nimbus-eth2/beacon_chain/spec/helpers_el.nim
Etan Kissling a597fe95fa
check blob versioned hashes when no EL is connected (#6501)
* check blob versioned hashes when no EL is connected

When no EL is conencted, we have to at the very least ensure that the
data in the beacon block is consistent with the execution payload.
We already do this for the block hash, but also have to do it for the
`blob_kzg_commitments`. To validate that they are linked with the
execution payload, we have to RLP decode all EIP-4844 blob transactions
and compare their blob versioned hashes with the hashed commitments.

* simplify loop in case where `blob_versioned_hashes` doesn't exist

* skip blob transaction parsing pre Deneb
2024-08-22 06:04:03 +00:00

47 lines
2.1 KiB
Nim

# beacon_chain
# Copyright (c) 2024 Status Research & Development GmbH
# Licensed and distributed under either of
# * MIT license (license terms in the root directory or at https://opensource.org/licenses/MIT).
# * Apache v2 license (license terms in the root directory or at https://www.apache.org/licenses/LICENSE-2.0).
# at your option. This file may not be copied, modified, or distributed except according to those terms.
{.push raises: [].}
import
std/typetraits,
eth/common/eth_types_rlp,
"."/[helpers, state_transition_block]
func readExecutionTransaction(
txBytes: bellatrix.Transaction): Result[ExecutionTransaction, string] =
# Nim 2.0.8: `rlp.decode(distinctBase(txBytes), ExecutionTransaction)`
# uses the generic `read` from `rlp.nim` instead of the specific `read`
# from `eth_types_rlp.nim`, leading to compilation error.
# Doing this in two steps works around this resolution order issue.
var rlp = rlpFromBytes(distinctBase(txBytes))
try:
ok rlp.read(ExecutionTransaction)
except RlpError as exc:
err("Invalid transaction: " & exc.msg)
# https://github.com/ethereum/consensus-specs/blob/v1.5.0-alpha.4/specs/deneb/beacon-chain.md#is_valid_versioned_hashes
func is_valid_versioned_hashes*(blck: ForkyBeaconBlock): Result[void, string] =
static: doAssert typeof(blck).kind >= ConsensusFork.Deneb
template transactions: untyped = blck.body.execution_payload.transactions
template commitments: untyped = blck.body.blob_kzg_commitments
var i = 0
for txBytes in transactions:
if txBytes.len == 0 or txBytes[0] != TxEip4844.byte:
continue # Only blob transactions may have blobs
let tx = ? txBytes.readExecutionTransaction()
for vHash in tx.versionedHashes:
if commitments.len <= i:
return err("Extra blobs without matching `blob_kzg_commitments`")
if vHash.data != kzg_commitment_to_versioned_hash(commitments[i]):
return err("Invalid `blob_versioned_hash` at index " & $i)
inc i
if i != commitments.len:
return err("Extra `blob_kzg_commitments` without matching blobs")
ok()