How to use DER-encoded OCTET string for the extension value returned by X509Certificate::getExtensionValue(oid)

Question

I am trying to manage the CRL cache locally to customize the cache timeout. The default implementation provided by Sun does not give ability to customize it.

First step for this is to get the CRL Distribution URL from the X509Certificate object using method getExtensionValue(oid).

But it returns DER-encoded OCTET string which we can not directly use download the CRL.

Can someone please suggest the solution to solve the problem?

Thank You.