2023第三届“香山杯”网络安全大赛｜pintu Writeup

起初以为是北京办的比赛，结果是广东省中山市的，此香山非彼香山🍁

pintu

被这道题目名误导了，导致卡了很久😭
题目一共有4703张图片，其中白色2304张图片，黑色2363张图片，图片的宽度都是65，只有高度不一样。
黑色图片的高度去重之后如下：
heights: [64, 65, 66, 67, 70, 71, 40, 60, 61, 62, 63]
白色图片的高度去重之后如下：
heights: [64, 65, 66, 67, 70, 71, 40, 60, 61, 62, 63]
刚开始觉得是一张二维码，拆分组合宽高，发现都不对，最后觉得可能是一张矩形flag的图片被切割了。
那么最有可能的就是在高度这做文章了，按图片名的顺序提取所有高度：

# -*- coding: utf-8 -*-
# @Author  : 1cePeak

from PIL import Image

# 指定目录路径
directory = 'pintu'  # 修改为你的目录路径

height_string = ''

# 循环遍历文件名中的数字范围
for i in range(1, 4704):  # 包括1和4703
    img_file = f'{i}.png'  # 生成文件名
    img_path = f'{directory}/{img_file}'  # 生成完整文件路径

    # 打开图片
    image = Image.open(img_path)

    # 获取图片的宽度和高度
    width, height = image.size
    height_string += str(height) + ' '

    # 关闭图片
    image.close()

print(height_string)

读出来的数据如下：

67 64 40 70 62 40 67 60 40 70 64 40 66 67 40 65 63 40 70 63 40 67 60 40 67 61 40 65 63 40 70 63 40 70 65 40 65 62 40 70 63 40 70 64 40 70 66 40 67 62 40 66 66 40 70 64 40 70 64 40 66 67 40 70 62 40 65 60 40 70 63 40 67 65 40 70 66 40 70 63 40 66 71 40 65 60 40 67 70 40 67 65 40 70 66 40 67 63 40 70 65 40 70 71 40 67 60 40 66 67 40 70 63 40 65 60 40 67 67 40 67 71 40 70 66 40 67 60 40 70 65 40 70 67 40 67 67 40 67 66 40 67 66 40 67 61 40 70 66 40 67 65 40 70 67 40 67 63 40 70 64 40 67 65 40 67 66 40 67 64 40 71 60 40 70 63 40 66 71 40 65 60 40 67 70 40 67 65 40 70 66 40 67 67 40 70 62 40 67 60 40 70 65 40 70 67 40 70 71 40 65 61 40 66 71 40 67 64 40 70 65 40 65 61 40 70 66 40 67 65 40 71 60 40 66 67 40 67 70 40 67 61 40 70 66 40 67 65 40 70 65 40 65 60 40 70 63 40 67 65 40 70 61 40 67 67 40 67 70 40 70 70 40 66 71 40 65 60 40 70 67 40 66 67 40 70 66 40 67 67 40 70 62 40 67 61 40 70 64 40 67 65 40 70 66 40 67 65 40 67 70 40 67 67 40 67 67 40 65 60 40 70 70 40 67 67 40 70 62 40 67 65 40 67 66 40 67 61 40 66 71 40 65 60 40 70 65 40 70 63 40 65 63 40 70 63 40 66 71 40 67 71 40 67 60 40 70 67 40 70 64 40 67 67 40 70 62 40 66 70 40 70 62 40 67 70 40 71 60 40 70 66 40 70 64 40 67 71 40 65 63 40 67 66 40 67 70 40 67 61 40 71 60 40 66 67 40 67 61 40 70 71 40 70 67 40 66 70 40 70 66 40 67 71 40 70 66 40 70 71 40 70 65 40 67 61 40 65 63 40 67 65 40 70 71 40 67 65 40 70 66 40 70 67 40 70 64 40 67 67 40 70 62 40 66 70 40 70 62 40 67 67 40 70 62 40 66 66 40 67 61 40 65 62 40 71 60 40 66 70 40 67 70 40 67 61 40 71 60 40 67 64 40 66 71 40 65 62 40 70 64 40 67 66 40 70 67 40 67 63 40 70 62 40 70 71 40 70 67 40 67 63 40 70 64 40 67 64 40 70 66 40 67 71 40 70 66 40 70 67 40 70 64 40 67 67 40 70 65 40 70 63 40 67 71 40 67 67 40 70 62 40 67 61 40 70 70 40 67 65 40 65 62 40 67 66 40 67 71 40 67 70 40 67 67 40 65 60 40 70 66 40 67 65 40 65 61 40 67 64 40 70 67 40 67 63 40 70 62 40 70 67 40 67 61 40 67 63 40 70 64 40 67 64 40 70 66 40 67 67 40 70 62 40 70 67 40 70 64 40 67 67 40 70 65 40 70 63 40 70 66 40 67 64 40 70 66 40 65 61 40 67 60 40 66 71 40 70 66 40 67 66 40 66 71 40 67 64 40 70 65 40 65 60 40 70 70 40 67 65 40 71 60 40 66 67 40 66 67 40 67 70 40 71 60 40 67 65 40 70 67 40 67 63 40 70 64 40 67 64 40 70 66 40 67 64 40 71 60 40 70 63 40 66 71 40 65 60 40 67 70 40 67 65 40 70 66 40 67 70 40 71 60 40 70 66 40 70 64 40 67 71 40 70 66 40 67 66 40 66 71 40 67 64 40 70 65 40 65 60 40 70 66 40 66 67 40 70 67 40 66 70 40 70 66 40 67 61 40 70 66 40 67 65 40 70 65 40 67 65 40 70 64 40 67 66 40 66 71 40 67 71 40 67 60 40 70 67 40 70 64 40 67 67 40 70 62 40 66 70 40 67 67 40 67 67 40 70 62 40 67 61 40 70 64 40 67 65 40 70 66 40 67 65 40 70 71 40 67 71 40 70 65 40 65 61 40 70 70 40 67 63 40 70 62 40 67 64 40 70 67 40 67 65 40 67 64 40 67 65 40 67 61 40 67 63 40 70 64 40 67 64 40 70 66 40 67 65 40 70 66 40 70 63 40 67 61 40 66 71 40 67 71 40 66 70 40 70 61 40 67 70 40 67 64 40 65 60 40 70 65 40 70 67 40 70 67 40 66 67 40 67 66 40 67 61 40 66 66 40 65 60 40 70 67 40 70 67 40 70 64 40 66 70 40 66 67 40 67 71 40 70 65 40 65 61 40 66 71 40 70 67 40 70 61 40 70 62 40 70 61 40 67 64 40 70 62 40 66 67 40 70 70 40 67 65 40 70 67 40 66 70 40 67 60 40 67 67 40 70 62 40 66 66 40 66 70 40 67 63 40 67 70 40 67 66 40 67 64 40 67 61 40 70 66 40 70 70 40 66 71 40 70 65 40 70 63 40 70 62 40 70 60 40 67 67 40 67 60 40 66 71 40 70 65 40 70 67 40 65 63 40 70 64 40 70 71 40 67 71 40 67 60 40 67 60 40 66 71 40 66 71 40 70 67 40 66 67 40 70 64 40 67 71 40 70 62 40 67 61 40 70 66 40 70 61 40 70 63 40 66 66 40 70 62 40 67 70 40 67 70 40 67 64 40 67 62 40 67 65 40 70 63 40 65 60 40 67 62 40 67 65 40 70 62 40 66 70 40 70 70 40 67 63 40 70 66 40 70 63 40 70 63 40 67 71 40 70 66 40 66 71 40 70 70 40 66 71 40 65 63 40 67 64 40 70 67 40 67 70 40 67 64 40 67 61 40 70 67 40 66 67 40 70 67 40 66 67 40 67 66 40 67 63 40 67 64 40 67 63 40 70 70 40 66 65 40 70 64 40 66 66 40 70 70 40 67 70 40 71 60 40 70 66 40 70 65 40 70 71 40 70 61 40 70 62 40 70 62 40 67 71 40 70 66 40 67 63 40 70 66 40 67 67 40 67 67 40 66 70 40 67 70 40 67 71 40 70 62 40 67 60 40 70 67 40 67 65 40 70 62 40 65 60 40 67 64 40 67 71 40 67 64 40 67 60 40 70 65 40 65 60 40 70 63 40 65 60 40 67 64 40 67 61 40 66 66 40 67 66 40 66 71 40 67 65 40 70 64 40 67 65 40 70 61 40 67 71 40 67 60 40 67 61 40 70 65 40 65 62 40 70 65 40 67 65 40 67 61 40 67 64 40 67 70 40 65 60 40 67 60 40 66 71 40 70 65 40 66 67 40 67 70 40 67 65 40 70 71 40 65 60 40 66 71 40 70 61 40 70 61 40 67 65 40 67 71 40 67 65 40 70 66 40 67 60 40 70 65 40 65 60 40 70 64 40 67 64 40 70 66 40 67 66 40 66 66 40 70 70 40 66 71 40 70 63 40 70 63 40 65 61 40 67 70 40 67 67 40 70 61 40 70 70 40 70 66 40 67 67 40 67 70 40 71 60 40 71 60 40 67 65 40 70 71 40 65 60 40 70 65 40 70 61 40 70 64 40 67 64 40 70 60 40 67 67 40 70 66 40 70 63 40 70 65 40 65 60 40 70 63 40 65 60 40 70 62 40 67 63 40 67 70 40 70 65 40 70 70 40 67 65 40 67 67 40 67 66 40 70 66 40 67 65 40 67 60 40 66 67 40 70 67 40 65 64 40 65 62 40 67 65 40 67 66 40 67 64 40 67 67 40 71 60 40 70 70 40 67 71 40 65 60 40 67 64 40 70 66 40 67 64 40 67 70 40 66 71 40 67 61 40 67 63 40 65 64 40 67 64 40 70 61 40 67 71 40 65 63 40 67 61 40 66 70 40 67 65 40 70 66 40 67 64 40 70 67 40 67 71 40 70 61 40 65 61 40 70 64 40 66 65 40 67 67 40 70 63 40 67 66 40 67 64 40 70 66 40 67 60 40 67 60 40 70 65 40 65 60 40 70 63 40 67 70 40 67 61 40 66 65 40 70 71 40 70 67 40 65 62 40 70 71 40 65 60 40 70 71 40 67 67 40 67 60 40 67 61 40 70 67 40 70 67 40 70 65 40 70 63 40 67 63 40 67 70 40 67 64 40 65 60 40 70 67 40 70 71 40 65 63 40 65 61 40 66 71 40 67 61 40 66 65 40 65 62 40 70 67 40 70 71 40 70 64 40 67 64 40 70 67 40 67 62 40 66 66 40 65 62 40 67 61 40 70 63 40 71 60 40 65 60 40 67 66 40 67 64 40 67 63 40 65 62 40 70 67 40 66 71 40 67 70 40 66 70 40 70 67 40 67 64 40 70 61 40 65 61 40 70 64 40 67 65 40 70 64 40 66 66 40 70 64 40 67 61 40 65 63 40 67 66 40 66 71 40 65 62 40 65 63 40 66 70 40 67 62 40 67 64 40 67 70 40 70 63 40 70 65 40 70 65 40 67 66 40 71 60 40 70 66 40 67 71 40 66 66 40 67 60 40 67 60 40 67 67 40 67 67 40 67 64 40 70 63 40 67 64 40 67 70 40 65 60 40 70 65 40 65 60 40 67 70 40 70 63 40 70 62 40 67 67 40 65 62 40 70 71 40 70 64 40 70 63 40 67 71 40 67 65 40 70 67 40 67 67 40 66 71 40 71 60 40 66 71 40 70 71 40 67 70 40 65 61 40 66 66 40 67 71 40 70 61 40 65 62 40 70 65 40 67 65 40 71 60 40 67 66 40 66 70 40 67 70 40 67 60 40 67 61 40 70 66 40 70 61 40 65 62 40 70 63 40 67 70 40 67 64 40 67 70 40 67 63 40 70 65 40 70 65 40 67 71 40 67 64 40 70 70 40 67 70 40 71 60 40 65 61 40 67 60 40 66 67 40 65 60 40 65 61 40 67 71 40 67 71 40 67 64 40 67 60 40 70 70 40 67 71 40 67 70 40 67 66 40 71 60 40 67 65 40 67 60 40 66 71 40 70 64 40 70 61 40 67 67 40 70 64 40 67 71 40 67 63 40 65 62 40 65 61 40 70 66 40 67 61 40 70 63 40 67 65 40 67 70 40 67 65 40 66 66 40 67 65 40 70 64 40 66 67 40 70 66 40 70 63 40 70 61 40 67 63 40 67 70 40 70 65 40 70 67 40 66 71 40 67 70 40 66 67 40 67 66 40 67 61 40 67 60 40 66 70 40 70 67 40 66 67 40 70 71 40 70 64 40 67 64 40 67 64 40 70 65 40 65 60 40 67 61 40 67 63 40 70 63 40 67 66 40 67 62 40 67 61 40 70 62 40 65 61 40 70 64 40 67 61 40 65 62 40 70 63 40 70 62 40 67 63 40 67 67 40 71 60 40 70 65 40 66 71 40 70 63 40 65 60 40 70 71 40 67 70 40 71 60 40 66 70 40 70 64 40 66 65 40 67 67 40 66 70 40 70 65 40 67 64 40 70 65 40 70 71 40 66 71 40 67 65 40 70 64 40 67 64 40 70 61 40 67 61 40 70 66 40 65 62 40 66 71 40 70 63 40 65 64 40 67 64 40 70 62 40 67 70 40 70 66 40 67 60 40 70 67 40 67 61 40 67 67 40 66 67 40 70 65 40 67 64 40 67 63 40 65 61 40 70 70 40 67 65 40 67 70 40 65 60 40 67 70 40 67 65 40 71 60 40 65 62 40 66 71 40 65 62 40 65 63 40 66 67 40 67 62 40 67 61 40 66 66 40 65 60 40 66 70 40 67 61 40 70 71 40 70 64 40 66 66 40 67 65 40 67 60 40 67 67 40 67 62 40 70 63 40 65 61 40 65 61 40 70 70 40 67 63 40 70 66 40 67 62 40 67 61 40 67 65 40 65 64 40 67 65 40 67 60 40 67 71 40 65 62 40 70 71 40 70 64 40 66 67 40 70 61 40 65 60 40 66 67 40 67 61 40 70 62 40 71 60 40 67 61 40 65 62 40 70 66 40 70 63 40 70 71 40 67 63 40 67 60 40 67 63 40 70 67 40 66 71 40 65 64 40 66 70 40 70 70 40 67 63 40 67 70 40 71 60 40 66 71 40 70 67 40 65 62 40 66 66 40 70 64 40 67 63 40 65 63 40 70 61 40 70 65 40 66 67 40 65 60 40 67 66 40 70 63 40 67 61 40 65 63 40 67 66 40 66 71 40 70 63 40 70 66 40 70 64 40 67 71 40 67 63 40 67 60 40 65 60 40 66 71 40 65 62 40 70 71 40 67 65 40 70 64 40 67 61 40 67 67 40 65 61 40 70 64 40 67 63 40 70 66 40 66 67 40 67 65 40 67 67 40 67 63 40 70 71 40 70 64 40 66 71 40 65 61 40 67 65 40 67 62 40 67 64 40 67 67 40 70 70 40 70 70 40 67 63 40 70 71 40 65 61 40 70 60 40 67 63 40 65 63 40 65 60 40 66 71 40 67 65 40 65 61 40 70 64 40 70 66 40 67 70 40 67 60 40 71 60 40 66 71 40 70 67 40 70 71 40 67 65 40 67 70 40 67 71 40 65 63 40 67 66 40 67 61 40 70 67 40 65 60 40 70 63 40 66 67 40 67 65 40 71 60 40 70 71 40 66 71 40 67 65 40 65 63 40 71 60 40 70 65 40 67 70 40 70 61 40 71 60 40 70 70 40 67 65 40 67 71 40 66 70 40 70 70 40 67 66 40 66 66 40 66 67 40 70 67 40 65 62 40 67 67 40 67 64 40 70 62 40 67 65 40 71 60 40 67 60 40 70 66 40 66 65 40 71 60 40 66 67 40 67 66 40 67 65 40 67 67 40 65 61 40 66 70 40 70 63 40 70 71 40 70 62 40 70 71 40 67 65 40 66 66 40 70 70 40 66 71 40 65 62 40 67 70 40 66 67 40 67 63 40 67 64 40 67 64 40 70 66 40 70 64 40 66 71 40 65 62 40 67 65 40 67 60 40 67 65 40 71 60 40 67 63 40 70 64 40 66 65 40 65 60 40 67 65 40 67 64 40 67 67 40 70 62 40 65 61 40 70 65 40 70 67 40 70 61 40 70 62 40 70 65 40 67 67 40 67 60 40 70 65 40 70 67 40 66 71 40 67 70 40 66 70 40 70 67 40 67 64 40 67 64 40 67 62 40 67 60 40 66 67 40 67 70 40 66 70 40 67 70 40 67 70 40 67 70 40 67 64 40 67 60 40 67 61 40 67 67 40 71 60 40 70 70 40 67 67 40 66 71 40 70 70 40 70 70 40 67 63 40 70 71 40 70 64 40 66 66 40 67 65 40 66 66 40 67 63 40 70 65 40 65 60 40 71 60 40 67 64 40 70 60 40 67 64 40 67 63 40 70 70 40 70 66 40 66 67 40 70 63 40 67 65 40 70 71 40 67 71 40 67 63 40 65 60 40 67 62 40 70 65 40 65 63 40 66 70 40 67 62 40 67 65 40 67 67 40 65 61 40 70 65 40 70 63 40 70 62 40 67 64 40 71 60 40 67 71 40 67 60 40 67 61 40 70 63 40 65 64 40 65 62 40 65 60 40 67 71 40 67 61 40 67 60 40 66 70 40 70 66 40 70 61 40 70 65 40 65 61 40 67 64 40 67 61 40 66 65 40 70 71 40 70 65 40 70 67 40 65 60 40 70 64 40 70 70 40 67 61 40 70 62 40 66 65 40 70 65 40 70 63 40 65 63 40 67 65 40 66 71 40 67 65 40 66 66 40 70 70 40 66 71 40 65 60 40 65 60 40 65 60 40 65 60 40 67 64 40 70 62 40 70 64 40 70 64 40 67 61 40 65 62 40 66 66 40 70 62 40 67 63 40 70 65 40 65 60 40 70 64 40 67 67 40 67 71 40 67 65 40 67 70 40 67 61 40 67 64 40 65 61 40 70 65 40 66 67 40 70 64 40 70 62 40 70 66 40 67 63 40 71 60 40 70 66 40 66 71 40 70 63 40 70 67 40 66 67 40 67 70 40 67 70 40 71 60 40 70 62 40 70 65 40 70 67 40 70 66 40 70 63 40 67 66 40 67 64 40 70 65 40 65 60 40 66 71 40 67 67 40 65 63 40 66 67 40 67 71 40 67 64 40 67 67 40 65 61 40 70 66 40 66 67 40 65 63 40 71 60 40 70 62 40 67 67 40 70 62 40 70 70 40 66 70 40 66 65 40 65 61 40 71 60 40 70 70 40 67 70 40 67 60 40 66 67 40 70 64 40 67 65 40 70 67 40 66 67 40 67 65 40 67 64 40 71 60 40 67 63 40 70 67 40 67 67 40 67 67 40 67 66 40 66 70 40 67 61 40 70 62 40 66 71 40 70 67 40 70 65 40 70 61 40 70 64 40 70 60 40 67 64 40 71 60 40 70 65 40 70 70 40 70 63 40 67 67 40 66 66 40 70 70 40 67 70 40 67 60 40 70 64 40 70 66 40 70 61 40 70 63 40 66 67 40 67 66 40 67 63 40 67 63 40 71 60 40 70 66 40 67 63 40 65 60 40 70 64 40 66 67 40 67 70 40 70 62 40 67 63 40 66 71 40 67 65 40 65 60 40 65 60 40 67 66 40 67 61 40 71 60 40 66 71 40 70 67 40 66 71 40 70 65 40 70 64 40 67 67 40 67 64 40 70 65 40 65 60 40 70 67 40 66 67 40 71 60 40 67 64 40 71 60 40 67 64 40 70 66 40 65 62 40 67 60 40 70 65 40 65 60 40 70 63 40 67 64 40 67 67 40 70 66 40 66 70 40 67 60 40 70 61 40 70 66 40 70 62 40 70 70 40 67 61 40 67 60 40 67 60 40 67 61 40 70 67 40 70 65 40 66 66 40 70 71 40 67 64 40 67 64 40 71 60 40 67 61 40 65 62 40 65 64 40 66 67 40 70 71 40 67 61 40 70 65 40 70 71 40 67 62 40 70 63 40 70 67 40 66 66 40 70 60 40 67 61 40 70 65 40 65 62 40 66 71 40 70 67 40 70 71 40 70 62 40 70 61 40 67 64 40 67 60 40 70 66 40 67 61 40 66 71 40 67 67 40 67 66 40 67 66 40 67 70 40 70 66 40 70 66 40 70 64 40 70 63 40 65 62 40 67 65 40 67 70 40 67 71 40 70 61 40 65 62 40 66 70 40 67 65 40 70 63 40 70 63 40 67 62 40 67 66 40 66 65 40 70 71 40 66 70 40 67 61 40 70 62 40 67 64 40 70 66 40 67 70 40 66 66 40 67 60 40 70 65 40 70 63 40 67 70 40 67 65 40 67 60 40 67 70 40 71 60 40 67 62 40 66 70 40 67 63 40 65 60 40 66 67 40 67 60 40 67 71 40 70 65 40 65 61 40 70 65 40 65 60 40 67 67 40 65 60 40 67 70 40 67 67 40 67 60 40 70 67 40 70 65 40 67 61 40 70 63 40 67 65 40 70 63 40 67 67 40 67 60 40 67 67 40 67 61 40 70 67 40 67 70 40 65 60 40 70 67 40 67 61 40 67 67 40 65 61 40 70 64 40 66 65 40 67 71 40 66 66 40 70 64 40 67 60 40 65 62 40 65 60 40 66 71 40 66 71 40 71 60 40 66 70 40 66 67 40 67 62 40 67 60 40 70 67 40 67 60 40 70 61 40 70 64 40 67 66 40 67 67 40 67 71 40 66 65 40 71 60 40 70 65 40 70 67 40 70 66 40 67 64 40 70 65 40 67 70 40 67 60 40 66 66 40 66 70 40 70 63 40 70 64 40 70 63 40 67 66 40 67 67 40 67 70 40 67 64 40 70 70 40 66 65 40 70 64 40 66 66 40 70 67 40 67 65 40 67 63 40 65 61 40 67 60 40 70 61 40 70 71 40 71 60 40 70 62 40 67 61 40 71 60 40 70 70 40 67 61 40 70 67 40 67 71 40 66 70 40 66 67 40 67 61 40 67 70 40 66 70 40 70 64 40 70 63 40 67 70 40 71 60 40 70 62 40 67 65 40 71 60 40 67 64 40 66 70 40 70 61 40 71 60 40 66 67 40 67 70 40 67 61 40 70 66 40 67 65 40 70 67 40 67 63 40 70 64 40 67 64 40 70 66 40 67 61 40 70 66 40 70 66 40 67 62 40 67 65 40 67 67 40 67 65 40 67 70 40 67 64 40 70 61 40 65 61 40 70 66 40 66 67 40 67 70 40 65 60 40 67 70 40 67 64 40 66 71 40 65 61 40 70 67 40 67 61 40 71 60 40 66 66 40 70 67 40 67 71 40 67 70 40 70 70 40 70 64 40 66 67 40 65 62 40 70 62 40 70 66 40 67 70 40 67 67 40 65 62 40 70 65 40 67 65 40 70 71 40 67 66 40 66 66 40 67 70 40 67 64 40 66 71 40 70 64 40 67 65 40 67 66 40 71 60 40 70 62 40 67 71 40 70 62 40 67 64 40 67 60 40 70 65 40 65 60 40 70 64 40 66 67 40 67 61 40 67 70 40 67 67 40 70 64 40 70 63 40 70 71 40 70 62 40 70 66 40 67 71 40 65 62 40 70 71 40 70 65 40 67 65 40 67 71 40 67 66 40 67 66

很明显是八进制，直接八进制转十进制，再转ascii，可以得到如下字符串：

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

字符串经过base32解密之后可以得到：

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

然后啊，就解不出来了🤗
再回过头来看看4703张图片，不是黑色就是白色，那么可以尝试转为01二进制，白色为1，黑色为0。

# -*- coding: utf-8 -*-
# @Author  : 1cePeak

import libnum
from PIL import Image

# 指定目录路径
directory = 'pintu'  # 修改为你的目录路径

flag = ''

# 循环遍历文件名中的数字范围
for i in range(1, 4704):  # 包括1和4703
    img_file = f'{i}.png'  # 生成文件名
    img_path = f'{directory}/{img_file}'  # 生成完整文件路径

    # 打开图片
    image = Image.open(img_path)

    # 获取图片的宽度和高度
    width, height = image.size

    # 初始化一个变量来记录像素点的数量
    pixel_check = 0

    # 遍历所有像素
    for x in range(width):
        for y in range(height):
            pixel = image.getpixel((x, y))

            # 判断像素是否为白色
            if pixel == (255, 255, 255):
                pixel_check += 1

    # 如果图片中有至少有10个像素点
    flag += '1' if pixel_check > 10 else '0'

    # 关闭图片
    image.close()

print(flag)
print(libnum.b2s(flag))

得到的结果是sUvcu5rgSeAmJQCfdXtEMKIB91Lj3niOo4hyV0b/2azpx8HqZP6wk7GNlTFYDR+W
很明显是base64的表，接着之前的继续换表base64解密：

可以得到经过base64编码的图片，保存之后打开。

很明显，是之前出现过的npiet编程
使用提供的工具解密即可拿到flag

flag{4b6c1737-27e5-41c4-95e3-f70ad196063e}

2023第三届“香山杯”网络安全大赛｜pintu Writeup

pintu

2023年新疆“天山固网杯”网络安全技能竞赛｜Misc Writeup

XCTF分站赛SCTF 2023｜Misc Writeup