tuerd

General

The tuerd (Tür Daemon) is the core part of the Entropian lock system infrastructure. Its responsibility is to open the door using a motor lock if a valid token is presented to the RFID reader.

Current state of the "art":

    flowchart LR


    KEYREPO[(Key Git Repository)]
    TUERD[tuerd]
    TUERDMANAGE[tuerd management tools]
    RFIDREADER{{RFID reader}}
    USBLOCKD[usblockd]
    USBLOCKD_COMPAT_LAYER[usblockd-compat-layer]
    USBLOCK_STM{{STM32 USB}}
    MOTORLOCK{{Motor lock}}

    TUERDMANAGE -.- KEYREPO
    TUERD -.- KEYREPO

    RFIDREADER --> TUERD

    TUERD --> USBLOCKD_COMPAT_LAYER
    USBLOCKD_COMPAT_LAYER --> USBLOCKD
    USBLOCKD--> USBLOCK_STM
    USBLOCK_STM --> MOTORLOCK

Loading

tuerd management tools

The tuerd management tools (deploy and read_rfid) are used to provision new keys to the lock system. The deploy application connects to a LibNFC compatible device and provisions a blank Mifare DESFire EV1 (or EV2) by setting a generated PICC master key, creating an application with AID 0xca0523 on the RFID token with a generated master key and a generated door key.

It returns a JSON object containing those keys (and some other fields for later use). These information need to be stored in the Key Git Repository in a file with the name $(UPPERCASE_UID).json.

tuerd

The tuerd daemon connects to a LibNFC compatible reader and waits for a RFID token to be presented. If a Mifare DESFire EV1 (or newer) is presented to the reader, it takes the UID, checks for a corresponding JSON file in the Key Git Repository and loads it.

Then it checks the validity of the RFID token by checking the active property and then tries to authenticate against the RFID token against our application with AID 0xca0523 and using the door application key in the ca0523_door_key property. If everything succeeds, it will send an open command to the usblockd-compat-layer via UNIX socket.

usblockd-compat-layer

The usblockd-compat-layer decouples the tuerd from using signals to control the usblockd but using a (UNIX) socket and a defined command set. It is a temporary solution (ha, ha ha) to do additional stuff like controlling other motor locks not using the usblockd and it will be replaced/retired soon™️.

Command	Description
C	Close
O	Open
P	Powercycle

usblockd

The usblockd daemon and firmware is responsible for controlling a motor lock using USB and a STM32. It may be replaced/rewritten in the near future.

Compile

Dependencies:

• openssl (>= 1.1, <3.0)
• libnfc (>= 1.7.2)
• libfreefare (master, tested with commit c2b0cfa4b9fb0e4be88604f00b7a2405618d5abc)