Only people who use the official PicoBrowser are allowed on this site!
So, the User-Agent header should include PicoBrowser:
curl -H "User-Agent: PicoBrowser/3.3.36" http://mercury.picoctf.net:52362/
I don't trust users visiting from another site.
Referer header:
curl -H "User-Agent: PicoBrowser/3.3.36" -H "Referer:http://mercury.picoctf.net:52362" http://mercury.picoctf.net:52362/
Sorry, this site only worked in 2018.
Date header:
curl -H "User-Agent: PicoBrowser/3.3.36" -H "Referer:http://mercury.picoctf.net:52362" -H "Date: 2018" http://mercury.picoctf.net:52362/
I don't trust users who can be tracked.
DNT (Do Not Track) header:
curl -H "User-Agent: PicoBrowser/3.3.36" -H "Referer:http://mercury.picoctf.net:52362" -H "Date: 2018" -H "DNT: 1" http://mercury.picoctf.net:52362/
This website is only for people from Sweden.
using random IP addr (example by Google) from Sweden X-Forwarded-For header:
curl -H "User-Agent: PicoBrowser/3.3.36" -H "Referer:http://mercury.picoctf.net:52362" -H "Date: 2018" -H "DNT: 1" -H "X-Forwarded-For: 151.237.181.2" http://mercury.picoctf.net:52362/
You're in Sweden but you don't speak Swedish?
Accept-Language header:
curl -H "User-Agent: PicoBrowser/3.3.36" -H "Referer:http://mercury.picoctf.net:52362" -H "Date: 2018" -H "DNT: 1" -H "X-Forwarded-For: 151.237.181.2" -H "Accept-Language:sv-SE" http://mercury.picoctf.net:52362/