work around GET DATA transmission over T=1

apdu/command.go

@@ -18,7 +18,6 @@ type Command struct {
 	Data       []byte
 	le         uint8
 	requiresLe bool
-	requiresLc bool
 }
 
 // NewCommand returns a new apdu Command.
@@ -30,7 +29,6 @@ func NewCommand(cla, ins, p1, p2 uint8, data []byte) *Command {
 		P2:         p2,
 		Data:       data,
 		requiresLe: false,
-		requiresLc: false,
 	}
 }
 
@@ -40,10 +38,6 @@ func (c *Command) SetLe(le uint8) {
 	c.le = le
 }
 
-func (c *Command) RequiresLc() {
-	c.requiresLc = true
-}
-
 // Le returns if Le is set and its value.
 func (c *Command) Le() (bool, uint8) {
 	return c.requiresLe, c.le
@@ -69,7 +63,7 @@ func (c *Command) Serialize() ([]byte, error) {
 		return nil, err
 	}
 
-	if (len(c.Data) > 0) || c.requiresLc {
+	if len(c.Data) > 0 {
 		if err := binary.Write(buf, binary.BigEndian, uint8(len(c.Data))); err != nil {
 			return nil, err
 		}

commands.go

@@ -340,18 +340,13 @@ func NewCommandSign(data []byte, p1 uint8, pathStr string) (*apdu.Command, error
 }
 
 func NewCommandGetData(typ uint8) *apdu.Command {
-	cmd := apdu.NewCommand(
+	return apdu.NewCommand(
 		globalplatform.ClaGp,
 		InsGetData,
 		typ,
 		0,
-		[]byte{},
+		[]byte{0xCA},
 	)
-
-	cmd.SetLe(0)
-	cmd.RequiresLc()
-
-	return cmd
 }
 
 func NewCommandStoreData(typ uint8, data []byte) *apdu.Command {