finalize reader service

NfcReaderService.py

@@ -1,29 +1,34 @@
 import time
-import pyperclip
+from datetime import datetime, timedelta
 
 from smartcard.CardRequest import CardRequest
-from smartcard.Exceptions import CardConnectionException
+from smartcard.Exceptions import CardConnectionException, NoCardException
 from smartcard.CardConnection import CardConnection
 from smartcard.util import toHexString
 
+from pynput.keyboard import Controller
+
 from card_reader import read_card
 
-CLIPBOARD_MESSAGE_PREFIX = "ezgglan-clipboard-message:"
 
-
-class ClipboardReaderService:
+class NfcReaderService:
     def __init__(self) -> None:
         self._is_running = True
         self._last_uid = None
+        self._keyboard = Controller()
+        self._last_write = datetime(1900, 1, 1)
 
     def run(self) -> None:
         print("Reader ready.")
 
         while self._is_running:
             try:
+                time.sleep(0.1)
                 card_request = CardRequest(timeout=None)
+                print("Waiting for card...")
                 card_service = card_request.waitforcard()
                 connection = card_service.connection
+                print("Connected to card!")
 
                 try:
                     connection.connect(CardConnection.T1_protocol)
@@ -39,18 +44,19 @@ class ClipboardReaderService:
                     if uid_hex == self._last_uid:
                         connection.disconnect()
                         time.sleep(0.5)
+                        self._last_uid = None
                         continue
 
                     self._last_uid = uid_hex
 
                     user_id = read_card(connection)
-
                     if user_id is not None:
-                        pyperclip.copy(CLIPBOARD_MESSAGE_PREFIX + str(user_id))
-                    else:
-                        pyperclip.copy(CLIPBOARD_MESSAGE_PREFIX + "Fehler: Erneut scannen")
+                        now = datetime.now()
+                        if now - self._last_write > timedelta(seconds=2):
+                            self._keyboard.type(str(user_id))
+                            self._last_write = now
 
-                except CardConnectionException:
+                except (CardConnectionException, NoCardException):
                     pass
 
                 finally:
@@ -68,5 +74,5 @@ class ClipboardReaderService:
         self._is_running = False
 
 if __name__ == "__main__":
-    service = ClipboardReaderService()
+    service = NfcReaderService()
     service.run()

README.md

@@ -11,11 +11,12 @@ Currently supported NFC Device: ACR 1252U
   - Library: API for extracting user ID from card
 - card_writer
   - Standalone: Takes user ID as console input, writes it securely to card
-- ClipboardReaderService
-  - Standalone: Continuously reads cards and writes decrypted user ID or error message to clipboard
+- NfcReaderService
+  - Standalone: Continuously reads cards and writes decrypted user ID as keyboard output
 
 ## Intended usage
 
-Start `ClipboardReaderService` on terminals where LAN team needs to verify guest identity, EZGG LAN manager then reads user ID from clipboard.
+Start `NfcReaderService` on terminals where LAN team needs to verify guest identity, EZGG LAN manager then reads user ID from clipboard.
+`NfcReaderService` may be used as part of a systemd unit, to automate the startup process.
 
 Run `card_writer` when preparing tickets.

main.py

@@ -2,6 +2,9 @@ from smartcard.CardRequest import CardRequest
 from smartcard.util import toHexString
 from smartcard.CardConnection import CardConnection
 
+from card_writer import write_ndef_text
+
+
 def read_page(connection, page):
     apdu = [0xFF, 0xB0, 0x00, page, 0x04]
     data, sw1, sw2 = connection.transmit(apdu)

nfc-reader.service

@@ -0,0 +1,18 @@
+[Unit]
+Description=NFC Reader Service
+After=network.target
+
+[Service]
+Type=simple
+User=ezgg
+WorkingDirectory=/opt/nfc
+
+ExecStart=/opt/nfc/venv/bin/python /opt/nfc/NfcReaderService.py
+
+Restart=always
+RestartSec=2
+
+Environment=PYTHONUNBUFFERED=1
+
+[Install]
+WantedBy=multi-user.target

requirements.txt

@@ -1,6 +1,5 @@
 libusb1==3.3.1
 ndeflib==0.3.3
 pyDes==2.0.1
-pyperclip==1.11.0
 pyscard==2.3.1
 pyserial==3.5