We have recently added some additional features to MemCachier. In brief, you can now have multiple sets of credentials for a cache, can rotate credentials, and can restrict some capabilities on a per-credential basis. These features are all controlled from the Credentials panel of the MemCachier dashboard for your cache:
The features described in this article are also explained in the MemCachier documentation.
Caches may now have multiple sets of username/password credentials. The credentials for a cache are listed in the table in the Credentials panel on your cache’s analytics dashboard. New credentials for a cache are created using the Add new credentials button, and credentials may be deleted using the X button next to the credentials row.
One set of credentials is distinguished as primary, while the rest are secondary credentials. For caches provided through our add-on with a third-party provider (e.g., Heroku or AppHarbor), the primary credentials are linked to the configuration variables stored with the provider. That is, these are the credentials you see when you look at your application’s environment. Secondary credentials can be promoted to primary using the up-arrow button next to the credentials row. When secondary credentials are promoted to primary, the username and password for the credentials being promoted are pushed to the provider’s configuration variables.
In practice, this means that you can rotate the credentials for a MemCachier cache associated with a Heroku app by creating a new set of credentials and promoting them to primary. This will push the new username and password to the MEMCACHIER_USERNAME and MEMCACHIER_PASSWORD configuration variables in your Heroku app, and trigger a restart so your application will pick up the new MemCachier credentials.
This ability to have both a primary and many secondary credentials lets you to rotate your credentials with zero downtime!
We’ve further enhanced multiple credentials by adding a security extension to our memcache implementation: capabilities! These control the operations available to a client once they authenticate with the chosen credentials.
Each set of credentials for a cache has associated write and flush capabilities. By default, new credentials have both capabilities, meaning that the credentials can be used to update cache entries and flush the cache via the memcached API.
You can restrict a client to read-only access by switching off the write capability for its credentials, and prevent a client from using the memcached API to flush your cache by switching off the flush capability.
Per-credential capabilities are managed using the checkboxes on each credential row in the Credentials panel: if the checkbox is checked, the credential has the capability; if not, the capability is disabled for that credential.
Dashboard SSO rotation
The MemCachier dashboard for your cache is accessed via a persistent unique URL containing a cache-specific single-sign-on hash. For security, you may wish to rotate this cache-specific hash to generate a new unique URL for the cache dashboard. The Rotate SSO secret button in the Credentials panel of the dashboard does this hash rotation. Pressing this button generates a new hash and redirects the dashboard to the resulting new unique URL.
Security @ MemCachier
We value security and hope that you find these new features valuable to improve your own practices. As always, for a guide to MemCachier’s own internal security practices, see our documentation.