$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 $data * @param int port * @return array response */ function _recaptcha_http_post($host, $path, $data, $port = 80) { $req = _recaptcha_qsencode($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 $use_ssl Should the request be made over ssl? (optional, default is false) * @return string - The HTML to be embedded in the user's form. */ function recaptcha_get_html($pubkey, $error = null, $use_ssl = false) { if ($pubkey == null || $pubkey == '') { die("To use reCAPTCHA you must get an API key from http://recaptcha.net/api/getkey"); } if ($use_ssl) { $server = RECAPTCHA_API_SECURE_SERVER; } else { $server = RECAPTCHA_API_SERVER; } $errorpart = ""; if ($error) { $errorpart = "&error=" . $error; } return ' '; } /** * A ReCaptchaResponse is returned from recaptcha_check_answer() */ class ReCaptchaResponse { public $is_valid; public $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 $extra_params an array of extra variables to post to the server * @return ReCaptchaResponse */ function recaptcha_check_answer($privkey, $remoteip, $challenge, $response, $extra_params = array()) { if ($privkey == null || $privkey == '') { die("To use reCAPTCHA you must get an API key from http://recaptcha.net/api/getkey"); } if ($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 ReCaptchaResponse(); $recaptcha_response->is_valid = false; $recaptcha_response->error = 'incorrect-captcha-sol'; return $recaptcha_response; } $response = _recaptcha_http_post( RECAPTCHA_VERIFY_SERVER, "/verify", array( 'privatekey' => $privkey, 'remoteip' => $remoteip, 'challenge' => $challenge, 'response' => $response ) + $extra_params ); $answers = explode("\n", $response [1]); $recaptcha_response = new ReCaptchaResponse(); if (trim($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 $appname The name of your application */ function recaptcha_get_signup_url($domain = null, $appname = null) { return "http://recaptcha.net/api/getkey?" . _recaptcha_qsencode(array('domain' => $domain, 'app' => $appname)); } function _recaptcha_aes_pad($val) { $block_size = 16; $numpad = $block_size - (strlen($val) % $block_size); return str_pad($val, strlen($val) + $numpad, chr($numpad)); } /* Mailhide related code */ 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, $mode, "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"); } function _recaptcha_mailhide_urlbase64($x) { return strtr(base64_encode($x), '+/', '-_'); } /* gets the reCAPTCHA Mailhide url for a given email, public key and private key */ function recaptcha_mailhide_url($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 http://mailhide.recaptcha.net/apikey"); } $ky = pack('H*', $privkey); $cryptmail = _recaptcha_aes_encrypt($email, $ky); return "http://mailhide.recaptcha.net/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 */ function _recaptcha_mailhide_email_parts($email) { $arr = preg_split("/@/", $email); if (strlen($arr[0]) <= 4) { $arr[0] = substr($arr[0], 0, 1); } elseif (strlen($arr[0]) <= 6) { $arr[0] = substr($arr[0], 0, 3); } else { $arr[0] = substr($arr[0], 0, 4); } return $arr; } /** * Gets html to display an email address given a public an private key. * to get a key, go to: * * http://mailhide.recaptcha.net/apikey */ function recaptcha_mailhide_html($pubkey, $privkey, $email) { $emailparts = _recaptcha_mailhide_email_parts($email); $url = recaptcha_mailhide_url($pubkey, $privkey, $email); return htmlentities($emailparts[0]) . "...@" . htmlentities($emailparts [1]); }