JavaCard OS

Hi all!
I tested DES decryption on java card and I also did comparison between java card and java.
I got the following result:
In update method, DES CBC (M1, M2, or, PK5);
- If implementing in java, I need to have at least 16 bytes input to have output data.
- If implementing in java card, I need to have at least 8 byte to have output data.

So what reason results in this difference?

If anyone can share your knowledge with me, I would be greatly appreciated.

For Java implementation, Do you get 8 bytes in the response? If you have 8 bytes only, you should call doFinal(...).

Tarantino wrote:For Java implementation, Do you get 8 bytes in the response? If you have 8 bytes only, you should call doFinal(...).

@Tarantino, Thanks for your answer!

I do understand that calling doFinal will give me final result.
The problem is that in Java, there will be no output after calling update if input data is less than 16 bytes
However, javacard will give output of update method if the input data is more than 8 bytes length.

Just keep in mind that you should not rely on intermediate results of update anyway since the operation is not complete until doFinal is called.