How to properly store and retrieve a token during authorization in an ios application?

Question

Objective-C

After authorization in the application, I receive a token in response, how to save it correctly and use it for further requests in the future? Here is the code:

- (IBAction)start:(id)sender{
    NSString *loging = loginf.text;
    NSString *passg = passwordf.text;
    NSString *getreq = @"url/log_in.php?login=";
    getreq = [getreq stringByAppendingString:loging];
    getreq = [getreq stringByAppendingString:@"&password="];
    getreq = [getreq stringByAppendingString:passg];
    
    
    // создаем запрос
    NSURLRequest *request = [NSURLRequest requestWithURL:[NSURL URLWithString:getreq]
                                             cachePolicy:NSURLRequestUseProtocolCachePolicy timeoutInterval:15.0];
    
    // создаём соединение и начинаем загрузку
    NSURLConnection *connection = [[NSURLConnection alloc] initWithRequest:request delegate:self];
    
    
    if (connection) {
        // соединение началось
        lableconnect.text = @"Connecting...";
        // создаем NSMutableData, чтобы сохранить полученные данные
        receivedData = [[NSMutableData data] retain];
    } else {
        // при попытке соединиться произошла ошибка
        lableconnect.text = @"Connection error!";
    }
    
    
}

- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response
{
    // получен ответ от сервера
    [receivedData setLength:0];
}

- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data
{
    // добавляем новые данные к receivedData
    [receivedData appendData:data];
}

- (void)connection:(NSURLConnection *)connection
  didFailWithError:(NSError *)error {
    // освобождаем соединение и полученные данные
    [connection release];
    [receivedData release];
    
    // выводим сообщение об ошибке
    NSString *errorString = [[NSString alloc] initWithFormat:@"Connection failed! Error - %@ %@ %@",
                             [error localizedDescription],
                             [error description],
                             [[error userInfo] objectForKey:NSURLErrorFailingURLStringErrorKey]];
    lableconnect.text = errorString;
    
    [errorString release];
}

- (void)connectionDidFinishLoading:(NSURLConnection *)connection {
 
    NSString *dataString = [[NSString alloc] initWithData:receivedData encoding:NSUTF8StringEncoding];
    
    lableconnect.text = dataString;
    
    if ([dataString  isEqual: @"{\"error\":[\"incorrect user\"]}"]) {
        lableconnect.text = @"Wrong login/pass";
    }
    
    [connection release];
    [receivedData release];
    [dataString release];
    
    
}

Answer 1

Store in some NSKeychain if you think more about security and NSUserDefaults if it doesn't matter. Use already asynchronous ways to work on http - AFNetworking or the option with blocks.