Keyboard emulation (shell, QT, X)

Have anybody ideas about how to emulate keyboard events? For example, if I send login name and password to some tty I can't login. echo -en "mylogin\nmypassword" > /dev/tty1 (I whould like to login on tty1). Strings are printed correctly but not interpreted. Is it absolutely necessary to patch keyboard driver and recompile kernel to emulate keyboard? Is there any backdoors in Linux (such as virtual devices, shared memory, ioctls) that allow to emulate keyboard events? The same question is about keyboard emulation in QT (that works on FrameBuffer) an X. I assume that they are reading keyboard events from ttys where they were run, correct?