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/** * @file Communication.java * @brief Communication Sample Code in JavaCard API Specification * @comment The purpose of this example is only used to show the usage of API functions and there is no practical significance. * @copyright Copyright(C) 2016 JavaCardOS Technologies Co., Ltd. All rights reserved. */ package JavaCardOS.Sample.Communication; import javacard.framework.*; import javacardx.apdu.ExtendedLength; public class Communication extends Applet implements ExtendedLength { public static final byte INS_SEND_RECV_APDU_1 = 0x01; public static final byte INS_SEND_RECV_APDU_2 = 0x02; public static final byte INS_RECV_EXTEND_APDU = 0x03; public static final byte INS_SEND_EXTEND_APDU = 0x04; private byte[] tmp_memory; public static final short MAX_LENGTH = (short)(0x7FFF); public static void install(byte[] bArray, short bOffset, byte bLength) { new Communication().register(bArray, (short) (bOffset + 1), bArray[bOffset]); } public void process(APDU apdu) { if (selectingApplet()) { return; } Get the apdu buffer datas byte[] buf = apdu.getBuffer(); byte cla= buf[ISO7816.OFFSET_CLA]; byte ins = buf[ISO7816.OFFSET_INS]; byte p1 = buf[ISO7816.OFFSET_P1]; byte p2 = buf[ISO7816.OFFSET_P2]; short p1p2 = Util.makeShort(p1, p2); if (cla != (byte)0x80) { ISOException.throwIt(ISO7816.SW_CLA_NOT_SUPPORTED); } if (p1p2 != 0x00) { ISOException.throwIt(ISO7816.SW_WRONG_P1P2); } Calling this method indicates that this APDU has incoming data. short recvLen = apdu.setIncomingAndReceive(); Get the incoming data length(Lc). short lc = apdu.getIncomingLength(); if (lc == 0x00) { ISOException.throwIt(ISO7816.SW_WRONG_LENGTH); } switch (ins) { case (byte)INS_SEND_RECV_APDU_1: Define a byte string byte sendStr[] = {'A','P','D','U', ',', 'C','l','a','s','s', ',', 'D','e','m','o'}; short len = (short) sendStr.length; Copy character to APDU Buffer. Util.arrayCopyNonAtomic(sendStr, (short)0, buf, (short)0, (short)len); Send the 'sendStr' string, the hex of JCRE sending data is the ASCII of sendStr. apdu.setOutgoingAndSend((short)0, (short)len); break; case (byte)INS_SEND_RECV_APDU_2: Set the length of received bytes into the 'buf' array, the offset is 0. Util.setShort(buf, (short)0, (short)lc); Set the data transfer direction to outbound. short le = apdu.setOutgoing(); Set the expected(le) length of response data. apdu.setOutgoingLength((short)le); Sends the data of APDU buffer 'buf', the length is 'le' bytes, the offset is 0. apdu.sendBytes((short) 0, (short)le); break; case (byte) INS_RECV_EXTEND_APDU: short pointer = 0; tmp_memory = new byte[MAX_LENGTH]; short offData = apdu.getOffsetCdata(); recvieve data and put them in a byte array 'tmp_memory' while (recvLen > (short) 0) { Util.arrayCopy(buf, offData, tmp_memory, pointer, recvLen); pointer += recvLen; Gets as many data bytes as will fit without APDU buffer overflow recvLen = apdu.receiveBytes(offData); } send the lc length apdu.setOutgoing(); apdu.setOutgoingLength((short)2); Util.setShort(buf, (short)0, lc); apdu.sendBytesLong(buf, (short) 0, (short)2); break; case (byte) INS_SEND_EXTEND_APDU: if(buf[ISO7816.OFFSET_LC] != 0x02) { ISOException.throwIt(ISO7816.SW_WRONG_LENGTH); } short sendLen = Util.getShort(buf, ISO7816.OFFSET_CDATA); send the specified length data in byte array 'tmp_memory' apdu.setOutgoing(); apdu.setOutgoingLength(sendLen); apdu.sendBytesLong(tmp_memory, (short)0, sendLen); request Object Deletion tmp_memory = null; JCSystem.requestObjectDeletion(); break; default: ISOException.throwIt(ISO7816.SW_INS_NOT_SUPPORTED); } } } ''