Added option to "lock" server using global password. Users won't be able to register.

src/main/java/org/samo_lego/simpleauth/SimpleAuth.java

@@ -6,6 +6,8 @@ import net.fabricmc.fabric.api.event.server.ServerStopCallback;
 import net.fabricmc.fabric.api.registry.CommandRegistry;
 import net.minecraft.entity.player.PlayerEntity;
 import net.minecraft.server.network.ServerPlayerEntity;
+import net.minecraft.text.LiteralText;
+import net.minecraft.text.Text;
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
 import org.samo_lego.simpleauth.commands.*;
@@ -31,7 +33,6 @@ public class SimpleAuth implements DedicatedServerModInitializer {
 	// Mod config
 	public static AuthConfig config;
 
-
 	@Override
 	public void onInitializeServer() {
 		// Info I guess :D
@@ -76,4 +77,11 @@ public class SimpleAuth implements DedicatedServerModInitializer {
 		LOGGER.info("[SimpleAuth] Shutting down SimpleAuth.");
 		db.close();
 	}
+	public static void authenticatePlayer(ServerPlayerEntity player, Text msg) {
+		SimpleAuth.deauthenticatedUsers.remove(player);
+		// Player no longer needs to be invisible and invulnerable
+		player.setInvulnerable(false);
+		player.setInvisible(false);
+		player.sendMessage(msg);
+	}
 }

src/main/java/org/samo_lego/simpleauth/commands/AuthCommand.java

@@ -24,6 +24,7 @@ public class AuthCommand {
     private static Text userdataDeleted = new LiteralText(SimpleAuth.config.lang.userdataDeleted);
     private static Text userdataUpdated = new LiteralText(SimpleAuth.config.lang.userdataUpdated);
     private static Text configurationReloaded = new LiteralText(SimpleAuth.config.lang.configurationReloaded);
+    private static Text globalPasswordSet = new LiteralText(SimpleAuth.config.lang.globalPasswordSet);
 
     public static void registerCommand(CommandDispatcher<ServerCommandSource> dispatcher) {
         // Registering the "/auth" command
@@ -32,6 +33,14 @@ public class AuthCommand {
             .then(literal("reload")
                 .executes( ctx -> reloadConfig(ctx.getSource()))
             )
+            .then(literal("setGlobalPassword")
+                    .then(argument("password", word())
+                            .executes( ctx -> setGlobalPassword(
+                                    ctx.getSource(),
+                                    getString(ctx, "password")
+                            ))
+                    )
+            )
             .then(literal("update")
                 .then(literal("byUuid")
                     .then(argument("uuid", word())
@@ -80,6 +89,20 @@ public class AuthCommand {
             )
         );
     }
+    private static int setGlobalPassword(ServerCommandSource source, String pass) {
+        // Getting the player who send the command
+        Entity sender = source.getEntity();
+        // Writing the global pass to config
+        SimpleAuth.config.main.globalPassword = AuthHelper.hashPass(pass.toCharArray());
+        SimpleAuth.config.save(new File("./mods/SimpleAuth/config.json"));
+
+        if(sender != null)
+            sender.sendMessage(globalPasswordSet);
+        else
+            LOGGER.info(globalPasswordSet);
+        return 1;
+    }
+
 
     // Method called for checking the password
     private static int updatePass(ServerCommandSource source, String uuid, String username, String pass) {

src/main/java/org/samo_lego/simpleauth/commands/LoginCommand.java

@@ -18,7 +18,7 @@ public class LoginCommand {
     private static Text enterPassword = new LiteralText(SimpleAuth.config.lang.enterPassword);
     private static Text wrongPassword = new LiteralText(SimpleAuth.config.lang.wrongPassword);
     private static Text alreadyAuthenticated = new LiteralText(SimpleAuth.config.lang.alreadyAuthenticated);
-    private static Text loginTriesExceeded = new LiteralText("§4Too many login tries.");
+    //private static Text loginTriesExceeded = new LiteralText("§4Too many login tries.");
     private static Text successfullyAuthenticated = new LiteralText(SimpleAuth.config.lang.successfullyAuthenticated);
 
     public static void registerCommand(CommandDispatcher<ServerCommandSource> dispatcher) {
@@ -37,16 +37,16 @@ public class LoginCommand {
     private static int login(ServerCommandSource source, String pass) throws CommandSyntaxException {
         // Getting the player who send the command
         ServerPlayerEntity player = source.getPlayer();
-        if(SimpleAuth.isAuthenticated(player)) {
+        if(SimpleAuth.config.main.enableGlobalPassword && AuthHelper.checkPass("globalPass", pass.toCharArray())) {
+            SimpleAuth.authenticatePlayer(player, successfullyAuthenticated);
+            return 1;
+        }
+        else if(SimpleAuth.isAuthenticated(player)) {
             player.sendMessage(alreadyAuthenticated);
             return 0;
         }
         else if (AuthHelper.checkPass(player.getUuidAsString(), pass.toCharArray())) {
-            SimpleAuth.deauthenticatedUsers.remove(player);
+            SimpleAuth.authenticatePlayer(player, successfullyAuthenticated);
-            // Player no longer needs to be invisible and invulnerable
-            player.setInvulnerable(false);
-            player.setInvisible(false);
-            player.sendMessage(successfullyAuthenticated);
             return 1;
         }
         player.networkHandler.disconnect(wrongPassword);

src/main/java/org/samo_lego/simpleauth/commands/RegisterCommand.java

@@ -7,6 +7,7 @@ import net.minecraft.server.network.ServerPlayerEntity;
 import net.minecraft.text.LiteralText;
 import net.minecraft.text.Text;
 import org.samo_lego.simpleauth.SimpleAuth;
+import org.samo_lego.simpleauth.utils.AuthConfig;
 import org.samo_lego.simpleauth.utils.AuthHelper;
 
 import static com.mojang.brigadier.arguments.StringArgumentType.getString;
@@ -21,6 +22,7 @@ public class RegisterCommand {
     private static Text alreadyRegistered = new LiteralText(SimpleAuth.config.lang.alreadyRegistered);
     private static Text registerSuccess = new LiteralText(SimpleAuth.config.lang.registerSuccess);
     private static Text matchPass = new LiteralText( SimpleAuth.config.lang.matchPassword);
+    private static Text globalPasswordRequired = new LiteralText( SimpleAuth.config.lang.globalPasswordRequired);
 
     public static void registerCommand(CommandDispatcher<ServerCommandSource> dispatcher) {
 
@@ -39,18 +41,18 @@ public class RegisterCommand {
     // Method called for hashing the password & writing to DB
     private static int register(ServerCommandSource source, String pass1, String pass2) throws CommandSyntaxException {
         ServerPlayerEntity player = source.getPlayer();
-        if(SimpleAuth.isAuthenticated(player)) {
+        if(SimpleAuth.config.main.enableGlobalPassword) {
+            player.sendMessage(globalPasswordRequired);
+            return 0;
+        }
+        else if(SimpleAuth.isAuthenticated(player)) {
             player.sendMessage(alreadyAuthenticated);
             return 0;
         }
         else if(pass1.equals(pass2)) {
             String hash = AuthHelper.hashPass(pass1.toCharArray());
             if (SimpleAuth.db.registerUser(player.getUuidAsString(), source.getName(), hash)) {
-                SimpleAuth.deauthenticatedUsers.remove(player);
+                SimpleAuth.authenticatePlayer(player, registerSuccess);
-                // Player no longer needs to be invisible and invulnerable
-                player.setInvulnerable(false);
-                player.setInvisible(false);
-                player.sendMessage(registerSuccess);
                 return 1;
             }
             player.sendMessage(alreadyRegistered);

src/main/java/org/samo_lego/simpleauth/event/AuthEventHandler.java

@@ -2,6 +2,7 @@ package org.samo_lego.simpleauth.event;
 
 import net.minecraft.entity.player.PlayerEntity;
 import net.minecraft.item.ItemStack;
+import net.minecraft.nbt.CompoundTag;
 import net.minecraft.server.network.ServerPlayerEntity;
 import net.minecraft.server.network.packet.ChatMessageC2SPacket;
 import net.minecraft.text.TranslatableText;
@@ -24,6 +25,9 @@ public class AuthEventHandler {
     // Player joining the server
     public static void onPlayerJoin(ServerPlayerEntity player) {
         SimpleAuth.deauthenticatedUsers.add(player);
+        CompoundTag tag = new CompoundTag();
+        tag.putInt("loginTries", 0);
+        player.writeCustomDataToTag(tag);
         // Player not authenticated
         // If clause actually not needed, since we add player to deauthenticated hashset above
         if (!SimpleAuth.isAuthenticated(player)) {

src/main/java/org/samo_lego/simpleauth/utils/AuthConfig.java

@@ -52,6 +52,13 @@ public class AuthConfig {
         public boolean playerInvisible = true;
         // Time after which player will be kicked if not authenticated - in seconds
         public int delay = 60;
+        // Disables registering and forces logging in with global password
+        public boolean enableGlobalPassword = false;
+        /* If above is true, the global password can be set with command:
+        `/auth setGlobalPassword <pass>`
+        Password will be hashed and saved.
+         */
+        public String globalPassword = null;
     }
     public static class LangConfig {
         public String enterPassword = "§6You need to enter your password!";
@@ -59,6 +66,8 @@ public class AuthConfig {
         public String wrongPassword = "§4Wrong password!";
         public String matchPassword = "§6Passwords must match!";
         public String passwordUpdated = "§4Your password was updated successfully!";
+        public String globalPasswordRequired = "§4Use /login <global password> to authenticate!";
+        public String globalPasswordSet = "§aGlobal password was successfully set!";
         public String notAuthenticated = "§cYou are not authenticated!\n§6Try with /login or /register.";
         public String alreadyAuthenticated = "§4You are already authenticated.";
         public String successfullyAuthenticated = "§aYou are now authenticated.";
@@ -94,7 +103,7 @@ public class AuthConfig {
 
         return config;
     }
-    private void save(File file) {
+    public void save(File file) {
         try (FileWriter writer = new FileWriter(file)) {
             gson.toJson(this, writer);
         } catch (IOException e) {

src/main/java/org/samo_lego/simpleauth/utils/AuthHelper.java

@@ -13,12 +13,26 @@ public class AuthHelper {
     private static Argon2 argon2 = Argon2Factory.create();
 
     public static boolean checkPass(String uuid, char[] pass) {
+        if(uuid.equals("globalPass") && SimpleAuth.config.main.enableGlobalPassword) {
+            // We have global password enabled
+            try {
+                return argon2.verify(SimpleAuth.config.main.globalPassword, pass);
+            }
+            catch (Error e) {
+                LOGGER.error("[SimpleAuth] Argon2 error: " + e);
+                return false;
+            } finally {
+                // Wipe confidential data
+                argon2.wipeArray(pass);
+            }
+        }
+        else {
             try {
                 // Hashed password from DB
                 String hashed = SimpleAuth.db.getPassword(uuid);
                 // Verify password
                 return argon2.verify(hashed, pass);
-        } catch(Error e) {
+            } catch (Error e) {
                 LOGGER.error("[SimpleAuth] error: " + e);
                 return false;
             } finally {
@@ -26,6 +40,7 @@ public class AuthHelper {
                 argon2.wipeArray(pass);
             }
         }
+    }
     // Hashing the password with the Argon2 power
     public static String hashPass(char[] pass) {
         try {