Add handbook IP authentication in hybrid mode

src/main/java/emu/grasscutter/auth/DefaultAuthenticators.java

@@ -1,10 +1,8 @@
 package emu.grasscutter.auth;
 
-import static emu.grasscutter.config.Configuration.ACCOUNT;
-import static emu.grasscutter.utils.Language.translate;
-
 import at.favre.lib.crypto.bcrypt.BCrypt;
 import emu.grasscutter.Grasscutter;
+import emu.grasscutter.Grasscutter.ServerRunMode;
 import emu.grasscutter.auth.AuthenticationSystem.AuthenticationRequest;
 import emu.grasscutter.database.DatabaseHelper;
 import emu.grasscutter.game.Account;
@@ -16,13 +14,17 @@ import emu.grasscutter.utils.DispatchUtils;
 import emu.grasscutter.utils.FileUtils;
 import emu.grasscutter.utils.Utils;
 import io.javalin.http.ContentType;
+
+import javax.crypto.Cipher;
 import java.nio.charset.StandardCharsets;
 import java.security.KeyFactory;
 import java.security.interfaces.RSAPrivateKey;
 import java.security.spec.PKCS8EncodedKeySpec;
 import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.TimeUnit;
-import javax.crypto.Cipher;
+
+import static emu.grasscutter.config.Configuration.ACCOUNT;
+import static emu.grasscutter.utils.Language.translate;
 
 /** A class containing default authenticators. */
 public final class DefaultAuthenticators {
@@ -392,6 +394,24 @@ public final class DefaultAuthenticators {
             var ctx = request.getContext();
             if (ctx == null) return;
 
+            // Check to see if an IP authentication can be performed.
+            if (Grasscutter.getRunMode() == ServerRunMode.HYBRID) {
+                var player = Grasscutter.getGameServer()
+                    .getPlayerByIpAddress(ctx.ip());
+                if (player != null) {
+                    // Get the player's session token.
+                    var sessionKey = player.getAccount().getSessionKey();
+                    // Respond with the handbook auth page.
+                    ctx.status(200).result(
+                        this.authPage
+                            .replace("{{VALUE}}", "true")
+                            .replace("{{SESSION_TOKEN}}", sessionKey)
+                            .replace("{{PLAYER_ID}}", String.valueOf(player.getUid()))
+                    );
+                    return;
+                }
+            }
+
             // Respond with the handbook auth page.
             ctx.contentType(ContentType.TEXT_HTML).result(this.authPage);
         }

src/main/java/emu/grasscutter/server/game/GameServer.java

@@ -1,9 +1,5 @@
 package emu.grasscutter.server.game;
 
-import static emu.grasscutter.config.Configuration.DISPATCH_INFO;
-import static emu.grasscutter.config.Configuration.GAME_INFO;
-import static emu.grasscutter.utils.Language.translate;
-
 import emu.grasscutter.GameConstants;
 import emu.grasscutter.Grasscutter;
 import emu.grasscutter.Grasscutter.ServerRunMode;
@@ -41,17 +37,22 @@ import emu.grasscutter.server.event.internal.ServerStopEvent;
 import emu.grasscutter.server.event.types.ServerEvent;
 import emu.grasscutter.server.scheduler.ServerTaskScheduler;
 import emu.grasscutter.task.TaskMap;
+import kcp.highway.ChannelConfig;
+import kcp.highway.KcpServer;
+import lombok.Getter;
+import lombok.Setter;
+import lombok.SneakyThrows;
+
 import java.net.InetSocketAddress;
 import java.net.URI;
 import java.time.Instant;
 import java.time.OffsetDateTime;
 import java.util.*;
 import java.util.concurrent.ConcurrentHashMap;
-import kcp.highway.ChannelConfig;
+
-import kcp.highway.KcpServer;
+import static emu.grasscutter.config.Configuration.DISPATCH_INFO;
-import lombok.Getter;
+import static emu.grasscutter.config.Configuration.GAME_INFO;
-import lombok.Setter;
+import static emu.grasscutter.utils.Language.translate;
-import lombok.SneakyThrows;
 
 @Getter
 public final class GameServer extends KcpServer {
@@ -246,6 +247,21 @@ public final class GameServer extends KcpServer {
         return playerOpt.orElse(null);
     }
 
+    /**
+     * Tries to find a player with the matching IP address.
+     *
+     * @param ipAddress The IP address. This should just be numbers without a port.
+     * @return The player, or null if one could not be found.
+     */
+    public Player getPlayerByIpAddress(String ipAddress) {
+        return this.getPlayers().values().stream()
+            .map(Player::getSession)
+            .filter(session -> session != null &&
+                session.getAddress().getHostString().equals(ipAddress))
+            .map(GameSession::getPlayer)
+            .findFirst().orElse(null);
+    }
+
     public SocialDetail.Builder getSocialDetailByUid(int id) {
         // Get from online players
         Player player = this.getPlayerByUid(id, true);