core, eth/downloader, params: validate blob tx bodies (#27392)

core/block_validator.go

@@ -84,7 +84,23 @@ func (v *BlockValidator) ValidateBody(block *types.Block) error {
 	// Blob transactions may be present after the Cancun fork.
 	var blobs int
 	for _, tx := range block.Transactions() {
+		// Count the number of blobs to validate against the header's dataGasUsed
 		blobs += len(tx.BlobHashes())
+
+		// Validate the data blobs individually too
+		if tx.Type() == types.BlobTxType {
+			if tx.To() == nil {
+				return errors.New("contract creation attempt by blob transaction") // TODO(karalabe): Why not make the field non-nil-able
+			}
+			if len(tx.BlobHashes()) == 0 {
+				return errors.New("no-blob blob transaction present in block body")
+			}
+			for _, hash := range tx.BlobHashes() {
+				if hash[0] != params.BlobTxHashVersion {
+					return fmt.Errorf("blob hash version mismatch (have %d, supported %d)", hash[0], params.BlobTxHashVersion)
+				}
+			}
+		}
 	}
 	if header.DataGasUsed != nil {
 		if want := *header.DataGasUsed / params.BlobTxDataGasPerBlob; uint64(blobs) != want { // div because the header is surely good vs the body might be bloated