How to make apdu.getBuffer() return buf that is greater than 133 bytes.

Question

    public void process(APDU apdu) {
      byte[] buf = new byte[256];
        buf = apdu.getBuffer();
        // GOOD PRACTICE: RETURN 9000 ON SELECT
        if (selectingApplet()) {
            return;
        apdu.setIncomingAndReceive();
        switch (buf[ISO7816.OFFSET_INS]) {
            case (byte) 0x01:
This is my process method. I have a command APDU of length 200 bytes that I want the buffer to read and store into a local byte array. However, apdu.getBuffer() is only grabbing the first 133 bytes of data.
According to javadocs:
"The APDU object is owned by the Java Card runtime environment. The APDU class maintains a byte array buffer which is used to transfer incoming APDU header and data bytes as well as outgoing data. The buffer length must be at least 133 bytes ( 5 bytes of header and 128 bytes of data ). The Java Card runtime environment must zero out the APDU buffer before each new message received from the CAD."
Since the buffer length is larger than 133 bytes, why does it not accept the remaining bytes?
I am using jCardSim on NetBeans IDE, java card version 2.2.2.
Also, could someone explain to me what exactly apdu.setIncomingAndReceive() does? My code is able to build/run both with and without it.
Thanks

Answer 1

I tried using that in my code, but it's still not working, I must be placing it in the wrong spot. I put it in the process method right before my switch cases. Do I actually put all of the code in the while loop? Perhaps you could explain the code to me, why do you only want the last two bytes of LC, and why 55? This is what it looks like currently:
    public void process(APDU apdu) {
        byte[] buf = apdu.getBuffer();
        // GOOD PRACTICE: RETURN 9000 ON SELECT
        if (selectingApplet()) {
            return;
       short bytesLeft = (short) (buf[ISO7816.OFFSET_LC] & 0x00FF);
        if (bytesLeft < (short) 55) {
            ISOException.throwIt(ISO7816.SW_WRONG_LENGTH);
        short readCount = apdu.setIncomingAndReceive();
        while (bytesLeft > 0) {
            // process bytes in buffer[5] to buffer[readCount+4]; 
            bytesLeft -= readCount;
            readCount = apdu.receiveBytes(ISO7816.OFFSET_CDATA);
        // HARDCODED PARAMETERS TO PASS INTO FUNCTIONS
        byte[] O = new byte[6];
        byte[] U = new byte[3];
        byte[] N = new byte[5];
        byte[] A = new byte[4];
        Util.arrayCopy(buf, (short) (ISO7816.OFFSET_EXT_CDATA), O, (short) 0, (short) 6);
        Util.arrayCopy(buf, (short) (ISO7816.OFFSET_EXT_CDATA + 7), U, (short) 0, (short) 3);
        Util.arrayCopy(buf, (short) (ISO7816.OFFSET_EXT_CDATA + 11), N, (short) 0, (short) 5);
        Util.arrayCopy(buf, (short) (ISO7816.OFFSET_EXT_CDATA + 17), A, (short) 0, (short) 4);
        switch (buf[ISO7816.OFFSET_INS]) {
            case (byte) 0x01:
                // CALL FUNCTION  R
                byte[] b = R(O, U, N, A);
                // PRINT B
                apdu.setOutgoing();
                apdu.setOutgoingLength((short) b.length);
                apdu.sendBytesLong(b, (short) 0, (short) b.length);
                break;
            case (byte) 0x02:
                byte[] k2 = new byte[(short) 176];  
                //29 is the offset in the command apdu that contains the parameter data
               // THIS IS THE LINE THAT THE CODE FAILS AT - SINCE IT CAN ONLY READ 133 BYTES OF DATA, IT CAN'T ARRAY COPY 176 BYTES OF DATA FROM buf
                Util.arrayCopy(buf, (short) 29, k2, (short) 0, (short) 176);
                byte[] a = S(k2, O, U, N);
                // PRINT a
                apdu.setOutgoing();
                apdu.setOutgoingLength((short) a.length);
                apdu.sendBytesLong(a, (short) 0, (short) a.length);
                break;