Change report from Azbil Corporation.

[Toshihisa-Fujii]

Proposed changes

Our company would like to make the following changes as requirements for incorporating the product when using UA Stack .NET Standard. As stipulated by the RCL license, we will communicate the changes in this pull request.

• Add a validity period check for authentication using certificates.
• Ensure that DateTime data exchanged in request and response messages can only be used in UTC by the user.

Related Issues

• Fixes #
  (None.)

Types of changes

What types of changes does your code introduce?
Put an x in the boxes that apply. You can also fill these out after creating the PR.

• 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

Put an x in the boxes that apply. You can also fill these out after creating the PR. If you're unsure about any of them, don't hesitate to ask. We're here to help! This is simply a reminder of what we are going to look for before merging your code.

• I have read the CONTRIBUTING doc.
• 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

In addition to the above changes, our company has locally modified following file.
Stack/Opc.Ua.Core/Types/Utils/Utils.cs
The purpose of this modification is to align the log output format with our company's standards. However, since this change does not provide any benefits to the OPCF, it is excluded from this pull request. If it is necessary to push the changes to that file as well, please let us know.

[CLAassistant]

All committers have signed the CLA.

[EthanChangAED]

Hello @Toshihisa-Fujii , thank you for submitting this PR. We will review it.

[mregen]

please see my comment, it is not quite right to comment out the conversion to UTC time.

[mregen]

This line should not be removed. It makes sure only UTC normalized timestamps are sent over the wire. If there is a timestamp off, there is maybe an application error, that a DateTime is created without Utc kind.

[Toshihisa-Fujii]

Thank you for your comment. I understand that my coding regarding DateTime class was insufficient. I agree.

[marcschier]

@Toshihisa-Fujii , Can you provide more information as to what the change fixes or brings as valuable additions to the stack, so we better can judge whether breaking compatibility (see checkbox) is justified.

[Toshihisa-Fujii]

As for the change item 'Ensure that DateTime data exchanged in request and response messages can only be used in UTC by the user.', I noticed that I misunderstood because of the comment from https://github.com/mregen. So please ignore it.
As for 'Add a validity period check for authentication using certificates.', I added a method to retrieve only non-expired certificates from the certificate store. The reason for this is that my company required a specification to check the validity period of certificates in the authentication process using certificates.