public static string GetSubjectOrganizationalUnit(X509Certificate2 certificate) { var x509Name = new X509Name(certificate.SubjectName.Name); var oids = x509Name.GetOids(); for (int i = 0; i < oids.Count; i++) { var oid = oids[i]; if (ObjectIdentifiers.OrganizationalUnit.Equals(oid.ToString())) { return(x509Name.GetValues()[i].ToString()); } } return(null); }