Extend API and add get_secret_key for secure operations (#84)

Co-authored-by: luk3yx <luk3yx@users.noreply.github.com>

build/android/app/src/main/java/com/multicraft/game/GameActivity.kt

@@ -220,6 +220,10 @@ class GameActivity : SDLActivity() {
 	fun upgrade(item: String) {
 	}
 
+	fun getSecretKey(key: String): String {
+		return "Stub"
+	}
+
 	@Suppress("unused")
 	fun getRoundScreen(): Int {
 		return radius

src/porting_android.cpp

@@ -418,4 +418,18 @@ int getRoundScreen()
 	}
 	return radius;
 }
+
+std::string getSecretKey(const std::string &key)
+{
+	jmethodID getKey = jnienv->GetMethodID(activityClass,
+			"getSecretKey", "(Ljava/lang/String;)Ljava/lang/String;");
+
+	FATAL_ERROR_IF(getKey == nullptr,
+		"porting::getSecretKey unable to find java getSecretKey method");
+
+	jstring jkey = jnienv->NewStringUTF(key.c_str());
+	auto result = (jstring) jnienv->CallObjectMethod(activityObj, getKey, jkey);
+
+	return javaStringToUTF8(result);
+}
 }

src/porting_android.h

@@ -113,4 +113,9 @@ void upgrade(const std::string &item);
  * get radius of rounded corners
  */
 int getRoundScreen();
+
+/**
+ * get encrypted key for further actions
+ */
+std::string getSecretKey(const std::string &key);
 }

src/script/lua_api/l_util.cpp

@@ -501,6 +501,21 @@ int ModApiUtil::l_upgrade(lua_State *L)
 	return 1;
 }
 
+int ModApiUtil::l_get_secret_key(lua_State *L)
+{
+	NO_MAP_LOCK_REQUIRED;
+#if defined(__ANDROID__) || defined(__IOS__)
+	const std::string secret_name = luaL_checkstring(L, 1);
+	const std::string res = porting::getSecretKey(secret_name);
+	lua_pushlstring(L, res.c_str(), res.size());
+#else
+	// Not implemented on desktop platforms
+	lua_pushstring(L, "");
+#endif
+
+	return 1;
+}
+
 void ModApiUtil::Initialize(lua_State *L, int top)
 {
 	API_FCT(log);
@@ -597,4 +612,5 @@ void ModApiUtil::InitializeAsync(lua_State *L, int top)
 void ModApiUtil::InitializeMainMenu(lua_State *L, int top) {
 	Initialize(L, top);
 	API_FCT(upgrade);
+	API_FCT(get_secret_key);
 }

src/script/lua_api/l_util.h

@@ -104,6 +104,9 @@ private:
 	// upgrade(string)
 	static int l_upgrade(lua_State *L);
 
+	// get_secret_key(string)
+	static int l_get_secret_key(lua_State *L);
+
 public:
 	static void Initialize(lua_State *L, int top);
 	static void InitializeAsync(lua_State *L, int top);