nebula-mesh: POST /api/v1/hosts/{id}/mobile-bundle response lacks Cache-Control: no-store

Summary

`internal/api/mobile_bundle.go:62-66` sets only `Content-Type: application/yaml`. The Web-UI sibling at `internal/web/handlers.go:1316-1321` sets `Cache-Control: no-store`, `Pragma: no-cache`, `Expires: 0`, `X-Content-Type-Options: nosniff` — and has a test asserting it. The API path was missed.

## Affected All released versions up to v0.3.0.

## Threat model The endpoint returns a freshly minted X25519 private key inline. Without `no-store`, any intermediary proxy or CDN that caches `200 OK` YAML responses retains the private key for its cache TTL. Same applies to browser disk cache for direct API hits. Combined with the cross-tenant authz advisory (critical), even a corrected authz layer would still leak via cache after fix.

## Suggested fix Copy the four headers from the Web sibling:

```go w.Header().Set("Content-Type", "application/yaml; charset=utf-8") w.Header().Set("Cache-Control", "no-store") w.Header().Set("Pragma", "no-cache") w.Header().Set("Expires", "0") w.Header().Set("X-Content-Type-Options", "nosniff") ```

Mirrors `internal/web/handlers.go:1316-1321`. Add a parallel test to the existing web-side coverage.

## Suggested patch

Verified locally: `go vet`, `go test -race -count=1 ./...`, `golangci-lint v2.12` all clean.

```diff diff --git a/internal/api/mobile_bundle.go b/internal/api/mobile_bundle.go index fc09da0..73152eb 100644 --- a/internal/api/mobile_bundle.go +++ b/internal/api/mobile_bundle.go @@ -58,8 +58,15 @@ func (s *Server) handleMobileBundle(w http.ResponseWriter, r *http.Request) { return }

- // Return YAML bundle with proper content-type + // Return YAML bundle with proper content-type. The bundle inlines a + // freshly-minted X25519 private key, so suppress every layer of cache + // between server and operator (intermediate proxies/CDNs, browser disk + // cache). Mirrors the Web-UI sibling at internal/web/handlers.go. w.Header().Set("Content-Type", "application/yaml; charset=utf-8") + w.Header().Set("Cache-Control", "no-store") + w.Header().Set("Pragma", "no-cache") + w.Header().Set("Expires", "0") + w.Header().Set("X-Content-Type-Options", "nosniff") w.WriteHeader(http.StatusOK) if _, err := w.Write(bundle); err != nil { s.logger.Error("write mobile bundle response", "error", err) diff --git a/internal/api/mobile_bundle_test.go b/internal/api/mobile_bundle_test.go index dcb8cd9..da08b01 100644 --- a/internal/api/mobile_bundle_test.go +++ b/internal/api/mobile_bundle_test.go @@ -52,6 +52,19 @@ func TestHandleMobileBundle_Success(t *testing.T) { t.Errorf("Content-Type = %q, want 'application/yaml; charset=utf-8'", ct) }

+ // Bundle inlines a private key — every cache between server and operator + // must drop the response. Mirrors the Web-UI sibling's headers. + for header, want := range map[string]string{ + "Cache-Control": "no-store", + "Pragma": "no-cache", + "Expires": "0", + "X-Content-Type-Options": "nosniff", + } { + if got := w.Header().Get(header); got != want { + t.Errorf("%s = %q, want %q", header, got, want) + } + } + // Verify body is valid YAML with expected keys var yamlData map[string]interface{} if err := yaml.Unmarshal(w.Body.Bytes(), &yamlData); err != nil { ```