Allow verifying SD-JWT VC against type metadata

[TimoGlastra]

It would be nice to have a feature that checks the presented SD-JWT VC against the (merged) type metadata.

Some checks that it could perform:

• If all fields are declared in the Type Metadata
  • I'm not sure this is always needed, since extra claims are not a problem maybe? But according to this issue, that's what the EUDI reference verifier is doing: Unable to verify an sd-jwt that contains nested claims and jti eu-digital-identity-wallet/eudi-srv-verifier-endpoint#400
• If all fields marked as sd: never are indeed not-selectively-discloseable
• If all fields marked as sd: always are indeed selectively-discloseable
• If all fields marked as mandatory are included

I think it should not be a method that throws an error, but just returns the results. So for example it will return:

{
  // claims not listed in type metadata
  "extraClaims": ["jit"],

  // claims listed as mandatory in the type metadata, but not present in the SD-JWT
  // might need to split into missing mandatory claims that are vs aren't selectively discloseable (since a verifier can
  // only determine based on the presented claims).  
  "missingMandatoryClaims": ["address"],

  // claims that are not selectively discloseable, but should be according to type metadata
  "invalidNonSelectivelyDisclosableClaims": ["age_over_18"],

  // claims that are selectively discloseable, but should not be according to type metadat
  "invalidSelectivelyDisclosableClaims": ["age_over_18"]
}

Naming of keys can be improved ;)

PID Type Metadata exmaple

{
  "vct": "urn:eudi:pid:1",
  "name": "Type Metadata for Person Identification Data",
  "display": [
    {
      "lang": "en",
      "name": "PID",
      "description": "Person Identification Data"
    }
  ],
  "claims": [
    {
      "path": [
        "iss"
      ],
      "sd": "never"
    },
    {
      "path": [
        "nbf"
      ],
      "sd": "never"
    },
    {
      "path": [
        "exp"
      ],
      "sd": "never"
    },
    {
      "path": [
        "cnf"
      ],
      "sd": "never"
    },
    {
      "path": [
        "vct"
      ],
      "sd": "never"
    },
    {
      "path": [
        "status"
      ],
      "sd": "never"
    },
    {
      "path": [
        "sub"
      ],
      "sd": "never"
    },
    {
      "path": [
        "iat"
      ],
      "sd": "never"
    },
    {
      "path": [
        "family_name"
      ],
      "display": [
        {
          "lang": "en",
          "label": "Family Name(s)"
        }
      ],
      "sd": "always"
    },
    {
      "path": [
        "given_name"
      ],
      "display": [
        {
          "lang": "en",
          "label": "Given Name(s)"
        }
      ],
      "sd": "always"
    },
    {
      "path": [
        "birthdate"
      ],
      "display": [
        {
          "lang": "en",
          "label": "Birth Date"
        }
      ],
      "sd": "always"
    },
    {
      "path": [
        "place_of_birth"
      ],
      "display": [
        {
          "lang": "en",
          "label": "Birth Place"
        }
      ],
      "sd": "always"
    },
    {
      "path": [
        "place_of_birth",
        "locality"
      ],
      "display": [
        {
          "lang": "en",
          "label": "Locality"
        }
      ],
      "sd": "always"
    },
    {
      "path": [
        "place_of_birth",
        "region"
      ],
      "display": [
        {
          "lang": "en",
          "label": "Region"
        }
      ],
      "sd": "always"
    },
    {
      "path": [
        "place_of_birth",
        "country"
      ],
      "display": [
        {
          "lang": "en",
          "label": "Country"
        }
      ],
      "sd": "always"
    },
    {
      "path": [
        "nationalities"
      ],
      "display": [
        {
          "lang": "en",
          "label": "Nationality"
        }
      ],
      "sd": "always"
    },
    {
      "path": [
        "nationalities",
        null],
      "sd": "always"
    },
    {
      "path": [
        "address"
      ],
      "display": [
        {
          "lang": "en",
          "label": "Address"
        }
      ],
      "sd": "always"
    },
    {
      "path": [
        "address",
        "house_number"
      ],
      "display": [
        {
          "lang": "en",
          "label": "House Number"
        }
      ],
      "sd": "always"
    },
    {
      "path": [
        "address",
        "street_address"
      ],
      "display": [
        {
          "lang": "en",
          "label": "Street"
        }
      ],
      "sd": "always"
    },
    {
      "path": [
        "address",
        "locality"
      ],
      "display": [
        {
          "lang": "en",
          "label": "Locality"
        }
      ],
      "sd": "always"
    },
    {
      "path": [
        "address",
        "region"
      ],
      "display": [
        {
          "lang": "en",
          "label": "Region"
        }
      ],
      "sd": "always"
    },
    {
      "path": [
        "address",
        "postal_code"
      ],
      "display": [
        {
          "lang": "en",
          "label": "Postal Code"
        }
      ],
      "sd": "always"
    },
    {
      "path": [
        "address",
        "country"
      ],
      "display": [
        {
          "lang": "en",
          "label": "Country"
        }
      ],
      "sd": "always"
    },
    {
      "path": [
        "address",
        "formatted"
      ],
      "display": [
        {
          "lang": "en",
          "label": "Full Address"
        }
      ],
      "sd": "always"
    },
    {
      "path": [
        "personal_administrative_number"
      ],
      "display": [
        {
          "lang": "en",
          "label": "Personal Administrative Number"
        }
      ],
      "sd": "always"
    },
    {
      "path": [
        "picture"
      ],
      "display": [
        {
          "lang": "en",
          "label": "Portrait Image"
        }
      ],
      "sd": "always"
    },
    {
      "path": [
        "birth_family_name"
      ],
      "display": [
        {
          "lang": "en",
          "label": "Birth Family Name(s)"
        }
      ],
      "sd": "always"
    },
    {
      "path": [
        "birth_given_name"
      ],
      "display": [
        {
          "lang": "en",
          "label": "Birth Given Name(s)"
        }
      ],
      "sd": "always"
    },
    {
      "path": [
        "sex"
      ],
      "display": [
        {
          "lang": "en",
          "label": "Sex"
        }
      ],
      "sd": "always"
    },
    {
      "path": [
        "email"
      ],
      "display": [
        {
          "lang": "en",
          "label": "Email Address"
        }
      ],
      "sd": "always"
    },
    {
      "path": [
        "phone_number"
      ],
      "display": [
        {
          "lang": "en",
          "label": "Mobile Phone Number"
        }
      ],
      "sd": "always"
    },
    {
      "path": [
        "date_of_expiry"
      ],
      "display": [
        {
          "lang": "en",
          "label": "Expiry Date"
        }
      ],
      "sd": "always"
    },
    {
      "path": [
        "issuing_authority"
      ],
      "display": [
        {
          "lang": "en",
          "label": "Issuing Authority"
        }
      ],
      "sd": "always"
    },
    {
      "path": [
        "issuing_country"
      ],
      "display": [
        {
          "lang": "en",
          "label": "Issuing Country"
        }
      ],
      "sd": "always"
    },
    {
      "path": [
        "document_number"
      ],
      "display": [
        {
          "lang": "en",
          "label": "Document Number"
        }
      ],
      "sd": "always"
    },
    {
      "path": [
        "issuing_jurisdiction"
      ],
      "display": [
        {
          "lang": "en",
          "label": "Issuing Jurisdiction"
        }
      ],
      "sd": "always"
    },
    {
      "path": [
        "date_of_issuance"
      ],
      "display": [
        {
          "lang": "en",
          "label": "Issuance Date"
        }
      ],
      "sd": "always"
    },
    {
      "path": [
        "trust_anchor"
      ],
      "display": [
        {
          "lang": "en",
          "label": "Trust Anchor"
        }
      ],
      "sd": "always"
    }
  ]
}