Bounds checking about vc-bitstring-status-list HOT 6 CLOSED

2.4. Bounds checking (issue vc-status-list-2021#9)

See github issue vc-status-list-2021#9.

Brent Zundel: if the index is out of bounds... what should happen.

Manu Sporny: it should raise an error.
… if they are out of bounds, it should raise an error..

Michael Prorock: ill volunteer for a PR on this.

Kristina Yasuda: I don't disagree... throwing an error is fine, but perhaps we should define an error code?.
… are there error codes?.

Manu Sporny: checking the status index is part of the verification stage.
… that would cause verify to fail.
… it gets into protocol.

Kristina Yasuda: error message?.

Manu Sporny: all we can say is you should throw an error.
… we don't have error codes yet.
… there is no way to surface these to the caller, unless we talk about protocol like vc api.
… i don't think this spec, which is just data model and serialization, can say much about how errors are exposed.

Michael Prorock: i'm not opposed to including informative guidance.
… like 406 / not acceptable.
… normative path, we should say MUST throw an error.

Phil ASU: +1 to it should throw an error.

Michael Prorock: should users see it? we can't say anything about that.

Michael Prorock: +1 manu.

Manu Sporny: is there confusion over getting the list, like 404... vs during verification 406 might not make sense... maybe better 200 verified false.
… seems like a protocol trap.

Michael Prorock: agreed.

Kristina Yasuda: good point on retrieval vs verify in the bitmap.
… we should say 404 if its obvious is should be 404.

Manu Sporny: +1 kristina, not finding the status list should be a 404 and should be in the spec..

Kristina Yasuda: if we want to avoid protocol, error message is probably also a trap.

Manu Sporny: we can define an algorithmic error message.
… error_index_out_of_bounds and hand wave about it.
… languages / implementers can define how they want to handle it.

Michael Prorock: +1 manu, e.g. you MUST return an error that indicates that the index is out of range through ERR_ABOVE_MAX.