mirror of
https://github.com/samba-team/samba.git
synced 2024-12-24 21:34:56 +03:00
581d7a528e
Also, improve a variable name. Signed-off-by: Douglas Bagnall <douglas.bagnall@catalyst.net.nz> Reviewed-by: Andrew Bartlett <abartlet@samba.org>
438 lines
14 KiB
Python
438 lines
14 KiB
Python
# Unix SMB/CIFS implementation.
|
|
# Copyright (C) Kai Blin <kai@samba.org> 2011
|
|
# Copyright (C) Ralph Boehme <slow@samba.org> 2016
|
|
#
|
|
# This program is free software; you can redistribute it and/or modify
|
|
# it under the terms of the GNU General Public License as published by
|
|
# the Free Software Foundation; either version 3 of the License, or
|
|
# (at your option) any later version.
|
|
#
|
|
# This program is distributed in the hope that it will be useful,
|
|
# but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
# GNU General Public License for more details.
|
|
#
|
|
# You should have received a copy of the GNU General Public License
|
|
# along with this program. If not, see <http://www.gnu.org/licenses/>.
|
|
#
|
|
|
|
from samba.tests import TestCaseInTempDir
|
|
from samba.dcerpc import dns, dnsp
|
|
from samba import gensec, tests
|
|
from samba import credentials
|
|
import struct
|
|
import samba.ndr as ndr
|
|
import random
|
|
import socket
|
|
import uuid
|
|
import time
|
|
|
|
|
|
class DNSTest(TestCaseInTempDir):
|
|
|
|
def setUp(self):
|
|
super(DNSTest, self).setUp()
|
|
self.timeout = None
|
|
|
|
def errstr(self, errcode):
|
|
"Return a readable error code"
|
|
string_codes = [
|
|
"OK",
|
|
"FORMERR",
|
|
"SERVFAIL",
|
|
"NXDOMAIN",
|
|
"NOTIMP",
|
|
"REFUSED",
|
|
"YXDOMAIN",
|
|
"YXRRSET",
|
|
"NXRRSET",
|
|
"NOTAUTH",
|
|
"NOTZONE",
|
|
"0x0B",
|
|
"0x0C",
|
|
"0x0D",
|
|
"0x0E",
|
|
"0x0F",
|
|
"BADSIG",
|
|
"BADKEY"
|
|
]
|
|
|
|
return string_codes[errcode]
|
|
|
|
def assert_rcode_equals(self, rcode, expected):
|
|
"Helper function to check return code"
|
|
self.assertEqual(rcode, expected, "Expected RCODE %s, got %s" %
|
|
(self.errstr(expected), self.errstr(rcode)))
|
|
|
|
def assert_dns_rcode_equals(self, packet, rcode):
|
|
"Helper function to check return code"
|
|
p_errcode = packet.operation & dns.DNS_RCODE
|
|
self.assertEqual(p_errcode, rcode, "Expected RCODE %s, got %s" %
|
|
(self.errstr(rcode), self.errstr(p_errcode)))
|
|
|
|
def assert_dns_opcode_equals(self, packet, opcode):
|
|
"Helper function to check opcode"
|
|
p_opcode = packet.operation & dns.DNS_OPCODE
|
|
self.assertEqual(p_opcode, opcode, "Expected OPCODE %s, got %s" %
|
|
(opcode, p_opcode))
|
|
|
|
def make_name_packet(self, opcode, qid=None):
|
|
"Helper creating a dns.name_packet"
|
|
p = dns.name_packet()
|
|
if qid is None:
|
|
p.id = random.randint(0x0, 0xff00)
|
|
p.operation = opcode
|
|
p.questions = []
|
|
p.additional = []
|
|
return p
|
|
|
|
def finish_name_packet(self, packet, questions):
|
|
"Helper to finalize a dns.name_packet"
|
|
packet.qdcount = len(questions)
|
|
packet.questions = questions
|
|
|
|
def make_name_question(self, name, qtype, qclass):
|
|
"Helper creating a dns.name_question"
|
|
q = dns.name_question()
|
|
q.name = name
|
|
q.question_type = qtype
|
|
q.question_class = qclass
|
|
return q
|
|
|
|
def make_txt_record(self, records):
|
|
rdata_txt = dns.txt_record()
|
|
s_list = dnsp.string_list()
|
|
s_list.count = len(records)
|
|
s_list.str = records
|
|
rdata_txt.txt = s_list
|
|
return rdata_txt
|
|
|
|
def get_dns_domain(self):
|
|
"Helper to get dns domain"
|
|
return self.creds.get_realm().lower()
|
|
|
|
def dns_transaction_udp(self, packet, host,
|
|
dump=False, timeout=None):
|
|
"send a DNS query and read the reply"
|
|
s = None
|
|
if timeout is None:
|
|
timeout = self.timeout
|
|
try:
|
|
send_packet = ndr.ndr_pack(packet)
|
|
if dump:
|
|
print(self.hexdump(send_packet))
|
|
s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM, 0)
|
|
s.settimeout(timeout)
|
|
s.connect((host, 53))
|
|
s.sendall(send_packet, 0)
|
|
recv_packet = s.recv(2048, 0)
|
|
if dump:
|
|
print(self.hexdump(recv_packet))
|
|
response = ndr.ndr_unpack(dns.name_packet, recv_packet)
|
|
return (response, recv_packet)
|
|
finally:
|
|
if s is not None:
|
|
s.close()
|
|
|
|
def dns_transaction_tcp(self, packet, host,
|
|
dump=False, timeout=None):
|
|
"send a DNS query and read the reply, also return the raw packet"
|
|
s = None
|
|
if timeout is None:
|
|
timeout = self.timeout
|
|
try:
|
|
send_packet = ndr.ndr_pack(packet)
|
|
if dump:
|
|
print(self.hexdump(send_packet))
|
|
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM, 0)
|
|
s.settimeout(timeout)
|
|
s.connect((host, 53))
|
|
tcp_packet = struct.pack('!H', len(send_packet))
|
|
tcp_packet += send_packet
|
|
s.sendall(tcp_packet)
|
|
|
|
recv_packet = s.recv(0xffff + 2, 0)
|
|
if dump:
|
|
print(self.hexdump(recv_packet))
|
|
response = ndr.ndr_unpack(dns.name_packet, recv_packet[2:])
|
|
|
|
finally:
|
|
if s is not None:
|
|
s.close()
|
|
|
|
# unpacking and packing again should produce same bytestream
|
|
my_packet = ndr.ndr_pack(response)
|
|
self.assertEqual(my_packet, recv_packet[2:])
|
|
return (response, recv_packet[2:])
|
|
|
|
def make_txt_update(self, prefix, txt_array, zone=None, ttl=900):
|
|
p = self.make_name_packet(dns.DNS_OPCODE_UPDATE)
|
|
updates = []
|
|
|
|
name = zone or self.get_dns_domain()
|
|
u = self.make_name_question(name, dns.DNS_QTYPE_SOA, dns.DNS_QCLASS_IN)
|
|
updates.append(u)
|
|
self.finish_name_packet(p, updates)
|
|
|
|
updates = []
|
|
r = dns.res_rec()
|
|
r.name = "%s.%s" % (prefix, name)
|
|
r.rr_type = dns.DNS_QTYPE_TXT
|
|
r.rr_class = dns.DNS_QCLASS_IN
|
|
r.ttl = ttl
|
|
r.length = 0xffff
|
|
rdata = self.make_txt_record(txt_array)
|
|
r.rdata = rdata
|
|
updates.append(r)
|
|
p.nscount = len(updates)
|
|
p.nsrecs = updates
|
|
|
|
return p
|
|
|
|
def check_query_txt(self, prefix, txt_array, zone=None):
|
|
name = "%s.%s" % (prefix, zone or self.get_dns_domain())
|
|
p = self.make_name_packet(dns.DNS_OPCODE_QUERY)
|
|
questions = []
|
|
|
|
q = self.make_name_question(name, dns.DNS_QTYPE_TXT, dns.DNS_QCLASS_IN)
|
|
questions.append(q)
|
|
|
|
self.finish_name_packet(p, questions)
|
|
(response, response_packet) =\
|
|
self.dns_transaction_udp(p, host=self.server_ip)
|
|
self.assert_dns_rcode_equals(response, dns.DNS_RCODE_OK)
|
|
self.assertEqual(response.ancount, 1)
|
|
self.assertEqual(response.answers[0].rdata.txt.str, txt_array)
|
|
|
|
|
|
class DNSTKeyTest(DNSTest):
|
|
def setUp(self):
|
|
super(DNSTKeyTest, self).setUp()
|
|
self.settings = {}
|
|
self.settings["lp_ctx"] = self.lp_ctx = tests.env_loadparm()
|
|
self.settings["target_hostname"] = self.server
|
|
|
|
self.creds = credentials.Credentials()
|
|
self.creds.guess(self.lp_ctx)
|
|
self.creds.set_username(tests.env_get_var_value('USERNAME'))
|
|
self.creds.set_password(tests.env_get_var_value('PASSWORD'))
|
|
self.creds.set_kerberos_state(credentials.MUST_USE_KERBEROS)
|
|
self.newrecname = "tkeytsig.%s" % self.get_dns_domain()
|
|
|
|
def tkey_trans(self, creds=None):
|
|
"Do a TKEY transaction and establish a gensec context"
|
|
|
|
if creds is None:
|
|
creds = self.creds
|
|
|
|
self.key_name = "%s.%s" % (uuid.uuid4(), self.get_dns_domain())
|
|
|
|
p = self.make_name_packet(dns.DNS_OPCODE_QUERY)
|
|
q = self.make_name_question(self.key_name,
|
|
dns.DNS_QTYPE_TKEY,
|
|
dns.DNS_QCLASS_IN)
|
|
questions = []
|
|
questions.append(q)
|
|
self.finish_name_packet(p, questions)
|
|
|
|
r = dns.res_rec()
|
|
r.name = self.key_name
|
|
r.rr_type = dns.DNS_QTYPE_TKEY
|
|
r.rr_class = dns.DNS_QCLASS_IN
|
|
r.ttl = 0
|
|
r.length = 0xffff
|
|
rdata = dns.tkey_record()
|
|
rdata.algorithm = "gss-tsig"
|
|
rdata.inception = int(time.time())
|
|
rdata.expiration = int(time.time()) + 60 * 60
|
|
rdata.mode = dns.DNS_TKEY_MODE_GSSAPI
|
|
rdata.error = 0
|
|
rdata.other_size = 0
|
|
|
|
self.g = gensec.Security.start_client(self.settings)
|
|
self.g.set_credentials(creds)
|
|
self.g.set_target_service("dns")
|
|
self.g.set_target_hostname(self.server)
|
|
self.g.want_feature(gensec.FEATURE_SIGN)
|
|
self.g.start_mech_by_name("spnego")
|
|
|
|
finished = False
|
|
client_to_server = b""
|
|
|
|
(finished, server_to_client) = self.g.update(client_to_server)
|
|
self.assertFalse(finished)
|
|
|
|
data = [x if isinstance(x, int) else ord(x) for x in list(server_to_client)]
|
|
rdata.key_data = data
|
|
rdata.key_size = len(data)
|
|
r.rdata = rdata
|
|
|
|
additional = [r]
|
|
p.arcount = 1
|
|
p.additional = additional
|
|
|
|
(response, response_packet) =\
|
|
self.dns_transaction_tcp(p, self.server_ip)
|
|
self.assert_dns_rcode_equals(response, dns.DNS_RCODE_OK)
|
|
|
|
tkey_record = response.answers[0].rdata
|
|
server_to_client = bytes(tkey_record.key_data)
|
|
(finished, client_to_server) = self.g.update(server_to_client)
|
|
self.assertTrue(finished)
|
|
|
|
self.verify_packet(response, response_packet)
|
|
|
|
def verify_packet(self, response, response_packet, request_mac=b""):
|
|
self.assertEqual(response.additional[0].rr_type, dns.DNS_QTYPE_TSIG)
|
|
|
|
tsig_record = response.additional[0].rdata
|
|
mac = bytes(tsig_record.mac)
|
|
|
|
# Cut off tsig record from dns response packet for MAC verification
|
|
# and reset additional record count.
|
|
key_name_len = len(self.key_name) + 2
|
|
tsig_record_len = len(ndr.ndr_pack(tsig_record)) + key_name_len + 10
|
|
|
|
# convert str/bytes to a list (of string char or int)
|
|
# so it can be modified
|
|
response_packet_list = [x if isinstance(x, int) else ord(x) for x in response_packet]
|
|
del response_packet_list[-tsig_record_len:]
|
|
response_packet_list[11] = 0
|
|
|
|
# convert modified list (of string char or int) to str/bytes
|
|
response_packet_wo_tsig = bytes(response_packet_list)
|
|
|
|
fake_tsig = dns.fake_tsig_rec()
|
|
fake_tsig.name = self.key_name
|
|
fake_tsig.rr_class = dns.DNS_QCLASS_ANY
|
|
fake_tsig.ttl = 0
|
|
fake_tsig.time_prefix = tsig_record.time_prefix
|
|
fake_tsig.time = tsig_record.time
|
|
fake_tsig.algorithm_name = tsig_record.algorithm_name
|
|
fake_tsig.fudge = tsig_record.fudge
|
|
fake_tsig.error = 0
|
|
fake_tsig.other_size = 0
|
|
fake_tsig_packet = ndr.ndr_pack(fake_tsig)
|
|
|
|
data = request_mac + response_packet_wo_tsig + fake_tsig_packet
|
|
self.g.check_packet(data, data, mac)
|
|
|
|
def sign_packet(self, packet, key_name):
|
|
"Sign a packet, calculate a MAC and add TSIG record"
|
|
packet_data = ndr.ndr_pack(packet)
|
|
|
|
fake_tsig = dns.fake_tsig_rec()
|
|
fake_tsig.name = key_name
|
|
fake_tsig.rr_class = dns.DNS_QCLASS_ANY
|
|
fake_tsig.ttl = 0
|
|
fake_tsig.time_prefix = 0
|
|
fake_tsig.time = int(time.time())
|
|
fake_tsig.algorithm_name = "gss-tsig"
|
|
fake_tsig.fudge = 300
|
|
fake_tsig.error = 0
|
|
fake_tsig.other_size = 0
|
|
fake_tsig_packet = ndr.ndr_pack(fake_tsig)
|
|
|
|
data = packet_data + fake_tsig_packet
|
|
mac = self.g.sign_packet(data, data)
|
|
mac_list = [x if isinstance(x, int) else ord(x) for x in list(mac)]
|
|
|
|
rdata = dns.tsig_record()
|
|
rdata.algorithm_name = "gss-tsig"
|
|
rdata.time_prefix = 0
|
|
rdata.time = fake_tsig.time
|
|
rdata.fudge = 300
|
|
rdata.original_id = packet.id
|
|
rdata.error = 0
|
|
rdata.other_size = 0
|
|
rdata.mac = mac_list
|
|
rdata.mac_size = len(mac_list)
|
|
|
|
r = dns.res_rec()
|
|
r.name = key_name
|
|
r.rr_type = dns.DNS_QTYPE_TSIG
|
|
r.rr_class = dns.DNS_QCLASS_ANY
|
|
r.ttl = 0
|
|
r.length = 0xffff
|
|
r.rdata = rdata
|
|
|
|
additional = [r]
|
|
packet.additional = additional
|
|
packet.arcount = 1
|
|
|
|
return mac
|
|
|
|
def bad_sign_packet(self, packet, key_name):
|
|
'''Add bad signature for a packet by bitflipping
|
|
the final byte in the MAC'''
|
|
|
|
mac_list = [x if isinstance(x, int) else ord(x) for x in list("badmac")]
|
|
|
|
rdata = dns.tsig_record()
|
|
rdata.algorithm_name = "gss-tsig"
|
|
rdata.time_prefix = 0
|
|
rdata.time = int(time.time())
|
|
rdata.fudge = 300
|
|
rdata.original_id = packet.id
|
|
rdata.error = 0
|
|
rdata.other_size = 0
|
|
rdata.mac = mac_list
|
|
rdata.mac_size = len(mac_list)
|
|
|
|
r = dns.res_rec()
|
|
r.name = key_name
|
|
r.rr_type = dns.DNS_QTYPE_TSIG
|
|
r.rr_class = dns.DNS_QCLASS_ANY
|
|
r.ttl = 0
|
|
r.length = 0xffff
|
|
r.rdata = rdata
|
|
|
|
additional = [r]
|
|
packet.additional = additional
|
|
packet.arcount = 1
|
|
|
|
def search_record(self, name):
|
|
p = self.make_name_packet(dns.DNS_OPCODE_QUERY)
|
|
questions = []
|
|
|
|
q = self.make_name_question(name, dns.DNS_QTYPE_TXT, dns.DNS_QCLASS_IN)
|
|
questions.append(q)
|
|
|
|
self.finish_name_packet(p, questions)
|
|
(response, response_packet) =\
|
|
self.dns_transaction_udp(p, self.server_ip)
|
|
return response.operation & 0x000F
|
|
|
|
def make_update_request(self, delete=False):
|
|
"Create a DNS update request"
|
|
|
|
rr_class = dns.DNS_QCLASS_IN
|
|
ttl = 900
|
|
|
|
if delete:
|
|
rr_class = dns.DNS_QCLASS_NONE
|
|
ttl = 0
|
|
|
|
p = self.make_name_packet(dns.DNS_OPCODE_UPDATE)
|
|
q = self.make_name_question(self.get_dns_domain(),
|
|
dns.DNS_QTYPE_SOA,
|
|
dns.DNS_QCLASS_IN)
|
|
questions = []
|
|
questions.append(q)
|
|
self.finish_name_packet(p, questions)
|
|
|
|
updates = []
|
|
r = dns.res_rec()
|
|
r.name = self.newrecname
|
|
r.rr_type = dns.DNS_QTYPE_TXT
|
|
r.rr_class = rr_class
|
|
r.ttl = ttl
|
|
r.length = 0xffff
|
|
rdata = self.make_txt_record(['"This is a test"'])
|
|
r.rdata = rdata
|
|
updates.append(r)
|
|
p.nscount = len(updates)
|
|
p.nsrecs = updates
|
|
|
|
return p
|