The bundled reference Rego (`zddc-server --print-rego`) modeled the read-ACL
cascade only, but its header claimed to "mirror the internal decider exactly,
validated on every CI run." It is verb-blind, role-blind, WORM-blind, and
admin-blind: an external-OPA deployment (ZDDC_OPA_URL=http(s)/unix) loading it
granted writes/deletes to read-only principals and ignored WORM zones. The
parity tests never exercised a write action, a role principal, a WORM level, or
is_active_admin — so the divergence shipped silently behind a false "mirrors
exactly" claim.
Make both shipped policies fail-closed instead of falsely-complete:
- access.rego / access_federal.rego: gate every cascade grant on a read action
(empty/absent == read); non-read actions fall through to default-deny.
access.rego honors the single is_active_admin bypass (the one write-capable
principal); access_federal.rego deliberately has none (strict AC-6).
- Rewrite the access.rego / access_federal.rego / rego.go headers: these are
read-ACL SKELETONS, NOT a tested mirror of the internal decider; operators
must add write/WORM/role/admin semantics before granting writes.
- policy.go: fix the stale AllowInput doc claiming the internal decider "treats
read and write identically — any allow grants full CRUD" (it honors the
action verb, with the WORM clamp and admin/elevation bypass applied).
Tests:
- rego_failclosed_test.go: pins the contract — reads allowed, every write verb
denied, active-admin writes allowed (commercial) / denied (federal).
- embedded_neutral_test.go: pins that EmbeddedDefaults() carries no top-level
worm: and no role members — the invariant that makes policy.SerializableChain
dropping PolicyChain.Embedded behavior-neutral (a latent wire-contract gap).
Existing read-cascade parity + federal-divergence tests stay green; full Go
suite + vet pass. The default in-process InternalDecider is unaffected.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Editing a .zddc you administer no longer requires toggling admin mode.
Elevation becomes purely additive — it only adds the WORM/destructive
overrides ("things you otherwise couldn't do"), never a prerequisite for
authority you already hold.
Mechanism: a new zddc.IsConfigEditor(chain, email) reports STANDING
config-edit authority — being a subtree admin (admins: cascade) OR holding
the `a` verb — without the elevation gate. InternalDecider.Allow grants
VerbA on that basis ABOVE the WORM clamp: config is not WORM-protected
data, and VerbA only ever authorises .zddc/.zddc.zip/role mutations, never
write/delete of records (those stay clamped + elevation-gated). The full
WORM/ACL bypass (IsActiveAdmin) is unchanged — still admins: + Elevated.
This flows for free to the client: EffectiveVerbsFromChainP loops
ActionAdmin through the decider, so /.profile/access + cap.has(node,'a')
light up the .zddc form editor with no client change, and ServeZddcFile
already gates raw .zddc reads on directory read ACL (config is visible).
A standing subtree admin can thus rewrite their subtree's policy
(admins:/ACL/roles) un-elevated — bounded to their scope (authority
cascades down only, never up), logged, and unable to touch WORM data or
secrets without elevating. That's "admin of X = owns X's policy."
Tests: new TestStandingConfigEdit (decider matrix incl. WORM-transcending
config-edit + data-write still gated); updated the old "un-elevated admin
cannot edit .zddc" invariants (TruthTable, ZddcPut/DeleteMatrix,
NoSilentBypass now scoped to WORM/out-of-scope, profile PathVerbs) to the
new model. Full suite green.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Completes the migration. The embedded per-depth tree (internal/zddc/defaults/)
is now the sole source of the shipped baseline; defaults.zddc.yaml is deleted.
- EmbeddedDefaults() assembles the tree (no yaml). show-defaults now emits a
.zddc.zip (per-depth, "*" wildcard members) via EmbeddedDefaultsZip() —
operators redirect it to <ROOT>/.zddc.zip (or any directory) and edit/add/
delete individual members.
- Dropped EmbeddedDefaultsBytes; reworked the dumpable test to validate the
emitted zip; removed the now-redundant tree-vs-yaml oracle (the Layer-2
matrix is the ongoing behavioral guarantee, and it stays green).
- Swept stale "defaults.zddc.yaml" comment references to the embedded tree.
- GRAMMAR.md §1/§6 updated: .zddc.zip is a policy bundle mountable at ANY
directory (subtree mount; inherit:false + acl.inherit:false = island); the
shipped baseline is the embedded bundle at the root.
Net of the 6-phase migration: policy is per-depth .zddc files in a .zddc.zip
that an operator can drop at any level to override the cascade; the engine
(Assemble + the unchanged walker) enforces it. Full Go suite + matrix green.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Add a `verbs` field (canonical "rwcda" subset) to every directory
listing entry, computed via a new
`policy.EffectiveVerbsFromChainP(ctx, d, chain, p, path)` helper that
routes each of the five actions through the decider and unions the
allowed bits — so an external OPA's overrides surface in the wire
field, and active-admin elevation produces the full grant.
Semantics:
- file entry: verbs from the parent dir's chain (files inherit;
they have no .zddc of their own). Same chain Writable uses.
- directory entry: verbs from the subdir's OWN chain, so a fenced
or extended .zddc inside it shows through.
- virtual entries (auto-own homes, canonical-folder placeholders,
workflow received/ window, table.yaml/form.yaml spec rows):
verbs computed against the would-be path's chain so client
affordances render correctly before any write materialises a
real folder.
Writable stays in lockstep with verbs for the transition window so
existing clients (markdown/yaml editor save buttons) keep working
unchanged. Clients should migrate to checking 'w' in verbs and let
Writable wither.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Four targeted test suites that pin the invariants exercised by the
preceding audit refactor. Closes the coverage gaps identified after the
admin-decider consolidation and the .zddc write-path fix.
internal/policy/principal_test.go (NEW)
TestAllowActionFromChainP_TruthTable — 11 cases × 5 actions = 55
assertions covering every (elevated × admin-at-level × action)
combination. Pins the IsActiveAdmin short-circuit: bypass requires
BOTH (in admins) AND Elevated; elevation alone confers nothing;
empty email never matches.
TestAllowActionFromChainP_AdminScopeDepth — root admin reaches every
path; subtree admin matches in their own subtree; subtree admin
does NOT match in a sibling subtree (the chain doesn't carry
sibling admins lists).
TestAllowActionFromChainP_BypassWinsOverWorm — elevated admin
escape hatch in WORM zones, plus the negative control that an
un-elevated admin does NOT bypass WORM.
internal/handler/auth_invariants_test.go (appended)
TestInvariant_ZddcPutMatrix — 16 sub-cases across (root / project /
subtree .zddc) × (root admin / subtree admin / non-admin /
anonymous) × (elevated / un-elevated). Locks down which principal
can PUT which .zddc.
TestInvariant_ZddcDeleteMatrix — 5 DELETE cases.
TestInvariant_UnelevatedAdminNoSilentBypass — 14 anti-bypass probes:
every (admin-flavour × probe-path) tuple where an un-elevated
admin must 403. Single bypass leak → loud test failure.
cmd/zddc-server/main_test.go (appended)
TestDispatchZddcWriteRouting — full dispatcher path coverage:
GET/HEAD route to ServeZddcFile (YAML or virtual placeholder);
PUT/DELETE route through the .zddc-leaf carve-out into
ServeFileAPI; intermediate .zddc.d/ segments still 404 at the
guard.
internal/handler/middleware_test.go (appended)
TestAccessLog_ChainAdminLevelAttribution — 7 cases pinning the
forensic record: root admin → chain_admin_level=0, subtree admin
in scope → chain_admin_level=N, subtree admin out of scope → -1,
un-elevated admin → -1, non-admin → -1, anonymous → -1.
Cross-checks active_admin == (chain_admin_level >= 0) so a future
refactor can't desync them.
92 new sub-cases total. Coverage delta on the policy package:
76.1% → 87.2%; AllowActionFromChainP 0% → 100%;
activeAdminForRequest 7% → 68%.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Single audit pass that removes pre-release back-compat, consolidates the
admin-policy decider, and fixes the .zddc write path.
Field removal — acl.allow / acl.deny:
- Drop ACLRules.Allow / Deny struct fields and mergeLegacyACL().
- Remove walker / lookups / validate / decider branches that read them.
- Migrate every test fixture (YAML strings and ACLRules struct literals)
to acl.permissions: { principal → verb-set }.
- Rewrite both bundled Rego policies (access.rego, access_federal.rego)
to traverse level.acl.permissions; rewrite parity-test helpers.
- Update create-project form (profile page) to collect permissions
instead of allow/deny lists.
Admin decider consolidation:
- Delete zddc.CanEditZddc — strict-ancestor rule retired. Subtree admins
own their own .zddc; the policy decider's IsActiveAdmin short-circuit
is the single bypass site.
- Migrate tablehandler.ServeTable to AllowActionFromChainP — closes the
same Forbidden bug already fixed for /browse.html.
- Drop AccessView.EditableParentChoices and treeEntry.CanEdit (always
true after the retirement). Profile page renders AdminSubtrees
directly for both lists.
- Drop the excludeLeaf parameter from AdminLevelInChain /
IsAdminForChain — no production caller passed true.
Dead code removed:
- policy.AllowWriteFromChain (zero production callers, zero tests).
- zddc.AllowedWithChain (zero production callers; tests deleted).
ModeStrict retirement — federal posture is OPA-only:
- Delete cascade_mode.go / cascade_mode_test.go and the ModeStrict
branches in cascade.go and acl.go.
- Drop --cascade-mode flag, CascadeMode config field, and the
InternalDecider.Mode field.
- Drop the mode parameter from every cascade helper:
GrantedVerbsAtLevel, AllowedAction, EffectiveVerbs,
EffectiveVerbsRange, RoleMembers, MatchesPrincipal,
MatchingPrincipals, WormZoneGrant, PolicyChain.VisibleStart.
- Strip cascade_mode from /.profile/config and
/.profile/effective-policy responses.
- Refresh README / ARCHITECTURE.md to describe federal posture as
"deploy OPA with access_federal.rego" (NIST AC-6); the bundled Rego
is the parent-deny-is-absolute variant. The in-process Go evaluator
implements only the commercial cascade.
Legacy redirects + .admin.css fallback:
- Drop /<dir>/.zddc.html → ?file=.zddc redirect and its test.
- Drop ?zip=1 retired comment + legacy test (handled by the
.zip virtual-URL path; covered by TestServeSubtreeZip).
- Drop .admin.css fallback in profile_assets.go — only .profile.css now.
- Refresh stale "retired" / "back-compat" / "legacy" comment markers.
.zddc write path fix:
- Dispatcher: route only GET/HEAD on .zddc URLs to ServeZddcFile; carve
.zddc out of the dot-prefix guard so PUT/DELETE/POST reach
ServeFileAPI. Before this, .zddc writes 405'd at ServeZddcFile and
the YAML editor's save flow had no live path.
- ServeFileAPI.resolveTargetPath: same .zddc-leaf carve-out so the file
API accepts the path; intermediate dot dirs (.zddc.d/) stay reserved.
- Listing: compute Writable per-file with ActionAdmin for .zddc
(matches the file API's gate) instead of ActionWrite for everything.
- Virtual .zddc placeholder: compute Writable via the same
parentActiveAdmin || ActionAdmin path. Was always false before.
- browse YAML editor canSave: exempt virtual .zddc — the synthetic
body is designed to materialize on PUT.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
The rule said: an admin granted in /<dir>/.zddc can edit deeper
.zddc files but NOT the one that grants their own authority.
Intended to prevent self-elevation, peer-addition, and delegator-
removal.
Three problems:
- "Add peers" isn't an attack — it's the common collaboration case.
Project creator can't grant a teammate access without bothering a
super-admin every time.
- "Remove the delegator" doesn't work. Root admin authority lives
in the ROOT .zddc and cascades down regardless of what's in
/<dir>/.zddc; subtree admins can't touch it.
- "Self-elevation" within a subtree is meaningless. They already
have rwcda there.
Replacement model: admins in /<dir>/.zddc OWN /<dir>/ and everything
beneath, including the .zddc itself. They can add collaborators,
modify ACLs, even remove themselves. Self-removal is a recoverable
footgun — root super-admins always retain authority via the root
cascade and can restore.
What stays:
- The admins: field as a load-bearing key (drives IsActiveAdmin
+ sudo-style elevation + WORM bypass).
- Bootstrap via root .zddc hand-editing.
- IsAdminForChain(chain, email, excludeLeaf bool) signature —
ModeStrict / NIST AC-6 deployments can still opt into the strict-
ancestor walk if they need it.
Tests flipped to match the new contract; ProjectCreate flow now
gives the creator real control over their project root.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Reads (apps resolution, directory listing, file GET, archive index,
profile pages, subtree zip, form render) used policy.AllowFromChain
with email — no admin-bypass branch fired even for elevated admins,
because IsActiveAdmin only landed in AllowActionFromChainP.
Symptom: elevated admin navigating to /browse.html got 403 because
the root cascade has no explicit read grants in my refactored root
.zddc (role memberships + admins only; no acl.permissions). The
app-resolution path's AllowFromChain didn't see admin status.
Fix: new policy.AllowFromChainP that forwards to
AllowActionFromChainP(action=read). Migrate every read-path caller
to the principal-aware variant. The decider's single bypass branch
now fires uniformly across read and write decisions.
Migrated:
cmd/zddc-server/main.go (9 sites)
handler/directory.go (1)
handler/archivehandler.go (2)
handler/zddcfile.go (1)
handler/formhandler.go (3)
handler/projectshandler.go (1; EnumerateProjects sig takes Principal)
handler/subtreezip.go (1)
fs/tree.go (1; uses already-built principal)
profilehandler.go:400 stays on AllowFromChain — it probes ACL for a
DIFFERENT email (the enumeration target, not the request principal),
so admin bypass on the request's principal doesn't apply.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Lays the rails for the consolidation refactor — the decider gains a
single admin-bypass branch at the top of InternalDecider.Allow, and a
new principal-aware entry point computes IsActiveAdmin from chain +
Principal.Elevated. No caller uses the new path yet, so behavior is
unchanged; lock-in tests stay green.
AllowInput.User.IsActiveAdmin bool // caller-computed bypass flag
AllowActionFromChainP(ctx, d, chain, p, path, action) (bool, error)
The decider's branch:
if input.User.IsActiveAdmin { return true, nil }
is the ONLY admin escape hatch in the package. Strict-ancestor rule
for .zddc edits is preserved inside AllowActionFromChainP via
IsAdminForChain(chain, email, excludeLeaf=true) when action==ActionAdmin.
Email-only entry points (AllowFromChain, AllowActionFromChain) leave
IsActiveAdmin=false implicitly — they're for read-path callers that
don't need admin bypass (directory listing, archive index, profile
read endpoints).
Next commits: migrate authorizeAction and plan-review's pre-flight
to AllowActionFromChainP, then delete the scattered IsAdmin/
IsSubtreeAdmin/CanEditZddc early-outs.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
WORM (write-once-read-many) is no longer a special folder type keyed
off the literal names "received"/"issued". It's a cascade key —
`worm:` on any directory's .zddc — with the ACL-shaped semantics the
user described.
Schema:
worm:
"doc-control@example.com": cr # email-glob or @role:name → verbs ⊆ {r, c}
# an empty map ({}) is a WORM zone with no create-capable principals
Effect inside a WORM zone (any cascade level declares worm:), applied
AFTER the normal cascade ACL and BEFORE the admin escape hatch:
- w / d / a stripped for everyone
- c survives only via the worm: map
- r survives via the normal ACL OR the worm: map (so a document
controller who isn't in the project ACL still gets read+create)
- worm: grants UNION across the cascade — deeper .zddc can name
more controllers
- admins (root / subtree) bypass entirely — handler does the
IsAdmin check before the policy evaluator
defaults.zddc.yaml: archive/<party>/received and archive/<party>/issued
carry `worm: {}` (WORM zone, no controllers — the deployment names
its document controller by adding a deeper .zddc with
`worm: {<principal>: cr}`). The canonical convention is unchanged;
the difference is an operator can now mark any directory WORM, or
rename received/issued, without a code change.
Removed (hardcoded path predicates, superseded by the cascade walk):
zddc.IsWormPath
zddc.WormFolderLevelIndex
zddc.splitPathSegments (only IsWormPath used it)
Kept: zddc.WormMask (generic verb-set primitive), zddc.VerbsRC.
New:
zddc.WormZoneGrant(chain, email, mode) → (verbs, inWormZone)
Walks the chain for worm: declarations; unions the principal's
grants masked to {r, c}.
policy.InternalDecider.Allow: WORM block rewritten to consult
WormZoneGrant instead of IsWormPath/WormFolderLevelIndex.
ValidateFile: worm: keys validated as email-glob (or @role:name);
values validated as verb strings ⊆ {r, c}.
Tests:
- new worm_test.go covers the embedded convention, operator-granted
controller, w/d masking, cross-cascade union.
- special_test.go's TestIsWormPath / TestWormFolderLevelIndex
retired; TestWormMaskStripsWDA kept.
- fileapi_test.go's WORM tests updated: the doc-controller grant is
now `worm: { _doc_controller: cr }` at issued/.zddc, not
`acl.permissions: { _doc_controller: cr }`.
- federal-parity and admin-bypass tests unchanged — the WORM mask
still strips w/d/a and admins still bypass.
All Go tests green.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
zddc-server now issues its own bearer tokens for non-browser callers
(CLI tools, scripts, downstream proxy/cache/mirror instances). No
external IDP, no JWKS rotation. Self-service flow: sign in via the
browser, visit /.tokens, click "Create token," paste the resulting
plaintext into a 0600 file, and pass --bearer-file <path> to whatever
calls back into the server.
Storage is <ZDDC_ROOT>/.zddc.d/tokens/<sha256-hex>, YAML per token
with email/created/expires/description. Filename is the *hash* of the
plaintext, never the plaintext itself — a leak of the tokens
directory exposes hashes, not credentials. Mode 0600 / 0700, atomic
writes via temp+rename. Already shielded from public serving by the
existing dot-prefix guards in dispatch and fs.ListDirectory.
ACLMiddleware now recognises Authorization: Bearer <token>. On valid
token, sets the request email from the token file and falls through
to the existing ACL chain. On any failure (unknown / expired / store
unavailable / Bearer with no validator), returns 401 — no silent
fallback to anonymous, so a misconfigured client fails loudly.
JSON API at /.api/tokens (GET list, POST create, DELETE /<id> revoke)
backs a small inline HTML self-service page at /.tokens. Users can
only see and revoke their own tokens; cross-user revoke returns 404
to avoid leaking ownership.
--no-auth (ZDDC_NO_AUTH=1) skips ACL enforcement entirely on this
instance. On master: anyone reads everything (dev / trusted-LAN /
public-read deployments). On a downstream proxy/cache/mirror: trust
upstream's filtering, don't re-evaluate ACLs locally. Implemented as
a swap to policy.AllowAllDecider; all existing handlers keep calling
AllowFromChain unchanged. Distinct from --insecure, which only
relaxes the no-root-.zddc startup check. WARN-level startup log when
--no-auth is active so accidental enablement is visible.
33 new tests covering token storage, validation/expiry/revocation,
the JSON API end-to-end, the HTML page, and the middleware-Bearer
integration including the case-insensitive prefix and expired-token
paths. Full suite + go vet clean.
Doc updates: zddc/README.md "Authentication" rewritten to cover both
auth paths and the token UI/API; AGENTS.md gains ZDDC_NO_AUTH and a
"Bearer tokens" subsection flagging the dot-prefix-shielding pre-
condition; ARCHITECTURE.md adds "Bearer token issuance" and
"--no-auth" subsections under "Server security model" with the
hash-as-filename rationale and dispatch-shielding regression-
sensitivity called out; CLAUDE.md adds a one-line summary of the new
auth topology so future agents pick it up by default.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Replaces the binary acl.allow/deny model with five permission verbs
(r/w/c/d/a) and first-class roles, and adds an authenticated file API
(PUT/DELETE/POST move/mkdir) so the HTML tools can edit-in-place over
HTTP. Closes the AC-3(7) and AC-6 federal-readiness gaps.
File API (zddc/internal/handler/fileapi.go)
- PUT <new> → action c
- PUT <existing> → action w
- PUT <.zddc> → action a (CanEditZddc strict-ancestor rule)
- DELETE → action d
- POST mkdir → action c (auto-writes creator-owned .zddc when the
parent is Incoming/Working/Staging)
- POST move → action w on src + c on dst, atomic via os.Rename
- Optional If-Match for optimistic concurrency, --max-write-bytes cap,
audit log emits a structured file_write event per operation.
Permission model (zddc/internal/zddc/{acl,file,roles,cascade_mode}.go)
- acl.permissions: { principal → verb-set } map; principals are email
patterns or role names. Empty verb set is an explicit deny.
- roles: { name → members } definitions, available at the level they
declare and all descendants. Closer-to-leaf shadows ancestor.
- Legacy acl.allow/deny still work; they fold into permissions at
parse time (allow → "rwcd", deny → "").
- Cascade walks leaf→root; first level with any matching entry wins;
the union of matching verb sets at that level decides.
- --cascade-mode=strict adds a root→leaf ancestor-deny pre-pass so an
ancestor explicit-deny is absolute (NIST AC-6). Default delegated
preserves the existing commercial behavior.
Special folders (zddc/internal/zddc/special.go)
- Incoming / Working / Staging: mkdir auto-writes a .zddc into the new
subdir granting created_by + that email rwcda directly. Same form
operators write by hand; creator can edit it later to add others.
- Issued / Received: server-enforced WORM split. Cascade grants
inherited from above the WORM folder are masked to r only; grants
placed at-or-below the WORM folder retain r,c. Operators grant
write-once (cr) to the doc controller via an explicit .zddc at the
Issued/Received folder. Admins exempt — only escape hatch.
Browser polyfill (shared/zddc-source.js)
- HttpDirectoryHandle + HttpFileHandle implement the FS Access API
surface (values, getFileHandle, createWritable, removeEntry,
queryPermission/requestPermission) over zddc-server's listing JSON
and file API. Existing tools written against showDirectoryPicker
work unchanged.
- detectServerRoot() returns { handle, status }: tools auto-load on
HTTP, surface a clear "no permission to list" message on 403, and
fall back to the welcome screen on 0.
- classifier renames take the atomic POST move path on HTTP-backed
handles; mdedit and transmittal route reads/writes through the
polyfill so prior FS-API code paths cover both modes.
Tests
- zddc/internal/zddc/{cascade_mode,roles,special,acl}_test.go cover
delegated vs strict, role membership / shadowing / legacy fallback,
WORM split semantics, verb-set parser round-trip.
- zddc/internal/handler/fileapi_test.go now also covers role-based
vendor scenarios, WORM blocking vendor & doc controller writes,
explicit Issued .zddc unlocking the cr drop-box, admin bypass,
auto-ownership on mkdir, and strict-mode lockouts.
Docs
- ARCHITECTURE.md + zddc/README.md document the verb model, role
syntax, special-folder behaviors, cascade-mode flag, and full file
API surface. Federal-readiness gap analysis strikes AC-3(7) and
AC-6.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Ship a second parity-tested Rego policy that flips the cascade's
leaf-allow-overrides-parent-deny rule for NIST AC-6 conformance.
Standard cascade (existing access.rego, mirrors internal Go evaluator):
Bottom-up walk; first explicit match wins; deny-first within a level.
A leaf-level allow CAN override an ancestor's deny. This is the
cascade's intentional delegation property — a project-owner who
re-allows a previously-denied collaborator works as expected.
Federal mode (new access_federal.rego):
Any deny anywhere along the chain is absolute. An allow only matters
if no level (any depth) has denied the same email. Required by
NIST AC-6 default expectations: a central admin's deny at the root
must be unbypassable by a tenant who controls a subtree's .zddc.
Operators run real OPA with this Rego and point ZDDC_OPA_URL at it;
the internal Go evaluator stays on the commercial cascade. The
toggle is "which policy does your OPA evaluate," not a knob inside
zddc-server.
Surfaced via --print-rego flag:
zddc-server --print-rego # standard (default)
zddc-server --print-rego=standard # same
zddc-server --print-rego=federal # AC-6 strict variant
Parity test (federal_parity_test.go) compiles both Regos and asserts:
* They AGREE on every cascade scenario where no ancestor-deny
intersects a leaf-allow (most cases).
* They DISAGREE — by design — on the three scenarios where the
AC-6 rule differs:
- "leaf allows what parent denied" → standard allows, federal denies
- "deep leaf re-allows after middle deny" → same
- "glob deny at root + specific allow at leaf" → same
Cross-checks the divergence flag explicitly so any future change that
accidentally collapses the two policies fails the test.
Closes the AC-6 row of the federal-readiness gap analysis (now marked
"partially complete" in zddc/README.md — the full bullet would be a
built-in --policy-mode=federal toggle that also flips the in-process
Go evaluator).
Production binary unchanged at 13.1 MB (Rego files embedded as bytes;
OPA library remains test-only).
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Phase 2 enhancements to the policy decider, plus listing-level ETags
that benefit every deployment regardless of decider mode.
Reference Rego policy
---------------------
internal/policy/rego/access.rego mirrors InternalDecider's semantics
exactly — bottom-up walk, deny-first within a level, default-deny when
HasAnyFile=true, glob matching with @-boundary semantics (special-cased
bare "*" because OPA's glob.match treats empty delimiters
inconsistently for that pattern).
Embedded into the binary via go:embed; --print-rego dumps it to stdout
so federal customers standing up an external OPA can use it as a
parity-tested baseline:
zddc-server --print-rego > /etc/opa/policies/zddc-access.rego
Parity test runner
------------------
parity_test.go imports the OPA Go module as a TEST-ONLY dependency
(github.com/open-policy-agent/opa@v0.70.0). Every fixture from the
internal Go evaluator's test set runs through both implementations;
any divergence fails CI. The test-only import means production
binaries (built by `go build ./cmd/zddc-server`) stay OPA-free —
release-flag binary size unchanged at ~13 MB.
The parity test caught a real bug on first run: bare "*" patterns
didn't match through OPA's glob.match with empty delimiters. Fixed
in access.rego with a special-case rule. This is exactly the kind of
subtle drift the parity guard exists to catch.
External-mode decision cache
----------------------------
HTTPDecider is now wrapped in a cachingDecider with a default 1s TTL.
Bursty patterns like .archive listings (one OPA round-trip per entry
before, one per (email, decision-input) tuple per TTL window after)
amortize cleanly. Verified: 20 identical /D/ requests produce 1 OPA
hit with cache, 40 hits without (each listing makes 2 ACL queries).
ZDDC_OPA_CACHE_TTL knob (default 1s) lets operators tune. 0 disables.
1s matches the fsnotify watcher debounce window — staleness is
bounded the same way other policy-edit propagation already is.
Internal mode unchanged; the in-process Go evaluator is already
cheaper than a cache lookup would be.
Listing ETags
-------------
GET / (project list) and GET /<dir>/ (directory listing JSON) now
carry content-hash ETag + Cache-Control: private, max-age=0,
must-revalidate. SHA-256 of the rendered JSON, truncated to 16 hex
chars (64 bits — collision risk on a listing of any realistic size
is vanishingly small).
Server-side caching deliberately not added: it would require
mtime-based invalidation, and Azure Files SMB mounts (a common
deployment substrate) don't support fsnotify reliably. The
content-hash ETag delivers the bandwidth savings (304 on identical
fetches) without depending on watcher correctness — the hash is the
actual response, so it can't lie about staleness regardless of
underlying watcher behavior.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Add an internal access-decision boundary that all handlers go through
instead of calling zddc.AllowedWithChain directly. Two implementations
ship:
* InternalDecider — wraps the existing zddc.AllowedWithChain. The
default. No new dependencies, identical semantics to the legacy
code path. ZDDC_OPA_URL=internal (or unset).
* HTTPDecider — POSTs the canonical OPA wire format
(POST /v1/data/zddc/access/allow with {"input": {...}}, response
{"result": true|false}) over HTTP, HTTPS, or a Unix-domain socket.
For federal customers running their own audited Rego policies
alongside zddc-server. ZDDC_OPA_URL=http(s)://… or unix:///….
External-mode failure semantics: unreachable / non-2xx / malformed
response → fail closed (deny) by default with a WARN log. Operators
who prefer availability over correctness flip with ZDDC_OPA_FAIL_OPEN=1.
The decider is constructed once at startup, plumbed through ACLMiddleware
into the request context. Handlers retrieve it via DeciderFromContext;
non-request callers (fs.ListDirectory, EnumerateProjects, enumerateAccess)
take it as an explicit parameter.
zddc.ZddcFile and zddc.ACLRules gain JSON tags so external Rego authors
get idiomatic input shape (acl.allow, admins, …) instead of Go field
names (ACL.Allow, Admins, …).
Test coverage:
* InternalDecider parity tests against zddc.AllowedWithChain (every
documented cascade scenario: empty chain, leaf-allow-wins, leaf-
deny-beats-parent, leaf-allows-what-parent-denies, deepest-match-
wins, etc.)
* HTTPDecider happy-path test (canonical wire format)
* Fail-closed / fail-open / malformed-response tests
Production binary size unchanged (no new deps; HTTP transport is
stdlib net/http). 11 ACL call sites migrated. End-to-end verified
against the worked-example layout in zddc/README.md.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
