Added password authentication support.

Added the ability to acquire a valid credential by providing a username/password combination.

NSspi/Credentials/AuthData.cs

@@ -0,0 +1,55 @@
+using System;
+using System.Runtime.InteropServices;
+
+namespace NSspi.Credentials
+{
+    /// <summary>
+    /// Provides authentication data in native method calls.
+    /// </summary>
+    /// <remarks>
+    /// Implements the 'SEC_WINNT_AUTH_IDENTITY' structure. See:
+    ///
+    /// https://msdn.microsoft.com/en-us/library/windows/desktop/aa380131(v=vs.85).aspx
+    /// </remarks>
+    [StructLayout( LayoutKind.Sequential )]
+    internal struct NativeAuthData
+    {
+        public NativeAuthData( string domain, string username, string password, NativeAuthDataFlag flag )
+        {
+            this.Domain = domain;
+            this.DomainLength = domain.Length;
+
+            this.User = username;
+            this.UserLength = username.Length;
+
+            this.Password = password;
+            this.PasswordLength = password.Length;
+
+            this.Flags = flag;
+        }
+
+        [MarshalAs( UnmanagedType.LPWStr )]
+        public string User;
+
+        public int UserLength;
+
+        [MarshalAs( UnmanagedType.LPWStr )]
+        public string Domain;
+
+        public int DomainLength;
+
+        [MarshalAs( UnmanagedType.LPWStr )]
+        public string Password;
+
+        public int PasswordLength;
+
+        public NativeAuthDataFlag Flags;
+    }
+
+    internal enum NativeAuthDataFlag : int
+    {
+        Ansi = 1,
+
+        Unicode = 1
+    }
+}

NSspi/Credentials/CredentialNativeMethods.cs

@@ -20,6 +20,21 @@ namespace NSspi.Credentials
             ref TimeStamp expiry
         );
 
+        [ReliabilityContract( Consistency.WillNotCorruptState, Cer.MayFail )]
+        [DllImport( "Secur32.dll", EntryPoint = "AcquireCredentialsHandle", CharSet = CharSet.Unicode )]
+        internal static extern SecurityStatus AcquireCredentialsHandle_AuthData(
+            string principleName,
+            string packageName,
+            CredentialUse credentialUse,
+            IntPtr loginId,
+            ref NativeAuthData authData,
+            IntPtr getKeyFunc,
+            IntPtr getKeyData,
+            ref RawSspiHandle credentialHandle,
+            ref TimeStamp expiry
+        );
+
+
         [ReliabilityContract( Consistency.WillNotCorruptState, Cer.Success )]
         [DllImport( "Secur32.dll", EntryPoint = "FreeCredentialsHandle", CharSet = CharSet.Unicode )]
         internal static extern SecurityStatus FreeCredentialsHandle(

NSspi/Credentials/PasswordCredential.cs

@@ -0,0 +1,78 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Runtime.CompilerServices;
+using System.Text;
+
+namespace NSspi.Credentials
+{
+    /// <summary>
+    /// Represents credentials acquired by providing a username, password, and domain.
+    /// </summary>
+    public class PasswordCredential : Credential
+    {
+        /// <summary>
+        /// Initializes a new instance of the PasswordCredential class.
+        /// </summary>
+        /// <remarks>
+        /// It is possible to acquire a valid handle to credentials that do not provide a valid
+        /// username-password combination. The username and password are not validation until the
+        /// authentication cycle begins.
+        /// </remarks>
+        /// <param name="domain">The domain to authenticate to.</param>
+        /// <param name="username">The username of the user to authenticate as.</param>
+        /// <param name="password">The user's password.</param>
+        /// <param name="secPackage">The SSPI security package to create credentials for.</param>
+        /// <param name="use">
+        /// Specify inbound when acquiring credentials for a server; outbound for a client.
+        /// </param>
+        public PasswordCredential( string domain, string username, string password, string secPackage, CredentialUse use ) 
+            : base( secPackage )
+        {
+            NativeAuthData authData = new NativeAuthData( domain, username, password, NativeAuthDataFlag.Unicode );
+
+            Init( authData, secPackage, use );
+        }
+
+        private void Init( NativeAuthData authData, string secPackage, CredentialUse use )
+        {
+            string packageName;
+            TimeStamp rawExpiry = new TimeStamp();
+            SecurityStatus status = SecurityStatus.InternalError;
+
+            // -- Package --
+            // Copy off for the call, since this.SecurityPackage is a property.
+            packageName = this.SecurityPackage;
+
+            this.Handle = new SafeCredentialHandle();
+
+
+            // The finally clause is the actual constrained region. The VM pre-allocates any stack space,
+            // performs any allocations it needs to prepare methods for execution, and postpones any
+            // instances of the 'uncatchable' exceptions (ThreadAbort, StackOverflow, OutOfMemory).
+            RuntimeHelpers.PrepareConstrainedRegions();
+            try { }
+            finally
+            {
+                status = CredentialNativeMethods.AcquireCredentialsHandle_AuthData(
+                   null,
+                   packageName,
+                   use,
+                   IntPtr.Zero,
+                   ref authData,
+                   IntPtr.Zero,
+                   IntPtr.Zero,
+                   ref this.Handle.rawHandle,
+                   ref rawExpiry
+               );
+            }
+
+            if( status != SecurityStatus.OK )
+            {
+                throw new SSPIException( "Failed to call AcquireCredentialHandle", status );
+            }
+
+            this.Expiry = rawExpiry.ToDateTime();
+        }
+    }
+}

NSspi/NSspi.csproj

@@ -55,8 +55,10 @@
     <Compile Include="Contexts\ContextQueryAttrib.cs" />
     <Compile Include="Contexts\ImpersonationHandle.cs" />
     <Compile Include="Contexts\SafeContextHandle.cs" />
+    <Compile Include="Credentials\AuthData.cs" />
     <Compile Include="Credentials\ClientCurrentCredential.cs" />
     <Compile Include="Credentials\CurrentCredential.cs" />
+    <Compile Include="Credentials\PasswordCredential.cs" />
     <Compile Include="Credentials\ServerCurrentCredential.cs" />
     <Compile Include="EnumMgr.cs" />
     <Compile Include="SecPkgInfo.cs" />