Filter token data out of catch_errors middleware

If an exception is caught by the catch_errors middleware the entire
request is dumped into the log including sensitive information like
tokens. Filter that information before outputting the failed request.

Closes-Bug: #1628031
Change-Id: I2563403993513c37751576223275350cac2e0937

oslo_middleware/catch_errors.py

@@ -14,6 +14,7 @@
 #    under the License.
 
 import logging
+import re
 
 import webob.dec
 import webob.exc
@@ -24,6 +25,8 @@ from oslo_middleware import base
 
 LOG = logging.getLogger(__name__)
 
+_TOKEN_RE = re.compile('^(X-\w+-Token):.*$', flags=re.MULTILINE)
+
 
 class CatchErrors(base.ConfigurableMiddleware):
     """Middleware that provides high-level error handling.
@@ -37,7 +40,8 @@ class CatchErrors(base.ConfigurableMiddleware):
         try:
             response = req.get_response(self.application)
         except Exception:
+            req_str = _TOKEN_RE.sub(r'\1: <removed>', req.as_text())
             LOG.exception(_LE('An error occurred during '
-                              'processing the request: %s'), req)
+                              'processing the request: %s'), req_str)
             response = webob.exc.HTTPInternalServerError()
         return response

oslo_middleware/tests/test_catch_errors.py

@@ -13,6 +13,7 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+import fixtures
 import mock
 from oslotest import base as test_base
 import webob.dec
@@ -45,3 +46,27 @@ class CatchErrorsTest(test_base.BaseTestCase):
             self._test_has_request_id(application,
                                       webob.exc.HTTPInternalServerError.code)
             self.assertEqual(1, log_exc.call_count)
+
+    def test_filter_tokens_from_log(self):
+        logger = self.useFixture(fixtures.FakeLogger(nuke_handlers=False))
+
+        @webob.dec.wsgify
+        def application(req):
+            raise Exception()
+
+        app = catch_errors.CatchErrors(application)
+        req = webob.Request.blank('/test',
+                                  text=u'test data',
+                                  method='POST',
+                                  headers={'X-Auth-Token': 'secret1',
+                                           'X-Service-Token': 'secret2',
+                                           'X-Other-Token': 'secret3'})
+        res = req.get_response(app)
+        self.assertEqual(500, res.status_int)
+
+        output = logger.output
+
+        self.assertIn('X-Auth-Token: <removed>', output)
+        self.assertIn('X-Service-Token: <removed>', output)
+        self.assertIn('X-Other-Token: <removed>', output)
+        self.assertIn('test data', output)