#!/usr/bin/python3

"""TorSwitch configures the onion router to redirect all internet traffic through SOCKS5 Tor proxy. This is version for SystemD.

Licensed under GNU GPLv3+ terms.
(c) 2023, xxx_stroboscope_420_xxx
"""

import sys
import os
import getopt
import requests
import subprocess
import time
import random
import signal
from stem import Signal
from stem.control import Controller
from packaging import version



VERSION   = "1.2"

IP_API    = "https://api.ipify.org/?format=json"
TOR_CHECK = "https://check.torproject.org"
UA        = "Mozilla/5.0 (Windows NT 10.0; rv:102.0) Gecko/20100101 Firefox/102.0"

class font:
	# Colors of foreground
	RED       = "\033[31m"
	LIGHTRED  = "\033[91m"
	YELLOW    = "\033[93m"
	GREEN     = "\033[92m"
	BLUE      = "\033[34m"
	LIGHTBLUE = "\033[94m"
	GRAY      = "\033[90m"
	WHITE     = "\033[97m"
	# Colors of background
	BG_RED    = "\033[41m"
	BG_BLUE   = "\033[104m"
	# Special
	CRIT      = BG_RED + WHITE # Critical error
	ERR       = RED            # Just error
	WARN      = YELLOW         # Warning
	TIME      = GRAY           # Timestamp
	EXEC      = LIGHTBLUE      # Executed command
	# Not colors
	BOLD      = "\033[1m"
	ENDC      = "\033[0m"

LOGO = f"""{font.RED + font.BOLD}

  _____
 |_   _|__  _ __
   | |/ _ \| '__|
   | | (_) | |
   |_|\___/|_| SWITCH v{VERSION}


{font.ENDC}"""
USAGE = f"""
{font.BOLD}Usage:{font.ENDC}
-s, --start
	Setup Tor as system-wide proxy
-r, --switch
	Request new Tor exit node
-x, --stop
	Shut down onion router and restore system defaults
-i, --info
	Show information about current connection
-h, --help
	Show this text and exit
"""

TOR_TRANS_PORT   = 9040
TOR_SOCKS_PORT   = 9050
TOR_CONTROL_PORT = 9051
TOR_DNS_PORT     = 9053
TOR_HTTP_PORT    = 9080
NON_TOR_RNG      = "192.168.1.0/24 192.168.0.0/24"

FileConfigTorrcTorswitcher = "/etc/tor/torswitcherrc"
FileConfigResolv           = "/etc/resolv.conf"
FileLogTorswitcher         = "./torswitcher.log"
FileLogTor                 = "/var/log/tor/notices.log"
DirTorData                 = "/var/lib/tor"

StringConfigTorrcTorSwitcher = f"""
SOCKSPort {TOR_SOCKS_PORT}
HTTPTunnelPort {TOR_HTTP_PORT}
Log notice file {FileLogTor}
DataDirectory {DirTorData}
VirtualAddrNetwork 10.0.0.0/10
AutomapHostsOnResolve 1
TransPort {TOR_TRANS_PORT}
DNSPort {TOR_DNS_PORT}
ControlPort {TOR_CONTROL_PORT}
RunAsDaemon 1
"""
StringConfigResolv = "nameserver 127.0.0.1"

LogToFile = False



# Remove any colors from text
def strip_colors(text):
	return text.replace(font.RED,"").replace(font.LIGHTRED,"").replace(font.YELLOW,"").replace(font.GREEN,"").replace(font.BLUE,"")\
			.replace(font.LIGHTBLUE,"").replace(font.GRAY,"").replace(font.WHITE,"").replace(font.BG_RED,"").replace(font.CRIT,"")\
			.replace(font.ERR,"").replace(font.WARN,"").replace(font.TIME,"").replace(font.EXEC,"").replace(font.BOLD,"").replace(font.ENDC,"")\
			.replace(font.BG_BLUE,"")

# Print log line
def log(text, endt="\n"):
	global LogToFile
	global FileLogTorswitcher
	now = time.strftime("%H:%M:%S", time.localtime())
	print(f"{font.TIME}[{now}]{font.ENDC} {text}", end=endt)
	if LogToFile:
		try:
			with open(FileLogTorswitcher, "at") as fd:
				fd.write(f"[{now}] {strip_colors(text)}{endt}")
		except Exception as exc:
			print(f"{font.ERR}Error: can not write log line to file '{FileLogTorswitcher}'{font.ENDC}")

# Print log line w/o time stamp
def logapp(text, endt="\n"):
	global LogToFile
	global FileLogTorswitcher
	print(f"{text}", end=endt)
	if LogToFile:
		try:
			with open(FileLogTorswitcher, "at") as fd:
				fd.write(f"{strip_colors(text)}{endt}")
		except Exception as exc:
			print(f"{font.ERR}Error: can not write log line to file '{FileLogTorswitcher}'{font.ENDC}")

# Handler for interrupt signal
def sigint_handler(signum, frame):
	log(f"{font.WARN}User interrupt ! shutting down{font.ENDC}")
	stop_tor_proxy()

# Execute command with printing it at terminal
def execute(cmd):
	log(f"{font.EXEC}Executing '{cmd}'...{font.ENDC}")
	os.system(cmd)

# Get current public IP
def ip():
	retries = 20
	while retries:
		retries -= 1
		try:
			jsonRes = requests.get(IP_API,headers={"User-Agent":UA}).json()
			return jsonRes["ip"]
		except:
			log(f"{font.ERR}Error: cant fetch IP{font.ENDC}")
			continue
	return "cant fetch ip address"

# Check if we connected via Tor network
def check_tor():
	retries = 20
	while retries:
		retries -= 1
		try:
			resp = requests.get(TOR_CHECK)
			if resp.status_code != 200:
				log(f"{font.ERR}Error: cant access check.torproject.org{font.ENDC}")
				continue
			if "Congratulations. This browser is configured to use Tor." in resp.text:
				return True
			else:
				return False
		except:
			log(f"{font.ERR}Error: something went wrong while trying to access check.torproject.org{font.ENDC}")
			continue
	log(f"{font.ERR}Error: retries limit exceeded{font.ENDC}")
	return False

# Check if we running as root
def check_root():
	if os.geteuid() != 0:
		log(f"{font.CRIT}CRITICAL: you must be root, say the magic word 'sudo'. Aborting...{font.ENDC}")
		sys.exit(1)

# Check if file contains supplied string
def file_contains(path, text):
	try:
		with open(path, "rt") as fd:
			buff = fd.read()
		return (text in buff)
	except Exception as exc:
		log(f"{font.WARN}Warning: error occured while trying to read file '{path}': {exc}{font.ENDC}")
		return False

# Print logo
def logo():
	print(LOGO) # TODO: make this look better

# Print usage text
def usage():
	logo()
	print(USAGE)
	sys.exit(0)

def setup_tor_proxy():
	log(f"{font.GREEN}Trying to setup onion router as system-wide proxy{font.ENDC}")
	check_root()
	if os.path.exists(FileConfigTorrcTorswitcher) and file_contains(FileConfigTorrcTorswitcher, StringConfigTorrcTorSwitcher):
		log(f"Torrc file ('{FileConfigTorrcTorswitcher}') already configured")
	else:
		log("Writing torcc file... ", "")
		with open(FileConfigTorrcTorswitcher, "wt") as fd:
			fd.write(StringConfigTorrcTorSwitcher)
		logapp(f"{font.GREEN}[done]{font.ENDC}")
	if file_contains(FileConfigResolv, StringConfigResolv):
		log(f"DNS '{FileConfigResolv}' file already configured")
	else:
		log(f"Saving original DNS '{FileConfigResolv}' file")
		execute(f"sudo cp '{FileConfigResolv}' '{FileConfigResolv}.bak'")
		log("Now creating our new... ", "")
		with open(FileConfigResolv, "wt") as fd:
			fd.write(StringConfigResolv)
		logapp(f"{font.GREEN}[done]{font.ENDC}")

	log("Stopping tor service")
	execute("sudo systemctl stop tor")
	log("Freeing tor control port")
	execute(f"sudo fuser -k {TOR_CONTROL_PORT}/tcp > /dev/null 2>&1")
	log("Starting new tor daemon")
	execute(f"sudo -u debian-tor tor -f {FileConfigTorrcTorswitcher} > /dev/null")
	log("Setting up iptables rules")

	iptables_rules = f"""
	NON_TOR="{NON_TOR_RNG}"
	TOR_UID={subprocess.getoutput('id -ur debian-tor')}
	TRANS_PORT="{TOR_TRANS_PORT}"

	iptables -F
	iptables -t nat -F

	iptables -t nat -A OUTPUT -m owner --uid-owner $TOR_UID -j RETURN
	iptables -t nat -A OUTPUT -p udp --dport 53 -j REDIRECT --to-ports {TOR_DNS_PORT}
	for NET in $NON_TOR 127.0.0.0/9 127.128.0.0/10; do
	 iptables -t nat -A OUTPUT -d $NET -j RETURN
	done
	iptables -t nat -A OUTPUT -p tcp --syn -j REDIRECT --to-ports $TRANS_PORT

	iptables -A OUTPUT -m state --state ESTABLISHED,RELATED -j ACCEPT
	for NET in $NON_TOR 127.0.0.0/8; do
	 iptables -A OUTPUT -d $NET -j ACCEPT
	done
	iptables -A OUTPUT -m owner --uid-owner $TOR_UID -j ACCEPT
	iptables -A OUTPUT -j REJECT
	"""

	execute(iptables_rules)
	log("Are we connected to Tor?.. ", "")
	if not check_tor():
		logapp(f"{font.RED}[no]{font.ENDC}")
		log(f"{font.CRIT}CRITICAL: we are NOT connected to Tor network! Reverting changes...{font.ENDC}")
		stop_tor_proxy()
		return False
	logapp(f"{font.GREEN}[yes]{font.ENDC}")
	log("Fetching current IP")
	log(f"Current IP is {font.GREEN}{ip()}{font.ENDC}")
	return True

def stop_tor_proxy():
	log(f"{font.RED}Restoring system defaults and shutting down onion router{font.ENDC}")
	check_root()
	log(f"Restoring DNS '{FileConfigResolv}' file")
	execute(f"mv '{FileConfigResolv}.bak' '{FileConfigResolv}'")
	log(f"Flushing iptables, resetting to default")
	IpFlush = """
	iptables -P INPUT ACCEPT
	iptables -P FORWARD ACCEPT
	iptables -P OUTPUT ACCEPT
	iptables -t nat -F
	iptables -t mangle -F
	iptables -F
	iptables -X
	"""
	execute(IpFlush)
	log("Freeing tor control port")
	execute(f"sudo fuser -k {TOR_CONTROL_PORT}/tcp > /dev/null 2>&1")
	# TODO: stop tor?
	log("Restarting Network Manager")
	execute('service network-manager restart')
	time.sleep(3)
	# R u rly want make request 2 some proprietary service without any proxying?
	#log("Fetching current IP")
	#log(f"Current IP is {font.GREEN}{ip()}{font.ENDC}")

def switch_exit_node():
	log(f"{font.YELLOW}Requesting new Tor exit node{font.ENDC}")
	check_root()
	if not check_tor():
		log(f"{font.CRIT}CRITICAL: you are not connected to Tor network{font.ENDC}")
		return
	log("Fetching current IP")
	log(f"Current IP is {font.GREEN}{ip()}{font.ENDC}")
	log("Checking tor pid... ", "")
	if not subprocess.getoutput('id -ur debian-tor').isdigit():
		log(f"{font.CRIT}seems like there is no tor process running! Aborting...{font.ENDC}")
		sys.exit(2)
	logapp(f"{font.GREEN}[OK]{font.ENDC}")
	log("Please wait...")
	time.sleep(7)
	log("Requesting new circuit... ", "")
	with Controller.from_port(port=TOR_CONTROL_PORT) as controller:
		controller.authenticate()
		controller.signal(Signal.NEWNYM)
	logapp(f"{font.GREEN}[done]{font.ENDC}")
	log("Fetching updated IP")
	log(f"New IP is {font.GREEN}{ip()}{font.ENDC}")

def show_connection_info():
	logo()
	log(f"{font.BG_BLUE + font.WHITE}Tor status:{font.ENDC} ", "")
	if not check_tor():
		logapp(f"{font.RED}DISCONNECTED{font.ENDC}")
		return
	logapp(f"{font.GREEN}CONNECTED{font.ENDC}")
	log(f"{font.BG_BLUE + font.WHITE}IP:{font.ENDC} {font.GREEN}{ip()}{font.ENDC}\n")



if __name__ == "__main__":
	signal.signal(signal.SIGINT, sigint_handler)
	if len(sys.argv) <= 1:
		usage()
	try:
		(opts, args) = getopt.getopt(sys.argv[1:], "sxrih", [
			"start", "stop", "switch", "info", "help"])
	except:
		usage()
		sys.exit(3)
	if not opts:
		usage()
		sys.exit(3)
	for (o, a) in opts:
		if o in ("-s", "--start"):
			if setup_tor_proxy():
				log(f"{font.BLUE}>>>{font.ENDC} {font.GREEN}Now you have +100 anonimity points!{font.ENDC} {font.BLUE}<<<{font.ENDC}")
		elif o in ("-x", "--stop"):
			stop_tor_proxy()
			log(f"{font.BLUE}>>>{font.ENDC} {font.RED}Bye, anonymity, bye!{font.ENDC} {font.BLUE}<<<{font.ENDC}")
		elif o in ("-r", "--switch"):
			switch_exit_node()
		elif o in ("-i", "--info"):
			show_connection_info()
		elif o in ("-h", "--help"):
			usage()
		else:
			usage()