Define a pattern for a component that ensures a data protection keyring has an active key

[amcasey]

Is there an existing issue for this?

• I have searched the existing issues

Is your feature request related to a problem? Please describe the problem.

Same as #52915. We want to separate keyring reads from keyring writes to avoid races when there are multiple consumers. If we make consumers read-only, we need a dedicated writer to ensure there's an active key in a newly-created keyring and an unexpired key in an existing one.

Describe the solution you'd like

We could make a simple command-line executable that can be run either periodically or on a dynamic schedule. It needs only basic data protection functionality:

1. Read the existing keyring, if any
2. Generate a new key if there isn't one or if the active one is near/past expiration
3. Revoke all keys (we probably don't want to deal with the complexity of specifying particular keys to revoke)
4. Delete long-unused keys to avoid unbounded keyring growth
5. Output the next time it should be run (if it's not going to happen on a fixed cadence)

Additional context

For compatibility, this component basically has to consume the existing Data Protection APIs. That effectively locks us to C#, but our Data Protection usage should be simple enough to allow AOT for consumers that don't have a CLR available.

We probably don't want to expose an API for all the possible storage locations of the keyring, so it will probably just be a path.

It's not yet clear whether this will be a reusable component or merely a sample/template that can be customized per-application.

[Tratcher]

This could be a comparable tool to dotnet-ef that used all of the configuration from the current project but ignored the read-only flag. That way it could support all the different types of data stores without additional configuration (e.g. key-vault, EF, files, custom). https://learn.microsoft.com/en-us/ef/core/cli/dotnet

edit project integration might make less sense if this is primarily intended for use in production.

[ghost]

Thanks for contacting us.

We're moving this issue to the .NET 9 Planning milestone for future evaluation / consideration. We would like to keep this around to collect more feedback, which can help us with prioritizing this work. We will re-evaluate this issue, during our next planning meeting(s).
If we later determine, that the issue has no community involvement, or it's very rare and low-impact issue, we will close it - so that the team can focus on more important and high impact issues.
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[amcasey]

The proof-of-concept system seems to be working, so we should probably write this up.

[amcasey]

I put some draft text here.