Trusted Execution Environment Provisioning (TEEP) Protocol
draft-ietf-teep-protocol-10
| Document | Type | Active Internet-Draft (teep WG) | |
|---|---|---|---|
| Authors | Hannes Tschofenig , Mingliang Pei , Dave Wheeler , Dave Thaler , Akira Tsukamoto | ||
| Last updated | 2022-07-28 | ||
| Replaces | draft-tschofenig-teep-protocol | ||
| Stream | Internet Engineering Task Force (IETF) | ||
| Intended RFC status | (None) | ||
| Formats | |||
| Additional resources |
GitHub Repository
C Implementation for encoding/decoding TEEP Protocol messages C Implementation: TEEP protocol and HTTP transport for TEEP TAM server functionality Mailing list discussion |
||
| Stream | WG state | WG Document | |
| Associated WG milestones |
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| Document shepherd | (None) | ||
| IESG | IESG state | I-D Exists | |
| Consensus boilerplate | Unknown | ||
| Telechat date | (None) | ||
| Responsible AD | (None) | ||
| Send notices to | (None) |
draft-ietf-teep-protocol-10
TEEP H. Tschofenig
Internet-Draft Arm Ltd.
Intended status: Standards Track M. Pei
Expires: 29 January 2023 Broadcom
D. Wheeler
Amazon
D. Thaler
Microsoft
A. Tsukamoto
AIST
28 July 2022
Trusted Execution Environment Provisioning (TEEP) Protocol
draft-ietf-teep-protocol-10
Abstract
This document specifies a protocol that installs, updates, and
deletes Trusted Components in a device with a Trusted Execution
Environment (TEE). This specification defines an interoperable
protocol for managing the lifecycle of Trusted Components.
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet-
Drafts is at https://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
This Internet-Draft will expire on 29 January 2023.
Copyright Notice
Copyright (c) 2022 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents (https://trustee.ietf.org/
license-info) in effect on the date of publication of this document.
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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 Simplified BSD License text
as described in Section 4.e of the Trust Legal Provisions and are
provided without warranty as described in the Simplified BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 4
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4
3. Message Overview . . . . . . . . . . . . . . . . . . . . . . 5
4. Detailed Messages Specification . . . . . . . . . . . . . . . 6
4.1. Creating and Validating TEEP Messages . . . . . . . . . . 6
4.1.1. Creating a TEEP message . . . . . . . . . . . . . . . 6
4.1.2. Validating a TEEP Message . . . . . . . . . . . . . . 7
4.2. QueryRequest Message . . . . . . . . . . . . . . . . . . 7
4.3. QueryResponse Message . . . . . . . . . . . . . . . . . . 9
4.3.1. Evidence and Attestation Results . . . . . . . . . . 13
4.4. Update Message . . . . . . . . . . . . . . . . . . . . . 14
4.4.1. Example 1: Having one SUIT Manifest pointing to a URI
of a Trusted Component Binary . . . . . . . . . . . . 16
4.4.2. Example 2: Having a SUIT Manifest include the Trusted
Component Binary . . . . . . . . . . . . . . . . . . 19
4.4.3. Example 3: Supplying Personalization Data for the
Trusted Component Binary . . . . . . . . . . . . . . 20
4.4.4. Example 4: Unlinking Trusted Component . . . . . . . 22
4.5. Success Message . . . . . . . . . . . . . . . . . . . . . 23
4.6. Error Message . . . . . . . . . . . . . . . . . . . . . . 24
5. EAT Profile . . . . . . . . . . . . . . . . . . . . . . . . . 27
6. Mapping of TEEP Message Parameters to CBOR Labels . . . . . . 29
7. Behavior Specification . . . . . . . . . . . . . . . . . . . 31
7.1. TAM Behavior . . . . . . . . . . . . . . . . . . . . . . 31
7.1.1. Handling a QueryResponse Message . . . . . . . . . . 31
7.1.1.1. Handling an Attestation Result . . . . . . . . . 32
7.1.2. Handling a Success or Error Message . . . . . . . . . 33
7.2. TEEP Agent Behavior . . . . . . . . . . . . . . . . . . . 33
8. Cipher Suites . . . . . . . . . . . . . . . . . . . . . . . . 34
9. Freshness Mechanisms . . . . . . . . . . . . . . . . . . . . 36
10. Security Considerations . . . . . . . . . . . . . . . . . . . 36
11. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 38
11.1. Media Type Registration . . . . . . . . . . . . . . . . 38
12. References . . . . . . . . . . . . . . . . . . . . . . . . . 39
12.1. Normative References . . . . . . . . . . . . . . . . . . 39
12.2. Informative References . . . . . . . . . . . . . . . . . 41
A. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 42
B. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 42
C. Complete CDDL . . . . . . . . . . . . . . . . . . . . . . . . 43
D. Examples of Diagnostic Notation and Binary Representation . . 46
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D.1. QueryRequest Message . . . . . . . . . . . . . . . . . . 47
D.1.1. CBOR Diagnostic Notation . . . . . . . . . . . . . . 47
D.1.2. CBOR Binary Representation . . . . . . . . . . . . . 47
D.2. Entity Attestation Token . . . . . . . . . . . . . . . . 48
D.2.1. CBOR Diagnostic Notation . . . . . . . . . . . . . . 48
D.3. QueryResponse Message . . . . . . . . . . . . . . . . . . 49
D.3.1. CBOR Diagnostic Notation . . . . . . . . . . . . . . 49
D.3.2. CBOR Binary Representation . . . . . . . . . . . . . 49
D.4. Update Message . . . . . . . . . . . . . . . . . . . . . 50
D.4.1. CBOR Diagnostic Notation . . . . . . . . . . . . . . 50
D.4.2. CBOR Binary Representation . . . . . . . . . . . . . 50
D.5. Success Message . . . . . . . . . . . . . . . . . . . . . 51
D.5.1. CBOR Diagnostic Notation . . . . . . . . . . . . . . 51
D.5.2. CBOR Binary Representation . . . . . . . . . . . . . 51
D.6. Error Message . . . . . . . . . . . . . . . . . . . . . . 51
D.6.1. CBOR Diagnostic Notation . . . . . . . . . . . . . . 51
D.6.2. CBOR binary Representation . . . . . . . . . . . . . 51
E. Examples of SUIT Manifests . . . . . . . . . . . . . . . . . 52
Example 1: SUIT Manifest pointing to URI of the Trusted Component
Binary . . . . . . . . . . . . . . . . . . . . . . . . . 52
CBOR Diagnostic Notation of SUIT Manifest . . . . . . . . . . 52
CBOR Binary Representation . . . . . . . . . . . . . . . . . 53
CBOR Binary in Hex . . . . . . . . . . . . . . . . . . . . . 55
Example 2: SUIT Manifest including the Trusted Component
Binary . . . . . . . . . . . . . . . . . . . . . . . . . 56
CBOR Diagnostic Notation of SUIT Manifest . . . . . . . . . . 56
CBOR Binary Representation . . . . . . . . . . . . . . . . . 57
CBOR Binary in Hex . . . . . . . . . . . . . . . . . . . . . 58
Example 3: Supplying Personalization Data for Trusted Component
Binary . . . . . . . . . . . . . . . . . . . . . . . . . 59
CBOR Diagnostic Notation of SUIT Manifest . . . . . . . . . . 59
CBOR Binary Represenation . . . . . . . . . . . . . . . . . . 60
CBOR Binary in Hex . . . . . . . . . . . . . . . . . . . . . 63
E.4. Example 4: Unlink a Trusted Component . . . . . . . . . . 63
CBOR Diagnostic Notation of SUIT Manifest . . . . . . . . . . 63
CBOR Binary Representation . . . . . . . . . . . . . . . . . 64
CBOR Binary in Hex . . . . . . . . . . . . . . . . . . . . . 66
F. Examples of SUIT Reports . . . . . . . . . . . . . . . . . . 66
F.1. Example 1: Success . . . . . . . . . . . . . . . . . . . 66
F.2. Example 2: Faiure . . . . . . . . . . . . . . . . . . . . 67
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 68
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1. Introduction
The Trusted Execution Environment (TEE) concept has been designed to
separate a regular operating system, also referred as a Rich
Execution Environment (REE), from security-sensitive applications.
In a TEE ecosystem, device vendors may use different operating
systems in the REE and may use different types of TEEs. When Trusted
Component Developers or Device Administrators use Trusted Application
Managers (TAMs) to install, update, and delete Trusted Applications
and their dependencies on a wide range of devices with potentially
different TEEs then an interoperability need arises.
This document specifies the protocol for communicating between a TAM
and a TEEP Agent.
The Trusted Execution Environment Provisioning (TEEP) architecture
document [I-D.ietf-teep-architecture] provides design guidance and
introduces the necessary terminology.
2. 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.
This specification re-uses the terminology defined in
[I-D.ietf-teep-architecture].
As explained in Section 4.4 of that document, the TEEP protocol
treats each Trusted Application (TA), any dependencies the TA has,
and personalization data as separate components that are expressed in
SUIT manifests, and a SUIT manifest might contain or reference
multiple binaries (see [I-D.ietf-suit-manifest] for more details).
As such, the term Trusted Component (TC) in this document refers to a
set of binaries expressed in a SUIT manifest, to be installed in a
TEE. Note that a Trusted Component may include one or more TAs and/
or configuration data and keys needed by a TA to operate correctly.
Each Trusted Component is uniquely identified by a SUIT Component
Identifier (see [I-D.ietf-suit-manifest] Section 8.7.2.2).
Attestation related terms, such as Evidence and Attestation Results,
are as defined in [I-D.ietf-rats-architecture].
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3. Message Overview
The TEEP protocol consists of messages exchanged between a TAM and a
TEEP Agent. The messages are encoded in CBOR and designed to provide
end-to-end security. TEEP protocol messages are signed by the
endpoints, i.e., the TAM and the TEEP Agent, but Trusted Applications
may also be encrypted and signed by a Trusted Component Developer or
Device Administrator. The TEEP protocol not only uses CBOR but also
the respective security wrapper, namely COSE [RFC8152]. Furthermore,
for software updates the SUIT manifest format
[I-D.ietf-suit-manifest] is used, and for attestation the Entity
Attestation Token (EAT) [I-D.ietf-rats-eat] format is supported
although other attestation formats are also permitted.
This specification defines five messages: QueryRequest,
QueryResponse, Update, Success, and Error.
A TAM queries a device's current state with a QueryRequest message.
A TEEP Agent will, after authenticating and authorizing the request,
report attestation information, list all Trusted Components, and
provide information about supported algorithms and extensions in a
QueryResponse message. An error message is returned if the request
could not be processed. A TAM will process the QueryResponse message
and determine whether to initiate subsequent message exchanges to
install, update, or delete Trusted Applications.
+------------+ +-------------+
| TAM | |TEEP Agent |
+------------+ +-------------+
QueryRequest ------->
QueryResponse
<------- or
Error
With the Update message a TAM can instruct a TEEP Agent to install
and/or delete one or more Trusted Components. The TEEP Agent will
process the message, determine whether the TAM is authorized and
whether the Trusted Component has been signed by an authorized
Trusted Component Signer. A Success message is returned when the
operation has been completed successfully, or an Error message
otherwise.
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+------------+ +-------------+
| TAM | |TEEP Agent |
+------------+ +-------------+
Update ---->
Success
<---- or
Error
4. Detailed Messages Specification
TEEP messages are protected by the COSE_Sign1 structure. The TEEP
protocol messages are described in CDDL format [RFC8610] below.
{
teep-message => (query-request /
query-response /
update /
teep-success /
teep-error ),
}
4.1. Creating and Validating TEEP Messages
4.1.1. Creating a TEEP message
To create a TEEP message, the following steps are performed.
1. Create a TEEP message according to the description below and
populate it with the respective content. TEEP messages sent by
TAMs (QueryRequest and Update) can include a "token". The TAM
can decide, in any implementation-specific way, whether to
include a token in a message. The first usage of a token
generated by a TAM MUST be randomly created. Subsequent token
values MUST be different for each subsequent message created by a
TAM.
2. Create a COSE Header containing the desired set of Header
Parameters. The COSE Header MUST be valid per the [RFC8152]
specification.
3. Create a COSE_Sign1 object using the TEEP message as the
COSE_Sign1 Payload; all steps specified in [RFC8152] for creating
a COSE_Sign1 object MUST be followed.
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4.1.2. Validating a TEEP Message
When TEEP message is received (see the ProcessTeepMessage conceptual
API defined in [I-D.ietf-teep-architecture] section 6.2.1), the
following validation steps are performed. If any of the listed steps
fail, then the TEEP message MUST be rejected.
1. Verify that the received message is a valid CBOR object.
2. Verify that the message contains a COSE_Sign1 structure.
3. Verify that the resulting COSE Header includes only parameters
and values whose syntax and semantics are both understood and
supported or that are specified as being ignored when not
understood.
4. Follow the steps specified in Section 4 of [RFC8152] ("Signing
Objects") for validating a COSE_Sign1 object. The COSE_Sign1
payload is the content of the TEEP message.
5. Verify that the TEEP message is a valid CBOR map and verify the
fields of the TEEP message according to this specification.
4.2. QueryRequest Message
A QueryRequest message is used by the TAM to learn information from
the TEEP Agent, such as the features supported by the TEEP Agent,
including cipher suites and protocol versions. Additionally, the TAM
can selectively request data items from the TEEP Agent via the
request parameter. Currently, the following features are supported:
* Request for attestation information,
* Listing supported extensions,
* Querying installed Trusted Components, and
* Listing supported SUIT commands.
Like other TEEP messages, the QueryRequest message is signed, and the
relevant CDDL snippet is shown below. The complete CDDL structure is
shown in Appendix C.
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query-request = [
type: TEEP-TYPE-query-request,
options: {
? token => bstr .size (8..64),
? supported-freshness-mechanisms => [ + $freshness-mechanism ],
? challenge => bstr .size (8..512),
? versions => [ + version ],
* $$query-request-extensions
* $$teep-option-extensions
},
supported-cipher-suites: [ + $cipher-suite ],
data-item-requested: data-item-requested
]
The message has the following fields:
type
The value of (1) corresponds to a QueryRequest message sent from
the TAM to the TEEP Agent.
token
The value in the token parameter is used to match responses to
requests. This is particularly useful when a TAM issues multiple
concurrent requests to a TEEP Agent. The token MUST be present if
and only if the attestation bit is clear in the data-item-
requested value. The size of the token is at least 8 bytes (64
bits) and maximum of 64 bytes, which is the same as in an EAT
Nonce Claim (see [I-D.ietf-rats-eat] Section 3.3). The first
usage of a token generated by a TAM MUST be randomly created.
Subsequent token values MUST be different for each request message
to distinguish the correct response from multiple requests. The
token value MUST NOT be used for other purposes, such as a TAM to
identify the devices and/or a device to identify TAMs or Trusted
Components. The TAM SHOULD set an expiration time for each token
and MUST ignore any messages with expired tokens. The TAM MUST
expire the token value after receiving the first response
containing the token value and ignore any subsequent messages that
have the same token value.
supported-cipher-suites
The supported-cipher-suites parameter lists the cipher suites
supported by the TAM. Details about the cipher suite encoding can
be found in Section 8.
data-item-requested
The data-item-requested parameter indicates what information the
TAM requests from the TEEP Agent in the form of a bitmap.
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attestation (1) With this value the TAM requests the TEEP Agent
to return an attestation payload, whether Evidence (e.g., an
EAT) or an Attestation Result, in the response.
trusted-components (2) With this value the TAM queries the TEEP
Agent for all installed Trusted Components.
extensions (4) With this value the TAM queries the TEEP Agent for
supported capabilities and extensions, which allows a TAM to
discover the capabilities of a TEEP Agent implementation.
suit-reports (8) With this value the TAM requests the TEEP Agent
to return SUIT Reports in the response.
Further values may be added in the future.
supported-freshness-mechanisms
The supported-freshness-mechanisms parameter lists the freshness
mechanism(s) supported by the TAM. Details about the encoding can
be found in Section 9. If this parameter is absent, it means only
the nonce mechanism is supported.
challenge
The challenge field is an optional parameter used for ensuring the
freshness of the attestation payload returned with a QueryResponse
message. It MUST be absent if the attestation bit is clear (since
the token is used instead in that case). When a challenge is
provided in the QueryRequest and an EAT is returned with a
QueryResponse message then the challenge contained in this request
MUST be used to generate the EAT, such as by copying the challenge
into the nonce claim found in the EAT if using the Nonce freshness
mechanism. For more details see Section 9. If any format other
than EAT is used, it is up to that format to define the use of the
challenge field.
versions
The versions parameter enumerates the TEEP protocol version(s)
supported by the TAM. A value of 0 refers to the current version
of the TEEP protocol. If this field is not present, it is to be
treated the same as if it contained only version 0.
4.3. QueryResponse Message
The QueryResponse message is the successful response by the TEEP
Agent after receiving a QueryRequest message. As discussed in
Section 7.2, it can also be sent unsolicited if the contents of the
QueryRequest are already known and do not vary per message.
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Like other TEEP messages, the QueryResponse message is signed, and
the relevant CDDL snippet is shown below. The complete CDDL
structure is shown in Appendix C.
query-response = [
type: TEEP-TYPE-query-response,
options: {
? token => bstr .size (8..64),
? selected-cipher-suite => $cipher-suite,
? selected-version => version,
? attestation-payload-format => text,
? attestation-payload => bstr,
? suit-reports => [ + SUIT_Report ],
? tc-list => [ + system-property-claims ],
? requested-tc-list => [ + requested-tc-info ],
? unneeded-tc-list => [ + SUIT_Component_Identifier ],
? ext-list => [ + ext-info ],
* $$query-response-extensions,
* $$teep-option-extensions
}
]
requested-tc-info = {
component-id => SUIT_Component_Identifier,
? tc-manifest-sequence-number => .within uint .size 8
? have-binary => bool
}
The QueryResponse message has the following fields:
type
The value of (2) corresponds to a QueryResponse message sent from
the TEEP Agent to the TAM.
token
The value in the token parameter is used to match responses to
requests. The value MUST correspond to the value received with
the QueryRequest message if one was present, and MUST be absent if
no token was present in the QueryRequest.
selected-cipher-suite
The selected-cipher-suite parameter indicates the selected cipher
suite. If this parameter is not present, it is to be treated as
if the TEEP Agent accepts any cipher suites listed in the
QueryRequest, so the TAM can select one. Details about the cipher
suite encoding can be found in Section 8.
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selected-version
The selected-version parameter indicates the TEEP protocol version
selected by the TEEP Agent. The absence of this parameter
indicates the same as if it was present with a value of 0.
attestation-payload-format
The attestation-payload-format parameter indicates the IANA Media
Type of the attestation-payload parameter, where media type
parameters are permitted after the media type. The absence of
this parameter indicates that the format is "application/eat-cwt;
profile=https://datatracker.ietf.org/doc/html/draft-ietf-teep-
protocol-10" (see [I-D.lundblade-rats-eat-media-type] for further
discussion). (RFC-editor: upon RFC publication, replace URI above
with "https://www.rfc-editor.org/info/rfcXXXX" where XXXX is the
RFC number of this document.) It MUST be present if the
attestation-payload parameter is present and the format is not an
EAT in CWT format with the profile defined below in Section 5.
attestation-payload
The attestation-payload parameter contains Evidence or an
Attestation Result. This parameter MUST be present if the
QueryResponse is sent in response to a QueryRequest with the
attestation bit set. If the attestation-payload-format parameter
is absent, the attestation payload contained in this parameter
MUST be an Entity Attestation Token following the encoding defined
in [I-D.ietf-rats-eat]. See Section 4.3.1 for further discussion.
suit-reports
If present, the suit-reports parameter contains a set of "boot"
(including starting an executable in an OS context) time SUIT
Reports as defined in Section 4 of [I-D.ietf-suit-report]. If a
token parameter was present in the QueryRequest message the
QueryResponse message is in response to, the suit-report-nonce
field MUST be present in the SUIT Report with a value matching the
token parameter in the QueryRequest message. SUIT Reports can be
useful in QueryResponse messages to pass information to the TAM
without depending on a Verifier including the relevant information
in Attestation Results.
tc-list
The tc-list parameter enumerates the Trusted Components installed
on the device in the form of system-property-claims objects, as
defined in Section 4 of [I-D.ietf-suit-report]. The system-
property-claims can be used to learn device identifying
information and TEE identifying information for distinguishing
which Trusted Components to install in the TEE. This parameter
MUST be present if the QueryResponse is sent in response to a
QueryRequest with the trusted-components bit set.
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requested-tc-list
The requested-tc-list parameter enumerates the Trusted Components
that are not currently installed in the TEE, but which are
requested to be installed, for example by an installer of an
Untrusted Application that has a TA as a dependency, or by a
Trusted Application that has another Trusted Component as a
dependency. Requested Trusted Components are expressed in the
form of requested-tc-info objects. A TEEP Agent can get this
information from the RequestTA conceptual API defined in
[I-D.ietf-teep-architecture] section 6.2.1.
unneeded-tc-list
The unneeded-tc-list parameter enumerates the Trusted Components
that are currently installed in the TEE, but which are no longer
needed by any other application. The TAM can use this information
in determining whether a Trusted Component can be deleted. Each
unneeded Trusted Component is identified by its SUIT Component
Identifier. A TEEP Agent can get this information from the
UnrequestTA conceptual API defined in [I-D.ietf-teep-architecture]
section 6.2.1.
ext-list
The ext-list parameter lists the supported extensions. This
document does not define any extensions. This parameter MUST be
present if the QueryResponse is sent in response to a QueryRequest
with the extensions bit set.
The requested-tc-info message has the following fields:
component-id
A SUIT Component Identifier.
tc-manifest-sequence-number
The minimum suit-manifest-sequence-number value from a SUIT
manifest for the Trusted Component. If not present, indicates
that any sequence number will do.
have-binary
If present with a value of true, indicates that the TEEP agent
already has the Trusted Component binary and only needs an Update
message with a SUIT manifest that authorizes installing it. If
have-binary is true, the tc-manifest-sequence-number field MUST be
present.
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4.3.1. Evidence and Attestation Results
Section 7 of [I-D.ietf-teep-architecture] lists information that may
appear in Evidence depending on the circumstance. However, the
Evidence is opaque to the TEEP protocol and there are no formal
requirements on the contents of Evidence.
TAMs however consume Attestation Results and do need enough
information therein to make decisions on how to remediate a TEE that
is out of compliance, or update a TEE that is requesting an
authorized change. To do so, the information in Section 7 of
[I-D.ietf-teep-architecture] is often required depending on the
policy. When an Entity Attestation Token is used, the following
claims can be used to meet those requirements, whether these claims
appear in Attestation Results, or in Evidence for the Verifier to use
when generating Attestation Results of some form:
+=================+==================+=====================+
| Requirement | Claim | Reference |
+=================+==================+=====================+
| Freshness proof | nonce | [I-D.ietf-rats-eat] |
| | | section 4.1 |
+-----------------+------------------+---------------------+
| Device unique | ueid | [I-D.ietf-rats-eat] |
| identifier | | section 4.2.1 |
+-----------------+------------------+---------------------+
| Vendor of the | oemid | [I-D.ietf-rats-eat] |
| device | | section 4.2.3 |
+-----------------+------------------+---------------------+
| Class of the | hardware-model | [I-D.ietf-rats-eat] |
| device | | section 4.2.4 |
+-----------------+------------------+---------------------+
| TEE hardware | hardware-version | [I-D.ietf-rats-eat] |
| type | | section 4.2.5 |
+-----------------+------------------+---------------------+
| TEE hardware | hardware-version | [I-D.ietf-rats-eat] |
| version | | section 4.2.5 |
+-----------------+------------------+---------------------+
| TEE firmware | manifests | [I-D.ietf-rats-eat] |
| type | | section 4.2.16 |
+-----------------+------------------+---------------------+
| TEE firmware | manifests | [I-D.ietf-rats-eat] |
| version | | section 4.2.16 |
+-----------------+------------------+---------------------+
Table 1
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The "manifests" claim should include information about the TEEP Agent
as well as any of its dependencies such as firmware.
4.4. Update Message
The Update message is used by the TAM to install and/or delete one or
more Trusted Components via the TEEP Agent. It can also be used to
pass a successful Attestation Report back to the TEEP Agent when the
TAM is configured as an intermediary between the TEEP Agent and a
Verifier, as shown in the figure below, where the Attestation Result
passed back to the Attester can be used as a so-called "passport"
(see section 5.1 of [I-D.ietf-rats-architecture]) that can be
presented to other Relying Parties.
+---------------+
| Verifier |
+---------------+
^ | Attestation
Evidence | v Result
+---------------+
| TAM / |
| Relying Party |
+---------------+
QueryResponse ^ | Update
(Evidence) | | (Attestation
| v Result)
+---------------+ +---------------+
| TEEP Agent |------------>| Other |
| / Attester | Attestation | Relying Party |
+---------------+ Result +---------------+
Figure 1: Example use of TEEP and attestation
Like other TEEP messages, the Update message is signed, and the
relevant CDDL snippet is shown below. The complete CDDL structure is
shown in Appendix C.
update = [
type: TEEP-TYPE-update,
options: {
? token => bstr .size (8..64),
? manifest-list => [ + bstr .cbor SUIT_Envelope ],
? attestation-payload-format => text,
? attestation-payload => bstr,
* $$update-extensions,
* $$teep-option-extensions
}
]
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The Update message has the following fields:
type
The value of (3) corresponds to an Update message sent from the
TAM to the TEEP Agent. In case of successful processing, a
Success message is returned by the TEEP Agent. In case of an
error, an Error message is returned. Note that the Update message
is used for initial Trusted Component installation as well as for
updates and deletes.
token
The value in the token field is used to match responses to
requests.
manifest-list
The manifest-list field is used to convey one or multiple SUIT
manifests to install. A manifest is a bundle of metadata about a
Trusted Component, such as where to find the code, the devices to
which it applies, and cryptographic information protecting the
manifest. The manifest may also convey personalization data.
Trusted Component binaries and personalization data can be signed
and encrypted by the same Trusted Component Signer. Other
combinations are, however, possible as well. For example, it is
also possible for the TAM to sign and encrypt the personalization
data and to let the Trusted Component Developer sign and/or
encrypt the Trusted Component binary.
attestation-payload-format
The attestation-payload-format parameter indicates the IANA Media
Type of the attestation-payload parameter, where media type
parameters are permitted after the media type. The absence of
this parameter indicates that the format is "application/eat-cwt;
profile=https://datatracker.ietf.org/doc/html/draft-ietf-teep-
protocol-10" (see [I-D.lundblade-rats-eat-media-type] for further
discussion). (RFC-editor: upon RFC publication, replace URI above
with "https://www.rfc-editor.org/info/rfcXXXX" where XXXX is the
RFC number of this document.) It MUST be present if the
attestation-payload parameter is present and the format is not an
EAT in CWT format with the profile defined below in Section 5.
attestation-payload
The attestation-payload parameter contains an Attestation Result.
This parameter If the attestation-payload-format parameter is
absent, the attestation payload contained in this parameter MUST
be an Entity Attestation Token following the encoding defined in
[I-D.ietf-rats-eat]. See Section 4.3.1 for further discussion.
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Note that an Update message carrying one or more SUIT manifests will
inherently involve multiple signatures, one by the TAM in the TEEP
message and one from a Trusted Component Signer inside each manifest.
This is intentional as they are for different purposes.
The TAM is what authorizes apps to be installed, updated, and deleted
on a given TEE and so the TEEP signature is checked by the TEEP Agent
at protocol message processing time. (This same TEEP security
wrapper is also used on messages like QueryRequest so that Agents
only send potentially sensitive data such as Evidence to trusted
TAMs.)
The Trusted Component signer on the other hand is what authorizes the
Trusted Component to actually run, so the manifest signature could be
checked at install time or load (or run) time or both, and this
checking is done by the TEE independent of whether TEEP is used or
some other update mechanism. See section 5 of
[I-D.ietf-teep-architecture] for further discussion.
The Update Message has a SUIT_Envelope containing SUIT manifests.
Following are some examples of using SUIT manifests in the Update
Message.
4.4.1. Example 1: Having one SUIT Manifest pointing to a URI of a
Trusted Component Binary
In this example, a SUIT Manifest has a URI pointing to a Trusted
Component Binary.
A Trusted Component Developer creates a new Trusted Component Binary
and hosts it at a Trusted Component Developer's URI. Then the
Trusted Component Developer generates an associated SUIT manifest
with the filename "tc-uuid.suit" that contains the URI. The filename
"tc-uuid.suit" is used in Example 3 later.
The TAM receives the latest SUIT manifest from the Trusted Component
Developer, and the URI it contains will not be changeable by the TAM
since the SUIT manifest is signed by the Trusted Component Developer.
Pros:
* The Trusted Component Developer can ensure that the intact Trusted
Component Binary is downloaded by devices
* The TAM does not have to send large Update messages containing the
Trusted Component Binary
Cons:
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* The Trusted Component Developer must host the Trusted Component
Binary server
* The device must fetch the Trusted Component Binary in another
connection after receiving an Update message
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+------------+ +-------------+
| TAM | | TEEP Agent |
+------------+ +-------------+
Update ---->
+=================== teep-protocol(TAM) ==================+
| TEEP_Message([ |
| TEEP-TYPE-update, |
| options: { |
| manifest-list: [ |
| += suit-manifest "tc-uuid.suit" (TC Developer) =+ |
| | SUIT_Envelope({ | |
| | manifest: { | |
| | install: { | |
| | set-parameter: { | |
| | uri: "https://example.org/tc-uuid.ta" | |
| | }, | |
| | fetch | |
| | } | |
| | } | |
| | }) | |
| +===============================================+ |
| ] |
| } |
| ]) |
+=========================================================+
and then,
+-------------+ +--------------+
| TEEP Agent | | TC Developer |
+-------------+ +--------------+
<----
fetch "https://example.org/tc-uuid.ta"
+======= tc-uuid.ta =======+
| 48 65 6C 6C 6F 2C 20 ... |
+==========================+
Figure 2: URI of the Trusted Component Binary
For the full SUIT Manifest example binary, see Appendix "Example 1:
SUIT Manifest pointing to URI of the Trusted Component Binary".
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4.4.2. Example 2: Having a SUIT Manifest include the Trusted Component
Binary
In this example, the SUIT manifest contains the entire Trusted
Component Binary using the integrated-payload (see
[I-D.ietf-suit-manifest] Section 7.6).
A Trusted Component Developer delegates to the TAM the task of
delivering the Trusted Component Binary in the SUIT manifest. The
Trusted Component Developer creates a SUIT manifest and embeds the
Trusted Component Binary, which is referenced in the URI parameter
with identifier "#tc". The Trusted Component Developer provides the
SUIT manifest to the TAM.
The TAM serves the SUIT manifest containing the Trusted Component
Binary to the device in an Update message.
Pros:
* The device can obtain the Trusted Component Binary and its SUIT
manifest together in one Update message
* The Trusted Component Developer does not have to host a server to
deliver the Trusted Component Binary directly to devices
Cons:
* The TAM must host the Trusted Component Binary itself, rather than
delegating such storage to the Trusted Component Developer
* The TAM must deliver Trusted Component Binaries in Update
messages, which result in increased Update message size
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+------------+ +-------------+
| TAM | | TEEP Agent |
+------------+ +-------------+
Update ---->
+=========== teep-protocol(TAM) ============+
| TEEP_Message([ |
| TEEP-TYPE-update, |
| options: { |
| manifest-list: [ |
| +== suit-manifest(TC Developer) ==+ |
| | SUIT_Envelope({ | |
| | "#tc": h'48 65 6C 6C ...', | |
| | manifest: { | |
| | install: { | |
| | set-parameter: { | |
| | uri: "#tc" | |
| | }, | |
| | fetch | |
| | } | |
| | } | |
| | }) | |
| +=================================+ |
| ] |
| } |
| ]) |
+===========================================+
Figure 3: Integrated Payload with Trusted Component Binary
For the full SUIT Manifest example binary, see Appendix "Example 2:
SUIT Manifest including the Trusted Component Binary".
4.4.3. Example 3: Supplying Personalization Data for the Trusted
Component Binary
In this example, Personalization Data is associated with the Trusted
Component Binary "tc-uuid.suit" from Example 1.
The Trusted Component Developer places Personalization Data in a file
named "config.json" and hosts it on an HTTPS server. The Trusted
Component Developer then creates a SUIT manifest with the URI,
specifying which Trusted Component Binary it correlates to in the
parameter 'dependency-resolution', and signs the SUIT manifest.
The TAM delivers the SUIT manifest of the Personalization Data which
depends on the Trusted Component Binary from Example 1.
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+------------+ +-------------+
| TAM | | TEEP Agent |
+------------+ +-------------+
Update ---->
+================= teep-protocol(TAM) ======================+
| TEEP_Message([ |
| TEEP-TYPE-update, |
| options: { |
| manifest-list: [ |
| +======== suit-manifest(TC Developer) ============+ |
| | SUIT_Envelope({ | |
| | manifest: { | |
| | common: { | |
| | dependencies: [ | |
| | {{digest-of-tc.suit}} | |
| | ] | |
| | } | |
| | dependency-resolution: { | |
| | set-parameter: { | |
| | uri: "https://example.org/tc-uuid.suit" | |
| | } | |
| | fetch | |
| | } | |
| | install: { | |
| | set-parameter: { | |
| | uri: "https://example.org/config.json" | |
| | }, | |
| | fetch | |
| | set-dependency-index | |
| | process-dependency | |
| | } | |
| | } | |
| | }) | |
| +=================================================+ |
| ] |
| } |
| ]) |
+===========================================================+
and then,
+-------------+ +--------------+
| TEEP Agent | | TC Developer |
+-------------+ +--------------+
<----
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fetch "https://example.org/config.json"
+=======config.json========+
| 7B 22 75 73 65 72 22 ... |
+==========================+
Figure 4: Personalization Data
For the full SUIT Manifest example binary, see Appendix "Example 3:
Supplying Personalization Data for Trusted Component Binary".
4.4.4. Example 4: Unlinking Trusted Component
This subsection shows an example deleting the Trusted Component
Binary in the TEEP Device.
A Trusted Component Developer can also generate SUIT Manifest which
unlinks the installed Trusted Component. The TAM deliver it when the
TAM want to uninstall the component.
The directive-unlink (see [I-D.ietf-suit-trust-domains] Section-
6.5.4) is located in the manifest to delete the Trusted Component.
Note that in case other Trusted Components depend on it, i.e. the
reference count is not zero, the TEEP Device SHOULD NOT delete it
immediately.
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+------------+ +-------------+
| TAM | | TEEP Agent |
+------------+ +-------------+
Update ---->
+=========== teep-protocol(TAM) ============+
| TEEP_Message([ |
| TEEP-TYPE-update, |
| options: { |
| manifest-list: [ |
| +== suit-manifest(TC Developer) ==+ |
| | SUIT_Envelope({ | |
| | manifest: { | |
| | install: [ | |
| | unlink | |
| | ] | |
| | } | |
| | }) | |
| +=================================+ |
| ] |
| } |
| ]) |
+===========================================+
Figure 5: Unlink Trusted Component example (summary)
For the full SUIT Manifest example binary, see Appendix E. SUIT
Example 4 (Appendix "E.4. Example 4: Unlink a Trusted Component")
4.5. Success Message
The Success message is used by the TEEP Agent to return a success in
response to an Update message.
Like other TEEP messages, the Success message is signed, and the
relevant CDDL snippet is shown below. The complete CDDL structure is
shown in Appendix C.
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teep-success = [
type: TEEP-TYPE-teep-success,
options: {
? token => bstr .size (8..64),
? msg => text .size (1..128),
? suit-reports => [ + SUIT_Report ],
* $$teep-success-extensions,
* $$teep-option-extensions
}
]
The Success message has the following fields:
type
The value of (5) corresponds to corresponds to a Success message
sent from the TEEP Agent to the TAM.
token
The value in the token parameter is used to match responses to
requests. It MUST match the value of the token parameter in the
Update message the Success is in response to, if one was present.
If none was present, the token MUST be absent in the Success
message.
msg
The msg parameter contains optional diagnostics information
encoded in UTF-8 [RFC3629] using Net-Unicode form [RFC5198] with
max 128 bytes returned by the TEEP Agent.
suit-reports
If present, the suit-reports parameter contains a set of SUIT
Reports as defined in Section 4 of [I-D.ietf-suit-report]. If a
token parameter was present in the Update message the Success
message is in response to, the suit-report-nonce field MUST be
present in the SUIT Report with a value matching the token
parameter in the Update message.
4.6. Error Message
The Error message is used by the TEEP Agent to return an error in
response to an Update message.
Like other TEEP messages, the Error message is signed, and the
relevant CDDL snippet is shown below. The complete CDDL structure is
shown in Appendix C.
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teep-error = [
type: TEEP-TYPE-teep-error,
options: {
? token => bstr .size (8..64),
? err-msg => text .size (1..128),
? supported-cipher-suites => [ + $cipher-suite ],
? supported-freshness-mechanisms => [ + $freshness-mechanism ],
? versions => [ + version ],
? suit-reports => [ + SUIT_Report ],
* $$teep-error-extensions,
* $$teep-option-extensions
},
err-code: uint (0..23)
]
The Error message has the following fields:
type
The value of (6) corresponds to an Error message sent from the
TEEP Agent to the TAM.
token
The value in the token parameter is used to match responses to
requests. It MUST match the value of the token parameter in the
Update message the Success is in response to, if one was present.
If none was present, the token MUST be absent in the Error
message.
err-msg
The err-msg parameter is human-readable diagnostic text that MUST
be encoded using UTF-8 [RFC3629] using Net-Unicode form [RFC5198]
with max 128 bytes.
supported-cipher-suites
The supported-cipher-suites parameter lists the cipher suite(s)
supported by the TEEP Agent. Details about the cipher suite
encoding can be found in Section 8. This otherwise optional
parameter MUST be returned if err-code is
ERR_UNSUPPORTED_CIPHER_SUITES.
supported-freshness-mechanisms
The supported-freshness-mechanisms parameter lists the freshness
mechanism(s) supported by the TEEP Agent. Details about the
encoding can be found in Section 9. This otherwise optional
parameter MUST be returned if err-code is
ERR_UNSUPPORTED_FRESHNESS_MECHANISMS.
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versions
The versions parameter enumerates the TEEP protocol version(s)
supported by the TEEP Agent. This otherwise optional parameter
MUST be returned if err-code is ERR_UNSUPPORTED_MSG_VERSION.
suit-reports
If present, the suit-reports parameter contains a set of SUIT
Reports as defined in Section 4 of [I-D.ietf-suit-report]. If a
token parameter was present in the Update message the Error
message is in response to, the suit-report-nonce field MUST be
present in the SUIT Report with a value matching the token
parameter in the Update message.
err-code
The err-code parameter contains one of the error codes listed
below). Only selected values are applicable to each message.
This specification defines the following initial error messages:
ERR_PERMANENT_ERROR (1)
The TEEP request contained incorrect fields or fields that are
inconsistent with other fields. For diagnosis purposes it is
RECOMMMENDED to identify the failure reason in the error message.
A TAM receiving this error might refuse to communicate further
with the TEEP Agent for some period of time until it has reason to
believe it is worth trying again, but it should take care not to
give up on communication. In contrast, ERR_TEMPORARY_ERROR is an
indication that a more agressive retry is warranted.
ERR_UNSUPPORTED_EXTENSION (2)
The TEEP Agent does not support an extension included in the
request message. For diagnosis purposes it is RECOMMMENDED to
identify the unsupported extension in the error message. A TAM
receiving this error might retry the request without using
extensions.
ERR_UNSUPPORTED_FRESHNESS_MECHANISMS (3)
The TEEP Agent does not support any freshness algorithm mechanisms
in the request message. A TAM receiving this error might retry
the request using a different set of supported freshness
mechanisms in the request message.
ERR_UNSUPPORTED_MSG_VERSION (4)
The TEEP Agent does not support the TEEP protocol version
indicated in the request message. A TAM receiving this error
might retry the request using a different TEEP protocol version.
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ERR_UNSUPPORTED_CIPHER_SUITES (5)
The TEEP Agent does not support any cipher suites indicated in the
request message. A TAM receiving this error might retry the
request using a different set of supported cipher suites in the
request message.
ERR_BAD_CERTIFICATE (6)
Processing of a certificate failed. For diagnosis purposes it is
RECOMMMENDED to include information about the failing certificate
in the error message. For example, the certificate was of an
unsupported type, or the certificate was revoked by its signer. A
TAM receiving this error might attempt to use an alternate
certificate.
ERR_CERTIFICATE_EXPIRED (9)
A certificate has expired or is not currently valid. A TAM
receiving this error might attempt to renew its certificate before
using it again.
ERR_TEMPORARY_ERROR (10)
A miscellaneous temporary error, such as a memory allocation
failure, occurred while processing the request message. A TAM
receiving this error might retry the same request at a later point
in time.
ERR_MANIFEST_PROCESSING_FAILED (17)
The TEEP Agent encountered one or more manifest processing
failures. If the suit-reports parameter is present, it contains
the failure details. A TAM receiving this error might still
attempt to install or update other components that do not depend
on the failed manifest.
New error codes should be added sparingly, not for every
implementation error. That is the intent of the err-msg field, which
can be used to provide details meaningful to humans. New error codes
should only be added if the TAM is expected to do something
behaviorally different upon receipt of the error message, rather than
just logging the event. Hence, each error code is responsible for
saying what the behavioral difference is expected to be.
5. EAT Profile
The TEEP protocol operates between a TEEP Agent and a TAM. While the
TEEP protocol does not require use of EAT, use of EAT is encouraged
and Section 4.3 explicitly defines a way to carry an Entity
Attestation Token in a QueryResponse.
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As discussed in Section 4.3.1, the content of Evidence is opaque to
the TEEP architecture, but the content of Attestation Results is not,
where Attestation Results flow between a Verifier and a TAM (as the
Relying Party). Although Attestation Results required by a TAM are
separable from the TEEP protocol per se, this section is included as
part of the requirements for building a compliant TAM that uses EATs
for Attestation Results.
Section 7 of [I-D.ietf-rats-eat] defines the requirement for Entity
Attestation Token profiles. This section defines an EAT profile for
use with TEEP.
* profile-label: The profile-label for this specification is the URI
https://datatracker.ietf.org/doc/html/draft-ietf-teep-protocol-10
(https://datatracker.ietf.org/doc/html/draft-ietf-teep-protocol-10).
(RFC-editor: upon RFC publication, replace string with
"https://www.rfc-editor.org/info/rfcXXXX" where XXXX is the RFC
number of this document.)
* Use of JSON, CBOR, or both: CBOR only.
* CBOR Map and Array Encoding: Only definite length arrays and maps.
* CBOR String Encoding: Only definite-length strings are allowed.
* CBOR Preferred Serialization: Encoders must use preferred
serialization, and decoders need not accept non-preferred
serialization.
* COSE/JOSE Protection: See Section 8.
* Detached EAT Bundle Support: DEB use is permitted.
* Verification Key Identification: COSE Key ID (kid) is used, where
the key ID is the hash of a public key (where the public key may
be used as a raw public key, or in a certificate).
* Endorsement Identification: Optional, but semantics are the same
as in Verification Key Identification.
* Freshness: See Section 9.
* Required Claims: None.
* Prohibited Claims: None.
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* Additional Claims: Optional claims are those listed in
Section 4.3.1.
* Refined Claim Definition: None.
* CBOR Tags: CBOR Tags are not used.
* Manifests and Software Evidence Claims: The sw-name claim for a
Trusted Component holds the URI of the SUIT manifest for that
component.
A TAM implementation might simply accept a TEEP Agent as trustworthy
based on a successful Attestation Result, and if not then attempt to
update the TEEP Agent and all of its dependencies. This logic is
simple but it might result in updating some components that do not
need to be updated.
An alternate TAM implementation might use any Additional Claims to
determine whether the TEEP Agent or any of its dependencies are
trustworthy, and only update the specific components that are out of
date.
6. Mapping of TEEP Message Parameters to CBOR Labels
In COSE, arrays and maps use strings, negative integers, and unsigned
integers as their keys. Integers are used for compactness of
encoding. Since the word "key" is mainly used in its other meaning,
as a cryptographic key, this specification uses the term "label" for
this usage as a map key.
This specification uses the following mapping:
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+================================+=======+
| Name | Label |
+================================+=======+
| supported-cipher-suites | 1 |
+--------------------------------+-------+
| challenge | 2 |
+--------------------------------+-------+
| versions | 3 |
+--------------------------------+-------+
| selected-cipher-suite | 5 |
+--------------------------------+-------+
| selected-version | 6 |
+--------------------------------+-------+
| attestation-payload | 7 |
+--------------------------------+-------+
| tc-list | 8 |
+--------------------------------+-------+
| ext-list | 9 |
+--------------------------------+-------+
| manifest-list | 10 |
+--------------------------------+-------+
| msg | 11 |
+--------------------------------+-------+
| err-msg | 12 |
+--------------------------------+-------+
| attestation-payload-format | 13 |
+--------------------------------+-------+
| requested-tc-list | 14 |
+--------------------------------+-------+
| unneeded-tc-list | 15 |
+--------------------------------+-------+
| component-id | 16 |
+--------------------------------+-------+
| tc-manifest-sequence-number | 17 |
+--------------------------------+-------+
| have-binary | 18 |
+--------------------------------+-------+
| suit-reports | 19 |
+--------------------------------+-------+
| token | 20 |
+--------------------------------+-------+
| supported-freshness-mechanisms | 21 |
+--------------------------------+-------+
Table 2
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7. Behavior Specification
Behavior is specified in terms of the conceptual APIs defined in
section 6.2.1 of [I-D.ietf-teep-architecture].
7.1. TAM Behavior
When the ProcessConnect API is invoked, the TAM sends a QueryRequest
message.
When the ProcessTeepMessage API is invoked, the TAM first does
validation as specified in Section 4.1.2, and drops the message if it
is not valid. Otherwise, it proceeds as follows.
If the message includes a token, it can be used to match the response
to a request previously sent by the TAM. The TAM MUST expire the
token value after receiving the first response from the device that
has a valid signature and ignore any subsequent messages that have
the same token value. The token value MUST NOT be used for other
purposes, such as a TAM to identify the devices and/or a device to
identify TAMs or Trusted Components.
7.1.1. Handling a QueryResponse Message
If a QueryResponse message is received, the TAM verifies the presence
of any parameters required based on the data-items-requested in the
QueryRequest, and also validates that the nonce in any SUIT Report
matches the token send in the QueryRequest message if a token was
present. If these requirements are not met, the TAM drops the
message. It may also do additional implementation specific actions
such as logging the results. If the requirements are met, processing
continues as follows.
If a QueryResponse message is received that contains an attestation-
payload, the TAM checks whether it contains Evidence or an Attesation
Result by inspecting the attestation-payload-format parameter. The
media type defined in Section 5 indicates an Attestation Result,
though future extensions might also indicate other Attestation Result
formats in the future. Any other unrecognized value indicates
Evidence. If it contains an Attesation Result, processing continues
as in Section 7.1.1.1.
If the QueryResponse is instead determined to contain Evidence, the
TAM passes the Evidence (via some mechanism out of scope of this
document) to an attestation Verifier (see
[I-D.ietf-rats-architecture]) to determine whether the Agent is in a
trustworthy state. Once the TAM receives an Attestation Result from
the Verifier, processing continues as in Section 7.1.1.1.
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7.1.1.1. Handling an Attestation Result
Based on the results of attestation (if any), any SUIT Reports, and
the lists of installed, requested, and unneeded Trusted Components
reported in the QueryResponse, the TAM determines, in any
implementation specific manner, which Trusted Components need to be
installed, updated, or deleted, if any. There are in typically three
cases:
1. Attestation failed. This indicates that the rest of the
information in the QueryResponse cannot necessarily be trusted,
as the TEEP Agent may not be healthy (or at least up to date).
In this case, the TAM can attempt to use TEEP to update any
Trusted Components (e.g., firmware, the TEEP Agent itself, etc.)
needed to get the TEEP Agent back into an up-to-date state that
would allow attestation to succeed.
2. Attestation succeeded (so the QueryResponse information can be
accepted as valid), but the set of Trusted Components needs to be
updated based on TAM policy changes or requests from the TEEP
Agent.
3. Attestation succeeded, and no changes are needed.
If any Trusted Components need to be installed, updated, or deleted,
the TAM sends an Update message containing SUIT Manifests with
command sequences to do the relevant installs, updates, or deletes.
It is important to note that the TEEP Agent's Update Procedure
requires resolving and installing any dependencies indicated in the
manifest, which may take some time, and the resulting Success or
Error message is generated only after completing the Update
Procedure. Hence, depending on the freshness mechanism in use, the
TAM may need to store data (e.g., a nonce) for some time.
If no Trusted Components need to be installed, updated, or deleted,
but the QueryRequest included Evidence, the TAM MAY (e.g., based on
attestation-payload-format parameters received from the TEEP Agent in
the QueryResponse) still send an Update message with no SUIT
Manifests, to pass the Attestation Result back to the TEEP Agent.
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7.1.2. Handling a Success or Error Message
If a Success or Error message is received containing one or more SUIT
Reports, the TAM also validates that the nonce in any SUIT Report
matches the token sent in the Update message, and drops the message
if it does not match. Otherwise, the TAM handles the update in any
implementation specific way, such as updating any locally cached
information about the state of the TEEP Agent, or logging the
results.
If any other Error message is received, the TAM can handle it in any
implementation specific way, but Section 4.6 provides recommendations
for such handling.
7.2. TEEP Agent Behavior
When the RequestTA API is invoked, the TEEP Agent first checks
whether the requested TA is already installed. If it is already
installed, the TEEP Agent passes no data back to the caller.
Otherwise, if the TEEP Agent chooses to initiate the process of
requesting the indicated TA, it determines (in any implementation
specific way) the TAM URI based on any TAM URI provided by the
RequestTA caller and any local configuration, and passes back the TAM
URI to connect to. It MAY also pass back a QueryResponse message if
all of the following conditions are true:
* The last QueryRequest message received from that TAM contained no
token or challenge,
* The ProcessError API was not invoked for that TAM since the last
QueryResponse message was received from it, and
* The public key or certificate of the TAM is cached and not
expired.
When the RequestPolicyCheck API is invoked, the TEEP Agent decides
whether to initiate communication with any trusted TAMs (e.g., it
might choose to do so for a given TAM unless it detects that it has
already communicated with that TAM recently). If so, it passes back
a TAM URI to connect to. If the TEEP Agent has multiple TAMs it
needs to connect with, it just passes back one, with the expectation
that RequestPolicyCheck API will be invoked to retrieve each one
successively until there are no more and it can pass back no data at
that time. Thus, once a TAM URI is returned, the TEEP Agent can
remember that it has already initiated communication with that TAM.
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When the ProcessError API is invoked, the TEEP Agent can handle it in
any implementation specific way, such as logging the error or using
the information in future choices of TAM URI.
When the ProcessTeepMessage API is invoked, the Agent first does
validation as specified in Section 4.1.2, and drops the message if it
is not valid. Otherwise, processing continues as follows based on
the type of message.
When a QueryRequest message is received, the Agent responds with a
QueryResponse message if all fields were understood, or an Error
message if any error was encountered.
When an Update message is received, the Agent attempts to update the
Trusted Components specified in the SUIT manifests by following the
Update Procedure specified in [I-D.ietf-suit-manifest], and responds
with a Success message if all SUIT manifests were successfully
installed, or an Error message if any error was encountered. It is
important to note that the Update Procedure requires resolving and
installing any dependencies indicated in the manifest, which may take
some time, and the Success or Error message is generated only after
completing the Update Procedure.
8. Cipher Suites
The TEEP protocol uses COSE for protection of TEEP messages. After a
QueryResponse is received, the selected cipher suite is used by both
the TAM and the TEEP Agent in all subsequent TEEP messages. That is,
a cipher suite is used in both directions.
To negotiate cryptographic mechanisms and algorithms, the TEEP
protocol defines the following cipher suite structure, which is used
to specify an ordered set of operations (e.g., sign) done as part of
composing a TEEP message. Although this specification only specifies
the use of signing and relies on payload encryption to protect
sensitive information, future extensions might specify support for
encryption and/or MAC operations if needed.
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$cipher-suite /= teep-cipher-suite-sign1-es256
$cipher-suite /= teep-cipher-suite-sign1-eddsa
; The following two cipher suites have only a single operation each.
; Other cipher suites may be defined to have multiple operations.
teep-cipher-suite-sign1-es256 = [ teep-operation-sign1-es256 ]
teep-cipher-suite-sign1-eddsa = [ teep-operation-sign1-eddsa ]
teep-operation-sign1-es256 = [ cose-sign1, cose-alg-es256 ]
teep-operation-sign1-eddsa = [ cose-sign1, cose-alg-eddsa ]
cose-sign1 = 18 ; CoAP Content-Format value
cose-alg-es256 = -7 ; ECDSA w/ SHA-256
cose-alg-eddsa = -8 ; EdDSA
Each operation in a given cipher suite has two elements:
* a COSE-type defined in Section 2 of [RFC8152] that identifies the
type of operation, and
* a specific cryptographic algorithm as defined in the COSE
Algorithms registry [COSE.Algorithm] to be used to perform that
operation.
A TAM MUST support both of the cipher suites defined above. A TEEP
Agent MUST support at least one of the two but can choose which one.
For example, a TEEP Agent might choose a given cipher suite if it has
hardware support for it. A TAM or TEEP Agent MAY also support any
other algorithms in the COSE Algorithms registry in addition to the
mandatory ones listed above. It MAY also support use with COSE_Sign
or other COSE types in additional cipher suites.
Any cipher suites without confidentiality protection can only be
added if the associated specification includes a discussion of
security considerations and applicability, since manifests may carry
sensitive information. For example, Section 6 of
[I-D.ietf-teep-architecture] permits implementations that terminate
transport security inside the TEE and if the transport security
provides confidentiality then additional encryption might not be
needed in the manifest for some use cases. For most use cases,
however, manifest confidentiality will be needed to protect sensitive
fields from the TAM as discussed in Section 9.8 of
[I-D.ietf-teep-architecture].
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The cipher suites defined above do not do encryption at the TEEP
layer, but permit encryption of the SUIT payload (e.g., using
[I-D.ietf-suit-firmware-encryption]). See Section 10 for more
discussion of specific payloads.
9. Freshness Mechanisms
A freshness mechanism determines how a TAM can tell whether an
attestation payload provided in a Query Response is fresh. There are
multiple ways this can be done as discussed in Section 10 of
[I-D.ietf-rats-architecture].
Each freshness mechanism is identified with an integer value, which
corresponds to an IANA registered freshness mechanism (see the IANA
Considerations section of
[I-D.ietf-rats-reference-interaction-models]). This document uses
the following freshness mechanisms:
FRESHNESS_NONCE = 0
FRESHNESS_TIMESTAMP = 1
FRESHNESS_EPOCH_ID = 2
$freshness-mechanism /= FRESHNESS_NONCE
$freshness-mechanism /= FRESHNESS_TIMESTAMP
$freshness-mechanism /= FRESHNESS_EPOCH_ID
In the Nonce mechanism, the attestation payload MUST include a nonce
provided in the QueryRequest challenge. In other mechanisms, a
timestamp or epoch ID determined via mechanisms outside the TEEP
protocol is used, and the challenge is only needed in the
QueryRequest message if a challenge is needed in generating the
attestation payload for reasons other than freshness.
If a TAM supports multiple freshness mechanisms that require
different challenge formats, the QueryRequest message can currently
only send one such challenge. This situation is expected to be rare,
but should it occur, the TAM can choose to prioritize one of them and
exclude the other from the supported-freshness-mechanisms in the
QueryRequest, and resend the QueryRequest with the other mechanism if
an ERR_UNSUPPORTED_FRESHNESS_MECHANISMS Error is received that
indicates the TEEP Agent supports the other mechanism.
10. Security Considerations
This section summarizes the security considerations discussed in this
specification:
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Cryptographic Algorithms
TEEP protocol messages exchanged between the TAM and the TEEP
Agent are protected using COSE. This specification relies on the
cryptographic algorithms provided by COSE. Public key based
authentication is used by the TEEP Agent to authenticate the TAM
and vice versa.
Attestation
A TAM relies on signed Attestation Results provided by a Verifier,
either obtained directly using a mechanism outside the TEEP
protocol (by using some mechanism to pass Evidence obtained in the
attestation payload of a QueryResponse, and getting back the
Attestation Results), or indirectly via the TEEP Agent forwarding
the Attestation Results in the attestation payload of a
QueryResponse. See the security considerations of the specific
mechanism in use (e.g., EAT) for more discussion. Depending on
the properties of the attestation mechanism, it is possible to
uniquely identify a device based on information in the attestation
payload or in the certificate used to sign the attestation
payload. This uniqueness may raise privacy concerns. To lower
the privacy implications the TEEP Agent MUST present its
attestation payload only to an authenticated and authorized TAM
and when using EATS, it SHOULD use encryption as discussed in
[I-D.ietf-rats-eat], since confidentiality is not provided by the
TEEP protocol itself and the transport protocol under the TEEP
protocol might be implemented outside of any TEE. If any
mechanism other than EATs is used, it is up to that mechanism to
specify how privacy is provided.
Trusted Component Binaries
Each Trusted Component binary is signed by a Trusted Component
Signer. It is the responsibility of the TAM to relay only
verified Trusted Components from authorized Trusted Component
Signers. Delivery of a Trusted Component to the TEEP Agent is
then the responsibility of the TAM, using the security mechanisms
provided by the TEEP protocol. To protect the Trusted Component
binary, the SUIT manifest format is used and it offers a variety
of security features, including digitial signatures and can
support symmetric encryption if a SUIT mechanism such as
[I-D.ietf-suit-firmware-encryption] is used.
Personalization Data
A Trusted Component Signer or TAM can supply personalization data
along with a Trusted Component. This data is also protected by a
SUIT manifest. Personalization data signed and encrypted (e.g.,
via [I-D.ietf-suit-firmware-encryption]) by a Trusted Component
Signer other than the TAM is opaque to the TAM.
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TEEP Broker
As discussed in section 6 of [I-D.ietf-teep-architecture], the
TEEP protocol typically relies on a TEEP Broker to relay messages
between the TAM and the TEEP Agent. When the TEEP Broker is
compromised it can drop messages, delay the delivery of messages,
and replay messages but it cannot modify those messages. (A
replay would be, however, detected by the TEEP Agent.) A
compromised TEEP Broker could reorder messages in an attempt to
install an old version of a Trusted Component. Information in the
manifest ensures that TEEP Agents are protected against such
downgrade attacks based on features offered by the manifest
itself.
Trusted Component Signer Compromise
A TAM is responsible for vetting a Trusted Component and before
distributing them to TEEP Agents.
It is RECOMMENDED to provide a way to update the trust anchor
store used by the TEE, for example using a firmware update
mechanism. Thus, if a Trusted Component Signer is later
compromised, the TAM can update the trust anchor store used by the
TEE, for example using a firmware update mechanism.
CA Compromise
The CA issuing certificates to a TEE or a Trusted Component Signer
might get compromised. It is RECOMMENDED to provide a way to
update the trust anchor store used by the TEE, for example using a
firmware update mechanism. If the CA issuing certificates to
devices gets compromised then these devices might be rejected by a
TAM, if revocation is available to the TAM.
TAM Certificate Expiry
The integrity and the accuracy of the clock within the TEE
determines the ability to determine an expired TAM certificate, if
certificates are used.
Compromised Time Source
As discussed above, certificate validity checks rely on comparing
validity dates to the current time, which relies on having a
trusted source of time, such as [RFC8915]. A compromised time
source could thus be used to subvert such validity checks.
11. IANA Considerations
11.1. Media Type Registration
IANA is requested to assign a media type for application/teep+cbor.
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Type name: application
Subtype name: teep+cbor
Required parameters: none
Optional parameters: none
Encoding considerations: Same as encoding considerations of
application/cbor.
Security considerations: See Security Considerations Section of this
document.
Interoperability considerations: Same as interoperability
considerations of application/cbor as specified in [RFC7049].
Published specification: This document.
Applications that use this media type: TEEP protocol implementations
Fragment identifier considerations: N/A
Additional information: Deprecated alias names for this type: N/A
Magic number(s): N/A
File extension(s): N/A
Macintosh file type code(s): N/A
Person to contact for further information: teep@ietf.org
Intended usage: COMMON
Restrictions on usage: none
Author: See the "Authors' Addresses" section of this document
Change controller: IETF
12. References
12.1. Normative References
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[COSE.Algorithm]
IANA, "COSE Algorithms", n.d.,
<https://www.iana.org/assignments/cose/
cose.xhtml#algorithms>.
[I-D.ietf-rats-architecture]
Birkholz, H., Thaler, D., Richardson, M., Smith, N., and
W. Pan, "Remote Attestation Procedures Architecture", Work
in Progress, Internet-Draft, draft-ietf-rats-architecture-
19, 24 July 2022, <https://www.ietf.org/archive/id/draft-
ietf-rats-architecture-19.txt>.
[I-D.ietf-rats-eat]
Lundblade, L., Mandyam, G., and J. O'Donoghue, "The Entity
Attestation Token (EAT)", Work in Progress, Internet-
Draft, draft-ietf-rats-eat-14, 10 July 2022,
<https://www.ietf.org/archive/id/draft-ietf-rats-eat-
14.txt>.
[I-D.ietf-rats-reference-interaction-models]
Birkholz, H., Eckel, M., Pan, W., and E. Voit, "Reference
Interaction Models for Remote Attestation Procedures",
Work in Progress, Internet-Draft, draft-ietf-rats-
reference-interaction-models-05, 26 January 2022,
<https://www.ietf.org/archive/id/draft-ietf-rats-
reference-interaction-models-05.txt>.
[I-D.ietf-suit-manifest]
Moran, B., Tschofenig, H., Birkholz, H., and K. Zandberg,
"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-18, 11 July 2022,
<https://www.ietf.org/archive/id/draft-ietf-suit-manifest-
18.txt>.
[I-D.ietf-suit-report]
Moran, B. and H. Birkholz, "Secure Reporting of Update
Status", Work in Progress, Internet-Draft, draft-ietf-
suit-report-02, 11 July 2022,
<https://www.ietf.org/archive/id/draft-ietf-suit-report-
02.txt>.
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[I-D.ietf-suit-trust-domains]
Moran, B., "SUIT Manifest Extensions for Multiple Trust
Domains", Work in Progress, Internet-Draft, draft-ietf-
suit-trust-domains-00, 7 March 2022,
<https://www.ietf.org/archive/id/draft-ietf-suit-trust-
domains-00.txt>.
[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>.
[RFC3629] Yergeau, F., "UTF-8, a transformation format of ISO
10646", STD 63, RFC 3629, DOI 10.17487/RFC3629, November
2003, <https://www.rfc-editor.org/info/rfc3629>.
[RFC5198] Klensin, J. and M. Padlipsky, "Unicode Format for Network
Interchange", RFC 5198, DOI 10.17487/RFC5198, March 2008,
<https://www.rfc-editor.org/info/rfc5198>.
[RFC5280] Cooper, D., Santesson, S., Farrell, S., Boeyen, S.,
Housley, R., and W. Polk, "Internet X.509 Public Key
Infrastructure Certificate and Certificate Revocation List
(CRL) Profile", RFC 5280, DOI 10.17487/RFC5280, May 2008,
<https://www.rfc-editor.org/info/rfc5280>.
[RFC7049] Bormann, C. and P. Hoffman, "Concise Binary Object
Representation (CBOR)", RFC 7049, DOI 10.17487/RFC7049,
October 2013, <https://www.rfc-editor.org/info/rfc7049>.
[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>.
12.2. Informative References
[I-D.ietf-suit-firmware-encryption]
Tschofenig, H., Housley, R., and B. Moran, "Firmware
Encryption with SUIT Manifests", Work in Progress,
Internet-Draft, draft-ietf-suit-firmware-encryption-06, 11
July 2022, <https://www.ietf.org/archive/id/draft-ietf-
suit-firmware-encryption-06.txt>.
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[I-D.ietf-teep-architecture]
Pei, M., Tschofenig, H., Thaler, D., and D. Wheeler,
"Trusted Execution Environment Provisioning (TEEP)
Architecture", Work in Progress, Internet-Draft, draft-
ietf-teep-architecture-18, 11 July 2022,
<https://www.ietf.org/archive/id/draft-ietf-teep-
architecture-18.txt>.
[I-D.lundblade-rats-eat-media-type]
Lundblade, L., Birkholz, H., and T. Fossati, "EAT Media
Types", Work in Progress, Internet-Draft, draft-lundblade-
rats-eat-media-type-00, 26 May 2022,
<https://www.ietf.org/archive/id/draft-lundblade-rats-eat-
media-type-00.txt>.
[RFC8126] Cotton, M., Leiba, B., and T. Narten, "Guidelines for
Writing an IANA Considerations Section in RFCs", BCP 26,
RFC 8126, DOI 10.17487/RFC8126, June 2017,
<https://www.rfc-editor.org/info/rfc8126>.
[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/info/rfc8610>.
[RFC8915] Franke, D., Sibold, D., Teichel, K., Dansarie, M., and R.
Sundblad, "Network Time Security for the Network Time
Protocol", RFC 8915, DOI 10.17487/RFC8915, September 2020,
<https://www.rfc-editor.org/info/rfc8915>.
A. Contributors
We would like to thank Brian Witten (Symantec), Tyler Kim (Solacia),
Nick Cook (Arm), and Minho Yoo (IoTrust) for their contributions to
the Open Trust Protocol (OTrP), which influenced the design of this
specification.
B. Acknowledgements
We would like to thank Eve Schooler for the suggestion of the
protocol name.
We would like to thank Kohei Isobe (TRASIO/SECOM), Ken Takayama
(SECOM) Kuniyasu Suzaki (TRASIO/AIST), Tsukasa Oi (TRASIO), and
Yuichi Takita (SECOM) for their valuable implementation feedback.
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We would also like to thank Carsten Bormann and Henk Birkholz for
their help with the CDDL.
C. Complete CDDL
Valid TEEP messages MUST adhere to the following CDDL data
definitions, except that "SUIT_Envelope" and
"SUIT_Component_Identifier" are specified in
[I-D.ietf-suit-manifest].
teep-message = $teep-message-type .within teep-message-framework
teep-message-framework = [
type: uint (0..23) / $teep-type-extension,
options: { * teep-option },
* uint; further integers, e.g., for data-item-requested
]
teep-option = (uint => any)
; messages defined below:
$teep-message-type /= query-request
$teep-message-type /= query-response
$teep-message-type /= update
$teep-message-type /= teep-success
$teep-message-type /= teep-error
; message type numbers, uint (0..23)
TEEP-TYPE-query-request = 1
TEEP-TYPE-query-response = 2
TEEP-TYPE-update = 3
TEEP-TYPE-teep-success = 5
TEEP-TYPE-teep-error = 6
version = uint .size 4
ext-info = uint .size 4
; data items as bitmaps
data-item-requested = $data-item-requested
attestation = 1
$data-item-requested /= attestation
trusted-components = 2
$data-item-requested /= trusted-components
extensions = 4
$data-item-requested /= extensions
query-request = [
type: TEEP-TYPE-query-request,
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options: {
? token => bstr .size (8..64),
? supported-freshness-mechanisms => [ + freshness-mechanism ],
? challenge => bstr .size (8..512),
? versions => [ + version ],
* $$query-request-extensions
* $$teep-option-extensions
},
supported-cipher-suites: [ + $cipher-suite ],
data-item-requested: data-item-requested
]
;MANDATORY for TAM and TEEP Agent to support the following COSE
;operations, and OPTIONAL to support additional ones such as
;COSE_Sign_Tagged, COSE_Encrypt0_Tagged, etc.
COSE_Sign1_Tagged = 18
;MANDATORY for TAM to support the following, and OPTIONAL to implement
;any additional algorithms from the IANA COSE Algorithms registry.
cose-alg-eddsa = -8 ; EdDSA
cose-alg-es256 = -7 ; ECDSA w/ SHA-256
;MANDATORY for TAM to support the following cipher-suites, and OPTIONAL
;to support any additional ones that use COSE_Sign_Tagged, or other
;signing, encryption, or MAC algorithms.
teep-operation-sign1-eddsa = [ COSE_Sign1_Tagged, cose-alg-eddsa ]
teep-operation-sign1-es256 = [ COSE_Sign1_Tagged, cose-alg-es256 ]
teep-cipher-suite-sign1-eddsa = [ teep-operation-sign1-eddsa ]
teep-cipher-suite-sign1-es256 = [ teep-operation-sign1-es256 ]
$cipher-suite /= teep-cipher-suite-sign1-eddsa
$cipher-suite /= teep-cipher-suite-sign1-es256
; freshness-mechanisms
FRESHNESS_NONCE = 0
FRESHNESS_TIMESTAMP = 1
FRESHNESS_EPOCH_ID = 2
$freshness-mechanism /= FRESHNESS_NONCE
$freshness-mechanism /= FRESHNESS_TIMESTAMP
$freshness-mechanism /= FRESHNESS_EPOCH_ID
query-response = [
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type: TEEP-TYPE-query-response,
options: {
? token => bstr .size (8..64),
? selected-cipher-suite => cipher-suite,
? selected-version => version,
? attestation-payload-format => text,
? attestation-payload => bstr,
? suit-reports => [ + SUIT_Report ],
? tc-list => [ + system-property-claims ],
? requested-tc-list => [ + requested-tc-info ],
? unneeded-tc-list => [ + SUIT_Component_Identifier ],
? ext-list => [ + ext-info ],
* $$query-response-extensions,
* $$teep-option-extensions
}
]
requested-tc-info = {
component-id => SUIT_Component_Identifier,
? tc-manifest-sequence-number => uint .size 8
? have-binary => bool
}
update = [
type: TEEP-TYPE-update,
options: {
? token => bstr .size (8..64),
? manifest-list => [ + bstr .cbor SUIT_Envelope ],
* $$update-extensions,
* $$teep-option-extensions
}
]
teep-success = [
type: TEEP-TYPE-teep-success,
options: {
? token => bstr .size (8..64),
? msg => text .size (1..128),
? suit-reports => [ + SUIT_Report ],
* $$teep-success-extensions,
* $$teep-option-extensions
}
]
teep-error = [
type: TEEP-TYPE-teep-error,
options: {
? token => bstr .size (8..64),
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? err-msg => text .size (1..128),
? supported-cipher-suites => [ + $cipher-suite ],
? supported-freshness-mechanisms => [ + freshness-mechanism ],
? versions => [ + version ],
? suit-reports => [ + SUIT_Report ],
* $$teep-error-extensions,
* $$teep-option-extensions
},
err-code: uint (0..23)
]
; The err-code parameter, uint (0..23)
ERR_PERMANENT_ERROR = 1
ERR_UNSUPPORTED_EXTENSION = 2
ERR_UNSUPPORTED_FRESHNESS_MECHANISMS = 3
ERR_UNSUPPORTED_MSG_VERSION = 4
ERR_UNSUPPORTED_CIPHER_SUITES = 5
ERR_BAD_CERTIFICATE = 6
ERR_CERTIFICATE_EXPIRED = 9
ERR_TEMPORARY_ERROR = 10
ERR_MANIFEST_PROCESSING_FAILED = 17
; labels of mapkey for teep message parameters, uint (0..23)
supported-cipher-suites = 1
challenge = 2
versions = 3
selected-cipher-suite = 5
selected-version = 6
attestation-payload = 7
tc-list = 8
ext-list = 9
manifest-list = 10
msg = 11
err-msg = 12
attestation-payload-format = 13
requested-tc-list = 14
unneeded-tc-list = 15
component-id = 16
tc-manifest-sequence-number = 17
have-binary = 18
suit-reports = 19
token = 20
supported-freshness-mechanisms = 21
D. Examples of Diagnostic Notation and Binary Representation
This section includes some examples with the following assumptions:
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* The device will have two TCs with the following SUIT Component
Identifiers:
- [ 0x000102030405060708090a0b0c0d0e0f ]
- [ 0x100102030405060708090a0b0c0d0e0f ]
* SUIT manifest-list is set empty only for example purposes (see
Appendix E for actual manifest examples)
D.1. QueryRequest Message
D.1.1. CBOR Diagnostic Notation
/ query-request = /
[
/ type: / 1 / TEEP-TYPE-query-request /,
/ options: /
{
/ token / 20 : h'A0A1A2A3A4A5A6A7A8A9AAABACADAEAF',
/ versions / 3 : [ 0 ] / 0 is current TEEP Protocol /
},
/ supported-cipher-suites: / [ [ [ 18, -7 ] ], / Sign1 using ES256 /
[ [ 18, -8 ] ] / Sign1 using EdDSA /
],
/ data-item-requested: / 3 / attestation | trusted-components /
]
D.1.2. CBOR Binary Representation
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85 # array(5)
01 # unsigned(1) / TEEP-TYPE-query-request /
81 # array(1)
83 # array(3)
26 # negative(6) / -7 = cose-alg-es256 /
F6 # primitive(22) / null /
F6 # primitive(22) / null /
A2 # map(2)
14 # unsigned(20) / token: /
50 # bytes(16)
A0A1A2A3A4A5A6A7A8A9AAABACADAEAF
03 # unsigned(3) / versions: /
81 # array(1) / [ 0 ] /
00 # unsigned(0)
82 # array(2) /* supported-cipher-suites /
81 # array(1)
82 # array(2)
12 # unsigned(18) / cose-sign1 /
26 # negative(6) / -7 = cose-alg-es256 /
81 # array(1)
82 # array(2)
12 # unsigned(18) / cose-sign1 /
27 # negative(7) / -8 = cose-alg-eddsa /
03 # unsigned(3) / attestation | trusted-components /
D.2. Entity Attestation Token
This is shown below in CBOR diagnostic form. Only the payload signed
by COSE is shown.
D.2.1. CBOR Diagnostic Notation
/ eat-claim-set = /
{
/ issuer / 1: "joe",
/ timestamp (iat) / 6: 1(1526542894)
/ nonce / 10: h'948f8860d13a463e8e',
/ secure-boot / 15: true,
/ debug-status / 16: 3, / disabled-permanently /
/ security-level / 14: 3, / secure-restricted /
/ device-identifier / <TBD>: h'e99600dd921649798b013e9752dcf0c5',
/ vendor-identifier / <TBD>: h'2b03879b33434a7ca682b8af84c19fd4',
/ class-identifier / <TBD>: h'9714a5796bd245a3a4ab4f977cb8487f',
/ chip-version / 26: [ "MyTEE", 1 ],
/ component-identifier / <TBD>: h'60822887d35e43d5b603d18bcaa3f08d',
/ version / <TBD>: "v0.1"
}
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D.3. QueryResponse Message
D.3.1. CBOR Diagnostic Notation
/ query-response = /
[
/ type: / 2 / TEEP-TYPE-query-response /,
/ options: /
{
/ token / 20 : h'A0A1A2A3A4A5A6A7A8A9AAABACADAEAF',
/ selected-cipher-suite / 5 : [ [ 18, -7 ] ] / only use ES256 /,
/ selected-version / 6 : 0,
/ attestation-payload / 7 : h'' / empty only for example purpose /,
/ tc-list / 8 : [
{
/ component-id / 16 : [ h'0102030405060708100A0B0C0D0E0F' ]
},
{
/ component-id / 16 : [ h'1102030405060708090A0B0C0D0E0F' ]
}
]
}
]
D.3.2. CBOR Binary Representation
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82 # array(2)
02 # unsigned(2) / TEEP-TYPE-query-response /
A5 # map(5)
14 # unsigned(20) / token: /
50 # bytes(16)
A0A1A2A3A4A5A6A7A8A9AAABACADAEAF
05 # unsigned(5) / selected-cipher-suite: /
81 # array(1)
82 # array(2)
12 # unsigned(18) / cose-sign1 /
26 # negative(6) / -7 = cose-alg-es256 /
06 # unsigned(6) / selected-version: /
00 # unsigned(0)
07 # unsigned(7) / attestation-payload: /
40 # bytes(0)
# ""
08 # unsigned(8) / tc-list: /
82 # array(2)
A1 # map(1)
10 # unsigned(16) / component-id: /
81 # array(1)
4F # bytes(15)
0102030405060708090A0B0C0D0E0F
A1 # map(1)
10 # unsigned(16) / component-id: /
81 # array(1)
4F # bytes(15)
1102030405060708090A0B0C0D0E0F
D.4. Update Message
D.4.1. CBOR Diagnostic Notation
/ update = /
[
/ type: / 3 / TEEP-TYPE-update /,
/ options: /
{
/ token / 20 : h'A0A1A2A3A4A5A6A7A8A9AAABACADAEAF',
/ manifest-list / 10 : [ ] / array of SUIT_Envelope /
/ empty, example purpose only /
}
]
D.4.2. CBOR Binary Representation
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82 # array(2)
03 # unsigned(3) / TEEP-TYPE-update /
A2 # map(2)
14 # unsigned(20) / token: /
50 # bytes(16)
A0A1A2A3A4A5A6A7A8A9AAABACADAEAF
0A # unsigned(10) / manifest-list: /
80 # array(0) / [] /
D.5. Success Message
D.5.1. CBOR Diagnostic Notation
/ teep-success = /
[
/ type: / 5 / TEEP-TYPE-teep-success /,
/ options: /
{
/ token / 20 : h'A0A1A2A3A4A5A6A7A8A9AAABACADAEAF'
}
]
D.5.2. CBOR Binary Representation
82 # array(2)
05 # unsigned(5) / TEEP-TYPE-teep-success /
A1 # map(1)
14 # unsigned(20) / token: /
50 # bytes(16)
A0A1A2A3A4A5A6A7A8A9AAABACADAEAF
D.6. Error Message
D.6.1. CBOR Diagnostic Notation
/ teep-error = /
[
/ type: / 6 / TEEP-TYPE-teep-error /,
/ options: /
{
/ token / 20 : h'A0A1A2A3A4A5A6A7A8A9AAABACADAEAF',
/ err-msg / 12 : "disk-full"
},
/ err-code: / 17 / ERR_MANIFEST_PROCESSING_FAILED /
]
D.6.2. CBOR binary Representation
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83 # array(3)
06 # unsigned(6) / TEEP-TYPE-teep-error /
A2 # map(2)
14 # unsigned(20) / token: /
50 # bytes(16)
A0A1A2A3A4A5A6A7A8A9AAABACADAEAF
0C # unsigned(12) / err-msg: /
69 # text(9)
6469736B2D66756C6C # "disk-full"
11 # unsigned(17) / ERR_MANIFEST_PROCESSING_FAILED /
E. Examples of SUIT Manifests
This section shows some examples of SUIT manifests described in
Section 4.4.
The examples are signed using the following ECDSA secp256r1 key with
SHA256 as the digest function.
COSE_Sign1 Cryptographic 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-----
Example 1: SUIT Manifest pointing to URI of the Trusted Component Binary
CBOR Diagnostic Notation of SUIT Manifest
/ SUIT_Envelope_Tagged / 107( {
/ suit-authentication-wrapper / 2: << [
<< [
/ suit-digest-algorithm-id: / -16 / suit-cose-alg-sha256 /,
/ suit-digest-bytes: / h'DB601ADE73092B58532CA03FBB663DE49532435336F1558B49BB622726A2FEDD'
] >>,
<< / COSE_Sign1_Tagged / 18( [
/ protected: / << {
/ algorithm-id / 1: -7 / ES256 /
} >>,
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/ unprotected: / {},
/ payload: / null,
/ signature: / h'5B2D535A2B6D5E3C585C1074F414DA9E10BD285C99A33916DADE3ED38812504817AC48B62B8E984EC622785BD1C411888BE531B1B594507816B201F6F28579A4'
] ) >>
] >>,
/ suit-manifest / 3: << {
/ suit-manifest-version / 1: 1,
/ suit-manifest-sequence-number / 2: 3,
/ suit-common / 3: << {
/ suit-components / 2: [
[
h'544545502D446576696365', / "TEEP-Device" /
h'5365637572654653', / "SecureFS" /
h'8D82573A926D4754935332DC29997F74', / tc-uuid /
h'7461' / "ta" /
]
],
/ suit-common-sequence / 4: << [
/ suit-directive-override-parameters / 20, {
/ suit-parameter-vendor-identifier / 1: h'C0DDD5F15243566087DB4F5B0AA26C2F',
/ suit-parameter-class-identifier / 2: h'DB42F7093D8C55BAA8C5265FC5820F4E',
/ suit-parameter-image-digest / 3: << [
/ suit-digest-algorithm-id: / -16 / suit-cose-alg-sha256 /,
/ suit-digest-bytes: / h'8CF71AC86AF31BE184EC7A05A411A8C3A14FD9B77A30D046397481469468ECE8'
] >>,
/ suit-parameter-image-size / 14: 20
},
/ suit-condition-vendor-identifier / 1, 15,
/ suit-condition-class-identifier / 2, 15
] >>
} >>,
/ suit-install / 9: << [
/ suit-directive-override-parameters / 20, {
/ suit-parameter-uri / 21: "https://example.org/8d82573a-926d-4754-9353-32dc29997f74.ta"
},
/ suit-directive-fetch / 21, 15,
/ suit-condition-image-match / 3, 15
] >>
} >>
} )
CBOR Binary Representation
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D8 6B # tag(107) / SUIT_Envelope_Tagged /
A2 # map(2)
02 # unsigned(2) / suit-authentication-wrapper /
58 73 # bytes(115)
82 # array(2)
58 24 # bytes(36)
82 # array(2)
2F # negative(15) / -16 = suit-cose-alg-sha256 /
58 20 # bytes(32)
DB601ADE73092B58532CA03FBB663DE49532435336F1558B49BB622726A2FEDD
58 4A # bytes(74)
D2 # tag(18) / COSE_Sign1_Tagged /
84 # array(4)
43 # bytes(3)
A1 # map(1)
01 # unsigned(1) / algorithm-id /
26 # negative(6) / -7 = ES256 /
A0 # map(0)
F6 # primitive(22) / null /
58 40 # bytes(64)
5B2D535A2B6D5E3C585C1074F414DA9E10BD285C99A33916DADE3ED38812504817AC48B62B8E984EC622785BD1C411888BE531B1B594507816B201F6F28579A4
03 # unsigned(3) / suit-manifest: /
58 D4 # bytes(212)
A4 # map(4)
01 # unsigned(1) / suit-manifest-version: /
01 # unsigned(1)
02 # unsigned(2) / suit-manifest-sequence-number: /
03 # unsigned(3)
03 # unsigned(3) / suit-common: /
58 84 # bytes(132)
A2 # map(2)
02 # unsigned(2) / suit-components: /
81 # array(1)
84 # array(4)
4B # bytes(11)
544545502D446576696365 # "TEEP-Device"
48 # bytes(8)
5365637572654653 # "SecureFS"
50 # bytes(16)
8D82573A926D4754935332DC29997F74 # tc-uuid
42 # bytes(2)
7461 # "ta"
04 # unsigned(4) / suit-common-sequence: /
58 54 # bytes(84)
86 # array(6)
14 # unsigned(20) / suit-directive-override-parameters: /
A4 # map(4)
01 # unsigned(1) / suit-parameter-vendor-identifier: /
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50 # bytes(16)
C0DDD5F15243566087DB4F5B0AA26C2F
02 # unsigned(2) / suit-parameter-class-identifier: /
50 # bytes(16)
DB42F7093D8C55BAA8C5265FC5820F4E
03 # unsigned(3) / suit-parameter-image-digest: /
58 24 # bytes(36)
82 # array(2)
2F # negative(15) / -16 = suit-cose-alg-sha256 /
58 20 # bytes(32)
8CF71AC86AF31BE184EC7A05A411A8C3A14FD9B77A30D046397481469468ECE8
0E # unsigned(14) / suit-parameter-image-size: /
14 # unsigned(20)
01 # unsigned(1) / suit-condition-vendor-identifier: /
0F # unsigned(15)
02 # unsigned(2) / suit-condition-class-identifier: /
0F # unsigned(15)
09 # unsigned(9) / suit-install: /
58 45 # bytes(69)
86 # array(6)
14 # unsigned(20) / suit-directive-override-parameters: /
A1 # map(1)
15 # unsigned(21) / suit-parameter-uri: /
78 3B # text(59)
68747470733A2F2F6578616D706C652E6F72672F38643832353733612D393236642D343735342D393335332D3332646332393939376637342E7461 # "https://example.org/8d82573a-926d-4754-9353-32dc29997f74.ta"
15 # unsigned(21) / suit-directive-fetch: /
0F # unsigned(15)
03 # unsigned(3) / suit-condition-image-match: /
0F # unsigned(15)
CBOR Binary in Hex
D86BA2025873825824822F5820DB601ADE73092B58532CA03FBB663DE495
32435336F1558B49BB622726A2FEDD584AD28443A10126A0F658405B2D53
5A2B6D5E3C585C1074F414DA9E10BD285C99A33916DADE3ED38812504817
AC48B62B8E984EC622785BD1C411888BE531B1B594507816B201F6F28579
A40358D4A401010203035884A20281844B544545502D4465766963654853
65637572654653508D82573A926D4754935332DC29997F74427461045854
8614A40150C0DDD5F15243566087DB4F5B0AA26C2F0250DB42F7093D8C55
BAA8C5265FC5820F4E035824822F58208CF71AC86AF31BE184EC7A05A411
A8C3A14FD9B77A30D046397481469468ECE80E14010F020F0958458614A1
15783B68747470733A2F2F6578616D706C652E6F72672F38643832353733
612D393236642D343735342D393335332D3332646332393939376637342E
7461150F030F
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Example 2: SUIT Manifest including the Trusted Component Binary
CBOR Diagnostic Notation of SUIT Manifest
/ SUIT_Envelope_Tagged / 107( {
/ suit-authentication-wrapper / 2: << [
<< [
/ suit-digest-algorithm-id: / -16 / suit-cose-alg-sha256 /,
/ suit-digest-bytes: / h'14A98BE957DE38FAE37376EA491FD6CAD9BFBD3C90051C8F5B017D7A496C3B05'
] >>,
<< / COSE_Sign1_Tagged / 18( [
/ protected: / << {
/ algorithm-id / 1: -7 / ES256 /
} >>,
/ unprotected: / {},
/ payload: / null,
/ signature: / h'4093B323953785981EB607C8BA61B21E5C4F85726A2AF48C1CB05BD4401B1B1565070728FDA38E6496D631E1D23F966CFF7805EDE721D48507D9192993DA8722'
] ) >>
] >>,
/ suit-integrated-payload / "#tc": h'48656C6C6F2C2053656375726520576F726C6421', / "Hello, Secure World!" /
/ suit-manifest / 3: << {
/ suit-manifest-version / 1: 1,
/ suit-manifest-sequence-number / 2: 3,
/ suit-common / 3: << {
/ suit-components / 2: [
[
h'544545502D446576696365', / "TEEP-Device" /
h'5365637572654653', / "SecureFS" /
h'8D82573A926D4754935332DC29997F74', / tc-uuid /
h'7461' / "ta" /
]
],
/ suit-common-sequence / 4: << [
/ suit-directive-override-parameters / 20, {
/ suit-parameter-vendor-identifier / 1: h'C0DDD5F15243566087DB4F5B0AA26C2F',
/ suit-parameter-class-identifier / 2: h'DB42F7093D8C55BAA8C5265FC5820F4E',
/ suit-parameter-image-digest / 3: << [
/ suit-digest-algorithm-id: / -16 / suit-cose-alg-sha256 /,
/ suit-digest-bytes: / h'8CF71AC86AF31BE184EC7A05A411A8C3A14FD9B77A30D046397481469468ECE8'
] >>,
/ suit-parameter-image-size / 14: 20
},
/ suit-condition-vendor-identifier / 1, 15,
/ suit-condition-class-identifier / 2, 15
] >>
} >>,
/ suit-install / 9: << [
/ suit-directive-override-parameters / 20, {
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/ suit-parameter-uri / 21: "#tc"
},
/ suit-directive-fetch / 21, 15,
/ suit-condition-image-match / 3, 15
] >>
} >>
} )
CBOR Binary Representation
D8 6B # tag(107) / SUIT_Envelope_Tagged /
A3 # map(3)
02 # unsigned(2) / suit-authentication-wrapper /
58 73 # bytes(115)
82 # array(2)
58 24 # bytes(36)
82 # array(2)
2F # negative(15) / -16 = suit-cose-alg-sha256 /
58 20 # bytes(32)
14A98BE957DE38FAE37376EA491FD6CAD9BFBD3C90051C8F5B017D7A496C3B05
58 4A # bytes(74)
D2 # tag(18) / COSE_Sign1_Tagged /
84 # array(4)
43 # bytes(3)
A1 # map(1)
01 # unsigned(1) / algorithm-id /
26 # negative(6) / -7 = ES256 /
A0 # map(0)
F6 # primitive(22) / null /
58 40 # bytes(64)
4093B323953785981EB607C8BA61B21E5C4F85726A2AF48C1CB05BD4401B1B1565070728FDA38E6496D631E1D23F966CFF7805EDE721D48507D9192993DA8722
63 # text(3) / suit-integrated-payload /
237463 # "#tc"
54 # bytes(20)
48656C6C6F2C2053656375726520576F726C6421 # "Hello, Secure World!"
03 # unsigned(3) / suit-manifest: /
58 9A # bytes(154)
A4 # map(4)
01 # unsigned(1) / suit-manifest-version: /
01 # unsigned(1)
02 # unsigned(2) / suit-manifest-sequence-number: /
03 # unsigned(3)
03 # unsigned(3) / suit-common: /
58 84 # bytes(132)
A2 # map(2)
02 # unsigned(2) / suit-components: /
81 # array(1)
84 # array(4)
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4B # bytes(11)
544545502D446576696365 # "TEEP-Device"
48 # bytes(8)
5365637572654653 # "SecureFS"
50 # bytes(16)
8D82573A926D4754935332DC29997F74 # tc-uuid
42 # bytes(2)
7461 # "ta"
04 # unsigned(4) / suit-common-sequence: /
58 54 # bytes(84)
86 # array(6)
14 # unsigned(20) / suit-directive-override-parameters: /
A4 # map(4)
01 # unsigned(1) / suit-parameter-vendor-identifier: /
50 # bytes(16)
C0DDD5F15243566087DB4F5B0AA26C2F
02 # unsigned(2) / suit-parameter-class-identifier: /
50 # bytes(16)
DB42F7093D8C55BAA8C5265FC5820F4E
03 # unsigned(3) / suit-parameter-image-digest: /
58 24 # bytes(36)
82 # array(2)
2F # negative(15) / -16 = suit-cose-alg-sha256 /
58 20 # bytes(32)
8CF71AC86AF31BE184EC7A05A411A8C3A14FD9B77A30D046397481469468ECE8
0E # unsigned(14) / suit-parameter-image-size: /
14 # unsigned(20)
01 # unsigned(1) / suit-condition-vendor-identifier: /
0F # unsigned(15)
02 # unsigned(2) / suit-condition-class-identifier: /
0F # unsigned(15)
09 # unsigned(9) / suit-install: /
4C # bytes(12)
86 # array(6)
14 # unsigned(20) / suit-directive-override-parameters: /
A1 # map(1)
15 # unsigned(21) / suit-parameter-uri: /
63 # text(3)
237463 # "#tc"
15 # unsigned(21) / suit-directive-fetch: /
0F # unsigned(15)
03 # unsigned(3) / suit-condition-image-match: /
0F # unsigned(15)
CBOR Binary in Hex
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D86BA3025873825824822F582014A98BE957DE38FAE37376EA491FD6CAD9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Example 3: Supplying Personalization Data for Trusted Component Binary
CBOR Diagnostic Notation of SUIT Manifest
/ SUIT_Envelope_Tagged / 107( {
/ suit-authentication-wrapper / 2: << [
<< [
/ suit-digest-algorithm-id: / -16 / suit-cose-alg-sha256 /,
/ suit-digest-bytes: / h'CE596D785169B72712560B3A246AA98F814498EA3625EEBB72CED9AF273E7FFD'
] >>,
<< / COSE_Sign1_Tagged / 18( [
/ protected: / << {
/ algorithm-id / 1: -7 / ES256 /
} >>,
/ unprotected: / {},
/ payload: / null,
/ signature: / h'E9083AA71D2BFCE48253037B9C3116A5EDF23BE0F4B4357A8A835F724660DA7482C64345B4C73DE95F05513BD09FC2E58BD2CC865CC851AD797513A9A951A3CA'
] ) >>
] >>,
/ suit-manifest / 3: << {
/ suit-manifest-version / 1: 1,
/ suit-manifest-sequence-number / 2: 3,
/ suit-common / 3: << {
/ suit-dependencies / 1: [
{
/ suit-dependency-digest / 1: [
/ suit-digest-algorithm-id: / -16 / suit-cose-alg-sha256 /,
/ suit-digest-bytes: / h'F8690E5A86D010BF2B5348ABB99F2254DB7B608D0D626B98DB51AB3ECFC51907'
]
}
],
/ suit-components / 2: [
[
h'544545502D446576696365', / "TEEP-Device" /
h'5365637572654653', / "SecureFS" /
h'636F6E6669672E6A736F6E' / "config.json" /
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]
],
/ suit-common-sequence / 4: << [
/ suit-directive-set-component-index / 12, 0,
/ suit-directive-override-parameters / 20, {
/ suit-parameter-vendor-identifier / 1: h'C0DDD5F15243566087DB4F5B0AA26C2F',
/ suit-parameter-class-identifier / 2: h'DB42F7093D8C55BAA8C5265FC5820F4E',
/ suit-parameter-image-digest / 3: << [
/ suit-digest-algorithm-id: / -16 / suit-cose-alg-sha256 /,
/ suit-digest-bytes: / h'AAABCCCDEEEF00012223444566678889ABBBCDDDEFFF01112333455567778999'
] >>,
/ suit-parameter-image-size / 14: 64
},
/ suit-condition-vendor-idnetifier / 1, 15,
/ suit-condition-class-identifier / 2, 15
] >>
} >>,
/ suit-dependency-resolution / 7: << [
/ suit-directive-set-dependency-index / 13, 0,
/ suit-directive-override-parameters / 20, {
/ suit-parameter-uri / 21: "https://example.org/8d82573a-926d-4754-9353-32dc29997f74.suit"
},
/ suit-directive-fetch / 21, 2,
/ suit-condition-image-match / 3, 15
] >>,
/ suit-install / 9: << [
/ suit-directive-set-dependency-index / 13, 0,
/ suit-directive-process-dependency / 18, 0,
/ suit-directive-set-component-index / 12, 0,
/ suit-directive-override-parameters / 20, {
/ suit-parameter-uri / 21: "https://example.org/config.json"
},
/ suit-directive-fetch / 21, 2,
/ suit-condition-image-match / 3, 15
] >>,
/ suit-validate / 10: << [
/ suit-directive-set-component-index / 12, 0,
/ suit-condition-image-match/ 3, 15
] >>
} >>
} )
CBOR Binary Represenation
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D8 6B # tag(107) / SUIT_Envelope_Tagged /
A2 # map(2)
02 # unsigned(2) / suit-authentication-wrapper: /
58 73 # bytes(115)
82 # array(2)
58 24 # bytes(36)
82 # array(2)
2F # negative(15) / -16 = suit-cose-alg-sha256 /
58 20 # bytes(32)
CE596D785169B72712560B3A246AA98F814498EA3625EEBB72CED9AF273E7FFD
58 4A # bytes(74)
D2 # tag(18) / COSE_Sign1_Tagged /
84 # array(4)
43 # bytes(3)
A1 # map(1)
01 # unsigned(1) / algorithm-id /
26 # negative(6) / -7 = ES256 /
A0 # map(0)
F6 # primitive(22) / null /
58 40 # bytes(64)
E9083AA71D2BFCE48253037B9C3116A5EDF23BE0F4B4357A8A835F724660DA7482C64345B4C73DE95F05513BD09FC2E58BD2CC865CC851AD797513A9A951A3CA
03 # unsigned(3) / suit-manifest: /
59 0134 # bytes(308)
A6 # map(6)
01 # unsigned(1) / suit-manifest-version: /
01 # unsigned(1)
02 # unsigned(2) / suit-manifest-sequence-number: /
03 # unsigned(3)
03 # unsigned(3) / suit-common: /
58 A7 # bytes(167)
A3 # map(3)
01 # unsigned(1) / suit-dependencies: /
81 # array(1)
A1 # map(1)
01 # unsigned(1) suit-dependency-digest: /
82 # array(2)
2F # negative(15) / -16 = suit-cose-alg-sha256 /
58 20 # bytes(32)
F8690E5A86D010BF2B5348ABB99F2254DB7B608D0D626B98DB51AB3ECFC51907
02 # unsigned(2) / suit-components: /
81 # array(1)
83 # array(3)
4B # bytes(11)
544545502D446576696365 # "TEEP-Device"
48 # bytes(8)
5365637572654653 # "SecureFS"
4B # bytes(11)
636F6E6669672E6A736F6E # "config.json"
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04 # unsigned(4) / suit-common-sequence: /
58 57 # bytes(87)
88 # array(8)
0C # unsigned(12) / suit-directive-set-component-index: /
00 # unsigned(0)
14 # unsigned(20) / suit-directive-override-parameters: /
A4 # map(4)
01 # unsigned(1) / suit-parameter-vendor-identifier: /
50 # bytes(16)
C0DDD5F15243566087DB4F5B0AA26C2F
02 # unsigned(2) / suit-parameter-class-identifier: /
50 # bytes(16)
DB42F7093D8C55BAA8C5265FC5820F4E
03 # unsigned(3) / suit-parameter-image-digest: /
58 24 # bytes(36)
82 # array(2)
2F # negative(15) / -16 = suit-cose-alg-sha256 /
58 20 # bytes(32)
AAABCCCDEEEF00012223444566678889ABBBCDDDEFFF01112333455567778999
0E # unsigned(14) / suit-parameter-image-size: /
18 40 # unsigned(64)
01 # unsigned(1) / suit-condition-vendor-identifier: /
0F # unsigned(15)
02 # unsigned(2) / suit-condition-class-identifier: /
0F # unsigned(15)
07 # unsigned(7) / suit-dependency-resolution: /
58 49 # bytes(73)
88 # array(8)
0D # unsigned(13) / suit-directive-set-dependency-index: /
00 # unsigned(0)
14 # unsigned(20) / suit-directive-override-parameters: /
A1 # map(1)
15 # unsigned(21) / suit-parameter-uri: /
78 3D # text(61)
68747470733A2F2F6578616D706C652E6F72672F38643832353733612D393236642D343735342D393335332D3332646332393939376637342E73756974 # "https://example.org/8d82573a-926d-4754-9353-32dc29997f74.suit"
15 # unsigned(21) / suit-directive-fetch: /
02 # unsigned(2)
03 # unsigned(3) / suit-condition-image-match: /
0F # unsigned(15)
09 # unsigned(9) / suit-install: /
58 2F # bytes(47)
8C # array(12)
0D # unsigned(13) / suit-directive-set-dependency-index: /
00 # unsigned(0)
12 # unsigned(18) / suit-directive-process-dependency: /
00 # unsigned(0)
0C # unsigned(12) / suit-directive-set-component-index: /
00 # unsigned(0)
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14 # unsigned(20) / suit-directive-override-parameters: /
A1 # map(1)
15 # unsigned(21) / suit-parameter-uri: /
78 1F # text(31)
68747470733A2F2F6578616D706C652E6F72672F636F6E6669672E6A736F6E # "https://example.org/config.json"
15 # unsigned(21) / suit-directive-fetch: /
02 # unsigned(2)
03 # unsigned(3) / suit-condition-image-match: /
0F # unsigned(15)
0A # unsigned(10) / suit-validate: /
45 # bytes(5)
84 # array(4)
0C # unsigned(12) / suit-directive-set-component-index: /
00
03 # unsigned(3) / suit-condition-image-match: /
0F # unsigned(15)
CBOR Binary in Hex
D86BA2025873825824822F5820CE596D785169B72712560B3A246AA98F81
4498EA3625EEBB72CED9AF273E7FFD584AD28443A10126A0F65840E9083A
A71D2BFCE48253037B9C3116A5EDF23BE0F4B4357A8A835F724660DA7482
C64345B4C73DE95F05513BD09FC2E58BD2CC865CC851AD797513A9A951A3
CA03590134A6010102030358A7A30181A101822F5820DB601ADE73092B58
532CA03FBB663DE49532435336F1558B49BB622726A2FEDD0281834B5445
45502D4465766963654853656375726546534B636F6E6669672E6A736F6E
045857880C0014A40150C0DDD5F15243566087DB4F5B0AA26C2F0250DB42
F7093D8C55BAA8C5265FC5820F4E035824822F5820AAABCCCDEEEF000122
23444566678889ABBBCDDDEFFF011123334555677789990E1840010F020F
075849880D0014A115783D68747470733A2F2F6578616D706C652E6F7267
2F38643832353733612D393236642D343735342D393335332D3332646332
393939376637342E737569741502030F09582F8C0D0012000C0014A11578
1F68747470733A2F2F6578616D706C652E6F72672F636F6E6669672E6A73
6F6E1502030F0A45840C00030F
E.4. Example 4: Unlink a Trusted Component
CBOR Diagnostic Notation of SUIT Manifest
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/ SUIT_Envelope_Tagged / 107( {
/ suit-authentication-wrapper / 2: << [
<< [
/ suit-digest-algorithm-id: / -16 / suit-cose-alg-sha256 /,
/ suit-digest-bytes: / h'632454F19A9440A5B83493628A7EF8704C8A0205A62C34E425BAA34C71341F42'
] >>,
<< / COSE_Sign1_Tagged / 18( [
/ protected / << {
/ algorithm-id / 1: -7 / ES256 /
} >>,
/ unprotected: / {},
/ payload: / null,
/ signature: / h'A32CDB7C1D089C27408CED3C79087220EB0D77F105BB5330912875F4D94AD108D7658C650463AEB7E1CCA5084F22B2F3993176E8B3529A3202ED735E4D39BBBF'
] ) >>
] >>,
/ suit-manifest / 3: << {
/ suit-manifest-version / 1: 1,
/ suit-manifest-sequence-number / 2: 18446744073709551615 / UINT64_MAX /,
/ suit-common / 3: << {
/ suit-components / 2: [
[
h'544545502D446576696365', / "TEEP-Device" /
h'5365637572654653', / "SecureFS" /
h'8D82573A926D4754935332DC29997F74', / tc-uuid /
h'7461' / "ta" /
]
],
/ suit-common-sequence / 4: << [
/ suit-directive-override-parameters / 20, {
/ suit-parameter-vendor-identifier / 1: h'C0DDD5F15243566087DB4F5B0AA26C2F',
/ suit-parameter-class-identifier / 2: h'DB42F7093D8C55BAA8C5265FC5820F4E'
},
/ suit-condition-vendor-identifier / 1, 15,
/ suit-condition-class-identifier / 2, 15
] >>
} >>,
/ suit-install / 9: << [
/ suit-directive-set-component-index: / 12, 0,
/ suit-directive-unlink: / 33, 0
] >>
} >>
} )
CBOR Binary Representation
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D8 6B # tag(107) / SUIT_Envelope_Tagged /
A2 # map(2)
02 # unsigned(2) / suit-authentication-wrapper /
58 73 # bytes(115)
82 # array(2)
58 24 # bytes(36)
82 # array(2)
2F # negative(15) / -16 = suit-cose-alg-sha256 /
58 20 # bytes(32)
632454F19A9440A5B83493628A7EF8704C8A0205A62C34E425BAA34C71341F42
58 4A # bytes(74)
D2 # tag(18) / COSE_Sign1_Tagged /
84 # array(4)
43 # bytes(3)
A1 # map(1)
01 # unsigned(1) / algorithm-id /
26 # negative(6) / -7 = ES256 /
A0 # map(0)
F6 # primitive(22) / null /
58 40 # bytes(64)
A32CDB7C1D089C27408CED3C79087220EB0D77F105BB5330912875F4D94AD108D7658C650463AEB7E1CCA5084F22B2F3993176E8B3529A3202ED735E4D39BBBF
03 # unsigned(3) / suit-manifest: /
58 73 # bytes(115)
A4 # map(4)
01 # unsigned(1) / suit-manifest-version: /
01 # unsigned(1)
02 # unsigned(2) / suit-manifest-sequence-number: /
1B FFFFFFFFFFFFFFFF # unsigned(18446744073709551615)
03 # unsigned(3) / suit-common: /
58 5B # bytes(91)
A2 # map(2)
02 # unsigned(2) / suit-components: /
81 # array(1)
84 # array(4)
4B # bytes(11)
544545502D446576696365 # "TEEP-Device"
48 # bytes(8)
5365637572654653 # "SecureFS"
50 # bytes(16)
8D82573A926D4754935332DC29997F74 # tc-uuid
42 # bytes(2)
7461 # "ta"
04 # unsigned(4) / suit-common-sequence: /
58 2B # bytes(84)
86 # array(6)
14 # unsigned(20) / suit-directive-override-parameters: /
A2 # map(2)
01 # unsigned(1) / suit-parameter-vendor-identifier: /
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50 # bytes(16)
C0DDD5F15243566087DB4F5B0AA26C2F
02 # unsigned(2) / suit-parameter-class-identifier: /
50 # bytes(16)
DB42F7093D8C55BAA8C5265FC5820F4E
01 # unsigned(1) / suit-condition-vendor-identifier: /
0F # unsigned(15)
02 # unsigned(2) / suit-condition-class-identifier: /
0F # unsigned(15)
09 # unsigned(9) / suit-install: /
46 # bytes(6)
84 # array(4)
0C # unsigned(12) / suit-directive-set-component-index: /
00 # unsigned(0)
18 21 # unsigned(33) / suit-directive-unlink: /
00 # unsigned(0)
CBOR Binary in Hex
D86BA2025873825824822F5820632454F19A9440A5B83493628A7EF8704C
8A0205A62C34E425BAA34C71341F42584AD28443A10126A0F65840A32CDB
7C1D089C27408CED3C79087220EB0D77F105BB5330912875F4D94AD108D7
658C650463AEB7E1CCA5084F22B2F3993176E8B3529A3202ED735E4D39BB
BF035873A40101021BFFFFFFFFFFFFFFFF03585BA20281844B544545502D
446576696365485365637572654653508D82573A926D4754935332DC2999
7F7442746104582B8614A20150C0DDD5F15243566087DB4F5B0AA26C2F02
50DB42F7093D8C55BAA8C5265FC5820F4E010F020F0946840C00182100
F. Examples of SUIT Reports
This section shows some examples of SUIT reports.
F.1. Example 1: Success
SUIT Reports have no records if no conditions have failed. The URI
in this example is the reference URI provided in the SUIT manifest.
{
/ suit-report-manifest-digest / 1:<<[
/ algorithm-id / -16 / "sha256" /,
/ digest-bytes / h'a7fd6593eac32eb4be578278e6540c5c'
h'09cfd7d4d234973054833b2b93030609'
]>>,
/ suit-report-manifest-uri / 2: "tam.teep.example/personalisation.suit",
/ suit-report-records / 4: []
}
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F.2. Example 2: Faiure
{
/ suit-report-manifest-digest / 1:<<[
/ algorithm-id / -16 / "sha256" /,
/ digest-bytes / h'a7fd6593eac32eb4be578278e6540c5c09cfd7d4d234973054833b2b93030609'
]>>,
/ suit-report-manifest-uri / 2: "tam.teep.example/personalisation.suit",
/ suit-report-records / 4: [
{
/ suit-record-manifest-id / 1:[],
/ suit-record-manifest-section / 2: 7 / dependency-resolution /,
/ suit-record-section-offset / 3: 66,
/ suit-record-dependency-index / 5: 0,
/ suit-record-failure-reason / 6: 404
}
]
}
where the dependency-resolution refers to:
107({
authentication-wrapper,
/ manifest / 3:<<{
/ manifest-version / 1:1,
/ manifest-sequence-number / 2:3,
common,
dependency-resolution,
install,
validate,
run,
text
}>>,
})
and the suit-record-section-offset refers to:
<<[
/ directive-set-dependency-index / 13,0 ,
/ directive-set-parameters / 19,{
/ uri / 21:'tam.teep.example/'
'edd94cd8-9d9c-4cc8-9216-b3ad5a2d5b8a.suit',
} ,
/ directive-fetch / 21,2 ,
/ condition-image-match / 3,15
]>>,
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Authors' Addresses
Hannes Tschofenig
Arm Ltd.
6067 Absam
Austria
Email: hannes.tschofenig@arm.com
Mingliang Pei
Broadcom
350 Ellis St
Mountain View, CA 94043
United States of America
Email: mingliang.pei@broadcom.com
David Wheeler
Amazon
United States of America
Email: davewhee@amazon.com
Dave Thaler
Microsoft
United States of America
Email: dthaler@microsoft.com
Akira Tsukamoto
AIST
Japan
Email: akira.tsukamoto@aist.go.jp
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