0x6f00 转换 Javacard 共享接口时出错

Question

我尝试对两个不同的包使用 SIO（可共享接口对象），以便将来更新我的小程序的业务逻辑。我正在使用 eclipse，并启动两个不同的 JavaCard 应用程序：ClientSIOApplet 和 ServerSIOApplet。ClientSIOApplet 中有一个名为 appClient 的包，ServerSIOApplet 中有一个名为 appServer 的包。另外，ClientApplet.java 和 ServerAppBankInterface.java 是 appClient 中的类，而 ServerAppBankInterface.java 和 ServerApplet.java 是 appServer 中的类。您可以看到下面的源代码：

appClient 中的 ClientApplet.java

package appClient;

import javacard.framework.AID;
import javacard.framework.APDU;
import javacard.framework.Applet;
import javacard.framework.ISO7816;
import javacard.framework.ISOException;
import javacard.framework.JCSystem;
import javacard.framework.Shareable;
import javacard.framework.Util;

public class ClientApplet extends Applet {

    Shareable  sio;

    byte[] serverAID = {(byte)0x01, (byte)0x02, (byte)0x03, (byte)0x04, (byte)0x05, (byte)0x01};

    public ClientApplet() {
        // TODO Auto-generated constructor stub

    }

    public static void install(byte[] bArray, short bOffset, byte bLength) {
        // GP-compliant JavaCard applet registration
        new ClientApplet().register(bArray, (short) (bOffset + 1),
                bArray[bOffset]);       
    }

    public void process(APDU apdu) {
        // Good practice: Return 9000 on SELECT
        if (selectingApplet()) {
            return;
        }
        byte[] buf = apdu.getBuffer();      
        byte cla = buf[ISO7816.OFFSET_CLA];

        if (( cla != ISO7816.CLA_ISO7816) && (cla != (byte) 0x10))
            ISOException.throwIt(ISO7816.SW_CLA_NOT_SUPPORTED);

        switch (buf[ISO7816.OFFSET_INS]) {
        case (byte) 0x00:


             AID svrAid = JCSystem.lookupAID(serverAID, 
                                     (short)0, 
                                     (byte)serverAID.length);

            if(svrAid == null) {
                // Cannot find the serverAID AID
                ISOException.throwIt((short)0x0010);
            }

            /*sio = JCSystem.getAppletShareableInterfaceObject(svrAid, (byte)0);
            if (sio == null) ISOException.throwIt(ISO7816.SW_WRONG_LENGTH);
            if (! (sio instanceof SharedArray))
                ISOException.throwIt(ISO7816.SW_INS_NOT_SUPPORTED);
            SharedArray theSharedArray = (SharedArray) sio;
            final byte[] sa = theSharedArray.getSharedArray();*/

            //ISOException.throwIt(ISO7816.SW_COMMAND_NOT_ALLOWED);

            sio = JCSystem.getAppletShareableInterfaceObject(svrAid, (byte)0);


            if(sio == null){
                ISOException.throwIt(ISO7816.SW_WRONG_LENGTH);
            }


            /*if (! (sio instanceof ServerAppBankInterface))
                ISOException.throwIt(ISO7816.SW_FILE_INVALID);*/

            try{
                ServerAppBankInterface bankInterface = (ServerAppBankInterface) sio;
            }catch(Exception ex){
                ISOException.throwIt(ISO7816.SW_WRONG_P1P2);
            }


                        break;
        //default:
            // good practice: If you don't know the INStruction, say so:
            //ISOException.throwIt(ISO7816.SW_INS_NOT_SUPPORTED);
        }
    }

}

appClient 中的 ServerAppBankInterface.java

package appClient;

import javacard.framework.Shareable;

public interface ServerAppBankInterface extends Shareable{
    //public void saveMoneyInBank(short amount);
    public short getSavedMoneyInBank();
}

appServer 中的 ServerApplet.java

package appServer;

import javacard.framework.AID;
import javacard.framework.APDU;
import javacard.framework.Applet;
import javacard.framework.ISO7816;
import javacard.framework.ISOException;
import javacard.framework.Shareable;


public class ServerApplet extends Applet implements ServerAppBankInterface{



    public ServerApplet(byte[] bArray, short bOffset, byte bLength){

        register(bArray, (short) (bOffset + 1), bArray[bOffset]);

        /*final byte[] sa = new byte[] { 'm' };
        sharedArray = new SharedArrayImpl(sa);*/
    }

    public Shareable getShareableInterfaceObject(AID clientID, byte parameter){

        byte[] tempAID = {(byte)0x05, (byte)0x04, (byte)0x03, (byte)0x02, (byte)0x01, (byte)0x01};

        if((clientID.equals(tempAID,
                (short)0,
                (byte)tempAID.length)) == false)
            return  null;
        else
            return this;
            //return sharedArray;
            //return serverAppBankObject;
            //return (ServerAppBankInterface) this;
            //return (Shareable) this;

    }

    public boolean select()
    {
         return true;
    }

    public static void install(byte[] bArray, short bOffset, byte bLength) {
        // GP-compliant JavaCard applet registration
        new ServerApplet(bArray, bOffset, bLength);
    }

    public void process(APDU apdu) {
        // Good practice: Return 9000 on SELECT

        byte[] buf = apdu.getBuffer();
        switch (buf[ISO7816.OFFSET_INS]) {
        case (byte) 0x00:
            break;
        default:
            // good practice: If you don't know the INStruction, say so:
            ISOException.throwIt(ISO7816.SW_INS_NOT_SUPPORTED);
        }
    }

    public short getSavedMoneyInBank() {
        // TODO Auto-generated method stub
        return 0;
    }



}

appServer 中的 ServerAppBankInterface.java

package appServer;

import javacard.framework.Shareable;

public interface ServerAppBankInterface extends Shareable{
    //public void saveMoneyInBank(short amount);
    public short getSavedMoneyInBank();
}

问题是：

我在投射界面时遇到问题：

ServerAppBankInterface bankInterface = (ServerAppBankInterface) sio;

在ClientApplet.java中

如果我删除该行中的 Try-Catch，我会收到 0x6F00 错误，

Answer 1

服务器小程序提供以下类型的可共享接口

appServer.ServerApplet <- appServer.ServerAppBankInterface <- javacard.framework.Shareable

但是当您在客户端小程序中收到此可共享接口对象时，您正尝试将其转换为

appClient.ServerAppBankInterface <- javacard.framework.Shareable

虽然接口appServer.ServerAppBankInterface和appClient.ServerAppBankInterface具有相似的名称并公开具有相同名称的方法，但这两个接口既不相同也不相互继承。因此你不能在它们之间进行转换。

因此，您尝试将接收到的可共享对象实例转换为不相关的类型。因此，强制转换失败并引发（未处理的）异常。

为了解决这个问题，您需要将客户端小程序中接收到的可共享对象转换为appServer.ServerAppBankInterface.