cryptography/KeyExpansion.py at main · Lyutoon/cryptography · GitHub

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import binascii
from pwn import *

N_ROUNDS = 10

s_box = (
    0x63, 0x7C, 0x77, 0x7B, 0xF2, 0x6B, 0x6F, 0xC5, 0x30, 0x01, 0x67, 0x2B, 0xFE, 0xD7, 0xAB, 0x76,
    0xCA, 0x82, 0xC9, 0x7D, 0xFA, 0x59, 0x47, 0xF0, 0xAD, 0xD4, 0xA2, 0xAF, 0x9C, 0xA4, 0x72, 0xC0,
    0xB7, 0xFD, 0x93, 0x26, 0x36, 0x3F, 0xF7, 0xCC, 0x34, 0xA5, 0xE5, 0xF1, 0x71, 0xD8, 0x31, 0x15,
    0x04, 0xC7, 0x23, 0xC3, 0x18, 0x96, 0x05, 0x9A, 0x07, 0x12, 0x80, 0xE2, 0xEB, 0x27, 0xB2, 0x75,
    0x09, 0x83, 0x2C, 0x1A, 0x1B, 0x6E, 0x5A, 0xA0, 0x52, 0x3B, 0xD6, 0xB3, 0x29, 0xE3, 0x2F, 0x84,
    0x53, 0xD1, 0x00, 0xED, 0x20, 0xFC, 0xB1, 0x5B, 0x6A, 0xCB, 0xBE, 0x39, 0x4A, 0x4C, 0x58, 0xCF,
    0xD0, 0xEF, 0xAA, 0xFB, 0x43, 0x4D, 0x33, 0x85, 0x45, 0xF9, 0x02, 0x7F, 0x50, 0x3C, 0x9F, 0xA8,
    0x51, 0xA3, 0x40, 0x8F, 0x92, 0x9D, 0x38, 0xF5, 0xBC, 0xB6, 0xDA, 0x21, 0x10, 0xFF, 0xF3, 0xD2,
    0xCD, 0x0C, 0x13, 0xEC, 0x5F, 0x97, 0x44, 0x17, 0xC4, 0xA7, 0x7E, 0x3D, 0x64, 0x5D, 0x19, 0x73,
    0x60, 0x81, 0x4F, 0xDC, 0x22, 0x2A, 0x90, 0x88, 0x46, 0xEE, 0xB8, 0x14, 0xDE, 0x5E, 0x0B, 0xDB,
    0xE0, 0x32, 0x3A, 0x0A, 0x49, 0x06, 0x24, 0x5C, 0xC2, 0xD3, 0xAC, 0x62, 0x91, 0x95, 0xE4, 0x79,
    0xE7, 0xC8, 0x37, 0x6D, 0x8D, 0xD5, 0x4E, 0xA9, 0x6C, 0x56, 0xF4, 0xEA, 0x65, 0x7A, 0xAE, 0x08,
    0xBA, 0x78, 0x25, 0x2E, 0x1C, 0xA6, 0xB4, 0xC6, 0xE8, 0xDD, 0x74, 0x1F, 0x4B, 0xBD, 0x8B, 0x8A,
    0x70, 0x3E, 0xB5, 0x66, 0x48, 0x03, 0xF6, 0x0E, 0x61, 0x35, 0x57, 0xB9, 0x86, 0xC1, 0x1D, 0x9E,
    0xE1, 0xF8, 0x98, 0x11, 0x69, 0xD9, 0x8E, 0x94, 0x9B, 0x1E, 0x87, 0xE9, 0xCE, 0x55, 0x28, 0xDF,
    0x8C, 0xA1, 0x89, 0x0D, 0xBF, 0xE6, 0x42, 0x68, 0x41, 0x99, 0x2D, 0x0F, 0xB0, 0x54, 0xBB, 0x16,
)
xtime = lambda a: (((a << 1) ^ 0x1B) & 0xFF) if (a & 0x80) else (a << 1)

def bytes2matrix(text):
    return [list(text[i:i+4]) for i in range(0, len(text), 4)]

def matrix2hex(matrix):
    res = ''
    for v in matrix:
        for n in v:
            if n < 16:
                res += '0' + hex(n)[2::]
            else:
                res += hex(n)[2::]
    return res

def matrix2bytes(matrix):
    m = ''
    for v in matrix:
        for n in v:
            m += chr(n)
    return str.encode(m)

def key_expansion(master_key):
    master_key = binascii.unhexlify(master_key)
    key_matrix = bytes2matrix(master_key)
    r_con = (
        0x00, 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40,
        0x80, 0x1B, 0x36
    )
    expand_key = key_matrix
    for i in range(4, N_ROUNDS * 4 + 4):
        if i % 4 != 0:
            expand_key.append(xor(bytes(expand_key[i-1]), bytes(expand_key[i-4])))
        else:
            rot = [_ for _ in expand_key[i-1][1::]] + [expand_key[i-1][0]]
            sub = []
            for n in rot:
                x = n & 0b1111
                y = (n >> 4) & 0b1111
                sub.append(s_box[y*16 + x])
            sub[0]  ^= r_con[i // 4]
            w_i = xor(sub, expand_key[i-4])
            expand_key.append(w_i)
    return [list(expand_key[i:i+4]) for i in range(0, len(expand_key), 4)]

def add_round_key(s, k):
    return [[s[i][j] ^ k[i][j] for j in range(len(s[0]))] for i in range(len(s))]

def sub_bytes(s, sbox):
    return [[sbox[s[i][j]] for j in range(len(s))] for i in range(len(s))]

def shift_rows(s):
    s[0][1], s[1][1], s[2][1], s[3][1] = s[1][1], s[2][1], s[3][1], s[0][1]
    s[0][2], s[1][2], s[2][2], s[3][2] = s[2][2], s[3][2], s[0][2], s[1][2]
    s[0][3], s[1][3], s[2][3], s[3][3] = s[3][3], s[0][3], s[1][3], s[2][3]

def mix_single_column(a):
    t = a[0] ^ a[1] ^ a[2] ^ a[3]
    u = a[0]
    a[0] ^= t ^ xtime(a[0] ^ a[1])
    a[1] ^= t ^ xtime(a[1] ^ a[2])
    a[2] ^= t ^ xtime(a[2] ^ a[3])
    a[3] ^= t ^ xtime(a[3] ^ u)

def mix_columns(s):
    for i in range(4):
        mix_single_column(s[i])

def encrypt(m, k):
    m_matrix = bytes2matrix(binascii.unhexlify(m))
    round_keys = key_expansion(k)
    m_matrix = add_round_key(m_matrix, round_keys[0])
    for i in range(1, N_ROUNDS):
        m_matrix = sub_bytes(m_matrix, s_box)
        shift_rows(m_matrix)
        mix_columns(m_matrix)
        m_matrix = add_round_key(m_matrix, round_keys[i])
    m_matrix = sub_bytes(m_matrix, s_box)
    shift_rows(m_matrix)
    ciphertext = add_round_key(m_matrix, round_keys[-1])
    print(ciphertext)
    ciphertext = matrix2hex(ciphertext)
    return ciphertext

master_key = '2B7E151628AED2A6ABF7158809CF4F3C'
m = '3243F6A8885A308D313198A2E0370734'
e = encrypt(m, master_key)
print(e)