msg+=tr(" Normally, the Block 0 of a typical Mifare card, which contains the UID, is locked during the manufacture. Users cannot write anything to Block 0 or set a new UID to a normal Mifare card.\n");
msg+=tr(" Chinese Magic Cards(aka UID Cards) are some special cards whose Block 0 are writeable. And you can change UID by writing to it.\n");
msg+="\n";
msg+=tr("There are two versions of Chinese Magic Cards, the Gen1 and the Gen2.\n");
msg+=tr(" Gen1:\n also called UID card in China. It responses to some backdoor commands so you can access any blocks without password. The Proxmark3 has a bunch of related commands(csetblk, cgetblk, ...) to deal with this type of card, and my GUI also support these commands.\n");
msg+=tr(" Gen2:\n doesn't response to the backdoor commands, which means that a reader cannot detect whether it is a Chinese Magic Card or not by sending backdoor commands.\n");
msg+="\n";
msg+=tr("There are some types of Chinese Magic Card Gen2.\n");
msg+=tr(" CUID Card:\n the Block 0 is writeable, you can write to this block repeatedly by normal wrbl command.\n");
msg+=tr(" (hf mf wrbl 0 A FFFFFFFFFFFF <the data you want to write>)\n");
msg+=tr(" FUID Card:\n you can only write to Block 0 once. After that, it seems like a typical Mifare card(Block 0 cannot be written to).\n");
msg+=tr(" (some readers might try changing the Block 0, which could detect the CUID Card. In that case, you should use FUID card.)\n");
msg+=tr(" UFUID Card:\n It behaves like a CUID card(or UID card? I'm not sure) before you send some special command to lock it. Once it is locked, you cannot change its Block 0(just like a typical Mifare card).\n");
msg+="\n";
msg+=tr(" Seemingly, these Chinese Magic Cards are more easily to be compromised by Nested Attack(it takes little time to get an unknown key).\n");
wh201906
4 years ago