Re: lua sandbox environment

[Shmuel Zeigerman <shmuz@...>]

Abhinav Lele wrote:
> But I want selectively allow different libraries in the lua environment. 
> How can this be achieved ?

  lua_pushcfunction(L, luaopen_string);
  lua_call(L,0,0);

Do so for every library you want to load.

> Is the following approach okay :
> to remove library io
> executing the statement io=nil

Additionally, to prevent it from being require'd:
  package.loaded.io = nil

> Also I want strict control over what require keyword can load. So does 
> this imply, that I need to change lua code, and if so where ?

do
  local permitted = { lfs = true, lpeg = true, }
  local oldrequire = require
  require = function(libname)
    if not permitted[libname] then
      error("library `"..libname.."' not permitted")
    end
    return oldrequire(libname)
  end
end

--
Shmuel