HGAME 2022 Writeup

2023-09-29 20:16:40

文章目录

Level - Week1

新人赛，就没有存题目附件了，简单的记录一下解题过程吧

Level - Week1

WEB

easy_auth

存在admin用户，随便设置一个任务，然后点击doing，抓一个GET的包

Token的格式很明显是jwt：https://jwt.io/

修改ID为1，Username为admin
发送修改后的jwt密文得到flag

蛛蛛…嘿嘿♥我的蛛蛛

import requests
import re

init_url = "https://hgame-spider.vidar.club/8983cb3acd"
link = ""

while True:
	res_url = init_url + link
	regex = re.compile('href="(.*?)"')
	html = requests.get(url=res_url)
	l = re.findall(regex, html.text)
	print(res_url)
	link = [i for i in l if i != '']
	if len(link) == 0:
		break
	else:
		link = link[0]

访问最后一个输出的地址，flag在响应头里面

Tetris plus

在cheking.js中发现注释了jsfuck

直接复制到控制台回车即可得到flag

Fujiwara Tofu Shop

GET / HTTP/1.1
Host: shop.summ3r.top
User-Agent: Hachi-Roku
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,*/*;q=0.8
Accept-Language: zh-CN,zh;q=0.8,zh-TW;q=0.7,zh-HK;q=0.5,en-US;q=0.3,en;q=0.2
Accept-Encoding: gzip, deflate
referer:qiumingshan.net
Cookie: flavor=Raspberry;
gasoline:100
x-real-ip:127.0.0.1
Connection: close
Upgrade-Insecure-Requests: 1
Cache-Control: max-age=0

MISC

欢迎欢迎！热烈欢迎！

hgame{We1com3_t0_HG@ME_2O22}

这个压缩包有点麻烦

README.txt

I don't know if it's a good idea to write down all the passwords.

将password-note.txt作为字典进行爆破

明文攻击

分离出来的压缩包跟一般伪加密不同的是修改了压缩源文件数据区的全局方式标记位，使得7z等压缩包无法无视伪加密直接解压

修改压缩源文件目录区全局方式标记位为偶数即可

hgame{W0w!_y0U_Kn0w_z1p_3ncrYpt!}

好康的流量

https://the-x.cn/zh-cn/base64/

hgame{ez_1mg_

另一半flag用zsteg查看一下LSB

hgame{ez_1mg_Steg4n0graphy}

群青(其实是幽灵东京）

通过频谱图得到密码：Yoasobi

音频LSB隐写，SlientEye解码得到一个地址

https://potat0-1308188104.cos.ap-shanghai.myqcloud.com/Week1/S_S_T_V.wav

听起来是SSTV，Robot36直接听

hgame{1_c4n_5ee_the_wav}

CRYPTO

Dancing Line

向X轴方向移动一个像素点记为0，向Y轴方向移动一个像素点记为1

from PIL import Image

img = Image.open('flag.bmp')
width, height = img.size
bin_data = ''
num_list = []
n = 0
for w in range(width):
	for h in range(height):
		pix = img.getpixel((w,h))
		if pix != (255, 255, 255):
			#print("{} {}".format(pix, n))
			num_list.append(n)
		n += 1
for i in range(len(num_list)-1):
	if (num_list[i+1] - num_list[i]) >= height:
		bin_data += '0'
	else:
		bin_data += '1'
print("[+]binary data: {}".format(bin_data))
flag = ''
for i in range(0, len(bin_data), 8):
	flag += chr(int(bin_data[i:i+8], 2))
print(flag)

PS C:\Users\Administrator\Downloads> python .\code.py
[+]binary data: 01101000011001110110000101101101011001010111101101000100011000010110111001100011001100010110111001100111010111110100110000110001011011100110010101011111001100010011010101011111011001100111010101101110001011000101111100110001001101010110111000100111011101000101111100110001011101000011111101111101
hgame{Danc1ng_L1ne_15_fun,_15n't_1t?}

Matryoshka

类似盲文，但是其实是摩斯码

将⠨替换为.
将⠤替换为-
将⠌替换为/

然后逆序处理

http://www.zhongguosou.com/zonghe/moErSiCodeConverter.aspx
摩斯转换得到Hex码

466642756645466E6D4C73364433736959744C3658327034694E306364536C796B6D3972514E396F4D53316A6B7339724B3252366B4C38686F72303D

Hex转字符得到：
FfBufEFnmLs6D3siYtL6X2p4iN0cdSlykm9rQN9oMS1jks9rK2R6kL8hor0=

维吉尼亚解密(密钥为：hgame)得到：
YzBibXZnaHl6X3swUmF6X2d4eG0wdGhrem9fMG9iMG1fdm9rY2N6dF8hcn0=

base64解码得到：
c0bmvghyz_{0Raz_gxxm0thkzo_0ob0m_vokcczt_!r}

栅栏密码(每组字数：22)得到：
cbvhz{Rzgx0hz_o0_ocz_r0mgy_0a_xmtko0bmvkct!}

凯撒密码解密(位移21)得到：
hgame{Welc0me_t0_the_w0rld_0f_crypt0graphy!}

English Novel

根据给出的密文，明文，以及加密算法，推出key，然后利用key解flag.enc

import os

def if_length(ori_content, enc_content, match_result):
	if len(ori_content) == len(enc_content):
		match_result = True
	else:
		match_result = False
	return match_result

def if_match(ori_name, enc_name):
	match_result = True
	ori_path = ori_folder + '/' + ori_name
	enc_path = enc_folder + '/' + enc_name
	with open(ori_path, 'r') as f:
		ori_content = f.read()
	with open(enc_path, 'r') as f:
		enc_content = f.read()
	match_result = True
	if match_result:
		match_result = if_length(ori_content, enc_content, match_result)
		if match_result:
			for i in range(len(ori_content)):
				if ori_content[i] == enc_content[i]:
					continue
				elif ori_content[i].isupper() and enc_content[i].isupper():
					continue
				elif ori_content[i].islower() and enc_content[i].islower():
					continue
				else:
					match_result = False
	return match_result

def match_process(ori_folder, enc_folder):
	all_match = []
	original_list = os.listdir(ori_folder)
	encrypt_list = os.listdir(enc_folder)
	for ori_name in original_list:
		for enc_name in encrypt_list:
			match_result = if_match(ori_name, enc_name)
			if match_result:
				ori_path = ori_folder + '/' + ori_name
				enc_path = enc_folder + '/' + enc_name
				match_group = [ori_path, enc_path]
				all_match.append(match_group)
				encrypt_list.remove(enc_name)
			else:
				continue
	return all_match

def decrypt(ori_data, enc_data, enc_flag):
	keys = []
	for i in range(len(enc_data)):
		key = ord(enc_data[i]) - ord(ori_data[i])
		keys.append(key)
	result = ""
	enc_data = enc_flag
	for i in range(len(enc_data)):
		if enc_data[i].isupper():
			result += chr((ord(enc_data[i]) - ord('A') - keys[i]) % 26 + ord('A'))
		elif enc_data[i].islower():
			result += chr((ord(enc_data[i]) - ord('a') - keys[i]) % 26 + ord('a'))
		else:
			result += enc_data[i]
	return result

if __name__ == '__main__':
	ori_folder = './original'
	enc_folder = './encrypt'
	enc_flag = open('./flag.enc', 'r').read()
	match_list = match_process(ori_folder, enc_folder)
	for match_group in match_list:
		with open(match_group[0], 'r') as f:
			ori_data = f.read()
		with open(match_group[1], 'r') as f:
			enc_data = f.read()
		flag = decrypt(ori_data, enc_data, enc_flag)
		print("{:<30}{:<30}{:<30}".format(match_group[0], match_group[1], flag))

hgame{D0_y0u_kn0w_'Kn0wn-pla1ntext_attack'?}

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