-- mod_auth_ldap

local new_sasl = require "util.sasl".new;

local lualdap = require "lualdap";

local function ldap_filter_escape(s) return (s:gsub("[*()\\%z]", function(c) return ("\\%02x"):format(c:byte()) end)); end

-- Config options

local ldap_server = module:get_option_string("ldap_server", "localhost");

local ldap_rootdn = module:get_option_string("ldap_rootdn", "");

local ldap_password = module:get_option_string("ldap_password", "");

local ldap_tls = module:get_option_boolean("ldap_tls");

local ldap_scope = module:get_option_string("ldap_scope", "onelevel");

local ldap_filter = module:get_option_string("ldap_filter", "(uid=$user)"):gsub("%%s", "$user", 1);

local ldap_base = assert(module:get_option_string("ldap_base"), "ldap_base is a required option for ldap");

local host = ldap_filter_escape(module:get_option_string("realm", module.host));

-- Initiate connection

local ld = assert(lualdap.open_simple(ldap_server, ldap_rootdn, ldap_password, ldap_tls));

module.unload = function() ld:close(); end

local function get_user(username)

	module:log("debug", "get_user(%q)", username);

	for dn, attr in ld:search({

		base = ldap_base;

		scope = ldap_scope;

		sizelimit = 1;

		filter = ldap_filter:gsub("%$(%a+)", {

			user = ldap_filter_escape(username);

			host = host;

		});

	}) do return dn, attr; end

end

local provider = {};

function provider.create_user(username, password)

	return nil, "Account creation not available with LDAP.";

end

function provider.user_exists(username)

	return not not get_user(username);

end

function provider.set_password(username, password)

	local dn, attr = get_user(username);

	if not dn then return nil, attr end

	if attr.userPassword == password then return true end

	return ld:modify(dn, { '=', userPassword = password })();

end

if ldap_mode == "getpasswd" then

	function provider.get_password(username)

		local dn, attr = get_user(username);

		if dn and attr then

			return attr.userPassword;

		end

	end

	function provider.test_password(username, password)

		return provider.get_password(username) == password;

	end

	function provider.get_sasl_handler()

		return new_sasl(module.host, {

			plain = function(sasl, username)

				local password = provider.get_password(username);

				if not password then return "", nil; end

				return password, true;

			end

		});

	end

elseif ldap_mode == "bind" then

	local function test_password(userdn, password)

		return not not lualdap.open_simple(ldap_server, userdn, password, ldap_tls);

	end

	function provider.test_password(username, password)

		local dn = get_user(username);

		if not dn then return end

		return test_password(dn, password)

	end

	function provider.get_sasl_handler()

		return new_sasl(module.host, {

			plain_test = function(sasl, username, password)

				return provider.test_password(username, password), true;

			end

		});

	end

else

	module:log("error", "Unsupported ldap_mode %s", tostring(ldap_mode));

end

module:provides("auth", provider);