Integrate payload attestations into validator duties

[Tomi-3-0]

• Fix: Sign PayloadAttestationData instead of full message per spec
• Integrate payload attestations into validator duty cycle

[github-actions]

Unit Test Results

       12 files  ±0    2 436 suites  ±0   48m 55s ⏱️ - 6m 52s
12 680 tests +2  12 115 ✔️ +2  565 💤 ±0  0 ❌ ±0 
63 724 runs  +8  62 996 ✔️ +8  728 💤 ±0  0 ❌ ±0 

Results for commit 0480608. ± Comparison against base commit 737861d.

♻️ This comment has been updated with latest results.

[tersec]

It would be better to just check for the existence of the key, less database I/O and less memory usage, similar to how

nimbus-eth2/beacon_chain/beacon_chain_db.nim

Lines 1277 to 1323 in b186c99

	proc containsBlock*(db: BeaconChainDBV0, key: Eth2Digest): bool =
	db.backend.contains(subkey(phase0.SignedBeaconBlock, key)).expectDb()
	proc containsBlock*[X: ForkyTrustedSignedBeaconBlock](
	db: BeaconChainDB, key: Eth2Digest, T: typedesc[X]): bool =
	const consensusFork = T.kind
	var res =
	db.blocks[consensusFork] != nil and
	db.blocks[consensusFork].contains(key.data).expectDb()
	when consensusFork < ConsensusFork.Altair:
	# During initial releases phase0, we stored states in a different table
	res = res or db.v0.containsBlock(key)
	res
	proc containsBlock*(db: BeaconChainDB, key: Eth2Digest, fork: ConsensusFork): bool =
	case fork
	of ConsensusFork.Phase0:
	containsBlock(db, key, phase0.TrustedSignedBeaconBlock)
	else:
	db.blocks[fork] != nil and
	db.blocks[fork].contains(key.data).expectDb()
	proc containsBlock*(db: BeaconChainDB, key: Eth2Digest): bool =
	for fork in countdown(ConsensusFork.high, ConsensusFork.low):
	if db.containsBlock(key, fork): return true
	false
	proc containsState*(db: BeaconChainDBV0, key: Eth2Digest): bool =
	let sk = subkey(Phase0BeaconStateNoImmutableValidators, key)
	db.stateStore.contains(sk).expectDb() or
	db.backend.contains(sk).expectDb() or
	db.backend.contains(subkey(phase0.BeaconState, key)).expectDb()
	proc containsState*(db: BeaconChainDB, fork: ConsensusFork, key: Eth2Digest,
	legacy: bool = true): bool =
	if db.statesNoVal[fork] == nil: return false
	if db.statesNoVal[fork].contains(key.data).expectDb(): return true
	(legacy and fork == ConsensusFork.Phase0 and db.v0.containsState(key))
	proc containsState*(db: BeaconChainDB, key: Eth2Digest, legacy: bool = true): bool =
	for fork in countdown(ConsensusFork.high, ConsensusFork.low):
	if db.statesNoVal[fork] != nil and
	db.statesNoVal[fork].contains(key.data).expectDb(): return true
	(legacy and db.v0.containsState(key))

work, i.e. a contains function in the database layer.

These also end up being conveniently testable insofar as there are tests for put/get/del.

That said, I'm not sure checking for blobs in the database at all is the right approach. For example, blobs can't in general be reconstructed unless one has at least half the columns, but nodes which have fewer than half the columns are also expected to provide payload attestations, because neither https://github.com/ethereum/consensus-specs/blob/v1.6.1/specs/gloas/validator.md#payload-timeliness-committee nor https://github.com/ethereum/consensus-specs/blob/v1.6.1/specs/gloas/validator.md#constructing-a-payload-attestation specifies anything about the PTC needing to be made entirely of supernodes or light supernodes.

So I don't know if checkBlobDataAvailable is the right function to have, here.

[Tomi-3-0]

Exactly. I agree

[tersec]

7779b07 changes it to custody columns, not blobs, consistent with current spec interpretation.

[tersec]

[2025-12-09T00:14:52.688Z] /home/jenkins/workspace/tforms_linux_x86_64_main_PR-7783/beacon_chain/rpc/rest_debug_api.nim(31, 7) Error: type mismatch: got 'None' for 'getDataColumnSidecar' but expected 'proc'
[2025-12-09T00:14:52.688Z] make: *** [Makefile:453: nimbus_beacon_node] Error 1

[tersec]

The actual envelope here isn't used, so retrieving it from the database, allocating and copying it around, and returning it is pointless. Better to have a containsExecutionPayloadEnvelope function in beacon_chain_db and query that.

[Tomi-3-0]

I've removed the envelope check entirely and just check custody columns directly.
eliminating the envelope deserialization completely. The trade-off is checking custody columns even when there are no blobs, but since those are just fast SQL key lookups versus the expensive deserialisation

[tersec]

The column here isn't used, so retrieving it from the database, allocating and copying it around, and returning it is pointless. Better to have a containsDataColumnSidecar function in beacon_chain_db and query that.