BaseCTF Week3
杂项
[Week3] 白丝上的 flag
描述：某出题人赠送大家 flag 时遭遇了信号干扰，幸好我们在不知名小网站找到了写入 flag 前的图片，尝试还原信息吧！
提示：flag 是单色
附件：
from PIL import Image
from random import randint
import sys
def ez_add(a,b,c,d):
global iv
h = (a+b+c+d+iv) % 256
e = b
f = c
g = d
iv = (b+c+d+iv) % 256
return e,f,g,h
def confuse(data):
r,g,b,a = data
for _ in range(8):
r,g,b,a = ez_add(r,g,b,a)
return r,g,b,a
def confuse_image(flag):
global iv
iv = flag.getpixel((1,1))[0]
img = Image.new('RGBA', (flag.width, flag.height))
for w in range(img.width):
for h in range(img.height):
img.putpixel((w, h), confuse(flag.getpixel((w,h))))
return img
if __name__ == :
iv =
flag = Image.()
img = confuse_image(flag)
img.save()
