Fix encryption alert write during TLS handshake

src/DotNetty.Handlers/Tls/TlsHandler.Handshake.cs

@@ -43,6 +43,7 @@ namespace DotNetty.Handlers.Tls
     partial class TlsHandler
     {
         private static readonly Action<object, object> s_handshakeCompletionCallback = (t, s) => HandleHandshakeCompleted((Task)t, (TlsHandler)s);
+        private static readonly TaskCanceledException s_taskCanceledException = new TaskCanceledException();
         public static readonly AttributeKey<SslStream> SslStreamAttrKey = AttributeKey<SslStream>.ValueOf("SSLSTREAM");
 
         private bool EnsureAuthenticated(IChannelHandlerContext ctx)
@@ -215,9 +216,9 @@ private static void HandleHandshakeCompleted(Task task, TlsHandler self)
                 var cause = taskExc.Unwrap();
                 try
                 {
-                    if (self._handshakePromise.TrySetException(taskExc))
+                    if (task.IsFaulted ? self._handshakePromise.TrySetException(taskExc) : self._handshakePromise.TrySetCanceled())
                     {
-                        TlsUtils.NotifyHandshakeFailure(capturedContext, cause, true);
+                        TlsUtils.NotifyHandshakeFailure(capturedContext, task.IsFaulted ? cause : s_taskCanceledException, true);
                     }
                 }
                 finally

src/DotNetty.Handlers/Tls/TlsHandler.MediationStream.NetCore.cs

@@ -177,10 +177,10 @@ private int ReadFromInput(Memory<byte> destination) // byte[] destination, int d
             }
 
             public override void Write(ReadOnlySpan<byte> buffer)
-                => _owner.FinishWrap(buffer, _owner._lastContextWritePromise);
+                => _owner.FinishWrap(buffer, _owner._lastContextWritePromise ?? _owner.CapturedContext.NewPromise());
 
             public override void Write(byte[] buffer, int offset, int count)
-                => _owner.FinishWrap(buffer, offset, count, _owner._lastContextWritePromise);
+                => _owner.FinishWrap(buffer, offset, count, _owner._lastContextWritePromise ?? _owner.CapturedContext.NewPromise());
 
             public override ValueTask WriteAsync(ReadOnlyMemory<byte> buffer, CancellationToken cancellationToken = default)
             {

src/DotNetty.Handlers/Tls/TlsHandler.MediationStream.NetFx.cs

@@ -145,7 +145,7 @@ private int ReadFromInput(byte[] destination, int destinationOffset, int destina
                 return length;
             }
 
-            public override void Write(byte[] buffer, int offset, int count) => _owner.FinishWrap(buffer, offset, count, _owner._lastContextWritePromise);
+            public override void Write(byte[] buffer, int offset, int count) => _owner.FinishWrap(buffer, offset, count, _owner._lastContextWritePromise ?? _owner.CapturedContext.NewPromise());
 
             public override Task WriteAsync(byte[] buffer, int offset, int count, CancellationToken cancellationToken)
                 => _owner.FinishWrapNonAppDataAsync(buffer, offset, count, _owner.CapturedContext.NewPromise());

src/DotNetty.Handlers/Tls/TlsHandler.MediationStream.NetStandard20.cs

@@ -108,7 +108,7 @@ private int ReadFromInput(byte[] destination, int destinationOffset, int destina
                 return length;
             }
 
-            public override void Write(byte[] buffer, int offset, int count) => _owner.FinishWrap(buffer, offset, count, _owner._lastContextWritePromise);
+            public override void Write(byte[] buffer, int offset, int count) => _owner.FinishWrap(buffer, offset, count, _owner._lastContextWritePromise ?? _owner.CapturedContext.NewPromise());
 
             public override Task WriteAsync(byte[] buffer, int offset, int count, CancellationToken cancellationToken)
                 => _owner.FinishWrapNonAppDataAsync(buffer, offset, count, _owner.CapturedContext.NewPromise());