Tag Archives: windows

Windows knowhow, Windows Scripts

Windows: Set network parameters from command line by using WMIC.exe

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Hi,

you can use wmic.exe  to set some network parameters (and much more, its WMI!!) from command line. Syntax is very hard, but it works :-).

For Example. If you want to disable the DNS registration of all enabled Intel e1000 network adapters.

wmic path Win32_NetworkAdapterConfiguration where (IPEnabled="true" and ServiceName="E1G60") call SetDynamicDNSRegistration False,False

The Filter in the braces is the where condition of wmi “select * from NetworkAdapterConfiguration where IPEnabled=’true’ and ServiceName=’E1G60′ ” statement.  Modify this for your needs. By using WMI queries this is much more flexible than netsh command lines.

Michael

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OpenVPN, Windows Scripts

OpenVPN: Generate a random MAC Address for TAP Interfaces on Windows

1 Comment

Hi,

if you use some image based technology to deploy your Windows installation, for example SCCM, MDT, Acronis and/or sysprep based, and OpenVPM is already included, the MAC Address of the TAP LAN interface isn’t changed by that way. But a unique MAC Address is requiered if the clients conntects to the same OpenVPN server. If multiple clients have the same MAC Address ping from VPN Clients sometimes fails with error “TTL expired in transit” and the VPN connection is unstable.

This powershellscript sets a MAC Address for each OpenVPN TAP adapter. In detail:

  • Creating a Eventlog TAPsetMAC
  • Get all instances for TAP Adapters by reading HKLM\SYSTEM\CurrentControlSet\Control\Class\{4D36E972-E325-11CE-BFC1-08002BE10318}\MatchingDeviceID == “tap0901”
  • Generate a random MAC Address. Starting with Prefix defined in $sMACPrefix.
  • Writing the MAC to each Adapter
  • Log the result to the EventLog
########################################################
# Generate a random MAC for all OpenVPN tap LAN interfaces
#  Michael Albert
#  05.04.2013
# License: GPLv2
########################################################
# HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class\{4D36E972-E325-11CE-BFC1-08002BE10318}
# MatchingDeviceID tap0901
# REG_SZ MAC=00-FF-8F-E3-A1-AE
$oRandom=New-Object System.random
function fGetRandomMAC([string]$sMACStart){
     if($sMACStart.length -ge 0 -and $sMACStart.length -le 11){
          for($iLoop=$sMACStart.length; $iLoop -le 11; $iLoop++){
               $iChar=$oRandom.Next(16)
               $sMACStart+=[String]::Format("{0:x}", $iChar).ToUpper()
          }
          return($sMACStart)
     }
     else{
          return $false
     }
}
function fConvert2MAC16([string]$sMAC12){
     [string]$sMAC16=""
     if($sMAC12.length -eq 12){
          for($iLoop=0;$iLoop -le 11;$iLoop++){
               $sMAC16+=$sMAC12.SubString($iLoop,1)
               if((($iLoop+1) % 2) -eq 0 -and ($iLoop+1) -lt 12){
                    $sMAC16+="-"
               }
          }
          return $sMAC16
     }
     else{
          return $false
     }
}
###############################################################################
# Currently not used but defined :-)
function fValidMAC([system.string]$sMAC){
          $RegExIP=new-object System.Text.RegularExpressions.Regex("^([0-9a-fA-F]{2}\-){5}([0-9a-fA-F]{2})$")
          return($RegExIP.IsMatch($sMAC))
}
###############################################################################
## MAIN
###############################################################################
$sMACPrefix="00FF8F"
if(! [System.Diagnostics.EventLog]::SourceExists("TAPsetMAC")){
     New-EventLog -Source TAPsetMAC -Log Application
}
$aTAPAdapter=Get-ChildItem "registry::HKLM\SYSTEM\CurrentControlSet\Control\Class\{4D36E972-E325-11CE-BFC1-08002BE10318}" -ErrorAction SilentlyContinue |where-object{$_.GetValue("MatchingDeviceID") -eq "tap0901"}
foreach($rTAPAdapter in $aTAPAdapter){
     # Get-ItemProperty -Path "registry::HKLM\SYSTEM\CurrentControlSet\Control\Class\{4D36E972-E325-11CE-BFC1-08002BE10318}"
     if(! ($rTAPAdapter.GetValue("MAC"))){
          #$rTAPAdapter
          #$rTAPAdapter.Name
          # Get-ItemProperty -Path ("registry::"+$rTAPAdapter.Name)
          $sMAC=fGetRandomMAC $sMACPrefix
          if($sMAC16=fConvert2MAC16 $sMAC){
               Write-Host -NoNewline  "Set MAC of TAP Adaper to" $sMAC16 "..."
               $Error.Clear()
               New-ItemProperty -Path ("registry::"+$rTAPAdapter.Name) -Force -Name MAC -PropertyType String -Value $sMAC16|Out-Null
               if(! $Error){
                    Write-Host "ok"
                    Write-EventLog -LogName Application -Source TAPsetMAC -EntryType Information -EventID 666 -Message ("TAP LAN Adapter: Altered MAC Address to "+$sMAC16)
               }
               else{
                    Write-EventLog -LogName Application -Source TAPsetMAC -EntryType Warning -EventID 666 -Message ("TAP LAN Adapter: Failed to altered MAC Address to "+$sMAC16)
               }
          }
     }
}

Michael

Windows Scripts, XML

Powershell: Some basic XML handling with Powershell and .NET

9 Comments

Hi everybody,

here are some fundamentals to handle XML Files with powershell.

The following commands uses these XML File


<config description="Config file for testing">
    <system description="Document Management">
        <document authorFirstName="Kirk" authorSurname="Author1" date="20130503 01:15:43" description="Document Hammet" index="3">C:\temp\doc0001.txt</document>
        <document authorFirstName="Lars" authorSurname="Author5" date="20130503 10:05:42" description="Document Ulrich" index="4">C:\temp\doc0002.txt</document>
        <document authorFirstName="Cliff" authorSurname="Author5" date="20130612 11:54:33" description="Document Burton"  index="6">C:\temp\doc0051.txt</document>
        <document authorFirstName="Jason" authorSurname="Author2" date="20130806 04:02:41" description="Document Newsted"  index="1">C:\temp\doc0041.txt</document>
        <document authorFirstName="Robert" authorSurname="Smith" date="20131202 07:12:03" description="Document Trujillo"  index="2">C:\temp\doc0012.txt</document>
        <document authorFirstName="James" authorSurname="Smith" date="20130211 09:05:59" description="Document Hetfield"  index="5">C:\temp\doc0003.txt</document>
    </system>
</config>

Creating  a XML File, create a document root, create subelements, add and set attributes, save the file

# Create a new XML File with config root node
[System.XML.XMLDocument]$oXMLDocument=New-Object System.XML.XMLDocument
# New Node
[System.XML.XMLElement]$oXMLRoot=$oXMLDocument.CreateElement("config")
# Append as child to an existing node
$oXMLDocument.appendChild($oXMLRoot)
# Add a Attribute
$oXMLRoot.SetAttribute("description","Config file for testing")
[System.XML.XMLElement]$oXMLSystem=$oXMLRoot.appendChild($oXMLDocument.CreateElement("system"))
$oXMLSystem.SetAttribute("description","Document Management")
# Save File
$oXMLDocument.Save("c:\temp\config.xml")

Loading an existing XML File, read an element, do some XPATH queries

Continue reading Powershell: Some basic XML handling with Powershell and .NET →

C#, Windows knowhow

Windows: Create a new local User Account and add them to a local group by using .NET and C#

2 Comments

Hi,

a short post. It describes how to create a new local Windows User account and add them to an existing local user group.

First of all, include the following references in your project:


using System.DirectoryServices;
using System.Runtime.InteropServices;

Create a new User with local administrator rights.

// define Username and Password
const string USER_NAME = "NewAdmin";
char[] aPWchars = { 'P', 'a', 's', 's' , 'w', 'o', 'r', 'd'};
System.Security.SecureString oPW = new System.Security.SecureString();
foreach (char cChr in aPWchars) {
    oPW.AppendChar(cChr);
}
// Get Computerobject via ADSI
DirectoryEntry oComputer = new DirectoryEntry("WinNT://" + Environment.MachineName + ",computer");
// New User
DirectoryEntry oNewUser = oComputer.Children.Add(USER_NAME, "user");
// define Pointer to a string
IntPtr pString = IntPtr.Zero;
// Pointer to password
pString = Marshal.SecureStringToGlobalAllocUnicode(oPW);
// Set password
oNewUser.Invoke("SetPassword", new object[] { Marshal.PtrToStringUni(pString) });
// Add a description
oNewUser.Invoke("Put", new object[] { "Description", "New Administrator" });
// Save changes
oNewUser.CommitChanges();
// Cleanup and free Password pointer
Marshal.ZeroFreeGlobalAllocUnicode(pString);
// Get Group
DirectoryEntry oGroup = oComputer.Children.Find("Administrators", "group");
// And add the recently created user
oGroup.Invoke("Add", new object[] { oNewUser.Path.ToString() });

Michael