Cipher/AES.py

   1 import blockcipher
   2 import Crypto.Cipher.AES
   3
   4 MODE_ECB = 1
   5 MODE_CBC = 2
   6 MODE_CFB = 3
   7 MODE_OFB = 5
   8 MODE_CTR = 6
   9
  10 def new(key,mode=blockcipher.MODE_ECB,IV=None):
  11         return AES(key,mode,IV)
  12
  13 class AES(blockcipher.BlockCipher):
  14         """AES using pycrypto for algo en pycryptoplus for ciphermode
  15
  16         EXAMPLE:
  17         ----------
  18         >>> import AES
  19         >>> cipher = AES.new('0123456789012345')
  20         >>> cipher.encrypt('0123456789012345')
  21         '_}\\xf0\\xbf\\x10:\\x8cJ\\xe6\\xfa\\xad\\x99\\x06\\xac;*'
  22         >>> cipher.decrypt(_)
  23         '0123456789012345'
  24
  25         CBC EXAMPLE (plaintext = 3 blocksizes):
  26         -----------------------------------------
  27         >>> from binascii import hexlify,unhexlify
  28         >>> import AES
  29         >>> key = unhexlify('2b7e151628aed2a6abf7158809cf4f3c')
  30         >>> IV = unhexlify('000102030405060708090a0b0c0d0e0f')
  31         >>> plaintext1 = unhexlify('6bc1bee22e409f96e93d7e117393172a')
  32         >>> plaintext2 = unhexlify('ae2d8a571e03ac9c9eb76fac45af8e51')
  33         >>> plaintext3 = unhexlify('30c81c46a35ce411e5fbc1191a0a52ef')
  34         >>> cipher = AES.new(key,AES.MODE_CBC,IV)
  35         >>> ciphertext = cipher.encrypt(plaintext1 + plaintext2 + plaintext3)
  36         >>> hexlify(ciphertext)
  37         '7649abac8119b246cee98e9b12e9197d5086cb9b507219ee95db113a917678b273bed6b8e3c1743b7116e69e22229516'
  38         >>> decipher = AES.new(key,AES.MODE_CBC,IV)
  39         >>> plaintext = decipher.decrypt(ciphertext)
  40         >>> hexlify(plaintext)
  41         '6bc1bee22e409f96e93d7e117393172aae2d8a571e03ac9c9eb76fac45af8e5130c81c46a35ce411e5fbc1191a0a52ef'
  42
  43         OR: supply plaintext as seperate pieces:
  44         ------------------------------------------
  45         >>> cipher = AES.new(key,AES.MODE_CBC,IV)
  46         >>> hexlify( cipher.encrypt(plaintext1 + plaintext2[:-2]) )
  47         '7649abac8119b246cee98e9b12e9197d'
  48         >>> hexlify( cipher.encrypt(plaintext2[-2:] + plaintext3) )
  49         '5086cb9b507219ee95db113a917678b273bed6b8e3c1743b7116e69e22229516'
  50         >>> decipher = AES.new(key,AES.MODE_CBC,IV)
  51         >>> hexlify(decipher.decrypt(ciphertext[:22]))
  52         '6bc1bee22e409f96e93d7e117393172a'
  53         >>> hexlify(decipher.decrypt(ciphertext[22:]))
  54         'ae2d8a571e03ac9c9eb76fac45af8e5130c81c46a35ce411e5fbc1191a0a52ef'
  55         """
  56         def __init__(self,key,mode,IV):
  57                 self.cipher = Crypto.Cipher.AES.new(key)
  58                 self.blocksize = Crypto.Cipher.AES.block_size
  59                 blockcipher.BlockCipher.__init__(self,key,mode,IV)
  60
  61 def _test():
  62         import doctest
  63         doctest.testmod()
  64
  65 if __name__ == "__main__":
  66         _test()