USB HID Keyboard emulator

Question

I want to make hardware keylogger from my Raspberry Pi model B. I think that I can connect keyboard to raspberry and connect raspberry to computer, but how I can emulate keyboard output?

I consider that here must be some low-level libraries for this purpose, but I can't find someone.

Thanks!

Answer 1

You need to implement HID device emulator on Pi in order to act like keyboard. But it seems impossible because Pi hasn't separate USB port.

No, on the Raspberry PI model B the USB hardware is actually connected to a built in Hub, this fixes the USB format as master, there is no way a model B can be a "slave device". Thats said, the SoC of the Raspberry PI is actually capable as being used for both a master and a slave USB device, so theoretically when using a model-A it could be possible to program it to behave as a slave device. Obviously its against the USB specification for a slave device to have a type-A connector, but with some soldering you could connect a type-B or even an USB-on-the-go connector.

source