Implement ReCaptcha protection for registration

Author: themightychris

html-templates/register/register.tpl

@@ -2,6 +2,14 @@
 
 {block "title"}Register — {$dwoo.parent}{/block}
 
+{block js-top}
+    {$dwoo.parent}
+
+    {if RemoteSystems\ReCaptcha::$siteKey}
+        <script src='https://www.google.com/recaptcha/api.js'></script>
+    {/if}
+{/block}
+
 {block "content"}
     {$User = $data}
     <form method="POST" id="register">
@@ -49,7 +57,11 @@
                 <label for="PasswordConfirm">{_ "Password Confirmation"}</label>
                 <input type="password" class="form-control" id="PasswordConfirm" name="PasswordConfirm" value="{refill field=PasswordConfirm}">
             </div>
-            
+
+            {if RemoteSystems\ReCaptcha::$siteKey}
+                <div class="form-group g-recaptcha" data-sitekey="{RemoteSystems\ReCaptcha::$siteKey|escape}"></div>
+            {/if}
+
             <div class="form-group">
                 <button type="submit" class="btn btn-primary">{_ "Create Account"}</button>
                 <p class="help-block">{_ "Already have an account?"} <a href="/login{tif $.request.return ? cat('?return=', escape($.request.return, url))}">{_ "Log in"}</a></p>

php-classes/RemoteSystems/ReCaptcha.php

@@ -0,0 +1,25 @@
+<?php
+
+namespace RemoteSystems;
+
+class ReCaptcha
+{
+    public static $siteKey;
+    public static $secretKey;
+
+    protected static $instance;
+
+    public static function setInstance(\ReCaptcha\ReCaptcha $instance)
+    {
+        static::$instance = $instance;
+    }
+
+    public static function getInstance()
+    {
+        if (!static::$instance && static::$secretKey) {
+            static::$instance = new \ReCaptcha\ReCaptcha(static::$secretKey);
+        }
+
+        return static::$instance;
+    }
+}

php-config/Emergence/People/RegistrationRequestHandler.config.php

@@ -19,4 +19,14 @@
 #        'replace_interests' => false,
 #        'send_welcome' => false
 #    ]);
-#};
+#};
+
+RegistrationRequestHandler::$applyRegistrationData = function(User $User, array $requestData, array &$additionalErrors) {
+    if ($recaptcha = \RemoteSystems\ReCaptcha::getInstance()) {
+        $recaptchaResponse = $recaptcha->verify($requestData['g-recaptcha-response'], $_SERVER['REMOTE_ADDR']);
+
+        if (!$recaptchaResponse->isSuccess()) {
+            $additionalErrors['ReCaptcha'] = 'Please prove that you aren\'t a spam robot by completing the reCAPTCHA';
+        }
+    }
+};

php-config/RemoteSystems/ReCaptcha.config.php

@@ -0,0 +1,9 @@
+<?php
+
+/**
+ * Obtain site and secret keys from Google by registering
+ * at https://www.google.com/recaptcha/admin
+ */
+
+//RemoteSystems\ReCaptcha::$siteKey = 'YOUR_SITE_KEY';
+//RemoteSystems\ReCaptcha::$secretKey = 'YOUR_SECRET_KEY';