How to obtain an OID to be used in a custom object class for LDAP

This is related to my previous post on introducing custom object class/attributes to a LDAP instance.

According to this specification on defining LDAP attributes, object classes, we need to have a unique OID for that attribute/object class , for that to be uniquely identified by the LDAP directory server. 

Hence the sole purpose of using an OID, is to avoid it being conflicted with existing object class/attributes in the LDAP server or those which will be added to the LDAP server in the future.

We can use a made up OID for experimental use, but it is recommended to use a registered OID which is unique, if we are going to ship it with a product as described in detail here and here.

There are several ways of obtaining an OID among which one easy and free way of obtaining it is from IANA. For that you need to fill and submit this application. Once you are assigned an OID, it will be displayed in the public PEN registry.

Another interesting thing is that there is a test branch (starting from 2.25) created so that we can use an unregistered OID with a generated UUID appended.

You may follow the following steps to obtain an OID from the test branch  easily.

1. Obtain a generated UUID from here. (When you click "Get a new UUID" button in that page, you will get a hexadecimal value, which you can not use as it is)

2. Convert it to the proper format. You can easily get this converted in OID format by clicking the "Register your UUID as an OID" button in the resulting page.

3. Step 2 will redirect you to the OID registration page which will show the corresponding OID for the generated UUID in step 1. Here, you can copy the OID and use it without registering or you can proceed registering this generated OID.