view mod_http_prebind/mod_http_prebind.lua @ 4651:8231774f5bfd

mod_cloud_notify_encrypted: Ensure body substring remains valid UTF-8 The `body:sub()` call risks splitting the string in the middle of a multi-byte UTF-8 sequence. This should have been caught by util.stanza validation, but that would have caused some havoc, at the very least causing the notification to not be sent. There have been no reports of this happening. Likely because this module isn't widely deployed among users with languages that use many longer UTF-8 sequences. The util.encodings.utf8.valid() function is O(n) where only the last sequence really needs to be checked, but it's in C and expected to be fast.
author Kim Alvefur <zash@zash.se>
date Sun, 22 Aug 2021 13:22:59 +0200
parents 495a23d61418
children
line wrap: on
line source

module:depends("http");

local http = require "net.http";
local format = require "util.format".format;
local json_encode = require "util.json".encode;
local promise = require "util.promise";
local xml = require "util.xml";
local t_insert = table.insert;

local function new_options(host)
	return {
		headers = {
			["Content-Type"] = "text/xml; charset=utf-8",
			["Host"] = host,
		},
		method = "POST",
	};
end

local function connect_to_bosh(url, hostname)
	local rid = math.random(100000, 100000000)
	local options = new_options(hostname);
	options.body = format([[<body content='text/xml; charset=utf-8'
	      hold='1'
	      rid='%d'
	      to='%s'
	      wait='60'
	      xml:lang='en'
	      xmpp:version='1.0'
	      xmlns='http://jabber.org/protocol/httpbind'
	      xmlns:xmpp='urn:xmpp:xbosh'/>]], rid, hostname);
	local rid = rid + 1;
	return promise.new(function (on_fulfilled, on_error)
		assert(http.request(url, options, function (body, code)
			if code ~= 200 then
				on_error("Failed to fetch, HTTP error code "..code);
				return;
			end
			local body = xml.parse(body);
			local sid = body.attr.sid;
			local mechanisms = {};
			for mechanism in body:get_child("features", "http://etherx.jabber.org/streams")
				:get_child("mechanisms", "urn:ietf:params:xml:ns:xmpp-sasl")
					:childtags("mechanism", "urn:ietf:params:xml:ns:xmpp-sasl") do
				mechanisms[mechanism:get_text()] = true;
			end
			on_fulfilled({ url = url, sid = sid, rid = rid, mechanisms = mechanisms });
		end));
	end);
end

local function authenticate(data)
	local options = new_options();
	options.body = format([[<body sid='%s'
	      rid='%d'
	      xmlns='http://jabber.org/protocol/httpbind'>
		<auth xmlns='urn:ietf:params:xml:ns:xmpp-sasl'
		      mechanism='ANONYMOUS'/>
	</body>]], data.sid, data.rid);
	data.rid = data.rid + 1;
	return promise.new(function (on_fulfilled, on_error)
		if data.mechanisms["ANONYMOUS"] == nil then
			on_error("No SASL ANONYMOUS mechanism supported on this host.");
			return;
		end
		assert(http.request(data.url, options, function (body, code)
			if code ~= 200 then
				on_error("Failed to fetch, HTTP error code "..code);
				return;
			end
			local body = xml.parse(body);
			local success = body:get_child("success", "urn:ietf:params:xml:ns:xmpp-sasl");
			if success then
				data.mechanisms = nil;
				on_fulfilled(data);
			else
				on_error("Authentication failed.");
			end
		end));
	end);
end;

local function restart_stream(data)
	local options = new_options();
	options.body = format([[
	<body sid='%s'
	      rid='%d'
	      xml:lang='en'
	      xmlns='http://jabber.org/protocol/httpbind'
	      xmlns:xmpp='urn:xmpp:xbosh'
	      xmpp:restart='true'/>]], data.sid, data.rid);
	data.rid = data.rid + 1;
	return promise.new(function (on_fulfilled, on_error)
		assert(http.request(data.url, options, function (body, code)
			if code ~= 200 then
				on_error("Failed to fetch, HTTP error code "..code);
				return;
			end
			local body = xml.parse(body);
			on_fulfilled(data);
		end));
	end);
end;

local function bind(data)
	local options = new_options();
	options.body = format([[
	<body sid='%s'
	      rid='%d'
	      xmlns='http://jabber.org/protocol/httpbind'>
		<iq xmlns='jabber:client'
		    type='set'>
			<bind xmlns='urn:ietf:params:xml:ns:xmpp-bind'/>
		</iq>
	</body>]], data.sid, data.rid);
	data.rid = data.rid + 1;
	return promise.new(function (on_fulfilled, on_error)
		assert(http.request(data.url, options, function (body, code)
			if code ~= 200 then
				on_error("Failed to fetch, HTTP error code "..code);
				return;
			end
			local body = xml.parse(body);
			local jid = body:get_child("iq", "jabber:client")
				:get_child("bind", "urn:ietf:params:xml:ns:xmpp-bind")
					:get_child_text("jid", "urn:ietf:params:xml:ns:xmpp-bind");
			on_fulfilled(json_encode({rid = data.rid, sid = data.sid, jid = jid}));
		end));
	end);
end;

module:provides("http", {
	route = {
		["GET"] = function (event)
			return connect_to_bosh("http://[::1]:5280/http-bind", module.host)
				:next(authenticate)
				:next(restart_stream)
				:next(bind);
		end;
	};
});