a7569a7 added credential-less pulls of public images. Three things about it
were wrong, all of them in how the appview handled the decision that belongs
to the hold.
**Scope handling was all-or-nothing.** IsPullOnlyScope required every
requested action to already be "pull", but clients routinely ask for more
than the operation needs — pull,push is common for a plain read, and some
ask for pull,push,delete up front. Those were rejected and challenged,
leaving a credential-less client no way to pull even a public image, which
is the entire feature. NarrowToPullOnly drops the write actions and issues a
token carrying "pull" and nothing else. Granting a subset is what the
distribution token spec expects. The allowlist property is preserved: "pull"
is the only action that survives, and "*" is deliberately not expanded into
it, since a wildcard request is not evidence the caller wants a read.
**The appview-side read gate was inert.** checkReadAccess passed p.ctx.DID,
the DID of the repository *owner*, not the requester. Any non-empty DID
satisfies a private hold's check, and the owner's is never empty, so it asked
"may the owner read their own hold", answered yes, and admitted everyone.
Worse, CheckReadAccessWithCaptain admitted any authenticated DID to a private
hold at all, on an explicitly-MVP assumption that holding a DID was close
enough to being a sailor. Every doc says otherwise (docs/hold.md:109 "Crew
with blob:read", CLAUDE.md:140, docs/BYOS.md:280) and so does the hold
(ValidateBlobReadAccess: owner, or crew carrying blob:read/blob:write). It
now takes isCrew and requires owner-or-crew, and callers only pay for the
crew lookup when it can change the answer — a public hold or an anonymous
caller is decided by the captain record alone. Nothing here loosens access;
it brings the local gate into agreement with the authority.
**Denials could not reach the client.** distribution's blobHandler.GetBlob
maps everything except ErrBlobUnknown to ErrorCodeUnknown, so a 401 raised
in the blob store left as a 500 — misreporting an auth failure as a server
fault, and giving BearerChallenge no 401 to attach WWW-Authenticate to, so
Docker was told "server error" instead of being prompted for credentials.
Clients that retry 5xx looped: 4.1s per case in the matrix, now 0.01s. The
check moves to Repository(), where an errcode.Error is passed through
verbatim by the registry app — the same mechanism a7569a7 used for
NAME_UNKNOWN. It fails open on a lookup error, since the hold is the
authority and a transient failure should not break public pulls.
Removes auth.allow_anonymous_pull. It could only ever withhold — captain.Public
is what grants — so it was a second flag for a decision the hold already owns,
and gating it appview-side was never the intent. Layer bytes 307 straight to
S3, so the appview is not even in the path whose cost might have justified an
operator-side lever.
Tests: TestAuthMatrix only ever ran against a public hold, and its pull cases
never fetched a layer — crane.Pull is lazy and img.Digest() needs only the
manifest, which ATCR serves from the user's PDS where it is world-readable, so
no pull row in the matrix touched blob authorization at all. Pulls now
materialize layer bytes, and testharness.WithPrivateHold plus
TestAuthMatrixPrivateHold cover public:false + allow_all_crew:true — the
production shape, where anyone with an account pulls and pushes and anonymous
gets nothing.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Credential-less pulls of public images. /auth/token issues a pull-only
token with an empty subject when no Basic auth is present; the
destination hold still enforces captain.Public, and push or delete always
challenges.
- token.IsPullOnlyScope and AuthMethodAnonymous;
Handler.issueAnonymousToken skips the authorizer gate and the
service-auth pre-mint, since there is no identity to reconcile and no
AppView-to-hold service token to bind. The token is still stamped
with the resolved registry domain, so anonymous pull works on
secondary front doors whose access controller demands their own
audience.
- auth.allow_anonymous_pull (default true) turns it fully off, restoring
the previous always-challenge behavior. Mirrored into the deploy
template, since the default means existing deploys pick this up.
- RegistryContext.Anonymous is plumbed from the middleware.
- ProxyBlobStore sends no Authorization header when the service token is
empty, and returns 401 rather than 403 for anonymous denials so Docker
prompts for credentials, including when a stale captain cache lets the
request through and the hold says private.
- BearerChallenge wraps the /v2/ subtree so a 401 raised deep in the
stack via errcode.ServeJSON still carries WWW-Authenticate.
Distribution's own scoped challenges are left alone.
IsPullOnlyScope allowlists the pull action instead of denylisting push and
delete. Distribution's actionSet.contains treats "*" as *every* action, so
a scope of `repository:victim/img:*` names neither denied string and would
have handed an unauthenticated caller a token valid for push and delete on
someone else's repository — clearing the authgate entirely, since anonymous
tokens deliberately skip it. Writes would still have failed further down
(no PDS credential), but the gate itself was bypassable. Now every
requested action must be exactly "pull". Covered by new claims tests.
Unresolvable identities return NAME_UNKNOWN instead of a bare error that
distribution renders as 500. This path was previously unreachable without
credentials; anonymous pull opens it to the internet, and a 5xx on
arbitrary input both misreports a bad request as a server fault and sends
clients that retry 5xx into a retry loop. That loop was real: in the auth
matrix, regclient spent 83s on a single case before this fix, and the
suite now runs in 5s.
Stat preserves an authorization verdict from getPresignedURL rather than
flattening it to ErrBlobUnknown. Distribution calls Stat before ServeBlob
on GET and HEAD, so without this an anonymous pull from a private hold
answered 404 and BearerChallenge had no 401 to annotate — the 401 path
above could never actually reach a client.
The auth matrix is updated to match: anonymous pull of the seeded public
repo now succeeds, anonymous push is denied against a real identity's
namespace (rather than an unresolvable one, which was testing name
resolution rather than authorization), and a new case pins the
NAME_UNKNOWN behavior for an unknown identity.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
DELETE /v2/<name>/manifests/<ref> answered UNSUPPORTED before ever
reaching the ATProto-backed stores: distribution v3.1.1's DeleteManifest
handler short-circuits unless app.deleteEnabled is set, which comes from
storage.delete.enabled. Set it (mirrored in the test harness). The
companion storage.EnableDelete option it appends only affects
distribution's built-in store, which RoutingRepository replaces, so it is
a no-op for us.
With the route reachable, make the stores do the right thing:
- ManifestStore.Delete purges the hold's per-layer, scan and image
config records on a detached context, since the DELETE handler
returns immediately and cancels the request context.
- TagStore.Untag resolves the digest before deleting the tag record,
then deletes the manifest if that was its last tag and it is not a
manifest list child, matching the web UI's delete-tag behavior so
deleting an only-tagged image doesn't orphan the manifest.
- cleanupUntaggedManifest becomes package-level over *RegistryContext
so both stores share one implementation.
- purgeOnHold moves out of handlers into pkg/appview/holdpurge so the
storage layer can call it: handlers already depends on storage via
middleware, so storage to handlers would be an import cycle.
- ProxyBlobStore.Delete returns distribution.ErrUnsupported, so the
always-registered blob DELETE route gives a clean OCI UNSUPPORTED
error instead of a generic 500. Layer bytes are reclaimed by the
hold's refcounted GC.
The cascade's still-tagged re-check pages through the tag records rather
than reading a single capped page. Tags for all of a user's repositories
share one collection, so one page is a per-account budget: past ~100 tags
a live tag fell off the end and the manifest was deleted while still
referenced. Incomplete enumeration now skips the delete, since an
orphaned manifest is recoverable and a deleted live one is not.
This also makes the over-quota delete grant added in 6e426dc load-bearing:
it hands out pull,delete tokens, which could not do anything while
distribution rejected every DELETE.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Evan JarrettandClaude Opus 5