src/CryptoPlus/Cipher/ARC2.py

   1 from blockcipher import *
   2 import Crypto.Cipher.ARC2
   3 import Crypto
   4 from pkg_resources import parse_version
   5
   6 def new(key,mode=MODE_ECB,IV=None,counter=None,effective_keylen=None,segment_size=None):
   7     """Create a new cipher object
   8
   9     ARC2 using pycrypto for algo and pycryptoplus for ciphermode
  10
  11         key = raw string containing the keys
  12         mode = python_AES.MODE_ECB/CBC/CFB/OFB/CTR/CMAC, default is ECB
  13         IV = IV as a raw string, default is "all zero" IV
  14             -> only needed for CBC mode
  15         counter = counter object (CryptoPlus.Util.util.Counter)
  16             -> only needed for CTR mode
  17         effective_keylen = how much bits to effectively use from the supplied key
  18             -> will only be used when the pycrypto version on your system is >2.0.1
  19
  20     EXAMPLES:
  21     **********
  22     IMPORTING:
  23     -----------
  24     >>> from CryptoPlus.Cipher import ARC2
  25
  26     http://www.ietf.org/rfc/rfc2268.txt
  27     Doctest will fail when using pycrypto 2.0.1 and older
  28     ------------------------------------
  29     >>> key = "0000000000000000".decode('hex')
  30     >>> plaintext = "0000000000000000".decode('hex')
  31     >>> ek = 63
  32     >>> cipher = ARC2.new(key,ARC2.MODE_ECB,effective_keylen=ek)
  33     >>> cipher.encrypt(plaintext).encode('hex')
  34     'ebb773f993278eff'
  35     """
  36     return ARC2(key,mode,IV,counter,effective_keylen,segment_size)
  37
  38 class ARC2(BlockCipher):
  39     def __init__(self,key,mode,IV,counter,effective_keylen,segment_size):
  40         # pycrypto versions newer than 2.0.1 will have support for "effective_keylen"
  41         if parse_version(Crypto.__version__) <= parse_version("2.0.1"):
  42             cipher_module = Crypto.Cipher.ARC2.new
  43             args = {}
  44         else:
  45             cipher_module = Crypto.Cipher.ARC2.new
  46             args = {'effective_keylen':effective_keylen}
  47         self.blocksize = 8
  48         BlockCipher.__init__(self,key,mode,IV,counter,cipher_module,segment_size,args)
  49
  50 def _test():
  51     import doctest
  52     doctest.testmod()
  53
  54 if __name__ == "__main__":
  55     _test()