Question

weird :

I use this code to find certificate via c# by this code :

 X509Store store = new X509Store(StoreName.My, StoreLocation.CurrentUser);
 store.Open(OpenFlags.ReadOnly | OpenFlags.OpenExistingOnly);
 var certificates = store.Certificates;
 X509Certificate2Collection certificateCollection = store.Certificates.Find(X509FindType.FindBySerialNumber, "the Serial Number", false);

So I tested to see by an existing certificate :

but it didn’t worked (as mentioned in the linked question). ( Also tried , remove spaces , capital etc… – non worked).

But when I played with it a bit I found another serial location :

this time just pasted the exact phrase "4e a1 ae 96 ec 1a b6 82 4e f6 23 9a 16 04 1a 51" and it worked .

What is going on here ?

why there are 2 different serial numbers and what are the differences between them ?

p.s. , However , not all certificates has the “Authority Key Identifier ” , so there’s still a problem finding by other properties…

Answer 1

The authority key identifier is an additional extension you can add to a certificate which indicates the issuer certificate which signed it. It isn’t required because there is already the Issuer field which indicates the subject name of the issuer certificate but having the extension allows to more accurately specify it.