recaptchalib.php in Google Captcha 7

File

ReCAPTCHA/php/recaptchalib.php

<?php

/**
 * This is a PHP library that handles calling reCAPTCHA.
 *    - Documentation and latest version
 *          https://developers.google.com/recaptcha/docs/php
 *    - Get a reCAPTCHA API Key
 *          https://www.google.com/recaptcha/admin/create
 *    - Discussion group
 *          http://groups.google.com/group/recaptcha
 *
 * @copyright Copyright (c) 2014, Google Inc.
 * @link      http://www.google.com/recaptcha
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */

/**
 * A ReCaptchaResponse is returned from checkAnswer().
 */
class ReCaptchaResponse {
  public $success;
  public $errorCodes;

}
class ReCaptcha {
  private static $_signupUrl = "https://www.google.com/recaptcha/admin";
  private static $_siteVerifyUrl = "https://www.google.com/recaptcha/api/siteverify?";
  private $_secret;
  private static $_version = "php_1.0";

  /**
   * Constructor.
   *
   * @param string $secret shared secret between site and ReCAPTCHA server.
   */
  function ReCaptcha($secret) {
    if ($secret == null || $secret == "") {
      die("To use reCAPTCHA you must get an API key from <a href='" . self::$_signupUrl . "'>" . self::$_signupUrl . "</a>");
    }
    $this->_secret = $secret;
  }

  /**
   * Encodes the given data into a query string format.
   *
   * @param array $data array of string elements to be encoded.
   *
   * @return string - encoded request.
   */
  private function _encodeQS($data) {
    $req = "";
    foreach ($data as $key => $value) {
      $req .= $key . '=' . urlencode(stripslashes($value)) . '&';
    }

    // Cut the last '&'
    $req = substr($req, 0, strlen($req) - 1);
    return $req;
  }

  /**
   * Submits an HTTP GET to a reCAPTCHA server.
   *
   * @param string $path url path to recaptcha server.
   * @param array  $data array of parameters to be sent.
   *
   * @return array response
   */
  private function _submitHTTPGet($path, $data) {
    $req = $this
      ->_encodeQS($data);
    $response = file_get_contents($path . $req);
    return $response;
  }

  /**
   * Calls the reCAPTCHA siteverify API to verify whether the user passes
   * CAPTCHA test.
   *
   * @param string $remoteIp   IP address of end user.
   * @param string $response   response string from recaptcha verification.
   *
   * @return ReCaptchaResponse
   */
  public function verifyResponse($remoteIp, $response) {

    // Discard empty solution submissions
    if ($response == null || strlen($response) == 0) {
      $recaptchaResponse = new ReCaptchaResponse();
      $recaptchaResponse->success = false;
      $recaptchaResponse->errorCodes = 'missing-input';
      return $recaptchaResponse;
    }
    $getResponse = $this
      ->_submitHttpGet(self::$_siteVerifyUrl, array(
      'secret' => $this->_secret,
      'remoteip' => $remoteIp,
      'v' => self::$_version,
      'response' => $response,
    ));
    $answers = json_decode($getResponse, true);
    $recaptchaResponse = new ReCaptchaResponse();
    if (trim($answers['success']) == true) {
      $recaptchaResponse->success = true;
    }
    else {
      $recaptchaResponse->success = false;
      $recaptchaResponse->errorCodes = $answers[error - codes];
    }
    return $recaptchaResponse;
  }

}

Classes

Name	Description
ReCaptcha
ReCaptchaResponse	A ReCaptchaResponse is returned from checkAnswer().