Registry-wide hardening of the `mcp-name:` ownership-token match, plus
the cargo follow-up fixes from the #1330 review — consolidated here per
maintainer request. Rebased onto current `main` (the merged #1330 cargo
commit drops out), so the diff is just the net-new work.
### Changes
- **PyPI/NuGet: boundary-anchored token match.** Replace
`strings.Contains(readme, "mcp-name: "+name)` with the shared
`containsMCPNameToken`, so a README declaring a longer name
(`…/widget-pro`) no longer satisfies an ownership claim for a shorter
prefix (`…/widget`). (Cargo already got this in #1330; NPM is unaffected
— it compares an exact metadata field.)
- **Matcher: treat the HTML comment close as a boundary.** `<!--
mcp-name: NAME-->` / `<!--mcp-name: NAME-->` (any spacing) validate
again — the documented hidden-comment form for PyPI/NuGet — while a
genuine longer name (`…/widget--pro`) still does not.
- **Cargo hardening (review of #1330):** pin scheme+port (not just host)
on the README fetch and redirects; a rate-limited/failed crate-version
existence probe now reports *transient* instead of "not found"; a 403
with the crate present no longer flatly asserts "no README".
- **Docs:** note the token must be followed by a boundary.
### ⚠️ Behavior change for PyPI/NuGet — read before merging
The match is **strictly stricter** (verified by fuzz, 2.3M execs: it can
only flip pass→fail, never fail→pass). After the comment-close fix, the
**only** forms that newly fail are unusual *inline* ones: the token
ending a sentence (`…/my-mcp.`) or glued to a trailing `/`. The
documented forms (own line, in `<!-- … -->`) are unaffected.
**Correcting an earlier claim:** this re-validates on **edits too**, not
just new versions — `edit.go → UpdateServer → ValidateUpdateRequest →
validateRegistryOwnership` runs the token check on any edit of a live
server (only delete-transitions skip it). So an existing PyPI/NuGet
server whose README uses one of the breaking inline forms would fail on
its next publish *or* edit. Given the v0.1 API-freeze posture, this
should land as a deliberate, noted change.
### Testing
`go build`, `vet`, `gofmt`, `golangci-lint` (prod files),
`check-schema`, `validate-examples` all clean. Hermetic + **live**
PyPI/NuGet/cargo suite passes. New: `TestCargoURLAllowed`, a
combined-fixture probe-429→transient case, comment-form matcher cases,
and `FuzzContainsMCPNameToken` (the strictly-stricter property, 2.3M
execs).
🤖 Generated with [Claude Code](https://claude.com/claude-code)
---------
Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Follow-up to #1207, addressing items from the cargo validator review.
**Scoped to cargo + shared helpers — no behavior change for existing
npm/pypi/nuget/oci/mcpb publishers.** Safe to merge and promote.
### Changes
**SSRF hardening of the two-call README retrieval**
- Pin the step-2 README URL to an allowed host (`static.crates.io` in
prod; the base host under test) *before* fetching, so a metadata
response can't steer the validator at an internal/attacker host.
- `CheckRedirect` policy pins every redirect hop to the same allowlist
(the initial URL being pinned isn't enough if an upstream 3xx is
followed).
- Cap the README body with `io.LimitReader` (5 MiB).
> Not publisher-exploitable today (the URL comes from crates.io), so
this is defense-in-depth — but it makes the "host is pinned" guarantee
hold in code rather than rely on crates.io's behavior.
**Clearer status handling** (previously any non-5xx/non-200 collapsed to
"not found")
- **429** → reported as transient/retryable, at both the metadata and
README steps.
- **403** → disambiguated via the crate-version endpoint:
genuinely-missing stays "not found"; *exists-but-no-README* gets an
actionable "add a README with `mcp-name` and republish" message (mirrors
the NuGet validator). This continues the 5xx-vs-403 diagnostic split
@P4ST4S started in the #1207 review — thanks!
**Shared `containsMCPNameToken` helper**
Boundary-anchored ownership-token match (prevents prefix confusion, e.g.
a README declaring `io.github.acme/widget-pro` satisfying a claim for
`io.github.acme/widget`), used here **by the cargo validator only**.
Adopting it in PyPI/NuGet is a separate follow-up because it's a
behavior change for those already-live registries.
**Tests & docs**
Hermetic positive `ServerNameFormats`; combined fixture gains a
version-existence endpoint + cases for 403-missing vs 403-no-README,
429, and prefix-confusion rejection; new foreign-README-host (SSRF)
test; internal test for the helper. Docs: list `crates.io` in the
registry-requirements list + the `Package` model doc.
### Testing
`go build`, `go vet`, full `./internal/validators/...` suite (incl. live
cargo positive), `make check-schema`, `validate-examples` all pass. No
new `golangci-lint` findings.
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Radoslav Dimitrov