-- 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 configmanager = require "core.configmanager";

local log = require "util.logger".init("certmanager");

local ssl = ssl;

local ssl_newcontext = ssl and ssl.newcontext;

local tostring = tostring;

local pairs = pairs;

local type = type;

local io_open = io.open;

local t_concat = table.concat;

local t_insert = table.insert;

local prosody = prosody;

local config_path = prosody.paths.config;

local luasec_has_noticket, luasec_has_verifyext, luasec_has_no_compression;

if ssl then

	local luasec_major, luasec_minor = ssl._VERSION:match("^(%d+)%.(%d+)");

	luasec_has_noticket = tonumber(luasec_major)>0 or tonumber(luasec_minor)>=4;

	luasec_has_verifyext = tonumber(luasec_major)>0 or tonumber(luasec_minor)>=5;

	luasec_has_no_compression = tonumber(luasec_major)>0 or tonumber(luasec_minor)>=5;

end

module "certmanager"

-- Global SSL options if not overridden per-host

local global_ssl_config = configmanager.get("*", "ssl");

-- Built-in defaults

local core_defaults = {

	capath = "/etc/ssl/certs";

	protocol = "tlsv1+";

	verify = (ssl and ssl.x509 and { "peer", "client_once", }) or "none";

	options = {

		cipher_server_preference = true;

		no_ticket = luasec_has_noticket;

		no_compression = luasec_has_no_compression and configmanager.get("*", "ssl_compression") ~= true;

		-- Has no_compression? Then it has these too...

		single_dh_use = luasec_has_no_compression;

		single_ecdh_use = luasec_has_no_compression;

	};

	verifyext = { "lsec_continue", "lsec_ignore_purpose" };

	curve = "secp384r1";

	ciphers = "HIGH+kEDH:HIGH+kEECDH:HIGH:!PSK:!SRP:!3DES:!aNULL";

}

local path_options = { -- These we pass through resolve_path()

	key = true, certificate = true, cafile = true, capath = true, dhparam = true

}

local set_options = {

	options = true, verify = true, verifyext = true

}

if ssl and not luasec_has_verifyext and ssl.x509 then

	-- COMPAT mw/luasec-hg

	for i=1,#core_defaults.verifyext do -- Remove lsec_ prefix

		core_defaults.verify[#core_defaults.verify+1] = core_defaults.verifyext[i]:sub(6);

	end

end

local function merge_set(t, o)

	if type(t) ~= "table" then t = { t } end

	for k,v in pairs(t) do

		if v == true or v == false then

			o[k] = v;

		else

			o[v] = true;

		end

	end

	return o;

end

local protocols = { "sslv2", "sslv3", "tlsv1", "tlsv1_1", "tlsv1_2" };

for i = 1, #protocols do protocols[protocols[i] .. "+"] = i - 1; end

function create_context(host, mode, user_ssl_config)

	user_ssl_config = user_ssl_config or {}

	user_ssl_config.mode = mode;

	if not ssl then return nil, "LuaSec (required for encryption) was not found"; end

	if global_ssl_config then

		for option,default_value in pairs(global_ssl_config) do

			if user_ssl_config[option] == nil then

				user_ssl_config[option] = default_value;

			end

		end

	end

	for option,default_value in pairs(core_defaults) do

		if user_ssl_config[option] == nil then

			user_ssl_config[option] = default_value;

		end

	end

	for option in pairs(set_options) do

		local merged = {};

		merge_set(core_defaults[option], merged);

		if global_ssl_config then

			merge_set(global_ssl_config[option], merged);

		end

		merge_set(user_ssl_config[option], merged);

		local final_array = {};

		for opt, enable in pairs(merged) do

			if enable then

				final_array[#final_array+1] = opt;

			end

		end

		user_ssl_config[option] = final_array;

	end

	local min_protocol = protocols[user_ssl_config.protocol];

	if min_protocol then

		user_ssl_config.protocol = "sslv23";

		for i = 1, min_protocol do

			t_insert(user_ssl_config.options, "no_"..protocols[i]);

		end

	end

	-- We can't read the password interactively when daemonized

	user_ssl_config.password = user_ssl_config.password or

		function() log("error", "Encrypted certificate for %s requires 'ssl' 'password' to be set in config", host); end;

	for option in pairs(path_options) do

		if type(user_ssl_config[option]) == "string" then

			user_ssl_config[option] = resolve_path(config_path, user_ssl_config[option]);

		end

	end

	-- Allow the cipher list to be a table

	if type(user_ssl_config.ciphers) == "table" then

		user_ssl_config.ciphers = t_concat(user_ssl_config.ciphers, ":")

	end

	if mode == "server" then

		if not user_ssl_config.key then return nil, "No key present in SSL/TLS configuration for "..host; end

		if not user_ssl_config.certificate then return nil, "No certificate present in SSL/TLS configuration for "..host; end

	end

	-- LuaSec expects dhparam to be a callback that takes two arguments.

	-- We ignore those because it is mostly used for having a separate

	-- set of params for EXPORT ciphers, which we don't have by default.

	if type(user_ssl_config.dhparam) == "string" then

		local f, err = io_open(user_ssl_config.dhparam);

		if not f then return nil, "Could not open DH parameters: "..err end

		local dhparam = f:read("*a");

		f:close();

		user_ssl_config.dhparam = function() return dhparam; end

	end

	local ctx, err = ssl_newcontext(user_ssl_config);

	-- COMPAT Older LuaSec ignores the cipher list from the config, so we have to take care

	-- of it ourselves (W/A for #x)

	if ctx and user_ssl_config.ciphers then

		local success;

		success, err = ssl.context.setcipher(ctx, user_ssl_config.ciphers);

		if not success then ctx = nil; end

	end

	if not ctx then

		err = err or "invalid ssl config"

		local file = err:match("^error loading (.-) %(");

		if file then

			if file == "private key" then

				file = user_ssl_config.key or "your private key";

			elseif file == "certificate" then

				file = user_ssl_config.certificate or "your certificate file";

			end

			local reason = err:match("%((.+)%)$") or "some reason";

			if reason == "Permission denied" then

				reason = "Check that the permissions allow Prosody to read this file.";

			elseif reason == "No such file or directory" then

				reason = "Check that the path is correct, and the file exists.";

			elseif reason == "system lib" then

				reason = "Previous error (see logs), or other system error.";

			elseif reason == "(null)" or not reason then

				reason = "Check that the file exists and the permissions are correct";

			else

				reason = "Reason: "..tostring(reason):lower();

			end

			log("error", "SSL/TLS: Failed to load '%s': %s (for %s)", file, reason, host);

		else

			log("error", "SSL/TLS: Error initialising for %s: %s", host, err);

		end

	end

	return ctx, err;

end

function reload_ssl_config()

	global_ssl_config = configmanager.get("*", "ssl");

	if luasec_has_no_compression then

		core_defaults.options.no_compression = configmanager.get("*", "ssl_compression") ~= true;

	end

end

prosody.events.add_handler("config-reloaded", reload_ssl_config);

return _M;