From d62853e10393d7f28c50f1f141c4d827209e19e0 Mon Sep 17 00:00:00 2001
From: Jared Wasinger <j-wasinger@hotmail.com>
Date: Wed, 19 Feb 2025 15:37:30 -0800
Subject: [PATCH] core/txpool,core/types,eth: when receiving blob txs via
 PooledTransactions, validate that the 'blob_versioned_hashes' in the tx
 header is produced from the commitments in the sidecar.

---
 core/txpool/validation.go | 14 ++------------
 core/types/tx_blob.go     | 23 +++++++++++++++++++++++
 eth/handler_eth.go        | 11 ++++++++++-
 3 files changed, 35 insertions(+), 13 deletions(-)

diff --git a/core/txpool/validation.go b/core/txpool/validation.go
index 4d53c386b6..f9f90ab812 100644
--- a/core/txpool/validation.go
+++ b/core/txpool/validation.go
@@ -17,7 +17,6 @@
 package txpool
 
 import (
-	"crypto/sha256"
 	"errors"
 	"fmt"
 	"math/big"
@@ -170,20 +169,11 @@ func validateBlobSidecar(hashes []common.Hash, sidecar *types.BlobTxSidecar) err
 	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.Commitments) != len(hashes) {
-		return fmt.Errorf("invalid number of %d blob commitments compared to %d blob hashes", len(sidecar.Commitments), 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))
 	}
-	// Blob quantities match up, validate that the provers match with the
-	// transaction hash before getting to the cryptography
-	hasher := sha256.New()
-	for i, vhash := range hashes {
-		computed := kzg4844.CalcBlobHashV1(hasher, &sidecar.Commitments[i])
-		if vhash != computed {
-			return fmt.Errorf("blob %d: computed hash %#x mismatches transaction one %#x", i, computed, vhash)
-		}
+	if err := sidecar.ValidateBlobCommitmentHashes(hashes); err != nil {
+		return err
 	}
 	// Blob commitments match with the hashes in the transaction, verify the
 	// blobs themselves via KZG
diff --git a/core/types/tx_blob.go b/core/types/tx_blob.go
index 88251ab957..482b47da27 100644
--- a/core/types/tx_blob.go
+++ b/core/types/tx_blob.go
@@ -19,6 +19,7 @@ package types
 import (
 	"bytes"
 	"crypto/sha256"
+	"fmt"
 	"math/big"
 
 	"github.com/ethereum/go-ethereum/common"
@@ -85,6 +86,28 @@ func (sc *BlobTxSidecar) encodedSize() uint64 {
 	return rlp.ListSize(blobs) + rlp.ListSize(commitments) + rlp.ListSize(proofs)
 }
 
+func (sc *BlobTxSidecar) ValidateBlobCommitmentHashes(hashes []common.Hash) error {
+	if len(sc.Blobs) != len(hashes) {
+		return fmt.Errorf("invalid number of %d blobs compared to %d blob hashes", len(sc.Blobs), len(hashes))
+	}
+	if len(sc.Commitments) != len(hashes) {
+		return fmt.Errorf("invalid number of %d blob commitments compared to %d blob hashes", len(sc.Commitments), len(hashes))
+	}
+	if len(sc.Proofs) != len(hashes) {
+		return fmt.Errorf("invalid number of %d blob proofs compared to %d blob hashes", len(sc.Proofs), len(hashes))
+	}
+	// Blob quantities match up, validate that the provers match with the
+	// transaction hash before getting to the cryptography
+	hasher := sha256.New()
+	for i, vhash := range hashes {
+		computed := kzg4844.CalcBlobHashV1(hasher, &sc.Commitments[i])
+		if vhash != computed {
+			return fmt.Errorf("blob %d: computed hash %#x mismatches transaction one %#x", i, computed, vhash)
+		}
+	}
+	return nil
+}
+
 // blobTxWithBlobs is used for encoding of transactions when blobs are present.
 type blobTxWithBlobs struct {
 	BlobTx      *BlobTx
diff --git a/eth/handler_eth.go b/eth/handler_eth.go
index b2cd52a221..45f7c2c532 100644
--- a/eth/handler_eth.go
+++ b/eth/handler_eth.go
@@ -19,7 +19,6 @@ package eth
 import (
 	"errors"
 	"fmt"
-
 	"github.com/ethereum/go-ethereum/core"
 	"github.com/ethereum/go-ethereum/core/types"
 	"github.com/ethereum/go-ethereum/eth/protocols/eth"
@@ -69,6 +68,16 @@ func (h *ethHandler) Handle(peer *eth.Peer, packet eth.Packet) error {
 		return h.txFetcher.Enqueue(peer.ID(), *packet, false)
 
 	case *eth.PooledTransactionsResponse:
+		for _, tx := range *packet {
+			if tx.Type() == types.BlobTxType {
+				if tx.BlobTxSidecar() == nil {
+					return errors.New("received sidecar-less blob transaction")
+				}
+				if err := tx.BlobTxSidecar().ValidateBlobCommitmentHashes(tx.BlobHashes()); err != nil {
+					return err
+				}
+			}
+		}
 		return h.txFetcher.Enqueue(peer.ID(), *packet, true)
 
 	default: