1 (edited by hermes55555 2016-02-03 00:57:18)

Topic: incorrect BCC in MFD


I am trying to backup one of my mifare access cards. I have no problems in creating the dump. While trying to write a blank chinese card(writeable UUID) with this dump, I get the following error message: "incorrect bcc in mfd file".

Does my mifare access card have a wrong bcc?

What happens if I somehow manage to write the UUID with a hex that doesn't conform with the BCC check? Will I brick my Chinese card? Is this possible by removing this security feature from the source code of nfc-mfclassic?

if (uiBlock == 0) {
00447           if ((mp.mpd.abtData[0] ^ mp.mpd.abtData[1] ^ mp.mpd.abtData[2] ^ mp.mpd.abtData[3] ^ mp.mpd.abtData[4]) != 0x00 && !magic2) {
00448             printf("!\nError: incorrect BCC in MFD file!\n");
00449             printf("Expecting BCC=%02X\n", mp.mpd.abtData[0] ^ mp.mpd.abtData[1] ^ mp.mpd.abtData[2] ^ mp.mpd.abtData[3]);
00450             return false;