SUIT B. Moran
Internet-Draft H. Tschofenig
Intended status: Informational Arm Limited
Expires: January 9, 2020 H. Birkholz
Fraunhofer SIT
July 08, 2019
SUIT CBOR manifest serialisation format
draft-moran-suit-manifest-05
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
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and may be updated, replaced, or obsoleted by other documents at any
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This Internet-Draft will expire on January 9, 2020.
Copyright Notice
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Conventions and Terminology . . . . . . . . . . . . . . . . . 4
3. Distributing firmware . . . . . . . . . . . . . . . . . . . . 5
4. Workflow of a device applying a firmware update . . . . . . . 5
5. SUIT manifest goals . . . . . . . . . . . . . . . . . . . . . 6
6. SUIT manifest design overview . . . . . . . . . . . . . . . . 7
6.1. Manifest Design Evaluation . . . . . . . . . . . . . . . 8
6.2. Severable Elements . . . . . . . . . . . . . . . . . . . 9
6.3. Conventions . . . . . . . . . . . . . . . . . . . . . . . 9
6.4. Payloads . . . . . . . . . . . . . . . . . . . . . . . . 9
7. Manifest Structure . . . . . . . . . . . . . . . . . . . . . 10
7.1. Outer wrapper . . . . . . . . . . . . . . . . . . . . . . 11
7.2. Manifest . . . . . . . . . . . . . . . . . . . . . . . . 13
7.3. SUIT_Dependency . . . . . . . . . . . . . . . . . . . . . 16
7.4. SUIT_Component_Reference . . . . . . . . . . . . . . . . 17
7.5. Manifest Parameters . . . . . . . . . . . . . . . . . . . 17
7.5.1. SUIT_Parameter_Strict_Order . . . . . . . . . . . . . 19
7.5.2. SUIT_Parameter_Coerce_Condition_Failure . . . . . . . 20
7.6. SUIT_Parameter_Encryption_Info . . . . . . . . . . . . . 20
7.7. SUIT_Parameter_Compression_Info . . . . . . . . . . . . . 20
7.8. SUIT_Parameter_Unpack_Info . . . . . . . . . . . . . . . 20
7.9. SUIT_Parameters CDDL . . . . . . . . . . . . . . . . . . 21
7.10. SUIT_Command_Sequence . . . . . . . . . . . . . . . . . . 22
7.11. SUIT_Condition . . . . . . . . . . . . . . . . . . . . . 24
7.11.1. Identifier Conditions . . . . . . . . . . . . . . . 25
7.11.2. suit-condition-image-match . . . . . . . . . . . . . 25
7.11.3. suit-condition-image-not-match . . . . . . . . . . . 25
7.11.4. suit-condition-use-before . . . . . . . . . . . . . 25
7.11.5. suit-condition-minimum-battery . . . . . . . . . . . 25
7.11.6. suit-condition-update-authorised . . . . . . . . . . 26
7.11.7. suit-condition-version . . . . . . . . . . . . . . . 26
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7.11.8. SUIT_Condition_Custom . . . . . . . . . . . . . . . 27
7.11.9. Identifiers . . . . . . . . . . . . . . . . . . . . 27
7.11.10. SUIT_Condition CDDL . . . . . . . . . . . . . . . . 29
7.12. SUIT_Directive . . . . . . . . . . . . . . . . . . . . . 29
7.12.1. suit-directive-set-component-index . . . . . . . . . 30
7.12.2. suit-directive-set-dependency-index . . . . . . . . 31
7.12.3. suit-directive-abort . . . . . . . . . . . . . . . . 31
7.12.4. suit-directive-run-sequence . . . . . . . . . . . . 31
7.12.5. suit-directive-try-each . . . . . . . . . . . . . . 32
7.12.6. suit-directive-process-dependency . . . . . . . . . 32
7.12.7. suit-directive-set-parameters . . . . . . . . . . . 33
7.12.8. suit-directive-override-parameters . . . . . . . . . 33
7.12.9. suit-directive-fetch . . . . . . . . . . . . . . . . 34
7.12.10. suit-directive-copy . . . . . . . . . . . . . . . . 34
7.12.11. suit-directive-swap . . . . . . . . . . . . . . . . 35
7.12.12. suit-directive-run . . . . . . . . . . . . . . . . . 35
7.12.13. suit-directive-wait . . . . . . . . . . . . . . . . 36
7.12.14. SUIT_Directive CDDL . . . . . . . . . . . . . . . . 37
8. Dependency processing . . . . . . . . . . . . . . . . . . . . 39
9. Access Control Lists . . . . . . . . . . . . . . . . . . . . 40
10. SUIT digest container . . . . . . . . . . . . . . . . . . . . 40
11. Creating conditional sequences . . . . . . . . . . . . . . . 41
12. Full CDDL . . . . . . . . . . . . . . . . . . . . . . . . . . 43
13. Examples . . . . . . . . . . . . . . . . . . . . . . . . . . 48
13.1. Example 0: . . . . . . . . . . . . . . . . . . . . . . . 48
13.2. Example 1: . . . . . . . . . . . . . . . . . . . . . . . 49
13.3. Example 2: . . . . . . . . . . . . . . . . . . . . . . . 52
13.4. Example 3: . . . . . . . . . . . . . . . . . . . . . . . 54
13.5. Example 4: . . . . . . . . . . . . . . . . . . . . . . . 57
13.6. Example 5: . . . . . . . . . . . . . . . . . . . . . . . 61
13.7. Example 6: . . . . . . . . . . . . . . . . . . . . . . . 65
14. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 68
15. Security Considerations . . . . . . . . . . . . . . . . . . . 68
16. Mailing List Information . . . . . . . . . . . . . . . . . . 69
17. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 69
18. References . . . . . . . . . . . . . . . . . . . . . . . . . 69
18.1. Normative References . . . . . . . . . . . . . . . . . . 69
18.2. Informative References . . . . . . . . . . . . . . . . . 70
18.3. URIs . . . . . . . . . . . . . . . . . . . . . . . . . . 70
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 71
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
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devices. Equally important is the inclusion of meta-data about the
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].
The SUIT manifest is heavily optimised for consumption by constrained
devices. This means that it is not constructed as a conventional
descriptive document. Instead, of describing what an update IS, it
describes what a recipient should DO.
While the SUIT manifest is informed by and optimised for firmware
update use cases, there is nothing in the [Information] that
restricts its use to only firmware use cases. Software update and
delivery of arbitrary data can equally be managed by SUIT-based
metadata.
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.
- Trusted Execution: A process by which a system ensures that only
trusted code is executed, for example secure boot.
3. 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].
4. 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:
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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.
5. SUIT manifest goals
The manifest described in this document is intended to meet several
goals, as described below.
1. Meet the requirements defined in [Information].
2. Simple to parse on a constrained node
3. Simple to process on a constrained node
4. Compact encoding
5. Comprehensible by an intermediate system
6. Expressive enough to enable advanced use cases on advanced nodes
7. Extensible
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.
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8. the device to reason about the installation of a firmware.
9. the device to reason about the authenticity & encoding of a
firmware at boot.
Each of these uses happens at a different stage of the manifest
lifecycle, so each has different requirements.
6. 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 encodes the required behaviour of a Recipient
device. Behaviour is encoded as a specialised byte code, contained
in a CBOR list. This promotes a flat encoding, which simplifies the
parser. The information encoded by this byte code closely matches
the operations that a device will perform, which promotes ease of
processing. The core operations used by most update and trusted
execution operations are represented in the byte code. The byte code
can be extended by registering new operations.
The specialised byte code approach gives benefits equivalent to those
provided by a scripting language or conventional byte code, with two
substantial differences. First, the language is extremely high
level, consisting of only the operations that a device may perform
during update and trusted execution of a firmware image. Second, the
language specifies behaviours in a linearised form, without reverse
branches. Conditional processing is supported, and parallel and out-
of-order processing may be performed by sufficiently capable devices.
By structuring the data in this way, the manifest processor becomes a
very simple engine that uses a pull parser to interpret the manifest.
This pull parser invokes a series of command handlers that evaluate a
Condition or execute a Directive. Most data is structured in a
highly regular pattern, which simplifies the parser.
The results of this allow a Recipient to implement a very small
parser for constrained applications. If needed, such a parser also
allows the Recipient to perform complex updates with reduced
overhead. Conditional execution of commands allows a simple device
to perform important decisions at validation-time.
Dependency handling is vastly simplified as well. Dependencies
function like subroutines of the language. When a manifest has a
dependency, it can invoke that dependency's commands and modify their
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.
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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 operate on a
component.
Capability reporting is similarly simplified. A Recipient can report
the Commands, Parameters, Algorithms, and Component Identifiers that
it supports. This is sufficiently precise for a manifest author to
create a manifest that the Recipient can accept.
The simplicity of design in the Recipient due to all of these
benefits allows even a highly constrained platform to use advanced
update capabilities.
6.1. Manifest Design Evaluation
To evaluate this design, it is compared to the goals stated above.
Goal evaluation:
1. Each command and condition is anchored to a manifest information
element in [Information]
2. The use of a byte code encourages flat encoding and reduces
nesting depth. This promotes a simple encoding.
3. The encoded information closely matches the operations that a
device will perform, making the format easy to process.
4. Encoding efficiency exceeds 50% when compared to raw data.
5. Tooling will be required to reason about the manifest.
6. The core operations used by most update and trusted execution
operations are represented in the byte code. The use cases
listed in [Information] are enabled.
7. Registration of new standard byte code identifiers enables
extension in a comprehensible way.
The manifest described by this document meets the stated goals.
Meeting goal 5-comprehensible by intermediate systems-will require
additional tooling or a division of metadata.
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6.2. 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.
6.3. 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.
6.4. 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, and serialised
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configuration require installation-time unpacking. Elf may or may
not require unpacking depending on the target.
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_Parameter_Image_Digest by indicating a SUIT_Digest
algorithm that correctly validates their information.
7. Manifest Structure
The manifest is divided into several sections in a hierarchy as
follows:
1. The outer wrapper
1. The authentication wrapper
2. The manifest
1. Critical Information
2. Information shared by all command sequences
1. List of dependencies
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2. List of payloads
3. List of payloads in dependencies
4. Common list of conditions, directives
3. Dependency resolution Reference or list of conditions,
directives
4. Payload fetch Reference or list of conditions,
directives
5. Installation Reference or list of conditions, directives
6. Verification conditions/directives
7. Load conditions/directives
8. Run conditions/directives
9. Text / Reference
10. 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. Inline Payload(s)
7.1. 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
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SUIT_Outer_Wrapper = {
suit-authentication-wrapper => bstr .cbor
SUIT_Authentication_Wrapper / nil,
$SUIT_Manifest_Wrapped,
? 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 = [ + (COSE_Mac_Tagged / COSE_Sign_Tagged /
COSE_Mac0_Tagged / COSE_Sign1_Tagged)]
SUIT_Encryption_Wrapper = COSE_Encrypt_Tagged / COSE_Encrypt0_Tagged
SUIT_Manifest_Wrapped //= (suit-manifest => bstr .cbor SUIT_Manifest)
SUIT_Manifest_Wrapped //= (
suit-manifest-encryption-info => bstr .cbor SUIT_Encryption_Wrapper,
suit-manifest-encrypted => bstr
)
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.
A manifest that has not had authentication information added MUST
still contain the suit-authentication-wrapper element, but the
content MUST be nil.
The outer wrapper MUST contain only one of
- a plaintext manifest: SUIT_Manifest
- an encrypted manifest: both a SUIT_Encryption_Wrapper and the
ciphertext of a manifest.
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When the outer wrapper contains SUIT_Encryption_Wrapper, the suit-
authentication-wrapper MUST authenticate the plaintext of suit-
manifest-encrypted.
suit-manifest contains a SUIT_Manifest structure, which describes the
payload(s) to be installed and any dependencies on other manifests.
suit-manifest-encryption-info contains a SUIT_Encryption_Wrapper, a
COSE object that describes the information required to decrypt a
ciphertext manifest.
suit-manifest-encrypted contains a ciphertext manifest.
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 7.2.
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.
7.2. 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-common => bstr .cbor SUIT_Common,
? 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_Common = {
? suit-dependencies => bstr .cbor [ + SUIT_Dependency ],
? suit-components => bstr .cbor [ + SUIT_Component_Identifier ],
? suit-dependency-components => bstr .cbor [ + SUIT_Component_Reference ],
? suit-common-sequence => bstr .cbor SUIT_Command_Sequence,
}
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 is been severable. The key used for a
severable element is the same in the SUIT_Manifest and in the
SUIT_Outer_Wrapper so that a recipient can easily identify the
correct data in the outer wrapper.
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 REQUIRED.
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
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 REQUIRED.
suit-common encodes all the information that is shared between each
of the command sequences, including: suit-dependencies, suit-
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components, suit-dependency-components, and suit-common-sequence.
suit-common is REQUIRED to implement.
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 to implement.
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 only list the component identifier. Components affected by
a dependency include the component identifier and the index of the
dependency that defines the component.
suit-components is a list of SUIT_Component blocks that specify 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-sequence is a SUIT_Command_Sequence to execute prior to
executing any other command sequence. Typical actions in suit-
common-sequence include setting expected device identity and image
digests when they are conditional (see Section 11 for more
information on conditional sequences). suit-common-sequence is
RECOMMENDED.
suit-dependency-resolution is a SUIT_Command_Sequence to execute in
order to perform dependency resolution. Typical actions include
configuring URIs of dependency manifests, fetching dependency
manifests, and validating dependency manifests' contents. suit-
dependency-resolution is REQUIRED 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.
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.
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suit-validate is a SUIT_Command_Sequence to execute in order to
validate that the result of applying the update is correct. Typical
actions involve image validation and manifest validation. suit-
validate is REQUIRED. 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.
7.3. 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
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 signature elements. This is also necessary to support
the trusted intermediary use case, where an intermediary re-signs the
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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.
7.4. 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.
SUIT_Component_Reference = {
suit-component-identifier => SUIT_Component_Identifier,
suit-component-dependency-index => uint
}
7.5. 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.
+--------+-------+------+---------------+----------+----------------+
| Parame | CBOR | Defa | Scope | Name | Description |
| ter | Type | ult | | | |
| Code | | | | | |
+--------+-------+------+---------------+----------+----------------+
| 1 | boole | True | Global | Strict | Requires that |
| | an | | | Order | the manifest |
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| | | | | | is processed |
| | | | | | in a strictly |
| | | | | | linear |
| | | | | | fashion. Set |
| | | | | | to 0 to enable |
| | | | | | parallel |
| | | | | | handling of |
| | | | | | manifest |
| | | | | | directives. |
| | | | | | |
| 2 | boole | Fals | Command | Coerce C | Coerces the |
| | an | e | Segment | ondition | success code |
| | | | | Failure | of a command |
| | | | | | segment to |
| | | | | | success even |
| | | | | | when aborted |
| | | | | | due to a |
| | | | | | condition |
| | | | | | failure. |
| | | | | | |
| 3 | bstr | nil | Component/Glo | Vendor | A RFC4122 UUID |
| | | | bal | ID | representing |
| | | | | | the vendor of |
| | | | | | the device or |
| | | | | | component |
| | | | | | |
| 4 | bstr | nil | Component/Glo | Class ID | A RFC4122 UUID |
| | | | bal | | 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 URI from |
| | | | endency | | which to fetch |
| | | | | | a resource |
| | | | | | |
| 7 | bstr | nil | Component/Dep | Encrypti | A COSE object |
| | | | endency | on Info | defining the |
| | | | | | encryption |
| | | | | | mode of a |
| | | | | | resource |
| | | | | | |
| 8 | bstr | nil | Component | Compress | A SUIT_Compres |
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| | | | | ion Info | sion_Info |
| | | | | | object |
| | | | | | |
| 9 | bstr | nil | Component | Unpack | A SUIT_Unpack_ |
| | | | | Info | Info object |
| | | | | | |
| 10 | uint | nil | Component | Source C | A Component |
| | | | | omponent | Index |
| | | | | | |
| 11 | bstr | nil | Component/Dep | Image | A SUIT_Digest |
| | | | endency | Digest | |
| | | | | | |
| 12 | bstr | nil | Component/Dep | Image | Integer size |
| | | | endency | Size | |
| | | | | | |
| 24 | bstr | nil | Component/Dep | URI List | A CBOR encoded |
| | | | endency | | list of ranked |
| | | | | | URIs |
| | | | | | |
| 25 | boole | Fals | Component/Dep | URI List | A CBOR encoded |
| | an | e | endency | Append | list of ranked |
| | | | | | URIs |
| | | | | | |
| nint | int/b | nil | Custom | Custom P | Application- |
| | str | | | arameter | defined |
| | | | | | parameter |
+--------+-------+------+---------------+----------+----------------+
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
7.5.1. 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
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returned to True, ALL preceding commands MUST complete before the
next command is executed.
7.5.2. 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.
7.6. 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
7.7. 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.
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_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
7.8. 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:
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SUIT_Unpack_Info = {
suit-unpack-algorithm => SUIT_Unpack_Algorithms
? suit-unpack-parameters => bstr
}
SUIT_Unpack_Algorithms //= SUIT_Unpack_Algorithm_Delta
SUIT_Unpack_Algorithms //= SUIT_Unpack_Algorithm_Hex
SUIT_Unpack_Algorithms //= SUIT_Unpack_Algorithm_Elf
7.9. SUIT_Parameters CDDL
The following CDDL describes all SUIT_Parameters.
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SUIT_Parameters //= (suit-parameter-strict-order => bool)
SUIT_Parameters //= (suit-parameter-coerce-condition-failure => bool)
SUIT_Parameters //= (suit-parameter-vendor-id => bstr)
SUIT_Parameters //= (suit-parameter-class-id => bstr)
SUIT_Parameters //= (suit-parameter-device-id => bstr)
SUIT_Parameters //= (suit-parameter-uri => bstr)
SUIT_Parameters //= (suit-parameter-encryption-info => bstr .cbor SUIT_Encryption_Info)
SUIT_Parameters //= (suit-parameter-compression-info => bstr .cbor SUIT_Compression_Info)
SUIT_Parameters //= (suit-parameter-unpack-info => bstr .cbor SUIT_Unpack_Info)
SUIT_Parameters //= (suit-parameter-source-component => bstr .cbor SUIT_Component_Identifier)
SUIT_Parameters //= (suit-parameter-image-digest => bstr .cbor SUIT_Digest)
SUIT_Parameters //= (suit-parameter-image-size => uint)
SUIT_Parameters //= (suit-parameter-uri-list => bstr .cbor SUIT_URI_List)
SUIT_Parameters //= (suit-parameter_custom => 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_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_Unpack_Info = {
suit-unpack-algorithm => SUIT_Unpack_Algorithms
? suit-unpack-parameters => bstr
}
SUIT_Unpack_Algorithms //= SUIT_Unpack_Algorithm_Delta
SUIT_Unpack_Algorithms //= SUIT_Unpack_Algorithm_Hex
SUIT_Unpack_Algorithms //= SUIT_Unpack_Algorithm_Elf
7.10. 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
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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:
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 dependency 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.
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To facilitate optional conditions, a special directive is provided.
It runs several new lists of conditions/directives, one after
another, that are contained as an argument to the directive. By
default, it assumes that a failure of a condition should not indicate
a failure of the update/boot, but a parameter is provided to override
this behaviour.
7.11. 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:
+----------------+-------------------+----------------------------+
| Condition Code | Condition Name | Argument Type |
+----------------+-------------------+----------------------------+
| 1 | Vendor Identifier | nil |
| | | |
| 2 | Class Identifier | nil |
| | | |
| 3 | Image Match | nil |
| | | |
| 4 | Use Before | Unsigned Integer timestamp |
| | | |
| 5 | Component Offset | Unsigned Integer |
| | | |
| 24 | Device Identifier | nil |
| | | |
| 25 | Image Not Match | nil |
| | | |
| 26 | Minimum Battery | Unsigned Integer |
| | | |
| 27 | Update Authorised | Integer |
| | | |
| 28 | Version | List of Integers |
| | | |
| 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.
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7.11.1. Identifier Conditions
There are three identifier-based conditions: suit-condition-vendor-
identifier, suit-condition-class-identifier, and suit-condition-
device-identifier. Each of these conditions match a RFC 4122
[RFC4122] UUID that MUST have already been set as a parameter. The
installing device MUST match the specified UUID in order to consider
the manifest valid. These identifiers MAY be scoped by component.
The recipient uses the ID parameter that has already been set using
the Set Parameters directive. If no ID has been set, this condition
fails. suit-condition-class-identifier and suit-condition-vendor-
identifier are REQUIRED to implement. suit-condition-device-
identifier is OPTIONAL to implement.
7.11.2. suit-condition-image-match
Verify that the current component matches the digest parameter for
the current component. The digest is verified against the digest
specified in the Component's parameters list. If no digest is
specified, the condition fails. suit-condition-image-match is
REQUIRED to implement.
7.11.3. 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.
7.11.4. 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.
7.11.5. 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
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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.
7.11.6. 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.
7.11.7. 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. Comparison stops after all
integers in the list defined by the manifest have been consumed OR
after a non-equal match has occured. For example, if the manifest
defines a comparison, "Equal [1]", then this will match all version
sequences starting with 1. If a manifest defines both "Greater or
Equal [1,0]" and "Lesser [1,10]", then it will match versions 1.0.x
up to, but not including 1.10.
The following CDDL describes SUIT_Condition_Version_Argument
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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 conveniently. For example,
- 1.2.3 = [1,2,3]
- 1.2-rc3 = [1,2,-1,3]
- 1.2-beta = [1,2,-2]
- 1.2-alpha = [1,2,-3]
- 1.2-alpha4 = [1,2,-3,4]
suit-condition-version is OPTIONAL to implement.
7.11.8. 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.
7.11.9. 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.
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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
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.
7.11.9.1. 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)
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Class-specific information is composed of a variety of data, for
example:
- Model number
- Hardware revision
- Bootloader version (for immutable bootloaders)
7.11.10. SUIT_Condition CDDL
The following CDDL describes SUIT_Condition:
SUIT_Condition //= (suit-condition-vendor-identifier, nil)
SUIT_Condition //= (suit-condition-class-identifier, nil)
SUIT_Condition //= (suit-condition-device-identifier, nil)
SUIT_Condition //= (suit-condition-image-match, nil)
SUIT_Condition //= (suit-condition-image-not-match, nil)
SUIT_Condition //= (suit-condition-use-before, uint)
SUIT_Condition //= (suit-condition-minimum-battery, uint)
SUIT_Condition //= (suit-condition-update-authorised, int)
SUIT_Condition //= (suit-condition-version, SUIT_Condition_Version_Argument)
SUIT_Condition //= (suit-condition-component-offset, uint)
SUIT_Condition //= (suit-condition-custom, 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_Value = [+int]
7.12. SUIT_Directive
Directives are used to define the behaviour of the recipient.
Directives include:
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+----------------+----------------------+
| Directive Code | Directive Name |
+----------------+----------------------+
| 12 | Set Component Index |
| | |
| 13 | Set Dependency Index |
| | |
| 14 | Abort |
| | |
| 15 | Try Each |
| | |
| 16 | Reserved |
| | |
| 17 | Reserved |
| | |
| 18 | Process Dependency |
| | |
| 19 | Set Parameters |
| | |
| 20 | Override Parameters |
| | |
| 21 | Fetch |
| | |
| 22 | Copy |
| | |
| 23 | Run |
| | |
| 29 | Wait |
| | |
| 30 | Run Sequence |
| | |
| 31 | Run with Arguments |
| | |
| 32 | Swap |
+----------------+----------------------+
When a Recipient executes a Directive, it MUST report a success code.
If the Directive reports failure, then the current Command Sequence
MUST terminate.
7.12.1. 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
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components. If the following directives apply to NO components, then
the boolean value "False" is used. When suit-directive-set-
dependency-index is used, suit-directive-set-component-index = False
is implied. When suit-directive-set-component-index is used, suit-
directive-set-dependency-index = False is implied.
The following CDDL describes the argument to suit-directive-set-
component-index.
SUIT_Directive_Set_Component_Index_Argument = uint/bool
7.12.2. suit-directive-set-dependency-index
Set Dependency Index defines the manifest to which successive
directives and conditions will apply. The supplied argument MUST be
either a boolean or an unsigned integer index into the dependencies.
If the following directives apply to ALL dependencies, then the
boolean value "True" is used instead of an index. If the following
directives apply to NO dependencies, then the boolean value "False"
is used. When suit-directive-set-component-index is used, suit-
directive-set-dependency-index = False is implied. When suit-
directive-set-dependency-index is used, suit-directive-set-component-
index = False is implied.
Typical operations that require suit-directive-set-dependency-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-
dependency-index.
SUIT_Directive_Set_Manifest_Index_Argument = uint/bool
7.12.3. suit-directive-abort
Unconditionally fail. This operation is typically used in
conjunction with suit-directive-try-each.
7.12.4. suit-directive-run-sequence
To enable conditional commands, and to allow several strictly ordered
sequences to be executed out-of-order, suit-directive-run-sequence
allows the manifest processor to execute its argument as a
SUIT_Command_Sequence. The argument must be wrapped in a bstr.
When a sequence is executed, any failure of a condition causes
immediate termination of the sequence.
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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.
SUIT_Parameter_Coerce_Condition_Failure defaults to False when suit-
directive-run-sequence begins. Its value is discarded when suit-
directive-run-sequence terminates.
7.12.5. suit-directive-try-each
This command runs several suit-directive-run-sequence one after
another, in a strict order. Use this command to implement a "try/
catch-try/catch" sequence. Manifest processors MAY implement this
command.
SUIT_Parameter_Coerce_Condition_Failure is initialised to True at the
beginning of each sequence. If one sequence aborts due to a
condition failure, the next is started. If no sequence completes
without condition failure, then suit-directive-try-each returns an
error. If a particular application calls for all sequences to fail
and still continue, then an empty sequence (nil) can be added to the
Try Each Argument.
The following CDDL describes the SUIT_Try_Each argument.
SUIT_Directive_Try_Each_Argument = [
+ bstr .cbor SUIT_Command_Sequence,
nil / bstr .cbor SUIT_Command_Sequence
]
7.12.6. 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
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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
7.12.7. 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 7.5.
If a parameter is already set, suit-directive-set-parameters will
skip setting the parameter to its argument. This provides the core
of the override mechanism, allowing dependent manifests to change the
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.
7.12.8. 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 7.5.
The argument to suit-directive-override-parameters is defined in the
following CDDL.
SUIT_Directive_Override_Parameters_Argument = {+ SUIT_Parameters}
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7.12.9. 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
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 or 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
7.12.10. 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
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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.
SUIT_Directive_Copy_Argument = nil
7.12.11. suit-directive-swap
suit-directive-swap instructs the manifest processor to move the
source to the destination and the destination to the source
simultaneously. Swap has nearly identical semantics to suit-
directive-copy except that suit-directive-swap replaces the source
with the current contents of the destination in an application-
defined way. If SUIT_Parameter_Compression_Info or
SUIT_Parameter_Encryption_Info are present, they must be handled in a
symmetric way, so that the source is decompressed into the
destination and the destination is compressed into the source. The
source is decrypted into the destination and the destination is
encrypted into the source. suit-directive-swap is OPTIONAL to
implement.
7.12.12. 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
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7.12.13. 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.
SUIT_Wait_Events //= (suit-wait-event-authorisation => int)
SUIT_Wait_Events //= (suit-wait-event-power => int)
SUIT_Wait_Events //= (suit-wait-event-network => int)
SUIT_Wait_Events //= (suit-wait-event-other-device-version
=> SUIT_Wait_Event_Argument_Other_Device_Version)
SUIT_Wait_Events //= (suit-wait-event-time => uint); Timestamp
SUIT_Wait_Events //= (suit-wait-event-time-of-day
=> uint); Time of Day (seconds since 00:00:00)
SUIT_Wait_Events //= (suit-wait-event-day-of-week
=> uint); Days since Sunday
SUIT_Wait_Event_Argument_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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7.12.14. SUIT_Directive CDDL
The following CDDL describes SUIT_Directive:
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SUIT_Directive //= (suit-directive-set-component-index, uint/bool)
SUIT_Directive //= (suit-directive-set-dependency-index, uint/bool)
SUIT_Directive //= (suit-directive-run-sequence,
bstr .cbor SUIT_Command_Sequence)
SUIT_Directive //= (suit-directive-try-each,
SUIT_Directive_Try_Each_Argument)
SUIT_Directive //= (suit-directive-process-dependency, nil)
SUIT_Directive //= (suit-directive-set-parameters,
{+ SUIT_Parameters})
SUIT_Directive //= (suit-directive-override-parameters,
{+ SUIT_Parameters})
SUIT_Directive //= (suit-directive-fetch, nil)
SUIT_Directive //= (suit-directive-copy, nil)
SUIT_Directive //= (suit-directive-run, nil)
SUIT_Directive //= (suit-directive-wait,
{ + SUIT_Wait_Events })
SUIT_Directive //= (suit-directive-run-with-arguments, bstr)
SUIT_Directive_Try_Each_Argument = [
+ bstr .cbor SUIT_Command_Sequence,
nil / bstr .cbor SUIT_Command_Sequence
]
SUIT_Wait_Events //= (suit-wait-event-authorisation => int)
SUIT_Wait_Events //= (suit-wait-event-power => int)
SUIT_Wait_Events //= (suit-wait-event-network => int)
SUIT_Wait_Events //= (suit-wait-event-other-device-version
=> SUIT_Wait_Event_Argument_Other_Device_Version)
SUIT_Wait_Events //= (suit-wait-event-time => uint); Timestamp
SUIT_Wait_Events //= (suit-wait-event-time-of-day
=> uint); Time of Day (seconds since 00:00:00)
SUIT_Wait_Events //= (suit-wait-event-day-of-week
=> uint); Days since Sunday
SUIT_Wait_Event_Argument_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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8. 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 preferred order, invokes them all,
then continues processing.
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9. Access Control Lists
To manage permissions in the manifest, there are three models that
can be used.
First, the simplest model requires that all manifests are
authenticated by a single trusted key. This mode has the advantage
that only a root manifest needs to be authenticated, since all of its
dependencies have digests included in the root manifest.
This simplest model can be extended by adding key delegation without
much increase in complexity.
A second model requires an ACL to be presented to the 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.
10. 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. This structure is described
by the following CDDL.
The algorithms listed are sufficient for verifying integrity of
Firmware Updates as of this writing, however this may change over
time.
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SUIT_Digest = [
suit-digest-algorithm-id : $suit-digest-algorithm-ids,
suit-digest-bytes : bytes,
? suit-digest-parameters : any
]
digest-algorithm-ids /= algorithm-id-sha224
digest-algorithm-ids /= algorithm-id-sha256
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
algorithm-id-sha224 = 1
algorithm-id-sha256 = 2
algorithm-id-sha384 = 3
algorithm-id-sha512 = 4
algorithm-id-sha3-224 = 5
algorithm-id-sha3-256 = 6
algorithm-id-sha3-384 = 7
algorithm-id-sha3-512 = 8
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.
{
"structure-version" : 1,
"sequence-number" : 7,
"common" :{
"components" : [
[b'0']
],
"common-sequence" : [
{
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"directive-set-var" : {
"size": 32567
},
},
{
"try-each" : [
[
{"condition-component-offset" : "<offset A>"},
{
"directive-set-var": {
"digest" : "<SHA256 A>"
}
}
],
[
{"condition-component-offset" : "<offset B>"},
{
"directive-set-var": {
"digest" : "<SHA256 B>"
}
}
],
[{ "abort" : null }]
]
}
]
}
"fetch" : [
{
"try-each" : [
[
{"condition-component-offset" : "<offset A>"},
{
"directive-set-var": {
"uri" : "<URI A>"
}
}
],
[
{"condition-component-offset" : "<offset B>"},
{
"directive-set-var": {
"uri" : "<URI B>"
}
}
],
[{ "directive-abort" : null }]
]
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},
"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.
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
]
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; 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
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
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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 = {
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 //= (SUIT_Condition_Vendor_Identifier => 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
SUIT_Condition_Vendor_Identifier = 1
RFC4122_UUID = bstr .size 16
SUIT_Condition_Version_Argument = [
suit-condition-version-comparison: SUIT_Condition_Version_Comparison_Types,
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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]
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
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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
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
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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.
13.1. Example 0:
Secure boot only.
The following JSON shows the intended behaviour of the manifest.
{
"structure-version": 1,
"sequence-number": 1,
"run-image": [
{ "directive-set-component": 0 },
{ "condition-image": null },
{ "directive-run": null }
],
"common": {
"common-sequence": [
{
"directive-set-var": {
"digest": "00112233445566778899aabbccddeeff"
"0123456789abcdeffedcba9876543210",
"size": 34768
}
}
],
"components": [
[
"Flash",
78848
]
]
}
}
Converted into the SUIT manifest, this produces:
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{
/ auth object / 1 : None
/ manifest / 3 : h'a40101020103583ca2024c818245466c6173684300340104'
h'582a8213a20b582000112233445566778899aabbccddeeff'
h'0123456789abcdeffedcba98765432100c1987d00c47860c'
h'0003f617f6' \
{
/ structure-version / 1 : 1
/ sequence-number / 2 : 1
/ common / 3 : h'a2024c818245466c6173684300340104582a8213a20b58'
h'2000112233445566778899aabbccddeeff0123456789ab'
h'cdeffedcba98765432100c1987d0' \ {
/ components / 2 : h'818245466c61736843003401' \
[
[h'466c617368', h'003401'],
],
/ common / 4 : h'8213a20b582000112233445566778899aabbccddee'
h'ff0123456789abcdeffedcba98765432100c1987d0'
\ [
/ set-vars / 19, {
/ digest / 11 :h'00112233445566778899aabbccddeeff01'
h'23456789abcdeffedcba9876543210',
/ size / 12 : 34768
},
],
},
/ run-image / 12 : h'860c0003f617f6' \ [
/ set-component-index / 12, 0,
/ condition-image / 3, None,
/ run / 23, None,
],
}
}
Total size of outer wrapper without COSE authentication object: 83
Outer:
a201f603584da40101020103583ca2024c818245466c6173684300340104582a8213a20b
582000112233445566778899aabbccddeeff0123456789abcdeffedcba98765432100c19
87d00c47860c0003f617f6
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,
"apply-image": [
{ "directive-set-component": 0 },
{
"directive-set-var": {
"uri": "http://example.com/file.bin"
}
},
{ "directive-fetch": null }
],
"common": {
"common-sequence": [
{
"directive-set-var": {
"digest": "00112233445566778899aabbccddeeff"
"0123456789abcdeffedcba9876543210",
"size": 34768
}
}
],
"components": [
[
"Flash",
78848
]
]
}
}
Converted into the SUIT manifest, this produces:
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{
/ auth object / 1 : None
/ manifest / 3 : h'a40101020203583ca2024c818245466c6173684300340104'
h'582a8213a20b582000112233445566778899aabbccddeeff'
h'0123456789abcdeffedcba98765432100c1987d009582586'
h'0c0013a106781b687474703a2f2f6578616d706c652e636f'
h'6d2f66696c652e62696e15f6' \
{
/ structure-version / 1 : 1
/ sequence-number / 2 : 2
/ common / 3 : h'a2024c818245466c6173684300340104582a8213a20b58'
h'2000112233445566778899aabbccddeeff0123456789ab'
h'cdeffedcba98765432100c1987d0' \ {
/ components / 2 : h'818245466c61736843003401' \
[
[h'466c617368', h'003401'],
],
/ common / 4 : h'8213a20b582000112233445566778899aabbccddee'
h'ff0123456789abcdeffedcba98765432100c1987d0'
\ [
/ set-vars / 19, {
/ digest / 11 :h'00112233445566778899aabbccddeeff01'
h'23456789abcdeffedcba9876543210',
/ size / 12 : 34768
},
],
},
/ apply-image / 9 : h'860c0013a106781b687474703a2f2f6578616d70'
h'6c652e636f6d2f66696c652e62696e15f6' \ [
/ set-component-index / 12, 0,
/ set-vars / 19, {
/ uri / 6 : http://example.com/file.bin
},
/ fetch / 21, None,
],
}
}
Total size of outer wrapper without COSE authentication object: 114
Outer:
a201f603586ca40101020203583ca2024c818245466c6173684300340104582a8213a20b
582000112233445566778899aabbccddeeff0123456789abcdeffedcba98765432100c19
87d0095825860c0013a106781b687474703a2f2f6578616d706c652e636f6d2f66696c65
2e62696e15f6
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13.3. Example 2:
Compatibility test, simultaneous download and installation, and
secure boot.
The following JSON shows the intended behaviour of the manifest.
{
"structure-version": 1,
"sequence-number": 3,
"common": {
"common-sequence": [
{
"directive-set-var": {
"vendor-id": "fa6b4a53-d5ad-5fdf-be9d-e663e4d41ffe",
"class-id": "1492af14-2569-5e48-bf42-9b2d51f2ab45",
"digest": "00112233445566778899aabbccddeeff"
"0123456789abcdeffedcba9876543210",
"size": 34768
}
},
{ "condition-vendor-id": null },
{ "condition-class-id": null }
],
"components": [
[
"Flash",
78848
]
]
},
"apply-image": [
{ "directive-set-component": 0 },
{
"directive-set-var": {
"uri": "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 / 3 : h'a501010203035864a2024c818245466c6173684300340104'
h'58528613a40350fa6b4a53d5ad5fdfbe9de663e4d41ffe04'
h'501492af1425695e48bf429b2d51f2ab450b582000112233'
h'445566778899aabbccddeeff0123456789abcdeffedcba98'
h'765432100c1987d001f602f6095825860c0013a106781b68'
h'7474703a2f2f6578616d706c652e636f6d2f66696c652e62'
h'696e15f60c47860c0003f617f6' \
{
/ structure-version / 1 : 1
/ sequence-number / 2 : 3
/ common / 3 : h'a2024c818245466c617368430034010458528613a40350'
h'fa6b4a53d5ad5fdfbe9de663e4d41ffe04501492af1425'
h'695e48bf429b2d51f2ab450b5820001122334455667788'
h'99aabbccddeeff0123456789abcdeffedcba9876543210'
h'0c1987d001f602f6' \ {
/ components / 2 : h'818245466c61736843003401' \
[
[h'466c617368', h'003401'],
],
/ common / 4 : h'8613a40350fa6b4a53d5ad5fdfbe9de663e4d41ffe'
h'04501492af1425695e48bf429b2d51f2ab450b5820'
h'00112233445566778899aabbccddeeff0123456789'
h'abcdeffedcba98765432100c1987d001f602f6' \ [
/ set-vars / 19, {
/ vendor-id / 3 : h'fa6b4a53d5ad5fdfbe9de663e4d41f'
h'fe'
/ class-id / 4 : h'1492af1425695e48bf429b2d51f2ab45'
/ digest / 11 :h'00112233445566778899aabbccddeeff01'
h'23456789abcdeffedcba9876543210',
/ size / 12 : 34768
},
/ condition-vendor-id / 1, None,
/ condition-class-id / 2, None,
],
},
/ apply-image / 9 : h'860c0013a106781b687474703a2f2f6578616d70'
h'6c652e636f6d2f66696c652e62696e15f6' \ [
/ set-component-index / 12, 0,
/ set-vars / 19, {
/ uri / 6 : http://example.com/file.bin
},
/ fetch / 21, None,
],
/ run-image / 12 : h'860c0003f617f6' \ [
/ set-component-index / 12, 0,
/ condition-image / 3, None,
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/ run / 23, None,
],
}
}
Total size of outer wrapper without COSE authentication object: 163
Outer:
a201f603589da501010203035864a2024c818245466c617368430034010458528613a403
50fa6b4a53d5ad5fdfbe9de663e4d41ffe04501492af1425695e48bf429b2d51f2ab450b
582000112233445566778899aabbccddeeff0123456789abcdeffedcba98765432100c19
87d001f602f6095825860c0013a106781b687474703a2f2f6578616d706c652e636f6d2f
66696c652e62696e15f60c47860c0003f617f6
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.
{
"structure-version": 1,
"sequence-number": 4,
"common": {
"common-sequence": [
{
"directive-set-var": {
"vendor-id": "fa6b4a53-d5ad-5fdf-be9d-e663e4d41ffe",
"class-id": "1492af14-2569-5e48-bf42-9b2d51f2ab45"
}
},
{ "directive-set-component": 0 },
{
"directive-set-var": {
"digest": "00112233445566778899aabbccddeeff"
"0123456789abcdeffedcba9876543210",
"size": 34768
}
},
{ "directive-set-component": 1 },
{
"directive-set-var": {
"digest": "00112233445566778899aabbccddeeff"
"0123456789abcdeffedcba9876543210",
"size": 34768
}
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},
{ "condition-vendor-id": null },
{ "condition-class-id": null }
],
"components": [
[
"Flash",
78848
],
[
"RAM",
1024
]
]
},
"apply-image": [
{ "directive-set-component": 0 },
{
"directive-set-var": {
"uri": "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 / 3 : h'a50101020403589ba20254828245466c6173684300340182'
h'4352414d4200040458818e13a20350fa6b4a53d5ad5fdfbe'
h'9de663e4d41ffe04501492af1425695e48bf429b2d51f2ab'
h'450c0013a20b582000112233445566778899aabbccddeeff'
h'0123456789abcdeffedcba98765432100c1987d00c0113a2'
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h'0b582000112233445566778899aabbccddeeff0123456789'
h'abcdeffedcba98765432100c1987d001f602f6095825860c'
h'0013a106781b687474703a2f2f6578616d706c652e636f6d'
h'2f66696c652e62696e15f60c518e0c0003f60c0113a10a00'
h'15f603f617f6' \
{
/ structure-version / 1 : 1
/ sequence-number / 2 : 4
/ common / 3 : h'a20254828245466c61736843003401824352414d420004'
h'0458818e13a20350fa6b4a53d5ad5fdfbe9de663e4d41f'
h'fe04501492af1425695e48bf429b2d51f2ab450c0013a2'
h'0b582000112233445566778899aabbccddeeff01234567'
h'89abcdeffedcba98765432100c1987d00c0113a20b5820'
h'00112233445566778899aabbccddeeff0123456789abcd'
h'effedcba98765432100c1987d001f602f6' \ {
/ components / 2 : h'828245466c61736843003401824352414d4200'
h'04' \
[
[h'466c617368', h'003401'],
[h'52414d', h'0004'],
],
/ common / 4 : h'8e13a20350fa6b4a53d5ad5fdfbe9de663e4d41ffe'
h'04501492af1425695e48bf429b2d51f2ab450c0013'
h'a20b582000112233445566778899aabbccddeeff01'
h'23456789abcdeffedcba98765432100c1987d00c01'
h'13a20b582000112233445566778899aabbccddeeff'
h'0123456789abcdeffedcba98765432100c1987d001'
h'f602f6' \ [
/ set-vars / 19, {
/ vendor-id / 3 : h'fa6b4a53d5ad5fdfbe9de663e4d41f'
h'fe'
/ class-id / 4 : h'1492af1425695e48bf429b2d51f2ab45'
},
/ set-component-index / 12, 0,
/ set-vars / 19, {
/ digest / 11 :h'00112233445566778899aabbccddeeff01'
h'23456789abcdeffedcba9876543210',
/ size / 12 : 34768
},
/ set-component-index / 12, 1,
/ set-vars / 19, {
/ digest / 11 :h'00112233445566778899aabbccddeeff01'
h'23456789abcdeffedcba9876543210',
/ size / 12 : 34768
},
/ condition-vendor-id / 1, None,
/ condition-class-id / 2, None,
],
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},
/ apply-image / 9 : h'860c0013a106781b687474703a2f2f6578616d70'
h'6c652e636f6d2f66696c652e62696e15f6' \ [
/ set-component-index / 12, 0,
/ set-vars / 19, {
/ uri / 6 : http://example.com/file.bin
},
/ fetch / 21, None,
],
/ run-image / 12 : h'8e0c0003f60c0113a10a0015f603f617f6' \ [
/ set-component-index / 12, 0,
/ condition-image / 3, None,
/ set-component-index / 12, 1,
/ set-vars / 19, {
/ source-component / 10 : 0
},
/ fetch / 21, None,
/ condition-image / 3, None,
/ run / 23, None,
],
}
}
Total size of outer wrapper without COSE authentication object: 228
Outer:
a201f60358dea50101020403589ba20254828245466c61736843003401824352414d4200
040458818e13a20350fa6b4a53d5ad5fdfbe9de663e4d41ffe04501492af1425695e48bf
429b2d51f2ab450c0013a20b582000112233445566778899aabbccddeeff0123456789ab
cdeffedcba98765432100c1987d00c0113a20b582000112233445566778899aabbccddee
ff0123456789abcdeffedcba98765432100c1987d001f602f6095825860c0013a106781b
687474703a2f2f6578616d706c652e636f6d2f66696c652e62696e15f60c518e0c0003f6
0c0113a10a0015f603f617f6
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.
{
"structure-version": 1,
"sequence-number": 5,
"common": {
"common-sequence": [
{
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"directive-set-var": {
"vendor-id": "fa6b4a53-d5ad-5fdf-be9d-e663e4d41ffe",
"class-id": "1492af14-2569-5e48-bf42-9b2d51f2ab45"
}
},
{ "directive-set-component": 0 },
{
"directive-set-var": {
"digest": "00112233445566778899aabbccddeeff"
"0123456789abcdeffedcba9876543210",
"size": 34768
}
},
{ "directive-set-component": 1 },
{
"directive-set-var": {
"digest": "0123456789abcdeffedcba9876543210"
"00112233445566778899aabbccddeeff",
"size": 34768
}
},
{ "condition-vendor-id": null },
{ "condition-class-id": null }
],
"components": [
[
"Flash",
78848
],
[
"RAM",
1024
]
]
},
"apply-image": [
{ "directive-set-component": 0 },
{
"directive-set-var": {
"uri": "http://example.com/file.bin"
}
},
{ "directive-fetch": null }
],
"load-image": [
{ "directive-set-component": 0 },
{ "condition-image": null },
{ "directive-set-component": 1 },
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{
"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:
{
/ auth object / 1 : None
/ manifest / 3 : h'a60101020503589ba20254828245466c6173684300340182'
h'4352414d4200040458818e13a20350fa6b4a53d5ad5fdfbe'
h'9de663e4d41ffe04501492af1425695e48bf429b2d51f2ab'
h'450c0013a20b582000112233445566778899aabbccddeeff'
h'0123456789abcdeffedcba98765432100c1987d00c0113a2'
h'0b58200123456789abcdeffedcba98765432100011223344'
h'5566778899aabbccddeeff0c1987d001f602f6095825860c'
h'0013a106781b687474703a2f2f6578616d706c652e636f6d'
h'2f66696c652e62696e15f60b508a0c0003f60c0113a20841'
h'f60a0016f60c458403f617f6' \
{
/ structure-version / 1 : 1
/ sequence-number / 2 : 5
/ common / 3 : h'a20254828245466c61736843003401824352414d420004'
h'0458818e13a20350fa6b4a53d5ad5fdfbe9de663e4d41f'
h'fe04501492af1425695e48bf429b2d51f2ab450c0013a2'
h'0b582000112233445566778899aabbccddeeff01234567'
h'89abcdeffedcba98765432100c1987d00c0113a20b5820'
h'0123456789abcdeffedcba987654321000112233445566'
h'778899aabbccddeeff0c1987d001f602f6' \ {
/ components / 2 : h'828245466c61736843003401824352414d4200'
h'04' \
[
[h'466c617368', h'003401'],
[h'52414d', h'0004'],
],
/ common / 4 : h'8e13a20350fa6b4a53d5ad5fdfbe9de663e4d41ffe'
h'04501492af1425695e48bf429b2d51f2ab450c0013'
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h'a20b582000112233445566778899aabbccddeeff01'
h'23456789abcdeffedcba98765432100c1987d00c01'
h'13a20b58200123456789abcdeffedcba9876543210'
h'00112233445566778899aabbccddeeff0c1987d001'
h'f602f6' \ [
/ set-vars / 19, {
/ vendor-id / 3 : h'fa6b4a53d5ad5fdfbe9de663e4d41f'
h'fe'
/ class-id / 4 : h'1492af1425695e48bf429b2d51f2ab45'
},
/ set-component-index / 12, 0,
/ set-vars / 19, {
/ digest / 11 :h'00112233445566778899aabbccddeeff01'
h'23456789abcdeffedcba9876543210',
/ size / 12 : 34768
},
/ set-component-index / 12, 1,
/ set-vars / 19, {
/ digest / 11 :h'0123456789abcdeffedcba987654321000'
h'112233445566778899aabbccddeeff',
/ size / 12 : 34768
},
/ condition-vendor-id / 1, None,
/ condition-class-id / 2, None,
],
},
/ apply-image / 9 : h'860c0013a106781b687474703a2f2f6578616d70'
h'6c652e636f6d2f66696c652e62696e15f6' \ [
/ set-component-index / 12, 0,
/ set-vars / 19, {
/ uri / 6 : http://example.com/file.bin
},
/ fetch / 21, None,
],
/ load-image / 11 : h'8a0c0003f60c0113a20841f60a0016f6' \ [
/ set-component-index / 12, 0,
/ condition-image / 3, None,
/ set-component-index / 12, 1,
/ set-vars / 19, {
/ unknown / 8 : h'f6'
/ source-component / 10 : 0
},
/ copy / 22, None,
],
/ run-image / 12 : h'8403f617f6' \ [
/ condition-image / 3, None,
/ run / 23, None,
],
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}
}
Total size of outer wrapper without COSE authentication object: 234
Outer:
a201f60358e4a60101020503589ba20254828245466c61736843003401824352414d4200
040458818e13a20350fa6b4a53d5ad5fdfbe9de663e4d41ffe04501492af1425695e48bf
429b2d51f2ab450c0013a20b582000112233445566778899aabbccddeeff0123456789ab
cdeffedcba98765432100c1987d00c0113a20b58200123456789abcdeffedcba98765432
1000112233445566778899aabbccddeeff0c1987d001f602f6095825860c0013a106781b
687474703a2f2f6578616d706c652e636f6d2f66696c652e62696e15f60b508a0c0003f6
0c0113a20841f60a0016f60c458403f617f6
13.6. Example 5:
Compatibility test, download, installation, and secure boot.
The following JSON shows the intended behaviour of the manifest.
{
"structure-version": 1,
"sequence-number": 6,
"common": {
"common-sequence": [
{
"directive-set-var": {
"vendor-id": "fa6b4a53-d5ad-5fdf-be9d-e663e4d41ffe",
"class-id": "1492af14-2569-5e48-bf42-9b2d51f2ab45"
}
},
{ "directive-set-component": 0 },
{
"directive-set-var": {
"digest": "00112233445566778899aabbccddeeff"
"0123456789abcdeffedcba9876543210",
"size": 34768
}
},
{ "directive-set-component": 1 },
{
"directive-set-var": {
"digest": "0123456789abcdeffedcba9876543210"
"00112233445566778899aabbccddeeff",
"size": 34768
}
},
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{ "condition-vendor-id": null },
{ "condition-class-id": null }
],
"components": [
[
"ext-Flash",
78848
],
[
"Flash",
1024
]
]
},
"apply-image": [
{ "directive-set-component": 0 },
{
"directive-set-var": {
"uri": "http://example.com/file.bin"
}
},
{ "directive-fetch": null }
],
"load-image": [
{ "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 }
]
}
Converted into the SUIT manifest, this produces:
{
/ auth object / 1 : None
/ manifest / 3 : h'a60101020603589ea202578282467b1b4595ab2143003401'
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h'8245466c6173684200040458818e13a20350fa6b4a53d5ad'
h'5fdfbe9de663e4d41ffe04501492af1425695e48bf429b2d'
h'51f2ab450c0013a20b582000112233445566778899aabbcc'
h'ddeeff0123456789abcdeffedcba98765432100c1987d00c'
h'0113a20b58200123456789abcdeffedcba98765432100011'
h'2233445566778899aabbccddeeff0c1987d001f602f60958'
h'25860c0013a106581b687474703a2f2f6578616d706c652e'
h'636f6d2f66696c652e62696e15f60b528e0c011819f60c00'
h'03f60c0113a10a0015f60c47860c0103f617f6' \
{
/ structure-version / 1 : 1
/ sequence-number / 2 : 6
/ common / 3 : h'a202578282467b1b4595ab21430034018245466c617368'
h'4200040458818e13a20350fa6b4a53d5ad5fdfbe9de663'
h'e4d41ffe04501492af1425695e48bf429b2d51f2ab450c'
h'0013a20b582000112233445566778899aabbccddeeff01'
h'23456789abcdeffedcba98765432100c1987d00c0113a2'
h'0b58200123456789abcdeffedcba987654321000112233'
h'445566778899aabbccddeeff0c1987d001f602f6' \ {
/ components / 2 : h'8282467b1b4595ab21430034018245466c6173'
h'68420004' \
[
[h'7b1b4595ab21', h'003401'],
[h'466c617368', h'0004'],
],
/ common / 4 : h'8e13a20350fa6b4a53d5ad5fdfbe9de663e4d41ffe'
h'04501492af1425695e48bf429b2d51f2ab450c0013'
h'a20b582000112233445566778899aabbccddeeff01'
h'23456789abcdeffedcba98765432100c1987d00c01'
h'13a20b58200123456789abcdeffedcba9876543210'
h'00112233445566778899aabbccddeeff0c1987d001'
h'f602f6' \ [
/ set-vars / 19, {
/ vendor-id / 3 : h'fa6b4a53d5ad5fdfbe9de663e4d41f'
h'fe'
/ class-id / 4 : h'1492af1425695e48bf429b2d51f2ab45'
},
/ set-component-index / 12, 0,
/ set-vars / 19, {
/ digest / 11 :h'00112233445566778899aabbccddeeff01'
h'23456789abcdeffedcba9876543210',
/ size / 12 : 34768
},
/ set-component-index / 12, 1,
/ set-vars / 19, {
/ digest / 11 :h'0123456789abcdeffedcba987654321000'
h'112233445566778899aabbccddeeff',
/ size / 12 : 34768
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},
/ condition-vendor-id / 1, None,
/ condition-class-id / 2, None,
],
},
/ apply-image / 9 : h'860c0013a106581b687474703a2f2f6578616d70'
h'6c652e636f6d2f66696c652e62696e15f6' \ [
/ set-component-index / 12, 0,
/ set-vars / 19, {
/ uri / 6 : h'687474703a2f2f6578616d706c652e636f6d2f66'
h'696c652e62696e'
},
/ fetch / 21, None,
],
/ load-image / 11 : h'8e0c011819f60c0003f60c0113a10a0015f6' \ [
/ set-component-index / 12, 1,
/ condition-not-image / 25, None,
/ set-component-index / 12, 0,
/ condition-image / 3, None,
/ set-component-index / 12, 1,
/ set-vars / 19, {
/ source-component / 10 : 0
},
/ fetch / 21, None,
],
/ run-image / 12 : h'860c0103f617f6' \ [
/ set-component-index / 12, 1,
/ condition-image / 3, None,
/ run / 23, None,
],
}
}
Total size of outer wrapper without COSE authentication object: 241
Outer:
a201f60358eba60101020603589ea202578282467b1b4595ab21430034018245466c6173
684200040458818e13a20350fa6b4a53d5ad5fdfbe9de663e4d41ffe04501492af142569
5e48bf429b2d51f2ab450c0013a20b582000112233445566778899aabbccddeeff012345
6789abcdeffedcba98765432100c1987d00c0113a20b58200123456789abcdeffedcba98
7654321000112233445566778899aabbccddeeff0c1987d001f602f6095825860c0013a1
06581b687474703a2f2f6578616d706c652e636f6d2f66696c652e62696e15f60b528e0c
011819f60c0003f60c0113a10a0015f60c47860c0103f617f6
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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.
{
"structure-version": 1,
"sequence-number": 7,
"common": {
"common-sequence": [
{
"directive-set-var": {
"vendor-id": "fa6b4a53-d5ad-5fdf-be9d-e663e4d41ffe",
"class-id": "1492af14-2569-5e48-bf42-9b2d51f2ab45"
}
},
{ "directive-set-component": 0 },
{
"directive-set-var": {
"digest": "00112233445566778899aabbccddeeff"
"0123456789abcdeffedcba9876543210",
"size": 34768
}
},
{ "directive-set-component": 1 },
{
"directive-set-var": {
"digest": "0123456789abcdeffedcba9876543210"
"00112233445566778899aabbccddeeff",
"size": 76834
}
},
{ "condition-vendor-id": null },
{ "condition-class-id": null }
],
"components": [
[
"Flash",
78848
],
[
"Flash",
132096
]
]
},
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"apply-image": [
{ "directive-set-component": 0 },
{
"directive-set-var": {
"uri": "http://example.com/file1.bin"
}
},
{ "directive-set-component": 1 },
{
"directive-set-var": {
"uri": "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 / 3 : h'a5010102070358a0a20257828245466c6173684300340182'
h'45466c617368430004020458838e13a20350fa6b4a53d5ad'
h'5fdfbe9de663e4d41ffe04501492af1425695e48bf429b2d'
h'51f2ab450c0013a20b582000112233445566778899aabbcc'
h'ddeeff0123456789abcdeffedcba98765432100c1987d00c'
h'0113a20b58200123456789abcdeffedcba98765432100011'
h'2233445566778899aabbccddeeff0c1a00012c2201f602f6'
h'09584b8c0c0013a106781c687474703a2f2f6578616d706c'
h'652e636f6d2f66696c65312e62696e0c0113a106781c6874'
h'74703a2f2f6578616d706c652e636f6d2f66696c65322e62'
h'696e0cf515f60c49880cf503f60c0017f6' \
{
/ structure-version / 1 : 1
/ sequence-number / 2 : 7
/ common / 3 : h'a20257828245466c617368430034018245466c61736843'
h'0004020458838e13a20350fa6b4a53d5ad5fdfbe9de663'
h'e4d41ffe04501492af1425695e48bf429b2d51f2ab450c'
h'0013a20b582000112233445566778899aabbccddeeff01'
h'23456789abcdeffedcba98765432100c1987d00c0113a2'
h'0b58200123456789abcdeffedcba987654321000112233'
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h'445566778899aabbccddeeff0c1a00012c2201f602f6'
\ {
/ components / 2 : h'828245466c617368430034018245466c617368'
h'43000402' \
[
[h'466c617368', h'003401'],
[h'466c617368', h'000402'],
],
/ common / 4 : h'8e13a20350fa6b4a53d5ad5fdfbe9de663e4d41ffe'
h'04501492af1425695e48bf429b2d51f2ab450c0013'
h'a20b582000112233445566778899aabbccddeeff01'
h'23456789abcdeffedcba98765432100c1987d00c01'
h'13a20b58200123456789abcdeffedcba9876543210'
h'00112233445566778899aabbccddeeff0c1a00012c'
h'2201f602f6' \ [
/ set-vars / 19, {
/ vendor-id / 3 : h'fa6b4a53d5ad5fdfbe9de663e4d41f'
h'fe'
/ class-id / 4 : h'1492af1425695e48bf429b2d51f2ab45'
},
/ set-component-index / 12, 0,
/ set-vars / 19, {
/ digest / 11 :h'00112233445566778899aabbccddeeff01'
h'23456789abcdeffedcba9876543210',
/ size / 12 : 34768
},
/ set-component-index / 12, 1,
/ set-vars / 19, {
/ digest / 11 :h'0123456789abcdeffedcba987654321000'
h'112233445566778899aabbccddeeff',
/ size / 12 : 76834
},
/ condition-vendor-id / 1, None,
/ condition-class-id / 2, None,
],
},
/ apply-image / 9 : h'8c0c0013a106781c687474703a2f2f6578616d70'
h'6c652e636f6d2f66696c65312e62696e0c0113a1'
h'06781c687474703a2f2f6578616d706c652e636f'
h'6d2f66696c65322e62696e0cf515f6' \ [
/ set-component-index / 12, 0,
/ set-vars / 19, {
/ uri / 6 : http://example.com/file1.bin
},
/ set-component-index / 12, 1,
/ set-vars / 19, {
/ uri / 6 : http://example.com/file2.bin
},
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/ set-component-index / 12, True,
/ fetch / 21, None,
],
/ run-image / 12 : h'880cf503f60c0017f6' \ [
/ set-component-index / 12, True,
/ condition-image / 3, None,
/ set-component-index / 12, 0,
/ run / 23, None,
],
}
}
Total size of outer wrapper without COSE authentication object: 264
Outer:
a201f603590101a5010102070358a0a20257828245466c617368430034018245466c6173
68430004020458838e13a20350fa6b4a53d5ad5fdfbe9de663e4d41ffe04501492af1425
695e48bf429b2d51f2ab450c0013a20b582000112233445566778899aabbccddeeff0123
456789abcdeffedcba98765432100c1987d00c0113a20b58200123456789abcdeffedcba
987654321000112233445566778899aabbccddeeff0c1a00012c2201f602f609584b8c0c
0013a106781c687474703a2f2f6578616d706c652e636f6d2f66696c65312e62696e0c01
13a106781c687474703a2f2f6578616d706c652e636f6d2f66696c65322e62696e0cf515
f60c49880cf503f60c0017f6
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>.
[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
[3] https://www.ietf.org/mail-archive/web/suit/current/index.html
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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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