Regenerate CAPTCHA phrase using a custom request with cachebust to avoid caching

[MAILPOET-6038]

mailpoet/assets/js/src/public.tsx

@@ -72,21 +72,37 @@ jQuery(($) => {
   }
 
   async function updateCaptcha(e?: Event) {
+    const captchaSessionId = document.querySelector<HTMLInputElement>(
+      '#mailpoet_captcha_form input[name="data[captcha_session_id]"]',
+    )?.value;
     const image = document.querySelector('img.mailpoet_captcha');
     const audio = document.querySelector<HTMLAudioElement>(
       '.mailpoet_captcha_player',
     );
-    if (!image || !audio) {
+
+    if (!captchaSessionId || !image || !audio) {
       return false;
     }
 
-    // page reload invalidates CAPTCHA, but we can do it with AJAX
-    await fetch(window.location.href);
+    const cachebust = `${new Date().getTime()}`;
+
+    // regenerate captcha phrase
+    const url = new URL(window.location.href.split('?')[0]);
+    url.searchParams.set('mailpoet_router', '');
+    url.searchParams.set('mailpoet_page', 'subscriptions');
+    url.searchParams.set('endpoint', 'subscription');
+    url.searchParams.set('action', 'captchaRefresh');
+    url.searchParams.set(
+      'data',
+      btoa(JSON.stringify({ captcha_session_id: captchaSessionId })),
+    );
+    url.searchParams.set('cachebust', cachebust);
+    await fetch(url);
 
     // image
     if (image) {
       const imageUrl = new URL(image.getAttribute('src'));
-      imageUrl.searchParams.set('cachebust', `${new Date().getTime()}`);
+      imageUrl.searchParams.set('cachebust', cachebust);
       image.setAttribute('src', imageUrl.toString());
     }
 
@@ -94,7 +110,7 @@ jQuery(($) => {
     if (audio) {
       const audioSource = audio.querySelector('source');
       const audioUrl = new URL(audioSource.getAttribute('src'));
-      audioUrl.searchParams.set('cachebust', `${new Date().getTime()}`);
+      audioUrl.searchParams.set('cachebust', cachebust);
       audioSource.setAttribute('src', audioUrl.toString());
       audio.load();
     }

mailpoet/lib/Router/Endpoints/Subscription.php

@@ -13,6 +13,7 @@ class Subscription {
   const ACTION_CAPTCHA = 'captcha';
   const ACTION_CAPTCHA_IMAGE = 'captchaImage';
   const ACTION_CAPTCHA_AUDIO = 'captchaAudio';
+  const ACTION_CAPTCHA_REFRESH = 'captchaRefresh';
   const ACTION_CONFIRM = 'confirm';
   const ACTION_MANAGE = 'manage';
   const ACTION_UNSUBSCRIBE = 'unsubscribe';
@@ -23,6 +24,7 @@ class Subscription {
     self::ACTION_CAPTCHA,
     self::ACTION_CAPTCHA_IMAGE,
     self::ACTION_CAPTCHA_AUDIO,
+    self::ACTION_CAPTCHA_REFRESH,
     self::ACTION_CONFIRM,
     self::ACTION_MANAGE,
     self::ACTION_UNSUBSCRIBE,
@@ -82,6 +84,14 @@ class Subscription {
     exit;
   }
 
+  public function captchaRefresh($data): void {
+    $captchaSessionId = $data['captcha_session_id'] ?? null;
+    if (!$captchaSessionId) {
+      return;
+    }
+    $this->captchaRenderer->refreshPhrase($captchaSessionId);
+  }
+
   public function confirm($data) {
     $subscription = $this->initSubscriptionPage(UserSubscription\Pages::ACTION_CONFIRM, $data);
     $subscription->confirm();

mailpoet/lib/Subscription/Captcha/CaptchaRenderer.php

@@ -75,6 +75,10 @@ class CaptchaRenderer {
     $builder->output();
   }
 
+  public function refreshPhrase(string $sessionId): string {
+    return $this->phrase->createPhrase($sessionId);
+  }
+
   private function getPhrase(string $sessionId): string {
     $phrase = $this->phrase->getPhrase($sessionId);
     if (!$phrase) {

mailpoet/tests/integration/Router/Endpoints/SubscriptionTest.php

@@ -6,6 +6,7 @@ use Codeception\Stub;
 use Codeception\Stub\Expected;
 use MailPoet\Router\Endpoints\Subscription;
 use MailPoet\Subscription\Captcha\CaptchaRenderer;
+use MailPoet\Subscription\Captcha\CaptchaSession;
 use MailPoet\Subscription\Pages;
 use MailPoet\Util\Request;
 use MailPoet\WP\Functions as WPFunctions;
@@ -58,4 +59,13 @@ class SubscriptionTest extends \MailPoetTest {
     $subscription = new Subscription($pages, $this->wp, $this->captchaRenderer, $this->request);
     $subscription->unsubscribe($this->data);
   }
+
+  public function testItRefreshesCaptcha(): void {
+    $captchaSession = $this->diContainer->get(CaptchaSession::class);
+    $captchaSession->setCaptchaHash('123', ['phrase' => 'abc']);
+
+    $subscription = new Subscription($this->make(Pages::class), $this->wp, $this->captchaRenderer, $this->request);
+    $subscription->captchaRefresh(['captcha_session_id' => '123']);
+    $this->assertNotEquals('abc', $captchaSession->getCaptchaHash('123')['phrase']);
+  }
 }

mailpoet/tests/integration/Subscription/Captcha/CaptchaRendererTest.php

@@ -30,4 +30,11 @@ class CaptchaRendererTest extends \MailPoetTest {
       $this->getActualOutputForAssertion()
     );
   }
+
+  public function testItRefreshesPhrase(): void {
+    $sessionId = '123';
+    $this->session->setCaptchaHash($sessionId, ['phrase' => 'abc']);
+    $this->testee->refreshPhrase($sessionId);
+    $this->assertNotEquals('abc', $this->session->getCaptchaHash($sessionId)['phrase']);
+  }
 }