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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def _read_encrypt_auth(self):
 """Read Authentication field when Cryptographic Authentication is employed. Structure of Cryptographic Authentication [RFC 2328]: 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 0 | Key ID | Auth Data Len | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Cryptographic sequence number | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Octets Bits Name Description 0 0 - Reserved (must be zero) 2 16 ospf.auth.key_id Key ID 3 24 ospf.auth.len Auth Data Length 4 32 ospf.auth.seq Cryptographic Sequence Number """

        _resv = self._read_fileng(2)
        _keys = self._read_unpack(1)
        _alen = self._read_unpack(1)
        _seqn = self._read_unpack(4)

        auth = dict(
            key_id=_keys,
            len=_alen,
            seq=_seqn,
        )

        return auth