Add timeout to Negotiate (#736)

src/Microsoft.AspNetCore.SignalR/HubEndPoint.cs

@@ -27,6 +27,7 @@ namespace Microsoft.AspNetCore.SignalR
     {
         private static readonly Base64Encoder Base64Encoder = new Base64Encoder();
         private static readonly PassThroughEncoder PassThroughEncoder = new PassThroughEncoder();
+        private static readonly TimeSpan NegotiateTimeout = TimeSpan.FromSeconds(5);
 
         private readonly Dictionary<string, HubMethodDescriptor> _methods = new Dictionary<string, HubMethodDescriptor>(StringComparer.OrdinalIgnoreCase);
 
@@ -108,7 +109,12 @@ namespace Microsoft.AspNetCore.SignalR
 
         private async Task<bool> ProcessNegotiate(HubConnectionContext connection)
         {
-            while (await connection.Input.WaitToReadAsync())
+            try
+            {
+                using (var cts = new CancellationTokenSource())
+                {
+                    cts.CancelAfter(NegotiateTimeout);
+                    while (await connection.Input.WaitToReadAsync(cts.Token))
                     {
                         while (connection.Input.TryRead(out var buffer))
                         {
@@ -137,6 +143,12 @@ namespace Microsoft.AspNetCore.SignalR
                             }
                         }
                     }
+                }
+            }
+            catch (OperationCanceledException)
+            {
+                _logger.LogDebug("Negotiate was canceled.");
+            }
 
             return false;
         }

test/Microsoft.AspNetCore.SignalR.Tests/HubEndpointTests.cs

@@ -59,6 +59,21 @@ namespace Microsoft.AspNetCore.SignalR.Tests
             }
         }
 
+        [Fact]
+        public async Task NegotiateTimesOut()
+        {
+            var serviceProvider = CreateServiceProvider();
+            var endPoint = serviceProvider.GetService<HubEndPoint<SimpleHub>>();
+
+            using (var client = new TestClient())
+            {
+                // TestClient automatically writes negotiate, for this test we want to assume negotiate never gets sent
+                client.Connection.Transport.In.TryRead(out var item);
+
+                await endPoint.OnConnectedAsync(client.Connection).OrTimeout(TimeSpan.FromSeconds(10));
+            }
+        }
+
         [Fact]
         public async Task LifetimeManagerOnDisconnectedAsyncCalledIfLifetimeManagerOnConnectedAsyncThrows()
         {