"clock",
"date",
"difftime",
- "exit",
"getenv",
"setlocale",
"time",
lua_State *L = getStack();
- // Backup globals to the registry
- lua_getglobal(L, "_G");
- lua_rawseti(L, LUA_REGISTRYINDEX, CUSTOM_RIDX_GLOBALS_BACKUP);
- // Replace the global environment with an empty one
-#if LUA_VERSION_NUM <= 501
- int is_main = lua_pushthread(L); // Push the main thread
- FATAL_ERROR_IF(!is_main, "Security: ScriptApi's Lua state "
- "isn't the main Lua thread!");
-#endif
- lua_newtable(L); // Create new environment
- lua_pushvalue(L, -1);
- lua_setfield(L, -2, "_G"); // Set _G of new environment
-#if LUA_VERSION_NUM >= 502 // Lua >= 5.2
- // Set the global environment
- lua_rawseti(L, LUA_REGISTRYINDEX, LUA_RIDX_GLOBALS);
-#else // Lua <= 5.1
- // Set the environment of the main thread
- FATAL_ERROR_IF(!lua_setfenv(L, -2), "Security: Unable to set "
- "environment of the main Lua thread!");
- lua_pop(L, 1); // Pop thread
-#endif
-
- // Get old globals
- lua_rawgeti(L, LUA_REGISTRYINDEX, CUSTOM_RIDX_GLOBALS_BACKUP);
- int old_globals = lua_gettop(L);
+ int old_globals = backupGlobals(L);
// Copy safe base functions
lua_setglobal(L, "package");
lua_pop(L, 1); // Pop old package
+#if USE_LUAJIT
+ // Copy safe jit functions, if they exist
+ lua_getfield(L, -1, "jit");
+ if (!lua_isnil(L, -1)) {
+ lua_newtable(L);
+ copy_safe(L, jit_whitelist, sizeof(jit_whitelist));
+ lua_setglobal(L, "jit");
+ }
+ lua_pop(L, 1); // Pop old jit
+#endif
+ lua_pop(L, 1); // Pop globals_backup
+}
+
+void ScriptApiSecurity::initializeSecurityClient()
+{
+ static const char *whitelist[] = {
+ "assert",
+ "core",
+ "collectgarbage",
+ "DIR_DELIM",
+ "error",
+ "getfenv",
+ "ipairs",
+ "next",
+ "pairs",
+ "pcall",
+ "print",
+ "rawequal",
+ "rawget",
+ "rawset",
+ "select",
+ "setfenv",
+ "setmetatable",
+ "tonumber",
+ "tostring",
+ "type",
+ "unpack",
+ "_VERSION",
+ "xpcall",
+ // Completely safe libraries
+ "coroutine",
+ "string",
+ "table",
+ "math",
+ };
+ static const char *io_whitelist[] = {
+ "close",
+ "flush",
+ "read",
+ "type",
+ "write",
+ };
+ static const char *os_whitelist[] = {
+ "clock",
+ "date",
+ "difftime",
+ "time",
+ "setlocale",
+ };
+ static const char *debug_whitelist[] = {
+ "getinfo",
+ };
+
+ static const char *jit_whitelist[] = {
+ "arch",
+ "flush",
+ "off",
+ "on",
+ "opt",
+ "os",
+ "status",
+ "version",
+ "version_num",
+ };
+
+ m_secure = true;
+
+ lua_State *L = getStack();
+
+
+ int old_globals = backupGlobals(L);
+
+
+ // Copy safe base functions
+ lua_getglobal(L, "_G");
+ copy_safe(L, whitelist, sizeof(whitelist));
+
+ // And replace unsafe ones
+ SECURE_API(g, dofile);
+ SECURE_API(g, loadstring);
+ SECURE_API(g, require);
+ lua_pop(L, 1);
+
+
+ // Copy safe IO functions
+ lua_getfield(L, old_globals, "io");
+ lua_newtable(L);
+ copy_safe(L, io_whitelist, sizeof(io_whitelist));
+
+ // And replace unsafe ones
+ SECURE_API(io, open);
+ SECURE_API(io, input);
+ SECURE_API(io, output);
+ SECURE_API(io, lines);
+
+ lua_setglobal(L, "io");
+ lua_pop(L, 1); // Pop old IO
+
+
+ // Copy safe OS functions
+ lua_getfield(L, old_globals, "os");
+ lua_newtable(L);
+ copy_safe(L, os_whitelist, sizeof(os_whitelist));
+ lua_setglobal(L, "os");
+ lua_pop(L, 1); // Pop old OS
+
+
+ // Copy safe debug functions
+ lua_getfield(L, old_globals, "debug");
+ lua_newtable(L);
+ copy_safe(L, debug_whitelist, sizeof(debug_whitelist));
+ lua_setglobal(L, "debug");
+ lua_pop(L, 1); // Pop old debug
+
+ // Remove all of package
+ lua_newtable(L);
+ lua_setglobal(L, "package");
+
+#if USE_LUAJIT
// Copy safe jit functions, if they exist
lua_getfield(L, -1, "jit");
if (!lua_isnil(L, -1)) {
lua_setglobal(L, "jit");
}
lua_pop(L, 1); // Pop old jit
+#endif
lua_pop(L, 1); // Pop globals_backup
}
+int ScriptApiSecurity::backupGlobals(lua_State *L)
+{
+ // Backup globals to the registry
+ lua_getglobal(L, "_G");
+ lua_rawseti(L, LUA_REGISTRYINDEX, CUSTOM_RIDX_GLOBALS_BACKUP);
+
+ // Replace the global environment with an empty one
+#if LUA_VERSION_NUM <= 501
+ int is_main = lua_pushthread(L); // Push the main thread
+ FATAL_ERROR_IF(!is_main, "Security: ScriptApi's Lua state "
+ "isn't the main Lua thread!");
+#endif
+ lua_newtable(L); // Create new environment
+ lua_pushvalue(L, -1);
+ lua_setfield(L, -2, "_G"); // Set _G of new environment
+#if LUA_VERSION_NUM >= 502 // Lua >= 5.2
+ // Set the global environment
+ lua_rawseti(L, LUA_REGISTRYINDEX, LUA_RIDX_GLOBALS);
+#else // Lua <= 5.1
+ // Set the environment of the main thread
+ FATAL_ERROR_IF(!lua_setfenv(L, -2), "Security: Unable to set "
+ "environment of the main Lua thread!");
+ lua_pop(L, 1); // Pop thread
+#endif
+
+ // Get old globals
+ lua_rawgeti(L, LUA_REGISTRYINDEX, CUSTOM_RIDX_GLOBALS_BACKUP);
+ return lua_gettop(L);
+}
bool ScriptApiSecurity::isSecure(lua_State *L)
{
}
-bool ScriptApiSecurity::checkPath(lua_State *L, const char *path)
+bool ScriptApiSecurity::checkPath(lua_State *L, const char *path,
+ bool write_required, bool *write_allowed)
{
+ if (write_allowed)
+ *write_allowed = false;
+
std::string str; // Transient
- std::string norel_path = fs::RemoveRelativePathComponents(path);
- std::string abs_path = fs::AbsolutePath(norel_path);
+ std::string abs_path = fs::AbsolutePath(path);
if (!abs_path.empty()) {
// Don't allow accessing the settings file
// If we couldn't find the absolute path (path doesn't exist) then
// try removing the last components until it works (to allow
// non-existent files/folders for mkdir).
- std::string cur_path = norel_path;
+ std::string cur_path = path;
std::string removed;
while (abs_path.empty() && !cur_path.empty()) {
- std::string tmp_rmed;
- cur_path = fs::RemoveLastPathComponent(cur_path, &tmp_rmed);
- removed = tmp_rmed + (removed.empty() ? "" : DIR_DELIM + removed);
+ std::string component;
+ cur_path = fs::RemoveLastPathComponent(cur_path, &component);
+ if (component == "..") {
+ // Parent components can't be allowed or we could allow something like
+ // /home/user/minetest/worlds/foo/noexist/../../../../../../etc/passwd.
+ // If we have previous non-relative elements in the path we might be
+ // able to remove them so that things like worlds/foo/noexist/../auth.txt
+ // could be allowed, but those paths will be interpreted as nonexistent
+ // by the operating system anyways.
+ return false;
+ }
+ removed = component + (removed.empty() ? "" : DIR_DELIM + removed);
abs_path = fs::AbsolutePath(cur_path);
}
- if (abs_path.empty()) return false;
+ if (abs_path.empty())
+ return false;
// Add the removed parts back so that you can't, eg, create a
// directory in worldmods if worldmods doesn't exist.
- if (!removed.empty()) abs_path += DIR_DELIM + removed;
+ if (!removed.empty())
+ abs_path += DIR_DELIM + removed;
// Get server from registry
lua_rawgeti(L, LUA_REGISTRYINDEX, CUSTOM_RIDX_SCRIPTAPI);
ScriptApiBase *script = (ScriptApiBase *) lua_touserdata(L, -1);
lua_pop(L, 1);
- const Server *server = script->getServer();
-
- if (!server) return false;
+ const IGameDef *gamedef = script->getGameDef();
+ if (!gamedef)
+ return false;
// Get mod name
lua_rawgeti(L, LUA_REGISTRYINDEX, CUSTOM_RIDX_CURRENT_MOD_NAME);
// Builtin can access anything
if (mod_name == BUILTIN_MOD_NAME) {
+ if (write_allowed) *write_allowed = true;
return true;
}
// Allow paths in mod path
- const ModSpec *mod = server->getModSpec(mod_name);
- if (mod) {
- str = fs::AbsolutePath(mod->path);
- if (!str.empty() && fs::PathStartsWith(abs_path, str)) {
- return true;
+ // Don't bother if write access isn't important, since it will be handled later
+ if (write_required || write_allowed != NULL) {
+ const ModSpec *mod = gamedef->getModSpec(mod_name);
+ if (mod) {
+ str = fs::AbsolutePath(mod->path);
+ if (!str.empty() && fs::PathStartsWith(abs_path, str)) {
+ if (write_allowed) *write_allowed = true;
+ return true;
+ }
}
}
}
lua_pop(L, 1); // Pop mod name
- str = fs::AbsolutePath(server->getWorldPath());
- if (str.empty()) return false;
- // Don't allow access to world mods. We add to the absolute path
- // of the world instead of getting the absolute paths directly
- // because that won't work if they don't exist.
- if (fs::PathStartsWith(abs_path, str + DIR_DELIM + "worldmods") ||
- fs::PathStartsWith(abs_path, str + DIR_DELIM + "game")) {
- return false;
+ // Allow read-only access to all mod directories
+ if (!write_required) {
+ const std::vector<ModSpec> mods = gamedef->getMods();
+ for (size_t i = 0; i < mods.size(); ++i) {
+ str = fs::AbsolutePath(mods[i].path);
+ if (!str.empty() && fs::PathStartsWith(abs_path, str)) {
+ return true;
+ }
+ }
}
- // Allow all other paths in world path
- if (fs::PathStartsWith(abs_path, str)) {
- return true;
+
+ str = fs::AbsolutePath(gamedef->getWorldPath());
+ if (!str.empty()) {
+ // Don't allow access to other paths in the world mod/game path.
+ // These have to be blocked so you can't override a trusted mod
+ // by creating a mod with the same name in a world mod directory.
+ // We add to the absolute path of the world instead of getting
+ // the absolute paths directly because that won't work if they
+ // don't exist.
+ if (fs::PathStartsWith(abs_path, str + DIR_DELIM + "worldmods") ||
+ fs::PathStartsWith(abs_path, str + DIR_DELIM + "game")) {
+ return false;
+ }
+ // Allow all other paths in world path
+ if (fs::PathStartsWith(abs_path, str)) {
+ if (write_allowed) *write_allowed = true;
+ return true;
+ }
}
// Default to disallowing
if (lua_isstring(L, 1)) {
path = lua_tostring(L, 1);
- CHECK_SECURE_PATH(L, path);
+ CHECK_SECURE_PATH_INTERNAL(L, path, false, NULL);
}
if (!safeLoadFile(L, path)) {
luaL_checktype(L, 1, LUA_TSTRING);
const char *path = lua_tostring(L, 1);
- CHECK_SECURE_PATH(L, path);
+
+ bool write_requested = false;
+ if (with_mode) {
+ luaL_checktype(L, 2, LUA_TSTRING);
+ const char *mode = lua_tostring(L, 2);
+ write_requested = strchr(mode, 'w') != NULL ||
+ strchr(mode, '+') != NULL ||
+ strchr(mode, 'a') != NULL;
+ }
+ CHECK_SECURE_PATH_INTERNAL(L, path, write_requested, NULL);
push_original(L, "io", "open");
lua_pushvalue(L, 1);
{
if (lua_isstring(L, 1)) {
const char *path = lua_tostring(L, 1);
- CHECK_SECURE_PATH(L, path);
+ CHECK_SECURE_PATH_INTERNAL(L, path, false, NULL);
}
push_original(L, "io", "input");
{
if (lua_isstring(L, 1)) {
const char *path = lua_tostring(L, 1);
- CHECK_SECURE_PATH(L, path);
+ CHECK_SECURE_PATH_INTERNAL(L, path, true, NULL);
}
push_original(L, "io", "output");
{
if (lua_isstring(L, 1)) {
const char *path = lua_tostring(L, 1);
- CHECK_SECURE_PATH(L, path);
+ CHECK_SECURE_PATH_INTERNAL(L, path, false, NULL);
}
int top_precall = lua_gettop(L);
{
luaL_checktype(L, 1, LUA_TSTRING);
const char *path1 = lua_tostring(L, 1);
- CHECK_SECURE_PATH(L, path1);
+ CHECK_SECURE_PATH_INTERNAL(L, path1, true, NULL);
luaL_checktype(L, 2, LUA_TSTRING);
const char *path2 = lua_tostring(L, 2);
- CHECK_SECURE_PATH(L, path2);
+ CHECK_SECURE_PATH_INTERNAL(L, path2, true, NULL);
push_original(L, "os", "rename");
lua_pushvalue(L, 1);
{
luaL_checktype(L, 1, LUA_TSTRING);
const char *path = lua_tostring(L, 1);
- CHECK_SECURE_PATH(L, path);
+ CHECK_SECURE_PATH_INTERNAL(L, path, true, NULL);
push_original(L, "os", "remove");
lua_pushvalue(L, 1);
projects / dragonfireclient.git / blobdiff