< draft-ietf-ace-cwt-proof-of-possession-02.txt   draft-ietf-ace-cwt-proof-of-possession-03.txt >
ACE Working Group M. Jones ACE M. Jones
Internet-Draft Microsoft Internet-Draft Microsoft
Intended status: Standards Track L. Seitz Intended status: Standards Track L. Seitz
Expires: September 4, 2018 RISE SICS Expires: December 31, 2018 RISE SICS
G. Selander G. Selander
Ericsson AB Ericsson AB
E. Wahlstroem
S. Erdtman S. Erdtman
Spotify AB Spotify
H. Tschofenig H. Tschofenig
ARM Ltd. ARM Ltd.
March 3, 2018 June 29, 2018
Proof-of-Possession Key Semantics for CBOR Web Tokens (CWTs) Proof-of-Possession Key Semantics for CBOR Web Tokens (CWTs)
draft-ietf-ace-cwt-proof-of-possession-02 draft-ietf-ace-cwt-proof-of-possession-03
Abstract Abstract
This specification describes how to declare in a CBOR Web Token (CWT) This specification describes how to declare in a CBOR Web Token (CWT)
that the presenter of the CWT possesses a particular proof-of- that the presenter of the CWT possesses a particular proof-of-
possession key. Being able to prove possession of a key is also possession key. Being able to prove possession of a key is also
sometimes described as being the holder-of-key. This specification sometimes described as being the holder-of-key. This specification
provides equivalent functionality to "Proof-of-Possession Key provides equivalent functionality to "Proof-of-Possession Key
Semantics for JSON Web Tokens (JWTs)" (RFC 7800), but using CBOR and Semantics for JSON Web Tokens (JWTs)" (RFC 7800), but using CBOR and
CWTs rather than JSON and JWTs. CWTs rather than JSON and JWTs.
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Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
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working documents as Internet-Drafts. The list of current Internet- working documents as Internet-Drafts. The list of current Internet-
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Internet-Drafts are draft documents valid for a maximum of six months Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any and may be updated, replaced, or obsoleted by other documents at any
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 September 4, 2018. This Internet-Draft will expire on December 31, 2018.
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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described in the Simplified BSD License. described in the Simplified BSD License.
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1. Notational Conventions . . . . . . . . . . . . . . . . . 3
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. Representations for Proof-of-Possession Keys . . . . . . . . 3 3. Representations for Proof-of-Possession Keys . . . . . . . . 3
3.1. Confirmation Claim . . . . . . . . . . . . . . . . . . . 4 3.1. Confirmation Claim . . . . . . . . . . . . . . . . . . . 4
3.2. Representation of an Asymmetric Proof-of-Possession Key . 5 3.2. Representation of an Asymmetric Proof-of-Possession Key . 5
3.3. Representation of an Encrypted Symmetric Proof-of- 3.3. Representation of an Encrypted Symmetric Proof-of-
Possession Key . . . . . . . . . . . . . . . . . . . . . 6 Possession Key . . . . . . . . . . . . . . . . . . . . . 5
3.4. Representation of a Key ID for a Proof-of-Possession Key 7 3.4. Representation of a Key ID for a Proof-of-Possession Key 6
3.5. Specifics Intentionally Not Specified . . . . . . . . . . 7 3.5. Specifics Intentionally Not Specified . . . . . . . . . . 7
4. Security Considerations . . . . . . . . . . . . . . . . . . . 8 4. Security Considerations . . . . . . . . . . . . . . . . . . . 7
5. Privacy Considerations . . . . . . . . . . . . . . . . . . . 9 5. Privacy Considerations . . . . . . . . . . . . . . . . . . . 8
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 9 6. Operational Considerations . . . . . . . . . . . . . . . . . 8
6.1. CBOR Web Token Claims Registration . . . . . . . . . . . 9 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 9
6.1.1. Registry Contents . . . . . . . . . . . . . . . . . . 10 7.1. CBOR Web Token Claims Registration . . . . . . . . . . . 10
6.2. CWT Confirmation Methods Registry . . . . . . . . . . . . 10 7.1.1. Registry Contents . . . . . . . . . . . . . . . . . . 10
6.2.1. Registration Template . . . . . . . . . . . . . . . . 10 7.2. CWT Confirmation Methods Registry . . . . . . . . . . . . 10
6.2.2. Initial Registry Contents . . . . . . . . . . . . . . 11 7.2.1. Registration Template . . . . . . . . . . . . . . . . 10
7. References . . . . . . . . . . . . . . . . . . . . . . . . . 11 7.2.2. Initial Registry Contents . . . . . . . . . . . . . . 11
7.1. Normative References . . . . . . . . . . . . . . . . . . 11 8. References . . . . . . . . . . . . . . . . . . . . . . . . . 11
7.2. Informative References . . . . . . . . . . . . . . . . . 12 8.1. Normative References . . . . . . . . . . . . . . . . . . 11
8.2. Informative References . . . . . . . . . . . . . . . . . 12
Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . 13 Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . 13
Document History . . . . . . . . . . . . . . . . . . . . . . . . 13 Document History . . . . . . . . . . . . . . . . . . . . . . . . 13
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 14 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 14
1. Introduction 1. Introduction
This specification describes how a CBOR Web Token [CWT] can declare This specification describes how a CBOR Web Token (CWT) [RFC8392] can
that the presenter of the CWT possesses a particular proof-of- declare that the presenter of the CWT possesses a particular proof-
possession (PoP) key. Proof of possession of a key is also sometimes of-possession (PoP) key. Proof of possession of a key is also
described as being the holder-of-key. This specification provides sometimes described as being the holder-of-key. This specification
equivalent functionality to "Proof-of-Possession Key Semantics for provides equivalent functionality to "Proof-of-Possession Key
JSON Web Tokens (JWTs)" [RFC7800], but using CBOR [RFC7049] and CWTs Semantics for JSON Web Tokens (JWTs)" [RFC7800], but using CBOR
[CWT] rather than JSON [RFC7159] and JWTs [JWT]. [RFC7049] and CWTs [RFC8392] rather than JSON [RFC7159] and JWTs
[JWT].
1.1. Notational Conventions 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 BCP
14 [RFC2119] [RFC8174] when, and only when, they appear in all 14 [RFC2119] [RFC8174] when, and only when, they appear in all
capitals, as shown here. capitals, as shown here.
Unless otherwise noted, all the protocol parameter names and values This specification uses terms defined in the CBOR Web Token (CWT)
are case sensitive. [RFC8392], CBOR Object Signing and Encryption (COSE) [RFC8152], and
Concise Binary Object Representation (CBOR) [RFC7049] specifications.
2. Terminology
This specification uses terms defined in the CBOR Web Token [CWT],
CBOR Object Signing and Encryption (COSE) [RFC8152], and Concise
Binary Object Representation (CBOR) [RFC7049] specifications.
These terms are defined by this specification: These terms are defined by this specification:
Issuer Issuer
Party that creates the CWT and binds its claims to the proof-of- Party that creates the CWT and binds the claims about the subject
possession key. to the proof-of-possession key.
Presenter Presenter
Party that proves possession of a private key (for asymmetric key Party that proves possession of a private key (for asymmetric key
cryptography) or secret key (for symmetric key cryptography) to a cryptography) or secret key (for symmetric key cryptography) to a
recipient. recipient.
In context of OAuth this party is also called OAuth Client.
Recipient Recipient
Party that receives the CWT containing the proof-of-possession key Party that receives the CWT containing the proof-of-possession key
information from the presenter. information from the presenter.
In context of OAuth this party is also called OAuth Resource
Server.
3. Representations for Proof-of-Possession Keys 3. Representations for Proof-of-Possession Keys
By including a "cnf" (confirmation) claim in a CWT, the issuer of the By including a "cnf" (confirmation) claim in a CWT, the issuer of the
CWT declares that the presenter possesses a particular key and that CWT declares that the presenter possesses a particular key and that
the recipient can cryptographically confirm that the presenter has the recipient can cryptographically confirm that the presenter has
possession of that key. The value of the "cnf" claim is a CBOR map possession of that key. The value of the "cnf" claim is a CBOR map
and the members of that map identify the proof-of-possession key. and the members of that map identify the proof-of-possession key.
The presenter can be identified in one of several ways by the CWT The presenter can be identified in one of several ways by the CWT,
depending upon the application requirements. If the CWT contains a depending upon the application requirements. For instance, some
"sub" (subject) claim [CWT], the presenter is normally the subject applications may use the CWT "sub" (subject) claim [RFC8392], to
identified by the CWT. (In some applications, the subject identifier identify the presenter. Other applications may use the "iss" claim
will be relative to the issuer identified by the "iss" (issuer) claim to identify the presenter. In some applications, the subject
[CWT].) If the CWT contains no "sub" claim, the presenter is identifier might be relative to the issuer identified by the "iss"
normally the issuer identified by the CWT using the "iss" claim. The (issuer) claim [RFC8392]. The actual mechanism used is dependent
case in which the presenter is the subject of the CWT is analogous to upon the application. The case in which the presenter is the subject
Security Assertion Markup Language (SAML) 2.0 of the CWT is analogous to Security Assertion Markup Language (SAML)
[OASIS.saml-core-2.0-os] SubjectConfirmation usage. At least one of 2.0 [OASIS.saml-core-2.0-os] SubjectConfirmation usage.
the "sub" and "iss" claims is typically present in the CWT and some
use cases may require that both be present.
3.1. Confirmation Claim 3.1. Confirmation Claim
The "cnf" claim is used in the CWT to contain members used to The "cnf" claim in the CWT is used to carry confirmation methods.
identify the proof-of-possession key. Other members of the "cnf" map Some of them use proof-of-possession keys while others do not. This
may be defined because a proof-of-possession key may not be the only design is analogous to the SAML 2.0 [OASIS.saml-core-2.0-os]
means of confirming the authenticity of the token. This is analogous SubjectConfirmation element in which a number of different subject
to the SAML 2.0 [OASIS.saml-core-2.0-os] SubjectConfirmation element confirmation methods can be included (including proof-of-possession
in which a number of different subject confirmation methods can be key information).
included (including proof-of-possession key information).
The set of confirmation members that a CWT must contain to be The set of confirmation members that a CWT must contain to be
considered valid is context dependent and is outside the scope of considered valid is context dependent and is outside the scope of
this specification. Specific applications of CWTs will require this specification. Specific applications of CWTs will require
implementations to understand and process some confirmation members implementations to understand and process some confirmation members
in particular ways. However, in the absence of such requirements, in particular ways. However, in the absence of such requirements,
all confirmation members that are not understood by implementations all confirmation members that are not understood by implementations
MUST be ignored. MUST be ignored.
This specification establishes the IANA "CWT Confirmation Methods" This specification establishes the IANA "CWT Confirmation Methods"
registry for these members in Section 6.2 and registers the members registry for these members in Section 7.2 and registers the members
defined by this specification. Other specifications can register defined by this specification. Other specifications can register
other members used for confirmation, including other members for other members used for confirmation, including other members for
conveying proof-of-possession keys using different key conveying proof-of-possession keys using different key
representations. representations.
The "cnf" claim value MUST represent only a single proof-of- The "cnf" claim value MUST represent only a single proof-of-
possession key. At most one of the "COSE_Key" and possession key. At most one of the "COSE_Key" and
"Encrypted_COSE_Key" confirmation values defined below may be "Encrypted_COSE_Key" confirmation values defined in Figure 1 may be
present. Note that if an application needs to represent multiple present. Note that if an application needs to represent multiple
proof-of-possession keys in the same CWT, one way for it to achieve proof-of-possession keys in the same CWT, one way for it to achieve
this is to use other claim names, in addition to "cnf", to hold the this is to use other claim names, in addition to "cnf", to hold the
additional proof-of-possession key information. These claims could additional proof-of-possession key information. These claims could
use the same syntax and semantics as the "cnf" claim. Those claims use the same syntax and semantics as the "cnf" claim. Those claims
would be defined by applications or other specifications and could be would be defined by applications or other specifications and could be
registered in the IANA "CBOR Web Token Claims" registry registered in the IANA "CBOR Web Token Claims" registry
[IANA.CWT.Claims]. [IANA.CWT.Claims].
/--------------------+-----+-------------------------------\ /--------------------+-----+-------------------------------\
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| kid | 3 | binary string | | kid | 3 | binary string |
\--------------------+-----+-------------------------------/ \--------------------+-----+-------------------------------/
Figure 1: Summary of the cnf names, keys, and value types Figure 1: Summary of the cnf names, keys, and value types
3.2. Representation of an Asymmetric Proof-of-Possession Key 3.2. Representation of an Asymmetric Proof-of-Possession Key
When the key held by the presenter is an asymmetric private key, the When the key held by the presenter is an asymmetric private key, the
"COSE_Key" member is a COSE_Key [RFC8152] representing the "COSE_Key" member is a COSE_Key [RFC8152] representing the
corresponding asymmetric public key. The following example (using corresponding asymmetric public key. The following example (using
CBOR diagonstic notation) demonstrates such a declaration in the CWT CBOR diagnostic notation) demonstrates such a declaration in the CWT
Claims Set of a CWT: Claims Set of a CWT:
{ {
/iss/ 1 : "coaps://server.example.com", /iss/ 1 : "coaps://server.example.com",
/aud/ 3 : "coaps://client.example.org", /aud/ 3 : "coaps://client.example.org",
/exp/ 4 : 1361398824, /exp/ 4 : 1361398824,
/cnf/ 8 :{ /cnf/ 8 :{
/COSE_Key/ 1 :{ /COSE_Key/ 1 :{
/kty/ 1 : /EC/ 2, /kty/ 1 : /EC/ 2,
/crv/ -1 : /P-256/ 1, /crv/ -1 : /P-256/ 1,
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} }
} }
The COSE_Key MUST contain the required key members for a COSE_Key of The COSE_Key MUST contain the required key members for a COSE_Key of
that key type and MAY contain other COSE_Key members, including the that key type and MAY contain other COSE_Key members, including the
"kid" (Key ID) member. "kid" (Key ID) member.
The "COSE_Key" member MAY also be used for a COSE_Key representing a The "COSE_Key" member MAY also be used for a COSE_Key representing a
symmetric key, provided that the CWT is encrypted so that the key is symmetric key, provided that the CWT is encrypted so that the key is
not revealed to unintended parties. The means of encrypting a CWT is not revealed to unintended parties. The means of encrypting a CWT is
explained in [CWT]. If the CWT is not encrypted, the symmetric key explained in [RFC8392]. If the CWT is not encrypted, the symmetric
MUST be encrypted as described below. key MUST be encrypted as described in Section 3.3.
3.3. Representation of an Encrypted Symmetric Proof-of-Possession Key 3.3. Representation of an Encrypted Symmetric Proof-of-Possession Key
When the key held by the presenter is a symmetric key, the When the key held by the presenter is a symmetric key, the
"Encrypted_COSE_Key" member is an encrypted COSE_Key [RFC8152] "Encrypted_COSE_Key" member is an encrypted COSE_Key [RFC8152]
representing the symmetric key encrypted to a key known to the representing the symmetric key encrypted to a key known to the
recipient using COSE_Encrypt or COSE_Encrypt0. recipient using COSE_Encrypt or COSE_Encrypt0.
The following example (using CBOR diagnostic notation, with The following example (using CBOR diagnostic notation, with
linebreaks for readability) illustrates a symmetric key that could linebreaks for readability) illustrates a symmetric key that could
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protocols will communicate this information in different ways. protocols will communicate this information in different ways.
Likewise, the means of communicating the signed nonce is also not Likewise, the means of communicating the signed nonce is also not
specified, as this is also protocol specific. specified, as this is also protocol specific.
Note that another means of proving possession of the key when it is a Note that another means of proving possession of the key when it is a
symmetric key is to encrypt the key to the recipient. The means of symmetric key is to encrypt the key to the recipient. The means of
obtaining a key for the recipient is likewise protocol specific. obtaining a key for the recipient is likewise protocol specific.
4. Security Considerations 4. Security Considerations
All of the security considerations that are discussed in [CWT] also All of the security considerations that are discussed in [RFC8392]
apply here. In addition, proof of possession introduces its own also apply here. In addition, proof of possession introduces its own
unique security issues. Possessing a key is only valuable if it is unique security issues. Possessing a key is only valuable if it is
kept secret. Appropriate means must be used to ensure that kept secret. Appropriate means must be used to ensure that
unintended parties do not learn private key or symmetric key values. unintended parties do not learn private key or symmetric key values.
Applications utilizing proof of possession should also utilize Applications utilizing proof of possession SHOULD also utilize
audience restriction, as described in Section 4.1.3 of [JWT], as it audience restriction, as described in Section 4.1.3 of [JWT], as it
provides different protections. Proof of possession can be used by provides additional protections. Proof of possession can be used by
recipients to reject messages from unauthorized senders. Audience recipients to reject messages from unauthorized senders. Audience
restriction can be used by recipients to reject messages intended for restriction can be used by recipients to reject messages intended for
different recipients. different recipients.
A recipient might not understand the "cnf" claim. Applications that A recipient might not understand the "cnf" claim. Applications that
require the proof-of-possession keys communicated with it to be require the proof-of-possession keys communicated with it to be
understood and processed must ensure that the parts of this understood and processed MUST ensure that the parts of this
specification that they use are implemented. specification that they use are implemented.
Proof of possession via encrypted symmetric secrets is subject to CBOR Web Tokens with proof-of-possession keys are used in context of
replay attacks. This attack can, for example, be avoided when a an architecture, such as the ACE OAuth Framework
signed nonce or challenge is used since the recipient can use a [I-D.ietf-ace-oauth-authz], in which protocols are used by a
distinct nonce or challenge for each interaction. Replay can also be presenter to request these tokens and to subsequently use them with
avoided if a sub-key is derived from a shared secret that is specific recipients. To avoid replay attacks when the proof-of-possession
to the instance of the PoP demonstration. tokens are sent to presenters, a security protocol, which uses
mechansims such as nonces or timestamps, has to be utilized. Note
that a discussion of the architecture or specific protocols that CWT
proof-of-possession tokens are used with is beyond the scope of this
specification.
As is the case with other information included in a CWT, it is As is the case with other information included in a CWT, it is
necessary to apply data origin authentication and integrity necessary to apply data origin authentication and integrity
protection (via a keyed message digest or a digital signature). Data protection (via a keyed message digest or a digital signature). Data
origin authentication ensures that the recipient of the CWT learns origin authentication ensures that the recipient of the CWT learns
about the entity that created the CWT since this will be important about the entity that created the CWT since this will be important
for any policy decisions. Integrity protection prevents an adversary for any policy decisions. Integrity protection prevents an adversary
from changing any elements conveyed within the CWT payload. Special from changing any elements conveyed within the CWT payload. Special
care has to be applied when carrying symmetric keys inside the CWT care has to be applied when carrying symmetric keys inside the CWT
since those not only require integrity protection but also since those not only require integrity protection but also
confidentiality protection. confidentiality protection.
As described in Section 6 (Key Identification) and Appendix D (Notes As described in Section 6 (Key Identification) and Appendix D (Notes
on Key Selection) of [JWS], it is important to make explicit trust on Key Selection) of [JWS], it is important to make explicit trust
decisions about the keys. Proof-of-possession signatures made with decisions about the keys. Proof-of-possession signatures made with
keys not meeting the application's trust criteria MUST NOT not be keys not meeting the application's trust criteria MUST NOT be relied
relied upon. upon.
5. Privacy Considerations 5. Privacy Considerations
A proof-of-possession key can be used as a correlation handle if the A proof-of-possession key can be used as a correlation handle if the
same key is used with multiple parties. Thus, for privacy reasons, same key is used with multiple parties. Thus, for privacy reasons,
it is recommended that different proof-of-possession keys be used it is recommended that different proof-of-possession keys be used
when interacting with different parties. when interacting with different parties.
6. IANA Considerations 6. Operational Considerations
The use of CWTs with proof-of-possession keys requires additional
information to be shared between the involved parties in order to
ensure correct processing. The recipient needs to be able to use
credentials to verify the authenticity, integrity, and potentially
the confidentiality of the CWT and its content. This requires the
recipient to know information about the issuer. Likewise, there
needs to be agreement between the issuer and the recipient about the
claims being used (which is also true of CWTs in general).
When an issuer creates a CWT containing a Key ID claim, it needs to
make sure that it does not issue another CWT containing the same Key
ID with a different content, or for a different subject, within the
lifetime of the CWTs, unless intentionally desired. Failure to do so
may allow one party to impersonate another party, with the potential
to gain additional privileges. Likewise, if PoP keys are used for
multiple different kinds of CWTs in an application and the PoP keys
are identified by Key IDs, care must be taken to keep the keys for
the different kinds of CWTs segregated so that an attacker cannot
cause the wrong PoP key to be used by using a valid Key ID for the
wrong kind of CWT.
7. IANA Considerations
The following registration procedure is used for all the registries The following registration procedure is used for all the registries
established by this specification. established by this specification.
Values are registered on a Specification Required [RFC5226] basis Values are registered on a Specification Required [RFC5226] basis
after a three-week review period on the cwt-reg-review@ietf.org after a three-week review period on the cwt-reg-review@ietf.org
mailing list, on the advice of one or more Designated Experts. mailing list, on the advice of one or more Designated Experts.
However, to allow for the allocation of values prior to publication, However, to allow for the allocation of values prior to publication,
the Designated Experts may approve registration once they are the Designated Experts may approve registration once they are
satisfied that such a specification will be published. [[ Note to satisfied that such a specification will be published. [[ Note to
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and whether the registration makes sense. and whether the registration makes sense.
It is suggested that multiple Designated Experts be appointed who are It is suggested that multiple Designated Experts be appointed who are
able to represent the perspectives of different applications using able to represent the perspectives of different applications using
this specification in order to enable broadly informed review of this specification in order to enable broadly informed review of
registration decisions. In cases where a registration decision could registration decisions. In cases where a registration decision could
be perceived as creating a conflict of interest for a particular be perceived as creating a conflict of interest for a particular
Expert, that Expert should defer to the judgment of the other Expert, that Expert should defer to the judgment of the other
Experts. Experts.
6.1. CBOR Web Token Claims Registration 7.1. CBOR Web Token Claims Registration
This specification registers the "cnf" claim in the IANA "CBOR Web This specification registers the "cnf" claim in the IANA "CBOR Web
Token Claims" registry [IANA.CWT.Claims] established by [CWT]. Token Claims" registry [IANA.CWT.Claims] established by [RFC8392].
6.1.1. Registry Contents 7.1.1. Registry Contents
o Claim Name: "cnf" o Claim Name: "cnf"
o Claim Description: Confirmation o Claim Description: Confirmation
o JWT Claim Name: "cnf" o JWT Claim Name: "cnf"
o Claim Key: TBD (maybe 8) o Claim Key: TBD (maybe 8)
o Claim Value Type(s): map o Claim Value Type(s): map
o Change Controller: IESG o Change Controller: IESG
o Specification Document(s): Section 3.1 of [[ this document ]] o Specification Document(s): Section 3.1 of [[ this document ]]
6.2. CWT Confirmation Methods Registry 7.2. CWT Confirmation Methods Registry
This specification establishes the IANA "CWT Confirmation Methods" This specification establishes the IANA "CWT Confirmation Methods"
registry for CWT "cnf" member values. The registry records the registry for CWT "cnf" member values. The registry records the
confirmation method member and a reference to the specification that confirmation method member and a reference to the specification that
defines it. defines it.
6.2.1. Registration Template 7.2.1. Registration Template
Confirmation Method Name: Confirmation Method Name:
The human-readable name requested (e.g., "kid"). The human-readable name requested (e.g., "kid").
Confirmation Method Description: Confirmation Method Description:
Brief description of the confirmation method (e.g., "Key Brief description of the confirmation method (e.g., "Key
Identifier"). Identifier").
JWT Confirmation Method Name: JWT Confirmation Method Name:
Claim Name of the equivalent JWT confirmation method value, as Claim Name of the equivalent JWT confirmation method value, as
skipping to change at page 10, line 45 skipping to change at page 11, line 4
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".
Confirmation Key: Confirmation Key:
CBOR map key value for the confirmation method. CBOR map key value for the confirmation method.
Confirmation Value Type(s): Confirmation Value Type(s):
CBOR types that can be used for the confirmation method value. CBOR types that can be used for the confirmation method 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):
Reference to the document or documents that specify the parameter, Reference to the document or documents that specify the parameter,
preferably including URIs that can be used to retrieve copies of preferably including URIs that can be used to retrieve copies of
the documents. An indication of the relevant sections may also be the documents. An indication of the relevant sections may also be
included but is not required. included but is not required.
6.2.2. Initial Registry Contents 7.2.2. Initial Registry Contents
o Confirmation Method Name: "COSE_Key" o Confirmation Method Name: "COSE_Key"
o Confirmation Method Description: COSE_Key Representing Public Key o Confirmation Method Description: COSE_Key Representing Public Key
o JWT Confirmation Method Name: "jwk" o JWT Confirmation Method Name: "jwk"
o Confirmation Key: 1 o Confirmation Key: 1
o Confirmation Value Type(s): map o Confirmation Value Type(s): map
o Change Controller: IESG o Change Controller: IESG
o Specification Document(s): Section 3.2 of [[ this document ]] o Specification Document(s): Section 3.2 of [[ this document ]]
o Confirmation Method Name: "Encrypted_COSE_Key" o Confirmation Method Name: "Encrypted_COSE_Key"
skipping to change at page 11, line 34 skipping to change at page 11, line 42
o Specification Document(s): Section 3.3 of [[ this document ]] o Specification Document(s): Section 3.3 of [[ this document ]]
o Confirmation Method Name: "kid" o Confirmation Method Name: "kid"
o Confirmation Method Description: Key Identifier o Confirmation Method Description: Key Identifier
o JWT Confirmation Method Name: "kid" o JWT Confirmation Method Name: "kid"
o Confirmation Key: 3 o Confirmation Key: 3
o Confirmation Value Type(s): binary string o Confirmation Value Type(s): binary string
o Change Controller: IESG o Change Controller: IESG
o Specification Document(s): Section 3.4 of [[ this document ]] o Specification Document(s): Section 3.4 of [[ this document ]]
7. References 8. References
7.1. Normative References
[CWT] Jones, M., Wahlstroem, E., Erdtman, S., and H. Tschofenig, 8.1. Normative References
"CBOR Web Token (CWT)", Work in Progress, draft-ietf-ace-
cbor-web-token-11, January 2018,
<https://tools.ietf.org/html/
draft-ietf-ace-cbor-web-token-11>.
[IANA.CWT.Claims] [IANA.CWT.Claims]
IANA, "CBOR Web Token Claims", IANA, "CBOR Web Token Claims",
<http://www.iana.org/assignments/cwt>. <http://www.iana.org/assignments/cwt>.
[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>.
[RFC3629] Yergeau, F., "UTF-8, a transformation format of ISO
10646", STD 63, RFC 3629, DOI 10.17487/RFC3629, November
2003, <https://www.rfc-editor.org/info/rfc3629>.
[RFC3986] Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform
Resource Identifier (URI): Generic Syntax", STD 66,
RFC 3986, DOI 10.17487/RFC3986, January 2005,
<https://www.rfc-editor.org/info/rfc3986>.
[RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an [RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an
IANA Considerations Section in RFCs", RFC 5226, IANA Considerations Section in RFCs", RFC 5226,
DOI 10.17487/RFC5226, May 2008, DOI 10.17487/RFC5226, May 2008,
<https://www.rfc-editor.org/info/rfc5226>. <https://www.rfc-editor.org/info/rfc5226>.
[RFC5246] Dierks, T. and E. Rescorla, "The Transport Layer Security
(TLS) Protocol Version 1.2", RFC 5246,
DOI 10.17487/RFC5246, August 2008,
<https://www.rfc-editor.org/info/rfc5246>.
[RFC6125] Saint-Andre, P. and J. Hodges, "Representation and
Verification of Domain-Based Application Service Identity
within Internet Public Key Infrastructure Using X.509
(PKIX) Certificates in the Context of Transport Layer
Security (TLS)", RFC 6125, DOI 10.17487/RFC6125, March
2011, <https://www.rfc-editor.org/info/rfc6125>.
[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>.
[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/info/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/info/rfc8174>. May 2017, <https://www.rfc-editor.org/info/rfc8174>.
7.2. Informative References [RFC8392] Jones, M., Wahlstroem, E., Erdtman, S., and H. Tschofenig,
"CBOR Web Token (CWT)", RFC 8392, DOI 10.17487/RFC8392,
May 2018, <https://www.rfc-editor.org/info/rfc8392>.
8.2. Informative References
[I-D.ietf-ace-oauth-authz]
Seitz, L., Selander, G., Wahlstroem, E., Erdtman, S., and
H. Tschofenig, "Authentication and Authorization for
Constrained Environments (ACE) using the OAuth 2.0
Framework (ACE-OAuth)", draft-ietf-ace-oauth-authz-12
(work in progress), May 2018.
[IANA.JWT.Claims] [IANA.JWT.Claims]
IANA, "JSON Web Token Claims", IANA, "JSON Web Token Claims",
<http://www.iana.org/assignments/jwt>. <http://www.iana.org/assignments/jwt>.
[JWS] Jones, M., Bradley, J., and N. Sakimura, "JSON Web [JWS] Jones, M., Bradley, J., and N. Sakimura, "JSON Web
Signature (JWS)", RFC 7515, May 2015, Signature (JWS)", RFC 7515, May 2015,
<http://www.rfc-editor.org/info/rfc7515>. <http://www.rfc-editor.org/info/rfc7515>.
[JWT] Jones, M., Bradley, J., and N. Sakimura, "JSON Web Token [JWT] Jones, M., Bradley, J., and N. Sakimura, "JSON Web Token
skipping to change at page 13, line 28 skipping to change at page 13, line 24
2014, <https://www.rfc-editor.org/info/rfc7159>. 2014, <https://www.rfc-editor.org/info/rfc7159>.
[RFC7800] Jones, M., Bradley, J., and H. Tschofenig, "Proof-of- [RFC7800] Jones, M., Bradley, J., and H. Tschofenig, "Proof-of-
Possession Key Semantics for JSON Web Tokens (JWTs)", Possession Key Semantics for JSON Web Tokens (JWTs)",
RFC 7800, DOI 10.17487/RFC7800, April 2016, RFC 7800, DOI 10.17487/RFC7800, April 2016,
<https://www.rfc-editor.org/info/rfc7800>. <https://www.rfc-editor.org/info/rfc7800>.
Acknowledgements Acknowledgements
Thanks to the following people for their reviews of the Thanks to the following people for their reviews of the
specification: Michael Richardson and Jim Schaad. specification: Roman Danyliw, Michael Richardson, and Jim Schaad.
Ludwig Seitz and Goeran Selander worked on this document as part of
the CelticPlus project CyberWI, with funding from Vinnova.
Document History Document History
[[ to be removed by the RFC Editor before publication as an RFC ]] [[ to be removed by the RFC Editor before publication as an RFC ]]
-03
o Addressed review comments by Jim Schaad, see https://www.ietf.org/
mail-archive/web/ace/current/msg02798.html
o Removed unnecessary sentence in the introduction regarding the use
any strings that could be case-sensitive.
o Clarified the terms Presenter and Recipient.
o Clarified text about the confirmation claim.
-02 -02
o Changed "typically" to "often" when describing ways of performing o Changed "typically" to "often" when describing ways of performing
proof of possession. proof of possession.
o Changed b64 to hex encoding in an example. o Changed b64 to hex encoding in an example.
o Changed to using the RFC 8174 boilerplate instead of the RFC 2119 o Changed to using the RFC 8174 boilerplate instead of the RFC 2119
boilerplate. boilerplate.
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Email: ludwig@ri.se Email: ludwig@ri.se
Goeran Selander Goeran Selander
Ericsson AB Ericsson AB
Faeroegatan 6 Faeroegatan 6
Kista 164 80 Kista 164 80
Sweden Sweden
Email: goran.selander@ericsson.com Email: goran.selander@ericsson.com
Erik Wahlstroem
Sweden
Email: erik@wahlstromstekniska.se
Samuel Erdtman Samuel Erdtman
Spotify AB Spotify
Birger Jarlsgatan 61, 4tr
Stockholm 113 56
Sweden
Phone: +46702691499
Email: erdtman@spotify.com Email: erdtman@spotify.com
Hannes Tschofenig Hannes Tschofenig
ARM Ltd. ARM Ltd.
Hall in Tirol 6060 Hall in Tirol 6060
Austria Austria
Email: Hannes.Tschofenig@arm.com Email: Hannes.Tschofenig@arm.com
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