/// <summary> /// Get any critical extensions. /// </summary> /// <returns>A sorted list of critical entension.</returns> public SortedList getCriticalExtensionOIDs() { if (xStruct.getVersion() == 3) { SortedList set = new SortedList(); X509Extensions extensions = xStruct.getTBSCertificate().getExtensions(); if (extensions != null) { IEnumerator e = extensions.oids(); while (e.MoveNext()) { DERObjectIdentifier oid = (DERObjectIdentifier)e.Current;; X509Extension ext = extensions.getExtension(oid); if (ext.isCritical()) { set.Add(oid.getId(), ext); } } return(set); } } return(null); }