Null Reference Exception in UaSCUaBinaryChannel.WriteSymmetricMessage after Client disconnect

[romanett]

Type of issue

• Bug
• Enhancement
• Compliance
• Question
• Help wanted

Current Behavior

The UaSCUaBinaryChannel.WriteSymmetricMessage throws an exception here:

UA-.NETStandard/Stack/Opc.Ua.Core/Stack/Tcp/UaSCBinaryChannel.Symmetric.cs

Line 613 in ef9387b

encoder.WriteUInt32(null, token.TokenId);

as the token is null.

This occurs when the Client is shut down.

Expected Behavior

No Exception is thrown.

Maybe 0? should be written if no token is present?

Steps To Reproduce

1. Start Reference Server
2. Start Reference Client
3. Stop Reference Client while communication is in progress
4. Exception is thrown
   

   UA-.NETStandard/Stack/Opc.Ua.Core/Stack/Tcp/UaSCBinaryChannel.Symmetric.cs

   Line 613 in ef9387b

   encoder.WriteUInt32(null, token.TokenId);

Also occurs on the sheduled client disconnect

Environment

- OS: Windows 11
- Environment: Visual Studio 2022
- Runtime: Net 9
- Nuget Version: Current Master
- Component: Server
- Server: Current Master Reference Server
- Client: Current Master Reference Client

Anything else?

MesageBody: {Opc.Ua.ServiceFault}
MessageType: 4674381
isRequest: false

[romanett]

Could be related to Token Dispose PR

[romanett]

This TCP message type is none of the known OPC UA Message Types.

The Server wants to send a {BadSessionClosed} Response. However the token of the channel seems to be already disposed

[romanett]

This seems to be a general issue in handling this kind of disconnect.

If the line above is fixed the symmetric sign fails:

IMHO the server shall just stop processing the message, as it is not needed any more