Inverted boolean for syncshells

Specified branch to omit errors on pulling submodules

.gitmodules

@@ -1,3 +1,4 @@
 [submodule "LightlessAPI"]
 	path = LightlessAPI
 	url = https://git.lightless-sync.org/Lightless-Sync/LightlessAPI
+	branch = main

LightlessSyncServer/LightlessSyncServer/Configuration/BroadcastConfiguration.cs

@@ -59,6 +59,14 @@ public class BroadcastConfiguration : IBroadcastConfiguration
         return string.Concat(RedisKeyPrefix, hashedCid);
     }
 
+    public string BuildUserOwnershipKey(string userUid)
+    {
+        if (string.IsNullOrWhiteSpace(userUid))
+            throw new ArgumentException("User UID must not be null or empty.", nameof(userUid));
+
+        return string.Concat(RedisKeyPrefix, "owner:", userUid);
+    }
+
     public string BuildPairRequestNotification()
     {
         var template = Options.PairRequestNotificationTemplate;
@@ -69,4 +77,7 @@ public class BroadcastConfiguration : IBroadcastConfiguration
 
         return template;
     }
+
+    public int PairRequestRateLimit => Options.PairRequestRateLimit > 0 ? Options.PairRequestRateLimit : 5;
+    public int PairRequestRateWindow => Options.PairRequestRateWindow > 0 ? Options.PairRequestRateWindow : 60;
 }

LightlessSyncServer/LightlessSyncServer/Configuration/BroadcastOptions.cs

@@ -20,4 +20,10 @@ public class BroadcastOptions
     public bool EnableSyncshellBroadcastPayloads { get; set; } = true;
 
     public string PairRequestNotificationTemplate { get; set; } = "{DisplayName} sent you a pair request. To accept, right-click them, open the context menu, and send a request back.";
+
+    [Range(1, int.MaxValue)]
+    public int PairRequestRateLimit { get; set; } = 5;
+
+    [Range(1, int.MaxValue)]
+    public int PairRequestRateWindow { get; set; } = 60;
 }

LightlessSyncServer/LightlessSyncServer/Configuration/IBroadcastConfiguration.cs

@@ -12,5 +12,9 @@ public interface IBroadcastConfiguration
     bool EnableSyncshellBroadcastPayloads { get; }
 
     string BuildRedisKey(string hashedCid);
+    string BuildUserOwnershipKey(string userUid);
     string BuildPairRequestNotification();
+
+    int PairRequestRateLimit { get; }
+    int PairRequestRateWindow { get; }
 }

LightlessSyncServer/LightlessSyncServer/Hubs/LightlessHub.Functions.cs

@@ -1,11 +1,13 @@
-using LightlessSyncShared.Models;
-using Microsoft.EntityFrameworkCore;
-using LightlessSyncServer.Utils;
-using LightlessSyncShared.Utils;
 using LightlessSync.API.Data;
 using LightlessSync.API.Dto.Group;
+using LightlessSyncServer.Utils;
 using LightlessSyncShared.Metrics;
+using LightlessSyncShared.Models;
+using LightlessSyncShared.Utils;
 using Microsoft.AspNetCore.SignalR;
+using Microsoft.EntityFrameworkCore;
+using StackExchange.Redis;
+using System.Text.Json;
 using System.Threading;
 
 namespace LightlessSyncServer.Hubs;
@@ -95,13 +97,18 @@ public partial class LightlessHub
 
     private async Task RemoveUserFromRedis()
     {
+        if (IsValidHashedCid(UserCharaIdent))
+        {
+            await _redis.RemoveAsync("CID:" + UserCharaIdent, StackExchange.Redis.CommandFlags.FireAndForget).ConfigureAwait(false);
+        }
+
         await _redis.RemoveAsync("UID:" + UserUID, StackExchange.Redis.CommandFlags.FireAndForget).ConfigureAwait(false);
     }
 
     private async Task<User?> EnsureUserHasVanity(string uid, CancellationToken cancellationToken = default)
     {
         cancellationToken = cancellationToken == default && _contextAccessor.HttpContext != null
-            ? _contextAccessor.HttpContext.RequestAborted
+            ? RequestAbortedToken
             : cancellationToken;
 
         var user = await DbContext.Users.SingleOrDefaultAsync(u => u.UID == uid, cancellationToken).ConfigureAwait(false);
@@ -120,6 +127,47 @@ public partial class LightlessHub
         return user;
     }
 
+    private async Task ClearOwnedBroadcastLock()
+    {
+        var db = _redis.Database;
+        var ownershipKey = _broadcastConfiguration.BuildUserOwnershipKey(UserUID);
+        var ownedCidValue = await db.StringGetAsync(ownershipKey).ConfigureAwait(false);
+        if (ownedCidValue.IsNullOrEmpty)
+            return;
+
+        var ownedCid = ownedCidValue.ToString();
+
+        await db.KeyDeleteAsync(ownershipKey, CommandFlags.FireAndForget).ConfigureAwait(false);
+
+        if (string.IsNullOrEmpty(ownedCid))
+            return;
+
+        var broadcastKey = _broadcastConfiguration.BuildRedisKey(ownedCid);
+        var broadcastValue = await db.StringGetAsync(broadcastKey).ConfigureAwait(false);
+        if (broadcastValue.IsNullOrEmpty)
+            return;
+
+        BroadcastRedisEntry? entry;
+        try
+        {
+            entry = JsonSerializer.Deserialize<BroadcastRedisEntry>(broadcastValue!);
+        }
+        catch (Exception ex)
+        {
+            _logger.LogCallWarning(LightlessHubLogger.Args("failed to deserialize broadcast during disconnect cleanup", "CID", ownedCid, "Value", broadcastValue, "Error", ex));
+            return;
+        }
+
+        if (entry is null)
+            return;
+
+        if (entry.HasOwner() && !entry.OwnedBy(UserUID))
+            return;
+
+        await db.KeyDeleteAsync(broadcastKey, CommandFlags.FireAndForget).ConfigureAwait(false);
+        _logger.LogCallInfo(LightlessHubLogger.Args("broadcast cleaned on disconnect", UserUID, "CID", entry.HashedCID, "GID", entry.GID));
+    }
+
     private async Task SendGroupDeletedToAll(List<GroupPair> groupUsers)
     {
         foreach (var pair in groupUsers)
@@ -188,7 +236,13 @@ public partial class LightlessHub
 
     private async Task UpdateUserOnRedis()
     {
-        await _redis.AddAsync("UID:" + UserUID, UserCharaIdent, TimeSpan.FromSeconds(60), StackExchange.Redis.When.Always, StackExchange.Redis.CommandFlags.FireAndForget).ConfigureAwait(false);
+        var hashedCid = UserCharaIdent;
+        if (IsValidHashedCid(hashedCid))
+        {
+            await _redis.AddAsync("CID:" + hashedCid, UserUID, TimeSpan.FromSeconds(60), StackExchange.Redis.When.Always, StackExchange.Redis.CommandFlags.FireAndForget).ConfigureAwait(false);
+        }
+
+        await _redis.AddAsync("UID:" + UserUID, hashedCid, TimeSpan.FromSeconds(60), StackExchange.Redis.When.Always, StackExchange.Redis.CommandFlags.FireAndForget).ConfigureAwait(false);
     }
 
     private async Task UserGroupLeave(GroupPair groupUserPair, string userIdent, Dictionary<string, UserInfo> allUserPairs, string? uid = null)

LightlessSyncServer/LightlessSyncServer/Hubs/LightlessHub.Groups.cs

@@ -59,7 +59,7 @@ public partial class LightlessHub
         group.PreferDisableAnimations = dto.Permissions.HasFlag(GroupPermissions.PreferDisableAnimations);
         group.PreferDisableVFX = dto.Permissions.HasFlag(GroupPermissions.PreferDisableVFX);
 
-        await DbContext.SaveChangesAsync(_contextAccessor.HttpContext.RequestAborted).ConfigureAwait(false);
+        await DbContext.SaveChangesAsync(RequestAbortedToken).ConfigureAwait(false);
 
         var groupPairs = DbContext.GroupPairs.Where(p => p.GroupGID == dto.Group.GID).Select(p => p.GroupUserUID).ToList();
         await Clients.Users(groupPairs).Client_GroupChangePermissions(new GroupPermissionDto(dto.Group, dto.Permissions)).ConfigureAwait(false);
@@ -137,7 +137,7 @@ public partial class LightlessHub
 
             var allUserPairs = await GetAllPairInfo(pair.GroupUserUID).ConfigureAwait(false);
 
-            var sharedData = await DbContext.CharaDataAllowances.Where(u => u.AllowedGroup != null && u.AllowedGroupGID == dto.GID && u.ParentUploaderUID == pair.GroupUserUID).ToListAsync(cancellationToken: _contextAccessor.HttpContext.RequestAborted).ConfigureAwait(false);
+            var sharedData = await DbContext.CharaDataAllowances.Where(u => u.AllowedGroup != null && u.AllowedGroupGID == dto.GID && u.ParentUploaderUID == pair.GroupUserUID).ToListAsync(cancellationToken: RequestAbortedToken).ConfigureAwait(false);
             DbContext.CharaDataAllowances.RemoveRange(sharedData);
 
             foreach (var groupUserPair in groupPairs.Where(p => !string.Equals(p.GroupUserUID, pair.GroupUserUID, StringComparison.Ordinal)))
@@ -181,7 +181,7 @@ public partial class LightlessHub
 
             var allUserPairs = await GetAllPairInfo(pair.GroupUserUID).ConfigureAwait(false);
 
-            var sharedData = await DbContext.CharaDataAllowances.Where(u => u.AllowedGroup != null && u.AllowedGroupGID == dto.GID && u.ParentUploaderUID == pair.GroupUserUID).ToListAsync(cancellationToken: _contextAccessor.HttpContext.RequestAborted).ConfigureAwait(false);
+            var sharedData = await DbContext.CharaDataAllowances.Where(u => u.AllowedGroup != null && u.AllowedGroupGID == dto.GID && u.ParentUploaderUID == pair.GroupUserUID).ToListAsync(cancellationToken: RequestAbortedToken).ConfigureAwait(false);
 
             DbContext.CharaDataAllowances.RemoveRange(sharedData);
 
@@ -199,15 +199,15 @@ public partial class LightlessHub
     public async Task<GroupJoinDto> GroupCreate()
     {
         _logger.LogCallInfo();
-        var existingGroupsByUser = await DbContext.Groups.CountAsync(u => u.OwnerUID == UserUID, cancellationToken: _contextAccessor.HttpContext.RequestAborted).ConfigureAwait(false);
+        var existingGroupsByUser = await DbContext.Groups.CountAsync(u => u.OwnerUID == UserUID, cancellationToken: RequestAbortedToken).ConfigureAwait(false);
-        var existingJoinedGroups = await DbContext.GroupPairs.CountAsync(u => u.GroupUserUID == UserUID, cancellationToken: _contextAccessor.HttpContext.RequestAborted).ConfigureAwait(false);
+        var existingJoinedGroups = await DbContext.GroupPairs.CountAsync(u => u.GroupUserUID == UserUID, cancellationToken: RequestAbortedToken).ConfigureAwait(false);
         if (existingGroupsByUser >= _maxExistingGroupsByUser || existingJoinedGroups >= _maxJoinedGroupsByUser)
         {
             throw new System.Exception($"Max groups for user is {_maxExistingGroupsByUser}, max joined groups is {_maxJoinedGroupsByUser}.");
         }
 
         var gid = StringUtils.GenerateRandomString(12);
-        while (await DbContext.Groups.AnyAsync(g => g.GID == "LLS-" + gid, cancellationToken: _contextAccessor.HttpContext.RequestAborted).ConfigureAwait(false))
+        while (await DbContext.Groups.AnyAsync(g => g.GID == "LLS-" + gid, cancellationToken: RequestAbortedToken).ConfigureAwait(false))
         {
             gid = StringUtils.GenerateRandomString(12);
         }
@@ -218,7 +218,7 @@ public partial class LightlessHub
         var hashedPw = StringUtils.Sha256String(passwd);
         var currentTime = DateTime.UtcNow;
 
-        UserDefaultPreferredPermission defaultPermissions = await DbContext.UserDefaultPreferredPermissions.SingleAsync(u => u.UserUID == UserUID, cancellationToken: _contextAccessor.HttpContext.RequestAborted).ConfigureAwait(false);
+        UserDefaultPreferredPermission defaultPermissions = await DbContext.UserDefaultPreferredPermissions.SingleAsync(u => u.UserUID == UserUID, cancellationToken: RequestAbortedToken).ConfigureAwait(false);
 
         Group newGroup = new()
         {
@@ -250,12 +250,12 @@ public partial class LightlessHub
             DisableVFX = defaultPermissions.DisableGroupAnimations,
         };
 
-        await DbContext.Groups.AddAsync(newGroup, _contextAccessor.HttpContext.RequestAborted).ConfigureAwait(false);
+        await DbContext.Groups.AddAsync(newGroup, RequestAbortedToken).ConfigureAwait(false);
-        await DbContext.GroupPairs.AddAsync(initialPair, _contextAccessor.HttpContext.RequestAborted).ConfigureAwait(false);
+        await DbContext.GroupPairs.AddAsync(initialPair, RequestAbortedToken).ConfigureAwait(false);
-        await DbContext.GroupPairPreferredPermissions.AddAsync(initialPrefPermissions, _contextAccessor.HttpContext.RequestAborted).ConfigureAwait(false);
+        await DbContext.GroupPairPreferredPermissions.AddAsync(initialPrefPermissions, RequestAbortedToken).ConfigureAwait(false);
-        await DbContext.SaveChangesAsync(_contextAccessor.HttpContext.RequestAborted).ConfigureAwait(false);
+        await DbContext.SaveChangesAsync(RequestAbortedToken).ConfigureAwait(false);
 
-        var self = await DbContext.Users.SingleAsync(u => u.UID == UserUID, cancellationToken: _contextAccessor.HttpContext.RequestAborted).ConfigureAwait(false);
+        var self = await DbContext.Users.SingleAsync(u => u.UID == UserUID, cancellationToken: RequestAbortedToken).ConfigureAwait(false);
 
         await Clients.User(UserUID).Client_GroupSendFullInfo(new GroupFullInfoDto(newGroup.ToGroupData(), self.ToUserData(),
             newGroup.ToEnum(), initialPrefPermissions.ToEnum(), initialPair.ToEnum(), new(StringComparer.Ordinal)))
@@ -314,10 +314,10 @@ public partial class LightlessHub
 
         _logger.LogCallInfo(LightlessHubLogger.Args(dto, "Success"));
 
-        var groupPairs = await DbContext.GroupPairs.Where(p => p.GroupGID == dto.Group.GID).ToListAsync(cancellationToken: _contextAccessor.HttpContext.RequestAborted).ConfigureAwait(false);
+        var groupPairs = await DbContext.GroupPairs.Where(p => p.GroupGID == dto.Group.GID).ToListAsync(cancellationToken: RequestAbortedToken).ConfigureAwait(false);
         DbContext.RemoveRange(groupPairs);
         DbContext.Remove(group);
-        await DbContext.SaveChangesAsync(_contextAccessor.HttpContext.RequestAborted).ConfigureAwait(false);
+        await DbContext.SaveChangesAsync(RequestAbortedToken).ConfigureAwait(false);
 
         await Clients.Users(groupPairs.Select(g => g.GroupUserUID)).Client_GroupDelete(new GroupDto(group.ToGroupData())).ConfigureAwait(false);
 
@@ -332,7 +332,7 @@ public partial class LightlessHub
         var (userHasRights, group) = await TryValidateGroupModeratorOrOwner(dto.GID).ConfigureAwait(false);
         if (!userHasRights) return [];
 
-        var banEntries = await DbContext.GroupBans.Include(b => b.BannedUser).Where(g => g.GroupGID == dto.Group.GID).AsNoTracking().ToListAsync(cancellationToken: _contextAccessor.HttpContext.RequestAborted).ConfigureAwait(false);
+        var banEntries = await DbContext.GroupBans.Include(b => b.BannedUser).Where(g => g.GroupGID == dto.Group.GID).AsNoTracking().ToListAsync(cancellationToken: RequestAbortedToken).ConfigureAwait(false);
 
         List<BannedGroupUserDto> bannedGroupUsers = banEntries.Select(b =>
             new BannedGroupUserDto(group.ToGroupData(), b.BannedUser.ToUserData(), b.BannedReason, b.BannedOn,
@@ -350,14 +350,14 @@ public partial class LightlessHub
 
         _logger.LogCallInfo(LightlessHubLogger.Args(dto));
 
-        var group = await DbContext.Groups.Include(g => g.Owner).AsNoTracking().SingleOrDefaultAsync(g => g.GID == aliasOrGid || g.Alias == aliasOrGid, cancellationToken: _contextAccessor.HttpContext.RequestAborted).ConfigureAwait(false);
+        var group = await DbContext.Groups.Include(g => g.Owner).AsNoTracking().SingleOrDefaultAsync(g => g.GID == aliasOrGid || g.Alias == aliasOrGid, cancellationToken: RequestAbortedToken).ConfigureAwait(false);
         var groupGid = group?.GID ?? string.Empty;
-        var existingPair = await DbContext.GroupPairs.AsNoTracking().SingleOrDefaultAsync(g => g.GroupGID == groupGid && g.GroupUserUID == UserUID, cancellationToken: _contextAccessor.HttpContext.RequestAborted).ConfigureAwait(false);
+        var existingPair = await DbContext.GroupPairs.AsNoTracking().SingleOrDefaultAsync(g => g.GroupGID == groupGid && g.GroupUserUID == UserUID, cancellationToken: RequestAbortedToken).ConfigureAwait(false);
         var hashedPw = StringUtils.Sha256String(dto.Password);
-        var existingUserCount = await DbContext.GroupPairs.AsNoTracking().CountAsync(g => g.GroupGID == groupGid, cancellationToken: _contextAccessor.HttpContext.RequestAborted).ConfigureAwait(false);
+        var existingUserCount = await DbContext.GroupPairs.AsNoTracking().CountAsync(g => g.GroupGID == groupGid, cancellationToken: RequestAbortedToken).ConfigureAwait(false);
-        var joinedGroups = await DbContext.GroupPairs.CountAsync(g => g.GroupUserUID == UserUID, cancellationToken: _contextAccessor.HttpContext.RequestAborted).ConfigureAwait(false);
+        var joinedGroups = await DbContext.GroupPairs.CountAsync(g => g.GroupUserUID == UserUID, cancellationToken: RequestAbortedToken).ConfigureAwait(false);
-        var isBanned = await DbContext.GroupBans.AnyAsync(g => g.GroupGID == groupGid && g.BannedUserUID == UserUID, cancellationToken: _contextAccessor.HttpContext.RequestAborted).ConfigureAwait(false);
+        var isBanned = await DbContext.GroupBans.AnyAsync(g => g.GroupGID == groupGid && g.BannedUserUID == UserUID, cancellationToken: RequestAbortedToken).ConfigureAwait(false);
-        var oneTimeInvite = await DbContext.GroupTempInvites.SingleOrDefaultAsync(g => g.GroupGID == groupGid && g.Invite == hashedPw, cancellationToken: _contextAccessor.HttpContext.RequestAborted).ConfigureAwait(false);
+        var oneTimeInvite = await DbContext.GroupTempInvites.SingleOrDefaultAsync(g => g.GroupGID == groupGid && g.Invite == hashedPw, cancellationToken: RequestAbortedToken).ConfigureAwait(false);
 
         if (group == null
             || (!string.Equals(group.HashedPassword, hashedPw, StringComparison.Ordinal) && oneTimeInvite == null)
@@ -378,7 +378,7 @@ public partial class LightlessHub
 
         _logger.LogCallInfo(LightlessHubLogger.Args(dto));
 
-        var group = await DbContext.Groups.Include(g => g.Owner).AsNoTracking().SingleOrDefaultAsync(g => g.GID == aliasOrGid || g.Alias == aliasOrGid, cancellationToken: _contextAccessor.HttpContext.RequestAborted).ConfigureAwait(false);
+        var group = await DbContext.Groups.Include(g => g.Owner).AsNoTracking().SingleOrDefaultAsync(g => g.GID == aliasOrGid || g.Alias == aliasOrGid, cancellationToken: RequestAbortedToken).ConfigureAwait(false);
         var groupGid = group?.GID ?? string.Empty;
         var existingPair = await DbContext.GroupPairs.AsNoTracking().SingleOrDefaultAsync(g => g.GroupGID == groupGid && g.GroupUserUID == UserUID).ConfigureAwait(false);
         var isHashedPassword = dto.Password.Length == 64 && dto.Password.All(Uri.IsHexDigit);
@@ -416,7 +416,7 @@ public partial class LightlessHub
             FromFinder = isHashedPassword
         };
 
-        var preferredPermissions = await DbContext.GroupPairPreferredPermissions.SingleOrDefaultAsync(u => u.UserUID == UserUID && u.GroupGID == group.GID, cancellationToken: _contextAccessor.HttpContext.RequestAborted).ConfigureAwait(false);
+        var preferredPermissions = await DbContext.GroupPairPreferredPermissions.SingleOrDefaultAsync(u => u.UserUID == UserUID && u.GroupGID == group.GID, cancellationToken: RequestAbortedToken).ConfigureAwait(false);
         if (preferredPermissions == null)
         {
             GroupPairPreferredPermission newPerms = new()
@@ -441,13 +441,13 @@ public partial class LightlessHub
             DbContext.Update(preferredPermissions);
         }
 
-        await DbContext.GroupPairs.AddAsync(newPair, _contextAccessor.HttpContext.RequestAborted).ConfigureAwait(false);
+        await DbContext.GroupPairs.AddAsync(newPair, RequestAbortedToken).ConfigureAwait(false);
 
         _logger.LogCallInfo(LightlessHubLogger.Args(aliasOrGid, "Success"));
 
-        await DbContext.SaveChangesAsync(_contextAccessor.HttpContext.RequestAborted).ConfigureAwait(false);
+        await DbContext.SaveChangesAsync(RequestAbortedToken).ConfigureAwait(false);
 
-        var groupInfos = await DbContext.GroupPairs.Where(u => u.GroupGID == group.GID && (u.IsPinned || u.IsModerator)).ToListAsync(cancellationToken: _contextAccessor.HttpContext.RequestAborted).ConfigureAwait(false);
+        var groupInfos = await DbContext.GroupPairs.Where(u => u.GroupGID == group.GID && (u.IsPinned || u.IsModerator)).ToListAsync(cancellationToken: RequestAbortedToken).ConfigureAwait(false);
         await Clients.User(UserUID).Client_GroupSendFullInfo(new GroupFullInfoDto(group.ToGroupData(), group.Owner.ToUserData(),
             group.ToEnum(), preferredPermissions.ToEnum(), newPair.ToEnum(),
             groupInfos.ToDictionary(u => u.GroupUserUID, u => u.ToEnum(), StringComparer.Ordinal))).ConfigureAwait(false);
@@ -575,7 +575,7 @@ public partial class LightlessHub
             }
         }
 
-        await DbContext.SaveChangesAsync(_contextAccessor.HttpContext.RequestAborted).ConfigureAwait(false);
+        await DbContext.SaveChangesAsync(RequestAbortedToken).ConfigureAwait(false);
 
         return true;
     }
@@ -693,7 +693,7 @@ public partial class LightlessHub
                 .Client_GroupPairLeft(new GroupPairDto(dto.Group, pair.GroupUser.ToUserData())).ConfigureAwait(false);
         }
 
-        await DbContext.SaveChangesAsync(_contextAccessor.HttpContext.RequestAborted).ConfigureAwait(false);
+        await DbContext.SaveChangesAsync(RequestAbortedToken).ConfigureAwait(false);
 
         return usersToPrune.Count();
     }
@@ -717,15 +717,15 @@ public partial class LightlessHub
         var groupPairs = DbContext.GroupPairs.Where(p => p.GroupGID == group.GID).AsNoTracking().ToList();
         await Clients.Users(groupPairs.Select(p => p.GroupUserUID)).Client_GroupPairLeft(dto).ConfigureAwait(false);
 
-        var sharedData = await DbContext.CharaDataAllowances.Where(u => u.AllowedGroup != null && u.AllowedGroupGID == dto.GID && u.ParentUploaderUID == dto.UID).ToListAsync(cancellationToken: _contextAccessor.HttpContext.RequestAborted).ConfigureAwait(false);
+        var sharedData = await DbContext.CharaDataAllowances.Where(u => u.AllowedGroup != null && u.AllowedGroupGID == dto.GID && u.ParentUploaderUID == dto.UID).ToListAsync(cancellationToken: RequestAbortedToken).ConfigureAwait(false);
         DbContext.CharaDataAllowances.RemoveRange(sharedData);
 
-        await DbContext.SaveChangesAsync(_contextAccessor.HttpContext.RequestAborted).ConfigureAwait(false);
+        await DbContext.SaveChangesAsync(RequestAbortedToken).ConfigureAwait(false);
 
         var userIdent = await GetUserIdent(dto.User.UID).ConfigureAwait(false);
         if (userIdent == null)
         {
-            await DbContext.SaveChangesAsync(_contextAccessor.HttpContext.RequestAborted).ConfigureAwait(false);
+            await DbContext.SaveChangesAsync(RequestAbortedToken).ConfigureAwait(false);
             return;
         }
 
@@ -743,10 +743,10 @@ public partial class LightlessHub
     {
         _logger.LogCallInfo(LightlessHubLogger.Args(dto));
 
-        var cancellationToken = _contextAccessor.HttpContext.RequestAborted;
+        var cancellationToken = RequestAbortedToken;
 
         var data = await DbContext.GroupProfiles
-            .FirstOrDefaultAsync(g => g.GroupGID == dto.Group.GID, cancellationToken)
+            .FirstOrDefaultAsync(g => g.GroupGID == dto.Group.GID)
             .ConfigureAwait(false);
 
         var profileDto = new GroupProfileDto(dto.Group, Description: null, Tags: null, PictureBase64: null);
@@ -780,7 +780,7 @@ public partial class LightlessHub
 
         var groupProfileDb = await DbContext.GroupProfiles
             .FirstOrDefaultAsync(g => g.GroupGID == dto.Group.GID,
-                                 _contextAccessor.HttpContext.RequestAborted)
+                                 RequestAbortedToken)
             .ConfigureAwait(false);
 
         if (groupProfileDb != null)
@@ -800,11 +800,11 @@ public partial class LightlessHub
             };
 
             await DbContext.GroupProfiles.AddAsync(groupProfile,
-                _contextAccessor.HttpContext.RequestAborted)
+                RequestAbortedToken)
                 .ConfigureAwait(false);
         }
 
-        await DbContext.SaveChangesAsync(_contextAccessor.HttpContext.RequestAborted).ConfigureAwait(false);
+        await DbContext.SaveChangesAsync(RequestAbortedToken).ConfigureAwait(false);
     }
 
     [Authorize(Policy = "Identified")]
@@ -836,9 +836,9 @@ public partial class LightlessHub
             userPair.IsModerator = false;
         }
 
-        await DbContext.SaveChangesAsync(_contextAccessor.HttpContext.RequestAborted).ConfigureAwait(false);
+        await DbContext.SaveChangesAsync(RequestAbortedToken).ConfigureAwait(false);
 
-        var groupPairs = await DbContext.GroupPairs.AsNoTracking().Where(p => p.GroupGID == dto.Group.GID).Select(p => p.GroupUserUID).ToListAsync(cancellationToken: _contextAccessor.HttpContext.RequestAborted).ConfigureAwait(false);
+        var groupPairs = await DbContext.GroupPairs.AsNoTracking().Where(p => p.GroupGID == dto.Group.GID).Select(p => p.GroupUserUID).ToListAsync(cancellationToken: RequestAbortedToken).ConfigureAwait(false);
         await Clients.Users(groupPairs).Client_GroupPairChangeUserInfo(new GroupPairUserInfoDto(dto.Group, dto.User, userPair.ToEnum())).ConfigureAwait(false);
     }
 
@@ -847,7 +847,7 @@ public partial class LightlessHub
     {
         _logger.LogCallInfo();
 
-        var ct = _contextAccessor.HttpContext.RequestAborted;
+        var ct = RequestAbortedToken;
 
         var result = await (
             from gp in DbContext.GroupPairs
@@ -866,7 +866,7 @@ public partial class LightlessHub
                     .ToList(),
             })
             .AsNoTracking()
-            .ToListAsync(ct)
+            .ToListAsync()
             .ConfigureAwait(false);
 
         _logger.LogCallInfo(LightlessHubLogger.Args(result));
@@ -899,11 +899,11 @@ public partial class LightlessHub
         var (userHasRights, _) = await TryValidateGroupModeratorOrOwner(dto.Group.GID).ConfigureAwait(false);
         if (!userHasRights) return;
 
-        var banEntry = await DbContext.GroupBans.SingleOrDefaultAsync(g => g.GroupGID == dto.Group.GID && g.BannedUserUID == dto.User.UID, cancellationToken: _contextAccessor.HttpContext.RequestAborted).ConfigureAwait(false);
+        var banEntry = await DbContext.GroupBans.SingleOrDefaultAsync(g => g.GroupGID == dto.Group.GID && g.BannedUserUID == dto.User.UID, cancellationToken: RequestAbortedToken).ConfigureAwait(false);
         if (banEntry == null) return;
 
         DbContext.Remove(banEntry);
-        await DbContext.SaveChangesAsync(_contextAccessor.HttpContext.RequestAborted).ConfigureAwait(false);
+        await DbContext.SaveChangesAsync(RequestAbortedToken).ConfigureAwait(false);
 
         _logger.LogCallInfo(LightlessHubLogger.Args(dto, "Success"));
     }

LightlessSyncServer/LightlessSyncServer/Hubs/LightlessHub.User.cs

@@ -1,10 +1,9 @@
-using LightlessSync.API.Data;
+using LightlessSync.API.Data;
 using LightlessSync.API.Data.Enum;
 using LightlessSync.API.Data.Extensions;
 using LightlessSync.API.Dto.Group;
 using LightlessSync.API.Dto.User;
 using LightlessSyncServer.Utils;
-using LightlessSyncServer.Configuration;
 using LightlessSyncShared.Metrics;
 using LightlessSyncShared.Models;
 using LightlessSyncShared.Utils;
@@ -14,7 +13,6 @@ using Microsoft.EntityFrameworkCore;
 using SixLabors.ImageSharp;
 using SixLabors.ImageSharp.PixelFormats;
 using StackExchange.Redis;
-using System.Linq;
 using System.Text;
 using System.Text.Json;
 using System.Text.RegularExpressions;
@@ -35,7 +33,7 @@ public partial class LightlessHub
         if (string.Equals(dto.User.UID, UserUID, StringComparison.Ordinal) || string.IsNullOrWhiteSpace(dto.User.UID)) return;
 
         // grab other user, check if it exists and if a pair already exists
-        var otherUser = await DbContext.Users.SingleOrDefaultAsync(u => u.UID == uid || u.Alias == uid, cancellationToken: _contextAccessor.HttpContext.RequestAborted).ConfigureAwait(false);
+        var otherUser = await DbContext.Users.SingleOrDefaultAsync(u => u.UID == uid || u.Alias == uid, cancellationToken: RequestAbortedToken).ConfigureAwait(false);
         if (otherUser == null)
         {
             await Clients.Caller.Client_ReceiveServerMessage(MessageSeverity.Warning, $"Cannot pair with {dto.User.UID}, UID does not exist").ConfigureAwait(false);
@@ -51,7 +49,7 @@ public partial class LightlessHub
         var existingEntry =
             await DbContext.ClientPairs.AsNoTracking()
                 .FirstOrDefaultAsync(p =>
-                    p.User.UID == UserUID && p.OtherUserUID == otherUser.UID, cancellationToken: _contextAccessor.HttpContext.RequestAborted).ConfigureAwait(false);
+                    p.User.UID == UserUID && p.OtherUserUID == otherUser.UID, cancellationToken: RequestAbortedToken).ConfigureAwait(false);
 
         if (existingEntry != null)
         {
@@ -76,7 +74,7 @@ public partial class LightlessHub
         var permissions = existingData?.OwnPermissions;
         if (permissions == null || !permissions.Sticky) 
         {
-            var ownDefaultPermissions = await DbContext.UserDefaultPreferredPermissions.AsNoTracking().SingleOrDefaultAsync(f => f.UserUID == UserUID, cancellationToken: _contextAccessor.HttpContext.RequestAborted).ConfigureAwait(false);
+            var ownDefaultPermissions = await DbContext.UserDefaultPreferredPermissions.AsNoTracking().SingleOrDefaultAsync(f => f.UserUID == UserUID, cancellationToken: RequestAbortedToken).ConfigureAwait(false);
 
             permissions = new UserPermissionSet()
             {
@@ -89,7 +87,7 @@ public partial class LightlessHub
                 Sticky = true
             };
 
-            var existingDbPerms = await DbContext.Permissions.SingleOrDefaultAsync(u => u.UserUID == UserUID && u.OtherUserUID == otherUser.UID, cancellationToken: _contextAccessor.HttpContext.RequestAborted).ConfigureAwait(false);
+            var existingDbPerms = await DbContext.Permissions.SingleOrDefaultAsync(u => u.UserUID == UserUID && u.OtherUserUID == otherUser.UID, cancellationToken: RequestAbortedToken).ConfigureAwait(false);
             if (existingDbPerms == null)
             {
                 await DbContext.Permissions.AddAsync(permissions).ConfigureAwait(false);
@@ -143,17 +141,15 @@ public partial class LightlessHub
     }
 
     [Authorize(Policy = "Identified")]
-    public async Task TryPairWithContentId(string otherCid, string myCid)
+    public async Task TryPairWithContentId(string otherCid)
     {
+        var myCid = UserCharaIdent;
+
         if (string.IsNullOrWhiteSpace(otherCid) || string.IsNullOrWhiteSpace(myCid))
             return;
 
-        bool IsValidCid(string cid) => cid.Length == 64 && cid.All(Uri.IsHexDigit) && !cid.All(c => c == '0');
+        if (!IsValidHashedCid(myCid) || !IsValidHashedCid(otherCid))
-
-        if (!IsValidCid(myCid) || !IsValidCid(otherCid))
-        {
             return;
-        }
 
         if (string.Equals(otherCid, myCid, StringComparison.Ordinal))
         {
@@ -181,12 +177,33 @@ public partial class LightlessHub
             try
             {
                 var payload = JsonSerializer.Deserialize<PairingPayload>(json);
-                if (payload?.UID == null)
+                if (payload?.UID == null || string.IsNullOrWhiteSpace(payload.HashedCid))
                 {
                     _logger.LogCallWarning(LightlessHubLogger.Args("invalid payload", reverseKey));
                     return;
                 }
 
+                if (!IsValidHashedCid(payload.HashedCid) || !string.Equals(payload.HashedCid, otherCid, StringComparison.Ordinal))
+                {
+                    _logger.LogCallWarning(LightlessHubLogger.Args("pairing cid mismatch", reverseKey, payload.HashedCid, otherCid));
+                    return;
+                }
+
+                var expectedRequesterUid = await _redis.GetAsync<string>("CID:" + payload.HashedCid).ConfigureAwait(false);
+                if (!string.Equals(expectedRequesterUid, payload.UID, StringComparison.Ordinal))
+                {
+                    _logger.LogCallWarning(LightlessHubLogger.Args("pairing uid mismatch", reverseKey, payload.HashedCid, payload.UID, expectedRequesterUid ?? "null"));
+                    await Clients.Caller.Client_ReceiveServerMessage(MessageSeverity.Warning, "Pair request could not be validated.").ConfigureAwait(false);
+                    return;
+                }
+
+                if (payload.Timestamp == default || DateTime.UtcNow - payload.Timestamp > TimeSpan.FromMinutes(5))
+                {
+                    _logger.LogCallWarning(LightlessHubLogger.Args("stale pairing payload", reverseKey, payload.Timestamp));
+                    await Clients.Caller.Client_ReceiveServerMessage(MessageSeverity.Warning, "Pair request expired.").ConfigureAwait(false);
+                    return;
+                }
+
                 var sender = await _pairService.TryAddPairAsync(UserUID, payload.UID);
                 var receiver = await _pairService.TryAddPairAsync(payload.UID, UserUID);
 
@@ -251,9 +268,30 @@ public partial class LightlessHub
         }
         else
         {
+            int maxRequests = _broadcastConfiguration.PairRequestRateLimit;
+            int requestWindow = _broadcastConfiguration.PairRequestRateWindow;
+            TimeSpan window = TimeSpan.FromSeconds(requestWindow);
+            var rateKey = $"pairing:limit:{UserUID}";
+            var db = _redis.Database;
+
+            var count = (long)await db.StringIncrementAsync(rateKey).ConfigureAwait(false);
+            if (count == 1)
+            {
+                await db.KeyExpireAsync(rateKey, window).ConfigureAwait(false);
+            }
+
+            if (count > maxRequests)
+            {
+                var ttl = await db.KeyTimeToLiveAsync(rateKey).ConfigureAwait(false);
+                var secondsLeft = ttl?.TotalSeconds > 0 ? (int)ttl.Value.TotalSeconds : requestWindow;
+                await Clients.Caller.Client_ReceiveServerMessage(MessageSeverity.Warning, $"You have exceeded the pair request limit. Please wait {secondsLeft} seconds before trying again.").ConfigureAwait(false);
+                return;
+            }
+
             var payload = new PairingPayload
             {
                 UID = UserUID,
+                HashedCid = myCid,
                 Timestamp = DateTime.UtcNow
             };
 
@@ -262,14 +300,16 @@ public partial class LightlessHub
             await Clients.Caller.Client_ReceiveServerMessage(MessageSeverity.Information, $"Pair request sent. Waiting for the other player to confirm.").ConfigureAwait(false);
 
             _logger.LogCallInfo(LightlessHubLogger.Args("stored pairing request", myCid, otherCid));
-            await NotifyBroadcastOwnerOfPairRequest(myCid, otherCid).ConfigureAwait(false);
+            await NotifyBroadcastOwnerOfPairRequest(otherCid).ConfigureAwait(false);
         }
     }
 
 
-    private async Task NotifyBroadcastOwnerOfPairRequest(string myHashedCid, string targetHashedCid)
+    private async Task NotifyBroadcastOwnerOfPairRequest(string targetHashedCid)
     {
-        if (string.IsNullOrWhiteSpace(targetHashedCid) || string.IsNullOrWhiteSpace(myHashedCid))
+        var myHashedCid = UserCharaIdent;
+
+        if (!IsValidHashedCid(targetHashedCid) || !IsValidHashedCid(myHashedCid))
             return;
 
         if (!_broadcastConfiguration.EnableBroadcasting || !_broadcastConfiguration.NotifyOwnerOnPairRequest)
@@ -323,6 +363,7 @@ public partial class LightlessHub
     private class PairingPayload
     {
         public string UID { get; set; } = string.Empty;
+        public string HashedCid { get; set; } = string.Empty;
         public DateTime Timestamp { get; set; }
     }
 
@@ -338,8 +379,10 @@ public partial class LightlessHub
     }
 
     [Authorize(Policy = "Identified")]
-    public async Task SetBroadcastStatus(string hashedCid, bool enabled, GroupBroadcastRequestDto? groupDto = null)
+    public async Task SetBroadcastStatus(bool enabled, GroupBroadcastRequestDto? groupDto = null)
     {
+        var hashedCid = UserCharaIdent;
+
         if (enabled && !_broadcastConfiguration.EnableBroadcasting)
         {
             _logger.LogCallWarning(LightlessHubLogger.Args("broadcast disabled", UserUID, "CID", hashedCid));
@@ -347,9 +390,9 @@ public partial class LightlessHub
             return;
         }
 
-        if (string.IsNullOrWhiteSpace(hashedCid) || hashedCid.Length != 64 || !hashedCid.All(c => Uri.IsHexDigit(c)))
+        if (!IsValidHashedCid(hashedCid))
         {
-            _logger.LogCallWarning(LightlessHubLogger.Args("invalid cid format", UserUID, "CID", hashedCid));
+            _logger.LogCallWarning(LightlessHubLogger.Args("invalid cid format for user ident", UserUID, "CID", hashedCid));
             await Clients.Caller.Client_ReceiveServerMessage(MessageSeverity.Error, "Invalid CID format.").ConfigureAwait(false);
             return;
         }
@@ -361,11 +404,32 @@ public partial class LightlessHub
 
         var db = _redis.Database;
         var broadcastKey = _broadcastConfiguration.BuildRedisKey(hashedCid);
+        var ownershipKey = _broadcastConfiguration.BuildUserOwnershipKey(UserUID);
+        var ownedCidValue = await db.StringGetAsync(ownershipKey).ConfigureAwait(false);
+        var ownedCid = ownedCidValue.IsNullOrEmpty ? null : ownedCidValue.ToString();
 
         if (enabled)
         {
             string? gid = null;
 
+            if (!string.IsNullOrEmpty(ownedCid) && !string.Equals(ownedCid, hashedCid, StringComparison.Ordinal))
+            {
+                var ownedBroadcastKey = _broadcastConfiguration.BuildRedisKey(ownedCid);
+                var ownedBroadcastValue = await db.StringGetAsync(ownedBroadcastKey).ConfigureAwait(false);
+
+                if (ownedBroadcastValue.IsNullOrEmpty)
+                {
+                    await db.KeyDeleteAsync(ownershipKey, CommandFlags.FireAndForget).ConfigureAwait(false);
+                    ownedCid = null;
+                }
+                else
+                {
+                    _logger.LogCallWarning(LightlessHubLogger.Args("multiple broadcast lock attempt", UserUID, "ExistingCID", ownedCid, "AttemptedCID", hashedCid));
+                    await Clients.Caller.Client_ReceiveServerMessage(MessageSeverity.Error, "You already have an active Lightfinder lock. Disable it before enabling another.").ConfigureAwait(false);
+                    return;
+                }
+            }
+
             if (groupDto is not null)
             {
                 if (!_broadcastConfiguration.EnableSyncshellBroadcastPayloads)
@@ -400,7 +464,7 @@ public partial class LightlessHub
                 if (existingEntry is not null && existingEntry.HasOwner() && !existingEntry.OwnedBy(UserUID))
                 {
                     _logger.LogCallWarning(LightlessHubLogger.Args("unauthorized attempt to take broadcast ownership", UserUID, "CID", hashedCid, "ExistingOwner", existingEntry.OwnerUID));
-                    await Clients.Caller.Client_ReceiveServerMessage(MessageSeverity.Error, "Another user is already broadcasting with that CID.");
+                    await Clients.Caller.Client_ReceiveServerMessage(MessageSeverity.Error, "Another user is already broadcasting with that CID.").ConfigureAwait(false);
                     return;
                 }
             }
@@ -414,6 +478,7 @@ public partial class LightlessHub
 
             var json = JsonSerializer.Serialize(entry);
             await db.StringSetAsync(broadcastKey, json, _broadcastConfiguration.BroadcastEntryTtl).ConfigureAwait(false);
+            await db.StringSetAsync(ownershipKey, hashedCid, _broadcastConfiguration.BroadcastEntryTtl).ConfigureAwait(false);
             _logger.LogCallInfo(LightlessHubLogger.Args("broadcast enabled", hashedCid, "GID", gid));
         }
         else
@@ -436,22 +501,35 @@ public partial class LightlessHub
             if (entry is null || !string.Equals(entry.HashedCID, hashedCid, StringComparison.Ordinal))
             {
                 _logger.LogCallWarning(LightlessHubLogger.Args("unauthorized attempt to remove broadcast", UserUID, "CID", hashedCid, "Stored", entry?.HashedCID));
-                await Clients.Caller.Client_ReceiveServerMessage(MessageSeverity.Error, "You can only disable your own broadcast. :3");
+                await Clients.Caller.Client_ReceiveServerMessage(MessageSeverity.Error, "You can only disable your own broadcast. :3").ConfigureAwait(false);
                 return;
             }
 
             if (entry.HasOwner() && !entry.OwnedBy(UserUID))
             {
                 _logger.LogCallWarning(LightlessHubLogger.Args("unauthorized attempt to remove broadcast", UserUID, "CID", hashedCid, "Owner", entry.OwnerUID));
-                await Clients.Caller.Client_ReceiveServerMessage(MessageSeverity.Error, "You can only disable your own broadcast. :3");
+                await Clients.Caller.Client_ReceiveServerMessage(MessageSeverity.Error, "You can only disable your own broadcast. :3").ConfigureAwait(false);
                 return;
             }
 
             await db.KeyDeleteAsync(broadcastKey).ConfigureAwait(false);
+
+            if (!string.IsNullOrEmpty(ownedCid) && string.Equals(ownedCid, hashedCid, StringComparison.Ordinal))
+            {
+                await db.KeyDeleteAsync(ownershipKey).ConfigureAwait(false);
+            }
+
             _logger.LogCallInfo(LightlessHubLogger.Args("broadcast disabled", hashedCid, "GID", entry.GID));
         }
     }
 
+    private static bool IsValidHashedCid(string? cid)
+    {
+        if (string.IsNullOrWhiteSpace(cid))
+            return false;
+
+        return cid.Length == 64 && cid.All(Uri.IsHexDigit) && !cid.All(c => c == '0');
+    }
 
     [Authorize(Policy = "Identified")]
     public async Task<BroadcastStatusInfoDto?> IsUserBroadcasting(string hashedCid)
@@ -459,18 +537,13 @@ public partial class LightlessHub
         if (!_broadcastConfiguration.EnableBroadcasting)
             return null;
 
-        if (string.IsNullOrWhiteSpace(hashedCid) || hashedCid.Length != 64 || !hashedCid.All(c => Uri.IsHexDigit(c)))
+        if (!IsValidHashedCid(hashedCid))
         {
             _logger.LogCallWarning(LightlessHubLogger.Args("invalid cid format", UserUID, "CID", hashedCid));
             await Clients.Caller.Client_ReceiveServerMessage(MessageSeverity.Error, "Invalid CID format.").ConfigureAwait(false);
             return null;
         }
 
-        if (hashedCid.All(c => c == '0'))
-        {
-            return null;
-        }
-
         var db = _redis.Database;
         var key = _broadcastConfiguration.BuildRedisKey(hashedCid);
 
@@ -507,14 +580,16 @@ public partial class LightlessHub
     }
 
     [Authorize(Policy = "Identified")]
-    public async Task<TimeSpan?> GetBroadcastTtl(string hashedCid)
+    public async Task<TimeSpan?> GetBroadcastTtl()
     {
         if (!_broadcastConfiguration.EnableBroadcasting)
             return null;
 
-        if (string.IsNullOrWhiteSpace(hashedCid) || hashedCid.Length != 64 || !hashedCid.All(c => Uri.IsHexDigit(c)))
+        var hashedCid = UserCharaIdent;
+
+        if (!IsValidHashedCid(hashedCid))
         {
-            _logger.LogCallWarning(LightlessHubLogger.Args("invalid cid format", UserUID, "CID", hashedCid));
+            _logger.LogCallWarning(LightlessHubLogger.Args("invalid cid format for user ident", UserUID, "CID", hashedCid));
             await Clients.Caller.Client_ReceiveServerMessage(MessageSeverity.Error, "Invalid CID format.").ConfigureAwait(false);
             return null;
         }
@@ -587,9 +662,7 @@ public partial class LightlessHub
         var tasks = new Dictionary<string, Task<RedisValueWithExpiry>>(hashedCids.Count);
         foreach (var cid in hashedCids)
         {
-            bool validHash = !string.IsNullOrWhiteSpace(cid) && cid.Length == 64 && cid.All(Uri.IsHexDigit) && !cid.All(c => c == '0');
+            if (!IsValidHashedCid(cid))
-
-            if (!validHash)
             {
                 tasks[cid] = Task.FromResult(new RedisValueWithExpiry(RedisValue.Null, null));
                 continue;
@@ -657,7 +730,7 @@ public partial class LightlessHub
     {
         _logger.LogCallInfo();
 
-        var userEntry = await DbContext.Users.SingleAsync(u => u.UID == UserUID, cancellationToken: _contextAccessor.HttpContext.RequestAborted).ConfigureAwait(false);
+        var userEntry = await DbContext.Users.SingleAsync(u => u.UID == UserUID, cancellationToken: RequestAbortedToken).ConfigureAwait(false);
         var secondaryUsers = await DbContext.Auth.Include(u => u.User).Where(u => u.PrimaryUserUID == UserUID).Select(c => c.User).ToListAsync().ConfigureAwait(false);
         foreach (var user in secondaryUsers)
         {
@@ -710,7 +783,7 @@ public partial class LightlessHub
             return new UserProfileDto(user.User, false, null, null, "Due to the pause status you cannot access this users profile.");
         }
 
-        var data = await DbContext.UserProfileData.SingleOrDefaultAsync(u => u.UserUID == user.User.UID, cancellationToken: _contextAccessor.HttpContext.RequestAborted).ConfigureAwait(false);
+        var data = await DbContext.UserProfileData.SingleOrDefaultAsync(u => u.UserUID == user.User.UID, cancellationToken: RequestAbortedToken).ConfigureAwait(false);
         if (data == null) return new UserProfileDto(user.User, false, null, null, null);
 
         if (data.FlaggedForReport) return new UserProfileDto(user.User, true, null, null, "This profile is flagged for report and pending evaluation");
@@ -867,7 +940,7 @@ public partial class LightlessHub
 
         // check if client pair even exists
         ClientPair callerPair =
-            await DbContext.ClientPairs.SingleOrDefaultAsync(w => w.UserUID == UserUID && w.OtherUserUID == dto.User.UID, cancellationToken: _contextAccessor.HttpContext.RequestAborted).ConfigureAwait(false);
+            await DbContext.ClientPairs.SingleOrDefaultAsync(w => w.UserUID == UserUID && w.OtherUserUID == dto.User.UID, cancellationToken: RequestAbortedToken).ConfigureAwait(false);
         if (callerPair == null) return;
 
         var pairData = await GetPairInfo(UserUID, dto.User.UID).ConfigureAwait(false);
@@ -918,7 +991,7 @@ public partial class LightlessHub
 
         if (!string.Equals(dto.User.UID, UserUID, StringComparison.Ordinal)) throw new HubException("Cannot modify profile data for anyone but yourself");
 
-        var existingData = await DbContext.UserProfileData.SingleOrDefaultAsync(u => u.UserUID == dto.User.UID, cancellationToken: _contextAccessor.HttpContext.RequestAborted).ConfigureAwait(false);
+        var existingData = await DbContext.UserProfileData.SingleOrDefaultAsync(u => u.UserUID == dto.User.UID, cancellationToken: RequestAbortedToken).ConfigureAwait(false);
 
         if (existingData?.FlaggedForReport ?? false)
         {

LightlessSyncServer/LightlessSyncServer/Hubs/LightlessHub.cs

@@ -16,6 +16,7 @@ using Microsoft.AspNetCore.SignalR;
 using Microsoft.EntityFrameworkCore;
 using StackExchange.Redis.Extensions.Core.Abstractions;
 using System.Collections.Concurrent;
+using System.Threading;
 
 namespace LightlessSyncServer.Hubs;
 
@@ -44,6 +45,8 @@ public partial class LightlessHub : Hub<ILightlessHub>, ILightlessHub
     private readonly int _maxCharaDataByUser;
     private readonly int _maxCharaDataByUserVanity;
 
+    private CancellationToken RequestAbortedToken => _contextAccessor.HttpContext?.RequestAborted ?? Context?.ConnectionAborted ?? CancellationToken.None;
+
     public LightlessHub(LightlessMetrics lightlessMetrics,
         IDbContextFactory<LightlessDbContext> lightlessDbContextFactory, ILogger<LightlessHub> logger, SystemInfoService systemInfoService,
         IConfigurationService<ServerConfiguration> configuration, IHttpContextAccessor contextAccessor,
@@ -194,6 +197,8 @@ public partial class LightlessHub : Hub<ILightlessHub>, ILightlessHub
                 if (exception != null)
                     _logger.LogCallWarning(LightlessHubLogger.Args(_contextAccessor.GetIpAddress(), Context.ConnectionId, exception.Message, exception.StackTrace));
 
+                await ClearOwnedBroadcastLock().ConfigureAwait(false);
+
                 await RemoveUserFromRedis().ConfigureAwait(false);
 
                 _lightlessCensus.ClearStatistics(UserUID);

LightlessSyncServer/LightlessSyncServer/Services/SystemInfoService.cs

@@ -7,7 +7,9 @@ using LightlessSyncShared.Services;
 using LightlessSyncShared.Utils.Configuration;
 using Microsoft.AspNetCore.SignalR;
 using Microsoft.EntityFrameworkCore;
+using StackExchange.Redis;
 using StackExchange.Redis.Extensions.Core.Abstractions;
+using static LightlessSyncServer.Hubs.LightlessHub;
 
 namespace LightlessSyncServer.Services;
 
@@ -52,6 +54,13 @@ public sealed class SystemInfoService : BackgroundService
                 _lightlessMetrics.SetGaugeTo(MetricsAPI.GaugeAvailableIOWorkerThreads, ioThreads);
 
                 var onlineUsers = (_redis.SearchKeysAsync("UID:*").GetAwaiter().GetResult()).Count();
+
+                var allLightfinderKeys = _redis.SearchKeysAsync("broadcast:*").GetAwaiter().GetResult().Where(c => !c.Contains("owner", StringComparison.Ordinal)).ToHashSet(StringComparer.Ordinal);
+                var allLightfinderItems = _redis.GetAllAsync<BroadcastRedisEntry>(allLightfinderKeys).GetAwaiter().GetResult();
+
+                var countLightFinderUsers = allLightfinderItems.Count;
+                var countLightFinderSyncshells = allLightfinderItems.Count(static l => !string.IsNullOrEmpty(l.Value.GID));
+
                 SystemInfoDto = new SystemInfoDto()
                 {
                     OnlineUsers = onlineUsers,
@@ -66,10 +75,12 @@ public sealed class SystemInfoService : BackgroundService
                     using var db = await _dbContextFactory.CreateDbContextAsync(ct).ConfigureAwait(false);
 
                     _lightlessMetrics.SetGaugeTo(MetricsAPI.GaugeAuthorizedConnections, onlineUsers);
+                    _lightlessMetrics.SetGaugeTo(MetricsAPI.GaugeLightFinderConnections, countLightFinderUsers);
                     _lightlessMetrics.SetGaugeTo(MetricsAPI.GaugePairs, db.ClientPairs.AsNoTracking().Count());
-                    _lightlessMetrics.SetGaugeTo(MetricsAPI.GaugePairsPaused, db.Permissions.AsNoTracking().Where(p => p.IsPaused).Count());
+                    _lightlessMetrics.SetGaugeTo(MetricsAPI.GaugePairsPaused, db.Permissions.AsNoTracking().Count(p => p.IsPaused));
                     _lightlessMetrics.SetGaugeTo(MetricsAPI.GaugeGroups, db.Groups.AsNoTracking().Count());
                     _lightlessMetrics.SetGaugeTo(MetricsAPI.GaugeGroupPairs, db.GroupPairs.AsNoTracking().Count());
+                    _lightlessMetrics.SetGaugeTo(MetricsAPI.GaugeLightFinderGroups, countLightFinderSyncshells);
                     _lightlessMetrics.SetGaugeTo(MetricsAPI.GaugeUsersRegistered, db.Users.AsNoTracking().Count());
                 }
 

LightlessSyncServer/LightlessSyncServer/Startup.cs

@@ -295,6 +295,8 @@ public class Startup
         }, new List<string>
         {
             MetricsAPI.GaugeAuthorizedConnections,
+            MetricsAPI.GaugeLightFinderConnections,
+            MetricsAPI.GaugeLightFinderGroups,
             MetricsAPI.GaugeConnections,
             MetricsAPI.GaugePairs,
             MetricsAPI.GaugePairsPaused,

LightlessSyncServer/LightlessSyncServer/appsettings.json

@@ -36,7 +36,9 @@
     "NotifyOwnerOnPairRequest": true,
     "EnableBroadcasting": true,
     "EnableSyncshellBroadcastPayloads": true,
-    "PairRequestNotificationTemplate": "{DisplayName} sent you a pair request. To accept, right-click them, open the context menu, and send a request back."
+    "PairRequestNotificationTemplate": "{DisplayName} sent you a pair request. To accept, right-click them, open the context menu, and send a request back.",
+    "PairRequestRateLimit": 5,
+    "PairRequestRateWindow": 60
   },
   "AllowedHosts": "*",
   "Kestrel": {

LightlessSyncServer/LightlessSyncShared/Metrics/MetricsAPI.cs

@@ -9,6 +9,8 @@ public class MetricsAPI
     public const string GaugeAvailableIOWorkerThreads = "lightless_available_threadpool_io";
     public const string GaugeUsersRegistered = "lightless_users_registered";
     public const string CounterUsersRegisteredDeleted = "lightless_users_registered_deleted";
+    public const string GaugeLightFinderConnections = "lightless_lightfinder_connections";
+    public const string GaugeLightFinderGroups = "lightless_lightfinder_groups";
     public const string GaugePairs = "lightless_pairs";
     public const string GaugePairsPaused = "lightless_pairs_paused";
     public const string GaugeFilesTotal = "lightless_files";

LightlessSyncServer/LightlessSyncShared/Utils/Configuration/StaticFilesServerConfiguration.cs

@@ -20,6 +20,8 @@ public class StaticFilesServerConfiguration : LightlessConfigurationBase
     public string ColdStorageDirectory { get; set; } = null;
     public double ColdStorageSizeHardLimitInGiB { get; set; } = -1;
     public int ColdStorageUnusedFileRetentionPeriodInDays { get; set; } = 30;
+    public bool EnableDirectDownloads { get; set; } = true;
+    public int DirectDownloadTokenLifetimeSeconds { get; set; } = 300;
     [RemoteConfiguration]
     public double SpeedTestHoursRateLimit { get; set; } = 0.5;
     [RemoteConfiguration]
@@ -40,6 +42,8 @@ public class StaticFilesServerConfiguration : LightlessConfigurationBase
         sb.AppendLine($"{nameof(CacheDirectory)} => {CacheDirectory}");
         sb.AppendLine($"{nameof(DownloadQueueSize)} => {DownloadQueueSize}");
         sb.AppendLine($"{nameof(DownloadQueueReleaseSeconds)} => {DownloadQueueReleaseSeconds}");
+        sb.AppendLine($"{nameof(EnableDirectDownloads)} => {EnableDirectDownloads}");
+        sb.AppendLine($"{nameof(DirectDownloadTokenLifetimeSeconds)} => {DirectDownloadTokenLifetimeSeconds}");
         return sb.ToString();
     }
 }

LightlessSyncServer/LightlessSyncStaticFilesServer/Controllers/ServerFilesController.cs

@@ -10,6 +10,7 @@ using LightlessSyncShared.Services;
 using LightlessSyncShared.Utils.Configuration;
 using LightlessSyncStaticFilesServer.Services;
 using LightlessSyncStaticFilesServer.Utils;
+using Microsoft.AspNetCore.Authorization;
 using Microsoft.AspNetCore.Mvc;
 using Microsoft.AspNetCore.SignalR;
 using Microsoft.EntityFrameworkCore;
@@ -32,12 +33,13 @@ public class ServerFilesController : ControllerBase
     private readonly IDbContextFactory<LightlessDbContext> _lightlessDbContext;
     private readonly LightlessMetrics _metricsClient;
     private readonly MainServerShardRegistrationService _shardRegistrationService;
+    private readonly CDNDownloadUrlService _cdnDownloadUrlService;
 
     public ServerFilesController(ILogger<ServerFilesController> logger, CachedFileProvider cachedFileProvider,
         IConfigurationService<StaticFilesServerConfiguration> configuration,
         IHubContext<LightlessHub> hubContext,
         IDbContextFactory<LightlessDbContext> lightlessDbContext, LightlessMetrics metricsClient,
-        MainServerShardRegistrationService shardRegistrationService) : base(logger)
+        MainServerShardRegistrationService shardRegistrationService, CDNDownloadUrlService cdnDownloadUrlService) : base(logger)
     {
         _basePath = configuration.GetValueOrDefault(nameof(StaticFilesServerConfiguration.UseColdStorage), false)
             ? configuration.GetValue<string>(nameof(StaticFilesServerConfiguration.ColdStorageDirectory))
@@ -48,6 +50,7 @@ public class ServerFilesController : ControllerBase
         _lightlessDbContext = lightlessDbContext;
         _metricsClient = metricsClient;
         _shardRegistrationService = shardRegistrationService;
+        _cdnDownloadUrlService = cdnDownloadUrlService;
     }
 
     [HttpPost(LightlessFiles.ServerFiles_DeleteAll)]
@@ -105,6 +108,16 @@ public class ServerFilesController : ControllerBase
                 baseUrl = shard.Value ?? _configuration.GetValue<Uri>(nameof(StaticFilesServerConfiguration.CdnFullUrl));
             }
 
+            var cdnDownloadUrl = string.Empty;
+            if (forbiddenFile == null)
+            {
+                var directUri = _cdnDownloadUrlService.TryCreateDirectDownloadUri(baseUrl, file.Hash);
+                if (directUri != null)
+                {
+                    cdnDownloadUrl = directUri.ToString();
+                }
+            }
+
             response.Add(new DownloadFileDto
             {
                 FileExists = file.Size > 0,
@@ -113,6 +126,7 @@ public class ServerFilesController : ControllerBase
                 Hash = file.Hash,
                 Size = file.Size,
                 Url = baseUrl?.ToString() ?? string.Empty,
+                CDNDownloadUrl = cdnDownloadUrl,
                 RawSize = file.RawSize
             });
         }
@@ -127,6 +141,30 @@ public class ServerFilesController : ControllerBase
         return Ok(JsonSerializer.Serialize(allFileShards.SelectMany(t => t.RegionUris.Select(v => v.Value.ToString()))));
     }
 
+    [HttpGet(LightlessFiles.ServerFiles_DirectDownload + "/{hash}")]
+    [AllowAnonymous]
+    public async Task<IActionResult> DownloadFileDirect(string hash, [FromQuery] long expires, [FromQuery] string signature)
+    {
+        if (!_cdnDownloadUrlService.DirectDownloadsEnabled)
+        {
+            return NotFound();
+        }
+
+        hash = hash.ToUpperInvariant();
+        if (!_cdnDownloadUrlService.TryValidateSignature(hash, expires, signature))
+        {
+            return Unauthorized();
+        }
+
+        var fileInfo = await _cachedFileProvider.DownloadAndGetLocalFileInfo(hash).ConfigureAwait(false);
+        if (fileInfo == null)
+        {
+            return NotFound();
+        }
+
+        return PhysicalFile(fileInfo.FullName, "application/octet-stream");
+    }
+
     [HttpPost(LightlessFiles.ServerFiles_FilesSend)]
     public async Task<IActionResult> FilesSend([FromBody] FilesSendDto filesSendDto)
     {

LightlessSyncServer/LightlessSyncStaticFilesServer/Services/CDNDownloadUrlService.cs

@@ -0,0 +1,108 @@
+using LightlessSync.API.Routes;
+using LightlessSyncShared.Services;
+using LightlessSyncShared.Utils.Configuration;
+using Microsoft.AspNetCore.Http.Extensions;
+using Microsoft.AspNetCore.WebUtilities;
+using System.Security.Cryptography;
+using System.Text;
+using System.Globalization;
+using System.Linq;
+
+namespace LightlessSyncStaticFilesServer.Services;
+
+public class CDNDownloadUrlService
+{
+    private readonly IConfigurationService<StaticFilesServerConfiguration> _staticConfig;
+    private readonly IConfigurationService<LightlessConfigurationBase> _globalConfig;
+    private readonly ILogger<CDNDownloadUrlService> _logger;
+
+    public CDNDownloadUrlService(IConfigurationService<StaticFilesServerConfiguration> staticConfig,
+        IConfigurationService<LightlessConfigurationBase> globalConfig, ILogger<CDNDownloadUrlService> logger)
+    {
+        _staticConfig = staticConfig;
+        _globalConfig = globalConfig;
+        _logger = logger;
+    }
+
+    public bool DirectDownloadsEnabled =>
+        _staticConfig.GetValueOrDefault(nameof(StaticFilesServerConfiguration.EnableDirectDownloads), false);
+
+    public Uri? TryCreateDirectDownloadUri(Uri? baseUri, string hash)
+    {
+        if (!DirectDownloadsEnabled || baseUri == null)
+        {
+            return null;
+        }
+
+        if (!IsSupportedHash(hash))
+        {
+            _logger.LogDebug("Skipping direct download link generation for invalid hash {hash}", hash);
+            return null;
+        }
+
+        var normalizedHash = hash.ToUpperInvariant();
+
+        var lifetimeSeconds = Math.Max(5,
+            _staticConfig.GetValueOrDefault(nameof(StaticFilesServerConfiguration.DirectDownloadTokenLifetimeSeconds), 300));
+        var expiresAt = DateTimeOffset.UtcNow.AddSeconds(lifetimeSeconds);
+        var signature = CreateSignature(normalizedHash, expiresAt.ToUnixTimeSeconds());
+
+        var directPath = $"{LightlessFiles.ServerFiles}/{LightlessFiles.ServerFiles_DirectDownload}/{normalizedHash}";
+        var builder = new UriBuilder(new Uri(baseUri, directPath));
+        var query = new QueryBuilder
+        {
+            { "expires", expiresAt.ToUnixTimeSeconds().ToString(CultureInfo.InvariantCulture) },
+            { "signature", signature }
+        };
+        builder.Query = query.ToQueryString().Value!.TrimStart('?');
+        return builder.Uri;
+    }
+
+    public bool TryValidateSignature(string hash, long expiresUnixSeconds, string signature)
+    {
+        if (!DirectDownloadsEnabled)
+        {
+            return false;
+        }
+
+        if (string.IsNullOrEmpty(signature) || !IsSupportedHash(hash))
+        {
+            return false;
+        }
+
+        var normalizedHash = hash.ToUpperInvariant();
+
+        DateTimeOffset expiresAt;
+        try
+        {
+            expiresAt = DateTimeOffset.FromUnixTimeSeconds(expiresUnixSeconds);
+        }
+        catch (ArgumentOutOfRangeException)
+        {
+            return false;
+        }
+
+        if (expiresAt < DateTimeOffset.UtcNow)
+        {
+            return false;
+        }
+
+        var expected = CreateSignature(normalizedHash, expiresAt.ToUnixTimeSeconds());
+        return CryptographicOperations.FixedTimeEquals(
+            Encoding.UTF8.GetBytes(expected),
+            Encoding.UTF8.GetBytes(signature));
+    }
+
+    private string CreateSignature(string hash, long expiresUnixSeconds)
+    {
+        var signingKey = _globalConfig.GetValue<string>(nameof(LightlessConfigurationBase.Jwt));
+        using var hmac = new HMACSHA256(Encoding.UTF8.GetBytes(signingKey));
+        var payload = Encoding.UTF8.GetBytes($"{hash}:{expiresUnixSeconds}");
+        return WebEncoders.Base64UrlEncode(hmac.ComputeHash(payload));
+    }
+
+    private static bool IsSupportedHash(string hash)
+    {
+        return hash.Length == 40 && hash.All(char.IsAsciiLetterOrDigit);
+    }
+}

LightlessSyncServer/LightlessSyncStaticFilesServer/Startup.cs

@@ -87,6 +87,7 @@ public class Startup
         services.AddSingleton<RequestFileStreamResultFactory>();
         services.AddSingleton<ServerTokenGenerator>();
         services.AddSingleton<RequestQueueService>();
+        services.AddSingleton<CDNDownloadUrlService>();
         services.AddHostedService(p => p.GetService<RequestQueueService>());
         services.AddHostedService(m => m.GetService<FileStatisticsService>());
         services.AddSingleton<IConfigurationService<LightlessConfigurationBase>, LightlessConfigurationServiceClient<LightlessConfigurationBase>>();

LightlessSyncServer/LightlessSyncStaticFilesServer/appsettings.json

@@ -25,7 +25,9 @@
     "UnusedFileRetentionPeriodInDays": 7,
     "CacheDirectory": "G:\\ServerTest",
     "ServiceAddress": "http://localhost:5002",
-    "RemoteCacheSourceUri": ""
+    "RemoteCacheSourceUri": "",
+    "EnableDirectDownloads": true,
+    "DirectDownloadTokenLifetimeSeconds": 300
   },
   "AllowedHosts": "*"
 }