jcp: a chained decision enforces caveats, and a chain cannot drop one #300

Merged

dcharlot merged 1 commit from fix/jcp-chained-caveats into main 2026-10-17 16:03:08 -04:00

Conversation 0 Commits 1 Files changed 4 +322 -49

dcharlot commented 2026-10-17 10:44:21 -04:00

Owner

Copy link

The defect

Runtime::decide_chained evaluated no caveat at all: not the leaf's, and not any ancestor's.

It is the decision path behind:

• the jcp/1 wire endpoint (jcp-wire, SPEC §11)
• jcp-channel
• jouleclaw-jcp
• joule-code-jcp

All of these present a chain, even a one-link chain for an undelegated grant. So PayloadIs, NotBefore, NotAfter, CallerIs, ActionIn, MaxCostUj and ModelIn were enforced only on the single-grant decide/authorize path. That path is the only one C24 exercises.

Separately, verify_chain checked capability, budget, expiry and depth at each hop, but not caveat inheritance or the money ceiling. attenuate refuses a child that drops a caveat or widens its money ceiling. A chain minted by hand, outside attenuate, verified anyway and conveyed the authority the caveat withheld.

The fix

• verify_chain: refuses a hop that drops a parent caveat (caveats_narrow) or widens or drops its money ceiling (funds_narrows). Both are denied attenuation-violation.
• check_chained: the chained decision's non-budget checks, moved into one function that now evaluates every link's caveats. Cost-dependent ones are evaluated when the cost is known.
• authorize_chained / charge_chained: the two-phase metered path for a chain.
  • Authorize debits nothing and reports the least any link has left.
  • Charge debits every link, so siblings share their parent exactly as in decide_chained.
  • A per-call breach is reported with the joules still debited.
• SPEC §4.2 states both rules and the chained metered path, and C7 covers an inherited caveat and a dropped one.

The mesh steward will use the two-phase chained path to accept delegated grants. That is the next PR.

Checked

On the build host:

• jcp-rs: 501 tests pass, four of them new. The conformance suite passes all checks, including the extended C7.
• Vectors: every vector gen-vectors writes is byte-identical to jcp/conformance/v1.
• Consumers: jouleclaw-jcp, joule-code-jcp and sandbox-jcp pass their tests. mesh, joule-ui, joulehook and jouledesk compile.
• Mutations: each fails tests:
  • chains ignoring caveats (also fails C7)
  • verify_chain allowing a dropped caveat (also fails C7)
  • a charge that debits only the leaf
• Clippy: nothing new; the two slice::from_ref warnings predate this change.

🤖 Generated with Claude Code

## The defect `Runtime::decide_chained` evaluated **no caveat at all**: not the leaf's, and not any ancestor's. It is the decision path behind: - the `jcp/1` wire endpoint (`jcp-wire`, SPEC §11) - `jcp-channel` - `jouleclaw-jcp` - `joule-code-jcp` All of these present a chain, even a one-link chain for an undelegated grant. So `PayloadIs`, `NotBefore`, `NotAfter`, `CallerIs`, `ActionIn`, `MaxCostUj` and `ModelIn` were enforced only on the single-grant `decide`/`authorize` path. That path is the only one C24 exercises. Separately, `verify_chain` checked capability, budget, expiry and depth at each hop, but not caveat inheritance or the money ceiling. `attenuate` refuses a child that drops a caveat or widens its money ceiling. A chain minted by hand, outside `attenuate`, verified anyway and conveyed the authority the caveat withheld. ## The fix - **`verify_chain`:** refuses a hop that drops a parent caveat (`caveats_narrow`) or widens or drops its money ceiling (`funds_narrows`). Both are denied `attenuation-violation`. - **`check_chained`:** the chained decision's non-budget checks, moved into one function that now evaluates **every link's** caveats. Cost-dependent ones are evaluated when the cost is known. - **`authorize_chained` / `charge_chained`:** the two-phase metered path for a chain. - Authorize debits nothing and reports the least any link has left. - Charge debits every link, so siblings share their parent exactly as in `decide_chained`. - A per-call breach is reported with the joules still debited. - **SPEC §4.2** states both rules and the chained metered path, and **C7** covers an inherited caveat and a dropped one. The mesh steward will use the two-phase chained path to accept delegated grants. That is the next PR. ## Checked On the build host: - **jcp-rs:** 501 tests pass, four of them new. The conformance suite passes all checks, including the extended C7. - **Vectors:** every vector `gen-vectors` writes is byte-identical to `jcp/conformance/v1`. - **Consumers:** jouleclaw-jcp, joule-code-jcp and sandbox-jcp pass their tests. mesh, joule-ui, joulehook and jouledesk compile. - **Mutations:** each fails tests: - chains ignoring caveats (also fails C7) - `verify_chain` allowing a dropped caveat (also fails C7) - a charge that debits only the leaf - **Clippy:** nothing new; the two `slice::from_ref` warnings predate this change. 🤖 Generated with [Claude Code](https://claude.com/claude-code)

dcharlot added 1 commit 2026-10-17 10:44:21 -04:00

jcp: a chained decision enforces caveats, and a chain cannot drop one ... f0952309c1

`decide_chained` evaluated no caveat at all: not the leaf's, not any
ancestor's. It is the decision path behind jcp-wire's endpoint (§11),
jcp-channel, jouleclaw-jcp and joule-code-jcp. Those always present a
chain, even a one-link chain for an undelegated grant. So `PayloadIs`,
`NotBefore`, `NotAfter`, `CallerIs`, `ActionIn`, `MaxCostUj` and
`ModelIn` were enforced only on the single-grant `decide`/`authorize`
path, which the conformance suite exercises.

Separately, `verify_chain` checked capability, budget, expiry and depth
at each hop, but not that a child carries its parent's caveats or no
wider money ceiling. `attenuate` refuses both when it mints. A chain
minted by hand verified anyway and conveyed the authority the caveat
withheld.

- `verify_chain` refuses a hop that drops a parent caveat
  (`caveats_narrow`) or widens or drops its money ceiling
  (`funds_narrows`). Both are denied `attenuation-violation`.
- The chained decision's checks move into `check_chained`, which now
  evaluates every link's caveats. Cost-dependent ones are evaluated when
  the cost is known.
- `authorize_chained` / `charge_chained` add the two-phase metered path
  for a chain. Authorize debits nothing and reports the least any link
  has left. Charge debits every link, so siblings share their parent as
  in `decide_chained`, and a per-call breach is reported with the joules
  still debited.
- SPEC §4.2 states both rules and the chained metered path. C7's
  conformance check covers an inherited caveat and a dropped one.

Checked on the build host:
- jcp-rs: 501 tests pass, and the conformance suite passes all checks.
- Every vector gen-vectors writes is byte-identical.
- jouleclaw-jcp, joule-code-jcp and sandbox-jcp pass their tests.
- mesh, joule-ui, joulehook and jouledesk compile.
- Mutations each fail tests: chains ignoring caveats, `verify_chain`
  allowing a dropped caveat, and a charge debiting only the leaf.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

dcharlot referenced this pull request from a commit 2026-10-17 11:07:15 -04:00

Merge #300 into the mesh branch: steward-held chains need authorize_chained

dcharlot referenced this pull request from a commit 2026-10-17 11:07:15 -04:00

mesh: a grant is spent only by its issuer, at the steward it names, and its spend survives a restart

dcharlot referenced this pull request 2026-10-17 11:07:18 -04:00

mesh: a grant is spent only by its issuer, at the steward it names, and its spend survives a restart #301

dcharlot referenced this pull request 2026-10-17 11:42:18 -04:00

jcp: a chain is bounded in money on every link, and a delegated grant is never decided alone #304

dcharlot referenced this pull request from a commit 2026-10-17 11:48:10 -04:00

Merge #300 into the mesh branch: steward-held chains need authorize_chained

dcharlot referenced this pull request from a commit 2026-10-17 11:48:10 -04:00

mesh: a grant is spent only by its issuer, at the steward it names, and its spend survives a restart

dcharlot referenced this pull request 2026-10-17 11:57:22 -04:00

mesh: a cut journal is caught by the receipts the steward handed out, and the receipt chain survives a restart #306

dcharlot merged commit 42096c1e09 into main 2026-10-17 16:03:08 -04:00

dcharlot referenced this pull request from a commit 2026-10-17 16:03:10 -04:00

Merge pull request 'jcp: a chained decision enforces caveats, and a chain cannot drop one' (#300) from fix/jcp-chained-caveats into main

dcharlot referenced this pull request from a commit 2026-10-17 17:14:49 -04:00

mesh: a grant is spent only by its issuer, at the steward it names, and its spend survives a restart

Sign in to join this conversation.

Reviewers

No reviewers

Labels

Clear labels

No items

No labels

Milestone

Clear milestone

No items

No milestone

Projects

Clear projects

No items

No project

Assignees

Clear assignees

No assignees

1 participant

Notifications

Subscribe

Due date

The due date is invalid or out of range. Please use the format "yyyy-mm-dd".

No due date set.

Dependencies

No dependencies set

Reference

Transaction-Science/open-standards!300

No description provided.