[Server] update endpoint descriptions after certificate update

[romanett]

Proposed changes

Update the Server Endpoint Descriptions after certificate update e.g. from a GDS Push. Until this PR this needed a resart.

Confirmed working with the Discovery client and this code:

var endpoint = DiscoveryClient.Create(new Uri("opc.tcp://localhost:62541/Quickstarts/ReferenceServer"))
                .GetEndpoints(null)
                .First(endpoint => endpoint.ServerCertificate != null);

X509Certificate2 endpointCertificate = Utils.ParseCertificateBlob(endpoint.ServerCertificate);

Related Issues

• Fixes #1801

Types of changes

• [x] Bugfix (non-breaking change which fixes an issue)
• [ ] Enhancement (non-breaking change which adds functionality)
• [ ] Test enhancement (non-breaking change to increase test coverage)
• [ ] Breaking change (fix or feature that would cause existing functionality to not work as expected, requires version increase of Nuget packages)
• [ ] Documentation Update (if none of the other choices apply)

Checklist

• [x] I have read the CONTRIBUTING doc.
• [x] I have signed the CLA.
• [ ] I ran tests locally with my changes, all passed.
• [ ] I fixed all failing tests in the CI pipelines.
• [ ] I fixed all introduced issues with CodeQL and LGTM.
• [ ] I have added tests that prove my fix is effective or that my feature works and increased code coverage.
• [ ] I have added necessary documentation (if appropriate).
• [ ] Any dependent changes have been merged and published in downstream modules.

Further comments

[codecov[bot]]

Codecov Report

Attention: Patch coverage is 81.42857% with 13 lines in your changes missing coverage. Please review.

Project coverage is 54.66%. Comparing base (cf2e788) to head (b98517b).

Files with missing lines	Patch %	Lines
...ndings.Https/Stack/Https/HttpsTransportListener.cs	0.00%	7 Missing :warning:
Stack/Opc.Ua.Core/Stack/Server/ServerBase.cs	89.47%	2 Missing and 2 partials :warning:
Stack/Opc.Ua.Core/Types/Utils/Utils.cs	81.81%	1 Missing and 1 partial :warning:

Additional details and impacted files

```diff @@ Coverage Diff @@ ## master #2735 +/- ## ========================================== - Coverage 55.04% 54.66% -0.39% ========================================== Files 349 349 Lines 65697 65673 -24 Branches 13441 13428 -13 ========================================== - Hits 36162 35899 -263 - Misses 25688 25875 +187 - Partials 3847 3899 +52 ```

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[mregen]

There are a few helper defined already, e.g. in CertificateIdentifier.ParseBlob and CertificateIdentifier.CreateBlob, just as an example for the API. There is also Utils.ParseCertificateChainBlob() and Utils.ParseCertificateBlob(), you could provide a generic function to create a blob. The CertificateIdentifier Parse/Create code is not used much afaik (maybe in a GDS app?) and can be marked obsolete and removed in a while.

[mregen]

Please check also the CertificateUpdate methods in HttpsTransportListenerand TcpTransportListener. The way the descriptions are updated also seems not quite right?

[romanett]

There are a few helper defined already, e.g. in CertificateIdentifier.ParseBlob and CertificateIdentifier.CreateBlob, just as an example for the API. There is also Utils.ParseCertificateChainBlob() and Utils.ParseCertificateBlob(), you could provide a generic function to create a blob. The CertificateIdentifier Parse/Create code is not used much afaik (maybe in a GDS app?) and can be marked obsolete and removed in a while.

I could not find any usage of CertificateIdentified ParseBlob /CreateBlob. I will mark them obsolete and instead point to Utils. ParseCertificateChainBlob() / create Utils.CreateCertificateChainBlob

[romanett]

Please check also the CertificateUpdate methods in HttpsTransportListenerand TcpTransportListener. The way the descriptions are updated also seems not quite right?

On startup the CertificateChain is Initialized always to the full chain, only on certificate update an empty CertificateChain is constructed. I will switch to this to ensure consistent behaviour of the property also after certificate update.

Why does Session have a Property ServerCertificateChain that is never actually initialized with the ServerCertificateChain, can it be removed?