File

mod_http_prebind/mod_http_prebind.lua @ 5401:c8d04ac200fc

mod_http_oauth2: Reject loopback URIs as client_uri This really should be a proper website with info, https://localhost is not good enough. Ideally we'd validate that it's got proper DNS and is actually reachable, but triggering HTTP or even DNS lookups seems like it would carry abuse potential that would best to avoid.
author Kim Alvefur <zash@zash.se>
date Tue, 02 May 2023 16:20:55 +0200
parent 4230:495a23d61418
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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;
	};
});