My applet returns 16 bytes of 0 instead of AES encrypted value,why?

[NikerCR]

I am writing a java card applet to encrypt 16 bytes of incoming APDU command data section and return the encrypted value.
My code:

Code: Select all

public class DoAES extends Applet {

    static Cipher myCipher;
    static AESKey myAESKey;
    byte[] cipheredData = JCSystem.makeTransientByteArray((short) 0x10, JCSystem.CLEAR_ON_RESET);

    final static byte SET_KEY = (byte) 0x12;
    final static byte WRITE_TEXT = (byte) 0x04;
    final static byte READ_TEXT = (byte) 0xC0;

    private DoAES() {

        try {
            myCipher = Cipher.getInstance(Cipher.ALG_AES_BLOCK_128_ECB_NOPAD, false);
            myAESKey = (AESKey) KeyBuilder.buildKey(KeyBuilder.TYPE_AES,
                    KeyBuilder.LENGTH_AES_128, false);
        } catch (CryptoException e) {
            ISOException.throwIt(((CryptoException) e).getReason());
        }
    }

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

    public void process(APDU apdu) throws ISOException {
        if (selectingApplet()) {
            return;
        }

        byte[] buffer = apdu.getBuffer();

        if ((buffer[ISO7816.OFFSET_CLA] & 0x00FF) != 0x80) {
            ISOException.throwIt(ISO7816.SW_CLA_NOT_SUPPORTED);
        }

        try {
            switch (buffer[ISO7816.OFFSET_INS]) {

                case SET_KEY:
                    myAESKey.setKey(buffer, (short) ISO7816.OFFSET_CDATA);
                    myCipher.init(myAESKey, Cipher.MODE_ENCRYPT);
                    break;

                case WRITE_TEXT:
                    myCipher.doFinal(buffer, (short) ISO7816.OFFSET_CDATA, (short) 0x10, cipheredData, (short) 0);
                    break;

                case READ_TEXT:
                    Util.arrayCopyNonAtomic(cipheredData, (short) 0, buffer, (short) 0, (short) 0x10);
                    apdu.setOutgoingAndSend((short) 0, (short) 0x10);
                    break;

                default:
                    ISOException.throwIt(ISO7816.SW_INS_NOT_SUPPORTED);
            }
        } catch (CryptoException e) {
            ISOException.throwIt(((CryptoException) e).getReason());
        }
    }
}

The sending / received APDUs are as follows
>> 00 A4 04 00 06 81 82 83 84 85 01
<< 90 00

>> 80 12 00 00 10 00 11 22 33 44 55 66 77 88 99 AA BB CC DD EE FF
<< 90 00

>> 80 C0 00 00
<< 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ...

Why my applet returns 16 bytes of 0 instead of AES encrypted value?

[btwtiger]

Hi bro.
please send encryption APDU first.
80 04 00 00 10 11 22 33 44 55 66 77 88 99 AA BB CC DD EE FF

Then try to read array by 80 C0 00 00