README

reCAPTCHA is a free CAPTCHA service that protects websites from spam and abuse. This is a PHP library that wraps up the server-side verification step required to process responses from the reCAPTCHA service. This client supports both v2 and v3.

• reCAPTCHA: https://www.google.com/recaptcha
• This repo: https://github.com/lptech-asia/lp-recaptcha
• Version: 1.0.0
• License: BSD, see LICENSE

Installation

Composer (recommended)

Use Composer to install this library from Packagist: lptech-asia/lp-recaptcha

Run the following command from your project directory to add the dependency:

composer require lptech-asia/lp-recaptcha "master"

Alternatively, add the dependency directly to your composer.json file:

"require": {
    "lptech-asia/lp-recaptcha": "master"
}

Direct download

Download the ZIP file and extract into your project. An autoloader script is provided in src/autoload.php which you can require into your script. For example:

require_once '/path/to/recaptcha.php';
$recaptcha = new LPRecaptcha('secret-key');

The classes in the project are structured according to the PSR-4 standard, so you can also use your own autoloader or require the needed files directly in your code.

Usage

First obtain the appropriate keys for the type of reCAPTCHA you wish to integrate for v2 at https://www.google.com/recaptcha/admin or v3 at https://g.co/recaptcha/v3.

Then follow the integration guide on the developer site to add the reCAPTCHA functionality into your frontend.

This library comes in when you need to verify the user's response. On the PHP side you need the response from the reCAPTCHA service and secret key from your credentials. Instantiate the LPRecaptcha class with your secret key, specify any additional validation rules, and then call verify() with the reCAPTCHA response (usually in $_POST['g-recaptcha-response'] or the response from grecaptcha.execute() in JS which is in $gRecaptchaResponse in the example) and user's IP address. For example:

<?php
$require '../recaptcha.php';
$recaptcha = new LPRecaptcha('secret-key');
$recaptcha->setSitekey('site-key');
if ($resp->isSuccess()) {
    // Verified!
} else {
    $errors = $resp->getErrorCodes();
}

The following methods are available:

• setExpectedHostname($hostname): ensures the hostname matches. You must do this if you have disabled "Domain/Package Name Validation" for your credentials.
• setExpectedApkPackageName($apkPackageName): if you're verifying a response from an Android app. Again, you must do this if you have disabled "Domain/Package Name Validation" for your credentials.
• setExpectedAction($action): ensures the action matches for the v3 API.
• setScoreThreshold($threshold): set a score threshold for responses from the v3 API
• setChallengeTimeout($timeoutSeconds): set a timeout between the user passing the reCAPTCHA and your server processing it.

Each of the set*() methods return the LPRecaptcha instance so you can chain them together. For example:

<?php
$recaptcha = new LPRecaptcha('secret-key');
$resp = $recaptcha->setExpectedHostname('recaptcha-demo.appspot.com')
                  ->setExpectedAction('homepage')
                  ->setScoreThreshold(0.5)
                  ->verify($gRecaptchaResponse);

if ($resp->isSuccess()) {
    // Verified!
} else {
    $errors = $resp->getErrorCodes();
}