Laravel Security

// config/app.php
'env' => env('APP_ENV', 'production'),
'debug' => (bool) env('APP_DEBUG', false), // CRITICAL: Never true in production
'key' => env('APP_KEY'), // Must be set: php artisan key:generate

// config/session.php
'secure' => env('SESSION_SECURE_COOKIE', true),
'http_only' => true,
'same_site' => 'lax',

// Verify APP_KEY is set at boot
// bootstrap/app.php or a service provider
if (empty(config('app.key'))) {
    throw new RuntimeException('APP_KEY is not set. Run: php artisan key:generate');
}

# NEVER commit .env to version control
# .gitignore already includes .env by default

# Use .env.example with placeholders instead
DB_PASSWORD=
APP_KEY=
SANCTUM_TOKEN_PREFIX=

# Validate required variables at boot
// In AppServiceProvider::boot()
$requiredKeys = ['app.key', 'database.connections.mysql.database', 'database.connections.mysql.username'];
foreach ($requiredKeys as $key) {
    if (empty(config($key))) {
        throw new RuntimeException("Missing required config key: {$key}");
    }
}

// AppServiceProvider::boot() or middleware
if (app()->environment('production')) {
    URL::forceScheme('https');
    request()->server->set('HTTPS', 'on');
}

// config/app.php for trusted proxies (load balancers)
// Use specific IP ranges — * trusts all, allowing X-Forwarded-* spoofing
// AWS: '10.0.0.0/8', '172.16.0.0/12', '192.168.0.0/16'
'trusted_proxies' => ['10.0.0.0/8', '172.16.0.0/12'],

// Force HTTPS in production via middleware
// app/Http/Middleware/ForceHttps.php
public function handle($request, Closure $next)
{
    if (!$request->secure() && app()->environment('production')) {
        return redirect()->secure($request->getRequestUri());
    }
    return $next($request);
}

// config/sanctum.php
'stateful' => explode(',', env('SANCTUM_STATEFUL_DOMAINS', sprintf(
    '%s%s',
    'localhost,localhost:3000,127.0.0.1,127.0.0.1:8000,::1',
    env('APP_URL') ? ',' . parse_url(env('APP_URL'), PHP_URL_HOST) : ''
)));

'expiration' => 60 * 24, // Token expiration in minutes (null = never)
'token_prefix' => env('SANCTUM_TOKEN_PREFIX', ''),

// Issuing tokens with abilities
$token = $user->createToken('api-token', ['read', 'write'])->plainTextToken;

// Validate abilities on routes
Route::middleware('auth:sanctum')->group(function () {
    Route::get('/orders', function () {
        // User must have 'read' ability
        abort_unless(Auth::user()->tokenCan('read'), 403);
        // ...
    })->middleware('abilities:read');

    Route::post('/orders', function () {
        // User must have 'write' ability
        abort_unless(Auth::user()->tokenCan('write'), 403);
        // ...
    })->middleware('abilities:write');
});

// config/hashing.php
// Default is bcrypt. Argon2id is stronger.
'bcrypt' => [
    'rounds' => env('BCRYPT_ROUNDS', 12), // Increase for stronger hashing
],

'argon' => [
    'memory' => 65536,
    'threads' => 4,
    'time' => 4,
],

// Password validation in RegisterRequest
public function rules(): array
{
    return [
        'password' => [
            'required',
            'confirmed',
            Password::min(12)
                ->letters()
                ->mixedCase()
                ->numbers()
                ->symbols()
                ->uncompromised(), // Checks haveibeenpwned
        ],
    ];
}

// Rate limit login attempts
// App\Http\Controllers\Auth\AuthenticatedSessionController
protected function authenticated(Request $request, $user)
{
    if ($user->wasRecentlyLockedOut()) {
        // Notify user of suspicious login
        $user->notify(new SuspiciousLoginNotification($request->ip()));
    }
}

// config/session.php
'driver' => env('SESSION_DRIVER', 'database'), // database/redis > file
'lifetime' => env('SESSION_LIFETIME', 120),
'expire_on_close' => env('SESSION_EXPIRE_ON_CLOSE', false),
'encrypt' => env('SESSION_ENCRYPT', false),

// Regenerate session on login
// App\Http\Controllers\Auth\AuthenticatedSessionController
public function store(LoginRequest $request): RedirectResponse
{
    $request->authenticate();
    $request->session()->regenerate(); // CRITICAL: prevents session fixation
    return redirect()->intended(RouteServiceProvider::HOME);
}

// Invalidate session on logout
public function destroy(Request $request): RedirectResponse
{
    Auth::guard('web')->logout();
    $request->session()->invalidate();
    $request->session()->regenerateToken();
    return redirect('/');
}

// App\Providers\AuthServiceProvider
use App\Models\Post;
use App\Models\User;
use Illuminate\Support\Facades\Gate;

public function boot(): void
{
    Gate::define('update-post', function (User $user, Post $post): bool {
        return $user->id === $post->user_id;
    });

    Gate::define('publish-post', function (User $user): bool {
        return $user->role === 'editor' || $user->role === 'admin';
    });

    // Using before() for super-admin override
    Gate::before(function (User $user, string $ability): ?bool {
        if ($user->role === 'super-admin') {
            return true; // Grants all abilities
        }
        return null; // Fall through to normal checks
    });
}

// Usage in controllers
public function update(Request $request, Post $post): RedirectResponse
{
    Gate::authorize('update-post', $post);
    // Or: $this->authorize('update-post', $post);
    // Or: abort_unless(Auth::user()->can('update-post', $post), 403);
    // ...
}

// App\Policies\PostPolicy
class PostPolicy
{
    use HandlesAuthorization;

    public function viewAny(?User $user): bool
    {
        return true; // Public listing
    }

    public function view(?User $user, Post $post): bool
    {
        return $post->is_published || ($user && $user->id === $post->user_id);
    }

    public function create(User $user): bool
    {
        return $user->hasVerifiedEmail(); // Must verify email first
    }

    public function update(User $user, Post $post): bool
    {
        return $user->id === $post->user_id;
    }

    public function delete(User $user, Post $post): bool
    {
        return $user->id === $post->user_id && $post->created_at->diffInDays(now()) <= 30;
    }

    public function restore(User $user, Post $post): bool
    {
        return $user->role === 'admin';
    }

    public function forceDelete(User $user, Post $post): bool
    {
        return $user->role === 'super-admin';
    }
}

// Register in AuthServiceProvider
protected $policies = [
    Post::class => PostPolicy::class,
];

// Controller usage
public function show(Post $post): View
{
    $this->authorize('view', $post);
    return view('posts.show', compact('post'));
}

// Blade usage
@can('update', $post)
    <a href="{{ route('posts.edit', $post) }}">Edit</a>
@endcan

@cannot('update', $post)
    <span>You cannot edit this post</span>
@endcannot

// Using middleware in routes
Route::put('/posts/{post}', [PostController::class, 'update'])
    ->middleware('can:update,post');

Route::get('/posts/create', [PostController::class, 'create'])
    ->middleware('can:create,App\Models\Post');

// Custom authorization middleware
// app/Http/Middleware/CheckRole.php
class CheckRole
{
    public function handle(Request $request, Closure $next, string $role): mixed
    {
        if (!$request->user() || $request->user()->role !== $role) {
            abort(403, 'Unauthorized. This area requires role: ' . $role);
        }
        return $next($request);
    }
}

// Register in Kernel
protected $routeMiddleware = [
    'role' => \App\Http\Middleware\CheckRole::class,
];

// Route usage
Route::middleware(['auth', 'role:admin'])->group(function () {
    Route::get('/admin', [AdminController::class, 'index']);
});

// BAD: $guarded = [] allows ALL columns to be mass-assigned
// NEVER use $guarded = [] in production

// GOOD: Whitelist fillable attributes
final class User extends Authenticatable
{
    protected $fillable = [
        'name',
        'email',
        'phone',
        'avatar',
    ];
    // NEVER add 'role', 'is_admin', 'is_verified' here
}

// GOOD: Explicitly control which fields can be filled in requests
public function store(StoreUserRequest $request): RedirectResponse
{
    $user = User::create($request->safe()->only([
        'name', 'email', 'phone', 'avatar'
    ]));
    // $request->safe() uses validated data only
    // $request->only() is NOT safe on its own without validation rules
}

// BAD: Creating a user with request data directly
User::create($request->all()); // VULNERABLE to mass assignment!

// BETTER: Use DTOs for creation
$user = User::create($request->validated()); // Only validated fields

// GOOD: Eloquent automatically parameterizes queries
User::where('email', $userInput)->first();
User::whereRaw('email = ?', [$userInput])->first();

// GOOD: Query Builder also parameterizes
DB::table('users')->where('email', $userInput)->first();
DB::select('SELECT * FROM users WHERE email = ?', [$userInput]);

// BAD: Raw string interpolation
DB::select("SELECT * FROM users WHERE email = '{$userInput}'"); // VULNERABLE!
User::whereRaw("email = '{$userInput}'")->first(); // VULNERABLE!

// BAD: whereRaw/orderByRaw with unescaped input
User::orderByRaw($userInput); // VULNERABLE!
User::groupByRaw($userInput); // VULNERABLE!

// BAD: DB::statement with concatenation
DB::statement("INSERT INTO users (email) VALUES ('{$userInput}')"); // VULNERABLE!

final class User extends Authenticatable
{
    protected $casts = [
        'email_verified_at' => 'datetime',
        'is_admin' => 'boolean', // Cast to boolean prevents string injection
        'settings' => 'array', // Automatically json_encode/json_decode
        'metadata' => 'encrypted:array', // Laravel 11+ encrypted casting
        'password' => 'hashed', // Laravel 10+ auto-hashes on set
    ];
}

final class User extends Authenticatable
{
    // Hide sensitive attributes from JSON/API responses
    protected $hidden = [
        'password',
        'remember_token',
        'two_factor_secret',
        'two_factor_recovery_codes',
    ];

    // Append only safe computed attributes
    protected $appends = ['full_name']; // safe
    // NEVER append sensitive computed data
}

final class Post extends Model
{
    // Global scope to filter soft deleted records
    use SoftDeletes;

    // Prevent N+1 by restricting lazy loading (optional strict mode)
    // AppServiceProvider::boot()
    // Model::preventLazyLoading(!app()->isProduction());
}

// Laravel CSRF is enabled by default via VerifyCsrfToken middleware
// app/Http/Kernel.php (protected $middlewareGroups['web'])

// All POST/PUT/PATCH/DELETE forms must include @csrf
<form method="POST" action="/posts">
    @csrf
    <input type="text" name="title">
    <button type="submit">Create</button>
</form>

// app/Http/Middleware/VerifyCsrfToken.php
class VerifyCsrfToken extends Middleware
{
    // Only exclude routes that have external CSRF protection (webhooks, etc.)
    protected $except = [
        'stripe/*', // Stripe webhooks use their own signature verification
        // Avoid blanket 'api/*' — stateful Sanctum routes need CSRF.
        // Exclude only specific stateless webhook/endpoint routes.
    ];
}

<meta name="csrf-token" content="{{ csrf_token() }}">

<script>
// Axios example (Laravel ships with Axios)
axios.defaults.headers.common['X-CSRF-TOKEN'] = document.querySelector(
    'meta[name="csrf-token"]'
).getAttribute('content');

// Fetch example
fetch('/posts', {
    method: 'POST',
    headers: {
        'X-CSRF-TOKEN': document.querySelector('meta[name="csrf-token"]').getAttribute('content'),
        'Content-Type': 'application/json',
    },
    body: JSON.stringify(data),
});
</script>

{{-- SAFE: Auto-escaped by Blade --}}
{{ $userInput }}

{{-- DANGEROUS: Raw output — NEVER use with user input --}}
{!! $userInput !!}

{{-- SAFE: Only use {!! !!} with trusted content you control --}}
{!! $trustedHtmlFromYourServer !!}

{{-- GOOD: Use specific escaping directives --}}
@js($data) {{-- JSON encode for JavaScript --}}
@json($data) {{-- JSON encode in templates --}}

{{-- BAD: Direct user input in raw HTML --}}
<div>{!! $user->bio !!}</div> {{-- VULNERABLE if user provides bio --}}

// When you must allow some HTML, use a whitelist approach
use HTMLPurifier; // Requires: composer require ezyang/htmlpurifier

public function sanitizeHtml(string $dirty): string
{
    $config = \HTMLPurifier_Config::createDefault();
    $config->set('HTML.Allowed', 'p,b,i,a[href],ul,ol,li,br');
    $config->set('URI.AllowedSchemes', ['http', 'https', 'mailto']);
    $purifier = new \HTMLPurifier($config);
    return $purifier->purify($dirty);
}

// In blade:
<div>{!! $sanitizedContent !!}</div> {{-- Safe after purification --}}

{{-- SAFE: Blade @js escapes for JavaScript context --}}
<script>
    const user = @js($user); // JSON + escaped for JS context
    const settings = @json($settings); // Direct JSON encode
</script>

{{-- DANGEROUS: Manual JSON in JS context --}}
<script>
    const user = {{ json_encode($user) }}; // NOT escaped for JS!
</script>

// App\Http\Middleware\SecurityHeaders.php
class SecurityHeaders
{
    public function handle(Request $request, Closure $next): mixed
    {
        $response = $next($request);

        $response->headers->set('X-Content-Type-Options', 'nosniff');
        $response->headers->set('X-Frame-Options', 'DENY');
        $response->headers->set('X-XSS-Protection', '1; mode=block');
        $response->headers->set('Referrer-Policy', 'strict-origin-when-cross-origin');
        $response->headers->set(
            'Content-Security-Policy',
            "default-src 'self'; script-src 'self'; style-src 'self' 'unsafe-inline'; img-src 'self' data: https:; font-src 'self'; connect-src 'self'; frame-ancestors 'none'"
        );

        return $response;
    }
}

// Register in kernel
protected $middleware = [
    \App\Http\Middleware\SecurityHeaders::class,
];

final class StorePostRequest extends FormRequest
{
    public function authorize(): bool
    {
        return $this->user()?->can('create', Post::class) ?? false;
    }

    public function rules(): array
    {
        return [
            'title' => ['required', 'string', 'max:255', 'sanitize_html'],
            'content' => ['required', 'string', 'max:10000'],
            'image' => [
                'required',
                'image',
                'mimes:jpg,jpeg,png,gif,webp', // Whitelist specific types
                'max:2048', // 2MB max
            ],
            'tags' => ['array'],
            'tags.*' => ['integer', 'exists:tags,id'],
        ];
    }

    public function messages(): array
    {
        return [
            'title.max' => 'Post title must not exceed 255 characters.',
            'image.max' => 'Image must be under 2MB.',
        ];
    }

    // Sanitize input after validation
    public function validated($key = null, $default = null): mixed
    {
        $validated = parent::validated();
        $validated['title'] = strip_tags($validated['title']);
        return $key ? ($validated[$key] ?? $default) : $validated;
    }
}

// app/Rules/StrongPassword.php
class StrongPassword implements Rule
{
    public function passes($attribute, $value): bool
    {
        return preg_match('/^(?=.*[a-z])(?=.*[A-Z])(?=.*\d)(?=.*[@$!%*?&#^()_\-+=])[A-Za-z\d@$!%*?&#^()_\-+=]{12,}$/', $value);
    }

    public function message(): string
    {
        return 'The :attribute must be at least 12 characters with uppercase, lowercase, number, and symbol.';
    }
}

// app/Rules/NotBlacklistedDomain.php
class NotBlacklistedDomain implements Rule
{
    private array $blacklisted = ['mailinator.com', 'guerrillamail.com'];

    public function passes($attribute, $value): bool
    {
        $domain = substr(strrchr($value, '@'), 1);
        return !in_array(strtolower($domain), $this->blacklisted);
    }

    public function message(): string
    {
        return 'Email from disposable domains is not allowed.';
    }
}

// App/Providers/RouteServiceProvider
protected function configureRateLimiting(): void
{
    RateLimiter::for('api', function (Request $request) {
        return Limit::perMinute(60)->by($request->user()?->id ?: $request->ip());
    });

    RateLimiter::for('auth', function (Request $request) {
        return Limit::perMinute(5)->by($request->ip())
            ->response(function () {
                return response()->json([
                    'message' => 'Too many login attempts. Try again in 1 minute.',
                ], 429);
            });
    });

    RateLimiter::for('uploads', function (Request $request) {
        return Limit::perHour(10)->by($request->user()?->id ?? $request->ip())
            ->response(function () {
                return response()->json([
                    'message' => 'Upload limit reached. Try again later.',
                ], 429);
            });
    });
}

// Route usage
Route::middleware(['auth:sanctum', 'throttle:api'])->group(function () {
    Route::apiResource('posts', PostController::class);
});

Route::post('/login', [AuthController::class, 'login'])
    ->middleware('throttle:auth');

// Sanctum (recommended for most apps — simple, first-party, SPA)
// config/sanctum.php
'expiration' => 60 * 24, // Tokens expire after 24 hours
'model' => User::class,

// Issuing scoped tokens
$token = $user->createToken('client-name', [
    'posts:read',
    'posts:write',
])->plainTextToken;

// Middleware scoping
Route::middleware('auth:sanctum')->group(function () {
    Route::get('/posts', [PostController::class, 'index'])
        ->middleware('abilities:posts:read');

    Route::post('/posts', [PostController::class, 'store'])
        ->middleware('abilities:posts:write');
});

// Passport (OAuth2 — for third-party clients or complex auth flows)
// Install: composer require laravel/passport
Passport::tokensExpireIn(now()->addDays(15));
Passport::refreshTokensExpireIn(now()->addDays(30));
Passport::personalAccessTokensExpireIn(now()->addMonths(6));

// config/cors.php
return [
    'paths' => ['api/*', 'sanctum/csrf-cookie'],
    'allowed_methods' => ['*'],
    'allowed_origins' => explode(',', env('CORS_ALLOWED_ORIGINS', '')), // Whitelist specific origins
    'allowed_origins_patterns' => [],
    'allowed_headers' => ['*'],
    'exposed_headers' => ['X-Total-Count', 'X-Pagination-Page'],
    'max_age' => 0,
    'supports_credentials' => true, // Required for Sanctum SPA auth
];

// NEVER: Allow all origins in production unless absolutely necessary
// 'allowed_origins' => ['*'], // Only for truly public APIs

public function rules(): array
{
    return [
        'document' => [
            'required',
            'file',
            'mimes:pdf,doc,docx,xls,xlsx', // Whitelist specific MIME types
            'max:10240', // 10MB
            'extensions:pdf,doc,docx,xls,xlsx', // Verify extension matches MIME
        ],
        'avatar' => [
            'nullable',
            'image', // Ensures it's a valid image
            'mimes:jpg,jpeg,png,webp',
            'max:2048',
            'dimensions:min_width=100,min_height=100,max_width=2000,max_height=2000',
        ],
    ];
}

// Store files outside public directory
$path = $request->file('document')->store('documents', 'local');
// Never use 'public' disk for sensitive documents

// Use signed URLs for temporary file access
use Illuminate\Support\Facades\Storage;

public function download(Request $request, string $path)
{
    // Generate temporary signed URL (expires in 15 minutes)
    $url = Storage::temporaryUrl($path, now()->addMinutes(15));

    // Validate user has permission
    $this->authorize('download', $path);

    return redirect($url);
}

// Storage configuration for cloud with encryption
// config/filesystems.php
's3' => [
    'driver' => 's3',
    'key' => env('AWS_ACCESS_KEY_ID'),
    'secret' => env('AWS_SECRET_ACCESS_KEY'),
    'region' => env('AWS_DEFAULT_REGION'),
    'bucket' => env('AWS_BUCKET'),
    'url' => env('AWS_URL'),
    'endpoint' => env('AWS_ENDPOINT'),
    'use_path_style_endpoint' => env('AWS_USE_PATH_STYLE_ENDPOINT', false),
    'throw' => false,
    'server_side_encryption' => 'AES256', // Encrypt at rest
],

# Always audit dependencies in CI
composer audit

# Pin major versions in composer.json
"laravel/framework": "^11.0",
"spatie/laravel-permission": "^6.0"

# Check for abandoned packages
composer why-not

# Keep lock file in version control (it pins exact versions)
# Run `composer update` deliberately, never in CI/CD

# .env file (NEVER commit)
# .gitignore includes .env by default

APP_KEY=base64:abc123...
DB_PASSWORD=secure_password
STRIPE_KEY=sk_live_...
SANCTUM_TOKEN_PREFIX=myapp_

# For production: Use a secret manager
# Deploy with: env $(aws secretsmanager get-secret-value --secret-id prod/db | jq ...) php artisan serve

# Validate secrets at boot (AppServiceProvider::boot)
$secrets = ['services.stripe.key', 'services.stripe.webhook_secret'];
foreach ($secrets as $key) {
    if (empty(config($key))) {
        Log::critical("Missing secret: {$key}");
    }
}

// Define a named rate limiter (typically in AppServiceProvider::boot())
RateLimiter::for('payments', fn () => Limit::perMinute(5));

// Encrypt sensitive job data by implementing the interface
final class ProcessPaymentJob implements ShouldQueue, ShouldBeEncrypted
{
    use Dispatchable, InteractsWithQueue, Queueable, SerializesModels;

    public function __construct(
        private readonly string $paymentIntentId, // Public IDs are fine
        private readonly string $cardFingerprint, // Encrypted via ShouldBeEncrypted
    ) {}

    public function handle(): void
    {
        // Process payment
    }

    // Limit retries and delay between attempts
    public function retryUntil(): Carbon
    {
        return now()->addMinutes(5);
    }

    // Rate limit how many jobs of this type can run
    public function middleware(): array
    {
        return [
            new RateLimited('payments'),
        ];
    }
}

// config/logging.php
'channels' => [
    'security' => [
        'driver' => 'single',
        'path' => storage_path('logs/security.log'),
        'level' => 'warning',
    ],
],

// Audit log helper
final class SecurityLogger
{
    public static function log(string $event, array $context = []): void
    {
        Log::channel('security')->warning($event, array_merge([
            'user_id' => Auth::id(),
            'ip' => request()->ip(),
            'user_agent' => request()->userAgent(),
            'url' => request()->fullUrl(),
            'timestamp' => now()->toIso8601String(),
        ], $context));
    }
}

// Usage
SecurityLogger::log('failed_login_attempt', ['email' => $email]);
SecurityLogger::log('password_change');
SecurityLogger::log('role_change', ['target_user' => $targetId, 'new_role' => 'admin']);
SecurityLogger::log('suspicious_activity', ['reason' => 'multiple_attempts_from_different_ips']);