Internet DRAFT - draft-terbu-oauth-sd-jwt-vc
draft-terbu-oauth-sd-jwt-vc
TODO Working Group O. Terbu
Internet-Draft Spruce Systems, Inc.
Intended status: Standards Track D. Fett
Expires: 11 January 2024 Authlete Inc.
10 July 2023
SD-JWT-based Verifiable Credentials (SD-JWT VC)
draft-terbu-oauth-sd-jwt-vc-00
Abstract
This specification describes data formats as well as validation and
processing rules to express Verifiable Credentials with JSON payloads
based on the Selective Disclosure for JWTs (SD-JWT)
[I-D.ietf-oauth-selective-disclosure-jwt] format. It can be used
when there are no selective disclosable claims, too.
Status of This Memo
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This Internet-Draft will expire on 11 January 2024.
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Copyright (c) 2023 IETF Trust and the persons identified as the
document authors. All rights reserved.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1. Issuer-Holder-Verifier Model . . . . . . . . . . . . . . 2
1.2. Rationale . . . . . . . . . . . . . . . . . . . . . . . . 4
1.3. Requirements Notation and Conventions . . . . . . . . . . 4
1.4. Terms and Definitions . . . . . . . . . . . . . . . . . . 4
2. Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
3. Use Cases . . . . . . . . . . . . . . . . . . . . . . . . . . 5
4. Verifiable Credentials based on SD-JWT . . . . . . . . . . . 5
4.1. Media Type . . . . . . . . . . . . . . . . . . . . . . . 5
4.2. Data Format . . . . . . . . . . . . . . . . . . . . . . . 5
4.2.1. Header Parameters . . . . . . . . . . . . . . . . . . 6
4.2.2. Claims . . . . . . . . . . . . . . . . . . . . . . . 6
4.3. Example . . . . . . . . . . . . . . . . . . . . . . . . . 8
4.4. Verification and Processing . . . . . . . . . . . . . . . 12
5. JWT Issuer Metadata . . . . . . . . . . . . . . . . . . . . . 13
5.1. JWT Issuer Metadata Request . . . . . . . . . . . . . . . 13
5.2. JWT Issuer Metadata Response . . . . . . . . . . . . . . 13
5.3. JWT Issuer Metadata Validation . . . . . . . . . . . . . 15
6. Presenting Verifiable Credentials . . . . . . . . . . . . . . 15
6.1. Data Format . . . . . . . . . . . . . . . . . . . . . . . 15
6.1.1. Key Binding JWT . . . . . . . . . . . . . . . . . . . 16
6.2. Examples . . . . . . . . . . . . . . . . . . . . . . . . 16
6.3. Verification and Processing . . . . . . . . . . . . . . . 18
7. Security Considerations . . . . . . . . . . . . . . . . . . . 18
8. Privacy Considerations . . . . . . . . . . . . . . . . . . . 18
9. Relationships to Other Documents . . . . . . . . . . . . . . 18
10. Normative References . . . . . . . . . . . . . . . . . . . . 18
11. Informative References . . . . . . . . . . . . . . . . . . . 19
Appendix A. IANA Considerations . . . . . . . . . . . . . . . . 19
A.1. JSON Web Token Claims Registration . . . . . . . . . . . 19
A.2. Media Types Registry . . . . . . . . . . . . . . . . . . 19
A.2.1. application/vc+sd-jwt . . . . . . . . . . . . . . . . 19
Appendix B. Acknowledgements . . . . . . . . . . . . . . . . . . 20
Appendix C. Document History . . . . . . . . . . . . . . . . . . 20
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 20
1. Introduction
1.1. Issuer-Holder-Verifier Model
In the so-called Issuer-Holder-Verifier Model, Issuers issue
Verifiable Credentials to a Holder, who can then present the
Verifiable Credentials to Verifiers. Verifiable Credentials are
cryptographically signed statements about a Subject, typically the
Holder.
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+------------+
| |
| Issuer |
| |
+------------+
|
Issues Verifiable Credential
|
v
+------------+
| |
| Holder |
| |
+------------+
|
Presents Verifiable Credential
|
v
+-------------+
| |+ +------------+
| Verifiers ||+ | Status |
| |||----- optionally ------->| Provider |
+-------------+|| retrieve status of | |
+-------------+| Verifiable Credential +------------+
+-------------+
Figure 1: Issuer-Holder-Verifier Model with optional Status Provider
Verifiers can check the authenticity of the data in the Verifiable
Credentials and optionally enforce Key Binding, i.e., ask the Holder
to prove that they are the intended holder of the Verifiable
Credential, for example, by proving possession of a cryptographic key
referenced in the credential. This process is further described in
[I-D.ietf-oauth-selective-disclosure-jwt].
To support revocation of Verifiable Credentials, revocation
information can optionally be retrieved from a Status Provider. The
role of a Status Provider can be fulfilled by either a fourth party
or by the Issuer.
This specification defines Verifiable Credentials based on the SD-JWT
format with a JWT Claim Set. It can be used when there are no
selective disclosable claims, too.
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1.2. Rationale
JSON Web Tokens (JWTs) [RFC7519] can in principle be used to express
Verifiable Credentials in a way that is easy to understand and
process as it builds upon established web primitives.
Selective Disclosure JWT (SD-JWT)
[I-D.ietf-oauth-selective-disclosure-jwt] is a specification that
introduces conventions to support selective disclosure for JWTs: For
an SD-JWT document, a Holder can decide which claims to release
(within bounds defined by the Issuer).
SD-JWT is a superset of JWT as it can also be used when there are no
selectively disclosable claims and also supports JWS JSON
serialization, which is useful for long term archiving and multi
signatures. However, SD-JWT itself does not define the claims that
must be used within the payload or their semantics.
This specification therefore uses SD-JWT and the well-established JWT
content rules and extensibility model as basis for representing
Verifiable Credentials with JSON payload. Those Verifiable
Credentials are called SD-JWT VCs.
SD-JWTs VC can contain claims that are registered in "JSON Web Token
Claims" registry as defined in [RFC7519], as well as public and
private claims.
Note: This specification does not utilize the W3C's Verifiable
Credentials Data Model v1.0, v1.1, or v2.0.
1.3. Requirements Notation and Conventions
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in RFC
2119 [RFC2119].
1.4. Terms and Definitions
This specification uses the terms "Holder", "Issuer", "Verifier",
defined by [I-D.ietf-oauth-selective-disclosure-jwt].
Verifiable Credential (VC): An Issuer-signed assertion with claims
about a Subject.
SD-JWT-based Verifiable Credential (SD-JWT VC): A Verifiable
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Credential encoded using the Issuance format defined in
[I-D.ietf-oauth-selective-disclosure-jwt]. It may or may not
contain selectively disclosable claims.
Unsecured payload of an SD-JWT VC: A JSON object containing all
selectively disclosable and non-selectively disclosable claims of
the SD-JWT VC. The unsecured payload acts as the input JSON
object to issue an SD-JWT VC complying to this specification.
Status Provider: An entity that provides status information (e.g.
revocation) about a Verifiable Credential.
2. Scope
* This specification defines
- Data model and media types for Verifiable Credentials based on
SD-JWTs.
- Validation and processing rules for Verifiers and Holders.
3. Use Cases
TBD: explain use cases of the Issuer-Holder-Verifier Model.
TBD: conventional crypt, hardware security, hsm, mobile secure area,
compliance with FIPS
4. Verifiable Credentials based on SD-JWT
This section defines encoding, validation and processing rules for
SD-JWT VCs.
4.1. Media Type
SD-JWT VCs compliant with this specification MUST use the media type
application/vc+sd-jwt as defined in Appendix A.2.1.
4.2. Data Format
SD-JWT VCs MUST be encoded using the SD-JWT Combined Format for
Issuance as defined in Section 5.3. of
[I-D.ietf-oauth-selective-disclosure-jwt].
When there are selectively disclosable claims, SD-JWT VCs MUST
contain all Disclosures corresponding to their SD-JWT component
except for Decoy Digests as per Section 5.1.1.3. of
[I-D.ietf-oauth-selective-disclosure-jwt].
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4.2.1. Header Parameters
This section defines JWT header parameters for the SD-JWT component
of the SD-JWT VC.
The typ header parameter of the SD-JWT MUST be present. The typ
value MUST use vc+sd-jwt. This indicates that the payload of the SD-
JWT contains plain JSON and follows the rules as defined in this
specification. It further indicates that the SD-JWT is a SD-JWT
component of a SD-JWT VC.
The following is a non-normative example of a decoded SD-JWT header:
{
"alg": "ES256",
"typ": "vc+sd-jwt"
}
4.2.2. Claims
This section defines the claims that can be included in the payload
of SD-JWT VCs.
4.2.2.1. type claim
This specification defines the JWT claim type. The type claim is
used to express the type of the JSON object that is secured by the
JWT. The type value MUST be a case-sensitive StringOrURI value.
The following is a non-normative example of how type is used to
express a type:
{
"type": "SomeType"
}
4.2.2.2. Registered JWT Claims
SD-JWT VCs MAY use any claim registered in the "JSON Web Token
Claims" registry as defined in [RFC7519].
If present, the following registered JWT claims MUST be included in
the SD-JWT and MUST NOT be included in the Disclosures, i.e. cannot
be selectively disclosed:
* iss
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- REQUIRED. The Issuer of the Verifiable Credential. The value
of iss MUST be a URI. See [RFC7519] for more information.
* iat
- REQUIRED. The time of issuance of the Verifiable Credential.
See [RFC7519] for more information.
* nbf
- OPTIONAL. The time before which the Verifiable Credential MUST
NOT be accepted before validating. See [RFC7519] for more
information.
* exp
- OPTIONAL. The expiry time of the Verifiable Credential after
which the Verifiable Credential is no longer valid. See
[RFC7519] for more information.
* cnf
- REQUIRED when Cryptographic Key Binding is to be supported.
Contains the confirmation method as defined in [RFC7800]. It
SHOULD contain a JWK as defined in Section 3.2 of [RFC7800].
For Cryptographic Key Binding, the Key Binding JWT in the
Combined Format for Presentation MUST be signed by the key
identified in this claim.
* type
- REQUIRED. The type of the Verifiable Credential, e.g.,
IdentityCredential, as defined in Section 4.2.2.1.
* status
- OPTIONAL. The information on how to read the status of the
Verifiable Credential. See [TBD] for more information.
The following registered JWT claims MAY be contained in the SD-JWT or
in the Disclosures and MAY be selectively disclosed:
* sub
- OPTIONAL. The identifier of the Subject of the Verifiable
Credential. The Issuer MAY use it to provide the Subject
identifier known by the Issuer. There is no requirement for a
binding to exist between sub and cnf claims.
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4.2.2.3. Public JWT claims
Additional public claims MAY be used in SD-JWT VCs depending on the
application.
4.2.2.4. SD-JWT VC without Selectively Disclosable Claims
An SD-JWT VC MAY have no selectively disclosable claims. In that
case, the SD-JWT VC MUST NOT contain the _sd claim in the JWT body.
It also MUST NOT have any Disclosures.
4.3. Example
The following is a non-normative example of an unsecured payload of
an SD-JWT VC.
{
"type": "IdentityCredential",
"given_name": "John",
"family_name": "Doe",
"email": "johndoe@example.com",
"phone_number": "+1-202-555-0101",
"address": {
"street_address": "123 Main St",
"locality": "Anytown",
"region": "Anystate",
"country": "US"
},
"birthdate": "1940-01-01",
"is_over_18": true,
"is_over_21": true,
"is_over_65": true
}
The following is a non-normative example of how the unsecured payload
of the SD-JWT VC above can be used in a SD-JWT where the resulting
SD-JWT VC contains only claims about the Subject that are selectively
disclosable:
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{
"_sd": [
"09vKrJMOlyTWM0sjpu_pdOBVBQ2M1y3KhpH515nXkpY",
"2rsjGbaC0ky8mT0pJrPioWTq0_daw1sX76poUlgCwbI",
"EkO8dhW0dHEJbvUHlE_VCeuC9uRELOieLZhh7XbUTtA",
"IlDzIKeiZdDwpqpK6ZfbyphFvz5FgnWa-sN6wqQXCiw",
"JzYjH4svliH0R3PyEMfeZu6Jt69u5qehZo7F7EPYlSE",
"PorFbpKuVu6xymJagvkFsFXAbRoc2JGlAUA2BA4o7cI",
"TGf4oLbgwd5JQaHyKVQZU9UdGE0w5rtDsrZzfUaomLo",
"jdrTE8YcbY4EifugihiAe_BPekxJQZICeiUQwY9QqxI",
"jsu9yVulwQQlhFlM_3JlzMaSFzglhQG0DpfayQwLUK4"
],
"iss": "https://example.com/issuer",
"iat": 1683000000,
"exp": 1883000000,
"type": "IdentityCredential",
"_sd_alg": "sha-256",
"cnf": {
"jwk": {
"kty": "EC",
"crv": "P-256",
"x": "TCAER19Zvu3OHF4j4W4vfSVoHIP1ILilDls7vCeGemc",
"y": "ZxjiWWbZMQGHVWKVQ4hbSIirsVfuecCE6t4jT9F2HZQ"
}
}
}
Note that a cnf claim has been added to the SD-JWT payload to express
the confirmation method of the Key Binding.
The following are the Disclosures belonging to the SD-JWT payload
above:
*Claim given_name*:
* SHA-256 Hash: jsu9yVulwQQlhFlM_3JlzMaSFzglhQG0DpfayQwLUK4
* Disclosure:
WyIyR0xDNDJzS1F2ZUNmR2ZyeU5STjl3IiwgImdpdmVuX25hbWUiLCAiSm9o
biJd
* Contents: ["2GLC42sKQveCfGfryNRN9w", "given_name", "John"]
*Claim family_name*:
* SHA-256 Hash: TGf4oLbgwd5JQaHyKVQZU9UdGE0w5rtDsrZzfUaomLo
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* Disclosure:
WyJlbHVWNU9nM2dTTklJOEVZbnN4QV9BIiwgImZhbWlseV9uYW1lIiwgIkRv
ZSJd
* Contents: ["eluV5Og3gSNII8EYnsxA_A", "family_name", "Doe"]
*Claim email*:
* SHA-256 Hash: JzYjH4svliH0R3PyEMfeZu6Jt69u5qehZo7F7EPYlSE
* Disclosure:
WyI2SWo3dE0tYTVpVlBHYm9TNXRtdlZBIiwgImVtYWlsIiwgImpvaG5kb2VA
ZXhhbXBsZS5jb20iXQ
* Contents: ["6Ij7tM-a5iVPGboS5tmvVA", "email",
"johndoe@example.com"]
*Claim phone_number*:
* SHA-256 Hash: PorFbpKuVu6xymJagvkFsFXAbRoc2JGlAUA2BA4o7cI
* Disclosure:
WyJlSThaV205UW5LUHBOUGVOZW5IZGhRIiwgInBob25lX251bWJlciIsICIr
MS0yMDItNTU1LTAxMDEiXQ
* Contents: ["eI8ZWm9QnKPpNPeNenHdhQ", "phone_number",
"+1-202-555-0101"]
*Claim address*:
* SHA-256 Hash: IlDzIKeiZdDwpqpK6ZfbyphFvz5FgnWa-sN6wqQXCiw
* Disclosure:
WyJRZ19PNjR6cUF4ZTQxMmExMDhpcm9BIiwgImFkZHJlc3MiLCB7InN0cmVl
dF9hZGRyZXNzIjogIjEyMyBNYWluIFN0IiwgImxvY2FsaXR5IjogIkFueXRv
d24iLCAicmVnaW9uIjogIkFueXN0YXRlIiwgImNvdW50cnkiOiAiVVMifV0
* Contents: ["Qg_O64zqAxe412a108iroA", "address", {"street_address":
"123 Main St", "locality": "Anytown", "region": "Anystate",
"country": "US"}]
*Claim birthdate*:
* SHA-256 Hash: jdrTE8YcbY4EifugihiAe_BPekxJQZICeiUQwY9QqxI
* Disclosure:
WyJBSngtMDk1VlBycFR0TjRRTU9xUk9BIiwgImJpcnRoZGF0ZSIsICIxOTQw
LTAxLTAxIl0
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* Contents: ["AJx-095VPrpTtN4QMOqROA", "birthdate", "1940-01-01"]
*Claim is_over_18*:
* SHA-256 Hash: 09vKrJMOlyTWM0sjpu_pdOBVBQ2M1y3KhpH515nXkpY
* Disclosure:
WyJQYzMzSk0yTGNoY1VfbEhnZ3ZfdWZRIiwgImlzX292ZXJfMTgiLCB0cnVl
XQ
* Contents: ["Pc33JM2LchcU_lHggv_ufQ", "is_over_18", true]
*Claim is_over_21*:
* SHA-256 Hash: 2rsjGbaC0ky8mT0pJrPioWTq0_daw1sX76poUlgCwbI
* Disclosure:
WyJHMDJOU3JRZmpGWFE3SW8wOXN5YWpBIiwgImlzX292ZXJfMjEiLCB0cnVl
XQ
* Contents: ["G02NSrQfjFXQ7Io09syajA", "is_over_21", true]
*Claim is_over_65*:
* SHA-256 Hash: EkO8dhW0dHEJbvUHlE_VCeuC9uRELOieLZhh7XbUTtA
* Disclosure:
WyJsa2x4RjVqTVlsR1RQVW92TU5JdkNBIiwgImlzX292ZXJfNjUiLCB0cnVl
XQ
* Contents: ["lklxF5jMYlGTPUovMNIvCA", "is_over_65", true]
The SD-JWT and the Disclosures would then be serialized by the Issuer
into the following format for issuance to the Holder:
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eyJhbGciOiAiRVMyNTYifQ.eyJfc2QiOiBbIjA5dktySk1PbHlUV00wc2pwdV9wZE9CV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.nIneu9ghAY_pjnfAczLZe80xN2Z-jjxs42MOx8UVZtCT4ACFV
W8RMdBANSwjfRBD1Xag6vnayC6HUnBvkVWlMQ~WyIyR0xDNDJzS1F2ZUNmR2ZyeU5STj
l3IiwgImdpdmVuX25hbWUiLCAiSm9obiJd~WyJlbHVWNU9nM2dTTklJOEVZbnN4QV9BI
iwgImZhbWlseV9uYW1lIiwgIkRvZSJd~WyI2SWo3dE0tYTVpVlBHYm9TNXRtdlZBIiwg
ImVtYWlsIiwgImpvaG5kb2VAZXhhbXBsZS5jb20iXQ~WyJlSThaV205UW5LUHBOUGVOZ
W5IZGhRIiwgInBob25lX251bWJlciIsICIrMS0yMDItNTU1LTAxMDEiXQ~WyJRZ19PNj
R6cUF4ZTQxMmExMDhpcm9BIiwgImFkZHJlc3MiLCB7InN0cmVldF9hZGRyZXNzIjogIj
EyMyBNYWluIFN0IiwgImxvY2FsaXR5IjogIkFueXRvd24iLCAicmVnaW9uIjogIkFueX
N0YXRlIiwgImNvdW50cnkiOiAiVVMifV0~WyJBSngtMDk1VlBycFR0TjRRTU9xUk9BIi
wgImJpcnRoZGF0ZSIsICIxOTQwLTAxLTAxIl0~WyJQYzMzSk0yTGNoY1VfbEhnZ3ZfdW
ZRIiwgImlzX292ZXJfMTgiLCB0cnVlXQ~WyJHMDJOU3JRZmpGWFE3SW8wOXN5YWpBIiw
gImlzX292ZXJfMjEiLCB0cnVlXQ~WyJsa2x4RjVqTVlsR1RQVW92TU5JdkNBIiwgImlz
X292ZXJfNjUiLCB0cnVlXQ~
4.4. Verification and Processing
The recipient of the SD-JWT VC MUST process and verify an SD-JWT VC
as follows:
1. REQUIRED. Process and verify the SD-JWT as defined in Section 6.
of [I-D.ietf-oauth-selective-disclosure-jwt]. For the
verification, the iss claim in the SD-JWT MAY be used to retrieve
the public key from the JWT Issuer Metadata configuration (as
defined in Section 5) of the SD-JWT VC issuer. A Verifier MAY
use alternative methods to obtain the public key to verify the
signature of the SD-JWT. If there are no selectively disclosable
claims, there is no need to process the _sd claim nor any
Disclosures.
2. OPTIONAL. If status is present in the verified payload of the
SD-JWT, the status SHOULD be checked. It depends on the Verifier
policy to reject or accept a presentation of a SD-JWT VC based on
the status of the Verifiable Credential.
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Any claims used that are not understood MUST be ignored.
Additional validation rules MAY apply, but their use is out of the
scope of this specification.
5. JWT Issuer Metadata
This specification defines the JWT Issuer Metadata to retrieve the
JWT Issuer Metadata configuration of the JWT Issuer of the JWT. The
JWT Issuer is identified by the iss claim in the JWT. Use of the JWT
Issuer Metadata is OPTIONAL.
JWT Issuers publishing JWT Issuer Metadata MUST make a JWT Issuer
Metadata configuration available at the path formed by concatenating
the string /.well-known/jwt-issuer to the iss claim value in the JWT.
The iss MUST be a case-sensitive URL using the HTTPS scheme that
contains scheme, host and, optionally, port number and path
components, but no query or fragment components.
5.1. JWT Issuer Metadata Request
A JWT Issuer Metadata configuration MUST be queried using an HTTP GET
request at the path defined in Section 5.
The following is a non-normative example of a HTTP request for the
JWT Issuer Metadata configuration when iss is set to
https://example.com:
GET /.well-known/jwt-issuer HTTP/1.1
Host: example.com
If the iss value contains a path component, any terminating / MUST be
removed before inserting /.well-known/ and the well-known URI suffix
between the host component and the path component.
The following is a non-normative example of a HTTP request for the
JWT Issuer Metadata configuration when iss is set to
https://example.com/user/1234:
GET /.well-known/jwt-issuer/user/1234 HTTP/1.1
Host: example.com
5.2. JWT Issuer Metadata Response
A successful response MUST use the 200 OK HTTP and return the JWT
Issuer Metadata configuration using the application/json content
type.
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An error response uses the applicable HTTP status code value.
This specification defines the following JWT Issuer Metadata
configuration parameters:
* issuer REQUIRED. The JWT Issuer identifier, which MUST be
identical to the iss value in the JWT.
* jwks_uri
- OPTIONAL. URL string referencing the JWT Issuer's JSON Web Key
(JWK) Set [RFC7517] document which contains the JWT Issuer's
public keys. The value of this field MUST point to a valid JWK
Set document. Use of this parameter is RECOMMENDED, as it
allows for easy key rotation.
* jwks
- OPTIONAL. JWT Issuer's JSON Web Key Set [RFC7517] document
value, which contains the JWT Issuer's public keys. The value
of this field MUST be a JSON object containing a valid JWK Set.
This parameter is intended to be used by JWT Issuer that cannot
use the jwks_uri parameter.
JWT Issuer Metadata MUST include either jwks_uri or jwks in their JWT
Issuer Metadata, but not both.
It is RECOMMENDED that the JWT contains a kid JWT header parameter
that can be used to lookup the public key in the JWK Set included by
value or referenced in the JWT Issuer Metadata.
The following is a non-normative example of a JWT Issuer Metadata
configuration including jwks:
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{
"issuer":"https://example.com",
"jwks":{
"keys":[
{
"kid":"doc-signer-05-25-2022",
"e":"AQAB",
"n":"nj3YJwsLUFl9BmpAbkOswCNVx17Eh9wMO-_AReZwBqfaWFcfG
HrZXsIV2VMCNVNU8Tpb4obUaSXcRcQ-VMsfQPJm9IzgtRdAY8NN8Xb7PEcYyk
lBjvTtuPbpzIaqyiUepzUXNDFuAOOkrIol3WmflPUUgMKULBN0EUd1fpOD70p
RM0rlp_gg_WNUKoW1V-3keYUJoXH9NztEDm_D2MQXj9eGOJJ8yPgGL8PAZMLe
2R7jb9TxOCPDED7tY_TU4nFPlxptw59A42mldEmViXsKQt60s1SLboazxFKve
qXC_jpLUt22OC6GUG63p-REw-ZOr3r845z50wMuzifQrMI9bQ",
"kty":"RSA"
}
]
}
}
The following is a non-normative example of a JWT Issuer Metadata
configuration including jwks_uri:
{
"issuer":"https://example.com",
"jwks_uri":"https://jwt-issuer.example.org/my_public_keys.jwks"
}
Additional JWT Issuer Metadata configuration parameters MAY also be
used.
5.3. JWT Issuer Metadata Validation
The issuer value returned MUST be identical to the iss value of the
JWT. If these values are not identical, the data contained in the
response MUST NOT be used.
6. Presenting Verifiable Credentials
This section defines encoding, validation and processing rules for
presentations of SD-JWT VCs.
6.1. Data Format
A presentation of an SD-JWT VC MUST be encoded using the SD-JWT
Combined Format for Presentation as defined in Section 5.4. of
[I-D.ietf-oauth-selective-disclosure-jwt].
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A presentation of an SD-JWT VC MAY contain a Key Binding JWT as
described in Section 5.4.1. of
[I-D.ietf-oauth-selective-disclosure-jwt].
When there are no selectively disclosable claims, a presentation of
SD-JWT VC does not contain any Disclosures.
6.1.1. Key Binding JWT
If the presentation of the SD-JWT VC includes a Key Binding JWT, the
following claims are used within the Key Binding JWT:
* nonce
- REQUIRED. String value used to associate a transaction between
a Verifier an a Holder, and to mitigate replay attacks. The
value is passed through unmodified from the Verifier to the Key
Binding JWT. Sufficient entropy MUST be present in the nonce
values used to prevent attackers from guessing values.
* aud
- REQUIRED. The intended recipient of the Key Binding JWT which
is typically the Verifier. See [RFC7519] for more information.
* iat
- REQUIRED. The time of issuance of the Key Binding JWT. See
[RFC7519] for more information.
* exp
- OPTIONAL. The expiration time of the signature when the Key
Binding is no longer considered valid. See [RFC7519] for more
information.
The Key Binding JWT MAY include addtional claims which when not
understood MUST be ignored.
6.2. Examples
The following is a non-normative example of a presentation of the SD-
JWT shown above including a Key Binding JWT:
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eyJhbGciOiAiRVMyNTYifQ.eyJfc2QiOiBbIjA5dktySk1PbHlUV00wc2pwdV9wZE9CV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.nIneu9ghAY_pjnfAczLZe80xN2Z-jjxs42MOx8UVZtCT4ACFV
W8RMdBANSwjfRBD1Xag6vnayC6HUnBvkVWlMQ~WyJRZ19PNjR6cUF4ZTQxMmExMDhpcm
9BIiwgImFkZHJlc3MiLCB7InN0cmVldF9hZGRyZXNzIjogIjEyMyBNYWluIFN0IiwgIm
xvY2FsaXR5IjogIkFueXRvd24iLCAicmVnaW9uIjogIkFueXN0YXRlIiwgImNvdW50cn
kiOiAiVVMifV0~eyJhbGciOiAiRVMyNTYiLCAidHlwIjogImtiK2p3dCJ9.eyJub25jZ
SI6ICIxMjM0NTY3ODkwIiwgImF1ZCI6ICJodHRwczovL2V4YW1wbGUuY29tL3Zlcmlma
WVyIiwgImlhdCI6IDE2ODkwMTIzMzR9.3rROqnKkUNgiYfSwtmTXnXVMtSfb_RA2pVVv
EclTihvi7MIZ-W_x3sVPVliJJIDdH4frgvxjxMWa__vCoTEbqQ
In this presentation, the Holder provides only the Disclosure for the
claim address. Other claims are not disclosed to the Verifier.
The following example shows a presentation of a (different) SD-JWT
without a Key Binding JWT:
eyJhbGciOiAiRVMyNTYifQ.eyJfc2QiOiBbIjA5dktySk1PbHlUV00wc2pwdV9wZE9CV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.gew2qB8_rJxmckdiQ8S_VE-GouPs2XE5q3NdfAeh6QdZ20
qQrXZNIEvUwAX4rSPvE9UfD_D2zZgYgS3EdQPkQg~WyJRZ19PNjR6cUF4ZTQxMmExMDh
pcm9BIiwgImFkZHJlc3MiLCB7InN0cmVldF9hZGRyZXNzIjogIjEyMyBNYWluIFN0Iiw
gImxvY2FsaXR5IjogIkFueXRvd24iLCAicmVnaW9uIjogIkFueXN0YXRlIiwgImNvdW5
0cnkiOiAiVVMifV0~
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6.3. Verification and Processing
The Verifier MUST process and verify a presentation of SD-JWT VC as
follows:
1. REQUIRED. When processing and verifying the presentation of the
SD-JWT VC, the Verifier MUST follow the same verification and
processing rules as defined in Section 4.4.
2. OPTIONAL. If provided, the Verifier MUST verify the Key Binding
JWT according to Section 6.2. of
[I-D.ietf-oauth-selective-disclosure-jwt]. To verify the Key
Binding JWT, the cnf claim of the SD-JWT MUST be used.
7. Security Considerations
TBD: Verifier provided nonce.
8. Privacy Considerations
TBD: Holder provided nonce via jti.
9. Relationships to Other Documents
TBD
10. Normative References
[I-D.ietf-oauth-selective-disclosure-jwt]
Fett, D., Yasuda, K., and B. Campbell, "Selective
Disclosure for JWTs (SD-JWT)", Work in Progress, Internet-
Draft, draft-ietf-oauth-selective-disclosure-jwt-05, 30
June 2023, <https://datatracker.ietf.org/doc/html/draft-
ietf-oauth-selective-disclosure-jwt-05>.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/info/rfc2119>.
[RFC7519] Jones, M., Bradley, J., and N. Sakimura, "JSON Web Token
(JWT)", RFC 7519, DOI 10.17487/RFC7519, May 2015,
<https://www.rfc-editor.org/info/rfc7519>.
[RFC7800] Jones, M., Bradley, J., and H. Tschofenig, "Proof-of-
Possession Key Semantics for JSON Web Tokens (JWTs)",
RFC 7800, DOI 10.17487/RFC7800, April 2016,
<https://www.rfc-editor.org/info/rfc7800>.
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11. Informative References
[RFC7517] Jones, M., "JSON Web Key (JWK)", RFC 7517,
DOI 10.17487/RFC7517, May 2015,
<https://www.rfc-editor.org/info/rfc7517>.
Appendix A. IANA Considerations
A.1. JSON Web Token Claims Registration
* Claim Name: "type"
- Claim Description: Credential Type
- Change Controller: IESG
- Specification Document(s): Section 4.2.2.1 of this document
A.2. Media Types Registry
A.2.1. application/vc+sd-jwt
The Internet media type for a SD-JWT VC is application/vc+sd-jwt.
Type name: : application
Subtype name: : vc+sd-jwt
Required parameters: : n/a
Optional parameters: : n/a
Encoding considerations: : 8-bit code points; SD-JWT VC values are
encoded as a series of base64url-encoded values (some of which may be
the empty string) separated by period ('.') and tilde ('~')
characters.
Security considerations: : See Security Considerations in Section 7.
Interoperability considerations: : n/a
* Published specification: : RFC TODO
* Applications that use this media type: : Applications that issue,
present, verify verifiable credentials and presentations.
* Additional information:
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- Magic number(s): n/a
- File extension(s): n/a
- Macintosh file type code(s): n/a
- Person & email address to contact for further information: TBD
- Intended usage: COMMON
- Restrictions on usage: none
- Author: Oliver Terbu oliver.terbu@spruceid.com
(mailto:oliver.terbu@spruceid.com)
- Change controller: IETF
Appendix B. Acknowledgements
We would like to thank Alen Horvat, Andres Uribe, Brian Campbell,
Christian Bormann, Giuseppe De Marco, Michael Jones, Mike Prorock,
Orie Steele, Paul Bastian, Torsten Lodderstedt, Tobias Looker, and
Kristina Yasuda for their contributions (some of which substantial)
to this draft and to the initial set of implementations.
Appendix C. Document History
-00
* Initial Version
* Removed W3C VCDM transformation algorithm
* Various editorial changes based on feedback
* Adjusted terminology based on feedback
* Added non-selectively disclosable JWT VC
* Added a note that this is not W3C VCDM
Authors' Addresses
Oliver Terbu
Spruce Systems, Inc.
Email: oliver.terbu@spruceid.com
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Daniel Fett
Authlete Inc.
Email: mail@danielfett.de
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