0,0 → 1,58 |
from blockcipher import * |
try: |
import Crypto.Cipher.RC5 |
except ImportError: |
print "Crypto.Cipher.RC5 isn't available. You're probably using the Debian pycrypto version. Install the original pycrypto for RC5." |
raise |
|
def new(key,mode=MODE_ECB,IV=None,counter=None,segment_size=None,rounds=12,word_size=32): |
"""Create a new cipher object |
|
RC5 using pycrypto for algo and pycryptoplus for ciphermode |
|
key = raw string containing the keys |
multiple of 8 bits between 0 <-> 2040 bits |
mode = python_AES.MODE_ECB/CBC/CFB/OFB/CTR/CMAC, default is ECB |
IV = IV as a raw string, default is "all zero" IV |
-> only needed for CBC mode |
counter = counter object (CryptoPlus.Util.util.Counter) |
-> only needed for CTR mode |
segment_size = amount of bits to use from the keystream in each chain part |
-> supported values: multiple of 8 between 8 and the blocksize |
of the cipher (only per byte access possible), default is 8 |
-> only needed for CFB mode |
rounds = amount of rounds, default = 12 |
minimum 12 and multiple of 2 |
word_size = RC5 word size (bits), supported = 16 and 32, default = 32 |
RC5 encrypts blocks of size 2*word_size |
|
EXAMPLES: |
********** |
IMPORTING: |
----------- |
>>> from CryptoPlus.Cipher import RC5 |
|
https://www.cosic.esat.kuleuven.be/nessie/testvectors/ |
----------------------------------------- |
>>> key = "00000000000000000000000000000000".decode('hex') |
>>> plaintext = "0000000000000000".decode('hex') |
>>> rounds = 12 |
>>> cipher = RC5.new(key,RC5.MODE_ECB,rounds=rounds) |
>>> cipher.encrypt(plaintext).encode('hex') |
'21a5dbee154b8f6d' |
""" |
return RC5(key,mode,IV,counter,rounds,word_size,segment_size) |
|
class RC5(BlockCipher): |
def __init__(self,key,mode,IV,counter,rounds,word_size,segment_size): |
cipher_module = Crypto.Cipher.RC5.new |
args = {'rounds':rounds,'word_size':word_size} |
self.blocksize = (2*word_size)/8 |
BlockCipher.__init__(self,key,mode,IV,counter,cipher_module,segment_size,args) |
|
def _test(): |
import doctest |
doctest.testmod() |
|
if __name__ == "__main__": |
_test() |