I’m working on an app that will monitor the number of GDI Objects of another process (in this case, the spooler)

To do this in VB.NET requires an API call to GetGuiResources. While testing, I was using Process.GetProcesses to get a list of all the available processes, passed the handle of each process to the API function, and writing the result to a textbox.

Problem was, all process that I did not own throw security errors, even when I set the app to run with elevated privs. The internet once again failed me, and I stumbled across the solution while browsing the system.diagnostics.process documentation on MSDN.

The solution is to call Process.EnterDebugMode() before getting your process list and calling the API, then calling Process.LeaveDebugMode() when you are done.

MSDN EnterDebugMode Documentation

Here is an example. remember to run with elevate privs, and create a multiline textbox called txtOut.

Public Class Form1
  Declare Function GetGuiResources Lib "user32" (ByVal hProcess As Long, ByVal uiFlags As Long) As Long
  ' uiFlags: 0 - Count of GDI objects
  ' uiFlags: 1 - Count of USER objects

  Private Sub btnGo_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnGo.Click
    Dim procList As Process()

    Dim TYPE_GDI As UInteger = 0

    Process.EnterDebugMode()
    procList = Process.GetProcesses

    For Each proc As Process In procList
      Dim objCnt As Long
      Try
        objCnt = GetGuiResources(proc.Handle, TYPE_GDI)
      Catch ex As Exception
        objCnt = -1
      End Try

      txOut.AppendText(proc.ProcessName & vbTab & "GDI: " & objCnt.ToString & vbNewLine)
    Next proc

    Process.LeaveDebugMode()


  End Sub
End Class

Don’t listen to the internet – getting account information from active directory for the current user is simple and easy in Visual Basic .NET – particularly if you are using Framework 3.5 or higher

Note: if you are using ASP.NET, there is a different way to do it – see the update below

You don’t need to do any stinking LDAP queries, or lookups, or credential passings – it’s all made simple using System.DirectoryServices.AccountManagement. Observe.

First, go to the references tab in project properties, click add reference, and find “System.DirectoryServices.AccountManagement” – no need to add “System.DirectoryServices”.

Now, in your application, add the following lines:

Dim currentADUser As System.DirectoryServices.AccountManagement.UserPrincipal
currentADUser = System.DirectoryServices.AccountManagement.UserPrincipal.Current

(It’s even simpler if you import the namespace)

Poof. That’s it! You are done.

currentADUser is a strongly typed object containing attributes for most of the active directory properties you need = such as display name, email address, primary group membership, exchange mailbox info, etc, etc.

Say you want to get the current user’s email address. You could do it like so (after the previous code):

Dim userEmail as string = currentADUser.EmailAddress

That’s it. 1 additional line.

How about a concrete example – here is the problem I wanted to solve. Send an email message from the current user for error reporting – Make sure to change the To: email address, and the smtp server name, and this should be a drop-in solution:

  Private Sub report_error(ByVal errorMessage As String)
    Dim currentADUser As System.DirectoryServices.AccountManagement.UserPrincipal
    currentADUser = System.DirectoryServices.AccountManagement.UserPrincipal.Current
    Dim mailClient As New System.Net.Mail.SmtpClient("smtpserver.company.local")
    mailClient.Send(currentADUser.DisplayName & " <" & currentADUser.EmailAddress & ">", _
                    "notifications@company.com", _
                    "ERROR REPORT: Application error for " & currentADUser.DisplayName, _
                    errorMessage)
  End Sub

Hope this helps!

Update – ASP.NET
The “better” way to get this info in an ASP page is to take advantage of the “User” object available to the ASP.NET Page class. User.Ientity can be cast to a System.Security.Principal.WindowsIdentity, giving you access to the User attribute (yes, User.Identity.User essentially) which is the domain SID. You use this SID to lookup the user in AD.

You check the User.Identity.IsAuthenticated to make sure that IIS has taken care of verifying the identity of the user.

Imports System.Security.Principal
Imports System.DirectoryServices.AccountManagement

Public Class WebForm1
    Inherits System.Web.UI.Page

    Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
        If Not User.Identity.IsAuthenticated Then
            Throw New InvalidOperationException("Specified user is not authenticated")
        End If

        If Not User.Identity.Name.StartsWith("DOMAIN\") Then
            Throw New InvalidOperationException("Specified user is not member of Domain")
        End If

        Dim userSid As String = CType(User.Identity, WindowsIdentity).User.Value

        Dim adContext As PrincipalContext = New PrincipalContext(ContextType.Domain, "Domain.local")

        Dim adUser As UserPrincipal = UserPrincipal.FindByIdentity(adContext, IdentityType.Sid, userSid)

        emaillbl.Text = adUser.EmailAddress



    End Sub

End Class

This example is c# (I switched…) – hopefully you can translate?

using System.Security.Principal;
using System.DirectoryServices.AccountManagement;
 ...
 
if (!User.Identity.IsAuthenticated) throw new InvalidOperationException("Specified user is not authenticated");
 if (!User.Identity.Name.StartsWith("Domain\\")) throw new InvalidOperationException("Specified user is not member of Domain");
 
string userSid = ((WindowsIdentity)User.Identity).User.Value;
 PrincipalContext adContext = new PrincipalContext(ContextType.Domain, "Domain.local");
 UserPrincipal adUser = UserPrincipal.FindByIdentity(adContext, IdentityType.Sid, userSid);
 ...
 

Sorry about the spam comments. Looks like I need to update nucleus. One of these days I will upgrade to wordpress…

If you have purchased a Virgin Mobile Broadband2Go pay as you go aircard (actually a novatell wireless ovation MC760), and find that the driver installation hangs on Windows 7, you will also find that the internet is little help.

The solution is to disable USB Selective Suspending until Virgin Mobile releases a driver version later than 2.02.04.002

http://shup.com/oqo/OQO%20Drivers/02+/2009.01.15/WWAN/Drivers/Novatel/Driver%20Installer%20Release%20Notes%20v2.02.04.002.pdf

Here is the link to the release notes for the OQO drivers – which are newer that either the Virgin Mobile or Novatel generic drivers.

You disable USB selective suspend from the advanced power settings screen.

If you need to install Vmware ESXi (or possibly ESX) 4 on a server without an optical drive – that is, install FROM a USB drive (not “to”), here is how to do in in Windows:

1. Download and extract syslinux: http://syslinux.zytor.com/wiki/index.php/Download

You will want syslinux-3.XX.zip – the latest at time of writing is syslinux-3.83.zip and it works fine.

Extract it somewhere – lets say c:\syslinux

2. Insert the USB drive if you have not already, make sure it is formatted fat32, and make note of the drive letter. For our example, we will use k:.

3. Open a command prompt. (In windows Vista or 7, make sure to Run as Administrator)
Change directory to the place you extracted syslinux \ win32.

cd c:\syslinux\win32
syslinux -m -f -a {drive}:
where {drive} is the drive letter of the USB drive.

4. Extract or copy the contents of the ESX iso image to the USB drive (you can use 7zip or winrar – no need to burn it)

5. rename ISOLINUX.CFG to SYSLINUX.CFG

That should do it.

This is based on info from the following sites – I didn’t really change anything except the version, so if this doesn’t work, they these:
http://www.squishnet.com/?p=17
http://www.vm-help.com/esx40i/ESXi_USB_install.php

The following is my description of how I figured out how to decode the D-Link settings file (aka decrypt gws). If you don’t care how I figured it out, skip to the end for VB.Net code samples and an executable.

I have a DIR-628 wireless router that is having issues. There is a firmware update available, but my issue is not mentioned in the readme for the firmware.
Normally when I upgrade the firmware, I will dump out a settings file, perform the upgrade, reload the settings file, and rejoice in the time saved not having to reconfigure. This time, though, I think I would like to have a clean slate – but there are some options that include passwords I don’t recall offhand, so I figure I can just dump out the settings file, and take a look at it to get all that info…

Wrong. The settings file is binary gobbledeygook.
The default file name is gateway_settings.gws, and the file is about 175k.

I gave Google a thorough searching, and had no luck – it looks like other people are searching for GWS format, or GWS file, but there were no meaningful pages that I could find.
Next I downloaded trid_w32 – a neat little utility for identifying file types. I thought maybe it was compressed or something…
No dice.

So I decided to use the reverse engineering method – make some changes, and observe the result in the file.
I created a firewall rule named “AAAAAAAAAAAA”, and saved the settings; then renamed the rule to “BBBBBBBBBBBB”, and use a nice binary comparison tool (HexCmp in this case) to see what my changes did.

The A’s within the file had become “78 79 7A 7B 7C 7D 7E…” – they were shifted, but that offset increased by 1 for each character. This I can fix!

I then decoded the character before the first A – it was a “>”. Could it be? Could this file really be XML??
Worked backwards a couple more characters and had “name>AAAA…” – yes indeed! The decoded file will be XML!!

The next question was where to begin – what will be the shift of the first character? If the file is xml, I can be pretty sure the first character is a “<” – and this is the first character of the .gws file.

After much fooling around in VB.net, and battling with modulus math, I had the encoder formula:
encodedByte = (positionNbr + CharacterCode) mod 256

Decoding was a bit trickier, because as long as (position mod 256) + characterCode is less than 256, you can just subtract. If it is greater than 256, you have to work a bit harder. If I had more time, I bet there is a way to write a single formula to restore the character code, but I was able to do it with an IF statement.

Here is the VB.net function for decoding a byte array containing the .gws file

  Function decodeGWS(ByRef encodedGWS As Byte()) As String
    Dim chrMax As UInteger
    Dim decodedGWS As Char()
    chrMax = encodedGWS.GetUpperBound(0)
    ReDim decodedGWS(chrMax)

    For i As UInteger = 0 To chrMax
      If encodedGWS(i) < (i Mod 256) Then
        decodedGWS(i) = Chr((256 + encodedGWS(i)) - (i Mod 256))
      Else
        decodedGWS(i) = Chr(encodedGWS(i) - (i Mod 256))
      End If
    Next i

    Return decodedGWS
  End Function

And it works like a charm. The file is actually a great big XML containing all the available options.

Here is the little utility I wrote to decode the file:
GWS Decoder Utility

For completeness sake, I included encoder functionality, and I have verified that the output is identical to the original file when no changes are made to the xml file, but I really don’t know what would happen if you tried to make changes to the XML and load it back onto your router. If you want to try it, don’t come crying to me when your router gives up it’s magic smoke, or your house burns down.

Hopefully somebody finds this helpful!

Update 9/22/2010
There are a couple comments from people saying the utility doesn’t work with some different routers. The only way I could even try to fix it is to get sample files. Nobody has responded to my requests for samples yet.

Update 6/2/2011
A user has commented that Norton is reporting the file as containing malware. I checked the file on virustotal.com as well as virusscan.jotti.org and it came back 100% clean. When I can find the source I will try to rewrite it in C# (for self respect purposes) but until then if you don’t trust me, you can feel free to decompile the contained executable – or check it yourself with multiple scanners.

If you have a dell inspiron 1545 like I do, you might be happy with your laptop. Happy with everything except this godawful excuse for a touchpad! (and the missing bluetooth, and wireless-N – but these can be resolved)

ALPS touchpads suck. They are jumpy, at the same time unresponsive and too responsive, the scroll feature never seems to work right the first time… so yeah. I don’t like it.

Turns out some of the issues can be mitigated by using Acer drivers. They are less customized, and include newer versions of various components. The scrolling is more reliable, and they don’t freeze up under load like the Dell drivers.

I used the drivers from here:
http://drivers.softpedia.com/get/KEYBOARD-and-MOUSE/OTHERS/Acer-Aspire-3810TZ-Notebook-ALPS-Touchpad-Driver-752021101-for-Vista.shtml

or search for Acer aspire ALPS drivers on google.

Hope this helps!