dnsdb-domain

#!/usr/bin/env python3

###########
# IMPORTS #
###########

import os
import sys
import argparse
import socket
import json
from multiprocessing import Pool
#from multiprocessing.dummy import Pool  # utilise threads rather than subprocesses
import signal
import requests
from io import StringIO

####################
# GLOBAL VARIABLES #
####################

global url
global addresses


#############
# FUNCTIONS #
#############


def dnsdb_lookup(domain):
    headers = {'Accept': 'application/json'}
    response = requests.get("%s/rrset/name/*.%s" % (url, domain), headers=headers)
    if "no results found for query" in response.text:
        return
    data = StringIO(response.text)
    for line in data:
        jsonobj = json.loads(line)
        rrtype = str(jsonobj['rrtype'])
        host = str(jsonobj['rrname'])[:-1] # slice the trailing dot
        if rrtype ==  "A":
            address = str(jsonobj['rdata'][0])
            if addresses is None or address in addresses:
                sys.stdout.write('%s,%s\n' % (address, host))
                sys.stdout.flush()
        elif rrtype == "CNAME":
            cname = str(jsonobj['rdata'][0])[:-1]
            #sys.stdout.write('%s => (CNAME) %s\n' % (host, cname))
        else:
            #sys.stdout.write('%s => (%s) %s\n' % (host, rrtype, ", ".join(jsonobj['rdata'])))
            pass


def initializer():
    """Ignore CTRL+C in the worker process."""
    #signal.signal(signal.SIGINT, signal.SIG_IGN)


########
# MAIN #
########

if __name__ == '__main__':
    desc = 'Obtain observed entries from DNSDB for the supplied domains and output results in CSV format.'

    parser = argparse.ArgumentParser(description=desc)
    parser.add_argument('-f', '--filter',
                        action='store',
                        help='a list of IP addresses to filter against, only matching results are printed',
                        metavar='FILE',
                        default=None)
    parser.add_argument('file',
                        nargs='?',
                        type=argparse.FileType('r'),
                        action='store',
                        help='file containing a list of domains split by a newline, otherwise read from STDIN',
                        metavar='FILE',
                        default=sys.stdin)
    args = parser.parse_args()

    # Check for DNSDB env
    try:
        global url
        url = os.environ['DNSDB']
        if not url:
            sys.stderr.write("Error: DNSDB environment variable is emtpty, unable to obtain server url, please set accordingly.\n")
            exit(1)
    except KeyError:
        sys.stderr.write("Error: DNSDB environment variable not set, unable to obtain server url, please set accordingly.\n")
        exit(1)

    # compile filter (if supplied)
    global addresses
    if args.filter:
        with open(args.filter) as fp:
            addresses = [line.strip() for line in fp if len(line.strip())>0 and line[0] != '#']
    else:
        addresses = None

    # compile list of domains to brute force
    try:
        domains = [line.strip() for line in args.file]
    except KeyboardInterrupt:
        exit()

    # remove duplicates and sort
    domains = list(set(domains))
    domains = sorted(domains)

    pool = Pool(processes=10, initializer=initializer)
    try:
        pool.map(dnsdb_lookup, domains)
        pool.close()
        pool.join()
    except KeyboardInterrupt:
        pool.terminate()
        pool.join()