initial commit

Pulsar.Common/Networking/ISender.cs

@@ -0,0 +1,10 @@
+using Pulsar.Common.Messages.Other;
+
+namespace Pulsar.Common.Networking
+{
+    public interface ISender
+    {
+        void Send<T>(T message) where T : IMessage;
+        void Disconnect();
+    }
+}

Pulsar.Common/Networking/SecureMessageEnvelopeHelper.cs

@@ -0,0 +1,75 @@
+using Pulsar.Common.Cryptography;
+using Pulsar.Common.Messages.Other;
+using System;
+using System.Security.Cryptography.X509Certificates;
+using System.Text;
+
+namespace Pulsar.Common.Networking
+{
+    public static class SecureMessageEnvelopeHelper
+    {
+        public static bool CanUse(X509Certificate2 certificate)
+        {
+            return certificate != null && certificate.RawData != null && certificate.RawData.Length > 0;
+        }
+
+        public static SecureMessageEnvelope Wrap(IMessage message, X509Certificate2 certificate)
+        {
+            if (message == null)
+                throw new ArgumentNullException(nameof(message));
+
+            if (message is SecureMessageEnvelope)
+                throw new InvalidOperationException("Message is already wrapped in a secure envelope.");
+
+            if (!CanUse(certificate))
+                throw new ArgumentException("A valid certificate is required to wrap the message.", nameof(certificate));
+
+            var serialized = PulsarMessagePackSerializer.Serialize(message);
+            var keyMaterial = DeriveKeyMaterial(certificate);
+
+            var cipher = new Aes256(keyMaterial);
+            var payload = cipher.Encrypt(serialized);
+
+            return new SecureMessageEnvelope
+            {
+                Payload = payload
+            };
+        }
+
+        public static IMessage Unwrap(SecureMessageEnvelope envelope, X509Certificate2 certificate)
+        {
+            if (envelope == null)
+                throw new ArgumentNullException(nameof(envelope));
+
+            if (envelope.Payload == null || envelope.Payload.Length == 0)
+                throw new ArgumentException("Envelope payload is empty.", nameof(envelope));
+
+            if (!CanUse(certificate))
+                throw new ArgumentException("A valid certificate is required to unwrap the message.", nameof(certificate));
+
+            var keyMaterial = DeriveKeyMaterial(certificate);
+
+            var cipher = new Aes256(keyMaterial);
+            var decrypted = cipher.Decrypt(envelope.Payload);
+            try
+            {
+                return PulsarMessagePackSerializer.Deserialize(decrypted);
+            }
+            catch (Exception ex)
+            {
+                throw new InvalidOperationException($"Failed to deserialize secure payload (length={decrypted?.Length ?? 0}).", ex);
+            }
+        }
+
+        private static string DeriveKeyMaterial(X509Certificate2 certificate)
+        {
+            var thumbprint = certificate.Thumbprint?.Replace(" ", string.Empty)?.ToUpperInvariant();
+            if (string.IsNullOrEmpty(thumbprint))
+                throw new InvalidOperationException("Certificate thumbprint is unavailable for secure envelope key derivation.");
+
+            var hash = Sha256.ComputeHash(Encoding.UTF8.GetBytes(thumbprint));
+            return Convert.ToBase64String(hash);
+        }
+
+    }
+}