This is a sample application for a sandwich fidelity card built with libfreefare / libnfc using Mifare DESFire cards.

In order to build and use this software, you'll need at least:

• openssl library including development headers
• libnfc 1.5.1
• libfreefare 0.3.2
• pkg-config files should be in place for the above named libs
• swig (tested with 2.0.4) (to generate the python bindings)
• gcc (tested with 4.6.2) or llvm/clang
• pyGtk (for the graphical interface)
• python2 (tested with python 2.7)
• make (tested with GNU Make 3.82)
• pcsclite pcscd etc ... if your reader is not directly supported by libnfc

After obtaining the code from tarball:

user$: cd sandwich
user$: make
user$: sudo make install

In order to extract the public keys the tool 'extract-public-keys' in the subfolder 'tools' can be used. To invoke it :

user$: ./tools/extract-public-keys directory-with-certs ca-file output-directory

Each of the certificates will be verified using the given CA certificate. After invoking the command the extracted public keys in PEM format can be found in 'output-directory/certs'.

Please note, you have to obtain the keys / certificates prior to running the application. To run the applications without installing them you can do the following after building:

user$: export LD_LIBRARY_PATH=$PWD/lib

However this assumes that you're in the directory where you extracted the sources to.

To initialise a card type:

user$: ./apps/initialise-card [global_public.pem] [global_private.pem] [shop_public.pem] [shop_private.pem]

Where global_public.pem denotes the file containing the public key known to all shops, global_private.pem the private key known to all shops, shop_public.pem and shop_private.pem denote the keys known only to the issuing shop.

To analyse a card's contents, type:

user$: ./apps/analyse-card keys/global_private.pem keys

Where global_private.pem denotes the file containing the private key known to all shops, and keys the directory containing the public keys extracted from the shops before in PEM format.

To increase the counter / buy a sandwich, type:

user$: ./apps/buy keys/global_private.pem keys/shop_private.pem

Where global_private.pem denotes the file containing the private key known to all shops, and shop_private.pem the key known to the shop where the sandwich is about to be bought.

We also designed a more user-friendly version of the software. (It requires Python 2.7 and gtk3 bindings for Python.)

To use the graphical version:

user$: cd swig
user$: python nice_gui.py