File

plugins/mod_admin_telnet.lua @ 13801:a5d5fefb8b68 13.0

mod_tls: Enable Prosody's certificate checking for incoming s2s connections (fixes #1916) (thanks Damian, Zash) Various options in Prosody allow control over the behaviour of the certificate verification process For example, some deployments choose to allow falling back to traditional "dialback" authentication (XEP-0220), while others verify via DANE, hard-coded fingerprints, or other custom plugins. Implementing this flexibility requires us to override OpenSSL's default certificate verification, to allow Prosody to verify the certificate itself, apply custom policies and make decisions based on the outcome. To enable our custom logic, we have to suppress OpenSSL's default behaviour of aborting the connection with a TLS alert message. With LuaSec, this can be achieved by using the verifyext "lsec_continue" flag. We also need to use the lsec_ignore_purpose flag, because XMPP s2s uses server certificates as "client" certificates (for mutual TLS verification in outgoing s2s connections). Commit 99d2100d2918 moved these settings out of the defaults and into mod_s2s, because we only really need these changes for s2s, and they should be opt-in, rather than automatically applied to all TLS services we offer. That commit was incomplete, because it only added the flags for incoming direct TLS connections. StartTLS connections are handled by mod_tls, which was not applying the lsec_* flags. It previously worked because they were already in the defaults. This resulted in incoming s2s connections with "invalid" certificates being aborted early by OpenSSL, even if settings such as `s2s_secure_auth = false` or DANE were present in the config. Outgoing s2s connections inherit verify "none" from the defaults, which means OpenSSL will receive the cert but will not terminate the connection when it is deemed invalid. This means we don't need lsec_continue there, and we also don't need lsec_ignore_purpose (because the remote peer is a "server"). Wondering why we can't just use verify "none" for incoming s2s? It's because in that mode, OpenSSL won't request a certificate from the peer for incoming connections. Setting verify "peer" is how you ask OpenSSL to request a certificate from the client, but also what triggers its built-in verification.
author Matthew Wild <mwild1@gmail.com>
date Tue, 01 Apr 2025 17:26:56 +0100
parent 12977:74b9e05af71e
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-- 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.
--
-- luacheck: ignore 212/self

module:set_global();
module:depends("admin_shell");

local console_listener = { default_port = 5582; default_mode = "*a"; interface = "127.0.0.1" };

local async = require "prosody.util.async";
local st = require "prosody.util.stanza";

local def_env = module:shared("admin_shell/env");
local default_env_mt = { __index = def_env };

local function printbanner(session)
	local option = module:get_option_string("console_banner", "full");
	if option == "full" or option == "graphic" then
		session.print [[
                   ____                \   /     _
                    |  _ \ _ __ ___  ___  _-_   __| |_   _
                    | |_) | '__/ _ \/ __|/ _ \ / _` | | | |
                    |  __/| | | (_) \__ \ |_| | (_| | |_| |
                    |_|   |_|  \___/|___/\___/ \__,_|\__, |
                    A study in simplicity            |___/

]]
	end
	if option == "short" or option == "full" then
	session.print("Welcome to the Prosody administration console. For a list of commands, type: help");
	session.print("You may find more help on using this console in our online documentation at ");
	session.print("https://prosody.im/doc/console\n");
	end
	if option ~= "short" and option ~= "full" and option ~= "graphic" then
		session.print(option);
	end
end

console = {};

local runner_callbacks = {};

function runner_callbacks:ready()
	self.data.conn:resume();
end

function runner_callbacks:waiting()
	self.data.conn:pause();
end

function runner_callbacks:error(err)
	module:log("error", "Traceback[telnet]: %s", err);

	self.data.print("Fatal error while running command, it did not complete");
	self.data.print("Error: "..tostring(err));
end


function console:new_session(conn)
	local w = function(s) conn:write(s:gsub("\n", "\r\n")); end;
	local session = { conn = conn;
			send = function (t)
				if st.is_stanza(t) and (t.name == "repl-result" or t.name == "repl-output") then
					t = "| "..t:get_text().."\n";
				end
				w(tostring(t));
			end;
			print = function (...)
				local t = {};
				for i=1,select("#", ...) do
					t[i] = tostring(select(i, ...));
				end
				w("| "..table.concat(t, "\t").."\n");
			end;
			serialize = tostring;
			disconnect = function () conn:close(); end;
			};
	session.env = setmetatable({}, default_env_mt);

	session.thread = async.runner(function (line)
		console:process_line(session, line);
		session.send(string.char(0));
	end, runner_callbacks, session);

	-- Load up environment with helper objects
	for name, t in pairs(def_env) do
		if type(t) == "table" then
			session.env[name] = setmetatable({ session = session }, { __index = t });
		end
	end

	session.env.output:configure();

	return session;
end

function console:process_line(session, line)
	line = line:gsub("\r?\n$", "");
	if line == "bye" or line == "quit" or line == "exit" or line:byte() == 4 then
		session.print("See you!");
		session:disconnect();
		return;
	end
	return module:fire_event("admin/repl-input", { origin = session, stanza = st.stanza("repl-input"):text(line) });
end

local sessions = {};

function module.save()
	return { sessions = sessions }
end

function module.restore(data)
	if data.sessions then
		for conn in pairs(data.sessions) do
			conn:setlistener(console_listener);
			local session = console:new_session(conn);
			sessions[conn] = session;
		end
	end
end

function console_listener.onconnect(conn)
	-- Handle new connection
	local session = console:new_session(conn);
	sessions[conn] = session;
	printbanner(session);
	session.send(string.char(0));
end

function console_listener.onincoming(conn, data)
	local session = sessions[conn];

	local partial = session.partial_data;
	if partial then
		data = partial..data;
	end

	for line in data:gmatch("[^\n]*[\n\004]") do
		if session.closed then return end
		session.thread:run(line);
	end
	session.partial_data = data:match("[^\n]+$");
end

function console_listener.onreadtimeout(conn)
	local session = sessions[conn];
	if session then
		session.send("\0");
		return true;
	end
end

function console_listener.ondisconnect(conn, err) -- luacheck: ignore 212/err
	local session = sessions[conn];
	if session then
		session.disconnect();
		sessions[conn] = nil;
	end
end

function console_listener.ondetach(conn)
	sessions[conn] = nil;
end

module:provides("net", {
	name = "console";
	listener = console_listener;
	default_port = 5582;
	private = true;
});