LetMeIn

NeoForge mod that lets you protect your offline mode server adding client-side password editor instead of using traditional /register or /login.

What to do before logging in

Mods -> LetMeIn -> Config -> Type in your password (16 characters)

How to change password

Server folder -> config -> letmein -> remove UUID and hash of player that wants to change password

(you can find UUID to username table in usernamecache.json file)

How does it work

During the configuration phase server asks for your password hash and compares it to what it has, if it doesnt have one then it registers it in the server_config.json, if the password is wrong you get kicked before entering the world.

Should be pretty obvious that it is requred to be installed both on client and on the server