Update comments

src/libraries/System.Net.Security/src/System/Net/Security/NegotiateAuthentication.cs

@@ -7,6 +7,10 @@
 
 namespace System.Net.Security
 {
+    /// <summary>
+    /// Represents a stateful authentication exchange that uses the Negotiate, NTLM or Kerberos security protocols
+    /// to authenticate the client or server, in client-server communication.
+    /// </summary>
     public sealed class NegotiateAuthentication : IDisposable
     {
         private NTAuthentication _ntAuthentication;

src/libraries/System.Net.Security/src/System/Net/Security/NegotiateAuthenticationStatusCode.cs

@@ -11,7 +11,7 @@ public enum NegotiateAuthenticationStatusCode
         GenericFailure, // GSS_S_FAILURE/GSS_S_NO_CONTEXT
         BadBinding, // GSS_S_BAD_BINDINGS
         Unsupported, // GSS_S_BAD_MECH (Unsupported mechanism)
-        MessageAltered, // GSS_S_BAD_SIG = GSS_S_BAD_MIC
+        MessageAltered, // GSS_S_BAD_SIG/GSS_S_BAD_MIC
         ContextExpired, // GSS_S_CONTEXT_EXPIRED
         CredentialsExpired, // GSS_S_CREDENTIALS_EXPIRED
         InvalidCredentials, // GSS_S_DEFECTIVE_CREDENTIAL