File

plugins/mod_mimicking.lua @ 13126:d043834f15d2

mod_http: Use RFC 7239 Forwarded header to find original client IP Prefer over X-Forwarded-* since it has an actual specification. Main practical difference is that Forwarded may carry more properties than only the IP address since it is a structured header. Since we parse it into an array, it is easier to do the logical thing and iterate backwards trough proxies until an untrusted one is encountered. Compare the handling of X-Forwarded-For. The 'secure' field now accounts for the full chain of proxies, which must be secure all the way to be considered secure.
author Kim Alvefur <zash@zash.se>
date Sat, 03 Jun 2023 17:10:04 +0200 (2023-06-03)
parent 12977:74b9e05af71e
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-- Prosody IM
-- Copyright (C) 2012 Florian Zeitz
-- Copyright (C) 2019 Kim Alvefur
--
-- This project is MIT/X11 licensed. Please see the
-- COPYING file in the source package for more information.
--

local encodings = require "prosody.util.encodings";
assert(encodings.confusable, "This module requires that Prosody be built with ICU");
local skeleton = encodings.confusable.skeleton;

local usage = require "prosody.util.prosodyctl".show_usage;
local usermanager = require "prosody.core.usermanager";
local storagemanager = require "prosody.core.storagemanager";

local skeletons
function module.load()
	if module.host ~= "*" then
		skeletons = module:open_store("skeletons");
	end
end

module:hook("user-registered", function(user)
	local skel = skeleton(user.username);
	local ok, err = skeletons:set(skel, { username = user.username });
	if not ok then
		module:log("error", "Unable to store mimicry data (%q => %q): %s", user.username, skel, err);
	end
end);

module:hook_global("user-deleted", function(user)
	if user.host ~= module.host then return end
	local skel = skeleton(user.username);
	local ok, err = skeletons:set(skel, nil);
	if not ok and err then
		module:log("error", "Unable to clear mimicry data (%q): %s", skel, err);
	end
end);

module:hook("user-registering", function(user)
	local existing, err = skeletons:get(skeleton(user.username));
	if existing then
		module:log("debug", "Attempt to register username '%s' which could be confused with '%s'", user.username, existing.username);
		user.allowed = false;
	elseif err then
		module:log("error", "Unable to check if new username '%s' can be confused with any existing user: %s", err);
	end
end);

function module.command(arg)
	if (arg[1] ~= "bootstrap" or not arg[2]) then
		usage("mod_mimicking bootstrap <host>", "Initialize username mimicry database");
		return;
	end

	local host = arg[2];

	local host_session = prosody.hosts[host];
	if not host_session then
		return "No such host";
	end

	storagemanager.initialize_host(host);
	usermanager.initialize_host(host);

	skeletons = storagemanager.open(host, "skeletons");

	local count = 0;
	for user in usermanager.users(host) do
		local skel = skeleton(user);
		local existing, err = skeletons:get(skel);
		if existing and existing.username ~= user then
			module:log("warn", "Existing usernames '%s' and '%s' are confusable", existing.username, user);
		elseif err then
			module:log("error", "Error checking for existing mimicry data (%q = %q): %s", user, skel, err);
		end
		local ok, err = skeletons:set(skel, { username = user });
		if ok then
			count = count + 1;
		elseif err then
			module:log("error", "Unable to store mimicry data (%q => %q): %s", user, skel, err);
		end
	end
	module:log("info", "%d usernames indexed", count);
end