plugins/adhoc/adhoc.lib.lua
author Jonas Schäfer <jonas@wielicki.name>
Mon, 10 Jan 2022 18:23:54 +0100
branch0.11
changeset 12185 783056b4e448
parent 8475 d88dc6827675
child 10569 421b2f8369fd
permissions -rw-r--r--
util.xml: Do not allow doctypes, comments or processing instructions Yes. This is as bad as it sounds. CVE pending. In Prosody itself, this only affects mod_websocket, which uses util.xml to parse the <open/> frame, thus allowing unauthenticated remote DoS using Billion Laughs. However, third-party modules using util.xml may also be affected by this. This commit installs handlers which disallow the use of doctype declarations and processing instructions without any escape hatch. It, by default, also introduces such a handler for comments, however, there is a way to enable comments nontheless. This is because util.xml is used to parse human-facing data, where comments are generally a desirable feature, and also because comments are generally harmless.

-- Copyright (C) 2009-2010 Florian Zeitz
--
-- This file is MIT/X11 licensed. Please see the
-- COPYING file in the source package for more information.
--

local st, uuid = require "util.stanza", require "util.uuid";

local xmlns_cmd = "http://jabber.org/protocol/commands";

local states = {}

local _M = {};

local function _cmdtag(desc, status, sessionid, action)
	local cmd = st.stanza("command", { xmlns = xmlns_cmd, node = desc.node, status = status });
	if sessionid then cmd.attr.sessionid = sessionid; end
	if action then cmd.attr.action = action; end

	return cmd;
end

function _M.new(name, node, handler, permission)
	return { name = name, node = node, handler = handler, cmdtag = _cmdtag, permission = (permission or "user") };
end

function _M.handle_cmd(command, origin, stanza)
	local cmdtag = stanza.tags[1]
	local sessionid = cmdtag.attr.sessionid or uuid.generate();
	local dataIn = {
		to = stanza.attr.to;
		from = stanza.attr.from;
		action = cmdtag.attr.action or "execute";
		form = cmdtag:get_child("x", "jabber:x:data");
	};

	local data, state = command:handler(dataIn, states[sessionid]);
	states[sessionid] = state;
	local cmdreply;
	if data.status == "completed" then
		states[sessionid] = nil;
		cmdreply = command:cmdtag("completed", sessionid);
	elseif data.status == "canceled" then
		states[sessionid] = nil;
		cmdreply = command:cmdtag("canceled", sessionid);
	elseif data.status == "error" then
		states[sessionid] = nil;
		local reply = st.error_reply(stanza, data.error.type, data.error.condition, data.error.message);
		origin.send(reply);
		return true;
	else
		cmdreply = command:cmdtag("executing", sessionid);
		data.actions = data.actions or { "complete" };
	end

	for name, content in pairs(data) do
		if name == "info" then
			cmdreply:tag("note", {type="info"}):text(content):up();
		elseif name == "warn" then
			cmdreply:tag("note", {type="warn"}):text(content):up();
		elseif name == "error" then
			cmdreply:tag("note", {type="error"}):text(content.message):up();
		elseif name == "actions" then
			local actions = st.stanza("actions", { execute = content.default });
			for _, action in ipairs(content) do
				if (action == "prev") or (action == "next") or (action == "complete") then
					actions:tag(action):up();
				else
					module:log("error", "Command %q at node %q provided an invalid action %q",
						command.name, command.node, action);
				end
			end
			cmdreply:add_child(actions);
		elseif name == "form" then
			cmdreply:add_child((content.layout or content):form(content.values));
		elseif name == "result" then
			cmdreply:add_child((content.layout or content):form(content.values, "result"));
		elseif name == "other" then
			cmdreply:add_child(content);
		end
	end
	local reply = st.reply(stanza);
	reply:add_child(cmdreply);
	origin.send(reply);

	return true;
end

return _M;