increase security on webfront cookie state/update events

WebfrontCore/Middleware/ClaimsPermissionRemoval.cs

@@ -1,4 +1,6 @@
-using Microsoft.AspNetCore.Authentication;
+using System;
+using System.Collections.Concurrent;
+using Microsoft.AspNetCore.Authentication;
 using Microsoft.AspNetCore.Http;
 using SharedLibraryCore;
 using SharedLibraryCore.Interfaces;
@@ -8,6 +10,7 @@ using System.Security.Claims;
 using System.Threading.Tasks;
 using Data.Models.Client;
 using Microsoft.AspNetCore.Authentication.Cookies;
+using SharedLibraryCore.Commands;
 using static SharedLibraryCore.GameEvent;
 
 namespace WebfrontCore.Middleware
@@ -18,68 +21,25 @@ namespace WebfrontCore.Middleware
     internal class ClaimsPermissionRemoval
     {
         private readonly IManager _manager;
-        private readonly List<int> _privilegedClientIds;
+        private static readonly ConcurrentDictionary<int, (ClaimsState, DateTimeOffset?)> PrivilegedClientIds = new();
         private readonly RequestDelegate _nextRequest;
 
+        private enum ClaimsState
+        {
+            Current,
+            Tainted
+        }
+
         public ClaimsPermissionRemoval(RequestDelegate nextRequest, IManager manager)
         {
             _manager = manager;
             _manager.OnGameEventExecuted += OnGameEvent;
-            _privilegedClientIds = new List<int>();
             _nextRequest = nextRequest;
         }
 
-        /// <summary>
-        /// Callback for the game event 
-        /// </summary>
-        /// <param name="sender"></param>
-        /// <param name="gameEvent"></param>
-        private void OnGameEvent(object sender, GameEvent gameEvent)
-        {
-            if (gameEvent.Type != EventType.ChangePermission || gameEvent.Extra is not EFClient.Permission perm)
-            {
-                return;
-            }
-
-            lock (_privilegedClientIds)
-            {
-                switch (perm)
-                {
-                    // we want to remove the claims when the client is demoted
-                    case < EFClient.Permission.Trusted:
-                    {
-                        _privilegedClientIds.RemoveAll(id => id == gameEvent.Target.ClientId);
-                        break;
-                    }
-                    // and add if promoted
-                    case > EFClient.Permission.Trusted when !_privilegedClientIds.Contains(gameEvent.Target.ClientId):
-                    {
-                        _privilegedClientIds.Add(gameEvent.Target.ClientId);
-                        break;
-                    }
-                }
-            }
-        }
-
         public async Task Invoke(HttpContext context)
         {
-            // we want to load the initial list of privileged clients
-            bool hasAny;
-            lock (_privilegedClientIds)
-            {
-                hasAny = _privilegedClientIds.Any();
-            }
-
-            if (!hasAny)
-            {
-                var ids = (await _manager.GetClientService().GetPrivilegedClients())
-                    .Select(client => client.ClientId);
-
-                lock (_privilegedClientIds)
-                {
-                    _privilegedClientIds.AddRange(ids);
-                }
-            }
+            await Initialize();
 
             // sid stores the clientId
             var claimsId = context.User.Claims.FirstOrDefault(claim => claim.Type == ClaimTypes.Sid)?.Value;
@@ -87,14 +47,16 @@ namespace WebfrontCore.Middleware
             if (!string.IsNullOrEmpty(claimsId))
             {
                 var clientId = int.Parse(claimsId);
-                bool hasKey;
-                lock (_privilegedClientIds)
+                bool isTainted;
+                bool hasPrivilege;
+
+                lock (PrivilegedClientIds)
                 {
-                    hasKey = _privilegedClientIds.Contains(clientId);
+                    hasPrivilege = PrivilegedClientIds.ContainsKey(clientId);
+                    isTainted = hasPrivilege && PrivilegedClientIds[clientId].Item1 == ClaimsState.Tainted;
                 }
 
-                // they've been removed
-                if (!hasKey && clientId != 1)
+                if (!hasPrivilege || isTainted)
                 {
                     await context.SignOutAsync(CookieAuthenticationDefaults.AuthenticationScheme);
                 }
@@ -102,5 +64,141 @@ namespace WebfrontCore.Middleware
 
             await _nextRequest.Invoke(context);
         }
+
+        private void OnGameEvent(object sender, GameEvent gameEvent)
+        {
+            if (gameEvent.Extra?.GetType() == typeof(SetPasswordCommand))
+            {
+                lock (PrivilegedClientIds)
+                {
+                    PrivilegedClientIds[gameEvent.Origin.ClientId] = (ClaimsState.Tainted, DateTimeOffset.UtcNow);
+                }
+
+                return;
+            }
+
+            if (gameEvent.Type != EventType.ChangePermission || gameEvent.Extra is not EFClient.Permission perm)
+            {
+                return;
+            }
+
+            lock (PrivilegedClientIds)
+            {
+                switch (perm)
+                {
+                    // we want to remove the claims when the client is demoted
+                    case < EFClient.Permission.Trusted when PrivilegedClientIds.ContainsKey(gameEvent.Target.ClientId):
+                    {
+                        PrivilegedClientIds.Remove(gameEvent.Target.ClientId, out _);
+                        break;
+                    }
+                    // and add if promoted
+                    case > EFClient.Permission.Trusted:
+                    {
+                        if (!PrivilegedClientIds.ContainsKey(gameEvent.Target.ClientId))
+                        {
+                            PrivilegedClientIds.TryAdd(gameEvent.Target.ClientId, (ClaimsState.Current, null));
+                        }
+                        else
+                        {
+                            // they've been intra-moted, so we need to taint their claims
+                            PrivilegedClientIds[gameEvent.Target.ClientId] =
+                                (ClaimsState.Tainted, DateTimeOffset.UtcNow);
+                        }
+
+                        break;
+                    }
+                }
+            }
+        }
+
+        private async Task Initialize()
+        {
+            // we want to load the initial list of privileged clients
+            bool hasAny;
+            lock (PrivilegedClientIds)
+            {
+                hasAny = PrivilegedClientIds.Any();
+            }
+
+            if (!hasAny)
+            {
+                var ids = (await _manager.GetClientService().GetPrivilegedClients())
+                    .Select(client => client.ClientId);
+
+                lock (PrivilegedClientIds)
+                {
+                    foreach (var id in ids)
+                    {
+                        PrivilegedClientIds.TryAdd(id, (ClaimsState.Current, null));
+                    }
+                }
+            }
+        }
+
+        public static async Task ValidateAsync(CookieValidatePrincipalContext context)
+        {
+            if (context.Principal is null)
+            {
+                return;
+            }
+
+            var claimsId = context.Principal.Claims.FirstOrDefault(claim => claim.Type == ClaimTypes.Sid)?.Value;
+
+            if (string.IsNullOrEmpty(claimsId))
+            {
+                return;
+            }
+
+            var clientId = int.Parse(claimsId);
+
+            bool shouldSignOut;
+
+            lock (PrivilegedClientIds)
+            {
+                // we want to log them out if they aren't in the privileged clients list
+                // or the token is tainted or the taint event occured after the token was generated
+                shouldSignOut = PrivilegedClientIds.ContainsKey(clientId) &&
+                                (PrivilegedClientIds[clientId].Item1 == ClaimsState.Tainted ||
+                                 PrivilegedClientIds[clientId].Item2 is not null &&
+                                 PrivilegedClientIds[clientId].Item2.Value - context.Properties.IssuedUtc >
+                                 TimeSpan.FromSeconds(30));
+            }
+
+            if (shouldSignOut)
+            {
+                context.RejectPrincipal();
+                await context.HttpContext.SignOutAsync(CookieAuthenticationDefaults.AuthenticationScheme);
+            }
+        }
+
+        public static Task OnSignedIn(CookieSignedInContext context)
+        {
+            if (context.Principal is null)
+            {
+                return Task.CompletedTask;
+            }
+
+            var claimsId = context.Principal.Claims.FirstOrDefault(claim => claim.Type == ClaimTypes.Sid)?.Value;
+
+            if (string.IsNullOrEmpty(claimsId))
+            {
+                return Task.CompletedTask;
+            }
+
+            var clientId = int.Parse(claimsId);
+
+            lock (PrivilegedClientIds)
+            {
+                if (PrivilegedClientIds.ContainsKey(clientId))
+                {
+                    PrivilegedClientIds[clientId] = PrivilegedClientIds[clientId].Item1 == ClaimsState.Tainted
+                        ? (ClaimsState.Current, DateTimeOffset.UtcNow)
+                        : (ClaimsState.Current, null);
+                }
+            }
+
+            return Task.CompletedTask;
+        }
     }
 }