| 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() |