libs/web/luasrc/sauth.lua

   1 --[[
   2
   3 Session authentication
   4 (c) 2008 Steven Barth <steven@midlink.org>
   5
   6 Licensed under the Apache License, Version 2.0 (the "License");
   7 you may not use this file except in compliance with the License.
   8 You may obtain a copy of the License at
   9
  10         http://www.apache.org/licenses/LICENSE-2.0
  11
  12 $Id$
  13
  14 ]]--
  15
  16 --- LuCI session library.
  17 module("luci.sauth", package.seeall)
  18 require("luci.fs")
  19 require("luci.util")
  20 require("luci.config")
  21
  22
  23 luci.config.sauth = luci.config.sauth or {}
  24 sessionpath = luci.config.sauth.sessionpath
  25 sessiontime = tonumber(luci.config.sauth.sessiontime)
  26
  27 --- Manually clean up expired sessions.
  28 function clean()
  29         local now   = os.time()
  30         local files = luci.fs.dir(sessionpath)
  31
  32         if not files then
  33                 return nil
  34         end
  35
  36         for i, file in pairs(files) do
  37                 local fname = sessionpath .. "/" .. file
  38                 local stat = luci.fs.stat(fname)
  39                 if stat and stat.type == "regular" and stat.atime + sessiontime < now then
  40                         luci.fs.unlink(fname)
  41                 end
  42         end
  43 end
  44
  45 --- Prepare session storage by creating the session directory.
  46 function prepare()
  47         luci.fs.mkdir(sessionpath)
  48         if not luci.fs.chmod(sessionpath, "a-rwx,u+rwx") then
  49                 error("Security Exception: Session path is not sane!")
  50         end
  51 end
  52
  53 --- Read a session and return its content.
  54 -- @param id    Session identifier
  55 -- @return              Session data
  56 function read(id)
  57         if not id or not sane() then
  58                 return
  59         end
  60         clean()
  61         return luci.fs.readfile(sessionpath .. "/" .. id)
  62 end
  63
  64
  65 --- Check whether Session environment is sane.
  66 -- @return Boolean status
  67 function sane()
  68         return luci.fs.stat(sessionpath, "mode") == "rwx------"
  69 end
  70
  71
  72 --- Write session data to a session file.
  73 -- @param id    Session identifier
  74 -- @param data  Session data
  75 function write(id, data)
  76         if not sane() then
  77                 prepare()
  78         end
  79         luci.fs.writefile(sessionpath .. "/" .. id, data)
  80         luci.fs.chmod(sessionpath .. "/" .. id, "a-rwx,u+rw")
  81 end