Software Update for the Internet of Things (SUIT) Manifest Extensions for Multiple Trust Domain
draft-ietf-suit-trust-domains-11
| Document | Type | Active Internet-Draft (suit WG) | |
|---|---|---|---|
| Authors | Brendan Moran , Ken Takayama | ||
| Last updated | 2025-07-07 | ||
| Replaces | draft-moran-suit-trust-domains | ||
| RFC stream | Internet Engineering Task Force (IETF) | ||
| Intended RFC status | Proposed Standard | ||
| Formats | |||
| Reviews |
IOTDIR Telechat review
(of
-10)
by Thomas Fossati
Ready w/nits
IOTDIR Early review
(of
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by Thomas Fossati
On the right track
|
||
| Additional resources |
GitHub Repository
Mailing List Archive Related Implementations Mailing list discussion |
||
| Stream | WG state | Submitted to IESG for Publication | |
| Associated WG milestones |
|
||
| Document shepherd | Dave Thaler | ||
| Shepherd write-up | Show Last changed 2024-10-25 | ||
| IESG | IESG state | IESG Evaluation::AD Followup | |
| Action Holder | |||
| Consensus boilerplate | Yes | ||
| Telechat date |
(None)
Has enough positions to pass. |
||
| Responsible AD | Deb Cooley | ||
| Send notices to | dthaler1968@gmail.com | ||
| IANA | IANA review state | Version Changed - Review Needed |
draft-ietf-suit-trust-domains-11
SUIT B. Moran
Internet-Draft Arm Limited
Intended status: Standards Track K. Takayama
Expires: 8 January 2026 SECOM CO., LTD.
7 July 2025
Software Update for the Internet of Things (SUIT) Manifest Extensions
for Multiple Trust Domain
draft-ietf-suit-trust-domains-11
Abstract
A device has more than one trust domain when it enables delegation of
different rights to mutually distrusting entities for use for
different purposes or Components in the context of firmware or
software update. This specification describes extensions to the
Software Update for the Internet of Things (SUIT) Manifest format for
use in deployments with multiple trust domains.
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet-
Drafts is at https://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
This Internet-Draft will expire on 8 January 2026.
Copyright Notice
Copyright (c) 2025 IETF Trust and the persons identified as the
document authors. All rights reserved.
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This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents (https://trustee.ietf.org/
license-info) in effect on the date of publication of this document.
Please review these documents carefully, as they describe your rights
and restrictions with respect to this document. Code Components
extracted from this document must include Revised BSD License text as
described in Section 4.e of the Trust Legal Provisions and are
provided without warranty as described in the Revised BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Conventions and Terminology . . . . . . . . . . . . . . . . . 5
3. Changes to SUIT Workflow Model . . . . . . . . . . . . . . . 6
4. Changes to Manifest Metadata Structure . . . . . . . . . . . 6
5. Dependencies . . . . . . . . . . . . . . . . . . . . . . . . 8
5.1. Changes to Required Checks . . . . . . . . . . . . . . 8
5.2. Changes to Manifest Structure . . . . . . . . . . . . . . 9
5.2.1. Manifest Component ID . . . . . . . . . . . . . . . . 10
5.2.2. SUIT_Dependencies Manifest Element . . . . . . . . . 10
5.3. Changes to Abstract Machine Description . . . . . . . . . 12
5.4. Processing Dependencies . . . . . . . . . . . . . . . . . 13
5.4.1. Multiple Manifest Processors . . . . . . . . . . . . 13
5.5. Dependency Resolution . . . . . . . . . . . . . . . . . . 14
5.6. Added and Modified Commands . . . . . . . . . . . . . . . 14
5.6.1. suit-directive-set-parameters . . . . . . . . . . . . 15
5.6.2. suit-directive-process-dependency . . . . . . . . . . 16
5.6.3. suit-condition-is-dependency . . . . . . . . . . . . 17
5.6.4. suit-condition-dependency-integrity . . . . . . . . . 17
5.6.5. suit-directive-unlink . . . . . . . . . . . . . . . . 17
6. Uninstall . . . . . . . . . . . . . . . . . . . . . . . . . . 18
7. Staging and Installation . . . . . . . . . . . . . . . . . . 19
7.1. suit-candidate-verification . . . . . . . . . . . . . . . 19
8. Creating Manifests . . . . . . . . . . . . . . . . . . . . . 20
8.1. Dependency Template . . . . . . . . . . . . . . . . . . . 20
8.1.1. Integrated Dependencies . . . . . . . . . . . . . . . 21
8.2. Encrypted Manifest Template . . . . . . . . . . . . . . . 21
8.3. Overriding Encryption Info Template . . . . . . . . . . . 22
8.4. Operating on Multiple Components . . . . . . . . . . . . 24
9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 25
9.1. SUIT Envelope Elements . . . . . . . . . . . . . . . . . 26
9.2. SUIT Manifest Elements . . . . . . . . . . . . . . . . . 26
9.3. SUIT Common Elements . . . . . . . . . . . . . . . . . . 26
9.4. SUIT Commands . . . . . . . . . . . . . . . . . . . . . . 26
10. Security Considerations . . . . . . . . . . . . . . . . . . . 27
11. References . . . . . . . . . . . . . . . . . . . . . . . . . 28
11.1. Normative References . . . . . . . . . . . . . . . . . . 28
11.2. Informative References . . . . . . . . . . . . . . . . . 29
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Appendix A. A. Full CDDL . . . . . . . . . . . . . . . . . . . 30
Appendix B. B. Examples . . . . . . . . . . . . . . . . . . . . 31
B.1. Example 0: Process Dependency . . . . . . . . . . . . . . 32
B.2. Example 1: Integrated Dependency . . . . . . . . . . . . 36
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 38
1. Introduction
Devices that require more advanced configurations than a Manifest
signed by a single authority also require more complex rules for
deploying software updates. For example, devices may require:
* Components from multiple software signing authorities
* a mechanism to remove an unneeded Component
* Dependencies delivered in the same envelope as the Manifest
* a partly encrypted Manifest so that distribution does not reveal
private information
* installation performed by a different execution mode than payload
fetch
Devices implementing this specification typically partition their
software, dividing it, according to physical or logical features,
into multiple "domains" with different requirements for authorities:
multiple trust domains. Because of the more complex use cases that
are typically targetted by devices implementing this specification,
the applicable device class is typically Class 2+ and often isolation
level Is8, for example Arm TrustZone for Cortex-M, as described in
[I-D.ietf-iotops-7228bis].
Dependency Manifests enable several additional use cases. In
particular, they enable two or more entities who are trusted for
different privileges to coordinate. This can be used in many
scenarios. For example:
* Devices with network interface controllers (NICs), including
radios, may contain secondary processors in the NICs in addition
to the device primary processor. These two processors may have
separate Software with separate signing authorities. Dependencies
allow the Manifest for the primary processor to reference a
Manifest signed by a different authority.
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* A network operator may wish to provide local caching of Update
Payloads. The network creates a Dependent Manifest that provides
a different URI for any Payloads they wish to cache the parameter
override mechanism described in Section 5.6.1.
* A Device Administrator provides a device with some additional
configuration. The Device Administrator wants to test their
configuration with each new Software version before releasing it.
The configuration is delivered as a binary in the same way as a
Software Image. The Device Administrator references the Software
Manifest from the Software author in their own Manifest which also
defines the configuration.
* An Author wants to entrust a Distributor to provide devices with
firmware decryption keys, but not permit the Distributor to sign
code. Dependencies allow the Distributor to deliver a device's
decryption information without also granting code signing
authority.
* A Trusted Application Manager (TAM) wants to distribute
personalisation information to a Trusted Execution Environment in
addition to a Trusted Application (TA), but does not have code
signing authority (see [RFC9397], Section 2). Dependencies enable
the TAM to construct an update containing the personalisation
information and a dependency on the TA, but leaves the TA signed
by the TA's Author.
When a system has multiple trust domains, each domain might require
independent verification of authenticity or security policies. Trust
domains might be divided by separation technology such as Arm
TrustZone, Intel SGX, or another Trusted Execution Environment (TEE)
technology. Trust domains might also be divided into separate
processors and memory spaces, with a communication interface between
them.
For example, an application processor may have an attached
communications module that contains a processor. The communications
module might require metadata signed by a specific Trust Authority
for regulatory approval. This may be a different Trust Authority
than the application processor.
Dependencies enable Components such as Software, configuration, and
other Resource data authenticated by different Trust Anchors to be
delivered to devices.
These mechanisms are not part of the core Manifest specification
([I-D.ietf-suit-manifest]), but they are needed for more advanced use
cases, such as the architecture described in [RFC9397].
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This specification extends the SUIT Manifest specification
([I-D.ietf-suit-manifest]) with:
* Integrated Components
* Dependencies
* Manifest Component Identifier
* Candidate Verification
* Parameter Override support
* Uninstall support
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.
The terminology from [I-D.ietf-suit-manifest], Section 2 and
[RFC9397], Section 2 is used in this specification. Additionally,
the following terminology is used:
* Dependency: A Manifest that is required by a second Manifest in
order for operations described by the second Manifest to complete
successfully.
* Dependent: A Manifest that depends on another Mani
* Root Manifest: A manifest that has no dependents and, combined
with all Dependency Manifests (recursively) specifies a complete
Component Set.
* Staging Procedure: A procedure that fetches dependencies and
images referenced by an Update and stores them to a Staging Area.
* Installation Procedure: A procedure that installs dependencies and
images stored in a Staging Area; copying (and optionally,
transforming them) into an active Image storage location.
* Staging Area: A Component or group of Components that are used for
transient storage of Images between fetch and installation.
Images in this area are opaque, except for use by the Installation
Procedure.
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* Reference Count: An implementation-defined mechanism to track the
number of manifests that refer to another manifest.
3. Changes to SUIT Workflow Model
The use of the features presented for use with multiple trust domains
requires some augmentation of the workflow presented in the SUIT
Manifest specification ([I-D.ietf-suit-manifest]):
One additional assumption is added to the list of assumptions for the
Update Procedure in [I-D.ietf-suit-manifest], Section 4.2:
* All Dependency Manifests must be fetched and integrity checked
before any Payload is fetched.
One additional assumption is added to the list of assumptions for the
Invocation Procedure in [I-D.ietf-suit-manifest], Section 4.2:
* All Dependencies must be validated prior to loading.
Steps 3 and 5 are added to the expected installation workflow of a
Recipient:
1. Verify the signature of the Manifest.
2. Verify the applicability of the Manifest.
3. Resolve Dependencies.
4. Fetch Payload(s).
5. Verify Candidate Component Set.
6. Install Payload(s).
7. Verify image(s).
In addition, 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. The lockstep process is described in
Section 5.4.
4. Changes to Manifest Metadata Structure
To accommodate the additional metadata needed to enable these
features, the Envelope and Manifest are augmented with several new
elements:
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* Envelope
- Integrated Dependency
* Manifest
- Common
o Dependency Metadata
- Component Identifier
- Dependency Resolution SUIT_Command_Sequence
- Candidate Verification SUIT_Command_Sequence
In addition several new SUIT_Commands are added:
* SUIT Conditions
- Dependency Integrity Check
- Component Is Dependency Check
* SUIT Directives
- Process Dependency
- Set Parameters
- Unlink
The Envelope gains two more elements: Integrated Dependencies and
Integrated Payloads. The Common metadata section in the Manifest
also gains a list of Dependencies.
The new metadata structure is shown below.
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+-------------------------+
| Envelope |
+-------------------------+
| Authentication Block |
| Manifest --------------> +------------------------------+
| Severable Elements | | Manifest |
| Integrated Dependencies | +------------------------------+
| Integrated Payloads | | Structure Version |
+-------------------------+ | Sequence Number |
| Reference to Full Manifest |
+------ Common Structure |
| +---- Command Sequences |
+-------------------------+ | | | Digests of Envelope Elements |
| Common Structure | <--+ | +------------------------------+
+-------------------------+ |
| Dependency Indices | +-> +-----------------------+
| Component IDs | | Command Sequence |
| Common Command Sequence ---------> +-----------------------+
+-------------------------+ | List of ( pairs of ( |
| * command code |
| * argument / |
| reporting policy |
| )) |
+-----------------------+
This is an update of the figure in Section 4.2 of
[I-D.ietf-suit-manifest]
5. Dependencies
A Dependency is another SUIT_Envelope ([I-D.ietf-suit-manifest],
section 8.2) that describes additional Components.
5.1. Changes to Required Checks
This section augments the definitions in Required Checks
([I-D.ietf-suit-manifest], Section 6.2).
More checks are required when handling Dependencies. By default, any
signature of a Dependency MUST be verified. However, there are some
exceptions to this rule: where a device supports only one level of
access (no ACLs, [I-D.ietf-suit-manifest], Section 9, declaring which
authorities have access to different Components/Commands/Parameters),
it MAY choose to skip signature verification of Dependencies, since
they are verified by digest. Where a device differentiates between
trust levels, such as with an ACL, it MAY choose to defer the
verification of signatures of Dependencies until the list of affected
Components is known so that it can skip redundant signature
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verifications. For example, if a dependent's signer has access
rights to all Components specified in a Dependency, then that
Dependency does not require a signature verification. Similarly, if
the signer of the dependent has full rights to the device, according
to the ACL, then no signature verification is necessary on the
Dependency.
Components that should be treated as Dependency Manifests are
identified in the suit-common metadata (Section 5.2).
Any required check that fails MUST result in an Abort.
If the Manifest contains more than one Component and/or Dependency,
each Command sequence MUST begin with a Set Component Index Command.
If a Dependency is specified, then the Manifest Processor MUST
perform the following checks:
1. The dependent MUST populate all Command sequences for the current
Procedure; either the Staging Procedure, the Update Procedure,
the Installation Procedure, or the Invocation Procedure.
2. At the end of each section in the dependent: The corresponding
section in each Dependency has been executed.
If the interpreter does not support Dependencies and a Manifest
specifies a Dependency, then the interpreter MUST Abort.
If a Recipient supports groups of interdependent Components (a
Component Set), then it SHOULD verify that all Components in the
Component Set are specified by a single Manifest and all its
Dependencies that together:
1. have sufficient permissions imparted by their signatures
2. specify a digest and a Payload for every Component in the
Component Set.
Failing to verify the availablility of all components may lead to API
mismatches and other version mismatch problems.
The single dependent Manifest is called a Root Manifest.
5.2. Changes to Manifest Structure
This section augments the Manifest Structure (Section 8.4) in
[I-D.ietf-suit-manifest].
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5.2.1. Manifest Component ID
In complex systems, it may not always be clear where the Root
Manifest is stored; this is particularly complex when a system has
multiple, independent Root Manifests. The Manifest Component ID
resolves this contention. The manifest-component-id is intended to
be used by the Root Manifest. The manifest-component-id is only used
when storing a Root Manifest. The manifest-component-id is ignored
when processing Dependency Manifests.
The following CDDL (see [RFC8610]) describes the Manifest Component
ID:
$$SUIT_Manifest_Extensions //=
(suit-manifest-component-id => SUIT_Component_Identifier)
5.2.2. SUIT_Dependencies Manifest Element
The suit-common section, as described in [I-D.ietf-suit-manifest],
Section 8.4.5 is extended with a map of Component indices that
indicate a Dependency Manifest. The keys of the map are the
Component indices and the values of the map are any extra metadata
needed to describe those Dependency Manifests.
Because some operations treat Dependency Manifests differently from
other Components, it is necessary to identify them.
SUIT_Dependencies identifies which Components from suit-components
([I-D.ietf-suit-manifest], Section 8.4.5) are to be treated as the
SUIT_Envelope of a Dependency Manifest. SUIT_Dependencies is a map
of Components, referenced by Component Index. Optionally, a
Component prefix or other metadata may be delivered with the
Component index. The CDDL for suit-dependencies is shown below:
$$SUIT_Common-extensions //= (
suit-dependencies => SUIT_Dependencies
)
SUIT_Dependencies = {
+ uint => SUIT_Dependency_Metadata
}
SUIT_Dependency_Metadata = {
? suit-dependency-prefix => SUIT_Component_Identifier
* $$SUIT_Dependency_Extensions
}
If no extended metadata is needed for an extension,
SUIT_Dependency_Metadata is an empty map (this is the same encoding
size as a null). SUIT_Dependencies MUST be sorted according to Core
Deterministic Encoding Requirements ([RFC8949], Section 4.2.1).
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The Components specified by SUIT_Dependency_Metadata will contain a
Manifest Envelope that describes a Dependency of the current
Manifest. The Manifest is identified, but the Recipient should
expect an Envelope when it acquires the Dependency. This is because
the Manifest is the one invariant element of the Envelope, where
other elements may change by countersigning, adding authentication
blocks, or severing elements.
When executing suit-condition-image-match over a Component that is
designated in SUIT_Dependency_Metadata, the digest MUST be computed
over just the bstr-wrapped SUIT_Manifest contained in the Manifest
Envelope designated by the Component Index. This enables a
Dependency reference to uniquely identify a particular Manifest
structure. This is identical to the digest that is present as the
first element of the suit-authentication-block in the Dependency's
Envelope. The digest is calculated over the Manifest structure to
ensure that removing a signature from a Manifest does not break
Dependencies due to missing signature elements. This is also
necessary to support the trusted intermediary use case, where an
intermediary re-signs the Manifest, removing the original signature,
potentially with a different algorithm, or trading COSE_Sign for
COSE_Mac.
The suit-dependency-prefix element contains a
SUIT_Component_Identifier ([I-D.ietf-suit-manifest],
Section 8.4.5.1). This specifies the scope at which the Dependency
operates. This allows the Dependency to be forwarded on to a
Component that is capable of parsing its own Manifests. It also
allows one Manifest to be deployed to multiple dependent Recipients
without those Recipients needing consistent Component hierarchy.
suit-dependency-prefix is OPTIONAL for Recipients to implement.
A Dependency prefix can be used with a Component identifier. This
allows complex systems to understand where Dependencies need to be
applied. The Dependency prefix can be used in one of two ways. The
first simply prepends the prefix to all Component Identifiers in the
Dependency.
A Dependency prefix can also be used to indicate when a Dependency
Manifest needs to be processed by a secondary Manifest Processor, as
described in Section 5.4.1.
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5.3. Changes to Abstract Machine Description
This section augments the Abstract Machine Description in
[I-D.ietf-suit-manifest], Section 6.4. With the addition of
Dependencies, some changes are necessary to the abstract machine,
outside the typical scope of added Commands. These changes alter the
behaviour of an existing Command and way that the parser processes
Manifests:
* Five new Commands are introduced in Section 5.6:
- Set Parameters
- Process Dependency
- Is Dependency
- Dependency Integrity
- Unlink
* Dependency Manifests have Component Identifiers. All Commands may
target Dependency Manifests as well as Components, with one
exception: suit-directive-process-dependency. Future commands MAY
define their own restrictions on applicability to Dependency
Manifests and non-Dependency Components.
* Dependencies are processed in lockstep with the Root Manifest.
This means that every Dependency's current Command sequence must
be executed before a dependent's later Command sequence may be
executed. For example, every Dependency's Dependency Resolution
step must be executed before any dependent's Payload fetch step.
* When a Manifest Processor supports multiple independent
Components, they may have shared Dependencies.
* When a Manifest Processor supports shared Dependencies, it MUST
support reference counting of those Dependencies.
* When reference counting is used, Components MUST NOT be
overwritten. The Manifest Uninstall section must be called, then
the component MUST be Unlinked.
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5.4. Processing Dependencies
As described in Section 5.1, the Manifest Processor must ensure that
a Manifest with Dependencies invokes suit-directive-process-
dependency for each of its Dependencies' sections from the
corresponding section of the dependent. Any changes made to
Parameters by the Dependency persist in the dependent.
When a Process Dependency Command is encountered, the Manifest
Processor:
1. Checks whether the map of Dependencies contains an entry for the
current Component Index. If not present, it causes an immediate
Abort.
2. Checks whether the Dependency has been the target of a Dependency
integrity check. If not, it causes an immediate Abort.
3. Performs any application-specific setup that is required to parse
the specified Component as a SUIT_Envelope of a Dependency
Manifest.
4. Authenticates the Dependency Manifest.
5. Executes the common-sequence section of the Dependency Manifest.
6. Executes the section of the Dependency Manifest that corresponds
to the currently executing section of the dependent.
If the specified Dependency does not contain the current section,
Process Dependency succeeds immediately.
The interpreter also performs the checks described in Section 5.1 to
ensure that the dependent is processing the Dependency correctly.
5.4.1. Multiple Manifest Processors
When there are two or more trust domains, a Manifest Processor might
be required in each. The first Manifest Processor is the normal
Manifest Processor as described for the Recipient in Section 6 of
[I-D.ietf-suit-manifest]. The second Manifest Processor only
executes sections when the first Manifest Processor requests it. An
API interface is provided from the second Manifest Processor to the
first. This allows the first Manifest Processor to request a limited
set of operations from the second. These operations are limited to:
setting Parameters, inserting an Envelope, and invoking a Manifest
Command Sequence. The second Manifest Processor declares a prefix to
the first, which tells the first Manifest Processor when it should
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delegate to the second. These rules are enforced by underlying
separation of privilege infrastructure, such as TEEs, or physical
separation.
When the first Manifest Processor encounters a Dependency prefix,
that informs the first Manifest Processor that it should provide the
second Manifest Processor with the corresponding Dependency Envelope.
This is done when the Dependency is fetched. The second Manifest
Processor immediately verifies any authentication information in the
Dependency Envelope. When a Parameter is set for any Component that
matches the prefix, this Parameter setting is passed to the second
Manifest Processor via an API. As the first Manifest Processor works
through the Procedure (set of Command sequences) it is executing,
each time it sees a Process Dependency Command that is associated
with the prefix declared by the second Manifest Processor, it uses
the API to ask the second Manifest Processor to invoke that
Dependency section instead.
This mechanism ensures that the two or more Manifest Processors do
not need to trust each other, except in a very limited case. When
Parameter setting across trust domains is used, it must be very
carefully considered. Only Parameters that do not have an effect on
security properties should be allowed. The Dependency Manifest MAY
control which Parameters are allowed to be set by using the Override
Parameters Directive. The second Manifest Processor MAY also control
which Parameters may be set by the first Manifest Processor by means
of an ACL that lists the allowed Parameters. For example, a URI may
be set by a dependent without a substantial impact on the security
properties of the Manifest.
5.5. Dependency Resolution
The Dependency Resolution Command Sequence is a container for the
Commands needed to acquire and process the Dependencies of the
current Manifest. All Dependency Manifests MUST be fetched before
any Payload is fetched to ensure that all Manifests are available and
authenticated before any of the (larger) Payloads are acquired.
5.6. Added and Modified Commands
All Commands are modified in that they can also target Dependencies.
However, Set Component Index has a larger modification.
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+================+====================================+
| Command Name | Semantic of the Operation |
+================+====================================+
| Set Parameters | current.params[k] := v if not k in |
| | current.params for-each k,v in arg |
+----------------+------------------------------------+
| Process | exec(current[common]); |
| Dependency | exec(current[current-segment]) |
+----------------+------------------------------------+
| Dependency | verify(current, |
| Integrity | current.params[image-digest]) |
+----------------+------------------------------------+
| Is Dependency | assert(current exists in |
| | Dependencies) |
+----------------+------------------------------------+
| Unlink | unlink(current) |
+----------------+------------------------------------+
Table 1
5.6.1. suit-directive-set-parameters
Similar to suit-directive-override-parameters
([I-D.ietf-suit-manifest], section 8.4.10.3), suit-directive-set-
parameters allows the Manifest to configure behavior of future
Directives by changing Parameters that are read by those Directives.
Set Parameters is for use when Dependencies are used because it
allows a Manifest to modify the behavior of its Dependencies.
Because of this modification behavior, suit-directive-set-parameters
MUST only be used for parameters that are intended to be overridden.
Available Parameters are defined in [I-D.ietf-suit-manifest], section
8.4.8.
If a Parameter is already set, suit-directive-set-parameters will
skip setting the Parameter to its argument. This enables parameter
replacement in Manifest trees. A Dependency Manifest can specify a
default Parameter using suit-directive-set-parameters. Then, a
dependent of that Dependency can use suit-directive-set-parameters
prior to invoking suit-directive-process-dependency. Since suit-
directive-set-parameters has set-if-unset behaviour, this means that
the dependent has effectively overriden the Dependency's Parameter.
Manifests that wish to enforce a specific value of a Parameter MUST
use suit-directive-override-parameters instead. This satisfies
USER_STORY.OVERRIDE and REQ.USE.MFST.COMPONENT of [RFC9124].
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While suit-directive-set-parameters can be used outside of a
Dependency use case, it has limited applicability: in linear
manifests (without try-each, [I-D.ietf-suit-manifest], section
8.4.10.2) it either behaves as suit-directive-override-parameters or
has no effect, depending on whether its targets are already set.
When used as a set-if-unset construction following a try-each, suit-
directive-override-parameters has the same effect as if a suit-
directive-override-parameters were placed in the final element of the
try-each with no preceding condition. This limits the applicability
of suit-directive-set-parameters outside dependency use cases.
suit-directive-set-parameters does not specify a reporting policy.
5.6.2. 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 "Payload Fetch,"
this will execute "Common metadata" in the current Dependency, then
"Payload Fetch" in the current Dependency. Once this is complete,
the Command following suit-directive-process-dependency will be
processed.
If the current Component Index matches any of the following
conditions, the Manifest Processor MUST Abort:
* The current Component index does not have an entry in the suit-
dependencies map
* The current Component index has not been the target of a suit-
condition-dependency-integrity
* The current section is "Common metadata"
If the current Component is True, then this Directive applies to all
Dependencies.
When suit-directive-process-dependency completes, it forwards the
last status code that occurred in the Dependency; an Abort in a
Dependency causes an Abort in the suit-directive-process-dependency
of the Dependent.
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5.6.3. suit-condition-is-dependency
Check whether the current Component index is present in the
Dependency list. If the current Component is in the Dependency list,
suit-condition-is-dependency succeeds. Otherwise, it fails. This
can be used along with component-id = True to act on all Dependencies
or on all non-Dependency Components (Section 8).
5.6.4. suit-condition-dependency-integrity
Verify the integrity of a Dependency Manifest. When a Manifest
Processor executes suit-condition-dependency-integrity, it performs
the following operations:
1. Verify the signature of the Dependency's suit-authentication-
wrapper.
2. Compare the Dependency's suit-authentication-wrapper digest to
the dependent's suit-parameter-image-digest
3. Verify the Dependency Manifest against the Depedency's suit-
authentication-wrapper digest
If any of these steps fails, the Manifest Processor MUST immediately
Abort.
The Manifest Processor MAY cache the results of these operations for
later use from the context of the current Manifest. The Manifest
Processor MUST NOT use cached results from any other Manifest
context. The Manifest Processor MUST prevent tampering with the
cached results, e.g. through tamper-evident memory. If the Manifest
Processor caches the results of these checks, it MUST eliminate this
cache if:
* Any Fetch, or Copy operation targets the Dependency Manifest's
Component ID
* An Abort is encountered
* A Procedure completes
5.6.5. suit-directive-unlink
A Manifest Processor that supports multiple independent root
manifests MUST support suit-directive-unlink. When a Component is no
longer needed, the Manifest Processor unlinks the Component to inform
the Manifest Processor that it is no longer needed.
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If a Manifest is no longer needed, the Manifest Processor unlinks it.
This causes the Manifest Processor to execute the suit-uninstall
section of the unlinked Manifest, after which it decrements the
reference count of the unlinked Manifest. The suit-uninstall section
of a manifest typically contains an unlink of all its dependencies
and components.
All components, including Manifests must be unlinked before deletion
or overwrite. If the reference count of a component is non-zero, any
command that alters that component MUST cause the Manifest Processor
to Abort. Affected commands are:
* suit-directive-copy
* suit-directive-fetch
* suit-directive-write
The unlink Command decrements an implementation-defined reference
counter. This reference counter MUST persist across restarts. The
reference counter MUST NOT be decremented by a given Manifest more
than once, and the Manifest Processor must enforce this. The
Manifest Processor MAY choose to ignore an Unlink Directive depending
on device policy.
When the reference counter of a Manifest reaches zero, the suit-
uninstall Command sequence is invoked (Section 6).
suit-directive-unlink is OPTIONAL to implement in Manifest
Processors, but Manifest Processors that support multiple independent
Root Manifests MUST support suit-directive-unlink.
6. Uninstall
In some systems, particularly with multiple, independent, optional
Components, it may be that there is a need to uninstall the
Components that have been installed by a Manifest. Where this is
expected, the uninstall Command sequence can provide the sequence
needed to cleanly remove the Components defined by the Manifest and
its Dependencies. In general, the suit-uninstall Command Sequence
will contain primarily unlink Directives.
WARNING: This can cause faults where there are loose Dependencies
(e.g., version range matching, [I-D.ietf-suit-update-management],
Section 5.5), since a Component can be removed while it is depended
upon by another Component. To avoid Dependency faults, a Manifest
author MUST use explicit Dependencies where possible. To enable
applications where explicit Dependency matching is not possible, a
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Manifest Processor can track references to loose Dependencies via
reference counting in the same way as explicit Dependencies, as
described in Section 5.6.5.
The suit-uninstall Command Sequence is not severable, since it must
always be available to enable uninstalling.
7. Staging and Installation
In order to coordinate between download and installation in different
trust domains, the Update Procedure defined in
[I-D.ietf-suit-manifest], Section 8.4.6 is divided into two sub-
procedures:
* The Staging Procedure: This procedure is responsible for
dependency resolution and acquiring all payloads required for the
Update to proceed. It is composed of two command sequences
- suit-dependency-resolution
- suit-payload-fetch
* The Installation Procedure: This procedure is responsible for
verifying staged components and installing them. It is composed
of:
- suit-candidate-verification
- suit-install
This extension is backwards compatible when used with a Manifest
Processor that supports the Update Procedure but does not support the
Staging Procedure and Installation Procedure: the payload-fetch
command sequence already contains suit-condition-image tests for each
payload ([I-D.ietf-suit-manifest], section 7.3) which means that
images are already validated when suit-install is invoked. This
makes suit-candidate-verification OPTIONAL to implement.
The Staging and Installation Procedures are only required when
Staging occurs in a different trust domain to Installation.
7.1. suit-candidate-verification
This command sequence is responsible for verifying that all elements
of an update are present and correct prior to installation. This is
only required when Installation occurs in a trust domain different
from Staging, such as an installer invoked by the bootloader.
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8. Creating Manifests
This section details a set of templates for creating Manifests.
These templates explain which Parameters, Commands, and orders of
Commands are necessary to achieve a stated goal.
8.1. Dependency Template
The goal of the Dependency template is to obtain, verify, and process
a Dependency Manifest as appropriate.
The following Commands are added to the shared sequence:
* Set Component Index Directive ([I-D.ietf-suit-manifest],
Section 8.4.10.1)
* Set Parameters Directive (Section 5.6.1) for digest
([I-D.ietf-suit-manifest], Section 8.4.8.6). Note that the digest
MUST match the SUIT_Digest in the Dependency's suit-
authentication-block ([I-D.ietf-suit-manifest], Section 8.3).
The following Commands are placed into the Dependency resolution
sequence:
* Set Component Index Directive ([I-D.ietf-suit-manifest],
Section 8.4.10.1)
* Set Parameters Directive (Section 5.6.1) for a URI
([I-D.ietf-suit-manifest], Section 8.4.8.10)
* Fetch Directive ([I-D.ietf-suit-manifest], Section 8.4.10.4)
* Dependency Integrity Condition (Section 5.6.4)
* Process Dependency Directive (Section 5.6.2)
Then, the validate sequence contains the following operations:
* Set Component Index Directive ([I-D.ietf-suit-manifest],
Section 8.4.10.1)
* Dependency Integrity Condition (Section 5.6.4)
* Process Dependency Directive (Section 5.6.2)
If any Dependency is declared, the dependent MUST populate all
Command sequences for the current Procedure (Update or Invoke).
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NOTE: Any changes made to Parameters in a Dependency persist in the
dependent.
8.1.1. Integrated Dependencies
An implementer MAY choose to place a Dependency's Envelope in the
Envelope of its dependent. The dependent Envelope key for the
Dependency Envelope MUST be a text string. The URI for the
Dependency MUST match the text string key of the dependent's Envelope
key. It is RECOMMENDED to make the text string key a resolvable URI
so that a Dependency Manifest that is removed from the Envelope can
still be fetched.
8.2. Encrypted Manifest Template
The goal of the Encrypted Manifest template is to fetch and decrypt a
Manifest so that it can be used as a Dependency. To use an encrypted
Manifest, create a plaintext dependent, and add the encrypted
Manifest as a Dependency. The dependent can include very little
information.
NOTE: This template also requires the extensions defined in
[I-D.ietf-suit-firmware-encryption].
The following Commands are added to the shared sequence:
* Set Component Index Directive ([I-D.ietf-suit-manifest],
Section 8.4.10.1)
* Set Parameters Directive (Section 5.6.1) for digest
([I-D.ietf-suit-manifest], Section 8.4.8.6). Note that the digest
MUST match the SUIT_Digest in the Dependency's suit-
authentication-block ([I-D.ietf-suit-manifest], Section 8.3).
The following operations are placed into the Dependency resolution
block:
* Set Component Index Directive ([I-D.ietf-suit-manifest],
Section 8.4.10.1)
* Set Parameters Directive (Section 5.6.1) for
- URI ([I-D.ietf-suit-manifest], Section 8.4.8.9)
- Encryption Info ([I-D.ietf-suit-firmware-encryption])
* Fetch Directive ([I-D.ietf-suit-manifest], Section 8.4.10.4)
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* Dependency Integrity Condition (Section 5.6.4)
* Process Dependency Directive (Section 5.6.2)
Then, the validate block contains the following operations:
* Set Component Index Directive ([I-D.ietf-suit-manifest],
Section 8.4.10.1)
* Check Image Match Condition ([I-D.ietf-suit-manifest],
Section 8.4.9.2)
* Process Dependency Directive (Section 5.6.2)
A plaintext Manifest and its encrypted Dependency may also form a
composite Manifest (Section 8.1.1).
8.3. Overriding Encryption Info Template
The goal of overriding the Encryption Info template is to separate
the role of generating encrypted Payload and Encryption Info with
Key-Encryption Key addressing Section 3 of
[I-D.ietf-suit-firmware-encryption].
As an example, this template describes two manifests: - The dependent
Manifest created by the Distribution System contains Encryption Info,
allowing the Device to generate the Content-Encryption Key. - The
dependency Manifest created by the Author contains Commands to
decrypt the encrypted Payload using Encryption Info above and to
validate the plaintext Payload with SUIT_Digest.
NOTE: This template also requires the extensions defined in
[I-D.ietf-suit-firmware-encryption].
The following operations are placed into the Dependency resolution
block of dependent Manifest:
* Set Component Index Directive ([I-D.ietf-suit-manifest],
Section 8.4.10.1) pointing at dependency Manifest
* Set Parameters Directive (Section 5.6.1) for
- Image Digest ([I-D.ietf-suit-manifest], Section 8.4.8.6)
- URI ([I-D.ietf-suit-manifest], Section 8.4.8.9) of dependency
Manifest
* Fetch Directive ([I-D.ietf-suit-manifest], Section 8.4.10.4)
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* Dependency Integrity Condition (Section 5.6.4)
The following Commands are placed into the Fetch/Install block of
dependent Manifest
* Set Component Index Directive ([I-D.ietf-suit-manifest],
Section 8.4.10.1) pointing at encrypted Payload
* Set Parameters Directive (Section 5.6.1) for
- URI ([I-D.ietf-suit-manifest], Section 8.4.8.9)
* Set Component Index Directive ([I-D.ietf-suit-manifest],
Section 8.4.10.1) pointing at dependency Manifest
* Set Parameters Directive (Section 5.6.1) for
- Encryption Info ([I-D.ietf-suit-firmware-encryption])
* Process Dependency Directive (Section 5.6.2)
The following Commands are placed into the same block of dependency
Manifest:
* Set Component Index Directive ([I-D.ietf-suit-manifest],
Section 8.4.10.1) pointing at encrypted Payload
* Fetch Directive ([I-D.ietf-suit-manifest], Section 8.4.10.4)
* Set Component Index Directive ([I-D.ietf-suit-manifest],
Section 8.4.10.1) pointing at to be decrypted Payload
* Override Parameters Directive ([I-D.ietf-suit-manifest],
Section 8.4.10.3) for
- Source Component ([I-D.ietf-suit-manifest], Section 8.4.8.11)
pointing at encrypted Payload
* Copy Directive ([I-D.ietf-suit-manifest], Section 8.4.10.5)
consuming the Encryption Info above
The Distribution System can Set the URI Parameter in the Fetch/
Install block of dependent Manifest if it wants to overwrite the URI
of the encrypted Payload.
Because the Author and the Distribution System have different roles
and may be separate entities, it is highly recommended to leverage
permissions ([I-D.ietf-suit-manifest], Section 9). For example, the
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Device can protect itself from an attacker who breaches the
Distribution System by allowing only the Author's Manifest to modify
the Component of (to be) decrypted Payload.
8.4. Operating on Multiple Components
In order to produce compact encoding, it is efficient to perform
operations on multiple Components simultaneously. Because Dependency
Manifests and Component Images are processed at different times,
there is a mechanism to distinguish between these elements: suit-
condition-is-dependency. This can be used with suit-directive-try-
each to perform operations just on Dependency Manifests or just on
Component Images.
For example, to fetch all Dependency Manifests, the following
Commands are added to the Dependency resolution block:
* Set Component Index Directive ([I-D.ietf-suit-manifest],
Section 8.4.10.1)
* Set Parameters Directive (Section 5.6.1) for a URI
([I-D.ietf-suit-manifest], Section 8.4.8.9)
* Set Component Index Directive, with argument "True"
([I-D.ietf-suit-manifest], Section 8.4.10.1)
* Try Each Directive
- Sequence 0
o Condition Is Dependency Manifest
o Fetch
o Dependency Integrity Condition (Section 5.6.4)
o Process Dependency
- Sequence 1 (Empty; no Commands, succeeds immediately)
Another example is to fetch and validate all Component Images. The
Image fetch sequence contains the following Commands:
* Set Component Index Directive ([I-D.ietf-suit-manifest],
Section 8.4.10.1)
* Set Parameters Directive (Section 5.6.1) for a URI
([I-D.ietf-suit-manifest], Section 8.4.8.9)
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* Set Component Index Directive, with argument "True"
([I-D.ietf-suit-manifest], Section 8.4.10.1)
* Try Each Directive
- Sequence 0
o Condition Is Dependency Manifest
o Process Dependency
- Sequence 1
o Fetch
o Condition Image Match
When some Components are "installed" or "loaded" it is more
productive to use lists of Component indices rather than Component
Index = True. For example, to install several Components, the
following Commands should be placed in the Image Install Sequence:
* Set Component Index Directive ([I-D.ietf-suit-manifest],
Section 8.4.10.1)
* Set Parameters Directive (Section 5.6.1) for the Source Component
([I-D.ietf-suit-manifest], Section 8.4.8.11)
* Set Component Index Directive, with argument containing list of
destination Component indices ([I-D.ietf-suit-manifest],
Section 8.4.10.1)
* Copy
* Set Component Index Directive, with argument containing list
Dependency Component indices ([I-D.ietf-suit-manifest],
Section 8.4.10.1)
* Process Dependency
9. IANA Considerations
IANA is requested to allocate the following numbers in the listed
registries created by draft-ietf-suit-manifest:
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9.1. SUIT Envelope Elements
+=======+========================+=============+
| Label | Name | Reference |
+=======+========================+=============+
| 15 | Dependency Resolution | Section 5.5 |
+-------+------------------------+-------------+
| 18 | Candidate Verification | Section 7.1 |
+-------+------------------------+-------------+
Table 2
9.2. SUIT Manifest Elements
+=======+========================+===============+
| Label | Name | Reference |
+=======+========================+===============+
| 5 | Manifest Component ID | Section 5.2.1 |
+-------+------------------------+---------------+
| 15 | Dependency Resolution | Section 5.5 |
+-------+------------------------+---------------+
| 18 | Candidate Verification | Section 7.1 |
+-------+------------------------+---------------+
| 24 | Uninstall | Section 6 |
+-------+------------------------+---------------+
Table 3
9.3. SUIT Common Elements
+=======+==============+===============+
| Label | Name | Reference |
+=======+==============+===============+
| 1 | Dependencies | Section 5.2.2 |
+-------+--------------+---------------+
Table 4
9.4. SUIT Commands
+=======+======================+===============+
| Label | Name | Reference |
+=======+======================+===============+
| 7 | Dependency Integrity | Section 5.6.4 |
+-------+----------------------+---------------+
| 8 | Is Dependency | Section 5.6.3 |
+-------+----------------------+---------------+
| 11 | Process Dependency | Section 5.6.2 |
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+-------+----------------------+---------------+
| 19 | Set Parameters | Section 5.6.1 |
+-------+----------------------+---------------+
| 33 | Unlink | Section 5.6.5 |
+-------+----------------------+---------------+
Table 5
10. Security Considerations
This specification is about a Manifest format protecting and
describing how to retrieve, install, and invoke Images and as such it
is part of a larger solution for delivering software updates to
devices. A detailed security treatment can be found in the SUIT
architecture [RFC9019] and in the SUIT information model [RFC9124].
The features added in this specification introduce several new
threats. The introduction of Dependencies enables multiple entities
to operate on a device with different privileges. While this is
necessary to fulfill REQ.USE.MFST.COMPONENT ([RFC9124],
Section 4.5.4), it also introduces a new requirement:
REQ.SEC.ACCESS_CONTROL ([RFC9124], Section 4.3.13), which is required
to address THREAT.MFST.OVERRIDE ([RFC9124], Section 4.2.13) and
THREAT.UPD.UNAPPROVED ([RFC9124], Section 4.2.11).
Simultaneous processing of multiple Manifests, as enabled by
Dependency processing, introduces risks of TOCTOU threats
(THREAT.MFST.TOCTOU: [RFC9124], Section 4.2.18). Holding multiple
Manifest Envelopes in memory simultaneously can exceed the capacity
of the Manifest Processor's tamper-protected memory
(REQ.SEC.MFST.CONST: [RFC9124], Section 4.3.21). To address this
threat, the Manifest Processor MAY use modular processing as
described in REQ.USE.PAYLOAD ([RFC9124], Section 4.5.12). If
retaining the Manifests only, excluding envelopes, in immutable
memory does not provide enough capacity, the Manifest Processor MAY
reduce overhead by retaining the following elements for each manifest
in immutable memory:
* Manifest Digest
* Parameters
* Current Component Index
* Current Command Sequence
* Current Command Sequence Offset
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This allows a Manifest Processor to resume processing a manifest as
follows:
* Copy the Manifest into immutable memory
* Validate the Manifest using the stored Manifest Digest
* Parse forward to find the Current Command Sequence
* Jump within the Command Seqeunce to the stored Command Sequence
Offset
When identifying a Root Manifest's correct storage location, the
Component Identifier MUST be evaluated vs. the access priviliges of
an Author. Otherwise, the Component Identifier may permit an
escalation of privilege: an authorised Author causes a manifest to be
installed in a location for which the Author does not have access
rights.
Since Dependencies are stored as Components, Dependency Integrity
Checks and Image Verification are slightly different operations.
While a typical Image is immutable, a Manifest Envelope can be
modified in some ways (e.g. removing a Severable Element) without
changing the Integrity Check result. Because of these factors, suit-
directive-process-dependency requires that a dependency first be
validated with suit-check suit-condition-dependency-integrity.
11. References
11.1. Normative References
[I-D.ietf-suit-firmware-encryption]
Tschofenig, H., Housley, R., Moran, B., Brown, D., and K.
Takayama, "Encrypted Payloads in SUIT Manifests", Work in
Progress, Internet-Draft, draft-ietf-suit-firmware-
encryption-25, 7 July 2025,
<https://datatracker.ietf.org/doc/html/draft-ietf-suit-
firmware-encryption-25>.
[I-D.ietf-suit-manifest]
Moran, B., Tschofenig, H., Birkholz, H., Zandberg, K., and
O. Rønningstad, "A Concise Binary Object Representation
(CBOR)-based Serialization Format for the Software Updates
for Internet of Things (SUIT) Manifest", Work in Progress,
Internet-Draft, draft-ietf-suit-manifest-34, 28 May 2025,
<https://datatracker.ietf.org/doc/html/draft-ietf-suit-
manifest-34>.
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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/rfc/rfc2119>.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
May 2017, <https://www.rfc-editor.org/rfc/rfc8174>.
[RFC8610] Birkholz, H., Vigano, C., and C. Bormann, "Concise Data
Definition Language (CDDL): A Notational Convention to
Express Concise Binary Object Representation (CBOR) and
JSON Data Structures", RFC 8610, DOI 10.17487/RFC8610,
June 2019, <https://www.rfc-editor.org/rfc/rfc8610>.
[RFC8949] Bormann, C. and P. Hoffman, "Concise Binary Object
Representation (CBOR)", STD 94, RFC 8949,
DOI 10.17487/RFC8949, December 2020,
<https://www.rfc-editor.org/rfc/rfc8949>.
11.2. Informative References
[I-D.ietf-iotops-7228bis]
Bormann, C., Ersue, M., Keränen, A., and C. Gomez,
"Terminology for Constrained-Node Networks", Work in
Progress, Internet-Draft, draft-ietf-iotops-7228bis-02, 7
July 2025, <https://datatracker.ietf.org/doc/html/draft-
ietf-iotops-7228bis-02>.
[I-D.ietf-suit-update-management]
Moran, B. and K. Takayama, "Update Management Extensions
for Software Updates for Internet of Things (SUIT)
Manifests", Work in Progress, Internet-Draft, draft-ietf-
suit-update-management-09, 17 March 2025,
<https://datatracker.ietf.org/doc/html/draft-ietf-suit-
update-management-09>.
[RFC6024] Reddy, R. and C. Wallace, "Trust Anchor Management
Requirements", RFC 6024, DOI 10.17487/RFC6024, October
2010, <https://www.rfc-editor.org/rfc/rfc6024>.
[RFC9019] Moran, B., Tschofenig, H., Brown, D., and M. Meriac, "A
Firmware Update Architecture for Internet of Things",
RFC 9019, DOI 10.17487/RFC9019, April 2021,
<https://www.rfc-editor.org/rfc/rfc9019>.
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[RFC9124] Moran, B., Tschofenig, H., and H. Birkholz, "A Manifest
Information Model for Firmware Updates in Internet of
Things (IoT) Devices", RFC 9124, DOI 10.17487/RFC9124,
January 2022, <https://www.rfc-editor.org/rfc/rfc9124>.
[RFC9397] Pei, M., Tschofenig, H., Thaler, D., and D. Wheeler,
"Trusted Execution Environment Provisioning (TEEP)
Architecture", RFC 9397, DOI 10.17487/RFC9397, July 2023,
<https://www.rfc-editor.org/rfc/rfc9397>.
Appendix A. A. Full CDDL
To be valid, the following CDDL (see [RFC8610]) MUST be appended to
the SUIT Manifest CDDL. The SUIT CDDL is defined in Appendix A of
[I-D.ietf-suit-manifest]
$$SUIT_Envelope_Extensions //= (
suit-integrated-dependency-key => bstr .cbor SUIT_Envelope)
$$SUIT_Manifest_Extensions //=
(suit-manifest-component-id => SUIT_Component_Identifier)
$$SUIT_severable-members-extensions //=
(suit-dependency-resolution => bstr .cbor SUIT_Command_Sequence)
$$SUIT_severable-members-extensions //=
(suit-candidate-verification => bstr .cbor SUIT_Command_Sequence)
$$unseverable-manifest-member-extensions //=
(suit-uninstall => bstr .cbor SUIT_Command_Sequence)
suit-integrated-dependency-key = tstr
$$severable-manifest-members-choice-extensions //= (
suit-dependency-resolution =>
bstr .cbor SUIT_Command_Sequence / SUIT_Digest)
$$SUIT_Common-extensions //= (
suit-dependencies => SUIT_Dependencies
)
SUIT_Dependencies = {
+ uint => SUIT_Dependency_Metadata
}
SUIT_Dependency_Metadata = {
? suit-dependency-prefix => SUIT_Component_Identifier
* $$SUIT_Dependency_Extensions
}
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SUIT_Condition //= (
suit-condition-dependency-integrity, SUIT_Rep_Policy)
SUIT_Condition //= (
suit-condition-is-dependency, SUIT_Rep_Policy)
SUIT_Directive //= (
suit-directive-process-dependency, SUIT_Rep_Policy)
SUIT_Directive //= (suit-directive-set-parameters,
{+ $$SUIT_Parameters})
SUIT_Directive //= (
suit-directive-unlink, SUIT_Rep_Policy)
suit-manifest-component-id = 5
suit-delegation = 1
suit-dependency-resolution = 15
suit-candidate-verification = 18
suit-uninstall = 24
suit-dependencies = 1
suit-dependency-prefix = 1
suit-condition-dependency-integrity = 7
suit-condition-is-dependency = 8
suit-directive-process-dependency = 11
suit-directive-set-parameters = 19
suit-directive-unlink = 33
Appendix B. B. Examples
The following examples demonstrate a small subset of the
functionalities in this document.
The examples are signed using the following ECDSA secp256r1 key:
-----BEGIN PRIVATE KEY-----
MIGHAgEAMBMGByqGSM49AgEGCCqGSM49AwEHBG0wawIBAQQgApZYjZCUGLM50VBC
CjYStX+09jGmnyJPrpDLTz/hiXOhRANCAASEloEarguqq9JhVxie7NomvqqL8Rtv
P+bitWWchdvArTsfKktsCYExwKNtrNHXi9OB3N+wnAUtszmR23M4tKiW
-----END PRIVATE KEY-----
The corresponding public key can be used to verify these examples:
-----BEGIN PUBLIC KEY-----
MFkwEwYHKoZIzj0CAQYIKoZIzj0DAQcDQgAEhJaBGq4LqqvSYVcYnuzaJr6qi/Eb
bz/m4rVlnIXbwK07HypLbAmBMcCjbazR14vTgdzfsJwFLbM5kdtzOLSolg==
-----END PUBLIC KEY-----
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Each example uses SHA256 as the digest function.
B.1. Example 0: Process Dependency
This example uses functionalities:
* manifest component id
* dependency resolution
* process dependency
The dependency Manifest:
/ SUIT_Envelope_Tagged / 107({
/ authentication-wrapper / 2: << [
<< [
/ digest-algorithm-id: / -16 / SHA256 /,
/ digest-bytes: / h'AEBA316A9A1E38253B29E6C99B605383
68B8AC8B5E6B9ACE1D239970830BBE62'
] >>,
<< / COSE_Sign1_Tagged / 18([
/ protected: / << {
/ algorithm-id / 1: -9 / ESP256 /
} >>,
/ unprotected: / {},
/ payload: / null,
/ signature: / h'3F3E9A2CA98208FEAEAEEADF7E1A0323
C97896ABFB79F91E8D0C1509B0A533CD
0B96BFC876A8F3B8ACE712FFF8EF7EA9
45E62A61E0BA5BD9929E4A1B47EC6475'
]) >>
] >>,
/ manifest / 3: << {
/ manifest-version / 1: 1,
/ manifest-sequence-number / 2: 0,
/ common / 3: << {
/ dependencies / 1: {
/ component-index / 1: {
/ dependency-prefix / 1: [
'dependent.suit'
]
}
},
/ components / 2: [
['10']
]
} >>,
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/ manifest-component-id / 5: [
'depending.suit'
],
/ invoke / 9: << [
/ directive-set-component-index / 12, 0,
/ directive-override-parameters / 20, {
/ parameter-invoke-args / 23: 'cat 00 10'
},
/ directive-invoke / 23, 15
] >>,
/ dependency-resolution / 15: << [
/ directive-set-component-index / 12, 1,
/ directive-override-parameters / 20, {
/ parameter-image-digest / 3: << [
/ digest-algorithm-id: / -16 / SHA256 /,
/ digest-bytes: / h'0F02CAF6D3E61920D36BF3CEA7F862A1
3BB8FB1F09C3F4C29B121FEAB78EF3D8'
] >>,
/ parameter-image-size / 14: 190,
/ parameter-uri / 21: "http://example.com/dependent.suit"
},
/ directive-fetch / 21, 2,
/ condition-image-match / 3, 15
] >>,
/ install / 20: << [
/ directive-set-component-index / 12, 1,
/ directive-override-parameters / 20, {
/ parameter-image-digest / 3: << [
/ digest-algorithm-id: / -16 / SHA256 /,
/ digest-bytes: / h'0F02CAF6D3E61920D36BF3CEA7F862A1
3BB8FB1F09C3F4C29B121FEAB78EF3D8'
] >>
},
/ condition-dependency-integrity / 7, 15,
/ directive-process-dependency / 11, 0,
/ directive-set-component-index / 12, 0,
/ directive-override-parameters / 20, {
/ parameter-content / 18: ' in multiple trust domains'
},
/ directive-write / 18, 15
] >>
} >>
})
Total size of Envelope with COSE authentication object: 373
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D86BA2025873825824822F5820AEBA316A9A1E38253B29E6C99B60538368
B8AC8B5E6B9ACE1D239970830BBE62584AD28443A10128A0F658403F3E9A
2CA98208FEAEAEEADF7E1A0323C97896ABFB79F91E8D0C1509B0A533CD0B
96BFC876A8F3B8ACE712FFF8EF7EA945E62A61E0BA5BD9929E4A1B47EC64
750358F9A70101020003581CA201A101A101814E646570656E64656E742E
7375697402818142313005814E646570656E64696E672E73756974095286
0C0014A11749636174203030203130170F0F5857880C0114A3035824822F
58200F02CAF6D3E61920D36BF3CEA7F862A13BB8FB1F09C3F4C29B121FEA
B78EF3D80E18BE157821687474703A2F2F6578616D706C652E636F6D2F64
6570656E64656E742E737569741502030F1458538E0C0114A1035824822F
58200F02CAF6D3E61920D36BF3CEA7F862A13BB8FB1F09C3F4C29B121FEA
B78EF3D8070F0B000C0014A112581A20696E206D756C7469706C65207472
75737420646F6D61696E73120F
The dependent Manifest (fetched from "https://example.com/
dependent.suit"):
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/ SUIT_Envelope_Tagged / 107({
/ authentication-wrapper / 2: << [
<< [
/ digest-algorithm-id: / -16 / SHA256 /,
/ digest-bytes: / h'0F02CAF6D3E61920D36BF3CEA7F862A1
3BB8FB1F09C3F4C29B121FEAB78EF3D8'
] >>,
<< / COSE_Sign1_Tagged / 18([
/ protected: / << {
/ algorithm-id / 1: -9 / ESP256 /
} >>,
/ unprotected: / {},
/ payload: / null,
/ signature: / h'A25F337126369D2E0B451C01DBD8CDB8
4A77E7F6C39E789DB3D227753494000C
9D250001FDDCA39B4B4E3755A7278C11
998171905F56C394CFBB907105DA804F'
]) >>
] >>,
/ manifest / 3: << {
/ manifest-version / 1: 1,
/ manifest-sequence-number / 2: 0,
/ common / 3: << {
/ components / 2: [
['00']
]
} >>,
/ manifest-component-id / 5: [
'dependent.suit'
],
/ invoke / 9: << [
/ directive-override-parameters / 20, {
/ parameter-invoke-args / 23: 'cat 00'
},
/ directive-invoke / 23, 15
] >>,
/ install / 20: << [
/ directive-override-parameters / 20, {
/ parameter-content / 18: 'hello world'
},
/ directive-write / 18, 15
] >>
} >>
})
Total size of Envelope with COSE authentication object: 190
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D86BA2025873825824822F58200F02CAF6D3E61920D36BF3CEA7F862A13B
B8FB1F09C3F4C29B121FEAB78EF3D8584AD28443A10128A0F65840A25F33
7126369D2E0B451C01DBD8CDB84A77E7F6C39E789DB3D227753494000C9D
250001FDDCA39B4B4E3755A7278C11998171905F56C394CFBB907105DA80
4F035842A6010102000347A102818142303005814E646570656E64656E74
2E73756974094D8414A11746636174203030170F14528414A1124B68656C
6C6F20776F726C64120F
B.2. Example 1: Integrated Dependency
* manifest component id
* dependency resolution
* process dependency
* integrated dependency
/ SUIT_Envelope_Tagged / 107({
/ authentication-wrapper / 2: << [
<< [
/ digest-algorithm-id: / -16 / SHA256 /,
/ digest-bytes: / h'88E1199580864EB1D1AD35EB5925BE68
CA565EE3BB39C27CDB31CEDA4DD667DF'
] >>,
<< / COSE_Sign1_Tagged / 18([
/ protected: / << {
/ algorithm-id / 1: -9 / ESP256 /
} >>,
/ unprotected: / {},
/ payload: / null,
/ signature: / h'074A361F7BBFA2ACF4EC3CFDAF4FDD87
38414BAD672CAEA4F43607BE6031EA90
CB0C283A03C728608B0509C6FD2AFED4
0CFB0C3D341340830A00905E6A729890'
]) >>
] >>,
/ manifest / 3: << {
/ manifest-version / 1: 1,
/ manifest-sequence-number / 2: 0,
/ common / 3: << {
/ dependencies / 1: {
/ component-index / 1: {
/ dependency-prefix / 1: [
'dependent.suit'
]
}
},
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/ components / 2: [
['10']
]
} >>,
/ manifest-component-id / 5: [
'depending.suit'
],
/ invoke / 9: << [
/ directive-set-component-index / 12, 0,
/ directive-override-parameters / 20, {
/ parameter-invoke-args / 23: 'cat 00 10'
},
/ directive-invoke / 23, 15
] >>,
/ dependency-resolution / 15: << [
/ directive-set-component-index / 12, 1,
/ directive-override-parameters / 20, {
/ parameter-image-digest / 3: << [
/ digest-algorithm-id: / -16 / SHA256 /,
/ digest-bytes: / h'0F02CAF6D3E61920D36BF3CEA7F862A1
3BB8FB1F09C3F4C29B121FEAB78EF3D8'
] >>,
/ parameter-image-size / 14: 190,
/ parameter-uri / 21: "#dependent.suit"
},
/ directive-fetch / 21, 2,
/ condition-image-match / 3, 15
] >>,
/ install / 20: << [
/ directive-set-component-index / 12, 1,
/ directive-process-dependency / 11, 0,
/ directive-set-component-index / 12, 0,
/ directive-override-parameters / 20, {
/ parameter-content / 18: ' in multiple trust domains'
},
/ directive-write / 18, 15
] >>
} >>,
"#dependent.suit":
h'D86BA2025873825824822F58200F02CAF6D3E61920D36BF3CEA7F862A13B
B8FB1F09C3F4C29B121FEAB78EF3D8584AD28443A10128A0F65840A25F33
7126369D2E0B451C01DBD8CDB84A77E7F6C39E789DB3D227753494000C9D
250001FDDCA39B4B4E3755A7278C11998171905F56C394CFBB907105DA80
4F035842A6010102000347A102818142303005814E646570656E64656E74
2E73756974094D8414A11746636174203030170F14528414A1124B68656C
6C6F20776F726C64120F'
})
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Total size of Envelope with COSE authentication object: 519
Envelope with COSE authentication object:
D86BA3025873825824822F582088E1199580864EB1D1AD35EB5925BE68CA
565EE3BB39C27CDB31CEDA4DD667DF584AD28443A10128A0F65840074A36
1F7BBFA2ACF4EC3CFDAF4FDD8738414BAD672CAEA4F43607BE6031EA90CB
0C283A03C728608B0509C6FD2AFED40CFB0C3D341340830A00905E6A7298
900358BBA70101020003581CA201A101A101814E646570656E64656E742E
7375697402818142313005814E646570656E64696E672E73756974095286
0C0014A11749636174203030203130170F0F5844880C0114A3035824822F
58200F02CAF6D3E61920D36BF3CEA7F862A13BB8FB1F09C3F4C29B121FEA
B78EF3D80E18BE156F23646570656E64656E742E737569741502030F1458
288A0C010B000C0014A112581A20696E206D756C7469706C652074727573
7420646F6D61696E73120F6F23646570656E64656E742E7375697458BED8
6BA2025873825824822F58200F02CAF6D3E61920D36BF3CEA7F862A13BB8
FB1F09C3F4C29B121FEAB78EF3D8584AD28443A10128A0F65840A25F3371
26369D2E0B451C01DBD8CDB84A77E7F6C39E789DB3D227753494000C9D25
0001FDDCA39B4B4E3755A7278C11998171905F56C394CFBB907105DA804F
035842A6010102000347A102818142303005814E646570656E64656E742E
73756974094D8414A11746636174203030170F14528414A1124B68656C6C
6F20776F726C64120F
Authors' Addresses
Brendan Moran
Arm Limited
Email: brendan.moran.ietf@gmail.com
Ken Takayama
SECOM CO., LTD.
Email: ken.takayama.ietf@gmail.com
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