python DES暗号化アルゴリズムの実装


pythonを初めて勉強して、サイバーセキュリティの授業の宿題-DESを書きました.れんがを撮るのを歓迎します~
ps.テスト駆動開発を試してみると、ちょっと慣れていませんね...
 
コードには2つのセグメントがあり、前は実装、後はテストフレームワークです.どうしてテストコードばかり言っているのか、私は何も言わなかった.
 
#coding=utf-8
from functools import partial

class DES(object):
    """
    DES    
    interface: input_key(s, base=10), encode(s), decode(s)
    """
    __ip = [
        58,50,42,34,26,18,10,2,60,52,44,36,28,20,12,4,
        62,54,46,38,30,22,14,6,64,56,48,40,32,24,16,8,
        57,49,41,33,25,17, 9,1,59,51,43,35,27,19,11,3,
        61,53,45,37,29,21,13,5,63,55,47,39,31,23,15,7,
    ]
    __ip1 = [
        40,8,48,16,56,24,64,32,39,7,47,15,55,23,63,31,
        38,6,46,14,54,22,62,30,37,5,45,13,53,21,61,29,
        36,4,44,12,52,20,60,28,35,3,43,11,51,19,59,27,
        34,2,42,10,50,18,58,26,33,1,41, 9,49,17,57,25,
    ]
    __e = [
        32, 1, 2, 3, 4, 5,
        4 , 5, 6, 7, 8, 9,
        8 , 9,10,11,12,13,
        12,13,14,15,16,17,
        16,17,18,19,20,21,
        20,21,22,23,24,25,
        24,25,26,27,28,29,
        28,29,30,31,32, 1,
    ]
    __p = [
        16, 7,20,21,29,12,28,17,
        1 ,15,23,26, 5,18,31,10,
        2 ,8 ,24,14,32,27, 3, 9,
        19,13,30, 6,22,11, 4,25,
    ]
    __s = [
        [
        0xe,0x4,0xd,0x1,0x2,0xf,0xb,0x8,0x3,0xa,0x6,0xc,0x5,0x9,0x0,0x7,
        0x0,0xf,0x7,0x4,0xe,0x2,0xd,0x1,0xa,0x6,0xc,0xb,0x9,0x5,0x3,0x8,
        0x4,0x1,0xe,0x8,0xd,0x6,0x2,0xb,0xf,0xc,0x9,0x7,0x3,0xa,0x5,0x0,
        0xf,0xc,0x8,0x2,0x4,0x9,0x1,0x7,0x5,0xb,0x3,0xe,0xa,0x0,0x6,0xd,
        ],
        [
        0xf,0x1,0x8,0xe,0x6,0xb,0x3,0x4,0x9,0x7,0x2,0xd,0xc,0x0,0x5,0xa,
        0x3,0xd,0x4,0x7,0xf,0x2,0x8,0xe,0xc,0x0,0x1,0xa,0x6,0x9,0xb,0x5,
        0x0,0xe,0x7,0xb,0xa,0x4,0xd,0x1,0x5,0x8,0xc,0x6,0x9,0x3,0x2,0xf,
        0xd,0x8,0xa,0x1,0x3,0xf,0x4,0x2,0xb,0x6,0x7,0xc,0x0,0x5,0xe,0x9,
        ],
        [
        0xa,0x0,0x9,0xe,0x6,0x3,0xf,0x5,0x1,0xd,0xc,0x7,0xb,0x4,0x2,0x8,
        0xd,0x7,0x0,0x9,0x3,0x4,0x6,0xa,0x2,0x8,0x5,0xe,0xc,0xb,0xf,0x1,
        0xd,0x6,0x4,0x9,0x8,0xf,0x3,0x0,0xb,0x1,0x2,0xc,0x5,0xa,0xe,0x7,
        0x1,0xa,0xd,0x0,0x6,0x9,0x8,0x7,0x4,0xf,0xe,0x3,0xb,0x5,0x2,0xc,
        ],
        [
        0x7,0xd,0xe,0x3,0x0,0x6,0x9,0xa,0x1,0x2,0x8,0x5,0xb,0xc,0x4,0xf,
        0xd,0x8,0xb,0x5,0x6,0xf,0x0,0x3,0x4,0x7,0x2,0xc,0x1,0xa,0xe,0x9,
        0xa,0x6,0x9,0x0,0xc,0xb,0x7,0xd,0xf,0x1,0x3,0xe,0x5,0x2,0x8,0x4,
        0x3,0xf,0x0,0x6,0xa,0x1,0xd,0x8,0x9,0x4,0x5,0xb,0xc,0x7,0x2,0xe,
        ],
        [
        0x2,0xc,0x4,0x1,0x7,0xa,0xb,0x6,0x8,0x5,0x3,0xf,0xd,0x0,0xe,0x9,
        0xe,0xb,0x2,0xc,0x4,0x7,0xd,0x1,0x5,0x0,0xf,0xa,0x3,0x9,0x8,0x6,
        0x4,0x2,0x1,0xb,0xa,0xd,0x7,0x8,0xf,0x9,0xc,0x5,0x6,0x3,0x0,0xe,
        0xb,0x8,0xc,0x7,0x1,0xe,0x2,0xd,0x6,0xf,0x0,0x9,0xa,0x4,0x5,0x3,
        ],
        [
        0xc,0x1,0xa,0xf,0x9,0x2,0x6,0x8,0x0,0xd,0x3,0x4,0xe,0x7,0x5,0xb,
        0xa,0xf,0x4,0x2,0x7,0xc,0x9,0x5,0x6,0x1,0xd,0xe,0x0,0xb,0x3,0x8,
        0x9,0xe,0xf,0x5,0x2,0x8,0xc,0x3,0x7,0x0,0x4,0xa,0x1,0xd,0xb,0x6,
        0x4,0x3,0x2,0xc,0x9,0x5,0xf,0xa,0xb,0xe,0x1,0x7,0x6,0x0,0x8,0xd,
        ],
        [
        0x4,0xb,0x2,0xe,0xf,0x0,0x8,0xd,0x3,0xc,0x9,0x7,0x5,0xa,0x6,0x1,
        0xd,0x0,0xb,0x7,0x4,0x9,0x1,0xa,0xe,0x3,0x5,0xc,0x2,0xf,0x8,0x6,
        0x1,0x4,0xb,0xd,0xc,0x3,0x7,0xe,0xa,0xf,0x6,0x8,0x0,0x5,0x9,0x2,
        0x6,0xb,0xd,0x8,0x1,0x4,0xa,0x7,0x9,0x5,0x0,0xf,0xe,0x2,0x3,0xc,
        ],
        [
        0xd,0x2,0x8,0x4,0x6,0xf,0xb,0x1,0xa,0x9,0x3,0xe,0x5,0x0,0xc,0x7,
        0x1,0xf,0xd,0x8,0xa,0x3,0x7,0x4,0xc,0x5,0x6,0xb,0x0,0xe,0x9,0x2,
        0x7,0xb,0x4,0x1,0x9,0xc,0xe,0x2,0x0,0x6,0xa,0xd,0xf,0x3,0x5,0x8,
        0x2,0x1,0xe,0x7,0x4,0xa,0x8,0xd,0xf,0xc,0x9,0x0,0x3,0x5,0x6,0xb,
        ],
    ]
    __k1 = [
        57,49,41,33,25,17, 9,
        1 ,58,50,42,34,26,18,
        10, 2,59,51,43,35,27,
        19,11, 3,60,52,44,36,
        63,55,47,39,31,23,15,
        7 ,62,54,46,38,30,22,
        14, 6,61,53,45,37,29,
        21,13, 5,28,20,12, 4,
    ]
    __k2 = [
        14,17,11,24, 1, 5, 3,28,
        15, 6,21,10,23,19,12, 4,
        26, 8,16, 7,27,20,13, 2,
        41,52,31,37,47,55,30,40,
        51,45,33,48,44,49,39,56,
        34,53,46,42,50,36,29,32,
    ]
    __k0 = [
        1,1,2,2,2,2,2,2,1,2,2,2,2,2,2,1,
    ]
    __hex_bin = {
        '0':'0000','1':'0001','2':'0010','3':'0011',
        '4':'0100','5':'0101','6':'0110','7':'0111',
        '8':'1000','9':'1001','a':'1010','b':'1011',
        'c':'1100','d':'1101','e':'1110','f':'1111',
        ' ':'0000'
    }

    __re = lambda t, s: ''.join(s[i-1] for i in t)

    __IP = partial(__re, __ip)
    __IP1 = partial(__re, __ip1)
    __E = partial(__re, __e)
    __P = partial(__re, __p)
    __K1 = partial(__re, __k1)
    __K2 = partial(__re, __k2)

    __B = partial( lambda hex_bin, s: ''.join(hex_bin[w]
        for w in ''.join('%2x' % ord(w) for w in s))
        , __hex_bin)
    __DB = partial( lambda s: ''.join(chr(int(s[i:i+8], 2)) for i in range(0, len(s), 8)))
    __S = partial( lambda hex_bin, __s, s: ''.join(hex_bin['%x' % __s[i][
        int(s[i*6]+s[i*6+5], 2)*16 + int(s[i*6+1:i*6+5], 2)]] for i in range(8))
        , __hex_bin, __s)
    __F = partial( lambda s, k: ''.join('0' if s[i]==k[i] else '1' for i in range(len(s))))
    __K0 = partial( lambda k0, K2, k: map(K2,
        (k[k0[i]:28]+k[0:k0[i]] + k[k0[i]+28:56]+k[28:k0[i]+28] for i in range(16)))
        , __k0, __K2)
    __K = partial( lambda K1, K0, k: K0(K1(k))
        , __K1, __K0)

    def __init__(self):
        pass

    def input_key(self, key, base=10):
        if base == 2:
            pass
        elif base == 16:
            key = ''.join(self.__class__.__hex_bin[w] for w in key)
        else:
            key = self.__class__.__B(key)
        self.__k = self.__class__.__K(key)

    def __code(self, s, k):
        s = self.__IP(s)
        l, r = s[0:32], s[32:64]
        for i in range(16):
            r_t = r
            r = self.__E(r)
            r = self.__F(r, k[i])
            r = self.__S(r)
            r = self.__P(r)
            r = self.__F(r, l)
            l = r_t
        return self.__class__.__IP1(r+l)

    def encode(self, s):
        a = ''
        s += ' ' * ((8-len(s)%8)%8)
        for i in range(0, len(s), 8):
            before = self.__class__.__B(s[i:i+8])
            after = self.__code(before, self.__k)
            a += '%16x' % int(after, 2)
        return ''.join(w if w!=' ' else '0' for w in a)

    def decode(self, s):
        a = ''
        s.lower()
        for i in range(0, len(s), 16):
            before = ''.join(self.__class__.__hex_bin[s[j]] for j in range(i, i+16))
            after = self.__code(before, self.__k[::-1])
            a += self.__class__.__DB(after)
        return a.rstrip()


if __name__ == '__main__':
    d = DES()
    d.input_key('  8 !')
    s = '    
' a = d.encode(s) print a b = d.decode(a) print b
 
#coding=utf-8
import unittest
from des import DES

class KnownValues(unittest.TestCase):
    """"""
    __known_values = (('12345678','ABC    ','388a9c61849462e20af277ffe6891072'),
            )

    def test_encode(self):
        des = DES()
        for key, before, after in self.__known_values:
            des.input_key(key)
            result = des.encode(before)
            self.assertEqual(after, result)

    def test_decode(self):
        des = DES()
        for key, after, before in self.__known_values:
            des.input_key(key)
            result = des.decode(before)
            self.assertEqual(after, result)

class BadInput(unittest.TestCase):
    """"""
    __key_inputs = (
            )
    def test_input_key(self):
        des = DES()
        self.assertRaises(IndexError, des.input_key, '1234567', 10)
        self.assertRaises(IndexError, des.input_key, '123  , 4567', 2)
        self.assertRaises(KeyError, des.input_key, '123    , 4567', 16)

    def test_encode(self):
        pass

    def test_decode(self):
        des = DES()
        self.assertRaises(KeyError, des.decode, '123    , 4567')

class SanityCheck(unittest.TestCase):
    """"""
    """"""
    __encode_inputs = (('asfd  ','  sa1'),
            )
    __decode_inputs = (('12345678','388a9c61849462e20af277ffe6891072'),
            )

    def test_encode(self):
        des = DES()
        for key, before in self.__encode_inputs:
            des.input_key(key)
            after = des.encode(before)
            result = des.decode(after)
            self.assertEqual(before, result)

    def test_decode(self):
        des = DES()
        for key, before in self.__decode_inputs:
            des.input_key(key)
            after = des.decode(before)
            result = des.encode(after)
            self.assertEqual(before, result)

if __name__ == '__main__':
    unittest.main()