def _add_authority(domain, auth_list):
"""
Given a domain and an authority set,
this function will add the UH DNS nameservers to the set if they don't already exist.
:param domain: Domain to be authoritative over.
:param auth_list: Auth set to add to.
"""
record1 = dnslib.RR(rname=domain,
rtype=dnslib.QTYPE.NS,
rdata=dnslib.NS("ns1.uh-dns.com"),
ttl=3600)
record2 = dnslib.RR(rname=domain,
rtype=dnslib.QTYPE.NS,
rdata=dnslib.NS("ns2.uh-dns.com"),
ttl=3600)
if record1 not in auth_list:
auth_list.append(record1)
if record2 not in auth_list:
auth_list.append(record2)
def gen_response(qt, qn):
global serving_domains
prefix_ = list(
filter(lambda d: qn == d or qn.endswith('.' + d), serving_domains))
if len(prefix_) != 1:
# print("Error: invalid request domain {} in {}".format(qn, serving_domains))
return None
prefix = prefix_[0]
print('REQ: ', qt, qn)
if qt == 'SOA':
generated_soa = dnslib.SOA(
mname="todo." + domain_text,
rname="*****@*****.**",
times=(
201307231, # serial number
10000, # refresh
2400, # retry
604800, # expire
3600, # minimum
))
return RR(rname=prefix,
rtype=QTYPE.SOA,
rclass=1,
ttl=86400,
rdata=generated_soa)
# return {"mname": "todo."+domain_text, "rname": "*****@*****.**", "serial": "10", "refresh": 3600, "retry": 600, "expire": 604800, "minimum": 86400}
elif qt == 'A':
requested_ip = qn[:len(qn) - len(prefix)].strip('.')
if not re.match(r'^(?:[0-9]{1,3}\.){3}[0-9]{1,3}$', requested_ip):
print("Invalid requested_ip: " + requested_ip)
return None
generated_a = dnslib.A(requested_ip)
return RR(rname=qn,
rtype=QTYPE.A,
rclass=1,
ttl=86400,
rdata=generated_a)
elif qt == 'NS':
generated_ns = dnslib.NS(ns_ipaddr)
return RR(rname=prefix,
rtype=QTYPE.NS,
rclass=1,
ttl=86400,
rdata=generated_ns)
else:
print("Invalid qt=" + qt)
return None
def _ns_search(record, rr_list, addi_list):
"""
Searches and adds any NS records for the domain.
:param record: Overall record for domain
:param rr_list: Current record list for the domain
:param addi_list: Additional list for the domain
"""
try:
ns_record = record["NS"]
ttl = int(ns_record["ttl"])
for ns in ns_record["value"]:
rr_list.append(dnslib.RR(rname = record["domain"],
rtype = dnslib.QTYPE.NS,
rdata = dnslib.NS(label = ns),
ttl = ttl))
_add_additional(addi_list)
except:
pass
def __init__(self, upstream):
super().__init__(upstream, 53, 5)
if confs.SOA_MNAME and confs.SOA_RNAME:
self.SOA = dnslib.SOA(
mname=DNSLabel(confs.SOA_MNAME),
rname=DNSLabel(confs.SOA_RNAME.replace(
'@', '.')), # TODO: . before @ should be escaped
times=(
confs.SOA_SERIAL, # serial number
60 * 60 * 1, # refresh
60 * 60 * 2, # retry
60 * 60 * 24, # expire
60 * 60 * 1, # minimum
))
else:
self.SOA = None
if confs.NS_SERVERS:
self.NS = [dnslib.NS(i) for i in confs.NS_SERVERS]
else:
self.NS = []
def add_answer_to_query(required_data, query):
qtype = query.q.qtype
q = query.q
# Для каждого типа запроса добавляем интересующий ответ
if qtype == dnslib.QTYPE.A:
# Добавляем все A адреса
for addr in required_data.addresses:
query.add_answer(
dnslib.RR(rname=q.qname,
rclass=q.qclass,
rtype=q.qtype,
ttl=required_data.remain_ttl(),
rdata=dnslib.A(addr)))
if qtype == dnslib.QTYPE.AAAA:
# Добавляем все AAAA адреса
for addr in required_data.addresses:
query.add_answer(
dnslib.RR(rname=q.qname,
rclass=q.qclass,
rtype=q.qtype,
ttl=required_data.remain_ttl(),
rdata=dnslib.AAAA(addr)))
if qtype == dnslib.QTYPE.NS:
# Добавляем все NS серверы
for addr in required_data.servers:
query.add_answer(
dnslib.RR(rname=q.qname,
rclass=q.qclass,
rtype=q.qtype,
ttl=required_data.remain_ttl(),
rdata=dnslib.NS(addr)))
if qtype == dnslib.QTYPE.PTR:
# Добавляем PTR
query.add_answer(
dnslib.RR(rname=q.qname,
rclass=q.qclass,
rtype=q.qtype,
ttl=required_data.remain_ttl(),
rdata=dnslib.PTR(required_data.name)))
def resolve(self, request, handler):
question = request.get_q()
req_name = str(question.get_qname())
# TXT = 16
reply = request.reply()
pivot = req_name.rfind("_tox.")
if pivot == -1:
reply.header.rcode = dnslib.RCODE.NXDOMAIN
return reply
name = req_name[:pivot].rstrip(".")
suffix = req_name[pivot:]
domain = suffix[5:].rstrip(".")
if question.qtype == 16:
if not name and domain in self.workable_domains:
data = self.cryptocore.public_key.encode("ascii")
reply.add_answer(
dnslib.RR(req_name, 16, ttl=0, rdata=dnslib.TXT(data)))
return reply
first_try = self.try_tox3_resolve(reply, name, domain, req_name)
if not first_try:
return self.try_tox1_resolve(reply, name, domain, req_name)
else:
return first_try
elif question.qtype == 2:
reply.add_answer(
dnslib.RR(req_name, 2, ttl=86400, rdata=dnslib.NS(self.home)))
return reply
else:
reply.header.rcode = dnslib.RCODE.NXDOMAIN
return reply
return reply
def resolve(self, request, handler):
question = request.get_q()
req_name = str(question.get_qname())
# TXT = 16
reply = request.reply()
suffix = "._tox.{0}".format(self.ireg)
if question.qtype != 16 and not req_name.endswith(self.ireg):
reply.header.rcode = dnslib.RCODE.NXDOMAIN
return reply
if question.qtype == 16:
if req_name == suffix[1:]:
reply.add_answer(dnslib.RR(req_name, 16, ttl=0,
rdata=dnslib.TXT(self.cryptocore.public_key.encode("ascii"))))
return reply
if not req_name.endswith(suffix):
reply.header.rcode = dnslib.RCODE.NXDOMAIN
return reply
user_name = req_name[:req_name.rfind(suffix)]
if len(user_name) > NAME_LIMIT_HARD and user_name[0] == "_":
encrypted = user_name.replace(".", "")[1:]
try:
b = notsecure32_decode(encrypted)
nonce = b[:4] + (b"\0" * 20)
ck = b[4:36]
payload = b[36:]
name = self.cryptocore.dsrep_decode_name(ck, nonce, payload)
except Exception:
print("error >_<")
reply.header.rcode = dnslib.RCODE.NXDOMAIN
return reply
rec = self.store.get(name.decode("utf8"))
if not rec:
reply.header.rcode = dnslib.RCODE.NXDOMAIN
return reply
base = b"v=tox3;id="
if rec.pin:
r_payload = "{0}{1}{2}".format(rec.public_key, rec.pin,
rec.checksum)
else:
r_payload = "{0}00000000{1}".format(rec.public_key,
rec.checksum)
msg = binascii.unhexlify(r_payload)
nonce_reply = b[:4] + b"\x01" + (b"\0" * 19)
ct = self.cryptocore.dsrec_encrypt_key(ck, nonce_reply, msg)
key_part = notsecure32_encode(ct)
reply.add_answer(dnslib.RR(req_name, 16, ttl=0,
rdata=dnslib.TXT(b"".join((base, key_part)))))
return reply
else:
rec = self.store.get(user_name)
if not rec:
reply.header.rcode = dnslib.RCODE.NXDOMAIN
return reply
else:
reply.add_answer(dnslib.RR(req_name, 16, ttl=0,
rdata=dnslib.TXT(rec.record(0)
.encode("utf8"))))
return reply
elif question.qtype == 6:
self.update_soa()
reply.add_answer(self.soa)
return reply
elif question.qtype == 2:
for name in self.authority_list:
reply.add_answer(dnslib.RR(req_name, 2, ttl=86400,
rdata=dnslib.NS(name.encode("utf8"))
))
return reply
elif question.qtype == 1 and self.home_addresses:
for ip in self.home_addresses:
reply.add_answer(dnslib.RR(req_name, 1, ttl=3600,
rdata=dnslib.A(ip)))
elif question.qtype == 28 and self.home_addresses_6:
for ip in self.home_addresses_6:
reply.add_answer(dnslib.RR(req_name, 28, ttl=3600,
rdata=dnslib.AAAA(ip)))
else:
reply.header.rcode = dnslib.RCODE.NXDOMAIN
return reply
return reply
class BaseRequestHandler(socketserver.BaseRequestHandler):
fIP = {}
D = DomainName('0h0.us.')
IP = '18.219.234.8'
TTL = 60 * 1
soa_record = dnslib.SOA(
mname=D.ns1, # primary name server
times=(
22118400, # serial number
60 * 60 * 1, # refresh
60 * 60 * 3, # retry
1 * 1 * 1, # expire
1 * 1 * 1, # minimum
))
ns_records = [dnslib.NS(D.ns1), dnslib.NS(D.ns2)]
records = {
D: [dnslib.A(IP), dnslib.AAAA((0, ) * 16), soa_record] + ns_records,
D.ns1: [
dnslib.A(IP)
], # MX and NS records must never point to a CNAME alias (RFC 2181 section 10.3)
D.ns2: [dnslib.A(IP)]
}
def progressBar(self, c, tot, status):
bar = 40
filled = int(round(bar * (tot - c) / float(tot)))
pct = round(100.0 * (tot - c) / float(tot), 1)
barstr = '=' * filled + '-' * (bar - filled)
sys.stdout.write('[%s] %s%s ...%s\r' % (barstr, pct, '%', status))
sys.stdout.flush()
def processRequest(self, request):
reply = dnslib.DNSRecord(dnslib.DNSHeader(id=request.header.id,
qr=1,
aa=1,
ra=1),
q=request.q)
qname = request.q.qname
qn = str(qname)
qtype = request.q.qtype
qt = dnslib.QTYPE[qtype]
if qn == self.D or qn.endswith('.' + self.D):
for name, rrs in self.records.items():
if name == qn:
for rdata in rrs:
rqt = rdata.__class__.__name__
if qt in ['*', rqt]:
reply.add_answer(
dnslib.RR(rname=qname,
rtype=getattr(dnslib.QTYPE, rqt),
rclass=1,
ttl=self.TTL,
rdata=rdata))
for rdata in self.ns_records:
reply.add_ar(
dnslib.RR(rname=self.D,
rtype=dnslib.QTYPE.NS,
rclass=1,
ttl=self.TTL,
rdata=rdata))
reply.add_auth(
dnslib.RR(rname=self.D,
rtype=dnslib.QTYPE.SOA,
rclass=1,
ttl=self.TTL,
rdata=self.soa_record))
for question in request.questions:
if (question.qtype == dnslib.QTYPE.TXT):
#only process TXT record requests
content = str(question.qname)[:-1]
if content.endswith(self.D[:-1]):
content = content[:-len(self.D[:-1]) - 1]
key = content[:4]
if key in self.fIP:
content = str(content[4:])
self.fIP[key][3] += content
self.fIP[key][1] -= len(content)
#print(key, content,len(content),self.fIP[key][1] )
#print("Left: "+str(self.fIP[sIP][1]))
self.progressBar(
self.fIP[key][1], self.fIP[key][4], "Receiving '" +
self.fIP[key][0] + "' with index " + key)
reply.add_answer(
dnslib.RR(rname=qname,
rtype=question.qtype,
rclass=1,
ttl=self.TTL,
rdata=dnslib.TXT(content)))
#reply.add_answer(dnslib.RR(rname=qname, rtype=question.qtype, rclass=1, ttl=self.TTL, rdata=dnslib.TXT("OK")))
if (self.fIP[key][1] == 0):
#we have received the entire file. Time to write it.
content_decoded = base64.standard_b64decode(
self.fIP[key][3])
with open(self.fIP[key][0], 'wb') as newfile:
newfile.write(content_decoded)
hashedWord = md5(content_decoded).hexdigest()
if (self.fIP[key][2] == hashedWord):
print("\nFile successfully received")
reply.add_answer(
dnslib.RR(rname=qname,
rtype=question.qtype,
rclass=1,
ttl=self.TTL,
rdata=dnslib.TXT("OK")))
else:
print("\nFile received but failed hash:")
reply.add_answer(
dnslib.RR(rname=qname,
rtype=question.qtype,
rclass=1,
ttl=self.TTL,
rdata=dnslib.TXT("FAIL HASH")))
del self.fIP[key]
else:
# new connection. we expect a file name
print("New file:", content)
parts = content.split("|")
if (len(parts) == 3):
#we have valid request
print("new file upload: ", content)
self.fIP[parts[2][:4]] = [
os.path.basename(parts[0]),
int(parts[1]), parts[2], "",
int(parts[1])
]
reply.add_answer(
dnslib.RR(rname=qname,
rtype=question.qtype,
rclass=1,
ttl=self.TTL,
rdata=dnslib.TXT("OK")))
else:
reply.add_answer(
dnslib.RR(rname=qname,
rtype=question.qtype,
rclass=1,
ttl=self.TTL,
rdata=dnslib.A(self.IP)))
#print("responding:",reply)
return reply.pack()
def py3dns(serverip='', serverport=0):
class DNSify(str):
def __getattr__(self, item):
return DNSify(item + '.' + self)
def get_lan_ip4(forcelocalhost=False):
if forcelocalhost: return '127.0.0.1'
s = dnslib.socket.socket(dnslib.socket.AF_INET,
dnslib.socket.SOCK_DGRAM)
try:
s.connect(('10.255.255.255', 0))
IP = s.getsockname()[0]
except:
IP = '127.0.0.1'
finally:
s.close()
return IP
def is_domain_blacklisted(sqname, domain_blacklist):
for test_domain in domain_blacklist:
if test_domain in sqname:
return True
return False
# Init server settings
killcommand = 'stop.py3dns.now'
serve_forever = True
udp_buffer_size = 1024
server_name = dnslib.socket.getfqdn()
server_ip = get_lan_ip4()
if serverip: server_ip = serverip
reverse_server_ip = '.'.join(reversed(
server_ip.split('.'))) + '.in-addr.arpa'
server_port = 53
if serverport: server_port = int(serverport)
server_protocol = 'UDP'
public_dns_resolvers = [
'91.239.100.100', '89.233.43.71', '8.8.8.8', '8.8.4.4'
]
# Init simple host cache
host_cache = {}
host_cache[server_ip] = server_name
# Init blacklists
use_blacklists = True
domain_blacklist = make_domain_blacklist()
ipaddr_blacklist = make_ipaddr_blacklist()
rpz_domain = DNSify('getthefuckaway.net')
rpz_ip4 = '10.20.30.40'
rpz_ip6 = '10:20:30:40:50:60:70:80'
# Init UDP socket server
udpsrv = dnslib.socket.socket(dnslib.socket.AF_INET,
dnslib.socket.SOCK_DGRAM)
udpsrv.bind((server_ip, server_port))
udpsrv.setblocking(False)
# Init external resolvers
external_resolver = dns.resolver.Resolver()
external_resolver_cache = dns.resolver.Cache(cleaning_interval=600.0)
external_resolver.cache = external_resolver_cache
external_resolver.nameservers = public_dns_resolvers
external_resolver.retry_servfail = False
external_resolver.port = 53
##external_resolver.timeout = 1.0
##external_resolver.lifetime = 2.0
# Timestamp UTC
now = datetime.datetime.utcnow().strftime('%Y-%m-%d %H:%M:%S.%f')
# App Header
print('+' + ('-' * 71))
print('| PY3DNS v/1.0 by BikerDroid')
print('+' + ('-' * 71))
print('| Server :', server_name)
print('| Address :', server_ip)
print('| Port Used :', server_port)
print('| Protocol :', server_protocol)
print('| Recv Size :', udp_buffer_size, 'bytes')
print('| Solvers :',
str(public_dns_resolvers).strip("[]").replace("'", ""))
print('+' + ('-' * 71))
print('| Stop PY3DNS by sending "nslookup ' + killcommand + ' ' +
server_ip + '"')
print('+' + ('-' * 71))
print(now, ': Ready to serve...')
# Main Loop
while serve_forever:
# Clear vars
sres = sip4 = sip6 = smx = scname = sns = stxt = sptr = ssoa = sany = hostip = ''
# Main: Get client request, add hostip and host name to host_cache
try:
data, addr = udpsrv.recvfrom(udp_buffer_size)
hostip = str(addr[0])
if not hostip in host_cache:
host_cache[hostip] = dnslib.socket.getfqdn(
str(dnslib.socket.gethostbyaddr(hostip)[0]))
now = datetime.datetime.utcnow().strftime(
'%Y-%m-%d %H:%M:%S.%f') # UTC
except:
continue
# Client request -> id, qname (domain), qtype (A,AAAA,MX etc)
request = dnslib.DNSRecord.parse(data)
qid = request.header.id
qname = request.q.qname
qtype = request.q.qtype
slabel = str(qname.label)
sqname = str(qname)
sqtype = str(dnslib.QTYPE[qtype])
# Rem this line if rpz_domain is to overwrite
# blacklisted domains with their real names.
sdomain = sqname
# Dirty trick to shut down server from commandline:
# Syntax : nslookup stop.dns.srv <server_ip>
# Example: nslookup stop.dns.srv 127.0.0.1
# Must be before external_resolver.query()
if sqname.rstrip('.') == killcommand:
serve_forever = False
continue
# Dirty Reverse Lookup of local server
# Allows requesting client to get server_name
if qtype == dnslib.QTYPE.PTR:
if sqname.rstrip('.') == reverse_server_ip:
reply = dnslib.DNSRecord(header=dnslib.DNSHeader(id=qid,
qr=1,
aa=1,
ra=1,
rcode=0),
q=dnslib.DNSQuestion(sqname,
qtype)).reply()
reply.add_answer(
dnslib.RR(sqname,
dnslib.QTYPE.PTR,
rdata=dnslib.PTR(server_name),
ttl=3600))
udpsrv.sendto(reply.pack(), addr)
print(now, ':', sqname, '|', sqtype, '=', qtype, '|',
server_name, '|', hostip, '=', host_cache[hostip])
continue
# Get DNS record from public_dns_resolvers.
# This section can be changed to serve from
# own database, stationary files or similar.
try:
if not sqname.rstrip('.') in domain_blacklist:
external_resolver_result = external_resolver.query(
sqname.rstrip('.'), sqtype)
found = True
except:
print(now, '> qtype', sqtype,
'(' + str(qtype) + ') was not found for', sqname)
external_resolver_result = []
sres = sip4 = sip6 = ''
found = False
if not found:
# Create DNSRecord Header reply: rcode = 5 (Query Refused). See RFC2136 for rcode's.
reply = dnslib.DNSRecord(header=dnslib.DNSHeader(id=qid,
qr=1,
aa=1,
ra=1,
rcode=5),
q=dnslib.DNSQuestion(sdomain,
qtype)).reply()
else:
# Create DNSRecord Header reply: rcode = 0 (No Error)
reply = dnslib.DNSRecord(header=dnslib.DNSHeader(id=qid,
qr=1,
aa=1,
ra=1,
rcode=0),
q=dnslib.DNSQuestion(sdomain,
qtype)).reply()
# Add A record answer for domain and IP
# Filter blacklisted IP4/6 addresses.
if qtype == dnslib.QTYPE.A:
if is_domain_blacklisted(
sqname.rstrip('.'),
domain_blacklist): # Simple domain blacklist check
sres = sip4 = rpz_ip4
reply.add_answer(
dnslib.RR(sdomain,
dnslib.QTYPE.A,
rdata=dnslib.A(sip4),
ttl=60))
else:
for data in external_resolver_result:
sres = sip4 = str(data).strip()
if sip4:
if sip4 in ipaddr_blacklist: # Simple IP (4+6) blacklist check
sres = sip4 = rpz_ip4
reply.add_answer(
dnslib.RR(sdomain,
dnslib.QTYPE.A,
rdata=dnslib.A(sip4),
ttl=60))
# Add AAAA record answer for domain and IP
# Filter blacklisted IP4/6 addresses.
elif qtype == dnslib.QTYPE.AAAA:
if is_domain_blacklisted(
sqname.rstrip('.'),
domain_blacklist): # Simple domain blacklist check
sres = sip6 = rpz_ip6
reply.add_answer(
dnslib.RR(sdomain,
dnslib.QTYPE.AAAA,
rdata=dnslib.AAAA(sip6),
ttl=60))
else:
for data in external_resolver_result:
sres = sip6 = str(data).strip()
if sip6:
if sip6 in ipaddr_blacklist: # Simple IP (4+6) blacklist check
sres = sip6 = rpz_ip6
reply.add_answer(
dnslib.RR(sdomain,
dnslib.QTYPE.AAAA,
rdata=dnslib.AAAA(sip6),
ttl=60))
# Add NS record answer for domain
elif qtype == dnslib.QTYPE.NS:
for data in external_resolver_result:
sres = sns = str(data).strip()
if sns:
reply.add_answer(
dnslib.RR(sdomain,
dnslib.QTYPE.NS,
rdata=dnslib.NS(sns),
ttl=60))
# Add MX record answer for domain and IP
elif qtype == dnslib.QTYPE.MX:
for data in external_resolver_result:
sres = smx = str(data).strip()
if smx:
reply.add_answer(
dnslib.RR(sdomain,
dnslib.QTYPE.MX,
rdata=dnslib.MX(smx),
ttl=60))
# Add CNAME record answer for domain
elif qtype == dnslib.QTYPE.CNAME:
for data in external_resolver_result:
sres = scname = str(data).strip()
if scname:
reply.add_answer(
dnslib.RR(sdomain,
dnslib.QTYPE.CNAME,
rdata=dnslib.CNAME(scname),
ttl=60))
# Add TXT record answer for domain
elif qtype == dnslib.QTYPE.TXT:
for data in external_resolver_result:
sres = stxt = str(data).strip()
if stxt:
reply.add_answer(
dnslib.RR(sdomain,
dnslib.QTYPE.TXT,
rdata=dnslib.TXT(stxt),
ttl=60))
# Add PTR record answer for domain
elif qtype == dnslib.QTYPE.PTR:
for data in external_resolver_result:
sres = sptr = str(data).strip()
if sptr:
reply.add_answer(
dnslib.RR(sdomain,
dnslib.QTYPE.PTR,
rdata=dnslib.PTR(sptr),
ttl=60))
# Add ANY record answer for domain
elif qtype == dnslib.QTYPE.ANY:
for data in external_resolver_result:
sres = sany = str(data).strip()
if sany:
reply.add_answer(
dnslib.RR(sdomain,
dnslib.QTYPE.ANY,
rdata=dnslib.ANY(sany),
ttl=60))
# Add SOA record answer for domain
elif qtype == dnslib.QTYPE.SOA:
for data in external_resolver_result:
if str(data).strip():
soa_data = str(data).strip().split(' ')
soa_mname = soa_data[0]
soa_rname = soa_data[1]
soa_serial = soa_data[2]
soa_refresh = soa_data[3]
soa_retry = soa_data[4]
soa_expire = soa_data[5]
soa_minimum = soa_data[6]
soa_time = (int(soa_serial), int(soa_refresh),
int(soa_retry), int(soa_expire),
int(soa_minimum))
sres = soa_mname + ',' + soa_rname + ',' + soa_serial + ',' + soa_refresh + ',' + soa_retry + ',' + soa_expire + ',' + soa_minimum
reply.add_answer(
dnslib.RR(sdomain,
dnslib.QTYPE.SOA,
rdata=dnslib.SOA(soa_mname, soa_rname,
soa_time),
ttl=60))
else:
# Unknown qtype - add CNAME as answer :)
reply.add_answer(
dnslib.RR(qname,
dnslib.QTYPE.CNAME,
rdata=dnslib.CNAME(server_name),
ttl=60))
# Send DNS reply to client address using UDP
udpsrv.sendto(reply.pack(), addr)
# Show status in console
print(now, ':', sqname, '|', sqtype, '=', qtype, '|', sres, '|',
hostip, '=', host_cache[hostip]) #,reply.pack()
# Shutting down
print(now, ': Shutting down...')
udpsrv.shutdown(0)
print(now, ': Done.')
def parse_server_config(server_config):
import copy
_server_config = copy.deepcopy(server_config)
dns_servers = _server_config.get('dns_servers', [])
for server in dns_servers:
# parse url
scheme, hostname, port = DNSServerLoader.parse_url(server['url'])
server['scheme'] = scheme
server['hostname'] = hostname
server['port'] = port
# parse rules
for rule in server['rules']:
rtype = rule['type']
if rule['domain-type'] in ('FQDN', 'PREFIX', 'SUFFIX'):
rule['domain'] = DNSLabel(rule['domain'])
if rtype == 'FORWARD':
_scheme, _hostname, _port = DNSServerLoader.parse_url(rule['value'])
rule['pvalue'] = {
'scheme': _scheme,
'hostname': _hostname,
'port': _port,
'url': _scheme + '://' + _hostname + ':' + str(_port)
}
elif rtype in ('A', 'CNAME', 'MX', 'NS', 'PTR', 'AAAA', 'SRV', 'SOA'):
if isinstance(rule['value'], six.string_types):
rule['value'] = [rule['value']]
if rtype == 'A':
rule['pvalue'] = [dnslib.A(item) for item in rule['value']]
elif rtype == 'CNAME':
rule['pvalue'] = [dnslib.CNAME(DNSLabel(item)) for item in rule['value']]
elif rtype == 'MX':
rule['pvalue'] = [dnslib.MX(DNSLabel(item)) for item in rule['value']]
elif rtype == 'NS':
rule['pvalue'] = [dnslib.NS(DNSLabel(item)) for item in rule['value']]
elif rtype == 'PTR':
rule['pvalue'] = [dnslib.PTR(DNSLabel(item)) for item in rule['value']]
elif rtype == 'AAAA':
rule['pvalue'] = [dnslib.AAAA(item) for item in rule['value']]
elif rtype == 'SRV':
srv_arr = []
for item in rule['value']:
item_arr = item.split(' ')
srv_arr.append(dnslib.SRV(
priority=num.safe_int(item_arr[0]),
weight=num.safe_int(item_arr[1]),
port=num.safe_int(item_arr[2]),
target=item_arr[3]))
rule['pvalue'] = srv_arr
elif rtype == 'SOA':
soa_arr = []
for item in rule['value']:
item_arr = item.split(' ')
soa_arr.append(dnslib.SOA(
mname=DNSLabel(item_arr[0]),
rname=DNSLabel(item_arr[1]),
times=(num.safe_int(t) for t in item_arr[2:]) # serial, refresh, retry, expire, minimun
))
rule['pvalue'] = soa_arr
return dns_servers
def dns_resolve(self, query, tcp):
"""
Resolves DNS request from one client at the time.
Encodes its actual data and forms DNS response from it.
"""
request = dns.DNSRecord.parse(query)
reply = request.reply()
domain = request.q.get_qname()
qtype = request.q.qtype
data = exf.domain_decode(str(domain), base64.urlsafe_b64decode)
# If encryption key is present - decode it for futher data decryption
if (len(request.questions) > 1):
enc_domain = str(request.questions[1].get_qname())
enc_key = exf.domain_decode(enc_domain, base64.urlsafe_b64decode)
# Descramble key
enc_key = exf.scramble(enc_key, (4, 12), True)
# Check if the key is scramble offset
if len(enc_key) < 3:
enc_key = tuple(enc_key)
data = exf.scramble(data, enc_key, True)
# Or AES decryption key
else:
enc_key = enc_key.decode()
data = exf.aes_decrypt(data, enc_key)
# reply.add_question(request.questions[1])
if DEBUG:
print_with_time("***", f"DNS QTYPE is {qtype}")
print_with_time("***", f"Original data length {len(data)} bytes")
print_with_time("***", f"{data[:24]}...")
data = base64.b64encode(data)
core_domain = deepcopy(domain)
# Get TLD domain from original object
core_domain.label = domain.label[-2:]
if (qtype == dns.QTYPE.A):
data = exf.ip_encode(data, False)
elif (qtype == dns.QTYPE.AAAA):
data = exf.ip_encode(data, True)
elif (qtype == dns.QTYPE.TXT):
data = [dns.TXT(data)]
elif (qtype == 10): # NULL type
data = [dns.RD(data)]
else:
data = exf.domain_encode(data, str(core_domain), base64.urlsafe_b64encode)
if (qtype == dns.QTYPE.CNAME):
data = [dns.CNAME(data)]
elif (qtype == dns.QTYPE.MX):
data = [dns.MX(data)]
elif (qtype == dns.QTYPE.NS):
data = [dns.NS(data)]
for rd in data:
reply.add_answer(dns.RR(str(domain), rtype=qtype, rdata=rd))
raw_reply = reply.pack()
# Truncate large (> 512 bytes) data for UDP payload
if (len(raw_reply) > exf.MAX_DNS_LEN and not tcp):
print_with_time("DNS", f"Response message is big! Truncate it...")
reply.header.set_tc(1)
raw_reply = reply.pack()[:exf.MAX_DNS_LEN]
print_with_time("DNS", f"Sending back the request in size {len(raw_reply)} bytes\n")
return raw_reply