#!/usr/bin/env python3
# -*- coding: utf-8 -*-

#####
# name: bulk-resolver.py
# author: daniel isaksen <d@duniel.no>
# purpose: pentesting
# description:
# 	bulk resolve FQDNs to IP addresses
# dependencies
# 	dnspython
#####

import sys
import json
import os.path
import argparse

try:
	import dns.exception

	import dns.resolver
	resolver = dns.resolver.Resolver()
	resolver.timeout = 5
	resolver.lifetime = 5
except:
	print("[ERR] You need to install the dependency dnspython!")
	sys.exit(1)

def resolve(host, verbose):
	try:
		return list(str(y) for y in resolver.query(host, "A"))
	except (dns.resolver.NoAnswer, dns.resolver.NXDOMAIN, dns.exception.Timeout) as e:
		if verbose:
			print("[DBG] failure resolving {0}: {1}".format(host, str(e)))

def prettyprint(type_, data):
	if type_ == "grep":
		for host, ips in data.items():
			for ip in ips:
				print("Hostname: {0}\tIP address: {1}".format(host, ip))
	elif type_ == "json":
		print(json.dumps(data, indent=4))
	elif type_ == "xml":
		print('<?xml version="1.0" encoding="UTF-8" ?>')
		print("<results>")
		for host, ips in data.items():
			print("\t<result>")
			print("\t\t<hostname>{}</hostname>".format(host))
			for ip in ips:
				print("\t\t<ip_address>{}</ip_address>".format(ip))
			print("\t</result>")
		print("</results>")

if __name__ == "__main__":
	parser = argparse.ArgumentParser("bulk-resolver.py", description="Bulk resolve domain names")

	parser.add_argument("host", type=str, nargs="*", help="Space or newline separated list of hosts to resolve")
	parser.add_argument("-f", "--file", type=str, help="File containing hosts to check")
	parser.add_argument("-o", "--output-format", type=str, default="grep", choices=["grep, json, xml"])
	parser.add_argument("-v", "--verbose", action="store_true", default=False, help="Verbose mode (debug)")

	args = parser.parse_args()

	hosts = []

	if args.host:
		for host in args.host:
			hosts.append(host)

	if args.file:
		try:
			with open(args.file, "r") as f:
				f = f.read()

				if len(f.split()) > 1:
					for host in f.split():
						hosts.append(host)
				elif len(f.split("\n")):
					for host in f.split("\n"):
						if host: # avoid newline
							hosts.append(host)
		except Exception as e:
			print("[ERR] File {} could not be read.".format(args.file))
			sys.exit(1)

	if not hosts:
		parser.print_help()
		sys.exit(1)

	ret = {}

	for host in hosts:
		ips = resolve(host, args.verbose)

		if ips:
			ret[host] = ips

	if not ret:
		print("[ERR] None of the specified hosts could be resolved.")
		sys.exit(0)

	prettyprint(args.output_format, ret)