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