--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mod_invites_register/README.markdown	Fri Sep 11 16:30:51 2020 +0100
@@ -0,0 +1,63 @@
+---
+labels:
+- 'Stage-Beta'
+summary: 'Allow account registration using invite tokens'
+...
+
+Introduction
+============
+
+This module is part of the suite of modules that implement invite-based
+account registration for Prosody. The other modules are:
+
+- mod_invites
+- mod_invites_adhoc
+- mod_invites_page
+- mod_invites_register_web
+- mod_register_apps
+
+For details and a full overview, start with the mod_invites documentation.
+
+Details
+=======
+
+This module allows clients to register an account using an invite ('preauth')
+token generated by mod_invites. It implements the protocol described at
+[docs.modernxmpp.org/client/invites](https://docs.modernxmpp.org/client/invites)
+and [XEP-0401 version 0.3.0](https://xmpp.org/extensions/attic/xep-0401-0.3.0.html).
+
+**Note to developers:** the XEP-0401 protocol is expected to change in the future,
+though Prosody will attempt to maintain backwards compatibility with the 0.3.0 protocol
+for as long as necessary.
+
+This module is also responsible for implementing the optional server-side part
+of [XEP-0379: Pre-Authenticated Roster Subscriptions](https://xmpp.org/extensions/xep-0379.html).
+
+**Note to admins:** Loading this module will disable registration for users
+without an invite token by default. Control this behaviour 
+
+# Configuration
+
+| Name                     | Description                                              | Default |
+|--------------------------|----------------------------------------------------------|---------|
+| registration_invite_only | Require an invitation token for all account registration | `true`  |
+
+## Example: Invite-only registration
+
+This setup enables registration **only** for users that have a valid
+invite token.
+
+``` {.lua}
+allow_registration = true
+registration_invite_only = true
+```
+
+## Example: Open registration
+
+This setup allows completely **open registration**, even without
+an invite token.
+
+``` {.lua}
+allow_registration = true
+registration_invite_only = false
+```

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mod_invites_register/mod_invites_register.lua	Fri Sep 11 16:30:51 2020 +0100
@@ -0,0 +1,153 @@
+local st = require "util.stanza";
+local jid_split = require "util.jid".split;
+local jid_bare = require "util.jid".bare;
+local rostermanager = require "core.rostermanager";
+
+local require_encryption = module:get_option_boolean("c2s_require_encryption",
+	module:get_option_boolean("require_encryption", false));
+local invite_only = module:get_option_boolean("registration_invite_only", true);
+
+local invites;
+if prosody.shutdown then -- COMPAT hack to detect prosodyctl
+	invites = module:depends("invites");
+end
+
+local invite_stream_feature = st.stanza("register", { xmlns = "urn:xmpp:invite" }):up();
+module:hook("stream-features", function(event)
+	local session, features = event.origin, event.features;
+
+	-- Advertise to unauthorized clients only.
+	if session.type ~= "c2s_unauthed" or (require_encryption and not session.secure) then
+		return
+	end
+
+	features:add_child(invite_stream_feature);
+end);
+
+-- XEP-0379: Pre-Authenticated Roster Subscription
+module:hook("presence/bare", function (event)
+	local stanza = event.stanza;
+	if stanza.attr.type ~= "subscribe" then return end
+
+	local preauth = stanza:get_child("preauth", "urn:xmpp:pars:0");
+	if not preauth then return end
+	local token = preauth.attr.token;
+	if not token then return end
+
+	local username, host = jid_split(stanza.attr.to);
+
+	local invite, err = invites.get(token, username);
+
+	if not invite then
+		module:log("debug", "Got invalid token, error: %s", err);
+		return;
+	end
+
+	local contact = jid_bare(stanza.attr.from);
+
+	module:log("debug", "Approving inbound subscription to %s from %s", username, contact);
+	if rostermanager.set_contact_pending_in(username, host, contact, stanza) then
+		if rostermanager.subscribed(username, host, contact) then
+			invite:use();
+			rostermanager.roster_push(username, host, contact);
+
+			-- Send back a subscription request (goal is mutual subscription)
+			if not rostermanager.is_user_subscribed(username, host, contact)
+			and not rostermanager.is_contact_pending_out(username, host, contact) then
+				module:log("debug", "Sending automatic subscription request to %s from %s", contact, username);
+				if rostermanager.set_contact_pending_out(username, host, contact) then
+					rostermanager.roster_push(username, host, contact);
+					module:send(st.presence({type = "subscribe", to = contact }));
+				else
+					module:log("warn", "Failed to set contact pending out for %s", username);
+				end
+			end
+		end
+	end
+end, 1);
+
+-- Client is submitting a preauth token to allow registration
+module:hook("stanza/iq/urn:xmpp:pars:0:preauth", function(event)
+	local preauth = event.stanza.tags[1];
+	local token = preauth.attr.token;
+	local validated_invite = invites.get(token);
+	if not validated_invite then
+		local reply = st.error_reply(event.stanza, "cancel", "forbidden", "The invite token is invalid or expired");
+		event.origin.send(reply);
+		return true;
+	end
+	event.origin.validated_invite = validated_invite;
+	local reply = st.reply(event.stanza);
+	event.origin.send(reply);
+	return true;
+end);
+
+-- Registration attempt - ensure a valid preauth token has been supplied
+module:hook("user-registering", function (event)
+	local validated_invite = event.validated_invite or (event.session and event.session.validated_invite);
+	if invite_only and not validated_invite then
+		event.allowed = false;
+		event.reason = "Registration on this server is through invitation only";
+		return;
+	end
+	if validated_invite.additional_data and validated_invite.additional_data.allow_reset then
+		event.allow_reset = validated_invite.additional_data.allow_reset;
+	end
+end);
+
+-- Make a *one-way* subscription. User will see when contact is online,
+-- contact will not see when user is online.
+function subscribe(host, user_username, contact_username)
+	local user_jid = user_username.."@"..host;
+	local contact_jid = contact_username.."@"..host;
+	-- Update user's roster to say subscription request is pending...
+	rostermanager.set_contact_pending_out(user_username, host, contact_jid);
+	-- Update contact's roster to say subscription request is pending...
+	rostermanager.set_contact_pending_in(contact_username, host, user_jid);
+	-- Update contact's roster to say subscription request approved...
+	rostermanager.subscribed(contact_username, host, user_jid);
+	-- Update user's roster to say subscription request approved...
+	rostermanager.process_inbound_subscription_approval(user_username, host, contact_jid);
+end
+
+-- Make a mutual subscription between jid1 and jid2. Each JID will see
+-- when the other one is online.
+function subscribe_both(host, user1, user2)
+	subscribe(host, user1, user2);
+	subscribe(host, user2, user1);
+end
+
+-- Registration successful, if there was a preauth token, mark it as used
+module:hook("user-registered", function (event)
+	local validated_invite = event.validated_invite or (event.session and event.session.validated_invite);
+	if not validated_invite then
+		return;
+	end
+	local inviter_username = validated_invite.inviter;
+	local contact_username = event.username;
+	validated_invite:use();
+
+	if inviter_username then
+		module:log("debug", "Creating mutual subscription between %s and %s", inviter_username, contact_username);
+		subscribe_both(module.host, inviter_username, contact_username);
+	end
+
+	if validated_invite.additional_data then
+		module:log("debug", "Importing roles from invite");
+		local roles = validated_invite.additional_data.roles;
+		if roles then
+			module:open_store("roles"):set(contact_username, roles);
+		end
+	end
+end);
+
+-- Equivalent of user-registered but for when the account already existed
+-- (i.e. password reset)
+module:hook("user-password-reset", function (event)
+	local validated_invite = event.validated_invite or (event.session and event.session.validated_invite);
+	if not validated_invite then
+		return;
+	end
+	validated_invite:use();
+end);
+