I had a similar problem where I was writing a tool that needed to run on a machine on one domain and authenticate with a SQL server on another domain using a trusted connection. Everything I could find on the subject said it couldn't be done. Instead you must join the domain, use SQL authentication, get involved with some chap called Kerberos, or get your network guys to setup a trusted relationship, to name a few alternatives.
The thing is I knew I could get it working in some way using RUNAS because I'd proven it with SSMS:
C:WINDOWSsystem32
unas.exe /netonly /savecred /user:megacorpjoe.bloggs "C:Program FilesMicrosoft SQL Server90ToolsBinnVSShellCommon7IDESqlWb.exe"
The /netonly flag allowed me to execute the exe with the local credentials and access the network with the remote credentials, I think, anyway I got the result set I expected from the remote server. The problem was the runas command made it very difficult to debug the application, and it didn't smell good.
Eventually I found this article on the code project which was talking about authenticating to manipulate Active Directory, Here is the main class that does the impersonation:
using System;
using System.Runtime.InteropServices; // DllImport
using System.Security.Principal; // WindowsImpersonationContext
namespace TestApp
{
class Impersonator
{
// group type enum
enum SECURITY_IMPERSONATION_LEVEL : int
{
SecurityAnonymous = 0,
SecurityIdentification = 1,
SecurityImpersonation = 2,
SecurityDelegation = 3
}
// obtains user token
[DllImport("advapi32.dll", SetLastError = true)]
static extern bool LogonUser(string pszUsername, string pszDomain, string pszPassword,
int dwLogonType, int dwLogonProvider, ref IntPtr phToken);
// closes open handes returned by LogonUser
[DllImport("kernel32.dll", CharSet = CharSet.Auto)]
extern static bool CloseHandle(IntPtr handle);
// creates duplicate token handle
[DllImport("advapi32.dll", CharSet = CharSet.Auto, SetLastError = true)]
extern static bool DuplicateToken(IntPtr ExistingTokenHandle,
int SECURITY_IMPERSONATION_LEVEL, ref IntPtr DuplicateTokenHandle);
WindowsImpersonationContext newUser;
///
/// Attempts to impersonate a user. If successful, returns
/// a WindowsImpersonationContext of the new users identity.
///
/// Username you want to impersonate
/// Logon domain
/// User's password to logon with
///
public Impersonator(string sUsername, string sDomain, string sPassword)
{
// initialize tokens
IntPtr pExistingTokenHandle = new IntPtr(0);
IntPtr pDuplicateTokenHandle = new IntPtr(0);
pExistingTokenHandle = IntPtr.Zero;
pDuplicateTokenHandle = IntPtr.Zero;
// if domain name was blank, assume local machine
if (sDomain == "")
sDomain = System.Environment.MachineName;
try
{
const int LOGON32_PROVIDER_DEFAULT = 0;
// create token
// const int LOGON32_LOGON_INTERACTIVE = 2;
const int LOGON32_LOGON_NEW_CREDENTIALS = 9;
//const int SecurityImpersonation = 2;
// get handle to token
bool bImpersonated = LogonUser(sUsername, sDomain, sPassword,
LOGON32_LOGON_NEW_CREDENTIALS, LOGON32_PROVIDER_DEFAULT, ref pExistingTokenHandle);
// did impersonation fail?
if (false == bImpersonated)
{
int nErrorCode = Marshal.GetLastWin32Error();
// show the reason why LogonUser failed
throw new ApplicationException("LogonUser() failed with error code: " + nErrorCode);
}
bool bRetVal = DuplicateToken(pExistingTokenHandle, (int)SECURITY_IMPERSONATION_LEVEL.SecurityImpersonation, ref pDuplicateTokenHandle);
// did DuplicateToken fail?
if (false == bRetVal)
{
int nErrorCode = Marshal.GetLastWin32Error();
CloseHandle(pExistingTokenHandle); // close existing handle
// show the reason why DuplicateToken failed
throw new ApplicationException("DuplicateToken() failed with error code: " + nErrorCode);
}
else
{
// create new identity using new primary token
WindowsIdentity newId = new WindowsIdentity(pDuplicateTokenHandle);
WindowsImpersonationContext impersonatedUser = newId.Impersonate();
newUser = impersonatedUser;
}
}
finally
{
// close handle(s)
if (pExistingTokenHandle != IntPtr.Zero)
CloseHandle(pExistingTokenHandle);
if (pDuplicateTokenHandle != IntPtr.Zero)
CloseHandle(pDuplicateTokenHandle);
}
}
public void Undo()
{
newUser.Undo();
}
}
}
To use it just:
Impersonator impersonator = new Impersonator("username", "domain", "password");
//Connect to and use SQL server
impersonator.Undo();
I added in the Undo method otherwise the impersonator object tended to get garbage collected. I also altered the code to use LOGON32_LOGON_NEW_CREDENTIALS but this was a poke and run to make it work; I still need to understand fully what it does, I have a feeling its the same as the /netonly flag on runas. I'm also going to break down the constructor a bit.