Sunday 12 September 2021

Introduce New Custom Active Directory Attribute

 

Introduce New Custom Attribute


Add Custom attribute, to store Service Account owner information.

Creating custom attribute in AD, we need schema dll need to be register first.

Once schema registered, open Schema snap-ins.


 

Select Attributes, and create attribute.

Then, the system will give a warning about schema object creation. Click OK to continue and the following screen will open:




New Attribute form look like below.


Common Name: This is the name of the object. You can only use letters, numbers, and hyphens for the common name (CN).

LDAP Display Name: When an object is referring to a script, program, or command-line utility, it needs to be called using the LDAP display name instead of the CN. When you define the CN, it will automatically create an LDAP Display Name.

Unique X500 Object ID: Each and every attribute in an AD schema has a unique object ID (OID) value. There is a script developed by Microsoft to generate these unique OID values. It can be found at https://gallery.technet.microsoft.com/scriptcenter/Generate-an-Object-4c9be66a#content.

 

It includes the following script, which will generate the OID:

#---

$Prefix="1.2.840.113556.1.8000.2554"

$GUID=[System.Guid]::NewGuid().ToString()

$Parts=@()

$Parts+=[UInt64]::Parse($guid.SubString(0,4), "AllowHexSpecifier")

$Parts+=[UInt64]::Parse($guid.SubString(4,4), "AllowHexSpecifier")

$Parts+=[UInt64]::Parse($guid.SubString(9,4),

"AllowHexSpecifier")

$Parts+=[UInt64]::Parse($guid.SubString(14,4), "AllowHexSpecifier")

$Parts+=[UInt64]::Parse($guid.SubString(19,4), "AllowHexSpecifier")

$Parts+=[UInt64]::Parse($guid.SubString(24,6), "AllowHexSpecifier")

$Parts+=[UInt64]::Parse($guid.SubString(30,6),

"AllowHexSpecifier")

$OID=[String]::Format("{0}.{1}.{2}.{3}.{4}.{5}.{6}.{7}",

$prefix,$Parts[0],$Parts[1],$Parts[2],$Parts[3],$Parts[4],

$Parts[5],$Parts[6])

$oid

#---

Syntax: This defines the storage representation for the object. You are only allowed to use a syntax defined by Microsoft. One attribute can only associate with one syntax. In the following table, I have listed a few commonly used syntaxes:

Syntax

Description

Boolean

True or false

Unicode String

A large string

Numeric String

String of digits

Integer

32-bit numeric value

Large Integer

64-bit numeric value

SID

Security identifier value

Distinguished Name

String value to uniquely identify object in AD

With all the above notes, we will fill the below form.






        As the next step, we need to add it to the user class. In order to do that, go to the Classes container, double-click on the user class,


Click on the Attributes tab. In there, by clicking the Add button, we can browse and select the newly added attribute from the list:



Now when we open a user account, we can see the new attribute. Update owner employee id info,



Now all efforts are done, let see we can retrieve from PowerShell. 



**************************Happy Learning************************