How can I read the purse balance with an EMV CARD?

Question

I'm working with a smart card reader and I'm finding some trouble about getting the purse balance from an EMV card. I have developed software for other cards with t=0, protocol, but this time this process is killing me.

I supposse it has to be something like :

Select Purse balace File Read Record.

I did not find this file, and then I saw in the specifications this:

It's mandatory to: 1.-select the PSE 2.-Read Record 3.-Get processing options 4.-Read Record 5.-Get Chanllenge command 6.-Get Data command

I honestly think with command 6 I will obtain what I'm looking for, the problem is that I cannot select the pse, but instead I can select the AID standard visa file.

What am I doing wrong?

Thanks

Answer 1

When you say 'cannot select the PSE', what do you exactly mean? Are you getting '6A 82' status? Take note that the PSE is a DDF (directory). You need to read its records to get the actual Application IDs. After getting the App. IDs from PSE, you need to know which of these IDs is the AID of the purse application you are going to select.

If you know the AID of the purse application, you can even bypass the PSE processing. You can just select the application by specifying the AID. From there you can proceed by issuing the GET PROCESSING OPTIONS command, READ RECORD and so on.