signer: implement blob txs sendtxargs, enable blobtx-signing (#28976)

This change makes it possible to sign blob transactions

accounts/external/backend.go

@@ -205,7 +205,7 @@ func (api *ExternalSigner) SignTx(account accounts.Account, tx *types.Transactio
 		to = &t
 	}
 	args := &apitypes.SendTxArgs{
-		Data:  &data,
+		Input: &data,
 		Nonce: hexutil.Uint64(tx.Nonce()),
 		Value: hexutil.Big(*tx.Value()),
 		Gas:   hexutil.Uint64(tx.Gas()),
@@ -215,7 +215,7 @@ func (api *ExternalSigner) SignTx(account accounts.Account, tx *types.Transactio
 	switch tx.Type() {
 	case types.LegacyTxType, types.AccessListTxType:
 		args.GasPrice = (*hexutil.Big)(tx.GasPrice())
-	case types.DynamicFeeTxType:
+	case types.DynamicFeeTxType, types.BlobTxType:
 		args.MaxFeePerGas = (*hexutil.Big)(tx.GasFeeCap())
 		args.MaxPriorityFeePerGas = (*hexutil.Big)(tx.GasTipCap())
 	default:
@@ -235,6 +235,17 @@ func (api *ExternalSigner) SignTx(account accounts.Account, tx *types.Transactio
 		accessList := tx.AccessList()
 		args.AccessList = &accessList
 	}
+	if tx.Type() == types.BlobTxType {
+		args.BlobHashes = tx.BlobHashes()
+		sidecar := tx.BlobTxSidecar()
+		if sidecar == nil {
+			return nil, fmt.Errorf("blobs must be present for signing")
+		}
+		args.Blobs = sidecar.Blobs
+		args.Commitments = sidecar.Commitments
+		args.Proofs = sidecar.Proofs
+	}
+
 	var res signTransactionResult
 	if err := api.client.Call(&res, "account_signTransaction", args); err != nil {
 		return nil, err

core/types/transaction.go

@@ -446,6 +446,26 @@ func (tx *Transaction) WithoutBlobTxSidecar() *Transaction {
 	return cpy
 }
 
+// WithBlobTxSidecar returns a copy of tx with the blob sidecar added.
+func (tx *Transaction) WithBlobTxSidecar(sideCar *BlobTxSidecar) *Transaction {
+	blobtx, ok := tx.inner.(*BlobTx)
+	if !ok {
+		return tx
+	}
+	cpy := &Transaction{
+		inner: blobtx.withSidecar(sideCar),
+		time:  tx.time,
+	}
+	// Note: tx.size cache not carried over because the sidecar is included in size!
+	if h := tx.hash.Load(); h != nil {
+		cpy.hash.Store(h)
+	}
+	if f := tx.from.Load(); f != nil {
+		cpy.from.Store(f)
+	}
+	return cpy
+}
+
 // SetTime sets the decoding time of a transaction. This is used by tests to set
 // arbitrary times and by persistent transaction pools when loading old txs from
 // disk.

core/types/tx_blob.go

@@ -191,6 +191,12 @@ func (tx *BlobTx) withoutSidecar() *BlobTx {
 	return &cpy
 }
 
+func (tx *BlobTx) withSidecar(sideCar *BlobTxSidecar) *BlobTx {
+	cpy := *tx
+	cpy.Sidecar = sideCar
+	return &cpy
+}
+
 func (tx *BlobTx) encode(b *bytes.Buffer) error {
 	if tx.Sidecar == nil {
 		return rlp.Encode(b, tx)

internal/ethapi/api.go

@@ -1865,15 +1865,14 @@ type SignTransactionResult struct {
 // The node needs to have the private key of the account corresponding with
 // the given from address and it needs to be unlocked.
 func (s *TransactionAPI) SignTransaction(ctx context.Context, args TransactionArgs) (*SignTransactionResult, error) {
+	args.blobSidecarAllowed = true
+
 	if args.Gas == nil {
 		return nil, errors.New("gas not specified")
 	}
 	if args.GasPrice == nil && (args.MaxPriorityFeePerGas == nil || args.MaxFeePerGas == nil) {
 		return nil, errors.New("missing gasPrice or maxFeePerGas/maxPriorityFeePerGas")
 	}
-	if args.IsEIP4844() {
-		return nil, errBlobTxNotSupported
-	}
 	if args.Nonce == nil {
 		return nil, errors.New("nonce not specified")
 	}
@@ -1889,6 +1888,16 @@ func (s *TransactionAPI) SignTransaction(ctx context.Context, args TransactionAr
 	if err != nil {
 		return nil, err
 	}
+	// If the transaction-to-sign was a blob transaction, then the signed one
+	// no longer retains the blobs, only the blob hashes. In this step, we need
+	// to put back the blob(s).
+	if args.IsEIP4844() {
+		signed = signed.WithBlobTxSidecar(&types.BlobTxSidecar{
+			Blobs:       args.Blobs,
+			Commitments: args.Commitments,
+			Proofs:      args.Proofs,
+		})
+	}
 	data, err := signed.MarshalBinary()
 	if err != nil {
 		return nil, err

internal/ethapi/api_test.go

@@ -1037,11 +1037,8 @@ func TestSignBlobTransaction(t *testing.T) {
 	}
 
 	_, err = api.SignTransaction(context.Background(), argsFromTransaction(res.Tx, b.acc.Address))
-	if err == nil {
+	if err != nil {
-		t.Fatalf("should fail on blob transaction")
+		t.Fatalf("should not fail on blob transaction")
-	}
-	if !errors.Is(err, errBlobTxNotSupported) {
-		t.Errorf("error mismatch. Have: %v, want: %v", err, errBlobTxNotSupported)
 	}
 }
 

internal/ethapi/transaction_args.go

@@ -97,7 +97,7 @@ func (args *TransactionArgs) data() []byte {
 
 // setDefaults fills in default values for unspecified tx fields.
 func (args *TransactionArgs) setDefaults(ctx context.Context, b Backend, skipGasEstimation bool) error {
-	if err := args.setBlobTxSidecar(ctx, b); err != nil {
+	if err := args.setBlobTxSidecar(ctx); err != nil {
 		return err
 	}
 	if err := args.setFeeDefaults(ctx, b); err != nil {
@@ -290,7 +290,7 @@ func (args *TransactionArgs) setLondonFeeDefaults(ctx context.Context, head *typ
 }
 
 // setBlobTxSidecar adds the blob tx
-func (args *TransactionArgs) setBlobTxSidecar(ctx context.Context, b Backend) error {
+func (args *TransactionArgs) setBlobTxSidecar(ctx context.Context) error {
 	// No blobs, we're done.
 	if args.Blobs == nil {
 		return nil

signer/core/api.go

@@ -590,7 +590,10 @@ func (api *SignerAPI) SignTransaction(ctx context.Context, args apitypes.SendTxA
 		return nil, err
 	}
 	// Convert fields into a real transaction
-	var unsignedTx = result.Transaction.ToTransaction()
+	unsignedTx, err := result.Transaction.ToTransaction()
+	if err != nil {
+		return nil, err
+	}
 	// Get the password for the transaction
 	pw, err := api.lookupOrQueryPassword(acc.Address, "Account password",
 		fmt.Sprintf("Please enter the password for account %s", acc.Address.String()))

signer/core/apitypes/types.go

@@ -18,6 +18,7 @@ package apitypes
 
 import (
 	"bytes"
+	"crypto/sha256"
 	"encoding/json"
 	"errors"
 	"fmt"
@@ -34,6 +35,8 @@ import (
 	"github.com/ethereum/go-ethereum/common/math"
 	"github.com/ethereum/go-ethereum/core/types"
 	"github.com/ethereum/go-ethereum/crypto"
+	"github.com/ethereum/go-ethereum/crypto/kzg4844"
+	"github.com/holiman/uint256"
 )
 
 var typedDataReferenceTypeRegexp = regexp.MustCompile(`^[A-Za-z](\w*)(\[\])?$`)
@@ -92,12 +95,21 @@ type SendTxArgs struct {
 	// We accept "data" and "input" for backwards-compatibility reasons.
 	// "input" is the newer name and should be preferred by clients.
 	// Issue detail: https://github.com/ethereum/go-ethereum/issues/15628
-	Data  *hexutil.Bytes `json:"data"`
+	Data  *hexutil.Bytes `json:"data,omitempty"`
 	Input *hexutil.Bytes `json:"input,omitempty"`
 
 	// For non-legacy transactions
 	AccessList *types.AccessList `json:"accessList,omitempty"`
 	ChainID    *hexutil.Big      `json:"chainId,omitempty"`
+
+	// For BlobTxType
+	BlobFeeCap *hexutil.Big  `json:"maxFeePerBlobGas,omitempty"`
+	BlobHashes []common.Hash `json:"blobVersionedHashes,omitempty"`
+
+	// For BlobTxType transactions with blob sidecar
+	Blobs       []kzg4844.Blob       `json:"blobs,omitempty"`
+	Commitments []kzg4844.Commitment `json:"commitments,omitempty"`
+	Proofs      []kzg4844.Proof      `json:"proofs,omitempty"`
 }
 
 func (args SendTxArgs) String() string {
@@ -108,24 +120,56 @@ func (args SendTxArgs) String() string {
 	return err.Error()
 }
 
+// data retrieves the transaction calldata. Input field is preferred.
+func (args *SendTxArgs) data() []byte {
+	if args.Input != nil {
+		return *args.Input
+	}
+	if args.Data != nil {
+		return *args.Data
+	}
+	return nil
+}
+
 // ToTransaction converts the arguments to a transaction.
-func (args *SendTxArgs) ToTransaction() *types.Transaction {
+func (args *SendTxArgs) ToTransaction() (*types.Transaction, error) {
 	// Add the To-field, if specified
 	var to *common.Address
 	if args.To != nil {
 		dstAddr := args.To.Address()
 		to = &dstAddr
 	}
-
+	if err := args.validateTxSidecar(); err != nil {
-	var input []byte
+		return nil, err
-	if args.Input != nil {
-		input = *args.Input
-	} else if args.Data != nil {
-		input = *args.Data
 	}
-
 	var data types.TxData
 	switch {
+	case args.BlobHashes != nil:
+		al := types.AccessList{}
+		if args.AccessList != nil {
+			al = *args.AccessList
+		}
+		data = &types.BlobTx{
+			To:         *to,
+			ChainID:    uint256.MustFromBig((*big.Int)(args.ChainID)),
+			Nonce:      uint64(args.Nonce),
+			Gas:        uint64(args.Gas),
+			GasFeeCap:  uint256.MustFromBig((*big.Int)(args.MaxFeePerGas)),
+			GasTipCap:  uint256.MustFromBig((*big.Int)(args.MaxPriorityFeePerGas)),
+			Value:      uint256.MustFromBig((*big.Int)(&args.Value)),
+			Data:       args.data(),
+			AccessList: al,
+			BlobHashes: args.BlobHashes,
+			BlobFeeCap: uint256.MustFromBig((*big.Int)(args.BlobFeeCap)),
+		}
+		if args.Blobs != nil {
+			data.(*types.BlobTx).Sidecar = &types.BlobTxSidecar{
+				Blobs:       args.Blobs,
+				Commitments: args.Commitments,
+				Proofs:      args.Proofs,
+			}
+		}
+
 	case args.MaxFeePerGas != nil:
 		al := types.AccessList{}
 		if args.AccessList != nil {
@@ -139,7 +183,7 @@ func (args *SendTxArgs) ToTransaction() *types.Transaction {
 			GasFeeCap:  (*big.Int)(args.MaxFeePerGas),
 			GasTipCap:  (*big.Int)(args.MaxPriorityFeePerGas),
 			Value:      (*big.Int)(&args.Value),
-			Data:       input,
+			Data:       args.data(),
 			AccessList: al,
 		}
 	case args.AccessList != nil:
@@ -150,7 +194,7 @@ func (args *SendTxArgs) ToTransaction() *types.Transaction {
 			Gas:        uint64(args.Gas),
 			GasPrice:   (*big.Int)(args.GasPrice),
 			Value:      (*big.Int)(&args.Value),
-			Data:       input,
+			Data:       args.data(),
 			AccessList: *args.AccessList,
 		}
 	default:
@@ -160,10 +204,81 @@ func (args *SendTxArgs) ToTransaction() *types.Transaction {
 			Gas:      uint64(args.Gas),
 			GasPrice: (*big.Int)(args.GasPrice),
 			Value:    (*big.Int)(&args.Value),
-			Data:     input,
+			Data:     args.data(),
 		}
 	}
-	return types.NewTx(data)
+
+	return types.NewTx(data), nil
+}
+
+// validateTxSidecar validates blob data, if present
+func (args *SendTxArgs) validateTxSidecar() error {
+	// No blobs, we're done.
+	if args.Blobs == nil {
+		return nil
+	}
+
+	n := len(args.Blobs)
+	// Assume user provides either only blobs (w/o hashes), or
+	// blobs together with commitments and proofs.
+	if args.Commitments == nil && args.Proofs != nil {
+		return errors.New(`blob proofs provided while commitments were not`)
+	} else if args.Commitments != nil && args.Proofs == nil {
+		return errors.New(`blob commitments provided while proofs were not`)
+	}
+
+	// len(blobs) == len(commitments) == len(proofs) == len(hashes)
+	if args.Commitments != nil && len(args.Commitments) != n {
+		return fmt.Errorf("number of blobs and commitments mismatch (have=%d, want=%d)", len(args.Commitments), n)
+	}
+	if args.Proofs != nil && len(args.Proofs) != n {
+		return fmt.Errorf("number of blobs and proofs mismatch (have=%d, want=%d)", len(args.Proofs), n)
+	}
+	if args.BlobHashes != nil && len(args.BlobHashes) != n {
+		return fmt.Errorf("number of blobs and hashes mismatch (have=%d, want=%d)", len(args.BlobHashes), n)
+	}
+
+	if args.Commitments == nil {
+		// Generate commitment and proof.
+		commitments := make([]kzg4844.Commitment, n)
+		proofs := make([]kzg4844.Proof, n)
+		for i, b := range args.Blobs {
+			c, err := kzg4844.BlobToCommitment(b)
+			if err != nil {
+				return fmt.Errorf("blobs[%d]: error computing commitment: %v", i, err)
+			}
+			commitments[i] = c
+			p, err := kzg4844.ComputeBlobProof(b, c)
+			if err != nil {
+				return fmt.Errorf("blobs[%d]: error computing proof: %v", i, err)
+			}
+			proofs[i] = p
+		}
+		args.Commitments = commitments
+		args.Proofs = proofs
+	} else {
+		for i, b := range args.Blobs {
+			if err := kzg4844.VerifyBlobProof(b, args.Commitments[i], args.Proofs[i]); err != nil {
+				return fmt.Errorf("failed to verify blob proof: %v", err)
+			}
+		}
+	}
+
+	hashes := make([]common.Hash, n)
+	hasher := sha256.New()
+	for i, c := range args.Commitments {
+		hashes[i] = kzg4844.CalcBlobHashV1(hasher, &c)
+	}
+	if args.BlobHashes != nil {
+		for i, h := range hashes {
+			if h != args.BlobHashes[i] {
+				return fmt.Errorf("blob hash verification failed (have=%s, want=%s)", args.BlobHashes[i], h)
+			}
+		}
+	} else {
+		args.BlobHashes = hashes
+	}
+	return nil
 }
 
 type SigFormat struct {

signer/core/apitypes/types_test.go

@@ -16,7 +16,16 @@
 
 package apitypes
 
-import "testing"
+import (
+	"crypto/sha256"
+	"encoding/json"
+	"testing"
+
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/core/types"
+	"github.com/ethereum/go-ethereum/crypto/kzg4844"
+	"github.com/holiman/uint256"
+)
 
 func TestIsPrimitive(t *testing.T) {
 	t.Parallel()
@@ -39,3 +48,96 @@ func TestIsPrimitive(t *testing.T) {
 		}
 	}
 }
+
+func TestTxArgs(t *testing.T) {
+	for i, tc := range []struct {
+		data     []byte
+		want     common.Hash
+		wantType uint8
+	}{
+		{
+			data:     []byte(`{"from":"0x1b442286e32ddcaa6e2570ce9ed85f4b4fc87425","accessList":[],"blobVersionedHashes":["0x010657f37554c781402a22917dee2f75def7ab966d7b770905398eba3c444014"],"chainId":"0x7","gas":"0x124f8","gasPrice":"0x693d4ca8","input":"0x","maxFeePerBlobGas":"0x3b9aca00","maxFeePerGas":"0x6fc23ac00","maxPriorityFeePerGas":"0x3b9aca00","nonce":"0x0","r":"0x2a922afc784d07e98012da29f2f37cae1f73eda78aa8805d3df6ee5dbb41ec1","s":"0x4f1f75ae6bcdf4970b4f305da1a15d8c5ddb21f555444beab77c9af2baab14","to":"0x1b442286e32ddcaa6e2570ce9ed85f4b4fc87425","type":"0x1","v":"0x0","value":"0x0","yParity":"0x0"}`),
+			want:     common.HexToHash("0x7d53234acc11ac5b5948632c901a944694e228795782f511887d36fd76ff15c4"),
+			wantType: types.BlobTxType,
+		},
+		{
+			// on input, we don't read the type, but infer the type from the arguments present
+			data:     []byte(`{"from":"0x1b442286e32ddcaa6e2570ce9ed85f4b4fc87425","accessList":[],"chainId":"0x7","gas":"0x124f8","gasPrice":"0x693d4ca8","input":"0x","maxFeePerBlobGas":"0x3b9aca00","maxFeePerGas":"0x6fc23ac00","maxPriorityFeePerGas":"0x3b9aca00","nonce":"0x0","r":"0x2a922afc784d07e98012da29f2f37cae1f73eda78aa8805d3df6ee5dbb41ec1","s":"0x4f1f75ae6bcdf4970b4f305da1a15d8c5ddb21f555444beab77c9af2baab14","to":"0x1b442286e32ddcaa6e2570ce9ed85f4b4fc87425","type":"0x12","v":"0x0","value":"0x0","yParity":"0x0"}`),
+			want:     common.HexToHash("0x7919e2b0b9b543cb87a137b6ff66491ec7ae937cb88d3c29db4d9b28073dce53"),
+			wantType: types.DynamicFeeTxType,
+		},
+	} {
+		var txArgs SendTxArgs
+		if err := json.Unmarshal(tc.data, &txArgs); err != nil {
+			t.Fatal(err)
+		}
+		tx, err := txArgs.ToTransaction()
+		if err != nil {
+			t.Fatal(err)
+		}
+		if have := tx.Type(); have != tc.wantType {
+			t.Errorf("test %d, have type %d, want type %d", i, have, tc.wantType)
+		}
+		if have := tx.Hash(); have != tc.want {
+			t.Errorf("test %d: have %v, want %v", i, have, tc.want)
+		}
+		d2, err := json.Marshal(txArgs)
+		if err != nil {
+			t.Fatal(err)
+		}
+		var txArgs2 SendTxArgs
+		if err := json.Unmarshal(d2, &txArgs2); err != nil {
+			t.Fatal(err)
+		}
+		tx1, _ := txArgs.ToTransaction()
+		tx2, _ := txArgs2.ToTransaction()
+		if have, want := tx1.Hash(), tx2.Hash(); have != want {
+			t.Errorf("test %d: have %v, want %v", i, have, want)
+		}
+	}
+	/*
+		End to end testing:
+
+			$ go run ./cmd/clef --advanced --suppress-bootwarn
+
+			$ go run ./cmd/geth --nodiscover --maxpeers 0 --signer /home/user/.clef/clef.ipc console
+
+				> tx={"from":"0x1b442286e32ddcaa6e2570ce9ed85f4b4fc87425","to":"0x1b442286e32ddcaa6e2570ce9ed85f4b4fc87425","gas":"0x124f8","maxFeePerGas":"0x6fc23ac00","maxPriorityFeePerGas":"0x3b9aca00","value":"0x0","nonce":"0x0","input":"0x","accessList":[],"maxFeePerBlobGas":"0x3b9aca00","blobVersionedHashes":["0x010657f37554c781402a22917dee2f75def7ab966d7b770905398eba3c444014"]}
+				> eth.signTransaction(tx)
+	*/
+}
+
+func TestBlobTxs(t *testing.T) {
+	blob := kzg4844.Blob{0x1}
+	commitment, err := kzg4844.BlobToCommitment(blob)
+	if err != nil {
+		t.Fatal(err)
+	}
+	proof, err := kzg4844.ComputeBlobProof(blob, commitment)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	hash := kzg4844.CalcBlobHashV1(sha256.New(), &commitment)
+	b := &types.BlobTx{
+		ChainID:    uint256.NewInt(6),
+		Nonce:      8,
+		GasTipCap:  uint256.NewInt(500),
+		GasFeeCap:  uint256.NewInt(600),
+		Gas:        21000,
+		BlobFeeCap: uint256.NewInt(700),
+		BlobHashes: []common.Hash{hash},
+		Value:      uint256.NewInt(100),
+		Sidecar: &types.BlobTxSidecar{
+			Blobs:       []kzg4844.Blob{blob},
+			Commitments: []kzg4844.Commitment{commitment},
+			Proofs:      []kzg4844.Proof{proof},
+		},
+	}
+	tx := types.NewTx(b)
+	data, err := json.Marshal(tx)
+	if err != nil {
+		t.Fatal(err)
+	}
+	t.Logf("tx %v", string(data))
+}

signer/core/cliui.go

@@ -128,7 +128,7 @@ func (ui *CommandlineUI) ApproveTx(request *SignTxRequest) (SignTxResponse, erro
 		fmt.Printf("chainid:  %v\n", chainId)
 	}
 	if list := request.Transaction.AccessList; list != nil {
-		fmt.Printf("Accesslist\n")
+		fmt.Printf("Accesslist:\n")
 		for i, el := range *list {
 			fmt.Printf(" %d. %v\n", i, el.Address)
 			for j, slot := range el.StorageKeys {
@@ -136,6 +136,12 @@ func (ui *CommandlineUI) ApproveTx(request *SignTxRequest) (SignTxResponse, erro
 			}
 		}
 	}
+	if len(request.Transaction.BlobHashes) > 0 {
+		fmt.Printf("Blob hashes:\n")
+		for _, bh := range request.Transaction.BlobHashes {
+			fmt.Printf("   %v\n", bh)
+		}
+	}
 	if request.Transaction.Data != nil {
 		d := *request.Transaction.Data
 		if len(d) > 0 {

signer/fourbyte/validation.go

@@ -36,6 +36,11 @@ func (db *Database) ValidateTransaction(selector *string, tx *apitypes.SendTxArg
 	if tx.Data != nil && tx.Input != nil && !bytes.Equal(*tx.Data, *tx.Input) {
 		return nil, errors.New(`ambiguous request: both "data" and "input" are set and are not identical`)
 	}
+	// ToTransaction validates, among other things, that blob hashes match with blobs, and also
+	// populates the hashes if they were previously unset.
+	if _, err := tx.ToTransaction(); err != nil {
+		return nil, err
+	}
 	// Place data on 'data', and nil 'input'
 	var data []byte
 	if tx.Input != nil {