Removed the binaries link.

NSspi.sln

@@ -1,7 +1,7 @@
 
 Microsoft Visual Studio Solution File, Format Version 12.00
-# Visual Studio 14
+# Visual Studio 15
-VisualStudioVersion = 14.0.25420.1
+VisualStudioVersion = 16.0.28527.54
 MinimumVisualStudioVersion = 10.0.40219.1
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "TestClient", "TestClient\TestClient.csproj", "{E93FBF1A-5198-44D6-BDF0-880D17F2B81A}"
 EndProject

NSspi/Contexts/Context.cs

@@ -1,6 +1,7 @@
 using System;
 using System.Runtime.CompilerServices;
 using System.Runtime.InteropServices;
+using System.Security.Principal;
 using NSspi.Buffers;
 using NSspi.Credentials;
 
@@ -117,6 +118,105 @@ namespace NSspi.Contexts
             this.Disposed = true;
         }
 
+        /// <summary>
+        /// Returns the identity of the remote entity.
+        /// </summary>
+        /// <returns></returns>
+        public IIdentity GetRemoteIdentity()
+        {
+            IIdentity result = null;
+
+            using( var tokenHandle = GetContextToken() )
+            {
+                bool gotRef = false;
+
+                RuntimeHelpers.PrepareConstrainedRegions();
+                try
+                {
+                    tokenHandle.DangerousAddRef( ref gotRef );
+                }
+                catch( Exception )
+                {
+                    if( gotRef )
+                    {
+                        tokenHandle.DangerousRelease();
+                        gotRef = false;
+                    }
+
+                    throw;
+                }
+                finally
+                {
+                    try
+                    {
+                        result = new WindowsIdentity(
+                            tokenHandle.DangerousGetHandle(),
+                            this.Credential.SecurityPackage
+                        );
+                    }
+                    finally
+                    {
+                        // Make sure we release the handle, even if the allocation for
+                        // WindowsIdentity fails.
+                        tokenHandle.DangerousRelease();
+                    }
+                }
+            }
+
+            return result;
+        }
+
+        private SafeTokenHandle GetContextToken()
+        {
+            bool gotRef = false;
+            SecurityStatus status = SecurityStatus.InternalError;
+            SafeTokenHandle token;
+
+            RuntimeHelpers.PrepareConstrainedRegions();
+            try
+            {
+                this.ContextHandle.DangerousAddRef( ref gotRef );
+            }
+            catch( Exception )
+            {
+                if( gotRef )
+                {
+                    this.ContextHandle.DangerousRelease();
+                    gotRef = false;
+                }
+
+                throw;
+            }
+            finally
+            {
+                if( gotRef )
+                {
+                    try
+                    {
+                        status = ContextNativeMethods.QuerySecurityContextToken(
+                            ref this.ContextHandle.rawHandle,
+                            out token
+                        );
+                    }
+                    finally
+                    {
+                        this.ContextHandle.DangerousRelease();
+                    }
+                }
+                else
+                {
+                    token = null;
+                }
+            }
+
+            if( status != SecurityStatus.OK )
+            {
+                throw new SSPIException( "Failed to query context token.", status );
+            }
+
+            return token;
+        }
+
         /// <summary>
         /// Encrypts the byte array using the context's session key.
         /// </summary>

NSspi/Contexts/ContextNativeMethods.cs

@@ -174,6 +174,10 @@ namespace NSspi.Contexts
         [DllImport( "Secur32.dll", EntryPoint = "RevertSecurityContext", CharSet = CharSet.Unicode )]
         internal static extern SecurityStatus RevertSecurityContext( ref RawSspiHandle contextHandle );
 
+        [ReliabilityContract( Consistency.WillNotCorruptState, Cer.Success )]
+        [DllImport( "Secur32.dll", EntryPoint = "QuerySecurityContextToken", SetLastError = true )]
+        internal static extern SecurityStatus QuerySecurityContextToken( ref RawSspiHandle contextHandle, [Out] out SafeTokenHandle handle );
+
         [StructLayout( LayoutKind.Sequential )]
         private class KeyStruct
         {

NSspi/Contexts/SafeTokenHandle.cs

@@ -0,0 +1,27 @@
+using System;
+using System.Runtime.InteropServices;
+
+namespace NSspi.Contexts
+{
+    public class SafeTokenHandle : SafeHandle
+    {
+        public SafeTokenHandle() : base( IntPtr.Zero, true )
+        {
+        }
+
+        public override bool IsInvalid
+        {
+            get
+            {
+                return handle == IntPtr.Zero || handle == new IntPtr( -1 );
+            }
+        }
+
+        protected override bool ReleaseHandle()
+        {
+            NativeMethods.CloseHandle( this.handle );
+
+            return true;
+        }
+    }
+}

NSspi/Contexts/ServerContext.cs

@@ -246,7 +246,7 @@ namespace NSspi.Contexts
 
             if( this.impersonating && this.impersonationSetsThreadPrinciple )
             {
-                SetThreadPrinciple();
+                Thread.CurrentPrincipal = new WindowsPrincipal( (WindowsIdentity)GetRemoteIdentity() );
             }
 
             return handle;
@@ -315,15 +315,5 @@ namespace NSspi.Contexts
 
             base.Dispose( disposing );
         }
-
-        /// <summary>
-        /// Set the current thread security context to the impersonated identity.
-        /// </summary>
-        private void SetThreadPrinciple()
-        {
-            Thread.CurrentPrincipal = new WindowsPrincipal(
-                WindowsIdentity.GetCurrent( TokenAccessLevels.AllAccess ) 
-            );
-        }
     }
 }

NSspi/NSspi.csproj

@@ -5,21 +5,27 @@
     <AssemblyName>NSspi</AssemblyName>
     <GeneratePackageOnBuild>true</GeneratePackageOnBuild>
     <Authors>Kevin Thompson</Authors>
-    <PackageReleaseNotes>Adds multi-targetting to support .Net Standard 2.0.</PackageReleaseNotes>
+    <PackageReleaseNotes>Adds support for accessing the remote identity.</PackageReleaseNotes>
     <PackageProjectUrl>https://github.com/antiduh/nsspi</PackageProjectUrl>
-    <Version>0.3.0.0</Version>
+    <Version>0.3.1.0</Version>
     <SignAssembly>true</SignAssembly>
     <DelaySign>false</DelaySign>
     <AssemblyOriginatorKeyFile>nsspi key.snk</AssemblyOriginatorKeyFile>
+    <PackageLicenseFile>License.txt</PackageLicenseFile>
   </PropertyGroup>
-  <PropertyGroup Condition="'$(Configuration)|$(TargetFramework)|$(Platform)'=='Debug|netstandard2.0|AnyCPU'">
+  
-    <DocumentationFile>NSspi.xml</DocumentationFile>
+  <PropertyGroup>
-  </PropertyGroup>
+    <GenerateDocumentationFile>true</GenerateDocumentationFile>
-  <PropertyGroup Condition="'$(Configuration)|$(TargetFramework)|$(Platform)'=='Release|netstandard2.0|AnyCPU'">
-    <DocumentationFile>NSspi.xml</DocumentationFile>
   </PropertyGroup>
 
   <ItemGroup Condition=" '$(TargetFramework)' == 'netstandard2.0' ">
     <PackageReference Include="System.Security.Principal.Windows" Version="4.5.1" />
   </ItemGroup>
+
+  <ItemGroup>
+    <None Include="..\License.txt">
+      <Pack>True</Pack>
+      <PackagePath></PackagePath>
+    </None>
+  </ItemGroup>
 </Project>

NSspi/NativeMethods.cs

@@ -17,5 +17,9 @@ namespace NSspi
         [ReliabilityContract( Consistency.WillNotCorruptState, Cer.Success )]
         [DllImport( "Secur32.dll", EntryPoint = "EnumerateSecurityPackages", CharSet = CharSet.Unicode )]
         internal static extern SecurityStatus EnumerateSecurityPackages( ref int numPackages, ref IntPtr pkgInfoArry );
+
+        [DllImport( "Kernel32.dll", EntryPoint = "CloseHandle", SetLastError = true )]
+        [ReliabilityContract( Consistency.WillNotCorruptState, Cer.Success )]
+        internal static extern bool CloseHandle( IntPtr handle );
     }
 }

TestServer/ServerForm.Designer.cs

@@ -170,7 +170,8 @@
             // 
             // impersonateButton
             // 
-            this.impersonateButton.Location = new System.Drawing.Point(262, 350);
+            this.impersonateButton.Anchor = ((System.Windows.Forms.AnchorStyles)((System.Windows.Forms.AnchorStyles.Bottom | System.Windows.Forms.AnchorStyles.Left)));
+            this.impersonateButton.Location = new System.Drawing.Point(262, 356);
             this.impersonateButton.Name = "impersonateButton";
             this.impersonateButton.Size = new System.Drawing.Size(116, 23);
             this.impersonateButton.TabIndex = 4;

TestServer/ServerForm.cs

@@ -1,14 +1,16 @@
 using System;
+using System.IO;
+using System.Security.Principal;
 using System.Text;
 using System.Windows.Forms;
+using NSspi;
+using NSspi.Contexts;
+using NSspi.Credentials;
 using TestProtocol;
 
 namespace TestServer
 {
-    using System.IO;
+
-    using NSspi;
-    using NSspi.Contexts;
-    using NSspi.Credentials;
     using Message = TestProtocol.Message;
 
     public partial class ServerForm : Form
@@ -38,7 +40,8 @@ namespace TestServer
                 ContextAttrib.SequenceDetect |
                 ContextAttrib.MutualAuth |
                 ContextAttrib.Delegate |
-                ContextAttrib.Confidentiality
+                ContextAttrib.Confidentiality,
+                true
             );
 
             this.server = new CustomServer();
@@ -123,7 +126,11 @@ namespace TestServer
             {
                 MessageBox.Show( "Starting impersonation: " + Environment.UserName );
 
-                FileStream stream = File.Create( Environment.GetFolderPath( Environment.SpecialFolder.DesktopDirectory ) + @"\test.txt" );
+                var directory = Environment.GetFolderPath( Environment.SpecialFolder.DesktopDirectory );
+
+                Directory.CreateDirectory( directory );
+
+                FileStream stream = File.Create( directory + @"\test.txt" );
                 StreamWriter writer = new StreamWriter( stream, Encoding.UTF8 );
 
                 writer.WriteLine( "Hello world." );
@@ -164,6 +171,32 @@ namespace TestServer
             }
         }
 
+        private void InitComplete()
+        {
+            UpdateButtons();
+            this.clientUsernameTextBox.Text = serverContext.ContextUserName;
+
+            var builder = new StringBuilder();
+            var remoteId = this.serverContext.GetRemoteIdentity();
+
+            builder.AppendLine( "Client identity information:" );
+            builder.AppendLine( " - Name: " + remoteId.Name );
+
+            var windowsId = remoteId as WindowsIdentity;
+
+            if( windowsId != null )
+            {
+                builder.AppendLine( " - User SID: " + windowsId.User.Value );
+
+                foreach( var claim in windowsId.Claims )
+                {
+                    builder.AppendLine( " - " + claim.ToString() );
+                }
+            }
+
+            this.receivedTextbox.AppendText( builder.ToString() );
+        }
+
         private void server_Disconnected()
         {
             this.running = true;
@@ -209,11 +242,7 @@ namespace TestServer
                         this.initializing = false;
                         this.connected = true;
 
-                        this.Invoke( (Action)delegate ()
+                        this.Invoke( (Action)InitComplete );
-                        {
-                            UpdateButtons();
-                            this.clientUsernameTextBox.Text = serverContext.ContextUserName;
-                        } );
                     }
                 }
                 else

readme.md

@@ -1,11 +1,10 @@
 ## Downloads ##
 
-The latest release of NSspi is v0.2.1. 
+The latest release of NSspi is v0.3.1, released 5-Aug-2019. 
 
-Version 0.2.1 is a minor bugfix release that improves impersonation.
+Version 0.3.1 adds support to obtain an IIdentity/WindowsPrinciple representing the remote connection. This is useful for servers that wish to query the properties on the principle, such as claims.
 
-* [Source](https://github.com/antiduh/nsspi/archive/0.2.1.zip)
+* [Source](https://github.com/antiduh/nsspi/archive/0.3.1.zip)
-* [Binaries](https://github.com/antiduh/nsspi/releases/download/0.2.1/nsspi-0.2.1-bin.zip)
 * [Nuget package](https://www.nuget.org/packages/NSspi)
 
 You can also browse the list of [releases](https://github.com/antiduh/nsspi/releases).