2020 纵横杯 线上赛 MISC部分Writeup

文章目录

• 签到
• 马赛克
• My_Secret
• 问卷调查

签到

oct_str = '[0146, 0154, 0141, 0147, 0173, 0167, 063, 0154, 0143, 0157, 0155, 0145, 0137, 0164, 0157, 0137, 062, 0157, 0156, 0147, 0137, 0150, 063, 0156, 0147, 0137, 0142, 0145, 061, 0175]'

oct_list = oct_str.replace("[","").replace("]","").replace(",","").split(' ')
for flag in oct_list:
    print(chr(int(flag,8)),end="")

flag{w3lcome_to_2ong_h3ng_be1}

马赛克

mosaic.png

Depix：https://github.com/beurtschipper/Depix

PS D:\Tools\Misc\Depix> python .\depix.py -p .\mosaic.png -s .\images\searchimages\debruinseq_notepad_Windows10_closeAndSpaced.png -o flag.png
INFO:root:Loading pixelated image from .\mosaic.png
INFO:root:Loading search image from .\images\searchimages\debruinseq_notepad_Windows10_closeAndSpaced.png
INFO:root:Finding color rectangles from pixelated space
INFO:root:Found 93 same color rectangles
INFO:root:91 rectangles left after moot filter
INFO:root:Found 2 different rectangle sizes
INFO:root:Finding matches in search image
INFO:root:Removing blocks with no matches
INFO:root:Splitting single matches and multiple matches
INFO:root:[16 straight matches | 72 multiple matches]
INFO:root:Trying geometrical matches on single-match squares
INFO:root:[24 straight matches | 64 multiple matches]
INFO:root:Trying another pass on geometrical matches
INFO:root:[24 straight matches | 64 multiple matches]
INFO:root:Writing single match results to output
INFO:root:Writing average results for multiple matches to output
INFO:root:Saving output image to: flag.png
PS D:\Tools\Misc\Depix>

flag.png

flag{0123468abd68abd0123}

My_Secret

根据题目提示给两张图片尝试了LSB隐写，发现stego.png有隐写数据

38d668578a3686ab

01 blood and wine.wav使用DeepSound打开，密码：38d668578a3686ab

pass.txt内容为：carrier

secret.jpg使用OurSecret解密，密码：carrier

flag{2707c7a6-0680-48e9-a0ba-e200a96186ae}

问卷调查

flag{thanks_for_playing_our_games}