Add presence server (#652)

This server is responsible for one thing only, which is telling the
client to load the slot listing for any user slot you send it. Retail
LBP2 and LBP3 both implement this, but both require [special
care](https://discord.com/channels/1049223665243389953/1049225857350254632/1280019755482218588)
to make it use a separate domain (which is important if you want to
protect your main gameserver behind cloudflare!)

This is a fairly basic implementation of the server, but should be
sufficient for even large amounts of connected players.

Marking as draft until #649 is merged and hashed live play now is added,
since this branch is based off of that one (didnt wanna deal with merge
conflicts on this PR).

Thanks to aidan for figuring all this out

Example of server in action:


https://github.com/user-attachments/assets/d790a570-c291-4005-b3cf-daf6a95a9f51

Refresh.Common/Constants/EndpointRoutes.cs

@@ -0,0 +1,6 @@
+namespace Refresh.Common.Constants;
+
+public static class EndpointRoutes
+{
+    public const string PresenceBaseRoute = "/_internal/presence/";
+}

Refresh.Common/Constants/SystemUsers.cs

@@ -17,4 +17,7 @@ public static class SystemUsers
 
     public const string UnknownUserName = "!Unknown";
     public const string UnknownUserDescription = "I'm a fake user that represents a non existent publisher for re-published levels.";
+
+    public const string HashedUserName = "!Hashed";
+    public const string HashedUserDescription = "I'm a fake user that represents an unknown publisher for hashed levels.";
 }

Refresh.Common/Helpers/ResourceHelper.cs

@@ -2,6 +2,8 @@
 using System.Buffers.Binary;
 using System.IO.Compression;
 using System.Reflection;
+using System.Runtime.CompilerServices;
+using System.Runtime.InteropServices;
 using System.Security.Cryptography;
 using FastAes;
 using IronCompress;
@@ -107,4 +109,112 @@ public static byte[] PspDecrypt(Span<byte> data, ReadOnlySpan<byte> key)
         //Return a copy of the decompressed data
         return decompressed.AsSpan().ToArray();
     }
+
+    static int XXTEA_DELTA = Unsafe.BitCast<uint, int>(0x9e3779b9);
+
+    /// <summary>
+    /// In-place encrypts byte data using big endian XXTEA.
+    ///
+    /// Due to how XXTEA data works, you must pad the data to a multiple of 4 bytes.
+    /// </summary>
+    /// <param name="byteData">The data to encrypt</param>
+    /// <param name="key">The key used to encrypt the data</param>
+    /// <exception cref="ArgumentException">The input is not a multiple of 4 bytes</exception>
+    /// <remarks>
+    /// Referenced from https://github.com/ennuo/toolkit/blob/dc82bee57ab58e9f4bf35993d405529d4cbc7d00/lib/cwlib/src/main/java/cwlib/util/Crypto.java#L97
+    /// </remarks>
+    public static void XxteaEncrypt(Span<byte> byteData, Span<int> key)
+    {
+        if (byteData.Length % 4 != 0)
+            throw new ArgumentException("Data must be padded to a multiple of 4 bytes.", nameof(byteData));
+
+        // Alias the byte data as integers
+        Span<int> data = MemoryMarshal.Cast<byte, int>(byteData);
+
+        // endian swap from BE so the math happens in LE space
+        BinaryPrimitives.ReverseEndianness(data, data);
+
+        int n = data.Length - 1;
+        if (n < 1)
+        {
+            BinaryPrimitives.ReverseEndianness(data, data);
+
+            return; 
+        }
+
+        int p, q = 6 + 52 / (n + 1);
+
+        int z = data[n], y, sum = 0, e;
+        while (q-- > 0)
+        {
+            sum += XXTEA_DELTA;
+            e = sum >>> 2 & 3;
+            for (p = 0; p < n; p++)
+            {
+                y = data[p + 1];
+                z =
+                    data[p] += ((z >>> 5 ^ y << 2) + (y >>> 3 ^ z << 4) ^ (sum ^ y) + (key[p & 3 ^ e] ^ z));
+            }
+
+            y = data[0];
+            z =
+                data[n] += ((z >>> 5 ^ y << 2) + (y >>> 3 ^ z << 4) ^ (sum ^ y) + (key[p & 3 ^ e] ^ z));
+        }
+
+        // endian swap so the final data is in LE again
+        BinaryPrimitives.ReverseEndianness(data, data);
+    }
+
+    /// <summary>
+    /// In-place decrypts byte data using big endian XXTEA.
+    ///
+    /// Due to how XXTEA data works, you must pad the data to a multiple of 4 bytes.
+    /// </summary>
+    /// <param name="byteData">The data to decrypt</param>
+    /// <param name="key">The key used to decrypt the data</param>
+    /// <exception cref="ArgumentException">The input is not a multiple of 4 bytes</exception>
+    /// <remarks>
+    /// Referenced from https://github.com/ennuo/toolkit/blob/dc82bee57ab58e9f4bf35993d405529d4cbc7d00/lib/cwlib/src/main/java/cwlib/util/Crypto.java#L97
+    /// </remarks>
+    public static void XxteaDecrypt(Span<byte> byteData, Span<int> key)
+    {
+        if (byteData.Length % 4 != 0)
+            throw new ArgumentException("Data must be padded to 4 bytes.", nameof(byteData));
+
+        // Alias the byte data as integers
+        Span<int> data = MemoryMarshal.Cast<byte, int>(byteData);
+
+        // endian swap from BE so the math happens in LE space
+        BinaryPrimitives.ReverseEndianness(data, data);
+
+        int n = data.Length - 1;
+        if (n < 1)
+        {
+            BinaryPrimitives.ReverseEndianness(data, data);
+
+            return; 
+        }
+
+        int p, q = 6 + 52 / (n + 1);
+
+        int z, y = data[0], sum = q * XXTEA_DELTA, e;
+        while (sum != 0)
+        {
+            e = sum >>> 2 & 3;
+            for (p = n; p > 0; p--)
+            {
+                z = data[p - 1];
+                y = data[p] -=
+                    ((z >>> 5 ^ y << 2) + (y >>> 3 ^ z << 4) ^ (sum ^ y) + (key[p & 3 ^ e] ^ z));
+            }
+
+            z = data[n];
+            y =
+                data[0] -= ((z >>> 5 ^ y << 2) + (y >>> 3 ^ z << 4) ^ (sum ^ y) + (key[p & 3 ^ e] ^ z));
+            sum -= XXTEA_DELTA;
+        }
+
+        // endian swap so the final data is in LE again
+        BinaryPrimitives.ReverseEndianness(data, data);
+    }
 }

Refresh.GameServer/Authentication/GameAuthenticationProvider.cs

@@ -21,6 +21,10 @@ public GameAuthenticationProvider(GameServerConfig? config)
 
     public Token? AuthenticateToken(ListenerContext request, Lazy<IDatabaseContext> db)
     {
+        // Dont attempt to authenticate presence endpoints, as authentication is handled by PresenceAuthenticationMiddleware
+        if (request.Uri.AbsolutePath.StartsWith(PresenceEndpointAttribute.BaseRoute))
+            return null;
+
         // First try to grab game token data from MM_AUTH
         string? tokenData = request.Cookies["MM_AUTH"];
         TokenType tokenType = TokenType.Game;

Refresh.GameServer/Configuration/IntegrationConfig.cs

@@ -7,7 +7,7 @@ namespace Refresh.GameServer.Configuration;
 /// </summary>
 public class IntegrationConfig : Config
 {
-    public override int CurrentConfigVersion => 5;
+    public override int CurrentConfigVersion => 6;
     public override int Version { get; set; }
     protected override void Migrate(int oldVer, dynamic oldConfig)
     {
@@ -56,6 +56,16 @@ protected override void Migrate(int oldVer, dynamic oldConfig)
 
     public bool AipiRestrictAccountOnDetection { get; set; } = false;
 
+    #endregion
+
+    #region Presence
+
+    public bool PresenceEnabled { get; set; } = false;
+
+    public string PresenceBaseUrl { get; set; } = "http://localhost:10073";
+
+    public string PresenceSharedSecret { get; set; } = "SHARED_SECRET";
+
     #endregion
 
     public string? GrafanaDashboardUrl { get; set; }

Refresh.GameServer/Database/GameDatabaseContext.Users.cs

@@ -455,4 +455,12 @@ public void SetUserRootPlaylist(GameUser user, GamePlaylist playlist)
             user.RootPlaylist = playlist;
         });
     }
+
+    public void SetUserPresenceAuthToken(GameUser user, string? token)
+    {
+        this.Write(() =>
+        {
+            user.PresenceServerAuthToken = token;
+        });
+    }
 }

Refresh.GameServer/Database/GameDatabaseProvider.cs

@@ -34,7 +34,7 @@ protected GameDatabaseProvider(IDateTimeProvider time)
         this._time = time;
     }
 
-    protected override ulong SchemaVersion => 156;
+    protected override ulong SchemaVersion => 159;
 
     protected override string Filename => "refreshGameServer.realm";
 

Refresh.GameServer/Endpoints/ApiV3/DataTypes/Response/Users/ApiExtendedGameUserResponse.cs

@@ -46,8 +46,9 @@ public class ApiExtendedGameUserResponse : IApiResponse, IDataConvertableFrom<Ap
 
     public required ApiGameUserStatisticsResponse Statistics { get; set; }
     public required ApiGameRoomResponse? ActiveRoom { get; set; }
+    public required bool ConnectedToPresenceServer { get; set; }
 
-    [ContractAnnotation("null => null; notnull => notnull")]
+    [ContractAnnotation("user:null => null; user:notnull => notnull")]
     public static ApiExtendedGameUserResponse? FromOld(GameUser? user, DataContext dataContext)
     {
         if (user == null) return null;
@@ -77,6 +78,7 @@ public class ApiExtendedGameUserResponse : IApiResponse, IDataConvertableFrom<Ap
             LevelVisibility = user.LevelVisibility,
             ProfileVisibility = user.ProfileVisibility,
             ShowModdedContent = user.ShowModdedContent,
+            ConnectedToPresenceServer = user.PresenceServerAuthToken != null,
         };
     }
 

Refresh.GameServer/Endpoints/ApiV3/LevelApiEndpoints.cs

@@ -11,6 +11,7 @@
 using Refresh.GameServer.Endpoints.ApiV3.ApiTypes.Errors;
 using Refresh.GameServer.Endpoints.ApiV3.DataTypes.Request;
 using Refresh.GameServer.Endpoints.ApiV3.DataTypes.Response.Levels;
+using Refresh.GameServer.Endpoints.Game.DataTypes.Response;
 using Refresh.GameServer.Endpoints.Game.Levels.FilterSettings;
 using Refresh.GameServer.Extensions;
 using Refresh.GameServer.Services;
@@ -144,13 +145,17 @@ public ApiOkResponse DeleteLevelById(RequestContext context, GameDatabaseContext
     [ApiV3Endpoint("levels/id/{id}/setAsOverride", HttpMethods.Post)]
     [DocSummary("Marks the level to show in the next slot list gotten from the game")]
     [DocError(typeof(ApiNotFoundError), ApiNotFoundError.LevelMissingErrorWhen)]
-    public ApiOkResponse SetLevelAsOverrideById(RequestContext context, GameDatabaseContext database, GameUser user, LevelListOverrideService service,
+    public ApiOkResponse SetLevelAsOverrideById(RequestContext context, 
+        GameDatabaseContext database, 
+        GameUser user, 
+        PlayNowService overrideService,
         [DocSummary("The ID of the level")] int id)
     {
         GameLevel? level = database.GetLevelById(id);
         if (level == null) return ApiNotFoundError.LevelMissingError;
-
-        service.AddIdOverridesForUser(user, level);
+
+        // TODO: return whether or not the presence server was used
+        overrideService.PlayNowLevel(user, level);
 
         return new ApiOkResponse();
     }
@@ -159,12 +164,13 @@ public ApiOkResponse SetLevelAsOverrideById(RequestContext context, GameDatabase
     [DocSummary("Marks the level hash to show in the next slot list gotten from the game")]
     [DocError(typeof(ApiValidationError), ApiValidationError.HashInvalidErrorWhen)]
     public ApiOkResponse SetLevelAsOverrideByHash(RequestContext context, GameDatabaseContext database, GameUser user,
-        LevelListOverrideService service, [DocSummary("The hash of level root resource")] string hash)
+        PlayNowService service, PresenceService presenceService, [DocSummary("The hash of level root resource")] string hash)
     {
         if (!CommonPatterns.Sha1Regex().IsMatch(hash)) 
             return ApiValidationError.HashInvalidError;
-
-        service.AddHashOverrideForUser(user, hash);
+
+        // TODO: return whether presence/hash play now was used
+        service.PlayNowHash(user, hash);
 
         return new ApiOkResponse();
     }

Refresh.GameServer/Endpoints/Game/DataTypes/Response/GameLevelResponse.cs

@@ -110,7 +110,7 @@ public static GameLevelResponse FromHash(string hash, DataContext dataContext)
             Location = new GameLocation(),
             Handle = new SerializedUserHandle
             {
-                Username = $"!Hashed",
+                Username = SystemUsers.HashedUserName,
                 IconHash = "0",
             },
             Type = GameSlotType.User.ToGameType(),

Refresh.GameServer/Endpoints/Game/Handshake/AuthenticationEndpoints.cs

@@ -166,9 +166,12 @@ public class AuthenticationEndpoints : EndpointGroup
 
         Token token = database.GenerateTokenForUser(user, TokenType.Game, game.Value, platform.Value, context.RemoteIp(), GameDatabaseContext.GameTokenExpirySeconds); // 4 hours
 
-        //Clear the user's force match
+        // Clear the user's force match
         database.ClearForceMatch(user);
 
+        // Mark the user as disconnected from the presence server
+        database.SetUserPresenceAuthToken(user, null);
+
         context.Logger.LogInfo(BunkumCategory.Authentication, $"{user} successfully logged in on {game} via {platform}");
 
         if (game == TokenGame.LittleBigPlanetPSP)
@@ -278,6 +281,8 @@ public Response RevokeThisToken(RequestContext context, GameDatabaseContext data
 
         // Revoke the token
         database.RevokeToken(token);
+        // Mark them as disconnected from the presence server
+        database.SetUserPresenceAuthToken(user, null);
 
         context.Logger.LogInfo(BunkumCategory.Authentication, $"{user} logged out");
         return OK;

Refresh.GameServer/Endpoints/Game/Levels/LevelEndpoints.cs

@@ -1,8 +1,8 @@
 using Bunkum.Core;
 using Bunkum.Core.Endpoints;
-using Bunkum.Core.Endpoints.Debugging;
 using Bunkum.Core.Storage;
 using Bunkum.Listener.Protocol;
+using Refresh.Common.Constants;
 using Refresh.GameServer.Authentication;
 using Refresh.GameServer.Database;
 using Refresh.GameServer.Endpoints.Game.DataTypes.Response;
@@ -26,7 +26,7 @@ public class LevelEndpoints : EndpointGroup
     public SerializedMinimalLevelList? GetLevels(RequestContext context,
         GameDatabaseContext database,
         CategoryService categoryService,
-        LevelListOverrideService overrideService,
+        PlayNowService overrideService,
         GameUser user,
         Token token,
         DataContext dataContext,
@@ -47,7 +47,7 @@ public class LevelEndpoints : EndpointGroup
 
         // If we are getting the levels by a user, and that user is "!Hashed", then we pull that user's overrides
         if (route == "by" 
-            && (context.QueryString.Get("u") == "!Hashed" || user.Username == "!Hashed") 
+            && (context.QueryString.Get("u") == SystemUsers.HashedUserName || user.Username == SystemUsers.HashedUserName) 
             && overrideService.GetLastHashOverrideForUser(token, out string hash))
         {
             return new SerializedMinimalLevelList
@@ -101,7 +101,7 @@ public class LevelEndpoints : EndpointGroup
     public SerializedMinimalLevelList? GetLevelsWithPlayer(RequestContext context,
         GameDatabaseContext database,
         CategoryService categories,
-        LevelListOverrideService overrideService,
+        PlayNowService overrideService,
         Token token,
         DataContext dataContext,
         string route,
@@ -118,7 +118,7 @@ public class LevelEndpoints : EndpointGroup
     [MinimumRole(GameUserRole.Restricted)]
     public GameLevelResponse? LevelById(RequestContext context, GameDatabaseContext database, Token token,
         string slotType, int id,
-        LevelListOverrideService overrideService, DataContext dataContext)
+        PlayNowService overrideService, DataContext dataContext)
     {
         // If the user has had a hash override in the past, and the level id they requested matches the level ID associated with that hash
         if (overrideService.GetLastHashOverrideForUser(token, out string hash) && GameLevelResponse.LevelIdFromHash(hash) == id)
@@ -204,7 +204,7 @@ public SerializedMinimalLevelResultsList GetLevelsFromCategory(RequestContext co
         GameDatabaseContext database,
         CategoryService categories,
         MatchService matchService,
-        LevelListOverrideService overrideService,
+        PlayNowService overrideService,
         GameUser user,
         IDataStore dataStore,
         Token token,
@@ -218,7 +218,7 @@ public SerializedMinimalLevelResultsList GetLevelsFromCategory(RequestContext co
         GameDatabaseContext database,
         CategoryService categories,
         MatchService matchService,
-        LevelListOverrideService overrideService,
+        PlayNowService overrideService,
         Token token,
         IDataStore dataStore,
         DataContext dataContext,