EMVExternalVerification.java

public class Main {
    public static byte[] externalAuthenticate(byte[] cryptogram, byte[] proprietaryBytes) {
        if (cryptogram == null) {
            throw new IllegalArgumentException("Argument 'cryptogram' cannot be null");
        }
        if (cryptogram.length != 8) {
            throw new IllegalArgumentException("Argument 'cryptogram' must have a length of 8. length=" + cryptogram.length);
        }
        if (proprietaryBytes != null && (proprietaryBytes.length < 1 || proprietaryBytes.length > 8)) {
            throw new IllegalArgumentException("Argument 'proprietaryBytes' must have a length in the range 1 to 8. length=" + proprietaryBytes.length);
        }
        int length = cryptogram.length;
        ByteArrayOutputStream stream = new ByteArrayOutputStream();
        stream.write(0x00); //CLA
        stream.write(0x82); //INS
        stream.write(0x00); //P1
        stream.write(0x00); //P2
        if (proprietaryBytes != null) {
            length += proprietaryBytes.length;
        }
        stream.write(length);
        stream.write(cryptogram, 0, cryptogram.length);
        if (proprietaryBytes != null) {
            stream.write(proprietaryBytes, 0, proprietaryBytes.length);
        }
        stream.write(0x00); //Le
        return stream.toByteArray();
    }

    public static void main(String[] args) {
        byte[] cryptogram = new byte[]{0x4E,0x29,0x20,0x46,0x02,0x03,0x38,0x51};
        byte[] externalAuthenticate = externalAuthenticate(cryptogram,null);
        for (byte b : externalAuthenticate) {
            System.out.printf("%02X ", b);
        }
    }
}