The authentication keys and the access conditions for each sector of a MIFARE card are located in the last block of that sector (the sector trailer). You can update this block with new access conditions and authentication keys using a regular write command. The sector trailer looks like this: +—————————–+————–+—-+—————————–+ | 0 | 1 | … Read more
The PWD_AUTH command that you send to the tag does not make much sense. The idea of the PWD_AUTH command is that you send your password (a 4-byte value) and that the tag responds with its password acknowledge (PACK) value (a 2-byte value) if you authenticated with the correct password. You can then verify the … Read more
With host-based card emulation (HCE) in Android 4.4 you can only emulate the ISO/IEC 14443-4 protocol. More specifically you can only emulate application structures according to ISO/IEC 7816-4 (thus card emulation applications need to be selected though an AID). Moreover, the API doesn’t give you any means to specify if card emulation should be done … Read more