diff --git a/CHANGELOG.md b/CHANGELOG.md index cead220..766925b 100644 --- a/CHANGELOG.md +++ b/CHANGELOG.md @@ -4,6 +4,32 @@ All notable changes to certctl are documented in this file. Dates use ISO 8601. ## [unreleased] — 2026-04-25 +### H-1: Security hardening trio — closed end-to-end + +> Three 2026-04-24 audit findings (all P2) that together complete the HTTPS-Everywhere security baseline. The audit flagged: (1) the unauth surface (EST RFC 7030, SCEP, PKI CRL/OCSP, /health, /ready) accepted arbitrary-size request bodies because the `noAuthHandler` middleware chain was missing the `bodyLimitMiddleware` that the authed `apiHandler` chain has; (2) zero security headers (CSP, HSTS, X-Frame-Options, X-Content-Type-Options, Referrer-Policy) were emitted on any response — enabling clickjacking, MIME-sniffing, and untrusted-origin resource loads against the dashboard and API; (3) `CERTCTL_CONFIG_ENCRYPTION_KEY` was accepted with any non-empty value, including a single character — PBKDF2-SHA256 with 100k rounds does not compensate for low-entropy passphrases at scale (CWE-916 / CWE-329). + +### Breaking Changes + +**Operators with low-entropy `CERTCTL_CONFIG_ENCRYPTION_KEY` will fail to start after upgrade.** Pre-H-1 the field accepted any non-empty string. Post-H-1 it requires ≥32 bytes (e.g. `openssl rand -base64 32`). The startup error names the offending env var, the actual length, the required minimum, and the canonical generation command. Empty (`""`) remains accepted — the existing fail-closed sentinel `crypto.ErrEncryptionKeyRequired` triggers downstream when an empty key tries to encrypt or decrypt. Operators using a short passphrase must rotate before the upgrade. + +### Added + +- **`internal/api/middleware/securityheaders.go`** (new) — `SecurityHeaders` middleware applies HSTS, X-Frame-Options, X-Content-Type-Options, Referrer-Policy, and a conservative Content-Security-Policy on every response. Defaults via `SecurityHeadersDefaults()` are: `Strict-Transport-Security: max-age=31536000; includeSubDomains`, `X-Frame-Options: DENY`, `X-Content-Type-Options: nosniff`, `Referrer-Policy: no-referrer-when-downgrade`, and `Content-Security-Policy: default-src 'self'; img-src 'self' data:; style-src 'self' 'unsafe-inline'; script-src 'self'; connect-src 'self'; frame-ancestors 'none'`. Operators behind a customising reverse proxy can override per-header by setting any field of the config struct to the empty string (omits that header). +- **`bodyLimitMiddleware` wired into `noAuthHandler`** in `cmd/server/main.go`. Same default cap (1 MB, configurable via `CERTCTL_MAX_BODY_SIZE`), same 413 response on overflow. Pre-H-1 only the authed surface had this protection. +- **`securityHeadersMiddleware` wired into BOTH chains** (`middlewareStack` for authed routes; `noAuthHandler` for unauth routes). Applied before the audit middleware so headers reach 4xx/5xx responses too — critical for security posture (an attacker probing for misconfiguration sees the same headers on a 401 as on a 200). +- **`CERTCTL_CONFIG_ENCRYPTION_KEY` length validation** in `internal/config/config.go::Validate()` — rejects keys shorter than 32 bytes with a structured error naming the actual length, the required minimum, and the canonical generation command. Empty keys remain accepted (downstream fail-closed sentinel handles it). +- **Tests:** `internal/api/middleware/securityheaders_test.go` (4 cases — defaults present, empty disables single header, override applied, headers on 4xx/5xx). `internal/config/config_test.go` adds 5 cases for the encryption-key length check (empty accepted, 1-byte rejected, 31-byte rejected at boundary, 32-byte accepted, 44-byte realistic operator key accepted). + +### Audit findings closed + +- `cat-s5-4936a1cf0118` (P2, EST/SCEP/PKI unauth endpoints bypass `http.MaxBytesReader`) +- `cat-s11-missing_security_headers` (P2, no CSP / HSTS / X-Frame-Options on responses) +- `cat-r-encryption_key_no_length_validation` (P2, encryption key accepted with zero entropy validation) + +### Known follow-ups (deferred from H-1 scope) + +A weak-key dictionary check (reject `password123`, common ASCII patterns) is deferred — adds operational friction with low marginal entropy gain at the 32-byte minimum. CSP `'unsafe-inline'` for styles is required because Tailwind via Vite injects per-component `