So, one of the reasons why I like to teach PowerShell is
that every once and a while, someone comes up with an unusual idea. So here it
goes. Can you save a BLOB file in an XML
file? This is strictly for the sake of
theory. In the process, we discovered
some different behavior of Get-Content.
Off the top of my head, the only way that I knew how to
create a BLOB file is with an Offline Domain Join. Here is the Wikipedia definition of a BLOB:
A Binary Large Object
(BLOB) is a collection of binary data stored as a single entity in a database
management system. Blobs are typically images, audio or other multimedia
objects, though sometimes binary executable code is stored as a blob.
An Offline Domain Join allows you to create an object in
Active Directory for a new client without the client being available. It also allows to client to be configured to
join the domain once it is able to contact a Domain Controller. To get this to work, you need to create a
BLOB file with the DJoin command and send that BLOB file to the client.
So, here we go….
This will execute the provisioning portion of an ODJ. Since this is a PowerShell class, I used Invoke-Expression.
# Offline Domain Join
Invoke-Expression -Command "djoin
/provision /domain adatum.com /machine LON-SVR1 /SaveFile C:\PS\DJoin.txt"
Here is what the BLOB file looks like. Not much to look at.
# View the BLOB
Get-Content -Path C:\ps\DJoin.txt
ARAIAMzMzMyAAwAAAAAAAAAAAgABAAAAAQAAAAQAAgABAAAAAQAAAFgDAAAIAAIAWAMAAAEQCADMzMzMSAMAAAAAAACQJ/RsADrzbABE82xg3
PJsDAAOAJB682wUABYAAEfzbBQAFgCAQvNse3803ox6YU6lMRUWqlSC3kA582ywnPJsgETzbAEAAAB7fzTejHphTqUxFRaqVILewEDzbMA+82
z98QDg4DH0bGAq9GwAAAAACwAAAAAAAAALAAAAYQBkAGEAdAB1AG0ALgBjAG8AbQAAAAAACQAAAAAAAAAJAAAATABPAE4ALQBTAFYAUgAxAAA
AAAB5AAAAAAAAAHkAAAAlAGsAbQBjAEsAVQAlACAAegBgAEsAWQAkAEIARABaADcASABmAGAAbABSAHgAKQBTAGMAWABWAF0AXwA2AEkAJQBi
AE4AYQBdAGgAbgAiADMANgA/AFcAYwBdAHoAcwBtAEoAIQBJACgANwB5AFwAVwAhADgAXQA9AGMAXABEAEoAUwBEADsAIwBGACsAVwAwADEAd
gByADsAOgBXACsALQBmAD0AZABlAFcAIwBeADcAKgAwAD0AKwA/ACIAKwB3ADMAbgBrADYATgAhAE4AUABMAGUAdABiAEwAKQBZACcAQwBCAG
AAWwBXAGMARAAAAAAABwAAAAAAAAAGAAAAQQBEAEEAVABVAE0ACwAAAAAAAAAKAAAAQQBkAGEAdAB1AG0ALgBjAG8AbQALAAAAAAAAAAoAAAB
BAGQAYQB0AHUAbQAuAGMAbwBtAAQAAAABBAAAAAAABRUAAABDGsFH3xdvCMGS/FIVAAAAAAAAABUAAABcAFwATABPAE4ALQBEAEMAMQAuAEEA
ZABhAHQAdQBtAC4AYwBvAG0AAAAAAAsAAAAAAAAACwAAAFwAXAAxADAALgAwAC4AMAAuADIAAAAAAAsAAAAAAAAACwAAAEEAZABhAHQAdQBtA
C4AYwBvAG0AAAAAAAsAAAAAAAAACwAAAEEAZABhAHQAdQBtAC4AYwBvAG0AAAAAABgAAAAAAAAAGAAAAEQAZQBmAGEAdQBsAHQALQBGAGkAcg
BzAHQALQBTAGkAdABlAC0ATgBhAG0AZQAAABgAAAAAAAAAGAAAAEQAZQBmAGEAdQBsAHQALQBGAGkAcgBzAHQALQBTAGkAdABlAC0ATgBhAG0
AZQAAAAAAAAAAAAAA
# Save as an CliXML
Get-Content -Path C:\ps\DJoin.txt |
Export-Clixml -Path
c:\ps\DJoin.xml
# View the XML File
Notepad C:\ps\DJoin.xml
Unfortunately, I cannot display the XML file in this blog. Go ahead and take a look at it. Keep scrolling down, something is not right. This is what threw my off.
Take a close look. There is a lot
more information here than the String object sent to Export-CliXML. As a matter of fact, I’m seeing the size of
my hard drive!!!! The reason is that Get-Content
added a few note properties.
PS C:\> Get-Content -Path C:\ps\DJoin.xml | Get-Member
-MemberType NoteProperty
TypeName:
System.String
Name
MemberType Definition
----
---------- ----------
PSChildName
NoteProperty System.String PSChildName=DJoin.xml
PSDrive
NoteProperty System.Management.Automation.PSDriveInfo PSDrive=C
PSParentPath NoteProperty System.String
PSParentPath=C:\ps
PSPath
NoteProperty System.String PSPath=C:\ps\DJoin.xml
PSProvider
NoteProperty System.Management.Automation.ProviderInfo
PSProvider=Microsoft.PowerShell.Core\F...
ReadCount
NoteProperty System.Int64 ReadCount=1
These are not part of a normal string object. These note properties are responcible for
some of the excess information in the XML.
At this point, I was thinking that this is going to fail at the client
end. In any case, the provisioning worked:
PS C:\ps> Get-ADComputer -Identity LON-SVR1
DistinguishedName : CN=LON-SVR1,CN=Computers,DC=Adatum,DC=com
DNSHostName :
LON-SVR1.Adatum.com
Enabled :
True
Name :
LON-SVR1
ObjectClass :
computer
ObjectGUID :
b2c4be2e-bcbb-48cc-be8c-18313600d8ac
SamAccountName :
LON-SVR1$
SID :
S-1-5-21-1203837507-141498335-1392284353-4103
UserPrincipalName :
Next we manually copied the XML file to the destination
client and executed these commands.
# Create a new directory.
New-Item -Path c: -Name PS -ItemType Directory
# Import the XML File
Import-Clixml -Path C:\ps\DJoin.xml |
Out-file -FilePath
c:\ps\djoin.txt
Invoke-Expression -Command "djoin
/requestodj /loadfile c:\ps\djoin.txt
/WindowsPath c:\Windows /localos"
We received the normal restart required command and after
the restart, the client was on the domain. Surprise!!!!!
OK, again, this was just for the sake of theory. No practical usage was implied. We were just having some fun.
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