Offer «Entrar con Pireon» on the panel's login page

Under the e-mail and password form, a button takes the redirect flow
(Authorization Code + PKCE), so the password is only ever typed at the
identity server. The routes for it were already there; the page had no
way to reach them.

A Pireon client allows one grant type and the panel's is a password
client, so the redirect flow can use its own: PIREON_REDIRECT_CLIENT_ID
and PIREON_REDIRECT_CLIENT_SECRET (the main client when they are empty).
The button shows up once that client is set, or with
PIREON_REDIRECT_LOGIN=true. Each session renews its token with the
client that issued it.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

.env.example

@@ -76,6 +76,15 @@ PIREON_CLIENT_SECRET=
 PIREON_REDIRECT_URI="${APP_URL}/auth/callback"
 PIREON_SCOPES=account:read
 
+# «Entrar con Pireon» (Authorization Code + PKCE) under the login form. A Pireon
+# client allows one grant type: the one above is the password client, so
+# register another for authorization_code with the redirect URI above and put
+# it here; the button shows up once it is set. PIREON_REDIRECT_LOGIN=true shows
+# it with the client above instead (when that one allows authorization_code).
+PIREON_REDIRECT_CLIENT_ID=
+PIREON_REDIRECT_CLIENT_SECRET=
+# PIREON_REDIRECT_LOGIN=
+
 # Grants. The panel's sign-in form uses the password grant, so turning this off
 # locks everyone out of the panel as well as out of POST /api/v1/auth/token.
 PIREON_PASSWORD_GRANT=true

README.md

@@ -70,9 +70,20 @@ al remoto por si alguien comitea con `--no-verify`.
 En `https://oauth.pireon.dev` crea un cliente OAuth con:
 
 - **Grant types**: `password` — es el que usa el formulario de acceso del panel
+
+Para ofrecer también **«Entrar con Pireon»** (redirección con Authorization
+Code + PKCE, donde la contraseña solo se escribe en el servidor de identidad),
+crea un segundo cliente, porque cada cliente admite un único grant:
+
+- **Grant types**: `authorization_code`
 - **Redirect URI**: `https://tu-dominio/auth/callback` (en local,
-  `http://localhost:8000/auth/callback`), solo si quieres conservar el flujo de
-  redirección, que sigue disponible aunque el panel ya no lo use
+  `http://localhost:8000/auth/callback`)
+
+y pon sus credenciales en `PIREON_REDIRECT_CLIENT_ID` y
+`PIREON_REDIRECT_CLIENT_SECRET`. El botón aparece bajo el formulario en cuanto
+están; `PIREON_REDIRECT_LOGIN` lo fuerza (`true`, si el cliente principal
+admite los dos grants) o lo quita (`false`). Cada sesión renueva su token con el
+cliente que lo emitió.
 
 Copia las credenciales al `.env`:
 

app/Filament/Pages/Auth/PireonLogin.php

@@ -10,6 +10,7 @@ use App\Services\Pireon\PireonClient;
 use App\Services\Pireon\PireonException;
 use App\Services\Pireon\TokenStore;
 use DanHarrin\LivewireRateLimiting\Exceptions\TooManyRequestsException;
+use Filament\Actions\Action;
 use Filament\Auth\Http\Responses\Contracts\LoginResponse;
 use Filament\Auth\Pages\Login;
 use Filament\Facades\Filament;
@@ -27,6 +28,9 @@ use SensitiveParameter;
  * usable password column — but the person signing in never sees that. They
  * type their credentials here and land in the panel.
  *
+ * «Entrar con Pireon», under the form, takes the redirect flow instead: the
+ * password is then typed at the identity server only.
+ *
  * The cost of that convenience is stated plainly because it is real: this
  * application now handles the password rather than never seeing it. It is sent
  * straight to the identity server over the password grant and is never stored,
@@ -53,6 +57,25 @@ class PireonLogin extends Login
         return __('pireon.sign_in_intro');
     }
 
+    /**
+     * Under «Entrar», «Entrar con Pireon»: the redirect flow, for whoever would
+     * rather not type their password here (or signs in some other way there).
+     */
+    protected function getFormActions(): array
+    {
+        $actions = parent::getFormActions();
+
+        if (config('pireon.redirect_login') && PireonClient::forRedirect()->isConfigured()) {
+            $actions[] = Action::make('pireon')
+                ->label(__('pireon.continue_with_pireon'))
+                ->url(route('auth.redirect'))
+                ->color('gray')
+                ->outlined();
+        }
+
+        return $actions;
+    }
+
     /**
      * Filament's own flow checks the credentials against the local user table.
      * There are no local passwords here, so the whole of it is replaced: the
@@ -110,7 +133,7 @@ class PireonLogin extends Login
 
         Auth::login($user, (bool) ($data['remember'] ?? false));
 
-        app(TokenStore::class)->put($token);
+        app(TokenStore::class)->put($token, viaRedirect: false);
 
         if ($user->locale) {
             session()->put(config('locales.session_key'), $user->locale);

app/Http/Controllers/Auth/PireonAuthController.php

@@ -19,6 +19,8 @@ use Illuminate\Support\Facades\Log;
  *
  * The browser never sees a password belonging to this application, and the
  * authorization code alone is useless without the verifier we keep server-side.
+ * It is «Entrar con Pireon» on the login page; it uses the redirect client
+ * (`PireonClient::forRedirect()`), its own one when configured.
  */
 class PireonAuthController extends Controller
 {
@@ -38,7 +40,7 @@ class PireonAuthController extends Controller
         }
 
         try {
-            ['url' => $url, 'state' => $state, 'code_verifier' => $verifier] = $this->client->authorizationUrl();
+            ['url' => $url, 'state' => $state, 'code_verifier' => $verifier] = PireonClient::forRedirect()->authorizationUrl();
         } catch (PireonException $e) {
             return $this->fail($e, route('login'));
         }
@@ -81,7 +83,7 @@ class PireonAuthController extends Controller
         }
 
         try {
-            $token = $this->client->exchangeCode((string) $request->query('code'), (string) $verifier);
+            $token = PireonClient::forRedirect()->exchangeCode((string) $request->query('code'), (string) $verifier);
             $identity = $this->client->identity($token->accessToken);
         } catch (PireonException $e) {
             return $this->fail($e, route('login'));
@@ -100,7 +102,7 @@ class PireonAuthController extends Controller
         $request->session()->regenerate();
 
         Auth::login($user, remember: true);
-        $this->tokens->put($token);
+        $this->tokens->put($token, viaRedirect: true);
 
         if ($user->locale) {
             $request->session()->put(config('locales.session_key'), $user->locale);

app/Services/Pireon/PireonClient.php

@@ -37,6 +37,22 @@ class PireonClient
         );
     }
 
+    /**
+     * The client for the redirect flow: its own when PIREON_REDIRECT_CLIENT_ID
+     * is set (a Pireon client allows one grant type), the main one otherwise.
+     */
+    public static function forRedirect(): self
+    {
+        $own = filled(config('pireon.redirect_client_id'));
+
+        return new self(
+            server: (string) config('pireon.server'),
+            clientId: $own ? config('pireon.redirect_client_id') : config('pireon.client_id'),
+            clientSecret: $own ? config('pireon.redirect_client_secret') : config('pireon.client_secret'),
+            redirectUri: (string) config('pireon.redirect_uri'),
+        );
+    }
+
     public function isConfigured(): bool
     {
         return filled($this->clientId);

app/Services/Pireon/TokenStore.php

@@ -18,14 +18,25 @@ class TokenStore
 {
     protected const KEY = 'pireon.token';
 
+    /** Which client issued it: a refresh token only works with that one. */
+    protected const ISSUER = 'pireon.token_issuer';
+
     public function __construct(
         protected Session $session,
         protected PireonClient $client,
     ) {}
 
-    public function put(AccessToken $token): void
+    /**
+     * @param  bool|null  $viaRedirect  Whether the redirect flow's client
+     *                                  issued it; null keeps what was said.
+     */
+    public function put(AccessToken $token, ?bool $viaRedirect = null): void
     {
         $this->session->put(self::KEY, $token->toArray());
+
+        if ($viaRedirect !== null) {
+            $this->session->put(self::ISSUER, $viaRedirect ? 'redirect' : 'password');
+        }
     }
 
     public function get(): ?AccessToken
@@ -37,7 +48,7 @@ class TokenStore
 
     public function forget(): void
     {
-        $this->session->forget(self::KEY);
+        $this->session->forget([self::KEY, self::ISSUER]);
     }
 
     /**
@@ -66,7 +77,10 @@ class TokenStore
         }
 
         try {
-            $refreshed = $this->client->refresh($token->refreshToken);
+            $issuer = $this->session->get(self::ISSUER) === 'redirect'
+                ? PireonClient::forRedirect()
+                : $this->client;
+            $refreshed = $issuer->refresh($token->refreshToken);
         } catch (PireonException) {
             // The refresh token was revoked or expired upstream.
             $this->forget();

config/pireon.php

@@ -33,6 +33,24 @@ return [
     */
     'redirect_uri' => env('PIREON_REDIRECT_URI', env('APP_URL', 'http://localhost').'/auth/callback'),
 
+    /*
+    | The redirect flow («Entrar con Pireon», Authorization Code + PKCE) can
+    | use a client of its own. A Pireon client allows one grant type, so when
+    | the one above is a password client, register another for
+    | authorization_code (redirect URI as above) and put it here. Left empty,
+    | the client above is used for both.
+    */
+    'redirect_client_id' => env('PIREON_REDIRECT_CLIENT_ID'),
+    'redirect_client_secret' => env('PIREON_REDIRECT_CLIENT_SECRET'),
+
+    /*
+    | Offer «Entrar con Pireon» under the e-mail and password form. By default
+    | only once a redirect client is set: the main one is usually a password
+    | client, and the button would fail with it. Set it to true when the main
+    | client allows authorization_code too.
+    */
+    'redirect_login' => (bool) (env('PIREON_REDIRECT_LOGIN') ?? filled(env('PIREON_REDIRECT_CLIENT_ID'))),
+
     /*
     | Scopes requested for panel sessions. We only ever need to read the
     | identity of the person logging in, so we stay minimal by default.

lang/ca/pireon.php

@@ -4,7 +4,8 @@ declare(strict_types=1);
 
 return [
     'sign_in' => 'Entra',
-    'sign_in_intro' => 'Accedeix amb el teu correu i la teva contrasenya.',
+    'sign_in_intro' => 'Accedeix amb el teu correu i la teva contrasenya, o amb el teu compte de Pireon.',
+    'continue_with_pireon' => 'Entra amb Pireon',
     'signing_in' => 'Comprovant les teves credencials…',
     'password_grant_disabled' => 'L\'accés amb contrasenya està desactivat en aquesta instal·lació. Avisa un administrador.',
     'server_unavailable' => 'El servidor d\'identitat no respon. No és cosa de les teves credencials; avisa un administrador.',

lang/en/pireon.php

@@ -4,7 +4,8 @@ declare(strict_types=1);
 
 return [
     'sign_in' => 'Sign in',
-    'sign_in_intro' => 'Sign in with your e-mail and password.',
+    'sign_in_intro' => 'Sign in with your e-mail and password, or with your Pireon account.',
+    'continue_with_pireon' => 'Sign in with Pireon',
     'signing_in' => 'Checking your credentials…',
     'password_grant_disabled' => 'Password sign-in is switched off on this installation. Please tell an administrator.',
     'server_unavailable' => 'The identity server is not responding. This is not about your credentials; please tell an administrator.',

lang/es/pireon.php

@@ -4,7 +4,8 @@ declare(strict_types=1);
 
 return [
     'sign_in' => 'Entrar',
-    'sign_in_intro' => 'Accede con tu email y tu contraseña.',
+    'sign_in_intro' => 'Accede con tu email y tu contraseña, o con tu cuenta de Pireon.',
+    'continue_with_pireon' => 'Entrar con Pireon',
     'signing_in' => 'Comprobando tus credenciales…',
     'password_grant_disabled' => 'El acceso con contraseña está desactivado en esta instalación. Avisa a un administrador.',
     'server_unavailable' => 'El servidor de identidad no está respondiendo. No es cosa de tus credenciales; avisa a un administrador.',

routes/web.php

@@ -14,8 +14,9 @@ Route::redirect('/', '/admin');
 | Authentication — Pireon OAuth2 (Authorization Code + PKCE)
 |--------------------------------------------------------------------------
 |
-| `login` is the page Filament bounces guests to; it renders a single button
-| that starts the flow at `auth.redirect`.
+| `login` is the page Filament bounces guests to: an e-mail and password form
+| (password grant) with «Entrar con Pireon» under it, which starts this flow at
+| `auth.redirect`.
 |
 */
 

tests/Feature/Auth/PireonLoginTest.php

@@ -5,8 +5,13 @@ declare(strict_types=1);
 namespace Tests\Feature\Auth;
 
 use App\Models\User;
+use App\Services\Pireon\AccessToken;
+use App\Services\Pireon\TokenStore;
+use Carbon\CarbonImmutable;
 use Database\Seeders\RolePermissionSeeder;
 use Illuminate\Foundation\Testing\RefreshDatabase;
+use Illuminate\Http\Client\Request;
+use Illuminate\Support\Facades\Http;
 use PHPUnit\Framework\Attributes\Test;
 use Tests\FakesPireon;
 use Tests\TestCase;
@@ -144,4 +149,57 @@ class PireonLoginTest extends TestCase
         $this->assertGuest();
         $this->assertNull(session('pireon.token'));
     }
+
+    #[Test]
+    public function the_redirect_flow_uses_its_own_client_when_one_is_set(): void
+    {
+        config(['pireon.redirect_client_id' => 'code-client', 'pireon.redirect_client_secret' => 'code-secret']);
+
+        $response = $this->get(route('auth.redirect'));
+
+        $query = [];
+        parse_str((string) parse_url($response->headers->get('Location'), PHP_URL_QUERY), $query);
+        $this->assertSame('code-client', $query['client_id']);
+
+        $this->fakePireon();
+        $this
+            ->withSession(['pireon.state' => 'expected-state', 'pireon.code_verifier' => 'the-verifier'])
+            ->get(route('auth.callback', ['code' => 'auth-code', 'state' => 'expected-state']))
+            ->assertRedirect();
+
+        // The code is redeemed with the client it was issued for.
+        Http::assertSent(fn (Request $request) => str_ends_with($request->url(), '/oauth/token')
+            && $request['grant_type'] === 'authorization_code'
+            && $request['client_id'] === 'code-client'
+            && $request['client_secret'] === 'code-secret');
+        $this->assertSame('redirect', session('pireon.token_issuer'));
+    }
+
+    #[Test]
+    public function a_redirect_session_renews_its_token_with_the_redirect_client(): void
+    {
+        config(['pireon.redirect_client_id' => 'code-client', 'pireon.redirect_client_secret' => null]);
+        $this->fakePireon(token: ['access_token' => 'renewed-token']);
+
+        $store = app(TokenStore::class);
+        $store->put(new AccessToken('old-token', 'the-refresh-token', CarbonImmutable::now()->subMinute()), viaRedirect: true);
+
+        $this->assertSame('renewed-token', $store->accessToken());
+        Http::assertSent(fn (Request $request) => str_ends_with($request->url(), '/oauth/token')
+            && $request['grant_type'] === 'refresh_token'
+            && $request['client_id'] === 'code-client');
+    }
+
+    #[Test]
+    public function the_login_page_offers_pireon_only_with_a_redirect_client(): void
+    {
+        config(['pireon.redirect_login' => false]);
+        $this->get('/admin/login')->assertOk()->assertDontSee(__('pireon.continue_with_pireon'));
+
+        config(['pireon.redirect_login' => true, 'pireon.redirect_client_id' => 'code-client']);
+        $this->get('/admin/login')
+            ->assertOk()
+            ->assertSee(__('pireon.continue_with_pireon'))
+            ->assertSee(route('auth.redirect'), escape: false);
+    }
 }