part #2

src/__Libraries/StellaOps.Cryptography.Kms/MissingFido2Authenticator.cs

@@ -0,0 +1,11 @@
+using System;
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace StellaOps.Cryptography.Kms;
+
+internal sealed class MissingFido2Authenticator : IFido2Authenticator
+{
+    public Task<byte[]> SignAsync(string credentialId, ReadOnlyMemory<byte> digest, CancellationToken cancellationToken = default)
+        => throw new InvalidOperationException("IFido2Authenticator must be registered to use FIDO2 KMS.");
+}