COSE_Profiles, which use AES-CTR encryption, are not integrity
   protected and authenticated.  For this purpose, SUIT_Report_Protected
   defines authenticated containers with an encrypted payload.

9.  IANA Considerations

   IANA is requested to name the overall SUIT registry group "Software
   Update for the Internet of Things (SUIT)".

   IANA is requested to allocate a CBOR tag for each of:

   *  SUIT_Report_Protected

   *  SUIT_Reference

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   *  SUIT_Capability_Report

   IANA is requested to allocate a CoAP content-type [RFC7252] and a
   media-type for SUIT_Report.

   IANA is also requested to add the following registries to the SUIT
   registry group:

   *  SUIT_Report Elements

   *  SUIT_Record Elements

   *  SUIT_Report Reasons

   *  SUIT Capability Report Elements

   For each of these registries, registration policy is:

   *  -256 to 255: Standards Action

   *  -65536 to 257, 256 to 65535: Specification Required

   *  -4294967296 to -65537, 65536 to 4294967295: First Come, First
      Served

9.1.  Expert Review Instructions

   The IANA registries established in this document allow values to be
   added based on expert review.  This section gives some general
   guidelines for what the experts should be looking for, but they are
   being designated as experts for a reason, so they should be given
   substantial latitude.

   Expert reviewers should take into consideration the following points:

   *  Point squatting should be discouraged.  Reviewers are encouraged
      to get sufficient information for registration requests to ensure
      that the usage is not going to duplicate one that is already
      registered, and that the point is likely to be used in
      deployments.  The zones tagged as private use are intended for
      testing purposes and closed environments; code points in other
      ranges should not be assigned for testing.

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   *  Specifications are required for the standards track range of point
      assignment.  Specifications should exist for all other ranges, but
      early assignment before a specification is available is considered
      to be permissible.  When specifications are not provided, the
      description provided needs to have sufficient information to
      identify what the point is being used for.

   *  Experts should take into account the expected usage of fields when
      approving point assignment.  The fact that there is a range for
      standards track documents does not mean that a standards track
      document cannot have points assigned outside of that range.  The
      length of the encoded value should be weighed against how many
      code points of that length are left, the size of device it will be
      used on, and the number of code points left that encode to that
      size.

9.2.  Media Type Registration

9.2.1.  application/suit-report+cose

   Type name:  application
   Subtype name:  suit-report+cose
   Required parameters:  n/a
   Encoding considerations:  binary (CBOR)
   Security considerations:  Section 10 of RFCthis
   Interoperability considerations:  n/a
   Published specification:  RFCthis
   Applications that use this media type:  SUIT Manifest Processor, SUIT
      Manifest Distributor, SUIT Manifest Author, RATS Attesters, RATS
      Verifiers
   Fragment identifier considerations:  The syntax and semantics of
      fragment identifiers are as specified for "application/cose".
   Person & email address to contact for further information:  SUIT WG
      mailing list (suit@ietf.org)
   Intended usage:  COMMON
   Restrictions on usage:  none
   Author/Change controller:  IETF
   Provisional registration:  no

9.3.  CoAP Content-Format Registration

   IANA is requested to assign a CoAP Content-Format ID for the CoSWID
   media type in the "CoAP Content-Formats" sub-registry, from the "IETF
   Review or IESG Approval" space (256..999), within the "CoRE
   Parameters" registry [RFC7252] [IANA.core-parameters]:

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      +==============================+===========+=====+===========+
      | Media type                   | Encoding  | ID  | Reference |
      +==============================+===========+=====+===========+
      | application/suit-report+cose | cbor+cose | TBA | RFCthis   |
      +------------------------------+-----------+-----+-----------+

                                 Table 1

9.4.  CBOR Tag Registration

   IANA is requested to allocate a tag in the "CBOR Tags" registry
   [IANA.cbor-tags], preferably in the Specification Required range:

               +=====+===========+========================+
               | Tag | Data Item | Semantics              |
               +=====+===========+========================+
               | TBA | array     | SUIT_Report_Protected  |
               +-----+-----------+------------------------+
               | TBA | map       | SUIT_Reference         |
               +-----+-----------+------------------------+
               | TBA | map       | SUIT_Capability_Report |
               +-----+-----------+------------------------+

                                 Table 2

9.5.  SUIT_Report Elements

   IANA is requested to create a new registry for SUIT_Report Elements.

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                 +=======+===================+===========+
                 | Label | Name              | Reference |
                 +=======+===================+===========+
                 | 2     | Nonce             | Section 4 |
                 +-------+-------------------+-----------+
                 | 3     | Records           | Section 4 |
                 +-------+-------------------+-----------+
                 | 4     | Result            | Section 4 |
                 +-------+-------------------+-----------+
                 | 5     | Result Code       | Section 4 |
                 +-------+-------------------+-----------+
                 | 6     | Result Record     | Section 4 |
                 +-------+-------------------+-----------+
                 | 7     | Result Reason     | Section 4 |
                 +-------+-------------------+-----------+
                 | 8     | Capability Report | Section 4 |
                 +-------+-------------------+-----------+
                 | 99    | Reference         | Section 4 |
                 +-------+-------------------+-----------+

                                  Table 3

9.6.  SUIT_Record Elements

   IANA is requested to create a new registry for SUIT_Record Elements.

                 +=======+===================+===========+
                 | Label | Name              | Reference |
                 +=======+===================+===========+
                 | 0     | Manifest ID       | Section 3 |
                 +-------+-------------------+-----------+
                 | 1     | Manifest Section  | Section 3 |
                 +-------+-------------------+-----------+
                 | 2     | Section Offset    | Section 3 |
                 +-------+-------------------+-----------+
                 | 3     | Component Index   | Section 3 |
                 +-------+-------------------+-----------+
                 | 4     | Dependency Index  | Section 3 |
                 +-------+-------------------+-----------+
                 | 5     | Record Properties | Section 3 |
                 +-------+-------------------+-----------+

                                  Table 4

9.7.  SUIT_Report Reasons

   IANA is requested to create a new registry for SUIT_Report Reasons.

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      +=======+======================================+=============+
      | Label | Name                                 | Reference   |
      +=======+======================================+=============+
      | 0     | Result OK                            | Section 4.2 |
      +-------+--------------------------------------+-------------+
      | 1     | CBOR Parse Failure                   | Section 4.2 |
      +-------+--------------------------------------+-------------+
      | 2     | Unsupported COSE Structure or Header | Section 4.2 |
      +-------+--------------------------------------+-------------+
      | 3     | Unsupported COSE Algorithm           | Section 4.2 |
      +-------+--------------------------------------+-------------+
      | 4     | Signature / MAC verification failed  | Section 4.2 |
      +-------+--------------------------------------+-------------+
      | 5     | Unsupported SUIT Command             | Section 4.2 |
      +-------+--------------------------------------+-------------+
      | 6     | Unsupported SUIT Component           | Section 4.2 |
      +-------+--------------------------------------+-------------+
      | 7     | Unauthorized SUIT Component          | Section 4.2 |
      +-------+--------------------------------------+-------------+
      | 8     | Unsupported SUIT Parameter           | Section 4.2 |
      +-------+--------------------------------------+-------------+
      | 9     | Severing Unsupported                 | Section 4.2 |
      +-------+--------------------------------------+-------------+
      | 10    | Condition Failed                     | Section 4.2 |
      +-------+--------------------------------------+-------------+
      | 11    | Operation Failed                     | Section 4.2 |
      +-------+--------------------------------------+-------------+

                                 Table 5

9.8.   SUIT Capability Report Elements

   IANA is requested to create a new registry for SUIT Capability Report
   Elements.

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             +=======+==========================+===========+
             | Label | Name                     | Reference |
             +=======+==========================+===========+
             | 1     | Components               | Section 6 |
             +-------+--------------------------+-----------+
             | 2     | Commands                 | Section 6 |
             +-------+--------------------------+-----------+
             | 3     | Parameters               | Section 6 |
             +-------+--------------------------+-----------+
             | 4     | Cryptographic Algorithms | Section 6 |
             +-------+--------------------------+-----------+
             | 5     | Envelope Elements        | Section 6 |
             +-------+--------------------------+-----------+
             | 6     | Manifest Elements        | Section 6 |
             +-------+--------------------------+-----------+
             | 7     | Common Elements          | Section 6 |
             +-------+--------------------------+-----------+
             | 8     | Text Elements            | Section 6 |
             +-------+--------------------------+-----------+
             | 9     | Component Text Elements  | Section 6 |
             +-------+--------------------------+-----------+

                                 Table 6

10.  Security Considerations

   The SUIT_Report serves four primary security objectives:

   *  Validated Identity

   *  Integrity

   *  Replay protection

   *  Confidentiality

   The mechanisms for achieving these protections are outlined in
   Section 8.

   Ideally, a SUIT_Report SHOULD be conveyed as part of a remote
   attestation procedure, such as embeding it in EAT tokens that
   represent RATS conceptual messages.  This approach ensures that the
   SUIT_Report is cryptographically bound to the environment (hardware,
   software, or both) in which it was generated, thereby strengthening
   its authenticity.

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   A SUIT_Report may disclose sensitive information about the device on
   which it were produced.  In such cases, the SUIT_Report MUST be
   encrypted, as specified in Section 8.

   Furthermore, failure reports, particularly those involving
   cryptographic operations, can unintentionally reveal insights into
   system weaknesses or vulnerabilities.  As such, SUIT_Reports SHOULD
   be encrypted whenever possible, to minimize the risk of information
   leakage.

   In addition to these core security requirements, operational
   considerations must be taken into account.  When a SUIT_Report is
   included within another protocol message (e.g., inside an encrypted
   EAT), care must be taken to avoid inadvertently leaking information
   and to uphold the principle of least privilege.  For example, in many
   EAT-based remote attestation flows, the Verifier may not require the
   full SUIT_Report.  Similarly, the Relying Party might not need access
   to it either.

   To support least-privilege access, the SUIT_Report should be
   independently encrypted, even when the transport or enclosing token
   is also encrypted.  This layered encryption ensures that only
   authorized entities can access the contents of the SUIT_Report.

   In other scenarios, the EAT Verifier might require full access to a
   SUIT_Report.  For example, the SUIT_Report must be accessible in its
   entirety for the EAT Verifier to extract or convert the SUIT_Report
   content into specific EAT claims, such as measres (Measurement
   Results).  A typical case involves translating a successful suit-
   condition-image check into a digest-based claim within the EAT.

   When applying cryptographic protection to the SUIT_Report, the same
   algorithm profile used for the corresponding SUIT manifest SHOULD be
   reused.  The available algorithm profiles are detailed in
   [I-D.ietf-suit-mti].  If using the same profile is not feasible
   (e.g., due to constraints imposed by suit-sha256-hsslms-a256kw-
   a256ctr), then a profile offering comparable security strength SHOULD
   be selected—for instance, suit-sha256-esp256-ecdh-a128ctr.

   In exceptional cases, if no suitable profile can be applied, the
   necessity of disabling a SUIT_Report functionality altogether might
   arise.

11.  Acknowledgements

   The authors would like to thank Dave Thaler for his feedback.

12.  References

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12.1.  Normative References

   [I-D.ietf-suit-manifest]
              Moran, B., Tschofenig, H., Birkholz, H., Zandberg, K., and
              O. Rønningstad, "A Concise Binary Object Representation
              (CBOR)-based Serialization Format for the Software Updates
              for Internet of Things (SUIT) Manifest", Work in Progress,
              Internet-Draft, draft-ietf-suit-manifest-34, 28 May 2025,
              <https://datatracker.ietf.org/doc/html/draft-ietf-suit-
              manifest-34>.

   [I-D.ietf-suit-mti]
              Moran, B., Rønningstad, O., and A. Tsukamoto,
              "Cryptographic Algorithms for Internet of Things (IoT)
              Devices", Work in Progress, Internet-Draft, draft-ietf-
              suit-mti-21, 6 July 2025,
              <https://datatracker.ietf.org/doc/html/draft-ietf-suit-
              mti-21>.

   [IANA.cbor-tags]
              IANA, "Concise Binary Object Representation (CBOR) Tags",
              <https://www.iana.org/assignments/cbor-tags>.

   [IANA.core-parameters]
              IANA, "Constrained RESTful Environments (CoRE)
              Parameters",
              <https://www.iana.org/assignments/core-parameters>.

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119,
              DOI 10.17487/RFC2119, March 1997,
              <https://www.rfc-editor.org/rfc/rfc2119>.

   [RFC8174]  Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
              2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
              May 2017, <https://www.rfc-editor.org/rfc/rfc8174>.

   [RFC9052]  Schaad, J., "CBOR Object Signing and Encryption (COSE):
              Structures and Process", STD 96, RFC 9052,
              DOI 10.17487/RFC9052, August 2022,
              <https://www.rfc-editor.org/rfc/rfc9052>.

   [RFC9711]  Lundblade, L., Mandyam, G., O'Donoghue, J., and C.
              Wallace, "The Entity Attestation Token (EAT)", RFC 9711,
              DOI 10.17487/RFC9711, April 2025,
              <https://www.rfc-editor.org/rfc/rfc9711>.

12.2.  Informative References

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   [I-D.birkholz-rats-corim]
              Birkholz, H., Fossati, T., Deshpande, Y., Smith, N., and
              W. Pan, "Concise Reference Integrity Manifest", Work in
              Progress, Internet-Draft, draft-birkholz-rats-corim-03, 11
              July 2022, <https://datatracker.ietf.org/doc/html/draft-
              birkholz-rats-corim-03>.

   [I-D.ietf-scitt-architecture]
              Birkholz, H., Delignat-Lavaud, A., Fournet, C., Deshpande,
              Y., and S. Lasker, "An Architecture for Trustworthy and
              Transparent Digital Supply Chains", Work in Progress,
              Internet-Draft, draft-ietf-scitt-architecture-14, 4 July
              2025, <https://datatracker.ietf.org/doc/html/draft-ietf-
              scitt-architecture-14>.

   [I-D.ietf-suit-trust-domains]
              Moran, B. and K. Takayama, "SUIT Manifest Extensions for
              Multiple Trust Domains", Work in Progress, Internet-Draft,
              draft-ietf-suit-trust-domains-10, 3 March 2025,
              <https://datatracker.ietf.org/doc/html/draft-ietf-suit-
              trust-domains-10>.

   [RFC7252]  Shelby, Z., Hartke, K., and C. Bormann, "The Constrained
              Application Protocol (CoAP)", RFC 7252,
              DOI 10.17487/RFC7252, June 2014,
              <https://www.rfc-editor.org/rfc/rfc7252>.

   [RFC9147]  Rescorla, E., Tschofenig, H., and N. Modadugu, "The
              Datagram Transport Layer Security (DTLS) Protocol Version
              1.3", RFC 9147, DOI 10.17487/RFC9147, April 2022,
              <https://www.rfc-editor.org/rfc/rfc9147>.

   [RFC9334]  Birkholz, H., Thaler, D., Richardson, M., Smith, N., and
              W. Pan, "Remote ATtestation procedureS (RATS)
              Architecture", RFC 9334, DOI 10.17487/RFC9334, January
              2023, <https://www.rfc-editor.org/rfc/rfc9334>.

Appendix A.  Full CDDL

   In order to create a valid SUIT_Report document the structure of the
   corresponding CBOR message MUST adhere to the following CDDL data
   definition.

   To be valid, the following CDDL MUST have the COSE CDDL appended to
   it.  The COSE CDDL can be obtained by following the directions in
   [RFC9052], Section 1.4.  It must also have the CDDL from
   [I-D.ietf-suit-mti] appended to it.

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   =============== NOTE: '\' line wrapping per RFC 8792 ================

   SUIT_Report_Tool_Tweak /= SUIT_start
   SUIT_Report_Tool_Tweak /= SUIT_Report_Protected
   SUIT_Report_Protected /= SUIT_COSE_tool_tweak

   SUIT_Report_Protected /= SUIT_Report_COSE_Sign1 .and \
                                                      SUIT_COSE_Profiles
   SUIT_Report_Protected /= SUIT_Report_COSE_Sign1_Tagged .and \
                                                      SUIT_COSE_Profiles
   SUIT_Report_Protected /= SUIT_Report_COSE_MAC0 .and \
                                                      SUIT_COSE_Profiles
   SUIT_Report_Protected /= SUIT_Report_COSE_MAC0_Tagged .and \
                                                      SUIT_COSE_Profiles

   SUIT_Report_COSE_Sign1_Tagged = #6.18(SUIT_Report_COSE_Sign1)
   SUIT_Report_COSE_Sign1 = [
       protected : bstr,
       unprotected : {* int => any},
       payload : bstr .cbor SUIT_Report_Unprotected,
       signature : bstr
   ]
   SUIT_Report_COSE_MAC0_Tagged = #6.17(SUIT_Report_COSE_MAC0)
   SUIT_Report_COSE_MAC0 = [
       protected : bstr,
       unprotected : {* int => any},
       payload : bstr .cbor SUIT_Report_Unprotected,
       tag : bstr
   ]
   SUIT_Report_Unprotected = SUIT_Report / SUIT_Report_COSE_Encrypt0
   SUIT_Report_COSE_Encrypt0 = COSE_Encrypt0

   SUIT_Report = {
     suit-reference              => SUIT_Reference,
     ? suit-report-nonce         => bstr,
     suit-report-records         => [
       * SUIT_Record / system-property-claims ],
     suit-report-result          => true / {
       suit-report-result-code   => int,
       suit-report-result-record => SUIT_Record,
       suit-report-result-reason => SUIT_Report_Reasons,
     },
     ? suit-report-capability-report => SUIT_Capability_Report,
     $$SUIT_Report_Extensions
   }

   SUIT_Reference = [
       suit-report-manifest-uri : tstr,

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       suit-report-manifest-digest : SUIT_Digest
   ]

   SUIT_Record = [
       suit-record-manifest-id        : [* uint ],
       suit-record-manifest-section   : int,
       suit-record-section-offset     : uint,
       suit-record-component-index    : uint,
       suit-record-properties         : {*$$SUIT_Parameters},
       $$SUIT_Record_Extensions
   ]

   system-property-claims = {
     system-component-id => SUIT_Component_Identifier,
     + $$SUIT_Parameters,
   }

   SUIT_Capability_Report = {
     suit-component-capabilities  => [+ SUIT_Component_Capability]
     suit-command-capabilities          => [+ int],
     suit-parameters-capabilities       => [+ int],
     suit-crypt-algo-capabilities       => [+ int],
     ? suit-envelope-capabilities       => [+ int],
     ? suit-manifest-capabilities       => [+ int],
     ? suit-common-capabilities         => [+ int],
     ? suit-text-capabilities           => [+ int],
     ? suit-text-component-capabilities => [+ int],
     ? suit-dependency-capabilities     => [+ int],
     * [+int]                           => [+ int],
     $$SUIT_Capability_Report_Extensions
   }

   SUIT_Component_Capability = [*bstr,?true]

   suit-report-nonce = 2
   suit-report-records = 3
   suit-report-result = 4
   suit-report-result-code = 5
   suit-report-result-record = 6
   suit-report-result-reason = 7
   suit-report-capability-report = 8
   suit-reference = 99

   system-component-id = 0

   suit-record-manifest-id = 0
   suit-record-manifest-section = 1
   suit-record-section-offset = 2

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   suit-record-component-index = 3
   suit-record-dependency-index = 4
   suit-record-properties = 5

   SUIT_Report_Reasons /= suit-report-reason-ok
   SUIT_Report_Reasons /= suit-report-reason-cbor-parse
   SUIT_Report_Reasons /= suit-report-reason-cose-unsupported
   SUIT_Report_Reasons /= suit-report-reason-alg-unsupported
   SUIT_Report_Reasons /= suit-report-reason-unauthorised
   SUIT_Report_Reasons /= suit-report-reason-command-unsupported
   SUIT_Report_Reasons /= suit-report-reason-component-unsupported
   SUIT_Report_Reasons /= suit-report-reason-component-unauthorised
   SUIT_Report_Reasons /= suit-report-reason-parameter-unsupported
   SUIT_Report_Reasons /= suit-report-severing-unsupported
   SUIT_Report_Reasons /= suit-report-reason-condition-failed
   SUIT_Report_Reasons /= suit-report-reason-operation-failed

   suit-report-reason-ok = 0
   suit-report-reason-cbor-parse = 1
   suit-report-reason-cose-unsupported = 2
   suit-report-reason-alg-unsupported = 3
   suit-report-reason-unauthorised = 4
   suit-report-reason-command-unsupported = 5
   suit-report-reason-component-unsupported = 6
   suit-report-reason-component-unauthorised = 7
   suit-report-reason-parameter-unsupported = 8
   suit-report-severing-unsupported = 9
   suit-report-reason-condition-failed = 10
   suit-report-reason-operation-failed = 11

   suit-component-capabilities        = 1
   suit-command-capabilities          = 2
   suit-parameters-capabilities       = 3
   suit-crypt-algo-capabilities       = 4
   suit-envelope-capabilities         = 5
   suit-manifest-capabilities         = 6
   suit-common-capabilities           = 7
   suit-text-capabilities             = 8
   suit-text-component-capabilities   = 9
   suit-dependency-capabilities       = 10

Authors' Addresses

   Brendan Moran
   Arm Limited
   Email: brendan.moran.ietf@gmail.com

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   Henk Birkholz
   Fraunhofer SIT
   Rheinstrasse 75
   64295 Darmstadt
   Germany
   Email: henk.birkholz@ietf.contact

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