SELECT APDU doesn't work fine

0
votes

I create a package(AID=0102030405) with two applets inside.

This is the program of first applet (AID=01020304050202020202) that store contents of bArray to a static filed and returns it in process method : 

package processMethodArguments;

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

public class ArgumentReturner extends Applet {
//this is my static field that I want store bArray (the install method argument) in it.
    public static byte[] theArray={(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff};
    public static short arrayLength=(short)0xFF;

    private ArgumentReturner() {
    }

    public static void install(byte bArray[], short bOffset, byte bLength)
            throws ISOException {

        new ArgumentReturner().register();

        //Storing bArray in theArray.
        ArgumentReturner.arrayLength=(short)bArray.length;
        Util.arrayCopyNonAtomic(bArray, (short)0,ArgumentReturner.theArray , (short) 0, ArgumentReturner.arrayLength);    


    }

    public void process(APDU apdu) throws ISOException {
        //returning theArray (=bArray) in response of any command.
        byte[] buffer=apdu.getBuffer();
        Util.arrayCopyNonAtomic(ArgumentReturner.theArray, (short)0,buffer , (short) 0, ArgumentReturner.arrayLength); 
        apdu.setOutgoingAndSend((short)0, (short)255);
    }

}

And this is the program of second applet (AID=010203040502) that do nothing : 

package processMethodArguments;

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

public class SecondApplet extends Applet {

    private SecondApplet() {
    }

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

    public void process(APDU arg0) throws ISOException {
        // Nothing to do. So in reception of any command, it must return only 0x9000

    }

}

I converted and installed this package on my card successfully :

GP: gp -install D:\bArrayAccessibility\processMethodArguments.cap

GP: gp -list
AID: A000000151000000 (|....Q...|)
     ISD OP_READY: Security Domain, Card lock, Card terminate, Default selected,
 CVM (PIN) management

AID: 01020304050202020202 (|..........|)
     App SELECTABLE: (none)

AID: A0000001515350 (|....QSP|)
     ExM LOADED: (none)
     A000000151535041 (|....QSPA|)

AID: 0102030405 (|.....|)
     ExM LOADED: (none)
     01020304050202020202 (|..........|)
     010203040502 (|......|)


GP: gp -create 010203040502 -package 0102030405 -applet 010203040502

GP: gp -list
AID: A000000151000000 (|....Q...|)
     ISD OP_READY: Security Domain, Card lock, Card terminate, Default selected,
 CVM (PIN) management

AID: 01020304050202020202 (|..........|)
     App SELECTABLE: (none)

AID: 010203040502 (|......|)
     App SELECTABLE: (none)

AID: A0000001515350 (|....QSP|)
     ExM LOADED: (none)
     A000000151535041 (|....QSPA|)

AID: 0102030405 (|.....|)
     ExM LOADED: (none)
     01020304050202020202 (|..........|)
     010203040502 (|......|)


GP:

Now, The problem is that: when I select first applet or second applet, both returns the APDU buffer (=theArray) : 

OpenSC: opensc-tool -s 00a404000a01020304050202020202
Using reader with a card: ACS CCID USB Reader 0
Sending: 00 A4 04 00 0A 01 02 03 04 05 02 02 02 02 02
Received (SW1=0x90, SW2=0x00):
0A 01 02 03 04 05 02 02 02 02 02 01 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00    ...............

OpenSC: opensc-tool -s 00a4040006010203040502
Using reader with a card: ACS CCID USB Reader 0
Sending: 00 A4 04 00 06 01 02 03 04 05 02
Received (SW1=0x90, SW2=0x00):
0A 01 02 03 04 05 02 02 02 02 02 01 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00    ...............

OpenSC:

Q: Why it behave in this way?

Why for both commands, the first applet seleted?

1
javajavacard

1 Answers

1
votes

AID's are hierarchical. The Java Card runtime simply chooses the first one that matches against the bytes given, even if the AID contains more bytes. It may select the second one if you fire the SELECT again.

To resolve this give the Applets AID's that are distinct even for the bytes in the shortest AID.