Sprint 1 unified-master-audit closure. Two OIDC discovery call sites
passed the bare request context to gooidc.NewProvider:
- internal/auth/oidc/test_discovery.go:65 (dry-run validator)
- internal/auth/oidc/service.go:1066 (runtime cache load)
gooidc.NewProvider derives its HTTP client from the context via
oidc.ClientContext; with no override it falls through to
http.DefaultClient — no SSRF guard. An admin with auth.oidc.create
could induce server-side HTTPS egress to loopback (127.0.0.1, ::1),
RFC 1918, link-local (169.254.169.254 — cloud-instance metadata),
and IPv6 link-local (fe80::/10). The companion JWKS reachability
probe was already routed through SafeHTTPDialContext via the
Bundle 5 R6 closure; the discovery + claims path bypassed that.
Fix:
- New internal/auth/oidc/safehttp.go: oidcDiscoveryClient (Transport
DialContext = validation.SafeHTTPDialContext) + SafeOIDCContext
helper. Both call sites now wrap ctx through SafeOIDCContext
before NewProvider runs.
- Defense-in-depth: OIDCProvider.Validate calls
validation.ValidateSafeURL on the IssuerURL after the existing
https/parse checks, refusing reserved-address issuers at
provider-creation time.
- TestDiscovery surfaces the SSRF policy error via the result's
Errors slice up-front (early-fail UX rail) before invoking
NewProvider.
Test seams:
- setup_test.go swaps oidcDiscoveryClient + validateIssuerSSRF
for httptest loopback compatibility, mirroring the existing
jwksProbeClient pattern.
Regression coverage:
- internal/auth/oidc/domain/types_test.go: 5-case table pinning
loopback v4/v6, cloud metadata, link-local v4/v6 rejection.
- internal/auth/oidc/coverage_fill_test.go: same 5 cases against
Service.TestDiscovery via temporarily restoring the production
gate.
Closes SEC-001.
CI break diagnosed from go-build-and-test on 47da13e+596e675:
TestTestDiscovery_HappyPath_AgainstMockIdP + TestTestDiscovery_JWKSFetchFails
fail with "refusing to dial reserved address 127.0.0.1" because my
Bundle 5 R6 closure wrapped jwksReachable in
validation.SafeHTTPDialContext — which is exactly what the production
guard is supposed to refuse for httptest.NewServer's 127.0.0.1 bind.
Same shape as the Slack/Teams test-seam fix in 596e675: factor the
http.Client construction into a package-level var (`jwksProbeClient`),
default to the SSRF-safe transport in production, override to
http.DefaultTransport in test-only `setup_test.go::init()`. Production
code never reassigns the var. The audit R6 closure stands — the
production jwksReachable still uses validation.SafeHTTPDialContext.
Verification (sandbox, Go 1.25.10):
go test -short -count=1
-run 'TestTestDiscovery_HappyPath|TestTestDiscovery_JWKSFetchFails'
./internal/auth/oidc # PASS (1.1s)
go test -short -count=1 ./internal/auth/oidc # PASS (21.8s)
gofmt -l # clean
go vet ./internal/auth/oidc # clean
shankar0123