open SOURCEFILE, '<', $file or die $!;  
  open DESTFILE, '>', "$file.$suffix" or die $!;
   $cipher->start($action);
    while ( read(SOURCEFILE, $buffer, $buffer_size) ) {
      $buffer = $cipher->crypt($buffer);
      syswrite(DESTFILE, $buffer, $buffer_size);
    }
   syswrite(DESTFILE, $cipher->finish, $buffer_size);
  close DESTFILE;
  close SOURCEFILE or die $!;