py.py

def sbox(binary):
    # assert len(binary)=8 hz kak
    i = int(binary[0]+binary[5], 2)  # v1 vector
    j = int(binary[1:5], 2)  # v2 vector
    sbox_table = \
        ((14, 4, 13, 1, 2, 15, 11, 8, 3, 10, 6, 12, 5, 9, 0, 7),
         (0, 15, 7, 4, 14, 2, 13, 1, 10, 6, 12, 11, 9, 5, 3, 8),
         (4, 1, 14, 8, 13, 6, 2, 11, 15, 12, 9, 7, 3, 10, 5, 0),
         (15, 12, 8, 2, 4, 9, 1, 7, 5, 11, 3, 14, 10, 0, 6, 13))

    return(sbox_table[i][j])

def chunks(l, n):
    """ Yield successive n-sized chunks from l.
    """
    for i in range(0, len(l), n):
        yield l[i:i+n]

def des_encrypt(text, key, rounds=1):
    text_ascii = [bin(ord(c) % 848) for c in text]
    key = list(chunks(key, 6))
    # таблица перестановок
    perm = [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]

    text_ascii = ''.join([str(e) for e in text_ascii])
    print('исходный текст в бинарном формате (ascii) ', text_ascii)
    text_permutated = list()
    for i in perm:
        text_permutated.insert(i, text_ascii[i-1])
    text_permutated = ''.join(text_permutated)
    print('текст после перестановки ', text_permutated)
    l_block = text_ascii[:len(text_ascii)//2]
    print('левая половина ', l_block)
    r_block = text_ascii[len(text_ascii)//2:]
    print('правая половина ', r_block)
    # разбиваем блок R на 4-битовые подблоки
    r_block_4 = list(chunks(r_block, 4))
    # расширяем правый блок
    r_block_6 = []
    for i in range(0, len(r_block_4)):
        first = r_block_4[i-1][3]
        last = r_block_4[(i+1) % len(r_block_4)][0]
        r_block_6.append(first+r_block_4[i]+last)
    # r_block_6 сложение по модулю 2 ключа
    def my_xor(a_list, b_list):
    for a, b in zip(a_list, b_list):
        y = int(a,2) ^ int(b,2)
        yield ('{0:b}'.format(y)).zfill(len(a))
    xored_list = list(my_xor(r_block_6, key))


    # таблица перестановки S-box
    # s_box()

    # соединяем блоки R и L

    # обратная перестановка

print(des_encrypt('АБВГДЕЖЗИ ', 'elelle'))