Replace captcha package with own implementation

app/Http/Controllers/Auth/CaptchaController.php

@@ -0,0 +1,30 @@
+<?php
+
+namespace App\Http\Controllers\Auth;
+
+use AltchaOrg\Altcha\Algorithm\Pbkdf2;
+use AltchaOrg\Altcha\Altcha;
+use AltchaOrg\Altcha\CreateChallengeOptions;
+use App\Http\Controllers\Controller;
+
+class CaptchaController extends Controller
+{
+    public function create(): array
+    {
+        $pbkdf2 = new Pbkdf2;
+
+        $altcha = new Altcha(
+            hmacSignatureSecret: config('captcha.hmac_key'),
+        );
+
+        // Create challenge
+        $challenge = $altcha->createChallenge(new CreateChallengeOptions(
+            algorithm: $pbkdf2,
+            cost: 5000,
+            counter: random_int(5000, 10000),
+            expiresAt: time() + 600,
+        ));
+
+        return get_object_vars($challenge);
+    }
+}

app/Http/Controllers/Auth/RegisteredUserController.php

@@ -4,7 +4,7 @@ namespace App\Http\Controllers\Auth;
 
 use App\Http\Controllers\Controller;
 use App\Models\User;
-use GrantHolle\Altcha\Rules\ValidAltcha;
+use App\Rules\ValidCaptcha;
 use Illuminate\Auth\Events\Registered;
 use Illuminate\Http\RedirectResponse;
 use Illuminate\Http\Request;
@@ -25,7 +25,7 @@ class RegisteredUserController extends Controller
             'name' => ['required', 'string', 'max:255'],
             'email' => ['required', 'string', 'lowercase', 'email', 'max:255', 'unique:'.User::class],
             'password' => ['required', 'confirmed', Rules\Password::defaults()],
-            'altcha' => ['required', new ValidAltcha],
+            'altcha' => ['required', new ValidCaptcha],
         ]);
 
         $user = User::create([