draft-ietf-rats-uccs-00.txt   draft-ietf-rats-uccs-01.txt 
RATS Working Group H. Birkholz RATS Working Group H. Birkholz
Internet-Draft Fraunhofer SIT Internet-Draft Fraunhofer SIT
Intended status: Standards Track J. O'Donoghue Intended status: Standards Track J. O'Donoghue
Expires: 20 November 2021 Qualcomm Technologies Inc. Expires: 14 January 2022 Qualcomm Technologies Inc.
N. Cam-Winget N. Cam-Winget
Cisco Systems Cisco Systems
C. Bormann C. Bormann
Universitaet Bremen TZI Universität Bremen TZI
19 May 2021 13 July 2021
A CBOR Tag for Unprotected CWT Claims Sets A CBOR Tag for Unprotected CWT Claims Sets
draft-ietf-rats-uccs-00 draft-ietf-rats-uccs-01
Abstract Abstract
CBOR Web Token (CWT, RFC 8392) Claims Sets sometimes do not need the CBOR Web Token (CWT, RFC 8392) Claims Sets sometimes do not need the
protection afforded by wrapping them into COSE, as is required for a protection afforded by wrapping them into COSE, as is required for a
true CWT. This specification defines a CBOR tag for such unprotected true CWT. This specification defines a CBOR tag for such unprotected
CWT Claims Sets (UCCS) and discusses conditions for its proper use. CWT Claims Sets (UCCS) and discusses conditions for its proper use.
Discussion Venues
This note is to be removed before publishing as an RFC.
Discussion of this document takes place on the mailing list
(rats@ietf.org), which is archived at
https://mailarchive.ietf.org/arch/browse/rats/.
Source for this draft and an issue tracker can be found at
https://github.com/ietf-rats-wg/draft-ietf-rats-uccs.
Status of This Memo Status of This Memo
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Copyright Notice Copyright Notice
Copyright (c) 2021 IETF Trust and the persons identified as the Copyright (c) 2021 IETF Trust and the persons identified as the
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Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 3 1.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 3
2. Motivation and Requirements . . . . . . . . . . . . . . . . . 4 2. Example Use Cases . . . . . . . . . . . . . . . . . . . . . . 4
3. Characteristics of a Secure Channel . . . . . . . . . . . . . 4 3. Characteristics of a Secure Channel . . . . . . . . . . . . . 4
3.1. UCCS and Remote ATtestation procedureS (RATS) . . . . . . 5 3.1. UCCS and Remote ATtestation procedureS (RATS) . . . . . . 5
3.2. Privacy Preserving Channels . . . . . . . . . . . . . . . 6 3.2. Privacy Preserving Channels . . . . . . . . . . . . . . . 6
4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 6 4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 6
5. Security Considerations . . . . . . . . . . . . . . . . . . . 6 5. Security Considerations . . . . . . . . . . . . . . . . . . . 7
5.1. General Considerations . . . . . . . . . . . . . . . . . 7 5.1. General Considerations . . . . . . . . . . . . . . . . . 7
5.2. AES-CBC_MAC . . . . . . . . . . . . . . . . . . . . . . . 7 5.2. AES-CBC_MAC . . . . . . . . . . . . . . . . . . . . . . . 8
5.3. AES-GCM . . . . . . . . . . . . . . . . . . . . . . . . . 8 5.3. AES-GCM . . . . . . . . . . . . . . . . . . . . . . . . . 8
5.4. AES-CCM . . . . . . . . . . . . . . . . . . . . . . . . . 8 5.4. AES-CCM . . . . . . . . . . . . . . . . . . . . . . . . . 8
5.5. ChaCha20 and Poly1305 . . . . . . . . . . . . . . . . . . 8 5.5. ChaCha20 and Poly1305 . . . . . . . . . . . . . . . . . . 8
6. References . . . . . . . . . . . . . . . . . . . . . . . . . 8 6. References . . . . . . . . . . . . . . . . . . . . . . . . . 9
6.1. Normative References . . . . . . . . . . . . . . . . . . 8 6.1. Normative References . . . . . . . . . . . . . . . . . . 9
6.2. Informative References . . . . . . . . . . . . . . . . . 9 6.2. Informative References . . . . . . . . . . . . . . . . . 9
Appendix A. Example . . . . . . . . . . . . . . . . . . . . . . 10 Appendix A. Example . . . . . . . . . . . . . . . . . . . . . . 10
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 10 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 11
1. Introduction 1. Introduction
A CBOR Web Token (CWT) as specified by [RFC8392] is always wrapped in A CBOR Web Token (CWT) as specified by [RFC8392] is always wrapped in
a CBOR Object Signing and Encryption (COSE, [RFC8152]) envelope. a CBOR Object Signing and Encryption (COSE, [RFC8152]) envelope.
COSE provides -- amongst other things -- the integrity protection COSE provides -- amongst other things -- the end-to-end data origin
mandated by RFC 8392 and optional encryption for CWTs. Under the authentication and integrity protection employed by RFC 8392 and
right circumstances, though, a signature providing proof for optional encryption for CWTs. Under the right circumstances
authenticity and integrity can be provided through the transfer (Section 3), though, a signature providing proof for authenticity and
protocol and thus omitted from the information in a CWT without integrity can be provided through the transfer protocol and thus
compromising the intended goal of authenticity and integrity. If a omitted from the information in a CWT without compromising the
mutually Secured Channel is established between two remote peers, and intended goal of authenticity and integrity. In other words, if
if that Secure Channel provides the required properties (as discussed communicating parties have a pre-existing security association they
below), it is possible to omit the protection provided by COSE, can reuse it to provide authenticity and integrity for their
creating a use case for unprotected CWT Claims Sets. Similarly, if messages, enabling the basic principle of using resources
there is one-way authentication, the party that did not authenticate parsimoniously. Specifically, if a mutually Secured Channel is
may be in a position to send authentication information through this established between two remote peers, and if that Secure Channel
channel that allows the already authenticated party to authenticate provides the required properties (as discussed below), it is possible
the other party. to omit the protection provided by COSE, creating a use case for
unprotected CWT Claims Sets. Similarly, if there is one-way
authentication, the party that did not authenticate may be in a
position to send authentication information through this channel that
allows the already authenticated party to authenticate the other
party.
This specification allocates a CBOR tag to mark Unprotected CWT This specification allocates a CBOR tag to mark Unprotected CWT
Claims Sets (UCCS) as such and discusses conditions for its proper Claims Sets (UCCS) as such and discusses conditions for its proper
use in the scope of Remote ATtestation procedureS (RATS) and the use in the scope of Remote ATtestation procedureS (RATS) and the
conveyance of Evidence from an Attester to a Verifier. conveyance of Evidence from an Attester to a Verifier.
This specification does not change [RFC8392]: A true CWT does not This specification does not change [RFC8392]: A true CWT does not
make use of the tag allocated here; the UCCS tag is an alternative to make use of the tag allocated here; the UCCS tag is an alternative to
using COSE protection and a CWT tag. Consequently, in a well-defined using COSE protection and a CWT tag. Consequently, within the well-
scope, it might be acceptable to use the contents of a CWT without defined scope of a secured channel, it can be acceptable and economic
its COSE container and tag it with a UCCS CBOR tag for further to use the contents of a CWT without its COSE container and tag it
processing -- or to use the contents of a UCCS CBOR tag for building with a UCCS CBOR tag for further processing within that scope -- or
a CWT to be signed by some entity that can vouch for those contents. to use the contents of a UCCS CBOR tag for building a CWT to be
signed by some entity that can vouch for those contents.
1.1. Terminology 1.1. Terminology
The term Claim is used as in [RFC8725]. The term Claim is used as in [RFC7519].
The terms Claim Key, Claim Value, and CWT Claims Set are used as in The terms Claim Key, Claim Value, and CWT Claims Set are used as in
[RFC8392]. [RFC8392].
The terms Attester, Attesting Environment and Verifier are used as in The terms Attester, Attesting Environment and Verifier are used as in
[I-D.ietf-rats-architecture]. [I-D.ietf-rats-architecture].
UCCS: Unprotected CWT Claims Set(s); CBOR map(s) of Claims as UCCS: Unprotected CWT Claims Set(s); CBOR map(s) of Claims as
defined by the CWT Claims Registry that are composed of pairs of defined by the CWT Claims Registry that are composed of pairs of
Claim Keys and Claim Values. Claim Keys and Claim Values.
skipping to change at page 4, line 5 skipping to change at page 4, line 5
All terms referenced or defined in this section are capitalized in All terms referenced or defined in this section are capitalized in
the remainder of this document. the remainder of this document.
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in "OPTIONAL" in this document are to be interpreted as described in
BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all
capitals, as shown here. capitals, as shown here.
2. Motivation and Requirements 2. Example Use Cases
Use cases involving the conveyance of Claims, in particular, remote Use cases involving the conveyance of Claims, in particular, remote
attestation procedures (RATS, see [I-D.ietf-rats-architecture]) attestation procedures (RATS, see [I-D.ietf-rats-architecture])
require a standardized data definition and encoding format that can require a standardized data definition and encoding format that can
be transferred and transported using different communication be transferred and transported using different communication
channels. As these are Claims, [RFC8392] is a suitable format. channels. As these are Claims, [RFC8392] is a suitable format.
However, the way these Claims are secured depends on the deployment, However, the way these Claims are secured depends on the deployment,
the security capabilities of the device, as well as their software the security capabilities of the device, as well as their software
stack. For example, a Claim may be securely stored and conveyed stack. For example, a Claim may be securely stored and conveyed
using a device's Trusted Execution Environment (TEE, see using a device's Trusted Execution Environment (TEE, see
skipping to change at page 4, line 29 skipping to change at page 4, line 29
be conveyed. Whether it is a transfer or transport, a Secure Channel be conveyed. Whether it is a transfer or transport, a Secure Channel
is presumed to be used for conveying such UCCS. The following is presumed to be used for conveying such UCCS. The following
sections further describe the RATS usage scenario and corresponding sections further describe the RATS usage scenario and corresponding
requirements for UCCS deployment. requirements for UCCS deployment.
3. Characteristics of a Secure Channel 3. Characteristics of a Secure Channel
A Secure Channel for the conveyance of UCCS needs to provide the A Secure Channel for the conveyance of UCCS needs to provide the
security properties that would otherwise be provided by COSE for a security properties that would otherwise be provided by COSE for a
CWT. In this regard, UCCS is similar in security considerations to CWT. In this regard, UCCS is similar in security considerations to
JWTs [RFC8725] using the algorithm "none". RFC 8725 states: "if a JWTs [RFC8725] using the algorithm "none". RFC 8725 states:
JWT is cryptographically protected end-to-end by a transport layer,
such as TLS using cryptographically current algorithms, there may be | [...] if a JWT is cryptographically protected end-to-end by a
no need to apply another layer of cryptographic protections to the | transport layer, such as TLS using cryptographically current
JWT. In such cases, the use of the "none" algorithm can be perfectly | algorithms, there may be no need to apply another layer of
acceptable.". Analogously, the considerations discussed in Sections | cryptographic protections to the JWT. In such cases, the use of
2.1, 3.1, and 3.2 of RFC 8725 apply to the use of UCCS as elaborated | the "none" algorithm can be perfectly acceptable.
on in this document.
The security considerations discussed, e.g., in Sections 2.1, 3.1,
and 3.2 of [RFC8725] apply in an analogous way to the use of UCCS as
elaborated on in this document.
Secure Channels are often set up in a handshake protocol that Secure Channels are often set up in a handshake protocol that
mutually derives a session key, where the handshake protocol mutually derives a session key, where the handshake protocol
establishes the authenticity of one of both ends of the establishes the (identity and thus) authenticity of one or both ends
communication. The session key can then be used to provide of the communication. The session key can then be used to provide
confidentiality and integrity of the transfer of information inside confidentiality and integrity of the transfer of information inside
the Secure Channel. A well-known example of a such a Secure Channel the Secure Channel. A well-known example of a such a Secure Channel
setup protocol is the TLS [RFC8446] handshake; the TLS record setup protocol is the TLS [RFC8446] handshake; the TLS record
protocol can then be used for secure conveyance. protocol can then be used for secure conveyance.
As UCCS were initially created for use in Remote ATtestation As UCCS were initially created for use in Remote ATtestation
procedureS (RATS) Secure Channels, the following subsection provides procedureS (RATS) Secure Channels, the following subsection provides
a discussion of their use in these channels. Where other a discussion of their use in these channels. Where other
environments are intended to be used to convey UCCS, similar environments are intended to be used to convey UCCS, similar
considerations need to be documented before UCCS can be used. considerations need to be documented before UCCS can be used.
skipping to change at page 5, line 18 skipping to change at page 5, line 24
UCCS and the Attester is the provider of the UCCS. UCCS and the Attester is the provider of the UCCS.
Secure Channels can be transient in nature. For the purposes of this Secure Channels can be transient in nature. For the purposes of this
specification, the mechanisms used to establish a Secure Channel are specification, the mechanisms used to establish a Secure Channel are
out of scope. out of scope.
As a minimum requirement in the scope of RATS Claims, the Verifier As a minimum requirement in the scope of RATS Claims, the Verifier
MUST authenticate the Attester as part of the establishment of the MUST authenticate the Attester as part of the establishment of the
Secure Channel. Furthermore, the channel MUST provide integrity of Secure Channel. Furthermore, the channel MUST provide integrity of
the communication from the Attester to the Verifier. If the communication from the Attester to the Verifier. If
confidentiality is also required, the receiving side needs to be be confidentiality is also required, the receiving side needs to be
authenticated as well, i.e., the Verifier and the Attester SHOULD authenticated as well; this can be achieved if the Verifier and the
mutually authenticate when establishing the Secure Channel. Attester mutually authenticate when establishing the Secure Channel.
The extent to which a Secure Channel can provide assurances that UCCS The extent to which a Secure Channel can provide assurances that UCCS
originate from a trustworthy attesting environment depends on the originate from a trustworthy attesting environment depends on the
characteristics of both the cryptographic mechanisms used to characteristics of both the cryptographic mechanisms used to
establish the channel and the characteristics of the attesting establish the channel and the characteristics of the attesting
environment itself. environment itself.
A Secure Channel established or maintained using weak cryptography A Secure Channel established or maintained using weak cryptography
may not provide the assurance required by a relying party of the may not provide the assurance required by a relying party of the
authenticity and integrity of the UCCS. authenticity and integrity of the UCCS.
skipping to change at page 6, line 5 skipping to change at page 6, line 11
approach might be to implement the attesting environment in a approach might be to implement the attesting environment in a
hardened environment such as a TEE [I-D.ietf-teep-architecture] or a hardened environment such as a TEE [I-D.ietf-teep-architecture] or a
TPM [TPM2]. TPM [TPM2].
When UCCS emerge from the Secure Channel and into the Verifier, the When UCCS emerge from the Secure Channel and into the Verifier, the
security properties of the Secure Channel no longer apply and UCCS security properties of the Secure Channel no longer apply and UCCS
have the same properties as any other unprotected data in the have the same properties as any other unprotected data in the
Verifier environment. If the Verifier subsequently forwards UCCS, Verifier environment. If the Verifier subsequently forwards UCCS,
they are treated as though they originated within the Verifier. they are treated as though they originated within the Verifier.
As with EATs nested in other EATs (Section 3.12.1.2 of As with EATs nested in other EATs (Section 3.20.1.2 of
[I-D.ietf-rats-eat]), the Secure Channel does not endorse fully [I-D.ietf-rats-eat]), the Secure Channel does not endorse fully
formed CWTs transferred through it. Effectively, the COSE envelope formed CWTs transferred through it. Effectively, the COSE envelope
of a CWT shields the CWT Claims Set from the endorsement of the of a CWT shields the CWT Claims Set from the endorsement of the
Secure Channel. (Note that EAT might add a nested UCCS Claim, and Secure Channel. (Note that EAT might add a nested UCCS Claim, and
this statement does not apply to UCCS nested into UCCS, only to fully this statement does not apply to UCCS nested into UCCS, only to fully
formed CWTs) formed CWTs)
3.2. Privacy Preserving Channels 3.2. Privacy Preserving Channels
A Secure Channel which preserves the privacy of the Attester may A Secure Channel which preserves the privacy of the Attester may
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+========+===========+======================================+ +========+===========+======================================+
| Tag | Data Item | Semantics | | Tag | Data Item | Semantics |
+========+===========+======================================+ +========+===========+======================================+
| TBD601 | map | Unprotected CWT Claims Set [RFCthis] | | TBD601 | map | Unprotected CWT Claims Set [RFCthis] |
+--------+-----------+--------------------------------------+ +--------+-----------+--------------------------------------+
Table 1: Values for Tags Table 1: Values for Tags
5. Security Considerations 5. Security Considerations
The security considerations of [RFC7049] and [RFC8392] apply. The security considerations of [RFC8949] apply. The security
considerations of [RFC8392] need to be applied analogously, replacing
the role of COSE with that of the Secured Channel.
Section 3 discusses security considerations for Secure Channels, in Section 3 discusses security considerations for Secure Channels, in
which UCCS might be used. This documents provides the CBOR tag which UCCS might be used. This document provides the CBOR tag
definition for UCCS and a discussion on security consideration for definition for UCCS and a discussion on security consideration for
the use of UCCS in Remote ATtestation procedureS (RATS). Uses of the use of UCCS in Remote ATtestation procedureS (RATS). Uses of
UCCS outside the scope of RATS are not covered by this document. The UCCS outside the scope of RATS are not covered by this document. The
UCCS specification - and the use of the UCCS CBOR tag, UCCS specification - and the use of the UCCS CBOR tag,
correspondingly - is not intended for use in a scope where a scope- correspondingly - is not intended for use in a scope where a scope-
specific security consideration discussion has not been conducted, specific security consideration discussion has not been conducted,
vetted and approved for that use. vetted and approved for that use.
5.1. General Considerations 5.1. General Considerations
skipping to change at page 8, line 10 skipping to change at page 8, line 18
5.2. AES-CBC_MAC 5.2. AES-CBC_MAC
* A given key should only be used for messages of fixed or known * A given key should only be used for messages of fixed or known
length. length.
* Different keys should be used for authentication and encryption * Different keys should be used for authentication and encryption
operations. operations.
* A mechanism to ensure that IV cannot be modified is required. * A mechanism to ensure that IV cannot be modified is required.
[I-D.ietf-cose-rfc8152bis-algs], Section 3.2.1 contains a detailed Section 3.2.1 of [I-D.ietf-cose-rfc8152bis-algs] contains a detailed
explanation of these considerations. explanation of these considerations.
5.3. AES-GCM 5.3. AES-GCM
* The key and nonce pair are unique for every encrypted message. * The key and nonce pair are unique for every encrypted message.
* The maximum number of messages to be encrypted for a given key is * The maximum number of messages to be encrypted for a given key is
not exceeded. not exceeded.
[I-D.ietf-cose-rfc8152bis-algs], Section 4.1.1 contains a detailed Section 4.1.1 of [I-D.ietf-cose-rfc8152bis-algs] contains a detailed
explanation of these considerations. explanation of these considerations.
5.4. AES-CCM 5.4. AES-CCM
* The key and nonce pair are unique for every encrypted message. * The key and nonce pair are unique for every encrypted message.
* The maximum number of messages to be encrypted for a given block * The maximum number of messages to be encrypted for a given block
cipher is not exceeded. cipher is not exceeded.
* The number of messages both successfully and unsuccessfully * The number of messages both successfully and unsuccessfully
decrypted is used to determine when rekeying is required. decrypted is used to determine when rekeying is required.
[I-D.ietf-cose-rfc8152bis-algs], Section 4.2.1 constains a detailed Section 4.2.1 of [I-D.ietf-cose-rfc8152bis-algs] contains a detailed
explanation of these considerations. explanation of these considerations.
5.5. ChaCha20 and Poly1305 5.5. ChaCha20 and Poly1305
* The nonce is unique for every encrypted message. * The nonce is unique for every encrypted message.
* The number of messages both successfully and unsuccessfully * The number of messages both successfully and unsuccessfully
decrypted is used to determine when rekeying is required. decrypted is used to determine when rekeying is required.
[I-D.ietf-cose-rfc8152bis-algs], Section 4.3.1 contains a detailed Section 4.3.1 of [I-D.ietf-cose-rfc8152bis-algs] contains a detailed
explanation of these considerations. explanation of these considerations.
6. References 6. References
6.1. Normative References 6.1. Normative References
[IANA.cbor-tags] [IANA.cbor-tags]
IANA, "Concise Binary Object Representation (CBOR) Tags", IANA, "Concise Binary Object Representation (CBOR) Tags",
<http://www.iana.org/assignments/cbor-tags>. <http://www.iana.org/assignments/cbor-tags>.
[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/rfc/rfc2119>. <https://www.rfc-editor.org/info/rfc2119>.
[RFC7049] Bormann, C. and P. Hoffman, "Concise Binary Object [RFC7519] Jones, M., Bradley, J., and N. Sakimura, "JSON Web Token
Representation (CBOR)", RFC 7049, DOI 10.17487/RFC7049, (JWT)", RFC 7519, DOI 10.17487/RFC7519, May 2015,
October 2013, <https://www.rfc-editor.org/rfc/rfc7049>. <https://www.rfc-editor.org/info/rfc7519>.
[RFC8152] Schaad, J., "CBOR Object Signing and Encryption (COSE)", [RFC8152] Schaad, J., "CBOR Object Signing and Encryption (COSE)",
RFC 8152, DOI 10.17487/RFC8152, July 2017, RFC 8152, DOI 10.17487/RFC8152, July 2017,
<https://www.rfc-editor.org/rfc/rfc8152>. <https://www.rfc-editor.org/info/rfc8152>.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
May 2017, <https://www.rfc-editor.org/rfc/rfc8174>. May 2017, <https://www.rfc-editor.org/info/rfc8174>.
[RFC8392] Jones, M., Wahlstroem, E., Erdtman, S., and H. Tschofenig, [RFC8392] Jones, M., Wahlstroem, E., Erdtman, S., and H. Tschofenig,
"CBOR Web Token (CWT)", RFC 8392, DOI 10.17487/RFC8392, "CBOR Web Token (CWT)", RFC 8392, DOI 10.17487/RFC8392,
May 2018, <https://www.rfc-editor.org/rfc/rfc8392>. May 2018, <https://www.rfc-editor.org/info/rfc8392>.
[RFC8446] Rescorla, E., "The Transport Layer Security (TLS) Protocol
Version 1.3", RFC 8446, DOI 10.17487/RFC8446, August 2018,
<https://www.rfc-editor.org/rfc/rfc8446>.
[RFC8725] Sheffer, Y., Hardt, D., and M. Jones, "JSON Web Token Best [RFC8725] Sheffer, Y., Hardt, D., and M. Jones, "JSON Web Token Best
Current Practices", BCP 225, RFC 8725, Current Practices", BCP 225, RFC 8725,
DOI 10.17487/RFC8725, February 2020, DOI 10.17487/RFC8725, February 2020,
<https://www.rfc-editor.org/rfc/rfc8725>. <https://www.rfc-editor.org/info/rfc8725>.
[TPM2] "Trusted Platform Module Library Specification, Family [RFC8949] Bormann, C. and P. Hoffman, "Concise Binary Object
“2.0”, Level 00, Revision 01.59 ed., Trusted Computing Representation (CBOR)", STD 94, RFC 8949,
Group", 2019. DOI 10.17487/RFC8949, December 2020,
<https://www.rfc-editor.org/info/rfc8949>.
6.2. Informative References 6.2. Informative References
[I-D.ietf-cose-rfc8152bis-algs] [I-D.ietf-cose-rfc8152bis-algs]
Schaad, J., "CBOR Object Signing and Encryption (COSE): Schaad, J., "CBOR Object Signing and Encryption (COSE):
Initial Algorithms", Work in Progress, Internet-Draft, Initial Algorithms", Work in Progress, Internet-Draft,
draft-ietf-cose-rfc8152bis-algs-12, 24 September 2020, draft-ietf-cose-rfc8152bis-algs-12, 24 September 2020,
<https://tools.ietf.org/html/draft-ietf-cose-rfc8152bis- <https://www.ietf.org/archive/id/draft-ietf-cose-
algs-12>. rfc8152bis-algs-12.txt>.
[I-D.ietf-cose-rfc8152bis-struct] [I-D.ietf-cose-rfc8152bis-struct]
Schaad, J., "CBOR Object Signing and Encryption (COSE): Schaad, J., "CBOR Object Signing and Encryption (COSE):
Structures and Process", Work in Progress, Internet-Draft, Structures and Process", Work in Progress, Internet-Draft,
draft-ietf-cose-rfc8152bis-struct-15, 1 February 2021, draft-ietf-cose-rfc8152bis-struct-15, 1 February 2021,
<https://tools.ietf.org/html/draft-ietf-cose-rfc8152bis- <https://www.ietf.org/archive/id/draft-ietf-cose-
struct-15>. rfc8152bis-struct-15.txt>.
[I-D.ietf-rats-architecture] [I-D.ietf-rats-architecture]
Birkholz, H., Thaler, D., Richardson, M., Smith, N., and Birkholz, H., Thaler, D., Richardson, M., Smith, N., and
W. Pan, "Remote Attestation Procedures Architecture", Work W. Pan, "Remote Attestation Procedures Architecture", Work
in Progress, Internet-Draft, draft-ietf-rats-architecture- in Progress, Internet-Draft, draft-ietf-rats-architecture-
12, 23 April 2021, <https://tools.ietf.org/html/draft- 12, 23 April 2021, <https://www.ietf.org/archive/id/draft-
ietf-rats-architecture-12>. ietf-rats-architecture-12.txt>.
[I-D.ietf-rats-eat] [I-D.ietf-rats-eat]
Mandyam, G., Lundblade, L., Ballesteros, M., and J. Mandyam, G., Lundblade, L., Ballesteros, M., and J.
O'Donoghue, "The Entity Attestation Token (EAT)", Work in O'Donoghue, "The Entity Attestation Token (EAT)", Work in
Progress, Internet-Draft, draft-ietf-rats-eat-09, 7 March Progress, Internet-Draft, draft-ietf-rats-eat-10, 7 June
2021, 2021, <https://www.ietf.org/archive/id/draft-ietf-rats-
<https://tools.ietf.org/html/draft-ietf-rats-eat-09>. eat-10.txt>.
[I-D.ietf-teep-architecture] [I-D.ietf-teep-architecture]
Pei, M., Tschofenig, H., Thaler, D., and D. Wheeler, Pei, M., Tschofenig, H., Thaler, D., and D. Wheeler,
"Trusted Execution Environment Provisioning (TEEP) "Trusted Execution Environment Provisioning (TEEP)
Architecture", Work in Progress, Internet-Draft, draft- Architecture", Work in Progress, Internet-Draft, draft-
ietf-teep-architecture-14, 22 February 2021, ietf-teep-architecture-14, 22 February 2021,
<https://tools.ietf.org/html/draft-ietf-teep-architecture- <https://www.ietf.org/archive/id/draft-ietf-teep-
14>. architecture-14.txt>.
[RFC8446] Rescorla, E., "The Transport Layer Security (TLS) Protocol
Version 1.3", RFC 8446, DOI 10.17487/RFC8446, August 2018,
<https://www.rfc-editor.org/info/rfc8446>.
[TPM2] "Trusted Platform Module Library Specification, Family
"2.0", Level 00, Revision 01.59 ed., Trusted Computing
Group", 2019.
Appendix A. Example Appendix A. Example
The example CWT Claims Set from Appendix A.1 of [RFC8392] can be The example CWT Claims Set from Appendix A.1 of [RFC8392] can be
turned into an UCCS by enclosing it with a tag number TBD601: turned into an UCCS by enclosing it with a tag number TBD601:
<TBD601>( <TBD601>(
{ {
/ iss / 1: "coap://as.example.com", / iss / 1: "coap://as.example.com",
/ sub / 2: "erikw", / sub / 2: "erikw",
skipping to change at page 11, line 4 skipping to change at page 11, line 18
/ sub / 2: "erikw", / sub / 2: "erikw",
/ aud / 3: "coap://light.example.com", / aud / 3: "coap://light.example.com",
/ exp / 4: 1444064944, / exp / 4: 1444064944,
/ nbf / 5: 1443944944, / nbf / 5: 1443944944,
/ iat / 6: 1443944944, / iat / 6: 1443944944,
/ cti / 7: h'0b71' / cti / 7: h'0b71'
} }
) )
Authors' Addresses Authors' Addresses
Henk Birkholz Henk Birkholz
Fraunhofer SIT Fraunhofer SIT
Rheinstrasse 75 Rheinstrasse 75
Darmstadt 64295 Darmstadt
Germany
Email: henk.birkholz@sit.fraunhofer.de Email: henk.birkholz@sit.fraunhofer.de
Jeremy O'Donoghue Jeremy O'Donoghue
Qualcomm Technologies Inc. Qualcomm Technologies Inc.
279 Farnborough Road 279 Farnborough Road
Farnborough Farnborough
GU14 7LS GU14 7LS
United Kingdom United Kingdom
skipping to change at page 11, line 29 skipping to change at page 11, line 45
Nancy Cam-Winget Nancy Cam-Winget
Cisco Systems Cisco Systems
3550 Cisco Way 3550 Cisco Way
San Jose, CA 95134 San Jose, CA 95134
United States of America United States of America
Email: ncamwing@cisco.com Email: ncamwing@cisco.com
Carsten Bormann Carsten Bormann
Universitaet Bremen TZI Universität Bremen TZI
Bibliothekstrasse 1 Postfach 330440
28369 Bremen D-28359 Bremen
Germany Germany
Phone: +49-421-218-63921 Phone: +49-421-218-63921
Email: cabo@tzi.de Email: cabo@tzi.org
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