CVE-2018-1140 dns: Add a test to trigger the LDB casefolding issue on invalid chars

BUG: https://bugzilla.samba.org/show_bug.cgi?id=13466

Signed-off-by: Kai Blin <kai@samba.org>
Reviewed-by: Douglas Bagnall <douglas.bagnall@catalyst.net.nz>

1 files changed, 87 insertions, 0 deletions

diff --git a/python/samba/tests/dns_invalid.py b/python/samba/tests/dns_invalid.py
new file mode 100644
index 00000000000..9f87cd56084
--- /dev/null
+++ b/python/samba/tests/dns_invalid.py
@@ -0,0 +1,87 @@
+# Unix SMB/CIFS implementation.
+# Copyright (C) Kai Blin  <kai@samba.org> 2018
+#
+# 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/>.
+#
+
+import os
+import sys
+import struct
+import random
+import socket
+import samba.ndr as ndr
+from samba import credentials, param
+from samba.dcerpc import dns, dnsp, dnsserver
+from samba.netcmd.dns import TXTRecord, dns_record_match, data_to_dns_record
+from samba.tests.subunitrun import SubunitOptions, TestProgram
+from samba import werror, WERRORError
+from samba.tests.dns_base import DNSTest
+import samba.getopt as options
+import optparse
+
+parser = optparse.OptionParser("dns_invalid.py <server ip> [options]")
+sambaopts = options.SambaOptions(parser)
+parser.add_option_group(sambaopts)
+
+# This timeout only has relevance when testing against Windows
+# Format errors tend to return patchy responses, so a timeout is needed.
+parser.add_option("--timeout", type="int", dest="timeout",
+                  help="Specify timeout for DNS requests")
+
+# use command line creds if available
+credopts = options.CredentialsOptions(parser)
+parser.add_option_group(credopts)
+subunitopts = SubunitOptions(parser)
+parser.add_option_group(subunitopts)
+
+opts, args = parser.parse_args()
+
+lp = sambaopts.get_loadparm()
+creds = credopts.get_credentials(lp)
+
+timeout = opts.timeout
+
+if len(args) < 1:
+    parser.print_usage()
+    sys.exit(1)
+
+server_ip = args[0]
+creds.set_krb_forwardable(credentials.NO_KRB_FORWARDABLE)
+
+
+class TestBrokenQueries(DNSTest):
+    def setUp(self):
+        super(TestBrokenQueries, self).setUp()
+        global server, server_ip, lp, creds, timeout
+        self.server_ip = server_ip
+        self.lp = lp
+        self.creds = creds
+        self.timeout = timeout
+
+    def test_invalid_chars_in_name(self):
+        """Check the server refuses invalid characters in the query name"""
+        p = self.make_name_packet(dns.DNS_OPCODE_QUERY)
+        questions = []
+
+        name = "\x10\x11\x05\xa8.%s" % self.get_dns_domain()
+        q = self.make_name_question(name, dns.DNS_QTYPE_A, dns.DNS_QCLASS_IN)
+        print "asking for ", q.name
+        questions.append(q)
+
+        self.finish_name_packet(p, questions)
+        (response, response_packet) = self.dns_transaction_udp(p, host=server_ip)
+        self.assert_dns_rcode_equals(response, dns.DNS_RCODE_NXDOMAIN)
+
+
+TestProgram(module=__name__, opts=subunitopts)