Force pin prompt not working

[RufusJWB]

If what you're looking to do is reset the "I've collected the PIN" state, you can do that by

private static void ForcePinPrompt(CngKey key)
{
    key.SetProperty(new CngProperty("SmartCardPin", Array.Empty<byte>(), CngPropertyOptions.None));
}

private static void ForcePinPrompt(RSA key)
{
    if (key is RSACng rsaCng)
    {
        ForcePinPrompt(key.Key);
    }
}

... at least for a key created with ForceHighProtection.  Normal PIN prompting seems to still be cached with that.  Hm. 

Originally posted by @bartonjs in #79338

This is not working for me, but produces an exception with this content:

System.Security.Cryptography.CryptographicException
  HResult=0x8010006B
  Message=The card cannot be accessed because the wrong PIN was presented.
  Source=System.Security.Cryptography
  StackTrace:
   at System.Security.Cryptography.CngKey.SetProperty(CngProperty property)
   at Benchmark.X509Certificate2Extension.ForcePinPrompt(CngKey key) in 

Do you have any idea how to fix this?

[bartonjs]

From the exception message, it seems that whatever provider you're using is rejecting the empty PIN instead of clearing out the PIN-captured state... which seems like a reasonable thing for it to do.

Knowing what you can do instead would depend on what provider you're using, and there may not even be an option.

This doesn't currently look actionable to me.

[RufusJWB]

Thank you for your prompt reply, @bartonjs . Interestingly, it throws an exception, but seems to work anyhow. If I catch the exception and continue, the pin is not cached. --> I'll close this ticket.