EMV External Authenticate commands Returns 6982

Question

I am new in EMV technology working with java as my preferred language. I am trying to execute External Authenticate Command and am getting error 6982. In my external authenticate command I am supposed to pass cmac & host cryptogram as my data field and I don't know how its calculated as per EMV book. My question is how can I get C-MAC and host cryptogram in java to pass as data in my external Authenticate command.

Here is my external authenticate command

CLA  INS P1 P2 LC Data Field
84   82  00 00 10  (Host Cryptogram & C-MAC)

So far I have managed to run select and initialize update successfully and retrieved KEY DATA.

I have tried this but I don't understand it.

Answer 1

There are different algorithms to calculate ARPC as well as different methods to derive keys, but no calculation happens on the client side. You should not calculate it unless you are a card issuer.

It will simply be part of the response to the authorization request.