This does not make sense because core_async should not depend on home assistant. If in the future this will be implemented as a separate library, cannot have this dependencies.
There is already a way to directly use the aiohttp session created in ha, probably the best solution is to use this as default option (at this moment is available as advanced option during initial configuration)
To implement this in the library in not blocking way we should implement the ha get_default_context and not import the HA method.

I checked the implementation of get_default_context in homeassistant.util.ssl and I couldn't see any significant difference with what the current ha-smartthinq-sensors code is doing 🤔
Maybe the @cache decorator helps somehow?

It could be, you should check what @cache decorator do...

I checked. It basically adds a thin wrapper to cache the responses if there is another call to the same function with the same parameters https://docs.python.org/3/library/functools.html#functools.cache
but you are kind of doing that already with _get_session()

Looks like HA is not complaining about using ssl.create_default_context(), it's complaining about where it's being used. Unless the session can be created somewhere else outside of the event loop and then re-used here it's going be complicated.

Also, about this PR... isn't it changing the SSL ciphers of the default context for all HA? Isn't that risky?

Do we still need the _LG_SSL_CIPHERS ? Maybe they updated the servers and the defaults work now

There is no cipher set in get_default_context so that part should be the same.

Yes, the warning can be resolved by creating the context outside the event loop but I don't think that can be done in the life cycle of an integration initialization and without referencing ha.

This will mutate the default ssl context

The simplest fix would be to create the context and store it in a constant so it doesn't happen at run time, and instead at import time which will run in the executor

something like

diff --git a/custom_components/smartthinq_sensors/wideq/core_async.py b/custom_components/smartthinq_sensors/wideq/core_async.py
index 9335180..ec908ed 100644
--- a/custom_components/smartthinq_sensors/wideq/core_async.py
+++ b/custom_components/smartthinq_sensors/wideq/core_async.py
@@ -143,13 +143,18 @@ def _oauth_info_from_result(result_info: dict) -> dict:
 
     return result
 
+def _create_lg_ssl_context() -> ssl.SSLContext:
+    """Create a SSL context for LG ThinQ."""
+    context = ssl.create_default_context()
+    context.set_ciphers(_LG_SSL_CIPHERS)
+    return context
+
+_SSL_CONTEXT = _create_lg_ssl_context()
 
 def lg_client_session() -> aiohttp.ClientSession:
     """Create an aiohttp client session to use with LG ThinQ."""
-    context = ssl.create_default_context()
-    context.set_ciphers(_LG_SSL_CIPHERS)
     connector = aiohttp.TCPConnector(
-        enable_cleanup_closed=ENABLE_CLEANUP_CLOSED, ssl_context=context
+        enable_cleanup_closed=ENABLE_CLEANUP_CLOSED, ssl_context=_SSL_CONTEXT
     )
     return aiohttp.ClientSession(connector=connector)
 

Thanks!!!

Adjusted as suggested, yes this works without any warnings.

Thanks @iprak 👍

I'm far from home for work this month, I will work to merge this PR and prepare next release probably by the end of next week.