Impersonate user conundrum

Question

Hi

I'm using VS c++ 2010 on an xp sp3 pc.

Script 1

When I write a simple console application to test impersonation:

...

using namespace System::Runtime::InteropServices;
using namespace System::Security::Principal;
using namespace System::Security::Permissions;


[DllImport("advapi32.dll",SetLastError=true)]
bool LogonUser( String^ lpszUsername, String^ lpszDomain, String^ lpszPassword, int dwLogonType, int dwLogonProvider, IntPtr * phToken );

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

void impersonate() {
    IntPtr tokenHandle = IntPtr(0);

    String^ userName    = "xxx";
    String^ domainName    = "yyy";
    String^ password    = "zzz";

    //This parameter causes LogonUser to create a primary token.
    //const int LOGON32_PROVIDER_DEFAULT = 0; 
    //const int LOGON32_LOGON_INTERACTIVE = 2;
    const int SecurityImpersonation = 2;
    tokenHandle = IntPtr::Zero;

    // Call LogonUser to obtain a handle to an access token.

    bool returnValue = LogonUser( userName, domainName, password, 2, 0,  &tokenHandle );
    Console::WriteLine( "LogonUser called." );
    if ( false == returnValue )
    {
    int ret = Marshal::GetLastWin32Error();
    Console::WriteLine( "LogonUser failed with error code : {0}", ret );
    throw gcnew System::ComponentModel::Win32Exception( ret );
    }
    Console::WriteLine( "Did LogonUser Succeed? {0}", (returnValue ? (String^)"Yes" : "No") );
    Console::WriteLine( "Value of Windows NT token: {0}", tokenHandle );

    // Check the identity.
    Console::WriteLine( "Before impersonation: {0}", WindowsIdentity::GetCurrent()->Name );

    // The token that is passed to the following constructor must
    // be a primary token in order to use it for impersonation.
    WindowsIdentity^ newId = gcnew WindowsIdentity( tokenHandle );
    WindowsImpersonationContext^ impersonatedUser = newId->Impersonate();

    // Check the identity.
    Console::WriteLine( "After impersonation: {0}", WindowsIdentity::GetCurrent()->Name );

    // Stop impersonating the user.
    impersonatedUser->Undo();

    // Check the identity.
    Console::WriteLine( "After Undo: {0}", WindowsIdentity::GetCurrent()->Name );

    // Free the tokens.
    if ( tokenHandle != IntPtr::Zero ) CloseHandle( tokenHandle );

    Console::ReadLine();

}

int main()
{
    impersonate();

}

This works just fine.

 

Script 2

When I put the above code into a clr form script, the form appears and then this error message::

An unhandled exception of type 'System.ComponentModel.Win32Exception' occurred in Login.exe

Additional information: Logon failure: unknown user name or bad password

Can someone suggest where I'm going wrong please? Don't have any more hair to pull out.

 

Thanks

 

 

 

Answer 1

Think I've found my mistake. Needed:

 

bool returnValue = LogonUser(userName, domainName, password, 9, 0, &tokenHandle);

 

i.e LOGON32_LOGON_NEW_CREDENTIALS = 9

 

Ignore my request for help - for now at least.

Answer 2

Hi,

 

I'm glad to hear that you have resolved your issue and thanks for sharing your solution here.

 

Best Regards,

Rob

---

Rob Pan [MSFT]
MSDN Community Support | Feedback to us
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Answer 3

Hi again

At work now and sadly my initial thoughts are wrong. The original posting still stands. In summary:

 

I'm running a login script. Form loads and I'm trying to create an impersonation on the XP PC so the user has additional rights,. Using Dot net4, SP3.

 

impersonation works in a simple console application run on the PC.

 

When I embed the same code in a managed c++ script I get:

 

A first chance exception of type 'System.ComponentModel.Win32Exception' occurred in Login.exe
An unhandled exception of type 'System.ComponentModel.Win32Exception' occurred in Login.exe

Additional information: Logon failure: unknown user name or bad password

The program '[6312] Login.exe: Managed (v4.0.30319)' has exited with code 1073807364 (0x40010004).

 

bool returnValue = LogonUser(userName, domainName, password, 2, 0, &tokenHandle); // - no success managed script

 

bool returnValue = LogonUser(userName, domainName, password, 2, 0, &tokenHandle); // - OK console script

 

At the point of screaming.

 

Help much appreciated.