Create options pattern for providing an XmlRepository for storing Data Protection keys.

[MrNathanStiles]

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.

There are several options for key persistence but none are generic. It would be beneficial to have a IXmlRepositoryProvider or something like what we have with ILoggerProvider. I think the existing option, KeyManagementOptions.XmlRepository, allows this but that property isn't really an option. The issue @ #2505
exposes the problem in the comment @ #2505 (comment)
We have no way to resolve services to be used as an XmlRepository

Describe the solution you'd like

Implement options pattern to provide an XmlRepository.

Additional context

No response

[justindbaur]

This is how PersistKeysToDbContext works while getting access to services:

aspnetcore/src/DataProtection/EntityFrameworkCore/src/EntityFrameworkCoreDataProtectionExtensions.cs

Lines 24 to 34 in 31d5a5f

	public static IDataProtectionBuilder PersistKeysToDbContext<TContext>(this IDataProtectionBuilder builder)
	where TContext : DbContext, IDataProtectionKeyContext
	{
	builder.Services.AddSingleton<IConfigureOptions<KeyManagementOptions>>(services =>
	{
	var loggerFactory = services.GetService<ILoggerFactory>() ?? NullLoggerFactory.Instance;
	return new ConfigureOptions<KeyManagementOptions>(options =>
	{
	options.XmlRepository = new EntityFrameworkCoreXmlRepository<TContext>(services, loggerFactory);
	});
	});

Would that work for your use?

[MrNathanStiles]

Yes that does work. Thanks!