ó õùPc@sˆdZdZddlmZddlmZdejfd„ƒYZd„ZdZd Z d Z d Z d Z d Z dZdZdZdS(s AES symmetric cipher AES `(Advanced Encryption Standard)`__ is a symmetric block cipher standardized by NIST_ . It has a fixed data block size of 16 bytes. Its keys can be 128, 192, or 256 bits long. AES is very fast and secure, and it is the de facto standard for symmetric encryption. As an example, encryption can be done as follows: >>> from Crypto.Cipher import AES >>> from Crypto import Random >>> >>> key = b'Sixteen byte key' >>> iv = Random.new().read(AES.block_size) >>> cipher = AES.new(key, AES.MODE_CFB, iv) >>> msg = iv + cipher.encrypt(b'Attack at dawn') .. __: http://en.wikipedia.org/wiki/Advanced_Encryption_Standard .. _NIST: http://csrc.nist.gov/publications/fips/fips197/fips-197.pdf :undocumented: __revision__, __package__ s$Id$iÿÿÿÿ(t blockalgo(t_AESt AESCiphercBseZdZd„ZRS(sAES cipher objectcOs tjj|t|||ŽdS(sVInitialize an AES cipher object See also `new()` at the module level.N(Rt BlockAlgot__init__R(tselftkeytargstkwargs((s,..\python\site-packages\Crypto\Cipher\AES.pyR7s(t__name__t __module__t__doc__R(((s,..\python\site-packages\Crypto\Cipher\AES.pyR4scOst|||ŽS(s}Create a new AES cipher :Parameters: key : byte string The secret key to use in the symmetric cipher. It must be 16 (*AES-128*), 24 (*AES-192*), or 32 (*AES-256*) bytes long. :Keywords: mode : a *MODE_** constant The chaining mode to use for encryption or decryption. Default is `MODE_ECB`. IV : byte string The initialization vector to use for encryption or decryption. It is ignored for `MODE_ECB` and `MODE_CTR`. For `MODE_OPENPGP`, IV must be `block_size` bytes long for encryption and `block_size` +2 bytes for decryption (in the latter case, it is actually the *encrypted* IV which was prefixed to the ciphertext). It is mandatory. For all other modes, it must be `block_size` bytes longs. It is optional and when not present it will be given a default value of all zeroes. counter : callable (*Only* `MODE_CTR`). A stateful function that returns the next *counter block*, which is a byte string of `block_size` bytes. For better performance, use `Crypto.Util.Counter`. 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 0 or not specified, it will be assumed to be 8. :Return: an `AESCipher` object (R(RRR((s,..\python\site-packages\Crypto\Cipher\AES.pytnew=s"iiiiiiiiii N(iii (R t __revision__t Crypto.CipherRRRRR tMODE_ECBtMODE_CBCtMODE_CFBtMODE_PGPtMODE_OFBtMODE_CTRt MODE_OPENPGPt block_sizetkey_size(((s,..\python\site-packages\Crypto\Cipher\AES.pyt-s %