macOS: Set certificate as a dependency of private key handles

[vcsjones]

The SafeSecKeyRefHandle needs the certificate and its keychain alive for as long as it exists on macOS.

This sets the certificate, not the identity, as a parent handle of the private key.

Fixes #94959

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Issue Details

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The SafeSecKeyRefHandle needs the certificate and its keychain alive for as long as it exists on macOS.

This sets the certificate, not the identity, as a parent handle of the private key.

Fixes #94959

Author:	vcsjones
Assignees:	-
Labels:	area-System.Security
Milestone:	-

[tore-hammervoll]

Any news on when this fix will be released? This is currently blocking the upgrade from .Net 6/7 to .Net 8, as we can't develop on macOS.

[vcsjones]

@tore-hammervoll currently this is only fixed for .NET 9. Can you open a new issue asking that this fix be back ported to .NET 8, and indicate that it is preventing you from moving to .NET 8?

[tore-hammervoll]

@vcsjones I never got around to making that issue. Thanks for getting this fix backported so quickly!