Crack_Me.py

randomFile = open('randoms.bin', 'r')
randoms = randomFile.readlines()
randoms = [x.strip() for x in randoms]
randomFile.close()

initFile = open('init.bin', 'rb')
base = initFile.read()
base = [ord(x) for x in base]
initFile.close()


def pmulhuw(a, b):
    result = []
    for i in range(len(a)):
        result.append((a[i] * b[i]) >> 16)
    return result

def pmullw(a,b):
    result = []
    for i in range(len(a)):
        result.append((a[i] * b[i]) & 0xffff)
    return result

def punpcklwd(a, b):
    result = []
    for i in range(4):
        result.append(a[i])
        result.append(b[i])
    return result

def punpckhwd(a, b):
    result = []
    for i in range(4, 8):
        result.append(a[i])
        result.append(b[i])
    return result

def itox(x):
    x = hex(x)[2:]
    x = '0' * (len(x) % 2) + x
    return x

def convertToDW(x):
    result = []
    for i in range(0, len(x), 2):
        result.append(int(itox(x[i + 1]) + itox(x[i]), 16))
    return result

def paddd(a, b):
    result = []
    for i in range(len(a)):
        result.append(a[i] + b[i])
    return result

def upgrade(x):
    result = []
    for i in range(0, len(x), 2):
        result.append(int(itox(x[i + 1]) + itox(x[i]), 16))
    return result

def calGuess(lowBase, highBase, b1, b2):
    x1 = pmulhuw(lowBase, b1)
    x2 = pmullw(lowBase, b1)
    xmm4 = punpcklwd(x2, x1)
    xmm0 = punpckhwd(x2, x1)
    x3 = pmulhuw(highBase, b2)
    x4 = pmullw(highBase, b2)
    xmm3 = punpcklwd(x4,x3)
    xmm1 = punpckhwd(x4, x3)
    xmm0 = convertToDW(xmm0)
    xmm1 = convertToDW(xmm1)
    xmm3 = convertToDW(xmm3)
    xmm4 = convertToDW(xmm4)
    xmm0 = paddd(paddd(paddd(xmm0, xmm4), xmm3), xmm1)
    xmm0 = paddd(xmm0, xmm0[2:] + [0]*2)
    xmm0 = paddd(xmm0, xmm0[1:] + [0])
    return xmm0[0]

resultFile = open('results.bin', 'w')

for random in randoms:
    random1 = []
    random2 = []
    count = 0
    for i in random.split():
        n = int(i)
        hexS = hex(n)[2:]
        if len(hexS) < 4:
            hexS = (4 - len(hexS)) * '0' + hexS
        byte1 = hexS[len(hexS) - 2: len(hexS)]
        byte2 = hexS[len(hexS) - 4: len(hexS) - 2]
        if count < 16:
            random1.append(int(byte1, 16))
            random1.append(int(byte2, 16))
        else:
            random2.append(int(byte1, 16))
            random2.append(int(byte2, 16))
        count  += 2
    random1 = upgrade(random1)
    random2 = upgrade(random2)
    result = ''
    for index in range(0, len(base), 16):
        lowBase = base[index:index + 8]
        highBase = base[index + 8 : index + 16]
        result +=  str(calGuess(lowBase, highBase, random1, random2)) + " "
    resultFile.write(result + '\n')

resultFile.close()