part #2

src/__Libraries/StellaOps.Cryptography.Kms/Pkcs11Facade.Session.cs

@@ -0,0 +1,77 @@
+using Net.Pkcs11Interop.Common;
+using Net.Pkcs11Interop.HighLevelAPI;
+using System;
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace StellaOps.Cryptography.Kms;
+
+internal sealed partial class Pkcs11InteropFacade
+{
+    private async Task<SessionContext> OpenSessionAsync(CancellationToken cancellationToken)
+    {
+        cancellationToken.ThrowIfCancellationRequested();
+        var session = _slot.OpenSession(SessionType.ReadOnly);
+
+        var loggedIn = false;
+
+        try
+        {
+            if (!string.IsNullOrWhiteSpace(_options.UserPin))
+            {
+                session.Login(CKU.CKU_USER, _options.UserPin);
+                loggedIn = true;
+            }
+
+            return new SessionContext(session, loggedIn);
+        }
+        catch
+        {
+            if (loggedIn)
+            {
+                try { session.Logout(); } catch { }
+            }
+
+            session.Dispose();
+            throw;
+        }
+    }
+
+    private sealed class SessionContext : IDisposable
+    {
+        private readonly ISession _session;
+        private readonly bool _logoutOnDispose;
+        private bool _disposed;
+
+        public SessionContext(ISession session, bool logoutOnDispose)
+        {
+            _session = session ?? throw new ArgumentNullException(nameof(session));
+            _logoutOnDispose = logoutOnDispose;
+        }
+
+        public ISession Session => _session;
+
+        public void Dispose()
+        {
+            if (_disposed)
+            {
+                return;
+            }
+
+            if (_logoutOnDispose)
+            {
+                try
+                {
+                    _session.Logout();
+                }
+                catch
+                {
+                    // ignore logout failures
+                }
+            }
+
+            _session.Dispose();
+            _disposed = true;
+        }
+    }
+}