lightfinder changes:

- removed all ability to provide your cid to the server through params, cid is gained from JWT claims - improved verification of who owns a cid, which includes locking a cid to a uid - locks and persisting entries of broadcasting are cleaned up on disconnection - method identification logic was rewritten to fit these changes
2025-10-08 08:40:56 +09:00
parent 43219dd1e9
commit 479b80a5a0
9 changed files with 243 additions and 87 deletions
--- a/2
+++ b/2
--- a/LightlessSyncServer/LightlessSyncServer/Configuration/BroadcastConfiguration.cs
+++ b/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;
 }
--- a/LightlessSyncServer/LightlessSyncServer/Configuration/BroadcastOptions.cs
+++ b/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;
 }
--- a/LightlessSyncServer/LightlessSyncServer/Configuration/IBroadcastConfiguration.cs
+++ b/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; }
 }
--- a/LightlessSyncServer/LightlessSyncServer/Hubs/LightlessHub.Functions.cs
+++ b/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)
--- a/LightlessSyncServer/LightlessSyncServer/Hubs/LightlessHub.Groups.cs
+++ b/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 existingJoinedGroups = await DbContext.GroupPairs.CountAsync(u => u.GroupUserUID == 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: 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.GroupPairs.AddAsync(initialPair, _contextAccessor.HttpContext.RequestAborted).ConfigureAwait(false);
-        await DbContext.GroupPairPreferredPermissions.AddAsync(initialPrefPermissions, _contextAccessor.HttpContext.RequestAborted).ConfigureAwait(false);
-        await DbContext.SaveChangesAsync(_contextAccessor.HttpContext.RequestAborted).ConfigureAwait(false);
+        await DbContext.Groups.AddAsync(newGroup, RequestAbortedToken).ConfigureAwait(false);
+        await DbContext.GroupPairs.AddAsync(initialPair, RequestAbortedToken).ConfigureAwait(false);
+        await DbContext.GroupPairPreferredPermissions.AddAsync(initialPrefPermissions, RequestAbortedToken).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 joinedGroups = await DbContext.GroupPairs.CountAsync(g => g.GroupUserUID == UserUID, cancellationToken: _contextAccessor.HttpContext.RequestAborted).ConfigureAwait(false);
-        var isBanned = await DbContext.GroupBans.AnyAsync(g => g.GroupGID == groupGid && g.BannedUserUID == UserUID, cancellationToken: _contextAccessor.HttpContext.RequestAborted).ConfigureAwait(false);
-        var oneTimeInvite = await DbContext.GroupTempInvites.SingleOrDefaultAsync(g => g.GroupGID == groupGid && g.Invite == hashedPw, 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: RequestAbortedToken).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: 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;
        }

@@ -743,7 +743,7 @@ 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)
@@ -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
@@ -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"));
    }
@@ -991,5 +991,4 @@ public partial class LightlessHub
        return results;
    }

-
 }
--- a/LightlessSyncServer/LightlessSyncServer/Hubs/LightlessHub.User.cs
+++ b/LightlessSyncServer/LightlessSyncServer/Hubs/LightlessHub.User.cs
@@ -1,4 +1,4 @@
-using LightlessSync.API.Data;
+using LightlessSync.API.Data;
 using LightlessSync.API.Data.Enum;
 using LightlessSync.API.Data.Extensions;
 using LightlessSync.API.Dto.Group;
@@ -35,7 +35,7 @@ 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 +51,7 @@ 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)
        {
@@ -60,7 +60,7 @@ public partial class LightlessHub
        }

        // grab self create new client pair and save
-        var user = await DbContext.Users.SingleAsync(u => u.UID == UserUID, cancellationToken: _contextAccessor.HttpContext.RequestAborted).ConfigureAwait(false);
+        var user = await DbContext.Users.SingleAsync(u => u.UID == UserUID, cancellationToken: RequestAbortedToken).ConfigureAwait(false);

        _logger.LogCallInfo(LightlessHubLogger.Args(dto, "Success"));

@@ -76,7 +76,7 @@ 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 +89,7 @@ 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 +143,15 @@ 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 (!IsValidCid(myCid) || !IsValidCid(otherCid))
-        {
+        if (!IsValidHashedCid(myCid) || !IsValidHashedCid(otherCid))
            return;
-        }

        if (string.Equals(otherCid, myCid, StringComparison.Ordinal))
        {
@@ -181,12 +179,33 @@ 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 +270,30 @@ 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 +302,16 @@ 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 +365,7 @@ 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 +381,10 @@ 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 +392,9 @@ 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 +406,32 @@ 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 +466,7 @@ 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 +480,7 @@ 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 +503,35 @@ 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 +539,13 @@ 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 +582,16 @@ 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 +664,7 @@ 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 (!validHash)
+            if (!IsValidHashedCid(cid))
            {
                tasks[cid] = Task.FromResult(new RedisValueWithExpiry(RedisValue.Null, null));
                continue;
@@ -657,7 +732,7 @@ 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 +785,7 @@ 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 +942,7 @@ 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 +993,7 @@ 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)
        {
--- a/LightlessSyncServer/LightlessSyncServer/Hubs/LightlessHub.cs
+++ b/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);
--- a/LightlessSyncServer/LightlessSyncServer/appsettings.json
+++ b/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": {