Protecting Plaintext Secrets

bp protecting plaintext password

Problem description

Current OpenStack services require plaintext passwords and credentials for various access, e.g. database, keystoneauth, etc.

Even with proper file permissions set on these files, often time during troubleshooting sessions, these configuration files are sent via emails without the passwords properly redacted.

Also, the ability to change passwords across multiple nodes are heavily relying on the deployment tools of choice (ansible, fuel, etc.)

Proposed change

First of all, in order to properly secure the secrets in those configuration files, we should implement an oslo.config driver as described in the oslo spec

Phase 0:

Using HTTP and HTTPS urls as a reference to secrets:

As a basic but useful solution, we proposed using an external URL pointing to an HTTP or HTTPS url to access those secrets.

Note: This Phase 0 was merged on oslo.config in the Rocky release.

Phase 1:

Currently, on OpenStack, we have a Generic Key Manager interface called Castellan, which means that Castellan works on the principle of providing an abstracted key manager based on your configuration. In this manner, several different management services can be supported through a single interface. To integrate Castellan with oslo.config will have a Castellan implementation to oslo.config driver defined before.

After that, we will be able to use a Castellan reference for those secrets and store it using a proper key store backend. Currently, Castellan supports Barbican and also Hashicorp Vault as backends options. For this scenario, we will be looking for using Vault as a chosen solution, since we can point to an external Vault server with no internal dependencies to other OpenStack services, also for authentication and validation methods, since Barbican needs Keystone tokens as authentication method also we need to store the Barbican and Keystone secrets present in their configuration files.

Phase 2:

Finally, we should use some deployment tool like Ansible to create those secrets and store them properly on Vault following the Castellan interface and inject those secrets in the configuration files. So, later, we will be able to restore it properly in the configuration files, with any necessary manual steps.

Consuming projects

Any OpenStack service which have some secrets in their configuration files, such as Glance, Nova, Keystone, Mistral and so on.


  • Encrypt the configuration files:

Which requires decryption keys and makes difficult to update configurations

  • Configuration Management DB (CMDB):

Need to secure database connection credentials

  • Other types of providers can be included as a key store solution since those providers implements the Castellan interface, such as Vault or a KMIP device

Security impact

This change wants to make OpenStack services passwords and credentials management more secure, removing the plaintext passwords in the OpenStack services configuration files by using a secure and encrypted alternative following the Castellan interface for secrets management.

Configuration Impact

For the first phase of this work, the operator can update their configuration files to point to the password reference and no more using plaintext passwords. Although, after the second phase with the Puppet and/or Ansible that change will be made automatically by those tools.



Primary assignee:


Other contributors:

dhellmann moguimar spilla


We are targetting the Phase 0 for Rocky-3 and Phase 1 and Phase 2 for Stein.

Work Items

  • Implement oslo.config driver for URI

  • Implement oslo.config driver for Castellan

  • Documentation

Documentation Impact

We should document how to update the OpenStack Services configuration file to use the proper password references instead of the plaintext passwords.


Oslo PTG discussion: Meetings logs: Phase 0 on Rocky Release:


This work is licensed under a Creative Commons Attribution 3.0 Unported License.