Move fernet utils into keystone/common/

If we are going to be using fernet utilities to implement encryption of
credentials at rest, we should put the utilities in a more available
place.

bp credential-encryption

Change-Id: I06aff77836527885b3df1cbd25834906cda73910

keystone/cmd/cli.py

@@ -524,7 +524,7 @@ class FernetSetup(BasePermissionsSetup):
 
     @classmethod
     def main(cls):
-        from keystone.token.providers.fernet import utils as fernet
+        from keystone.common import fernet_utils as fernet
 
         keystone_user_id, keystone_group_id = cls.get_user_group()
         fernet.create_key_directory(keystone_user_id, keystone_group_id)
@@ -555,7 +555,7 @@ class FernetRotate(BasePermissionsSetup):
 
     @classmethod
     def main(cls):
-        from keystone.token.providers.fernet import utils as fernet
+        from keystone.common import fernet_utils as fernet
 
         keystone_user_id, keystone_group_id = cls.get_user_group()
         if fernet.validate_key_repository(requires_write=True):

keystone/cmd/doctor/tokens_fernet.py

@@ -12,7 +12,7 @@
 
 import keystone.conf
 
-from keystone.token.providers.fernet import utils as fernet_utils
+from keystone.common import fernet_utils
 
 
 CONF = keystone.conf.CONF

keystone/tests/unit/ksfixtures/key_repository.py

@@ -12,7 +12,7 @@
 
 import fixtures
 
-from keystone.token.providers.fernet import utils
+from keystone.common import fernet_utils as utils
 
 
 class KeyRepository(fixtures.Fixture):

keystone/tests/unit/token/test_fernet_provider.py

@@ -20,6 +20,7 @@ import msgpack
 from oslo_utils import timeutils
 from six.moves import urllib
 
+from keystone.common import fernet_utils
 from keystone.common import utils
 import keystone.conf
 from keystone import exception
@@ -30,7 +31,6 @@ from keystone.tests.unit.ksfixtures import database
 from keystone.token import provider
 from keystone.token.providers import fernet
 from keystone.token.providers.fernet import token_formatters
-from keystone.token.providers.fernet import utils as fernet_utils
 
 
 CONF = keystone.conf.CONF

keystone/token/providers/fernet/token_formatters.py

@@ -24,12 +24,12 @@ from six.moves import map
 from six.moves import urllib
 
 from keystone.auth import plugins as auth_plugins
+from keystone.common import fernet_utils as utils
 from keystone.common import utils as ks_utils
 import keystone.conf
 from keystone import exception
 from keystone.i18n import _, _LI
 from keystone.token import provider
-from keystone.token.providers.fernet import utils
 
 
 CONF = keystone.conf.CONF