题目下载
题目名：key
提示
提取钥匙中特殊颜色的RGB循环异或KEY值
解题过程
1.提取RGB值
法1.Photoshop吸管提取
如上。先Alt+鼠标滚轮上滑放大图片，直到明显看到每个像素
然后使用吸管工具依次点击每个特殊像素，并依次在拾色器中查看每个颜色的RGB值，记录下来
####法2.Stegsolve Data Extract
使用Stegsolve打开题目图片，点击 Analyse->Data Extract，选中RGB每一位 Bit Planes，点击 Preview，找到特殊的颜色像素对应的16进制值，复制下来。
Stegsolve安装和打开的方法可参照[kali中安装使用Stegsolve](https://www.cnblogs.com/hardcoreYutian/p/10613036.html)或[内含Windows中安装使用Stegsolve](https://www.cnblogs.com/hardcoreYutian/p/11367003.html#使用工具)
###2.找到key
使用010editor或winhex（如果是汉化版可能会有乱码，建议使用英文版）查看题目图片，得到key为 ISEEU!
###3.循环异或，得到flag
注意要把RGB的6位16进制值分成3份，每两位一份，依次与 "ISEEU!" 的字符循环异或。
python代码：
```python
#2f3f24 222e13 7f6624 713645 7b7e27 723310 646721 76670c 703723 727816 7a6020 213345 7b3277 74375c
#ff2f3f24ff222e13ff7f6624 ff713645ff7b7e27ff723310ff646721 ff76670cff703723 ff727816ff7a6020 ff213345ff7b3277 ff74375c
rgb=["2f","3f","24", "22","2e","13", "7f","66","24", "71","36","45", "7b","7e","27", "72","33","10", "64","67","21", "76","67","0c", "70","37","23", "72","78","16", "7a","60","20", "21","33","45", "7b","32","77", "74","37","5c"]
key="ISEEU!"
j=0
for i in rgb:
print(chr(int(i,16)^ord(key[j])),end='')
j+=1
j%=6
```
得到flag。
##反思
软件不全，python技术过软，经学长多次指点才做出来，太菜了，欠练。