hypebeast

class crc8:
	def __init__(self):
		self.crcTable = (0x00, 0x07, 0x0e, 0x09, 0x1c, 0x1b, 0x12, 0x15, 0x38,
				 0x3f, 0x36, 0x31, 0x24, 0x23, 0x2a, 0x2d, 0x70, 0x77,
				 0x7e, 0x79, 0x6c, 0x6b, 0x62, 0x65, 0x48, 0x4f, 0x46, 
				 0x41, 0x54, 0x53, 0x5a, 0x5d, 0xe0, 0xe7, 0xee, 0xe9, 
				 0xfc, 0xfb, 0xf2, 0xf5, 0xd8, 0xdf, 0xd6, 0xd1, 0xc4, 
				 0xc3, 0xca, 0xcd, 0x90, 0x97, 0x9e, 0x99, 0x8c, 0x8b, 
				 0x82, 0x85, 0xa8, 0xaf, 0xa6, 0xa1, 0xb4, 0xb3, 0xba, 
				 0xbd, 0xc7, 0xc0, 0xc9, 0xce, 0xdb, 0xdc, 0xd5, 0xd2,

alphazo

libnfc supports UUID writable cards and even has some dedicated tools for them.

However it doesn't work with some of the cards found on eBay that are even simpler to use. Sector 0 is unlocked and can be written without any additional commands. libnfc requires a small patch to get it working.

Following has been tested under ArchLinux with modified libnfc 1.5.1, mfoc 0.10.2 and a SCL3711 dongle.

Patch & recompile libnfc

The patch is fairly simple, open libnfc-1.5.1/utils/nfc-mfclassic.c and comment 2 lines (it was lines 384 and 385 for me):

// Try to write the trailer