Restore Plex recovery from a changed plex.direct certificate (#180446)

homeassistant/components/plex/server.py

@@ -191,8 +191,9 @@ class PlexServer:
                     error = error.__context__
                 if isinstance(error, ssl.SSLCertVerificationError):
                     domain = urlparse(self._url).netloc.split(":")[0]
-                    if domain.endswith("plex.direct") and error.args[0].startswith(
-                        f"hostname '{domain}' doesn't match"
+                    # OpenSSL's own wording for X509_V_ERR_HOSTNAME_MISMATCH
+                    if domain.endswith("plex.direct") and "Hostname mismatch" in str(
+                        error
                     ):
                         _LOGGER.warning(
                             "Plex SSL certificate's hostname changed, updating"

tests/components/plex/test_init.py

@@ -210,8 +210,11 @@ async def test_setup_when_certificate_changed(
         """Mock the exception showing a mismatched hostname."""
 
         def __init__(self) -> None:  # pylint: disable=super-init-not-called
+            # Shaped the way it is really raised: OSError args of (errno, message)
             self.__context__ = ssl.SSLCertVerificationError(
-                f"hostname '{old_domain}' doesn't match"
+                1,
+                "[SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed:"
+                f" Hostname mismatch, certificate is not valid for '{old_domain}'.",
             )
 
     old_domain = "1-2-3-4.1111111111ffffff1111111111ffffff.plex.direct"