A module may declare a short `slug`; the mesh derives mesh_<node>_<slug|name> and
refuses at assignment (naming the slug as the remedy) when it would still overflow —
identityLimit is now 20, an S3 access key's, the tightest of the backends a login
reaches (04-ISSUES/010). The slug rides the grant so the provider derives the same
login the consumer does, even across nodes. CheckIdentity is now wired, in grantsFor.
Also, the minted secret shrinks to 40 chars (30 bytes) from 43: an S3 secret key is
8-40, the same fit-the-tightest-backend rule on the credential's other half.
Claude-Session: https://claude.ai/code/session_01LrgweAeERJYBg88c5cKDzF
The last of the four gaps ADR 0024 names. Everything the mesh handles
today it generated itself, sealed to both ends, and discarded. An API key
for a hosted service comes from a person, and carrying it needs a verb
the mesh did not have.
Accept seals it on the way in and keeps no plaintext — the same storage
and the same property as a generated one, only a different origin. That
is the whole difference from the arrangement being replaced, where an
operator-supplied key sits in a column the control plane can read, which
makes a copy of the database a copy of every account the mesh touches.
The consequence is deliberate: the mesh cannot show it back. Somebody who
loses the key gets a new one from wherever it came from. There is no
reveal and there cannot be one, because a mesh that can reveal a secret
is a mesh that holds it — asserted as a test, because it is a property
somebody will eventually ask to break.
An empty value is refused. A credential that exists, authenticates
nowhere and looks exactly like a working one is the failure this whole
mechanism is arranged to prevent.
HAL keeps env vars in the registry, encrypted at rest. Its own tooling
records what that bought and what it did not. `secret_locate` matches by
value rather than by name — because the same password sits in
mesh_provisions, in module_env, in each node's .env in plain text, and
inside every connection string composed from it, and its documentation
says those URL copies "are often the only copies actually in use". And a
query against the encrypted column returns zero rows and proves nothing,
so auditing moved to the decrypted copies on the nodes.
Two faults there, and encryption at rest addresses neither: the control
plane can read what it stores, so a copy of the database is a copy of
every credential; and one secret has many homes with nothing tracking
them.
So here the mesh generates a password, seals it to each end with keys
those nodes generated, stores both blobs, and discards the plaintext. It
cannot read what it holds. Neither can the broker relaying it. And
nothing is composed centrally — a connection string is assembled on the
machine that needs one — so no copy is ever minted in a shape nothing
tracks. `Compromise of a node is compromise of that node` (ADR 0004) is
now true of secrets, not only of identity.
Two files rather than one, because the mesh cannot compose a document
containing a value it discarded: `binds` carries the readable facts,
`secrets` carries the credential alone. The readable half stays readable
in the declaration; the secret half changes only when the secret does,
which makes restart-on precise. The provider gets a directory, one file
per consumer, for the same reason.
It is made once and kept — regenerating per declaration would restart
both ends on every push, and the password a provider was told to create
would never be the one its consumer was given. It is remade when either
end's sealing key changes, and both ends learn the new one in the same
push, so there is no window where half the mesh holds a dead credential.
Two tests found passing for the wrong reason, both caught because their
injection came back clean:
- the provider's copy was asserted non-empty, which reads the same
whichever column is selected. It now opens the blob with the
provider's own key.
- RotateSecret deleted and re-created; the re-create was dead, because
the next read makes one anyway. Removed, and a second path to the same
act is how two ends come to disagree.
And one real fault: three places built a declaration, and the one behind
`--json` predated credentials, so it silently produced a declaration
missing them — a difference between what `plan` showed and what anything
reading `--json` got. There is one path now.
jschoubben