| 0,0 → 1,68 |
|---|
| from blockcipher import * |
| from pyserpent import Serpent |
| |
| def new(key,mode=MODE_ECB,IV=None,counter=None,segment_size=None): |
| """Create a new cipher object |
| |
| Wrapper for pure python implementation pyserpent.py |
| |
| key = raw string containing the key |
| -> when using XTS mode: the key should be a tuple containing the 2 keys needed |
| mode = python_Serpent.MODE_ECB/CBC/CFB/OFB/CTR/XTS/CMAC, default is ECB |
| -> for every mode, except ECB and CTR, it is important to construct a seperate cipher for encryption and decryption |
| IV = IV as a raw string, default is "all zero" IV |
| -> needed for CBC, CFB and OFB mode |
| counter = counter object (CryptoPlus.Util.util.Counter) |
| -> only needed for CTR mode |
| -> use a seperate counter object for the cipher and decipher: the counter is updated directly, not a copy |
| see CTR example further on in the docstring |
| |
| EXAMPLES: |
| ********** |
| IMPORTING: |
| ----------- |
| >>> from CryptoPlus.Cipher import python_Serpent |
| |
| EXAMPLE: |
| --------- |
| NESSIE Test Vectors: http://www.cs.technion.ac.il/~biham/Reports/Serpent/Serpent-128-128.verified.test-vectors |
| |
| >>> cipher = python_Serpent.new(('000102030405060708090A0B0C0D0E0F').decode('hex')) |
| >>> (cipher.encrypt(('33B3DC87EDDD9B0F6A1F407D14919365').decode('hex'))).encode('hex').upper() |
| '00112233445566778899AABBCCDDEEFF' |
| >>> ( cipher.decrypt((_).decode('hex')) ).encode('hex').upper() |
| '33B3DC87EDDD9B0F6A1F407D14919365' |
| |
| >>> cipher = python_Serpent.new(('FDFDFDFDFDFDFDFDFDFDFDFDFDFDFDFD').decode('hex')) |
| >>> (cipher.encrypt(('FDFDFDFDFDFDFDFDFDFDFDFDFDFDFDFD').decode('hex'))).encode('hex').upper() |
| '81F9163BDF39B5BB2932AB91DF2A5FFC' |
| >>> ( cipher.decrypt((_).decode('hex')) ).encode('hex').upper() |
| 'FDFDFDFDFDFDFDFDFDFDFDFDFDFDFDFD' |
| |
| CBC EXAMPLE: |
| ------------- |
| >>> key = ('000102030405060708090A0B0C0D0E0F').decode('hex') |
| >>> IV = ('00000000000000000000000000000000').decode('hex') |
| >>> plaintext = ('33B3DC87EDDD9B0F6A1F407D14919365'*3).decode('hex') |
| >>> cipher = python_Serpent.new(key,python_Serpent.MODE_CBC,IV) |
| >>> ciphertext = cipher.encrypt(plaintext) |
| >>> decipher = python_Serpent.new(key,python_Serpent.MODE_CBC,IV) |
| >>> ( decipher.decrypt(ciphertext)).encode('hex').upper() |
| '33B3DC87EDDD9B0F6A1F407D1491936533B3DC87EDDD9B0F6A1F407D1491936533B3DC87EDDD9B0F6A1F407D14919365' |
| """ |
| return python_Serpent(key,mode,IV,counter,segment_size) |
| |
| class python_Serpent(BlockCipher): |
| def __init__(self,key,mode,IV,counter,segment_size): |
| if len(key) not in (16,24,32) and type(key) is not tuple: |
| raise ValueError("Key should be 128, 192 or 256 bits") |
| cipher_module = Serpent |
| self.blocksize = 16 |
| BlockCipher.__init__(self,key,mode,IV,counter,cipher_module,segment_size) |
| |
| def _test(): |
| import doctest |
| doctest.testmod() |
| |
| if __name__ == "__main__": |
| _test() |