Ppse2Pay.java

package com.st;
import javacard.framework.APDU;
import javacard.framework.Applet;
import javacard.framework.ISO7816;
import javacard.framework.ISOException;
import javacard.framework.Util;


public class Ppse2Pay extends Applet {

    private static final long serialVersionUID = 1L;

    //FCI_TEMPLATE - DEFAULT
    private byte[] ADF = {(byte)0xA0,(byte)0x00,(byte)0x00,(byte)0x00,  //Visa
            (byte)0x03,(byte)0x10,(byte)0x10			};

    //DF - Dedicated File (AID) - '2PAY.SYS.DDF01'
    public final byte[] DF = {
            (byte) 0x32, (byte) 0x50, (byte) 0x41, (byte) 0x59,
            (byte) 0x2E, (byte) 0x53, (byte) 0x59, (byte) 0x53,
            (byte) 0x2E, (byte) 0x44, (byte) 0x44, (byte) 0x46,
            (byte) 0x30, (byte) 0x31
    };

    public byte[] FCI_TEMPLATE = null;


    public Ppse2Pay(byte[] bArray, short bOffset, byte bLength) {
        if (bLength > 0) {
            ADF = new byte[bLength];
        }
        Util.arrayCopyNonAtomic(bArray, bOffset, ADF, (short)0, bLength);
    }

    public static void install(byte[] bArray, short bOffset, byte bLength) {
        new Ppse2Pay(bArray, bOffset, bLength).register(bArray, bOffset, bLength);
    }

    @Override
    public void process(APDU apdu) throws ISOException {
        byte[] buf = apdu.getBuffer();

        if (selectingApplet()) {
            //check that LC is 0x0E
            if((short)(buf[ISO7816.OFFSET_LC] & 0xFF) != 0x0E)
                ISOException.throwIt(ISO7816.SW_WRONG_LENGTH);

            //get the rest of the apdu and check length
            if((short)(buf[ISO7816.OFFSET_LC] & 0xFF) != apdu.setIncomingAndReceive())
                ISOException.throwIt(ISO7816.SW_WRONG_LENGTH);

            if(FCI_TEMPLATE==null)
            {
                FCI_TEMPLATE = new byte[12 + ADF.length];
                FCI_TEMPLATE[0]=(byte)0xA5; //FCI Proprietary Template
                FCI_TEMPLATE[1]=(byte)(10 + ADF.length);   //length
                FCI_TEMPLATE[2]=(byte)0xBF; //FCI Issuer Discretionary Data
                FCI_TEMPLATE[3]=(byte)0x0C;
                FCI_TEMPLATE[4]=(byte)(7 + ADF.length);   //length

                FCI_TEMPLATE[5]=(byte)0x61; //Directory Entry
                FCI_TEMPLATE[6]=(byte)(ADF.length + 5);   //length
                FCI_TEMPLATE[7]=(byte)0x4F; //ADF Name
                FCI_TEMPLATE[8]=(byte)(ADF.length);    //length
                for(short i=0;i<ADF.length;i++)
                    FCI_TEMPLATE[9+i] = ADF[i];
                FCI_TEMPLATE[9 + ADF.length]=(byte)0x87; //Application Priority Indicator
                FCI_TEMPLATE[10 + ADF.length]=(byte)1;    //length
                FCI_TEMPLATE[11 + ADF.length]=(byte)0x01;
            }

            //return FCI upon successful select
            apdu.setOutgoing();

            buf[0]=(byte)0x6F; //FCI Template
            buf[1]=(byte)(2 + DF.length + FCI_TEMPLATE.length);   //length
            buf[2]=(byte)0x84; //DF Name
            buf[3]=(byte)DF.length;   //length
            for(short i=0;i<DF.length;i++)
                buf[4+i] = DF[i];
            for(short i=0;i<FCI_TEMPLATE.length;i++)
                buf[4 + DF.length + i] = FCI_TEMPLATE[i];
            apdu.setOutgoingLength((short)(4 + DF.length + FCI_TEMPLATE.length));
            apdu.sendBytes((short)0,(short)(4 + DF.length + FCI_TEMPLATE.length));
            return;
        }

        switch (buf[ISO7816.OFFSET_INS]) {

            case (byte) 0xA4: //select PPSE
                //check that P1 & P2 are correct
                if(buf[ISO7816.OFFSET_P1] != (byte) 0x04 || buf[ISO7816.OFFSET_P2] != (byte) 0x00)
                    ISOException.throwIt(ISO7816.SW_INCORRECT_P1P2);

                //check that LC is 0x0E
                if((short)(buf[ISO7816.OFFSET_LC] & 0xFF) != 0x0E)
                    ISOException.throwIt(ISO7816.SW_WRONG_LENGTH);

                //get the rest of the apdu and check length
                if((short)(buf[ISO7816.OFFSET_LC] & 0xFF) != apdu.setIncomingAndReceive())
                    ISOException.throwIt(ISO7816.SW_WRONG_LENGTH);
                    //otherwise, the file name was wrong for this select
                else ISOException.throwIt(ISO7816.SW_FILE_NOT_FOUND);

            case (byte) 0xEE: //loopback
                //check that P1 & P2 are correct
                if(buf[ISO7816.OFFSET_P1] != (byte) 0x00 || buf[ISO7816.OFFSET_P2] != (byte) 0x00)
                    ISOException.throwIt(ISO7816.SW_INCORRECT_P1P2);

                //check that the length byte is within the spec (1-250)
                if((short)(buf[ISO7816.OFFSET_LC] & 0xFF) < 1 || (short)(buf[ISO7816.OFFSET_LC] & 0xFF) > 250)
                    ISOException.throwIt(ISO7816.SW_WRONG_LENGTH);

                //get the rest of the apdu and check length
                if((short)(buf[ISO7816.OFFSET_LC] & 0xFF) != apdu.setIncomingAndReceive())
                    ISOException.throwIt(ISO7816.SW_WRONG_LENGTH);

                short len = buf[ISO7816.OFFSET_LC];
                for(short i=0;i<len;i++)
                    buf[i] = buf[i+5];
                apdu.setOutgoingLength(len);
                apdu.sendBytes((short)0,len);
                break;

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


    }


}