Using impersonation to launch processes (indirectly) in C#

Question

I am working on an application that uses Selenium to control a browser. Selenium launches the browser when it is initialized, and I therefore never call Process.Start directly on the browser's .exe. I would like Selenium and all of its child processes to run under a different user than my application (since I don't want it to have access to my source). Using the impersonation sample found here, I am trying to wrap the Selenium code with impersonation, but it appears that all child processes get launched with by the user that launched their parent process.

Does anyone know a way to wrap a block of code with user impersonation and have all child processes launch with the impersonated user's permissions? If not, what would be the best tactic to achieve this? Run all of the Selenium logic in another process and somehow pipe commands to it?

Answer 1

try this .

This class give you the ability to lunch process as user,

here I user the Explorer session.

using System.Runtime.InteropServices;
using System;
using System.Diagnostics;


[StructLayout(LayoutKind.Sequential)]
internal struct PROCESS_INFORMATION
{
    public IntPtr hProcess;
    public IntPtr hThread;
    public uint dwProcessId;
    public uint dwThreadId;
 }



 [StructLayout(LayoutKind.Sequential)]
 internal struct SECURITY_ATTRIBUTES
 {
    public uint nLength;
    public IntPtr lpSecurityDescriptor;
    public bool bInheritHandle;
  }


  [StructLayout(LayoutKind.Sequential)]
  public struct STARTUPINFO
  {
      public uint cb;
      public string lpReserved;
      public string lpDesktop;
      public string lpTitle;
      public uint dwX;
      public uint dwY;
      public uint dwXSize;
      public uint dwYSize;
      public uint dwXCountChars;
      public uint dwYCountChars;
      public uint dwFillAttribute;
      public uint dwFlags;
      public short wShowWindow;
      public short cbReserved2;
      public IntPtr lpReserved2;
      public IntPtr hStdInput;
      public IntPtr hStdOutput;
      public IntPtr hStdError;

  }

   internal enum SECURITY_IMPERSONATION_LEVEL
   {
       SecurityAnonymous,
       SecurityIdentification,
       SecurityImpersonation,
       SecurityDelegation
    }

    internal enum TOKEN_TYPE
    {
         TokenPrimary = 1,
         TokenImpersonation
     }

 public class ProcessAsUser
 {

[DllImport("advapi32.dll", SetLastError = true)]
private static extern bool CreateProcessAsUser(
    IntPtr hToken,
    string lpApplicationName,
    string lpCommandLine,
    ref SECURITY_ATTRIBUTES lpProcessAttributes,
    ref SECURITY_ATTRIBUTES lpThreadAttributes,
    bool bInheritHandles,
    uint dwCreationFlags,
    IntPtr lpEnvironment,
    string lpCurrentDirectory,
    ref STARTUPINFO lpStartupInfo,
    out PROCESS_INFORMATION lpProcessInformation);


[DllImport("advapi32.dll", EntryPoint = "DuplicateTokenEx", SetLastError = true)]
private static extern bool DuplicateTokenEx(
    IntPtr hExistingToken,
    uint dwDesiredAccess,
    ref SECURITY_ATTRIBUTES lpThreadAttributes,
    Int32 ImpersonationLevel,
    Int32 dwTokenType,
    ref IntPtr phNewToken);


[DllImport("advapi32.dll", SetLastError = true)]
private static extern bool OpenProcessToken(
    IntPtr ProcessHandle,
    UInt32 DesiredAccess,
    ref IntPtr TokenHandle);

[DllImport("userenv.dll", SetLastError = true)]
private static extern bool CreateEnvironmentBlock(
        ref IntPtr lpEnvironment,
        IntPtr hToken,
        bool bInherit);


[DllImport("userenv.dll", SetLastError = true)]
private static extern bool DestroyEnvironmentBlock(
        IntPtr lpEnvironment);

[DllImport("kernel32.dll", SetLastError = true)]
private static extern bool CloseHandle(
    IntPtr hObject);

private const short SW_SHOW = 5;
private const uint TOKEN_QUERY = 0x0008;
private const uint TOKEN_DUPLICATE = 0x0002;
private const uint TOKEN_ASSIGN_PRIMARY = 0x0001;
private const int GENERIC_ALL_ACCESS = 0x10000000;
private const int STARTF_USESHOWWINDOW = 0x00000001;
private const int STARTF_FORCEONFEEDBACK = 0x00000040;
private const uint CREATE_UNICODE_ENVIRONMENT = 0x00000400;


private static bool LaunchProcessAsUser(string cmdLine, IntPtr token, IntPtr envBlock)
{
    bool result = false;


    PROCESS_INFORMATION pi = new PROCESS_INFORMATION();
    SECURITY_ATTRIBUTES saProcess = new SECURITY_ATTRIBUTES();
    SECURITY_ATTRIBUTES saThread = new SECURITY_ATTRIBUTES();
    saProcess.nLength = (uint)Marshal.SizeOf(saProcess);
    saThread.nLength = (uint)Marshal.SizeOf(saThread);

    STARTUPINFO si = new STARTUPINFO();
    si.cb = (uint)Marshal.SizeOf(si);


    //if this member is NULL, the new process inherits the desktop 
    //and window station of its parent process. If this member is 
    //an empty string, the process does not inherit the desktop and 
    //window station of its parent process; instead, the system 
    //determines if a new desktop and window station need to be created. 
    //If the impersonated user already has a desktop, the system uses the 
    //existing desktop. 

    si.lpDesktop = @"WinSta0\Default"; //Modify as needed 
    si.dwFlags = STARTF_USESHOWWINDOW | STARTF_FORCEONFEEDBACK;
    si.wShowWindow = SW_SHOW;
    //Set other si properties as required. 

    result = CreateProcessAsUser(
        token,
        null,
        cmdLine,
        ref saProcess,
        ref saThread,
        false,
        CREATE_UNICODE_ENVIRONMENT,
        envBlock,
        null,
        ref si,
        out pi);


    if (result == false)
    {
        int error = Marshal.GetLastWin32Error();
        string message = String.Format("CreateProcessAsUser Error: {0}", error);
        Debug.WriteLine(message);

    }

    return result;
}


private static IntPtr GetPrimaryToken(int processId)
{
    IntPtr token = IntPtr.Zero;
    IntPtr primaryToken = IntPtr.Zero;
    bool retVal = false;
    Process p = null;

    try
    {
        p = Process.GetProcessById(processId);
    }

    catch (ArgumentException)
    {

        string details = String.Format("ProcessID {0} Not Available", processId);
        Debug.WriteLine(details);
        throw;
    }


    //Gets impersonation token 
    retVal = OpenProcessToken(p.Handle, TOKEN_DUPLICATE, ref token);
    if (retVal == true)
    {

        SECURITY_ATTRIBUTES sa = new SECURITY_ATTRIBUTES();
        sa.nLength = (uint)Marshal.SizeOf(sa);

        //Convert the impersonation token into Primary token 
        retVal = DuplicateTokenEx(
            token,
            TOKEN_ASSIGN_PRIMARY | TOKEN_DUPLICATE | TOKEN_QUERY,
            ref sa,
            (int)SECURITY_IMPERSONATION_LEVEL.SecurityIdentification,
            (int)TOKEN_TYPE.TokenPrimary,
            ref primaryToken);

        //Close the Token that was previously opened. 
        CloseHandle(token);
        if (retVal == false)
        {
            string message = String.Format("DuplicateTokenEx Error: {0}", Marshal.GetLastWin32Error());
            Debug.WriteLine(message);
        }

    }

    else
    {

        string message = String.Format("OpenProcessToken Error: {0}", Marshal.GetLastWin32Error());
        Debug.WriteLine(message);

    }

    //We'll Close this token after it is used. 
    return primaryToken;

}

private static IntPtr GetEnvironmentBlock(IntPtr token)
{

    IntPtr envBlock = IntPtr.Zero;
    bool retVal = CreateEnvironmentBlock(ref envBlock, token, false);
    if (retVal == false)
    {

        //Environment Block, things like common paths to My Documents etc. 
        //Will not be created if "false" 
        //It should not adversley affect CreateProcessAsUser. 

        string message = String.Format("CreateEnvironmentBlock Error: {0}", Marshal.GetLastWin32Error());
        Debug.WriteLine(message);

    }
    return envBlock;
}

public static bool Launch(string appCmdLine /*,int processId*/)
{

    bool ret = false;

    //Either specify the processID explicitly 
    //Or try to get it from a process owned by the user. 
    //In this case assuming there is only one explorer.exe 

    Process[] ps = Process.GetProcessesByName("explorer");
    int processId = -1;//=processId 
    if (ps.Length > 0)
    {
        processId = ps[0].Id;
    }

    if (processId > 1)
    {
        IntPtr token = GetPrimaryToken(processId);

        if (token != IntPtr.Zero)
        {

            IntPtr envBlock = GetEnvironmentBlock(token);
            ret = LaunchProcessAsUser(appCmdLine, token, envBlock);
            if (envBlock != IntPtr.Zero)
                DestroyEnvironmentBlock(envBlock);

            CloseHandle(token);
        }

    }
    return ret;
}

}