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2 Commits

Author SHA1 Message Date
shankar0123 17b30c1f7f auth-bundle-2 Phase 4: session service (cookie minting + signature
validation, idle/absolute expiry, signing-key rotation, CSRF, GC),
15-case negative-test matrix, fail-fatal initial-key bootstrap

Phase 4 of the bundle ships the post-login session lifecycle that backs
every authenticated request once Phase 5 wires the OIDC handlers + the
session middleware. The state machine is the load-bearing primitive for
the Bundle 2 control plane: forge a session cookie and you bypass every
RBAC gate.

Service surface (internal/auth/session/service.go, ~880 LOC):

  - Service.Create(actorID, actorType, ip, ua) -> *CreateResult
    Mints a session row; signs the cookie value with the active signing
    key; returns the cookie payload AND the CSRF token plaintext for
    the handler to set on the response.
  - Service.Validate(ValidateInput) -> *Session
    Parses the cookie, looks up the signing key (incl. retired-but-in-
    retention), recomputes HMAC-SHA256, loads the session row, enforces
    revocation + absolute + idle expiry + optional IP/UA bind. Maps to
    one of 9 sentinel errors; the handler uniformly returns 401 to the
    wire (specific reason in the audit row).
  - Service.ValidateCSRF(headerValue, *Session) error
    Constant-time compares SHA-256(header) against the stored hash on
    the session row.
  - Service.UpdateLastSeen / Revoke / RevokeAllForActor
  - Service.RotateCSRFToken — mints fresh token, persists hash, returns
    plaintext; called on login completion, logout, role-change against
    actor, explicit operator rotate.
  - Service.RotateSigningKey — mints new active key, retires previous;
    retired keys stay valid for cfg.SigningKeyRetention so existing
    cookies don't immediately fail.
  - Service.EnsureInitialSigningKey — idempotent; mints first key on
    fresh deploys; emits auth.session_signing_key_bootstrap audit row
    with event_category=auth. Wired into cmd/server/main.go AFTER
    migrations + RBAC backfill, BEFORE the HTTP listener binds; failure
    is FATAL (logger.Error + os.Exit(1)) per the prompt — server refuses
    to boot rather than serve session-less.
  - Service.GarbageCollect — sweeps expired post-login sessions +
    pre-login rows >10min + retired-past-retention signing keys. Wired
    into the new internal/scheduler/scheduler.go::sessionGCLoop on a
    CERTCTL_SESSION_GC_INTERVAL tick.

Cookie wire format (load-bearing):

  v1.<session_id>.<signing_key_id>.<base64url-no-pad(HMAC-SHA256)>

The HMAC input is LENGTH-PREFIXED to defeat concatenation collisions:

  len(session_id) || ":" || session_id || ":" || len(signing_key_id) || ":" || signing_key_id

where len(...) is the ASCII decimal byte-length. Without the length
prefix, the bare-concatenation form `session_id || signing_key_id`
would let a forger swap one byte across the boundary — `<a, bc>` and
`<ab, c>` produce identical HMAC inputs. The length prefix moves the
boundary into the input itself so the two cases can never collide.

The v1. version prefix is reserved. A future incompatible upgrade
ships as v2. and the parser rejects unknown prefixes (no fallback).

CSRF token model:

  - Plaintext goes in a JS-readable certctl_csrf cookie (HttpOnly=false
    intentional; the GUI must read it to echo into X-CSRF-Token header).
  - SHA-256 hash of the plaintext lives on the session row.
  - Validation: SHA-256(X-CSRF-Token) constant-time-compared.
  - Rotated by Service.RotateCSRFToken on login / logout / role-change /
    explicit admin-trigger.

Optional defense-in-depth (default OFF):

  - CERTCTL_SESSION_BIND_IP — Validate compares client IP to row's
    recorded IP. Mismatch -> 401, audit row, session NOT auto-revoked
    (user may have legitimate IP change). Mobile + corporate-NAT
    environments leave this off.
  - CERTCTL_SESSION_BIND_USER_AGENT — same shape against UA.

Configurable lifetimes (env vars wired in internal/config/config.go):

  CERTCTL_SESSION_IDLE_TIMEOUT             1h
  CERTCTL_SESSION_ABSOLUTE_TIMEOUT         8h
  CERTCTL_SESSION_SIGNING_KEY_RETENTION    24h
  CERTCTL_SESSION_GC_INTERVAL              1h
  CERTCTL_SESSION_SAMESITE                 Lax
  CERTCTL_SESSION_BIND_IP                  false
  CERTCTL_SESSION_BIND_USER_AGENT          false

Test surface (internal/auth/session/service_test.go, ~860 LOC):

  All 15 prompt-mandated negative cases:

    1.  Tampered cookie (HMAC byte flipped near segment start where all
        6 bits are real — base64url-no-pad's last char carries only 2
        bits so a tail-flip is unreliable).
    1b. Tampered SESSION_ID segment (same HMAC-recompute outcome).
    2.  Cookie missing v1. prefix.
    3.  Cookie with unknown version prefix (v99).
    4.  Idle expiry — back-dated last_seen_at + idle_expires_at.
    5.  Absolute expiry — back-dated absolute_expires_at.
    6.  Revoked session.
    7.  Wrong signing key id (no row matches).
    8.  Cookie signed under retired-but-in-retention key SUCCEEDS.
    9.  Cookie signed under retired-past-retention key FAILS.
    10. Concatenation collision — direct evidence that
        computeHMAC("abc","de") != computeHMAC("ab","cde") AND that
        a forged-boundary-slide cookie is rejected.
    11. CSRF token missing.
    12. CSRF token mismatch (constant-time compare).
    13. IP-bind enabled + IP changed -> ErrSessionIPMismatch + audit row.
    14. UA-bind enabled + UA changed -> ErrSessionUAMismatch + audit row.
    15. EnsureInitialSigningKey RNG failure -> ErrInitialSigningKeyMintFailed
        wrap (cmd/server/main.go treats as fatal).

  Plus coverage-lift batch covering: every error wrap on every repo
  collaborator (Create, Get, UpdateLastSeen, UpdateCSRFTokenHash,
  Revoke, RevokeAllForActor, GC), every RNG-failure surface in Create /
  RotateCSRFToken / RotateSigningKey, every alg-pinning helper edge,
  the cookie parser's full negative matrix (empty, wrong segment count,
  missing prefixes, bad base64, wrong HMAC length), and a real-encryption
  round-trip via internal/crypto.EncryptIfKeySet -> DecryptIfKeySet so
  the v3-blob path is exercised end-to-end at the session-cookie level.

Coverage:

  internal/auth/session              94.5%  (floor 90)
  internal/auth/session/domain       96+%   (floor 90, Phase 1)

.github/coverage-thresholds.yml extended with 2 new gate entries
(internal/auth/session and internal/auth/session/domain). The
why: paragraphs explain why each fail-closed branch is load-bearing.

Repository extensions:

  internal/repository/session.go gains UpdateCSRFTokenHash on the
  SessionRepository interface; internal/repository/postgres/session.go
  ships the implementation. RotateCSRFToken consumes it.

Scheduler extensions:

  internal/scheduler/scheduler.go gains SessionGarbageCollector
  interface + sessionGC field + sessionGCInterval +
  SetSessionGarbageCollector + SetSessionGCInterval + sessionGCLoop.
  Pattern matches the existing acmeGCLoop: atomic.Bool guard prevents
  concurrent sweeps, sync.WaitGroup tracks for graceful shutdown,
  per-tick context.WithTimeout(1m) bounds a stuck Postgres.

Server wiring:

  cmd/server/main.go constructs sessionService AFTER the bootstrap
  block (post-RBAC backfill) and BEFORE the policy-service block.
  EnsureInitialSigningKey runs immediately; failure is fatal via
  os.Exit(1). The scheduler section wires SetSessionGarbageCollector
  + SetSessionGCInterval alongside the other interval setters and
  emits an Info log so operators can confirm the loop is enabled.

Phase 4 deviation note: Service.GarbageCollect() returns (int, error)
rather than the prompt's literal `error`. The int is the count of
session rows deleted on this sweep; the scheduler discards it (`_, err
:= ...`) but tests + future operator-facing audit rows can read it.
The wider behavior matches the spec exactly.

Verifications: gofmt clean, go vet ./internal/auth/session/...
./internal/scheduler/... ./internal/config/... ./cmd/server/...
./internal/repository/... clean, go test -short -count=1 -race green
across all 3 session packages, full repository + auth + scheduler +
config test sweeps green, no regressions in Bundle 1 packages.
2026-05-10 05:31:24 +00:00
shankar0123 b0ac24fbf8 auth-bundle-2 Phase 1: OIDC + Session + User + Breakglass domain types
Phase 1 ships the persisted-shape types Bundle 2 needs end-to-end.
No DB migrations, no service layer, no HTTP handlers; Phase 2 ships
the SQL, Phase 3+ ship the consumers. Each type has a Validate()
method that enforces the on-disk invariants the schema will mirror,
and a focused _test.go that pins each invariant's failure mode.

Per-package summary:

internal/auth/oidc/domain/ (OIDCProvider + GroupRoleMapping):
* OIDCProvider carries the operator-configured IdP record. Fields
  match the prompt's Phase 1 list plus IATWindowSeconds and
  JWKSCacheTTLSeconds (Phase 3 references these by name; landing
  them in Phase 1's domain type avoids the lying-field gap).
  ClientSecretEncrypted is opaque from this layer; it is the v2 blob
  produced by internal/crypto/encryption.go and is `json:"-"` so it
  never wire-leaks.
* Validate() rejects: invalid id prefix, empty name, non-https
  issuer_url (matches Phase 3's "JWKS endpoint MUST be HTTPS"),
  empty client_id, empty client_secret_encrypted, non-https
  redirect_uri, invalid groups_claim_format, scopes missing openid,
  IAT window outside (0, 600], JWKS cache TTL below 60s. Defaults
  applied in-place: GroupsClaimPath="groups", GroupsClaimFormat=
  "string-array", Scopes=["openid","profile","email"],
  IATWindowSeconds=300, JWKSCacheTTLSeconds=3600,
  TenantID="t-default".
* GroupRoleMapping carries the operator-configured group-to-role
  rule. Validate() pins prefix conventions ("grm-", "op-", "r-")
  and non-empty group name.
* 18 tests across happy-path + every negative invariant.

internal/auth/session/domain/ (Session + SessionSigningKey):
* Session covers BOTH the post-login row (full 1h-idle/8h-absolute
  cookie lifecycle) AND the Phase 5 pre-login row (10-minute TTL,
  carries OIDC state+nonce+PKCE verifier across the IdP redirect).
  IsPreLogin discriminates. CSRFTokenHash holds SHA-256 of the
  CSRF token plaintext (the plaintext lives in a JS-readable
  certctl_csrf cookie; storing only the hash on the row defends
  against DB-read leaks per the Phase 4 CSRF contract).
* Validate() pins: id prefix "ses-", non-empty actor id/type,
  signing key id prefix "sk-", AbsoluteExpiresAt strictly > Idle,
  IdleExpiresAt strictly > CreatedAt, CSRFTokenHash exactly 64
  lowercase hex chars when set.
* Cookie naming constants pinned by a separate test
  (TestCookieNamingConstants) so a future rename can't silently
  break the GUI's web/src/api/client.ts which reads these names by
  string.
* SessionSigningKey stores the v2-encrypted HMAC key material; the
  retired-before-created invariant catches malformed rows. 14
  tests across both types.

internal/auth/user/domain/ (User):
* Federated-human identity for SSO logins. Distinct from Bundle 1's
  free-form actor_id strings: actor_roles.actor_id = User.ID for
  federated humans (per the prompt's note about how the two
  identity systems intersect).
* WebAuthnCredentials JSONB column reserved for v3 (Decision 12);
  defaults to "[]" on Validate() so Bundle 2 + v3 share the same
  on-disk format from day one.
* Email validation is intentionally loose (basic shape: one @,
  non-empty local + domain, no whitespace, dot in domain). RFC 5321
  / 5322 grammars are not enforced; the IdP issued the email and
  we trust its shape, only rejecting gross corruption.
* 8 tests across happy-path + invalid-id + empty-email +
  malformed-email + invalid-provider-id + tenant defaulting +
  WebAuthn-credentials passthrough.

internal/auth/breakglass/domain/ (BreakglassCredential):
* Phase 7.5 type. Argon2id PHC-format password hash; Validate()
  pins the Argon2id magic prefix so non-Argon2id formats (bcrypt,
  pbkdf2, plaintext) are rejected at the persistence boundary.
* MinPasswordLengthBytes (12) + MaxPasswordLengthBytes (256)
  constants pinned by a dedicated test so the operator-facing
  password-strength contract can't drift silently.
* IsLocked(now) helper exposes the lockout state machine for the
  Phase 7.5 service to consume; the lockout window default is
  15min in the service layer.
* 9 tests across happy-path + per-invariant negative + lockout
  state machine + tenant defaulting.

Cross-cutting:
* Every type has json:"-" on the encrypted-credential field
  (ClientSecretEncrypted, KeyMaterialEncrypted, PasswordHash,
  CSRFTokenHash) so even a misconfigured handler that marshals the
  domain type directly into a response body cannot leak the
  secret. Mirrors Bundle 1's pattern for issuer/target credentials.
* Every type carries TenantID with Validate() defaulting to
  authdomain.DefaultTenantID. Forward-compat for the future
  managed-service multi-tenant activation; Bundle 2 ships
  single-tenant.

Verifications:
* gofmt -l clean across all 8 new files (one round-trip required to
  satisfy Go 1.19+ doc-comment list-formatting rules in
  session/domain/types.go).
* go vet clean on internal/auth/oidc/... + session/... + user/... +
  breakglass/...
* go test -short -count=1 green on all four new domain packages
  (49 test functions total).
* go test -short -count=1 still green on Bundle 1 packages
  (internal/auth, internal/auth/bootstrap, internal/service/auth,
  internal/config).
* govulncheck ./... clean (M-024 hard CI gate).
* All 24 ci-guards pass locally.

Phase 1 exit criteria from cowork/auth-bundle-2-prompt.md:
* All types compile: yes.
* Validators have at least 5 test cases each: yes (smallest is
  User with 8 tests; OIDCProvider has 13).
* make verify equivalent green: gofmt + vet + go test pass
  (golangci-lint deferred to CI per the same operating-rule
  pattern Phase 0 used).
2026-05-10 03:41:46 +00:00