0.0.2

inbox/hashes.xml

@@ -21,6 +21,14 @@
   <supersededby/>
   <shortname>N/A</shortname>
   &stpeter;
+  &mwild;
+  &ksmith;
+  <revision>
+    <version>0.0.2</version>
+    <date>2011-06-22</date>
+    <initials>mw/ks/psa</initials>
+    <remark><p>Adjusted format to include multiple hashes in one element; modified namespace versioning rules to align with common practice; added service discovery features for various algorithms.</p></remark>
+  </revision>
   <revision>
     <version>0.0.1</version>
     <date>2011-06-16</date>
@@ -42,20 +50,23 @@
   </dl>
 </section1>
 
-<section1 topic='XML Element' anchor='element'>
-  <p>This document defines a new XML element that can be used in any XMPP protocol extension. An example follows.</p>
+<section1 topic='XML Format' anchor='format'>
+  <p>This document defines a new XML element (and child elements) that can be used in any XMPP protocol extension. An example follows.</p>
   <code><![CDATA[
-<hash xmlns='urn:xmpp:hashes:0' algo='sha-256'>
-  2XarmwTlNxDAMkvymloX3S5+VbylNrJt/l5QyPa+YoU=
-</hash>
+<hashes xmlns='urn:xmpp:hashes:0'>
+  <hash algo='sha-256'>2XarmwTlNxDAMkvymloX3S5+VbylNrJt/l5QyPa+YoU=</hash>
+</hashes>
+  ]]></code>
+  <p>The &lt;hashes/&gt; element MAY contain more than one &lt;hash/&gt; child, as in the following example.</p>
+  <code><![CDATA[
+<hashes xmlns='urn:xmpp:hashes:0'>
+  <hash algo='sha-1'>2AfMGH8O7UNPTvUVAM9aK13mpCY=</hash>
+  <hash algo='sha-256'>2XarmwTlNxDAMkvymloX3S5+VbylNrJt/l5QyPa+YoU=</hash>
+</hashes>
   ]]></code>
   <p>The value of the 'algo' attribute MUST be one of the values from the &ianahashes; maintained by &IANA;.</p>
 </section1>
 
-<section1 topic='Namespace Versioning' anchor='versioning'>
-  <p>This document defines the XML namespace 'urn:xmpp:hashes:0'. The document MUST be updated, and the namespace version MUST be incremented, whenever the XSF wishes to modify the list of mandatory, recommended, deprecated, and obsolete algorithms.</p>
-</section1>
-
 <section1 topic='Hash Functions' anchor='hashes'>
   <section2 topic='MD2' anchor='hashes-md2'>
     <p>The MD2 algorithm is not used in any XMPP protocols and has been deprecated by the IETF (see &rfc6149;).</p>
@@ -116,6 +127,32 @@
   <p>These recommendations ought to be reviewed yearly by the &COUNCIL;.</p>
 </section1>
 
+<section1 topic='Determining Support' anchor='disco'>
+  <p>If an entity supports the protocol defined herein, it MUST report that by including a &xep0030; feature of "urn:xmpp:hashes:0" in response to disco#info requests, along with one service discovery feature for each algorithm it supports:</p>
+  <example caption="Service discovery information request"><![CDATA[
+<iq from='romeo@montague.lit/orchard'
+    id='uw72g176'
+    to='juliet@capulet.lit/balcony'
+    type='get'>
+  <query xmlns='http://jabber.org/protocol/disco#info'/>
+</iq>
+  ]]></example>
+  <example caption="Service discovery information response"><![CDATA[
+<iq from='juliet@capulet.lit/balcony'
+    id='uw72g176'
+    to='romeo@montague.lit/orchard'
+    type='result'>
+  <query xmlns='http://jabber.org/protocol/disco#info'>
+    <feature var='urn:xmpp:hashes:0'/>
+    <feature var='urn:xmpp:hash-function-textual-names:md5'/>
+    <feature var='urn:xmpp:hash-function-textual-names:sha-1'/>
+    <feature var='urn:xmpp:hash-function-textual-names:sha-256'/>
+  </query>
+</iq>
+  ]]></example>
+  <p>In order for an application to determine whether an entity supports this protocol, where possible it SHOULD use the dynamic, presence-based profile of service discovery defined in &xep0115;. However, if an application has not received entity capabilities information from an entity, it SHOULD use explicit service discovery instead.</p>
+</section1>
+
 <section1 topic='Security Considerations' anchor='security'>
   <p>This entire document discusses security.</p>
 </section1>
@@ -125,9 +162,54 @@
 </section1>
 
 <section1 topic='XMPP Registrar Considerations' anchor='registrar'>
-  <p>This document requires no interaction with the &REGISTRAR;.</p>
+  <section2 topic='Protocol Namespaces' anchor='registrar-ns'>
+    <p>This specification defines the following XML namespace:</p>
+    <ul>
+      <li>urn:xmpp:hashes:0</li>
+    </ul>
+    <p>The &REGISTRAR; shall include the foregoing namespace in its registry at &NAMESPACES;, as governed by &xep0053;.</p>
+  </section2>
+  <section2 topic='Protocol Versioning' anchor='registrar-versioning'>
+    &NSVER;
+  </section2>
+  <section2 topic='Service Discovery Features' anchor='registrar-features'>
+    <p>An entity SHOULD provide one service discovery feature for each algorithm it supports. Ideally these features would be of the form "urn:iana:hash-function-text-names:foo" (where "foo" is the name of an algorithm registered with the IANA); however there is no urn:iana namespace at present. Until there is, we use features of the form "urn:xmpp:hash-function-text-names:foo" instead. Therefore the registry submission is as follows.</p>
+    <code caption='Registry Submission'><![CDATA[
+<var>
+  <name>urn:xmpp:hash-function-text-names:md5</name>
+  <desc>Support for the MD5 hashing algorithm</desc>
+  <doc>XEP-xxxx</doc>
+</var>
+<var>
+  <name>urn:xmpp:hash-function-text-names:sha-1</name>
+  <desc>Support for the SHA-1 hashing algorithm</desc>
+  <doc>XEP-xxxx</doc>
+</var>
+<var>
+  <name>urn:xmpp:hash-function-text-names:sha-224</name>
+  <desc>Support for the SHA-224 hashing algorithm</desc>
+  <doc>XEP-xxxx</doc>
+</var>
+<var>
+  <name>urn:xmpp:hash-function-text-names:sha-256</name>
+  <desc>Support for the SHA-256 hashing algorithm</desc>
+  <doc>XEP-xxxx</doc>
+</var>
+<var>
+  <name>urn:xmpp:hash-function-text-names:sha-384</name>
+  <desc>Support for the SHA-384 hashing algorithm</desc>
+  <doc>XEP-xxxx</doc>
+</var>
+<var>
+  <name>urn:xmpp:hash-function-text-names:sha-512</name>
+  <desc>Support for the SHA-512 hashing algorithm</desc>
+  <doc>XEP-xxxx</doc>
+</var>
+    ]]></code>
+  </section2>
 </section1>
 
+
 <section1 topic='Acknowledgements' anchor='ack'>
   <p>Thanks to Dave Cridland, Waqas Hussain, Glenn Maynard, and Remko Tronçon for their input.</p>
 </section1>