/usr/lib/python2.7/dist-packages/keystone/credential/ is in python-keystone 2:13.0.0-0ubuntu1.
This file is owned by root:root, with mode 0o755.
..
/usr/lib/python2.7/dist-packages/keystone/credential/__init__.py
/usr/lib/python2.7/dist-packages/keystone/credential/backends/
/usr/lib/python2.7/dist-packages/keystone/credential/backends/__init__.py
/usr/lib/python2.7/dist-packages/keystone/credential/backends/base.py
/usr/lib/python2.7/dist-packages/keystone/credential/backends/sql.py
/usr/lib/python2.7/dist-packages/keystone/credential/controllers.py
/usr/lib/python2.7/dist-packages/keystone/credential/core.py
/usr/lib/python2.7/dist-packages/keystone/credential/provider.py
/usr/lib/python2.7/dist-packages/keystone/credential/providers/
/usr/lib/python2.7/dist-packages/keystone/credential/providers/__init__.py
/usr/lib/python2.7/dist-packages/keystone/credential/providers/core.py
/usr/lib/python2.7/dist-packages/keystone/credential/providers/fernet/
/usr/lib/python2.7/dist-packages/keystone/credential/providers/fernet/__init__.py
/usr/lib/python2.7/dist-packages/keystone/credential/providers/fernet/core.py
/usr/lib/python2.7/dist-packages/keystone/credential/routers.py
/usr/lib/python2.7/dist-packages/keystone/credential/schema.py