SimpleLogin is a forge mod aimed to protect servers in offline mode.
SimpleLogin is similar to some auth plugins in bukkit like AuthMe: the mod will check player's password when they log in.
However, there are some differences: instead of inputting the password using a command, passwords are stored in a specific file at the client-side and automatically sent to the server when the player joins, so that players don't have to input the password every time. Besides, the client will generate a random password during the first launch, so in most cases, players won't even need to do anything.
Put the simplelogin-xxx.jar into the mods directory on both server-side and client-side.
You don't need to configure anything if you don't care much.
Players' password does not need to be inputted manually, instead, the client would ask for a password when opening Multiplayer
for the first time and save it in .minecraft/.sl_password, then send it to the server when joining.
The server will remember the player's password when he joins for the first time, and when he joins later the server will check if the password matches the first one.
Is my password safe?
Sure, the password is hashed using SHA256 at the client-side and hashed using BCrypt before storing at the server-side.
However, the password is stored without any encryption at the client-side, so be careful don't
copy .minecraft/.sl_password file when sharing your client with others.
What should I do if I want to change the client?
You should backup your minecraft/.sl_password file and copy it to your new client.
There are various ways to store the user data at the server-side and each has its benefits and shortcomings. Simple Login provides an abstract layer to allow different storage implementations. Each implementation is called a "storage provider".
Each storage provider has its unique resource location (e.g. simplelogin:file) to identify itself.
Simple Login itself provides two storage providers: file and sqlite.
ResourceLocation: simplelogin:file
File storage provider is the simplest implementation of the storage provider interface, which stores all the user data
as JSON format at world/sl_entries.dat.
ResourceLocation: simplelogin:sqlite
SQLite storage provider might be more efficient than the file provider, but it needs an SQLite JDBC connector which has
roughly 6 MB and I decided not to bundle it in Simple Login. Therefore, if you want to use this provider, you'll need to
install a JDBC connector yourself. The simplest way to do that is to download it and copy org/sqlite
and META-INF/services directories into Simple Login mod jar.
If you're familiar with Java and forge mods, it won't be very hard.
You need to implement the top.seraphjack.simplelogin.server.storage.StorageProvider interface, and register your own
provider before the server starts by
calling top.seraphjack.simplelogin.server.SLRegistries.STORAGE_PROVIDERS::register.
Simple Login plugins, or plugins for short, is an extension to how Simple Login handles when players join, log in and leave the server.
Just like storage providers, each plugin has its unique resource location to identify itself.
Some key functionalities of Simple Login are also implemented as built-in plugins, and here's a list of them.
ResourceLocation: simplelogin:autosave
This plugin will trigger the Storage provider to save all data every five minutes.
This plugin is enabled by default.
ResourceLocation: simplelogin:protect_coord
This plugin will teleport players back to the spawn point before they leave the server, and teleport them back when they successfully logged in, thus prevents possible position leakage by unauthorized log-in attempts.
This plugin is disabled by default since its behavior will cause some problems when playing large modpacks.
ResourceLocation: simplelogin:resend_request
This plugin will ask the client to log in every five seconds if by some mistakes their previous log in packet unable to arrive the server.
This plugin is enabled by default.
ResourceLocation: simplelogin:restrict_game_type
This plugin will change the player's game type to spectator when they leave or join the server, and change their game type to their default game type (stored in storage providers) when then log in successfully.
This plugin is enabled by default.
ResourceLocation: simplelogin:restrict_movement
This plugin will prevent players from moving around before login.
This plugin is enabled by default.
ResourceLocation: simplelogin:timeout
This plugin will kick players who haven't authenticated after a while (default is 600 seconds, can be changed in Simple Login's
configuration in <server>/<world>/serverconfig/simplelogin-server.toml).
The timeout value used to be 60 seconds but has been increased to 600 seconds after issues with large modpacks causing the synchronization upon login to take longer than a minute.
This plugin is enabled by default.
All commands have auto-complete support.
/simplelogin unregister <PlayerName>
/simplelogin save
/simplelogin setDefaultGameType <PlayerName> <GameType>
/simplelogin about
/simplelogin plugin available
/simplelogin plugin loaded
/simplelogin plugin load <ResourceLocation>
/simplelogin plugin unload <ResourceLocation>
/simplelogin change_password <NewPassword>
secs: Integer
plugins: String Array
commandNames: String Array
/, such as give @p minecraft:apple 16storageProvider: String
defaultGameType: Integer