def q_key(k: bytes):
#part 1
left_part = ByteUtils.getLeftPart(k)
sqr_1 = FFunc.f_func(left_part, Key.S_1)
right_part = ByteUtils.xor(sqr_1, ByteUtils.getRightPart(k))
#part 2
left_part, right_part = right_part, left_part
sqr_2 = FFunc.f_func(left_part, Key.S_2)
right_part = ByteUtils.xor(sqr_2, right_part)
#part 3
left_part, right_part = right_part, left_part
part_3_res = ByteUtils.xor(left_part + right_part, k)
#part 4
left_part = ByteUtils.getLeftPart(part_3_res)
right_part = ByteUtils.getRightPart(part_3_res)
sqr_3 = FFunc.f_func(left_part, Key.S_3)
right_part = ByteUtils.xor(sqr_3, right_part)
#part 5
left_part, right_part = right_part, left_part
sqr_4 = FFunc.f_func(left_part, Key.S_4)
right_part = ByteUtils.xor(sqr_4, right_part)
return right_part + left_part
def fl_inv(y: bytes, kl: bytes):
y_l = ByteUtils.getLeftPart(y)
y_r = ByteUtils.getRightPart(y)
kl_l = ByteUtils.getLeftPart(kl)
kl_R = ByteUtils.getRightPart(kl)
sqr_1 = (int.from_bytes(y_r, "little")
| int.from_bytes(kl_R, "little")).to_bytes(4, "little")
sqr_2 = ByteUtils.xor(sqr_1, y_l)
sqr_3 = (int.from_bytes(sqr_2, "little")
& int.from_bytes(kl_l, "little")).to_bytes(4, "little")
sqr_4 = ByteUtils.rol(sqr_3, 1)
sqr_5 = ByteUtils.xor(sqr_4, y_r)
return sqr_2 + sqr_5
def decrypt(x: bytes, key: bytes):
if (len(x) < 16):
raise Exception("text should contain more or equal than 16 bytes")
elif (len(key) != 16):
raise Exception("text should have 16 bytes")
elif (len(x) % 16 != 0):
raise Exception("text should have total each block")
count = len(x) // 16
blocks = []
for i in range(1, count + 1):
blocks.append(x[16 * (i - 1): 16 * i])
cipher_blocks = []
init_block = key
for i in range(len(blocks)):
cipher_block = ByteUtils.xor(blocks[i], init_block)
cipher_blocks.append(cipher_block)
init_block = blocks[i]
result = bytes()
for block in cipher_blocks:
result += block
if (CBC.is_block_empty(CBC.get_16_bytes_block(result, 1))):
return CBC.handle_decrypt_if_last_block_empty(result)
else:
return result
def encrypt_if_block_not_total(x: bytes, key: bytes):
count = len(x) // 16
blocks = []
for i in range(1, count + 1):
blocks.append(x[16 * (i - 1): 16 * i])
last_bloc = x[16 * count: len(x)]
if(len(last_bloc) == 16):
blocks.append(last_bloc)
else:
empty_bytes = 0
while(len(last_bloc) < 15):
empty_bytes += 1
last_bloc += int(0).to_bytes(1, "little")
last_bloc += int(empty_bytes).to_bytes(1, "little")
blocks.append(last_bloc)
blocks.append(int(0).to_bytes(16, "little"))
cipher_blocks = []
init_block = key
for i in range(len(blocks)):
cipher_block = ByteUtils.xor(blocks[i], init_block)
cipher_blocks.append(cipher_block)
init_block = cipher_block
result = bytes()
for block in cipher_blocks:
result += block
return result
def fl_func(x: bytes, kl: bytes):
x_l = ByteUtils.getLeftPart(x)
x_r = ByteUtils.getRightPart(x)
kl_l = ByteUtils.getLeftPart(kl)
kl_r = ByteUtils.getRightPart(kl)
sqr_1 = int(
int.from_bytes(kl_l, "little")
& int.from_bytes(x_l, "little")).to_bytes(4, "little")
sqr_2 = ByteUtils.rol(sqr_1, 1)
sqr_3 = ByteUtils.xor(sqr_2, x_r)
sqr_4 = (int.from_bytes(sqr_3, "little")
| int.from_bytes(kl_r, "little")).to_bytes(4, "little")
sqr_5 = ByteUtils.xor(sqr_4, x_l)
return sqr_5 + sqr_3
def encrypt_if_block_total(x: bytes, key: bytes):
count = len(x) // 16
blocks = []
for i in range(1, count + 1):
blocks.append(x[16 * (i - 1): 16 * i])
cipher_blocks = []
init_block = key
for i in range(len(blocks)):
cipher_block = ByteUtils.xor(blocks[i], init_block)
cipher_blocks.append(cipher_block)
init_block = cipher_block
result = bytes()
for block in cipher_blocks:
result += block
return result
def encrypt(x: bytes, key: bytes):
if (len(x) != 16):
raise Exception("entry value should be 16 bytes")
elif (len(key) != 16):
raise Exception("key should be 16 bytes")
Camelia.init_key_k(key)
left = ByteUtils.xor(ByteUtils.getLeftPart(x), Camelia.kw_i[0])
right = ByteUtils.xor(ByteUtils.getRightPart(x), Camelia.kw_i[1])
for i in range(6):
sqr = FFunc.f_func(left, Camelia.k_i[i])
right = ByteUtils.xor(right, sqr)
right, left = left, right
left = FLFunction.fl_func(left, Camelia.kl_i[0])
right = FLFunction.fl_inv(right, Camelia.kl_i[1])
for i in range(6, 12):
sqr = FFunc.f_func(left, Camelia.k_i[i])
right = ByteUtils.xor(right, sqr)
right, left = left, right
left = FLFunction.fl_func(left, Camelia.kl_i[2])
right = FLFunction.fl_inv(right, Camelia.kl_i[3])
for i in range(12, 18):
sqr = FFunc.f_func(left, Camelia.k_i[i])
right = ByteUtils.xor(right, sqr)
right, left = left, right
left, right = ByteUtils.xor(right, Camelia.kw_i[2]), ByteUtils.xor(
left, Camelia.kw_i[3])
return left + right
def test_xor(self):
self.assertEqual(self.res_xor.hex(),
ByteUtils.xor(self.bytes_, self.other_xor).hex())