diff --git a/SMBLibrary/Authentication/GSSAPI/IGSSMechanism.cs b/SMBLibrary/Authentication/GSSAPI/IGSSMechanism.cs
new file mode 100644
index 0000000..d903272
--- /dev/null
+++ b/SMBLibrary/Authentication/GSSAPI/IGSSMechanism.cs
@@ -0,0 +1,35 @@
+/* Copyright (C) 2017 Tal Aloni <tal.aloni.il@gmail.com>. All rights reserved.
+ * 
+ * You can redistribute this program and/or modify it under the terms of
+ * the GNU Lesser Public License as published by the Free Software Foundation,
+ * either version 3 of the License, or (at your option) any later version.
+ */
+using System;
+using System.Collections.Generic;
+
+namespace SMBLibrary.Authentication.GSSAPI
+{
+    public interface IGSSMechanism
+    {
+        /// <summary>
+        /// Equivalent to GSS_Accept_sec_context
+        /// </summary>
+        NTStatus AcceptSecurityContext(ref object context, byte[] inputToken, out byte[] outputToken);
+
+        /// <summary>
+        /// Equivalent to GSS_Delete_sec_context
+        /// Obtains information about a given security context (even an incomplete one)
+        /// </summary>
+        void DeleteSecurityContext(ref object context);
+
+        /// <summary>
+        /// Equivalent to GSS_Inquire_context
+        /// </summary>
+        object GetContextAttribute(object context, GSSAttributeName attributeName);
+
+        byte[] Identifier
+        {
+            get;
+        }
+    }
+}
diff --git a/SMBLibrary/Authentication/NTLM/NTLMAuthenticationProviderBase.cs b/SMBLibrary/Authentication/NTLM/NTLMAuthenticationProviderBase.cs
index b285864..546e2ad 100644
--- a/SMBLibrary/Authentication/NTLM/NTLMAuthenticationProviderBase.cs
+++ b/SMBLibrary/Authentication/NTLM/NTLMAuthenticationProviderBase.cs
@@ -10,8 +10,38 @@ using SMBLibrary.Authentication.GSSAPI;
 
 namespace SMBLibrary.Authentication.NTLM
 {
-    public abstract class NTLMAuthenticationProviderBase
+    public abstract class NTLMAuthenticationProviderBase : IGSSMechanism
     {
+        public static readonly byte[] NTLMSSPIdentifier = new byte[] { 0x2b, 0x06, 0x01, 0x04, 0x01, 0x82, 0x37, 0x02, 0x02, 0x0a };
+
+        public NTStatus AcceptSecurityContext(ref object context, byte[] inputToken, out byte[] outputToken)
+        {
+            outputToken = null;
+            if (!AuthenticationMessageUtils.IsSignatureValid(inputToken))
+            {
+                return NTStatus.SEC_E_INVALID_TOKEN;
+            }
+
+            MessageTypeName messageType = AuthenticationMessageUtils.GetMessageType(inputToken);
+            if (messageType == MessageTypeName.Negotiate)
+            {
+                NegotiateMessage input = new NegotiateMessage(inputToken);
+                ChallengeMessage output;
+                NTStatus status = GetChallengeMessage(out context, input, out output);
+                outputToken = output.GetBytes();
+                return status;
+            }
+            else if (messageType == MessageTypeName.Authenticate)
+            {
+                AuthenticateMessage message = new AuthenticateMessage(inputToken);
+                return Authenticate(context, message);
+            }
+            else
+            {
+                return NTStatus.SEC_E_INVALID_TOKEN;
+            }
+        }
+
         public abstract NTStatus GetChallengeMessage(out object context, NegotiateMessage negotiateMessage, out ChallengeMessage challengeMessage);
 
         public abstract NTStatus Authenticate(object context, AuthenticateMessage authenticateMessage);
@@ -19,5 +49,13 @@ namespace SMBLibrary.Authentication.NTLM
         public abstract void DeleteSecurityContext(ref object context);
 
         public abstract object GetContextAttribute(object context, GSSAttributeName attributeName);
+
+        public byte[] Identifier
+        {
+            get
+            {
+                return NTLMSSPIdentifier;
+            }
+        }
     }
 }
diff --git a/SMBLibrary/SMBLibrary.csproj b/SMBLibrary/SMBLibrary.csproj
index e1e99da..e97f6f0 100644
--- a/SMBLibrary/SMBLibrary.csproj
+++ b/SMBLibrary/SMBLibrary.csproj
@@ -33,6 +33,7 @@
   <ItemGroup>
     <Compile Include="Authentication\GSSAPI\Enums\GSSAttributeName.cs" />
     <Compile Include="Authentication\GSSAPI\GSSAPIHelper.cs" />
+    <Compile Include="Authentication\GSSAPI\IGSSMechanism.cs" />
     <Compile Include="Authentication\GSSAPI\SPNEGO\DerEncodingHelper.cs" />
     <Compile Include="Authentication\GSSAPI\SPNEGO\SimpleProtectedNegotiationToken.cs" />
     <Compile Include="Authentication\GSSAPI\SPNEGO\SimpleProtectedNegotiationTokenInit.cs" />