/**

@page overview_X500_and_X509 X.500 and X.509 Overview

The X.500 component is a general component that provides services for the handling of X.500 distinguished names.

It implements the @ref DN "Distinguished Name" (DN) as defined in the X.500 standard. An X.500 Distinguished Name consists of a

sequence of \c AttributeTypeAndValue objects, as defined in the X.520 standard. Thus the two public classes implemented in

this DLL are \c CX520AttributeTypeAndValue and \c CX500DistinguishedName.

The X.509 component provides classes for handling @ref X509_certificate "X.509 certificates". It provides an implementation of the X.509 

certificate and its components. In fact X.500 also includes structures from X.520, but for simplicity they are considered 

to be part of X.500.

For the most part, these DLLs simply represent data that the PKIXCert DLL operates on: they are the primary 

input to certificate validation.

In the X.500, X.509 and X.520 standards the structures are specified with Abstract Syntax Notation 1 (@ref ASN "ASN.1") and are 

encoded for transport using the @ref "Basic Encoding Rules" (BER) which encode @ref ASN "ASN.1" as 8-bit binary data.

In addition, when they represent data to be signed, as they do within certificate management, the signature is calculated 

on the data encoded using @ref DER "Distinguished Encoding Rules" (DER: a subset of @ref BER which has the property that the 

same data always encodes to the same binary representation).