LaNCer (lan-nfc-computer-unlocker)

Lancer is a client/server nfc computer unlocker.

Architecture

• One or several Arduino(s) can be used as client(s).
• There is a centralized user management on the server.
• When a user scan a nfc tag on the Arduino, an access request is made to the server via a webservice.
• If the tag is recognized, then the password is entered via the Arduino keyboard (the computer is locked first to avoid writing the password anywhere).

Warning

The encryption used is weak (xor + base64), plus the card id (which can be falsifiable) is used to identify the user. Don't use this in a production environement.

Notes

• If there is a user's switch on a computer, the new account must be selected before scanning the tag, otherwiser the wrong account will be used.
• The unlocker part can easily be customized to unlock more than only computers (doors, etc). In this case, the Leonardo is not a requirement (it is only for the emulated keyboard).

Hardware requirements

• Arduino Leonardo
• Adafruit PN532 shield
• Ethernet shield

Software requirements

• Apache, MySQL, PHP
• Composer
• Arduino IDE with following libraries: adafruit/Adafruit-PN532, bblanchon/ArduinoJson, agdl/Base64

Installation

• Initialize MySQL DB with provided script.
• Server: use Composer to install dependencies. Configure DB and encryption key in src/settings.php.
• Client: configure server, subfolder, encryption key (must be the same as the key on the server) and OS. Upload the code onto the Arduino.

Usage

• Add a user: grab the user's NFC card id via the serial console on the Arduino IDE. Create a new user with this card id and his password on the server's admin interface.