Cannot connect to the DXFeed, SSL error

[perigvennetier]

Hi, I am digging a bit more in the code, which is a great learning experience. I am understanding what is going on but I come to a hiccup when the code tries to open the connection to the dxfeed in streamer.py but run into some sort of SSL issue.

MacOS BigSur 11.2.3
Python 3.9
PyCharm 2021.1

Traceback (most recent call last):
File "/Users/xxx/Documents/GitHub/tw-api/venv/lib/python3.9/site-packages/aiohttp/connector.py", line 969, in _wrap_create_connection
return await self._loop.create_connection(*args, **kwargs) # type: ignore # noqa
File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/asyncio/base_events.py", line 1081, in create_connection
transport, protocol = await self._create_connection_transport(
File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/asyncio/base_events.py", line 1111, in _create_connection_transport
await waiter
File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/asyncio/sslproto.py", line 528, in data_received
ssldata, appdata = self._sslpipe.feed_ssldata(data)
File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/asyncio/sslproto.py", line 188, in feed_ssldata
self._sslobj.do_handshake()
File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/ssl.py", line 944, in do_handshake
self._sslobj.do_handshake()
ssl.SSLCertVerificationError: [SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed: unable to get local issuer certificate (_ssl.c:1123)
The above exception was the direct cause of the following exception:
Traceback (most recent call last):
File "/Users/xxx/Documents/GitHub/tw-api/venv/lib/python3.9/site-packages/aiocometd/transports/websocket.py", line 170, in _send_final_payload
socket = await self._get_socket(headers)
File "/Users/xxx/Documents/GitHub/tw-api/venv/lib/python3.9/site-packages/aiocometd/transports/websocket.py", line 111, in _get_socket
return await self._socket_factory(
File "/Users/xxx/Documents/GitHub/tw-api/venv/lib/python3.9/site-packages/aiocometd/transports/websocket.py", line 63, in call
self._socket = await self._enter(*args, **kwargs)
File "/Users/xxx/Documents/GitHub/tw-api/venv/lib/python3.9/site-packages/aiocometd/transports/websocket.py", line 76, in _enter
return await self._context.aenter()
File "/Users/xxx/Documents/GitHub/tw-api/venv/lib/python3.9/site-packages/aiohttp/client.py", line 1117, in aenter
self._resp = await self._coro
File "/Users/xxx/Documents/GitHub/tw-api/venv/lib/python3.9/site-packages/aiohttp/client.py", line 754, in _ws_connect
resp = await self.request(
File "/Users/xxx/Documents/GitHub/tw-api/venv/lib/python3.9/site-packages/aiohttp/client.py", line 520, in _request
conn = await self._connector.connect(
File "/Users/xxx/Documents/GitHub/tw-api/venv/lib/python3.9/site-packages/aiohttp/connector.py", line 535, in connect
proto = await self._create_connection(req, traces, timeout)
File "/Users/xxx/Documents/GitHub/tw-api/venv/lib/python3.9/site-packages/aiohttp/connector.py", line 892, in _create_connection
_, proto = await self._create_direct_connection(req, traces, timeout)
File "/Users/xxx/Documents/GitHub/tw-api/venv/lib/python3.9/site-packages/aiohttp/connector.py", line 1051, in _create_direct_connection
raise last_exc
File "/Users/xxx/Documents/GitHub/tw-api/venv/lib/python3.9/site-packages/aiohttp/connector.py", line 1020, in _create_direct_connection
transp, proto = await self._wrap_create_connection(
File "/Users/xxx/Documents/GitHub/tw-api/venv/lib/python3.9/site-packages/aiohttp/connector.py", line 971, in _wrap_create_connection
raise ClientConnectorCertificateError(req.connection_key, exc) from exc
aiohttp.client_exceptions.ClientConnectorCertificateError: Cannot connect to host tasty-live-web.dxfeed.com:443 ssl:True [SSLCertVerificationError: (1, '[SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed: unable to get local issuer certificate (_ssl.c:1123)')]
The above exception was the direct cause of the following exception:
Traceback (most recent call last):
File "/Users/xxx/Documents/GitHub/tw-api/tastyworks/streamer.py", line 100, in _setup_connection
await cometd_client.open()
File "/Users/xxx/Documents/GitHub/tw-api/venv/lib/python3.9/site-packages/aiocometd/client.py", line 273, in open
self._transport = await self._negotiate_transport()
File "/Users/xxx/Documents/GitHub/tw-api/venv/lib/python3.9/site-packages/aiocometd/client.py", line 209, in _negotiate_transport
response = await transport.handshake(self._connection_types)
File "/Users/xxx/Documents/GitHub/tw-api/venv/lib/python3.9/site-packages/aiocometd/transports/base.py", line 250, in handshake
response_message = await self._send_message(
File "/Users/xxx/Documents/GitHub/tw-api/venv/lib/python3.9/site-packages/aiocometd/transports/base.py", line 303, in _send_message
return await self._send_payload_with_auth([message])
File "/Users/xxx/Documents/GitHub/tw-api/venv/lib/python3.9/site-packages/aiocometd/transports/base.py", line 318, in _send_payload_with_auth
response = await self._send_payload(payload)
File "/Users/xxx/Documents/GitHub/tw-api/venv/lib/python3.9/site-packages/aiocometd/transports/base.py", line 345, in _send_payload
return await self._send_final_payload(payload, headers=headers)
File "/Users/xxx/Documents/GitHub/tw-api/venv/lib/python3.9/site-packages/aiocometd/transports/websocket.py", line 185, in _send_final_payload
raise TransportError(str(error)) from error
aiocometd.exceptions.TransportError: Cannot connect to host tasty-live-web.dxfeed.com:443 ssl:True [SSLCertVerificationError: (1, '[SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed: unable to get local issuer certificate (_ssl.c:1123)')]

[perigvennetier]

So I found a solution online. Something to do with the certificate handled locally by Python.

Running this solved the issue:

/Applications/Python\ 3.9/Install\ Certificates.command

Output was:

-- pip install --upgrade certifi
Requirement already satisfied: certifi in /Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/site-packages (2020.12.5)
-- removing any existing file or link
-- creating symlink to certifi certificate bundle
-- setting permissions
-- update complete