Hello,

you are right, security policies Aes128_Sha256_RsaOaep and Aes256_Sha256_RsaPss are, as of now (with QuickOPC 2021.1), only supported under .NET Core and .NET 5, and not under .NET Framework (4.7-4.. The QuickOPC COM layer (which include unmanaged C++ support) is implemented on top of the .NET Framework, and therefore these security policies are not available through QuickOPC COM.

The reason for this is that QuickOPC relies on the low-level OPC UA stack code from OPC Foundation. And the stack code for .NET Framework is marked "legacy" and no longer actively maintained.

It is unlikely that AES security policies will ever be added to the legacy .NET Stack, and therefore, it is unlikely that they will ever be available in QuickOPC for .NET Framework or QuickOPC COM.

The way forward will probably be to provide QuickOPC COM on top of .NET Core/.NET 5+. We cannot do it currently (at least not directly), because although Microsoft claims to support creation of COM Servers in .NET Core /.NET 5+, they have not done it in full. Specifically, generation of COM type libraries from the .NET assemblies is missing. We need to wait whether they will add it in reasonable time. I can foresee 3 possible outcomes:

a) Microsoft will provide a full support for development of COM Server objects under .NET 5+ in reasonable time [* see below]. If/when this happens, we will use it, and at that time we will provide QuickOPC COM that would work over .NET 5+, and will thus use the newer OPC UA stack and will have the AES security policies.

b) If Microsoft does not provide that in time, we will try to make it work anyway somehow - which is much more work, and it may fail, If successful, that is what we will provide.

c) If b) also fails, there will not be a newer version of what you asking for, and the new policies will not be implemented.

[*] The "reasonable time" is unknown. But it is quite long. We do not see a significant pressure from the user base. I would say 1 year at least.

Best regards