This is a load-bearing internal refactor with no user-visible behavior
change. The new internal/crypto/signer package abstracts CA private-key
signing behind a Signer interface (embeds stdlib crypto.Signer + adds
Algorithm()). The local issuer now consumes this interface; the
historical c.caKey crypto.Signer field is renamed c.caSigner signer.Signer.
What landed:
* internal/crypto/signer/ — new stdlib-only package
- Signer interface: crypto.Signer + Algorithm()
- Algorithm enum: RSA-2048, RSA-3072, RSA-4096, ECDSA-P256, ECDSA-P384
- Driver interface: Load / Generate / Name
- FileDriver: production driver, wraps file-on-disk PEM, hooks for
DirHardener + Marshaler so the local package can inject Bundle 9
keystore.ensureKeyDirSecure + keymem.marshalPrivateKeyAndZeroize
- MemoryDriver: in-memory test driver; safe for concurrent use
- parse.go: ParsePrivateKey moved here from local.go (PKCS#1, SEC 1, PKCS#8)
- 91.6% coverage (gate ≥85)
* internal/connector/issuer/local/local.go — refactor
- Rename c.caKey crypto.Signer → c.caSigner signer.Signer
- Rewire 4 signing call sites: leaf cert (line ~613), CRL (~849),
OCSP response (~887), CA bootstrap (~482) — all access the
interface; the bootstrap also switches to interface-level
Public() + Signer
- Wrap freshly-generated and freshly-loaded keys; reject Ed25519
and other unsupported algorithms at load time (was silently
accepted before, would have failed at first sign)
- Delete the duplicated parsePrivateKey helper (single source of
truth now lives in the signer package)
- Update the L-014 threat-model comment block (lines 1-29) with a
forward-reference paragraph: file-on-disk caveats apply only to
FileDriver-backed signers; alternative drivers close that leg
- Coverage 86.7 → 86.5 (above CI floor of 86); the 0.2pp drop is
mechanical from deleting parsePrivateKey, partially recovered by
a new test pinning the Wrap error path
* internal/crypto/signer/equivalence_test.go — Phase 3 safety net
- RSA byte-strict equality for leaf certs / CRLs / OCSP responses
(PKCS#1 v1.5 is deterministic)
- ECDSA TBS-strict equality (signature differs because of random k)
- Both signatures independently validate against the CA
- Negative sentinel proves the equivalence checker isn't trivially-
passing
* docs/architecture.md — new 'CA Signing Abstraction' section under
Security Model, with ASCII diagram of FileDriver / MemoryDriver /
future PKCS11Driver / future CloudKMSDriver
* Test file mechanical edits (only):
- bundle9_coverage_test.go: parsePrivateKey → signer.ParsePrivateKey
(function moved, not behavior changed)
- local_test.go: append one targeted test
(TestSubCA_LoadCAFromDisk_RejectsUnsupportedKeyAlgorithm) that
pins the new Wrap error path I introduced — recovers coverage
cost of the deletion above
What did NOT change (verified empty diffs):
* api/openapi.yaml
* migrations/
* internal/connector/issuer/interface.go
* go.mod / go.sum (no new dependencies; stdlib only)
This refactor is the prerequisite for three downstream items:
- PKCS#11/HSM driver (V3-Pro)
- CRL/OCSP responder (V2)
- SSH CA lifecycle (V2)
Each of those adds a new signing call site. Doing the abstraction now
costs once; deferring would cost three times.
loadCAFromDisk now validates the upstream sub-CA certificate's NotBefore
and NotAfter fields before accepting it, returning a fail-closed error
at server startup instead of silently loading an out-of-window CA.
Before this fix, loadCAFromDisk checked BasicConstraints.IsCA and
KeyUsage=CertSign but not the validity window. An expired enterprise
sub-CA (e.g. an ADCS subordinate whose rollover slipped) would load
without warning and the scheduler would mint child certs that every
RFC 5280 path validator rejects — outages show up at relying parties,
not at certctl, and only after thresholds trip.
CWE-672 (Operation on a Resource after Expiration or Release); secondary
CWE-295 (Improper Certificate Validation). Error strings include the CA
subject CommonName and both RFC3339 timestamps so the log line is
actionable in a 3am incident.
Tests: TestSubCAMode gains three subtests exercising the new gate —
SubCA_ExpiredCert_IsRejected (CA expired 1h ago → error mentions
'expired' and the CN), SubCA_NotYetValid_IsRejected (CA valid +1h →
error mentions 'not yet valid' and the CN), and SubCA_BarelyValid_IsAccepted
(CA valid [now-1m, now+1h] → issuance succeeds, proving no
over-rejection). Adds generateTestSubCAWithValidity helper; the
original generateTestSubCA wrapper preserves the [now, now+5y] default
for existing tests.
Package coverage: 67.7% -> 68.3%.
Verification: go build, go vet, go test -race, go test -cover all
green locally; golangci-lint v2.11.4 clean; govulncheck clean. All CI
coverage floors met with margin (service 67.6/55, handler 78.6/60,
domain 92.7/40, middleware 80.0/30, crypto 86.7/85).
Parent: 76d383b (M-8 per-ciphertext salt).
Closes: audit finding M-5 in certctl-audit-report.md.
Enforce certificate profile crypto constraints across all 5 issuance paths
(renewal, agent CSR, EST, SCEP). ValidateCSRAgainstProfile() rejects CSRs
with key algorithm/size that don't match profile rules. MaxTTL enforcement
caps certificate validity per issuer connector (Local CA, Vault, step-ca
enforce directly; ACME/DigiCert/Sectigo pass through). Key algorithm and
size are now persisted in certificate_versions for audit compliance.
16 new tests (12 service-layer + 4 Local CA connector). Removes hardcoded
version number from GUI sidebar. Documentation updated across architecture,
features, connectors, and README.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Backend:
- Embedded OCSP responder: GET /api/v1/ocsp/{issuer_id}/{serial} returns
signed OCSP responses (good/revoked/unknown) using CA key
- DER-encoded X.509 CRL: GET /api/v1/crl/{issuer_id} returns proper DER CRL
signed by issuing CA with 24h validity window
- Short-lived cert exemption: certs with profile TTL < 1 hour skip CRL/OCSP
(expiry is sufficient revocation for ephemeral workloads)
- Extended issuer connector interface with GenerateCRL and SignOCSPResponse
- Local CA implements full CRL/OCSP signing; ACME and step-ca return
appropriate "use native endpoint" errors
- IssuerConnectorAdapter bridges new methods between layers
Frontend:
- Revoke button on certificate detail page with RFC 5280 reason modal
- Revocation banner with reason display and timestamp
- Revocation status indicators in lifecycle section
- "Revoked" filter option in certificates list
- API client: revokeCertificate() function and Certificate type extensions
Tests: ~31 new tests across connector, service, handler, and adapter layers
Docs: milestones renumbered (M13-M14, M16-M18), M15b marked complete
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Sub-CA mode: Local CA loads CA cert+key from disk (CERTCTL_CA_CERT_PATH +
CERTCTL_CA_KEY_PATH) to operate as subordinate CA under enterprise root
(e.g., ADCS). Supports RSA, ECDSA, PKCS#8 keys. Validates IsCA and
KeyUsageCertSign. Falls back to self-signed when paths unset.
DNS-01 challenges: Pluggable DNSSolver interface with script-based hook
implementation. User-provided scripts create/cleanup _acme-challenge TXT
records for any DNS provider. Configurable propagation wait. Enables
wildcard certs and non-HTTP-accessible hosts.
step-ca connector: Smallstep private CA via native /sign API with JWK
provisioner auth. Issuance, renewal, revocation. Registered as iss-stepca.
23 new tests across 3 files. CI test path widened to ./internal/connector/issuer/...
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Shankar