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nfcsmartcardrfidmifare

mifare classic 4k reading to human readable form

i have mifare classic 4k and ACR1281U reader. I can authenticate/read/load succesfully.I have search the sites how to read the NFC tags but I am missing some; here are my questions

  1. how to read and convert the data from MIfare blocks to human readable form
  2. how to change the default auth key.

EDIT

Ok I just found out something strange. I tried to authenticate the random sector trailor block with the key A

FF FF FF FF FF FF

then i tried to read that trailor block i found this

00 00 00 00 00 00 FF 07 80 69 FF FF FF FF FF FF 90 00

what i am confused is acccording to documentation, in the sector trailer the key A comes first then access bits and then key b then response status

now what i get is 

keyb? | access bits | key A | response status

Note : i tried to authenticated with Key A which is FFFFFFFFFFFF and successfully authenticated.

could anyone explain this to me?

Thanks a lot.

Solution

  • To write a sector you need to authenticate on that sector with keyB. Then you can overwrite the key block as:

    new Key A | access bits | Key B