Added support for querying a credential's name.

Credential.cs

@@ -2,6 +2,7 @@
 using System.Collections.Generic;
 using System.DirectoryServices.AccountManagement;
 using System.Linq;
+using System.Runtime.InteropServices;
 using System.Text;
 using System.Threading.Tasks;
 
@@ -101,9 +102,33 @@ namespace NSspi
             }
         }
 
-        public string GetName()
+        public string Name 
         {
-            return null;
+            get
+            {
+                NativeMethods.QueryNameAttribCarrier carrier = new NativeMethods.QueryNameAttribCarrier();
+
+                SecurityStatus status;
+                string name = null;
+
+                status = NativeMethods.QueryCredentialsAttribute_Name(
+                    ref this.credHandle,
+                    CredentialQueryAttrib.Names,
+                    ref carrier
+                );
+
+                if ( status == SecurityStatus.Success )
+                {
+                    name = Marshal.PtrToStringUni( carrier.Name );
+                    NativeMethods.FreeContextBuffer( carrier.Name );
+                }
+                else
+                {
+                    throw new SSPIException( "Failed to query credential name", status );
+                }
+
+                return name;
+            }
         }
 
         public long CredentialHandle

CredentialQueryAttrib.cs

@@ -0,0 +1,23 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace NSspi
+{
+    /*
+     #define SECPKG_CRED_ATTR_NAMES        1
+     #define SECPKG_CRED_ATTR_SSI_PROVIDER 2
+     #define SECPKG_CRED_ATTR_KDC_PROXY_SETTINGS 3
+     #define SECPKG_CRED_ATTR_CERT         4
+     */
+
+    public enum CredentialQueryAttrib : uint
+    {
+        Names = 1,
+        SsiProvider = 2,
+        KdcProxySettings = 3,
+        Cert = 4
+    }
+}

NSspi.csproj

@@ -46,6 +46,7 @@
   <ItemGroup>
     <Compile Include="Credential.cs" />
     <Compile Include="CredentialPackage.cs" />
+    <Compile Include="CredentialQueryAttrib.cs" />
     <Compile Include="CredentialType.cs" />
     <Compile Include="CredentialUse.cs" />
     <Compile Include="NativeMethods.cs" />

NativeMethods.cs

@@ -73,5 +73,55 @@ namespace NSspi
             ref long credentialHandle
         );
 
+        /*
+        SECURITY_STATUS SEC_Entry FreeContextBuffer(
+          _In_  PVOID pvContextBuffer
+        );
+        */
+        [DllImport(
+            "Secur32.dll",
+            EntryPoint = "FreeContextBuffer",
+            CallingConvention = CallingConvention.Winapi,
+            CharSet = CharSet.Unicode,
+            SetLastError = true
+        )]
+        public static extern SecurityStatus FreeContextBuffer( IntPtr buffer );
+
+        
+
+        /*
+        SECURITY_STATUS SEC_Entry QueryCredentialsAttributes(
+          _In_   PCredHandle phCredential,
+          _In_   ULONG ulAttribute,
+          _Out_  PVOID pBuffer
+        );
+        */
+
+        /// <summary>
+        /// The overload of the QueryCredentialsAttribute method that is used for querying the name attribute.
+        /// In this call, it takes a void* to a structure that contains a wide char* pointer.
+        /// </summary>
+        /// <param name="credentialHandle"></param>
+        /// <param name="attributeName"></param>
+        /// <param name="name"></param>
+        /// <returns></returns>
+        [DllImport(
+            "Secur32.dll",
+            EntryPoint = "QueryCredentialsAttributes",
+            CallingConvention = CallingConvention.Winapi,
+            CharSet = CharSet.Unicode,
+            SetLastError = true
+        )]
+        public static extern SecurityStatus QueryCredentialsAttribute_Name(
+            ref long credentialHandle,
+            CredentialQueryAttrib attributeName,
+            ref QueryNameAttribCarrier name
+        );
+
+        [StructLayout( LayoutKind.Sequential )]
+        public struct QueryNameAttribCarrier
+        {
+            public IntPtr Name;
+        }
     }
 }

Program.cs

@@ -10,9 +10,22 @@ namespace NSspi
     {
         public static void Main( string[] args )
         {
-            Credential cred = new Credential( SecurityPackage.Negotiate, CredentialType.Client );
-            cred.Dispose();
+            Credential cred = null;
+            try
+            {
+                cred = new Credential( SecurityPackage.Negotiate, CredentialType.Client );
 
+                string name = cred.GetName();
+                Console.Out.WriteLine( name );
+                Console.Out.Flush();
+            }
+            finally
+            {
+                if ( cred != null )
+                {
+                    cred.Dispose();
+                }
+            }
         }
     }
 }