====== Networking - DNS - DNS Response Crafter ======

===== Make lots of DNS requests in quick succession: =====

<code python>
import dns.resolver

resolver = dns.resolver.Resolver()for x in range(2, 10):
    for i in range(85, 200):
        try:
            print resolver.query(chr(i) * x + '.com', 'A')
        except:
            pass
</code>            

<WRAP info>
**NOTE:**

See: https://dnspython.readthedocs.io/en/latest/_modules/dns/resolver.html

</WRAP>

----

===== Craft Specific DNS requests =====

<code python>
import socket
from scapy . all  import *

UDP_IP_ADDRESS  = <IP−of−virtual−machine>
RESPONSE_IP =  '123.123.123.123'  # Can be any address.
UDP_PORT_NO = 53  # Bind to DNS port.
TTL = 86400  # Time to live in cache.
NAME_POINTER = "\xc0\x0c "  # Message compression rfc 1035 4.1.4910.

def CraftResponse(addr, data):
  dns = DNS(data)
  dnsrr =  DNSRR(rrname=NAMEPOINTER, ttl=TTL, rdata=RESPONSEIP)
  opt = DNSRROPT(rrname= '.' ,type= 'OPT' , rclass=512,
        extrcode=0, version=0, z=0, rdlen=0)
  
  return \ # Assemble and return packet.
    IP(dst=addr[0])/\
    UDP(dport=addr[1], sport=UDPPORTNO) /\
    DNS(id=dns.id, qr=1, aa=0, tc=0,
    rd=dns.rd, ra=1, z=0, ad=0, cd=0,
    qdcount=1, ancount=1, nscount=0, arcount=1,
    qd=dns.qd, an=dnsrr, ar=opt)
    
def main():
  # Set up and bind socket for UDP packets.
  s = socket.socket(socket.AFINET, socket.SOCKDGRAM)
  s.bind(UDPIPADDRESS, UDPPORTNO)
  print "Listening..."
  while 1:
    data, addr = s.recvfrom(65535)
    packet = CraftResponse(addr, data)
    send(packet, verbose=0)
    
if __name__ == 'main':
    main()
</code>