Laundry card top up

Top up the credit on a very specific type of NFC laundry card

For more info about MIFARE Classic cards and how to hack them see: https://apididafoo.gitbook.io/mifare-classic/hacking-my-laundry-cards

The B key for sectors 1 and 2 must be provided (see here how to get it)

Dependencies

$ sudo apt install libnfc-bin libfreefare-bin

Tested on Ubuntu 22.04 with libnfc-bin 1.8.0-2 and libfreefare-bin 0.4.0-2.1build1

Example usages

Show current credit

$ ./topup 97a4e7fe952c
The current credit value is 1.50

Set credit

$ ./topup -s 50 97a4e7fe952c
The current credit value is 1.50
Credit set to 50.00

$ ./topup 97a4e7fe952c
The current credit value is 50.00

Verbose output

$ ./topup -v 97a4e7fe952c
Using B key 97a4e7fe952c to authenticate to sectors 0x01 and 0x02
Using libnfc 1.8.0
Using libfreefare <unknown version>
Listing devices...
Found 1 device(s):
 - pn532_uart:/dev/ttyUSB0
Using pn532_uart:/dev/ttyUSB0
Open pn532_uart:/dev/ttyUSB0
Adafruit PN532 board via UART ready
Using tag Mifare Classic 1k with ID c45ceced
The current credit value is 50.00

Links

• libnfc
• libfreefare