--[[ Session authentication (c) 2008 Steven Barth <steven@midlink.org> Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0 $Id$ ]]-- --- LuCI session library. module("luci.sauth", package.seeall) require("luci.util") require("luci.sys") require("luci.config") local nixio = require "nixio", require "nixio.util" local fs = require "nixio.fs" luci.config.sauth = luci.config.sauth or {} sessionpath = luci.config.sauth.sessionpath sessiontime = tonumber(luci.config.sauth.sessiontime) or 15 * 60 --- Prepare session storage by creating the session directory. function prepare() fs.mkdir(sessionpath, 700) if not sane() then error("Security Exception: Session path is not sane!") end end local function _read(id) local blob = fs.readfile(sessionpath .. "/" .. id) return blob end local function _write(id, data) local f = nixio.open(sessionpath .. "/" .. id, "w", 600) f:writeall(data) f:close() end local function _checkid(id) return not not (id and #id == 32 and id:match("^[a-fA-F0-9]+$")) end --- Write session data to a session file. -- @param id Session identifier -- @param data Session data table function write(id, data) if not sane() then prepare() end assert(_checkid(id), "Security Exception: Session ID is invalid!") assert(type(data) == "table", "Security Exception: Session data invalid!") data.atime = luci.sys.uptime() _write(id, luci.util.get_bytecode(data)) end --- Read a session and return its content. -- @param id Session identifier -- @return Session data table or nil if the given id is not found function read(id) if not id or #id == 0 then return nil end assert(_checkid(id), "Security Exception: Session ID is invalid!") if not sane(sessionpath .. "/" .. id) then return nil end local blob = _read(id) local func = loadstring(blob) setfenv(func, {}) local sess = func() assert(type(sess) == "table", "Session data invalid!") if sess.atime and sess.atime + sessiontime < luci.sys.uptime() then kill(id) return nil end -- refresh atime in session write(id, sess) return sess end --- Check whether Session environment is sane. -- @return Boolean status function sane(file) return luci.sys.process.info("uid") == fs.stat(file or sessionpath, "uid") and fs.stat(file or sessionpath, "modestr") == (file and "rw-------" or "rwx------") end --- Kills a session -- @param id Session identifier function kill(id) assert(_checkid(id), "Security Exception: Session ID is invalid!") fs.unlink(sessionpath .. "/" .. id) end --- Remove all expired session data files function reap() if sane() then local id for id in nixio.fs.dir(sessionpath) do if _checkid(id) then -- reading the session will kill it if it is expired read(id) end end end end