File

plugins/mod_groups.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.
--


local groups;
local members;

local datamanager = require "prosody.util.datamanager";
local jid_prep = require "prosody.util.jid".prep;

local module_host = module:get_host();

function inject_roster_contacts(event)
	local username, host= event.username, event.host;
	--module:log("debug", "Injecting group members to roster");
	local bare_jid = username.."@"..host;
	if not members[bare_jid] and not members[false] then return; end -- Not a member of any groups

	local roster = event.roster;
	local function import_jids_to_roster(group_name)
		for jid in pairs(groups[group_name]) do
			-- Add them to roster
			--module:log("debug", "processing jid %s in group %s", jid, group_name);
			if jid ~= bare_jid then
				if not roster[jid] then roster[jid] = {}; end
				roster[jid].subscription = "both";
				if groups[group_name][jid] then
					roster[jid].name = groups[group_name][jid];
				end
				if not roster[jid].groups then
					roster[jid].groups = { [group_name] = true };
				end
				roster[jid].groups[group_name] = true;
				roster[jid].persist = false;
			end
		end
	end

	-- Find groups this JID is a member of
	if members[bare_jid] then
		for _, group_name in ipairs(members[bare_jid]) do
			--module:log("debug", "Importing group %s", group_name);
			import_jids_to_roster(group_name);
		end
	end

	-- Import public groups
	if members[false] then
		for _, group_name in ipairs(members[false]) do
			--module:log("debug", "Importing group %s", group_name);
			import_jids_to_roster(group_name);
		end
	end

	if roster[false] then
		roster[false].version = true;
	end
end

function remove_virtual_contacts(username, host, datastore, data)
	if host == module_host and datastore == "roster" then
		local new_roster = {};
		for jid, contact in pairs(data) do
			if contact.persist ~= false then
				new_roster[jid] = contact;
			end
		end
		if new_roster[false] then
			new_roster[false].version = nil; -- Version is void
		end
		return username, host, datastore, new_roster;
	end

	return username, host, datastore, data;
end

function module.load()
	local groups_file = module:get_option_path("groups_file", nil, "config");
	if not groups_file then return; end

	module:hook("roster-load", inject_roster_contacts);
	datamanager.add_callback(remove_virtual_contacts);

	groups = { default = {} };
	members = { };
	local curr_group = "default";
	for line in io.lines(groups_file) do
		if line:match("^%s*%[.-%]%s*$") then
			curr_group = line:match("^%s*%[(.-)%]%s*$");
			if curr_group:match("^%+") then
				curr_group = curr_group:gsub("^%+", "");
				if not members[false] then
					members[false] = {};
				end
				members[false][#members[false]+1] = curr_group; -- Is a public group
			end
			module:log("debug", "New group: %s", curr_group);
			groups[curr_group] = groups[curr_group] or {};
		else
			-- Add JID
			local entryjid, name = line:match("([^=]*)=?(.*)");
			module:log("debug", "entryjid = '%s', name = '%s'", entryjid, name);
			local jid;
			jid = jid_prep(entryjid:match("%S+"));
			if jid then
				module:log("debug", "New member of %s: %s", curr_group, jid);
				groups[curr_group][jid] = name or false;
				members[jid] = members[jid] or {};
				members[jid][#members[jid]+1] = curr_group;
			elseif entryjid:match("%S") then
				module:log("warn", "Invalid JID: %q", entryjid);
			end
		end
	end
	module:log("info", "Groups loaded successfully");
end

function module.unload()
	datamanager.remove_callback(remove_virtual_contacts);
end

-- Public for other modules to access
function group_contains(group_name, jid)
	return groups[group_name][jid];
end