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878 lines
39 KiB
XML
878 lines
39 KiB
XML
<?xml version='1.0' encoding='UTF-8'?>
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<!DOCTYPE xep SYSTEM 'xep.dtd' [
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<!ENTITY % ents SYSTEM 'xep.ent'>
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<!ENTITY LABEL "<label/>">
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<!ENTITY CATALOG "<catalog/>">
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<!ENTITY SECURITYLABEL "<securitylabel/>">
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<!ENTITY DISPLAYMARKING "<displaymarking/>">
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<!ENTITY EQUIVALENTLABEL "<equivalentlabel/>">
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<!ENTITY HEADLINE "<headline/>">
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<!ENTITY IDENTITY "<identity/>">
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%ents;
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]>
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<?xml-stylesheet type='text/xsl' href='xep.xsl'?>
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<xep>
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<header>
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<title>Security Labels in XMPP</title>
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<abstract>This document describes the use of security labels in XMPP. The document
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specifies how security label metadata is carried in XMPP, when this metadata
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should or should not be provided, and how the metadata is to be processed.</abstract>
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&LEGALNOTICE;
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<number>0258</number>
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<status>Experimental</status>
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<type>Standards Track</type>
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<sig>Standards</sig>
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<approver>Council</approver>
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<dependencies>
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<spec>XMPP Core</spec>
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<spec>XEP-0001</spec>
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</dependencies>
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<supersedes/>
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<supersededby/>
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<shortname>sec-label</shortname>
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<author>
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<firstname>Kurt</firstname>
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<surname>Zeilenga</surname>
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<email>Kurt.Zeilenga@Isode.COM</email>
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<jid>Kurt.Zeilenga@Isode.COM</jid>
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</author>
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<revision>
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<version>0.7</version>
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<date>2011-03-08</date>
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<initials>kdz</initials>
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<remark><p>Illustrate XEP 45 security label room configuration. Make clarifications and minor editorial changes.</p></remark>
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</revision>
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<revision>
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<version>0.6</version>
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<date>2010-07-30</date>
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<initials>kdz</initials>
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<remark><p>Extend catalog handling. Minor editorial changes.</p></remark>
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</revision>
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<revision>
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<version>0.5</version>
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<date>2009-07-27</date>
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<initials>kdz</initials>
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<remark><p>Remove &LABEL;/&EQUIVALENTLABEL; type= attribute. Clarify label catalog discovery. Clarify syntax of selector= attribute.</p></remark>
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</revision>
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<revision>
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<version>0.4</version>
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<date>2009-07-23</date>
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<initials>kdz</initials>
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<remark><p>Update label catalogs to include user input selector.</p></remark>
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</revision>
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<revision>
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<version>0.3</version>
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<date>2009-03-20</date>
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<initials>kdz</initials>
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<remark><p>Add text regarding default bg/fg colors. Correct examples.</p></remark>
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</revision>
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<revision>
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<version>0.2</version>
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<date>2009-03-10</date>
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<initials>kdz</initials>
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<remark><p>Reworked discovery and various updates.</p></remark>
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</revision>
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<revision>
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<version>0.1</version>
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<date>2009-01-05</date>
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<initials>psa</initials>
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<remark><p>Initial published version.</p></remark>
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</revision>
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<revision>
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<version>0.0.081203</version>
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<date>2008-12-03</date>
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<initials>kdz</initials>
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<remark><p>Initial draft.</p></remark>
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</revision>
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</header>
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<section1 topic='Introduction' anchor='intro'>
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<p>A security label, sometimes referred to as a confidentiality label, is
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a structured representation of the sensitivity of a piece of information. A security
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label is used in conjunction with a clearance, a structured representation of what
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information sensitivities a person (or other entity) is authorized to access, and a security
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policy to control access to each piece of information. For instance, message could be
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labeled as "SECRET", and hence requiring the sender and the receiver to each have a
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clearance granting access to "SECRET" information. &X.841; provides a discussion of
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security labels, clearances, and security policy.</p>
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<p>Sensitivity-based authorization is used in networks which operate under a set of
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information classification rules, such as in government agency networks. The
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standardized formats for security labels, clearances, and security policy are
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generalized and do have application in non-government networks.</p>
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<p>This document describes the use of security labels in &xmpp;. The document specifies
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how security label metadata is carried in XMPP. It standardizes a mechanism for
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carrying ESS Security Labels in XMPP, as well as provides for use of other label
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formats. ESS Security Labels are specified in &rfc2634;. ESS Security Labels are
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commonly used in conjunction with &X.500; clearances and either X.841 or &SDN.801c;
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security policies.</p>
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<example caption="Message with ESS Security Label"><![CDATA[
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<message to='romeo@example.net' from='juliet@example.com/balcony'>
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<body>This content is classified.</body>
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<securitylabel xmlns='urn:xmpp:sec-label:0'>
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<displaymarking fgcolor='black' bgcolor='red'>SECRET</displaymarking>
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<label><esssecuritylabel xmlns='urn:xmpp:sec-label:ess:0'>
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MQYCAQQGASk=
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</esssecuritylabel></label>
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</securitylabel>
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</message>
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]]></example>
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<example caption="Message with IC-ISM Label"><![CDATA[
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<message to='romeo@example.net' from='juliet@example.com/balcony'>
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<body>This content is classified.</body>
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<securitylabel xmlns='urn:xmpp:sec-label:0'>
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<displaymarking fgcolor='black' bgcolor='red'>SECRET</displaymarking>
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<label><icismlabel xmlns='http://example.gov/IC-ISM/0' classification='S'
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ownerProducer='USA'/></label>
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</securitylabel>
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</message>
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]]></example>
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<p>Note: The &IC-ISM; label example is for <em>illustrative purposes only</em>.</p>
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<p>The document details when security label metadata should or should not be provided, and how
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this metadata is to be processed.</p>
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<p>This document does not provide:
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<ul>
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<li>any mechanism for a client might discover the security policy
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enforce at its home server, or any other server;</li>
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<li>any mechanism for a client to discover the user's clearance,
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or the clearance of associated with any resource; nor</li>
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<li>any administrative mechanism for a client to configure
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configure policy, clearance, and labels of any resource.</li>
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</ul>
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Such mechanisms may be introduced in subsequent documents.</p>
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<p>This document does discuss how one might securely bind a security label to a stanza.
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It is expected a subsequent document will tackle this topic.</p>
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</section1>
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<section1 topic='Discovering Feature Support' anchor='disco'>
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<p>An entity (client or server) which supports the XMPP Security Label protocol
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MUST report that fact by including a service discovery feature of
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"<tt>urn:xmpp:sec-label:0</tt>" in response to a &xep0030; information request.</p>
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<p>Clients wishing to include a XMPP Security Label element in any stanza they
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generate SHOULD determine if their server supports the XMPP Security Label protocol.
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If their server does not support XMPP Security Label, the client SHOULD NOT generate
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XMPP Security Labels as the server not supporting this protocol will generally
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ignore XMPP Security Labels as they would any other unrecognized element.</p>
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<p>As each service domain may have different support for security labels, servers
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should advertise and clients should perform appropriate discovery lookups on a
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per service basis.</p>
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<example caption="Service Discovery information request"><![CDATA[
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<iq type='get'
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from='user@example.com/Work'
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to='example.com'
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id='disco1'>
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<query xmlns='http://jabber.org/protocol/disco#info'/>
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</iq>
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]]></example>
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<example caption="Service Discovery information response"><![CDATA[
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<iq type='result'
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from='example.com'
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to='user@example.com/Work'
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id='disco1'>
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<query xmlns='http://jabber.org/protocol/disco#info'>
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...
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<feature var='urn:xmpp:sec-label:0'/>
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...
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</query>
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</iq>
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]]></example>
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</section1>
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<section1 topic='Protocol' anchor='protocol'>
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<p>An element, &SECURITYLABEL;, is defined to carry security label metadata. This metadata
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includes a security label, zero or more equivalent security labels, and optionally display
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marking data.</p>
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<example caption="Labeled Message"><![CDATA[
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<message to='romeo@example.net' from='juliet@example.com/balcony'>
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<body>This content is classified.</body>
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<securitylabel xmlns='urn:xmpp:sec-label:0'>
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<displaymarking fgcolor='black' bgcolor='red'>SECRET</displaymarking>
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<label>
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<esssecuritylabel xmlns='urn:xmpp:sec-label:ess:0'
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>MQYCAQIGASk=</esssecuritylabel>
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</label>
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<equivalentlabel>
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<esssecuritylabel xmlns='urn:xmpp:sec-label:ess:0'
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>MRUCAgD9DA9BcXVhIChvYnNvbGV0ZSk=</esssecuritylabel>
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</equivalentlabel>
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</securitylabel>
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</message>
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]]></example>
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<p>The security label metadata is carried in an &SECURITYLABEL; element.
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The &SECURITYLABEL; element which contains one and only one &LABEL; element,
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zero or more &EQUIVALENTLABEL; elements, and an optional &DISPLAYMARKING; element.</p>
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<p>The &LABEL; provides the primary security label. It is commonly issued
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by the sender under the security policy of that they and their home
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server operating under. The &LABEL; contains either a single element
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representing the primary security label or is empty to indicate use of
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a default.</p>
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<p>Each &EQUIVALENTLABEL; represents an equivalent security label under
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other policies. Each &EQUIVALENTLABEL; contains a single element
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representing the equivalent label. This element might be used when
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a recepient is known to hold a clearance under a different policy
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than the sender.</p>
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<p>The &DISPLAYMARKING; element contains a display string for use by
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implementations which are unable to utilize the applicable security policy
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to generate display markings. The element may optionally contain two
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attributes, <tt>fgcolor=</tt> and <tt>bgcolor=</tt>, whose values are HTML
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color strings (e.g., '<tt>red</tt>' or '<tt>#ff0000</tt>'), for use in
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colorizing the display marking. The <tt>fgcolor=</tt> default is <tt>black</tt>.
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The <tt>bgcolor=</tt> default is <tt>white</tt>.
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</p>
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</section1>
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<section1 topic='Label Catalog Discovery' anchor='label-catalog'>
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<p>A client can request a catalog for a particular JID by sending
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a catalog discovery request to the client's server. Where the JID
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is hosted by some other server, the client's server is expected to
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produce a suitable catalog (or fail the request). The client's server
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may, as needed, query catalogs from other servers in order to
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fulfill the client's request.</p>
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<p>While this specification does not preclude a client from directing
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a catalog request elsewhere, it is noted that catalog returned by
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a party other than its server may not be directly useable by the
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client. For instance, the client's server might require a particular
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only-locally-known label be used in messages to a particular remote
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JID.</p>
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<p>It is RECOMMENDED the server publish catalogs of security label
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for use by clients.</p>
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<p>If catalog is restrictive, as indicated by the restrict attribute
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with value of true, the client SHOULD use one of the labels
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(or no label) offered by the catalog.</p>
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<p>One and only one of the items may have a default attribute with
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value of true. The client should default the label selection to
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this item in cases where the user has not selected an item.</p>
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<p>An item may have no label. Such an item offers a choice of
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sending a stanza without a label.</p>
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<p>Each catalog provided should only contain labels for which the client
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is allowed to use (based upon the user's authorization) in a particular
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context (such as in chatroom). A catalog may not be include the
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complete set of labels available for the use by the client in the
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context.</p>
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<blockquote>Note: the single catalog per context approach used here
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is likely inadequate in enviroments where there are a large number
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of labels in use. It is expected that a more sophisticated approach
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will be introduced in a subsequent revision of this
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specification.</blockquote>
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<p>As each service domain may have different support for security labels,
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servers should advertise and clients should perform appropriate
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discovery lookups on a per service basis.</p>
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<p>To indicate the support for label catalog discovery, a server
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advertises the <tt>urn:xmpp:sec-label:catalog:2</tt> feature.
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The following pair of examples illustrates this feature discovery.</p>
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<p>Items in the catalog may contain a selector attribute. The
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value of this attribute represents the item's placement in a
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hierarchical organization of the items. If one item has a selector
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attribute, all items should have a selector item. The value of the selector
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attribute conforms to the selector-value ABNF production:
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<blockquote>
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<![CDATA[
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selector-value = (<item>"|")*<item>
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]]>
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</blockquote>
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</p>
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<p>where <item> is a sequence of characters not including "|".</p>
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<p>A value of "X|Y|Z" indicates that this item is "Z" in the
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the "Y" subset of the "X" subset of items. This information may
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be used, for instance, in generating label selection menus in
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graphical user interfaces.</p>
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<blockquote>Note: use of unnecessarily deep hierarchies should be
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avoided.</blockquote>
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<example caption="Label Catalog Feature Discovery request"><![CDATA[
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<iq type='get'
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to='example.com'
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from='user@example.com/Work'
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id='disco1'>
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<query xmlns='http://jabber.org/protocol/disco#info'/>
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</iq>
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]]></example>
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<example caption="Label Information Feature Discovery response"><![CDATA[
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<iq type='result'
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from='example.com'
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to='user@example.com/Work'
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id='disco1'>
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<query xmlns='http://jabber.org/protocol/disco#info'>
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...
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<feature var='urn:xmpp:sec-label:catalog:2'/>
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...
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</query>
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</iq>
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]]></example>
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<p>The following example pair illustrates catalog discovery. Note that client directs the &IQ; to its server regardless of which catalog it requests (via the to= attribute of in &CATALOG; element).</p>
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<example caption="Label Catalog request"><![CDATA[
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<iq to='example.com' type='get' id='cat1'>
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<catalog xmlns='urn:xmpp:sec-label:catalog:2' to='example.com'/>
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</iq>
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]]></example>
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<example caption="Label Catalog Get response"><![CDATA[
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<iq type='result' to='user@example.com/Work' id='cat1'>
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<catalog xmlns='urn:xmpp:sec-label:catalog:2'
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to='example.com' name='Default'
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desc='an example set of labels'
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restrict='false'>
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<item selector="Classified|SECRET">
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<securitylabel xmlns='urn:xmpp:sec-label:0'>
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<displaymarking fgcolor='black' bgcolor='red'>SECRET</displaymarking>
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<label>
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<esssecuritylabel xmlns='urn:xmpp:sec-label:ess:0'
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>MQYCAQQGASk=</esssecuritylabel>
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</label>
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</securitylabel>
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</item>
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<item selector="Classified|CONFIDENTIAL">
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<securitylabel xmlns='urn:xmpp:sec-label:0'>
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<displaymarking fgcolor='black' bgcolor='navy'>CONFIDENTIAL</displaymarking>
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<label>
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<esssecuritylabel xmlns='urn:xmpp:sec-label:ess:0'
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>MQYCAQMGASk</esssecuritylabel>
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</label>
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</securitylabel>
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</item>
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<item selector="Classified|RESTRICTED">
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<securitylabel xmlns='urn:xmpp:sec-label:0'>
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<displaymarking fgcolor='black' bgcolor='aqua'>RESTRICTED</displaymarking>
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<label>
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<esssecuritylabel xmlns='urn:xmpp:sec-label:ess:0'
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>MQYCAQIGASk=</esssecuritylabel>
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</label>
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</securitylabel>
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</item>
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<item selector="UNCLASSIFIED" default="true"/>
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</catalog>
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</iq>
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]]></example>
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</section1>
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<section1 topic='Use in XMPP' anchor='xmpp-use'>
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<p>The sensitivity-based access control decisions discussed herein are to be
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made independently of other access control decisions or other facilities.
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That is, the sensitivity-based access control decisions are not conditional
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on other factors.</p>
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<p>It is intended that &SECURITYLABEL; elements are only used as prescribed by
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this document, or other formal specifications. Any other use of
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&SECURITYLABEL; SHOULD be viewed as a protocol violation. The stanza SHOULD
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be discarded with, if approrpriate, an error response. Such error responses
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SHOULD NOT include content from the violating stanza, excepting that
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necessary to well-formed error responses.</p>
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<p>When use of a &SECURITYLABEL; element is prescribed, that use is RECOMMENDED.
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Absence of a &SECURITYLABEL; element implies the stanza has the default label
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as specified in the governing security policy. Given that the governing
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policy may not specify a default label, hence denying access to the stanza,
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supporting clients SHOULD provide a &SECURITYLABEL; element where prescribed.</p>
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<p>Typically, a client would allow the user to choose populate the
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&SECURITYLABEL; from one of from a small set of security labels selections
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known to it (through configuration and/or discovery and/or other means),
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such as from a pull-down menu. That selection would include appropriate
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values for the &LABEL;, &DISPLAYMARKING;, and &EQUIVALENTLABEL; elements.</p>
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<p>A policy-aware client may provide the user with an interface allowing the
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user to produce custom labeling data for inclusion in this set. A
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policy-aware client SHOULD preclude the user from producing &LABEL; values
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which the user's own clearance does not grant access to, and SHOULD preclude
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sending any label which the user's own clearance does not grant access to.
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Each &EQUIVALENTLABEL; value, if any, MUST be equivalent under an equivalent
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policy to the &LABEL;. The &DISPLAYMARKING; element SHOULD be set the
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display marking prescribed for the &LABEL; under the governing policy, or,
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if the governing policy prescribes no display marking for the &LABEL;,
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absent.</p>
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<p>A client which receives a stanza with &SECURITYLABEL; element is to promiently
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display the &DISPLAYMARKING; value. A policy-aware may alternatively
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promiently display the marking for the &LABEL; prescribed by the governing
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policy.</p>
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<p>Each server is expected to make a number of sensitivity-based authorization
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decisions. Each decision is made by evaluating an Access Control Decision
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Function (ACDF) with a governing policy, a clearance, and a security label.
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The ACDF yields either <em>Grant</em> or <em>Deny</em>.</p>
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<p>If the user holds a valid clearance (known to the server) under the
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governing policy, the clearance input is the user's clearance. Otherwise,
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if the governing policy provides a default clearance, the clearance input
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is the default clearance. Otherwise, the clearance input is the nil clearance.
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The nil clearance is a clearance for which the ACDF always returns Deny when
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given as the clearance input.</p>
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<p>If the stanza contains a &SECURITYLABEL; element and the either the &LABEL;
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element or one of the &EQUIVALENTLABEL; elements contain an appropriate label,
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that label input is that label. Otherwise, the label input is the default
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label provided the governing policy or, if no default label is provided,
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the nil label. The nil label is a label for which the ACDF always returns
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Deny when given as the label input.</p>
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<p>The term "effective clearance" and "effective label" refer, respectively,
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to the clearance and label provided as input to the ACDF.</p>
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<p>Not all sensitivity-based authorization decisions an XMPP server might make
|
|
involve a user clearance and/or stanza label. A server may only provide
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service to users which hold an appropriate clearance as determined by calling
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the ACDF with the user's clearance and a label associated with the service.
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|
A clearance might also be associated with the service to restrict the set
|
|
of labels may be used in labeling stanzas. Labels and clearances can also
|
|
be associated with network interfaces, remote servers, chatrooms, pubsub
|
|
nodes.</p>
|
|
<section2 topic='Use in Instant Messaging' anchor='im-use'>
|
|
<p>A client may provide a &SECURITYLABEL; element in any &MESSAGE; it sends.</p>
|
|
<!--
|
|
<p>The server will make, at a minimum, the following accessing control decisions:
|
|
<ul>
|
|
<li>TBD</li>
|
|
</ul>
|
|
</p>
|
|
-->
|
|
</section2>
|
|
<section2 topic='Use in Group Chat and Multi-User Chat' anchor='muc-use'>
|
|
<p>A client may provide a &SECURITYLABEL; element in &MESSAGE; stanzas.</p>
|
|
|
|
<section3 topic='Discovery' anchor='muc-disco'>
|
|
<p>A server SHOULD provide a label feature and information discovery for the room.</p>
|
|
<p>Clients SHOULD discover label feature and information on a per room basis.</p>
|
|
</section3>
|
|
<section3 topic='Sending Messages' anchor='muc-send'>
|
|
<p>Sending groupchat messages is similiar to sending normal messages, however
|
|
their are a few differences.</p>
|
|
<p>Groupchat messages are addressed to the room. The room clearance must
|
|
be suitable for the message label, else it should be rejected.</p>
|
|
<p>The room's clearance may allow a variety of labels to be used. Not all
|
|
partipants may be cleared for all labels allowed in the room. The server
|
|
MUST only deliver messages to partipants for which they are cleared to
|
|
receive.</p>
|
|
</section3>
|
|
<section3 topic='Private Messages' anchor='muc-private'>
|
|
<p>Private messages are treated as discussed in the "Use in Instant Messaging"
|
|
section. (Should private messages be restricted by room's configuration?)</p>
|
|
</section3>
|
|
<section3 topic='Invitations' anchor='muc-invite'>
|
|
<p>Invitations may be labeled.</p>
|
|
</section3>
|
|
<section3 topic='Changing Subject' anchor='muc-subject'>
|
|
<p>This section discusses semantics of &SECURITYLABEL; elements contained
|
|
in &MESSAGE; stanzas containing a &SUBJECT; element.</p>
|
|
<p>The presence of a &SECURITYLABEL; element indicates a request to change
|
|
the room's label, either to the provided label or, if the element is empty,
|
|
to unset the room's label. The server is to refuse the request if the
|
|
requestor is not authorized to change the subject, not cleared for the
|
|
requested label, or if the server is otherwise unwilling or unable to make
|
|
the change. If the label change is refused, so must the accompanied
|
|
subject change. Likewise, if the subject change is refused, so must the
|
|
accompanied label change.</p>
|
|
<p>Upon change of the room's label, the server MUST immediately kick
|
|
all members whom are not cleared for that label out of the room.</p>
|
|
<p>In absence of a &SECURITYLABEL; element, the label associated with the
|
|
room is unchanged.</p>
|
|
<p>The room's label can also be changed through room configuration (to be
|
|
discussed in later revision of this document).</p>
|
|
</section3>
|
|
<section3 topic='Room Configuration' anchor='muc-config'>
|
|
<p>The server may allow for configuration of security label parameters
|
|
via room configuration mechanisms. The approach is intended to be
|
|
ad-hoc. Hence this section is intended to be illustrative of one
|
|
possible approach. Implementations are free to utilize other
|
|
approaches.</p>
|
|
<example caption="Room Configuration Form"><![CDATA[
|
|
<iq from='room@muc.example.com'
|
|
id='create1'
|
|
to='user@example.com/Work'
|
|
type='result'>
|
|
<query xmlns='http://jabber.org/protocol/muc#owner'>
|
|
<x xmlns='jabber:x:data' type='form'>
|
|
<title>"darkcave" room configuration</title>
|
|
...
|
|
<field label='Room Label' type='list-single' var='sec-label#label'>
|
|
<value>Catalog:UNCLASSIFIED</value>
|
|
<option label='SECRET'><value>Catalog:SECRET</value></option>
|
|
<option label='CONFIDENTIAL'><value>Catalog:CONFIDENTIAL</value></option>
|
|
<option label='UNCLASSIFED'><value>Catalog:UNCLASSIFIED</value></option>
|
|
<option label='Custom'><value>Custom</value></option>
|
|
</field>
|
|
<field label='Custom Room Label' type='text-single'
|
|
var='sec-label#custom-label'/>
|
|
|
|
<field label='Room Allowed Markings' type='list-multi' var='sec-label#clearance'>
|
|
<value>Catalog:UNCLASSIFIED</value>
|
|
<option label='SECRET'><value>Catalog:SECRET</value></option>
|
|
<option label='CONFIDENTIAL'><value>Catalog:CONFIDENTIAL</value></option>
|
|
<option label='UNCLASSIFED'><value>Catalog:UNCLASSIFIED</value></option>
|
|
<option label='Custom'><value>Custom</value></option>
|
|
</field>
|
|
<field label='Custom Room Clearance' type='text-single'
|
|
var='sec-label#custom-clearance'/>
|
|
</x>
|
|
</query>
|
|
</iq>
|
|
]]></example>
|
|
<p>In the above example, the server allows the room label to be set to one of
|
|
to a subset of labels from the label catalog (see below), using the display
|
|
name for selection, as well as custom label support. For custom label choice
|
|
support, the server offers an single text box for entry of an appropriate
|
|
text string indicating the label to use. Likewise for the room clearance
|
|
and default room clearance.</p>
|
|
<p>Though offering choices from the label catalog is often desirable,
|
|
a server could only offer custom label and/or clearance support.</p>
|
|
<example caption="Room Configuration Form"><![CDATA[
|
|
<iq from='room@muc.example.com'
|
|
id='create1'
|
|
to='user@example.com/Work'
|
|
type='result'>
|
|
<query xmlns='http://jabber.org/protocol/muc#owner'>
|
|
<x xmlns='jabber:x:data' type='form'>
|
|
<title>"darkcave" room configuration</title>
|
|
...
|
|
<field label='Room Label' type='text-single'
|
|
var='sec-label#custom-label'/>
|
|
<field label='Room Clearance' type='text-single'
|
|
var='sec-label#custom-clearance'/>
|
|
</x>
|
|
</query>
|
|
</iq>
|
|
]]></example>
|
|
</section3>
|
|
</section2>
|
|
<section2 topic='Use in Presence' anchor='presence-use'>
|
|
<p>&SECURITYLABEL; elements are not to appear in &PRESENCE; stanzas. Server
|
|
SHALL treat any &PRESENCE; stanza that contains a &SECURITYLABEL; as a
|
|
protocol violation.</p>
|
|
<p>Presence information is subject to sensitivity-base authorization decisions,
|
|
however these decisions are made are made using a label associated with the
|
|
presence resource, such as a chatroom's label.</p>
|
|
</section2>
|
|
<section2 topic='Use in PubSub' anchor='pubsub-use'>
|
|
<section3 topic='Discovery' anchor='pubsub-disco'>
|
|
<p>A server SHOULD provide a label feature and information discovery for each node.</p>
|
|
<p>Clients SHOULD discover label feature and information on a per node basis.</p>
|
|
</section3>
|
|
<section3 topic='Publishing items with Security Labels' anchor='muc-send'>
|
|
<p>Each item may be individually labeled.</p>
|
|
<example caption="Publishing with a Security Label"><![CDATA[
|
|
<iq type='set'
|
|
from='hamlet@denmark.lit/blogbot'
|
|
to='pubsub.shakespeare.lit'
|
|
id='pub1'>
|
|
<pubsub xmlns='http://jabber.org/protocol/pubsub'>
|
|
<publish node='princely_musings'>
|
|
<item>
|
|
<entry xmlns='http://www.w3.org/2005/Atom'>
|
|
<title>Soliloquy</title>
|
|
<summary>
|
|
To be, or not to be: that is the question:
|
|
Whether 'tis nobler in the mind to suffer
|
|
The slings and arrows of outrageous fortune,
|
|
Or to take arms against a sea of troubles,
|
|
And by opposing end them?
|
|
</summary>
|
|
<link rel='alternate' type='text/html'
|
|
href='http://denmark.lit/2003/12/13/atom03'/>
|
|
<id>tag:denmark.lit,2003:entry-32397</id>
|
|
<published>2003-12-13T18:30:02Z</published>
|
|
<updated>2003-12-13T18:30:02Z</updated>
|
|
</entry>
|
|
<securitylabel xmlns='urn:xmpp:sec-label:0'>
|
|
<displaymarking fgcolor='black' bgcolor='green'>UNCLASSIFIED</displaymarking>
|
|
<label>
|
|
<esssecuritylabel xmlns='urn:xmpp:sec-label:ess:0'>MQMGASk=</esssecuritylabel>
|
|
</label>
|
|
</securitylabel>
|
|
</item>
|
|
</publish>
|
|
</pubsub>
|
|
</iq>
|
|
]]></example>
|
|
<p>The service then notifies appropriately cleared subscribers.</p>
|
|
<example caption="Publishing with a Security Label"><![CDATA[
|
|
<message from='pubsub.shakespeare.lit' to='francisco@denmark.lit' id='foo'>
|
|
<event xmlns='http://jabber.org/protocol/pubsub#event'>
|
|
<items node=princely_musings'>
|
|
<item id='ae890ac52d0df67ed7cfdf51b644e901'>
|
|
<entry xmlns='http://www.w3.org/2005/Atom'>
|
|
<title>Soliloquy</title>
|
|
<summary>
|
|
To be, or not to be: that is the question:
|
|
Whether 'tis nobler in the mind to suffer
|
|
The slings and arrows of outrageous fortune,
|
|
Or to take arms against a sea of troubles,
|
|
And by opposing end them?
|
|
</summary>
|
|
<link rel='alternate' type='text/html'
|
|
href='http://denmark.lit/2003/12/13/atom03'/>
|
|
<id>tag:denmark.lit,2003:entry-32397</id>
|
|
<published>2003-12-13T18:30:02Z</published>
|
|
<updated>2003-12-13T18:30:02Z</updated>
|
|
</entry>
|
|
<securitylabel xmlns='urn:xmpp:sec-label:0'>
|
|
<displaymarking fgcolor='black' bgcolor='green'>UNCLASSIFIED</displaymarking>
|
|
<label>
|
|
<esssecuritylabel xmlns='urn:xmpp:sec-label:ess:0'>MQMGASk=</esssecuritylabel>
|
|
</label>
|
|
</securitylabel>
|
|
</item>
|
|
</items>
|
|
</event>
|
|
</iq>
|
|
]]></example>
|
|
</section3>
|
|
</section2>
|
|
</section1>
|
|
|
|
<section1 topic='Extension Considerations' anchor='exts'>
|
|
<p>
|
|
This extension is itself is extensible. In particular, the &LABEL; and &EQUIVALENTLABEL;
|
|
elements are designed to hold a range of security labels formats. XML namespaces SHOULD
|
|
be used to avoid name clashes.
|
|
</p>
|
|
</section1>
|
|
|
|
<!--
|
|
<section1 topic='Implementation Notes' anchor='impl'>
|
|
<p>OPTIONAL.</p>
|
|
</section1>
|
|
-->
|
|
<section1 topic='Security Considerations' anchor='security'>
|
|
<p>This document is all about authorization, a key aspect of security. Hence,
|
|
security considerations are discussed through this document.</p>
|
|
<p>Certain XMPP stanzas, such as &PRESENCE; stanzas, are not themselves subject
|
|
to any sensitity-based authorization decisions, and may be forwarded throughout
|
|
the XMPP network. The content of these stanzas should not contain information
|
|
requiring sensitivity-based dissemination controls.</p>
|
|
<p>It is desirable to securely bind the security label to the object it labels.
|
|
This may be accomplished through use of digital signatures. Specification of such
|
|
is left to a future document.
|
|
</p>
|
|
</section1>
|
|
<section1 topic='IANA Considerations' anchor='iana'>
|
|
<p>This document requires no interaction with &IANA;.</p>
|
|
</section1>
|
|
<section1 topic='XMPP Registrar Considerations' anchor='registrar'>
|
|
<p>It is requested the ®ISTRAR; add the extension's namespaces
|
|
and schemas to appropriate XMPP registries.</p>
|
|
</section1>
|
|
<section1 topic='XML Schemas' anchor='schema'>
|
|
<section2 topic='Extension Schema' anchor='schema-sl'>
|
|
<p>
|
|
<code><![CDATA[
|
|
<?xml version='1.0' encoding='UTF-8'?>
|
|
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema" targetNamespace="urn:xmpp:sec-label:0"
|
|
xmlns="urn:xmpp:sec-label:0" elementFormDefault="qualified">
|
|
|
|
<xs:annotation>
|
|
<xs:documentation>The protocol documented by this schema is defined in XEP-0258:
|
|
http://www.xmpp.org/extensions/xep-0258.html</xs:documentation>
|
|
</xs:annotation>
|
|
|
|
<xs:simpleType name="colorCSS">
|
|
<xs:annotation>
|
|
<xs:documentation>CSS colors (W3C colors + "orange")</xs:documentation>
|
|
</xs:annotation>
|
|
<xs:restriction base="xs:string">
|
|
<xs:enumeration value="aqua"/>
|
|
<xs:enumeration value="black"/>
|
|
<xs:enumeration value="blue"/>
|
|
<xs:enumeration value="fuschia"/>
|
|
<xs:enumeration value="gray"/>
|
|
<xs:enumeration value="green"/>
|
|
<xs:enumeration value="lime"/>
|
|
<xs:enumeration value="maroon"/>
|
|
<xs:enumeration value="navy"/>
|
|
<xs:enumeration value="olive"/>
|
|
<xs:enumeration value="purple"/>
|
|
<xs:enumeration value="red"/>
|
|
<xs:enumeration value="silver"/>
|
|
<xs:enumeration value="teal"/>
|
|
<xs:enumeration value="white"/>
|
|
<xs:enumeration value="yellow"/>
|
|
<xs:enumeration value="orange"/>
|
|
</xs:restriction>
|
|
</xs:simpleType>
|
|
|
|
<xs:simpleType name="colorRGB">
|
|
<xs:annotation>
|
|
<xs:documentation>Hex encoded RGB</xs:documentation>
|
|
</xs:annotation>
|
|
<xs:restriction base="xs:string">
|
|
<xs:pattern value="#[0-9A-Fa-f]{6}"/>
|
|
</xs:restriction>
|
|
</xs:simpleType>
|
|
|
|
<xs:simpleType name="color">
|
|
<xs:annotation>
|
|
<xs:documentation>Color</xs:documentation>
|
|
</xs:annotation>
|
|
<xs:union memberTypes="colorCSS colorRGB"/>
|
|
</xs:simpleType>
|
|
|
|
<xs:complexType name="displaymarking">
|
|
<xs:annotation>
|
|
<xs:documentation>Display Marking</xs:documentation>
|
|
<xs:documentation>String to be prominently displayed along with labeled
|
|
object.</xs:documentation>
|
|
</xs:annotation>
|
|
<xs:simpleContent>
|
|
<xs:extension base="xs:string">
|
|
<xs:attribute name="bgcolor" type="color" use="optional" default="white"/>
|
|
<xs:attribute name="fgcolor" type="color" use="optional" default="black"/>
|
|
</xs:extension>
|
|
</xs:simpleContent>
|
|
</xs:complexType>
|
|
|
|
<xs:complexType name="label">
|
|
<xs:choice minOccurs="0">
|
|
<xs:any namespace="##other" processContents="lax"/>
|
|
</xs:choice>
|
|
</xs:complexType>
|
|
|
|
<xs:element name="securitylabel">
|
|
<xs:annotation>
|
|
<xs:documentation>A Security Label</xs:documentation>
|
|
</xs:annotation>
|
|
<xs:complexType>
|
|
<xs:sequence>
|
|
<xs:element name="displaymarking" type="displaymarking">
|
|
<xs:annotation>
|
|
<xs:documentation>A Display Marking</xs:documentation>
|
|
<xs:documentation>To be prominently displayed</xs:documentation>
|
|
</xs:annotation>
|
|
</xs:element>
|
|
<xs:element name="label" type="label">
|
|
<xs:annotation>
|
|
<xs:documentation>The Primary Label</xs:documentation>
|
|
</xs:annotation>
|
|
</xs:element>
|
|
<xs:element name="equivalentlabel" type="label" minOccurs="0" maxOccurs="unbounded">
|
|
<xs:annotation>
|
|
<xs:documentation>An Equivalent Label</xs:documentation>
|
|
</xs:annotation>
|
|
</xs:element>
|
|
</xs:sequence>
|
|
</xs:complexType>
|
|
</xs:element>
|
|
</xs:schema>
|
|
]]></code>
|
|
|
|
A copy of this schema is available at
|
|
<link url='http://www.xmpp.org/schemas/sec-label.xsd'>
|
|
http://www.xmpp.org/schemas/sec-label.xsd</link>.
|
|
</p>
|
|
</section2>
|
|
<section2 topic='<catalog/> schema' anchor='schema-catalog'>
|
|
<p>
|
|
<code><![CDATA[
|
|
<?xml version="1.0" encoding="UTF-8"?>
|
|
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:sl="urn:xmpp:sec-label:0"
|
|
xmlns="urn:xmpp:sec-label:catalog:2" targetNamespace="urn:xmpp:sec-label:catalog:1"
|
|
elementFormDefault="qualified">
|
|
|
|
<xs:annotation>
|
|
<xs:documentation>The protocol documented by this schema is defined in XEP-0258:
|
|
http://www.xmpp.org/extensions/xep-0258.html</xs:documentation>
|
|
</xs:annotation>
|
|
|
|
<xs:import schemaLocation="xep258.xsd" namespace="urn:xmpp:sec-label:0"/>
|
|
|
|
<xs:attribute name="to" type="xs:string">
|
|
<xs:annotation>
|
|
<xs:documentation>Target JabberId</xs:documentation>
|
|
</xs:annotation>
|
|
</xs:attribute>
|
|
|
|
<xs:attribute name="name" type="xs:string">
|
|
<xs:annotation>
|
|
<xs:documentation>Name</xs:documentation>
|
|
</xs:annotation>
|
|
</xs:attribute>
|
|
|
|
<xs:attribute name="desc" type="xs:string">
|
|
<xs:annotation>
|
|
<xs:documentation>Description</xs:documentation>
|
|
</xs:annotation>
|
|
</xs:attribute>
|
|
|
|
<xs:attribute name="id" type="xs:string">
|
|
<xs:annotation>
|
|
<xs:documentation>Identifer for current revision, commonly a hash</xs:documentation>
|
|
</xs:annotation>
|
|
</xs:attribute>
|
|
|
|
<xs:attribute name="size" type="xs:integer">
|
|
<xs:annotation>
|
|
<xs:documentation>Number of items</xs:documentation>
|
|
</xs:annotation>
|
|
</xs:attribute>
|
|
|
|
<xs:attribute name="restrict" type="xs:boolean">
|
|
<xs:annotation>
|
|
<xs:documentation>Restrictive</xs:documentation>
|
|
</xs:annotation>
|
|
</xs:attribute>
|
|
|
|
<xs:attribute name="selector" type="xs:string">
|
|
<xs:annotation>
|
|
<xs:documentation>User input selector</xs:documentation>
|
|
</xs:annotation>
|
|
</xs:attribute>
|
|
|
|
<xs:attribute name="default" type="xs:boolean">
|
|
<xs:annotation>
|
|
<xs:documentation>default selection</xs:documentation>
|
|
</xs:annotation>
|
|
</xs:attribute>
|
|
|
|
<xs:element name="catalog">
|
|
<xs:annotation>
|
|
<xs:documentation>A Catalog of Labels</xs:documentation>
|
|
</xs:annotation>
|
|
|
|
<xs:complexType>
|
|
<xs:sequence>
|
|
<xs:element name="item" minOccurs="0" maxOccurs="unbounded">
|
|
<xs:complexType>
|
|
<xs:sequence>
|
|
<xs:element ref="sl:securitylabel"/>
|
|
</xs:sequence>
|
|
<xs:attribute ref="selector" use="optional"/>
|
|
<xs:attribute ref="default" use="optional"/>
|
|
</xs:complexType>
|
|
</xs:element>
|
|
</xs:sequence>
|
|
<xs:attribute ref="to" use="optional"/>
|
|
<xs:attribute ref="name" use="optional"/>
|
|
<xs:attribute ref="desc" use="optional"/>
|
|
<xs:attribute ref="id" use="optional"/>
|
|
<xs:attribute ref="size" use="optional"/>
|
|
<xs:attribute ref="restrict" use="optional"/>
|
|
</xs:complexType>
|
|
</xs:element>
|
|
</xs:schema>
|
|
]]></code>
|
|
|
|
A copy of this schema is available at
|
|
<link url='http://www.xmpp.org/schemas/sec-label-catalog.xsd'>
|
|
http://www.xmpp.org/schemas/sec-label-catalog.xsd</link>.
|
|
</p>
|
|
</section2>
|
|
<section2 topic='<esssecuritylabel/> schema' anchor='schema-ess'>
|
|
<p>
|
|
<code><![CDATA[
|
|
<?xml version="1.0" encoding="UTF-8"?>
|
|
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema" targetNamespace="urn:xmpp:sec-label:ess:0"
|
|
xmlns="urn:xmpp:sec-label:ess:0" elementFormDefault="qualified">
|
|
<xs:annotation>
|
|
<xs:documentation> The protocol documented by this schema is defined in XEP-0258:
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|
http://www.xmpp.org/extensions/xep-0258.html </xs:documentation>
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</xs:annotation>
|
|
<xs:element name="esssecuritylabel" type="xs:base64Binary">
|
|
<xs:annotation>
|
|
<xs:documentation>An S/MIME ESS SecurityLabel [RFC2634]</xs:documentation>
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|
<xs:documentation>Value is the base64 encoding of the BER/DER encoding of an ASN.1
|
|
ESSSecurityLabel type as defined in RFC 2634. </xs:documentation>
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|
</xs:annotation>
|
|
</xs:element>
|
|
</xs:schema>
|
|
]]></code>
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|
|
|
A copy of this schema is available at
|
|
<link url='http://www.xmpp.org/schemas/sec-label-ess.xsd'>
|
|
http://www.xmpp.org/schemas/sec-label-ess.xsd</link>.
|
|
</p>
|
|
</section2>
|
|
</section1>
|
|
</xep>
|