FindByThumbprint - certificate exists but not found

Question

I am trying to add a certificate to a web request to connect to Azure services.

My code looks like this:

string certThumbprint = "‎‎thumbprint";
X509Store certStore = new X509Store(StoreName.My, StoreLocation.CurrentUser);
X509Certificate2Collection certCollection = certStore.Certificates.Find(
     X509FindType.FindByThumbprint, certThumbprint, false);

Now I can confirm that the certificate does exist and the thumbprint is correct. However certCollection comes back empty.

Any ideas?

Update: here is how I open the cert store

certStore.Open(OpenFlags.ReadOnly);

Answer 1

You probably have a hidden character or two at the very beginning of your thumbprint. I've made this mistake many times before when copying the thumbprint from the certificate manager in MMC. Here is a link for more information on this issue. http://support.microsoft.com/kb/2023835