WIP: initial step towards websocket-based remote card [reader] access

Change-Id: I588bf4b3d9891766dd688a6818057ca20fb26e3f

contrib/wsrc_card_client.py

@@ -0,0 +1,112 @@
+#!/usr/bin/env python3
+
+"""Connect smartcard to a remote server, so the remote server can take control and
+perform commands on it."""
+
+import sys
+import json
+import logging
+import argparse
+from osmocom.utils import b2h
+import websockets
+
+from pySim.transport import init_reader, argparse_add_reader_args, LinkBase
+from pySim.commands import SimCardCommands
+from pySim.wsrc.client_blocking import WsClientBlocking
+from pySim.exceptions import NoCardError
+from pySim.wsrc import WSRC_DEFAULT_PORT_CARD
+
+logging.basicConfig(format="[%(levelname)s] %(asctime)s %(message)s", level=logging.INFO)
+logger = logging.getLogger(__name__)
+
+class CardWsClientBlocking(WsClientBlocking):
+    """Implementation of the card (reader) client of the WSRC (WebSocket Remote Card) protocol"""
+
+    def __init__(self, ws_uri, tp: LinkBase):
+        super().__init__('card', ws_uri)
+        self.tp = tp
+
+    def perform_outbound_hello(self):
+        hello_data = {
+            'atr': b2h(self.tp.get_atr()),
+            # TODO: include various card information in the HELLO message
+        }
+        super().perform_outbound_hello(hello_data)
+
+    def handle_rx_c_apdu(self, rx: dict):
+        """handle an inbound APDU transceive command"""
+        data, sw = self.tp.send_apdu(rx['command'])
+        tx = {
+            'response': data,
+            'sw': sw,
+        }
+        self.tx_json('r_apdu', tx)
+
+    def handle_rx_disconnect(self, rx: dict):
+        """server tells us to disconnect"""
+        self.tx_json('disconnect_ack')
+        # FIXME: tear down connection and/or terminate entire program
+
+    def handle_rx_state_notification(self, rx: dict):
+        logger.info("State Notification: %s" % rx['new_state'])
+
+    def handle_rx_print(self, rx: dict):
+        """print a message (text) given by server to the local console/log"""
+        logger.info("SERVER MSG: %s" % rx['message'])
+        # no response
+
+    def handle_rx_reset_req(self, rx: dict):
+        """server tells us to reset the card"""
+        self.tp.reset_card()
+        self.tx_json('reset_resp', {'atr': b2h(self.tp.get_atr())})
+
+
+parser = argparse.ArgumentParser()
+argparse_add_reader_args(parser)
+parser.add_argument("--uri", default="ws://localhost:%u/" % (WSRC_DEFAULT_PORT_CARD),
+                    help="URI of the sever to which to connect")
+
+
+if __name__ == '__main__':
+    opts = parser.parse_args()
+
+    # open the card reader / slot
+    logger.info("Initializing Card Reader...")
+    try:
+        tp = init_reader(opts)
+    except Exception as e:
+        logger.fatal("Error opening reader: %s" % e)
+        sys.exit(1)
+
+    logger.info("Connecting to Card...")
+    try:
+        tp.connect()
+    except NoCardError as e:
+        logger.fatal("Error opening card! Is a card inserted in the reader?")
+        sys.exit(1)
+
+    scc = SimCardCommands(transport=tp)
+    logger.info("Detected Card with ATR: %s" % b2h(tp.get_atr()))
+
+    # TODO: gather various information about the card; print it
+
+    # create + connect the client to the server
+    cl = CardWsClientBlocking(opts.uri, tp)
+    logger.info("Connecting to remote server...")
+    try:
+        cl.connect()
+        logger.info("Successfully connected to Server")
+    except ConnectionRefusedError as e:
+        logger.fatal(e)
+        sys.exit(1)
+
+    try:
+        while True:
+            # endless loop: wait for inbound command from server + execute it
+            cl.rx_and_execute_cmd()
+    except websockets.exceptions.ConnectionClosedOK as e:
+        print(e)
+        sys.exit(1)
+    except KeyboardInterrupt as e:
+        print(e.__class__.__name__)
+        sys.exit(2)