`deliver` read the value out of the secret store and wrote it itself, as the
`hive-core` user, at 0600. The file lands in a directory owned by the agent,
so it arrived owned by `hive-core` — the agent's matrix daemon woke on it
appearing and could not read its own credential. `priv_client::write_agent_
matrix_token` already existed and already had two callers; this was the one
path that did not use it.
hive-priv now owns the filename too, so the name the daemon's path unit globs
for is decided in one place instead of being built identically in two.
That move exposed a disagreement worth fixing rather than routing around.
The secret store accepts `[A-Za-z0-9_-]` for an account name; hive-priv's
`validate_name_chars` accepts lowercase, digits and hyphen only. An account is
an attribute name in `hyperhive.matrixAccounts`, typed `attrsOf` with no
charset constraint, so `Ops_Relay9` is a key an operator can already have
written — and it would have read out of the store and then failed to land.
So hive-priv grows `validate_account_name` rather than widening the existing
one: an agent name is an `Ident` and lowercase by design, an account name is an
attrset key, and one validator serving two name domains is what let them drift.
The test that caught this came from `credential.rs`, which used to build the
path. It moves to hive-priv with both of its controls intact, because the
controls are the point — they assert which names must be ACCEPTED, and a
validator narrower than the store's passes every rejection case. A second
moved test pins the `matrix-token` prefix where the name is now built; the
old one would have kept passing while asserting a function that no longer
decided anything.
Refs #3726
0dd807062c