Host returns error when invalid cert is sent to proxy

[bxue-l2]

When there is an invalid cert i.e. the signature is wrong (parsing error itself is already handled within the client inside the derivation pipeline), proxy should inform the host about it.

The host should handle such error and only return empty bytes for all field element. The line to fix is here (https://github.com/Layr-Labs/hokulea/blob/master/bin/host/src/eigenda_fetcher/mod.rs#L150).

As such, the oracle client can detect it here https://github.com/Layr-Labs/hokulea/blob/master/crates/proof/src/eigenda_provider.rs#L90

[samlaf]

proxy should inform the host about it

This is during GET requests right? What is currently returned upon error? 400? 500? What's your suggestion for modifying proxy to have the information you need?

[bxue-l2]

Two solutions:

1. proxy returns an empty byte, not reporting an error. As such, the the frame_queue in the derivation pipeline will filter out the empty byte
2. proxy returns a special error code, such that the op-node daclient knows to discard the data

Currently as far as I understand, the error flow like below

1. https://github.com/ethereum-optimism/optimism/blob/develop/op-node/rollup/derive/l1_retrieval.go#L63
2. https://github.com/ethereum-optimism/optimism/blob/develop/op-alt-da/daclient.go#L53
3. https://github.com/ethereum-optimism/optimism/blob/develop/op-node/rollup/derive/altda_data_source.go#L93

I have gone deep when it got to 3, but from the comment it will continue to retry that cert, and essentially deadlock the system

[samlaf]

Definitely prefer returning an explicit error with http error code.

[bxue-l2]

As far as I can tell, this is a problem which proxy needs to address in order to prevent a malicious OP batcher. This issue should open under proxy repo

[bxue-l2]

related issue, Layr-Labs/eigenda-proxy#243 (comment)