Am working on a project to read from and write data to SLE 4442 smart cards. The Card Reader am using is ACR38 from ACS. Following their APDU commands, I have being able to get access to the card and read some data. But am suspecting that I still have not being able to read the exact data inside. This is because, anytime my application is started, it brings out new data. I really don't know why is behaving that way, can somebody please spot where am getting wrong here? Below is my Java code:
CardChannel channel = card.getBasicChannel();
byte[] read_memory_card = {(byte) 0xFF, (byte) 0xB0, (byte) 0xA7A6A5A4, (byte) 0xA3A2A1A0, (byte) 0x00};
ResponseAPDU read_data_resp = channel.transmit(new CommandAPDU(read_memory_card));
if (read_data_resp.getSW1() == 0x90 && read_data_resp.getSW2() == 0x00) {
System.out.println("Data in Card: " + read_data_resp.getData() + "and SW1: " + read_data_resp.getSW1());
}
What I get as a result:
Data in Card: [B@378bf509 and SW1: 144
Please note that Data in Card changes every time, the application is restarted.
I'm assuming that you seeing "different" data isn't so much that it is truly different but rather you are printing out the pointer in memory that Java uses as a default toString(). I can only assume that read_data_resp.getData() retuurns a byte[] in which case you'll want to convert each value into a string if you want to visualize it. If you search google on how to convert a byte array to a hex string you'll find lots of answers.