Python AES Encryption decryption

AES encrypted block packet length must be 128 bits, the key length can be 128 bits, 192 bits, 256 bits of any one (if the data block and key length is insufficient, will be filled). AES encryption has many rounds of repetition and transformation. The approximate steps are as follows: 1, key expansion (keyexpansion), 2, initial wheel (Initial Round), 3, repeating wheel (Rounds), each round also includes: Subbytes, Shiftrows, Mixcolumns, AddRoundKey , 4, the final round (final Round), the final wheel is not mixcolumns.

AES's encryption and decryption methods are as follows, where password can only be 16,24 or 32-bit strings.

# encoding:utf-8from Crypto.cipher Import aesfrom Crypto import randomdef Encrypt (data, password):    bs = Aes.block_siz e    pad = lambda s:s + (bs-len (s)% BS) * CHR (Bs-len (s)% bs)    IV = Random.new (). Read (BS)    cipher = Aes.new (P Assword, AES. MODE_CBC, iv)    data = Cipher.encrypt (pad (data))    data = IV + data    return Datadef decrypt (data, password):    BS = Aes.block_size    If len (data) <= BS:        return data    Unpad = Lambda S:s[0:-ord (s[-1])]    IV = DATA[:BS ]    cipher = aes.new (password, AES. MODE_CBC, IV)    data  = Unpad (Cipher.decrypt (data[bs:]))    return data if __name__ = = ' __main__ ':d ata = ' Hello world ' password = ' 1111111111111111 ' #16, 24, 32-bit long password Encrypt_data = Encrypt (data, password) print ' Encrypt_data: ', Encrypt_datadecrypt_data = Decrypt (encrypt_data, password) print ' Decrypt_data: ', Decrypt_data

If you are prompted without crypto to cause execution to fail, you can use PIP install Pycrypto to install the appropriate module to resolve the issue.

The results of the implementation are as follows:

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Python AES Encryption decryption