X-Git-Url: https://git.lizzy.rs/?a=blobdiff_plain;f=src%2Fscript%2Fcpp_api%2Fs_security.cpp;h=2afa3a191d1ce7b8b451c89cebba44570dc24caa;hb=5146086a64d5eeb480948d612a008a2ec81455d4;hp=876c7761a0c262a0d31bb257e8021d0cdaadf128;hpb=ecd20de64d273fefe9a2d65c3237b096fbfb036c;p=minetest.git

diff --git a/src/script/cpp_api/s_security.cpp b/src/script/cpp_api/s_security.cpp
index 876c7761a..2afa3a191 100644
--- a/src/script/cpp_api/s_security.cpp
+++ b/src/script/cpp_api/s_security.cpp
@@ -243,6 +243,7 @@ void ScriptApiSecurity::initializeSecurityClient()
 		"rawset",
 		"select",
 		"setfenv",
+		// getmetatable can be used to escape the sandbox
 		"setmetatable",
 		"tonumber",
 		"tostring",
@@ -264,6 +265,7 @@ void ScriptApiSecurity::initializeSecurityClient()
 	};
 	static const char *debug_whitelist[] = {
 		"getinfo",
+		"traceback"
 	};
 
 #if USE_LUAJIT
@@ -370,14 +372,16 @@ bool ScriptApiSecurity::isSecure(lua_State *L)
 	return secure;
 }
 
-
-#define CHECK_FILE_ERR(ret, fp) \
-	if (ret) { \
-		lua_pushfstring(L, "%s: %s", path, strerror(errno)); \
-		if (fp) std::fclose(fp); \
-		return false; \
+bool ScriptApiSecurity::safeLoadString(lua_State *L, const std::string &code, const char *chunk_name)
+{
+	if (code.size() > 0 && code[0] == LUA_SIGNATURE[0]) {
+		lua_pushliteral(L, "Bytecode prohibited when mod security is enabled.");
+		return false;
 	}
-
+	if (luaL_loadbuffer(L, code.data(), code.size(), chunk_name))
+		return false;
+	return true;
+}
 
 bool ScriptApiSecurity::safeLoadFile(lua_State *L, const char *path, const char *display_name)
 {
@@ -404,68 +408,49 @@ bool ScriptApiSecurity::safeLoadFile(lua_State *L, const char *path, const char
 	int c = std::getc(fp);
 	if (c == '#') {
 		// Skip the first line
-		while ((c = std::getc(fp)) != EOF && c != '\n');
-		if (c == '\n') c = std::getc(fp);
+		while ((c = std::getc(fp)) != EOF && c != '\n') {}
+		if (c == '\n')
+			std::getc(fp);
 		start = std::ftell(fp);
 	}
 
-	if (c == LUA_SIGNATURE[0]) {
-		lua_pushliteral(L, "Bytecode prohibited when mod security is enabled.");
-		std::fclose(fp);
-		if (path) {
-			delete [] chunk_name;
-		}
-		return false;
-	}
-
 	// Read the file
 	int ret = std::fseek(fp, 0, SEEK_END);
 	if (ret) {
 		lua_pushfstring(L, "%s: %s", path, strerror(errno));
-		std::fclose(fp);
 		if (path) {
+			std::fclose(fp);
 			delete [] chunk_name;
 		}
 		return false;
 	}
 
 	size_t size = std::ftell(fp) - start;
-	char *code = new char[size];
+	std::string code(size, '\0');
 	ret = std::fseek(fp, start, SEEK_SET);
 	if (ret) {
 		lua_pushfstring(L, "%s: %s", path, strerror(errno));
-		std::fclose(fp);
-		delete [] code;
 		if (path) {
+			std::fclose(fp);
 			delete [] chunk_name;
 		}
 		return false;
 	}
 
-	size_t num_read = std::fread(code, 1, size, fp);
-	if (path) {
+	size_t num_read = std::fread(&code[0], 1, size, fp);
+	if (path)
 		std::fclose(fp);
-	}
 	if (num_read != size) {
 		lua_pushliteral(L, "Error reading file to load.");
-		delete [] code;
-		if (path) {
+		if (path)
 			delete [] chunk_name;
-		}
 		return false;
 	}
 
-	if (luaL_loadbuffer(L, code, size, chunk_name)) {
-		delete [] code;
-		return false;
-	}
-
-	delete [] code;
-
-	if (path) {
+	bool result = safeLoadString(L, code, chunk_name);
+	if (path)
 		delete [] chunk_name;
-	}
-	return true;
+	return result;
 }
 
 
@@ -514,7 +499,12 @@ bool ScriptApiSecurity::checkPath(lua_State *L, const char *path,
 
 	// Get server from registry
 	lua_rawgeti(L, LUA_REGISTRYINDEX, CUSTOM_RIDX_SCRIPTAPI);
-	ScriptApiBase *script = (ScriptApiBase *) lua_touserdata(L, -1);
+	ScriptApiBase *script;
+#if INDIRECT_SCRIPTAPI_RIDX
+	script = (ScriptApiBase *) *(void**)(lua_touserdata(L, -1));
+#else
+	script = (ScriptApiBase *) lua_touserdata(L, -1);
+#endif
 	lua_pop(L, 1);
 	const IGameDef *gamedef = script->getGameDef();
 	if (!gamedef)
@@ -626,14 +616,9 @@ int ScriptApiSecurity::sl_g_load(lua_State *L)
 		code += std::string(buf, len);
 		lua_pop(L, 1); // Pop return value
 	}
-	if (code[0] == LUA_SIGNATURE[0]) {
-		lua_pushnil(L);
-		lua_pushliteral(L, "Bytecode prohibited when mod security is enabled.");
-		return 2;
-	}
-	if (luaL_loadbuffer(L, code.data(), code.size(), chunk_name)) {
+	if (!safeLoadString(L, code, chunk_name)) {
 		lua_pushnil(L);
-		lua_insert(L, lua_gettop(L) - 1);
+		lua_insert(L, -2);
 		return 2;
 	}
 	return 1;
@@ -647,16 +632,19 @@ int ScriptApiSecurity::sl_g_loadfile(lua_State *L)
 	ScriptApiBase *script = (ScriptApiBase *) lua_touserdata(L, -1);
 	lua_pop(L, 1);
 
+	// Client implementation
 	if (script->getType() == ScriptingType::Client) {
-		std::string display_path = readParam<std::string>(L, 1);
-		const std::string *path = script->getClient()->getModFile(display_path);
-		if (!path) {
-			std::string error_msg = "Coudln't find script called:" + display_path;
+		std::string path = readParam<std::string>(L, 1);
+		const std::string *contents = script->getClient()->getModFile(path);
+		if (!contents) {
+			std::string error_msg = "Coudln't find script called: " + path;
 			lua_pushnil(L);
 			lua_pushstring(L, error_msg.c_str());
 			return 2;
 		}
-		if (!safeLoadFile(L, path->c_str(), display_path.c_str())) {
+
+		std::string chunk_name = "@" + path;
+		if (!safeLoadString(L, *contents, chunk_name.c_str())) {
 			lua_pushnil(L);
 			lua_insert(L, -2);
 			return 2;
@@ -664,6 +652,8 @@ int ScriptApiSecurity::sl_g_loadfile(lua_State *L)
 		return 1;
 	}
 #endif
+
+	// Server implementation
 	const char *path = NULL;
 	if (lua_isstring(L, 1)) {
 		path = lua_tostring(L, 1);
@@ -692,15 +682,11 @@ int ScriptApiSecurity::sl_g_loadstring(lua_State *L)
 
 	size_t size;
 	const char *code = lua_tolstring(L, 1, &size);
+	std::string code_s(code, size);
 
-	if (size > 0 && code[0] == LUA_SIGNATURE[0]) {
+	if (!safeLoadString(L, code_s, chunk_name)) {
 		lua_pushnil(L);
-		lua_pushliteral(L, "Bytecode prohibited when mod security is enabled.");
-		return 2;
-	}
-	if (luaL_loadbuffer(L, code, size, chunk_name)) {
-		lua_pushnil(L);
-		lua_insert(L, lua_gettop(L) - 1);
+		lua_insert(L, -2);
 		return 2;
 	}
 	return 1;