Olá boa tarde possuo um código de implementação de cifra de AES mas não estou conseguindo chegar no resultado correto abaixo está o código mencionado:
S-Box do AES
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
]
RCON
R_CON = [
0x01, 0x02, 0x04, 0x08, 0x10,
0x20, 0x40, 0x80, 0x1B, 0x36
]
Função de multiplicação em GF(2^8)
def gf_mult(x, y):
result = 0
while y > 0:
if y & 1:
result ^= x
x <<= 1
if x & 0x100:
x ^= 0x11B
y >>= 1
return result
Função para substituir bytes usando a S-Box
def substitute_bytes(state):
for i in range(4):
for j in range(4):
state[j][i] = S_BOX[state[j][i]]
return state
Função ShiftRows
def shift_rows(state):
state[1] = state[1][1:] + state[1][:1]
state[2] = state[2][2:] + state[2][:2]
state[3] = state[3][3:] + state[3][:3]
return state
Função MixColumns
def mix_columns(state):
for i in range(4):
a = state[i]
state[i] = [
gf_mult(a[0], 2) ^ gf_mult(a[1], 3) ^ a[2] ^ a[3],
a[0] ^ gf_mult(a[1], 2) ^ gf_mult(a[2], 3) ^ a[3],
a[0] ^ a[1] ^ gf_mult(a[2], 2) ^ gf_mult(a[3], 3),
gf_mult(a[0], 3) ^ a[1] ^ a[2] ^ gf_mult(a[3], 2),
]
return state
Função AddRoundKey
def add_round_key(state, key):
for i in range(4):
for j in range(4):
state[j][i] ^= key[j][i]
return state
Função de expansão de chave
def key_expansion(key):
key_schedule = []
for i in range(4):
key_schedule.append([key[j + i * 4] for j in range(4)])
for i in range(4, 44): # Para AES-128, temos 11 chaves
temp = key_schedule[i - 1][:]
if i % 4 == 0:
# Rotação e substituição
temp = [
S_BOX[temp[1]],
S_BOX[temp[2]],
S_BOX[temp[3]],
S_BOX[temp[0]]
]
temp[0] ^= R_CON[i // 4 - 1]
key_schedule.append([key_schedule[i - 4][j] ^ temp[j] for j in range(4)])
return key_schedule
Função principal de encriptação AES
def aes_encrypt(plaintext, key):
# Inicializa o estado
state = [list(plaintext[i:i + 4]) for i in range(0, 16, 4)]
key_schedule = key_expansion(key)
print("Texto plano inicial:")
for row in state:
print([f'{byte:02x}' for byte in row])
# Primeira rodada: AddRoundKey
state = add_round_key(state, key_schedule[0:4])
print("\nApós AddRoundKey inicial:")
for row in state:
print([f'{byte:02x}' for byte in row])
# Rodadas de encriptação
for round in range(1, 10):
print(f"\nRodada {round}:")
state = substitute_bytes(state)
print("Após SubstituteBytes:")
for row in state:
print([f'{byte:02x}' for byte in row])
state = shift_rows(state)
print("Após ShiftRows:")
for row in state:
print([f'{byte:02x}' for byte in row])
state = mix_columns(state)
print("Após MixColumns:")
for row in state:
print([f'{byte:02x}' for byte in row])
state = add_round_key(state, key_schedule[round * 4:(round + 1) * 4])
print("Após AddRoundKey:")
for row in state:
print([f'{byte:02x}' for byte in row])
# Última rodada (sem MixColumns)
print("\nÚltima Rodada:")
state = substitute_bytes(state)
state = shift_rows(state)
state = add_round_key(state, key_schedule[40:44])
print("Após AddRoundKey final:")
for row in state:
print([f'{byte:02x}' for byte in row])
return state
Exemplo de uso
if name == “main”:
# Chave e texto plano fornecidos
key = bytes.fromhex(“0123456789abcdeffedcba9876543210”)
plaintext = bytes.fromhex(“0f1571c947d9e8590cb7add6af7f6798”)
# Encriptação
ciphertext = aes_encrypt(plaintext, key)
ciphertext_hex = ''.join(f'{byte:02x}' for row in ciphertext for byte in row)
print("\nTexto cifrado:", ciphertext_hex)
esse e o código da cifra estou fazendo ele a mão sem o uso de bibliotecas prontas o resultado que eu espero e esse aqui :ff0b844a0853bf7c6934ab4364148fb9 esse e o texto cifrado que deveria sair e esse e o que esta saindo : fdfa158e12d390937c743d7311551f37.
Não sei aonde estou errando, as rodadas pelo menos as primeiras estão batendo com o material mas ela esta trocando as linhas pelas colunas e as colunas pelas linhas do resultado esperado, se alguem puder me ajudar ficaria muito grato