spookeyboard.py

import grp
import os
import pwd
import sys
import termios
import time
import tty
import uinput

def drop_privileges(uid_name='nobody', gid_name='nogroup'):
    if os.getuid() != 0:
        return

    running_uid = pwd.getpwnam(uid_name).pw_uid
    running_gid = grp.getgrnam(gid_name).gr_gid

    os.setgroups([])
    os.setgid(running_gid)
    os.setuid(running_uid)
    os.umask(0o77)

# Key mapping and events
key_mapping = {
    'a': uinput.KEY_A,
    'b': uinput.KEY_B,
    'c': uinput.KEY_C,
    'd': uinput.KEY_D,
    'e': uinput.KEY_E,
    'f': uinput.KEY_F,
    'g': uinput.KEY_G,
    'h': uinput.KEY_H,
    'i': uinput.KEY_I,
    'j': uinput.KEY_J,
    'k': uinput.KEY_K,
    'l': uinput.KEY_L,
    'm': uinput.KEY_M,
    'n': uinput.KEY_N,
    'o': uinput.KEY_O,
    'p': uinput.KEY_P,
    'q': uinput.KEY_Q,
    'r': uinput.KEY_R,
    's': uinput.KEY_S,
    't': uinput.KEY_T,
    'u': uinput.KEY_U,
    'v': uinput.KEY_V,
    'w': uinput.KEY_W,
    'x': uinput.KEY_X,
    'y': uinput.KEY_Y,
    'z': uinput.KEY_Z,
    '\n': uinput.KEY_ENTER, # maybe this should be ctrl+j?
    '\r': uinput.KEY_ENTER,
    ' ': uinput.KEY_SPACE,
    '\x7f': uinput.KEY_BACKSPACE,
    '0': uinput.KEY_0,
    '1': uinput.KEY_1,
    '2': uinput.KEY_2,
    '3': uinput.KEY_3,
    '4': uinput.KEY_4,
    '5': uinput.KEY_5,
    '6': uinput.KEY_6,
    '7': uinput.KEY_7,
    '8': uinput.KEY_8,
    '9': uinput.KEY_9,
    '$': uinput.KEY_DOLLAR,
    ';': uinput.KEY_SEMICOLON,
    '.': uinput.KEY_DOT,
    '[': uinput.KEY_LEFTBRACE,
    ']': uinput.KEY_RIGHTBRACE,
    '(': uinput.KEY_KPLEFTPAREN,
    ')': uinput.KEY_KPRIGHTPAREN,
    '\t': uinput.KEY_TAB,
    '-': uinput.KEY_MINUS,
    '=': uinput.KEY_EQUAL,
    '\x1b': uinput.KEY_ESC,
    ',': uinput.KEY_COMMA,
    '`': uinput.KEY_GRAVE,
    '/': uinput.KEY_SLASH,
    '\\': uinput.KEY_BACKSLASH,
    '\'': uinput.KEY_APOSTROPHE,
    '\x1b[A': uinput.KEY_UP,
    '\x1b[B': uinput.KEY_DOWN,
    '\x1b[C': uinput.KEY_RIGHT,
    '\x1b[D': uinput.KEY_LEFT,
    'KEY_CAPSLOCK': uinput.KEY_CAPSLOCK,
    'KEY_LEFTALT': uinput.KEY_LEFTALT,
    'KEY_LEFTCTRL': uinput.KEY_LEFTCTRL,
    'KEY_LEFTSHIFT': uinput.KEY_LEFTSHIFT,
    # TODO: make this configurable
    '\x1b': uinput.KEY_CAPSLOCK,
}

def get_key():
    """Get a single key press, including full ANSI escape sequences."""
    fd = sys.stdin.fileno()
    old_settings = termios.tcgetattr(fd)
    try:
        tty.setraw(fd)
        ch = sys.stdin.read(1)
        if ch == '\x1b':
            # TODO: add timeout and break and send only '\x1b'. This is just regular escape.
            ch += sys.stdin.read(1)
            if ch[1] == '[':
                while True:
                    ch += sys.stdin.read(1)
                    if ch[-1] in 'ABCD~':
                        break
    finally:
        termios.tcsetattr(fd, termios.TCSADRAIN, old_settings)
    return ch

def remap(key, device):
    """Takes in an unknown event and tries to translate into known event and emit combo."""
    shiftmaps = {
        '!': '1',
        '@': '2',
        '#': '3',
        '$': '4',
        '%': '5',
        '^': '6',
        '&': '7',
        '*': '8',
        ',': '(',
        '.': ')',
        '{': '[',
        '}': ']',
        '_': '-',
        '<': ',',
        '>': '.',
        '?': '/',
        '|': '\\',
        '+': '=',
        '"': '\'',
        ':': ';',
        '~': '`',
    }

    ctrlmaps = {
        '\x01': 'a',
        '\x02': 'b',
        '\x03': 'c',
        '\x04': 'd',
        '\x05': 'e',
        '\x06': 'f',
        '\x07': 'g',
        '\x08': 'h',
        '\x09': 'i',
        '\x0A': 'j',
        '\x0B': 'k',
        '\x0C': 'l',
        '\x0D': 'm',
        '\x0E': 'n',
        '\x0F': 'o',
        '\x10': 'p',
        '\x11': 'q',
        '\x12': 'r',
        '\x13': 's',
        '\x14': 't',
        '\x15': 'u',
        '\x16': 'v',
        '\x17': 'w',
        '\x18': 'x',
        '\x19': 'y',
        '\x1A': 'z',
        '\x1B': '{',
        '\x1C': '|',
        '\x1D': '}',
        '\x1E': '~',
        '\x1F': 'DEL',
    }


    # special case...? ...or just me?
    if key == "\n":
        print(f"Sending key: CTRL + {repr('j')}, {repr(key_mapping['j'])}")
        device.emit_combo([key_mapping['KEY_LEFTCTRL'], key_mapping['j']])
    elif key in key_mapping:
        print(f"Sending key: {repr(key)}, {repr(key_mapping[key])}")
        device.emit_click(key_mapping[key])
    elif key.lower() in key_mapping:
        print(f"Sending key: SHIFT + {repr(key.lower())}, {repr(key_mapping[key.lower()])}")
        device.emit_combo([key_mapping['KEY_LEFTSHIFT'], key_mapping[key.lower()]])
    elif key in shiftmaps:
        print(f"Sending key: SHIFT + {repr(shiftmaps[key])}, {repr(shiftmaps[key])}")
        device.emit_combo([key_mapping['KEY_LEFTSHIFT'], key_mapping[shiftmaps[key]]])
    elif key in ctrlmaps:
        print(f"Sending key: CTRL + {repr(ctrlmaps[key])}, {repr(ctrlmaps[key])}")
        device.emit_combo([key_mapping['KEY_LEFTCTRL'], key_mapping[ctrlmaps[key]]])
    elif key.startswith("\x1b[1;"):
        # there are probably other event numbers, but I don't know them..
        # determine if shift, alt, shift+alt, or ctrl+alt event
        SHIFT     = "2"
        ALT       = "3"
        SHIFT_ALT = "4"
        CTRL_ALT  = "7"
        no_prefix = key.split("\x1b[1;", 1)[1]
        command, rest_of_string = no_prefix[0], no_prefix[1:]
        reconstituted = "\x1b[" + rest_of_string
        if command == SHIFT:
            print(f"Sending key: SHIFT + {repr(key_mapping[reconstituted])}, {repr(key_mapping[reconstituted])}")
            device.emit_combo([key_mapping['KEY_LEFTSHIFT'], key_mapping[reconstituted]])
        elif command == ALT:
            print(f"Sending key: ALT + {repr(key_mapping[reconstituted])}, {repr(key_mapping[reconstituted])}")
            device.emit_combo([key_mapping['KEY_LEFTALT'], key_mapping[reconstituted]])
        elif command == SHIFT_ALT:
            print(f"Sending key: SHIFT + ALT + {repr(key_mapping[reconstituted])}, {repr(key_mapping[reconstituted])}")
            device.emit_combo([key_mapping['KEY_LEFTSHIFT'], key_mapping['KEY_LEFTALT'], key_mapping[reconstituted]])
        elif command == CTRL_ALT:
            print(f"Sending key: CTRL + ALT + {repr(key_mapping[reconstituted])}, {repr(key_mapping[reconstituted])}")
            device.emit_combo([key_mapping['KEY_LEFTCTRL'], key_mapping['KEY_LEFTALT'], key_mapping[reconstituted]])
        else:
            print(f"TODO: {command}; {repr(rest_of_string)}")
    # TODO: this event should technically not be happening
    elif key == '\x1b\x1b':
        ## TODO: make this configurable
        print("Sending CAPS_LOCK")
        device.emit_click(key_mapping['KEY_CAPSLOCK'])
    # TODO: make recursive instead
    elif key.startswith('\x1b'):
        second_part = key.split("\x1b", 1)[1]
        if second_part in key_mapping:
            print(f"Sending key: ALT + {repr(second_part)}, {repr(key_mapping[second_part])}")
            device.emit_combo([key_mapping['KEY_LEFTALT'], key_mapping[second_part]])
        elif second_part.lower() in key_mapping:
            print(f"Sending key: SHIFT + ALT + {repr(second_part.lower())}, {repr(key_mapping[second_part.lower()])}")
            device.emit_combo([key_mapping['KEY_LEFTSHIFT'], key_mapping['KEY_LEFTALT'], key_mapping[second_part.lower()]])
        else:
            print(f"TODO: {repr(key)}")
    elif key == '\x00':
        print(f"Sending key: CTRL + SPACE, {repr(key_mapping[' '])}")
        device.emit_combo([key_mapping['KEY_LEFTCTRL'], key_mapping[' ']])
    else:
        print("WELP", repr(key))

def main():
    print("BEGIN")
    uinput_fd = uinput.fdopen()
    drop_privileges()
    print("DROPPED PRIVILEGES")


    with uinput.Device(key_mapping.values(), fd=uinput_fd) as device:
        time.sleep(1)  # Gives time for the device to fully register
        print("READY!")
        try:
            while True:
                key = get_key()
                # if key == '\x03':  # Ctrl+C
                #     break
                remap(key, device)
        except KeyboardInterrupt:
            print("Exiting...")

if __name__ == "__main__":
    main()