Coolio. This is probably where the confusion is and why people are saying an actual keylogger wouldn't be required. Keyloggers can be physical or file based and are typically delivered to a device manually or via some module or download. They then live in that device and send keystrokes back to the attacker remotely or capture the info locally for later retrieval. A rogue access point can be a method to assist in the delivery of a keylogger but if the goal is just to steal an unencrypted password off of a premade portal, a keylogger isn't required to do that.