Verification steps for the KB-JWT are missing in section 7.1

[Denisthemalice]

In Section 7.1 (Verification of the SD-JWT), the text states:

Upon receiving an SD-JWT, either directly or as a component of an SD- JWT+KB, a Holder or a Verifier needs to ensure that:

• the Issuer-signed JWT is valid, i.e., it is signed by the Issuer and the signature is valid, and

Change into:

Upon receiving an SD-JWT, a Holder or a Verifier needs to ensure that:

• the Issuer belongs to a set of Trusted Issuers using a certification path up to a trusted root,

• the Issuer-signed JWT is valid, i.e., it is signed by a Trusted Issuer and the signature is valid, and

Section 4.1 in step 6 mentions:

6. The payload MAY contain further claims such as iss, iat, etc. as defined or required by the application using SD-JWTs.

Corresponding verification steps should be added in section 7.1. After the following item:

   3.  Validate the Issuer and that the signing key belongs to this
       Issuer.

Add the following item:

   4.  If required by the application using SD-JWTs, check that 
       further claims such as iss, iat, nbf, exp, etc. are present 
       and contain appropriate values.

Some other steps are missing. Add:

   5.  If required by the application using SD-JWTs and if the 
       SD-JWT contains claims such as nbf or exp, verify that the 
       current time lies between these two values.
   6.  If required by the application using SD-JWTs and if the 
       previous verification succeeds, verify that the SD-JWT is 
       not currently suspended, nor revoked.

Note : The means to verify that the SD-JWT is not currently suspended, nor revoked, are not defined in this document.