AID and File ID of an application on a Desfire EV1,2,3 card

[Matthias-A]

Hi

I want to create an application on a Desfire card that I can access using ISO7816 commands. During application creation, I need to choose a ISODFName [1..16], ISOFileID[2], and an AID[3]. I read that there are rules about choosing an ISODFName (registration or proprietary application), but I can't find any restrictions or rules about choosing the ISOFileID and AID for the application except for some file ids (0x0000 0x3F00, 0x3FFF, 0xFFFF) and AIDS (0x000000) that can't be chosen. Am I missing some documentation or am I free to use any ISOFileID and AID except for those mentioned above.

Thanks in advance

Matthias

[Matthias-A]

I have signed an NDA, so I should be able to access these secure files. Which Secure Datasheet that you mentioned should contain this information? 

Best Regards

Matthias

[Fabian_R]

Yes, you should. Please take a look at the following User Manual for requesting access to these files: https://www.nxp.com/docs/en/user-guide/nxp-secure-access-rights-registration.pdf

[Matthias-A]

I have access to the secure files. The problem is that there is no document in the secure files section explaining what the restrictions or regulations are concerning Desfire AID en ISO File Id of an application.
In the link below is mentioned that you can register a Desfire AID, however it is still possible that other companies use the same AID. This makes no sense, why would you register if at the end there can still be a collision with other companies.
https://www.mifare.net/support/forum/topic/mifare-aid-registration/

In this link is mentioned that you can create your own Desfire AID except for 0x000000. But can I choose whatever AID that I want? This will definitely result in collisions.
https://www.mifare.net/support/forum/topic/desfire-aid/

In which document of the secure files can I find the regulations concerning the Desfire AID or ISO File id of an application.

Thank you
Matthias

[Matthias-A]

I do have access to the secure files, however there is no document that explains what restrictions apply on choosing a Desfire AID 0x000000, Iso File ID: 0x0000. The only thing that I could find, is that an ISO DF name of an application can be in the unregistered range or else a registration process needs to be fulfilled. Here I read that you can register a Desfire AID, but someone answered that it it still possible that other companies can use the same Desfire AID without registration...  https://www.mifare.net/support/forum/topic/mifare-aid-registration/

What I need to know is whether I can choose the Desfire AID and ISO File Id freely, or that I need to comply with restrictions, registrations or ....

Regards

Matthias

[Fabian_R]

Hello sir,

As is mentioned in the Datasheet, an application (AID) is able to contain more than one File, which makes the creation of an AID required. We highly recommend following the MIFARE Application Directory for a standardized creation of the Application Identifiers.

In section 3.10 MAD and MIFARE DESFire defined how the AID's structure is built.

Since a structured AID will ensure a scalable card project.

[Matthias-A]

Ok thank you.

I can read in that document that a Mifare classic application can be registered free of charge.
Since I don't want a Mifare classic application but a Desfire Application, is that registration still relevant because the Mifare classic application id is element of the bigger Desfire application id, or is there another authority responible to register the Desfire application ID's.

It is explained that bit number 8 to 5 of first byte is 'F' and that means that it is in the Proprietary category, no registration is necessary. What will be the value of those 8 to 5 bits of the first byte when I want to register a desfire AID.

Let's say I create an application for access control with a registered ISO DF Name: 0xaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa. During application creation, am I free to use any Mifare Desfire AID for instance 0xF48000 and as ISO File Id am I free to choose for instance 0xF480? Am I then 100 % in line with the regulations about application creation?

I am sure that the ISO DF name is unique since we registered it, however what I understand about the Desfire AID and ISO File ID of the application, is that it is not unique with certainty unique and it is possible that another company already is using the same Desfire AID or ISO File ID.

Thank you for your response
Regards
Matthias

[Fabian_R]

Hello, my name is Fabian, I've been assigned to support your case.

I appreciate your interest in our products.

This information is described in the Secure Datasheet, in order to request access to it, you will need to sign an NDA. Please follow the next link: https://www.nxp.com/webapp-signup/ndaReqForm

For more information about NDA please follow the next link: https://www.nxp.com/support/support/non-disclosure-agreement-faqs:NDA-FAQS

I'm very sorry that I'm not able to provide more information but, this is secured and, I cannot discuss it through this channel since it isn't secure.