Add DTLS handshake to recv_into

Author: JeremiahM37

wolfssl/__init__.py

@@ -676,6 +676,8 @@ def recv_into(self, buffer, nbytes=None, flags=0):
         self._check_closed("read")
         if self._context.protocol < PROTOCOL_DTLSv1:
             self._check_connected()
+        else:
+            self.do_handshake()
 
         if buffer is None:
             raise ValueError("buffer cannot be None")