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androidsecuritynfcmifare

How to use security feature provided in desfire from android?

I know how to read and write ndef messages from a Mifare DESFire tag, but i'm having difficulty as to understand how to use the command set supported by DESFire when it comes to communicating from Android.

  1. I know it has something to do with transceive(byte[]) function which help in communicating through raw bytes. How do i use it?

  2. How do i lock the message with custom key?

Solution

  • IsoDep.transceive() is indeed the proper method. You can send ISO7816-4 APDUs (like the ones from the NFC Forum Type 4 Tag specification) to the tag or use the DESfire-specific command set to communicate with the tag (see http://www.nxp.com/documents/short_data_sheet/MF3ICDX21_41_81_SDS.pdf for a high-level overview).

    Locking a message with a custom key requires the use of the DESFire-specific commands. Details for that are described in the datasheet, which is available upon request from NXP; see http://www.nxp.com/products/identification_and_security/smart_card_ics/mifare_smart_card_ics/mifare_desfire/MF3ICD2101DUD.html