# HG changeset patch
# User Matthew Wild <mwild1@gmail.com>
# Date 1631468996 -3600
# Node ID f95a1e197a07251e7308908a1cc5499cf189cb2d
# Parent  0bcbff950f1401b40be4279b89891e67d9eba5de
mod_auto_moved: New module implementing XEP-0283 r0.2.0

diff -r 0bcbff950f14 -r f95a1e197a07 mod_auto_moved/README.markdown
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mod_auto_moved/README.markdown	Sun Sep 12 18:49:56 2021 +0100
@@ -0,0 +1,31 @@
+---
+summary: XEP-0283: Moved
+labels:
+- 'Stage-Alpha'
+...
+
+Introduction
+============
+
+This module implements [XEP-0283: Moved](http://xmpp.org/extensions/xep-0283.html),
+a way for contacts to notify you that they have moved to a new address.
+
+This module is not necessary to generate such notifications - that can be done
+by clients, for example. What this module does is automatically verify such
+notifications and, if verification is successful, automatically update your
+roster (contact list).
+
+Configuration
+=============
+
+There is no configuration for this module, just add it to
+modules\_enabled as normal.
+
+Compatibility
+=============
+
+  ----- -------
+  0.11  Does not work
+  ----- -------
+  trunk Works
+  ----- -------
diff -r 0bcbff950f14 -r f95a1e197a07 mod_auto_moved/mod_auto_moved.lua
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mod_auto_moved/mod_auto_moved.lua	Sun Sep 12 18:49:56 2021 +0100
@@ -0,0 +1,90 @@
+local id = require "util.id";
+local jid = require "util.jid";
+local promise = require "util.promise";
+local rm = require "core.rostermanager";
+local st = require "util.stanza";
+
+local errors = require "util.error".init(module.name, {
+	["statement-not-found"] = { type = "cancel", condition = "item-not-found" };
+	["statement-mismatch"] = { type = "cancel", condition = "conlict" };
+});
+
+module:hook("presence/bare", function (event)
+	local origin, stanza = event.origin, event.stanza;
+	if stanza.attr.type ~= "subscribe" then
+		return; -- We're only interested in subscription requests
+	end
+	local moved = stanza:get_child("moved", "urn:xmpp:moved:1");
+	if not moved then
+		return; -- We're only interested in stanzas with a moved notification
+	end
+
+	local verification = stanza:get_child("moved-verification", "https://prosody.im/protocol/moved");
+	if verification then
+		return; -- We already attempted to verify this stanza
+	end
+
+	module:log("debug", "Received moved notification from %s", stanza.attr.from);
+
+	local old_jid = moved:get_child_text("old-jid");
+	if not old_jid then
+		return; -- Failed to read old JID
+	end
+
+	local to_user = jid.node(stanza.attr.to);
+	local new_jid_unverified = jid.bare(stanza.attr.from);
+
+	if not rm.is_contact_subscribed(to_user, module.host, old_jid) then
+		return; -- Old JID was not an existing contact, ignore
+	end
+
+	if rm.is_contact_pending_in(to_user, module.host, new_jid_unverified)
+	or rm.is_contact_subscribed(to_user, module.host, new_jid_unverified) then
+		return; -- New JID already subscribed or pending, ignore
+	end
+
+	local moved_statement_query = st.iq({ to = old_jid, type = "get", id = id.short() })
+		:tag("pubsub", { xmlns = "http://jabber.org/protocol/pubsub" })
+			:tag("items", { node = "urn:xmpp:moved:1" })
+				:tag("item", { id = "current" }):up()
+			:up()
+		:up();
+	-- TODO: Catch and handle <gone/> errors per note in XEP-0283.
+	module:send_iq(moved_statement_query):next(function (reply)
+		module:log("debug", "Statement reply: %s", reply.stanza);
+		local moved_statement = reply.stanza:find("{http://jabber.org/protocol/pubsub}pubsub/items/{http://jabber.org/protocol/pubsub}item/{urn:xmpp:moved:1}moved");
+		if not moved_statement then
+			return promise.reject(errors.new("statement-not-found")); -- No statement found
+		end
+
+		local new_jid = jid.prep(moved_statement:get_child_text("new-jid"));
+		if new_jid ~= new_jid_unverified then
+			return promise.reject(errors.new("statement-mismatch")); -- Verification failed; JIDs do not match
+		end
+
+		-- Verified!
+		module:log("info", "Verified moved notification <%s> -> <%s>", old_jid, new_jid);
+
+		-- Add incoming subscription and respond
+		rm.set_contact_pending_in(to_user, module.host, new_jid);
+		rm.subscribed(to_user, module.host, new_jid);
+		module:send(st.presence({ to = new_jid, from = to_user.."@"..module.host, type = "subscribed" }));
+		rm.roster_push(to_user, module.host, new_jid);
+
+		-- Request outgoing subscription if old JID had one
+		if rm.is_user_subscribed(to_user, module.host, old_jid) then
+			module:log("debug", "Requesting subscription to new JID");
+			rm.set_contact_pending_out(to_user, module.host, new_jid);
+			module:send(st.presence({ to = new_jid, from = to_user.."@"..module.host, type = "subscribe" }));
+		end
+	end):catch(function (err)
+		module:log("debug", "Failed to verify moved statement for <%s> -> <%s>: %s", old_jid, new_jid_unverified, require "util.serialization".serialize(err, "debug"));
+		stanza:reset()
+			:tag("moved-verification", { xmlns = "https://prosody.im/protocol/moved", status = "failed" })
+			:up();
+		module:send(stanza, origin);
+	end);
+
+	-- Halt processing of the stanza, for now
+	return true;
+end, 1);
diff -r 0bcbff950f14 -r f95a1e197a07 mod_auto_moved/tests/moved.scs
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mod_auto_moved/tests/moved.scs	Sun Sep 12 18:49:56 2021 +0100
@@ -0,0 +1,184 @@
+# XEP-0283: Moved
+
+[Client] Romeo
+	jid: romeo1@localhost
+	password: password
+
+[Client] RomeoNew
+	jid: romeo.new@localhost
+	password: password
+
+[Client] Juliet
+	jid: juliet.m@localhost
+	password: password
+
+-----
+
+# The parties connect
+Romeo connects
+
+Romeo sends:
+	<presence/>
+
+Romeo receives:
+	<presence from="${Romeo's full JID}"/>
+
+Juliet connects
+
+Juliet sends:
+	<presence/>
+
+Juliet receives:
+	<presence from="${Juliet's full JID}"/>
+
+RomeoNew connects
+
+RomeoNew sends:
+	<presence/>
+
+RomeoNew receives:
+	<presence from="${RomeoNew's full JID}"/>
+
+# They add each other
+Romeo sends:
+	<presence type="subscribe" to="${Juliet's JID}"/>
+
+Romeo receives:
+	<presence from="${Juliet's JID}" to="${Romeo's JID}" type="unavailable"/>
+
+Juliet receives:
+	<presence type="subscribe" to="${Juliet's JID}" from="${Romeo's JID}"/>
+
+Juliet sends:
+	<presence type="subscribed" to="${Romeo's JID}"/>
+
+Romeo receives:
+	<presence from="${Juliet's full JID}" to="${Romeo's JID}">
+	  <delay xmlns="urn:xmpp:delay" stamp="{scansion:any}" from="localhost"/>
+	</presence>
+
+Juliet sends:
+	<presence type="subscribe" to="${Romeo's JID}"/>
+
+Juliet receives:
+	<presence from="${Romeo's JID}" to="${Juliet's JID}" type="unavailable"/>
+
+Romeo receives:
+	<presence type="subscribe" to="${Romeo's JID}" from="${Juliet's JID}"/>
+
+Romeo sends:
+	<presence type="subscribed" to="${Juliet's JID}"/>
+
+Juliet receives:
+	<presence from="${Romeo's full JID}" to="${Juliet's JID}">
+	  <delay xmlns="urn:xmpp:delay" stamp="{scansion:any}" from="localhost"/>
+	</presence>
+
+Romeo receives:
+	<presence from="${Juliet's full JID}" to="${Romeo's JID}">
+	  <delay xmlns="urn:xmpp:delay" stamp="{scansion:any}" from="localhost"/>
+	</presence>
+
+# They request their rosters
+
+Juliet sends:
+	<iq type="get" id="roster1">
+		<query xmlns='jabber:iq:roster'/>
+	</iq>
+
+Juliet receives:
+	<iq type="result" id="roster1"/>
+
+RomeoNew sends:
+	<iq type="get" id="roster1">
+		<query xmlns='jabber:iq:roster'/>
+	</iq>
+
+RomeoNew receives:
+	<iq type="result" id="roster1"/>
+
+# They can now talk
+Juliet sends:
+	<message type="chat" to="${Romeo's JID}">
+	  <body>ohai</body>
+	</message>
+
+Romeo receives:
+	<message type="chat" to="${Romeo's JID}" from="${Juliet's full JID}">
+	  <body>ohai</body>
+	</message>
+
+# Romeo moves to a new account
+
+# Romeo publishes a moved statement
+
+Romeo sends:
+	<iq type='set' id='pub1'>
+		<pubsub xmlns='http://jabber.org/protocol/pubsub'>
+			<publish node='urn:xmpp:moved:1'>
+				<item id='current'>
+					<moved xmlns='urn:xmpp:moved:1'>
+						<new-jid>${RomeoNew's JID}</new-jid>
+					</moved>
+				</item>
+			</publish>
+			<publish-options>
+				<x xmlns='jabber:x:data' type='submit'>
+					<field var='FORM_TYPE' type='hidden'>
+						<value>http://jabber.org/protocol/pubsub#publish-options</value>
+					</field>
+					<field var='pubsub#access_model'>
+						<value>open</value>
+					</field>
+				</x>
+			</publish-options>
+		</pubsub>
+	</iq>
+
+Romeo receives:
+	<iq type="result" id="pub1">
+		<pubsub xmlns='http://jabber.org/protocol/pubsub'>
+			<publish node='urn:xmpp:moved:1'>
+				<item id='current'/>
+			</publish>
+		</pubsub>
+	</iq>
+
+
+
+# RomeoNew sends moved notification to Juliet
+RomeoNew sends:
+	<presence type="subscribe" to="${Juliet's JID}">
+		<moved xmlns="urn:xmpp:moved:1">
+			<old-jid>${Romeo's JID}</old-jid>
+		</moved>
+	</presence>
+
+RomeoNew receives:
+	<iq type='set' id="{scansion:any}">
+		<query ver="{scansion:any}" xmlns='jabber:iq:roster'>
+			<item jid="${Juliet's JID}" subscription='none' ask='subscribe'/>
+		</query>
+	</iq>
+
+# Juliet's server verifies and approves the subscription request
+
+RomeoNew receives:
+	<presence type="subscribed" from="${Juliet's JID}"/>
+
+RomeoNew receives:
+	<iq type='set' id="{scansion:any}">
+		<query ver="{scansion:any}" xmlns='jabber:iq:roster'>
+			<item jid="${Juliet's JID}" subscription='to' />
+		</query>
+	</iq>
+
+# Juliet's server notifies her via a roster push
+
+Juliet receives:
+	<iq type="set" id="{scansion:any}">
+		<query xmlns='jabber:iq:roster' ver='{scansion:any}'>
+			<item jid="${RomeoNew's JID}" subscription='from'/>
+		</query>
+	</iq>
+