E_CFB``, and ``MODE_OFB`` it must be 16 bytes long.

    For ``MODE_OPENPGP`` mode only,
    it must be 16 bytes long for encryption
    and 18 bytes for decryption (in the latter case, it is
    actually the *encrypted* IV which was prefixed to the ciphertext).

    If not provided, a random byte string is generated (you must then
    read its value with the :attr:`iv` attribute).

  nonce (bytes/bytearray/memoryview):
    (Only applicable for ``MODE_CCM``, ``MODE_EAX``, ``MODE_GCM``,
    ``MODE_SIV``, ``MODE_OCB``, and ``MODE_CTR``).

    A value that must never be reused for any other encryption done
    with this key (except possibly for ``MODE_SIV``, see below).

    For ``MODE_EAX``, ``MODE_GCM`` and ``MODE_SIV`` there are no
    restrictions on its length (recommended: **16** bytes).

    For ``MODE_CCM``, its length must be in the range **[7..13]**.
    Bear in mind that with CCM there is a trade-off between nonce
    length and maximum message size. Recommendation: **11** bytes.

    For ``MODE_OCB``, its length must be in the range **[1..15]**
    (recommended: **15**).

    For ``MODE_CTR``, its length must be in the range **[0..15]**
    (recommended: **8**).

    For ``MODE_SIV``, the nonce is optional, if it is not specified,
    then no nonce is being used, which renders the encryption
    deterministic.

    If not provided, for modes other than ``MODE_SIV``, a random
    byte string of the recommended length is used (you must then
    read its value with the :attr:`nonce` attribute).

  segment_size (integer):
    (Only ``MODE_CFB``).The number of **bits** the plaintext and ciphertext
    are segmented in. It must be a multiple of 8.
    If not specified, it will be assumed to be 8.

  mac_len (integer):
    (Only ``MODE_EAX``, ``MODE_GCM``, ``MODE_OCB``, ``MODE_CCM``)
    Length of the authentication tag, in bytes.

    It must be even and in the range **[4..16]**.
    The recommended value (and the default, if not specified) is **16**.

  msg_len (integer):
    (Only ``MODE_CCM``). Length of the message to (de)cipher.
    If not specified, ``encrypt`` must be called with the entire message.
    Similarly, ``decrypt`` can only be called once.

  assoc_len (integer):
    (Only ``MODE_CCM``). Length of the associated data.
    If not specified, all associated data is buffered internally,
    which may represent a problem for very large messages.

  initial_value (integer or bytes/bytearray/memoryview):
    (Only ``MODE_CTR``).
    The initial value for the counter. If not present, the cipher will
    start counting from 0. The value is incremented by one for each block.
    The counter number is encoded in big endian mode.

  counter (object):
    (Only ``MODE_CTR``).
    Instance of ``Cryptodome.Util.Counter``, which allows full customization
    of the counter block. This parameter is incompatible to both ``nonce``
    and ``initial_value``.

  use_aesni: (boolean):
    Use Intel AES-NI hardware extensions (default: use if available).

Returns:
    an AES object, of the applicable mode.
TÚ
add_aes_modes)