python: Add RPC credentials cache test

Test that we can use a credentials cache with a user's service ticket
obtained with our Python code to connect to a service through RPC.

Signed-off-by: Joseph Sutton <josephsutton@catalyst.net.nz>
Reviewed-by: Andrew Bartlett <abartlet@samba.org>
Reviewed-by: Douglas Bagnall <douglas.bagnall@catalyst.net.nz>

python/samba/tests/krb5/test_rpc.py

@@ -0,0 +1,77 @@
+#!/usr/bin/env python3
+# Unix SMB/CIFS implementation.
+# Copyright (C) Stefan Metzmacher 2020
+# Copyright (C) 2021 Catalyst.Net Ltd
+#
+# 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 sys
+import os
+
+from samba.dcerpc import lsa
+
+from samba.tests.krb5.kdc_base_test import KDCBaseTest
+
+sys.path.insert(0, "bin/python")
+os.environ["PYTHONUNBUFFERED"] = "1"
+
+global_asn1_print = False
+global_hexdump = False
+
+
+class RpcTests(KDCBaseTest):
+    """Test for RPC authentication using Kerberos credentials stored in a
+       credentials cache file.
+    """
+
+    def test_rpc(self):
+        # Create a user account and a machine account, along with a Kerberos
+        # credentials cache file where the service ticket authenticating the
+        # user are stored.
+
+        user_name = "rpcusr"
+        mach_name = self.dns_host_name
+        service = "cifs"
+
+        # Create the user account.
+        (user_credentials, _) = self.create_account(user_name)
+
+        # Talk to the KDC to obtain the service ticket, which gets placed into
+        # the cache. The machine account name has to match the name in the
+        # ticket, to ensure that the krbtgt ticket doesn't also need to be
+        # stored.
+        (creds, cachefile) = self.create_ccache_with_user(user_credentials,
+                                                          mach_name,
+                                                          service)
+
+        # Authenticate in-process to the machine account using the user's
+        # cached credentials.
+
+        binding_str = "ncacn_np:%s[\\pipe\\lsarpc]" % mach_name
+        conn = lsa.lsarpc(binding_str, self.lp, creds)
+
+        (account_name, _) = conn.GetUserName(None, None, None)
+
+        self.assertEqual(user_name, account_name.string)
+
+        # Remove the cached credentials file.
+        os.remove(cachefile.name)
+
+
+if __name__ == "__main__":
+    global_asn1_print = True
+    global_hexdump = True
+    import unittest
+    unittest.main()

python/samba/tests/usage.py

@@ -98,6 +98,7 @@ EXCLUDE_USAGE = {
     'python/samba/tests/krb5/kdc_tgs_tests.py',
     'python/samba/tests/krb5/test_ccache.py',
     'python/samba/tests/krb5/test_ldap.py',
+    'python/samba/tests/krb5/test_rpc.py',
     'python/samba/tests/krb5/ms_kile_client_principal_lookup_tests.py',
 }
 

source4/selftest/tests.py

@@ -837,6 +837,7 @@ planoldpythontestsuite("fl2008r2dc:local", "samba.tests.krb5.xrealm_tests")
 
 planoldpythontestsuite("ad_dc_default", "samba.tests.krb5.test_ccache")
 planoldpythontestsuite("ad_dc_default", "samba.tests.krb5.test_ldap")
+planoldpythontestsuite("ad_dc_default", "samba.tests.krb5.test_rpc")
 
 for env in ["ad_dc", smbv1_disabled_testenv]:
     planoldpythontestsuite(env, "samba.tests.smb", extra_args=['-U"$USERNAME%$PASSWORD"'])