'Returns the next section of the "random" Salsa20 bytes with the
requested `length`.'

def _get_salsa(self, length):

    while (length > len(self._salsa_buffer)):
        new_salsa = self.salsa.encryptBytes(str(bytearray(64)))
        self._salsa_buffer.extend(new_salsa)
    nacho = self._salsa_buffer[:length]
    del self._salsa_buffer[:length]
    return nacho
