Impersonates as a user like "runas /netonly" feature.

Impersonator.cs

// Check http://pinvoke.net/default.aspx/advapi32/LogonUser.html for Win32 functions and structures.

// Code based on answer on SO: https://stackoverflow.com/a/11672293/315151

// Impersonates as a user like "runas /netonly" feature.
public static void Impersonate(string userName, string password, string domain, Action action)
{
    if (action == null)
    {
        return;
    }

    IntPtr token = IntPtr.Zero;

    try
    {
        if (!Win32.RevertToSelf())
        {
            throw new Win32Exception(Marshal.GetLastWin32Error());
        }

        if (Win32.LogonUser(
                userName,
                domain,
                password,
                (int)LogOnType.LOGON32_LOGON_NEW_CREDENTIALS,
                (int)LogOnProvider.LOGON32_PROVIDER_WINNT50,
                ref token) == 0)
        {
            throw new Win32Exception(Marshal.GetLastWin32Error());
        }

        IntPtr tokenDuplicate = IntPtr.Zero;
        if (Win32.DuplicateToken(token, (int)SECURITY_IMPERSONATION_LEVEL.SecurityDelegation, ref tokenDuplicate) == 0)
        {
            throw new Win32Exception(Marshal.GetLastWin32Error());
        }

        using var safeAccessTokenHandle = new SafeAccessTokenHandle(tokenDuplicate);
        WindowsIdentity.RunImpersonated(safeAccessTokenHandle, action);
    }
    finally
    {
        if (token != IntPtr.Zero)
        {
            Win32.CloseHandle(token);
        }
    }
}

/*

Usage:

    Impersonate(userName, password, domain, () =>
    {
        Your code
    });

*/