s_security.h

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// Luanti
// SPDX-License-Identifier: LGPL-2.1-or-later
// Copyright (C) 2013 celeron55, Perttu Ahola <celeron55@gmail.com>
 
#pragma once
 
#include "cpp_api/s_base.h"
 
 
#define CHECK_SECURE_PATH_INTERNAL(L, path, write_required, ptr) \
        if (!ScriptApiSecurity::checkPath(L, path, write_required, ptr)) { \
                throw LuaError(std::string("Mod security: Blocked attempted ") + \
                                (write_required ? "write to " : "read from ") + path); \
        }
#define CHECK_SECURE_PATH(L, path, write_required) \
        if (ScriptApiSecurity::isSecure(L)) { \
                CHECK_SECURE_PATH_INTERNAL(L, path, write_required, NULL); \
        }
#define CHECK_SECURE_PATH_POSSIBLE_WRITE(L, path, ptr) \
        if (ScriptApiSecurity::isSecure(L)) { \
                CHECK_SECURE_PATH_INTERNAL(L, path, false, ptr); \
        }
 
 
class ScriptApiSecurity : virtual public ScriptApiBase
{
public:
        // Sets up security on the ScriptApi's Lua state
        void initializeSecurity();
        void initializeSecurityClient();
        // Checks if the Lua state has been secured
        static bool isSecure(lua_State *L);
        // Loads a string as Lua code safely (doesn't allow bytecode).
        static bool safeLoadString(lua_State *L, const std::string &code, const char *chunk_name);
        // Loads a file as Lua code safely (doesn't allow bytecode).
        static bool safeLoadFile(lua_State *L, const char *path, const char *display_name = NULL);
        // Check if mod is whitelisted in the given setting
        // This additionally checks that the mod's main file scope is executing.
        static bool checkWhitelisted(lua_State *L, const std::string &setting);
        // Checks if mods are allowed to read (and optionally write) to the path
        static bool checkPath(lua_State *L, const char *path, bool write_required,
                        bool *write_allowed=NULL);
 
private:
        int getThread(lua_State *L);
        // sets the enviroment to the table thats on top of the stack
        void setLuaEnv(lua_State *L, int thread);
        // creates an empty Lua environment
        void createEmptyEnv(lua_State *L);
 
        // Syntax: "sl_" <Library name or 'g' (global)> '_' <Function name>
        // (sl stands for Secure Lua)
 
        static int sl_g_dofile(lua_State *L);
        static int sl_g_load(lua_State *L);
        static int sl_g_loadfile(lua_State *L);
        static int sl_g_loadstring(lua_State *L);
        static int sl_g_require(lua_State *L);
 
        static int sl_io_open(lua_State *L);
        static int sl_io_input(lua_State *L);
        static int sl_io_output(lua_State *L);
        static int sl_io_lines(lua_State *L);
 
        static int sl_os_rename(lua_State *L);
        static int sl_os_remove(lua_State *L);
        static int sl_os_setlocale(lua_State *L);
};