Recaptcha v2 php

.editorconfig

# This file is for unifying the coding style for different editors and IDEs
# editorconfig.org

root = true

[*]
charset = iso-8859
end_of_line = lf
insert_final_newline = true
trim_trailing_whitespace = true
indent_style = space
indent_size = 4

.gitignore

# Add any directories, files, or patterns you don't want to be tracked by version control
.DS_Store
thumbs.db
desktop.ini
node_modules
.env

config.php

<?php

require 'dotenv.php';

/**
 * Google Recaptcha Keys
 */
define('G_RECAPTCHA_SITEKEY', getenv('G_RECAPTCHA_SITEKEY'));
define('G_RECAPTCHA_SECRET', getenv('G_RECAPTCHA_SECRET'));

dotenv.php

<?php

if (file_exists('.env')) {
    $envs = file_get_contents('./.env', FILE_USE_INCLUDE_PATH);
    foreach (array_filter(preg_split('/\r\n|\r|\n/', $envs)) as $line) {
        list($key, $value) = explode('=', $line);
        putenv("$key=$value");
    }
}

index.php

<?php
header('location:recaptcha-v2.php');

phpcs.xml

<?xml version="1.0"?>
<ruleset name="Xframe Coding Standards">

	<arg name="encoding" value="iso-8859" />
	<arg name="tab-width" value="4" />
	<arg value="ps" />

	<!-- Include the whole PSR2 standard -->
	<rule ref="PSR2">
		<exclude phpcs-only="true" name="Generic.ControlStructures.InlineControlStructure" />
		<exclude phpcs-only="true" name="Generic.Functions.FunctionCallArgumentSpacing" />
		<exclude phpcs-only="true" name="Generic.PHP.DisallowShortOpenTag" />
		<exclude name="Generic.NamingConventions.UpperCaseConstantName" />
		<exclude phpcs-only="true" name="Generic.WhiteSpace.DisallowTabIndent" />
		<exclude name="PSR1.Classes.ClassDeclaration" />
		<exclude name="PSR1.Files" />
		<exclude phpcs-only="true" name="PSR2.Files.ClosingTag" />
		<exclude phpcs-only="true" name="Squiz.ControlStructures.ControlSignature" />
	</rule>

	<rule name="Generic.WhiteSpace.DisallowTabIndent" />

	<arg name="extensions" value="php"/>
	<file>.</file>

</ruleset>

recaptcha-v2.php

<?php
require 'config.php';
require 'recaptchalib.php';
?>
<!doctype html>
<html>
<head>
<meta charset="utf-8">
<title>Recaptcha Demo</title>
<script src='https://www.google.com/recaptcha/api.js'></script>
</head>
<body>

<?php
// Checks if form has been submitted
if ('POST' === $_SERVER['REQUEST_METHOD']) {
    // Call the function post_captcha
    $res = recaptcha_check_answer(G_RECAPTCHA_SECRET, $_POST['g-recaptcha-response']);

    if (! $res->is_valid) {
        // What happens when the CAPTCHA wasn't checked
        echo '<p>Please go back and make sure you check the security CAPTCHA box.</p><br>';
    } else {
        // If CAPTCHA is successfully completed...

        // Paste mail function or whatever else you want to happen here!
        echo '<br><p>CAPTCHA was completed successfully!</p><br>';
    }
} else {
?>

    <!-- FORM GOES HERE -->
    <form action="recaptcha-v2.php" method="post">
        <label for="fname">First Name*</label><br>
        <input type="text" name="fname" id="fname" required value="Fist Name" autofocus><br><br>

        <label for="lname">Last Name*</label><br>
        <input type="text" name="lname" id="lname" required value="Last Name"><br><br>

        <label for="email">Email Address*</label><br>
        <input type="email" name="email" id="email" required value="email@domain.com"><br><br>

        <?php echo recaptcha_get_html(G_RECAPTCHA_SITEKEY); ?>
        <br>
        <input type="submit" id="submit" value="Submit">
    </form>

<?php } ?>

</body>
</html>

recaptchalib.php

<?php

class ReCaptcha
{

    const VERSION = 'php_1.1.3';

    private $secret;

    private $requestMethod;

    public function __construct($secret, RequestMethod $requestMethod = null)
    {
        if (empty($secret)) {
            throw new \RuntimeException('No secret provided');
        }

        if (! is_string($secret)) {
            throw new \RuntimeException('The provided secret must be a string');
        }

        $this->secret = $secret;

        if (! is_null($requestMethod)) {
            $this->requestMethod = $requestMethod;
        } else {
            $this->requestMethod = new RequestMethod();
        }
    }

    public function verify($response, $remoteIp = null)
    {
        if (empty($response)) {
            $recaptchaResponse = new Response(false, array( 'missing-input-response' ));
            return $recaptchaResponse;
        }

        $params = new RequestParameters($this->secret, $response, $remoteIp, self::VERSION);

        $rawResponse = $this->requestMethod->submit($params);
        return Response::fromJson($rawResponse);
    }
}

class RequestMethod
{

    const SITE_VERIFY_URL = 'https://www.google.com/recaptcha/api/siteverify';

    public function submit(RequestParameters $params)
    {
        $peer_key = version_compare(PHP_VERSION, '5.6.0', '<') ? 'CN_name' : 'peer_name';
        $options = array(
            'http' => array(
                'header' => "Content-type: application/x-www-form-urlencoded\r\n",
                'method' => 'POST',
                'content' => $params->toQueryString(),
                // Force the peer to validate (not needed in 5.6.0+, but still works)
                'verify_peer' => true,
                // Force the peer validation to use www.google.com
                $peer_key => 'www.google.com',
            ),
        );
        $context = stream_context_create($options);
        return file_get_contents(self::SITE_VERIFY_URL, false, $context);
    }
}

class RequestParameters
{

    private $secret;

    private $response;

    private $remoteIp;

    private $version;

    public function __construct($secret, $response, $remoteIp = null, $version = null)
    {
        $this->secret = $secret;
        $this->response = $response;
        $this->remoteIp = $remoteIp;
        $this->version = $version;
    }

    public function toArray()
    {
        $params = array(
            'secret' => $this->secret,
            'response' => $this->response,
        );

        if (! is_null($this->remoteIp)) {
            $params['remoteip'] = $this->remoteIp;
        }

        if (! is_null($this->version)) {
            $params['version'] = $this->version;
        }

        return $params;
    }

    public function toQueryString()
    {
        return http_build_query($this->toArray(), '', '&');
    }
}

class Response
{

    private $success = false;

    private $errorCodes = array();

    private $hostname;

    public static function fromJson($json)
    {
        $responseData = json_decode($json, true);

        if (! $responseData) {
            return new Response(false, array( 'invalid-json' ));
        }

        $hostname = isset($responseData['hostname']) ? $responseData['hostname'] : null;

        if (isset($responseData['success']) && $responseData['success'] == true) {
            return new Response(true, array(), $hostname);
        }

        if (isset($responseData['error-codes']) && is_array($responseData['error-codes'])) {
            return new Response(false, $responseData['error-codes'], $hostname);
        }

        return new Response(false, array(), $hostname);
    }

    public function __construct($success, array $errorCodes = array(), $hostname = null)
    {
        $this->success = $success;
        $this->errorCodes = $errorCodes;
        $this->hostname = $hostname;
    }

    public function isSuccess()
    {
        return $this->success;
    }

    public function getErrorCodes()
    {
        return $this->errorCodes;
    }

    public function getHostname()
    {
        return $this->hostname;
    }
}

function recaptcha_get_html($sitekey, $error = null, $use_ssl = false)
{
    if ($sitekey == null || $sitekey == '') {
        die('To use reCAPTCHA you must get an API key from <a href="https://www.google.com/recaptcha/admin/create">https://www.google.com/recaptcha/admin/create</a>');
    }

    return '<div class="g-recaptcha" data-sitekey="' . $sitekey . '"></div>';
}

class ReCaptchaResponse
{
    var $is_valid;
    var $error;
}

function recaptcha_check_answer($secret, $response, $remoteip = '', $extra_params = array())
{
    $recaptcha = new Recaptcha($secret);
    $response = $recaptcha->verify($response, $remoteip);
    $recaptcha_response = new ReCaptchaResponse();
    if ($response->isSuccess()) {
        $recaptcha_response->is_valid = true;
    } else {
        $recaptcha_response->is_valid = false;
        $recaptcha_response->error = $response->getErrorCodes();
    }
    return $recaptcha_response;
}