Error: asyncio.exceptions.CancelledError

[HARIGB]

Hi,

I am using this OPC UA python Client to connect with my ignition scada opc ua server with SecurityPolicyBasic256Sha256 enclosing my code and detailed error message.

Code

import asyncio
import logging
import sys
sys.path.insert(0, "..")
from asyncua import Client, Node, ua
from asyncua.crypto.security_policies import SecurityPolicyBasic256Sha256

logging.basicConfig(level=logging.INFO)
_logger = logging.getLogger("asyncua")

cert_idx = 1
cert = "/root/py_factory/certificates/cookies_factory_my_cert.pem"
private_key = "/root/py_factory/certificates/cookies_factory_private_key.pem"


async def task(loop):
    url = "opc.tcp://localhost:62541/discovery"
    client = Client(url=url)
    await client.set_security(
        SecurityPolicyBasic256Sha256,
        certificate=cert,
        private_key=private_key,
        server_certificate="/root/py_factory/certificates/ignition-server.der"
    )
    async with client:
        objects = client.nodes.objects
        child = await objects.get_child(['0:MyObject', '0:MyVariable'])
        print(await child.get_value())
        await child.set_value(42)
        print(await child.get_value())


def main():
    loop = asyncio.get_event_loop()
    loop.set_debug(True)
    loop.run_until_complete(task(loop))
    loop.close()


if __name__ == "__main__":
    main()

Error Block

WARNING:asyncio:Executing <Task pending name='Task-1' coro=<task() running at /root/py_factory/opcua_asyncio.py:19> wait_for=<Future pending cb=[_chain_future.<locals>._call_check_cancel() at /usr/lib/python3.9/asyncio/futures.py:384, <TaskWakeupMethWrapper object at 0x7fa9bfaf3910>()] created at /usr/lib/python3.9/asyncio/base_events.py:424> cb=[_run_until_complete_cb() at /usr/lib/python3.9/asyncio/base_events.py:184] created at /usr/lib/python3.9/asyncio/base_events.py:621> took 0.185 seconds
INFO:asyncua.client.client:connect
INFO:asyncua.client.ua_client.UaClient:opening connection
INFO:asyncua.client.ua_client.UASocketProtocol:open_secure_channel
WARNING:asyncua.uaprotocol:Received an error: ErrorMessage(Error=StatusCode(value=2148728832), Reason='status=Bad_SecurityChecksFailed, description=An error occurred verifying security.')
CRITICAL:asyncua.client.ua_client.UASocketProtocol:Received an error: ErrorMessage(Error=StatusCode(value=2148728832), Reason='status=Bad_SecurityChecksFailed, description=An error occurred verifying security.')
ERROR:asyncua.client.ua_client.UASocketProtocol:Exception raised while parsing message from server
Traceback (most recent call last):
  File "/usr/local/lib/python3.9/dist-packages/asyncua/client/ua_client.py", line 167, in _call_callback
    self._callbackmap[request_id].set_result(body)
KeyError: 0

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "/usr/local/lib/python3.9/dist-packages/asyncua/client/ua_client.py", line 79, in _process_received_data
    self._process_received_message(msg)
  File "/usr/local/lib/python3.9/dist-packages/asyncua/client/ua_client.py", line 103, in _process_received_message
    self._call_callback(0, ua.UaStatusCodeError(msg.Error.value))
  File "/usr/local/lib/python3.9/dist-packages/asyncua/client/ua_client.py", line 169, in _call_callback
    raise ua.UaError(f"No request found for request id: {request_id}, pending are {self._callbackmap.keys()}, body was {body}") from ex
asyncua.ua.uaerrors._base.UaError: No request found for request id: 0, pending are dict_keys([1]), body was "An error occurred verifying security."(BadSecurityChecksFailed)
INFO:asyncua.client.ua_client.UASocketProtocol:Request to close socket received
INFO:asyncua.client.ua_client.UASocketProtocol:Socket has closed connection
WARNING:asyncua.client.ua_client.UaClient:disconnect_socket was called but connection is closed
Traceback (most recent call last):
  File "/usr/lib/python3.9/asyncio/tasks.py", line 492, in wait_for
    fut.result()
asyncio.exceptions.CancelledError

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "/root/py_factory/opcua_asyncio.py", line 41, in <module>
    main()
  File "/root/py_factory/opcua_asyncio.py", line 36, in main
    loop.run_until_complete(task(loop))
  File "/usr/lib/python3.9/asyncio/base_events.py", line 642, in run_until_complete
    return future.result()
  File "/root/py_factory/opcua_asyncio.py", line 25, in task
    async with client:
  File "/usr/local/lib/python3.9/dist-packages/asyncua/client/client.py", line 69, in __aenter__
    await self.connect()
  File "/usr/local/lib/python3.9/dist-packages/asyncua/client/client.py", line 255, in connect
    await self.open_secure_channel()
  File "/usr/local/lib/python3.9/dist-packages/asyncua/client/client.py", line 306, in open_secure_channel
    result = await self.uaclient.open_secure_channel(params)
  File "/usr/local/lib/python3.9/dist-packages/asyncua/client/ua_client.py", line 280, in open_secure_channel
    return await self.protocol.open_secure_channel(params)
  File "/usr/local/lib/python3.9/dist-packages/asyncua/client/ua_client.py", line 213, in open_secure_channel
    await asyncio.wait_for(self._send_request(request, message_type=ua.MessageType.SecureOpen), self.timeout)
  File "/usr/lib/python3.9/asyncio/tasks.py", line 494, in wait_for
    raise exceptions.TimeoutError() from exc
asyncio.exceptions.TimeoutError

Any insight on this error would be greatly appreciated!

Thanks,
Hari GB.