Access Terminal and select applet

Question

Hi people,
I have a question about to run the aplet in a javacard. Is there any code or other useful material about getting terminal and select applet and run the methods of the apllet in a programmable manner? Thanks for your interest...
Edited by: POLAT on Mar 16, 2009 7:41 PM

Answer 1

Honestly I haven't figured out how to pass a pin when selecting the applet, however at the minute I have a way around it:
you will see in teh code below, I have hardcoded a default pin and I have a pin update method that can be called via a apdu,
NOTE this example works with the code above:
*Applet ID 41 63 63 6F 75 6E 74 41 70 70 6C
public class AccountApplet extends Applet {
     final static byte ACCOUNT_CLA = (byte)0xB0;
     final static byte VERIFY = (byte) 0x20;
     final static byte CREDIT = (byte) 0x30;
     final static byte DEBIT = (byte) 0x40;
     final static byte GET_BALANCE = (byte) 0x50;
     final static byte UPDATE_PIN = (byte) 0x60;
     final static short MAX_BALANCE = 10000;
     final static byte MAX_TRANSACTION_AMOUNT = 100;
     final static byte PIN_TRY_LIMIT =(byte)0x03;
     final static byte MAX_PIN_SIZE =(byte)0x08;
     // Applet-specific status words:
     OwnerPIN pin;
     short balance = 109; // Starting balance of decimal 109 is 6D in hex
     public static void install(byte[] bArray, short bOffset, byte bLength) {
                    new AccountApplet(bArray, (short) (bOffset + 1), bArray[bOffset]);
     private AccountApplet(byte[] bArray, short bOffset, byte bLength){
          pin = new OwnerPIN(PIN_TRY_LIMIT, MAX_PIN_SIZE);
          // bArray contains the default PIN initialization value (12345)
          bArray[0] = 01;
          bArray[1] = 02;
          bArray[2] = 03;
          bArray[3] = 04;
          bArray[4] = 05;
          bOffset = 0;
          bLength = 5;
          pin.update(bArray, bOffset, bLength);
          register();
     public boolean select() {
     if (pin.getTriesRemaining() == 0)
               return false;
          return true;
public void deselect() {
     pin.reset();
     public void process(APDU apdu) {
byte[] buffer = apdu.getBuffer();
          if (selectingApplet())
               return;
          if (buffer[ISO7816.OFFSET_CLA] != ACCOUNT_CLA)
               ISOException.throwIt(ISO7816.SW_CLA_NOT_SUPPORTED);
          switch (buffer[ISO7816.OFFSET_INS]) {
          case GET_BALANCE:          getBalance(apdu);      return;
          case DEBIT:                    debit(apdu);             return;
          case CREDIT:               credit(apdu);           return;
          case VERIFY:               verify(apdu);          return;
          case UPDATE_PIN:          updatePin(apdu);     return;
          default:                    ISOException.throwIt
          (ISO7816.SW_INS_NOT_SUPPORTED);
private void credit(APDU apdu) {
          if (!pin.isValidated())
               ISOException.throwIt(SW_PIN_VERIFICATION_REQUIRED);
          byte[] buffer = apdu.getBuffer();
     byte numBytes = buffer[ISO7816.OFFSET_LC];
          byte byteRead = (byte)(apdu.setIncomingAndReceive());
          if (( numBytes != 1 ) || (byteRead != 1))
               ISOException.throwIt(ISO7816.SW_WRONG_LENGTH);
          byte creditAmount = buffer[ISO7816.OFFSET_CDATA];
          if (( creditAmount > MAX_TRANSACTION_AMOUNT)
                    || ( creditAmount < 0 ))
               ISOException.throwIt(SW_INVALID_TRANSACTION_AMOUNT);
          if ((short)( balance + creditAmount)  > MAX_BALANCE)
               ISOException.throwIt(SW_EXCEED_MAXIMUM_BALANCE);
          balance = (short)(balance + creditAmount);
          return;
     private void updatePin(APDU apdu) {
          if (! pin.isValidated())
               ISOException.throwIt(SW_PIN_VERIFICATION_REQUIRED);
          byte[] buffer = apdu.getBuffer();
          byte numBytes = buffer[ISO7816.OFFSET_LC];
          byte byteRead = (byte)(apdu.setIncomingAndReceive());
               if (byteRead != numBytes) {
               ISOException.throwIt(ISO7816.SW_WRONG_LENGTH);
               if ( numBytes > 8 )
               ISOException.throwIt(SW_PIN_TO_LONG);
          if ( numBytes < 4 )
               ISOException.throwIt(SW_PIN_TO_SHORT);     
          short offset_cdata = 05;          
          pin.update(buffer, offset_cdata, numBytes);
          pin.resetAndUnblock();
     private void debit(APDU apdu) {
          if (! pin.isValidated())
               ISOException.throwIt(SW_PIN_VERIFICATION_REQUIRED);
          byte[] buffer = apdu.getBuffer();
          byte numBytes = (byte)(buffer[ISO7816.OFFSET_LC]);
     byte byteRead = (byte)(apdu.setIncomingAndReceive());
          if (( numBytes != 1 ) || (byteRead != 1))
               ISOException.throwIt(ISO7816.SW_WRONG_LENGTH);
     byte debitAmount = buffer[ISO7816.OFFSET_CDATA];
          if (( debitAmount > MAX_TRANSACTION_AMOUNT)
                    ||  ( debitAmount < 0 ))
               ISOException.throwIt(SW_INVALID_TRANSACTION_AMOUNT);
          if ((short)( balance - debitAmount ) < (short)0)
               ISOException.throwIt(SW_NEGATIVE_BALANCE);
          balance = (short) (balance - debitAmount);
     }      private void getBalance(APDU apdu) {
          byte[] buffer = apdu.getBuffer();
          short le = apdu.setOutgoing();
          apdu.setOutgoingLength((byte)2);
     Util.setShort(buffer, (short)0, balance);
          apdu.sendBytes((short)0, (short)2);
      * verification method to verify the PIN
     private void verify(APDU apdu) {
          byte[] buffer = apdu.getBuffer();
          byte byteRead = (byte)(apdu.setIncomingAndReceive());
          if (pin.check(buffer, ISO7816.OFFSET_CDATA,byteRead)
                    == false)
               ISOException.throwIt(SW_VERIFICATION_FAILED);
     } // end of verify method
} // end of class Account