Java Card 客户端-服务器可共享接口(interface)返回 6F00

Question

我尝试使用 Eclipse 3.7 SDK 在 java card 2.2.2 中使用可共享接口(interface)创建一个简单的客户端和服务器小程序。当方法 JCSystem.getAppletShareableInterfaceObject 被调用时，它会抛出异常，因此返回 SW 设置为 6F00。

这是客户端应用代码(Test_Client.java):

    package client;

import server.Test_ServerInf;
import javacard.framework.AID;
import javacard.framework.APDU;
import javacard.framework.Applet;
import javacard.framework.ISO7816;
import javacard.framework.ISOException;
import javacard.framework.JCSystem;

public class Test_Client extends Applet {

    protected static final byte INS1 = (byte)0xE2;
    protected static final byte INS2 = (byte)0x21;

    byte[] ServerAIDbyte={(byte)0x20,(byte)0x21,(byte)0x22,(byte)0x23,(byte)0x24,(byte)0x25,(byte)0x26,(byte)0x27,(byte)0x01};
    AID ServerAID;

    private Test_Client() {
    }

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

    public void process(APDU apdu) throws ISOException {
        // TODO Auto-generated method stub
        byte[] apduBuffer = apdu.getBuffer();

        byte Ins=apduBuffer[ISO7816.OFFSET_INS];
        short byteread = apdu.setIncomingAndReceive();

        if (selectingApplet())
            return;

        switch (Ins){
        case INS1:
            Ins1_Handler(apdu);
            return;
        case INS2:
            Ins2_Handler(apdu,apduBuffer);
            return;
        default:
            ISOException.throwIt(ISO7816.SW_FUNC_NOT_SUPPORTED);
        }
    }
    private void Ins1_Handler(APDU apdu){
        Test_ServerInf sio = null;
        ServerAID=JCSystem.lookupAID(ServerAIDbyte,(short) 0,(byte) ServerAIDbyte.length);
        if(ServerAID==null)
            ISOException.throwIt( (short) 0x6A82);
        ////server request
        try{
        sio=(Test_ServerInf)(JCSystem.getAppletShareableInterfaceObject(ServerAID, (byte) 0));
        }
        catch(SecurityException e)
       {
           ISOException.throwIt((short)0x12);
       }
       catch(Exception e)
       {
           ISOException.throwIt((short)0x10);
       }
        if(sio==null)
            ISOException.throwIt((short)0x6A00);

    }

    private void Ins2_Handler(APDU apdu,byte[] apduBuffer){
            Test_ServerInf sio = null;
           ////connect to server  
          ServerAID=JCSystem.lookupAID(ServerAIDbyte,(short) 0,(byte) ServerAIDbyte.length);
           if(ServerAID==null)
                ISOException.throwIt( (short) 0x6A82);
           ////server request
           try{
               sio=(Test_ServerInf)(JCSystem.getAppletShareableInterfaceObject(ServerAID, (byte) 0));
           }
           catch(SecurityException e)
           {
               ISOException.throwIt((short)0x12);
           }
           catch(Exception e)
           {
               ISOException.throwIt((short)0x10);
           }
           if(sio==null)
                ISOException.throwIt((short)0x6A00); 
    }


}

这是服务器小程序代码(Test_Server.java):

  package server;

import javacard.framework.APDU;
import javacard.framework.Applet;
import javacard.framework.ISOException;
import server.Test_ServerInf;
import javacard.framework.Shareable;
import javacard.framework.AID;

public class Test_Server extends Applet implements Test_ServerInf{


    private Test_Server() {
    }

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

    public void process(APDU apdu) throws ISOException {
        // TODO Auto-generated method stub

    }

    public Shareable getShareableInterfaceObject(AID clientAID, byte parameter) {
        return this;
    }

    public short method1(){
        return (short)0x01;
    }
    public short method2(){
        return (short)0x02;
    }

}

和共享接口(interface)文件(Test_ServerInf.java):

package server;

import javacard.framework.Shareable;

public interface Test_ServerInf extends Shareable {

    public short method1();
    public short method2();

}

Answer 1

您正试图在您的客户端 applet 类的成员字段中存储对可共享接口(interface)对象的引用:

sio = (Test_ServerInf)(JCSystem.getAppletShareableInterfaceObject(ServerAID, (byte) 0));

其中 sio 被定义为 applet 类实例的私有(private)成员:

public class Test_Client extends Applet {
    private Test_ServerInf sio;

这将导致 SecurityException，因为可共享接口(interface)对象由服务器小程序拥有(即由不同的上下文拥有)。不允许在实例字段中存储其他上下文拥有的对象。

请参阅访问类实例对象字段(第 6.2.8.3 节)，运行时环境规范，Java Card 平台，版本 2.2.2:

Bytecodes: getfield, putfield

• [...] if the object is owned by an applet in the currently active context, access is allowed.
• Otherwise, access is denied.