Merge pull request #12 from CZ-NIC/master

Checks for open resolvers in the list of IPs.
pull/14/head
Alexandre Dulaunoy 2016-12-09 09:20:26 +01:00 committed by GitHub
commit 04f4797f64
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#!/usr/bin/env python3
# Tool to check for openresolvers (from list of source IP).
#
# Dragon Research Group project
#
# Software is free software released under the "Modified BSD license"
#
# Copyright (c) 2015 Alexandre Dulaunoy - a@foo.be
#
# Has been modified by Edvard Rejthar, CSIRT.cz at MISP Hackathon 7 Dec 2016
#
#
import os, sys, argparse, redis, datetime, ipdb, json, threading, jsonpickle
from dns.resolver import Resolver, NXDOMAIN, NoNameservers, Timeout
from urllib.request import urlopen
from netaddr import IPAddress, AddrFormatError
import logging
logging.basicConfig(level=logging.DEBUG, format='%(message)s')
logger = logging.getLogger('openresolverchecker')
__help__ = """
Check the list of IP/domains agains an IP to see where is open resolvers.
Examples:
./openresolverchecker.py
./openresolverchecker.py --max 2000 --out save.json --include-timeouts
./openresolverchecker.py -v -o save.json --type TXT --query resolvertest.switch.ch "resolver test ok"
./openresolverchecker.py -v -o save.json --type A --query seznam.cz 77.75.77.53 --input ../list.json --max 100
"""
DEFAULT_QUERY, DEFAULT_IP = "resolvertest.switch.ch", "resolver test ok"
MISP_WARNING_LIST = "https://raw.githubusercontent.com/MISP/misp-warninglists/master/lists/public-dns-v4/list.json"
class OpenResolverChecker:
def __init__(self, ips, query = DEFAULT_QUERY, expected = DEFAULT_IP, threadnum = 500, verbose = 0, recordType = "TXT", includeTimeouts = False ):
self.resolver = Resolver()
self.resolver.timeout=1
self.resolver.lifetime=1
self.query = query
self.expected = expected
self.openresolvers = [] # [address, ...]
self.errors = [] # [(address, errcode), ...]
self.ips = ips
self.threadnum = threadnum
self.verbose = verbose
self.recordType = recordType
self.includeTimeouts = includeTimeouts
def _worker(cls,num, this):
""" Worker thread checks if the IP is an Open resolver. """
while True:
try:
ip = this.ips.pop()
except IndexError:
return False
ts = str(datetime.datetime.utcnow())
try:
IPAddress(ip) # check
addresses = [ip]
except AddrFormatError:
addresses = []
try:
answer = dns.resolver.query(ip, 'AAAA')
for data in answer:
addresses.append(data)
answer = dns.resolver.query(ip, 'A')
for data in answer:
addresses.append(data)
except:
#logging.warning("Cant translate to the IP: {}".format(ip))
this.errors.append((ip, "untranslatable"))
if this.verbose > 0:
print("Left:{} (Worker {}) {} {}".format(len(this.ips), num, "untranslatable", ip))
continue
for ip in addresses:
passed, msg = this.check(address=ip)
#if passed:
#this.openresolvers.append(ip)
#logline = ts+" - Open resolver at "+ip+" "+str(tst)
#else:
#logline = "{} closed".format(ip)
if this.verbose > 0:
print("Left:{} (Worker {}) {} {}".format(len(this.ips), num, msg, ip))
def launch(self):
""" Launch analysis in threads. """
threads = []
for i in range(self.threadnum):
th = threading.Thread(target=self._worker, args=(i,self))
threads.append(th)
th.start()
for x in threads:
x.join()
return self.openresolvers
def check(self, address=None):
""" False : not an openresolver
True is an open resolver
(True, ip) is an open resolver and includes the non expected A record """
if address is None:
return None
self.resolver.nameservers=[address]
try:
#print("QUERY",self.query, self.recordType)
answer = self.resolver.query(self.query, self.recordType)
result = next(answer.__iter__()).to_text().strip('"')
if result == self.expected:
self.openresolvers.append(address)
return (True, "*** open resolver")
else:
self.errors.append((address, "Wrong answer: {}".format(txt)))
return (False, "Wrong answer: {}".format(txt))
except Timeout as e:
if not self.includeTimeouts:
return (False, "Timeout")
else:
ex = e
except Exception as e:
ex = e
# NXDOMAIN = lies that the know domain does not exist
# NoNameservers = Refused they claim to be but are not. Ex ns1.eurodns.com", 80.92.65.2
# any other reason
pass
self.errors.append((address, ex.__class__.__name__))
return (False, ex.__class__.__name__)
if __name__ == "__main__":
# command line args
parser = argparse.ArgumentParser(description=__help__, formatter_class=argparse.RawTextHelpFormatter)
parser.add_argument('-q','--query', help='<query> <expected ip> EX: {} {}'.format(DEFAULT_QUERY, DEFAULT_IP),nargs=2, default=(DEFAULT_QUERY, DEFAULT_IP))
parser.add_argument('-o','--out', help='output file to store the list of open resolvers')
parser.add_argument('-v','--verbose', help='verbose output', action="count", default = 0)
parser.add_argument('--type', help='Specify the type of record we\'re checking. Default is TXT record but you might want to use an A record.', default="TXT")
parser.add_argument('--include-timeouts', help='Include timeout exception to error results. Normally, only Nxdomain and NoNameservers exceptions are treated as errors.', action="store_true")
parser.add_argument('-m','--max', help='max open resolvers to check (IE. only first 100)', type=int)
parser.add_argument('-t','--threadnum', help='thread number (default 500)', type=int, default=500)
parser.add_argument('-i','--input', help="Source file in the format: {'list':[ip, domain...]}. If no file is given, MISP "+MISP_WARNING_LIST+" will be used instead.", default=None)
args = parser.parse_args()
# load resolvers list
if args.input:
try: # local file
with open(args.input) as f:
sourceFile = json.load(f)
except FileNotFoundError:
sys.exit("File {} not found.".format(args.input))
else: # load from github
print("Downloading the list from: {}".format(MISP_WARNING_LIST))
response = urlopen(MISP_WARNING_LIST)
sourceFile = json.loads(response.read().decode('utf-8'))
ips = sourceFile["list"]
if args.max:
ips = ips[:args.max]
count = len(ips)
if not count:
print("Nothing to be checked, empty list.")
quit()
# launch resolvers
orc = OpenResolverChecker(ips, args.query[0], args.query[1], threadnum = args.threadnum, verbose = args.verbose, recordType=args.type, includeTimeouts = args.include_timeouts)
orc.launch()
# work with results
if args.out: # save to file
with open(args.out, "w") as f:
sourceFile.update({"timestamp": str(datetime.datetime.utcnow()),
"openresolvers": orc.openresolvers,
"ip-checked": count,
"open-ratio": (len(orc.openresolvers)/count),
"query": args.query[0],
"query-expected-ip": args.query[1],
"query-record-type": args.type,
"errors": orc.errors
})
json.dump(sourceFile, f, indent=4, sort_keys = True)
else: # print to stdout
print("Valid resolvers:")
print(orc.openresolvers)
print("Resolvers checked: {}, opens: {} ({} %), errors {} ({} %)".format(count, len(orc.openresolvers), (len(orc.openresolvers)/count)*100 ,len(orc.errors),(len(orc.errors)/count*100)))