File

plugins/mod_flags.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 13583:e77ef9a4604f
line wrap: on
line source

local jid_node = require "prosody.util.jid".node;

local flags = module:open_store("account_flags", "keyval+");

-- API

function add_flag(username, flag, comment)
	local flag_data = {
		when = os.time();
		comment = comment;
	};

	local ok, err = flags:set_key(username, flag, flag_data);
	if not ok then
		return nil, err;
	end

	module:fire_event("user-flag-added/"..flag, {
		user = username;
		flag = flag;
		data = flag_data;
	});

	return true;
end

function remove_flag(username, flag)
	local ok, err = flags:set_key(username, flag, nil);
	if not ok then
		return nil, err;
	end

	module:fire_event("user-flag-removed/"..flag, {
		user = username;
		flag = flag;
	});

	return true;
end

function has_flag(username, flag) -- luacheck: ignore 131/has_flag
	local ok, err = flags:get_key(username, flag);
	if not ok and err then
		error("Failed to check flags for user: "..err);
	end
	return not not ok;
end

function get_flag_info(username, flag) -- luacheck: ignore 131/get_flag_info
	return flags:get_key(username, flag);
end

-- Shell commands

local function get_username(jid)
	return (assert(jid_node(jid), "please supply a valid user JID"));
end

module:add_item("shell-command", {
	section = "flags";
	section_desc = "View and manage flags on user accounts";
	name = "list";
	desc = "List flags for the given user account";
	args = {
		{ name = "jid", type = "string" };
	};
	host_selector = "jid";
	handler = function(self, jid) --luacheck: ignore 212/self
		local c = 0;

		local user_flags, err = flags:get(get_username(jid));

		if not user_flags and err then
			return false, "Unable to list flags: "..err;
		end

		if user_flags then
			local print = self.session.print;

			for flag_name, flag_data in pairs(user_flags) do
				print(flag_name, os.date("%Y-%m-%d %R", flag_data.when), flag_data.comment);
				c = c + 1;
			end
		end

		return true, ("%d flags listed"):format(c);
	end;
});

module:add_item("shell-command", {
	section = "flags";
	section_desc = "View and manage flags on user accounts";
	name = "add";
	desc = "Add a flag to the given user account, with optional comment";
	args = {
		{ name = "jid", type = "string" };
		{ name = "flag", type = "string" };
		{ name = "comment", type = "string" };
	};
	host_selector = "jid";
	handler = function(self, jid, flag, comment) --luacheck: ignore 212/self
		local username = get_username(jid);

		local ok, err = add_flag(username, flag, comment);
		if not ok then
			return false, "Failed to add flag: "..err;
		end

		return true, "Flag added";
	end;
});

module:add_item("shell-command", {
	section = "flags";
	section_desc = "View and manage flags on user accounts";
	name = "remove";
	desc = "Remove a flag from the given user account";
	args = {
		{ name = "jid", type = "string" };
		{ name = "flag", type = "string" };
	};
	host_selector = "jid";
	handler = function(self, jid, flag) --luacheck: ignore 212/self
		local username = get_username(jid);

		local ok, err = remove_flag(username, flag);
		if not ok then
			return false, "Failed to remove flag: "..err;
		end

		return true, "Flag removed";
	end;
});

module:add_item("shell-command", {
	section = "flags";
	section_desc = "View and manage flags on user accounts";
	name = "find";
	desc = "Find all user accounts with a given flag on the specified host";
	args = {
		{ name = "host", type = "string" };
		{ name = "flag", type = "string" };
	};
	host_selector = "host";
	handler = function(self, host, flag) --luacheck: ignore 212/self 212/host
		local users_with_flag = flags:get_key_from_all(flag);

		local print = self.session.print;
		local c = 0;
		for user, flag_data in pairs(users_with_flag) do
			print(user, os.date("%Y-%m-%d %R", flag_data.when), flag_data.comment);
			c = c + 1;
		end

		return true, ("%d accounts listed"):format(c);
	end;
});