SUIT                                                            B. Moran
Internet-Draft                                             H. Tschofenig
Intended status: Standards Track                             Arm Limited
Expires: November 26, 2021 January 13, 2022                                    H. Birkholz
                                                          Fraunhofer SIT
                                                             K. Zandberg
                                                                   Inria
                                                            May 25,
                                                           July 12, 2021

A Concise Binary Object Representation (CBOR)-based Serialization Format
    for the Software Updates for Internet of Things (SUIT) Manifest
                      draft-ietf-suit-manifest-13
                      draft-ietf-suit-manifest-14

Abstract

   This specification describes the format of a manifest.  A manifest is
   a bundle of metadata about code/data obtained by a recipient (chiefly
   the firmware for an IoT device), where to find the that code/data,
   the devices to which it applies, and cryptographic information
   protecting the manifest.  Software updates and Trusted Invocation
   both tend to use sequences of common operations, so the manifest
   encodes those sequences of operations, rather than declaring the
   metadata.

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
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   This Internet-Draft will expire on November 26, 2021. January 13, 2022.

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Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   4
   2.  Conventions and Terminology . . . . . . . . . . . . . . . . .   6
   3.  How to use this Document  . . . . . . . . . . . . . . . . . .   8
   4.  Background  . . . . . . . . . . . . . . . . . . . . . . . . .   9
     4.1.  IoT Firmware Update Constraints . . . . . . . . . . . . .   9
     4.2.  SUIT Workflow Model . . . . . . . . . . . . . . . . . . .  10
   5.  Metadata Structure Overview . . . . . . . . . . . . . . . . .  11
     5.1.  Envelope  . . . . . . . . . . . . . . . . . . . . . . . .  13  12
     5.2.  Delegation Chains . . . . . . . . . . . . . . . . . . . .  13
     5.3.  Authentication Block  . . . . . . . . . . . . . . . . . .  13
     5.4.  Manifest  . . . . . . . . . . . . . . . . . . . . . . . .  14  13
       5.4.1.  Critical Metadata . . . . . . . . . . . . . . . . . .  14
       5.4.2.  Common  . . . . . . . . . . . . . . . . . . . . . . .  14
       5.4.3.  Command Sequences . . . . . . . . . . . . . . . . . .  14
       5.4.4.  Integrity Check Values  . . . . . . . . . . . . . . .  15
       5.4.5.  Human-Readable Text . . . . . . . . . . . . . . . . .  15
     5.5.  Severable Elements  . . . . . . . . . . . . . . . . . . .  15
     5.6.  Integrated Dependencies and Payloads  . . . . . . . . . .  16
   6.  Manifest Processor Behavior . . . . . . . . . . . . . . . . .  16
     6.1.  Manifest Processor Setup  . . . . . . . . . . . . . . . .  16
     6.2.  Required Checks . . . . . . . . . . . . . . . . . . . . .  17
       6.2.1.  Minimizing Signature Verifications  . . . . . . . . .  19
     6.3.  Interpreter Fundamental Properties  . . . . . . . . . . .  20
     6.4.  Abstract Machine Description  . . . . . . . . . . . . . .  20
     6.5.  Special Cases of Component Index and Dependency Index . .  23
     6.6.  Serialized Processing Interpreter . . . . . . . . . . . .  24
     6.7.  Parallel Processing Interpreter . . . . . . . . . . . . .  25
     6.8.  Processing Dependencies . . . . . . . . . . . . . . . . .  25
     6.9.  Multiple Manifest Processors  . . . . . . . . . . . . . .  26
   7.  Creating Manifests  . . . . . . . . . . . . . . . . . . . . .  27
     7.1.  Compatibility Check Template  . . . . . . . . . . . . . .  28
     7.2.  Trusted Invocation Template . . . . . . . . . . . . . . .  28
     7.3.  Component Download Template . . . . . . . . . . . . . . .  28
     7.4.  Install Template  . . . . . . . . . . . . . . . . . . . .  29
     7.5.  Install and Transform Template  . . . . . . . . . . . . .  30
     7.6.  Integrated Payload Template . . . . . . . . . . . . . . .  31
     7.7.  Load from Nonvolatile Storage Template  . . . . . . . . .  31
     7.8.  Load & Decompress from Nonvolatile Storage Template . . .  31
     7.9.  Dependency Template . . . . . . . . . . . . . . . . . . .  32
       7.9.1.  Composite Manifests . . . . . . . . . . . . . . . . .  33
     7.10. Encrypted Manifest Template . . . . . . . . . . . . . . .  33
     7.11. A/B Image Template  . . . . . . . . . . . . . . . . . . .  34
   8.  Metadata Structure  . . . . . . . . . . . . . . . . . . . . .  35
     8.1.  Encoding Considerations . . . . . . . . . . . . . . . . .  35
     8.2.  Envelope  . . . . . . . . . . . . . . . . . . . . . . . .  36
     8.3.  Delegation Chains . . . . . . . . . . . . . . . . . . . .  36
     8.4.  Authenticated Manifests . . . . . . . . . . . . . . . . .  36
     8.5.  Encrypted Manifests . . . . . . . . . . . . . . . . . . .  37
     8.6.  Manifest  . . . . . . . . . . . . . . . . . . . . . . . .  37
       8.6.1.  suit-manifest-version . . . . . . . . . . . . . . . .  38
       8.6.2.  suit-manifest-sequence-number . . . . . . . . . . . .  38
       8.6.3.  suit-reference-uri  . . . . . . . . . . . . . . . . .  38
       8.6.4.  suit-text . . . . . . . . . . . . . . . . . . . . . .  38
     8.7.  text-version-required . . . . . . . . . . . . . . . . . .  40
       8.7.1.  suit-coswid . . . . . . . . . . . . . . . . . . . . .  40  41
       8.7.2.  suit-common . . . . . . . . . . . . . . . . . . . . .  40  41
       8.7.3.  SUIT_Command_Sequence . . . . . . . . . . . . . . . .  42  43
       8.7.4.  Reporting Policy  . . . . . . . . . . . . . . . . . .  44  45
       8.7.5.  SUIT_Parameters . . . . . . . . . . . . . . . . . . .  46
       8.7.6.  SUIT_Condition  . . . . . . . . . . . . . . . . . . .  57
       8.7.7.  SUIT_Directive  . . . . . . . . . . . . . . . . . . .  61
       8.7.8.  suit-directive-garbage-collect  suit-directive-unlink . . . . . . . . . . . . . . . .  68
       8.7.9.  Integrity Check Values  . . . . . . . . . . . . . . .  69
     8.8.  Severable Elements  . . . . . . . . . . . . . . . . . . .  69
   9.  Access Control Lists  . . . . . . . . . . . . . . . . . . . .  70
   10. SUIT Digest Container . . . . . . . . . . . . . . . . . . . .  70
   11. IANA Considerations . . . . . . . . . . . . . . . . . . . . .  70  71
     11.1.  SUIT Commands  . . . . . . . . . . . . . . . . . . . . .  71
     11.2.  SUIT Parameters  . . . . . . . . . . . . . . . . . . . .  73
     11.3.  SUIT Text Values . . . . . . . . . . . . . . . . . . . .  74  75
     11.4.  SUIT Component Text Values . . . . . . . . . . . . . . .  74  75
     11.5.  SUIT Algorithm Identifiers . . . . . . . . . . . . . . .  74  75
       11.5.1.  SUIT Digest Algorithm Identifiers  . . . . . . . . .  74
       11.5.2.  SUIT Compression Algorithm Identifiers . . . . . . .  75
       11.5.3.
       11.5.2.  Unpack Algorithms  . . . . . . . . . . . . . . . . .  75  76
   12. Security Considerations . . . . . . . . . . . . . . . . . . .  76
   13. Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .  76
   14. References  . . . . . . . . . . . . . . . . . . . . . . . . .  76  77
     14.1.  Normative References . . . . . . . . . . . . . . . . . .  76  77
     14.2.  Informative References . . . . . . . . . . . . . . . . .  77  78
   Appendix A.  A. Full CDDL . . . . . . . . . . . . . . . . . . . .  79  80
   Appendix B.  B. Examples  . . . . . . . . . . . . . . . . . . . .  88  89
     B.1.  Example 0: Secure Boot  . . . . . . . . . . . . . . . . .  89  90
     B.2.  Example 1: Simultaneous Download and Installation of
           Payload . . . . . . . . . . . . . . . . . . . . . . . . .  91  92

     B.3.  Example 2: Simultaneous Download, Installation, Secure
           Boot, Severed Fields  . . . . . . . . . . . . . . . . . .  93  94
     B.4.  Example 3: A/B images . . . . . . . . . . . . . . . . . .  96  98
     B.5.  Example 4: Load and Decompress from External Storage  . .  99 101
     B.6.  Example 5: Two Images . . . . . . . . . . . . . . . . . . 102 104
   Appendix C.  C. Design Rational . . . . . . . . . . . . . . . . . 105 107
     C.1.  C.1 Design Rationale: Envelope  . . . . . . . . . . . . . 106 108
     C.2.  C.2 Byte String Wrappers  . . . . . . . . . . . . . . . . 107 109
   Appendix D.  D. Implementation Conformance Matrix . . . . . . . . 107 109
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . . 111 113

1.  Introduction

   A firmware update mechanism is an essential security feature for IoT
   devices to deal with vulnerabilities.  While the transport of
   firmware images to the devices themselves is important there are
   already various techniques available.  Equally important is the
   inclusion of metadata about the conveyed firmware image (in the form
   of a manifest) and the use of a security wrapper to provide end-to-
   end security protection to detect modifications and (optionally) to
   make reverse engineering more difficult.  End-to-end security allows
   the author, who builds the firmware image, to be sure that no other
   party (including potential adversaries) can install firmware updates
   on IoT devices without adequate privileges.  For confidentiality
   protected firmware images it is additionally required to encrypt the
   firmware image.  Starting security protection at the author is a risk
   mitigation technique so firmware images and manifests can be stored
   on untrusted repositories; it also reduces the scope of a compromise
   of any repository or intermediate system to be no worse than a denial
   of service.

   A manifest is a bundle of metadata describing one or more code or
   data payloads and how to:

   -  Obtain any dependencies

   -  Obtain the payload(s)

   -  Install them

   -  Verify them

   -  Load them into memory

   -  Invoke them

   This specification defines the SUIT manifest format and it is
   intended to meet several goals:

   -  Meet the requirements defined in
      [I-D.ietf-suit-information-model].

   -  Simple to parse on a constrained node

   -  Simple to process on a constrained node

   -  Compact encoding

   -  Comprehensible by an intermediate system

   -  Expressive enough to enable advanced use cases on advanced nodes

   -  Extensible

   The SUIT manifest can be used for a variety of purposes throughout
   its lifecycle, such as:

   -  a Firmware Author to reason about releasing a firmware.

   -  a Network Operator to reason about compatibility of a firmware.

   -  a Device Operator to reason about the impact of a firmware.

   -  the Device Operator to manage distribution of firmware to devices.

   -  a Plant Manager to reason about timing and acceptance of firmware
      updates.

   -  a device to reason about the authority & authenticity of a
      firmware prior to installation.

   -  a device to reason about the applicability of a firmware.

   -  a device to reason about the installation of a firmware.

   -  a device to reason about the authenticity & encoding of a firmware
      at boot.

   Each of these uses happens at a different stage of the manifest
   lifecycle, so each has different requirements.

   It is assumed that the reader is familiar with the high-level
   firmware update architecture [I-D.ietf-suit-architecture] and the
   threats, requirements, and user stories in
   [I-D.ietf-suit-information-model].

   The design of this specification is based on an observation that the
   vast majority of operations that a device can perform during an
   update or Trusted Invocation are composed of a small group of
   operations:

   -  Copy some data from one place to another

   -  Transform some data

   -  Digest some data and compare to an expected value

   -  Compare some system parameters to an expected value

   -  Run some code

   In this document, these operations are called commands.  Commands are
   classed as either conditions or directives.  Conditions have no side-
   effects, while directives do have side-effects.  Conceptually, a
   sequence of commands is like a script but the used language is
   tailored to software updates and Trusted Invocation.

   The available commands support simple steps, such as copying a
   firmware image from one place to another, checking that a firmware
   image is correct, verifying that the specified firmware is the
   correct firmware for the device, or unpacking a firmware.  By using
   these steps in different orders and changing the parameters they use,
   a broad range of use cases can be supported.  The SUIT manifest uses
   this observation to optimize metadata for consumption by constrained
   devices.

   While the SUIT manifest is informed by and optimized for firmware
   update and Trusted Invocation use cases, there is nothing in the
   [I-D.ietf-suit-information-model] that restricts its use to only
   those use cases.  Other use cases include the management of trusted
   applications (TAs) in a Trusted Execution Environment (TEE), as
   discussed in [I-D.ietf-teep-architecture].

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.

   Additionally, the following terminology is used throughout this
   document:

   -  SUIT: Software Update for the Internet of Things, also the IETF
      working group for this standard.

   -  Payload: A piece of information to be delivered.  Typically
      Firmware for the purposes of SUIT.

   -  Resource: A piece of information that is used to construct a
      payload.

   -  Manifest: A manifest is a bundle of metadata about the firmware
      for an IoT device, where to find the firmware, and the devices to
      which it applies.

   -  Envelope: A container with the manifest, an authentication wrapper
      with cryptographic information protecting the manifest,
      authorization information, and severable elements (see: TBD).

   -  Update: One or more manifests that describe one or more payloads.

   -  Update Authority: The owner of a cryptographic key used to sign
      updates, trusted by Recipients.

   -  Recipient: The system, typically an IoT device, that receives and
      processes a manifest.

   -  Manifest Processor: A component of the Recipient that consumes
      Manifests and executes the commands in the Manifest.

   -  Component: An updatable logical block of the Firmware, Software,
      configuration, or data of the Recipient.

   -  Component Set: A group of interdependent Components that must be
      updated simultaneously.

   -  Command: A Condition or a Directive.

   -  Condition: A test for a property of the Recipient or its
      Components.

   -  Directive: An action for the Recipient to perform.

   -  Trusted Invocation: A process by which a system ensures that only
      trusted code is executed, for example secure boot or launching a
      Trusted Application.

   -  A/B images: Dividing a Recipient's storage into two or more
      bootable images, at different offsets, such that the active image
      can write to the inactive image(s).

   -  Record: The result of a Command and any metadata about it.

   -  Report: A list of Records.

   -  Procedure: The process of invoking one or more sequences of
      commands.

   -  Update Procedure: A procedure that updates a Recipient by fetching
      dependencies and images, and installing them.

   -  Invocation Procedure: A procedure in which a Recipient verifies
      dependencies and images, loading images, and invokes one or more
      image.

   -  Software: Instructions and data that allow a Recipient to perform
      a useful function.

   -  Firmware: Software that is typically changed infrequently, stored
      in nonvolatile memory, and small enough to apply to [RFC7228]
      Class 0-2 devices.

   -  Image: Information that a Recipient uses to perform its function,
      typically firmware/software, configuration, or resource data such
      as text or images.  Also, a Payload, once installed is an Image.

   -  Slot: One of several possible storage locations for a given
      Component, typically used in A/B image systems

   -  Abort: An event in which the Manifest Processor immediately halts
      execution of the current Procedure.  It creates a Record of an
      error condition.

3.  How to use this Document

   This specification covers five aspects of firmware update:

   -  Section 4 describes the device constraints, use cases, and design
      principles that informed the structure of the manifest.

   -  Section 5 gives a general overview of the metadata structure to
      inform the following sections

   -  Section 6 describes what actions a Manifest processor should take.

   -  Section 7 describes the process of creating a Manifest.

   -  Section 8 specifies the content of the Envelope and the Manifest.

   To implement an updatable device, see Section 6 and Section 8.  To
   implement a tool that generates updates, see Section 7 and Section 8.

   The IANA consideration section, see Section 11, provides instructions
   to IANA to create several registries.  This section also provides the
   CBOR labels for the structures defined in this document.

   The complete CDDL description is provided in Appendix A, examples are
   given in Appendix B and a design rational is offered in Appendix C.
   Finally, Appendix D gives a summarize of the mandatory-to-implement
   features of this specification.

4.  Background

   Distributing software updates to diverse devices with diverse trust
   anchors in a coordinated system presents unique challenges.  Devices
   have a broad set of constraints, requiring different metadata to make
   appropriate decisions.  There may be many actors in production IoT
   systems, each of whom has some authority.  Distributing firmware in
   such a multi-party environment presents additional challenges.  Each
   party requires a different subset of data.  Some data may not be
   accessible to all parties.  Multiple signatures may be required from
   parties with different authorities.  This topic is covered in more
   depth in [I-D.ietf-suit-architecture].  The security aspects are
   described in [I-D.ietf-suit-information-model].

4.1.  IoT Firmware Update Constraints

   The various constraints of IoT devices and the range of use cases
   that need to be supported create a broad set of requirements.  For
   example, devices with:

   -  limited processing power and storage may require a simple
      representation of metadata.

   -  bandwidth constraints may require firmware compression or partial
      update support.

   -  bootloader complexity constraints may require simple selection
      between two bootable images.

   -  small internal storage may require external storage support.

   -  multiple microcontrollers may require coordinated update of all
      applications.

   -  large storage and complex functionality may require parallel
      update of many software components.

   -  extra information may need to be conveyed in the manifest in the
      earlier stages of the device lifecycle before those data items are
      stripped when the manifest is delivered to a constrained device.

   Supporting the requirements introduced by the constraints on IoT
   devices requires the flexibility to represent a diverse set of
   possible metadata, but also requires that the encoding is kept
   simple.

4.2.  SUIT Workflow Model

   There are several fundamental assumptions that inform the model of
   Update Procedure workflow:

   -  Compatibility must be checked before any other operation is
      performed.

   -  All dependency manifests should be present before any payload is
      fetched.

   -  In some applications, payloads must be fetched and validated prior
      to installation.

   There are several fundamental assumptions that inform the model of
   the Invocation Procedure workflow:

   -  Compatibility must be checked before any other operation is
      performed.

   -  All dependencies and payloads must be validated prior to loading.

   -  All loaded images must be validated prior to execution.

   Based on these assumptions, the manifest is structured to work with a
   pull parser, where each section of the manifest is used in sequence.
   The expected workflow for a Recipient installing an update can be
   broken down into five steps:

   1.  Verify the signature of the manifest.

   2.  Verify the applicability of the manifest.

   3.  Resolve dependencies.

   4.  Fetch payload(s).

   5.  Install payload(s).

   When installation is complete, similar information can be used for
   validating and running images in a further three steps:

   1.  Verify image(s).

   2.  Load image(s).

   3.  Run image(s).

   If verification and running is implemented in a bootloader, then the
   bootloader MUST also verify the signature of the manifest and the
   applicability of the manifest in order to implement secure boot
   workflows.  The bootloader may add its own authentication, e.g. a
   Message Authentication Code (MAC), to the manifest in order to
   prevent further verifications.

   When multiple manifests are used for an update, each manifest's steps
   occur in a lockstep fashion; all manifests have dependency resolution
   performed before any manifest performs a payload fetch, etc.

5.  Metadata Structure Overview

   This section provides a high level overview of the manifest
   structure.  The full description of the manifest structure is in
   Section 8.6

   The manifest is structured from several key components:

   1.  The Envelope (see Section 5.1) contains Delegation Chains, the
       Authentication Block, the Manifest, any Severable Elements, and
       any Integrated Payloads or Dependencies.

   2.  Delegation Chains (see Section 5.2) allow a Recipient to work
       from one of its Trust Anchors to an authority of the
       Authentication Block.

   3.  The Authentication Block (see Section 5.3) contains a list of
       signatures or MACs of the manifest..

   4.  The Manifest (see Section 5.4) contains all critical, non-
       severable metadata that the Recipient requires.  It is further
       broken down into:

       1.  Critical metadata, such as sequence number.

       2.  Common metadata, including lists of dependencies and affected
           components.

       3.  Command sequences, directing the Recipient how to install and
           use the payload(s).

       4.  Integrity check values for severable elements.

   5.  Severable elements (see Section 5.5).

   6.  Integrated dependencies (see Section 5.6).

   7.  Integrated payloads (see Section 5.6).

   The diagram below illustrates the hierarchy of the Envelope.

   +-------------------------+
   | Envelope                |
   +-------------------------+
   | Delegation Chains       |
   | Authentication Block    |
   | Manifest           --------------> +------------------------------+
   | Severable Elements      |          | Manifest                     |
   | Human-Readable Text     |          +------------------------------+
   | COSWID                  |          | Structure Version            |
   | Integrated Dependencies |          | Sequence Number              |
   | Integrated Payloads     |          | Reference to Full Manifest   |
   +-------------------------+    +------ Common Structure             |
                                  | +---- Command Sequences            |
   +-------------------------+    | |   | Digests of Envelope Elements |
   | Common Structure        | <--+ |   +------------------------------+
   +-------------------------+      |
   | Dependencies            |      +-> +-----------------------+
   | Components IDs          |          | Command Sequence      |
   | Common Command Sequence ---------> +-----------------------+
   +-------------------------+          | List of ( pairs of (  |
                                        |   * command code      |
                                        |   * argument /        |
                                        |      reporting policy |
                                        | ))                    |
                                        +-----------------------+

5.1.  Envelope

   The SUIT Envelope is a container that encloses Delegation Chains, the
   Authentication Block, the Manifest, any Severable Elements, and any
   integrated payloads or dependencies.  The Envelope is used instead of
   conventional cryptographic envelopes, such as COSE_Envelope because
   it allows modular processing, severing of elements, and integrated
   payloads in a way that would add substantial complexity with existing
   solutions.  See Appendix C.1 for a description of the reasoning for
   this.

   See Section 8.2 for more detail.

5.2.  Delegation Chains

   Delegation Chains allow a Recipient to establish a chain of trust
   from a Trust Anchor to the signer of a manifest by validating
   delegation claims.  Each delegation claim is a [RFC8392] CBOR Web
   Tokens (CWTs).  The first claim in each list is signed by a Trust
   Anchor.  Each subsequent claim in a list is signed by the public key
   claimed in the preceding list element.  The last element in each list
   claims a public key that can be used to verify a signature in the
   Authentication Block (Section 5.3).

   See Section 8.3 for more detail.

5.3.  Authentication Block

   The Authentication Block contains a bstr-wrapped SUIT Digest
   Container, see Section 10 10, and one or more [RFC8152] CBOR Object
   Signing and Encryption (COSE) authentication blocks.  These blocks
   are one of:

   -  COSE_Sign_Tagged

   -  COSE_Sign1_Tagged

   -  COSE_Mac_Tagged

   -  COSE_Mac0_Tagged

   Each of these objects is used in detached payload mode.  The payload
   is the bstr-wrapped SUIT_Digest.

   See Section 8.4 for more detail.

5.4.  Manifest

   The Manifest contains most metadata about one or more images.  The
   Manifest is divided into Critical Metadata, Common Metadata, Command
   Sequences, and Integrity Check Values.

   See Section 8.6 for more detail.

5.4.1.  Critical Metadata

   Some metadata needs to be accessed before the manifest is processed.
   This metadata can be used to determine which manifest is newest and
   whether the structure version is supported.  It also MAY provide a
   URI for obtaining a canonical copy of the manifest and Envelope.

   See Section 8.6.1, Section 8.6.2, and Section 8.6.3 for more detail.

5.4.2.  Common

   Some metadata is used repeatedly and in more than one command
   sequence.  In order to reduce the size of the manifest, this metadata
   is collected into the Common section.  Common is composed of three
   parts: a list of dependencies, a list of components referenced by the
   manifest, and a command sequence to execute prior to each other
   command sequence.  The common command sequence is typically used to
   set commonly used values and perform compatibility checks.  The
   common command sequence MUST NOT have any side-effects outside of
   setting parameter values.

   See Section 8.7.2, and Section 8.7.2.1 for more detail.

5.4.3.  Command Sequences

   Command sequences provide the instructions that a Recipient requires
   in order to install or use an image.  These sequences tell a device
   to set parameter values, test system parameters, copy data from one
   place to another, transform data, digest data, and run code.

   Command sequences are broken up into three groups: Common Command
   Sequence (see Section 5.4.2), update commands, and secure boot
   commands.

   Update Command Sequences are: Dependency Resolution, Payload Fetch,
   and Payload Installation.  An Update Procedure is the complete set of
   each Update Command Sequence, each preceded by the Common Command
   Sequence.

   Invocation Command Sequences are: System Validation, Image Loading,
   and Image Invocation.  A Invocation Procedure is the complete set of
   each Invocation Command Sequence, each preceded by the Common Command
   Sequence.

   Command Sequences are grouped into these sets to ensure that there is
   common coordination between dependencies and dependents on when to
   execute each command.

   See Section 8.7.3 for more detail.

5.4.4.  Integrity Check Values

   To enable Section 5.5, there needs to be a mechanism to verify
   integrity of any metadata outside the manifest.  Integrity Check
   Values are used to verify the integrity of metadata that is not
   contained in the manifest.  This MAY include Severable Command
   Sequences, Concise Software Identifiers (CoSWID
   [I-D.ietf-sacm-coswid]), or Text data.  Integrated Dependencies and
   Integrated Payloads are integrity-checked using Command Sequences, so
   they do not have Integrity Check Values present in the Manifest.

   See Section 8.7.9 for more detail.

5.4.5.  Human-Readable Text

   Text is typically a Severable Element (Section 5.5).  It contains all
   the text that describes the update.  Because text is explicitly for
   human consumption, it is all grouped together so that it can be
   Severed easily.  The text section has space both for describing the
   manifest as a whole and for describing each individual component.

   See Section 8.6.4 for more detail.

5.5.  Severable Elements

   Severable Elements are elements of the Envelope (Section 5.1) that
   have Integrity Check Values (Section 5.4.4) in the Manifest
   (Section 5.4).

   Because of this organisation, these elements can be discarded or
   "Severed" from the Envelope without changing the signature of the
   Manifest.  This allows savings based on the size of the Envelope in
   several scenarios, for example:

   -  A management system severs the Text and CoSWID sections before
      sending an Envelope to a constrained Recipient, which saves
      Recipient bandwidth.

   -  A Recipient severs the Installation section after installing the
      Update, which saves storage space.

   See Section 8.8 for more detail.

5.6.  Integrated Dependencies and Payloads

   In some cases, it is beneficial to include a dependency or a payload
   in the Envelope of a manifest.  For example:

   -  When an update is delivered via a comparatively unconstrained
      medium, such as a removable mass storage device, it may be
      beneficial to bundle updates into single files.

   -  When a manifest requires encryption, it must be referenced as a
      dependency, so a trivial manifest may be used to enclose the
      encrypted manifest.  The encrypted manifest may be contained in
      the dependent manifest's envelope.

   -  When a manifest transports a small payload, such as an encrypted
      key, that payload may be placed in the manifest's envelope.

   See Section 7.9.1, Section 8.5 for more detail.

6.  Manifest Processor Behavior

   This section describes the behavior of the manifest processor and
   focuses primarily on interpreting commands in the manifest.  However,
   there are several other important behaviors of the manifest
   processor: encoding version detection, rollback protection, and
   authenticity verification are chief among these.

6.1.  Manifest Processor Setup

   Prior to executing any command sequence, the manifest processor or
   its host application MUST inspect the manifest version field and fail
   when it encounters an unsupported encoding version.  Next, the
   manifest processor or its host application MUST extract the manifest
   sequence number and perform a rollback check using this sequence
   number.  The exact logic of rollback protection may vary by
   application, but it has the following properties:

   -  Whenever the manifest processor can choose between several
      manifests, it MUST select the latest valid, authentic manifest.

   -  If the latest valid, authentic manifest fails, it MAY select the
      next latest valid, authentic manifest, according to application-
      specific policy.

   Here, valid means that a manifest has a supported encoding version
   and it has not been excluded for other reasons.  Reasons for
   excluding typically involve first executing the manifest and may
   include:

   -  Test failed (e.g.  Vendor ID/Class ID).

   -  Unsupported command encountered.

   -  Unsupported parameter encountered.

   -  Unsupported Component Identifier encountered.

   -  Payload not available.

   -  Dependency not available.

   -  Application crashed when executed.

   -  Watchdog timeout occurred.

   -  Dependency or Payload verification failed.

   -  Missing component from a set.

   -  Required parameter not supplied.

   These failure reasons MAY be combined with retry mechanisms prior to
   marking a manifest as invalid.

   Selecting an older manifest in the event of failure of the latest
   valid manifest is a robustness mechanism that is necessary for
   supporting the requirements in [I-D.ietf-suit-architecture], section
   3.5.  It may not be appropriate for all applications.  In particular
   Trusted Execution Environments MAY require a failure to invoke a new
   installation, rather than a rollback approach.  See
   [I-D.ietf-suit-information-model], Section 4.2.1 for more discussion
   on the security considerations that apply to rollback.

   Following these initial tests, the manifest processor clears all
   parameter storage.  This ensures that the manifest processor begins
   without any leaked data.

6.2.  Required Checks

   The RECOMMENDED process is to verify the signature of the manifest
   prior to parsing/executing any section of the manifest.  This guards
   the parser against arbitrary input by unauthenticated third parties,
   but it costs extra energy when a Recipient receives an incompatible
   manifest.

   When validating authenticity of manifests, the manifest processor MAY
   use an ACL (see Section 9) to determine the extent of the rights
   conferred by that authenticity.  Where a device supports only one
   level of access, it MAY choose to skip signature verification of
   dependencies, since they are referenced by digest.  Where a device
   supports more than one trusted party, it MAY choose to defer the
   verification of signatures of dependencies until the list of affected
   components is known so that it can skip redundant signature
   verifications.  For example, a dependency signed by the same author
   as the dependent does not require a signature verification.
   Similarly, if the signer of the dependent has full rights to the
   device, according to the ACL, then no signature verification is
   necessary on the dependency.

   Once a valid, authentic manifest has been selected, the manifest
   processor MUST examine the component list and verify that its maximum
   number of components is not exceeded and that each listed component
   is supported.

   For each listed component, the manifest processor MUST provide
   storage for the supported parameters.  If the manifest processor does
   not have sufficient temporary storage to process the parameters for
   all components, it MAY process components serially for each command
   sequence.  See Section 6.6 for more details.

   The manifest processor SHOULD check that the common sequence contains
   at least Check Vendor Identifier command and at least one Check Class
   Identifier command.

   Because the common sequence contains Check Vendor Identifier and
   Check Class Identifier command(s), no custom commands are permitted
   in the common sequence.  This ensures that any custom commands are
   only executed by devices that understand them.

   If the manifest contains more than one component and/or dependency,
   each command sequence MUST begin with a Set Component Index or Set
   Dependency Index command.

   If a dependency is specified, then the manifest processor MUST
   perform the following checks:

   1.  At the beginning of each section in the dependent: all previous
       sections of each dependency have been executed.

   2.  At the end of each section in the dependent: The corresponding
       section in each dependency has been executed.

   If the interpreter does not support dependencies and a manifest
   specifies a dependency, then the interpreter MUST reject the
   manifest.

   If a Recipient supports groups of interdependent components (a
   Component Set), then it SHOULD verify that all Components in the
   Component Set are specified by one update, that is: a single manifest
   and all its dependencies that together:

   1.  have sufficient permissions imparted by their signatures

   2.  specify a digest and a payload for every Component in the
       Component Set.

   The single dependent manifest is sometimes called a Root Manifest.

6.2.1.  Minimizing Signature Verifications

   Signature verification can be energy and time expensive on a
   constrained device.  MAC verification is typically unaffected by
   these concerns.  A Recipient MAY choose to parse and execute only the
   SUIT_Common section of the manifest prior to signature verification,
   if all of the below apply:

   -  The Authentication Block contains a COSE_Sign_Tagged or
      COSE_Sign1_Tagged

   -  The Recipient receives manifests over an unauthenticated channel,
      exposing it to more inauthentic or incompatible manifests, and

   -  The Recipient has a power budget that makes signature verification
      undesirable

   The guidelines in Creating Manifests (Section 7) require that the
   common section contains the applicability checks, so this section is
   sufficient for applicability verification.  The parser MUST restrict
   acceptable commands to conditions and the following directives:
   Override Parameters, Set Parameters, Try Each, and Run Sequence ONLY.
   The manifest parser MUST NOT execute any command with side-effects
   outside the parser (for example, Run, Copy, Swap, or Fetch commands)
   prior to authentication and any such command MUST Abort.  The Common
   Sequence MUST be executed again in its entirety after authenticity
   validation.

   When executing Common prior to authenticity validation, the Manifest
   Processor MUST evaluate the integrity of the manifest using the
   SUIT_Digest present in the authentication block.

   Alternatively, a Recipient MAY rely on network infrastructure to
   filter inapplicable manifests.

6.3.  Interpreter Fundamental Properties

   The interpreter has a small set of design goals:

   1.  Executing an update MUST either result in an error, or a
       verifiably correct system state.

   2.  Executing a Trusted Invocation MUST either result in an error, or
       an invoked image.

   3.  Executing the same manifest on multiple Recipients MUST result in
       the same system state.

   NOTE: when using A/B images, the manifest functions as two (or more)
   logical manifests, each of which applies to a system in a particular
   starting state.  With that provision, design goal 3 holds.

6.4.  Abstract Machine Description

   The heart of the manifest is the list of commands, which are
   processed by a Manifest Processor-a form of interpreter.  This
   Manifest Processor can be modeled as a simple abstract machine.  This
   machine consists of several data storage locations that are modified
   by commands.

   There are two types of commands, namely those that modify state
   (directives) and those that perform tests (conditions).  Parameters
   are used as the inputs to commands.  Some directives offer control
   flow operations.  Directives target a specific component or
   dependency.  A dependency is another SUIT_Envelope that describes
   additional components.  Dependencies are identified by digest, but
   referenced in commands by Dependency Index, the index into the array
   of Dependencies.  A component is a unit of code or data that can be
   targeted by an update.  Components are identified by Component
   Identifiers, but referenced in commands by Component Index; Component
   Identifiers are arrays of binary strings and a Component Index is an
   index into the array of Component Identifiers.

   Conditions MUST NOT have any side-effects other than informing the
   interpreter of success or failure.  The Interpreter does not Abort if
   the Soft Failure flag (Section 8.7.5.23) is set when a Condition
   reports failure.

   Directives MAY have side-effects in the parameter table, the
   interpreter state, or the current component.  The Interpreter MUST
   Abort if a Directive reports failure regardless of the Soft Failure
   flag.

   To simplify the logic describing the command semantics, the object
   "current" is used.  It represents the component identified by the
   Component Index or the dependency identified by the Dependency Index:

   current := components\[component-index\]
       if component-index is not false
       else dependencies\[dependency-index\]

   As a result, Set Component Index is described as current :=
   components[arg].  The actual operation performed for Set Component
   Index is described by the following pseudocode, however, because of
   the definition of current (above), these are semantically equivalent.

   component-index := arg
   dependency-index := false

   Similarly, Set Dependency Index is semantically equivalent to current
   := dependencies[arg]

   The following table describes the behavior of each command. "params"
   represents the parameters for the current component or dependency.
   Most commands operate on either a component or a dependency.  Setting
   the Component Index clears the Dependency Index.  Setting the
   Dependency Index clears the Component Index.

   +-------------------+-----------------------------------------------+
   | Command Name      | Semantic of the Operation                     |
   +-------------------+-----------------------------------------------+
   | Check Vendor      | assert(binary-match(current,                  |
   | Identifier        | current.params[vendor-id]))                   |
   |                   |                                               |
   | Check Class       | assert(binary-match(current,                  |
   | Identifier        | current.params[class-id]))                    |
   |                   |                                               |
   | Verify Image      | assert(binary-match(digest(current),          |
   |                   | current.params[digest]))                      |
   |                   |                                               |
   | Set Component     | current := components[arg]                    |
   | Index             |                                               |
   |                   |                                               |
   | Override          | current.params[k] := v for-each k,v in arg    |
   | Parameters        |                                               |
   |                   |                                               |
   | Set Dependency    | current := dependencies[arg]                  |
   | Index             |                                               |
   |                   |                                               |
   | Set Parameters    | current.params[k] := v if not k in params     |
   |                   | for-each k,v in arg                           |
   |                   |                                               |
   | Process           | exec(current[common]); exec(current[current-  |
   | Dependency        | segment])                                     |
   |                   |                                               |
   | Run               | run(current)                                  |
   |                   |                                               |
   | Fetch             | store(current, fetch(current.params[uri]))    |
   |                   |                                               |
   | Use Before        | assert(now() < arg)                           |
   |                   |                                               |
   | Check Component   | assert(offsetof(current) assert(current.slot-index == arg)             |
   | Offset Slot              |                                               |
   |                   |                                               |
   | Check Device      | assert(binary-match(current,                  |
   | Identifier        | current.params[device-id]))                   |
   |                   |                                               |
   | Check Image Not   | assert(not binary-match(digest(current),      |
   | Match             | current.params[digest]))                      |
   |                   |                                               |
   | Check Minimum     | assert(battery >= arg)                        |
   | Battery           |                                               |
   |                   |                                               |
   | Check Update      | assert(isAuthorized())                        |
   | Authorized        |                                               |
   |                   |                                               |
   | Check Version     | assert(version_check(current, arg))           |
   |                   |                                               |
   | Abort             | assert(0)                                     |
   |                   |                                               |
   | Try Each          | try-each-done if exec(seq) is not error for-  |
   |                   | each seq in arg                               |
   |                   |                                               |
   | Copy              | store(current, current.params[src-component]) |
   |                   |                                               |
   | Swap              | swap(current, current.params[src-component])  |
   |                   |                                               |
   | Wait For Event    | until event(arg), wait                        |
   |                   |                                               |
   | Run Sequence      | exec(arg)                                     |
   |                   |                                               |
   | Run with          | run(current, arg)                             |
   | Arguments         |                                               |
   |                   |                                               |
   | Garbage Collect Unlink            | garbage-collect(current) unlink(current)                               |
   +-------------------+-----------------------------------------------+

6.5.  Special Cases of Component Index and Dependency Index

   Component Index and Dependency Index can each take on one of three
   types:

   1.  Integer

   2.  Array of integers

   3.  True

   Integers MUST always be supported by Set Component Index and Set
   Dependency Index.  Arrays of integers MUST be supported by Set
   Component Index and Set Dependency Index if the Recipient supports 3
   or more components or 3 or more dependencies, respectively.  True
   MUST be supported by Set Component Index and Set Dependency Index if
   the Recipient supports 2 or more components or 2 or more
   dependencies, respectively.  Each of these operates on the list of
   components or list of dependencies declared in the manifest.

   Integer indices are the default case as described in the previous
   section.  An array of integers represents a list of the components
   (Set Component Index) or a list of dependencies (Set Dependency
   Index) to which each subsequent command applies.  The value True
   replaces the list of component indices or dependency indices with the
   full list of components or the full list of dependencies,
   respectively, as defined in the manifest.

   When a command is executed, it either 1. operates on the component or
   dependency identified by the component index or dependency index if
   that index is an integer, or 2. it operates on each component or
   dependency identified by an array of indicies, or 3. it operates on
   every component or every dependency if the index is the boolean True.
   This is described by the following pseudocode:

   if component-index is true:
       current-list = components
   else if component-index is array:
       current-list = [ components[idx] for idx in component-index ]
   else if component-index is integer:
       current-list = [ components[component-index] ]
   else if dependency-index is true:
       current-list = dependencies
   else if dependency-index is array:
       current-list = [ dependencies[idx] for idx in dependency-index ]
   else:
       current-list = [ dependencies[dependency-index] ]
   for current in current-list:
       cmd(current)

   Try Each and Run Sequence are affected in the same way as other
   commands: they are invoked once for each possible Component or
   Dependency.  This means that the sequences that are arguments to Try
   Each and Run Sequence are NOT invoked with Component Index = True or
   Dependency Index = True, nor are they invoked with array indices.
   They are only invoked with integer indices.  The interpreter loops
   over the whole sequence, setting the Component Index or Dependency
   Index to each index in turn.

6.6.  Serialized Processing Interpreter

   In highly constrained devices, where storage for parameters is
   limited, the manifest processor MAY handle one component at a time,
   traversing the manifest tree once for each listed component.  In this
   mode, the interpreter ignores any commands executed while the
   component index is not the current component.  This reduces the
   overall volatile storage required to process the update so that the
   only limit on number of components is the size of the manifest.
   However, this approach requires additional processing power.

   In order to operate in this mode, the manifest processor loops on
   each section for every supported component, simply ignoring commands
   when the current component is not selected.

   When a serialized Manifest Processor encounters a component or
   dependency index of True, it does not ignore any commands.  It
   applies them to the current component or dependency on each
   iteration.

6.7.  Parallel Processing Interpreter

   Advanced Recipients MAY make use of the Strict Order parameter and
   enable parallel processing of some Command Sequences, or it may
   reorder some Command Sequences.  To perform parallel processing, once
   the Strict Order parameter is set to False, the Recipient may issue
   each or every command concurrently until the Strict Order parameter
   is returned to True or the Command Sequence ends.  Then, it waits for
   all issued commands to complete before continuing processing of
   commands.  To perform out-of-order processing, a similar approach is
   used, except the Recipient consumes all commands after the Strict
   Order parameter is set to False, then it sorts these commands into
   its preferred order, invokes them all, then continues processing.

   Under each of these scenarios the parallel processing MUST halt until
   all issued commands have completed:

   -  Set Parameters.

   -  Override Parameters.

   -  Set Strict Order = True.

   -  Set Dependency Index.

   -  Set Component Index.

   To perform more useful parallel operations, a manifest author may
   collect sequences of commands in a Run Sequence command.  Then, each
   of these sequences MAY be run in parallel.  Each sequence defaults to
   Strict Order = True.  To isolate each sequence from each other
   sequence, each sequence MUST begin with a Set Component Index or Set
   Dependency Index directive with the following exception: when the
   index is either True or an array of indices, the Set Component Index
   or Set Dependency Index is implied.  Any further Set Component Index
   directives MUST cause an Abort.  This allows the interpreter that
   issues Run Sequence commands to check that the first element is
   correct, then issue the sequence to a parallel execution context to
   handle the remainder of the sequence.

6.8.  Processing Dependencies

   As described in Section 6.2, each manifest must invoke each of its
   dependencies sections from the corresponding section of the
   dependent.  Any changes made to parameters by the dependency persist
   in the dependent.

   When a Process Dependency command is encountered, the interpreter
   loads the dependency identified by the Current Dependency Index.  The
   interpreter first executes the common-sequence section of the
   identified dependency, then it executes the section of the dependency
   that corresponds to the currently executing section of the dependent.

   If the specified dependency does not contain the current section,
   Process Dependency succeeds immediately.

   The Manifest Processor MUST also support a Dependency Index of True,
   which applies to every dependency, as described in Section 6.5

   The interpreter also performs the checks described in Section 6.2 to
   ensure that the dependent is processing the dependency correctly.

6.9.  Multiple Manifest Processors

   When a system has multiple security domains, each domain might
   require independent verification of authenticity or security
   policies.  Security domains might be divided by separation technology
   such as Arm TrustZone, Intel SGX, or another TEE technology.
   Security domains might also be divided into separate processors and
   memory spaces, with a communication interface between them.

   For example, an application processor may have an attached
   communications module that contains a processor.  The communications
   module might require metadata signed by a specific Trust Authority
   for regulatory approval.  This may be a different Trust Authority
   than the application processor.

   When there are two or more security domains (see
   [I-D.ietf-teep-architecture]), a manifest processor might be required
   in each.  The first manifest processor is the normal manifest
   processor as described for the Recipient in Section 6.4.  The second
   manifest processor only executes sections when the first manifest
   processor requests it.  An API interface is provided from the second
   manifest processor to the first.  This allows the first manifest
   processor to request a limited set of operations from the second.
   These operations are limited to: setting parameters, inserting an
   Envelope, invoking a Manifest Command Sequence.  The second manifest
   processor declares a prefix to the first, which tells the first
   manifest processor when it should delegate to the second.  These
   rules are enforced by underlying separation of privilege
   infrastructure, such as TEEs, or physical separation.

   When the first manifest processor encounters a dependency prefix,
   that informs the first manifest processor that it should provide the
   second manifest processor with the corresponding dependency Envelope.

   This is done when the dependency is fetched.  The second manifest
   processor immediately verifies any authentication information in the
   dependency Envelope.  When a parameter is set for any component that
   matches the prefix, this parameter setting is passed to the second
   manifest processor via an API.  As the first manifest processor works
   through the Procedure (set of command sequences) it is executing,
   each time it sees a Process Dependency command that is associated
   with the prefix declared by the second manifest processor, it uses
   the API to ask the second manifest processor to invoke that
   dependency section instead.

   This mechanism ensures that the two or more manifest processors do
   not need to trust each other, except in a very limited case.  When
   parameter setting across security domains is used, it must be very
   carefully considered.  Only parameters that do not have an effect on
   security properties should be allowed.  The dependency manifest MAY
   control which parameters are allowed to be set by using the Override
   Parameters directive.  The second manifest processor MAY also control
   which parameters may be set by the first manifest processor by means
   of an ACL that lists the allowed parameters.  For example, a URI may
   be set by a dependent without a substantial impact on the security
   properties of the manifest.

7.  Creating Manifests

   Manifests are created using tools for constructing COSE structures,
   calculating cryptographic values and compiling desired system state
   into a sequence of operations required to achieve that state.  The
   process of constructing COSE structures and the calculation of
   cryptographic values is covered in [RFC8152].

   Compiling desired system state into a sequence of operations can be
   accomplished in many ways.  Several templates are provided below to
   cover common use-cases.  These templates can be combined to produce
   more complex behavior.

   The author MUST ensure that all parameters consumed by a command are
   set prior to invoking that command.  Where Component Index = True or
   Dependency Index = True, this means that the parameters consumed by
   each command MUST have been set for each Component or Dependency,
   respectively.

   This section details a set of templates for creating manifests.
   These templates explain which parameters, commands, and orders of
   commands are necessary to achieve a stated goal.

   NOTE: On systems that support only a single component and no
   dependencies, Set Component Index has no effect and can be omitted.

   NOTE: *A digest MUST always be set using Override Parameters, since
   this prevents a less-privileged dependent from replacing the digest.*

7.1.  Compatibility Check Template

   The goal of the compatibility check template ensure that Recipients
   only install compatible images.

   In this template all information is contained in the common sequence
   and the following sequence of commands is used:

   -  Set Component Index directive (see Section 8.7.7.1)

   -  Set Parameters directive (see Section 8.7.7.5) for Vendor ID and
      Class ID (see Section 8.7.5)

   -  Check Vendor Identifier condition (see Section 8.7.5.2)

   -  Check Class Identifier condition (see Section 8.7.5.2)

7.2.  Trusted Invocation Template

   The goal of the Trusted Invocation template is to ensure that only
   authorized code is invoked; such as in Secure Boot or when a Trusted
   Application is loaded into a TEE.

   The following commands are placed into the common sequence:

   -  Set Component Index directive (see Section 8.7.7.1)

   -  Override Parameters directive (see Section 8.7.7.6) for Image
      Digest and Image Size (see Section 8.7.5)

   Then, the run sequence contains the following commands:

   -  Set Component Index directive (see Section 8.7.7.1)

   -  Check Image Match condition (see Section 8.7.6.2)

   -  Run directive (see Section 8.7.7.12)

7.3.  Component Download Template

   The goal of the Component Download template is to acquire and store
   an image.

   The following commands are placed into the common sequence:

   -  Set Component Index directive (see Section 8.7.7.1)

   -  Override Parameters directive (see Section 8.7.7.6) for Image
      Digest and Image Size (see Section 8.7.5)

   Then, the install sequence contains the following commands:

   -  Set Component Index directive (see Section 8.7.7.1)

   -  Set Parameters directive (see Section 8.7.7.5) for URI (see
      Section 8.7.5.13)

   -  Fetch directive (see Section 8.7.7.7)

   -  Check Image Match condition (see Section 8.7.6.2)

   The Fetch directive needs the URI parameter to be set to determine
   where the image is retrieved from.  Additionally, the destination of
   where the component shall be stored has to be configured.  The URI is
   configured via the Set Parameters directive while the destination is
   configured via the Set Component Index directive.

   Optionally, the Set Parameters directive in the install sequence MAY
   also contain Encryption Info (see Section 8.7.5.10), Compression Info
   (see Section 8.7.5.11), or Unpack Info (see Section 8.7.5.12) to
   perform simultaneous download and decryption, decompression, or
   unpacking, respectively.

7.4.  Install Template

   The goal of the Install template is to use an image already stored in
   an identified component to copy into a second component.

   This template is typically used with the Component Download template,
   however a modification to that template is required: the Component
   Download operations are moved from the Payload Install sequence to
   the Payload Fetch sequence.

   Then, the install sequence contains the following commands:

   -  Set Component Index directive (see Section 8.7.7.1)

   -  Set Parameters directive (see Section 8.7.7.5) for Source
      Component (see Section 8.7.5.14)

   -  Copy directive (see Section 8.7.7.9)

   -  Check Image Match condition (see Section 8.7.6.2)

7.5.  Install and Transform Template

   The goal of the Install and Transform template is to use an image
   already stored in an identified component to decompress, decrypt, or
   unpack at time of installation.

   This template is typically used with the Component Download template,
   however a modification to that template is required: all Component
   Download operations are moved from the common sequence and the
   install sequence to the fetch sequence.  The Component Download
   template targets a download component identifier, while the Install
   and Transform template uses an install component identifier.  In-
   place unpacking, decompression, and decryption is complex and
   vulnerable to power failure.  Therefore, these identifiers SHOULD be
   different; in-place installation SHOULD NOT be used without
   establishing guarantees of robustness to power failure.

   The following commands are placed into the common sequence:

   -  Set Component Index directive for install component identifier
      (see Section 8.7.7.1)

   -  Override Parameters directive (see Section 8.7.7.6) for Image
      Digest and Image Size (see Section 8.7.5)

   Then, the install sequence contains the following commands:

   -  Set Component Index directive for install component identifier
      (see Section 8.7.7.1)

   -  Set Parameters directive (see Section 8.7.7.5) for:

      o  Source Component for download component identifier (see
         Section 8.7.5.14)

      o  Encryption Info (see Section 8.7.5.10)

      o  Compression Info (see Section 8.7.5.11)

      o  Unpack Info (see Section 8.7.5.12)

   -  Copy directive (see Section 8.7.7.9)

   -  Check Image Match condition (see Section 8.7.6.2)

7.6.  Integrated Payload Template

   The goal of the Integrated Payload template is to install a payload
   that is included in the manifest envelope.  It is identical to the
   Component Download template (Section 7.3) except that it places an
   added restriction on the URI passed to the Set Parameters directive.

   An implementer MAY choose to place a payload in the envelope of a
   manifest.  The payload envelope key MAY be a positive or negative
   integer.  The payload envelope key MUST NOT be a value between 0 and
   24 and it MUST NOT be used by any other envelope element in the
   manifest.  The payload MUST be serialized in a bstr element.

   The URI for a payload enclosed in this way MUST be expressed as a
   fragment-only reference, as defined in [RFC3986], Section 4.4.  The
   fragment identifier is the stringified envelope key of the payload.
   For example, an envelope that contains a payload a key 42 would use a
   URI "#42", key -73 would use a URI "#-73".

7.7.  Load from Nonvolatile Storage Template

   The goal of the Load from Nonvolatile Storage template is to load an
   image from a non-volatile component into a volatile component, for
   example loading a firmware image from external Flash into RAM.

   The following commands are placed into the load sequence:

   -  Set Component Index directive (see Section 8.7.7.1)

   -  Set Parameters directive (see Section 8.7.7.5) for Component Index
      (see Section 8.7.5)

   -  Copy directive (see Section 8.7.7.9)

   As outlined in Section 6.4, the Copy directive needs a source and a
   destination to be configured.  The source is configured via Component
   Index (with the Set Parameters directive) and the destination is
   configured via the Set Component Index directive.

7.8.  Load & Decompress from Nonvolatile Storage Template

   The goal of the Load & Decompress from Nonvolatile Storage template
   is to load an image from a non-volatile component into a volatile
   component, decompressing on-the-fly, for example loading a firmware
   image from external Flash into RAM.

   The following commands are placed into the load sequence:

   -  Set Component Index directive (see Section 8.7.7.1)

   -  Set Parameters directive (see Section 8.7.7.5) for Source
      Component Index and Compression Info (see Section 8.7.5)

   -  Copy directive (see Section 8.7.7.9)

   This template is similar to Section 7.7 but additionally performs
   decompression.  Hence, the only difference is in setting the
   Compression Info parameter.

   This template can be modified for decryption or unpacking by adding
   Decryption Info or Unpack Info to the Set Parameters directive.

7.9.  Dependency Template

   The goal of the Dependency template is to obtain, verify, and process
   a dependency manifest as appropriate.

   The following commands are placed into the dependency resolution
   sequence:

   -  Set Dependency Index directive (see Section 8.7.7.2)

   -  Set Parameters directive (see Section 8.7.7.5) for URI (see
      Section 8.7.5)

   -  Fetch directive (see Section 8.7.7.7)

   -  Check Image Match condition (see Section 8.7.6.2)

   -  Process Dependency directive (see Section 8.7.7.4)

   Then, the validate sequence contains the following operations:

   -  Set Dependency Index directive (see Section 8.7.7.2)

   -  Check Image Match condition (see Section 8.7.6.2)

   -  Process Dependency directive (see Section 8.7.7.4)

   NOTE: Any changes made to parameters in a dependency persist in the
   dependent.

7.9.1.  Composite Manifests

   An implementer MAY choose to place a dependency's envelope in the
   envelope of its dependent.  The dependent envelope key for the
   dependency envelope MUST NOT be a value between 0 and 24 and it MUST
   NOT be used by any other envelope element in the dependent manifest.

   The URI for a dependency enclosed in this way MUST be expressed as a
   fragment-only reference, as defined in [RFC3986], Section 4.4.  The
   fragment identifier is the stringified envelope key of the
   dependency.  For example, an envelope that contains a dependency at
   key 42 would use a URI "#42", key -73 would use a URI "#-73".

7.10.  Encrypted Manifest Template

   The goal of the Encrypted Manifest template is to fetch and decrypt a
   manifest so that it can be used as a dependency.  To use an encrypted
   manifest, create a plaintext dependent, and add the encrypted
   manifest as a dependency.  The dependent can include very little
   information.

   The following operations are placed into the dependency resolution
   block:

   -  Set Dependency Index directive (see Section 8.7.7.2)

   -  Set Parameters directive (see Section 8.7.7.5) for

      o  URI (see Section 8.7.5)

      o  Encryption Info (see Section 8.7.5)

   -  Fetch directive (see Section 8.7.7.7)

   -  Check Image Match condition (see Section 8.7.6.2)

   -  Process Dependency directive (see Section 8.7.7.4)

   Then, the validate block contains the following operations:

   -  Set Dependency Index directive (see Section 8.7.7.2)

   -  Check Image Match condition (see Section 8.7.6.2)

   -  Process Dependency directive (see Section 8.7.7.4)

   A plaintext manifest and its encrypted dependency may also form a
   composite manifest (Section 7.9.1).

7.11.  A/B Image Template

   The goal of the A/B Image Template is to acquire, validate, and
   invoke one of two images, based on a test.

   The following commands are placed in the common block:

   -  Set Component Index directive (see Section 8.7.7.1)

   -  Try Each

      o  First Sequence:

         *  Override Parameters directive (see Section 8.7.7.6,
            Section 8.7.5) for Offset Slot A

         *  Check Offset Slot Condition (see Section 8.7.6.5)

         *  Override Parameters directive (see Section 8.7.7.6) for
            Image Digest A and Image Size A (see Section 8.7.5)

      o  Second Sequence:

         *  Override Parameters directive (see Section 8.7.7.6,
            Section 8.7.5) for Offset Slot B

         *  Check Offset Slot Condition (see Section 8.7.6.5)

         *  Override Parameters directive (see Section 8.7.7.6) for
            Image Digest B and Image Size B (see Section 8.7.5)

   The following commands are placed in the fetch block or install block

   -  Set Component Index directive (see Section 8.7.7.1)

   -  Try Each

      o  First Sequence:

         *  Override Parameters directive (see Section 8.7.7.6,
            Section 8.7.5) for Offset Slot A

         *  Check Offset Slot Condition (see Section 8.7.6.5)

         *  Set Parameters directive (see Section 8.7.7.6) for URI A
            (see Section 8.7.5)

      o  Second Sequence:

         *  Override Parameters directive (see Section 8.7.7.6,
            Section 8.7.5) for Offset Slot B

         *  Check Offset Slot Condition (see Section 8.7.6.5)

         *  Set Parameters directive (see Section 8.7.7.6) for URI B
            (see Section 8.7.5)

   -  Fetch

   If Trusted Invocation (Section 7.2) is used, only the run sequence is
   added to this template, since the common sequence is populated by
   this template.

   NOTE: Any test can be used to select between images, Check Offset Slot
   Condition is used in this template because it is a typical test for
   execute-in-place devices.

8.  Metadata Structure

   The metadata for SUIT updates is composed of several primary
   constituent parts: the Envelope, Delegation Chains, Authentication
   Information, Manifest, and Severable Elements.

   For a diagram of the metadata structure, see Section 5.

8.1.  Encoding Considerations

   The map indices in the envelope encoding are reset to 1 for each map
   within the structure.  This is to keep the indices as small as
   possible.  The goal is to keep the index objects to single bytes
   (CBOR positive integers 1-23).

   Wherever enumerations are used, they are started at 1.  This allows
   detection of several common software errors that are caused by
   uninitialized variables.  Positive numbers in enumerations are
   reserved for IANA registration.  Negative numbers are used to
   identify application-specific values, as described in Section 11.

   All elements of the envelope must be wrapped in a bstr to minimize
   the complexity of the code that evaluates the cryptographic integrity
   of the element and to ensure correct serialization for integrity and
   authenticity checks.

8.2.  Envelope

   The Envelope contains each of the other primary constituent parts of
   the SUIT metadata.  It allows for modular processing of the manifest
   by ordering components in the expected order of processing.

   The Envelope is encoded as a CBOR Map. Each element of the Envelope
   is enclosed in a bstr, which allows computation of a message digest
   against known bounds.

8.3.  Delegation Chains

   The suit-delegation element MAY carry one or more CBOR Web Tokens
   (CWTs) [RFC8392], with [RFC8747] cnf claims.  They can be used to
   perform enhanced authorization decisions.  The CWTs are arranged into
   a list of lists.  Each list starts with a CWT authorized by a Trust
   Anchor, and finishes with a key used to authenticate the Manifest
   (see Section 8.4).  This allows an Update Authority to delegate from
   a long term Trust Anchor, down through intermediaries, to a delegate
   without any out-of-band provisioning of Trust Anchors or intermediary
   keys.

   A Recipient MAY choose to cache intermediaries and/or delegates.  If
   an Update Distributor knows that a targeted Recipient has cached some
   intermediaries or delegates, it MAY choose to strip any cached
   intermediaries or delegates from the Delegation Chains in order to
   reduce bandwidth and energy.

8.4.  Authenticated Manifests

   The suit-authentication-wrapper contains a list containing a SUIT
   Digest Container (see Section 10 10) and one or more cryptographic
   authentication wrappers for the Manifest.  These blocks are
   implemented as COSE_Mac_Tagged or COSE_Sign_Tagged blocks. structures.  Each
   of these blocks contains a SUIT_Digest of the Manifest.  This enables
   modular processing of the manifest.  The COSE_Mac_Tagged and
   COSE_Sign_Tagged blocks are described in RFC 8152 [RFC8152].  The
   suit-authentication-wrapper MUST come before any element in the
   SUIT_Envelope, except for the OPTIONAL suit-
   delegation, suit-delegation, regardless of
   canonical encoding of CBOR.  All validators MUST reject any
   SUIT_Envelope that begins with any element other than a suit-authentication-wrapper suit-
   authentication-wrapper or suit-delegation.

   A SUIT_Envelope that has not had authentication information added
   MUST still contain the suit-authentication-wrapper element, but the
   content MUST be a list containing only the SUIT_Digest.

   A signing application MUST verify the suit-manifest element against
   the SUIT_Digest prior to signing.

8.5.  Encrypted Manifests

   To use an encrypted manifest, it must be a dependency of a plaintext
   manifest.  This allows fine-grained control of what information is
   accessible to intermediate systems for the purposes of management,
   while still preserving the confidentiality of the manifest contents.
   This also means that a Recipient can process an encrypted manifest in
   the same way as an encrypted payload, allowing code reuse.

   A template for using an encrypted manifest is covered in Encrypted
   Manifest Template (Section 7.10).

8.6.  Manifest

   The manifest contains:

   -  a version number (see Section 8.6.1)

   -  a sequence number (see Section 8.6.2)

   -  a reference URI (see Section 8.6.3)

   -  a common structure with information that is shared between command
      sequences (see Section 8.7.2)

   -  one or more lists of commands that the Recipient should perform
      (see Section 8.7.3)

   -  a reference to the full manifest (see Section 8.6.3)

   -  human-readable text describing the manifest found in the
      SUIT_Envelope (see Section 8.6.4)

   -  a Concise Software Identifier (CoSWID) found in the SUIT_Envelope
      (see Section 8.7.1)

   The CoSWID, Text section, or any Command Sequence of the Update
   Procedure (Dependency Resolution, Image Fetch, Image Installation)
   can be either a CBOR structure or a SUIT_Digest.  In each of these
   cases, the SUIT_Digest provides for a severable element.  Severable
   elements are RECOMMENDED to implement.  In particular, the human-
   readable text SHOULD be severable, since most useful text elements
   occupy more space than a SUIT_Digest, but are not needed by the
   Recipient.  Because SUIT_Digest is a CBOR Array and each severable
   element is a CBOR bstr, it is straight-forward for a Recipient to
   determine whether an element has been severed.  The key used for a
   severable element is the same in the SUIT_Manifest and in the
   SUIT_Envelope so that a Recipient can easily identify the correct
   data in the envelope.  See Section 8.7.9 for more detail.

8.6.1.  suit-manifest-version

   The suit-manifest-version indicates the version of serialization used
   to encode the manifest.  Version 1 is the version described in this
   document. suit-manifest-version is REQUIRED to implement.

8.6.2.  suit-manifest-sequence-number

   The suit-manifest-sequence-number is a monotonically increasing anti-
   rollback counter.  It also helps Recipients to determine which in a
   set of manifests is the "root" manifest in a given update.  Each
   manifest MUST have a sequence number higher than each of its
   dependencies.  Each Recipient MUST reject any manifest that has a
   sequence number lower than its current sequence number.  For
   convenience, an implementer MAY use a UTC timestamp in seconds as the
   sequence number. suit-manifest-sequence-number is REQUIRED to
   implement.

8.6.3.  suit-reference-uri

   suit-reference-uri is a text string that encodes a URI where a full
   version of this manifest can be found.  This is convenient for
   allowing management systems to show the severed elements of a
   manifest when this URI is reported by a Recipient after installation.

8.6.4.  suit-text

   suit-text SHOULD be a severable element. suit-text is a map
   containing two different types of pair:

   -  integer => text

   -  SUIT_Component_Identifier => map

   Each SUIT_Component_Identifier => map entry contains a map of integer
   => text values.  All SUIT_Component_Identifiers present in suit-text
   MUST also be present in suit-common (Section 8.7.2) or the suit-
   common of a dependency.

   suit-text contains all the human-readable information that describes
   any and all parts of the manifest, its payload(s) and its
   resource(s).  The text section is typically severable, allowing
   manifests to be distributed without the text, since end-nodes do not
   require text.  The meaning of each field is described below.

   Each section MAY be present.  If present, each section MUST be as
   described.  Negative integer IDs are reserved for application-
   specific text values.

   The following table describes the text fields available in suit-text:

   +--------------------------------+----------------------------------+
   | CDDL Structure                 | Description                      |
   +--------------------------------+----------------------------------+
   | suit-text-manifest-description | Free text description of the     |
   |                                | manifest                         |
   |                                |                                  |
   | suit-text-update-description   | Free text description of the     |
   |                                | update                           |
   |                                |                                  |
   | suit-text-manifest-json-source | The JSON-formatted document that |
   |                                | was used to create the manifest  |
   |                                |                                  |
   | suit-text-manifest-yaml-source | The YAML ([YAML])-formatted      |
   |                                | document that was used to create |
   |                                | the manifest                     |
   +--------------------------------+----------------------------------+

   The following table describes the text fields available in each map
   identified by a SUIT_Component_Identifier.

   +---------------------------------+---------------------------------+
   | CDDL Structure                  | Description                     |
   +---------------------------------+---------------------------------+
   | suit-text-vendor-name           | Free text vendor name           |
   |                                 |                                 |
   | suit-text-model-name            | Free text model name            |
   |                                 |                                 |
   | suit-text-vendor-domain         | The domain used to create the   |
   |                                 | vendor-id condition             |
   |                                 |                                 |
   | suit-text-model-info            | The information used to create  |
   |                                 | the class-id condition          |
   |                                 |                                 |
   | suit-text-component-description | Free text description of each   |
   |                                 | component in the manifest       |
   |                                 |                                 |
   | suit-text-component-version     | A free text representation of   |
   |                                 | the component version           |
   |                                 |                                 |
   | suit-text-version-required      | A free text expression of the   |
   |                                 | required version number         |
   +---------------------------------+---------------------------------+

   suit-text is OPTIONAL to implement.

8.7.  text-version-required

   suit-text-version-required is used to represent a version-based
   dependency on suit-parameter-version as described in Section 8.7.5.18
   and Section 8.7.6.8.  To describe a version dependency, a Manifest
   Author SHOULD populate the suit-text map with a
   SUIT_Component_Identifier key for the dependency component, and place
   in the corresponding map a suit-text-version-required key with a free
   text expression that is representative of the version constraints
   placed on the dependency.  This text SHOULD be expressive enough that
   a device operator can be expected to understand the dependency.  This
   is a free text field and there are no specific formatting rules.

   By way of example only, to express a dependency on a component "['x',
   'y']", where the version should be any v1.x later than v1.2.5, but
   not v2.0 or above, the author would add the following structure to
   the suit-text element.  Note that this text is in cbor-diag notation.

   [h'78',h'79'] : {
       7 : ">=1.2.5,<2"
   }

8.7.1.  suit-coswid

   suit-coswid contains a Concise Software Identifier (CoSWID) as
   defined in [I-D.ietf-sacm-coswid].  This element SHOULD be made
   severable so that it can be discarded by the Recipient or an
   intermediary if it is not required by the Recipient.

   suit-coswid typically requires no processing by the Recipient.
   However all Recipients MUST NOT fail if a suit-coswid is present.

8.7.2.  suit-common

   suit-common encodes all the information that is shared between each
   of the command sequences, including: suit-dependencies, suit-
   components, and suit-common-sequence. suit-common is REQUIRED to
   implement.

   suit-dependencies is a list of Section 8.7.2.1 blocks that specify
   manifests that must be present before the current manifest can be
   processed. suit-dependencies is OPTIONAL to implement.

   suit-components is a list of SUIT_Component_Identifier
   (Section 8.7.2.2) blocks that specify the component identifiers that
   will be affected by the content of the current manifest. suit-
   components is REQUIRED to implement; at least one manifest in a
   dependency tree MUST contain a suit-components block.

   suit-common-sequence is a SUIT_Command_Sequence to execute prior to
   executing any other command sequence.  Typical actions in suit-
   common-sequence include setting expected Recipient identity and image
   digests when they are conditional (see Section 8.7.7.3 and
   Section 7.11 for more information on conditional sequences). suit-
   common-sequence is RECOMMENDED to implement.  It is REQUIRED if the
   optimizations described in Section 6.2.1 will be used.  Whenever a
   parameter or Try Each command is required by more than one Command
   Sequence, placing that parameter or commamd command in suit-common-sequence
   results in a smaller encoding.

8.7.2.1.  Dependencies

   SUIT_Dependency specifies a manifest that describes a dependency of
   the current manifest.  The Manifest is identified, but the Recipient
   should expect an Envelope when it acquires the dependency.  This is
   because the Manifest is the one invariant element of the Envelope,
   where other elements may change by countersigning, adding
   authentication blocks, or severing elements.

   The suit-dependency-digest specifies the dependency manifest uniquely
   by identifying a particular Manifest structure.  This is identical to
   the digest that would be present as the payload of any suit-
   authentication-block in the dependency's Envelope.  The digest is
   calculated over the Manifest structure instead of the COSE
   Sig_structure or Mac_structure.  This is necessary to ensure that
   removing a signature from a manifest does not break dependencies due
   to missing signature elements.  This is also necessary to support the
   trusted intermediary use case, where an intermediary re-signs the
   Manifest, removing the original signature, potentially with a
   different algorithm, or trading COSE_Sign for COSE_Mac.

   The suit-dependency-prefix element contains a
   SUIT_Component_Identifier (see Section 8.7.2.2).  This specifies the
   scope at which the dependency operates.  This allows the dependency
   to be forwarded on to a component that is capable of parsing its own
   manifests.  It also allows one manifest to be deployed to multiple
   dependent Recipients without those Recipients needing consistent
   component hierarchy.  This element is OPTIONAL for Recipients to
   implement.

   A dependency prefix can be used with a component identifier.  This
   allows complex systems to understand where dependencies need to be
   applied.  The dependency prefix can be used in one of two ways.  The
   first simply prepends the prefix to all Component Identifiers in the
   dependency.

   A dependency prefix can also be used to indicate when a dependency
   manifest needs to be processed by a secondary manifest processor, as
   described in Section 6.9.

8.7.2.2.  SUIT_Component_Identifier

   A component is a unit of code or data that can be targeted by an
   update.  To facilitate composite devices, components are identified
   by a list of CBOR byte strings, which allows construction of
   hierarchical component structures.  A dependency MAY declare a prefix
   to the components defined in the dependency manifest.  Components are
   identified by Component Identifiers, but referenced in commands by
   Component Index; Component Identifiers are arrays of binary strings
   and a Component Index is an index into the array of Component
   Identifiers.

   A Component Identifier can be trivial, such as the simple array
   [h'00'].  It can also represent a filesystem path by encoding each
   segment of the path as an element in the list.  For example, the path
   "/usr/bin/env" would encode to ['usr','bin','env'].

   This hierarchical construction allows a component identifier to
   identify any part of a complex, multi-component system.

8.7.3.  SUIT_Command_Sequence

   A SUIT_Command_Sequence defines a series of actions that the
   Recipient MUST take to accomplish a particular goal.  These goals are
   defined in the manifest and include:

   1.  Dependency Resolution: suit-dependency-resolution is a
       SUIT_Command_Sequence to execute in order to perform dependency
       resolution.  Typical actions include configuring URIs of
       dependency manifests, fetching dependency manifests, and
       validating dependency manifests' contents. suit-dependency-
       resolution is REQUIRED to implement and to use when suit-
       dependencies is present.

   2.  Payload Fetch: suit-payload-fetch is a SUIT_Command_Sequence to
       execute in order to obtain a payload.  Some manifests may include
       these actions in the suit-install section instead if they operate
       in a streaming installation mode.  This is particularly relevant
       for constrained devices without any temporary storage for staging
       the update. suit-payload-fetch is OPTIONAL to implement.

   3.  Payload Installation: suit-install is a SUIT_Command_Sequence to
       execute in order to install a payload.  Typical actions include
       verifying a payload stored in temporary storage, copying a staged
       payload from temporary storage, and unpacking a payload. suit-
       install is OPTIONAL to implement.

   4.  Image Validation: suit-validate is a SUIT_Command_Sequence to
       execute in order to validate that the result of applying the
       update is correct.  Typical actions involve image validation and
       manifest validation. suit-validate is REQUIRED to implement.  If
       the manifest contains dependencies, one process-dependency
       invocation per dependency or one process-dependency invocation
       targeting all dependencies SHOULD be present in validate.

   5.  Image Loading: suit-load is a SUIT_Command_Sequence to execute in
       order to prepare a payload for execution.  Typical actions
       include copying an image from permanent storage into RAM,
       optionally including actions such as decryption or decompression.
       suit-load is OPTIONAL to implement.

   6.  Run or Boot: suit-run is a SUIT_Command_Sequence to execute in
       order to run an image. suit-run typically contains a single
       instruction: either the "run" directive for the invocable
       manifest or the "process dependencies" directive for any
       dependents of the invocable manifest. suit-run is OPTIONAL to
       implement.

   Goals 1,2,3 form the Update Procedure.  Goals 4,5,6 form the
   Invocation Procedure.

   Each Command Sequence follows exactly the same structure to ensure
   that the parser is as simple as possible.

   Lists of commands are constructed from two kinds of element:

   1.  Conditions that MUST be true and any failure is treated as a
       failure of the update/load/invocation

   2.  Directives that MUST be executed.

   Each condition is composed of:

   1.  A command code identifier

   2.  A SUIT_Reporting_Policy (Section 8.7.4)

   Each directive is composed of:

   1.  A command code identifier

   2.  An argument block or a SUIT_Reporting_Policy (Section 8.7.4)

   Argument blocks are consumed only by flow-control directives:

   -  Set Component/Dependency Index

   -  Set/Override Parameters

   -  Try Each

   -  Run Sequence

   Reporting policies provide a hint to the manifest processor of
   whether to add the success or failure of a command to any report that
   it generates.

   Many conditions and directives apply to a given component, and these
   generally grouped together.  Therefore, a special command to set the
   current component index is provided with a matching command to set
   the current dependency index.  This index is a numeric index into the
   Component Identifier tables defined at the beginning of the manifest.

   For the purpose of setting the index, the two Component Identifier
   tables are considered to be concatenated together.

   To facilitate optional conditions, a special directive, suit-
   directive-try-each (Section 8.7.7.3), is provided.  It runs several
   new lists of conditions/directives, one after another, that are
   contained as an argument to the directive.  By default, it assumes
   that a failure of a condition should not indicate a failure of the
   update/invocation, but a parameter is provided to override this
   behavior.  See suit-parameter-soft-failure (Section 8.7.5.23).

8.7.4.  Reporting Policy

   To facilitate construction of Reports that describe the success, or
   failure of a given Procedure, each command is given a Reporting
   Policy.  This is an integer bitfield that follows the command and
   indicates what the Recipient should do with the Record of executing
   the command.  The options are summarized in the table below.

   +-----------------------------+-------------------------------------+
   | Policy                      | Description                         |
   +-----------------------------+-------------------------------------+
   | suit-send-record-on-success | Record when the command succeeds    |
   |                             |                                     |
   | suit-send-record-on-failure | Record when the command fails       |
   |                             |                                     |
   | suit-send-sysinfo-success   | Add system information when the     |
   |                             | command succeeds                    |
   |                             |                                     |
   | suit-send-sysinfo-failure   | Add system information when the     |
   |                             | command fails                       |
   +-----------------------------+-------------------------------------+

   Any or all of these policies may be enabled at once.

   At the completion of each command, a Manifest Processor MAY forward
   information about the command to a Reporting Engine, which is
   responsible for reporting boot or update status to a third party.
   The Reporting Engine is entirely implementation-defined, the
   reporting policy simply facilitates the Reporting Engine's interface
   to the SUIT Manifest Processor.

   The information elements provided to the Reporting Engine are:

   -  The reporting policy

   -  The result of the command
   -  The values of parameters consumed by the command

   -  The system information consumed by the command

   Together, these elements are called a Record.  A group of Records is
   a Report.

   If the component index is set to True or an array when a command is
   executed with a non-zero reporting policy, then the Reporting Engine
   MUST receive one Record for each Component, in the order expressed in
   the Components list or the component index array.  If the dependency
   index is set to True or an array when a command is executed with a
   non-zero reporting policy, then the Reporting Engine MUST receive one
   Record for each Dependency, in the order expressed in the
   Dependencies list or the component index array, respectively.

   This specification does not define a particular format of Records or
   Reports.  This specification only defines hints to the Reporting
   Engine for which Records it should aggregate into the Report.  The
   Reporting Engine MAY choose to ignore these hints and apply its own
   policy instead.

   When used in a Invocation Procedure, the report MAY form the basis of
   an attestation report.  When used in an Update Process, the report
   MAY form the basis for one or more log entries.

8.7.5.  SUIT_Parameters

   Many conditions and directives require additional information.  That
   information is contained within parameters that can be set in a
   consistent way.  This allows reduction of manifest size and
   replacement of parameters from one manifest to the next.

   Most parameters are scoped to a specific component.  This means that
   setting a parameter for one component has no effect on the parameters
   of any other component.  The only exceptions to this are two Manifest
   Processor parameters: Strict Order and Soft Failure.

   The defined manifest parameters are described below.

   +----------------+----------------------------------+---------------+
   | Name           | CDDL Structure                   | Reference     |
   +----------------+----------------------------------+---------------+
   | Vendor ID      | suit-parameter-vendor-identifier | Section 8.7.5 |
   |                |                                  | .3            |
   |                |                                  |               |
   | Class ID       | suit-parameter-class-identifier  | Section 8.7.5 |
   |                |                                  | .4            |
   |                |                                  |               |
   | Device ID      | suit-parameter-device-identifier | Section 8.7.5 |
   |                |                                  | .5            |
   |                |                                  |               |
   | Image Digest   | suit-parameter-image-digest      | Section 8.7.5 |
   |                |                                  | .6            |
   |                |                                  |               |
   | Image Size     | suit-parameter-image-size        | Section 8.7.5 |
   |                |                                  | .7            |
   |                |                                  |               |
   | Use Before     | suit-parameter-use-before        | Section 8.7.5 |
   |                |                                  | .8            |
   |                |                                  |               |
   | Component Slot | suit-parameter-component-offset suit-parameter-component-slot    | Section 8.7.5 |
   | Offset                |                                  | .9            |
   |                |                                  |               |
   | Encryption     | suit-parameter-encryption-info   | Section 8.7.5 |
   | Info           |                                  | .10           |
   |                |                                  |               |
   | Compression    | suit-parameter-compression-info  | Section 8.7.5 |
   | Info           |                                  | .11           |
   |                |                                  |               |
   | Unpack Info    | suit-parameter-unpack-info       | Section 8.7.5 |
   |                |                                  | .12           |
   |                |                                  |               |
   | URI            | suit-parameter-uri               | Section 8.7.5 |
   |                |                                  | .13           |
   |                |                                  |               |
   | Source         | suit-parameter-source-component  | Section 8.7.5 |
   | Component      |                                  | .14           |
   |                |                                  |               |
   | Run Args       | suit-parameter-run-args          | Section 8.7.5 |
   |                |                                  | .15           |
   |                |                                  |               |
   | Minimum        | suit-parameter-minimum-battery   | Section 8.7.5 |
   | Battery        |                                  | .16           |
   |                |                                  |               |
   | Update         | suit-parameter-update-priority   | Section 8.7.5 |
   | Priority       |                                  | .17           |
   |                |                                  |               |
   | Version        | suit-parameter-version           | Section 8.7.5 |
   |                |                                  | .18           |
   |                |                                  |               |
   | Wait Info      | suit-parameter-wait-info         | Section 8.7.5 |
   |                |                                  | .19           |
   |                |                                  |               |
   | URI List       | suit-parameter-uri-list          | Section 8.7.5 |
   |                |                                  | .20           |
   |                |                                  |               |
   | Fetch          | suit-parameter-fetch-arguments   | Section 8.7.5 |
   | Arguments      |                                  | .21           |
   |                |                                  |               |
   | Strict Order   | suit-parameter-strict-order      | Section 8.7.5 |
   |                |                                  | .22           |
   |                |                                  |               |
   | Soft Failure   | suit-parameter-soft-failure      | Section 8.7.5 |
   |                |                                  | .23           |
   |                |                                  |               |
   | Custom         | suit-parameter-custom            | Section 8.7.5 |
   |                |                                  | .24           |
   +----------------+----------------------------------+---------------+

   CBOR-encoded object parameters are still wrapped in a bstr.  This is
   because it allows a parser that is aggregating parameters to
   reference the object with a single pointer and traverse it without
   understanding the contents.  This is important for modularization and
   division of responsibility within a pull parser.  The same
   consideration does not apply to Directives because those elements are
   invoked with their arguments immediately

8.7.5.1.  CBOR PEN UUID Namespace Identifier

   The CBOR PEN UUID Namespace Identifier is constructed as follows:

   It uses the OID Namespace as a starting point, then uses the CBOR OID
   encoding for the IANA PEN OID (1.3.6.1.4.1):

   D8 DE                # tag(111)
      45                # bytes(5)
         2B 06 01 04 01 # X.690 Clause 8.19
   #    1.3  6  1  4  1  show component encoding

   Computing a type 5 UUID from these produces:

   NAMESPACE_CBOR_PEN = UUID5(NAMESPACE_OID, h'D86F452B06010401')
   NAMESPACE_CBOR_PEN = 08cfcc43-47d9-5696-85b1-9c738465760e

8.7.5.2.  Constructing UUIDs

   Several conditions use identifiers to determine whether a manifest
   matches a given Recipient or not.  These identifiers are defined to
   be RFC 4122 [RFC4122] UUIDs.  These UUIDs are not human-readable and
   are therefore used for machine-based processing only.

   A Recipient MAY match any number of UUIDs for vendor or class
   identifier.  This may be relevant to physical or software modules.

   For example, a Recipient that has an OS and one or more applications
   might list one Vendor ID for the OS and one or more additional Vendor
   IDs for the applications.  This Recipient might also have a Class ID
   that must be matched for the OS and one or more Class IDs for the
   applications.

   Identifiers are used for compatibility checks.  They MUST NOT be used
   as assertions of identity.  They are evaluated by identifier
   conditions (Section 8.7.6.1).

   A more complete example: Imagine a device has the following physical
   components: 1.  A host MCU 2.  A WiFi module

   This same device has three software modules: 1.  An operating system
   2.  A WiFi module interface driver 3.  An application

   Suppose that the WiFi module's firmware has a proprietary update
   mechanism and doesn't support manifest processing.  This device can
   report four class IDs:

   1.  Hardware model/revision

   2.  OS

   3.  WiFi module model/revision

   4.  Application

   This allows the OS, WiFi module, and application to be updated
   independently.  To combat possible incompatibilities, the OS class ID
   can be changed each time the OS has a change to its API.

   This approach allows a vendor to target, for example, all devices
   with a particular WiFi module with an update, which is a very
   powerful mechanism, particularly when used for security updates.

   UUIDs MUST be created according to RFC 4122 [RFC4122].  UUIDs SHOULD
   use versions 3, 4, or 5, as described in RFC4122.  Versions 1 and 2
   do not provide a tangible benefit over version 4 for this
   application.

   The RECOMMENDED method to create a vendor ID is:

   Vendor ID = UUID5(DNS_PREFIX, vendor domain name)

   If the Vendor ID is a UUID, the RECOMMENDED method to create a Class
   ID is:

   Class ID = UUID5(Vendor ID, Class-Specific-Information)

   If the Vendor ID is a CBOR PEN (see Section 8.7.5.3), the RECOMMENDED
   method to create a Class ID is:

   Class ID = UUID5(
       UUID5(NAMESPACE_CBOR_PEN, CBOR_PEN),
       Class-Specific-Information)

   Class-specific-information is composed of a variety of data, for
   example:

   -  Model number.

   -  Hardware revision.

   -  Bootloader version (for immutable bootloaders).

8.7.5.3.  suit-parameter-vendor-identifier

   suit-parameter-vendor-identifier may be presented in one of two ways:

   -  A Private Enterprise Number

   -  A byte string containing a UUID ([RFC4122])

   Private Enterprise Numbers are encoded as a relative OID, according
   to the definition in [I-D.ietf-cbor-tags-oid].  All PENs are relative
   to the IANA PEN: 1.3.6.1.4.1.

8.7.5.4.  suit-parameter-class-identifier

   A RFC 4122 UUID representing the class of the device or component.
   The UUID is encoded as a 16 byte bstr, containing the raw bytes of
   the UUID.  It MUST be constructed as described in Section 8.7.5.2

8.7.5.5.  suit-parameter-device-identifier

   A RFC 4122 UUID representing the specific device or component.  The
   UUID is encoded as a 16 byte bstr, containing the raw bytes of the
   UUID.  It MUST be constructed as described in Section 8.7.5.2

8.7.5.6.  suit-parameter-image-digest

   A fingerprint computed over the component itself, encoded in the
   SUIT_Digest Section 10 structure.  The SUIT_Digest is wrapped in a
   bstr, as required in Section 8.7.5.

8.7.5.7.  suit-parameter-image-size

   The size of the firmware image in bytes.  This size is encoded as a
   positive integer.

8.7.5.8.  suit-parameter-use-before

   An expiry date for the use of the manifest encoded as the positive
   integer number of seconds since 1970-01-01.  Implementations that use
   this parameter MUST use a 64-bit internal representation of the
   integer.

8.7.5.9.  suit-parameter-component-offset  suit-parameter-component-slot

   This parameter sets the offset in slot index of a component.  Some components
   support multiple possible Slots (offsets into a storage area).  This
   parameter describes the intended Slot to use, identified by its
   offset index
   into the component's storage area.  This offset slot MUST be encoded as a
   positive integer.

8.7.5.10.  suit-parameter-encryption-info

   Encryption Info defines the keys and algorithm information Fetch or
   Copy has to use to decrypt the confidentiality protected data.
   SUIT_Parameter_Encryption_Info is encoded as a COSE_Encrypt_Tagged
   structure wrapped in a bstr.  A separate document will profile the
   COSE specification for use of manifest and firmware encrytion.

8.7.5.11.  suit-parameter-compression-info

   SUIT_Compression_Info defines any information that is required for a
   Recipient to perform decompression operations.  SUIT_Compression_Info
   is a map containing this data.  The only element defined for the map
   in this specification is the suit-compression-algorithm.  This
   document defines the following suit-compression-algorithm's: ZLIB
   [RFC1950], Brotli [RFC7932], and ZSTD [I-D.kucherawy-rfc8478bis]. [RFC8878].

   Additional suit-compression-algorithm's can be registered through the
   IANA-maintained registry.  If such a format requires more data than
   an algorithm identifier, one or more new elements MUST be introduced
   by specifying an element for SUIT_Compression_Info-extensions.

8.7.5.12.  suit-parameter-unpack-info

   SUIT_Unpack_Info defines the information required for a Recipient to
   interpret a packed format.  This document defines the use of the
   following binary encodings: Intel HEX [HEX], Motorola S-record

   [SREC], Executable and Linkable Format (ELF) [ELF], and Common Object
   File Format (COFF) [COFF].

   Additional packing formats can be registered through the IANA-
   maintained registry.

8.7.5.13.  suit-parameter-uri

   A URI from which to fetch a resource, encoded as a text string.  CBOR
   Tag 32 is not used because the meaning of the text string is
   unambiguous in this context.

8.7.5.14.  suit-parameter-source-component

   This parameter sets the source component to be used with either suit-
   directive-copy (Section 8.7.7.9) or with suit-directive-swap
   (Section 8.7.7.13).  The current Component, as set by suit-directive-
   set-component-index defines the destination, and suit-parameter-
   source-component defines the source.

8.7.5.15.  suit-parameter-run-args

   This parameter contains an encoded set of arguments for suit-
   directive-run (Section 8.7.7.10).  The arguments MUST be provided as
   an implementation-defined bstr.

8.7.5.16.  suit-parameter-minimum-battery

   This parameter sets the minimum battery level in mWh.  This parameter
   is encoded as a positive integer.  Used with suit-condition-minimum-
   battery (Section 8.7.6.6).

8.7.5.17.  suit-parameter-update-priority

   This parameter sets the priority of the update.  This parameter is
   encoded as an integer.  It is used along with suit-condition-update-
   authorized (Section 8.7.6.7) to ask an application for permission to
   initiate an update.  This does not constitute a privilege inversion
   because an explicit request for authorization has been provided by
   the Update Authority in the form of the suit-condition-update-
   authorized command.

   Applications MAY define their own meanings for the update priority.
   For example, critical reliability & vulnerability fixes MAY be given
   negative numbers, while bug fixes MAY be given small positive
   numbers, and feature additions MAY be given larger positive numbers,
   which allows an application to make an informed decision about
   whether and when to allow an update to proceed.

8.7.5.18.  suit-parameter-version

   Indicates allowable versions for the specified component.  Allowable
   versions can be specified, either with a list or with range matching.
   This parameter is compared with version asserted by the current
   component when suit-condition-version (Section 8.7.6.8) is invoked.
   The current component may assert the current version in many ways,
   including storage in a parameter storage database, in a metadata
   object, or in a known location within the component itself.

   The component version can be compared as:

   -  Greater.

   -  Greater or Equal.

   -  Equal.

   -  Lesser or Equal.

   -  Lesser.

   Versions are encoded as a CBOR list of integers.  Comparisons are
   done on each integer in sequence.  Comparison stops after all
   integers in the list defined by the manifest have been consumed OR
   after a non-equal match has occurred.  For example, if the manifest
   defines a comparison, "Equal [1]", then this will match all version
   sequences starting with 1.  If a manifest defines both "Greater or
   Equal [1,0]" and "Lesser [1,10]", then it will match versions 1.0.x
   up to, but not including 1.10.

   While the exact encoding of versions is application-defined, semantic
   versions map conveniently.  For example,

   -  1.2.3 = [1,2,3].

   -  1.2-rc3 = [1,2,-1,3].

   -  1.2-beta = [1,2,-2].

   -  1.2-alpha = [1,2,-3].

   -  1.2-alpha4 = [1,2,-3,4].

   suit-condition-version is OPTIONAL to implement.

   Versions SHOULD be provided as follows:

   1.  The first integer represents the major number.  This indicates
       breaking changes to the component.

   2.  The second integer represents the minor number.  This is
       typically reserved for new features or large, non-breaking
       changes.

   3.  The third integer is the patch version.  This is typically
       reserved for bug fixes.

   4.  The fourth integer is the build number.

   Where Alpha (-3), Beta (-2), and Release Candidate (-1) are used,
   they are inserted as a negative number between Minor and Patch
   numbers.  This allows these releases to compare correctly with final
   releases.  For example, Version 2.0, RC1 should be lower than Version
   2.0.0 and higher than any Version 1.x.  By encoding RC as -1, this
   works correctly: [2,0,-1,1] compares as lower than [2,0,0].
   Similarly, beta (-2) is lower than RC and alpha (-3) is lower than
   RC.

8.7.5.19.  suit-parameter-wait-info

   suit-directive-wait (Section 8.7.7.11) directs the manifest processor
   to pause until a specified event occurs.  The suit-parameter-wait-
   info encodes the parameters needed for the directive.

   The exact implementation of the pause is implementation-defined.  For
   example, this could be done by blocking on a semaphore, registering
   an event handler and suspending the manifest processor, polling for a
   notification, or aborting the update entirely, then restarting when a
   notification is received.

   suit-parameter-wait-info is encoded as a map of wait events.  When
   ALL wait events are satisfied, the Manifest Processor continues.  The
   wait events currently defined are described in the following table.

   +------------------------------+---------+--------------------------+
   | Name                         | Encodin | Description              |
   |                              | g       |                          |
   +------------------------------+---------+--------------------------+
   | suit-wait-event-             | int     | Same as suit-parameter-  |
   | authorization                |         | update-priority          |
   |                              |         |                          |
   | suit-wait-event-power        | int     | Wait until power state   |
   |                              |         |                          |
   | suit-wait-event-network      | int     | Wait until network state |
   |                              |         |                          |
   | suit-wait-event-other-       | See     | Wait for other device to |
   | device-version               | below   | match version            |
   |                              |         |                          |
   | suit-wait-event-time         | uint    | Wait until time (seconds |
   |                              |         | since 1970-01-01)        |
   |                              |         |                          |
   | suit-wait-event-time-of-day  | uint    | Wait until seconds since |
   |                              |         | 00:00:00                 |
   |                              |         |                          |
   | suit-wait-event-time-of-day- | uint    | Wait until seconds since |
   | utc                          |         | 00:00:00 UTC             |
   |                              |         |                          |
   | suit-wait-event-day-of-week  | uint    | Wait until days since    |
   |                              |         | Sunday                   |
   |                              |         |                          |
   | suit-wait-event-day-of-week- | uint    | Wait until days since    |
   | utc                          |         | Sunday UTC               |
   +------------------------------+---------+--------------------------+

   suit-wait-event-other-device-version reuses the encoding of suit-
   parameter-version-match.  It is encoded as a sequence that contains
   an implementation-defined bstr identifier for the other device, and a
   list of one or more SUIT_Parameter_Version_Match.

8.7.5.20.  suit-parameter-uri-list

   Indicates a list of URIs from which to fetch a resource.  The URI
   list is encoded as a list of text string, in priority order.  CBOR
   Tag 32 is not used because the meaning of the text string is
   unambiguous in this context.  The Recipient should attempt to fetch
   the resource from each URI in turn, ruling out each, in order, if the
   resource is inaccessible or it is otherwise undesirable to fetch from
   that URI. suit-parameter-uri-list is consumed by suit-directive-
   fetch-uri-list (Section 8.7.7.8).

8.7.5.21.  suit-parameter-fetch-arguments

   An implementation-defined set of arguments to suit-directive-fetch
   (Section 8.7.7.7).  Arguments are encoded in a bstr.

8.7.5.22.  suit-parameter-strict-order

   The Strict Order Parameter allows a manifest to govern when
   directives can be executed out-of-order.  This allows for systems
   that have a sensitivity to order of updates to choose the order in
   which they are executed.  It also allows for more advanced systems to
   parallelize their handling of updates.  Strict Order defaults to
   True.  It MAY be set to False when the order of operations does not
   matter.  When arriving at the end of a command sequence, ALL commands
   MUST have completed, regardless of the state of
   SUIT_Parameter_Strict_Order.  SUIT_Process_Dependency must preserve
   and restore the state of SUIT_Parameter_Strict_Order.  If
   SUIT_Parameter_Strict_Order is returned to True, ALL preceding
   commands MUST complete before the next command is executed.

   See Section 6.7 for behavioral description of Strict Order.

8.7.5.23.  suit-parameter-soft-failure

   When executing a command sequence inside suit-directive-try-each
   (Section 8.7.7.3) or suit-directive-run-sequence (Section 8.7.7.12)
   and a condition failure occurs, the manifest processor aborts the
   sequence.  For suit-directive-try-each, if Soft Failure is True, the
   next sequence in Try Each is invoked, otherwise suit-directive-try-
   each fails with the condition failure code.  In suit-directive-run-
   sequence, if Soft Failure is True the suit-directive-run-sequence
   simply halts with no side-effects and the Manifest Processor
   continues with the following command, otherwise, the suit-directive-
   run-sequence fails with the condition failure code.

   suit-parameter-soft-failure is scoped to the enclosing
   SUIT_Command_Sequence.  Its value is discarded when
   SUIT_Command_Sequence terminates.  It MUST NOT be set outside of
   suit-directive-try-each or suit-directive-run-sequence.

   When suit-directive-try-each is invoked, Soft Failure defaults to
   True.  An Update Author may choose to set Soft Failure to False if
   they require a failed condition in a sequence to force an Abort.

   When suit-directive-run-sequence is invoked, Soft Failure defaults to
   False.  An Update Author may choose to make failures soft within a
   suit-directive-run-sequence.

8.7.5.24.  suit-parameter-custom

   This parameter is an extension point for any proprietary, application
   specific conditions and directives.  It MUST NOT be used in the
   common sequence.  This effectively scopes each custom command to a
   particular Vendor Identifier/Class Identifier pair.

8.7.6.  SUIT_Condition

   Conditions are used to define mandatory properties of a system in
   order for an update to be applied.  They can be pre-conditions or
   post-conditions of any directive or series of directives, depending
   on where they are placed in the list.  All Conditions specify a
   Reporting Policy as described Section 8.7.4.  Conditions include:

   +----------------+----------------------------------+---------------+
   | Name           | CDDL Structure                   | Reference     |
   +----------------+----------------------------------+---------------+
   | Vendor         | suit-condition-vendor-identifier | Section 8.7.6 |
   | Identifier     |                                  | .1            |
   |                |                                  |               |
   | Class          | suit-condition-class-identifier  | Section 8.7.6 |
   | Identifier     |                                  | .1            |
   |                |                                  |               |
   | Device         | suit-condition-device-identifier | Section 8.7.6 |
   | Identifier     |                                  | .1            |
   |                |                                  |               |
   | Image Match    | suit-condition-image-match       | Section 8.7.6 |
   |                |                                  | .2            |
   |                |                                  |               |
   | Image Not      | suit-condition-image-not-match   | Section 8.7.6 |
   | Match          |                                  | .3            |
   |                |                                  |               |
   | Use Before     | suit-condition-use-before        | Section 8.7.6 |
   |                |                                  | .4            |
   |                |                                  |               |
   | Component Slot | suit-condition-component-offset suit-condition-component-slot    | Section 8.7.6 |
   | Offset                |                                  | .5            |
   |                |                                  |               |
   | Minimum        | suit-condition-minimum-battery   | Section 8.7.6 |
   | Battery        |                                  | .6            |
   |                |                                  |               |
   | Update         | suit-condition-update-authorized | Section 8.7.6 |
   | Authorized     |                                  | .7            |
   |                |                                  |               |
   | Version        | suit-condition-version           | Section 8.7.6 |
   |                |                                  | .8            |
   |                |                                  |               |
   | Abort          | suit-condition-abort             | Section 8.7.6 |
   |                |                                  | .9            |
   |                |                                  |               |
   | Custom         | suit-condition-custom            | Section 8.7.6 |
   | Condition      |                                  | .10           |
   +----------------+----------------------------------+---------------+

   The abstract description of these conditions is defined in
   Section 6.4.

   Conditions compare parameters against properties of the system.
   These properties may be asserted in many different ways, including:
   calculation on-demand, volatile definition in memory, static
   definition within the manifest processor, storage in known location
   within an image, storage within a key storage system, storage in One-
   Time-Programmable memory, inclusion in mask ROM, or inclusion as a
   register in hardware.  Some of these assertion methods are global in
   scope, such as a hardware register, some are scoped to an individual
   component, such as storage at a known location in an image, and some
   assertion methods can be either global or component-scope, based on
   implementation.

   Each condition MUST report a result code on completion.  If a
   condition reports failure, then the current sequence of commands MUST
   terminate.  A subsequent command or command sequence MAY continue
   executing if suit-parameter-soft-failure (Section 8.7.5.23) is set.
   If a condition requires additional information, this MUST be
   specified in one or more parameters before the condition is executed.
   If a Recipient attempts to process a condition that expects
   additional information and that information has not been set, it MUST
   report a failure.  If a Recipient encounters an unknown condition, it
   MUST report a failure.

   Condition labels in the positive number range are reserved for IANA
   registration while those in the negative range are custom conditions
   reserved for proprietary definition by the author of a manifest
   processor.  See Section 11 for more details.

8.7.6.1.  suit-condition-vendor-identifier, suit-condition-class-
          identifier, and suit-condition-device-identifier

   There are three identifier-based conditions: suit-condition-vendor-
   identifier, suit-condition-class-identifier, and suit-condition-
   device-identifier.  Each of these conditions match a RFC 4122
   [RFC4122] UUID that MUST have already been set as a parameter.  The
   installing Recipient MUST match the specified UUID in order to
   consider the manifest valid.  These identifiers are scoped by
   component in the manifest.  Each component MAY match more than one
   identifier.  Care is needed to ensure that manifests correctly
   identify their targets using these conditions.  Using only a generic
   class ID for a device-specific firmware could result in matching
   devices that are not compatible.

   The Recipient uses the ID parameter that has already been set using
   the Set Parameters directive.  If no ID has been set, this condition
   fails. suit-condition-class-identifier and suit-condition-vendor-
   identifier are REQUIRED to implement. suit-condition-device-
   identifier is OPTIONAL to implement.

   Each identifier condition compares the corresponding identifier
   parameter to a parameter asserted to the Manifest Processor by the
   Recipient.  Identifiers MUST be known to the Manifest Processor in
   order to evaluate compatibility.

8.7.6.2.  suit-condition-image-match

   Verify that the current component matches the suit-parameter-image-
   digest (Section 8.7.5.6) for the current component.  The digest is
   verified against the digest specified in the Component's parameters
   list.  If no digest is specified, the condition fails. suit-
   condition-image-match is REQUIRED to implement.

8.7.6.3.  suit-condition-image-not-match

   Verify that the current component does not match the suit-parameter-
   image-digest (Section 8.7.5.6).  If no digest is specified, the
   condition fails. suit-condition-image-not-match is OPTIONAL to
   implement.

8.7.6.4.  suit-condition-use-before

   Verify that the current time is BEFORE the specified time. suit-
   condition-use-before is used to specify the last time at which an
   update should be installed.  The recipient evaluates the current time
   against the suit-parameter-use-before parameter (Section 8.7.5.8),
   which must have already been set as a parameter, encoded as seconds
   after 1970-01-01 00:00:00 UTC.  Timestamp conditions MUST be
   evaluated in 64 bits, regardless of encoded CBOR size. suit-
   condition-use-before is OPTIONAL to implement.

8.7.6.5.  suit-condition-component-offset  suit-condition-component-slot

   Verify that the offset slot index of the current component matches the offset slot
   index set in suit-parameter-component-offset suit-parameter-component-slot (Section 8.7.5.9).  This
   condition allows a manifest to select between several images to match
   a target offset. slot.

8.7.6.6.  suit-condition-minimum-battery

   suit-condition-minimum-battery provides a mechanism to test a
   Recipient's battery level before installing an update.  This
   condition is primarily for use in primary-cell applications, where
   the battery is only ever discharged.  For batteries that are charged,
   suit-directive-wait is more appropriate, since it defines a "wait"
   until the battery level is sufficient to install the update. suit-
   condition-minimum-battery is specified in mWh. suit-condition-
   minimum-battery is OPTIONAL to implement. suit-condition-minimum-
   battery consumes suit-parameter-minimum-battery (Section 8.7.5.16).

8.7.6.7.  suit-condition-update-authorized

   Request Authorization from the application and fail if not
   authorized.  This can allow a user to decline an update. suit-
   parameter-update-priority (Section 8.7.5.17) provides an integer
   priority level that the application can use to determine whether or
   not to authorize the update.  Priorities are application defined.
   suit-condition-update-authorized is OPTIONAL to implement.

8.7.6.8.  suit-condition-version

   suit-condition-version allows comparing versions of firmware.
   Verifying image digests is preferred to version checks because
   digests are more precise. suit-condition-version examines a
   component's version against the version info specified in suit-
   parameter-version (Section 8.7.5.18)

8.7.6.9.  suit-condition-abort

   Unconditionally fail.  This operation is typically used in
   conjunction with suit-directive-try-each (Section 8.7.7.3).

8.7.6.10.  suit-condition-custom

   suit-condition-custom describes any proprietary, application specific
   condition.  This is encoded as a negative integer, chosen by the
   firmware developer.  If additional information must be provided to
   the condition, it should be encoded in a custom parameter (a nint) as
   described in Section 8.7.5.  SUIT_Condition_Custom is OPTIONAL to
   implement.

8.7.7.  SUIT_Directive

   Directives are used to define the behavior of the recipient.
   Directives include:

   +---------------+-------------------------------------+-------------+
   | Name          | CDDL Structure                      | Reference   |
   +---------------+-------------------------------------+-------------+
   | Set Component | suit-directive-set-component-index  | Section 8.7 |
   | Index         |                                     | .7.1        |
   |               |                                     |             |
   | Set           | suit-directive-set-dependency-index | Section 8.7 |
   | Dependency    |                                     | .7.2        |
   | Index         |                                     |             |
   |               |                                     |             |
   | Try Each      | suit-directive-try-each             | Section 8.7 |
   |               |                                     | .7.3        |
   |               |                                     |             |
   | Process       | suit-directive-process-dependency   | Section 8.7 |
   | Dependency    |                                     | .7.4        |
   |               |                                     |             |
   | Set           | suit-directive-set-parameters       | Section 8.7 |
   | Parameters    |                                     | .7.5        |
   |               |                                     |             |
   | Override      | suit-directive-override-parameters  | Section 8.7 |
   | Parameters    |                                     | .7.6        |
   |               |                                     |             |
   | Fetch         | suit-directive-fetch                | Section 8.7 |
   |               |                                     | .7.7        |
   |               |                                     |             |
   | Fetch URI     | suit-directive-fetch-uri-list       | Section 8.7 |
   | list          |                                     | .7.8        |
   |               |                                     |             |
   | Copy          | suit-directive-copy                 | Section 8.7 |
   |               |                                     | .7.9        |
   |               |                                     |             |
   | Run           | suit-directive-run                  | Section 8.7 |
   |               |                                     | .7.10       |
   |               |                                     |             |
   | Wait For      | suit-directive-wait                 | Section 8.7 |
   | Event         |                                     | .7.11       |
   |               |                                     |             |
   | Run Sequence  | suit-directive-run-sequence         | Section 8.7 |
   |               |                                     | .7.12       |
   |               |                                     |             |
   | Swap          | suit-directive-swap                 | Section 8.7 |
   |               |                                     | .7.13       |
   |               |                                     |             |
   | Garbage Unlink        | suit-directive-garbage-collect suit-directive-unlink               | Section 8.7 |
   | Collect               |                                     | .8          |
   +---------------+-------------------------------------+-------------+

   The abstract description of these commands is defined in Section 6.4.

   When a Recipient executes a Directive, it MUST report a result code.
   If the Directive reports failure, then the current Command Sequence
   MUST be terminated.

8.7.7.1.  suit-directive-set-component-index

   Set Component Index defines the component to which successive
   directives and conditions will apply.  The supplied argument MUST be
   one of three types:

   1.  An unsigned integer (REQUIRED to implement in parser)

   2.  A boolean (REQUIRED to implement in parser ONLY IF 2 or more
       components supported)

   3.  An array of unsigned integers (REQUIRED to implement in parser
       ONLY IF 3 or more components supported)

   If the following commands apply to ONE component, an unsigned integer
   index into the component list is used.  If the following commands
   apply to ALL components, then the boolean value "True" is used
   instead of an index.  If the following commands apply to more than
   one, but not all components, then an array of unsigned integer
   indices into the component list is used.  See Section 6.5 for more
   details.

   If the following commands apply to NO components, then the boolean
   value "False" is used.  When suit-directive-set-dependency-index is
   used, suit-directive-set-component-index = False is implied.  When
   suit-directive-set-component-index is used, suit-directive-set-
   dependency-index = False is implied.

   If component index is set to True when a command is invoked, then the
   command applies to all components, in the order they appear in suit-
   common-components.  When the Manifest Processor invokes a command
   while the component index is set to True, it must execute the command
   once for each possible component index, ensuring that the command
   receives the parameters corresponding to that component index.

8.7.7.2.  suit-directive-set-dependency-index

   Set Dependency Index defines the manifest to which successive
   directives and conditions will apply.  The supplied argument MUST be
   either a boolean or an unsigned integer index into the dependencies,
   or an array of unsigned integer indices into the list of
   dependencies.  If the following directives apply to ALL dependencies,
   then the boolean value "True" is used instead of an index.  If the
   following directives apply to NO dependencies, then the boolean value
   "False" is used.  When suit-directive-set-component-index is used,
   suit-directive-set-dependency-index = False is implied.  When suit-
   directive-set-dependency-index is used, suit-directive-set-component-
   index = False is implied.

   If dependency index is set to True when a command is invoked, then
   the command applies to all dependencies, in the order they appear in
   suit-common-components.  When the Manifest Processor invokes a
   command while the dependency index is set to True, the Manifest
   Processor MUST execute the command once for each possible dependency
   index, ensuring that the command receives the parameters
   corresponding to that dependency index.  If the dependency index is
   set to an array of unsigned integers, then the Manifest Processor
   MUST execute the command once for each listed dependency index,
   ensuring that the command receives the parameters corresponding to
   that dependency index.

   See Section 6.5 for more details.

   Typical operations that require suit-directive-set-dependency-index
   include setting a source URI or Encryption Information, invoking
   "Fetch," or invoking "Process Dependency" for an individual
   dependency.

8.7.7.3.  suit-directive-try-each

   This command runs several SUIT_Command_Sequence instances, one after
   another, in a strict order.  Use this command to implement a "try/
   catch-try/catch" sequence.  Manifest processors MAY implement this
   command.

   suit-parameter-soft-failure (Section 8.7.5.23) is initialized to True
   at the beginning of each sequence.  If one sequence aborts due to a
   condition failure, the next is started.  If no sequence completes
   without condition failure, then suit-directive-try-each returns an
   error.  If a particular application calls for all sequences to fail
   and still continue, then an empty sequence (nil) can be added to the
   Try Each Argument.

   The argument to suit-directive-try-each is a list of
   SUIT_Command_Sequence. suit-directive-try-each does not specify a
   reporting policy.

8.7.7.4.  suit-directive-process-dependency

   Execute the commands in the common section of the current dependency,
   followed by the commands in the equivalent section of the current
   dependency.  For example, if the current section is "fetch payload,"
   this will execute "common" in the current dependency, then "fetch
   payload" in the current dependency.  Once this is complete, the
   command following suit-directive-process-dependency will be
   processed.

   If the current dependency is False, this directive has no effect.  If
   the current dependency is True, then this directive applies to all
   dependencies.  If the current section is "common," then the command
   sequence MUST be terminated with an error.

   When SUIT_Process_Dependency completes, it forwards the last status
   code that occurred in the dependency.

8.7.7.5.  suit-directive-set-parameters

   suit-directive-set-parameters allows the manifest to configure
   behavior of future directives by changing parameters that are read by
   those directives.  When dependencies are used, suit-directive-set-
   parameters also allows a manifest to modify the behavior of its
   dependencies.

   Available parameters are defined in Section 8.7.5.

   If a parameter is already set, suit-directive-set-parameters will
   skip setting the parameter to its argument.  This provides the core
   of the override mechanism, allowing dependent manifests to change the
   behavior of a manifest.

   suit-directive-set-parameters does not specify a reporting policy.

8.7.7.6.  suit-directive-override-parameters

   suit-directive-override-parameters replaces any listed parameters
   that are already set with the values that are provided in its
   argument.  This allows a manifest to prevent replacement of critical
   parameters.

   Available parameters are defined in Section 8.7.5.

   suit-directive-override-parameters does not specify a reporting
   policy.

8.7.7.7.  suit-directive-fetch

   suit-directive-fetch instructs the manifest processor to obtain one
   or more manifests or payloads, as specified by the manifest index and
   component index, respectively.

   suit-directive-fetch can target one or more manifests and one or more
   payloads. suit-directive-fetch retrieves each component and each
   manifest listed in component-index and dependency-index,
   respectively.  If component-index or dependency-index is True,
   instead of an integer, then all current manifest components/manifests
   are fetched.  The current manifest's dependent-components are not
   automatically fetched.  In order to pre-fetch these, they MUST be
   specified in a component-index integer.

   suit-directive-fetch typically takes no arguments unless one is
   needed to modify fetch behavior.  If an argument is needed, it must
   be wrapped in a bstr and set in suit-parameter-fetch-arguments.

   suit-directive-fetch reads the URI parameter to find the source of
   the fetch it performs.

   The behavior of suit-directive-fetch can be modified by setting one
   or more of SUIT_Parameter_Encryption_Info,
   SUIT_Parameter_Compression_Info, SUIT_Parameter_Unpack_Info.  These
   three parameters each activate and configure a processing step that
   can be applied to the data that is transferred during suit-directive-
   fetch.

8.7.7.8.  suit-directive-fetch-uri-list

   suit-directive-fetch-uri-list uses the same semantics as suit-
   directive-fetch (Section 8.7.7.7), except that it iterates over the
   URI List (Section 8.7.5.20) to select a URI to fetch from.

8.7.7.9.  suit-directive-copy

   suit-directive-copy instructs the manifest processor to obtain one or
   more payloads, as specified by the component index.  As described in
   Section 6.5 component index may be a single integer, a list of
   integers, or True. suit-directive-copy retrieves each component
   specified by the current component-index, respectively.  The current
   manifest's dependent-components are not automatically copied.  In
   order to copy these, they MUST be specified in a component-index
   integer.

   The behavior of suit-directive-copy can be modified by setting one or
   more of SUIT_Parameter_Encryption_Info,
   SUIT_Parameter_Compression_Info, SUIT_Parameter_Unpack_Info.  These
   three parameters each activate and configure a processing step that
   can be applied to the data that is transferred during suit-directive-
   copy.

   suit-directive-copy reads its source from suit-parameter-source-
   component (Section 8.7.5.14).

   If either the source component parameter or the source component
   itself is absent, this command fails.

8.7.7.10.  suit-directive-run

   suit-directive-run directs the manifest processor to transfer
   execution to the current Component Index.  When this is invoked, the
   manifest processor MAY be unloaded and execution continues in the
   Component Index.  Arguments are provided to suit-directive-run
   through suit-parameter-run-arguments (Section 8.7.5.15) and are
   forwarded to the executable code located in Component Index in an
   application-specific way.  For example, this could form the Linux
   Kernel Command Line if booting a Linux device.

   If the executable code at Component Index is constructed in such a
   way that it does not unload the manifest processor, then the manifest
   processor may resume execution after the executable completes.  This
   allows the manifest processor to invoke suitable helpers and to
   verify them with image conditions.

8.7.7.11.  suit-directive-wait

   suit-directive-wait directs the manifest processor to pause until a
   specified event occurs.  Some possible events include:

   1.  Authorization

   2.  External Power

   3.  Network availability

   4.  Other Device Firmware Version

   5.  Time

   6.  Time of Day

   7.  Day of Week

8.7.7.12.  suit-directive-run-sequence

   To enable conditional commands, and to allow several strictly ordered
   sequences to be executed out-of-order, suit-directive-run-sequence
   allows the manifest processor to execute its argument as a
   SUIT_Command_Sequence.  The argument must be wrapped in a bstr.

   When a sequence is executed, any failure of a condition causes
   immediate termination of the sequence.

   When suit-directive-run-sequence completes, it forwards the last
   status code that occurred in the sequence.  If the Soft Failure
   parameter is true, then suit-directive-run-sequence only fails when a
   directive in the argument sequence fails.

   suit-parameter-soft-failure (Section 8.7.5.23) defaults to False when
   suit-directive-run-sequence begins.  Its value is discarded when
   suit-directive-run-sequence terminates.

8.7.7.13.  suit-directive-swap

   suit-directive-swap instructs the manifest processor to move the
   source to the destination and the destination to the source
   simultaneously.  Swap has nearly identical semantics to suit-
   directive-copy except that suit-directive-swap replaces the source
   with the current contents of the destination in an application-
   defined way.  As with suit-directive-copy, if the source component is
   missing, this command fails.

   If SUIT_Parameter_Compression_Info or SUIT_Parameter_Encryption_Info
   are present, they MUST be handled in a symmetric way, so that the
   source is decompressed into the destination and the destination is
   compressed into the source.  The source is decrypted into the
   destination and the destination is encrypted into the source. suit-
   directive-swap is OPTIONAL to implement.

8.7.8.  suit-directive-garbage-collect

   suit-directive-garbage-collect  suit-directive-unlink

   suit-directive-unlink marks the current component as unused in the
   current manifest.  This can be used to remove temporary storage or
   remove components that are no longer needed.  Example use cases:

   -  Temporary storage for encrypted download

   -  Temporary storage for verifying decompressed file before writing
      to flash

   -  Removing Trusted Service no longer needed by Trusted Application

   Once the current Command Sequence is complete, the manifest
   processors checks each marked component to see whether any other
   manifests have referenced it.  Those marked components with no other
   references are deleted.  The manifest processor MAY choose to ignore
   a Garbage Collect Unlink directive depending on device policy.

   suit-directive-garbage-collect

   suit-directive-unlink is OPTIONAL to implement in manifest
   processors.

8.7.9.  Integrity Check Values

   When the CoSWID, Text section, or any Command Sequence of the Update
   Procedure is made severable, it is moved to the Envelope and replaced
   with a SUIT_Digest.  The SUIT_Digest is computed over the entire bstr
   enclosing the Manifest element that has been moved to the Envelope.
   Each element that is made severable from the Manifest is placed in
   the Envelope.  The keys for the envelope elements have the same
   values as the keys for the manifest elements.

   Each Integrity Check Value covers the corresponding Envelope Element
   as described in Section 8.8.

8.8.  Severable Elements

   Because the manifest can be used by different actors at different
   times, some parts of the manifest can be removed or "Severed" without
   affecting later stages of the lifecycle.  Severing of information is
   achieved by separating that information from the signed container so
   that removing it does not affect the signature.  This means that
   ensuring integrity of severable parts of the manifest is a
   requirement for the signed portion of the manifest.  Severing some
   parts makes it possible to discard parts of the manifest that are no
   longer necessary.  This is important because it allows the storage
   used by the manifest to be greatly reduced.  For example, no text
   size limits are needed if text is removed from the manifest prior to
   delivery to a constrained device.

   Elements are made severable by removing them from the manifest,
   encoding them in a bstr, and placing a SUIT_Digest of the bstr in the
   manifest so that they can still be authenticated.  The SUIT_Digest
   typically consumes 4 bytes more than the size of the raw digest,
   therefore elements smaller than (Digest Bits)/8 + 4 SHOULD NOT be
   severable.  Elements larger than (Digest Bits)/8 + 4 MAY be
   severable, while elements that are much larger than (Digest Bits)/8 +
   4 SHOULD be severable.

   Because of this, all command sequences in the manifest are encoded in
   a bstr so that there is a single code path needed for all command
   sequences.

9.  Access Control Lists

   To manage permissions in the manifest, there are three models that
   can be used.

   First, the simplest model requires that all manifests are
   authenticated by a single trusted key.  This mode has the advantage
   that only a root manifest needs to be authenticated, since all of its
   dependencies have digests included in the root manifest.

   This simplest model can be extended by adding key delegation without
   much increase in complexity.

   A second model requires an ACL to be presented to the Recipient,
   authenticated by a trusted party or stored on the Recipient.  This
   ACL grants access rights for specific component IDs or Component
   Identifier prefixes to the listed identities or identity groups.  Any
   identity can verify an image digest, but fetching into or fetching
   from a Component Identifier requires approval from the ACL.

   A third model allows a Recipient to provide even more fine-grained
   controls: The ACL lists the Component Identifier or Component
   Identifier prefix that an identity can use, and also lists the
   commands and parameters that the identity can use in combination with
   that Component Identifier.

10.  SUIT Digest Container

   RFC 8152 [RFC8152] provides containers for signature, MAC, and
   encryption, but no basic digest container.

   The container needed for
   a SUIT digest requires is a type CBOR List containing two elements: an algorithm
   identifier and a container for bstr containing the raw
   digest data. bytes of the digest.  Some forms
   of digest may require additional parameters.  These can be added
   following the digest.

   The SUIT digest is a CBOR List containing two elements: a suit-
   digest-algorithm-id and a bstr containing the bytes values of the digest. algorithm identifier are defined by
   [I-D.ietf-cose-hash-algs].  The following algorithms MUST be
   implemented by all Manifest Processors:

   -  SHA-256 (-16)

   The following algorithms MAY be implemented in a Manifest Processor:

   -  SHAKE128 (-18)

   -  SHA-384 (-43)

   -  SHA-512 (-44)

   -  SHAKE256 (-45)

11.  IANA Considerations

   IANA is requested to:

   -  allocate CBOR tag 107 in the CBOR Tags registry for the SUIT
      Envelope.

   -  allocate CBOR tag 1070 in the CBOR Tags registry for the SUIT
      Manifest.

   -  allocate media type application/suit-envelope in the Media Types
      registry.

   -  setup several registries as described below.

   IANA is requested to setup a registry for SUIT manifests.  Several
   registries defined in the subsections below need to be created.

   For each registry, values 0-23 are Standards Action, 24-255 are IETF
   Review, 256-65535 are Expert Review, and 65536 or greater are First
   Come First Served.

   Negative values -23 to 0 are Experimental Use, -24 and lower are
   Private Use.

11.1.  SUIT Commands

   +-------+------------+-----------------------------------+----------+
   | Label | Name       | Reference                         |          |
   +-------+------------+-----------------------------------+----------+
   | 1     | Vendor     | Section 8.7.6.1                   |          |
   |       | Identifier |                                   |          |
   |       |            |                                   |          |
   | 2     | Class      | Section 8.7.6.1                   |          |
   |       | Identifier |                                   |          |
   |       |            |                                   |          |
   | 3     | Image      | Section 8.7.6.2                   |          |
   |       | Match      |                                   |          |
   |       |            |                                   |          |
   | 4     | Use Before | Section 8.7.6.4                   |          |
   |       |            |                                   |          |
   | 5     | Component  | Section 8.7.6.5                   |          |
   |       | Offset Slot       |                                   |          |
   |       |            |                                   |          |
   | 12    | Set        | Section 8.7.7.1                   |          |
   |       | Component  |                                   |          |
   |       | Index      |                                   |          |
   |       |            |                                   |          |
   | 13    | Set        | Section 8.7.7.2                   |          |
   |       | Dependency |                                   |          |
   |       | Index      |                                   |          |
   |       |            |                                   |          |
   | 14    | Abort      |                                   |          |
   |       |            |                                   |          |
   | 15    | Try Each   | Section 8.7.7.3                   |          |
   |       |            |                                   |          |
   | 16    | Reserved   |                                   |          |
   |       |            |                                   |          |
   | 17    | Reserved   |                                   |          |
   |       |            |                                   |          |
   | 18    | Process    | suit-directive-process-dependency | Section  |
   |       | Dependency |                                   | 8.7.7.4  |
   |       |            |                                   |          |
   | 19    | Set        | Section 8.7.7.5                   |          |
   |       | Parameters |                                   |          |
   |       |            |                                   |          |
   | 20    | Override   | Section 8.7.7.6                   |          |
   |       | Parameters |                                   |          |
   |       |            |                                   |          |
   | 21    | Fetch      | Section 8.7.7.7                   |          |
   |       |            |                                   |          |
   | 22    | Copy       | Section 8.7.7.9                   |          |
   |       |            |                                   |          |
   | 23    | Run        | Section 8.7.7.10                  |          |
   |       |            |                                   |          |
   | 24    | Device     | Section 8.7.6.1                   |          |
   |       | Identifier |                                   |          |
   |       |            |                                   |          |
   | 25    | Image Not  | Section 8.7.6.3                   |          |
   |       | Match      |                                   |          |
   |       |            |                                   |          |
   | 26    | Minimum    | Section 8.7.6.6                   |          |
   |       | Battery    |                                   |          |
   |       |            |                                   |          |
   | 27    | Update     | Section 8.7.6.7                   |          |
   |       | Authorized |                                   |          |
   |       |            |                                   |          |
   | 28    | Version    | Section 8.7.6.8                   |          |
   |       |            |                                   |          |
   | 29    | Wait For   | Section 8.7.7.11                  |          |
   |       | Event      |                                   |          |
   |       |            |                                   |          |
   | 30    | Fetch URI  | Section 8.7.7.8                   |          |
   |       | List       |                                   |          |
   |       |            |                                   |          |
   | 31    | Swap       | Section 8.7.7.13                  |          |
   |       |            |                                   |          |
   | 32    | Run        | Section 8.7.7.12                  |          |
   |       | Sequence   |                                   |          |
   |       |            |                                   |          |
   | 33    | Garbage Unlink     | Section 8.7.8                     |          |
   |       | Collect    |                                   |          |
   |       |            |                                   |          |
   | nint  | Custom     | Section 8.7.6.10                  |          |
   |       | Condition  |                                   |          |
   +-------+------------+-----------------------------------+----------+

11.2.  SUIT Parameters
         +-------+------------------+---------------------------+
         | Label | Name             | Reference                 |
         +-------+------------------+---------------------------+
         | 1     | Vendor ID        | Section 8.7.5.3           |
         |       |                  |                           |
         | 2     | Class ID         | Section 8.7.5.4           |
         |       |                  |                           |
         | 3     | Image Digest     | Section 8.7.5.6           |
         |       |                  |                           |
         | 4     | Use Before       | Section 8.7.5.8           |
         |       |                  |                           |
         | 5     | Component Offset Slot   | Section 8.7.5.9           |
         |       |                  |                           |
         | 12    | Strict Order     | Section 8.7.5.22          |
         |       |                  |                           |
         | 13    | Soft Failure     | Section 8.7.5.23          |
         |       |                  |                           |
         | 14    | Image Size       | Section 8.7.5.7           |
         |       |                  |                           |
         | 18    | Encryption Info  | Section 8.7.5.10          |
         |       |                  |                           |
         | 19    | Compression Info | Section 8.7.5.11          |
         |       |                  |                           |
         | 20    | Unpack Info      | Section 8.7.5.12          |
         |       |                  |                           |
         | 21    | URI              | Section 8.7.5.13          |
         |       |                  |                           |
         | 22    | Source Component | Section 8.7.5.14          |
         |       |                  |                           |
         | 23    | Run Args         | Section 8.7.5.15          |
         |       |                  |                           |
         | 24    | Device ID        | Section 8.7.5.5           |
         |       |                  |                           |
         | 26    | Minimum Battery  | Section 8.7.5.16          |
         |       |                  |                           |
         | 27    | Update Priority  | Section 8.7.5.17          |
         |       |                  |                           |
         | 28    | Version          | {{suit-parameter-version} |
         |       |                  |                           |
         | 29    | Wait Info        | Section 8.7.5.19          |
         |       |                  |                           |
         | 30    | URI List         | Section 8.7.5.20          |
         |       |                  |                           |
         | nint  | Custom           | Section 8.7.5.24          |
         +-------+------------------+---------------------------+

11.3.  SUIT Text Values

             +-------+----------------------+---------------+
             | Label | Name                 | Reference     |
             +-------+----------------------+---------------+
             | 1     | Manifest Description | Section 8.6.4 |
             |       |                      |               |
             | 2     | Update Description   | Section 8.6.4 |
             |       |                      |               |
             | 3     | Manifest JSON Source | Section 8.6.4 |
             |       |                      |               |
             | 4     | Manifest YAML Source | Section 8.6.4 |
             |       |                      |               |
             | nint  | Custom               | Section 8.6.4 |
             +-------+----------------------+---------------+

11.4.  SUIT Component Text Values

          +-------+----------------------------+---------------+
          | Label | Name                       | Reference     |
          +-------+----------------------------+---------------+
          | 1     | Vendor Name                | Section 8.6.4 |
          |       |                            |               |
          | 2     | Model Name                 | Section 8.6.4 |
          |       |                            |               |
          | 3     | Vendor Domain              | Section 8.6.4 |
          |       |                            |               |
          | 4     | Model Info                 | Section 8.6.4 |
          |       |                            |               |
          | 5     | Component Description      | Section 8.6.4 |
          |       |                            |               |
          | 6     | Component Version          | Section 8.6.4 |
          |       |                            |               |
          | 7     | Component Version Required | Section 8.6.4 |
          |       |                            |               |
          | nint  | Custom                     | Section 8.6.4 |
          +-------+----------------------------+---------------+

11.5.  SUIT Algorithm Identifiers

11.5.1.  SUIT Digest Compression Algorithm Identifiers
                     +-------+----------+------------+
                   +-------+--------+------------------+
                   | Label | Name   | Reference        |
                     +-------+----------+------------+
                   +-------+--------+------------------+
                   | 1     | SHA224 zlib   | Section 10 8.7.5.11 |
                   |       |        |                  |
                   | 2     | SHA256 Brotli | Section 10 8.7.5.11 |
                   |       |        |                  |
                   | 3     | SHA384   | Section 10 |
                     |       |          |            |
                     | 4     | SHA512 zstd   | Section 10 8.7.5.11 |
                   +-------+--------+------------------+

11.5.2.  Unpack Algorithms

                    +-------+------+------------------+
                    | Label | Name | Reference        |
                    +-------+------+------------------+
                    | 5 1     | SHA3-224 HEX  | Section 10 8.7.5.12 |
                    |       |      |                  |
                    | 6 2     | SHA3-256 ELF  | Section 10 8.7.5.12 |
                    |       |      |                  |
                    | 7 3     | SHA3-384 COFF | Section 10 8.7.5.12 |
                    |       |      |                  |
                    | 8 4     | SHA3-512 SREC | Section 10 |
                     +-------+----------+------------+

11.5.2.  SUIT Compression Algorithm Identifiers

                   +-------+--------+------------------+
                   | Label | Name   | Reference        |
                   +-------+--------+------------------+
                   | 1     | zlib   | Section 8.7.5.11 |
                   |       |        |                  |
                   | 2     | Brotli | Section 8.7.5.11 |
                   |       |        |                  |
                   | 3     | zstd   | Section 8.7.5.11 |
                   +-------+--------+------------------+

11.5.3.  Unpack Algorithms

                    +-------+------+------------------+
                    | Label | Name | Reference        |
                    +-------+------+------------------+
                    | 1     | HEX  | Section 8.7.5.12 |
                    |       |      |                  |
                    | 2     | ELF  | Section 8.7.5.12 |
                    |       |      |                  |
                    | 3     | COFF | Section 8.7.5.12 |
                    |       |      |                  |
                    | 4     | SREC | Section 8.7.5.12 8.7.5.12 |
                    +-------+------+------------------+

12.  Security Considerations

   This document is about a manifest format protecting and describing
   how to retrieve, install, and invoke firmware images and as such it
   is part of a larger solution for delivering firmware updates to IoT
   devices.  A detailed security treatment can be found in the
   architecture [I-D.ietf-suit-architecture] and in the information
   model [I-D.ietf-suit-information-model] documents.

13.  Acknowledgements

   We would like to thank the following persons for their support in
   designing this mechanism:

   -  Milosch Meriac

   -  Geraint Luff

   -  Dan Ros

   -  John-Paul Stanford

   -  Hugo Vincent
   -  Carsten Bormann

   -  Oeyvind Roenningstad

   -  Frank Audun Kvamtroe

   -  Krzysztof Chru&#347;ci&#324;ski

   -  Andrzej Puzdrowski

   -  Michael Richardson

   -  David Brown

   -  Emmanuel Baccelli

14.  References

14.1.  Normative References

   [I-D.ietf-cose-hash-algs]
              Schaad, J., "CBOR Object Signing and Encryption (COSE):
              Hash Algorithms", draft-ietf-cose-hash-algs-09 (work in
              progress), September 2020.

   [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/info/rfc2119>.

   [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,
              <https://www.rfc-editor.org/info/rfc3986>.

   [RFC4122]  Leach, P., Mealling, M., and R. Salz, "A Universally
              Unique IDentifier (UUID) URN Namespace", RFC 4122,
              DOI 10.17487/RFC4122, July 2005,
              <https://www.rfc-editor.org/info/rfc4122>.

   [RFC8152]  Schaad, J., "CBOR Object Signing and Encryption (COSE)",
              RFC 8152, DOI 10.17487/RFC8152, July 2017,
              <https://www.rfc-editor.org/info/rfc8152>.

   [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/info/rfc8174>.

14.2.  Informative References

   [COFF]     Wikipedia, ., "Common Object File Format (COFF)", 2020,
              <https://en.wikipedia.org/wiki/COFF>.

   [ELF]      Wikipedia, ., "Executable and Linkable Format (ELF)",
              2020, <https://en.wikipedia.org/wiki/
              Executable_and_Linkable_Format>.

   [HEX]      Wikipedia, ., "Intel HEX", 2020,
              <https://en.wikipedia.org/wiki/Intel_HEX>.

   [I-D.ietf-cbor-tags-oid]
              Bormann, C., "Concise Binary Object Representation (CBOR)
              Tags for Object Identifiers", draft-ietf-cbor-tags-oid-06
              (work in progress), March 2021.

   [I-D.ietf-sacm-coswid]
              Birkholz, H., Fitzgerald-McKay, J., Schmidt, C., and D.
              Waltermire, "Concise Software Identification Tags", draft-
              ietf-sacm-coswid-17 (work in progress), February 2021.

   [I-D.ietf-suit-architecture]
              Moran, B., Tschofenig, H., Brown, D., and M. Meriac, "A
              Firmware Update Architecture for Internet of Things",
              draft-ietf-suit-architecture-16 (work in progress),
              January 2021.

   [I-D.ietf-suit-information-model]
              Moran, B., Tschofenig, H., and H. Birkholz, "A Manifest
              Information Model for Firmware Updates in IoT Devices",
              draft-ietf-suit-information-model-11 (work in progress),
              April 2021.

   [I-D.ietf-teep-architecture]
              Pei, M., Tschofenig, H., Thaler, D., and D. Wheeler,
              "Trusted Execution Environment Provisioning (TEEP)
              Architecture", draft-ietf-teep-architecture-14 (work in
              progress), February 2021.

   [I-D.kucherawy-rfc8478bis]
              Collet, Y. and M. S. Kucherawy, "Zstandard Compression and
              the 'application/zstd' Media Type", draft-kucherawy-
              rfc8478bis-06 (work in progress), December 2020.

   [RFC1950]  Deutsch, P. and J-L. Gailly, "ZLIB Compressed Data Format
              Specification version 3.3", RFC 1950,
              DOI 10.17487/RFC1950, May 1996,
              <https://www.rfc-editor.org/info/rfc1950>.

   [RFC7228]  Bormann, C., Ersue, M., and A. Keranen, "Terminology for
              Constrained-Node Networks", RFC 7228,
              DOI 10.17487/RFC7228, May 2014,
              <https://www.rfc-editor.org/info/rfc7228>.

   [RFC7932]  Alakuijala, J. and Z. Szabadka, "Brotli Compressed Data
              Format", RFC 7932, DOI 10.17487/RFC7932, July 2016,
              <https://www.rfc-editor.org/info/rfc7932>.

   [RFC8392]  Jones, M., Wahlstroem, E., Erdtman, S., and H. Tschofenig,
              "CBOR Web Token (CWT)", RFC 8392, DOI 10.17487/RFC8392,
              May 2018, <https://www.rfc-editor.org/info/rfc8392>.

   [RFC8747]  Jones, M., Seitz, L., Selander, G., Erdtman, S., and H.
              Tschofenig, "Proof-of-Possession Key Semantics for CBOR
              Web Tokens (CWTs)", RFC 8747, DOI 10.17487/RFC8747, March
              2020, <https://www.rfc-editor.org/info/rfc8747>.

   [RFC8878]  Collet, Y. and M. Kucherawy, Ed., "Zstandard Compression
              and the 'application/zstd' Media Type", RFC 8878,
              DOI 10.17487/RFC8878, February 2021,
              <https://www.rfc-editor.org/info/rfc8878>.

   [SREC]     Wikipedia, ., "SREC (file format)", 2020,
              <https://en.wikipedia.org/wiki/SREC_(file_format)>.

   [YAML]     "YAML Ain't Markup Language", 2020, <https://yaml.org/>.

Appendix A.  A.  Full CDDL

   In order to create a valid SUIT Manifest 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
   [RFC8152], section 1.4.

SUIT_Envelope_Tagged = #6.48(SUIT_Envelope) #6.107(SUIT_Envelope)
SUIT_Envelope = {
  ? suit-delegation => bstr .cbor SUIT_Delegation,
  suit-authentication-wrapper => bstr .cbor SUIT_Authentication,
  suit-manifest  => bstr .cbor SUIT_Manifest,
  SUIT_Severable_Manifest_Members,
  * SUIT_Integrated_Payload,
  * SUIT_Integrated_Dependency,
  * $$SUIT_Envelope_Extensions $$SUIT_Envelope_Extensions,
  * (int => bstr)
}

SUIT_Delegation = [ + SUIT_Delegation_Chain ]

SUIT_Delegation_Chain = [ + bstr .cbor CWT ] ]

CWT = SUIT_Authentication_Block

SUIT_Authentication = [
    bstr .cbor SUIT_Digest,
    * bstr .cbor SUIT_Authentication_Block
]

SUIT_Digest = [
  suit-digest-algorithm-id : suit-digest-algorithm-ids, suit-cose-hash-algs,
  suit-digest-bytes : bstr,
  * $$SUIT_Digest-extensions
]

; Named Information Hash Algorithm Identifiers
suit-digest-algorithm-ids /= algorithm-id-sha224
suit-digest-algorithm-ids /= algorithm-id-sha256
suit-digest-algorithm-ids /= algorithm-id-sha384
suit-digest-algorithm-ids /= algorithm-id-sha512
suit-digest-algorithm-ids /= algorithm-id-sha3-224
suit-digest-algorithm-ids /= algorithm-id-sha3-256
suit-digest-algorithm-ids /= algorithm-id-sha3-384
suit-digest-algorithm-ids /= algorithm-id-sha3-512

SUIT_Authentication_Block /= COSE_Mac_Tagged
SUIT_Authentication_Block /= COSE_Sign_Tagged
SUIT_Authentication_Block /= COSE_Mac0_Tagged
SUIT_Authentication_Block /= COSE_Sign1_Tagged

SUIT_Severable_Manifest_Members = (
  ? suit-dependency-resolution => bstr .cbor SUIT_Command_Sequence,
  ? suit-payload-fetch => bstr .cbor SUIT_Command_Sequence,
  ? suit-install => bstr .cbor SUIT_Command_Sequence,
  ? suit-text => bstr .cbor SUIT_Text_Map,
  ? suit-coswid => bstr ;.cbor .cbor concise-software-identity,
  * $$SUIT_severable-members-extensions,
)

SUIT_Integrated_Payload = (suit-integrated-payload-key => bstr)
SUIT_Integrated_Dependency = (
    suit-integrated-payload-key
    suit-integrated-dependency-key => bstr .cbor SUIT_Envelope
)
suit-integrated-payload-key = nint / uint .ge 24
suit-integrated-dependency-key = suit-integrated-payload-key

SUIT_Manifest_Tagged = #6.480(SUIT_Manifest) #6.1070(SUIT_Manifest)

SUIT_Manifest = {
    suit-manifest-version         => 1,
    suit-manifest-sequence-number => uint,
    suit-common                   => bstr .cbor SUIT_Common,
    ? suit-reference-uri          => tstr,
    SUIT_Severable_Manifest_Members,
    SUIT_Severable_Members_Digests,
    SUIT_Severable_Members_Choice,
    SUIT_Unseverable_Members,
    * $$SUIT_Manifest_Extensions,
}

SUIT_Unseverable_Members = (
  ? suit-validate => bstr .cbor SUIT_Command_Sequence,
  ? suit-load => bstr .cbor SUIT_Command_Sequence,
  ? suit-run => bstr .cbor SUIT_Command_Sequence,
  * $$unserverble-manifest-member-extensions, $$unseverable-manifest-member-extensions,
)

SUIT_Severable_Members_Digests

SUIT_Severable_Members_Choice = (
  ? suit-dependency-resolution => \
    bstr .cbor SUIT_Command_Sequence / SUIT_Digest,
  ? suit-payload-fetch => \
    bstr .cbor SUIT_Command_Sequence / SUIT_Digest,
  ? suit-install => bstr .cbor SUIT_Command_Sequence / SUIT_Digest,
  ? suit-text => bstr .cbor SUIT_Command_Sequence / SUIT_Digest,
  ? suit-coswid => bstr .cbor SUIT_Command_Sequence / SUIT_Digest,
  * $$severable-manifest-members-digests-extensions $$severable-manifest-members-choice-extensions
)

SUIT_Common = {
    ? suit-dependencies           => SUIT_Dependencies,
    ? suit-components             => SUIT_Components,
    ? suit-common-sequence        => bstr .cbor SUIT_Common_Sequence,
    * $$SUIT_Common-extensions,
}

SUIT_Dependencies         = [ + SUIT_Dependency ]
SUIT_Components           = [ + SUIT_Component_Identifier ]

;concise-software-identity

concise-software-identity = any

SUIT_Dependency = {
    suit-dependency-digest => SUIT_Digest,
    ? suit-dependency-prefix => SUIT_Component_Identifier,
    * $$SUIT_Dependency-extensions,
}

;REQUIRED to implement:
suit-cose-hash-algs /= cose-alg-sha-256

;OPTIONAL to implement:
suit-cose-hash-algs /= cose-alg-shake128
suit-cose-hash-algs /= cose-alg-sha-384
suit-cose-hash-algs /= cose-alg-sha-512
suit-cose-hash-algs /= cose-alg-shake256

SUIT_Component_Identifier =  [* bstr]

SUIT_Common_Sequence = [
    + ( SUIT_Condition // SUIT_Common_Commands )
]

SUIT_Common_Commands //= (suit-directive-set-component-index,  IndexArg)
SUIT_Common_Commands //= (suit-directive-set-dependency-index, IndexArg)
SUIT_Common_Commands //= (suit-directive-run-sequence,
    bstr .cbor SUIT_Command_Sequence)
SUIT_Common_Commands //= (suit-directive-try-each,
    SUIT_Directive_Try_Each_Argument)
SUIT_Common_Commands //= (suit-directive-set-parameters,
    {+ SUIT_Parameters})
SUIT_Common_Commands //= (suit-directive-override-parameters,
    {+ SUIT_Parameters})

IndexArg /= uint
IndexArg /= bool
IndexArg /= [+uint]

SUIT_Command_Sequence = [ + (
    SUIT_Condition // SUIT_Directive // SUIT_Command_Custom
) ]

SUIT_Command_Custom = (suit-command-custom, bstr/tstr/int/nil)
SUIT_Condition //= (suit-condition-vendor-identifier, SUIT_Rep_Policy)
SUIT_Condition //= (suit-condition-class-identifier,  SUIT_Rep_Policy)
SUIT_Condition //= (suit-condition-device-identifier, SUIT_Rep_Policy)
SUIT_Condition //= (suit-condition-image-match,       SUIT_Rep_Policy)
SUIT_Condition //= (suit-condition-image-not-match,   SUIT_Rep_Policy)
SUIT_Condition //= (suit-condition-use-before,        SUIT_Rep_Policy)
SUIT_Condition //= (suit-condition-minimum-battery,   SUIT_Rep_Policy)
SUIT_Condition //= (suit-condition-update-authorized, SUIT_Rep_Policy)
SUIT_Condition //= (suit-condition-version,           SUIT_Rep_Policy)
SUIT_Condition //= (suit-condition-component-offset, (suit-condition-component-slot,    SUIT_Rep_Policy)
SUIT_Condition //= (suit-condition-abort,             SUIT_Rep_Policy)

SUIT_Directive //= (suit-directive-set-component-index,  IndexArg)
SUIT_Directive //= (suit-directive-set-dependency-index, IndexArg)
SUIT_Directive //= (suit-directive-run-sequence,
    bstr .cbor SUIT_Command_Sequence)
SUIT_Directive //= (suit-directive-try-each,
    SUIT_Directive_Try_Each_Argument)
SUIT_Directive //= (suit-directive-process-dependency, SUIT_Rep_Policy)
SUIT_Directive //= (suit-directive-set-parameters,
    {+ SUIT_Parameters})
SUIT_Directive //= (suit-directive-override-parameters,
    {+ SUIT_Parameters})
SUIT_Directive //= (suit-directive-fetch,             SUIT_Rep_Policy)
SUIT_Directive //= (suit-directive-copy,              SUIT_Rep_Policy)
SUIT_Directive //= (suit-directive-swap,              SUIT_Rep_Policy)
SUIT_Directive //= (suit-directive-run,               SUIT_Rep_Policy)
SUIT_Directive //= (suit-directive-wait,              SUIT_Rep_Policy)
SUIT_Directive //= (suit-directive-fetch-uri-list,    SUIT_Rep_Policy)
SUIT_Directive //= (suit-directive-garbage-collect, (suit-directive-unlink,            SUIT_Rep_Policy)

SUIT_Directive_Try_Each_Argument = [
    +
    2* bstr .cbor SUIT_Command_Sequence,
    nil / bstr .cbor SUIT_Command_Sequence
    ?nil
]

SUIT_Rep_Policy = uint .bits suit-reporting-bits

suit-reporting-bits = &(
    suit-send-record-success : 0,
    suit-send-record-failure : 1,
    suit-send-sysinfo-success : 2,
    suit-send-sysinfo-failure : 3
)

SUIT_Wait_Event = { + SUIT_Wait_Events }

SUIT_Wait_Events //= (suit-wait-event-authorization => int)
SUIT_Wait_Events //= (suit-wait-event-power => int)
SUIT_Wait_Events //= (suit-wait-event-network => int)
SUIT_Wait_Events //= (suit-wait-event-other-device-version
    => SUIT_Wait_Event_Argument_Other_Device_Version)
SUIT_Wait_Events //= (suit-wait-event-time => uint); Timestamp
SUIT_Wait_Events //= (suit-wait-event-time-of-day
    => uint); Time of Day (seconds since 00:00:00)
SUIT_Wait_Events //= (suit-wait-event-day-of-week
    => uint); Days since Sunday

SUIT_Wait_Event_Argument_Other_Device_Version = [
    other-device: bstr,
    other-device-version: [ + SUIT_Parameter_Version_Match ]
]

SUIT_Parameters //= (suit-parameter-vendor-identifier =>
    (RFC4122_UUID / cbor-pen))
cbor-pen = #6.112(bstr)

SUIT_Parameters //= (suit-parameter-class-identifier => RFC4122_UUID)
SUIT_Parameters //= (suit-parameter-image-digest
    => bstr .cbor SUIT_Digest)
SUIT_Parameters //= (suit-parameter-image-size => uint)
SUIT_Parameters //= (suit-parameter-use-before => uint)
SUIT_Parameters //= (suit-parameter-component-offset (suit-parameter-component-slot => uint)

SUIT_Parameters //= (suit-parameter-encryption-info
    => bstr .cbor SUIT_Encryption_Info)
SUIT_Parameters //= (suit-parameter-compression-info
    => bstr .cbor SUIT_Compression_Info)
SUIT_Parameters //= (suit-parameter-unpack-info
    => bstr .cbor SUIT_Unpack_Info)

SUIT_Parameters //= (suit-parameter-uri => tstr)
SUIT_Parameters //= (suit-parameter-source-component => uint)
SUIT_Parameters //= (suit-parameter-run-args => bstr)

SUIT_Parameters //= (suit-parameter-device-identifier => RFC4122_UUID)
SUIT_Parameters //= (suit-parameter-minimum-battery => uint)
SUIT_Parameters //= (suit-parameter-update-priority => uint)
SUIT_Parameters //= (suit-parameter-version =>
    SUIT_Parameter_Version_Match)
SUIT_Parameters //= (suit-parameter-wait-info =>
    bstr .cbor SUIT_Wait_Event)

SUIT_Parameters //= (suit-parameter-custom => int/bool/tstr/bstr)

SUIT_Parameters //= (suit-parameter-strict-order => bool)
SUIT_Parameters //= (suit-parameter-soft-failure => bool)

SUIT_Parameters //= (suit-parameter-uri-list =>
    bstr .cbor SUIT_URI_List)

RFC4122_UUID = bstr .size 16

SUIT_Parameter_Version_Match = [
    suit-condition-version-comparison-type:
        SUIT_Condition_Version_Comparison_Types,
    suit-condition-version-comparison-value:
        SUIT_Condition_Version_Comparison_Value
]
SUIT_Condition_Version_Comparison_Types /=
    suit-condition-version-comparison-greater
SUIT_Condition_Version_Comparison_Types /=
    suit-condition-version-comparison-greater-equal
SUIT_Condition_Version_Comparison_Types /=
    suit-condition-version-comparison-equal
SUIT_Condition_Version_Comparison_Types /=
    suit-condition-version-comparison-lesser-equal
SUIT_Condition_Version_Comparison_Types /=
    suit-condition-version-comparison-lesser

suit-condition-version-comparison-greater = 1
suit-condition-version-comparison-greater-equal = 2
suit-condition-version-comparison-equal = 3
suit-condition-version-comparison-lesser-equal = 4
suit-condition-version-comparison-lesser = 5

SUIT_Condition_Version_Comparison_Value = [+int]

SUIT_Encryption_Info = COSE_Encrypt_Tagged/COSE_Encrypt0_Tagged
SUIT_Compression_Info = {
    suit-compression-algorithm => SUIT_Compression_Algorithms,
    * $$SUIT_Compression_Info-extensions,
}

SUIT_Compression_Algorithms /= SUIT_Compression_Algorithm_zlib
SUIT_Compression_Algorithms /= SUIT_Compression_Algorithm_brotli
SUIT_Compression_Algorithms /= SUIT_Compression_Algorithm_zstd

SUIT_Compression_Algorithm_zlib = 1
SUIT_Compression_Algorithm_brotli = 2
SUIT_Compression_Algorithm_zstd = 3

SUIT_Unpack_Info = {
    suit-unpack-algorithm => SUIT_Unpack_Algorithms,
    * $$SUIT_Unpack_Info-extensions,

}
SUIT_Unpack_Algorithms /= SUIT_Unpack_Algorithm_Hex
SUIT_Unpack_Algorithms /= SUIT_Unpack_Algorithm_Elf
SUIT_Unpack_Algorithms /= SUIT_Unpack_Algorithm_Coff
SUIT_Unpack_Algorithms /= SUIT_Unpack_Algorithm_Srec

SUIT_Unpack_Algorithm_Hex = 1
SUIT_Unpack_Algorithm_Elf = 2
SUIT_Unpack_Algorithm_Coff = 3
SUIT_Unpack_Algorithm_Srec = 4

SUIT_URI_List = [+ tstr ]

SUIT_Text_Map = {
    SUIT_Text_Keys,
    * SUIT_Component_Identifier => {
        SUIT_Text_Component_Keys
    },
    SUIT_Text_Keys
    }
}

SUIT_Text_Component_Keys = (
    ? suit-text-vendor-name           => tstr,
    ? suit-text-model-name            => tstr,
    ? suit-text-vendor-domain         => tstr,
    ? suit-text-model-info            => tstr,
    ? suit-text-component-description => tstr,
    ? suit-text-component-version     => tstr,
    ? suit-text-version-required      => tstr,
    * $$suit-text-component-key-extensions
)

SUIT_Text_Keys = (
    ? suit-text-manifest-description => tstr,
    ? suit-text-update-description   => tstr,
    ? suit-text-manifest-json-source => tstr,
    ? suit-text-manifest-yaml-source => tstr,
    * $$suit-text-key-extensions
)

suit-delegation = 1
suit-authentication-wrapper = 2
suit-manifest = 3

algorithm-id-sha224 = 1
algorithm-id-sha256 = 2
algorithm-id-sha384 = 3
algorithm-id-sha512

;REQUIRED to implement:
cose-alg-sha-256 = 4
algorithm-id-sha3-224 -16

;OPTIONAL to implement:
cose-alg-shake128 = 5
algorithm-id-sha3-256 -18
cose-alg-sha-384 = 6
algorithm-id-sha3-384 -43
cose-alg-sha-512 = 7
algorithm-id-sha3-512 -44
cose-alg-shake256 = 8 -45

suit-manifest-version = 1
suit-manifest-sequence-number = 2
suit-common = 3
suit-reference-uri = 4
suit-dependency-resolution = 7
suit-payload-fetch = 8
suit-install = 9
suit-validate = 10
suit-load = 11
suit-run = 12
suit-text = 13
suit-coswid = 14

suit-dependencies = 1
suit-components = 2
suit-common-sequence = 4

suit-dependency-digest = 1
suit-dependency-prefix = 2

suit-command-custom = nint

suit-condition-vendor-identifier = 1
suit-condition-class-identifier  = 2
suit-condition-image-match       = 3
suit-condition-use-before        = 4
suit-condition-component-offset
suit-condition-component-slot    = 5

suit-condition-abort                    = 14
suit-condition-device-identifier        = 24
suit-condition-image-not-match          = 25
suit-condition-minimum-battery          = 26
suit-condition-update-authorized        = 27
suit-condition-version                  = 28

suit-directive-set-component-index      = 12
suit-directive-set-dependency-index     = 13
suit-directive-try-each                 = 15
suit-directive-process-dependency       = 18
suit-directive-set-parameters           = 19
suit-directive-override-parameters      = 20
suit-directive-fetch                    = 21
suit-directive-copy                     = 22
suit-directive-run                      = 23
suit-directive-wait                     = 29
suit-directive-fetch-uri-list           = 30
suit-directive-swap                     = 31
suit-directive-run-sequence             = 32
suit-directive-garbage-collect
suit-directive-unlink                   = 33

suit-wait-event-authorization        = 1
suit-wait-event-power                = 2
suit-wait-event-network              = 3
suit-wait-event-other-device-version = 4
suit-wait-event-time                 = 5
suit-wait-event-time-of-day          = 6
suit-wait-event-day-of-week          = 7

suit-parameter-vendor-identifier = 1
suit-parameter-class-identifier  = 2
suit-parameter-image-digest      = 3
suit-parameter-use-before        = 4
suit-parameter-component-offset
suit-parameter-component-slot    = 5

suit-parameter-strict-order      = 12
suit-parameter-soft-failure      = 13
suit-parameter-image-size        = 14

suit-parameter-encryption-info   = 18
suit-parameter-compression-info  = 19
suit-parameter-unpack-info       = 20
suit-parameter-uri               = 21
suit-parameter-source-component  = 22
suit-parameter-run-args          = 23

suit-parameter-device-identifier = 24
suit-parameter-minimum-battery   = 26
suit-parameter-update-priority   = 27
suit-parameter-version           = 28
suit-parameter-wait-info         = 29
suit-parameter-uri-list          = 30

suit-parameter-custom = nint

suit-compression-algorithm = 1

suit-unpack-algorithm  = 1

suit-text-manifest-description  = 1
suit-text-update-description    = 2
suit-text-manifest-json-source  = 3
suit-text-manifest-yaml-source  = 4
suit-text-vendor-name           = 1
suit-text-model-name            = 2
suit-text-vendor-domain         = 3
suit-text-model-info            = 4
suit-text-component-description = 5
suit-text-component-version     = 6
suit-text-version-required      = 7

Appendix B.  B.  Examples

   The following examples demonstrate a small subset of the
   functionality of the manifest.  Even a simple manifest processor can
   execute most of these manifests.

   The examples are signed using the following ECDSA secp256r1 key:

   -----BEGIN PRIVATE KEY-----
   MIGHAgEAMBMGByqGSM49AgEGCCqGSM49AwEHBG0wawIBAQQgApZYjZCUGLM50VBC
   CjYStX+09jGmnyJPrpDLTz/hiXOhRANCAASEloEarguqq9JhVxie7NomvqqL8Rtv
   P+bitWWchdvArTsfKktsCYExwKNtrNHXi9OB3N+wnAUtszmR23M4tKiW
   -----END PRIVATE KEY-----

   The corresponding public key can be used to verify these examples:

   -----BEGIN PUBLIC KEY-----
   MFkwEwYHKoZIzj0CAQYIKoZIzj0DAQcDQgAEhJaBGq4LqqvSYVcYnuzaJr6qi/Eb
   bz/m4rVlnIXbwK07HypLbAmBMcCjbazR14vTgdzfsJwFLbM5kdtzOLSolg==
   -----END PUBLIC KEY-----

   Each example uses SHA256 as the digest function.

   Note that reporting policies are declared for each non-flow-control
   command in these examples.  The reporting policies used in the
   examples are described in the following tables.

                +-----------------------------+----------+
                | Policy                      | Label    |
                +-----------------------------+----------+
                | suit-send-record-on-success | Rec-Pass |
                |                             |          |
                | suit-send-record-on-failure | Rec-Fail |
                |                             |          |
                | suit-send-sysinfo-success   | Sys-Pass |
                |                             |          |
                | suit-send-sysinfo-failure   | Sys-Fail |
                +-----------------------------+----------+

   +----------------------------+--------+---------+---------+---------+
   | Command                    | Sys-   | Sys-    | Rec-    | Rec-    |
   |                            | Fail   | Pass    | Fail    | Pass    |
   +----------------------------+--------+---------+---------+---------+
   | suit-condition-vendor-     | 1      | 1       | 1       | 1       |
   | identifier                 |        |         |         |         |
   |                            |        |         |         |         |
   | suit-condition-class-      | 1      | 1       | 1       | 1       |
   | identifier                 |        |         |         |         |
   |                            |        |         |         |         |
   | suit-condition-image-match | 1      | 1       | 1       | 1       |
   |                            |        |         |         |         |
   | suit-condition-component-  | 0      | 1       | 0       | 1       |
   | offset slot                       |        |         |         |         |
   |                            |        |         |         |         |
   | suit-directive-fetch       | 0      | 0       | 1       | 0       |
   |                            |        |         |         |         |
   | suit-directive-copy        | 0      | 0       | 1       | 0       |
   |                            |        |         |         |         |
   | suit-directive-run         | 0      | 0       | 1       | 0       |
   +----------------------------+--------+---------+---------+---------+

B.1.  Example 0: Secure Boot

   This example covers the following templates:

   -  Compatibility Check (Section 7.1)

   -  Secure Boot (Section 7.2)

   It also serves as the minimum example.

  {

  107({
          / authentication-wrapper / 2:bstr .cbor ([ 2:<<[
              digest: bstr .cbor ([ <<[
                  / algorithm-id / 2 -16 / "sha256" /,
                  / digest-bytes /
  h'5c097ef64bf3bb9b494e71e1f2418eef8d466cc902f639a855ec9af3e9eddb99'
          ]),
  h'a6c4590ac53043a98e8c4106e1e31b305516d7cf0a655eddfac6d45c810e036a'
              ]>>,
              signature: bstr .cbor (18([ <<18([
                      / protected / bstr .cbor ({ <<{
                          / alg / 1:-7 / "ES256" /,
                  }),
                      }>>,
                      / unprotected / {
                      },
                      / payload / F6 / nil /,
                      / signature / h'a19fd1f23b17beed321cece7423dfb48c457b8
  f1f6ac83577a3c10c6773f6f3a7902376b59540920b6c5f57bac5fc8543d8f5d3d974f
  aa2e6d03daa534b443a7'
              ])) h'd11a2dd9610fb62a707335f58407922570
  9f96e8117e7eeed98a2f207d05c8ecfba1755208f6abea977b8a6efe3bc2ca3215e119
  3be201467d052b42db6b7287'
                  ])>>
              ]
      ]),
          ]>>,
          / manifest / 3:bstr .cbor ({ 3:<<{
              / manifest-version / 1:1,
              / manifest-sequence-number / 2:0,
              / common / 3:bstr .cbor ({ 3:<<{
                  / components / 2:[
                      [h'00']
                  ],
                  / common-sequence / 4:bstr .cbor ([ 4:<<[
                      / directive-override-parameters / 20,{
                          / vendor-id /
  1:h'fa6b4a53d5ad5fdfbe9de663e4d41ffe' / fa6b4a53-d5ad-5fdf-
  be9d-e663e4d41ffe /,
                          / class-id /
  2:h'1492af1425695e48bf429b2d51f2ab45' /
  1492af14-2569-5e48-bf42-9b2d51f2ab45 /,
                          / image-digest / 3:bstr .cbor ([ 3:<<[
                              / algorithm-id / 2 -16 / "sha256" /,
                              / digest-bytes /
  h'00112233445566778899aabbccddeeff0123456789abcdeffedcba9876543210'
                      ]),
                          ]>>,
                          / image-size / 14:34768,
                      } ,
                      / condition-vendor-identifier / 1,15 ,
                      / condition-class-identifier / 2,15
              ]),
          }),
                  ]>>,
              }>>,
              / validate / 10:bstr .cbor ([ 10:<<[
                  / condition-image-match / 3,15
          ]),
              ]>>,
              / run / 12:bstr .cbor ([ 12:<<[
                  / directive-run / 23,2
          ]),
      }),
  }
              ]>>,
          }>>,
      })

   Total size of Envelope without COSE authentication object: 159 161

   Envelope:

   a2025827815824820258205c097ef64bf3bb9b494e71e1f2418eef8d466c
   c902f639a855ec9af3e9eddb99035871a50101020003585fa20281814100
   0458568614a40150fa6b4a53d5ad5fdfbe9de663e4d41ffe02501492af14
   25695e48bf429b2d51f2ab450358248202582000112233445566778899aa
   bbccddeeff0123456789abcdeffedcba98765432100e1987d0010f020f0a
   4382030f0c43821702

   d86ba2025827815824822f5820a6c4590ac53043a98e8c4106e1e31b3055
   16d7cf0a655eddfac6d45c810e036a035871a50101020003585fa2028181
   41000458568614a40150fa6b4a53d5ad5fdfbe9de663e4d41ffe02501492
   af1425695e48bf429b2d51f2ab45035824822f5820001122334455667788
   99aabbccddeeff0123456789abcdeffedcba98765432100e1987d0010f02
   0f0a4382030f0c43821702

   Total size of Envelope with COSE authentication object: 235 237

   Envelope with COSE authentication object:

   a2025873825824820258205c097ef64bf3bb9b494e71e1f2418eef8d466c
   c902f639a855ec9af3e9eddb99584ad28443a10126a0f65840a19fd1f23b
   17beed321cece7423dfb48c457b8f1f6ac83577a3c10c6773f6f3a790237
   6b59540920b6c5f57bac5fc8543d8f5d3d974faa2e6d03daa534b443a703
   5871a50101020003585fa202818141000458568614a40150fa6b4a53d5ad
   5fdfbe9de663e4d41ffe02501492af1425695e48bf429b2d51f2ab450358
   248202582000112233445566778899aabbccddeeff0123456789abcdeffe
   dcba98765432100e1987d0010f020f0a4382030f0c43821702

   d86ba2025873825824822f5820a6c4590ac53043a98e8c4106e1e31b3055
   16d7cf0a655eddfac6d45c810e036a584ad28443a10126a0f65840d11a2d
   d9610fb62a707335f584079225709f96e8117e7eeed98a2f207d05c8ecfb
   a1755208f6abea977b8a6efe3bc2ca3215e1193be201467d052b42db6b72
   87035871a50101020003585fa202818141000458568614a40150fa6b4a53
   d5ad5fdfbe9de663e4d41ffe02501492af1425695e48bf429b2d51f2ab45
   035824822f582000112233445566778899aabbccddeeff0123456789abcd
   effedcba98765432100e1987d0010f020f0a4382030f0c43821702

B.2.  Example 1: Simultaneous Download and Installation of Payload

   This example covers the following templates:

   -  Compatibility Check (Section 7.1)

   -  Firmware Download (Section 7.3)

   Simultaneous download and installation of payload.  No secure boot is
   present in this example to demonstrate a download-only manifest.

  {

  107({
          / authentication-wrapper / 2:bstr .cbor ([ 2:<<[
              digest: bstr .cbor ([ <<[
                  / algorithm-id / 2 -16 / "sha256" /,
                  / digest-bytes /
  h'987eec85fa99fd31d332381b9810f90b05c2e0d4f284a6f4211207ed00fff750'
          ]),
  h'60c61d6eb7a1aaeddc49ce8157a55cff0821537eeee77a4ded44155b03045132'
              ]>>,
              signature: bstr .cbor (18([ <<18([
                      / protected / bstr .cbor ({ <<{
                          / alg / 1:-7 / "ES256" /,
                  }),
                      }>>,
                      / unprotected / {
                      },
                      / payload / F6 / nil /,
                      / signature / h'0008d2678ddda1afd6846cb9272f539a789e4c
  ed4c874774e58dbe4cf1607e755668029ad6383d4e14c72083ba43002fe3f5cda48859
  90c9b59135976b80ebc9'
              ])) h'5249dacaf0ffc8326931b09586eb7e3769
  e71a0e6a40ad8153db4980db9b05bd1742ddb46085fa11e62b65a79895c12ac7abe266
  8ccc5afdd74466aed7bca389'
                  ])>>
              ]
      ]),
          ]>>,
          / manifest / 3:bstr .cbor ({ 3:<<{
              / manifest-version / 1:1,
              / manifest-sequence-number / 2:1,
              / common / 3:bstr .cbor ({ 3:<<{
                  / components / 2:[
                      [h'00']
                  ],
                  / common-sequence / 4:bstr .cbor ([ 4:<<[
                      / directive-override-parameters / 20,{
                          / vendor-id /
  1:h'fa6b4a53d5ad5fdfbe9de663e4d41ffe' / fa6b4a53-d5ad-5fdf-
  be9d-e663e4d41ffe /,
                          / class-id /
  2:h'1492af1425695e48bf429b2d51f2ab45' /
  1492af14-2569-5e48-bf42-9b2d51f2ab45 /,
                          / image-digest / 3:bstr .cbor ([ 3:<<[
                              / algorithm-id / 2 -16 / "sha256" /,
                              / digest-bytes /
  h'00112233445566778899aabbccddeeff0123456789abcdeffedcba9876543210'
                      ]),
                          ]>>,
                          / image-size / 14:34768,
                      } ,
                      / condition-vendor-identifier / 1,15 ,
                      / condition-class-identifier / 2,15
              ]),
          }),
                  ]>>,
              }>>,
              / install / 9:bstr .cbor ([ 9:<<[
                  / directive-set-parameters / 19,{
                      / uri / 21:'http://example.com/file.bin',
                  } ,
                  / directive-fetch / 21,2 ,
                  / condition-image-match / 3,15
          ]),
              ]>>,
              / validate / 10:bstr .cbor ([ 10:<<[
                  / condition-image-match / 3,15
          ]),
      }),
  }
              ]>>,
          }>>,
      })

   Total size of Envelope without COSE authentication object: 194 196

   Envelope:

   a202582781582482025820987eec85fa99fd31d332381b9810f90b05c2e0
   d4f284a6f4211207ed00fff750035894a50101020103585fa20281814100
   0458568614a40150fa6b4a53d5ad5fdfbe9de663e4d41ffe02501492af14
   25695e48bf429b2d51f2ab450358248202582000112233445566778899aa
   bbccddeeff0123456789abcdeffedcba98765432100e1987d0010f020f09
   58258613a115781b687474703a2f2f6578616d706c652e636f6d2f66696c
   652e62696e1502030f0a4382030f

   d86ba2025827815824822f582060c61d6eb7a1aaeddc49ce8157a55cff08
   21537eeee77a4ded44155b03045132035894a50101020103585fa2028181
   41000458568614a40150fa6b4a53d5ad5fdfbe9de663e4d41ffe02501492
   af1425695e48bf429b2d51f2ab45035824822f5820001122334455667788
   99aabbccddeeff0123456789abcdeffedcba98765432100e1987d0010f02
   0f0958258613a115781b687474703a2f2f6578616d706c652e636f6d2f66
   696c652e62696e1502030f0a4382030f

   Total size of Envelope with COSE authentication object: 270 272

   Envelope with COSE authentication object:

   a202587382582482025820987eec85fa99fd31d332381b9810f90b05c2e0
   d4f284a6f4211207ed00fff750584ad28443a10126a0f658400008d2678d
   dda1afd6846cb9272f539a789e4ced4c874774e58dbe4cf1607e75566802
   9ad6383d4e14c72083ba43002fe3f5cda4885990c9b59135976b80ebc903
   5894a50101020103585fa202818141000458568614a40150fa6b4a53d5ad
   5fdfbe9de663e4d41ffe02501492af1425695e48bf429b2d51f2ab450358
   248202582000112233445566778899aabbccddeeff0123456789abcdeffe
   dcba98765432100e1987d0010f020f0958258613a115781b687474703a2f
   2f6578616d706c652e636f6d2f66696c652e62696e1502030f0a4382030f

   d86ba2025873825824822f582060c61d6eb7a1aaeddc49ce8157a55cff08
   21537eeee77a4ded44155b03045132584ad28443a10126a0f658405249da
   caf0ffc8326931b09586eb7e3769e71a0e6a40ad8153db4980db9b05bd17
   42ddb46085fa11e62b65a79895c12ac7abe2668ccc5afdd74466aed7bca3
   89035894a50101020103585fa202818141000458568614a40150fa6b4a53
   d5ad5fdfbe9de663e4d41ffe02501492af1425695e48bf429b2d51f2ab45
   035824822f582000112233445566778899aabbccddeeff0123456789abcd
   effedcba98765432100e1987d0010f020f0958258613a115781b68747470
   3a2f2f6578616d706c652e636f6d2f66696c652e62696e1502030f0a4382
   030f

B.3.  Example 2: Simultaneous Download, Installation, Secure Boot,
      Severed Fields

   This example covers the following templates:

   -  Compatibility Check (Section 7.1)

   -  Secure Boot (Section 7.2)

   -  Firmware Download (Section 7.3)

   This example also demonstrates severable elements (Section 5.5), and
   text (Section 8.6.4).

  {

  107({
          / authentication-wrapper / 2:bstr .cbor ([ 2:<<[
              digest: bstr .cbor ([ <<[
                  / algorithm-id / 2 -16 / "sha256" /,
                  / digest-bytes /
  h'78fa7652e377d31dcd7e95730c885ef13b6ee394d586410aa5fd0aca1f299d34'
          ]),
  h'e45dcdb2074b951f1c88b866469939c2a83ed433a31fc7dfcb3f63955bd943ec'
              ]>>,
              signature: bstr .cbor (18([ <<18([
                      / protected / bstr .cbor ({ <<{
                          / alg / 1:-7 / "ES256" /,
                  }),
                      }>>,
                      / unprotected / {
                      },
                      / payload / F6 / nil /,
                      / signature / h'1aa5bf99688b5d6a1211fd9c99bdd409b64cd6
  add316ff87029a81faf682f93c5fb94863eebdfd17a6fcfed729ffa9735a624ce7edb5
  65cba26ff7a5bd6a779d'
              ])) h'b4fd3a6a18fe1062573488cf24ac96ef9f
  30ac746696e50be96533b356b8156e4332587fe6f4e8743ae525d72005fddd4c1213d5
  5a8061b2ce67b83640f4777c'
                  ])>>
              ]
      ]),
          ]>>,
          / manifest / 3:bstr .cbor ({ 3:<<{
              / manifest-version / 1:1,
              / manifest-sequence-number / 2:2,
              / common / 3:bstr .cbor ({ 3:<<{
                  / components / 2:[
                      [h'00']
                  ],
                  / common-sequence / 4:bstr .cbor ([ 4:<<[
                      / directive-override-parameters / 20,{
                          / vendor-id /
  1:h'fa6b4a53d5ad5fdfbe9de663e4d41ffe' / fa6b4a53-d5ad-5fdf-
  be9d-e663e4d41ffe /,
                          / class-id /
  2:h'1492af1425695e48bf429b2d51f2ab45' /
  1492af14-2569-5e48-bf42-9b2d51f2ab45 /,
                          / image-digest / 3:bstr .cbor ([ 3:<<[
                              / algorithm-id / 2 -16 / "sha256" /,
                              / digest-bytes /
  h'00112233445566778899aabbccddeeff0123456789abcdeffedcba9876543210'
                      ]),
                          ]>>,
                          / image-size / 14:34768,
                      } ,
                      / condition-vendor-identifier / 1,15 ,
                      / condition-class-identifier / 2,15
              ]),
          }),
                  ]>>,
              }>>,
              / install / 9:[
                  / algorithm-id / 2 -16 / "sha256" /,
                  / digest-bytes /
  h'3ee96dc79641970ae46b929ccf0b72ba9536dd846020dbdc9f949d84ea0e18d2'
              ],
              / validate / 10:bstr .cbor ([ 10:<<[
                  / condition-image-match / 3,15
          ]),
              ]>>,
              / run / 12:bstr .cbor ([ 12:<<[
                  / directive-run / 23,2
          ]),
              ]>>,
              / text / 13:[
                  / algorithm-id / 2 -16 / "sha256" /,
                  / digest-bytes /
  h'2bfc4d0cc6680be7dd9f5ca30aa2bb5d1998145de33d54101b80e2ca49faf918'
              ],
      }),
          }>>,
          / install / 9:bstr .cbor ([ 9:<<[
              / directive-set-parameters / 19,{
                  / uri /
  21:'http://example.com/very/long/path/to/file/file.bin',
              } ,
              / directive-fetch / 21,2 ,
              / condition-image-match / 3,15
      ]),
          ]>>,
          / text / 13:bstr .cbor ({ 13:<<{
              [h'00']:{
                      / vendor-domain / 3:'arm.com',
                      / component-description / 5:'This component is a
  demonstration. The digest is a sample pattern, not a real one.',
                  }
      }),
  }
          }>>,
      })

   Total size of the Envelope without COSE authentication object or
   Severable Elements: 233 235

   Envelope:

   a20258278158248202582078fa7652e377d31dcd7e95730c885ef13b6ee3
   94d586410aa5fd0aca1f299d340358bba70101020203585fa20281814100
   0458568614a40150fa6b4a53d5ad5fdfbe9de663e4d41ffe02501492af14
   25695e48bf429b2d51f2ab450358248202582000112233445566778899aa
   bbccddeeff0123456789abcdeffedcba98765432100e1987d0010f020f09
   820258203ee96dc79641970ae46b929ccf0b72ba9536dd846020dbdc9f94
   9d84ea0e18d20a4382030f0c438217020d820258202bfc4d0cc6680be7dd
   9f5ca30aa2bb5d1998145de33d54101b80e2ca49faf918

   d86ba2025827815824822f5820e45dcdb2074b951f1c88b866469939c2a8
   3ed433a31fc7dfcb3f63955bd943ec0358bba70101020203585fa2028181
   41000458568614a40150fa6b4a53d5ad5fdfbe9de663e4d41ffe02501492
   af1425695e48bf429b2d51f2ab45035824822f5820001122334455667788
   99aabbccddeeff0123456789abcdeffedcba98765432100e1987d0010f02
   0f09822f58203ee96dc79641970ae46b929ccf0b72ba9536dd846020dbdc
   9f949d84ea0e18d20a4382030f0c438217020d822f58202bfc4d0cc6680b
   e7dd9f5ca30aa2bb5d1998145de33d54101b80e2ca49faf918

   Total size of the Envelope with COSE authentication object but
   without Severable Elements: 309 311

   Envelope:

   a20258738258248202582078fa7652e377d31dcd7e95730c885ef13b6ee3
   94d586410aa5fd0aca1f299d34584ad28443a10126a0f658401aa5bf9968
   8b5d6a1211fd9c99bdd409b64cd6add316ff87029a81faf682f93c5fb948
   63eebdfd17a6fcfed729ffa9735a624ce7edb565cba26ff7a5bd6a779d03
   58bba70101020203585fa202818141000458568614a40150fa6b4a53d5ad
   5fdfbe9de663e4d41ffe02501492af1425695e48bf429b2d51f2ab450358
   248202582000112233445566778899aabbccddeeff0123456789abcdeffe
   dcba98765432100e1987d0010f020f09820258203ee96dc79641970ae46b
   929ccf0b72ba9536dd846020dbdc9f949d84ea0e18d20a4382030f0c4382
   17020d820258202bfc4d0cc6680be7dd9f5ca30aa2bb5d1998145de33d54
   101b80e2ca49faf918

   d86ba2025873825824822f5820e45dcdb2074b951f1c88b866469939c2a8
   3ed433a31fc7dfcb3f63955bd943ec584ad28443a10126a0f65840b4fd3a
   6a18fe1062573488cf24ac96ef9f30ac746696e50be96533b356b8156e43
   32587fe6f4e8743ae525d72005fddd4c1213d55a8061b2ce67b83640f477
   7c0358bba70101020203585fa202818141000458568614a40150fa6b4a53
   d5ad5fdfbe9de663e4d41ffe02501492af1425695e48bf429b2d51f2ab45
   035824822f582000112233445566778899aabbccddeeff0123456789abcd
   effedcba98765432100e1987d0010f020f09822f58203ee96dc79641970a
   e46b929ccf0b72ba9536dd846020dbdc9f949d84ea0e18d20a4382030f0c
   438217020d822f58202bfc4d0cc6680be7dd9f5ca30aa2bb5d1998145de3
   3d54101b80e2ca49faf918

   Total size of Envelope with COSE authentication object and Severable
   Elements: 892 894

   Envelope with COSE authentication object:

   a40258738258248202582078fa7652e377d31dcd7e95730c885ef13b6ee3
   94d586410aa5fd0aca1f299d34584ad28443a10126a0f658401aa5bf9968
   8b5d6a1211fd9c99bdd409b64cd6add316ff87029a81faf682f93c5fb948
   63eebdfd17a6fcfed729ffa9735a624ce7edb565cba26ff7a5bd6a779d03
   58bba70101020203585fa202818141000458568614a40150fa6b4a53d5ad
   5fdfbe9de663e4d41ffe02501492af1425695e48bf429b2d51f2ab450358
   248202582000112233445566778899aabbccddeeff0123456789abcdeffe
   dcba98765432100e1987d0010f020f09820258203ee96dc79641970ae46b
   929ccf0b72ba9536dd846020dbdc9f949d84ea0e18d20a4382030f0c4382
   17020d820258202bfc4d0cc6680be7dd9f5ca30aa2bb5d1998145de33d54
   101b80e2ca49faf91809583c8613a1157832687474703a2f2f6578616d70
   6c652e636f6d2f766572792f6c6f6e672f706174682f746f2f66696c652f
   66696c652e62696e1502030f0d590204a20179019d2323204578616d706c
   6520323a2053696d756c74616e656f757320446f776e6c6f61642c20496e
   7374616c6c6174696f6e2c2053656375726520426f6f742c205365766572
   6564204669656c64730a0a2020202054686973206578616d706c6520636f
   766572732074686520666f6c6c6f77696e672074656d706c617465733a0a
   202020200a202020202a20436f6d7061746962696c69747920436865636b
   20287b7b74656d706c6174652d636f6d7061746962696c6974792d636865
   636b7d7d290a202020202a2053656375726520426f6f7420287b7b74656d
   706c6174652d7365637572652d626f6f747d7d290a202020202a20466972
   6d7761726520446f776e6c6f616420287b7b6669726d776172652d646f77
   6e6c6f61642d74656d706c6174657d7d290a202020200a20202020546869
   73206578616d706c6520616c736f2064656d6f6e73747261746573207365
   76657261626c6520656c656d656e747320287b7b6f76722d736576657261
   626c657d7d292c20616e64207465787420287b7b6d616e69666573742d64
   69676573742d746578747d7d292e814100a2036761726d2e636f6d057852
   5468697320636f6d706f6e656e7420697320612064656d6f6e7374726174
   696f6e2e205468652064696765737420697320612073616d706c65207061
   747465726e2c206e6f742061207265616c206f6e652e

   d86ba4025873825824822f5820e45dcdb2074b951f1c88b866469939c2a8
   3ed433a31fc7dfcb3f63955bd943ec584ad28443a10126a0f65840b4fd3a
   6a18fe1062573488cf24ac96ef9f30ac746696e50be96533b356b8156e43
   32587fe6f4e8743ae525d72005fddd4c1213d55a8061b2ce67b83640f477
   7c0358bba70101020203585fa202818141000458568614a40150fa6b4a53
   d5ad5fdfbe9de663e4d41ffe02501492af1425695e48bf429b2d51f2ab45
   035824822f582000112233445566778899aabbccddeeff0123456789abcd
   effedcba98765432100e1987d0010f020f09822f58203ee96dc79641970a
   e46b929ccf0b72ba9536dd846020dbdc9f949d84ea0e18d20a4382030f0c
   438217020d822f58202bfc4d0cc6680be7dd9f5ca30aa2bb5d1998145de3
   3d54101b80e2ca49faf91809583c8613a1157832687474703a2f2f657861
   6d706c652e636f6d2f766572792f6c6f6e672f706174682f746f2f66696c
   652f66696c652e62696e1502030f0d590204a20179019d2323204578616d
   706c6520323a2053696d756c74616e656f757320446f776e6c6f61642c20
   496e7374616c6c6174696f6e2c2053656375726520426f6f742c20536576
   65726564204669656c64730a0a2020202054686973206578616d706c6520
   636f766572732074686520666f6c6c6f77696e672074656d706c61746573
   3a0a202020200a202020202a20436f6d7061746962696c69747920436865
   636b20287b7b74656d706c6174652d636f6d7061746962696c6974792d63
   6865636b7d7d290a202020202a2053656375726520426f6f7420287b7b74
   656d706c6174652d7365637572652d626f6f747d7d290a202020202a2046
   69726d7761726520446f776e6c6f616420287b7b6669726d776172652d64
   6f776e6c6f61642d74656d706c6174657d7d290a202020200a2020202054
   686973206578616d706c6520616c736f2064656d6f6e7374726174657320
   736576657261626c6520656c656d656e747320287b7b6f76722d73657665
   7261626c657d7d292c20616e64207465787420287b7b6d616e6966657374
   2d6469676573742d746578747d7d292e814100a2036761726d2e636f6d05
   78525468697320636f6d706f6e656e7420697320612064656d6f6e737472
   6174696f6e2e205468652064696765737420697320612073616d706c6520
   7061747465726e2c206e6f742061207265616c206f6e652e

B.4.  Example 3: A/B images

   This example covers the following templates:

   -  Compatibility Check (Section 7.1)

   -  Secure Boot (Section 7.2)

   -  Firmware Download (Section 7.3)

   -  A/B Image Template (Section 7.11)

  {

  107({
          / authentication-wrapper / 2:bstr .cbor ([ 2:<<[
              digest: bstr .cbor ([ <<[
                  / algorithm-id / 2 -16 / "sha256" /,
                  / digest-bytes /

  h'ae0c1ea689c9800a843550f38796b6fdbd52a0c78be5d26011d8e784da43d47c'
          ]),
  h'7c9b3cb72c262608a42f944d59d659ff2b801c78af44def51b8ff51e9f45721b'
              ]>>,
              signature: bstr .cbor (18([ <<18([
                      / protected / bstr .cbor ({ <<{
                          / alg / 1:-7 / "ES256" /,
                  }),
                      }>>,
                      / unprotected / {
                      },
                      / payload / F6 / nil /,
                      / signature / h'1296c87d168bb857495e6551730f9d6d3a6d81
  ad6c908c72fbc52ddcb2e8011d20d217b3f1c028374eecbda5d2ca26d047270b397dca
  a91a48a7c78cf376004e'
              ])) h'e33d618df0ad21e609529ab1a876afb231
  faff1d6a3189b5360324c2794250b87cf00cf83be50ea17dc721ca85393cd8e839a066
  d5dec0ad87a903ab31ea9afa'
                  ])>>
              ]
      ]),
          ]>>,
          / manifest / 3:bstr .cbor ({ 3:<<{
              / manifest-version / 1:1,
              / manifest-sequence-number / 2:3,
              / common / 3:bstr .cbor ({ 3:<<{
                  / components / 2:[
                      [h'00']
                  ],
                  / common-sequence / 4:bstr .cbor ([ 4:<<[
                      / directive-override-parameters / 20,{
                          / vendor-id /
  1:h'fa6b4a53d5ad5fdfbe9de663e4d41ffe' / fa6b4a53-d5ad-5fdf-
  be9d-e663e4d41ffe /,
                          / class-id /
  2:h'1492af1425695e48bf429b2d51f2ab45' /
  1492af14-2569-5e48-bf42-9b2d51f2ab45 /,
                      } ,
                      / directive-try-each / 15,[
                      bstr .cbor ([
                          <<[
                              / directive-override-parameters / 20,{
                                  / offset / 5:33792,
                              } ,
                              / condition-component-offset / 5,5 ,
                              / directive-override-parameters / 20,{
                                  / image-digest / 3:bstr .cbor ([ 3:<<[
                                      / algorithm-id / 2 -16 / "sha256" /,
                                      / digest-bytes /
  h'00112233445566778899aabbccddeeff0123456789abcdeffedcba9876543210'
                              ]),
                                  ]>>,
                                  / image-size / 14:34768,
                              }
                      ])
                          ]>> ,
                      bstr .cbor ([
                          <<[
                              / directive-override-parameters / 20,{
                                  / offset / 5:541696,
                              } ,
                              / condition-component-offset / 5,5 ,
                              / directive-override-parameters / 20,{
                                  / image-digest / 3:bstr .cbor ([ 3:<<[
                                      / algorithm-id / 2 -16 / "sha256" /,
                                      / digest-bytes /
  h'0123456789abcdeffedcba987654321000112233445566778899aabbccddeeff'
                              ]),
                                  ]>>,
                                  / image-size / 14:76834,
                              }
                      ])
                          ]>>
                      ] ,
                      / condition-vendor-identifier / 1,15 ,
                      / condition-class-identifier / 2,15
              ]),
          }),
                  ]>>,
              }>>,
              / install / 9:bstr .cbor ([ 9:<<[
                  / directive-try-each / 15,[
                  bstr .cbor ([
                      <<[
                          / directive-set-parameters / 19,{
                              / offset / 5:33792,
                          } ,
                          / condition-component-offset / 5,5 ,
                          / directive-set-parameters / 19,{
                              / uri / 21:'http://example.com/file1.bin',
                          }
                  ])
                      ]>> ,
                  bstr .cbor ([
                      <<[
                          / directive-set-parameters / 19,{
                              / offset / 5:541696,

                          } ,
                          / condition-component-offset / 5,5 ,
                          / directive-set-parameters / 19,{
                              / uri / 21:'http://example.com/file2.bin',
                          }
                  ])
                      ]>>
                  ] ,
                  / directive-fetch / 21,2 ,
                  / condition-image-match / 3,15
          ]),
              ]>>,
              / validate / 10:bstr .cbor ([ 10:<<[
                  / condition-image-match / 3,15
          ]),
      }),
  }
              ]>>,
          }>>,
      })

   Total size of Envelope without COSE authentication object: 330 332

   Envelope:

   a202582781582482025820ae0c1ea689c9800a843550f38796b6fdbd52a0
   c78be5d26011d8e784da43d47c0359011ba5010102030358aaa202818141
   000458a18814a20150fa6b4a53d5ad5fdfbe9de663e4d41ffe02501492af
   1425695e48bf429b2d51f2ab450f8258368614a105198400050514a20358
   248202582000112233445566778899aabbccddeeff0123456789abcdeffe
   dcba98765432100e1987d0583a8614a1051a00084400050514a203582482
   0258200123456789abcdeffedcba987654321000112233445566778899aa
   bbccddeeff0e1a00012c22010f020f095861860f82582a8613a105198400
   050513a115781c687474703a2f2f6578616d706c652e636f6d2f66696c65
   312e62696e582c8613a1051a00084400050513a115781c687474703a2f2f
   6578616d706c652e636f6d2f66696c65322e62696e1502030f0a4382030f

   d86ba2025827815824822f58207c9b3cb72c262608a42f944d59d659ff2b
   801c78af44def51b8ff51e9f45721b0359011ba5010102030358aaa20281
   8141000458a18814a20150fa6b4a53d5ad5fdfbe9de663e4d41ffe025014
   92af1425695e48bf429b2d51f2ab450f8258368614a105198400050514a2
   035824822f582000112233445566778899aabbccddeeff0123456789abcd
   effedcba98765432100e1987d0583a8614a1051a00084400050514a20358
   24822f58200123456789abcdeffedcba9876543210001122334455667788
   99aabbccddeeff0e1a00012c22010f020f095861860f82582a8613a10519
   8400050513a115781c687474703a2f2f6578616d706c652e636f6d2f6669
   6c65312e62696e582c8613a1051a00084400050513a115781c687474703a
   2f2f6578616d706c652e636f6d2f66696c65322e62696e1502030f0a4382
   030f

   Total size of Envelope with COSE authentication object: 406 408

   Envelope with COSE authentication object:

   a202587382582482025820ae0c1ea689c9800a843550f38796b6fdbd52a0
   c78be5d26011d8e784da43d47c584ad28443a10126a0f658401296c87d16
   8bb857495e6551730f9d6d3a6d81ad6c908c72fbc52ddcb2e8011d20d217
   b3f1c028374eecbda5d2ca26d047270b397dcaa91a48a7c78cf376004e03
   59011ba5010102030358aaa202818141000458a18814a20150fa6b4a53d5
   ad5fdfbe9de663e4d41ffe02501492af1425695e48bf429b2d51f2ab450f
   8258368614a105198400050514a203582482025820001122334455667788
   99aabbccddeeff0123456789abcdeffedcba98765432100e1987d0583a86
   14a1051a00084400050514a2035824820258200123456789abcdeffedcba
   987654321000112233445566778899aabbccddeeff0e1a00012c22010f02
   0f095861860f82582a8613a105198400050513a115781c687474703a2f2f
   6578616d706c652e636f6d2f66696c65312e62696e582c8613a1051a0008
   4400050513a115781c687474703a2f2f6578616d706c652e636f6d2f6669
   6c65322e62696e1502030f0a4382030f

   d86ba2025873825824822f58207c9b3cb72c262608a42f944d59d659ff2b
   801c78af44def51b8ff51e9f45721b584ad28443a10126a0f65840e33d61
   8df0ad21e609529ab1a876afb231faff1d6a3189b5360324c2794250b87c
   f00cf83be50ea17dc721ca85393cd8e839a066d5dec0ad87a903ab31ea9a
   fa0359011ba5010102030358aaa202818141000458a18814a20150fa6b4a
   53d5ad5fdfbe9de663e4d41ffe02501492af1425695e48bf429b2d51f2ab
   450f8258368614a105198400050514a2035824822f582000112233445566
   778899aabbccddeeff0123456789abcdeffedcba98765432100e1987d058
   3a8614a1051a00084400050514a2035824822f58200123456789abcdeffe
   dcba987654321000112233445566778899aabbccddeeff0e1a00012c2201
   0f020f095861860f82582a8613a105198400050513a115781c687474703a
   2f2f6578616d706c652e636f6d2f66696c65312e62696e582c8613a1051a
   00084400050513a115781c687474703a2f2f6578616d706c652e636f6d2f
   66696c65322e62696e1502030f0a4382030f

B.5.  Example 4: Load and Decompress from External Storage

   This example covers the following templates:

   -  Compatibility Check (Section 7.1)

   -  Secure Boot (Section 7.2)

   -  Firmware Download (Section 7.3)

   -  Install (Section 7.4)

   -  Load & Decompress (Section 7.8)

  {

  107({
          / authentication-wrapper / 2:bstr .cbor ([ 2:<<[
              digest: bstr .cbor ([ <<[
                  / algorithm-id / 2 -16 / "sha256" /,
                  / digest-bytes /
  h'4b4c7c8c0fda76c9c9591a9db160918e2b3c96a58b0a5e4984fd4e8f9359a928'
          ]),
  h'15736702a00f510805dcf89d6913a2cfb417ed414faa760f974d6755c68ba70a'
              ]>>,
              signature: bstr .cbor (18([ <<18([
                      / protected / bstr .cbor ({ <<{
                          / alg / 1:-7 / "ES256" /,
                  }),
                      }>>,
                      / unprotected / {
                      },
                      / payload / F6 / nil /,
                      / signature / h'd88c4953fe5a0399e69ab37fe654d1f1b957a4
  4a46fde3e9cffdf0cdaa0456ddce9f08bc2a59895ffd70adce0e4aee8690645dcd4b7b
  77d401bd91e35aa115d2'
              ])) h'3ada2532326d512132c388677798c24ffd
  cc979bfae2a26b19c8c8bbf511fd7dd85f1501662c1a9e1976b759c4019bab44ba5434
  efb45d3868aedbca593671f3'
                  ])>>
              ]
      ]),

          ]>>,
          / manifest / 3:bstr .cbor ({ 3:<<{
              / manifest-version / 1:1,
              / manifest-sequence-number / 2:4,
              / common / 3:bstr .cbor ({ 3:<<{
                  / components / 2:[
                      [h'00'] ,
                      [h'02'] ,
                      [h'01']
                  ],
                  / common-sequence / 4:bstr .cbor ([ 4:<<[
                      / directive-set-component-index / 12,0 ,
                      / directive-override-parameters / 20,{
                          / vendor-id /
  1:h'fa6b4a53d5ad5fdfbe9de663e4d41ffe' / fa6b4a53-d5ad-5fdf-
  be9d-e663e4d41ffe /,
                          / class-id /
  2:h'1492af1425695e48bf429b2d51f2ab45' /
  1492af14-2569-5e48-bf42-9b2d51f2ab45 /,
                          / image-digest / 3:bstr .cbor ([ 3:<<[
                              / algorithm-id / 2 -16 / "sha256" /,
                              / digest-bytes /
  h'00112233445566778899aabbccddeeff0123456789abcdeffedcba9876543210'
                      ]),
                          ]>>,
                          / image-size / 14:34768,
                      } ,
                      / condition-vendor-identifier / 1,15 ,
                      / condition-class-identifier / 2,15
              ]),
          }),
                  ]>>,
              }>>,
              / payload-fetch / 8:bstr .cbor ([ 8:<<[
                  / directive-set-component-index / 12,1 ,
                  / directive-set-parameters / 19,{
                      / uri / 21:'http://example.com/file.bin',
                  } ,
                  / directive-fetch / 21,2 ,
                  / condition-image-match / 3,15
          ]),
              ]>>,
              / install / 9:bstr .cbor ([ 9:<<[
                  / directive-set-component-index / 12,0 ,
                  / directive-set-parameters / 19,{
                      / source-component / 22:1 / [h'02'] /,
                  } ,
                  / directive-copy / 22,2 ,
                  / condition-image-match / 3,15
          ]),
              ]>>,
              / validate / 10:bstr .cbor ([ 10:<<[
                  / directive-set-component-index / 12,0 ,
                  / condition-image-match / 3,15
          ]),
              ]>>,
              / load / 11:bstr .cbor ([ 11:<<[
                  / directive-set-component-index / 12,2 ,
                  / directive-set-parameters / 19,{
                      / image-digest / 3:bstr .cbor ([ 3:<<[
                          / algorithm-id / 2 -16 / "sha256" /,
                          / digest-bytes /
  h'0123456789abcdeffedcba987654321000112233445566778899aabbccddeeff'
                  ]),
                      ]>>,
                      / image-size / 14:76834,
                      / source-component / 22:0 / [h'00'] /,
                      / compression-info / 19:1 19:<<{
                          / compression-algorithm / 1:1 / "gzip" /,
                      }>>,
                  } ,
                  / directive-copy / 22,2 ,
                  / condition-image-match / 3,15
          ]),
              ]>>,
              / run / 12:bstr .cbor ([ 12:<<[
                  / directive-set-component-index / 12,2 ,
                  / directive-run / 23,2
          ]),
      }),
  }
              ]>>,
          }>>,
      })

   Total size of Envelope without COSE authentication object: 287 292

   Envelope:

   a2025827815824820258204b4c7c8c0fda76c9c9591a9db160918e2b3c96
   a58b0a5e4984fd4e8f9359a9280358f1a801010204035867a20283814100
   814102814101045858880c0014a40150fa6b4a53d5ad5fdfbe9de663e4d4
   1ffe02501492af1425695e48bf429b2d51f2ab4503582482025820001122
   33445566778899aabbccddeeff0123456789abcdeffedcba98765432100e
   1987d0010f020f085827880c0113a115781b687474703a2f2f6578616d70
   6c652e636f6d2f66696c652e62696e1502030f094b880c0013a116011602
   030f0a45840c00030f0b583a880c0213a4035824820258200123456789ab
   cdeffedcba987654321000112233445566778899aabbccddeeff0e1a0001
   2c22130116001602030f0c45840c021702

   d86ba2025827815824822f582015736702a00f510805dcf89d6913a2cfb4
   17ed414faa760f974d6755c68ba70a0358f4a801010204035867a2028381
   4100814102814101045858880c0014a40150fa6b4a53d5ad5fdfbe9de663
   e4d41ffe02501492af1425695e48bf429b2d51f2ab45035824822f582000
   112233445566778899aabbccddeeff0123456789abcdeffedcba98765432
   100e1987d0010f020f085827880c0113a115781b687474703a2f2f657861
   6d706c652e636f6d2f66696c652e62696e1502030f094b880c0013a11601
   1602030f0a45840c00030f0b583d880c0213a4035824822f582001234567
   89abcdeffedcba987654321000112233445566778899aabbccddeeff0e1a
   00012c221343a1010116001602030f0c45840c021702

   Total size of Envelope with COSE authentication object: 363 368

   Envelope with COSE authentication object:

   a2025873825824820258204b4c7c8c0fda76c9c9591a9db160918e2b3c96
   a58b0a5e4984fd4e8f9359a928584ad28443a10126a0f65840d88c4953fe
   5a0399e69ab37fe654d1f1b957a44a46fde3e9cffdf0cdaa0456ddce9f08
   bc2a59895ffd70adce0e4aee8690645dcd4b7b77d401bd91e35aa115d203
   58f1a801010204035867a20283814100814102814101045858880c0014a4
   0150fa6b4a53d5ad5fdfbe9de663e4d41ffe02501492af1425695e48bf42
   9b2d51f2ab450358248202582000112233445566778899aabbccddeeff01
   23456789abcdeffedcba98765432100e1987d0010f020f085827880c0113
   a115781b687474703a2f2f6578616d706c652e636f6d2f66696c652e6269
   6e1502030f094b880c0013a116011602030f0a45840c00030f0b583a880c
   0213a4035824820258200123456789abcdeffedcba987654321000112233
   445566778899aabbccddeeff0e1a00012c22130116001602030f0c45840c
   021702

   d86ba2025873825824822f582015736702a00f510805dcf89d6913a2cfb4
   17ed414faa760f974d6755c68ba70a584ad28443a10126a0f658403ada25
   32326d512132c388677798c24ffdcc979bfae2a26b19c8c8bbf511fd7dd8
   5f1501662c1a9e1976b759c4019bab44ba5434efb45d3868aedbca593671
   f30358f4a801010204035867a20283814100814102814101045858880c00
   14a40150fa6b4a53d5ad5fdfbe9de663e4d41ffe02501492af1425695e48
   bf429b2d51f2ab45035824822f582000112233445566778899aabbccddee
   ff0123456789abcdeffedcba98765432100e1987d0010f020f085827880c
   0113a115781b687474703a2f2f6578616d706c652e636f6d2f66696c652e
   62696e1502030f094b880c0013a116011602030f0a45840c00030f0b583d
   880c0213a4035824822f58200123456789abcdeffedcba98765432100011
   2233445566778899aabbccddeeff0e1a00012c221343a101011600160203
   0f0c45840c021702

B.6.  Example 5: Two Images

   This example covers the following templates:

   -  Compatibility Check (Section 7.1)

   -  Secure Boot (Section 7.2)

   -  Firmware Download (Section 7.3)

   Furthermore, it shows using these templates with two images.

  {

  107({
          / authentication-wrapper / 2:bstr .cbor ([ 2:<<[
              digest: bstr .cbor ([ <<[
                  / algorithm-id / 2 -16 / "sha256" /,
                  / digest-bytes /
  h'de7c7927a15bd2eda59cab1512875f17c9f1e9e23885ce1ac6d671eefcefa37a'
          ]),
  h'd1e73f16e4126007bc4d804cd33b0209fbab34728e60ee8c00f3387126748dd2'
              ]>>,
              signature: bstr .cbor (18([ <<18([
                      / protected / bstr .cbor ({ <<{
                          / alg / 1:-7 / "ES256" /,
                  }),
                      }>>,
                      / unprotected / {
                      },
                      / payload / F6 / nil /,
                      / signature / h'8f5919c05ef786366ab4899db27a2e7412ef72
  480372437757b1c1c9f8b2ed2a677a88db17fcfbb47d178c9e5620f14ac68a314ceabc
  d20cbf54fbe89b8e83ad'
              ])) h'b7ae0a46a28f02e25cda6d9a255bbaf863
  30141831fae5a78012d648bc6cee55102e0f1890bdeacc3adaa4fae0560f83a45eecae
  65cabce642f56d84ab97ef8d'
                  ])>>
              ]
      ]),
          ]>>,
          / manifest / 3:bstr .cbor ({ 3:<<{
              / manifest-version / 1:1,
              / manifest-sequence-number / 2:5,
              / common / 3:bstr .cbor ({ 3:<<{
                  / components / 2:[
                      [h'00'] ,
                      [h'01']
                  ],
                  / common-sequence / 4:bstr .cbor ([ 4:<<[
                      / directive-set-component-index / 12,0 ,
                      / directive-override-parameters / 20,{
                          / vendor-id /
  1:h'fa6b4a53d5ad5fdfbe9de663e4d41ffe' / fa6b4a53-d5ad-5fdf-
  be9d-e663e4d41ffe /,
                          / class-id /
  2:h'1492af1425695e48bf429b2d51f2ab45' /
  1492af14-2569-5e48-bf42-9b2d51f2ab45 /,
                          / image-digest / 3:bstr .cbor ([ 3:<<[
                              / algorithm-id / 2 -16 / "sha256" /,
                              / digest-bytes /
  h'00112233445566778899aabbccddeeff0123456789abcdeffedcba9876543210'
                      ]),
                          ]>>,
                          / image-size / 14:34768,
                      } ,
                      / condition-vendor-identifier / 1,15 ,
                      / condition-class-identifier / 2,15 ,
                      / directive-set-component-index / 12,1 ,
                      / directive-override-parameters / 20,{
                          / image-digest / 3:bstr .cbor ([ 3:<<[
                              / algorithm-id / 2 -16 / "sha256" /,
                              / digest-bytes /
  h'0123456789abcdeffedcba987654321000112233445566778899aabbccddeeff'
                      ]),
                          ]>>,
                          / image-size / 14:76834,
                      }
              ]),

          }),
                  ]>>,
              }>>,
              / install / 9:bstr .cbor ([ 9:<<[
                  / directive-set-component-index / 12,0 ,
                  / directive-set-parameters / 19,{
                      / uri / 21:'http://example.com/file1.bin',
                  } ,
                  / directive-fetch / 21,2 ,
                  / condition-image-match / 3,15 ,
                  / directive-set-component-index / 12,1 ,
                  / directive-set-parameters / 19,{
                      / uri / 21:'http://example.com/file2.bin',
                  } ,
                  / directive-fetch / 21,2 ,
                  / condition-image-match / 3,15
          ]),

              ]>>,
              / validate / 10:bstr .cbor ([ 10:<<[
                  / directive-set-component-index / 12,0 ,
                  / condition-image-match / 3,15 ,
                  / directive-set-component-index / 12,1 ,
                  / condition-image-match / 3,15
          ]),
              ]>>,
              / run / 12:bstr .cbor ([ 12:<<[
                  / directive-set-component-index / 12,0 ,
                  / directive-run / 23,2
          ]),
      }),
  }
              ]>>,
          }>>,
      })

   Total size of Envelope without COSE authentication object: 304 306

   Envelope:

   a202582781582482025820de7c7927a15bd2eda59cab1512875f17c9f1e9
   e23885ce1ac6d671eefcefa37a03590101a601010205035895a202828141
   008141010458898c0c0014a40150fa6b4a53d5ad5fdfbe9de663e4d41ffe
   02501492af1425695e48bf429b2d51f2ab45035824820258200011223344
   5566778899aabbccddeeff0123456789abcdeffedcba98765432100e1987
   d0010f020f0c0114a2035824820258200123456789abcdeffedcba987654
   321000112233445566778899aabbccddeeff0e1a00012c2209584f900c00
   13a115781c687474703a2f2f6578616d706c652e636f6d2f66696c65312e
   62696e1502030f0c0113a115781c687474703a2f2f6578616d706c652e63
   6f6d2f66696c65322e62696e1502030f0a49880c00030f0c01030f0c4584
   0c001702

   d86ba2025827815824822f5820d1e73f16e4126007bc4d804cd33b0209fb
   ab34728e60ee8c00f3387126748dd203590101a601010205035895a20282
   8141008141010458898c0c0014a40150fa6b4a53d5ad5fdfbe9de663e4d4
   1ffe02501492af1425695e48bf429b2d51f2ab45035824822f5820001122
   33445566778899aabbccddeeff0123456789abcdeffedcba98765432100e
   1987d0010f020f0c0114a2035824822f58200123456789abcdeffedcba98
   7654321000112233445566778899aabbccddeeff0e1a00012c2209584f90
   0c0013a115781c687474703a2f2f6578616d706c652e636f6d2f66696c65
   312e62696e1502030f0c0113a115781c687474703a2f2f6578616d706c65
   2e636f6d2f66696c65322e62696e1502030f0a49880c00030f0c01030f0c
   45840c001702

   Total size of Envelope with COSE authentication object: 380 382

   Envelope with COSE authentication object:

   a202587382582482025820de7c7927a15bd2eda59cab1512875f17c9f1e9
   e23885ce1ac6d671eefcefa37a584ad28443a10126a0f658408f5919c05e
   f786366ab4899db27a2e7412ef72480372437757b1c1c9f8b2ed2a677a88
   db17fcfbb47d178c9e5620f14ac68a314ceabcd20cbf54fbe89b8e83ad03
   590101a601010205035895a202828141008141010458898c0c0014a40150
   fa6b4a53d5ad5fdfbe9de663e4d41ffe02501492af1425695e48bf429b2d
   51f2ab450358248202582000112233445566778899aabbccddeeff012345
   6789abcdeffedcba98765432100e1987d0010f020f0c0114a20358248202
   58200123456789abcdeffedcba987654321000112233445566778899aabb
   ccddeeff0e1a00012c2209584f900c0013a115781c687474703a2f2f6578
   616d706c652e636f6d2f66696c65312e62696e1502030f0c0113a115781c
   687474703a2f2f6578616d706c652e636f6d2f66696c65322e62696e1502
   030f0a49880c00030f0c01030f0c45840c001702

   d86ba2025873825824822f5820d1e73f16e4126007bc4d804cd33b0209fb
   ab34728e60ee8c00f3387126748dd2584ad28443a10126a0f65840b7ae0a
   46a28f02e25cda6d9a255bbaf86330141831fae5a78012d648bc6cee5510
   2e0f1890bdeacc3adaa4fae0560f83a45eecae65cabce642f56d84ab97ef
   8d03590101a601010205035895a202828141008141010458898c0c0014a4
   0150fa6b4a53d5ad5fdfbe9de663e4d41ffe02501492af1425695e48bf42
   9b2d51f2ab45035824822f582000112233445566778899aabbccddeeff01
   23456789abcdeffedcba98765432100e1987d0010f020f0c0114a2035824
   822f58200123456789abcdeffedcba987654321000112233445566778899
   aabbccddeeff0e1a00012c2209584f900c0013a115781c687474703a2f2f
   6578616d706c652e636f6d2f66696c65312e62696e1502030f0c0113a115
   781c687474703a2f2f6578616d706c652e636f6d2f66696c65322e62696e
   1502030f0a49880c00030f0c01030f0c45840c001702

Appendix C.  C.  Design Rational

   In order to provide flexible behavior to constrained devices, while
   still allowing more powerful devices to use their full capabilities,
   the SUIT manifest encodes the required behavior of a Recipient
   device.  Behavior is encoded as a specialized byte code, contained in
   a CBOR list.  This promotes a flat encoding, which simplifies the
   parser.  The information encoded by this byte code closely matches
   the operations that a device will perform, which promotes ease of
   processing.  The core operations used by most update and trusted
   invocation operations are represented in the byte code.  The byte
   code can be extended by registering new operations.

   The specialized byte code approach gives benefits equivalent to those
   provided by a scripting language or conventional byte code, with two
   substantial differences.  First, the language is extremely high
   level, consisting of only the operations that a device may perform
   during update and trusted invocation of a firmware image.  Second,
   the language specifies linear behavior, without reverse branches.
   Conditional processing is supported, and parallel and out-of-order
   processing may be performed by sufficiently capable devices.

   By structuring the data in this way, the manifest processor becomes a
   very simple engine that uses a pull parser to interpret the manifest.
   This pull parser invokes a series of command handlers that evaluate a
   Condition or execute a Directive.  Most data is structured in a
   highly regular pattern, which simplifies the parser.

   The results of this allow a Recipient to implement a very small
   parser for constrained applications.  If needed, such a parser also
   allows the Recipient to perform complex updates with reduced
   overhead.  Conditional execution of commands allows a simple device
   to perform important decisions at validation-time.

   Dependency handling is vastly simplified as well.  Dependencies
   function like subroutines of the language.  When a manifest has a
   dependency, it can invoke that dependency's commands and modify their
   behavior by setting parameters.  Because some parameters come with
   security implications, the dependencies also have a mechanism to
   reject modifications to parameters on a fine-grained level.

   Developing a robust permissions system works in this model too.  The
   Recipient can use a simple ACL that is a table of Identities and
   Component Identifier permissions to ensure that operations on
   components fail unless they are permitted by the ACL.  This table can
   be further refined with individual parameters and commands.

   Capability reporting is similarly simplified.  A Recipient can report
   the Commands, Parameters, Algorithms, and Component Identifiers that
   it supports.  This is sufficiently precise for a manifest author to
   create a manifest that the Recipient can accept.

   The simplicity of design in the Recipient due to all of these
   benefits allows even a highly constrained platform to use advanced
   update capabilities.

C.1.  C.1 Design Rationale: Envelope

   The Envelope is used instead of a COSE structure for several reasons:

   1.  This enables the use of Severable Elements (Section 8.8)

   2.  This enables modular processing of manifests, particularly with
       large signatures.

   3.  This enables multiple authentication schemes.

   4.  This allows integrity verification by a dependent to be
       unaffected by adding or removing authentication structures.

   Modular processing is important because it allows a Manifest
   Processor to iterate forward over an Envelope, processing Delegation
   Chains and Authentication Blocks, retaining only intermediate values,
   without any need to seek forward and backwards in a stream until it
   gets to the Manifest itself.  This allows the use of large, Post-
   Quantum signatures without requiring retention of the signature
   itself, or seeking forward and back.

   Four authentication objects are supported by the Envelope:

   -  COSE_Sign_Tagged

   -  COSE_Sign1_Tagged

   -  COSE_Mac_Tagged

   -  COSE_Mac0_Tagged

   The SUIT Envelope allows an Update Authority or intermediary to mix
   and match any number of different authentication blocks it wants
   without any concern for modifying the integrity of another
   authentication block.  This also allows the addition or removal of an
   authentication blocks without changing the integrity check of the
   Manifest, which is important for dependency handling.  See
   Section 6.2

C.2.  C.2 Byte String Wrappers

   Byte string wrappers are used in several places in the suit manifest.
   The primary reason for wrappers it to limit the parser extent when
   invoked at different times, with a possible loss of context.

   The elements of the suit envelope are wrapped both to set the extents
   used by the parser and to simplify integrity checks by clearly
   defining the length of each element.

   The common block is re-parsed in order to find components identifiers
   from their indices, to find dependency prefixes and digests from
   their identifiers, and to find the common sequence.  The common
   sequence is wrapped so that it matches other sequences, simplifying
   the code path.

   A severed SUIT command sequence will appear in the envelope, so it
   must be wrapped as with all envelope elements.  For consistency,
   command sequences are also wrapped in the manifest.  This also allows
   the parser to discern the difference between a command sequence and a
   SUIT_Digest.

   Parameters that are structured types (arrays and maps) are also
   wrapped in a bstr.  This is so that parser extents can be set
   correctly using only a reference to the beginning of the parameter.
   This enables a parser to store a simple list of references to
   parameters that can be retrieved when needed.

Appendix D.  D.  Implementation Conformance Matrix

   This section summarizes the functionality a minimal manifest
   processor implementation needs to offer to claim conformance to this
   specification, in the absence of an application profile standard
   specifying otherwise.

   The subsequent table shows the conditions.

         +-------------------+------------------+----------------+
         | Name              | Reference        | Implementation |
         +-------------------+------------------+----------------+
         | Vendor Identifier | Section 8.7.5.2  | REQUIRED       |
         |                   |                  |                |
         | Class Identifier  | Section 8.7.5.2  | REQUIRED       |
         |                   |                  |                |
         | Device Identifier | Section 8.7.5.2  | OPTIONAL       |
         |                   |                  |                |
         | Image Match       | Section 8.7.6.2  | REQUIRED       |
         |                   |                  |                |
         | Image Not Match   | Section 8.7.6.3  | OPTIONAL       |
         |                   |                  |                |
         | Use Before        | Section 8.7.6.4  | OPTIONAL       |
         |                   |                  |                |
         | Component Offset Slot    | Section 8.7.6.5  | OPTIONAL       |
         |                   |                  |                |
         | Abort             | Section 8.7.6.9  | OPTIONAL       |
         |                   |                  |                |
         | Minimum Battery   | Section 8.7.6.6  | OPTIONAL       |
         |                   |                  |                |
         | Update Authorized | Section 8.7.6.7  | OPTIONAL       |
         |                   |                  |                |
         | Version           | Section 8.7.6.8  | OPTIONAL       |
         |                   |                  |                |
         | Custom Condition  | Section 8.7.6.10 | OPTIONAL       |
         +-------------------+------------------+----------------+

   The subsequent table shows the directives.

   +-------------------+----------------+------------------------------+
   | Name              | Reference      | Implementation               |
   +-------------------+----------------+------------------------------+
   | Set Component     | Section 8.7.7. | REQUIRED if more than one    |
   | Index             | 1              | component                    |
   |                   |                |                              |
   | Set Dependency    | Section 8.7.7. | REQUIRED if dependencies     |
   | Index             | 2              | used                         |
   |                   |                |                              |
   | Try Each          | Section 8.7.7. | OPTIONAL                     |
   |                   | 3              |                              |
   |                   |                |                              |
   | Process           | Section 8.7.7. | OPTIONAL                     |
   | Dependency        | 4              |                              |
   |                   |                |                              |
   | Set Parameters    | Section 8.7.7. | OPTIONAL                     |
   |                   | 5              |                              |
   |                   |                |                              |
   | Override          | Section 8.7.7. | REQUIRED                     |
   | Parameters        | 6              |                              |
   |                   |                |                              |
   | Fetch             | Section 8.7.7. | REQUIRED for Updater         |
   |                   | 7              |                              |
   |                   |                |                              |
   | Copy              | Section 8.7.7. | OPTIONAL                     |
   |                   | 9              |                              |
   |                   |                |                              |
   | Run               | Section 8.7.7. | REQUIRED for Bootloader      |
   |                   | 10             |                              |
   |                   |                |                              |
   | Wait For Event    | Section 8.7.7. | OPTIONAL                     |
   |                   | 11             |                              |
   |                   |                |                              |
   | Run Sequence      | Section 8.7.7. | OPTIONAL                     |
   |                   | 12             |                              |
   |                   |                |                              |
   | Swap              | Section 8.7.7. | OPTIONAL                     |
   |                   | 13             |                              |
   |                   |                |                              |
   | Fetch URI List    | Section 8.7.7. | OPTIONAL                     |
   |                   | 8              |                              |
   |                   |                |                              |
   | Garbage Collect Unlink            | Section 8.7.8  | OPTIONAL                     |
   +-------------------+----------------+------------------------------+

   The subsequent table shows the parameters.

      +------------------+------------------+----------------------+
      | Name             | Reference        | Implementation       |
      +------------------+------------------+----------------------+
      | Vendor ID        | Section 8.7.5.3  | REQUIRED             |
      |                  |                  |                      |
      | Class ID         | Section 8.7.5.4  | REQUIRED             |
      |                  |                  |                      |
      | Image Digest     | Section 8.7.5.6  | REQUIRED             |
      |                  |                  |                      |
      | Image Size       | Section 8.7.5.7  | REQUIRED             |
      |                  |                  |                      |
      | Use Before       | Section 8.7.5.8  | RECOMMENDED          |
      |                  |                  |                      |
      | Component Offset Slot   | Section 8.7.5.9  | OPTIONAL             |
      |                  |                  |                      |
      | Encryption Info  | Section 8.7.5.10 | RECOMMENDED          |
      |                  |                  |                      |
      | Compression Info | Section 8.7.5.11 | RECOMMENDED          |
      |                  |                  |                      |
      | Unpack Info      | Section 8.7.5.12 | RECOMMENDED          |
      |                  |                  |                      |
      | URI              | Section 8.7.5.13 | REQUIRED for Updater |
      |                  |                  |                      |
      | Source Component | Section 8.7.5.14 | OPTIONAL             |
      |                  |                  |                      |
      | Run Args         | Section 8.7.5.15 | OPTIONAL             |
      |                  |                  |                      |
      | Device ID        | Section 8.7.5.5  | OPTIONAL             |
      |                  |                  |                      |
      | Minimum Battery  | Section 8.7.5.16 | OPTIONAL             |
      |                  |                  |                      |
      | Update Priority  | Section 8.7.5.17 | OPTIONAL             |
      |                  |                  |                      |
      | Version Match    | Section 8.7.5.18 | OPTIONAL             |
      |                  |                  |                      |
      | Wait Info        | Section 8.7.5.19 | OPTIONAL             |
      |                  |                  |                      |
      | URI List         | Section 8.7.5.20 | OPTIONAL             |
      |                  |                  |                      |
      | Strict Order     | Section 8.7.5.22 | OPTIONAL             |
      |                  |                  |                      |
      | Soft Failure     | Section 8.7.5.23 | OPTIONAL             |
      |                  |                  |                      |
      | Custom           | Section 8.7.5.24 | OPTIONAL             |
      +------------------+------------------+----------------------+

Authors' Addresses

   Brendan Moran
   Arm Limited

   EMail: Brendan.Moran@arm.com

   Hannes Tschofenig
   Arm Limited

   EMail: hannes.tschofenig@arm.com

   Henk Birkholz
   Fraunhofer SIT

   EMail: henk.birkholz@sit.fraunhofer.de

   Koen Zandberg
   Inria

   EMail: koen.zandberg@inria.fr