fix(security): constant-time password-reset (flatten account-enumeration timing)

Queues the reset-link notification so sendResetLink returns in constant time regardless
of account existence; resetPassword does equivalent dummy verify work for unknown/no-2FA
users. Closes the timing side-channels flagged on the forgot-password review.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

app/Livewire/Auth/ForgotPassword.php

@@ -11,10 +11,17 @@ use Illuminate\Validation\Rules\Password;
 use Illuminate\Validation\ValidationException;
 use Livewire\Attributes\Layout;
 use Livewire\Component;
+use PragmaRX\Google2FAQRCode\Google2FA;
 
 #[Layout('layouts.auth')]
 class ForgotPassword extends Component
 {
+    /** Fixed throwaway base32 secret for the dummy TOTP verify on the no-user/no-2FA branch. */
+    private const DUMMY_TOTP_SECRET = 'ABCDEFGHIJKLMNOP';
+
+    /** Fixed throwaway bcrypt hash (cost 12) for the dummy password comparison on that branch. */
+    private const DUMMY_PASSWORD_HASH = '$2y$12$d9GooWgw17GrZ703OLFEDuuCXPvJs0vc/YLflA2JA70Mm6.I.3f.W';
+
     public string $email = '';
 
     public string $code = '';
@@ -40,7 +47,15 @@ class ForgotPassword extends Component
         }
 
         $this->validate(['email' => ['required', 'email']]);
+
+        // The notification is queued (see User::sendPasswordResetNotification), so this only ever
+        // pushes a job — no synchronous SMTP. Swallow any transport/queue error so that neither
+        // latency nor an exception can distinguish a known address from an unknown one.
+        try {
             \Illuminate\Support\Facades\Password::sendResetLink(['email' => $this->email]);
+        } catch (\Throwable) {
+            // Intentionally ignored — the response is identical regardless (auth.reset_link_sent).
+        }
 
         // Generic — never reveal whether the email exists.
         $this->dispatch('notify', message: __('auth.reset_link_sent'));
@@ -64,9 +79,15 @@ class ForgotPassword extends Component
 
         $user = User::where('email', $this->email)->first();
 
-        $ok = $user
-            && $user->hasTwoFactorEnabled()
-            && ($user->verifyTotp($this->code) || $user->useRecoveryCode($this->code));
+        if ($user && $user->hasTwoFactorEnabled()) {
+            $ok = $user->verifyTotp($this->code) || $user->useRecoveryCode($this->code);
+        } else {
+            // No account, or one without 2FA: run equivalent dummy crypto so this branch costs
+            // about as much as a real wrong-code attempt — the verification path must not be a
+            // timing oracle that distinguishes a known address.
+            $this->burnVerificationTime();
+            $ok = false;
+        }
 
         if (! $ok) {
             RateLimiter::hit($key, 60);
@@ -95,6 +116,24 @@ class ForgotPassword extends Component
         return $this->redirect(route('login'), navigate: true);
     }
 
+    /**
+     * Constant dummy verification for the no-account / no-2FA branch: mirrors the crypto work a
+     * real wrong-code attempt does (a Google2FA HMAC verify + a bcrypt comparison) so response
+     * time can't be used to enumerate accounts. The results are deliberately discarded.
+     */
+    private function burnVerificationTime(): void
+    {
+        // Stand-in for User::verifyTotp() — a throwaway HMAC against a fixed dummy secret.
+        try {
+            (new Google2FA)->verifyKey(self::DUMMY_TOTP_SECRET, preg_replace('/\s+/', '', $this->code) ?? '');
+        } catch (\Throwable) {
+            // ignore — verifyTotp swallows the same failure
+        }
+
+        // Stand-in for the recovery-code path's cost — a bcrypt compare against a fixed hash.
+        Hash::check($this->code, self::DUMMY_PASSWORD_HASH);
+    }
+
     public function render()
     {
         return view('livewire.auth.forgot-password')->title(__('auth.title_forgot'));

app/Models/User.php

@@ -2,6 +2,7 @@
 
 namespace App\Models;
 
+use App\Notifications\QueuedResetPassword;
 use Database\Factories\UserFactory;
 use Illuminate\Database\Eloquent\Attributes\Fillable;
 use Illuminate\Database\Eloquent\Attributes\Hidden;
@@ -134,6 +135,16 @@ class User extends Authenticatable
         }
     }
 
+    /**
+     * Always queue the reset-password mail (never send synchronously), so the request that
+     * triggers it returns in constant time whether or not the address exists — see
+     * {@see QueuedResetPassword} and ForgotPassword::sendResetLink().
+     */
+    public function sendPasswordResetNotification(#[\SensitiveParameter] $token): void
+    {
+        $this->notify(new QueuedResetPassword($token));
+    }
+
     public function webauthnCredentials(): HasMany
     {
         return $this->hasMany(WebauthnCredential::class);

app/Notifications/QueuedResetPassword.php

@@ -0,0 +1,21 @@
+<?php
+
+namespace App\Notifications;
+
+use App\Livewire\Auth\ForgotPassword;
+use Illuminate\Auth\Notifications\ResetPassword;
+use Illuminate\Bus\Queueable;
+use Illuminate\Contracts\Queue\ShouldQueue;
+
+/**
+ * Queued variant of the framework reset-password notification.
+ *
+ * Sending the mail asynchronously keeps {@see ForgotPassword::sendResetLink()}
+ * constant-time regardless of whether the address belongs to a real account — closing the
+ * SMTP-latency account-enumeration side channel (the mail is only ever pushed onto the queue,
+ * never delivered synchronously inside the request).
+ */
+class QueuedResetPassword extends ResetPassword implements ShouldQueue
+{
+    use Queueable;
+}

tests/Feature/EmailResetTest.php

@@ -5,7 +5,7 @@ namespace Tests\Feature;
 use App\Livewire\Auth\ForgotPassword;
 use App\Livewire\Auth\ResetPassword;
 use App\Models\User;
-use Illuminate\Auth\Notifications\ResetPassword as ResetPasswordNotification;
+use App\Notifications\QueuedResetPassword as ResetPasswordNotification;
 use Illuminate\Foundation\Testing\RefreshDatabase;
 use Illuminate\Support\Facades\Hash;
 use Illuminate\Support\Facades\Notification;

tests/Feature/ForgotPasswordSmtpAwareTest.php

@@ -5,7 +5,7 @@ namespace Tests\Feature;
 use App\Livewire\Auth\ForgotPassword;
 use App\Livewire\Settings\Security;
 use App\Models\User;
-use Illuminate\Auth\Notifications\ResetPassword as ResetPasswordNotification;
+use App\Notifications\QueuedResetPassword as ResetPasswordNotification;
 use Illuminate\Foundation\Testing\RefreshDatabase;
 use Illuminate\Support\Facades\Hash;
 use Illuminate\Support\Facades\Notification;

tests/Feature/ForgotPasswordTimingTest.php

@@ -0,0 +1,139 @@
+<?php
+
+namespace Tests\Feature;
+
+use App\Livewire\Auth\ForgotPassword;
+use App\Models\User;
+use App\Notifications\QueuedResetPassword;
+use Illuminate\Contracts\Queue\ShouldQueue;
+use Illuminate\Foundation\Testing\RefreshDatabase;
+use Illuminate\Support\Facades\Hash;
+use Illuminate\Support\Facades\Notification;
+use Illuminate\Support\Facades\RateLimiter;
+use Livewire\Features\SupportTesting\Testable;
+use Livewire\Livewire;
+use PragmaRX\Google2FAQRCode\Google2FA;
+use Tests\TestCase;
+
+/**
+ * Hardening of the two low-severity account-enumeration *timing* side channels on the
+ * forgot-password screen (the message-level leak is already closed via generic copy):
+ *   (a) sendResetLink() must enqueue the reset mail (never send synchronously), so SMTP
+ *       latency/exceptions can't distinguish a known address;
+ *   (b) resetPassword() must spend comparable crypto time whether the account exists / has
+ *       2FA or not, so the verification branch isn't a timing oracle.
+ * These tests assert the *structural* equivalence of the branches (and that mail is queued),
+ * not wall-clock timing (which would be flaky).
+ */
+class ForgotPasswordTimingTest extends TestCase
+{
+    use RefreshDatabase;
+
+    private function twoFactorUser(string $email = 'admin@clusev.local'): User
+    {
+        return User::factory()->create([
+            'email' => $email,
+            'two_factor_secret' => (new Google2FA)->generateSecretKey(),
+            'two_factor_confirmed_at' => now(),
+        ]);
+    }
+
+    private function attemptReset(string $email, string $code = '123456'): Testable
+    {
+        return Livewire::test(ForgotPassword::class)
+            ->set('email', $email)->set('code', $code)
+            ->set('password', 'NewPassw0rd123')->set('password_confirmation', 'NewPassw0rd123')
+            ->call('resetPassword');
+    }
+
+    // ── (a) the reset-link mail is queued ────────────────────────────────
+    public function test_reset_link_notification_is_queued(): void
+    {
+        config(['mail.default' => 'smtp']);
+        Notification::fake();
+        $user = User::factory()->create(['email' => 'admin@clusev.local']);
+
+        Livewire::test(ForgotPassword::class)
+            ->set('email', $user->email)
+            ->call('sendResetLink')
+            ->assertHasNoErrors();
+
+        Notification::assertSentTo(
+            $user,
+            QueuedResetPassword::class,
+            fn ($notification) => $notification instanceof ShouldQueue,
+        );
+    }
+
+    public function test_send_link_swallows_transport_errors_and_stays_generic(): void
+    {
+        config(['mail.default' => 'smtp']);
+        // No user exists → Password::sendResetLink hits the INVALID_USER path; the screen must
+        // still report the generic message with no error, exactly like the existing-user case.
+        Livewire::test(ForgotPassword::class)
+            ->set('email', 'ghost@clusev.local')
+            ->call('sendResetLink')
+            ->assertHasNoErrors()
+            ->assertDispatched('notify', message: __('auth.reset_link_sent'));
+    }
+
+    // ── (b) the verification branch does constant dummy work ─────────────
+    public function test_unknown_email_invalid_branch_burns_verification_time(): void
+    {
+        Hash::spy();
+
+        $this->attemptReset('ghost@clusev.local')->assertHasErrors('code');
+
+        // The no-account branch must still run a bcrypt comparison (dummy work), matching the
+        // crypto cost of a real wrong-code attempt — otherwise it returns measurably faster.
+        Hash::shouldHaveReceived('check')->atLeast()->once();
+    }
+
+    public function test_no_2fa_user_invalid_branch_burns_verification_time(): void
+    {
+        $user = User::factory()->create(['email' => 'plain@clusev.local']);
+        $this->assertFalse($user->hasTwoFactorEnabled());
+
+        Hash::spy();
+
+        $this->attemptReset('plain@clusev.local')->assertHasErrors('code');
+
+        Hash::shouldHaveReceived('check')->atLeast()->once();
+    }
+
+    public function test_two_factor_user_wrong_code_does_not_burn_dummy_time(): void
+    {
+        // The real-verification branch uses verifyTotp/useRecoveryCode, NOT the dummy Hash::check.
+        $this->twoFactorUser();
+        Hash::spy();
+
+        $this->attemptReset('admin@clusev.local', '000000')->assertHasErrors('code');
+
+        Hash::shouldNotHaveReceived('check');
+    }
+
+    // ── structural equivalence of the invalid branches ──────────────────
+    public function test_missing_and_no_2fa_branches_are_structurally_identical(): void
+    {
+        User::factory()->create(['email' => 'real@clusev.local']);
+
+        $missing = $this->attemptReset('ghost@clusev.local');
+        $no2fa = $this->attemptReset('real@clusev.local');
+
+        foreach ([$missing, $no2fa] as $component) {
+            $component->assertHasErrors('code');
+            $component->assertNoRedirect();
+        }
+    }
+
+    public function test_unknown_email_hits_the_rate_limiter_like_a_real_account(): void
+    {
+        RateLimiter::spy();
+
+        $this->attemptReset('ghost@clusev.local')->assertHasErrors('code');
+
+        // The no-account path must increment the limiter exactly like a real account would —
+        // no fast, un-throttled enumeration loop.
+        RateLimiter::shouldHaveReceived('hit')->atLeast()->once();
+    }
+}