nix: issue the swarm-services leaf from bao's pki mount

The `pki` mount had no issuer and no principal could log in to it, so the
swarm's service certificates were still minted by two openssl hops from a
root key on disk. Close both halves and retire the openssl path with them.

The mount now generates its own root, once. The granting unit asks bao
whether an issuer already exists (`bao list pki/issuers`) before calling
`pki/root/generate/internal`, so a rebuild or a reboot re-asserts the role
and the grant without touching the anchor — a root that changed per boot
would invalidate every certificate issued under it and every browser
taught to trust it. The guard asks the store rather than looking for a
marker file on this host's disk: a file is a claim about a mount that may
have been restored from a snapshot or disabled and re-enabled underneath
it.

`swarm-services-issuer` stops being an inert policy. A fourth cert-auth
role attaches it, following the shape the controller, the publisher and
matrix-ctl already use, and glue-bao-tls.nix signs the leaf carrying its
CN — that credential is what opens the mount, so it cannot come out of it.

`swarm-services-cert.service` logs in with that leaf, calls
`pki/issue/swarm-services`, and writes the result to the path
hive-tls.nix already wrote and the gateway already copies from. The
sub-CA layer does not move; it stops existing. The role's
`allowed_domains`, read from the same `swarm.serviceDomains` the SANs
come from, enforces at issue time what the sub-CA encoded in x509
`nameConstraints`, and with the root inside the mount there is nothing
left for an intermediate to be an intermediate of.

Not a flag day: the issuing root is published beside the leaf as
`swarm-services-root.pem` (0644) and joins `trust-bundle.pem`, where the
swarm root still sits. A leaf chaining to the old sub-CA and one issued
by the store both verify against the same bundle, so hives can be
rebuilt in any order. The same file is what an operator hands a browser
— readable without a store login, which matters because every listener
demands a client certificate.

The eval-time warning about uncovered service names is gone rather than
reworded. It fired on "this host does not hold the swarm root key", which
was the reason a hive could end up serving its own leaf on a
swarm-service name. Every hive now asks the store with its own identity,
so that stopped being the thing that decides.

Closes #4586
This commit is contained in:
atlas 2026-09-21 17:59:22 +02:00 committed by mara
commit f4df4fc4a9
10 changed files with 700 additions and 315 deletions

View file

@ -45,7 +45,7 @@ neither is a renaming of the other.
| --------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------ | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| swarm root CA cert | `swarm-ca.nix` first-boot unit, when the operator sets `autoConfigure` | `/var/lib/swarm-ca/root.pem` | operator copies the **cert** in; it's public |
| swarm root CA key | same unit | `/var/lib/swarm-ca/root-key.pem`, `0600` | stays on whichever host holds it — see the constraint below |
| swarm-services sub-CA (cert + key) | `swarm-ca.nix`, signed by the root | `/var/lib/swarm-ca/services-ca{,-key}.pem` | issued where the root lives |
| swarm-services root CA (cert + key) | `swarm-bao.nix`'s granting unit, inside the store's `pki` mount | the **key** never leaves the mount; the **cert** is published at `/var/lib/swarm-bao-services-pki/services-root.pem` (0644) and at `/var/lib/hive-tls/swarm-services-root.pem` on every hive | nothing to copy — every hive receives the cert with the leaf it asks the store for |
| authelia session, JWT and storage-encryption keys | authelia's first-boot unit, in-container | `/var/lib/authelia-swarm/{session,jwt,storage-encryption}.key` | generated in place; nothing outside that container reads them |
| authelia OIDC HMAC key | same unit | `/var/lib/authelia-swarm/oidc-hmac.key` | same |
| authelia OIDC issuer key (RSA) | same unit | `/var/lib/authelia-swarm/oidc-issuer.key` | same — relying parties verify against the **public** half at `/jwks.json` |