A Concise Binary Object Representation (CBOR)-based Serialization Format for the Software Updates for Internet of Things (SUIT) Manifest
draft-ietf-suit-manifest-34
| Document | Type | Active Internet-Draft (suit WG) | |
|---|---|---|---|
| Authors | Brendan Moran , Hannes Tschofenig , Henk Birkholz , Koen Zandberg , Øyvind Rønningstad | ||
| Last updated | 2025-05-28 | ||
| Replaces | draft-moran-suit-manifest | ||
| RFC stream | Internet Engineering Task Force (IETF) | ||
| Intended RFC status | Proposed Standard | ||
| Formats | |||
| Reviews | |||
| Additional resources |
GitHub Repository
C implementation: Manifest Generator and Parser Python implementation 2: Manifest Generator Python implementation: Manifest Generator Mailing list discussion |
||
| Stream | WG state | Submitted to IESG for Publication | |
| Document shepherd | Russ Housley | ||
| Shepherd write-up | Show Last changed 2024-11-04 | ||
| IESG | IESG state | RFC Ed Queue | |
| Action Holders |
(None)
|
||
| Consensus boilerplate | Yes | ||
| Telechat date | (None) | ||
| Responsible AD | Roman Danyliw | ||
| Send notices to | David Waltermire <david.waltermire@nist.gov>, housley@vigilsec.com | ||
| IANA | IANA review state | Version Changed - Review Needed | |
| IANA action state | RFC-Ed-Ack | ||
| IANA expert review state | Expert Reviews OK | ||
| IANA expert review comments | The expert has approved the CBOR Tag registrations, but noted that the "Data Item" field should read "map." Because IANA didn't receive a positive or negative response from the authors when our Last Call review identified the Data Item as "unsigned or negative integer," and the document doesn't explicitly mention the Data Item field, we need the authors to confirm that they agree that "map" should be used (and, when possible, include it in the IANA Considerations section). | ||
| RFC Editor | RFC Editor state | MISSREF | |
| Details |
draft-ietf-suit-manifest-34
Network Working Group B. Moran
Internet-Draft Arm Limited
Intended status: Standards Track H. Tschofenig
Expires: 29 November 2025 H-BRS
H. Birkholz
Fraunhofer SIT
K. Zandberg
Inria
Ø. Rønningstad
Nordic Semiconductor
28 May 2025
A Concise Binary Object Representation (CBOR)-based Serialization Format
for the Software Updates for Internet of Things (SUIT) Manifest
draft-ietf-suit-manifest-34
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 Internet of Things (IoT) device), where to find
the 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
Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet-
Drafts is at https://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
This Internet-Draft will expire on 29 November 2025.
Moran, et al. Expires 29 November 2025 [Page 1]
Internet-Draft CBOR-based SUIT Manifest May 2025
Copyright Notice
Copyright (c) 2025 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents (https://trustee.ietf.org/
license-info) in effect on the date of publication of this document.
Please review these documents carefully, as they describe your rights
and restrictions with respect to this document. Code Components
extracted from this document must include Revised BSD License text as
described in Section 4.e of the Trust Legal Provisions and are
provided without warranty as described in the Revised BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 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 . . . . . . . . . . . . . . . . . . . . . . . . 12
5.2. Authentication Block . . . . . . . . . . . . . . . . . . 13
5.3. Manifest . . . . . . . . . . . . . . . . . . . . . . . . 13
5.3.1. Critical Metadata . . . . . . . . . . . . . . . . . . 13
5.3.2. Common . . . . . . . . . . . . . . . . . . . . . . . 13
5.3.3. Command Sequences . . . . . . . . . . . . . . . . . . 14
5.3.4. Integrity Check Values . . . . . . . . . . . . . . . 14
5.3.5. Human-Readable Text . . . . . . . . . . . . . . . . . 15
5.4. Severable Elements . . . . . . . . . . . . . . . . . . . 15
5.5. Integrated Payloads . . . . . . . . . . . . . . . . . . . 15
6. Manifest Processor Behavior . . . . . . . . . . . . . . . . . 16
6.1. Manifest Processor Setup . . . . . . . . . . . . . . . . 16
6.2. Required Checks . . . . . . . . . . . . . . . . . . . . 17
6.3. Interpreter Fundamental Properties . . . . . . . . . . . 18
6.3.1. Resilience to Disruption . . . . . . . . . . . . . . 18
6.4. Abstract Machine Description . . . . . . . . . . . . . . 19
6.5. Special Cases of Component Index . . . . . . . . . . . . 21
6.6. Serialized Processing Interpreter . . . . . . . . . . . . 22
6.7. Parallel Processing Interpreter . . . . . . . . . . . . . 23
7. Creating Manifests . . . . . . . . . . . . . . . . . . . . . 24
7.1. Compatibility Check Template . . . . . . . . . . . . . . 25
7.2. Trusted Invocation Template . . . . . . . . . . . . . . . 25
7.3. Component Download Template . . . . . . . . . . . . . . . 26
7.4. Install Template . . . . . . . . . . . . . . . . . . . . 26
7.5. Integrated Payload Template . . . . . . . . . . . . . . . 27
Moran, et al. Expires 29 November 2025 [Page 2]
Internet-Draft CBOR-based SUIT Manifest May 2025
7.6. Load from Nonvolatile Storage Template . . . . . . . . . 27
7.7. A/B Image Template . . . . . . . . . . . . . . . . . . . 28
8. Metadata Structure . . . . . . . . . . . . . . . . . . . . . 29
8.1. Encoding Considerations . . . . . . . . . . . . . . . . . 30
8.2. Envelope . . . . . . . . . . . . . . . . . . . . . . . . 30
8.3. Authenticated Manifests . . . . . . . . . . . . . . . . . 30
8.4. Manifest . . . . . . . . . . . . . . . . . . . . . . . . 31
8.4.1. suit-manifest-version . . . . . . . . . . . . . . . . 32
8.4.2. suit-manifest-sequence-number . . . . . . . . . . . . 32
8.4.3. suit-reference-uri . . . . . . . . . . . . . . . . . 32
8.4.4. suit-text . . . . . . . . . . . . . . . . . . . . . . 32
8.4.5. suit-common . . . . . . . . . . . . . . . . . . . . . 34
8.4.6. SUIT_Command_Sequence . . . . . . . . . . . . . . . . 35
8.4.7. Reporting Policy . . . . . . . . . . . . . . . . . . 37
8.4.8. SUIT_Parameters . . . . . . . . . . . . . . . . . . . 38
8.4.9. SUIT_Condition . . . . . . . . . . . . . . . . . . . 46
8.4.10. SUIT_Directive . . . . . . . . . . . . . . . . . . . 49
8.4.11. suit-command-custom . . . . . . . . . . . . . . . . . 54
8.4.12. Integrity Check Values . . . . . . . . . . . . . . . 55
8.5. Implementation Conformance Matrix . . . . . . . . . . . . 55
8.6. Severable Elements . . . . . . . . . . . . . . . . . . . 57
9. Access Control Lists . . . . . . . . . . . . . . . . . . . . 58
10. SUIT Digest Container . . . . . . . . . . . . . . . . . . . . 59
11. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 59
11.1. SUIT Envelope Elements . . . . . . . . . . . . . . . . . 60
11.2. SUIT Manifest Elements . . . . . . . . . . . . . . . . . 61
11.3. SUIT Common Elements . . . . . . . . . . . . . . . . . . 62
11.4. SUIT Commands . . . . . . . . . . . . . . . . . . . . . 63
11.5. SUIT Parameters . . . . . . . . . . . . . . . . . . . . 65
11.6. SUIT Text Values . . . . . . . . . . . . . . . . . . . . 66
11.7. SUIT Component Text Values . . . . . . . . . . . . . . 66
11.8. Expert Review Instructions . . . . . . . . . . . . . . . 67
11.9. Media Type Registration . . . . . . . . . . . . . . . . 68
12. Security Considerations . . . . . . . . . . . . . . . . . . . 70
13. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 72
14. References . . . . . . . . . . . . . . . . . . . . . . . . . 73
14.1. Normative References . . . . . . . . . . . . . . . . . . 73
14.2. Informative References . . . . . . . . . . . . . . . . . 75
Appendix A. Full CDDL . . . . . . . . . . . . . . . . . . . . . 75
Appendix B. Examples . . . . . . . . . . . . . . . . . . . . . . 82
B.1. Example 0: Secure Boot . . . . . . . . . . . . . . . . . 83
B.2. Example 1: Simultaneous Download and Installation of
Payload . . . . . . . . . . . . . . . . . . . . . . . . . 85
B.3. Example 2: Simultaneous Download, Installation, Secure
Boot, Severed Fields . . . . . . . . . . . . . . . . . . 87
B.4. Example 3: A/B images . . . . . . . . . . . . . . . . . . 90
B.5. Example 4: Load from External Storage . . . . . . . . . . 93
B.6. Example 5: Two Images . . . . . . . . . . . . . . . . . . 96
Moran, et al. Expires 29 November 2025 [Page 3]
Internet-Draft CBOR-based SUIT Manifest May 2025
Appendix C. Design Rationale . . . . . . . . . . . . . . . . . . 99
C.1. C.1 Design Rationale: Envelope . . . . . . . . . . . . . 100
C.2. C.2 Byte String Wrappers . . . . . . . . . . . . . . . . 101
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 102
1. Introduction
A firmware update mechanism is an essential security feature for IoT
devices to deal with vulnerabilities. The transport of firmware
images to the devices themselves is important security aspect.
Luckily, there are already various device management solutions
available offering the distribution of firmware images to IoT
devices. 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. Firmware signing 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 and to
distribute the content encryption key securely. The support for
firmware and payload encryption via the SUIT manifest format is
described in a companion document
[I-D.ietf-suit-firmware-encryption]. 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 about the firmware for an IoT
device, where to find the firmware, and the devices to which it
applies.
This specification defines the SUIT manifest format. It is intended
to meet several goals:
* Meet the requirements defined in [RFC9124].
* 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.
Moran, et al. Expires 29 November 2025 [Page 4]
Internet-Draft CBOR-based SUIT Manifest May 2025
* Extensible.
The SUIT manifest can be used for a variety of purposes throughout
its lifecycle, such as enabling:
* a Network Operator to reason about compatibility of a firmware,
such as timing and acceptance of firmware updates.
* a Device Operator to reason about the impact of a firmware.
* a device to evaluate the authenticity of a firmware and the
authority of the firmware author prior to installation.
* a device to evaluate the applicability of a firmware.
* a device to determine the installation process of a firmware.
* a device to evaluate the authenticity of a firmware pre-boot
* a device to determine the encoding and boot process of a firmware.
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 [RFC9019] and the threats, requirements,
and user stories in [RFC9124].
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 language is tailored to
software updates and Trusted Invocation.
Moran, et al. Expires 29 November 2025 [Page 5]
Internet-Draft CBOR-based SUIT Manifest May 2025
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 SUIT
Information Model [RFC9124] 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 [RFC9397].
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. Severable
elements can be removed from the manifest without impacting its
security, see Section 8.6.
* Update: One or more manifests that describe one or more payloads.
Moran, et al. Expires 29 November 2025 [Page 6]
Internet-Draft CBOR-based SUIT Manifest May 2025
* 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.
Moran, et al. Expires 29 November 2025 [Page 7]
Internet-Draft CBOR-based SUIT Manifest May 2025
* 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.
* Pull parser: A parser that traverses the data and extracts
information on an as-needed basis.
* Severable element: An element of the manifest that supports
elision of hashed data. If a hash of the data is included in the
manifest and the data is included in the envelope, then that data
may be elided.
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.
Moran, et al. Expires 29 November 2025 [Page 8]
Internet-Draft CBOR-based SUIT Manifest May 2025
The complete CDDL ([RFC8610]) definition is provided in Appendix A,
examples are given in Appendix B and a design rationale is offered in
Appendix C. Finally, Section 8.5 summarizes the mandatory-to-
implement features of this specification.
Additional specifications describe functionality needed to implement
all of the requirements of [RFC9124], such as:
* Firmware encryption [I-D.ietf-suit-firmware-encryption]
* Update management [I-D.ietf-suit-update-management]
* Dependency manifests [I-D.ietf-suit-trust-domains]
* Secure reporting of the update status [I-D.ietf-suit-report]
A technique to compress firmware images may be standardized in the
future.
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 [RFC9019]. The security aspects are described in [RFC9124].
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.
* intermittent or unstable connectivity.
* intermittent power, for example due to energy harvesting.
Moran, et al. Expires 29 November 2025 [Page 9]
Internet-Draft CBOR-based SUIT Manifest May 2025
* 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.
* 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 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.
Moran, et al. Expires 29 November 2025 [Page 10]
Internet-Draft CBOR-based SUIT Manifest May 2025
2. Verify the applicability of the manifest.
3. Fetch payload(s).
4. Install payload(s).
5. Verify image(s).
When installation is complete, similar information can be used for
validating and invoking images in a further three steps:
1. Verify image(s).
2. Load image(s).
3. Invoke image(s).
If verification and invocation 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. Because signature verifications can be costly in
constrained applications, the bootloader may add its own
authentication, e.g., a Message Authentication Code (MAC), to the
manifest in order to prevent further signature verifications and save
energy, provided that the bootloader can protect its authentication
key.
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 8.4
The manifest is structured from several key components:
1. The Envelope (see Section 5.1) contains the Authentication Block,
the Manifest, any Severable Elements, and any Integrated
Payloads.
2. The Authentication Block (see Section 5.2) contains a list of
signatures or MACs of the manifest.
3. The Manifest (see Section 5.3) contains all critical, non-
severable metadata that the Recipient requires. It is further
broken down into:
1. Critical metadata, such as sequence number.
Moran, et al. Expires 29 November 2025 [Page 11]
Internet-Draft CBOR-based SUIT Manifest May 2025
2. Common metadata, such as affected components.
3. Command sequences, directing the Recipient how to install and
use the payload(s).
4. Integrity check values for severable elements.
4. Severable elements (see Section 5.4).
5. Integrated payloads (see Section 5.5).
The diagram below illustrates the hierarchy of the Envelope.
+-------------------------+
| Envelope |
+-------------------------+
| Authentication Block |
| Manifest --------------> +------------------------------+
| Severable Elements | | Manifest |
| Integrated Payloads | +------------------------------+
+-------------------------+ | Structure Version |
| Sequence Number |
| Reference to Full Manifest |
+------ Common Structure |
| +---- Command Sequences |
+-------------------------+ | | | Digests of Envelope Elements |
| Common Structure | <--+ | +------------------------------+
+-------------------------+ |
| Components IDs | +-> +-----------------------+
| Common Command Sequence ---------> | Command Sequence |
+-------------------------+ +-----------------------+
| List of ( pairs of ( |
| * command code |
| * argument / |
| reporting policy |
| )) |
+-----------------------+
5.1. Envelope
The SUIT Envelope is a container that encloses the Authentication
Block, the Manifest, any Severable Elements, and any integrated
payloads. 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 avoids substantial complexity that would be needed with existing
solutions. See Appendix C.1 for a description of the reasoning for
this.
Moran, et al. Expires 29 November 2025 [Page 12]
Internet-Draft CBOR-based SUIT Manifest May 2025
See Section 8.2 for more detail.
5.2. Authentication Block
The Authentication Block contains a bstr-wrapped SUIT Digest
Container, see Section 10, and one or more [RFC9052] 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 8.3 for more detail.
5.3. 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 8.4 for more detail.
5.3.1. 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 8.4.1, Section 8.4.2, and Section 8.4.3 for more detail.
5.3.2. 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 two
parts: 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
Moran, et al. Expires 29 November 2025 [Page 13]
Internet-Draft CBOR-based SUIT Manifest May 2025
have any side-effects outside of setting parameter values.
See Section 8.4.5 for more detail.
5.3.3. 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 5.3.2), update commands, and secure boot
commands.
Update Command Sequences are: Payload Fetch, Payload Installation
and, System Validation. 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. An 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 (dependencies are not defined in this
specification).
See Section 8.4.6 for more detail.
5.3.4. Integrity Check Values
To enable severable elements Section 5.4, there needs to be a
mechanism to verify the integrity of the severed data. While the
severed data stays outside the manifest, for efficiency reasons,
Integrity Check Values are used to include the digest of the data in
the manifest. Note that Integrated Payloads, see Section 5.5, are
integrity-checked using Command Sequences.
See Section 8.4.12 for more detail.
Moran, et al. Expires 29 November 2025 [Page 14]
Internet-Draft CBOR-based SUIT Manifest May 2025
5.3.5. Human-Readable Text
Text is typically a Severable Element (Section 5.4). 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 8.4.4 for more detail.
5.4. Severable Elements
Severable Elements are elements of the Envelope (Section 5.1) that
have Integrity Check Values (Section 5.3.4) in the Manifest
(Section 5.3). This is a form of elision of hashed data. The
elements in the envelope are verified by Integrity Check Values and
therefore cannot be replaced with other elements even if they are
authenticated elements.
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 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 8.6 for more detail.
5.5. Integrated Payloads
In some cases, it is beneficial to include 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 transports a small payload, such as an encrypted
key, that payload may be placed in the manifest's envelope.
See Section 7.5 for more detail.
Moran, et al. Expires 29 November 2025 [Page 15]
Internet-Draft CBOR-based SUIT Manifest May 2025
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.
* Application crashed when executed.
* Watchdog timeout occurred.
* Payload verification failed.
* Missing required component from a Component Set.
Moran, et al. Expires 29 November 2025 [Page 16]
Internet-Draft CBOR-based SUIT Manifest May 2025
* 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 one possible strategy to provide robustness of the
firmware update process. 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 [RFC9124], 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 manifest processor MUST 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.
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.
Once a valid, authentic manifest has been selected, the manifest
processor MUST examine the component list and check that the number
of components listed in the manifest is not larger than the number in
the target system.
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 shared sequence contains
at least Check Vendor Identifier command and at least one Check Class
Identifier command.
Because the shared sequence contains Check Vendor Identifier and
Check Class Identifier command(s), no custom commands are permitted
in the shared sequence. This ensures that any custom commands are
only executed by devices that understand them.
If the manifest contains more than one component, each command
sequence MUST begin with a Set Component Index Section 8.4.10.1.
Moran, et al. Expires 29 November 2025 [Page 17]
Internet-Draft CBOR-based SUIT Manifest May 2025
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:
1. the manifest Author has sufficient permissions for the requested
operations (see Section 9) and
2. the manifest specifies a digest and a payload for every Component
in the Component Set.
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 correct
system state that can be checked against known digests.
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.
6.3.1. Resilience to Disruption
As required in Section 3 of [RFC9019] and as an extension of design
goal 1, devices must remain operable after a disruption, such as a
power failure or network interruption, interrupts the update process.
The manifest processor must be resilient to these faults. In order
to enable this resilience, systems implementing the manifest
processor MUST guarantee that manifests can be either resumed or
reapplied.
This can be achieved in a variety of ways: 1. A fallback/recovery
image is provided so that a disrupted system can apply the SUIT
Manifest again. 2. Manifest Authors construct Manifests in such a
way that repeated partial invocations of any Manifest always results
in a correct system state. Typically this is done by using Try-Each
and Conditions to bypass operations that have already been completed.
3. A journal of manifest operations is stored in nonvolatile memory.
The journal enables the parser to re-create the state just prior to
the disruption. This journal can, for example, be a SUIT Report or a
journaling file system. 4. Where a command is not repeatable because
Moran, et al. Expires 29 November 2025 [Page 18]
Internet-Draft CBOR-based SUIT Manifest May 2025
of the way in which it alters system state (e.g., swapping images or
in-place delta) it is resumable or revertible. This applies
primarily to commands that modify at least one source component as
well as the destination component.
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. 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 8.4.8.15) 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:
current := components[component-index]
As a result, Set Component Index is described as current :=
components[arg].
The following table describes the semantics of each operation. The
pseudo-code semantics are inspired by the Python programming
language.
Moran, et al. Expires 29 November 2025 [Page 19]
Internet-Draft CBOR-based SUIT Manifest May 2025
+========================+========================================+
| pseudo-code operation | Semantics |
+========================+========================================+
| assert(test) | When test is false, causes an error |
| | return |
+------------------------+----------------------------------------+
| store(dest, source) | Writes source into dest |
+------------------------+----------------------------------------+
| expression0 for-each e | Performs expression0 once for each |
| in l else expression1 | element in iterable l; performs |
| | expression1 if no break is encountered |
+------------------------+----------------------------------------+
| break | halt a for-each loop |
+------------------------+----------------------------------------+
| now() | return the current UTC time |
+------------------------+----------------------------------------+
| expression if test | performs expression if test is true |
+------------------------+----------------------------------------+
Table 1
The following table describes the behavior of each command. "params"
represents the parameters for the current component. Most commands
operate on a component.
+=========================+======================================+
| Command Name | Semantic of the Operation |
+=========================+======================================+
| Check Vendor Identifier | assert(binary-match(current, |
| | current.params[vendor-id])) |
+-------------------------+--------------------------------------+
| Check Class Identifier | assert(binary-match(current, |
| | current.params[class-id])) |
+-------------------------+--------------------------------------+
| Verify Image | assert(binary-match(digest(current), |
| | current.params[digest])) |
+-------------------------+--------------------------------------+
| Check Content | assert(binary-match(current, |
| | current.params[content])) |
+-------------------------+--------------------------------------+
| Set Component Index | current := components[arg] |
+-------------------------+--------------------------------------+
| Override Parameters | current.params[k] := v for-each k,v |
| | in arg |
+-------------------------+--------------------------------------+
| Invoke | invoke(current) |
+-------------------------+--------------------------------------+
| Fetch | store(current, |
Moran, et al. Expires 29 November 2025 [Page 20]
Internet-Draft CBOR-based SUIT Manifest May 2025
| | fetch(current.params[uri])) |
+-------------------------+--------------------------------------+
| Write | store(current, |
| | current.params[content]) |
+-------------------------+--------------------------------------+
| Use Before | assert(now() < arg) |
+-------------------------+--------------------------------------+
| Check Component Slot | assert(current.slot-index == arg) |
+-------------------------+--------------------------------------+
| Check Device Identifier | assert(binary-match(current, |
| | current.params[device-id])) |
+-------------------------+--------------------------------------+
| Abort | assert(0) |
+-------------------------+--------------------------------------+
| Try Each | (break if (exec(seq) is not error)) |
| | for-each seq in arg else assert(0) |
+-------------------------+--------------------------------------+
| Copy | store(current, current.params[src- |
| | component]) |
+-------------------------+--------------------------------------+
| Swap | swap(current, current.params[src- |
| | component]) |
+-------------------------+--------------------------------------+
| Run Sequence | exec(arg) |
+-------------------------+--------------------------------------+
| Invoke with Arguments | invoke(current, arg) |
+-------------------------+--------------------------------------+
Table 2
6.5. Special Cases of Component Index
Component Index can take on one of three types:
1. Integer
2. Array of integers
3. True
Integers MUST always be supported by Set Component Index. Arrays of
integers MUST be supported by Set Component Index if the Recipient
supports 3 or more components. True MUST be supported by Set
Component Index if the Recipient supports 2 or more components. Each
of these operates on the list of components declared in the manifest.
Moran, et al. Expires 29 November 2025 [Page 21]
Internet-Draft CBOR-based SUIT Manifest May 2025
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) to which each subsequent command applies. The
value True replaces the list of component indices with the full list
of components, as defined in the manifest.
When a command is executed, it
1. operates on the component identified by the component index if
that index is an integer, or
2. it operates on each component identified by an array of indicies,
or
3. it operates on every component 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:
current-list = [ components[component-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. This
means that the sequences that are arguments to Try Each and Run
Sequence are not invoked with Component 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 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.
Moran, et al. Expires 29 November 2025 [Page 22]
Internet-Draft CBOR-based SUIT Manifest May 2025
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 index of
True, it does not ignore any commands. It applies them to the
current component on each iteration.
6.7. Parallel Processing Interpreter
To enable parallel or out-of-order processing of Command Sequences,
Recipients MAY make use of the Strict Order parameter. The Strict
Order parameter indicates to the Manifest Processor that Commands
MUST be executed strictly in order. When the Strict Order parameter
is False, this indicates to the Manifest Processor that Commands MAY
be executed in parallel and/or out of order.
To perform parallel processing, once the Strict Order parameter is
set to False, the Recipient MAY add each command to an issue queue
for parallel processing or an issue pool for out-of-order processing.
The Manifest Processor then executes these pending commands in
whatever order or parallelism it deems appropriate. Once there are
no more commands to add to the issue queue/pool, the Manifest
Processor drains the issue queue/pool by issuing all pending commands
and waits for every issued command to complete. The Manifest
Processor MAY issue commands before it has completed adding all
remaining commands to the issue queue/pool.
While adding commands to the issue queue or pool, if the Manifest
Processor encounters any of the following commands, it MUST treat the
command as a barrier, draining the issue queue/pool and waiting for
all issued commands to complete.
* Override Parameters.
* Set Strict Order = True.
* Set Component Index.
Extensions MAY alter this list. Once all issued commands have
completed, the Manifest Processor issues the barrier command, after
which it may resume parallel processing if Strict Order is still
False.
Moran, et al. Expires 29 November 2025 [Page 23]
Internet-Draft CBOR-based SUIT Manifest May 2025
A Component MUST NOT be both a target of an operation and a source of
data (for example, in Copy or Swap) in a Command Sequence where
Strict Order is False. This would cause a race condition if the
Component is written to, then later read from. The Manifest
Processor MUST issue an Abort if it detects this exception.
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. There are several
invocation options for Run Sequence:
* Component Index is a positive integer, Strict Order is False:
Strict Order is set to True before the sequence argument is run.
The sequence argument MUST begin with set-component-index.
* Component Index is true or an array of positive integers, Strict
Order is False: The sequence argument is run once for each
component (or each component in the array); the Manifest Processor
presets the component index and Strict Order = True before each
iteration of the sequence argument.
* Component Index is a positive integer, Strict Order is True: No
special considerations
* Component Index is True or an array of positive integers, Strict
Order is True: The sequence argument is run once for each
component (or each component in the array); the Manifest Processor
presets the component index before each iteration of the sequence
argument.
These rules isolate each sequence from each other sequence, ensuring
that they operate as expected. When Strict Order = False, any
further Set Component Index directives in the Run Sequence command
sequence argument 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.
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 [RFC9052].
Moran, et al. Expires 29 November 2025 [Page 24]
Internet-Draft CBOR-based SUIT Manifest May 2025
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,
this means that the parameters consumed by each command MUST have
been set for each Component.
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, Set Component
Index has no effect and can be omitted.
NOTE: *A digest MUST always be set using Override Parameters.*
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 shared sequence
and the following sequence of commands is used:
* Set Component Index directive (see Section 8.4.10.1)
* Override Parameters directive (see Section 8.4.10.3) for Vendor ID
and Class ID (see Section 8.4.8)
* Check Vendor Identifier condition (see Section 8.4.8.2)
* Check Class Identifier condition (see Section 8.4.8.2)
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 shared sequence:
* Set Component Index directive (see Section 8.4.10.1)
* Override Parameters directive (see Section 8.4.10.3) for Image
Digest and Image Size (see Section 8.4.8)
Moran, et al. Expires 29 November 2025 [Page 25]
Internet-Draft CBOR-based SUIT Manifest May 2025
The system validation sequence contains the following commands:
* Set Component Index directive (see Section 8.4.10.1)
* Check Image Match condition (see Section 8.4.9.2)
Then, the run sequence contains the following commands:
* Set Component Index directive (see Section 8.4.10.1)
* Invoke directive (see Section 8.4.10.7)
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 shared sequence:
* Set Component Index directive (see Section 8.4.10.1)
* Override Parameters directive (see Section 8.4.10.3) for Image
Digest and Image Size (see Section 8.4.8)
Then, the install sequence contains the following commands:
* Set Component Index directive (see Section 8.4.10.1)
* Override Parameters directive (see Section 8.4.10.3) for URI (see
Section 8.4.8.10)
* Fetch directive (see Section 8.4.10.4)
* Check Image Match condition (see Section 8.4.9.2)
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.
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.
Moran, et al. Expires 29 November 2025 [Page 26]
Internet-Draft CBOR-based SUIT Manifest May 2025
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 8.4.10.1)
* Override Parameters directive (see Section 8.4.10.3) for Source
Component (see Section 8.4.8.11)
* Copy directive (see Section 8.4.10.5)
* Check Image Match condition (see Section 8.4.9.2)
7.5. 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).
An Author MAY choose to place a payload in the envelope of a
manifest. The payload envelope key MUST be a string. The payload
MUST be serialized in a bstr element.
The URI for a payload enclosed in this way MAY be expressed as a
fragment-only reference, as defined in [RFC3986], Section 4.4, for
example: "#device-model-v1.2.3.bin".
An intermediary, such as a Network Operator, MAY choose to pre-fetch
a payload and add it to the manifest envelope, using the URI as the
key.
7.6. 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 8.4.10.1)
* Override Parameters directive (see Section 8.4.10.3) for Source
Component (see Section 8.4.8)
* Copy directive (see Section 8.4.10.5)
Moran, et al. Expires 29 November 2025 [Page 27]
Internet-Draft CBOR-based SUIT Manifest May 2025
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.
7.7. 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 8.4.10.1)
* Try Each
- First Sequence:
o Override Parameters directive (see Section 8.4.10.3,
Section 8.4.8) for Slot A
o Check Slot Condition (see Section 8.4.9.4)
o Override Parameters directive (see Section 8.4.10.3) for
Image Digest A and Image Size A (see Section 8.4.8)
- Second Sequence:
o Override Parameters directive (see Section 8.4.10.3,
Section 8.4.8) for Slot B
o Check Slot Condition (see Section 8.4.9.4)
o Override Parameters directive (see Section 8.4.10.3) for
Image Digest B and Image Size B (see Section 8.4.8)
The following commands are placed in the fetch block or install block
* Set Component Index directive (see Section 8.4.10.1)
* Try Each
- First Sequence:
o Override Parameters directive (see Section 8.4.10.3,
Section 8.4.8) for Slot A
o Check Slot Condition (see Section 8.4.9.4)
Moran, et al. Expires 29 November 2025 [Page 28]
Internet-Draft CBOR-based SUIT Manifest May 2025
o Set Parameters directive (see Section 8.4.10.3) for URI A
(see Section 8.4.8)
- Second Sequence:
o Override Parameters directive (see Section 8.4.10.3,
Section 8.4.8) for Slot B
o Check Slot Condition (see Section 8.4.9.4)
o Set Parameters directive (see Section 8.4.10.3) for URI B
(see Section 8.4.8)
* Fetch
If Trusted Invocation (Section 7.2) is used, only the run sequence is
added to this template, since the shared sequence is populated by
this template:
* Set Component Index directive (see Section 8.4.10.1)
* Try Each
- First Sequence:
o Override Parameters directive (see Section 8.4.10.3,
Section 8.4.8) for Slot A
o Check Slot Condition (see Section 8.4.9.4)
- Second Sequence:
o Override Parameters directive (see Section 8.4.10.3,
Section 8.4.8) for Slot B
o Check Slot Condition (see Section 8.4.9.4)
* Invoke
NOTE: Any test can be used to select between images, Check 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: Authentication Information, Manifest, Severable
Elements and Integrated Payloads.
Moran, et al. Expires 29 November 2025 [Page 29]
Internet-Draft CBOR-based SUIT Manifest May 2025
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.
All CBOR maps in the Manifest and manifest envelope MUST be encoded
with the canonical CBOR ordering as defined in [RFC8949].
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. Authenticated Manifests
SUIT_Authentication contains a list of elements, which consist of a
SUIT_Digest calculated over the manifest, and zero or more
SUIT_Authentication_Block's calculated over the SUIT_Digest.
SUIT_Authentication = [
bstr .cbor SUIT_Digest,
* bstr .cbor SUIT_Authentication_Block
]
SUIT_Authentication_Block /= COSE_Mac_Tagged
SUIT_Authentication_Block /= COSE_Sign_Tagged
SUIT_Authentication_Block /= COSE_Mac0_Tagged
SUIT_Authentication_Block /= COSE_Sign1_Tagged
Moran, et al. Expires 29 November 2025 [Page 30]
Internet-Draft CBOR-based SUIT Manifest May 2025
The SUIT_Digest is computed over the bstr-wrapped SUIT_Manifest that
is present in the SUIT_Envelope at the suit-manifest key. The
SUIT_Digest MUST always be present. The Manifest Processor requires
a SUIT_Authentication_Block to be present. The manifest MUST be
protected from tampering between the time of creation and the time of
signing/MACing.
The SUIT_Authentication_Block is computed using detached payloads, as
described in RFC 9052 [RFC9052]. The detached payload in each case
is the bstr-wrapped SUIT_Digest at the beginning of the list.
Signers (or MAC calculators) MUST verify the SUIT_Digest prior to
performing the cryptographic computation to avoid "Time-of-check to
time-of-use" type of attack. When multiple
SUIT_Authentication_Blocks are present, then each
SUIT_Authentication_Block MUST be computed over the same SUIT_Digest
but using a different algorithm or signing/MAC authority. This
feature also allows to transition to new algorithms, such as post-
quantum cryptography (PQC) algorithms.
The SUIT_Authentication structure MUST come before the suit-manifest
element, regardless of canonical encoding of CBOR. The algorithms
used in SUIT_Authentication are defined by the profiles declared in
[I-D.ietf-suit-mti].
8.4. Manifest
The manifest contains:
* a version number (see Section 8.4.1)
* a sequence number (see Section 8.4.2)
* a reference URI (see Section 8.4.3)
* a common structure with information that is shared between command
sequences (see Section 8.4.5)
* one or more lists of commands that the Recipient should perform
(see Section 8.4.6)
* a reference to the full manifest (see Section 8.4.3)
* human-readable text describing the manifest found in the
SUIT_Envelope (see Section 8.4.4)
The Text section, or any Command Sequence of the Update Procedure
(Image Fetch, Image Installation and, System Validation) can be
either a CBOR structure or a SUIT_Digest. In each of these cases,
Moran, et al. Expires 29 November 2025 [Page 31]
Internet-Draft CBOR-based SUIT Manifest May 2025
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 8.4.12 for more detail.
8.4.1. 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.
8.4.2. suit-manifest-sequence-number
The suit-manifest-sequence-number is a monotonically increasing anti-
rollback counter. 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.
8.4.3. suit-reference-uri
suit-reference-uri is 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. This document is only concerned with
the transport of a URI which is intended for machine readable uses,
not human readable uses. The encoding is the same as CBOR Tag 32,
however the tag is omitted because it is implied by context.
8.4.4. suit-text
suit-text SHOULD be a severable element. suit-text is a map of
language identifiers (identical to Tag38 of RFC9290, Appendix A) to
language-specific text maps. Each language-specific text map is a
map containing two different types of pair:
* integer => text
* SUIT_Component_Identifier => map
The SUIT_Text_Map is defined in the following CDDL.
Moran, et al. Expires 29 November 2025 [Page 32]
Internet-Draft CBOR-based SUIT Manifest May 2025
tag38-ltag = text .regexp "[a-zA-Z]{1,8}(-[a-zA-Z0-9]{1,8})*"
SUIT_Text_Map = {
+ tag38-ltag => SUIT_Text_LMap
}
SUIT_Text_LMap = {
SUIT_Text_Keys,
* SUIT_Component_Identifier => {
SUIT_Text_Component_Keys
}
}
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 8.4.5).
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-formatted document |
| | [YAML] that was used to |
| | create the manifest |
+--------------------------------+----------------------------------+
Table 3
Moran, et al. Expires 29 November 2025 [Page 33]
Internet-Draft CBOR-based SUIT Manifest May 2025
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 (see |
| | Section 8.4.8.2) |
+---------------------------------+-------------------------------+
| suit-text-model-info | The information used to |
| | create the class-id condition |
| | (see Section 8.4.8.2) |
+---------------------------------+-------------------------------+
| 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 |
+---------------------------------+-------------------------------+
Table 4
suit-text is OPTIONAL to implement.
8.4.5. suit-common
suit-common encodes all the information that is shared between each
of the command sequences, including: suit-components, and suit-
shared-sequence. suit-common is REQUIRED to implement.
suit-components is a list of SUIT_Component_Identifier
(Section 8.4.5.1) blocks that specify the component identifiers that
will be affected by the content of the current manifest. suit-
components is REQUIRED to implement.
Moran, et al. Expires 29 November 2025 [Page 34]
Internet-Draft CBOR-based SUIT Manifest May 2025
suit-shared-sequence is a SUIT_Command_Sequence to execute prior to
executing any other command sequence. Typical actions in suit-
shared-sequence include setting expected Recipient identity and image
digests when they are conditional (see Section 8.4.10.2 and
Section 7.7 for more information on conditional sequences). suit-
shared-sequence is RECOMMENDED to implement. Whenever a parameter or
Try Each command is required by more than one Command Sequence,
placing that parameter or command in suit-shared-sequence results in
a smaller encoding.
8.4.5.1. 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. 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.
8.4.6. 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. 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 because
it is not relevant in all bootloaders.
2. 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.
Moran, et al. Expires 29 November 2025 [Page 35]
Internet-Draft CBOR-based SUIT Manifest May 2025
3. 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.
suit-validate is REQUIRED to implement.
4. 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.
5. Invoke or Boot: suit-invoke is a SUIT_Command_Sequence to execute
in order to invoke an image. suit-invoke typically contains a
single instruction: the "invoke" directive, but may also contain
an image condition. suit-invoke is OPTIONAL to implement because
it not needed for restart-based invocation.
Goals 1,2,3 form the Update Procedure. Goals 3,4,5 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 8.4.7)
Each directive is composed of:
1. A command code identifier
2. An argument block or a SUIT_Reporting_Policy (Section 8.4.7)
Argument blocks are consumed only by flow-control directives:
* Set Component Index
* Set/Override Parameters
Moran, et al. Expires 29 November 2025 [Page 36]
Internet-Draft CBOR-based SUIT Manifest May 2025
* 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. This index is a numeric index
into the Component Identifier table defined at the beginning of the
manifest.
To facilitate optional conditions, a special directive, suit-
directive-try-each (Section 8.4.10.2), 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 8.4.8.15).
8.4.7. 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 |
+-----------------------------+----------------------------------+
Table 5
Any or all of these policies may be enabled at once.
Moran, et al. Expires 29 November 2025 [Page 37]
Internet-Draft CBOR-based SUIT Manifest May 2025
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
The Reporting Engine consumes these information elements and decides
whether to generate an entry in its report output and which
information elements to include based on its internal policy
decisions. The Reporting Engine uses the reporting policy provided
to it by the SUIT Manifest Processor as a set of hints but MAY choose
to ignore these hints and apply its own policy instead.
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 set of information elements for each Component, in
the order expressed in the Components list or the Component Index
array.
This specification does not define a particular format of Records or
Reports. This specification only defines hints to the Reporting
Engine for which information elements it should aggregate into the
Report.
When used in a Invocation Procedure, the output of the Reporting
Engine 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.
8.4.8. 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 reuse of parameters between commands,
thus reducing manifest size.
Moran, et al. Expires 29 November 2025 [Page 38]
Internet-Draft CBOR-based SUIT Manifest May 2025
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.
Moran, et al. Expires 29 November 2025 [Page 39]
Internet-Draft CBOR-based SUIT Manifest May 2025
+==============+==================================+=================+
| Name | CDDL Structure | Reference |
+==============+==================================+=================+
| Vendor ID | suit-parameter-vendor-identifier | Section 8.4.8.3 |
+--------------+----------------------------------+-----------------+
| Class ID | suit-parameter-class-identifier | Section 8.4.8.4 |
+--------------+----------------------------------+-----------------+
| Device ID | suit-parameter-device-identifier | Section 8.4.8.5 |
+--------------+----------------------------------+-----------------+
| Image | suit-parameter-image-digest | Section 8.4.8.6 |
| Digest | | |
+--------------+----------------------------------+-----------------+
| Image | suit-parameter-image-size | Section 8.4.8.7 |
| Size | | |
+--------------+----------------------------------+-----------------+
| Content | suit-parameter-content | Section 8.4.8.9 |
+--------------+----------------------------------+-----------------+
| Component | suit-parameter-component-slot | Section 8.4.8.8 |
| Slot | | |
+--------------+----------------------------------+-----------------+
| URI | suit-parameter-uri | Section |
| | | 8.4.8.10 |
+--------------+----------------------------------+-----------------+
| Source | suit-parameter-source-component | Section |
| Component | | 8.4.8.11 |
+--------------+----------------------------------+-----------------+
| Invoke | suit-parameter-invoke-args | Section |
| Args | | 8.4.8.12 |
+--------------+----------------------------------+-----------------+
| Fetch | suit-parameter-fetch-arguments | Section |
| Arguments | | 8.4.8.13 |
+--------------+----------------------------------+-----------------+
| Strict | suit-parameter-strict-order | Section |
| Order | | 8.4.8.14 |
+--------------+----------------------------------+-----------------+
| Soft | suit-parameter-soft-failure | Section |
| Failure | | 8.4.8.15 |
+--------------+----------------------------------+-----------------+
| Custom | suit-parameter-custom | Section |
| | | 8.4.8.16 |
+--------------+----------------------------------+-----------------+
Table 6
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
Moran, et al. Expires 29 November 2025 [Page 40]
Internet-Draft CBOR-based SUIT Manifest May 2025
division of responsibility within a pull parser. The same
consideration does not apply to Directives because those elements are
invoked with their arguments immediately.
8.4.8.1. CBOR PEN UUID Namespace Identifier
The CBOR PEN (Private Enterprise Number) UUID Namespace Identifier is
constructed as follows:
It uses the OID Namespace as a starting point, then uses the CBOR
absolute OID encoding for the IANA PEN OID (1.3.6.1.4.1):
D8 6F # tag(111)
45 # bytes(5)
# Absolute OID encoding of IANA Private Enterprise Number:
# 1.3. 6. 1. 4. 1
2B 06 01 04 01 # X.690 Clause 8.19
Computing a version 5 UUID from these produces:
NAMESPACE_CBOR_PEN = UUID5(NAMESPACE_OID, h'D86F452B06010401')
NAMESPACE_CBOR_PEN = 47fbdabb-f2e4-55f0-bb39-3620c2f6df4e
8.4.8.2. Constructing UUIDs
Several conditions use identifiers to determine whether a manifest
matches a given Recipient or not. These identifiers are defined to
be RFC 9562 [RFC9562] 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 8.4.9.1).
A more complete example: Imagine a device has the following physical
components: 1. A host Microcontroller 2. A Wi-Fi module
This same device has three software modules: 1. An operating system
2. A Wi-Fi module interface driver 3. An application
Moran, et al. Expires 29 November 2025 [Page 41]
Internet-Draft CBOR-based SUIT Manifest May 2025
Suppose that the Wi-Fi 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. Wi-Fi module model/revision
4. Application
This allows the OS, Wi-Fi 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 Wi-Fi module with an update, which is a very
powerful mechanism, particularly when used for security updates.
UUIDs MUST be created according to versions 3, 4, or 5 of [RFC9562].
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:
The "IANA UUID Namespace ID for DNS" is:
6ba7b810-9dad-11d1-80b4-00c04fd430c8
Vendor ID = UUID5(<IANA UUID Namespace ID DNS>, vendor domain name)
In this case, the vendor domain name is a UTF-8 encoded string.
Since UUID version 5 applies a digest, internationalization
considerations are not applied. The native UTF-8 domain name is
used.
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 8.4.8.3), the RECOMMENDED
method to create a Class ID is:
Class ID = UUID5(
UUID5(NAMESPACE_CBOR_PEN, CBOR_PEN),
Class-Specific-Information)
Moran, et al. Expires 29 November 2025 [Page 42]
Internet-Draft CBOR-based SUIT Manifest May 2025
Class-specific-information is composed of a variety of data, for
example:
* Model number.
* Hardware revision.
* Bootloader version (for immutable bootloaders).
8.4.8.3. 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 [RFC9562]
Private Enterprise Numbers are encoded as a relative OID, according
to the definition in [RFC9090]. All PENs are relative to the IANA
PEN: 1.3.6.1.4.1.
8.4.8.4. suit-parameter-class-identifier
A RFC 9562 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 8.4.8.2
8.4.8.5. suit-parameter-device-identifier
A RFC 9562 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 8.4.8.2
8.4.8.6. 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 8.4.8.
8.4.8.7. suit-parameter-image-size
The size of the firmware image in bytes. This size is encoded as a
positive integer.
Moran, et al. Expires 29 November 2025 [Page 43]
Internet-Draft CBOR-based SUIT Manifest May 2025
8.4.8.8. suit-parameter-component-slot
This parameter sets the 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 index
into the component's storage area. This slot MUST be encoded as a
positive integer.
8.4.8.9. suit-parameter-content
A block of raw data for use with Section 8.4.10.6. It contains a
byte string of data to be written to a specified component ID in the
same way as a fetch or a copy.
If data is encoded this way, it should be small, e.g., 10's of bytes.
Large payloads, e.g., 1000's of bytes, written via this method might
prevent the manifest from being held in memory during validation.
Typical applications include small configuration parameters.
The size of payload embedded in suit-parameter-content impacts the
security requirement defined in [RFC9124], Section 4.3.21
REQ.SEC.MFST.CONST: Manifest Kept Immutable between Check and Use.
Actual limitations on payload size for suit-parameter-content depend
on the application, in particular the available memory that satisfies
REQ.SEC.MFST.CONST. If the availability of tamper resistant memory
is less than the manifest size, then REQ.SEC.MFST.CONST cannot be
satisfied.
If suit-parameter-content is instantiated in a severable command
sequence, then this becomes functionally very similar to an
integrated payload, which may be a better choice.
8.4.8.10. suit-parameter-uri
A URI Reference [RFC3986] from which to fetch a resource. The
encoding is the same as CBOR Tag 32, however the tag is omitted
because it is implied by the context. This document is only
concerned with the transport of a URI which is intended for machine
readable uses, not human readable uses.
8.4.8.11. suit-parameter-source-component
This parameter sets the source component to be used with either suit-
directive-copy (Section 8.4.10.5) or with suit-directive-swap
(Section 8.4.10.9). The current Component, as set by suit-directive-
set-component-index defines the destination, and suit-parameter-
source-component defines the source.
Moran, et al. Expires 29 November 2025 [Page 44]
Internet-Draft CBOR-based SUIT Manifest May 2025
8.4.8.12. suit-parameter-invoke-args
This parameter contains an encoded set of arguments for suit-
directive-invoke (Section 8.4.10.7). The arguments MUST be provided
as an implementation-defined bstr.
8.4.8.13. suit-parameter-fetch-arguments
An implementation-defined set of arguments to suit-directive-fetch
(Section 8.4.10.4). Arguments are encoded in a bstr.
8.4.8.14. 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. 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.
8.4.8.15. suit-parameter-soft-failure
When executing a command sequence inside suit-directive-try-each
(Section 8.4.10.2) or suit-directive-run-sequence (Section 8.4.10.8)
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.
Moran, et al. Expires 29 November 2025 [Page 45]
Internet-Draft CBOR-based SUIT Manifest May 2025
suit-parameter-soft-failure is scoped to the enclosing
SUIT_Command_Sequence. Its value is discarded when the enclosing
SUIT_Command_Sequence terminates and suit-parameter-soft-failure
reverts to the value it had prior to the invocation of the
SUIT_Command_Sequence. Nested SUIT_Command_Sequences do not inherit
the enclosing sequence's suit-parameter-soft-failure. It MUST NOT be
set outside of suit-directive-try-each or suit-directive-run-
sequence, modifying suit-parameter-soft-failure outside of these
circumstances causes an Abort.
When suit-directive-try-each is invoked, Soft Failure defaults to
True in every SUIT_Command_Sequence in the suit-directive-try-each
argument. 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 the enclosing SUIT_Command_Sequence terminates, suit-parameter-
soft-failure reverts to the value it held before the
SUIT_Command_Sequence was invoked.
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.
8.4.8.16. suit-parameter-custom
This parameter is an extension point for any proprietary, application
specific conditions and directives. It MUST NOT be used in the
shared sequence. This effectively scopes each custom command to a
particular Vendor Identifier/Class Identifier pair.
suit-parameter-custom MAY be consumed by any command, in an
application-specific way, however if a suit-parameter-custom is
absent, then all standardised suit-commands MUST execute correctly.
In this respect, suit-parameter-custom MUST be treated as a hint by
any standardised suit-command that consumes it.
8.4.9. 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 8.4.7. Conditions include:
Moran, et al. Expires 29 November 2025 [Page 46]
Internet-Draft CBOR-based SUIT Manifest May 2025
+===================+==================================+===========+
| Name | CDDL Structure | Reference |
+===================+==================================+===========+
| Vendor Identifier | suit-condition-vendor-identifier | Section |
| | | 8.4.9.1 |
+-------------------+----------------------------------+-----------+
| Class Identifier | suit-condition-class-identifier | Section |
| | | 8.4.9.1 |
+-------------------+----------------------------------+-----------+
| Device Identifier | suit-condition-device-identifier | Section |
| | | 8.4.9.1 |
+-------------------+----------------------------------+-----------+
| Image Match | suit-condition-image-match | Section |
| | | 8.4.9.2 |
+-------------------+----------------------------------+-----------+
| Check Content | suit-condition-check-content | Section |
| | | 8.4.9.3 |
+-------------------+----------------------------------+-----------+
| Component Slot | suit-condition-component-slot | Section |
| | | 8.4.9.4 |
+-------------------+----------------------------------+-----------+
| Abort | suit-condition-abort | Section |
| | | 8.4.9.5 |
+-------------------+----------------------------------+-----------+
| Custom Condition | suit-command-custom | Section |
| | | 8.4.11 |
+-------------------+----------------------------------+-----------+
Table 7
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
Moran, et al. Expires 29 November 2025 [Page 47]
Internet-Draft CBOR-based SUIT Manifest May 2025
executing if suit-parameter-soft-failure (Section 8.4.8.15) 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 greater than or equal to -256 are reserved for IANA
registration while those lesser than -256 are custom conditions
reserved for proprietary definition by the author of a manifest
processor. See Section 11 for more details.
8.4.9.1. 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 UUID [RFC9562]
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.
8.4.9.2. suit-condition-image-match
Verify that the current component matches the suit-parameter-image-
digest (Section 8.4.8.6) 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.
Moran, et al. Expires 29 November 2025 [Page 48]
Internet-Draft CBOR-based SUIT Manifest May 2025
8.4.9.3. suit-condition-check-content
This directive compares the specified component identifier to the
data indicated by suit-parameter-content. This functions similarly
to suit-condition-image-match, however it does a direct, byte-by-byte
comparison rather than a digest-based comparison. Because it is
possible that an early stop to check-content could reveal information
through timing, suit-condition-check-content MUST be constant time:
no early exits.
The following pseudo-code described an example content checking
algorithm:
// content & component must be same length
// returns 0 for match
int check_content(content, component, length) {
int residual = 0;
for (i = 0; i < length; i++) {
residual |= content[i] ^ component[i];
}
return residual;
}
8.4.9.4. suit-condition-component-slot
Verify that the slot index of the current component matches the slot
index set in suit-parameter-component-slot (Section 8.4.8.8). This
condition allows a manifest to select between several images to match
a target slot.
8.4.9.5. suit-condition-abort
Unconditionally fail. This operation is typically used in
conjunction with suit-directive-try-each (Section 8.4.10.2).
8.4.10. SUIT_Directive
Directives are used to define the behavior of the recipient.
Directives include:
Moran, et al. Expires 29 November 2025 [Page 49]
Internet-Draft CBOR-based SUIT Manifest May 2025
+===============+====================================+===========+
| Name | CDDL Structure | Reference |
+===============+====================================+===========+
| Set Component | suit-directive-set-component-index | Section |
| Index | | 8.4.10.1 |
+---------------+------------------------------------+-----------+
| Try Each | suit-directive-try-each | Section |
| | | 8.4.10.2 |
+---------------+------------------------------------+-----------+
| Override | suit-directive-override-parameters | Section |
| Parameters | | 8.4.10.3 |
+---------------+------------------------------------+-----------+
| Fetch | suit-directive-fetch | Section |
| | | 8.4.10.4 |
+---------------+------------------------------------+-----------+
| Copy | suit-directive-copy | Section |
| | | 8.4.10.5 |
+---------------+------------------------------------+-----------+
| Write | suit-directive-write | Section |
| | | 8.4.10.6 |
+---------------+------------------------------------+-----------+
| Invoke | suit-directive-invoke | Section |
| | | 8.4.10.7 |
+---------------+------------------------------------+-----------+
| Run Sequence | suit-directive-run-sequence | Section |
| | | 8.4.10.8 |
+---------------+------------------------------------+-----------+
| Swap | suit-directive-swap | Section |
| | | 8.4.10.9 |
+---------------+------------------------------------+-----------+
| Custom | suit-command-custom | Section |
| Directive | | 8.4.11 |
+---------------+------------------------------------+-----------+
Table 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.
8.4.10.1. suit-directive-set-component-index
Set Component Index defines the component to which successive
directives and conditions will apply. The Set Component Index
arguments are described in Section 6.5.
Moran, et al. Expires 29 November 2025 [Page 50]
Internet-Draft CBOR-based SUIT Manifest May 2025
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.
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.
8.4.10.2. suit-directive-try-each
This command runs several SUIT_Command_Sequence instances, one after
another, in a strict order, until one succeeds or the list is
exhausted. Use this command to implement a "try/catch-try/catch"
sequence. Manifest processors MAY implement this command.
suit-parameter-soft-failure (Section 8.4.8.15) 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.
8.4.10.3. 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 8.4.8.
suit-directive-override-parameters does not specify a reporting
policy.
Moran, et al. Expires 29 November 2025 [Page 51]
Internet-Draft CBOR-based SUIT Manifest May 2025
8.4.10.4. 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 payloads. suit-directive-
fetch retrieves each component listed in component-index. If
component-index is True, instead of an integer, then all current
manifest components are fetched. If component-index is an array,
then all listed components are fetched.
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 size and digest of the payload to be fetched are typically set
prior to the invokation of suit-directive-fetch. If both suit-
parameter-image-digest and suit-parameter-image-size are set for the
current component when suit-directive-fetch is invoked, the Manifest
Processor MAY choose to optimize the fetch by:
* Checking if the target component matches the digest supplied
before fetching.
* Checking if another component matches the digest supplied before
fetching.
The exact mechanisms of these optimizations are implementation
defined.
8.4.10.5. 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.
suit-directive-copy reads its source from suit-parameter-source-
component (Section 8.4.8.11).
If either the source component parameter or the source component
itself is absent, this command fails.
Moran, et al. Expires 29 November 2025 [Page 52]
Internet-Draft CBOR-based SUIT Manifest May 2025
The size and digest of the payload to be fetched are typically set
prior to the invokation of suit-directive-copy. If both suit-
parameter-image-digest and suit-parameter-image-size are set for the
current component when suit-directive-copy is invoked, the Manifest
Processor MAY choose to optimize the copy by:
* Checking if the target component matches the digest supplied
before copying.
* Checking if the source component matches the digest supplied
before copying.
The first optimization avoids a copy operation when the data is the
same. The second optimization avoids a copy of a corrupted image.
The exact mechanisms of these optimizations are implementation
defined.
8.4.10.6. suit-directive-write
This directive writes a small block of data, specified in
Section 8.4.8.9, to a component.
Encoding Considerations: Careful consideration must be taken to
determine whether it is more appropriate to use an integrated payload
or to use Section 8.4.8.9 for a particular application. While the
encoding of suit-directive-write is smaller than an integrated
payload, a large suit-parameter-content payload may prevent the
manifest processor from holding the command sequence in memory while
executing it.
8.4.10.7. suit-directive-invoke
suit-directive-invoke 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-invoke
through suit-parameter-invoke-arguments (Section 8.4.8.12) 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.
Moran, et al. Expires 29 November 2025 [Page 53]
Internet-Draft CBOR-based SUIT Manifest May 2025
8.4.10.8. 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. This
also allows a sequence of instructions to be iterated over, once for
each current component index, when component-index = true or
component-index = list. See Section 6.5.
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 8.4.8.15) defaults to False when
suit-directive-run-sequence begins. Its value is discarded when
suit-directive-run-sequence terminates.
8.4.10.9. 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.
8.4.11. suit-command-custom
suit-command-custom identifies an experimental, proprietary, or
application-specific condition or directive. The associated value is
an integer less than –256, selected by the firmware developer from
the Private Use address range defined for the respective registry.
If additional information must be provided, it should be encoded in a
custom parameter (as described in Section 8.4.8). Any number of
custom commands is permitted. SUIT_Command_Custom is OPTIONAL to
implement.
Moran, et al. Expires 29 November 2025 [Page 54]
Internet-Draft CBOR-based SUIT Manifest May 2025
8.4.12. Integrity Check Values
When the 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 8.6.
8.5. 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 8.4.8.2 | REQUIRED |
+-------------------+-----------------+----------------+
| Class Identifier | Section 8.4.8.2 | REQUIRED |
+-------------------+-----------------+----------------+
| Device Identifier | Section 8.4.8.2 | OPTIONAL |
+-------------------+-----------------+----------------+
| Image Match | Section 8.4.9.2 | REQUIRED |
+-------------------+-----------------+----------------+
| Check Content | Section 8.4.9.3 | OPTIONAL |
+-------------------+-----------------+----------------+
| Component Slot | Section 8.4.9.4 | OPTIONAL |
+-------------------+-----------------+----------------+
| Abort | Section 8.4.9.5 | OPTIONAL |
+-------------------+-----------------+----------------+
| Custom Condition | Section 8.4.11 | OPTIONAL |
+-------------------+-----------------+----------------+
Table 9
The subsequent table shows the directives.
Moran, et al. Expires 29 November 2025 [Page 55]
Internet-Draft CBOR-based SUIT Manifest May 2025
+=====================+==================+====================+
| Name | Reference | Implementation |
+=====================+==================+====================+
| Set Component Index | Section 8.4.10.1 | REQUIRED if more |
| | | than one component |
+---------------------+------------------+--------------------+
| Write Content | Section 8.4.10.6 | OPTIONAL |
+---------------------+------------------+--------------------+
| Try Each | Section 8.4.10.2 | OPTIONAL |
+---------------------+------------------+--------------------+
| Override Parameters | Section 8.4.10.3 | REQUIRED |
+---------------------+------------------+--------------------+
| Fetch | Section 8.4.10.4 | REQUIRED for |
| | | Updater |
+---------------------+------------------+--------------------+
| Copy | Section 8.4.10.5 | OPTIONAL |
+---------------------+------------------+--------------------+
| Invoke | Section 8.4.10.7 | REQUIRED for |
| | | Bootloader |
+---------------------+------------------+--------------------+
| Run Sequence | Section 8.4.10.8 | OPTIONAL |
+---------------------+------------------+--------------------+
| Swap | Section 8.4.10.9 | OPTIONAL |
+---------------------+------------------+--------------------+
Table 10
The subsequent table shows the parameters.
Moran, et al. Expires 29 November 2025 [Page 56]
Internet-Draft CBOR-based SUIT Manifest May 2025
+==================+==================+======================+
| Name | Reference | Implementation |
+==================+==================+======================+
| Vendor ID | Section 8.4.8.3 | REQUIRED |
+------------------+------------------+----------------------+
| Class ID | Section 8.4.8.4 | REQUIRED |
+------------------+------------------+----------------------+
| Image Digest | Section 8.4.8.6 | REQUIRED |
+------------------+------------------+----------------------+
| Image Size | Section 8.4.8.7 | REQUIRED |
+------------------+------------------+----------------------+
| Component Slot | Section 8.4.8.8 | OPTIONAL |
+------------------+------------------+----------------------+
| Content | Section 8.4.8.9 | OPTIONAL |
+------------------+------------------+----------------------+
| URI | Section 8.4.8.10 | REQUIRED for Updater |
+------------------+------------------+----------------------+
| Source Component | Section 8.4.8.11 | OPTIONAL |
+------------------+------------------+----------------------+
| Invoke Args | Section 8.4.8.12 | OPTIONAL |
+------------------+------------------+----------------------+
| Device ID | Section 8.4.8.5 | OPTIONAL |
+------------------+------------------+----------------------+
| Strict Order | Section 8.4.8.14 | OPTIONAL |
+------------------+------------------+----------------------+
| Soft Failure | Section 8.4.8.15 | OPTIONAL |
+------------------+------------------+----------------------+
| Custom | Section 8.4.8.16 | OPTIONAL |
+------------------+------------------+----------------------+
Table 11
8.6. 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.
Moran, et al. Expires 29 November 2025 [Page 57]
Internet-Draft CBOR-based SUIT Manifest May 2025
At time of manifest creation, the Author MAY chose to make a manifest
element severable by removing it from the manifest, encoding it in a
bstr, and placing a SUIT_Digest of the bstr in the manifest so that
it can still be authenticated. Making an element severable changes
the digest of the manifest, so the signature MUST be computed after
manifest elements are made severable. Only Manifest Elements with
corresponding elements in the SUIT_Envelope can be made severable
(see Section 11.1 for SUIT_Envelope elements). 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
SUIT Manifest Processors are RECOMMENDED to use one of the following
models for managing permissions in the manifest.
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.
Moran, et al. Expires 29 November 2025 [Page 58]
Internet-Draft CBOR-based SUIT Manifest May 2025
10. SUIT Digest Container
The SUIT digest is a CBOR array containing two elements: an algorithm
identifier and a bstr containing the bytes of the digest. Some forms
of digest may require additional parameters. These can be added
following the digest.
The values of the algorithm identifier are found in the IANA "COSE
Algorithms" registry [COSE-Alg], which was created by [RFC9054].
SHA-256 (-16) MUST be implemented by all Manifest Processors.
Any other algorithm defined in the IANA "COSE Algorithms" registry,
such as SHA-512 (-44), MAY be implemented in a Manifest Processor.
11. IANA Considerations
IANA is requested to register the following CBOR Tags:
* Tag: 107
* Data Item: map
* Semantics: SUIT_Envelope as defined in Appendix A
* Reference: [this RFC]
* Tag: 1070
* Data Item: map
* Semantics: SUIT_Manifest as defined in Appendix A
* Reference: [this RFC]
Additionally, IANA is requested to register:
* allocate CBOR tag 107 (suggested) in the "CBOR Tags" registry for
the SUIT Envelope. The CBOR Tag's Data Item is a SUIT_Envelope as
defined in Appendix A
* allocate CBOR tag 1070 (suggested) in the "CBOR Tags" registry for
the SUIT Manifest. The CBOR Tag's Data Item is a SUIT_Manifest as
defined in Appendix A
* allocate media type application/suit-envelope+cose in the "Media
Types" registry, see below.
Moran, et al. Expires 29 November 2025 [Page 59]
Internet-Draft CBOR-based SUIT Manifest May 2025
* allocate Namespace CBOR PEN in the "UUID Namespace IDs" registry
with value 47fbdabb-f2e4-55f0-bb39-3620c2f6df4e, as defined in
Section 8.4.8.1
* setup several registries as described below.
IANA is requested to create a new category for Software Update for
the Internet of Things (SUIT) and a page within this category for
SUIT manifests.
IANA is also requested to create several registries defined in the
subsections below.
For each registry, the number space is partitioned, with each range
governed by a different allocation policy:
* Values 256 and above are subject to Specification Required,
* Values in the range 0 to 255 follow a Standards Action policy,
* Values from –255 to 0 are also governed by Standards Action, and
* Values –256 and below are designated for Private Use (also
referred to as custom values).
New entries to those registries need to provide a label, a name and a
reference to a specification that describes the functionality. More
guidance on the expert review can be found below.
11.1. SUIT Envelope Elements
IANA is requested to create a new registry for SUIT envelope
elements.
Moran, et al. Expires 29 November 2025 [Page 60]
Internet-Draft CBOR-based SUIT Manifest May 2025
+============+=================+======================+
| Label | Name | Reference |
+============+=================+======================+
| -255 to -1 | Unassigned | |
+------------+-----------------+----------------------+
| 0 | Unset Detection | Section 8.1 of [TBD: |
| | | this document] |
+------------+-----------------+----------------------+
| 1 | Reserved | Appendix C.1 of |
| | (Delegation) | [TBD: this document] |
+------------+-----------------+----------------------+
| 2 | Authentication | Section 8.3 of [TBD: |
| | Wrapper | this document] |
+------------+-----------------+----------------------+
| 3 | Manifest | Section 8.4 of [TBD: |
| | | this document] |
+------------+-----------------+----------------------+
| 4 to 15 | Unassigned | |
+------------+-----------------+----------------------+
| 16 | Payload Fetch | Section 8.4.6 of |
| | | [TBD: this document] |
+------------+-----------------+----------------------+
| 17 to 19 | Unassigned | |
+------------+-----------------+----------------------+
| 20 | Payload | Section 8.4.6 of |
| | Installation | [TBD: this document] |
+------------+-----------------+----------------------+
| 21 to 22 | Unassigned | |
+------------+-----------------+----------------------+
| 23 | Text | Section 8.4.4 of |
| | Description | [TBD: this document] |
+------------+-----------------+----------------------+
Table 12
11.2. SUIT Manifest Elements
IANA is requested to create a new registry for SUIT manifest
elements.
+============+=================+======================+
| Label | Name | Reference |
+============+=================+======================+
| -255 to -1 | Unassigned | |
+------------+-----------------+----------------------+
| 0 | Unset Detection | Section 8.1 of [TBD: |
| | | this document] |
+------------+-----------------+----------------------+
Moran, et al. Expires 29 November 2025 [Page 61]
Internet-Draft CBOR-based SUIT Manifest May 2025
| 1 | Encoding | Section 8.4.1 of |
| | Version | [TBD: this document] |
+------------+-----------------+----------------------+
| 2 | Sequence Number | Section 8.4.2 of |
| | | [TBD: this document] |
+------------+-----------------+----------------------+
| 3 | Common Data | Section 8.4.5 of |
| | | [TBD: this document] |
+------------+-----------------+----------------------+
| 4 | Reference URI | Section 8.4.3 of |
| | | [TBD: this document] |
+------------+-----------------+----------------------+
| 5 to 6 | Unassigned | |
+------------+-----------------+----------------------+
| 7 | Image | Section 8.4.6 of |
| | Validation | [TBD: this document] |
+------------+-----------------+----------------------+
| 8 | Image Loading | Section 8.4.6 of |
| | | [TBD: this document] |
+------------+-----------------+----------------------+
| 9 | Image | Section 8.4.6 of |
| | Invocation | [TBD: this document] |
+------------+-----------------+----------------------+
| 10 to 15 | Unassigned | |
+------------+-----------------+----------------------+
| 16 | Payload Fetch | Section 8.4.6 of |
| | | [TBD: this document] |
+------------+-----------------+----------------------+
| 17 to 19 | Unassigned | |
+------------+-----------------+----------------------+
| 20 | Payload | Section 8.4.6 of |
| | Installation | [TBD: this document] |
+------------+-----------------+----------------------+
| 21 to 22 | Unassigned | |
+------------+-----------------+----------------------+
| 23 | Text | Section 8.4.4 of |
| | Description | [TBD: this document] |
+------------+-----------------+----------------------+
Table 13
11.3. SUIT Common Elements
IANA is requested to create a new registry for SUIT common elements.
Moran, et al. Expires 29 November 2025 [Page 62]
Internet-Draft CBOR-based SUIT Manifest May 2025
+============+=================+======================+
| Label | Name | Reference |
+============+=================+======================+
| -255 to -1 | Unassigned | |
+------------+-----------------+----------------------+
| 0 | Unset Detection | Section 8.1 of [TBD: |
| | | this document] |
+------------+-----------------+----------------------+
| 1 | Unassigned | |
+------------+-----------------+----------------------+
| 2 | Component | Section 8.4.5 of |
| | Identifiers | [TBD: this document] |
+------------+-----------------+----------------------+
| 3 | Unassigned | |
+------------+-----------------+----------------------+
| 4 | Common Command | Section 8.4.5 of |
| | Sequence | [TBD: this document] |
+------------+-----------------+----------------------+
Table 14
11.4. SUIT Commands
IANA is requested to create a new registry for SUIT commands.
+============+=================+======================+
| Label | Name | Reference |
+============+=================+======================+
| -255 to -1 | Unassigned | |
+------------+-----------------+----------------------+
| 0 | Unset Detection | Section 8.1 of [TBD: |
| | | this document] |
+------------+-----------------+----------------------+
| 1 | Vendor | Section 8.4.9.1 of |
| | Identifier | [TBD: this document] |
+------------+-----------------+----------------------+
| 2 | Class | Section 8.4.9.1 of |
| | Identifier | [TBD: this document] |
+------------+-----------------+----------------------+
| 3 | Image Match | Section 8.4.9.2 of |
| | | [TBD: this document] |
+------------+-----------------+----------------------+
| 4 | Unassigned | |
+------------+-----------------+----------------------+
| 5 | Component Slot | Section 8.4.9.4 of |
| | | [TBD: this document] |
+------------+-----------------+----------------------+
| 6 | Check Content | Section 8.4.9.3 of |
Moran, et al. Expires 29 November 2025 [Page 63]
Internet-Draft CBOR-based SUIT Manifest May 2025
| | | [TBD: this document] |
+------------+-----------------+----------------------+
| 7 to 11 | Unassigned | |
+------------+-----------------+----------------------+
| 12 | Set Component | Section 8.4.10.1 of |
| | Index | [TBD: this document] |
+------------+-----------------+----------------------+
| 13 | Unassigned | |
+------------+-----------------+----------------------+
| 14 | Abort | Section 8.4.9.5 of |
| | | [TBD: this document] |
+------------+-----------------+----------------------+
| 15 | Try Each | Section 8.4.10.2 of |
| | | [TBD: this document] |
+------------+-----------------+----------------------+
| 16 to 17 | Unassigned | |
+------------+-----------------+----------------------+
| 18 | Write Content | Section 8.4.10.6 of |
| | | [TBD: this document] |
+------------+-----------------+----------------------+
| 19 | Unassigned | |
+------------+-----------------+----------------------+
| 20 | Override | Section 8.4.10.3 of |
| | Parameters | [TBD: this document] |
+------------+-----------------+----------------------+
| 21 | Fetch | Section 8.4.10.4 of |
| | | [TBD: this document] |
+------------+-----------------+----------------------+
| 22 | Copy | Section 8.4.10.5 of |
| | | [TBD: this document] |
+------------+-----------------+----------------------+
| 23 | Invoke | Section 8.4.10.7 of |
| | | [TBD: this document] |
+------------+-----------------+----------------------+
| 24 | Device | Section 8.4.9.1 of |
| | Identifier | [TBD: this document] |
+------------+-----------------+----------------------+
| 25 to 30 | Unassigned | |
+------------+-----------------+----------------------+
| 31 | Swap | Section 8.4.10.9 of |
| | | [TBD: this document] |
+------------+-----------------+----------------------+
| 32 | Run Sequence | Section 8.4.10.8 of |
| | | [TBD: this document] |
+------------+-----------------+----------------------+
Table 15
Moran, et al. Expires 29 November 2025 [Page 64]
Internet-Draft CBOR-based SUIT Manifest May 2025
11.5. SUIT Parameters
IANA is requested to create a new registry for SUIT parameters.
+============+=================+======================+
| Label | Name | Reference |
+============+=================+======================+
| -255 to -1 | Unassigned | |
+------------+-----------------+----------------------+
| 0 | Unset Detection | Section 8.1 of [TBD: |
| | | this document] |
+------------+-----------------+----------------------+
| 1 | Vendor ID | Section 8.4.8.3 of |
| | | [TBD: this document] |
+------------+-----------------+----------------------+
| 2 | Class ID | Section 8.4.8.4 of |
| | | [TBD: this document] |
+------------+-----------------+----------------------+
| 3 | Image Digest | Section 8.4.8.6 of |
| | | [TBD: this document] |
+------------+-----------------+----------------------+
| 4 | Unassigned | |
+------------+-----------------+----------------------+
| 5 | Component Slot | Section 8.4.8.8 of |
| | | [TBD: this document] |
+------------+-----------------+----------------------+
| 6 to 11 | Unassigned | |
+------------+-----------------+----------------------+
| 12 | Strict Order | Section 8.4.8.14 of |
| | | [TBD: this document] |
+------------+-----------------+----------------------+
| 13 | Soft Failure | Section 8.4.8.15 of |
| | | [TBD: this document] |
+------------+-----------------+----------------------+
| 14 | Image Size | Section 8.4.8.7 of |
| | | [TBD: this document] |
+------------+-----------------+----------------------+
| 15 to 17 | Unassigned | |
+------------+-----------------+----------------------+
| 18 | Content | Section 8.4.8.9 of |
| | | [TBD: this document] |
+------------+-----------------+----------------------+
| 19 to 20 | Unassigned | |
+------------+-----------------+----------------------+
| 21 | URI | Section 8.4.8.10 of |
| | | [TBD: this document] |
+------------+-----------------+----------------------+
| 22 | Source | Section 8.4.8.11 of |
Moran, et al. Expires 29 November 2025 [Page 65]
Internet-Draft CBOR-based SUIT Manifest May 2025
| | Component | [TBD: this document] |
+------------+-----------------+----------------------+
| 23 | Invoke Args | Section 8.4.8.12 of |
| | | [TBD: this document] |
+------------+-----------------+----------------------+
| 24 | Device ID | Section 8.4.8.5 of |
| | | [TBD: this document] |
+------------+-----------------+----------------------+
Table 16
11.6. SUIT Text Values
IANA is requested to create a new registry for SUIT text values.
+============+=================+======================+
| Label | Name | Reference |
+============+=================+======================+
| -255 to -1 | Unassigned | |
+------------+-----------------+----------------------+
| 0 | Unset Detection | Section 8.1 of [TBD: |
| | | this document] |
+------------+-----------------+----------------------+
| 1 | Manifest | Section 8.4.4 of |
| | Description | [TBD: this document] |
+------------+-----------------+----------------------+
| 2 | Update | Section 8.4.4 of |
| | Description | [TBD: this document] |
+------------+-----------------+----------------------+
| 3 | Manifest JSON | Section 8.4.4 of |
| | Source | [TBD: this document] |
+------------+-----------------+----------------------+
| 4 | Manifest YAML | Section 8.4.4 of |
| | Source | [TBD: this document] |
+------------+-----------------+----------------------+
Table 17
11.7. SUIT Component Text Values
IANA is requested to create a new registry for SUIT component text
values.
Moran, et al. Expires 29 November 2025 [Page 66]
Internet-Draft CBOR-based SUIT Manifest May 2025
+============+=================+======================+
| Label | Name | Reference |
+============+=================+======================+
| -255 to -1 | Unassigned | |
+------------+-----------------+----------------------+
| 0 | Unset Detection | Section 8.1 of [TBD: |
| | | this document] |
+------------+-----------------+----------------------+
| 1 | Vendor Name | Section 8.4.4 of |
| | | [TBD: this document] |
+------------+-----------------+----------------------+
| 2 | Model Name | Section 8.4.4 of |
| | | [TBD: this document] |
+------------+-----------------+----------------------+
| 3 | Vendor Domain | Section 8.4.4 of |
| | | [TBD: this document] |
+------------+-----------------+----------------------+
| 4 | Model Info | Section 8.4.4 of |
| | | [TBD: this document] |
+------------+-----------------+----------------------+
| 5 | Component | Section 8.4.4 of |
| | Description | [TBD: this document] |
+------------+-----------------+----------------------+
| 6 | Component | Section 8.4.4 of |
| | Version | [TBD: this document] |
+------------+-----------------+----------------------+
Table 18
11.8. Expert Review Instructions
The IANA registries established in this document allow values to be
added based on expert review. This section gives some general
guidelines for what the experts should be looking for, but they are
being designated as experts for a reason, so they should be given
substantial latitude.
Expert reviewers should take into consideration the following points:
* Point squatting should be discouraged. Reviewers are encouraged
to get sufficient information for registration requests to ensure
that the usage is not going to duplicate one that is already
registered, and that the point is likely to be used in
deployments. The zones tagged as private use are intended for
testing purposes and closed environments; code points in other
ranges should not be assigned for testing.
Moran, et al. Expires 29 November 2025 [Page 67]
Internet-Draft CBOR-based SUIT Manifest May 2025
* Specifications are required for the standards track range of point
assignment. Specifications should exist for all other ranges, but
early assignment before a specification is available is considered
to be permissible. When specifications are not provided, the
description provided needs to have sufficient information to
identify what the point is being used for.
* Experts should take into account the expected usage of fields when
approving point assignment. The fact that there is a range for
standards track documents does not mean that a standards track
document cannot have points assigned outside of that range. The
length of the encoded value should be weighed against how many
code points of that length are left, the size of device it will be
used on, and the number of code points left that encode to that
size.
* Key assignments in the SUIT Parameters table, particularly those
that encode to 1 CBOR byte (-24 to 23) should be reserved for SUIT
Directives that match the same key value.
11.9. Media Type Registration
This section registers the 'application/suit-envelope+cose' media
type in the "Media Types" registry. This media type are used to
indicate that the content is a SUIT envelope.
Moran, et al. Expires 29 November 2025 [Page 68]
Internet-Draft CBOR-based SUIT Manifest May 2025
Type name: application
Subtype name: suit-envelope+cose
Required parameters: N/A
Optional parameters: N/A
Encoding considerations: binary
Security considerations: See the Security Considerations section
of [[This RFC]].
Interoperability considerations: N/A
Published specification: [[This RFC]]
Applications that use this media type: Primarily used for
Firmware and software updates although the content may
also contain configuration data and other information
related to software and firmware.
Fragment identifier considerations: N/A
Additional information:
* Deprecated alias names for this type: N/A
* Magic number(s): N/A
* File extension(s): cbor, suit
* Macintosh file type code(s): N/A
Person & email address to contact for further information:
iesg@ietf.org
Intended usage: COMMON
Restrictions on usage: N/A
Author: Brendan Moran, <brendan.moran.ietf@gmail.com>
Change Controller: IETF
Provisional registration? No
Moran, et al. Expires 29 November 2025 [Page 69]
Internet-Draft CBOR-based SUIT Manifest May 2025
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 [RFC9019] and in the information model [RFC9124]
documents.
The security requirements outlined in [RFC9124] are addressed by this
draft and its extensions. The specific mapping of requirements and
information elements in [RFC9124] to manifest data structures is
outlined in the table below:
+============================+===================+===================================+
|Security Requirement |Information Element|Implementation |
+============================+===================+===================================+
|REQ.SEC.SEQUENCE |Monotonic Sequence |Section 8.4.2 |
| |Number | |
+----------------------------+-------------------+-----------------------------------+
|REQ.SEC.COMPATIBLE |Vendor ID |Section 8.4.9.1 |
| |Condition, Class ID| |
| |Condition | |
+----------------------------+-------------------+-----------------------------------+
|REQ.SEC.EXP |Expiration Time |[I-D.ietf-suit-update-management] |
+----------------------------+-------------------+-----------------------------------+
|REQ.SEC.AUTHENTIC |Signature, Payload |Section 8.3, Section 8.4.9.2 |
| |Digests | |
+----------------------------+-------------------+-----------------------------------+
|REQ.SEC.AUTH.IMG_TYPE |Payload Format |[I-D.ietf-suit-update-management] |
+----------------------------+-------------------+-----------------------------------+
|REQ.SEC.AUTH.IMG_LOC |Storage Location |Section 8.4.5.1 |
+----------------------------+-------------------+-----------------------------------+
|REQ.SEC.AUTH.REMOTE_LOC |Payload Indicator |Section 8.4.8.10 |
+----------------------------+-------------------+-----------------------------------+
|REQ.SEC.AUTH.EXEC |Payload Digests, |Section 8.4.8.6, Section 8.4.8.7 |
| |Size | |
+----------------------------+-------------------+-----------------------------------+
|REQ.SEC.AUTH.PRECURSOR |Precursor Image |Section 8.4.8.6 |
| |Digest | |
+----------------------------+-------------------+-----------------------------------+
|REQ.SEC.AUTH.COMPATIBILITY |Authenticated |Section 8.4.8.3, Section 8.4.8.4 |
| |Vendor and Class | |
| |IDs | |
+----------------------------+-------------------+-----------------------------------+
|REQ.SEC.RIGHTS |Signature |Section 8.3, Section 9 |
+----------------------------+-------------------+-----------------------------------+
|REQ.SEC.IMG.CONFIDENTIALITY |Encryption Wrapper |[I-D.ietf-suit-firmware-encryption]|
Moran, et al. Expires 29 November 2025 [Page 70]
Internet-Draft CBOR-based SUIT Manifest May 2025
+----------------------------+-------------------+-----------------------------------+
|REQ.SEC.ACCESS_CONTROL: |None |Section 9 |
|Access Control | | |
+----------------------------+-------------------+-----------------------------------+
|REQ.SEC.MFST.CONFIDENTIALITY|Manifest Encryption|[I-D.ietf-suit-firmware-encryption]|
| |Wrapper / Transport| |
| |Security | |
+----------------------------+-------------------+-----------------------------------+
|REQ.SEC.IMG.COMPLETE_DIGEST |Payload Digests |Implementation Consideration |
+----------------------------+-------------------+-----------------------------------+
|REQ.SEC.REPORTING |None |[I-D.ietf-suit-report], [RFC9334] |
+----------------------------+-------------------+-----------------------------------+
|REQ.SEC.KEY.PROTECTION |None |Implementation Consideration |
+----------------------------+-------------------+-----------------------------------+
|REQ.SEC.KEY.ROTATION |None |[I-D.tschofenig-cose-cwt-chain], |
| | |Implementation Consideration |
+----------------------------+-------------------+-----------------------------------+
|REQ.SEC.MFST.CHECK |None |Deployment Consideration |
+----------------------------+-------------------+-----------------------------------+
|REQ.SEC.MFST.TRUSTED |None |Deployment Consideration |
+----------------------------+-------------------+-----------------------------------+
|REQ.SEC.MFST.CONST |None |Implementation Consideration |
+----------------------------+-------------------+-----------------------------------+
|REQ.USE.MFST.PRE_CHECK |Additional |[I-D.ietf-suit-update-management] |
| |Installation | |
| |Instructions | |
+----------------------------+-------------------+-----------------------------------+
|REQ.USE.MFST.TEXT |Manifest Text |Section 8.4.4 |
| |Information | |
+----------------------------+-------------------+-----------------------------------+
|REQ.USE.MFST.OVERRIDE_REMOTE|Aliases |[RFC3986] Relative URIs, |
| | |[I-D.ietf-suit-trust-domains] |
+----------------------------+-------------------+-----------------------------------+
|REQ.USE.MFST.COMPONENT |Dependencies, |SUIT_Component_Identifier |
| |StorageIdentifier, |(Section 8.4.5.1), |
| |ComponentIdentifier|[I-D.ietf-suit-trust-domains] |
+----------------------------+-------------------+-----------------------------------+
|REQ.USE.MFST.MULTI_AUTH |Signature |Section 8.3 |
+----------------------------+-------------------+-----------------------------------+
|REQ.USE.IMG.FORMAT |Payload Format |[I-D.ietf-suit-update-management] |
+----------------------------+-------------------+-----------------------------------+
|REQ.USE.IMG.NESTED |Processing Steps |[I-D.ietf-suit-firmware-encryption]|
| | |(Encryption Wrapper), |
| | |[I-D.ietf-suit-update-management] |
| | |(Payload Format) |
+----------------------------+-------------------+-----------------------------------+
|REQ.USE.IMG.VERSIONS |Required Image |[I-D.ietf-suit-update-management] |
| |Version List | |
Moran, et al. Expires 29 November 2025 [Page 71]
Internet-Draft CBOR-based SUIT Manifest May 2025
+----------------------------+-------------------+-----------------------------------+
|REQ.USE.IMG.SELECT |XIP Address |Section 8.4.9.4 |
+----------------------------+-------------------+-----------------------------------+
|REQ.USE.EXEC |Runtime Metadata |Section 8.4.6 (suit-invoke) |
+----------------------------+-------------------+-----------------------------------+
|REQ.USE.LOAD |Load-Time Metadata |Section 8.4.6 (suit-load) |
+----------------------------+-------------------+-----------------------------------+
|REQ.USE.PAYLOAD |Payload |Section 7.5 |
+----------------------------+-------------------+-----------------------------------+
|REQ.USE.PARSE |Simple Parsing |Section 6.4 |
+----------------------------+-------------------+-----------------------------------+
|REQ.USE.DELEGATION |Delegation Chain |[I-D.tschofenig-cose-cwt-chain] |
+----------------------------+-------------------+-----------------------------------+
Table 19
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
* Frank Audun Kvamtrø
* Krzysztof Chruściński
* Andrzej Puzdrowski
* Michael Richardson
* David Brown
* Emmanuel Baccelli
Moran, et al. Expires 29 November 2025 [Page 72]
Internet-Draft CBOR-based SUIT Manifest May 2025
We would like to thank our responsible area director, Roman Danyliw,
for his detailed review. Finally, we would like to thank our SUIT
working group chairs (Dave Thaler, David Waltermire, Russ Housley)
for their feedback and support.
14. References
14.1. Normative References
[COSE-Alg] IANA, "CBOR Object Signing and Encryption (COSE) — COSE
Algorithms", <https://www.iana.org/assignments/cose/
cose.xhtml#algorithms>.
[I-D.ietf-suit-firmware-encryption]
Tschofenig, H., Housley, R., Moran, B., Brown, D., and K.
Takayama, "Encrypted Payloads in SUIT Manifests", Work in
Progress, Internet-Draft, draft-ietf-suit-firmware-
encryption-24, 19 March 2025,
<https://datatracker.ietf.org/doc/html/draft-ietf-suit-
firmware-encryption-24>.
[I-D.ietf-suit-mti]
Moran, B., Rønningstad, O., and A. Tsukamoto, "Mandatory-
to-Implement Algorithms for Authors and Recipients of
Software Update for the Internet of Things manifests",
Work in Progress, Internet-Draft, draft-ietf-suit-mti-15,
26 May 2025, <https://datatracker.ietf.org/doc/html/draft-
ietf-suit-mti-15>.
[I-D.ietf-suit-report]
Moran, B. and H. Birkholz, "Secure Reporting of Update
Status", Work in Progress, Internet-Draft, draft-ietf-
suit-report-11, 3 March 2025,
<https://datatracker.ietf.org/doc/html/draft-ietf-suit-
report-11>.
[I-D.ietf-suit-trust-domains]
Moran, B. and K. Takayama, "SUIT Manifest Extensions for
Multiple Trust Domains", Work in Progress, Internet-Draft,
draft-ietf-suit-trust-domains-10, 3 March 2025,
<https://datatracker.ietf.org/doc/html/draft-ietf-suit-
trust-domains-10>.
Moran, et al. Expires 29 November 2025 [Page 73]
Internet-Draft CBOR-based SUIT Manifest May 2025
[I-D.ietf-suit-update-management]
Moran, B. and K. Takayama, "Update Management Extensions
for Software Updates for Internet of Things (SUIT)
Manifests", Work in Progress, Internet-Draft, draft-ietf-
suit-update-management-09, 17 March 2025,
<https://datatracker.ietf.org/doc/html/draft-ietf-suit-
update-management-09>.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/rfc/rfc2119>.
[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/rfc/rfc3986>.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
May 2017, <https://www.rfc-editor.org/rfc/rfc8174>.
[RFC8610] Birkholz, H., Vigano, C., and C. Bormann, "Concise Data
Definition Language (CDDL): A Notational Convention to
Express Concise Binary Object Representation (CBOR) and
JSON Data Structures", RFC 8610, DOI 10.17487/RFC8610,
June 2019, <https://www.rfc-editor.org/rfc/rfc8610>.
[RFC8949] Bormann, C. and P. Hoffman, "Concise Binary Object
Representation (CBOR)", STD 94, RFC 8949,
DOI 10.17487/RFC8949, December 2020,
<https://www.rfc-editor.org/rfc/rfc8949>.
[RFC9019] Moran, B., Tschofenig, H., Brown, D., and M. Meriac, "A
Firmware Update Architecture for Internet of Things",
RFC 9019, DOI 10.17487/RFC9019, April 2021,
<https://www.rfc-editor.org/rfc/rfc9019>.
[RFC9052] Schaad, J., "CBOR Object Signing and Encryption (COSE):
Structures and Process", STD 96, RFC 9052,
DOI 10.17487/RFC9052, August 2022,
<https://www.rfc-editor.org/rfc/rfc9052>.
[RFC9054] Schaad, J., "CBOR Object Signing and Encryption (COSE):
Hash Algorithms", RFC 9054, DOI 10.17487/RFC9054, August
2022, <https://www.rfc-editor.org/rfc/rfc9054>.
Moran, et al. Expires 29 November 2025 [Page 74]
Internet-Draft CBOR-based SUIT Manifest May 2025
[RFC9090] Bormann, C., "Concise Binary Object Representation (CBOR)
Tags for Object Identifiers", RFC 9090,
DOI 10.17487/RFC9090, July 2021,
<https://www.rfc-editor.org/rfc/rfc9090>.
[RFC9124] Moran, B., Tschofenig, H., and H. Birkholz, "A Manifest
Information Model for Firmware Updates in Internet of
Things (IoT) Devices", RFC 9124, DOI 10.17487/RFC9124,
January 2022, <https://www.rfc-editor.org/rfc/rfc9124>.
[RFC9562] Davis, K., Peabody, B., and P. Leach, "Universally Unique
IDentifiers (UUIDs)", RFC 9562, DOI 10.17487/RFC9562, May
2024, <https://www.rfc-editor.org/rfc/rfc9562>.
14.2. Informative References
[I-D.tschofenig-cose-cwt-chain]
Tschofenig, H., Moran, B., and H. Birkholz, "CBOR Object
Signing and Encryption (COSE): Header Parameters for
Carrying and Referencing Chains of CBOR Web Tokens
(CWTs)", Work in Progress, Internet-Draft, draft-
tschofenig-cose-cwt-chain-02, 2 March 2025,
<https://datatracker.ietf.org/doc/html/draft-tschofenig-
cose-cwt-chain-02>.
[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/rfc/rfc7228>.
[RFC9334] Birkholz, H., Thaler, D., Richardson, M., Smith, N., and
W. Pan, "Remote ATtestation procedureS (RATS)
Architecture", RFC 9334, DOI 10.17487/RFC9334, January
2023, <https://www.rfc-editor.org/rfc/rfc9334>.
[RFC9397] Pei, M., Tschofenig, H., Thaler, D., and D. Wheeler,
"Trusted Execution Environment Provisioning (TEEP)
Architecture", RFC 9397, DOI 10.17487/RFC9397, July 2023,
<https://www.rfc-editor.org/rfc/rfc9397>.
[YAML] "YAML Ain’t Markup Language (YAML™) version 1.2", 2021,
<https://yaml.org/spec/1.2.2/>.
Appendix 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
([RFC8610]) data definition.
Moran, et al. Expires 29 November 2025 [Page 75]
Internet-Draft CBOR-based SUIT Manifest May 2025
To be valid, the following CDDL MUST have the COSE CDDL appended to
it. The COSE CDDL can be obtained by following the directions in
[RFC9052], Section 1.4.
SUIT_start = SUIT_Envelope_Tagged / SUIT_Manifest_Tagged / start
SUIT_Envelope_Tagged = #6.107(SUIT_Envelope)
SUIT_Envelope = {
suit-authentication-wrapper => bstr .cbor SUIT_Authentication,
suit-manifest => bstr .cbor SUIT_Manifest,
SUIT_Severable_Manifest_Members,
* SUIT_Integrated_Payload,
* $$SUIT_Envelope_Extensions,
}
SUIT_Authentication = [
bstr .cbor SUIT_Digest,
* bstr .cbor SUIT_Authentication_Block
]
SUIT_Digest = [
suit-digest-algorithm-id : suit-cose-hash-algs,
suit-digest-bytes : bstr,
* $$SUIT_Digest-extensions
]
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-payload-fetch => bstr .cbor SUIT_Command_Sequence,
? suit-install => bstr .cbor SUIT_Command_Sequence,
? suit-text => bstr .cbor SUIT_Text_Map,
* $$SUIT_severable-members-extensions,
)
SUIT_Integrated_Payload = (suit-integrated-payload-key => bstr)
suit-integrated-payload-key = tstr
SUIT_Manifest_Tagged = #6.1070(SUIT_Manifest)
SUIT_Manifest = {
suit-manifest-version => 1,
suit-manifest-sequence-number => uint,
suit-common => bstr .cbor SUIT_Common,
? suit-reference-uri => tstr,
SUIT_Unseverable_Members,
Moran, et al. Expires 29 November 2025 [Page 76]
Internet-Draft CBOR-based SUIT Manifest May 2025
SUIT_Severable_Members_Choice,
* $$SUIT_Manifest_Extensions,
}
SUIT_Unseverable_Members = (
? suit-validate => bstr .cbor SUIT_Command_Sequence,
? suit-load => bstr .cbor SUIT_Command_Sequence,
? suit-invoke => bstr .cbor SUIT_Command_Sequence,
* $$unseverable-manifest-member-extensions,
)
SUIT_Severable_Members_Choice = (
? suit-payload-fetch => SUIT_Digest /
bstr .cbor SUIT_Command_Sequence,
? suit-install => SUIT_Digest / bstr .cbor SUIT_Command_Sequence,
? suit-text => SUIT_Digest / bstr .cbor SUIT_Text_Map,
* $$severable-manifest-members-choice-extensions
)
SUIT_Common = {
? suit-components => SUIT_Components,
? suit-shared-sequence => bstr .cbor SUIT_Shared_Sequence,
* $$SUIT_Common-extensions,
}
SUIT_Components = [ + SUIT_Component_Identifier ]
;REQUIRED to implement:
suit-cose-hash-algs /= cose-alg-sha-256
;OPTIONAL to implement:
suit-cose-hash-algs /= cose-alg-shake128
suit-cose-hash-algs /= cose-alg-sha-384
suit-cose-hash-algs /= cose-alg-sha-512
suit-cose-hash-algs /= cose-alg-shake256
SUIT_Component_Identifier = [* bstr]
SUIT_Shared_Sequence = [
+ ( SUIT_Condition // SUIT_Shared_Commands )
]
SUIT_Shared_Commands //= (suit-directive-set-component-index, IndexArg)
SUIT_Shared_Commands //= (suit-directive-run-sequence,
bstr .cbor SUIT_Shared_Sequence)
SUIT_Shared_Commands //= (suit-directive-try-each,
SUIT_Directive_Try_Each_Argument_Shared)
SUIT_Shared_Commands //= (suit-directive-override-parameters,
Moran, et al. Expires 29 November 2025 [Page 77]
Internet-Draft CBOR-based SUIT Manifest May 2025
{+ $$SUIT_Parameters})
IndexArg /= uint
IndexArg /= true
IndexArg /= [+uint]
SUIT_Directive_Try_Each_Argument_Shared = [
2* bstr .cbor SUIT_Shared_Sequence,
?nil
]
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-component-slot, SUIT_Rep_Policy)
SUIT_Condition //= (suit-condition-check-content, SUIT_Rep_Policy)
SUIT_Condition //= (suit-condition-abort, SUIT_Rep_Policy)
SUIT_Directive //= (suit-directive-write, SUIT_Rep_Policy)
SUIT_Directive //= (suit-directive-set-component-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-override-parameters,
{+ $$SUIT_Parameters})
SUIT_Directive //= (suit-directive-fetch, SUIT_Rep_Policy)
SUIT_Directive //= (suit-directive-copy, SUIT_Rep_Policy)
SUIT_Directive //= (suit-directive-swap, SUIT_Rep_Policy)
SUIT_Directive //= (suit-directive-invoke, SUIT_Rep_Policy)
SUIT_Directive_Try_Each_Argument = [
2* bstr .cbor SUIT_Command_Sequence,
?nil
]
SUIT_Rep_Policy = uint .bits suit-reporting-bits
suit-reporting-bits = &(
suit-send-record-success : 0,
suit-send-record-failure : 1,
Moran, et al. Expires 29 November 2025 [Page 78]
Internet-Draft CBOR-based SUIT Manifest May 2025
suit-send-sysinfo-success : 2,
suit-send-sysinfo-failure : 3
)
$$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-component-slot => uint)
$$SUIT_Parameters //= (suit-parameter-uri => tstr)
$$SUIT_Parameters //= (suit-parameter-fetch-arguments => bstr)
$$SUIT_Parameters //= (suit-parameter-source-component => uint)
$$SUIT_Parameters //= (suit-parameter-invoke-args => bstr)
$$SUIT_Parameters //= (suit-parameter-device-identifier => RFC4122_UUID)
$$SUIT_Parameters //= (suit-parameter-custom => int/bool/tstr/bstr)
$$SUIT_Parameters //= (suit-parameter-content => bstr)
$$SUIT_Parameters //= (suit-parameter-strict-order => bool)
$$SUIT_Parameters //= (suit-parameter-soft-failure => bool)
RFC4122_UUID = bstr .size 16
tag38-ltag = text .regexp "[a-zA-Z]{1,8}(-[a-zA-Z0-9]{1,8})*"
SUIT_Text_Map = {
+ tag38-ltag => SUIT_Text_LMap
}
SUIT_Text_LMap = {
SUIT_Text_Keys,
* SUIT_Component_Identifier => {
SUIT_Text_Component_Keys
}
}
SUIT_Text_Component_Keys = (
? suit-text-vendor-name => tstr,
? suit-text-model-name => tstr,
? suit-text-vendor-domain => tstr,
? suit-text-model-info => tstr,
? suit-text-component-description => tstr,
? suit-text-component-version => tstr,
Moran, et al. Expires 29 November 2025 [Page 79]
Internet-Draft CBOR-based SUIT Manifest May 2025
* $$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-authentication-wrapper = 2
suit-manifest = 3
;REQUIRED to implement:
cose-alg-sha-256 = -16
;OPTIONAL to implement:
cose-alg-shake128 = -18
cose-alg-sha-384 = -43
cose-alg-sha-512 = -44
cose-alg-shake256 = -45
;Unseverable, recipient-necessary
suit-manifest-version = 1
suit-manifest-sequence-number = 2
suit-common = 3
suit-reference-uri = 4
suit-validate = 7
suit-load = 8
suit-invoke = 9
;Severable, recipient-necessary
suit-payload-fetch = 16
suit-install = 20
;Severable, recipient-unnecessary
suit-text = 23
suit-components = 2
suit-shared-sequence = 4
suit-command-custom = nint
suit-condition-vendor-identifier = 1
suit-condition-class-identifier = 2
suit-condition-image-match = 3
suit-condition-component-slot = 5
suit-condition-check-content = 6
Moran, et al. Expires 29 November 2025 [Page 80]
Internet-Draft CBOR-based SUIT Manifest May 2025
suit-condition-abort = 14
suit-condition-device-identifier = 24
suit-directive-set-component-index = 12
suit-directive-try-each = 15
suit-directive-write = 18
suit-directive-override-parameters = 20
suit-directive-fetch = 21
suit-directive-copy = 22
suit-directive-invoke = 23
suit-directive-swap = 31
suit-directive-run-sequence = 32
suit-parameter-vendor-identifier = 1
suit-parameter-class-identifier = 2
suit-parameter-image-digest = 3
suit-parameter-component-slot = 5
suit-parameter-strict-order = 12
suit-parameter-soft-failure = 13
suit-parameter-image-size = 14
suit-parameter-content = 18
suit-parameter-uri = 21
suit-parameter-source-component = 22
suit-parameter-invoke-args = 23
suit-parameter-device-identifier = 24
suit-parameter-fetch-arguments = 25
suit-parameter-custom = nint
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
Moran, et al. Expires 29 November 2025 [Page 81]
Internet-Draft CBOR-based SUIT Manifest May 2025
Appendix 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 |
+-----------------------------+----------+
Table 20
Moran, et al. Expires 29 November 2025 [Page 82]
Internet-Draft CBOR-based SUIT Manifest May 2025
+===================+==========+==========+==========+==========+
| Command | Sys-Fail | Sys-Pass | Rec-Fail | Rec-Pass |
+===================+==========+==========+==========+==========+
| suit-condition- | 1 | 1 | 1 | 1 |
| vendor-identifier | | | | |
+-------------------+----------+----------+----------+----------+
| suit-condition- | 1 | 1 | 1 | 1 |
| class-identifier | | | | |
+-------------------+----------+----------+----------+----------+
| suit-condition- | 1 | 1 | 1 | 1 |
| image-match | | | | |
+-------------------+----------+----------+----------+----------+
| suit-condition- | 0 | 1 | 0 | 1 |
| component-slot | | | | |
+-------------------+----------+----------+----------+----------+
| suit-directive- | 0 | 0 | 1 | 0 |
| fetch | | | | |
+-------------------+----------+----------+----------+----------+
| suit-directive- | 0 | 0 | 1 | 0 |
| copy | | | | |
+-------------------+----------+----------+----------+----------+
| suit-directive- | 0 | 0 | 1 | 0 |
| invoke | | | | |
+-------------------+----------+----------+----------+----------+
Table 21
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:<< [
/ digest: / << [
/ algorithm-id / -16 / "sha256" /,
/ digest-bytes /
h'6658ea560262696dd1f13b782239a064da7c6c5cbaf52fded428a6fc83c7e5af'
] >>,
/ signature: / << 18([
/ protected / << {
/ alg / 1:-7 / "ES256" /
} >>,
Moran, et al. Expires 29 November 2025 [Page 83]
Internet-Draft CBOR-based SUIT Manifest May 2025
/ unprotected / {
},
/ payload / null / nil /,
/ signature / h'408d0816f9b510749bf6a51b066951e08a4438
f849eb092a1ac768eed9de696c1b1dd35d82ef149e6a73a61976ad2cfe78444b806429
3350a122f332cb49f0da'
]) >>
] >>,
/ manifest / 3:<< {
/ manifest-version / 1:1,
/ manifest-sequence-number / 2:0,
/ common / 3:<< {
/ components / 2:[
[h'00']
],
/ shared-sequence / 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:<< [
/ algorithm-id / -16 / "sha256" /,
/ digest-bytes /
h'00112233445566778899aabbccddeeff0123456789abcdeffedcba9876543210'
] >>,
/ image-size / 14:34768
},
/ condition-vendor-identifier / 1,15,
/ condition-class-identifier / 2,15
] >>
} >>,
/ validate / 7:<< [
/ condition-image-match / 3,15
] >>,
/ invoke / 9:<< [
/ directive-invoke / 23,2
] >>
} >>
})
Total size of Envelope without COSE authentication object: 161
Envelope:
Moran, et al. Expires 29 November 2025 [Page 84]
Internet-Draft CBOR-based SUIT Manifest May 2025
d86ba2025827815824822f58206658ea560262696dd1f13b782239a064da
7c6c5cbaf52fded428a6fc83c7e5af035871a50101020003585fa2028181
41000458568614a40150fa6b4a53d5ad5fdfbe9de663e4d41ffe02501492
af1425695e48bf429b2d51f2ab45035824822f5820001122334455667788
99aabbccddeeff0123456789abcdeffedcba98765432100e1987d0010f02
0f074382030f0943821702
Total size of Envelope with COSE authentication object: 237
Envelope with COSE authentication object:
d86ba2025873825824822f58206658ea560262696dd1f13b782239a064da
7c6c5cbaf52fded428a6fc83c7e5af584ad28443a10126a0f65840408d08
16f9b510749bf6a51b066951e08a4438f849eb092a1ac768eed9de696c1b
1dd35d82ef149e6a73a61976ad2cfe78444b8064293350a122f332cb49f0
da035871a50101020003585fa202818141000458568614a40150fa6b4a53
d5ad5fdfbe9de663e4d41ffe02501492af1425695e48bf429b2d51f2ab45
035824822f582000112233445566778899aabbccddeeff0123456789abcd
effedcba98765432100e1987d0010f020f074382030f0943821702
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:<< [
/ digest: / << [
/ algorithm-id / -16 / "sha256" /,
/ digest-bytes /
h'1f2e7acca0dc2786f2fe4eb947f50873a6a3cfaa98866c5b02e621f42074daf2'
] >>,
/ signature: / << 18([
/ protected / << {
/ alg / 1:-7 / "ES256" /
} >>,
/ unprotected / {
},
/ payload / null / nil /,
/ signature / h'27a3d7986eddcc1bee04e1436746408c308ed3
c15ac590a1ca0cf96f85671ccac216cb9a1497fc59e21c15f33c95cf75203e25c287b3
1a57d6cd2ef950b27a7a'
Moran, et al. Expires 29 November 2025 [Page 85]
Internet-Draft CBOR-based SUIT Manifest May 2025
]) >>
] >>,
/ manifest / 3:<< {
/ manifest-version / 1:1,
/ manifest-sequence-number / 2:1,
/ common / 3:<< {
/ components / 2:[
[h'00']
],
/ shared-sequence / 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:<< [
/ algorithm-id / -16 / "sha256" /,
/ digest-bytes /
h'00112233445566778899aabbccddeeff0123456789abcdeffedcba9876543210'
] >>,
/ image-size / 14:34768
},
/ condition-vendor-identifier / 1,15,
/ condition-class-identifier / 2,15
] >>
} >>,
/ validate / 7:<< [
/ condition-image-match / 3,15
] >>,
/ install / 20:<< [
/ directive-override-parameters / 20,{
/ uri / 21:"http://example.com/file.bin"
},
/ directive-fetch / 21,2,
/ condition-image-match / 3,15
] >>
} >>
})
Total size of Envelope without COSE authentication object: 196
Envelope:
Moran, et al. Expires 29 November 2025 [Page 86]
Internet-Draft CBOR-based SUIT Manifest May 2025
d86ba2025827815824822f58201f2e7acca0dc2786f2fe4eb947f50873a6
a3cfaa98866c5b02e621f42074daf2035894a50101020103585fa2028181
41000458568614a40150fa6b4a53d5ad5fdfbe9de663e4d41ffe02501492
af1425695e48bf429b2d51f2ab45035824822f5820001122334455667788
99aabbccddeeff0123456789abcdeffedcba98765432100e1987d0010f02
0f074382030f1458258614a115781b687474703a2f2f6578616d706c652e
636f6d2f66696c652e62696e1502030f
Total size of Envelope with COSE authentication object: 272
Envelope with COSE authentication object:
d86ba2025873825824822f58201f2e7acca0dc2786f2fe4eb947f50873a6
a3cfaa98866c5b02e621f42074daf2584ad28443a10126a0f6584027a3d7
986eddcc1bee04e1436746408c308ed3c15ac590a1ca0cf96f85671ccac2
16cb9a1497fc59e21c15f33c95cf75203e25c287b31a57d6cd2ef950b27a
7a035894a50101020103585fa202818141000458568614a40150fa6b4a53
d5ad5fdfbe9de663e4d41ffe02501492af1425695e48bf429b2d51f2ab45
035824822f582000112233445566778899aabbccddeeff0123456789abcd
effedcba98765432100e1987d0010f020f074382030f1458258614a11578
1b687474703a2f2f6578616d706c652e636f6d2f66696c652e62696e1502
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 5.4), and
text (Section 8.4.4).
107({
/ authentication-wrapper / 2:<< [
/ digest: / << [
/ algorithm-id / -16 / "sha256" /,
/ digest-bytes /
h'6a5197ed8f9dccf733d1c89a359441708e070b4c6dcb9a1c2c82c6165f609b90'
] >>,
/ signature: / << 18([
/ protected / << {
/ alg / 1:-7 / "ES256" /
} >>,
Moran, et al. Expires 29 November 2025 [Page 87]
Internet-Draft CBOR-based SUIT Manifest May 2025
/ unprotected / {
},
/ payload / null / nil /,
/ signature / h'073d8d80ca67d61cdf04d813c748b2de98fe78
6fc67b764431307c8dbcbe91dc6f762c2c4d7bb998ff9ead4798e03c8ee26b89ef7a9a
d4569f6e187ce89e16c5'
]) >>
] >>,
/ manifest / 3:<< {
/ manifest-version / 1:1,
/ manifest-sequence-number / 2:2,
/ common / 3:<< {
/ components / 2:[
[h'00']
],
/ shared-sequence / 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:<< [
/ algorithm-id / -16 / "sha256" /,
/ digest-bytes /
h'00112233445566778899aabbccddeeff0123456789abcdeffedcba9876543210'
] >>,
/ image-size / 14:34768
},
/ condition-vendor-identifier / 1,15,
/ condition-class-identifier / 2,15
] >>
} >>,
/ reference-uri / 4:"https://git.io/JJYoj",
/ validate / 7:<< [
/ condition-image-match / 3,15
] >>,
/ invoke / 9:<< [
/ directive-invoke / 23,2
] >>,
/ install / 20:[
/ algorithm-id / -16 / "sha256" /,
/ digest-bytes /
h'cfa90c5c58595e7f5119a72f803fd0370b3e6abbec6315cd38f63135281bc498'
],
/ text / 23:[
/ algorithm-id / -16 / "sha256" /,
Moran, et al. Expires 29 November 2025 [Page 88]
Internet-Draft CBOR-based SUIT Manifest May 2025
/ digest-bytes /
h'302196d452bce5e8bfeaf71e395645ede6d365e63507a081379721eeecf00007'
]
} >>
})
Total size of the Envelope without COSE authentication object or
Severable Elements: 257
Envelope: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Total size of the Envelope with COSE authentication object but
without Severable Elements: 333
Envelope: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Total size of Envelope with COSE authentication object and Severable
Elements: 923
Envelope with COSE authentication object:
Moran, et al. Expires 29 November 2025 [Page 89]
Internet-Draft CBOR-based SUIT Manifest May 2025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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 7.7)
Moran, et al. Expires 29 November 2025 [Page 90]
Internet-Draft CBOR-based SUIT Manifest May 2025
107({
/ authentication-wrapper / 2:<< [
/ digest: / << [
/ algorithm-id / -16 / "sha256" /,
/ digest-bytes /
h'f6d44a62ec906b392500c242e78e908e9cc5057f3f04104a06a8566200da2ee0'
] >>,
/ signature: / << 18([
/ protected / << {
/ alg / 1:-7 / "ES256" /
} >>,
/ unprotected / {
},
/ payload / null / nil /,
/ signature / h'0bbf7058c1a79dff23c7755d36aae5c6cc1aac
b818f456e2e03f2664c369b9c6700931a52f1f8d808aa4a8e5220d479c9661d2bce0a4
4974004325001e3b1abb'
]) >>
] >>,
/ manifest / 3:<< {
/ manifest-version / 1:1,
/ manifest-sequence-number / 2:3,
/ common / 3:<< {
/ components / 2:[
[h'00']
],
/ shared-sequence / 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,[
<< [
/ directive-override-parameters / 20,{
/ slot / 5:0
},
/ condition-component-slot / 5,5,
/ directive-override-parameters / 20,{
/ image-digest / 3:<< [
/ algorithm-id / -16 / "sha256" /,
/ digest-bytes /
h'00112233445566778899aabbccddeeff0123456789abcdeffedcba9876543210'
] >>,
/ image-size / 14:34768
Moran, et al. Expires 29 November 2025 [Page 91]
Internet-Draft CBOR-based SUIT Manifest May 2025
}
] >>,
<< [
/ directive-override-parameters / 20,{
/ slot / 5:1
},
/ condition-component-slot / 5,5,
/ directive-override-parameters / 20,{
/ image-digest / 3:<< [
/ algorithm-id / -16 / "sha256" /,
/ digest-bytes /
h'0123456789abcdeffedcba987654321000112233445566778899aabbccddeeff'
] >>,
/ image-size / 14:76834
}
] >>
],
/ condition-vendor-identifier / 1,15,
/ condition-class-identifier / 2,15
] >>
} >>,
/ validate / 7:<< [
/ condition-image-match / 3,15
] >>,
/ install / 20:<< [
/ directive-try-each / 15,[
<< [
/ directive-override-parameters / 20,{
/ slot / 5:0
},
/ condition-component-slot / 5,5,
/ directive-override-parameters / 20,{
/ uri / 21:"http://example.com/file1.bin"
}
] >>,
<< [
/ directive-override-parameters / 20,{
/ slot / 5:1
},
/ condition-component-slot / 5,5,
/ directive-override-parameters / 20,{
/ uri / 21:"http://example.com/file2.bin"
}
] >>
],
/ directive-fetch / 21,2,
/ condition-image-match / 3,15
] >>
Moran, et al. Expires 29 November 2025 [Page 92]
Internet-Draft CBOR-based SUIT Manifest May 2025
} >>
})
Total size of Envelope without COSE authentication object: 320
Envelope: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Total size of Envelope with COSE authentication object: 396
Envelope with COSE authentication object:
d86ba2025873825824822f5820f6d44a62ec906b392500c242e78e908e9c
c5057f3f04104a06a8566200da2ee0584ad28443a10126a0f658400bbf70
58c1a79dff23c7755d36aae5c6cc1aacb818f456e2e03f2664c369b9c670
0931a52f1f8d808aa4a8e5220d479c9661d2bce0a44974004325001e3b1a
bb0359010fa5010102030358a4a2028181410004589b8814a20150fa6b4a
53d5ad5fdfbe9de663e4d41ffe02501492af1425695e48bf429b2d51f2ab
450f8258348614a10500050514a2035824822f5820001122334455667788
99aabbccddeeff0123456789abcdeffedcba98765432100e1987d0583686
14a10501050514a2035824822f58200123456789abcdeffedcba98765432
1000112233445566778899aabbccddeeff0e1a00012c22010f020f074382
030f14585b860f8258288614a10500050514a115781c687474703a2f2f65
78616d706c652e636f6d2f66696c65312e62696e58288614a10501050514
a115781c687474703a2f2f6578616d706c652e636f6d2f66696c65322e62
696e1502030f
B.5. Example 4: Load from External Storage
This example covers the following templates:
* Compatibility Check (Section 7.1)
* Secure Boot (Section 7.2)
* Firmware Download (Section 7.3)
Moran, et al. Expires 29 November 2025 [Page 93]
Internet-Draft CBOR-based SUIT Manifest May 2025
* Install (Section 7.4)
* Load (Section 7.6)
107({
/ authentication-wrapper / 2:<< [
/ digest: / << [
/ algorithm-id / -16 / "sha256" /,
/ digest-bytes /
h'5b5f6586b1e6cdf19ee479a5adabf206581000bd584b0832a9bdaf4f72cdbdd6'
] >>,
/ signature: / << 18([
/ protected / << {
/ alg / 1:-7 / "ES256" /
} >>,
/ unprotected / {
},
/ payload / null / nil /,
/ signature / h'c53c2826b042384e95c646cbcd4308b181f1ed
2bfbeb4e70b93cac9fbdc82e382d877e2c2bcfaf975ffcd36941f2f4db89f68d3c77d6
a3506e9b1509a49dec46'
]) >>
] >>,
/ manifest / 3:<< {
/ manifest-version / 1:1,
/ manifest-sequence-number / 2:4,
/ common / 3:<< {
/ components / 2:[
[h'00'],
[h'02'],
[h'01']
],
/ shared-sequence / 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:<< [
/ algorithm-id / -16 / "sha256" /,
/ digest-bytes /
h'00112233445566778899aabbccddeeff0123456789abcdeffedcba9876543210'
] >>,
/ image-size / 14:34768
},
Moran, et al. Expires 29 November 2025 [Page 94]
Internet-Draft CBOR-based SUIT Manifest May 2025
/ condition-vendor-identifier / 1,15,
/ condition-class-identifier / 2,15
] >>
} >>,
/ validate / 7:<< [
/ directive-set-component-index / 12,0,
/ condition-image-match / 3,15
] >>,
/ load / 8:<< [
/ directive-set-component-index / 12,2,
/ directive-override-parameters / 20,{
/ image-digest / 3:<< [
/ algorithm-id / -16 / "sha256" /,
/ digest-bytes /
h'0123456789abcdeffedcba987654321000112233445566778899aabbccddeeff'
] >>,
/ image-size / 14:76834,
/ source-component / 22:0 / [h'00'] /
},
/ directive-copy / 22,2,
/ condition-image-match / 3,15
] >>,
/ invoke / 9:<< [
/ directive-set-component-index / 12,2,
/ directive-invoke / 23,2
] >>,
/ payload-fetch / 16:<< [
/ directive-set-component-index / 12,1,
/ directive-override-parameters / 20,{
/ image-digest / 3:<< [
/ algorithm-id / -16 / "sha256" /,
/ digest-bytes /
h'00112233445566778899aabbccddeeff0123456789abcdeffedcba9876543210'
] >>,
/ uri / 21:"http://example.com/file.bin"
},
/ directive-fetch / 21,2,
/ condition-image-match / 3,15
] >>,
/ install / 20:<< [
/ directive-set-component-index / 12,0,
/ directive-override-parameters / 20,{
/ source-component / 22:1 / [h'02'] /
},
/ directive-copy / 22,2,
/ condition-image-match / 3,15
] >>
} >>
Moran, et al. Expires 29 November 2025 [Page 95]
Internet-Draft CBOR-based SUIT Manifest May 2025
})
Total size of Envelope without COSE authentication object: 327
Envelope: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Total size of Envelope with COSE authentication object: 403
Envelope with COSE authentication object: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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.
Moran, et al. Expires 29 November 2025 [Page 96]
Internet-Draft CBOR-based SUIT Manifest May 2025
107({
/ authentication-wrapper / 2:<< [
/ digest: / << [
/ algorithm-id / -16 / "sha256" /,
/ digest-bytes /
h'15ce60f77657e4531dc329155f8b0ed78f94bdc6d165b2665473693dcc34f470'
] >>,
/ signature: / << 18([
/ protected / << {
/ alg / 1:-7 / "ES256" /
} >>,
/ unprotected / {
},
/ payload / null / nil /,
/ signature / h'53505bf2b1aba7f3c3e142d6c02350daf95331
a8942e77d7378c6670285638e0fe460fe7cebcbe242b14e7ac1a4482cf500136a2568a
92a803f614d5f87ef7a7'
]) >>
] >>,
/ manifest / 3:<< {
/ manifest-version / 1:1,
/ manifest-sequence-number / 2:5,
/ common / 3:<< {
/ components / 2:[
[h'00'],
[h'01']
],
/ shared-sequence / 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:<< [
/ algorithm-id / -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:<< [
Moran, et al. Expires 29 November 2025 [Page 97]
Internet-Draft CBOR-based SUIT Manifest May 2025
/ algorithm-id / -16 / "sha256" /,
/ digest-bytes /
h'0123456789abcdeffedcba987654321000112233445566778899aabbccddeeff'
] >>,
/ image-size / 14:76834
}
] >>
} >>,
/ validate / 7:<< [
/ directive-set-component-index / 12,0,
/ condition-image-match / 3,15,
/ directive-set-component-index / 12,1,
/ condition-image-match / 3,15
] >>,
/ invoke / 9:<< [
/ directive-set-component-index / 12,0,
/ directive-invoke / 23,2
] >>,
/ install / 20:<< [
/ directive-set-component-index / 12,0,
/ directive-override-parameters / 20,{
/ uri / 21:"http://example.com/file1.bin"
},
/ directive-fetch / 21,2,
/ condition-image-match / 3,15,
/ directive-set-component-index / 12,1,
/ directive-override-parameters / 20,{
/ uri / 21:"http://example.com/file2.bin"
},
/ directive-fetch / 21,2,
/ condition-image-match / 3,15
] >>
} >>
})
Total size of Envelope without COSE authentication object: 306
Envelope:
Moran, et al. Expires 29 November 2025 [Page 98]
Internet-Draft CBOR-based SUIT Manifest May 2025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Total size of Envelope with COSE authentication object: 382
Envelope with COSE authentication object:
d86ba2025873825824822f582015ce60f77657e4531dc329155f8b0ed78f
94bdc6d165b2665473693dcc34f470584ad28443a10126a0f6584053505b
f2b1aba7f3c3e142d6c02350daf95331a8942e77d7378c6670285638e0fe
460fe7cebcbe242b14e7ac1a4482cf500136a2568a92a803f614d5f87ef7
a703590101a601010205035895a202828141008141010458898c0c0014a4
0150fa6b4a53d5ad5fdfbe9de663e4d41ffe02501492af1425695e48bf42
9b2d51f2ab45035824822f582000112233445566778899aabbccddeeff01
23456789abcdeffedcba98765432100e1987d0010f020f0c0114a2035824
822f58200123456789abcdeffedcba987654321000112233445566778899
aabbccddeeff0e1a00012c220749880c00030f0c01030f0945840c001702
14584f900c0014a115781c687474703a2f2f6578616d706c652e636f6d2f
66696c65312e62696e1502030f0c0114a115781c687474703a2f2f657861
6d706c652e636f6d2f66696c65322e62696e1502030f
Appendix C. Design Rationale
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,
Moran, et al. Expires 29 November 2025 [Page 99]
Internet-Draft CBOR-based SUIT Manifest May 2025
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.
Dependency handling is covered in [I-D.ietf-suit-trust-domains].
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 8.6)
2. This enables modular processing of manifests, particularly with
large signatures.
Moran, et al. Expires 29 November 2025 [Page 100]
Internet-Draft CBOR-based SUIT Manifest May 2025
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 shared sequence. The shared
sequence is wrapped so that it matches other sequences, simplifying
the code path.
Moran, et al. Expires 29 November 2025 [Page 101]
Internet-Draft CBOR-based SUIT Manifest May 2025
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.
Authors' Addresses
Brendan Moran
Arm Limited
Email: brendan.moran.ietf@gmail.com
Hannes Tschofenig
University of Applied Sciences Bonn-Rhein-Sieg
Germany
Email: Hannes.Tschofenig@gmx.net
Henk Birkholz
Fraunhofer SIT
Rheinstrasse 75
64295 Darmstadt
Germany
Email: henk.birkholz@sit.fraunhofer.de
Koen Zandberg
Inria
Email: koen.zandberg@inria.fr
Øyvind Rønningstad
Nordic Semiconductor
Email: oyvind.ronningstad@gmail.com
Moran, et al. Expires 29 November 2025 [Page 102]