-- Prosody IM

-- Copyright (C) 2008-2010 Matthew Wild

-- Copyright (C) 2008-2010 Waqas Hussain

--

-- This project is MIT/X11 licensed. Please see the

-- COPYING file in the source package for more information.

--

local st = require "util.stanza";

local dataform_new = require "util.dataforms".new;

local usermanager_user_exists = require "core.usermanager".user_exists;

local usermanager_create_user = require "core.usermanager".create_user;

local usermanager_set_password = require "core.usermanager".set_password;

local usermanager_delete_user = require "core.usermanager".delete_user;

local nodeprep = require "util.encodings".stringprep.nodeprep;

local jid_bare = require "util.jid".bare;

local create_throttle = require "util.throttle".create;

local new_cache = require "util.cache".new;

local ip_util = require "util.ip";

local new_ip = ip_util.new_ip;

local match_ip = ip_util.match;

local parse_cidr = ip_util.parse_cidr;

local compat = module:get_option_boolean("registration_compat", true);

local allow_registration = module:get_option_boolean("allow_registration", false);

local additional_fields = module:get_option("additional_registration_fields", {});

local require_encryption = module:get_option("c2s_require_encryption") or module:get_option("require_encryption");

local account_details = module:open_store("account_details");

local field_map = {

	username = { name = "username", type = "text-single", label = "Username", required = true };

	password = { name = "password", type = "text-private", label = "Password", required = true };

	nick = { name = "nick", type = "text-single", label = "Nickname" };

	name = { name = "name", type = "text-single", label = "Full Name" };

	first = { name = "first", type = "text-single", label = "Given Name" };

	last = { name = "last", type = "text-single", label = "Family Name" };

	email = { name = "email", type = "text-single", label = "Email" };

	address = { name = "address", type = "text-single", label = "Street" };

	city = { name = "city", type = "text-single", label = "City" };

	state = { name = "state", type = "text-single", label = "State" };

	zip = { name = "zip", type = "text-single", label = "Postal code" };

	phone = { name = "phone", type = "text-single", label = "Telephone number" };

	url = { name = "url", type = "text-single", label = "Webpage" };

	date = { name = "date", type = "text-single", label = "Birth date" };

};

local title = module:get_option_string("registration_title",

	"Creating a new account");

local instructions = module:get_option_string("registration_instructions",

	"Choose a username and password for use with this service.");

local registration_form = dataform_new{

	title = title;

	instructions = instructions;

	field_map.username;

	field_map.password;

};

local registration_query = st.stanza("query", {xmlns = "jabber:iq:register"})

	:tag("instructions"):text(instructions):up()

	:tag("username"):up()

	:tag("password"):up();

for _, field in ipairs(additional_fields) do

	if type(field) == "table" then

		registration_form[#registration_form + 1] = field;

	elseif field_map[field] or field_map[field:sub(1, -2)] then

		if field:match("%+$") then

			field = field:sub(1, -2);

			field_map[field].required = true;

		end

		registration_form[#registration_form + 1] = field_map[field];

		registration_query:tag(field):up();

	else

		module:log("error", "Unknown field %q", field);

	end

end

registration_query:add_child(registration_form:form());

module:add_feature("jabber:iq:register");

local register_stream_feature = st.stanza("register", {xmlns="http://jabber.org/features/iq-register"}):up();

module:hook("stream-features", function(event)

	local session, features = event.origin, event.features;

	-- Advertise registration to unauthorized clients only.

	if not(allow_registration) or session.type ~= "c2s_unauthed" or (require_encryption and not session.secure) then

		return

	end

	features:add_child(register_stream_feature);

end);

-- Password change and account deletion handler

local function handle_registration_stanza(event)

	local session, stanza = event.origin, event.stanza;

	local log = session.log or module._log;

	local query = stanza.tags[1];

	if stanza.attr.type == "get" then

		local reply = st.reply(stanza);

		reply:tag("query", {xmlns = "jabber:iq:register"})

			:tag("registered"):up()

			:tag("username"):text(session.username):up()

			:tag("password"):up();

		session.send(reply);

	else -- stanza.attr.type == "set"

		if query.tags[1] and query.tags[1].name == "remove" then

			local username, host = session.username, session.host;

			-- This one weird trick sends a reply to this stanza before the user is deleted

			local old_session_close = session.close;

			session.close = function(self, ...)

				self.send(st.reply(stanza));

				return old_session_close(self, ...);

			end

			local ok, err = usermanager_delete_user(username, host);

			if not ok then

				log("debug", "Removing user account %s@%s failed: %s", username, host, err);

				session.close = old_session_close;

				session.send(st.error_reply(stanza, "cancel", "service-unavailable", err));

				return true;

			end

			log("info", "User removed their account: %s@%s", username, host);

			module:fire_event("user-deregistered", { username = username, host = host, source = "mod_register", session = session });

		else

			local username = nodeprep(query:get_child_text("username"));

			local password = query:get_child_text("password");

			if username and password then

				if username == session.username then

					if usermanager_set_password(username, password, session.host, session.resource) then

						session.send(st.reply(stanza));

					else

						-- TODO unable to write file, file may be locked, etc, what's the correct error?

						session.send(st.error_reply(stanza, "wait", "internal-server-error"));

					end

				else

					session.send(st.error_reply(stanza, "modify", "bad-request"));

				end

			else

				session.send(st.error_reply(stanza, "modify", "bad-request"));

			end

		end

	end

	return true;

end

module:hook("iq/self/jabber:iq:register:query", handle_registration_stanza);

if compat then

	module:hook("iq/host/jabber:iq:register:query", function (event)

		local session, stanza = event.origin, event.stanza;

		if session.type == "c2s" and jid_bare(stanza.attr.to) == session.host then

			return handle_registration_stanza(event);

		end

	end);

end

local function parse_response(query)

	local form = query:get_child("x", "jabber:x:data");

	if form then

		return registration_form:data(form);

	else

		local data = {};

		local errors = {};

		for _, field in ipairs(registration_form) do

			local name, required = field.name, field.required;

			if field_map[name] then

				data[name] = query:get_child_text(name);

				if (not data[name] or #data[name] == 0) and required then

					errors[name] = "Required value missing";

				end

			end

		end

		if next(errors) then

			return data, errors;

		end

		return data;

	end

end

local min_seconds_between_registrations = module:get_option_number("min_seconds_between_registrations");

local whitelist_only = module:get_option_boolean("whitelist_registration_only");

local whitelisted_ips = module:get_option_set("registration_whitelist", { "127.0.0.1", "::1" })._items;

local blacklisted_ips = module:get_option_set("registration_blacklist", {})._items;

local throttle_max = module:get_option_number("registration_throttle_max", min_seconds_between_registrations and 1);

local throttle_period = module:get_option_number("registration_throttle_period", min_seconds_between_registrations);

local throttle_cache_size = module:get_option_number("registration_throttle_cache_size", 100);

local blacklist_overflow = module:get_option_boolean("blacklist_on_registration_throttle_overload", false);

local throttle_cache = new_cache(throttle_cache_size, blacklist_overflow and function (ip, throttle)

	if not throttle:peek() then

		module:log("info", "Adding ip %s to registration blacklist", ip);

		blacklisted_ips[ip] = true;

	end

end or nil);

local function check_throttle(ip)

	if not throttle_max then return true end

	local throttle = throttle_cache:get(ip);

	if not throttle then

		throttle = create_throttle(throttle_max, throttle_period);

	end

	throttle_cache:set(ip, throttle);

	return throttle:poll(1);

end

local function ip_in_set(set, ip)

	if set[ip] then

		return true;

	end

	ip = new_ip(ip);

	for in_set in pairs(set) do

		if match_ip(ip, parse_cidr(in_set)) then

			return true;

		end

	end

	return false;

end

-- In-band registration

module:hook("stanza/iq/jabber:iq:register:query", function(event)

	local session, stanza = event.origin, event.stanza;

	local log = session.log or module._log;

	if not(allow_registration) or session.type ~= "c2s_unauthed" then

		log("debug", "Attempted registration when disabled or already authenticated");

		session.send(st.error_reply(stanza, "cancel", "service-unavailable"));

	elseif require_encryption and not session.secure then

		session.send(st.error_reply(stanza, "modify", "policy-violation", "Encryption is required"));

	else

		local query = stanza.tags[1];

		if stanza.attr.type == "get" then

			local reply = st.reply(stanza);

			reply:add_child(registration_query);

			session.send(reply);

		elseif stanza.attr.type == "set" then

			if query.tags[1] and query.tags[1].name == "remove" then

				session.send(st.error_reply(stanza, "auth", "registration-required"));

			else

				local data, errors = parse_response(query);

				if errors then

					log("debug", "Error parsing registration form:");

					for field, err in pairs(errors) do

						log("debug", "Field %q: %s", field, err);

					end

					session.send(st.error_reply(stanza, "modify", "not-acceptable"));

				else

					-- Check that the user is not blacklisted or registering too often

					if not session.ip then

						log("debug", "User's IP not known; can't apply blacklist/whitelist");

					elseif ip_in_set(blacklisted_ips, session.ip) or (whitelist_only and not ip_in_set(whitelisted_ips, session.ip)) then

						session.send(st.error_reply(stanza, "cancel", "not-acceptable", "You are not allowed to register an account."));

						return true;

					elseif throttle_max and not ip_in_set(whitelisted_ips, session.ip) then

						if not check_throttle(session.ip) then

							log("debug", "Registrations over limit for ip %s", session.ip or "?");

							session.send(st.error_reply(stanza, "wait", "not-acceptable"));

							return true;

						end

					end

					local username, password = nodeprep(data.username), data.password;

					data.username, data.password = nil, nil;

					local host = module.host;

					if not username or username == "" then

						log("debug", "The requested username is invalid.");

						session.send(st.error_reply(stanza, "modify", "not-acceptable", "The requested username is invalid."));

						return true;

					end

					module:fire_event("user-registering", user);

					if not user.allowed then

						log("debug", "Registration disallowed by module");

						session.send(st.error_reply(stanza, "modify", "not-acceptable", "The requested username is forbidden."));

					elseif usermanager_user_exists(username, host) then

						log("debug", "Attempt to register with existing username");

						session.send(st.error_reply(stanza, "cancel", "conflict", "The requested username already exists."));

					else

						-- TODO unable to write file, file may be locked, etc, what's the correct error?

						local error_reply = st.error_reply(stanza, "wait", "internal-server-error", "Failed to write data to disk.");

						if usermanager_create_user(username, password, host) then

							data.registered = os.time();

							if not account_details:set(username, data) then

								log("debug", "Could not store extra details");

								usermanager_delete_user(username, host);

								session.send(error_reply);

								return true;

							end

							session.send(st.reply(stanza)); -- user created!

							log("info", "User account created: %s@%s", username, host);

							module:fire_event("user-registered", {

								username = username, host = host, source = "mod_register",

								session = session });

						else

							log("debug", "Could not create user");

							session.send(error_reply);

						end

					end

				end

			end

		end

	end

	return true;

end);