Merkle Proofs of KZG commitments (#13159)

* Merkle Proofs of KZG commitments

* fix mock

* Implement Merkle proof spectests

* Check Proof construction in spectests

* fix Merkle proof generator

* Add unit test

* add ssz package unit tests

* add benchmark

* fix typo in comment

* ProposerSlashing was repeated

* Terence's review

* move to consensus_blocks

* use existing error

config/fieldparams/mainnet.go

@@ -28,6 +28,7 @@ const (
 	MaxWithdrawalsPerPayload              = 16            // MaxWithdrawalsPerPayloadLength defines the maximum number of withdrawals that can be included in a payload.
 	MaxBlobsPerBlock                      = 6             // MaxBlobsPerBlock defines the maximum number of blobs with respect to consensus rule can be included in a block.
 	MaxBlobCommitmentsPerBlock            = 4096          // MaxBlobCommitmentsPerBlock defines the theoretical limit of blobs can be included in a block.
+	LogMaxBlobCommitments                 = 12            // Log_2 of MaxBlobCommitmentsPerBlock
 	BlobLength                            = 131072        // BlobLength defines the byte length of a blob.
 	BlobSize                              = 131072        // defined to match blob.size in bazel ssz codegen
 )

config/fieldparams/minimal.go

@@ -28,6 +28,7 @@ const (
 	MaxWithdrawalsPerPayload              = 4             // MaxWithdrawalsPerPayloadLength defines the maximum number of withdrawals that can be included in a payload.
 	MaxBlobsPerBlock                      = 6             // MaxBlobsPerBlock defines the maximum number of blobs with respect to consensus rule can be included in a block.
 	MaxBlobCommitmentsPerBlock            = 16            // MaxBlobCommitmentsPerBlock defines the theoretical limit of blobs can be included in a block.
+	LogMaxBlobCommitments                 = 4             // Log_2 of MaxBlobCommitmentsPerBlock
 	BlobLength                            = 4             // BlobLength defines the byte length of a blob.
 	BlobSize                              = 128           // defined to match blob.size in bazel ssz codegen
 )

consensus-types/blocks/BUILD.bazel

@@ -6,6 +6,7 @@ go_library(
         "execution.go",
         "factory.go",
         "getters.go",
+        "kzg.go",
         "proto.go",
         "roblob.go",
         "roblock.go",
@@ -16,9 +17,11 @@ go_library(
     visibility = ["//visibility:public"],
     deps = [
         "//config/fieldparams:go_default_library",
+        "//config/params:go_default_library",
         "//consensus-types:go_default_library",
         "//consensus-types/interfaces:go_default_library",
         "//consensus-types/primitives:go_default_library",
+        "//container/trie:go_default_library",
         "//encoding/bytesutil:go_default_library",
         "//encoding/ssz:go_default_library",
         "//math:go_default_library",
@@ -28,6 +31,7 @@ go_library(
         "//runtime/version:go_default_library",
         "@com_github_pkg_errors//:go_default_library",
         "@com_github_prysmaticlabs_fastssz//:go_default_library",
+        "@com_github_prysmaticlabs_gohashtree//:go_default_library",
         "@com_github_sirupsen_logrus//:go_default_library",
         "@org_golang_google_protobuf//proto:go_default_library",
     ],
@@ -39,6 +43,7 @@ go_test(
         "execution_test.go",
         "factory_test.go",
         "getters_test.go",
+        "kzg_test.go",
         "proto_test.go",
         "roblob_test.go",
         "roblock_test.go",
@@ -49,6 +54,7 @@ go_test(
         "//consensus-types:go_default_library",
         "//consensus-types/interfaces:go_default_library",
         "//consensus-types/primitives:go_default_library",
+        "//container/trie:go_default_library",
         "//encoding/bytesutil:go_default_library",
         "//proto/engine/v1:go_default_library",
         "//proto/prysm/v1alpha1:go_default_library",
@@ -58,5 +64,6 @@ go_test(
         "//testing/require:go_default_library",
         "@com_github_prysmaticlabs_fastssz//:go_default_library",
         "@com_github_prysmaticlabs_go_bitfield//:go_default_library",
+        "@com_github_prysmaticlabs_gohashtree//:go_default_library",
     ],
 )

consensus-types/blocks/getters.go

@@ -1097,6 +1097,11 @@ func (b *BeaconBlockBody) BlobKzgCommitments() ([][]byte, error) {
 	}
 }
 
+// Version returns the version of the beacon block body
+func (b *BeaconBlockBody) Version() int {
+	return b.version
+}
+
 // HashTreeRoot returns the ssz root of the block body.
 func (b *BeaconBlockBody) HashTreeRoot() ([field_params.RootLength]byte, error) {
 	pb, err := b.Proto()

consensus-types/blocks/kzg.go

@@ -0,0 +1,192 @@
+package blocks
+
+import (
+	"github.com/pkg/errors"
+	"github.com/prysmaticlabs/gohashtree"
+	field_params "github.com/prysmaticlabs/prysm/v4/config/fieldparams"
+	"github.com/prysmaticlabs/prysm/v4/config/params"
+	"github.com/prysmaticlabs/prysm/v4/consensus-types/interfaces"
+	"github.com/prysmaticlabs/prysm/v4/container/trie"
+	"github.com/prysmaticlabs/prysm/v4/encoding/ssz"
+	"github.com/prysmaticlabs/prysm/v4/runtime/version"
+)
+
+const (
+	bodyLength    = 12 // The number of elements in the BeaconBlockBody Container
+	logBodyLength = 4  // The log 2 of bodyLength
+	kzgPosition   = 11 // The index of the KZG commitment list in the Body
+)
+
+var (
+	errInvalidIndex = errors.New("index out of bounds")
+)
+
+// MerkleProofKZGCommitment constructs a Merkle proof of inclusion of the KZG
+// commitment of index `index` into the Beacon Block with the given `body`
+func MerkleProofKZGCommitment(body interfaces.ReadOnlyBeaconBlockBody, index int) ([][]byte, error) {
+	bodyVersion := body.Version()
+	if bodyVersion < version.Deneb {
+		return nil, errUnsupportedBeaconBlockBody
+	}
+	commitments, err := body.BlobKzgCommitments()
+	if err != nil {
+		return nil, err
+	}
+	proof, err := bodyProof(commitments, index)
+	if err != nil {
+		return nil, err
+	}
+	membersRoots, err := topLevelRoots(body)
+	if err != nil {
+		return nil, err
+	}
+	sparse, err := trie.GenerateTrieFromItems(membersRoots, logBodyLength)
+	if err != nil {
+		return nil, err
+	}
+	topProof, err := sparse.MerkleProof(kzgPosition)
+	if err != nil {
+		return nil, err
+	}
+	// sparse.MerkleProof always includes the length of the slice this is
+	// why we remove the last element that is not needed in topProof
+	proof = append(proof, topProof[:len(topProof)-1]...)
+	return proof, nil
+}
+
+// leavesFromCommitments hashes each commitment to construct a slice of roots
+func leavesFromCommitments(commitments [][]byte) [][]byte {
+	leaves := make([][]byte, len(commitments))
+	for i, kzg := range commitments {
+		chunk := make([][32]byte, 2)
+		copy(chunk[0][:], kzg)
+		copy(chunk[1][:], kzg[field_params.RootLength:])
+		gohashtree.HashChunks(chunk, chunk)
+		leaves[i] = chunk[0][:]
+	}
+	return leaves
+}
+
+// bodyProof returns the Merkle proof of the subtree up to the root of the KZG
+// commitment list.
+func bodyProof(commitments [][]byte, index int) ([][]byte, error) {
+	if index < 0 || index >= len(commitments) {
+		return nil, errInvalidIndex
+	}
+	leaves := leavesFromCommitments(commitments)
+	sparse, err := trie.GenerateTrieFromItems(leaves, field_params.LogMaxBlobCommitments)
+	if err != nil {
+		return nil, err
+	}
+	proof, err := sparse.MerkleProof(index)
+	if err != nil {
+		return nil, err
+	}
+	return proof, err
+}
+
+// topLevelRoots computes the slice with the roots of each element in the
+// BeaconBlockBody. Notice that the KZG commitments root is not needed for the
+// proof computation thus it's omitted
+func topLevelRoots(body interfaces.ReadOnlyBeaconBlockBody) ([][]byte, error) {
+	layer := make([][]byte, bodyLength)
+	for i := range layer {
+		layer[i] = make([]byte, 32)
+	}
+
+	// Randao Reveal
+	randao := body.RandaoReveal()
+	root, err := ssz.MerkleizeByteSliceSSZ(randao[:])
+	if err != nil {
+		return nil, err
+	}
+	copy(layer[0], root[:])
+
+	// eth1_data
+	eth1 := body.Eth1Data()
+	root, err = eth1.HashTreeRoot()
+	if err != nil {
+		return nil, err
+	}
+	copy(layer[1], root[:])
+
+	// graffiti
+	root = body.Graffiti()
+	copy(layer[2], root[:])
+
+	// Proposer slashings
+	ps := body.ProposerSlashings()
+	root, err = ssz.MerkleizeListSSZ(ps, params.BeaconConfig().MaxProposerSlashings)
+	if err != nil {
+		return nil, err
+	}
+	copy(layer[3], root[:])
+
+	// Attester slashings
+	as := body.AttesterSlashings()
+	root, err = ssz.MerkleizeListSSZ(as, params.BeaconConfig().MaxAttesterSlashings)
+	if err != nil {
+		return nil, err
+	}
+	copy(layer[4], root[:])
+
+	// Attestations
+	att := body.Attestations()
+	root, err = ssz.MerkleizeListSSZ(att, params.BeaconConfig().MaxAttestations)
+	if err != nil {
+		return nil, err
+	}
+	copy(layer[5], root[:])
+
+	// Deposits
+	dep := body.Deposits()
+	root, err = ssz.MerkleizeListSSZ(dep, params.BeaconConfig().MaxDeposits)
+	if err != nil {
+		return nil, err
+	}
+	copy(layer[6], root[:])
+
+	// Voluntary Exits
+	ve := body.VoluntaryExits()
+	root, err = ssz.MerkleizeListSSZ(ve, params.BeaconConfig().MaxVoluntaryExits)
+	if err != nil {
+		return nil, err
+	}
+	copy(layer[7], root[:])
+
+	// Sync Aggregate
+	sa, err := body.SyncAggregate()
+	if err != nil {
+		return nil, err
+	}
+	root, err = sa.HashTreeRoot()
+	if err != nil {
+		return nil, err
+	}
+	copy(layer[8], root[:])
+
+	// Execution Payload
+	ep, err := body.Execution()
+	if err != nil {
+		return nil, err
+	}
+	root, err = ep.HashTreeRoot()
+	if err != nil {
+		return nil, err
+	}
+	copy(layer[9], root[:])
+
+	// BLS Changes
+	bls, err := body.BLSToExecutionChanges()
+	if err != nil {
+		return nil, err
+	}
+	root, err = ssz.MerkleizeListSSZ(bls, params.BeaconConfig().MaxBlsToExecutionChanges)
+	if err != nil {
+		return nil, err
+	}
+	copy(layer[10], root[:])
+
+	// KZG commitments is not needed
+	return layer, nil
+}

consensus-types/blocks/kzg_test.go

@@ -0,0 +1,130 @@
+package blocks
+
+import (
+	"math/rand"
+	"testing"
+
+	"github.com/prysmaticlabs/gohashtree"
+	fieldparams "github.com/prysmaticlabs/prysm/v4/config/fieldparams"
+	"github.com/prysmaticlabs/prysm/v4/container/trie"
+	enginev1 "github.com/prysmaticlabs/prysm/v4/proto/engine/v1"
+	ethpb "github.com/prysmaticlabs/prysm/v4/proto/prysm/v1alpha1"
+	"github.com/prysmaticlabs/prysm/v4/testing/require"
+)
+
+func Test_MerkleProofKZGCommitment_Altair(t *testing.T) {
+	kzgs := make([][]byte, 3)
+	kzgs[0] = make([]byte, 48)
+	_, err := rand.Read(kzgs[0])
+	require.NoError(t, err)
+	kzgs[1] = make([]byte, 48)
+	_, err = rand.Read(kzgs[1])
+	require.NoError(t, err)
+	kzgs[2] = make([]byte, 48)
+	_, err = rand.Read(kzgs[2])
+	require.NoError(t, err)
+	pbBody := &ethpb.BeaconBlockBodyAltair{}
+
+	body, err := NewBeaconBlockBody(pbBody)
+	require.NoError(t, err)
+	_, err = MerkleProofKZGCommitment(body, 0)
+	require.ErrorIs(t, errUnsupportedBeaconBlockBody, err)
+}
+
+func Test_MerkleProofKZGCommitment(t *testing.T) {
+	kzgs := make([][]byte, 3)
+	kzgs[0] = make([]byte, 48)
+	_, err := rand.Read(kzgs[0])
+	require.NoError(t, err)
+	kzgs[1] = make([]byte, 48)
+	_, err = rand.Read(kzgs[1])
+	require.NoError(t, err)
+	kzgs[2] = make([]byte, 48)
+	_, err = rand.Read(kzgs[2])
+	require.NoError(t, err)
+	pbBody := &ethpb.BeaconBlockBodyDeneb{
+		SyncAggregate: &ethpb.SyncAggregate{
+			SyncCommitteeBits:      make([]byte, fieldparams.SyncAggregateSyncCommitteeBytesLength),
+			SyncCommitteeSignature: make([]byte, fieldparams.BLSSignatureLength),
+		},
+		ExecutionPayload: &enginev1.ExecutionPayloadDeneb{
+			ParentHash:    make([]byte, fieldparams.RootLength),
+			FeeRecipient:  make([]byte, 20),
+			StateRoot:     make([]byte, fieldparams.RootLength),
+			ReceiptsRoot:  make([]byte, fieldparams.RootLength),
+			LogsBloom:     make([]byte, 256),
+			PrevRandao:    make([]byte, fieldparams.RootLength),
+			BaseFeePerGas: make([]byte, fieldparams.RootLength),
+			BlockHash:     make([]byte, fieldparams.RootLength),
+			Transactions:  make([][]byte, 0),
+			ExtraData:     make([]byte, 0),
+		},
+		Eth1Data: &ethpb.Eth1Data{
+			DepositRoot: make([]byte, fieldparams.RootLength),
+			BlockHash:   make([]byte, fieldparams.RootLength),
+		},
+		BlobKzgCommitments: kzgs,
+	}
+
+	body, err := NewBeaconBlockBody(pbBody)
+	require.NoError(t, err)
+	index := 1
+	_, err = MerkleProofKZGCommitment(body, 10)
+	require.ErrorIs(t, errInvalidIndex, err)
+	proof, err := MerkleProofKZGCommitment(body, index)
+	require.NoError(t, err)
+
+	chunk := make([][32]byte, 2)
+	copy(chunk[0][:], kzgs[index])
+	copy(chunk[1][:], kzgs[index][32:])
+	gohashtree.HashChunks(chunk, chunk)
+	root, err := body.HashTreeRoot()
+	require.NoError(t, err)
+	kzgOffset := 54 * fieldparams.MaxBlobCommitmentsPerBlock
+	require.Equal(t, true, trie.VerifyMerkleProof(root[:], chunk[0][:], uint64(index+kzgOffset), proof))
+}
+
+func Benchmark_MerkleProofKZGCommitment(b *testing.B) {
+	kzgs := make([][]byte, 3)
+	kzgs[0] = make([]byte, 48)
+	_, err := rand.Read(kzgs[0])
+	require.NoError(b, err)
+	kzgs[1] = make([]byte, 48)
+	_, err = rand.Read(kzgs[1])
+	require.NoError(b, err)
+	kzgs[2] = make([]byte, 48)
+	_, err = rand.Read(kzgs[2])
+	require.NoError(b, err)
+	pbBody := &ethpb.BeaconBlockBodyDeneb{
+		SyncAggregate: &ethpb.SyncAggregate{
+			SyncCommitteeBits:      make([]byte, fieldparams.SyncAggregateSyncCommitteeBytesLength),
+			SyncCommitteeSignature: make([]byte, fieldparams.BLSSignatureLength),
+		},
+		ExecutionPayload: &enginev1.ExecutionPayloadDeneb{
+			ParentHash:    make([]byte, fieldparams.RootLength),
+			FeeRecipient:  make([]byte, 20),
+			StateRoot:     make([]byte, fieldparams.RootLength),
+			ReceiptsRoot:  make([]byte, fieldparams.RootLength),
+			LogsBloom:     make([]byte, 256),
+			PrevRandao:    make([]byte, fieldparams.RootLength),
+			BaseFeePerGas: make([]byte, fieldparams.RootLength),
+			BlockHash:     make([]byte, fieldparams.RootLength),
+			Transactions:  make([][]byte, 0),
+			ExtraData:     make([]byte, 0),
+		},
+		Eth1Data: &ethpb.Eth1Data{
+			DepositRoot: make([]byte, fieldparams.RootLength),
+			BlockHash:   make([]byte, fieldparams.RootLength),
+		},
+		BlobKzgCommitments: kzgs,
+	}
+
+	body, err := NewBeaconBlockBody(pbBody)
+	require.NoError(b, err)
+	index := 1
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		_, err := MerkleProofKZGCommitment(body, index)
+		require.NoError(b, err)
+	}
+}

consensus-types/interfaces/beacon_block.go

@@ -59,6 +59,7 @@ type ReadOnlyBeaconBlock interface {
 // ReadOnlyBeaconBlockBody describes the method set employed by an object
 // that is a beacon block body.
 type ReadOnlyBeaconBlockBody interface {
+	Version() int
 	RandaoReveal() [field_params.BLSSignatureLength]byte
 	Eth1Data() *ethpb.Eth1Data
 	Graffiti() [field_params.RootLength]byte

consensus-types/mock/block.go

@@ -316,6 +316,10 @@ func (b *BeaconBlockBody) Attestations() []*eth.Attestation {
 	panic("implement me")
 }
 
+func (b *BeaconBlockBody) Version() int {
+	panic("implement me")
+}
+
 var _ interfaces.ReadOnlySignedBeaconBlock = &SignedBeaconBlock{}
 var _ interfaces.ReadOnlyBeaconBlock = &BeaconBlock{}
 var _ interfaces.ReadOnlyBeaconBlockBody = &BeaconBlockBody{}

encoding/ssz/BUILD.bazel

@@ -20,6 +20,7 @@ go_library(
         "@com_github_minio_sha256_simd//:go_default_library",
         "@com_github_pkg_errors//:go_default_library",
         "@com_github_prysmaticlabs_go_bitfield//:go_default_library",
+        "@com_github_prysmaticlabs_gohashtree//:go_default_library",
     ],
 )
 

encoding/ssz/merkleize.go

@@ -1,15 +1,15 @@
 package ssz
 
 import (
+	"encoding/binary"
+
+	"github.com/pkg/errors"
+	"github.com/prysmaticlabs/gohashtree"
 	"github.com/prysmaticlabs/prysm/v4/container/trie"
 	"github.com/prysmaticlabs/prysm/v4/crypto/hash/htr"
 )
 
-// Merkleize.go is mostly a directly copy of the same filename from
-// https://github.com/protolambda/zssz/blob/master/merkle/merkleize.go.
-// The reason the method is copied instead of imported is due to us using a
-// custom hasher interface for a reduced memory footprint when using
-// 'Merkleize'.
+var errInvalidNilSlice = errors.New("invalid empty slice")
 
 const (
 	mask0 = ^uint64((1 << (1 << iota)) - 1)
@@ -132,72 +132,6 @@ func Merkleize(hasher Hasher, count, limit uint64, leaf func(i uint64) []byte) (
 	return tmp[limitDepth]
 }
 
-// ConstructProof builds a merkle-branch of the given depth, at the given index (at that depth),
-// for a list of leafs of a balanced binary tree.
-func ConstructProof(hasher Hasher, count, limit uint64, leaf func(i uint64) []byte, index uint64) (branch [][32]byte) {
-	if count > limit {
-		panic("merkleizing list that is too large, over limit")
-	}
-	if index >= limit {
-		panic("index out of range, over limit")
-	}
-	if limit <= 1 {
-		return
-	}
-	depth := Depth(count)
-	limitDepth := Depth(limit)
-	branch = append(branch, trie.ZeroHashes[:limitDepth]...)
-
-	tmp := make([][32]byte, limitDepth+1)
-
-	j := uint8(0)
-	var hArr [32]byte
-	h := hArr[:]
-
-	merge := func(i uint64) {
-		// merge back up from bottom to top, as far as we can
-		for j = 0; ; j++ {
-			// if i is a sibling of index at the given depth,
-			// and i is the last index of the subtree to that depth,
-			// then put h into the branch
-			if (i>>j)^1 == (index>>j) && (((1<<j)-1)&i) == ((1<<j)-1) {
-				// insert sibling into the proof
-				branch[j] = hArr
-			}
-			// stop merging when we are in the left side of the next combi
-			if i&(uint64(1)<<j) == 0 {
-				// if we are at the count, we want to merge in zero-hashes for padding
-				if i == count && j < depth {
-					v := hasher.Combi(hArr, trie.ZeroHashes[j])
-					copy(h, v[:])
-				} else {
-					break
-				}
-			} else {
-				// keep merging up if we are the right side
-				v := hasher.Combi(tmp[j], hArr)
-				copy(h, v[:])
-			}
-		}
-		// store the merge result (may be no merge, i.e. bottom leaf node)
-		copy(tmp[j][:], h)
-	}
-
-	// merge in leaf by leaf.
-	for i := uint64(0); i < count; i++ {
-		copy(h, leaf(i))
-		merge(i)
-	}
-
-	// complement with 0 if empty, or if not the right power of 2
-	if (uint64(1) << depth) != count {
-		copy(h, trie.ZeroHashes[0][:])
-		merge(count)
-	}
-
-	return
-}
-
 // MerkleizeVector uses our optimized routine to hash a list of 32-byte
 // elements.
 func MerkleizeVector(elements [][32]byte, length uint64) [32]byte {
@@ -217,3 +151,52 @@ func MerkleizeVector(elements [][32]byte, length uint64) [32]byte {
 	}
 	return elements[0]
 }
+
+// Hashable is an interface representing objects that implement HashTreeRoot()
+type Hashable interface {
+	HashTreeRoot() ([32]byte, error)
+}
+
+// MerkleizeVectorSSZ hashes each element in the list and then returns the HTR
+// of the corresponding list of roots
+func MerkleizeVectorSSZ[T Hashable](elements []T, length uint64) ([32]byte, error) {
+	roots := make([][32]byte, len(elements))
+	var err error
+	for i, el := range elements {
+		roots[i], err = el.HashTreeRoot()
+		if err != nil {
+			return [32]byte{}, err
+		}
+	}
+	return MerkleizeVector(roots, length), nil
+}
+
+// MerkleizeListSSZ hashes each element in the list and then returns the HTR of
+// the list of corresponding roots, with the length mixed in.
+func MerkleizeListSSZ[T Hashable](elements []T, limit uint64) ([32]byte, error) {
+	body, err := MerkleizeVectorSSZ(elements, limit)
+	if err != nil {
+		return [32]byte{}, err
+	}
+	chunks := make([][32]byte, 2)
+	chunks[0] = body
+	binary.LittleEndian.PutUint64(chunks[1][:], uint64(len(elements)))
+	if err := gohashtree.Hash(chunks, chunks); err != nil {
+		return [32]byte{}, err
+	}
+	return chunks[0], err
+}
+
+// MerkleizeByteSliceSSZ hashes a byteslice by chunkifying it and returning the
+// corresponding HTR as if it were a fixed vector of bytes of the given length.
+func MerkleizeByteSliceSSZ(input []byte) ([32]byte, error) {
+	numChunks := (len(input) + 31) / 32
+	if numChunks == 0 {
+		return [32]byte{}, errInvalidNilSlice
+	}
+	chunks := make([][32]byte, numChunks)
+	for i := range chunks {
+		copy(chunks[i][:], input[32*i:])
+	}
+	return MerkleizeVector(chunks, uint64(numChunks)), nil
+}

encoding/ssz/merkleize_test.go

@@ -3,9 +3,12 @@ package ssz_test
 import (
 	"testing"
 
+	"github.com/prysmaticlabs/go-bitfield"
 	"github.com/prysmaticlabs/prysm/v4/crypto/hash"
 	"github.com/prysmaticlabs/prysm/v4/encoding/ssz"
+	ethpb "github.com/prysmaticlabs/prysm/v4/proto/prysm/v1alpha1"
 	"github.com/prysmaticlabs/prysm/v4/testing/assert"
+	"github.com/prysmaticlabs/prysm/v4/testing/require"
 )
 
 func TestGetDepth(t *testing.T) {
@@ -59,60 +62,74 @@ func TestMerkleizeNormalPath(t *testing.T) {
 	assert.Equal(t, expected, result)
 }
 
-func TestConstructProofCountGreaterThanLimit(t *testing.T) {
-	hashFn := ssz.NewHasherFunc(hash.CustomSHA256Hasher())
-	count := uint64(2)
-	limit := uint64(1)
-	chunks := [][]byte{{}}
-	leafIndexer := func(i uint64) []byte {
-		return chunks[i]
-	}
-	index := uint64(0)
-	defer func() {
-		if r := recover(); r == nil {
-			t.Errorf("The code did not panic.")
-		}
-	}()
-	ssz.ConstructProof(hashFn, count, limit, leafIndexer, index)
-}
-
-func TestConstructProofIndexGreaterThanEqualToLimit(t *testing.T) {
-	hashFn := ssz.NewHasherFunc(hash.CustomSHA256Hasher())
-	count := uint64(1)
-	limit := uint64(1)
-	chunks := [][]byte{{}}
-	leafIndexer := func(i uint64) []byte {
-		return chunks[i]
-	}
-	index := uint64(1)
-	defer func() {
-		if r := recover(); r == nil {
-			t.Errorf("The code did not panic.")
-		}
-	}()
-	ssz.ConstructProof(hashFn, count, limit, leafIndexer, index)
-}
-
-func TestConstructProofNormalPath(t *testing.T) {
-	hashFn := ssz.NewHasherFunc(hash.CustomSHA256Hasher())
-	count := uint64(2)
-	limit := uint64(3)
-	chunks := [][]byte{{1, 2, 3, 4}, {5, 6, 7, 8}, {9, 10, 11, 12}}
-	leafIndexer := func(i uint64) []byte {
-		return chunks[i]
-	}
-	index := uint64(1)
-	expected := [][32]byte{
-		{1, 2, 3, 4, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0},
-		{245, 165, 253, 66, 209, 106, 32, 48, 39, 152, 239, 110, 211, 9, 151, 155, 67, 0, 61, 35, 32, 217, 240, 232, 234, 152, 49, 169, 39, 89, 251, 75},
-	}
-	result := ssz.ConstructProof(hashFn, count, limit, leafIndexer, index)
-	assert.Equal(t, len(expected), len(result))
-	for i, v := range expected {
-		assert.DeepEqual(t, result[i], v)
-	}
-}
-
 func TestDepthOfOne(t *testing.T) {
 	assert.Equal(t, uint8(0), ssz.Depth(1))
 }
+
+func Test_MerkleizeVectorSSZ(t *testing.T) {
+	t.Run("empty vector", func(t *testing.T) {
+		attList := make([]*ethpb.Attestation, 0)
+		expected := [32]byte{83, 109, 152, 131, 127, 45, 209, 101, 165, 93, 94, 234, 233, 20, 133, 149, 68, 114, 213, 111, 36, 109, 242, 86, 191, 60, 174, 25, 53, 42, 18, 60}
+		length := uint64(16)
+		root, err := ssz.MerkleizeVectorSSZ(attList, length)
+		require.NoError(t, err)
+		require.Equal(t, expected, root)
+	})
+	t.Run("non empty vector", func(t *testing.T) {
+		sig := make([]byte, 96)
+		br := make([]byte, 32)
+		attList := make([]*ethpb.Attestation, 1)
+		attList[0] = &ethpb.Attestation{
+			AggregationBits: bitfield.Bitlist{0x01},
+			Data: &ethpb.AttestationData{
+				BeaconBlockRoot: br,
+				Source: &ethpb.Checkpoint{
+					Root: br,
+				},
+				Target: &ethpb.Checkpoint{
+					Root: br,
+				},
+			},
+			Signature: sig,
+		}
+		expected := [32]byte{199, 186, 55, 142, 200, 75, 219, 191, 66, 153, 100, 181, 200, 15, 143, 160, 25, 133, 105, 26, 183, 107, 10, 198, 232, 231, 107, 162, 243, 243, 56, 20}
+		length := uint64(16)
+		root, err := ssz.MerkleizeVectorSSZ(attList, length)
+		require.NoError(t, err)
+		require.Equal(t, expected, root)
+	})
+}
+
+func Test_MerkleizeListSSZ(t *testing.T) {
+	t.Run("empty vector", func(t *testing.T) {
+		attList := make([]*ethpb.Attestation, 0)
+		expected := [32]byte{121, 41, 48, 187, 213, 186, 172, 67, 188, 199, 152, 238, 73, 170, 129, 133, 239, 118, 187, 59, 68, 186, 98, 185, 29, 134, 174, 86, 158, 75, 181, 53}
+		length := uint64(16)
+		root, err := ssz.MerkleizeListSSZ(attList, length)
+		require.NoError(t, err)
+		require.Equal(t, expected, root)
+	})
+	t.Run("non empty vector", func(t *testing.T) {
+		sig := make([]byte, 96)
+		br := make([]byte, 32)
+		attList := make([]*ethpb.Attestation, 1)
+		attList[0] = &ethpb.Attestation{
+			AggregationBits: bitfield.Bitlist{0x01},
+			Data: &ethpb.AttestationData{
+				BeaconBlockRoot: br,
+				Source: &ethpb.Checkpoint{
+					Root: br,
+				},
+				Target: &ethpb.Checkpoint{
+					Root: br,
+				},
+			},
+			Signature: sig,
+		}
+		expected := [32]byte{161, 247, 30, 234, 219, 222, 154, 88, 7, 207, 6, 23, 46, 125, 135, 67, 225, 178, 217, 131, 113, 124, 242, 106, 194, 43, 205, 194, 49, 172, 232, 229}
+		length := uint64(16)
+		root, err := ssz.MerkleizeListSSZ(attList, length)
+		require.NoError(t, err)
+		require.Equal(t, expected, root)
+	})
+}

testing/spectest/shared/common/merkle_proof/BUILD.bazel

@@ -7,6 +7,8 @@ go_library(
     importpath = "github.com/prysmaticlabs/prysm/v4/testing/spectest/shared/common/merkle_proof",
     visibility = ["//visibility:public"],
     deps = [
+        "//config/fieldparams:go_default_library",
+        "//consensus-types/blocks:go_default_library",
         "//container/trie:go_default_library",
         "//testing/require:go_default_library",
         "//testing/spectest/shared/common/ssz_static:go_default_library",

testing/spectest/shared/common/merkle_proof/single_merkle_proof.go

@@ -9,6 +9,8 @@ import (
 	"github.com/bazelbuild/rules_go/go/tools/bazel"
 	"github.com/golang/snappy"
 	fssz "github.com/prysmaticlabs/fastssz"
+	field_params "github.com/prysmaticlabs/prysm/v4/config/fieldparams"
+	consensus_blocks "github.com/prysmaticlabs/prysm/v4/consensus-types/blocks"
 	"github.com/prysmaticlabs/prysm/v4/container/trie"
 	"github.com/prysmaticlabs/prysm/v4/testing/require"
 	"github.com/prysmaticlabs/prysm/v4/testing/spectest/shared/common/ssz_static"
@@ -16,6 +18,8 @@ import (
 	"github.com/prysmaticlabs/prysm/v4/testing/util"
 )
 
+const kzgOffset = 54 * field_params.MaxBlobCommitmentsPerBlock
+
 // SingleMerkleProof is the format used to read spectest Merkle Proof test data.
 type SingleMerkleProof struct {
 	Leaf      string   `json:"leaf"`
@@ -73,7 +77,21 @@ func runSingleMerkleProofTests(t *testing.T, config, forkOrPhase string, unmarsh
 				leaf, err := hex.DecodeString(proof.Leaf[2:])
 				require.NoError(t, err)
 
-				require.Equal(t, true, trie.VerifyMerkleProof(root[:], leaf, proof.LeafIndex, branch))
+				index := proof.LeafIndex
+				require.Equal(t, true, trie.VerifyMerkleProof(root[:], leaf, index, branch))
+				body, err := consensus_blocks.NewBeaconBlockBody(object)
+				if err != nil {
+					return
+				}
+				if index < kzgOffset || index > kzgOffset+field_params.MaxBlobsPerBlock {
+					return
+				}
+				localProof, err := consensus_blocks.MerkleProofKZGCommitment(body, int(index-kzgOffset))
+				require.NoError(t, err)
+				require.Equal(t, len(branch), len(localProof))
+				for i, root := range localProof {
+					require.DeepEqual(t, branch[i], root)
+				}
 			})
 		}
 	}