NFC bug - missed sector reads

I have a pair of MiFare Classic cards with known keys A1A1A1A1A1A1 (key A) and A0A1A2A3A4A5 (key B) for all sectors:
$ xxd nfap.mfd | grep ‘a1a1 a1a1’
00000030: a1a1 a1a1 a1a1 ff0f 00c1 a0a1 a2a3 a4a5 …
00000070: a1a1 a1a1 a1a1 ff0f 0000 a0a1 a2a3 a4a5 …
000000b0: a1a1 a1a1 a1a1 ff0f 0000 a0a1 a2a3 a4a5 …
000000f0: a1a1 a1a1 a1a1 ff0f 0000 a0a1 a2a3 a4a5 …
00000130: a1a1 a1a1 a1a1 ff0f 0000 a0a1 a2a3 a4a5 …
00000170: a1a1 a1a1 a1a1 ff0f 0000 a0a1 a2a3 a4a5 …
000001b0: a1a1 a1a1 a1a1 ff0f 0000 a0a1 a2a3 a4a5 …
000001f0: a1a1 a1a1 a1a1 ff0f 0000 a0a1 a2a3 a4a5 …
00000230: a1a1 a1a1 a1a1 ff0f 0000 a0a1 a2a3 a4a5 …
00000270: a1a1 a1a1 a1a1 ff0f 0000 a0a1 a2a3 a4a5 …
000002b0: a1a1 a1a1 a1a1 ff0f 0000 a0a1 a2a3 a4a5 …
000002f0: a1a1 a1a1 a1a1 ff0f 0000 a0a1 a2a3 a4a5 …
00000330: a1a1 a1a1 a1a1 ff0f 0000 a0a1 a2a3 a4a5 …
00000370: a1a1 a1a1 a1a1 ff0f 0000 a0a1 a2a3 a4a5 …
000003b0: a1a1 a1a1 a1a1 ff0f 0000 a0a1 a2a3 a4a5 …
000003f0: a1a1 a1a1 a1a1 ff0f 0000 a0a1 a2a3 a4a5 …

If I use the extensive nfc/assets/mf_classic_dict.nfc (and adding the missing A1A1A1A1A1A1), reading this card takes quite a bit of time, due to the sheer number of keys in this file.

If I replace this dict with a file containing only the two keys I’m looking for, it gets - at most - 23 out of the 32 sectors, though this tends to vary each time I run the read. Adding several more gets me to 30 or 31 sectors read:
Screenshot-20220503-195032

Essentially, I suspect that a delay between reading sectors (I’ve used a 250 ms delay with success with the mfcuk util) may need to be introduced here.

While we’re at it, I’d love to see the optional ability to specify keys for given cards on the Flipper, if at all possible - and, while I know that Classic cards are not yet emulated by the Flipper, you can add my name to the list of people interested in this functionality!

Thanks guys - the Flipper is an awesome little device.

Hi! What firmware version are you using? This should be fixed in the latest dev build

I was using the latest dev build as of yesterday. I’ll update it and check, though!

1 Like

Unfortunately, it appears I’m already running the latest, 7017fa4f:

1 Like