Nfc

libnfc

libnfc is the open source Near Field Communication library on Linux. It supports most hardware based on NXP chips (PN53x).

Install:

• Add apt repository

sudo add-apt-repository ppa:jdthood/nfc-tools

• Package is only available for release quantal, so if needed edit apt file /etc/apt/sources.list.d/jdthood-nfc-tools-precise.list
• Install libnfc packages:

sudo apt-get install libnfc-bin libnfc-dev libnfc-examples mfoc
sudo apt-get install libccid pcscd          # As per install instruction http://nfc-tools.org/index.php?title=Libnfc

References:

• http://nfc-tools.org/index.php?title=Libnfc

SCL3711

The SCL3711 is a very small smartcard reader from Identive. It contains a PN533 chip from NXP.

The reader works very well with libnfc. To use it on a recent kernel (like Ubuntu Precise) however, you must blacklist the pn533 and nfc modules:

# To make my SCL3711 works:
sudo vi /etc/modprobe.d/blacklist-libnfc.conf   # As per http://www.libnfc.org/community/topic/668/solved-scl3711-interface-0-claimed-by-pn533-nfclist-sets-conf/
                                                # Type:
                                                #    blacklist pn533
                                                #    blacklist nfc 
# unplug device
sudo modprobe -r pn533 nfc                      # Unload the modules

Once detected, you can easily tags in the reader field with:

nfc-list

References:

• http://www.libnfc.org/community/topic/668/solved-scl3711-interface-0-claimed-by-pn533-nfclist-sets-conf/

MIFARE Classic keys

Dump memory

Dump MIFARE Classic memory:

nfc-mfclassic r a test.dump      # Read, using A key (no key given, so assuming one in default keyset)

mfoc

mfoc can brute-force MIFARE Classic, if at least one key is known (needed to be able to collect some information leaking from random generator).

• Search for keys, assuming one key in the default keyset (see mfoc source code for a list)

mfoc -O test.dump

More information:

• http://www.backtrack-linux.org/wiki/index.php/RFID_Cooking_with_Mifare_Classic

mfcuk

mfcuk may brute a key even if no keys are known. Ideally we use it to guess one key, and then switch back to mfoc.

Best line:

./mfcuk -C -R 0 -v 3 -s 250 -S 250 -o dump.bin      # Search sector 0

References:

• http://www.libnfc.org/community/topic/98/mifare-classic-key-recovery-tool-dark-side-attack/page/3/