Allowing providing a custom default ssl context function

src/aiovantage/connection.py

@@ -1,14 +1,28 @@
 """Wrapper for an asyncio connection to a Vantage controller."""
 
 import asyncio
+from collections.abc import Callable
 from ssl import CERT_NONE, SSLContext, create_default_context
+from typing import ClassVar
 
 from .errors import ClientConnectionError, ClientTimeoutError
 
 
+def _get_default_context() -> SSLContext:
+    """Create a default SSL context."""
+    # We don't have a local issuer certificate to check against, and we'll be
+    # connecting to an IP address so we can't check the hostname
+    ctx = create_default_context()
+    ctx.check_hostname = False
+    ctx.verify_mode = CERT_NONE
+    return ctx
+
+
 class BaseConnection:
     """Wrapper for an asyncio connection to a Vantage controller."""
 
+    ssl_context_factory: ClassVar[Callable[[], SSLContext]] = _get_default_context
+
     default_port: int
     default_ssl_port: int
     buffer_limit: int = 2**16
@@ -30,11 +44,7 @@ def __init__(
         # Set up the SSL context
         self._ssl: SSLContext | None
         if ssl is True:
-            # We don't have a local issuer certificate to check against, and we'll be
-            # connecting to an IP address so we can't check the hostname
-            self._ssl = create_default_context()
-            self._ssl.check_hostname = False
-            self._ssl.verify_mode = CERT_NONE
+            self._ssl = self.ssl_context_factory()
         elif isinstance(ssl, SSLContext):
             self._ssl = ssl
         else: