Detect blocking ssl context creation in the event loop (#123240)

homeassistant/block_async_io.py

@@ -8,6 +8,7 @@ import glob
 from http.client import HTTPConnection
 import importlib
 import os
+from ssl import SSLContext
 import sys
 import threading
 import time
@@ -143,6 +144,24 @@ _BLOCKING_CALLS: tuple[BlockingCall, ...] = (
         strict_core=False,
         skip_for_tests=True,
     ),
+    BlockingCall(
+        original_func=SSLContext.load_default_certs,
+        object=SSLContext,
+        function="load_default_certs",
+        check_allowed=None,
+        strict=False,
+        strict_core=False,
+        skip_for_tests=True,
+    ),
+    BlockingCall(
+        original_func=SSLContext.load_verify_locations,
+        object=SSLContext,
+        function="load_verify_locations",
+        check_allowed=None,
+        strict=False,
+        strict_core=False,
+        skip_for_tests=True,
+    ),
 )
 
 

tests/test_block_async_io.py

@@ -5,6 +5,7 @@ import glob
 import importlib
 import os
 from pathlib import Path, PurePosixPath
+import ssl
 import time
 from typing import Any
 from unittest.mock import Mock, patch
@@ -330,6 +331,29 @@ async def test_protect_loop_walk(
     assert "Detected blocking call to walk with args" not in caplog.text
 
 
+async def test_protect_loop_load_default_certs(
+    hass: HomeAssistant, caplog: pytest.LogCaptureFixture
+) -> None:
+    """Test SSLContext.load_default_certs calls in the loop are logged."""
+    with patch.object(block_async_io, "_IN_TESTS", False):
+        block_async_io.enable()
+    context = ssl.create_default_context()
+    assert "Detected blocking call to load_default_certs" in caplog.text
+    assert context
+
+
+async def test_protect_loop_load_verify_locations(
+    hass: HomeAssistant, caplog: pytest.LogCaptureFixture
+) -> None:
+    """Test SSLContext.load_verify_locations calls in the loop are logged."""
+    with patch.object(block_async_io, "_IN_TESTS", False):
+        block_async_io.enable()
+    context = ssl.create_default_context()
+    with pytest.raises(OSError):
+        context.load_verify_locations("/dev/null")
+    assert "Detected blocking call to load_verify_locations" in caplog.text
+
+
 async def test_open_calls_ignored_in_tests(caplog: pytest.LogCaptureFixture) -> None:
     """Test opening a file in tests is ignored."""
     assert block_async_io._IN_TESTS