draft-ietf-rats-eat-01.txt   draft-ietf-rats-eat-02.txt 
RATS Working Group G. Mandyam RATS Working Group G. Mandyam
Internet-Draft Qualcomm Technologies Inc. Internet-Draft Qualcomm Technologies Inc.
Intended status: Standards Track L. Lundblade Intended status: Standards Track L. Lundblade
Expires: January 5, 2020 Security Theory LLC Expires: July 12, 2020 Security Theory LLC
M. Ballesteros M. Ballesteros
J. O'Donoghue J. O'Donoghue
Qualcomm Technologies Inc. Qualcomm Technologies Inc.
July 04, 2019 January 09, 2020
The Entity Attestation Token (EAT) The Entity Attestation Token (EAT)
draft-ietf-rats-eat-01 draft-ietf-rats-eat-02
Abstract Abstract
An Entity Attestation Token (EAT) provides a signed (attested) set of An Entity Attestation Token (EAT) provides a signed (attested) set of
claims that describe state and characteristics of an entity, claims that describe state and characteristics of an entity,
typically a device like a phone or an IoT device. These claims are typically a device like a phone or an IoT device. These claims are
used by a relying party to determine how much it wishes to trust the used by a relying party to determine how much it wishes to trust the
entity. entity.
An EAT is either a CWT or JWT with some attestation-oriented claims. An EAT is either a CWT or JWT with some attestation-oriented claims.
skipping to change at page 1, line 45 skipping to change at page 1, line 45
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time. It is inappropriate to use Internet-Drafts as reference time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress." material or to cite them other than as "work in progress."
This Internet-Draft will expire on January 5, 2020. This Internet-Draft will expire on July 12, 2020.
Copyright Notice Copyright Notice
Copyright (c) 2019 IETF Trust and the persons identified as the Copyright (c) 2020 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
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Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1. CDDL, CWT and JWT . . . . . . . . . . . . . . . . . . . . 4 1.1. CDDL, CWT and JWT . . . . . . . . . . . . . . . . . . . . 4
1.2. Entity Overview . . . . . . . . . . . . . . . . . . . . . 4 1.2. Entity Overview . . . . . . . . . . . . . . . . . . . . . 4
1.3. EAT Operating Models . . . . . . . . . . . . . . . . . . 5 1.3. EAT Operating Models . . . . . . . . . . . . . . . . . . 5
1.4. What is Not Standardized . . . . . . . . . . . . . . . . 6 1.4. What is Not Standardized . . . . . . . . . . . . . . . . 6
1.4.1. Transmission Protocol . . . . . . . . . . . . . . . . 6 1.4.1. Transmission Protocol . . . . . . . . . . . . . . . . 6
1.4.2. Signing Scheme . . . . . . . . . . . . . . . . . . . 6 1.4.2. Signing Scheme . . . . . . . . . . . . . . . . . . . 7
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 7 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 7
3. The Claims Information Model . . . . . . . . . . . . . . . . 8 3. The Claims Information Model . . . . . . . . . . . . . . . . 8
3.1. Nonce Claim (cti and jti) . . . . . . . . . . . . . . . . 8 3.1. Token ID Claim (cti and jti) . . . . . . . . . . . . . . 8
3.2. Timestamp claim (iat) . . . . . . . . . . . . . . . . . . 8 3.2. Timestamp claim (iat) . . . . . . . . . . . . . . . . . . 8
3.3. Universal Entity ID Claim (ueid) . . . . . . . . . . . . 8 3.3. Nonce Claim (nonce) . . . . . . . . . . . . . . . . . . . 8
3.4. Origination Claim (origination) . . . . . . . . . . . . . 11 3.3.1. CDDL . . . . . . . . . . . . . . . . . . . . . . . . 9
3.4.1. CDDL . . . . . . . . . . . . . . . . . . . . . . . . 12 3.4. Universal Entity ID Claim (ueid) . . . . . . . . . . . . 9
3.5. OEM identification by IEEE OUI (oemid) . . . . . . . . . 12 3.4.1. CDDL . . . . . . . . . . . . . . . . . . . . . . . . 11
3.5. Origination Claim (origination) . . . . . . . . . . . . . 11
3.5.1. CDDL . . . . . . . . . . . . . . . . . . . . . . . . 12 3.5.1. CDDL . . . . . . . . . . . . . . . . . . . . . . . . 12
3.6. The Security Level Claim (security_level) . . . . . . . . 12 3.6. OEM Identification by IEEE (oemid) . . . . . . . . . . . 12
3.6.1. CDDL . . . . . . . . . . . . . . . . . . . . . . . . 13 3.6.1. CDDL . . . . . . . . . . . . . . . . . . . . . . . . 12
3.7. Secure Boot and Debug Enable State Claims (boot_state) . 13 3.7. The Security Level Claim (security_level) . . . . . . . . 12
3.7.1. Secure Boot Enabled . . . . . . . . . . . . . . . . . 13 3.7.1. CDDL . . . . . . . . . . . . . . . . . . . . . . . . 13
3.7.2. Debug Disabled . . . . . . . . . . . . . . . . . . . 13 3.8. Secure Boot and Debug Enable State Claims (boot_state) . 13
3.7.3. Debug Disabled Since Boot . . . . . . . . . . . . . . 14 3.8.1. Secure Boot Enabled . . . . . . . . . . . . . . . . . 14
3.7.4. Debug Permanent Disable . . . . . . . . . . . . . . . 14 3.8.2. Debug Disabled . . . . . . . . . . . . . . . . . . . 14
3.7.5. Debug Full Permanent Disable . . . . . . . . . . . . 14 3.8.3. Debug Disabled Since Boot . . . . . . . . . . . . . . 14
3.7.6. CDDL . . . . . . . . . . . . . . . . . . . . . . . . 14 3.8.4. Debug Permanent Disable . . . . . . . . . . . . . . . 14
3.8. The Location Claim (location) . . . . . . . . . . . . . . 14 3.8.5. Debug Full Permanent Disable . . . . . . . . . . . . 14
3.8.1. CDDL . . . . . . . . . . . . . . . . . . . . . . . . 15 3.8.6. CDDL . . . . . . . . . . . . . . . . . . . . . . . . 14
3.9. The Age Claim (age) . . . . . . . . . . . . . . . . . . . 15 3.9. The Location Claim (location) . . . . . . . . . . . . . . 15
3.10. The Uptime Claim (uptime) . . . . . . . . . . . . . . . . 15 3.9.1. CDDL . . . . . . . . . . . . . . . . . . . . . . . . 15
3.10.1. CDDL . . . . . . . . . . . . . . . . . . . . . . . . 15 3.10. The Age Claim (age) . . . . . . . . . . . . . . . . . . . 15
3.11. Nested EATs, the EAT Claim (nested_eat) . . . . . . . . . 15 3.11. The Uptime Claim (uptime) . . . . . . . . . . . . . . . . 15
3.11.1. CDDL . . . . . . . . . . . . . . . . . . . . . . . . 16 3.11.1. CDDL . . . . . . . . . . . . . . . . . . . . . . . . 15
3.12. The Submods Claim (submods) . . . . . . . . . . . . . . . 16 3.12. Nested EATs, the EAT Claim (nested_eat) . . . . . . . . . 16
3.12.1. The submod_name Claim . . . . . . . . . . . . . . . 16 3.12.1. CDDL . . . . . . . . . . . . . . . . . . . . . . . . 16
3.12.2. CDDL . . . . . . . . . . . . . . . . . . . . . . . . 16 3.13. The Submods Claim (submods) . . . . . . . . . . . . . . . 16
3.13.1. The submod_name Claim . . . . . . . . . . . . . . . 16
3.13.2. CDDL . . . . . . . . . . . . . . . . . . . . . . . . 17
4. Data Model . . . . . . . . . . . . . . . . . . . . . . . . . 17 4. Data Model . . . . . . . . . . . . . . . . . . . . . . . . . 17
4.1. Common CDDL Types . . . . . . . . . . . . . . . . . . . . 17 4.1. Common CDDL Types . . . . . . . . . . . . . . . . . . . . 17
4.2. CDDL for CWT-defined Claims . . . . . . . . . . . . . . . 17 4.2. CDDL for CWT-defined Claims . . . . . . . . . . . . . . . 17
4.3. JSON . . . . . . . . . . . . . . . . . . . . . . . . . . 18 4.3. JSON . . . . . . . . . . . . . . . . . . . . . . . . . . 18
4.3.1. JSON Labels . . . . . . . . . . . . . . . . . . . . . 18 4.3.1. JSON Labels . . . . . . . . . . . . . . . . . . . . . 18
4.3.2. JSON Interoperability . . . . . . . . . . . . . . . . 19 4.3.2. JSON Interoperability . . . . . . . . . . . . . . . . 19
4.4. CBOR . . . . . . . . . . . . . . . . . . . . . . . . . . 19 4.4. CBOR . . . . . . . . . . . . . . . . . . . . . . . . . . 19
4.4.1. Labels . . . . . . . . . . . . . . . . . . . . . . . 19 4.4.1. Labels . . . . . . . . . . . . . . . . . . . . . . . 19
4.4.2. CBOR Interoperability . . . . . . . . . . . . . . . . 20 4.4.2. CBOR Interoperability . . . . . . . . . . . . . . . . 20
4.5. Collected CDDL . . . . . . . . . . . . . . . . . . . . . 21 4.5. Collected CDDL . . . . . . . . . . . . . . . . . . . . . 21
5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 21 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 22
5.1. Reuse of CBOR Web Token (CWT) Claims Registry . . . . . . 21 5.1. Reuse of CBOR Web Token (CWT) Claims Registry . . . . . . 22
5.1.1. Claims Registered by This Document . . . . . . . . . 22 5.1.1. Claims Registered by This Document . . . . . . . . . 22
6. Privacy Considerations . . . . . . . . . . . . . . . . . . . 22 6. Privacy Considerations . . . . . . . . . . . . . . . . . . . 23
6.1. UEID Privacy Considerations . . . . . . . . . . . . . . . 22 6.1. UEID Privacy Considerations . . . . . . . . . . . . . . . 23
7. Security Considerations . . . . . . . . . . . . . . . . . . . 23 7. Security Considerations . . . . . . . . . . . . . . . . . . . 24
8. References . . . . . . . . . . . . . . . . . . . . . . . . . 23 8. References . . . . . . . . . . . . . . . . . . . . . . . . . 24
8.1. Normative References . . . . . . . . . . . . . . . . . . 23 8.1. Normative References . . . . . . . . . . . . . . . . . . 24
8.2. Informative References . . . . . . . . . . . . . . . . . 24 8.2. Informative References . . . . . . . . . . . . . . . . . 25
Appendix A. Examples . . . . . . . . . . . . . . . . . . . . . . 26 Appendix A. Examples . . . . . . . . . . . . . . . . . . . . . . 27
A.1. Very Simple EAT . . . . . . . . . . . . . . . . . . . . . 26 A.1. Very Simple EAT . . . . . . . . . . . . . . . . . . . . . 27
A.2. Example with Submodules, Nesting and Security Levels . . 26 A.2. Example with Submodules, Nesting and Security Levels . . 27
Appendix B. Changes from Previous Drafts . . . . . . . . . . . . 27 Appendix B. Changes from Previous Drafts . . . . . . . . . . . . 28
B.1. From draft-mandyam-rats-eat-00 . . . . . . . . . . . . . 27 B.1. From draft-mandyam-rats-eat-00 . . . . . . . . . . . . . 28
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 27 B.2. From draft-ietf-rats-eat-01 . . . . . . . . . . . . . . . 28
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 28
1. Introduction 1. Introduction
Remote device attestation is a fundamental service that allows a Remote device attestation is a fundamental service that allows a
remote device such as a mobile phone, an Internet-of-Things (IoT) remote device such as a mobile phone, an Internet-of-Things (IoT)
device, or other endpoint to prove itself to a relying party, a device, or other endpoint to prove itself to a relying party, a
server or a service. This allows the relying party to know some server or a service. This allows the relying party to know some
characteristics about the device and decide whether it trusts the characteristics about the device and decide whether it trusts the
device. device.
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Attestation Key Material (AKM). The key material used to sign the Attestation Key Material (AKM). The key material used to sign the
EAT token. If it is done symmetrically with HMAC, then this is a EAT token. If it is done symmetrically with HMAC, then this is a
simple symmetric key. If it is done with ECC, such as an IEEE simple symmetric key. If it is done with ECC, such as an IEEE
DevID [IDevID], then this is the private part of the EC key pair. DevID [IDevID], then this is the private part of the EC key pair.
If ECDAA is used, (e.g., as used by Enhanced Privacy ID, i.e. If ECDAA is used, (e.g., as used by Enhanced Privacy ID, i.e.
EPID) then it is the key material needed for ECDAA. EPID) then it is the key material needed for ECDAA.
3. The Claims Information Model 3. The Claims Information Model
This section describes new claims defined for attestation. It also This section describes new claims defined for attestation. It also
mentions several claims defined by CWT and JWT are particularly mentions several claims defined by CWT and JWT that are particularly
important for EAT. important for EAT.
Note also: * Any claim defined for CWT or JWT may be used in an EAT Note also: * Any claim defined for CWT or JWT may be used in an EAT
including those in the CWT [IANA.CWT.Claims] and JWT IANA including those in the CWT [IANA.CWT.Claims] and JWT IANA
[IANA.JWT.Claims] claims registries. * All claims are optional * No [IANA.JWT.Claims] claims registries.
claims are mandatory * All claims that are not understood by
implementations MUST be ignored o All claims are optional
o No claims are mandatory
o All claims that are not understood by implementations MUST be
ignored
CDDL along with text descriptions is used to define the information CDDL along with text descriptions is used to define the information
model. Each claim is defined as a CDDL group (the group is a general model. Each claim is defined as a CDDL group (the group is a general
aggregation and type definition feature of CDDL). In the data model, aggregation and type definition feature of CDDL). In the data model,
described in the Section 4, the CDDL groups turn into CBOR map described in the Section 4, the CDDL groups turn into CBOR map
entries and JSON name/value pairs. entries and JSON name/value pairs.
3.1. Nonce Claim (cti and jti) 3.1. Token ID Claim (cti and jti)
All EATs should have a nonce to prevent replay attacks. The nonce is
generated by the relying party, sent to the entity by any protocol,
and included in the token. Note that intrinsically by the nature of
a nonce no security is needed for its transport.
CWT defines the "cti" claim. JWT defines the "jti" claim. These
carry the nonce in an EAT.
TODO: what about the JWT claim "nonce"? CWT defines the "cti" claim. JWT defines the "jti" claim. These are
equivalent to each other in EAT and carry a unique token identifier
as they do in JWT and CWT. They may be used to defend against re use
of the token but are distinct from the nonce that is used by the
relying party to guarantee freshness and defend against replay.
3.2. Timestamp claim (iat) 3.2. Timestamp claim (iat)
The "iat" claim defined in CWT and JWT is used to indicate the date- The "iat" claim defined in CWT and JWT is used to indicate the date-
of-creation of the token. of-creation of the token.
3.3. Universal Entity ID Claim (ueid) 3.3. Nonce Claim (nonce)
All EATs should have a nonce to prevent replay attacks. The nonce is
generated by the relying party, the end consumer of the token. It is
conveyed to the entity over whatever transport is in use before the
token is generated and then included in the token as the nonce claim.
This documents the nonce claim for registration in the IANA CWT
claims registry. This is equivalent to the JWT nonce claim that is
already registered.
The nonce must be at least 8 bytes (64 bits) as fewer are unlikely to
be secure. A maximum of 64 bytes is set to limit the memory a
constrained implementation uses. This size range is not set for the
already-registered JWT nonce, but it should follow this size
recommendation when used in an EAT.
3.3.1. CDDL
nonce_claim = (
nonce => bstr .size (8..64)
)
3.4. Universal Entity ID Claim (ueid)
UEID's identify individual manufactured entities / devices such as a UEID's identify individual manufactured entities / devices such as a
mobile phone, a water meter, a Bluetooth speaker or a networked mobile phone, a water meter, a Bluetooth speaker or a networked
security camera. It may identify the entire device or a submodule or security camera. It may identify the entire device or a submodule or
subsystem. It does not identify types, models or classes of devices. subsystem. It does not identify types, models or classes of devices.
It is akin to a serial number, though it does not have to be It is akin to a serial number, though it does not have to be
sequential. sequential.
UEID's must be universally and globally unique across manufacturers UEID's must be universally and globally unique across manufacturers
and countries. UEIDs must also be unique across protocols and and countries. UEIDs must also be unique across protocols and
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o New types of UEIDs may be created. For example, a type 0x07 UEID o New types of UEIDs may be created. For example, a type 0x07 UEID
may be created based on some other manufacturer registration may be created based on some other manufacturer registration
scheme. scheme.
o Device manufacturers are allowed to change from one type of UEID o Device manufacturers are allowed to change from one type of UEID
to another anytime they want. For example, they may find they can to another anytime they want. For example, they may find they can
optimize their manufacturing by switching from type 0x01 to type optimize their manufacturing by switching from type 0x01 to type
0x02 or vice versa. The main requirement on the manufacturer is 0x02 or vice versa. The main requirement on the manufacturer is
that UEIDs be universally unique. that UEIDs be universally unique.
### CDDL 3.4.1. CDDL
ueid_claim = ( ueid_claim = (
ueid: bstr ) ueid: bstr )
3.4. Origination Claim (origination) 3.5. Origination Claim (origination)
This claim describes the parts of the device or entity that are This claim describes the parts of the device or entity that are
creating the EAT. Often it will be tied back to the device or chip creating the EAT. Often it will be tied back to the device or chip
manufacturer. The following table gives some examples: manufacturer. The following table gives some examples:
+-------------------+-----------------------------------------------+ +-------------------+-----------------------------------------------+
| Name | Description | | Name | Description |
+-------------------+-----------------------------------------------+ +-------------------+-----------------------------------------------+
| Acme-TEE | The EATs are generated in the TEE authored | | Acme-TEE | The EATs are generated in the TEE authored |
| | and configured by "Acme" | | | and configured by "Acme" |
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| Acme-TA | The EATs are generated in a Trusted | | Acme-TA | The EATs are generated in a Trusted |
| | Application (TA) authored by "Acme" | | | Application (TA) authored by "Acme" |
+-------------------+-----------------------------------------------+ +-------------------+-----------------------------------------------+
TODO: consider a more structure approach where the name and the URI TODO: consider a more structure approach where the name and the URI
and other are in separate fields. and other are in separate fields.
TODO: This needs refinement. It is somewhat parallel to issuer claim TODO: This needs refinement. It is somewhat parallel to issuer claim
in CWT in that it describes the authority that created the token. in CWT in that it describes the authority that created the token.
3.4.1. CDDL 3.5.1. CDDL
origination_claim = ( origination_claim = (
origination: string_or_uri ) origination: string_or_uri )
3.5. OEM identification by IEEE OUI (oemid) 3.6. OEM Identification by IEEE (oemid)
This claim identifies a device OEM by the IEEE OUI. Reference TBD. The IEEE operates a global registry for MAC addresses and company
It is a byte string representing the OUI in binary form in network IDs. This claim uses that database to identify OEMs. The contents
byte order (TODO: confirm details). of the claim may be either an IEEE MA-L, MA-M, MA-S or an IEEE CID
[IEEE.RA]. An MA-L, formerly known as an OUI, is a 24-bit value used
as the first half of a MAC address. MA-M similarly is a 28-bit value
uses as the first part of a MAC address, and MA-S, formerly known as
OUI-36, a 36-bit value. Many companies already have purchased one of
these. A CID is also a 24-bit value from the same space as an MA-L,
but not for use as a MAC address. IEEE has published Guidelines for
Use of EUI, OUI, and CID [OUI.Guide] and provides a lookup services
[OUI.Lookup]
Companies that have more than one IEEE OUI registered with IEEE Companies that have more than one of these IDs or MAC address blocks
should pick one and prefer that for all their devices. should pick one and prefer that for all their devices.
Note that the OUI is in common use as a part of MAC Address. This Commonly, these are expressed in Hexadecimal Representation
claim is only the first bits of the MAC address that identify the [IEEE.802-2001] also called the Canonical format. When this claim is
manufacturer. The IEEE maintains a registry for these in which many encoded order of bytes in the bstr are the same as the order in the
companies participate. Hexadecimal Representation. For example, an MA-L like "AC-DE-48"
would be encoded in 3 bytes with values 0xAC, 0xDE, 0x48. For JSON
encoded tokens, this is further base64url encoded.
3.5.1. CDDL 3.6.1. CDDL
oemid_claim = ( oemid_claim = (
oemid: bstr ) oemid: bstr )
3.6. The Security Level Claim (security_level) 3.7. The Security Level Claim (security_level)
EATs have a claim that roughly characterizes the device / entities EATs have a claim that roughly characterizes the device / entities
ability to defend against attacks aimed at capturing the signing key, ability to defend against attacks aimed at capturing the signing key,
forging claims and at forging EATs. This is done by roughly defining forging claims and at forging EATs. This is done by roughly defining
four security levels as described below. This is similar to the four security levels as described below. This is similar to the
security levels defined in the Metadata Service defined by the Fast security levels defined in the Metadata Service defined by the Fast
Identity Online (FIDO) Alliance (TODO: reference). Identity Online (FIDO) Alliance (TODO: reference).
These claims describe security environment and countermeasures These claims describe security environment and countermeasures
available on the end-entity / client device where the attestation key available on the end-entity / client device where the attestation key
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4 - Hardware Entities at this level must include substantial defense 4 - Hardware Entities at this level must include substantial defense
against physical or electrical attacks against the device itself. against physical or electrical attacks against the device itself.
It is assumed any potential attacker has captured the device and It is assumed any potential attacker has captured the device and
can disassemble it. Example include TPMs and Secure Elements. can disassemble it. Example include TPMs and Secure Elements.
This claim is not intended as a replacement for a proper end-device This claim is not intended as a replacement for a proper end-device
security certification schemes such as those based on FIPS (TODO: security certification schemes such as those based on FIPS (TODO:
reference) or those based on Common Criteria (TODO: reference). The reference) or those based on Common Criteria (TODO: reference). The
claim made here is solely a self-claim made by the Entity Originator. claim made here is solely a self-claim made by the Entity Originator.
3.6.1. CDDL 3.7.1. CDDL
security_level_type = ( security_level_type = (
unrestricted: 1, unrestricted: 1,
restricted: 2, restricted: 2,
secure_restricted: 3, secure_restricted: 3,
hardware: 4 hardware: 4
) )
security_level_claim = ( security_level_claim = (
security_level: security_level_type ) security_level: security_level_type )
3.7. Secure Boot and Debug Enable State Claims (boot_state) 3.8. Secure Boot and Debug Enable State Claims (boot_state)
This claim is an array of five Boolean values indicating the boot and This claim is an array of five Boolean values indicating the boot and
debug state of the entity. debug state of the entity.
3.7.1. Secure Boot Enabled 3.8.1. Secure Boot Enabled
This indicates whether secure boot is enabled either for an entire This indicates whether secure boot is enabled either for an entire
device or an individual submodule. If it appears at the device device or an individual submodule. If it appears at the device
level, then this means that secure boot is enabled for all level, then this means that secure boot is enabled for all
submodules. Secure boot enablement allows a secure boot loader to submodules. Secure boot enablement allows a secure boot loader to
authenticate software running either in a device or a submodule prior authenticate software running either in a device or a submodule prior
allowing execution. allowing execution.
3.7.2. Debug Disabled 3.8.2. Debug Disabled
This indicates whether debug capabilities are disabled for an entity This indicates whether debug capabilities are disabled for an entity
(i.e. value of 'true'). Debug disablement is considered a (i.e. value of 'true'). Debug disablement is considered a
prerequisite before an entity is considered operational. prerequisite before an entity is considered operational.
3.7.3. Debug Disabled Since Boot 3.8.3. Debug Disabled Since Boot
This claim indicates whether debug capabilities for the entity were This claim indicates whether debug capabilities for the entity were
not disabled in any way since boot (i.e. value of 'true'). not disabled in any way since boot (i.e. value of 'true').
3.7.4. Debug Permanent Disable 3.8.4. Debug Permanent Disable
This claim indicates whether debug capabilities for the entity are This claim indicates whether debug capabilities for the entity are
permanently disabled (i.e. value of 'true'). This value can be set permanently disabled (i.e. value of 'true'). This value can be set
to 'true' also if only the manufacturer is allowed to enabled debug, to 'true' also if only the manufacturer is allowed to enabled debug,
but the end user is not. but the end user is not.
3.7.5. Debug Full Permanent Disable 3.8.5. Debug Full Permanent Disable
This claim indicates whether debug capabilities for the entity are This claim indicates whether debug capabilities for the entity are
permanently disabled (i.e. value of 'true'). This value can only be permanently disabled (i.e. value of 'true'). This value can only be
set to 'true' if no party can enable debug capabilities for the set to 'true' if no party can enable debug capabilities for the
entity. Often this is implemented by blowing a fuse on a chip as entity. Often this is implemented by blowing a fuse on a chip as
fuses cannot be restored once blown. fuses cannot be restored once blown.
3.7.6. CDDL 3.8.6. CDDL
boot_state_type = [ boot_state_type = [
secure_boot_enabled=> bool, secure_boot_enabled=> bool,
debug_disabled=> bool, debug_disabled=> bool,
debug_disabled_since_boot=> bool, debug_disabled_since_boot=> bool,
debug_permanent_disable=> bool, debug_permanent_disable=> bool,
debug_full_permanent_disable=> bool debug_full_permanent_disable=> bool
] ]
boot_state_claim = ( boot_state_claim = (
boot_state: boot_state_type boot_state: boot_state_type
) )
3.8. The Location Claim (location) 3.9. The Location Claim (location)
The location claim is a CBOR-formatted object that describes the The location claim is a CBOR-formatted object that describes the
location of the device entity from which the attestation originates. location of the device entity from which the attestation originates.
It is comprised of a map of additional sub claims that represent the It is comprised of a map of additional sub claims that represent the
actual location coordinates (latitude, longitude and altitude). The actual location coordinates (latitude, longitude and altitude). The
location coordinate claims are consistent with the WGS84 coordinate location coordinate claims are consistent with the WGS84 coordinate
system [WGS84]. In addition, a sub claim providing the estimated system [WGS84]. In addition, a sub claim providing the estimated
accuracy of the location measurement is defined. accuracy of the location measurement is defined.
3.8.1. CDDL 3.9.1. CDDL
location_type = { location_type = {
latitude => number, latitude => number,
longitude => number, longitude => number,
altitude => number, altitude => number,
accuracy => number, accuracy => number,
altitude_accuracy => number, altitude_accuracy => number,
heading_claim => number, heading => number,
speed_claim => number speed => number
} }
location_claim = ( location_claim = (
location: location_type ) location: location_type )
3.9. The Age Claim (age) 3.10. The Age Claim (age)
The "age" claim contains a value that represents the number of The "age" claim contains a value that represents the number of
seconds that have elapsed since the token was created, measurement seconds that have elapsed since the token was created, measurement
was made, or location was obtained. Typical attestable values are was made, or location was obtained. Typical attestable values are
sent as soon as they are obtained. However, in the case that such a sent as soon as they are obtained. However, in the case that such a
value is buffered and sent at a later time and a sufficiently value is buffered and sent at a later time and a sufficiently
accurate time reference is unavailable for creation of a timestamp, accurate time reference is unavailable for creation of a timestamp,
then the age claim is provided. then the age claim is provided.
age_claim = ( age_claim = (
age: uint) age: uint)
3.10. The Uptime Claim (uptime) 3.11. The Uptime Claim (uptime)
The "uptime" claim contains a value that represents the number of The "uptime" claim contains a value that represents the number of
seconds that have elapsed since the entity or submod was last booted. seconds that have elapsed since the entity or submod was last booted.
3.10.1. CDDL 3.11.1. CDDL
uptime_claim = ( uptime_claim = (
uptime: uint ) uptime: uint )
3.11. Nested EATs, the EAT Claim (nested_eat) 3.12. Nested EATs, the EAT Claim (nested_eat)
It is allowed for one EAT to be embedded in another. This is for It is allowed for one EAT to be embedded in another. This is for
complex devices that have more than one subsystem capable of complex devices that have more than one subsystem capable of
generating an EAT. Typically, one will be the device-wide EAT that generating an EAT. For example, one might be the device-wide EAT
is low to medium security and another from a Secure Element or that is low to medium security and another from a Secure Element or
similar that is high security. similar that is high security.
The contents of the "eat" claim must be a fully signed, optionally The contents of the "nested_eat" claim must be a fully signed,
encrypted, EAT token. optionally encrypted, EAT token.
3.11.1. CDDL 3.12.1. CDDL
nested_eat_claim = ( nested_eat_claim = (
nested_eat: nested_eat_type) nested_eat: nested_eat_type)
A nested_eat_type is defined in words rather than CDDL. It is either A nested_eat_type is defined in words rather than CDDL. It is either
a full CWT or JWT including the COSE or JOSE signing. a full CWT or JWT including the COSE or JOSE signing.
3.12. The Submods Claim (submods) 3.13. The Submods Claim (submods)
Some devices are complex, having many subsystems or submodules. A Some devices are complex, having many subsystems or submodules. A
mobile phone is a good example. It may have several connectivity mobile phone is a good example. It may have several connectivity
submodules for communications (e.g., Wi-Fi and cellular). It may submodules for communications (e.g., Wi-Fi and cellular). It may
have subsystems for low-power audio and video playback. It may have have subsystems for low-power audio and video playback. It may have
one or more security-oriented subsystems like a TEE or a Secure one or more security-oriented subsystems like a TEE or a Secure
Element. Element.
The claims for each these can be grouped together in a submodule. The claims for each these can be grouped together in a submodule.
Specifically, the "submods" claim is an array. Each item in the Specifically, the "submods" claim is an array. Each item in the
array is a CBOR map containing all the claims for a particular array is a CBOR map containing all the claims for a particular
submodule. submodule.
The security level of the submod is assumed to be at the same level The security level of the submod is assumed to be at the same level
as the main entity unless there is a security level claim in that as the main entity unless there is a security level claim in that
submodule indicating otherwise. The security level of a submodule submodule indicating otherwise. The security level of a submodule
can never be higher (more secure) than the security level of the EAT can never be higher (more secure) than the security level of the EAT
it is a part of. it is a part of.
3.12.1. The submod_name Claim 3.13.1. The submod_name Claim
Each submodule should have a submod_name claim that is descriptive Each submodule should have a submod_name claim that is descriptive
name. This name should be the CBOR txt type. name. This name should be the CBOR txt type.
3.12.2. CDDL 3.13.2. CDDL
In the following a generic_claim_type is any CBOR map entry or JSON In the following a generic_claim_type is any CBOR map entry or JSON
name/value pair. name/value pair.
submod_name_type = ( submod_name_type = (
submod_name: tstr ) submod_name: tstr )
submods_type = [ * submod_claims ] submods_type = [ * submod_claims ]
submod_claims = { submod_claims = {
skipping to change at page 19, line 15 skipping to change at page 19, line 15
origination = "origination" origination = "origination"
oemid = "oemid" oemid = "oemid"
security_level = "security_level" security_level = "security_level"
boot_state = "boot_state" boot_state = "boot_state"
location = "location" location = "location"
age = "age" age = "age"
uptime = "uptime" uptime = "uptime"
nested_eat = "nested_eat" nested_eat = "nested_eat"
submods = "submods" submods = "submods"
latitude = "lat""
longitude = "long""
altitude = "alt"
accuracy = "accry"
altitude_accuracy = "alt_accry"
heading = "heading"
speed = "speed"
4.3.2. JSON Interoperability 4.3.2. JSON Interoperability
JSON should be encoded per RFC 8610 Appendix E. In addition, the JSON should be encoded per RFC 8610 Appendix E. In addition, the
following CDDL types are encoded in JSON as follows: following CDDL types are encoded in JSON as follows:
o bstr - must be base64url encoded o bstr - must be base64url encoded
o time - must be encoded as NumericDate as described section 2 of o time - must be encoded as NumericDate as described section 2 of
[RFC7519]. [RFC7519].
skipping to change at page 19, line 43 skipping to change at page 20, line 15
origination = 9 origination = 9
oemid = 10 oemid = 10
security_level = 11 security_level = 11
boot_state = 12 boot_state = 12
location = 13 location = 13
age = 14 age = 14
uptime = 15 uptime = 15
nested_eat = 16 nested_eat = 16
submods = 17 submods = 17
submod_name = 18 submod_name = 18
nonce = 19
latitude 1 latitude = 1
longitude 2 longitude = 2
altitude 3 altitude = 3
accuracy 4 accuracy = 4
altitude_accuracy 5 altitude_accuracy = 5
heading_claim 6 heading = 6
speed_claim 7 speed = 7
4.4.2. CBOR Interoperability 4.4.2. CBOR Interoperability
Variations in the CBOR serializations supported in CBOR encoding and Variations in the CBOR serializations supported in CBOR encoding and
decoding are allowed and suggests that CBOR-based protocols specify decoding are allowed and suggests that CBOR-based protocols specify
how this variation is handled. This section specifies what formats how this variation is handled. This section specifies what formats
MUST be supported in order to achieve interoperability. MUST be supported in order to achieve interoperability.
The assumption is that the entity is likely to be a constrained The assumption is that the entity is likely to be a constrained
device and relying party is likely to be a very capable server. The device and relying party is likely to be a very capable server. The
skipping to change at page 22, line 39 skipping to change at page 23, line 21
provided to unauthenticated consumers. provided to unauthenticated consumers.
6.1. UEID Privacy Considerations 6.1. UEID Privacy Considerations
A UEID is usually not privacy-preserving. Any set of relying parties A UEID is usually not privacy-preserving. Any set of relying parties
that receives tokens that happen to be from a single device will be that receives tokens that happen to be from a single device will be
able to know the tokens are all from the same device and be able to able to know the tokens are all from the same device and be able to
track the device. Thus, in many usage situations ueid violates track the device. Thus, in many usage situations ueid violates
governmental privacy regulation. In other usage situations UEID will governmental privacy regulation. In other usage situations UEID will
not be allowed for certain products like browsers that give privacy not be allowed for certain products like browsers that give privacy
for the end user. it will often be the case that tokens will not for the end user. It will often be the case that tokens will not
have a UEID for these reasons. have a UEID for these reasons.
There are several strategies that can be used to still be able to put There are several strategies that can be used to still be able to put
UEID's in tokens: UEID's in tokens:
o The device obtains explicit permission from the user of the device o The device obtains explicit permission from the user of the device
to use the UEID. This may be through a prompt. It may also be to use the UEID. This may be through a prompt. It may also be
through a license agreement. For example, agreements for some through a license agreement. For example, agreements for some
online banking and brokerage services might already cover use of a online banking and brokerage services might already cover use of a
UEID. UEID.
skipping to change at page 23, line 29 skipping to change at page 24, line 16
TODO: Perhaps this can be the same as CWT / COSE, but not sure yet TODO: Perhaps this can be the same as CWT / COSE, but not sure yet
because it involves so much entity / device security that those do because it involves so much entity / device security that those do
not. not.
8. References 8. References
8.1. Normative References 8.1. Normative References
[IANA.CWT.Claims] [IANA.CWT.Claims]
IANA, "CBOR Web Token (CWT) Claims", n.d., IANA, "CBOR Web Token (CWT) Claims",
<http://www.iana.org/assignments/cwt>. <http://www.iana.org/assignments/cwt>.
[IANA.JWT.Claims] [IANA.JWT.Claims]
IANA, "JSON Web Token (JWT) Claims", n.d., IANA, "JSON Web Token (JWT) Claims",
<https://www.iana.org/assignments/jwt>. <https://www.iana.org/assignments/jwt>.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997, DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/info/rfc2119>. <https://www.rfc-editor.org/info/rfc2119>.
[RFC7049] Bormann, C. and P. Hoffman, "Concise Binary Object [RFC7049] Bormann, C. and P. Hoffman, "Concise Binary Object
Representation (CBOR)", RFC 7049, DOI 10.17487/RFC7049, Representation (CBOR)", RFC 7049, DOI 10.17487/RFC7049,
October 2013, <https://www.rfc-editor.org/info/rfc7049>. October 2013, <https://www.rfc-editor.org/info/rfc7049>.
skipping to change at page 24, line 45 skipping to change at page 25, line 33
[ASN.1] International Telecommunication Union, "Information [ASN.1] International Telecommunication Union, "Information
Technology -- ASN.1 encoding rules: Specification of Basic Technology -- ASN.1 encoding rules: Specification of Basic
Encoding Rules (BER), Canonical Encoding Rules (CER) and Encoding Rules (BER), Canonical Encoding Rules (CER) and
Distinguished Encoding Rules (DER)", ITU-T Recommendation Distinguished Encoding Rules (DER)", ITU-T Recommendation
X.690, 1994. X.690, 1994.
[ECMAScript] [ECMAScript]
"Ecma International, "ECMAScript Language Specification, "Ecma International, "ECMAScript Language Specification,
5.1 Edition", ECMA Standard 262", June 2011, 5.1 Edition", ECMA Standard 262", June 2011,
<http://www.ecma-international.org/ecma-262/5.1/ <http://www.ecma-international.org/ecma-262/5.1/ECMA-
ECMA-262.pdf>. 262.pdf>.
[IDevID] "IEEE Standard, "IEEE 802.1AR Secure Device Identifier"", [IDevID] "IEEE Standard, "IEEE 802.1AR Secure Device Identifier"",
December 2009, <http://standards.ieee.org/findstds/ December 2009, <http://standards.ieee.org/findstds/
standard/802.1AR-2009.html>. standard/802.1AR-2009.html>.
[IEEE.802-2001]
"IEEE Standard For Local And Metropolitan Area Networks
Overview And Architecture", 2007,
<https://webstore.ansi.org/standards/ieee/
ieee8022001r2007>.
[IEEE.RA] "IEEE Registration Authority",
<https://standards.ieee.org/products-services/regauth/
index.html>.
[OUI.Guide]
"Guidelines for Use of Extended Unique Identifier (EUI),
Organizationally Unique Identifier (OUI), and Company ID
(CID)", August 2017,
<https://standards.ieee.org/content/dam/ieee-
standards/standards/web/documents/tutorials/eui.pdf>.
[OUI.Lookup]
"IEEE Registration Authority Assignments",
<https://regauth.standards.ieee.org/standards-ra-web/pub/
view.html#registries>.
[Webauthn] [Webauthn]
Worldwide Web Consortium, "Web Authentication: A Web API Worldwide Web Consortium, "Web Authentication: A Web API
for accessing scoped credentials", 2016. for accessing scoped credentials", 2016.
Appendix A. Examples Appendix A. Examples
A.1. Very Simple EAT A.1. Very Simple EAT
This is shown in CBOR diagnostic form. Only the payload signed by This is shown in CBOR diagnostic form. Only the payload signed by
COSE is shown. COSE is shown.
skipping to change at page 27, line 21 skipping to change at page 28, line 21
This is a fairly large change in the orientation of the document, but This is a fairly large change in the orientation of the document, but
not new claims have been added. not new claims have been added.
o Separate information and data model using CDDL. o Separate information and data model using CDDL.
o Say an EAT is a CWT or JWT o Say an EAT is a CWT or JWT
o Use a map to structure the boot_state and location claims o Use a map to structure the boot_state and location claims
B.2. From draft-ietf-rats-eat-01
o Clarifications and corrections for OEMID claim
o Minor spelling and other fixes
o Add the nonce claim, clarify jti claim
Authors' Addresses Authors' Addresses
Giridhar Mandyam Giridhar Mandyam
Qualcomm Technologies Inc. Qualcomm Technologies Inc.
5775 Morehouse Drive 5775 Morehouse Drive
San Diego, California San Diego, California
USA USA
Phone: +1 858 651 7200 Phone: +1 858 651 7200
EMail: mandyam@qti.qualcomm.com EMail: mandyam@qti.qualcomm.com
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