eth/catalyst: implement getBlobsV2 (#31791)

Implements `engine_getBlobsV2` which is needed for PeerDAS.

---------

Co-authored-by: Felix Lange <fjl@twurst.com>

Author: MariusVanDerWijden

beacon/engine/types.go

@@ -123,6 +123,11 @@ type BlobAndProofV1 struct {
 	Proof hexutil.Bytes `json:"proof"`
 }
 
+type BlobAndProofV2 struct {
+	Blob       hexutil.Bytes   `json:"blob"`
+	CellProofs []hexutil.Bytes `json:"proofs"`
+}
+
 // JSON type overrides for ExecutionPayloadEnvelope.
 type executionPayloadEnvelopeMarshaling struct {
 	BlockValue *hexutil.Big
@@ -331,7 +336,9 @@ func BlockToExecutableData(block *types.Block, fees *big.Int, sidecars []*types.
 		for j := range sidecar.Blobs {
 			bundle.Blobs = append(bundle.Blobs, hexutil.Bytes(sidecar.Blobs[j][:]))
 			bundle.Commitments = append(bundle.Commitments, hexutil.Bytes(sidecar.Commitments[j][:]))
-			bundle.Proofs = append(bundle.Proofs, hexutil.Bytes(sidecar.Proofs[j][:]))
+		}
+		for _, proof := range sidecar.Proofs {
+			bundle.Proofs = append(bundle.Proofs, hexutil.Bytes(proof[:]))
 		}
 	}
 

beacon/engine/types_test.go

@@ -0,0 +1,56 @@
+// Copyright 2025 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package engine
+
+import (
+	"testing"
+
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/core/types"
+	"github.com/ethereum/go-ethereum/crypto/kzg4844"
+)
+
+func TestBlobs(t *testing.T) {
+	var (
+		emptyBlob          = new(kzg4844.Blob)
+		emptyBlobCommit, _ = kzg4844.BlobToCommitment(emptyBlob)
+		emptyBlobProof, _  = kzg4844.ComputeBlobProof(emptyBlob, emptyBlobCommit)
+		emptyCellProof, _  = kzg4844.ComputeCellProofs(emptyBlob)
+	)
+	header := types.Header{}
+	block := types.NewBlock(&header, &types.Body{}, nil, nil)
+
+	sidecarWithoutCellProofs := &types.BlobTxSidecar{
+		Blobs:       []kzg4844.Blob{*emptyBlob},
+		Commitments: []kzg4844.Commitment{emptyBlobCommit},
+		Proofs:      []kzg4844.Proof{emptyBlobProof},
+	}
+	env := BlockToExecutableData(block, common.Big0, []*types.BlobTxSidecar{sidecarWithoutCellProofs}, nil)
+	if len(env.BlobsBundle.Proofs) != 1 {
+		t.Fatalf("Expect 1 proof in blobs bundle, got %v", len(env.BlobsBundle.Proofs))
+	}
+
+	sidecarWithCellProofs := &types.BlobTxSidecar{
+		Blobs:       []kzg4844.Blob{*emptyBlob},
+		Commitments: []kzg4844.Commitment{emptyBlobCommit},
+		Proofs:      emptyCellProof,
+	}
+	env = BlockToExecutableData(block, common.Big0, []*types.BlobTxSidecar{sidecarWithCellProofs}, nil)
+	if len(env.BlobsBundle.Proofs) != 128 {
+		t.Fatalf("Expect 128 proofs in blobs bundle, got %v", len(env.BlobsBundle.Proofs))
+	}
+}

core/txpool/blobpool/blobpool.go

@@ -36,7 +36,6 @@ import (
 	"github.com/ethereum/go-ethereum/core/state"
 	"github.com/ethereum/go-ethereum/core/txpool"
 	"github.com/ethereum/go-ethereum/core/types"
-	"github.com/ethereum/go-ethereum/crypto/kzg4844"
 	"github.com/ethereum/go-ethereum/event"
 	"github.com/ethereum/go-ethereum/log"
 	"github.com/ethereum/go-ethereum/metrics"
@@ -1302,27 +1301,13 @@ func (p *BlobPool) GetMetadata(hash common.Hash) *txpool.TxMetadata {
 	}
 }
 
-// GetBlobs returns a number of blobs are proofs for the given versioned hashes.
+// GetBlobs returns a number of blobs and proofs for the given versioned hashes.
 // This is a utility method for the engine API, enabling consensus clients to
 // retrieve blobs from the pools directly instead of the network.
-func (p *BlobPool) GetBlobs(vhashes []common.Hash) ([]*kzg4844.Blob, []*kzg4844.Proof) {
-	// Create a map of the blob hash to indices for faster fills
-	var (
-		blobs  = make([]*kzg4844.Blob, len(vhashes))
-		proofs = make([]*kzg4844.Proof, len(vhashes))
-	)
-	index := make(map[common.Hash]int)
-	for i, vhash := range vhashes {
-		index[vhash] = i
-	}
-	// Iterate over the blob hashes, pulling transactions that fill it. Take care
-	// to also fill anything else the transaction might include (probably will).
-	for i, vhash := range vhashes {
-		// If already filled by a previous fetch, skip
-		if blobs[i] != nil {
-			continue
-		}
-		// Unfilled, retrieve the datastore item (in a short lock)
+func (p *BlobPool) GetBlobs(vhashes []common.Hash) []*types.BlobTxSidecar {
+	sidecars := make([]*types.BlobTxSidecar, len(vhashes))
+	for idx, vhash := range vhashes {
+		// Retrieve the datastore item (in a short lock)
 		p.lock.RLock()
 		id, exists := p.lookup.storeidOfBlob(vhash)
 		if !exists {
@@ -1342,16 +1327,24 @@ func (p *BlobPool) GetBlobs(vhashes []common.Hash) ([]*kzg4844.Blob, []*kzg4844.
 			log.Error("Blobs corrupted for traced transaction", "id", id, "err", err)
 			continue
 		}
-		// Fill anything requested, not just the current versioned hash
-		sidecar := item.BlobTxSidecar()
-		for j, blobhash := range item.BlobHashes() {
-			if idx, ok := index[blobhash]; ok {
-				blobs[idx] = &sidecar.Blobs[j]
-				proofs[idx] = &sidecar.Proofs[j]
-			}
+		sidecars[idx] = item.BlobTxSidecar()
+	}
+	return sidecars
+}
+
+// AvailableBlobs returns the number of blobs that are available in the subpool.
+func (p *BlobPool) AvailableBlobs(vhashes []common.Hash) int {
+	available := 0
+	for _, vhash := range vhashes {
+		// Retrieve the datastore item (in a short lock)
+		p.lock.RLock()
+		_, exists := p.lookup.storeidOfBlob(vhash)
+		p.lock.RUnlock()
+		if exists {
+			available++
 		}
 	}
-	return blobs, proofs
+	return available
 }
 
 // Add inserts a set of blob transactions into the pool if they pass validation (both

core/txpool/blobpool/blobpool_test.go

@@ -417,8 +417,23 @@ func verifyBlobRetrievals(t *testing.T, pool *BlobPool) {
 	for i := range testBlobVHashes {
 		copy(hashes[i][:], testBlobVHashes[i][:])
 	}
-	blobs, proofs := pool.GetBlobs(hashes)
-
+	sidecars := pool.GetBlobs(hashes)
+	var blobs []*kzg4844.Blob
+	var proofs []*kzg4844.Proof
+	for idx, sidecar := range sidecars {
+		if sidecar == nil {
+			blobs = append(blobs, nil)
+			proofs = append(proofs, nil)
+			continue
+		}
+		blobHashes := sidecar.BlobHashes()
+		for i, hash := range blobHashes {
+			if hash == hashes[idx] {
+				blobs = append(blobs, &sidecar.Blobs[i])
+				proofs = append(proofs, &sidecar.Proofs[i])
+			}
+		}
+	}
 	// Cross validate what we received vs what we wanted
 	if len(blobs) != len(hashes) || len(proofs) != len(hashes) {
 		t.Errorf("retrieved blobs/proofs size mismatch: have %d/%d, want %d", len(blobs), len(proofs), len(hashes))

core/txpool/legacypool/legacypool.go

@@ -35,7 +35,6 @@ import (
 	"github.com/ethereum/go-ethereum/core/state"
 	"github.com/ethereum/go-ethereum/core/txpool"
 	"github.com/ethereum/go-ethereum/core/types"
-	"github.com/ethereum/go-ethereum/crypto/kzg4844"
 	"github.com/ethereum/go-ethereum/event"
 	"github.com/ethereum/go-ethereum/log"
 	"github.com/ethereum/go-ethereum/metrics"
@@ -1063,12 +1062,6 @@ func (pool *LegacyPool) GetMetadata(hash common.Hash) *txpool.TxMetadata {
 	}
 }
 
-// GetBlobs is not supported by the legacy transaction pool, it is just here to
-// implement the txpool.SubPool interface.
-func (pool *LegacyPool) GetBlobs(vhashes []common.Hash) ([]*kzg4844.Blob, []*kzg4844.Proof) {
-	return nil, nil
-}
-
 // Has returns an indicator whether txpool has a transaction cached with the
 // given hash.
 func (pool *LegacyPool) Has(hash common.Hash) bool {

core/txpool/subpool.go

@@ -23,7 +23,6 @@ import (
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/core"
 	"github.com/ethereum/go-ethereum/core/types"
-	"github.com/ethereum/go-ethereum/crypto/kzg4844"
 	"github.com/ethereum/go-ethereum/event"
 	"github.com/holiman/uint256"
 )
@@ -133,11 +132,6 @@ type SubPool interface {
 	// given transaction hash.
 	GetMetadata(hash common.Hash) *TxMetadata
 
-	// GetBlobs returns a number of blobs are proofs for the given versioned hashes.
-	// This is a utility method for the engine API, enabling consensus clients to
-	// retrieve blobs from the pools directly instead of the network.
-	GetBlobs(vhashes []common.Hash) ([]*kzg4844.Blob, []*kzg4844.Proof)
-
 	// ValidateTxBasics checks whether a transaction is valid according to the consensus
 	// rules, but does not check state-dependent validation such as sufficient balance.
 	// This check is meant as a static check which can be performed without holding the

core/txpool/txpool.go

@@ -26,7 +26,6 @@ import (
 	"github.com/ethereum/go-ethereum/core"
 	"github.com/ethereum/go-ethereum/core/state"
 	"github.com/ethereum/go-ethereum/core/types"
-	"github.com/ethereum/go-ethereum/crypto/kzg4844"
 	"github.com/ethereum/go-ethereum/event"
 	"github.com/ethereum/go-ethereum/log"
 	"github.com/ethereum/go-ethereum/params"
@@ -308,22 +307,6 @@ func (p *TxPool) GetMetadata(hash common.Hash) *TxMetadata {
 	return nil
 }
 
-// GetBlobs returns a number of blobs are proofs for the given versioned hashes.
-// This is a utility method for the engine API, enabling consensus clients to
-// retrieve blobs from the pools directly instead of the network.
-func (p *TxPool) GetBlobs(vhashes []common.Hash) ([]*kzg4844.Blob, []*kzg4844.Proof) {
-	for _, subpool := range p.subpools {
-		// It's an ugly to assume that only one pool will be capable of returning
-		// anything meaningful for this call, but anythingh else requires merging
-		// partial responses and that's too annoying to do until we get a second
-		// blobpool (probably never).
-		if blobs, proofs := subpool.GetBlobs(vhashes); blobs != nil {
-			return blobs, proofs
-		}
-	}
-	return nil, nil
-}
-
 // Add enqueues a batch of transactions into the pool if they are valid. Due
 // to the large transaction churn, add may postpone fully integrating the tx
 // to a later point to batch multiple ones together.

core/txpool/validation.go

@@ -138,28 +138,7 @@ func ValidateTransaction(tx *types.Transaction, head *types.Header, signer types
 		return fmt.Errorf("%w: gas tip cap %v, minimum needed %v", ErrTxGasPriceTooLow, tx.GasTipCap(), opts.MinTip)
 	}
 	if tx.Type() == types.BlobTxType {
-		// Ensure the blob fee cap satisfies the minimum blob gas price
-		if tx.BlobGasFeeCapIntCmp(blobTxMinBlobGasPrice) < 0 {
-			return fmt.Errorf("%w: blob fee cap %v, minimum needed %v", ErrTxGasPriceTooLow, tx.BlobGasFeeCap(), blobTxMinBlobGasPrice)
-		}
-		sidecar := tx.BlobTxSidecar()
-		if sidecar == nil {
-			return errors.New("missing sidecar in blob transaction")
-		}
-		// Ensure the number of items in the blob transaction and various side
-		// data match up before doing any expensive validations
-		hashes := tx.BlobHashes()
-		if len(hashes) == 0 {
-			return errors.New("blobless blob transaction")
-		}
-		maxBlobs := eip4844.MaxBlobsPerBlock(opts.Config, head.Time)
-		if len(hashes) > maxBlobs {
-			return fmt.Errorf("too many blobs in transaction: have %d, permitted %d", len(hashes), maxBlobs)
-		}
-		// Ensure commitments, proofs and hashes are valid
-		if err := validateBlobSidecar(hashes, sidecar); err != nil {
-			return err
-		}
+		return validateBlobTx(tx, head, opts)
 	}
 	if tx.Type() == types.SetCodeTxType {
 		if len(tx.SetCodeAuthorizations()) == 0 {
@@ -169,18 +148,46 @@ func ValidateTransaction(tx *types.Transaction, head *types.Header, signer types
 	return nil
 }
 
-func validateBlobSidecar(hashes []common.Hash, sidecar *types.BlobTxSidecar) error {
+// validateBlobTx implements the blob-transaction specific validations.
+func validateBlobTx(tx *types.Transaction, head *types.Header, opts *ValidationOptions) error {
+	sidecar := tx.BlobTxSidecar()
+	if sidecar == nil {
+		return errors.New("missing sidecar in blob transaction")
+	}
+	// Ensure the blob fee cap satisfies the minimum blob gas price
+	if tx.BlobGasFeeCapIntCmp(blobTxMinBlobGasPrice) < 0 {
+		return fmt.Errorf("%w: blob fee cap %v, minimum needed %v", ErrTxGasPriceTooLow, tx.BlobGasFeeCap(), blobTxMinBlobGasPrice)
+	}
+	// Ensure the number of items in the blob transaction and various side
+	// data match up before doing any expensive validations
+	hashes := tx.BlobHashes()
+	if len(hashes) == 0 {
+		return errors.New("blobless blob transaction")
+	}
+	maxBlobs := eip4844.MaxBlobsPerBlock(opts.Config, head.Time)
+	if len(hashes) > maxBlobs {
+		return fmt.Errorf("too many blobs in transaction: have %d, permitted %d", len(hashes), maxBlobs)
+	}
 	if len(sidecar.Blobs) != len(hashes) {
 		return fmt.Errorf("invalid number of %d blobs compared to %d blob hashes", len(sidecar.Blobs), len(hashes))
 	}
-	if len(sidecar.Proofs) != len(hashes) {
-		return fmt.Errorf("invalid number of %d blob proofs compared to %d blob hashes", len(sidecar.Proofs), len(hashes))
-	}
 	if err := sidecar.ValidateBlobCommitmentHashes(hashes); err != nil {
 		return err
 	}
-	// Blob commitments match with the hashes in the transaction, verify the
-	// blobs themselves via KZG
+	// Fork-specific sidecar checks, including proof verification.
+	if opts.Config.IsOsaka(head.Number, head.Time) {
+		return validateBlobSidecarOsaka(sidecar, hashes)
+	}
+	return validateBlobSidecarLegacy(sidecar, hashes)
+}
+
+func validateBlobSidecarLegacy(sidecar *types.BlobTxSidecar, hashes []common.Hash) error {
+	if sidecar.Version != 0 {
+		return fmt.Errorf("invalid sidecar version pre-osaka: %v", sidecar.Version)
+	}
+	if len(sidecar.Proofs) != len(hashes) {
+		return fmt.Errorf("invalid number of %d blob proofs expected %d", len(sidecar.Proofs), len(hashes))
+	}
 	for i := range sidecar.Blobs {
 		if err := kzg4844.VerifyBlobProof(&sidecar.Blobs[i], sidecar.Commitments[i], sidecar.Proofs[i]); err != nil {
 			return fmt.Errorf("invalid blob %d: %v", i, err)
@@ -189,6 +196,16 @@ func validateBlobSidecar(hashes []common.Hash, sidecar *types.BlobTxSidecar) err
 	return nil
 }
 
+func validateBlobSidecarOsaka(sidecar *types.BlobTxSidecar, hashes []common.Hash) error {
+	if sidecar.Version != 1 {
+		return fmt.Errorf("invalid sidecar version post-osaka: %v", sidecar.Version)
+	}
+	if len(sidecar.Proofs) != len(hashes)*kzg4844.CellProofsPerBlob {
+		return fmt.Errorf("invalid number of %d blob proofs expected %d", len(sidecar.Proofs), len(hashes)*kzg4844.CellProofsPerBlob)
+	}
+	return kzg4844.VerifyCellProofs(sidecar.Blobs, sidecar.Commitments, sidecar.Proofs)
+}
+
 // ValidationOptionsWithState define certain differences between stateful transaction
 // validation across the different pools without having to duplicate those checks.
 type ValidationOptionsWithState struct {