test_credential.py work with python34

test_credential.py was failing on python34 with two different errors.

1. Should encode unicode into byte before hashing on python3

...
    hash_.update(access)
TypeError: Unicode-objects must be encoded before hashing

2. Request body should be always bytes on python3, use `dump_as_bytes`
to covert the body to bytes.

...
  File "/opt/stack/keystone/.tox/py34/lib/python3.4/site-packages/
  webob/request.py",
  line 710, in _body__set % type(value))
TypeError: You can only set Request.body to bytes (not <class 'str'>)

bp python3
Change-Id: I82e731ea5e517e030db55cf01cc86db9684f4622

keystone/common/utils.py

@@ -135,6 +135,8 @@ def verify_length_and_trunc_password(password):
 
 def hash_access_key(access):
     hash_ = hashlib.sha256()
+    if not isinstance(access, six.binary_type):
+        access = access.encode('utf-8')
     hash_.update(access)
     return hash_.hexdigest()
 

keystone/tests/unit/rest.py

@@ -152,7 +152,11 @@ class RestfulTestCase(unit.TestCase):
             headers['Accept'] = 'application/json'
             if body:
                 headers['Content-Type'] = 'application/json'
-                return jsonutils.dumps(body)
+                # NOTE(davechen):dump the body to bytes since WSGI requires
+                # the body of the response to be `Bytestrings`.
+                # see pep-3333:
+                # https://www.python.org/dev/peps/pep-3333/#a-note-on-string-types
+                return jsonutils.dump_as_bytes(body)
 
     def _from_content_type(self, response, content_type=None):
         """Attempt to decode JSON and XML automatically, if detected."""

tox.ini

@@ -43,6 +43,7 @@ commands =
       keystone/tests/unit/test_cli.py \
       keystone/tests/unit/test_config.py \
       keystone/tests/unit/test_contrib_s3_core.py \
+      keystone/tests/unit/test_credential.py \
       keystone/tests/unit/test_driver_hints.py \
       keystone/tests/unit/test_exception.py \
       keystone/tests/unit/test_ipv6.py \