0.3

git-svn-id: file:///home/ksmith/gitmigration/svn/xmpp/trunk@1996 4b5297f7-1745-476d-ba37-a9c6900126ab

xep-0221.xml

@@ -22,6 +22,12 @@
   <shortname>NOT_YET_ASSIGNED</shortname>
   &ianpaterson;
   &stpeter;
+  <revision>
+    <version>0.3</version>
+    <date>2008-06-18</date>
+    <initials>psa</initials>
+    <remark>Changed MUST to SHOULD regarding inclusion of uri element; allowed inclusion of codecs parameter in type attribute per RFC 4281; added Security Considerations section.</remark>
+  </revision>
   <revision>
     <version>0.2</version>
     <date>2008-01-30</date>
@@ -43,14 +49,14 @@
 <section1 topic='Media Element' anchor='media'>
   <p>The root element for media data is &lt;media/&gt;. This element MUST be qualified by the "urn:xmpp:tmp:media-element' namespace &NSNOTE;. The &lt;media/&gt; element MUST be contained within a &lt;field/&gt; element qualified by the 'jabber:x:data' namespace.</p>
   <p>If the media is an image or video then the &lt;media/&gt; element SHOULD include 'height' and 'width' attributes specifying the recommended display size of the media in pixels.</p>
-  <p>The &lt;media/&gt; element MUST contain at least one &lt;uri/&gt; element to specify the out-of-band location of the media data. <note>Constrained execution environments prevent some clients (e.g., Web clients) from rendering media unless it has been received out-of-band.</note> The &lt;uri/&gt; element MUST contain a URI that indicates the location and MUST include a 'type' atribute that specifies the MIME type (see &rfc2045;) of the media.</p>
+  <p>The &lt;media/&gt; element SHOULD contain at least one &lt;uri/&gt; element to specify the out-of-band location of the media data. <note>Constrained execution environments prevent some clients (e.g., Web clients) from rendering media unless it has been received out-of-band.</note> If included, the &lt;uri/&gt; element MUST contain a URI that indicates the location and MUST include a 'type' atribute that specifies the MIME type (see &rfc2045;) of the media. The MIME type SHOULD be as registered in the &ianamedia;. The 'type' attribute MAY include the codecs parameter as specified in &rfc4281;, as shown in the example of the "audio/ogg" media type in the example below.</p>
   <p>The &lt;media/&gt; element MAY also contain one or more &lt;data/&gt; elements for distributing the media in-band. The &lt;data/&gt; element MUST be qualified by the 'urn:xmpp:tmp:data-element' as defined in &xep0231;. The <em>encoded</em> data SHOULD NOT be larger than 8 kilobytes. <note>If a stanza contains more than one &lt;data/&gt; element, the sending entity MUST take care not to trigger server-defined bandwidth limits.</note></p>
   <example caption='Audio Media Element'><![CDATA[
 <media xmlns='urn:xmpp:tmp:media-element'>
   <uri type='audio/x-wav'>
     http://victim.example.com/challenges/speech.wav?F3A6292C
   </uri>
-  <uri type='audio/ogg-speex'>
+  <uri type='audio/ogg; codecs=speex'>
     http://victim.example.com/challenges/speech.ogg?F3A6292C
   </uri>
   <uri type='audio/mpeg'>
@@ -83,6 +89,14 @@
   ]]></example>
 </section1>
 
+<section1 topic='Security Considerations' anchor='security'>
+  <p>The ability to include arbitrary binary data implies that it is possible to send scripts, applets, images, and executable code, which may be potentially harmful. To reduce the risk of such exposure, an implementation MAY choose to not display or process such data but instead either completely ignore the data, show only the value of the 'alt' attribute (if included), or prompt a human user for approval (either explicitly via user action or implicitly via a list of approved entities from whom the user will accept binary data without per-event approval).</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'>
   <section2 topic='Protocol Namespaces' anchor='ns'>
     <p>Until this specification advances to a status of Draft, its associated namespace shall be "urn:xmpp:tmp:media-element"; upon advancement of this specification, the &REGISTRAR; shall issue a permanent namespace in accordance with the process defined in Section 4 of &xep0053;.</p>
@@ -105,7 +119,7 @@
   <xs:element name='media'>
     <xs:complexType>
       <xs:sequence xmlns:data='urn:xmpp:tmp:data-element'>
-        <xs:element ref='uri' minOccurs='1' maxOccurs='unbounded'/>
+        <xs:element ref='uri' minOccurs='0' maxOccurs='unbounded'/>
         <xs:element ref='data:data' minOccurs='0' maxOccurs='unbounded'/>
       </xs:sequence>
       <xs:attribute name='height' type='xs:unsignedShort' use='optional'/>