Add console allowed origins setting

Adds a DEFAULT/console_allowed_origins to the console
websocket proxy to allow connections from other Origin hostnames
(other than only the hostname in the Host header.)

Origin header checking was introduced in
https://review.openstack.org/#/c/163033/ as a fix for bug 1409142
and CVE-2015-0259.  However there are valid use cases where you
want to do cross-site web socket connections.

This patch allows for controlled cross-site web socket connections
to the console proxy services.

DocImpact

Change-Id: If7995bb7afc255f5ad834dc8a7044ef38b6cb335
Closes-bug: 1474079

nova/console/websocketproxy.py

@@ -30,9 +30,19 @@ from nova.consoleauth import rpcapi as consoleauth_rpcapi
 from nova import context
 from nova import exception
 from nova.i18n import _
+from oslo_config import cfg
 
 LOG = logging.getLogger(__name__)
 
+CONF = cfg.CONF
+console_origin_opts = [
+    cfg.ListOpt('console_allowed_origins',
+                default=[],
+                help='Allowed Origin header hostnames for access to console '
+                     'proxy servers'),
+]
+CONF.register_opts(console_origin_opts)
+
 
 class NovaProxyRequestHandlerBase(object):
     def address_string(self):
@@ -104,6 +114,8 @@ class NovaProxyRequestHandlerBase(object):
                 expected_origin_hostname = e.split(']')[0][1:]
             else:
                 expected_origin_hostname = e.split(':')[0]
+        expected_origin_hostnames = CONF.console_allowed_origins
+        expected_origin_hostnames.append(expected_origin_hostname)
         origin_url = self.headers.getheader('Origin')
         # missing origin header indicates non-browser client which is OK
         if origin_url is not None:
@@ -113,7 +125,7 @@ class NovaProxyRequestHandlerBase(object):
             if origin_hostname == '' or origin_scheme == '':
                 detail = _("Origin header not valid.")
                 raise exception.ValidationError(detail=detail)
-            if expected_origin_hostname != origin_hostname:
+            if origin_hostname not in expected_origin_hostnames:
                 detail = _("Origin header does not match this host.")
                 raise exception.ValidationError(detail=detail)
             if not self.verify_origin_proto(connect_info, origin_scheme):

nova/tests/unit/console/test_websocketproxy.py

@@ -30,6 +30,8 @@ class NovaProxyRequestHandlerBaseTestCase(test.NoDBTestCase):
     def setUp(self):
         super(NovaProxyRequestHandlerBaseTestCase, self).setUp()
 
+        self.flags(console_allowed_origins = ['allowed-origin-example-1.net',
+                                              'allowed-origin-example-2.net'])
         self.wh = websocketproxy.NovaProxyRequestHandlerBase()
         self.wh.socket = mock.MagicMock()
         self.wh.msg = mock.MagicMock()
@@ -76,6 +78,16 @@ class NovaProxyRequestHandlerBaseTestCase(test.NoDBTestCase):
         else:
             return
 
+    def _fake_getheader_allowed_origin(self, header):
+        if header == 'cookie':
+            return 'token="123-456-789"'
+        elif header == 'Origin':
+            return 'https://allowed-origin-example-2.net:6080'
+        elif header == 'Host':
+            return 'example.net:6080'
+        else:
+            return
+
     def _fake_getheader_blank_origin(self, header):
         if header == 'cookie':
             return 'token="123-456-789"'
@@ -266,6 +278,25 @@ class NovaProxyRequestHandlerBaseTestCase(test.NoDBTestCase):
         self.assertRaises(exception.ValidationError,
                           self.wh.new_websocket_client)
 
+    @mock.patch('nova.consoleauth.rpcapi.ConsoleAuthAPI.check_token')
+    def test_new_websocket_client_novnc_allowed_origin_header(self,
+                                                              check_token):
+        check_token.return_value = {
+            'host': 'node1',
+            'port': '10000',
+            'console_type': 'novnc',
+            'access_url': 'https://example.net:6080'
+        }
+        self.wh.socket.return_value = '<socket>'
+        self.wh.path = "http://127.0.0.1/"
+        self.wh.headers.getheader = self._fake_getheader_allowed_origin
+
+        self.wh.new_websocket_client()
+
+        check_token.assert_called_with(mock.ANY, token="123-456-789")
+        self.wh.socket.assert_called_with('node1', 10000, connect=True)
+        self.wh.do_proxy.assert_called_with('<socket>')
+
     @mock.patch('nova.consoleauth.rpcapi.ConsoleAuthAPI.check_token')
     def test_new_websocket_client_novnc_blank_origin_header(self, check_token):
         check_token.return_value = {