<?xml version="1.0" encoding="UTF-8"?>
<xsd:schema targetNamespace="http://cpe.mitre.org/dictionary/2.0" xmlns:cpe_dict="http://cpe.mitre.org/dictionary/2.0"
    xmlns:xsd="http://www.w3.org/2001/XMLSchema" elementFormDefault="qualified" attributeFormDefault="unqualified"
    xmlns:cpe-name="http://cpe.mitre.org/naming/2.0" version="2.3">
    <xsd:import namespace="http://www.w3.org/XML/1998/namespace" schemaLocation="https://www.w3.org/2009/01/xml.xsd"/>
    <xsd:annotation>
        <xsd:documentation xml:lang="en">This is an XML Schema for the CPE Dictionary. It is used to transfer a
            collection of official CPE Names along with any necessary supporting information (title, references,
            automated check, etc.) For more information, consult the CPE Specification document.</xsd:documentation>
        <xsd:appinfo>
            <schema>CPE Dictionary</schema>
            <author>Neal Ziring, Andrew Buttner, David Waltermire</author>
            <version>2.3</version>
            <date>2011-07-29</date>
        </xsd:appinfo>
    </xsd:annotation>
    <!-- =============================================================================== -->
    <!-- =============================================================================== -->
    <!-- =============================================================================== -->
    <xsd:import namespace="http://cpe.mitre.org/naming/2.0" schemaLocation="/schema/cpe/2.3/cpe-naming_2.3.xsd"/>
    <xsd:element name="cpe-list" type="cpe_dict:ListType">
        <xsd:annotation>
            <xsd:documentation xml:lang="en">The cpe-list element acts as a top-level container for CPE Name items. Each
                individual item must be unique. Please refer to the description of ListType for additional information
                about the structure of this element.</xsd:documentation>
        </xsd:annotation>
        <xsd:key name="itemURIKey">
            <xsd:selector xpath="./cpe_dict:cpe-item"/>
            <xsd:field xpath="@name"/>
        </xsd:key>
    </xsd:element>
    <xsd:element name="cpe-item" type="cpe_dict:ItemType">
        <xsd:annotation>
            <xsd:documentation xml:lang="en">The cpe-item element denotes a single CPE Name. Please refer to the
                description of ItemType for additional information about the structure of this
                element.</xsd:documentation>
        </xsd:annotation>
        <xsd:unique name="titleLangKey">
            <xsd:selector xpath="./cpe_dict:title"/>
            <xsd:field xpath="@xml:lang"/>
        </xsd:unique>
        <xsd:unique name="notesLangKey">
            <xsd:selector xpath="./cpe_dict:notes"/>
            <xsd:field xpath="@xml:lang"/>
        </xsd:unique>
        <xsd:unique name="checkSystemKey">
            <xsd:selector xpath="./cpe_dict:check"/>
            <xsd:field xpath="@system"/>
        </xsd:unique>
    </xsd:element>
    <!-- =============================================================================== -->
    <!-- =============================  SUPPORTING TYPES  ============================== -->
    <!-- =============================================================================== -->
    <xsd:complexType name="GeneratorType">
        <xsd:annotation>
            <xsd:documentation xml:lang="en">The GeneratorType complex type defines an element that is used to hold
                information about when a particular document was compiled, what version of the schema was used, what
                tool compiled the document, and what version of that tool was used. Additional generator information is
                also allowed although it is not part of the official schema. Individual organizations can place
                generator information that they feel is important and it will be skipped during the validation. All that
                this schema really cares about is that the stated generator information is there.</xsd:documentation>
        </xsd:annotation>
        <xsd:sequence>
            <xsd:element name="product_name" type="xsd:string" minOccurs="0" maxOccurs="1">
                <xsd:annotation>
                    <xsd:documentation xml:lang="en">The optional product_name element specifies the name of the
                        application used to generate the file.</xsd:documentation>
                </xsd:annotation>
            </xsd:element>
            <xsd:element name="product_version" type="xsd:string" minOccurs="0" maxOccurs="1">
                <xsd:annotation>
                    <xsd:documentation xml:lang="en">The optional product_version element specifies the version of the
                        application used to generate the file.</xsd:documentation>
                </xsd:annotation>
            </xsd:element>
            <xsd:element name="schema_version" type="xsd:decimal" minOccurs="1" maxOccurs="1">
                <xsd:annotation>
                    <xsd:documentation xml:lang="en">The required schema_version element specifies the version of the
                        schema that the document has been written against and that should be used for
                        validation.</xsd:documentation>
                </xsd:annotation>
            </xsd:element>
            <xsd:element name="timestamp" type="xsd:dateTime" minOccurs="1" maxOccurs="1">
                <xsd:annotation>
                    <xsd:documentation xml:lang="en">The required timestamp element specifies when the particular
                        document was compiled. The format for the timestamp is yyyy-mm-ddThh:mm:ss. Note that the
                        timestamp element does not specify when an item in the document was created or modified but
                        rather when the actual XML document that contains the items was created. For example, a document
                        might pull a bunch of existing items together, each of which was created at some point in the
                        past. The timestamp in this case would be when this combined document was
                        created.</xsd:documentation>
                </xsd:annotation>
            </xsd:element>
            <xsd:any minOccurs="0" maxOccurs="unbounded" namespace="##other" processContents="lax"/>
        </xsd:sequence>
    </xsd:complexType>
    <xsd:complexType name="ItemType">
        <xsd:annotation>
            <xsd:documentation xml:lang="en">The ItemType complex type defines an element that represents a single CPE
                Name. The required name attribute is a URI which must be a unique key and should follow the URI
                structure outlined in the CPE Specification. The optional title element is used to provide a
                human-readable title for the platform. To support uses intended for multiple languages, this element
                supports the ‘xml:lang’ attribute. At most one title element can appear for each language. The notes
                element holds optional descriptive material. Multiple notes elements are allowed, but only one per
                language should be used. Note that the language associated with the notes element applies to all child
                note elements. The optional references element holds external info references. The optional check
                element is used to call out an OVAL Definition that can confirm or reject an IT system as an instance of
                the named platform. Additional elements not part of the CPE namespace are allowed and are just skipped
                by validation. In essence, a dictionary file can contain additional information that a user can choose
                to use or not, but this information is not required to be used or understood.</xsd:documentation>
        </xsd:annotation>
        <xsd:sequence>
            <xsd:element name="title" type="cpe_dict:TextType" minOccurs="0" maxOccurs="unbounded"/>
            <xsd:element name="notes" type="cpe_dict:NotesType" minOccurs="0" maxOccurs="unbounded"/>
            <xsd:element name="references" type="cpe_dict:ReferencesType" minOccurs="0" maxOccurs="1"/>
            <xsd:element name="check" type="cpe_dict:CheckType" minOccurs="0" maxOccurs="unbounded"/>
            <xsd:any minOccurs="0" maxOccurs="unbounded" namespace="##other" processContents="lax"/>
        </xsd:sequence>
        <xsd:attribute name="name" type="cpe-name:cpe22Type" use="required"/>
        <xsd:attribute name="deprecated" type="xsd:boolean" use="optional" default="false"/>
        <xsd:attribute name="deprecated_by" type="cpe-name:cpe22Type" use="optional"/>
        <xsd:attribute name="deprecation_date" type="xsd:dateTime" use="optional"/>
    </xsd:complexType>
    <xsd:complexType name="ListType">
        <xsd:annotation>
            <xsd:documentation xml:lang="en">The ListType complex type defines an element that is used to hold a
                collection of individual items. The required generator section provides information about when the
                definition file was compiled and under what version. Additional elements not part of the CPE namespace
                are allowed and are just skipped by validation. In essence, a dictionary file can contain additional
                information that a user can choose to use or not, but this information is not required to be used or
                understood.</xsd:documentation>
        </xsd:annotation>
        <xsd:sequence>
            <xsd:element name="generator" type="cpe_dict:GeneratorType" minOccurs="0" maxOccurs="1"/>
            <xsd:element ref="cpe_dict:cpe-item" minOccurs="1" maxOccurs="unbounded"/>
            <xsd:any minOccurs="0" maxOccurs="unbounded" namespace="##other" processContents="lax"/>
        </xsd:sequence>
    </xsd:complexType>
    <xsd:complexType name="TextType">
        <xsd:annotation>
            <xsd:documentation xml:lang="en">The TextType complex type allows the xml:lang attribute to associate a
                specific language with an element's string content.</xsd:documentation>
        </xsd:annotation>
        <xsd:simpleContent>
            <xsd:extension base="xsd:string">
                <xsd:attribute ref="xml:lang"/>
            </xsd:extension>
        </xsd:simpleContent>
    </xsd:complexType>
    <xsd:complexType name="NotesType">
        <xsd:annotation>
            <xsd:documentation xml:lang="en">The NotesType complex type defines an element that consists of one or more
                child note elements. It is assumed that each of these note elements is representative of the same
                language as defined by their parent.</xsd:documentation>
        </xsd:annotation>
        <xsd:sequence>
            <xsd:element name="note" type="xsd:string" minOccurs="1" maxOccurs="unbounded"/>
        </xsd:sequence>
        <xsd:attribute ref="xml:lang"/>
    </xsd:complexType>
    <xsd:complexType name="ReferencesType">
        <xsd:annotation>
            <xsd:documentation xml:lang="en">The ReferencesType complex type defines an element used to hold a
                collection of individual references. Each reference consists of a piece of text (intended to be
                human-readable) and a URI (intended to be a URL, and point to a real resource) and is used to point to
                extra descriptive material, for example a supplier's web site or platform
                documentation.</xsd:documentation>
        </xsd:annotation>
        <xsd:sequence>
            <xsd:element name="reference" minOccurs="1" maxOccurs="unbounded">
                <xsd:complexType>
                    <xsd:simpleContent>
                        <xsd:extension base="xsd:string">
                            <xsd:attribute name="href" type="xsd:anyURI"/>
                        </xsd:extension>
                    </xsd:simpleContent>
                </xsd:complexType>
            </xsd:element>
        </xsd:sequence>
    </xsd:complexType>
    <xsd:complexType name="CheckType">
        <xsd:annotation>
            <xsd:documentation xml:lang="en">The CheckType complex type is used to define an element to hold information
                about an individual check. It includes a checking system specification URI, string content, and an
                optional external file reference. The checking system specification should be the URI for a particular
                version of OVAL or a related system testing language, and the content will be an identifier of a test
                written in that language. The external file reference could be used to point to the file in which the
                content test identifier is defined.</xsd:documentation>
        </xsd:annotation>
        <xsd:simpleContent>
            <xsd:extension base="xsd:string">
                <xsd:attribute name="system" type="xsd:anyURI" use="required"/>
                <xsd:attribute name="href" type="xsd:anyURI" use="optional"/>
            </xsd:extension>
        </xsd:simpleContent>
    </xsd:complexType>

    <!-- ================================================== -->
    <!-- =====  Change History  -->
    <!-- ================================================== -->
    <!--
        v2.3 - Made title to minOccurs = 0.  Removed namePattern and referencing CPE Naming schema.
    -->

</xsd:schema>