使用替代凭据验证 MSMQ 消息？

Question

I've written a C# application that puts an XML-object into an MSMQ queue. The queue requires authentication.

MessageQueue queue = GetQueue();
var message = new Message();
message.Formatter = new CustomXMLFormatter();
message.Body = xml.ToString();
message.Label = "From my application";
message.UseAuthentication = true;
queue.Send(message, MessageQueueTransactionType.Single);

This all works today, but now I need to make a change in the way I authenticate. Currently the messages are authenticated using the user that runs the application. However, I want to use a static AD-user istead. (The reason is that the system retriveing the messages needs that all the messages have been added by a single user account).

Is there a way to change which user performs the authentication?

Answer 1

You could try to use an Impersonator . It works well if your application is running on a machine that is inside the domain. You would have to use something else if the machine is outside the domain, and with no access to the AD Directory.

Here's an example of what the code could look like :

using ( new Impersonator( "myUsername", "myDomainname", "myPassword" ) )
{
   ...
   
   <code that executes under the new context>
  
   ...
}

As a reference, here is the code from the article:

namespace Tools
{
    #region Using directives.
    // ----------------------------------------------------------------------

    using System;
    using System.Security.Principal;
    using System.Runtime.InteropServices;
    using System.ComponentModel;

    // ----------------------------------------------------------------------
    #endregion

    /////////////////////////////////////////////////////////////////////////

    /// <summary>
    /// Impersonation of a user. Allows to execute code under another
    /// user context.
    /// Please note that the account that instantiates the Impersonator class
    /// needs to have the 'Act as part of operating system' privilege set.
    /// </summary>
    /// <remarks>   
    /// This class is based on the information in the Microsoft knowledge base
    /// article http://support.microsoft.com/default.aspx?scid=kb;en-us;Q306158
    /// 
    /// Encapsulate an instance into a using-directive like e.g.:
    /// 
    ///     ...
    ///     using ( new Impersonator( "myUsername", "myDomainname", "myPassword" ) )
    ///     {
    ///         ...
    ///         [code that executes under the new context]
    ///         ...
    ///     }
    ///     ...
    /// 
    /// Please contact the author Uwe Keim (mailto:uwe.keim@zeta-software.de)
    /// for questions regarding this class.
    /// </remarks>
    public class Impersonator :
        IDisposable
    {
        #region Public methods.
        // ------------------------------------------------------------------

        /// <summary>
        /// Constructor. Starts the impersonation with the given credentials.
        /// Please note that the account that instantiates the Impersonator class
        /// needs to have the 'Act as part of operating system' privilege set.
        /// </summary>
        /// <param name="userName">The name of the user to act as.</param>
        /// <param name="domainName">The domain name of the user to act as.</param>
        /// <param name="password">The password of the user to act as.</param>
        public Impersonator(
            string userName,
            string domainName,
            string password )
        {
            ImpersonateValidUser( userName, domainName, password );
        }

        // ------------------------------------------------------------------
        #endregion

        #region IDisposable member.
        // ------------------------------------------------------------------

        public void Dispose()
        {
            UndoImpersonation();
        }

        // ------------------------------------------------------------------
        #endregion

        #region P/Invoke.
        // ------------------------------------------------------------------

        [DllImport("advapi32.dll", SetLastError=true)]
        private static extern int LogonUser(
            string lpszUserName,
            string lpszDomain,
            string lpszPassword,
            int dwLogonType,
            int dwLogonProvider,
            ref IntPtr phToken);
        
        [DllImport("advapi32.dll", CharSet=CharSet.Auto, SetLastError=true)]
        private static extern int DuplicateToken(
            IntPtr hToken,
            int impersonationLevel,
            ref IntPtr hNewToken);

        [DllImport("advapi32.dll", CharSet=CharSet.Auto, SetLastError=true)]
        private static extern bool RevertToSelf();

        [DllImport("kernel32.dll", CharSet=CharSet.Auto)]
        private static extern  bool CloseHandle(
            IntPtr handle);

        private const int LOGON32_LOGON_INTERACTIVE = 2;
        private const int LOGON32_PROVIDER_DEFAULT = 0;

        // ------------------------------------------------------------------
        #endregion

        #region Private member.
        // ------------------------------------------------------------------

        /// <summary>
        /// Does the actual impersonation.
        /// </summary>
        /// <param name="userName">The name of the user to act as.</param>
        /// <param name="domainName">The domain name of the user to act as.</param>
        /// <param name="password">The password of the user to act as.</param>
        private void ImpersonateValidUser(
            string userName, 
            string domain, 
            string password )
        {
            WindowsIdentity tempWindowsIdentity = null;
            IntPtr token = IntPtr.Zero;
            IntPtr tokenDuplicate = IntPtr.Zero;

            try
            {
                if ( RevertToSelf() )
                {
                    if ( LogonUser(
                        userName, 
                        domain, 
                        password, 
                        LOGON32_LOGON_INTERACTIVE,
                        LOGON32_PROVIDER_DEFAULT, 
                        ref token ) != 0 )
                    {
                        if ( DuplicateToken( token, 2, ref tokenDuplicate ) != 0 )
                        {
                            tempWindowsIdentity = new WindowsIdentity( tokenDuplicate );
                            impersonationContext = tempWindowsIdentity.Impersonate();
                        }
                        else
                        {
                            throw new Win32Exception( Marshal.GetLastWin32Error() );
                        }
                    }
                    else
                    {
                        throw new Win32Exception( Marshal.GetLastWin32Error() );
                    }
                }
                else
                {
                    throw new Win32Exception( Marshal.GetLastWin32Error() );
                }
            }
            finally
            {
                if ( token!= IntPtr.Zero )
                {
                    CloseHandle( token );
                }
                if ( tokenDuplicate!=IntPtr.Zero )
                {
                    CloseHandle( tokenDuplicate );
                }
            }
        }

        /// <summary>
        /// Reverts the impersonation.
        /// </summary>
        private void UndoImpersonation()
        {
            if ( impersonationContext!=null )
            {
                impersonationContext.Undo();
            }   
        }

        private WindowsImpersonationContext impersonationContext = null;

        // ------------------------------------------------------------------
        #endregion
    }

    /////////////////////////////////////////////////////////////////////////
}