How to set CurrentPrincipal from non-web AD login?

Question

This seems like pretty basic functionality, but my initial searches didn't yield anything...

I want to do a login from a console app using ActiveDirectory, and set the Thread.CurrentPrincipal if the login is successful. All the solutions I've found online assume you want to use HTTP authentication. How do I do this from a non-HTTP context?

Answer 1

The Simplest way to do it is make some P/Invoke calls to get the logon token then pass that in to the WindowsIdentity constructor (which you pass to the WindowsPrincipal constructor )

This question helped me out in the past which will get you 90% of the way there, unless you need to do Impersonation, then it gets you 100% of the way there :)

using System;
using System.Runtime.InteropServices;

/// <summary>
/// Implements P/Invoke Interop calls to the operating system.
/// </summary>
internal static class NativeMethods
{
    /// <summary>
    /// The type of logon operation to perform.
    /// </summary>
    internal enum LogonType : int
    {
        /// <summary>
        /// This logon type is intended for users who will be interactively
        /// using the computer, such as a user being logged on by a
        /// terminal server, remote shell, or similar process.
        /// This logon type has the additional expense of caching logon
        /// information for disconnected operations; therefore, it is
        /// inappropriate for some client/server applications, such as a
        /// mail server.
        /// </summary>
        Interactive = 2,

        /// <summary>
        /// This logon type is intended for high performance servers to
        /// authenticate plaintext passwords.
        /// The LogonUser function does not cache credentials for this
        /// logon type.
        /// </summary>
        Network = 3,

        /// <summary>
        /// This logon type is intended for batch servers, where processes
        /// may be executing on behalf of a user without their direct
        /// intervention.  This type is also for higher performance servers
        /// that process many plaintext authentication attempts at a time,
        /// such as mail or Web servers.
        /// The LogonUser function does not cache credentials for this
        /// logon type.
        /// </summary>
        Batch = 4,

        /// <summary>
        /// Indicates a service-type logon.  The account provided must have
        /// the service privilege enabled.
        /// </summary>
        Service = 5,

        /// <summary>
        /// This logon type is for GINA DLLs that log on users who will be
        /// interactively using the computer.
        /// This logon type can generate a unique audit record that shows
        /// when the workstation was unlocked.
        /// </summary>
        Unlock = 7,

        /// <summary>
        /// This logon type preserves the name and password in the
        /// authentication package, which allows the server to make
        /// connections to other network servers while impersonating the
        /// client.  A server can accept plaintext credentials from a
        /// client, call LogonUser, verify that the user can access the
        /// system across the network, and still communicate with other
        /// servers.
        /// NOTE: Windows NT:  This value is not supported.
        /// </summary>
        NetworkCleartext = 8,

        /// <summary>
        /// This logon type allows the caller to clone its current token
        /// and specify new credentials for outbound connections.  The new
        /// logon session has the same local identifier but uses different
        /// credentials for other network connections.
        /// NOTE: This logon type is supported only by the
        /// LOGON32_PROVIDER_WINNT50 logon provider.
        /// NOTE: Windows NT:  This value is not supported.
        /// </summary>
        NewCredentials = 9
    }

    /// <summary>
    /// Specifies the logon provider.
    /// </summary>
    internal enum LogonProvider : int
    {
        /// <summary>
        /// Use the standard logon provider for the system.
        /// The default security provider is negotiate, unless you pass
        /// NULL for the domain name and the user name is not in UPN format.
        /// In this case, the default provider is NTLM.
        /// NOTE: Windows 2000/NT:   The default security provider is NTLM.
        /// </summary>
        Default = 0,

        /// <summary>
        /// Use this provider if you'll be authenticating against a Windows
        /// NT 3.51 domain controller (uses the NT 3.51 logon provider).
        /// </summary>
        WinNT35 = 1,

        /// <summary>
        /// Use the NTLM logon provider.
        /// </summary>
        WinNT40 = 2,

        /// <summary>
        /// Use the negotiate logon provider.
        /// </summary>
        WinNT50 = 3
    }

    /// <summary>
    /// The type of logon operation to perform.
    /// </summary>
    internal enum SecurityImpersonationLevel : int
    {
        /// <summary>
        /// The server process cannot obtain identification information
        /// about the client, and it cannot impersonate the client.  It is
        /// defined with no value given, and thus, by ANSI C rules,
        /// defaults to a value of zero.
        /// </summary>
        Anonymous = 0,

        /// <summary>
        /// The server process can obtain information about the client,
        /// such as security identifiers and privileges, but it cannot
        /// impersonate the client.  This is useful for servers that export
        /// their own objects, for example, database products that export
        /// tables and views.  Using the retrieved client-security
        /// information, the server can make access-validation decisions
        /// without being able to use other services that are using the
        /// client's security context.
        /// </summary>
        Identification = 1,

        /// <summary>
        /// The server process can impersonate the client's security
        /// context on its local system.  The server cannot impersonate the
        /// client on remote systems.
        /// </summary>
        Impersonation = 2,

        /// <summary>
        /// The server process can impersonate the client's security
        /// context on remote systems.
        /// NOTE: Windows NT:  This impersonation level is not supported.
        /// </summary>
        Delegation = 3
    }

    /// <summary>
    /// Logs on the user.
    /// </summary>
    /// <param name="userName">Name of the user.</param>
    /// <param name="domain">The domain.</param>
    /// <param name="password">The password.</param>
    /// <param name="logonType">Type of the logon.</param>
    /// <param name="logonProvider">The logon provider.</param>
    /// <param name="token">The token.</param>
    /// <returns>True if the function succeeds, false if the function fails.
    /// To get extended error information, call GetLastError.</returns>
    [DllImport("advapi32.dll", CharSet = CharSet.Unicode, SetLastError = true)]
    [return: MarshalAs(UnmanagedType.Bool)]
    internal static extern bool LogonUser(
        string userName,
        string domain,
        string password,
        LogonType logonType,
        LogonProvider logonProvider,
        out IntPtr token);

    /// <summary>
    /// Duplicates the token.
    /// </summary>
    /// <param name="existingTokenHandle">The existing token
    /// handle.</param>
    /// <param name="securityImpersonationLevel">The security impersonation
    /// level.</param>
    /// <param name="duplicateTokenHandle">The duplicate token
    /// handle.</param>
    /// <returns>True if the function succeeds, false if the function fails.
    /// To get extended error information, call GetLastError.</returns>
    [DllImport("advapi32.dll", CharSet = CharSet.Unicode, SetLastError = true)]
    [return: MarshalAs(UnmanagedType.Bool)]
    internal static extern bool DuplicateToken(
        IntPtr existingTokenHandle,
        SecurityImpersonationLevel securityImpersonationLevel,
        out IntPtr duplicateTokenHandle);

    /// <summary>
    /// Closes the handle.
    /// </summary>
    /// <param name="handle">The handle.</param>
    /// <returns>True if the function succeeds, false if the function fails.
    /// To get extended error information, call GetLastError.</returns>
    [DllImport("kernel32.dll", CharSet = CharSet.Unicode, SetLastError = true)]
    [return: MarshalAs(UnmanagedType.Bool)]
    internal static extern bool CloseHandle(IntPtr handle);
}

followed by

    IntPtr token;

    if (!NativeMethods.LogonUser(
        this.userName,
        this.domain,
        this.password,
        NativeMethods.LogonType.NewCredentials,
        NativeMethods.LogonProvider.Default,
        out token))
    {
        throw new Win32Exception();
    }

    try
    {
        IntPtr tokenDuplicate;

        if (!NativeMethods.DuplicateToken(
            token,
            NativeMethods.SecurityImpersonationLevel.Impersonation,
            out tokenDuplicate))
        {
            throw new Win32Exception();
        }

        try
        {
            using (WindowsImpersonationContext impersonationContext =
                new WindowsIdentity(tokenDuplicate).Impersonate())
            {
                // Do stuff as a impersonated context here.

                impersonationContext.Undo();
                return;
            }
        }
        finally
        {
            if (tokenDuplicate != IntPtr.Zero)
            {
                if (!NativeMethods.CloseHandle(tokenDuplicate))
                {
                    // Uncomment if you need to know this case.
                    ////throw new Win32Exception();
                }
            }
        }
    }
    finally
    {
        if (token != IntPtr.Zero)
        {
            if (!NativeMethods.CloseHandle(token))
            {
                // Uncomment if you need to know this case.
                ////throw new Win32Exception();
            }
        }
    }

Answer 2

This may not be as "proper" as @ScottChamberlain's answer, but I found it worked for me.

First, I did the authentication using forms authentication, as described here . The code there is in VB; here's a C# implementation below:

var domainAndUsername = domain + "\\" + userName;
var entry = new DirectoryEntry(myADServicePath, domainAndUsername, password);
// Bind to the native AdsObject to force authentication.
var obj = entry.NativeObject;
var search = new DirectorySearcher(entry) { Filter = "(SAMAccountName=" + userName + ")" };
search.PropertiesToLoad.Add("cn");
var result = search.FindOne();
if (null == result)
{
  return null; // or whatever else indicates failed login in your context
}

Then, to set the current principal, I just used a GenericPrincipal :

var identity = new GenericIdentity(userName);
var principal = new GenericPrincipal(identity, myRoles); // I'll leave it to you to work out what roles there are
Thread.CurrentPrincipal = principal;