CVE-2020-10700: dsdb: Add test for ASQ and ASQ in combination with paged_results

Thanks to Andrei Popa <andrei.popa@next-gen.ro> for finding,
reporting and working with us to diagnose this issue!

BUG: https://bugzilla.samba.org/show_bug.cgi?id=14331

Signed-off-by: Andrew Bartlett <abartlet@samba.org>
Reviewed-by: Gary Lockyer <gary@catalyst.net.nz>

3 files changed, 173 insertions, 0 deletions

diff --git a/selftest/knownfail.d/asq b/selftest/knownfail.d/asq
new file mode 100644
index 00000000000..eb0e3e0aba1
--- /dev/null
+++ b/selftest/knownfail.d/asq
@@ -0,0 +1 @@
+samba4.asq.python\(ad_dc_default\).__main__.ASQLDAPTest.test_asq_paged
\ No newline at end of file
diff --git a/source4/dsdb/tests/python/asq.py b/source4/dsdb/tests/python/asq.py
new file mode 100644
index 00000000000..a32c9f40cd3
--- /dev/null
+++ b/source4/dsdb/tests/python/asq.py
@@ -0,0 +1,171 @@
+#!/usr/bin/env python3
+#
+# Test ASQ LDAP control behaviour in Samba
+# Copyright (C) Andrew Bartlett 2019-2020
+#
+# Based on Unit tests for the notification control
+# Copyright (C) Stefan Metzmacher 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/>.
+
+import optparse
+import sys
+import os
+import random
+
+sys.path.insert(0, "bin/python")
+import samba
+from samba.tests.subunitrun import SubunitOptions, TestProgram
+
+import samba.getopt as options
+
+from samba.auth import system_session
+from samba import ldb
+from samba.samdb import SamDB
+from samba.ndr import ndr_unpack
+from samba import gensec
+from samba.credentials import Credentials
+import samba.tests
+
+from ldb import SCOPE_SUBTREE, SCOPE_ONELEVEL, SCOPE_BASE, LdbError
+from ldb import ERR_TIME_LIMIT_EXCEEDED, ERR_ADMIN_LIMIT_EXCEEDED, ERR_UNWILLING_TO_PERFORM
+from ldb import Message
+
+parser = optparse.OptionParser("large_ldap.py [options] <host>")
+sambaopts = options.SambaOptions(parser)
+parser.add_option_group(sambaopts)
+parser.add_option_group(options.VersionOptions(parser))
+# 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()
+
+if len(args) < 1:
+    parser.print_usage()
+    sys.exit(1)
+
+url = args[0]
+
+lp = sambaopts.get_loadparm()
+creds = credopts.get_credentials(lp)
+
+
+class ASQLDAPTest(samba.tests.TestCase):
+
+    def setUp(self):
+        super(ASQLDAPTest, self).setUp()
+        self.ldb = samba.Ldb(url, credentials=creds, session_info=system_session(lp), lp=lp)
+        self.base_dn = self.ldb.get_default_basedn()
+        self.NAME_ASQ="asq_" + format(random.randint(0, 99999), "05")
+        self.OU_NAME_ASQ= self.NAME_ASQ + "_ou"
+        self.ou_dn = ldb.Dn(self.ldb, "ou=" + self.OU_NAME_ASQ + "," + str(self.base_dn))
+
+        samba.tests.delete_force(self.ldb, self.ou_dn,
+                                 controls=['tree_delete:1'])
+
+        self.ldb.add({
+            "dn": self.ou_dn,
+            "objectclass": "organizationalUnit",
+            "ou": self.OU_NAME_ASQ})
+
+        self.members = []
+        self.members2 = []
+
+        for x in range(20):
+            name = self.NAME_ASQ + "_" + str(x)
+            dn = ldb.Dn(self.ldb,
+                        "cn=" + name + "," + str(self.ou_dn))
+            self.members.append(dn)
+            self.ldb.add({
+                "dn": dn,
+                "objectclass": "group"})
+
+        for x in range(20):
+            name = self.NAME_ASQ + "_" + str(x + 20)
+            dn = ldb.Dn(self.ldb,
+                        "cn=" + name + "," + str(self.ou_dn))
+            self.members2.append(dn)
+            self.ldb.add({
+                "dn": dn,
+                "objectclass": "group",
+                "member": [str(x) for x in self.members]})
+
+        name = self.NAME_ASQ + "_" + str(x + 40)
+        self.top_dn = ldb.Dn(self.ldb,
+                             "cn=" + name + "," + str(self.ou_dn))
+        self.ldb.add({
+            "dn": self.top_dn,
+            "objectclass": "group",
+            "member": [str(x) for x in self.members2]})
+
+    def tearDown(self):
+        samba.tests.delete_force(self.ldb, self.ou_dn,
+                                 controls=['tree_delete:1'])
+
+    def test_asq(self):
+        """Testing ASQ behaviour.
+
+        ASQ is very strange, it turns a BASE search into a search for
+        all the objects pointed to by the specified attribute,
+        returning multiple entries!
+
+        """
+
+        msgs = self.ldb.search(base=self.top_dn,
+                               scope=ldb.SCOPE_BASE,
+                               attrs=["objectGUID", "cn", "member"],
+                               controls=["asq:1:member"])
+
+        self.assertEqual(len(msgs), 20)
+
+        for msg in msgs:
+            self.assertNotEqual(msg.dn, self.top_dn)
+            self.assertIn(msg.dn, self.members2)
+            for group in msg["member"]:
+                self.assertIn(ldb.Dn(self.ldb, str(group)),
+                              self.members)
+
+    def test_asq_paged(self):
+        """Testing ASQ behaviour with paged_results set.
+
+        ASQ is very strange, it turns a BASE search into a search for
+        all the objects pointed to by the specified attribute,
+        returning multiple entries!
+
+        """
+
+        msgs = self.ldb.search(base=self.top_dn,
+                               scope=ldb.SCOPE_BASE,
+                               attrs=["objectGUID", "cn", "member"],
+                               controls=["asq:1:member",
+                                         "paged_results:1:1024"])
+
+        self.assertEqual(len(msgs), 20)
+
+        for msg in msgs:
+            self.assertNotEqual(msg.dn, self.top_dn)
+            self.assertIn(msg.dn, self.members2)
+            for group in msg["member"]:
+                self.assertIn(ldb.Dn(self.ldb, str(group)),
+                              self.members)
+
+if "://" not in url:
+    if os.path.isfile(url):
+        url = "tdb://%s" % url
+    else:
+        url = "ldap://%s" % url
+
+TestProgram(module=__name__, opts=subunitopts)
diff --git a/source4/selftest/tests.py b/source4/selftest/tests.py
index ae2b10ae659..52db18a872b 100755
--- a/source4/selftest/tests.py
+++ b/source4/selftest/tests.py
@@ -885,6 +885,7 @@ plantestsuite_loadlist("samba4.tokengroups.krb5.python(ad_dc_default)", "ad_dc_d
 plantestsuite_loadlist("samba4.tokengroups.ntlm.python(ad_dc_default)", "ad_dc_default:local", [python, os.path.join(DSDB_PYTEST_DIR, "token_group.py"), '$SERVER', '-U"$USERNAME%$PASSWORD"', '--workgroup=$DOMAIN', '-k', 'no', '$LOADLIST', '$LISTOPT'])
 plantestsuite("samba4.sam.python(fl2008r2dc)", "fl2008r2dc", [python, os.path.join(DSDB_PYTEST_DIR, "sam.py"), '$SERVER', '-U"$USERNAME%$PASSWORD"', '--workgroup=$DOMAIN'])
 plantestsuite("samba4.sam.python(ad_dc_default)", "ad_dc_default", [python, os.path.join(DSDB_PYTEST_DIR, "sam.py"), '$SERVER', '-U"$USERNAME%$PASSWORD"', '--workgroup=$DOMAIN'])
+plantestsuite("samba4.asq.python(ad_dc_default)", "ad_dc_default", [python, os.path.join(DSDB_PYTEST_DIR, "asq.py"), '$SERVER', '-U"$USERNAME%$PASSWORD"', '--workgroup=$DOMAIN'])
 plantestsuite("samba4.user_account_control.python(ad_dc_default)", "ad_dc_default", [python, os.path.join(DSDB_PYTEST_DIR, "user_account_control.py"), '$SERVER', '-U"$USERNAME%$PASSWORD"', '--workgroup=$DOMAIN'])
 
 for env in ['ad_dc_default:local', 'schema_dc:local']: