The API documentation already implies that write might not write the entire buffer because it returns the number of bytes actually written (just like os.write).  

A possible workaround on the SSL layer is hence to clamp the amount of bytes to write to MAX_INT (or later MAX_SSIZE_T) bytes. 

That said, this does require checking that users of the SSL layer write method in the stdib actually check for the number of bytes written, otherwise we'd exchange the exception to a silent error.