transaction: implement AddVerificationHash() method

cli/wallet/nep5.go

@@ -311,10 +311,7 @@ func transferNEP5(ctx *cli.Context) error {
 
 	gas := flags.Fixed8FromContext(ctx, "gas")
 	tx := transaction.NewInvocationTX(w.Bytes(), gas)
-	tx.Attributes = append(tx.Attributes, transaction.Attribute{
-		Usage: transaction.Script,
-		Data:  from.BytesBE(),
-	})
+	tx.AddVerificationHash(from)
 
 	if err := request.AddInputsAndUnspentsToTx(tx, fromFlag.String(), core.UtilityTokenID(), gas, c); err != nil {
 		return cli.NewExitError(fmt.Errorf("can't add GAS to a tx: %v", err), 1)

pkg/core/transaction/transaction.go

@@ -91,6 +91,14 @@ func (t *Transaction) AddInput(in *Input) {
 	t.Inputs = append(t.Inputs, *in)
 }
 
+// AddVerificationHash adds a script attribute for transaction verification.
+func (t *Transaction) AddVerificationHash(addr util.Uint160) {
+	t.Attributes = append(t.Attributes, Attribute{
+		Usage: Script,
+		Data:  addr.BytesBE(),
+	})
+}
+
 // DecodeBinary implements Serializable interface.
 func (t *Transaction) DecodeBinary(br *io.BinReader) {
 	t.Type = TXType(br.ReadB())

pkg/rpc/client/rpc.go

@@ -515,11 +515,7 @@ func (c *Client) SignAndPushInvocationTx(script []byte, acc *wallet.Account, sys
 		if err != nil {
 			return txHash, errors.Wrap(err, "failed to get address")
 		}
-		tx.Attributes = append(tx.Attributes,
-			transaction.Attribute{
-				Usage: transaction.Script,
-				Data:  addr.BytesBE(),
-			})
+		tx.AddVerificationHash(addr)
 	}
 
 	if err = acc.SignTx(tx); err != nil {

pkg/rpc/request/txBuilder.go

@@ -38,11 +38,7 @@ func CreateRawContractTransaction(params ContractTxParams) (*transaction.Transac
 	if toAddressHash, err = address.StringToUint160(toAddress); err != nil {
 		return nil, errs.Wrapf(err, "Failed to take script hash from address: %v", toAddress)
 	}
-	tx.Attributes = append(tx.Attributes,
-		transaction.Attribute{
-			Usage: transaction.Script,
-			Data:  fromAddressHash.BytesBE(),
-		})
+	tx.AddVerificationHash(fromAddressHash)
 
 	if err = AddInputsAndUnspentsToTx(tx, fromAddress, assetID, amount, balancer); err != nil {
 		return nil, errs.Wrap(err, "failed to add inputs and unspents to transaction")