part #2

src/__Libraries/StellaOps.Cryptography.Kms/AwsKmsFacade.Metadata.cs

@@ -0,0 +1,44 @@
+using Amazon.KeyManagementService.Model;
+using System;
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace StellaOps.Cryptography.Kms;
+
+internal sealed partial class AwsKmsFacade
+{
+    public async Task<AwsKeyMetadata> GetMetadataAsync(string keyId, CancellationToken cancellationToken)
+    {
+        ArgumentException.ThrowIfNullOrWhiteSpace(keyId);
+
+        var response = await _client.DescribeKeyAsync(new DescribeKeyRequest
+        {
+            KeyId = keyId,
+        }, cancellationToken).ConfigureAwait(false);
+
+        var metadata = response.KeyMetadata ?? throw new InvalidOperationException($"Key '{keyId}' was not found.");
+        var createdAt = metadata.CreationDate?.ToUniversalTime() ?? _timeProvider.GetUtcNow();
+
+        return new AwsKeyMetadata(
+            metadata.KeyId ?? keyId,
+            metadata.Arn ?? metadata.KeyId ?? keyId,
+            createdAt,
+            MapStatus(metadata.KeyState));
+    }
+
+    public async Task<AwsPublicKeyMaterial> GetPublicKeyAsync(string keyResource, CancellationToken cancellationToken)
+    {
+        ArgumentException.ThrowIfNullOrWhiteSpace(keyResource);
+
+        var response = await _client.GetPublicKeyAsync(new GetPublicKeyRequest
+        {
+            KeyId = keyResource,
+        }, cancellationToken).ConfigureAwait(false);
+
+        var keyId = response.KeyId ?? keyResource;
+        var versionId = response.KeyId ?? keyResource;
+        var curve = ResolveCurve(response);
+
+        return new AwsPublicKeyMaterial(keyId, versionId, curve, response.PublicKey.ToArray());
+    }
+}