@lodestar/beacon-node
Version:
A Typescript implementation of the beacon chain
276 lines • 14.6 kB
JavaScript
import { KZG_COMMITMENT_INCLUSION_PROOF_DEPTH, KZG_COMMITMENT_SUBTREE_INDEX0, isForkPostElectra, } from "@lodestar/params";
import { computeEpochAtSlot, computeStartSlotAtEpoch, getBlockHeaderProposerSignatureSetByHeaderSlot, getBlockHeaderProposerSignatureSetByParentStateSlot, } from "@lodestar/state-transition";
import { ssz } from "@lodestar/types";
import { byteArrayEquals, toRootHex, verifyMerkleBranch } from "@lodestar/utils";
import { kzg } from "../../util/kzg.js";
import { BlobSidecarErrorCode, BlobSidecarGossipError, BlobSidecarValidationError } from "../errors/blobSidecarError.js";
import { GossipAction } from "../errors/gossipValidation.js";
import { RegenCaller } from "../regen/index.js";
export async function validateGossipBlobSidecar(fork, chain, blobSidecar, subnet) {
const blobSlot = blobSidecar.signedBlockHeader.message.slot;
// [REJECT] The sidecar's index is consistent with `MAX_BLOBS_PER_BLOCK` -- i.e. `blob_sidecar.index < MAX_BLOBS_PER_BLOCK`.
const maxBlobsPerBlock = chain.config.getMaxBlobsPerBlock(computeEpochAtSlot(blobSlot));
if (blobSidecar.index >= maxBlobsPerBlock) {
throw new BlobSidecarGossipError(GossipAction.REJECT, {
code: BlobSidecarErrorCode.INDEX_TOO_LARGE,
blobIdx: blobSidecar.index,
maxBlobsPerBlock,
});
}
// [REJECT] The sidecar is for the correct subnet -- i.e. `compute_subnet_for_blob_sidecar(sidecar.index) == subnet_id`.
if (computeSubnetForBlobSidecar(fork, chain.config, blobSidecar.index) !== subnet) {
throw new BlobSidecarGossipError(GossipAction.REJECT, {
code: BlobSidecarErrorCode.INVALID_INDEX,
blobIdx: blobSidecar.index,
subnet,
});
}
// [IGNORE] The sidecar is not from a future slot (with a MAXIMUM_GOSSIP_CLOCK_DISPARITY allowance) --
// i.e. validate that sidecar.slot <= current_slot (a client MAY queue future blocks for processing at
// the appropriate slot).
const currentSlotWithGossipDisparity = chain.clock.currentSlotWithGossipDisparity;
if (currentSlotWithGossipDisparity < blobSlot) {
throw new BlobSidecarGossipError(GossipAction.IGNORE, {
code: BlobSidecarErrorCode.FUTURE_SLOT,
currentSlot: currentSlotWithGossipDisparity,
blockSlot: blobSlot,
});
}
// [IGNORE] The sidecar is from a slot greater than the latest finalized slot -- i.e. validate that
// sidecar.slot > compute_start_slot_at_epoch(state.finalized_checkpoint.epoch)
const finalizedCheckpoint = chain.forkChoice.getFinalizedCheckpoint();
const finalizedSlot = computeStartSlotAtEpoch(finalizedCheckpoint.epoch);
if (blobSlot <= finalizedSlot) {
throw new BlobSidecarGossipError(GossipAction.IGNORE, {
code: BlobSidecarErrorCode.WOULD_REVERT_FINALIZED_SLOT,
blockSlot: blobSlot,
finalizedSlot,
});
}
// Check if the block is already known. We know it is post-finalization, so it is sufficient to check the fork choice.
//
// In normal operation this isn't necessary, however it is useful immediately after a
// reboot if the `observed_block_producers` cache is empty. In that case, without this
// check, we will load the parent and state from disk only to find out later that we
// already know this block.
const blockRoot = ssz.phase0.BeaconBlockHeader.hashTreeRoot(blobSidecar.signedBlockHeader.message);
const blockHex = toRootHex(blockRoot);
if (chain.forkChoice.getBlockHexDefaultStatus(blockHex) !== null) {
throw new BlobSidecarGossipError(GossipAction.IGNORE, { code: BlobSidecarErrorCode.ALREADY_KNOWN, root: blockHex });
}
// TODO: freetheblobs - check for badblock
// TODO: freetheblobs - check that its first blob with valid signature
// _[IGNORE]_ The blob's block's parent (defined by `sidecar.block_parent_root`) has been seen (via both
// gossip and non-gossip sources) (a client MAY queue blocks for processing once the parent block is
// retrieved).
const parentRoot = toRootHex(blobSidecar.signedBlockHeader.message.parentRoot);
const parentBlock = chain.forkChoice.getBlockHexDefaultStatus(parentRoot);
if (parentBlock === null) {
// If fork choice does *not* consider the parent to be a descendant of the finalized block,
// then there are two more cases:
//
// 1. We have the parent stored in our database. Because fork-choice has confirmed the
// parent is *not* in our post-finalization DAG, all other blocks must be either
// pre-finalization or conflicting with finalization.
// 2. The parent is unknown to us, we probably want to download it since it might actually
// descend from the finalized root.
// (Non-Lighthouse): Since we prune all blocks non-descendant from finalized checking the `db.block` database won't be useful to guard
// against known bad fork blocks, so we throw PARENT_UNKNOWN for cases (1) and (2)
throw new BlobSidecarGossipError(GossipAction.IGNORE, {
code: BlobSidecarErrorCode.PARENT_UNKNOWN,
parentRoot,
blockRoot: blockHex,
slot: blobSlot,
});
}
// [REJECT] The blob is from a higher slot than its parent.
if (parentBlock.slot >= blobSlot) {
throw new BlobSidecarGossipError(GossipAction.IGNORE, {
code: BlobSidecarErrorCode.NOT_LATER_THAN_PARENT,
parentSlot: parentBlock.slot,
slot: blobSlot,
});
}
// getBlockSlotState also checks for whether the current finalized checkpoint is an ancestor of the block.
// As a result, we throw an IGNORE (whereas the spec says we should REJECT for this scenario).
// this is something we should change this in the future to make the code airtight to the spec.
// [IGNORE] The block's parent (defined by block.parent_root) has been seen (via both gossip and non-gossip sources) (a client MAY queue blocks for processing once the parent block is retrieved).
// [REJECT] The block's parent (defined by block.parent_root) passes validation.
const blockState = await chain.regen
.getBlockSlotState(parentBlock, blobSlot, { dontTransferCache: true }, RegenCaller.validateGossipBlock)
.catch(() => {
throw new BlobSidecarGossipError(GossipAction.IGNORE, {
code: BlobSidecarErrorCode.PARENT_UNKNOWN,
parentRoot,
blockRoot: blockHex,
slot: blobSlot,
});
});
// [REJECT] The proposer signature, signed_beacon_block.signature, is valid with respect to the proposer_index pubkey.
const signature = blobSidecar.signedBlockHeader.signature;
if (!chain.seenBlockInputCache.isVerifiedProposerSignature(blobSlot, blockHex, signature)) {
const signatureSet = getBlockHeaderProposerSignatureSetByParentStateSlot(chain.config, blockState.slot, blobSidecar.signedBlockHeader);
// Don't batch so verification is not delayed
if (!(await chain.bls.verifySignatureSets([signatureSet], { verifyOnMainThread: true }))) {
throw new BlobSidecarGossipError(GossipAction.REJECT, {
code: BlobSidecarErrorCode.PROPOSAL_SIGNATURE_INVALID,
blockRoot: blockHex,
index: blobSidecar.index,
slot: blobSlot,
});
}
chain.seenBlockInputCache.markVerifiedProposerSignature(blobSlot, blockHex, signature);
}
// verify if the blob inclusion proof is correct
if (!validateBlobSidecarInclusionProof(blobSidecar)) {
throw new BlobSidecarGossipError(GossipAction.REJECT, {
code: BlobSidecarErrorCode.INCLUSION_PROOF_INVALID,
slot: blobSidecar.signedBlockHeader.message.slot,
blobIdx: blobSidecar.index,
});
}
// _[IGNORE]_ The sidecar is the only sidecar with valid signature received for the tuple
// `(sidecar.block_root, sidecar.index)`
//
// This is already taken care of by the way we group the blobs in getFullBlockInput helper
// but may be an error can be thrown there for this
// _[REJECT]_ The sidecar is proposed by the expected `proposer_index` for the block's slot in the
// context of the current shuffling (defined by `block_parent_root`/`slot`)
// If the `proposer_index` cannot immediately be verified against the expected shuffling, the sidecar
// MAY be queued for later processing while proposers for the block's branch are calculated -- in such
// a case _do not_ `REJECT`, instead `IGNORE` this message.
const proposerIndex = blobSidecar.signedBlockHeader.message.proposerIndex;
if (blockState.getBeaconProposer(blobSlot) !== proposerIndex) {
throw new BlobSidecarGossipError(GossipAction.REJECT, {
code: BlobSidecarErrorCode.INCORRECT_PROPOSER,
proposerIndex,
});
}
// blob, proof and commitment as a valid BLS G1 point gets verified in batch validation
try {
await validateBlobsAndBlobProofs([blobSidecar.kzgCommitment], [blobSidecar.blob], [blobSidecar.kzgProof]);
}
catch (_e) {
throw new BlobSidecarGossipError(GossipAction.REJECT, {
code: BlobSidecarErrorCode.INVALID_KZG_PROOF,
blobIdx: blobSidecar.index,
});
}
}
/**
* Validate some blob sidecars in a block
*
* Requires the block to be known to the node
*
* NOTE: chain is optional to skip signature verification. Helpful for testing purposes and so that can control whether
* signature gets checked depending on the reqresp method that is being checked
*/
export async function validateBlockBlobSidecars(chain, blockSlot, blockRoot, blockBlobCount, blobSidecars) {
if (blobSidecars.length === 0) {
return;
}
if (blockBlobCount === 0) {
throw new BlobSidecarValidationError({
code: BlobSidecarErrorCode.INCORRECT_SIDECAR_COUNT,
slot: blockSlot,
expected: blockBlobCount,
actual: blobSidecars.length,
});
}
// Hash the first sidecar block header and compare the rest via (cheaper) equality
const firstSidecarSignedBlockHeader = blobSidecars[0].signedBlockHeader;
const firstSidecarBlockHeader = firstSidecarSignedBlockHeader.message;
const firstBlockRoot = ssz.phase0.BeaconBlockHeader.hashTreeRoot(firstSidecarBlockHeader);
if (!byteArrayEquals(blockRoot, firstBlockRoot)) {
throw new BlobSidecarValidationError({
code: BlobSidecarErrorCode.INCORRECT_BLOCK,
slot: blockSlot,
blobIdx: 0,
expected: toRootHex(blockRoot),
actual: toRootHex(firstBlockRoot),
}, "BlobSidecar doesn't match corresponding block");
}
if (chain !== null) {
const blockRootHex = toRootHex(blockRoot);
const signature = firstSidecarSignedBlockHeader.signature;
if (!chain.seenBlockInputCache.isVerifiedProposerSignature(blockSlot, blockRootHex, signature)) {
const signatureSet = getBlockHeaderProposerSignatureSetByHeaderSlot(chain.config, firstSidecarSignedBlockHeader);
if (!(await chain.bls.verifySignatureSets([signatureSet], {
verifyOnMainThread: true,
}))) {
throw new BlobSidecarValidationError({
code: BlobSidecarErrorCode.PROPOSAL_SIGNATURE_INVALID,
blockRoot: blockRootHex,
slot: blockSlot,
index: blobSidecars[0].index,
});
}
chain.seenBlockInputCache.markVerifiedProposerSignature(blockSlot, blockRootHex, signature);
}
}
const commitments = [];
const blobs = [];
const proofs = [];
for (let i = 0; i < blobSidecars.length; i++) {
const blobSidecar = blobSidecars[i];
const blobIndex = blobSidecar.index;
if (i !== 0 &&
!ssz.phase0.SignedBeaconBlockHeader.equals(blobSidecar.signedBlockHeader, firstSidecarSignedBlockHeader)) {
throw new BlobSidecarValidationError({
code: BlobSidecarErrorCode.INCORRECT_BLOCK,
slot: blockSlot,
blobIdx: blobIndex,
expected: toRootHex(blockRoot),
actual: "unknown - compared via equality",
}, "BlobSidecar doesn't match corresponding block");
}
if (!validateBlobSidecarInclusionProof(blobSidecar)) {
throw new BlobSidecarValidationError({
code: BlobSidecarErrorCode.INCLUSION_PROOF_INVALID,
slot: blockSlot,
blobIdx: blobIndex,
}, "BlobSidecar inclusion proof invalid");
}
commitments.push(blobSidecar.kzgCommitment);
blobs.push(blobSidecar.blob);
proofs.push(blobSidecar.kzgProof);
}
// Final batch KZG proof verification
let reason = undefined;
try {
if (!(await kzg.asyncVerifyBlobKzgProofBatch(blobs, commitments, proofs))) {
reason = "Invalid verifyBlobKzgProofBatch";
}
}
catch (e) {
reason = e.message;
}
if (reason !== undefined) {
throw new BlobSidecarValidationError({
code: BlobSidecarErrorCode.INVALID_KZG_PROOF_BATCH,
slot: blockSlot,
reason,
}, "BlobSidecar has invalid KZG proof batch");
}
}
export async function validateBlobsAndBlobProofs(expectedKzgCommitments, blobs, proofs) {
// assert verify_aggregate_kzg_proof(blobs, expected_kzg_commitments, kzg_aggregated_proof)
let isProofValid;
try {
isProofValid = await kzg.asyncVerifyBlobKzgProofBatch(blobs, expectedKzgCommitments, proofs);
}
catch (e) {
e.message = `Error on verifyBlobKzgProofBatch: ${e.message}`;
throw e;
}
if (!isProofValid) {
throw Error("Invalid verifyBlobKzgProofBatch");
}
}
export function validateBlobSidecarInclusionProof(blobSidecar) {
return verifyMerkleBranch(ssz.deneb.KZGCommitment.hashTreeRoot(blobSidecar.kzgCommitment), blobSidecar.kzgCommitmentInclusionProof, KZG_COMMITMENT_INCLUSION_PROOF_DEPTH, KZG_COMMITMENT_SUBTREE_INDEX0 + blobSidecar.index, blobSidecar.signedBlockHeader.message.bodyRoot);
}
function computeSubnetForBlobSidecar(fork, config, blobIndex) {
return (blobIndex % (isForkPostElectra(fork) ? config.BLOB_SIDECAR_SUBNET_COUNT_ELECTRA : config.BLOB_SIDECAR_SUBNET_COUNT));
}
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