--- ssl.py.orig	2020-08-07 17:18:47.979040464 +0900
+++ ssl.py	2020-08-20 10:44:27.143001000 +0900
@@ -174,7 +174,8 @@
 import base64        # for DER-to-PEM translation
 import errno
 import warnings
-
+# bugfix: SSLError sslv3 alert bad record mac
+import threading
 
 socket_error = OSError  # keep that public name in module namespace
 
@@ -659,6 +660,8 @@
             owner=self, session=session
         )
         self._sslobj = sslobj
+        # bugfix: SSLError sslv3 alert bad record mac
+        self._read_write_sync = threading.Lock()
         return self
 
     @property
@@ -701,11 +704,13 @@
         If 'buffer' is provided, read into this buffer and return the number of
         bytes read.
         """
-        if buffer is not None:
-            v = self._sslobj.read(len, buffer)
-        else:
-            v = self._sslobj.read(len)
-        return v
+        # bugfix: SSLError sslv3 alert bad record mac
+        with self._read_write_sync:
+            if buffer is not None:
+                v = self._sslobj.read(len, buffer)
+            else:
+                v = self._sslobj.read(len)
+            return v
 
     def write(self, data):
         """Write 'data' to the SSL object and return the number of bytes
@@ -713,7 +718,9 @@
 
         The 'data' argument must support the buffer interface.
         """
-        return self._sslobj.write(data)
+        # bugfix: SSLError sslv3 alert bad record mac
+        with self._read_write_sync:
+            return self._sslobj.write(data)
 
     def getpeercert(self, binary_form=False):
         """Returns a formatted version of the data in the certificate provided