-- 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 type = type;

local io_open = io.open;

local prosody = prosody;

local resolve_path = configmanager.resolve_relative_path;

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

local default_capath = "/etc/ssl/certs";

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

local default_options = { "no_sslv2", "cipher_server_preference", luasec_has_noticket and "no_ticket" or nil };

local default_verifyext = { "lsec_continue", "lsec_ignore_purpose" };

if ssl and not luasec_has_verifyext and ssl.x509 then

	-- COMPAT mw/luasec-hg

	for i=1,#default_verifyext do -- Remove lsec_ prefix

		default_verify[#default_verify+1] = default_verifyext[i]:sub(6);

	end

end

if luasec_has_no_compression and configmanager.get("*", "ssl_compression") ~= true then

	default_options[#default_options+1] = "no_compression";

end

if luasec_has_no_compression then -- Has no_compression? Then it has these too...

	default_options[#default_options+1] = "single_dh_use";

	default_options[#default_options+1] = "single_ecdh_use";

end

function create_context(host, mode, user_ssl_config)

	user_ssl_config = user_ssl_config or default_ssl_config;

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

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

	local ssl_config = {

		mode = mode;

		protocol = user_ssl_config.protocol or "sslv23";

		key = resolve_path(config_path, user_ssl_config.key);

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

		certificate = resolve_path(config_path, user_ssl_config.certificate);

		capath = resolve_path(config_path, user_ssl_config.capath or default_capath);

		cafile = resolve_path(config_path, user_ssl_config.cafile);

		verify = user_ssl_config.verify or default_verify;

		verifyext = user_ssl_config.verifyext or default_verifyext;

		options = user_ssl_config.options or default_options;

		depth = user_ssl_config.depth;

		curve = user_ssl_config.curve or "secp384r1";

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

		dhparam = user_ssl_config.dhparam;

	};

	-- 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(ssl_config.dhparam) == "string" then

		local f, err = io_open(resolve_path(config_path, ssl_config.dhparam));

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

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

		f:close();

		ssl_config.dhparam = function() return dhparam; end

	end

	local ctx, err = ssl_newcontext(ssl_config);

	-- COMPAT: LuaSec 0.4.1 ignores the cipher list from the config, so we have to take

	-- care of it ourselves...

	if ctx and ssl_config.ciphers then

		local success;

		success, err = ssl.context.setcipher(ctx, 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 = ssl_config.key or "your private key";

			elseif file == "certificate" then

				file = 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()

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

end

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

return _M;