Merge branch 'feature/xep-0373' into premerge

xep-0373.xml

@@ -18,7 +18,7 @@
   devices.</abstract>
   &LEGALNOTICE;
   <number>0373</number>
-  <status>Deferred</status>
+  <status>Experimental</status>
   <type>Standards Track</type>
   <sig>Standards</sig>
   <approver>Council</approver>
@@ -46,6 +46,18 @@
     <email>look@my.amazin.horse</email>
     <jid>valodim@stratum0.org</jid>
   </author>
+  <revision>
+    <version>0.5.0</version>
+    <date>2020-06-19</date>
+    <initials>fs</initials>
+    <remark>
+      <ul>
+        <li>Use RFC 4880 terminology: it is "primary key", not "master key".</li>
+        <li>Clarify encryption of secret key material.</li>
+        <li>Move the information from the 'date' attribute into the item ID.</li>
+      </ul>
+    </remark>
+  </revision>
   <revision>
     <version>0.4.0</version>
     <date>2018-07-30</date>
@@ -161,8 +173,9 @@
     <di><dt>Public-Key metadata node ("metadata node")</dt><dd>A PEP node containing metadata of the entity's public OpenPGP key.</dd></di>
     <di><dt>Public-Key data node ("data node")</dt><dd>A PEP node containing an entity's public OpenPGP key.</dd></di>
     <di><dt>Secret-Key node</dt><dd>A PEP node containing an entity's encrypted secret OpenPGP key.</dd></di>
-    <di><dt>OpenPGP v4 Fingerprint String</dt><dd>A String representing the OpenPGP v4 fingerprint of a key. If the key consists of a master key and subkeys, this is the fingerprint of the 
+    <di><dt>OpenPGP v4 Fingerprint String</dt><dd>A String representing the OpenPGP v4 fingerprint
-master key.</dd></di>
+    of a key. If the key consists of a primary key and subkeys, this is the fingerprint of the
+    primary key.</dd></di>
   </dl>
 
 </section1>
@@ -318,17 +331,19 @@ master key.</dd></di>
     encoded as a hexadecimal string using upper case characters<note>This matches the representation
     used by GnuPG minus the SPACE separation.</note>.</p>
 
+    <p> The publishing entity SHOULD set the PubSub item ID to the time the item is published encoded
+    as DateTime format specified in <cite>XEP-0082</cite>.</p>
+
     <p>The data node MUST contain an &lt;pubkey/&gt; element qualified by the 'urn:xmpp:openpgp:0'
-    namespace. An optional 'date' attribute holds the information about the last modification of the
+    namespace. The element MUST include a &lt;data/&gt; element which contains the data of the key
-    key as DateTime format of <cite>XEP-0082</cite>. The element MUST include a &lt;data/&gt;
+    Base64 encoded.</p>
-    element which contains the data of the key Base64 encoded.</p>
 
     <example caption='Saving the public key in the data node.'><![CDATA[
 <iq type='set' from='juliet@example.org/balcony' id='publish1'>
   <pubsub xmlns='http://jabber.org/protocol/pubsub'>
     <publish node='urn:xmpp:openpgp:0:public-keys:1357B01865B2503C18453D208CAC2A9678548E35'>
-      <item>
+      <item id='2020-01-21T10:46:21Z'>
-        <pubkey xmlns='urn:xmpp:openpgp:0' date='2018-01-21T10:46:21Z'>
+        <pubkey xmlns='urn:xmpp:openpgp:0'>
            <data>
              BASE64_OPENPGP_PUBLIC_KEY
            </data>
@@ -377,8 +392,9 @@ master key.</dd></di>
 
   <section2 topic='Discovering Public Keys of a User' anchor='discover-pubkey-list'>
 
-    <p>In order to discover the OpenPGP public keys, the interested entity first queries a remote
+    <p>In order to discover the OpenPGP public keys of a remote entity, the interested entity first
-    entities metadata note to learn about its currently annouced OpenPGP keys.</p>
+    queries the remote entity's metadata note to learn about the currently annouced OpenPGP
+    keys.</p>
 
     <example caption='Requesting the metadata node of a user.'><![CDATA[
 <iq from='romeo@example.org/orchard'
@@ -438,7 +454,7 @@ master key.</dd></di>
     id='getpub'>
   <pubsub xmlns='http://jabber.org/protocol/pubsub'>
     <items node='urn:xmpp:openpgp:0:public-keys:1357B01865B2503C18453D208CAC2A9678548E35'>
-      <item>
+      <item id='2020-01-21T10:46:21Z'>
         <pubkey xmlns='urn:xmpp:openpgp:0'>
           <data>
             BASE64_OPENPGP_PUBLIC_KEY
@@ -466,9 +482,14 @@ master key.</dd></di>
 
   <section2 topic='Receiving notifications about key changes' anchor='pubsub-notifications'>
 
+    <p>Entities creating PEP nodes defined herein SHOULD configure the nodes as notification-only
+    nodes by setting 'pubsub#deliver_payloads" configuration field to 'false'.</p>
+
     <p>Entities which are subscribed to the metadata node or advertise the
-    "urn:xmpp:openpgp:0:public-keys+notify" feature via &xep0115; (see <cite>XEP-0060 § 9.2</cite>)
+    "urn:xmpp:openpgp:0:public-keys+notify" feature via &xep0030; (see <cite>XEP-0060</cite> <link
-    receive a notification upon a node update.</p>
+    url='https://xmpp.org/extensions/xep-0060.html#filtered-notifications'>§ 9.2</link>) receive a
+    notification upon a node update. Entities subscribed to PEP nodes defined herein MUST be prepared
+    that PubSub notifications may be without the payload and only contain the published item's ID.</p>
 
   </section2>
 
@@ -659,7 +680,11 @@ master key.</dd></di>
         be concatenated in their transferable key format (<cite>RFC
         4880</cite> <link
         url='http://tools.ietf.org/html/rfc4880#section-11.2'>§
-        11.2</link>).
+        11.1</link>). The octet indicating string-to-key usage conventions
+        MUST be set to zero in the corresponding Secret-Key Packet(s)
+        (<cite>RFC 4880</cite> <link url='https://tools.ietf.org/html/rfc4880#section-5.5.3'>§ 5.5.3</link>).
+        The secret key material will be encrypted in step 4 using a
+        Symmetric-Key Encrypted Session Key Packet.
         </li>
         <li>A backup code is generated from secure random: The backup
         code consists of 24 upper case characters from the Latin
@@ -936,7 +961,8 @@ master key.</dd></di>
 <section1 topic='Acknowledgements' anchor='acknowledgements'>
 
   <p>Thanks to Emmanuel Gil Peyrot, Sergei Golovan, Marc Laporte, Georg
-  Lukas, Adithya Abraham Philip, Brian Cully, fiaxh and Paul Schaub for their feedback.</p>
+  Lukas, Adithya Abraham Philip, Brian Cully, fiaxh, Paul Schaub,
+  Philipp Hörist and Stefan Kropp for their feedback.</p>
 
   <p>The first draft of this specification was worked out and written
   on the wall of the 'Kymera' room in one of Google's buildings by the