$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 {
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 $extra_params an array of extra variables to post to the server
* @return ReCaptchaResponse
*/
function recaptcha_check_answer($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);
} else
if (strlen($arr[0]) <= 6) {
$arr[0] = substr($arr[0], 0, 3);
} else {
$arr[0] = substr($arr[0], 0, 4);
}
return $arr;
}
/**
* Gets html to display an email address given a public an private key.
* to get a key, go to:
*
* http://mailhide.recaptcha.net/apikey
*/
function recaptcha_mailhide_html($pubkey, $privkey, $email) {
$emailparts = _recaptcha_mailhide_email_parts($email);
$url = recaptcha_mailhide_url($pubkey, $privkey, $email);
return htmlentities($emailparts[0]) . "...@" . htmlentities($emailparts[1]);
}
?>