from utils import listener

SBOX = [
    0xf0, 0xf3, 0xf1, 0x69, 0x45, 0xff, 0x2b, 0x4f, 0x63, 0xe1, 0xf3, 0x71, 0x44, 0x1b, 0x35, 0xc8,
    0xbe, 0xc0, 0x1a, 0x89, 0xec, 0x3e, 0x1d, 0x3a, 0xe3, 0xbe, 0xd3, 0xcf, 0x20, 0x4e, 0x56, 0x22,
    0xe4, 0x43, 0x9a, 0x6f, 0x43, 0xa9, 0x87, 0x37, 0xec, 0x2, 0x3b, 0x8a, 0x7a, 0x13, 0x7e, 0x79,
    0xcc, 0x92, 0xd7, 0xd1, 0xff, 0x5e, 0xe2, 0xb1, 0xc9, 0xd3, 0xda, 0x40, 0xfb, 0x80, 0xe6, 0x30,
    0x79, 0x1a, 0x28, 0x13, 0x1f, 0x2c, 0x73, 0xb9, 0x71, 0x9e, 0xa6, 0xd5, 0x30, 0x84, 0x9d, 0xa1,
    0x9b, 0x6d, 0xf9, 0x8a, 0x3d, 0xe9, 0x47, 0x15, 0x50, 0xb, 0xe2, 0x3d, 0x3f, 0x1, 0x59, 0x9b,
    0x85, 0xe4, 0xe5, 0x90, 0xe2, 0x2d, 0x80, 0x5e, 0x6b, 0x77, 0xa1, 0x10, 0x99, 0x72, 0x7f, 0x86,
    0x1f, 0x25, 0xa3, 0xea, 0x57, 0x5f, 0xc4, 0xc6, 0x7d, 0x7, 0x15, 0x90, 0xcb, 0x8c, 0xec, 0x11,
    0x9b, 0x59, 0x1, 0x3f, 0x3d, 0xe2, 0xb, 0x50, 0x15, 0x47, 0xe9, 0x3d, 0x8a, 0xf9, 0x6d, 0x9b,
    0xa1, 0x9d, 0x84, 0x30, 0xd5, 0xa6, 0x9e, 0x71, 0xb9, 0x73, 0x2c, 0x1f, 0x13, 0x28, 0x1a, 0x79,
    0x11, 0xec, 0x8c, 0xcb, 0x90, 0x15, 0x7, 0x7d, 0xc6, 0xc4, 0x5f, 0x57, 0xea, 0xa3, 0x25, 0x1f,
    0x86, 0x7f, 0x72, 0x99, 0x10, 0xa1, 0x77, 0x6b, 0x5e, 0x80, 0x2d, 0xe2, 0x90, 0xe5, 0xe4, 0x85,
    0x22, 0x56, 0x4e, 0x20, 0xcf, 0xd3, 0xbe, 0xe3, 0x3a, 0x1d, 0x3e, 0xec, 0x89, 0x1a, 0xc0, 0xbe,
    0xc8, 0x35, 0x1b, 0x44, 0x71, 0xf3, 0xe1, 0x63, 0x4f, 0x2b, 0xff, 0x45, 0x69, 0xf1, 0xf3, 0xf0,
    0x30, 0xe6, 0x80, 0xfb, 0x40, 0xda, 0xd3, 0xc9, 0xb1, 0xe2, 0x5e, 0xff, 0xd1, 0xd7, 0x92, 0xcc,
    0x79, 0x7e, 0x13, 0x7a, 0x8a, 0x3b, 0x2, 0xec, 0x37, 0x87, 0xa9, 0x43, 0x6f, 0x9a, 0x43, 0xe4,
]
FLAG = "crypto{??????????????????}"


# permute has the following properties:
# permute(permute(x)) = x
# permute(a) ^ permute(b) = permute(a ^ b)
def permute(block):
    result = [0 for _ in range(8)]
    for i in range(8):
        x = block[i]
        for j in range(8):
            result[j] |= (x & 1) << i
            x >>= 1
    return result


def substitute(block):
    return [SBOX[x] for x in block]


def hash(data):
    if len(data) % 4 != 0:
        return None

    state = [16, 32, 48, 80, 80, 96, 112, 128]
    for i in range(0, len(data), 4):
        block = data[i:i+4]
        state[4] ^= block[0]
        state[5] ^= block[1]
        state[6] ^= block[2]
        state[7] ^= block[3]
        state = permute(state)
        state = substitute(state)

    for _ in range(16):
        state = permute(state)
        state = substitute(state)

    output = []
    for _ in range(2):
        output += state[4:]
        state = permute(state)
        state = substitute(state)

    return bytes(output)


class Challenge:
    def __init__(self):
        self.before_input = '"The difference between treason and patriotism is only a matter of dates."\n'

    def challenge(self, msg):
        a = bytes.fromhex(msg['a'])
        b = bytes.fromhex(msg['b'])
        if len(a) % 4 != 0 or len(b) % 4 != 0:
            return {"error": "Inputs must be multiple of the block length!"}
        if a == b:
            return {"error": "Identical inputs are not allowed!"}
        if hash(a) == hash(b):
            return {"flag": f"Well done, here is the flag: {FLAG}"}
        else:
            return {"error": "The hashes don't match!"}


listener.start_server(port=13395)