Phase-10 live-IdP smoke (Keycloak 26.x via testcontainers-go) revealed
the IdP-bind alg-downgrade check was too strict for real-world IdPs.
6 of the integration tests in internal/auth/oidc/integration_keycloak*_test.go
were failing with:
oidc: IdP advertises weak signing algorithms (HS*/none);
refusing to use as defense against downgrade attacks: HS256
Keycloak 26.x (and several other real-world IdPs — Auth0 when HS-mode is
enabled, some Authentik configs) advertise EVERY alg they're capable of
in the discovery doc's id_token_signing_alg_values_supported field, even
when the realm only signs with RS256 in practice. Pre-fix the IdP-bind
check refused on ANY HS* or 'none' advertisement → no real Keycloak deploy
could ever bind a provider row, hence the integration-test failures.
The strict-deny check was defense-in-depth on top of the load-bearing
per-token alg-pin at sig-verify time (isDisallowedAlg, service.go L1177):
that check rejects every ID token whose JWS header carries an alg outside
DefaultAllowedAlgs, regardless of what the discovery doc advertises.
A forged HS256 token signed with the IdP's RS256 pubkey as HMAC secret
is rejected at sig-verify time → the actual algorithm-confusion attack
is closed by the per-token pin, NOT by the discovery-doc check.
Fix: relax the IdP-bind check to refuse only when the intersection of
advertised vs DefaultAllowedAlgs is EMPTY (the pathological all-weak-alg
IdP case). Keycloak (RS256 + HS256 advertised) now binds successfully;
an HS-only IdP still fails closed.
Changes:
- internal/auth/oidc/service.go: rewrite the alg-check loop at L1067 in
getOrLoad / RefreshKeys to compute the intersection set; refuse only
when no acceptable alg is advertised. ErrIdPDowngradeAdvertised
docstring updated to reflect new contract. DefaultAllowedAlgs
docstring + the package-level design-comment block at L40-72 updated
with v2.1.0-relaxed semantics callouts.
- internal/auth/oidc/test_discovery.go: TestDiscovery dry-run validator
rewritten to surface HS*/none alongside RS* as an informational note
('note: IdP advertises weak algorithms %v alongside acceptable ones')
rather than a hard-fail error. HS-only / none-only still hard-fails.
- internal/auth/oidc/service_test.go: TestService_IdPDowngradeDefense_*
tests updated. Renamed:
- RejectsHSAdvertised → RS256PlusHS256_BindsSuccessfully (positive)
- RejectsNoneAdvertised → RejectsHSOnlyAdvertised (intersection-empty)
- RefreshKeys_CatchesPostLoadDowngrade rotated to HS-only post-load
- internal/auth/oidc/coverage_fill_test.go: TestTestDiscovery_AlgDowngradeDetected
split into _HS256AlongsideRS256_BindsWithNote (positive, asserts note
but no hard-fail) + _HSOnly_StillTrips_HardFail (intersection-empty).
- docs/operator/auth-threat-model.md: OIDC token-validation alg-allow-list
section rewritten to call out the load-bearing-defense hierarchy
(per-token pin first, IdP-bind check defense-in-depth) and document
the v2.1.0 relaxation rationale.
- CHANGELOG.md: ### Security entry under Unreleased.
Verify: go test ./internal/auth/oidc/ -short PASS; gofmt clean; go vet
clean. The Keycloak integration tests should now pass when the operator
re-runs 'make keycloak-integration-test'.
certctl Documentation
Last reviewed: 2026-05-05
The full docs index, organized by audience. Pick the section that matches what you need to do; each link below opens a focused doc rather than a wall of text.
For the elevator pitch and quickstart commands, see the repo README.md at the root. For the marketing site, see certctl.io.
Getting Started
You're new to certctl, just cloned the repo, or want to understand what it does before installing.
| Doc | What it covers |
|---|---|
| Concepts | TLS certificates explained for beginners — CAs, ACME, EST, private keys, the full glossary |
| Quickstart | Five-minute setup with Docker Compose, dashboard tour, API tour |
| Examples | Five turnkey scenarios — ACME+NGINX, wildcard DNS-01, private CA+Traefik, step-ca+HAProxy, multi-issuer |
| Advanced demo | End-to-end certificate lifecycle with technical depth at each step |
| Why certctl | Positioning vs ACME clients, agent-based SaaS, enterprise platforms; when to look elsewhere |
Reference
You're operating certctl in production or building integrations and need authoritative technical detail.
| Doc | What it covers |
|---|---|
| Architecture | System design, data flow, security model, deployment topologies |
| Profiles | CertificateProfile policy object — issuer wiring, EKUs, RequiresApproval gate (Phase 9 closure) |
| API | OpenAPI 3.1 spec, integration patterns, client SDK generation |
| CLI | certctl-cli command reference and CI/CD integration patterns |
| Configuration | CERTCTL_* environment variable reference (scheduler, rate limits, deploy verify, audit, agent) |
| MCP server | Model Context Protocol integration for AI assistants |
| Release verification | Cosign / SLSA / SBOM verification procedure |
| Intermediate CA hierarchy | Multi-level CA tree management — RFC 5280 §3.2/§4.2.1.9/§4.2.1.10 enforcement |
| Auth standards implemented | RFC + CWE evidence for the Auth Bundle 1 + 2 surface (NOT a compliance-mapping doc) |
| Deployment model | Atomic write, post-deploy verify, rollback semantics across all targets |
| Vendor matrix | Tested vendor versions per target connector |
Connectors
The connector index is the canonical catalog (interfaces, registry, scanners, plus an inline reference per built-in). Per-connector deep-dive siblings cover operator-grade material — vendor edges, troubleshooting, rotation playbooks, when-to-use vs alternatives.
Issuers (13 deep-dives): ACME · ADCS · AWS ACM Private CA · DigiCert · EJBCA / Keyfactor · Entrust · GlobalSign Atlas HVCA · Google CAS · Local CA · OpenSSL / Custom CA · Sectigo SCM · step-ca / Smallstep · Vault PKI
Targets (15 deep-dives): Apache · AWS Certificate Manager · Azure Key Vault · Caddy · Envoy · F5 BIG-IP · HAProxy · IIS · Java Keystore · Kubernetes Secrets · NGINX · Postfix / Dovecot · SSH (agentless) · Traefik · Windows Certificate Store
Protocols
| Doc | What it covers |
|---|---|
| ACME server | Run certctl as an RFC 8555 + RFC 9773 ARI ACME server |
| ACME server threat model | Security posture for the ACME server endpoint |
| SCEP server | RFC 8894 native SCEP server — RA cert config, multi-profile dispatch, must-staple, mTLS sibling route |
| SCEP for Microsoft Intune | Intune-specific deployment guide — NDES replacement playbook |
| EST server | RFC 7030 EST server — 802.1X / Wi-Fi enrollment, IoT bootstrap, channel binding |
| CRL & OCSP | RFC 5280 CRL + RFC 6960 OCSP responder for relying parties |
| Async CA polling | Bounded polling for async-CA issuer connectors |
Operator
You're running certctl in production and need operational guidance.
| Doc | What it covers |
|---|---|
| Security posture | Auth, rate limits, encryption at rest, key rotation, RBAC primitive (Bundle 1), bootstrap |
| RBAC operator reference | Roles, permissions, scopes, scope-down + bootstrap flow (Bundle 1) |
| Auth threat model | API-key compromise, role-grant abuse, bootstrap-token leak, audit-mutation, compliance mapping (Bundle 1) |
| OIDC / SSO runbooks | Per-IdP setup guides — Keycloak, Authentik, Okta, Auth0, Entra ID, Google Workspace (Bundle 2) |
| Control plane TLS | Self-signed bootstrap, operator-supplied Secret, cert-manager Certificate CR |
| Database TLS | PostgreSQL transport encryption |
| Approval workflow | Two-person integrity gate for high-stakes issuance + Phase 9 profile-edit closure |
| Helm deployment | Kubernetes installation via the bundled chart |
| Performance baselines | Operator-runnable benchmarks for regression spot checks |
| Auth benchmarks | Session + OIDC validation p99 targets and measured baselines (Bundle 2 Phase 14) |
| Legacy clients (TLS 1.2) | Reverse-proxy runbook for embedded EST/SCEP clients on TLS 1.2 |
Runbooks
| Runbook | When |
|---|---|
| Cloud targets | AWS ACM + Azure Key Vault deployment, debugging, rollback |
| Expiry alerts | Per-policy multi-channel routing matrix, severity tiers |
| Disaster recovery | CRL cache, OCSP responder cert, CA private-key rotation, Postgres restore |
Migration
You're moving from another cert-management tool to certctl, or running both in parallel.
| From | Doc |
|---|---|
| Certbot | migration/from-certbot.md |
| acme.sh | migration/from-acmesh.md |
| cert-manager (coexistence, not replacement) | migration/cert-manager-coexistence.md |
| Caddy ACME (point Caddy at certctl) | migration/acme-from-caddy.md |
| cert-manager ACME (point cert-manager at certctl) | migration/acme-from-cert-manager.md |
| Traefik ACME (point Traefik at certctl) | migration/acme-from-traefik.md |
| API keys → RBAC (v2.0.x → v2.1.0) | migration/api-keys-to-rbac.md — AUDIT YOUR API KEYS post-upgrade |
| Enable OIDC SSO on a Bundle-1-merged deployment | migration/oidc-enable.md — step-by-step Bundle 2 OIDC onboarding |
Contributor
You're contributing to certctl, running tests locally, or trying to understand the CI pipeline.
| Doc | What it covers |
|---|---|
| Testing strategy | What we test and why; per-PR fast gates vs daily deep-scan |
| Test environment | Local environment with real CAs (Pebble, step-ca, etc.) |
| QA prerequisites | Before running QA: stack boot, demo data baseline, env vars |
| QA test suite | qa_test.go reference for release QA |
| GUI QA checklist | Manual GUI verification pass for release |
| Release sign-off | Release-day checklist — code state, automated gates, manual QA, artefact verification |
| CI pipeline | CI shape, regression guards, adding new checks |
Archive
Historical docs preserved for reference. Most operators don't need these.
| Doc | Why archived |
|---|---|
| Upgrade to TLS (v2.2) | Pre-v2.2 HTTPS-everywhere upgrade procedure |
| Upgrade past v2 JWT removal | G-1 milestone JWT auth removal procedure |
Reading order by role
First-time operator: Concepts → Quickstart → Examples. About 90 minutes end to end.
Production operator: Architecture → Security posture → Control plane TLS → Disaster recovery runbook. About 4 hours end to end.
PKI engineer: ACME server → SCEP server → EST server → Intermediate CA hierarchy. About 6 hours end to end.
Contributor: Architecture → Testing strategy → Test environment → CI pipeline. About 3 hours end to end.