From 340017f7303cd82ef15f7a3813f6b0c9e72ad81b Mon Sep 17 00:00:00 2001
From: David Stanek <dstanek@dstanek.com>
Date: Fri, 15 Aug 2014 14:59:48 +0000
Subject: [PATCH] Adds a whitelist for endpoint catalog substitution

Change-Id: If02327d70d0143d805969fe927898f08eb84c4c2
Closes-Bug: #1354208
---
 keystone/catalog/core.py                 |  4 ++++
 keystone/common/config.py                | 10 ++++++++++
 keystone/common/utils.py                 | 12 ++++++++++++
 keystone/tests/unit/catalog/test_core.py | 21 +++++++++++++++++++++
 4 files changed, 47 insertions(+)

diff --git a/keystone/catalog/core.py b/keystone/catalog/core.py
index fd0ebd1..67a3567 100644
--- a/keystone/catalog/core.py
+++ b/keystone/catalog/core.py
@@ -23,6 +23,7 @@ from keystone.common import cache
 from keystone.common import dependency
 from keystone.common import driver_hints
 from keystone.common import manager
+from keystone.common import utils
 from keystone import config
 from keystone import exception
 from keystone.i18n import _
@@ -45,6 +46,9 @@ def format_url(url, substitutions):
     :returns: a formatted URL
 
     """
+    substitutions = utils.WhiteListedFormatter(
+        CONF.catalog.endpoint_substitution_whitelist,
+        substitutions)
     try:
         result = url.replace('$(', '%(') % substitutions
     except AttributeError:
diff --git a/keystone/common/config.py b/keystone/common/config.py
index f694c51..883cb08 100644
--- a/keystone/common/config.py
+++ b/keystone/common/config.py
@@ -775,6 +775,16 @@ FILE_OPTIONS = {
         cfg.IntOpt('list_limit',
                    help='Maximum number of entities that will be returned '
                         'in a catalog collection.'),
+        cfg.ListOpt('endpoint_substitution_whitelist',
+                    default=['tenant_id', 'user_id', 'public_bind_host',
+                             'admin_bind_host', 'compute_host', 'compute_port',
+                             'admin_port', 'public_port', 'public_endpoint',
+                             'admin_endpoint'],
+                    help='List of possible substitutions for use in '
+                         'formatting endpoints. Use caution when modifying '
+                         'this list. It will give users with permission to '
+                         'create endpoints the ability to see those values '
+                         'in your configuration file.'),
     ],
     'kvs': [
         cfg.ListOpt('backends', default=[],
diff --git a/keystone/common/utils.py b/keystone/common/utils.py
index 4fe97c8..6834d97 100644
--- a/keystone/common/utils.py
+++ b/keystone/common/utils.py
@@ -526,3 +526,15 @@ def make_dirs(path, mode=None, user=None, group=None, log=None):
             raise EnvironmentError("makedirs('%s'): %s" % (path, exc.strerror))
 
     set_permissions(path, mode, user, group, log)
+
+
+class WhiteListedFormatter(object):
+
+    def __init__(self, whitelist, data):
+        self._whitelist = set(whitelist or [])
+        self._data = data
+
+    def __getitem__(self, name):
+        if name not in self._whitelist:
+            raise KeyError
+        return self._data[name]
diff --git a/keystone/tests/unit/catalog/test_core.py b/keystone/tests/unit/catalog/test_core.py
index 7b142ed..684e1dc 100644
--- a/keystone/tests/unit/catalog/test_core.py
+++ b/keystone/tests/unit/catalog/test_core.py
@@ -10,14 +10,26 @@
 # License for the specific language governing permissions and limitations
 # under the License.
 
+from oslo.config import fixture as config_fixture
 import testtools
 
 from keystone.catalog import core
+from keystone import config
 from keystone import exception
 
 
+CONF = config.CONF
+
+
 class FormatUrlTests(testtools.TestCase):
 
+    def setUp(self):
+        super(FormatUrlTests, self).setUp()
+        fixture = self.useFixture(config_fixture.Config(CONF))
+        fixture.config(
+            group='catalog',
+            endpoint_substitution_whitelist=['host', 'port', 'part1', 'part2'])
+
     def test_successful_formatting(self):
         url_template = 'http://%(host)s:%(port)d/%(part1)s/%(part2)s'
         values = {'host': 'server', 'port': 9090, 'part1': 'A', 'part2': 'B'}
@@ -53,3 +65,12 @@ class FormatUrlTests(testtools.TestCase):
 
         _test(None)
         _test(object())
+
+    def test_substitution_with_key_not_whitelisted(self):
+        url_template = 'http://%(host)s:%(port)d/%(part1)s/%(part2)s/%(part3)s'
+        values = {'host': 'server', 'port': 9090,
+                  'part1': 'A', 'part2': 'B', 'part3': 'C'}
+        self.assertRaises(exception.MalformedEndpoint,
+                          core.format_url,
+                          url_template,
+                          values)
-- 
2.0.4