# Crewli — Authentication Architecture

> Version: 1.0 — April 2026
> Audience: security auditors, backend developers

---

## 1. Authentication Overview

Crewli uses **stateless token-based authentication** via Laravel Sanctum. Two SPA clients communicate with a single REST API. Tokens are stored exclusively in **httpOnly cookies** set by the server — they are never exposed to JavaScript via response bodies, localStorage, or JS-readable cookies.

### Client Applications

| App | URL (dev) | URL (prod) | Purpose |
|-----|-----------|------------|---------|
| App | localhost:5174 | crewli.app | Organiser dashboard + platform admin (`/platform/*` for super_admin) |
| Portal | localhost:5175 | portal.crewli.app | Volunteers, artists, suppliers |

### Access Modes

The Portal supports two access modes:

1. **Cookie-based** (`auth:sanctum`): volunteers and crew who have a `user_id` — login with email/password, httpOnly cookie set on login
2. **Token-based** (`portal.token` middleware): artists, suppliers, press — stateless per-request token via `Authorization: Bearer` header or `?token=` query parameter. No cookies involved.

---

## 2. Cookie Specification

| App | Cookie Name | Domain | Secure | httpOnly | SameSite | Max-Age |
|-----|-------------|--------|--------|----------|----------|---------|
| App | `crewli_app_token` | `.crewli.app` (prod) / `localhost` (dev) | Yes (prod) | Yes | Strict | 7 days |
| Portal | `crewli_portal_token` | `.crewli.app` (prod) / `localhost` (dev) | Yes (prod) | Yes | Strict | 7 days |

Each SPA gets its own cookie name to prevent shared auth state between apps. The cookie domain is configured via `SESSION_DOMAIN` in `.env`.

---

## 3. Token Lifecycle

### Creation

On successful login (`POST /auth/login`), the server:
1. Validates credentials via `Auth::attempt()`
2. Creates a Sanctum personal access token
3. Resolves the cookie name from the `Origin` header
4. Returns user data in the JSON body (no token in body)
5. Attaches the token as a `Set-Cookie` header with httpOnly flag

### Validation

The `CookieBearerToken` middleware (registered before `auth:sanctum` in the API middleware stack):
1. Reads the `Origin` (or `Referer`) header to identify which app is making the request
2. Resolves the correct cookie name for that app (e.g. portal origin → `crewli_portal_token`)
3. Reads only that cookie and sets `Authorization: Bearer` on the request
4. Sanctum's existing token validation processes the header normally

**Cross-app isolation:** In local development, both SPAs share `localhost` (different ports). Browsers do not scope cookies by port, so both app cookies are sent with every API request. The middleware prevents cross-app authentication by only reading the cookie that matches the requesting app's Origin header. Without this, logging into one app would authenticate the other.

If the `Origin` header is absent (e.g. server-to-server requests), the middleware falls back to the first available cookie. If an `Authorization` header is already present (e.g. from the portal token flow), the middleware skips cookie injection entirely.

### Rotation

`POST /auth/refresh` (authenticated endpoint):
1. Revokes the current access token
2. Creates a new token
3. Returns user data with a new httpOnly cookie
4. Logs the refresh event

Clients should call this endpoint periodically (recommended: every 24 hours) to rotate tokens.

### Expiration

Tokens expire after **7 days** (configured in `config/sanctum.php`). After expiration, Sanctum rejects the token and the client receives a 401. The cookie's `Max-Age` matches the token expiration.

### Revocation

Tokens are revoked on:
- **Logout** (`POST /auth/logout`): current token deleted, cookie expired
- **Password reset**: all user tokens revoked
- **Password change**: other session tokens revoked
- **Email change verification**: all user sessions revoked
- **Token refresh**: old token replaced with new one

---

## 4. CSRF Protection

**CSRF tokens are not required.** The `SameSite=Strict` cookie attribute prevents the browser from sending the auth cookie on cross-origin requests. This means:

- A malicious site cannot forge authenticated requests because the cookie is never attached to cross-origin submissions
- `SameSite=Strict` is stricter than `Lax` — even top-level navigations from other sites will not include the cookie

Reference: [OWASP CSRF Prevention Cheat Sheet — SameSite Cookie Attribute](https://cheatsheetseries.owasp.org/cheatsheets/Cross-Site_Request_Forgery_Prevention_Cheat_Sheet.html#samesite-cookie-attribute)

---

## 5. Attack Surface Analysis

### XSS — Token Theft

**Mitigated.** The bearer token is stored in an `httpOnly` cookie and is never present in:
- The JSON response body
- `localStorage` or `sessionStorage`
- JS-readable cookies (`document.cookie`)

Even if an XSS vulnerability exists, the attacker cannot read the token. They can make authenticated requests from the user's browser session, but cannot exfiltrate the token for use elsewhere.

### CSRF — Cross-Site Request Forgery

**Mitigated.** `SameSite=Strict` prevents the browser from attaching the cookie to any request originating from a different site, including form submissions and top-level navigations.

### Network Interception — Token Theft

**Mitigated in production.** The `Secure` flag ensures the cookie is only sent over HTTPS connections. In development (localhost), `Secure` is disabled to allow HTTP.

### Server Compromise — Token Theft

**Partially mitigated.** Sanctum hashes tokens in the `personal_access_tokens` table using SHA-256. An attacker with database read access sees hashed tokens, not plaintext values. However, an attacker with full server access could intercept tokens in memory.

### Token Fixation

**Not applicable.** Tokens are generated server-side using cryptographically secure random values. The client never provides or influences the token value.

---

## 6. Portal Token-Based Flow (Artists / Suppliers)

This flow is separate from the httpOnly cookie system and is NOT affected by this architecture.

### How It Works

1. The portal generates a unique token per artist/supplier, stored as a SHA-256 hash in the `artists` or `production_requests` table
2. The plaintext token is sent to the person (e.g. via email link)
3. The person accesses a portal URL with the token as a query parameter or `Authorization: Bearer` header
4. `PortalTokenMiddleware` validates the hash, resolves the person and event context
5. The request proceeds with `portal_context`, `portal_person`, and `portal_event` attributes

### Security Properties

- Tokens are hashed at rest (SHA-256)
- No cookies or sessions involved — each request is independently authenticated
- Token validity is tied to event status (draft and closed events reject tokens)
- No user account required — the token IS the identity

---

## 7. Middleware Stack (Relevant Portion)

```
Request
  → CookieBearerToken (reads cookie → injects Authorization header)
  → auth:sanctum (validates bearer token)
  → Controller
```

For portal token routes:
```
Request
  → portal.token (validates portal-specific token)
  → Controller
```

---

## 8. Configuration Reference

| Setting | Location | Purpose |
|---------|----------|---------|
| `SESSION_DOMAIN` | `.env` | Cookie domain (`.crewli.app` in prod, `localhost` in dev) |
| `FRONTEND_APP_URL` | `.env` / `config/app.php` | App SPA origin |
| `FRONTEND_PORTAL_URL` | `.env` / `config/app.php` | Portal SPA origin |
| `sanctum.expiration` | `config/sanctum.php` | Token TTL (7 days = 10080 minutes) |

---

## 9. Multi-Factor Authentication (MFA)

Crewli supports enterprise-grade MFA with three verification methods, trusted device management, role-based enforcement, and admin reset capability.

### 9.1 Verification Methods

| Method | Type | Expiry | Notes |
|--------|------|--------|-------|
| TOTP | Authenticator app (Google Authenticator, Authy, etc.) | 30s per code | Primary, most secure. Secret stored encrypted. |
| Email code | 6-digit code sent via EmailService | 10 min | Fallback for TOTP users, or standalone method. Rate-limited: 1 code per 60s. |
| Backup codes | 10 single-use codes (XXXX-XXXX format) | Never | Generated at MFA setup. Stored as bcrypt hashes. Last resort recovery. |

### 9.2 Login Flow with MFA

```
Client                              API
  │                                   │
  │  POST /auth/login                 │
  │  { email, password }              │
  │ ─────────────────────────────────►│
  │                                   │ ── Validate credentials
  │                                   │ ── Check MFA enabled?
  │                                   │
  │     ┌── MFA NOT enabled ──────────┤
  │     │   Return auth token (cookie)│
  │     │                             │
  │     └── MFA enabled ─────────────┤
  │         │                         │
  │         ├── Trusted device? ─ YES ─ Return auth token (skip MFA)
  │         │                         │
  │         └── No trusted device ────┤
  │              Return mfa_required  │
  │              + mfa_session_token  │
  │  ◄────────────────────────────────│
  │                                   │
  │  POST /auth/mfa/verify            │
  │  { mfa_session_token, code,       │
  │    method, trust_device? }        │
  │ ─────────────────────────────────►│
  │                                   │ ── Verify code
  │                                   │ ── Optionally trust device
  │  ◄── auth token (cookie) ─────────│
```

### 9.3 MFA Session

After successful password authentication, if MFA is required, the API creates a temporary MFA session:
- Stored in Redis/Cache with prefix `mfa_session:`
- TTL: 10 minutes
- Contains: `user_id`, `ip_address`, `created_at`
- IP address is checked on verification — if it changes, the session is invalidated
- Session is consumed (deleted) after successful MFA verification

### 9.4 Trusted Devices

Users can opt to trust a device during MFA verification. Trusted devices:
- Skip MFA on subsequent logins for 30 days
- Are identified by a SHA-256 hash of `device_fingerprint + user_id`
- The `X-Device-Fingerprint` header must be sent with login requests
- Can be listed, individually revoked, or all revoked by the user
- Are stored in the `trusted_devices` table with ULID primary key

### 9.5 Backup Codes

- 10 codes generated at MFA setup (format: `XXXX-XXXX`)
- Stored as bcrypt hashes — plain codes shown to user only once
- Each code is single-use (marked `used` + `used_at` on verification)
- Can be regenerated (requires TOTP verification)
- Input normalization: spaces and dashes stripped, case-insensitive

### 9.6 Role-Based Enforcement

MFA is required (enforced) for:
- `super_admin` — always
- `org_admin` — always
- Any user in an organisation with `settings.enforce_mfa = true`
- Any user with `mfa_enforced = true` flag

When MFA is required but not yet set up, login succeeds but includes `mfa_setup_required: true` flag. The frontend should redirect to MFA setup.

### 9.7 Admin Reset

Platform admins (`super_admin`) can force-disable MFA for any user via `POST /admin/users/{user}/reset-mfa`. This:
- Clears all MFA data (secret, backup codes, email codes, trusted devices)
- Logs the action in the activity log with `mfa.admin_reset` event
- The user must re-enable MFA on next login if enforcement policies apply

### 9.8 Database Tables

| Table | PK Type | Purpose |
|-------|---------|---------|
| `users` (MFA columns) | — | `mfa_enabled`, `mfa_method`, `mfa_secret` (encrypted), `mfa_confirmed_at`, `mfa_enforced` |
| `mfa_backup_codes` | auto-increment | Hashed single-use recovery codes |
| `mfa_email_codes` | auto-increment | Temporary 6-digit email verification codes |
| `trusted_devices` | ULID | Device trust records with expiry |

### 9.9 Key Files

| File | Purpose |
|------|---------|
| `app/Services/MfaService.php` | Central MFA logic — setup, verification, backup codes, trusted devices, enforcement |
| `app/Enums/MfaMethod.php` | TOTP, EMAIL, BACKUP_CODE enum |
| `app/Http/Controllers/Api/V1/Auth/MfaSetupController.php` | Authenticated MFA setup/disable/status endpoints |
| `app/Http/Controllers/Api/V1/Auth/MfaVerifyController.php` | Login-flow MFA verification (unauthenticated) |
| `app/Http/Controllers/Api/V1/Auth/TrustedDeviceController.php` | Trusted device management |

---

## 10. Impersonation

### 10.1 Overview

Platform admins (`super_admin`) can impersonate other users to investigate issues. The system uses a **header-based approach** — the admin's own httpOnly cookie session is never modified. Instead, the frontend sends an `X-Impersonate-User` header, and a middleware swaps the auth context per-request.

### 10.2 Security Controls

| Control | Implementation |
|---------|---------------|
| **MFA at start** | Admin must provide a valid TOTP, email, or backup code to begin impersonation |
| **Admin MFA required** | Admin's MFA must be enabled (`mfa_enabled = true`) |
| **No super_admin targets** | Cannot impersonate another super_admin |
| **No nesting** | Cannot start a second impersonation while one is active |
| **No double-impersonation** | Cannot impersonate a user already being impersonated by another admin |
| **IP pinning** | If the admin's IP changes mid-session, the session is terminated |
| **Sensitive route blocking** | Auth, MFA, password, email, profile, and impersonation routes are blocked during impersonation |
| **Sliding TTL** | Sessions auto-expire after 60 minutes; each request extends the window |
| **Immutable audit** | Every session is recorded in `impersonation_sessions` with no soft deletes |

### 10.3 Flow

```
Admin (with httpOnly cookie)                  API
  │                                            │
  │  POST /admin/impersonate/{user}            │
  │  { reason, mfa_code, mfa_method }         │
  │ ──────────────────────────────────────────►│
  │                                            │ ── Verify admin is super_admin
  │                                            │ ── Verify admin has MFA enabled
  │                                            │ ── Verify target is not super_admin
  │                                            │ ── Check no active session (admin or target)
  │                                            │ ── Verify MFA code
  │                                            │ ── Create ImpersonationSession (DB)
  │                                            │ ── Store session ID in cache (60 min TTL)
  │  ◄── session + user data ─────────────────│
  │                                            │
  │  GET /any-route                            │
  │  Cookie: crewli_app_token=...              │
  │  X-Impersonate-User: {target_user_id}     │
  │ ──────────────────────────────────────────►│
  │                                            │ ── CookieBearerToken: inject admin auth
  │                                            │ ── auth:sanctum: validate admin token
  │                                            │ ── HandleImpersonation middleware:
  │                                            │    1. Read X-Impersonate-User header
  │                                            │    2. Check sensitive route block list
  │                                            │    3. Validate cache session (admin+target)
  │                                            │    4. Check IP matches session
  │                                            │    5. Extend sliding TTL
  │                                            │    6. Store impersonator in request attributes
  │                                            │    7. Swap auth: setUser(targetUser)
  │                                            │    8. Increment actions_count
  │                                            │ ── Controller sees targetUser as auth user
  │  ◄── response (as target user) ───────────│
  │                                            │
  │  POST /admin/stop-impersonation            │
  │  (NO X-Impersonate-User header)            │
  │ ──────────────────────────────────────────►│
  │                                            │ ── Admin auth from cookie
  │                                            │ ── End session (DB + cache)
  │  ◄── admin user data ─────────────────────│
```

### 10.4 Blocked Routes During Impersonation

The `HandleImpersonation` middleware blocks these route prefixes when the `X-Impersonate-User` header is present:

- `auth/password` — password management
- `auth/logout` — would affect admin's session
- `auth/mfa` — MFA setup/verify/status
- `auth/trusted-devices` — device trust management
- `me/profile` — profile updates
- `me/change-password` — password changes
- `me/change-email` — email changes
- `admin/impersonate` — no nesting via API
- `verify-email-change` — email verification

### 10.5 Activity Log Integration

During an active impersonation session, `AppServiceProvider` hooks into `Activity::saving()` and automatically adds:
- `impersonated_by.user_id` — the admin's user ID
- `impersonated_by.name` — the admin's full name
- `impersonated_by.email` — the admin's email
- `impersonation_session_id` — the session ID

This applies to **all** activity log entries, not just impersonation-specific events.

### 10.6 Database Table

**`impersonation_sessions`** — immutable audit table (no soft deletes)

| Column | Type | Notes |
|--------|------|-------|
| `id` | ULID | PK |
| `admin_id` | ULID FK | → users |
| `target_user_id` | ULID FK | → users |
| `reason` | string | Admin-provided reason for impersonation |
| `mfa_method` | string(20) | Which MFA method was used to verify |
| `ip_address` | string(45) | Admin's IP at session start |
| `user_agent` | text nullable | Admin's user agent |
| `started_at` | timestamp | Session start time |
| `ended_at` | timestamp nullable | NULL = still active |
| `expires_at` | timestamp | Auto-expiry time (sliding, 60 min) |
| `end_reason` | string(50) nullable | manual, expired, ip_changed, admin_kill_all |
| `actions_count` | unsigned int | Number of API requests made during session |

**Indexes:** `(admin_id, ended_at)`, `(target_user_id, ended_at)`, `(started_at)`

### 10.7 Key Files

| File | Purpose |
|------|---------|
| `app/Services/ImpersonationService.php` | Session lifecycle, MFA verification, cache management |
| `app/Http/Middleware/HandleImpersonation.php` | Per-request header validation, auth swap, route blocking |
| `app/Http/Controllers/Api/V1/Admin/AdminImpersonationController.php` | Start, stop, status, send-mfa-code endpoints |
| `app/Http/Requests/Admin/StartImpersonationRequest.php` | Validation for start request |
| `app/Models/ImpersonationSession.php` | Eloquent model with `HasUlids`, `scopeActive()` |
| `app/Http/Resources/Admin/ImpersonationSessionResource.php` | API resource for session data |