diff -Nur HttpServer-/HttpClientContext.cs HttpServer/HttpClientContext.cs
--- HttpServer-/HttpClientContext.cs	2014-03-06 16:53:10.802499259 +0900
+++ HttpServer/HttpClientContext.cs	2014-03-07 13:33:26.265146166 +0900
@@ -6,6 +6,10 @@
 using HttpServer.Exceptions;
 using HttpServer.Parser;
 
+// by Fumi.Iseki
+using System.Net.Security;
+using System.Security.Cryptography.X509Certificates;
+
 namespace HttpServer
 {
     /// <summary>
@@ -92,6 +96,18 @@
             _sock = sock;
             _buffer = new byte[bufferSize];
 
+            // by Fumi.Iseki
+            SSLCommonName = "";
+            if (secured)
+            {
+                SslStream _ssl = (SslStream)_stream;
+                X509Certificate _cert1 = _ssl.RemoteCertificate;
+                if (_cert1 != null)
+                {
+                    X509Certificate2 _cert2 = new X509Certificate2(_cert1);
+                    if (_cert2 != null) SSLCommonName = _cert2.GetNameInfo(X509NameType.SimpleName, false);
+                }
+            }
         }
 
         public bool EndWhenDone
@@ -215,6 +231,11 @@
         /// </summary>
         public bool IsSecured { get; internal set; }
 
+        //
+        //
+        // by Fumi.Iseki
+        public string SSLCommonName { get; internal set; }
+
         /// <summary>
         /// Specify which logger to use.
         /// </summary>
diff -Nur HttpServer-/HttpContextFactory.cs HttpServer/HttpContextFactory.cs
--- HttpServer-/HttpContextFactory.cs	2014-03-06 16:53:10.802499259 +0900
+++ HttpServer/HttpContextFactory.cs	2014-03-07 13:39:25.522879915 +0900
@@ -20,6 +20,10 @@
         private readonly ILogWriter _logWriter;
         private readonly ContextTimeoutManager _contextTimeoutManager;
 
+        // by Fumi.Iseki
+        public  static RemoteCertificateValidationCallback ClientCertificateValidationCallback = null;
+        private RemoteCertificateValidationCallback _clientCallback = null;
+
         /// <summary>
         /// Initializes a new instance of the <see cref="HttpContextFactory"/> class.
         /// </summary>
@@ -32,6 +36,13 @@
             _bufferSize = bufferSize;
             _factory = factory;
             _contextTimeoutManager = new ContextTimeoutManager(ContextTimeoutManager.MonitorType.Thread);
+
+            // by Fumi.Iseki
+            if (ClientCertificateValidationCallback != null)
+            {
+                _clientCallback = ClientCertificateValidationCallback;
+                ClientCertificateValidationCallback = null;
+            }
         }
 
         ///<summary>
@@ -132,11 +143,25 @@
 			var networkStream = new ReusableSocketNetworkStream(socket, true);
             var remoteEndPoint = (IPEndPoint) socket.RemoteEndPoint;
 
-            var sslStream = new SslStream(networkStream, false);
+            // by Fumi.Iseki
+            //var sslStream = new SslStream(networkStream, false);
+            SslStream sslStream = null;
             try
             {
                 //TODO: this may fail
-                sslStream.AuthenticateAsServer(certificate, false, protocol, false);
+                // by Fumi.Iseki
+                //sslStream.AuthenticateAsServer(certificate, false, protocol, false);
+                if (_clientCallback == null)
+                {
+                    sslStream = new SslStream(networkStream, false);
+                    sslStream.AuthenticateAsServer(certificate, false, protocol, false);
+                }
+                else
+                {
+                    sslStream = new SslStream(networkStream, false, new RemoteCertificateValidationCallback(_clientCallback));
+                    sslStream.AuthenticateAsServer(certificate, true, protocol, false);
+                }
+
                 return CreateContext(true, remoteEndPoint, sslStream, socket);
             }
             catch (IOException err)
diff -Nur HttpServer-/IHttpClientContext.cs HttpServer/IHttpClientContext.cs
--- HttpServer-/IHttpClientContext.cs	2014-03-06 16:53:10.805499220 +0900
+++ HttpServer/IHttpClientContext.cs	2014-03-07 13:33:38.190006080 +0900
@@ -9,6 +9,11 @@
     /// </summary>
     public interface IHttpClientContext
     {
+        //
+        //
+        // by Fumi.Iseki
+        string SSLCommonName { get; }
+
         /// <summary>
         /// Using SSL or other encryption method.
         /// </summary>