Adapt description of ID Token

Author: danielfett

openid-4-verifiable-presentations-1_0.md

@@ -113,7 +113,7 @@ Biometrics-based Holder Binding:
 :  Ability of the Holder to prove legitimate possession of a Verifiable Credential by demonstrating a certain biometric trait, such as finger print or face. One example of a Verifiable Credential with biometric Holder Binding is a mobile driving license [@ISO.18013-5], which contains a portrait of the Holder.
 
 VP Token:
-: An artifact defined in this specification that contains a single Verifiable Presentation or an array of Verifiable Presentations as defined in (#response-parameters).
+: An artifact containing one or more Verifiable Presentations returned as a response to an Authorization Request. The structure of VP Tokens is defined in (#response-parameters).
 
 Wallet:
 :  An entity used by the Holder to receive, store, present, and manage Verifiable Credentials and key material. There is no single deployment model of a Wallet: Verifiable Credentials and keys can both be stored/managed locally, or by using a remote self-hosted service, or a remote third-party service. In the context of this specification, the Wallet acts as an OAuth 2.0 Authorization Server (see [@!RFC6749]) towards the Credential Verifier which acts as the OAuth 2.0 Client.
@@ -882,7 +882,9 @@ The behavior with respect to the VP Token is unspecified for any other individua
 When a VP Token is returned, the respective response MUST include the following parameters:
 
 `vp_token`:
-: REQUIRED. JSON String or JSON object that MUST contain a single Verifiable Presentation or an array of JSON Strings and JSON objects each of them containing a Verifiable Presentations. Each Verifiable Presentation MUST be represented as a JSON string (that is a base64url-encoded value) or a JSON object depending on a format as defined in Appendix A of [@!OpenID.VCI].  When a single Verifiable Presentation is returned, the array syntax MUST NOT be used.  If Appendix A of [@!OpenID.VCI] defines a rule for encoding the respective Credential format in the Credential Response, this rules MUST also be followed when encoding Credentials of this format in the `vp_token` response parameter. Otherwise, this specification does not require any additional encoding when a Credential format is already represented as a JSON object or a JSON string.
+: REQUIRED. The structure of this parameter depends on the Authorization Request:
+ * In case Presentation Exchange was used in the Authorization Request, it is a JSON String or JSON object that MUST contain a single Verifiable Presentation or an array of JSON Strings and JSON objects each of them containing a Verifiable Presentations. Each Verifiable Presentation MUST be represented as a JSON string (that is a base64url-encoded value) or a JSON object depending on a format as defined in Appendix A of [@!OpenID.VCI].  When a single Verifiable Presentation is returned, the array syntax MUST NOT be used.  If Appendix A of [@!OpenID.VCI] defines a rule for encoding the respective Credential format in the Credential Response, this rules MUST also be followed when encoding Credentials of this format in the `vp_token` response parameter. Otherwise, this specification does not require any additional encoding when a Credential format is already represented as a JSON object or a JSON string.
+ * In case the `vp_query` parameter was used, this is a JSON-encoded object; the keys are the `id` values used for the Credential Queries in the VP Query, and the values are the Verifiable Presentations that match the respective Credential Query. The Verifiable Presentations are represented as strings or objects depending on the format as defined in Appendix A of [@!OpenID.VCI]. The same rules as above apply for encoding the Verifiable Presentations.
 
 `presentation_submission`:
 : REQUIRED. The `presentation_submission` element as defined in [@!DIF.PresentationExchange]. It contains mappings between the requested Verifiable Credentials and where to find them within the returned VP Token. This is expressed via elements in the `descriptor_map` array, known as Input Descriptor Mapping Objects. These objects contain a field called `path`, which, for this specification, MUST have the value `$` (top level root path) when only one Verifiable Presentation is contained in the VP Token, and MUST have the value `$[n]` (indexed path from root) when there are multiple Verifiable Presentations, where `n` is the index to select. Additional parameters can be defined by Credential Formats, see (#alternative_credential_formats) for details.