SUIT CBOR manifest serialisation format
draft-moran-suit-manifest-04
The information below is for an old version of the document.
| Document | Type |
This is an older version of an Internet-Draft whose latest revision state is "Replaced".
|
|
|---|---|---|---|
| Authors | Brendan Moran , Hannes Tschofenig , Henk Birkholz | ||
| Last updated | 2019-03-11 (Latest revision 2018-10-21) | ||
| Replaces | draft-moran-fud-manifest | ||
| Replaced by | draft-ietf-suit-manifest, draft-ietf-suit-manifest | ||
| RFC stream | (None) | ||
| Formats | |||
| Additional resources | |||
| Stream | Stream state | (No stream defined) | |
| Consensus boilerplate | Unknown | ||
| RFC Editor Note | (None) | ||
| IESG | IESG state | I-D Exists | |
| Telechat date | (None) | ||
| Responsible AD | (None) | ||
| Send notices to | (None) |
draft-moran-suit-manifest-04
SUIT B. Moran
Internet-Draft H. Tschofenig
Intended status: Informational Arm Limited
Expires: September 12, 2019 H. Birkholz
Fraunhofer SIT
March 11, 2019
SUIT CBOR manifest serialisation format
draft-moran-suit-manifest-04
Abstract
This specification describes the format of a manifest. A manifest is
a bundle of metadata about the firmware for an IoT device, where to
find the firmware, the devices to which it applies, and cryptographic
information protecting the manifest.
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 September 12, 2019.
Copyright Notice
Copyright (c) 2019 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
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publication of this document. Please review these documents
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to this document. Code Components extracted from this document must
include Simplified BSD License text as described in Section 4.e of
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the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
This document may contain material from IETF Documents or IETF
Contributions published or made publicly available before November
10, 2008. The person(s) controlling the copyright in some of this
material may not have granted the IETF Trust the right to allow
modifications of such material outside the IETF Standards Process.
Without obtaining an adequate license from the person(s) controlling
the copyright in such materials, this document may not be modified
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it for publication as an RFC or to translate it into languages other
than English.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Conventions and Terminology . . . . . . . . . . . . . . . . . 4
3. SUIT digest container . . . . . . . . . . . . . . . . . . . . 5
4. Distributing firmware . . . . . . . . . . . . . . . . . . . . 6
5. Workflow of a device applying a firmware update . . . . . . . 6
6. SUIT manifest goals . . . . . . . . . . . . . . . . . . . . . 6
7. SUIT manifest design overview . . . . . . . . . . . . . . . . 8
7.1. Severable Elements . . . . . . . . . . . . . . . . . . . 9
7.2. Conventions . . . . . . . . . . . . . . . . . . . . . . . 9
7.3. Payloads . . . . . . . . . . . . . . . . . . . . . . . . 10
8. Manifest Structure . . . . . . . . . . . . . . . . . . . . . 10
8.1. Outer wrapper . . . . . . . . . . . . . . . . . . . . . . 12
8.2. Manifest . . . . . . . . . . . . . . . . . . . . . . . . 13
8.3. SUIT_Dependency . . . . . . . . . . . . . . . . . . . . . 16
8.4. SUIT_Component . . . . . . . . . . . . . . . . . . . . . 17
8.5. SUIT_Component_Reference . . . . . . . . . . . . . . . . 17
8.6. Manifest Parameters . . . . . . . . . . . . . . . . . . . 18
8.6.1. SUIT_Parameter_Strict_Order . . . . . . . . . . . . . 20
8.6.2. SUIT_Parameter_Coerce_Condition_Failure . . . . . . . 20
8.7. SUIT_Parameter_Encryption_Info . . . . . . . . . . . . . 20
8.8. SUIT_Parameter_Compression_Info . . . . . . . . . . . . . 20
8.9. SUIT_Parameter_Unpack_Info . . . . . . . . . . . . . . . 21
8.10. SUIT_Parameters CDDL . . . . . . . . . . . . . . . . . . 21
8.11. SUIT_Command_Sequence . . . . . . . . . . . . . . . . . . 23
8.12. SUIT_Condition . . . . . . . . . . . . . . . . . . . . . 24
8.12.1. ID Conditions . . . . . . . . . . . . . . . . . . . 25
8.12.2. SUIT_Condition_Image_Match . . . . . . . . . . . . . 26
8.12.3. SUIT_Condition_Image_Not_Match . . . . . . . . . . . 26
8.12.4. SUIT_Condition_Use_Before . . . . . . . . . . . . . 26
8.12.5. SUIT_Condition_Minimum_Battery . . . . . . . . . . . 26
8.12.6. SUIT_Condition_Update_Authorised . . . . . . . . . . 27
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8.12.7. SUIT_Condition_Version . . . . . . . . . . . . . . . 27
8.12.8. SUIT_Condition_Custom . . . . . . . . . . . . . . . 28
8.12.9. Identifiers . . . . . . . . . . . . . . . . . . . . 28
8.12.10. SUIT_Condition CDDL . . . . . . . . . . . . . . . . 29
8.13. SUIT_Directive . . . . . . . . . . . . . . . . . . . . . 30
8.13.1. SUIT_Directive_Set_Component_Index . . . . . . . . . 31
8.13.2. SUIT_Directive_Set_Manifest_Index . . . . . . . . . 32
8.13.3. SUIT_Directive_Run_Sequence . . . . . . . . . . . . 32
8.13.4. SUIT_Directive_Run_Sequence_Conditional . . . . . . 33
8.13.5. SUIT_Directive_Process_Dependency . . . . . . . . . 33
8.13.6. SUIT_Directive_Set_Parameters . . . . . . . . . . . 33
8.13.7. SUIT_Directive_Set_Parameter_State_Append . . . . . 34
8.13.8. SUIT_Directive_Override_Parameters . . . . . . . . . 34
8.13.9. SUIT_Directive_Fetch . . . . . . . . . . . . . . . . 34
8.13.10. SUIT_Directive_Copy . . . . . . . . . . . . . . . . 35
8.13.11. SUIT_Directive_Run . . . . . . . . . . . . . . . . . 36
8.13.12. SUIT_Directive_Wait . . . . . . . . . . . . . . . . 36
8.13.13. SUIT_Directive CDDL . . . . . . . . . . . . . . . . 37
9. Dependency processing . . . . . . . . . . . . . . . . . . . . 39
10. Access Control Lists . . . . . . . . . . . . . . . . . . . . 40
11. Creating conditional sequences . . . . . . . . . . . . . . . 40
12. Full CDDL . . . . . . . . . . . . . . . . . . . . . . . . . . 41
13. Examples . . . . . . . . . . . . . . . . . . . . . . . . . . 46
13.1. Example 0: . . . . . . . . . . . . . . . . . . . . . . . 47
13.2. Example 1: . . . . . . . . . . . . . . . . . . . . . . . 48
13.3. Example 2: . . . . . . . . . . . . . . . . . . . . . . . 50
13.4. Example 3: . . . . . . . . . . . . . . . . . . . . . . . 53
13.5. Example 4: . . . . . . . . . . . . . . . . . . . . . . . 56
13.6. Example 5: . . . . . . . . . . . . . . . . . . . . . . . 59
13.7. Example 6: . . . . . . . . . . . . . . . . . . . . . . . 62
14. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 65
15. Security Considerations . . . . . . . . . . . . . . . . . . . 65
16. Mailing List Information . . . . . . . . . . . . . . . . . . 66
17. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 66
18. References . . . . . . . . . . . . . . . . . . . . . . . . . 66
18.1. Normative References . . . . . . . . . . . . . . . . . . 66
18.2. Informative References . . . . . . . . . . . . . . . . . 67
18.3. URIs . . . . . . . . . . . . . . . . . . . . . . . . . . 67
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 68
1. Introduction
A firmware update mechanism is an essential security feature for IoT
devices to deal with vulnerabilities. While the transport of
firmware images to the devices themselves is important there are
already various techniques available, such as the Lightweight
Machine-to-Machine (LwM2M) protocol offering device management of IoT
devices. Equally important is the inclusion of meta-data about the
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conveyed firmware image (in the form of a manifest) and the use of
end-to-end security protection to detect modifications and
(optionally) to make reverse engineering more difficult. End-to-end
security allows the author, who builds the firmware image, to be sure
that no other party (including potential adversaries) can install
firmware updates on IoT devices without adequate privileges. This
authorization process is ensured by the use of dedicated symmetric or
asymmetric keys installed on the IoT device: for use cases where only
integrity protection is required it is sufficient to install a trust
anchor on the IoT device. For confidentiality protected firmware
images it is additionally required to install either one or multiple
symmetric or asymmetric keys on the IoT device. Starting security
protection at the author is a risk mitigation technique so firmware
images and manifests can be stored on untrusted respositories; it
also reduces the scope of a compromise of any repository or
intermediate system to be no worse than a denial of service.
It is assumed that the reader is familiar with the high-level
firmware update architecture [Architecture]. This document is
structured as follows: In Section 8 we describe the main building
blocks of the manifest and Section 12 contains the description of the
CBOR of the manifest.
The SUIT manifest is heavily optimised for consumption by constrained
devices. This means that it is not constructed as a conventional
descriptive document, as described in [Behaviour]. This means that a
user viewing the contents of the document will require tooling to
view the contents in a more descriptive way.
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.
- SUIT: Sofware Update for the Internet of Things, 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.
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- Manifest: A piece of information that describes one or more
payloads, one or more resources, and the processors needed to
transform resources into payloads.
- Update: One or more manifests that describe one or more payloads.
- Update Authority: The owner of a cryptographic key used to sign
updates, trusted by recipient devices.
- Recipient: The system, typically an IoT device, that receives a
manifest.
- Condition: A test for a property of the Recipient or its
components.
- Directive: An action for the Recipient to perform.
- Command: A Condition or a Directive.
3. SUIT digest container
RFC 8152 [RFC8152] provides containers for signature, MAC, and
encryption, but no basic digest container. The container needed for
a digest requires a type identifier and a container for the raw
digest data. Some forms of digest may require additional parameters.
These can be added following the digest. Algorithm identifiers
defined in RFC 6920 [RFC6920] are reused for this digest container.
This structure is described by the following CDDL:
SUIT_Digest = [
suit-digest-algorithm-id : $suit-digest-algorithm-ids,
suit-digest-bytes : bytes,
? suit-digest-parameters : any
]
; Named Information Hash Algorithm Identifiers
digest-algorithm-ids /= algorithm-id-sha256
digest-algorithm-ids /= algorithm-id-sha256-128
digest-algorithm-ids /= algorithm-id-sha256-120
digest-algorithm-ids /= algorithm-id-sha256-96
digest-algorithm-ids /= algorithm-id-sha256-64
digest-algorithm-ids /= algorithm-id-sha256-32
digest-algorithm-ids /= algorithm-id-sha384
digest-algorithm-ids /= algorithm-id-sha512
digest-algorithm-ids /= algorithm-id-sha3-224
digest-algorithm-ids /= algorithm-id-sha3-256
digest-algorithm-ids /= algorithm-id-sha3-384
digest-algorithm-ids /= algorithm-id-sha3-512
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4. Distributing firmware
Distributing firmware in a multi-party environment is a difficult
operation. 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 [Architecture]
5. Workflow of a device applying a firmware update
The manifest is designed to work with a pull parser, where each
section of the manifest is used in sequence. The expected workflow
for a device installing an update can be broken down into 5 steps:
1. Verify the signature of the manifest
2. Verify the applicability of the manifest
3. Resolve dependencies
4. Fetch payload(s)
5. Install payload(s)
When installation is complete, similar information can be used for
validating and running images in a further three steps:
1. Verify image(s)
2. Load image(s)
3. Run image(s)
When multiple manifests are used for an update, each manifest's steps
occur in a lockstep fashion; all manifests have dependency resolution
performed before any manifest performs a payload fetch, etc.
6. SUIT manifest goals
The manifest described in this document is intended to simplify the
construction of constrained device firmware update solutions. It is
also intended to allow update authors to describe complex update
processes for complex devices.
Manifests implemented as descriptive documents require changes to the
parser and the information model whenever a new feature is added.
This is particularly accentuated when the parser is a fixed-function
minimal parser (or a pull parser) such as the type that is typically
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used in a bootloader or in a constrained client. The issue is not as
significant in devices that can use general purpose parsers.
The manifest detailed in this document aims to address these and more
problems by changing the processing model from a piece of software
that loads a manifest, interprets the data, then performs some
actions, into a model in which the software performs exactly the
operations stated in the manifest, in order. This allows the
manifest to encode data in a way that matches precisely with what the
parser expects. It also makes inflexible code, like a bootloader,
more flexible in what it can do; because the manifest defines part of
the "program," the manifest's execution defines part of the behaviour
of the system. Further detail on this approach is covered in
[Behaviour]
The SUIT manifest can be used for a variety of purposes throughout
its lifecycle. The manifest allows:
1. the Firmware Author to reason about releasing a firmware.
2. the Network Operator to reason about compatibility of a firmware.
3. the Device Operator to reason about the impact of a firmware.
4. the Device Operator to manage distribution of firmware to
devices.
5. the Plant Manager to reason about timing and acceptance of
firmware updates.
6. the device to reason about the authority & authenticity of a
firmware prior to installation.
7. the device to reason about the applicability of a firmware.
8. the device to reason about the installation of a firmware.
9. the device to reason about the authenticity of a firmware at
boot.
Each of these uses happens at a different stage of the manifest
lifecycle, so each has different requirements.
To verify authenticity at boot time, only the smallest portion of the
manifest is required. This core part of the manifest describes only
the fully installed firmware and any of its dependencies.
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7. SUIT manifest design overview
In order to provide flexible behaviour to constrained devices, while
still allowing more powerful devices to use their full capabilities,
the SUIT manifest takes a new approach, encoding the required
behaviour of a Recipient device, instead of just presenting the
information used to determine that behaviour. This gives benefits
equivalent to those provided by a scripting language or 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 secure boot of a firmware image. The
language specifies behaviours in a linearised form, without branches
or loops. 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 with minimal functionality to
perform complex updates with reduced overhead. Conditional execution
of commands allows a simple device to perform important decisions at
validation-time, such as which differential update to download for a
given current version, or which hash to check, based on the
installation address.
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
behaviour by setting parameters. Because some parameters come with
security implications, the dependencies also have a mechanism to
reject modifications to parameters on a fine-grained level.
Developing a robust permissions system works in this model too. The
Recipient can use a simple ACL that is a table of Identities and
Component Identifier permissions to ensure that only manifests
authenticated by the appropriate identity have access to define a
component.
Capability reporting is similarly simplified. A Recipient can report
the Commands and Parameters that it supports. This is sufficiently
precise for a manifest author to create a manifest that the Recipient
can accept.
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The simplicity of design in the Recipient due to all of these
benefits allows even a highly constrained platform to use advanced
update capabilities.
7.1. Severable Elements
Because the manifest can be used by different actors at different
times, some parts of the manifest can be removed without affecting
later stages of the lifecycle. This is called "Severing." 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 authenticity of severable parts of the
manifest is a requirement for the signed portion of the manifest.
Severing some parts makes it possible to discard parts of the
manifest that are no longer necessary. This is important because it
allows the storage used by the manifest to be greatly reduced. For
example, no text size limits are needed if text is removed from the
manifest prior to delivery to a constrained device.
Elements are made severable by removing them from the manifest,
encoding them in a bstr, and placing a SUIT_Digest of the bstr in the
manifest so that they can still be authenticated. The SUIT_Digest
typically consumes 4 bytes more than the size of the raw digest,
therefore elements smaller than (Digest Bits)/8 + 4 SHOULD never 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.
7.2. Conventions
The map indices in this 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
uninitialised variables. Positive numbers in enumerations are
reserved for IANA registration. Negative numbers are used to
identify application-specific implementations.
CDDL names are hyphenated and CDDL structures follow the convention
adopted in COSE [RFC8152]: SUIT_Structure_Name.
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7.3. Payloads
Payloads can take many forms, for example, binary, hex, s-record,
elf, binary diff, PEM certificate, CBOR Web Token, serialised
configuration. These payloads fall into two broad categories: those
that require installation-time unpacking and those that do not.
Binary, PEM certificate, and CBOR Web Token do not require
installation-time unpacking. Hex, s-record, elf, and serialised
configuration require installation-time unpacking.
Some payloads cannot be directly converted to a writable binary
stream. Hex, s-record, and elf may contain gaps and they have no
guarantee of monotonic increase of address, which makes pre-
processing them into a binary stream difficult on constrained
platforms. Serialised configuration may be unpacked into a
configuration database, which makes it impossible to preprocess into
a binary stream, suitable for direct writing.
Where a specialised unpacking algorithm is needed, a digest is not
always calculable over an installed payload. For example, an elf,
s-record or hex file may contain gaps that can contain any data,
while not changing whether or not an installed payload is valid.
Serialised configuration may update only some device data rather than
all of it. This means that the digest cannot always be calculated
over an installed payload when a specialised installer is used.
This presents two problems for the manifest: first, it must indicate
that a specialised installer is needed and, second, it cannot provide
a hash of the payload that is checkable after installation. These
two problems are resolved in two ways:
1. Payloads that need a specialised installer must indicate this in
suit-payload-info-unpack.
2. Payloads that need specialised verification must indicate this in
the SUIT_Payload section or SUIT_Parameter_Image_Digest by
indicating a SUIT_Digest algorithm that correctly validates their
information.
8. Manifest Structure
The manifest is divided into several sections in a hierarchy as
follows:
1. The outer wrapper
1. The authentication wrapper
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2. The manifest
1. Critical Information
2. List of dependencies
3. List of payloads
4. List of payloads in dependencies
5. Common list of conditions, directives
6. Dependency resolution Reference or list of conditions,
directives
7. Payload fetch Reference or list of conditions,
directives
8. Installation Reference or list of conditions, directives
9. Verification conditions/directives
10. Load conditions/directives
11. Run conditions/directives
12. Text / Reference
13. COSWID / Reference
3. Dependency resolution conditions/directives
4. Payload fetch conditions/directives
5. Installation conditions/directives
6. Text
7. COSWID / Reference
8. Intermediate Certificate(s) / CWTs
9. Small Payload(s)
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8.1. Outer wrapper
This object is a container for the other pieces of the manifest to
provide a common mechanism to find each of the parts. All elements
of the outer wrapper are contained in bstr objects. Wherever the
manifest references an object in the outer wrapper, the bstr is
included in the digest calculation.
The CDDL that describes the wrapper is below
SUIT_Outer_Wrapper = {
suit-authentication-wrapper => bstr .cbor
SUIT_Authentication_Wrapper / nil,
suit-manifest => bstr .cbor Manifest,
suit-dependency-resolution => bstr .cbor SUIT_Command_Sequence,
suit-payload-fetch => bstr .cbor SUIT_Command_Sequence,
suit-install => bstr .cbor SUIT_Command_Sequence,
suit-text-external => bstr .cbor SUIT_Text_Info,
suit-coswid-external => bstr .cbor COSWID
}
suit-authentication-wrapper = 1
suit-manifest = 2
suit-dependency-resolution = 7
suit-payload-fetch = 8
suit-install = 9
suit-text = 13
suit-coswid = 14
SUIT_Authentication_Wrapper = [ * (COSE_Mac_Tagged / COSE_Sign_Tagged /
COSE_Mac0_Tagged / COSE_Sign1_Tagged)]
All elements of the outer wrapper 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 serialisation for
integrity and authenticity checks.
The suit-authentication-wrapper contains a list of 1 or more
cryptographic authentication wrappers for the core part of the
manifest. These are implemented as COSE_Mac_Tagged or
COSE_Sign_Tagged blocks. The Manifest is authenticated by these
blocks in "detached payload" mode. The COSE_Mac_Tagged and
COSE_Sign_Tagged blocks are described in RFC 8152 [RFC8152] and are
beyond the scope of this document. The suit-authentication-wrapper
MUST come first in the SUIT_Outer_Wrapper, regardless of canonical
encoding of CBOR. All validators MUST reject any SUIT_Outer_Wrapper
that begins with any element other than a suit-authentication-
wrapper.
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A manifest that has not had authentication information added MUST
still contain the suit-authentication-wrapper element, but the
content MUST be null.
suit-manifest contains a Manifest structure, which describes the
payload(s) to be installed and any dependencies on other manifests.
Each of suit-dependency-resolution, suit-payload-fetch, and suit-
payload-installation contain the severable contents of the
identically named portions of the manifest, described in Section 8.2.
suit-text contains all the human-readable information that describes
any and all parts of the manifest, its payload(s) and its
resource(s).
suit-coswid contains a Concise Software Identifier. This may be
discarded by the recipient if not needed.
8.2. Manifest
The manifest describes the critical metadata for the referenced
payload(s). In addition, it contains:
1. a version number for the manifest structure itself
2. a sequence number
3. a list of dependencies
4. a list of components affected
5. a list of components affected by dependencies
6. a reference for each of the severable blocks.
7. a list of actions that the recipient should perform.
The following CDDL fragment defines the manifest.
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SUIT_Manifest = {
suit-manifest-version => 1,
suit-manifest-sequence-number => uint,
? suit-dependencies => [ + SUIT_Dependency ],
? suit-components => [ + SUIT_Component ],
? suit-dependency-components => [ + SUIT_Component_Reference ],
? suit-common => bstr .cbor SUIT_Command_Sequence,
? suit-dependency-resolution => Digest / bstr .cbor SUIT_Command_Sequence,
? suit-payload-fetch => Digest / bstr .cbor SUIT_Command_Sequence,
? suit-install => Digest / bstr .cbor SUIT_Command_Sequence
? suit-validate => bstr .cbor SUIT_Command_Sequence
? suit-load => bstr .cbor SUIT_Command_Sequence
? suit-run => bstr .cbor SUIT_Command_Sequence
? suit-text-info => Digest / bstr .cbor SUIT_Text_Map
? suit-coswid => Digest / bstr .cbor COSWID
}
suit-manifest-version = 1
suit-manifest-sequence-number = 2
suit-dependencies = 3
suit-components = 4
suit-dependency-components = 5
suit-common = 6
suit-dependency-resolution = 7
suit-payload-fetch = 8
suit-install = 9
suit-validate = 10
suit-load = 11
suit-run = 12
suit-text-info = 13
suit-coswid = 14
Several fields in the Manifest can be either a CBOR structure or a
SUIT_Digest. In each of these cases, the SUIT_Digest provides for a
severable field. Severable fields are RECOMMENDED to implement. In
particular, text SHOULD be severable, since most useful text elements
occupy more space than a SUIT_Digest, but are not needed by recipient
devices. 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 suit-manifest-version indicates the version of serialisation used
to encode the manifest. Version 1 is the version described in this
document. suit-manifest-version is MANDATORY.
The suit-manifest-sequence-number is a monotonically increasing anti-
rollback counter. It also helps devices to determine which in a set
of manifests is the "root" manifest in a given update. Each manifest
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MUST have a sequence number higher than each of its dependencies.
Each recipient MUST reject any manifest that has a sequence number
lower than its current sequence number. It MAY be convenient to use
a UTC timestamp in seconds as the sequence number. suit-manifest-
sequence-number is MANDATORY.
suit-dependencies is a list of SUIT_Dependency blocks that specify
manifests that must be present before the current manifest can be
processed. suit-dependencies is OPTIONAL.
In order to distinguish between components that are affected by the
current manifest and components that are affected by a dependency,
they are kept in separate lists. Components affected by the current
manifest include the digest and size of the result. Components
affected by a manifest only include the component identifier and the
index of the manifest that fully defines the component.
suit-components is a list of SUIT_Component blocks that specify the
vital information about the content a component identifier should
contain following the update. These are the component identifiers
that will be affected by the content of the current manifest. suit-
components is OPTIONAL, but at least one manifest MUST contain a
suit-components block.
suit-dependency-components is a list of SUIT_Component_Reference
blocks that specify component identifiers that will be affected by
the content of a dependency of the current manifest. suit-dependency-
components is OPTIONAL.
suit-common is a SUIT_Command_Sequence to execute prior to executing
any other command sequence. Typical actions in suit-common include
setting expected device identity and image digests when they are
conditional (see Section 11 for more information on conditional
sequences). suit-common is OPTIONAL.
suit-dependency-resolution is a SUIT_Command_Sequence to execute in
order to perform dependency resolution. Typical actions include
configuring URIs of dependency manifests, fetching dependency
manifests, and validating dependency manifests' contents. suit-
dependency-resolution is MANDATORY when suit-dependencies is present.
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.
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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.
suit-validate is a SUIT_Command_Sequence to execute in order to
validate that the result of applying the update is correct. Typical
actions involve image validation and manifest validation. suit-
validate is MANDATORY. If the manifest contains dependencies, one
process-dependency invocation per dependency or one process-
dependency invocation targeting all dependencies SHOULD be present in
validate.
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.
suit-run is a SUIT_Command_Sequence to execute in order to run an
image. suit-run typically contains a single instruction: either the
"run" directive for the bootable manifest or the "process
dependencies" directive for any dependents of the bootable manifest.
suit-run is OPTIONAL. Only one manifest in an update may contain the
"run" directive.
suit-text-info is a digest that uniquely identifies the content of
the Text that is packaged in the OuterWrapper. text is OPTIONAL.
suit-coswid is a digest that uniquely identifies the content of the
concise-software-identifier that is packaged in the OuterWrapper.
coswid is OPTIONAL.
8.3. SUIT_Dependency
SUIT_Dependency specifies a manifest that describes a dependency of
the current manifest.
The following CDDL describes the SUIT_Dependency structure.
SUIT_Dependency = {
suit-dependency-digest => SUIT_Digest,
suit-dependency-prefix => SUIT_Component_Identifier,
}
The suit-dependency-digest specifies the dependency manifest uniquely
by identifying a particular Manifest structure. The digest is
calculated over the Manifest structure instead of the COSE
Sig_structure or Mac_structure. This means that a digest may need to
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be calculated more than once, however this is necessary to ensure
that removing a signature from a manifest does not break dependencies
due to missing 'body_protected' and 'body_signed' elements. This is
also necessary to support the trusted intermediary use case, where an
intermediary re-signs the Manifest, removing the original signature,
potentially with a different algorithm, or trading COSE_Sign for
COSE_Mac.
The suit-dependency-prefix element contains a
SUIT_Component_Identifier. This specifies the scope at which the
dependency operates. This allows the dependency to be forwarded on
to a component that is capable of parsing its own manifests. It also
allows one manifest to be deployed to multiple dependent devices
without those devices needing consistent component hierarchy. This
element is OPTIONAL.
8.4. SUIT_Component
The SUIT_Component describes an image that is uniquely defined by the
current manifest. It consists of three elemnts: the component
identifier that represents a component that will be affected by this
manifest. This excludes components that are affected by
dependencies. The following CDDL describes the SUIT_Component.
SUIT_Component = {
suit-component-identifier => SUIT_Component_Identifier,
? suit-component-size => uint,
? suit-component-digest => Digest,
}
Because suit-component-size and suit-component-digest can be
dependent on installation offset, they cannot be exclusively
contained in SUIT_Component. However, since these are security
critical parameters, these parameters are updated to match the
contents of suit-components prior to processing suit-common. If
absent, these are set to Zero and NULL, respectively. This enforces
that the manifest defining a component is the only manifest that can
describe its contents.
8.5. SUIT_Component_Reference
The SUIT_Component_Reference describes an image that is defined by
another manifest. This is useful for overriding the behaviour of
another manifest, for example by directing the recipient to look at a
different URI for the image or by changing the expected format, such
as when a gateway performs decryption on behalf of a constrained
device. The following CDDL describes the SUIT_Component_Reference.
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SUIT_Component_Reference = {
suit-component-identifier => SUIT_Component_Identifier,
suit-component-dependency-index => uint
}
8.6. Manifest Parameters
Many conditions and directives require additional information. That
information is contained within parameters that can be set in a
consistent way. Parameters MUST only be:
1. Integers
2. Byte strings
3. Booleans
This allows reduction of manifest size and replacement of parameters
from one manifest to the next. Byte strings MAY contain CBOR-encoded
objects.
The defined manifest parameters are described below.
+-------+-------+------+---------------+---------+------------------+
| Param | CBOR | Defa | Scope | Name | Description |
| eter | Type | ult | | | |
| Code | | | | | |
+-------+-------+------+---------------+---------+------------------+
| 1 | boole | 1 | Global | Strict | Requires that |
| | an | | | Order | the manifest is |
| | | | | | processed in a |
| | | | | | strictly linear |
| | | | | | fashion. Set to |
| | | | | | 0 to enable |
| | | | | | parallel |
| | | | | | handling of |
| | | | | | manifest |
| | | | | | directives. |
| | | | | | |
| 2 | boole | 0 | Global | Coerce | Coerces the |
| | an | | | Conditi | success code of |
| | | | | on | a command |
| | | | | Failure | segment to |
| | | | | | success even |
| | | | | | when aborted due |
| | | | | | to a condition |
| | | | | | failure. |
| | | | | | |
| 3 | bstr | nil | Component/Glo | Vendor | A RFC4122 UUID |
| | | | bal | ID | representing the |
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| | | | | | vendor of the |
| | | | | | device or |
| | | | | | component |
| | | | | | |
| 4 | bstr | nil | Component/Glo | Class | A RFC4122 UUID |
| | | | bal | ID | representing the |
| | | | | | class of the |
| | | | | | device or |
| | | | | | component |
| | | | | | |
| 5 | bstr | nil | Component/Glo | Device | A RFC4122 UUID |
| | | | bal | ID | representing the |
| | | | | | device or |
| | | | | | component |
| | | | | | |
| 6 | bstr | nil | Component/Dep | URI | A CBOR encoded |
| | | | endency | List | list of ranked |
| | | | | | URIs |
| | | | | | |
| 7 | bstr | nil | Component/Dep | Encrypt | A COSE object |
| | | | endency | ion | defining the |
| | | | | Info | encryption mode |
| | | | | | of the target |
| | | | | | |
| 8 | bstr | nil | Component | Compres | A SUIT_Compressi |
| | | | | sion | on_Info object |
| | | | | Info | |
| | | | | | |
| 9 | bstr | nil | Component | Unpack | A |
| | | | | Info | SUIT_Unpack_Info |
| | | | | | object |
| | | | | | |
| 10 | int/b | nil | Component | Source | A SUIT_Component |
| | str | | | Compone | _Identifier or |
| | | | | nt | Component Index |
| | | | | | |
| 11 | bstr | nil | Component/Dep | Image | A SUIT_Digest |
| | | | endency | Digest | |
| | | | | | |
| 12 | bstr | nil | Component/Dep | Image | Integer size |
| | | | endency | Size | |
| | | | | | |
| nint | int/b | nil | Custom | Custom | Application- |
| | str | | | Paramet | defined |
| | | | | er | parameter |
+-------+-------+------+---------------+---------+------------------+
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Each parameter contains a Skip/Append flag. Append is an advanced
feature that is not available on highly constrained platforms. The
mechanism for setting the Append flag is TBD.
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 modularisation and
division of responsibility within a pull parser. The same
consideration does not apply to Conditions and Directives because
those elements are invoked with their arguments immediately
8.6.1. 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
parallelise 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.
8.6.2. SUIT_Parameter_Coerce_Condition_Failure
When executing a command sequence inside SUIT_Run_Sequence and a
condition failure occurs, the manifest processor aborts the sequence.
If Coerce Condition Failure is True, it returns Success. Otherwise,
it returns the original condition failure.
SUIT_Parameter_Coerce_Condition_Failure is scoped to the enclosing
SUIT_Directive_Run_Sequence. Its value is discarded when
SUIT_Directive_Run_Sequence terminates.
8.7. SUIT_Parameter_Encryption_Info
Encryption Info defines the mechanism that Fetch or Copy should use
to decrypt the data they transfer. SUIT_Parameter_Encryption_Info is
encoded as a COSE_Encrypt_Tagged or a COSE_Encrypt0_Tagged, wrapped
in a bstr
8.8. SUIT_Parameter_Compression_Info
Compression Info defines any information that is required for a
device to perform decompression operations. Typically, this includes
the algorithm identifier.
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SUIT_Parameter_Compression_Info is defined by the following CDDL:
SUIT_Compression_Info = {
suit-compression-algorithm => SUIT_Compression_Algorithms
? suit-compression-parameters => bstr
}
suit-compression-algorithm = 1
suit-compression-parameters = 2
SUIT_Compression_Algorithms /= SUIT_Compression_Algorithm_gzip
SUIT_Compression_Algorithms /= SUIT_Compression_Algorithm_bzip2
SUIT_Compression_Algorithms /= SUIT_Compression_Algorithm_deflate
SUIT_Compression_Algorithms /= SUIT_Compression_Algorithm_LZ4
SUIT_Compression_Algorithms /= SUIT_Compression_Algorithm_lzma
SUIT_Compression_Algorithm_gzip = 1
SUIT_Compression_Algorithm_bzip2 = 2
SUIT_Compression_Algorithm_deflate = 3
SUIT_Compression_Algorithm_lz4 = 4
SUIT_Compression_Algorithm_lzma = 7
8.9. SUIT_Parameter_Unpack_Info
SUIT_Unpack_Info defines the information required for a device to
interpret a packed format, such as elf, hex, or binary diff.
SUIT_Unpack_Info is defined by the following CDDL:
SUIT_Unpack_Info = {
suit-unpack-algorithm => SUIT_Unpack_Algorithms
? suit-unpack-parameters => bstr
}
suit-unpack-algorithm = 1
suit-unpack-parameters = 2
SUIT_Unpack_Algorithms //= SUIT_Unpack_Algorithm_Delta
SUIT_Unpack_Algorithms //= SUIT_Unpack_Algorithm_Hex
SUIT_Unpack_Algorithms //= SUIT_Unpack_Algorithm_Elf
SUIT_Unpack_Algorithm_Delta = 1
SUIT_Unpack_Algorithm_Hex = 2
SUIT_Unpack_Algorithm_Elf = 3
8.10. SUIT_Parameters CDDL
The following CDDL describes all SUIT_Parameters.
SUIT_Parameters //= SUIT_Parameter_Strict_Order
SUIT_Parameters //= SUIT_Parameter_Coerce_Condition_Failure
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SUIT_Parameters //= SUIT_Parameter_Vendor_ID
SUIT_Parameters //= SUIT_Parameter_Class_ID
SUIT_Parameters //= SUIT_Parameter_Device_ID
SUIT_Parameters //= SUIT_Parameter_URI_List
SUIT_Parameters //= SUIT_Parameter_Encryption_Info
SUIT_Parameters //= SUIT_Parameter_Compression_Info
SUIT_Parameters //= SUIT_Parameter_Unpack_Info
SUIT_Parameters //= SUIT_Parameter_Source_Component
SUIT_Parameters //= SUIT_Parameter_Image_Digest
SUIT_Parameters //= SUIT_Parameter_Image_Size
SUIT_Parameters //= SUIT_Parameter_Custom
SUIT_Parameter_Strict_Order = (1 => bool)
SUIT_Parameter_Coerce_Condition_Failure = (2 => bool)
SUIT_Parameter_Vendor_ID = (3 => bstr)
SUIT_Parameter_Class_ID = (4 => bstr)
SUIT_Parameter_Device_ID = (5 => bstr)
SUIT_Parameter_URI_List = (6 => bstr .cbor SUIT_URI_List)
SUIT_Parameter_Encryption_Info = (7 => bstr .cbor SUIT_Encryption_Info)
SUIT_Parameter_Compression_Info = (8 => bstr .cbor SUIT_Compression_Info)
SUIT_Parameter_Unpack_Info = (9 => bstr .cbor SUIT_Unpack_Info)
SUIT_Parameter_Source_Component = (10 => bstr .cbor SUIT_Component_Identifier)
SUIT_Parameter_Image_Digest = (11 => bstr .cbor SUIT_Digest)
SUIT_Parameter_Image_Size = (12 => uint)
SUIT_Parameter_Custom = (nint => int/bool/bstr)
SUIT_URI_List = [ + [priority: int, uri: tstr] ]
SUIT_Encryption_Info= COSE_Encrypt_Tagged/COSE_Encrypt0_Tagged
SUIT_Compression_Info = {
suit-compression-algorithm => SUIT_Compression_Algorithms
? suit-compression-parameters => bstr
}
suit-compression-algorithm = 1
suit-compression-parameters = 2
SUIT_Compression_Algorithms /= SUIT_Compression_Algorithm_gzip
SUIT_Compression_Algorithms /= SUIT_Compression_Algorithm_bzip2
SUIT_Compression_Algorithms /= SUIT_Compression_Algorithm_deflate
SUIT_Compression_Algorithms /= SUIT_Compression_Algorithm_LZ4
SUIT_Compression_Algorithms /= SUIT_Compression_Algorithm_lzma
SUIT_Compression_Algorithm_gzip = 1
SUIT_Compression_Algorithm_bzip2 = 2
SUIT_Compression_Algorithm_deflate = 3
SUIT_Compression_Algorithm_lz4 = 4
SUIT_Compression_Algorithm_lzma = 7
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SUIT_Unpack_Info = {
suit-unpack-algorithm => SUIT_Unpack_Algorithms
? suit-unpack-parameters => bstr
}
suit-unpack-algorithm = 1
suit-unpack-parameters = 2
SUIT_Unpack_Algorithms //= SUIT_Unpack_Algorithm_Delta
SUIT_Unpack_Algorithms //= SUIT_Unpack_Algorithm_Hex
SUIT_Unpack_Algorithms //= SUIT_Unpack_Algorithm_Elf
SUIT_Unpack_Algorithm_Delta = 1
SUIT_Unpack_Algorithm_Hex = 2
SUIT_Unpack_Algorithm_Elf = 3
8.11. SUIT_Command_Sequence
A SUIT_Command_Sequence defines a series of actions that the
recipient MUST take to accomplish a particular goal. These goals are
defined in the manifest and include:
1. Dependency Resolution
2. Payload Fetch
3. Payload Installation
4. Image Validation
5. Image Loading
6. Run or Boot
Each of these 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-any failure is treated as a failure
of the update/load/boot
2. Directives that MUST be executed.
The lists of commands are logically structured into sequences of zero
or more conditions followed by zero or more directives. The
*logical* structure is described by the following CDDL:
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Command_Sequence = {
conditions => [ * Condition],
directives => [ * Directive]
}
This introduces significant complexity in the parser, however, so the
structure is flattened to make parsing simpler:
SUIT_Command_Sequence = [ + (SUIT_Condition/SUIT_Directive) ]
Each condition and directive is composed of:
1. A command code identifier
2. An argument block
Argument blocks are defined for each type of command.
Many conditions and directives apply to a given component, and these
generally grouped together. Therefore, a special command to set the
current component index is provided with a matching command to set
the current manifest index. This index is a numeric index into the
component ID tables defined at the beginning of the document. For
the purpose of setting the index, the two component ID tables are
considered to be concatenated together.
To facilitate optional conditions, a special directive is provided.
It runs a new list of conditions/directives that are contained as an
argument to the directive. It also contains a flag that indicates
whether or not a failure of a condition should indicate a failure of
the update/boot.
8.12. 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-conditons of any directive or series of directives, depending on
where they are placed in the list. Conditions include:
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+----------------+-------------------+------------------------------+
| Condition Code | Condition Name | Argument Type |
+----------------+-------------------+------------------------------+
| 1 | Vendor Identifier | RFC4122 UUID wrapped in a |
| | | bstr |
| | | |
| 2 | Class Identifier | RFC4122 UUID wrapped in a |
| | | bstr |
| | | |
| 3 | Device Identifier | RFC4122 UUID wrapped in a |
| | | bstr |
| | | |
| 4 | Image Match | SUIT_Digest |
| | | |
| 5 | Image Not Match | SUIT_Digest |
| | | |
| 6 | Use Before | Unsigned Integer timestamp |
| | | |
| 7 | Minimum Battery | Unsigned Integer |
| | | |
| 8 | Update Authorised | Integer |
| | | |
| 9 | Version | List of Integers |
| | | |
| 10 | Component Offset | Unsigned Integer |
| | | |
| nint | Custom Condition | bstr |
+----------------+-------------------+------------------------------+
Each condition MUST report a success code on completion. If a
condition reports failure, then the current sequence of commands MUST
terminate. If a recipient encounters an unknown Condition Code, it
MUST report a failure.
Positive Condition numbers are reserved for IANA registration.
Negative numbers are reserved for proprietary, application-specific
directives.
8.12.1. ID Conditions
There are three identifier-based conditions:
SUIT_Condition_Vendor_Identifier, SUIT_Condition_Class_Identifier,
and SUIT_Condition_Device_Identifier. Each of these conditions
present a RFC 4122 [RFC4122] UUID that MUST be matched by the
installing device in order to consider the manifest valid.
These conditions MAY be used with or without an argument. If an
argument is supplied, then it must be the RFC 4122 [RFC4122] UUID
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that must be matched for the condition to succeed. If no argument is
supplied, then 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 MANDATORY to implement.
SUIT_Condition_Device_Identifier is OPTIONAL to implement.
8.12.2. SUIT_Condition_Image_Match
Verify that the current component matches the supplied digest. If no
digest is specified, then the digest is verified against the digest
specified in the Components list. If no digest is specified and the
component is not present in the Components list, the condition fails.
SUIT_Condition_Image_Match is MANDATORY to implement.
8.12.3. SUIT_Condition_Image_Not_Match
Verify that the current component does not match the supplied digest.
If no digest is specified, then the digest is compared against the
digest specified in the Components list. If no digest is specified
and the component is not present in the Components list, the
condition fails. SUIT_Condition_Image_Not_Match is OPTIONAL to
implement.
8.12.4. SUIT_Condition_Use_Before
Verify that the current time is BEFORE the specified time.
SUIT_Condition_Use_Before is used to specify the last time at which
an update should be installed. One argument is required, encoded as
a POSIX timestamp, that is seconds after 1970-01-01 00:00:00.
Timestamp conditions MUST be evaluated in 64 bits, regardless of
encoded CBOR size. SUIT_Condition_Use_Before is OPTIONAL to
implement.
8.12.5. SUIT_Condition_Minimum_Battery
SUIT_Condition_Minimum_Battery provides a mechanism to test a
device's battery level before installing an update. This condition
is for use in primary-cell applications, where the battery is only
ever discharged. For batteries that are charged,
SUIT_Directive_Wait_Event is more appropriate, since it defines a
"wait" until the battery level is sufficient to install the update.
SUIT_Condition_Minimum_Battery is specified in mWh.
SUIT_Condition_Minimum_Battery is OPTIONAL to implement.
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8.12.6. SUIT_Condition_Update_Authorised
Request Authorisation from the application and fail if not
authorised. This can allow a user to decline an update. Argument is
an integer priority level. Priorities are application defined.
SUIT_Condition_Update_Authorised is OPTIONAL to implement.
8.12.7. SUIT_Condition_Version
SUIT_Condition_Version allows comparing versions of firmware.
Verifying image digests is preferred to version checks because
digests are more precise. The image can be compared as:
- Greater
- Greater or Equal
- Equal
- Lesser or Equal
- Lesser
Versions are encoded as a CBOR list of integers. Comparisons are
done on each integer in sequence.
The following CDDL describes SUIT_Condition_Version_Argument
SUIT_Condition_Version_Argument = [
suit-condition-version-comparison: SUIT_Condition_Version_Comparison_Types,
suit-condition-version-comparison: SUIT_Condition_Version_Comparison_Value
]
SUIT_Condition_Version_Comparison_Types /= SUIT_Condition_Version_Comparison_Greater
SUIT_Condition_Version_Comparison_Types /= SUIT_Condition_Version_Comparison_Greater_Equal
SUIT_Condition_Version_Comparison_Types /= SUIT_Condition_Version_Comparison_Equal
SUIT_Condition_Version_Comparison_Types /= SUIT_Condition_Version_Comparison_Lesser_Equal
SUIT_Condition_Version_Comparison_Types /= SUIT_Condition_Version_Comparison_Lesser
SUIT_Condition_Version_Comparison_Greater = 1
SUIT_Condition_Version_Comparison_Greater_Equal = 2
SUIT_Condition_Version_Comparison_Equal = 3
SUIT_Condition_Version_Comparison_Lesser_Equal = 4
SUIT_Condition_Version_Comparison_Lesser = 5
SUIT_Condition_Version_Comparison_Value = [+int]
While the exact encoding of versions is application-defined, semantic
versions map directly:
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- 1.2.3 = [1,2,3]
- 1.2-rc3 = [1,2,-1,3]
- 1.2-beta = [1,2,-2]
- 1.2-alpha = [1,2,-3]
- 1.2-alpha4 = [1,2,-3,4]
SUIT_Condition_Version is OPTIONAL to implement.
8.12.8. SUIT_Condition_Custom
SUIT_Condition_Custom describes any proprietary, application specific
condition. This is encoded as a negative integer, chosen by the
firmware developer, and a bstr that encodes the parameters passed to
the system that evaluates the condition matching that integer.
SUIT_Condition_Custom is OPTIONAL to implement.
8.12.9. Identifiers
Many conditions use identifiers to determine whether a manifest
matches a given recipient or not. These identifiers are defined to
be RFC 4122 [RFC4122] UUIDs. These UUIDs are explicitly NOT human-
readable. They are for machine-based matching only.
A device may match any number of UUIDs for vendor or class
identifier. This may be relevant to physical or software modules.
For example, a device 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 device might also have a Class ID
that must be matched for the OS and one or more Class IDs for the
applications.
A more complete example: A device has the following physical
components: 1. A host MCU 2. A WiFi module
This same device has three software modules: 1. An operating system
2. A WiFi module interface driver 3. An application
Suppose that the WiFi module's firmware has a proprietary update
mechanism and doesn't support manifest processing. This device can
report four class IDs:
1. hardware model/revision
2. OS
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3. WiFi module model/revision
4. Application
This allows the OS, WiFi module, and application to be updated
independently. To combat possible incompatibilities, the OS class ID
can be changed each time the OS has a change to its API.
This approach allows a vendor to target, for example, all devices
with a particular WiFi module with an update, which is a very
powerful mechanism, particularly when used for security updates.
8.12.9.1. Creating UUIDs:
UUIDs MUST be created according to RFC 4122 [RFC4122]. UUIDs SHOULD
use versions 3, 4, or 5, as described in RFC4122. Versions 1 and 2
do not provide a tangible benefit over version 4 for this
application.
The RECOMMENDED method to create a vendor ID is: Vendor ID =
UUID5(DNS_PREFIX, vendor domain name)
The RECOMMENDED method to create a class ID is: Class ID =
UUID5(Vendor ID, Class-Specific-Information)
Class-specific information is composed of a variety of data, for
example:
- Model number
- Hardware revision
- Bootloader version (for immutable bootloaders)
8.12.10. SUIT_Condition CDDL
The following CDDL describes SUIT_Condition:
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SUIT_Condition //= (nint => bstr)
SUIT_Condition //= SUIT_Condition_Vendor_Identifier
SUIT_Condition //= SUIT_Condition_Class_Identifier
SUIT_Condition //= SUIT_Condition_Device_Identifier
SUIT_Condition //= SUIT_Condition_Image_Match
SUIT_Condition //= SUIT_Condition_Image_Not_Match
SUIT_Condition //= SUIT_Condition_Use_Before
SUIT_Condition //= SUIT_Condition_Minimum_Battery
SUIT_Condition //= SUIT_Condition_Update_Authorised
SUIT_Condition //= SUIT_Condition_Version
SUIT_Condition //= SUIT_Condition_Component_Offset
SUIT_Condition //= SUIT_Condition_Custom
SUIT_Condition_Vendor_Identifier = (1 => bstr .size 16)
SUIT_Condition_Class_Identifier = (2 => bstr .size 16)
SUIT_Condition_Device_Identifier = (3 => bstr .size 16)
SUIT_Condition_Image_Match = (4 => SUIT_Digest)
SUIT_Condition_Image_Not_Match = (5 => SUIT_Digest)
SUIT_Condition_Use_Before = (6 => uint)
SUIT_Condition_Minimum_Battery = (7 => uint)
SUIT_Condition_Update_Authorised = (8 => int)
SUIT_Condition_Version = (9 => SUIT_Condition_Version_Argument)
SUIT_Condition_Component_Offset = (10 => uint)
SUIT_Condition_Custom = (nint => bstr)
SUIT_Condition_Version_Argument = [
suit-condition-version-comparison: SUIT_Condition_Version_Comparison_Types,
suit-condition-version-comparison: SUIT_Condition_Version_Comparison_Value
]
SUIT_Condition_Version_Comparison_Types /= SUIT_Condition_Version_Comparison_Greater
SUIT_Condition_Version_Comparison_Types /= SUIT_Condition_Version_Comparison_Greater_Equal
SUIT_Condition_Version_Comparison_Types /= SUIT_Condition_Version_Comparison_Equal
SUIT_Condition_Version_Comparison_Types /= SUIT_Condition_Version_Comparison_Lesser_Equal
SUIT_Condition_Version_Comparison_Types /= SUIT_Condition_Version_Comparison_Lesser
SUIT_Condition_Version_Comparison_Greater = 1
SUIT_Condition_Version_Comparison_Greater_Equal = 2
SUIT_Condition_Version_Comparison_Equal = 3
SUIT_Condition_Version_Comparison_Lesser_Equal = 4
SUIT_Condition_Version_Comparison_Lesser = 5
SUIT_Condition_Version_Comparison_Value = [+int]
8.13. SUIT_Directive
Directives are used to define the behaviour of the recipient.
Directives include:
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+----------------+--------------------------+
| Directive Code | Directive Name |
+----------------+--------------------------+
| 11 | Set Component Index |
| | |
| 12 | Set Manifest Index |
| | |
| 13 | Run Sequence |
| | |
| 14 | Run Sequence Conditional |
| | |
| 15 | Process Dependency |
| | |
| 16 | Set Parameters |
| | |
| 17 | Reserved |
| | |
| 18 | Reserved |
| | |
| 19 | Override Parameters |
| | |
| 20 | Fetch |
| | |
| 21 | Copy |
| | |
| 22 | Run |
| | |
| 23 | Wait |
+----------------+--------------------------+
When a Recipient executes a Directive, it MUST report a success code.
If the Directive reports failure, then the current Command Sequence
MUST terminate.
8.13.1. SUIT_Directive_Set_Component_Index
Set Component Index defines the component to which successive
directives and conditions will apply. The supplied argument MUST be
either a boolean or an unsigned integer index into the concatenation
of suit-components and suit-dependency-components. If the following
directives apply to ALL components, then the boolean value "True" is
used instead of an index. True does not apply to dependency
components. If the following directives apply to NO components, then
the boolean value "False" is used. When
SUIT_Directive_Set_Manifest_Index is used,
SUIT_Directive_Set_Component_Index = False is implied. When
SUIT_Directive_Set_Component_Index is used,
SUIT_Directive_Set_Manifest_Index = False is implied.
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The following CDDL describes the argument to
SUIT_Directive_Set_Component_Index.
SUIT_Directive_Set_Component_Index_Argument = uint/bool
8.13.2. SUIT_Directive_Set_Manifest_Index
Set Manifest Index defines the manifest to which successive
directives and conditions will apply. The supplied argument MUST be
either a boolean or an unsigned integer index into the dependencies.
If the following directives apply to ALL dependencies, then the
boolean value "True" is used instead of an index. If the following
directives apply to NO dependencies, then the boolean value "False"
is used. When SUIT_Directive_Set_Component_Index is used,
SUIT_Directive_Set_Manifest_Index = False is implied. When
SUIT_Directive_Set_Manifest_Index is used,
SUIT_Directive_Set_Component_Index = False is implied.
Typical operations that require SUIT_Directive_Set_Manifest_Index
include setting a source URI, invoking "Fetch," or invoking "Process
Dependency" for an individual dependency.
The following CDDL describes the argument to
SUIT_Directive_Set_Manifest_Index.
SUIT_Directive_Set_Manifest_Index_Argument = uint/bool
8.13.3. SUIT_Directive_Run_Sequence
To enable conditional commands, and to allow several strictly ordered
sequences to be executed out-of-order, SUIT_Run_Sequence allows the
manifest processor to execute its argument as a
SUIT_Command_Sequence. The argument must be wrapped in a bstr.
When a sequence is executed, any failure of a condition causes
immediate termination of the sequence.
The following CDDL describes the SUIT_Run_Sequence argument.
SUIT_Directive_Run_Sequence_Argument = bstr .cbor SUIT_Command_Sequence
When SUIT_Directive_Run_Sequence completes, it forwards the last
status code that occurred in the sequence. If the Coerce on
Condition Failure parameter is true, then SUIT_Directive_Run_Sequence
only fails when a directive in the argument sequence fails.
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SUIT_Parameter_Coerce_Condition_Failure defaults to False when
SUIT_Directive_Run_Sequence begins. Its value is discarded when
SUIT_Directive_Run_Sequence terminates.
8.13.4. SUIT_Directive_Run_Sequence_Conditional
This command is exactly the same as SUIT_Directive_Run_Sequence,
except that it initialises Coerce on Condition Failure to True.
SUIT_Parameter_Coerce_Condition_Failure defaults to True when
SUIT_Directive_Run_Sequence_Conditional begins. Its value is
discarded when SUIT_Directive_Run_Sequence_Conditional terminates.
8.13.5. SUIT_Directive_Process_Dependency
Execute the commands in the common section of the current dependency,
followed by the commands in the equivalent section of the current
dependency. For example, if the current section is "fetch payload,"
this will execute "common" in the current dependency, then "fetch
payload" in the current dependency. Once this is complete, the
command following SUIT_Directive_Process_Dependency will be
processed.
If the current dependency is False, this directive has no effect. If
the current dependency is True, then this directive applies to all
dependencies. If the current section is "common," this directive
MUST have no effect.
When SUIT_Process_Dependency completes, it forwards the last status
code that occurred in the dependency.
The argument to SUIT_Directive_Process_Dependency is defined in the
following CDDL.
SUIT_Directive_Process_Dependency_Argument = nil
8.13.6. SUIT_Directive_Set_Parameters
SUIT_Directive_Set_Parameters allows the manifest to configure
behaviour of future directives by changing parameters that are read
by those directives. When dependencies are used,
SUIT_Directive_Set_Parameters also allows a manifest to modify the
behaviour of its dependencies.
Available parameters are defined in Section 8.6.
If a parameter is already set, SUIT_Directive_Set_Parameters will
skip setting the parameter to its argument. This provides the core
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of the override mechanism, allowing dependent manifests to change the
behaviour of a manifest.
The argument to SUIT_Directive_Set_Parameters is defined in the
following CDDL.
SUIT_Directive_Set_Parameters_Argument = {+ SUIT_Parameters}
N.B.: A directive code is reserved for an optimisation: a way to set
a parameter to the contents of another parameter, optionally with
another component ID.
8.13.7. SUIT_Directive_Set_Parameter_State_Append
This command is reserved for future use. It will provide a mechanism
to override the "set if unset" logic of SUIT_Directive_Set_Parameters
on a per-parameter basis. This will allow certain parameters to be
treated as lists, rather than fixed values. This enables a feature
for an advanced device to fail over from URIs defined in one manifest
to those defined in another.
8.13.8. 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 8.6.
The argument to SUIT_Directive_Override_Parameters is defined in the
following CDDL.
SUIT_Directive_Override_Parameters_Argument = {+ SUIT_Parameters}
8.13.9. SUIT_Directive_Fetch
SUIT_Directive_Fetch instructs the manifest processor to obtain one
or more manifests or payloads, as specified by the manifest index and
component index, respectively.
SUIT_Directive_Fetch can target one or more manifests and one or more
payloads. SUIT_Directive_Fetch retrieves each component and each
manifest listed in component-index and manifest-index, respectively.
If component-index or manifest-index is True, instead of an integer,
then all current manifest components/manifests are fetched. The
current manifest's dependent-components are not automatically
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fetched. In order to pre-fetch these, they MUST be specified in a
component-index integer.
SUIT_Directive_Fetch typically takes no arguments unless one is
needed to modify fetch behaviour. If an argument is needed, it must
be wrapped in a bstr.
SUIT_Directive_Fetch reads the URI List parameter to find the source
of the fetch it performs.
The behaviour of SUIT_Directive_Fetch can be modified by setting one
or more of SUIT_Parameter_Encryption_Info,
SUIT_Parameter_Compression_Info, SUIT_Parameter_Unpack_Info. These
three parameters each activate and configure a processing step that
can be applied to the data that is transferred during
SUIT_Directive_Fetch.
The argument to SUIT_Directive_Fetch is defined in the following
CDDL.
SUIT_Directive_Fetch_Argument = nil/bstr
8.13.10. SUIT_Directive_Copy
SUIT_Directive_Copy instructs the manifest processor to obtain one or
more payloads, as specified by the component index.
SUIT_Directive_Copy retrieves each component listed in component-
index, respectively. If component-index is True, instead of an
integer, then all current manifest components are copied. The
current manifest's dependent-components are not automatically copied.
In order to copy these, they MUST be specified in a component-index
integer.
The behaviour of SUIT_Directive_Copy can be modified by setting one
or more of SUIT_Parameter_Encryption_Info,
SUIT_Parameter_Compression_Info, SUIT_Parameter_Unpack_Info. These
three parameters each activate and configure a processing step that
can be applied to the data that is transferred during
SUIT_Directive_Copy.
*N.B.* Fetch and Copy are very similar. Merging them into one
command may be appropriate.
SUIT_Directive_Copy reads its source from
SUIT_Parameter_Source_Component.
The argument to SUIT_Directive_Copy is defined in the following CDDL.
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SUIT_Directive_Copy_Argument = nil
8.13.11. SUIT_Directive_Run
SUIT_Directive_Run directs the manifest processor to transfer
execution to the current Component Index. When this is invoked, the
manifest processor MAY be unloaded and execution continues in the
Component Index. Arguments provided to Run 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.
The argument to SUIT_Directive_Run is defined in the following CDDL.
SUIT_Directive_Run_Argument = nil/bstr
8.13.12. SUIT_Directive_Wait
SUIT_Directive_Wait directs the manifest processor to pause until a
specified event occurs. Some possible events include:
1. Authorisation
2. External Power
3. Network availability
4. Other Device Firmware Version
5. Time
6. Time of Day
7. Day of Week
The following CDDL defines the encoding of these events.
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SUIT_Directive_Wait_Argument = {
SUIT_Wait_Events
}
SUIT_Wait_Events //= (1 => SUIT_Wait_Event_Argument_Authorisation)
SUIT_Wait_Events //= (2 => SUIT_Wait_Event_Argument_Power)
SUIT_Wait_Events //= (3 => SUIT_Wait_Event_Argument_Network)
SUIT_Wait_Events //= (4 => SUIT_Wait_Event_Argument_Other_Device_Version)
SUIT_Wait_Events //= (5 => SUIT_Wait_Event_Argument_Time)
SUIT_Wait_Events //= (6 => SUIT_Wait_Event_Argument_Time_Of_Day)
SUIT_Wait_Events //= (7 => SUIT_Wait_Event_Argument_Day_Of_Week)
SUIT_Wait_Event_Argument_Authorisation = int ; priority
SUIT_Wait_Event_Argument_Power = int ; Power Level
SUIT_Wait_Event_Argument_Network = int ; Network State
SUIT_Wait_Event_Argument_Other_Device_Version = [
other-device: bstr,
other-device-version: [+int]
]
SUIT_Wait_Event_Argument_Time = uint ; Timestamp
SUIT_Wait_Event_Argument_Time_Of_Day = uint ; Time of Day (seconds since 00:00:00)
SUIT_Wait_Event_Argument_Day_Of_Week = uint ; Days since Sunday
8.13.13. SUIT_Directive CDDL
The following CDDL describes SUIT_Directive:
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SUIT_Directive //= SUIT_Directive_Set_Component_Index
SUIT_Directive //= SUIT_Directive_Set_Manifest_Index
SUIT_Directive //= SUIT_Directive_Run_Sequence
SUIT_Directive //= SUIT_Directive_Run_Sequence_Conditional
SUIT_Directive //= SUIT_Directive_Process_Dependency
SUIT_Directive //= SUIT_Directive_Set_Parameters
SUIT_Directive //= SUIT_Directive_Override_Parameters
SUIT_Directive //= SUIT_Directive_Fetch
SUIT_Directive //= SUIT_Directive_Copy
SUIT_Directive //= SUIT_Directive_Run
SUIT_Directive //= SUIT_Directive_Wait
SUIT_Directive_Set_Component_Index = (11 => uint/bool)
SUIT_Directive_Set_Manifest_Index = (12 => uint/bool)
SUIT_Directive_Run_Sequence = (13 => bstr .cbor SUIT_Command_Sequence)
SUIT_Directive_Run_Sequence_Conditional = (14 => bstr .cbor SUIT_Command_Sequence)
SUIT_Directive_Process_Dependency = (15 => nil)
SUIT_Directive_Set_Parameters = (16 => {+ SUIT_Parameters})
SUIT_Directive_Override_Parameters = (19 => {+ SUIT_Parameters})
SUIT_Directive_Fetch = (20 => nil/bstr)
SUIT_Directive_Copy = (21 => nil/bstr)
SUIT_Directive_Run = (22 => nil/bstr)
SUIT_Directive_Wait = (23 => { + SUIT_Wait_Events })
SUIT_Wait_Events //= (1 => SUIT_Wait_Event_Argument_Authorisation)
SUIT_Wait_Events //= (2 => SUIT_Wait_Event_Argument_Power)
SUIT_Wait_Events //= (3 => SUIT_Wait_Event_Argument_Network)
SUIT_Wait_Events //= (4 => SUIT_Wait_Event_Argument_Other_Device_Version)
SUIT_Wait_Events //= (5 => SUIT_Wait_Event_Argument_Time)
SUIT_Wait_Events //= (6 => SUIT_Wait_Event_Argument_Time_Of_Day)
SUIT_Wait_Events //= (7 => SUIT_Wait_Event_Argument_Day_Of_Week)
SUIT_Wait_Event_Argument_Authorisation = int ; priority
SUIT_Wait_Event_Argument_Power = int ; Power Level
SUIT_Wait_Event_Argument_Network = int ; Network State
SUIT_Wait_Event_Argument_Other_Device_Version = [
other-device: bstr,
other-device-version: [+int]
]
SUIT_Wait_Event_Argument_Time = uint ; Timestamp
SUIT_Wait_Event_Argument_Time_Of_Day = uint ; Time of Day (seconds since 00:00:00)
SUIT_Wait_Event_Argument_Day_Of_Week = uint ; Days since Sunday
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9. Dependency processing
Dependencies need careful handling on constrained systems. A
dependency tree that is too deep can cause recursive handling to
overflow stack space. Systems that parse all dependencies into an
object tree can easily fill up available memory. Too many
dependencies can overrun available storage space.
The dependency handling system in this document is designed to
address as many of these problems as possible.
Dependencies MAY be addressed in one of three ways:
1. Iterate by component
2. Iterate by manifest
3. Out-of-order
Because each manifest has a list of components and a list of
components defined by its dependencies, it is possible for the
manifest processor to handle one component at a time, traversing the
manifest tree once for each listed component. This, however consumes
significant processing power.
Alternatively, it is possible for a device with sufficient memory to
accumulate all parameters for all listed component IDs. This will
naturally consume more memory, but it allows the device to process
the manifests in a single pass.
It is expected that the simplest and most power sensitive devices
will use option 2, with a fixed maximum number of components.
Advanced devices may make use of the Strict Order parameter and
enable parallel processing of some segments, or it may reorder some
segments. To perform parallel processing, once the Strict Order
parameter is set to False, the device may fork a process for each
command until the Strict Order parameter is returned to True or the
command sequence ends. Then, it joins all forked processes before
continuing processing of commands. To perform out-of-order
processing, a similar approach is used, except the device consumes
all commands after the Strict Order parameter is set to False, then
it sorts these commands into its prefered order, invokes them all,
then continues processing.
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10. Access Control Lists
To manage permissions in the manifest, there are three models that
can be used.
First, the simplest model requires that all manifests are
authenticated by a single trusted key. This mode has the advantage
that only a root manifest needs to be authenticated, since all of its
dependencies have digests included in the root manifest.
This simplest model can be extended by adding key delegation without
much increase in complexity.
A second model requires an ACL to be presented to the device,
authenticated by a trusted party or stored on the device. This ACL
grants access rights for specific component IDs or component ID
prefixes to the listed identities or identity groups. Any identity
may verify an image digest, but fetching into or fetching from a
component ID requires approval from the ACL.
A third model allows a device to provide even more fine-grained
controls: The ACL lists the component ID or component ID prefix that
an identity may use, and also lists the commands that the identity
may use in combination with that component ID.
11. Creating conditional sequences
For some use cases, it is important to provide a sequence that can
fail without terminating an update. For example, a dual-image XIP
MCU may require an update that can be placed at one of two offsets.
This has two implications, first, the digest of each offset will be
different. Second, the image fetched for each offset will have a
different URI. Conditional sequences allow this to be resolved in a
simple way.
The following JSON representation of a manifest demonstrates how this
would be represented. It assumes that the bootloader and manifest
processor take care of A/B switching and that the manifest is not
aware of this distinction.
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{
"structure-version" : 1,
"sequence-number" : 7,
"components" : [
{
"component-identifier" : [0],
"component-size" : [32567],
},
],
"common" : [
"set-component-index" : 0,
"do-sequence" : [
"condition-component-offset" : "<offset A>",
"set-parameters": {
"component-digest" : "<SHA256 A>"
}
],
"do-sequence" : [
"condition-component-offset" : "<offset B>",
"set-parameters": {
"component-digest" : "<SHA256 A>"
}
]
],
"fetch" : [
"set-component-index" : 0,
"do-sequence" : [
"condition-component-offset" : "<offset A>",
"set-parameters": {
"uri-list" : [[0, "<uri-A>"]]
}
],
"do-sequence" : [
"condition-component-offset" : "<offset B>",
"set-parameters": {
"uri-list" : [[0, "<uri-B>"]]
}
],
"fetch" : null
]
}
12. Full CDDL
In order to create a valid SUIT Manifest document the structure of
the corresponding CBOR message MUST adhere to the following CDDL data
definition.
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SUIT_Outer_Wrapper = {
suit-authentication-wrapper => bstr .cbor SUIT_Authentication_Wrapper / nil,
suit-manifest => bstr .cbor SUIT_Manifest,
suit-dependency-resolution => bstr .cbor SUIT_Command_Sequence,
suit-payload-fetch => bstr .cbor SUIT_Command_Sequence,
suit-install => bstr .cbor SUIT_Command_Sequence,
suit-text => bstr .cbor SUIT_Text_Map,
suit-coswid => bstr .cbor concise-software-identity
}
suit-authentication-wrapper = 1
suit-manifest = 2
suit-dependency-resolution = 7
suit-payload-fetch = 8
suit-install = 9
suit-text = 13
suit-coswid = 14
SUIT_Authentication_Wrapper = [ * (
COSE_Mac_Tagged /
COSE_Sign_Tagged /
COSE_Mac0_Tagged /
COSE_Sign1_Tagged)]
COSE_Mac_Tagged = any
COSE_Sign_Tagged = any
COSE_Mac0_Tagged = any
COSE_Sign1_Tagged = any
COSE_Encrypt_Tagged = any
COSE_Encrypt0_Tagged = any
SUIT_Digest = [
suit-digest-algorithm-id : $suit-digest-algorithm-ids,
suit-digest-bytes : bytes,
? suit-digest-parameters : any
]
; Named Information Hash Algorithm Identifiers
suit-digest-algorithm-ids /= algorithm-id-sha256
suit-digest-algorithm-ids /= algorithm-id-sha256-128
suit-digest-algorithm-ids /= algorithm-id-sha256-120
suit-digest-algorithm-ids /= algorithm-id-sha256-96
suit-digest-algorithm-ids /= algorithm-id-sha256-64
suit-digest-algorithm-ids /= algorithm-id-sha256-32
suit-digest-algorithm-ids /= algorithm-id-sha384
suit-digest-algorithm-ids /= algorithm-id-sha512
suit-digest-algorithm-ids /= algorithm-id-sha3-224
suit-digest-algorithm-ids /= algorithm-id-sha3-256
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suit-digest-algorithm-ids /= algorithm-id-sha3-384
suit-digest-algorithm-ids /= algorithm-id-sha3-512
SUIT_Manifest = {
suit-manifest-version => 1,
suit-manifest-sequence-number => uint,
? suit-dependencies => [ + SUIT_Dependency ],
? suit-components => [ + SUIT_Component ],
? suit-dependency-components => [ + SUIT_Component_Reference ],
? suit-common => bstr .cbor SUIT_Command_Sequence,
? suit-dependency-resolution => SUIT_Digest / bstr .cbor SUIT_Command_Sequence,
? suit-payload-fetch => SUIT_Digest / bstr .cbor SUIT_Command_Sequence,
? suit-install => SUIT_Digest / bstr .cbor SUIT_Command_Sequence
? suit-validate => bstr .cbor SUIT_Command_Sequence
? suit-load => bstr .cbor SUIT_Command_Sequence
? suit-run => bstr .cbor SUIT_Command_Sequence
? suit-text-info => SUIT_Digest / bstr .cbor SUIT_Text_Map
? suit-coswid => SUIT_Digest / bstr .cbor concise-software-identity
}
suit-manifest-version = 1
suit-manifest-sequence-number = 2
suit-dependencies = 3
suit-components = 4
suit-dependency-components = 5
suit-common = 6
suit-dependency-resolution = 7
suit-payload-fetch = 8
suit-install = 9
suit-validate = 10
suit-load = 11
suit-run = 12
suit-text-info = 13
suit-coswid = 14
concise-software-identity = any
SUIT_Dependency = {
suit-dependency-digest => SUIT_Digest,
suit-dependency-prefix => SUIT_Component_Identifier,
}
suit-dependency-digest = 1
suit-dependency-prefix = 2
SUIT_Component_Identifier = [* bstr]
SUIT_Component = {
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suit-component-identifier => SUIT_Component_Identifier,
? suit-component-size => uint,
? suit-component-digest => SUIT_Digest,
}
suit-component-identifier = 1
suit-component-size = 2
suit-component-digest = 3
SUIT_Component_Reference = {
suit-component-identifier => SUIT_Component_Identifier,
suit-component-dependency-index => uint
}
suit-component-dependency-index = 2
SUIT_Command_Sequence = [ + { SUIT_Condition // SUIT_Directive // SUIT_Command_Custom} ]
SUIT_Command_Custom = (nint => bstr)
SUIT_Condition //= (1 => RFC4122_UUID) ; SUIT_Condition_Vendor_Identifier
SUIT_Condition //= (2 => RFC4122_UUID) ; SUIT_Condition_Class_Identifier
SUIT_Condition //= (3 => RFC4122_UUID) ; SUIT_Condition_Device_Identifier
SUIT_Condition //= (4 => SUIT_Digest) ; SUIT_Condition_Image_Match
SUIT_Condition //= (5 => SUIT_Digest) ; SUIT_Condition_Image_Not_Match
SUIT_Condition //= (6 => uint) ; SUIT_Condition_Use_Before
SUIT_Condition //= (7 => uint) ; SUIT_Condition_Minimum_Battery
SUIT_Condition //= (8 => int) ; SUIT_Condition_Update_Authorised
SUIT_Condition //= (9 => SUIT_Condition_Version_Argument) ; SUIT_Condition_Version
SUIT_Condition //= (10 => uint) ; SUIT_Condition_Component_Offset
SUIT_Condition //= (nint => bstr) ; SUIT_Condition_Custom
RFC4122_UUID = bstr .size 16
SUIT_Condition_Version_Argument = [
suit-condition-version-comparison: SUIT_Condition_Version_Comparison_Types,
suit-condition-version-comparison: SUIT_Condition_Version_Comparison_Value
]
SUIT_Condition_Version_Comparison_Types /= SUIT_Condition_Version_Comparison_Greater
SUIT_Condition_Version_Comparison_Types /= SUIT_Condition_Version_Comparison_Greater_Equal
SUIT_Condition_Version_Comparison_Types /= SUIT_Condition_Version_Comparison_Equal
SUIT_Condition_Version_Comparison_Types /= SUIT_Condition_Version_Comparison_Lesser_Equal
SUIT_Condition_Version_Comparison_Types /= SUIT_Condition_Version_Comparison_Lesser
SUIT_Condition_Version_Comparison_Greater = 1
SUIT_Condition_Version_Comparison_Greater_Equal = 2
SUIT_Condition_Version_Comparison_Equal = 3
SUIT_Condition_Version_Comparison_Lesser_Equal = 4
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SUIT_Condition_Version_Comparison_Lesser = 5
SUIT_Condition_Version_Comparison_Value = [+int]
SUIT_Directive //= (11 => uint/bool) ; SUIT_Directive_Set_Component_Index
SUIT_Directive //= (12 => uint/bool) ; SUIT_Directive_Set_Manifest_Index
SUIT_Directive //= (13 => bstr .cbor SUIT_Command_Sequence) ; SUIT_Directive_Run_Sequence
SUIT_Directive //= (14 => bstr .cbor SUIT_Command_Sequence) ; SUIT_Directive_Run_Sequence_Conditional
SUIT_Directive //= (15 => nil) ; SUIT_Directive_Process_Dependency
SUIT_Directive //= (16 => {+ SUIT_Parameters}) ; SUIT_Directive_Set_Parameters
SUIT_Directive //= (19 => {+ SUIT_Parameters}) ; SUIT_Directive_Override_Parameters
SUIT_Directive //= (20 => nil/bstr) ; SUIT_Directive_Fetch
SUIT_Directive //= (21 => nil/bstr) ; SUIT_Directive_Copy
SUIT_Directive //= (22 => nil/bstr) ; SUIT_Directive_Run
SUIT_Directive //= (23 => { + SUIT_Wait_Events }) ; SUIT_Directive_Wait
SUIT_Wait_Events //= (1 => SUIT_Wait_Event_Argument_Authorisation)
SUIT_Wait_Events //= (2 => SUIT_Wait_Event_Argument_Power)
SUIT_Wait_Events //= (3 => SUIT_Wait_Event_Argument_Network)
SUIT_Wait_Events //= (4 => SUIT_Wait_Event_Argument_Other_Device_Version)
SUIT_Wait_Events //= (5 => SUIT_Wait_Event_Argument_Time)
SUIT_Wait_Events //= (6 => SUIT_Wait_Event_Argument_Time_Of_Day)
SUIT_Wait_Events //= (7 => SUIT_Wait_Event_Argument_Day_Of_Week)
SUIT_Wait_Event_Argument_Authorisation = int ; priority
SUIT_Wait_Event_Argument_Power = int ; Power Level
SUIT_Wait_Event_Argument_Network = int ; Network State
SUIT_Wait_Event_Argument_Other_Device_Version = [
other-device: bstr,
other-device-version: [+int]
]
SUIT_Wait_Event_Argument_Time = uint ; Timestamp
SUIT_Wait_Event_Argument_Time_Of_Day = uint ; Time of Day (seconds since 00:00:00)
SUIT_Wait_Event_Argument_Day_Of_Week = uint ; Days since Sunday
SUIT_Parameters //= (1 => bool) ; SUIT_Parameter_Strict_Order
SUIT_Parameters //= (2 => bool) ; SUIT_Parameter_Coerce_Condition_Failure
SUIT_Parameters //= (3 => bstr) ; SUIT_Parameter_Vendor_ID
SUIT_Parameters //= (4 => bstr) ; SUIT_Parameter_Class_ID
SUIT_Parameters //= (5 => bstr) ; SUIT_Parameter_Device_ID
SUIT_Parameters //= (6 => bstr .cbor SUIT_URI_List) ; SUIT_Parameter_URI_List
SUIT_Parameters //= (7 => bstr .cbor SUIT_Encryption_Info) ; SUIT_Parameter_Encryption_Info
SUIT_Parameters //= (8 => bstr .cbor SUIT_Compression_Info) ; SUIT_Parameter_Compression_Info
SUIT_Parameters //= (9 => bstr .cbor SUIT_Unpack_Info) ; SUIT_Parameter_Unpack_Info
SUIT_Parameters //= (10 => bstr .cbor SUIT_Component_Identifier) ; SUIT_Parameter_Source_Component
SUIT_Parameters //= (11 => bstr .cbor SUIT_Digest) ; SUIT_Parameter_Image_Digest
SUIT_Parameters //= (12 => uint) ; SUIT_Parameter_Image_Size
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SUIT_Parameters //= (nint => int/bool/bstr) ; SUIT_Parameter_Custom
SUIT_URI_List = [ + [priority: int, uri: tstr] ]
SUIT_Encryption_Info = COSE_Encrypt_Tagged/COSE_Encrypt0_Tagged
SUIT_Compression_Info = {
suit-compression-algorithm => SUIT_Compression_Algorithms
? suit-compression-parameters => bstr
}
suit-compression-algorithm = 1
suit-compression-parameters = 2
SUIT_Compression_Algorithms /= SUIT_Compression_Algorithm_gzip
SUIT_Compression_Algorithms /= SUIT_Compression_Algorithm_bzip2
SUIT_Compression_Algorithms /= SUIT_Compression_Algorithm_lz4
SUIT_Compression_Algorithms /= SUIT_Compression_Algorithm_lzma
SUIT_Compression_Algorithm_gzip = 1
SUIT_Compression_Algorithm_bzip2 = 2
SUIT_Compression_Algorithm_deflate = 3
SUIT_Compression_Algorithm_lz4 = 4
SUIT_Compression_Algorithm_lzma = 7
SUIT_Unpack_Info = {
suit-unpack-algorithm => SUIT_Unpack_Algorithms
? suit-unpack-parameters => bstr
}
suit-unpack-algorithm = 1
suit-unpack-parameters = 2
SUIT_Unpack_Algorithms /= SUIT_Unpack_Algorithm_Delta
SUIT_Unpack_Algorithms /= SUIT_Unpack_Algorithm_Hex
SUIT_Unpack_Algorithms /= SUIT_Unpack_Algorithm_Elf
SUIT_Unpack_Algorithm_Delta = 1
SUIT_Unpack_Algorithm_Hex = 2
SUIT_Unpack_Algorithm_Elf = 3
SUIT_Text_Map = {int => tstr}
13. Examples
The following examples demonstrate a small subset of the
functionality of the manifest. However, despite this, even a simple
manifest processor can execute most of these manifests.
None of these examples include authentication. This is provided via
RFC 8152 [RFC8152], and is omitted for clarity.
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13.1. Example 0:
Secure boot only.
The following JSON shows the intended behaviour of the manifest.
{
"structure-version": 1,
"sequence-number": 1,
"components": [
{
"id": ["Flash",78848],
"digest": "00112233445566778899aabbccddeeff"
"0123456789abcdeffedcba9876543210",
"size": 34768
}
],
"run-image": [
{"directive-set-component": 0},
{"condition-image": null},
{"directive-run": null}
]
}
Converted into the SUIT manifest, this produces:
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{
/ auth object / 1 : None
/ manifest / 2 : h'a4010102010481a3018245466c61736843003401021987'
h'd0038201582000112233445566778899aabbccddeeff0123456789abcdef'
h'fedcba98765432100c4a83a10b00a104f6a116f6' \
{
/ structure-version / 1 : 1
/ sequence-number / 2 : 1
/ components / 4 : [
{
/ component-identifier / 1 : [h'466c617368', h'003401'],
/ component-size / 3 : 34768
/ component-digest / 2 : [
/ sha-256 / 1,
h'00112233445566778899aabbccddeeff0123456789abcdef'
h'fedcba9876543210'],
}
],
/ run-image / 12 : [
{/ set-component-index / 11 : 0}
{/ condition-image / 4 : None}
{/ run / 22 : None}
],
}
}
Total size of outer wrapper without COSE authentication object: 79
Outer:
a201f6025849a4010102010481a3018245466c61736843003401021987d00382015820
00112233445566778899aabbccddeeff0123456789abcdeffedcba98765432100c4a83
a10b00a104f6a116f6
13.2. Example 1:
Simultaneous download and installation of payload.
The following JSON shows the intended behaviour of the manifest.
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{
"structure-version": 1,
"sequence-number": 2,
"components": [
{
"id": ["Flash",78848],
"digest": "00112233445566778899aabbccddeeff"
"0123456789abcdeffedcba9876543210",
"size": 34768
}
],
"apply-image": [
{"directive-set-component": 0},
{"directive-set-var": {
"uris": [[ 0, "http://example.com/file.bin"]]
}},
{"directive-fetch": null}
]
}
Converted into the SUIT manifest, this produces:
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{
/ auth object / 1 : None
/ manifest / 2 : h'a4010102020481a3018245466c61736843003401021987'
h'd0038201582000112233445566778899aabbccddeeff0123456789abcdef'
h'fedcba987654321009582d83a10b00a110a1065820818200781b68747470'
h'3a2f2f6578616d706c652e636f6d2f66696c652e62696ea114f6' \
{
/ structure-version / 1 : 1
/ sequence-number / 2 : 2
/ components / 4 : [
{
/ component-identifier / 1 : [h'466c617368', h'003401'],
/ component-size / 3 : 34768
/ component-digest / 2 : [
/ sha-256 / 1,
h'00112233445566778899aabbccddeeff'
h'0123456789abcdeffedcba9876543210'
],
}
],
/ apply-image / 9 : [
{/ set-component-index / 11 : 0}
{/ set-vars / 16 : {
/ uris / 6 : h'818200781b687474703a2f2f6578616d706c'
h'652e636f6d2f66696c652e62696e' /
[[0, 'http://example.com/file.bin']] /
}},
{/ fetch / 20 : None}
],
}
}
Total size of outer wrapper without COSE authentication object: 115
Outer:
a201f602586da4010102020481a3018245466c61736843003401021987d00382015820
00112233445566778899aabbccddeeff0123456789abcdeffedcba987654321009582d
83a10b00a110a1065820818200781b687474703a2f2f6578616d706c652e636f6d2f66
696c652e62696ea114f6
13.3. Example 2:
Compatibility test, simultaneous download and installation, and
secure boot.
The following JSON shows the intended behaviour of the manifest.
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{
"structure-version": 1,
"sequence-number": 3,
"components": [
{
"id": [
"Flash",
78848
],
"digest": "00112233445566778899aabbccddeeff"
"0123456789abcdeffedcba9876543210",
"size": 34768
}
],
"common": [
{"condition-vendor-id": "fa6b4a53-d5ad-5fdf-be9d-e663e4d41ffe"},
{"condition-class-id": "1492af14-2569-5e48-bf42-9b2d51f2ab45"}
],
"apply-image": [
{"directive-set-component": 0},
{"directive-set-var": {
"uris": [[ 0, "http://example.com/file.bin" ]]
}},
{"directive-fetch": null}
],
"run-image": [
{"directive-set-component": 0},
{"condition-image": null},
{"directive-run": null}
]
}
Converted into the SUIT manifest, this produces:
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{
/ auth object / 1 : None
/ manifest / 2 : h'a6010102030481a3018245466c61736843003401021987'
h'd0038201582000112233445566778899aabbccddeeff0123456789abcdef'
h'fedcba987654321006582782a10150fa6b4a53d5ad5fdfbe9de663e4d41f'
h'fea102501492af1425695e48bf429b2d51f2ab4509582d83a10b00a110a1'
h'065820818200781b687474703a2f2f6578616d706c652e636f6d2f66696c'
h'652e62696ea114f60c4a83a10b00a104f6a116f6' \
{
/ structure-version / 1 : 1
/ sequence-number / 2 : 3
/ components / 4 : [
{
/ component-identifier / 1 : [h'466c617368', h'003401'],
/ component-size / 3 : 34768
/ component-digest / 2 : [
/ sha-256 / 1,
h'00112233445566778899aabbccddeeff'
h'0123456789abcdeffedcba9876543210'
],
}
],
/ common / 6 : [
{/ vendor-id / 1 : h'fa6b4a53d5ad5fdfbe9de663e4d41ffe' \
fa6b4a53-d5ad-5fdf-be9d-e663e4d41ffe},
{/ class-id / 2 : h'1492af1425695e48bf429b2d51f2ab45' \
1492af14-2569-5e48-bf42-9b2d51f2ab45}
],
/ apply-image / 9 : [
{/ set-component-index / 11 : 0}
{/ set-vars / 16 : {
/ uris / 6 : h'818200781b687474703a2f2f6578616d706c65'
h'2e636f6d2f66696c652e62696e' /
[[0, 'http://example.com/file.bin']] /
}},
{/ fetch / 20 : None}
],
/ run-image / 12 : [
{/ set-component-index / 11 : 0}
{/ condition-image / 4 : None}
{/ run / 22 : None}
],
}
}
Total size of outer wrapper without COSE authentication object: 169
Outer:
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a201f60258a3a6010102030481a3018245466c61736843003401021987d00382015820
00112233445566778899aabbccddeeff0123456789abcdeffedcba9876543210065827
82a10150fa6b4a53d5ad5fdfbe9de663e4d41ffea102501492af1425695e48bf429b2d
51f2ab4509582d83a10b00a110a1065820818200781b687474703a2f2f6578616d706c
652e636f6d2f66696c652e62696ea114f60c4a83a10b00a104f6a116f6
13.4. Example 3:
Compatibility test, simultaneous download and installation, load from
external storage, and secure boot.
The following JSON shows the intended behaviour of the manifest.
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{
"structure-version": 1,
"sequence-number": 4,
"components": [
{
"id": ["Flash",78848],
"digest": "00112233445566778899aabbccddeeff"
"0123456789abcdeffedcba9876543210",
"size": 34768
},
{
"id": ["RAM",1024],
"digest": "00112233445566778899aabbccddeeff"
"0123456789abcdeffedcba9876543210",
"size": 34768
}
],
"common": [
{"condition-vendor-id": "fa6b4a53-d5ad-5fdf-be9d-e663e4d41ffe"},
{"condition-class-id": "1492af14-2569-5e48-bf42-9b2d51f2ab45"}
],
"apply-image": [
{"directive-set-component": 0},
{"directive-set-var": {
"uris": [[0, "http://example.com/file.bin"]]
}},
{"directive-fetch": null}
],
"run-image": [
{"directive-set-component": 0},
{"condition-image": null},
{"directive-set-component": 1},
{"directive-set-var": {
"source-index": 0
}},
{"directive-fetch": null},
{"condition-image": null},
{"directive-run": null}
]
}
Converted into the SUIT manifest, this produces:
{
/ auth object / 1 : None
/ manifest / 2 : h'a6010102040482a3018245466c61736843003401021987'
h'd0038201582000112233445566778899aabbccddeeff0123456789abcdef'
h'fedcba9876543210a301824352414d420004021987d00382015820001122'
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h'33445566778899aabbccddeeff0123456789abcdeffedcba987654321006'
h'582782a10150fa6b4a53d5ad5fdfbe9de663e4d41ffea102501492af1425'
h'695e48bf429b2d51f2ab4509582d83a10b00a110a1065820818200781b68'
h'7474703a2f2f6578616d706c652e636f6d2f66696c652e62696ea114f60c'
h'581887a10b00a104f6a10b01a110a10a00a114f6a104f6a116f6' \
{
/ structure-version / 1 : 1
/ sequence-number / 2 : 4
/ components / 4 : [
{
/ component-identifier / 1 : [h'466c617368', h'003401'],
/ component-size / 3 : 34768
/ component-digest / 2 : [
/ sha-256 / 1,
h'00112233445566778899aabbccddeeff'
h'0123456789abcdeffedcba9876543210'
],
},
{
/ component-identifier / 1 : [h'52414d', h'0004'],
/ component-size / 3 : 34768
/ component-digest / 2 : [
/ sha-256 / 1,
h'00112233445566778899aabbccddeeff'
h'0123456789abcdeffedcba9876543210'
],
}
],
/ common / 6 : [
{/ vendor-id / 1 : h'fa6b4a53d5ad5fdfbe9de663e4d41ffe' \
fa6b4a53-d5ad-5fdf-be9d-e663e4d41ffe}
{/ class-id / 2 : h'1492af1425695e48bf429b2d51f2ab45' \
1492af14-2569-5e48-bf42-9b2d51f2ab45}
],
/ apply-image / 9 : [
{/ set-component-index / 11 : 0}
{/ set-vars / 16 : {
/ uris / 6 : h'818200781b687474703a2f2f6578616d706c65'
h'2e636f6d2f66696c652e62696e' /
[[0, 'http://example.com/file.bin']] /
}},
{/ fetch / 20 : None}
],
/ run-image / 12 : [
{/ set-component-index / 11 : 0}
{/ condition-image / 4 : None}
{/ set-component-index / 11 : 1}
{/ set-vars / 16 : {
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/ source-component / 10 : 0
}},
{/ fetch / 20 : None}
{/ condition-image / 4 : None}
{/ run / 22 : None}
],
}
}
Total size of outer wrapper without COSE authentication object: 235
Outer:
a201f60258e5a6010102040482a3018245466c61736843003401021987d00382015820
00112233445566778899aabbccddeeff0123456789abcdeffedcba9876543210a30182
4352414d420004021987d0038201582000112233445566778899aabbccddeeff012345
6789abcdeffedcba987654321006582782a10150fa6b4a53d5ad5fdfbe9de663e4d41f
fea102501492af1425695e48bf429b2d51f2ab4509582d83a10b00a110a10658208182
00781b687474703a2f2f6578616d706c652e636f6d2f66696c652e62696ea114f60c58
1887a10b00a104f6a10b01a110a10a00a114f6a104f6a116f6
13.5. Example 4:
Compatibility test, simultaneous download and installation, load and
decompress from external storage, and secure boot.
The following JSON shows the intended behaviour of the manifest.
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{
"structure-version": 1,
"sequence-number": 5,
"components": [
{
"id": ["Flash",78848],
"digest": "00112233445566778899aabbccddeeff"
"0123456789abcdeffedcba9876543210",
"size": 34768
},
{
"id": ["RAM",1024],
"digest": "0123456789abcdeffedcba9876543210"
"00112233445566778899aabbccddeeff",
"size": 34768
}
],
"common": [
{"condition-vendor-id": "fa6b4a53-d5ad-5fdf-be9d-e663e4d41ffe"},
{"condition-class-id": "1492af14-2569-5e48-bf42-9b2d51f2ab45"}
],
"apply-image": [
{"directive-set-component": 0},
{"directive-set-var": {
"uris": [[ 0, "http://example.com/file.bin" ]]
}},
{"directive-fetch": null}
],
"load-image": [
{"directive-set-component": 0},
{"condition-image": null},
{"directive-set-component": 1},
{"directive-set-var": {
"source-index": 0,
"compression-info": {
"algorithm": "gzip"
}
}},
{"directive-copy": null}
],
"run-image": [
{"condition-image": null},
{"directive-run": null}
]
}
Converted into the SUIT manifest, this produces:
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{
/ auth object / 1 : None
/ manifest / 2 : h'a7010102050482a3018245466c61736843003401021987'
h'd0038201582000112233445566778899aabbccddeeff0123456789abcdef'
h'fedcba9876543210a301824352414d420004021987d00382015820012345'
h'6789abcdeffedcba987654321000112233445566778899aabbccddeeff06'
h'582782a10150fa6b4a53d5ad5fdfbe9de663e4d41ffea102501492af1425'
h'695e48bf429b2d51f2ab4509582d83a10b00a110a1065820818200781b68'
h'7474703a2f2f6578616d706c652e636f6d2f66696c652e62696ea114f60b'
h'5585a10b00a104f6a10b01a110a20841f60a00a115f60c4782a104f6a116'
h'f6' \
{
/ structure-version / 1 : 1
/ sequence-number / 2 : 5
/ components / 4 : [
{
/ component-identifier / 1 : [h'466c617368', h'003401'],
/ component-size / 3 : 34768
/ component-digest / 2 : [
/ sha-256 / 1,
h'00112233445566778899aabbccddeeff'
h'0123456789abcdeffedcba9876543210'
],
},
{
/ component-identifier / 1 : [h'52414d', h'0004'],
/ component-size / 3 : 34768
/ component-digest / 2 : [
/ sha-256 / 1,
h'0123456789abcdeffedcba9876543210'
h'00112233445566778899aabbccddeeff'
],
}
],
/ common / 6 : [
{/ vendor-id / 1 : h'fa6b4a53d5ad5fdfbe9de663e4d41ffe' \
fa6b4a53-d5ad-5fdf-be9d-e663e4d41ffe},
{/ class-id / 2 : h'1492af1425695e48bf429b2d51f2ab45' \
1492af14-2569-5e48-bf42-9b2d51f2ab45}
],
/ apply-image / 9 : [
{/ set-component-index / 11 : 0}
{/ set-vars / 16 : {
/ uris / 6 : h'818200781b687474703a2f2f6578616d706c65'
h'2e636f6d2f66696c652e62696e' /
[[0, 'http://example.com/file.bin']] /
}},
{/ fetch / 20 : None}
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],
/ load-image / 11 : [
{/ set-component-index / 11 : 0}
{/ condition-image / 4 : None}
{/ set-component-index / 11 : 1}
{/ set-vars / 16 : {
/ unknown / 8 : b'\xf6'
/ source-component / 10 : 0
}},
{/ copy / 21 : None}
],
/ run-image / 12 : [
{/ condition-image / 4 : None}
{/ run / 22 : None}
],
}
}
Total size of outer wrapper without COSE authentication object: 240
Outer:
a201f60258eaa7010102050482a3018245466c61736843003401021987d00382015820
00112233445566778899aabbccddeeff0123456789abcdeffedcba9876543210a30182
4352414d420004021987d003820158200123456789abcdeffedcba9876543210001122
33445566778899aabbccddeeff06582782a10150fa6b4a53d5ad5fdfbe9de663e4d41f
fea102501492af1425695e48bf429b2d51f2ab4509582d83a10b00a110a10658208182
00781b687474703a2f2f6578616d706c652e636f6d2f66696c652e62696ea114f60b55
85a10b00a104f6a10b01a110a20841f60a00a115f60c4782a104f6a116f6
13.6. Example 5:
Compatibility test, download, installation, and secure boot.
The following JSON shows the intended behaviour of the manifest.
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{
"structure-version": 1,
"sequence-number": 6,
"components": [
{
"id": [ "ext-Flash", 78848 ],
"digest": "00112233445566778899aabbccddeeff"
"0123456789abcdeffedcba9876543210",
"size": 34768
},
{
"id": ["Flash",1024],
"digest": "0123456789abcdeffedcba9876543210"
"00112233445566778899aabbccddeeff",
"size": 34768
}
],
"common": [
{"condition-vendor-id": "fa6b4a53-d5ad-5fdf-be9d-e663e4d41ffe"},
{"condition-class-id": "1492af14-2569-5e48-bf42-9b2d51f2ab45"}
],
"apply-image": [
{"directive-set-component": 0},
{"directive-set-var": {
"uris": [[0, "http://example.com/file.bin"]]
}},
{"directive-fetch": null}
],
"load-image": [
{"directive-run-conditional": [
{"directive-set-component": 1},
{"condition-not-image": null},
{"directive-set-component": 0},
{"condition-image": null},
{"directive-set-component": 1},
{"directive-set-var": {
"source-index": 0
}},
{"directive-fetch": null}
]}
],
"run-image": [
{"directive-set-component": 1},
{"condition-image": null},
{"directive-run": null}
]
}
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Converted into the SUIT manifest, this produces:
{
/ auth object / 1 : None
/ manifest / 2 : h'a7010102060482a30182496578742d466c617368430034'
h'01021987d0038201582000112233445566778899aabbccddeeff01234567'
h'89abcdeffedcba9876543210a3018245466c617368420004021987d00382'
h'0158200123456789abcdeffedcba987654321000112233445566778899aa'
h'bbccddeeff06582782a10150fa6b4a53d5ad5fdfbe9de663e4d41ffea102'
h'501492af1425695e48bf429b2d51f2ab4509582d83a10b00a110a1065820'
h'818200781b687474703a2f2f6578616d706c652e636f6d2f66696c652e62'
h'696ea114f60b581d81a10e581887a10b01a105f6a10b00a104f6a10b01a1'
h'10a10a00a114f60c4a83a10b01a104f6a116f6' \
{
/ structure-version / 1 : 1
/ sequence-number / 2 : 6
/ components / 4 : [
{
/ component-identifier / 1 : [
h'6578742d466c617368',
h'003401'
],
/ component-size / 3 : 34768
/ component-digest / 2 : [
/ sha-256 / 1,
h'00112233445566778899aabbccddeeff'
h'0123456789abcdeffedcba9876543210'
],
}
{
/ component-identifier / 1 : [h'466c617368', h'0004'],
/ component-size / 3 : 34768
/ component-digest / 2 : [
/ sha-256 / 1,
h'0123456789abcdeffedcba9876543210'
h'00112233445566778899aabbccddeeff'
],
}
],
/ common / 6 : [
{/ vendor-id / 1 : h'fa6b4a53d5ad5fdfbe9de663e4d41ffe' \
fa6b4a53-d5ad-5fdf-be9d-e663e4d41ffe}
{/ class-id / 2 : h'1492af1425695e48bf429b2d51f2ab45' \
1492af14-2569-5e48-bf42-9b2d51f2ab45}
],
/ apply-image / 9 : [
{/ set-component-index / 11 : 0}
{/ set-vars / 16 : {
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/ uris / 6 : h'818200781b687474703a2f2f6578616d706c65'
h'2e636f6d2f66696c652e62696e' /
[[0, 'http://example.com/file.bin']] /
}},
{/ fetch / 20 : None}
],
/ load-image / 11 : [
/ conditional-sequence / 14 : [
{/ set-component-index / 11 : 1}
{/ condition-not-image / 5 : None}
{/ set-component-index / 11 : 0}
{/ condition-image / 4 : None}
{/ set-component-index / 11 : 1}
{/ set-vars / 16 : {
/ source-component / 10 : 0
}},
{/ fetch / 20 : None}
],
],
/ run-image / 12 : [
{/ set-component-index / 11 : 1}
{/ condition-image / 4 : None}
{/ run / 22 : None}
],
}
}
Total size of outer wrapper without COSE authentication object: 258
Outer:
a201f60258fca7010102060482a30182496578742d466c61736843003401021987d003
8201582000112233445566778899aabbccddeeff0123456789abcdeffedcba98765432
10a3018245466c617368420004021987d003820158200123456789abcdeffedcba9876
54321000112233445566778899aabbccddeeff06582782a10150fa6b4a53d5ad5fdfbe
9de663e4d41ffea102501492af1425695e48bf429b2d51f2ab4509582d83a10b00a110
a1065820818200781b687474703a2f2f6578616d706c652e636f6d2f66696c652e6269
6ea114f60b581d81a10e581887a10b01a105f6a10b00a104f6a10b01a110a10a00a114
f60c4a83a10b01a104f6a116f6
13.7. Example 6:
Compatibility test, 2 images, simultaneous download and installation,
and secure boot.
The following JSON shows the intended behaviour of the manifest.
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{
"structure-version": 1,
"sequence-number": 7,
"components": [
{
"id": ["Flash",78848],
"digest": "00112233445566778899aabbccddeeff"
"0123456789abcdeffedcba9876543210",
"size": 34768
},
{
"id": ["Flash",132096],
"digest": "0123456789abcdeffedcba9876543210"
"00112233445566778899aabbccddeeff",
"size": 76834
}
],
"common": [
{"condition-vendor-id": "fa6b4a53-d5ad-5fdf-be9d-e663e4d41ffe"},
{"condition-class-id": "1492af14-2569-5e48-bf42-9b2d51f2ab45"}
],
"apply-image": [
{"directive-set-component": 0},
{"directive-set-var": {
"uris": [[ 0, "http://example.com/file1.bin" ]]
}},
{"directive-set-component": 1},
{"directive-set-var": {
"uris": [[ 0, "http://example.com/file2.bin" ]]
}},
{"directive-set-component": true},
{"directive-fetch": null}
],
"run-image": [
{"directive-set-component": true},
{"condition-image": null},
{"directive-set-component": 0},
{"directive-run": null}
]
}
Converted into the SUIT manifest, this produces:
{
/ auth object / 1 : None
/ manifest / 2 : h'a6010102070482a3018245466c61736843003401021987'
h'd0038201582000112233445566778899aabbccddeeff0123456789abcdef'
h'fedcba9876543210a3018245466c61736843000402021a00012c22038201'
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h'58200123456789abcdeffedcba987654321000112233445566778899aabb'
h'ccddeeff06582782a10150fa6b4a53d5ad5fdfbe9de663e4d41ffea10250'
h'1492af1425695e48bf429b2d51f2ab4509585b86a10b00a110a106582181'
h'8200781c687474703a2f2f6578616d706c652e636f6d2f66696c65312e62'
h'696ea10b01a110a1065821818200781c687474703a2f2f6578616d706c65'
h'2e636f6d2f66696c65322e62696ea10bf5a114f60c4d84a10bf5a104f6a1'
h'0b00a116f6' \
{
/ structure-version / 1 : 1
/ sequence-number / 2 : 7
/ components / 4 : [
{
/ component-identifier / 1 : [h'466c617368', h'003401'],
/ component-size / 3 : 34768
/ component-digest / 2 : [
/ sha-256 / 1,
h'00112233445566778899aabbccddeeff'
h'0123456789abcdeffedcba9876543210'
],
}
{
/ component-identifier / 1 : [h'466c617368', h'000402'],
/ component-size / 3 : 76834
/ component-digest / 2 : [
/ sha-256 / 1,
h'0123456789abcdeffedcba9876543210'
h'00112233445566778899aabbccddeeff'
],
}
],
/ common / 6 : [
{/ vendor-id / 1 : h'fa6b4a53d5ad5fdfbe9de663e4d41ffe' \
fa6b4a53-d5ad-5fdf-be9d-e663e4d41ffe}
{/ class-id / 2 : h'1492af1425695e48bf429b2d51f2ab45' \
1492af14-2569-5e48-bf42-9b2d51f2ab45}
],
/ apply-image / 9 : [
{/ set-component-index / 11 : 0}
{/ set-vars / 16 : {
/ uris / 6 : h'818200781c687474703a2f2f6578616d706c'
h'652e636f6d2f66696c65312e62696e' /
[[0, 'http://example.com/file1.bin']] /
}},
{/ set-component-index / 11 : 1}
{/ set-vars / 16 : {
/ uris / 6 : h'818200781c687474703a2f2f6578616d706c
h'652e636f6d2f66696c65322e62696e' /
[[0, 'http://example.com/file2.bin']] /
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}},
{/ set-component-index / 11 : True}
{/ fetch / 20 : None}
],
/ run-image / 12 : [
{/ set-component-index / 11 : True}
{/ condition-image / 4 : None}
{/ set-component-index / 11 : 0}
{/ run / 22 : None}
],
}
}
Total size of outer wrapper without COSE authentication object: 275
Outer:
a201f60259010ca6010102070482a3018245466c61736843003401021987d003820158
2000112233445566778899aabbccddeeff0123456789abcdeffedcba9876543210a301
8245466c61736843000402021a00012c2203820158200123456789abcdeffedcba9876
54321000112233445566778899aabbccddeeff06582782a10150fa6b4a53d5ad5fdfbe
9de663e4d41ffea102501492af1425695e48bf429b2d51f2ab4509585b86a10b00a110
a1065821818200781c687474703a2f2f6578616d706c652e636f6d2f66696c65312e62
696ea10b01a110a1065821818200781c687474703a2f2f6578616d706c652e636f6d2f
66696c65322e62696ea10bf5a114f60c4d84a10bf5a104f6a10b00a116f6
14. IANA Considerations
Several registries will be required for:
- standard Commands
- standard Parameters
- standard Algorithm identifiers
- standard text values
15. Security Considerations
This document is about a manifest format describing and protecting
firmware images and as such it is part of a larger solution for
offering a standardized way of delivering firmware updates to IoT
devices. A more detailed discussion about security can be found in
the architecture document [Architecture] and in [Information].
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16. Mailing List Information
The discussion list for this document is located at the e-mail
address suit@ietf.org [1]. Information on the group and information
on how to subscribe to the list is at
https://www1.ietf.org/mailman/listinfo/suit [2]
Archives of the list can be found at: https://www.ietf.org/mail-
archive/web/suit/current/index.html [3]
17. Acknowledgements
We would like to thank the following persons for their support in
designing this mechanism:
- Milosch Meriac
- Geraint Luff
- Dan Ros
- John-Paul Stanford
- Hugo Vincent
- Carsten Bormann
- Oeyvind Roenningstad
- Frank Audun Kvamtroe
- Krzysztof Chruściński
- Andrzej Puzdrowski
- Michael Richardson
- David Brown
- Emmanuel Baccelli
18. References
18.1. Normative References
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[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/info/rfc2119>.
[RFC4122] Leach, P., Mealling, M., and R. Salz, "A Universally
Unique IDentifier (UUID) URN Namespace", RFC 4122,
DOI 10.17487/RFC4122, July 2005,
<https://www.rfc-editor.org/info/rfc4122>.
[RFC8152] Schaad, J., "CBOR Object Signing and Encryption (COSE)",
RFC 8152, DOI 10.17487/RFC8152, July 2017,
<https://www.rfc-editor.org/info/rfc8152>.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
May 2017, <https://www.rfc-editor.org/info/rfc8174>.
18.2. Informative References
[Architecture]
Moran, B., "A Firmware Update Architecture for Internet of
Things Devices", January 2019,
<https://tools.ietf.org/html/
draft-ietf-suit-architecture-02>.
[Behaviour]
Moran, B., "An Information Model for Behavioural
Description of Firmware Update and Related Operations",
March 2019, <https://datatracker.ietf.org/doc/
draft-moran-suit-behavioural-manifest/>.
[Information]
Moran, B., "Firmware Updates for Internet of Things
Devices - An Information Model for Manifests", January
2019, <https://tools.ietf.org/html/
draft-ietf-suit-information-model-02>.
[RFC6920] Farrell, S., Kutscher, D., Dannewitz, C., Ohlman, B.,
Keranen, A., and P. Hallam-Baker, "Naming Things with
Hashes", RFC 6920, DOI 10.17487/RFC6920, April 2013,
<https://www.rfc-editor.org/info/rfc6920>.
18.3. URIs
[1] mailto:suit@ietf.org
[2] https://www1.ietf.org/mailman/listinfo/suit
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[3] https://www.ietf.org/mail-archive/web/suit/current/index.html
Authors' Addresses
Brendan Moran
Arm Limited
EMail: Brendan.Moran@arm.com
Hannes Tschofenig
Arm Limited
EMail: hannes.tschofenig@arm.com
Henk Birkholz
Fraunhofer SIT
EMail: henk.birkholz@sit.fraunhofer.de
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