draft-ietf-ace-cbor-web-token-15.txt   rfc8392.txt 
ACE Working Group M. Jones Internet Engineering Task Force (IETF) M. Jones
Internet-Draft Microsoft Request for Comments: 8392 Microsoft
Intended status: Standards Track E. Wahlstroem Category: Standards Track E. Wahlstroem
Expires: September 20, 2018 ISSN: 2070-1721
S. Erdtman S. Erdtman
Spotify AB Spotify AB
H. Tschofenig H. Tschofenig
ARM Ltd. ARM Ltd.
March 19, 2018 May 2018
CBOR Web Token (CWT) CBOR Web Token (CWT)
draft-ietf-ace-cbor-web-token-15
Abstract Abstract
CBOR Web Token (CWT) is a compact means of representing claims to be CBOR Web Token (CWT) is a compact means of representing claims to be
transferred between two parties. The claims in a CWT are encoded in transferred between two parties. The claims in a CWT are encoded in
the Concise Binary Object Representation (CBOR) and CBOR Object the Concise Binary Object Representation (CBOR), and CBOR Object
Signing and Encryption (COSE) is used for added application layer Signing and Encryption (COSE) is used for added application-layer
security protection. A claim is a piece of information asserted security protection. A claim is a piece of information asserted
about a subject and is represented as a name/value pair consisting of about a subject and is represented as a name/value pair consisting of
a claim name and a claim value. CWT is derived from JSON Web Token a claim name and a claim value. CWT is derived from JSON Web Token
(JWT) but uses CBOR rather than JSON. (JWT) but uses CBOR rather than JSON.
Status of This Memo Status of This Memo
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provisions of BCP 78 and BCP 79.
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Internet Standards is available in Section 2 of RFC 7841.
This Internet-Draft will expire on September 20, 2018. Information about the current status of this document, any errata,
and how to provide feedback on it may be obtained at
https://www.rfc-editor.org/info/rfc8392.
Copyright Notice Copyright Notice
Copyright (c) 2018 IETF Trust and the persons identified as the Copyright (c) 2018 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 . . . . . . . . . . . . . . . . . . . . . . . . 4
1.1. CBOR Related Terminology . . . . . . . . . . . . . . . . 3 1.1. CBOR-Related Terminology . . . . . . . . . . . . . . . . 4
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4
3. Claims . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 3. Claims . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
3.1. Registered Claims . . . . . . . . . . . . . . . . . . . . 5 3.1. Registered Claims . . . . . . . . . . . . . . . . . . . . 5
3.1.1. iss (Issuer) Claim . . . . . . . . . . . . . . . . . 5 3.1.1. iss (Issuer) Claim . . . . . . . . . . . . . . . . . 5
3.1.2. sub (Subject) Claim . . . . . . . . . . . . . . . . . 5 3.1.2. sub (Subject) Claim . . . . . . . . . . . . . . . . . 6
3.1.3. aud (Audience) Claim . . . . . . . . . . . . . . . . 5 3.1.3. aud (Audience) Claim . . . . . . . . . . . . . . . . 6
3.1.4. exp (Expiration Time) Claim . . . . . . . . . . . . . 5 3.1.4. exp (Expiration Time) Claim . . . . . . . . . . . . . 6
3.1.5. nbf (Not Before) Claim . . . . . . . . . . . . . . . 5 3.1.5. nbf (Not Before) Claim . . . . . . . . . . . . . . . 6
3.1.6. iat (Issued At) Claim . . . . . . . . . . . . . . . . 6 3.1.6. iat (Issued At) Claim . . . . . . . . . . . . . . . . 6
3.1.7. cti (CWT ID) Claim . . . . . . . . . . . . . . . . . 6 3.1.7. cti (CWT ID) Claim . . . . . . . . . . . . . . . . . 6
4. Summary of the claim names, keys, and value types . . . . . . 6 4. Summary of the Claim Names, Keys, and Value Types . . . . . . 7
5. CBOR Tags and Claim Values . . . . . . . . . . . . . . . . . 6 5. CBOR Tags and Claim Values . . . . . . . . . . . . . . . . . 7
6. CWT CBOR Tag . . . . . . . . . . . . . . . . . . . . . . . . 6 6. CWT CBOR Tag . . . . . . . . . . . . . . . . . . . . . . . . 7
7. Creating and Validating CWTs . . . . . . . . . . . . . . . . 7 7. Creating and Validating CWTs . . . . . . . . . . . . . . . . 8
7.1. Creating a CWT . . . . . . . . . . . . . . . . . . . . . 7 7.1. Creating a CWT . . . . . . . . . . . . . . . . . . . . . 8
7.2. Validating a CWT . . . . . . . . . . . . . . . . . . . . 8 7.2. Validating a CWT . . . . . . . . . . . . . . . . . . . . 9
8. Security Considerations . . . . . . . . . . . . . . . . . . . 9 8. Security Considerations . . . . . . . . . . . . . . . . . . . 10
9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 10 9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 11
9.1. CBOR Web Token (CWT) Claims Registry . . . . . . . . . . 10 9.1. CBOR Web Token (CWT) Claims Registry . . . . . . . . . . 11
9.1.1. Registration Template . . . . . . . . . . . . . . . . 11 9.1.1. Registration Template . . . . . . . . . . . . . . . . 12
9.1.2. Initial Registry Contents . . . . . . . . . . . . . . 11 9.1.2. Initial Registry Contents . . . . . . . . . . . . . . 12
9.2. Media Type Registration . . . . . . . . . . . . . . . . . 13 9.2. Media Type Registration . . . . . . . . . . . . . . . . . 14
9.2.1. Registry Contents . . . . . . . . . . . . . . . . . . 13 9.2.1. Registry Contents . . . . . . . . . . . . . . . . . . 14
9.3. CoAP Content-Formats Registration . . . . . . . . . . . . 14 9.3. CoAP Content-Formats Registration . . . . . . . . . . . . 14
9.3.1. Registry Contents . . . . . . . . . . . . . . . . . . 14 9.3.1. Registry Contents . . . . . . . . . . . . . . . . . . 15
9.4. CBOR Tag registration . . . . . . . . . . . . . . . . . . 14 9.4. CBOR Tag registration . . . . . . . . . . . . . . . . . . 15
9.4.1. Registry Contents . . . . . . . . . . . . . . . . . . 14 9.4.1. Registry Contents . . . . . . . . . . . . . . . . . . 15
10. References . . . . . . . . . . . . . . . . . . . . . . . . . 14 10. References . . . . . . . . . . . . . . . . . . . . . . . . . 15
10.1. Normative References . . . . . . . . . . . . . . . . . . 14 10.1. Normative References . . . . . . . . . . . . . . . . . . 15
10.2. Informative References . . . . . . . . . . . . . . . . . 15 10.2. Informative References . . . . . . . . . . . . . . . . . 16
Appendix A. Examples . . . . . . . . . . . . . . . . . . . . . . 16 Appendix A. Examples . . . . . . . . . . . . . . . . . . . . . . 17
A.1. Example CWT Claims Set . . . . . . . . . . . . . . . . . 16 A.1. Example CWT Claims Set . . . . . . . . . . . . . . . . . 17
A.2. Example keys . . . . . . . . . . . . . . . . . . . . . . 16 A.2. Example Keys . . . . . . . . . . . . . . . . . . . . . . 17
A.2.1. 128-bit Symmetric Key . . . . . . . . . . . . . . . . 17 A.2.1. 128-Bit Symmetric Key . . . . . . . . . . . . . . . . 18
A.2.2. 256-bit Symmetric Key . . . . . . . . . . . . . . . . 17 A.2.2. 256-Bit Symmetric Key . . . . . . . . . . . . . . . . 18
A.2.3. ECDSA P-256 256-bit COSE Key . . . . . . . . . . . . 17 A.2.3. Elliptic Curve Digital Signature Algorithm (ECDSA)
A.3. Example Signed CWT . . . . . . . . . . . . . . . . . . . 18 P-256 256-Bit COSE Key . . . . . . . . . . . . . . . 19
A.4. Example MACed CWT . . . . . . . . . . . . . . . . . . . . 19 A.3. Example Signed CWT . . . . . . . . . . . . . . . . . . . 19
A.5. Example Encrypted CWT . . . . . . . . . . . . . . . . . . 20 A.4. Example MACed CWT . . . . . . . . . . . . . . . . . . . . 20
A.6. Example Nested CWT . . . . . . . . . . . . . . . . . . . 21 A.5. Example Encrypted CWT . . . . . . . . . . . . . . . . . . 21
A.7. Example MACed CWT with a floating-point value . . . . . . 22 A.6. Example Nested CWT . . . . . . . . . . . . . . . . . . . 22
Appendix B. Acknowledgements . . . . . . . . . . . . . . . . . . 23 A.7. Example MACed CWT with a Floating-Point Value . . . . . . 23
Appendix C. Document History . . . . . . . . . . . . . . . . . . 23 Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . 24
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 27 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 25
1. Introduction 1. Introduction
The JSON Web Token (JWT) [RFC7519] is a standardized security token The JSON Web Token (JWT) [RFC7519] is a standardized security token
format that has found use in OAuth 2.0 and OpenID Connect format that has found use in OAuth 2.0 and OpenID Connect
deployments, among other applications. JWT uses JSON Web Signature deployments, among other applications. JWT uses JSON Web Signature
(JWS) [RFC7515] and JSON Web Encryption (JWE) [RFC7516] to secure the (JWS) [RFC7515] and JSON Web Encryption (JWE) [RFC7516] to secure the
contents of the JWT, which is a set of claims represented in JSON. contents of the JWT, which is a set of claims represented in JSON.
The use of JSON for encoding information is popular for Web and The use of JSON for encoding information is popular for Web and
native applications, but it is considered inefficient for some native applications, but it is considered inefficient for some
Internet of Things (IoT) systems that use low power radio Internet of Things (IoT) systems that use low-power radio
technologies. technologies.
An alternative encoding of claims is defined in this document. An alternative encoding of claims is defined in this document.
Instead of using JSON, as provided by JWTs, this specification uses Instead of using JSON, as provided by JWTs, this specification uses
CBOR [RFC7049] and calls this new structure "CBOR Web Token (CWT)", CBOR [RFC7049] and calls this new structure "CBOR Web Token (CWT)",
which is a compact means of representing secured claims to be which is a compact means of representing secured claims to be
transferred between two parties. CWT is closely related to JWT. It transferred between two parties. CWT is closely related to JWT. It
references the JWT claims and both its name and pronunciation are references the JWT claims and both its name and pronunciation are
derived from JWT. To protect the claims contained in CWTs, the CBOR derived from JWT (the suggested pronunciation of CWT is the same as
Object Signing and Encryption (COSE) [RFC8152] specification is used. the English word "cot"). To protect the claims contained in CWTs,
the CBOR Object Signing and Encryption (COSE) [RFC8152] specification
The suggested pronunciation of CWT is the same as the English word is used.
"cot".
1.1. CBOR Related Terminology 1.1. CBOR-Related Terminology
In JSON, maps are called objects and only have one kind of map key: a In JSON, maps are called objects and only have one kind of map key: a
string. CBOR uses strings, negative integers, and unsigned integers string. CBOR uses strings, negative integers, and unsigned integers
as map keys. The integers are used for compactness of encoding and as map keys. The integers are used for compactness of encoding and
easy comparison. The inclusion of strings allows for an additional easy comparison. The inclusion of strings allows for an additional
range of short encoded values to be used. range of short encoded values to be used.
2. Terminology 2. Terminology
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 BCP "OPTIONAL" in this document are to be interpreted as described in
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.
This document reuses terminology from JWT [RFC7519] and COSE This document reuses terminology from JWT [RFC7519] and COSE
[RFC8152]. [RFC8152].
StringOrURI StringOrURI
The "StringOrURI" term in this specification has the same meaning The "StringOrURI" term in this specification has the same meaning
and processing rules as the JWT "StringOrURI" term defined in and processing rules as the JWT "StringOrURI" term defined in
Section 2 of [RFC7519], except that it is represented as a CBOR Section 2 of [RFC7519], except that it is represented as a CBOR
text string instead of a JSON text string. text string instead of a JSON text string.
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the absence of such requirements, all claims that are not understood the absence of such requirements, all claims that are not understood
by implementations MUST be ignored. by implementations MUST be ignored.
To keep CWTs as small as possible, the Claim Keys are represented To keep CWTs as small as possible, the Claim Keys are represented
using integers or text strings. Section 4 summarizes all keys used using integers or text strings. Section 4 summarizes all keys used
to identify the claims defined in this document. to identify the claims defined in this document.
3.1. Registered Claims 3.1. Registered Claims
None of the claims defined below are intended to be mandatory to use None of the claims defined below are intended to be mandatory to use
or implement. They rather provide a starting point for a set of or implement. Rather, they provide a starting point for a set of
useful, interoperable claims. Applications using CWTs should define useful, interoperable claims. Applications using CWTs should define
which specific claims they use and when they are required or which specific claims they use and when they are required or
optional. optional.
3.1.1. iss (Issuer) Claim 3.1.1. iss (Issuer) Claim
The "iss" (issuer) claim has the same meaning and processing rules as The "iss" (issuer) claim has the same meaning and processing rules as
the "iss" claim defined in Section 4.1.1 of [RFC7519], except that the "iss" claim defined in Section 4.1.1 of [RFC7519], except that
the value is a StringOrURI, as defined in Section 2 of this the value is a StringOrURI, as defined in Section 2 of this
specification. The Claim Key 1 is used to identify this claim. specification. The Claim Key 1 is used to identify this claim.
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the value is a NumericDate, as defined in Section 2 of this the value is a NumericDate, as defined in Section 2 of this
specification. The Claim Key 6 is used to identify this claim. specification. The Claim Key 6 is used to identify this claim.
3.1.7. cti (CWT ID) Claim 3.1.7. cti (CWT ID) Claim
The "cti" (CWT ID) claim has the same meaning and processing rules as The "cti" (CWT ID) claim has the same meaning and processing rules as
the "jti" claim defined in Section 4.1.7 of [RFC7519], except that the "jti" claim defined in Section 4.1.7 of [RFC7519], except that
the value is a byte string. The Claim Key 7 is used to identify this the value is a byte string. The Claim Key 7 is used to identify this
claim. claim.
4. Summary of the claim names, keys, and value types 4. Summary of the Claim Names, Keys, and Value Types
+------+-----+----------------------------------+ +------+-----+----------------------------------+
| Name | Key | Value type | | Name | Key | Value Type |
+------+-----+----------------------------------+ +------+-----+----------------------------------+
| iss | 1 | text string | | iss | 1 | text string |
| sub | 2 | text string | | sub | 2 | text string |
| aud | 3 | text string | | aud | 3 | text string |
| exp | 4 | integer or floating-point number | | exp | 4 | integer or floating-point number |
| nbf | 5 | integer or floating-point number | | nbf | 5 | integer or floating-point number |
| iat | 6 | integer or floating-point number | | iat | 6 | integer or floating-point number |
| cti | 7 | byte string | | cti | 7 | byte string |
+------+-----+----------------------------------+ +------+-----+----------------------------------+
Table 1: Summary of the claim names, keys, and value types Table 1: Summary of the Claim Names, Keys, and Value Types
5. CBOR Tags and Claim Values 5. CBOR Tags and Claim Values
The claim values defined in this specification MUST NOT be prefixed The claim values defined in this specification MUST NOT be prefixed
with any CBOR tag. For instance, while CBOR tag 1 (epoch-based date/ with any CBOR tag. For instance, while CBOR tag 1 (epoch-based date/
time) could logically be prefixed to values of the "exp", "nbf", and time) could logically be prefixed to values of the "exp", "nbf", and
"iat" claims, this is unnecessary, since the representation of the "iat" claims, this is unnecessary since the representation of the
claim values is already specified by the claim definitions. Tagging claim values is already specified by the claim definitions. Tagging
claim values would only take up extra space without adding claim values would only take up extra space without adding
information. However, this does not prohibit future claim information. However, this does not prohibit future claim
definitions from requiring the use of CBOR tags for those specific definitions from requiring the use of CBOR tags for those specific
claims. claims.
6. CWT CBOR Tag 6. CWT CBOR Tag
How to determine that a CBOR data structure is a CWT is application- How to determine that a CBOR data structure is a CWT is application
dependent. In some cases, this information is known from the dependent. In some cases, this information is known from the
application context, such as from the position of the CWT in a data application context, such as from the position of the CWT in a data
structure at which the value must be a CWT. One method of indicating structure at which the value must be a CWT. One method of indicating
that a CBOR object is a CWT is the use of the "application/cwt" that a CBOR object is a CWT is the use of the "application/cwt"
content type by a transport protocol. content type by a transport protocol.
This section defines the CWT CBOR tag as another means for This section defines the CWT CBOR tag as another means for
applications to declare that a CBOR data structure is a CWT. Its use applications to declare that a CBOR data structure is a CWT. Its use
is optional and is intended for use in cases in which this is optional and is intended for use in cases in which this
information would not otherwise be known. information would not otherwise be known.
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If present, the CWT tag MUST prefix a tagged object using one of the If present, the CWT tag MUST prefix a tagged object using one of the
COSE CBOR tags. In this example, the COSE_Mac0 tag is used. The COSE CBOR tags. In this example, the COSE_Mac0 tag is used. The
actual COSE_Mac0 object has been excluded from this example. actual COSE_Mac0 object has been excluded from this example.
/ CWT CBOR tag / 61( / CWT CBOR tag / 61(
/ COSE_Mac0 CBOR tag / 17( / COSE_Mac0 CBOR tag / 17(
/ COSE_Mac0 object / / COSE_Mac0 object /
) )
) )
Figure 1: Example of a CWT tag usage Figure 1: Example of CWT Tag Usage
7. Creating and Validating CWTs 7. Creating and Validating CWTs
7.1. Creating a CWT 7.1. Creating a CWT
To create a CWT, the following steps are performed. The order of the To create a CWT, the following steps are performed. The order of the
steps is not significant in cases where there are no dependencies steps is not significant in cases where there are no dependencies
between the inputs and outputs of the steps. between the inputs and outputs of the steps.
1. Create a CWT Claims Set containing the desired claims. 1. Create a CWT Claims Set containing the desired claims.
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4. Verify that the resulting COSE Header includes only parameters 4. Verify that the resulting COSE Header includes only parameters
and values whose syntax and semantics are both understood and and values whose syntax and semantics are both understood and
supported or that are specified as being ignored when not supported or that are specified as being ignored when not
understood. understood.
5. Depending upon whether the CWT is a signed, MACed, or encrypted, 5. Depending upon whether the CWT is a signed, MACed, or encrypted,
there are three cases: there are three cases:
* If the CWT is a COSE_Sign/COSE_Sign1, follow the steps * If the CWT is a COSE_Sign/COSE_Sign1, follow the steps
specified in [RFC8152] Section 4 (Signing Objects) for specified in Section 4 of [RFC8152] ("Signing Objects") for
validating a COSE_Sign/COSE_Sign1 object. Let the Message be validating a COSE_Sign/COSE_Sign1 object. Let the Message be
the COSE_Sign/COSE_Sign1 payload. the COSE_Sign/COSE_Sign1 payload.
* Else, if the CWT is a COSE_Mac/COSE_Mac0, follow the steps * Else, if the CWT is a COSE_Mac/COSE_Mac0, follow the steps
specified in [RFC8152] Section 6 (MAC Objects) for validating specified in Section 6 of [RFC8152] ("MAC Objects") for
a COSE_Mac/COSE_Mac0 object. Let the Message be the COSE_Mac/ validating a COSE_Mac/COSE_Mac0 object. Let the Message be
COSE_Mac0 payload. the COSE_Mac/COSE_Mac0 payload.
* Else, if the CWT is a COSE_Encrypt/COSE_Encrypt0 object, * Else, if the CWT is a COSE_Encrypt/COSE_Encrypt0 object,
follow the steps specified in [RFC8152] Section 5 (Encryption follow the steps specified in Section 5 of [RFC8152]
Objects) for validating a COSE_Encrypt/COSE_Encrypt0 object. ("Encryption Objects") for validating a COSE_Encrypt/
Let the Message be the resulting plaintext. COSE_Encrypt0 object. Let the Message be the resulting
plaintext.
6. If the Message begins with a COSE CBOR tag, then the Message is a 6. If the Message begins with a COSE CBOR tag, then the Message is a
CWT that was the subject of nested signing, MACing, or encryption CWT that was the subject of nested signing, MACing, or encryption
operations. In this case, return to Step 1, using the Message as operations. In this case, return to Step 1, using the Message as
the CWT. the CWT.
7. Verify that the Message is a valid CBOR map; let the CWT Claims 7. Verify that the Message is a valid CBOR map; let the CWT Claims
Set be this CBOR map. Set be this CBOR map.
8. Security Considerations 8. Security Considerations
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Since the claims conveyed in a CWT may be used to make authorization Since the claims conveyed in a CWT may be used to make authorization
decisions, it is not only important to protect the CWT in transit but decisions, it is not only important to protect the CWT in transit but
also to ensure that the recipient can authenticate the party that also to ensure that the recipient can authenticate the party that
assembled the claims and created the CWT. Without trust of the assembled the claims and created the CWT. Without trust of the
recipient in the party that created the CWT, no sensible recipient in the party that created the CWT, no sensible
authorization decision can be made. Furthermore, the creator of the authorization decision can be made. Furthermore, the creator of the
CWT needs to carefully evaluate each claim value prior to including CWT needs to carefully evaluate each claim value prior to including
it in the CWT so that the recipient can be assured of the validity of it in the CWT so that the recipient can be assured of the validity of
the information provided. the information provided.
While syntactically the signing and encryption operations for Nested Syntactically, the signing and encryption operations for Nested CWTs
CWTs may be applied in any order, if both signing and encryption are may be applied in any order; however, if both signing and encryption
necessary, normally producers should sign the message and then are necessary, producers normally should sign the message and then
encrypt the result (thus encrypting the signature). This prevents encrypt the result (thus encrypting the signature). This prevents
attacks in which the signature is stripped, leaving just an encrypted attacks in which the signature is stripped, leaving just an encrypted
message, as well as providing privacy for the signer. Furthermore, message, as well as providing privacy for the signer. Furthermore,
signatures over encrypted text are not considered valid in many signatures over encrypted text are not considered valid in many
jurisdictions. jurisdictions.
9. IANA Considerations 9. IANA Considerations
9.1. CBOR Web Token (CWT) Claims Registry 9.1. CBOR Web Token (CWT) Claims Registry
This section establishes the IANA "CBOR Web Token (CWT) Claims" IANA has created the "CBOR Web Token (CWT) Claims" registry
registry. [IANA.CWT.Claims].
Registration requests are evaluated using the criteria described in Registration requests are evaluated using the criteria described in
the Claim Key instructions in the registration template below after a the Claim Key instructions in the registration template below after a
three-week review period on the cwt-reg-review@ietf.org mailing list, three-week review period on the cwt-reg-review@ietf.org mailing list,
on the advice of one or more Designated Experts. However, to allow on the advice of one or more Designated Experts [RFC8126]. However,
for the allocation of values prior to publication, the Designated to allow for the allocation of values prior to publication, the
Experts may approve registration once they are satisfied that such a Designated Experts may approve registration once they are satisfied
specification will be published. [[ Note to the RFC Editor: The name that such a specification will be published.
of the mailing list should be determined in consultation with the
IESG and IANA. Suggested name: cwt-reg-review@ietf.org. ]]
Registration requests sent to the mailing list for review should use Registration requests sent to the mailing list for review should use
an appropriate subject (e.g., "Request to register claim: example"). an appropriate subject (e.g., "Request to register claim: example").
Registration requests that are undetermined for a period longer than Registration requests that are undetermined for a period longer than
21 days can be brought to the IESG's attention (using the 21 days can be brought to the IESG's attention (using the
iesg@ietf.org mailing list) for resolution. iesg@ietf.org mailing list) for resolution.
Criteria that should be applied by the Designated Experts includes Criteria that should be applied by the Designated Experts includes
determining whether the proposed registration duplicates existing determining whether the proposed registration duplicates existing
functionality, whether it is likely to be of general applicability or functionality, whether it is likely to be of general applicability or
skipping to change at page 11, line 25 skipping to change at page 12, line 25
[IANA.JWT.Claims]. CWT claims should normally have a [IANA.JWT.Claims]. CWT claims should normally have a
corresponding JWT claim. If a corresponding JWT claim would not corresponding JWT claim. If a corresponding JWT claim would not
make sense, the Designated Experts can choose to accept make sense, the Designated Experts can choose to accept
registrations for which the JWT Claim Name is listed as "N/A". registrations for which the JWT Claim Name is listed as "N/A".
Claim Key: Claim Key:
CBOR map key for the claim. Different ranges of values use CBOR map key for the claim. Different ranges of values use
different registration policies [RFC8126]. Integer values from different registration policies [RFC8126]. Integer values from
-256 to 255 and strings of length 1 are designated as Standards -256 to 255 and strings of length 1 are designated as Standards
Action. Integer values from -65536 to -257 and from 256 to 65535 Action. Integer values from -65536 to -257 and from 256 to 65535
and strings of length 2 are designated as Specification Required. along with strings of length 2 are designated as Specification
Integer values greater than 65535 and strings of length greater Required. Integer values greater than 65535 and strings of length
than 2 are designated as Expert Review. Integer values less than greater than 2 are designated as Expert Review. Integer values
-65536 are marked as Private Use. less than -65536 are marked as Private Use.
Claim Value Type(s): Claim Value Type(s):
CBOR types that can be used for the claim value. CBOR types that can be used for the claim value.
Change Controller: Change Controller:
For Standards Track RFCs, list the "IESG". For others, give the For Standards Track RFCs, list the "IESG". For others, give the
name of the responsible party. Other details (e.g., postal name of the responsible party. Other details (e.g., postal
address, email address, home page URI) may also be included. address, email address, home page URI) may also be included.
Specification Document(s): Specification Document(s):
skipping to change at page 11, line 52 skipping to change at page 12, line 52
included but is not required. included but is not required.
9.1.2. Initial Registry Contents 9.1.2. Initial Registry Contents
o Claim Name: (RESERVED) o Claim Name: (RESERVED)
o Claim Description: This registration reserves the key value 0. o Claim Description: This registration reserves the key value 0.
o JWT Claim Name: N/A o JWT Claim Name: N/A
o Claim Key: 0 o Claim Key: 0
o Claim Value Type(s): N/A o Claim Value Type(s): N/A
o Change Controller: IESG o Change Controller: IESG
o Specification Document(s): [[ this specification ]] o Specification Document(s): [RFC8392]
o Claim Name: "iss" o Claim Name: iss
o Claim Description: Issuer o Claim Description: Issuer
o JWT Claim Name: "iss" o JWT Claim Name: iss
o Claim Key: 1 o Claim Key: 1
o Claim Value Type(s): text string o Claim Value Type(s): text string
o Change Controller: IESG o Change Controller: IESG
o Specification Document(s): Section 3.1.1 of [[ this specification o Specification Document(s): Section 3.1.1 of [RFC8392]
]]
o Claim Name: "sub" o Claim Name: sub
o Claim Description: Subject o Claim Description: Subject
o JWT Claim Name: "sub" o JWT Claim Name: sub
o Claim Key: 2 o Claim Key: 2
o Claim Value Type(s): text string o Claim Value Type(s): text string
o Change Controller: IESG o Change Controller: IESG
o Specification Document(s): Section 3.1.2 of [[ this specification o Specification Document(s): Section 3.1.2 of [RFC8392]
]]
o Claim Name: "aud" o Claim Name: aud
o Claim Description: Audience o Claim Description: Audience
o JWT Claim Name: "aud" o JWT Claim Name: aud
o Claim Key: 3 o Claim Key: 3
o Claim Value Type(s): text string o Claim Value Type(s): text string
o Change Controller: IESG o Change Controller: IESG
o Specification Document(s): Section 3.1.3 of [[ this specification o Specification Document(s): Section 3.1.3 of [RFC8392]
]]
o Claim Name: "exp" o Claim Name: exp
o Claim Description: Expiration Time o Claim Description: Expiration Time
o JWT Claim Name: "exp" o JWT Claim Name: exp
o Claim Key: 4 o Claim Key: 4
o Claim Value Type(s): integer or floating-point number o Claim Value Type(s): integer or floating-point number
o Change Controller: IESG o Change Controller: IESG
o Specification Document(s): Section 3.1.4 of [[ this specification o Specification Document(s): Section 3.1.4 of [RFC8392]
]]
o Claim Name: "nbf" o Claim Name: nbf
o Claim Description: Not Before o Claim Description: Not Before
o JWT Claim Name: "nbf" o JWT Claim Name: nbf
o Claim Key: 5 o Claim Key: 5
o Claim Value Type(s): integer or floating-point number o Claim Value Type(s): integer or floating-point number
o Change Controller: IESG o Change Controller: IESG
o Specification Document(s): Section 3.1.5 of [[ this specification o Specification Document(s): Section 3.1.5 of [RFC8392]
]]
o Claim Name: "iat" o Claim Name: iat
o Claim Description: Issued At o Claim Description: Issued At
o JWT Claim Name: "iat" o JWT Claim Name: iat
o Claim Key: 6 o Claim Key: 6
o Claim Value Type(s): integer or floating-point number o Claim Value Type(s): integer or floating-point number
o Change Controller: IESG o Change Controller: IESG
o Specification Document(s): Section 3.1.6 of [[ this specification o Specification Document(s): Section 3.1.6 of [RFC8392]
]] o Claim Name: cti
o Claim Name: "cti"
o Claim Description: CWT ID o Claim Description: CWT ID
o JWT Claim Name: "jti" o JWT Claim Name: jti
o Claim Key: 7 o Claim Key: 7
o Claim Value Type(s): byte string o Claim Value Type(s): byte string
o Change Controller: IESG o Change Controller: IESG
o Specification Document(s): Section 3.1.7 of [[ this specification o Specification Document(s): Section 3.1.7 of [RFC8392]
]]
9.2. Media Type Registration 9.2. Media Type Registration
This section registers the "application/cwt" media type in the "Media IANA has registered the "application/cwt" media type in the "Media
Types" registry [IANA.MediaTypes] in the manner described in RFC 6838 Types" registry [IANA.MediaTypes] in the manner described in RFC 6838
[RFC6838], which can be used to indicate that the content is a CWT. [RFC6838], which can be used to indicate that the content is a CWT.
9.2.1. Registry Contents 9.2.1. Registry Contents
o Type name: application o Type name: application
o Subtype name: cwt o Subtype name: cwt
o Required parameters: N/A o Required parameters: N/A
o Optional parameters: N/A o Optional parameters: N/A
o Encoding considerations: binary o Encoding considerations: binary
o Security considerations: See the Security Considerations section o Security considerations: See the Security Considerations section
of [[ this specification ]] of [RFC8392]
o Interoperability considerations: N/A o Interoperability considerations: N/A
o Published specification: [[ this specification ]] o Published specification: [RFC8392]
o Applications that use this media type: IoT applications sending o Applications that use this media type: IoT applications sending
security tokens over HTTP(S), CoAP(S), and other transports. security tokens over HTTP(S), CoAP(S), and other transports.
o Fragment identifier considerations: N/A o Fragment identifier considerations: N/A
o Additional information: o Additional information:
Magic number(s): N/A Magic number(s): N/A
File extension(s): N/A File extension(s): N/A
Macintosh file type code(s): N/A Macintosh file type code(s): N/A
o Person & email address to contact for further information: o Person & email address to contact for further information:
IESG, iesg@ietf.org IESG, iesg@ietf.org
o Intended usage: COMMON o Intended usage: COMMON
o Restrictions on usage: none o Restrictions on usage: none
o Author: Michael B. Jones, mbj@microsoft.com o Author: Michael B. Jones, mbj@microsoft.com
o Change controller: IESG o Change controller: IESG
o Provisional registration? No o Provisional registration? No
9.3. CoAP Content-Formats Registration 9.3. CoAP Content-Formats Registration
This section registers the CoAP Content-Format ID for the IANA has registered the CoAP Content-Format ID for the "application/
"application/cwt" media type in the "CoAP Content-Formats" registry cwt" media type in the "CoAP Content-Formats" registry
[IANA.CoAP.Content-Formats]. [IANA.CoAP.Content-Formats].
9.3.1. Registry Contents 9.3.1. Registry Contents
o Media Type: application/cwt o Media Type: application/cwt
o Encoding: - o Encoding: -
o Id: TBD (maybe 61) o Id: 61
o Reference: [[ this specification ]] o Reference: [RFC8392]
9.4. CBOR Tag registration 9.4. CBOR Tag registration
This section registers the CWT CBOR tag in the "CBOR Tags" registry IANA has registered the CWT CBOR tag in the "CBOR Tags" registry
[IANA.CBOR.Tags]. [IANA.CBOR.Tags].
9.4.1. Registry Contents 9.4.1. Registry Contents
o CBOR Tag: TBD (maybe 61 to use the same value as the Content- o CBOR Tag: 61
Format)
o Data Item: CBOR Web Token (CWT) o Data Item: CBOR Web Token (CWT)
o Semantics: CBOR Web Token (CWT), as defined in [[ this o Semantics: CBOR Web Token (CWT), as defined in [RFC8392]
specification ]] o Reference: [RFC8392]
o Description of Semantics: [[ this specification ]]
o Point of Contact: Michael B. Jones, mbj@microsoft.com o Point of Contact: Michael B. Jones, mbj@microsoft.com
10. References 10. References
10.1. Normative References 10.1. 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/>.
cbor-tags.xhtml>.
[IANA.CoAP.Content-Formats] [IANA.CoAP.Content-Formats]
IANA, "CoAP Content-Formats", IANA, "CoAP Content-Formats",
<http://www.iana.org/assignments/core-parameters/ <https://www.iana.org/assignments/core-parameters/>.
core-parameters.xhtml#content-formats>.
[IANA.CWT.Claims]
IANA, "CBOR Web Token (CWT) Claims",
<http://www.iana.org/assignments/cwt>.
[IANA.MediaTypes] [IANA.MediaTypes]
IANA, "Media Types", IANA, "Media Types",
<http://www.iana.org/assignments/media-types>. <http://www.iana.org/assignments/media-types>.
[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>.
skipping to change at page 16, line 29 skipping to change at page 17, line 29
A.1. Example CWT Claims Set A.1. Example CWT Claims Set
The CWT Claims Set used for the different examples displays usage of The CWT Claims Set used for the different examples displays usage of
all the defined claims. For signed and MACed examples, the CWT all the defined claims. For signed and MACed examples, the CWT
Claims Set is the CBOR encoding as a byte string. Claims Set is the CBOR encoding as a byte string.
a70175636f61703a2f2f61732e6578616d706c652e636f6d02656572696b7703 a70175636f61703a2f2f61732e6578616d706c652e636f6d02656572696b7703
7818636f61703a2f2f6c696768742e6578616d706c652e636f6d041a5612aeb0 7818636f61703a2f2f6c696768742e6578616d706c652e636f6d041a5612aeb0
051a5610d9f0061a5610d9f007420b71 051a5610d9f0061a5610d9f007420b71
Figure 2: Example CWT Claims Set as hex string Figure 2: Example CWT Claims Set as Hex String
{ {
/ iss / 1: "coap://as.example.com", / iss / 1: "coap://as.example.com",
/ 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'
} }
Figure 3: Example CWT Claims Set in CBOR diagnostic notation Figure 3: Example CWT Claims Set in CBOR Diagnostic Notation
A.2. Example keys A.2. Example Keys
This section contains the keys used to sign, MAC, and encrypt the This section contains the keys used to sign, MAC, and encrypt the
messages in this appendix. Line breaks are for display purposes messages in this appendix. Line breaks are for display purposes
only. only.
A.2.1. 128-bit Symmetric Key A.2.1. 128-Bit Symmetric Key
a42050231f4c4d4d3051fdc2ec0a3851d5b3830104024c53796d6d6574726963 a42050231f4c4d4d3051fdc2ec0a3851d5b3830104024c53796d6d6574726963
313238030a 313238030a
Figure 4: 128-bit symmetric COSE_Key as hex string Figure 4: 128-Bit Symmetric COSE_Key as Hex String
{ {
/ k / -1: h'231f4c4d4d3051fdc2ec0a3851d5b383' / k / -1: h'231f4c4d4d3051fdc2ec0a3851d5b383'
/ kty / 1: 4 / Symmetric /, / kty / 1: 4 / Symmetric /,
/ kid / 2: h'53796d6d6574726963313238' / 'Symmetric128' /, / kid / 2: h'53796d6d6574726963313238' / 'Symmetric128' /,
/ alg / 3: 10 / AES-CCM-16-64-128 / / alg / 3: 10 / AES-CCM-16-64-128 /
} }
Figure 5: 128-bit symmetric COSE_Key in CBOR diagnostic notation Figure 5: 128-Bit Symmetric COSE_Key in CBOR Diagnostic Notation
A.2.2. 256-bit Symmetric Key A.2.2. 256-Bit Symmetric Key
a4205820403697de87af64611c1d32a05dab0fe1fcb715a86ab435f1ec99192d a4205820403697de87af64611c1d32a05dab0fe1fcb715a86ab435f1ec99192d
795693880104024c53796d6d6574726963323536030a 795693880104024c53796d6d6574726963323536030a
Figure 6: 256-bit symmetric COSE_Key as hex string Figure 6: 256-Bit Symmetric COSE_Key as Hex String
{ {
/ k / -1: h'403697de87af64611c1d32a05dab0fe1fcb715a86ab435f1 / k / -1: h'403697de87af64611c1d32a05dab0fe1fcb715a86ab435f1
ec99192d79569388' ec99192d79569388'
/ kty / 1: 4 / Symmetric /, / kty / 1: 4 / Symmetric /,
/ kid / 4: h'53796d6d6574726963323536' / 'Symmetric256' /, / kid / 4: h'53796d6d6574726963323536' / 'Symmetric256' /,
/ alg / 3: 4 / HMAC 256/64 / / alg / 3: 4 / HMAC 256/64 /
} }
Figure 7: 256-bit symmetric COSE_Key in CBOR diagnostic notation Figure 7: 256-Bit Symmetric COSE_Key in CBOR Diagnostic Notation
A.2.3. ECDSA P-256 256-bit COSE Key A.2.3. Elliptic Curve Digital Signature Algorithm (ECDSA) P-256 256-Bit
COSE Key
a72358206c1382765aec5358f117733d281c1c7bdc39884d04a45a1e6c67c858 a72358206c1382765aec5358f117733d281c1c7bdc39884d04a45a1e6c67c858
bc206c1922582060f7f1a780d8a783bfb7a2dd6b2796e8128dbbcef9d3d168db bc206c1922582060f7f1a780d8a783bfb7a2dd6b2796e8128dbbcef9d3d168db
9529971a36e7b9215820143329cce7868e416927599cf65a34f3ce2ffda55a7e 9529971a36e7b9215820143329cce7868e416927599cf65a34f3ce2ffda55a7e
ca69ed8919a394d42f0f2001010202524173796d6d6574726963454344534132 ca69ed8919a394d42f0f2001010202524173796d6d6574726963454344534132
35360326 35360326
Figure 8: ECDSA 256-bit COSE Key as hex string Figure 8: ECDSA 256-Bit COSE Key as Hex String
{ {
/ d / -4: h'6c1382765aec5358f117733d281c1c7bdc39884d04a45a1e / d / -4: h'6c1382765aec5358f117733d281c1c7bdc39884d04a45a1e
6c67c858bc206c19', 6c67c858bc206c19',
/ y / -3: h'60f7f1a780d8a783bfb7a2dd6b2796e8128dbbcef9d3d168 / y / -3: h'60f7f1a780d8a783bfb7a2dd6b2796e8128dbbcef9d3d168
db9529971a36e7b9', db9529971a36e7b9',
/ x / -2: h'143329cce7868e416927599cf65a34f3ce2ffda55a7eca69 / x / -2: h'143329cce7868e416927599cf65a34f3ce2ffda55a7eca69
ed8919a394d42f0f', ed8919a394d42f0f',
/ crv / -1: 1 / P-256 /, / crv / -1: 1 / P-256 /,
/ kty / 1: 2 / EC2 /, / kty / 1: 2 / EC2 /,
/ kid / 2: h'4173796d6d657472696345434453413 / kid / 2: h'4173796d6d657472696345434453413
23536' / 'AsymmetricECDSA256' /, 23536' / 'AsymmetricECDSA256' /,
/ alg / 3: -7 / ECDSA 256 / / alg / 3: -7 / ECDSA 256 /
} }
Figure 9: ECDSA 256-bit COSE Key in CBOR diagnostic notation Figure 9: ECDSA 256-Bit COSE Key in CBOR Diagnostic Notation
A.3. Example Signed CWT A.3. Example Signed CWT
This section shows a signed CWT with a single recipient and a full This section shows a signed CWT with a single recipient and a full
CWT Claims Set. CWT Claims Set.
The signature is generated using the private key listed in The signature is generated using the private key listed in
Appendix A.2.3 and it can be validated using the public key from Appendix A.2.3, and it can be validated using the public key from
Appendix A.2.3. Line breaks are for display purposes only. Appendix A.2.3. Line breaks are for display purposes only.
d28443a10126a104524173796d6d657472696345434453413235365850a701756 d28443a10126a104524173796d6d657472696345434453413235365850a701756
36f61703a2f2f61732e6578616d706c652e636f6d02656572696b77037818636f 36f61703a2f2f61732e6578616d706c652e636f6d02656572696b77037818636f
61703a2f2f6c696768742e6578616d706c652e636f6d041a5612aeb0051a5610d 61703a2f2f6c696768742e6578616d706c652e636f6d041a5612aeb0051a5610d
9f0061a5610d9f007420b7158405427c1ff28d23fbad1f29c4c7c6a555e601d6f 9f0061a5610d9f007420b7158405427c1ff28d23fbad1f29c4c7c6a555e601d6f
a29f9179bc3d7438bacaca5acd08c8d4d4f96131680c429a01f85951ecee743a5 a29f9179bc3d7438bacaca5acd08c8d4d4f96131680c429a01f85951ecee743a5
2b9b63632c57209120e1c9e30 2b9b63632c57209120e1c9e30
Figure 10: Signed CWT as hex string Figure 10: Signed CWT as Hex String
18( 18(
[ [
/ protected / << { / protected / << {
/ alg / 1: -7 / ECDSA 256 / / alg / 1: -7 / ECDSA 256 /
} >>, } >>,
/ unprotected / { / unprotected / {
/ kid / 4: h'4173796d6d657472696345434453413 / kid / 4: h'4173796d6d657472696345434453413
23536' / 'AsymmetricECDSA256' / 23536' / 'AsymmetricECDSA256' /
}, },
skipping to change at page 19, line 30 skipping to change at page 20, line 30
/ iat / 6: 1443944944, / iat / 6: 1443944944,
/ cti / 7: h'0b71' / cti / 7: h'0b71'
} >>, } >>,
/ signature / h'5427c1ff28d23fbad1f29c4c7c6a555e601d6fa29f / signature / h'5427c1ff28d23fbad1f29c4c7c6a555e601d6fa29f
9179bc3d7438bacaca5acd08c8d4d4f96131680c42 9179bc3d7438bacaca5acd08c8d4d4f96131680c42
9a01f85951ecee743a52b9b63632c57209120e1c9e 9a01f85951ecee743a52b9b63632c57209120e1c9e
30' 30'
] ]
) )
Figure 11: Signed CWT in CBOR diagnostic notation Figure 11: Signed CWT in CBOR Diagnostic Notation
A.4. Example MACed CWT A.4. Example MACed CWT
This section shows a MACed CWT with a single recipient, a full CWT This section shows a MACed CWT with a single recipient, a full CWT
Claims Set, and a CWT tag. Claims Set, and a CWT tag.
The MAC is generated using the 256-bit symmetric key from The MAC is generated using the 256-bit symmetric key from
Appendix A.2.2 with a 64-bit truncation. Line breaks are for display Appendix A.2.2 with a 64-bit truncation. Line breaks are for display
purposes only. purposes only.
d83dd18443a10104a1044c53796d6d65747269633235365850a70175636f6170 d83dd18443a10104a1044c53796d6d65747269633235365850a70175636f6170
3a2f2f61732e6578616d706c652e636f6d02656572696b77037818636f61703a 3a2f2f61732e6578616d706c652e636f6d02656572696b77037818636f61703a
2f2f6c696768742e6578616d706c652e636f6d041a5612aeb0051a5610d9f006 2f2f6c696768742e6578616d706c652e636f6d041a5612aeb0051a5610d9f006
1a5610d9f007420b7148093101ef6d789200 1a5610d9f007420b7148093101ef6d789200
Figure 12: MACed CWT with CWT tag as hex string Figure 12: MACed CWT with CWT Tag as Hex String
61( 61(
17( 17(
[ [
/ protected / << { / protected / << {
/ alg / 1: 4 / HMAC-256-64 / / alg / 1: 4 / HMAC-256-64 /
} >>, } >>,
/ unprotected / { / unprotected / {
/ kid / 4: h'53796d6d6574726963323536' / 'Symmetric256' / / kid / 4: h'53796d6d6574726963323536' / 'Symmetric256' /
}, },
skipping to change at page 20, line 28 skipping to change at page 21, line 28
/ 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'
} >>, } >>,
/ tag / h'093101ef6d789200' / tag / h'093101ef6d789200'
] ]
) )
) )
Figure 13: MACed CWT with CWT tag in CBOR diagnostic notation Figure 13: MACed CWT with CWT Tag in CBOR Diagnostic Notation
A.5. Example Encrypted CWT A.5. Example Encrypted CWT
This section shows an encrypted CWT with a single recipient and a This section shows an encrypted CWT with a single recipient and a
full CWT Claims Set. full CWT Claims Set.
The encryption is done with AES-CCM mode using the 128-bit symmetric The encryption is done with AES-CCM mode using the 128-bit symmetric
key from Appendix A.2.1 with a 64-bit tag and 13-byte nonce, i.e., key from Appendix A.2.1 with a 64-bit tag and 13-byte nonce, i.e.,
COSE AES-CCM-16-64-128. Line breaks are for display purposes only. COSE AES-CCM-16-64-128. Line breaks are for display purposes only.
d08343a1010aa2044c53796d6d6574726963313238054d99a0d7846e762c49ff d08343a1010aa2044c53796d6d6574726963313238054d99a0d7846e762c49ff
e8a63e0b5858b918a11fd81e438b7f973d9e2e119bcb22424ba0f38a80f27562 e8a63e0b5858b918a11fd81e438b7f973d9e2e119bcb22424ba0f38a80f27562
f400ee1d0d6c0fdb559c02421fd384fc2ebe22d7071378b0ea7428fff157444d f400ee1d0d6c0fdb559c02421fd384fc2ebe22d7071378b0ea7428fff157444d
45f7e6afcda1aae5f6495830c58627087fc5b4974f319a8707a635dd643b 45f7e6afcda1aae5f6495830c58627087fc5b4974f319a8707a635dd643b
Figure 14: Encrypted CWT as hex string Figure 14: Encrypted CWT as Hex String
16( 16(
[ [
/ protected / << { / protected / << {
/ alg / 1: 10 / AES-CCM-16-64-128 / / alg / 1: 10 / AES-CCM-16-64-128 /
} >>, } >>,
/ unprotected / { / unprotected / {
/ kid / 4: h'53796d6d6574726963313238' / 'Symmetric128' /, / kid / 4: h'53796d6d6574726963313238' / 'Symmetric128' /,
/ iv / 5: h'99a0d7846e762c49ffe8a63e0b' / iv / 5: h'99a0d7846e762c49ffe8a63e0b'
}, },
/ ciphertext / h'b918a11fd81e438b7f973d9e2e119bcb22424ba0f38 / ciphertext / h'b918a11fd81e438b7f973d9e2e119bcb22424ba0f38
a80f27562f400ee1d0d6c0fdb559c02421fd384fc2e a80f27562f400ee1d0d6c0fdb559c02421fd384fc2e
be22d7071378b0ea7428fff157444d45f7e6afcda1a be22d7071378b0ea7428fff157444d45f7e6afcda1a
ae5f6495830c58627087fc5b4974f319a8707a635dd ae5f6495830c58627087fc5b4974f319a8707a635dd
643b' 643b'
] ]
) )
Figure 15: Encrypted CWT in CBOR diagnostic notation Figure 15: Encrypted CWT in CBOR Diagnostic Notation
A.6. Example Nested CWT A.6. Example Nested CWT
This section shows a Nested CWT, signed and then encrypted, with a This section shows a Nested CWT, signed and then encrypted, with a
single recipient and a full CWT Claims Set. single recipient and a full CWT Claims Set.
The signature is generated using the private ECDSA key from The signature is generated using the private ECDSA key from
Appendix A.2.3 and it can be validated using the public ECDSA parts Appendix A.2.3, and it can be validated using the public ECDSA parts
from Appendix A.2.3. The encryption is done with AES-CCM mode using from Appendix A.2.3. The encryption is done with AES-CCM mode using
the 128-bit symmetric key from Appendix A.2.1 with a 64-bit tag and the 128-bit symmetric key from Appendix A.2.1 with a 64-bit tag and
13-byte nonce, i.e., COSE AES-CCM-16-64-128. The content type is set 13-byte nonce, i.e., COSE AES-CCM-16-64-128. The content type is set
to CWT to indicate that there are multiple layers of COSE protection to CWT to indicate that there are multiple layers of COSE protection
before finding the CWT Claims Set. The decrypted ciphertext will be a before finding the CWT Claims Set. The decrypted ciphertext will be a
COSE_sign1 structure. In this example, it is the same one as in COSE_sign1 structure. In this example, it is the same one as in
Appendix A.3, i.e., a Signed CWT Claims Set. Note that there is no Appendix A.3, i.e., a Signed CWT Claims Set. Note that there is no
limitation to the number of layers; this is an example with two limitation to the number of layers; this is an example with two
layers. Line breaks are for display purposes only. layers. Line breaks are for display purposes only.
d08343a1010aa2044c53796d6d6574726963313238054d4a0694c0e69ee6b595 d08343a1010aa2044c53796d6d6574726963313238054d4a0694c0e69ee6b595
6655c7b258b7f6b0914f993de822cc47e5e57a188d7960b528a747446fe12f0e 6655c7b258b7f6b0914f993de822cc47e5e57a188d7960b528a747446fe12f0e
7de05650dec74724366763f167a29c002dfd15b34d8993391cf49bc91127f545 7de05650dec74724366763f167a29c002dfd15b34d8993391cf49bc91127f545
dba8703d66f5b7f1ae91237503d371e6333df9708d78c4fb8a8386c8ff09dc49 dba8703d66f5b7f1ae91237503d371e6333df9708d78c4fb8a8386c8ff09dc49
af768b23179deab78d96490a66d5724fb33900c60799d9872fac6da3bdb89043 af768b23179deab78d96490a66d5724fb33900c60799d9872fac6da3bdb89043
d67c2a05414ce331b5b8f1ed8ff7138f45905db2c4d5bc8045ab372bff142631 d67c2a05414ce331b5b8f1ed8ff7138f45905db2c4d5bc8045ab372bff142631
610a7e0f677b7e9b0bc73adefdcee16d9d5d284c616abeab5d8c291ce0 610a7e0f677b7e9b0bc73adefdcee16d9d5d284c616abeab5d8c291ce0
Figure 16: Signed and Encrypted CWT as hex string Figure 16: Signed and Encrypted CWT as Hex String
16( 16(
[ [
/ protected / << { / protected / << {
/ alg / 1: 10 / AES-CCM-16-64-128 / / alg / 1: 10 / AES-CCM-16-64-128 /
} >>, } >>,
/ unprotected / { / unprotected / {
/ kid / 4: h'53796d6d6574726963313238' / 'Symmetric128' /, / kid / 4: h'53796d6d6574726963313238' / 'Symmetric128' /,
/ iv / 5: h'4a0694c0e69ee6b5956655c7b2' / iv / 5: h'4a0694c0e69ee6b5956655c7b2'
}, },
skipping to change at page 22, line 26 skipping to change at page 23, line 26
fd15b34d8993391cf49bc91127f545dba8703d66f5b fd15b34d8993391cf49bc91127f545dba8703d66f5b
7f1ae91237503d371e6333df9708d78c4fb8a8386c8 7f1ae91237503d371e6333df9708d78c4fb8a8386c8
ff09dc49af768b23179deab78d96490a66d5724fb33 ff09dc49af768b23179deab78d96490a66d5724fb33
900c60799d9872fac6da3bdb89043d67c2a05414ce3 900c60799d9872fac6da3bdb89043d67c2a05414ce3
31b5b8f1ed8ff7138f45905db2c4d5bc8045ab372bf 31b5b8f1ed8ff7138f45905db2c4d5bc8045ab372bf
f142631610a7e0f677b7e9b0bc73adefdcee16d9d5d f142631610a7e0f677b7e9b0bc73adefdcee16d9d5d
284c616abeab5d8c291ce0' 284c616abeab5d8c291ce0'
] ]
) )
Figure 17: Signed and Encrypted CWT in CBOR diagnostic notation Figure 17: Signed and Encrypted CWT in CBOR Diagnostic Notation
A.7. Example MACed CWT with a floating-point value A.7. Example MACed CWT with a Floating-Point Value
This section shows a MACed CWT with a single recipient and a simple This section shows a MACed CWT with a single recipient and a simple
CWT Claims Set. The CWT Claims Set with a floating-point 'iat' value. CWT Claims Set. The CWT Claims Set with a floating-point 'iat' value.
The MAC is generated using the 256-bit symmetric key from The MAC is generated using the 256-bit symmetric key from
Appendix A.2.2 with a 64-bit truncation. Line breaks are for display Appendix A.2.2 with a 64-bit truncation. Line breaks are for display
purposes only. purposes only.
d18443a10104a1044c53796d6d65747269633235364ba106fb41d584367c2000 d18443a10104a1044c53796d6d65747269633235364ba106fb41d584367c2000
0048b8816f34c0542892 0048b8816f34c0542892
Figure 18: MACed CWT with a floating-point value as hex string Figure 18: MACed CWT with a Floating-Point Value as Hex String
17( 17(
[ [
/ protected / << { / protected / << {
/ alg / 1: 4 / HMAC-256-64 / / alg / 1: 4 / HMAC-256-64 /
} >>, } >>,
/ unprotected / { / unprotected / {
/ kid / 4: h'53796d6d6574726963323536' / 'Symmetric256' /, / kid / 4: h'53796d6d6574726963323536' / 'Symmetric256' /,
}, },
/ payload / << { / payload / << {
/ iat / 6: 1443944944.5 / iat / 6: 1443944944.5
} >>, } >>,
/ tag / h'b8816f34c0542892' / tag / h'b8816f34c0542892'
] ]
) )
Figure 19: MACed CWT with a floating-point value in CBOR diagnostic Figure 19: MACed CWT with a Floating-Point Value
notation in CBOR Diagnostic Notation
Appendix B. Acknowledgements Acknowledgements
This specification is based on JSON Web Token (JWT) [RFC7519], the This specification is based on JSON Web Token (JWT) [RFC7519], the
authors of which also include Nat Sakimura and John Bradley. It also authors of which also include Nat Sakimura and John Bradley. It also
incorporates suggestions made by many people, including Carsten incorporates suggestions made by many people, including Carsten
Bormann, Alissa Cooper, Esko Dijk, Benjamin Kaduk, Warren Kumari, Bormann, Alissa Cooper, Esko Dijk, Benjamin Kaduk, Warren Kumari,
Carlos Martinez, Alexey Melnikov, Kathleen Moriarty, Eric Rescorla, Carlos Martinez, Alexey Melnikov, Kathleen Moriarty, Eric Rescorla,
Dan Romascanu, Adam Roach, Kyle Rose, Jim Schaad, Ludwig Seitz, and Dan Romascanu, Adam Roach, Kyle Rose, Jim Schaad, Ludwig Seitz, and
Goeran Selander. Goeran Selander.
[[ RFC Editor: Is it possible to preserve the non-ASCII spellings of
the names Erik Wahlstroem and Goeran Selander in the final
specification? ]]
Appendix C. Document History
[[ to be removed by the RFC Editor before publication as an RFC ]]
-15
o Added section references when the terms "NumericDate" and
"StringOrURI" are used, as suggested by Adam Roach.
-14
o Cleaned up the descriptions of the numeric ranges of claim keys
being registered in the registration template for the "CBOR Web
Token (CWT) Claims" registry, as suggested by Adam Roach.
o Clarified the relationships between the JWT and CWT "NumericDate"
and "StringOrURI" terms, as suggested by Adam Roach.
o Eliminated unnecessary uses of the word "type", as suggested by
Adam Roach.
o Added the text "IANA must only accept registry updates from the
Designated Experts and should direct all requests for registration
to the review mailing list" from RFC 7519, as suggested by Amanda
Baber of IANA, which is also intended to address Alexey Melnikov's
comment.
o Removed a superfluous comma, as suggested by Warren Kumari.
o Acknowledged additional reviewers.
-13
o Clarified the registration criteria applied to different ranges of
Claim Key values, as suggested by Kathleen Moriarty and Dan
Romascanu.
o No longer describe the syntax of CWT claims as being the same as
that of the corresponding JWT claims, as suggested by Kyle Rose.
o Added guidance about the selection of the Designated Experts, as
suggested by Benjamin Kaduk.
o Acknowledged additional reviewers.
-12
o Updated the RFC 5226 reference to RFC 8126.
o Made the IANA registration criteria consistent across sections.
o Stated that registrations for the limited set of values between
-256 and 255 and strings of length 1 are to be restricted to
claims with general applicability.
o Changed the "Reference" field name to "Description of Semantics"
in the CBOR Tag registration request.
o Asked the RFC Editor whether it is possible to preserve the non-
ASCII spellings of the names Erik Wahlstroem and Goeran Selander
in the final specification.
-11
o Corrected the "iv" value in the signed and encrypted CWT example.
o Mention CoAP in the "application/cwt" media type registration.
o Changed references of the form "Section 4.1.1 of JWT <xref
target="RFC7519"/>" to "Section 4.1.1 of <xref target="RFC7519"/>"
so that rfcmarkup will generate correct external section reference
links.
o Updated Acknowledgements.
-10
o Clarified that the audience claim value can be a single audience
value or an array of audience values, just as is the case for the
JWT "aud" claim.
o Clarified the nested CWT description.
o Changed uses of "binary string" to "byte string".
-09
o Added key ID values to the examples.
o Key values for the examples are now represented in COSE_Key format
using CBOR diagnostic notation.
-08
o Updated the diagnostic notation for embedded objects in the
examples, addressing feedback by Carsten Bormann.
-07
o Updated examples for signing and encryption. Signatures are now
deterministic as recommended by COSE specification.
-06
o Addressed review comments by Carsten Bormann and Jim Schaad. All
changes were editorial in nature.
-05
o Addressed working group last call comments with the following
changes:
o Say that CWT is derived from JWT, rather than CWT is a profile of
JWT.
o Used CBOR type names in descriptions, rather than major/minor type
numbers.
o Clarified the NumericDate and StringOrURI descriptions.
o Changed to allow CWT claim names to use values of any legal CBOR
map key type.
o Changed to use the CWT tag to identify nested CWTs instead of the
CWT content type.
o Added an example using a floating-point date value.
o Acknowledged reviewers.
-04
o Specified that the use of CBOR tags to prefix any of the claim
values defined in this specification is NOT RECOMMENDED.
-03
o Reworked the examples to include signed, MACed, encrypted, and
nested CWTs.
o Defined the CWT CBOR tag and explained its usage.
-02
o Added IANA registration for the application/cwt media type.
o Clarified the nested CWT language.
o Corrected nits identified by Ludwig Seitz.
-01
o Added IANA registration for CWT Claims.
o Added IANA registration for the application/cwt CoAP content-
format type.
o Added Samuel Erdtman as an editor.
o Changed Erik's e-mail address.
-00
o Created the initial working group version based on draft-
wahlstroem-ace-cbor-web-token-00.
Authors' Addresses Authors' Addresses
Michael B. Jones Michael B. Jones
Microsoft Microsoft
Email: mbj@microsoft.com Email: mbj@microsoft.com
URI: http://self-issued.info/ URI: http://self-issued.info/
Erik Wahlstroem Erik Wahlstroem
Sweden Sweden
 End of changes. 86 change blocks. 
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