EMVGenerateAC.java

        /**
         * p1 &= 0b00111111 = AAC = reject transaction (EMVApplication Authentication Cryptogram)
         * p1 &= 0b10111111 = TC = proceed offline (Transaction Certificate)
         * p1 &= 0b01111111 = ARQC = go online (Authorization Request Cryptogram                                                                            ) +
         * 0x00 = CDA signature not requested
         * 0x10 = CDA signature requested
         */
        ByteArrayOutputStream buf = new ByteArrayOutputStream();
        byte[] authorizedAmount = Util.fromHexString("00 00 00 00 01 00"); // 1 Rs
        byte[] secondaryAmount = Util.fromHexString("00 00 00 00 00 00");  // 0 Rs
        byte[] tvr = Util.fromHexString("00 00 00 00 00"); //Terminal verification results (TVR)
        byte[] transactionCurrencyCode = Util.fromHexString("03 56"); // 356 currency code for INR
        byte[] transactionDate = Util.fromHexString("09 07 23"); // 09/07/2023
        byte[] transactionType = Util.fromHexString("00"); // 00 for sale/purchase
        byte[] terminalUnpredictableNumber = Util.generateRandomBytes(4);
        byte[] dataAuthenticationCode = new byte[2];
        buf.write(authorizedAmount, 0, authorizedAmount.length);
        buf.write(secondaryAmount, 0, secondaryAmount.length);
        buf.write(tvr, 0, tvr.length);
        buf.write(transactionCurrencyCode, 0, transactionCurrencyCode.length);
        buf.write(transactionDate, 0, transactionDate.length);
        buf.write(transactionType, 0, transactionType.length);
        buf.write(terminalUnpredictableNumber, 0, terminalUnpredictableNumber.length);
        buf.write(iccDynamicNumber, 0, iccDynamicNumber.length);
        buf.write(dataAuthenticationCode, 0, dataAuthenticationCode.length);
        byte[] transactionRelatedData = buf.toByteArray();
        byte[] cmd = new byte[5+transactionRelatedData.length+1];
        cmd[0] = (byte)0x80; //Cls
        cmd[1] = (byte)0xAE; //INS
        cmd[2] = (byte)0x40; //P1
        cmd[3] = (byte)0x00; //P2
        cmd[4] = (byte)transactionRelatedData.length;
        System.arraycopy(transactionRelatedData, 0, cmd, 5, transactionRelatedData.length); //Data
        cmd[cmd.length-1] = 0x00; //Le
        for (byte b : cmd) {
            System.out.printf("%02X ",b);
        }