ENH: new Connection.ssl_protocol in pycaosdb.ini

src/caosdb/connection/connection.py

@@ -142,7 +142,11 @@ class _DefaultCaosDBServerConnection(CaosDBServerConnection):
             If no url has been specified, or if the CA certificate cannot be
             loaded.
         """
-        context = ssl.SSLContext(ssl.PROTOCOL_TLSv1)
+        if "ssl_version" in config and config["cacert"] is not None:
+            ssl_version = getattr(ssl, config["ssl_version"])
+        else:
+            ssl_version = ssl.PROTOCOL_TLSv1
+        context = ssl.SSLContext(ssl_version)
         context.verify_mode = ssl.CERT_REQUIRED
         if hasattr(context, "check_hostname"):
             context.check_hostname = True