recaptchalib.php 11 KB
<?php

///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

namespace
{
    ///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

    class recaptchalib extends \core
    {


        /**
         * The reCAPTCHA server URL's
         */
        private $recaptcha_api_server           = 'http://www.google.com/recaptcha/api';
        private $recaptcha_api_secure_server    = 'https://www.google.com/recaptcha/api';
        private $recaptcha_verify_server        = 'www.google.com';

        private $publickey                      = "6LcUoOsSAAAAAJs-DBzJwt9dRnPZDZBHHjW2Sgiv";
        private $privatekey                     = "6LcUoOsSAAAAAMp1rRWCOpbe4-00VKmNrDGLdydi";

        //define("RECAPTCHA_API_SERVER", "http://www.google.com/recaptcha/api");
        //define("RECAPTCHA_API_SECURE_SERVER", "https://www.google.com/recaptcha/api");
        //define("RECAPTCHA_VERIFY_SERVER", "www.google.com");

        /**
         * Encodes the given data into a query string format
         * @param $data - array of string elements to be encoded
         * @return string - encoded request
         */
        protected function _recaptcha_qsencode ($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 POST to a reCAPTCHA server
         * @param string $host
         * @param string $path
         * @param array $data
         * @param int port
         * @return array response
         */
        protected function _recaptcha_http_post($host, $path, $data, $port = 80) {

                $req = $this->_recaptcha_qsencode ($data);

                $http_request  = "POST $path HTTP/1.0\r\n";
                $http_request .= "Host: $host\r\n";
                $http_request .= "Content-Type: application/x-www-form-urlencoded;\r\n";
                $http_request .= "Content-Length: " . strlen($req) . "\r\n";
                $http_request .= "User-Agent: reCAPTCHA/PHP\r\n";
                $http_request .= "\r\n";
                $http_request .= $req;

                $response = '';
                if( false == ( $fs = @fsockopen($host, $port, $errno, $errstr, 10) ) ) {
                        die ('Could not open socket');
                }

                fwrite($fs, $http_request);

                while ( !feof($fs) )
                        $response .= fgets($fs, 1160); // One TCP-IP packet
                fclose($fs);
                $response = explode("\r\n\r\n", $response, 2);

                return $response;
        }



        /**
         * Gets the challenge HTML (javascript and non-javascript version).
         * This is called from the browser, and the resulting reCAPTCHA HTML widget
         * is embedded within the HTML form it was called from.
         * @param string $pubkey A public key for reCAPTCHA
         * @param string $error The error given by reCAPTCHA (optional, default is null)
         * @param boolean $use_ssl Should the request be made over ssl? (optional, default is false)

         * @return string - The HTML to be embedded in the user's form.
         */
        public function recaptcha_get_html ( $error = null, $use_ssl = false)
        {
            $pubkey = $this->publickey;

            if ($pubkey == null || $pubkey == '') {
                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>");
            }

            if ($use_ssl) {
                        $server = $this->recaptcha_api_secure_server;
                } else {
                        $server = $this->recaptcha_api_server;
                }

                $errorpart = "";
                if ($error) {
                   $errorpart = "&amp;error=" . $error;
                }
                return '<script type="text/javascript" src="'. $server . '/challenge?k=' . $pubkey . $errorpart . '"></script>

            <noscript>
                <iframe src="'. $server . '/noscript?k=' . $pubkey . $errorpart . '" height="300" width="500" frameborder="0"></iframe><br/>
                <textarea name="recaptcha_challenge_field" rows="3" cols="40"></textarea>
                <input type="hidden" name="recaptcha_response_field" value="manual_challenge"/>
            </noscript>';
        }




        /**
         * A ReCaptchaResponse is returned from recaptcha_check_answer()
         */
        /*class ReCaptchaResponse {
                var $is_valid;
                var $error;
        }*/


        /**
          * Calls an HTTP POST function to verify if the user's guess was correct
          * @param string $privkey
          * @param string $remoteip
          * @param string $challenge
          * @param string $response
          * @param array $extra_params an array of extra variables to post to the server
          * @return ReCaptchaResponse
          */
        public function recaptcha_check_answer ($remoteip, $challenge, $response, $extra_params = array())
        {
            $privkey = $this->privatekey;
            if ($privkey == null || $privkey == '') {
                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>");
            }

            if ($remoteip == null || $remoteip == '') {
                die ("For security reasons, you must pass the remote ip to reCAPTCHA");
            }



                //discard spam submissions
                if ($challenge == null || strlen($challenge) == 0 || $response == null || strlen($response) == 0) {
                        $recaptcha_response = new \stdClass();
                        $recaptcha_response->is_valid = false;
                        $recaptcha_response->error = 'incorrect-captcha-sol';
                        return $recaptcha_response;
                }

                $response = $this->_recaptcha_http_post ($this->recaptcha_verify_server, "/recaptcha/api/verify",
                                                  array (
                                                         'privatekey' => $privkey,
                                                         'remoteip' => $remoteip,
                                                         'challenge' => $challenge,
                                                         'response' => $response
                                                         ) + $extra_params
                                                  );

                $answers = explode ("\n", $response [1]);
                $recaptcha_response = new \stdClass();

                if (trim ($answers [0]) == 'true') {
                        $recaptcha_response->is_valid = true;
                }
                else {
                        $recaptcha_response->is_valid = false;
                        $recaptcha_response->error = $answers [1];
                }
                return $recaptcha_response;

        }

        /**
         * gets a URL where the user can sign up for reCAPTCHA. If your application
         * has a configuration page where you enter a key, you should provide a link
         * using this function.
         * @param string $domain The domain where the page is hosted
         * @param string $appname The name of your application
         */
        public function recaptcha_get_signup_url ($domain = null, $appname = null) {
            return "https://www.google.com/recaptcha/admin/create?" .  $this->_recaptcha_qsencode (array ('domains' => $domain, 'app' => $appname));
        }

        protected function _recaptcha_aes_pad($val) {
            $block_size = 16;
            $numpad = $block_size - (strlen ($val) % $block_size);
            return str_pad($val, strlen ($val) + $numpad, chr($numpad));
        }

        /* Mailhide related code */

        protected function _recaptcha_aes_encrypt($val,$ky) {
            if (! function_exists ("mcrypt_encrypt")) {
                die ("To use reCAPTCHA Mailhide, you need to have the mcrypt php module installed.");
            }
            $mode=MCRYPT_MODE_CBC;
            $enc=MCRYPT_RIJNDAEL_128;
            $val=_recaptcha_aes_pad($val);
            return mcrypt_encrypt($enc, $ky, $val, $mode, "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0");
        }


        protected function _recaptcha_mailhide_urlbase64 ($x) {
            return strtr(base64_encode ($x), '+/', '-_');
        }

        /* gets the reCAPTCHA Mailhide url for a given email, public key and private key */
        public function recaptcha_mailhide_url($pubkey, $privkey, $email) {
            if ($pubkey == '' || $pubkey == null || $privkey == "" || $privkey == null) {
                die ("To use reCAPTCHA Mailhide, you have to sign up for a public and private key, " .
                     "you can do so at <a href='http://www.google.com/recaptcha/mailhide/apikey'>http://www.google.com/recaptcha/mailhide/apikey</a>");
            }


            $ky = pack('H*', $privkey);
            $cryptmail = _recaptcha_aes_encrypt ($email, $ky);

            return "http://www.google.com/recaptcha/mailhide/d?k=" . $pubkey . "&c=" . _recaptcha_mailhide_urlbase64 ($cryptmail);
        }

        /**
         * gets the parts of the email to expose to the user.
         * eg, given johndoe@example,com return ["john", "example.com"].
         * the email is then displayed as john...@example.com
         */
        protected function _recaptcha_mailhide_email_parts ($email) {
            $arr = preg_split("/@/", $email );

            if (strlen ($arr[0]) <= 4) {
                $arr[0] = substr ($arr[0], 0, 1);
            } else if (strlen ($arr[0]) <= 6) {
                $arr[0] = substr ($arr[0], 0, 3);
            } else {
                $arr[0] = substr ($arr[0], 0, 4);
            }
            return $arr;
        }

        /**
         * Gets html to display an email address given a public an private key.
         * to get a key, go to:
         *
         * http://www.google.com/recaptcha/mailhide/apikey
         */
        public function recaptcha_mailhide_html($pubkey, $privkey, $email) {
            $emailparts = _recaptcha_mailhide_email_parts ($email);
            $url = recaptcha_mailhide_url ($pubkey, $privkey, $email);

            return htmlentities($emailparts[0]) . "<a href='" . htmlentities ($url) .
                "' onclick=\"window.open('" . htmlentities ($url) . "', '', 'toolbar=0,scrollbars=0,location=0,statusbar=0,menubar=0,resizable=0,width=500,height=300'); return false;\" title=\"Reveal this e-mail address\">...</a>@" . htmlentities ($emailparts [1]);

        }
    }

}

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