为什么我收不到 APDU 缓冲区的内容？

Question

我写了下面的程序return接收到每个 APDU 命令时的所有 APDU 缓冲区内容：

package testPack;

import javacard.framework.APDU;
import javacard.framework.Applet;
import javacard.framework.ISOException;

public class BufferReturner extends Applet {

    private BufferReturner() {
    }

    public static void install(byte bArray[], short bOffset, byte bLength) throws ISOException {
        new BufferReturner().register();
    }

    public void process(APDU arg0) throws ISOException {
        if(selectingApplet()){
            return;
        }
        arg0.setOutgoingAndSend((short)0, (short)255);

    }

}

当我使用 T=0 协议通过接触界面发送命令时，我收到以下结果：

Connect successful.
Send: 00 A4 04 00 06 01 02 03 04 05 00 00
Recv: 90 00
Time used: 8.000 ms
Send: 00 00 00 00 10 11 11 11 11 11 11 11 11 11 11 11 11 11 11 11 11 00
Send Apdu error: A device attached to the system is not functioning.
Send: 00 00 00 00 10 11 11 11 11 11 11 11 11 11 11 11 11 11 11 11 11 00
Recv: 6C FF
Time used: 5.000 ms
Send: 00 00 00 00 10 11 11 11 11 11 11 11 11 11 11 11 11 11 11 11 11 FF
Recv: 6C FF
Time used: 5.000 ms
Send: 00 00 00 00 10 11 11 11 11 11 11 11 11 11 11 11 11 11 11 11 11 FF
Recv: 6C FF
Time used: 5.000 ms
Send: 00 00 00 00 10 11 11 11 11 11 11 11 11 11 11 11 11 11 11 11 11 FF
Recv: 6C FF
Time used: 6.000 ms
Send: 00 C0 00 00 FF
Send Apdu error: A device attached to the system is not functioning.
Send: 00 C0 00 00 FF
Send Apdu error: A device attached to the system is not functioning.

如您所见，我无法接收 APDU 缓冲区内容。怎么了？

Answer 1

就像一样，您的卡没有任何问题，这是 "expected" 的行为。

对于setOutgoing()方法（setOutgoingAndSend()只是包装setOutgoing()的一种便捷方法），Java卡API规范明确指出：

On a case 4 command, the setIncomingAndReceive() must be invoked prior to calling this method. Otherwise, erroneous behavior may result in T=0 protocol.

因此，您看到的正是 API 规范中指出的“错误行为”。

为什么我收不到 APDU 缓冲区的内容？

Why I can't receive APDU buffer contents?

apdu

smartcard

javacard

contactless-smartcard