-- 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 softreq = require"util.dependencies".softreq;

local ssl = softreq"ssl";

if not ssl then

	return {

		create_context = function ()

			return nil, "LuaSec (required for encryption) was not found";

		end;

		reload_ssl_config = function () end;

	}

end

local configmanager = require "core.configmanager";

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

local ssl_context = ssl.context or softreq"ssl.context";

local ssl_x509 = ssl.x509 or softreq"ssl.x509";

local ssl_newcontext = ssl.newcontext;

local new_config = require"util.sslconfig".new;

local tostring = tostring;

local pairs = pairs;

local type = type;

local io_open = io.open;

local select = select;

local prosody = prosody;

local resolve_path = require"util.paths".resolve_relative_path;

local config_path = prosody.paths.config;

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

local luasec_version = luasec_major * 100 + luasec_minor;

local luasec_has = {

	-- TODO If LuaSec ever starts exposing these things itself, use that instead

	cipher_server_preference = luasec_version >= 2;

	no_ticket = luasec_version >= 4;

	no_compression = luasec_version >= 5;

	single_dh_use = luasec_version >= 2;

	single_ecdh_use = luasec_version >= 2;

};

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";

	depth = 9;

	protocol = "tlsv1+";

	verify = (ssl_x509 and { "peer", "client_once", }) or "none";

	options = {

		cipher_server_preference = luasec_has.cipher_server_preference;

		no_ticket = luasec_has.no_ticket;

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

		single_dh_use = luasec_has.single_dh_use;

		single_ecdh_use = luasec_has.single_ecdh_use;

	};

	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

}

	-- 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

function create_context(host, mode, ...)

	local cfg = new_config();

	cfg:apply(core_defaults);

	cfg:apply(global_ssl_config);

	cfg:apply({

		mode = mode,

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

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

	});

	for i = select('#', ...), 1, -1 do

		cfg:apply(select(i, ...));

	end

	local user_ssl_config = cfg:final();

	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

	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

	-- 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, user_ssl_config;

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;