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