Not being able to fetch type metadata should not fail verification?

[TimoGlastra]

As I understand the SD-JWT VC specification, the vct CAN be used to represent the type metadata URL, but i don't think it's invalid to use https:// uri for vct and not host type metadata?

Also the error message is the response of the VCT, which can be confusing. Instead of using response.text() as the error message, maybe it should be Error fetching type metadata. ${await response.text()}?

[cre8]

Hi @TimoGlastra ,

you can pass a parameter if the metadata should be loaded from the vct by setting a config value: https://github.com/openwallet-foundation/sd-jwt-js/blob/main/packages/sd-jwt-vc/src/sd-jwt-vc-config.ts#L18
the default value is false, so when there is a url it will not be fetched. But when there is another url and you set it to fetching, it will end in an error.

For the error for schema fetching we have this error message: https://github.com/openwallet-foundation/sd-jwt-js/blob/main/packages/sd-jwt-vc/src/sd-jwt-vc-instance.ts#L252

But in the fetch function it's generic in the fetch function because this function is used to fetch the status list and the schema that are throwing case specific error messages.

[TimoGlastra]

The config option assumes you know upfront whether the SD-JWT has type metadata. I'd like to fetch the type metadata if it exists, but if the endpoint returns 404 that seems fine to me.

[cre8]

The config option assumes you know upfront whether the SD-JWT has type metadata. I'd like to fetch the type metadata if it exists, but if the endpoint returns 404 that seems fine to me.

When you are activating the loadMetadataFormat, from where should you get the schema to validate it when not from a successful response? If you set it to true and the function is not able to load it, there is no other way to run the validation.

You are able to overwrite the vctFether via the config and so implement your own logic. For me the normal way sounds logic that when somebody adds a URL, starting with http:// it's meant to be fetchable. This allows you for example to look up in a database for the schema, rather then fetching it from a URL.

So when you want to perform schema validation and you know you will get other values than URL in the vct that, you need to overwrite this function by passing it.