Securing an install
公開更新
An install holds the credentials of every tenant's payment provider and mail server, the personal data of every reader, and the keys that seal them. This page is for the operator who keeps them safe: what the install relies on to keep them apart, and where each secret may go. How to replace each secret, and what two-step verification and the audit logs give you, are on the pages under In this section.
What keeps data apart
The database roles
No process connects to PostgreSQL as the administrative login the publiractl db commands use. Each part of the install connects as one of six roles that publiractl db roles creates, and each role reaches only what that part needs, as The database roles describes. The roles that answer readers and a tenant's staff are bound by row-level security to the tenant a request names, so a defect in those paths cannot read another tenant's rows, and the operators' password hashes and the platform's mail credentials are out of reach of every role but publira_platform and the worker role that sends the platform's mail. The tenant console's role reads the address the platform's mail is sent from, and nothing else of the platform's mail settings.
That only holds while each process has the connection URLs of its own roles and no others. Give the administrative login's password to the publiractl db commands alone, and never set a process's connection URL to that login or to a role it does not use.
The console APIs
publira server serves the tenant console's and the Platform Console's APIs under /rpc beside the public API, on the one port the edge forwards to. They are reachable only where the edge forwards them, and an edge configured as Routing says forwards them nowhere: web-admin and web-platform call them over the private network, and the edge answers them with a 404 on every host. Behind that, each of their requests is refused before it runs unless it carries an operator's session or the web service token, the few that run before there is a session — signing in, resetting a password, and confirming an email address — are limited per client or guarded by the server itself, and creating the Platform Console's first operator takes the web service token, which only the Platform Console's server sends. The web service token is therefore what stands between whoever reaches publira server and every tenant's catalog and the platform's list of readers: keep it to the processes the table below names.
Running the process the tenants' domains reach as publira server --role storefront, as the Overview describes, stays worthwhile beside the edge rule. The two are separate layers: the edge keeps the consoles' APIs off the internet, and --role storefront keeps the consoles' database logins and the web service token out of the process readers reach, so neither a defect in that process nor an edge that forwards the consoles' paths after all reaches them.
Where each secret may go
Give each secret only to the processes that read it. A process that does not need a value is one more place it can leak from.
| Secret | Set it on | Never on | What its holder can do |
|---|---|---|---|
| The secret encryption keys | publira server, publira worker, publiractl | The web apps | Open every credential the install stores, given a copy of the database |
The access token signing key, PUBLIRA_AUTH_JWT_SECRET | publira server | Everything else | Sign a session for any reader, member of staff, or operator |
Each web app's session key, PUBLIRA_AUTH_SECRET | That web app | publira server, publira worker | Read and forge that app's session cookies, which carry the user's access token |
| The cache revalidation token | publira server, publira worker, and every web app | publiractl | Drop any cached page, as often as they like |
| The web service token | publira server, web-admin, web-platform | web-storefront, publira worker | Read the catalog of any tenant, unpublished series included, and the platform's tenants, operators, and readers |
| The administrative login's password | The publiractl db commands | Every long-lived process | Everything in the database |
| Each role's password | The processes that connect as that role | The others | What that role reaches |
The web apps may share one session key, but give each its own, as the Compose file does: then replacing one signs out only that app's users.
Handing a secret to publiractl
publiractl never takes a secret as an argument. Give it one as a file, with the secret's --<name>-file flag, wherever the platform can mount secrets as files, as Kubernetes and Docker do under /run/secrets/. A file can be made readable by the one user publiractl runs as, and kept on a tmpfs. A value in an environment variable is inherited by every process started from the one that holds it, and can be read from /proc/<pid>/environ, from docker inspect or the orchestrator's description of the task, and from a crash report or debug dump that records the environment.
Use the secret's --<name>-env flag only on a platform that sets secrets as environment variables alone, such as Amazon ECS.
One set of secrets per install
Generate a fresh set of every secret for each install: production, staging, and every developer's machine. Two installs that share the access token signing key accept each other's sessions for any account whose ID exists in both, which a staging database restored from a production backup has for every account.
A copy restored from production can read its stored credentials only with production's encryption keys, and with them it holds production's SMTP account, payment provider keys, and every other credential its tenants saved. Run such a copy only where production's own secrets are allowed, and give it its own access token signing key, session keys, tokens, and role passwords.
In this section
- Rotating secrets: replacing the secret encryption keys, a database role's password, and the signing keys and tokens.
- Two-step verification: requiring it of tenant staff and of platform operators, and what to do when a second factor is lost.
- Audit logs: what the Platform Console's log and a tenant's log record, and what neither records.
Reporting a vulnerability
A vulnerability in Publira itself is reported privately, as the security policy describes, never in a public Issue.