Merge pull request #12 from antiduh/pr/11

Pr/11 Integrate @SteveSyfuhs Thread.CurrentPrinciple changes

NSspi/Contexts/ImpersonationHandle.cs

@@ -1,4 +1,6 @@
 using System;
+using System.Security.Principal;
+using System.Threading;
 
 namespace NSspi.Contexts
 {

NSspi/Contexts/ServerContext.cs

@@ -1,5 +1,7 @@
 using System;
 using System.Runtime.CompilerServices;
+using System.Security.Principal;
+using System.Threading;
 using NSspi.Buffers;
 using NSspi.Credentials;
 
@@ -14,19 +16,25 @@ namespace NSspi.Contexts
         private ContextAttrib finalAttribs;
 
         private bool impersonating;
+        private bool impersonationSetsThreadPrinciple;
 
         /// <summary>
-        /// Performs basic initialization of a new instance of the ServerContext class. The ServerContext
-        /// is not ready for message manipulation until a security context has been established with a client.
+        /// Performs basic initialization of a new instance of the ServerContext class. The
+        /// ServerContext is not ready for message manipulation until a security context has been
+        /// established with a client.
         /// </summary>
         /// <param name="cred"></param>
         /// <param name="requestedAttribs"></param>
-        public ServerContext( Credential cred, ContextAttrib requestedAttribs ) : base( cred )
+        /// <param name="impersonationSetsThreadPrinciple">
+        /// If true, the `Thread.CurrentPrinciple` property will be modified by successful impersonation.
+        /// </param>
+        public ServerContext( Credential cred, ContextAttrib requestedAttribs, bool impersonationSetsThreadPrinciple = false ) : base( cred )
         {
             this.requestedAttribs = requestedAttribs;
             this.finalAttribs = ContextAttrib.Zero;
 
             this.impersonating = false;
+            this.impersonationSetsThreadPrinciple = impersonationSetsThreadPrinciple;
 
             this.SupportsImpersonate = this.Credential.PackageInfo.Capabilities.HasFlag( SecPkgCapability.Impersonation );
         }
@@ -220,7 +228,7 @@ namespace NSspi.Contexts
 
                     this.ContextHandle.DangerousRelease();
 
-                    this.impersonating = true;
+                    this.impersonating = status == SecurityStatus.OK;
                 }
             }
 
@@ -237,6 +245,11 @@ namespace NSspi.Contexts
                 throw new SSPIException( "Failed to impersonate the client", status );
             }
 
+            if( this.impersonating && this.impersonationSetsThreadPrinciple )
+            {
+                SetThreadPrinciple();
+            }
+
             return handle;
         }
 
@@ -299,5 +312,15 @@ 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/Credentials/AuthData.cs

@@ -50,6 +50,6 @@ namespace NSspi.Credentials
     {
         Ansi = 1,
 
-        Unicode = 1
+        Unicode = 2
     }
 }