def new(key, mode, *args, **kwargs): """Create a new Blowfish cipher :param key: The secret key to use in the symmetric cipher. Its length can vary from 5 to 56 bytes. :type key: bytes, bytearray, memoryview :param mode: The chaining mode to use for encryption or decryption. :type mode: One of the supported ``MODE_*`` constants :Keyword Arguments: * **iv** (*bytes*, *bytearray*, *memoryview*) -- (Only applicable for ``MODE_CBC``, ``MODE_CFB``, ``MODE_OFB``, and ``MODE_OPENPGP`` modes). The initialization vector to use for encryption or decryption. For ``MODE_CBC``, ``MODE_CFB``, and ``MODE_OFB`` it must be 8 bytes long. For ``MODE_OPENPGP`` mode only, it must be 8 bytes long for encryption and 10 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_EAX`` and ``MODE_CTR``). A value that must never be reused for any other encryption done with this key. For ``MODE_EAX`` there are no restrictions on its length (recommended: **16** bytes). For ``MODE_CTR``, its length must be in the range **[0..7]**. If not provided for ``MODE_EAX``, a random byte string is generated (you can read it back via the ``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``) Length of the authentication tag, in bytes. It must be no longer than 8 (default). * **initial_value** : (*integer*) -- (Only ``MODE_CTR``). The initial value for the counter within the counter block. By default it is **0**. :Return: a Blowfish object, of the applicable mode. """ return _create_cipher(sys.modules[__name__], key, mode, *args, **kwargs)
def new(key, mode, *args, **kwargs): """Create a new AES cipher. :param key: The secret key to use in the symmetric cipher. It must be 16, 24 or 32 bytes long (respectively for *AES-128*, *AES-192* or *AES-256*). For ``MODE_SIV`` only, it doubles to 32, 48, or 64 bytes. :type key: bytes/bytearray/memoryview :param mode: The chaining mode to use for encryption or decryption. If in doubt, use ``MODE_EAX``. :type mode: One of the supported ``MODE_*`` constants :Keyword Arguments: * **iv** (*bytes*, *bytearray*, *memoryview*) -- (Only applicable for ``MODE_CBC``, ``MODE_CFB``, ``MODE_OFB``, and ``MODE_OPENPGP`` modes). The initialization vector to use for encryption or decryption. For ``MODE_CBC``, ``MODE_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*) -- (Only ``MODE_CTR``). The initial value for the counter within the counter block. By default it is **0**. * **use_aesni** : (*boolean*) -- Use Intel AES-NI hardware extensions (default: use if available). :Return: an AES object, of the applicable mode. """ kwargs["add_aes_modes"] = True return _create_cipher(sys.modules[__name__], key, mode, *args, **kwargs)