A hive reads its agents' credentials with its own certificate, and nothing
said which paths that certificate may read, so the read half of a delivery
answered 403.
The grant is wide on purpose. An agent's path does not name the hive
hosting it -- agents move -- so a per-hive grant has to be an enumeration
the controller re-emits whenever the roster changes, and an enumeration
that can drift or land out of order advertises a boundary it does not
hold. A wide grant that says what it is beats a narrow one that only looks
narrow. mara's call, on the PR: rather a too-lax scope than one that
pretends to be strict.
What that buys, beyond honesty: the document is identical for every hive
and depends on nothing, so it is written once at startup beside the rest of
a hive's provisioning instead of on every declaration. No derived state, no
re-emission, and the ordering hazard that came with one stops existing.
What still holds is read-only. A hive cannot write an agent's credential,
so it cannot hand itself an agent's identity, and the grant reaches nothing
in the store outside the agent-credential prefix.
The fact is documented where someone meets the boundary rather than only in
this message, and the two ways to narrow it later -- scope per hive, or
give agents their own store identity -- are tracked.
The renderer beside this produces a hive's read policy; nothing could put
one in the store. `read`/`write` are KV v2 verbs and a policy is not a
secret, so this is a second endpoint rather than another path.
A whole-document write, because the store has no merge verb: the caller
renders from the current agent set, so a stanza missing from the render
is a grant that is meant to be gone.
The controller writes an agent's credential; the hive reads it back with its
own token. Nothing says which paths that token may read, so the read half of
a delivery has no identity at all and answers 403.
This is the pure half of the fix: the policy text is a function of a hive name
and its agent set, so the shape can be asserted with no store to talk to.
One stanza per hosted agent rather than a prefix grant. An agent's credential
path does not name the hive hosting it -- deliberately, since agents migrate --
so "this hive's agents" has no prefix expression and must be enumerated. The
grant is read-only: the controller mints these and never reads one back.
The paths come from MOUNT and AGENT_PREFIX rather than literals, so the policy
cannot drift from the module that builds the paths it grants.
checked_segment runs before any name reaches HCL. That is policy injection
rather than path traversal -- a name can close a stanza and open a wider one --
so the test carries a real injection string, paired with the reachable-charset
control that stops it passing by refusing everything.
An empty agent set renders an empty policy, which grants nothing.
Closes#4124.
The controller's policy granted only the bootstrap paths -- hive cert-auth
roles and hive ACLs. #4113 then made it a secret WRITER, and nothing related
the grants to the paths the code writes, so every matrix token provision
answered 403. The two halves landed on different issues and neither looked
wrong on its own.
`secret/data/` is KV v2's ACL prefix and is absent from the path the code
passes, so matching `swarm-secret-client`'s spelling literally would have
granted nothing. Write-only: the controller mints these and never reads one
back, and a read capability would let it recover every agent's credentials
rather than only replace them.
The gate is the point. Two module-eval arms -- the grant exists and is not
a broader wildcard, and its capability list is pinned whole, because an
ADDED capability is what a presence check misses -- plus a test in path.rs
pinning MOUNT/AGENT_PREFIX and naming the nix file, since renaming either
constant is a silent 403 rather than a compile error.
setup.md carried two warnings this makes false: that nothing in the tree had
ever authenticated to the store, and that no deployment shape mints a leaf
whose CN reads swarm-controller. glue-bao-tls.nix has minted one since #3726
item 1.
mara, reviewing the previous commit: "the field is specific to matrix, why
add it to the general struct". She is right, and the answer is that there was
no general struct — `Credential` had one consumer, the crate's only path
builder was `matrix_account`, and `value` is pinned by
`glue-matrix-bao-token.nix`, a matrix unit. It was matrix's throughout,
wearing a general name; adding `homeserver` is what made that visible.
`client` now moves whatever type a caller names and decodes nothing itself.
That is forwarding rather than machinery: `vaultrs::kv2::read`/`set` are
already generic over the payload.
The matrix agreement moves to its own module holding both halves — where a
credential lives (`account_path`, was `path::matrix_account`) and what the
object at that path holds. `path` keeps only what every path obeys, so a
second kind of swarm secret becomes a module beside `matrix` rather than
another optional field on a struct it shares. argus raised the same collision
from the other direction on #4092: two mutually-exclusive `Option`s modelling
one concept is the failure mode this forecloses.
`checked_segment` stays public in `path`: hive-priv builds an on-disk path
from the same names and must accept the same charset.
Behaviour is unchanged. The compatibility properties move with the struct —
`Option` is what lets a pre-`homeserver` stored object decode, and
`skip_serializing_if` is what keeps a token-only object free of
`"homeserver":null` for that nix reader.
Refs #3726
A delivered matrix account needs two things: the token and the homeserver it
belongs to. Only the token was stored, so the homeserver had to ride on the
queue notice — and a notice is not persistence. Re-delivering a credential
(agent moved, hive re-provisioned, token rotated) has to reconstruct it from
somewhere, and there is nowhere; keeping it separately at swarm level would be
a second store for one logical object, free to drift from the first.
So `Credential` grows a `homeserver` field and `read`/`write` carry the whole
object rather than a bare string.
`value` keeps its name. `nix/host-modules/glue-matrix-bao-token.nix` reads the
store with `bao kv get -field=value` and is the only nix reader of it, checked
rather than assumed — so this had to be an addition, never a rename.
Two compatibility properties, both of which fail silently if broken:
KV2 keeps every prior version, so objects written before this field existed
are still decoded by this type. What tolerates their absence is the field
being `Option` — a bare `String` would not fail as a migration, every stored
credential would become unreadable at once. The new test pins that, with a
presence control so the arm is about absence being tolerated rather than the
field being ignored.
`skip_serializing_if` keeps a token-only credential serialising to exactly the
bytes the previous version wrote, with no `homeserver` key rather than a null,
which is what that nix reader would otherwise trip over. The existing test
pinning `{"value":"t"}` proves it and became the control for free.
Mutation testing earned its place here: `#[serde(default)]` was in the first
draft and its comment claimed it was what made old objects decode. Dropping it
changed nothing — serde already decodes a missing field to `None` for an
optional type — so the attribute was redundant and the comment was wrong about
its own mechanism. Both removed rather than left to mislead the next reader.
The delivery half needed no change: `write_agent_matrix_token` already took a
homeserver and already wrote the `matrix-account-<name>.json` sidecar beside
the token. `deliver` simply stops passing `None`. A credential stored without
one still works exactly as before — no sidecar, and the account needs a
configured entry.
Refs #3726
`token_path`'s doc claimed the compiler was the check and that nothing had to
remember to perform one. True of `agent`, which is an `Ident`. Not true of
`account`, a bare `&str` concatenated into the filename — safe only because
`deliver` happened to validate it first, which is the caller-must-remember
pattern the comment denied.
Observably a no-op today: the one call site already rejects a bad account
before reaching here. What changes is that the signature now enforces what the
comment asserted, so a second caller cannot skip it.
The check is `path::checked_segment`, made public rather than reimplemented.
Two copies of a charset are two charsets: they agree until one is edited, and
the day they diverge a name is legal in the store and not on disk.
An account name cannot simply become an `Ident` the way an agent name is:
it is an attribute name in `hyperhive.matrixAccounts`, so uppercase and
underscore are already configurable, and narrowing that is a decision rather
than a refactor. The new test's controls pin both.
Found by argus reviewing the merged PR.
The only one of the 28 without one. Records the things a reader cannot get
from the source: why the field name is pinned by a literal-string test (its
other end is a shell line in a nix module, unreachable from any Rust test),
why the BAO_ spellings are read explicitly rather than left to vaultrs's
VAULT_ defaults, and that cert_role is the hive's own name because the
cert-auth role matches on the CN the glue module mints.
mara ruled (a) on #3726: a thin workspace crate over `vaultrs` rather than
keeping bao access in nix and having each end trigger units. The HTTP is the
SDK's job; what this crate owns is the things the controller and a hive must
say *identically*, and which have no other home because neither end is senior
to the other.
Three such agreements:
`path::matrix_account` builds where a credential lives. It is fallible rather
than a `format!`, because both names reach it from elsewhere -- the agent name
from the topology, the account name from an agent's own config -- and a `/` or
`..` in either does not produce a malformed path, it produces a valid path to
a *different agent's* secret. The charset mirrors the KV bucket-name rule.
`Credential`'s `value` field is not a free choice: glue-matrix-bao-token.nix
reads the store with `bao kv get -field=value`, so the name is load-bearing
for a consumer no Rust test can reach. A test pins the serialised shape.
`client::Settings` reads BAO_ADDR / BAO_CLIENT_CERT / BAO_CLIENT_KEY /
BAO_CACERT explicitly instead of letting vaultrs fall through to its own
defaults, which look for VAULT_ADDR / VAULT_CLIENT_CERT / VAULT_CLIENT_KEY.
Every unit in this tree sets the BAO_ spellings, so the defaults would yield a
client with no identity at all -- surfacing as a TLS handshake failure, which
names neither the missing variable nor the reason.
The env read is split from the connect so every misconfiguration arm is
testable without a reachable store and without touching process-global env.
Dependency impact, measured against the lock at forge/main rather than assumed:
native-tls 0 -> 0, openssl-sys 0 -> 0, one reqwest (0.13.4) which vaultrs
shares, and 10 new crates that are all derive/proc-macro helpers.
Refs #3726
