Encrypting data on card

Question

Hello, I was hoping somebody would be able to explain some queries I have regarding encryption. I have been attempting to encrypt data in my card but I have been unable to find enough documentation to cover the topic thoroughly. What I have done is;
Declare my variables:
protected byte[] KeyData;
protected Key des_key;
protected Cipher cipher;
I have then initialised them in my constructor prior to a call to the register method, as follows:
// Create DES key
DESKey des_key = (DESKey)KeyBuilder.buildKey(KeyBuilder.TYPE_DES, KeyBuilder.LENGTH_DES, false);
// Initialise DES key
KeyData = new byte[]{(byte)1};
des_key.setKey(KeyData, (short)0);
// Create Cipher object with the DES algorithm
cipher = Cipher.getInstance(Cipher.ALG_DES_CBC_NOPAD, false);
// Initialise with DES key for encryption
cipher.init(des_key, Cipher.MODE_ENCRYPT);
register();
In one of my methods, I then attempt to encrypt data contained in the byte array 'temp':
// Encrypt data and write into jcname array
cipher.doFinal(temp, Offset, len, jcname, Offset);
When I have tested this in jcwde the create method fails with the sw()6444.
I'm afraid I don't understand how the Key is created or what should be contained within the KeyData array, this may be where my problem is arising. If you can help or provide some explanation of what is happening I would be very grateful. TIA
Tony

Answer 1

The error code you are getting is because the crypto isn't implemented. The crypto is hardcoded to return that. If you peek at the code, you'll see that none of the cyrpto packages are implemented.
So you have to write them yourself or find an implementation somewhere.
When you buy a kit from a vendor, the cards will contain some form of crypto ( DES, 3DES, RSA) and you can fully test it out that way.