from Crypto.Cipher import DES, AES
def enclen(p):
   return ((16 - p % 16) & 0xF) + p + 4

def rsb(a, b):
return (0 - a + b) & 0xffffffff

def ands(a, b):
   return (a & b) & 0xffffffff


def _ror(val, bits, bit_size):
    return ((val & (2 ** bit_size - 1)) >> bits % bit_size) |
           (val << (bit_size - (bits % bit_size)) & (2 ** bit_size - 1))


def __ROR4__(a, b):
    return _ror(a, b, 32)


def eor(a, b):
   return (a ^ b) & 0xffffffff


class Crypto(object):
    def __init__(self):
        self.key = b'!*ss!_defaul%t54'
       self.kl = 0x10
        self.sbox0 = bytes.fromhex(
        '637C777BF26B6FC53001672BFED7AB76CA82C97DFA5947F0ADD4A2AF9CA472'
        'C0B7FD9326363FF7CC34A5E5F171D8311504C723C31896059A071280E2EB27'
        'B27509832C1A1B6E5AA0523BD6B329E32F8453D100ED20FCB15B6ACBBE394A'
        '4C58CFD0EFAAFB434D338545F9027F503C9FA851A3408F929D38F5BCB6DA21'
        '10FFF3D2CD0C13EC5F974417C4A77E3D645D197360814FDC222A908846EEB8'
        '14DE5E0BDBE0323A0A4906245CC2D3AC629195E479E7C8376D8DD54EA96C56'
        'F4EA657AAE08BA78252E1CA6B4C6E8DD741F4BBD8B8A703EB5664803F60E61'
        '3557B986C11D9EE1F8981169D98E949B1E87E9CE5528DF8CA1890DBFE64268'
        '41992D0FB054BB16')
    self.plen = 0

def crypt(self, payload):
    if not isinstance(payload, bytes):
        payload = payload.encode('utf8')
    self.plen = len(payload)
    i = 0
    r = [00] * 16
    while i < self.kl:
        a = self.key[i]
        r[i] = self.sbox0[a]
        i += 1

    t = int.from_bytes(r[:4], 'big')
    r[:4] = int.to_bytes(t, 4, 'little')
    t = int.from_bytes(r[4:8], 'big')
    r[4:8] = int.to_bytes(t, 4, 'little')
    t = int.from_bytes(r[8:12], 'big')
    r[8:12] = int.to_bytes(t, 4, 'little')
    t = int.from_bytes(r[12:16], 'big')
    r[12:16] = int.to_bytes(t, 4, 'little')
    b = rsb(self.plen, 0)
    b = ands(b, 0xf)
    c = b + self.plen + 4

    result = [00] * enclen(self.plen)
    result[0] = 0x74
    result[1] = 0x63
    result[2] = 0x02
    result[3] = b
    result[4:len(payload) + 4] = payload

    i = 4
    while i != c:
        a = result[i]
        result[i] = self.sbox0[a]
        i += 1

    a = c - 4
    b = 0
    a = a >> 4
    d = 4
    while b < a:
        c = int.from_bytes(result[d:d + 4], 'big')
        e = int.from_bytes(r[:4], 'little')
        c ^= e
        result[d:d + 4] = int.to_bytes(c, 4, 'big')
        c = int.from_bytes(result[d + 4:d + 8], 'big')
        e = int.from_bytes(r[4:8], 'little')
        c = eor(e, __ROR4__(c, 24))
        result[d + 4:d + 8] = int.to_bytes(c, 4, 'big')
        c = int.from_bytes(result[d + 8:d + 12], 'big')
        e = int.from_bytes(r[8:12], 'little')
        c = eor(e, __ROR4__(c, 16))
        result[d + 8:d + 12] = int.to_bytes(c, 4, 'big')
        c = int.from_bytes(result[d + 12:d + 16], 'big')
        e = int.from_bytes(r[12:16], 'little')
        c = eor(e, __ROR4__(c, 8))
        result[d + 12:d + 16] = int.to_bytes(c, 4, 'big')
        b += 1
        d += 0x10
    return bytes(result)