BUU-MISC-[*CTF2019]otaku

Posted 2021-06-19 TzZzEZ-web

[*CTF2019]otaku

第一层是个伪加密，修改加密位即可解压。

第二层加密是明文加密，将文档中隐写的部分转换成GBK编码之后使用明文破解。
（提供一段转换python脚本）

# -*- coding:GBK -*-
f = open('data.txt','w')
s = "Hello everyone, I am Gilbert. Everyone thought that I was killed, but actually I survived. Now that I have no cash with me and I’m trapped in another country. I can't contact Violet now. She must be desperate to see me and I don't want her to cry for me. I need to pay 300 for the train, and 88 for the meal. Cash or battlenet point are both accepted. I don't play the Hearthstone, and I don't even know what is Rastakhan's Rumble."
f.write(s)
f.close()

最后对图片使用zsteg分析，得到flag。