update arguments passed to NTAuthentication constructor

Author: Geoff Kizer

src/System.Net.Http/src/System/Net/Http/SocketsHttpHandler/AuthenticationHelper.NtAuth.cs

@@ -6,6 +6,7 @@
 using System.Net.Http.Headers;
 using System.Threading;
 using System.Threading.Tasks;
+using System.Security.Authentication.ExtendedProtection;
 
 namespace System.Net.Http
 {
@@ -48,8 +49,9 @@ private static async Task<HttpResponseMessage> SendWithNtAuthAsync(HttpRequestMe
                 {
                     string challengeData = challenge.ChallengeData;
 
-                    // TODO: Validate correct arguments to NTAuthentication
-                    NTAuthentication authContext = new NTAuthentication(false, challenge.SchemeName, challenge.Credential, null, ContextFlagsPal.Connection, null);
+                    string spn = "HTTP/" + authUri.IdnHost;
+                    ChannelBinding channelBinding = connection.TransportContext?.GetChannelBinding(ChannelBindingKind.Endpoint);
+                    NTAuthentication authContext = new NTAuthentication(false, challenge.SchemeName, challenge.Credential, spn, ContextFlagsPal.Connection, channelBinding);
                     try
                     {
                         while (true)

src/System.Net.Http/src/System/Net/Http/SocketsHttpHandler/AuthenticationHelper.cs

@@ -12,12 +12,11 @@ internal partial class AuthenticationHelper
     {
         private const string BasicScheme = "Basic";
         private const string DigestScheme = "Digest";
-        private const string NtlmScheme = "ntlm";
-        private const string NegotiateScheme = "negotiate";
+        private const string NtlmScheme = "NTLM";
+        private const string NegotiateScheme = "Negotiate";
 
         private enum AuthenticationType
         {
-            None,
             Basic,
             Digest,
             Ntlm,

src/System.Net.Http/src/System/Net/Http/SocketsHttpHandler/HttpConnection.cs

@@ -152,6 +152,8 @@ public bool CanRetry
 
         public DateTimeOffset CreationTime { get; } = DateTimeOffset.UtcNow;
 
+        public TransportContext TransportContext => _transportContext;
+
         private int ReadBufferSize => _readBuffer.Length;
 
         private ReadOnlyMemory<byte> RemainingBuffer => new ReadOnlyMemory<byte>(_readBuffer, _readOffset, _readLength - _readOffset);