configurable recaptcha threshold

Civi/Formprotection/Recaptcha.php

@@ -186,7 +186,7 @@ class Recaptcha {
         // reCAPTCHAv3
         $recaptcha = new \ReCaptcha\ReCaptcha(\Civi::settings()->get('formprotection_recaptcha_privatekey'));
         $resp = $recaptcha
-          ->setScoreThreshold(0.5)
+          ->setScoreThreshold(\Civi::settings()->get('formprotection_recaptcha_threshold'))
           ->verify($token, Utils::getIPAddress());
         if (!$resp->isSuccess()) {
           // If Firewall is enabled, log it there
@@ -378,4 +378,13 @@ class Recaptcha {
     return $addCaptcha;
   }
 
+  public static function validateRecaptchaThreshold(float &$value) : bool {
+    if ($value < 0) {
+      $value = 0;
+    }
+    if ($value > 1) {
+      $value = 1;
+    }
+    return TRUE;
+  }
 }

settings/formprotection.setting.php

@@ -333,6 +333,31 @@ return [
       ],
     ],
   ],
+  'formprotection_recaptcha_threshold' => [
+    'group_name' => 'CiviCRM Preferences',
+    'group' => 'core',
+    'name' => 'formprotection_recaptcha_threshold',
+    'type' => 'float',
+    'quick_form_type' => 'Element',
+    'html_attributes' => [
+      'size' => 10,
+      'maxlength' => 5,
+    ],
+    'html_type' => 'text',
+    'default' => 0.5,
+    'add' => '5.68',
+    'title' => E::ts('reCAPTCHA Threshold'),
+    'is_domain' => 1,
+    'is_contact' => 0,
+    'description' => 'reCAPTCHA scores submissions from 0 (definitely a bot) to 1.0 (definitely a human).  Lower this number if too many humans are being blocked; raise it if too many bots are being allowed.',
+    'validate_callback' => '\Civi\Formprotection\Recaptcha::validateRecaptchaThreshold',
+    'help_text' => NULL,
+    'settings_pages' => [
+      'formprotection' => [
+        'weight' => 215,
+      ],
+    ],
+  ],
   'formprotection_recaptcha_privatekey' => [
     'group_name' => 'CiviCRM Preferences',
     'group' => 'core',