On `ELECTRA_FORK_EPOCH`, PeerDAS is not yet activated, hence the current
mechanism based on `BlobSidecar` is still in use. With EIP-7688, the
generalized indices of `BeaconBlockBody` get reindexed, changing the
length of the inclusion proof within the `BlobSidecar`. Because network
Req/Resp operations allow responses across fork boundaries, this creates
the need for a `ForkedBlobSidecar` in that layer, same as already done
for `ForkedSignedBeaconBock` for similar reasons.
Note: This PR is only needed if PeerDAS is adopted _after_ EIP-7688.
If PeerDAS is adopted _before_ EIP-7688, a similar PR may be needed for
forked columns. Coincidental `Forked` jank can only be fully avoided if
both features activate at the same epoch, actual changes to blobs aside.
Delaying EIP-7688 for sole purpose of epoch alignemnt is not worth it.
The fork digest determines the underlying data type on libp2p gossip,
so it's important to use the matching fork digest instead of picking
whatever wall epoch happens to be.
To avoid "forked" types creeping into `BlobSidecar`, move the reduction
to `BlobSidecarInfoObject` to the sole caller. The info object is fork
agnostic, so does not need "forked" if `BlobSidecar` ever updates.
* Fix blob syncing for Electra
`BlobSidecar` requests on libp2p have a context prefix based on:
> The `<context-bytes>` field is calculated as context =
> `compute_fork_digest(fork_version, genesis_validators_root)`
We currently only process blobs if that indicates Deneb, meaning that
on Electra we incorrectly report `InvalidContextBytes` and refuse to
process the blob response data.
Fix this, and also ensure that the code no longer needs maintenance
with every fork unrelated to blobs.
* fix
When no EL is connected, it is still required to validate the block hash
of `ExecutionPayload` to prevent attacks that trick us into attesting to
a circular chain with invalid in-between block hashes. This is already
done through Deneb but was still missing in Electra to be rectified now.
Etan Kissling
tersec
Eugene Kabanov
Kim De Mey
Jhett Black
andri lim