relocate verify merkle branch

rejig
ChainSafe · Nov 21, 2023 · 860784d · 860784d
1 parent d072280
commit 860784d
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Showing 3 changed files with 17 additions and 7 deletions.
diff --git a/packages/params/src/index.ts b/packages/params/src/index.ts
@@ -236,3 +236,7 @@ export const INTERVALS_PER_SLOT = 3;
 export const BYTES_PER_FIELD_ELEMENT = 32;
 export const BLOB_TX_TYPE = 0x03;
 export const VERSIONED_HASH_VERSION_KZG = 0x01;
+
+// ssz.deneb.BeaconBlockBody.getPathInfo(['blobKzgCommitments',0]).gindex
+export const KZG_COMMITMENT_GINDEX0 = ACTIVE_PRESET === PresetName.minimal ? 864 : 221184;
+export const KZG_COMMITMENT_SUBTREE_INDEX0 = KZG_COMMITMENT_GINDEX0 - 2 ** KZG_COMMITMENT_INCLUSION_PROOF_DEPTH;
diff --git a/packages/state-transition/src/util/blobs.ts b/packages/state-transition/src/util/blobs.ts
@@ -1,5 +1,6 @@
 import SHA256 from "@chainsafe/as-sha256";
-import {VERSIONED_HASH_VERSION_KZG} from "@lodestar/params";
+import {Tree} from "@chainsafe/persistent-merkle-tree";
+import {VERSIONED_HASH_VERSION_KZG, KZG_COMMITMENT_GINDEX0, ForkName} from "@lodestar/params";
 import {deneb, ssz, allForks} from "@lodestar/types";
 import {ChainForkConfig} from "@lodestar/config";
 
@@ -15,17 +16,19 @@ export function kzgCommitmentToVersionedHash(kzgCommitment: deneb.KZGCommitment)
 }
 
 export function computeInclusionProof(
-  _signedBlock: allForks.SignedBeaconBlock,
-  _blobsData: {blob: deneb.Blob; kzgProof: deneb.KZGProof; kzgCommitment: deneb.KZGCommitment}
+  fork: ForkName,
+  body: allForks.BeaconBlockBody,
+  index: number
 ): deneb.KzgCommitmentInclusionProof {
-  // TODO PR correctly implement the inclusion proof
-  return ssz.deneb.KzgCommitmentInclusionProof.defaultValue();
+  const bodyView = (ssz[fork].BeaconBlockBody as allForks.AllForksSSZTypes["BeaconBlockBody"]).toView(body);
+  const commitmentGindex = KZG_COMMITMENT_GINDEX0 + index;
+  return new Tree(bodyView.node).getSingleProof(BigInt(commitmentGindex));
 }
 
 export function computeBlobSidecars(
   config: ChainForkConfig,
   signedBlock: allForks.SignedBeaconBlock,
-  contents: deneb.Contents
+  contents: deneb.Contents & {kzgCommitmentInclusionProofs?: deneb.KzgCommitmentInclusionProof[]}
 ): deneb.BlobSidecars {
   const blobKzgCommitments = (signedBlock as deneb.SignedBeaconBlock).message.body.blobKzgCommitments;
   if (blobKzgCommitments === undefined) {
@@ -34,11 +37,13 @@ export function computeBlobSidecars(
 
   const blockHeader = blockToHeader(config, signedBlock.message);
   const signedBlockHeader = {message: blockHeader, signature: signedBlock.signature};
+  const fork = config.getForkName(blockHeader.slot);
 
   return blobKzgCommitments.map((kzgCommitment, index) => {
     const blob = contents.blobs[index];
     const kzgProof = contents.kzgProofs[index];
-    const kzgCommitmentInclusionProof = computeInclusionProof(signedBlock, {blob, kzgProof, kzgCommitment});
+    const kzgCommitmentInclusionProof =
+      contents.kzgCommitmentInclusionProofs?.[index] ?? computeInclusionProof(fork, signedBlock.message.body, index);
 
     return {index, blob, kzgCommitment, kzgProof, signedBlockHeader, kzgCommitmentInclusionProof};
   });

diff --git a/packages/state-transition/src/util/index.ts b/packages/state-transition/src/util/index.ts
@@ -24,3 +24,4 @@ export * from "./slot.js";
 export * from "./syncCommittee.js";
 export * from "./validator.js";
 export * from "./weakSubjectivity.js";
+export * from "./verifyMerkleBranch.js";