feat(smart_wallet): add GetStubSignature method (#478)

Author: nksazonov

pkg/smart_wallet/config.go

@@ -6,6 +6,8 @@ import (
 	"github.com/ethereum/go-ethereum/common"
 )
 
+// TODO: rewrite using interface and implement it for each type
+
 // SmartWalletConfig represents the configuration
 // for the smart wallet to be used with the client.
 type Config struct {

pkg/smart_wallet/sig.go

@@ -0,0 +1,18 @@
+package smart_wallet
+
+import (
+	"fmt"
+
+	"github.com/ethereum/go-ethereum/common/hexutil"
+)
+
+func GetStubSignature(swt Type) ([]byte, error) {
+	switch swt {
+	case SimpleAccountType, BiconomyType:
+		return hexutil.Decode("0xfffffffffffffffffffffffffffffff0000000000000000000000000000000007aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa1c")
+	case KernelType:
+		return hexutil.Decode("0x00000000fffffffffffffffffffffffffffffff0000000000000000000000000000000007aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa1c")
+	default:
+		return nil, fmt.Errorf("unknown smart wallet type: %s", swt)
+	}
+}