Implement X509Certificate2.RawDataMemory

[vcsjones]

Closes #57448

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Issue Details

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Closes #57448

Author:	vcsjones
Assignees:	-
Labels:	area-System.Security, new-api-needs-documentation
Milestone:	-

[vcsjones]

I didn't go with the custom MemoryManager trick. For one I would probably have a difficult time figuring out how to do it correctly, and for two because it still feels a bit unnecessary to me. MemoryMarshal is an "I know what I am doing" type, and even if we did do it, it would not address the pinning possibility.

[GrabYourPitchforks]

Should we doc that the returned ROM<byte> has an independent lifetime from the underlying certificate? ROM<byte> is supposed to be an abstraction, but we're returning a property whose correct usage relies on the buffer having an independent lifetime, and people will absolutely depend on this behavior. Might be worthwhile to formalize this expectation in docs.

[vcsjones]

@GrabYourPitchforks

Should we doc that the returned ROM<byte> has an independent lifetime from the underlying certificate?

What would documentation like that look like? I... think... given the API shape it's a reasonable expectation (otherwise it'd be a CopyRawDataTo(..) or something like that.

Would codifying in a test be more reasonable, or is that not strong enough? (I'm starting to think the test should exist regardless... let me add that).

[GrabYourPitchforks]

Would codifying in a test be more reasonable, or is that not strong enough?

That's probably good enough honestly. Get the ROM<byte>, dispose the cert, then validate the buffer you previously got is still filled with delicious X.509 goodness.

[stephentoub]

It's quite rare to see someone use == with spans and have it actually be correct ;-)

[GrabYourPitchforks]

Thanks also for the unit test update!