Trusted Execution Environment Provisioning (TEEP) Protocol

4.1. Creating and Validating TEEP Messages

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 by using the data-item-requested parameter. Currently, the following features are supported:¶

• Request for attestation information of the TEEP Agent,¶

• Listing supported extensions,¶

• Querying installed Trusted Components, and¶

• Request for logging information in SUIT Reports.¶

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.¶

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 ],
    ? attestation-payload-format => text,
    ? attestation-payload => bstr,
    ? suit-reports => [ + bstr ],
    * $$query-request-extensions,
    * $$teep-option-extensions
  },
  supported-teep-cipher-suites: [ + $teep-cipher-suite ],
  supported-suit-cose-profiles: [ + $suit-cose-profile ],
  data-item-requested: uint .bits data-item-requested
]

version = uint .size 4
ext-info = uint .size 4

; data items as bitmaps
data-item-requested = &(
  attestation: 0,
  trusted-components: 1,
  extensions: 2,
  suit-reports: 3,
)

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, such as to look up any implementation-specific state it might have saved about that request, or to ignore responses to older QueryRequest messages before some configuration changes were made that affected their content. 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. When the attestation bit is clear then a challenge will be included, which offers replay protection capabilities. The size of the token is at least 8 bytes (64 bits) and maximum of 64 bytes. 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-teep-cipher-suites

The supported-teep-cipher-suites parameter lists the TEEP cipher suites supported by the TAM. Details about the cipher suite encoding can be found in Section 8.1.¶

supported-suit-cose-profiles

The supported-suit-cose-profiles parameter lists the SUIT profiles supported by the TAM for parsing SUIT Reports. Details about the cipher suite encoding can be found in Section 8.2.¶

data-item-requested

The data-item-requested parameter indicates what information the TAM requests from the TEEP Agent in the form of a bitmap.¶

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. It MUST be absent if the attestation bit is clear.¶

challenge

The challenge field is an optional parameter used for ensuring the freshness of attestation Evidence returned with a QueryResponse message. It MUST be absent if the attestation bit is clear or the Passport model is used. When a challenge is provided in the QueryRequest and Evidence in the form of an EAT is returned with a QueryResponse message then the challenge contained in the QueryRequest MUST be used to generate the EAT, by copying the challenge into the eat_nonce claim (Section 4.1 of Section 5) if the nonce-based freshness mechanism is used for attestation Evidence. For more details about freshness of Evidence 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.¶

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. For protocol version 0, the absence of this parameter indicates that the format is "application/eat+cwt; eat_profile=urn:ietf:rfc:rfcXXXX" (see [I-D.ietf-rats-eat-media-type] for further discussion). (RFC-editor: upon RFC publication, replace XXXX above with 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 for the TEEP Agent to use to perform attestation of the TAM. 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 of the TAM as defined by SUIT_Report in Section 4 of [I-D.ietf-suit-report], encoded using COSE as discussed in Section 8.2. SUIT Reports can be useful in QueryRequest messages to pass additional information about the TAM to the TEEP Agent without depending on a Verifier including the relevant information in the TAM's Attestation Results.¶

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.¶

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-version => version,
    ? attestation-payload-format => text,
    ? attestation-payload => bstr,
    ? suit-reports => [ + bstr ],
    ? tc-list => [ + system-property-claims ],
    ? requested-tc-list => [ + requested-tc-info ],
    ? unneeded-manifest-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
}

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-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. For protocol version 0, the absence of this parameter indicates that the format is "application/eat+cwt; eat_profile=urn:ietf:rfc:rfcXXXX" (see [I-D.ietf-rats-eat-media-type] for further discussion). (RFC-editor: upon RFC publication, replace XXXX above with 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 by SUIT_Report in Section 4 of [I-D.ietf-suit-report], encoded using COSE as discussed in Section 8.2. 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.¶

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 [RFC9397] section 6.2.1.¶

unneeded-manifest-list

The unneeded-manifest-list parameter enumerates the SUIT manifests whose components 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 SUIT manifest can be unlinked. Each unneeded SUIT manifest is identified by its SUIT Manifest Component ID (note that this is the Component ID for the manifest itself, which is different from the Component ID of a component installed by the manifest, see [I-D.ietf-suit-trust-domains] for more discussion). A TEEP Agent can get this information from the UnrequestTA conceptual API defined in [RFC9397] 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.¶

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 [RFC9334]) 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),
    ? unneeded-manifest-list => [ + SUIT_Component_Identifier ],
    ? manifest-list => [ + bstr .cbor SUIT_Envelope ],
    ? attestation-payload-format => text,
    ? attestation-payload => bstr,
    ? err-code => (0..23),
    ? err-msg => text .size (1..128),
    * $$update-extensions,
    * $$teep-option-extensions
  }
]

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.¶

unneeded-manifest-list

The unneeded-manifest-list parameter enumerates the SUIT manifests to be unlinked. Each unneeded SUIT manifest is identified by its SUIT Manifest Component ID. The SUIT manifest processor MAY execute uninstall section in the manifest. See Section 7 of [I-D.ietf-suit-trust-domains] for more information about the suit-uninstall Command Sequence.¶

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; eat_profile=urn:ietf:rfc:rfcXXXX" (see [I-D.ietf-rats-eat-media-type] for further discussion). (RFC-editor: upon RFC publication, replace XXXX above with 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.¶

err-code

The err-code parameter contains one of the error codes listed in the Section 4.6, which describes the reasons for the error when performing QueryResponse in the TAM.¶

err-msg

The err-msg parameter is human-readable diagnostic text that MUST be encoded using UTF-8 [RFC3629] in Net-Unicode format [RFC5198] with a maximum of 128 bytes.¶

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 [RFC9397] for further discussion.¶

The Update Message has a SUIT_Envelope containing SUIT manifests. Following are some example scenarios using SUIT manifests in the Update Message.¶

    +------------+           +-------------+
    | TAM        |           | TEEP Agent  |
    +------------+           +-------------+

             Update  ---->

    +=================== teep-protocol(TAM) ==================+
    | TEEP_Message([                                          |
    |   TEEP-TYPE-update,                                     |
    |   options: {                                            |
    |     manifest-list: [                                    |
    |       += suit-manifest "tc-uuid" (TC Developer) ======+ |
    |       | SUIT_Envelope({                               | |
    |       |   manifest: {                                 | |
    |       |     install: {                                | |
    |       |       override-parameters: {                  | |
    |       |         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

    +------------+           +-------------+
    | TAM        |           | TEEP Agent  |
    +------------+           +-------------+

             Update  ---->

      +=========== teep-protocol(TAM) ============+
      | TEEP_Message([                            |
      |   TEEP-TYPE-update,                       |
      |   options: {                              |
      |     manifest-list: [                      |
      |       +== suit-manifest(TC Developer) ==+ |
      |       | SUIT_Envelope({                 | |
      |       |   manifest: {                   | |
      |       |     install: {                  | |
      |       |       override-parameters: {    | |
      |       |         uri: "#tc"              | |
      |       |       },                        | |
      |       |       fetch                     | |
      |       |     }                           | |
      |       |   },                            | |
      |       |   "#tc": h'48 65 6C 6C ...'     | |
      |       | })                              | |
      |       +=================================+ |
      |     ]                                     |
      |   }                                       |
      | ])                                        |
      +===========================================+

    Figure 3: Integrated Payload with Trusted Component Binary

    +------------+           +-------------+
    | TAM        |           | TEEP Agent  |
    +------------+           +-------------+

             Update  ---->

      +================== teep-protocol(TAM) ======================+
      | TEEP_Message([                                             |
      |   TEEP-TYPE-update,                                        |
      |   options: {                                               |
      |     manifest-list: [                                       |
      |       +========= suit-manifest(TC Developer) ============+ |
      |       | SUIT_Envelope({                                  | |
      |       |   manifest: {                                    | |
      |       |     common: {                                    | |
      |       |       dependencies: {                            | |
      |       |         dependency-prefix 1: {                   | |
      |       |           [tc-uuid, 'suit']                      | |
      |       |         }                                        | |
      |       |       }                                          | |
      |       |       components: [                              | |
      |       |         ['config.json']                          | |
      |       |       ]                                          | |
      |       |     },                                           | |
      |       |     dependency-resolution: {                     | |
      |       |       override-parameters: {                     | |
      |       |         uri: "https://example.org/tc-uuid"       | |
      |       |       },                                         | |
      |       |       fetch                                      | |
      |       |     },                                           | |
      |       |     install: {                                   | |
      |       |       set-component-index 0,                     | |
      |       |       override-parameters: {                     | |
      |       |         content: h'48FE0794...'                  | |
      |       |         encryption-info: << ... >>               | |
      |       |       },                                         | |
      |       |       write,                                     | |
      |       |       set-component-index 1,                     | |
      |       |       process-dependency                         | |
      |       |     }                                            | |
      |       |   }                                              | |
      |       | })                                               | |
      |       +==================================================+ |
      |     ]                                                      |
      |   }                                                        |
      | ])                                                         |
      +============================================================+

    Figure 4: Encrypted Personalization Data

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.¶

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 a message from the TAM.¶

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.¶

teep-error = [
  type: TEEP-TYPE-teep-error,
  options: {
     ? token => bstr .size (8..64),
     ? err-msg => text .size (1..128),
     ? supported-teep-cipher-suites => [ + $teep-cipher-suite ],
     ? supported-freshness-mechanisms => [ + $freshness-mechanism ],
     ? supported-suit-cose-profiles => [ + $suit-cose-profile ],
     ? challenge => bstr .size (8..512),
     ? versions => [ + version ],
     ? suit-reports => [ + SUIT_Report ],
     * $$teep-error-extensions,
     * $$teep-option-extensions
  },
  err-code: (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_ATTESTATION_REQUIRED = 7
ERR_UNSUPPORTED_SUIT_REPORT = 8
ERR_CERTIFICATE_EXPIRED = 9
ERR_TEMPORARY_ERROR = 10
ERR_MANIFEST_PROCESSING_FAILED = 17

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 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-teep-cipher-suites

The supported-teep-cipher-suites parameter lists the TEEP cipher suite(s) supported by the TEEP Agent. Details about the cipher suite encoding can be found in Section 8.1. 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.¶

supported-suit-cose-profiles

The supported-suit-cose-profiles parameter lists the SUIT profiles supported by the TEEP Agent. Details about the cipher suite encoding can be found in Section 8.2. This otherwise optional parameter MUST be returned if err-code is ERR_UNSUPPORTED_SUIT_REPORT.¶

challenge

The challenge field is an optional parameter used for ensuring the freshness of attestation Evidence included with a QueryRequest message. When a challenge is provided in the Error message and Evidence in the form of an EAT is returned with a QueryRequest message then the challenge contained in the Error message MUST be used to generate the EAT, by copying the challenge value into the eat_nonce claim, as described in the EAT profile Section 5, if the nonce-based freshness mechanism is used. 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 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 received TEEP message 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 field. A TEEP implementation receiving this error might refuse to communicate further with the problematic TEEP message sender, by silently dropping any TEEP messages received, 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 aggressive retry is warranted.¶

ERR_UNSUPPORTED_EXTENSION (2)

The TEEP implementation does not support an extension included in the TEEP message it received. For diagnosis purposes it is RECOMMMENDED to identify the unsupported extension in the error message field. A TAM implementation receiving this error might retry sending the last message it sent to the sender of this error, without using any TEEP 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 implementation does not support the TEEP protocol version indicated in the received message. A TAM receiving this error might retry the request using a different TEEP protocol version.¶

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 field. For example, the certificate was of an unsupported type, or the certificate was revoked by its signer. A TEEP implementation receiving this error might attempt to use an alternate certificate.¶

ERR_ATTESTATION_REQUIRED (7)

Indicates that the TEEP implementation sending this error requires attestation of the TEEP imlementation receiving this error.¶

ERR_UNSUPPORTED_SUIT_REPORT (8)

Indicates that the TEEP Agent does not support the suit-cose-profile of the SUIT Reports which was sent by the TAM. The TEEP Agent must report the error code ERR_UNSUPPORTED_SUIT_REPORT supplying the supported-suit-cose-profiles.¶

ERR_CERTIFICATE_EXPIRED (9)

A certificate has expired or is not currently valid. A TEEP implementation 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 TEEP message. A TEEP implementation receiving this error might retry the last message it sent to the sender of this error at some later point, which is up to the implementation.¶

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.¶

5.1. Relationship to AR4SI

[I-D.ietf-rats-ar4si] defines an EAT profile for arbitrary Relying Parties to use with Attestation Results. However the TAM as a Relying Party needs specific claims that are not required in the AR4SI profile, and so needs its own more specific profile.¶

In some deployments, a TAM can be used as an intermediary between Verifier and a TEEP Agent acting as an Attester in the Passport model or acting as a Relying Party in the Background Check Model of [RFC9334]. This is depicted in the example in Figure 1. In such a case, both profiles need to be obtained from the Verifier: one for use by the TAM itself, and the other to pass on to the TEEP Agent.¶

When the TAM and Verifier are combined into the same implementation, obtaining both profiles can be straightforward, but when they are on different machines, the situation is more complex, especially if Nonces are used to ensure freshness of Evidence. There are thus several such cases:¶

1. The protocol between the TAM and the Verifier (which is outside the scope of TEEP itself) allows requesting multiple Attestation Results from the same Evidence. In this case, the TAM can request both EAT profiles be returned.¶

2. The protocol between the TAM and the Verifier only allows requesting one Attestation Result format, but the Evidence freshness mechanism does not use Nonces. In this case, the TAM can send the same Evidence in two separate requests, each requesting a different EAT profile for the Attestation Results.¶

3. The protocol between the TAM and the Verifier only allows requesting one Attestation Result format, and the Evidence freshness mechanism uses Nonces. In this case, it is simpler to not have the TAM be an intermediary, since the Verifier will require a separate Nonce for each Attestation Result, but have the Attester or Relying Party contact the Verifier directly to get Attestation Results in the AR4SI profile.¶

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. It may also do additional implementation specific actions such as logging the results or attempting to update the TEEP Agent to a version that does not send invalid messages. 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.¶

7.2. 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.¶

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 if it is not valid then the Agent responds with an Error message. Otherwise, processing continues as follows based on the type of message.¶

8.1. TEEP Messages

The TEEP protocol uses COSE for protection of TEEP messages 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.¶

; teep-cipher-suites
$teep-cipher-suite /= teep-cipher-suite-sign1-eddsa
$teep-cipher-suite /= teep-cipher-suite-sign1-es256

;The following two cipher suites have only a single operation each.
;Other cipher suites may be defined to have multiple operations.
;It is MANDATORY for TAM to support them, 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, cose-alg-eddsa ]
teep-operation-sign1-es256 = [ cose-sign1, cose-alg-es256 ]

teep-cipher-suite-sign1-eddsa = [ teep-operation-sign1-eddsa ]
teep-cipher-suite-sign1-es256 = [ teep-operation-sign1-es256 ]

;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 = 18      ; CoAP Content-Format value

;MANDATORY for TAM to support the following, and OPTIONAL to implement
;any additional algorithms from the IANA COSE Algorithms registry.

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 [RFC9052] 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 [RFC9397] 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 [RFC9397].¶

The cipher suites defined above do not do encryption at the TEEP layer, but permit encryption of the SUIT payload using a mechanism such as [I-D.ietf-suit-firmware-encryption]. See Section 10 and Section 8.2 for more discussion of specific payloads.¶

For the initial QueryRequest message, unless the TAM has more specific knowledge about the TEEP Agent (e.g., if the QueryRequest is sent in response to some underlying transport message that contains a hint), the message does not use COSE_Sign1 with one of the above cipher suites, but instead uses COSE_Sign with multiple signatures, one for each algorithm used in any of the cipher suites listed in the supported-teep-cipher-suites parameter of the QueryRequest, so that a TEEP Agent supporting any one of them can verify a signature. If the TAM does have specific knowledge about which cipher suite the TEEP Agent supports, it MAY instead use that cipher suite with the QueryRequest.¶

For an Error message with code ERR_UNSUPPORTED_CIPHER_SUITES, the TEEP Agent MUST protect it with any of the cipher suites mandatory for the TAM.¶

For all other TEEP messages between the TAM and TEEP Agent, the selected TEEP cipher suite MUST be used in both directions.¶

8.2. EATs and SUIT Reports

TEEP uses COSE for confidentiality of EATs and SUIT Reports sent by a TEEP Agent. The TEEP Agent obtains a signed EAT and then SHOULD encrypt it using the TAM as the recipient. A SUIT Report is created by a SUIT processor, which is part of the TEEP Agent itself. The TEEP Agent is therefore in control of signing the SUIT Report and SHOULD encrypt it. Again, the TAM is the recipient of the encrypted content. For content-key distribution Ephemeral-Static Diffie-Hellman (ES-DH) is used in this specification. See Section 8.5.5 and Appendix B of [RFC9052] for more details. (If [I-D.ietf-suit-firmware-encryption] is used, it is also the same as discussed in Section 6.2 of that document.)¶

ES-DH is a scheme that provides public key encryption given a recipient's public key. Hence, the TEEP Agent needs to be in possession of the public key of the TAM. See Section 5 of [RFC9397] for more discussion of TAM keys used by the TEEP Agent. There are multiple variants of this scheme; this document uses the variant specified in Section 8.5.5 of [RFC9052].¶

The following two layer structure is used:¶

• Layer 0: Has a content encrypted with the Content Encryption Key (CEK), a symmetric key. For encrypting SUIT Reports and EATs the content MUST NOT be detached.¶

• Layer 1: Uses the AES Key Wrap algorithm to encrypt the randomly generated CEK with the Key Encryption Key (KEK) derived with ES-DH, whereby the resulting symmetric key is fed into the HKDF-based key derivation function.¶

As a result, the two layers combine ES-DH with AES-KW and HKDF.¶

This document re-uses the CDDL defined in Section 6.2.3 of [I-D.ietf-suit-firmware-encryption] and the context information structure defined in Section 6.2.4 of [I-D.ietf-suit-firmware-encryption] although with an important modification. The COSE_KDF_Context.SuppPubInfo.other value MUST be set to "SUIT Report Encryption" when a SUIT Report is encrypted and MUST be set to "EAT Encryption" when an EAT is encrypted. The COSE_KDF_Context.SuppPubInfo.other field captures the protocol in which the ES-DH content key distribution algorithm is used.¶

This specification defines cipher suites for confidentiality protection of EATs and SUIT Reports. The TAM MUST support each cipher suite defined below, based on definitions in [I-D.ietf-suit-mti]. A TEEP Agent MUST support at least one of the cipher suites below 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 other algorithms in the COSE Algorithms registry. It MAY also support use with COSE_Encrypt or other COSE types in additional cipher suites.¶

; suit-cose-profile
$suit-cose-profile /= suit-sha256-es256-ecdh-a128ctr
$suit-cose-profile /= suit-sha256-eddsa-ecdh-a128ctr
$suit-cose-profile /= suit-sha256-es256-ecdh-a128gcm
$suit-cose-profile /= suit-sha256-eddsa-ecdh-chacha-poly

12.1. Media Type Registration

IANA is requested to assign a media type for application/teep+cbor.¶

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 [RFC8949].¶

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¶

D.1. QueryRequest Message

/ query-request = /
[
  / type: / 1 / TEEP-TYPE-query-request /,
  / options: /
  {
    / token / 20 : h'A0A1A2A3A4A5A6A7A8A9AAABACADAEAF',
    / versions / 3 : [ 0 ]  / 0 is current TEEP Protocol /
  },
  / supported-teep-cipher-suites: / [
    [ [ 18, -7 ] ] / Sign1 using ES256 /,
    [ [ 18, -8 ] ] / Sign1 using EdDSA /
  ],
  / supported-suit-cose-profiles: / [
    [-16, -7, -29, -65534] / suit-sha256-es256-ecdh-a128ctr /,
    [-16, -8, -29, -65534] / suit-sha256-eddsa-ecdh-a128ctr /,
    [-16, -7, -29, 1]      / suit-sha256-es256-ecdh-a128gcm /,
    [-16, -8, -29, 24]     / suit-sha256-eddsa-ecdh-chacha-poly /
  ],
  / data-item-requested: / 3 / attestation | trusted-components /
]

85                  # array(5)
   01               # unsigned(1) / TEEP-TYPE-query-request /
   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-teep-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 /
   84               # array(4) / supported-suit-cose-profiles /
      84            # array(4) / suit-sha256-es256-ecdh-a128ctr /,
         2f         # negative(15) / -16 = SHA-256 /
         26         # negative(6) / -7 = ES256 /
         38 1C      # negative(28) / -29 = ECDH-ES + A128KW /
         39 fffd    # negative(65533) / -65534 = A128CTR /
      84            # array(4) / suit-sha256-eddsa-ecdh-a128ctr /
         2f         # negative(15) / -16 = SHA-256 /
         27         # negative(7) / -8 = EdDSA /
         38 1C      # negative(28) / -29 = ECDH-ES + A128KW /
         39 fffd    # negative(65533) / -65534 = A128CTR /
      84            # array(4) / suit-sha256-es256-ecdh-a128gcm /
         2f         # negative(15) / -16 = SHA-256 /
         26         # negative(6) / -7 = ES256 /
         38 1C      # negative(28) / -29 = ECDH-ES + A128KW /
         01         # unsigned(1) / A128GCM /
      84            # array(4) / suit-sha256-eddsa-ecdh-chacha-poly /
         2f         # negative(15) / -16 = SHA-256 /
         27         # negative(7) / EdDSA /
         38 1C      # negative(28) / -29 = ECDH-ES + A128KW /
         18 18      # unsigned(24) / 24 = ChaCha20/Poly1305 /
   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.¶

/ eat-claim-set = /
{
    / cnf /          8: {
                         / kid / 3 : h'ba7816bf8f01cfea414140de5dae2223'
                                     h'b00361a396177a9cb410ff61f20015ad'
                        },
    / eat_nonce /   10: h'948f8860d13a463e8e',
    / ueid /       256: h'0198f50a4ff6c05861c8860d13a638ea',
    / oemid /      258: h'894823', / IEEE OUI format OEM ID /
    / hwmodel /    259: h'549dcecc8b987c737b44e40f7c635ce8'
                          / Hash of chip model name /,
    / hwversion /  260: ["1.3.4", 1], / Multipartnumeric  /
    / manifests /  273: [
                          [ 60, / application/cbor, TO BE REPLACED /
                                / with the format value for a /
                                / SUIT_Reference once one is allocated /
                            {   / SUIT_Reference /
                              / suit-report-manifest-uri / 1: "https://example.com/manifest.cbor",
                              / suit-report-manifest-digest / 0:[
                                / algorithm-id / -16 / "sha256" /,
                                / digest-bytes / h'a7fd6593eac32eb4be578278e6540c5c'
                                                 h'09cfd7d4d234973054833b2b93030609'
                                ]
                            }
                          ]
                        ]
}

D.3. QueryResponse Message

/ query-response = /
[
  / type: / 2 / TEEP-TYPE-query-response /,
  / options: /
  {
    / token / 20 : h'A0A1A2A3A4A5A6A7A8A9AAABACADAEAF',
    / selected-version / 6 : 0,
    / attestation-payload / 7 : h'' / empty only for example purpose /,
    / tc-list / 8 : [
      {
        / system-component-id / 0 : [ h'0102030405060708090A0B0C0D0E0F' ],
        / suit-parameter-image-digest / 3: << [
          / suit-digest-algorithm-id / -16 / SHA256 /,
          / suit-digest-bytes / h'A7FD6593EAC32EB4BE578278E6540C5C09CFD7D4D234973054833B2B93030609'
            / SHA256 digest of tc binary /
        ] >>
      }
    ]
  }
]

82                  # array(2)
   02               # unsigned(2) / TEEP-TYPE-query-response /
   A4               # map(4)
      14            # unsigned(20) / token: /
      50            # bytes(16)
         A0A1A2A3A4A5A6A7A8A9AAABACADAEAF
      06            # unsigned(6) / selected-version: /
      00            # unsigned(0)
      07            # unsigned(7) / attestation-payload: /
      40            # bytes(0)
                    # ""
      08            # unsigned(8) / tc-list: /
      81            # array(1)
         A2         # map(2)
            00      # unsigned(0) / system-component-id: /
            81      # array(1)
               4F   # bytes(15)
                  0102030405060708090A0B0C0D0E0F
            03      # unsigned(3) / suit-parameter-image-digest: /
            58 24   # bytes(36)
               822F5820A7FD6593EAC32EB4BE578278E6540C5C09CFD7D4D234973054833B2B93030609

D.4. Update Message

/ update = /
[
  / type: / 3 / TEEP-TYPE-update /,
  / options: /
  {
    / token / 20 : h'A0A1A2A3A4A5A6A7A8A9AAABACADAEAF',
    / manifest-list / 10 : [
      <<
        / SUIT_Envelope / {
          / 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 /
              } >>,
              / 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
            ] >>
          } >>
        }
      >>
    ] / array of bstr wrapped SUIT_Envelope /
  }
]

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: /
      81            # array(1)
         59 014E    # bytes(336)
            A2025873825824822F5820DB601ADE73092B58532CA03FBB663DE495
            32435336F1558B49BB622726A2FEDD584AD28443A10126A0F658405B2D53
            5A2B6D5E3C585C1074F414DA9E10BD285C99A33916DADE3ED38812504817
            AC48B62B8E984EC622785BD1C411888BE531B1B594507816B201F6F28579
            A40358D4A401010203035884A20281844B544545502D4465766963654853
            65637572654653508D82573A926D4754935332DC29997F74427461045854
            8614A40150C0DDD5F15243566087DB4F5B0AA26C2F0250DB42F7093D8C55
            BAA8C5265FC5820F4E035824822F58208CF71AC86AF31BE184EC7A05A411
            A8C3A14FD9B77A30D046397481469468ECE80E14010F020F0958458614A1
            15783B68747470733A2F2F6578616D706C652E6F72672F38643832353733
            612D393236642D343735342D393335332D3332646332393939376637342E
            7461150F030F

D.5. Success Message

/ teep-success = /
[
  / type: / 5 / TEEP-TYPE-teep-success /,
  / options: /
  {
    / token / 20 : h'A0A1A2A3A4A5A6A7A8A9AAABACADAEAF'
  }
]

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

/ 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 /
]

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 /

Example 1: SUIT Manifest pointing to URI of the Trusted Component Binary

/ SUIT_Envelope / {
  / authentication-wrapper / 2: << [
    << [
      / digest-algorithm-id: / -16 / SHA256 /,
      / digest-bytes: / h'EF53C7F719CB10041233850AE3211D62CEC9528924E656607688E77BC14886A0'
    ] >>,
    << / COSE_Sign1_Tagged / 18([
      / protected: / << {
        / algorithm-id / 1: -7 / ES256 /
      } >>,
      / unprotected: / {},
      / payload: / null,
      / signature: / h'7E367F9E124859473FBDF3D6312AA8943617B41AE4782FCA0E77A492C51F8A7252EA42C23D722E787AA235B5175DBE61DDF8F16F956E0317B9550A04BF9165DD'
    ]) >>
  ] >>,
  / manifest / 3: << {
    / manifest-version / 1: 1,
    / manifest-sequence-number / 2: 3,
    / common / 3: << {
      / components / 2: [
        [
           'TEEP-Device',
           'SecureFS',
          h'8D82573A926D4754935332DC29997F74', / tc-uuid /
           'ta'
        ]
      ],
      / shared-sequence / 4: << [
        / directive-override-parameters / 20, {
          / parameter-vendor-identifier / 1: h'C0DDD5F15243566087DB4F5B0AA26C2F',
          / parameter-class-identifier / 2: h'DB42F7093D8C55BAA8C5265FC5820F4E',
          / parameter-image-digest / 3: << [
            / digest-algorithm-id: / -16 / SHA256 /,
            / digest-bytes: / h'8CF71AC86AF31BE184EC7A05A411A8C3A14FD9B77A30D046397481469468ECE8'
          ] >>,
          / parameter-image-size / 14: 20
        },
        / condition-vendor-identifier / 1, 15,
        / condition-class-identifier / 2, 15
      ] >>
    } >>,
    / manifest-component-id / 5: [
       'TEEP-Device',
       'SecureFS',
      h'8D82573A926D4754935332DC29997F74',  / tc-uuid /
       'suit'
    ],
    / install / 17: << [
      / directive-override-parameters / 20, {
        / parameter-uri / 21: "https://example.org/8d82573a-926d-4754-9353-32dc29997f74.ta"
      },
      / directive-fetch / 21, 15,
      / condition-image-match / 3, 15
    ] >>,
    / uninstall / 24: << [
      / directive-unlink / 33, 15
    ] >>
  } >>
}

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14A40150C0DDD5F15243566087DB4F5B0AA26C2F0250DB42F7093D8C55BA
A8C5265FC5820F4E035824822F58208CF71AC86AF31BE184EC7A05A411A8
C3A14FD9B77A30D046397481469468ECE80E14010F020F05844B54454550
2D446576696365485365637572654653508D82573A926D4754935332DC29
997F7444737569741158458614A115783B68747470733A2F2F6578616D70
6C652E6F72672F38643832353733612D393236642D343735342D39333533
2D3332646332393939376637342E7461150F030F1818448218210F

Example 2: SUIT Manifest including the Trusted Component Binary

/ SUIT_Envelope / {
  / authentication-wrapper / 2: << [
    << [
      / digest-algorithm-id: / -16 / SHA256 /,
      / digest-bytes: / h'526A85341DE35AFA4FAF9EDDDA40164525077DC45DFBE25785B9FF40683EE881'
    ] >>,
    << / COSE_Sign1_Tagged / 18([
      / protected: / << {
        / algorithm-id / 1: -7 / ES256 /
      } >>,
      / unprotected: / {},
      / payload: / null,
      / signature: / h'4B57A8102D0D86B83BA0368E118917D87DBF7815DC31B19DEB7E154F3D191A1434ADFAE27D5AED39C07A2A4B2A0D78031E73B23D679507C4953DD9E00CA7E541'
    ]) >>
  ] >>,
  / manifest / 3: << {
    / manifest-version / 1: 1,
    / manifest-sequence-number / 2: 3,
    / common / 3: << {
      / components / 2: [
        [
           'TEEP-Device',
           'SecureFS',
          h'8D82573A926D4754935332DC29997F74', / tc-uuid /
           'ta'
        ]
      ],
      / shared-sequence / 4: << [
        / directive-override-parameters / 20, {
          / parameter-vendor-identifier / 1: h'C0DDD5F15243566087DB4F5B0AA26C2F',
          / parameter-class-identifier / 2: h'DB42F7093D8C55BAA8C5265FC5820F4E',
          / parameter-image-digest / 3: << [
            / digest-algorithm-id: / -16 / SHA256 /,
            / digest-bytes: / h'8CF71AC86AF31BE184EC7A05A411A8C3A14FD9B77A30D046397481469468ECE8'
          ] >>,
          / parameter-image-size / 14: 20
        },
        / condition-vendor-identifier / 1, 15,
        / condition-class-identifier / 2, 15
      ] >>
    } >>,
    / manifest-component-id / 5: [
       'TEEP-Device',
       'SecureFS',
      h'8D82573A926D4754935332DC29997F74',  / tc-uuid /
       'suit'
    ],
    / install / 17: << [
      / directive-override-parameters / 20, {
        / parameter-uri / 21: "#tc"
      },
      / directive-fetch / 21, 15,
      / condition-image-match / 3, 15
    ] >>,
    / uninstall / 24: << [
      / directive-unlink / 33, 15
    ] >>
  } >>,
  "#tc" : 'Hello, Secure World!'
}

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0D86B83BA0368E118917D87DBF7815DC31B19DEB7E154F3D191A1434ADFA
E27D5AED39C07A2A4B2A0D78031E73B23D679507C4953DD9E00CA7E54103
58CEA601010203035884A20281844B544545502D44657669636548536563
7572654653508D82573A926D4754935332DC29997F744274610458548614
A40150C0DDD5F15243566087DB4F5B0AA26C2F0250DB42F7093D8C55BAA8
C5265FC5820F4E035824822F58208CF71AC86AF31BE184EC7A05A411A8C3
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446576696365485365637572654653508D82573A926D4754935332DC2999
7F744473756974114C8614A11563237463150F030F1818448218210F6323
74635448656C6C6F2C2053656375726520576F726C6421

Example 3: Supplying Personalization Data for Trusted Component Binary

This example uses the following parameters:¶

• SUIT Profile: suit-sha256-es256-ecdh-a128ctr (see [I-D.ietf-suit-mti] Section 3.2)¶

  • Algorithm for payload encryption: A128CTR (-65534)¶

  • Algorithm for key wrap: ECDH-ES + A128KW (-29)¶

• KEK (Receiver's Private Key):¶

  • kty: EC2¶

  • crv: P-256¶

  • x: h'5886CD61DD875862E5AAA820E7A15274C968A9BC96048DDCACE32F50C3651BA3'¶

  • y: h'9EED8125E932CD60C0EAD3650D0A485CF726D378D1B016ED4298B2961E258F1B'¶

  • d: h'60FE6DD6D85D5740A5349B6F91267EEAC5BA81B8CB53EE249E4B4EB102C476B3'¶

• COSE_KDF_Context¶

  • AlgorithmID: -3 (A128KW)¶

  • SuppPubInfo¶

    • keyDataLength: 128¶

    • protected: << {/ alg / 1: -29 / ECDH-ES+A128KW / } >>¶

    • other: 'SUIT Payload Encryption'¶

/ SUIT_Envelope / {
  / authentication-wrapper / 2: << [
    << [
      / digest-algorithm-id: / -16 / SHA256 /,
      / digest-bytes: / h'FE6CF752367398A8BEBF0EE521242560FF495CBA08883AEDAF8CC4DC5E0DA444'
    ] >>,
    << / COSE_Sign1_Tagged / 18([
      / protected: / << {
        / algorithm-id / 1: -7 / ES256 /
      } >>,
      / unprotected: / {},
      / payload: / null,
      / signature: / h'DEA71FE757D211B86796EDB058A82F85F93DD95B5494AEC284E19330E376BFDDCAFA97D336F776890ED37B7B068904AD92E0F1657FE3935D78B4AB083ACFCA09'
    ]) >>
  ] >>,
  / manifest / 3: << {
    / manifest-version / 1: 1,
    / manifest-sequence-number / 2: 3,
    / common / 3: << {
      / dependencies / 1: {
        / component-index / 1: {
          / dependency-prefix / 1: [
             'TEEP-Device',
             'SecureFS',
            h'8D82573A926D4754935332DC29997F74', / tc-uuid /
             'suit'
          ]
        }
      },
      / components / 2: [
        [
          'TEEP-Device',
          'SecureFS',
          'config.json'
        ]
      ],
      / shared-sequence / 4: << [
        / directive-set-component-index / 12, 0,
        / directive-override-parameters / 20, {
          / parameter-vendor-identifier / 1: h'C0DDD5F15243566087DB4F5B0AA26C2F',
          / parameter-class-identifier / 2: h'DB42F7093D8C55BAA8C5265FC5820F4E'
        },
        / condition-vendor-identifier / 1, 15,
        / condition-class-identifier / 2, 15
      ] >>
    } >>,
    / manifest-component-id / 5: [
      'TEEP-Device',
      'SecureFS',
      'config.suit'
    ],
    / validate / 7: << [
      / directive-set-component-index / 12, 0,
      / directive-override-parameters / 20, {
        / NOTE: image-digest and image-size of plaintext config.json /
        / parameter-image-digest / 3: << [
          / digest-algorithm-id: / -16 / SHA256 /,
          / digest-bytes: / h'8273468FB64BD84BB04825F8371744D952B751C73A60F455AF681E167726F116'
        ] >>,
        / image-size / 14: 61
      },
      / condition-image-match / 3, 15
    ] >>,
    / dependency-resolution / 15: << [
      / directive-set-component-index / 12, 1,
      / directive-override-parameters / 20, {
        / parameter-image-digest / 3: << [
          / algorithm-id / -16 / SHA256 /,
          / digest-bytes / h'EF53C7F719CB10041233850AE3211D62CEC9528924E656607688E77BC14886A0'
        ] >>,
        / parameter-image-size / 14: 389,
        / parameter-uri / 21: "https://example.org/8d82573a-926d-4754-9353-32dc29997f74.suit"
      },
      / directive-fetch / 21, 2
    ] >>,
    / install / 17: << [
      / directive-set-component-index / 12, 1,
      / directive-process-dependency / 11, 0,

      / NOTE: fetch encrypted firmware /
      / directive-set-component-index / 12, 0,
      / directive-override-parameters / 20, {
        / NOTE: encrypted payload and encryption-info /
        / parameter-content / 18: h'6D5BE4F569E98AE01F38B071EF025437B742FF28854AB32C868BC6A76CD33B5CA112FF22BA95EA4672B7199C89A7829183794A21A6BE345C4371DCB0DC',
        / parameter-encryption-info / 19: << 96([
          / protected: / h'',
          / unprotected: / {
            / alg / 1: -65534 / A128CTR /,
            / IV / 5: h'67E3BA7CD42D02BBC39C508B5EA0F1C4'
          },
          / payload: / null / detached ciphertext /,
          / recipients: / [
            [
              / protected: / << {
                / alg / 1: -29 / ECDH-ES + A128KW /
              } >>,
              / unprotected: / {
                / ephemeral key / -1: {
                  / kty / 1: 2 / EC2 /,
                  / crv / -1: 1 / P-256 /,
                  / x / -2: h'F2452399667F57993B14C5F1107F667884854C190894FC08531C1E2290A7BA19',
                  / y / -3: h'275EDDE29FD75C9393AFFA706F8FAD3C49D03D67D47F8B0C027BE5F0BCA884CB'
                }
              },
              / payload: / h'7D806DA1ACEC6F704D803F0CFE7420525C81E1957699FCCE'
            ]
          ]
        ]) >>
      },

      / decrypt encrypted firmware /
      / directive-write / 18, 15 / consumes the SUIT_Encryption_Info above /
      / NOTE: decrypted payload would be ``{"name":"FOO Bar","secret":"0123456789abfcdef0123456789abcd"}'' /
    ] >>,
    / uninstall / 24: << [
      / directive-set-component-index / 12, 1,
      / directive-process-dependency / 11, 0,
      / directive-set-component-index / 12, 0,
      / directive-unlink / 33, 15
    ] >>
  } >>
}

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4A880C010B000C0018210F

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-report-records / 4: []
}

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-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:¶

{
  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',
    } ,
  / directive-fetch / 21,2,
  / condition-image-match / 3,15
]>>,