src/CryptoPlus/Cipher/python_DES3.py

   1 from blockcipher import *
   2 import pyDes
   3
   4 def new(key,mode=MODE_ECB,IV=None,counter=None,segment_size=None):
   5     """Create a DES-EDE3 or DES-EDE2 cipher object
   6
   7     wrapper for pure python 3DES implementation pyDes.py
   8
   9         key = raw string containing the 2/3 keys
  10             - DES-EDE2: supply 2 keys as 1 single concatenated 16byte key= key1|key2
  11             - DES-EDE3: supply 3 keys as 1 single concatenated 24byte key= key1|key2|key3
  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
  18     EXAMPLES:
  19     **********
  20     IMPORTING:
  21     -----------
  22     >>> from CryptoPlus.Cipher import python_DES3
  23
  24     CBC TDES-EDE3 EXAMPLE: (using test vectors from http://csrc.nist.gov/groups/STM/cavp/documents/des/DESMMT.pdf)
  25     ------------
  26     >>> key = ('37ae5ebf46dff2dc0754b94f31cbb3855e7fd36dc870bfae').decode('hex')
  27     >>> IV = ('3d1de3cc132e3b65').decode('hex')
  28     >>> cipher = python_DES3.new(key, python_DES3.MODE_CBC, IV)
  29     >>> ciphertext = cipher.encrypt(('84401f78fe6c10876d8ea23094ea5309').decode('hex'))
  30     >>> (ciphertext).encode('hex')
  31     '7b1f7c7e3b1c948ebd04a75ffba7d2f5'
  32     >>> decipher = python_DES3.new(key, python_DES3.MODE_CBC, IV)
  33     >>> plaintext = decipher.decrypt(ciphertext)
  34     >>> (plaintext).encode('hex')
  35     '84401f78fe6c10876d8ea23094ea5309'
  36
  37     CMAC TDES-EDE3 EXAMPLE:
  38     -------------
  39     testvector: http://csrc.nist.gov/publications/nistpubs/800-38B/Updated_CMAC_Examples.pdf
  40
  41     >>> key = '8aa83bf8cbda10620bc1bf19fbb6cd58bc313d4a371ca8b5'.decode('hex')
  42     >>> plaintext = '6bc1bee22e409f96e93d7e117393172aae2d8a57'.decode('hex')
  43     >>> cipher = python_DES3.new(key, python_DES3.MODE_CMAC)
  44     >>> cipher.encrypt(plaintext).encode('hex')
  45     '743ddbe0ce2dc2ed'
  46
  47     CMAC TDES-EDE2 EXAMPLE:
  48     -----------------------
  49     testvector: http://csrc.nist.gov/groups/STM/cavp/documents/mac/cmactestvectors.zip
  50
  51     >>> key1 = "5104f2c76180c1d3".decode('hex')
  52     >>> key2 = "b9df763e31ada716".decode('hex')
  53     >>> key = key1 + key2
  54     >>> plaintext = 'a6866be2fa6678f264a19c4474968e3f4eec24f5086d'.decode('hex')
  55     >>> cipher = python_DES3.new(key, python_DES3.MODE_CMAC)
  56     >>> cipher.encrypt(plaintext).encode('hex')
  57     '32e7758f3f614dbf'"""
  58     return python_DES3(key,mode,IV,counter,segment_size)
  59
  60 class python_DES3(BlockCipher):
  61     key_error_message = "Key should be 128 or 192 bits"
  62
  63     def __init__(self,key,mode,IV,counter,segment_size):
  64         cipher_module = pyDes.triple_des
  65         self.blocksize = 8
  66         BlockCipher.__init__(self,key,mode,IV,counter,cipher_module,segment_size)
  67
  68     def keylen_valid(self,key):
  69         return len(key) in (16,24)
  70
  71 def _test():
  72     import doctest
  73     doctest.testmod()
  74
  75 if __name__ == "__main__":
  76     _test()